Why is This Important?

A contaminated site is property with ground or water pollution that jeopardizes public and environmental health. Contaminated sites can adversely impact a community’s economic vitality because safety regulations restrict current use and future development of the sites while site cleanup is often costly and time consuming. The concentration of contaminated sites in low-income communities is of particular concern as those communities are in the greatest need of available property for housing, jobs, and economic development.

What is a Sustainable State?

In a sustainable state the number of contaminated sites decreases over time and new cases of contamination are identified and remediated promptly.

How Are We Doing?

The California State Water Resources Control Board maintains a database of contaminated sites monitored by local and regional water boards. For San Mateo County, the San Francisco Regional Water Quality Control Board manages several soil and groundwater protection programs that have contributed to a dramatic decrease in contaminated sites in the county over the past 10 years.

· At year-end 2010, 434 contaminated sites in San Mateo County were undergoing investigation, monitoring, and cleanup, a decline of 39 percent over the last 10 years. Nineteen of twenty municipalities in the county have fewer contaminated sites today than they did 10 years ago.

· The contaminated sites include 233 with a history of leaking underground storage tanks (typically gas stations), 183 contain other pollutants (e.g., solvents, petroleum, and heavy metals), and the remaining 17 locations are land disposal sites (i.e., landfills). There is one military cleanup site in the county in Half Moon Bay.

· There are no longer any Superfund cleanup sites in San Mateo County.

· The prevalence of contaminated sites (many of which are former underground storage tanks at gas stations) is highly correlated with industrial activity and population. As a result, Redwood City, South San Francisco, and the City of San Mateo have the highest number of contaminated sites.

· The number of contaminated sites is declining among most cities in the county. In Redwood City the number of contaminated sites has decreased by 29 percent since 2000, and in South San Francisco the number of sites has declined by 52 percent.