Pollutants of Concern Reconnaissance Monitoring Progress Report, Water Years 2015-2020. SFEI Contribution No. 1061. San Francisco Estuary Institute: Richmond, CA.2021.
The San Francisco Bay polychlorinated biphenyl (PCB) and mercury (Hg) total maximum daily loads (TMDLs) call for implementation of control measures to reduce PCB and Hg loads entering the Bay via stormwater. In 2009, the San Francisco Bay Regional Water Quality Control Board (Regional Water Board) issued the first Municipal Regional Stormwater Permit (MRP). This MRP contained a provision aimed at improving information on stormwater pollutant loads in selected watersheds (Provision C.8.) and piloted a number of management techniques to reduce PCB and Hg loading to the Bay from smaller urbanized tributaries (Provisions C.11. and C.12.). To address C8, a previously developed fixed station loads monitoring technique was refined that incorporated turbidity and stage sensors recording at 5-15 minute intervals with the collection of velocity and water samples using both manual and auto sampling techniques to compute loads. In 2015, the Regional Water Board issued the second iteration of the MRP. “MRP 2.0” placed an increased focus on identifying those watersheds, source areas, and source properties that are potentially the most polluted and are therefore most likely to be cost-effective areas for addressing load-reduction requirements.