Fairfield City Council
May 6, 2025

Chapter 2
Existing Water System
N-C-268-60-22-20-WP-R-WMP
2-11 City of Fairfield
Public Utility Master Plan
March 2025

2.3 WATER SYSTEM FACILITIES
The City’s key water system facilities, including water treatment plants, storage reservoirs, pump stations, and pipelines, are shown on Figure 2-3. Existing control valve and meter vaults are shown on Figure 2-5.

Figure 2-4 provides an overall schematic diagram of the City’s existing water system showing the existing water system facilities at their approximate elevations. Each facility type is discussed in more detail in the following sections. The evaluations of facility capacities and their ability to meet existing and future water demands are described in Chapter 6 Existing Water System Evaluation and Chapter 7 Future Water System Evaluation.

2.3.1 Water Treatment Plants (WTP)
The City’s raw water supply is treated at two water treatment plants:
• Waterman WTP
• North Bay Regional (NBR) WTP
Each water treatment plant is briefly described below. For additional details related to the results from the condition assessment of each water treatment plant, refer to Chapter 8 Condition and Risk Assessments.

2.3.1.1 Waterman WTP
Waterman WTP is the oldest of the City’s two treatment plants. Waterman WTP was originally constructed in 1974 and has been renovated several times, with the latest expansion/modernization project completed in 2010. The Waterman WTP is owned and operated by the City and has a treatment capacity of 30 mgd. It is located within City limits at 2900 Vista Grande, just north of the Putah South Canal. The Waterman WTP treats Solano Project water through a combination of chemical flash mixing, Actiflo Ballasted sand sedimentation, ozone contactor trains, filtration, and disinfection.

2.3.1.2 North Bay Regional (NBR) WTP
NBR WTP was constructed in 1991. Its primary purpose was to provide treatment of SWP supply, which have higher organics than the Solano Project water supply. It is jointly owned by the City of Fairfield and the City of Vacaville. The total treatment capacity of NBR WTP is 40 mgd, of which the City is entitled to

26.7 mgd, or 66 percent of the overall capacity. It is operated by and located within the City at 5110 Waterworks Lane. NBR WTP treats both SWP and Solano Project water through a combination of pre-ozonation, flash mixing, flocculation-sedimentation, filtration, and chlorination.

N o tes:

1.Referto Figure 2-3fo rn a m es o fexistin g w a tertrea tm en tpla n ts,pum p sta tio n s, a n d reservo irs.

2.Referto Ta b le 2-6fo ra sum m a ryo fthe cha ra cteristics o fexistin g co n tro l va lve a n d m etervaults.

3.Referto Ta b le 2-7fo ra sum m a ryo fthe cha ra cteristics o feixistin g pressure reducin g va lves.

Cement Hill
Valve Vaults
Hale Ranch
Valve Vaults
Detail Map 1 - Scale: 1 in = 200 feet
Detail Map 2 - Scale: 1 in = 200 feet
Detail Map 3 - Scale: 1 in = 1,000 feet
Refer to
Detail Map 1
Refer to
Detail Map 2
Refer to
Detail Map 3
80 80
680
12 12
12 Waterman WTP
North Bay
Regional WTP
Bayridge Valve
Vault
Nelson Hill
Bypass Vault
Paradise
Valley
Meter Vault
West America
Valve Vault
12 10
8 9
7 1
5 4
15 14
2 16
3 13
11 17
6 18
Prepa red b y: Prepa red fo r:

Figure 2-5
WESTY OST-N :\Clien ts\268Fa irfield\60-22-20Wa terMa sterPla n \GIS\MX D\Fig2-5_ Va lveVaults.m xd -w jo n es -11/11/2024 0 2,000 4,000
Meters
0 7,000 14,000
Feet
City of Fairfield
Public Utility Master Plan
Existing Control Valve Vaults, Meter Vaults, and
Pressure Reducing Valves
Wa terTrea tm en tPla n t
Pum p Sta tio n
Reservo ir
Co n tro lVa lve o rMeterVa ult
Pressure Reducin g Va lve
(With IDN um b er;Referto Ta b le Belo w )
Distrib utio n Pipelin e (<24-in ches)
Tra n sm issio n Pipelin e (≥ 24-in ches)
Cro ssto w n Pipelin e
Ea stridge Reservo irPipelin e
CityLim its
Pressure Zones
Zo n e 1
Zo n e 2
Zo n e 3
Zo n e 4
Zo n e 5
Sout hbro ok
(Zone 2 )
Red Top
(Zone 2 )
Zone 1
Mang e ls
(Zone 2 )
Gol dri dge
(Zone 2 )
Pa rad is e /
Roll ing H ill s /
Ma rti n Hi ll
(Zone 2 )
Zone 5
Rancho /
Sanc tu a ry
(Zone 3 )
Zone 4
Ea s tridge
(Zone 3 )
Pa rad is e /
Roll ing H ill s /M a rt in H ill
(Zone 2 )
Cement Hill
Valve Vault 2
Cement Hill
Valve Vault 3
Cement Hill
Valve Vault 4
Cement Hill
Valve Vault 5
Cement Hill
Valve Vault 1
4 Zone 1
Hale Ranch
Valve Vault 2
Hale Ranch
Valve Vault 1
Zone 1
Pa rad is e /R olli ng H ills /
Ma rti n Hi ll ( Zone 2 )
Bridge Valve Vault
Waterman
WTP
Crossover
Valve
East Valve
West
Distribution
Valve
High
Service
Valve
Valve ID Number Valve Name
1 Pea b o dyPRV42-1
2 Ellis Go dfreyPRVZ-2
3 Cem en tHillPRV42-1
4 Ma n uelCa m po s PRVZ-2
5 Pa lo m in o PRVZ-2
6 Ea stTa b o rPRVCT-1
7 Bea rCreek PRVZ-3
8 DelMo n te PRVZ-3
9 Co tsw o ld PRVZ-3
10 OliverPRVZ-2
11 Pen n sylva n ia PRVCT-1
12 Cha db o urn e PRVZ-1
13 Co rdelia PRVCT-1
14 Busin ess Cen terPRVZ-1
15 Bridle Ridge PRVZ-2
16 Sprin g Ridge PRVZ-2
17 Bra n din g Iro n PRVZ-2
18 Sa n ctua rySC3
Pressure Reducing Valve (PRV) ID Table

Chapter 2
Existing Water System
N-C-268-60-22-20-WP-R-WMP
2-13 City of Fairfield
Public Utility Master Plan
March 2025

2.3.2 Transmission System Overview
The City has a system of transmission mains that provide operational flexibility to move water from both the Waterman WTP and the NBR WTP to different regions throughout the City. This transmission system is illustrated on Figure 2-5, along with valves and meter vaults.

From the Waterman WTP, five (5) dedicated high lift pumps convey water to the adjacent Waterman Reservoir through the High Service Valve or to meet demands and fill storage reservoirs in Zone 1.

Waterman Reservoir supplies the Rancho Solano 3 Pump Station and supplies Zone 1, as needed, through the Crossover Valve or the East Valve, both of which are shown on Figure 2-5. The 48-inch diameter transmission pipeline that conveys water from the Waterman WTP southwest to Nelson Hill Reservoir is referred to as the Nelson Hill Transmission Line (NHTL). The Anheuser-Busch brewery located at 3103 Busch Drive is the first customer to receive water from the NHTL. There is also a dedicated transmission pipeline that conveys water to and from Eastridge Reservoir to the NHTL, referred to as the Eastridge Reservoir Pipeline. Flow to the east from Waterman WTP is conveyed via the East Valve and a 30-inch diameter transmission pipeline.

From the NBR WTP, six (6) dedicated pumps convey water southwest to Cement Hill Reservoir via a 42-inch diameter transmission pipeline, as illustrated on Figure 2-5. There are two pressure reducing valves (PRV) located along the 42-inch diameter transmission pipeline: (1) Peabody PRV42-1 and (2) Cement Hill PRV42-1. Peabody PRV42-1 is currently operated wide open; however, the City plans to convert Peabody PRV42-1 to a motor operated valve (MOV). Cement Hill PRV42-1 is normally closed and only opens when Zone 1 pressures drop below the set point. The City also has the option to bypass Cement Hill Reservoir and convey water directly to Zone 1 or through the Cross Town Pipeline, which is further described below. Flow is conveyed through the Cross Town Pipeline via the Cement Hill Bypass Valves located just down the hill from Cement Hill Reservoir on Manuel Campos Parkway and Clay Bank Road.

The Cement Hill Valve Vaults are illustrated on Figure 2-5.

The Cross Town Pipeline is a transmission pipeline that was completed in 2019 after decades of planning and design. Completion of the pipeline has allowed the City to convey water from NBR WTP to the west side of the distribution system (e.g., Nelson Hill Reservoir and South Cordelia Reservoir), as well as convey Waterman WTP water to the east side of the distribution system (e.g., Cement Hill Reservoir). This providesthe City with conveyance capacity to enable either the NBR WTP or the Waterman WTP to supply the entire water system, should the need arise. The Cross Town Pipeline also provides greater redundancy for the City’s water system, allowing the City to better use seasonally available water supplies. Prior to completion of the pipeline, the west side of the distribution system was entirely dependent upon supply from Waterman WTP. The City is currently identifying how to best operate this large transmission main, as the added operational flexibility has introduced new valve operations and methods for providing water to different regions throughout the City.

As illustrated on Figure 2-5, the Cross Town Pipeline begins on the east side of the City, just after Cement Hill Reservoir, and bypasses the City’s downtown area to tie into the distribution system at Hale Ranch Road and Cordelia Road. Two PRVs exist between Cement Hill Valve Vault 3 and the western termination, they are: (1) East Tabor PRVCT-1; and (2) Pennsylvania PRVCT-1. The Cross Town Pipeline is a 36-inch diameter transmission pipeline and runs approximately 7.5 miles.

Chapter 2
Existing Water System
N-C-268-60-22-20-WP-R-WMP
2-14 City of Fairfield
Public Utility Master Plan
March 2025
It should be noted that although water from NBR WTP can be conveyed west via the Cross Town pipeline, there are a series of check valves installed to prevent NBR WTP supply from reaching Eastridge Reservoir or Anheuser-Busch. This was done to meet the requirements of the City’s service agreement with AnheuserBusch, which requires that Anheuser-Busch be supplied with water from Waterman WTP only.

2.3.3 Storage Reservoirs
The City’s water system includes 12 storage reservoirs, with a total available storage capacity of 78.5 MG.

The reservoirs are shown on Figure 2-3 and Figure 2-4. Six (6) of the City’s storage reservoirs are multi-cell, buried concrete facilities, which offer the City seasonal flexibility in reservoir operations (e.g., a single 4 MG cell can be utilized at Eastridge Reservoir during low demand periods instead of utilizing the full 16 MG reservoir capacity). Five (5) storage reservoirs are located within Zone 1, the City’s largest pressure zone, and provide a maximum storage capacity of 53 MG. An additional five (5) storage reservoirs are located within Zone 2 and provide a maximum storage capacity of 21 MG. Three (3) of the Zone 2 reservoirs are located within Paradise/Rolling Hills/Martin Hill (Zone 2D) to provide a maximum storage capacity of 17.8 MG. Mangels (Zone 2C) has a 1.0 MG reservoir, and Goldridge (Zone 2E) has a 2.2 MG reservoir. The remaining two (2) reservoirs are in Zones 3 (Rancho Solano) and 4 and provide a storage capacity of 3.1 MG and 1.4 MG, respectively. Table 2-4 summarizes the key characteristics of the City’s existing storage reservoirs.

Figure 2-4 provides a schematic of the hydraulic grade provided by the City’s reservoirs to each pressure zone. The City’s reservoirs provide gravity storage and are located at a higher elevation than the pressure zone they serve. The reservoir fills when supply to the pressure zone is greater than the water demand and drains by gravity when the zone demand exceeds supply.

2.3.4 Pump Stations
The City currently operates 17 pump stations within the City’s water service area. The pump stations are shown on Figure 2-3 and Figure 2-4. Two (2) of the pump stations are located at the City’s water treatment plants (NBR WTP and Waterman WTP) and convey water from the treatment facilities into the Zone 1 distribution system via storage reservoirs and transmission pipelines, as described in Section 2.3.1 Water Treatment Plants. One (1) pump station in Zone 1—South Cordelia Pump Station—draws from the distribution system to pump water directly into the South Cordelia Reservoir to increase the reservoir’s water level above the levels in Nelson Hill Reservoir and Eastridge Reservoir and force turnover in the reservoir. If the South Cordelia Pump Station bypass is utilized, the South Cordelia Reservoir equalizes with Nelson Hill Reservoir and Eastridge Reservoir. The remaining 15 pump stations within the City pump water directly into the City’s upper pressure zones (Zones 2 through 5), to serve customers and fill the storage reservoirs or hydropneumatic tanks in the upper pressure zones.

Table 2-4. Summary of Existing Reservoirs
Reservoir Name
Facility
Abbreviation
Pressure
Zone
Year Installed/
Rehabilitated
Reservoir
Material
Diameter,
ft
Bottom
Elevation,
ft msl
Overflow
Elevation,
ft msl
Number of
Reservoir Cells
Cell Nominal
Storage Capacity,
MG
Nominal Storage
Capacity
MG
Zone 1
1 2.5
2 2.5
1 4.0
2 4.0
3 8.0
1 6.0
2 6.0
1 5.0
2 5.0
1 5.0
2 5.0

53.0 Zone 2
Mangels MGLR 2C 1993 Welded Steel 103 340 356 - 1.0 1.0

1.0 1 6.0
2 6.0
Rolling Hills RHR 2009 Welded Steel 143 300 325 - 3.1 3.1 Martin Hill MHR 2010 Welded Steel 135 300 325 - 2.7 2.7

17.8 Goldridge GRR 2E 2012 Welded Steel 122 275 301.5 - 2.2 2.2

2.2 21.0
Zone 3
Rancho Solano 3 RSR3 3B 2008 Welded Steel 143 400 425 - 3.1 3.1

3.1 Zone 4
Rancho Solano 4 RSR4 4 1989 Welded Steel 96 527 553 - 1.4 1.4

1.4 78.5
ft msl = feet mean sea level; MG = million gallons.

Total - All Pressure Zones
Subtotal - Zone 2D
Subtotal - Zone 2E
Total - Zone 2
Total - Zone 3
Total - Zone 4
Paradise Valley PVR 12.0
Total - Zone 1
1991 Buried Concrete Variable Area 302 326.5
2D
Waterman WTM 1974 Buried Concrete 228.0
Variable Area 203.5 12.0
Variable Area 203 228.0 10.0
Variable Area 202.8 10.0
Source: Data is from the City's Modeling Notebook (West Yost, April 2018).

South Cordelia SCR 2006 Buried Concrete Variable Area 204 229.5 5.0 Subtotal - Zone 2C

16.0 Nelson Hill NHR
Eastridge ERR 228.0
1984 Buried Concrete 228.0
2003 Buried Concrete Variable Area 203
1 Cement Hill CHR 1991 Buried Concrete
N-C-268-60-22-20-E-T2-T2.2-CH2
City of Fairfield
Public Utility Master Plan

Chapter 2
Existing Water System
N-C-268-60-22-20-WP-R-WMP
2-16 City of Fairfield
Public Utility Master Plan
March 2025
Each pump station contains two (2) to four (4) individual pumps, except for the pump stations located at Waterman WTP and NBR WTP, which contain five (5) and six (6) individual pumps, respectively. Where multiple pump units are available, one pump typically operates as an emergency standby unit. Nine (9) pump stations have a dedicated stationary generator with automatic transfer switches and the remaining pump stations have a manual transfer switch and portable generator hookups. The City has two portable generators that can be rapidly deployed to these stations.

In addition, apart from Red Top (Zone 2), which was under construction at the time of this PUMP, all pump stations that supply hydropneumatic zones (i.e., Southbrook 1, Southbrook 2, Eastridge, and Zone 5) are equipped with a fire pump. As explained in the basis of design (BOD) report6, the Red Top (Zone 2) Replacement Pump Station is a replacement of the existing Red Top Pump Station and is designed to serve existing demands and future demands that were proposed at the time the BOD was written. According to the February 2022 Improvement Plans7, the pump station design includes three (3) domestic pumps (lead, lag, and standby) sized at 600 gpm each and two (2) high flow pumps sized at 2,250 gpm each, for a total nominal capacity of 5,700 gpm. However, the existing Red Top (Zone 2) pump station capacity was used for the PUMP, since the new pump station was not in service when this evaluation was prepared. Table 2-5 summarizes the key characteristics of the City’s existing booster pump stations. The firm capacity shown in Table 2-5 is defined as the total pumping capacity with the largest pump unit out of service, excluding the fire pump, if present.

2.3.5 Control Valve Vaults, Meter Vaults, and Pressure Reducing Valves The City’s distribution system includes 13 control valve vaults which contain valves that regulate the transfer of water between pressure zones and/or service areas and one (1) meter vault with a meter that monitors flow across Interstate 80 within Paradise/Rolling Hills/Martin Hill (Zone 2D). The City also has 18 pressure reducing valves (PRVs), seven (7) of which are used within Zone 1 to reduce pressure from transmission pipelines into the distribution system. Some of these provide pressure regulation directly off the Cross Town Pipeline, which is further explained in a later section. The remaining eleven (11) operate between pressure zones to allow supply from a zone with a higher hydraulic grade into a zone with a lower grade, in the case of an emergency (e.g., a fire) which causes a rapid drop in pressure within the lower zone.

Figure 2-5 shows the location of each of the City’s major control valve and meter vaults, as well as its PRVs. Tables 2-6 and 2-7 summarize the key characteristics and functions of the City’s existing control valve/meter vaults and PRVs, respectively.
6 Creegan + D’Angelo Infrastructure Engineers, 2017. Red Top Replacement Zone II Pump Station Basis of Design Report (Final). February 2017.
7 Stetson Engineers, Inc., 2022. Improvement Plans for Red Top Zone II Pump Station Fairfield California. February 2022.

Chapter 2
Existing Water System
N-C-268-60-22-20-WP-R-WMP
2-17 City of Fairfield
Public Utility Master Plan
March 2025

2.3.6 Pipelines
The City maintains approximately 392 miles of transmission and distribution system pipelines. Tables 2-8, 2-9, and 2-10 summarize the City’s pipeline statistics by diameter, material type, and installation year. 8 The City’s distribution and transmission pipelines generally range in size from 6 inches in diameter to 48 inches in diameter. Distribution pipelines are generally classified as those 20 inches in diameter or smaller, while transmission pipelines generally range from 24 inches to 48 inches in diameter.

Transmission pipelines comprise approximately 10 percent (41 miles) of all pipelines within the City, while distribution pipelines comprise approximately 90 percent (351 miles). As shown in Table 2-9, the majority of the City’s pipelines—70 percent (or 275 miles)—are estimated to be made from asbestos cement (AC), followed by polyvinyl chloride (PVC)—28 percent (or 111 miles).

As part of the City’s bimonthly geographic information system (GIS) water system geodatabase updates, new system elements or changes to existing material and installation year of new pipelines are recorded based on engineering record drawings. There are pipelines in the GIS that predate the current update process and do not have a known material type and/or installation year. In these areas, an assumed material type was provided by City staff based on the pipeline location and the approximate construction year of the subdivision. As shown in Table 2-10, over 98 percent of the City’s pipelines were installed between 1950 and 2019, with nearly half of those installations occurring in the 1970s and 1980s. 8 Pipeline statistics presented in Tables 2-8 through 2-10 are based on the “Water_Mains” feature class within the City’s potable water GIS geodatabase. West Yost maintains the City’s potable water GIS geodatabase and performs bimonthly updates. The January 2023 GIS geodatabase, last updated on 1/20/2023, was used for this PUMP. Only active and installed pipelines owned by the City are included in the pipeline statistics.

Nominal
Capacity per
Pump, gpm(b)
Total
Capacity,
gpm
Firm
Capacity(c),
gpm
Zone 1
P1 200 177 3,500
P2 400 175 7,000
P3 600 175 10,500
P4 250 150 5,200
2009 P5 250 150 5,200
P1 100 165 1,400
P2 150 165 2,800
P3 150 165 2,800
P4 400 165 7,000
P5 400 165 7,000
1991 P6 400 165 7,000
P1 30 42 1,900
P2 30 42 1,900
P3 30 42 1,900
65,100 45,700
Zone 2
P1 20 100 450
P2 20 100 450
P3 20 100 450
P4 40 90 1,250
P1 20 105 450
P2 20 105 450
P3 20 105 450
P4 40 100 1,250
5,200 4,300
P1 25 123 580
P2 25 123 580
P3 50 93 1,450
2,610 1,160
P1 20 137 360
P2 20 137 360
720 360
P1 50 100 1,400
P2 50 106 1,400
P3 50 100 1,400
P1 50 115 1,400
P2 50 115 1,400
P3 50 115 1,400
P1 50 114 1,400
P2 50 114 1,400
P3 50 114 1,400
12,600 8,400
P1 40 100 1,000
P2 40 100 1,000
P3 40 100 1,000
P4 50 110 1,385
4,385 3,000
Zone 3
P1 20 195 180
P2 20 195 180
P3 20 195 180
P4 100 195 1,250
1,790 1,610
P1 60 245 705
P2 60 245 705
P3 60 245 705
P1 20 115 425
P2 20 115 425
P3 20 115 425
P4 50 115 1,250
4,640 2,685
Zone 4
P1 15 105 257
P2 20 105 257
P1 15 137 270
P2 15 137 270
P3 50 137 1,250
2,304 797
Zone 5
P1 3 136 25
P2 3 136 25
P3 8 137 150
200 175
(a) Facilities that have a dedicated stationary generator also include an automatic transfer switch. The remaining facilities that don't have a stationary generator present have a manual transfer switch and portable generator hookups. The City has two portable generators that can be rapidly deployed to these stations. (b) The capacity per pump is from the City's Modeling Notebook (West Yost, April 2018). (c) Firm pumping capacity is defined as the total pumping capacity with the largest pump unit out of service, excluding the fire pump (if present). (d) The Waterman High Lift Pump Station was originally built in 1974 and included P1, P2, and P3. In 1986 P4 was installed and in 2010 P5 was installed. (e) A 1.25 MW generator has been purchased and will be installed at Waterman as part of the 2025 High Lift Power and Pump Project. (f) Red Top Pump Station was initially installed in 1985, but was completely rebuilt in 2024. The data from the 1985 pump station is shown, since that was in place when the PUMP report was started.
(g) Although Goldridge Pump Station was installed in 2008, it wasn't started up until 2011. (h) Rancho Solano 4 Pump Station was initially installed in 1989, but was completely rebuilt in 2023. The data from the 2023 pump station is shown, since that was in place when the PUMP report was started.
(i) Rancho Solano 5 Pump Station was initially installed in 1994, but was replaced in 2019. The data from the 2019 pump station is shown, since that was in place when the PUMP report was started.
ft msl = feet mean sea level; TDH = total dynamic head; gpm = gallons per minute.

Yes Yes
No
Rancho Solano 5 RSPS5 530 1994 /
2019 (i) 200 175
No No
Sanctuary 4 SANC4 340 2002 Yes
Rancho Solano 4 RSPS4 325 1989 /
2023(h) 514 257
1,790 540
No No
Sanctuary 3 SANC3 258 2002 2,525 1,275
Yes Yes
Rancho Solano 3 RSPS3 124
Eastridge ERPS 216 2004
Yes No
1,790 1,610
2009 2,115 1,410
Yes No
No
Goldridge GRPS 112 2008(g) 4,385 3,000
No 4,200 2,800
Rolling Hills RHPS 109 1989 No No
Paradise Valley PVPS 110 1991 No No
Martin Hill MHPS 83 1998
Red Top RTPS 99 1985 /
2024(f) Yes No
Mangels MGLPS 54 1990 No No
72 2004 Yes Yes
South Cordelia SCPS 33 2005 Yes No
122 1974(d)
No
360
4,200 2,800
1988
No
Total - Zone 2A
Southbrook 2 SBPS2 110 2004 Yes Yes
Southbrook 1 SBPS1
4,200 2,800
31,400 20,900
28,000 21,000
5,700 3,800
2,600 2,150
Total - Zone 1
No(e) No
North Bay Regional
WTP
NBR 92
Waterman High Lift WTM
Table 2-5. Summary of Existing Pumping Facilities
Total - Zone 2E
Total - Zone 2D
Total - Zone 2C
Total - Zone 2B
Total - Zone 5
Total - Zone 4
Total - Zone 3B
Total - Zone 3A
Rated TDH,
feet
Horsepower
Pump No. Per Pump
Contains a
Fire Pump?
Stationary
Generator
Present?(a)
Year
Installed
Facility
Elevation,
ft msl
Facility
Pump Station Name Abbreviation
2,600 2,150
2,610 1,160
720
N-C-268-60-22-20-E-T2-T2.2-CH2
City of Fairfield
Public Utility Master Plan Page 337 of 1105 Last Revised: January 2024 Table 2-6. Summary of Existing Control Valve and Meter Vaults Valve/Meter
Vault Name
Facility
Abbreviation Valve Type
Elevation,
ft msl
Valve
Diameter,
inches Function(a)
High Service Valve HSV Butterfly Valve
(Motor Operated) 124.5 30
• Sends water from the Waterman WTP High Lift Pump Station to fill WTM. • Throttling/closing the valve diverts water from filling WTM to fill NHR and ERR (and SCR) through the West Valve.

West Distribution
Valve WV Butterfly Valve (Motor Operated) 124.5 48
• Sends water directly from the Waterman WTP High Lift Pump Station to the west side of Zone 1 (NHR, ERR, SCR).
• Closing the valve fills WTM quickly.

Crossover Valve:

Butterfly Valve
(Motor Operated)
121.4 24
• Controls water from WTM and feeds the west side of Zone 1 (into the 48- inch transmission main). Crossover is only open when Waterman WTP is offline.
• Must be open if Waterman West Valve is closed.

East Valve (EV):

Butterfly Valve
(Motor Operated)
120.9 30
• Sends water from WTM to the east side of Zone 1 to support CHR. • Functions by throttling, the less throttled (more open) the valve is, the more water that is sent to support CHR.

Hale Ranch
Valve Vault 1 HRVV1 Butterfly Valve (Motor Operated) 35.1 30 • Controls water from Waterman WTP to ERR.
• Closing prevents Waterman WTP water from reaching ERR. All water will be sent to NHR.
• Must be open when Waterman WTP is offline or Waterman West Valve is closed.

Hale Ranch
Valve Vault 2 HRVV2
Butterfly Valve
(Motor Operated)
and Check Valve

33.8 24
• Controls water from Waterman WTP to NHR.
• Closing prevents Waterman WTP water from reaching NHR. All water will be sent to ERR.
• Check valve prevents water from NHR (and NBR WTP, via the Crosstown Pipeline) from serving Anheuser-Busch.

West America
Valve Vault WAVV
Butterfly Valve
(Motor Operated)
and Check Valve

42.0 24
• Controls Water leaving ERR.
• Closing prevents ERR from supplying Zone 1. NHR would generally supply this area, if closed.
• Check valve prevents water from NHR (and NBR WTP, via the Crosstown Pipeline) from filling ERR or serving Anheuser-Busch.

Bayridge
Valve Vault BRVV
Butterfly Valve
(Motor Operated)
and Check Valve
190.0 24
• Controls Water leaving ERR.
• Closing prevents ERR from supplying Zone 1. NHR would generally supply this area, if closed.
• Check valve prevents water from NHR (and NBR WTP, via the Crosstown Pipeline) from filling ERR or serving Anheuser-Busch.

Cement Hill
Valve Vault 1 CHRV1
CHR Bypass Valve:

Butterfly Valve
(Motor Operated)

99.3 36
• When open, NBR WTP directly supplies Zone 1. Any excess supply greater than system demand is sent to CHR.
• When closed, NBR WTP fills CHR or flows through Cement Hill Valve Vault 4 to the Crosstown Pipeline.

Cement Hill
Valve Vault 2 CHRV2 Butterfly Valve (Motor Operated) 109.7 36 • Must remain open at all times.• Allows water to flow west down Manual Campos Pkwy.

Cement Hill
Valve Vault 3 CHRV3 Butterfly Valve (Motor Operated) 62.2 30 • When open, sends water to Zone 1 to the west down Cement Hill Rd.• When closed, sends water to the Crosstown Pipeline.

Cement Hill
Valve Vault 4 CHRV4 Butterfly Valve (Motor Operated) 103.1 36 • Controls flow to Crosstown Pipeline from NBR WTP.
• When open, sends water to the Crosstown Pipeline via Cement Hill Valve Vault 5.
• When closed, fills CHR or sends water through the CHR Bypass Valve to Zone 1 if bypass is open.

Cement Hill
Valve Vault 5 CHRV5 Butterfly Valve (Motor Operated) 77.4 36 • Controls flow to Crosstown Pipeline from Cement Hill Valve Vault 4. • When open (and Cement Hill Valve Vault 4 is open), sends water from NBR WTP to Zone 1. If Cement Hill Valve Vault 4 is closed, sends water from CHR to Crosstown Pipeline.
• When closed (and Cement Hill Valve Vault 4 is open), sends water from NBR WTP to Crosstown Pipeline.

Nelson Hill Bypass
Vault NHBV Butterfly Valve (Motor Operated) 26.5 30
• When open, Waterman WTP directly supplies Zone 1 and SCR. Excess water is sent to NHR.
• When closed, Waterman WTP fills NHR.
• Open from 2300 to 0300 daily.

Paradise Valley Meter
Vault PVMV Directional Flow Meter
160.6 16
• The directional flow meter is located at the Zone 2D crossing of I-80 and indicates which reservoir and pump station are primarily influencing the east side of Zone 2D.
• Monitors flow between Zone 2D areas served by Paradise Valley PS/PVR and Rolling Hill PS/RHR.

Bridge Valve Vault BVV
Source: Data is from the City's Modeling Notebook (West Yost, April 2018). (a) Reservoir facilities are noted by facility abbreviation in this table. See Table 2-4 for reservoir properties and facility abbreviation.

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Public Utility Master Plan

Table 2-7. Summary of Existing Pressure Reducing Valves Valve ID Number
(Refer to
Figure 2-5)
Pressure Reducing Valve
Name
Facility
Location
Upstream Pressure
Zone
Downstream Pressure
Zone
Elevation,
ft msl
Valve
Diameter,
inches Function
1 Peabody PRV42-1 Peabody Road Zone 1 Zone 1 85.0 16
Pressure reducer to Zone 1 off
of 42-inch diameter pipeline
2 Ellis Godfrey PRVZ-2 Ellis Godfrey Drive Zone 2 (Goldridge) Zone 1 107.0 12 Emergency use only, to reduce pressure from Zone 2 to Zone 1
3 Cement Hill PRV42-1 Cement Hill Road Zone 1 Zone 1 48.0 10 Pressure reducer to Zone 1 off
of 42-inch diameter pipeline
4 Manuel Campos PRVZ-2
Manuel Campos
Parkway /
Clay Bank Road
Zone 2 (Paradise/
Rolling Hills/
Martin Hill)
Zone 1 105.0 12 Emergency use only, to reduce
pressure from Zone 2 to Zone 1
5 Palomino PRVZ-2 Palomino Circle /
Dickson Hill Road
Zone 2 (Paradise/
Rolling Hills/
Martin Hill)
Zone 1 93.0 8 Emergency use only, to reduce
pressure from Zone 2 to Zone 1
6 East Tabor PRVCT-1 East Tabor Avenue/
Clay Bank Road Zone 1 Zone 1 43.9 10
Pressure reducer to Zone 1 off
of 36-inch diameter pipeline
7 Bear Creek PRVZ-3 Bear Creek Drive/
Penn Creek Drive
Zone 3
(Rancho/Sanctuary)
Zone 2 (Paradise/
Rolling Hills/
Martin Hill)
174.0 12 Emergency use only, to reduce
pressure from Zone 3 to Zone 2
8 Del Monte PRVZ-3 Del Monte Drive/
Pasatiempo Court
Zone 3
(Rancho/Sanctuary)
Zone 2 (Paradise/
Rolling Hills/
Martin Hill)
189.0 12 Emergency use only, to reduce
pressure from Zone 3 to Zone 2
9 Cotswold PRVZ-3 Cotswold Hill Drive Zone 3
(Rancho/Sanctuary)
Zone 2 (Paradise/
Rolling Hills/
Martin Hill)
164.0 12 Emergency use only, to reduce
pressure from Zone 3 to Zone 2
10 Oliver PRVZ-2
Oliver Road/
Waterman
Boulevard
Zone 2
(Paradise/Rolling
Hills/
Martin Hill)
Zone 1 66.0 12 Emergency use only, to reduce
pressure from Zone 2 to Zone 1
11 Pennsylvania PRVCT-1
Pennsylvania
Avenue/
Illinois Street
Zone 1 Zone 1 9.0 16
Pressure reducer to Zone 1 off
of 36-inch diameter pipeline
12 Chadbourne PRVZ-1 Chadourne Road/
Busch Drive Zone 1 Zone 1 30.0 24
Pressure reducer to Zone 1 off
of 36-inch diameter pipeline
13 Cordelia PRVCT-1 Cordelia Road/
Hale Ranch Road Zone 1 Zone 1 18.0 12
Pressure reducer to Zone 1 off
of 36-inch diameter pipeline
14 Business Center PRVZ-1 Business Center
Drive Zone 1 Zone 1 29.0 16
Pressure reducer to Zone 1 off
of 30-inch diameter pipeline
15 Bridle Ridge PRVZ-2 Bridle Ridge Drive Zone 2 (Mangels) Zone 1 87.0 10 Reduce pressure from Zone 2
(Mangels) to Zone 1 in the
event of a sudden loss of
pressure in Zone 1.
16 Spring Ridge PRVZ-2 Springridge Way Zone 2 (Mangels) Zone 1 103.0 8 Emergency use only, to reduce pressure from Zone 2 to Zone 1
17 Branding Iron PRVZ-2 Branding Iron Drive Zone 2 (Southbrook) Zone 1 87.0 6 Emergency use only, to reduce pressure from Zone 2 to Zone 1
18 SanctuarySC3 Sanctuary/Hilborn Zone 3
(Rancho/Sanctuary)
Zone 2
(Paradise/
Rolling Hills/
Martin Hill)
225.3 8 Emergency use only, to reduce
pressure from Zone 3 to Zone 2
Source: Data is from the City's Modeling Notebook (West Yost, April 2018).

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Public Utility Master Plan

Chapter 2
Existing Water System
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March 2025
Table 2-8. Summary of Existing Pipelines by Diameter
Pipeline Diameter, inch Length of Pipeline, ft Length of Pipeline, miles Percent of System 4-inch or less(a) 18,112 3.4 0.9
6 135,528 25.7 6.5
8 863,632 163.6 41.7
10 220,949 41.8 10.7
12 449,568 85.1 21.7
16 161,439 30.6 7.8
18 3,631 0.7 0.2
20 99 < 0.1 < 0.1
24 61,613 11.7 3.0
30 59,177 11.2 2.9
36 82,820 15.7 4.0
42 13,200 2.5 0.6
48 1,498 0.3 < 0.1
Total 2,071,266 392 100%
Source: The City's geographic information system (GIS) geodatabase Fairfield_Water_Utility.gdb, last updated 1/20/2023. (a) Includes some laterals that are incorrectly included in the City’s water pipeline feature class. The City is currently in the process of fixing these instances.

Table 2-9. Summary of Existing Pipelines by Material
Pipeline Material Length of Pipeline, ft Length of Pipeline, miles Percent of System Asbestos Cement Pipe (ACP) 1,449,974 274.6 70.0
Ductile Iron Pipe (DIP) 8,906 1.7 0.4
Galvanized Steel Pipe (GALV) 14 < 0.1 < 0.1
Prestressed Concrete
Pressure Pipe (PCCP) 312 < 0.1 < 0.1
Polyvinyl Chloride Pipe (PVC) 585,369 110.9 28.3
Steel Pipe
(STEEL and STEEL/CPP) 26,691 5.1 1.3
Total 2,071,266 392 100%
Source: The City's GIS geodatabase Fairfield_Water_Utility.gdb, last updated 1/20/2023. For areas where pipeline material was not recorded in the GIS based on as-built information, the material type was estimated by City staff based on the location of the pipeline and approximate construction year.

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Table 2-10. Summary of Existing Pipelines by Installation Year Pipeline Installation Year
Length of Pipeline,
ft
Length of Pipeline,
miles Percent of System
1940 to 1949 1,708 0.3 < 0.1
1950 to 1959 139,888 26.5 6.8
1960 to 1969 256,553 48.6 12.4
1970 to 1979 468,619 88.8 22.6
1980 to 1989 556,532 105.4 26.9
1990 to 1999 207,868 39.4 10.0
2000 to 2009 268,938 50.9 13.0
2010 to 2019 139,757 26.5 6.7
Newer than 2020 31,403 5.9 1.5
Total 2,071,266 392 100%
Source: The City's GIS geodatabase Fairfield_Water_Utility.gdb, last updated 1/20/2023. For areas where pipeline installation year was not recorded in the GIS based on as-built information, the installation year was estimated by City staff based on the location of the pipeline.

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Existing Water System
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Public Utility Master Plan
March 2025

2.4 REFERENCES
Kennedy Jenks. July 2021. 2020 Urban Water Management Plan.

West Yost. March 2021. Existing Conditions, Trends and Opportunities Assessment for the City of Fairfield General Plan (Draft).

West Yost. April 2018. Modeling Notebook for the Hydraulic Model Update Project – Phase 2.

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March 2025
CHAPTER 3
Water Demands
This chapter presents the City’s historical potable water use and the projected near-term (2030) and long-term (2050) potable water demands. Projected water demands were developed based on unit water use factors from the 2020 UWMP and updated future development data provided by the City’s Planning Division. The following sections of this chapter describe the data and methodology used to determine the City’s potable water system demand in the near-term and long-term planning horizons:
• Historical Water Production and Consumption
• Projected Population and Future Land Use
• Future Water Demand Projection

3.1 HISTORICAL WATER PRODUCTION AND CONSUMPTION
Under normal operations, the City’s water production consists of water treated at its two WTPs. Water consumption is defined as metered water use and is based on historical billing records provided by the City. The difference between water production and water consumption is non-revenue water (NRW):

𝑁𝑅𝑊 = 𝑊𝑎𝑡𝑒𝑟 𝑃𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 − 𝑊𝑎𝑡𝑒𝑟 𝐶𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛
The following subsections detail the City’s historical production and consumption, NRW, per capita water use, and peaking factors. This information, along with the future land use plans discussed in Section 3.2.2, serves as the foundation for future water demand projections.

3.1.1 Water Production
Table 3-1 summarizes the City’s total annual and average day water production from 2019 through 2023.

The average day production is the total annual water production divided by the total number of days in the year. Total production significantly increased in 2020 relative to other years due to the COVID-19 pandemic, which increased time spent at home for many of the City’s residents as well as irrigation water use. A gradual decline in total water production was observed between 2021 and 2023, as restrictions were lifted and businesses re-opened.

Table 3-1. Historical Water Production(a)
Calendar Year
Total Annual Production,
MG
Average Day Production,
mgd
2019 6,512 17.8
2020 7,165 19.6
2021 6,936 19.0
2022 6,870 18.8
2023 6,201 17.0
Average (2019-2023) 6,737 18.4
(a) Historical production data provided by the City in January 2023 and July 2024.

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March 2025
Figure 3-1 shows the City’s monthly water production from January 2019 through December 2023. As expected, the City’s highest water production has occurred in the summer months (June through September), when temperatures are high, and irrigation demands are at their greatest. Over this 5-year period, the lowest water production has most frequently occurred in December and March.

Figure 3-1. Historical Monthly Water Production

3.1.2 Water Consumption
Table 3-2 summarizes the City’s historical water consumption by service type from 2019 through 2023, which was developed from meter data provided by the City. Water consumption is primarily comprised of residential water use, which is nearly 60 percent of metered water use between 2019 and 2023.

Water consumption peaked in 2020 due to the COVID-19 pandemic before trending lower due to drought restrictions.

The Willotta Oaks residences are located outside the City Limits but are served by the City through a connection with the City of Vallejo. Accordingly, Table 3-2 does not account for water consumption from the Willotta Oaks residences.
200
300
400
500
600
700
800
900
1000
19-Jan
19-Mar
19-May
19-Jul
19-Sep
19-Nov
20-Jan
20-Mar
20-May
20-Jul
20-Sep
20-Nov
21-Jan
21-Mar
21-May
21-Jul
21-Sep
21-Nov
22-Jan
22-Mar
22-May
22-Jul
22-Sep
22-Nov
23-Jan
23-Mar
23-May
23-Jul
23-Sep
23-Nov
Monthly Production, MG

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Table 3-2. Historical Average Day Metered Water Consumption(a) General Service Type
Category 2019, mgd 2020, mgd 2021, mgd 2022, mgd 2023, mgd Commercial 1.24 1.15 1.19 1.19 1.11
Industrial 1.57 1.60 1.56 1.58 1.47
Public Facilities 0.33 0.30 0.32 0.30 0.30
Irrigation 3.30 3.92 3.71 3.47 3.27
Construction 0.26 0.07 0.09 0.10 0.05
Residential 9.07 10.09 9.69 9.40 8.77
Miscellaneous(b) 0.03 0.03 0.02 0.02 0.02
Total 15.8 17.2 16.6 16.1 15.0
(a) Historical metered billing data provided by the City in February 2023 and July 2024. (b) Unknown revenue class in source data (e.g., "??" and "(blank)" categorized as "Miscellaneous").

3.1.3 Non-Revenue Water
The difference between water production and water consumption is NRW, which is undesirable but difficult to eliminate entirely. The most common sources of NRW include leakage, measurement errors, and unauthorized use.

Table 3-3 summarizes the City’s historical NRW between 2019 and 2023. The City’s NRW is generally between 11 and 13 percent with a peak of 14.6 percent in 2022. The average NRW from 2019 to 2023 is approximately 12.6 percent. West Yost recommends using a NRW of 12.5 percent to calculate the City’s total future water production requirement since it is representative of recent trends.

Table 3-3. Historical Non-Revenue Water(a)
Calendar Year
Total
Production,
mgd
Total
Consumption,
mgd
Non-Revenue
Water,
mgd
Non-Revenue
Water,
%
2019 17.8 15.8 2.1 11.5
2020 19.6 17.2 2.4 12.4
2021 19.0 16.6 2.4 12.8
2022 18.8 16.1 2.8 14.6
2023 17.0 15.0 2.0 11.8
Average (2019-2023) 18.4 16.1 2.3 12.6
(a) Refer to Table 3-1 and Table 3-2.

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Public Utility Master Plan
March 2025

3.1.4 Per Capita Water Use
Per capita water use is the total annual water production divided by the population served and is typically expressed in units of gallons per capita per day (gpcd). The City’s historical per capita water use is presented in Table 3-4. As discussed above, water consumption peaked in 2020 due to the COVID-19 pandemic before trending lower due to drought restrictions.

Table 3-4. Historical Per Capita Water Use
Calendar Year Population(a)
Total Water Production(b),
mgd
Per Capita Water Use,
gpcd
2019 116,885 17.8 153
2020 119,881 19.6 163
2021 119,990 19.0 158
2022 119,395 18.8 158
2023 120,036 17.0 142
Average (2019-2023) 18.4 155
(a) Refer to Table 2-2.
(b) Refer to Table 3-1.

3.1.5 Peaking Factors
A peaking factor refers to the ratio between the peak water demands (e.g., maximum day demand, peak hour demand) and the average day demand. Water system facility evaluations and capacity requirements are based on peak demands, which are typically projected by applying a peaking factor (i.e., multiplier) to average day demand (ADD). This section describes the process of estimating the City’s recent maximum day demand (MDD) and peak hour demand (PHD) peaking factors and presents the recommended values for planning purposes. The definitions and formulas for the MDD and PHD peaking factors are as follows:
• The MDD peaking factor is calculated by dividing the year’s highest single day demand (i.e., maximum day demand) by the ADD.

𝑀𝐷𝐷 𝑃𝑒𝑎𝑘𝑖𝑛𝑔 𝐹𝑎𝑐𝑡𝑜𝑟 =
𝑀𝐷𝐷
𝐴𝐷𝐷
• The PHD peaking factor is calculated by dividing the year’s highest hour of demand within the MDD (i.e., peak hour demand) by the ADD.

𝑃𝐻𝐷 𝑃𝑒𝑎𝑘𝑖𝑛𝑔 𝐹𝑎𝑐𝑡𝑜𝑟 =
𝑃𝐻𝐷
𝐴𝐷𝐷

3.1.5.1 Systemwide Maximum Day Peaking Factors
The City’s historical systemwide MDD peaking factors between 2019 and 2023 are summarized in Table 3-5. The MDD peaking factor was highest in 2020 (1.82) and lowest in 2022 (1.50). The average MDD peaking factor over this five-year period is 1.64.

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West Yost recommends using a higher MDD peaking factor of 1.9 for planning purposes to reflect a more conservative approach for water system infrastructure planning. Adjusting the factor slightly higher than the 2020 factor provides additional conservatism for planning.

Table 3-5. Historical Systemwide Peaking Factors
Calendar Year
Average Day
Production(a), mgd
Maximum Day
Production(b), mgd
Maximum Day Demand
Peaking Factor
2019 17.8 30.5 1.71
2020 19.6 35.7 1.82
2021 19.0 30.0 1.58
2022 18.8 28.3 1.50
2023 17.0 26.8 1.58
Average (2019-2023) 18.4 30.3 1.64
(a) Refer to Table 3-1.
(b) Historical production data provided by the City in January 2023 and July 2024.

3.1.5.2 Pressure Zone- and Large User-Specific Peaking Factors – Maximum Day and Peak Hour Peaking factors can differ between pressure zones depending on the land uses that are being served. In smaller pressure zones where water use is primarily residential, the peaking factor is expected to be higher as most residences would use water at a similar time. Therefore, data collected from the Supervisory Control and Data Acquisition (SCADA) system was reviewed to determine more representative peaking factors by pressure zone. It should be noted that the PHD peaking factor is calculated by dividing the largest single hour demand by the ADD.

The recommended MDD and PHD peaking factors are summarized by pressure zone in Table 3-6. It should be noted that Anheuser-Busch does not follow the general diurnal trend associated with Zone 1 due to its large industrial water use. Therefore, a separate analysis was conducted to develop more representative MDD and PHD peaking factors for Anheuser-Busch.

Chapter 3
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3-6 City of Fairfield
Public Utility Master Plan
March 2025
Table 3-6. Recommended Peaking Factors(a)
Pressure Zone Maximum Day Peak Hour
1 1.9(b) 3.0
2 - Southbrook

2.0 5.0
2 - Mangels
2 - Paradise/Rolling Hills/Martin Hill
2 - Goldridge
3 - Eastridge
3 - Rancho/Sanctuary
2 - Red Top
4 4.0 8.0
5 Anheuser-Busch(c) 1.0 1.5
(a) Peaking factors are based on the City's 2013 historical maximum day demand diurnal pattern (July 8, 2013) and adjusted based on more recent maximum day peaking factor trends calculated from actual water use trends for each zone. (b) Based on the recommended systemwide maximum day peaking factor. (c) Although located in Zone 1, Anheuser-Busch does not follow the general diurnal trend associated with Zone 1 due to its large industrial water use.

3.2 PROJECTED POPULATION AND FUTURE LAND USE
The following subsections provides details on projected population and future land use for the City.

3.2.1 Projected Population
Population projections developed for the City’s General Plan Update (Fairfield Forward 2050) indicate that the City’s population is expected to further increase to approximately 150,000 people by 2050. Projected population totals are shown in Table 3-7 and Figure 3-2. As shown on Figure 3-2, the rate of population growth is anticipated to increase compared with the historical trend.

Table 3-7. Projected Population
Calendar Year Population
2025(a) 121,485
2030(a) 127,214
2035(a) 132,943
2040(a) 138,672
2045(a) 144,401
2050(b) 150,130
(a) Interpolated between 2024 data (120,339; Table 2-2) and 2050 population projection. (b) Source: General Plan Update Alternatives Report published in October 2021.

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Figure 3-2. Historical and Projected Population

3.2.2 Projected Future Land Use
The City is currently in the process of updating its General Plan, with the assistance of Dyett & Bhatia Urban and Regional Planners (Dyett & Bhatia), to provide a comprehensive update through 2050 that reflects the underlying conditions and the region’s evolution since the last General Plan was adopted.

West Yost staff met with the City’s Planning Division in February 2023 to discuss the status of the General Plan Update and future development projects that would impact the City’s water system. City staff, in coordination with Dyett & Bhatia, identified the following key categories for future development which are defined in more detail below:
• Active Projects & Specific Plans (e.g., Heart of Fairfield Specific Plan): these developments are more defined, and the Planning Division has some knowledge about each project • Opportunity Sites: these developments are less defined but are projected to develop over the long-term planning horizon
116,885
119,881
119,990
119,395
120,036
120,339
121,485
127,214
132,943
138,672
144,401
150,130
-
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
20192020202120222023202420252026202720282029203020312032203320342035203620372038203920402041204220432044204520462047204820492050 Population
Year
Historical
Projected
Future Projection

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At the time of preparation of this PUMP, Fairfield Forward 2050 had presented three future land use alternatives for the opportunity sites but a preferred alternative had not been selected by City Council.

Alternative 1 represents the highest potential for water-intensive industry and higher fire flow requirements and was selected for the basis of evaluations in the PUMP to provide the most conservative approach for future water system infrastructure planning.

Other possible factors that could influence future development include densification required under the Regional Housing Needs Allocation (RHNA) and local approval of accessory dwelling units (ADUs). The City confirmed that RHNA projections are accounted for within the future development projections used in the General Plan. In addition, ADUs are not anticipated to be a large part of the City’s future growth, as recent and future Single Family Residential parcels are smaller in size. Therefore, future intensification of land use due to RHNA projections and ADUs are not anticipated to constitute a significant part of the City’s future growth and are not separately accounted for in future demand projections.

Additionally, the City may integrate Travis Air Force Base into its water system in the future; however additional studies are required to further assess the resources required before service can begin.

Therefore, anticipated future demands for Travis Air Force Base (approximately 3 mgd) were not included in the near-term or long-term water demand projections.

Additional details regarding future developments are provided below.

3.2.2.1 Active Projects & Specific Plans
Active projects can be at various stages of development (concept, permit, design, etc.) and are specific development projects that the Planning Division has knowledge of. A Specific Plan provides a comprehensive and precise set of guidelines, regulations, and design principles to guide future development in a particular area. Specific Plans also tend to cover a larger development area than active projects.

Table 3-8 summarizes the current active projects, Specific Plans, and other anticipated development projects including the projected dwelling units, building areas, and timing for each project. These projects will add 4,210 dwelling units to the to the City’s housing stock by 2030, and a total of 8,549 dwelling units by 2050. In line with the City’s existing land use market trends, the vast majority of these new units will be low-and medium-density residential homes. Approximately 3.6 million square feet of building area for Commercial and Industrial land uses is also projected. Locations of major active projects are shown on Figure 2-6 of the Fairfield Forward 2050 Alternatives Report.1 1 City of Fairfield General Plan Update: Fairfield Forward 2050 (October 2021)

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Last Revised: March 2025
Table 3-8. Active Development Projects and Specific Plans(a) Project Name Address or Location Development Type
General Plan Lan Use
Designation
Total Projected
Development Units
Estimate of
Timing
Residential
Bella Vita Phase II Via De Bella Single-family
(Low-Medium) Residential–Medium 13 DU 2030
Cooper’s Landing Cement Hill Road Single-family (Low) Residential–Low 169 DU 2030 Estaire Pittman Road at
Link Road Mixed-use Residential–High 25 DU 2030
Fieldcrest Red Top Road Single-family Residential–Low 394 DU 2050 Hawthorne Mill Cement Hill Road and
Peabody Road Single-family Residential–Low 550 DU 2050
Villas at Havenhill Red Top Road Multi-family Residential–Medium 324 DU 2050 Gold Hill Village III Gold Hill Road at Lopes
Road
Single-family
(Low-medium) Residential–Medium 79 DU 2030
Train Station
Specific Plan -
Single and Multi-family
(high = 39.5%, medium =

35.2%, low = 25.2%)
Residential–Low
Residential–Medium
Residential–High
3,527 DU 50% by 2030
Heart of Fairfield
Specific Plan -
Single and Multi-family
(medium = 45.5%,
high = 54.5%)
Residential–Medium
Residential-High 1,600 DU 50% by 2030
Eastridge Green Valley Road Single-family (Low) Residential–Low 15 DU 2030 Enclave at Red Top Red Top Road Single-family (Medium) Residential–Medium 65 DU 2030 Gardenstone at
Tabor Avenue
Gardenstone Place at
Tabor Avenue Single-family Residential–Low 10 DU 2050
Gold Hill Village II Red Top Road at
Lopes Road Single-family Residential–Low 6 DU 2050
Green Valley II Business Center Drive/
Suisun Valley Road Multifamily Residential–Very High 281 DU 2050 Ivy Crossing E Tabor Avenue Single-family (Medium) Residential–Medium 111 DU 2030 Village Oaks Suisun Valley Road Single-family (Medium) Residential–Medium 10 DU 2030 Villages at Fairfield Gulf Drive at Clay
Bank Road
Single-family
(Low-Medium) Residential–Medium 1048 DU 2030
Middle Green Valley(c)- - Residential–Low 322 DU 112 DU by 2030 Subtotal (2030) 4,210 DU -
Subtotal (2050) 4,339 DU -
Total 8,549 DU -
Non-Residential
CB Lining Contractors
Yard 780 Link Road Industrial General Industrial 21,500(b) ft2 2030 Float Glass and Mirror 2600 Industrial Drive Industrial General Industrial 15,000 ft2 2030 Innova Chadbourne 510 Chadbourne Road Industrial General Industrial 432,500 ft2 2030 Huntington and Air Base Huntington Drive Industrial General Industrial 497,000 ft2 2030 Gateway 80 Building C 2950 Cordelia Road Office/Industrial Business and Industrial Park 356,000 ft2 2030
PDC Building A Business Center Drive Industrial General Industrial 162,000 ft2 2030 PDC Buildings B & C Business Center Drive Industrial General Industrial 219,400 ft2 2030 Storage 360 1245 Horizon Drive Storage facility Commercial – Service 70,000 ft2 2030 Pittman Road Self Storage 555 Pittman Road Storage facility Commercial – Service 114,000 ft2 2030 Fairfield Toyota
Expansion 2575 Auto Mall Parkway Car dealership Commercial – Service 13,500 ft2 2030 Nippon Industrial
Expansion 2340 S Watney Way Industrial General Industrial 10,200 ft 2 2030
Storage Pro Lopes Road Storage facility Commercial – Service 137,000 ft2 2030 Train Station Specific Plan - Various Mixed Use 1,289,000 ft2 50% by 2030 Heart of Fairfield
Specific Plan - Various Mixed Use 140,000 ft2 50% by 2030 Middle Green Valley(c)- - Commercial – Community 93,000(d) ft2 2050 Subtotal (2030) 2,762,600 ft2-
Subtotal (2050) 807,500 ft2-
Total 3,570,100 ft2-
(a) Based on data provided by the City’s Planning Division in May 2023. (b) Estimated using the floor-area-ratio for General Industrial land use. (c) Based on Tentative Subdivision Map provided by City staff in February 2023. Although the supply to serve this development will not come from the City’s water supply portfolio, water will be delivered through a treat and wheel agreement, and service will be provided by Solano Irrigation District. (d) Estimated using the floor-area-ratio for Commercial - Community land use.

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More specifically, the Train Station Specific Plan (TSSP), Middle Green Valley Specific Plan2(MGVSP), and the Heart of Fairfield Specific Plan (HOFSP) will add housing capacity in Northeast Fairfield, Green Valley, and Downtown Fairfield, respectively. The TSSP, which covers a portion of Northeast Fairfield close to Travis Air Force Base, has capacity for over 3,500 new dwelling units in addition to the housing units that are already underway within the Specific Plan area. Approximately 44 percent of those new dwelling units in the TSSP are intended for single family homes. The MGVSP has capacity for 322 new units – all of which are intended for single family homes. The HOFSP, which applies to Downtown Fairfield along the West Texas Street and Texas Street corridors, includes capacity for 1,600 additional dwelling units.

3.2.2.2 Opportunity Sites
According to Fairfield Forward 2050 Alternatives Report (October 2021), opportunity sites are those that have the greatest potential for land use or intensity change over the long-term planning horizon. Sites were identified as potential opportunity sites if they fell under one or more of the following three categories: vacant lots, a low improvements to land assessed value ratio, or low floor area ratio. As discussed above, Alternative 1 represents the highest potential for water-intensive industry and would require higher fire flow requirements and was selected for the basis of evaluations in the PUMP. The opportunity site land use projection for Alternative 1 is summarized in Table 3-9. Figure 3-3 shows the location of opportunity sites including the proposed land use under Alternative 1.

Based on input from Dyett & Bhatia on the data they provided, this PUMP conservatively assumes that potential future development at opportunity sites is entirely new development (adding to existing use) and not redevelopment.
2 Data based on a Tentative Subdivision Map provided by City staff in February 2023. Although the supply to serve this development will not come from the City’s water supply portfolio, water will be delivered through a treat and wheel agreement, and service will be provided by Solano Irrigation District.

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Table 3-9. Summary of Opportunity Site Land Use Projections: Alternative 1(a) General Plan Land Use Designation Proposed Development Units Residential(b,c)
Residential - Low Density 3,115 DU
Residential - Medium Density 4 DU
Residential - High Density 691 DU
Residential - Very High Density 156 DU
Total - Residential 3,966 DU
Non-Residential(d,e,f)
Commercial - Office 3,078,443 ft2
Commercial - Service 1,987,523 ft2
General Industrial 6,260,679 ft2
Total - Non-Residential 11,326,645 ft2
(a) Data received from Dyett & Bhatia in March 2023.
(b) Single family dwelling units were assigned a land use designation of "Residential - Low Density". (c) The Alternative 1 land use field was used to determine the density of multi-family residential units. Mixed Use land use was assumed to consist of “Residential - Very High Density” for the multi-family residential dwelling unit component. (d) Office building area was assigned a land use designation of "Commercial - Office". (e) Retail and hotel building area was assigned a land use designation of "Commercial - Service". (f) Industrial building area was assigned a land use designation of "General Industrial".

Abbreviations: DU = Dwelling Units, ft = feet

Notes:

1. The Mixed Use land use contains
Residential - Very High Density
dwelling units along with some
Commercial and Industrial building areas.

2. Source: Data received from Dyett &
Bhatia in March 2023.

3. Striped areas indicate multiple land uses
are projected. The colors of the stripes
represent the projected land uses.
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§¨¦80
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Figure 3-3
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80 Cordelia
Dixon
Fairfield
Martinez
Napa
Vacaville
Vallejo
0 3 6
Kilometers
0 2 4
Miles
City of Fairfield
Public Utility Master Plan
Alternative 1
Opportunity Sites
Existing City Limits
Alternative 1 Land Use
Residential - Low Density
Residential - Medium Density
Residential - High Density
Mixed Use
Commercial - Office
Commercial - Service
General Industrial
Multiple Land Uses (see Note 3)
Cordelia
Suisun City
Travis Air Force Base
Suisun Slough

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3.3 FUTURE WATER DEMAND PROJECTION
This section reviews the methodology used to project the City’s future water demands. Water demand projections are presented for near-term (2030) and long-term (2050) planning periods and compared with the demand projections adopted in the 2020 UWMP.

3.3.1 Land Use-Based Demand Projections
Because population-based water demand projections are based solely on population data, they do not account for changes in water use due to variations in different land use types and spatial locations.

Therefore, population-based water demand projections are useful for estimating overall water demand, but water demands developed using land use data are preferred for water system planning and hydraulic modeling. Future water demands are typically allocated to the water system hydraulic model based on the actual location of future development. To be conservative for infrastructure planning, the land use-based demand projections do not account for reduction in water use that may occur as a direct result of water conservation.

3.3.1.1 Demand Projection Methodology
Future water demands were developed by adding projected future demands (due to new development) to existing baseline water demands. To provide a more conservative water demand projection, the existing baseline water use was assumed to equal the highest water production recorded in the past five years (19.6 mgd in 2020). Although water use in 2020 was higher due to the COVID-19 pandemic, it was an actual amount that had to be served from the City’s water distribution system.

Future demands are projected based on land use units that are directly correlated with water use. These units vary by land use and are based on either area (e.g., building square footage) or dwelling units.

Water demands are projected for a given development by multiplying the number of units by the corresponding unit water use factor.

3.3.1.2 Unit Water Use Factors
A unit water use factor is defined as the estimated amount of water usage per area for a particular land use type (i.e., gallons per day per acre [gpd/acre]). The City’s unit water use factors were developed by Kennedy/Jenks based on historical consumption data for the 2020 UWMP and were directly used in this PUMP to project future water demands. Unit water use factors were converted from acreage to:
(1) building square feet (ft2) based on the planned floor area ratio (FAR); and (2) dwelling units based on the planned residential density. Table 3-10 summarizes the unit water use factors used for each General Plan land use designation that was present in the planning data provided by the City’s Planning Division.

3.3.1.3 Water Demand Projection
Based on potential new development (Tables 3-8 and 3-9) and recommended unit water use factors (Table 3-10), Table 3-11 calculates the additional water demand for the near- and long-term planning periods. Additional near-term (i.e., by 2030) demand is approximately 4.20 mgd, while additional long-term (i.e., between 2031-2050) demand is approximately 9.40 mgd. With an existing baseline demand of 19.6 mgd (peak water production between 2019-2023), the total near-term water production required is estimated at approximately 23.8 mgd, while the total long-term water production required is estimated at approximately 29.0 mgd.

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Table 3-10. Water Use Factors Summary(a)
General Land Use Type General Plan Land Use Designation Water Use
Factor,
gpd/acre
Residential
Density,
DU/acre
(b)
Residential
Water Use
Factor,
gpd/DU
Non-Residential
Floor Area Ratio
Non-Residential
Water Use
Factor, gpd/ft2
Commercial
Commercial - Office
1,890
- - 0.25 0.17
Commercial - Community
- - 0.30 0.14
Commercial - Service
Industrial
Business and Industrial Park
1,280 - - 0.30 0.10
General Industrial
Mixed Use Mixed Use 1,300 Variable(c) Variable(c) 0.30 0.10 Single Family Residential Residential - Low Density 1,801 4 450 - - Multi-Family Residential
Residential - Medium Density
3,651
10 365 - -
Residential - High Density 18 203 - -
Residential - Very High Density 28 130 - -
(a) Based on the unit water demand factors used for the 2020 Urban Water Management Plan prepared by Kennedy Jenks. (b) Residential density and Floor Area Ratio (FAR) values based on data received from Dyett & Bhatia in March 2023. (c) Varies based on residential land use designation provided.

DU = Dwelling Unit

Dwelling Units Building Area, ft2
Average Day
Demand, mgd Dwelling Units Building Area, ft2
Average Day
Demand, mgd
Active Pipeline Projects
Commercial - Service 0.14 gpd/ft2 - 334,500 0.05 - - -
Business and Industrial Park 0.10 gpd/ft2 - 356,000 0.04 - - - General Industrial 0.10 gpd/ft2 - 1,357,600 0.14 - - -
Residential - Low Density 450 gpd/DU 184 - 0.08 960 - 0.43 Residential - Medium Density 365 gpd/DU 1,326 - 0.48 324 - 0.12 Residential - High Density 203 gpd/DU 25 - 0.01 - - -
Residential - Very High Density 130 gpd/DU - - - 281 - 0.04 1,535 2,048,100 0.79 1,565 - 0.59
Heart of Fairfield Specific Plan
Mixed Use 0.10 gpd/ft2 - 70,000 0.01 - 70,000 0.007
Residential - Medium Density 365 gpd/DU 364 - 0.13 364 - 0.13 Residential - High Density 203 gpd/DU 436 - 0.09 436 - 0.09 800 70,000 0.23 800 70,000 0.23
Middle Green Valley Project
Commercial - Community 0.17 gpd/ft2 - - - - 93,000 0.02 Residential - Low Density 450 gpd/DU 112 - 0.05 210 - 0.09 112 - 0.05 210 93,000 0.11
Train Station Specific Plan
Mixed Use 0.10 gpd/ft2 - 644,500 0.06 - 644,500 0.06
Residential - Low Density 450 gpd/DU 444 - 0.20 444 - 0.20 Residential - Medium Density 365 gpd/DU 621 - 0.23 621 - 0.23 Residential - High Density 203 gpd/DU 698 - 0.14 698 - 0.14 1,763 644,500 0.63 1,764 644,500 0.63
Opportunity Sites
Commercial - Office 0.17 gpd/ft2 - - - - 3,078,443 0.52 Commercial - Service 0.14 gpd/ft2 - - - - 1,987,523 0.28 General Industrial 0.10 gpd/ft2 - - - - 6,260,679 0.63
Residential - Low Density 450 gpd/DU - - - 3,115 - 1.40 Residential - Medium Density 365 gpd/DU - - - 4 - 0.001 Residential - High Density 203 gpd/DU - - - 691 - 0.14
Residential - Very High Density 130 gpd/DU - - - 156 - 0.02 - - - 3,966 11,326,645 2.99
Miscellaneous Development
Anheuser-Busch(c) - - 2.26 -
- - 2.26 -

3.96 4.55

0.24 0.65

4.2 9.4

19.6 19.6

23.8 29.0
New Water Production Required
Existing (2020) Water Production
Total Water Production Required
Table 3-11. Land Use Based Water Demand Projection for Alternative 1(a) (a) Dwelling units and building area based on values presented in Tables 3-8 and 3-9. (b) Based on the unit water use factors used for the 2020 UWMP prepared by Kennedy Jenks. Refer to Table 3-10. (c) Future water use projection for Anheuser-Busch is based on the maximum contracted amount of 3.1 mgd. (d) NRW not applied for the Miscellaneous Development category.

Near-Term (2030)
Subtotal
Total New Demand
NRW (12.5%)(d)
Long-Term (2050)
Subtotal
General Plan Land Use Designation
Subtotal
Subtotal
Subtotal
Subtotal
Water Use Factor(b) Water Use Factor Units
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The near-term (2030) water production increase is approximately 21 percent higher than existing baseline (2020) water production (a growth rate of approximately 2 percent per year), and the long-term (2050) water production is 48 percent higher than the existing baseline water production (a growth rate of approximately 1 percent per year). It should be noted that although the historical average water use from Anheuser-Busch is 1.0 mgd, these water demand projections include approximately 2.3 mgd of additional water demand to conservatively assume that Anheuser-Busch will utilize its full contract amount by 2030 and beyond. This additional water demand from Anheuser-Busch is equal to approximately 55 percent of new demands in the near-term planning period and 24 percent of new demands in the long-term planning period.

This PUMP also conservatively assumes that potential future development (i.e., active projects and opportunity sites) is new development and not redevelopment.3 Therefore, future water demands are added to existing water use (if any) at the locations identified for potential future development.

3.3.2 Comparison with 2020 Urban Water Management Plan
Table 3-12 compares the near-term (2030) and long-term (2050) demand projections between this PUMP and the City’s 2020 UWMP. When compared using the projected year, the 2020 UWMP projections are lower than the projections developed for this PUMP because they assume a slower growth rate. For buildout, the 2020 UWMP projects a required water production of 32.9 mgd by 2078 while this PUMP conservatively assumes a faster growth rate with a buildout required water production of 29.0 mgd by 2050 for infrastructure planning.

Although the buildout required water production in this PUMP is approximately 12 percent lower than the 2020 UWMP total, a comparison of the projected per capita water use between the two different reports indicate that the projected per capita water use trends are similar if the additional demand from Anheuser-Busch is excluded from the PUMP projections.

Table 3-12. Comparison of Required Water Production
Projected
Year
Report
Name
Basis of
Projection
Projected Water
Production
Required, MG
Projected Water
Production
Required, mgd
Per Capita
Water Use(a),
gpcd
2030 2020 UWMP(b)Land Use 7,647 21.0 175
2030 2023 PUMP(c)
Land Use:

Alternative 1 8,680 23.8 187 / 169
(d)
2045 2020 UWMP(b)Land Use 8,275 22.7 176
2050 2023 PUMP(c)
Land Use:

Alternative 1
10,578 29.0 193 / 178(d)
(a) Refer to Table 3-7 for PUMP population projections; refer to Table 1-7 of the 2020 UWMP for UWMP population projections. (b) Refer to Table 2-5 in the 2020 UWMP.
(c) Refer to Table 3-11.
(d) Assumes the historical average water use rate of 1.0 mgd for Anheuser-Busch (i.e., does not include additional 2.3 mgd of projected water demand).
3 Based on input from Dyett & Bhatia on the data provided for the opportunity sites.

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It should be noted that the 2020 UWMP assumes a recycled water demand of approximately 0.2 mgd in 2040 and beyond. However, to provide a more conservative water system evaluation for planning purposes, this additional projected recycled water use is not subtracted from the long-term potable water demand projections.

3.3.3 Recommended Future Water Demand Projection
It is recommended that the City adopt the most recent land use-based water demand projection developed for this PUMP because it incorporates more recent and accurate future development estimates from the Fairfield Forward 2050 Alternatives Report (October 2021). Although this projected buildout water production is lower than the 2020 UWMP projection, the projected growth rate for this PUMP is already significantly higher than the historical growth, as shown on Figure 3-4, and should be conservative for planning purposes. Using the most recent development estimates also provides confidence that the projections developed for this PUMP should more accurately represent future growth compared to the 2020 UWMP, which used older development estimates. In addition, the land use-based water demand projections developed for this PUMP are spatially located and will streamline the hydraulic evaluation of the City’s future water system. The recommended near-term and long-term water production are summarized in Table 3-13. The existing water production is also included in Table 3-13 for comparison purposes.

Figure 3-4. Recommended Future Water Production

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Table 3-13. Summary of Recommended Future Water Production(a) Planning Period Total Annual Production, MG Average Day Production, mgd Existing (2020) 7,165 19.6
Near-Term (2030) 8,680 23.8
Long-Term (2050) 10,578 29.0
(a) Refer to Table 3-12.

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3.4 REFERENCES
Dyett & Bhatia. October 2021. Fairfield Forward 2050: Alternatives Report.

Kennedy Jenks. July 2021. 2020 Urban Water Management Plan.

West Yost. March 2021. Existing Conditions, Trends and Opportunities Assessment for the City of Fairfield General Plan (Draft).

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CHAPTER 4
Water System Regulatory Review and Policy Updates
This chapter describes the evaluation of current and upcoming water system regulations and policies. It also describes recommendations for modifications to the City’s facilities and municipal code to comply with the current and anticipated regulatory requirements.

A regulatory review is a key component of water system master planning, as revisions or additions to regulations and policies (e.g., lowering of constituent maximum contaminant levels, the addition of a new regulated constituent, etc.) can require major changes to water treatment plant processes and associated costs can be substantial. As such, foresight to upcoming water system regulations and policies is important for City budgeting and planning.

The following sections of this chapter describe the findings and recommendations from the water system regulations and policies evaluation:
• Water System Regulatory Review
• Municipal Code (Chapter 22) Review

4.1 WATER SYSTEM REGULATORY REVIEW
West Yost has reviewed the current drinking water regulations published by the United States Environmental Protection Agency (EPA) and adopted by the State of California (State), as well as the regulations included in the California Code of Regulations (CCR) sections for drinking water systems. The State Water Resources Control Board (SWRCB) Division of Drinking Water (DDW) has primacy for monitoring and enforcing drinking water regulations and has implemented minor additions and water treatment performance objectives that are not included in the EPA’s (Federal) rules and regulations.

Additionally, West Yost has reviewed the statewide National Pollutant Discharge Elimination System (NPDES) permit for drinking water system discharges to waters of the United States and the Bay Area Air Quality Management District permits for the operation of ozone generators and standby emergency generators. Regulations applicable to the City’s water system are identified in the following sections, including anticipated changes, status of compliance, and recommendations to achieve compliance.

4.1.1 Drinking Water Regulations

4.1.1.1 Federal Regulations
The City is currently in compliance with all existing Federal drinking water regulations. The current and anticipated applicable Federal drinking water regulations are summarized in Table 4-1. Revisions to existing regulations and new regulations that are currently anticipated include:
• Stage Three Disinfectants and Disinfection Byproducts Rules (D/DBPR) – The EPA is contemplating a revision to the Disinfection Byproduct Rules. While at this time it is unknown what a revision might entail, it is possible that changes could include increasing total organic carbon (TOC) removal requirements, developing more stringent standards for both total trihalomethane (TTHM) and five haloacetic acids (HAA5) with lower maximum contaminant levels (MCL), establishing an MCL for all nine of the chlorinated and brominated haloacetic acids (HAA9), and/or establishing MCLs for specific disinfection byproduct TTHM species. Since the City’s water supply is entirely surface water, and surface waters typically have higher TOCs compared to groundwater, the impacts from these potential regulation changes could be significant. The City should track the evolution of the Stage 3 D/DBPR development, the

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concentrations of individual TTHM and HAA9 species, and consider expanding disinfection byproduct sampling to improve its understanding of the anticipated Stage 3 D/DBPR’s impacts based on current disinfection byproducts speciation within the distribution system. • Revised Lead and Copper Rule (LCR) – Revisions to the Lead and Copper Rule, identified by the EPA as the Lead and Copper Rule Improvements (LCRI), are anticipated to be finalized by October 16, 2024. The revisions require the replacement of all lead service lines and service line components, including “lead pigtails,” and prioritizing replacement within historically underserved communities, strengthening compliance tap sampling requirements, and revising action and trigger levels. To date, the City has not identified lead service lines or components, including “lead pigtails,” within the City’s distribution system. If components are identified in the future, the City should replace the leaded components (including any galvanized) with lead-free materials. Additionally, since increased sampling is anticipated, the City should prepare to implement additional compliance tap sampling to meet future sampling requirements once the requirements are known. The City is currently on a reduced triennial lead and copper tap monitoring schedule and is required to collect 50 residential tap samples during the warmest months between June 1 and September 30. The latest sampling event took place in 2023 and the City is in compliance with the LCR by not exceeding the 90th percentile of action levels of 0.015 milligrams per liter (mg/L) and 1.3 mg/L for lead and copper, respectively. The next triennial sampling event will occur in 2026. • Polyfluoroalkyl substances (PFAS) Regulations – New federal regulationsfor PFAS were announced on April 10, 2024 with the EPA’s Final PFAS National Primary Drinking Water Regulation. The final rule establishes legally-enforceable MCLs for six per- and PFAS in drinking water. It requires that public water systems monitor for these six PFAS, with initial monitoring complete by 2027. The rule also requires providing the public with information on the levels of these PFAS in their drinking water by 2027. By 2029, public water systems need to have implemented solutions to reduce PFAS levelsif MCLs are exceeded so that compliance is met.

Treatment process improvements could include replacing granular activated carbon (GAC) filter media more frequently.
• Manganese – Manganese is one of the 15 contaminants included in the EPA's National Secondary Drinking Water Regulations (NSDWRs), which are non-mandatory water quality standards. EPA does not enforce these "secondary maximum contaminant levels" (SMCLs). They are established as guidelines to assist public water systems in managing their drinking water for aesthetic considerations, such as taste, color, and odor. The SMCL for manganese is 0.05 mg/L. For reference, treated water samples from the City’s water treatment plants over the past 10 years have typically ranged between non-detect and 0.02 mg/L. Manganese was included as part of the Fourth Unregulated Contaminant Monitoring Rule (UCMR 4); however, no primary MCL was established. EPA indicated that development of an updated health assessment for manganese is ongoing, however no schedule for public review has been released. It is possible that the updated health assessment could trigger the establishment of a manganese primary MCL. • Consumer Confidence Report Rule Revisions – The EPA has proposed revisions to the Consumer Confidence Report Rule. The intent of the proposed revisions is to improve clarity of communicating the water quality information reported in the Consumer Confidence Report and enhance accessibility to the information for consumers. The revised rule also increases the frequency at which Consumer Confidence Reports are to be issued, from once annually to twice annually for systems serving 10,000 users or more.

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Table 4-1. Federal Regulations
Regulation Status Regulation Summary Compliance Recommendation Impacted Process or System Current Regulations
Surface Water Treatment Rules (SWTR, IESWTR,
LT1ESWTR, LT2ESWTR, Filter Backwash
Recycling Rule)
Current Regulation -
In Compliance
• The purpose of the Surface Water Treatment Rules (SWTRs) is to reduce illnesses caused by pathogens in drinking water. The SWTRs require water systems to filter and disinfect surface water sources. • The Waterman and NBR WTPs appear to be in compliance with the relevant provisions of the SWTR, including Disinfection Credit, Filter Turbidity, and DBPs (THMs, HAAs, Bromate). Compliance with additional State-specific provisions within the SWTR for California, such as the Cryptosporidium Action Plan, is further discussed in State Regulations (refer to Table 4-2).

Sedimentation Basins, Filters,
Disinfection System, Distribution
System
Total Coliform Rule Current Regulation -
In Compliance
• The Total Coliform Rule (TCR), a national Primary Drinking Water Regulation, was published in 1989 and became effective in 1990. The rule set both a health goal (Maximum Contaminant Level Goal (MCLG)) and legal limits (Maximum Contaminant Levels (MCLs)) for the presence of total coliforms in drinking water. EPA set the MCLG for total coliforms at zero. • The rule requires all public water systems to monitor for the presence of total coliforms in the distribution system at a frequency proportional to the number of people served.
• The City is in compliance with this regulation and collects bacteriological samples in accordance with the Bacteriological Sample Siting Plan approved by DDW.

Treatment Plants and Distribution
System
Revised Total Coliform Rule Current Regulation -
In Compliance
• The EPA published the Revised Total Coliform Rule (RTCR) in 2013. The RTCR establishes a MCL for E. coli and uses E. coli and total coliforms to initiate a “find and fix” approach to address fecal contamination that could enter the distribution system. It requires public water systems to perform assessments to identify sanitary defects and subsequently take action to correct them. There are two levels of assessments (Level 1 and Level 2) based on the severity or frequency of the coliform contamination. • Water systems must develop a written sample siting plan that identifies the system’s sample collection schedule and all sample sites, including sites for routine and repeat monitoring.
• The City is in compliance with this regulation and collects bacteriological samples in accordance with the Bacteriological Sample Siting Plan approved by DDW.

Treatment Plants and Distribution
System
Lead and Copper Rule Current Regulation -
In Compliance
• In 1991, EPA published a regulation to control lead and copper in drinking water. This regulation is known as the Lead and Copper Rule (LCR). • The treatment technique for the rule requires systems to monitor drinking water at customer taps. If lead concentrations exceed an action level of 15 ppb or copper concentrations exceed an action level of

1.3 ppm in more than 10% of customer taps sampled, the system must undertake additional actions to control corrosion.
• The City is currently on a reduced triennial lead and copper tap monitoring schedule and is required to collect 30 residential tap samples during the warmest months between June 1 and September 30. The latest sampling event took place in 2020 and the City is in compliance with the LCR by not exceeding the 90th percentile of action levels of 0.015 mg/L and 1.3 mg/L for lead and copper, respectively. The next triennial sampling event will occur in 2023.

Distribution System
Manganese Current Regulation -
In Compliance
• Manganese is one of the 15 contaminants included in the EPA's National Secondary Drinking Water Regulations (NSDWRs), which are nonmandatory water quality standards. EPA does not enforce these "secondary maximum contaminant levels" (SMCLs). They are established as guidelines to assist public water systems in managing their drinking water for aesthetic considerations, such as taste, color, and odor. The SMCL for manganese is 0.05 mg/L. See State level regulations for SMCL enforcement (refer to Table 4-2).
• When manganese is present in drinking water at levels above the SMCL, it may cause black or brown appearance, black staining, or a bitter metallic taste.
• Compliance with additional State-specific provisions is further discussed in State Regulations (refer to Table 4-2). Treatment technologies are available and can be considered as necessary.

Raw Water Intake and Filtration
System

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Table 4-1. Federal Regulations
Regulation Status Regulation Summary Compliance Recommendation Impacted Process or System Cyanotoxins/Harmful Algal Blooms Current Guidance
• Cyanotoxins were included in the Fourth Unregulated Contaminant Monitoring Rule (UCMR 4). The EPA publishes Health Advisories for unregulated contaminants that guide water systems in certain situations but are not federally enforceable.
• The EPA has developed two distinct Health Advisories for the cyanotoxins microcystins and cylindrospermopsin for two population groups. The 10- day health advisories for sensitive populations (i.e., infants, elderly, pregnant mothers, etc.) are 0.3 ppb for microcystins, and 0.7 ppb for cylindrospermopsin. For the general adult population, the 10-day health advisories are 1.6 ppb for microcystins, and 3.0 ppb for cylindrospermopsin.
• The City should consider monitoring for these cyanotoxins in the source water and treated water, particularly during times when the algae species may be present in untreated source water, such as during the spring and summer months. Note that treatment processes may release cyanotoxins from algae cells due to lysing of the cells; therefore, absence of cyanotoxins in untreated source water does not necessarily mean that cyanotoxins will be absent from treated water.

Raw Water and Entry Point to the
Distribution System
Radionuclides Current Regulation -
In Compliance
• The Radionuclides Final Rule set new monitoring requirements for community water systems to ensure customers receive water in compliance with the MCLs for radionuclides in drinking water. • Four groups of radionuclides are regulated contaminants with MCLs (4 mrem/yr for beta/photon emitters, 15 pCi/L for gross alpha particle, 5 pCi/L for combined radium-226/228, and 30 ppb for uranium). • Most community water systems do not require monitoring, but "vulnerable community water systems" must sample quarterly and annually. The City's initial monitoring of radionuclides in 2011 dictated the subsequent reduced monitoring frequency. If at any time samples exceed the MCL, increased monitoring is triggered, and the City would be required to return to quarterly monitoring until four consecutive quarterly samples are below the MCL.

Radionuclide monitoring data from the last 10 years for the North Bay Aqueduct and Putah South Canal do not exceed the MCLs for radionuclides identified.

Raw Water Intake
Unregulated Contaminant Monitoring Rule Current Regulation - In Compliance
• The Safe Drinking Water Act (SDWA) requires that once every five years EPA issue a list of unregulated contaminants to be monitored by public water systems.
• The most recent list is the fifth Unregulated Contaminant Monitoring Rule (UCMR 5), which was published on December 27, 2021. UCMR 5 specifies monitoring for 29 per- and polyfluoroalkyl substances (PFAS) and lithium.
• Public water systems with more than 10,000 customers are required to participate in the UCMR testing.
• The City completed the UCM5 monitoring requirement in 2024 for the monitoring period of January 2024 through December 2024.

Varies
Anticipated Regulations and Revisions
Polyfluoroalkyl Substances (PFAS)
New Regulation
(as of April 10, 2024)
- initial monitoring
by 2027, compliance
by 2029
• EPA established MCLs for six PFAS chemicals: PFOA 4.0 ppt, PFOS 4.0 ppt, PFHxS 10 ppt, PFNA 10 ppt, HFPO-DA (GenX) 10 ppt, and PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS using a Hazard Index MCL of 1 (unitless) to account for the combined and co-occurring levels of these PFAS in drinking water.
• The City should begin monitoring for a minimum of these six PFAS chemicals to establish a baseline concentration for these constituents, and to comply with the initial monitoring requirements established in the final rule by 2027.
• Water systems with regulated PFAS levels above the established MCLs will be required to install treatment or take other action to reduce regulated PFAS levels in their drinking water for compliance by 2029.

Raw Water, Settled Water, and
Treated Water
Potential Revisions to Microbial and Disinfection
Byproduct Rules
Current Regulation -
In Compliance
Currently under
revision
• The EPA's third "Six-Year Review" identified eight national primary drinking water regulations (NPDWRs) as candidates for revision, including: Chlorite, Cryptosporidium, Haloacetic acids, heterotrophic bacteria, Giardia lamblia, Legionella, Total Trihalomethanes, and viruses. • EPA is currently conducting analyses to further evaluate the eight NPDWRs for potential regulatory revisions. EPA is also evaluating information on unregulated DBPs, including chlorate and nitrosamines.

There is discussion of these revisions potentially leading into Stage 3 Disinfection Byproduct rules, as HAAs might be expanded from HAA5 to HAA9. Water system managers should stay informed until regulatory decisions are made.
• The City should consider starting to compile and track speciation of DBPs, particularly the more brominated forms of THMs and HAAs, as monitoring may be required in the future. This would also call attention to any species that might have particularly high concentrations that could heavily influence total concentrations.

Disinfection System and
Distribution System

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Table 4-1. Federal Regulations
Regulation Status Regulation Summary Compliance Recommendation Impacted Process or System Contaminant Candidate List
Current Regulation -
In Compliance
Anticipated updates
in late 2026
• The Contaminant Candidate List (CCL) is a list of contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations but are known or anticipated to occur in public water systems. Contaminants listed on the CCL may require future regulation under the Safe Drinking Water Act.
• EPA is beginning the development of the Sixth Contaminant Candidate List (CCL 6). EPA is also examining relevant research studies and gathering additional data to prioritize CCL 5 contaminants. EPA is required by law to make regulatory determinations on at least five contaminants for Regulatory Determination 5.
• The City should stay informed as regulatory determinations are made for these in-progress CCLs, and also become familiar with recent Regulatory Determinations, including PFAS and PFOA, from the most recent Regulatory Determination (Regulatory Determination 4). Regulatory Determination 5 is still in progress, and CCL 6 is still in draft form.
• The City should also consider sampling and monitoring (per CCL established sampling intervals) for the new contaminants on the more recent CCL lists, such as CCL 5 which includes 81 contaminants or contaminant groups of chemicals, cyanotoxins, disinfection byproducts (DBPs), PFAS chemicals, and microbes.

Varies
Revised Lead and Copper Rule
Current Regulation -
In Compliance
Revisions anticipated
in October 2024
• Focus areas for the proposed rulemaking include: 1) replacing all lead service lines, 2) compliance tap sampling, 3) action and trigger levels, and 4) prioritizing historically underserved communities.
• Revisions will be part of the proposed Lead and Copper Rule Improvements (LCRI), which is anticipated to be finalized by October 16, 2024.
• Follow EPA guidance on how to create an inventory of lead service lines in the public water system, conduct sampling as indicated in the regulation, and replace lead service lines in accordance with the guidance included in the regulation.

Distribution System
Consumer Confidence Report Rule Revisions Anticipated 2025 • The intent of the proposed Consumer Confidence Report Rule Revisions is to improve clarity of water quality information reported and enhance accessibility to the information. The revised rule also increases the frequency that Consumer Confidence Reports are issued from annually to twice per year. If finalized, Consumer Confidence Reports will need to meet the new requirements beginning in 2025.
• The City should prepare to incorporate into their Consumer Confidence Reports the updated requirements for content, communication standards, and accessibility accommodations.

Distribution System
Note: Federal regulations are adopted by the State. Given California's primacy, additional requirements have been added to select regulations.

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4.1.1.2 State of California Regulations
The State regulations and guidelines summarized in this section represent enhancements to Federal regulations that have been adopted and are being implemented by the State. The current and anticipated State drinking water regulations and guidelines are summarized in Table 4-2. Revisions to existing regulations and guidelines and new regulations that are currently anticipated include:
• Maximum Contaminant Level Review – At least once every five years, the SWRCB is required to conduct a MCL Review. In this process, the SWRCB identifies a select group of its MCLs to review and evaluate for potential revision. The California Health and Safety Code requires that the MCL for a contaminant be established at a level as close to its Public Health Goal (PHG) as is technologically and economically feasible. PHGs are established by the State of California Office of Environmental Health Hazard Assessment (OEHHA). The PHG represents a contaminant level that poses no significant health risks. If an MCL is already at or below the PHG, a revision of the MCL would not present additional health benefit, and therefore would not be selected for inclusion in an MCL Review. The 2023 review cycle included the following MCLs:
— Chromium (hexavalent) (update: new State MCL is 10 micrograms per liter [µg/L], effective October 1, 2024, compliance date varies by system size) — Arsenic (current State MCL is 10 µg/L – 2023 MCL Review results are not yet known) — PFOA and PFOS (update: in April 2024, the EPA established MCLs for six PFAS species at the Federal level, and California adopted these standards) — NDMA (no MCL currently exists, the current State notification level is 0.01 µg/L – 2023 MCL Review results are not yet known)
— Disinfection Byproducts (current State MCL for TTHM is 80 µg/L, current State MCL for HAA5 is 60 µg/L – 2023 MCL Review results are not yet known) — Styrene (current State MCL is 0.1 mg/L – 2023 MCL Review results are not yet known) — Cadmium (current State MCL is 0.005 mg/L – 2023 MCL Review results are not yet known) — Mercury (current State MCL is 0.002 mg/L – 2023 MCL Review results are not yet known) The City should consider monitoring for constituents with proposed or anticipated revised MCLs to establish an understanding of the occurrence of the constituent within the water. If it is found that the constituent exists in concentrations near the MCL, the City should begin to make plans to implement mitigation. The City should also monitor for constituents that have newly-established or recently-revised MCLs.
• Microplastics – Microplastics are defined by the SWRCB as, “solid, polymeric materials to which chemical additives or other substances may have been added, which are particles which have at least two dimensions that are greater than 1 and less than 5,000 micrometers (µm). Polymers that are derived in nature that have not been chemically modified (other than by hydrolysis) are excluded”.1 The State has adopted a standard methodology for testing and reporting microplastics in drinking water. The City has been identified as one of the water systems that will potentially be asked to participate in microplastics monitoring 1 As defined by State Water Resources Control Board, Resolution No. 2020-0021, Adoption of Definition of ‘Microplastics In Drinking Water.

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during Phase 1.2 Phase 1 is anticipated to begin Fall 2023 and conclude Fall 2025. At a minimum, water systems are anticipated to be required to report concentrations of microplastics that are 50 micrometers long or the minimum size listed in the standard method utilized by the laboratory for analysis, whichever is smaller.

DDW staff perform regular inspections of water treatment and distribution facilities and summarize the results of the inspections in a Sanitary Survey. The last inspection was performed in December 2019.

Requests and recommendations contained within the inspection reports should be implemented by the City in a timely manner. The following recommendations were included in the most recent inspection report, and completion status is noted for each:
• Revise the existing bacteriological sample siting plan so that is it representative of water throughout the distribution system – In Progress.
• Develop a plan to achieve the Cryptosporidium Action Plan turbidity goal for reclaimed water for the NBR WTP – No immediate plans for construction of infrastructure to address Cryptosporidium Action Plan turbidity goals, but West Yost recommends that water treatment infrastructure to reclaim (or recycle) backwash water (e.g., contact-clarifier) be considered as a future project.
• Perform a tracer study for the existing chlorine contact basin at NBR WTP to determine the hydraulic baffling factor of the basin – West Yost recommends that the City perform a tracer study for the existing chlorine contact basin at NBR WTP, as recommended by DDW. • Identify and label the gray colored pipe labelled Non-Potable Water in the Waterman WTP filter gallery – Completed.
• Implement an alarm for possible disinfection failure at the Waterman WTP – Completed. • Update alarm set points in the Operations Plan for the Waterman WTP – Completed. • Provide pictures of ventilation openings and cathodic protection plates on the top of the Rancho Solano 3, Rancho Solano 4, Rolling Hills, Martin Hill, and Goldridge distribution tanks – Completed.
• Test the backflow prevention devises next to the cow troughs at the Rolling Hills Tank site annually – Completed.
• Install missing screen on overflow pipe at Cement Hill reservoir – Completed. • Investigate the location of the overflow pipe at the Nelson Hill reservoir site and confirm that a screen or flapper is present – Completed.
• Add the existing backflow prevention device at the Goldridge Reservoir to the backflow prevention device inventory and test annually – Completed. • Replace the vent screens on the Eastridge and Cordelia reservoirs – Completed. • Ensure distribution system backflow prevention devices are tested annually – Completed. • Ensure that overflow and vent screens are installed at distribution system reservoirs – Completed. 2 As indicated in the Policy Handbook Establishing a Standard Method of Testing and Reporting of Microplastics in Drinking Water, August 9, 2022, Division of Drinking Water, State Water Resources Control Board, State of California.

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Table 4-2. State Regulations
Regulation Status Regulation Summary Compliance Recommendation Impacted Process or System Current Regulations
Lead and Copper Rule (LCR) and Revisions Current Regulation - In Compliance
• The California Health and Safety Code required all community water systems to compile an inventory of known active partial or total lead user service lines in its distribution system by July 1, 2018. The submission deadline for the final user service line inventory was July 1, 2020.
• Another State-specific element of the LCR revisions is the "Lead Testing of Drinking Water in California Schools". As of January 17, 2017, the DDW requires that all community water systems collect and analyze up to five water samples from drinking water fountains and regularly used drinking water faucets at a school, if the testing is requested by a superintendent or designee of the school. The community water system that serves the school is responsible for all costs associated with collecting, analyzing, and reporting drinking water sample results. • The City should be aware that if any schools or childcare facilities (served by the community water system) request monitoring, the City must comply and provide monitoring.
• If action levels for lead or copper are exceeded, installation or modifications to corrosion control treatment is required. If the action level for lead is exceeded, public notification is required.

Distribution System
Cryptosporidium Action Plan
Current Regulation -
Improvements
Recommended
• The DDW initially developed the Cryptosporidium Action Plan in April 1995. The Cryptosporidium Action Plan builds off Federal Surface Water Treatment Rules (SWTRs) by providing operational guidance on suitable turbidity goals and recycle rates within the treatment plant. • Operational practices to optimize treatment performance, as outlined in the Cryptosporidium Action Plan, include: 1) produce filter effluent turbidity values less than 0.1 NTU, 2) meet turbidity goal of 1 to 2 NTU in the effluent of the sedimentation basin at all times, 3) attempt to achieve filtered water turbidities of 0.3 NTU or less after backwash, 4) establish an operational goal of less than 2.0 NTU for the reclaimed water returned to the headworks of the treatment plant. • The flow rate of the reclaimed water returned to the headworks should not exceed ten percent of the incoming treatment plant flow rate. • Recent Sanitary Surveys conducted by the DDW note that turbidity of reclaimed water returned to the headworks of the treatment plant exceed values defined in the Cryptosporidium Action Plan at the NBR WTP. Capital improvements or operational modifications should be made to achieve compliance.

Sedimentation Basins, Filters,
Reclaimed Water
Notification and Response Levels for Cyanotoxins
Current Regulation -
Monitoring
Recommended
• Notification levels (NL) are non-regulatory, health-based advisory levels for contaminants established as precautionary measures for contaminants. Response levels (RL) are established in conjunction with notification levels and represent the concentration of a drinking water contaminant at which additional steps, beyond notification, are recommended to reduce public exposure.
• As of June 16, 2022, The Office of Environmental Health Hazard Assessment (OEHHA) has submitted to the SWRCB recommendations for acute notification levels for four cyanotoxins, as follows: Anatoxin-a, 8 ppb; Microcystins, 3 ppb; Cylindrospermopsin, 3 ppb; and Saxitoxin,

0.5 ppb.
• Water systems should comply with these updated NL and RL values. If the average of two subsequent sample results (sample and field duplicate) exceeds the RL, the result must be reported to the SWRCB within 48 hours.
• The City should consider monitoring for these four cyanotoxins in the source water and treated water, particularly during times when the algae species may be present in untreated source water, such as during the spring and summer months. Note that treatment processes may release cyanotoxins from algae cells due to lysing of the cells, therefore absence of cyanotoxins in untreated source water does not mean that cyanotoxins will necessarily be absent from treated water.

Raw Water and Entry Point to the
Distribution System
Notification and Response Levels for Manganese Current Regulation - In Compliance
• On February 16, 2023, the DDW proposed revised NL and RL for manganese. The new NL is 20 ppb, and the new RL is 200 ppb. The previous NL and RL were 500 and 5,000 ppb, respectively. • In addition to the NL and RL, manganese also has a secondary MCL of 50 ppb. In California, secondary MCLs are enforceable.
• Water systems should comply with the updated NL and RL values. If the average of two subsequent sample results (sample and field duplicate) exceeds the RL, the result must be reported to the SWRCB within 48 hours.
• The City is already collecting samples for manganese data in both raw water sources, as well as in the treated water from the Waterman and NBR WTPs. Treated water samples are consistently below the new 20 ppb notification level at both WTPs.
• Although the NL only applies to treated water, the City should continue to monitor manganese in the North Bay Aqueduct and Putah South Canal, as manganese in these source waters has exceeded the NLs in recent years and could affect the WTPs ability to maintain compliance in the treated water.

Raw Source Water and Treated
Water

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Table 4-2. State Regulations
Regulation Status Regulation Summary Compliance Recommendation Impacted Process or System Notification and Response Levels for Polyfluoroalkyl
Substances (PFAS)
Current Regulation -
Monitoring
Recommended
• NLs and RLs are set for four PFAS chemicals: PFOA, PFOS, PFBS, and PFHxS.
• The NL for PFOA is 5.1 ppt and the RL is 10 ppt. The NL for PFOS is 6.5 ppt and the RL is 40 ppt. The NL for PFBS is 500 ppt and the RL is 5,000 ppt.

The NL for PFHxS is 3 ppt and the RL is 20 ppt.
• Water systems should comply with these updated values. If the average of two subsequent sample results (sample and field duplicate) exceeds the RL, the result must be reported to the SWRCB within 48 hours. • The City should monitor for these chemicals to establish baseline concentrations of the contaminants.

Raw Source Water and Treated
Water
Anticipated Regulations and Revisions
Microplastics Anticipated Regulation
(Fall 2023 - Fall 2025)
• Monitoring and reporting requirements are in development for public water systems to conduct monitoring of microplastics in drinking water. • Large community water systems may receive monitoring orders and be subject to multi-year testing and reporting of microplastics in drinking water. The City has been identified as a likely participant in the Phase 1 monitoring for microplastics, which will begin Fall 2023 and last for 2 years (Fall 2025).
• The City should consider beginning to take samples to establish a baseline microplastics concentration and prepare to participate in the Phase 1 monitoring program if requested.

Distribution System
MCL Review Process
Current and
Anticipated
Regulations (2023 MCL
Review Process) –
Monitoring Required
for Compliance
• The SWRCB is required to review MCLs at least once every five years. Of the MCLs selected for review in this cycle, some contaminants are subject to potential lowering of their MCL, while others only have hazard indexes and may be assigned a MCL in this process.
• The MCLs in review for the 2023 cycle included:
- Chromium (hexavalent)
- Arsenic
- PFOA and PFOS
- NDMA
- Disinfection Byproducts
- Styrene
- Cadmium and Mercury
• If MCLs are set or revised for any of these identified contaminants, compliance with the revised MCL will be required within two to four years, depending on water system size.
• As of April 10, 2024, MCLs were set for six PFAS species at the Federal level, and California adopted these standards.
• DDW established a State MCL of 10 ppb for hexavalent chromium, effective October 1, 2024. Compliance date varies by system size. Initial sampling should be completed by April 1, 2025. Compliance plans are required within 90 days before the compliance date applicable to the system for sources that exceed the MCL.
• The City should consider beginning to monitor for the contaminants included in this 2023 MCL Review Process to establish baseline concentrations of the contaminants.
• Compliance recommendations specific to PFAS are presented in Table 4-1.

Treatment Plants

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Operational data for the NBR WTP indicates that the turbidity goal for reclaimed water established within the Cryptosporidium Action Plan is not being achieved. Since this was also noted in the most recent Sanitary Survey, it is recommended that the City develop a plan to meet the turbidity goal. This could be accomplished by constructing new infrastructure to treat the reclaimed water and reduce the turbidity or by modifying the operation of the existing system to lower the reclaimed water’s turbidity.

4.1.2 National Pollution Discharge Elimination System Permit The City has obtained coverage under SWRCB Order WQ 2014-0194-DWQ; this general order authorizes planned and emergency discharges from drinking water systems to surface waters for essential operations of water purveyors, including activities such as meter testing, flushing, treatment plant operations, etc.

To comply with the permit, the City is required to implement best management practices to treat or control pollutants from discharge, such as dechlorinating, minimizing sediment discharge, and preventing erosion.

The City is also required to submit monitoring reports to the State to document discharge activities.

The City has prepared and submitted annual reports to the SWRCB. The annual reports document the types of discharges that occurred, identify if any non-compliant discharges occurred, and indicate the estimated volume discharged during the year. The City is in compliance with the permit and there are no additional recommendations to achieve compliance.

4.1.3 Bay Area Air Quality Management District Policies The Waterman WTP and NBR WTP hold permits from the Bay Area Air Quality Management District (BAAQMD) for the operation of ozone generators and standby emergency generators. The City is currently in compliance with the permits.

To maintain compliance with the permits issued for the ozone generators, the City must ensure that the ozone destruct system, which catalytically converts ozone (O3) present in the contactors’ off-gas to oxygen gas (O2) is in operation at all times that the ozone generators are operating. Additionally, the ozone gas concentration remaining in the off-gas must be below Occupational Safety and Health Administration’s (OSHA’s) 8-hour regulatory exposure limit (0.1 parts per million [ppm]). The ozone destruct system should be regularly inspected and maintained so that it functions as designed and when needed.

To maintain compliance with the permits issued for the standby emergency generators, the City must comply with the operating, reporting, and record keeping requirements indicated within the permit, including:
• A maximum of 50 hours of reliability related testing per year per engine • Operation of each engine only for mitigation of emergency conditions, testing to demonstrate compliance with emissions limits, or testing for reliability related activities (maintenance and testing)
• Presence of a non-resettable totalizing meter installed, operated, and properly maintained for each engine
• Maintenance of monthly records of hours of operation for reliability related activities, hours of operation for emission testing to show compliance with emission limits, hours of operation for emergency purposes, nature of each emergency condition, and fuel usage • Retention of records for at least 36 months from the date of entry

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BAAQMD staff communicated that it is possible that the best available control technologies (BACT) for backup power generators may be contemplated in the future; however, at this time, no changes are anticipated.

4.1.4 Summary of Recommendations
The City should continue to be aware of and prepare for regulatory changes as they are issued and as they become enforceable.

To prepare for upcoming regulations, it is recommended that the City begin to collect samples and data for constituents that may have new or revised regulatory limits, such as PFOS, PFOA, manganese, and disinfection byproducts. By establishing a robust set of historical data for these constituents, the City can be prepared to take action, if necessary, once the regulatory requirements are finalized. Early identification of elevated levels of constituents within the City’s two source water supplies, treated water, and/or distribution system can enable the City to have sufficient time to implement capital or operational solutions so that it is ready to comply with future regulations.

It is also recommended that the City consider improvements to the NBR WTP reclaimed water treatment system in order to achieve the turbidity goals identified within the Cryptosporidium Action Plan (turbidity less than 2 NTU in reclaimed water returned to head of the treatment process). Operating data indicates that the current spent filter backwash water reclamation treatment system is not consistently delivering reclaimed water that has turbidity less than 2 NTU, and the DDW noted in its report for the most recently conducted Sanitary Survey that the NBR WTP was not achieving the turbidity goals of the Cryptosporidium Action Plan.

A summary of recommendations for regulatory compliance, at both the Federal and State levels, is presented in Table 4-3.

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Last Revised: 01-20-2025
Table 4-3. Summary of Recommendations
Constituents or Process Areas of
Concern
Relevant Regulation,
(Federal or State Level) Recommendation for Compliance
Capital Improvements or Operational Modifications
Turbidity of Reclaimed Water
at NBR WTP
Cryptosporidium Action Plan
(State)
• Recent Sanitary Surveys conducted by the DDW note that turbidity of reclaimed water returned to the headworks of the treatment plant exceed values defined in the Cryptosporidium Action Plan at the NBR WTP. Capital improvements or operational modifications should be made to achieve compliance.

Disinfection System
Hydraulic Baffling Factor of
Chlorine Contact Basin at

NBR WTP
Tracer Study for
Disinfection System
(State)
• The City should perform a tracer study for the existing chlorine contact basin at NBR WTP, as recommended by DDW in the 2019 Sanitary Survey.

Increased Sampling and Monitoring
Cyanotoxins
Notification and Response Levels
for Cyanotoxins
(State)
• The City should consider monitoring for the four cyanotoxins (that have NLs and RLs) in the source water and treated water, particularly during times when the algae species may be present in untreated source water, such as during the spring and summer months.

Note that treatment processes may release cyanotoxins from algae cells due to lysing of the cells, therefore absence of cyanotoxins in untreated source water does not mean that cyanotoxins will necessarily be absent from treated water.

Manganese
Notification and Response Levels
for Manganese
(State)
• Although the NL for manganese only applies to treated water, the City should continue to monitor manganese in the North Bay Aqueduct and Putah South Canal, as manganese in these source waters has exceeded the NLs in recent years and could affect the WTPs ability to maintain compliance in the treated water.

Polyfluoroalkyl Substances
(PFAS)
Notification and Response Levels
for PFAS
(State)
• The City should monitor these chemicals to establish baseline concentrations (specifically PFOA, PFOS, PFBS and PFHxS, which have NLs and RLs in California).

MCLs for Six PFAS Chemicals
(Federal)
• EPA established MCLs for six PFAS chemicals: PFOA 4.0 ppt, PFOS 4.0 ppt, PFHxS 10 ppt, PFNA 10 ppt, HFPO-DA (GenX) 10 ppt, and PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS using a Hazard Index MCL of 1 (unitless) to account for the combined and co-occurring levels of these PFAS in drinking water. • The City has until 2027 to complete initial monitoring of these PFAS, and until 2029 to implement treatment if any MCLs will be exceeded.

Microplastics Microplastics Monitoring
(State)
• The City should consider beginning to take samples to establish a baseline microplastics concentration and prepare to participate in the Phase 1 monitoring program if requested.

Disinfection Byproducts
Potential Revisions to Microbial and
Disinfection Byproduct Rules
(Federal)
• The City should consider starting to compile and track speciation of DBPs, particularly the more brominated forms of THMs and HAAs, as monitoring may be required in the future.

This would also call attention to any species that might have particularly high concentrations that could heavily influence total concentrations. - Chromium (hexavalent)
- Arsenic
- PFOA and PFOS
- NDMA
- Disinfection Byproducts
- Styrene
- Cadmium and Mercury
2023 MCL Review Process
(State)
• The City should consider beginning to monitor for the contaminants included in the 2023 MCL Review Process to establish baseline concentrations of the contaminants. • The City should perform the required monitoring for hexavalent chromium and the six PFAS species as outlined in the compliance timelines for the MCLs established in 2024.

Contaminants on Recent
CCL Lists
Contaminant Candidate List
(Federal)
• The City should consider sampling and monitoring (per CCL established sampling intervals) for the new contaminants on the more recent CCL lists, such as CCL 5, which includes 81 contaminants or contaminant groups of chemicals, cyanotoxins, disinfection byproducts, PFAS chemicals, and microbes.

Notes:

See Table 4-1 for additional information on Federal regulations.

See Table 4-2 for additional information on State regulations.

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4.2 MUNICIPAL CODE (CHAPTER 22) REVIEW
Fairfield Municipal Code (FMC) Chapter 22 governs the use of water in the City’s water service area and applies to all water users. It also provides the City authority to implement State and local rules and regulations to provide efficient and economical water supply while protecting public health and safety.

Since its codification circa 1980, sections of the FMC Chapter 22 have been incrementally updated. West Yost conducted a comprehensive review of the chapter for consistency with State regulations, City practices, and overall clarification. A summary of West Yost’s recommendations is provided below:

1. Consistency with current and pending State regulations. Revisions were proposed for compliance with recent ADU requirements under Government Code 65852.2. Pending water use regulations associated with the State’s 2018 Legislation (Senate Bill 606 and Assembly Bill 1668) were also considered. However, as rulemaking is not yet finalized for water use objectives (i.e., State targets for water use that ensure water is used efficiently and sustainability), the City may need to review current water use provisions when regulations are finalized.

2. Authority to implement the City’s Water Shortage Contingency Plan (WSCP). The WSCP, adopted by the City Council in June 2021, was prepared for compliance with Water Code Section 10632. Revisions were proposed to update emergency response authorizations.

Water shortage levels were defined for consistency with the State’s standard water shortage levels for effective public messaging and State reporting. Provisions for appropriate water demand reduction actions were authorized based on water shortage levels.

3. Consistency with City practices. Over the years, the City has adopted policies and practices to efficiently and economically provide water services, while protecting public health and safety. The FMC Chapter 22 was reviewed with City staff to identify outdated sections.

Provisions were developed to authorize implementation of the City’s most current policies and authorize staff to effectively apply the rules and regulations associated with water supply.

4. Overall clarification. FMC Chapter 22 was reorganized and edited so that rules and regulations are clarified for comprehension and to minimize misinterpretation.

Furthermore, FMC Chapter 22 was revised to allow updates to rates and charges without the need to revise the FMC.

The revised and recodified FMC Chapter 22 is available at https://www.fairfield.ca.gov.

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CHAPTER 5
Water System Evaluation Criteria
This chapter defines the recommended planning criteria to be used for evaluating the performance and sizing of the City’s water distribution system. These criteria include required fire flow and flow duration, supply and pressure requirements during normal and emergency conditions, pump station capacity requirements, storage capacity requirements, and performance requirements for future pipelines. The following sections of this chapter present the recommended planning criteria for the City’s water distribution system:
• General Water System Guidelines
• Water System Performance
• Facilities Sizing
Table 5-1 at the end of this chapter summarizes the recommended water system evaluation criteria for this PUMP, which are discussed in more detail in the sections below.

5.1 GENERAL WATER SYSTEM GUIDELINES
Before discussing specific water system evaluation criteria, it is helpful to provide some general guidelines that a water system should meet. This section identifies the requirements for a reliable water system that delivers high-quality water.

5.1.1 Water System Reliability
Based on industry standards, a reliable water system is one that has sufficient storage, redundant pumping and distribution facilities, and emergency alternatives for both water and power supply.

Thoughtful water distribution system design also enhances reliability through improved hydraulics and redundancy. For example, replacing pipeline dead-ends with looped configurations improves reliability and reduces the risk of stagnant water, which has poor taste and lower disinfectant residuals. Appropriate pipeline sizing allows the system to serve peak demands at appropriate pressures while minimizing friction losses. Lastly, proper valve placement streamlines maintenance and repairs, while also increasing operational flexibility.

5.1.2 Water Quality Standards
The EPA and the SWRCB DDW establish water quality standards to protect public health and help manage aesthetics. Primary drinking water standards are legally enforceable limits on contaminants that present a risk to human health. In contrast, secondary standards target contaminants that are not health threatening, but may cause taste, odor, or color issues. As a water retailer, the City is responsible for ensuring that all applicable water quality standards and regulations are always met.

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5.2 WATER SYSTEM PERFORMANCE
This section describes the recommended system performance criteria for fire flows, supply capacity, and distribution system pressures.

5.2.1 Fire Flow Requirements
The City’s Fire Department (Fire Department) has jurisdiction for firefighting within the City and is responsible for establishing criteria such as minimum water flows and residual system pressures during a firefighting event. The Fire Department conforms to the California Fire Code, 2022 Edition and uses Appendix B (and Appendix BB) of the code, Fire Flow Requirements for Buildings, to assist in establishing minimum fire flows and durations for individual structures. Much of the existing development within the City was constructed before fire sprinklers were required. However, for new development, the City requires fire sprinklers to be installed in all residential structures1 and all other buildings greater than 3,600 square feet,
2 which reduces the minimum fire flow required for those individual buildings.

The City also considers the Insurance Services Office, Inc. (ISO) standards in determining fire flows to use for evaluating system performance. The ISO requirements for many non-residential structures generate fire suppression flows of 6,000 gpm or more. Although the ISO rating system allows agencies with large systems to cap the design flows at 3,500 gpm, the City has consistently and conservatively chosen not to use this cap in designing their system. This has allowed larger development projects with higher fire flow demands to be built without the need for additional on-site or off-site improvements in most cases.

This PUMP assumes fire flow requirements based on generalized land use types and does not perform precise calculations on a building-by-building basis. These fire flow requirements will be used in subsequent chapters to assess distribution system adequacy under existing and future water demand conditions. Therefore, the fire flow requirements presented in this PUMP are intended only for general planning purposes and reflect historical requirements previously used by the City. 1 The City’s 2021 Engineering Design Standards state that fire sprinklers will be required in all residential structures, unless otherwise approved by the Fire Marshal. 2 The Fairfield Municipal Code (Chapter 8 – Fire Protection, Section 8.3 Amendments, Additions and Deletions, Subsection 903.2) specifies that all buildings greater than 3,600 square feet shall be equipped throughout with an approved fully automatic fire sprinkler system. When accessed, the code was current through Ordinance 2024-07, passed October 1, 2024.

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Table 5-2 summarizes the recommended minimum fire flow requirements by generalized land use type correlated to the land use designations established in the City’s General Plan Update Alternatives Report. 3 Each land use type contains two different fire flow requirements, one for evaluating facility capacity, and one for evaluating hydraulic performance in the distribution system, as described below. • Fire Flow Requirements for Evaluating Facility Capacity – These fire flow criteria are based on historical requirements provided by the City, as further explained in a technical memorandum (TM) dated March 2023, which is included in Appendix A of this PUMP. They will be used in the existing and future supply, pumping, and storage capacity evaluations to conservatively size these facilities for redundancy. The durations shown in Table 5-2 will be used to establish the quantity of fire storage needed.
• Fire Flow Requirements for Evaluating Hydraulic Performance – These fire flow criteria are based on conversations with the City’s Fire Marshal to determine what fire flows are typically required for new developments. These requirements are different between existing buildings and future development projects, as described below:
— Existing Buildings: For the purposes of this PUMP, it is assumed that pipelines adjacent to existing buildings were sized to accommodate fire flow criteria that were in place at the time of their construction. Therefore, the existing pipelines were evaluated to confirm that the City’s goal to provide a minimum available fire flow of 1,500 gpm is achieved throughout its existing distribution system.
— Future Development Projects: For the purposes of this PUMP, the City shall be able to deliver the minimum fire flows identified in the last column of Table 5-2 to future development projects. Land-use based fire flow requirements, such as those presented in Table 5-2, are appropriate to assign to future development at this stage of planning because specific building size and type are unknown.

When delivering fire flow to existing buildings or future development, the City’s water system shall be able to concurrently meet maximum day demands and maintain at least 20 pounds per square inch (psi) residual pressure at service connections, which is the minimum pressure recommended by the National Fire Protection Association (NFPA). For further discussion on maximum day demands and other peak demand conditions for the City, refer to Chapter 3 Water Demands.

The values presented in Table 5-2 have been reviewed by the Fire Department to confirm the applicability of the recommended fire flows for general planning purposes only. These recommended fire flow requirements are not reflective of actual fire flow requirements sought for specific development approvals and do not identify specific existing non-conforming developments. Ultimately, the Fire Department remains the entity responsible for setting and enforcing fire flow requirements for individual structures as future developments are approved.
3 Dyett & Bhatia Urban and Regional Planners. October 2021. City of Fairfield General Plan Update Alternatives Report

Requirements for
Evaluating Hydraulic
Performance
Recommended Generalized
Fire Flow Land Use From General Plan Update(b)
Fire Flow(c),
gpm
Duration(c),
hours
Recommended
Storage, MG(d) Fire Flow(e), gpm
Rural Residential
Single Family Residential
Single Family Residential - Attached
Mobile Home Park
Multi-Family Residential
Residential Care/Assisted Living Facility
General Commercial
Service Stations
Hotel, Motel, Lodging Commercial
Mixed Use
Office
Light Industrial
Heavy Industrial
Hospital
Public/Government Owned
Church/Religious Facility
School/Educational Facility
Public Transit
Utilities
Parks and Recreation
Open Space, Greenways, Trails, and
Protected Areas
Agriculture
Agriculture/Conservation
Vacant
2,500
2,500
Multi-Family Residential 4,500 4
Table 5-2. Recommended Fire Flow Requirements(a)
Single Family Residential 1,500 2 0.18
Land Use Designation
Requirements for Evaluating
Facility Capacity
1,500
2,500
(a) Construction type and fire flow calculation area are not generally known during the development of a water master plan. Consequently, fire flow requirements set forth in this table are based on previous estimates for these land use types and similar communities. Unique projects or projects with alternate materials may require higher fire flow and shall be reviewed by the Fire Chief on a case-by-case basis. (b) Dyett & Bhatia Urban Regional Planner, October, 2021. City of Fairfield General Plan Update Alternatives Report. Refer to Figure 2-2, Existing Land Use. (c) Recommended fire flows and durations for sizing supply, pumping, and storage facilities are based on historical requirements provided by the City.

Refer to Appendix A for memorandum provided by Coastland. (d) Recommended storage shows the minimum recommended fire flow storage needed to fight a fire associated with each land use type. Fire flow storage should be evaluated for each pressure zone separately, using the largest potential fire event that could occur within that pressure zone. (e) Recommended fire flows for evaluating conveyance capacity and sizing pipelines are based on conversations with the City's Fire Marshal and City staff to determine what is typically required for new developments. These have been reduced in recent years due to recent requirement for sprinkers to be added to new construction.
gpm = gallons per minute; MG = million gallons.

Institutional 4,500 4 1.08 2,500
None -- -- -- --

1.08 Commercial
Industrial 6,000 6 2.16
6,000 6 2.16
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5.2.2 Water Supply Capacity
As previously described in Chapter 2 Existing Water System, all the City’s water supply comes from two surface water treatment plants. The Waterman WTP has a rated treatment capacity of 30 mgd, and the NBR WTP has a rated treatment capacity of 40 mgd. However, not all of that supply capacity is always available, due to actual performance limitations like filter backwashing, as well as regular maintenance, and unanticipated disruptions such as equipment failure. To account for these limitations, water supply capacity is evaluated using firm supply, rather than total supply available. For the City, firm supply capacity is defined differently for existing and future conditions, as described below. These definitions are based on direction provided by the City in a TM dated October 2023, which is provided in Appendix B of this PUMP. • Waterman WTP
— Existing Firm Capacity: According to City staff, the current performance capacity of Waterman WTP is 25 mgd. Since this is the smaller of the City’s two water treatment plants, existing firm capacity is defined as 100 percent of actual performance capacity, or 25 mgd.
— Future Firm Capacity: In the future (starting at 2030), it is assumed that Waterman WTP will be rehabilitated back to its rated capacity of 30 mgd. Since this will remain the smaller of the City’s two water treatment plants in the future, future firm capacity is defined as 100 percent of the rated capacity, or 30 mgd. • NBR WTP
— Existing Firm Capacity: According to City staff, the current performance capacity of NBR WTP is 32 mgd. Since this is the larger of the City’s two water treatment plants, existing firm capacity is defined as 90 percent of the actual performance capacity, or 28.8 mgd.

From there, the capacity currently allocated to Vacaville (13.3 mgd) must be subtracted, for a total existing firm capacity for Fairfield of 15.5 mgd. — Future Firm Capacity: In the future (starting at 2030), it is assumed that NBR WTP will be rehabilitated back to its rated capacity of 40 mgd. Since this will remain the larger of the City’s two water treatment plants in the future, future firm capacity is defined as 90 percent of the new performance capacity, or 36 mgd. From there, the capacity currently allocated to Vacaville (13.3 mgd) must be subtracted, for a total future firm capacity for Fairfield of 22.7 mgd.

To evaluate water supply capacity, two conditions are considered: (1) non-emergency conditions, and (2) emergency conditions. Under non-emergency conditions, the City shall have a firm supply capacity capable of meeting a maximum day demand condition. Storage is not considered a supply source to meet maximum day demand requirements because it is depleted throughout the day and must be replenished.

Under emergency conditions, the goal of the City’s water system is to provide the greater of: (1) four hours of peak hour demands, or (2) maximum day demand plus fire flow through a combination of available firm supplies and storage. Storage facilities are assumed to support the system because storage is intended to balance supply and demand during peak use and emergency conditions. Adopted peaking factors to represent high demand conditions (i.e., maximum day demand and peak hour demand) are discussed in Chapter 3 Water Demands.

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5.2.3 Distribution System Pressures
Adequate system pressure is a basic indicator of acceptable water distribution system performance. The recommended planning criteria for system pressures are:
• Non-emergency (Normal) Operating Conditions
— Minimum Allowable Pressure: 40 psi
— Minimum Target Pressure: 45 psi
— Maximum Allowable Pressure: 120 psi4
• Emergency (Fire Flow) Conditions:
— Minimum Allowable Pressure: 20 psi
These performance criteria were applied to all customer connections that fall within the normal service elevation ranges for each pressure zone. Customers located above or below the normal service elevation ranges may require an individual booster pump or pressure regulator.

Pressures are the most critical criterion because they are used to evaluate satisfactory system performance under different demand conditions. Consequently, the City’s existing water system was evaluated using pressure as the primary criterion. Secondary criteria, such as pipeline velocity, head loss, age, and material type, were used as indicators to locate where water system improvements may be needed and help prioritize them.

5.3 FACILITIES SIZING
This section describes the recommended criteria governing the size of water facilities within the City’s service area, including pump stations, backup power, storage reservoirs, and pipelines.

5.3.1 Pump Station Capacity and Backup Power
Sufficient water system pumping capacity shall be provided to meet the demands of the pressure zone under the conditions listed below. Pump stations located in lower pressure zones must be sized to serve all pressure zone(s) located above them.
• Pressure Zones with Storage: Pump station(s) supplying the pressure zone must provide firm capacity equal to the maximum day demand.
• Pressure Zones without Storage (i.e., served by hydropneumatic tanks): Pump station(s) supplying the pressure zone must provide firm capacity equal to the larger of either (1) the maximum day demand plus fire flow, or (2) the peak hour demand.

Firm pump station capacity is defined as the total operational pump station capacity with the largest pump out of service, not including the fire pump, which is always assumed to be operational. This assumption 4 The California Plumbing Code (CPC) requires that individual services that exceed 80 psi have an individual pressure regulator on the service line.

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ensures the reliability and flexibility of the system to provide sufficient pumping capacity if a pump is out of service for any reason.

5.3.1.1 Backup Power and Critical Pumping Facilities
A pumping facility is defined as critical if it provides service to pressure zone(s) and/or service area(s) which do not have sufficient emergency storage available (see Section 5.3.2.3 Emergency Storage) and if it meets at least one of the following criteria:
• The largest pumping facility that provides water to a particular pressure zone and/or service area;
• A pumping facility that provides the sole source of water to single or multiple pressure zones and/or service areas; or
• A pumping facility that provides water from a water treatment plant.

All critical pumping facilities shall be equipped with an on-site backup power generator. At less critical facilities, a plug-in adapter and transfer switch will be used to allow interconnection to a portable generator, which can be brought to the site by City staff during a prolonged power outage.

5.3.2 Storage Reservoir Capacity
Total treated water storage capacity requirements are evaluated based on the following three components:
• Operational Storage
• Fire Storage
• Emergency Storage
Each storage component is discussed below. The recommended water storage capacity for the City’s water system will be evaluated by pressure zone.

5.3.2.1 Operational Storage
Operational storage is defined as the amount of stored water needed to meet peak demands in excess of normal supply delivery. Since water supplies are generally designed to meet maximum day demands, operational storage is typically used to supply peak demands (e.g., the difference between peak hour and maximum day demand). Supplies replenish operational storage during periods of lower demand.

In accordance with American Water Works Association (AWWA) guidelines, 5 West Yost recommends the
operational storage volume be 25 percent of the maximum day demand. 5 AWWA Manual M32, Distribution Network Analysis for Water Utilities (AWWA, 2012) states that for large systems, the equalizing storage requirement is typically 15 to 20 percent of the total maximum day demand over a 24-hour period, but equalizing storage could exceed 30 percent for small service areas or arid climates (page 116). The AWWA Water Distribution Systems Handbook (AWWA, 2000) (Section 3.2.2.2 Storage) states that the volume of operational storage required is a function of the diurnal demand fluctuation in a community and is commonly estimated at 25 percent of the total maximum day demand.

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5.3.2.2 Fire Storage
Fire storage is the volume of water reserved for fire suppression. For a given pressure zone, the fire storage volume is determined by multiplying the maximum required fire flow rate by the required duration time. It is assumed that no more than one fire flow event would occur in any pressure zone at one time for determining fire storage capacity. Table 5-2 presents the recommended fire flow storage for each land use designation.

5.3.2.3 Emergency Storage
Emergency storage helps meet demands during an unplanned event that reduces the quality and/or quantity of potable water supplies. Determining the appropriate emergency storage volume is challenging, as it depends on the diversity of supplies, the reliability of production and distribution facilities, and the duration of the emergency event. The City’s overall risk tolerance is also a factor. The AWWA suggests that individual utilities should determine their specific emergency storage requirements based on perceived system vulnerabilities.

West Yost recommends an emergency storage volume equal to two times the average day demand, consistent with the City’s previous planning documents.

5.3.2.4 Total Storage Capacity Recommended
The City’s recommended total water storage capacity is the sum of the following components:
• Operational Storage: Volume of water to meet diurnal peaks, assumed to be 25 percent of the maximum day demand; plus
• Fire Storage: Volume of water to supply a fire flow event (varies by land use designation); plus • Emergency Storage: Volume of water as emergency supply during unplanned events, assumed to be two times the average day demand.

The amount of total system storage required to meet these criteria will change over time as the City continues to grow and water demands change.

5.3.3 Pipeline Sizing
The following criteria will be used as guidelines for sizing transmission and distribution system pipelines for new developments. The City’s existing water system was evaluated using system pressure as the primary criterion. As mentioned above, secondary criteria, such as pipeline velocity, head loss, age, and material type, are used as indicators to locate and help prioritize where water system improvements may be needed.

Therefore, the City’s existing system was evaluated on a case-by-case basis. For example, if an existing pipeline experiences velocity or head loss in excess of the criteria described below, this condition, by itself, does not necessarily indicate a problem as long as the minimum system pressure criterion is satisfied. Other conditions such as pipeline age, material type, and location in the system were also considered.

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The following list summarizes the general definitions and City standards for transmission and distribution pipelines:
• Transmission mains are defined as pipelines with a diameter of 24 inches or greater. 6 • Distribution mains are defined as pipelines with a diameter less than 24 inches. • All new pipelines are required to be ductile iron pipe (DIP) or PVC. 7 • All new pipelines are required to have a minimum diameter of 8 inches. The installation of 6-inch diameter pipelines may be permitted in cul-de-sacs where there is no fire hydrant installed.
8 • All new pipelines serving commercial and industrial land uses shall have a minimum diameter of 12 inches.

Pipeline sizing is based on velocity; higher velocities translate to higher head loss and increased operating costs. The following criteria reflect industry standards and West Yost’s experience with municipal water systems:
• For transmission mains, the maximum velocity shall be limited to 5 feet per second (fps). • For distribution mains, the maximum velocity shall be limited to 7 fps under normal demand conditions. During fire flow demand conditions, the maximum velocity shall be 12 fps. 6 Discussed during the PUMP Kickoff Meeting with the City on January 10, 2023. 7 2021 Specific Provision for Fairfield, Section 12: Water Distribution, 12.2 Materials, A. Mains (Page 45). 8 2021 Engineering Design Standard for Fairfield, Section 6: Water System, 6.2 Design, B. Sizes (Page 43).

Table 5-1. Summary of Recommended Water System Evaluation Criteria Condition Criteria Comments
Water System Performance
Fire Flow Requirements (a)
Single Family Residential 1,500 gpm @ 2 hrs
Multi-Family Residential and
Institutional 4,500 gpm @ 4 hrs
Commercial and
Industrial 6,000 gpm @ 6 hrs
Single Family Residential 1,500 gpm
Multi-Family Residential,
Institutional,
Commercial, and
Industrial
2,500 gpm
Water Supply Capacity
Normal Operating Conditions Provide firm supply capacity from water treatment plants equal to maximum day demand
Firm supply capacity is defined as 100 percent of
reliable performance capacity at Waterman WTP and
90 percent of reliable performance capacity at NBR
WTP.

Emergency Operating Conditions
Provide firm supply capacity from a combination of water treatment plants and storage reservoirs equal to the greater of (1) four hours of peak hour demands or (2) the maximum day demand plus fire flow
Criteria applies both systemwide and to each
individual pressure zone.

Distribution System Pressure
Non-Emergency (Normal) Conditions
Minimum Allowable: 40 psi
Minimum Target: 45 psi
Maximum: 120 psi
Emergency (Fire Flow) Conditions Minimum Allowable: 20 psi Facility Sizing
Pump Station Capacity and Backup Power
Pumping Capacity - Zones With Storage Provide firm pumping capacity equal to maximum day demand Pumping Capacity - Zones Without Storage
Provide firm pumping capacity equal to the larger of:
(1) maximum day demand plus fire flow
(2) peak hour demand
Backup Power Equal to the firm capacity of the pumping facility On-site generator for critical stations. Plug-in portable generator for less critical stations.(b)
Storage Reservoir Capacity
Operational Storage 25 percent of maximum day demand
Fire Storage Equal to the largest fire flow requirement and associated duration
Refer to Table 5-2.

Emergency Storage Two times the average day demand For emergencies such as power outages when pump stations may not be in service.

Total Storage Capacity Operational + Fire + Emergency Storage capacity shall be evaluated by pressure zone.

Water Transmission Pipelines(c)
Diameter 24-inches in diameter or greater
Maximum Velocity 5 fps New development only.

Hazen Williams "C" Factor 130 For consistency in hydraulic modeling.

Pipeline Material Ductile Iron For consistency in hydraulic modeling.

Water Distribution Pipelines(c)
Diameter Less than 24-inches in diameter Minimum diameter of 8-inches unless permitted.

Maximum Velocity - Normal Conditions 7 fps New development only.

Maximum Velocity - Emergency Conditions (Fire) 12 fps New development only.

Hazen Williams "C" Factor 140 For consistency in hydraulic modeling.

Pipeline Material PVC For consistency in hydraulic modeling.

Firm pumping capacity is defined as the total capacity
of all operational pumps minus the capacity of the
largest pump, except for fire pumps.

Fire flows based on new development requirements.

Existing development will be evaluated on a case-bycase basis.

Refer to Table 5-2 for additional details.

For Evaluating Facility Capacity
For Evaluating Hydraulic Performance
(a) Fire flow requirements are presented only as general planning guidelines to evaluate the capacity of the City's water system. Proposed development shall be evaluated on a case-by-case basis. The facility capacity requirements can be used to evaluate supply, pumping, and storage capacity, while the hydraulic performance requirements can be used to evaluate conveyance capacity in the distribution system and size pipelines. (b) A pumping facility is defined as critical if it provides service to pressure zone(s) and/or service area(s) without sufficient emergency storage and if it meets at least one of the following criteria:
- The largest facility that provides water to a particular pressure zone - A facility that provides the sole source of water to single or multiple pressure zones - A facility that provides water from a water treatment plant (c) Recommended pipeline velocity is used for sizing pipelines for new development. Existing pipelines not meeting the recommended criterion would not be identified as deficient unless pressure deficiencies also exist.
gpm = gallons per minute; hrs = hours; CPC = California Plumbing Code; psi = pounds per square inch; fps = feet per second; PVC = polyvinyl chloride Pressure criteria are relevant at customer service
connections. Per 2022 CPC, individual services with
pressure greater than 80 psi require an individual
pressure regulator.

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5.4 REFERENCES
American Water Works Association, 2017. Manual of Water Supply Practices (M32) Computer Modeling of Water Distribution Systems, Fourth Edition.

California Building Standards Commission, 2022. 2022 California Plumbing Code, California Code of Regulations, Title 24, Part 5.

City of Fairfield, 2021. 2021 Engineering Design Standard for Fairfield.

City of Fairfield, 2021. 2021 Specific Provision for Fairfield.

City of Fairfield, 2024. Fairfield Municipal Code, A Codification of the General Ordinances of the City of Fairfield, California. Current through Ordinance 2024-07, passed October 1, 2024.

Dyett & Bhatia, 2021. City of Fairfield General Plan Update Alternatives Report. October 2021.

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CHAPTER 6
Existing Water System Evaluation
This chapter evaluates the City’s existing water system and its ability to meet recommended planning and performance criteria defined in Chapter 5 of this PUMP. Both system capacity (i.e., treatment, storage, and pumping) and hydraulic performance were evaluated using existing water demands.

This chapter also includes recommended improvements for addressing deficiencies identified from the evaluations. Improvement projects are incorporated into the recommended capital improvement program (CIP) detailed in Chapter 9.

The following sections of this chapter present the evaluation methodology and results from the existing water system evaluation:
• Existing Water Demands by Pressure Zone
• Existing Supply/Treatment Capacity Evaluation
• Existing Storage Capacity Evaluation
• Existing Pumping Capacity Evaluation
• Existing Water System Performance Evaluation
• Summary of Findings and Recommended Improvements

6.1 EXISTING WATER DEMANDS BY PRESSURE ZONE
The water demands used for the existing water system evaluation are summarized by pressure zone in Table 6-1 below. To obtain an accurate spatial distribution of demands by pressure zone, water meter consumption data from 2022 were spatially located in GIS. Water meters that are not directly served from the City’s potable water system, such as the Willotta Oaks residences, were excluded. The task of spatially locating water meters and associated demand was completed as part of the City’s 2023 hydraulic model update, which was a separate effort conducted in parallel with this PUMP.

The spatially located water demand was scaled to match the annual average day production in 2020.

However, this scaling excluded the City’s largest customer, Anheuser-Busch. Anheuser-Busch’s demand was updated to directly reflect its actual consumption in 2020 of 0.8 mgd (585 gpm). As discussed in Section 3.1.1 Water Production, the City’s total production significantly increased in 2020 relative to other years due to the COVID-19 pandemic. To be conservative, 2020 was chosen as the baseline production year to represent existing average day demand for the City for the purposes of evaluating capacity and performance, as presented in this chapter. As shown in Table 6-1, the City’s system-wide existing average day demand is 19.6 mgd (13,629 gpm).

Maximum day and peak hour demands were calculated using the pressure zone-specific peaking factors presented in Section 3.1.5 Peaking Factors. As shown in Table 6-1, the City’s estimated system-wide maximum day demand is 37.6 mgd (26,211 gpm) and the system-wide peak hour demand is 47,090 gpm.

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Table 6-1. Summary of Existing Water Demands by Pressure Zone Pressure Zone
Average Day
Demand(a)
Maximum Day
Demand(b) Peak Hour Demand(c)
gpm mgd gpm mgd gpm mgd
Zone 1
1 (excluding Anheuser-Busch) 9,900 14.3 18,810 27.1 29,700 N/A Anheuser-Busch 585 0.8 585 0.8 878 N/A
Subtotal - Zone 1 10,485 15.1 19,395 27.9 30,578 N/A
Zone 2
Southbrook 77 0.1 154 0.2 385 N/A
Red Top 185 0.3 740 1.1 1,480 N/A
Mangels 155 0.2 310 0.4 775 N/A
Paradise/Rolling Hills/Martin
Hill 1,797 2.6 3,594 5.2 8,985 N/A
Goldridge 241 0.3 482 0.7 1,205 N/A
Subtotal - Zone 2 2,455 3.5 5,280 7.6 12,830 N/A
Zone 3
Eastridge 50 0.1 100 0.1 250 N/A
Rancho/Sanctuary 560 0.8 1,120 1.6 2,800 N/A
Subtotal - Zone 3 610 0.9 1,220 1.7 3,050 N/A
Zone 4
4 74 0.1 296 0.4 592 N/A
Zone 5
5 5 < 0.1 20 < 0.1 40 N/A
Total 13,629 19.6 26,211 37.6 47,090 N/A
(a) Existing baseline average day demand (ADD) is based on 2020 production data. The spatial distribution of demand (i.e., what zone it belongs to) is based on 2022 water meter data.
(b) The following zone-specific peaking factors were used to calculate maximum day demand (MDD): Zone 1 = 1.9 x ADD; Anheuser-Busch = 1.0 x ADD; Southbrook, Mangels, Paradise/Rolling Hills/Martin Hill, Goldridge, Eastridge, Rancho/Sanctuary = 2.0 x ADD; Red Top, Zone 4, Zone 5 = 4.0 x ADD. Refer to Chapter 3 (Table 3-6) for more details about the peaking factors. (c) The following zone-specific peaking factors were used to calculate peak hour demand (PHD): Zone 1 = 3.0 x ADD; Anheuser-Busch =

1.5 x ADD; Southbrook, Mangels, Paradise/Rolling Hills/Martin Hill, Goldridge, Eastridge, Rancho/Sanctuary = 5.0 x ADD; Red Top, Zone 4, Zone 5 = 8.0 x ADD. Refer to Chapter 3 (Table 3-6) for more details about the peaking factors. gpm = gallons per minute; mgd = million gallons per day

6.2 EXISTING SUPPLY/TREATMENT CAPACITY EVALUATION
As described in Section 2.3.1 Water Treatment Plants, the City’s raw water supply is treated at either the Waterman WTP or the NBR WTP. The recommended planning criteria used to evaluate the adequacy of the City’s existing supply/treatment capacity were previously presented in Section 5.2.2 Water Supply Capacity.

As described in that section, the firm supply/treatment capacity of 40.5mgd for both water treatment plants combined should be sufficient to meet the City’s system-wide maximum day demand of 37.6 mgd, as

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presented in Table 6-1 above. The results of the water supply/treatment capacity evaluation are presented in Table 6-2 below and indicate that the City has a supply/treatment capacity surplus of 2.9 mgd.

Table 6-2. Water Treatment Capacity Evaluation - Existing Water System(a) Waterman WTP
Firm Capacity(b),
mgd
[A]
NBR WTP Firm
Capacity(c),
mgd
[B]
Total Firm Supply
Capacity,
mgd
[C] = [A] + [B]
Demand
Requirement(d),
mgd
[D]
Supply Capacity
Surplus (Deficit),
mgd
[E] = [C] - [D]

25.0 15.5 40.5 37.6 2.9
(a) Assumes non-emergency operating conditions during a high demand period (maximum day). (b) Firm capacity for Waterman WTP is defined as 100 percent of the actual performance capacity. According to City staff, the actual performance capacity is 25 mgd (out of 30 mgd total rated capacity). (c) Firm capacity for NBR WTP is defined as 90 percent of the actual performance capacity. According to City staff, the actual performance capacity is 32 mgd (out of 40 mgd total rated capacity). Only 90 percent of that performance capacity is assumed to be reliable (i.e., 0.9 x 32 mgd) because NBR WTP is the largest of the two WTPs. Assuming a lesser capacity accounts for regular maintenance that may occur and unanticipated service disruptionssuch as equipment failure. From there, the capacity allocated to Vacaville (13.3 mgd) is subtracted. (d) Equal to system-wide maximum day demand (refer to Table 6-1). mgd = million gallons per day
It should be noted that the results shown in Table 6-2 assume non-emergency operating conditions, but they do consider regular maintenance and account for unanticipated service disruptions such as equipment failure. As described in Section 5.2.2 Water Supply Capacity, in the event of an emergency, the goal of the City’s water system is to provide the greater of either:

1. Four hours of peak hour demands (equal to approximately 11.3 mgd); or

2. One day of maximum day demand with the largest possible fire of 6,000 gpm for 6 hours (equal to approximately 39.8 mgd total).

This emergency requirement can be met through a combination of firm water treatment capacity and available reservoir storage capacity. As indicated in Table 6-2 above, the City has a firm water treatment capacity of 40.5 mgd. In addition, as presented previously in Section 2.3.2 Storage Reservoirs (refer to Table 2-4), the City has a system-wide nominal storage capacity of 78.5 MG. Supply from the combination of these two sources is greater than the largest emergency requirement of 39.8 mgd, indicating that the City is equipped to meet emergency supply/treatment capacity requirements. Therefore, no supply/treatment capacity improvements are recommended for the existing water system.

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6.3 EXISTING STORAGE CAPACITY EVALUATION
Water storage provides operational flexibility to balance temporary differences in supply and demand, such as during a peak hour demand condition, as well as to provide emergency supply during fires or supply outages. To evaluate the City’s existing storage capacity, the storage available in each of the City’s pressure zones was compared to the recommended storage capacity goal for each pressure zone. As described in Section 5.3.2 Storage Reservoir Capacity, the City’s recommended storage capacity goal includes three components:

1. Operational storage: equal to 25 percent of maximum day demand for each zone

2. Fire storage: equal to the largest fire flow demand in a pressure zone multiplied by the required duration

3. Emergency storage: equal to two times average day demand for each zone Four of the City’s pressure zones are smaller zones that are served by hydropneumatic tanks, so they do not contain their own storage reservoirs. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. To evaluate these pressure zones, their storage capacity needs were assumed to be supported by the storage reservoirs within the pressure zone that serves them. For example, since Zone 5 is supplied by Zone 4, the storage reservoir in Zone 4 was assumed to be available to meet the storage capacity requirements of Zone 5, in addition to those of Zone 4. Table 6-3 presents the results of the storage capacity evaluation and indicates that there are no storage capacity deficits in any of the City’s pressure zones.

It should be noted that within Zone 1, there are hydraulic limitations associated with conveying water from available storage to meet system demands. Most of the water demands in Zone 1 (nearly 60 percent) are located southeast of Interstate 80 (I-80) and north of California State Route 12 (SR 12), referred to herein as the Zone 1 Eastern Area of Influence. Conveyance across these highways is limited to 10 locations where existing water pipelines cross the highways, which limits the amount of water that can be conveyed from storage in the west to support demands in the east. Based on the spatial distribution of demands, approximately 60 percent of the Zone 1 storage shown in Table 6-3 (i.e., 60 percent of 40.7 MG, or approximately 24 MG) is needed to support the Zone 1 Eastern Area of Influence. However, only Cement Hill Reservoir is available to directly support that area, with 10 MG of available storage. City staff have indicated that during the summer when the NBR WTP is offline, Cement Hill Reservoir drains significantly faster than the other Zone 1 storage reservoirs. The City is currently working on strengthening its pipeline network across I-80 and SR 12 through a water pipeline freeway crossing project (CIP ID CPW090070), which is included in Chapter 9.

Table 6-3. Water Storage Capacity Evaluation - Existing Water System Operational(b)
[B]
Fire Flow(c)
[C]
Emergency(d)
[D]
Storage Capacity
Requirement
[E] = [B] + [C] + [D]
Zone 1 and Supported Zones
1 Waterman
Cement Hill
Nelson Hill
Eastridge
South Cordelia

53.0 7.0 30.2
2 - Southbrook N/A (hydro) 0.0 0.1 0.2
2 - Red Top N/A (hydro) 0.0 0.3 0.6
3- Eastridge N/A (hydro) 0.0 0.03 0.2
Zone 2
Mangels Mangels 1.0 0.1 0.2 0.4 0.7 0.3
Paradise/Rolling
Hills/Martin Hill
Paradise Valley
Rolling Hills
Martin Hill

17.8 1.3 2.2 5.2 8.7 9.1
Goldridge Goldridge 2.2 0.2 1.1 0.6 1.9 0.3
Zone 3
Rancho/Sanctuary Rancho Solano 3 3.1 0.4 1.1 1.6 3.1 0.0 Zone 4 and Supported Zone
4 Rancho Solano 4 1.4 0.1 0.2
5 N/A (hydro) 0.0 0.0 0.0
(a) Refer to Table 2-4 for available storage capacity.
(b) Operational storage is defined as 25 percent of maximum day demand for each zone. (c) Fire storage is equal to the largest fire flow requirement in the zone multiplied by the required fire flow duration. (d) Emergency storage is defined as two times average day demand for each zone.

MG = million gallons; hydro = pressure zone is served by a hydropneumatic tank.

Required Storage Capacity, MG
Available Storage
Capacity(a), MG
[A]
Storage Reservoirs
Pressure Zone Available
Existing Storage
Capacity Surplus or
(Deficit), MG
[F] = [A] - [E]

1.1 1.4 0.0

2.2 40.7 12.3
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6.4 EXISTING PUMPING CAPACITY EVALUATION
As described in Section 5.3.1 Pump Station Capacity and Backup Power, there are several different criteria that need to be considered when evaluating pumping capacity. These criteria are summarized below:
• Available Pumping Capacity
— Rather than assuming the total capacity of a pump station is available at all times, a reduction in pumping capacity is assumed (i.e., firm pumping capacity). Firm pump station capacity is defined as the total operational pump station capacity with the largest pump out of service, not including the fire pump, which is always assumed to be operational. The City has fire pumps at all hydropneumatic zone pump stations, except Red Top Pump Station, which was being upgraded at the time of this PUMP. — Both the nominal design capacity1 and the measured flow capacity2 of each pump station are considered. The smaller of the two capacities is assumed in the pumping capacity evaluation.
• Required Pumping Capacity
— The recommended required pumping capacity varies depending on whether the pressure zone being evaluated is supported by a storage reservoir(s). ▪ Each pressure zone with storage must be supplied by one or more pump stations that together provide firm capacity equal to the maximum day demand of the pressure zone.
▪ Each pressure zone without storage must be supplied by one or more pump stations with a firm capacity equal to the larger of either:
o The maximum day demand in the pressure zone plus the largest potential fire flow that could occur in the pressure zone; or
o The peak hour demand in the pressure zone.
— Pump stations located in lower pressure zones should be sized with sufficient firm capacity to serve all pressure zones located above them. ▪ For example, when evaluating the pumping capacity of Zone 4, the combined firm capacities of the two pump stations that supply Zone 4 (i.e., Rancho Solano 4 and Sanctuary 4) must be sufficient to meet the demand requirements of both Zone 4 and Zone 5. This is because Zone 4 is the only supply source for Zone 5.

To evaluate the City’s existing pumping capacity, the available firm pumping capacity of each of the City’s pressure zones was compared to the recommended pumping capacity requirement for that pressure zone. Table 6-4 presents the results of the pumping capacity evaluation and indicates that there is a firm pumping capacity surplus in all pressure zones except for Red Top (Zone 2), Mangels (Zone 2), and Eastridge (Zone 3). The Red Top (Zone 2) firm pumping capacity deficit is a known issue, and this pump 1 Refer to Table 2-5 of this PUMP for nominal design capacity. 2 Refer to Table 2-2 (Pump Operation versus Nameplate Ratings) in the Potable Water Pump Station Asset Management Plan Update Report prepared for the City of Fairfield (West Yost, April 2023) for measured flow capacity.

Table 6-4. Pumping Capacity Evaluation - Existing Water System Pressure Zone Supply Sources
Zone Contains
Storage?(a)
Design - Firm
Pumping
Capacity(b,c), gpm
[A]
Measured Flow -
Firm Pumping
Capacity(b,d), gpm
[B]
Assumed Firm
Pumping Capacity(e),
gpm
[C] = MIN ([A], [B])
Required
Pumping
Capacity(f), gpm
[D]
Existing Pumping
Capacity Surplus or
(Deficit), gpm
[E] = [C] - [D]
Zone 1
1 Waterman WTP

NBR WTP
Yes 45,700 -- 45,700 26,211 19,489
Zone 2
Southbrook Southbrook 1 PS
Southbrook 2 PS No 4,300 3,140 3,140 1,654 1,486
Red Top(g) Red Top PS(h) No 1,160 -- 1,160 5,240 (4,080) Mangels Mangels PS Yes 360 292 292 310 (18)
Paradise/Rolling
Hills/Martin Hill
Paradise Valley PS
Rolling Hills PS
Martin Hill PS
Yes 8,400 5,601 5,601 3,594 2,007
Goldridge(i) Goldridge PS Yes 3,000 2,816 2,816 482 2,334 Zone 3
Eastridge Eastridge 3 PS No 1,610 1,594 1,594 1,600 (6) Rancho/Sanctuary Rancho Solano 3 PS
Sanctuary 3 PS
Yes 2,685 1,783 1,783 1,436 347
Zone 4
4 Rancho Solano 4 PS
Sanctuary 4 PS
Yes 797 656 656 316 340
Zone 5
5(j) Rancho Solano 5 PS No 175 140 140 40 100
(a) For zones with storage, the pumping capacity requirement is equal to the maximum day demand. For zones without storage, the pumping capacity requirement is equal to the larger of:
(1) maximum day demand plus fire flow, or (2) peak hour demand. (b) Firm pumping capacity assumes the largest pump would be offline at each pump station unless station is serving a hydropneumatic pressure zone and contains a fire pump, in which case the second largest pump after the fire pump is assumed to be offline. (c) The design capacity is from Table 2-5 of this PUMP. (d) The measured flow capacity is from the City's Potable Water Pump Station Asset Management Plan Update (West Yost, April 2023). (e) Minimum value between Design and Measured Flow - Firm Pumping Capacity. (f) Required pumping capacity reflects the fact that some pump stations must be able to support zones above the one they immediately serve. For example, Zone 1 pump stations should be able to supply system-wide demands, Rancho Sanctuary (Zone 3) pump stations should be able to supply Zone 4 and Zone 5 demands, and Zone 4 pump stations should be able to supply Zone 5 demands.
(g) Red Top fire flow requirement (4,500 gpm) is based on the fire flow requirement documented in the Red Top Replacement Zone II Pump Station Basis of Design Report (Creegan & D'Angelo, 2017).
(h) At the time of this PUMP report, the Red Top pump station was in the process of being replaced. The available pumping capacity included in this table does not reflect the replacement pump station. (i) Goldridge fire flow requirement (4,500 gpm) is based on the fire flow requirement documented in the Canon Station Zone II Pump Station and Reservoir Basis of Design Report (Creegan & D'Angelo, 2017).
(j) Zone 5 does not have a fire flow requirement because it does not contain active fire hydrants; the required pumping capacity is equal to the peak hour demand for the zone. gpm = gallons per minute
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station was planned for replacement at the time of this PUMP3. For Mangels (Zone 2) and Eastridge (Zone 3), the firm pumping capacity deficiencies are very minor and are due to the measured flow capacity being less than each pump station’s nominal design capacity. Since the nominal design capacity meets the pumping capacity requirement for both pressure zones, it is recommended that the City perform rehabilitation on the pumps at these pump stations, so they can pump at their intended capacities.

6.4.1 Existing System Backup Power
Critical pumping facilities should be equipped with an onsite backup power generator. A pumping facility is considered critical if it provides service to a pressure zone that does not have sufficient emergency storage available, in addition to meeting several other criteria as described in Section 5.3.1 Pump Station Capacity and Backup Power.

Since all the City’s pressure zones with storage meet the recommended storage capacity requirement, only zones served by hydropneumatic tanks that do not contain their own storage reservoirs were further evaluated. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. As previously presented in Section 2.3.3 Pump Stations (refer to Table 2-5) the largest pump station that supplies each of these pressure zones is already equipped with backup power. Therefore, no backup power improvements are recommended for the existing water system.

6.5 EXISTING WATER SYSTEM PERFORMANCE EVALUATION
The objective of the water system performance evaluation is to identify improvements that may be needed to support the City’s existing water demands while meeting the recommended performance criteria presented in Section 5.2 Water System Performance. The following scenarios were modeled to assess water distribution system performance under existing water demand conditions:
• Peak Hour Demand Scenario: This scenario evaluated service pressures during a peak hour demand condition.
• Maximum Day Demand plus Fire Flow Scenario: This scenario evaluated fire flow availability under a maximum day demand condition.

As previously discussed, the City’s water system hydraulic model was updated in 2023 as part of a separate effort conducted in parallel with this PUMP. The model update included the following: (1) spatially locating demands based on 2022 water meter data; and (2) adding new pipelines to the model to reflect updates made to the City’s GIS since the completion of the previous model update in 2020. The model was originally built and calibrated in 2018.

Following the demand and pipeline updates, West Yost updated controls and settings throughout the hydraulic model based on schematics and discussions with City staff. The updates reflect operational changes made by the City since the completion of the Cross Town Transmission Pipeline in 2019. The updates mostly included changing the control settings for the City’s thirteen control valve vaults to generally move water west through the Cross Town Transmission Pipeline, which is how the City typically operates the system during a maximum day demand (summer) condition. In addition, settings on the 3 For more details, refer to the Red Top Replacement Zone II Pump Station Basis of Design Report (Creegan + D’Angelo Infrastructure Engineers, February 2017).

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City’s seventeen PRVs were also updated to 40 psi, except for the Peabody Road PRV, where the bypass was kept open and the Cordelia Road PRV, which was set at 74 psi.

Once the hydraulic model was updated, it was used to conduct the existing water system performance evaluation. It should be noted that the City’s hydropneumatic zones4 have not been calibrated in the City’s hydraulic model and were therefore excluded from the following performance evaluation.

6.5.1 Peak Hour Demand
The hydraulic model was used to conduct a steady-state analysis of the City’s water system during an existing peak hour demand condition. Areas that cannot meet the recommended target pressure criteria (45 to 120 psi) are further assessed to see whether improvements are warranted.

Under this scenario, water supply was assumed to come from the City’s water treatment plants, with approximately 14 mgd supplied from Waterman WTP and 23 mgd supplied from NBR WTP. This distribution of supply is consistent with existing water system operations described by City staff during a maximum day demand condition. Additional supply needed beyond maximum day demand to support the peak hour (approximately 31 mgd) was assumed to come from storage reservoirs.

Results from the existing peak hour demand scenario are presented on Figure 6-1 and indicate that the City’s existing water system meets the minimum and maximum pressure criteria during the peak hour at virtually all customer service locations. As shown on Figure 6-1, no locations rise above the City’s maximum target service pressure of 120 psi. The highest observed pressure is 115 psi, which occurs in a lower elevation (84 feet) area of the Mangels (Zone 2) pressure zone.

There are six locations that drop below the 45 psi target minimum pressure goal during the peak hour, which are labeled Locations 1 through 6 on Figure 6-1. These deficiencies and recommendations to address them are summarized in Table 6-5. It should be noted that the target minimum pressure goal of 45 psi exists to help the City provide a high level of service. However, the City’s actual minimum pressure requirement is 40 psi, and even that pressure is well above the minimum pressure of 20 psi required to meet health and safety standards. As shown in Table 6-5, improvements are recommended at Locations 3, 4, 5, and 6 to meet the City’s goal of 45 psi minimum service pressure. Since all of these locations, with the exception of Location 5, are greater than the City’s requirement of 40 psi, improvements to address pressures below 45 psi could be omitted if desired at locations 3, 4, and 6. 4 Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5.

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Table 6-5. Summary of Peak Hour Demand Results - Existing Water System Location Findings and Recommendations
1 • Low pressures of 42-43 psi are slightly below the City's target minimum pressure of 45 psi. • Low pressures are due to elevations that are higher than the target service elevation range for Zone 2.
• This area cannot be easily served from a different pressure zone. • Due to minor deficiency, no improvements are recommended. 2 • Low pressure of 44 psi is slightly below the City's target minimum pressure of 45 psi. • Low pressure is due to elevation that is higher than the target service elevation range for Zone 3. • This area cannot be easily served from a different pressure zone. • Due to minor deficiency, no improvements are recommended. 3 • Low pressures of 40-45 psi occur at the boundary between Zone 2 and Zone 3 due to the pressure reducing valve (Del Monte PRVZ-3) being set at 45 psi near elevations that are higher than the valve.
• If the PRV setting was increased to 47 psi, the low pressures would be mitigated. • It is recommended that the City consider increasing the setting of the Del Monte PRVZ-3 to mitigate low pressures in this area.
4 • Low pressure of 43 psi occurs at the boundary between Zone 1 and Zone 2 due to a gate valve that is closed between the pressure zones.
• It is recommended that the City consider moving the pressure zone break to another valve located slightly southwest.
• Services at Location 4 may experience pressures greater than 80 psi if they were served from Zone 2, so individual pressure regulators may be needed, per CPC requirements. • Alternatively, to mitigate this deficiency, the City could increase supply from the Waterman WTP through changing the setting on the east valve (no CIP project needed). 5 • The lowest observed pressure (33 psi) during the peak hour occurs along Knoll Drive. • This is an area of known low pressures that is located outside of the Zone 1 service elevation boundary. At the developer’s request, the City allowed a connection to Zone 1 in this area without requiring a pump station based on the developer’s acceptance of lower pressures and other mitigations provided by the developer such as larger water service sizes. • It is recommended that the City consider moving the Bridle Ridge Drive PRV east to Suisun Valley Road, which would allow the Knoll Drive neighborhood to be served from Mangels (Zone 2) instead of Zone 1.
• If this change is implemented, pressures within the Knoll Drive neighborhood may rise to greater than 80 psi, so individual pressure regulators may be needed, per CPC requirements. 6 • Low pressure of 44 psi is slightly below the City's target minimum pressure of 45 psi. • Low pressures are due to elevations that are higher than the target service elevation range for Zone 1.
• This area cannot be easily served from a different pressure zone. • To mitigate this deficiency, the City could increase the supply from the Waterman WTP through the east valve.

Notes:

1. Existing peak hour demand for the City is 67.9 mgd (refer to Chapter 6 for details).

2. Hydropneumatic zones were not evaluated in the hydraulic model. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. 80 80
80 680
12 12
12 Prepared by: Prepared for:

Figure 6-1
WEST YOST - N:\Clients\268 Fairfield\60-22-20 Water Master Plan\GIS\MXD\Fig6-1_ExPeakHour.mxd - wjones - 11/8/2024 0 7,000 14,000
Feet
City of Fairfield
Public Utility Master Plan
Existing System Peak Hour Pressure
Peak Hour Pressure
Less than 20 psi (None)
20 - 40 psi
40 - 45 psi
45 - 60 psi
60 - 80 psi
80 - 120 psi
Greater than 120 psi (None)
Pipeline
Pressure Zones
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
0 2,000 4,000
Meters
Location 5 (multiple points)
Zone 1
Pressure = 33 - 37 psi
Elevation = 139 - 148 ft
Location 4
Zone 1
Pressure = 43 psi
Elevation = 101 ft
Location 3 (multiple points)
Zone 2
Pressure = 40 - 44 psi
Elevation = 182 - 192 ft
Location 2
Zone 3
Pressure = 44 psi
Elevation = 314 ft
Location 1 (multiple points)
Zone 2
Pressure = 42 - 43 psi
Elevation = 209 - 212 ft
Location 6
Zone 1
Pressure = 44 psi
Elevation = 106 ft
Highest Pressure
Zone 2
Pressure = 115 psi
Elevation = 84 ft

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6.5.2 Maximum Day Demand Plus Fire Flow
Results from a fire flow simulation indicate whether a system can provide adequate fire flow protection, even under high demand conditions (i.e., during a maximum day demand condition). The hydraulic model was used to conduct a steady-state fire flow analysis of the City’s water system during an existing maximum day demand condition. Areas that cannot meet the City’s minimum fire flow target of 1,500 gpm for existing buildings are further assessed to see whether improvements are warranted. The minimum fire flow target is further discussed in Chapter 5 Water System Evaluation Criteria.

The City’s hydraulic model uses Autodesk InfoWater Pro software, which contains a specific module for simulating fire flow evaluations. For this evaluation, Infowater’s fire flow module was run within the hydraulic model to determine the fire flow available at each junction location, while maintaining a minimum residual pressure of 20 psi at the junction itself, as well as at all customer locations throughout the system. For the City’s hydraulic model, junctions are included at each fire hydrant location currently shown in the City’s GIS.

For this evaluation, water supply was assumed to come from the City’s existing surface water treatment plants, with approximately 14 mgd supplied from Waterman WTP and 23 mgd supplied from NBR WTP.

This distribution of supply is consistent with existing water system operations described by City staff during a maximum day demand condition. It was further assumed that all storage reservoirs were approximately half full and all upper zone pump stations were assumed to be off, to confirm that fire flow can be supplied from the storage reservoirs only.

Results from the maximum day demand plus fire flow evaluation are presented on Figure 6-2 and indicate that most of the City’s water system can provide more than 6,000 gpm of available fire flow, particularly in Zone 1. As shown on Figure 6-2, there are two locations that don’t meet the minimum fire flow target of 1,500 gpm at 20 psi. These deficiencies are summarized in Table 6-6. As shown in Table 6-6, no improvements are recommended.

Table 6-6. Summary of Maximum Day Demand Plus Fire Flow Results - Existing Water System Location Findings and Recommendations
1 • Deficiency is due to being located in a higher elevation area that experiences lower static pressure (40 – 50 psi).
• Deficiency will not be fully mitigated through a larger diameter pipeline because of the higher elevation.
• Location can meet more than 80 percent of the 1,500 gpm fire flow requirement (1,270 gpm) and the requirement can be met at adjacent locations along the pipeline loop. • Due to minor deficiency, no improvements are recommended. 2 • Deficiency is due to an 8-inch diameter dead-end pipeline. • The location can meet more than 90 percent of the 1,500 gpm fire flow requirement (1,430 gpm) and the requirement can be met at adjacent locations along the main pipeline loop. • Due to minor deficiency, no improvements are recommended.

N
otes:

1.Theavailablefireflowateachjunctionisthemaximumflowavailablewhile maintaining20psiresidualsystempressure.

2.Availablefireflowrepresentsdistributionsystemcapacityatthepipelinemain, anddoesnotaccountforlossesthroughlateralsorhydrantassembly.

3.Evaluationwasconductedduringamaximumdaydemandcondition.Existing maximumdaydemandfortheCityis37.6mgd(refertoChapter6fordetails).

4.Hydropneumaticzoneswerenotevaluatedinthehydraulicmodel.Thisincludes Southbrook(Zone2),RedTop(Zone2),Eastridge(Zone3),andZone5. 80 80
80 680
12 12
12 Preparedby:Preparedfor:

Figure6-2
WEST YOST - N:\Clients\268 Fairfield\60-22-20 Water Master Plan\GIS\MXD\Fig6-2_ExFFAvail.mxd - wjones - 11/13/2023 07,00014,000F
eet
CityofFairfield
PublicUtilityMasterPlan
ExistingSystemAvailableFireFlow
AvailableFireFlow
Lessthan1,500gpm
1,500-4,500gpm
4,500-5,000gpm
5,000-6,000gpm
Greaterthan6,000gpm
Pipeline
PressureZones
Zone1
Zone2
Zone3
Zone4
Zone5
02,0004,000
Meters
Location2
Zone2
Flow=1,430gpm
Pipe=8-inch(dead-end)
Location1
Zone1
Flow=1,270-1,370gpm
Pipe=8-inch

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6.6 SUMMARY OF FINDINGS AND RECOMMENDED IMPROVEMENTS
Findings and recommended improvements for the City’s existing water system are summarized in Table 6-7, and recommended capital improvements are highlighted in bold text. These recommendations are used to develop a recommended CIP, which is further discussed in Chapter 9.

Table 6-7. Summary of Findings and Recommendations - Existing Water System Evaluation Category Findings and Recommendations
Supply/Treatment Capacity • No deficiencies identified. • No improvements are recommended.

Storage Capacity
• There are hydraulic limitations associated with moving water from storage to support demands across I-80 and SR 12 in the Zone 1 Eastern Area of Influence.
• These limitations will be addressed as part of the project associated with CIP ID CPW09007 included in the City’s projected capital budget.

Pumping Capacity
• Red Top Pump Station has a firm pumping capacity deficiency. • This deficit will be addressed through construction of a larger pump station (in progress).
• The nominal design capacity of the Mangels and Eastridge Pump Stations meet the firm pumping capacity requirements, but their measured flow capacities do not.
• It is recommended that the City rehabilitate the pumps at these stations to return them to their intended capacities.

Water System Performance:

Peak Hour Demand
• Low pressures observed at Location 3 on Figure 6-1.
• It is recommended that the City consider increasing the setting of the Del Monte PRVZ-3 to 47 psi to mitigate low pressures experienced at the Zone 2 / Zone 3 boundary.
• Low pressures observed at Location 4 on Figure 6-1.
• It is recommended that the City consider moving the pressure zone break to another valve located slightly southwest. The valve currently closed is labeled WGV-10766 in the City’s GIS. If this is done, services that move from Zone 1 to Zone 2 may experience pressures greater than 80 psi and require individual pressure regulators to be installed. Alternatively, the City could increase the supply from the Waterman WTP through the east valve. • Low pressures observed at Location 5 of Figure 6-1.
• It is recommended that the City consider moving the Bridle Ridge Drive PRV east to Suisun Valley Road, which would allow the Knoll Drive neighborhood to be served from Zone 2 instead of Zone 1. If this is done, services that move from Zone 1 to Zone 2 may experience pressures greater than 80 psi and require individual pressure regulators to be installed. • Low pressures observed at Location 6 on Figure 6-1.
• To mitigate this deficiency, the City could increase the supply from the Waterman WTP through the east valve.

Water System Performance:

Maximum Day Demand
Plus Fire Flow
• Only minor deficiencies identified.
• No improvements are recommended.

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6.7 REFERENCES
Creegan + D’Angelo Infrastructure Engineers, 2017. Canon Station Zone II Pump Station and Reservoir Basis of Design Report.

Creegan + D’Angelo Infrastructure Engineers, 2017. Red Top Replacement Zone II Pump Station Basis of Design Report.

West Yost, 2023. Potable Water Pump Station Asset Management Plan Update Report prepared for the City of Fairfield.

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CHAPTER 7
Future Water System Evaluation
This chapter evaluates the City’s future water system and its ability to support the projected near-term (2030) and long-term (2050) demands while meeting the recommended planning and performance criteria defined in Chapter 5 of this PUMP. Both system capacity (i.e., treatment, storage, and pumping) and hydraulic performance were evaluated using projected future water demands.

This chapter also includes recommended improvements for addressing any deficiencies identified from the evaluations. Improvement projects are incorporated into the recommended CIP detailed in Chapter 9.

The following sections of this chapter present the evaluation methodology and results from the future water system evaluation:
• Future System Description
• Future Water Demands by Pressure Zone
• Future Supply/Treatment Capacity Evaluation
• Future Storage Capacity Evaluation
• Future Pumping Capacity Evaluation
• Future Water System Performance Evaluation
• Summary of Findings and Recommended Improvements

7.1 FUTURE WATER SYSTEM DESCRIPTION
As described in Chapter 3, the City has many future residential and non-residential development projects which are expected to be built by 2050. For the future system evaluation, those future projects were assumed to come online according to the timing estimated for each project: either by the near-term timeframe, which is assumed to occur at 2030, or by the long-term timeframe, which is assumed to occur at 2050. The timing and location of each future development area is illustrated on Figure 7-1.

As shown on Figure 7-1, most of the future project development areas are estimated to come online within the long-term timeframe (between 2030 and 2050) and are primarily located in Zone 1. For the two Specific Plan areas, the TSSP and the HOFSP, half the development is estimated to come online by the near-term timeframe, and the remaining half by the long-term timeframe. Two long-term projects, the Rancho Solano Opportunity Site and the Nelson Hill Opportunity Site, are located at elevations that are higher than the typical service elevation range of the pressure zone they are adjacent to. It is anticipated that these two areas will be served from new pressure zones in the future and the associated water system facilities to serve each area will be identified at a later time to be funded by the developer. No future development projects are planned in the following pressure zones: Southbrook (Zone 2), Mangels (Zone 2), Zone 4, and Zone 5.

Anheuser-Busch, the City’s largest customer, has a water supply contract with the City that entitles them to 3.1 mgd, and for the purposes of the future system evaluation, it is assumed they will be operating at that full contract amount by the near-term timeframe. The demand assumptions for Anheuser-Busch are further described in the next section. In addition, any distribution system infrastructure improvements that have already been planned for by the City were assumed to be online by the near-term timeframe (refer to list below). These planned improvements, along with the City’s existing facilities, represent the baseline future water system network for the purposes of the future system evaluation.

Notes:

1. The location and timing of potential
future projects is based on the City of
Fairfield General Plan Update
Alternatives Report (Dyett & Bhatia,
October 2021), as well as discussions
with City staff. Some projects are
potential intensified redevelopment
areas, as further explained in Chapter 3.

2. Within the Train Station Specific Plan
Area and the Heart of Fairfield Specific
Plan Area, 50 percent of development
and resulting water demands are
assumed to be in place by 2030.

3. Anheuser-Busch is assumed to take
its full contract amount (3.1 mgd) by
the near-term (2030) timeframe.

4. Refer to Chapter 7 for details about the
infrastructure improvement projects
shown.

5. Due to their high elevations, new
pressure zones will likely be needed
to support the Rancho Solano and
Nelson Hill Opportunity Sites.
80 80
80 680
12 12
12 Prepared by: Prepared for:

Figure 7-1
WEST YOST - N:\Clients\268 Fairfield\60-22-20 Water Master Plan\GIS\MXD\Fig7-1_FutureSystem.mxd - wjones - 11/11/2024 0 3 6
Kilometers
0 2 4
Miles
City of Fairfield
Public Utility Master Plan
Potential Areas of
Future Development
Near-Term (2030) Pump
Station
Near-Term (2030) Valve
Near-Term (2030) WTP
Existing Pipeline
Near-Term (2030) Pipeline
Near-Term (2030) Project
Long-Term (2050) Project
Project With 50 Percent
Developed by Near-Term
(2030)
Pressure Zones
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Train Station
Specific
Plan
Hale Ranch Road
Transmission Main
Replacement
Red Top
Pump Station
Replacement
Canon Station
Transmission Main
Canon Station
Pump Station
& Reservoir
Heart of Fairfield
Anheuser-Busch
Operating at
Full Contract Amount
Nelson Hill
Opportunity Site
Elev. 20 - 320 feet
(New Pressure Zone)
Rancho Solano
Opportunity Site
Elev. 180 - 780 feet
(New Pressure Zone)
Peabody PRV

NBR WTP
Rehabilitation
Waterman WTP
Rehabilitation

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As shown on Figure 7-1, the water distribution system infrastructure improvement projects currently planned for by the City and assumed to be completed by the near-term timeframe include:
• Red Top Pump Station Replacement – This project includes plans to replace the existing Red Top Pump Station so it can better serve existing and future customers in Red Top (Zone 2).

The proposed design would increase the firm pumping capacity into Red Top (Zone 2) to 5,700 gpm. The inlet pipeline to the pump station would also be upsized from 12-inch to 16-inch diameter.1
• Canon Station Pump Station and Reservoir – This project would provide a new supply source to the TSSP area and includes construction of two separate 2.0 MG tanks (for a total storage capacity of 4.0 MG), as well as a new pump station with a firm capacity of 7,400 gpm.
2 The existing customers within the TSSP area are currently served from Goldridge (Zone 2). After the completion of this project, they would be served from the new Canon Station Pump Station and Reservoir, although the area will remain hydraulically connected to Goldridge (Zone 2), as discussed in subsequent sections. • Peabody PRV Upgrade – This project would upgrade the existing Peabody PRV (10-inch diameter) and bypass pipeline (12-inch diameter) to a 16-inch diameter MOV. • Hale Ranch Road Transmission Main Replacement – This project proposes to upsize approximately 2,600 feet of 24-inch diameter pipeline along Hale Ranch Road to 36-inch diameter. According to the City’s 2024/2025 capital improvement project list, the project has been allocated funding and design is expected to begin in the second quarter of 2025. • Canon Station Transmission Main – This project completes an approximately 1,100-foot gap in the 30-inch diameter transmission pipeline that currently exists along the northern boundary of the Canon Station area within the TSSP. It’s anticipated that the transmission pipeline will be completed soon, as Planning Areas 4 and 5 of the TSSP area continue to be built out.
• Waterman WTP Rehabilitation – For the purposes of the future system evaluation, this water treatment plant is assumed to be rehabilitated to its rated capacity of 30 mgd. • NBR WTP Rehabilitation – For the purposes of the future system evaluation, this water treatment plant is assumed to be rehabilitated to its rated capacity of 40 mgd. 1 For more details, refer to the Red Top Replacement Zone II Pump Station Basis of Design Report (Creegan + D’Angelo Infrastructure Engineers, February 2017).
2 For more details, refer to the Canon Station Zone II Pump Station and Reservoir Basis of Design Report (Creegan + D’Angelo Infrastructure Engineers, May 2017).

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7.2 FUTURE WATER DEMANDS BY PRESSURE ZONE
Future demands used in the water system evaluation were developed based on projected development areas as discussed in Chapter 3. The future water demands for each new development project were first spatially located in ArcGIS to determine which pressure zone would provide supply. Then the future demands were added to existing baseline demands (described in Chapter 6) to develop projected near-term and long-term water demands. The City’s future water demands for near-term and long-term timeframes are summarized in Table 7-1 and Table 7-2, respectively.

The near-term and long-term water demand projections assume that Anheuser-Busch is operating at its full contract amount (3.1 mgd) without peaking under maximum day or peak hour demand conditions.

The current peak hour demand at Anheuser-Busch is approximately 1.3 mgd, which is less than half of the full contract amount. Since future operations at this facility are not expected to use significantly more water in the future, and peak water use may not coincide with the water system’s peak hour demand, it is sufficient to assume Anheuser-Busch’s water use for both the maximum day and peak hour demand conditions will not exceed 3.1 mgd.

When the Canon Station Pump Station and Reservoir come online, the Canon Station (Zone 2) area will remain hydraulically connected to Goldridge (Zone 2) and both areas together will be treated as a single pressure zone (i.e., the Goldridge/Canon Station (Zone 2) pressure zone). The analyses presented in this chapter are consistent with this assumption.

As shown in Table 7-1, the City’s near-term system-wide average day demand is 23.8 mgd (16,549 gpm).

This represents a 21 percent increase over existing baseline demands, previously presented in Table 6-1.

As shown in Table 7-2, the City’s long-term system-wide average day demand is 29.0 (20,170 gpm). This represents a 48 percent increase from existing baseline demands previously presented in Table 6-1, and a 22 percent increase from near-term demands. Most of the future demand occurs in Zone 1.

Maximum day and peak hour demands were calculated using the pressure zone-specific peaking factors presented in Section 3.1.5 Peaking Factors. As shown in Table 7-1, the City’s estimated near-term system-wide maximum day demand is 43.8 mgd (30,392 gpm) and the near-term system-wide peak hour demand is 53,165 gpm. As shown in Table 7-2, the City’s estimated long-term system-wide maximum day demand is 54.7 mgd (37,980 gpm) and the long-term system-wide peak hour demand is 66,613 gpm.

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Table 7-1. Summary of Near-Term (2030) Water Demands by Pressure Zone Pressure Zone
Average Day
Demand(a)
Maximum Day
Demand(b)
Peak Hour
Demand(c)
gpm mgd gpm mgd gpm mgd
Zone 1
1 (excluding Anheuser-Busch) 10,886 15.7 20,683 29.8 32,658 N/A Anheuser-Busch(d) 2,153 3.1 2,153 3.1 2,153 N/A
Subtotal - Zone 1 13,039 18.8 22,836 32.9 34,811 N/A
Zone 2
Southbrook 77 0.1 154 0.2 385 N/A
Red Top 189 0.3 756 1.1 1,512 N/A
Mangels 155 0.2 310 0.4 775 N/A
Paradise/Rolling Hills/Martin Hill 1,797 2.6 3,594 5.2 8,985 N/A Goldridge 167 0.2 334 0.5 835 N/A
Canon Station 431 0.6 862 1.2 2,155 N/A
Subtotal - Zone 2 2,816 4.0 6,010 8.6 14,647 N/A
Zone 3
Eastridge 55 0.1 110 0.2 275 N/A
Rancho/Sanctuary 560 0.8 1,120 1.6 2,800 N/A
Subtotal - Zone 3 615 0.9 1,230 1.8 3,075 N/A
Zone 4
4 74 0.1 296 0.4 592 N/A
Zone 5
5 5 < 0.1 20 < 0.1 40 N/A
Total 16,549 23.8 30,392 43.8 53,165 N/A
(a) Near-term average day demand (ADD) is the sum of existing demand and near-term demand. The spatial distribution of future demand (i.e., what zone it belongs to) is based on City's General Plan Update: Alternatives Report (2021). (b) The following zone-specific peaking factors were used to calculate maximum day demand (MDD): Zone 1 = 1.9 x ADD; Southbrook, Mangels, Paradise/Rolling Hills/Martin Hill, Goldridge, Canon Station, Eastridge, Rancho/Sanctuary = 2.0 x ADD; Red Top, Zone 4, Zone 5 = 4.0 x ADD. Refer to Chapter 3 (Table 3-6) for more details about the peaking factors. (c) The following zone-specific peaking factors were used to calculate peak hour demand (PHD): Zone 1 = 3.0 x ADD; Southbrook, Mangels, Paradise/Rolling Hills/Martin Hill, Goldridge, Canon Station, Eastridge, Rancho/Sanctuary = 5.0 x ADD; Red Top, Zone 4, Zone 5 = 8.0 x ADD. Refer to Chapter 3 (Table 3-6) for more details about the peaking factors. (d) For Anheuser-Busch, the maximum contract amount (3.1 mgd) is assumed. gpm = gallons per minute; mgd = million gallons per day; N/A = not applicable.

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Table 7-2. Summary of Long-Term (2050) Water Demands by Pressure Zone Pressure Zone
Average Day
Demand(a)
Maximum Day
Demand(b)
Peak Hour
Demand(c)
gpm mgd gpm mgd gpm mgd
Zone 1
1 (excluding Anheuser-Busch) 13,683 19.7 25,999 37.4 41,050 N/A Anheuser-Busch(d) 2,153 3.1 2,153 3.1 2,153 N/A
Subtotal - Zone 1 15,836 22.8 28,152 40.5 43,203 N/A
Zone 2
Southbrook 77 0.1 154 0.2 385 N/A
Red Top 501 0.7 2,004 2.9 4,008 N/A
Mangels 155 0.2 310 0.4 775 N/A
Paradise/Rolling Hills/Martin Hill 1,952 2.8 3,904 5.6 9,760 N/A Goldridge 167 0.2 334 0.5 835 N/A
Canon Station 788 1.1 1,576 2.3 3,940 N/A
Subtotal - Zone 2 3,640 5.1 8,282 11.9 19,703 N/A
Zone 3
Eastridge 55 0.1 110 0.2 275 N/A
Rancho/Sanctuary 560 0.8 1,120 1.6 2,800 N/A
Subtotal - Zone 3 615 0.9 1,230 1.8 3,075 N/A
Zone 4
4 74 0.1 296 0.4 592 N/A
Zone 5
5 5 < 0.1 20 < 0.1 40 N/A
Total 20,170 29.0 37,980 54.7 66,613 N/A
(a) Long-term average day demand (ADD) is the sum of existing demand, near-term demand, and long-term demand. The spatial distribution of future demand (i.e., what zone it belongs to) is based on City's General Plan Update: Alternatives Report (2021). (b) The following zone-specific peaking factors were used to calculate maximum day demand (MDD): Zone 1 = 1.9 x ADD; Southbrook, Mangels, Paradise/Rolling Hills/Martin Hill, Goldridge, Canon Station, Eastridge, Rancho/Sanctuary = 2.0 x ADD; Red Top, Zone 4, Zone 5 = 4.0 x ADD. Refer to Chapter 3 (Table 3-6) for more details about the peaking factors. (c) The following zone-specific peaking factors were used to calculate peak hour demand (PHD): Zone 1 = 3.0 x ADD; Southbrook, Mangels, Paradise/Rolling Hills/Martin Hill, Goldridge, Canon Station, Eastridge, Rancho/Sanctuary = 5.0 x ADD; Red Top, Zone 4, Zone 5 = 8.0 x ADD. Refer to Chapter 3 (Table 3-6) for more details about the peaking factors. (d) For Anheuser-Busch, the maximum contract amount (3.1 mgd) is assumed. gpm = gallons per minute; mgd = million gallons per day; N/A = not applicable.

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7.3 FUTURE SUPPLY/TREATMENT CAPACITY EVALUATION
The City’s goal for supply/treatment capacity is for the firm capacity of the Waterman WTP and NBR WTP combined to meet the near-term and long-term system-wide maximum day demands that were presented above. Currently, both the City’s water treatment plants operate at a capacity that is less than their rated capacity due to loss of efficiency from age. This reduced performance capacity was assumed for the existing system evaluation. However, for the future system evaluation, it’s assumed that both water treatment plants have been rehabilitated back to their intended rated capacities of 30 mgd for Waterman WTP and 40 mgd for NBR WTP. Further details about the firm capacity supply assumptions for the City are provided in Section 5.2.2 Water Supply Capacity. The results of the near-term and long-term water supply/treatment capacity evaluations are presented in Table 7-3 and Table 7-4, respectively.

Table 7-3. Water Treatment Capacity Evaluation – Near-Term (2030) Water System(a) Waterman WTP
Capacity(b),
mgd
[A]

NBR WTP
Capacity(c),
mgd
[B]
Total Firm Supply
Capacity,
mgd
[C] = [A] + [B]
Demand
Requirement(d),
mgd
[D]
Supply Capacity
Surplus (Deficit),
mgd
[E] = [C] - [D]

30.0 22.7 52.7 43.8 8.9
(a) Assumes non-emergency operating conditions.
(b) Assumes that by 2030 or sooner, Waterman WTP has been rehabilitated to its rated capacity (30 mgd). For Waterman WTP, firm capacity is defined as 100 percent of its rated capacity, since it is the smaller of the two WTPs. This assumption is further described in Section 5.2.2 Water Supply Capacity.
(c) Assumes that by 2030 or sooner, NBR WTP has been rehabilitated to its rated capacity (40 mgd). For NBR WTP, firm capacity is defined as 90 percent of the total capacity (40 mgd). From there, the capacity allocated to the City of Vacaville (13.3 mgd) is removed. These assumptions are further described in Section 5.2.2 Water Supply Capacity. (d) Equal to system-wide maximum day demand (refer to Table 7-1). mgd = million gallons per day
As shown in Table 7-3, there is a surplus of supply for the City of 8.9 mgd and no additional supply is needed for the near-term timeframe. Table 7-3 assumes non-emergency operating conditions. As described in Section 5.2.2 Water Supply Capacity, in the event of an emergency under near-term demand conditions, the goal of the City’s water system is to provide the greater of the two conditions below:

1. Four hours of near-term peak hour demands (equal to approximately 12.8 mgd); or

2. One day of near-term maximum day demand with the largest possible fire of 6,000 gpm for 6 hours (equal to approximately 46.0 mgd total).

This emergency requirement can be met through a combination of firm water treatment capacity and available reservoir storage capacity. As indicated in Table 7-3 above, the City has a firm water treatment capacity at near-term of 52.7 mgd. In addition, as presented previously in Section 2.3.2 Storage Reservoirs (refer to Table 2-2), the City has a system-wide nominal storage capacity of 78.5 MG. That storage capacity is further increased when the Canon Station Reservoirs come online, adding 4.0 MG for a total available storage capacity of 82.5 MG. Supply from the combination of these two sources is greater than the largest emergency requirement of 46.0 mgd, indicating that the City will be equipped to meet near-term emergency supply/treatment capacity requirements. Therefore, no supply/ treatment capacity improvements are recommended for the near-term system.

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Table 7-4. Water Treatment Capacity Evaluation - Long-Term (2050) Water System(a) Waterman WTP
Firm Capacity(b),
mgd
[A]
NBR WTP Firm
Capacity(c),
mgd
[B]
Total Firm Supply
Capacity,
mgd
[C] = [A] + [B]
Demand
Requirement(d),
mgd
[D]
Supply Capacity
Surplus (Deficit),
mgd
[E] = [C] - [D]

30.0 22.7 52.7 54.7 (2.0)
(a) Assumes normal (non-emergency) operating conditions. (b) Assumes that by 2050 or sooner, Waterman WTP has been rehabilitated to its rated capacity (30 mgd). For Waterman WTP, firm capacity is defined as 100 percent of its rated capacity, since it is the smaller of the two WTPs. This assumption is further described in Section 5.2.2 Water Supply Capacity.
(c) Assumes that by 2050 or sooner, NBR WTP has been rehabilitated to its rated capacity (40 mgd). For NBR WTP, firm capacity is defined as 90 percent of the total capacity (40 mgd). From there, the capacity allocated to the City of Vacaville (13.3 mgd) is removed. These assumptions are further described in Section 5.2.2 Water Supply Capacity. (d) Equal to system-wide maximum day demand (refer to Table 7-2). mgd = million gallons per day
As shown in Table 7-4, there is a long-term supply capacity deficit, which indicates that by 2050 an additional 2.0 mgd of supply (or 2.3 mgd of firm capacity) will be needed to support the City’s long-term demands. Recommendations to address this deficit are further described at the end of this section. In addition, as discussed for the near-term system above, emergency conditions should also be evaluated.

In the event of an emergency under long-term demand conditions, the goal of the City’s water system is to provide the greater of the two conditions below:

1. Four hours of long-term peak hour demands (equal to approximately 16.0 mgd); or

2. One day of long-term maximum day demand with the largest possible fire of 6,000 gpm for 6 hours (equal to approximately 56.9 mgd total).

Through utilizing its existing and planned firm water treatment and reservoir storage capacities as described for the near-term system above, the City will be equipped to meet the long-term emergency supply/treatment capacity requirement of 56.9 mgd. Therefore, for the long-term system, improvements are only needed to meet the 2.0 mgd supply deficit during normal operating conditions. To maintain the 10 percent buffer capacity at NBR WTP in the future, a minimum 2.3 mgd of additional capacity is needed.

The improvements to mitigate this deficit are detailed in the technical memorandums (TMs) that were prepared to summarize the condition assessment, performance evaluation, and expansion analysis conducted for the Waterman WTP and NBR WTP, which are presented in Appendices C and D, respectively. The recommended improvements are also included in the City’s CIP, which is presented in Chapter 9. No supply/treatment capacity improvements beyond those listed in Appendices C and D are recommended for the long-term system.

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7.4 FUTURE STORAGE CAPACITY EVALUATION
Water storage provides operational flexibility to balance temporary differences in supply and demand, such as during a peak hour demand condition, as well as to provide emergency supply during fires or supply outages. To evaluate the City’s near-term and long-term storage capacity, the existing and planned storage available in each of the City’s pressure zones was compared to the recommended storage capacity goal for each pressure zone. As described in Section 5.3.2 Storage Reservoir Capacity, the City’s recommended storage capacity goal includes three components:

1. Operational storage: equal to 25 percent of maximum day demand for each zone

2. Fire storage: equal to the largest fire flow demand in a pressure zone multiplied by the required duration

3. Emergency storage: equal to two times average day demand for each zone Four of the City’s pressure zones are smaller zones that are served by hydropneumatic tanks, so they do not contain their own storage reservoirs. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. To evaluate these pressure zones, their storage capacity needs were assumed to be supported by the storage reservoirs within the pressure zone that serves them. For example, since Zone 5 is supplied by Zone 4, the storage reservoir in Zone 4 was assumed to be available to meet the storage capacity requirements of Zone 5, in addition to those of Zone 4.

Table 7-5 and Table 7-6 present the results of the storage capacity evaluation for near-term and long-term conditions, respectively. For the near-term timeframe, there are no storage capacity deficitsin any ofthe City’s pressure zones. Therefore, no storage capacity improvements are recommended for the near-term water system. For the long-term timeframe, there is a storage capacity deficit in Zone 1 of 7.5 MG.3 To alleviate the storage capacity deficit, it is recommended that one or more new storage reservoirs be constructed.

As previously described in Chapter 6, nearly half of the City’s Zone 1 demands are located southeast of I-80 and north of SR 12, referred to herein as the Zone 1 Eastern Area of Influence, while most of the Zone 1 storage reservoirs are located on the opposite side of those highways. Only Cement Hill Reservoir is located southeast of I-80 and north of SR 12, providing 10.0 MG of available storage capacity. Therefore, if a suitable site can be found and acquired, it is recommended that some of the 7.5 MG of new storage capacity be placed southeast of I-80 and north of SR 12 to provide storage redundancy to that area.

The City may also consider siting a portion of the recommended 7.5 MG of new storage within one of the pressure zones supported by Zone 1. As illustrated on Figure 7-1, there is significant future development identified in and around the Red Top (Zone 2) pressure zone, which is currently supported by storage in Zone 1. If these development projects proceed as planned, demands served by Red Top (Zone 2) could more than double by 2050 when compared to existing conditions. Therefore, it may be advantageous to site a new storage reservoir within Red Top (Zone 2). In addition, future development in areas that require the creation of a new pressure zone due to high elevations (e.g., Nelson Hill Opportunity Site) will be supported by storage in Zone 1 once they come online, so it could be advantageous to site some of the recommended new storage in new pressure zone(s). Given all of these possible tank locations, it is recommended that a tank siting study be conducted to determine the most effective location(s) for new storage. 3 The increase in demand assumed for Anheuser Busch equates to approximately 5.0 MG of additional operational and emergency storage capacity needed.

Table 7-5. Water Storage Capacity Evaluation - Near-Term (2030) Water System Operational(b)
[B]
Fire Flow(c)
[C]
Emergency(d)
[D]
Storage Capacity
Requirement
[E] = [B] + [C] + [D]
Zone 1 and Supported Zones
1 Waterman
Cement Hill
Nelson Hill
Eastridge
South Cordelia

53.0 8.2 37.6
2 - Southbrook N/A (hydro) 0.0 0.1 0.2
2 - Red Top N/A (hydro) 0.0 0.3 0.5
3 - Eastridge N/A (hydro) 0.0 0.04 0.16
Zone 2
Mangels Mangels 1.0 0.1 0.2 0.4 0.7 0.3
Paradise/Rolling
Hills/Martin Hill
Paradise Valley
Rolling Hills
Martin Hill

17.8 1.3 2.2 5.2 8.6 9.2
Goldridge / Canon
Station
Goldridge
Canon Station(e) 6.2 0.4 1.1 1.7 3.2 3.0
Zone 3
Rancho/Sanctuary Rancho Solano 3 3.1 0.4 1.1 1.6 3.1 0.0 Zone 4 and Supported Zone
4 Rancho Solano 4 1.4 0.1 0.2
5 N/A (hydro) 0.0 0.01 0.01

2.2 49.2 3.8
(a) Refer to Table 2-4 for available storage capacity.
(b) Operational storage is defined as 25 percent of maximum day demand for each zone. (c) Fire storage is equal to the largest fire flow requirement in the zone multiplied by the required fire flow duration. For Canon Station and Red Top, the fire flow requirement is based on their respective basis of design reports, as further described in Chapter 7.
(d) Emergency storage is defined as two times average day demand for each zone. (e) Canon Station storage reservoir capacity is based on the capacity documented in the Canon Station Zone II Pump Station and Reservoir Basis of Design Report (Creegan & D'Angelo, 2017).

MG = million gallons; hydro = pressure zone is served by a hydropneumatic tank.

Required Storage Capacity, MG
Available Storage
Capacity(a), MG
[A]
Storage Reservoirs
Pressure Zone Available
Near-Term Storage
Capacity Surplus or
(Deficit), MG
[F] = [A] - [E]

1.1 1.4 0.0
N-C-268-60-22-20-E-6-6.2-Chapter 7 Tables (Future)
City of Fairfield
Public Utility Master Plan

Table 7-6. Water Storage Capacity Evaluation - Long-Term (2050) Water System Operational(b)
[B]
Fire Flow(c)
[C]
Emergency(d)
[D]
Storage Capacity
Requirement
[E] = [B] + [C] + [D]
Zone 1 and Supported Zones
1 Waterman
Cement Hill
Nelson Hill
Eastridge
South Cordelia

53.0 10.1 45.6
2 - Southbrook N/A (hydro) 0.0 0.1 0.2
2 - Red Top N/A (hydro) 0.0 0.7 1.4
3- Eastridge N/A (hydro) 0.0 0.04 0.16
Zone 2
Mangels Mangels 1.0 0.1 0.2 0.4 0.7 0.3
Paradise/Rolling
Hills/Martin Hill
Paradise Valley
Rolling Hills
Martin Hill

17.8 1.4 2.2 5.6 9.2 8.6
Goldridge / Canon
Station
Goldridge
Canon Station(f) 6.2 0.7 1.1 2.8 4.6 1.6
Zone 3
Rancho/Sanctuary Rancho Solano 3 3.1 0.4 1.1 1.6 3.1 0.0 Zone 4 and Supported Zone
4 Rancho Solano 4 1.4 0.1 0.2
5 N/A (hydro) 0.0 0.01 0.01
(a) Refer to Table 2-4 for available storage capacity.
(b) Operational storage is defined as 25 percent of maximum day demand for each zone. (c) Fire storage is equal to the largest fire flow requirement in the zone multiplied by the required fire flow duration. For Canon Station and Red Top, the fire flow requirement is based on their respective basis of design reports, as further described in Chapter 7.
(d) Emergency storage is defined as two times average day demand for each zone. (e) Of the 7.5 MG storage deficit, 5.0 MG can be attributed to increases in Anheuser-Busch demand. (f) Canon Station storage reservoir capacity is based on the capacity documented in the Canon Station Zone II Pump Station and Reservoir Basis of Design Report (Creegan & D'Angelo, 2017).

MG = million gallons; hydro = pressure zone is served by a hydropneumatic tank.

2.2 60.5 (7.5)(e)

1.1 1.4 0.0
Pressure Zone
Storage Reservoirs
Available
Available Storage
Capacity(a), MG
[A]
Required Storage Capacity, MG Long-Term Storage
Capacity Surplus or
(Deficit), MG
[F] = [A] - [E]
N-C-268-60-22-20-E-6-6.2-Chapter 7 Tables (Future)
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Public Utility Master Plan
March 2025

7.5 FUTURE PUMPING CAPACITY EVALUATION
As described in Section 5.3.1 Pump Station Capacity and Backup Power, there are several criteria that should be considered when evaluating pumping capacity. These criteria are summarized below. • Available Pumping Capacity
— Rather than assuming the total capacity of a pump station is available at all times, a reduction in pumping capacity is assumed (i.e., firm pumping capacity). Firm pump station capacity is defined as the total operational pump station capacity with the largest pump out of service, not including the fire pump, which is always assumed to be operational. The City has fire pumps at all hydropneumatic zone pump stations. — Both the nominal design capacity4 and the measured flow capacity5 of each pump station are considered. The smaller of the two capacities is assumed in the pumping capacity evaluation.
• Required Pumping Capacity
— The recommended required pumping capacity varies depending on whether the pressure zone being evaluated is supported by a storage reservoir(s). ▪ Each pressure zone with storage must be supplied by one or more pump stations that together provide firm capacity equal to the maximum day demand of the pressure zone.
▪ Each pressure zone without storage must be supplied by one or more pump stations with a firm capacity equal to the larger of either:
o The maximum day demand in the pressure zone plus the largest potential fire flow that could occur in the pressure zone; or
o The peak hour demand in the pressure zone.
— Pump stations located in lower pressure zones should be sized with sufficient firm capacity to serve all pressure zones located above them. ▪ For example, when evaluating the pumping capacity of Zone 4, the combined firm capacities of the two pump stations that supply Zone 4 (i.e., Rancho Solano 4 and Sanctuary 4) must be sufficient to meet the demand requirements of both Zone 4 and Zone 5. This is because Zone 4 is the only supply source for Zone 5.

To evaluate the City’s near-term and long-term pumping capacity, the existing and planned firm pumping capacity of each of the City’s pressure zones was compared to the recommended pumping capacity requirement for that pressure zone at each future planning timeframe. Table 7-7 and Table 7-8 present the results of the pumping capacity evaluation for the near-term and long-term systems, respectively. 4 Refer to Table 2-5 of this PUMP for nominal design capacity. 5 Refer to Table 2-2 (Pump Operation versus Nameplate Ratings) in the Potable Water Pump Station Asset Management Plan Update Report prepared for the City of Fairfield (West Yost, April 2023) for measured flow capacity.

Table 7-7. Pumping Capacity Evaluation - Near-Term (2030) Water System Pressure Zone Supply Sources
Zone Contains
Storage?(a)
Design - Firm
Pumping
Capacity(b,c), gpm
[A]
Measured Flow -
Firm Pumping
Capacity(b,d), gpm
[B]
Assumed Firm
Pumping
Capacity(e), gpm
[C] = MIN ([A], [B])
Required
Pumping
Capacity(f), gpm
[D]
Near-Term Pumping
Capacity Surplus or
(Deficit), gpm
[E] = [C] - [D]
Zone 1
1 Waterman WTP

NBR WTP
Yes 45,700 -- 45,700 30,392 15,308
Zone 2
Southbrook Southbrook 1 PS
Southbrook 2 PS No 4,300 3,140 3,140 1,654 1,486
Red Top(g) Red Top PS No 5,700 N/A
(Future Facility) 5,700 5,256 444
Mangels Mangels PS Yes 360 292 292 310 (18)
Paradise/Rolling
Hills/Martin Hill
Paradise Valley PS
Rolling Hills PS
Martin Hill PS
Yes 8,400 5,601 5,601 3,594 2,007
Goldridge PS Yes 3,000 2,816 2,816 334 2,482
Canon Station PS No(i) 7,400 N/A
(Future Facility) 7,400 5,362 2,038
Zone 3
Eastridge Eastridge 3 PS No 1,610 1,594 1,594 1,610 (16) Rancho/Sanctuary Rancho Solano 3 PS
Sanctuary 3 PS
Yes 2,685 1,783 1,783 1,436 347
Zone 4
4 Rancho Solano 4 PS
Sanctuary 4 PS
Yes 797 656 656 316 340
Zone 5
5(j) Rancho Solano 5 PS No 175 140 140 40 100
(a) For zones with storage, the pumping capacity requirement is equal to the maximum day demand. For zones without storage, the pumping capacity requirement is equal to the larger of:
(1) maximum day demand plus fire flow, or (2) peak hour demand. (b) Firm pumping capacity assumes the largest pump would be offline at each pump station unless station is serving a hydropneumatic pressure zone and contains a fire pump, in which case the second largest pump after the fire pump is assumed to be offline.
(c) The design capacity is from Table 2-5 of this PUMP. (d) The measured flow is from the City's Potable Water Pump Station Asset Management Plan Update (West Yost, April 2023). (e) Minimum value between Design and Measured Flow - Firm Pumping Capacity. (f) Required pumping capacity reflects the fact that some pump stations must be able to support zones above the one they immediately serve. For example, Zone 1 pump stations should be able to supply system- wide demands, Rancho Sanctuary (Zone 3) pump stations should be able to supply Zone 4 and Zone 5 demands, and Zone 4 pump stations should be able to supply Zone 5 demands. (g) Red Top pump station capacity and assumed fire flow requirement (4,500 gpm) is based on the capacity documented in the Red Top Replacement Zone II Pump Station Basis of Design Report (Creegan & D'Angelo, 2017).
(h) Goldridge fire flow requirement (4,500 gpm) and Canon Station pump station capacity and assumed fire flow requirement (4,500 gpm) are based on the capacity documented in the Canon Station Zone II Pump Station and Reservoir Basis of Design Report (Creegan & D'Angelo, 2017). (i) The Canon Station Reservoirs are located at-grade, upstream of the pump station and are therefore unavailable to support the zone during peak hour or a fire. (j) Zone 5 does not have a fire flow requirement because it does not contain active fire hydrants; the required pumping capacity is equal to the peak hour demand for the zone. gpm = gallons per minute; N/A = not applicable.

Goldridge
Canon Station(h)
N-C-268-60-22-20-E-6-6.2-Chapter 7 Tables (Future)
City of Fairfield
Public Utility Master Plan

Table 7-8. Pumping Capacity Evaluation - Long-Term (2050) Water System Pressure Zone Supply Sources
Zone Contains
Storage?(a)
Design - Firm
Pumping
Capacity(b,c), gpm
[A]
Measured Flow -
Firm Pumping
Capacity(b,d), gpm
[B]
Assumed Firm
Pumping
Capacity(e), gpm
[C] = MIN ([A], [B])
Required
Pumping
Capacity(f), gpm
[D]
Long-Term Pumping
Capacity Surplus or
(Deficit), gpm
[E] = [C] - [D]
Zone 1
1 Waterman WTP

NBR WTP
Yes 45,700 -- 45,700 37,980 7,720
Zone 2
Southbrook Southbrook 1 PS
Southbrook 2 PS No 4,300 3,140 3,140 1,654 1,486
Red Top(g) Red Top PS No 5,700 N/A
(Future Facility) 5,700 6,504 (804)
Mangels Mangels PS Yes 360 292 292 310 (18)
Paradise/Rolling
Hills/Martin Hill
Paradise Valley PS
Rolling Hills PS
Martin Hill PS
Yes 8,400 5,601 5,601 3,904 1,697
Goldridge PS Yes 3,000 2,816 2,816 334 2,482
Canon Station PS No(i) 7,400 N/A
(Future Facility) 7,400 6,076 1,324
Zone 3
Eastridge Eastridge 3 PS No 1,610 1,594 1,594 1,610 (16) Rancho/Sanctuary Rancho Solano 3 PS
Sanctuary 3 PS
Yes 2,685 1,783 1,783 1,436 347
Zone 4
4 Rancho Solano 4 PS
Sanctuary 4 PS
Yes 797 656 656 316 340
Zone 5
5(j) Rancho Solano 5 PS No 175 140 140 40 100
(a) For zones with storage, the pumping capacity requirement is equal to the maximum day demand. For zones without storage, the pumping capacity requirement is equal to the larger of:
(1) maximum day demand plus fire flow, or (2) peak hour demand. (b) Firm pumping capacity assumes the largest pump would be offline at each pump station unless station is serving a hydropneumatic pressure zone and contains a fire pump, in which case the second largest pump after the fire pump is assumed to be offline.
(c) The design capacity is from Table 2-5 of this PUMP. (d) The measured flow is from the City's Potable Water Pump Station Asset Management Plan Update (West Yost, April 2023). (e) Minimum value between Design and Measured Flow - Firm Pumping Capacity. (f) Required pumping capacity reflects the fact that some pump stations must be able to support zones above the one they immediately serve. For example, Zone 1 pump stations should be able to supply system- wide demands, Rancho Sanctuary (Zone 3) pump stations should be able to supply Zone 4 and Zone 5 demands, and Zone 4 pump stations should be able to supply Zone 5 demands. (g) Red Top pump station capacity and assumed fire flow requirement (4,500 gpm) is based on the capacity documented in the Red Top Replacement Zone II Pump Station Basis of Design Report (Creegan & D'Angelo, 2017).
(h) Goldridge fire flow requirement (4,500 gpm) and Canon Station pump station capacity and assumed fire flow requirement (4,500 gpm) are based on the capacity documented in the Canon Station Zone II Pump Station and Reservoir Basis of Design Report (Creegan & D'Angelo, 2017). (i) The Canon Station Reservoirs are located at-grade, upstream of the pump station and are therefore unavailable to support the zone during peak hour or a fire. (j) Zone 5 does not have a fire flow requirement because it does not contain active fire hydrants; the required pumping capacity is equal to the peak hour demand for the zone. gpm = gallons per minute; N/A = not applicable.

Goldridge
Canon Station(h)
N-C-268-60-22-20-E-6-6.2-Chapter 7 Tables (Future)
City of Fairfield
Public Utility Master Plan

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As shown in Table 7-7, at the near-term timeframe, there is a pumping capacity surplus in all pressure zones except for Mangels (Zone 2) and Eastridge (Zone 3). These minor deficiencies were previously identified and addressed during the existing system evaluation and those recommendations remain unchanged under near-term conditions.

As shown in Table 7-8, the long-term pumping capacity evaluation results are consistent with the near-term evaluation for all pressure zones except Red Top (Zone 2). By the long-term planning horizon, Red Top (Zone 2) experiences a pumping capacity deficit. Since the evaluation assumes that the future Red Top Pump Station Replacement project is complete, these results indicate that a higher future demand is now projected when compared with the Basis of Design Report for the Red Top Pump Station Replacement project. Therefore, if all future development that is projected to occur within Red Top (Zone 2) proceeds, the pump station may need to be further expanded in the future.

7.5.1 Future System Backup Power
The City’s goal for backup power is for all existing and planned critical pumping facilities to be equipped with an onsite backup power generator. A pumping facility is considered critical if it provides service to a pressure zone that does not have sufficient emergency storage available, in addition to meeting several other criteria as described in Section 5.3.1 Pump Station Capacity and Backup Power.

For the near-term timeframe, all of the City’s pressure zones with storage meet the recommended storage capacity requirement; therefore, only zones served by hydropneumatic tanks that do not contain their own storage reservoirs were further evaluated. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. As previously presented in Section 2.3.3 Pump Stations(refer to Table 2-5), the largest pump station that supplies each of these pressure zones is already equipped with backup power. These results are consistent with the existing system evaluation. Therefore, no backup power improvements are recommended for the near-term water system.

For the long-term timeframe, all of the City’s pressure zones with storage meet the recommended storage capacity requirement, except for Zone 1. It’s anticipated that the City will continue to monitor the build out of Zone 1 to ensure that a storage capacity deficit does not develop with the increased future demands. Assuming that the City is proactive and increases storage before the future demands trigger a storage deficit in Zone 1, no backup power improvements are needed for the long-term water system.

However, if a storage deficit were to develop in Zone 1 by the long-term timeframe, it’s recommended that a permanent onsite backup power generator be installed at the Waterman WTP and/or NBR WTP pump stations that supply Zone 1.

7.6 FUTURE WATER SYSTEM PERFORMANCE EVALUATION
The objective of the future water system performance evaluation is to identify improvements that may be needed to support the City’s future water demands, while meeting the recommended performance criteria presented in Section 5.2 Water System Performance. The following scenarios were modeled to assess water distribution system performance under near-term and long-term water demand conditions:
• Future Peak Hour Demand Scenario: This scenario evaluated service pressures during a peak hour demand condition.
• Future Maximum Day Demand plus Fire Flow Scenario: This scenario evaluated fire flow availability under a maximum day demand condition.

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Future Water System Evaluation
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The hydraulic model was updated to reflect all infrastructure improvement projects assumed to be online in the future, including the following: the new Canon Station Pump Station and Reservoir, the Hale Ranch Road Transmission Main Replacement, the Canon Station Transmission Main, and the Peabody PRV upgrade were all assumed to be in service. The Red Top Pump Station Replacement project was not included because as discussed in Chapter 6, none of the City’s hydropneumatic zones have been calibrated in the City’s hydraulic model (including Red Top) and thus all of them were excluded from the evaluation.

However, the inlet pipeline to the pump station was upsized in the model from 12-inch to 16-inch diameter, consistent with the basis of design report for the Red Top Pump Station Replacement.

In addition, near-term and long-term demands were added to the hydraulic model. Future demands were spatially located, as shown on Figure 7-1, and were assumed to be served by the closest existing City pipeline. When future projects were located at higher elevations, in areas that City staff indicated would be served by a different pressure zone than the adjacent pipeline, all the demand associated with the future project was allocated to the closest pipeline in the pressure zone identified by City staff.

Some future project areas are located at elevations that are outside of the typical service elevation range of the adjacent pressure zone. This includes the Rancho Solano Opportunity Site and the Nelson Hill Opportunity Site shown on Figure 7-1. These areas would be further evaluated during the planning process for development of new pressure zone(s). For the purposes of this evaluation, the future demands associated with those areas were assumed to be served by the adjacent pressure zone (e.g., Zone 1).

Finally, the controls and settings from the existing system evaluation were used as a baseline for the future system evaluation. Updates to facility operations were made as described in the following sections to maximize the ability of the City’s existing and planned water system to meet future demands.

7.6.1 Peak Hour Demand
Peak hour demand represents the single hour throughout the year with the highest system water demand.

The hydraulic model was used to conduct a steady-state analysis of the City’s water system during near-term and long-term peak hour demand conditions. Areas that cannot meet the recommended target pressure criteria (45 to 120 psi) are further assessed to see whether improvements are warranted.

The goal of the City’s water system is to meet the peak hour demand using both production pumping capacity and system storage. Table 7-9 presents the supply assumptions used during the peak hour demand evaluation. As shown in Table 7-9, for both near-term and long-term conditions, supply needed to meet the portion of the peak hour demand equivalent to maximum day demand is assumed to come from the WTPs. Additional supply needed beyond the maximum day demand to support the peak hour is assumed to come from storage reservoirs. For both scenarios, flow out of Waterman WTP was maximized to confirm that transmission pipelines delivering supply from Waterman WTP were sized adequately to meet future peak hour demands.

Chapter 7
Future Water System Evaluation
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March 2025
Table 7-9. Supply and Demand Assumptions - Future Peak Hour Demand Timing
Supply from WTPs
(Maximum Day Demand)(a),
mgd
[A]
Supply from Storage,
mgd
[B]
Peak Hour Demand,
mgd
[C] = [A] + [B]
Near-Term (2030) 44 mgd 33 mgd 77 mgd
Long-Term (2050) 55 mgd 41 mgd 96 mgd
(a) The treated surface water supplied is assumed to be approximately equal to the maximum day demand (refer to Tables 7-1 and 7-2).

For both the near-term and long-term timeframes, the supply from Waterman WTP is assumed to be maximized at 30 mgd, with the remaining surface water supplied from NBR WTP. This does not reflect anticipated operating conditions but was done to confirm the sizing of transmission pipelines delivering supply from Waterman WTP to meet future peak hour demands. mgd = million gallons per day
Results from the near-term and long-term peak hour demand scenarios are presented on Figure 7-2 and Figure 7-3, respectively. As shown on both figures, the City’s existing and planned water system can meet the minimum and maximum pressure criteria during both the near-term and long-term peak hour conditions at virtually all customer service locations. For both scenarios, no locations rise above the City’s maximum target service pressure of 120 psi. The highest observed pressure is 116 psi, which occurs in a lower elevation (84 feet) area of the Mangels (Zone 2) pressure zone. This location is consistent with results from the existing system evaluation.

For the near-term timeframe, there are four locations that drop below the City’s target minimum pressure goal of 45 psi during the peak hour, which are labeled Locations 1 through 4 on Figure 7-2. For the long-term timeframe, the same four locations drop below 45 psi during the peak hour, as shown on Figure 7-3. Only Location 4 drops below the City’s minimum pressure requirement of 40 psi during near-term and long-term conditions. This location was previously identified and addressed during the existing system evaluation. In addition, high velocities in excess of the maximum velocity criterion of 7 fps are observed in the updated 16-inch diameter Peabody PRV Station under near-term and long-term conditions.

These deficiencies and recommendations to address them are summarized in Table 7-10. It should be noted that the target minimum pressure goal of 45 psi exists to help the City provide a high level of service.

However, the City’s actual minimum pressure requirement is 40 psi, and even that pressure is well above the minimum pressure of 20 psi required to meet health and safety standards. As shown in Table 7-10, because the deficiencies are minor, no improvements are recommended for the near-term or the long-term systems.

Notes:

1. Near-Term (2030) peak hour demand for the City is 76.6 mgd (refer to Chapter 7 for details).

2. Hydropneumatic zones were not evaluated in the hydraulic model. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. 80 80
80 680
12 12
12 Prepared by: Prepared for:

Figure 7-2
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Feet
City of Fairfield
Public Utility Master Plan
Near-Term (2030) Peak Hour Pressure
Peak Hour Pressure
Less than 20 psi (None)
20 - 40 psi
40 - 45 psi
45 - 60 psi
60 - 80 psi
80 - 120 psi
Greater than 120 psi (None)
Pipeline
Pressure Zones
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
0 2,000 4,000
Meters
Location 4 (multiple points)
Zone 1
Pressure = 33 - 42 psi
Elevation = 128 - 148 ft
Location 3
Zone 3
Pressure = 44 psi
Elevation = 314 ft
Location 2
Zone 3
Pressure = 44 psi
Elevation = 314 ft
Location 1 (multiple points)
Zone 2
Pressure = 43 - 44 psi
Elevation = 209 - 212 ft
Highest Pressure
Zone 2
Pressure = 116 psi
Elevation = 84 ft
Peabody PRV Station
Zone 1
16-inch Diameter Pipe
Velocity = 9 fps

Notes:

1. Long-Term (2050) peak hour demand for the City is 96.1 mgd (refer to Chapter 7 for details).

2. Hydropneumatic zones were not evaluated in the hydraulic model. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. 80 80
80 680
12 12
12 Prepared by: Prepared for:

Figure 7-3
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Feet
City of Fairfield
Public Utility Master Plan
Long-Term (2050) Peak Hour Pressure
Peak Hour Pressure
Less than 20 psi (None)
20 - 40 psi
40 - 45 psi
45 - 60 psi
60 - 80 psi
80 - 120 psi
Greater than 120 psi (None)
Pipeline
Pressure Zones
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
0 2,000 4,000
Meters
Location 4 (multiple points)
Zone 1
Pressure = 33 - 42 psi
Elevation = 128 - 148 ft
Location 3
Zone 3
Pressure = 44 psi
Elevation = 314 ft
Location 2
Zone 3
Pressure = 44 psi
Elevation = 314 ft
Location 1 (multiple points)
Zone 2
Pressure = 42 - 43 psi
Elevation = 209 - 212 ft
Highest Pressure
Zone 2
Pressure = 116 psi
Elevation = 84 ft
Peabody PRV Station
Zone 1
16-inch Diameter Pipe
Velocity = 12 fps

Chapter 7
Future Water System Evaluation
N-C-268-60-22-20-WP-R-WMP
7-20 City of Fairfield
Public Utility Master Plan
March 2025
Table 7-10. Summary of Peak Hour Demand Results – Near-Term (2030) & Long-Term (2050) Water System
Location Timing Findings and Recommendations
1 • Deficiency occurs for existing,
near-term, and long-term
conditions.
• This location was previously identified and
addressed in Chapter 6.
• No improvements are recommended.
2 • Deficiency occurs for existing,
near-term, and long-term
conditions.
• This location was previously identified and
addressed in Chapter 6.
• No improvements are recommended.
3 • Deficiency occurs for
near-term and long-term
conditions.
• Low pressure of 44 psi is slightly below the
City’s target minimum pressure of 45 psi.
• Low pressure is due to elevation that is higher
than the target service elevation range for
Zone 3.
• This area cannot be easily served from a
different pressure zone.
• Due to minor deficiency, no improvements
are recommended.
4 • Deficiency occurs for existing,
near-term, and long-term
conditions.
• This location was previously identified and
addressed in Chapter 6.
• No improvements are recommended.

Peabody PRV Station
• Deficiency occurs for
near-term and long-term
conditions.
• The City currently keeps the Peabody PRV
closed and allows water to flow freely through
the 12-inch diameter bypass.
• In the future, high velocities are observed at
the Peabody PRV Station along the updated
16-inch diameter pipeline.
• It is recommended that the new Peabody PRV
Station be evaluated for upsizing upon the
end of the valve's useful life to accommodate
future demands.

Chapter 7
Future Water System Evaluation
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March 2025

7.6.2 Maximum Day Demand Plus Fire Flow
Results from a fire flow simulation indicate whether a system can provide adequate fire flow protection, even under high demand conditions (i.e., during a maximum day demand condition). The hydraulic model was used to conduct a steady-state fire flow analysis of the City’s water system during near-term and long-term maximum day demand conditions. Areas that cannot meet the City’s minimum fire flow requirements are further assessed to see whether improvements are warranted.

As discussed in Section 5.2.1 Fire Flow Requirements, the fire flow criteria presented in Table 5-2 include a minimum requirement of 1,500 gpm for single family residential, and a minimum requirement of 2,500 gpm for all other land use types to be developed in the future. Since the fire flow requirements presented in Table 5-2 are only intended to be used to size pipelines that support future development, only junctions adjacent to future development projects were evaluated against the greater of the two fire flow requirements (2,500 gpm).

For this evaluation, Infowater’s fire flow module was run within the hydraulic model to determine the fire flow available at each junction location, while maintaining a minimum residual pressure of 20 psi at the junction itself, as well as at all customer locations throughout the system. For the City’s hydraulic model, junctions are included at each fire hydrant location currently shown in the City’s GIS.

Under both the near-term and long-term scenarios, all storage reservoirs were set at approximately half full and all upper zone pump stations were assumed to be off, to confirm that fire flow can be supplied from storage reservoirs only. The exception was Zone 1, where supply equivalent to the system-wide maximum day demand was assumed to come from the City’s two water treatment plants to supply Zone 1 demands and fill Zone 1 storage reservoirs. This quantity of supply was previously detailed in Column [A] of Table 7-9.

Results from the near-term and long-term maximum day demand plus fire flow evaluation are presented on Figure 7-4 and Figure 7-5, respectively. As shown on both figures, most of the City’s water system can provide more than 6,000 gpm of available fire flow, particularly in Zone 1. For both scenarios, there are two locations that don’t meet the minimum fire flow requirement of 1,500 gpm at 20 psi. Both deficiencies were identified and addressed during the existing system evaluation. As described in Chapter 6, no improvements are recommended.

Notes:

1. The available fire flow at each junction is the maximum flow available while maintaining 20 psi residual system pressure.

2. Available fire flow represents distribution system capacity at the pipeline main, and does not account for losses through laterals or hydrant assembly.

3. Evaluation was conducted during a maximum day demand condition. Near-term (2030) maximum day demand for the City is 43.8 mgd (refer to Chapter 7 for details).

4. Hydropneumatic zones were not evaluated in the hydraulic model. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. 80 80
80 680
12 12
12 Prepared by: Prepared for:

Figure 7-4
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City of Fairfield
Public Utility Master Plan
Near-Term (2030) Available Fire Flow
Available Fire Flow
Less than 1,500 gpm
1,500 - 4,500 gpm
4,500 - 5,000 gpm
5,000 - 6,000 gpm
Greater than 6,000 gpm
Pipeline
Pressure Zones
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
0 2,000 4,000
Meters
Location 1
Zone 1
Flow = 1,390 gpm
Pipe = 8-inch
Location 2
Zone 2
Flow = 1,430 gpm
Pipe = 8-inch (dead-end)

Notes:

1. The available fire flow at each junction is the maximum flow available while maintaining 20 psi residual system pressure.

2. Available fire flow represents distribution system capacity at the pipeline main, and does not account for losses through laterals or hydrant assembly.

3. Evaluation was conducted during a maximum day demand condition. Long-term (2050) maximum day demand for the City is 54.7 mgd (refer to Chapter 7 for details).

4. Hydropneumatic zones were not evaluated in the hydraulic model. This includes Southbrook (Zone 2), Red Top (Zone 2), Eastridge (Zone 3), and Zone 5. 80 80
80 680
12 12
12 Prepared by: Prepared for:

Figure 7-5
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City of Fairfield
Public Utility Master Plan
Long-Term (2050) Available Fire Flow
Available Fire Flow
Less than 1,500 gpm
1,500 - 4,500 gpm
4,500 - 5,000 gpm
5,000 - 6,000 gpm
Greater than 6,000 gpm
Pipeline
Pressure Zones
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
0 2,000 4,000
Meters
Location 1
Zone 1
Flow = 1,390 gpm
Pipe = 8-inch
Location 2
Zone 2
Flow = 1,430 gpm
Pipe = 8-inch (dead-end)

Chapter 7
Future Water System Evaluation
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7-24 City of Fairfield
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March 2025

7.7 SUMMARY OF FINDINGS AND RECOMMENDED IMPROVEMENTS
Findings and recommended improvements for the City’s near-term and long-term water systems are summarized in Table 7-11, and recommended capital improvements are highlighted in bold text. These recommendations are used to develop a recommended CIP, which is further discussed in Chapter 9.

Table 7-11. Summary of Findings and Recommendations – Near-Term (2030) & Long-Term (2050) Water System
Evaluation Category Timing Findings and Recommendations Supply/Treatment Capacity
Near-Term • No deficiencies identified.
• No improvements are recommended.

Long-Term
• There is a 2.3 mgd water supply/treatment
capacity deficit.
• Expansion of the NBR WTP to address this deficit is
further evaluated in Appendix D.

Storage Capacity
Near-Term • No new deficiencies identified.
• No improvements are recommended.

Long-Term
• There is a 7.5 MG storage deficit in Zone 1.
• Recommend installing 7.5 MG of new storage. A tank
siting study is first recommended to determine the
most effective location(s) for the new storage (cost to be paid by developers and excluded from the CIP).

Pumping Capacity
Near-Term • No new deficiencies identified.
• No new improvements are recommended.

Long-Term
• There is an approximately 800 gpm pumping capacity
deficit for Red Top (Zone 2).
• If all future development estimated to occur within
Red Top (Zone 2) area proceeds, the design capacity
for the pump station replacement may need to be
revised, or the pump station may need to be further
expanded between 2030 and 2050 (cost to be paid by
developers and excluded from the CIP).

Water System Performance:

Peak Hour Demand
Near-Term • Only minor new deficiencies identified.
• No new improvements are recommended.

Long-Term
• Velocities through the upgraded Peabody PRV Station
(16-inch diameter pipeline) reach as high as 12 fps by
the long-term timeframe.
• Recommend evaluating the Peabody PRV Station for
upsizing upon the end of the valve’s useful life to
accommodate future demands (not included in the CIP
since replacement is expected after 2050).

Water System Performance:

Maximum Day Demand Plus
Fire Flow
Near-Term • No new deficiencies identified.
• No improvements are recommended.

Long-Term • No new deficiencies identified.
• No improvements are recommended.

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7.8 REFERENCES
Creegan + D’Angelo Infrastructure Engineers, 2017. Canon Station Zone II Pump Station and Reservoir Basis of Design Report.

Creegan + D’Angelo Infrastructure Engineers, 2017. Red Top Replacement Zone II Pump Station Basis of Design Report.

City of Fairfield, 2011. Fairfield Train Station Specific Plan.

City of Fairfield, 2017. City of Fairfield Heart of Fairfield Plan.

Dyett & Bhatia, 2021. City of Fairfield General Plan Update Alternatives Report.

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CHAPTER 8
Condition and Risk Assessments

8.1 INTRODUCTION AND PURPOSE
As part of the City’s Public Utility Master Plan (PUMP), a condition and risk assessment was performed on most of the City’s existing water system infrastructure, which included:
• Two water treatment plants;
• Eight storage reservoirs;
• Sixteen potable water pump stations;
• Two raw water pump stations; and
• Distribution system pipelines and valves (391 miles of pipelines, 353 large diameter transmission and facility valves, and 3,746 large diameter service laterals).

This chapter summarizes the results of the condition and risk assessment and resulting recommendations.

Detailed discussions of the condition and risk assessments for each type of water system infrastructure are provided in separate Technical Memoranda which are included as Appendices C through G. • Appendix C. NBR WTP Condition Assessment, Performance Evaluation, and Expansion Analysis
• Appendix D. Waterman WTP Condition Assessment, Performance Evaluation, and Expansion Analysis
• Appendix E. Water Storage Reservoirs Condition and Risk Assessment • Appendix F. Water Distribution System Condition and Risk Assessment • Appendix G. 2023 Pump Station Asset Management Plan Update Condition assessments were used to develop condition-related improvements, which were then prioritized based on the risk assessment.

8.2 CONDITION ASSESSMENT METHODOLOGY
The condition assessment approach varied for each infrastructure type based on accessibility. For above-ground assets that could be inspected, a visual condition assessment was performed. For below-ground infrastructure such as pipelines and valves, a desktop assessment was performed based on available data.
• Visual condition assessments at pump stations were performed in June 2022 as part of an earlier project, the City’s 2023 Pump Station Asset Management Plan Update (PS AMP). A summary of findings and recommendations from the PS AMP project is included in this chapter for completeness. The full condition and risk assessment is provided in Appendix G. • Visual condition assessments were conducted at key storage reservoirs and both water treatment plants during the months of February and March 2023. The full condition and risk assessment is provided in Appendices C, D, and E.
• A desktop condition assessment was performed in March 2023 on pipelines and valves, utilizing asset age in place of visual-based condition assessment. The full condition and risk assessment is provided in Appendix F.

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All investigations were aided with drawings and documents received by the City and interviews with operation and maintenance (O&M) and engineering staff. Findings from the condition assessment inform the likelihood of failure evaluation as discussed below.

8.3 RISK ASSESSMENT METHODOLOGY
Risk assessment considers the likelihood of failure (LOF) and the consequence of failure (COF) of assets, asset groups (e.g., all check valve assets at one facility are part of the check valve asset group), and facilities. The LOF assesses the probability that an asset or facility will fail to perform at its prescribed service level, and the COF considers the impact resulting from such a failure. The risk score is then determined using a function of LOF and COF scores.

Risk Score = LOF Score x COF Score
The risk assessment approach varied for each infrastructure type based on the level of condition assessment and appropriate roll-up (e.g., assets in a pump station can be aggregated to estimate the risk at the pump station to which they belong). For LOF, the general assessment approach was to start at the lowest reasonable level (asset or asset group). If those assets were part of a larger function (i.e., facility or process area) they were aggregated to calculate the LOF of that larger function. For COF, all assets, asset groups, process areas, and facilities were calculated independently and were not aggregated. Based on this approach each infrastructure type was assessed as follows:
• Pump Stations – assessed at the asset level and rolled up to the facility level to prioritize recommendations relative to other pump stations
• Storage Reservoirs – assessed at the asset groups level as defined above and rolled up to the facility level due to relatively small number of assets at each facility • Water Treatment Plants – assessed at the asset level and rolled up to the treatment process areas to prioritize recommendations relative to other process areas • Pipelines and Valves – assessed at the asset level only because these assets are not concentrated at a specific facility
Once LOF and COF were assessed for each component and a risk score calculated, a risk level, from High to Low, was also assigned using the combination of LOF and COF scores based on a risk level matrix shown in Figure 8-1
1 . The risk level matrix was developed as part of the PS AMP Update project and further updated based on discussion with the City in 2023 and used for all other infrastructure types assessed in the PUMP. The risk levels were set based on engineering judgement and with input from City staff. 1 LOF scoring is described in Section 8.3.1, and COF scoring is described in Section 8.3.2. The COF score is based on two ratings added together so a score of “1” is not possible.

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COF Score
2 3 4 5 6 7 8 9 10
LOF Score
1 2
3 4
5 6
7 8
9 10
Risk Levels Low Medium-Low Medium Medium-High High
Figure 8-1. Risk Levels Matrix
The following sections summarize the methods used to perform the LOF and COF analyses and to determine the resulting risk level for individual assets, asset groups, process areas, and facilities. Detailed LOF and COF criteria for each is provided in the Appendices.

8.3.1 Likelihood of Failure Analysis
The LOF criteria developed for use in the risk assessment was dependent on the facility and type of asset being evaluated. Several factors were considered when establishing LOF criteria, including the ability to observe the assets in the field, and other attribute data available for the asset. The LOF analysis considers three primary failure modes (i.e., how the asset can fail):
• Physical mortality (applicable to all asset types),
• Diminished level of service (applicable to vertical assets); and • Percent LOF (an estimation of LOF provided by Fracta applicable to horizontal assets).

Each failure mode is described in Table 8-1 below.

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Table 8-1. Criteria Used for Asset LOF Evaluation
Failure Mode Applicable Asset Type Description
Physical
Mortality All asset types
• Older assets are more likely to fail than newer ones due to the age of materials and wear from repeated use, and an asset with visible degradation is more likely to fail. While age and condition are often interdependent, newer components may be in poor condition due to environmental conditions or improper
maintenance. Condition ratings are assigned to assets during the on-site condition assessment where possible and based on age where not possible.

Level of
Service Vertical assets only
• An asset that does not perform as designed or intended is a level of service failure. Something does not have to physically happen to the asset for level of service failure to occur.
• Asset performance may affect the level of service provided by the facility, depending on the role of that asset in day-to-day operations. Performance ratings were assigned to assets based on information obtained during the on-site condition assessment and West Yost’s understanding of the water system operations.

Percent
Likelihood of
Failure
Horizontal assets only
• The City had previously undertaken a likelihood of failure analysis with Fracta, Inc., which uses machine learning to develop a condition and risk rating of drinking water distribution pipelines.

Fracta assigns a LOF condition assessment score to every pipe segment based on various risk factors and break history using both City of Fairfield data as well as data available for pipelines with similar environment criteria across the world. After gathering the historical pipe break data, relevant environmental variables are factored into the algorithm such as soil, elevation, proximity to water, railroads and more.
• Fracta’s LOF is the condition assessment score given to each pipeline asset in the water distribution system. It can be interpreted as the percent chance of failure for a pipe. The LOF percentage is the LOF for the next 12 months.

In general, LOF was assessed on a rating scale of 1 to 10 where a high rating indicates poor asset condition and a greater likelihood that the asset or facility will fail to perform at its intended service level. LOF rating definitions are interpreted as shown below for all assets and facilities. • 1 to 2: Unlikely – Like new condition
• 3 to 4: Low – Some minor defects or deterioration, no corrective maintenance history • 5 to 6: Moderate – Average wear, corrective maintenance history exists • 7 to 8: Likely – Above average deterioration; more severe corrective maintenance history; expedite replacement
• 9 to 10: Imminent – Asset fails to meet the desired service level

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8.3.2 Consequence of Failure Analysis
The COF criteria developed for use in the risk assessment considers the impacts that may result from an asset not performing at its required level of service. The COF analysis considers two primary impacts a failure may have on the facility or the system:
• Operating Ability – how failure of the asset or facility affects the rest of the system and ability to maintain service (applicable to all asset types and rated as 1 through 5) • Service Reliability – reliability of service decreases as the time or resources to repair a failed asset increase (applicable to all asset types and rated as 1 through 5) In general, COF was assessed on a rating scale of 2 to 10, using equation 8-1, where a high rating indicates the highest or worst consequence.

COF = COF1 (operating ability) + COF2 (service reliability) (Eqn. 8-1)

8.4 RISK RESULTS
Risk results provide the basis for prioritizing the timing of capital improvements, described in greater detail within Chapter 9. It should be noted that these results do not directly indicate a safety, health, or other risk to the City or its residents, rather, they should be used to assist the City in identifying improvements to be prioritized during capital improvement planning.

8.4.1 Water Treatment Plants
To further aid in prioritization, in addition to assigning a risk level to each individual asset, risk was also assessed for each process area within the treatment plant. The following section provides a summary of the risk results at both the asset level, and the results of categorizing risk at the process or facility level.

Asset LOF and COF was assigned as described in Appendices C and D. For process area LOF, an asset value-weight was assigned to each asset based on its nominal estimated monetary value. This value weighting considers that assets of a higher value or importance (e.g., an ozone generator) will have a greater impact on overall process area LOF than assets of lower value or importance (e.g., a field instrument or sump pump).

The COF of a given process area takes into account the impacts to the WTP should a process area fail. COF factors for each process area were derived in a manner similar to that of the COF factors for individual assets comprising that process. Similar to the COF scoring for assets, process area COF is rated on a 2 to 10 scale.

8.4.1.1 North Bay Regional Water Treatment Plant
Table 8-2 presents a summary of the asset risk assessment ratings. The majority of the NBR WTP assets (59 percent) fall into the Medium risk level. Detailed COF and LOF ratings for each NBR WTP asset are presented in Appendix C.

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Table 8-2. Summary of NBR WTP Asset Risk Assessment Results Risk Level Number of Assets Percent of Total
Low 35 5.9
Medium-Low 90 15.2
Medium 350 58.9
Medium-High 88 14.8
High 31 5.2
Total 594 100%
Figure 8-2 shows the percentage of assets in each process area that fall within each risk level prior to weighting (as represented by the colored bars). The Warehouse Building is composed of approximately 40 percent of assets in the High and Medium-High risk levels, whereas the Post-Ozone process area has no High or Medium-High risk assets.

Figure 8-2. NBR WTP Risk Levels of Assets by Process Area, Percent of Total 0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Percent of Total Number of Assets in Risk Level Per Process Area High Med-High Medium Med-Low Low

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Table 8-3 presents process area LOF score, COF score, risk score, and risk level in order of highest to lowest priority.

Table 8-3. Summary of NBR WTP Process Area Risk Assessment Results Process Area
LOF Score(a)
(value-weighted) COF Score
Risk Score
(weighted)
Risk Level
(Priority)
04 – Flash Mix 5.8 8 46.4 Medium-High
07 – TWPS 6.2 7 43.4 Medium-High
12 – Drying Beds / Pump Stations 6.2 7 43.4 Medium-High 04 – Pretreatment 5.9 7 41.3 Medium-High
05 – Filters 5.6 7 39.2 Medium-High
09 – Blower Building 5.6 7 39.2 Medium-High
02A – Raw Water – PSC 6.0 6 36.0 Medium
10 – Chemicals 5.1 7 35.7 Medium
11 – Washwater Recovery 5.1 7 35.7 Medium
02B – Raw Water – NBA 4.8 6 28.8 Medium
02C – Raw Water – Blending 4.0 7 28.0 Medium
08 – Ozone Gen / LOX 5.5 5 27.5 Medium
01 – Operations Building 4.5 6 27.0 Medium
15 – Spill Containment 6.7 4 26.8 Medium
03 – Pre–Ozone 4.9 5 24.5 Medium
14 – Maintenance Building 6.7 3 20.1 Medium-Low
06 – Post–Ozone 6.3 3 18.9 Medium-Low
00 – Miscellaneous Systems 5.2 3 15.6 Medium-Low
13 – Warehouse Building 5.0 2 10.0 Low
(a) Value weighting considers that assets of a higher value or importance will have a greater impact on overall process area LOF than assets of lower value or importance.

TWPS = Treated Water Pump Station
PSC = Putah South Canal
NBA = North Bay Aqueduct
LOX = Liquid Oxygen

8.4.1.2 Waterman Water Treatment Plant
Table 8-4 presents a summary of asset risk assessment ratings. The majority of the Waterman WTP assets (63 percent) fall into the Medium risk level. Detailed COF and LOF ratings for each Waterman WTP asset are presented in Appendix D.

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Table 8-4. Summary of Waterman WTP Asset Risk Assessment Results Risk Level Number of Assets Percent of Total
Low 0 0
Medium-Low 239 25.5
Medium 586 62.6
Medium-High 91 9.7
High 20 2.1
Total 936 100%
Figure 8-3 shows the percentage of assets in each process area that fall within each risk level prior to weighting (as represented by the colored bars). The Filters process area is composed of approximately 85 percent of assets in the High and Medium-High risk levels, whereas the Control process area has no High or Medium-High risk assets.

Figure 8-3. Waterman WTP Risk Levels of Assets by Process Area, Percent of Total 0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Percent of Total Number of Assets in Risk Level Per Process Area High Med-High Medium Med-Low Low

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Table 8-5 presents process area LOF score, COF score, risk score, and risk level in order of highest to lowest priority.

Table 8-5. Summary of Waterman WTP Process Area Risk Assessment Results Process Area
LOF Score(a)
(value-weighted) COF Score
Risk Score
(weighted)
Risk Level
(Priority)
14 – Filters 6.5 7 45.5 Medium-High
15 – HLPS 6.4 7 44.8 Medium-High
16 – Chemicals 6.1 7 42.7 Medium-High
11 – Intake / LLPS 5.8 7 40.6 Medium-High
60 – Other-ELECT / CONTROLS 6.4 6 38.4 Medium
18 – EQ Basin + Wastewater Pump Station 5.4 7 37.8 Medium 20 – Operations Building 6.2 6 37.2 Medium
12 – Pretreatment 4.9 7 34.3 Medium
19 – Sludge Clarifiers and Lagoons 4.9 7 34.3 Medium
21 – Blowers / Z3PS 4.9 7 34.3 Medium
17 – Ozone Generation 6.3 5 31.5 Medium
13 – Ozone Contact + ICA 5.5 5 27.5 Medium
00 – Misc Systems 6.1 4 24.4 Medium
(a) Value weighting considers that assets of a higher value or importance will have a greater impact on overall process area LOF than assets of lower value or importance .

LLPS = Low Lift Pump Station
EQ = Equalization
ICA = Intermediate Chemical Addition

8.4.2 Storage Reservoirs
A summary of reservoir asset risk assessment ratings is provided in Table 8-6, which lists the total number and percentage of components that fall in each risk level. The majority of the assets (71 percent) fall into the Medium or Medium-Low risk level.

Table 8-6. Reservoir Asset Risk Assessment Results Summary Risk Level Number of Assets Percent of Total
Low 3 3
Medium-Low 39 39
Medium 32 32
Medium-High 24 24
High 2 2
Total 100 100%

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Figure -4 shows the percentage of assets at each reservoir that fall within each risk level (as represented by the colored bars). Eastridge reservoir is composed of approximately 90 percent of assets in the High and Medium-High risk levels, whereas Martin Hill reservoir has no High or Medium-High risk assets.

Figure 8-4. Risk Levels of Assets by Reservoir, Percent of Total Table 8-7 presents the average asset LOF score, COF score, risk score, and risk level in order of highest to lowest priority.
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Cement Hill Eastridge Goldridge Mangels Martin Hill Nelson Hill Rancho Solano 3
Rolling Hills
Percent of Total Number of Components in Risk Level Per Reservoir High Med-High Medium Med-Low Low

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Table 8-7. Summary of Reservoir Risk Assessment Results Reservoir
LOF Score
(average of assets) COF Score Risk Score
Risk Level
(Priority)
Eastridge 7.1 7 49.6 Medium-High
Rancho Solano 3 5.3 6 31.5 Medium
Nelson Hill 4.7 6 28.0 Medium
Goldridge 5.4 5 27.1 Medium
Mangels 4.5 6 27.0 Medium
Cement Hill 5.3 5 26.4 Medium
Rolling Hills 5.5 3 16.4 Medium-Low
Martin Hill 5.5 2 10.9 Medium-Low

8.4.3 Distribution System
Because pipelines and valves are part of a larger system rather than concentrated at a specific facility, risk levels were assigned only at the individual asset level. The distribution system assets included in the risk assessment consists of pipelines ranging from 4 to 48 inches in diameter, service laterals greater than or equal to 3 inches in diameter, and valves greater than and equal to 24 inches in diameter. Risk levels could not be individually assigned to service laterals less than 3 inches in diameter because they were not included in the City’s GIS at the time of this evaluation. Instead, replacement areas for laterals less than 3 inches in diameter were identified based on discussions with City staff. Results are summarized in the subsections below.

8.4.3.1 Pipeline Risk Results
The pipeline risk assessment results are summarized in Table 8-8, which lists the total length and percentage of pipelines that fall in each risk level. The majority of the pipelines (84 percent) fall into the Low or Medium-Low risk levels. The pipeline risk levels are presented spatially in Appendix F.

Table 8-8. Pipeline Risk Assessment Results Summary
Risk Level Length of Pipelines, feet Length of Pipelines, miles Percent of Total Low 940,745 178.2 45.6
Medium-Low 788,872 149.4 38.2
Medium 304,161 57.6 14.7
Medium-High 31,289 5.9 1.5
High - - 0.0
Total 2,065,068 391.1 100%

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8.4.3.2 Service Lateral Risk Results
The service lateral risk assessment results are summarized in Table 8-9, which lists the service laterals (greater than or equal to 3-inches diameter) and percentage of the total that falls in each risk level. The majority of the service laterals (85 percent) fall into the Low or Medium-Low risk levels.

Table 8-9. Service Laterals (≥ 3-inch) Risk Assessment Results Summary Risk Level Count of Service Laterals Percent of Total
Low 1,810 48.3
Medium-Low 1,377 36.8
Medium 546 14.6
Medium-High 13 0.3
High 0 0
Total 3,746 100%

8.4.3.3 Valve Risk Results
The valve risk assessment results are summarized in Table 8-10, which lists the number of valves (greater than and equal to 24-inch diameter) and percentage of the total that falls in each risk level. The majority of the valves (77 percent) fall into the Medium-High or High-risk levels.

Table 8-10. Valve (≥ 24-inch) Risk Assessment Results Summary Risk Level Number of Assets Percent of Total
Low 25 7.1
Medium-Low 18 5.1
Medium 40 11.3
Medium-High 157 44.5
High 113 32.0
Total 353 100%

8.4.4 Pump Stations
A summary of pump station facility risk assessment results (ranked from highest to lowest risk level) is provided in Table 8-11. Figure 8-5 provides further details of where each facility scores in relation to likelihood of failure and consequence of failure.

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Table 8-11. Summary of Pump Station Facility Risk Assessment Results Pump Station
LOF Score(a)
(value-weighted) COF Score
Risk Score
(weighted)
Risk Level
(Priority)
Rancho Solano Golf Course 6.2 5 31 Medium
Eastridge 4.6 6 27.6 Medium
Goldridge Zone 2 3.8 7 26.6 Medium
Rolling Hills 5.2 5 26 Medium
Rancho Solano Raw Water 5.2 5 26 Medium
Rancho Solano Zone 4 5.4 4 21.6 Medium
Upper Mangels Zone 2 4.6 4 18.4 Medium
Sanctuary Zone 3 4.6 4 18.4 Medium
Sanctuary Zone 4 4.6 4 18.4 Medium
Paradise Valley Zone 2 4.2 5 21 Medium-Low
Rancho Solano Zone 5 3.4 6 20.4 Medium-Low
Martin Hill Zone 2 4 5 20 Medium-Low
Rancho Solano Zone 3 3.6 4 14.4 Medium-Low
Southbrook #2 4.7 3 14.1 Medium-Low
Southbrook #1 4.3 3 12.9 Medium-Low
South Cordelia 4.1 2 8.2 Medium-Low
Rancho Solano Zone 4(b) 2 4 8 Low
(a) Value weighting considers that assets of a higher value or importance will have a greater impact on overall process area LOF than assets of lower value or importance.
(b) Rancho Solano Zone 4 (RSZ4) was rehabilitated in 2023.

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Figure 8-5. Pump Station Facility Risk Levels

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8.5 RECOMMENDED IMPROVEMENTS
Condition assessments were performed, when possible, to identify condition-related improvements which were then prioritized based on the risk. For pipelines and valves only a desktop analysis was possible. Summaries of the recommended improvements are outlined below; further detail on prioritization and development of estimated construction cost is provided in Chapter 9 of this report. It should be noted that recommendations for improvements to address performance, operations, and WTP expansion are not included below.

8.5.1 Water Treatment Plants
The NBR and Waterman WTPs were evaluated separately; recommendations for both are outlined below.

8.5.1.1 North Bay Regional Water Treatment Plant
Condition-based improvement recommendations are summarized by process area in Table 8-12.

Table 8-12. NBR WTP - Summary of Condition-Based Capital Improvement Recommendations Process Area Recommended Improvement
01 – Operations Building • Complete in-progress laboratory upgrade • Replace original MCCs 1M and E1M
• Conduct Tier 2 and/or Tier 3 seismic risk assessment(s) to evaluate post-seismic event occupancy capabilities
• Replace original HVAC equipment(a)
• Replace instrument AIT-106A
02A – Putah South Canal Intake
and Metering
• Replace original valves and actuators(a)
• Replace original flow meters
• Replace original HVAC equipment(a)
02B – North Bay Aqueduct
Turnout and Metering
• Repair large diameter existing pipe penetrations to stop leakage • Repair and recoat piping in vicinity of seepage
• Repair or replace corroded galvanized pipe supports
02C – Raw Water Blending • N/A
03 – Pre-Ozonation • Replace original large diameter valves(a) • Replace original MCC-3M
• Address minor corrosion at small diameter stainless steel ozone piping 04 – Pretreatment • Replace original valves at the flash mix area and flocculation basins(a) • Replace original VFDs for flocculation mixers
• Replace original (1988) MCC-4EM
• Replace corroded HVAC straps within the flash mix vault • Replace original redwood baffles in the flocculation basins • Continue regular inspection and reconditioning of original (1988) flocculation mixer and sedimentation basin chain and flight dives; replace equipment when reconditioning ceases to be cost-effective, or effective in maintaining suitable performance

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Table 8-12. NBR WTP - Summary of Condition-Based Capital Improvement Recommendations Process Area Recommended Improvement
05 – Filtration • Replace remaining original large diameter valves(a) • Replace or repair remaining large diameter Victaulic couplings; if replacement gaskets cannot be sourced, switch to alternative takedown coupling style
• Replace original MCC-5EM
• Coat or recoat existing corroded galvanized steel pipe and instrument supports
• Recoat flanged piping hardware (bolt and nuts) at connections dismantled during previous improvement projects
• Identify and eliminate leaking through conduits between filter deck and MCC and spare parts rooms
06 – Post-Ozonation • Replace remaining original large diameter valves(a) • If DDW is amenable to removal, remove existing ozone-related equipment (e.g., ozone destruct units, off-gas blowers, purge blower) and terminate all related electrical, instrumentation and piping connections • Replace original MCCs 6EMA and 6EMB
• Investigate reported corrosion on the torsion bar for the contactor effluent valves
07 – Treated Water Pump
Station
• Replace remaining original large diameter isolation valves (primarily butterfly valves) and gearboxes(a)
• Replace original MCCs 7EM1 and 7EM2
• Continue regular inspection and reconditioning of original (1988) treated water and backwash pumps; replace equipment when reconditioning ceases to be cost-effective, or effective in maintaining suitable performance 08 – Ozone Generation & LOX
Storage
• Conduct Tier 2 and/or Tier 3 seismic risk assessment(s) to evaluate post-seismic event occupancy capabilities
• Replace original MCCs 8M, 8MA, and 8MB
• Replace original HVAC equipment items (generally exhaust fans and hydronic heaters)(a)
• Address minor corrosion at base plates of horizontal LOX storage vessels • Provide restraints for spare parts on shelves in original gas preparation room 09 – Blower Building • Conduct Tier 2 and/or Tier 3 seismic risk assessment(s) to evaluate post-seismic event occupancy capabilities
• Replace original MCCs 9M and 9EM
• Continue regular inspection and maintenance of original positive displacement blowers; replace equipment when maintenance contract ceases to be cost-effective, or effective in maintaining suitable performance. If not before, replace the original blowers as a part of a future NBRWTP expansion, and consider variable speed blowers for replacement units
• Remove existing boiler-related equipment and terminate all related electrical, instrumentation and piping connections

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Table 8-12. NBR WTP - Summary of Condition-Based Capital Improvement Recommendations Process Area Recommended Improvement
10 – Chemicals • Replace original (1988) chemical storage tanks(a) • Replace existing chemical recirculation pumps
• Replace exposed outdoor chemical piping between storage tanks and chemical metering room, including both steel and PVC piping • Provide weather protection structure for outdoor hydrogen peroxide metering pumps
• Replace insulation at outdoor eyewash and shower units • Address corrosion and recoat deck-mounted baseplate for Vanton pump serving chemical spill containment basins
11 – Washwater Recovery • Replace original MCC 11M
• Replace original 500-gpm washwater return pumps; alternatively, conduct periodic inspection and reconditioning to extend the life of the original pumps
• Continue regular inspection and reconditioning of original (1988) 2,000 gpm washwater return pump; replace unit when
reconditioning ceases to be cost-effective, or effective in maintaining suitable performance
12 – Sludge Lagoons • Replace original small-diameter valves(a) 13 – Warehouse Building • Conduct Tier 2 and/or Tier 3 seismic risk assessment(s) to evaluate post-seismic event occupancy capabilities
• Provide restraints for spare parts and equipment stored on shelves Other • Design and construct permanent drainage system for electrical vaults (a) Replacement is recommended during next major process area expansion or modification; in the interim, increase inspection and maintenance frequencies.

MCC = Motor Control Center
HVAC = Heating, Ventilation, and Air Conditioning

8.5.1.2 Waterman Water Treatment Plant
Condition-based improvement recommendations are summarized by process area in Table 8-13.

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Table 8-13. Waterman WTP - Summary of Condition-Based Capital Improvement Recommendations Process Area Recommended Improvement
11 – PSC Intake and Low Lift
Pump Station
• Replace existing PLC 41
• Recoat corroded metallic surfaces at PSC intake (e.g., equipment supports, drum screen shrouds)
• Replace original (1974) drum screen no. 2 at PSC intake(a) • Replace original (1974) washwater pumps at PSC intake(a) • Replace VFDs for LLPS pumps
• Replace original (1974) pump discharge valves at LLPS(a) • Replace LLPS pressure switches and level indicator
• Replace original (1985) LLPS pumps(a)
12 - Pretreatment • Replace existing PLC 51
• Conduct additional evaluation of Flash Mix Pump No. 2 to diagnose cause of vibration
• Repair or replace Actiflo effluent channel sluice gate seal(s) 13 – Ozone Contact and
Intermediate Chemical
Addition
• Conduct Tier 2 or Tier 3 seismic risk assessments to investigate cracking in the ozone contactors
• Modify ozone contactor access hatches to mitigate stripped threads • Replace original (1990) inlet and outlet valves for Ozone Contactors Nos. 3 and 4(a)
• Repair or replace utility crane on west side of contactors • Replace original MCC 2M1
• Replace original (1974) inlet and outlet gates at intermediate chemical addition(a)
14 - Filters • Upgrade existing PLC Allen-Bradley CompactLogix processors and software(a)
• Replace existing motorized valve actuators(a)
• Replace particle counters and differential pressure transmitters • Further assess and seal concrete cracking between Filters 6 and 8, and in filter top slab near wall intersections
• Replace original (1974) filtered water isolation valves (a) 15 – High Lift Pump Station and
Bridge Vault
• Complete planned HLPS improvements project
• Replace bridge vault hatch doors with material suitable for continuous moisture exposure
• Replace original (1974 and/or 1985) valves and remaining original actuators in bridge vault(a)
16 – Chemicals • Upgrade existing PLC45 Allen-Bradley CompactLogix processor and software(a)
• Further assess cracking in CMU walls, and seal cracks against water intrusion
• Apply exterior waterproofing to CMU structure
• Provide anchorage for un-anchored or partially anchored skidded equipment
• Replace original (2010) flow, level, and pressure instruments

Chapter 8
Condition and Risk Assessments
N-C-268-60-22-20-WP-R-WMP
8-19 City of Fairfield
Public Utility Master Plan
March 2025
Table 8-13. Waterman WTP - Summary of Condition-Based Capital Improvement Recommendations Process Area Recommended Improvement
17 – LOX Storage and Ozone
Generation
• Complete in-progress LOX and generation improvements project 18 – Washwater Equalization
Basins and Recycle Pump
Station
• None
19 – Sludge Clarifiers and
Lagoons
• Replace original (2010) turbidimeters and level instruments • Continue periodic coating repairs for carbon steel clarifier mechanisms • Further investigate cracking in sludge clarifier(s) to determine if the cracking extends below the grout topping
20 – Operations Building • Replace original (1990) HVAC air handling units and heat pumps(a) 21 – Blower Building / Zone 3
Pump Station
• Upgrade existing PLC42 Allen-Bradley CompactLogix processor and software(a)
• Replace VFD for Zone 3 Pump No. 1
• Repair leak in roof above MCC room
• Seal cracks in the CMU walls to prevent water intrusion • Apply exterior waterproofing to the CMU walls
Other / Plantwide • Replace all end-of-life and discontinued PLC hardware. Refer to the Waterman WTP “SCADA Cybersecurity Baseline Assessment & Recommendations” report (West Yost, October 2022) for
additional details
• Design and construct means for automatic removal of accumulated water inside susceptible chemical injection or electrical vaults throughout the WTP
(a) Replacement is recommended during next major process area expansion or modification; in the interim, increase inspection and maintenance frequencies.

PLC = Programmable Logic Controllers; MCC = Motor Control Center; HLPS = High Lift Pump Station; CMU = Concrete Masonry Unit; LOX = Liquid Oxygen; VFD = Variable Frequency Drive; HVAC = Heating, Ventilation, and Air Conditioning