The Humane Society of the United States is threatening to sue 51 swine operations in Iowa, North Carolina and Oklahoma — 28 of those are here, in Iowa.

Peter Brandt, an attorney for the Humane Society, aruges the practice of confining large numbers pollutes the environment with ammonia. Brandt says while there aren’t any guidelines for just how much ammonia a facility can emit, federal law does require transparency.

“These facilities have got to take their responsibilities under the federal laws seriously,” Brandt says. “The companies that operate these facilities have got to recognize that when you have a golf-course-size lake of manure decomposing, you’re going to be emitting a lot of ammonia and you need to report that.”

According to Brandt, the farms the Humane Society is targeting are not filing those reports.

“It’s not a limit on how much ammonia you can emit, but you have to tell people,” Brandt says. “You can’t keep communities in the dark. You can’t keep emergency responders in the dark.”

The attorney says because of the Humane Society’s notification, the farms now have 60 days to report their emissions. If they don’t, Brandt will file a lawsuit. The Humane Society’s lawyer points to an Environmental Protection rule that requires reporting from any facility that released more than 100 pounds of ammonia within a 24-hour period, and according to Brandt the 51 operations threatened with legal action exceed that.

The National Pork Producers Council is reviewing the Humane Society’s notification, but a spokesperson for the group suggests this is an allegation of a paperwork violation rather than a specific allegation of environmental harm.