As the Arctic melts from global warming, oceans are rising. And this could cause saltwater to seep into coastal groundwater basins, requiring more treatment of drinking water. Rising sea levels also could increase storm surge flood events. Low-lying sewage treatment plants, such as in the Bay Area, are at risk of flooding as seas rise.
Large amounts of water dumped on a city in hours also can trigger major flooding, another key concern for water systems. In addition to direct infrastructure damage, such as levee failure, flooding can contaminate supplies and wash out water mains. Researchers mapped 440 hazardous facilities in California that could flood from sea level rise by 2100, disproportionately exposing lower-income communities of color to dangerous chemicals.