HomeMy WebLinkAbout; Master Plan of Sewerage 1987; Master Plan of Sewerage; 1987-12-30CITY OF
CARLSBAD
MASTER PLAN
OF
SEWERAGE
December, 1987
Wilson Engineering
Consulting Engineers
CITY OF CARLSBAD
City Council Members
Claude A. Lewis-Mayor
Ann J. Kulchin - Mayor Pro-Tenn
John J. Mannaux
Mark V. Pettine
Eric Larson
WILSON ENGINEERING
DEXTER S. WILSON. P.E.
KEVIN E. SCHMIDT. P.E.
ANDREW M. OVEN. RE.
December, 1987 101-007
City of Carlsbad
2075 Las Palmas Drive
Carlsbad, CA 92009
Attention: City of Carlsbad Council
Subject: Master Plan of Sewerage
In accordance with our agreement approved by Council on
February 17, 1987, we are submitting a report on the
sewerage system improvements and the fiscal impact of these
improvements on the City of Carlsbad. The report presents a
phased program for the construction of major sewage
facilities to serve the study area beyond the year 2000.
The total estimated costs for the future recommended
facilities for the City of Carlsbad is $56,824,000. Of this
total, $49,126,000 is to be funded through capacity fees and
will be constructed by the City of Carlsbad. In order to
finance these facilities, this report recommends increasing
the capacity fee to $1,247 per unit. The remaining
$7,698,000 will be funded through development.
This report is prepared in accordance with and as required
by the Growth Management Program. It is designed to
effectively assist in the administration of the Growth
Management Program, and should be updated annually.
We appreciate the opportunity to provide you with the
engineering services involved in the preparation of this
report. We would be pleased to discuss our findings and
recommendations with you.
Wilson^ Engineering
Dexter S. Wilson
DSW:jaa
2185 FARADAY AVENUE, SUITE 140 CARLSBAD. CALIFORNIA 92008 (619) 438-4422
TABLE OF CONTENTS
VOLUME 1 PAGE NO.
LIST OF TABLES v
LIST OF FIGURES vii
CHAPTER 1. INTRODUCTION
Master Plan Modification . 2
History 2
Summary 3
Chapter 2 - Description of Study Area .... 3
Chapter 3 - Land Use and Population Planning
in Study Area 3
Chapter 4 - Existing Sewerage System 3
Chapter 5 - Wastewater Flow Projection
Criteria 3
Chapter 6 - Design Criteria and Unit
Construction Costs 4
Chapter 7 - Improvement Program 4
Chapter 8 - Revenue Program Requirements ... 4
Chapter 9 - Reclamation Program 4
Conclusions 5
Acknowledgments 6
CHAPTER 2. DESCRIPTION OF STUDY AREA
Study Area 7
Topography 7
CHAPTER 3. LAND USE AND POPULATION PLANNING IN
STUDY AREA
Land Use 12
Current Land Use 12
Projected Land Use 12
Population Projections 12
Present Population 15
Future Population 15
CHAPTER 4. EXISTING SEWERAGE SYSTEM
Description of Existing Conveyance System 17
Vista/Carlsbad Interceptor 19
Buena Vista Lift Station (Unit C) 19
Agua Hedionda Lift Station (Unit G) . . . . 19
North Agua Hedionda Interceptor 23
Foxes Landing Lift Station 23
Trunk Sewers 23
Buena/San Marcos Interceptor System 27
Buena Interceptor 27
San Marcos Interceptor 27
North Batiquitos Interceptor 31
North Batiquitos Lift Station 31
Trunk Sewers 31
TABLE OF CONTENTS (Continued)
Other Existing Lift Stations
Wastewater Treatment Facilities
Encina Water Pollution Control Facility
(Unit I)
Treatment Plant Ownership and Capacity
(Unit I)
Encina Ocean Outfall System (Unit J) . .'
Lake Calavera Hills Water Reclamation Plant
CHAPTER 5. WASTEWATER FLOW PROJECTION CRITERIA
Flow Factors
Average Daily Flow [
Peak Flows [ [
Flow Projections
CHAPTER 6. DESIGN CRITERIA AND UNIT CONSTRUCTION
COSTS
Design Criteria
Gravity Sewers
Force Mains and Sewage Lift Stations ....
Unit Costs
Gravity Sewers and Force Mains
Sewage Lift Stations
CHAPTER 7. IMPROVEMENT PROGRAM
Conveyance System Improvements
Wastewater Treatment System Improvements . . ! !
Encina Capital Improvement Program
Phase IV Project
Solids Management Program
Ocean Outfall Improvements
Lake Calavera Hills Water Reclamation Plant
Improvements to the Lake Calavera Hills
Water Reclamation Plant
CHAPTER 8. REVENUE PROGRAM REQUIREMENTS
Use of Funds
Sewer Service Charges [ [
Capacity Fees [
Capacity Fee !!!!!**
CHAPTER 9. RECLAMATION PROGRAM
Water Reclamation Issues
Cost .*.*.'!.'.*
Cost of Reclaimed Water
Capital Costs [
Regulations !!!!!*
Regional Water Quality Control Board ....
State Health Department
Existing Reclaimed Water Facilities ....****
31
35
35
35
36
37
39
39
39
40
45
45
45
46
46
47
49
61
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62
62
63
63
63
65
65
65
66
67
67
67
68
68
68
69
69
11
TABLE OF CONTENTS (Continued).
Conveyance System 69
Water Reclamation Plants 70
The Lake Calavera Hills Water Reclamation
Plant 70
Meadowlark Water Reclamation Plant .... 70
Shadow Ridge Water Reclamation Plant ... 70
Gafner Water Reclamation Plant 70
Facilities 70
Summary 73
LIST OF REFERENCES 75
VOLUME 2
Appendices
A. Equivalent Dwelling Units and Wastewater
Flow Projections by Zone A-l
B. Summary of Computer Flow Projections . . . B-1
C. Growth Management Monitoring Program . . . C-l
D. Lake Calavera Hills Water Reclamation
Plant Report D-1
E. Justification of Flow Generation Factors . E-1
F. Lift Station Data Sheets F-1
G. Interagency Agreements G-1
111
iv
LIST OF TABLES
PAGE NO,
Table 1-1 Summary of Recommended Improvements . . 5
Table 3-1 Population Estimates for Study Area . . 11
Table 4-1 Engineering Data for the
Vista/Carlsbad Interceptor 20
Table 4-2 Engineering Data for the North Agua
Hedionda Interceptor 24
Table 4-3 Engineering Data for the Buena
Interceptor 28
Table 4-4 Engineering Data for the San Marcos
Interceptor 28
Table 4-5 Engineering Data for the North
Batiquitos Interceptor 32
Table 4-6 Current Encina Water Pollution Control
Facility Ownership and Capacity .... 36
Table 4-7 Current Encina Ocean Outfall Ownership
and Capacity Rights 37
Table 4-8 Lake Calavera Hills Water Reclamation
Plant Capacity of Major Process Units . 37
Table 5-1 Unit Flow Generation Factors 40
Table 5-2 Existing and Future Wastewater Flow
Estimates 40
Table 5-3 Wastewater Flow Projection 43
Table 6-1 Unit Construction Costs 46
Table 7-1 Improvements to Vista/Carlsbad
Interceptor Sewage Drainage Basin ... 49
Table 7-2 Improvements to North Agua Hedionda
Interceptor Sewage Drainage Basin ... 53
Table 7-3 Improvements to South Agua Hedionda
Interceptor Sewage Drainage Basin ... 54
Table 7-4 Improvements to Buena/San Marcos
Interceptor Sewage Drainage Basin ... 57
Table 7-5 Improvements to North Batiquitos
Interceptor Sewage Drainage Basin ... 58
Table 7-6 Improvements to the Encina Water
Pollution Control Facility 62
Table 7-7 Improvements to the Lake Calavera
Hills Water Reclamation Plant 64
Table 8-1 Connection Fees 66
vi
LIST OF FIGURES
PAGE NO.
Figure 2-1
Figure 3-1
Figure 4-1
Figure 4-2
Figure 4-3
Figure 4-4
Figure 5-1
Figure 7-1
Figure 7-2
Figure 7-3
Figure 7-4
Figure 7-5
Figure 9-1
Exhibit A
Study Area and Sewer Drainage
Basins 9
Sewer Drainage Zones 13
Vista/Carlsbad Interceptor System . . 21
North Agua Hedionda Interceptor
System 25
Buena/San Marcos Interceptor System . 29
North Batiquitos Interceptor System . 33
Peaking Factor Chart 41
Improvements to Vista/Carlsbad
Interceptor System ... 51
Improvements to North Agua Hedionda
Interceptor System 52
Improvements to South Agua Hedionda
Interceptor System 55
Improvements to Buena/San Marcos
Interceptor System 56
Improvements to North Batiquitos
Interceptor System 59
Reclaimed Water Lines and Potential
Use Areas 71
Recommended Improvement Program
Vll
viii
CHAPTER 1
INTRODUCTION
On July 1, 1986, the City Council of Carlsbad adopted a
Growth Management Plan designed to insure provision of
adequate facilities to accommodate future development.
Implementation of the Growth Management Program was
envisioned as a three level system involving a Citywide
Facilities and Improvement Plan, the preparation of 25 Zone
Facilities Plans and individual project approvals. The
Citywide Plan established performance standards for eleven
critical services. Subsequent zone plans are to show how
each area of the City of Carlsbad proposes to meet those
standards.
The Sewer Collection System and Wastewater Treatment
Capacity were two key elements in the Growth Management
Plan. The Citywide Facilities and Improvement Plan
established the following standards for sewer collection and
wastewater treatment:
SEWER COLLECTION SYSTEM PERFORMANCE STANDARD - Trunk
line capacity to meet demand as determined by the
appropriate sewer district must be provided concurrent
with development.
WASTEWATER TREATMENT CAPACITY PERFORMANCE STANDARD -
Sewer plant capacity is adequate for at least a five
year period.
As a further implementation of the Growth Management
Program, the voters of the City of Carlsbad in November of
1986 passed Proposition E approving the Growth Management
Program and establishing a cap on total buildout dwelling
units of 54,599. These units were assigned to quadrants of
the City of Carlsbad.
This current revision of the Sewer Master Plan is required
to reflect the changes necessitated by the Growth Management
Program and is designed to effectively assist in the
administration of that program. To accomplish this task the
sewer basins identified in previous master plans have been
redefined consistent with zone boundaries. Interceptor and
trunk systems are evaluated in terms of conformance with
standards over time related to each growth management zone.
Appendix B contains an analysis of each interceptor sewer
keyed to development in each growth management zone. By
maintaining records of development and flow data within each
sewer subbasin, the City of Carlsbad staff will be able to
insure adequate capacity to meet the sewer collection
standards concurrent with development activities.
Master Plan Modification
Two significant changes in sewer system design are
incorporated into the current master plan:
1. The Lake Calavera Hills Water Reclamation Plant
Service Area has been redesigned such that the
sewer system can function with or without the
operation of the reclamation plant. Policies
related to plant operation are detailed in Chapter
5 and Appendix D.
2. The Palomar Oaks Business Park Area located north
of Palomar Airport Road and east of El Camino Real
has been diverted from the South Agua Hedionda
Drainage Basin into the Buena Outfall serving the
Encina Canyon Drainage Basin.
With minor exceptions, the current master plan follows and
builds upon previous master plan data and systems.
HISTORY
The first sewer service in the City of Carlsbad area was
provided by the Carlsbad Sanitary District. The Carlsbad
Sanitary District was formed in 1929. During the same year,
a sewage treatment plant and a system of sewer lines
covering the northwest corner of the present downtown area
of the City of Carlsbad were constructed. Thus, portions of
the City of Carlsbad's existing conveyance system date back
as far as 1929. The original treatment plant location was
on the south shore of the Buena Vista Lagoon adjacent to
Carlsbad Boulevard. This is the present location of the
Home Plant Lift Station which pumps flow from the old
treatment plant site into the Vista/Carlsbad Interceptor.
The Carlsbad Sanitary District provided sewer service until
the City of Carlsbad incorporated in 1952. When the City of
Carlsbad incorporated, there were approximately 600 parcels
of property being served by the Carlsbad Sanitary District.
The City of Carlsbad expanded the sewer system and the
number of connections continued to grow. In 1960, the old
treatment plant site adjacent to Carlsbad Boulevard was
heavily taxed and new facilities were needed. This led to
the planning and construction of the Encina Water Pollution
Control Facility by the City of Carlsbad and the Vista
Sanitation District. The Encina Water Pollution Control
Facility was put into operation in 1965 and all flows to the
old Carlsbad Sanitary District plant were diverted to the
new facility which has been utilized by the City of Carlsbad
to treat all of their flows since that time.
SUMMARY
Chapter 2 - Description of Study Area
The study area consists of about 70 percent of the City of
Carlsbad and contains 19,221 acres. There are five major
sewage drainage basins within the study area and these are
shown on Figure 2-1.
Chapter 3 - Land Use and Population Planning in Study Area
The present population of the study area is 39,000. The
ultimate population of the study area is projected to be
95,700, but will not be reached until well after the year
2000. The majority of the development in the City of
Carlsbad is currently in the coastal strip and is
predominantly residential development. Development will
proceed inland and the percentage of commercial and
industrial development will increase.
Chapter 4 - Existing Sewerage System
The City of Carlsbad wastewater collection system utilizes
about 100 miles of sanitary sewers, 15 sewage lift stations
and 2 -treatment plants. There are currently four major
wastewater interceptor systems within the City of Carlsbad.
These interceptors are the Vista/Carlsbad Interceptor, the
North Agua Hedionda Interceptor, the Buena/San Marcos
Interceptor System and the North Batiquitos Interceptor.
The City of Carlsbad is a part owner of the Encina Water
Pollution Control Facility, which is located within the
study area. The City of Carlsbad also owns the Lake
Calavera Hills Water Reclamation Plant. The Lake Calavera
Hills Water Reclamation Plant is currently not being
operated and major improvements would be needed to make it
operational.
Chapter 5 - Wastewater Flow Projection Criteria
Average wastewater flows from the City of Carlsbad were
projected using 220 gallons per day per equivalent dwelling
unit. All industrial and commercial development was
projected based on estimated equivalent dwelling units and
converted to projected flows utilizing the same 220 gallons
per day per equivalent dwelling unit figure. The average
flow was converted to peak flow utilizing the sliding scale
contained in Figure 5-1. The ultimate average flow from
the City of Carlsbad was estimated to be 13.41 million
gallons per day.
Chapter 6 - Design Criteria and Unit Construction Costs
The City of Carlsbad design criteria and standards of the
industry were utilized to design facilities in this report.
Cost estimates were based on present unit costs for
pipelines and force mains and lump sums for sewage lift
stations.
Chapter 7 - Improvement Program
Table 1-1 provides a summary of the recommended improvement
program for the City of Carlsbad wastewater system. This
program provides for a total expenditure of $56,824,000. Of
this total, $49,126,000 is to be funded through connection
fees and will be constructed by the City of Carlsbad. The
remaining $7,698,000 will be funded through development.
When this system is in place, it will provide a sewer to
each of the sewer drainage basins developed in this report.
Chapter 8 - Revenue Program Requirements
There are $49,126,000 worth of improvements to be funded by
the City of Carlsbad recommended in this report. These
facilities will serve an additional 39,380 equivalent
dwelling units. Thus, the cost per equivalent dwelling unit
for the facilities recommended in this report is $1,247.
This amount should be adjusted annually to keep up with
inflation.
Chapter 9 - Reclamation Program
The costs and regulations associated with the use of
reclaimed water make its use prohibitively expensive at the
present time. Facilities are in place which could provide
the backbone of the reclaimed water production and
distribution system if there were users. No additional
monies should be spent on the reclaimed water program until
a user base has been developed.
Table 1-1. Suimnary of Recommended Improvements
Item C ost.-j, thousands of dollars
1987-1989 1990-1994 1995-1999 Beyond 2000
When Needed
for Development Total
Encina Water Pollution
Control Facility
Improvements
11,011 12,492 1,950 0 0 25,453
Ocean Outfall 97 0 9,825 0 0 9,922
Lake Calavera Hills
Water Reclamation Plant 0 0 0 2,633 0 2,633
Interceptor System
Vista/Carlsbad
Interceptors
Lift Stations
Trunkal
1,270
945
0
0
38
0
985
0
0
1,350
442
0
0
0
388
3,605
1,425
388
North Agua Hedionda
Trunks' 0 0 0 0 660 660
South Agua Hedionda
Interceptors
Lift Stations
Trunks'
0
0
0
0
0
0
1,083
850
0
0
850
0
0
0
3,760
1,083
1, 700
3,760
Buena/San Marcos
Interceptors
Lift Stations
Trunks'
0
0
0
0
0
0
0
1,250
0
122
0
0
0
0
1,465
122
1,250
1,465
North Batiquitos
Lift Stations
Trunks' 0
0
833
0
0
0
0
0
0
1,425
833
1,425
City Maintenance
Facility 0 0 500 0 0 500
Monitoring Program 60 100 100 340 0 600
TOTAL 13,383 13,463 16,543 5,737 7,698 56,824
1. Developer Funded Facility.
CONCLUSIONS
2,
3,
The major interceptor system is in place, with the
exception of the South Agua Hedionda Interceptor. The
South Agua Hedionda Interceptor is included as a City
of Carlsbad funded facility west of El Camino Real.
Timing and phasing of this facility requires further
study to insure compatibility with the Growth
Management Plan.
Several improvements will be needed to the
Vista/Carlsbad Interceptor within five years.
The Home Plant Lift Station should be replaced.
5
4. The Lake Calavera Hills Water Reclamation Plant should
not be activated at the present time. The plant should
only be utilized if there is a use for reclaimed water
or if the City of Carlsbad has insufficient capacity at
the Encina Water Pollution Control Facility. There is
approximately a two year start up time to put the
improvements in place which would be needed to operate
the Lake Calavera Hills Water Reclamation Plant.
5. Gravity sewer lines should be installed to all sewage
lift stations in Zone 2 and Zone 7. These stations are
currently used to direct flows toward the Lake Calavera
Hills Water Reclamation Plant. These gravity
interceptors should be constructed in conjuction with
development where possible.
6. The Lake Calavera Hills Water Reclamation Plant and all
lift stations which direct sewage toward it should be
mothballed but maintained so they can be utilized at a
future date.
7. The City of Carlsbad should obtain 13.41 million
gallons per day average flow of treatment capacity at
the Encina Water Pollution Control Facility.
8. The current connection fees should be increased to
assure that adequate funds will be available to meet
the capital improvement program recommended in this
report.
9. An annual monitoring program should be adopted as
described in Appendix C.
ACKNOWLEDGMENTS
For their capable assistance during the course of this
study, we wish to express our appreciation to the following
people: Lloyd Hubbs, City of Carlsbad; Steve Jantz, City of
Carlsbad; and Phillip Carter, City of Carlsbad.
CHAPTER 2
DESCRIPTION OF STUDY AREA
The study area and major sewage drainage basin areas are
shown in Figure 2-1.
STUDY AREA
The study area is the sewer service area of the City of
Carlsbad. About 70 percent of the City of Carlsbad is
contained within the study area. The remainder of the City
of Carlsbad is sewered by the Leucadia County Water District
and the San Marcos County Water District. There are 19,221
total acres in the study area.
The study area is bounded on the north by the City of
Oceanside. The eastern border is formed by the City of
Vista, the Buena Sanitation District and the San Marcos
County Water District. The Leucadia County Water District
provides the southern boundary of the study area and the
Pacific Ocean provides the western boundary.
Figure 2-1 also shows the location of the Encina Water
Pollution Control Facility. The Encina Water Pollution
Control Facility is a regional wastewater treatment plant
and provides sewer service to the City of Carlsbad, the City
of Vista, the Buena Sanitation District, the San Marcos
County Water District, the Leucadia County Water District
and the Encinitas Sanitary District. Since this facility is
located in the City of Carlsbad, major interceptor sewers
from all the other agencies served by this plant transport
wastewater through the City of Carlsbad to this facility.
The City of Carlsbad owns or leases capacity in all of the
interceptors serving the other agencies.
TOPOGRAPHY
In general, the least costly and most efficient operation of
sewage systems requires that planning and construction be
dictated by watershed or topographic boundaries.
There are five major sewage drainage basins within the study
area. These sewage drainage basins are defined by the
existing and planned interceptors within the City of
Carlsbad. The most northerly of the sewage drainage basins
is the Vista/Carlsbad Interceptor drainage basin. This
sewer drainage basin begins at the eastern Carlsbad boundary
along Highway 78 and generally follows Highway 78 to the
Buena Vista Lagoon. At the Buena Vista Lagoon, the basin
turns south along the coast and follows the railroad tracks
past the Agua Hedionda Lagoon to the Encina Water Pollution
Control Facility.
The next sewer drainage basin to the south is the North Agua
Hed ionda Interceptor drainage basin. This sewer drainage
basin begins in Growth Management Zone 7 and follows
westerly along the north shore of the Agua Hedionda Lagoon
to the Vista/Carlsbad Interceptor.
The next basin to the south is the South Agua Hedionda
Interceptor sewer drainage basin. This basin generally
follows the Agua Hedionda Creek from the City of Vista
boundary to the Agua Hedionda Lagoon. The basin then
follows the south shore of the Agua Hedionda Lagoon to the
Vista/Carlsbad Interceptor basin.
The Encina Canyon area is served by two major interceptors.
These interceptors are the Buena Interceptor and the San
Marcos Interceptor. This sewer drainage basin is called the
Buena/San Marcos Interceptor basin since it is served by two
interceptors. This basin also contains a portion of the
Batiquitos Lagoon drainage area. This is also known as the
North La Costa area. This area is planned to be pumped up
to El Camino Real and flow into the San Marcos Interceptor.
Thus, this drainage basin begins at the eastern boundary of
the study area adjacent to the San Marcos County Water
District and crosses the study area ending at the Encina
Water Pollution Control Facility.
The most southerly sewer drainage basin is the North
Batiquitos Interceptor drainage basin. This basin starts at
El Cami no Real and flows westerly along the north shore of
the Batiquitos Lagoon to Interstate 5. At Interstate 5,
this basin turns north and follows along Interstate 5 to the
Encina Water Pollution Control Facility.
The elevation of the study area varies from sea level along
the coast and lagoon shores to just under 600 feet at the
eastern boundary of the study area. This provides a
substantial slope which aids in the design of an efficient
sewage system.
Since sewer lines generally follow the low areas of a
watershed, there are a number of gravity sewers in the City
of Carlsbad which end at lagoons or near the ocean. In
order to convey these lines to a single location, lift
stations are required. Thus, the study area sewer system is
complicated by the fact that it is adjacent to the ocean and
a number of lift stations and force mains are necessary to
collect all the wastewater and convey it to the Encina Water
Pollution Control Facility.
CHAPTER 3
LAND USE AND POPULATION PLANNING
IN STUDY AREA
The study area has reached approximately 40 percent of its
ultimate population. The present estimated population of
the study area is 39,000. The ultimate population of the
study area is projected to be 95,700. The ultimate
population will not be reached until well after the year
2000. Table 3-1 provides the projected population and
number of equivalent dwelling units through the year 2010 as
well as the ultimate population and equivalent dwelling
units of the study area. This table will be used to project
growth trends for the study area.
Table 3-1. Population Estimates for Study Area
Year Population Equivalent Dwelling Units^
Present 39,000 21,555
1990 56,500 25,680
1995 69,000 31,360
2000 81,500 37,050
2005 86,200 42,730
2010 90,900 48,410
Ultimate 95,700 60,935
1. Includes commercial/industrial Equivalent
Dwelling Units. See Appendix A and E for
details.
As part of the Growth Management Plan, the City of Carlsbad
has been split into 25 planning areas. Some of these
planning areas fall into more than one sewer drainage basin.
Thus, these planning areas have been further split in this
report in order to project flows from specific sewer
drainage basins. Figure 3-1 shows the sewer drainage zones
used to project flows.
11
LAND USE
The land use in an area profoundly affects the amount of
sewage generated by that area. In order to project sewage
flows, the land use designation from the City of Carlsbad's
general plan has been used to establish industrial and
commercial square footages. Appendix A provides a summary
of land use by zones.
Current Land Use
Most of the development in the City of Carlsbad is along the
coastal strip. In the northern portion of the City of
Carlsbad, development has proceeded eastward and is nearing
the eastern boundary of the City of Carlsbad. This is the
only portion of the study area which has residential
development east of the coastal strip. There is also
substantial industrial and commercial development within the
City of Carlsbad including a regional shopping center and
the Palomar Airport Business Park.
Projected Land Use
The projected land use of the study area shows greater
commercial and industrial activity than presently found
within the study area. Present commercial and industrial
sewage flows represent only 15 percent of the total sewage
flow from the study area. At build out it is estimated that
these flows will account for one third of the flows from the
study area. Thus, the mixture of development in the study
area should change over time from mostly residential to an
area which has a significant industrial and commercial
contribution. This could affect sewage projections and
peaking factors in the study area.
POPULATION PROJECTIONS
The population projections for the study area were based on
the Comprehensive Planning Organization of the San Diego
Region, Series 6 population projections. The projections
were converted to residential dwelling units based on
information prepared by the City of Carlsbad Planning
Department. These residential dwelling units were divided
into the individual zones shown on Figure 3-1. Appendix A
provides present, approved and future residential dwelling
units for each of the zones.
12
Present Population
At the present time, approximately 60 percent of the
population in the study area resides in the northwest
quadrant. This quadrant is north of Palomar Airport Road
and west of El Camino Real. Development has proceeded from
this quadrant to the east across El Camino Real in the
northern area of the City of Carlsbad and south along the
coast.
Future Population
At build out, the northwest quadrant of the City of Carlsbad
will contain approximately 40 percent of the population of
the study area. Thus, the population will shift both
easterly and southerly from the present center of population
of the study area.
15
16
CHAPTER 4
EXISTING SEWERAGE SYSTEM
The City of Carlsbad wastewater collection system utilizes
about 100 miles of sanitary sewers ranging in size from 6
inches to 54 inches in diameter and 15 lift stations. The
system has generally been laid out to conform to the
watersheds of the Buena Vista, Agua Hedionda, Encina and San
Marcos Creeks and to drain in a westerly direction thereby
allowing the majority of the wastewater to be collected and
transported by gravity. Since the City of Carlsbad is
adjacent to the coast, a large number of lift stations are
required to collect sewage from individual watersheds and
convey it to a wastewater treatment facility.
The City of Carlsbad has two wastewater treatment facilities
that it can utilize. Currently all sewage from the City of
Carlsbad is being treated at the Encina Water Pollution
Control Facility. This facility is jointly owned by six
agencies and has a current design capacity of 22.5 million
gallons per day. The other facility which the City of
Carlsbad could utilize if capital improvements were made is
the Lake Calavera Hills Water Reclamation Plant. This
facility has a design capacity of 1.2 mgd but cannot be
utilized until a connection to the Encina Ocean Outfall is
made.
DESCRIPTION OF EXISTING CONVEYANCE SYSTEM
At ultimate development, there will be five major
interceptors within the City of Carlsbad. Four of these
interceptor systems have been constructed and are now in
use. Each of these existing interceptor systems will be
described in this chapter.
There are two categories of sewers other than interceptor
sewers. They are trunk sewers and collector sewers. Trunk
sewers are defined as sewers serving more than one growth
management zone which have not been previously designated as
interceptor sewers. Collector sewers are sewers which
convey sewage from a single growth management zone. Trunk
sewers are analyzed and described in this chapter. For
information on collector sewers consult individual Growth
Management Zone reports.
17
18
Vista/Carlsbad Interceptor
The Vista/Carlsbad Interceptor starts just west of College
Boulevard along Highway 78 at the Vista Meter. This
interceptor serves all or portions of Growth Management
Zones 1, 2, 3, 7, 22 and 25 and also intercepts flows from
the North and South Agua Hedionda Interceptor systems. This
interceptor is jointly owned by the City of Vista and the
City of Carlsbad. The City of Carlsbad ownership rights in
the interceptor increase in the direction of flow reaching
greater than 50 percent ownership in the most downstream
reaches of the interceptor. Table 4-1 provides engineering
data for the gravity portions of this interceptor. Figure
4-1 shows the location of the interceptor.
The interceptor parallels Highway 78 from College Boulevard
to Jefferson Street. The Buena Vista Lift Station is
located near the intersection of Jefferson Street and
Highway 78. The force main from this lift station conveys
the sewage along Jefferson Street, crosses Interstate 5, and
empties into a gravity system. The gravity system then
follows Jefferson Street to Grand Avenue and then follows
Grand Avenue to the railroad easement. The interceptor then
turns south and follows the railroad easement to the Agua
Hedionda Lagoon. The Agua Hedionda Lift Station is located
on the south side of the lagoon and lifts the sewage up to
the gravity interceptor which follows the railroad easement
to the Encina Water Pollution Control Facility.
Buena Vista Lift Station (Unit C). The Buena Vista Lift
Station is located on Jefferson Street at the head of the
Buena Vista Lagoon and contains three wastewater pumps. All
three pumps are capable of operating at variable speeds by
means of an eddy current coupling between the pump and the
electric motor. The lift station has a capacity of 17 mgd
at the present time. There is a space to add two additional
pumps to the station providing for an ultimate capacity of
26.3 mgd.
Agua Hedionda Lift Station (Unit G). The Agua Hedionda Lift
Station, located on the south side of Agua Hedionda Lagoon,
contains four wastewater pumps. Two of these pumps are
relatively new 12" x 12" x 21" pumps and there are two
older, smaller pumps. All pumps are capable of operating at
variable speeds by means of either an eddy current coupling
or a variable frequency drive. The present capacity of the
station is 24.5 million gallons per day. With the
replacement of the two smaller pumps with larger pumping
units, the capacity of the station could be expanded to 34.5
mgd.
19
Table 4-1. Engineering Data for the Vista/Carlsbad Interceptor
Reach Engineering Data City of Carlsbad Ownership.
Minimum
Size,
in.
Minimum
Slope,
%
Length,
feet
Full Pipe
Capacity,
mgd
Percent Full Pipe
Capacity,
mgd
Full Pipe
Available
Capacity,^
mgd
VCl 36 0.50 6,690 30.0 0 0 0
VC2 42 0.28 2,790 34.0 15.5 5.3 4.7
VC3 36 0.20 3,170 19.5 15.5 3.0 1.6
VC5 27
(24)
0.36 2,500 12.0 27.3 2.6 0.9
VC6 30 0.24 1,180 13.0 27.3 3.3 1.6
VC7 27 1.64 760 25.0 27.3 6.8 4.4
VC8 36 0.10 720 13.8 27.3 3.8 1.0
VC9 36 0.10 1,940 13.8 37.3 5.1 1.5
VCIO 36 0.10 4,330 13.8 37.3 5.1 0.5
VCll 42 0.10 1,370 20.5 37.3 7.6 0.8
VC13 42 0.10 3,520 20.5 51.7 10.6 3.8
VCU 42 0.10 5,080 20.5 51.7 10.6 3.1
VC15 42 0.12 1,760 22.8 51.7 11.8 4.3
VC16 54 0.28 310 67.2 45.24 30.4 22.0
1. Available capacity as of January 1, 1987.
20
BUENA VISTA
LIFT STATION
VISTA METER
STATION
VCI5-
22A ^
ENCINA WATER
POLLUTION CONTROL
FACILITY
LEGEND
EXISTING SEWERAGE
FACILITIES
VISTA/CARLSBAD
INTERCEPTOR BASIN
BOUNDARY
SEWER DRAINAGE ZONE BOUNDARY
FIGURE 4-1
VISTA/CARLSBAD
INTERCEPTOR SYSTEM
2!
North Agua Hedionda Interceptor
The North Agua Hedionda Interceptor was constructed in 1966.
The interceptor starts at El Camino Real and flows westerly
along the north shores of the Agua Hedionda Lagoon to the
Foxes Landing Lift Station. The Foxes Landing Lift Station
pumps the sewage up and across Interstate 5 into a short
gravity interceptor which flows to the Vista/Carlsbad
Interceptor. The North Agua Hedionda Interceptor enters the
Vista/Carlsbad Interceptor just upstream of the Agua
Hedionda Lift Station. This interceptor is entirely owned
by the City of Carlsbad and conveys only the City of
Carlsbad's sewage. Table 4-2 provides engineering data for
the gravity portions of this interceptor and Figure 4-2
shows its location. This interceptor serves parts of Growth
Management Zones 1, 2, 7 and 14.
Foxes Landing Lift Station. The Foxes Landing Lift Station
contains three pumps. Two of the pumps are the original
units. The third, larger pump has recently been installed.
The present capacity of this station is 3.3 mgd. The
capacity of the station could be increased by replacing the
two smaller, older pumps with larger units.
Trunk Sewers. Figure 4-2 shows the existing trunk sewers in
this basin. Trunk NAHTIB serves parts of Growth Management
Zones 1, 2, 7 and 14.
23
Table 4-2. Engineering Data for the North Agua Hedionda
Interceptor
Reach Minimum
Size,
in.
Minimum
Slope,
%
Length,
feet
Full Pipe
Capacity,^
mgd
Full Pipe
Available
Capacity, 2
mgd
NAHl 21 0.36 1,710 6.14 5.81
NAH2 24 0.10 4,570 4.62 4.07
NAH3 24 oao 4,680 4.62 2.66
NAH4 Siphons --200 6.29 4.33
NAH5 24 0.15 3,940 5.66 3.28
NAH7 18 1.0 1,360 6.79 4.41
NAHTIB 8 1.4 4,000 0.93 -0.533
1.
2.
3.
City of Carlsbad retains 100 percent ownership of all reaches.
Available capacity as of January 1, 1987.
This pipe is in the process of being replaced.
ro
Ul
LEGEND
EXISTING SEWERAGE FACILITIES
NORTH AGUA HEDIONDA BASIN
BOUNDARY
SEWER DRAINAGE ZONE BOUNDARY
o
VISTA/CARLSBAD
INTERCEPTOR
AGUA HEDIONDA
LIFT STATION
N
N.T.S.
FIGURE 4-2
NORTH AGUA HEDIONDA
INTERCEPTOR SYSTEM
Buena/San Marcos Interceptor System
There are two major interceptors which follow the Encina
Canyon to the Encina Water Pollution Control Facility.
These are the Buena Interceptor and the San Marcos
Interceptor. Both of these interceptors serve the Buena/San
Marcos Interceptor drainage basin. All portions of Growth
Management Zones 4, 5, 6, 10, 13, 17, 18 and 20 are served
by these interceptors.
Buena Interceptor. The Buena Interceptor flows through the
Encina Canyon to the Encina Water Pollution Control
Facility. This interceptor is owned by the Buena Sanitation
District and was constructed in 1964. The City of Carlsbad
has a lease of capacity in this line. The amount of leased
capacity increases in the downstream reaches of this
interceptor. Table 4-3 provides engineering data for the
interceptor and a description of the City of Carlsbad's
capacity rights in the interceptor. Figure 4-3 shows the
location of the interceptor.
The Buena Interceptor begins at the corner of El Camino Real
and Palomar Airport Road at the discharge of the Buena force
main and flows through the City of Carlsbad's industrial
park. The interceptor then parallels Palomar Airport Road
until just before Interstate 5, where the interceptor turns
away from the road and crosses the freeway to the Encina
Water Pollution Control Facility.
San Marcos Interceptor. The San Marcos Interceptor is owned
by the San Marcos County Water District, but the City of
Carlsbad has capacity rights of 5 mgd throughout the length
of the interceptor. The interceptor begins at the end of
the San Marcos siphon near the intersection of Camino Vida
Roble and El Camino Real. It then flows westerly through
the industrial park. The interceptor then follows Palomar
Airport Road westerly adjacent to the Buena Interceptor.
Table 4-4 provides a description of the reaches and the City
of Carlsbad ownership in the San Marcos Interceptor. Figure
4-3 shows the location of the interceptor.
27
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28
BSM8
ENCINA
WATER
POLLUTION
CONTROL
FACILITY
EXISTING SEWERAGE FACILITIES
BUENA/SAN MARCOS INTERCEPTOR
BASIN BOUNDARY
SEWER DRAINAGE ZONE BOUNDARY
FIGURE 4-3
BUENA/SAN MARCOS
INTERCEPTOR SYSTEM
North Batiquitos Interceptor
The majority of the North Batiquitos Interceptor is owned
100 percent by the City of Carlsbad. The downstream reaches
of this interceptor are owned jointly by the City of
Carlsbad, the Leucadia County Water District and the
Encinitas Sanitary District. Table 4-5 provides a
description of the reaches and ownerships in the North
Batiquitos Interceptor. Figure 4-4 shows the location of
the interceptor. This interceptor serves all or portions of
Growth Management Zones 4, 6, 9, 19, 20, 21 and 22.
The North Batiquitos Interceptor begins on the north shore
of the Batiquitos Lag oon near El Camino Real. The
interceptor follows the north shore of the lagoon to the
North Batiquitos Lift Station. This lift station pumps the
sewage up and across Interstate 5. The interceptor then
continues in a northerly direction and reaches the railroad
easement near Poinsettia Lane. The interceptor then follows
northerly along the railroad easement to an intersection
point with the Vista/Carlsbad Interceptor outside of the
Encina Water Pollution Control Facility.
North Batiquitos Lift Station. The North Batiquitos Lift
Station is currently a package Smith and Loveless lift
station. This package lift station was installed in 1976.
This sewage lift station cannot be expanded effectively and
is scheduled to be replaced when additional capacity is
needed. The present capacity of this station is 900 gallons
per minute.
Trunk Sewers. Table 4-5 provides a description of the
existing trunk sewer in this basin. Trunk sewer NBT3B
serves parts of Growth Management Zones 4 and 20.
Other Existing Lift Stations
There are nine lift stations which serve individual Growth
Management Zones in the City of Carlsbad. Some of these
sewage lift stations are permanent and some will eventually
be abandoned. Appendix F provides information on each of
these stations.
31
Table 4-5. Engineering Data for the North Batiquitos Interceptor
Reach Engineering Data City of Carlsbad Ownership
Minimum
Size,
in.
Minimum
Slope,
%
Length,
feet
Full Pipe
Capacity,
mgd
Percent Full Pipe
Capacity,
mgd
Full Pipe
Available
Capacity,^
mgd
NBl 15 0.15 2,450 1.62 100 1.62 1.40
NB2 18 0.10 2, 180 2.14 100 2.14 1.92
NB3 21 0.10 1,970 3.24 100 3.24 3.02
NB4 24 0.10 4,430 4.62 100 4.62 4.40
NB6 18 0.80 1,930 6.07 100 6.07 5.39
NB7 21 0.20 3,300 4.57 100 4.57 3.77
NB8 27 0.16 3,100 8.00 100 8.00 7.02
NB9 39 0.16 1,430 21.3 40 8.52 7.54
NBIO 48 0.09 1,000 27.8 40 11.12 10.14
NBT3B 8 0.40 5,000 0.49 100 0.49 0.02
S5
1. Available capacity as of January 1, 1987.
OJ
OJ
LEGEND
EXISTING SEWERAGE
FACILITIES
NORTH BATIQUITOS
INTERCEPTOR BASIN
BOUNDARY
SEWER DRAINAGE
ZONE BOUNDARY
FIGURE 4-4
NORTH BATIQUITOS
INTERCEPTOR SYSTEM
WASTEWATER TREATMENT FACILITIES
The two treatment facilities which may be utilized by the
City of Carlsbad are the Encina Water Pollution Control
Facility and the Lake Calavera Hills Water Reclamation
Plant. The present capacity of the Encina Water Pollution
Control Facility is 22.5 million gallons per day and the
City of Carlsbad owns 5.716 million gallons per day of this
capacity. The capacity of the Lake Calavera Hills Water
Reclamation Plant is 1.2 million gallons per day.
Encina Water Pollution Control Facility (Unit I)
In September, 1965, the Encina Water Pollution Control
Facility commenced operation. The original primary
treatment capacity, on the average dry weather flow basis,
was 4.5 million gallons per day. Primary treatment capacity
has been subsequently increased to 13.75 million gallons per
day during three major enlargement phases referred to as
Phase I, II, and IIA.
Phases III and IIIA enlarged and upgraded the facility
providing for full secondary treatment of 22.5 million
gallons per day, with provisions for expansion to an
ultimate average dry weather flow of 45 million gallons per
day through modular addition to the basic unit processes.
A Phase IV project report is currently being prepared to
investigate the need for an expansion beyond 22.5 million
gallons per day.
The treatment processes consist of screening, grit removal,
primary sedimentation, activated sludge secondary treatment,
secondary sedimentation, anaerobic sludge digestion and belt
press sludge dewatering. At the present time the plant is
operated as an advanced Primary Treatment Plant.
Treatment Plant Ownership and Capacity (Unit I). Table 4-6
shows the percentage of ownership and capacity in million
gallons per day for each of the agencies in the Encina Water
Pollution Control Facility.
The City of Carlsbad owns 25.4 percent of the plant for a
capacity of 5.716 million gallons per day.
35
Table 4-6. Current Encina Water Pollution Control Facility
Ownership and Capacity
Participant 2
Capacity,
mgd
Ownership,
percent
Vista 6.75 30.00
Carlsbad 5.716 25.40
Buena 1.034 4.59
San Marcos 4.00 17.78
Leucadia 3.75 16.67
Encinitas 1.25 5.56
Total 22.50 100.00
1. Section 6 - Seventeenth Supplement,
2. Average daily flow.
Encina Ocean Outfall System (Unit J). The original outfall
began operation concurrently with the plant in September,
1965. At that time, the entire outfall was 48-inch diameter
reinforced concrete pipe. The outfall was 6,600 feet long;
1,100 feet was land outfall and 5,500 feet was ocean
outfall. The outfall ended in approximately 100 feet of
water. The last 325 feet of the outfall was the diffuser
section, which originally contained 27 ports, each 6 inches
in diameter. The ports were spaced at 12.5-foot centers on
alternate sides of the pipe.
In 1973, the ocean section of the outfall was extended 2,300
feet using 72-inch diameter reinforced concrete pipe. A new
diffuser section was installed in the final 800 feet of the
extension and the 27 ports in the old diffuser section were
plugged. The average water depth in the new diffuser
section is 159 feet, and water discharged through the
outfall remains submerged under almost all conditions. The
new diffuser section contains 138 ports.
Table 4-7 provides
and capacity. a breakdown of ocean outfall ownership
36
Table 4-7. Current Encina Ocean Outfall Ownership and
Capacity Rights
Agency Ownership, Capacity Rights,^
percent mgd
Vista 16.67 6.75
Carlsbad 28.66 11.61
Buena 13.00 5.27
San Marcos 16.67 6.75
Leucadia 16.67 6.75
Encini tas 8.33
— _
3.37
1. Capacity rights are for peak wet weather flow and based
on an outfall capacity of 40.5 mgd.
Lake Calavera Hills Water Reclamation Plant
Construction of the Lake Calavera Hills Water Reclamation
Plant as it now exists was completed in 1981. Since that
time, the plant has been turned over to the City of Carlsbad
for operation and maintenance. The plant is now owned
entirely by the City of Carlsbad and all future upgrades and
all costs for operation and maintenance of the plant are
borne by the City of Carlsbad. A detailed description of
this plant can be found in Appendix D. The design capacity
of the plant is 1.2 million gallons per day. Table 4-8
provides a description of the major unit processes at the
plant.
Table 4-8. Lake Calavera Hills Water Reclamation Plant
Capacity of Major Process Units
Process Quantity Size Capacity Each
Comminutor 1 2 mgd Peak
Oxidation Ditch
Reactors
2 650,000 gallons 0.6 mgd Average
Clarifiers 2 113,700 gallons 0.6 mgd Average
Chlorination
Tanks
1 43,000 gallons 2 mgd (30 minutes)
Aerobic
Digester
1 75,000 gallons
Belt Press
Sludge
Dewa taring
1 1/2 meter
Emergency
Power
1 300 KV
37
38
CHAPTER 5
WASTEWATER FLOW PROJECTION CRITERIA
In order to determine deficiencies in the existing system
and size future wastewater facilities, it is necessary to
establish existing flows and project future flows. Flow
estimates are based on either population or equivalent
dwelling units. To ensure compatibility with the City of
Carlsbad's Growth Management Plan, equivalent dwelling units
have been used to project flows.
FLOW FACTORS
Some elements of the wastewater collection, treatment and
disposal system are sized based on average flow. Other
elements are sized based on peak flows. Thus, both average
daily flow and peak flow must be projected in order to size
all elements of the wastewater collection, treatment and
disposal system.
Average Daily Flow
The average daily flow from the City of Carlsbad was
projected using 220 gallons per day per equivalent dwelling
unit. Three land use categories were adopted for the City
of Carlsbad to project future flows. These categories are
residential, commercial and industrial. Table 5-1 provides
a summary of the unit flow generation factors used to
project average daily flows in this report. Appendix E
provides backup material showing how these generation
factors were derived. Flow generation factors should be
evaluated periodically as a part of the flow monitoring
program.
Peak Flows
The ratio of the peak flow to the average flow varies with
the number of equivalent dwelling units being projected.
The larger the number of equivalent dwelling units, the
smaller the peaking factor. Figure 5-1 was utilized to
convert average flows to peak flows.
39
Table 5-1. Unit Flow Generation Factors
General
To convert Equivalent Dwelling Units to flow assume 220
gallons per day average flow.
Commercial Property
To convert raw land to square feet of building space
assume 30 percent coverage.
To convert improved pads to square feet of building
space assume 40 percent coverage.
To convert square feet of a building to Equivalent
Dwelling Units assume 1,800 square feet per EDU.
Industrial Property
To convert raw land to square feet of building space
assume 30 percent coverage.
To convert improved pads to square feet of building
space assume 40 percent coverage.
To convert square feet of building to Equivalent
Dwelling Units assume 60 percent of space is warehouse
and 40 percent is office. For warehouse space 5,000
square feet equals one EDU and for office 1,800 square
feet equals one EDU.
FLOW PROJECTIONS
In order to size the conveyance system, flows
for each of the sewer drainage basins within
Carlsbad. These individual basins were
contributions to the conveyance system to
conveyance system for deficiencies and future
5-2 provides a summary of the existing, approv
flows and equivalent dwelling units for the
Appendix A provides the same information for
individual sewer drainage basins within
Carlsbad.
were projected
the City of
then used as
analyze the
needs. Table
ed and future
study area.
each of the
the City of
Table 5-2. Existing and Future Wastewater Flow Estimates
Land Use Exis ting Approved Future Totals Land Use
EDUs Flow,
mgd
EDUs Flow,
mgd
EDUs Flow,
mgd
EDUs Flow,
mgd
Residential
Commercial
Industrial
18,442
1.664
1,835
4.06
0.37
0.40
3,606
779
2,767
0.79
0.17
0.61
20,462
6,462
4,943
4.50
1.42
1.09
42,510
8,905
9,545
9.35
1.96
2.10
Total 21,941 4.83 7,152 1.57 31,867 7.01 60,960 13.41
40
o
UJ
CD
<
cr
LiJ
<
UJ
0.
<
cr.
O.OI 0.02
OR LESS
0.0
AVERAGE FLOW (MILLION GALLONS PER DAY)
FIGURE 5-1
PEAKING FACTOR CHART
Table 5-3 provides an estimate of total flow from the study
area in five year increments. This table is based on
estimated population growth and industrial growth rates.
This table will be used to determine when additional
wastewater conveyance and treatment facilities will need to
be constructed.
Table 5-3. Wastewater Flow Projection
Flow,
Year mgd
Present 4.74
1990 5.65
1995 6.90
2000 8.15
2005 9.40
2010 10.65
Ultimate 13.41
43
44
CHAPTER 6
DESIGN CRITERIA AND UNIT CONSTRUCTION COSTS
DESIGN CRITERIA
The design criteria for this report were based on the City
of Carlsbad standards and standards of the industry.
Gravity Sewers
All gravity sewers have been designed to convey peak wet
weather flow. For pipes with a diameter of 10 inches and
smaller, the sewers have been designed to convey this flow
when flowing one-half full. For pipes with a diameter of 12
inches and larger, the sewers have been designed to convey
peak wet weather flows when flowing three-fourths full by
depth. Manning's equation with n = 0.013 was used to size
all gravity sewers.
When projected flows were found to exceed the full pipe
capacity of existing gravity sewers, a replacement sewer was
designed per the above criteria. The replacement sewer was
designed to convey all sewage generated in its service area
and allow the existing sewer to be abandoned.
All new sewers were designed to maintain a minimum velocity
of 2 feet per second to prevent the deposition of solids.
Prior to actual replacement of existing sewers, flow
monitoring should be conducted to verify the analyses in
this report.
Force Mains and Sewage Lift Stations
Sewage lift stations and force mains were designed as a
unit. In general, all force mains were designed to maintain
velocities between 3 and 5 feet per second. Hazen-Williams'
equation with c = 120 was used to determine the losses in
force mains. When an existing force main was inadequate to
convey needed flows, a parallel force main was designed.
The new force main was designed to convey only the
additional capacity needed. It was assumed that the old
force main would remain in service.
All lift stations recommended in this report were designed
in accordance with the following criteria. Each station was
designed with a wet well and a separate dry well with at
least two flooded suction centrifugal pumps. Each station
was designed with standby pumping capacity so if a station
45
contains only two pumps each should be capable of pumping
the total design flow. Each station was also designed with
emergency power generation. All of the above parameters
should be considered as guidelines and may change
substantially during final design.
UNIT COSTS
The unit costs used to estimate costs in this report were
based on recent construction bid prices. The costs in this
report are based on an Engineering News Record Los Angeles
Construction Cost Index of 5,500.
Gravity Sewers and Force Mains
Table 6-1 presents the unit costs used to develop costs for
gravity sewers and force mains. These costs include a 35
percent allowance for construction contingencies, legal,
engineering and administrative costs. The costs per foot
include manholes.
Table 6-1. Unit Construction Costs 1
Cost Per Foot,
Pipe Type/Size-Inches dollars
Gravity Sewers
8 65
10 75
12 90
15 105
18 120
21 135
24 150
27 175
30 200
36 225
42 275
48 325
54 375
60 425
66 475
Force Mains
6 45
8 55
10 65
12 80
16 100
18 UO
21 125
24 140
1. ENRLA-CCI 5,500 (10-87)
46
Sewage Lift Stations
The cost for each sewage lift station was estimated as a
lump sum based on actual construction costs for similar
facilities.
47
48
CHAPTER 7
IMPROVEMENT PROGRAM
This chapter provides a description of the needed
improvements to the conveyance system and treatment plants.
CONVEYANCE SYSTEM IMPROVEMENTS
There are improvements needed to the existing interceptors
and a new interceptor is needed. Tables 7-1 through 7-5 and
Figures 7-1 through 7-5 show the recommended improvements to
the City of Carlsbad conveyance system. These figures and
tables are arranged on the basis of the five sewage drainage
basins within the City of Carlsbad. The total estimated
costs for improvements to the trunk and interceptor system
is $56,824,000. The City of Carlsbad will fund through the
connection fee process $49,126,000 of this amount.
Developers will fund $7,698,000 of this amount.
Facilities shown in yellow in Figure 7-1 through 7-5 are
facilities which will be constructed by the City of Carlsbad
through the use of connection fees. The developer funded
facilities are shown in red. The connection fees are
established on the basis of the City of Carlsbad funding
only interceptor and interceptor lift station improvements.
All improvements to trunk line collector sewers will be
borne by the developers.
Table 7-1. Improvements to
Drainage Basin
Vlsta/Carlsbad Interceptor Sewage
IMPROVEMENTS TO EXISTING INTERCEPTORS
Reach Location Size,^ Length,
feet
Total CBJI Year Reach Location
in.
Length,
feet Cost,
$
Ownership ,^
Z
Cost,
$
Needed
VC3 Highway 78 East
of Buena Vista
Lagoon
42 3,170 871,750 15.5 135,120 Beyond
2000
VC5 Jefferson Street 36 2. 500 562,500 27.3 153,560 1989
VC6 Jefferson Street
Arbuckle to Grand
42 1,180 324,500 27.3 88,590 1989
VC7 Grand Avenue 30 760 152,000 27.3 41,500 1989
VC8 Grand Avenue 48 720 234,000 27.3 63,880 1989
VC9 Washington Street
Grand to Oak
48 1.940 630,500 37.3 235,180 1989
VCIO Washington Street
Oak to Olive
48 4,330 1,407,250 37.3 524,900 1989
VClOA Chestnut Lateral 12 1,800 162,000 100 162,000 1989
VCll AT & SF R.R.
Olive to Agua
Hedionda Lagoon
54 1,370 513,750 37.3 191,630 Beyond
2000
49
Table 7-1. Improvements to Vista/Carlsbad
Drainage Basin (Continued)
Interceptor Sewage
IMPROVEMENTS TO EXISTING INTERCEPTORS
Reach
VC13
VCl 4
VCl 5
Loca tion
AT S SF R.R.
Agua Hedionda
Lagoon to Cannon
AT « SF R.R. Cannon
to Palomar Airport
Road
Avenida Encinas
Palomar Airport
Road to Encina
Water Pollution
Control Facility
Entrance
Size, 1
in.
54
54
54
Length,
feet
3,520
5,080
1,760
Total
Cost,
$
1,320,000
1,905,000
660,000
Ownership
X
CajlahaH
51.7
51.7
51.7
Subtotal Interceptor Improvements
Cost,
$
682,440
984,890
341,220
3,604,910
Year
Needed
IMPROVEMENTS TO LIFT STATIONS
Beyond
2000
1997
Beyond
2000
Description of Improvements Size, Length, Total Carlsbad Year
in. feet Cost,
$
Ownership, % Cost,
$ Needed
Buena Vista Lift Station
Add Fourth Pump — 128,000 15.5 20,000 1989
Add Fifth Pump and
Force Main Improvements
— 531,000 15.5 82,000 Beyond
2000
Agua Hedionda Lift Station
Add Third Pump and
Miscellaneous Improvements
— — 110,000 40.5 45,000 1989
Add Fourth Pump — 95,000 40.5 38,000 1990
Relocate Station — — 888,000 40.5 360,000 Beyond
2000
Home Plant Lift Station
Relocate Station — 750,000 100 750,000 1989
Force Main 10 2,000 130,000 100 130,000 1989
Subtotal Lift Station Improvements 1,425,000
Subtotal City of Carlsbad Funded Improvements 5,029,910
CONSTRU CTION OF NEW TRUNK SEWERS
Reach Location Size, ' Length, Total Carl shad Year
in. feet Cost,
$
Ownership ,^ % Cost,
$
Needed
VCTIA Buena Vista Creek 8 1,500 97,500 100 97,500 (3)
VCTIB Buena Vista Creek 8 1,000 65,000 100 65,000 (3)
VCTIC Buena Vista Creek 10 3,000 225,000 100 225,000 (3)
Subtotal Developer Funded Improvements 387,500
TOTAL 5,417,410
Sizes recommended are based on ultimate flows from the City of
Vista and the City of Carlsbad.
Note: -Reaches VC3, VC5, VC6, VC7 and VC13 are recommended for
improvements because of projected Vista flows exceeding
full pipe capacity, Carlsbad does not exceed existing
capacity rights.
-Reaches VC8, VC9, VCIO, VCll, VCU and VC15 are recommended
for improvements due to both the City of Vista and the
City of Carlsbad exceeding existing capacity rights.
These are current Carlsbad ownership percentages. They may
change to reflect a larger need by Carlsbad or Vista when
upgrading of the sewers is done.
As required for development.
50
BUENA VISTA
LIFT STATION
VISTA METER
STATION
HOME PLANT
LIFT STATION
-
/•^
\\\
ej •V
\\\^
VC9
CITY OF CARLSBAD
FUNDED IMPROVEMENTS
DEVELOPER FUNDED
MPROVEMENTS
EXISTING SEWERAGE
FACILITIES
VISTA/CARLSBAD
NTERCEPTOR BASIN
BOUNDARY
SEWER DRAINAGE
ZONE BOUNDARY
ENCINA WATER POLLUTION CONTROL
FACILITY FIGURE 7-1
IMPROVEMENTS TO
VISTA/CARLSBAD
INTERCEPTOR SYSTEM
51
ro
LEGEND
DEVELOPER FUNDED IMPROVEMENTS
EXISTING SEWERAGE FACILITIES
NORTH AGUA HEDIONDA BASIN
BOUNDARY
SEWER DRAINAGE ZONE BOUNDARY
VISTA/CARLSBAD
INTERCEPTOR
AGUA HEDIONDA
LIFT STATION
N.T.S
FIGURE 7-2
IMPROVEMENTS TO
NORTH AGUA HEDIONDA
INTERCEPTOR SYSTEM
Table 7-2. Improvements to North Agua Hedionda Interceptor
Sewage Drainage Basin
IMPROVEMENTS TO EXISTING TRUNK SEWERS
Reach Location Size,
in.
Length,
feet
Total
Cost,
$
Year
Needed
NAHTIB Kelly Drive 12 4,000 360,000 (1)
CONSTRUCTION OF NEW TRUNK SEWERS
Reach Location Size,
in.
Length,
feet
Total
Cost,
$
Year
Needed
NAHTIA Tamarack Ave. 10 4,000 300,000 (1)
Total Developer Funded Improvements 660,000
1. As required for development.
Table 7-3. Improvements to South Agua Hedionda
Interceptor Sewage Drainage Basin
CONSTRUCTION OF NEW INTERCEPTORS
Reach Location Size,
in.
Length,
feet
Total
Cost,
$
Year
Needed
SAHl Hidden Valley Road 21 2.320 313,200 1995
SAH2 Hidden Valley Road 21 2,200 297,000 1995
SAH4 Future Cannon Road 21 3,500 472,500 1995
Subtotal for New Interceptors 1,082,700
LIFT STATION IMPROVEMENTS
Description of Improvements Size,
in.
Length
feet
Total
Cost,
$
Year
Needed
South Agua Hedionda
Lift Station
Stage 1 Lift Station — — 514,000 1995
Sta ge 1 Force Main 24 2,400 336,000 1995
Stage 2 Lift Station — — 550,000 2000
Stage 2 Force Main 21 2,400 300,000 2000
Subtotal Lift Station Improvements 1,700,000
Subtotal City of Carlsbad Funded Improvements 2,782,700
CONSTRUCTION OF NEW TRUNK SEWERS
Reach Location Size,
in.
Length,
feet
Total
Cost,
$
Year
Needed
SAHTIA Carlsbad Raceway 8 1,000 65,000 (1)
SAHTIB Agua Hedionda Creek 12 3,500 315,000 (1)
SAHTIC Agua Hedionda Creek 15 3, 700 388,500 (1)
SAHTID Sunny Creek Road 15 3, 500 367,500 (I)
SAHTIE Rancho Carlsbad
Sunny Creek
15 4, 540 476,700 (1)
SAHTIF Future College Blvd. 8 2,000 130,000 (1)
SAHTIG El Camino Real 18 2, 500 300,000 (1)
SAHT2A Future Cannon Road 10 6,300 472,500 (1)
SAHT2B Future College Blvd. 8 3,000 195,000 (1)
SAHT2C Future Cannon Road 15 3,500 367,500 (1)
SAHT3A Future Macario Canyon
Road
8 1,500 97,500 (1)
SAHT3B Future Macario Canyon
Road
12 6,500 585,000 (1)
Subtotal Developer Funded Improvements 3,760,200
TOTAL 6,542,900
1. As required for development.
54
ENCIN
WATER
POLLUTI
CONTRO
FACILITY
CITY OF CARLSBAD FUNDED
IMPROVEMENTS
DEVELOPER FUNDED IMPROVEMENTS
EXISTING SEWERAGE FACILITIES
BUENA/SAN MARCOS INTERCEPTOR
BASIN BOUNDARY
SEWER DRAINAGE ZONE BOUNDARY
FIGURE 7-4
IMPROVEMENTS TO
BUENA/SAN MARCOS
INTERCEPTOR SYSTEM
Table 7-4. Improvements to Buena/San Marcos Interceptor Sewage
Drainage Basin
IMPROVEMENTS TO EXISTING INTERCEPTORS
Ul
CONSTRUCTION OF NEW TRUNK SEWERS
Computer runs indicate BSM2 will not exceed capacity in the future;
however, flow monitoring indicates future flows will exceed full pipe
capacity and therefore a replacement pipe is recommended.
Cost based on old-line ownership percent.
As required for development.
Reach Location Size, Length, Total Carlsbad Year
in. feet Cost,
$
Ownership, % Cost ,^
$
Needed
BSM2 1 Camino Vida Roble 21 4,690 633,150 19.2 121,600 Beyond
2000
LIFT STATION IMPROVEMENTS
Description of Improvements Size, Length, Total Carlsbad Year
in. feet Cost,
$
Ownership,
%
Cost,
$
Needed
North La Costa Lift Station
Construct Station — — 750,000 100 750,000 1996
Force Main 16 5,000 500,000 100 500,000 1996
Subtotal Lift Station Improvements 1,250,000
Subtotal City of Carlsbad Funded Improvements 1,371,600
Reach Location Size, Length, Total Carlsbad Year
i n. feet Cost,
$
Ownership,
. %
Cost,
$
Needed
BSMTIA Future Carrillo Way 12 2,000 180,000 100 180,000 (3)
BSMTIB Serves 6B 8 1,000 65,000 100 65,000 (3)
BSMTIC Future Carrillo Way 12 1,000 90,000 100 90,000 (3)
BSMTID Future Carrillo Way 15 3,700 388,500 100 388,500 (3)
BSMTIE Serves 17A 10 3,400 255,000 100 255,000 (3)
BSMTIF North of La Costa
Golf Course
15 1. 200 126,000 100 126,000 (3)
BSMT2 Laurel Tree Road 12 4,000 360,000 100 360,000 (3)
Subtotal Developer Funded Improvements 1,464,500
TOTAL 2,836,100
00
Table 7-5. Improvements to North Batiquitos Interceptor
Sewage Drainage Basin
LIFT STATION IMPROVEMENTS
Description of Improvements Size,
in.
Length,
feet
Total
Cost,
$
Year
Needed
North Batiquitos Lift
Station
Reconstruct Station — 750,000 (1)
Add ^orce Main 6 1,840 82,800 (1)
Subtotal City of Carlsbad Funded Improvements 832,800
IMPROVEMENTS TO EXISTING TRUNK SEWERS
Reach Location Size,
in.
Length,
feet
Total
Cost,
$
Year
Needed
NBT3B Daisy Avenue and
Batiquitos Lagoon
12 5,000 450,000 (1)
CONSTRUCTION OF NEW TRUNK SEWERS
Reach Location Size,
in.
Length,
feet
Total
Cost,
$
Year
Needed
NBTl 19C 10 3,000 225,000 (1)
NBT2 19B 12 7,500 675,000 (1)
NBT3A 4B 10 1,000 75,000 (1)
Subtotal New Trunk Sewers 975,000
Subtotal Developer Funded Improvements 1,425,000
TOTAL 2,257,800
1. As required for development,
LEGEND
CITY OF CARLSBAD
FUNDED IMPROVEMENTS
DEVELOPER FUNDED
IMPROVEMENTS
EXISTING SEWERAGE
FACILITIES
NORTH BATIQUITOS
INTERCEPTOR BASIN
BOUNDARY
SEWER DRAINAGE
ZONE BOUNDARY
FIGURE 7-5
IMPROVEMENTS TO
NORTH BATIQUITOS
INTERCEPTOR SYSTEM
WASTEWATER TREATMENT SYSTEM IMPROVEMENTS
The City of Carlsbad has the ability to treat sewage either
at the Encina Water Pollution Control Facility or the Lake
Calavera Hills Water Reclamation Plant. Recommended
improvement programs for both of these facilities are
provided.
The City of Carlsbad has an ultimate sewage treatment
capacity need of 13.41 million gallons per day. For the
purposes of cost estimating for future facilities, it is
assumed that all 13.41 million gallons per day of capacity
will be obtained at the Encina Water Pollution Control
Facility.
The effluent disposal line and filtration system
improvements discussed in this chapter would be added to the
Lake Calavera Hills Water Reclamation Plant to allow it to
be used as a reclamation facility. In conjunction with the
improvements to the Lake Calavera Hills Water Reclamation
Plant, gravity outfalls will be provided to all lift
stations. This will enable the lift stations to be turned
off when the Lake Calavera Hills Water Reclamation Plant is
not in operation.
Encina Capital Improvement Program
The capital improvement program at the Encina Water
Pollution Control Facility includes the Phase IV expansion,
the Phase V expansion, the solids management program and
improvements to the ocean outfall. Table 7-6 provides times
and cost estimates for these improvements. For the purposes
of estimating the costs for improvements to the Encina Water
Pollution Control Facility, the ultimate capacity of the
plant has been established as 45 million gallons per day.
In order for the City of Carlsbad to obtain 13.41 million
gallons per day of capacity, they will have to own 29.8
percent of the plant. At the present time, the City of
Carlsbad owns only 25.4 percent of the plant.
61
Table 7-6. Improvements to the Encina Water Pollution Control Facility
Carlsbad Cost.l thousands of dollars
Project 1987-1989 1990-1994 1995-1999 Beyond 2000 Total
Phase IV 8,995 8,995 17,990 Phase IV 8,995 8,995 17,990
Solids Management
Stage 1
2,016 3,497 5,513 Solids Management
Stage 1
2,016 3,497 5,513
Solids Management
Stage 2
1,950 1,950 Solids Management
Stage 2
1,950 1,950
Outfall Pump 3
Outfall Pump 4
and Surge Tower
97 97
140
Outfall Pump 3
Outfall Pump 4
and Surge Tower
97
140
97
140
Outfall Pump 3
Outfall Pump 4
and Surge Tower 140
97
140
Parallel Outfall 9,685 9,685 Parallel Outfall 9,685 9,685
Totals 11,108 12,492 11,775 0 35,375
1. All costs are based on the City of Carlsbad's needed plant
ownership of 29.8% and existing outfall ownership of 28.66%.
Phase IV Project. The Phase IV project will increase the
capacity of the Encina Water Pollution Control Facility from
22.5 million gallons per day to 35.5 million gallons per
day. With additional modifications, the Encina Water
Pollution Control Facility could be expanded to 45 million
gallons per day. The extent of these modifications is not
known at the present time, but they are being built into the
Phase IV project. The cost estimate for the City of
Carlsbad's share of the Phase IV project includes a 20
percent add-on to estimated costs to expand the capacity of
the plant from 35.5 million gallons per day to 45 million
gallons per day. The cost estimate also includes a buy-in
to the present facilities to increase the City of Carlsbad's
ownership from 25.4 percent to 29.8 percent. Thus, the
total cost for the City of Carlsbad in the Phase IV project
is estimated to be $17,990,000 and it will provide the City
of Carlsbad with a total of 13.41 million gallons per day of
treatment capacity.
Solids Management Program. The solids management program is
an effort to treat the solids to a level that will permit
disposal in a sanitary landfill. Present regulations have
moisture content requirements for sewage sludges. The
Encina Water Pollution Control Facility's sludge does not
meet these requirements at the present time. Phase I of the
62
solids management program is scheduled to be completed by
1991 and will cost the City of Carlsbad $5,513,000. Phase
II of the solids management program will be needed around
the year 2000 and will cost the City of Carlsbad $1,950,000.
All estimates are based on a City of Carlsbad ownership of
29.8 percent, and a solids disposal . solution limited to the
Encina Water Pollution Control Facility.
Oc ean Outfall Improvements. There are three major
improvements needed to the ocean outfall. The first two
involve the addition of pumps to the effluent pump station.
The addit ion of the third pump to the effluent pump station
is scheduled to be completed by 1990 and will cost the City
of Carlsbad $97,000. The fourth pump is not scheduled to be
needed until the year 2000 and will cost the City of
Carlsbad $140,000. Around the year 2000 there will be a
need for a parallel ocean outfall and this will cost the
City of Carlsbad $9,685,000. All estimates are based on a
City of Carlsbad ownership of 29.8 percent.
Lake Calavera Hills Water Reclamation Plant
The Lake Calavera Hills Water Reclamation Plant was
constructed in 1981 to provide sewage treatment for the Lake
Calavera Hills planned community and developments east of El
Camino Real in the proximity of the Lake Calavera Hills
development. This facility has never been operated as a
wastewater treatment plant and additional improvements are
needed for it to operate. Appendix D to this report
provides a detailed discussion of the Lake Calavera Hills
Water Reclamation Plant. This plant will only be operated
if there is a need for reclaimed water, or if there is a
capacity problem at the Encina Water Pollution Control
Facility that requires it to operate. For the purposes of
estimating costs for the needed improvements to this plant,
facilities required to allow this plant to operate as a
reclamation plant are included. Although the plant has a
design capacity of 1.2 million gallons per day, the maximum
flow which can be conveyed to the plant is 0.88 million
gallons per day.
Improvements to the Lake Calavera Hills Water Reclamation
Plant. There are four major improvements which are needed
for the Lake Calavera Hills Water Reclamation Plant to
operate as a reclamation plant. The costs for these
improvements are shown in Table 7-7. The biggest expense
would be the construction of missing portions of the
63
effluent disposal line to convey treated effluent from the
Lake Calavera Hills Water Reclamation Plant to the Encina
Outfall. This improvement would be needed to operate the
plant, either as a reclamation plant or as a treatment
plant.
Table 7-7. Improvements to the Lake Calavera Hills
Water Reclamation Plant
Item Cost,
dollars
Completion of Effluent Disposal Line
(Lake Calavera Hills Water Reclamation
Plant to El Camino Real at
College Boulevard)
1,272,000
Solids Disposal Line 293,000
Lift Station Improvements
(El Camino Real at Tamarack
Avenue)
40,000
Tertiary Facilities 1,028,000
TOTAL 2,633,000
To allow for the efficient operation and maintenance of the
Lake Calavera Hills Water Reclamation Plant, a solids
disposal line should be installed, and the lift station at
the corner of El Camino Real and Tamarack Avenue should be
improved.
The final improvement to the Lake Calavera Hills Water
Reclamation Plant would be the addition of tertiary
facilities for water reclamation. These facilities would
not be needed if the plant was operated as a treatment plant
with effluent disposal through the Encina Ocean Outfall.
These improvements are discussed in more detail in Appendix
D. Improvements to the Lake Calavera Hills Water
Reclamation Plant should begin two years prior to the
estimated need for the facility.
64
CHAPTER 8
REVENUE PROGRAM REQUIREMENTS
To assure the proper operation of a sewerage enterprise
fund, the amount of money taken in must be equal to the
amount of money spent. This chapter develops the connection
fees needed to fund the improvements to the sewerage
facilities.
USE OF FUNDS
To assure the continued fiscal solvency of the sewer
enterprise fund, the use of various sources of revenue to
the fund should be restricted. The purpose of these
restrictions is to prevent the fund from going bankrupt when
growth within the agency ceases. To comply with the
guidelines, all sewerage system operations, maintenance and
capital replacement costs should be recovered from service
charges. Capacity fees should be used to pay only capital
costs.
Sewer Service Charges
Sewer service charges are monthly fees paid by the user for
the privilege of using the sewage disposal system. They may
be used for any of the district's expenses but they should
cover the costs of operation, maintenance and capital
replacement. The sewer service charge is to be based on
both the quantity and strength of the sewage produced.
Strength is normally only a major factor for industrial
users. Sewer service charges are not analyzed in this
report.
Capacity Fees
Capacity fees are charged to new users who connect to the
system. They are based on the estimated quantity of the
discharge and are routinely charged to residential,
commercial and industrial builders. These fees are intended
to pay for the approximate capital expense for the portion
of system used.
65
CAPACITY FEE
Based on the capital projects presented in Chapter 7 and
estimated costs for a monitoring program and City
Maintenance Facility, Table 8-1 projects the capital costs
for the listed time periods. The cost per equivalent
dwelling unit is $1,247.
Table 8-1. Connection Fees
Item Costs, thousands of dollars
1987-1989 1990-1994 1995-1999 Beyond 2000 Total
Encina Water Pollution
Control Facility
Improvements
11,108 12,492 11,775 0 35,375
Lake Calavera Hills
Water Reclamation Plant
0 0 0 2,633 2,633
Interceptor System 1.270 0 2,068 1,472 4,810
Lift Stations 945 871 2, 100 1,292 5,208
City Maintenance
Facility
0 0 500 0 500
Monitoring Program 60 100 100 340 600
Total 13,383 13,463 16,543 5,737 49,126
Increase in EDUs, units 4,125 5,680 5,690 23,885 39,380
The City of Carlsbad funds only improvements to the Encina
Water Pollution Control Facility, the Lake Calavera Hills
Water Reclamation Plant, designated interceptors, lift
stations, maintenance facilities and the growth management
monitoring program through the connection fee process. All
improvements to trunk and collector sewers, are funded
through the development process.
66
CHAPTER 9
RECLAMATION PROGRAM
There are a number of reclaimed water lines within the City
of Carlsbad. These water lines are currently used as
effluent disposal lines from the Gafner Water Reclamation
Plant, the Meadowlark Water Reclamation Plant and the Shadow
Ridge Water Reclamation Plant. Plans have also been
developed to complete the effluent disposal line from the
Lake Calavera Hills Water Reclamation Plant to the existing
line near Palomar Airport Road. This chapter will discuss
the issues involved in water reclamation and then discuss
the existing and proposed facilities within the City of
Carlsbad.
WATER RECLAMATION ISSUES
To fully understand the water reclamation potential within
the City of Carlsbad, a number of issues must be raised and
discussed. These issues relate to the cost, distribution
and use of reclaimed water.
Cost
There are two elements associated with the cost of using
reclaimed water. The first is the cost to purchase the
reclaimed water; the second is the cost of the reclaimed
water distribution system. In order to have a viable market
for reclaimed water, the total price for the reclaimed
water, including capitalization of improvements, must be
less than the cost for potable water. Since the potable
water system is in place within the City of Carlsbad, a
substantial capital investment difference exists between
utilization of potable water versus reclaimed water.
Cost of Reclaimed Water. For a user to utilize reclaimed
water instead of potable water, it must be financially
beneficial for him. If conveyance systems are in place for
the user to pick whether he utilizes reclaimed water or
potable water, there is still an added cost to the user
associated with reclaimed water. For example, if a golf
course chooses to use reclaimed water rather than potable
water for irrigation, they must post the golf course and
will probably be required to print on their scorecards that
reclaimed water is being used on the site. They will also
have to designate a person on their staff to be responsible
for use or misuse of the reclaimed water. The golf course
will further have to investigate all of their piping systems
67
to assure that there are no existing or potential interties
between potable systems and reclaimed water systems. This
means that all restrooms and drinking fountains located on
the golf course will have to be reviewed to assure that
there is no possible way to cross tie the two water systems.
All drinking fountains located outdoors where they could be
sprayed by the irrigation system would have to be moved.
For an existing golf course, the expense associated with
relocation of bathroom facilities may be greater than the
savings associated with the use of the reclaimed water and
the potential user will elect not to use the reclaimed
water. Thus, the simple statement that the reclaimed water
is 75 percent of the cost of potable water does not make it
cost effective to the ultimate user.
Capital Costs. In ord er for users to use reclaimed water-
it must be made available to them. In most cases, reclaimed
water lines are not adjacent to potential users. This is
not the case for potable water. Potable water lines are put
in with all developments and will continue to be put in as
the primary source of water. Small users are not able to
install reclaimed water lines to bring the water to their
project. It is not cost effective for them to construct
these lines for the nominal savings in their water bills. A
user must be a substantial water user in order for the
savings to offset the capital construction .costs.
REGULATIONS
There are two agencies which regulate the use of reclaimed
water. These agencies are the State Health Department and
the Regional Water Quality Control Board. Like all other
agencies, these agencies' rules and requirements for the use
of reclaimed water change over time. Historically, the
rules have gotten more and more restrictive for the use of
reclaimed water. Thus, the cost for the use of reclaimed
water has increased. It is likely that this increase will
continue over time and that the regulation concerning the
use of reclaimed water will become more and more
restrictive.
Regional Water Quality Control Board
The Regional Water Quality Control Board sets the treatment
and monitoring standards for wastewater reclamation plants.
The Regional Water Quality Control Board also reviews the
reclaimed water purveyors rules and regulations and issues
permits for reclaimed water users.
68
State Health Department
The State Health Department sets the levels of treatment
required for individual users of reclaimed water. These
regulation fall under Title 22 of the Administrative Code of
the State of California. Title 22 establishes the treatment
level requirements and chlorination requirements based on
certain categories of users.
EXISTING RECLAIMED WATER FACILITIES
There are a number of facilities which have been constructed
within the City of Carlsbad in conjuction with water
reclamation plants. These facilities could be utilized to
provide water to potential users. Figure 9-1 shows these
existing facilities.
Conveyance System
All satellite reclamation plants have a connection to the
Encina Ocean Outfall. The lines connecting the satellite
plants with the ocean outfall run through the City of
Carlsbad and could be utilized as a reclaimed water
distribution system. The major line running through the
City of Carlsbad connects to the Meadowlark Treatment Plant
and the Shadow Ridge Treatment Plant. It will eventually
connect to the Lake Calavera Hills Water Reclamation Plant.
This line runs parallel to Palomar Airport Road up to
College Boulevard. At College Boulevard there is a branch
which follows College Boulevard to El Camino Real. This
branch will eventually serve the Lake Calavera Hills Water
Reclamation Plant. The main line continues to follow
Palomar Airport Road to the Palomar Airport Business Park.
At this point it branches with one line heading out toward
the intersection of El Camino Real and Palomar Airport Road
and eventually to the Shadow Ridge Treatment Plant while the
other branch crosses El Camino Real and goes down into the
Carillo Ranch area to the Meadowlark Treatment Plant. There
is also an excess effluent disposal line which runs from the
Gafner Treatment Plant along La Costa Avenue and then up the
coast to the Encina Water Pollution Control Facility. All
of these lines can be operated as pressure pipelines to a
certain degree. It is anticipated that these lines would
serve as the backbone for any reclaimed water distribution
system.
69
Water Reclamation Plants
There are four water reclamation plants which could be
utilized to produce reclaimed water. The four water
reclamation plants are the Lake Calavera Hills Water
Reclamation Plant, the Meadowlark Water Reclamation Plant,
the Shadow Ridge Water Reclamation Plant and the Gafner
Water Reclamation Plant. Each of these plants is discussed
below.
The Lake Calavera Hills Water Reclamation Plant. The Lake
Calavera Hills Water Reclamation Plant can produce 1.2 mgd
of secondary quality effluent. However, without major
modifications to the existing conveyance system, a maximum
flow of 0.88 million gallons per day is all that can reach
the Lake Calavera Hills Water Reclamation Plant. Thus, the
maximum water available for reclamation at this plant with
the facilities recommended in this report is 0.88 million
gallons per day. In order to utilize this plant as a
reclamation facility, $2,633,000 of improvements would be
required. These improvements are discussed in Chapter 7. A
detailed discussion of the Lake Calavera Hills Water
Reclamation Plant can be found in Appendix D.
Meadowlark Water Reclamation Plant. The Meadowlark Water
Reclamation Plant is capable of producing 2.0 million
gallons per day of tertiary treated water. Water from this
plant is currently being delivered to the La Costa Golf
Course for irrigation purposes.
Shadow Ridge Water Reclamation Plant. The Shadow Ridge
Water Reclamation Plant is currently capable of producing
1.0 million gallons per day of filtered chlorinated
wastewater. This plant is currently under operation and
discharging flows down the fail-safe line.
Gafner Water Reclamation Plant. The Gafner Water
Reclamation Plant can produce 0.75 million gallons per day
of secondary effluent.
FACILITIES
Figure 9-1 shows existing and proposed facilities for
reclaimed water distribution. The figure also shows the
location of the major potential reclaimed water users.
Parkway irrigation users are not shown on this figure. This
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STUDY AREA
RANCHO CARLSBAD
GOLF COURSE
POTENTIAL
GOLF COURSE
ENCINA
WATER
POLLUTION
CONTROL
FACILITY
POTENTIAL
GOLF COURSE
EXISTING RECLAIMED WATER LINE
FUTURE RECLAIMED WATER LINE
FIGURE 9-1
RECLAIMED WATER LINES AND
POTENTIAL USE AREAS
71
is because parkway irrigation would require the use of a
dual piping system, and dual piping systems are not cost
effective.
SUMMARY
In order to summarize the issues and policies related to the
use of reclaimed water, it is best to discuss current
reclaimed water users. At the present time the La Costa
Golf Course is the only user within the City of Carlsbad
which is actively pursuing the use of reclaimed water. The
nine hole extension of their golf course north of Alga Road
is able to utilize reclaimed water from the Meadowlark Water
Reclamation Plant. This project was able to allow for the
use of reclaimed water on their golf course because the
excess effluent disposal line from the Meadowlark Water
Reclamation Plant was adjacent to the golf course and the
irrigation system on the golf course was set up as a
non-potable system. Since the irrigation system was
non-potable, the reclaimed water could be tied directly into
the irrigation system. Although the nine holes are set up
so they can be irrigated with reclaimed water, the golf
course has used the reclaimed water sparingly, due to the
high total dissolved solids and the problems these salts
cause to the turf.
Based on the results at the La Costa Golf Course, the
viability of reclaimed water use, even on model projects, is
marginal. Projects which would require substantial capital
outlay at this time would be prohibitively expensive.
Therefore, a regional approach to water reclamation which
provides flexibility for the future is the proper path at
the present time. This regional approach should incorporate
the Encina Water Pollution Control Facility as the regional
sewage treatment plant and allow the reclamation program to
be built around the existing satellite reclamation plants.
Since facilities are now in place to produce reclaimed water
and a network of distribution lines could be set up using
the existing effluent disposal lines, no additional
facilities should be constructed until a strong user base is
established for the reclaimed water.
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LIST OF REFERENCES •
Algren & Koptionak, Inc. Report on South Agua Hedionda
Interceptor for City of Carlsbad. September, 1987.
John Carollo Eng ineers, Encina Water Pollution Control
Facility 2020 Facility Plan. Draft, August, 1987.
John Carollo Engineers, Encina Water Pollution Control
Facility Ocean Outfall Facility Plan. August, 1985.
Encina Water Pollution Control Facility, Budget
Recommendations 1987/88 Fiscal Year. June, 1987.
Eraser, Wilson & Associates, Master Plan of Sewerage. Vista
Sanitation District. Buena Sanitation District. March, 1982.
Neste, Brudin & Stone Incorporated, Sewer Master Plan City
of Carlsbad. June, 1984.
Wilson Engineering, Evaluation of the Capacity of the Buena
Interceptor in the City of Carlsbad. April, 1987.
Wilson Engineering, Facilities Plan for Agua Hedionda Pump
Station and Buena Vista Pump Station. October, 1987.
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