By Todd Woody | Bloomberg
A little-known climate threat lurks under our feet: rising groundwater that could release toxic chemicals from more than 132,000 contaminated sites in coastal areas of the US. In a first of its kind study, researchers estimated the number of polluted industrial sites and mapped them to areas likely to experience groundwater inundation due to rising seas.
“A lot of people don’t realize that the ocean actually extends under the land in coastal areas, so as the ocean rises, it pushes up the groundwater toward the surface,” said Kristina Hill, an associate professor at the University of California at Berkeley and the lead author of the paper, which was published last week in the journal Earth’s Future.
Factories, fuel stations, military bases and other industrial facilities have left surrounding soil contaminated with carcinogenic chemicals and heavy metals. Some became Superfund sites whose cleanup is overseen by the federal government. Far more are managed by individual states.
When groundwater rises toward the surface, whether from sea level rise or increasingly intense climate-driven storms, those contaminants can leach into it and spread to other waterways, potentially poisoning people and wildlife. Benzene, trichloroethylene (TCE) and other cancer-causing chemicals known as volatile organic compounds can vaporize and enter homes, schools and businesses through sewer pipes or cracks in building foundations.
In 2020, administrators temporarily shuttered a high school in Oakland after TCE was discovered in groundwater beneath the building. They feared it would vaporize and contaminate the air inside.
RELATED: Cottage cheese injections and electric shocks: Emeryville attempts to reclaim toxic soil
Hill and her colleagues identified 326 Superfund sites vulnerable to groundwater rise in coastal areas. In the San Francisco Bay Area, they found more than 5,000 state-managed toxic sites near the coast and extrapolated that there…
Read the full article here