What are Santa Clara Valley municipalities and others doing to help reduce PCBs and Mercury pollution in the San Francisco Bay?
SCVURPPP and municipal staff have tested stormwater control measures to see which methods work best in different urban settings. For instance, existing public storm drain systems may be modified with devices that collect polluted sediments that wash into streets (e.g. Hydrodynamic Separators). In public & private spaces, development projects can mimic nature’s filtering abilities with plants, soils and porous surfaces (e.g. bioretention areas, pervious pavement in parking lots, and other Green Stormwater Infrastructure). Findings have helped Bay Area municipalities and developers more effectively manage PCBs and mercury in urban runoff.
Managing Sources of PCBs and Mercury in Santa Clara Valley
Over the past two decades, SCVURPPP has continued efforts to reduce PCBs & mercury in urban runoff to prevent environmental pollution.
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- Watershed management areas & source properties
- PCBs in old buildings & infrastructure
- Hg in Household items
- Reducing sediment
- Green Stormwater Infrastructure
Watershed Management Areas and Source Properties
SCVURPPP monitors soil and sediments across the Santa Clara Valley to locate watershed areas that may have sources of PCBs or mercury. When necessary, SCVURPPP has conducted more focused monitoring to find specific source properties within these management areas. This work helps determine the best places for stormwater control measures.
PCBs in Old Buildings and Infrastructure
In the past, PCBs were used in many building materials, including caulking, adhesives, and insulation. The highest concentrations have been found in buildings built from about 1950 through 1980. Because of this, SCVURPPP is participating in a Bay Area-wide effort to help local cities and towns keep PCBs-containing materials from getting into storm drains during building demolitions. SCVURPPP aims to help Santa Clara Valley municipalities better manage PCBs in building materials during the demolition of older buildings, with tools and trainings to help keep pollutants out of stormwater runoff and local waterways.
Also during the 1950s-80s, PCBs may have been used in caulk and sealants applied to storm drain and roadway infrastructure. SCVURPPP continues to consider other possible sources of PCBs in local stormwater that may need to be managed.
Mercury Recycling from Household Items
Mercury is present in older thermostats, thermometers, electrical switches, fluorescent light bulbs, old paint cans and some disposable batteries. SCVURPPP informs residences about the Santa Clara County Environmental Health Department’s Household Hazardous Waste program to collect and recycle mercury-containing items, and reduce mercury in stormwater. Santa Clara County receives hundreds of thousands of pounds of consumer goods with mercury every year.
PCBs and mercury tend to attach to soils and sediment in the environment. Because of this, Santa Clara Valley municipal agencies continue to reduce stormwater pollution by managing sediment locally. Example activities: scheduling regular street sweeping, requiring construction sites to control dust and sediment, and maintaining green stormwater infrastructure to capture polluted sediments in runoff.
SCVURPPP helps measure municipal agencies’ progress at reducing pollution. The Program tracks which pollution management activities have been successful at reducing sediments with PCBs and mercury in storm drains and, where needed, provides information on how to improve. With proper operation & maintenance, sediment controls may help reduce stormwater pollution.
Green Stormwater Infrastructure for PCBs & Mercury
One of the most effective ways to reduce polluted urban runoff from private & public properties has been to mimic the natural environment in urban landscapes. In the Santa Clara Valley, stormwater from thousands of acres of urban land is now filtered through soils, plants and porous surfaces, helping to reduce PCBs and mercury in stormwater reaching the Bay.
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Finding Solutions: Clean Watersheds for a Clean Bay
Bay Area cities, counties and stormwater programs have worked together to help reduce PCBs and mercury in stormwater runoff. With local and federal funding, the Bay Area Stormwater Management Agencies Association (BASMAA) led a Bay-wide effort to reduce urban watershed impacts on the San Francisco Bay.
The CA Department of Health and Bay Area cities & countywide clean water programs, including the City of San Jose and SCVURPPP, were involved in the Clean Watersheds for a Clean Bay project. To learn more, visit BASMAA.org.