Excerpt:
“Groundwater rise and sea level rise are gradual processes that are accelerating,” said Kristina Hill, associate professor at UC Berkeley’s College of Environmental Design, lead author of the study. “It’s a problem tomorrow, and it’s a problem today.”
Dangerous chemicals hiding in the ground around the Bay Area are due to be released by groundwater as it’s pushed closer to the surface with sea level rise, a new study has found. In many cases, it can happen without warning as cancer-causing volatile compounds escape into schools and homes, experts say.
As the sea level rises, it pushes shallow groundwater, the layer of water just underground, closer to the surface — a process that can release contaminants buried in the soil. Groundwater rise, as the phenomenon is called, is an imminent threat to the Bay Area and could impact twice as much land as the rising seas themselves, according to the new study from UC Berkeley.
The study also found that the risk is highest in low-lying areas within the bay with a history of contamination and disproportionately impacts people of color and low-income people who often live in those places. And yet it’s rarely taken into account in planning, researchers say…
The study, which is undergoing peer review, found that risks of inundation from rising groundwater could threaten over 5,200 hazardous sites in the Bay Area, from old gas stations to Superfund sites — locations prioritized by the Environmental Protection Agency for cleanup. That’s with a sea level rise of 3.2 feet, a level that some projections say could be reached by 2050.
But Hill said it’s already happening at a smaller scale, because groundwater levels go up during storms, such as the atmospheric rivers that caused basements and intersections to flood in low-lying parts of Alameda and other coastal cities this winter.
Based on what they found in the Bay Area, the researchers estimate that 326 Superfund sites are at risk from groundwater rise across the United States. The authors say their report is the first to look at how groundwater could threaten hazardous sites, though previous studies have looked at how coastal flooding could do so.
Also on the topic:
“Groundwater rise and New Study Finds Rising Groundwater Is a Major Bay Area Flooding Risk
As recent storms have shown just how vulnerable the Bay Area is to flooding, a new study finds that rising groundwater is a crucial contributor to the region’s flooding challenges.
The study’s goal in four counties — Alameda, Marin, San Francisco and San Mateo — is huge.
“It’s to make the Bay Area the most climate-resilient coastal region in the world,” said Adrian Covert, senior vice president of the Bay Area Council, a business association that helped fund the research.
In partnership with local climate scientists at Pathways Climate Institute, the San Francisco Estuary Institute, UC Berkeley, regional agencies and the counties, the study took existing groundwater levels and imagined how they would push up around the lip of the bay as seas rise. The authors also created maps to provide a high-level overview of this challenge…
