Brentwood City Council
May 27, 2025

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includes 1.7 mgd that will still be sourced from RBWTP at a maximum of 100 mg/L of chloride. The City of Antioch has a delivered water quality goal of 75 mg/L for chloride (City of Antioch 2021), and this analysis assumes that the new brackish desalination facility would enable them to meet their delivered water quality goal in the future for all years. The result of the mass balance calculation, as shown in Table 6.14, is an average purchase quantity of 4 mgd (approximately 4,480 AFY) that will result in water quality of approximately 100 mg/L for the Brentwood system.

Table 6.14 Water Quality and Quantity Mass Balance for Average Day Conditions Source Quantity (mgd) Chlorides (mg/L) Percent of Total Volume
Weighted Chlorides
(mg/L)
COBWTP 11.2 110 66.3% 72.9
Antioch Wholesale 4 75 23.7% 17.7
Groundwater 0 225 0.0% 0.0
RBWTP 1.7 100 10.1% 10.1
Total 16.9 100.7
Water quality under max day demand was calculated using the same assumptions of water quality by treatment source. The City of Brentwood can source up to 6 mgd from RBWTP for maximum day demands, and the remaining 24.4 mgd would be a combination of COBWTP and wholesale from the City of Antioch. The mass balance calculations, as shown in Table 6.15, indicate that 7.9 mgd of treated water from the City of Antioch would keep total water quality in the City of Brentwood system below the threshold of 125 mg/L if levels from COBWTP are at 150 mg/L, the highest concentration from COBWTP in 2020 and 2021 (CCWD 2021). The 4,480 AFY is assumed to include fluctuations up to the max day purchase of 7.9 mgd and down to 0 mgd, when water quality in Rock Slough is adequate to meet Brentwood’s target for chloride.

Table 6.15 Water Quality and Quantity Mass Balance for Max Day Conditions Source Quantity (mgd) Chlorides (mg/L) Percent of Total Volume
Weighted Chlorides
(mg/L)
COBWTP 16.5 150 54.2% 81.3
Antioch Wholesale 7.9 75 26.1% 19.5
Groundwater 0 225 0.0% 0.0
RBWTP 6 100 19.7% 19.7
Total 30.4 120.6

6.8.2 Components and Cost Summary
This alternative would require construction of a new conveyance pipeline to connect with Brentwood.

An emergency intertie is currently under construction between the two systems, but the distribution pipes on Antioch’s side are not large enough to accommodate the flow for this alternative. The new conveyance pipeline would be a 20-inch ductile iron pipe approximately 21,100 feet in length. An expansion of the existing COBWTP would not be necessary to meet maximum day demands at buildout,

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as projected in the 2017 Master Plan, based on the supply allocation quantities in Table 6.15. The costs are summarized in Table 6.16.

Table 6.16 Cost Summary for City of Antioch Wholesale Alternative Component Value Notes
Capital Cost
 Conveyance pipeline
$42.2 million Pipeline installation based on $100 per inch-foot; includes urban construction, some dewatering, and contingencies
Annual O&M Costs
 Pipeline maintenance
 COBWTP O&M
$11.0 million Assumed to be 0.5% of capital costs for pipes COBWTP average annual O&M cost over the next 30 years
based on projected demand from 2020 UWMP and
assuming all demand is supplied by COBWTP
Additional Supply from Option
Total Supply Available
Additional Treatment Capacity
from Option
Total Treatment Capacity
Available
4,480 AFY
19,280 AFY
9 mgd

31.5 mgd
Assumes 4 mgd of average day supply
Current ECCID supply allotment plus City of Antioch
wholesale
Assumed maximum day supply available from City of
Antioch
Maximum capacity from City of Antioch of 9 mgd plus 6
mgd maximum day from RBWTP and 16.5 mgd maximum
day from COBWTP
Annualized Capital Costs
Annualized Capital Cost per AF of
Yield from Option
Annual O&M Cost per AF of Yield
from Option
Purchase Price of Water
Total Unit Cost
$1.88 million
$421/AF
$2,459/AF
$1,498/AF
$4,377/AF
30-year financing at 2% interest rate
$1.88 million divided by 4,480 AFY
$11.02 million divided by 4,480 AFY
Based on the City of Antioch’s projected cost of production Annualized capital cost plus annual O&M divided by yield, plus purchase price of water

6.8.3 Benefits
This alternative would provide a relatively high quality of water to Brentwood because the City of Antioch has a delivered water quality goal of 75 mg/L for chloride (City of Antioch 2021), which is lower than Brentwood’s target of 100 mg/L. The City of Antioch has not always been able to meet this goal in the past, but the new brackish desalination facility should improve overall water quality. Therefore, it is assumed the 75 mg/L goal will be achieved in future years. RO treatment is assumed to minimize geosmin and MIB issues as well.

Project implementation would be relatively straightforward in terms of construction and operating the wholesale arrangement. The City of Antioch has sufficient supplies of water through the planning horizon, and construction of the brackish desalination facility will be substantially complete in March

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2025, which means the supply would be reliable during drought and have minimal susceptibility to impacts from climate change. System redundancy would be improved as well because the supply would enter Brentwood’s distribution system in a different location than treated water from COBWTP/RBWTP.

This alternative could provide enough water in conjunction with groundwater to offset a loss of function of the Contra Costa Canal, COBWTP, or the treated water conveyance pipeline connecting COBWTP to the distribution system.

6.8.4 Implementation Challenges, Risks, and Uncertainties This alternative should provide higher quality treated water over Brentwood’s groundwater and surface water supplies but may not resolve the varying water quality experienced by customers throughout the City of Brentwood’s service area if groundwater is still used in conjunction with this alternative. Future increases in salinity in the Delta may force the City of Antioch to source less water from the San Joaquin River and more water from CCWD to meet their water quality goals. This would result in less water being available for wholesale to the City of Brentwood, as CCWD water would not be treated by the City of Antioch on behalf of the City of Brentwood without significant cost increases and would likely require approval from CCWD to convey to Brentwood for final use. The City of Brentwood would not be able to meet max day demands if the City of Antioch cannot supply 7.9 mgd under this option because of lack of treatment capacity.

This alternative may have a place-of-use issue related to the City of Antioch’s water rights that prohibits the City of Antioch from conveying water for sale outside their service area. This analysis assumes the City of Antioch would be allowed to sell water wholesale to the City of Brentwood; however, more investigation would be required to ascertain the legal feasibility of this alternative. While the system integration aspect of implementation for this alternative is relatively straightforward, the potential institutional and legal constraints could prevent this alternative from being viable.

6.9 Reverse Osmosis – Groundwater

6.9.1 Overview
This alternative considers constructing a new treatment facility with RO membrane filtration for advanced treatment of Brentwood’s groundwater supplies. The five active wells within Brentwood are in the northeast corner of the service area near the WWTP. New conveyance pipelines could be installed that would connect the wells to a new RO treatment plant. This RO treatment plant could be sited on City of Brentwood-owned land at Well #6, as shown in Figure 6.7. Preliminary analysis suggests an RO facility could be constructed at that location, but a more detailed site study would be required to ultimately determine suitability and sizing of facilities/infrastructure. The active wells have a current capacity of 5.15 mgd based on information in the 2020 UWMP, and this analysis assumes 5 mgd would be available in all future years. This alternative assumes RO treatment would have a recovery rate of 80 percent, which would result in 4 mgd of permeate and 1 mgd of brine for disposal.

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Figure 6.7 Potential Groundwater Conveyance Alignment to New RO Treatment Facility Pretreatment of groundwater for RO does not require the same level of conventional pretreatment as surface water, so the new RO facility does not need to be located adjacent to COBWTP. However, RO permeate does need to be blended with conventionally treated water before entering the potable distribution system. The permeate could be blended with conventionally treated water at a point in the distribution system where flows are adequate to produce a blend of potable water with sufficient chloride levels. This analysis assumes the connection point would be the 36-inch potable distribution pipe just west of Well #6 on Sunset Road.

Brine disposal is assumed to require conveyance to Delta Diablo for blending with WWTP effluent before disposal through their existing outfall. A conceptual alignment for the brine disposal pipeline would follow Sunset Road west until turning north at Empire Avenue, then west/northwest along Lone Tree Way, where it would mirror the proposed alignment for the City of Antioch brine disposal pipeline, as shown in Figure 6.8. This would require securing easements and/or agreements with the City of Antioch (see Section 6.9.4).

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Figure 6.8 Potential Brine Disposal Pipeline Alignment for RO Groundwater Option

6.9.2 Components and Cost Summary
The main components for this alternative, summarized in Table 6.17, include the new RO treatment facility, a pipeline to connect the wellheads to the new facility, a finished water pump and pipeline, a brine disposal pump and pipeline, and an expansion of COBWTP. An expansion of COBWTP is still necessary under this alternative to meet projected max day demands by buildout.

Capital cost for the RO treatment facility is estimated at $95 million and was based on costs for the City of Antioch’s brackish desalination facility, which were adjusted for the difference in treatment capacity of the facilities. This analysis assumes the brine disposal pipeline would convey brine through Antioch and follow the proposed alignment for the City of Antioch brackish desalination facility brine disposal pipeline to the Delta Diablo WWTP.

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Table 6.17 Cost Summary for RO Treatment of Groundwater Alternative Component Value Notes
Capital Cost
 New RO treatment facility
 Pipeline connecting groundwater
wells to new RO facility
 Pump and pipeline connecting RO
facility to potable distribution
system at suitable location
 Brine disposal pipeline
 Brine disposal pump
 Expansion of COBWTP
$214.1 million
Cost for new RO facility based on capital cost for the City of Antioch brackish desalination facility and scaled down based on difference in treatment capacity
Pipeline installation based on $100 per inch-foot; includes urban construction, some dewatering, and contingencies
Pump costs based on cost curves from the Pumping Station Design manual (Jones and Sanks 2008) and adjusted to January 2023 ENR CCI; pump cost curves based on contract prices for construction plus costs for extra work limited to pump station Land for new RO treatment facility assumed to already belong to the City of Brentwood
Annual O&M Costs
 Maintenance and energy for
pumps and pipes
 COBWTP O&M
 New RO treatment facility O&M
 Brine disposal fee
$14.6 million
O&M assumed to be 0.5% of capital costs for pipes, 1.5% of capital costs for pumps
Energy cost assumed to be 23.3 cents/kWh based on PG&E data for Brentwood’s WWTP in 2022. Quantity of energy for
groundwater extraction based on energy intensity provided in the 2020 UWMP. Quantity of energy for pumping waste brine based on 130 feet of elevation and assumes 1.71 kWh per foot of vertical lift per AF.

RO treatment facility O&M costs based on information from the City of Antioch’s brackish desalination facility
Brine disposal fee assumed to be $60/AF based on assumption used in analysis of brine disposal from the City of Antioch brackish desalination facility
Additional Supply from Option
Total Supply Available
Additional Treatment Capacity from
Option
Total Treatment Capacity Available
4,480 AFY
19,280 AFY

12.25 mgd

34.75 mgd
Based on 5 mgd of groundwater with RO system recovery rate of 80% producing 4 mgd of permeate
Current ECCID supply allotment plus RO permeate from
groundwater
4 mgd of RO permeate and 8.25 mgd from Phase 1 expansion of COBWTP
Includes 6 mgd share of maximum day capacity at RBWTP
Annualized Capital Costs
Annualized Capital Cost per AF of
Yield from Option
Annual O&M Cost per AF of Yield
from Option
Purchase Price of Water
Total Unit Cost
$9.56 million
$2,134/AF
$3,261/AF
$0/AF
$5,395/AF
30-year financing at 2% interest rate
$9.56 million divided by 4,480 AFY
$14.61 million divided by 4,480 AFY
Existing Brentwood supply
Annualized capital cost plus annual O&M divided by yield, plus purchase price of water

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Additional O&M costs include the energy required for pumping groundwater to the surface, pumping to the RO treatment facility, pumping the permeate to a connection point with the rest of the distribution system, and pumping waste brine for disposal to Delta Diablo. Energy costs were based on PG&E rates for Brentwood’s WWTP for 2022 at a rate of 23.3 cents/kWh.

6.9.3 Benefits
Average day demands of 16.9 mgd could be met with 11.2 mgd from COBWTP, the 4 mgd of RO permeate, and 1.7 mgd from RBWTP, with lower concentration of chlorides over existing conditions. The blend of water, as shown in Table 6.18, would result in chloride concentration slightly above 100 mg/L but lower than 125 mg/L even if COBWTP chloride levels are at 150 mg/L (the maximum concentration in recent years).

Table 6.18 Water Quality and Quantity Mass Balance for Average Day Conditions with Groundwater RO Facility
Source Quantity (mgd) Chlorides (mg/L) Percent of Total Volume
Weighted Chlorides
(mg/L)
COBWTP 11.2 150 66.3% 99.4
Groundwater RO 4 1 23.7% 0.2
RBWTP 1.7 100 10.1% 10.1
Total 16.9 109.7
Max day demands could be met with 4 mgd of RO permeate, 6 mgd from RBWTP (current allowable max day treatment capacity), and 16.5 mgd from COBWTP. This would provide 26.5 mgd of treated water, which would meet projected max day demands until approximately 2040. An expansion of COBWTP would be required around 2040 to provide at least 3.9 mgd of additional treatment capacity to reach the

30.4 mgd of projected maximum day demand at buildout, which is 10 years later than the current estimated need for expansion in 2030. The expansion of COBWTP could potentially be avoided altogether if additional treatment capacity could be purchased at RBWTP and CCWD water were allowed to be supplied to all the City of Brentwood’s customers.

Water quality during max day demands would have chloride concentrations of approximately 121 mg/L, assuming chloride at COBWTP is at 150 mg/L, which is above the target of 100 mg/L but below the threshold of 125 mg/L before issues with WWTP effluent arise. Increases above 160 mg/L from COBWTP would push the weighted chloride concentration above 125 mg/L for the potable distribution system.

There is no supplier charge for groundwater. Increased groundwater consumption would allow for a reduction in purchases from CCWD to make greater use of COBWTP, which would offer cost savings.

Conversely, COBWTP could be used slightly less and more water purchased from CCWD if higher quality water is desired. Regardless, it offers more flexibility in the City of Brentwood’s mix of supply.

Availability of groundwater is typically not affected by drought conditions, and there are no immediate concerns about depletion from over-withdrawals of groundwater.

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6.9.4 Implementation Challenges, Risks, and Uncertainties The City of Brentwood would need to determine how to operate and manage the facility from a staffing and administrative standpoint. COBWTP is currently operated by CCWD on behalf of the City under an existing agreement. A new RO treatment facility would require new personnel to be hired to staff the facility and would require the City of Brentwood to either oversee operations internally or find a partner to operate the facility on the City’s behalf.

Brine disposal is a significant issue for this alternative. The City would be required to work with a wastewater treatment provider in the area to find a suitable option for brine disposal. The two options available are Ironhouse Sanitary District (ISD) in Oakley and Delta Diablo in Pittsburg. ISD is currently being analyzed for feasibility of brine disposal from Diablo Water District (DWD) and would likely not be able to accept any more brine. Additionally, ISD is within the Central Valley Regional Water Quality Control Board (RWQCB), where water quality, including salinity of surface water, is a major concern.

Therefore, brine disposal through ISD would likely face significant administrative and legal barriers.

Furthermore, it could risk increasing salinity in the Delta beyond what would occur without the project and negate the benefits from RO treatment of Brentwood’s groundwater.

Brine disposal through Delta Diablo would be less problematic because the outfall for Delta Diablo’s WWTP in Pittsburg is located within the San Francisco Bay RWQCB region, where salinity is less of a concern. However, environmental analysis and permitting could present significant barriers to implementation. Brine would be conveyed to Delta Diablo as a separate waste stream, in accordance with the existing agreement with the City of Antioch and therefore cannot be blended with Antioch’s wastewater flow for dilution before treatment and disposal (Delta Diablo 2020). Furthermore, significant upgrades would be required to Delta Diablo WWTP to accommodate the increased salinity if brine was allowed to be blended with wastewater flows based on the projected quantity of wastewater from the City of Antioch brackish desalination facility. Delta Diablo also uses a portion of treated wastewater for nonpotable reuse, which would be more challenging to accomplish if chloride levels in the effluent were significantly higher.

Therefore, this analysis assumes that brine will be conveyed to Delta Diablo WWTP through a separate brine disposal pipeline for blending with WWTP effluent in the same manner as the City of Antioch’s brine disposal pipeline and that an additional 1 mgd of brine disposal would be permitted.

Availability of groundwater could become an issue in the future, which could limit the volume of groundwater able to be extracted sustainably. Limits to groundwater withdrawals would limit RO permeate available for blending with conventionally treated water and would increase chloride levels in the distribution system as a result. Increasing salinity in the Delta could result in poorer water quality from Rock Slough for treatment at COBWTP and increase the overall chloride level in the distribution system too. Curtailments due to drought could force CCWD to limit deliveries to Brentwood and force more water to be sourced from ECCID through Rock Slough, which would further degrade the quality of the potable water delivered to customers in Brentwood. If any, or all, of these situations were to occur, then Brentwood would be unable to meet water quality goals, despite a significant investment in a potential solution meant to address both water supply and water quality issues.

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Overall system redundancy would not be improved under this alternative because all potable water would come from either COBWTP and/or RBWTP and use the same conveyance pipeline from COBWTP/RBWTP to enter the distribution system. Because RO permeate must be blended before entering the distribution system and no remaining groundwater would be available for blending, this option relies on water from COBWTP to continue supplying water within Brentwood’s service area. RO treatment and groundwater extraction require significant amounts of energy, which results in this alternative having the highest energy intensity compared to all other alternatives.

6.10 Reverse Osmosis – Surface Water

6.10.1 Overview
This alternative considers constructing a new treatment facility with RO membrane filtration for advanced treatment of Brentwood’s surface water supplies from ECCID that are conveyed through the Contra Costa Canal from Rock Slough. The new RO treatment facility would be located adjacent to COBWTP to allow for blending of the RO permeate with conventionally treated water in the COBWTP clearwell before entering the distribution system, as shown in Figure 6.9. This analysis assumes the RO treatment facility will be sized to treat 15 mgd with an 80 percent recovery rate producing 12 mgd of RO permeate and 3 mgd of brine for disposal under maximum operation of the facility. The RO system would consist of three RO trains, each with 5 mgd of capacity producing 4 mgd of permeate and 1 mgd of brine. This configuration would allow for use of the RO system to be scaled up or down according to demands and water quality. Average day conditions would typically use one RO train to meet water quality goals and max day demands would require two or three trains depending on water quality in the Contra Costa Canal.

This alternative would still require an expansion of COBWTP to meet max day demands, as the feed water for the RO treatment system needs pretreatment before entering the RO membranes to maximize efficiency and lifespan of the equipment. Brine disposal is assumed to required conveyance to Delta Diablo WWTP and therefore would require a new pipeline between the RO facility and the WWTP in Pittsburg. The brine disposal pipeline would not be able to be joined with the City of Antioch’s brine disposal pipeline to shorten the overall distance of new pipeline because of differences in pipe size and volume of flow.

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Figure 6.9 Conceptual Location of Potential Surface Water RO Facility at COBWTP Site

6.10.2 Components and Cost Summary
The main components for this alternative, summarized in Table 6.19, include the new RO treatment facility, an expansion of COBWTP, and a brine disposal pipeline. No changes to the intake on the Contra Costa Canal would be required and the existing conveyance capacity for both raw and treated water is sufficient to support this alternative. Additional land would need to be acquired south of COBWTP, as the existing land directly adjacent to COBWTP is already reserved for the expansion of the facility for conventional treatment. The land south of COBWTP is already owned by CCWD, so this analysis does not include land acquisition costs.

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Table 6.19 Cost Summary for RO Treatment of Surface Water Alternative Component Value Notes
Capital Cost
 New RO surface water treatment
facility
 Expansion of COBWTP
 Brine disposal pipeline
 Brine disposal pump
 Land acquisition $445.7 million
Cost for RO facility based on cost for the City of Antioch’s brackish desalination facility and scaled based on the difference in treatment capacity.

Cost of COBWTP expansion based on OPCC from 2017 and
escalated using the January 2023 ENR CCI
Pipeline installation based on $100 per inch-foot; includes urban construction, some dewatering, and contingencies
Land acquisition cost assumption of $100,000 per acre. Assumes 2 acres would be needed for new RO treatment facility. Easement costs are not included.

Annual O&M Costs
 Maintenance and energy for
pumps and pipes
 CCWD conveyance charge
 COBWTP O&M
 New RO treatment facility O&M
 Brine disposal
$14.7 million
O&M assumed to be 0.5% of capital costs for pipes, 1.5% of capital costs for pumps.

Energy cost assumed to be 23.3 cents/kWh based on PG&E rates for Brentwood WWTP in 2022. Quantity of energy for
groundwater extraction based on energy intensity provided in the 2020 UWMP. Quantity of energy for pumping waste brine based on 130 feet of elevation and assumes 1.71 kWh per foot of vertical lift per AF.

O&M costs RO process pumping and chemicals from the City of Antioch’s analysis of brackish desalination facility and escalated using relevant cost indices to January 2023 dollars.

Brine disposal assumed to be $60/AF based on the assumption used in analysis for the City of Antioch’s brackish desalination facility
Additional Supply from Option
Total Supply Available
Average Treatment Volume at
New WTP / Yield from Option
Additional Treatment Capacity
from Option
Total Treatment Capacity Available
0 AFY
14,800 AFY
4,480 AFY

13.5 mgd
36 mgd
Raw water still sourced under existing ECCID agreement
Current ECCID supply allotment
Based on water quality mass balance, which results in 5 mgd of average day RO treatment with RO system recovery rate of 80% producing 4 mgd of permeate
RO treatment facility with 80% recovery produces 12 mgd of permeate from 15 MGD of source water. Expansion of COBWTP provides the pretreatment for the 15 mgd, with 1.5 mgd of remaining capacity from expansion of 16.5 mgd.

Includes 6 mgd share of max day capacity at RBWTP and 16.5 mgd of existing capacity at COBWTP
Annualized Capital Costs
Annualized Capital Cost per AF of
Yield from Option
Annual O&M Cost per AF of Yield
from Option
$19.9 million
$4,442/AF
$3,286/AF
30-year financing at 2% interest rate
$19.9 million divided by 4,480 AFY
$14.72 million divided by 4,480 AFY

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Component Value Notes
Purchase Price of Water
Total Unit Cost
$36/AF
$7,764/AF
Current ECCID rate for raw water
Annualized capital cost plus annual O&M divided by yield, plus ECCID supplier charge
Annual O&M costs were estimated using the same assumptions and methodology as the City of Antioch brackish desalination facility alternative except for pretreatment costs, which were adjusted based on COBWTP O&M costs. O&M also includes a 5-year replacement cycle for RO membranes at $1.7 million per replacement based on cost from the City of Antioch brackish desalination facility and adjusted based on facility treatment capacity and escalated current dollars using the January 2023 ENR CCI.

6.10.3 Benefits
This alternative would offer improved water quality over the conventional treatment process currently used at COBWTP while still making use of the existing supply agreement with ECCID, which minimizes implementation challenges related to water rights and new supply agreements with new partners. The existing ECCID allotment of 14,800 AFY (13.2 mgd) would not be sufficient to meet demands even if the volume of brine disposal were permitted to be subtracted from the total volume of water being diverted.

This alternative would also grant increased flexibility in how much volume of groundwater and treated water from RBWTP are used on a given day; system operators could adjust flows to make increased use of groundwater while minimizing RBWTP flows to minimize purchase cost of water or use less groundwater and more RO treatment if water quality from Rock Slough decreases significantly.

Therefore, this alternative offers an improvement in system reliability in response to drought and/or climate change, as the system can accommodate higher chloride levels and uses ECCID pre-1914 water rights.

6.10.4 Implementation Challenges, Risks, and Uncertainties The City would need to determine how to operate and manage the facility from a staffing and administrative standpoint. COBWTP is currently operated by CCWD on behalf of the City under an existing agreement. A new RO treatment facility would require new personnel to be hired to staff the facility and would require the City of Brentwood to either oversee operations internally or find a partner to operate the facility on the City’s behalf.

Brine disposal is a greater issue for this alternative compared to the groundwater RO treatment.

Brentwood would need to work with either ISD or Delta Diablo. ISD is currently being analyzed for feasibility of brine disposal from DWD and would likely not be able to accept any more brine.

Additionally, ISD is within the Central Valley RWQCB, where water quality, including salinity of surface water, is a major concern. Therefore, brine disposal through ISD would likely face significant administrative and legal barriers.

Brine disposal through Delta Diablo would be less problematic because the outfall for Delta Diablo’s WWTP in Pittsburg is located within the San Francisco Bay RWQCB region, where salinity is less of a concern. However, environmental analysis and permitting could present significant barriers to

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implementation. Brine must be conveyed to Delta Diablo as a separate waste stream, in accordance with the existing agreement with the City of Antioch (Delta Diablo 2020), and therefore cannot be blended with Antioch’s wastewater flow for dilution before treatment and disposal. Furthermore, significant upgrades would be required to Delta Diablo WWTP to accommodate the increased salinity if brine was allowed to be blended with wastewater flows based on the projected quantity of wastewater for the brackish desalination facility. Delta Diablo also uses a portion of treated wastewater for nonpotable reuse, which would be more challenging to accomplish if chloride levels in the effluent were significantly higher. Therefore, this analysis assumes that brine will be conveyed to Delta Diablo WWTP through a separate brine disposal pipeline for blending with WWTP effluent in the same manner as the City of Antioch’s brine disposal pipeline and that an additional 3 mgd of brine disposal would be permitted. However, the implementation of brine disposal under this alternative would face significant barriers from the administrative, environmental permitting and review, and legal perspectives.

Conceptual alignment of the brine disposal pipeline for this alternative is to follow Laurel Road across the Union Pacific railroad tracks, then follow Highway 4 until reaching the location of the proposed City of Antioch brine disposal pipeline and following the same alignment until reaching Delta Diablo WWTP, as shown in Figure 6.10. A conveyance alignment parallel to the Union Pacific tracks would be the shortest distance but would likely present significant implementation, administrative, and legal barriers to overcome given the narrow distance from the railroad tracks to adjacent properties in some locations and potential issues with subterrain construction adjacent to railroad tracks. Coordination and approval from the California Department of Transportation would be required for construction along Highway 4.

Problems with water quality, taste and odor, water appearance/color, and other parameters of water quality may arise, despite RO treatment producing a high-quality finished water. It is not uncommon for fluctuations in overall water chemistry to occur if a dramatic change in steady-state conditions occurs in an aged, mature water distribution system such as introducing a new source of water with different chemical properties from the existing finished water typically found in the distribution system.

Destabilization of mineral and biofilm coating inside distribution system piping can result from these fluctuations, which further threaten water quality (Duranceau 2018). Blending ratios would need to be calculated and refined to account not just for chlorides but a variety of water quality parameter under various scenarios. Consideration for the probability of adverse impacts and identifying potential challenges for addressing each water quality parameter should be evaluated prior to implementation of advanced water treatment processes in existing water distribution systems (Duranceau 2018). Failure to account for potential unintended impacts of advanced water treatment on existing distribution systems could jeopardize all benefits from an expensive solution intended to improve water quality.

Overall system redundancy would not be improved under this alternative because all potable water would come from either COBWTP and/or RBWTP and use the same treated water conveyance pipeline from COBWTP/RBWTP to enter the distribution system. This option relies on continued operation of COBWTP to function as intended because RO treatment requires pretreatment from COBWTP, and RO permeate must be blended with conventionally treated water before entering the distribution system.

Any disruption to supply through the Contra Costa Canal would jeopardize virtually the entire supply for Brentwood. RO treatment requires significant amounts of energy, which results in this alternative having the second-highest energy intensity compared to other alternatives.

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Figure 6.10 Potential Brine Disposal Pipeline Alignment for RO Surface Water Option

6.11 Contra Costa Water District – Raw Water Conveyance to City of Brentwood Water Treatment Plant

6.11.1 Overview
This alternative considers a new raw water conveyance pipeline connecting COBWTP with the raw water pipeline currently supplying RBWTP. The City can only receive treated water from CCWD using the existing share of treatment capacity in RBWTP; there is currently no infrastructure in place that allows raw water to be conveyed to COBWTP. Construction of a new raw water pipeline could connect to the existing raw water pipeline directly west of the RBWTP raw water pump station, as shown in Figure 6.11.

Raw water would flow east before turning north to connect with the existing raw water pipeline connecting the intake on the Contra Costa Canal to the COBWTP raw water pump station. This analysis assumes the City will be allowed to use water purchased from CCWD throughout the City’s entire service area.

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Figure 6.11 Potential Conveyance Alignment for New Raw Water Pipeline Between RBWTP and COBWTP

6.11.2 Components and Cost Summary
The capital costs for this alternative include a new raw water conveyance pipeline, butterfly valves, flow meters, and a CCWD wholesale meter, as shown in Table 6.20. The existing raw water pipe is a 60-inch reinforced concrete cylinder pipe under gravity flow. The new raw water pipeline would be a 30-inch steel pipe, mortar-lined and coated at approximately 2,000 feet of length to account for any site-specific conditions that require deviations to the conveyance alignment. Three 30-inch butterfly valves would be needed to control flow between the Contra Costa Canal, RBWTP, and COBWTP. Two 30-inch flow meters would be needed to accurately measure raw water flow to each treatment plant. It is assumed CCWD would require two flow meters to ensure accuracy and that the City would be responsible for the entirety of the costs. This analysis assumes the City would be required to purchase a 12-inch wholesale meter from CCWD, as well; this wholesale meter would cost of $1.5 million, based on the flow from this option and costs from CCWD’s current Code of Regulations (CCWD n.d.-b). A conveyance charge is included in annual O&M costs, which is assumed to include the demand charge representing wear and tear for CCWD infrastructure.

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Table 6.20 Cost Summary for CCWD Raw Water Conveyance to COBWTP Component Value Notes
Capital Cost
 New raw water conveyance pipeline
 Three 30-inch butterfly valves
 Two 30-inch flow meters
 One 12-inch wholesale retail meter
 Expansion of COBWTP
$106.9
million
Pipeline installation based on $100 per inch-foot; includes urban construction, some dewatering, and contingencies
Costs for valves and flow meters based on recent bid
submission for San Francisco area project and scaled based on capacity
Wholesale meter cost from CCWD based on Code of
Regulations Title 5, Water Supply and Rates, for wholesale municipal customers (CCWD n.d.-b)
Annual O&M Costs
 Maintenance for pipe
 Conveyance charge
 COBWTP O&M
$10.8 million
O&M assumed to be 0.5% of capital costs for pipes
CCWD charges $334 per AF for conveyance assuming same
ratio of conveyance from Rock Slough (67%) and Old River (33%) as the current ratio of conveyance to COBWTP
Additional Supply from Option
Total Supply Available
Additional Treatment Capacity from
Option
Total Treatment Capacity Available
5,600 AFY
20,400 AFY

16.5 mgd
39 mgd
Average daily flow of 5 mgd
Current ECCID supply allotment plus new CCWD supply
Includes 6 mgd share of maximum day capacity at RBWTP
Annualized Capital Costs
Annualized Capital Cost per AF of Yield
from Option
Annual O&M Cost per AF of Yield from
Option
Purchase Price of Water
Total Unit Cost
$4.77 million
$852/AF
$1,935/AF
$1,367/AF
$4,154/AF
30-year financing at 2% interest rate
$4.77 million divided by 5,600 AFY
$10.84 million divided by 5,600 AFY
Current CCWD rate for raw water from Code of Regulations Title 5, Water Supply and Rates for wholesale municipal customers (CCWD n.d.-b)
Annualized capital cost plus annual O&M divided by yield, plus ECCID supplier charge

6.11.3 Benefits
This alternative would give the City greater flexibility in operations and potentially access to higher quality raw water for treatment at COBWTP. System integration would not present significant issues, as the changes in water chemistry are minimal over existing supplies used at COBWTP and in the City’s distribution system, and blending would be relatively simple if needed. The City and CCWD already have a shared interest in the treatment facilities, existing supply agreements, and history of collaboration.

Energy intensity under this alternative would be the same as existing operational conditions for Brentwood at 441 kWh/AF for conveyance, treatment, and distribution.

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System redundancy would be improved under this alternative in a scenario where the COBWTP intake on the Contra Costa Canal is unable to supply ECCID water to the raw water pumping station at COBWTP. Additionally, CCWD would be able to divert raw water from Old River and provide the City with an emergency supply if the Contra Costa Canal itself is unable to provide conveyance of raw water for any reason. The existing water supply agreement between the City and CCWD contains clauses regarding emergency supply should CCWD be unable to provide ECCID water through the Contra Costa Canal. CCWD is obligated to provide water for the customers within the overlapping service areas, but customers outside the overlap in service area are vulnerable to a lack of supply, as CCWD may, but is not required to, provide water for those customers. This alternative would allow the City to ensure that all customers have access to an emergency supply should the Contra Costa Canal be inoperable or otherwise incapable of conveyance because raw water could be conveyed to COBWTP without having to rely on CCWD to provide treatment of a sufficient volume of water for all the City’s customers. However, this may not be necessary, as a proposed change would allow City customers outside the overlapping service areas to receive CCWD water as well.

6.11.4 Implementation Challenges, Risks, and Uncertainties The purchase price of raw water from CCWD has increased significantly in recent years and may continue to increase at a rate greater than cost of living increases in the future, which would increase the cost of this alternative. CCWD is also subject to drought curtailments, which makes this alternative susceptible to changes in climate and future drought events and therefore is not as reliable as the ECCID supply of raw water. System redundancy under this alternative would still be a risk, as it relies on COBWTP to provide most of the potable water and uses a single point of conveyance to the City’s service area.

6.12 Contra Costa Water District – Purchase Additional Capacity at Randall-Bold Water Treatment Plant

6.12.1 Overview
This alternative would pursue an agreement with CCWD to purchase additional treatment capacity at RBWTP. Discussions between CCWD and the City have indicated that 3 mgd of excess capacity may be available for purchase. No additional supply would be acquired through this alternative, as water would continue to be sourced under the existing ECCID supply agreement. Likewise, no additional infrastructure is proposed for construction under this alternative as the existing withdrawal, raw water conveyance, RBWTP, and treated water conveyance infrastructure have sufficient capacity to accommodate this alternative.

6.12.2 Components and Cost Summary
This alternative does not require construction of new treatment capacity at RBWTP or conveyance infrastructure to provide Brentwood with additional treated water. The capital costs are essentially an administrative cost to purchase excess capacity in the existing RBWTP. As such, there are no specific components or costs of the project other than the capital cost of purchasing the right to the treatment capacity from CCWD and the additional O&M costs over existing conditions for conveyance and

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treatment from RBWTP. Capital costs are assumed to be $1.50 per gallon of treatment capacity which equates to $4.5 million for 3 mgd of treatment capacity, as shown in Table 6.21.

Table 6.21 Cost Summary for Purchase of Additional Capacity at RBWTP Component Value Notes
Capital Cost
 Secure rights to an additional 3 mgd
of treatment capacity at RBWTP $4.5 million Based on assumption of $1.50/gallon of capacity purchased.

Annual O&M Costs
 Conveyance
 Volumetric use charge
 RBWTP fixed O&M costs
 RBWTP variable O&M costs (power
and chemicals)
 Increased share of RBWTP Capital
Expenditures
$5.08 million
Conveyance charge based on data from CCWD and assuming
70% of supply from Rock Slough and 30% from Old River.

Volumetric use charge of $2.73 per 1,000 gallons provided by CCWD. RBWTP O&M costs based on RBWTP FY23 budget for
Brentwood’s increased share of capacity under this
alternative. The increased share of RBWTP capital
expenditures is based on Brentwood’s increased share of capacity under this alternative and the average annual
projected capital expenditures for RBWTP from CCWD data.

Additional Supply from Option
Total Supply Available
Additional Treatment Capacity from
Option
Total Treatment Capacity Available
0 AFY
14,800 AFY
3 mgd

25.5 mgd
No additional supply provided by the option
Current ECCID supply allotment
Equates to 3,360 AFY of treated water
Includes current 6 mgd share of maximum day capacity at RBWTP and 16.5 mgd of treatment capacity from COBWTP
Annualized Capital Costs
Annualized Capital Cost per AF of
Treatment from Option
Annual O&M Cost per AF of Treatment
from Option
Purchase Price of Water
Total Unit Cost
$200,925
$60/AF
$1,511/AF
$36/AF
$1,607/AF
30-year financing at 2% interest rate
$200,925 divided by 3,360 AFY
$5.08 million divided by 3,360 AFY
Current ECCID rate for raw water
Annualized capital cost plus annual O&M divided by yield, plus ECCID supplier charge
Annual O&M costs for this alternative include the City’s share of O&M costs for RBWTP, a volumetric use charge levied by CCWD, and conveyance from RBWTP. O&M costs were calculated for the 3 mgd of total capacity purchased under this alternative. Brentwood’s share of O&M costs is based on the FY23 budget for RBWTP which includes fixed and variables costs, plus the average annual cost of RBWTP capital expenditures based on data provided by CCWD. The volumetric use charge is $2.73 per thousand gallons. Conveyance cost is based on assumption of 70 percent of water conveyed from Rock Slough and 30 percent from Old River at a weighted cost of $325/AF. The annual demand charge was not included in the cost estimate for this alternative as Brentwood already pays the annual demand charge under the

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existing agreement for treatment capacity at RBWTP. Increased peak month usage from RBWTP would increase the annual demand charge over current levels but cannot be accurately projected at this time.

6.12.3 Benefits
This alternative would be relatively easy to implement as Brentwood has an existing agreement with CCWD for treatment at RBWTP, supply is from existing agreement with ECCID, and the infrastructure is already sufficiently sized to handle additional flow (i.e., no new construction is required). Therefore, implementation challenges are minimal for this alternative.

Purchasing an additional 3 mgd of capacity at RBWTP would allow the City to delay expansion of COBWTP or delay pursuing alternate supply options for approximately 10 years based on projected max day demands and either no groundwater production or average groundwater production. If the current maximum groundwater capacity of 5.15 mgd is utilized in conjunction with treated water from COBWTP and RBWTP, then available potable water would be sufficient to meet projected max day demands through buildout. However, water quality would not meet City standards under these conditions.

Conversely, utilizing a larger amount of treated water from RBWTP during max day conditions in the next decade would allow for less groundwater to be used which would have an overall positive impact on water quality delivered to customers.

6.12.4 Implementation Challenges, Risks, and Uncertainties Under this alternative, when water diverted from Rock Slough is high in chlorides, the weighted chlorides in the City’s system would be above the 125 mg/L target threshold during projected max day conditions by 2045. Therefore, this alternative does not fully address water quality issues for potable deliveries in the City’s service area nor with the WWTP permitted discharge MCL for chlorides.

This alternative does not provide any redundance in supply, does not increase reliability of the City’s water supply, nor does it add redundancy to the treatment or distribution system. Any major issues with RBWTP, COBWTP, or conveyance infrastructure could jeopardize potable water supply to the City.

Population growing faster than anticipated or deteriorating water quality conditions in the Delta or San Joaquin River could shorten the time before an expansion of COBWTP is required and/or additional supply options are pursued. The existing ECCID supply agreement provides sufficient supply for projected demands through 2045, based on the 2020 UWMP, but additional supply will be needed to meet the projected buildout demand of approximately 19,000 AFY.

6.13 Project Cost Summaries
Water supply yields and cost summaries for all alternatives are presented in Table 6.22. All costs are presented in 2023 dollars and assume no future escalation. This table reports the following cost parameters:
1) Capital costs in millions of dollars
2) Annual O&M costs for project components in millions of dollars per year 3) Assumed supplier charges in dollars per AF (if known)

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4) Total unit costs in dollars per AF, assuming all capital costs are financed at 2 percent1 debt cost (over 30 years, plus O&M costs and supplier charges), all divided by average water supply 5) Total annualized costs in millions of dollars per year 1 At the time of initial preparation, the Study referenced the published California Drinking Water State Revolving Fund (DWSRF) interest rate for 2022, at 1.1% (SWRCB 2022). The DWSRF program calculates its financing rate as 50% of California’s average general obligation bond rate obtained by the State Treasurer for the previous calendar year. A rate adjustment was expected for January 1, 2023, to account for 2022 bond rates. Because bond rates went up in 2022, the Study assumed a 2% interest rate.

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Table 6.22 Alternative Water Supply Cost Summary
Alternative
Additional
Supply
(AFY)
Additional
Treatment
Capacity
(mgd)
Capital Cost
($ million)
Annual
O&M Cost
($ million)
Annualized
Capital Cost
($ million)
Annualized
Capital Cost
Per AF of
Supply
Annual
O&M Cost
Per AF of
Supply
Purchase
Price of
Water
($/AF)
Total
Unit Cost
($/AF)
Annual Total
Cost
($ million/year)
Expansion of COBWTP 0 16.5 $99 $10.8 $4.4 $300 $700 $40 $1,000 $15.8 ECCID – Indian Slough 0 16.5 $292 $9.7 $13.0 $1,500 $1,100 $40 $2,700 $23.0 ECCID – Buy-in to
CCWD Old River
Intake
0 16.5 $236 $9.1 $10.5 $1,200 $1,100 $40 $2,300 $19.9
ECCID – New Intake at
Old River to New WTP
0 16.5 $358 $10.0 $16.0 $1,900 $1,200 $40 $3,100 $26.3
BBID to New WTP 8,500 16.5 $287 $9.3 $12.8 $1,500 $1,100 $110 $2,700 $23.0 BBID to COBWTP 8,500 16.5 $275 $11.7 $12.3 $1,400 $1,400 $110 $2,900 $24.8 Antioch Alternative 1
(Antioch rights)
4,600 14.25 $211 $7.3 $9.4 $2,000 $1,600 $01 $3,600 $16.7 Antioch Alternative 2
(ECCID rights, San
Joaquin River)
4,600 14.25 $211 $7.3 $9.4 $2,000 $1,600 $40 $3,600 $16.9 Antioch Alternative 3
(ECCID rights, Contra
Costa Canal)
4,600 14.25 $211 $8.8 $9.4 $2,000 $1,900 $40 $4,000 $18.4 Antioch Brackish
Desalination Facility -
Wholesale
4,500 9.0 $42 $11.0 $1.9 $400 $2,500 $1,500 $4,400 $19.6 RO – Groundwater 4,500 12.25 $214 $14.6 $9.6 $2,100 $3,300 $0 $5,400 $24.2 RO – Surface Water 0 13.5 $446 $14.7 $19.9 $4,400 $3,300 $40 $7,800 $34.8

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Alternative
Additional
Supply
(AFY)
Additional
Treatment
Capacity
(mgd)
Capital Cost
($ million)
Annual
O&M Cost
($ million)
Annualized
Capital Cost
($ million)
Annualized
Capital Cost
Per AF of
Supply
Annual
O&M Cost
Per AF of
Supply
Purchase
Price of
Water
($/AF)
Total
Unit Cost
($/AF)
Annual Total
Cost
($ million/year)
CCWD – Raw Water to
COBWTP
5,600 16.5 $107 $10.8 $4.8 $900 $1,900 $1,370 $4,200 $23.3 CCWD – Additional
Capacity at RBWTP
0 3.0 $4.5 $5.1 $0.2 $60 $1,511 $36 $1,607 $5.4
Note:
1 No charge yet available for cost of water sourced under the City of Antioch’s water rights.

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6.14 System Capacity Evaluation
When evaluating the proposed alternatives, it was important to assess available capacity in the City’s distribution system. This included confirming that the system will be able to meet pressure and velocity criteria with any potential new sources and evaluating the additional cost of any improvements required to successfully implement and operate the options. To achieve this, the supply options were evaluated using an InfoWater hydraulic model of the Brentwood water distribution system.

These modeling scenarios showed that the distribution system is not significantly affected by any of the proposed water supply options. This means that all options are hydraulically viable, and the distribution system performance does not suggest prioritizing one option over the other. No additional system improvements are needed to accommodate the additional supply regardless of the supply source or location, beyond the individual option infrastructure needs identified in this section. Some areas in the City were found to have pressures outside of the City’s design criteria, which is not related to the water supply options but could be analyzed through a separate modeling effort. This modeling effort is detailed in Appendix A, Capacity Evaluation Technical Memorandum.

The 2017 Water Master plan addressed fire flow considerations within Brentwood’s water distribution system, assessing whether the infrastructure could effectively combat a fire in any given area within the water system. The fire flow and storage requirements are dictated by land use types, varying from 2,000 gpm for two hours for lower density land uses to 4,000 gpm for four hours at higher density uses (undeveloped areas such as parks and open space have no requirements). The Master Plan analysis assessed whether the water system storage and distribution system can deliver adequate pressure and volume of water to fire hydrants in case of an emergency. The Water Master Plan concluded that flow simulations showed no deficiencies in providing adequate fire flows to all points in the water distribution system. As part of the Water Supply Option Study, simulations were run comparing the baseline water distribution operation with configurations with the additional infrastructure associated with the new supply options and found no difference in system performance, so the implementation of any of the new supply options would not have an adverse effect on Brentwood’s capability to meet fire flow requirements.

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7.0 Ranking the Water Supply Options
A key objective of the Study was to identify and evaluate water supply options that could be developed to meet potential water supply needs through 2050, as identified in Section 5. Feasible water supply options, presented in Section 6, were scored against multiple criteria and then ranked to see trade-offs and develop a long-term strategy.

7.1 Project Ranking Approach
The commercial software Criterium Decision Plus (CDP) Version 4.0, developed by Infoharvest Inc., was used to rank the feasible water supply options because of its sophistication, ease of understanding and use, and its ability to conduct sensitivity analyses. Figure 7.1 illustrates the project ranking approach through several steps, which are numbered below.
1) The raw metric score (in this example, percentage reduction of supply shortage) for a given alternative and given subcriterion is compared across all alternatives. 2) The raw metric scores for the subcriterion are standardized to a value from 0.0 to 1.0, using a linear or specified (nonlinear) value function.
3) Weights are established for all the subcriteria.
4) That subcriterion weight is applied to the standardized score from Step 2 for a given alternative. 5) The partial metric score for the given alternative is plotted. 6) The process is repeated for each subcriterion for the given alternative, resulting in the stacked bar chart of total score, where the maximum possible score is 1.0.

Figure 7.1 Project Ranking Approach Using Multicriteria Decision Analysis Method

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7.2 Evaluation Criteria
The evaluation criteria were developed in consultation with City staff and were used to compare and rank water supply alternatives. Evaluation criteria are not typically equal in importance, so weights are used to indicate relative comparisons between them. Some metrics were measured by engineering cost estimates and considered quantitative measurements, while other metrics were measured by qualitative scoring using insights from engineering judgment. Use of both quantitative and qualitative metrics for evaluating alternatives is common in planning studies that use multi-attribute rating techniques.

While the evaluation criteria used for the Study are like those used in other comparable plans and studies across the United States, the criteria weights and specific metrics used for this plan were tailored to reflect local conditions and considerations. Table 7.1 presents the evaluation criteria, proposed weightings, metrics, and metric measurement. Qualitative metrics were determined using a 1 to 5 scale, where 1 indicates the lowest relative performance and 5 indicates the highest relative performance.

The qualitative metrics for system reliability, system redundancy, water quality regulatory compliance, water quality satisfaction/perception, development ease, system integration ease, and energy intensity were determined using a 1 to 5 scale, where 1 indicates the lowest relative performance and 5 indicates the highest relative performance. According to principles of decision science and MCDA, qualitative metrics should be assigned on a relative basis, meaning at least one alternative should receive a score of 1 and at least one alternative should receive a score of 5. The narrative for establishing the metric scores for the qualitative subcriteria are presented in Table 7.2.

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Table 7.1 Evaluation Criteria for Ranking Supply Alternatives Criteria Subcriteria Metric Performance Source of
Measurement
Metric
Weighting
Reliability
(60% importance)
Supply Capacity Additional supply
provided
Higher volume
is better
Informed by
analysis
10%
Treatment Capacity Additional treatment
capacity provided
Higher volume
is better
Informed by
analysis
10%
System Reliability Risk from drought and
climate change (1 to 5)
Higher score is
better
Informed by
analysis
20%
System Redundancy Improvement to overall
system redundancy (1
to 5)
Higher score is
better
Informed by
analysis
20%
Cost
(10% importance)
Annual Cost Annual cost in millions
of dollars per year
Lower $ is
better
Engineer’s
estimate
10%
Water Quality
(15% importance)
Regulatory Compliance Maintaining acceptable
levels of chlorides in
WWTP effluent
discharge to Marsh
Creek (1 to 5)
Higher score is
better
Informed by
analysis
10%
Customer
Satisfaction/Perception
Improvement in taste
and odor and water
hardness delivered to
customers. Equity in
water quality
throughout service
area (1 to 5)
Higher score is
better
Informed by
analysis
5%
Implementation
(10% importance)
Development Ease Partnership/legal
complexity (1 to 5)
Higher score is
better
Expert judgment 5%
System Integration
Ease
Degree of difficulty
integrating supply into
the existing distribution
system and operating
new facilities (1 to 5)
Higher score is
better
Expert judgment 5%
Environmental
(5% importance)
Energy Intensity Level of project impact
on environment (1 to
5)
Higher score is
better
Informed by
analysis
5%

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Table 7.2 Narrative for Assigning Qualitative Scores
Subcriteria Metric Scoring Assumption
System Reliability Represents a project’s risk from drought and climate change.

Score of 1 indicates significant risk from drought and/or climate change variability.

Score of 3 indicates moderate risk from drought and/or climate change variability.

Score of 5 indicates little risk from drought and/or climate change variability.

System
Redundancy
Represents the improvement to overall system redundancy from a project’s impact on raw water conveyance, potable treatment, and treated water conveyance to the service area.

Score of 1 indicates little to no improvement to system redundancy.

Score of 3 indicates moderate improvement to system redundancy.

Score of 5 indicates significant improvement to system redundancy.

Regulatory
Compliance
Represents the project’s contribution to reductions in chloride levels in WWTP effluent and ability to meet NPDES permit requirements.

Score of 1 indicates little to no improvement in chloride levels in WWTP effluent.

Score of 3 indicates moderate improvement in chloride levels in WWTP effluent.

Score of 5 indicates significant improvement in chloride levels in WWTP effluent.

Customer
Satisfaction/
Perception
Represents the improvement in customer satisfaction from project’s impact on aesthetic water quality (taste and odor) delivered to customers, reduction in water hardness over groundwater, and equity in water quality throughout service area.

Score of 1 indicates little to no improvement in taste and odor, water hardness, and equity in water quality throughout the service area.

Score of 3 indicates moderate improvement throughout the service area.

Score of 5 indicates significant improvement throughout the service area.

Development Ease Represents the project’s level of partnership complexity, accounting for the number and type of partners, and potential legal difficulties.

Score of 1 indicates significant complexity and potential legal barriers to implementation.

Score of 3 indicates moderate complexity and potential legal barriers to implementation.

Score of 5 indicates little to no complexity and potential legal barriers to implementation.

System Integration
Ease
Represents the project’s degree of complexity to operate new facilities and/or integrate new water supplies with existing sources.

Score of 1 indicates significant complexity and difficulty integrating with current system.

Score of 3 indicates moderate complexity and difficulty integrating with current system.

Score of 5 indicates little to no complexity and difficulty integrating with current system.

Energy Intensity Represents the level of energy required for project operations as a proxy for greenhouse gas emissions, prior to any energy mitigation
Score of 1 indicates highest energy intensity.

Score of 3 indicates medium energy intensity.

Score of 5 indicates lowest energy intensity.

7.3 Supply Option Metric Scores
Using the qualitative score narratives in Table 7.2, proposed qualitative scores were assigned to each supply option. Table 7.3 through Table 7.9 present the qualitative scores for each supply option and the justification for the scoring. All the metric scores for the supply options are summarized in Table 7.10 for ranking.

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Table 7.3 System Reliability Scores
Supply Alternative Score Score Justification
Expansion of COBWTP 3 Water quality may suffer during prolonged drought or consecutive dry years. ECCID has pre-1914 water rights.

ECCID Indian Slough 3 Water quality may suffer during prolonged drought or consecutive dry years, assumed it would be worse water quality than Old River.

ECCID has pre-1914 water rights.

ECCID/CCWD Old River 1 Use of CCWD infrastructure may lead to restrictions/curtailments during drought because CCWD does not have pre-1914 water rights.

ECCID Old River 3 Water quality may suffer during prolonged drought or consecutive dry years. ECCID has pre-1914 water rights.

BBID to New WTP
(Subalternative 1)
3 Water quality may suffer during prolonged drought or consecutive dry years. BBID has pre-1914 water rights.

BBID to COBWTP
(Subalternative 2)
3 Water quality may suffer during prolonged drought or consecutive dry years. BBID has pre-1914 water rights.

Antioch Alternative 1 (Antioch rights) 5 RO treatment effective even if chlorides increase significantly in the San Joaquin River. The City of Antioch has pre-1914 water rights.

Antioch Alternative 2 (ECCID rights, San
Joaquin River)
5 RO treatment effective even if chlorides increase significantly in the San Joaquin River. ECCID has pre-1914 water rights.

Antioch Alternative 3 (ECCID rights,
Contra Costa Canal)
5 RO treatment effective even if chlorides increase significantly in the Contra Costa Canal and Rock Slough diversion. ECCID has pre1914 water rights.

Antioch Wholesale 1 Drought conditions or consecutive dry years would force the City of Antioch to purchase more water from CCWD instead of
pumping from San Joaquin River. This could make it impractical to sell wholesale water to the City of Brentwood.

Reverse Osmosis – Groundwater 4 RO treatment effective for high levels of chlorides but only so much groundwater is available for treatment; should chlorides increase in Contra Costa Canal significantly, this option would not be sufficient to improve water quality to acceptable levels. ECCID has pre-1914 water rights.

Reverse Osmosis – Surface Water 5 RO treatment would be effective even if chlorides increase significantly in the Contra Costa Canal and Rock Slough diversion.

ECCID has pre-1914 water rights.

CCWD Raw Water to COBWTP 1 Use of CCWD infrastructure may lead to restrictions/curtailments during drought because CCWD does not have pre-1914 water rights.

CCWD Purchase Additional Capacity at
RBWTP
3 Water quality may suffer during prolonged drought or consecutive dry years. ECCID has pre-1914 water rights.

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Table 7.4 System Redundancy Scores
Supply Alternative Score Score Justification
Expansion of COBWTP 1 No changes over existing conditions.

ECCID Indian Slough 5 Sources raw water from new location, uses different/new infrastructure over existing conditions, and enters the distribution system in a new location.

ECCID/CCWD Old River 4 Sources raw water from different location, uses different infrastructure for conveyance and treatment, and enters the distribution system in a new location. However, this point of diversion is already part of the existing emergency supply plan.

ECCID Old River 5 Sources raw water from new location, uses new infrastructure for conveyance and treatment, and enters the distribution system in a new location.

BBID to New WTP
(Subalternative 1)
5 New supply source using all new infrastructure and entering the distribution system in a new location.

BBID to COBWTP
(Subalternative 2)
3 New supply source using new raw water pipeline but relies on COBWTP for majority of treatment and a single treated water pipeline for conveyance to the potable distribution system.

Antioch Alternative 1 (Antioch rights) 5 New supply source with different point of diversion and raw water conveyance, uses different WTP, and enters distribution system in different location.

Antioch Alternative 2 (ECCID rights, San
Joaquin River)
5 New supply source with different point of diversion and raw water conveyance, uses different WTP, and enters distribution system in different location.

Antioch Alternative 3 (ECCID rights,
Contra Costa Canal)
4 New supply source with different point of diversion, uses different WTP, and enters distribution system in different location. Uses Contra Costa Canal for raw water conveyance.

Antioch Wholesale 5 New supply source with different point of diversion and raw water conveyance, uses different WTP, and enters distribution system in different location.

Reverse Osmosis – Groundwater 2 Existing supply source to higher potential. Uses a new treatment facility and enters distribution system in different location.

Reverse Osmosis – Surface Water 1 No changes over existing conditions.

CCWD Raw Water to COBWTP 3 Relies on COBWTP for majority of treatment and potable water conveyed through a single pipe to the City of Brentwood’s service area, but raw water can be conveyed from Rock Slough or Old River
CCWD Purchase Additional Capacity at
RBWTP
1 No changes over existing conditions.

7.0 │ RANKING THE WATER SUPPLY OPTIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 7-7
Table 7.5 Maintaining Water Quality
Supply Alternative Score Score Justification
Expansion of COBWTP 1 No change over existing conditions.

ECCID Indian Slough 1 No change over existing conditions.

ECCID/CCWD Old River 2 Only a minor improvement, if any, over existing supplies from Rock Slough.

ECCID Old River 2 Only a minor improvement, if any, over existing supplies from Rock Slough.

BBID to New WTP
(Subalternative 1)
2 Only a minor improvement, if any, over existing supplies from Rock Slough.

BBID to COBWTP
(Subalternative 2)
2 Only a minor improvement, if any, over existing supplies from Rock Slough.

Antioch Alternative 1 (Antioch rights) 5 Will meet target of 100 mg/L of chloride under average day demands. Maximum day demands will exceed target but below threshold of 125 mg/L. Slightly higher concentrations than the Brentwood RO options.

Antioch Alternative 2 (ECCID rights, San
Joaquin River)
5 Will meet target of 100 mg/L of chloride under average day demands. Maximum day demands will exceed target but below threshold of 125 mg/L. Slightly higher concentrations than the Brentwood RO options.

Antioch Alternative 3 (ECCID rights,
Contra Costa Canal)
5 Will meet target of 100 mg/L of chloride under average day demands. Maximum day demands will exceed target but below threshold of 125 mg/L. Slightly higher concentrations than the Brentwood RO options.

Antioch Wholesale 5 Will meet target of 100 mg/L of chloride under average day demands. Maximum day demands will exceed target but below threshold of 125 mg/L. Slightly higher concentrations than the Brentwood RO options.

Reverse Osmosis – Groundwater 5 Would meet target of 100 mg/L on average demand days even with high chloride at COBWTP. Maximum day demands would either be below target or at least below maximum threshold of 125 mg/L. Reduction in water hardness could also result in less use of water softeners throughout service area.

Reverse Osmosis – Surface Water 5 Would meet target of 100 mg/L on average demand days even with high chloride at COBWTP. Maximum day demands would either be below target or at least below maximum threshold of 125 mg/L. Reduction in water hardness could also result in less use of water softeners throughout service area.

CCWD Raw Water to COBWTP 3 Assuming CCWD blends water to maintain consistent water quality, this would be a slight improvement over existing conditions from Rock Slough.

CCWD Purchase Additional Capacity at
RBWTP
1 No change over existing conditions.

7.0 │ RANKING THE WATER SUPPLY OPTIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 7-8
Table 7.6 Customer Satisfaction/Perception Scores
Supply Alternative Score Score Justification
Expansion of COBWTP 1 No change over existing conditions. Improvement in hardness over groundwater and may improve water quality throughout service area by replacing groundwater but no improvement to taste and odor.

Overall hardness would still be in the hard range.

ECCID Indian Slough 1 No change over existing conditions. Improvement over groundwater and may improve water quality throughout service area but still likely to still be different water quality in different locations. No improvement to taste and odor.

ECCID/CCWD Old River 3 Reduced water hardness over groundwater but still likely to be in the hard range. Similar taste and odor issues as existing supply but potentially less significant because of no canal conveyance. Water quality would still vary throughout service area but improvement over existing conditions.

ECCID Old River 3 Reduced water hardness over groundwater but still likely to be in the hard range. Similar taste and odor issues as existing supply but potentially less significant because of no canal conveyance. Water quality would still vary throughout service area but would be an improvement over existing conditions.

BBID to New WTP
(Subalternative 1)
3 Reduced water hardness over groundwater but still likely to be in the “hard” range. Similar taste and odor issues as existing supply. Likely more consistent water quality throughout service area.

BBID to COBWTP
(Subalternative 2)
3 Reduced water hardness over groundwater but still likely to be in the hard range. Similar taste and odor issues as existing supply. Likely more consistent water quality throughout service area.

Antioch Alternative 1 (Antioch
rights)
4 Reduced water hardness over groundwater, less taste and odor issues, but still some variation in water quality throughout service area.

Antioch Alternative 2 (ECCID rights,
San Joaquin River)
4 Reduced water hardness over groundwater, less taste and odor issues, but still some variation in water quality throughout service area.

Antioch Alternative 3 (ECCID rights,
Contra Costa Canal)
4 Reduced water hardness over groundwater, less taste and odor issues, but still some variation in water quality throughout service area.

Antioch Wholesale 4 Reduced water hardness over groundwater, less taste and odor issues, but still some variation in water quality throughout service area.

Reverse Osmosis – Groundwater 4 Water hardness would be significantly reduced, and water quality would improve throughout service area but still some variation in different locations. Does not address taste and odor from surface supply.

Reverse Osmosis – Surface Water 5 Water hardness would be significantly reduced in surface water supply, and this replaces use of groundwater. Water quality would improve throughout service area, and taste and odor should improve.

CCWD Raw Water to COBWTP 3 Reduced water hardness over groundwater but still likely to be in the hard range. No improvement to taste and odor. Water quality would be more consistent across the service area.

CCWD Purchase Additional Capacity
at RBWTP
3 Utilizing a larger amount of treated water from RBWTP during max day conditions would allow for less groundwater to be used which would have an overall positive impact on customer water quality.

7.0 │ RANKING THE WATER SUPPLY OPTIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 7-9
Table 7.7 Development Ease Scores
Supply Alternative Score Score Justification
Expansion of COBWTP 5 No changes to existing agreements, just an expansion of an existing facility. Coordination with CCWD but should be simple. No legal issues anticipated.

ECCID Indian Slough 5 Only involves ECCID and uses point of diversion already specified in existing agreement (i.e., no legal barriers).

ECCID/CCWD Old River 1 Involves multiple partners, including CCWD, USBR, and potentially DWR. Would require a complex agreement for use of CCWD/LVR infrastructure that requires the City of Brentwood to secure rights to use CCWD’s intake.

ECCID Old River 2 Partnership with ECCID but likely requires DWR approval to modify point of diversion. The existing agreement specifies they can use the CCWD intake and this would change by using new
infrastructure.

BBID to New WTP
(Subalternative 1)
4 Partnership with BBID. Requires resolution of place-of-use issue but not a significant barrier to implementation.

BBID to COBWTP
(Subalternative 2)
4 Partnership with BBID. Requires resolution of place-of-use issue but not a significant barrier to implementation.

Antioch Alternative 1 (Antioch rights) 1 Involves multiple partners, including DWR, and has significant legal barriers to implementation, including a place-of-use issue that may prevent the City of Antioch from providing water outside their service area. Delta Diablo for brine disposal.

Antioch Alternative 2 (ECCID rights, San
Joaquin River)
1 Involves multiple partners, including DWR. Requires modification to ECCID point of diversion, and significant legal barriers to implementation, including a place-of-use issue that may prevent the City of Antioch from providing water outside their service area.

Antioch Alternative 3 (ECCID rights,
Contra Costa Canal)
1 Involves multiple partners, including CCWD, but requires no modification to ECCID agreement. Should avoid the place-of-use issue but requires significant coordination with the City of Antioch.

Antioch Wholesale 2 Partnership with the City of Antioch but may require DWR approval and/or legal barrier related to place-of-use issue.

Significant coordination required for construction of conveyance pipeline.

Reverse Osmosis – Groundwater 1 Partnerships would be with Delta Diablo for brine disposal and the City of Antioch for brine disposal pipeline easements, but Delta Diablo could be problematic and may also require DWR and/or RWQCB involvement.

Reverse Osmosis – Surface Water 1 Partnerships would be with Delta Diablo for brine disposal and the City of Antioch for brine disposal pipeline easements, but Delta Diablo could be problematic and may also require DWR and/or RWQCB involvement.

CCWD Raw Water to COBWTP 3 Involves coordination with CCWD and USBR and a revision to the existing agreement.

CCWD Purchase Additional Capacity at
RBWTP
5 Involves coordination with existing partner CCWD.

7.0 │ RANKING THE WATER SUPPLY OPTIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 7-10
Table 7.8 System Integration Ease Scores
Supply Alternative Score Score Justification
Expansion of COBWTP 5 No change from existing conditions, just increase in treatment capacity.

ECCID Indian Slough 3 Similar source water to existing supply. Connecting to distribution system should be relatively simple.

ECCID/CCWD Old River 1 Difficult to integrate CCWD operation for a segment of the conveyance pipeline with the City of Brentwood’s operation of a new WTP.

ECCID Old River 3 New treatment plant with significant amount of conveyance.

Treated water conveyance and connecting to potable distribution system should be relatively simple.

BBID to New WTP
(Subalternative 1)
3 New raw water source but integrating the new treatment and potable conveyance should be relatively simple.

BBID to COBWTP
(Subalternative 2)
3 New raw water source, but treatment and potable conveyance to Brentwood remain the same.

Antioch Alternative 1 (Antioch rights) 3 New source of water but no further treatment required once it reaches Brentwood. Should be relatively simple to connect to potable distribution system.

Antioch Alternative 2 (ECCID rights, San
Joaquin River)
3 New source of water but no further treatment required once it reaches Brentwood. Should be relatively simple to connect to potable distribution system.

Antioch Alternative 3 (ECCID rights,
Contra Costa Canal)
3 New source of water but no further treatment required once it reaches Brentwood. Should be relatively simple to connect to potable distribution system.

Antioch Wholesale 3 New source of water but no further treatment required once it reaches Brentwood. Should be relatively simple to connect to potable distribution system.

Reverse Osmosis – Groundwater 2 New stand-alone facility for advanced treatment and then blending in suitably sized pipe in the distribution system. Would need to employ new staff or come to arrangement with CCWD over
operation of facility.

Reverse Osmosis – Surface Water 3 Add-on facility to COBWTP. Requires determining optimal blending ratio.

CCWD Raw Water to COBWTP 5 No change from existing conditions, just increase in treatment capacity.

CCWD Purchase Additional Capacity at
RBWTP
5 No change from existing conditions, just increase in treatment capacity.

7.0 │ RANKING THE WATER SUPPLY OPTIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 7-11
Table 7.9 Energy Intensity Scores
Supply Alternative Score Score Justification
Expansion of COBWTP 4 Lower energy intensity because of shorter conveyance.

ECCID Indian Slough 4 Lower energy intensity because of shorter conveyance ECCID/CCWD Old River 3 Moderate energy intensity.

ECCID Old River 3 Moderate energy intensity.

BBID to New WTP
(Subalternative 1)
3 Moderate energy intensity.

BBID to COBWTP
(Subalternative 2)
2 Higher energy intensity because of significant amount of conveyance.

Antioch Alternative 1 (Antioch rights) 2 Higher energy intensity than conventional treatment.

Antioch Alternative 2 (ECCID rights, San
Joaquin River)
2 Higher energy intensity than conventional treatment.

Antioch Alternative 3 (ECCID rights,
Contra Costa Canal)
2 Higher energy intensity than conventional treatment.

Antioch Wholesale 5 Lowest energy intensity.

Reverse Osmosis – Groundwater 1 Highest energy intensity because of the energy needed to extract groundwater in addition to water treatment.

Reverse Osmosis – Surface Water 2 Higher energy intensity than conventional treatment.

CCWD Raw Water to COBWTP 4 Lower energy intensity because of shorter conveyance.

CCWD Purchase Additional Capacity at
RBWTP
5 Lowest energy intensity because no new conveyance required, use of conventional treatment, and increased treatment from larger plant provides possible energy efficiencies.

All the performance metric scores assigned to each alternative are summarized in Table 7.10.

7.0 │ RANKING THE WATER SUPPLY OPTIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 7-12
Table 7.10 Criteria Scores Assigned to Alternatives
Supply Alternative
Reliability Cost Water Quality Implementation Environmental Additional
Supply
(AFY)
Additional
Treatment
Capacity
(MGD)
Supply
Reliability
Supply
Redundancy
Annual Total
Cost
(millions of $)
Regulatory
Compliance
Customer
Satisfaction/
Perception
Development
Ease
System
Integration
Ease
Energy
Intensity
Expansion of COBWTP 0 16.5 3 1 $15.8 1 1 5 5 4
ECCID Indian Slough to New WTP 0 16.5 3 5 $23.0 1 1 5 3 4 ECCID/CCWD Old River to New
WTP
0 16.5 1 4 $19.9 2 3 1 1 3
ECCID Old River to New WTP 0 16.5 3 5 $26.3 2 3 2 3 3
BBID to New WTP
(Subalternative 1)
8,524 16.5 3 5 $23.0 2 3 4 3 3
BBID to COBWTP
(Subalternative 2)
8,524 16.5 3 3 $24.8 2 3 4 3 2
Antioch Alternative 1 (Antioch
rights, expanded RO & COBWTP)
4,630 14.25 5 5 $16.7 5 4 1 3 2
Antioch Alternative 2 (ECCID
rights, San Joaquin River,
expanded RO & COBWTP)
4,630 14.25 5 5 $16.9 5 4 1 3 2
Antioch Alternative 3 (ECCID
rights, Contra Costa Canal,
expanded RO & COBWTP)
4,630 14.25 5 4 $18.4 5 4 1 3 2
Antioch Wholesale 4,480 9.0 1 5 $19.6 5 4 2 3 5
Reverse Osmosis - Groundwater 4,480 12.25 4 2 $24.2 5 4 1 2 1 Reverse Osmosis – Surface
Water
0 13.5 5 1 $34.8 5 5 1 3 2
CCWD Raw Water to COBWTP 5,600 16.5 1 3 $23.3 3 3 3 5 4 CCWD Purchase Additional
Capacity at RBWTP
0 3.0 3 1 $5.4 1 3 5 5 5
Note: Red color indicates lowest relative score, and Green color indicates highest relative score.

7.0 │ RANKING THE WATER SUPPLY OPTIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 7-13

7.4 Project Ranking
The proposed criteria metric scores for the water supply alternatives shown in Table 7.10 and the criteria weights shown in Table 7.1 were input into the decision software CDP to rank the supply options. These scores and rankings are shown in Figure 7.2.

Figure 7.2 Ranking of Alternatives by Criteria
The length of the stacked bar for each supply option represents its aggregated score. The length of each color segment of the bar represents the score for the five main criteria. The longer the bar segment, the better it performs against the given criterion. If a supply option has the worst score for any specific subcriterion, there is no color contribution for that subcriterion. This allows for direct comparison of how one option performs compared to others for each of the criteria. For example, one supply option might have a very high score for supply reliability but have a low (poor) score for annual cost.

The ranking results are interpreted as follows:
▬ The project alternatives sourcing water from Antioch were ranked the highest with strong scores for supply reliability, cost, and water quality improvement, even with lower scores for implementation ease and environmental impact.
▬ The BBID to New WTP alternative ranked next highest because of a mix of high scores for supply reliability, ease of implementation, and environmental impact. ▬ The Antioch Wholesale and ECCID Indian Slough alternatives rounds out the top half of the project rankings with relatively high scores for supply reliability, cost, and ease of implementation, although the reliability scores were significantly lower than the higher ranked projects. The ECCID Indian Slough alternative also has issues with water quality. ▬ The ECCID Old River and BBID to COBWTP alternatives ranked in the middle of the group of projects because of issues with cost, water quality, and supply reliability.

7.0 │ RANKING THE WATER SUPPLY OPTIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 7-14
▬ Adding an RO plant to treat current groundwater or surface water supplies were the nexthighest-ranked projects, with mid-range scores for supply reliability and high scores for water quality improvement. However, RO-Groundwater received no environmental impact score because of its high energy use and RO-Surface Water received a no cost score because of its high cost.
▬ The project to bring CCWD raw water to COBWTP ranked in the bottom third because of low scores for supply reliability and cost.
▬ Purchasing additional treatment capacity at RBWTP ranks as the third lowest because of a low reliability score because it does not add any new water supply and does less to improve water quality than other options, but the rest of the criteria on this project has mid to high scores. ▬ Projects with the lowest rankings include COBWTP expansion and the ECCID Old River option collaborating with CCWD. This was due to a mix of low scores for supply reliability (COBWTP expansion and ECCID/CCWD Old River) and water quality (COBWTP expansion).

The criteria weightings and scores were reviewed and revised with City staff. Additional sensitivity analyses can be performed to determine how the supply options ranking would shift if the evaluation criteria weightings were further changed, if requested.

WATER SUPPLY OPTIONS STUDY │ PAGE 8-1

8.0 Recommendations
To implement a water resources strategy for the City, near- and mid-term recommendations are presented in Table 8.1. For each recommended action, roles for Brentwood and other agencies/entities are indicated, where applicable.

Near-term recommendations focus on an expansion of treatment capacity to address the need by 2030 for additional capacity to meet max day demands. All the projects assessed provide additional treatment. However, several projects focus on increasing treatment capacity without providing additional supply, including the expansion of COBWTP, the various projects to bring ECCID water to a new WTP in the south end of Brentwood, the RO-Surface Water project, and the purchase of additional RBWTP capacity from CCWD. Among these options, by far the cheapest option for providing this new treatment capacity is the purchase of additional capacity at RBWTP at an annual total cost of $5.4 million (the lowest by more than $10 million, as shown in Table 6.22). This option also gets high marks for implementation, development ease, and system integration because it utilizes an existing WTP with an existing partner. Implementing this increase in RBWTP capacity can delay the need for additional water supply and max day capacity for up to 10 years, to 2040 when using no groundwater supply and to 2045 using average groundwater production. This approach would allow for a more thorough feasibility evaluation of the additional supply options before moving one forward for design and implementation to meet build-out supply and max day treatment needs.

Included in the near-term recommendations is the continued tracking and management of WWTP effluent chloride levels by balancing supply sourced from groundwater and surface water. It is critical to monitor the long-term sustainability of the City’s groundwater resources and to incorporate this information into future supply need analyses and potential supply evaluations. The City should also continue tracking its per capita water demand to assess potential changes to future supply need.

Mid-term recommendations focus on taking steps to provide additional supply to address the build-out supply gap of 2,157. There are eight projects that provide additional supply ranging from 4,630 to 8,524 AFY, including four projects that require partnership with Antioch, two that bring BBID water to a new WTP or the current COBWTP, one that adds RO treatment to groundwater supplies, and one that brings raw water from CCWD to COBWTP.

The four Antioch options all scored very high in the analysis so future conversations with Antioch are recommended to further explore the feasibility of those options. The remaining two options with additional BBID supply that ranked in the top half of projects offer a comparison of the system redundancy benefit of a new WTP in southern Brentwood to using the existing COBWTP without providing additional redundancy. These trade-offs can be further evaluated as actions are implemented towards identifying the most feasible project to provide additional supply and max day treatment capacity to the City.

8.0 │ RECOMMENDATIONS
WATER SUPPLY OPTIONS STUDY │ PAGE 8-2
Table 8.1 Recommended Actions
Action Brentwood Other Agencies
Near-Term
Increase max day treatment
capacity to address needs
• Negotiate with CCWD on pricing and
terms for 3 mgd of additional
treatment capacity at RBWTP.
• CCWD works with the City to amend
RBWTP agreement.

Track WWTP effluent chloride
levels
• Continue managing groundwater use to
balance supply needs and NPDES
requirements.

Track per capita water demand • Continue tracking annual per capita water demand and potential effect on
supply need
Mid-Term
Explore options for desalinated
water from the City of Antioch
• Hold discussions with Antioch on their
interest in expanding plant and
potential excess capacity available.
• Develop MOU with Antioch to explore
expansion partnership or wholesale
purchase opportunities.
• Conduct conveyance evaluation to
identify easements and/or areas to
avoid.
• Engage legal team to evaluate which
option (subalternative or wholesale
option) is most beneficial to Brentwood
from a water rights/place-of use
perspective.
• Conduct detailed feasibility study of
option(s).

If Antioch is interested:
• Antioch and Delta Diablo negotiate
additional brine disposal
• Antioch may need to evaluate
place-of-use, depending on which
subalternative is chosen.
• ECCID may need to modify point of
diversion, depending on which
subalternative is chosen.
• ECCID may need to negotiate with
CCWD on raw water flows through
Contra Costa Canal.

If Antioch is not interested or
supply/capacity is not available,
move to next actions.

Explore options with BBID for
supply and/or partnership in
treatment capacity
• Develop MOU with BBID to explore
options to purchase supply and partner
on new WTP or treat at COBWTP.
• Engage real estate team to identify
parcels and potential site acquisition
costs for a new WTP.
• Conduct conveyance evaluation to
identify easements and/or areas to
avoid.
• Reach out again to Town of Discovery
Bay on interest in partnership
opportunities to provide supply
reliability to the area and offset project
costs.
• Conduct detailed feasibility study of
option(s).
• BBID conducts BBID canal water loss
evaluation.
• BBID engages legal team to modify
place-of-use with DWR.

WATER SUPPLY OPTIONS STUDY │ PAGE 9-1

9.0 References
Billica, J.A., J. Oropeza, and G.K. Elmund. 2010. “Monitoring to Determine Geosmin Sources and Concentrations in a Northern Colorado Reservoir.” City of Fort Collins Utilities. Proceedings of the National Water Quality Monitoring Council 7th National Monitoring Conference. April 25–29, 2010.

Denver, CO.

Byron-Bethany Irrigation District (BBID). 2017. Agricultural Water Management Plan. Prepared by CH2M Hill Engineers, Inc. on behalf of the Byron-Bethany Irrigation District. Accessed June 6, 2022, https://bbid.org/tag/agricultural-water-management-plan/.

Byron-Bethany Irrigation District (BBID). 2016. Agricultural Water Delivery User Charges Cost of Service Study. Prepared by CH2M Hill Engineers, Inc. on behalf of the Byron-Bethany Irrigation District. Accessed October 21, 2022, https://bbid.org/governance/your-water-rates/.

California Data Exchange Center. n.d. “Historical Data Selector.” California Department of Water Resources. Accessed September 14, 2022, Available at:
https://cdec.water.ca.gov/dynamicapp/selectQuery.

CDM Smith. 2005. Final Preliminary Design Report: Surface Water Treatment Facility Phase II Project.

Prepared for the City of Brentwood. June 16, 2005.

City of Antioch. 2021. 2020 Urban Water Management Plan. Prepared by Brown and Caldwell on behalf of the City of Antioch. Published May 2021. Available at:
https://www.antiochca.gov/fc/environment/UWMP.pdf.

City of Antioch. 2018. Brackish Water Desalination Facility Draft Environmental Impact Report. Prepared by ESA on behalf of the City of Antioch. Published June 2018. Available at:
https://www.antiochca.gov/fc/community-development/planning/Brackish-Water-DEIR.pdf.

City of Antioch. 2014. Water System Master Plan Update. Prepared by Brown and Caldwell on behalf of the City of Antioch. Published August 2014. Available at: https://www.antiochca.gov/fc/capitalimprovements/water/Water-System-Master-Plan.pdf.

City of Brentwood. 2021. 2020 Urban Water Management Plan. Prepared by Brown and Caldwell on behalf of the City of Brentwood. Published June 2021, revised December 2021. Available at:
https://www.brentwoodca.gov/home/showpublisheddocument/3314/637805280436500000.

City of Brentwood. 2020. Brentwood/CCWD Memorandum of Understanding Regarding Potential Service from CCWD’s Los Vaqueros Facilities. April 30, 2020.

City of Brentwood. 2018. City of Brentwood Water and Wastewater Cost of Service Study. Prepared by Raftelis on behalf of the City of Brentwood. June 26, 2018.

City of Brentwood. 2017. City of Brentwood Water Master Plan. Prepared by Ennis Consulting on behalf of the City of Brentwood. June 1, 2017.

9.0 │ REFERENCES
WATER SUPPLY OPTIONS STUDY │ PAGE 9-2
City of Brentwood. 2013. Existing Conditions Report, City of Brentwood General Plan Update. April 9, 2013.

City of Brentwood. 2009. Second Amendatory Agreement Between the Contra Costa Water District and the City of Brentwood. July 31, 2009.

City of Brentwood. 1999. Water Sales Agreement Between the East Contra Costa Irrigation District and the City of Brentwood. December 14, 1999.

Contra Costa Water District (CCWD). 2021. 2020 Urban Water Management Plan. Published June 2021.

Available at: https://www.ccwater.com/1053/Urban-Water-Management-Plan.

Contra Costa Water District (CCWD). n.d.-a. Annual Water Quality Reports. Available at:
https://www.ccwater.com/Archive.aspx?AMID=36.

Contra Costa Water District (CCWD). n.d.-b. Code of Regulations: Title 5 Water Supply and Rates.

Available at: https://www.ccwater.com/DocumentCenter/View/281/Title-5-Water-Supply-and-RatesPDF?bidId=.

Delta Diablo. 2020. Reverse Osmosis Discharge Facilities Operation and Maintenance Agreement.

October 27, 2020. Antioch, CA. Available at: http://www.antiochbrackishdesal.com/fc/Delta-DiabloReverse-Osmosis-Agreement.pdf.

Duranceau, S.J. 2018. “Optimum Permeate Blending.” Water & Wastes Digest. Summer 2010. Page 16-

Jones, G.M., and R.L. Sanks. 2008. Pumping Station Design (Revised 3rd Edition). Published by Elsevier.

Retrieved from https://app.knovel.com/hotlink/toc/id:kpPSDRE005/pumping-station-design/pumpingstation-design.

Peacock, B. 1996. Energy and Cost Required to Lift or Pressurize Water. University of California Cooperative Extension. Available at: https://cetulare.ucanr.edu/files/82040.pdf.

State Water Resources Control Board (SWRCB). 2022. “Interest Rate History.” California Water Boards.

Available at:
https://www.waterboards.ca.gov/drinking_water/services/funding/documents/srf/dwsrf_interest_rate _history.pdf.

U.S. Census Bureau. 2021. “QuickFacts: Brentwood city, California.”. Available at:
https://www.census.gov/quickfacts/fact/table/brentwoodcitycalifornia/POP010220.

Appendix A Capacity Evaluation Technical
Memorandum

Memorandum
To: City of Brentwood
From: Shilpa Shivakumar, PE, PMP
Erin Walsh, PE
Andria Loutsch, AICP, PMP
Date: March 2, 2023
Subject: Brentwood Water Supply Options Study: Task 3 – Capacity Evaluation The goal of the City of Brentwood Water Supply Options Study is to identify and evaluate potential water supply alternatives to ensure the City’s drinking water supply will be of sufficient quality and quantity to satisfy ultimate buildout conditions. When evaluating the proposed alternatives, it is important to assess available capacity in the City’s existing distribution system. This includes confirming that the system will be able to meet pressure and velocity criteria with any potential new sources and considering the additional cost of any improvements required to successfully implement and operate the selected option. To achieve this, the supply options were evaluated using an InfoWater hydraulic model of the Brentwood water distribution system.

Model Background, Updates, and Verification
The model used to evaluate supply projects was developed using H2OMAP Water as part of the 2017 Master Plan effort by Ennis Consulting. This model included a scenario for the maximum day conditions through buildout, which was used by CDM Smith for the Water Supply Options Study.

This scenario included total demands of 30.4 million gallons per day (MGD), which is the same used for the Water Supply Options Study, so no changes to demands were made. It was assumed that the model had been calibrated in 2017 and reflected the system’s overall operations accurately for the Master Plan.

Some changes were made to this model for use in the Water Supply Options Study:
 The model was converted to InfoWater, as H2OMAP Water is no longer supported by the software vendor.
 Recommended system improvement from the City’s 2022 Water Distribution System Improvement Evaluation Memorandum were incorporated. This included upgrades to Pump Station (PS) 2.2, the addition of PS 2.4 and Reservoir 1.4, and the construction of John Muir Parkway. Five wells that are no longer in use were also removed from the model (Wells 9, 10, 11, 12, and 13).

 Some pipes that had been installed after 2017 were added to the model based on the City’s GIS provided to CDM Smith in 2022. These were assumed to have a pipe roughness C value of 140.

Spot checks on the system demands and other model components were conducted to confirm that the model conversion from H2OMAP Water to InfoWater was successful. Pressure and velocity mapping showed that the model results had not changed significantly with the updates to the model. Based on this high-level validation, the model was determined to be a suitable tool for evaluating this study’s water supply options.

Figure 1 presents the resulting pressures from the original model without additional water supply sources. Notably, there are some areas with pressure areas that are outside of the City’s design criteria. These areas are primarily in Zones 2 and 3 and mostly result in pressures above 100 pounds per square inch (psi), although some nodes also showed average pressure below 40 psi.

The City may consider more detailed modeling and analysis in the future to verify whether the system currently experiences pressure issues in these areas or will experience them through development, and how to rectify them if necessary.

Figure 1. 2017 Master Plan Model Pressures

Water Supply Options Modeling
The InfoWater model was used to evaluate the proposed water supply options to determine if any would have potential positive or negative effects on the current distribution system. This was evaluated by assessing the water pressures and velocities throughout the system before and after the addition of each new source water and transmission line. The City’s Design Criteria, as summarized in the 2017 Master Plan, states that pressures should be 40-100 psi and max day velocity should be below 10 feet per second (fps). All options were modeled at the same max day buildout demand of 30.4 MGD.

Many of the water supply options proposed are only different in terms of raw water sources or water rights but enter the distribution system at the same point with the same flowrate and head.

Therefore, these options were modeled under the same scenario. Table 1 summarizes which water supply options were modeled under which scenario. Alternatives that rely on existing infrastructure and connections to the system did not require modeling as the system conveyance capacity is sufficient to handle projected max day demands. These options are show as “N/A” in Table 1. All options are discussed in more detail in the Task 4 – Source Water Supply Alternatives and Task 5 – Project Costs Technical Memorandum (TM).

Table 1 - Supply Options by Model Scenario
Supply Alternative Model Scenario
Antioch Alternative 1 (Antioch rights)
1A – Antioch Wells
1B – Antioch No Wells
Antioch Alternative 2 (ECCID rights, San Joaquin River) Antioch Alternative 3 (ECCID rights, Contra Costa Canal) Antioch Wholesale
BBID to New WTP
(Sub-Alternative 1) 2A – Balfour Road WTP
BBID to COBWTP
(Sub-Alternative 2) N/A
ECCID Indian Slough 2A – Balfour Road WTP
ECCID Old River
ECCID/CCWD Old River 2B – Concord Avenue WTP
CCWD Raw Water to COBWTP N/A
Expansion of COBWTP N/A
Reverse Osmosis – GW 3 – ROGW
Reverse Osmosis – surface water N/A
Notes: BBID = Byron-Bethany Irrigation District, CCWD = Contra Costa Water District, COB = City of Brentwood Water Treatment Plant, ECCID = East Contra Costa Irrigation District, GW = groundwater, N/A = not applicable, ROGW = Reverse Osmosis Groundwater, WTP = Water Treatment Plant
The following modeling assumptions and methodology were used for all scenarios:
 All sources flow into Zone 1.

 Pipe roughness value “C” = 140.
 The head for new sources was set based on the Zone 1 hydraulic grade line (HGL) of 228 feet plus the headloss through the new piping into the system, as the head on the new sources was either not known or could be set to a preferred design level when constructed. Pumping or pressure reducing valves can be used to achieve the preferred HGL if the supply source HGL varies from what was assumed for this analysis.
 Flow control valves were used to set supply volumes from different sources in the model.  All model scenarios showed fluctuation in flow coming from the City of Brentwood Water Treatment Plant (COBWTP). Because COBWTP pumps from a clearwell and this reflected the conditions in the existing model, it was determined that this is acceptable.

The model scenarios are shown in Figure 2 and described in further detail below.

Figure 2. Modeled Water Supply Options

Antioch Scenarios
The Antioch scenarios (1A and 1B) evaluated supplying 6 MGD of water from the City of Antioch brackish desalination facility through an 18-inch pipe into the northwest corner of the distribution system. This scenario was modeled both with the existing active groundwater supply wells operating under current pumping rates, and with all wells inactive to represent a scenario where the wells are deemed unusable due to water quality concerns. Model results showed that there was not a significant change in distribution system performance with the wells active or not active, as shown in Figure 3 (Scenario 1A) and Figure 4 (Scenario 1B). The pressures and velocities did not show a significant difference from the other scenarios.

Figure 3. Scenario 1A: Antioch with Wells

Figure 4. Scenario 1B: Antioch without Wells

New WTP Scenarios
The New Water Treatment Plant (WTP) scenarios looked at the development of a new WTP in the southeast corner of Zone 1, either along Balfour Road or Concord Avenue. Under the Balfour Road WTP scenario (Scenario 2A), two plant locations were considered, both of which would ultimately provide the same quantity of water (16.5 MGD) into the same point in the distribution system through a 30-inch pipe. Because of this, they were hydraulically identical for modeling purposes.

The results of this scenario are shown in Figure 5. The pressures and velocities did not show a significant difference from the other scenarios.

Figure 5. Scenario 2A: Balfour Road WTP
Under the Concord Avenue WTP scenario (Scenario 2B), the new WTP would supply 16.5 MGD through a 30-inch pipe into a different connection point in Zone 1. The results of this scenario are

shown in Figure 6. The pressures and velocities did not show a significant difference from the other scenarios.

Figure 6. Scenario 2A: Concord Avenue WTP

ROGW Scenario
The Reverse Osmosis Groundwater (ROGW) scenario looked at the development of a new water treatment facility for the active groundwater supply wells in the City. The existing wells were “deactivated” in the model and the new WTP was added nearby. The WTP would be able to supply 4 MGD of reverse osmosis permeate through a 16-inch line. The pressures and velocities did not show a significant difference from the other scenarios. The results are shown in Figure 7.

Figure 7. Scenario 3: ROGW

Results and Summary
All supply options were modeled in the updated InfoWater model. These modeling scenarios showed that the distribution system is not significantly affected by any of the proposed water supply options. This means that all options are hydraulically viable, and the distribution system performance does not suggest prioritizing one option over the other. No additional improvements are needed to accommodate the additional supply regardless of the supply source or location, beyond what is identified in the Task 4/5 TM. Some areas in the City were found to have pressures outside of the City’s design criteria, which is not related to the water supply options but could be analyzed through a separate modeling effort.

CITY COUNCIL AGENDA ITEM NO. G.5
05/27/2025
SUBJECT: Provide the City Council with requested information related to increasing the Affordable Housing Ordinance’s 13% obligation DEPARTMENT: Community Development Department
STAFF: Ken Murphy, Acting Community Development Director Sylvia Elias, Senior Housing Analyst

TITLE/RECOMMENDATION
The purpose of this item is to provide the City Council with requested information related to increasing the Affordable Housing Ordinance’s 13% obligation. It is recommended that the City Council provide direction on the following:

1. Whether to increase the affordability percentage requirement of 13% and, if so, to what percentage;

2. If changes are recommended, how to allocate the new affordability percentage requirement to the affordable income categories; and

3. Whether to conduct an economic feasibility study to support an increase in the affordability percentage requirement, if one is sought.

FISCAL IMPACT
If required, a feasibility study could cost approximately $40,000 to $150,000 depending on the scope of work regarding the potential changes to the Affordable Housing Ordinance requirements and how the changes could affect various types of rental and ownership housing developments in Brentwood. In addition, there would be outside legal costs, the extent of which would depend on the nature of the changes to the Affordable Housing Ordinance, but would likely cost at least $5,000 and likely more, depending on the scope of the proposed changes.

There is currently no budget allocated for a feasibility study. If the City Council directs staff to prepare a study, then staff would return to the Council with an estimated cost and a request for a budget amendment for the feasibility study and legal fees which would be funded by the Affordable Housing In-Lieu Fee Fund.

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BACKGROUND

COUNCIL REQUEST
At its March 12, 2024 meeting, the City Council directed staff to bring forth a future agenda item to discuss options related to increasing the Affordable Housing Ordinance’s 13% affordable housing obligation. The Council directed staff to provide information related to an increase in the affordable housing obligation to 15% or 20%.

The City’s current Affordable Housing Ordinance (attached) was adopted by the City Council in 2022 and applies to residential developments of five or more lots:
 Residential developments consisting of five to nine dwelling units are required to either (a) construct one low-income affordable unit, or (b) pay a fee equal to fifty percent of the low-income in-lieu fee.
 Projects of ten or more dwelling units are required to construct or make possible the construction of a minimum of 13% of the total number of dwelling units within the residential development as affordable units.

An “alternative equivalent” (as defined in the Ordinance) to the above can also be approved by the City Council.1 These requirements are applied prior to the application of any density bonus request.

If the minimum percentage was increased to 15% or 20%, there would be a slight increase in the number of units created, as illustrated in the below table using a hypothetical single family residential project of 50 units.

Table 1: Hypothetical Affordable Unit Yield
Project Size 13% Affordable 15% Affordable 20% Affordable 50 units 7 units (6.5
rounded up per
the ordinance)
8 units (7.5
rounded up per
the ordinance)
10 units
The Ordinance requires that the affordable units be allocated to specific income levels2, listed in Table 2 below. If the Council directs that the affordable percentage

1 An alternative means of compliance must be provided for residential rental units, per Government Code Section 65850(g).
2 Income guidelines are updated each July 1st. Source: State Department of Housing and Community Development (HCD), US Department of Housing and Urban Development (HUD) and Affordable Housing Model by City of Brentwood Housing Division.

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be increased, they would also need to provide direction on how to allocate the affordable units by income level.

Table 2: Current Affordability Requirements by Income Level Ownership and Rental Development
Very Low-Income Households 3%
Low-Income Households 4%
Moderate-Income Households 6%
TOTAL 13%
RHNA Allocation
At the March 12th City Council meeting, members of the City Council expressed their concern regarding the difficulties in meeting the current Regional Housing Needs Allocation (RHNA) for Brentwood for very low, low and moderate income housing.

Brentwood, along with most cities in the State, does not have enough affordable housing for its lower income residents, and is far from meeting its RHNA for very low, low, and moderate income households. As shown in the above table, an increase in the affordability requirements from 13% to 15% or 20% would produce more units that would apply towards the City’s RHNA requirements. Shown below is Brentwood’s current RHNA obligation (6th Cycle).

Table 3: Brentwood’s RHNA Requirements
Income Level Current RHNA (6th Cycle)
Very Low 402
Low 232
Moderate 247
Above Moderate 641
TOTAL UNITS 1,522
Active Residential Projects
The City has amended its Affordable Housing Ordinance several times since it was first adopted in 2003. Under state law, the City can only apply the version of the City’s inclusionary ordinance that was in effect when the application was deemed complete, or when a preliminary application under SB 330 was filed. Therefore, the City is currently processing residential development applications that have different affordability requirements due to the timing of the applications. Table 3 below lists

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current active residential projects and which affordable requirement to which they are subject.

Table 4: Approved and Active Residential Projects
Project Type Total Units Approved
by CC
AH
Ordinance
AH
Obligation/
Units
Approved Projects
7590/7650
Lone Tree
SF 40 6/11/2024 10% 1VL/2L/1M
Birch Street
Duplex
SF 2 Approved
administratively
13% N/A
Bridle Gate SF 272 8/27/24
12/10/24
10% 8VL/11L/8M
Inez Estates SF 11 3/28/23 10% 1L
Jacobson
Residence
SF 1 N/A N/A Paid in-lieu fee
Kayla Place
Residences
SF 2 10/15/24* N/A N/A
O’Hara
Apartments
MF 26 4/8/24 13% 1VL/1L/1M
Trinity Estates SF 4 6/27/23 13% N/A
Orchard
Grove North
SF 34 8/13/24 13% 2VL/2M
St. James
Court
SF 8 1/21/25* N/A N/A
Trinity Estates SF 4 6/27/23 N/A N/A
Projects Under Construction
1015 Natwick
Way
SF 1 3/10/22* N/A N/A
Chandler SF 48 11/15/18 2% Paid in-lieu fee
Hanson Lane SF 94 10/24/23 10% 5VL/4L/3M
Kindred &
Balfour
SF 14 3/11/14 2% N/A

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Project Type Total Units Approved
by CC
AH
Ordinance
AH
Obligation/
Units
The Meadows SF 140 8/28/18 N/A DA
Orchard Grove
South
SF 51 9/13/2022 2% 1L/5M
Orchard Trails SF 77 9/13/22 2% 2L
Parkside Villas SF 36 9/12/06* 10% 1L and Paid
$1M in-lieu
Toor Residence SF 1 N/A N/A Paid in-lieu fee
Trilogy @
Vineyards
SF 1085 2004 N/A Paid in-lieu fee
Trumark
Trailside
SF 63 8/8/23 10% 2VL/2L/2M
Development Applications In Review
6905
Brentwood
Blvd
SF 5 TBD 13% TBD
Brady
Residence
SF 1 TBD 13% N/A
Creekside
Mixed Use
MF 270 TBD N/A All AH units -
Moderate
Emblem MF/SF 415
(315
Apartments/1
56 DuplexCondos)
TBD 13% TBD
Enclave
(Mixed Use)
MF 170 TBD 13% TBD
Enclave
(North)
MF 160 TBD 13% TBD
Enclave
(South)
MF 170 TBD 13% TBD
Minnesota
Avenue
SF 4 TBD N/A N/A
DA = Development Agreement N/A = Not Applicable; less than required units per AH ordinance or 100% affordable units *Approved by Planning Commission or Design Review Committee VL = Very Low Income Unit L = Low Income Unit M = Moderate Income Unit

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Other Cities’ Affordable Housing Requirements
For Council’s reference, staff conducted a brief survey of t h e affordable housing inclusionary requirements of other cities in the region. These are listed below in Table 5. Please note that several cities have varying percentage requirements depending on the target household income for the affordable units.

Table 5: Affordable Housing Inclusionary Ordinance Requirement – Other Cities (as of 2024)
City/County Population Affordable Housing Requirement
Contra Costa County
Brentwood 64,811 13%
Antioch 115,632 None. (Inclusionary housing program being studied) Clayton 10,683 10%
Concord 121,513 10%
Contra Costa County 174,289 15%
Danville 42,567 10% (20 units or less), 15% (21+ units) El Cerrito 25,700 10% rental, 12% ownership
Hercules 26,063 10%
Lafayette 24,808 15%
Martinez 36,439 None.

Moraga 16,784 10%
Oakley 45,736 None.

Orinda 19,191 None.

Pinole 18,192 15%
Pittsburg 75,085 6%–15% rental, 15%-20% owner
Pleasant Hill 33,352 5% or 10% for most housing types
Richmond 112,735 9%-10% rental, 7-10% owner
San Pablo 31,088 None.

San Ramon 82,525 15%
Walnut Creek 69,433 6%-10%
Alameda County
Alameda 78,071 15%
Albany 20,325 15%
Berkeley 125,327 20% (feasibility being evaluated)

CITY COUNCIL AGENDA ITEM NO. G.5
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City/County Population Affordable Housing Requirement
Dublin 72,917 12.5%
Emeryville 13,314 15% rental, 20% ownership
Fremont 229,250 10% rental, 15% ownership
Hayward 159,770 6% rental, 7.5% or 12% ownership
Livermore 84,828 10% in Downtown, 15% outside Downtown
Newark 46,635 Rental only– 10% in Downtown, 15% outside Pleasanton Downtown 75,960 15% multifamily, 20% single family San Leandro 87,098 15%
Union City 66,432 15%

LEGAL CONSIDERATIONS
Any increase in the percentage of affordable units required by local ordinance triggers certain legal considerations that the City Council may wish to consider.

Constitutional Matters
First, the City’s ability to impose affordable housing requirements is subject to state and federal laws, including Constitutional protections. When a city imposes a price control on housing, such as rent control or inclusionary housing, the regulation cannot be such that it would create a regulatory taking. Thus, in the context of inclusionary housing, the required percentage of affordable units cannot be so high as to be “confiscatory.” According to the California Supreme Court, that means the ordinance must allow a developer a “fair and reasonable” rate of return.”3 3 To date there are no cases that specifically address what is a “fair and reasonable” rate of return in the inclusionary context.

State Housing Law Issues
Separate and apart from Constitutional considerations, the City must also examine if the ordinance is a constraint on housing production as part of the City’s Housing Element. HCD required the City to analyze the impacts of its inclusionary ordinance on the “cost, supply, and timing of housing,” and this analysis was included in the City’s adopted Housing Element.

Even if HCD does not demand a study under AB 1505 (discussed below), it may question whether an increase in required affordable units acts as a constraint on

3 California Bldg. Industry Ass’n v. City of San Jose (2015) 61 Cal.4th 435.

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housing. Preparation of an economic feasibility study can resolve this potential issue.

FEASIBILITY STUDY
Because of Constitutional takings law and, in particular, HCD’s demands when reviewing Housing Elements, cities typically conduct an economic feasibility study before increasing the required percentage of affordable housing above 15%. The purpose of the economic feasibility study is to demonstrate that the inclusionary ordinance does not constrain housing production and provides housing developers with a reasonable rate of return, as required by the Constitution. The study would then support the Housing Element, serve as the required feasibility study if HCD demands one, and demonstrate that the ordinance is not confiscatory.

As passed in 2017, Assembly Bill 1505 (AB 1505; Government Code Section 65850.01) provides that HCD, among other things, can require that local governments submit an economic feasibility study if specified conditions exist. The proposed changes to the City’s inclusionary ordinance could meet several of those conditions:
 Rental Inclusionary: AB 1505 only applies to ordinances with rental inclusionary requirements. Ordinances that only impose obligations on ownership housing do not trigger requirements under AB 1505. (The City’s ordinance contains rental inclusionary requirements.)
 Ordinance adopted or amended after September 15, 2017: Local governments that adopt or amend ordinances after September 15, 2017 may be required to submit economic feasibility studies to HCD, if they meet the conditions discussed below. ( Proposed changes to the City’s ordinance would be adopted post September 15, 2017.)
 Level of Affordability: Only inclusionary ordinances that require more than 15% of the total number of units to be rented by lower income households at 80% or less of area median income (AMI) are potentially subject to HCD review under AB 1505. Currently, the City requires only 7% of base density to be affordable to lower income households and so its ordinance is not subject to HCD review.
 HCD Findings: Finally, HCD may review an inclusionary rental-housing ordinance requiring more than 15% lower income housing only if it finds that:
 The jurisdiction failed to meet at least 75% of its share of its abovemoderate income RHNA (prorated based on the length of time within the planning period) over at least a five-year period, based on the jurisdiction’s annual Housing Element report. The City has met more

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than 75% of its above-moderate income RHNA.
 The jurisdiction failed to submit the annual Housing Element report for at least two consecutive years. The City has submitted its annual Housing Element report in a timely manner. Therefore, this provision does not apply.
 If HCD is not satisfied with the City’s economic feasibility study, it can limit the City’s inclusionary requirement for rental housing to no more than 15% lower income households.

Cost and Timing
A feasibility study requires a complex technical analysis, therefore, an outside consultant would be required to complete it. The study could cost $40,000 to $150,000 depending on the scope of work and take approximately 3 to 12 months to complete depending on the availability of relevant data, number of meetings and time frame for Council consideration. The budget and timeline for feasibility studies vary significantly depending on how many modifications to the AHO requirements are tested, the number of housing types evaluated (e.g. single family and multifamily projects at alternative density and building types), and how the use of State Density Bonus Law is analyzed as developers use the program in many different ways. If the City Council directed staff to prepare a feasibility study, staff would return to the City Council with an estimated cost and budget request for Council approval.

Recommendation
Staff recommends that the City conduct a feasibility study if the Council directs the Affordable Housing Ordinance to be updated with a percentage requirement higher than 15%. Most cities in Contra Costa and Alameda Counties do not have an inclusionary requirement greater than 15%. Staff further recommends that any feasibility study contain, at minimum, the following components:
 Review recently built and approved projects in Brentwood to determine key development characteristics and how State Density Bonus Law (SDBL) has been used in the development of at least five typical types of housing (referred to as housing prototypes), for example, single family homes, small single family homes or duplexes, townhomes, garden style multifamily (with surface parking), and multifamily housing with structured parking.  Gather current information regarding land costs, residential revenues and values, development costs, and return thresholds for the various housing prototypes from real estate and construction publications, recent appraisals, experienced real estate professionals, and published sources.

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 Interview developers undertaking housing developments in Brentwood or nearby cities that include one or more of these housing prototypes to gather their insights regarding housing development conditions, the use of DBL and relevant information regarding land prices, residential revenues, development costs, and return thresholds for the various housing prototypes.  Gather, analyze and summarize the following information for each housing prototype that will be used as key assumptions in the financial analysis:
o Density (units/per acre)
o Typical unit size (square feet) and type (number of bedrooms/baths) o Residential rents and/or sales prices
o Land costs
o Offsite and onsite infrastructure costs
o Building construction costs (residential and parking) o Development impact fees and other municipal fees
o Construction financing, insurance and other soft costs o Financial return thresholds (for example, return on cost or yield on cost)  Analyze and summarize affordable rents and sales prices by bedroom size to households at each target income level in the City’s updated Affordable Housing Ordinance based on County Area-wide Median Income.  Analyze and summarize the difference between market rate and affordable rents and sales prices (referred to as affordability gap).  Prepare financial pro forma models that analyze project feasibility with and without the use of DBL for each of the housing prototypes taking into account these affordability gaps.
 Prepare summary tables and graphs that summarize the results of the financial feasibility analysis for each housing prototype.
 Present a summary of initial findings from the financial feasibility analysis at a meeting with developer stakeholders for review and comment.  Refine the analysis based on these comments.
 Present a summary of refined findings at a public meeting for review and comment prior to City Council consideration.

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DENSITY BONUS ACTIVATION
Units that meet the local inclusionary requirements can also qualify a project for development incentives under State Density Bonus Law (SDBL) (Government Code § 65915, et seq.). SDBL offers developers a host of incentives, concessions, waivers, and other favorable treatment in return for the inclusion of affordable housing units (or other qualifying project features) in development projects. These benefits are triggered once a project includes 5% very low-income units or 10% low or moderate income units. Depending on how the City's inclusionary requirement is allocated between low-income and very low-income households, projects that are required to provide 15% or 20% affordable units could qualify for the following increase in density above what is permitted under local zoning. Although these increases in density are allowed, developers may or may not increase the number of housing units for a variety of reasons, including site constraints or increased construction costs associated with higher density housing. Additionally, as the percentage of affordable units built increases, the associated allowed density increase climbs, as well. The figures shown in Table 6 show the minimum density increases required by law.

Table 6: State Density Bonus Allowances
Percentage of Affordable Units Increase in Allowed Density 5% Very Low or 10% Low 20%
10% Very Low 32.5%
10% Moderate 5%
11% Very Low or 20% Low 35%
15% Very Low or 24% Low 50%
15% Very Low or 24% Low + Additional
5-15% Very Low or Moderate
Up to 100%
Senior housing of 35 units or more (no
required affordability)
20%
Incentives/Concessions
In addition to the density bonus, the City is required to provide one or more incentives or concessions to a project that qualifies for a density bonus (whether or not the applicant chooses to actually use the density bonus for which they qualify). A concession or incentive is defined as:
 a reduction in site development standards or a modification of zoning code or

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architectural design requirements, such as a reduction in setback or minimum square footage requirements; or
 approval of mixed use zoning; or other regulatory incentives or concessions which actually result in identifiable and actual cost reductions.

The number of required incentives or concessions for which a given project is eligible is based on the percentage of affordable units in the project, and the City is required to grant the concession/incentive unless it has substantial evidence that the proposed concession or incentive:
 does not result in identifiable and actual cost reductions;  would have a “specific, adverse impact” on public health or safety or a historic property listed on the California Register that cannot be mitigated; or  would be contrary to state or federal law.

Waivers/Reduction of Development Standards
Projects that qualify for development incentives under the SDBL can avoid local development standards that would conflict with the development of the project as designed by requesting waivers or reductions of these standards. The SDBL allows any developer who is eligible for a density bonus (even if one is not requested) to request development standards to be waived or reduced if the development standard would physically prevent the project from being built at the permitted density and with the granted incentive/concession. The waiver or reduction of a development standard does not count as an incentive/concession, and there is no limit on the number of development standard waivers that may be requested or granted. The City is not required to waive or reduce development standards that would;  have a “specific, adverse impact” on public health or safety, that cannot be mitigated;
 have an adverse impact on a historic property listed on the California Register; or
 would be contrary to state or federal law.

A recent case (Banker’s Hill 150 v. City of San Diego (2022) 74 Cal.App.5th 755) held that waivers must be granted for a project “as designed” unless one of the findings to deny the waiver can be made.

Per the SDBL, projects that are eligible for a density bonus are not required to construct the density bonus units in order to take advantage of the waivers, concessions/incentives allowed under the law. In the last five years, the City

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approved five residential development applications that included a density bonus request. The projects all requested waivers and/or concessions/incentives, but only two of the projects actually proposed to build the density bonus units. Table 7 below lists the projects and the percentage of density bonus requested and approved, if applicable.

Table 7: Recent Density Bonus Requests
Project Proposed
Market Rate
Units
Affordable
Ordinance
Obligation
Proposed
Affordable
Units per
Ordinance
Density
Bonus
Request
Waivers,
concessions,
incentives
requested?
SEECON
Lone Tree
Way
36 10% 1VL
2L
1M
0% Yes
O’Hara
Apartments
21 15%
(AB2011)
2VL
2L
1M
0% Yes
Orchard
Grove
45 2% 1L
5M
2% Yes
Orchard
Grove North
30 13% 2M
2VL

17.2% Yes
Hanson Lane 82 10% 5VL
4L
3M
0% Yes

ECONOMIC FEASIBILITY OF AFFORDABLE HOUSING
Many economic factors impact the production and feasibility of market rate and affordable housing in Brentwood, regardless of what affordable housing requirements the City adopts. New housing development can be costly, time consuming and complex to undertake for the following reasons:
 Developers must make substantial upfront investments to purchase property, obtain governmental approvals, pay applicable municipal fees and permits, undertake site improvements, and secure funding before construction begins. • In Brentwood, the costs of various municipal fees range from about $55,000 per unit for a 1,000 square foot multifamily apartment to about $105,000 per unit for a 3,000 square foot single family home.  Building construction costs are typically the largest component of housing

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development costs and vary significantly depending on the housing design, provision of parking, building construction type, and amenities, and they have increased rapidly over the past 5 to 10 years in the Bay Area.  Regional construction costs for comparable housing types tend to be similar (3-5% variation in Bay Area counties according to Saylor Construction).  The development process may take 5 to 10 years to secure land use approvals, build infrastructure, secure financing and investment, undertake construction, and complete the sale or rental of new housing.
• Changes in the economy, real estate market and legislation create uncertainty and volatility during this multi-year development process.
• Developers must finance or secure investment to pay for development costs until housing is sold or recapitalized, which escalates development costs particularly if interest rates and returns increase as recently occurred.
• This increases risk to the developer, its investors and lenders. For example, housing development costs may increase significantly while revenues may or may not keep pace as development.  Housing market conditions vary significantly across communities and neighborhoods.
• For example, apartment rents and home prices in eastern Contra Costa County are typically lower than cities located closer to the San Francisco Bay.
 According to RentCafe.com, Brentwood’s average rents for existing apartments are about $2.80/SF while those in Lafayette are about $3.20/SF and those in San Francisco are about $4.50/SF.
 For new development to be economically feasible, the proposed project must generate sufficient return (margin/profit) between anticipated revenues and development costs to attract and repay capital considering these risk factors. • Given that construction costs for similar housing types tend to be similar in the region, lower rents and home prices narrows the potential margin (or return) over development costs, which makes feasibility more challenging to achieve.
 High housing costs widen the difference between what it costs to rent or purchase market rate housing and affordable housing at restricted prices (referred to as the affordability gap).
• To evaluate development feasibility, the required provision of onsite

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inclusionary units (and associated limitations on future revenues) must be analyzed by comparing future housing revenues and operating costs considering this affordability gap.
• As the onsite inclusionary percentage increases and/or units are targeted at deeper levels of affordability, new development may not generate sufficient revenues from market rate units to be financially feasible and meet lender and investor underwriting requirements.

Collectively, these factors often make it challenging for developers to undertake new affordable housing developments that are economically feasible in cities like Brentwood.

NEXT STEPS
Staff is seeking the City Council’s direction on the following issues:

1. Whether to increase the Affordable Housing Ordinance affordability percentage requirement from 13% to another percentage.

2. If the required affordability component is increased, how to allocate the new requirement across affordable income categories.

3. Whether to conduct an economic feasibility study to support an increase in the affordability percentage, as recommended by staff. If Council directs staff to conduct a study, staff would return to the Council for approval of the funds for the study. Staff would then circulate an RFP to identify a consultant to prepare the study.

CITY COUNCIL STRATEGIC INITIATIVE
Focus Area 4: Community Development. 4. Provide a diversity of housing opportunities, including equitable distribution of affordable housing for all socioeconomic segments of the Brentwood community.

PREVIOUS ACTION
Previous Action by the City Council is included on Attachment 1.

DATE OF NOTICE
Not Applicable.

ENVIRONMENTAL DETERMINATION
Not Applicable.

CITY COUNCIL AGENDA ITEM NO. G.5
05/27/2025

ALTERNATIVE OPTION(S)
The following are alternative options that the City Council may consider:

1. Leave the affordable housing obligation at current its 13%.

2. Update the affordable housing ordinance to increase the percentage to 15%, which would not require a feasibility study or additional budget to complete.

3. Update the affordable housing ordinance to increase the percentage to 20%, and provide direction on a feasibility study and additional budget.

ATTACHMENT(S)

1. Previous Action(s)

2. Ordinance 1041

PREVIOUS ACTION
Previous actions related to this agenda item that were taken by the Council are listed below. To view prior actions and materials, and Brentwood Municipal Code references in the staff report, as applicable:
 Visit www.brentwoodca.gov/meetings, and select the meeting date(s) desired to see the reference materials and videos.
 Visit www.brentwoodca.gov/municipalcode to research references to the Brentwood Municipal Code and search by the code section(s) cited.

Ordinance 1041 was adopted by the City Council on July 26, 2022 further amending the City of Brentwood’s Affordable Housing Program.

Ordinance 1014 was adopted by the City Council on April 28, 2020 amending the City of Brentwood’s Affordable Housing Program.

ORDINANCE NO. 1041
AN ORDINANCE AMENDING CHAPTER 17. 725 OF THE CITY OF BRENTWOOD MUNICIPAL CODE (" AFFORDABLE HOUSING")
WHEREAS, the City of Brentwood, California ( the " City") is a general law city, duly organized under the constitution and laws of the State of California; and WHEREAS, California Government Code Section 65800, et seq. authorizes cities to adopt and administer zoning laws, ordinances, rules and regulations as a means of implementing that city' s General Plan; and
WHEREAS, on September 9, 2003, the City Council of the City of Brentwood adopted Ordinance 756, establishing the Affordable Housing Program, as recommended by the Planning Commission; and
WHEREAS, the City Council adopted Ordinance No. 790 on January 11, 2005, and amended in its entirety Chapter 17.725 of the City of Brentwood Municipal Code (the " Affordable Housing Ordinance"); and
WHEREAS, the City Council adopted Ordinance No. 842 on April 27, 2007, amending the Affordable Housing Ordinance; and
WHEREAS, the City Council adopted Ordinance No. 874 on July 28, 2009, amending the City' s Affordable Housing Ordinance; and .

WHEREAS, the City Council adopted Ordinance No. 909 on November 13, 2012, amending the City' s Affordable Housing Ordinance; and
WHEREAS, the City Council adopted Ordinance No. 1014 on April 28, 2020, further amending the City's Affordable Housing Ordinance; and
WHEREAS, on November 9, 2021, the City Council directed staff to bring forth a future agenda item to discuss options related to increasing the Affordable Housing Ordinance ( Chapter

17. 725) obligation to a maximum of 25%, and provide information on other cities' affordable housing obligation provisions, and other requested information related to affordable housing; and WHEREAS, on March 22, 2022, the City Council heard a presentation from staff on increasing the Affordable Housing Ordinance' s inclusionary obligation, possible removal of in -lieu fee payment option, use of housing funds for HOA dues for affordable homeowners, and information on the City' s Regional Housing Needs Allocation ( RHNA) and directed staff to return at a future meeting and provide additional information; and WHEREAS, on April 26, 2022, the City Council heard a presentation from staff on requested information relating to affordable housing and increasing the affordable housing obligation, and directed staff to draft potential Affordable Housing Ordinance amendments for Council consideration; and
WHEREAS, acting on such Council direction, staff has prepared an ordinance ( the Ordinance"), which is attached hereto and incorporated herein as Exhibit A; and

WHEREAS, on June 21, 2022, the Planning Commission considered the staff report, the Ordinance, supporting documents, all public comments submitted, and all other appropriate information that was been submitted, and recommended approval of the Ordinance to the City Council.

NOW, THEREFORE BE IT RESOLVED, the City Council of the City of Brentwood does ordain as follows:

SECTION 1. Brentwood Municipal Code Section 17. 870. 008 reads as follows:

No rezoning ofproperty or text amendment shall occur which is inconsistent with the city's community development plan. In making a decision the planning commission and council shall consider the consistency of the proposed action to the community development plan and other applicable city plans, and shall consider whether the proposed action is inappropriate or otherwise contrary to the public interest.

This Ordinance is a zoning text amendment that is consistent with the 2014 City of Brentwood General Plan ( as amended from time to time), insomuch as:
a. The Ordinance will increase the supply of housing to the Brentwood community and will require that "[ a] II affordable units within a residential development shall be comparable to the market - rate units in exterior design, quality, materials, architectural elements and overall construction quality, as well as number and proportion of bedroom types," ( Brentwood Municipal Code Section 17. 725. 003. F.) per Policy H 1- 2 (" Endeavor to ensure the supply of safe, decent, and sound housing for all residents").
b. The Ordinance will assist in meeting the shelter needs of all Brentwood residents by increasing the supply of housing affordable to very -low, low, and moderate income households, per Goal H 1 (" Housing: Provide a diversity of housing opportunities to enhance the City's living environment and to satisfy the shelter needs of all Brentwood residents").
c. The Ordinance will not displace the predominance of single-family home development as Brentwood' s predominant residential product type, but will allow affordable housing developers to request other housing types, per Policy LU 2. 1 Maintain Brentwood' s predominant land use of single family residential while providing for a mix of housing types throughout the community, in accordance with the Housing Element").
d. The Ordinance includes for the possibility of the construction of affordable duets, duplexes, triplexes or fourplexes on corner lots within single-family areas, per Policy LU 2. 8 (" Provide for a variety of residential products through the Zoning Ordinance in order to accommodate the housing needs of all segments of the city' s population").

SECTION 2. The text of Chapter 17. 725 of the Brentwood Municipal Code is hereby repealed in its entirety and is replaced as set forth in Exhibit "A" attached hereto and incorporated herein.

SECTION 3. The Ordinance shall be published in accordance with Government Code Section 36933 by either posting or publishing the Ordinance in accordance with that law. Further, the City Clerk is directed to cause the text adopted in Section 2 above to be entered in the City of Brentwood Municipal Code. This Ordinance shall take effect and be in force 30 days following its adoption.

SECTION 4. The Ordinance is exempt from review under the California Environmental Quality Act ( Public Resources Code §§ 21000, et seq., and the Guidelines for CEQA, 14 CCR 15000, et seq.) because it has no potential to result in either a direct physical change in the environment or a reasonably foreseeable indirect physical change in the environment, per 14 CCR § 15061( b)( 3). Further, the Ordinance is also exempt because it does not apply to any particular housing project at this time and it is thus speculative to evaluate any such future project in the context of consideration of this Ordinance.

THE FOREGOING ORDINANCE was introduced with the first reading waived at a regular meeting of the Brentwood City Council on the 12th day of July 2022 by the following vote:

AYES: Mendoza, Meyer, Rarey, Mayor Bryant
NOES: None
ABSENT: Rodriguez
RECUSED: None
And was adopted with the second reading waived at a regular meeting of the Brentwood City Council on the 26th day of July by the following vote:

AYES: Mendoza, Meyer, Rarey, Rodriguez, and Mayor Bryant NOES: None
ABSENT: None
RECUSE: None
ATT T:
ni4'1zx
Margaret berly, MMC
City Clerk

Exhibit A
Brentwood Municipal Code Chapter 17. 726
This chapter shall be amended to provide as follows, with deleted text sstFwsk4f} rf4 and new text underlined:

Chapter 17. 725 AFFORDABLE HOUSING

17. 725. 001 Title and purpose of provisions.

17. 725. 002 Definitions.

17. 725. 003 General requirements.

17. 725. 004 Alternative equivalent proposal.

17. 725. 005 Implementation procedures.

17. 725. 006 Affordable unit concessions and construction incentives.

17. 725. 007 Affordable housing in lieu fee fund.

17. 725. 008 Brentwood rental housing trust fund.

17. 725. 009 First time homebuyer fund.

17. 725. 010 Enforcement.

17. 725. 011 Waiver.

17. 725. 001 Title and purpose of provisions.

A. Title. The provisions of this chapter shall be known as the " affordable housing program" of this title.

B. Purpose. The purpose of this affordable housing program is to:

1. Enhance the public welfare and assure that further housing development contributes to the attainment of the city' s housing goals as described in the housing element of the general plan, by creating, preserving, maintaining, and protecting housing affordable for households of very low-, low- and moderate -income;

2. Assure that the remaining developable land in the city's planning area is utilized in a manner consistent with the city' s housing policies and needs;

3. Increase the number of affordable housing units in Brentwood in recognition of the insufficient number of existing affordable housing units in relation to the community' s current and future needs, and

4. Assure that new affordable housing units that are constructed are distributed throughout the city as part of mixed -income developments in order to obtain the benefits that flow from economically diverse communities, increase access to opportunity, and affirmatively further fair housing.

17. 725. 002 Definitions.

As used in this chapter, each of the following terms shall be defined as follows:

Affordable housing agreement" means a recorded agreement between the city and a residential developer setting forth the residential developer' s compliance with the requirements of this chapter.

Affordable housing cost" means the cost defined in the California Health and Safety Code Sections 50052. 5 and 50053 ( as may be amended from time to time) for owner -occupied and tenant -occupied units, respectively, and adjusted for assumed household size. The housing manager, on or about July 1 of each calendar year shall publish the maximum affordable housing costs for sales prices and rents as calculated in accordance with the applicable provisions of the California Health and Safety Code.

Affordable unit" means an ownership or rental -housing unit, including senior housing, occupied by and available to households of very low, low and moderate incomes at an affordable housing cost, adjusted for assumed household size as defined in this chapter, with deed restrictions as defined in this chapter in favor of the city.

Assumed household size" means the assumed number of persons residing within a dwelling unit. For the purposes of this chapter, assumed household sizes for affordable units for a given number of bedrooms are as follows, or as may be amended by the California Health and Safety Code.

Assumed
Household
Size 1 2 3 4 5 6 or more
Unit Size Studio 1 Bedroom 2 Bedroom 3 Bedroom 4 Bedroom 5 Bedroom Custom home development" means any residential development being subdivided by one party and sold as individual lots or parcels to separate owners for construction and development of dwelling units.

Divided in -lieu fee" means the total amount of the in -lieu fees due for the residential development at the time of first building permit issuance divided by the total number of market - rate units in the residential development. The divided in -lieu fee shall be adjusted annually in accordance with appropriate factors or indexes as adopted by the cost allocation plan.

Dwelling unit" means a dwelling designed and intended for occupancy by one household.

First time homebuyer" means a household which has not owned its principal place of residence within the last three years.

In -lieu fee" means a fee paid to the city by an applicant in lieu of providing the required affordable units.

Low- income household" means a household whose annual income does not exceed the qualifying limits set for "lower income households" in Section 50079. 5 of the California Health and Safety Code.

Market -rate unit" is defined as a residential unit that is not an affordable unit.

Moderate - income household" means a household whose annual income does not exceed the qualifying limits set for " moderate -income households" in Section 50093 of the California Health and Safety Code and does not include a very low- or low-income household.

Ownership development" means any residential development that includes the creation of one or more additional dwelling units that may be sold individually. An ownership development also includes the conversion of a residential rental development to a residential ownership development.

Refinance and Resale Limitation Agreement and Option to Purchase" means a recorded agreement between the city and an individual homebuyer of an ownership affordable unit documenting resale controls and/ or rent restrictions.

Rental development" means any residential development that creates one or more additional dwelling units that cannot be lawfully sold individually in conformance with the Subdivision Map Act.

Resale controls and/ or rent restrictions" means legal restrictions by which affordable units shall be restricted to ensure that the unit remains affordable to very low-, low- or moderate - income households, as applicable, for a period of not less than forty-five years for ownership units and not less than fifty- five years for rental units, or longer periods if required by state housing or federal law or a financing assistance program. Resale controls for owner -occupied units shall be in the form of resale restrictions, deeds of trust, and/ or other similar documents recorded against the subject property. Rent restrictions for rental units shall be in the form of a regulatory agreement recorded against the subject property.

Residential development" means and includes, without limitation, for -sale single-family dwellings, multiple -family dwellings, groups of dwellings, condominium or townhouse developments, condominium conversions, cooperative developments, mixed use developments that include housing units, manufactured housing, mobilehomes, and residential land subdivisions intended to be sold, leased or rented to the general public.

Very low-income household" means a household whose annual income does not exceed the qualifying limits set for "very low-income households" in Sections 50093 and 50105 of the California Health and Safety Code. " Very low- income households" include " extremely lowincome households" as defined in Sections 50093 and 50106 of the California Health and Safety Code. ( Ord. 1014 § 1, 2020)

17. 725. 003 General requirements.

A. Applicability. This chapter shall apply to all new residential developments of five or more lots or dwelling units designed and intended for residential occupancy in the city. No residential development, other than that exempted in subsection C of this section, shall be undertaken, and no building permits shall be accepted for processing or issued, unless the development has been approved in accordance with this chapter.

B. Affordability Requirement. Developers of residential developments of five or more lots or dwelling units designed and intended for residential occupancy shall construct or make possible the construction of a minimum of s* thirteen percent of the total number of dwelling units within the residential development as affordable units, allocated to income levels as set forth in this chapter, or as provided in an affordable housing agreement which specifies the means of satisfying this chapter. Golmil yen^ inn on lane lard 1 2021 the required pgfgej +'ac_ni 6ernnle+ rtrprc e by Dv e{ her r7crvr—31 2020 cv cv-cmaci- inner %' vvrcn- n„ crnmon+ rrrcnrwcrc- Gede SeGtinr, vcvrrorro6558Q v v vz . r+/ v -n\ v . The foregoing requirement shall be applied prior to the application of a density bonus and no more than once to an approved residential development regardless of changes in its character or ownership, provided that the total number of dwelling units does not change.

1. Residential Developments of Five to Nine Dwelling Units. Developers of residential developments consisting of five to nine dwelling units shall n4a- -either LqLconstruct one lowincome affordable unit meeting the standards in this chapter, or (b) pay a fee equal to fifty percent of the low- income in -lieu fee as established by resolution of the city council.

Alternatively, the applicant may pay Tee equal to fifty nernen+ of the 10W ORGeme OR - lieu fee, as es+;+h1;.+ h...- 1
by resolution of the Gity G06In,. 11nr provide an "alternative equivalent" as established in this chapter, if approved by the City Council as specified in Section 17.725. 004-. However, if all or any portion of a residential development offive to nine dwelling units is later re -subdivided into ten or more parcels or dwelling units, the city' s affordable housing requirement may not be satisfied by payment of an in -lieu fee. 2.

Application to Residential Development of Ten or More Dwelling Units. In applying this requirement toresidential development consisting often or more dwelling units, any decimal fraction less than 0.50 dwelling units shall be disregarded andany decimal fraction equal toor greater than 0.50 dwelling units shall be construed as one dwelling unit. C.

Exemptions. The following are exempt from the provisions ofthis chapter: 1.

Residential development governed by a development agreement expressly precluding compliance with this chapter or an ordinance of this nature. In cases in which the development agreement does not expressly preclude compliance with this chapter, the project shall comply with this chapter; 2.

Replacement housing due to natural disaster ona one for one basis (i.e., one dwelling unit replaced for each legally existing dwelling unit); 3.

Modifications toexisting properties or structures that do not increase thenumber of dwelling units;

4. Residential care facilities with dwelling units that are nonself- sufficient units; that is, they do not include kitchen facilities ( if a project includes both self-sufficient and non -self-sufficient units, only the latter are exempt);

5. Subdivisions consisting of between one and four lots or dwelling units;

6. Development of up to four new dwelling units on an existing residential lot of record;

7. Development of up to three additional dwelling units on a lot zoned to accommodate up to a maximum of four dwelling units, and which already contains at least one existing dwelling unit, provided that the maximum limit of dwelling units is not increased;

8. A residential second unit or accessory dwelling unit ( as defined by state law) on an existing residential lot, subject to compliance with the zoning ordinance;

9. Residential developments whose applications were determined to be complete under Government Code Section 65943 or any successor provision prior to the effective date of the ordinance codified in this chapter, provided that such residential developments shall comply with the predecessor ordinance, resolution, or policy in effect immediately prior to the effective date of the ordinance codified in this chapter;

10. Residential developments exempted by California Government Code Section 65589. 5( o) or successor provision, provided that such residential development shall comply with any predecessor ordinance, resolution, or policy in effect on the date a preliminary application for the development containing all of the information required by Government Code Section 65941. 1 was submitted to the city.

D. Allocation of Affordable Units to Income Levels. Dwelling units located within the Brentwood city limits for very low-, low- and moderate -income households as required by this chapter shall be allocated as follows:

Dllnr•atinn thFGHgh rleG8MbeF 31 ' 020 ( six percent affordability regWiFement\•_ rn - vcv cn-ru rv c cv orTpervcn c-a .. ........,... .

Ownership Development
1 - 0 V
LGW Inneme HA-1 icch1014j
VeFy Low Innnme I- Ini i& eh Id 4_0k

Ownership and Rental Development
Moderate -Income Households 63%
Low -Income Households 4%
Very Low- income Households 3%
Rental 1' ey lnpmej 4
1 n\ A/_ InnnorAAe t- Ieu sehn1.d-s
0 Proiects of 10 or 11 units shall contain one low-income unit; proiects_of 12 to 19 units shall contain one low- income unit and one moderate - income unit; projects of 20 to 26 units shall contain one low-income unit one moderate -income unit, and one very low-income unit; and projects of 27 to 34 units shall contain one low- income unit two moderate -income units, and one very low- income unit. For larger projects the number of units required at each income level shall be calculated to achieve an income distribution as close as possible to that specified in the above table.

E. Concurrent Construction. All affordable units in a residential development or phase of a residential development shall be constructed prior to or concurrently with market -rate units, as set forth, and in the location specified, in a schedule of construction approved by the city and set forth in the affordable housing agreement. The building permits for the last ten percent of the market -rate units shall not be issued until the last affordable unit has been issued a building permit and construction of the last affordable unit has begun.

F. Design and Distribution of Affordable Units. All affordable units within a residential development shall be comparable to the market -rate units in exterior design, quality, materials, architectural elements and overall construction quality, as well as number and proportion of bedroom types. If approved by the planning commission in the design review approval process as specified in Section 17. 725. 006( D), the developer may request an exception to the foregoing in order to reduce the cost of the affordable units by permitting reduced front, side and backyard landscaping and smaller square footage for bedrooms. Otherwise, affordable units shall be comparable to the approved landscape plans, exterior elevations, and bedroom square footage found in the approved plans for the remainder of the residential development. In addition, all affordable units shall include the same or similar interior amenities offered for market -rate units within a residential development. Affordable units shall be dispersed throughout the residential development so as to prevent the concentration of affordable units, unless the planning commission has approved an exception to this standard to accommodate senior housing or to reduce affordable unit costs as described above, or approval of an off -site location has been granted.

1. Very Low- to Medium -Density Zoning. For residential developments with very low- to medium -density zoning designations as defined by the general plan, the affordable unit may be

smaller in size than other models in the residential development. The minimum permissible affordable unit size is one thousand six hundred square feet on a three thousand square foot parcel. As a means to provide massing and lot proportions consistent with the residential development, a duet unit will satisfy the city' s affordable housing requirement. For example, a duet unit can be located on a corner with each duet unit being one thousand six hundred square feet on two separate three thousand square foot parcels.

2. High- to Very High -Density Zoning. For residential developments with high- to very high - density zoning designations as defined by the general plan, the affordable units shall be comparable to market -rate units in square footage.

G. Length of Affordability. All affordable ownership units shall remain affordable for a period of at least forty-five years from date of original occupancy and each subsequent ownership, and all affordable rental units, including any affordable rental units provided as an agreed -upon alternative equivalent proposal pursuant to Section 17. 725. 004, shall remain affordable for a period of at least fifty- five years from the date of the initial rental or leasing period, or longer periods as may be required by state housing law.

H. Concurrently with applicant's submission of a universal application to the city with respect to any proposed residential development subject to this chapter, applicant shall also submit a narrative describing how the proposed residential development will comply with the requirements of this chapter. ( Ord. 1014 § 1, 2020.)

17. 725. 004 Alternative equivalent proposal.

As an alternative to constructing affordable units on site, a residential developer may propose one of the alternative equivalents set forth below to meet the requirements of Section 17. 725. 003. Such proposed alternative shall be processed in accordance with Section 17. 725. 005 of this chapter. An alternative equivalent proposal may include, but is not limited to, payment of an in -lieu fee for ownership development, dedication of vacant developable land, dedication of constructed units to the city' s rental housing program, construction of affordable units on another site, or conversion of existing market -rate units either for -sale or for -rent) within the city to affordable units through acquisition and enforcement of required affordability restrictions consistent with this chapter. All alternative equivalent proposals must be submitted in writing, demonstrate that the alternative equivalent will provide as much or more affordable housing in the city as would be achieved through the construction of required on -site affordable units required under Sections 17. 725. 003( D), be consistent with the city's housing element, and not increase residential segregation. Additionally, for ownership developments, an alternative equivalent proposal must result in an approximately equal geographic distribution of affordable units throughout the city.

A. Approval of Payment of In -Lieu Fees. In -lieu fees may be paid for -.:--(}residential developments consisting of between five and nine dwelling units; or (2) the very lG)W inGew+c The amount
of the in -lieu fee shall be adopted by resolution of the city council, and may be amended from time to time.

1. In -lieu fees for custom home developments shall be paid at time of building permit issuance for each custom home. For each permit pulled, the developer shall pay either the divided in -lieu fee or +n- a lump sum with the total fee, as elected by the developer.

2. In -lieu fees for all other residential developments shall be paid at building permit issuance for each market -rate unit constructed within the development. For each permit pulled, the developer shall pay either the divided in -lieu fee or in a lump sum as with the total fee, as elected by the developer.

3. Except as may otherwise be required by law, the amount of the fee shall be as set forth in the in -lieu fee resolution in effect at the time of payment. In -lieu fees paid to the city shall be deposited into the affordable housing in -lieu fee fund in accordance with Section 17. 725. 007.

4. The in -lieu fee paid by the developer of an ownership development shall be calculated using a market rate median sales price based in -lieu fee. This fee is based on the twelve-month median sales price for a three -bedroom, one thousand five hundred to one thousand seven hundred square foot, market -rate home in Brentwood, minus the current affordable housing cost as defined in the California Health and Safety Code for owner -occupied units for the applicable household income level.

The amount of the in -lieu fee for each affordable unit shall be the difference between the market rate median sales price, calculated as above, and the affordable housing cost for a for - sale three -bedroom unit.

5. Developers of rental developments must construct affordable units on site or satisfy the affordable requirements through an alternative equivalent proposal other than payment of in -lieu fees.
arc equally met through use of app'! r+an" rrn. Rd alterative B. Dedication of Vacant Developable Land. An applicant may dedicate vacant developable land to the city or city -approved nonprofit housing developer in -lieu of constructing a portion of the required affordable units, if the city council finds all of the following:

1. The dedication of vacant land in lieu of constructing affordable units is consistent with this chapter' s goal of creating, preserving, maintaining, and protecting housing for very low-, low- and moderate -income households;

2. The dedicated vacant land is large enough and appropriately zoned to accommodate the number of affordable units that the applicant would otherwise be required to construct by Sections 17. 725. 003( D);

3. The dedicated vacant land is improved with infrastructure and utilities required to serve the property, including, but not limited to, power, telephone, cable, gas, water, sewer and fiber optics, grading, and all applicable fees, taxes, and assessments, including, but not limited to, school and flood control fees, and excluding any affordable housing in -lieu fees, have been or will be paid by the applicant;

4. The dedicated vacant land is located inside the city, or the vacant land will be annexed to the city prior to issuance of any building permits to the applicant for his/her related market - rate dwelling unit(s);

5. That the off -site location would not increase segregation; and

6. That the development of affordable units on the dedicated land will be financially feasible.

C. Off -Site Construction of For -Sale or For -Rent Affordable Units or Conversion of Market - Rate For -Sale or For -Rent Units to Affordable Units. An applicant may construct the required affordable units off site from the proposed market -rate development site by causing the construction of new ownership or rental affordable units or convert existing market -rate ownership or rental affordable units with the approval of the city council and subject to the city council' s approval of each of the following findings and imposition of the following conditions of approval on each tentative map or other entitlement:

1. Required Findings for Construction and Conversion.
a. The construction of the affordable units off site or conversion of the existing market -rate units, excluding mobile -home units and units within cooperative developments, in lieu of constructing affordable units on site is consistent with this chapter. b. The developer has submitted documentation to the satisfaction of the city manager or designee that demonstrates that the construction of the affordable units on site would be impractical or that off -site construction or conversion of market -rate units to affordable units will significantly benefit the city.
c. The residential development will be subject to the conditions of approval set forth in subsection( C)( 3) of this section. The conditions of approval for the market -rate development shall require that any off -site affordable units be governed by resale controls and/ or rent restrictions similar to those required for on -site affordable units. d. The quality and quantity of affordable units constructed off site and market -rate units converted to affordable units shall be equivalent to affordable units that would have been constructed on site to satisfy the city' s affordable housing requirement. e If conversion of existing market -rate units to affordable units is proposed, the proposed conversion is consistent with Government Code Section 65583. 1 and the City may substitute the conversion of these units for the obligation to identify adequate sites in its housing element, as provided in Government Code Section 65583. 1.

2. Additional Finding Required for Construction of Ownership or Rental Affordable Units. a. The conditions of approval and subdivision guarantee for a residential project, or other security such as a cash deposit, are adequate to provide for the construction of the off -site affordable units prior to or concurrently with the completion of the on -site construction of the market -rate units.

3. Required Conditions.
a. Affordable units constructed off site shall be constructed at the time specified in the affordable housing agreement.

b. Affordable units converted from market -rate units shall be both converted and inspected at the time specified in the affordable housing agreement. Market -rate units converted to affordable units shall require inspection by the community development department to ensure that the affordable units are in good condition and repair, and conform to all applicable city building and zoning codes.
c. Existing very low-, low-, or moderate -income -households that occupy market -rate units being converted to affordable units shall not be displaced from those units. If temporary or permanent displacement occurs while the converted units are being repaired or rehabilitated, the developer shall be responsible to pay relocation and moving benefits to the displaced households in accordance with the California Code of Regulations, Title 25, Chapter 6, California Relocation Assistance Guidelines). The calculation of relocation and moving benefits to be provided by developers to temporarily or permanently displaced households shall be submitted to and approved by the city for verification of compliance with the California relocation assistance guidelines.

D. Dedication of Affordable Units to the City of Brentwood. An applicant may dedicate constructed or converted on -site or off -site affordable units to the city' s rental housing program to satisfy the requirements of this chapter. Mobile homes and units within cooperative developments are excluded from dedication. Each unit dedicated to the city shall equate to the construction of two affordable units that would otherwise be required pursuant to Section 17. 725.003( D). °, Y WRits dedicated f^ the „ it rental housing pregFam shall he from the Rfental stream income from these affordable rental units shall be deposited into a Brentwood rental housing trust fund administered by the city' s finance director in accordance with Section 17. 725. 008.

All units dedicated to the city pursuant to this chapter shall meet the following requirements prior to acceptance by the city:

1. All applicable fees ( including development impact fees), capital improvement financing program assessments, and bond interest payments shall have been prepaid by the developer.

2. The units shall be less than twenty years old and in good condition and repair, as verified by an inspection conducted by the community development department. A second such inspection may need to be performed to confirm that any repair punchlist generated by the initial inspection is completed prior to the city's acceptance of the unit into the rental housing program.

3. The developer shall have installed any front yard, side yard, any backyard landscaping and the unit' s interior shall meet the city' s minimum interior finish and appliance requirements.

4. The sprinkler system, window coverings, and all appliances shall have been installed in the unit in accordance with the list of required items maintained by the city manager or designee.

5. Each unit must be on a subdivided parcel in accordance with Government Code Section 66426, 66427, or 66428.

6. The developer shall pay all recording, escrow and title fees involved in the transfer of title to the city, including the costs of a title policy insuring city' s title in a form and with exceptions approved by the city.

E. Other Means of Fulfilling Affordable Housing Requirements. Subject to city manager or designee approval, any developer may fulfill its affordable housing requirement through additional alternative equivalent methods not specifically mentioned in this chapter, including through the provision of rental affordable units by developers of ownership development projects ( in accordance with Government Code Section 65589. 8), provided that the city council determines such alternative results in the same number of affordable units that would have been provided with on -site construction of affordable units and that the affordable units otherwise meet all requirements of subsections F through G of Section 17. 725. 003. ( Ord. 1014 1, 2020)

17. 725. 006 Implementation procedures.

A. Satisfaction of Affordable Housing Requirement. Each proposal for satisfying the city' s affordable housing requirement, together with a proposed affordable housing agreement per subsection B of this section, shall be reviewed by the city manager or designee, considered for recommendation by the city council committee having jurisdiction, and forwarded to the city council for approval on its consent calendar agenda. The requirements of this chapter shall be satisfied by all ownership and rental developments subject to this chapter, unless the applicant receives a waiver under Section 17. 725. 011.

B. Agreements. Prior to the approval of a final map for any residential development, or issuance of a building permit for a unit within a residential development; to which this chapter applies, whichever comes first, the city and the residential developer shall enter into an affordable housing agreement in a form approved by the city attorney. For those residential developments for which affordable units will be constructed or converted on or off site, the affordable housing agreement shall include appropriate resale controls and/ or rent restrictions.

For ownership affordable units, the city and the individual homebuyer shall be required to enter into a recorded refinance and resale limitation agreement in a form approved by the city attorney. The city manager or designee is authorized to execute affordable housing agreements, resale controls and/ or rent restrictions and any other documents necessary to effectuate the implementation of this chapter, provided such agreements and documents are consistent with the requirements of this chapter.

C. Annual Monitoring and Transfer Fees. Agreements involving rental units provided off site or by conversion of market -rate units as specified in Section 17. 725. 004( C) shall require the owner of the affordable rental units to submit an annual monitoring report to the housing division, in a format approved by the city manager. For each affordable rental unit provided hereunder, the current owner may be required to pay an annual monitoring fee for the term of required affordability in the amount set forth in the affordable housing agreement. For each owner -occupied affordable unit provided under this chapter, the current owner may be required to pay a transfer fee for any change of ownership as adopted from time to time by the city council during the term of required affordability in the amount set forth in the refinance and resale limitation agreement.

D. Resale Prices for Affordable Ownership Units. The maximum resale price for an affordable ownership unit and terms of resale to an eligible household shall be set by the community development director pursuant to the affordable housing cost as defined in Section 17. 725. 002( A) and as set forth in a refinance and resale limitation agreement.

E. City's Right of Option to Purchase Affordable Ownership Units. The resale restrictions as set forth in the refinance and resale limitation agreement shall provide that in the event the owner cannot in good faith and despite his/ her best reasonable efforts, locate an eligible household to purchase an affordable ownership unit at an affordable housing cost, the owner shall give written notice of such circumstances, and an option to purchase, to the city. The city shall also have an option to purchase the affordable unit at the maximum resale price, as limited by any applicable affordability restrictions, if the owner defaults on the terms of the refinance and resale limitation agreement.

F. Selection Criteria for Rental or Ownership Units. No household at the time of move -in shall be permitted to rent, purchase or occupy an affordable unit that is required under this chapter unless its qualifications are consistent with this chapter and the housing manager has approved the household' s eligibility. Eligible potential occupants of ownership affordable units must be first-time homebuyers and will be qualified on the basis of household income as defined in this chapter, including all sources of income and assets, the relationship between household size and the size of the available units, and any further criteria required by law and/ or established by the city council. The affordable housing developer shall use an equitable selection method established in conformance with the terms of this chapter and in compliance with state and federal law. Selection of qualified households shall be based on the affordable housing priorities established below:

Priority 1. Eligible applicants for an affordable unit that live or work within Brentwood city limits. Preference will not be allowed if not permitted by state or federal law or other fair housing restrictions.

Priority 2. Other qualified applicants that do not live or work within Brentwood' s city limits.

The community development director shall establish and maintain eligibility selection contact lists for qualified households based on the two housing priority groups mentioned in subsection F of this section. Proof of qualification for a priority group shall be provided by a household before placement on one of the selection contact lists. The lists shall be updated as needed.

By virtue of their position or relationship, city senior management employees and officials and their children, or members of the city' s agencies, authorities, or commissions who have, by the authority of their position, policy making authority or influence affecting city housing programs, are ineligible to occupy an affordable unit. ( Ord. 1014 § 1, 2020)

17. 725. 006 Affordable unit concessions and construction incentives.

For any residential development meeting the requirements specified in Section 17. 725. 003 of this chapter, the city may offer incentives or financial assistance to encourage compliance with this chapter to the extent resources for this purpose are available and approved for such use by the city. In order to provide flexibility in the application of these concessions and incentives, and to ensure that they fit the variety of circumstances and different development projects regularly processed by the city, such incentives may include, but shall not be limited to, any of the following items, applied alone or in any combination upon the city council' s finding that a developer has proven that the incentive is necessary to the financial feasibility of the residential development.

A. Development Processing Fee Deferral. The city manager or designee may approve deferring payment of city processing and plan check fees applicable to the review and processing of the project. The terms and payment schedule of the deferred processing fees shall be subject to the approval of the city manager or designee. In no case shall deferred development processing fees be paid later than occupancy of any of the units in the residential development. In no case shall fees be waived.

B. Development Impact Fee Deferral. The city manager or designee may authorize the deferred payment of development impact fees applicable to the affordable units. Approval of this incentive requires demonstration by the applicant that the deferral increases the project' s feasibility. The applicant must provide appropriate security to ensure future payment of applicable development impact fees. In no case shall deferred development impact fees be paid later than occupancy of any of the units in the residential development. In no case shall fees be waived.

C. Density Bonus. Concurrently with consideration of an application for a residential growth management program allocation, the city may award a density bonus for developments that comply with the very low-, low- or moderate -income affordability provisions of this chapter by constructing units on site, paying the appropriate in lieu fee, providing an acceptable alternative equivalent proposal, or a combination of the above, in accordance with this chapter.

In the event that a development is also eligible for a density bonus pursuant to Government Code Section 65915, the density bonus authorized pursuant to this chapter shall be included in any density bonus obtained pursuant to state law and shall not increase the amount of the density bonus above that afforded by state law. An application for a density bonus must be received concurrently with an application for residential growth management program allotments. The density bonus provided shall initially be set at nine percent above the midpoint of the density range established in the general plan and zoning code. Fractional density bonus units shall be rounded in the manner set forth in Section 17. 725. 003( B)( 2) of this chapter. The density bonus amount shall be periodically reviewed by the city engineer, the community development director, and the housing manager, who will recommend that adjustments, as appropriate, be adopted by resolution of the city council. Density bonus units authorized under this chapter shall be excluded from the affordability requirements specified in Section 17. 725. 003 of this chapter.

D. Flexible Design Standards. The approving body may modify city standards, including design guidelines, for affordable units that reduce the costs of and are necessary to result in identifiable and actual cost reductions to provide for affordable housing, including, but not limited to, the following:

Reduced lot sizes;

2. Reduced setback requirements;

3. Reduced open space requirements;

4. Construction of duets, duplexes, triplexes or fourplexes on corner lots within singlefamily areas;

5. Reduced landscaping requirements;

6. Reduced parking requirements;

7. Height restriction waivers.

The applicant shall be responsible for documenting to the satisfaction of city manager or designee, that the modification is necessary for the financial or other feasibility of the residential development. Except for any standards modified by the planning commission, the residential development must otherwise be consistent with all required general plan, zoning code, Uniform Building Code, and other applicable city regulations and policies.

E. Fast Track Processing. The city manager or designee may authorize prioritized application review and project processing including environmental review, report preparation, entitlement meetings, plan checks and project inspections.

F. Direct Financial Assistance. The city council may authorize provision of direct financial assistance in the form of a loan or grant from collected affordable housing trust funds as described in Section 17. 725. 007 of this code for developments which include dwellings units affordable to very low-, low-, or moderate -income households that exceed minimum affordable unit counts required under Section 17. 725. 003 of this code.

G. Additional Concessions and Incentives. The city council may consider, on a case -by - case basis, at its sole discretion, the provision of additional concessions or incentives consistent with state law and the housing element of the city of Brentwood general plan for residential development projects that exceed the requirements of this chapter. ( Ord. 1014 § 1, 2020)

17. 726. 007 Affordable housing in lieu fee fund.

A. Creation. in -lieu fees shall be deposited into the affordable housing in -lieu fee fund, which is part of the housing enterprise.

B. Use. The finance director shall administer all monies in this fund including any interest earnings. Funds shall be disbursed at the discretion of the city council for the purpose of assisting in the construction of very low-, low- or moderate -income dwelling units, or helping with other affordable housing opportunities. Use of this fund may include the provision of loans to help fund rental housing projects. The finance director is authorized to utilize the city council approved budget to annually fund the city housing operating costs. In addition, the finance director is authorized to make budget adjustments as required to forgive the interfund receivable that has accumulated prior to the adoption of the ordinance codified in this chapter. (Ord. 1014 § 1, 2020)

17. 726. 008 Brentwood rental housing trust fund.

A. Creation. Net rental income from all rental units dedicated to the city' s previous rental housing program shall be deposited into a Brentwood rental housing trust fund, which is part of the housing enterprise.

B. Use. The finance director shall administer all monies in this fund including any interest earnings. All funds other than those specified in subsection C of this section shall be utilized to purchase, construct or repair single- family or multifamily rental unit inside the city limits. Onehalf of the rental income may be utilized from time to time at the city council' s discretion to

further the provision of affordable housing in the city of Brentwood so long as sufficient funds remain to pay for the maintenance and operation of existing affordable housing in the city' s rental housing program.

C. Withholding. The finance director is authorized to utilize the city council approved budget to annually fund the city housing operating costs from the rental stream of these affordable rental units to fund city housing personnel and administrative costs directly related to management and administration of the Brentwood rental housing trust fund and program. The finance director is further authorized to withhold up to an additional fifteen percent of net proceeds from the rental stream to reimburse city development fees and agricultural mitigation fees for these units until the city development fee accounts are whole. ( Ord. 1014 § 1, 2020)

17. 725. 009 First time homebuyer fund.

A. Creation. Contributions to the city's first time homebuyer program in accordance with Section 17. 725. 004( D) shall be deposited into the first time homebuyer fund, which is part of the housing enterprise.

B. Use. The finance director shall administer all monies in this fund, including any interest earnings. All monies in the fund, other than those specified in Section 17. 725. 009( C) shall be loaned to first time homebuyers that qualify as a moderate -income, low-income or very lowincome household, in accordance with terms and provisions of the approved first time homebuyer program approved by the city council.

C. Withholding. The finance director is authorized to utilize the city council approved budget to annually fund the city housing personnel and administrative costs directly related to the management and administration of the first time homebuyer fund and program. ( Ord. 1014 § 1, 2020)

17. 725. 010 Enforcement.

A. General. The city shall enforce this chapter, and its provisions shall be binding on all agents, successors, and assigns of an applicant. The city may suspend or revoke any building permit or approval upon finding a violation of any provision of this chapter. No land use approval, building permit, or occupancy approval shall be granted for any residential development unless it is in compliance herewith, including, but not limited to, actions to revoke, deny, or suspend any permit or development approval.

B. Excessive Sales Price and Rents/ Legal Action. It is unlawful, a public nuisance and a misdemeanor for any person to sell or rent an affordable unit at a price or rent exceeding the maximum allowed under this chapter or to a household not qualified under this chapter, and such person shall be subject to a five hundred dollar fine per month from the date of original noncompliance until the affordable unit is in compliance with this chapter. If the city determines that the sales price or rents in excess of those allowed by operation of this chapter have been charged to a household residing in an affordable unit, the city may take appropriate legal action.

C. Violation Abatement. The city of Brentwood city attorney or the Contra Costa County district attorney, as appropriate, shall be authorized to abate violations of this chapter and to enforce the provisions of this chapter and all implementing regulatory agreements and affordability controls placed on affordable units by civil action, injunctive relief, and any other

proceeding or method permitted by law. Remedies provided for in this chapter shall not preclude the city from any other remedy or relief to which it otherwise would be entitled under law or equity. ( Ord. 1014 § 1, 2020)

17. 726. 011 Waiver.

A. A developer of any project subject to the requirements of this chapter may request that the requirements of this section be waived or modified by the city council, based upon a showing that applying the requirements of this section would result in an unconstitutional taking of property or would result in any other unconstitutional result.

B. Any such request for a waiver shall be made in writing to the city council, submitted to the city concurrently with applicant' s submission of a universal application for any proposed residential development subject to this chapter.

C. The request for waiver shall set forth in detail the factual and legal basis for the claim of waiver or modification. The city council shall consider the request at the public hearing on the permit application. The applicant shall bear the burden of presenting substantial evidence to support the waiver request, including comparable technical information to support applicant' s position.

D. A waiver of an affordable housing requirement may only be approved by the city council to the extent necessary to avoid an unconstitutional result, based upon legal advice provided by or at the behest of the city attorney, after adoption of written findings, based on legal analysis and substantial evidence. The decision of the city council shall be final. If a modification or waiver is granted, any change in use within the project shall invalidate the waiver or modification of the affordable housing requirement, and a new application shall be required for any waiver or modification under this section. ( Ord. 1014 § 1, 2020)