Avoiding more problems. Regulators keeping watch on toxic waste sites.

Environmental regulators are monitoring more than three dozen toxic waste sites in the path of Hurricane Florence, as well as scores of lowlying water and sewagetreatment plants at risk of flooding.

The Environmental Protection Agency has identified 40 Superfund sites in threatened parts of the Carolinas, Virginia and Maryland, including polluted industrial sites, chemical plants, coastal shipyards and military bases.

EPA spokesman John Konkus said the agency is listening for any reports of oil or hazardous substance spills from first responders, media reports and state and local emergency command posts. He said federal onscene coordinators and equipment stand ready to deploy if needed.

Superfund sites are among the nation’s most highly polluted places. They often contain contaminated soil and toxic waste at risk of spreading if covered over by floodwaters. More than a dozen Superfund sites in the Houston metro area were flooded last year during Hurricane Harvey, with breaches of potentially harmful materials reported at two.

Though it was downgraded to a Category 1 hurricane at landfall Friday, Florence remains a massive storm that will dump trillions of gallons of rain on eastern North Carolina before sweeping across South Carolina. It could take days for the region’s rivers to crest, which is expected to cause widespread flooding.

The worst natural disaster in North Carolina history was Hurricane Floyd in 1999, which dumped nearly 2 feet of rain and flooded a broad swath of the coastal plain, swamping whole towns and dozens of hog farm lagoons containing millions of gallons of untreated urine and feces.

Florence, a slowmoving system that forecasters say could release more than 3 feet of rain in places, could end up being even worse.

Environmental groups said Friday that they were worried that scores of hog lagoons will again burst or be overtopped by flooding, spilling their contents into rivers used as sources of drinking water. Also of concern are more than three dozen coal ash dumps at power plants in the region. The gray ash that remains after coal is burned contains potentially harmful amounts of mercury, arsenic and lead.

Among the Superfund sites most at risk from Florence is Horton Iron and Metal, a former shipbreaking operation and fertilizer manufacturing site in a lowlying floodplain along the Cape Fear River outside Wilmington in North Carolina. The 7.4acre site is heavily contaminated with pesticides, asbestos, toxic metals and cancercausing PCBs.

Also of concern is the sprawling Norfolk Naval Shipyard in Virginia and Marine Corps bases at Cherry Point in North Carolina and at Parris Island in South Carolina.

The shipyard near the mouth of the Chesapeake Bay dates to 1767 and contains contaminated soil and groundwater from more than two centuries’ worth of dumped hazardous chemicals. Hazards at the Marine Corps bases include ground saturated with toxic chemicals, old paint, ash from old trash burn pits and unexploded ordnance.