This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

More than 1,300 sites around the country are suspected of being so contaminated, hazardous or polluted – or are at risk of becoming so polluted – that they have been deemed a national cleanup priority. About 100 of those “Superfund” sites are found in California.

The Environmental Protection Agency identifies these as places that pose a risk to people’s health because they have been contaminated by hazardous waste. Since 1980, the agency has taken charge of cleaning up those sites under a law with the nickname “Superfund.” (Its full name is The Comprehensive Environmental Response, Compensation, and Liability Act, or CERCLA.)

California’s Superfund sites include poorly managed waste management, tech manufacturing facilities, and several military bases.

As of July, the EPA lists 96 contaminated places in California on the National Priorities List. “It is a list of the worst hazardous waste sites identified by Superfund,” the EPA explains.

Some of the contamination dates back decades, as is the case of the Del Amo site in Los Angeles County, where synthetic rubber was produced for World War II. Hazardous chemicals ended up leeching into the soil and groundwater. The area, in an industrial part of Torrance, is still undergoing longterm cleanup.

In the Bay Area’s Silicon Valley, several Superfund sites are located at former semiconductor manufacturing plants. AMD in Sunnyvale and Intel in Mountain View contaminated groundwater and soil below their buildings, the EPA says.

A 5,900-acre site in Sacramento County was a chemical and rocket engine manufacturing site under Aerojet and the Cordova Chemical Company. “Both companies have disposed of unknown quantities of hazardous waste chemicals on the property,” the EPA says. The land in Rancho Cordova is undergoing cleanup, the agency says.

In the Central Valley, issues range from an asbestos mine in Coalinga to accidental chemical spills of an herbicide southeast of Bakersfield.

Another ten Superfund sites around the state are linked to military bases. Camp Pendleton in San Diego County, for example, has nine different areas of contamination alone from poorly managed waste, firefighting operations and more. Cleanup there is a major priority because the base includes streams and rivers that feed into the Pacific Ocean.

The EPA maps out every site on an interactive map. Zooming in on the map (below) allows you to see more information about the Superfund sites in your neighborhood or region.

Clicking on a site opens a pop-up window with more information, including the site’s Hazard Ranking System score. That score represents how likely a site is to release harmful substances into the surrounding environment, how toxic the waste on site is, and how many people are (or could be) impacted by the pollution, among other factors. The highest possible score is 100.

See the Superfund sites in your area on the map below:

You can also view a full list of sites and explore the map on the EPA’s website.

Once a site is put on the National Priorities List, the EPA investigates the dangers posed to human health and pursues the best way of cleaning up the problem. The EPA may force the person or company responsible for the pollution to finance the cleanup, or it may take charge of cleanup if no party can be found responsible.

Once a site is fully cleaned up and the EPA determines there’s no further risk to people’s health or the surrounding environment, it can be deleted from the list. The site can then be redeveloped into something new.