North Carolina environmental regulators say several open-air manure pits at hog farms have failed and are spilling pollution.

Department of Environmental Quality Secretary Michael Regan said Monday that the earthen dam at one hog lagoon in Duplin County had been breached.

There were also seven reports of lagoon levels going over their tops or being inundated in Jones and Pender counties.

Regan said state investigators will visit the sites as conditions allow.

The large pits at hog farms hold feces and urine from the animals to be sprayed on nearby fields.

The Associated Press published photos of a hog farm outside Trenton on Sunday where a waste pit was completely submerged under floodwaters. The N.C. Pork Council, an industry trade group, later denied there had been any reports of spills.

An Associated Press photographer who flew over eastern North Carolina on Sunday saw several flooded hog farms along the Trent River. It wasn’t immediately clear if any animals remained inside the long metal buildings ringed by dark water.

Such farms typically have large pits filled with hog urine and feces that can cause significant water contamination if breached or overtopped by floodwaters. State environmental regulators said Sunday they had not yet received any reports of spills.

An AP analysis of location data from hog waste disposal permits shows there are at least 45 active North Carolina farms located in 100-year and 500-year floodplains at risk of being inundated by nearby streams and rivers.

Federal forecasters predicted several rivers would crest at record or near-record levels by Monday, with high water potentially remaining for days. Officials with the N.C. Park Council, and industry trade group, said farmers had prepared for the storm by lowering water levels in their waste ponds and moving animals to higher ground.