HomeMy WebLinkAboutWastewater Management Plan (2013 Final Report)MAY 2013
04094007.0000
Wastewater Management Plan
FINAL REPORT
Imagine the result
Wastewater Management Plan
May, 2013
May 2013 i
Table of Contents
EXECUTIVE SUMMARY 1
Background and Purpose 1
Summary of Conclusions 2
Wastewater Flow Projections 2
Wastewater Collection System 2
Recycled Water Supply and Demand 3
Future Wastewater and Recycled Water Management Options 4
Wastewater Collection System Recommendations 5
Hydraulic Model 5
Recommended Wastewater System Improvements 5
Recommended Wastewater Management and Recycled Water
Strategies 8
1.0 INTRODUCTION 9
1.1 Background 9
1.2 Project Purpose and Scope 10
2.0 WASTEWATER FLOW PROJECTIONS 11
2.1 Study Area 11
2.2 Previous Wastewater Flow Projections 13
2.3 Population Projections 13
2.4 Calibration of Unit Wastewater Flow Factors 14
2.5 Wastewater Flow Projections 16
3.0 WASTEWATER COLLECTION SYSTEM ANALYSIS 18
3.1 Existing Wastewater Collection System 18
3.1.1 Ralph W. Chapman Water Reclamation Facility 18
3.1.2 Pump Stations 20
3.1.3 Collection System Pipes 21
3.2 Wastewater System Hydraulic Model 22
May 2013 ii
Table of Contents
3.2.1 Model Software and Modeled System 22
3.2.2 Model Calibration 23
3.2.3 Assessment of Existing Hydraulic Model 25
3.2.4 Model Use in the Wastewater Management Plan 26
3.2.5 Hydraulic Model Updates 26
3.3 Analysis of Existing System 27
3.3.1 Evaluation Criteria 28
3.3.2 Existing System Assessment 29
3.3.3 Existing System Improvements 31
3.4 Analysis of Future Conditions 31
3.4.1 Future System Assessment 33
3.4.2 Future System Improvements 33
3.5 Summary of Recommended System Improvements & Conceptual
Cost Opinions 36
4.0 RECYCLED WATER SUPPLY ANALYSIS 38
4.1 Recycled Water Distribution Facilities 38
4.2 Existing Recycled Water Supplies 38
4.2.1 Recycled Water from the RWCWRF 39
4.2.2 Recycled Water from the SBWRP 39
4.3 Existing and Projected Recycled Water Usage 40
4.4 Comparison of Recycled Water Demands and Existing Supplies 41
4.5 Potential Additional Recycled Water Supply Options 43
4.5.1 Expansion of the RWCWRF 44
4.5.2 Additional Purchases from the SBWRP 45
4.5.3 Partnership with City Of Chula Vista 45
4.5.4 Joint WRF with San Diego County 47
5.0 ANALYSIS OF WASTEWATER MANAGEMENT OPTIONS 48
May 2013 iii
Table of Contents
5.1 Identification of Wastewater Management Options 48
5.1.1 Option A: Maintain RWCWRF at 1.3 MGD 49
5.1.2 Option B: Expand RWCWRF to 2.6 MGD 50
5.1.3 Option C: Expand RWCWRF to 3.9 MGD 51
5.1.4 Option D: Abandon RWCWRF and Utilize Metro 53
5.1.5 Option E: Abandon RWCWRF and Utilize New Joint District/County WRF 53
5.2 Summary of Cost Components for Wastewater Management Options 55
5.3 Cost Estimates for Expansion and Demolition of the RWCWRF 57
5.3.1 Estimated Construction Costs for RWCWRF Options 57
5.3.2 Estimated Additional O&M Costs for RWCWRF Options 57
5.3.3 Estimated Decommissioning Costs for RWCWRF Options 59
5.4 Summary of Wastewater Management Options Cost Evaluations 59
5.4.1 Common Economic Cost Assumptions 59
5.4.2 Summary of Cost Comparisons for Wastewater Management Options 60
6.0 CONCLUSIONS AND RECOMMENDATIONS 62
6.1 Summary of Conclusions 62
6.2 Wastewater Collection System Recommendations 65
6.2.1 Hydraulic Model 65
6.2.2 Recommended Wastewater System Improvements 65
6.3 Recommended Wastewater Management and Recycled Water Strategies 68
6.4 Potential Funding Sources for Wastewater Capital Improvements 69
6.4.1 Internal Funding Options 69
6.4.2 External Funding Options 69
7.0 LIST OF REFERENCES 72
May 2013 iv
Table of Contents
Tables
Table ES-1. Recommended Wastewater Collection System Improvements 5
Table 2-1. Existing and Projected Populations within the Jamacha Basin1 14
Table 2-2. Calibration Summary of Unit Wastewater Generation Factors 16
Table 2-3. Updated Wastewater Flow Projections for the Jamacha Basin 17
Table 2-4. Updated Wastewater Flow Projections for District Service Area 17
Table 3-1. Summary of Wastewater Pump Stations 20
Table 3-2. Summary of Collection System Pipes 22
Table 3-3: Peaking Factors 23
Table 3-4. Hydraulic Model Invert Elevation Updates 26
Table 3-5. Hydraulic Model Pipe Size Updates 27
Table 3-6. CIP Projects Added to the Hydraulic Model 27
Table 3-7. Wastewater System Performance Criteria 28
Table 3-8. Existing System Deficiencies 29
Table 3-9. Recommended Existing System Improvements 31
Table 3-10. Future System Deficiencies 33
Table 3-11. Recommended System Improvements for 2030 Flow Conditions 36
Table 3-12. Summary of Recommended System Improvements 37
Table 4-1. Projected Recycled Water Demands1 41
Table 4-2. Projected Monthly Recycled Water Demands 42
Table 4-3. Projected Peak Day Recycled Water Demands vs. Existing Supply 43
Table 5-1. Wastewater Treatment Cost Components 55
Table 5-2. Recycled Water Sources for Wastewater Management Options 56
Table 5-4. Opinions of Construction Costs for RWCWRF Options 58
Table 5-5. Opinions of Additional O&M Costs for RWCWRF Options 58
Table 5-6. Common Economic Cost Assumptions 60
May 2013 v
Table of Contents
Table 5-7. Present Worth Cost Summary for Wastewater Management Options 61
Table 6-1. Recommended Wastewater Collection System Improvements 65
Figures
Figure ES-2 Future System Improvements 7
Figure 2-1 Study Area 12
Figure 2-2 Wastewater Generation Parcels 15
Figure 3-1 Existing Collection System 19
Figure 3-2 Flow Meter Basins 24
Figure 3-3 Existing System Assessment 30
Figure 3-4 Existing System Improvements 32
Figure 3-5 Future System Assessment 34
Figure 3-6 Future System Improvements 35
Figure 5.1 Option A: Maintain RWCWRF at 1.3 MGD 50
Figure 5.2 Option B: Expand RWCWRF to 2.6 MGD 51
Figure 5.3 Option C: Expand RWCWRF to 3.9 MGD 52
Figure 5.4 Option D: Abandon RWCWRF and Utilize Metro 53
Figure 5.5 Option E: Abandon RWCWRF and Utilize New Joint District/County WRF55
Figure 6-1 Alignment for CIP #3 67
Figure 6-1. Alignment for CIP #3 67
May 2013 vi
Table of Contents
Appendices
Appendix A - Technical Memorandum: Recycled Water Supply Augmentation
Planning Level Study
Appendix B - RWCWRF Expansion Options Site Layout
Appendix C - Technical Memorandum: Summary of Costs Associated with Upgrade, Expansion and Decommissioning of the Ralph W. Chapman Water
Reclamation Facility
Appendix D - Analysis of Wastewater Management Options
Appendix E - Cost Evaluations Excel Workbook
May 2013 vii
Table of Contents
Abbreviations and Acronyms
AACE Association for the of Advancement of Cost Engineering
International
AF acre-foot
AFY acre-foot per year
Bureau U.S. Bureau of Reclamation
CIP Capital improvement program
County County of San Diego
District Otay Water District
ENR CCI Engineering News Record Construction Cost Index
EPA Environmental Protection Agency
FY Fiscal Year
gpcd gallons per capita per day
gpm gallons per minute
IBWC International Boundary and Water Commission
IPR Indirect potable reuse
KWH Kilowatt-hour
MBR Membrane bioreactor
Metro System City of San Diego Metropolitan Wastewater System
MGD million gallons per day
MGRA Master geographic reference area
MWD Metropolitan Water District of Southern California
NPDES National Pollution Discharge Elimination System
O&M operations and maintenance
PEIR Program Environmental Impact Report
PLWWTP Point Loma Wastewater Treatment Plant
PVC Polyvinyl chloride
RCW Recycled water
RDII Rainfall derived infiltration and inflow
RSDPS Rancho San Diego Pump Station
RSDOF Rancho San Diego Outfall Facilities
RWCWRF Ralph W. Chapman Water Recycling Facility
SANDAG San Diego Association of Governments
SBPS Steel Bridge Pump Station
SBWRP City of San Diego South Bay Water Reclamation Plant
SDCWA San Diego County Water Authority
SPEIR Supplemental Program Environmental Impact Report
SSMP Sewer System Management Plan
SVO Spring Valley Outfall
May 2013 viii
Table of Contents
Title 22 Title 22, Division 4, Chapter 3 of the California Code of
Regulations
USBR United States Bureau of Reclamation
WAS Water Agencies’ Standards
WRF Water Reclamation Facility
WWTP Wastewater Treatment Plant
May 2013 1
Wastewater
Management
Plan
EXECUTIVE SUMMARY
Background and Purpose
The Otay Water District (District), located in the southern portion of San Diego County,
provides wastewater service to a portion of the land area within the Jamacha Basin,
which is located within its North District. The County of San Diego also provides
wastewater service in a portion of the Jamacha Basin. Wastewater flows from each
agency’s customers are conveyed in joint collection and pumping systems.
Wastewater generated in the Jamacha Basin can be discharged into the City of San
Diego Metropolitan Wastewater System (Metro System). The District owns and
operates the Ralph W. Chapman Water Reclamation Facility (RWCWRF) within the
Jamacha Basin, which is operated as a skimming facility. Wastewater flows generated
within the Jamacha Basin are pumped to the RWCWRF and treated to produce
recycled water, which is used to meet a portion of the District’s existing recycled water
demand. All remaining wastewater flows are discharged into the Metro System via the
County’s Rancho San Diego Outfall Facilities (RSDOF) and the downstream Spring
Valley Outfall (SVO). The 2010 wastewater collection rates within the Jamacha Basin
for connected sewer customers only were about 1.3 MGD for the District and about
0.65 MGD for the County. Wastewater collection, pumping, and treatment costs are
shared between the District and the County as provided in the 1998 agreement
between the Spring Valley Sanitation District (now San Diego County) and the Otay
Water District.
There are currently two sources of recycled water supply to the District. The
RWCWRF can treat up to 1.3 MGD. The District also entered into an agreement with
the City of San Diego that allows the District to purchase up to 6.0 MGD of recycled
water generated by the City’s South Bay Water Reclamation Plant (SBWRP).
Previous planning studies have evaluated various wastewater treatment and disposal
options available to the District and the County. These studies have indicated that
local treatment and marketing of recycled water are economical and preferable under
certain conditions, and Metro System wastewater disposal is superior under other
conditions. The primary factors affecting the comparison of the options available are
total wastewater collected for disposal, total costs of local and Metro System service,
revenues from the sale of recycled water, and risk exposure to future costs in the Metro
System.
May 2013 2
Wastewater
Management
Plan
The purpose of this project is to prepare a comprehensive Wastewater Management
Plan that considers required improvements to the District’s wastewater collection
system and identifies a preferred strategy for future wastewater management and
recycled water generation and purchase. The scope of services for the project
generally includes the following:
• Update of the wastewater flow projections for the Jamacha Basin.
• Identification of wastewater collection system improvements and costs that
will accommodate projected wastewater flows.
• Determination of additional recycled water supplies needed through 2030.
• Review of potential sources and costs of additional recycled water supplies.
• Identification and analysis of local and regional options available to the
District for future wastewater management and recycled water supply to
identify a preferred strategy.
• Development of recommended wastewater system improvements and costs
for consideration in the District’s wastewater capital improvement program.
Summary of Conclusions
The work conducted in this Wastewater Management Plan yields the following
conclusions:
Wastewater Flow Projections
• The total Jamacha Basin wastewater generation, including connected and
unconnected properties are projected to increase from 2.48 MGD in 2010 to
2.96 MGD in 2030.
• Wastewater generation in the District’s service area within the Jamacha
Basin, from connected and unconnected properties, is projected to increase
from 1.84 MGD in 2010 to 2.15 MGD in 2030
• Wastewater generation in the County’s service area within the Jamacha
Basin, including connected and unconnected properties, is projected to
increase from 0.64 MGD in 2010 to 0.81 MGD in 2030.
Wastewater Collection System
• The existing collection system has three problem areas that do not meet
system performance criteria under peak flow conditions. These problem
areas can be corrected by replacing the existing undersized sewer pipes.
• One of the existing problem areas is along Campo Road in a section of 10-
inch pipe that has been converted from a forcemain to a gravity pipe, and is
May 2013 3
Wastewater
Management
Plan
undersized to act adequately as a gravity pipe. The District wants the entire
length of this pipe replaced with a 15-inch gravity pipe.
• The existing collection system has two additional areas that do not meet
system performance criteria under 2030 peak flow conditions. The
undersized sewer pipes in these areas should also be replaced as funds
become available.
Recycled Water Supply and Demand
• The District’s existing recycled water supply consists of an average of 1.0
MGD from the RWCWRF and up to 6 MGD annually from the SBWRP. Due
to problems with wastewater supply to SBWRP, other large demands taking
priority, etc., the actual peak availability of recycled water from the SBWRP
has recently been only 5.3 MGD. These problems are anticipated to be
corrected by 2015.
• The District projects that its recycled water volumetric demand will increase
from 4,074 AFY in 2010 to 8,000 AFY in 2035.
• The District will begin seeing deficits in monthly recycled water supply by
2020 during the peak demand months. The deficits during the two peak
demand months are projected to grow from approximately 670 AF in 2020 to
1,100 AF in 2035. The deficits are also expected to occur for over half the
year. These deficits are not annual and can be mitigated if the
District/SBWRP agreement can be amended to allow the District to take its
contracted amount at up to two times its annual average rate during peak
demand months.
• The District is already seeing supply deficits in meeting peak day recycled
water demands and has had to occasionally supplement with potable water.
The peak day supply deficit is projected to grow from approximately 1.0
MGD in 2010 to 7.3 MGD in 2035. The deficits can be managed with
appropriate recycled water system storage and a modification to the
District/SBWRP agreement, as described above.
• Potential additional supplies of recycled water include the following sources:
o Expansion of the RWCWRF
o Additional purchases from the City of San Diego SBWRP
o Purchase of recycled water from a potential new City of Chula Vista
regional WRF
o A potential new joint WRF with San Diego County
o A new joint WRF with the International Boundary and Water
Commission at the South Bay International Wastewater Treatment
Plant.
May 2013 4
Wastewater
Management
Plan
Future Wastewater and Recycled Water Management Options
• Future wastewater treatment options include the RWCWRF, discharge to the
Metro System, and potential partnership with the County in a new 10 MGD
water reclamation plant.
• Five overall future wastewater management and recycled water options were
selected for economic evaluations:
o Option A – maintain RWCWRF at 1.3 MGD
o Option B – expand RWCWRF to 2.6 MGD
o Option C – expand RWCWRF to 3.9 MGD
o Option D – decommission RWCWRF and send all flow to Metro
o Option E – decommission RWCWRF and build joint plant with County
• The evaluation of RWCWRF options considered onsite solids handling and
no onsite solids handling. The joint District/County plant options considered
only onsite solids handling consistent will all previous planning efforts. All
options involving discharge of flows to Metro included consideration of the
Point Loma WWTP remaining a primary treatment plant and potential
upgrade to a secondary treatment plant.
• A detailed present worth cost evaluation of the five primary management
options through 2030 lead to the following conclusions:
o Option A has the lowest present worth cost, followed by Option B
(expand RWCWRF to 2.6 MGD), then Option C. This is due to the
existing investment in RWCWRF and the avoidance of Metro costs and
additional recycled water purchases.
o Option D has the highest present worth due to the existing cost structure,
potential for Point Loma WWTP upgrade, and need to purchase
additional Metro and County system capacity.
o The lowest cost options involve onsite solids handling, purchase of
recycled water from a Chula Vista WRF, and avoidance of costs for a
Point Loma WWTP upgrade.
o For all RWCWRF expansion options (Options A, B, and C), construction
and operation of onsite solids handling is more cost-effective due to the
potential to reduce Metro discharges and costs.
o Abandoning the RWCWRF and relying on Metro or a new joint
District/County WRF is significantly more costly than retaining RWCWRF
at any of the three capacities evaluated. This reinforces the value of the
existing plant and the District’s Metro/County system capacity ownership.
May 2013 5
Wastewater
Management
Plan
o Purchase of recycled water from a new Chula Vista WRF appears to be
more cost-effective than purchase from the SBWRP due to the current
“take or pay” provision in the SBWRP agreement.
Wastewater Collection System Recommendations
Hydraulic Model
The existing hydraulic model was last calibrated in 2006 and should be recalibrated in
the next planning effort. Typically, a hydraulic model is calibrated every 5 years as
changes in development occur or modeled system components (pump stations and
pipelines) are updated. The District should also consider calibrating the model using
predictive hydrologic methods in the next model update. In terms of versatility and
range of applications, the predictive hydrologic method far exceeds the capabilities of
the peaking factor methodology which is currently utilized.
Recommended Wastewater System Improvements
Table ES-1 summarizes the schedule and capital cost opinions for the recommended
wastewater collection system improvements. Figures ES-1 and ES-2 illustrate the
recommended improvements.
Table ES-1. Recommended Wastewater Collection System Improvements
Project No. Description Location
Unit Cost ($/LF)1
Conceptual Cost Opinion ($)
Existing 2030
Collection System Pipes
CIP #1 12-inch 36 LF Near Fury Ln and Jamacha Rd 1,020 $37,000 --
CIP #2 24-inch 91 LF Near Hillsdale Rd and Jamacha Rd 2,040 $190,000 --
CIP #3 15-inch 9,225 LF Along Campo Road from Avocado Rd to Singer Lane 900 $8,300,000 --
CIP #4 15-inch 900 LF Near Jamacha Rd and Donahue Dr 1,275 -- $1,150,000
CIP #5 15-inch 1,235 LF Along Ivanhoe Ranch Rd upstream of Cottonwood Pump Station 1,275 -- $1,570,000
Total $8,527,000 $2,720,000
Note: 1. January 2012 Costs (ENR CCI = 9176). Includes 30% for engineering and administration, 10% for contractor bonding and insurance, and 30% for project contingencies.
CIP #3 involves replacement of the former 10-inch forcemain in Campo Road that
currently acts as a gravity pipe. The entire stretch of this pipe should be replaced with
a new 15-inch gravity sewer pipe.
May 2013 6
Wastewater
Management
Plan
Figure ES-1 Existing System Improvements
May 2013 7
Wastewater
Management
Plan
Figure ES-2 Future System Improvements
May 2013 8
Wastewater
Management
Plan
Recommended Wastewater Management and Recycled Water Strategies
The recommended wastewater and recycled water management strategies for
consideration by the District are as follows.
• Retain and maintain the RWCWRF at its current capacity. This
recommendation, however, does not preclude a future expansion of
RWCWRF capacity if additional reclaimed water for the District cannot be
obtained from a new assumed Chula Vista WRF or from the SBWRP.
• If regulatory restrictions prohibit the use of the existing reclaimed water
pipeline to achieve required chlorine contact times before expansion of the
RWCWRP, then plan, design, and construct a chlorine contact chamber. The
estimated capital costs for the chlorine contact chamber is $3,420,000
(includes 30 percent for engineering and administration, 10 percent for
contractor bonding and insurance, and 30 percent for project contingencies).
• Plan, design, and construct on-site solids handling facilities on the RWCWRF
site for a capacity of 1.3 MGD expandable to 2.6 MGD. The estimated
capital cost for the on-site solids handling facilities is $5,690,000
(includes 30 percent for engineering and administration, 10 percent for
contractor bonding and insurance, and 30 percent for project contingencies).
• Target the start-up date for RWCWRF on-site solids handling as early as
possible, but no later than 2015, to avoid potential Point Loma WWTP
upgrade costs.
• Confirm that construction and operation of RWCWRF on-site solids handling
facilities will preclude significant discharge to the Metro System, except on
plant maintenance or emergency events.
• Upon construction of RWCWRF on-site solids handling, re-determine new
quality and resulting unit costs for Metro discharge.
• Renegotiate the SBWRP recycled water purchase agreement to allow short-
term, peak month and peak-day purchases of recycled water from the 6
MGD limit stated in the contract to a new limit of 12 MGD. Also, renegotiate
the agreement to remove the “take or pay” provision.
• If the take or pay provision of the SBWRP agreement cannot be negotiated
out, support the construction of a Chula Vista WRF and negotiate a contract
to take all recycled water produced by that plant.
• Perform a District recycled water storage evaluation to assess daily and
peak month water balances to assure that projected peak period recycled water demands can be achieved by the combination of RWCWRF,
SBWRP/Chula Vista WRP recycled water purchases with no or little supplementation by other water sources, such as SDCWA water.
May 2013 9
Wastewater
Management
Plan
1.0 INTRODUCTION
1.1 Background
The Otay Water District (District) is located in the southern portion of San Diego
County. The District provides wastewater service to a portion of the land area within
the Jamacha Basin, which is located within its North District. The County of San Diego
also provides wastewater service in a portion of Jamacha Basin. Wastewater flows
from each agency customers are conveyed in joint collection and pumping systems.
Wastewater generated in Jamacha Basin can be discharged into the City of San Diego
Metropolitan Wastewater System (Metro System) up to the District and County contract
capacity rights in the system. The District owns and operates the Ralph W. Chapman
Water Reclamation Facility (RWCWRF) within the Jamacha Basin. The RWCWRF is
operated as a skimming or stripping facility, whereby wastewater flows generated
within Jamacha Basin are pumped to the RWCWRF and treated to produce recycled
water, which is used to meet a portion of the District’s existing recycled water irrigation
demand. All of the remaining wastewater flows are discharged into the Metro System
via the County’s Rancho San Diego Outfall Facilities (RSDOF) and the downstream
Spring Valley Outfall (SVO). The District has capacity rights within the RSDOF and the
SVO of 1.2 MGD, and slightly more in the Metro System. The design capacity of the
RSDOF is 4.5 MGD. The 2010 wastewater collection rates within the Jamacha Basin
from connected sewer customers was about 1.3 MGD for the District and about 0.65
MGD for the County.
There are currently two sources of recycled water supply to the District. The
RWCWRF can treat up to 1.3 MGD of wastewater to produce recycled water to meet a
portion of the District’s demands. The District also entered into an agreement with the
City of San Diego in 2003 that provides for recycled water supply from the City’s South
Bay Water Reclamation Plant (SBWRP). The agreement allows the District to
purchase up to 6.0 MGD of recycled water generated by the SBWRP.
Previous planning studies have evaluated various wastewater treatment and disposal
options available to the District and the County. These studies have indicated that
local treatment and marketing of recycled water are the economical and preferable
outcome under certain conditions, and Metro System wastewater disposal is superior
under other conditions. The primary factors affecting the comparison of the options
available are total wastewater collected for disposal, total costs of local and Metro
May 2013 10
Wastewater
Management
Plan
System service, revenues from the sale of recycled water, and risk exposure to future
costs in the Metro System.
1.2 Project Purpose and Scope
The purpose of this project is to prepare a comprehensive wastewater management
plan that considers required improvements to the District’s wastewater collection
system and identifies a preferred strategy for future wastewater management and
recycled water generation and purchase. The project also includes assistance in the
preparation of a State of California Program Environmental Impact Report, which
encompasses the recommendations of the Wastewater Management Plan. The scope
of services for the project generally includes the following:
• Update of the wastewater flow projections for the Jamacha Basin.
• Analysis of the wastewater collection system using the District’s existing
wastewater system hydraulic model to identify existing system deficiencies
and to identify system improvements and costs that will correct deficiencies
and accommodate projected wastewater flows.
• Analysis of existing and projected recycled water demands to determine
additional recycled water supplies that are needed currently and through
2030.
• Review of potential sources and costs of additional recycled water supplies.
• Identification and analysis of local and regional options available to the
District for future wastewater management and recycled water generation
and purchase to identify a preferred strategy or strategies.
• Development of a capital improvement program for the recommended
collection system and wastewater facility improvements.
• Assistance in the preparation, public noticing, and regulatory approval of the
Program Environmental Impact Report (PEIR) that encompasses the
Wastewater Management Plan recommendations.
This Wastewater Management Plan contains the findings and results of the first six
bullet items above. The PEIR assistance and documentation is provided separately.
May 2013 11
Wastewater
Management
Plan
2.0 WASTEWATER FLOW PROJECTIONS
This chapter presents updated wastewater flow projections through 2030, including
flows from San Diego County and Otay Water District collection service areas.
2.1 Study Area
The study area for this Wastewater Management Plan is the watershed drainage basin
known as the Jamacha Basin, which is located in the northern portion of the District’s
water service area. Figure 2-1 shows the Jamacha Basin and the boundaries of the
District’s water service area in relation to the wastewater collection area. As shown on
Figure 2-1, the Jamacha Basin includes a portion of San Diego County’s wastewater
service area in addition to the District’s service area. The 16,820-acre Jamacha Basin
drains to the Rancho San Diego Pump Station (RSDPS) that is owned and operated
by the County and is located on Singer Lane just off of Campo Road. The RSDPS
pumps wastewater collected from the Jamacha Basin to the County SVO facilities. Just
upstream of the RSDPS, the District’s Steele Bridge Pump Station (SBPS) diverts up
to 1.3 MGD of wastewater to the District’s RWCWRF. The RWCWRF treats up to 1.3
MGD of wastewater and has recently produced an average of 1.0 MGD of recycled
water. Treatment solids and sludge are pumped back to the RSDPS. The remaining
flows from the District and County service areas and RWCWRF solids and sludge are
pumped to the SVO, and the flow continues to the Metro System and ultimately to the
Metro System Point Loma Wastewater Treatment Plant (WWTP) for treatment and
disposal.
The District currently provides sewer service to over 4,000 customers within the
Jamacha Basin, and has the latent powers to provide sewer service to potential future
sewer customers in the study area. Most current District wastewater customers are in
areas west of the County of San Diego Policy I-107 Urban Limit Line as shown on
Figure 2-1.
May 2013 12
Wastewater
Management
Plan
Figure 2-1 Study Area
May 2013 13
Wastewater
Management
Plan
2.2 Previous Wastewater Flow Projections
In April, 2010, the County completed the most recent wastewater flow projections for
the Jamacha Basin as part of its RSDPS Sewer Flow Projection Study. The study was
a precursor to the preliminary design phase for upgrading pumping and wet well
capacity at the RSDPS. The County based this effort on the San Diego Association of
Governments (SANDAG) 2030 Regional Growth Forecast population projections.
Specifically, the population projections of the Series 11 – 2030 San Diego Regional
Growth Forecast Update, completed in April 2008, were utilized.
Unit per capita wastewater generation rates were developed and calibrated to
wastewater flows monitored by the County. The calibrated unit flow factors were 80
gallons per capita per day (80 gpcd) for residential populations and 25 gpcd for
employment populations. Typical design and planning standards for agencies in San
Diego County assume per capita wastewater generation rates between 60 to 100 gpcd
for residential and 15 to 35 gpcd for employment populations. Therefore, the calibrated
unit generation rates fall within industry standards.
The County cross-referenced populations with permitted parcel data to determine
existing and projected population for properties with existing sewer permits from either
agency. The balance of the population projections were attributed to vacant parcels
and parcels that were occupied but did not have a sewer permit.
The methodology for developing parcel-based wastewater flow projections in the 2010
County study is used in this Wastewater Management Plan. Updated (2012)
population projections from SANDAG were utilized, and unit wastewater flow factors
are calibrated to recent District wastewater metering data.
2.3 Population Projections
Population projections of the Series 12 – 2030 San Diego Regional Growth Forecast
Update, completed in May 2012, were obtained from SANDAG. SANDAG provided
the projections for Master Geographic Reference Areas (MGRAs), which are similar in
size to census blocks in urban areas and census block groups in suburban and rural
areas. Property parcel data in GIS was then overlaid on the MRGA data to develop
population data at the parcel level. The data included residential population estimates
for 2008 through 2030 and employment estimates for 2015 through 2030. SANDAG
indicated that employment population estimates for 2008 and 2010 were not available
due to confidentiality concerns. Table 2-1 summarizes the population projections
May 2013 14
Wastewater
Management
Plan
provided by SANDAG. The SANDAG data was cross-referenced with parcels that had
wastewater permits from either agency to identify permitted parcels which are
connected to the wastewater system. Unpermitted (unconnected) parcels were either
designated as vacant or on individual septic systems (occupied parcels that were
categorized as unpermitted were assumed to be on septic). Figure 2-2 shows the
parcels within the District service area that are assumed to be on septic.
Table 2-1. Existing and Projected Populations within the Jamacha Basin1
Notes:
1. SANDAG Series 12 Forecast. Res – Residential, Emp – Employment. 2. Occupied but unpermitted parcels assumed to be on septic.
3. Employment population not available from SANDAG. 4. Includes unconnected parcels in both County and District service areas.
2.4 Calibration of Unit Wastewater Flow Factors
A calibration check was made of the unit wastewater generation factors used by the
County in its 2010 study. The calculated 2008 and 2010 wastewater flows using the
unit factors were compared against the District’s wastewater flow monitoring data.
Table 2-2 summarizes the calibration check. The County is currently updating its
wastewater master plan for the portion of its service area that includes the Jamacha
Basin. The County provided its most recent population projections, which had been
updated since its 2010 RSDPS study (although the updates were also based on the
Series 11 data). The employment population estimates for 2008 and 2010 provided by
the County were used to calibrate unit wastewater flow factors.
Year
Permitted/Connected Unconnected4 Total County District Vacant Septic2
Res Emp3 Res Emp3 Res Emp3 Res Emp3 Res Emp3
2008 8,956 -- 16,390 -- 2,176 -- 3,635 -- 31,157 --
2010 7,351 -- 15,790 -- 2,156 -- 3,641 -- 28,938 --
2015 9,101 2,011 16,817 2,768 2,207 731 3,691 1,087 31,816 6,597
2020 9,136 2,020 16,931 2,806 2,591 735 3,697 1,107 32,355 6,668
2025 9,262 2,020 17,179 2,807 2,907 737 4,633 1,116 33,981 6,680
2030 9,288 2,018 17,532 2,817 3,099 741 4,722 1,137 34,641 6,713
May 2013 15
Wastewater
Management
Plan
Figure 2-2 Wastewater Generation Parcels
May 2013 16
Wastewater
Management
Plan
Table 2-2. Calibration Summary of Unit Wastewater Generation Factors
Year
Total County and District Permitted/Connected
Populations Total County and District Calculated Wastewater Flows2
(MGD)
Total District
Metered Flows
(MGD)
Percent
Difference Residential Employment1
2008 25,346 5,592 2.17 2.06 - 5%
2010 23,141 5,335 1.98 1.97 - 1%
Notes:
1. From County-provided (January 2012) most recent updates of SANDAG Series 11 data. 2. Based on 80 gpcd for Residential and 25 gpcd for Employment populations.
The calibration check of the unit wastewater factors indicate a maximum difference
between calculated and metered wastewater flows of 5 percent. This is considered
acceptable for master planning purposes. Thus, the unit factors of 80 gpcd for
residential and 25 gpcd for employment populations were used in updating the
wastewater flow projections.
2.5 Wastewater Flow Projections
Table 2-3 summarizes the updated wastewater flow projections for the Jamacha Basin.
The table includes estimated flows from the Sycuan Indian Reservation as
documented in the Final Environmental Assessment, Sycuan Band of the Kumeyaay
Nation Fee-to-Trust (August 2011). The environmental assessment covers, among
other activities, construction of economic developments on the Reservation, including
an Outdoor Events Center with limited parking for recreational vehicles (RVs) operated
in conjunction with the existing Sycuan Resort; relocation of the Tribe’s Equestrian
Center to maximize use of existing trails near the Sycuan Property; creation of
additional Tribal housing to accommodate Tribal growth; and, construction of
permanent facilities for the Tribe’s annual Pow Wow event. Figure 2-2 also shows the
location of the planned Sycuan developments. The Sycuan development will become
part of the District’s service area, and it is assumed that all facilities will be in place and
operating by 2020.
May 2013 17
Wastewater
Management
Plan
Table 2-3. Updated Wastewater Flow Projections for the Jamacha Basin
Year
District County
Basin Total Permitted/ Connected
Unconnected Sycuan District Total Permitted/ Connected
Unconnected County Total Vacant Septic Vacant Septic
2010 1.35 0.18 0.32 0 1.84 0.64 0 0 0.64 2.48
2015 1.41 0.18 0.32 0 1.92 0.78 0 0 0.78 2.70
2020 1.42 0.20 0.32 0.02 1.97 0.78 0.03 0 0.81 2.78
2025 1.44 0.23 0.40 0.02 2.09 0.79 0.02 0 0.81 2.91
2030 1.47 0.25 0.41 0.02 2.15 0.79 0.02 0 0.81 2.96
Most current District and County wastewater customers are in areas west of the
County of San Diego Policy I-107 Urban Limit Line as shown on Figure 2-2. This line
reflects a regional planning policy that has generally restricted urban development in
the area to the east of the line. Discussions are currently underway regarding the
future of this policy. The disposition of the policy is currently unknown.
Table 2-4 summarizes the wastewater flow projections for the District’s wastewater
service area only and delineates the portion of wastewater flows that are generated
west and east of the County of San Diego Policy I-107 Urban Limit Line.
Table 2-4. Updated Wastewater Flow Projections for District Service Area
Year
West of I-107 Urban Limit Line East of I-107
Urban Limit Line2
(MGD)
Total
(MGD)
Permitted/ Connected
(MGD)
Unconnected1
(MGD)
Subtotal
(MGD)
2010 1.23 0.23 1.46 0.38 1.84
2015 1.30 0.26 1.56 0.38 1.93
2020 1.31 0.28 1.59 0.39 1.97
2025 1.33 0.31 1.64 0.46 2.09
2030 1.35 0.33 1.68 0.47 2.15
Note: 1. Includes unconnected parcels within the District service area only.
2. Includes Sycuan flows.
THIS PAGE INTENTIONALLY LEFT BLANK
May 2013 18
Wastewater
Management
Plan
3.0 WASTEWATER COLLECTION SYSTEM ANALYSIS
This chapter summarizes the hydraulic modeling of the District’s wastewater collection
system for existing and projected future wastewater flow conditions. The modeling
results are used to: 1) identify existing system deficiencies, develop recommendations
to correct the deficiencies, 3) and determine system improvements to accommodate
future growth, and 4) develop estimated improvement costs.
3.1 Existing Wastewater Collection System
The 16,820-acre Jamacha Basin drains to the RSDPS that is owned and operated by
the County and is located on Singer Lane just off of Campo Road. The RSDPS pumps
wastewater collected from the Jamacha Basin to the SVO facilities. Just upstream of
the RSDPS, the District’s SBPS diverts up to 1.3 MGD of wastewater to the RWCWRF.
The RWCWRF treats up to 1.3 MGD of wastewater and has recently produced an
average of 1.0 MGD of recycled water, and returned an average of 0.3 MGD of solids
and sludge to the RSDPS. The remaining flows from the District and County service
areas are pumped to the SVO, and the wastewater continues to flow to the Metro
System and, ultimately, to the Point Loma WWTP for treatment and disposal.
The District’s existing wastewater system that was evaluated includes the RWCWRF,
pump stations, and collection system pipes. Figure 3-1 illustrates the existing
wastewater collection system within the Jamacha Basin.
3.1.1 Ralph W. Chapman Water Reclamation Facility
The District owns and operates the RWCWRF. The existing capacity of the RWCWRF
is 1.3 MGD, and the facility is located on a site master-planned for an ultimate build-out
capacity of 3.9 MGD.
May 2013 19
Wastewater
Management
Plan
Figure 3-1 Existing Collection System
May 2013 20
Wastewater
Management
Plan
Influent flows to the RWCWRF are conveyed through a 12-inch forcemain from the
SBPS. The RWCWRF is a scalping plant, and not all flows from the District
wastewater service area are conveyed to the facility. A concrete weir structure near
the SBPS diverts flow to the SBPS, and the remaining flow continues to the RSDPS.
The RWCWRF employs a series of physical, biological, and chemical processes for
advanced treatment of wastewater to yield Title 22 reclaimed water. The plant does
not have solids handling facilities. Solids are pumped back to the RSDPS, which, in
turn, pumps the wastewater to the SVO.
3.1.2 Pump Stations
The wastewater system has 6 pump stations, as shown on Figure 3-1. Information on
the pump station equipment was originally obtained from the District’s existing
wastewater system hydraulic model (described in Section 3.2) and updated based on
information provided by District staff. Table 3-1 summarizes the characteristics of the
wastewater pump stations.
Table 3-1. Summary of Wastewater Pump Stations
* Information in the hydraulic model was updated based on information provided by the District.
The Cottonwood, Hidden Mountain and Russell Square Pump Stations convey
wastewater from within the collection system, where conveyance via gravity is not
feasible due to topography. The Calavo Pump Station does not operate continuously
and is used to divert flow from the Calavo drainage basin to the SVO facilities when the
RWCWRF is not operating at full capacity or is offline. The SBPS pumps the diverted
Pump Station
Number of Pumps
Total Design Capacity
(gpm)
Firm Capacity
(gpm)
Year Built or Last Refurbished
Wet Well
Cross
Section
Invert Elevation
(feet)
Depth
(feet) Diameter (feet)
Calavo 2 700* 350* 2008 Circular 504.15 20.13 9
Cottonwood 2 510 510 1996 Circular 323 22 8
Hidden
Mountain 2 100* 100* 1978 Circular 701.15 14.85 5
Russell Square 2 20* 20* 1984 Circular 783 10 5
Steel Bridge
(SBPS) 2 2,400* 1,200* 2008 Circular 299.4 9 9.292
Rancho San Diego (RSDPS) 3 4,500* 3,500* -- Variable 295.3 19.7 Variable
May 2013 21
Wastewater
Management
Plan
flow from the weir structure to the RWCWRF, and the RSDPS pumps the remaining
flow from the weir structure to the Spring Valley outfall facilities.
The pump station wet well characteristics derived from the District’s existing hydraulic
model are also summarized in Table 3-1.
3.1.3 Collection System Pipes
The wastewater system includes approximately 95 miles of collection system pipelines,
of which 92 miles are gravity sewers and 3 miles are force mains. The District owns
approximately 78 miles of the gravity sewers, and the rest is owned by the County, as
shown previously on Figure 2-1.
The gravity sewers range in diameter from 4 inches to 27 inches, with the vast majority
(84 percent) of the collection system being comprised of 8-inch diameter pipes. The
force mains range in diameter from 4 inches to 24 inches. The 4-inch and 6-inch force
mains are associated with the Hidden Mountain, Russell Square and Cottonwood
stations, while the 12-inch and 24-inch force mains are associated with the SBPS and
RSDPS, respectively.
Table 3-2 provides a summary of the collection system pipelines based on the
diameters and type of pipe.
May 2013 22
Wastewater
Management
Plan
Table 3-2. Summary of Collection System Pipes
Diameter
(Inch)
Gravity Sewers Force Mains
Length
(feet) % of Total
Length
(feet) % of Total
4 811 0.2 1,568 9.3
6 835 0.2 3,773 22.3
8 410,955 84.4 -- --
10 25,870 5.3 -- --
12 8,190 1.7 3,400 20.1
15 21,646 4.4 -- --
18 10,226 2.1 -- --
21 2,678 0.5 -- --
24 603 0.1 8,188 48.3
27 5,303 1.1 -- --
Total 487,117 100 16,929 100
3.2 Wastewater System Hydraulic Model
The District provided its existing wastewater system hydraulic model and supporting
planning documentation for use in this Wastewater Management Plan. The details of
the model development, model calibration, and planning analysis are documented in
the 2006 Sewer Model Calibration, Capacity Analysis, and System Assessment (2006
Study), which was a part of the District’s Sewer System Management Plan (SSMP,
completed in 2009).
3.2.1 Model Software and Modeled System
The District’s wastewater system hydraulic model was developed in H2OMAP Sewer,
Version 7.0 software. The model is an all-pipes model. The entire infrastructure
described in the previous section has been included in the model. The RWCWRF is
modeled as an outfall, and the return solids line from the RWCWRF to the RSDPS is
not included in the model. The concrete diversion structure splitting flow between the
SBPS and the RSDPS is modeled as a manhole.
May 2013 23
Wastewater
Management
Plan
H2OMAP Sewer can run both steady state and extended period analyses. The
District’s hydraulic model was calibrated under extended period analysis for the dry
weather flow condition, and steady state analysis was performed using the peaking
factor methodology for the peak flow condition.
The average daily flow in the model’s “existing system scenario” is 2.1 MGD (the last
model runs were completed in 2006). Of this total flow, 1.9 MGD came from residential
sources, and 0.2 MGD came from commercial sources. Separate diurnal patterns
were assigned to each load type – residential and commercial.
3.2.2 Model Calibration
The District last calibrated the hydraulic model in 2006 based on data collected from 11
open channel flow meters in 2005. The flow monitoring was performed between
January 25, 2005 and March 25, 2005. The model was calibrated for flow on February
8th and February 9th, 2005, which was the driest 2-day period during these two months.
Figure 3-2 shows the meter locations and the associated upstream pipes associated
with the monitored basins. After model calibration, the collection system was modeled
using the peaking factor method. The peaking factors used in the 2006 Study were
applied to the updated wastewater flow projections to determine updated peak flow
loading conditions. Table 3-3 summarizes the peaking factors developed and used in
the 2006 Study. The peak wet weather to average dry weather factor (last column in
Table 3-3) was applied to the updated wastewater loadings for each monitored basin.
Table 3-3: Peaking Factors
Flow Meter Basin Peak Dry Weather to Average Dry Weather Factor Peak Wet Weather to Peak Dry Weather Factor Peak Wet Weather to Average Dry Weather Factor
OT01 1.36 1.70 2.32
OT02 1.78 1.60 2.85
OT03 2.85 1.40 3.98
OT04 1.46 1.50 2.19
OT05 1.53 2.70 4.13
OT06 2.84 1.70 4.82
OT07 1.89 1.60 3.02
OT08 1.95 2.10 4.10
OT09 2.13 3.00 6.38
OT10 1.67 2.50 4.16
OT11 1.40 1.80 2.53
May 2013 24
Wastewater
Management
Plan
Figure 3-2 Flow Meter Basins
May 2013 25
Wastewater
Management
Plan
3.2.3 Assessment of Existing Hydraulic Model
A cursory review was conducted on the District’s existing hydraulic model to determine
functionality and suitability for use in the Wastewater Management Plan. The model
was found to be complete and suitable for master planning purposes. However, the
following minor limitations should be considered in the next major update of the model
(addressing the limitations was not within the scope of services for this Wastewater
Management Plan).
The model was last calibrated in 2006. Typically, a hydraulic model is calibrated every
5 years, since during this time period new development (or population decline) within
the system can cause changes in the system flows, and, as the existing pipes age,
rainfall derived infiltration and inflow (RDII) responses may change. The model should
also be calibrated when changes are made to the modeled systems. For example, the
pump station modifications previously presented in Section 3.1.2 and other model
updates described later in Section 3.2.5 could significantly affect model calibration.
The calibration was also performed using a peaking factor methodology. The peaking
factor methodology entails the application of a factor to convert average dry weather
flow into peak wet weather flow. This methodology does not provide any information on
the type of storm which causes the peak flows. This does not mean that the
methodology is flawed, just that the model will only predict the exceedance in the
infrastructure and not the frequency of exceedance.
The District should consider calibrating the model using predictive hydrologic methods
in the next model update. In terms of versatility and range of applications, it far
exceeds the capabilities of the peaking factor methodology. The hydrologic method
uses traditional surface hydrology methods to mimic the RDII response and provides a
flexible model capable of representing the desired wide range of wet weather
conditions. The hydrologic method will predict not only the peak flow but the entire RDII
hydrograph. It also allows for a calibrated model to be used as a planning tool by
applying a storm that was not part of the calibration period (either a synthetic design
storm or an actual historic storm event of record) to the system for planning level
evaluation and for conceptual sizing of improvements. This could be important since
the District could develop an understanding of the level of control that system
improvements might provide (e.g., the frequency, typically in terms of a design storm,
beyond which capacity could be exceeded or during which proposed facilities will be
expected to perform).
May 2013 26
Wastewater
Management
Plan
3.2.4 Model Use in the Wastewater Management Plan
The District’s existing hydraulic model, with the minor updates to the modeled system,
was utilized similar to the modeling last conducted in 2006. The model was further
updated with current base wastewater loads from updated wastewater flow projections.
Updated wastewater flow projections were described and presented in Chapter 2.
Peak flows were determined by applying the previously determined peaking factors to
the projected dry weather flows. As indicated in Chapter 2.0, most current District and
County wastewater customers are in areas west of the I-107 Urban Limit Line. Since
the disposition of the policy behind the line is currently unknown, the wastewater
system evaluations focus only on the existing system, and projected wastewater flows
are added at the closest model node (manhole) within the specific wastewater
drainage basin to assess impacts to the existing system due to future flows.
3.2.5 Hydraulic Model Updates
In addition to the updates made to the pump stations noted in Table 3-1 previously, the
model was reviewed and compared to recent information to determine if any additional
model elements needed to be updated. There were some locations where the attribute
information stored within the modeling database appeared to be incorrect. These were
limited to mostly invert elevations that caused significant adversely sloped sewer
pipelines that often resulted in surcharged condition in the immediate upstream
sewers. The attribute information was corrected, as summarized below in Table 3-4.
Table 3-4. Hydraulic Model Invert Elevation Updates
Model Link ID
Pipe Diameter (Inch) Location Comments
SM1369 8 Sundale Road Upstream Invert Changed
SM1034 10 Near Jamacha Road and Hillsdale Road Upstream Invert Changed
SM1524 12 Near Lasven Ct and Ivanhoe Ranch Road Upstream Invert Changed
SM1525 12 Near Lasven Ct and Ivanhoe Ranch Road Upstream Invert Changed
SM1566 8 Near Stonefield Dr and Tamara Ct Upstream Invert Changed
SM1720 8 Near Cuyamaca College Dr and Jamacha Rd Upstream Invert Changed
A comparison was also made of the District’s modeled system and a modeled system
database obtained from San Diego County, which is currently conducting a wastewater
master planning effort for its service area, which includes the Jamacha Basin. Several
May 2013 27
Wastewater
Management
Plan
differences were noted and provided to the District, which had the differences field
verified. After field verification, the updates noted in Table 3-5 were made to the
hydraulic model.
Table 3-5. Hydraulic Model Pipe Size Updates
Location
Pipe Size in District Model
(inch)
Pipe Size in County Model
(inch) Update Made
Length
(feet)
Vista Rodeo Dr 10 8 10-inch to 8-inch 278
Pine Glen Ln 15 8 15-inch to 8-inch 1,062
Willow Glen Ln 15 8 15-inch to 8-inch 227
Rancho San Diego 15 21 15-inch to 21-inch 346
Brabham St 8 10 8-inch to 10-inch 400
Lastly, several capital improvement program (CIP) projects have been completed since
2005 or are in progress. These CIP projects listed in Table 3-6 below were added to
the model and were modeled as existing system elements.
Table 3-6. CIP Projects Added to the Hydraulic Model
Location Update Made Length (feet) Source
Avacado Blvd New 15-inch PVC Pipe 1,601 CIP S2019, S2020 and S2022
Hidden Mesa Rd New 8-inch PVC
Pipe 313 CIP S2019, S2020
and S2023
Louisa Dr New 8-inch PVC Pipe 985 CIP S2019, S2020 and S2024
Calavo Dr and
Challenge Blvd
New 8-inch PVC
Pipe 431 CIP S2019, S2020
and S2025
3.3 Analysis of Existing System
The updated wastewater flow estimates for 2010 were used to simulate existing flow
conditions within the wastewater system. The existing flows and peaking factors were
used to develop updated peak loading conditions, which were then imported into the
hydraulic model.
May 2013 28
Wastewater
Management
Plan
3.3.1 Evaluation Criteria
Table 3-7 summarizes the wastewater system performance criteria that the District and
other surrounding jurisdictions use to size and evaluate collection systems.
Table 3-7. Wastewater System Performance Criteria
Parameter Criteria1
Peaking
Factor
Peak
Flow
Dry Weather Peaking Factors developed from 2006 Sewer
Model Calibration, Capacity Analysis, and System Assessment Report2 Wet Weather
Collection1
System
Pipes
Gravity
Design Criteria Peak Wet Weather Flow
Manning's Coefficient 0.01 - Old Pipes
0.011 or 0.013 depending on material - New Pipes
Minimum Velocity <= 12 inch - 2 ft/s under peak hour flow >15 inch - 2 ft/s under peak hour flow
Maximum Velocity <= 12 inch - 10 ft/s under peak hour flow
>15 inch - 10 ft/s under peak hour flow
Minimum Pipe Size 8 inch
Force Main
Design Criteria Peak Wet Weather Flow
Hazen Williams Coefficient 100 - Old Pipes
120 or 140 depending on material - New Pipes
Minimum Velocity 3.5 ft/s
Maximum Velocity 8 ft/s
Depth
Ratio1
Peak
Dry Weather
Future pipes Design < 12 inch - 0.5 > 12 inch - 0.75
Existing pipes Trigger: For all sizes - 1.03
Peak Wet Weather
Future pipes Design < 12 inch - 0.5 > 12 inch - 0.75
Existing pipes Trigger: For all sizes - 1.03
Pump
Stations1
Firm Capacity Largest pump out of service
Design Criteria Peak Hour Flow
Notes:
1. Source: Water Agencies' Standards (WAS): Design Guidelines for Water and Sewer Facilities
2. Criteria used in District’s 2006 SSMP.
3. Criteria added to assess existing pipes.
Sewer system capacity was determined based on surcharging conditions using the
peak water depth to diameter ratio (d/D). For all sewer pipelines less than 12 inches in
diameter, any d/D greater than 0.5 is assumed to have a capacity constraint. A d/D
May 2013 29
Wastewater
Management
Plan
ratio of 0.75 was used as a trigger for all sewers with a diameter of 12 inches or
greater. Pump stations were evaluated if the firm capacity (station capacity with the
largest pump out of service) was exceeded by the peak wet weather flow. Forcemain
velocities were used to determine the cause of the pump station’s firm capacity being
exceeded. If high forcemain velocities were noted at a station whose firm capacity was
exceeded, this would indicate that the capacity constraint is associated with the
forcemain. If a station’s firm capacity is exceeded but forcemain velocities are low, the
capacity constraint is typically associated with the station’s pumps being undersized.
3.3.2 Existing System Assessment
To analyze the existing system, loadings from all permitted/connected parcels were
assigned and imported to the hydraulic model. The existing average dry weather load
of 1.98 MGD was applied to the system. Using the evaluation criteria and peaking
factors described above, the existing collection was assessed to determine capacity
deficiencies during the peak wet weather loading conditions.
Figure 3-3 shows the results of the system assessment. Overall, the system
performed quite well under the peak loading conditions. None of the pump stations
had capacity concerns. There were some areas, however, where the system
performance exceeded the evaluation criteria for gravity sewers as summarized on
Table 3-8.
Table 3-8. Existing System Deficiencies
Name Location Criteria Violated
Area 1 Near Fury Ln and Jamacha Rd Manhole surcharging and d/D > 0.75
Area 2 Near Hillsdale Rd and Jamacha Rd Manhole surcharging and d/D > 0.75
Area 3 Along Campo Road from Avocado Rd to Singer Lane Manhole surcharging and d/D > 0.75
May 2013 30
Wastewater
Management
Plan
Figure 3-3 Existing System Assessment
May 2013 31
Wastewater
Management
Plan
3.3.3 Existing System Improvements
Each of the areas described above was reviewed to identify improvements to address
system deficiencies. The water level in manholes and depth to diameter ratios in pipes
were studied to assess if the criteria were only moderately violated, or if there was a
significant violation. If a manhole was flooded or the sewer was completely surcharged
(d/D > 1), then an improvement would be recommended. Areas that violated the
evaluation criteria, but had a d/D ratio less than 1, were considered not to be as critical
for improvements. It is recommended that the District observe these areas during high
flow conditions to verify if unacceptable surcharging does occur.
Based on the hydraulic modeling analysis, the recommended existing system
improvements are listed on Table 3-9 and shown on Figure 3-4. The areas that the
District should observe for unacceptable surcharging are also shown on Figure 3-4. It
should be noted that one of the improvements along Campo Road (Area 3) was
specifically requested by the District to convert a forcemain (currently operated as a
gravity sewer) to a traditional gravity sewer.
Table 3-9. Recommended Existing System Improvements
Area CIP
Existing
Pipe Size (inch) Recommendation
New Pipe
Size (inch) Length (feet) Slope
Area 1 #1 10 Replacement Pipe 12 36 0.002
Area 2 #2 15 Replacement Pipe 24 91 0.002
Area 3 #3 10 Replacement Pipe 15 9225 0.032
3.4 Analysis of Future Conditions
The updated wastewater flow projections and peaking factors were used to develop
future peak loading conditions, which were then imported into the hydraulic model to
assess future system conditions.
May 2013 32
Wastewater
Management
Plan
Figure 3-4 Existing System Improvements
May 2013 33
Wastewater
Management
Plan
3.4.1 Future System Assessment
Initially, the flow projections for 2030 were modeled to determine future system
improvements. The hydraulic network, including the improvements recommended in
Section 3.3, was used as a basis for assessing how the system will perform for the
projected 2030 loading conditions. The average 2030 wastewater loading from the
entire service area (2.94 MGD) was applied to the system along with the peaking
factors to assess the system under peak wet weather conditions. The future loading of
0.02 MGD from the Sycuan reservation was allocated at the upstream-most manhole
on Dehesa Road. The total average wastewater loading for this scenario was
therefore, 2.96 MGD. The same system performance criteria that were used for the
existing system assessment were used for the future system assessment.
Figure 3-5 shows the results of the future system assessment. Table 3-10 summarizes
the areas where violations of the system performance criteria were noted.
Table 3-10. Future System Deficiencies
Name Location Criteria Violated
Area 4 Near Fury Ln and Jamacha Rd Manhole surcharging and d/D >
1.0
Area 5 Along Ivanhoe Ranch Rd upstream
of Cottonwood Pump Station
Manhole flooding and d/D > 1.0
3.4.2 Future System Improvements
Each of the areas described above was reviewed to recommend improvements to
address system deficiencies. Similar to the existing system improvements, areas
where the d/D ratios were greater than 1.0 and observed flooded manholes were given
priority for improvements. None of the pump stations had capacity concerns under
2030 loading conditions. Table 3-11 summarizes the resulting system improvements
recommended for the 2030 flow conditions, the improvements are also shown on
Figure 3-6. Figure 3-6 also shows areas that the District should observe for any future
unacceptable surcharging conditions.
May 2013 34
Wastewater
Management
Plan
Figure 3-5 Future System Assessment
May 2013 35
Wastewater
Management
Plan
Figure 3-6 Future System Improvements
May 2013 36
Wastewater
Management
Plan
Table 3-11. Recommended System Improvements for 2030 Flow Conditions
Area CIP
Existing Pipe Size (inch) Recommendation
New Pipe Size (inch) Length (feet) Slope
Area 4 #4 10 Replacement Pipe 15 900 0.004
Area 5 #5 8 Replacement Pipe 15 1235 0.004 - 0.015
3.5 Summary of Recommended System Improvements & Conceptual Cost
Opinions
Conceptual capital cost opinions were developed for the recommended system
improvements described in the previous sections. The cost opinions are based on
available recent projects with similar components, manufacturer’s budget estimates,
standard construction cost estimating manuals, and engineering judgment. The level of
accuracy for the cost estimates corresponds to the Class 4 estimate as defined by the
Association for the Advancement of Cost Engineering (AACE) International. This level
of engineering cost estimating is approximate and generally made without detailed
engineering data and site layouts, but is appropriate for preliminary budget-level
estimating. The accuracy range of a Class 4 estimate is minus 15 percent to plus 20
percent in the best case and minus 30 percent to plus 50 percent in the worst case.
All cost opinions also include a 30 percent factor for engineering and construction
administration, 10 percent for Contractor bonding and insurance, and 30 percent for
project contingencies. All costs are in January 2012 dollars referenced to an
Engineering News Record Construction Cost Index (ENR CCI) of 9,176.
Table 3-12 summarizes the schedule and capital cost opinions for the recommended
system improvements. The estimated total capital cost for the recommended
infrastructure to correct existing deficiencies is $8.53 million. To accommodate 2030
wastewater flows, the additional capital cost is approximately $2.72 million.
May 2013 37
Wastewater
Management
Plan
Table 3-12. Summary of Recommended System Improvements
Project No. Description Location
Unit Cost ($/LF)1
Conceptual Cost Opinion ($)
Existing 2030
Collection System Pipes
CIP #1 12-inch 36 LF Near Fury Ln and Jamacha Rd 1,020 $37,000 --
CIP #2 24-inch 91 LF Near Hillsdale Rd and Jamacha Rd 2,040 $190,000 --
CIP #3 15-inch 9,225 LF Along Campo Road from Avocado Rd to Singer Lane 900 $8,300,000 --
CIP #4 15-inch 900 LF Near Jamacha Rd and Donahue Dr 1,275 -- $1,150,000
CIP #5 15-inch 1,235 LF Along Ivanhoe Ranch Rd U?S of Cottonwood Pump Station 1,275 -- $1,570,000
Total $8,527,000 $2,720,000
Note: 1. January 2012 Costs (ENR CCI = 9176). Includes 30% for engineering and administration, 10% for contractor bonding and insurance, and 30% for project contingencies.
May 2013 38
Wastewater
Management
Plan
4.0 RECYCLED WATER SUPPLY ANALYSIS
For over 30 years, the District’s Board has pursued a recycled water program based on
the fundamental belief that, by developing and utilizing recycled water, the need for
imported water use within the District can be reduced. Section 26 of the District’s Code
of Ordinances states that “reclaimed water shall be used within the jurisdiction
wherever its use is financially and technically feasible, and consistent with legal
requirements, preservation of public health, safety and welfare, and the environment.”
This policy provides the District the opportunity to plan, fund, and construct facilities to
meet projected recycled water market demands. The uncertainty of water supply in
San Diego County and the recent drought conditions make recycled water a viable and
critical reliable supply to meet future growth needs. This chapter presents an analysis
of projected recycled water demands and recycled water supplies.
4.1 Recycled Water Distribution Facilities
The District operates and maintains over 77 miles of recycled water transmission and
distribution pipelines, pump stations, and reservoirs and currently serves recycled
water customers primarily within its Central Area System, south of the Sweetwater
Reservoir and west of the Otay Lakes Reservoirs.
The District’s Central Area continues to grow and is characterized by large master-
planned developments. The District will continue to require developers to connect to
the recycled water system to serve irrigation demands. Otay Mesa is also a growing
part of the District with significant planned industrial development. Anticipating that a
recycled water supply will become available, developers in Otay Mesa have also been
constructing dual distribution pipelines for over twenty years. The District will continue
to construct reservoirs, pump stations, and transmission mains that will incorporate
these distribution pipelines into a complete delivery system.
4.2 Existing Recycled Water Supplies
The District currently has two sources of recycled water supply: recycled water
produced locally at the RWCWRF and, through an agreement with the City of San
Diego, recycled water produced at the City of San Diego’s SBWRP.
May 2013 39
Wastewater
Management
Plan
4.2.1 Recycled Water from the RWCWRF
The RWCWRF was originally constructed in 1979 and was upgraded in 1990 to its
current rated design capacity of 1.3 MGD. At the design flow, the RWCWRF has
recently produced an average of 1.0 MGD of recycled water. However, on a peak
demand day, the RWCWRF has been operated to produce a supply of 1.2 MGD. In
2011, the RWCWRF provided a recycled water supply of 1,077 acre-feet (AF) to the
District.
The RWCWRF provides tertiary treatment that meets the State of California’s Title 22
requirements for reuse. The recycled water is pumped to two lined and covered
reservoirs 3.4 miles south of the RWCWRF. The recycled water pump station at the
RWCWRF consists of 5 pumps with a total capacity of 3,500 gpm (5 MGD) and a firm
capacity (with the largest pump out of service) of 2,600 gpm (3.7 MGD). The 14-inch
diameter force main to the reservoirs serves as a vessel to fulfill the Title 22
requirement of 450 milligram-minutes per liter of chlorine contact time before the
recycled water can be used.
4.2.2 Recycled Water from the SBWRP
In order to serve existing demand for recycled water without supplementing with
potable water, the District entered into an agreement to purchase recycled water from
the City of San Diego’s SBWRP in October, 2003. The SBWRP has a rated capacity
of 15 MGD and is located at Monument and Dairy Mart Roads near the international
border with Mexico. The SBWRP receives wastewater from a pump station that scalps
flow from the Metro System interceptor that conveys flow northward to the Point Loma
WWTP for treatment and ocean outfall disposal. The agreement entitles the District to
purchase up to a maximum amount of 6 MGD of recycled water at any time. The term
of the agreement is 20 years from January 1, 2007. The agreement establishes
annual contract amounts that the District must pay for, even if it cannot take all the
recycled water. In 2011, the District purchased 2,803 AF of recycled water from the
SBWRP compared to that year’s annual required take amount of 4,044 AF. The
District pays a commodity rate of $350 per AF for the recycled water supply. The
commodity rate is subject to escalation at the same rate adopted by the City Council
for its other reclaimed water customers. In 2011, the commodity rate remained at $350
per AF.
The agreement stipulates that the City will meet all applicable federal, state and local
health and water quality requirements for recycled water produced at the SBWRP to
May 2013 40
Wastewater
Management
Plan
the point of delivery. Also, as part of the agreement, in 2007 the District completed
construction of a 30-inch transmission main to deliver the recycled water from the point
of delivery to the District service area. The City retains 1 MGD of capacity in this
transmission pipeline that runs through the City’s system. The recycled water pump
station at the SBWRP has two 3,500 gpm pumps with a total capacity of 7,000 gpm (10
MGD).
The actual availability of recycled water from the SBWRP has recently been about 5.3
MGD due to wastewater availability, other large demands taking priority, etc. The
District and other water agencies are pushing the City of San Diego to complete
projects that will direct more wastewater flows to the SBWRP and increase supply
reliability. The City has a new capital improvement program that will start addressing
these issues over the next couple of years. Thus, the supply from the SBWRP will be
about 5.3 MGD until 2015 whereby it will increase to the agreement’s 6 MGD.
4.3 Existing and Projected Recycled Water Usage
The District currently provides recycled water service to 684 customers who used
approximately 3,880 AF of recycled water in 2011. Current recycled water uses
include commercial landscape irrigation, golf course irrigation, and irrigation of public
areas such as parks, streetscapes, schools, highway medians, and open space areas.
The Olympic Training Center facility in Chula Vista also uses recycled water to irrigate
practice fields and common areas.
The District is committed to expanding the recycled water system in order to further
reduce future dependence on imported water. Areas with the greatest potential for
expansion include the existing Central and Otay Mesa areas, discussed previously,
and the North District area. The District plans to maximize the use of recycled water in
these areas by converting large potable irrigation users to recycled water and
continuing to require new developments within the District to use recycled water,
wherever feasible. The District estimated future recycled water demands based on
known sub-area master plan and general plan land uses and applying irrigated area
percentages and recycled water irrigation duty factors. Table 4-1 provides a summary
of the District’s actual 2010 recycled water usage and projected recycled water
demands through 2035.
May 2013 41
Wastewater
Management
Plan
Table 4-1. Projected Recycled Water Demands1
Year
2010 2015 2020 2025 2030 2035
Demand (AFY)2 4,074 4,400 5,000 5,800 6,800 8,000
Notes:
1. Source, Otay Water District 2010 Urban Water Management Plan (adopted June
1, 2011). 2. Acre-feet per year (AFY)
4.4 Comparison of Recycled Water Demands and Existing Supplies
The current effective capacity of the RWCWRF is 1.0 MGD, or 1,120 AFY. The
maximum supply from the SBWRP is currently 5.3 MGD (5,940 AFY) and will increase
to 6 MGD, or 6,720 AFY in 2015. Thus, the two existing recycled supply sources could
provide up to 7,060 AFY currently and up to 7,840 AFY after 2015. These supplies
could meet the projected annual average demand through 2030. However, because
the supply from the SBWRP is limited to the agreement amounts at any time, there
may be supply deficits on a monthly basis and almost certainly on peak demand days.
Table 4-2 provides a summary of projected monthly recycled water demands based on
historical District seasonal and peak recycled water demand patterns reported in the
Otay Water District Water Resources Master Plan Update (revised November 2010).
The existing combined monthly recycled water supply from the RWCWRF and the
SBWRP is 588 AF (7,060 AF/12 months). This amount will increase to 653 AF (7,840
AF / 12 months) after 2015. Thus, on a monthly basis, the District will begin seeing
deficits by 2020 during the peak demand months. The peak month deficits are
projected to grow from approximately 670 AF in 2020 during the two peak demand
months, to 1,100 AF during the two peak demand months in 2035. In addition, the
deficits are expected to occur for over half the year by 2035.
May 2013 42
Wastewater
Management
Plan
Table 4-2. Projected Monthly Recycled Water Demands
Month
Demand
(% of Ann. Ave.)1
Projected Recycled Water Demand (AF)
2010 2015 2020 2025 2030 2035
Jan 3.50% 143 154 175 203 238 280
Feb 3.50% 143 154 175 203 238 280
Mar 2.33% 95 103 117 135 159 187
Apr 4.92% 200 216 246 285 334 393
May 7.67% 312 337 383 445 521 613
Jun 11.17% 455 491 558 648 759 893
Jul 12.00% 489 528 600 696 816 960
Aug 13.17% 536 579 6583 764 895 1,053
Sep 13.42% 547 590 671 778 912 1,073
Oct 10.75% 438 473 538 624 731 860
Nov 9.25% 377 407 463 537 629 740
Dec 8.33% 340 367 417 483 567 667
Ann. Ave.2 100.00% 4,074 4,400 5,000 5,800 6,800 8,000
Notes: 1. Source: 2010 Water Resources Master Plan Update (revised November 2010).
2. Source: 2010 Urban Water Management Plan (adopted June 1, 2011). 3. Highlighted numbers indicate months where demand will exceed the available
supply of 668 AF.
Table 4-3 summarizes the projected peak day recycled water demand versus existing
supply, based also on peak day demand usage reported in the 2010 Water Resources
Master Plan Update. The District is already seeing deficits in meeting peak day
recycled water demands and has had to supplement with potable water. The 2010
peak day deficit of 1.0 MGD is projected to increase to 7.3 MGD in 2035. The
projected monthly and peak day recycled water supply deficits would have to be
supplied from alternative sources. Potential additional recycled water supplies are
discussed in the next section.
May 2013 43
Wastewater
Management
Plan
Table 4-3. Projected Peak Day Recycled Water Demands vs. Existing Supply
Demand/Supply
Projected Recycled Water Demand
2010 2015 2020 2025 2030 2035
Ann. Ave. Demand (AFY)1 4,074 4,400 5,000 5,800 6,800 8,000
Ann. Ave. Demand (MGD) 3.64 3.93 4.46 5.18 6.07 7.14
Peak Day Demand (MGD)2 7.3 7.9 8.9 10.4 12.1 14.3
RCWRF Supply (MGD)3 1.0 1.0 1.0 1.0 1.0 1.0
SBWRP Maximum Supply (MGD) 5.3 6.0 6.0 6.0 6.0 6.0
Total Existing Supply (MGD) 6.3 7.0 7.0 7.0 7.0 7.0
Surplus/(Deficit) (MGD) (1.0) (0.9) (1.9) (3.4) (5.1) (7.3)
Notes: 1. Source: 2010 Urban Water Management Plan (adopted June 1, 2011).
2. Source: 2010 Water Resources Master Plan Update (revised November 2010). Peak day to annual average demand factor = 2.0.
3. Effective treatment capacity.
4.5 Potential Additional Recycled Water Supply Options
Previous planning efforts have identified additional recycled water supplies that may be
available to supplement existing and future District supplies. A brief summary of these
potential sources is presented below based on details provided in the Otay Water
District Integrated Water Resources Plan (March 2, 2007), the Otay Water District
2010 Urban Water Management Plan (adopted June 1, 2011), and the Otay Water
District Water Resources Master Plan Update (revised November 2010). The potential
additional supplies could come from the following sources:
• Expansion of the RWCWRF
• Additional purchases from the City of San Diego SBWRP
• Partnership with the City of Chula Vista on a regional WRF
• A new joint WRF with San Diego County
An additional option was identified early in the project that involved a new supply from
the International Boundary and Water Commission (IBWC) South Bay International
Wastewater Treatment Plant. This option would involve providing additional advanced
treatment facilities at the international plant as well as multiple international treaties and
agreements that would have to be implemented. It was determined that this option had
too many uncertainties compared to the other options and was not included in this
Wastewater Management Plan. Appendix A provides a planning level study of
additional advanced treatment at the IBWC plant.
May 2013 44
Wastewater
Management
Plan
4.5.1 Expansion of the RWCWRF
This option involves an expansion of the production capacity of the RWCWRF in order
to produce additional recycled water. The District indicated that this option could
include expanding the RWCWRF in 1.3 MGD increments up to an ultimate capacity of
3.9 MGD. The wastewater flow projections presented in Chapter 2.0 indicated that the
current wastewater flows from the District’s service area are approximately 1.84 MGD,
which would increase to approximately 2.15 MGD by 2030. Flow from the entire
Jamacha Basin is currently approximately 2.48 MGD, including customers not currently
connected to the sewer system, and is projected to increase to approximately 2.96
MGD in 2030. Thus, an expansion to 3.9 MGD would be a long-term option unless
additional wastewater flows could be transferred into the Jamacha Basin. Evaluation
of transferring such wastewater flows is not within the scope of this project. However,
the evaluations will consider an expansion of the RWCWRF to an ultimate capacity of
3.9 MGD. The costs for transferring wastewater into the Jamacha Basin are not
included in the evaluations, nor are the potential increased flow impacts on the existing
wastewater collection system. There exists a cost-sharing agreement from 1998 that
allocates capital and operating costs between the District and San Diego County.
Allocated costs are typically based on proportionate flow discharged by the two service
areas.
The total recycled water supply under the RWCWRF expansion options would be up to
2,600 AFY for an expansion to 2.6 MGD and 3,900 AFY for an expansion to 3.9 MGD,
based on a 90 percent production efficiency. Any additional sewer flows beyond the
RWCWRF treatment capacities would be bypassed to the Metro System facilities.
The infrastructure required for this option would include expansion of plant facilities,
including addition of a dedicated chlorine contact basin to achieve the Title 22 contact
time requirements before reuse that is currently provided in the 14-inch recycled water
pipeline. The flow velocity in a 14-inch steel pipeline flowing at 3,500 gpm (the current
capacity of the recycled water pump station) is approximately 7.5 feet per second (fps).
The flow velocity at the RWCWRF capacity of 3.9 MGD (2,730 gpm) is approximately
5.5 fps. Assuming continued structural integrity of the 14-inch pipeline over an
assumed pipeline life of 50 years, the range of velocities at the proposed RWCWRF
expansions of 2.6 and 3.9 MGD should be acceptable operationally. New
infrastructure could also include sludge treatment and disposal facilities located at the
plant. The total cost for this option would include capital costs for all new infrastructure
and the additional operations and maintenance (O&M) costs associated with the
additional yield of recycled water supply.
May 2013 45
Wastewater
Management
Plan
4.5.2 Additional Purchases from the SBWRP
Under this option, the District could currently acquire an additional supply of up to 4
mgd (4,500 AFY) of SBWRP recycled water (for a total of 10 MGD). The City of San
Diego is providing the District with transmission capacity in a 30-inch transmission
system to deliver recycled water from the point of delivery to the District service area
which is 4,100 feet from the SBWRP. The capacity of this transmission system to
accept the additional flows would have to be verified. The District is responsible for the
construction of conveyance infrastructure from the City’s pipeline to the District’s 450
Zone Reservoirs. The capacity of this conveyance structure to accept the additional
flows would also have to be verified. No other infrastructure would be required for the
additional purchase of recycled water from SBWRP. Annual purchase and operation
costs would also exist, which would most likely be equivalent to costs incurred for the
existing agreement on a per unit basis.
This option would require coordination with the City of San Diego to amend the current
agreement allowing the additional purchases.
4.5.3 Partnership with City Of Chula Vista
This option involves a partnership whereby a new proposed WRF would be owned by
the City of Chula Vista, and the District would only purchase recycled water but not be
responsible for the construction or operation of the treatment plant. Recycled water
from this plant would be delivered to serve the District’s Central Area System recycled
water demands.
The City of Chula Vista and the District completed a study in 2012 (Acquisition of
Additional Wastewater Capacity Project, Final Report, April 2012) that, in addition to
comparing the purchase of additional wastewater treatment capacity in the Metro
System for Chula Vista purposes, investigated the potential partnership to provide an
additional supply of Title 22 recycled water to the District. The City of San Diego
received its third modified permit, or waiver, for the Point Loma WWTP in June 2010
from the California Coastal Commission for meeting federal standards for secondary
treatment of sewage, extending the permit for ocean disposal of advanced primary
treated wastewater until 2015. The permit will be reevaluated in 2015 by the Coastal
Commission, and it is uncertain whether an upgrade to secondary treatment will be
required at that time. The costs of purchasing capacity in the Metro System will
substantially increase should an upgrade to full secondary treatment at the Point Loma
WWTP be required.
May 2013 46
Wastewater
Management
Plan
The basic concepts for the potential District/Chula Vista partnership included the
following:
• The majority of recycled water produced by the Chula Vista plant can be
used by the District; however, the District would have to make the Chula
Vista recycled water a second priority behind RWCWRF recycled water and
before recycled water purchased from the SBWRP. It is anticipated that the
District could take most of the recycled water produced during the peak
summer demand months but would take essentially no water during low
demand months. Thus, Chula Vista would have to make arrangements for
disposal of unused recycled water, most likely through an agreement with
the IBWC, to use their ocean outfall for the South Bay International
Wastewater Treatment Plant.
• The RWCWRF would continue to produce recycled water at current levels a
minimum of 8 months of the year for the duration of the study period (i.e., no
expansions).
• Recycled water would be sold to the District at a rate of $350 per AF.
• The Chula Vista plant would be built in three phases of 2 MGD increments:
2 MGD, 4 MGD, and 6 MGD to match Chula Vista population and growth.
• The plant would utilize modern technologies, such as a membrane bioreactor
(MBR), to provide a high level of treatment efficiency on a small site.
• The preferred site for the MBR plant is near the Salt Creek Interceptor
between I-805 and I-5 in the southwestern portion of the District’s water
service area, about 3 miles north of the SBWRP.
Infrastructure required for this option would include a pump station and a transmission
pipeline to convey recycled water from the Chula Vista plant to the District’s Central
Area System. This option would also require coordination with the City of Chula Vista,
the City of San Diego, and the County of San Diego.
The decision to build a new regional plant versus continuing to discharge wastewater
to the Metro System will depend on whether the Metro System Point Loma WWTP will
need to be upgraded to secondary treatment, a decision that will be reevaluated in
2015. Chula Vista anticipates needing additional wastewater treatment capacity within
the next 14 to 19 years, but with the looming Point Loma WWTP decision and with
permitting, design and construction anticipated to take 5 to 10 years, the City will have
to make a decision regarding project implementation soon.
May 2013 47
Wastewater
Management
Plan
4.5.4 Joint WRF with San Diego County
The District and County have conducted previous studies related to joint water
reclamation facilities (Metcalf & Eddy, 1997). The efforts have identified a preferred
location near the I-805 and the Sweetwater River. This location is downstream of the
RWCWRF, which would allow collection of additional wastewater flows. The proposed
capacity of the joint District/County facility is 10 MGD. There are many uncertainties
and concerns associated with the preferred location, such as the ability to obtain a
discharge permit to the Sweetwater River. This option has not been studied further,
thus, at the direction of the District, the evaluations herein, including treatment facility
concepts and costs, are assumed to be similar to the Chula Vista option.
May 2013 48
Wastewater
Management
Plan
5.0 ANALYSIS OF WASTEWATER MANAGEMENT OPTIONS
This chapter summarizes the analysis of potential future wastewater treatment,
disposal, and reuse options for the District by comparing capital and operational costs
over the 20-year planning horizon to 2030. The objective of the comparison is to
recommend a wastewater treatment, disposal, and recycling plan to the District based
on updated planning and cost estimates for local and regional wastewater
management elements potentially affecting future costs to the District wastewater and
recycled water customers. Appendix D provides detailed discussion and cost
estimates for the wastewater management options.
5.1 Identification of Wastewater Management Options
Wastewater management options were identified, reviewed and discussed in multiple
workshops with District staff. From these discussions, wastewater management
options were defined and synthesized into five major feasible alternatives involving
wastewater treatment, disposal, and reclamation. The five wastewater management
options selected for evaluation are listed below:
• Option A: Maintain RWCWRF at 1.3 MGD
• Option B: Expand RWCWRF to 2.6 MGD
• Option C: Expand RWCWRF to 3.9 MGD
• Option D: Abandon RWCWRF and Utilize Metro
• Option E: Abandon RWCWRF and Utilize New Joint District/County WRF
All options presume continued ownership, operation, maintenance, and required
expansion of the District's existing wastewater collection system consistent with the
wastewater flow projections, hydraulic modeling analyses, and capital improvement
projects discussed in Chapter 3 of this report. All options also assume that the required
improvements to the Rancho San Diego Pump Station will be implemented. Finally, all
options assume that the disinfection facilities at the RWCWRF will be upgraded such
that all disinfection contact time and dosage required are achieved at the plant.
Within the wastewater management options, there are also alternatives for wastewater
sludge handling (onsite and continued discharge to Metro), sources of reclaimed water
(described in Chapter 4), and future Metro wastewater treatment. The Metro
wastewater treatment alternatives include 1) continued advanced primary treatment at
the Point Loma WWTP and assumed continuance of an existing waiver from the
Environmental Protection Agency, and 2) upgrade of the Point Loma WWTP to
secondary treatment with attendant costs and allocation of the District's fair share of
May 2013 49
Wastewater
Management
Plan
the future capital and operating costs. In a recent Recycled Water Study performed for
the City of San Diego and released on May 10, 2012, alternatives to the Point Loma
Upgrade were evaluated. Alternatives include diversion of wastewater from Point
Loma, increased recycled water use, and Indirect Potable Reuse (IPR) using the San
Vicente reservoir and Otay Lakes. Multiple alternatives are presented with projected
capital and operating costs. The selected IPR alternative could result in a reduction in
costs from the secondary upgrade costs allocated to the District for those wastewater
management options which include continued discharge to the Metro System.
Although it is presumed that San Diego and its participating agencies will select the
most cost-effective long-term wastewater and recycled water management solution
approvable by EPA, this Wastewater Management Plan uses the assumption of
upgrade to secondary treatment for Point Loma.
5.1.1 Option A: Maintain RWCWRF at 1.3 MGD
This wastewater management option maintains the status quo at the RWCWRF, with
the exception of water quality enhancements and potential solids handling facilities at
the treatment plant location. The capacity of the RWCWRF will remain at the existing
1.3 MGD. All flows conveyed via the District's wastewater collection system in excess
of 1.3 MGD will be discharged to the San Diego Metro wastewater collection and
treatment system with the associated institutional and financial impacts. The evaluation
of Option A includes the following sub-options:
Wastewater Solids Handling
• Onsite treatment at RWCWRF
• Continued discharge to the Metro system
Future San Diego Metro Treatment
• Continued primary treatment
• Upgrade to secondary treatment
Recycled Water Sources
• RWCWRF
• SBWRP
• Chula Vista WRF
May 2013 50
Wastewater
Management
Plan
Figure 5.1 below depicts the conceptual flow, treatment, wastewater discharge, and
recycled water use schematic for Option A. Note that the options for recycled water
sources are not indicated on the diagram, but are included in the evaluations.
Figure 5.1 Option A: Maintain RWCWRF at 1.3 MGD
5.1.2 Option B: Expand RWCWRF to 2.6 MGD
Option B includes the expansion of the RWCWRF from 1.3 MGD to 2.6 MGD
consistent with the flow projections discussed in Chapter 2. Flows in excess of 2.6
MGD will be conveyed to the Metro system. The evaluation of Option B includes the
following sub-options:
Wastewater Solids Handling
• Onsite treatment at RWCWRF
• Continued discharge to the Metro system
Future San Diego Metro Treatment
• Continued primary treatment
• Upgrade to secondary treatment
May 2013 51
Wastewater
Management
Plan
Recycled Water Sources
• RWCWRF
• SBWRP
Purchase of recycled water from a future Chula Vista MBR water reclamation plant is
not included in Option B since the engineering feasibility studies for the Chula Vista
facility were based on the RWCWRP remaining at its current 1.3 MGD capacity. Figure
5.2 below shows the conceptual wastewater flow and discharge diagram for Option B.
Note that the recycled water purchase from SBWRP is not shown, but is included in
the evaluations.
Figure 5.2 Option B: Expand RWCWRF to 2.6 MGD
5.1.3 Option C: Expand RWCWRF to 3.9 MGD
Option C includes the expansion of the RWCWRF from 1.3 MGD to 3.9 MGD. It is
recognized that the Jamacha Basin wastewater flow projections developed in Chapter
2 do not indicate the need for a 3.9 MGD treatment capacity at the RWCWRF.
However, the District decided to maintain the incremental modularity of the treatment
plant capacity and assume an expansion module of 2.6 MGD consistent with Option B.
Flows in excess of those treated by RWCWRF will be conveyed to the Metro System.
Flows anticipated to be treated by Metro are anticipated to be minimal only, conveyed
May 2013 52
Wastewater
Management
Plan
at times of RWCWRF plant maintenance or emergency interruptions. The evaluation of
Option C includes the following sub-options:
Wastewater Solids Handling
• Onsite treatment at RWCWRF
• Continued discharge to the Metro system
Future San Diego Metro Treatment
• Continued primary treatment
• Upgrade to secondary treatment
Recycled Water Sources
• RWCWRF
• SBWRP
For the same reason as Option B, purchase of recycled water from a future Chula
Vista MBR water reclamation plant is not included in Option C. Figure 5.3 below shows
the conceptual wastewater flow and discharge diagram for Option C. Note that the
recycled water purchase from SBWRP is not shown, but is included in the evaluations.
Figure 5.3 Option C: Expand RWCWRF to 3.9 MGD
May 2013 53
Wastewater
Management
Plan
5.1.4 Option D: Abandon RWCWRF and Utilize Metro
Option D includes the decommissioning and demolition of the RWCWRF. All
wastewater collected in the Jamacha Basin will be sent to the Point Loma WWTP
through the Rancho San Diego Pump Station. The evaluation of Option D includes the
following sub-options:
Future San Diego Metro Treatment
• Continued primary treatment
• Upgrade to secondary treatment
Recycled Water Sources
• SBWRP
• Chula Vista WRF
Figure 5.4 below shows the conceptual wastewater flow and discharge diagram for
Option D. Note that the recycled water purchases from the SBWRP and Chula Vista
WRF are not shown, but are included in the evaluations.
Figure 5.4 Option D: Abandon RWCWRF and Utilize Metro
5.1.5 Option E: Abandon RWCWRF and Utilize New Joint District/County WRF
Option E includes the decommissioning and demolition of the RWCWRF. Wastewater
collected in the Jamacha Basin will be sent to a new proposed joint wastewater
treatment and recycling facility with San Diego County or the Point Loma WWTP
through the Rancho San Diego Pump Station. Collection system modifications and
extensions will be required to convey existing flow to the new joint WWTP and to by-
May 2013 54
Wastewater
Management
Plan
pass to the Metro System, as required. Solids treatment at the new joint plant is
assumed, since the plant process is assumed to be the same as the Chula Vista MBR
plant. The conceptual joint new WWTP has been described in the 1997 report by
Metcalf and Eddy for San Diego County entitled “Water Reclamation Facility Project
Feasibility Report”. The concept included a 10 MGD plant located near I-805 and the
Sweetwater River, using an activated sludge aeration process. This Wastewater
Management Plan assumes an MBR plant similar to the Chula Vista proposal with cost
estimates the same as the Chula Vista plant for equivalent capacity. The evaluation of
Option E includes the following sub-options:
Future San Diego Metro Treatment
• Continued primary treatment
• Upgrade to secondary treatment
Recycled Water Sources
• Joint District/County WRF
• SBWRP
Purchase of recycled water from the Chula Vista WRF is not included in this option,
because it is assumed that the new joint WRF will be sized to provide as much
recycled water as the Chula Vista WRF would. Figure 5.5 below shows the conceptual
wastewater flow and discharge diagram for Option E. Note that the recycled water
purchases from the SBWRP and Chula Vista WRF are not shown, but are included in
the evaluations.
May 2013 55
Wastewater
Management
Plan
Figure 5.5 Option E: Abandon RWCWRF and Utilize New Joint District/County
WRF
5.2 Summary of Cost Components for Wastewater Management Options
The cost components applicable to each wastewater management option included
wastewater treatment components and recycled water components. Table 5-1
summarizes the wastewater treatment cost elements applicable to each option.
Table 5-1. Wastewater Treatment Cost Components
Cost Component Option
A B C D E
RWCWRF
Expansion ● ●
On-Site Solids Handling ● ● ●
Decommissioning ● ●
Metro System Capacity
Existing Charge (w/o on-site solids handling) ● ● ● ●
New Capacity Charge (w/o on-site solids handling) ● ● ●
Point Loma WWTP Upgrade (w/o on-site solids handling) ● ● ● ●
New County/Otay WWTP ●
May 2013 56
Wastewater
Management
Plan
Table 5-2 indicates the recycled water sources which exist for each of the wastewater
management options. For facilities other than the RWCWRF, cost elements allocated
for recycled water include costs to purchase each unit of recycled water and costs for
new booster stations and pipelines to deliver water from the facilities to the District's
recycled water distribution system.
Table 5-2. Recycled Water Sources for Wastewater Management Options
Recycled Water Source Option
A B C D E
RWCWRF ● ● ●
SBWRP ● ● ● ● ●
New Chula Vista WRF ● ●
New County/District WWTP ●
In consideration of the key variables for evaluating capital and annual O&M costs for
the wastewater management options, sub-options have been identified to compare
present worth costs. Sub-options are combinations of wastewater treatment, disposal,
and recycled water purchase variables. Table 5-3 presents the matrix of options and
sub-options that are evaluated.
Table 5-3. Matrix of Wastewater Management Sub-Options Evaluated
Wastewater Management Option
Recycled Water from SBWRP
Only, No Chula Vista Purchases
No SBWRP Purchases, Recycled
Water from Chula Vista WRF Only
No Point Loma WWTP Upgrade
Point Loma WWTP Upgrade
No Point Loma WWTP Upgrade
Point Loma WWTP Upgrade
A Onsite sludge A-2 -- A-1 --
No onsite sludge A-6 A-4 A-5 A-3
B Onsite sludge B-1 -- -- --
No onsite sludge B-3 B-2 -- --
C Onsite sludge C-1 -- -- --
No onsite sludge C-3 C-2 -- --
D D-4 D-3 D-2 D-1
E (onsite sludge) E-2 E-1
May 2013 57
Wastewater
Management
Plan
5.3 Cost Estimates for Expansion and Demolition of the RWCWRF
The wastewater management options include expansion or decommissioning of the
RWCWRF. Detailed construction cost estimates have been prepared associated with
upgrading, expanding, and decommissioning the RWCWRF. Appendix B provides a
site map of the RWCWRF with suggested locations for new processes and expansions
for Options A, B and C. Appendix C provides a report detailing cost estimates for the
RWCWRF expansions and demolition alternatives.
In addition to the assumed expansions, Options B and C include addition of a larger
chlorine contact chamber to achieve CA Title 22 requirements for contact time at the
plant site. Options A through C also consider potential addition of solids handling
facilities. Options D and E include decommissioning of the RWCWRF and restoring
the site.
5.3.1 Estimated Construction Costs for RWCWRF Options
A summary of opinions of capital costs for the three options that involve continued use
and/or expansion of the RWCWRF is presented in Table 5-4. Table 5-4 includes onsite
solids handling costs which are removed when evaluating wastewater management
options that do not include onsite solids handling.
5.3.2 Estimated Additional O&M Costs for RWCWRF Options
In addition to capital cost estimates for the RWCWRF components of Options A
through C, specific elements of annual O&M costs have been estimated for the three
options. Key elements of the operational costs include additional power and chemical
costs. Additional power costs were based on a blended rate of $0.12 per KWH. Table
5-5 summarizes the estimated additional O&M costs.
Similar to estimated construction costs, Table 5-5 includes onsite solids handling O&M
costs which are removed when evaluating wastewater management options that do
not include onsite solids handling.
May 2013 58
Wastewater
Management
Plan
Table 5-4. Opinions of Construction Costs for RWCWRF Options
Treatment Process
Estimated Construction Costs ($)
Option A:
Maintain RWCWRF at
1.3 MGD
Option B:
Expand RWCWRF to
2.6 MGD
Option C:
Expand RWCWRF to
3.9 MGD
Influent Pump Station 0 1,130,000 1,290,000
Headworks & Grit Removal 0 2,040,000 2,200,000
Aeration Basins 0 3,330,000 5,900,000
Secondary Clarifiers 0 1,960,000 3,580,000
RAS/WAS Pump Station 0 820,000 1,490,000
Scum Pump Station 0 173,000 173,000
Effluent Pump Station 0 788,000 1,540,000
Administration Building 0 0 1,040,000
Blower & Electrical Building 0 2,050,000 2,490,000
Aerobic Digestion 1,460,000 2,760,000 3,940,000
Digested Sludge Pump St. 121,000 229,000 331,000
WAS Thickening 848,000 1,580,000 2,310,000
Sludge Dewatering Centrifuge 915,000 915,000 1,750,000
Tertiary Filters (+Flocculation) 0 648,000 1,300,000
NaOCl Storage, Pumping and
Chlorine Contact Tank
0
2,010,000
2,200,000
Totals $3,350,000 $20,500,000 $31,500,000
Table 5-5. Opinions of Additional O&M Costs for RWCWRF Options
Annual O&M Component
Estimated Additional O&M Costs ($/year) Option A: Maintain RWCWRF at 1.3 MGD
Option B: Expand RWCWRF to 2.6 MGD
Option C: Expand RWCWRF to 3.9 MGD
Additional KWHs 468,000 4,850,000 10,600,000
Additional Power Cost 56,200 581,000 1,280,000
DAF Polymer Cost 10,000 19,900 29,900
Solid Dewatering (Polymer) Cost 32,400 64,800 97,200
Sodium Hypochlorite Cost 0 31,000 77,100
Totals $98,600 $697,000 $1,480,000
May 2013 59
Wastewater
Management
Plan
5.3.3 Estimated Decommissioning Costs for RWCWRF Options
The report in Appendix C also includes the estimated costs to decommission the
RWCWRF and the Steel Bridge Pump Station, which pumps raw wastewater to the
RWCWRF. Costs were estimated for decommissioning the plant and pump station,
and for demolition of facilities and restoration of the plant site. These costs are
associated with wastewater management Option D and Option E. The estimated costs
are as follows:
• Decommissioning: $492,000
• Demolition and restoration: $3,460,000
• Total: $3,960,000 (rounded)
5.4 Summary of Wastewater Management Options Cost Evaluations
Based on the wastewater flow projections presented in Chapter 2 and the recycled
water use projections presented in Chapter 4, a major objective of this wastewater
management plan is to compare projected capital and operating costs for the five
wastewater management options to develop a recommended District course of action
for the future. The comparative cost approach was estimates of present worth costs,
using the sum of capital costs in 2012 dollars and today’s value of annual O&M costs
from 2015 through 2030 (16 years).
5.4.1 Common Economic Cost Assumptions
A common set of assumptions was developed for all five options. The assumptions
include considerations for both wastewater discharge and recycled water purchases.
The list of assumptions is presented in Table 5-6. In addition to the assumed cost
factors, the projected value of money was assumed to be increasing at 2 percent per
year for determining the present worth of operating and maintenance expense.
May 2013 60
Wastewater
Management
Plan
Table 5-6. Common Economic Cost Assumptions
SBWRF, Chula Vista, Joint Plant Recycled Water Purchase Rate (per AF)1 $350
2012 Metro County Wastewater Discharge Rate (per MGD)2,6 $3,089,634
Additional Metro Capacity Cost (per MGD)3 $30,000,000
PLWWTP Upgrade Capital Cost4 $1,161,174,957
Otay WD Capital Cost for PLWWTP Upgrade (0.513%)4 $5,956,828
PLWWTP Upgrade O&M Cost4 $37,497,060
Otay WD Annual O&M Cost for PLWWTP Upgrade (per MGD)4 $156,238
MWD/SDCWA Rebate (per AF)5 $385
1. Based on Recycled Purchase Agreement between City of San Diego and Otay WD.
2. Based on Metro Discharge Agreement between City of San Diego and Otay WD.
3. $22 Million paid to Metro, $8 Million paid to the County. A one-time up-front cost for buying capacity in these systems.
4. Point Loma WWTP Secondary Treatment Upgrade Costs at Different Capacities from The City of San Diego's Wastewater
Master Plan and Recycled Water Study, May 2012
5. $185/AF is received from MWD; $200/AF comes from the SDCWA.
6. Lump sum of Metro Cost and County cost based on recent District invoices.
5.4.2 Summary of Cost Comparisons for Wastewater Management Options
Appendix D provides the details of the cost evaluation for the wastewater management
options. For all options, wastewater discharge costs are based on projected
wastewater discharge rates, facilities used, and facility and contract costs through
2030. For all options, recycled water purchase costs are based on projected recycled
water needs, production sources, production amounts, and facility and contract costs
through 2030. The bases for costs for each of the sub-options summarized in Table 5-
3 are evaluated separately as (1) wastewater discharge amounts and costs and (2)
recycled water use amounts and costs. Wastewater discharge and recycled water use
volumes are indicated for five-year planning horizons from 2010 (actual) through 2030,
consistent with District projections indicated previously.
A summary of estimated present worth costs for the wastewater management options
is presented in Table 5-7.
May 2013 61
Wastewater
Management
Plan
Table 5-7. Present Worth Cost Summary for Wastewater Management Options
Wastewater Management
Option
Sludge
Handling
Option
Estimated Present Worth ($ millions)
SBWRP Purchases
Only, No Chula Vista
Purchases
No SBWRP
Purchases, Chula
Vista Purchases Only
No Point
Loma
WWTP
Upgrade
Point
Loma
WWTP
Upgrade
No Point
Loma
WWTP
Upgrade
Point
Loma
WWTP
Upgrade
A
Onsite sludge $37.1 -- $34.7 --
No onsite
sludge $79.3 $87.0 $77.0 $84.6
B
Onsite sludge $82.7 -- -- --
No onsite
sludge $86.4 $92.8 -- --
C
Onsite sludge $134.3 -- -- --
No onsite
sludge $139.8 $146.3 -- --
D NA $153.7 $163.0 $156.8 $166.1
E Onsite Sludge $148.0 $154.0 -- --
The cost evaluation of wastewater management options results in the following key
conclusions:
• The present worth costs for Option A are significantly less for on-site solids
handling at RWCWRF due to presumed avoidance of significant discharge to
Metro and future Point Loma upgrade costs, or its Metro alternative.
• For Options A, B and C, the lowest present worth costs are for retaining the
RWCWRF at 1.3 MGD capacity and not expanding.
• Options D and E are significantly more costly due to increased discharge to
Metro, with risks of incurring costs for Point Loma upgrade, and cost of a
new joint WWTP in partnership with the County.
May 2013 62
Wastewater
Management
Plan
6.0 CONCLUSIONS AND RECOMMENDATIONS
6.1 Summary of Conclusions
The work conducted in this Wastewater Management Plan yields the following
significant conclusions:
Wastewater Flow Projections
• The total Jamacha Basin wastewater flows from connected and unconnected
properties are projected to increase from 2.48 MGD in 2010 to 2.96 MGD in
2030.
• Wastewater flows from the District’s service area within the Jamacha Basin,
from connected and unconnected properties, are projected to increase from
1.84 MGD in 2010 to 2.15 MGD in 2030
• Wastewater flows from the County’s service area within the Jamacha Basin,
from connected and unconnected properties, are projected to increase from
0.64 MGD in 2010 to 0.81 MGD in 2030.
Wastewater Collection System
• The existing wastewater collection system has only three areas that do not
meet system performance criteria under existing peak wastewater flow
conditions. These problem areas should be corrected by replacing the
existing undersized sewer pipes.
• One of the existing problem areas is along Campo Road in a section of 10-
inch sewer pipe that was, in the past, converted from a forcemain to a gravity
pipe. The former forcemain pipe is undersized to act adequately as a gravity
pipe. The District would like to replace the entire section of former forcemain
pipe with a 15-inch gravity pipe.
• The existing wastewater collection system has only two additional areas that
do not meet system performance criteria under 2030 peak flow conditions.
The undersized sewer pipes in these areas should also be replaced as funds
become available.
Recycled Water Supply and Demand
• The District’s existing recycled water supply is an average 1.0 MGD from the
RWCWRF and up to 6 MGD annually from the City of San Diego’s SBWRP.
Due to problems with wastewater supply, other large demands taking
priority, etc., the actual peak availability of recycled water from the SBWRP
May 2013 63
Wastewater
Management
Plan
has recently been only 5.3 MGD. The problems with District recycled water
supply are anticipated to be corrected by San Diego by 2015.
• The District projects that its recycled water demand will increase from 4,074
AFY in 2010 to 8,000 AFY in 2035.
• On a monthly basis, the District will begin seeing deficits in recycled water
supply by 2020 during the peak demand months. The peak month deficits
are projected to grow from approximately 670 AF in 2020 during the two
peak demand months, to 1,100 AF during the two peak demand months in
2035. In addition, the deficits are expected to occur for over half the year by
2035. These deficits are not annual and can be mitigated if the
District/SBWRP agreement can be amended to allow the District to take its
contracted amount at up to two times its annual average rate.
• The District is already seeing supply deficits in meeting peak day recycled
water demands and has had to occasionally supplement with potable water.
The peak day supply deficit is projected to grow from approximately 1.0
MGD in 2010 to 7.3 MGD in 2035. The deficits can be managed with
appropriate recycled water system storage and a modification to the
District/SBWRP agreement, as described above.
• Potential additional supplies of recycled water evaluated include the
following sources:
o Expansion of the RWCWRF
o Additional purchases from the City of San Diego SBWRP
o Purchase of recycled water from a potential new City of Chula Vista
regional WRF
o A new joint WRF with San Diego County
Future Wastewater and Recycled Water Management Options
• There exist multiple economic, institutional, regulatory, and environmental
factors which are currently affecting and will affect the District’s future
options for treating, reusing, and discharging wastewater generated within
the District’s limited wastewater service area.
• Wastewater treatment options include the RWCWRF, discharge to the Metro
System, and partnership with the County in a conceptual new 10 MGD plant.
• Recycled water supply options include the RWCWRF, the Metro SBWRP, a
potential new 6 MGD WRF in Chula Vista, and a potential new joint
treatment and reclamation plant in partnership with the County.
• The wastewater management and recycled water options were combined
into five overall management options for cost evaluations:
o Option A – maintain RWCWRF at 1.3 MGD
May 2013 64
Wastewater
Management
Plan
o Option B – expand RWCWRF to 2.6 MGD
o Option C – expand RWCWRF to 3.9 MGD
o Option D – decommission RWCWRF and send all flow to Metro
o Option E – decommission RWCWRF and build joint plant with County
• The evaluation of RWCWRF options considered onsite solids handling/
sludge management and no onsite sludge management. The joint County
plant options considered only onsite sludge management consistent will all
previous planning efforts. All options that involved discharge of any flows to
the Metro System included consideration of the Metro Point Loma WWTP
remaining a primary treatment plant and upgrade to a secondary treatment
plant with associated capital and O&M cost impacts to the District.
• A detailed present worth cost evaluation of the five primary management
options and many sub-options, that included estimates of capital costs,
annual O&M costs, and recycled water purchases through 2030 lead to the
following conclusions:
o Option A (RWCWRF stays at 1.3 MGD) has the lowest present worth
costs of the five options, followed by Option B (expand RWCWRF to 2.6
MGD), then Option C (expand RWCWRF to 3.9 MGD). This is due to the
existing investment in RWCWRF and the avoidance of Metro discharge
costs and additional recycled water purchase costs.
o Option D (send all flow to Metro System) has the highest present worth
cost due to the existing cost structure, potential for upgrade costs
associate with Point Loma, and need to purchase additional Metro and
County system capacity.
o The lowest cost sub-options involve onsite solids handling, purchase of
recycled water from a Chula Vista WRF, and avoidance of payment for a
Metro Point Loma WWTP upgrade.
o For all RWCWRF expansion options (A, B, and C), construction and
operation of onsite solids handling is more cost-effective than no onsite
solids handling due to the reduced Metro discharge volumes and costs.
o Abandonment of RWCWRF and reliance on Metro or a new joint
District/County WRF is significantly more costly than retaining RWCWRF
at any of the three capacities evaluated. This reinforces the District’s
value in the existing plant and in its Metro and County system capacity
ownership.
o Purchase of recycled water from a new Chula Vista WRF appears to be
more cost-effective than purchase from the SBWRP due to the current
take or pay provision in the SBWRP agreement.
May 2013 65
Wastewater
Management
Plan
6.2 Wastewater Collection System Recommendations
6.2.1 Hydraulic Model
The existing hydraulic model was last calibrated in 2006 and should be recalibrated in
the next planning effort. Typically, a hydraulic model is calibrated every 5 years as
changes in development occur, or as happened in the current planning effort, several
of the modeled system components (pump stations and pipelines) were updated. The
District should also consider calibrating the model using predictive hydrologic methods
in the next model update. In terms of versatility and range of applications, it far
exceeds the capabilities of the peaking factor methodology which is currently utilized.
6.2.2 Recommended Wastewater System Improvements
Table 6-1 summarizes the schedule and capital cost opinions for the recommended
wastewater collection system improvements. Figures 3-4 and 3-6 illustrated the
recommended improvements. The estimated total capital cost for the recommended
infrastructure to correct existing system deficiencies is $8.53 million. To accommodate
2030 wastewater flows, the additional capital cost is approximately $2.72 million.
Table 6-1. Recommended Wastewater Collection System Improvements
Project No. Description Location
Unit Cost ($/LF)1
Conceptual Cost Opinion ($)
Existing 2030
Collection System Pipes
CIP #1 12-inch 36 LF Near Fury Ln and Jamacha Rd 1,020 $37,000 --
CIP #2 24-inch 91 LF Near Hillsdale Rd and Jamacha Rd 2,040 $190,000 --
CIP #3 15-inch 9,225 LF Along Campo Road from Avocado Rd to Singer Lane 900 $8,300,000 --
CIP #4 15-inch 900 LF Near Jamacha Rd and Donahue Dr 1,275 -- $1,150,000
CIP #5 15-inch 1,235 LF Along Ivanhoe Ranch Rd upstream of Cottonwood Pump Station 1,275 -- $1,570,000
Total $8,527,000 $2,720,000
Note: 1. January 2012 Costs (ENR CCI = 9176). Includes 30% for engineering and administration, 10% for contractor bonding and insurance, and 30% for project contingencies.
CIP #3 involves replacement of a former 10-inch forcemain that currently acts as a
gravity pipe. Portions of the pipe undersized for gravity flow. The District desires to
replace the entire stretch of this pipe with a new 15-inch gravity sewer pipe. The
alignment is primarily along Campo Road which is a major highway. Figure 6-1 shows
conditions along the pipeline alignment. A cursory site inspection revealed the
following potential problem areas that should be addressed during preliminary design:
May 2013 66
Wastewater
Management
Plan
• Intersection of Campo Road and Via Mercado.
• Intersection of Campo Road and Jamacha Boulevard, where Jamacha
Boulevard joins Campo Road from the south.
• Intersection of Campo Road and Jamacha Boulevard, where Campo Road
turns south.
May 2013 67
Wastewater
Management
Plan
Figure 6-1 Alignment for CIP #3
Figure 6-1. Alignment for CIP #3
May 2013 68
Wastewater
Management
Plan
6.3 Recommended Wastewater Management and Recycled Water Strategies
From the economic evaluations of the five wastewater (and recycled water)
management options, the following are recommended strategies for consideration by
the District.
• Retain and maintain the RWCWRF at its current capacity. This
recommendation, however, does not preclude a future expansion of
RWCWRF capacity if additional reclaimed water for the District cannot be
obtained from a new assumed Chula Vista WRF or from the SBWRP.
• If regulatory restrictions prohibit the use of the existing reclaimed water
pipeline to achieve required chlorine contact times before expansion of the
RWCWRP, then plan, design, and construct a chlorine contact chamber. The
estimated capital costs for the chlorine contact chamber is $3,420,000
(includes 30 percent for engineering and administration, 10 percent for
contractor bonding and insurance, and 30 percent for project contingencies).
• Plan, design, and construct on-site solids handling facilities on the RWCWRF
site for a capacity of 1.3 MGD expandable to 2.6 MGD. The estimated capital
costs for the on-site solids handling facilities is $5,690,000 (includes 30
percent for engineering and administration, 10 percent for contractor bonding
and insurance, and 30 percent for project contingencies).
• Target the on-site solids handling start-up date as early as possible, but no
later than 2015, to avoid potential Point Loma WWTP upgrade costs.
• Confirm that construction and operation of on-site solids handling facilities
will preclude significant discharges to the Metro System, except for plant
maintenance or emergency events.
• Upon construction of RWCWRF on-site solids handling, re-determine new
quality and resulting unit costs for Metro discharges.
• Renegotiate the SBWRP recycled water purchase agreement to allow short-
term, peak month and peak-day purchases of recycled water in excess of the
6 MGD limit stated in the contract, preferably to achieve 12 MGD. Also,
renegotiate the agreement to remove the take or pay provision.
• If the take or pay provision of the SBWRP agreement cannot be negotiated
out, support the future planning, design, permitting, and construction of the
Chula Vista WRF and negotiate a contract to take all recycled water
produced by the plant.
• Perform a District recycled water storage evaluation to assess daily and
peak month water balances to assure that projected peak period recycled
water demands can be achieved by the combination of RWCWRF,
SBWRP/Chula Vista WRP recycled water purchases with no or little
supplementation by other water sources, such as SDCWA water.
May 2013 69
Wastewater
Management
Plan
6.4 Potential Funding Sources for Wastewater Capital Improvements
This Wastewater Management Plan has recommended capital improvement projects
for the District’s wastewater collection system and the RWCWRF. There are available
options for funding these improvements through internal and external sources having
benefits and conditions requiring additional assessment by the District related to each
individual project.
6.4.1 Internal Funding Options
Internal funding options include conventional sources familiar to the District. These
include wastewater rates and connection fees that would fund debt service on revenue
bonds that the District would authorize and sell for specific projects. Since the District
typically funds projects in this manner, no more discussion is provided herein.
6.4.2 External Funding Options
External funding for the District’s proposed wastewater collection and treatment
projects could come from a number of public sources. The following discussion is a
summary of those potential sources.
Federal Funding
Federal funding for wastewater projects providing for wastewater reuse in lieu of use of
potable supplies has been included in the budget of the U.S. Bureau of Reclamation
(Bureau). Title II of the Senate version of the Fiscal Year 2013 (FY2013) Energy and
Water Development Appropriations Bill calls for $1B in funding for the Bureau, which is
$19.8M less than the FY2012 enacted amount. The House Energy and Water
Development Appropriations Bill recommends $967M for the Bureau, which is
approximately $81M below the House appropriation in FY2012.
The Water and Related Resources account of Title II supports the development,
construction, management, and restoration of water and related natural resources in
the 17 western states. The account includes funds for operating and maintaining
existing facilities and conducting studies on ways to improve the use of water and
related natural resources. Wastewater reuse projects can be potentially funded under
the TITLE XVI Water Reclamation and Reuse Program. A Title XVI Water Reclamation
and Reuse Program funding opportunity has been previously available through
WaterSMART. The Bureau invites sponsors of congressionally authorized Title XVI
May 2013 70
Wastewater
Management
Plan
projects to request cost-shared funding for the planning, design, or construction of
those proposed wastewater reuse projects. This funding opportunity is available by
searching funding opportunity number R13SF80002 on www.grants.gov.
The Bureau anticipates providing no more than $4M per applicant. This is subject to
WaterSMART’s future FY2014 appropriations, project funding capability, and the
amount remaining under the appropriations ceiling for each authorized project.
Approximately 5 to 10 awards are typically made each year.
Through the Title XVI Water Reclamation and Reuse Program, the Bureau provides
funding for projects that reclaim and reuse municipal, industrial, domestic or
agricultural wastewater and naturally impaired ground or surface waters. Reclaimed
water can be used for a variety of purposes, such as environmental restoration, fish
and wildlife, groundwater recharge, municipal, domestic, industrial, agricultural, power
generation or recreation.
The WaterSMART Program focuses on improving water conservation and
sustainability and helping water resource managers make sound decisions about water
use. It identifies strategies to ensure that this and future generations will have sufficient
supplies of clean water for drinking, economic activities, recreation and ecosystem
health. The program also identifies adaptive measures to address climate change and
its impact on future water demands. Through WaterSMART and other conservation
programs funded over the last three years, more than 580,000 acre-feet of water per
year is estimated to have been saved.
State Funding
The last two decades has seen an unprecedented series of bond measures passed by
the voters of California to fund water resources development throughout the State,
including reclamation projects. Beginning in 1996, voters passed a water-related
proposition roughly every four years as highlighted in the following list:
• Proposition 204 – Safe, Clean, Reliable Water Supply Act. (1996)
• Proposition 13 – Safe Drinking Water, Clean Water, Watershed Protection,
and Flood Protection Bond Act. (2000)
• Proposition 40 – The California Clean Water, Clean Air, Safe Neighborhood
Parks, and Coastal Protection Act of 2002 (2002)
• Proposition 50 – Water Quality, Supply and Safe Drinking Water Projects.
Coastal Wetlands Purchase and Protection. Bonds. (2002)
May 2013 71
Wastewater
Management
Plan
• Proposition 84 – Bonds for clean water, flood control, state and local park
improvements, etc. (2006)
The Clean Water State Revolving Loan Fund Program (CWSRF) was established by
the Federal Water Pollution Control Act, as amended in 1987. The CWSRF offers low
interest financing agreements for water quality improvement projects. Annually, the
program disburses between $200 and $300 M to eligible projects. Eligible projects
include construction of publicly-owned treatment facilities, such as wastewater
treatment, local sewers, sewer interceptors, water reclamation facilities, and storm
water treatment. Eligible applicants include and city, town, district, or other public body
created under state law and any designated and approved management agency under
Section 208 of the Clean Water Act. There exist favorable financing terms, including
low interest rate, 20 year repayment, up to $50M per agency per year, and deferred
repayment until 1 year after construction is completed.
May 2013 72
Wastewater
Management
Plan
7.0 LIST OF REFERENCES
Atkins. 2010 Urban Water Management Plan, prepared for Otay Water District, June,
2011.
Brown & Caldwell. San Diego Recycled Water Study, prepared for City of San Diego,
May 10, 2012.
CDM. Integrated Water Resources Plan, prepared for Otay Water District, March
2007.
City of San Diego New Regional Wastewater Disposal Agreement, May, 1998.
Final Environmental Assessment, Sycuan Band of the Kumeyaay Nation Fee-to-Trust,
August 2011.
Metcalf & Eddy. Spring Valley Sanitation District Water Reclamation Facility Project
Feasibility Report, prepared for County of San Diego, May 14, 1997.
Metropolitan Water District, San Diego County Water Authority and Otay Water District
LRP Agreement, July, 2005.
NBS Lowry. Wastewater and Recycling Optimization Study, prepared for Otay Water
District, November, 1995.
Otay Water District. RWCWRF 2007 Annual Report, January, 2008.
Otay Water District. RWCWRF 2008 Annual Report, February, 2009.
Otay Water District. RWCWRF 2009 Annual Report, February, 2010.
Otay Water District. Sewer System Management Plan Sewer Model Calibration,
Capacity Analysis, and System Assessment, February, 2006.
Otay Water District. Sewer System Management Plan, July, 2009.
PBS&J. County of San Diego Sewer System Management Plan, prepared for County
of San Diego, June, 2010.
May 2013 73
Wastewater
Management
Plan
PBS&J. Water Resources Master Plan Update, prepared for Otay Water District,
November, 2010.
PBS&J, Rancho San Diego Pump Station Sewer Flow Projection Study, prepared for
Spring Valley Sanitation District, April 2010.
Regional Wastewater Disposal Agreement, January, 2000
RMC. Acquisition of Additional Wastewater Capacity Project, Final Report, prepared
for City of Chula Vista, April, 2012.
South Bay Water Reclamation Plant Reclaimed Water Purchase Agreement, Oct 2003.
Spring Valley Sanitary District Sewer Agreement, May 1998.
Appendix A
Technical Memorandum: Recycled
Water Supply Augmentation Planning
Level Study
Technical Memorandum
Date: January 6, 2012
To: Bob Kennedy, Otay Water District
From: Liberato Tortorici, Malcolm Pirnie / ARCADIS
Brent Alspach, Malcolm Pirnie / ARCADIS
Re: Recycled Water Supply Augmentation Planning Level Study
I.I.I.I. Introduction Introduction Introduction Introduction
Malcolm Pirnie / ARCADIS (Malcolm Pirnie) was retained by the Otay Water District
(District) to perform a “high altitude level” planning study to evaluate options for
augmenting the District’s recycled water supply from the City of San Diego’s (City) South
Bay Water Reclamation Plant (SBWRP) with effluent from the International Boundary and
Water Commission (IBWC) South Bay International Wastewater Treatment Plant (SBIWTP).
The South Bay recycled water mains, along with the locations of the both the SBWRP and
the SBIWTP, are shown in Figure 1Figure 1Figure 1Figure 1. The District currently purchases an average of
approximately 5.9 MGD of recycled water from the City’s SBWRP and distributes that
water to recycled water customers within the District’s service area. The IBWC’s SBIWTP,
which is adjacent to the City’s SBWRP, was recently upgraded from an advanced primary to
a full secondary treatment facility and discharges an average of 25 MGD of secondary
effluent to the South Bay Land and Ocean Outfall system. The District is interested in
potentially reclaiming secondary effluent from the IBWC’s SBIWTP to augment the recycled
water supply from the City’s SBWRP as described under Option 1 below or to replace the
recycled water supply available from the City’s SBWRP as described under Option 2 below.
II.II.II.II. FFFFocus of Technical Mocus of Technical Mocus of Technical Mocus of Technical Memorandum emorandum emorandum emorandum
The focus of this memorandum is to develop planning level information, including process
requirements and estimates of probable capital and total annual costs, for the following
recycled water supply options:
Option 1Option 1Option 1Option 1 – Deliver SBIWTP Secondary Effluent to the City’s SBWRP
Option 2Option 2Option 2Option 2 – Partial Upgrade of the SBIWTP from Secondary to Tertiary Treatment
This technical memorandum is intended to provide the District with sufficient “high altitude
level” information to determine whether augmenting the District’s recycled water supply
with effluent from the SBIWTP might be economically viable and whether either or both of
the above options merit further development in more detailed study, conceptual design,
and/or preliminary design.
Bob Kennedy, Otay Water District January 6, 2012
Page 2 of 9
Figure 1Figure 1Figure 1Figure 1
South Bay Recycled Water MainsSouth Bay Recycled Water MainsSouth Bay Recycled Water MainsSouth Bay Recycled Water Mains
Bob Kennedy, Otay Water District January 6, 2012
Page 3 of 9
III.III.III.III. Definition of Recycled WDefinition of Recycled WDefinition of Recycled WDefinition of Recycled Water Supply Optionsater Supply Optionsater Supply Optionsater Supply Options
The two options for augmenting recycled water supplies are defined below. The
assumptions used for sizing of the required new facilities and for developing estimates of
probable costs are included in Appendix A. It should be noted that these assumptions
represent Malcolm Pirnie’s best estimate of existing facilities and recycled water quality
objectives; these assumptions need to be confirmed by the District prior to further
developing the concept in a more detailed planning study. Of particular importance in such
a planning study will be a detailed review and assessment of priority pollutants and
pollutants of concern which might render recycled water from the SBIWTP undesirable for
District recycled water end users.
Option 1Option 1Option 1Option 1 – Deliver SBIWTP Secondary Effluent to the City’s SBWRP
Under this option the following key project components as identified in Figure Figure Figure Figure 2222 would
need to be implemented:
• Construct effluent discharge piping from the IBWC’s SBIWTP to the City’s SBWRP
tertiary treatment facilities. These will include a 14” CMLDI pipeline and appurtenant
metering and control facilities.
• Utilize the existing tertiary filters, UV disinfection facilities, and recycled pumping
facilities on the City’s SBWRP site as shown in Figure 2. Note that California
Department of Public Health (CDPH) disinfection requirements vary depending on the
end use of recycled water; for some uses, disinfection may not be necessary. This
analysis conservatively assumes the use of full disinfection via the existing UV
disinfection system to allow the District the greatest flexibility for the sale of recycled
water to potential customers.
• Construct reverse osmosis (RO) facilities on the City’s SBWRP site to reduce the total
dissolved solids (TDS) in the recycled water supply. The TDS concentration in the
secondary effluent from the SBIWTP averages 1,600 mg/L. This dictates that a portion
of the filtered tertiary effluent will be processed through RO, with the desalinated
permeate blended with the remainder of the filtered effluent to produce recycled water
that would meet the District’s TDS goal of 1,000 mg/L. The RO concentrate would be
diverted to the existing South Bay Land Outfall and Ocean Outfall for disposal.
• Utilize the existing recycled water conveyance pipeline to deliver recycled water to the
District’s point of connection at Dairy Mart Road and Camino De La Plaza. The recycled
water will continue to be delivered to the District’s 450’ pressure zone.
These project components and facilities would yield a daily average recycled water
production of 12.9 MGD, as limited by the assumed ability of the City’s SBWRP tertiary
filters to accommodate 15 MGD of feed water. A recovery of 92% is assumed for the
existing tertiary filters, yielding a filtrate flow of 13.8 MGD, as shown in Figure 2 (i.e., 3.5 to
the RO system and 10.3 MGD directly to UV disinfection).
Figure 2
Option 1 – Deliver SBIWTP Secondary Effluent to the City’s SBWRP
Process Schematic
New Facilities are highlighted in Yellow
IBWC
South Bay International
Wastewater Treatment Plant
(SBIWTP)
Secondary Effluent: 7 MGD
TDS = 1,600 mg/L
1,530’ – 14” CMLDI Pipe
Tertiary
Filters
Reverse
Osmosis
3.5
MGD
UV Disinfection
Recycled
Water Pump
Station
OWD
450 Zone
Distribution System
12.9 MGD
TDS = 1,000 mg/L
City of San Diego
South Bay Water
Reclamation Plant
(SBWRP)
Secondary Effluent: 8 MGD
TDS = 933 mg/L
12.9 MGD
10.3 MGD 2.6 MGD
Filter Residuals: 1.2 MGD
to SBLO
RO Brine: 0.9 MGD
to SBLO
Bob Kennedy, Otay Water District January 6, 2012
Page 5 of 9
Option 2Option 2Option 2Option 2 – Partial Upgrade of the SBIWTP from Secondary to Tertiary Treatment
Under this option the following key project components as identified in Figure Figure Figure Figure 3333 would
need to be implemented:
• Construct new tertiary treatment facilities (micro-/ultrafiltration (MF/UF), RO, and UV
disinfection) on the SBIWTP site to produce an average recycled water supply of 15
MGD. The TDS concentration in the secondary effluent from the SBIWTP averages
1,600 mg/L. This dictates that a portion of the filtered tertiary effluent will be
processed through RO, with the desalinated permeate blended with the remainder of
the filtered effluent to produce recycled water that would meet the District’s TDS goal
of 1,000 mg/L. The RO concentrate would be diverted to the existing South Bay Land
Outfall and Ocean Outfall for disposal. As indicated in conjunction with Option 1, CDPH
disinfection requirements vary depending on the end use of recycled water; for some
uses, disinfection may not be necessary. As with Option 1, this analysis conservatively
assumes the use of full disinfection to allow the District the greatest flexibility for the
sale of recycled water to potential customers. Although both chemical (e.g., chlorine)
or UV disinfection are permitted under CDPH regulations, the use of UV disinfection is
increasingly employed in recycled water treatment applications, including the SBWRP
and the Orange County Water District’s landmark Groundwater Replenishment System.
In addition to being chemical-free, UV disinfection avoids the need to construct a tank
or basin for chemical disinfectant contact time. As a result, UV disinfection is assumed
in this evaluation.
• Construct a new recycled water pump station on the SBIWTP site.
• Construction effluent discharge piping from the SBIWTP to the deliver recycled water
to the District’s point of connection at Dairy Mart Road and Camino De La Plaza. These
will include a 30” CMLDI pipeline and appurtenant metering and control facilities. The
recycled water will continue to be delivered to the District’s 450’ pressure zone.
The daily average recycled water production would be 15.0 MGD. Unlike Option 1, the
capacity of Option 2 is not limited by the capacity of existing facilities. Sufficient
secondary effluent from the SBIWTP is available to provide the full 15 MGD flow desired by
the District.
RO Brine: 1.9 MGD
to SBLO
Figure 3
Option 2 – Partial Upgrade of the SBIWTP from Secondary to Tertiary Treatment
Process Schematic
IBWC
South Bay International
Wastewater Treatment Plant
(SBIWTP)
Secondary Effluent:
18.4 MGD
TDS = 1,600 mg/L
Micro/Ultra
Filtration
Reverse
Osmosis
7.6
MGD
UV Disinfection
9.3 MGD 5.7 MGD
Recycled
Water Pump
Station
OWD
450 Zone
Distribution System
New Facilities are highlighted in Yellow
15 MGD
5,690’ – 30” CML DIP
15 MGD
Filter Residuals: 1.5 MGD
to SBLO
Bob Kennedy, Otay Water District January 6, 2012
Page 7 of 9
IV.IV.IV.IV. Estimates of Probable CostsEstimates of Probable CostsEstimates of Probable CostsEstimates of Probable Costs
Estimates of probable construction and annual total costs presented in Appendix A and
summarized below for this “high altitude level” planning study are consistent with the
Association for Advancement of Cost Engineering (AACE) Class 5 Order of Magnitude
Estimates and are based on October 2011 dollars. However, it should be noted that
estimates of probable costs do not not not not include the costs for potential upsizing of the SDG&E
power supply and/or potential upsizing of in-plant power distribution systems at SBIWTP or
at the SBWRP.
Option 1Option 1Option 1Option 1 – Deliver SBIWTP Secondary Effluent to the City’s SBWRP
Construction costs $4,048,800
Pre-design costs $106,300
Engineering costs $424,900
Post design and CM costs $531,100
District admin/permitting costs $212,500
Project contingencies $318,800
Estimate of probable capital costs** $5,642,400
Estimate of annual capital costs (amortized)** $491,500
Estimate of annual O&M costs** $2,569,400
Estimate of total annual costs** $3,060,900
EsEsEsEstimatetimatetimatetimate of total recycled water costof total recycled water costof total recycled water costof total recycled water cost******** $59$59$59$590000/acre/acre/acre/acre----footfootfootfoot
** See Appendix A for a detailed breakdown of costs
Option 2Option 2Option 2Option 2 – Partial Upgrade of the SBIWTP from Secondary to Tertiary Treatment
Construction costs $37,623,500
Pre-design costs $940,600
Engineering costs $3,762,400
Post design and CM costs $4,702,900
District admin/permitting costs $1,881,200
Project contingencies $2,821,800
Estimate of probable capital costs** $51,732,400
Estimate of annual capital costs (amortized)** $4,505,900
Estimate of annual O&M costs** $6,177,500
Estimate of total annual costs** $10,683,400
EsEsEsEstimate of total recycled water costtimate of total recycled water costtimate of total recycled water costtimate of total recycled water cost******** $67$67$67$670000/acre/acre/acre/acre----footfootfootfoot
** See Appendix “A” for detailed breakdown of costs
Bob Kennedy, Otay Water District January 6, 2012
Page 8 of 9
The estimate of total recycled water costestimate of total recycled water costestimate of total recycled water costestimate of total recycled water cost for Option 1 represents only the costs for
producing an additional 4.9 MGD of recycled water and does notnotnotnot include any associated
amortized capital costs or operating costs for existing SBWRP treatment facilities
upstream of the new facilities identified for Option 1. These estimates also do notnotnotnot include
potential upsizing of SDG&E’s power supply and/or upsizing of the in-plant power
distribution facilities at the SBWRP. It is Malcolm Pirnie’s understanding that the SBWRP is
currently served from the same redundant SDG&E 12 kV feeders identified below. The
discussion below in the context of Option 2 outlines potential costs to upsize SDG&E power
service from 12 kV to 69 kV.
The estimate of total recycled water costestimate of total recycled water costestimate of total recycled water costestimate of total recycled water cost for Option 2 does notnotnotnot include any associated
amortized capital costs or operating costs for existing SBIWTP treatment facilities
upstream of the new facilities identified for Option 2. These estimates also do notnotnotnot include
potential upsizing of SDG&E’s power supply and/or upsizing of the in-plant power
distribution facilities at the SBIWTP. SDG&E provides power to the SBIWTP via a
redundant 12 kV service, which is sufficient for the existing power loads for the current
average design flow of 25 MGD. It is Malcolm Pirnie’s understanding that this power
service will need to be upsized to 69 kV to augment power loads in conjunction with the
additional treatment. Based on records from Malcolm Pirnie’s previous work with the
IBWC, it is believed that a Memorandum of Understanding (MOU) between the IBWC and
SDG&E signed in late 1995 establishes that SDG&E would upgrade to a 69 kV services at its
expense ($5 million in Year 2000 dollars) when the combined City and IBWC plant loads
exceed the capacity of the existing SDG&E 12 kV service. However, Malcolm Pirnie does
not have a copy of the MOU and is unable to confirm this agreement.
V.V.V.V. RRRRecommendationsecommendationsecommendationsecommendations
Should the District decide to pursue either or both of the options identified in this Technical
Memorandum, the following actions are recommended:
1. Option 1 assumes the use of the existing tertiary media filters at the SBWRP
pretreatment prior to the RO system. The use of media filters is notnotnotnot an industry
standard practice for RO system pretreatment and will need to be further evaluated to
determine whether this is feasible or if more standard MF/UF technology is necessary.
2. The RO system is based on lowering TDS concentrations to produce a blended
filtrate/RO permeate with a TDS concentration of 1,000 mg/L. Other constituents such
as chlorides, sulfates, boron, and/or priority pollutants were not considered in this
planning level study. A more detailed review and assessment of these and other
constituents will need to be undertaken.
3. Consult the Regional Water Quality Control Board to obtain its preliminary opinion and
requirements for the District to pursue disposal of RO concentrate to the ocean
through the South Bay Land and Ocean Outfall system.
Bob Kennedy, Otay Water District January 6, 2012
Page 9 of 9
4. The SBIWTP only treats flows from Mexico, and on occasion there have been upsets at
the plant. These upsets are thought to be related to constituents in the influent
wastewater flows that are inhibitory to the activated sludge process. Such upsets may
continue in the future and thus may impact the ability to produce an uninterrupted
recycled water supply from the SBIWTP secondary effluent supply. The District should
consider the impact of these potential upsets on the ability to deliver recycle water to
its customers. Accordingly, it is recommended that the District conduct a detailed
review of historical effluent data for the SBIWTP to assess potential constituents of
concern and priority pollutants relative to the District’s recycled water quality
objectives.
5. Confirm the assumptions contained herein and in Appendix A.
6. Evaluate the ability of the SBWRP and SBIWTP to accommodate the additional power
loads that will be required to support the new facilities identified for both options. This
will required a detailed review and assessment of the existing motor control centers,
power supply facilities, and power distribution facilities.
7. Request a copy of the Memorandum of Understanding signed by the IBWC and SDG&E in
late 1995, and evaluate the ability of SDG&E to accommodate the additional power
loads that will be required to support the new facilities identified for Option 1 and
Option 2. This will require a detailed listing or current and future power loads and
consultation with SDG&E.
8. Consult with the City to obtain its preliminary opinion on both locating additional
facilities on the SBWRP site and operating the additional facilities.
9. It is Malcolm Pirnie’s understanding that treated water from the SBIWTP belongs to
Mexico, which may require compensation in either the form of payments and/or
delivery of a portion of the recycled water to Mexico at little or no cost. It is also
Malcolm Pirnie’s understanding that the cost for operation and maintenance of the
existing SBIWTP is shared between the US and Mexico, and that Mexico's contribution
towards O&M consists of both an annual payment to the US Section for volume of
wastewater treated, as well as full responsibility for hauling and disposal of residual
solids generated at the SBIWTP. The District should consult with the IBWC - US Section
to obtain its preliminary thoughts on potentially locating and operating additional
treatment facilities on the SBIWTP site, as well as on potential agreements and financial
arrangements that may be required by the IBWC - US Section and the IBWC - Mexico
Section to reclaim and recycle water from wastewater flows that originate in Mexico.
10. Undertake a detailed study and prepare a focused Facility Plan to address the
recommendations identified above and to further develop and evaluate the options
presented herein.
Appendix A:Appendix A:Appendix A:Appendix A:
Cost EstimatesCost EstimatesCost EstimatesCost Estimates
A-1
A.1:A.1:A.1:A.1: Project AssumptionsProject AssumptionsProject AssumptionsProject Assumptions
EEEEFFLUENT FFLUENT FFLUENT FFLUENT QQQQUALUALUALUALITYITYITYITY
1. IBWC SBIWTP secondary effluent TDS = 1,600 mg/L (average for January 2011 through
July 2011)
2. City’s South Bay Plant tertiary effluent TDS = 933 mg/L (average for 2007, 2008, and
2009). This is not to exceed 1,000 mg/l.
3. Recycled water target TDS = 1,000 mg/L per Bob Kennedy 10/4/11 e-mail
4. Recycled water demand is 15 MGD per 9/22/11 scoping meeting with Bob Kennedy
OOOOPTION PTION PTION PTION 1111: : : : Deliver SBIWTP Secondary Effluent to City’s South Bay Plant Deliver SBIWTP Secondary Effluent to City’s South Bay Plant Deliver SBIWTP Secondary Effluent to City’s South Bay Plant Deliver SBIWTP Secondary Effluent to City’s South Bay Plant
(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)
1. Current SBWRP peak reclaimed water production = 8 MGD (peaks for 2007, 2008,
2009)
2. City’s SBWRP tertiary treatment and pumping system has firm feed capacity of 15 MGD
3. Deliver 7 MGD of SBIWTP secondary effluent to SBWRP
4. Treat 7 MGD of SBIWTP secondary effluent via SBWRP tertiary filters
5. Recovery of SBWRP tertiary filters is 92%
6. Blended effluent without RO will be as follows: [City’s effluent: 8 MGD @ 933 mg/L TDS]
+ [SBIWTP filtered effluent: 7 MGD @ 1,600 mg/L TDS] = 15 MGD @ 1,244 mg/L
7. RO system: 98% rejection and 75% recovery
8. RO with 98% rejection of TDS and permeate flow of 2.6 MGD yields a blended finished
water of 1,000 mg/L TDS
9. Size RO @ 2.6 MGD permeate
10. Combined tertiary filtrate (10.3 MGD) and RO permeate (2.6 MGD) yields 12.9 MGD
11. Utilize existing SBWRP 15 MGD UV facility
12. Size SBIWTP secondary effluent line to City’s South Bay Plant for velocity of 10 fps @
7 MGD.
- Use 14” CMLDI pipe
- Per Google maps install 1,530’ of pipe from the SBIWTP EDS to the City’s tertiary
treatment facilities
OOOOPTION PTION PTION PTION 2222: : : : Partial Upgrade of Partial Upgrade of Partial Upgrade of Partial Upgrade of the SBIWTP from the SBIWTP from the SBIWTP from the SBIWTP from Secondary to Tertiary TreatmentSecondary to Tertiary TreatmentSecondary to Tertiary TreatmentSecondary to Tertiary Treatment
(15.0(15.0(15.0(15.0 MGD Recycled Water Production)MGD Recycled Water Production)MGD Recycled Water Production)MGD Recycled Water Production)
1. Treat 18.4 MGD of SBITWP secondary effluent via MF/UF
2. Target finished recycled water TDS of 1,000 mg/L
3. RO system: 98% TDS rejection and 75% recovery
4. MF/UF system: 92% recovery
5. Blended effluent will be as follows: [SBIWTP MF/UF filtrate: 9.3MGD MF/UF filtrate @
1,600 mg/L TDS] + [5.7 MGD RO permeate @ 25 mg/L TDS] = 15 MGD @ 1,000 mg/L
TDS
6. Size MF/UF @ 16.9 MGD filtrate (9.3 MGD directly to UV and 7.6 MGD to RO), requiring
18.4 MGD feed
A-2
7. Size RO @ 5.7 MGD permeate, requiring 7.6 MGD feed
8. Size UV for 15 MGD
9. Size new recycled water pump station for 15 MGD
10. Size SBIWTP recycled water effluent line to District tie-in on Dairy Mart Road and
Camino De La Plaza for velocity of 5 fps @ 15 MGD
- Use 30” CMLDI pipe
- Per Google maps install 5,690’ of pipe from the SBIWTP EDS to the District Tie-in
A.2:A.2:A.2:A.2: Estimates of Probable Construction CostsEstimates of Probable Construction CostsEstimates of Probable Construction CostsEstimates of Probable Construction Costs
CCCCOST OST OST OST AAAASSUMPTIONSSSUMPTIONSSSUMPTIONSSSUMPTIONS
1. Estimates based on October 2011 dollars
2. Power costs based on $0.135 per kWh per IBWC power bills
3. Costs do not not not not include potential upsizing of SDG&E power supply and/or in-plant power
distribution upsizing
OOOOPTION PTION PTION PTION 1111: : : : Deliver SBIWTP Secondary Effluent to City’s South Bay Plant Deliver SBIWTP Secondary Effluent to City’s South Bay Plant Deliver SBIWTP Secondary Effluent to City’s South Bay Plant Deliver SBIWTP Secondary Effluent to City’s South Bay Plant
(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)
1. SBIWTP Secondary Effluent Pipeline to City’s South Bay Plant
- 1,530’ of 14” CMDI pipe
- use $15 per inch-foot installed
- Installed cost:
1,530’ x 14” x $15/inch-foot = $321,300
Corrosion protection @ 7% = $23,000
Traffic control @ 7% = $23,000
Contingencies @ 25% = $80,400
Conveyance costs $447,700
2. Reverse Osmosis (RO) @ 2.6 MGD Capacity
- Assumes 98% TDS rejection and 75% recovery
- Manufacture installed cost @ $0.74/gpd (Includes: skid frame, pressure vessels,
membranes, cartridge filters, valves, pumps, piping, instrumentation, control panel,
cleaning equipment, and other associated appurtenances) = $1,924,000
Contractor P&OH @ 15% = $291,300
Electrical & I&C @ 18% = $346,300
Contingencies @ 25% = $481,000
RO costs $3,042,600
3. Sub - total estimate of probable construction costs $3,490,300
Contractor Division 1 costs @ 10% $349,000
Contractor Bonds & Insurance @ 6% $209,500
Option 1 Option 1 Option 1 Option 1 ---- ttttotal estimate ootal estimate ootal estimate ootal estimate of probable construction costsf probable construction costsf probable construction costsf probable construction costs $4,048,800$4,048,800$4,048,800$4,048,800
A-3
OOOOPTION PTION PTION PTION 2222: : : : Partial Upgrade of Partial Upgrade of Partial Upgrade of Partial Upgrade of the SBIWTP from Sethe SBIWTP from Sethe SBIWTP from Sethe SBIWTP from Secondary to Tertiary Treatmentcondary to Tertiary Treatmentcondary to Tertiary Treatmentcondary to Tertiary Treatment
(15.0(15.0(15.0(15.0 MGD Recycled Water Production)MGD Recycled Water Production)MGD Recycled Water Production)MGD Recycled Water Production)
1. SBIWTP Recycled Water Pipeline to District tie-in on Dairy Mart Road and Camino De La
Plaza
- 5,690’ of 30” CMDI pipe
- use $15 per inch-foot installed
- Installed cost:
5,690’ x 30” x $15/inch-foot = $2,560,500
Corrosion protection @ 5% = $128,000
Traffic control @ 5 % = $128,000
Contingencies @ 25% = $640,000
Conveyance costs $3,456,500
2. New 15 MGD Recycled Water Pump Station
- Assume wet well similar to SBIWTP NPW PS (36’L x 18’W x 22’D)
- Concrete quantities
Walls: 2 x (36’L x 22’D x 1.25’T)/27 = 73 cubic yards
Walls: 2 x (18’L x 22’D x 1.25’T)/27 = 37 cubic yards
Slab: 40’L x 22’W x 2’T)/27 = 65 cubic yards
Top: 36’L x 18’W x 1.5’T/27 = 36 cubic yards
Total 211 cubic yards
- Construction Costs
Concrete: 211 cubic yards @ $900/cy = $189,900
Contractor P&OH @ 15% = $28,500
Excavation & Backfill @ 8% = $15,200
Supplier services @ 4% = $7,600
Misc metals @ 8% = $15,200
Electrical & I&C @ 20% = $38,000
Coatings @ 7 % = $13,300
Contingencies @ 25% = $47,500
Structure costs $355,200
- Equipment Costs
Need 6 Fairbanks Morse 6 stage vertical turbine pumps (Model 14F)
Capacity of each pump is 2,100 GPM @ 507’ TDH (5 operating)
Use 3 VFD driven pumps and 3 “soft start” constant speed pumps
Purchase price:
6 pumps @ $162,000 each = $972,000
3 VDS @ $105,000 each = $315,000
Purchase price $1,287,000
A-4
Tax & Delivery @ 12.5% = $160,900
Contractor P&OH @ 15% = $193,100
Manufacturer services @ 4% = $51,500
Install @ 10% = $128,700
Piping & Valves @15% = $193,000
Surge Protection @ 10% = $128,700
Electrical & I&C @ 18% = $231,700
Metering @ 5% = $64,400
Contingencies @ 25% = $321,800
Pumping/Piping costs $2,760,800
3. Microfiltration / Ultrafiltration System @ 16.9 MGD Filtrate Capacity
- Assumes 92% recovery
Manufacture installed cost @ $0.38/gpd (Includes: pressure vessels, membranes,
strainers, valves, pumps, piping, instrumentation, control panel, cleaning equipment,
integrity testing equipment, and other assoc. appurtenances) = $6,440,000
Contractor P&OH @ 15% = $966,000
Electrical & I&C @ 18% = $1,159,200
Contingencies @ 25% = $1,610,000
MF/UF costs $10,175,200
4. Reverse Osmosis System @ 5.7 MGD Permeate Capacity
- Assumes 98% TDS rejection and 75% recovery
Manufacturer installed cost @ $0.74/gpd Includes: skid frame, pressure vessels,
membranes, cartridge filters, valves, pumps, piping, instrumentation, control panel,
cleaning equipment, and other associated appurtenances = $2,966,000
Contractor P&OH @ 15% = $444,900
Electrical & I&C @ 18% = $533,900
Contingencies @ 25% = $741,500
RO costs $4,686,300
5. UV Disinfection (UV) @ 15 MGD Capacity
- Assumes 80 mJ/cm2 dose and 65% UV transmittance
- Based on Indianapolis Belmont UV Disinfection Facility
Total construction cost = $11,000,000
6. Sub - total estimate of probable construction costs = $32,434,000
Contractor Division 1 costs @ 10% $3,243,400
Contractor bonds and insurance @ 6% $1,946,100
Option 2 Option 2 Option 2 Option 2 ---- ttttotal estimate ofotal estimate ofotal estimate ofotal estimate of probable construction costsprobable construction costsprobable construction costsprobable construction costs $37,623,500$37,623,500$37,623,500$37,623,500
A-5
A.3:A.3:A.3:A.3: Estimates of Probable Capital CostsEstimates of Probable Capital CostsEstimates of Probable Capital CostsEstimates of Probable Capital Costs
CCCCOST OST OST OST AAAASSUMPTIONSSSUMPTIONSSSUMPTIONSSSUMPTIONS
1. Estimates based on October 2011 dollars
2. Pre-design investigations @ 2.5%
3. Engineering costs based on 10% of construction costs
4. Post design and CM costs based on 12.5%
5. District administration and permitting costs based on 5%
6. Project contingencies based on 7.5%
OOOOPTION PTION PTION PTION 1111: : : : Deliver SBIWTP Secondary Effluent to CitDeliver SBIWTP Secondary Effluent to CitDeliver SBIWTP Secondary Effluent to CitDeliver SBIWTP Secondary Effluent to City’s South Bay Plant y’s South Bay Plant y’s South Bay Plant y’s South Bay Plant
(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)
Construction costs $4,048,800
Pre-design costs $106,300
Engineering costs $424,900
Post design and CM costs $531,100
District admin/permitting costs $212,500
Project contingencies $318,800
Option 1 Option 1 Option 1 Option 1 –––– ttttotal capital cost estimateotal capital cost estimateotal capital cost estimateotal capital cost estimate $5,642,400$5,642,400$5,642,400$5,642,400
OOOOPTION PTION PTION PTION 2222: : : : Partial Upgrade of Partial Upgrade of Partial Upgrade of Partial Upgrade of the SBIWTP from Secondary to Tertiary Treatmentthe SBIWTP from Secondary to Tertiary Treatmentthe SBIWTP from Secondary to Tertiary Treatmentthe SBIWTP from Secondary to Tertiary Treatment
(15.0(15.0(15.0(15.0 MGD Recycled Water Production)MGD Recycled Water Production)MGD Recycled Water Production)MGD Recycled Water Production)
Construction costs $37,623,500
Pre-design costs $940,600
Engineering costs $3,762,400
Post design and CM costs $4,702,900
District admin/permitting costs $1,881,200
Project contingencies $2,821,800
Option 2 Option 2 Option 2 Option 2 ---- ttttotal capital cost estimateotal capital cost estimateotal capital cost estimateotal capital cost estimate $51,732,400$51,732,400$51,732,400$51,732,400
A-6
A.4:A.4:A.4:A.4: Estimates of Estimates of Estimates of Estimates of Probable Probable Probable Probable AnnualAnnualAnnualAnnual CostsCostsCostsCosts
CCCCOST OST OST OST AAAASSUMPTIONSSSUMPTIONSSSUMPTIONSSSUMPTIONS
1. Estimates based on October 2011 dollars
2. Power costs based on $0.135 per kWh per IBWC power bills
3. Annual capital costs based 20 year amortization and 6% interest (CR factor = 0.0871)
OOOOPTION PTION PTION PTION 1111: : : : Deliver SBIWTP SecondaDeliver SBIWTP SecondaDeliver SBIWTP SecondaDeliver SBIWTP Secondary Effluent to City’s South Bay Plant ry Effluent to City’s South Bay Plant ry Effluent to City’s South Bay Plant ry Effluent to City’s South Bay Plant
(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)(12.9 MGD Recycled Water Production)
1. Annual capital costs $5,642,400 x 0.0871 = $491,500/year
2. RO operating costs @ $1.47/kgal) = $1,395,000/year
Includes: power, labor, chemicals, membrane replacement, maintenance
3. Pumping costs for additional 6.9 MGD beyond the current 6 MGD average flow supplied
by the City’s SBWRP $852,300/year
(2,100 HP x 24 hrs/day x 365 days/yr x 0.746 kW/HP x $0.135/kWh x 6.9 MGD/15 MGD)
4. Labor costs $322,100/year
(1.5 operator x 12 hrs/day x $35/hr x 365 days/yr x 1.40 overhead)
5. Total annual cost estimate = $3,060,900
6.6.6.6. Cost per acreCost per acreCost per acreCost per acre----foot fofoot fofoot fofoot for 4.9 MGD additional supply =r 4.9 MGD additional supply =r 4.9 MGD additional supply =r 4.9 MGD additional supply = $59$59$59$590/acre0/acre0/acre0/acre----footfootfootfoot
OOOOPTION PTION PTION PTION 2222: : : : Partial Upgrade of Partial Upgrade of Partial Upgrade of Partial Upgrade of the SBIWTP from Secondary to Tertiary Treatmentthe SBIWTP from Secondary to Tertiary Treatmentthe SBIWTP from Secondary to Tertiary Treatmentthe SBIWTP from Secondary to Tertiary Treatment
(15.0(15.0(15.0(15.0 MGD Recycled Water Production)MGD Recycled Water Production)MGD Recycled Water Production)MGD Recycled Water Production)
1. Annual capital costs $51,732,400 x 0.0871 = $4,505,900/year
2. MF/UF operating costs @ $0.12/kgal + $740,000/year
Includes: power, labor, chemicals, membrane replacement, maintenance
3. RO operating costs @ $1.20/kgal) = $2,597,400 / year
Includes: power, labor, chemicals, membrane replacement, maintenance
4. Pumping costs $1,852,700/year
(2,100 HP x 24 hrs/day x 365 days/yr x 0.746 kW/HP x $0.135/kWh)
5. Labor costs $572,400/year
(2 operator x 16 hrs/day x $35/hr x 365 days/yr x 1.40 overhead)
6. UV operating costs @ $415,000/year
7. Total annual cost estimate = $10,683,400/year
8.8.8.8. Cost per acreCost per acreCost per acreCost per acre----foot for 15 MGDfoot for 15 MGDfoot for 15 MGDfoot for 15 MGD $67$67$67$670/acre0/acre0/acre0/acre----footfootfootfoot
THIS PAGE INTENTIONALLY LEFT BLANK
Appendix B
RWCWRF Expansion Options Site
Layout
OPTION C
ARCADIS U.S., INC.
7/25/2012
OTAY WATER DISTRICT
2554 SWEETWATER SPRINGS BLVD. SPRING VALLEY CA
OPTION A
OPTION BOPTION C
OPTION A & B
OPTION C
NEW
CENTRIFUGE
FACILITIES
NEW
SECONDARY
CLARIFIER
EXPANSION
OPTION A
NEW DAF
FACILITIES
ACTIVATED SLUDGE
EXPANSION
OPTION C OPTION B & C
OPTION B
NEW SCUM TANK
AND PUMP STATION
OPTIONS B & C
MODIFY & EXPAND EXISTING WAS PUMP STATION
OPTIONS B & C
NEW BLOWER AND ELECTRICAL BUILDING, OPTIONS B & C
REMOVE EXISTING RO BUILDING FOR NEW CONSTRUCTION
RELOCATE EXISTING MOBILE OFFICE FOR NEW CONSTRUCTION
OPTION C
OPTION B
NEW EFFLUENT
PUMP STATION EXPANSION
NEW PARKING
OPTION C ONLY
NEW ADMINISTRATION BUILDING
OPTION C ONLY
NEW TERTIARY
FILTRATION
EXPANSION
OPTION B & C
NEW AEROBIC
DIGESTION
FACILITIES
NEW SODIUM
HYPOCHLORITE
STORAGE & FEED
OPTION B
OPTION C
OPTION B
OPTION B & C
NEW CHLORINE
CONTACT TANK
NEW DIGESTED
SLUDGE PUMP
STATION
OPTION A
OPTION B
OPTION C
OPTION A OPTION B
OPTION C
RECONFIGURE ROADWAY UNDER AERATION BASIN
OPTION C SCENARIO
EXTEND EXISTING ROADWAY
TO NEW SOLIDS HANDLING FACILITIES
OPTION A
NEW HEADWORKS
(SCREENINGS & GRIT HANDLING )
OPTIONS B & C
CONSTRUCT NEW INFLUENT PUMP STATION (AT EXISTING SBPS SITE)
OPTION B = (3) SUBMERSIBLE PUMPS (TWO OPERATING, ONE STANDBY)
8" PUMP DISCHARGE WITH TIE-IN TO 12" DISCHARGE MANIFOLD
SLAB ON GRADE = 70' x 15' +/-.
WETWELL INSIDE DIMENSIONS + 61" L x 10' W x 23' SIDEWALL DEPT +/-.
OPTION C = (3) SUBMERSIBLE PUMPS (TWO OPERATING, ONE STANDBY)
10" PUMP DISCHARGE WITH TIE-IN TO 14" DISCHARGE MANIFOLD
SLAB ON GRADE = 70' X 22' +/-.
WETWELL INSIDE DIMENSIONS + 61" L x 15' W x 23' SIDEWALL DEPT +/-.
SCALE: APPROXIMATELY 1" = 40'
LEGEND:
OPTION A
OPTION B
OPTION C
UPGRADE AND EXPANSION OPTIONS
FOR THE RALPH W. CHAPMAN WATER RECLAMATION FACILITYWASTEWATER MANAGEMENT PLAN
OTAY CONTRACT NUMBER; S1210-026000
SCALE: 1" = 40'
020 20 40
Us
e
r
:
L
A
R
S
O
N
S
p
e
c
:
P
I
R
N
I
E
S
T
A
N
D
A
R
D
F
i
l
e
:
G
:
\
P
r
o
j
e
c
t
s
\
4
0
9
4
-
O
t
a
y
W
D
\
0
4
0
9
0
0
7
-
O
P
T
I
O
N
S
A
B
C
.
D
W
G
S
c
a
l
e
:
1
:
1
D
a
t
e
:
0
7
/
2
4
/
2
0
1
2
T
i
m
e
:
1
6
:
0
1
L
a
y
o
u
t
:
B
l
a
n
k
XR
E
F
S
:
I
M
A
G
E
S
:
K
:
\
S
y
m
b
o
l
s
2
0
0
0
\
P
i
r
n
i
e
S
t
a
n
d
a
r
d
\
G
e
n
\
M
P
I
T
i
t
l
e
B
l
o
c
k
s
\
P
i
r
n
i
e
-
A
U
S
_
W
a
t
e
r
.
j
p
g
MODIFY & EXPAND EXISTING WAS PUMPING
ALONG SOUTH SIDE OF SECONDARY CLARIFIERS
OPTIONS B & C
Appendix C
Technical Memorandum: Summary of
Costs Associated with Upgrade,
Expansion and Decommissioning of
the Ralph W. Chapman Water
Reclamation Facility
Technical Memorandum
KEH & Associates, Inc. 2173 Salk Avenue, Suite 250 Carlsbad, CA 92008 P: 760-579-7650 F: 760-579-7651
Date: October 29, 2012
To: Steve Davis; ARCADIS
CC: Libby Tortorici; ARCADIS
Tim Francis; ARCADIS
Ray Fakhoury; KEH & Associates
From: Ken Hume; KEH & Associates
Subject: Otay Water District RWCWRF Assessment of Capital Cost -
Process Upgrades, Expansions and Estimates of Probable Construction Costs for
Various Treatment Plant Capacity Options
The following final technical memorandum is in response to the scope of work identified in our
subconsultant agreement dated February 21, 2012, which supports the development of the Otay Water
District Wastewater Management Plan. Review comments to the memorandum provided by ARCADIS
on September 12, 2012 are addressed herein. Feedback regarding CT criteria for CA Title 22 disinfection
as received on October 29, 2012 is also incorporated into this final memorandum. The information is
presented in the following three major areas:
• Part A - Estimate Of Conceptual Capital Costs
• Part B - Estimate Of Additional Conceptual Power Consumption Costs
• Part C - Estimate Of Additional Conceptual Chemical Costs
Costs are broken down based on unit processes at the Ralph W. Chapman Water Recycling Facility and
the alternatives identified by ARCADIS, which are summarized as follows:
• Option A – Maintain Wastewater Treatment, do not Expand RWCWRF
• Option B – Maintain Wastewater Treatment, Expand RWCWRF To 2.6 MGD
• Option C – Maintain Wastewater Treatment, Expand RWCWRF To 3.9 MGD
• Option D – Eliminate Wastewater Treatment, Abandon RWCWRF
An executive summary provides a review of the results of the assessment discussed above. A
description of assessment criteria and cost estimate accuracy is presented in the executive summary.
Thank you for the opportunity to work with your team on this important project for the Otay Water
District.
Sincerely,
KEH & Associates, Inc.
Kenneth E. Hume
Principal
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 2
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
TABLE OF CONTENTS
Executive Summary ....................................................................................................................................... 3
Part A – Estimate of Conceptual Capital Costs ............................................................................................. 6
1. Influent Pump Station Sizing Criteria and Estimates of Probable Construction Costs for Various
Treatment Plant Capacities .............................................................................................................. 6
2. Headworks and Grit Removal Sizing Criteria and Estimates of Probable Construction Costs for
Various Treatment Plant Capacities ................................................................................................. 9
3. Aeration Basin Sizing Criteria and Estimates of Probable Construction Costs for Various
Treatment Plant Capacities ............................................................................................................ 12
4. Secondary Clarifiers Sizing Criteria and Estimates of Probable Construction Costs for Various
Treatment Plant Capacities ............................................................................................................ 16
5. RAS/WAS Pump Station Sizing Criteria and Estimates of Probable Construction Costs for Various
Treatment Plant Capacities ............................................................................................................ 19
6. Aerobic Digestion Sizing Criteria and Estimates of Probable Construction Costs for Various
Treatment Plant Capacities ............................................................................................................ 22
7. Digested Sludge Pump Station Sizing Criteria and Estimates of Probable Construction Costs for
Various Treatment Plant Capacities ............................................................................................... 28
8. Scum Pump Station Sizing Criteria and Estimates of Probable Construction Costs for Various
Treatment Plant Capacities ............................................................................................................ 32
9. Effluent Pump Station Sizing Criteria and Estimates of Probable Construction Costs for Various
Treatment Plant Capacities ............................................................................................................ 33
10. Administration Building Sizing Criteria and Estimates of Probable Construction Costs for Various
Treatment Plant Capacities ............................................................................................................ 37
11. Blower and Electrical Building with Standby Power Generation Sizing Criteria and Estimates of
Probable Construction Costs for Various Treatment Plant Capacities .......................................... 40
12. WAS Thickening Sizing Criteria and Estimates of Probable Construction Cost for Various
Treatment Plant Capacities ............................................................................................................ 44
13. Sludge Dewatering Centrifuge Sizing Criteria and Estimates of Probable Construction Costs for
Various Treatment Options ........................................................................................................... 49
14. Tertiary Filter Sizing Criteria and Estimates of Probable Construction Costs for Various Treatment
Plant Capacities .............................................................................................................................. 53
15. Chlorine Contact Tank, Sodium Hypochlorite Storage and Chemical Feed facilities for Tertiary
Disinfection .................................................................................................................................... 55
16. Option D – Decommissioning of RWCWRF and SBPS - Overview .................................................. 60
Part B – Estimate of Additional Conceptual Power Consumption Costs .................................................... 63
Part C – Estimate of Additional Conceptual Chemical Consumption ......................................................... 69
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 3
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Executive Summary
The capital costs presented herein are based on the description of WWMP Options prepared by
ARCADIS and titled "Alternatives Fact Sheets". The information presented in this Technical
Memorandum is related to the Ralph W. Chapman Water Recycling Facility (RWCWRF) and Steel Bridge
Pump Station, as identified under Options A through D of the Alternatives Fact Sheets as developed by
ARCADIS. The information presented herein is intended to provide a general basis for management
planning of wastewater infrastructure by the District. The memorandum does not include a detailed
assessment of existing operations or evaluation of unit process alternatives, which would be considered
a pre-design effort and not a part of the scope of this planning level assessment. The unit processes for
secondary and tertiary treatment of wastewater consider expansions of existing processes at the
RWCWRF, and those considered for solids handling were selected as examples of typical treatment
processes employed at municipal wastewater treatment facilities in California.
Capital costs presented are derived according to the methodology presented here. All cost estimates are
conceptual, and are expressed in 2012 dollars (Engineering News Record 20-Cities Average Construction
Cost Index = 10285.30 Los Angeles May 2012) rounded to the nearest thousand dollars, with no
allowance for inflation or financing costs.
Capital cost estimates were prepared to provide comparative order of magnitude costs for new or
expanded construction of unit processes considered necessary for the RWCWRF under the options
identified in the Wastewater Management Plan. These conceptual estimates, summarized in the table
below, were prepared in accordance with the guidelines of the Association for the Advancement of Cost
Engineering International (AACEI). According to AACEI, a Class 3 estimate is defined as follows:
“Class 3 estimates are generally prepared to form the basis for budget authorization, appropriation,
and/or funding. Class 3 estimates are typically prepared to support full project funding requests, and
become the first of the project phase “control estimate” against which all actual costs and resources will
be monitored for variations to the budget. They are used as the project budget until replaced by more
detailed estimates. In many owner organizations, a Class 3 estimate may be the last estimate required
and could well form the only basis for cost/schedule control. Typical level of project definition required:
10% to 40% of full project definition.”
Recognizing the conceptual level of development undertaken to define the alternatives identified
herein, it can reasonably be estimated that a 10% to 20% project definition can be assigned to the
RWCWRF assessment. Given this level of project definition and using a Class 1 (final engineering)
estimate accuracy for municipal wastewater treatment facilities of +5% / -3%, AACEI standards project
that a Class 3 estimate would fall within an accuracy range of approximately +25% / - 15%. General
contingencies were applied to each unit process estimates. It is therefore considered reasonable that
actual capital costs for the unit processes identified may be expected to be between 15% higher to 10%
lower than the conceptual estimates presented herein. These percentages should be viewed as
statistical confidence limits, and not associated with additional project contingencies.
The probable construction cost pricing for each unit process area identified herein includes the following
within the cost line items presented:
General Conditions Subcontracted Specialty Trades
Supervision Freight and delivery charges
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 4
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Project Management Labor
Bonds Materials
Insurance Equipment
Sales taxes Overhead & Profit
Temporary facilities including utilities (power, water, and communications), field
offices, storage, small tools, safety program and equipment, vehicles, fuel, and other
support items required by the onsite prime/general contractor.
A budget for interconnecting yard piping and yard electrical, miscellaneous site improvements and
restoration of the general work areas (landscaping, irrigation, paving, sidewalks, etc.) is also included.
The cost estimates shown are related only to costs that would be included in a general contractor’s bid
for related construction work and does not include other costs such as District administration,
engineering, third party construction management, environmental documentation, etc. Costs identified
have been prepared for guidance in project evaluation and implementation from the information
available at the time of the estimate. The final costs of the project will depend on the type of project
delivery selected by the District, actual labor and material costs, competitive market conditions, actual
site conditions, final project scope, implementation schedule, and other factors. As a result, the final
project costs will vary from estimates presented here. Because of these factors, funding needs must be
carefully reviewed prior to making specific financial decisions or establishing project budgets to help
ensure project evaluation and adequate funding.
A summary of the conceptual capital costs presented herein is provided in the following table.
Summary of Conceptual Capital Costs for Assessment Options A, B and C
Process Option A – 1.3 MGD Option B – 2.6 MGD Option C – 3.9 MGD
Influent Pump Station $0 $1,131,928 $1,293,335
Headworks & Grit Removal 0 2,043,111 2,195,870
Aeration Basins 0 3,332,990 5,897,031
Secondary Clarifiers 0 1,964,010 3,581,601
RAS/WAS Pump Station 0 820,187 1,490,724
Scum Pump Station 0 173,323 173,323
Effluent Pump Station 0 788,179 1,542,203
Administration Building 0 0 1,039,893
Blower & Electrical Building 0 2,052,257 2,487,873
Aerobic Digestion 1,461,547 2,759,576 3,936,060
Digested Sludge Pump Station 121,111 229,215 331,281
WAS Thickening 847,504 1,578,858 2,309,062
Sludge Dewatering Centrifuge 915,458 915,458 1,747,885
Tertiary Filters (includes flocculation) 0 648,138 1,296,276
NaOCl Storage, Pumping and
Chlorine Contact Tank 0 2,012,465 2,201,274
Total $3,345,620 $20,449,695 $31,523,691
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 5
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Option D as identified in the Wastewater Management Plan establishes requirements for estimate of
costs associated with the abandonment, decommissioning, demolition and site restoration of the
RWCWRF and SBPS. The following table presents a summary of costs for Option D.
Summary of Decommissioning and Demolition Costs of RWCWRF and SBPS
Decommissioning $492,000
Demolition/Restoration $3,463,800
Grand Total $3,955,800
Additional annual power costs associated with the options identified by ARCADIS are presented in Part B
of the technical memorandum. The summary of additional power costs above existing operations at 1.3
MGD ADWF is as follows:
Summary of Additional Annual Power Costs
Option A Solids Handling Facilities @ 1.3 MG ADF $56,168
Option B – Expansion to 2.6 MGD ADF $581,499
Option C – Expansion to 3.9 MGD ADF $1,275,534
Additional annual chemical costs associated with the options identified by ARCADIS are presented in
Part C of the technical memorandum. The summary of additional chemical costs above existing
operations at 1.3 MGD ADWF is as follows:
Summary of Additional Annual Chemical Costs
Option A Solids Handling Facilities @ 1.3 MG ADF $42,359
Option B – Expansion to 2.6 MGD ADF $115,665
Option C – Expansion to 3.9 MGD ADF $204,158
Some of the estimates presented herein for each unit process consider an economy of scale in assessing
unit costs for areas such as equipment, ancillary support facilities, labor, concrete (common wall),
electrical/I&C related systems, common excavation, general conditions, etc.
This technical memorandum identifies basic conceptual flow design assumptions and criteria for sizing
of unit processing and determining scope of improvements associated with the capital improvements
for the options assessed. The assumptions and criteria are not intended to be exhaustive relative to
parameters that would be used to establish detailed design, rather it is meant only to provide a high
level basis for sizing under each option.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 6
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Part A – Estimate of Conceptual Capital Costs
1. INFLUENT PUMP STATION SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR
VARIOUS TREATMENT PLANT CAPACITIES
1.1. 1.3 MGD PLANT CAPACITY – OPTION A
1.1.1. SIZING CRITERIA - AVERAGE FLOW: 1.3 MGD
No Influent Pump Station improvements are required for Option A. The existing facility remains in
operation in its current size and condition.
1.2. 2.6 MGD PLANT CAPACITY – OPTION B
1.2.1. SIZING CRITERIA - AVERAGE FLOW: 2.6 MGD
1.2.2. INFLUENT PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Abandon existing pump station and construct new 2.6 MGD pump station
• Assume 1 reinforced concrete pump station with wetwell inside dimensions of 61’ L x
10’W x 23’ SWD.
• Assume 3 submersible pumps (2 operating, 1 standby) complete with quick-release
coupling and cable rail removal system.
• Assume 8” pump discharge piping into a 12” and 14” discharge manifold complete with
piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
1.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
INFLUENT PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price Total Price
General Conditions Approx.15% of Total LS 1 147,680 147,680
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 8,600 7 60,200
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 77,280 77,280
Structural (Reinforced Concrete)
IPS SOG 15'x70'x1.5' CY 62 597 37,014
IPS Walls (Lower Half) 152'x13'x1.5' CY 116 854 99,064
IPS Walls (Upper Half) 152'x10'x1.5 CY 89 705 62,745
IPS Deck & Beams 66'x12'x1' CY 32 1,406 44,992
IPS Mechanical Area SOG 9'x68'x1' CY 24 468 11,232
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 7
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 2,500 2,500
Structural (Misc. Metals)
Aluminum Access Hatches
Est. Labor + Supplier
Pricing EA 3 3,390 10,170
Hose Racks
Est. Labor + Supplier
Pricing EA 2 200 400
Mechanical
Submersible Pumps, Bases & Guide Rails
Est. Labor + Supplier
Pricing EA 3 52,828 158,484
Process Piping, Valves & Supports
Est. Labor + Supplier
Pricing LS 1 93,495 93,495
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 160,279 160,279
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 7,500 7,500
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 11,250 11,250
Subtotal
984,285
Contingencies @ 15%
147,643
Total
1,131,928
Total Option B relative estimate of probable construction costs = $1,131,928
1.3. 3.9 MGD PLANT CAPACITY – OPTION C
1.3.1. SIZING CRITERIA - AVERAGE FLOW: 3.9 MGD
1.3.2. INFLUENT PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Abandon existing pump station and construct new 3.9 MGD pump station
• Assume 1 reinforced concrete pump station expansion with wetwell inside dimensions of
61’ L x 15’W x 23’ SWD.
• Assume 3 submersible pumps (2 operating, 1 standby) complete with quick-release
coupling and cable rail removal system.
• Assume 8”-10” pump discharge piping into a 14” and 16” discharge manifold complete
with piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
1.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 8
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
INFLUENT PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 147,680 147,680
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 9,600 7 67,200
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 77,280 77,280
Structural (Reinforced Concrete)
IPS SOG 22'x70'x1.5' CY 90 597 53,730
IPS Walls (Lower Half) 162'x13'x1.5' CY 123 854 105,042
IPS Walls (Upper Half) 162'x10'x1.5 CY 96 705 67,680
IPS Deck & Beams 66'x12'x1' CY 32 1,406 44,992
IPS Mechanical Area SOG 9'x68'x1' CY 24 468 11,232
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 2,500 2,500
Structural (Misc. Metals)
Aluminum Access Hatches Est. Labor + Supplier Pricing EA 3 3,390 10,170
Hose Racks Est. Labor + Supplier Pricing EA 2 200 400
Mechanical
Submersible Pumps, Bases & Guide Rails Est. Labor + Supplier Pricing EA 3 72,828 218,484
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 103,495 103,495
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 196,004 196,004
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 7,500 7,500
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 11,250 11,250
Subtotal
1,124,639
Contingencies @ 15%
168,696
Total
1,293,335
Total Option C relative estimate of probable construction costs = $1,293,335
1.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR
INFLUENT PUMP STATION
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD No Improvements Required
2.6 MGD $1,131,928
3.9 MGD $1,293,335
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 9
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
2. HEADWORKS AND GRIT REMOVAL SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR
VARIOUS TREATMENT PLANT CAPACITIES
2.1. 1.3 MGD PLANT CAPACITY – OPTION A
2.1.1. SIZING CRITERIA - AVERAGE FLOW: 1.3 MGD
No Headworks and Grit Removal improvements are required for Option A. The existing facility remains
in operation in its current size and condition.
2.2. 2.6 MGD PLANT CAPACITY – OPTION B
2.2.1. SIZING CRITERIA - AVERAGE FLOW: 2.6 MGD
2.2.2. HEADWORKS AND GRIT REMOVAL PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete structure with overall dimensions of 55’-4” L x 18’W x 11’ D
including parallel 4’ channels, two 8’ diameter grit collection tanks, and 1 grit dewatering
equipment pad.
• Assume 1 mechanical climber screen and 1 manual bar rack screen in parallel channels.
• Assume 1 screenings screw conveyor with discharge chute.
• Assume 2 grit removal systems including grit pumps and grit dewatering cyclones.
• Assume 4 slide gates for parallel channel flow control.
• Assume 4”-8” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
2.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
HEADWORKS & GRIT REMOVAL – PROBABLE CONSTRUCTION COSTS
Description Dimensions / Notes Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 276,616 276,616
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 800 9 7,200
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 112,250 112,250
Structural (Reinforced Concrete)
Grit Tank Sump SOG 14' Diam x 1' (2 Each) CY 18 481 8,658
Grit Tank Sump Walls 6' Diam x 6' x 1' (2 Each) CY 10 1,144 11,440
Grit Tank Main Body Slab 10' Diam x 1' (2 Each) CY 10 766 7,660
Grit Tank Main Body Walls 9' Diam x 12.5' x 1' (2 Each) CY 32 1,280 40,960
Grit Tank Main Body Deck 12' Diam x 1' (2 Each) CY 10 1,237 12,370
Headworks SOG (Section 1) 58' x 11' x 8" CY 18 554 9,972
Headworks SOG (Section 2) 58' x 11' x 8" CY 18 554 9,972
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 10
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Headworks Walls (Section 1) 92' x 11' x 1' CY 40 1,115 44,600
Headworks Walls (Section 2) 92' x 11' x 1' CY 40 1,115 44,600
Headworks Deck (Partial) 120 SF x 8" CY 4 1,721 6,884
Grit Cyclone SOG 14' x 28' x 1' (2 Each) CY 30 667 20,010
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 3,000 3,000
Structural (Misc. Metals)
Aluminum Checker Plate Est. Labor + Supplier Pricing SF 127 60 7,620
Manual Bar Rack & Supports Est. Labor + Supplier Pricing EA 1 32,075 32,075
Aluminum Access Hatches Est. Labor + Supplier Pricing EA 2 1,365 2,730
Hose Racks Est. Labor + Supplier Pricing EA 2 200 400
Mechanical
Mechanical Bar/Climber Screen Equipment Est. Labor + Supplier Pricing EA 1 130,605 130,605
Screw Conveyor & Discharge Chute Est. Labor + Supplier Pricing EA 1 129,330 129,330
Grit Pump Est. Labor + Supplier Pricing EA 2 77,183 154,366
Grit Dewatering Cyclone Est. Labor + Supplier Pricing EA 2 107,468 214,936
Aluminum Slide Gates, Frames & Operators Est. Labor + Supplier Pricing EA 4 15,592 62,368
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 78,653 78,653
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 249,900 301,843
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 18,000 18,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 27,500 27,500
Subtotal
1,776,618
Contingencies @ 15%
266,493
Total
2,043,111
Total Option B relative estimate of probable construction costs = $2,043,111
2.3. 3.9 MGD PLANT CAPACITY – OPTION C
2.3.1. SIZING CRITERIA - AVERAGE FLOW: 3.9 MGD
2.3.2. HEADWORKS AND GRIT REMOVAL PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete structure with overall dimensions of 55’-4” L x 18’W x 11’ D
including parallel 5’ channels, two 10’ diameter grit collection tanks, and 1 grit dewatering
equipment pad.
• Assume 1 mechanical climber screen and 1 manual bar rack screen in parallel channels.
• Assume 1 screenings screw conveyor with discharge chute.
• Assume 2 grit removal systems including grit pumps and grit dewatering cyclones.
• Assume 4 slide gates for parallel channel flow control.
• Assume 4”-8” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 11
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
2.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
HEADWORKS & GRIT REMOVAL – PROBABLE CONSTRUCTION COSTS
Description Dimensions / Notes Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 276,616 276,616
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 1,500 9 13,500
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 112,250 112,250
Structural (Reinforced Concrete)
Grit Tank Sump SOG 16' Diam x 1' (2 Each) CY 24 481 11,544
Grit Tank Sump Walls 8' Diam x 6' x 1' (2 Each) CY 14 1,144 16,016
Grit Tank Main Body Slab 12' Diam x 1' (2 Each) CY 14 766 10,724
Grit Tank Main Body Walls
11' Diam x 12.5' x 1' (2
Each) CY 36 1,280 46,080
Grit Tank Main Body Deck 12' Diam x 1' (2 Each) CY 14 1,237 17,318
Headworks SOG (Section 1) 58' x 14' x 8" CY 23 554 12,742
Headworks SOG (Section 2) 58' x 14' x 8" CY 23 554 12,742
Headworks Walls (Section 1) 92' x 14' x 1' CY 45 1,115 50,175
Headworks Walls (Section 2) 92' x 14' x 1' CY 45 1,115 50,175
Headworks Deck (Partial) 120 SF x 8" CY 4 1,721 6,884
Grit Cyclone SOG 14' x 28' x 1' (2 Each) CY 30 667 20,010
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 3,000 3,000
Structural (Misc. Metals)
Aluminum Checker Plate Est. Labor + Supplier Pricing SF 160 60 9,600
Manual Bar Rack & Supports Est. Labor + Supplier Pricing EA 1 42,075 42,075
Aluminum Access Hatches Est. Labor + Supplier Pricing EA 2 2,500 5,000
Hose Racks Est. Labor + Supplier Pricing EA 2 200 400
Mechanical
Mechanical Bar/Climber Screen Equipment Est. Labor + Supplier Pricing EA 1 175,605 175,605
Screw Conveyor & Discharge Chute Est. Labor + Supplier Pricing EA 1 159,330 159,330
Grit Pump Est. Labor + Supplier Pricing EA 2 77,183 154,366
Grit Dewatering Cyclone Est. Labor + Supplier Pricing EA 2 107,468 214,936
Aluminum Slide Gates, Frames & Operators Est. Labor + Supplier Pricing EA 4 15,592 62,368
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 78,653 78,653
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 343,701 301,843
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 12
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 18,000 18,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 27,500 27,500
Subtotal
1,909,452
Contingencies @ 15%
286,418
Total
2,195,870
Total Option C relative estimate of probable construction costs = $2,195,870
2.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR
HEADWORKS AND GRIT REMOVAL
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD No Improvements Required
2.6 MGD $2,043,111
3.9 MGD $2,195,870
3. AERATION BASIN SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR VARIOUS
TREATMENT PLANT CAPACITIES
3.1. 1.3 MGD PLANT CAPACITY – OPTION A
3.1.1. SIZING CRITERIA - AVERAGE FLOW: 1.3 MGD
No Aeration Basin improvements are required for Option A. The existing facility remains in operation in
its current size and condition.
3.2. 2.6 MGD PLANT CAPACITY – OPTION B
3.2.1. SIZING CRITERIA - AVERAGE FLOW: 2.6 MGD
3.2.2. AERATION BASINS PRELIMINARY DESIGN ASSUMPTIONS
• Assume 2 reinforced concrete structures with total overall dimensions of 152’-4” L x 83’-6
W x 18’ D (inside dimensions of 150’ L x 30’ W x 18’ D each basin) including interior zone
dividing walls, influent and effluent channels, and access walkways.
• Assume 4 portable submersible mixers for use in the preanoxic and postanoxic zones (16
locations prepared with supports and mounting hardware).
• Assume fine bubble aeration equipment including headers, diffusers and valving in both
basins.
• Assume sluice gates and slide gates for influent and effluent channel flow control.
• Assume 8”-16” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
3.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 13
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
AERATION BASINS – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 455,620 455,620
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 2,800 9 25,200
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 225,926 225,926
Structural (Reinforced Concrete)
18" Slab On Grade (Center Section 1-4) 15.5' x 25' x 1.5' (4 Each) CY 90 551 49,590
18" Slab On Grade (Section 5-6) 15.5' x 27.17' x 1.5' (2 Each) CY 50 509 25,450
18" Slab On Grade (Outer Section 1-8) 25' x 25' x 1.5' (8 Each) CY 292 495 144,540
18" Slab On Grade (Outer Section 9-12) 25' x 27.17' x 1.5' (4 Each) CY 159 449 71,391
Walls - 18' Center Dividing (Section 1-6) 181' x 18' x1.17' CY 152 927 140,904
Walls - 18' Exterior (Section 1-8) 300' x 18' x 1.17' CY 245 927 227,115
Walls - 18' Exterior (Section 9-12) 110' x 18' x 1.17' CY 90 920 82,800
Walls - 15' Interior Zones (Section 1-4) 96' x 15' x 1' CY 56 1,074 60,144
Center Walkway (Section 1-6) 173' x 4' x 6" CY 17 2,115 35,955
Exterior Walkways (Section 1-8) 250' x 4' x 6" CY 25 2,175 54,375
Infl Inlet Box Ftg & Support Wall 16.5' x 9' x 1' CY 6 1,240 7,440
Infl Inlet Box Deck Slab (Section 1) 14' x 16' x 1' CY 9 1,365 12,285
Infl Inlet Box Walls (Section 1) 36' x 9' x 1' CY 13 1,053 13,689
Influent Channel Deck Slab 64' x 5' x 6" CY 13 1,374 17,862
Influent Channel Walls 74' x 9' x 1' CY 26 1,045 27,170
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 5,000 5,000
Structural (Misc. Metals)
Checker Plate Est. Labor + Supplier Pricing SF 380 42 15,960
Stairs Est. Labor + Supplier Pricing EA 1 5,940 5,940
Handrails Est. Labor + Supplier Pricing LF 1,030 55 56,650
Precast Vault & Hatch Est. Labor + Supplier Pricing EA 1 6,960 6,960
Hose Racks Est. Labor + Supplier Pricing EA 6 270 1,620
87,130
Mechanical
Submersible Mixers Est. Labor + Supplier Pricing EA 4 31,448 125,792
MLSS Return Pumps & Piping Est. Labor + Supplier Pricing EA 2 50,000 100,000
Fine Bubble Aeration Equipment Est. Labor + Supplier Pricing EA 2 81,192 162,384
C.I. Sluice Gates, Frames & Operators Est. Labor + Supplier Pricing EA 2 6,990 13,980
Aluminum Slide Gates, Frames & Operators Est. Labor + Supplier Pricing EA 2 6,825 13,650
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 170,154 170,154
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 497,250 497,250
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 31,500 31,500
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 14
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 27,000 27,000
Subtotal
2,911,296
Contingencies @ 15%
421,694
Total
3,332,990
Total Option B relative estimate of probable construction costs = $3,332,990
3.3. 3.9 MGD PLANT CAPACITY – OPTION C
3.3.1. SIZING CRITERIA - AVERAGE FLOW: 3.9 MGD
3.3.2. AERATION BASINS PRELIMINARY DESIGN ASSUMPTIONS
• Assume 4 reinforced concrete structures with total overall dimensions of 152’-4” L x 83’-6
W x 18’ D (inside dimensions of 150’ L x 30’ W x 18’ D each basin) including interior zone
dividing walls, influent and effluent channels, and access walkways.
• Assume 8 portable submersible mixers for use in the preanoxic and postanoxic zones (32
locations prepared with supports and mounting hardware).
• Assume 4 MLSS Return Pumps, 1 per aeration pass
• Assume fine bubble aeration equipment including headers, diffusers and valving in both
basins.
• Assume sluice gates and slide gates for influent and effluent channel flow control.
• Assume 8”-16” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
3.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
AERATION BASINS – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price Total Price
General Conditions Approx. 15% of Total LS 1 455,620 455,620
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 5,600 9 50,400
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 305,000 305,000
Structural (Reinforced Concrete)
18" Slab On Grade (Center Section 1-4) 15.5' x 25' x 1.5' (8 Each) CY 180 551 99,180
18" Slab On Grade (Section 5-6) 15.5' x 27.17' x 1.5' (4 Each) CY 100 509 50,900
18" Slab On Grade (Outer Section 1-8) 25' x 25' x 1.5' (16 Each) CY 584 495 289,080
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 15
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
18" Slab On Grade (Outer Section 9-12) 25' x 27.17' x 1.5' (8 Each) CY 318 449 142,782
Walls - 18' Center Dividing (Section 1-6) 181' x 18' x1.17' (2 Each) CY 304 927 281,808
Walls - 18' Exterior (Section 1-8) 300' x 18' x 1.17' (2 Each) CY 490 927 454,230
Walls - 18' Exterior (Section 9-12) 110' x 18' x 1.17' (2 Each) CY 180 920 165,600
Walls - 15' Interior Zones (Section 1-4) 96' x 15' x 1' (2 Each) CY 112 1,074 120,288
Center Walkway (Section 1-6) 173' x 4' x 6" (2 Each) CY 34 2,115 71,910
Exterior Walkways (Section 1-8) 250' x 4' x 6" (2 Each) CY 50 2,175 108,750
Infl Inlet Box Ftg & Support Wall 16.5' x 9' x 1' (2 Each) CY 12 1,240 14,880
Infl Inlet Box Deck Slab (Section 1) 14' x 16' x 1' (2 Each) CY 18 1,365 24,570
Infl Inlet Box Walls (Section 1) 36' x 9' x 1' (2 Each) CY 26 1,053 27,378
Influent Channel Deck Slab 64' x 5' x 6" (2 Each) CY 26 1,374 35,724
Influent Channel Walls 74' x 9' x 1' (2 Each) CY 52 1,045 54,340
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 10,000 10,000
Structural (Misc. Metals)
Checker Plate Est. Labor + Supplier Pricing SF 720 42 30,240
Stairs Est. Labor + Supplier Pricing EA 2 5,940 11,880
Handrails Est. Labor + Supplier Pricing LF 2,060 55 113,300
Precast Vault & Hatch Est. Labor + Supplier Pricing EA 2 6,960 13,920
Hose Racks Est. Labor + Supplier Pricing EA 12 270 3,240
Mechanical
Submersible Mixers Est. Labor + Supplier Pricing EA 8 31,448 251,584
MLSS Return Pumps & Piping Est. Labor + Supplier Pricing EA 4 50,000 200,000
Fine Bubble Aeration Equipment Est. Labor + Supplier Pricing EA 4 81,192 324,768
C.I. Sluice Gates, Frames & Operators Est. Labor + Supplier Pricing EA 4 6,990 27,960
Aluminum Slide Gates, Frames &
Operators Est. Labor + Supplier Pricing EA 4 6,825 27,300
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 2 170,154 340,308
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 2 465,000 930,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 2 31,500 63,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 2 27,000 54,000
Subtotal
5,153,940
Contingencies @ 15%
743,091
Total
5,897,031
Total Option C relative estimate of probable construction costs = $5,897,031
3.4. ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR AERATION
BASINS
Plant Capacity Estimate of Probable Construction Costs**
1.3 MGD No Improvements Required
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 16
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
2.6 MGD $3,332,990
3.9 MGD $5,897,031
4. SECONDARY CLARIFIERS SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR VARIOUS
TREATMENT PLANT CAPACITIES
4.1. 1.3 MGD PLANT CAPACITY – OPTION A
4.1.1. SIZING CRITERIA - AVERAGE FLOW: 1.3 MGD
No Secondary Clarifier improvements are required for Option A. The existing facility remains in
operation in its current size and condition.
4.2. 2.6 MGD PLANT CAPACITY – OPTION B
4.2.1. SIZING CRITERIA - AVERAGE FLOW: 2.6 MGD
4.2.2. SECONDARY CLARIFIERS PRELIMINARY DESIGN ASSUMPTIONS
• Assume 2 reinforced concrete structures with total overall dimensions of 96’-5” L x 43’-6
W x 15’ D (inside dimensions of 94’ L x 20’ W x 15’ D each basin) including influent and
effluent channels, hoppers and access walkways.
• Assume chain and flight sludge collection equipment in each basin.
• Assume rotating scum collection equipment in each basin.
• Assume FRL launders, weirs and supports in the effluent end of each basin.
• Assume slide gates for influent and effluent channel flow control.
• Assume 6”-8” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
4.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
SECONDARY CLARIFIERS – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 265,300 265,300
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 1,520 9 13,680
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 141,230 141,230
Structural (Reinforced Concrete)
Sludge Hopper SOG (Section 1) 6' x 11' x 1' CY 4 759 3,036
Sludge Hopper SOG (Section 2) 11' x 20' x 1.5' (2 Each) CY 26 536 13,936
Center Div. Wall SOG (Section 1-4) 6' x 21.6' x 1.5' (4 each) CY 31 698 21,638
Main Slab On Grade (Section 1-8) 20' x 21.6' x 1.5' (8 Each) CY 202 491 99,182
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 17
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Walls- Interior Div. (Section 1) 16' x 20' x 1.5' CY 18 854 15,372
Walls- Interior Div. (Section 2-5) 93' x 15' x 1.17' CY 64 939 60,096
Walls - Exterior (Section 1-2) 62' x 20' x 1.17' CY 57 942 53,694
Walls - Exterior (Section 3-10) 216' x 15' x 1.17' CY 146 933 136,218
Deck - Infl Channel Invert (Section 1-3) 43.5' x 5' x 1' CY 9 1,198 10,782
Walls - Infl Channel (Section 1-3) 54' x 6' x 1' CY 13 1,168 15,184
Deck - Effl Channel Invert (Section 1-3) 43.5' x 5' x 1' CY 9 1,198 10,782
Walls - Effl Channel (Section 1-3) 54' x 8' x 1' CY 17 1,153 19,601
Center Walkway (Section 1-5) 97' x 5' x 6" CY 12 2,097 25,164
Effl Drop Box Slab at Effl Channel 5' x 5' CY 2 979 1,958
Effl Drop Box Walls at Effl Channel 20' x 6' x 1' CY 5 1,143 5,715
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 5,000 5,000
Structural (Misc. Metals)
Aluminum Grating Est. Labor + Supplier Pricing SF 328 51 16,728
Stairs Est. Labor + Supplier Pricing EA 1 6,645 6,645
Handrails Est. Labor + Supplier Pricing LF 530 55 29,150
Hose Racks Est. Labor + Supplier Pricing EA 6 270 1,620
Mechanical
Sludge Collection Equipment Est. Labor + Supplier Pricing EA 2 88,222 176,444
Rotating Scum Troughs Est. Labor + Supplier Pricing EA 2 20,700 41,400
Aluminum Slide Gates, Frames & Operators Est. Labor + Supplier Pricing EA 8 10,425 83,400
FRP Weirs, Launders & Supports Est. Labor + Supplier Pricing EA 4 18,630 74,520
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 15,360 15,360
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 301,500 301,500
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 21,000 21,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 22,500 22,500
Subtotal
1,707,835
Contingencies @ 15%
256,175
Total
1,964,010
Total Option B relative estimate of probable construction costs = $1,964,010
4.3. 3.9 MGD PLANT CAPACITY – OPTION C
4.3.1. SIZING CRITERIA - AVERAGE FLOW: 3.9 MGD
4.3.2. SECONDARY CLARIFIERS PRELIMINARY DESIGN ASSUMPTIONS
• Assume 4 reinforced concrete structures with total overall dimensions of 96’-5” L x 43’-6
W x 15’ D (inside dimensions of 94’ L x 20’ W x 15’ D each basin) including influent and
effluent channels, hoppers and access walkways.
• Assume chain and flight sludge collection equipment in each basin.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 18
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Assume rotating scum collection equipment in each basin.
• Assume FRL launders, weirs and supports in the effluent end of each basin.
• Assume slide gates for influent and effluent channel flow control.
• Assume 6”-8” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
4.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
SECONDARY CLARIFIERS – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 265,300 265,300
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 3,040 9 27,360
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 2 141,230 282,460
Structural (Reinforced Concrete)
Sludge Hopper SOG (Section 1) 6' x 11' x 1' (2 Each) CY 8 759 6,072
Sludge Hopper SOG (Section 2) 11' x 20' x 1.5' (4 Each) CY 52 536 27,872
Center Div. Wall SOG (Section 1-4) 6' x 21.6' x 1.5' (8 each) CY 62 698 43,276
Main Slab On Grade (Section 1-8) 20' x 21.6' x 1.5' (16 Each) CY 404 491 198,364
Walls- Interior Div. (Section 1) 16' x 20' x 1.5' (2 Each) CY 36 854 30,744
Walls- Interior Div. (Section 2-5) 93' x 15' x 1.17' (2 Each) CY 128 939 120,192
Walls - Exterior (Section 1-2) 62' x 20' x 1.17' (2 Each) CY 114 942 107,388
Walls - Exterior (Section 3-10) 216' x 15' x 1.17' (2 Each) CY 292 933 272,436
Deck - Infl Channel Invert (Section 1-3) 43.5' x 5' x 1' (2 Each) CY 18 1,198 21,564
Walls - Infl Channel (Section 1-3) 54' x 6' x 1' (2 each) CY 26 1,168 30,368
Deck - Effl Channel Invert (Section 1-3) 43.5' x 5' x 1' (2 Each) CY 18 1,198 21,564
Walls - Effl Channel (Section 1-3) 54' x 8' x 1' (2 Each) CY 34 1,153 39,202
Center Walkway (Section 1-5) 97' x 5' x 6" (2 Each) CY 24 2,097 50,328
Effl Drop Box Slab at Effl Channel 5' x 5' (2 Each) CY 4 979 3,916
Effl Drop Box Walls at Effl Channel 20' x 6' x 1' (2 each) CY 10 1,143 11,430
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 2 5,000 10,000
Structural (Misc. Metals)
Aluminum Grating Est. Labor + Supplier Pricing SF 656 51 33,456
Stairs Est. Labor + Supplier Pricing EA 2 6,645 13,290
Handrails Est. Labor + Supplier Pricing LF 1,060 55 58,300
Hose Racks Est. Labor + Supplier Pricing EA 12 270 3,240
Mechanical
Sludge Collection Equipment Est. Labor + Supplier Pricing EA 4 88,222 352,888
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 19
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Rotating Scum Troughs Est. Labor + Supplier Pricing EA 4 20,700 82,800
Aluminum Slide Gates, Frames & Operators Est. Labor + Supplier Pricing EA 16 10,425 166,800
FRP Weirs, Launders & Supports Est. Labor + Supplier Pricing EA 8 18,630 149,040
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 2 15,360 30,720
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 2 283,533 567,066
Testing, Start-Up & Commissioning Average 1.25% of Total LS 2 21,000 42,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 2 22,500 45,000
Subtotal
3,114,436
Contingencies @ 15%
467,165
Total
3,581,601
Total Option C relative estimate of probable construction cost = $3,581,601
4.4. ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR SECONDARY
CLARIFIERS
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD No Improvements Required
2.6 MGD $1,964,010
3.9 MGD $3,581,601
5. RAS/WAS PUMP STATION SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR
VARIOUS TREATMENT PLANT CAPACITIES
5.1. 1.3 MGD PLANT CAPACITY – OPTION A
5.1.1. SIZING CRITERIA - AVERAGE FLOW: 1.3 MGD
No RAS/WAS Pump Station improvements are required for Option A. The existing facility remains in
operation in its current size and condition.
5.2. 2.6 MGD PLANT CAPACITY – OPTION B
5.2.1. SIZING CRITERIA - AVERAGE FLOW: 2.6 MGD
5.2.2. RAS/WAS PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete dry-pit pump station structure with inside dimensions of 41-
2” L x 26’-10” W x 20’ D including stairs and pump foundations.
• Assume 3 horizontal centrifugal or progressive cavity skid-mounted RAS pumps & motors.
• Assume 2 horizontal centrifugal or progressive cavity skid-mounted WAS pumps & motors.
• Assume 1 duplex submersible drain pump system.
• Assume 4”-12” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 20
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
5.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
RAS/WAS PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 110,530 110,530
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 600 9 5,400
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 63,434 63,434
Structural (Reinforced Concrete)
RAS/WAS 18" SOG (Section 1-4) 16.25' x 23' x 1.5' (4 Each) CY 88 544 47,872
RAS/WAS Exterior Walls (Section 1-2) 104' x 20' x 1.17' CY 95 1,160 110,200
Structural (Misc. Metals)
Aluminum Grating Est. Labor + Supplier Pricing SF 50 49 2,450
Stairs Est. Labor + Supplier Pricing EA 1 14,760 14,760
Handrails Est. Labor + Supplier Pricing LF 80 55 4,400
Hose Racks Est. Labor + Supplier Pricing EA 2 270 540
Mechanical
RAS Pumps & Motors Est. Labor + Supplier Pricing EA 3 16,710 50,130
WAS Pumps & Motors Est. Labor + Supplier Pricing EA 2 12,810 25,620
Drain Submersible Duplex Pump Est. Labor + Supplier Pricing EA 1 7,470 7,470
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 128,100 128,100
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 124,800 124,800
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 10,000 10,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 7,500 7,500
Subtotal
713,206
Contingencies @ 15%
106,981
Total
820,187
Total Option B relative estimate of probable construction costs = $820,187
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 21
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
5.3. 3.9 MGD PLANT CAPACITY – OPTION C
5.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
5.3.2. RAS/WAS PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete dry-pit pump station structure with inside dimensions of 82-
4” L x 26’-10” W x 20’ D including stairs and pump foundations.
• Assume 6 horizontal centrifugal or progressive cavity skid-mounted RAS pumps & motors.
• Assume 4 horizontal centrifugal or progressive cavity skid-mounted WAS pumps & motors.
• Assume 2 duplex submersible drain pump system.
• Assume 4”-12” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
5.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
RAS/WAS PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 110,530 110,530
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 1,200 9 10,800
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 2 63,434 126,868
Structural (Reinforced Concrete)
RAS/WAS 18" SOG (Section 1-4) 16.25' x 23' x 1.5' (8 Each) CY 176 544 95,744
RAS/WAS Exterior Walls (Section 1-2) 104' x 20' x 1.17' (2 Each) CY 190 1,160 220,400
Structural (Misc. Metals)
Aluminum Grating Est. Labor + Supplier Pricing SF 100 49 4,900
Stairs Est. Labor + Supplier Pricing EA 2 14,760 29,520
Handrails Est. Labor + Supplier Pricing LF 160 55 8,800
Hose Racks Est. Labor + Supplier Pricing EA 4 270 1,080
Mechanical
RAS Pumps & Motors Est. Labor + Supplier Pricing EA 6 16,710 100,260
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 22
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
WAS Pumps & Motors Est. Labor + Supplier Pricing EA 4 12,810 51,240
Drain Submersible Duplex Pump Est. Labor + Supplier Pricing EA 2 7,470 14,940
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 2 128,100 256,200
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 2 115,000 230,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 2 10,000 20,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 2 7,500 15,000
Subtotal
1,296,282
Contingencies @ 15%
194,442
Total
1,490,724
Total Option C relative estimate of probable construction cost = $1,490,724
5.3.4. ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR RAS/WAS
PUMP STATION
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD No Improvement Required
2.6 MGD $820,187
3.9 MGD $1,490,724
6. AEROBIC DIGESTION SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR VARIOUS
TREATMENT PLANT CAPACITIES
6.1. MGD PLANT CAPACITY – OPTION A
6.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
• Thickened WAS (TWAS) production at 1.3 MGD Capacity
• Reference JSME November 12, 1989 Preliminary Design Submittal for Jamacha Basin
Water Reclamation Facility Upgrade and Expansion Project
• Pounds TWAS total solids per day = 2,730 lbs TSS/day
• Gallons per day (assume TWAS @ 4.0% TSS) = 8,100 GPD
• Aerobic Digester Capacity
• Detention time @ 40 days to meet “Class B” requirements
• Digester volume required for 40 day detention time is 324,000 active gallons (43,300 cu.
Ft.)
6.1.2. AEROBIC DIGESTER PRELIMINARY DESIGN ASSUMPTIONS
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 23
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Assume 1 reinforced concrete structures with total overall dimensions of 152’ L x 23-6” W
x 18’ D (divided into 3 tanks with inside dimensions of 49’-4” L x 19-6’ W x 15’SWD)
including access walkways (T-walkways).
• Assume 1 reinforced concrete pad for digester aeration air blowers.
• Assume coarse bubble aeration equipment in each of the three tanks.
• Assume 2 positive displace blowers (1operational, 1 standby)
• Assume 1 telescoping valve in each of the three tanks.
• Assume 4”-16” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
6.1.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 1.3 MGD (approximate) water reclamation facility within the State
of California.
AEROBIC DIGESTER – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 183,033 183,033
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 1,500 9 13,500
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 87,250 87,250
Structural (Reinforced Concrete)
18" SOG (Section 1-4) 25' x 27.17' x 1.5' (4 Each) CY 159 564 89,676
18" SOG (Section 5-6) 27' x 27.17' x 1.5' (2 Each) CY 85 443 37,655
Walls - Exterior (Section 1-6) 207' x 18' x 1.17' CY 170 922 156,740
Walls - Exterior (Section 3-5) 55' x 18' x 1.17' CY 45 922 41,490
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 4,000 4,000
PD Blower SOG 25' x 25' x 1.5' (1 Each) CY 37 443 16,391
Structural (Misc. Metals)
Handrails Est. Labor + Supplier Pricing LF 120 55 6,600
Hose Racks Est. Labor + Supplier Pricing EA 4 300 1,200
Mechanical
Telescoping Valves Est. Labor + Supplier Pricing EA 3 4,980 14,940
Coarse Bubble Aeration Equipment Est. Labor + Supplier Pricing EA 3 44,059 132,177
Positive Displacement Blowers Est. Labor + Supplier Pricing EA 2 50,000 100,000
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 124,554 124,554
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 223,204 223,204
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 13,000 13,000
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 24
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 25,500 25,500
Subtotal
1,270,910
Contingencies @ 15%
190,637
Total
1,461,547
Total Option A relative estimate of probable construction costs = $1,461,547
6.2. 2.6 MGD PLANT CAPACITY – OPTION B
6.2.1. SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
• Thickened WAS (TWAS) production at 2.6 MGD Capacity
• Reference JSME November 12, 1989 Preliminary Design Submittal for Jamacha Basin
Water Reclamation Facility Upgrade and Expansion Project
• Pounds TWAS total solids per day = 5469 lbs TSS/day
• Gallons per day (assume TWAS @ 4.0% TSS) = 16,200 GPD
• Aerobic Digester Capacity
• Detention time @ 40 days to meet “Class B” requirements
• Digester volume required for 40 day detention time is 648,000 active gallons
6.2.2. AEROBIC DIGESTER PRELIMINARY DESIGN ASSUMPTIONS
• Assume 2 reinforced concrete structures with total overall dimensions of 152’-4” L x 20’-2”
W x 18’ D (each divided into 3 tanks with inside dimensions of 49’-4” L x 27’ W x 18’ D)
including access walkways.
• Assume 1 reinforced concrete pad for digester aeration air blowers.
• Assume coarse bubble aeration equipment in each of the three tanks in each digester.
• Assume 3 positive displace blowers (2 operational, 1 standby)
• Assume 1 telescoping valve in each of the three tanks in each digester.
• Assume 4”-16” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
6.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
AEROBIC DIGESTER – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 289,085 289,085
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 25
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 3,000 9 27,000
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 174,500 174,500
Structural (Reinforced Concrete)
18" SOG (Section 1-4) 25' x 27.17' x 1.5' (8 Each) CY 318 564 179,352
18" SOG (Section 5-6) 27' x 27.17' x 1.5' (4 Each) CY 170 443 75,310
Walls - Exterior (Section 1-6) 207' x 18' x 1.17' (2 Each) CY 340 922 313,480
Walls - Exterior (Section 3-5) 55' x 18' x 1.17' (2 Each) CY 90 922 82,980
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 2 4,000 8,000
PD Blower SOG 25' x 25' x 1.5' (2 Each) CY 74 443 32,782
Structural (Misc. Metals)
Handrails Est. Labor + Supplier Pricing LF 240 55 13,200
Hose Racks Est. Labor + Supplier Pricing EA 8 300 2,400
Mechanical
Telescoping Valves Est. Labor + Supplier Pricing EA 6 4,980 29,880
Coarse Bubble Aeration Equipment Est. Labor + Supplier Pricing EA 6 44,059 264,354
Positive Displacement Blowers Est. Labor + Supplier Pricing EA 3 50,000 150,000
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 2 124,554 249,108
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total EA 2 215,600 431,200
Testing, Start-Up & Commissioning Average 1.25% of Total EA 2 13,000 26,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing EA 2 25,500 51,000
Subtotal
2,399,631
Contingencies @ 15%
359,945
Total
2,759,576
Total Option B relative estimate of probable construction cost = $2,759,576
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 26
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
6.3. 3.9 MGD PLANT CAPACITY – OPTION C
6.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
• Thickened WAS (TWAS) production at 3.9 MGD Capacity
• Reference JSME November 12, 1989 Preliminary Design Submittal for Jamacha Basin
Water Reclamation Facility Upgrade and Expansion Project
• Pounds TWAS total solids per day = 8,190 lbs TSS/day
• Gallons per day (assume TWAS @ 4.0% TSS) = 24,300 GPD
• Aerobic Digester Capacity
• Detention time @ 40 days to meet “Class B” requirements
• Digester volume required for 40 day detention time is 972,000 active gallons
6.3.2. AEROBIC DIGESTER PRELIMINARY DESIGN ASSUMPTIONS
• Assume 3 reinforced concrete structures with total overall dimensions of 152’-4” L x 20’-2”
W x 18’ D (each divided into 3 tanks with inside dimensions of 49’-4” L x 27’ W x 18’ D)
including access walkways.
• Assume 1 reinforced concrete pad for digester aeration air blowers.
• Assume coarse bubble aeration equipment in each of the three tanks in each digester.
• Assume 4 positive displace blowers (3 operational, 1 standby)
• Assume 1 telescoping valve in each of the three tanks in each digester.
• Assume 4”-16” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
6.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
AEROBIC DIGESTER – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 329,085 329,085
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 4,500 9 40,500
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 261,750 261,750
Structural (Reinforced Concrete)
18" SOG (Section 1-4) 25' x 27.17' x 1.5' (12 Each) CY 477 564 269,028
18" SOG (Section 5-6) 27' x 27.17' x 1.5' (6 Each) CY 255 443 112,965
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 27
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Walls - Exterior (Section 1-6) 207' x 18' x 1.17' (3 Each) CY 510 922 470,220
Walls - Exterior (Section 3-5) 55' x 18' x 1.17' (3 Each) CY 135 922 124,470
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 3 4,000 12,000
PD Blower SOG 25' x 25' x 1.5' (3 Each) CY 110 443 48,730
Structural (Misc. Metals)
Handrails Est. Labor + Supplier Pricing LF 360 55 19,800
Hose Racks Est. Labor + Supplier Pricing EA 12 300 3,600
Mechanical
Telescoping Valves Est. Labor + Supplier Pricing EA 9 4,980 44,820
Coarse Bubble Aeration Equipment Est. Labor + Supplier Pricing EA 9 44,059 396,531
Positive Displacement Blowers Est. Labor + Supplier Pricing EA 4 50,000 200,000
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 3 124,554 373,662
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total EA 3 200,000 600,000
Testing, Start-Up & Commissioning Average 1.25% of Total EA 3 13,000 39,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing EA 3 25,500 76,500
Subtotal
3,422,661
Contingencies @ 15%
513,399
Total
3,936,060
Total Option C relative estimate of probable construction cost = $3,936,060
6.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR
AEROBIC DIGESTION
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD $1,461,547
2.6 MGD $2,759,576
3.9 MGD $3,936,060
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 28
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
7. DIGESTED SLUDGE PUMP STATION SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS
FOR VARIOUS TREATMENT PLANT CAPACITIES
7.1. MGD PLANT CAPACITY – OPTION A
7.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
7.1.2. DIGESTED SLUDGE PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete slab with total overall dimensions of 16’ L x 12’ W x 1’ T.
• Assume 2 horizontal centrifugal or progressive cavity skid-mounted pumps & motors.
• Assume 6”-8” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
7.1.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 1.3 MGD (approximate) water reclamation facility within the State
of California.
DIGESTED SLUDGE PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 15,311 15,311
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 120 15 1,800
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 9,250 9,250
Structural (Reinforced Concrete)
DSL Pump Station SOG 12' x 16' x 1' CY 8 592 4,736
Structural (Misc. Metals)
Hose Racks Est. Labor + Supplier Pricing EA 2 250 500
Mechanical
Digested Sludge Pumps & Motors Est. Labor + Supplier Pricing EA 2 13,650 27,300
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 20,667 20,667
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 19,500 19,500
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 2,500 2,500
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 29
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 3,750 3,750
Subtotal
105,314
Contingencies @ 15%
15,797
Total
121,111
Total Option A relative estimate of probable construction costs = $121,111
7.2. 2.6 MGD PLANT CAPACITY – OPTION B
7.2.1. 7.2.1 SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
7.2.2. DIGESTED SLUDGE PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete slab with total overall dimensions of 32’ L x 12’ W x 1’ T.
• Assume 4 horizontal centrifugal or progressive cavity skid-mounted pumps & motors.
• Assume 6”-8” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
7.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
DIGESTED SLUDGE PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 19,311 19,311
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 240 15 3,600
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 18,500 18,500
Structural (Reinforced Concrete)
DSL Pump Station SOG 12' x 32' x 1' CY 16 592 9,472
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 30
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Structural (Misc. Metals)
Hose Racks Est. Labor + Supplier Pricing EA 4 250 1,000
Mechanical
Digested Sludge Pumps & Motors Est. Labor + Supplier Pricing EA 4 13,650 54,600
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 2 20,667 41,334
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 39,000 39,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 5,000 5,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 7,500 7,500
Subtotal
199,317
Contingencies @ 15%
29,898
Total
229,215
Total Option B relative estimate of probable construction cost = $229,215
7.3. 3.9 MGD PLANT CAPACITY – OPTION C
7.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
7.3.2. DIGESTED SLUDGE PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete slab with total overall dimensions of 48’ L x 12’ W x 1’ T.
• Assume 6 horizontal centrifugal or progressive cavity skid-mounted pumps & motors.
• Assume 6”-8” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
7.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 31
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
DIGESTED SLUDGE PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 24,311 24,311
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 360 15 5,400
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 27,000 27,000
Structural (Reinforced Concrete)
DSL Pump Station SOG 12' x 48' x 1' CY 24 592 14,208
Structural (Misc. Metals)
Hose Racks Est. Labor + Supplier Pricing EA 6 250 1,500
Mechanical
Digested Sludge Pumps & Motors Est. Labor + Supplier Pricing EA 6 13,650 81,900
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 3 20,667 62,001
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 53,000 53,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 7,500 7,500
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 11,250 11,250
Subtotal
288,070
Contingencies @ 15%
43,211
Total
331,281
Total Option C relative estimate of probable construction cost = $331,281
7.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR
DIGESTED SLUDGE PUMP STATION
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD $121,111
2.6 MGD $229,215
3.9 MGD $331,281
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 32
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
8. SCUM PUMP STATION SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR VARIOUS
TREATMENT PLANT CAPACITIES
8.1. 1.3 MGD PLANT CAPACITY – OPTION A
8.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
No Scum Pump Station improvements are required for Option A. The existing facility remains in
operation in its current size and condition.
8.2. 2.6 MGD PLANT CAPACITY – OPTION B
8.2.1. SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
8.2.2. SCUM PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete scum box with total overall dimensions of 19’ L x 12’ W x 15’
D.
• Assume 1 reinforced concrete slab with total overall dimensions of 19’ L x 12’ W x 1.5’ T.
• Assume 2 horizontal centrifugal or progressive cavity skid-mounted pumps & motors.
• Assume 6”-8” interconnecting piping, valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
8.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
SCUM PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 23,455 23,455
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 125 15 1,875
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 13,240 13,240
Structural (Reinforced Concrete)
Scum Box SOG 12' x 19' x 1.5' CY 14 526 7,364
Scum Box Walls 43' x 15' x 1' CY 25 1,014 25,350
Scum Pump Station SOG 10' x 11.17' x 1' CY 5 674 3,370
Structural (Misc. Metals)
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 33
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
FRP Grating & Supports Est. Labor + Supplier Pricing SF 150 44 6,600
Galv Ladder & Supports Est. Labor + Supplier Pricing EA 1 2,730 2,730
Hose Racks Est. Labor + Supplier Pricing EA 1 270 270
Mechanical
Scum Pumps & Motors Est. Labor + Supplier Pricing EA 2 10,635 21,270
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 12,992 12,992
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 26,450 26,450
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 2,000 2,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 3,750 3,750
Subtotal
150,716
Contingencies @ 15%
22,607
Total
173,323
Total Option B relative estimate of probable construction costs = $173,323
8.3. 3.9 MGD PLANT CAPACITY – OPTION C
8.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
No additional scum pumping facility requirements are considered necessary for Option C above those
identified under Option B.
8.4. SUMMARY OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR SCUM PUMP
STATION
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD No Improvements Required
2.6 MGD $173,323
3.9 MGD $173,323
9. EFFLUENT PUMP STATION SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR
VARIOUS TREATMENT PLANT CAPACITIES
9.1. 1.3 MGD PLANT CAPACITY – OPTION A
9.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 34
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
No Effluent Pump Station improvements are required for Option A. The existing facility remains in
operation in its current size and condition.
9.2. 2.6 MGD PLANT CAPACITY – OPTION B
9.2.1. SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
9.2.2. EFFLUENT PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete pump station with wetwell inside dimensions of 25’ L x
11’W x 23’-3” HWL.
• Assume 3 vertical turbine pumps and motors.
• Assume 1 slide gate for flow control.
• Assume 12” pump discharge piping into a 12” discharge manifold complete with piping,
valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
9.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
EFFLUENT PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 108,545 108,545
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 1,100 9 9,900
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 62,350 62,350
Structural (Reinforced Concrete)
EPS SOG 13' x 27' x 1.5' CY 21 541 11,361
EPS Walls (Lower Half) 72' x 12.5' x 1.5' CY 53 814 43,142
EPS Walls (Upper Half) 72' x 12.5' x 1.5' CY 53 814 43,142
EPS Interior Baffle Walls 6' x 6' x 6" CY 2 1,420 2,840
EPS Interior Chamber Wall 9' x 22.5' x 1' CY 8 999 7,992
EPS Deck Slab & Beams 11' x 25' x 1' CY 11 1,494 16,434
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 5,000 5,000
Structural (Misc. Metals)
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 35
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
FRP Grating & Supports Est. Labor + Supplier Pricing SF 12 58 696
Aluminum Handrail Est. Labor + Supplier Pricing LF 100 55 5,500
Stairs Est. Labor + Supplier Pricing EA 1 5,205 5,205
Hose Racks Est. Labor + Supplier Pricing EA 1 210 210
Precast Vault & Hatch Est. Labor + Supplier Pricing EA 1 6,210 6,210
Mechanical
Vertical Turbine Pumps & Motors Est. Labor + Supplier Pricing EA 3 62,865 188,595
Aluminum Slide Gates, Frames & Operators Est. Labor + Supplier Pricing EA 1 9,915 9,915
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 23,106 23,106
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 110,230 110,230
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 10,000 10,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 15,000 15,000
Subtotal
685,373
Contingencies @ 15%
102,806
Total
788,179
Total Option B relative estimate of probable construction costs = $788,179
9.3. 3.9 MGD PLANT CAPACITY – OPTION C
9.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
9.3.2. EFFLUENT PUMP STATION PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 reinforced concrete pump station with wetwell inside dimensions of 50’ L x
11’W x 23’-3” HWL.
• Assume 6 vertical turbine pumps and motors.
• Assume 1 slide gate for flow control.
• Assume 12” pump discharge piping into a 16” discharge manifold complete with piping,
valves, supports and appurtenances.
• Assume electrical & instrumentation systems for power and control.
9.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 36
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
EFFLUENT PUMP STATION – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 175,550 175,550
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 2,200 9 19,800
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 125,000 125,000
Structural (Reinforced Concrete)
EPS SOG 13' x 54' x 1.5' CY 42 541 22,722
EPS Walls (Lower Half) 122' x 12.5' x 1.5' CY 106 814 86,284
EPS Walls (Upper Half) 122' x 12.5' x 1.5' CY 106 814 86,284
EPS Interior Baffle Walls 6' x 6' x 6" (2 Each) CY 4 1,420 5,680
EPS Interior Chamber Wall 9' x 22.5' x 1' (2 Each) CY 16 999 15,984
EPS Deck Slab & Beams 11' x 50' x 1' CY 22 1,494 32,868
Misc. - Hydrotest Tanks & Dewater Est. Labor & Equipment LS 1 10,000 10,000
Structural (Misc. Metals)
FRP Grating & Supports Est. Labor + Supplier Pricing SF 24 58 1,392
Aluminum Handrail Est. Labor + Supplier Pricing LF 200 55 11,000
Stairs Est. Labor + Supplier Pricing EA 2 5,205 10,410
Hose Racks Est. Labor + Supplier Pricing EA 2 210 420
Precast Vault & Hatch Est. Labor + Supplier Pricing EA 2 6,210 12,420
Mechanical
Vertical Turbine Pumps & Motors Est. Labor + Supplier Pricing EA 6 62,865 377,190
Aluminum Slide Gates, Frames & Operators Est. Labor + Supplier Pricing EA 2 9,915 19,830
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 46,212 46,212
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 232,000 232,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 20,000 20,000
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 37
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 30,000 30,000
Subtotal
1,341,046
Contingencies @ 15%
201,157
Total
1,542,203
Total Option C relative estimate of probable construction cost = $1,542,203
9.4. ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR EFFLUENT
PUMP STATION
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD No Improvements Required
2.6 MGD $788,179
3.9 MGD $1,542,203
10. ADMINISTRATION BUILDING SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR
VARIOUS TREATMENT PLANT CAPACITIES
10.1. 1.3 MGD PLANT CAPACITY – OPTION A
10.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
No Administration Building improvements are required for Option A. The existing facility remains in
operation in its current size and condition.
10.2. 2.6 MGD PLANT CAPACITY – OPTION B
10.2.1. SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
No Administration Building improvements are required for Option B. The existing facility remains in
operation in its current size and condition.
10.3. 3.9 MGD PLANT CAPACITY – OPTION C
10.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
10.3.2. ADMINISTRATION BUILDING PRELIMINARY DESIGN ASSUMPTIONS
• Assume 1 single-story masonry and wood framed structure with outside dimensions of
104’ L x 42’W (4,368 square feet).
• Assume reinforced concrete slab on grade.
• Assume fully-grouted split-face masonry (CMU) exterior walls.
• Assume wood roof trusses with insulation and standing seam metal roofing system.
• Assume multi-use floor plan with offices, lab, break room, rest rooms, hallways and
shop/garage.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 38
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Assume exterior hollow metal doors, frames and finish hardware.
• Assume interior wood doors, frames and finish hardware.
• Assume exterior aluminum frame windows with interior window coverings.
• Assume interior vinyl flooring.
• Assume ceramic tile rest rooms complete with toilet partitions and accessories.
• Assume laboratory with cabinetry and lab equipment.
• Assume interior metal stud partition walls with drywall, tape, texture, and painted finish.
• Assume fire sprinkler system throughout.
• Assume HVAC system throughout.
• Assume plumbing system throughout.
• Assume fire and security alarm systems throughout.
• Assume electrical & instrumentation systems for power, lighting and control.
• Assume ADA compliance for the entire building.
10.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
ADMINISTRATION BUILDING – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 135,471 135,471
Civil
Demolish & Dispose of Existing Admin. Bldg. Future Demo N/A 0 0 0
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 500 9 4,500
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 73,515 73,515
Structural
Concrete Slab On Grade & Footings 4365 x 6" CY 85 515 43,775
CMU Masonry Walls Est. Subcontractor Pricing SF 3,130 18 56,340
Wood Roof Trusses Est. Subcontractor Pricing SF 5,184 8 41,472
Roofing, Insulation & Trim Est. Subcontractor Pricing SF 5,184 11 57,024
Hollow Metal Doors, Frames & Hardware Est. Subcontractor Pricing EA 5 1,050 5,250
Overhead Roll-up Doors & Operators Est. Subcontractor Pricing EA 2 4,500 9,000
Aluminum Windows & Frames Est. Subcontractor Pricing EA 10 830 8,300
Louvers & Vents Est. Subcontractor Pricing EA 1 450 450
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 39
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Caulking & Sealants Est. Subcontractor Pricing LS 1 2,250 2,250
Painting & Coatings Est. Subcontractor Pricing LS 1 7,500 7,500
Architectural
Misc. Metals Est. Subcontractor Pricing LS 1 3,000 3,000
Metal Studs Est. Subcontractor Pricing SF 5,100 3 15,300
Drywall, Tape & Texture Est. Subcontractor Pricing SF 9,000 2 18,000
Acoustical Ceiling Est. Subcontractor Pricing SF 2,164 5 10,820
Building Insulation Est. Subcontractor Pricing SF 2,548 2 5,096
Flooring Est. Subcontractor Pricing SF 2,548 6 15,288
Interior Doors, Frames & Hardware Est. Subcontractor Pricing EA 10 450 4,500
Cabinetry & Countertops Est. Subcontractor Pricing LF 32 295 9,440
Lab Equipment & Furnishings Est. Subcontractor Pricing LS 1 18,000 18,000
Restroom Ceramic Tile Est. Subcontractor Pricing SF 448 8 3,584
Toilet Partitions Est. Subcontractor Pricing LF 56 30 1,680
Toilet Accessories Est. Subcontractor Pricing LS 1 2,250 2,250
Benches, Shelving & Lockers Est. Subcontractor Pricing EA 8 1,300 10,400
Window Coverings Est. Subcontractor Pricing SF 176 15 2,640
Caulking & Sealants Est. Subcontractor Pricing LS 1 2,250 2,250
Painting & Coatings Est. Subcontractor Pricing LS 1 13,026 13,026
ADA Compliance Est. Subcontractor Pricing LS 1 2,250 2,250
Signage & Misc. Specialties Est. Subcontractor Pricing LS 1 7,500 7,500
Mechanical
HVAC Est. Subcontractor Pricing SF 2,548 15 38,220
Plumbing (Rough & Finish) Est. Subcontractor Pricing LS 1 15,000 15,000
Fire Protection & Extinguishers Est. Subcontractor Pricing SF 4,368 4 17,472
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 167,540 167,540
Building Lighting & Circuits Est. Subcontractor Pricing SF 4,368 11 48,048
Fire Alarms Est. Subcontractor Pricing SF 4,368 1 4,368
Security Systems Est. Subcontractor Pricing SF 4,368 2 8,736
Communication & Data Systems Est. Subcontractor Pricing LS 1 3,000 3,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 12,000 12,000
Subtotal
904,255
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 40
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Contingencies @ 15%
135,638
Total
1,039,893
Total Option C relative estimate of probable construction costs = $1,039,893
10.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR
ADMINISTRATION BUILDING
Plant Capacity Estimate of Probable Construction Costs**
1.3 MGD No Improvements Required
2.6 MGD No Improvements Required
3.9 MGD $1,039,893
11. BLOWER AND ELECTRICAL BUILDING WITH STANDBY POWER GENERATION SIZING CRITERIA AND ESTIMATES
OF PROBABLE CONSTRUCTION COSTS FOR VARIOUS TREATMENT PLANT CAPACITIES
11.1. 1.3 MGD PLANT CAPACITY OPTION
11.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
No Blower and Electrical Building improvements are required for Option A. The existing facility remains
in operation in its current size and condition.
11.2. 2.6 MGD PLANT CAPACITY – OPTION B
11.2.1. SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
11.2.2. BLOWER AND ELECTRICAL BUILDING WITH STANDBY POWER GENERATOR PRELIMINARY DESIGN ASSUMPTIONS
• Assume demolition of existing Blower Building.
• Assume relocation and reuse of 2 existing blowers.
• Assume 1 single-story pre-engineered metal building structure with outside dimensions of
90’ L x 34’W (3,060 square feet).
• Assume reinforced concrete slab on grade.
• Assume metal frame wall and roof construction with wall and roof insulation, fluted metal
roofing system, and metal trim.
• Assume multi-use floor plan with one blower equipment room and one electrical room.
• Assume exterior and interior hollow metal doors, frames and finish hardware.
• Assume exterior aluminum frame windows.
• Assume no interior flooring (smooth trowel finish concrete).
• Assume fire sprinkler system throughout.
• Assume HVAC system in electrical room only.
• Assume plumbing system for washwater in blower room only.
• Assume fire and security alarm systems throughout.
• Assume 3 multi-stage centrifugal blowers, motors and appurtenances (4 operating and 1
standby with 3 new blowers and 2 relocated blowers).
• Assume 4”-30” interconnecting piping, ductwork, valves, supports and appurtenances.
• Assume 1 skid-mounted 250 kW diesel-fuel standby power generator (exterior install).
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 41
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Assume electrical & instrumentation systems for power, lighting and control.
11.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
BLOWER AND ELECTRICAL BUILDING WITH STANDBY POWER GENERATOR – PROBABLE
CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 312,450 312,450
Civil
Demolish & Dispose of Existing Blower Bldg. Est. Labor & Equipment LS 1 50,000 50,000
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 250 9 2,250
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 148,650 148,650
Structural
Concrete Slab On Grade & Foundations 3090 x 6" + Blower Pads CY 101 679 68,579
Pre-Engineered Metal Building Est. Subcontractor Pricing SF 3,060 45 137,700
Wall Louvers Est. Subcontractor Pricing SF 104 45 4,680
Insulation Est. Subcontractor Pricing SF 3,060 2 6,120
Hollow Metal Doors, Frames & Hardware Est. Subcontractor Pricing EA 4 1,200 4,800
Overhead Roll-up Doors & Operators Est. Subcontractor Pricing EA 1 4,500 4,500
Aluminum Windows & Frames Est. Subcontractor Pricing EA 4 500 2,000
Louvers & Vents Est. Subcontractor Pricing EA 1 500 500
Caulking & Sealants Est. Subcontractor Pricing LS 1 1,000 1,000
Painting & Coatings Est. Subcontractor Pricing LS 1 15,000 15,000
Concrete Equipment Pads & Foundations Est. Subcontractor Pricing LS 1 2,487 2,487
Signage Est. Subcontractor Pricing LS 1 1,125 1,125
Mechanical (Process)
Multi-Stage Centrifugal Blowers Est. Labor + Supplier Pricing EA 3 140,885 422,655
Install OFCI Relocated Blowers Est. Labor + Supplier Pricing EA 2 15,000 30,000
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 106,185 106,185
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 42
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Mechanical (Building)
HVAC Est. Subcontractor Pricing SF 600 6 3,600
Fire Protection & Extinguishers Est. Subcontractor Pricing SF 3,060 4 12,240
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 317,500 317,500
Lighting Est. Subcontractor Pricing SF 3,060 2 6,120
Fire Alarms Est. Subcontractor Pricing SF 3,060 1 3,060
Security Systems Est. Subcontractor Pricing SF 3,060 2 6,120
250 KW Standby Generator Est. Labor + Supplier Pricing EA 1 95,250 95,250
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 20,000 20,000
Subtotal
1,784,571
Contingencies @ 15%
267,686
Total
2,052,257
Total Option B relative estimate of probable construction costs = $2,052,257
11.3. 3.9 MGD PLANT CAPACITY – OPTION C
11.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
11.3.2. BLOWER AND ELECTRICAL BUILDING WITH STANDBY POWER GENERATOR PRELIMINARY DESIGN ASSUMPTIONS
• Assume demolition of existing Blower Building.
• Assume relocation and reuse of two existing blowers.
• Assume 1 single-story pre-engineered metal building structure with outside dimensions of
90’ L x 34’W (3,060 square feet).
• Assume reinforced concrete slab on grade.
• Assume metal frame wall and roof construction with wall and roof insulation, fluted metal
roofing system, and metal trim.
• Assume multi-use floor plan with one blower equipment room and one electrical room.
• Assume exterior and interior hollow metal doors, frames and finish hardware.
• Assume exterior aluminum frame windows.
• Assume no interior flooring (smooth trowel finish concrete).
• Assume fire sprinkler system throughout.
• Assume HVAC system in electrical room only.
• Assume plumbing system for washwater in blower room only.
• Assume fire and security alarm systems throughout.
• Assume 5 multi-stage centrifugal blowers, motors and appurtenances (6 operating and 1
standby with 5 new blowers and 2 relocated blowers).
• Assume 4”-30” interconnecting piping, ductwork, valves, supports and appurtenances.
• Assume 1 skid-mounted 250 kW diesel-fuel standby power generator (exterior install).
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 43
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Assume electrical & instrumentation systems for power, lighting and control.
11.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
BLOWER AND ELECTRICAL BUILDING WITH STANDBY POWER GENERATOR – PROBABLE
CONSTRUCTION COSTS
Description Dimensions Unit Quantity
Unit
Price
Total
Price
General Conditions Approx. 15% of Total LS 1 312,450 312,450
Civil
Demolish & Dispose of Existing Blower Bldg. Est. Labor & Equipment LS 1 50,000 50,000
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 250 9 2,250
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 148,650 148,650
Structural
Concrete Slab On Grade & Foundations 3090 x 6" + Blower Pads CY 101 679 68,579
Pre-Engineered Metal Building Est. Subcontractor Pricing SF 3,060 45 137,700
Wall Louvers Est. Subcontractor Pricing SF 104 45 4,680
Insulation Est. Subcontractor Pricing SF 3,060 2 6,120
Hollow Metal Doors, Frames & Hardware Est. Subcontractor Pricing EA 4 1,200 4,800
Overhead Roll-up Doors & Operators Est. Subcontractor Pricing EA 1 4,500 4,500
Aluminum Windows & Frames Est. Subcontractor Pricing EA 4 500 2,000
Louvers & Vents Est. Subcontractor Pricing EA 1 500 500
Caulking & Sealants Est. Subcontractor Pricing LS 1 1,000 1,000
Painting & Coatings Est. Subcontractor Pricing LS 1 15,000 15,000
Concrete Equipment Pads & Foundations Est. Subcontractor Pricing LS 1 2,487 2,487
Signage Est. Subcontractor Pricing LS 1 1,125 1,125
Mechanical (Process)
Multi-Stage Centrifugal Blowers Est. Labor + Supplier Pricing EA 5 140,885 704,425
Install OFCI Relocated Blowers Est. Labor + Supplier Pricing EA 2 15,000 30,000
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 146,185 146,185
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 44
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Mechanical (Building)
HVAC Est. Subcontractor Pricing SF 600 6 3,600
Fire Protection & Extinguishers Est. Subcontractor Pricing SF 3,060 4 12,240
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 374,527 374,527
Lighting Est. Subcontractor Pricing SF 3,060 2 6,120
Fire Alarms Est. Subcontractor Pricing SF 3,060 1 3,060
Security Systems Est. Subcontractor Pricing SF 3,060 2 6,120
250 KW Standby Generator Est. Labor + Supplier Pricing EA 1 95,250 95,250
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 20,000 20,000
Subtotal
2,163,368
Contingencies @ 15%
324,505
Total
2,487,873
Total Option C relative estimate of probable construction cost = $2,487,873
11.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR
BLOWER AND ELECTRICAL BUILDING WITH STANDBY POWER GENERATOR
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD No Improvements Required
2.6 MGD $2,052,257
3.9 MGD $2,487,873
12. WAS THICKENING SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COST FOR VARIOUS
TREATMENT PLANT CAPACITIES
12.1. 1.3 MGD PLANT CAPACITY – OPTION A
12.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
• Secondary sludge production at 1.3 MGD Capacity
• Reference JSME November 12, 1989 Preliminary Design Submittal for Jamacha Basin
Water Reclamation Facility Upgrade and Expansion Project
• Pounds WAS total solids per day = 2,730 lbs TSS/day
• Gallons per day (assume RAS @ 0.50% TSS) = 64,800 GPD
• Gallons per minute (assume 24 hour/day operation) = 45 GPM
DAF Thickener Sizing Criteria
• Maximum Hydraulic Loading: 0.50 GPM/SF
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 45
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Maximum Solids Loading: 1.3 lbs TSS/hr-SF
• Minimum Float Solids: 4.0 %TS
• Minimum SS Capture: 97%
• Maximum Polymer Dose: 5 dry lbs/dry ton TSS
NUMBER AND SIZE OF DAF UNITS
• Number: 1
• Length: 13’-2”
• Width: 7’-10”
• Effective surface area: 103 SF
CHECK LOADINGS VERSUS SIZING CRITERIA
• Hydraulic Loading: 0.43 GPM/SF OK
• Solids Loading: 0.90 lbs TSS/hr-SF OK
12.1.2. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 1.3 MGD (approximate) water reclamation facility within the State
of California.
WAS THICKENING – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 95,000 95,000
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 390 9 3,510
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 56,000 56,000
Structural (Reinforced Concrete)
18" SOG 25' x 19' x 1.5' CY 27 850 22,950
Structural (Misc. Metals)
Misc. Metals & Fabrications Est. Labor + Supplier Pricing LS 1 3,500 3,500
Mechanical
DAF Equipment Est. Labor + Supplier Pricing EA 1 405,000 405,000
Electrical & Instrumentation
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 46
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
E&I Power & Control Systems Average 17.5% of Total LS 1 115,000 115,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 14,000 14,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 22,000 22,000
Subtotal
736,960
Contingencies @ 15%
110,544
Total
847,504
Total Option A relative estimate of probable construction cost = $847,504
12.2. 2.6 MGD PLANT CAPACITY – OPTION B
12.2.1. SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
• Secondary sludge production at 2.6 MGD Capacity
• Reference JSME November 12, 1989 Preliminary Design Submittal for Jamacha Basin
Water Reclamation Facility Upgrade and Expansion Project (submittal based on 1.3 MGD
ADF and projected for 2.6 MGD ADF herein)
• Pounds WAS total solids per day = 5,460 lbs TSS/day
• Gallons per day (assume RAS @ 0.50% TSS) = 129,600 GPD
• Gallons per minute (assume 24 hour/day operation) = 90 GPM
DAF Thickener Sizing Criteria
• Maximum Hydraulic Loading: 0.50 GPM/SF
• Maximum Solids Loading: 1.3 lbs TSS/hr-SF
• Minimum Float Solids: 4.0 %TS
• Minimum SS Capture: 97%
• Maximum Polymer Dose: 5 dry lbs/dry ton TSS
NUMBER AND SIZE OF DAF UNITS
• Number: 2
• Length: 13’-2”
• Width: 7’-10”
• Effective surface area: 103 SF
CHECK LOADINGS VERSUS SIZING CRITERIA
• Hydraulic Loading: 0.43 GPM/SF OK
• Solids Loading: 0.90 lbs TSS/hr-SF OK
12.2.2. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 47
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
WAS THICKENING – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 120,000 120,000
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 780 9 7,020
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 75,000 75,000
Structural (Reinforced Concrete)
18" SOG (2 Each) 25' x 19' x 1.5' CY 54 850 45,900
Structural (Misc. Metals)
Misc. Metals & Fabrications Est. Labor + Supplier Pricing LS 2 3,500 7,000
Mechanical
DAF Equipment Est. Labor + Supplier Pricing EA 2 405,000 810,000
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 236,000 236,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 28,000 28,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 44,000 44,000
Subtotal
1,372,920
Contingencies @ 15%
205,938
Total
1,578,858
Total Option B relative estimate of probable construction cost = $1,578,858
12.3. 3.9 MGD PLANT CAPACITY – OPTION C
12.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
• Secondary sludge production at 3.9 MGD Capacity
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 48
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Reference JSME November 12, 1989 Preliminary Design Submittal for Jamacha Basin
Water Reclamation Facility Upgrade and Expansion Project(submittal based on 1.3 MGD
ADF and projected for 3.9 MGD ADF herein)
• Pounds WAS total solids per day = 8,190 lbs TSS/day
• Gallons per day (assume RAS @ 0.50% TSS) = 194,400 GPD
• Gallons per minute (assume 24 hour/day operation) = 135 GPM
DAF Thickener Sizing Criteria
• Maximum Hydraulic Loading: 0.50 GPM/SF
• Maximum Solids Loading: 1.3 lbs TSS/hr-SF
• Minimum Float Solids: 4.0 %TS
• Minimum SS Capture: 97%
• Maximum Polymer Dose: 5 dry lbs/dry ton TSS
NUMBER AND SIZE OF DAF UNITS
• Number: 3
• Length: 13’-2”
• Width: 7’-10”
• Effective surface area: 103 SF
CHECK LOADINGS VERSUS SIZING CRITERIA
• Hydraulic Loading: 0.43 GPM/SF OK
• Solids Loading: 0.90 lbs TSS/hr-SF OK
12.3.2. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
WAS THICKENING – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 150,000 150,000
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 1,170 9 10,530
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 105,000 105,000
Structural (Reinforced Concrete)
18" SOG (3 Each) 25' x 19' x 1.5' CY 81 850 68,850
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 49
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Structural (Misc. Metals)
Misc. Metals & Fabrications Est. Labor + Supplier Pricing LS 1 10,500 10,500
Mechanical
DAF Equipment Est. Labor + Supplier Pricing EA 3 405,000 1,215,000
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 354,000 354,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 28,000 28,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 66,000 66,000
Subtotal
2,007,880
Contingencies @ 15%
301,182
Total
2,309,062
Total Option C relative estimate of probable construction cost = $2,309,062
12.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR
WAS THICKENING
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD $847,504
2.6 MGD $1,578,858
3.9 MGD $2,309,062
13. SLUDGE DEWATERING CENTRIFUGE SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS
FOR VARIOUS TREATMENT OPTIONS
13.1. 1.3 MGD PLANT CAPACITY – OPTION A
13.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
• Digested sludge production at 1.3 MGD Capacity
• Reference JSME November 12, 1989 Preliminary Design Submittal for Jamacha Basin
Water Reclamation Facility Upgrade and Expansion Project (parameters for 2.6 MGD and
3.9 MGD options projected base on preliminary design at 1.3 MGD ADF)
• Pounds TWAS total solids per day = 2,730 lbs TSS/day
• Gallons TWAS per day (assume TWAS @ 4.0% TSS) = 8,100 GPD
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 50
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Digested sludge total solids per day (assume 35% TSS reduction via aerobic digestion) =
1,775 lbs TSS/day
• Centrifuge Loading and Performance Criteria
• Operate 6 hours/day (assumes 1 hour per day for start-up and 1 hour/day for shut down)
• Hydraulic loading = 8,100/(6 x 60) = 23 GPM
• Total solids loading = 1,775 lbs/6 hours = 296 lbs/hour
• Cake solids = 20% TS minimum
• Solids capture = 95% minimum
• Polymer dose = 25 dry lbs/dry ton TSS maximum
13.1.2. SLUDGE DEWATERING CENTRIFUGE PRELIMINARY DESIGN ASSUMPTIONS
• Number: 1
• Manufacture: Alfa Laval
• Model: ALDEC G2-45
• Assume centrifuge installed on new above ground steel covered structure
• Assume one centrifuge to be installed
• Assume electrical & instrumentation systems for power and control.
13.1.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 1.3 MGD (approximate) water reclamation facility within the State
of California.
SLUDGE DEWATERING CENTRIFUGE – PROBABLE CONSTRUCTION COSTS
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 105,000 105,000
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 50 9 450
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 45,000 45,000
Structural (Reinforced Concrete)
Misc. / Footings Misc. CY 2 850 1,700
Structural (Misc. Metals)
Cover & Support Structure Est. Labor + Supplier Pricing LS 1 96,300 96,300
Mechanical
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 51
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Centrifuge Equipment Est. Labor + Supplier Pricing EA 1 418,000 418,000
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 107,600 107,600
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 11,000 11,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 11,000 11,000
Subtotal
796,050
Contingencies @ 15%
119,408
Total
915,458
Total Option A relative estimate of probable construction cost = $915,458
13.2. 2.6 MGD PLANT CAPACITY – OPTION B
13.2.1. SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
Selected Alfa Laval ALDEC G2-45 Centrifuge is sized for an upper operating range of 50 GPM. Under the
2.6 MGD scenario the daily digested sludge volume will be 8,200 GPD and the centrifuge will be loaded
at 46 GPM over a 6 hour operating period. No additional improvements are required beyond the
installation of one centrifuge.
Total Option B relative estimate of probable construction cost = $915,458
13.3. 3.9 MGD PLANT CAPACITY – OPTION C
13.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
13.3.2. SLUDGE DEWATERING CENTRIFUGE PRELIMINARY DESIGN ASSUMPTIONS
• Number: 2
• Manufacture: Alfa Laval
• Model: ALDEC G2-45
• Assume centrifuges installed on new above ground steel covered structures
• Assume two centrifuges to be installed
• Assume electrical & instrumentation systems for power and control.
13.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Centrifuge installed on new above ground steel covered structure
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 52
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
SLUDGE DEWATERING CENTRIFUGE – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 105,000 105,000
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 100 9 900
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 75,000 75,000
Structural (Reinforced Concrete)
Misc. / Footings Misc. CY 4 850 3,400
Structural (Misc. Metals)
Cover & Support Structure Est. Labor + Supplier Pricing LS 2 96,300 192,600
Mechanical
Centrifuge Equipment Est. Labor + Supplier Pricing EA 2 418,000 836,000
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 263,000 263,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 22,000 22,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 22,000 22,000
Subtotal
1,519,900
Contingencies @ 15%
227,985
Total
1,747,885
Total Option C relative estimate of probable construction cost = $1,747,885
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 53
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
13.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS) FOR
CENTRIFUGE DEWATERING
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD $915,458
2.6 MGD $915,458
3.9 MGD $1,747,885
14. TERTIARY FILTER SIZING CRITERIA AND ESTIMATES OF PROBABLE CONSTRUCTION COSTS FOR VARIOUS
TREATMENT PLANT CAPACITIES
14.1. BASIS OF COST ESTIMATES FOR TERTIARY FILTRATION IMPROVEMENTS
• Use ARCADIS / Malcolm Pirnie’s cost estimates for the recently completed Fallbrook WRP
1 Capital Improvement Plan.
• Fallbrook estimates are based on November 2010 dollars
• Fallbrook estimates are based on ADWF of 2.7 MGD and 2.9 MGD ADWF + recycle flows
• Prorate Fallbrook estimates for inflation at 3.5% per year from November 2010 to May
2012. Inflation factor is 1.053
• Prorate Fallbrook estimates for capacity/size adjustments
• For 1.3 MGD Option A scenario, no additional capacity is required
• For 2.6 MGD Option B scenario use additional capacity/size adjustment factor of 0.481
(1.3/2.7)
• For 3.9 MGD Option C scenario use additional capacity/size adjustment factor of 0.963
(2.6/2.7)
• Given the conservative loading rates established for this assessment, it is assumed that
filter effluent requirements can be met without the addition of upstream coagulants.
14.2. BASELINE IMPROVEMENTS TO ESTABLISH OPTIONS A, B, AND C COST ESTIMATES
Use basis of cost for Fallbrook WRP 1 Estimates of Probable Construction Costs (based on November
2010 dollars)
14.2.1. SIZING CRITERIA
• Ultimate average flow: 2.7 MGD
• Ultimate average flow + Recycle: 2.9 MGD
• Maximum Hydraulic Loading Rate (with one unit out of service) @ Q AVG + Recycle:
4.0 GPM/SF
NUMBER AND SIZE OF FILTERS IDENTIFIED BY ARCADIS / MALCOLM PIRNIE FOR FALLBROOK WRP 1 TERTIARY FILTRATION
• Number: 4
• Length: 13’
• Width: 13’
• Depth: 14.5’
• Side Wall Freeboard: 3’
• Media Depth: 60”
• Media Type: Anthracite
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 54
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Flocculation channels 7’W X 7’D X 26’L with 2’ freeboard
• Mechanical Flocculators 2 units @ 5 Hp each
• Polyblend Units 2 units (1 operating, 1 standby)
• Use chemical totes for polymer
CHECK LOADINGS VERSUS SIZING CRITERIA (WITH ONE UNIT OUT OF SERVICE)
• Overflow Rate (with one unit out of service) @ Q AVG + Recycle: 4.0 GPM/SF OK
14.2.2. ESTIMATES OF PROBABLE CONSTRUCTION COSTS BY ARCADIS MALCOLM PIRNIE FOR FALLBROOK WRD 1
TERTIARY FILTRATION AT A CAPACITY OF 2.7 MGD AVERAGE FLOW
Assumptions:
• Costs based on November 2010 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar water reclamation facility within the State of California.
TERTIARY FILTERS – PROBABLE CONSTRUCTION COSTS FOR 2.7 MGD (November 2010 Dollars)
Description Dimensions/Clarifications Unit Quantity Unit Price
Total
Price
General Conditions Approx. 15% of Total LS 1 132,900 132,900
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 2,500 9 22,500
Site Improvements, Yard Piping &
Restoration Approx. 8% of Total LS 1 63,500 63,500
Structural (Reinforced Concrete)
Base SOG Filters 15' x 15' x 2' (4 Each) CY 67 975 65,325
Walls Filters 56' x 14.5' x 1' (2 Each) CY 60 975 58,500
Walls Filters 15' x 14.5' x 1' (4 Each) CY 33 975 32,175
WBW Tank SOG 22' x 22' x 2' CY 36 975 35,100
WBW Tank Walls 20' x 14.5' x 1.25' (4 Each) CY 54 975 52,650
Floc Tank SOG 28 x 10’ x 2’ CY 21 975 20,475
Floc Tank Walls (26’+7’) x 2 x 9’ x 1’ CY 22 975 21,450
Structural (Misc. Metals)
Misc. Metals & Fabrications Est. Labor + Supplier Pricing LS 1 26,600 26,600
Mechanical
Launders, Weirs & Supports Est. Labor + Supplier Pricing EA 1 32,000 32,000
Underdrains Est. Labor + Supplier Pricing SF 676 150 101,400
Air Scour Compressors Est. Labor + Supplier Pricing EA 2 15,000 30,000
Filter Media Est. Labor + Supplier Pricing CY 125 175 21,875
Waste Backwash Pumps Est. Labor + Supplier Pricing EA 2 15,000 30,000
Polymer Addition Est. Labor + Supplier Pricing EA 2 32,000 64,000
Process Piping, Valves & Supports Est. Labor + Supplier Pricing LS 1 110,000 110,000
Electrical & Instrumentation
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 55
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
E&I Power & Control Systems Average 17.5% of Total LS 1 145,000 145,000
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 35,000 35,000
Miscellaneous
Painting & Coatings Est. Subcontractor Pricing LS 1 25,000 25,000
Subtotal
1,125,450
Contingencies @ 15%
152,929
Total
1,278,379
Total relative estimate of probable construction cost for capacity of 2.7 MGD average flow = $1,278,379
(November 2010 dollars)
14.3. SUMMARY OF TERTIARY FILTRATION ESTIMATES OF PROBABLE CONSTRUCTION COSTS (BASED ON MAY 2012
DOLLARS)
14.3.1. 1.3 MGD PLANT CAPACITY – OPTION A (EXISTING FACILITIES VALUE)
No Tertiary Filter improvements are required for Option A. The existing facility remains in operation in
its current size and condition.
14.3.2. 2.6 MGD PLANT CAPACITY – OPTION B (EXPAND FROM 1.3 MGD TO 2.6 MGD)
Determine additional cost for Option B capacity to existing facilities based on the probable estimate for
1.3 MGD expansion.
$1,278,379 X 1.3 / 2.7 (size adjustment) x 1.053 (inflation adjustment) = $648,138
14.3.3. 3.9 MGD PLANT CAPACITY – OPTION C (EXPAND FROM 1.3 MGD TO 3.9 MGD)
Determine additional cost for Option C capacity to existing facilities based on the probable estimate for
2.6 MGD expansion.
$1,278,379 X 2.6 / 2.7 (size adjustment) x 1.053 (inflation adjustment) = $1,296,276
15. CHLORINE CONTACT TANK, SODIUM HYPOCHLORITE STORAGE AND CHEMICAL FEED FACILITIES FOR TERTIARY
DISINFECTION
15.1. 1.3 MGD PLANT CAPACITY – OPTION A
15.1.1. SIZING CRITERIA – AVERAGE FLOW: 1.3 MGD
No Tertiary Disinfection improvements are required for Option A. The existing facility remains in
operation in its current size and condition.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 56
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
15.2. 2.6 MGD PLANT CAPACITY – OPTION B
15.2.1. SIZING CRITERIA – AVERAGE FLOW: 2.6 MGD
15.2.2. DISINFECTION PRELIMINARY DESIGN ASSUMPTIONS
• Assume a minimum CT of 450 mg-min/l for Title 22 treatment.
• Provide 90 minute hydraulic detention time in contact tank at peak flowrates. Recognizing
that the RWCWRF is a scalping facility, use average flow or 2.6 MGD to be equal to peak
process flowrate to disinfection. Assume an additional 15% flow to the process flowrate to
consider clean-out volumes, surges, etc. Therefore assume total maximum design flow to
chlorination @ 3.0 MGD.
• Contact volume @ 25,065 cu. Ft.
• CCT channel dimensions @ 8 ft wide x 8 ft deep x 390 ft long. Use 3 pass configuration
each pass @ 130 ft. long with 2 ft freeboard. Slab with 1 foot extended footings.
• Assume a chlorine dosage of 5 mg/l for effluent disinfection
• Detention time in reclaimed water transmission line not considered for contact time
• Assume 12.5% sodium hypochlorite delivered to site
• Assume continuous RAS chlorination at 1.5 # chlorine/1,000 #s MLVSS
• Assume 12 hr HRT and MLSS of 2,500 mg/l (% MLVSS @ 72%)
• Assume RAS concentration @ 7,500 mg/l
• Volume of sodium hypochlorite/day required for disinfection = 120 gal/day
• Volume of sodium hypochlorite / day required for RAS bulking control = 92 gal/day
• Provide 15 days of sodium hypochlorite storage (Note: half-life of NaOCl solution is
approximately 30 days, therefore limit storage to not more than approximately 2 weeks)
• Storage volume = approximately 3,180 gals (use totes for storage)
• Provide duty and standby chemical metering pumps for sodium hypochlorite delivery to
disinfection and RAS
• Provide protective canopy over contact tank and chemical feed facilities
15.2.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 2.6 MGD (approximate) water reclamation facility within the State
of California.
CHLORINE CONTACT TANK, SODIUM HYPOCHLORITE STORAGE AND CHEMICAL FEED FACILITIES FOR
TERTIARY DISINFECTION FACILITIES – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price Total Price
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 570 9 5,130
Site Improvements, Yard Piping & Restoration Approx. 8% of Total LS 1 150,000 150,000
Structural (Reinforced Concrete)
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 57
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
CCT SOG 132' x 30 x 2' (3 passes) CY 293 850 249,050
Walls 130' x 10' x 1' (2 Each) CY 96 975 93,600
Walls 122 x 10' x 1' (2 Each) CY 90 975 87,750
Walls 28 x 10' x 1' (2 Each) CY 21 975 20,475
NaOCl Storage and Feed SOG 22' x 22' x 2' CY 36 975 35,100
NaOCl Storage and Feed Containment Walls 22' x 3' x 1' (4 Each) CY 10 975 9,750
Structural (Misc. Metals)
Misc. Metals & Fabrications
Est. Labor + Supplier
Pricing LS 1 20,500 20,500
Structural (Misc. Metals)
Canopy & Support Structure (3,625 sq. ft.)
Est. Labor + Supplier
Pricing LS 1 180,000 180,000
Mechanical
Chemical Feed Equipment, piping and misc.
valves and instruments
Est. Labor + Supplier
Pricing EA 4 64,000 256,000
Miscellaneous
Painting & Coatings
Est. Subcontractor
Pricing LS 1 52,000 52,000
Subtotal
1,159,355
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 225,000 306,245
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 8,500 21,875
General Conditions Average 15% of Total LS 1 120,410 262,495
Subtotal
1,749,970
Contingencies @ 15%
262,495
Total
2,012,465
Total Option B relative estimate of probable construction cost = $ 2,012,465
15.3. 3.9 MGD PLANT CAPACITY – OPTION C
15.3.1. SIZING CRITERIA – AVERAGE FLOW: 3.9 MGD
15.3.2. DISINFECTION PRELIMINARY DESIGN ASSUMPTIONS
• Assume a minimum CT of 450 mg-min/l for Title 22 treatment.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 58
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
• Provide 90 minute hydraulic detention time in contact tank at peak flowrates. Recognizing
that the RWCWRF is a scalping facility, use average flow or 3.9 MGD to be equal to peak
process flowrate to disinfection. Assume an additional 15% flow to the process flowrate to
consider clean-out volumes, surges, etc. Therefore assume total maximum design flow to
chlorination @ 4.5 MGD
• Contact volume @ 37, 598 cu. Ft.
• CCT channel dimensions @ 9 ft wide x 9 ft deep x 465 ft long. Use 3 pass configuration
each pass @ 155 ft. long with 2 ft freeboard. Slab with 1 foot extended footings.
• Assume a chlorine dosage of 5 mg/l
• Detention time in reclaimed water transmission line not considered for contact time
• Assume 12.5% sodium hypochlorite delivered to site
• Assume continuous RAS chlorination at 1.5 # chlorine/1,000 #s MLVSS
• Assume 12 hr HRT in AS Tanks and MLSS of 2,500 mg/l (% MLVSS @ 72%)
• Assume RAS concentration @ 7,500 mg/l
• Volume of sodium hypochlorite/day required for disinfection = 180 gpd
• Volume of sodium hypochlorite / day required for RAS bulking control = 190 gal/day
• Provide 15 days of sodium hypochlorite storage (Note: half-life of NaOCl solution is
approximately 30 days, therefore limit storage to not more than approximately 2 weeks)
• Storage volume = approximately 5,550 gals (use 8 ft diameter FRP tank approximately 20 ft
high to provide approximately 5 ft freeboard)
• Provide duty and standby chemical metering pumps for sodium hypochlorite delivery to
disinfection and RAS
• Provide protective canopy over contact tank and chemical feed facilities
15.3.3. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary design and associated cost estimates are based upon the design and
construction of a similar 3.9 MGD (approximate) water reclamation facility within the State
of California.
CHLORINE CONTACT TANK, SODIUM HYPOCHLORITE STORAGE AND CHEMICAL FEED FACILITIES FOR
TERTIARY DISINFECTION – PROBABLE CONSTRUCTION COSTS
Description Dimensions Unit Quantity Unit Price Total Price
Civil
Earthwork (Excavation, Backfill, & Grading) Est. Labor & Equipment CY 850 9 7,650
Site Improvements, Yard Piping & Restoration Approx. 8% of Total LS 1 175,000 175,000
Structural (Reinforced Concrete)
CCT SOG 159' x 33' x 2' (3 passes) CY 389 850 330,650
Walls 155' x 11' x 1' (2 Each) CY 126 975 122,850
Walls 146 x 11' x 1' (2 Each) CY 119 975 116,025
Walls 31 x 11' x 1' (2 Each) CY 26 975 25,350
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 59
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
NaOCl Storage and Feed SOG 22' x 22' x 2' CY 36 975 35,100
NaOCl Storage and Feed Containment Walls 22' x 3' x 1' (4 Each) CY 10 975 9,750
Structural (Misc. Metals)
Misc. Metals & Fabrications
Est. Labor + Supplier
Pricing LS 1 20,500 20,500
Structural (Misc. Metals)
Canopy & Support Structure (4,225 sq. ft.)
Est. Labor + Supplier
Pricing LS 1 211,250 211,250
Mechanical
Chemical Feed Equipment, piping and misc.
valves and instruments
Est. Labor + Supplier
Pricing EA 2 72,000 144,000
NaOCl Storage tank and Accessories
Est. Labor + Supplier
Pricing EA 1 18,000 18,000
Miscellaneous
Painting & Coatings
Est. Subcontractor
Pricing LS 1 52,000 52,000
Subtotal
1,268,125
Electrical & Instrumentation
E&I Power & Control Systems Average 17.5% of Total LS 1 140,480 334,976
Testing, Start-Up & Commissioning Average 1.25% of Total LS 1 10,035 23,927
General Conditions Approx. 15% of Total LS 1 120,410 287,123
Subtotal
1,914,151
Contingencies @ 15%
287,123
Total
2,201,274
Total Option C relative estimate of probable construction cost = $ 2,201,274
15.4. SUMMARY ESTIMATE OF PROBABLE CONSTRUCTION COSTS SUMMARY (BASED ON MAY 2012 DOLLARS)
TERTIARY DISINFECTION FACILITIES
Plant Capacity Estimate of Probable Construction Costs
1.3 MGD No Improvements Required
2.6 MGD $ 2,012,465
3.9 MGD $ 2,201,274
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 60
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
16. OPTION D – DECOMMISSIONING OF RWCWRF AND SBPS - OVERVIEW
16.1. ABANDON EXISTING RWCRWF PRELIMINARY SCOPE OF WORK ASSUMPTIONS
• All facilities to be abandoned are to be removed from service include all wastewater flows,
potable water, electrical power, and communications.
• All underground piping and electrical conduits & duct banks are to be abandoned and
capped in place.
• All biological solids to be removed and legally disposed of offsite.
• Mechanical and electrical demolition includes complete removal and offsite disposal of all
electrical equipment, conduit wire and other appurtenances.
• Structural demolition includes complete removal and offsite disposal of all structures
including reinforced concrete below grade structures in their entirety.
• Civil demolition includes complete removal and offsite disposal of all surface
improvements including asphalt paving, concrete drainage improvements, landscaping,
irrigation and others as required.
• Civil restoration includes importation of soils required to backfill all below grade structural
removals plus full site finish grading to ensure positive storm water drainage.
• All demolished materials to be recycled to the greatest extent possible.
16.2. ESTIMATES OF PROBABLE CONSTRUCTION COSTS
Assumptions:
• Costs based on May 2012 dollars
• Preliminary cost estimates are based upon typical abandonment, demolition and
decommissioning work performed at similar 1.3 MGD (approximate) water reclamation
facilities within the State of California.
EXISTING RWCWRF SITE - TREATMENT PLANT DECOMMISSIONING
DESCRIPTION EST. COST
DECOMMISSION (TERMINATE) PLANT PROCESS FLOW
TERMINATE SEWAGE FLOW TO RWCWRF, REDIRECT TO RSDPS - DECOMMISSIONING OF SBPS 50,000
DECOMMISSION UTILITY SERVICES
SDGE - TERMINATE ELECTRICAL SERVICE TO FACILITY 25,000
SDGE - REMOVE TRANSFORMER(S) AND ANY EXISTING SERVICE MATERIALS 75,000
DISTRICT - TERMINATE POTABLE WATER SERVICE, REMOVE METER 5,000
DISTRICT - TERMINATE TELECOMMUNICATIONS SERVICE 5,000
DECOMMISSIONING REGULATORY ADMINISTRATIVE REQUIREMENTS
DISTRICT - VERIFY IF ANY REGULATORY FILINGS ARE REQUIRED TBD
DISTRICT - COMPLETE ANY INTERNAL ACCOUNTING & ADMIN FOR WWTP TBD
DISTRICT - ANY ADDITIONAL RWCWRF CLOSURE REQUIREMENTS TBD
OTHER DISTRICT REQUIREMENTS FOR PLANT DECOMMISSIONING
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 61
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
ASSIGN OVERALL CONTINGENCY OF $250,000 250,000
SUBTOTAL - DECOMMISSIONING
$410,000
CONTINGENCY FOR DECOMMISSIONING REQUIREMENTS @ 20% $82,000
TOTAL DECOMMISSIONING $492,000
EXISTING RWCWRF SITE - TREATMENT PLANT DEMOLITION, REMOVAL AND SITE RESTORATION
DEWATER EXISTING TANKS AND BASINS
DEWATER ALL EXISTING BASINS VIA PUMPING OR EVAPORATION 50,000
CLEAN & DISPOSE OF ANY BIO-SOLIDS IN THE BASIN BOTTOMS (NOT RETURNED TO RSDPS) 200,000
DEMOLITION OF MECHANICAL, ELECTRICAL/I&C AND MISC CIVIL WORKS
DEMO & DISPOSE - STEEL BRIDGE PS (ABANDON FM TO RWCWRF IN PLACE) 10,000
DEMO & DISPOSE - HEADWORKS 15,000
DEMO & DISPOSE - ACTIVATED SLUDGE 30,000
DEMO & DISPOSE - SECONDARY CLARIFIERS 20,000
DEMO & DISPOSE - RAS PUMPING 7,500
DEMO & DISPOSE - BLOWER BUILDING MECHANICAL, ELECTRICAL/I&C, PIPING, METALS &
MISC. 25,000
DEMO & DISPOSE - TERTIARY FILTRATION FACILITIES 20,000
DEMO & DISPOSE - CHEMICAL ADDITION FACILITIES 10,000
DEMO & DISPOSE - AREA RELATED TO ORIGINAL FILTER FACILITIES 10,000
DEMO & DISPOSE - ABANDONED RO FACILITIES 15,000
DEMO & DISPOSE - CHLORINATION FACILITIES AND RELATED AREA 10,000
DEMO & DISPOSE - CHLORINE CONTACT TANK MECHANICAL 12,000
DEMO & DISPOSE - EFFLUENT PUMP STATION 20,000
DEMO & DISPOSE - ADMINISTRATION BUILDING 10,000
DEMO & DISPOSE - WATER STORAGE TANKS NEAR HEADWORKS AREA (INCL CONCRETE PADS) 25,000
DEMO & DISPOSE - MISC MECHANICAL AREAS 50,000
DEMO & DISPOSE - ELECTRICAL SWITCHGEAR, METERING & MCC'S 60,000
DEMOLITION OF ALL EXISTING STRUCTURES
CLEAN,DEMO & DISPOSE - STEEL BRIDGE PS AND ADJACENT IMHOFF TANK 165,000
CLEAN, DEMO & DISPOSE - HEADWORKS STRUCTURES 35,000
CLEAN, DEMO & DISPOSE - ACTIVATED SLUDGE TANKS 485,000
CLEAN, DEMO & DISPOSE - SECONDARY CLARIFIERS 235,000
CLEAN, DEMO & DISPOSE - RAS PUMPING STRUCTURES 25,000
CLEAN, DEMO & DISPOSE - BLOWER BUILDING 105,000
CLEAN, DEMO & DISPOSE - TERTIARY FILTRATION FACILITIES AND CANOPY 30,000
CLEAN, DEMO & DISPOSE - CHEMICAL ADDITION FACILITIES 10,000
CLEAN, DEMO & DISPOSE - AREA RELATED TO ORIGINAL FILTER FACILITIES 25,000
CLEAN, DEMO & DISPOSE - ABANDONED RO BUILDING 37,000
CLEAN, DEMO & DISPOSE - CHLORINATION FACILITIES AND RELATED AREA 35,000
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 62
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
CLEAN, DEMO & DISPOSE - CHLORINE CONTACT TANK AND CANOPY 45,000
CLEAN, DEMO & DISPOSE - EFFLUENT PUMP STATION 75,000
CLEAN, DEMO & DISPOSE - ADMINISTRATION BUILDING 275,000
CLEAN, DEMO & DISPOSE - MISC STRUCTURES 100,000
CLEAN, DEMO & DISPOSE - ELECTRICAL SWITCHGEAR, METERING & MCC'S 40,000
CIVIL IMPROVEMENTS
DEMO PAVING & DISPOSE OF ALL SURFACE IMPROVEMENTS 120,000
REGRADE SITE AFTER DEMOLITION OF EXIST FACILITIES INCLUDING IMPORT SOILS TO BACKFILL 290,000
INCORPORATE STORM WATER AND DRAINAGE MEASURES FOR PROPER CONTROL OF RUNOFF 30,000
SURFACE RESTORATION AND FINAL CIVIL IMPROVEMENTS
LANDSCAPE - LANDSCAPING & IRRIGATION OF SURFACE IMPROVEMENTS 75,000
MISC. SURFACE IMPROVEMENTS (PAVING, SIDEWALKS, ETC.) 50,000
SUBTOTAL - DEMOLITION, REMOVAL AND SITE RESTORATION $2,886,500
CONTINGENCY FOR DEMOLITION, REMOVAL AND SITE RESTORATION $577,300
TOTAL FOR DEMOLITION, REMOVAL AND SITE RESTORATION $3,463,800
GRAND TOTAL
$3,955,800
Total Option D relative estimate of probable construction costs = $3,955,800
16.3. ESTIMATE OF PROBABLE ABANDONMENT, DECOMMISSIONING, DEMOLITION AND RESTORATION COSTS
SUMMARY (BASED ON MAY 2012 DOLLARS) FOR RWCWRF
Description Estimate of Probable Total Decommissioning & Demolition Costs
Decommissioning $492,000
Demolition/Restoration $3,463,800
Grand Total $3,955,800
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 63
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Part B – Estimate of Additional Conceptual Power Consumption Costs
The following tables present conceptual estimates of additional annual power costs for each of the
management options developed by ARCADIS. Annual costs presented are in addition to existing
operational costs for the RWCWRF.
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 64
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Additional Principal Power Loads - 1.3 MGD (Option A)
Equipment Description
Total No.
of Units
Hp per
Unit
No. of
Operating Units
Total
Motor Hp
Total
BHp
Total
Run KW
Run Time per
Day (hrs)
Total KW-Hrs
per Year
Annual Power
Consumption Cost
DAF Pressurization Pump 2 15.00 1 15 11 8 24 71,885 8,626
DAF Top Scraper Drive 2 0.75 1 0.75 0.50 0.37 24 3,267 392
DAF Air Compressor 2 5.00 1 5 4.00 2.98 24 26,140 3,137
DAF Polymer Feed Pumps 2 5.00 1 5 3.75 2.80 24 24,506 2,941
Supernatant Pump (No pumping
req'd. Gravity flow to headworks) 0 0.00 0 0 0 0 0 0 0
Thickened Sludge Pump 2 15.00 1 15 26 19 8 56,636 6,796
Aerobic Digestion Blower 2 40.00 1 40 34 25 24 222,189 26,663
Digested Sludge Pumps 2 10.00 1 10 7.50 5.60 4 8,169 980
Dewatering Polymer Feed Pumps 2 7.50 1 7.5 6.75 5.04 4 7,352 882
Centrifuge Drive 1 50.00 1 50 40 30 4 43,566 5,228
Dewatered Solids Conveyors 1 5.00 1 5 4.00 2.98 4 4,357 523
Total Connected Load - - - 153 138 103 - 468,067 $56,168
Notes:
monthly
average $4,681
1- Number of units identified are additive to the existing facilities at 1.3 MDG ADWF
2- Electrical service 480/3/60 with assumed power factor @ 0.8.
3- Assumes a blended electrical service rate of $0.12 per KW-hr
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 65
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Additional Principal Power Loads - 2.6 MGD (Option B)
Equipment Description
Total No.
of Units
Hp per
Unit
No. of
Operating Units
Total
Motor Hp
Total
BHp
Total
Run KW
Run Time per
Day (hrs)
Total KW-Hrs
per Year
Annual Power
Consumption Cost
Influent Pumps 3 75.00 2 150 110 82 24 718,846 86,261
Mechanical Bar Rack 1 1.00 1 1 0.75 0.56 24 4,901 588
Grit Handling Equipment (Vortex
drive and grit pump/classifier) 2 15.00 2 30 22 16 24 143,769 17,252
Aeration Blowers 3 100.00 2 200 170 127 24 1,110,943 133,313
Anoxic Zone Mixers 8 5.00 8 40 32 24 24 209,119 25,094
MLSS Return Pump 2 25.00 2 50 41 31 24 267,933 32,152
Secondary Scum (clarifier) Pumps 2 5.00 1 5 3.70 2.76 6 6,045 725
Secondary Clarifier Drives 4 0.75 4 3 2.20 1.64 24 14,377 1,725
RAS Pumps 3 20.00 2 40 30 22 24 194,742 23,369
WAS Pumps 2 5.00 2 10 7.50 5.60 8 16,337 1,960
Flocculator Drives 2 5.00 2 10 7.50 5.60 24 49,012 5,881
Tertiary Filtration Polymer Feed
Pumps 2 5.00 2 10 7.50 5.60 24 49,012 5,881
Air Scour Compressors 2 10.00 1 10 8.00 5.97 4 8,713 1,046
Backwash Pumps 2 10.00 1 10 8.00 5.97 4 8,713 1,046
Sodium Hypochlorite Feed Pumps 4 5.00 2 10 8.50 6.34 24 55,547 6,666
Effluent Pumps 3 100.00 2 200 170 127 24 1,110,943 133,313
DAF Pressurization Pump 2 15.00 2 30 22 16 24 143,769 17,252
DAF Top Scraper Drive 2 0.75 2 1.5 1.00 0.75 24 6,535 784
DAF Air Compressor 2 5.00 1 5 4.00 2.98 24 26,140 3,137
DAF Polymer Feed Pumps 2 5.00 2 10 7.50 5.60 24 49,012 5,881
Supernatant Pump (No pumping
req'd. Gravity flow to headworks) 0 0.00 0 0 0 0 0 0 0
Thickened Sludge Pump 3 15.00 2 30 26 19 8 56,636 6,796
Aerobic Digestion Blower 3 40.00 2 80 68 51 24 444,377 53,325
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 66
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Digested Sludge Pumps 2 10.00 1 10 7.50 5.60 6 12,253 1,470
Dewatering Polymer Feed Pumps 2 7.50 1 7.5 6.75 5.04 6 11,028 1,323
Centrifuge Drive 1 50.00 1 50 40 30 6 65,350 7,842
Dewatered Solids Conveyors 1 5.00 1 5 4.00 2.98 6 6,535 784
Drainage Pumps 2 2.00 1 2 1.50 1.12 4 1,634 196
Sludge Filtrate Pumps (No pumping
req'd. Gravity flow to headworks) 0 0.00 0 0 0 0 0 0 0
Blower Room Ventilation 2 1.00 2 2 1.50 1.12 24 9,802 1,176
Miscellaneous Loads 1 1.00 1 - - 5 24 43,800 5,256
Total Connected Load - - - 1012 818 615 - 4,845,825 $581,499
Notes:
monthly
average $48,458
1- Number of units identified are additive to the existing facilities at 1.3 MDG ADWF
2- Electrical service 480/3/60 with assumed power factor @ 0.8.
3- Assumes a blended electrical service rate of $0.12 per KW-hr
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 67
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Additional Principal Power Loads - 3.9 MGD (Option C)
Equipment Description
Total No.
of Units
Hp per
Unit
No. of
Operating Units
Total
Motor Hp
Total
BHp
Total
Run KW
Run Time per
Day (hrs)
Total KW-Hrs
per Year
Annual Power
Consumption Cost
Influent Pumps 3 125.00 2 250 170 127 24 1,110,943 133,313
Mechanical Bar Rack 1 1.00 1 1 0.75 0.56 24 4,901 588
Grit Handling Equipment (Vortex
drive and grit pump/classifier) 2 15.00 2 30 22 16 24 143,769 17,252
Aeration Blowers 5 200.00 4 800 680 507 24 4,443,773 533,253
Anoxic Zone Mixers 16 5.00 16 80 66 49 24 431,307 51,757
MLSS Return Pump 4 25.00 4 100 82 61 24 535,867 64,304
Secondary Scum (clarifier) Pumps 2 5.00 1 5 3.70 2.76 6 6,045 725
Secondary Clarifier Drives 4 0.75 4 3 2.20 1.64 24 14,377 1,725
RAS Pumps 6 20.00 4 80 30 22 24 194,742 23,369
WAS Pumps 4 5.00 3 15 11 8 8 24,506 2,941
Flocculator Drives 2 5.00 2 10 7.50 5.60 24 49,012 5,881
Tertiary Filtration Polymer Feed
Pumps 2 5.00 2 10 7.50 5.60 24 49,012 5,881
Air Scour Compressors 2 10.00 1 10 8.00 5.97 4 8,713 1,046
Backwash Pumps 2 10.00 1 10 8.00 5.97 4 8,713 1,046
Sodium Hypochlorite Feed Pumps 4 7.50 2 15 12.75 9.51 24 83,321 9,998
Effluent Pumps 6 100.00 4 400 340 254 24 2,221,886 266,626
DAF Pressurization Pump 3 15.00 3 45 36 27 24 235,259 28,231
DAF Top Scraper Drive 3 0.75 3 2 1.50 1 24 9,802 1,176
DAF Air Compressor 3 5.00 2 10 8.00 5.97 24 52,280 6,274
DAF Polymer Feed Pumps 2 5.00 2 10 7.50 5.60 24 49,012 5,881
Supernatant Pump (No pumping
req'd. Gravity flow to headworks) 2 5.00 1 5 3.70 2.76 0 0 0
Thickened Sludge Pump 4 15.00 3 45 39 29 8 84,954 10,195
Aerobic Digestion Blower 4 40.00 3 120 102 76 24 666,566 79,988
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 68
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Digested Sludge Pumps 2 10.00 1 10 8 6 8 16,337 1,960
Dewatering Polymer Feed Pumps 2 7.50 1 7.5 6.75 5.04 8 14,704 1,764
Centrifuge Drive 1 50.00 1 50 40 30 8 87,133 10,456
Dewatered Solids Conveyors 2 5.00 2 10 8.50 6.34 8 18,516 2,222
Drainage Pumps 2 2.00 1 2 2 1 4 1,634 196
Sludge Filtrate Pumps (No pumping
req'd. Gravity flow to headworks) 2 5.00 1 5 4 3 0 0 0
Blower Room Ventilation 2 1.00 2 2 2 1 24 9,802 1,176
Miscellaneous Loads 1 1.00 1 - - 6 24 52,560 6,307
Total Connected Load - - - 2143 1719 1288 - 10,629,447 $1,275,534
Notes:
monthly
average $106,294
1- Number of units identified are additive to the existing facilities at 1.3 MDG ADWF
2- Electrical service 480/3/60 with assumed power factor @ 0.8.
3- Assumes a blended electrical service rate of $0.12 per KW-hr
Final Technical Memorandum
Otay Water District RWCWRF Assessment of Capital Cost
Page 69
KEH & Associates, Inc.
2173 Salk Avenue, Suite 250
Carlsbad, CA 92008
Part C – Estimate of Additional Conceptual Chemical Consumption
The following tables present conceptual estimates of additional annual chemical costs for each of the
management options developed by ARCADIS. Annual costs presented are in addition to existing
operational costs for the RWCWRF. It should be noted that the quantity of sodium hypochlorite is a
worst case type of scenario where RAS chlorination is assumed to be continuous on an annual basis.
Sodium hypochlorite costs at 1.3 MGD ADF is assumed to be 50% of projected costs for the 2.6 MGD
capacity scenario for general planning comparison.
Additional Chemical Consumption Costs – 1.3 MGD (Option A)
Chemical Additional Annual
Consumption Unit Cost Annual Cost
DAF Polymer 2,491 active lbs/year $4.00/lb active $9,965
Solids Dewatering Polymer 8,098 active lbs/year $4.00/lb active $32,394
Sodium Hypochlorite 0 gal/year $0.80/gal $0
Total Additional Annual Cost $42,359
Additional Chemical Consumption Costs – 2.6 MGD (Option B)
Chemical Additional Annual
Consumption Unit Cost Annual Cost
DAF Polymer 4,982 active lbs/year $4.00/active lb $19,929
Solids Dewatering Polymer 16,196 active lbs/year $4.00/active lb $64,784
Sodium Hypochlorite 38,690 gal/year $0.80/gal $30,952
Total Additional Annual Cost $115,665
Additional Chemical Consumption Costs – 3.9 MGD (Option C)
Chemical Additional Annual
Consumption Unit Cost Annual Cost
DAF Polymer 7,473 active lbs/year $4.00/active lb $29,894
Solids Dewatering Polymer 24,294 active lbs/year $4.00/active lb $97,176
Sodium Hypochlorite 96,360 gal/year $0.80/gal $77,088
Total Additional Annual Cost $204,158
Appendix D
Analysis of Wastewater Management
Options
04094007.0000 D - 1 April 2013
APPENDIX D: ANALYSIS OF WASTEWATER MANAGEMENT OPTIONS
This appendix provides detailed discussion and information on the analysis of wastewater management
options presented in Chapter 5 of the Wastewater Management Plan report.
5.1 Identification of Wastewater Disposal Options
The purpose of this Appendix is to present potential future wastewater treatment, disposal, and reuse
options for the District and compare capital and operational costs over the 20-year planning horizon to 2030.
The objective of the comparison is to recommend a wastewater treatment, disposal, and recycling plan to
the District based on updated planning and cost estimates for local and regional wastewater management
elements potentially affecting future costs to the District wastewater and recycled water customers.
The scope of work for the project includes multiple wastewater disposal and recycled water use variables
which result in a large matrix of about 61 alternatives presented to the District staff early in the project
implementation stage. In multiple review and discussion meetings and a collaboration and decision-making
workshop with District staff, wastewater management options were defined and synthesized into five major
feasible alternatives involving wastewater treatment, disposal, and reclamation. In considering all cost
elements for wastewater treatment and recycled water use, multiple sub-options were developed for each of
the five. The total number of cost sub-options is 18, as presented in sub-section 5.2.
All options presume continued ownership, operation, maintenance, and required expansion of the District's
existing wastewater collection system consistent with the wastewater flow projections, hydraulic modeling
analyses, and capital improvement projects discussed previously in this report. The five wastewater
management options are denoted as Options A through E, as described below.
5.1.1 Option A – Maintain Existing Wastewater Treatment Capacity at the Ralph W. Chapman Water
Recycling Facility
This wastewater management option maintains the status quo at the RWCWRF, with the exception of water
quality enhancements and potential solids handling facilities at the treatment plant location. The required
improvements to the Rancho San Diego Pump Station will be implemented. The capacity of the RWCWRF
will remain at the existing 1.3 MGD. All flows conveyed via the District's wastewater collection system in
excess of 1.3 MGD will be discharged to the San Diego Metro wastewater collection and treatment system
with the associated institutional and financial impacts.
Alternative wastewater solids handling options include onsite treatment at RWCWRF and disposal of
residuals in a landfill and continued discharge of solids to the Metro system with attendant costs. Two future
City of San Diego wastewater treatment processes and costs are evaluated in Option A. These include 1)
continued advanced primary treatment at the Point Loma WWTP and assumed continuance of an existing
waiver from the Environmental Protection Agency and 2) upgrade of the Point Loma WWTP to secondary
treatment with attendant costs and allocation of the District's fair share of the future capital and operating
costs. In a recent Recycled Water Study performed for the City of San Diego and released on May 10,
2012, alternatives to the Point Loma Upgrade were evaluated. Alternatives include diversion of wastewater
from Point Loma, increased recycled water use, and Indirect Potable Reuse (IPR) using the San Vicente
reservoir and Otay Lakes. Multiple alternatives are presented with projected capital and operating costs.
04094007.0000 D - 2 April 2013
The selected IPR alternative could result in a reduction in costs from the secondary upgrade costs allocated
to the District for those wastewater management options which include continued discharge to the Metro
System. Although it is presumed that San Diego and its participating agencies will select the most cost-
effective long-term wastewater and recycled water management solution approvable by EPA, this
management plan uses the assumption of upgrade to secondary for Point Loma, as prescribed in the
original project scope of work.
There are three recycled water treatment and use alternatives in Option A, including continued direct use for
irrigation from the RWCWRF, purchase and use of tertiary effluent from the City of San Diego SBWRP in
accordance with an existing agreement with the City, and potential purchase from a future Chula Vista
membrane bio-reactor (MBR) wastewater reclamation plant recommended at Site 3 (at Main Street and
Mace Street) in Chula Vista in the April 2012 Acquisition of Additional Wastewater Capacity Report.
Figure 5.1 below depicts the conceptual flow, treatment, wastewater discharge, and recycled water use
schematic for wastewater management Option A. Note that recycled water purchases from the San Diego
South Bay plant and a potential future Chula Vista plant are not indicated on the diagram, although these
alternatives are evaluated in the cost comparisons. For cost evaluations, there are 6 sub-options for Option
A with alternatives for purchase of recycled water, RWCWRF on-site solids handling or not, and Point Loma
WWTP upgrade or not. Sub-options are designated as A-1 through A-6, for Option A
Figure 5.1 Option A: Maintain Existing Wastewater Treatment Capacity at the Ralph W. Chapman Water Recycling Facility
5.1.2 Option B – Expand the Ralph W. Chapman Water Recycling Facility to 2.6 MGD
Option B includes the expansion of the RWCWRF from 1.3 MGD to 2.6 MGD consistent with the flow
projections discussed in Chapter 2. Flows in excess of 2.6 MGD will be conveyed to the Metro wastewater
collection and treatment system. Required improvements at the Rancho San Diego Pump Station will
continue to be funded by the District proportional to its capacity ownership and wastewater discharges to the
pump station. The District will continue to pay the existing and future unit costs associated with the Rancho
04094007.0000 D - 3 April 2013
San Diego Pump Station and the associated charges for treatment at the San Diego Point Loma WWTP
under the assumed two alternatives of advanced primary treatment and full secondary treatment if solids
handling is not constructed at the RWCWRF
Solids handling options include onsite treatment at the RWCWRF and disposal of residuals in landfill and
continued discharge to the Metro collection and treatment system. Recycled water treatment and use
alternatives include treatment and conveyance from the RWCWRF and purchase and use from the
SBWRP. Purchase and use from a future Chula Vista MBR water reclamation plant are not included since
the engineering feasibility conditions were based on the RWCWRP remaining at its current 1.3 MGD
capacity. Figure 5.2 below indicates a conceptual wastewater flow and discharge diagram from the
RWCWRF for Option B. Note that the recycled water purchase from SBWRP is not shown. There are 3
sub-options for cost evaluations from Option B, designated as B-1, B-2 and B-3.
Figure 5.2 Option B: Expand the Ralph W. Chapman Water Recycling Facility to 2.6 MGD
5.1.3 Option C – Expand the Ralph W. Chapman Water Recycling Facility to 3.9 MGD
Option C includes the expansion of the RWCWRF from 1.3 MGD to 3.9 MGD. It is recognized that the
Jamacha Basin wastewater flow projections discussed in Chapter 2 do not indicate the need for a 3.9 MGD
treatment capacity at the RWCWRF. However, the District decided to maintain the incremental modularity of
the treatment plant capacity and assume an expansion module of 2.6 MGD consistent with Option B. Flows
in excess of those treated by RWCWRF will be conveyed to the Metro System. Flows anticipated to be
treated by Metro are anticipated to be minimal only, conveyed at times of RWCWRF plant maintenance or
emergency interruptions. Required improvements at the Rancho San Diego Pump Station will continue to
be funded by the District proportional to its ownership and wastewater discharges to the pump station. The
District will continue to pay the existing and future unit costs associated with the Rancho San Diego Pump
Station and the associated charges for treatment at the Point Loma WWTP under the assumed two
alternatives of advanced primary treatment and full secondary treatment, if no solids handling facilities are
constructed at RWCWRF.
04094007.0000 D - 4 April 2013
Solids handling options include onsite treatment at the RWCWRF and disposal of residuals in a landfill and
continued discharge to the Metro System. Recycled water treatment and use alternatives include treatment
and conveyance from the RWCWRF and purchase and use from the SBWRP. Purchase and use from a
future Chula Vista MBR water reclamation plant are not assumed for Option C based on the engineering
and economic feasibility study for the Chula Vista plant. Figure 5.3 below indicates a conceptual wastewater
flow and discharge diagram for Option C. Recycled water use from SBWRP is not indicated on the diagram.
There are 3 sub-options for cost evaluation for Option C.
Figure 5.3 Option C: Expand the Ralph W. Chapman Water Recycling Facility to 3.9 MGD
5.1.4 Option D – Abandon and Demolish the Ralph W. Chapman Water Recycling Facility
Option D includes the decommissioning and demolition of the RWCWRF. All wastewater collected in the
Jamacha Basin will be sent to the Point Loma WWTP through the Rancho San Diego Pump Station.
Required improvements at the Rancho San Diego Pump Station will continue to be funded by the District
proportional to its ownership and wastewater discharges to the pump station. The District will continue to
pay the existing and future unit costs associated with the Rancho San Diego Pump Station and the
associated charges for treatment at the Point Loma WWTP under the assumed two alternatives of
advanced primary treatment and full secondary treatment.
Recycled water treatment and use alternatives are limited to purchase and use from the San Diego SBWRP
and purchase and use from a future Chula Vista MBR water reclamation plant. There are provisions in the
Otay/San Diego SBWRP agreement that require a minimum amount of recycled water to be annually
purchased from South Bay whether the District uses the recycled water or not. This provision is typically
referred to as a “Take-or-pay” requirement and was considered in determining the financial impacts to the
District's annual recycled water costs. Additionally, in the Chula Vista Acquisition of Additional Wastewater
Capacity Project, the Chula Vista consultant assumed that RWCWRF would remain at 1.3 MGD capacity
and that Chula Vista recycled water would be purchased prior to purchase of recycled water from the
SBWRP. This provision would require a modification to the existing District-SBWRP agreement. Figure 5.4
below indicates a conceptual wastewater flow and discharge diagram for Option D, with no recycled water
use shown from RWCWRF. There are 4 sub-options for cost evaluations for Option D.
04094007.0000 D - 5 April 2013
Figure 5.4 Option D: abandon and Demolish the Ralph W. Chapman Water Recycling Facility
5.1.5 OPTION E – Abandon and Demolish the Ralph W. Chapman Water Recycling Facility and Participate
in a New Joint Wastewater Treatment and Recycling Facility with San Diego County
Option E includes the decommissioning and demolition of the RWCWRF. Wastewater collected in the
Jamacha Basin will be sent to a new proposed joint wastewater treatment and recycling facility with San
Diego County or the Point Loma WWTP through the Rancho San Diego Pump Station. Required
improvements at the Rancho San Diego Pump Station will continue to be funded by the District proportional
to its capacity ownership and wastewater discharges to the pump station. The District will continue to pay
the existing and future unit costs associated with the Rancho San Diego Pump Station and the associated
charges for treatment at the San Diego Point Loma WWTP under the assumed two alternatives of advanced
primary treatment and full secondary treatment. Collection system modifications and extensions will be
required to convey existing flow to the new joint WWTP and to by- pass to the Metro System, as required.
Solids treatment at the new joint plant is assumed, since the plant process is assumed to be the same as
the Chula Vista MBR plant. The conceptual joint new WWTP has been described in the 1997 report by
Metcalf and Eddy for San Diego County entitled “Water Reclamation Facility Project Feasibility Report”. The
concept included a 10 MGD plant located near I-805 and the Sweetwater River, using an activated sludge
aeration process. For the District's Wastewater Management Plan, we have assumed an MBR plant similar
to the Chula Vista proposal with cost estimates the same as the Chula Vista plant for equivalent capacity.
Recycled water treatment and use alternatives include production and delivery from a new joint WWTP,
purchase and use from the existing SBWRP, and purchase and use from a future Chula Vista MBR water
reclamation plant. Figure 5.5 below indicates a conceptual wastewater flow and discharge diagram for
Option E. There are two sub-options for cost evaluation for Option E.
04094007.0000 D - 6 April 2013
Figure 5.5 Option E: abandon the Ralph W. Chapman Water Recycling Facility and Participate in a New Joint WWTP and Recycling Project with San Diego County
5.2 Economic Evaluations of Wastewater Disposal and Recycled Water Use Options
An initial project challenge involved the determination of key cost factors associated with each of the five
wastewater management options described above. Cost factors were broken into wastewater treatment
components and recycled water components. Table 5-1 indicates the wastewater treatment cost elements;
including costs for solids handling, expansion, and decommissioning of the RWCWRF; existing, new
capacity, and Point Loma WWTP upgrade costs to Metro; and the District's share of a proposed joint San
Diego County/Otay new wastewater treatment and recycled water facility. Wastewater treatment costs
include capital and annual operation and maintenance costs.
Table 5-1. Wastewater Treatment Cost Components for Different Management Options
Wastewater Management Option A B C D E
RWRWRF
• Expansion 0 $ $ 0 0
• On-Site Solids Handling $ $ $ 0 0
• Decommissioning 0 0 0 $ $
Metro System Capacity
• Existing Charge (w/o on-site solids handling) $ $ $ $ 0
• New Capacity Charge (w/o on-site solids handling) 0 $ $ $ 0
• Point Loma WWTP Upgrade (w/o on-site solids
handling)
$ $ $ $ 0
New County/Otay WWTP 0 0 0 0 $
Notes: $ = capital and operational costs exist for this option. 0 = no costs exist for this option.
04094007.0000 D - 7 April 2013
Table 5-2 indicates the recycled water sources which exist for each of the wastewater management options.
There exist four potential sources of recycled water under the five options, including the RWCWRF, the
Metro SBWRP, a new potential Chula Vista MBR WRP, and a new potential joint County/Otay WWTP. Cost
elements allocated for recycled water include costs to purchase each unit of recycled water from the
SBWRP and the new Chula Vista WRP and capital costs for new booster stations and pipelines to deliver
water from the proposed two new plants to the District's recycled water distribution system. Option E only
assumes purchase of recycled water from the SBWRP and the new County/District plant.
Table 5-2. Recycled Water Sources Under Different Management Options
Wastewater Management Option A B C D E
RWCWRF X X X 0 0
SBWRP X X X X X
New Chula Vista WRP X 0 0 X 0
New County/District WWTP 0 0 0 0 X
Notes: X = recycled water provided to Otay for this option. 0 = no recycled water for this option.
In consideration of the key variables for evaluating capital and annual O&M costs for Options A through E,
sub-options have been identified to compare present worth costs. Sub-options are combinations of
wastewater treatment, disposal, and recycled water purchase variables. The matrix of options and sub-
options included the following:
Option A: Six total sub-options.
(1) RWCWRF on-site solids handling, no Point Loma upgrade, Chula Vista RCW purchase
(2) RWCWRF on-site solids handling, no Point Loma upgrade, no Chula Vista RCW purchase
(3) RWCWRF no on-site solids handling, Point Loma upgrade, Chula Vista RCW purchase
(4) RWCWRF no on-site solids handling, Point Loma upgrade, no Chula Vista RCW purchase
(5) RWCWRF no on-site solids handling, no Point Loma upgrade, Chula Vista RCW purchase
(6) RWCWRF no on-site solids handling, no Point Loma upgrade, no Chula Vista RCW purchase
Option B: Three total sub-options.
(1) RWCWRF on-site solids handling, no Point Loma upgrade
(2) RWCWRF no on-site solids handling, Point Loma upgrade
(3) RWCWRF no on-site solids handling, no Point Loma upgrade
Option C: Three total sub-options.
(1) RWCWRF on-site solids handling, no Point Loma upgrade
(2) RWCWRF no on-site solids handling, Point Loma upgrade
(3) RWCWRF no on-site solids handling, no Point Loma upgrade
Option D: Four total sub-options (Metro discharge).
(1) No RWCWRF, Point Loma upgrade, Chula Vista RCW purchase
(2) No RWCWRF, no Point Loma upgrade, Chula Vista RCW purchase
04094007.0000 D - 8 April 2013
(3) No RWCWRF, Point Loma upgrade, no Chula Vista RCW purchase
(4) No RWCWRF, no Point Loma upgrade, no Chula Vista RCW purchase
Option E: Two sub-options (new County/District WWTP).
(1) No RWCWRF, Point Loma upgrade
(2) No RWCWRF, no Point Loma upgrade
A matrix indicating the sub-options associated with each major wastewater management option is included
below as table 5-3.
Table 5-3. Matrix of Sub-Options Evaluated
Wastewater Management Option
Recycled Water from SBWRP Only No Chula Vista Purchases
Recycled Water from Chula Vista WRF Only No SBWRP Purchases
No Point
Loma WWTP Upgrade
Point Loma
WWTP Upgrade
No Point
Loma WWTP Upgrade
Point Loma WWTP
Upgrade
A Onsite sludge A-2 -- A-1 --
No onsite sludge A-6 A-4 A-5 A-3
B Onsite sludge B-1 -- -- --
No onsite sludge B-3 B-2 -- --
C Onsite sludge C-1 -- -- --
No onsite sludge C-3 C-2 -- --
D D-4 D-3 D-2 D-1
E (onsite sludge) E-2 E-1
5.3 Cost Estimates for Expansion and Demolition of the RWCWRF
The District treats raw wastewater and produces recycled water at the RWCWRF and purchases additional
recycled water from the SBWRP. Detailed capital cost estimates have been prepared associated with
upgrading, expanding, and decommissioning the RWCWRF under Options A through D, based on site
visits, review of construction plans, and layout of new facilities. A site map of the RWCWRF with suggested
new locations of processes required for upgrade and expansion for Options A through C is included as
Appendix B. Option A maintains the RWCWRF at its current nominal ADWF of 1.3 MGD and adds solids
handling facilities. Option B expands the RWCWRF to a nominal ADWF of 2.6 MGD, adds solids handling
facilities, and adds tertiary filtration and chlorination, including a larger chlorine contact chamber to preclude
the recycled water pipeline from meeting CA Title 22 requirements for contact time. Option C expands the
RWCWRF to 3.9 MGD, adds solids handling facilities, and adds tertiary filtration and chlorination. Option D
decommissions the RWCWRF, restores the site, and relies on other agencies to treat District wastewater
and provide required recycled water for irrigation.
Capital cost estimates provided are expressed in May 2012 dollars based on the Los Angeles ENR
Construction Cost Index of 10285. No allowances for inflation or financing costs have been included. Cost
estimates are prepared in accordance with a Class 3 estimate of the Association for the Advancement of
Cost Engineering International (AACEI). A Class 3 estimate may be expected to fall within the range of
+25%/-15% of actual costs. For planning studies such as this, capital cost estimates are generally Class 5,
having a much broader range of predicted accuracy for actual costs. The higher class estimate provides
more detailed analysis of treatment process component size and costs that will add value to the planning
04094007.0000 D - 9 April 2013
and budgeting process. General contingencies were applied to the estimates for each of the treatment
processes evaluated. The cost estimates shown are related only to costs that would be included in a
general contractor’s bid for related construction work and do not include District administration, engineering,
third party construction management, environmental documentation, and other non-contractor costs. Actual
project final costs will depend on the type of project delivery selected by the District, actual labor and
material costs, competitive market conditions, actual site conditions, final project scope, implementation
schedule, and other factors.
The RWCWRF Assessment of Capital Costs Report, included in Appendix C, is very detailed and organized
by treatment process at the RWCWRF. Individual treatment processes have component sizing criteria,
dimensions, units for costing, quantities, unit prices, and total price. In the detailed report, costs for Options
A through C are grouped under each treatment process category. A summary of total capital costs for 15
components of the RWCWRF solids handling and improved disinfection upgrade and expansion Options A
through C is shown in the Table 5-4 below.
Table 5-4. Summary of RWCWRF Conceptual Capital Costs for Options A, B and C in millions
Treatment Process
Option A –
Maintain RWCWRF at
1.3MGD
Option B –
Expand RWCWRF to
2.6MGD
Option C –
Expand RWCWRF to
3.9MGD
Influent Pump Station 0 1.132 1.293
Headworks & Grit Removal 0 2.043 2.196
Aeration Basins 0 3.333 5.897
Secondary Clarifiers 0 1.964 3.582
RAS/WAS Pump Station 0 0.820 1.491
Scum Pump Station 0 0.173 0.173
Effluent Pump Station 0 0.788 1.542
Administration Building 0 0 1.040
Blower & Electrical Building 0 2.052 2.488
Aerobic Digestion 1.462 2.760 3.936
Digested Sludge Pump St. 0.121 0.229 0.331
WAS Thickening 0.848 1.579 2.309
Sludge Dewatering
Centrifuge
0.915 0.915 1.748
Tertiary Filters
(+Flocculation)
0 0.648 1.296
NaOCl Storage, Pumping,
and
Chlorine Contact Tank
0
2.012
2.201
Total 3.346 20.450 31.524
5.3.1 Estimate of Additional RWCWRF Power Loads and Chemical Costs
In addition to capital cost estimates for the RWCWRF components of Options A through C, specific
elements of annual operating costs have been projected for the three options. Key elements of operational
04094007.0000 D - 10 April 2013
cost include additional power cost and additional chemical costs. Added chemical and power costs are
assumed to be attributed to new solids handling facilities for Option A. Solids handling operational costs for
Option B are assumed to be twice the annual costs for Option A. Solids handling costs for Option C are
assumed to be three times annual costs for Option A. Additional salary, benefit, and admin costs have not
been estimated. Power cost per KWH assumes a blended rate of $0.12. These values are incorporated into
Table 5-5 below.
Table 5-5. Summary of RWCWRF Annual Added Operational Costs for Options A, B and C
O & M Component
Option A –
Maintain
RWCWRF at
1.3MGD
Option B –
Expand
RWCWRF to
2.6MGD
Option C –
Expand
RWCWRF to
3.9MGD
Additional KWHs per year 468,067 4,845,825 10,629,447
Annual added power cost $56,168 $581,499 $1,275,534
DAF polymer annual cost $9,965 $19,929 $29,894
Solids dewatering polymer $32,394 $64,784 $97,176
Sodium Hypochlorite cost $0 $30,952 $77,088
5.3.2 Estimate of Cost to Decommission and Abandon the RWCWRF and Steel Bridge Pump Station
The Appendix C report also includes the estimated costs to decommission the RWCWRF and the Steel
Bridge Pump Station, which pumps raw wastewater to the RWCWRF. Costs are expressed as two primary
elements: decommissioning and demolition/restoration. These costs are associated with wastewater
management Option D. Decommissioning is estimated to cost $492,000. Demolition and restoration have a
combined estimated cost of $3,463,800. The collective cost is $3,955,800.
The total estimated capital and operational costs presented above for Options A through D have been
combined with other cost elements associated with meeting the projected wastewater treatment and
recycled water needs of the District to year 2030, provided in Chapters 2 and 4 of this wastewater
management plan.
5.4 Wastewater Treatment and Recycled Water Use Cost Modeling for Options A through E.
Based on the Otay wastewater flow projections presented in Chapter 2 and the recycled water use
projections presented in Chapter 4, a major objective of this wastewater management plan is to compare
projected capital and operating costs for the five wastewater management options to develop a
recommended District course of action for the future. To facilitate comparison of costs, the consultant team
prepared a detailed Excel workbook of individual, linked spreadsheets for each option. Linking spreadsheets
allows changes in financial assumptions to automatically recalculate anticipated costs. The comparative
cost approach was present worth, using the sum of capital costs in 2012 dollars and today’s value of annual
operating and maintenance costs from 2015 through 2030 (16 years). Both capital and operating and
maintenance costs for wastewater treatment and recycled water purchase were separately calculated and
summed to a total present worth value. The goal of the present worth analysis was to determine the
predicted values for all five options and sub options (on-site solids handling and Metro Point Loma treatment
04094007.0000 D - 11 April 2013
process) and compare results. The Excel workbook is included as Appendix D on a CD contained in a
pocket at the end of the hard copy of this report.
A common set of assumptions was developed for all five options, which are included as variables in the
Excel workbook for future “what-if” scenario evaluation. For initial economic analyses in this study, the list of
assumptions indicated in Table 5-6 was used. References for individual cost values are indicated in the
table footnotes. Assumptions for both wastewater discharge and recycled water purchase are shown.
Table 5-6. Economic Cost Assumptions for All Options
SBWRF, Chula Vista, Joint Plant Recycled Water Purchase Rate (per AF) [1] $350
2012 Metro County Wastewater Discharge Rate (per MGD) [2,6] $3,089,634
Additional Metro Capacity Cost (per MGD) [3] $30,000,000
PLWWTP Upgrade Capital Cost [4] $1,161,174,957
Otay WD Capital Cost for PLWWTP Upgrade (0.513%) [4] $5,956,828
PLWWTP Upgrade O&M Cost [4] $37,497,060
Otay WD Annual O&M Cost for PLWWTP Upgrade (per MGD) [4] $156,238
MWD/SDCWA Rebate (per AF) [5] $385
[1] Based on Recycled Purchase Agreement between City of San Diego and Otay WD.
[2] Based on Metro Discharge Agreement between City of San Diego and Otay WD.
[3] $22 Million paid to Metro, $8 Million paid to the County. A one-time up-front cost for buying capacity in these systems.
[4] Point Loma WWTP Secondary Treatment Upgrade Costs at Different Capacities from The City of San Diego's Wastewater Master Plan and Recycled Water Study, May 2012
[5] $185/AF is received from MWD; $200/AF comes from the SDCWA.
[6] Lump sum of Metro Cost and County cost based on recent District invoices.
In addition to the above assumed cost factors, it was necessary to make an assumption about projected
value of money (assumed to be increasing at 2 percent per year) for determining the present worth of
operating and maintenance expense. This value is a workbook variable that can be modeled, as desired.
The potential new Chula Vista MBR water recycling plant was assumed to be available for purchase of
recycled water for Options A and D at a price of $350 per acre-foot per the 2012 feasibility study for the City
of Chula Vista. The study assumed that the RWCWRF would not be expanded and that Otay would
purchase recycled water from Chula Vista prior to purchase from the Metro SBWRF. This provision would
require an amendment to the existing Metro/Otay agreement for recycled water purchase from the SBWRP.
5.4.1 Present Worth Costs for Option A
For all options, wastewater discharge present worth costs are based on projected wastewater discharge
rates, facilities used, and facility and contract costs over the planning horizon (2030). For all options,
recycled water purchase costs are based on projected recycled water needs, production sources,
production amounts, and facility and contract costs over the planning horizon. In the sections that follow, the
bases for costs for each of the 18 sub-options have been indicated separately as wastewater discharge
amounts and costs and recycled water use amounts and costs. Wastewater discharge and recycled water
use volumes are indicated for five-year planning horizons from 2010 (actual) through 2030, consistent with
District projections indicated previously. This subsection of the report presents individual O&M and capital
cost elements, assumptions for present worth analyses, and present worth calculation results for the six
sub-options associated with Option A.
04094007.0000 D - 12 April 2013
Table 5-7 indicates projected District wastewater flows and total projected Metro System discharge based
on a treatment flow of 1.0 MGD by the RWCWRF per sub-options A-2, A-4, and A-6. Additionally, the table
indicates recycled water use projections, RWCWRF production, SBWRP needs, and SBWRP required
annual purchase under the existing contract "take or pay" provision for minimum annual purchase amounts.
The required purchase is used for determining annual costs to the District, even though the District may not
need nor take the amount indicated in the table as the annual contract amount. Table 5-8 indicates the
same formation in terms of acre-feet per year. For the remaining options and associated sub-options for B-
E, only the MGD units tables will be shown, since it is easy to convert to acre-feet per year (AFY) using
1120 AFY equals 1 MGD.
Table 5-7. Option A – Projected Wastewater Discharge and Recycled Water Production Rates (MGD) (Sub-options 2, A-4, A-6)
Wastewater Discharge 2010 2015 2020 2025 2030
Total Metro Discharge [1] 0.84 0.93 0.97 1.09 1.15
Total District WW Flow 1.84 1.93 1.97 2.09 2.15
Recycled Water
RWCWRF Production [2] 1.00 1.00 1.00 1.00 1.00
Recycled Demand [3] 3.64 3.93 4.46 5.18 6.07
SBWRP Purchase 2.64 2.93 3.46 4.18 5.07
SBWRP Annual Contract Amount [4] 2.98 4.11 4.74 5.14 -
[1] Otay WD has a 1.231 MGD Metro capacity.
[2] Producing 77% of Total RWCWRF Capacity per existing condition.
[3] Based on Recycled Water Memo 06-08-12.
[4] Based on Recycled Purchase Agreement between City of San Diego and the District.
Table 5-8. Option A – Projected Wastewater Discharge and Recycled Water Production Rates (AFY) (Sub-options A A-4, A-6)
Wastewater Discharge 2010 2015 2020 2025 2030
Total Metro Discharge [1] 941 1,042 1,086 1,221 1,288
Total District WW Flow 2,061 2,162 2,206 2,341 2,408
Recycled Water
RWCWRF Production [2] 1,120 1,120 1,120 1,120 1,120
Recycled Demand [3] 4,077 4,402 4,995 5,802 6,798
SBWRP Purchase 2,957 3,282 3,875 4,682 5,678
SBWRP Annual Contract Amount [4] 3,338 4,604 5,312 5,758 -
[1] Otay WD has a 1.231 MGD Metro capacity. [2] Producing 77% of Total RWCWRF Capacity per existing condition. [3] Based on Recycled Water Memo 06-08-12. [4] Based on Recycled Purchase Agreement between City of San Diego and the District.
Options A and D have an alternative involving purchase of recycled water from a new Chula Vista MBR
plant, if that plant is constructed per Chula Vista’s Acquisition of Additional Wastewater Capacity Project
Report dated April 2012. This report recommends the Membrane Bioreactor (MBR) treatment process at a
specified location approximately 8,000 feet from existing Otay recycled water system. The plant is proposed
to be constructed in three equal phases of 2 MGD capacity each to a maximum of 6 MGD. This
management plan assumes that recycled water will be available to Otay beginning in 2020 at $350 per acre-
foot. This plan also assumes that the requirement to hold RWCWRF to 1.3 MGD capacity is enforced and
04094007.0000 D - 13 April 2013
that Chula Vista recycled water may be purchased only under Option A and D. For these two options,
present worth costs are computed for both with Chula Vista purchases and without Chula Vista purchases.
Table 5-9 indicates the projected recycled water purchases from 2010-2030 from the SBWRP and the
proposed Chula Vista MBR plant used for calculations in sub-options A-1, A-3, and A-5. The Chula Vista
recycled water availability assumption is 2 MGD in 2020, 4MGD in 2025, and 6 MGD in 2030. Purchases
from Chula Vista will reduce the District’s recycled water need from the SBWRP to 0.18 MGD in 2025 and
zero in 2030.
Table 5-9. Option A-1 – Projected Recycled Water Production Rates from SBWRP and Chula Vista (Sub-options A-1, A-3, A-5)
Recycled 2010 2015 2020 2025 2030
Chula Vista Available [1] - - 2.00 4.00 6.00
Chula Vista Purchase - - 2.00 4.00 5.07
SBWRP Purchase 2.64 2.93 1.46 0.18 -
[1] Based on City of Chula Vista's Acquisition of Additional Wastewater Capacity Project Final Report April 2012
Table 5-10 indicates projected annual O&M costs and capital costs for sub-option A-1, which includes
recycled water purchases from Chula Vista. Individual line items for O&M and capital costs are shown for
both wastewater treatment and recycled water. The table assumes a continuing rebate from MWD and the
SDCWA for an assumed annual production of 1,120 acre-feet from RWCWRF. The rebate amount offsets a
portion of annual costs. Footnotes in the table indicate sources of information for specific cost elements
associated with a specific sub-option. Capital costs included in the lower portion of the table are for solids
handling facilities at RWCWRF and a new 6 MGD pump station and pipeline to deliver recycled water to the
District’s existing distribution system. Values in Table 5-10 are used to compute present worth costs shown
in subsequent tables.
Table 5-11 shows the resulting calculation of present worth costs for the sum of wastewater treatment and
disposal and recycled water use for sub-option A-1. The resulting calculation indicates a combined present
worth of about $35M.
04094007.0000 D - 14 April 2013
Table 5-10. Option A-1 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase Chula Vista) $ - $ - $784,000 $1,568,000 $1,987,440
RW Cost (purchase SBWRF) $1,034,880 $1,148,560 $572,320 $70,560 $ -
MWD/SDCWA Rebate $ (431,200) $ (431,200) $(431,200) $(224,000) $(224,000)
Metro Discharge Cost $2,595,293 $ - $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
On-Site Solids Handling Power Cost [1] $ - $56,168 $56,168 $56,168 $56,168
On-Site Solids Handling Chemical Cost [1] $ - $42,359 42,359 $42,359 $42,359
Power Cost [2] $90,100 $90,100 $90,100 $90,100 $90,100
Chemical Cost [1] $ - $ - $ - $ - $ - Collection/Treatment/Operation
[2] $354,682 $354,682 $354,682 $354,682 $354,682
RWCWRF operating cost $199,211 $199,211 $199,211 $199,211 $199,211
Capital Costs 2010 2015 2020 2025 2030
On-Site Solids Handling Cost [1] $ - $3,345,620 $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
Chula Vista Pump Station/Pipeline [3] $ - $ - $3,960,000 $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Based on Recycled and Sewer Cost Spreadsheet. [3] 6 MGD Pump Station (600 hp), 8000 LF of Pipeline.
Similar tables are used to present annual O&M and capital costs for the sub-options A-2 through A-6, as
well as resulting present worth cost calculations. Tables 5-12 and 5-13 provide similar cost data for sub-
option A-2, which includes the capital costs for on-site solids handling at RWCWRF. Resulting present worth
costs are about $37 M. Tables 5-14 and 5-15 indicate results of cost projections for sub-option A-3. This
sub-option presumes contribution by the District to the cost of a Point Loma WWTP upgrade or a Metro
alternative which achieves requirements for a continued waiver for advanced primary ocean discharge from
the US Environmental Protection Agency. Both capital and increased annual O&M costs are included. The
calculated present worth for this sub-option is $84.6 M. Tables 5-16 and 5-17 indicate cost assumptions and
calculations for sub-option A-4. This sub-option also includes Point Loma upgrade costs. Total present
worth costs are $87M. Tables 5-18 and 5-19 provide costs for sub-option A-5. Present worth is $77M.
Results for sub-option A-6 are provided in Tables 5-20 and 5-21. The resulting present worth cost is $79.3
M. Option A present worth costs are generally less than those for all other sub-options for Option B through
E. On-site solids handling options are less costly than no on-site solids handling. Purchase of recycled water
from Chula Vista shows minor cost improvement over continued purchase from SBWRP due to the take or
pay provision.
04094007.0000 D - 15 April 2013
Table 5-11. Option A-1 – Present Worth of Wastewater and Recycled Water Costs
Present Worth
(Wastewater) 2010 2015 2020 2025 2030
Interest Rate
2% 2% 2% 2%
Uniform Amount per Interest Period
742,520 $742,520 $742,520 $742,520
Factor Table
4.7135 4.7135 4.7135 1.0000
O&M Present Worth $3,499,869 $3,499,869 $3,499,869 $742,520
Capital Costs $3,345,620 $ - $ - $ -
Present Worth Amount
$6,845,489 $3,499,869 $3,499,869 $742,520
Wastewater Total $14,587,746
Present Worth (Recycled) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $717,360 $925,120 $1,414,560 $1,763,440
Factor Table
4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$3,381,276 $4,360,553 $6,667,529 $1,763,440
Capital Costs $ - $3,960,000 $ - $ --
Present Worth Amount $3,381,276 $8,320,553 $6,667,529 $1,763,440
Recycled Total $20,132,798 Total $34,720,545
Table 5-12. Option A-2 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,987,440
MWD/SDCWA Rebate $(431,200) $ (431,200) $(431,200) $(224,000) $(224,000)
Metro Discharge Cost $2,595,293 $- $ - $ - $
PLWWTP Upgrade Cost $ - $- $ - $ - $ -
On-Site Solids Handling Power Cost [1] $ - $56,168 $56,168 $56,168 $56,168
On-Site Solids Handling Chemical Cost [1] $ - $42,359 $42,359 42,359 $42,359
Power Cost [2] $90,100 $90,100 $90,100 $90,100 $90,100
Chemical Cost [1] $ - $ - $ - $ - $ - Collection/Treatment/Operation
[2] $354,682 $354,682 $354,682 $354,682 $354,682
RWCWRF Operating Cost [2] $ 199,211 $199,211 $199,211 $199,211 $199,211
Capital Costs 2010 2015 2020 2025 2030
On-Site Solids Handling Cost [1] $ - $3,345,620 $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Based on Recycled and Sewer Cost Spreadsheet.
04094007.0000 D - 16 April 2013
Table 5-13. Option A-2 – Present Worth of Wastewater and Recycled Water Costs
Present Worth
(Wastewater) 2010 2015 2020 2025 2030
Interest Rate
2% 2% 2% 2%
Uniform Amount per
Interest Period $742,520 $742,520 $742,520 $742,520
Factor Table
4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$3,499,869 $3,499,869 $3,499,869 $742,520
Capital Costs $3,345,620 $- $ - $ - Present Worth
Amount $6,845,489 $3,499,869 $3,499,869 $742,520
Wastewater Total $14,587,746
Present Worth (Recycled) 2010 2015 2020 2025 2030
Interest Rate
2% 2% 2% 2%
Uniform Amount per Interest Period
$1,180,200 $1,428,000 $1,791,300 $1,763,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $5,562,873 $6,730,878 $8,443,293
$1,763,440
Capital Costs $ - $ - $ - $ - Present Worth
Amount $5,562,873 $6,730,878 $8,443,293
$1,763,440
Recycled Total $22,500,483
Total $37,088,230
04094007.0000 D - 17 April 2013
Table 5-14. Option A-3 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase Chula Vista) $ - $ - $784,000 $1,568,000 $1,987,440
RW Cost (purchase SBWRF) $1,034,880 $1,148,560 $572,320 $70,560 $ -
MWD/SDCWA Rebate $(431,200) $(431,200) $ (431,200) $(224,000) $(224,000)
Metro Discharge Cost $2,595,293 $2,873,360 $2,996,945 $3,367,701 $3,553,079
PLWWTP Upgrade Cost $ - $ - $151,551 $170,299 $179,673
On-Site Solids Handling Power Cost [1] $ - $ - $ - $ - $ -
On-Site Solids Handling Chemical Cost [1] $ - $ - $ - $ - $ -
Power Cost [2] $90,100 $90,100 $90,100 $90,100 $90,100
Chemical Cost [1] $ - $ - $ - $ - $ -
Collection/Treatment/Operation [2] $354,682 $354,682 $354,682 $354,682 $354,682
RWCWRF operating cost $199,211 $199,211 $199,211 $199,211 $199,211
Capital Costs 2010 2015 2020 2025 2030
On-Site Solids Handling Cost [1] $ - $ - $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $5,956,828 $ - $ - Chula Vista Pump
Station/Pipeline [3] $ - $ - $3,960,000 $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Based on Recycled and Sewer Cost Spreadsheet. [3] 6 MGD Pump Station (600 hp), 8000 LF of Pipeline. Table 5-15. Option A-3 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2010 2015 2020 2025 2030
Interest Rate
2% 2% 2% 2%
Uniform Amount per Interest Period
$3,517,353 $3,792,489 $4,181,993 $4,376,746
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $16,579,042 $17,875,896 $19,711,826 $4,376,746
Capital Costs $ - $5,956,828 $ - $ -
Present Worth Amount $16,579,042 $23,832,723 $19,711,826 $ 4,376,746
Wastewater Total $64,500,337
Present Worth (Recycled) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $717,360 $925,120 $1,414,560 $1,763,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$3,381,276 $4,360,553 $6,667,529 $1,763,440
Capital Costs $ - $3,960,000 $ - $ -
Present Worth Amount $3,381,276 $8,320,553 $6,667,529 $1,763,440
Recycled Total $20,132,798 Total $84,633,135
04094007.0000 D - 18 April 2013
Table 5-16. Option A-4 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,987,440
MWD/SDCWA Rebate $(431,200) $(431,200) $(431,200) $(224,000) $(224,000)
Metro Discharge Cost $2,595,293 $2,873,360 $2,996,945 $3,367,701 $3,553,079
PLWWTP Upgrade Cost $ - $ - $151,551 $170,299 $79,673
On-Site Solids Handling Power Cost [1] $ - $ - $ - $ - $ -
On-Site Solids Handling Chemical Cost [1] $ - $ - $ - $ - $ -
Power Cost [2] $90,100 $90,100 $90,100 $90,100 $90,100
Chemical Cost [1] $ - $ - $ - $ - $ - Collection/Treatment/Operation
[2] $354,682 $354,682 $354,682 $354,682 $354,682
RWCWRF Operating Cost [2] $199,211 $199,211 $199,211 $199,211 $199,211
Capital Costs 2010 2015 2020 2025 2030
On-Site Solids Handling Cost [1] $ - $ - $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $5,956,828 $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Based on Recycled and Sewer Cost Spreadsheet.
Table 5-17. Option A-4 – Present Worth of Wastewater and Recycled Water Costs
Present Worth
(Wastewater) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $3,517,353 $3,792,489 $4,181,993 $4,376,746
Factor Table
4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$16,579,042 $17,875,896 $19,711,826 $4,376,746
Capital Costs $ - $5,956,828 $ - $ -
Present Worth Amount $16,579,042 $23,832,723 $19,711,826 $4,376,746
Wastewater Total $64,500,337
Present Worth (Recycled) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $1,180,200 $1,428,000 $1,791,300 $1,763,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$5,562,873 $6,730,878 $8,443,293 $1,763,440
Capital Costs
$ - $ - $ - $ -
Present Worth Amount $5,562,873 $6,730,878 $8,443,293 $1,763,440
Recycled Total $22,500,483 Total $87,000,820
04094007.0000 D - 19 April 2013
Table 5-18. Option A-5 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase Chula Vista) $ - $ - $784,000 $1,568,000 $1,987,440
RW Cost (purchase SBWRF) $1,034,880 $1,148,560 $572,320 $70,560 $ -
MWD/SDCWA Rebate $(431,200) $(431,200) $(431,200) $(224,000) $(224,000)
Metro Discharge Cost $2,595,293 $2,873,360 $2,996,945 $3,367,701 $3,553,079
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
On-Site Solids Handling Power Cost [1] $ - $ - $ - $ - $ -
On-Site Solids Handling Chemical Cost [1] $ - $ - $ - $ - $ -
Power Cost [2] $90,100 $90,100 $90,100 $90,100 $90,100
Chemical Cost [1] $ - $ - $ - $ - $ - Collection/Treatment/Operation
[2] $354,682 $354,682 $354,682 $354,682 $354,682
RWCWRF operating cost $199,211 $199,211 $199,211 $199,211 $199,211
Capital Costs 2010 2015 2020 2025 2030
On-Site Solids Handling Cost [1] $ - $ - $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $ - $ - $ - Chula Vista Pump
Station/Pipeline [3] $ - $ - $3,960,000 $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12. [2] Based on Recycled and Sewer Cost Spreadsheet. [3] 6 MGD Pump Station (600 hp), 8000 LF of Pipeline.
Table 5-19. Option A-5 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per Interest Period $3,517,353 $3,640,938 $4,011,694 $4,197,072
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $16,579,042 $17,161,562 $18,909,121 $4,197,072
Capital Costs
$ - $ - $ - $ -
Present Worth Amount $16,579,042 $17,161,562 $18,909,121 $4,197,072
Wastewater Total $56,846,797
Present Worth (Recycled) 2010 2015 2020 2025 2030
Interest Rate
2% 2% 2% 2%
Uniform Amount per Interest Period
$717,360 $925,120 $1,414,560 $1,763,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $3,381,276 $4,360,553 $6,667,529 $1,763,440
Capital Costs $ - $3,960,000 $ - $ -
Present Worth Amount
$3,381,276 $8,320,553 $6,667,529 $1,763,440
Recycled Total $20,132,798 Total $76,979,595
04094007.0000 D - 20 April 2013
Table 5-20. Option A-6 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,987,440
MWD/SDCWA Rebate $(431,200) $(431,200) $(431,200) $(224,000) $(224,000)
Metro Discharge Cost $2,595,293 $2,873,360 $2,996,945 $3,367,701 $3,553,079
PLWWTP Upgrade Cost $ - $ - $ - $ - $ - On-Site Solids Handling Power Cost [1] $ - $ - $ - $ - $ -
On-Site Solids Handling Chemical Cost [1] $ - $ - $ - $ - $ -
Power Cost [2] $90,100 $90,100 $90,100 $90,100 $90,100
Chemical Cost [1] $ - $ - $ - $ - -$ - Collection/Treatment/Operation
[2] $354,682 $354,682 $354,682 $354,682 $354,682
RWCWRF Operating Cost [2] $199,211 $ 199,211 $199,211 $199,211 $199,211
Capital Costs 2010 2015 2020 2025 2030
On-Site Solids Handling Cost [1] $ - $ - $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Based on Recycled and Sewer Cost Spreadsheet.
Table 5-21. Option A-6 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $3,517,353 $3,640,938 $4,011,694 $4,197,072
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$16,579,042 $17,161,562 $18,909,121 $4,197,072
Capital Costs
$ - $ - $ - $ -
Present Worth Amount
$16,579,042 $17,161,562 $18,909,121 $4,197,072
Wastewater Total $56,846,797
Present Worth
(Recycled) 2010 2015 2020 2025 2030
Interest Rate
2% 2% 2% 2%
Uniform Amount per Interest Period
$1,180,200 $1,428,000 $1,791,300 $1,763,440
Factor Table
4.7135 4.7135 4.7135 1.0000
O&M Present Worth $5,562,873 $6,730,878 $ 8,443,293 $1,763,440
Capital Costs $ - $ - $ - $ - Present Worth
Amount $5,562,873 $6,730,878 $8,443,293 $1,763,440
Recycled Total $22,500,483
Total $79,347,280
04094007.0000 D - 21 April 2013
5.4.2 Present Worth Costs for Option B
Option B includes expansion of the RWCWRF to 2.6 MGD. The wastewater discharge and recycled water
use projections indicated in Table 5-22 are different than projections for Option A. This table is for the on-
site solids handling sub-option, which negates Metro discharge. The increased RWCWF capacity reduces
the need to purchase as much recycled water from the SBWRP. There are three sub-options for this
alternative. Tables 5-23 and 5-24 provide cost projections and present worth calculations for sub-option B-1.
The present worth is $82.7 M. Sub-options B-2 and B-3 are for the no on-site solids handling facilities, which
result in higher present worth costs. Tables 5-25 and 5-26 indicate cost values for sub-option B-2 at a total
present worth of $93 M. Tables 5-27 and 5-28 indicate similar results for sub-option B-3. The present worth
calculation difference is due to the impact of the Point Loma WWTP upgrade to secondary costs. Option B
present worth costs are higher than Option A, but on-site solids handling is more cost-effective than
continued discharge to Metro.
Table 5-22. Option B-1 – Projected Wastewater Discharge and Recycled Water Production Rates (MGD)
Wastewater 2010 2015 2020 2025 2030
Total Metro Discharge [1] 0.84 - - - -
Total District WW Flow 1.84 1.93 1.97 2.09 2.15
Recycled 2010 2015 2020 2025 2030
RWCWRF Production [2] 1.000 2.340 2.340 2.340 2.340
Recycled Demand [3] 3.64 3.93 4.46 5.18 6.07
SBWRF Purchase 2.64 1.59 2.12 2.84 3.73
SBWRF Annual Contract Amount [4] 2.98 4.11 4.74 5.14 -
[1] Otay WD has a 1.231 MGD Metro capacity.
[2] Producing at 77% of Total RWCWRF Capacity in 2010. Producing at 90% of Total RWCWRF Capacity beginning in 2015.
[3] Based on Recycled Water Memo 06-08-12.
[4] Based on Recycled Purchase Agreement between City of San Diego and Otay WD.
04094007.0000 D - 22 April 2013
Table 5-23. Option B-1 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,462,160
MWD/SDCWA Rebate $(431,200) $(1,009,008) $(1,009,008) $(524,160) $(524,160)
Metro Discharge Cost $2,595,293 $ - $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
On-Site Solids Handling Power Cost [1] $ - $112,336 $112,336 $112,336 $112,336
On-Site Solids Handling Chemical Cost [1] $ - $84,718 $84,718 $84,718 $84,718
Power Cost [2] $90,100 $559,263 $559,263 $559,263 $559,263
Chemical Cost [1] $ - $30,947 $30,947 $30,947 $30,947
Collection/Treatment/Operation [2] $354,682 $1,504,221 $1,504,221 $1,504,221 $1,504,221
RWCWRF Operating Cost [2] $199,211 $844,860 $844,860 $844,860 $844,860
Capital Costs 2010 2015 2020 2025 2030
On-Site Solids Handling Cost [1] $ - $5,483,107 $ - $ - $ -
Expansion/Upgrade Cost [1] $ - $14,966,588 $ - $ - $ -
PLWWTP Upgrade Cost $ - $- $ - $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12. [2] Based on Recycled and Sewer Cost Spreadsheet from the District.
Table 5-24. Option B-1 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $3,136,346 $3,136,346 $3,136,346 $3,136,346
Factor Table
4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$14,783,166 $14,783,166 $14,783,166 $3,136,346
Capital Costs $20,449,695 $ - $ - $ -
Present Worth Amount $35,232,861 $14,783,166 $14,783,166 $3,136,346
Wastewater Total $67,935,538
Present Worth (Recycled) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $602,392 $850,192 $1,491,140 $938,000
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$2,839,375 $4,007,380 $7,028,488 $938,000
Capital Costs
$ - $ - $ - $ -
Present Worth Amount $2,839,375 $4,007,380 $7,028,488 $938,000
Recycled Total $14,813,243 Total $82,748,781
04094007.0000 D - 23 April 2013
Table 5-25. Option B-2 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,462,160
MWD/SDCWA Rebate $(431,200) $(1,009,008) $(1,009,008) $(524,160) $(524,160)
Metro Discharge Cost $2,595,293 $803,305 $803,305 $803,305 $803,305
PLWWTP Upgrade Cost $ - $ - $40,622 $40,622 $40,622
On-Site Solids Handling Power Cost [1] $ - $ - $ - $ - $ -
On-Site Solids Handling Chemical Cost [1] $ - $ - $ - $ - $ -
Power Cost [2] $90,100 $559,263 $559,263 $559,263 $559,263
Chemical Cost [1] $ - $30,947 $30,947 $30,947 $30,947 Collection/Treatment/Operation
[2] $354,682 $1,504,221 $1,504,221 $1,504,221 $1,504,221
RWCWRF Operating Cost [2] $199,211 $844,860 $844,860 $844,860 $844,860
Capital Costs On-Site Solids Handling Cost [1] $ - $ - $ - $ - $ -
Enhancement/Upgrade Cost [1] $ - $14,966,588 $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $5,956,828 $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment
10-29-12. [2] Based on Recycled and Sewer Cost Spreadsheet.
Table 5-26. Option B-2 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per Interest Period
$3,742,597 $3,783,218 $3,783,218 $3,783,218
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $17,640,729 $17,832,200 $17,832,200 $3,783,218
Capital Costs
$14,966,588 $5,956,828 $ - $ -
Present Worth Amount
$32,607,317 $23,789,028 $17,832,200 $3,783,218
Wastewater Total $78,011,763
Present Worth (Recycled) 2010 2015 2020 2025 2030
Interest Rate
2% 2% 2% 2%
Uniform Amount per Interest Period
$602,392 $850,192 $1,491,140 $938,000
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $2,839,375 $4,007,380 $7,028,488 $938,000
Capital Costs $ - $ - $ - $ -
Present Worth Amount
$2,839,375 $4,007,380 $7,028,488 $938,000
Recycled Total $14,813,243 Total $92,825,006
04094007.0000 D - 24 April 2013
Table 5-27. Option B-3 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,462,160
MWD/SDCWA Rebate $(431,200) $(1,009,008) $(1,009,008) $(524,160) $(524,160)
Metro Discharge Cost $2,595,293 $803,305 $803,305 $803,305 $803,305
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
On-Site Solids Handling Power Cost [1] $ - $ - $ - $ - $ -
On-Site Solids Handling Chemical Cost [1] $ - $ - $ - $ - $ -
Power Cost [2] $90,100 $559,263 $559,263 $559,263 $559,263
Chemical Cost [1] $ - $30,947 $30,947 $30,947 $30,947
Collection/Treatment/Operation [2] $354,682 $1,504,221 $1,504,221 $1,504,221 $1,504,221
RWCWRF Operating Cost [2] $199,211 $844,860 $844,860 $844,860 $844,860
Capital Costs On-Site Solids Handling Cost [1] $ - $ - $ - $ - $ -
Enhancement/Upgrade Cost [1] $ - $14,966,588 $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Based on Recycled and Sewer Cost Spreadsheet.
Table 5-28. Option B-3 – Present Worth of Wastewater and Recycled Water Costs
Present Worth
(Wastewater) 2010 2015 2020 2025 2030
Interest Rate
2% 2% 2% 2%
Uniform Amount per Interest Period
$3,742,597 $3,742,597 $3,742,597 $3,742,597
Factor Table
4.7135 4.7135 4.7135 1.0000
O&M Present Worth $17,640,729 $17,640,729 $17,640,729 $3,742,597
Capital Costs $14,966,588 $ - $ - $ -
Present Worth Amount
$32,607,317 $17,640,729 $17,640,729 $3,742,597
Wastewater Total $71,631,372
Present Worth (Recycled) 2010 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $602,392 $850,192 $1,491,140 $938,000
Factor Table
4.7135 4.7135 4.7135 1.0000
O&M Present Worth
$2,839,375 $4,007,380 $7,028,488 $938,000
Capital Costs $ - $ - $ - $ -
Present Worth Amount $2,839,375 $4,007,380 $7,028,488 $938,000
Recycled Total $14,813,243 Total $86,444,615
04094007.0000 D - 25 April 2013
5.4.3 Present Worth Costs for Option C
Option C includes expansion of the RWCWRF to 3.9 MGD. The wastewater discharge and recycled water
use projections indicated in Table 5-29 are different than projections for Options A and B. This table is for
the on-site solids handling sub-option, which negates Metro discharge. The increased RWCWF capacity
reduces the need to purchase as much recycled water from the SBWRP. There are three sub-options for
this alternative. Tables 5-30 and 5-31 provide cost projections and present worth calculations for sub-option
C-1. The present worth is $134.3 M. Sub-options C-2 and C-3 are for the no on-site solids handling facilities,
which result in higher present worth costs. Table 5-32 shows the projected wastewater flows and recycled
water sources and amounts for sub-option C-2. Tables 5-33 and 5-34 indicate cost values for sub-option C-
2 at a total present worth of $146 M. Tables 5-35 and 5-36 indicate similar results for sub-option C-3. The
present worth calculation difference is due to the impact of the Point Loma WWTP upgrade to secondary
costs. Option C present worth costs are higher than Option A and B, but on-site solids handling is more
cost-effective than continued discharge to Metro.
Table 5-29. Option C-1 – Projected Wastewater Discharge and Recycled Water Production Rates
(MGD)- On-site Solids Handling
Wastewater 2010 2015 2020 2025 2030
Total Metro Discharge [1] 0.84 - - - -
Total District WW Flow 1.84 1.93 1.97 2.09 2.15
Recycled 2010 2015 2020 2025 2030
RWCWRF Production [2] 1.000 3.510 3.510 3.510 3.510
Recycled Demand [3] 3.64 3.93 4.46 5.18 6.07
SBWRF Purchase 2.64 0.42 0.95 1.67 2.56
SBWRF Annual Contract Amount [4] 2.98 4.11 4.74 5.14 -
[1] Otay WD has a 1.231 MGD Metro capacity.
[2] Producing 77% of Total RWCWRF Capacity.
[3] Based on Recycled Water Memo 06-08-12.
[4] Based on Recycled Purchase Agreement between City of San Diego and Otay WD.
04094007.0000 D - 26 April 2013
Table 5-30: Option C-1 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,003,520
MWD/SDCWA Rebate ($431,200) ($1,513,512) ($1,513,512) ($786,240) ($786,240)
Metro Discharge Cost $2,595,293 $0 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $0 $0 $0
On-Site Solids Handling Power Cost [1] $0 $168,504 $168,504 $168,504 $168,504
On-Site Solids Handling Chemical Cost [1] $0 $127,077 $127,077 $127,077 $127,077
Power Cost [2] $90,100 $1,197,130 $1,197,130 $1,197,130 $1,197,130
Chemical Cost [1] $0 $77,081 $77,081 $77,081 $77,081
Collection/Treatment/Operation
[2] $354,682 $2,999,394 $2,999,394 $2,999,394 $2,999,394
RWCWRF Operating Cost [2] $199,211 $1,684,638 $1,684,638 $1,684,638 $1,684,638
Capital Costs On-Site Solids Handling Cost [1] $0 $8,324,288 $0 $0 $0
Enhancement/Upgrade Cost [1] $0 $23,199,403 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $0 $0 $0
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12. [2] Based on Recycled and Sewer Cost Spreadsheet.
Table 5-31. Option C-1 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $6,253,824 $6,253,824 $6,253,824 $6,253,824
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $29,477,400 $29,477,400 $29,477,400 $6,253,824
Capital Costs $31,523,691 $0 $0 $0
Present Worth Amount $61,001,091 $29,477,400 $29,477,400 $6,253,824
Wastewater Total $126,209,714
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $97,888 $345,688 $1,229,060 $217,280
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $461,395 $1,629,400 $5,793,174 $217,280
Capital Costs $0 $0 $0 $0
Present Worth Amount $461,395 $1,629,400 $5,793,174 $217,280
Recycled Total $8,101,250 Total $134,310,963
04094007.0000 D - 27 April 2013
Table 5-32. Option C-2 – Projected Wastewater Discharge and Recycled Water Production Rates
(MGD)- No On-site Solids Handling
Wastewater 2010 2015 2020 2025 2030
Total Metro Discharge [1] 0.84 0.39 0.39 0.39 0.39
Total District WW Flow 1.84 1.93 1.97 2.09 2.15
Recycled 2010 2015 2020 2025 2030
RWCWRF Production [2] 1.000 3.510 3.510 3.510 3.510
Recycled Demand [3] 3.64 3.93 4.46 5.18 6.07
SBWRF Purchase 2.64 0.42 0.95 1.67 2.56
SBWRF Annual Contract Amount [4] 2.98 4.11 4.74 5.14 -
[1] Otay WD has a 1.231 MGD Metro capacity.
[2] Producing 77% of Total RWCWRF Capacity.
[3] Based on Recycled Water Memo 06-08-12.
[4] Based on Recycled Purchase Agreement between City of San Diego and Otay WD.
04094007.0000 D - 28 April 2013
Table 5-33. Option C-2 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,003,520
MWD/SDCWA Rebate ($431,200) ($1,513,512) ($1,513,512) ($786,240) ($786,240)
Metro Discharge Cost $2,595,293 $1,204,957 $1,204,957 $1,204,957 $1,204,957
PLWWTP Upgrade Cost $0 $0 $60,933 $60,933 $60,933
On-Site Solids Handling Power Cost
[1] $0 $0 $0 $0 $0
On-Site Solids Handling Chemical Cost [1] $0 $0 $0 $0 $0
Power Cost [2] $90,100 $1,197,130 $1,197,130 $1,197,130 $1,197,130
Chemical Cost [1] $0 $77,081 $77,081 $77,081 $77,081
Collection/Treatment/Operation [2] $354,682 $2,999,394 $2,999,394 $2,999,394 $2,999,394
RWCWRF Operating Cost [2] $199,211 $1,684,638 $1,684,638 $1,684,638 $1,684,638
Capital Costs On-Site Solids Handling Cost [1] $0 $0 $0 $0
Enhancement/Upgrade Cost [1] $0 $23,199,403 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $5,956,828 $0 $0
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-
12. [2] Based on Recycled and Sewer Cost Spreadsheet.
Table 5-34. Option C-2 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $7,163,200 $7,224,133 $7,224,133 $7,224,133
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $33,763,745 $34,050,951 $34,050,951 $7,224,133
Capital Costs $23,199,403 $5,956,828 $0 $0
Present Worth Amount $56,963,148 $40,007,778 $34,050,951 $7,224,133
Wastewater Total $138,246,010
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $97,888 $345,688 $1,229,060 $217,280
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $461,395 $1,629,400 $5,793,174 $217,280
Capital Costs $0 $0 $0 $0
Present Worth Amount $461,395 $1,629,400 $5,793,174 $217,280
Recycled Total $8,101,250 Total $146,347,260
04094007.0000 D - 29 April 2013
Table 5-35. Option C-3 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,168,300 $1,611,400 $1,859,200 $2,015,300 $1,003,520
MWD/SDCWA Rebate ($431,200) ($1,513,512) ($1,513,512) ($786,240) ($786,240)
Metro Discharge Cost $2,595,293 $1,204,957 $1,204,957 $1,204,957 $1,204,957
PLWWTP Upgrade Cost $0 $0 $60,933 $60,933 $60,933
On-Site Solids Handling Power Cost
[1] $0 $0 $0 $0 $0
On-Site Solids Handling Chemical Cost [1] $0 $0 $0 $0 $0
Power Cost [2] $90,100 $1,197,130 $1,197,130 $1,197,130 $1,197,130
Chemical Cost [1] $0 $77,081 $77,081 $77,081 $77,081
Collection/Treatment/Operation [2] $354,682 $2,999,394 $2,999,394 $2,999,394 $2,999,394
RWCWRF Operating Cost [2] $199,211 $1,684,638 $1,684,638 $1,684,638 $1,684,638
Capital Costs On-Site Solids Handling Cost [1] $0 $0 $0 $0 $0
Enhancement/Upgrade Cost [1] $0 $23,199,403 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $5,956,828 $0 $0
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12. [2] Based on Recycled and Sewer Cost Spreadsheet.
Table 5-36. Option C-3 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $7,163,200 $7,163,200 $7,163,200 $7,163,200
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $33,763,745 $33,763,745 $33,763,745 $7,163,200
Capital Costs $23,199,403 $0 $0 $0
Present Worth Amount $56,963,148 $33,763,745 $33,763,745 $7,163,200
Wastewater Total $131,653,837
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $97,888 $345,688 $1,229,060 $217,280
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $461,395 $1,629,400 $5,793,174 $217,280
Capital Costs $0 $0 $0 $0
Present Worth Amount $461,395 $1,629,400 $5,793,174 $217,280
Recycled Total $8,101,250 Total $139,755,087
04094007.0000 D - 30 April 2013
5.4.4 Present Worth Costs for Option D
Option D includes demolition and abandonment of the RWCWRF in favor of complete reliance on Metro for
wastewater disposal and treatment. Present worth costs for the four sub-options in Option D are higher than
costs for all other options. The sub-options are differentiated by recycled water supplies (SBWRP or Chula
Vista) and District payment of Point Loma upgrade costs or not. The presumed wastewater discharge and
indicated recycled water use projections in Table 5-37 are different than projections for Options A, B, and C.
This table indicates recycled water purchase from Chula Vista and presumes discharge of all wastewater to
Metro. Tables 5-38 and 5-39 provide cost projections and present worth calculations for sub-option D-1. The
present worth is $166.1 M. Sub-option D-2 costs are shown in Tables 5-40 and 5-41. The present worth
calculation for sub-option D-2 is about $157 M. An alternative projected wastewater flow and recycled water
source projection is indicated in Table 5-42 for continued recycled water purchase from SBWRP. Tables 5-
43 and 5-44 indicate cost values for sub-option D-3 at a total present worth of $163 M. Tables 5-45 and 5-
46 indicate a $10M difference in present worth costs due to the impact of assuming Point Loma upgrade
costs. The sub-option D-4 present worth is $153.7 M.
Table 5-37. Option D-1 and D-2 – Projected Wastewater Discharge and Recycled Water Production Rates
(MGD) – Includes Chula Vista Recycled Water Purchase
Recycled 2010 2015 2020 2025 2030
Chula Vista Available [1] - - 2.00 4.00 6.00
Chula Vista Purchase - - 2.00 4.00 6.00
SBWRF Purchase 3.64 3.93 2.46 1.18 0.07
[1] Based on City of Chula Vista's Acquisition of Additional Wastewater Capacity Project Final Report April
2012
04094007.0000 D - 31 April 2013
Table 5-38. Option D-1 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase Chula Vista) $0 $0 $784,000 $1,568,000 $2,352,000
RW Cost (purchase SBWRF) $1,426,880 $1,540,560 $964,320 $462,560 $27,440
Metro Discharge Cost $5,684,927 $5,962,994 $6,086,579 $6,457,335 $6,642,713
PLWWTP Upgrade Cost $0 $0 $0 $0 $0
On-Site Solids Handling Power Cost [1] $0 $0 $0 $0 $0
On-Site Solids Handling Chemical Cost [1] $0 $0 $0 $0 $0
Power Cost [2] $0 $0 $0 $0 $0
Chemical Cost [1] $0 $0 $0 $0 $0
Collection/Treatment/Operation [2] $0 $0 $0 $0 $0
RWCWRF Operating Cost [2] $0 $0 $0 $0 $0
Capital Costs 2010 2015 2020 2025 2030
Decommission/Demolition cost [1] $0 $3,955,800 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $0 $0 $0
Additional Metro Cost [2] $0 $0 $0 $0 $27,570,000
Chula Vista Pump Station/Pipeline [3] $0 $0 $3,960,000 $0 $0
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Per discussion with Rita Bell. $22 Million paid to Metro, $8 Million paid to the County.
[3] 6 MGD Pump Station (600 hp), 8000 LF of Pipeline.
Table 5-39. Option D-1 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per Interest
Period $5,962,994 $6,394,367 $6,783,872 $6,978,624
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $28,106,570 $30,139,850 $31,975,780 $6,978,624
Capital Costs $3,955,800 $5,956,828 $0 $27,570,000
Present Worth Amount $32,062,370 $36,096,678 $31,975,780 $34,548,624
Wastewater Total $134,683,453
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per Interest
Period $1,540,560 $1,748,320 $2,030,560 $2,379,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $7,261,430 $8,240,706 $9,571,045 $2,379,440
Capital Costs $0 $3,960,000 $0 $0
Present Worth Amount $7,261,430 $12,200,706 $9,571,045 $2,379,440
Recycled Total $31,412,620 Total $166,096,074
04094007.0000 D - 32 April 2013
Table 5-40. Option D-2 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase Chula Vista) $0 $0 $784,000 $1,568,000 $2,352,000
RW Cost (purchase SBWRF) $1,426,880 $1,540,560 $964,320 $462,560 $27,440
Metro Discharge Cost $5,684,927 $5,962,994 $6,086,579 $6,457,335 $6,642,713
PLWWTP Upgrade Cost $0 $0 $0 $0 $0 On-Site Solids Handling Power
Cost [1] $0 $0 $0 $0 $0 On-Site Solids Handling
Chemical Cost [1] $0 $0 $0 $0 $0
Power Cost [2] $0 $0 $0 $0 $0
Chemical Cost [1] $0 $0 $0 $0 $0
Collection/Treatment/Operation [2] $0 $0 $0 $0 $0
RWCWRF Operating Cost [2] $0 $0 $0 $0 $0
Capital Costs 2010 2015 2020 2025 2030
Decommission/Demolition cost [1] $0 $3,955,800 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $0 $0 $0
Additional Metro Cost [2] $0 $0 $0 $0 $27,570,000
Chula Vista Pump Station/Pipeline [3] $0 $0 $3,960,000 $0 $0
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] $22 Million paid to Metro, $8 Million paid to the County per MGD of capacity.
[3] 6 MGD Pump Station (600 hp), 8000 LF of Pipeline.
Table 5-41. Option D-2 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $5,962,994 $6,086,579 $6,457,335 $6,642,713
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $28,106,570 $28,689,090 $30,436,649 $6,642,713
Capital Costs $3,955,800 $0 $0 $27,570,000
Present Worth Amount $32,062,370 $28,689,090 $30,436,649 $34,212,713
Wastewater Total $125,400,822
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $1,540,560 $1,748,320 $2,030,560 $2,379,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $7,261,430 $8,240,706 $9,571,045 $2,379,440
Capital Costs $0 $3,960,000 $0 $0
Present Worth Amount $7,261,430 $12,200,706 $9,571,045 $2,379,440
Recycled Total $31,412,620
Total $156,813,443
04094007.0000 D - 33 April 2013
Table 5-42. Option D-3 and D-4 – Projected Wastewater Discharge and Recycled Water Production Rates (MGD)
Wastewater 2010 2015 2020 2025 2030
Total Metro Discharge [1] 1.84 1.93 1.97 2.09 2.15
Total District WW Flow 1.84 1.93 1.97 2.09 2.15
Recycled 2010 2015 2020 2025 2030
Recycled Demand [2] 3.64 3.93 4.46 5.18 6.07
SBWRF Purchase 3.64 3.93 4.46 5.18 6.07
SBWRF Annual Contract Amount [3] 2.98 4.11 4.74 5.14 -
[1] Otay WD has a 1.231 MGD Metro capacity.
[2] Based on Recycled Water Memo 06-08-12.
[3] Based on Recycled Purchase Agreement between City of San Diego and Otay WD.
04094007.0000 D - 34 April 2013
Table 5-43. Option D-3 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,426,880 $1,611,400 $1,859,200 $2,030,560 $2,379,440
Metro Discharge Cost $5,684,927 $5,962,994 $6,086,579 $6,457,335 $6,642,713
PLWWTP Upgrade Cost $0 $0 $307,788 $326,537 $335,911 On-Site Solids Handling Power
Cost [1] $0 $0 $0 $0 $0 On-Site Solids Handling
Chemical Cost [1] $0 $0 $0 $0 $0
Power Cost [2] $0 $0 $0 $0 $0
Chemical Cost [1] $0 $0 $0 $0 $0
Collection/Treatment/Operation [2] $0 $0 $0 $0 $0
RWCWRF Operating Cost [2] $0 $0 $0 $0 $0
Capital Costs 2010 2015 2020 2025 2030
Decommission/Demolition cost [1] $0 $3,955,800 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $5,956,828 $0 $0
Additional Metro Cost [2] $0 $0 $0 $0 $27,570,000
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Per discussion with District staff, $22 Million per MGD capacity paid to Metro.
Table 5-44. Option D-3 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per Interest
Period $5,962,994 $6,394,367 $6,783,872 $6,978,624
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $28,106,570 $30,139,850 $31,975,780 $6,978,624
Capital Costs $3,955,800 $5,956,828 $0 $27,570,000
Present Worth Amount $32,062,370 $36,096,678 $31,975,780 $34,548,624
Wastewater Total $134,683,453
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest
Period $1,611,400 $1,859,200 $2,030,560 $2,379,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $7,595,334 $8,763,339 $9,571,045 $2,379,440
Capital Costs $0 $0 $0 $0
Present Worth Amount $7,595,334 $8,763,339 $9,571,045 $2,379,440
Recycled Total $28,309,158 Total $162,992,611
04094007.0000 D - 35 April 2013
Table 5-45. Option D-4 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase SBWRF) $1,426,880 $1,611,400 $1,859,200 $2,030,560 $2,379,440
Metro Discharge Cost $5,684,927 $5,962,994 $6,086,579 $6,457,335 $6,642,713
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
On-Site Solids Handling Power Cost [1] $ - $ - $ - $ - $ -
On-Site Solids Handling Chemical Cost [1] $ - $ - $ - $ - $ -
Power Cost [2] $ - $ - $ - $ - $ -
Chemical Cost [1] $ - $ - $ - $ - $ -
Collection/Treatment/Operation [2] $ - $ - $ - $ - $ -
RWCWRF Operating Cost [2] $ - $ - $ - $ - $ -
Capital Costs 2010 2015 2020 2025 2030
Decommission/Demolition cost [1] $ - $3,955,800 $ - $ - $ -
PLWWTP Upgrade Cost $ - $ - $ - $ - $ -
Additional Metro Cost [2] $ - $ - $ - $ - $27,570,000
[1] Based on Final RWCWRF Capital Cost Assessment 10-29-12.
[2] Per discussion with Rita Bell. $22 Million paid to Metro, $8 Million paid to the County.
Table 5-46. Option D-4 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $5,962,994 $6,086,579 $6,457,335 $6,642,713
Factor Table 4.7135 $5 4.7135 1.0000
O&M Present Worth $28,106,570 $28,689,090 $30,436,649 $6,642,713
Capital Costs $3,955,800 $0 $0 $27,570,000
Present Worth Amount $32,062,370 $28,689,090 $30,436,649 $34,212,713
Wastewater Total $125,400,822
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2% Uniform Amount per
Interest Period $1,611,400 $1,859,200 $2,030,560 $2,379,440
Factor Table 4.7135 4.7135 4.7135 $1
O&M Present Worth $7,595,334 $8,763,339 $9,571,045 $2,379,440
Capital Costs $0 $0 $0 $0
Present Worth Amount $7,595,334 $8,763,339 $9,571,045 $2,379,440
Recycled Total $28,309,158 Total $153,709,980
04094007.0000 D - 36 April 2013
5.4.5 Present Worth Costs for Option E
Option E includes demolition and abandonment of RWCWRF and partnership with San Diego County in a
new conceptualized wastewater treatment and water reclamation plant. There are two sub-options
associated with Option E which are for Point Loma upgrade to secondary or not. The new plant is assumed
to be a similar treatment process as Chula Vista (MBR) at similar cost per MGD capacity. The plant is
presumed to have on-site solids handling in that the concept proposes an NPDES permit to the Sweetwater
River. The District’s share of the new plant capacity and cost is about 22 percent based on flow projections
shown in Table 5-47. Tables 5-48 and 5-49 provide cost projections and present worth calculations for sub-
option E-1. The present worth is $154 M. Tables 5-50 and 5-51 indicate cost values for sub-option E-2 at a
total present worth of $148 M. The concept and projected costs for Option E carry the most risk, in that
details on the proposed new plant are not developed. The present worth calculation difference is due to the
impact of the Point Loma WWTP upgrade to secondary costs. Option E present worth costs are higher than
Options A, B, and C, but less than complete reliance on Metro.
Table 5-47. Option E-1 and E-2 – Projected Wastewater Discharge and Recycled Water Production Rates (MGD)
Wastewater 2010 2015 2020 2025 2030
Total Metro Discharge [1] 1.84 1.93 - - -
Total District WW Flow 1.84 1.93 1.97 2.09 2.15
Recycled 2010 2015 2020 2025 2030
Joint Project Production - - 6.00 8.00 10.00
Joint Project Purchase - - 1.97 2.09 2.15
Recycled Demand [2] 3.64 3.93 4.46 5.18 6.07
SBWRF Purchase 3.64 3.93 2.49 3.09 3.92
SBWRF Annual Contract Amount [3] 2.98 4.11 4.74 5.14 -
[1] Otay WD has a 1.231 MGD Metro capacity. [2] Based on Recycled Water Memo 06-08-12. [3] Based on Recycled Purchase Agreement between City of San Diego and Otay WD.
04094007.0000 D - 37 April 2013
Table 5-48. Option E-1 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase Joint Project) $0 $0 $772,240 $819,280 $842,800
RW Cost (purchase SBWRF) $1,426,880 $1,611,400 $1,859,200 $2,015,300 $1,536,640
Metro Discharge Cost $5,684,927 $5,962,994 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $0 $0 $0
Joint Project Cost (22%) [1] $0 $0 $906,583 $1,530,083 $2,150,000
Capital Costs $2,010 $2,015 $2,020 $2,025 $2,030
Total Joint Project Cost [1] $0 $0 $119,066,667 $34,933,333 $37,466,667
Otay Joint Project Cost (22%) [1] $0 $0 $25,599,333 $7,510,667 $8,055,333
Decommission/Demolition cost [1] $0 $3,955,800 $0 $0 $0
Additional Metro Cost [2] $0 $20,970,000 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $5,956,828 $0 $0
Joint Project Pump Station/Pipeline [3] $0 $0 $4,440,000 $0 $0
[1] Based on City of Chula Vista's Acquisition of Additional Wastewater Capacity Project Final Report April 2012
[2] Per discussion with District staff, $22 Million paid to Metro and $8 Million paid to the County per MGD of capacity.
[3] 10 MGD Pump Station (900 hp), 7000 LF of Pipeline.
Table 5-49. Option E-1 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $5,962,994 $906,583 $1,530,083 $2,150,000
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $28,106,570 $4,273,181 $7,212,048 $2,150,000
Capital Costs $24,925,800 $31,556,161 $7,510,667 $8,055,333
Present Worth Amount $53,032,370 $35,829,342 $14,722,715 $10,205,333
Wastewater Total $113,789,760
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $1,611,400 $2,631,440 $2,834,580 $2,379,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $7,595,334 $12,403,292 $13,360,793 $2,379,440
Capital Costs $0 $4,440,000 $0 $0
Present Worth Amount $7,595,334 $16,843,292 $13,360,793 $2,379,440
Recycled Total $40,178,859 Total $153,968,619
04094007.0000 D - 38 April 2013
Table 5-50. Option E-2 – Annual O&M and Capital Costs
O&M Costs 2010 2015 2020 2025 2030
RW Cost (purchase Joint Project) $0 $0 $772,240 $819,280 $842,800
RW Cost (purchase SBWRF) $1,426,880 $1,611,400 $1,859,200 $2,015,300 $1,536,640
Metro Discharge Cost $5,684,927 $5,962,994 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $0 $0 $0
Joint Project Cost (22%) [1] $0 $0 $906,583 $1,530,083 $2,150,000
Capital Costs $2,010 $2,015 $2,020 $2,025 $2,030
Total Joint Project Cost [1] $0 $0 $119,066,667 $34,933,333 $37,466,667
Otay Joint Project Cost (22%) [1] $0 $0 $25,599,333 $7,510,667 $8,055,333
Decommission/Demolition cost [1] $0 $3,955,800 $0 $0 $0
Additional Metro Cost [2] $0 $20,970,000 $0 $0 $0
PLWWTP Upgrade Cost $0 $0 $0 $0 $0
Joint Project Pump Station/Pipeline [3] $0 $0 $4,440,000 $0 $0
[1] Based on City of Chula Vista's Acquisition of Additional Wastewater Capacity Project Final Report April 2012
[2] Per discussion with District staff, $22 Million paid to Metro and $8 Million paid to the County per MGD of capacity.
[3] 10 MGD Pump Station (900 hp), 7000 LF of Pipeline.
Table 5-51. Option E-2 – Present Worth of Wastewater and Recycled Water Costs
Present Worth (Wastewater) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $5,962,994 $906,583 $1,530,083 $2,150,000
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $28,106,570 $4,273,181 $7,212,048 $2,150,000
Capital Costs $24,925,800 $25,599,333 $7,510,667 $8,055,333
Present Worth Amount $53,032,370 $29,872,514 $14,722,715 $10,205,333
Wastewater Total $107,832,933
Present Worth (Recycled) 2015 2020 2025 2030
Interest Rate 2% 2% 2% 2%
Uniform Amount per Interest Period $1,611,400 $2,631,440 $2,834,580 $2,379,440
Factor Table 4.7135 4.7135 4.7135 1.0000
O&M Present Worth $7,595,334 $12,403,292 $13,360,793 $2,379,440
Capital Costs $0 $4,440,000 $0 $0
Present Worth Amount $7,595,334 $16,843,292 $13,360,793 $2,379,440
Recycled Total $40,178,859 Total $148,011,792
04094007.0000 D - 39 April 2013
5.4.6 Summary of Present Worth Costs
A summary of present worth costs for the 18 wastewater management sub-options associated with the five
primary options is shown in Table 5-52 below. The summary costs are presented in $ million. The table is
broken out into options that indicate District purchase of recycled water from SBWRP and those assuming
District purchase of recycled water from Chula Vista when water becomes available. For Option A, present
worth is significantly less for on-site solids handling at RWCWRF due to presumed avoidance of significant
discharge to Metro and future Point Loma upgrade costs or its Metro alternative. For Options A-C
associated with capacity at RWCWRF, the lowest present worth costs are for retaining the RWCWRF at 1.3
MGD capacity and not expanding to 2.6 nor 3.9 MGD. The Options D and E associated with the
abandonment of RWCWRF are significantly more costly than RWCWRF retention due to costs associated
with increased discharge to Metro, with risks of incurring costs for Point Loma upgrade (D), and cost of a
new joint WWTP in partnership with the County.
Table 5-52. Present Worth Cost Summary for Wastewater Management Options ($M)
Option
SBWRP Only
No Chula Vista Purchases
Chula Vista WRF Only
No SBWRP Purchases
No Point Loma
WWTP Upgrade
Point Loma
WWTP Upgrade
No Point Loma
WWTP Upgrade
Point Loma
WWTP Upgrade
A Onsite sludge $37.1 -- $34.7 --
No onsite sludge $79.3 $87.0 $77.0 $84.6
B Onsite sludge $82.7 -- -- --
No onsite sludge $86.4 $92.8 -- --
C Onsite sludge $134.3 -- -- --
No onsite sludge $139.8 $146.3 -- --
D $153.7 $163.0 $156.8 $166.1
E (onsite sludge) $148.0 $154.0
Appendix E
Cost Evaluations Excel Workbook
THIS PAGE INTENTIONALLY LEFT BLANK