Environmental officials are releasing 40 million gallons (150 million liters) of partially treated wastewater in Mississippi in advance of Hurricane Nate, trying to prevent a worse spill.
The U.S. Environmental Protection Agency is treating wastewater from a closed fertilizer plant to cut acidity, saying it needs to free up storage in case Nate brings heavy rain to two giant mounds of gypsum.
The material is left over from when the Mississippi Phosphates plant in Pascagoula declared bankruptcy and closed in 2014. The site has a history of environmentally damaging spills.
Hurricanes have posed challenges for EPA at a number of polluted sites this summer. The Associated Press reported after Hurricane Harvey that at least seven Superfund sites in and around Houston went underwater during the record-shattering storm.