Concentrations of PCBs and Hg in soils, sediments and water in the urbanized Bay Area: Implications for best management

Nonpoint source pollution has been identified nationally, in the State of California, and in the Bay Area as the leading source of degradation of natural waters. The magnitude of nonpoint source pollution is accentuated in coastal areas where human population is high and where pressures from urban development, industrial and commercial activities, and recreational use are the greatest. San Francisco Bay is listed as an impaired water body for PCBs and mercury under Section 303(d) of the federal Clean Water Act . The RWQCB has recently developed Total Maximum Daily Load (TMDL) reports for the Bay for mercury and PCBs.