Does air coming from hog confinements contain manure?

Donnelle Eller
The Register

The air leaving Iowa hog confinements contains manure and should be illegal under state law, according to a petition filed with the state.

Four northeast Iowa residents want the Iowa Department of Natural Resources to regulate the release of manure through the air in the same way it regulates the release of liquid manure.

The state requires that manure be retained until it's applied as fertilizer to farm fields, the petition says.

"We contend the 24/7/365 discharge through air vents or blowers contain excreta/waste/manure," according to the petition filed by Bob Watson and Dick Janson, both of Decorah, Larry Stone of Elkader, and Lew Klimesh of Waucoma.

Canadian baby pigs arrive at a farm near Collins, Iowa, in 2004.

The petition argues that farmers are not containing all their manure in between fertilizer applications, said Dan Andersen, an Iowa State University agricultural and biosystems engineering assistant professor.

Retaining manure has always been interpreted as liquid manure, Andersen said. Deciding air emissions contain manure "would be a new interpretation of what the code says."

Whether emissions contain manure is likely a decision a court will make, he said, adding that some particulate matter coming from hog confinements contains bacteria "associated with fecal matter." 

"Does that make it manure? I'm not sure," said Andersen.

The impact to neighbors is likely limited, though, since particulate matter doesn't travel far from the facilities, and the state requires facilities maintain certain distance from neighbors, depending on the size. "Odor might travel a little bit further," he said.

Andersen compared the discussion to smelling a cookie. Are you smelling the cookie or the chemicals coming off of it?

Watson said the petition isn't about odor. It's about compounds being emitted from hog facilities.

Under the state's definition of manure, the petition says, it's "everything that comes off of, or out of a pig ... Basically, everything in a modern hog confinement is included in this definition except the hogs."

Eldon McAfee, an attorney for the Iowa Pork Producers Association, said the Iowa law the petition cites covers water quality, not air emissions.

"It was never intended, nor does it apply by its context, to emissions from a ventilation fan," McAfee said. "It's being taken out of context by the petitioners."

Watson disagreed, adding that the petitioners are planning to take the issue to district court if Iowa DNR doesn't issue a declaratory order.

The state agency says it's still reviewing the petition, which was filed Dec. 28.

If the agency doesn't make a ruling within 60 days, the petition is considered denied and residents can seek judicial review, according to Alex Murphy, Iowa DNR's spokesman.

The answer could have broad ramifications in Iowa, the nation's largest pork producer. Livestock producers raise about 50 million pigs annually.

Hundreds of producers are meeting in Des Moines this week to discuss environmental, regulatory, economic and other issues at the annual Pork Congress.

If the petition were successful, Andersen said pork producers would have to look at ways to add filters to limit releases. And those filters wouldn't work on facilities that use curtains and are open in the summer to provide ventilation.

Even with filters, "there's not a production practice that would completely eliminate" those emissions, he said.

Workers install floor slats at the construction site of Rob Manning's 2,400 head hog confinement building in Dallas County.  Manning says he is building the structure because demand for pork is high and he needs the manure to spread on his fields.

The petition, which includes more than 800 studies, claims that the gases and other compounds coming from hog facilities are harming Iowans' health.

Hog confinement emissions regularly include hydrogen sulfide, ammonia, methane, antibiotic-resistant organisms and particulates.

The petition includes an Iowa study that found rural residents living near large hog confinement operations are nearly three times more likely to carry a dangerous type of bacteria than those who live farther from the farms.

Watson points to another study that finds state regulations around animal feeding operations are often inadequate to protect the health of workers and neighboring residents because they do not include state health departments in the review.

That's the situation despite research that links "chronic exposure to odors ... to headaches, nausea, upset stomach, mood disorders, high blood pressure, and sleep problems."

But McAfee discounted health concerns: "I'm not aware of any scientific evidence proven in court ... where there have been documented medical effects from air emissions," he said.