SP22-0003_Staff Report_Attach B4_Appx L_Water and Sewer Study — San Marcos City Council, October 24, 2023

V ALLECITOS WATER DISTRICT
CALIFORNIA PACIFIC HOMES &AOA SAN MARCOS LLC.MIXED USE WATER AND

SEWER STUDY
WORK ORDER # 267553

FINAL T ECHNICAL MEMOR ANDUM
May 16, 2023
Prepared By: Elizabeth Lopez, Senior Engineer Development Services , and Lisa Whitesell Engineering Technician ill

INTRODUCTION
The proposed California Pacific Homes project (Project) is a 102-unit multi-family residential development and AOA San Marcos LLC is the mixed use development with 7,536 square feet of Office Space, 42,434 square feet of commercial space consisting of Restaurant Space, Retail Space, Brewery and Distille1y, and 8 - Live/Work Units on a grand total of 10.91-acres , located on the southwest comer of Grand Avenue and Linda Vista Drive (APN 's 219-152-42 , 44, 45, 51 , 61 , 70, 75, 76, 78, 79 and portions of 74).

The Project is located within Vallecitos Water Dish·ict's (VWD) boundaries for water and wastewater service. The prope11y does not need to annex, both water and wastewater services can be provided by VWD .

All new projects undergo evaluation by VWD to detennine if the current water and sewer infrastmcture is sufficient to accommodate the proposed water demands and sewage generation.

This study projects water demand and sewage generation increases due to the project densification .

It analyzes the following aspects of VWD 's infrastmcture and makes recommendations for capital improvements for impacts that are created due to the land use change:
Water distribution system, including the need to upsize pipelines , install new pipelines , or install flow control facilities .
Water storage , including the need for additional storage and the adequacy of existing storage tanks and reservoirs to serve the proposed development. Water pump stations , including the need to install new pump stations or upsize existing pump stations to serve the proposed development.
Wastewater collection system , including the need to upsize pipelines and manholes , or the need to install new pipelines and manholes.
Wastewater lift stations , including the need to install new lift stations or upsize existing lift stations to serve the proposed development.

California Pac ific Hom es & AOA San Marcos LLC. Mixed Use Water and Sewer Study FINAL Technical Memorandum
April 26, 2023

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Wastewater land outfall , including the need to constrnct a parallel land outfall to serve this and other proposed developments.
Wastewater treatment facilities , including the need for obtaining additional capacity at the Encina Water Pollution Control Facility (EWPCF) or for expanding the Meadowlark Water Reclamation Facility (MRF) .
Existing VWD water and/or sewer facilities not being utilized for proposed development will need to be abandoned per VWD Standards and Specifications. Asbestos cement pipe shall be properly removed and legally disposed of by the Developer.

WATER SYSTEM ANALYSIS
The proposed 10.91-acre Project lies completely within VWD's 855 Pressure Zone. Figures I and 2 show the development's location in relation to pressure zone boundaries , identify pipelines within the vicinity of the development , and identify storage reservoirs that supply the development area.

Water Demand Pr0jections
The City of San Marcos' approved land use designation for the proposed Project is Business Industrial (I/C) and Commercial (C). The 2018 Master Plan based its ultimate water demand planning on Industiial. Table l provides the average water demand generated both under the density planned for the 20 18 Master Plan and for the proposed Project. The table shows California Pacific Homes & AOA Mixed-Use Project will increase the projected average water demand from the 2018 Master Plan land use by 28,967 gallons per day.

Table 1 - Project Estimated Water Demands for California Pacific Homes & AOA Mixed-Use Land Use Type Area Residential Duty Factor Water Demand acres Units d/ac d
2018 Master Plan Land Use Demand
Industrial 10.91 800 8,728
Total 10.91 8,728
Proposed Project Demand
Residential (20-30 du/ac) 4.74 110 6,000 28,440
Commercial/Mixed use/Office 6.17 1,500 9,255
Total 10.91 37,695
Water Demand Increase 28,967
\
Legend:
~ 920 Zone PRV
• Storage Tank
Affected Pipeline
2" Diameter Pipeline
4" Diameter Pipeline
6" Diameter Pipeline
8" Diameter Pipeline
1 O" Diameter Pipeline
12" Diameter Pipeline
16" Diameter Pipeline
18" Diameter Pipeline
1- 20" Diameter Pipeline
- 24" Diameter Pipeline
27" Diameter Pipeline
30" Diameter Pipeline
- 36" Diameter Pipeline
42" Diameter Pipeline
1- Unaffected Pipeline
- Proposed Project
-- Unaffected Pressure Zones
Twin Oaks 1028
Richland 920
855 Zone
fl!:
~
Twin Oaks I ~ in Oaks II

33.00 MG Tank ~ 40.00 MG Tank
L ___ _J ____ 7 Feet N
.. -,_ ·~ ... i
California Pacific Homes &
AOA Mixed Use W & S Study
Existing Water Facilities in
Study Area
April 2023
Figure 1
E:IDE_~LOPM~J SERVIO1;'5·1fil<OJE.'.CIS\ll)'O 265000 • 269999 Projects\WO 261553 - AOS Marcos Call Pacific l,lomes WS Study\Figures\MarcosC\!lifornia Paclfie Hq_mes mixed use WS Study Fig 1.mxd Legend:

Affected Pipeline
- 4" Diameter Pipeline
- 6" Diameter Pipeline
- 8" Diameter Pipeline
- 10" Diameter Pipeline
- 12" Diameter Pipeline
- 14" Diameter Pipeline
- 18" Diameter Pipeline
- 24" Diameter Pipeline
- 27" Diameter Pipeline

PROJECT SITE
855 Grade Line
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\..\~OP-\J\5' fl- o?-
~ L ____ ,r.;;;...-----, Feet N
120 240 480 720
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Vallecitos Water District
California Pacific Homes &
AOA Mixed Use W & S Stud
Existing Water Facilities in
Study Area
April 2023
Figure 2
California Pacific Homes & AOA San Marcos LLC. Mixed Use Water and Sewer Study FINAL Technical Memorandum
April 26, 2023

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Water Distribution System Analysis
The 2018 Master Plan water system distribution and pressure criteria are as follows:

Water Distribution In(i-astructure Criteria
The water service pressure criteria to be met by this development are as follows :
Minimum allowable pressure at peak hour demand: 40 psi Minimum allowable pressure at max day plus fire demand: 20 psi Maximum allowable pressure: 150 psi
The City of San Marcos Fire Marshall has set the required fire demand at 1,875 gpm (West End Residential Townhomes) & 1,688 gpm (East End - Commercial/Mixed Use) for the Project.

To avoid excessive velocity and headloss within the distribution system , the following pipeline design criteria was also utilized:
Maximum allowab le velocity: 7 feet per second
Maximum allowable headloss gradient:
Hazen-Williams C-factor:

Water Model Scenarios
15 feet per 1,000 feet
130
The following scenarios were modeled to identify system impacts that may be created by the proposed water demands , and to recommend any improvements required to provide service to the Project:
Average Day Demand with existing demands at the Project site Average Day Demand with the proposed Project
Maximum Day Demand with existing demands at the Project site Maximum Day Demand with the proposed Project
Peak Hour Demand with existing demands at the Project site Peak Hour Demand with the proposed Project
Maximum Day Demand plus Fire Flow with existing demands at the Project site Maximum Day Demand plus Fire Flow with the proposed Project Per the 2018 Master Plan, maximum day demands for this project are 300% those of average day demands, and peak hour demands are 620% those of average day demands .

Water Model Results
Modeling focused on the infrastructure in the direct vicinity of the Project. The model found that the Project did not create any distribution system deficiencies under average day demand or under maximum day plus fire flow demand conditions.

Ca liforn ia Pacific Homes & AOA San Marco s LLC . Mixed Use Water and Sewer Study FINAL Technic al Memorandum
Apri l 26, 2023

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Table 2 & 2A presents a summary of the modeling results for this analysis includin g proposed off site pipelines , shown in Figure 2.

Table 2 - Potable Water Pipeline Results under Maximum Day Demand plus Fire Flow Conditions @ 1,875 gpm for Residential
Velocity Velocity Existing under under Upsized Velocity under Pipe ID Length Pipe Average Maximum Pipe Maximum Day +
Number (ft) Diameter Day Day+ Fire Diameter Fire Flow w/ (in) Demand (in) Upsized Pipe (ft/s)
(ft/s) Flow (ft/s)
MC-1 1,086 10 1.77 3.15 - -
MC-2 481 10 1.77 4.61 - -
MC-3 359 10 0.79 3.73 - -
MC-4 424 10 0.79 3.81 - -
MC-5 172 8 4.00 4.13 - -
Table 2A- Potable Water Pipeline Results under Maximum Day Demand plus Fire Flow Conditions @ 1,688 gpm for Commercial
Velocity Velocity Velodty under Existing under under Upsized Maximum Day + Pipe ID Length Pipe Average Maximum Pipe Fire Floww/ Number (ft) Diameter Day Day+ Fire Diameter Upsized Pipe (in) Demand Flow (ft/s) (in) (ft/s) (ft/s) MC-1 1,086 10 1.77 1.29 - -
MC-2 481 10 1.77 1.09 - -
MC-3 359 10 0.79 3.40 - -
MC-4 424 10 0.79 3.54 - -
MC-5 172 8 4.00 3.65 - -
Californ ia Paci tic Homes & AOA San Marcos LLC. Mixed Use Water and Sewer Study FINAL Technical Memorandum
April 26, 2023

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Waterr Starage Anall)?sis
The 2018 Master Plan outlines VWD's potable water storage reservoirs for each pressure zone as follows:

1.5 times ADD (operational storage) + 3.0 times ADD (emergency storage) + fire flow demand= 4.5 times ADD + fire flow demand
OR

5.0 times ADD, whichever is greater.

The Project is located entirely within the VWD 855 pressure zone. Water storage for this zone is located within the 920 zone and 1028 Twin Oaks pressure zones , as shown in Figure 1. Table 3 shows the required storage in the 855, 920, and 1028 Twin Oaks pressure zones for existing and ultimate build-out (Master Plan) conditions relative to the existing storage provided within each zone.

Table 3 - Existing Reservoir Storage Capacity and Requirements Existing Ultimate Existing
Existing Storage Ultimate Storage Storage
ADD Requirement ADD Requirement Available
Pressure Zone (MGD) (MG) (MGD) (MG) (MG)
855 3.74 6.79 0
920 5.61 50.05 10.40 101.25 18
1028 Twin Oaks 0.66 3.06 73
Totals 10.01 50.05 20.25 101.25 91
The Project will increase the projected average water demand by approximately 28,967 gallons per day as shown in Table 1.

The amount of additional reservoir storage required is 500% of the development' s average day demand or:
28,967 gallons * 500% = 144,835 gallons
The analysis finds that water storage capacity is currently available to serve the Project 's increased storage requirements. Master Plan projects address and accommodate the ultimate build-out storage deficiency and Water Capital Facility Fees paid by this project will be used for the increase in storage necessitated by the Project 's demand calculated above.

Wa,ter Pump; Station Analysis
Since the proposed Project is located in a pressure zone that is not served by pumping , there are no impacts to existing or proposed pump stations by this Project.

Cali fornia Pacific Homes & AOA San Marcos LLC. Mixed Use Water and Sewer Study FINAL Technical Memora ndum
April 26, 2023

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WASTEWATER SYST EM ANALYSIS
The proposed 10.91-acre Project lies completely within VWD sewer shed 22C. Figures 3 through 5 show the development's location in relation to sewer shed boundaries , identify wastewater infrastrncture within the vicinity of the development , and identify the downstream collection infrastrncture that will be impacted by the development.

Wastewater Flow Projections
The Project property 's City of San Marcos approved land use designation for the proposed Project is Business Industrial (I/C) and Commercial (C). The 2018 Master Plan based its ultimate wastewater generation planning on Industrial. Table 4 provides the average wast ewater flow generated both under the density planned for the 2018 Master Plan and with the proposed Project.

The table shows California Pacific Homes & AOA Mixed-Use project will increase the projected average wastewater generation from the 2018 Master Plan land use by 21,097 gallons per day.

Table 4 - Project Estimated Wastewater Flows for California Pacific Homes & AOA Mixed-Use Project Land Use Type Area Residential Duty Factor Wastewater Flow (gpd) acres Units d/ac 2018 Master Plan Land Use Flows
Industrial 10.91 700 7,637
Total 10.91 7,637
Proposed Project Demand
Residential {20-30 du/ac~ 4.74 110 4,500 21 ,330
Commercial/Mixed Use 6.17 1,200 7,404
Total 10.91 28,734
Sewer Generation Increase 21,097
Legend
Affected gravity mains
- 8" Diameter Pipeline
- 10" Diameter Pipeline
- 15" Diameter Pipeline
- 15" Diameter Pipeline
21" Diameter Pipeline
- 30" Diameter Pipeline
- 42" Diameter Pipeline
- Unaffected Pipeline
D Sewer Shed 22C
D Sewer Shed 30C
Proposed Project
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0 295 590
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0 1,180
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Vallecitos Water District
California Pacific Homes &
AOA Mixed Use W & S Study
\
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Existing Sewer Facilities in
Study Area
April 2023
Figure 3
,~.iii· '11111. ·, P9clfic: Homfl!. m,~, • ,se \/1.'S S:...dv Fia 3.m,a Legend
Affected gravity mains
- 8" Diameter Pipeline
- 15" Diameter Pipeline
21" Diameter Pipeline
- 30" Diameter Pipeline
- 42" Diameter Pipeline
- Unaffected Pipeline
D Sewer Shed 22C
D Sewer Shed 30C
Proposed Project
a·o·e
~
21·e =
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160 320
-----
r
640
l Feet
960
N
i
___...--- ---
Vallecitos Water District
California Pacific Homes & AOA
Mixed Use W & S Study
Existing Sewer Facilities in
Study Area
April 2023
Legend
Affected gravity mains
- 8" Diameter Pipeline
- 1 O" Diameter Pipeline
- 15" Diameter Pipeline
- 15" Diameter Pipeline
- 21" Diameter Pipeline
- 30" Diameter Pipeline
- 42" Diameter Pipeline
- Unaffected Pipeline
LJ Sewer Shed 22C
LJ Sewer Shed 30C
Proposed Project
29~0 ~
N
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~
0 160 320
\
\
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I
640
.......
l Feet
960
MRC-15
MRC-19
t 'so
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t
23~0 ~
~1:§
Vallecitos Water District
California Pacific Homes &
AOA Mixed Use W & S Study
Existing Sewer Facilities in
Study Area
April 2023
California Pacific Homes & AOA San Marcos LLC. Mixed Use Water and Sewer Study FINAL Technical Memorandum
April 26, 2023

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Wastewater Collection System Analysis
The 2018 Master Plan outlines VWD's wastewater system design criteria which are as follows:

Wastewater Collection infrastructure Criteria
The wastewater pipeline criteria to be met both within and downstream of the development are as follows :
Pipes 12 inches in diameter and smaller: ½ full maximum at peak flow Pipes over 12 inches in diameter: ¾ full maximum at peak flow Minimum velocity: 2 feet per second
Maximum velocity: 10 feet per second
Manning's n for gravity pipes: .013
Hazen-Williams C-factor for force mains/siphons: 120
Slope for pipes 8 inches in diameter and smaller: 0.4% minimum Slope for pipes over 8 inches in diameter: to be determined by VWD When flow depth in gravity pipes exceeds maximum levels as stated above, a pipe upsize will be specified.

Wastewater Model Scenarios
The following scenarios were modeled to identify system impacts that may be created by the proposed sewer generation , and to recommend any improvements required to provide service to the Project:
Average Dry Weather Flow with existing flows at the Project site Average Dry Weather Flow with the proposed Project
Peak Dry Weather Flow with existing flows at the Project site Peak Dry Weather Flow with the proposed Project
Peak Wet Weather Flow with existing flows at the Project site Peak Wet Weather Flow with the proposed Project
The peak dry weather curve is:

Peak Dry Weather Factor= 2.16 x (Average Dry Weather Flow Ratet 0·1618 The wet weather peak curve is:

Peak Wet Weather Factor= 2.78 x (Average Dry Weather Flow Ratey 0-087 California Pacific Homes & AOA San Marcos LLC. Mixed Use Water and Sewer Study FINAL Technical Memorandum
April 26, 2023

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Wastewater Model Results
Modeling focused not only on the sewer collection infrastructure in the direct vicinity of the Project , but also on all downstream infrastructure from the development to Lift Station No. l on San Marcos Boulevard that would be impacted by the proposed Project flows (see Figures 3 - 5).

Table 5 presents a summary of the modeling results from this analysis. The modeling results showed that no deficiencies were identified under the curTently approved density under peak wet weather flows during ultimate build-out conditions .

California Pacific Homes & AOA Mixed-Use Water and Sewer Study FINAL Technical Memorandum
May 16, 2023

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Table 5 -California Pacific & AOA Wastewater Model Results and Recommended Gravity Main Improvements Wastewater Flows with Existing Density Wastewater Flows with Proposed Density PWWF Replacement PWWF Replacement
Pipe ID Length Diameter Peak Wet Depth-to- Replacement PWWF Peak Wet Depth-to- Replaceme PWWF Depth-Slope Weather Depth-to- Weather nt Diameter Number (ft) (in) Flow (gpm) Diamter Diamater (in) Diamater Flow (gpm) Diamter (In) to-Dia mater Ratio Ratio Ratio Ratio
MR-1 241 15 0.003 662 0.46 709 0.47
~
'I .JL-
- _.. -..->I - - .. !;----,._
MR-2 187 15 0.004 668 0.42 - ,_..,._:~:Z 715 0.44 - - , MR-3 135 15 0.006 670 0.38 - ~~~ 717 0.39 - -- -
MR-4 355 15 0.005 672 0.40 - .. 1-i,-.:-:.a.i 719 0.41 - MR-5 254 15 0.005 674 0.40 -: ~ ' 721 0.41 ~;' -- r:::::::::1- [ MR-6 32 15 0.007 676 0.37 ~ 723 0.38 --. .. _ ~-~ _ , .. 'r,. - . . J_ : 1_ MR-7 345 15 0.004 678 0.43 .. le7-~ 725 0.44
-- ___ ..lf
:-'~ - . I ~ ~
MR-8 341 15 0.004 680 0.43 ' =,~ 727 0.44 - ..... ~
·-· ~ ....:....--n. - ~ r ~
MR-9 345 15 0.004 682 0.43 - - l i 729 0.44 :t !lri: - ......... - ...... ' - MR-10 346 15 0.004 685 0.43 - -= 732 0.44 ~~- - ~ I -•~ MR-11 149 15 0.005 687 0.40
~
~~ 734 0.42 l.~-
I .. =i~ - !\ ~-.-J ~
MR-12 78 15 0.010 689 0.34 - ~ -'t,_: 736 0.35 ..
- •: ~l C • - . :-: _
MR-13 8 15 0.055 689 0.22 ~ 736 0.23 -- ~ ~
- ..-~ . ---~
MR-14A 13 18 0.008 2,885.00 0.61 - ~le 2,932 0.62
~
'.;;p - , - - ':..! ~
MR-14B 385 21 0.005 3,401.00 0.61 ~- ri"._ .·: 3,448 0.61 - •~ I MR-14C 312 21 0.003 3,406.00 0.73 3,453 0.74
T
- - - I - ~
MR-14D 380 21 0.005 3,410.00 0.61 3,457 0.61
,-. . .-- - - -- -r
PIPE SEGMENTS MR-1 THROUGH MR-14D ARE THE FLOWS FROM THE RESIDENTIAL SIDE OF PROJECT PROPOSED DENSITY RESIDENTIAf 47 !GPM
California Pacific Homes & AOA Mixed-Use Water and Sewer Study FINAL Technical Memorandum
May 16, 2023

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MC-10 475 8 0.005 121 0.39 ~~ 126 0.40 --: _ .. - --,:-r . .1. ·- ~~-' MC-11 256 10 0.004 248 0.44 f-:!=N 253 0.40
,;,--
; ~~1~ - , .. -
MC-12 417 10 0.004 250 0.45 - ~':-·;L·~ 255 0.45 ,~ . - - ~----MC-13 403 10 0.004 252 0.45 - • ....,. ~. ~ 257 0.45 . -.-- . - ~. ,- .- , ... ------~- MC-14 10 10 0.06 255 0.22 - - 260 0.23 - -
PIPE SEGMENTS MC-1 THROUGH MC-14 ARE THE FLOWS FROM THE MIXED-USE SIDE OF PROJECT PROPOSED DENSITY MIXED-USE: I 6 !GPM
California Pacific Homes & AOA Mixed-Use Water and Sewer Study FINAL Technical Memorandum
May 16, 2023

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Table 5 -California Pacific & AOA Wastewater Model Results and Recommended Gravity Main Improvements Wastewater Flows with Existing Density Wastewater Flows with Proposed Density PWWF Replacement PWWF Replacement
Pipe ID Length Diameter Peak Wet Depth-to- Replacement PWWF Peak Wet Depth-to- Replaceme PWWF Depth-Slope Weather Depth-to- Weather nt Diameter Number (ft) (in) Flow (gpm) Diamter Diamater (in) Diamater Flow (gpm) Diamter (In) to-Diamater Ratio Ratio Ratio Ratio
MRC-15 33 21 0.018 6978 0.64 - - 7,031 0.64 - -
MRC-16 297 21 0.005 3680 0.64
u
3,733 0.65 -
I 1:
- -~ - - .. - - ~ ~
MRC-17 295 21 0.006 3682 0.60 ~ - 3,735 0.61 --
~
- I • -
- - -
MRC-18 112 21 0.014 3687 0.47 ... r:~ 3,740 0.47 -~ - L,. _____....._.. __ - - MRC-19 15 30 0.047 4182 0.22 ?""" i":.'li:i 4,235 0.22
.. - ,c
·- ,I - - - I,
MRC-20 25 42 0.013 13934 0.36 - ~.a;:; q- 13,987 0.36
. T
-- - -C - ~ -
MRC-21 75 42 0.002 13934 0.62 - ~-· =· - 13,987 0.62 - - MRC-22 347 42 0.002 13943 0.62 - ;:'r,. -----;:-'-._ 13,996 0.62 - - MRC-23 18 42 0.003 13945 0.54 - - 13,998 0.54 ·--, -
MRC-24 10 42 0.034 13946 0.28 - - 13,999 0.28 - --
MRC-25 10 42 0.010 14139 0.39 - - 14,192 0.39 - -
-MRC-26 73 42 0.004 14712 0.51 - - 14,765 0.52 - - ,
PIPE SEGMENTS MRC-15 THROUGH MRC-26 ARE THE FLOWS FROM THE ENTIRE PROJECT BOTH RESIDENTIAL & MIXED-USE PROPOSED DENSITY RESIDENTIAL & MIXED-USE: I 53 !GPM
California Pacific Homes & AOA San Marcos LLC. Mixed Use Water and Sewe r Stud y FINAL Technical Memorandum
April 26, 2023

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Wastewater Lift Station Amtlysis
Lift stations are sized for peak wet weather flow with manufacturer 's recommended cycling times for pumping equipment. Since the proposed Project is not located in a sewer shed that is served by a lift station , there are no lift station upgrade requirements for this project.

Parallel Land Outfall Analysis
VWD 's existing land outfall is shown in Figure 6. The outfall is approximately 8 miles in length and consists of 4 gravity pipeline sections and 3 siphon sections varying in diameter from 20 inches to 54 inches. VWD maintain s the entire pipeline from Lift Station No. 1 to the Encina Water Pollution Control Facility (EWPCF). From Lift Station No. 1 to El Camino Real, VWD is the sole user of this pipeline. From El Camino Real to the EWPCF , the ownership capacity is as shown in Table 6 below:

Table 6 - Land Outfall Capacity Ownership by Agency
Agency Ownership Capacity
Percentage (MGD)
Carlsbad 23.98% 5.00
Vista 17.99% 3.75
VWD 58.03% 12.10
Totals 100.00% 20.85
. .

The Meadowlark Water Reclamation Facility (MRF) has a capacity of 5.0 MGD with a peak wet weather capacity of 8.0 MGD. Therefore , VWD has a combined peak wet weather wastewater collection capacity of 20.10 MGD (12.10 MGD + 8.0 MGD).

VWD's 2014 average daily wastewater flow through the land outfall was 7.5 MGD. This corresponds to a peak wet weather flow of 17.5 MGD, which falls within VWD 's combined peak wet weather collection capacity .

The 2018 Master Plan estimated that, under approved land uses, VWD has an ultimate build-out average dry weather flow of 14.4 MGD. This con-esponds to a peak wet weather flow of 31.7 MGD, which exceeds VWD 's combined peak wet weather collection capacity. To accommodate additional wastewater flows from planned development , the 2018 Master Plan recommended conveyance of peak flows to the EWPCF through a parallel land outfall.

The Project proposes to generate 21,097 gallons per day of additional average wastewater flow that was not accounted for in the Land Outfall's capacity studied in the 2018 Master Plan.

The analysis finds that outfall capacity is currently available to serve the Project 's proposed wastewater generation. Wastewater Capital Facility Fees paid by this Project will be used toward design and construction of a parallel land outfall to be sized to accommod ate ultimate build-out wastewater flows .

Legend
- Outfall - Gravity Mains A r- Sewershed 21 C
- Outfall - Siphon A L Sewershed 22C
- Outfall - Gravity Mains B
-
Sewershed 27C
- Outfall Siphon B C Sewershed 28C
Outfall - Gravity Mains C
-
Sewershed 29C
I - Outfall - Siphon C
-
Sewershed 30C
- Outfall - Gravity Mains D
C Sewershed 31C
Unaffected Sewer Sheds i Sewershed 32C
Outfall - Gravity Mains D
Outfall - Siphon C
0 Outfall - Gravity Mains C
Outfall - Gravity Mains B
L
t:::::.

Vallecitos Water District
California Pacific Homes & AOA
Mixed Use W & S Study
Existing Sewer Facilities in
Study Area
April 2023
Figure 6
(
~ .

Californi a Pacifi c Hom es & AO A San M arcos LLC. Mixed Use W ater and Sewe r Study FINAL Techni ca l Memorandum
April 26, 2023

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Wastewater Treatment Faeility Analysis
VWD utilizes two wastewater treatment facilities to treat wastewater collected within its sewer service area .
The Meadowlark Reclamation Facility (MRF) has liquids treatment capacity of up to 5.0 MGD with a peak wet weather capacity of 8.0 MGD. MRF does not have solids treatment capacity , and therefore all solids are treated at the Encina Water Pollution Control Facility (EWPCF).
The EWPCF is located in the City of Carlsbad . This is a regional facility with treatment capacity ofup to 40.51 MGD . VWD's current ownership capacity is noted below.

Solids Treatm ent Capacity
VWD currently owns 10.47 MGD of solids treatment capacity at EWPCF . VWD 's 2014 average daily wastewater flow was 7.5 MGD. Therefore , the analysis finds that adequate solids treatment capacity exists at this time to serve the Project.

The ultimate average wastewater flow identified in the 2018 Master Plan is 14.4 MGD, resulting in a projected solids treatment capacity deficiency of3 .93 MGD. Wastewater Capital Facility Fees paid by this Project will be used towards the deficiency to accommodate the solid treatment capacity wastewater flow .

Liquids Treatment Capacity
VWD currently owns 7.67 MGD of liquids treatment capacity at the EWPCF in addition to the liquid's treatment capacity of 5.0 MGD at MRF for a total of 12.67 MGD of liquids treatment capacity. VWD 's 2014 average daily wastewater flow was 7.5 MGD . Therefore , the analysis finds that adequate liquids treatment capacity exists at this time to serve the Project.

The ultimate average wastewater flow identified in the 2018 Master Plan is 14.4 MGD, resulting in a projected liquids treatment capacity deficiency of 1.73 MGD . Wastewater Capital Facility Fees paid by this Project will be used towards the deficiency to accommodate the ultimate average wastewater flow.

Ocean Disposal Capacity
VWD currently owns 10.47 MGD of ocean disposal capacity at the EWPCF. VWD's 2014 average daily wastewater flow was 7.5 MGD. Therefore, the analysis finds that adequate ocean disposal capacity exists at this time to serve the Project.

The ultimate average wastewater flow identified in the 2018 Master Plan is 14.4 MGD , resulting in an ocean disposal deficiency of 3.93 MGD. Wastewater Capital Facility Fees paid by this Project will be used towards the deficiency to accommodate the ocean disposal wastewater flow.

The District has determined that adequate wastewater treatment and disposal capacity exists for the proposed Project at this time subject to the qualifications referenced in the Conclusions and Conditions.

Ca li fornia Pacific Homes & AOA San Marcos LLC. Mixed Use Water and Sewe r Study FINAL Technical Memora ndum
April 26, 2023

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CONCLUSIO N AND CONDITIONS
The proposed California Pacific Homes & AOA Mixed-Use Project is expected to increase average daily water demands by 28,967 gallons per day and wastewater flows by 21 ,097 gallons per day over the ultimate flows projected in the 2018 Master Plan.

The study concludes that the proposed development will result in the following impacts:
An increase of 28,967 gallons per day in water demand for proposed project. An increase of 144,895 gallons of potable water storage requirement. An increase of 21 ,097 gallons per day in solids handling , liquids handling and ocean disposal capacity requirements at Encina Water Pollution Control Facility . An increase of 21 ,097 gallons per day in the parallel land outfall's capacity requirement.

The following conditions are required for providing service to the proposed Project:
Payment of all applicable Water and Wastewater Capital Facility Fees in affect at the time service is committed in accordance with District rules and regulations. Construction and Board acceptance of all on-site and off-site water and sewer facilities prior to service.

The District currently has water and sewer capacity available to serve the Project as proposed with the conditions herein add1_·essed by the Developer. However , the ability to provide _water and sewer service in the future depends upon ultimate build-out of the Project and could change depending upon the timing of the build-out , as well as build-outs of other development projects , continued reliable water supplies from the San Diego County Water Authority , the District 's h·eatment capacity at the EWPCF and other factors affecting growth in the District which may change over time.

This Study is based on the current adopted land use utilized in VWD's 2018 Master Plan. The study addresses the incremental facility impacts of this Project only and does not include or consider any additional projects within VWD's service area that have deviated from adopted Master Plan land uses. Any land use changes upstream and/or downstream of the Study area may necessitate a revision of any onsite and offsite studies . VWD shall determine if and when revisions to the Study are necessary. Costs for revising this Study shall be borne by the Developer. The results of this study are not the accepted conditions for the development , final conditions shall be part of the construction agreement process or issued separately by the District.

San Marcos City CouncilOctober 24, 2023

San Marcos City Council
October 24, 2023