ARI SHAPIRO, HOST:
Right in the path of Hurricane Florence, there's an area where pigs far outnumber people. A big worry is the state of hundreds of open-air lagoons filled with manure. Torrential rain could cause them to overflow. Here's NPR's Dan Charles.
DAN CHARLES, BYLINE: Katy Langley lives on the North Carolina coast downstream from a bunch of hog farms, and she thinks about them a lot.
KATY LANGLEY: When you fly over the area, I mean, you can't throw a rock without hitting one.
CHARLES: She works for an environmentalist organization, Sound Rivers.
LANGLEY: You just see these long barns and these big square shapes that looks like Pepto-Bismol pink because swine waste is bright pink - fun fact of the day.
CHARLES: Actually, it's bacteria feeding on the waste that turn the ponds pink. Those lagoons are a little bit like compost piles. It's a cheap way to handle manure, but they're just sitting there open to the weather, thousands of them, with a Category 4 hurricane coming. Langley is worried that a lot of manure is going to end up in the rivers. Farmers are worried, too, like Marlowe Vaughan in Goldsboro, N.C.
MARLOWE VAUGHAN: We're going to probably get, you know, hit on the nose with this, and flooding is our biggest concern.
CHARLES: They spent part of the day on her farm pumping liquid waste out of their lagoons, spraying it as fertilizer on nearby fields so there's more room for rain from Florence. If farmers are doing this, the lagoons should be able to handle almost three feet of rain. But they've never actually had to deal with that much.
I mean, if you got two or three feet of rain, would that flood the lagoon?
VAUGHAN: We don't really know. I mean, we try to pump down as much as we can, but, you know, after that, it's kind of in God's hands. I mean, we're kind of at the mercy of the storm.
CHARLES: Here's the really bad scenario - water starts overflowing, erodes the lagoon walls and the walls collapse, spreading animal waste across the landscape and into rivers. Some lagoons and hog houses could also be inundated by rising rivers. About 60 of them lie within what the state considers the 100-year flood plain. Vaughan's seen other hurricanes. The farm's come through OK, but she says it sounds like Florence could be worse.
VAUGHAN: Well, we really just don't know. We have no idea what's going to happen. But everybody's very, very, very worried and very concerned, so please pray for us (laughter).
CHARLES: Dan Charles, NPR News.