TRANSPORTATION, WATER & INFRASTRUCTURE COMMITTEE
Meeting Date: March 18, 2026
Subject: RECEIVE a presentation on the Contra Costa Regional Alternative Compliance (RAC) System - Joint Powers Authority (JPA) and APPROVE the staff recommendation to join the RAC JPA
Submitted For: Warren Lai || Director | PUBLIC WORKS
Department: PUBLIC WORKS || WATERSHED PROGRAM
Referral No: 5
Referral Name: Review projects, plans and legislative matters that may affect the health of the San Francisco Bay and Delta, including but not limited to conveyance, flood control, dredging, climate change, habitat conservation, governance, water storage, drought resilience planning, development of an ordinance regarding polystyrene foam food containers, monitor waste diversion initiatives, and water quality, supply and reliability, consistent with the Board of Supervisors adopted Delta Water Platform.
Presenter: Michele Mancuso || Sr. Watershed Management Planning Specialist | PW
Contact: Michele Mancuso | (925) 313-2236
Referral History:
Contra Costa County (County) is one of 79 permittees under the San Francisco Bay Region Municipal Regional Stormwater Permit (MRP). To comply with the MRP, municipalities implement programs to reduce pollutants, such as oil, trash, sediment, and mercury, carried by rainwater (stormwater) into local creeks and the Bay. The MRP includes a wide variety of requirements related to municipal operations, business inspections, trash controls, stormwater monitoring, pollutant controls, cost reporting, asset management, and development controls. The permit requires development projects to install low impact development (LID) systems, such as bioretention basins or pervious pavement, which slow, spread, and infiltrate runoff from buildings and pavement. LID is required when new construction or reconstruction exceeds 5,000 square feet. Municipalities must also construct LID systems beyond those required for development projects. For the unincorporated County, this includes treating runoff from an additional 5 acres of impervious surface. The County also has separate numeric requirements for legacy pollutants concentrated in older industrial areas along the Bay.
The County has been working with the City of San Pablo, the Contra Costa Clean Water Program, and other cities to develop the Regional Alternative Compliance (RAC) System, which develops an alternative pathway to meet the MRP’s numeric requirements. The RAC System provides local governments and developers with another way to meet their stormwater treatment requirements. Instead of building every system onsite, they can buy “compliance units” - credits for stormwater treatment facilities constructed elsewhere within the County.
The RAC System offers a flexible, cost-effective compliance option, particularly for sites where installing LID is difficult due to space limitations, infrastructure conflicts, or site constraints, such as steep slopes or proximity to creeks. It also enables construction of larger, more strategically located regional treatment facilities, often at a lower cost. Municipalities may use the RAC System to meet their additional LID requirements when they are unable to build sufficient treatment systems within their own jurisdiction.
Stormwater treatment systems must be maintained in perpetuity. The RAC system supports long-term operations and maintenance costs through annual fees paid by the purchasers of compliance units. To collect these fees from private developments, participating Contra Costa municipalities are forming a Joint Powers Authority (JPA). The JPA will create a Community Facilities District (CFD) that collects fees from private projects that buy RAC compliance units. The RAC and CFD will operate only within the jurisdictions of JPA member agencies. As a result, only projects located within participating jurisdictions may buy or sell RAC compliance units, which will limit opportunities in communities that choose not to join.
The County has been a leader in developing the RAC System. Participation in the JPA and CFD will provide the County with additional options for development projects and greater flexibility in meeting MRP requirements. Staff recommend approval of the County’s participation.
County and Clean Water staff will be making a presentation that provides more information regarding the history, development, purpose, and details of the RAC System. A RAC fact sheet and a draft of the Joint Powers Agreement are provided.
Referral Update:
N/A
Recommendation(s)/Next Step(s):
RECEIVE a presentation on the RAC System and APPROVE the staff recommendation to join the RAC JPA.
Fiscal Impact (if any):
This project is funded by Stormwater Utility Assessment Funds and a grant received by the Clean Water Program.