East of the Chesapeake Bay in Maryland, more than 2,000 chicken houses form one of the densest congregations of their kind in the country. The state has enacted some of the nation’s toughest water-quality regulations to prevent the $2.7 billion industry from polluting the Bay and its tributaries.

But state and federal regulations for large animal operations allow them to pollute the air without limits or penalties. The result: Those chicken complexes unleash millions of pounds of ammonia into the air annually.

Environmentalists contend that those emissions may be increasing as poultry operations expand, hampering efforts to clean up the Chesapeake because of one of the most basic laws of Newtonian physics: What goes up must come down. And some of what comes down ultimately winds up in waterways.

An Eastern Shore-based environmental group has filed a lawsuit against the Maryland Department of the Environment in Montgomery County Circuit Court contending that the state should crack down on air emissions to protect waterways. The plaintiff, the Assateague Coastal Trust, argues that when the state recently updated water protection regulations aimed at chicken houses, they should have been broadened to address airborne ammonia.

Normally, air emissions are regulated under the federal Clean Air Act, but it has not been used to control ammonia from agriculture. The U.S. Environmental Protection Agency has long contended it lacks the data to set proper emission standards for industrial-scale animal operations. Under increasing legal pressure to do something about it, the agency in 2005 began studying emissions at dairy, egg, hog and poultry operations. But progress has been slow; the ammonia models for poultry farms are expected to published this summer, according to the agency.

Absent any action to control it under air laws, environmental groups say it should be regulated under water regulations because ammonia is a form of nitrogen that, once it drifts down from the air and enters waterways, can trigger algae blooms that absorb great amounts of oxygen when they die, creating “dead zones” for aquatic life.

“This is the primary pollutant from this industry,” said David Reed, an attorney with the Chesapeake Legal Alliance, which filed the lawsuit last October on behalf of the trust. “It just simply seems a dereliction of their duty not to regulate it.”

To regulate an air pollutant under their water-permitting authority, MDE officials counter, would open a Pandora’s box of red tape. Water permit holders — from all industries, not just agriculture — would have to seek new permits or modify existing ones if their facilities vent pollutants into the air. Air permit holders also might need new approvals if their emissions are found to impact waters.

If the judicial branch sides with the environmental group’s interpretation, said Matthew Standeven, the attorney assigned to the MDE by the state attorney general’s office, the water pollution law would become “completely unworkable.”

The region’s poultry industry is watching the case closely. Since 2009, when the state significantly broadened the scope of its chicken house regulatory program, the raft of rules has withstood several cycles of public comment and judicial review, said James Fisher, a spokesman for the Delmarva Chicken Association. The trade group, he said in a statement, remains confident that “the permit meets the water quality protection standards set by the [EPA].”

Ammonia’s day in court

Regulators at state and federal levels nationwide have long been vexed by the problem of pollution traveling from one medium to another, such as from air to water. The problem, they say, is that the nation’s bedrock environmental laws — the Clean Water Act and the Clean Air Act — were designed to manage pollution within their own lanes. The laws are virtually silent on what happens when a pollutant changes lanes, such as airborne ammonia settling into water.

Under the EPA, large chicken operations are regulated as concentrated animal-feeding operations, or CAFOs, under the Clean Water Act, even though they have substantial air emissions. Pushback from the agricultural community and some members of Congress has long stymied efforts to even monitor those emissions. That could change, though, because of growing concern about the potential impact of those emissions on human health. Ammonia is a major ingredient in soot, a pollutant that can exacerbate a host of respiratory illnesses from asthma to COVID-19.

Like many states, Maryland oversees CAFO water pollution regulations on behalf of the EPA. The state finalized the revision of its “general discharge permit” last July after a lengthy public review period, which included a green light from the EPA. The Assateague Coastal Trust filed its lawsuit in October.

During the case’s hour-long oral arguments on Jan. 26, Judge Sharon Burrell didn’t tip her hand on how she might rule. (She said she would issue a written ruling but didn’t indicate when that would happen.) But Burrell asked several pointed questions about the state’s positions.

She noted that the MDE fully agrees that air is one of the primary pathways for chicken CAFOs to pollute the Bay with nitrogen. “Was it considering this at all [in the development of the water permit] or was it saying, ‘This is somebody else’s department’?” Burrell asked.

“There’s going to be a certain amount of nitrogen pollution that the department believes it can’t regulate through this particular mechanism,” Standeven said.

Another question from Burrell: If the MDE believes it can only address waterborne contaminants from agriculture, why does the agency’s permit instruct farmers on how to grapple with “nuisance odors”? Here, Standeven said, officials were just “being responsive” to concerns raised by residents who live near chicken houses.

Air pollution lies beyond the scope of the Clean Water Act’s intent, he added. The MDE attorney cited a 1997 opinion issued in the 10th Circuit Court of Appeals. In that case, the panel wrote that someone “may be correct in arguing that an object may fly through the air and still be ‘discharged … into the navigable waters’ under the Clean Water Act, [but] common sense dictates that [those] emissions constitute discharges into the air — not water.”

How much is too much?

In chicken operations, the largest source of ammonia is the birds’ urine. Each chicken house is equipped with a battery of giant exhaust fans that draw out the noxious fumes inevitably produced by raising thousands of birds in a confined space.

Researchers have long known that at least some of the ammonia that escapes from Eastern Shore chicken houses tumbles back onto the land and water within the Bay watershed. But determining the precise amount has been complicated.

In 2019, researchers at North Carolina State University compiled the most detailed and wide-ranging figures to date. Their study estimated that 24 million pounds of ammonia fall back onto the Eastern Shore after being emitted by CAFOs – and a portion of that, it stands to reason, falls into Bay tributaries and likely the Bay itself. Attorneys for the Assateague Coastal Trust cited the study’s findings as evidence of the problem.

But the study’s authors admit that their results present more of a worst-case scenario than an exact reflection of reality. Because of a lack of public information about emissions, the analysis assumed that the chicken houses are functioning at full capacity every day of the year, although that is never the case. It also didn’t account for the practices that farmers use to reduce ammonia emissions, such as adding treatments to the chickens’ bedding material.

Familiar foes

The Assateague Coastal Trust, named after the barrier island south of Ocean City, MD that it helped to preserve, has long been a thorn in the chicken industry’s side.

In 2010, the group was one of a handful of organizations that filed a federal lawsuit against a chicken farm in Worcester County contracted to Perdue Farms, accusing it of polluting a Bay tributary. The case centered on an uncovered pile of fertilizer that the plaintiffs claimed was chicken manure. State investigators later determined it to be sewage sludge, a revelation that hampered the litigation. A judge sided against the environmental groups.

In recent years, the Assateague Coastal Trust has turned its attention to the permitting process, securing public hearings on certain projects that would otherwise not have fallen into public view. And it has been one of the most prominent voices for years in favor of state legislation that would set up air monitors around the region’s poultry hot spots.

The bill has gained little traction in Annapolis.

Study to guide the industry’s fate

In the meantime, the MDE has begun conducting a smaller version of the air study that critics had sought, taking measurements at two stations near poultry operations on the Lower Shore – near Pocomoke City and Princess Anne. The results will be compared with two stations that have no chickens nearby – the Horn Point Laboratory west of Cambridge and the Old Town neighborhood in Baltimore.

The year-long measurement phase is expected to end later this spring. MDE officials say they plan to use the information to help determine if any additional steps need to be taken to protect the environment or public health.

Initial results suggest that ammonia counts are much higher in short bursts of time near the chicken houses than at the comparison locations. But, over time, the air quality is not much different between the two locations.

From April to December 2020, the maximum concentration of ammonia in Pocomoke, where chicken CAFOs proliferate, topped out at 177 parts per billion over the course of one particularly high hour. The peak in Baltimore was 27 ppb.

But the average hourly value was about 11 parts ppb near Pocomoke and 6 parts per billion near Princess Anne. In his statement, Fisher of the Delmarva Chicken Association called attention to the Princess Anne average, noting that it was lower than the 7 ppb average recorded at Baltimore.

“In other words, the data collected so far show nearly no difference in average ambient ammonia concentrations between areas with chicken farms and areas without them – and show that average ambient ammonia levels are, in fact, lower in the Princess Anne area than in chicken-farm-free Baltimore,” Fisher said.

None of the readings – whether taken near or far from chicken farms – came close to the MDE’s air-quality threshold for ammonia of 350 ppb per hour.

Environmentalists say the study should include several more locations to truly measure the impact of the industry’s CAFO emissions. And they are leery of whatever the MDE may find, because the Delmarva Chicken Association is one of the study’s main financial supporters. MDE officials, though, say the trade group has no hand in its design or execution.