PCBs TMDL Load Reduction Accounting for Source Control Measures
The urban stormwater wasteload allocation in the San Francisco Bay PCBs Total Maximum Daily Load (TMDL) is 2 kilograms per year (kg/yr), which represents a 90% reduction from the TMDL’s assumed 2003 baseline PCBs load by 2030. Provisions C.11 and C.12 of the San Francisco Bay Municipal Regional Stormwater Permit (MRP) require that the Permittees prepare a PCBs and mercury control measure implementation plan and corresponding reasonable assurance analysis (RAA) that demonstrates quantitatively that the plan will result in mercury load reductions sufficient to attain the mercury TMDL wasteload allocations by 2028 and PCBs load reductions sufficient to attain the PCBs TMDL wasteload allocations by 2030.
Source control programs that have been implemented or are under development include source property identification and abatement, managing PCBs in building materials during demolition, PCBs in electrical utilities, managing PCBs in infrastructure, and various enhanced operation and maintenance practices. Load reductions are also accounted for implementation of green stormwater infrastructure and full trash capture devices. This presentation will provide background on the source control measures and discuss the methodologies used to estimate PCBs load reductions for the RAA.