Developing a Regional Alternative Compliance System in Contra Costa County
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In 2010, the U.S. EPA approved TMDLs for PCBs and mercury for the San Francisco Bay. Studies and modeling conducted to date demonstrate that PCBs and mercury are primarily found in old industrial and old urban land use areas.

However, the current TMDL and NPDES goals for stormwater are distributed based on population. As a result of this spatial mismatch, DACs face a substantial solitary burden to clean up PCBs and mercury pollution in stormwater in their communities (i.e., resulting from negative externalities of historical industrial and commercial practices), while newer communities are compelled to overinvest in GSI in their boundaries that don't provide significant water quality improvements.

To address these and other challenges, the cities of San Pablo, Richmond, and Walnut Creek, along with unincorporated Contra Costa County, are leading the development of a collaborative structure for local governments to tackle the regional TMDL requirements and other stormwater quality compliance needs. The resulting proposed Contra Costa County Regional Alternative Compliance (RAC) System development was funded by an EPA Water Quality Improvement Fund and developed in collaboration with cities, regulatory entities and industry experts across the San Francisco Bay Area (Bay Area).

The Contra Costa County RAC System is intended to provide a flexible, cost-effective, and scientifically defensible compliance option for addressing the green stormwater infrastructure (GSI) and mercury/PCBs control requirements outlined in the San Francisco Bay Municipal Regional Stormwater NPDES Permit (MRP; Order No. R2-2015-0049 and future orders). By using the proposed regional collaborative RAC System structure, local governments would be able to combine resources and leverage community-based public private partnerships (CBP3s) to identify and implement pollutant-reducing GSI projects and programs. This approach to stormwater pollutant compliance can be scaled to a regional level and replicated across the state or nationally.

The MRP requires that Regulated Projects construct low impact development (LID)/GSI facilities on-site or provide alternative compliance consistent with the MRP. The Contra Costa County RAC System creates an optional alternative pathway for MRP Provision C.3 compliance for new development/redevelopment Regulated Projects. Though the proposed Contra Costa County RAC System has been designed to achieve alternative compliance for Regulated Projects, Permittees seeking to purchase GSI retrofits could also participate as System "buyers."

The proposed Contra Costa County RAC System has been developed to meet the requirements of the MRP and will require San Francisco Bay Regional Water Quality Control Board Executive Officer approval. Through the proposed Contra Costa County RAC System, alternative compliance would be achieved through "compliance purchases" made by participating Regulated Projects or other buyers. Compliance purchases would cover capital costs for C.3 compliance at "Off-Site GSI Projects." Off-Site GSI Projects will be sited to maximize pollutant load reductions, such as PCBs, provide cost efficiencies, and provide ancillary environmental benefits including community greening. It is envisioned that participating Regulated Project owners or other buyers would also pay annual ongoing operation and maintenance assessments for the Off-Site GSI Projects.

The presentation will cover the drivers for the Contra Costa County RAC System, the extensive coordination conducted to develop the proposed RAC System, an overview of the RAC System structure, input from legal reviewers, and next steps to implement the RAC System. The presentation will touch on the potential to adapt the proposed Contra Costa County RAC System to other regions in California and how this framework allows for a resilient and sustainable approach to implementation of GSI and other stormwater treatment measures.

Publication Summary

  • Geosyntec Authors: Kelly Havens
  • All Authors: Amanda Booth, Kelly Havens
  • Title: Developing a Regional Alternative Compliance System in Contra Costa County
  • Event or Publication: CASQA 2021
  • Practice Areas: Water and Natural Resources
  • Citation: Geosyntec practitioners will present at California Stormwater Quality Association Virtual Annual Conference on October 26-27, 2021.
  • Date: Wednesday, Oct. 27 at 1:00-1:25 p.m. PST
  • Location: California
  • Publication Type: Platform Presentation