Carlton Nabb measures the health of the Transquaking River by the fish he catches in it.Bob Sellers pulls a water sample from the Transquaking River. It will be tested for nitrogen and phosphorus, among other things. (Dave Harp)

When he was young, he could hook perch, catfish, crappies, bass and more in the waterway, which winds through Dorchester County’s farm country on Maryland’s Eastern Shore. In recent years, the 73-year-old said, its waters have been furnishing mostly mud shad, snakehead and other species with unappealing names.

“I’ve lived there all my life, and I’ve seen a drastic change in the fish habitat and the kind of fish in there,” Nabb told a group of residents that had gathered inside a local fire department’s meeting room on a chilly November evening.

Several dozen farmers, fishermen and environmental advocates filed into the wood-paneled room to get information about a chicken-rendering plant’s plans to nearly quadruple the amount of treated wastewater it releases into the Bay tributary.

If Maryland environmental officials approve Valley Proteins’ wastewater permit, the plant’s average discharge will swell from 150,000 gallons per day to 575,000 gallons per day, according to documents the company has submitted to the state.

“The business of this chicken waste coming out of the plant, we need more information about what is exactly going on down there,” Nabb said at the event, which was hosted by the Dorchester Citizens for Planned Growth and the League of Women Voters of the Mid-Shore of Maryland.

Those organizations and two others are raising questions about the expansion project. In a joint eight-page letter to Ben Grumbles, secretary of the Maryland Department of the Environment, they asked last November how the river could achieve its nutrient-reduction targets if the plant’s permit is granted.

The Transquaking was added to the state’s impaired waterways list for nutrient pollution in 2000. That same year, the U.S. Environmental Protection Agency approved pollution caps for the river that target nitrogen and phosphorus, the two major nutrients. The caps require combined reductions of 50 percent for nitrogen and nearly 30 percent for phosphorus from all of the sources in the Transquaking’s 110-square-mile watershed.

So far, water quality is not improving. A decade of water sampling overseen by the Nanticoke Watershed Alliance at a site just downstream from the Valley Proteins facility shows nitrogen levels remaining unchanged and phosphorus amounts trending upward, said Roman Jesien, a scientist with the Maryland Coastal Bays Program and board member with the Dorchester Citizens group.

Valley Proteins, based in Winchester, VA, is one of the nation’s largest rendering companies. Its Linkwood, MD, facility serves as a catch-all for the Shore’s chicken industry. Each week, trucks offload millions of pounds of feathers, blood and guts — what’s left after chickens are processed for human food. The plant boils it down into pet food.

Valley Proteins announced plans to expand the 1950s era facility shortly after purchasing it in 2013. It needs to ramp up production to keep pace with the chicken industry’s growth in the region, said Robert Vogler, the company’s director of environmental affairs. Despite the heavier output of wastewater, upgrades to the facility’s wastewater treatment plant are expected to reduce the nitrogen and phosphorus loads by 25 percent, he said.

“We can understand the individuals and groups that have an interest in protecting the Bay and the [Delmarva] Peninsula having concerns about an expansion such as this,” Vogler added. But “we strive to be good neighbors and conduct business in a way that’s compatible with the community and laws and regulations.”

Alan Girard, head of the Eastern Shore office of the Chesapeake Bay Foundation, a group that also signed the letter to the MDE, contends that the public documents submitted by Valley Proteins don’t make it clear that nutrient loads will be reduced. He would like to know if the company’s plans to divert some of the waste to nearby farmland would simply shift the pollution around.

The new wastewater permit, if approved, would hold Valley Proteins to a different standard than the state’s municipal wastewater treatment plants, Jesien said. Under the state and federal Chesapeake Bay restoration effort, Maryland and other states have set a nitrogen concentration limit of 3 milligrams per liter on municipal plants.

Privately run wastewater treatment plants, such as the one at Valley Proteins, can discharge waste containing up to 8 milligrams per liter — and that’s what the company plans to do, according to permit documents.

“I think they need to ratchet it down a little,” Jesien said.

The Transquaking flows in a southwesterly direction for about 23 miles from East New Market to its mouth at Fishing Bay. It remains a magnet for paddlers and anglers, but it has a troubled environmental track record.

In 2002, scientists with the Maryland Department of Natural Resources detected a stubborn outbreak of Pfiesteria piscicida in the Transquaking. Pfiesteria is a microscopic plant-animal hybrid that can cause massive fish kills and a range of possible health problems, including memory lapses and respiratory irritation. Seven years later, the Dorchester County Health Department warned people against having contact with the water in Higgin’s Mill Pond, which is part of the Transquaking’s headwaters, because of high concentrations of blue-green algae.

The river’s nutrient limit, officially known as a total maximum daily load, was aimed at curbing recurring algae blooms that sapped the water of most of its oxygen.

It’s unclear whether the Transquaking has made progress toward meeting its TMDL or slipped further away from the goal. Neither the MDE nor the EPA have conducted a comprehensive assessment of the river since the TMDL was created.

But environmental advocates worry that it’s heading in the wrong direction. At the time the TMDLs were established in 2000, the rendering plant was the watershed’s sole source of “point” pollution — the kind that can be traced to a specific pipe or drain. Since then, the plant has at least doubled its production output, increasing the amount of wastewater that streams from its outfall.

Although Valley Proteins’ plant remains the largest point-source polluter in the watershed, two additional point sources have joined it since the pollution caps were created, the environmental groups said in the letter. They also asked the MDE to consider the impact of the influx of large poultry-raising operations in the area.

“It is very troubling … that the [Valley Proteins] expansion appears to be going forward without a clear and comprehensive public plan to accommodate the expansion and associated increased discharge in compliance with the Transquaking River TMDL,” the groups wrote.

Another point of contention: The plant is still operating from an MDE wastewater discharge permit that expired in 2006. The agency, though, approved a water withdrawal permit last September allowing Valley Proteins to boost its water usage to an average of 150,000 gallons per day, a 30 percent increase.

If the plant is piping in more water, critics suggest that it must be producing more wastewater as well. “We expect that means more wastewater coming out of the plant, yet we’re still operating under an 18-year-old permit,” Girard said.

MDE spokesman Mark Shaffer downplayed the effect of the additional water usage, saying most of it is destined to evaporate off the plant’s industrial broilers. “Loading limits in the current permit, which remains in full force and effect, ensure that any increase in flows will not be allowed to violate the TMDL requirements,” he said.

The groups behind the letter to the MDE requested a meeting with agency staff to discuss their concerns. Fred Pomeroy, president of Dorchester Citizens for Planned Growth, described the Jan. 22 meeting afterward as a “good exchange.”

Shaffer said in an email that agency officials plan to meet with the groups again in March. The MDE won’t issue a draft permit for the discharge until afterward, he added.