SCOTT SIMON, HOST:
One of the many striking images to appear after Hurricane Florence is what appears to be a pink pond on a hog farm overflowing into the floodwaters. That pond is actually a hog lagoon, the place where pig waste collects and mixes with water to break down. And when hog lagoons overflow, people downstream are bothered.
We turn now to Mark Rice, who's director of the Animal and Poultry Waste Management Center at North Carolina State University. Mr. Rice, thanks so much for being with us.
MARK RICE: Oh, it's my pleasure. Thank you.
SIMON: Forgive me, I have to ask first - why is it pink?
RICE: (Laughter) Well, it's actually a naturally occurring bacteria that consumes sulfur compounds. And so it's actually - it's beneficial to have it in the lagoon. It helps reduce odor to some extent. And so if you see that, it's - you've got a healthy functioning lagoon.
SIMON: The state of North Carolina says more than 50 hog lagoons have overflowed in the wake of Florence - 75 more might. How common or uncommon is this?
RICE: It's uncommon simply because the producers typically manage the lagoons to have their lagoon levels pumped down to the lowest possible level by hurricane season - so by late August. We learned a lot from previous storms back in the late '90s in how to manage the lagoons. So yeah, it's certainly something we don't want to see. But when you get 30 inches of rainfall, there's going to be some of that, unfortunately.
SIMON: What happens when all this waste overflows?
RICE: It goes into the ecosystem, and it will be assimilated most likely based on past history. What is actually overflows is more dilute than what it would have been without the rain. And then with everything else that's coming down the river, it will get assimilated into the ecosystem one way or another. In a case like this where there's the major flooding, most of the nutrients are going to get carried on out into the ocean.
SIMON: Why in this day and age are there still hog lagoons and we haven't come up with a better way?
RICE: There are better ways. It's just that they're expensive ways. And from a farming standpoint, the margins are typically slim. And so it's just - there's - lagoons are still an effective method for waste treatment and fairly resilient. You know, some of the new systems that have been evaluated were highly mechanical systems, high energy requirements. And so, you know, during a storm event or where there's electricity is off for several days, those systems aren't going to work at all. And so you're still going to have a potential for release of wastewater.
SIMON: Yeah. Mr. Rice, I found myself very affected this week to read that amidst all the devastation and suffering of many people through Hurricane Florence, according to reports, about 5,500 pigs died during the storm.
SIMON: That's a lot.
RICE: It's a small fraction of what could have been if there hadn't been steps taken to move animals from flood-prone areas before the storm. Certainly, it's tragic, but agriculture is a leaky system. It's prone to all sorts of weather-related perils and that's just unfortunately the way it is.
SIMON: Mark Rice, who's director of the Animal and Poultry Waste Management Center at North Carolina State, thanks so much for being with us.
RICE: You're welcome. Thank you.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.