The Municipal Regional Stormwater National Pollutant Discharge Elimination System (NPDES) Permit (MRP; Order No. R2-2015-0049) implements the municipal stormwater portion of the polychlorinated biphenyls (PCBs) Total Maximum Daily Loads (TMDLs) for the San Francisco Bay. Provision C.12.e of the MRP requires Permittees collect at least 20 composite samples (throughout the permit area) to investigate PCBs concentrations in caulk and sealants from public roadway and storm drain infrastructure. To achieve compliance with this permit requirement, the Bay Area Stormwater Management Agencies Association (BASMAA) implemented a regional sampling program on behalf of its member agencies.
The goal of the BASMAA Regional Infrastructure Caulk and Sealant Sampling Program was to evaluate, at a limited screening level, whether and in what concentrations PCBs are present in caulks or sealants in public roadway and storm drain infrastructure in the portions of the Bay Area subject to the MRP. This sampling program also contributes to partial fulfillment of pollutants of concern (POC) monitoring required in Provision C.8.f of the MRP to address source identification, one of the five management information needs identified in the MRP. Source identification monitoring focuses on identifying which sources or watershed source areas provide the greatest opportunities for reductions of POCs in urban stormwater runoff.