(Bloomberg) -- North Carolina’s hog-manure lagoons have stayed contained so far as the region continues to get pelted with rain from the remnants of Hurricane Florence.

The state’s 4,000 lagoons are holding out, even though huge swaths of farmland in the state’s eastern corner are underwater, Governor Roy Cooper said. The lined earthen pits that hold treated waste had been a major environmental concern as unprecedented rain lashed North Carolina, with at least 10 rivers breaching their banks.

"We are closely monitoring hog lagoons, and we haven’t had any reports of issues," Cooper said in a media briefing Sunday.

Hog farming is one of the biggest industries in North Carolina. Duplin County, where two people have died due to flash flooding, is home to 45 times as many hogs as its human population. Lagoons in the state’s eastern area have flooded in previous hurricanes, causing serious health and safety hazards. Florence was downgraded to a tropical depression early Sunday as winds diminished to 35 miles per hour, but officials said the threat of heavy rainfall persisted.

More than 10 billion pounds of wet animal waste is produced annually in the state, according to a June 2016 report by the Waterkeeper Alliance, a watchdog group. Environmental organizations are preparing to inspect waterways for toxic spills once the storm subsides. North Carolina has more hogs than any U.S. state other than Iowa.

“Rainfall amounts across the region have not exceeded the available capacity of farm lagoons on whole across the industry,” the North Carolina Pork Council said in a statement posted to its website Saturday. “Lagoon levels were low ahead of the storm” after the waste was used as crop fertilizer, the group said.

--With assistance from Megan Durisin.

To contact the reporter on this story: Olivia Carville in New York at ocarville1@bloomberg.net

To contact the editors responsible for this story: James Attwood at jattwood3@bloomberg.net, Millie Munshi, Stephen Merelman

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