V ALLECITOS WATER DISTRICT
WOODWARD46WATERANDSEWERSTUDY
WORK ORDER # 26976 7
FINAL TECHNICAL MEMORANDUM
April 6, 2023
Prepared By: Elizabeth Lopez, Development Services Senior Engineer, and Eileen Koonce
INTRODUCTION
The proposed Woodward 46 project (Project) is a 46-unit multi-family residential development on
8.6-acres, located on Woodward Street north of Mission Road in the City of San Marcos (APN 220-210-49) .
The Project is located within Vallecitos Water District's (VWD) boundaries for water and wastewater service. The property does not need to annex, both water and wastewater services can be provided by VWD.
All new projects undergo evaluation by VWD to determine if the cun-ent water and sewer infrastructure 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 infrastructure 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.
► Wastewater land outfall, including the need to construct a parallel land outfall to serve this and other proposed developments .
Woodward 46 Water and Sewer Study
FINAL Technic al Memorandum
April 6, 2023
► 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.
WAT ER SYSTEM ANALYSIS
The proposed 8.6-acre Project lies completely within VWD 's 920 Pressure Zone. Figures 1 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 Pr0jec# ons
The Project prope1ty is within the City of San Marcos ' Richmar Specific Plan Area which allows for mixed-use , residential , retail and office uses. VWD's 2018 Master Plan based its ultimate water demand planning on the Residential 2-4 du/ac land use. The Project is proposing 46 multi family residential units on 8.6 acres (Residential 4-8 du/ac). Table 1 provides the average water demand generated both under the density planned for the 2018 Master Plan and for the proposed Project. The table shows that the Woodward 46 project will increase the projected average water demand from the 2018 Master Plan land use by 6,020 gallons per day.
Table 1 - Project Estimated Water Demands for Woodward 46 Land Use Type Area Residential Duty Factor Water Demand acres Units d/ac d
2018 Master Plan Land Use Demand
Residential 2-4 du/ac 8.60 1,800 15,480
Total 2.51 15,480
Proposed Project Demand
Residential 4-8 du/ac 8.60 46 2,500 21 ,500
Total 2.51 21,500
Water Demand Increase 6,020
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
-
20 " Diameter
Pipel
ine
24 " Diameter
Pipeline
27 " Diameter
Pipeline
30"
Diameter
Pipeline
,_
36"
Diameter
Pipeline
42 " Diameter
Pipeline
Unaffected
Pipeline
-
Proposed
Project
I c::J
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Pressure
Zones
-
Twin
Oaks
1028
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855
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Woodward
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Figure
1 Legend: ~
920
Zone
PRV
•
Storage
Tank
Affected
Pipeline
-
2"
Diameter
Pipeline
-
4"
Diameter
Pipeline
6"
Diameter
Pipeline
-
8"
Diameter
Pipeline
-
10"
Diameter
Pipeline
-
12"
Diameter
Pipeline
-
14"
Diameter
Pipeline
-
16"
Diameter
Pipeline
-18"
Diameter
Pipeline
-
20"
Diameter
Pipeline
-
24"
Diameter
Pipeline
-
27"
Diameter
Pipeline
-
30"
Diameter
Pipeline
-
36"
Diameter
Pipeline
Proposed
Project
855Zone
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February
2023
Figure
2 Woodward 46 Water and Sewer Study
FINA L Technical Memorandum
April 6, 2023
Wa-ter »lstrrib11trfon, Systrem AnalJsis
The 2018 Master Plan water system distribution and pressure criteria are as follows:
Water Distribution Jnfi-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 500 gpm for the Project.
To avoid excessive velocity and headloss within the distribution system, the following pipeline design criteria was also utilized:
► Maximum allowable velocity:
► Maximum allowable headloss gradient:
► Hazen-Williams C-factor:
Water Model Scenarios
7 feet per second
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 maximum day plus fire flow demand conditions.
Woodw ard 46 Water and Sewer Stud y
FINAL Technical Memorandum
April 6, 2023
Water Storag e A1,a.lys,is
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 2 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 2 - 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 6,020 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:
6,020 gallons * 500% = 30,100 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 .
Water Pump Stali0n 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.
Woodward 46 Water and Sewer Study
FIN AL Technical Memorandum
April 6, 2023
WASTEWATER SYSTEM ANALYSIS
The proposed 8.6-acre Project lies completely within VWD sewer shed 17C. Figures 3 through 6 show the development 's location in relation to sewer shed boundaries , identify wastewater infrastructure within the vicinity of the development, and identify the downstream collection infrastructure that will be impacted by the development.
Wastewater Fl0Jv Projections
The Project prope1ty is within the City of San Marcos ' Richmar Specific Plan Area which allows for mixed-use , residential , retail and office uses. VWD's 2018 Master Plan based its ultimate water demand planning on the Residential 2-4 du/ac land use. The Project is proposing 46 multi family residential units on 8.6 acres (Residential 4-8 du/ac). Table 3 provides the average wastewater flow generated both under the density planned for the 2018 Master Plan and with the proposed Project. The table shows that the Project will increase the projected average wastewater generation from the 2018 Master Plan land use by 4,730 gallons per day.
Table 3 - Project Estimated Wastewater Flows for Woodward 46 Land Use Type Area Residential Duty Factor Wastewater Flow (gpd) acres Units d/ac 2018 Master Plan Land Use Flows
Residential 2-4 du/ac 8.60 750 6,450
Total 6,450
Proposed Project Demand
Residential 4-8 du/ac 8.60 46 1,300 11,180
Total 1.09 11,180
Sewer Generation Increase 4,730
Legend Affected
gravity
mains
12"
Diameter
Pipeline
-
8"
Diameter
Pipeline
-
15"
Diameter
Pipeline
-
18"
Diameter
Pipeline
-
27"
Diameter
Pipeline
-
36 " Diameter
Pipeline
-
39"
Diameter
Pipeline
-
42"
Diameter
Pipeline
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Figure
3 Legend Affected
gravity
mains
-
8" Diameter
Pipeline
12 " Diameter
Pipeline
-
18"
Diameter
Pipeline
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27 " Diameter
Pipeline
-
36"
Diameter
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4 Legend Affected
gravity
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-
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22C
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46 Water
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February
2023
Figure
5 Legend Affected
gravity
mains
-
39"
Diameter
Pipeline
-
42"
Diameter
Pipeline
-
Unaffected
Pipeline
Sewershed
22C
-
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31C
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No.
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Figure
6 Wood ward 46 Water and Sewer Stud y
FTNAL Technical Memorandum
April 6, 2023
Wllstewaler C0llecti0n Sxstem Amilysis
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 D1y 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 D1y Weather Flow Ratey 0• 1618 The wet weather peak curve is:
Peak Wet Weather Factor= 2.78 x (Average Dry Weather Flow Ratey 0•087 Woodward 46 Water and Sewer Study
FINAL Technical Memorandum
April 6, 2023
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. 1 on San Marcos Boulevard that would be impacted by the proposed Project flows (see Figures 3 - 6).
Table 4 presents a summaiy of the modeling results from this analysis. The modeling results showed that there are deficiencies in pipe segment W-8 under the cunently approved density under peak wet weather flows during ultimate build-out conditions. The wastewater flows from the proposed Project will increase those deficiencies.
VWD's 2018 Master Plan has identified pipe segments W-8 and W-9 forupsizing from 18-inch to 24-inch diameter pipe. These segments are pa11 of CIP project #SP-34, a phase 4 project. Phase 4 projects are planned for construction in the 2031 to 2035 timeline.
Woodward
46 Wa
ter
and
Sewer
Study
FINAL
Technical
Memorandum
April
6, 2023
Page
14 of
21 Table
4 -Wastewater
Model
Results
and
Recommended
Gravity
Main
Improvements
Wastewater
Flows
with
Existing
Density
Wastewater
Flows
with
Proposed
Density
Peak
Wet
PWWF
Replacement
Peak
Wet
PWWF
Replacement
Pipe
ID
Length
Diameter
Slope
Weather
Depth-to-
Replacement
PWWF
Depth-
Weather
Depth-to-
Replacement
PWWF
Depth-
Number
(ft)
(in)
Flow
(gpm)
Diamter
Diamater
(in)
to-D
ia mater
Flow
(gpm)
Diamter
Diameter
(In)
to-Diamater
Ratio
Ratio
Ratio
Ratio
W-1
217
8 0
.0660
0 0
.01
8 0.01
13 0.07
-
8 0.07
W-2
222
12 0.0660
0 0
.01
12 0.01
13 0.05
12 0.05
W-3
359
12 0.0250
1236
0.50 12
0.50 1,249
0.50 12
0.50 W-4
216
18 0
.0030
1449
0.54 18
0.54 1,462
0.54 18
0.54 W-5
217
18 0.0040
1451
0.50 18
0.50 1,464
0.50 18
0.50 W-6
350
18 0.0040
1466
0.50 18
0.50 1,479
0.50 18
0.50 W
-7
80 18
0.0040
1475
0.50 18
0.50 1,488
0.50 18
0.50 W
-8
170
18 0.0040
2725
0.76 24
0.46 2,738
0.76 24
0.46 W-9
62 18
0.0180
2727
0.46 24
0.31 2,740
0.47 24
0.31 W-10
31 27
0.0030
2729
0.42 27
0.42 2,742
0.42 27
0.42 W-11
165
27 0.0050
2731
0.37 27
0.37 2,744
0.37 27
0.37 W-12
261
27 0.0080
2741
0.32 27
0.32 2;754
0.32 27
0.32 W-13
135
36 0.0030
6222
0.43 36
0.43 6,235
0.43 36
0.43 W-14
128
36 0.0050
6247
0.38 36
0.38 6,260
0.38 36
0.38 W-15
140
36 0.0070
6248
0.35 36
0.35 6,261
0.35 36
0.35 W-16
470
36 0.0040
6250
0.40 36
0.40 6,263
0.40 36
0.40 W-17
184
36 0.0030
6265
0.43 36
0.43 6,278
0.43 36
0.43 W-18
36 36
0.0020
6267
0.49 36
0.49 6,280
0.49 36
0.49 W-19
146
36 0.0050
6268
0.38 36
0.38 6,281
0.38 36
0.38 W-20
318
36 0.0040
6625
0.41 36
0.41 6,638
0.41 36
0.41 CIP
PROJECTS:
jW-8
&
W
-9
CIP
SP-34
(P
hase
4)
PROPOSED
DENSITY:
!
13 !GPM
Woodward
46 Water
and
Sewer
Study
FINAL
Technical
Memorandum
Ap
ril 6, 2023
Page
15 of
21 Table
4 -Wastewater
Model
Results
and
Recommended
Gravity
Main
Improvements
Wastewater
Flows
with
Existing
Densi
ty
Wastewater
Flows
with
Proposed
Density
Peak
Wet
PWWF
Replacement
Peak
Wet
PWWF
Replacement
Pipe
ID
Length
Diameter
Slope
Weather
Depth
-to-
Replacement
PWWF
Depth-
Weather
Depth-to-
Replacement
PWWF
Depth-
Number
(ft)
(in)
Flow
(gpm)
Diamter
Diamater
(in)
to-Diamater
Flow
(gpm)
Diamter
Diameter
(In)
to-Diamater
Ratio
Ratio
Ratio
Ratio
W-21
39 36
0.0040
6626
0.41 36
0.41 6,639
0.41 36
0.41 W-22
319
36 0.0040
6627
0.41 36
0.41 6,640
0.41 36
0.41 W-23
38 36
0.0040
6628
0.41 36
0.41 6,641
0.41 36
0.41 W-24
139
36 0.0040
8764
0.48 36
0.48 8,776
0.48 36
0.48 W-25
294
36 0.0030
8764
0.53 36
0.53 8,777
0.53 36
0.53 W-26
12 36
0.0170
8764
0.33 36
0.33 8,777
0.33 36
0.33 W
-27
438
36 0.0050
8767
0.45 36
0.45 8,780
0.45 36
0.45 W-28
229
36 0.0050
8769
0.45 36
0.45 8,782
0.45 36
0.45 W
-29
371
36 0.0060
8772
0.43 36
0.43 8,785
0.43 36
0.43 W-30
124
36 0.0050
8774
0.45 36
0.45 8,787
0.45 36
0.45 W-31
167
36 0.0050
8776
0.45 36
0.45 8,789
0.45 36
0.45 W-32
201
36 0.0040
9070
0.49 36
0.49 9,083
0.49 36
0.49 W-33
91 36
0.0050
9072
0.46 36
0.46 9,085
0.46 36
0.46 W
I
r,A
,..,..,..
36 0.0050
9073
0.46 36
0.46 9,086
0.46 36
0.46 -.)"t
LLU
W-35
286
36 0.0050
9073
0.46 36
0.46 9,086
0.46 36
0.46 W-36
210
39 0.0040
9165
0.44 39
0.44 9,178
0.44 39
0.44 W-37
176
39 0.0030
9166
0.48 39
0.48 9,179
0.48 39
0.48 W-38
271
39 0.0020
9167
0.54 39
0.54 9,180
0.54 39
0.54 W-39
297
39 0.0020
9167
0.54 39
0.54 9,180
0.54 39
0.54 W-40
452
39 0.0020
9168
0.54 39
0.54 9,181
0.54 39
0.54 CIP
PROJECTS:
!CA-4
through
CA
-14
(SP-23)
Phase
4 PROPOSED
DENSITY:
I
13 iGPM
Woodward
46 Water
and
Sewer
Study
FINAL
Technical
Memorandum
April
6, 2023
Page
16 of
21 Table
4 -Wastewater
Model
Results
and
Recommended
Gravity
Main
Improvements
Wastewater
Flows
with
Existing
Density
Wastewater
Flows
with
Proposed
Density
Peak
Wet
PWWF
Replacement
Peak
Wet
PWWF
Replacement
Pipe
ID
Length
Diameter
Slope
Weather
Depth-to-
Replacement
PWWF
Depth-
Weather
Depth-to-
Replacement
PWWF
Depth-
Number
(ft)
(in)
Flow
(gpm)
Diamter
Diamater
(in)
to-Dia
mater
Flow
(gpm)
Diamter
Diameter
(In)
to-Dia
mater
Ratio
Ratio
Ratio
Ratio
W-41
337
39 0.0020
9171
0.54 39
0.54 9,184
0.54 39
0.54 W-42
123
39 0.0080
9364
0.37 39
0.37 9,377
0.37 39
0.37 W-43
58 42
0.0040
9366
0.40 42
0.40 9,379
0.40 42
0.40 W-44
308
42 0.0030
9369
0.43 42
0.43 9,382
0.43 42
0.43 W-45
69 42
0.0010
9375
0.60 42
0.60 9,388
0.60 42
0.60 W-46
448
42 0.0030
9378
0.43 42
0.43 9,391
0.43 42
0.43 W-47
448
42 0.0030
9382
0.43 42
0.43 9,395
0.43 42
0.43 W-48
404
42 0.0060
9736
0.37 42
0.37 9,749
0.37 42
0.37 W-49
404
42 0.0060
9742
0.37 42
0.37 9,755
0.37 42
0.37 W-50
368
42 0.0030
9749
0.44 42
0.44 9,762
0.44 42
0.44 W-51
368
42 0.0030
9752
0.44 42
0.44 9,765
0.44 42
0.44 W-52
368
42 0.0030
9755
0.44 42
0.44 9,768
0.44 42
0.44 W-53
120
42 0.0020
9809
0.50 42
0.50 9,822
0.50 42
0.50 W
-54
'21::')
42 0.0040
9810
r,
A
A
42 0.41
9,823
0.41 42
0.41 ,J,JL
U
."t
I
W-55
472
42 0.0080
9810
0.34 42
0.34 9,823
0.34 42
0.34 W-56
467
42 0.0040
9811
0.41 42
0.41 9,824
0.41 42
0.41 W-57
460
42 0.0040
9812
0.41 42
0.41 9,825
0.41 42
0.41 W-58
8 42
0.0290
9819
0.25 42
0.25 9,831
0.25 42
0.25 W-59
310
42 0.0050
9817
0.39 42
0.39 9,830
0.39 42
0.39 W-60
372
42 0.0040
9816
0.41 42
0.41 9,829
0.41 42
0.41 CIP
PROJECTS:
CA-4
through
CA-14
(SP-23)
Phase
4 PROPOSED
DENSITY:
!
13 !GPM
Woodward
46 Water
and
Sewer
Study
FINAL
Techn
ical
Memorandum
Apr
il 6
, 2023
Page
17 of
21 Table
4 -Wastewater
Model
Results
and
Recommended
Gravity
Main
Improvements
Wastewater
Flows
with
Existing
Density
Wastewater
Flows
with
Proposed
Density
Peak
Wet
PWWF
Replacement
Peak
Wet
PWWF
Replacement
Pipe
ID
Length
Diameter
Slope
Weather
Depth-to-
Replacement
PWWF
Depth-
Weather
Depth-to-
Replacement
PWWF
Depth-
Number
(ft)
(in)
Flow
(gpm)
Diamter
Diamater
(in)
to-Dia
mater
Flow
(gpm)
Diamter
Diameter
(In)
to-Dia
mater
Ratio
Ratio
Ratio
Ratio
W-61
355
42 0.0050
9825
0.39 42
0.39 9,838
0.39 42
0.39 W-63
190
42 0.0050
9823
0.39 42
0.39 9,836
0.39 42
0.39 W-64
316
42 0.0040
9821
0.41 42
0.41 9,834
0.41 42
0.41 W-65
94 42
0.0060
9820
0.37 42
0.37 9,833
0.37 42
0.37 W
-66
112
42 0.0060
9819
0.37 42
0.37 9,832
0.37 42
0.37 W-67
100
42 0.0020
14041
0.62 42
0.62 14
,054
0.62 42
0.62 W-68
347
42 0.0020
14048
0.62 42
0.62 14
,061
0.62 42
0.62 W-69
18 42
0.0030
14049
0.54 42
0.54 14
,062
0.55 42
0.55 W-70
10 42
0.0020
1405
1 0.62
42 0.62
14 ,064
0.62 42
0.62 W-71
10 42
0.0120
14243
0.37 42
0.37 14
,255
0.37 42
0.37 W-72
73 42
0.0040
14243
0.50 42
0.50 14
,255
0.50 42
0.50 CIP
PROJECTS:
CA
-4
thro
ugh
CA-14
(SP-2
3) Phase
4 PROPOSED
DENSITY:
I
13 )GPM
Woodward 46 Water and Sewer Study
FfNAL Technical Memora ndum
April 6, 2023
W{l<Stewater Lift St{lltion Amtll);sis
Lift stations are sized for peak wet weather flow with manufachirer'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 L{lnd Ouifall Analysis
VWD 's existing land outfall is shown in Figure 7. 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 maintains 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 5 below:
Table 5 - 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 of20.10 MGD (12.10 MGD + 8.0 MGD).
VWD's 2014 average daily wastewater flow through the land outfall was 7.5 MGD. This coITesponds 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 c01Tesponds 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 4,730 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 cuITently 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 accommodate ultimate build-out wastewater flows.
Legend -
Outfall
-Gravity
Mains
A
C
Sewershed
21C
-
Outfall
-Siphon
A
c..
Sewershed
22C
-
Outfall
-Gravity
Mains
B
-
Sewershed
27C
Outfall
Siphon
B
C
Sewershed
28C
Outfall
-Gravity
Mains
C
-
Sewershed
29C
-
Outfall
-Siphon
C
-
Sewershed
30C
-
Outfall
-Gravity
Mains
D
C
Sewershed
31 C
Unaffected
Sewer
Sheds
i
Sewershed
32C
,
Outfall
-Gravity
Mains
D
.
\
~ .., , Encina
Water
Pollution
~
Control
Facility
-~ ,, ../"' ~¾ ✓....,.. ·~
,...-y_
~p
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ac1
,c,
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,-.
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cea
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r
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-"11
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r,
/
,
' rs
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'~
~-
..,,._
~ ',,
I
0 Outfall
-Gravity
Mains
C
Outfall
-Gravity
Mains
B
JJ 0
~
EC,1i
S\WO
26500
.0 ,269999
F'rojectslWO
269767
-Woodwarct
4°6
WS
St
udy\Figures\Woodward
46 Water&
Sewer
Study
'.Area
Fig7
,mxd
~-
1 ~
"-,·
L
t:::::,,
Vallecitos
Water
District
Woodward
46 Water
&t
Sewer
Study_
Existing
Sewer
Facilities
in
Study
Area
February Figure
7 \ ~
i
Woodward 46 Water and Sewer Study
FINAL Teclrnical Memorandum
April 6, 2023
W a:steu,atec Treatment Faei#ity 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 Treatment 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 of 3.93 MGD. Wastewater Capital Facility Fees paid by this Project will be used towards the deficiency to accommodate the solid h·eatment capacity wastewater flow.
Liquids Treatment Capacity
VWD currently owns 7.67 MGD of liquids h·eatment capacity at the EWPCF in addition to the liquid's h·eatment 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 acc01mnodate 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.
Woodward 46 Water and Sewe r Stud y
FINAL Technical Memorandum
April 6, 2023
CONCLUSION AND CONDITIONS
The proposed Woodward 46 project is expected to increase average daily water demands by 6,020 gallons per day and wastewater flows by 4,730 gallons per day over the ultimat e flows projected in the 2018 Master Plan.
The study concludes that the proposed development will result in the following impacts:
► An increase of 6,020 gallons per day in water demand for proposed project. ► An increase of 30,100 gallons of potable water storage requirement. ► An increase of 4,730 gallons per day in solids handling , liquids handling and ocean disposal capacity requirements at Encina Water Pollution Control Facility. ► An increase of 4,730 gallons per day in the parallel land outfall's capacity requirement.
The Study also concludes that there are deficiencies in the existing sewer facilities under peak wet weather flows dming ultimate build-out conditions without the addjtion of the Project. The following improvements are needed to mitigate those deficiencies:
► Approximately 232 feet of existing 18-inch sewer main within a VWD easement along San Marcos Creek must be replaced with 24-inch main (W-8 and W-9).
VWD 's 2018 Master Plan has identified pipe segments W-8 and W-9 for upsizing from 18-inch to 24-inch diameter pipe as pait of CIP #SP-34 , a Phase 4 project. Phase 4 projects are planned for construction in the 2031 to 2035 timeline.
Since there is cmTently capacity in pipes W-8 and W-9 and the need for additional capacity in these sewer mains is not anticipated until Phase 4, the CIP #SP-34 project will address and accommodate the pipeline deficiencies. Wastewater Capital Facility Fees paid by this Project will be used towards the construction of these pipelines.
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 onsite and offsite water and sewer facilities p1ior to service. Includes installation of Sewer Pipes W-1 and W-2.
The District currently has water and sewer capacity available to serve the Project as proposed with the conditions herein addressed 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 treatment 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 Woodward 46 Water and Sewer Study
FINAL Technical Memorandum
April 6, 2023
necessitate a revision of any onsite and offsite studies. VWD shall determine 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.