Polychlorinated biphenyls (PCBs) were manufactured in the United States from 1929 to 1977. They were widely used by many industries because of their low electrical conductivity, high boiling point, chemical stability and flame retardant properties. The largest use of PCBs was in electrical equipment, including transformers and capacitors, but they were also widely used in a variety of other applications, including hydraulic fluids, dust control, flame retardants, lubricants, paints, sealants, wood preservatives, inks, dyes and plasticizers. PCBs have also been found in a variety of non-liquid materials, including construction materials such as insulation, roofing and siding materials. In 1979, the U.S. EPA banned the manufacture of PCBs in the United States. Their import, export and distribution in commerce were also banned and PCBs uses were restricted to totally enclosed applications. The U.S. EPA has authorized other minor uses since that time, but the unavailability of PCBs and health and safety concerns effectively ended their use in new applications.
PCBs are often referred to as a “legacy” pollutant, meaning there are relatively few current uses, but past uses have left large amounts of a highly persistent pollutant in the environment. Based on chemical analysis of surface soil and storm drain sediments, the widespread historic use of PCBs apparently resulted in releases throughout the Bay Area urban landscape. Because the use of PCBs is currently limited and strictly regulated, the potential for new releases to the environment appears very limited.
Problem Statement and Regulatory Background
Fish tissue monitoring in San Francisco Bay has revealed bioaccumulation of PCBs and other pollutants. Since 1994, concentrations of selected bioaccumulative pollutants have been measured in Bay fish every three years. The levels of PCBs in Bay fish have not shown clear increasing or decreasing trends over that time period, but appear high enough to pose a health risk to people who consume fish caught in the Bay. As a result, the Office of Environmental Health Hazard Assessment has issued an interim advisory on the consumption of fish from the Bay. The advisory led to the Bay being designated an impaired water body on the Clean Water Act "303(d) list" due to PCBs and other pollutants. In response, the Regional Water Board is developing Total Maximum Daily Load (TMDL)
programs addressing PCBs and other pollutants. The general goal of the PCBs TMDL is to identify and control sources of PCBs to the Bay and improve water quality.
The Program has provided leadership to Bay Area stormwater management agencies in their efforts to assist with development of the Bay PCBs TMDL. This included leading a regional study that characterized the distribution of PCB concentrations in storm water conveyance sediments in Bay Area watersheds (Joint Storm Water Agency Project to Study Urban Sources of Mercury, PCBs and
Organochlorine Pesticides - Final Report). The Program also performed PCBs case studies in selected urban areas where elevated concentrations of PCBs were found during the regional study and coordinated similar case studies by other Bay Area storm water management agencies. The case studies were aimed at beginning to identify PCB sources and controls (see Case Study Investigating
Elevated Levels of PCBs in Storm Drain Sediments in San Jose, California and Year Two Case Study
Investigating Elevated Levels of PCBs in Storm Drain Sediments in San Jose, California) To facilitate regional coordination of the case studies, the Program led a work group of representatives from BASMAA and Water Board staff. The Program's work plans for these studies included a preliminary list of known sites where PCBs were used, stored and/or released in Santa Clara County.
The Program also completed a comprehensive report on efforts to develop methods of controlling discharges of PCBs from Bay Area urban runoff conveyances (Review of Potential Measures to Reduce
Urban Runoff Loads of PCBs to San Francisco Bay). The study describes 1) past, current and planned efforts to identify PCBs control options in the Bay Area, including the PCB case studies 2) management practices currently implemented by Bay Area storm water management agencies that may reduce discharges of PCBs from urban runoff conveyances, and 3) potential additional PCBs storm water control options and some of their advantages, limitations and cost factors.
In addition, the Program continues to actively participate in regional collaborative efforts and work cooperatively with Regional Water Board staff and other stakeholders to address PCBs and other pollutants of concern. Examples include:
- The Program provided funding to the Clean Estuary Partnership (which is now discontinued) and continues to help fund the Regional Monitoring Program.
- Program staff is representing BASMAA on a number of Regional Monitoring Program committees and work groups, including the PCBs strategy work group.
- Program staff represented BASMAA on the Clean Estuary Partnership's PCBs workgroup, which oversaw development of a Conceptual Model/Impairment Assessment Report on PCBs in San Francisco Bay. The report provides a detailed analysis of the status of the impairment and associated uncertainties, and presents a conceptual model that describes sources, estimated loads, and processes that affect the fate of PCB compounds in the Bay.
- Program staff helped represent BASMAA’S interests during development of the Bay PCBs TMDL. This included reviewing the latest revisions of the staff report and Basin Plan Amendment, assisting BASMAA to prepare comments, and working with Regional Water Board staff to refine these documents. Program staff testified on behalf of BASMAA at Regional Water Board hearings on the PCB TMDL in September 2007 and February 2008. The Regional Water Board adopted the TMDL at the February 2008 hearing.
- Program staff is representing BASMAA and providing in-kind support to the Taking Action for Clean Water Proposition 50-funded project. This project is partnering with BASMAA and its member cities to develop Bay Area-specific Best Management Practices to reduce or prevent the release of PCBs from building materials into urban runoff during renovation, maintenance and demolition of buildings and other structures.