A proposal by a Carroll County cement factory to burn Baltimore sewage sludge as a fuel appears to be gathering support after an environmental board unanimously voted in favor of the plan.
The Carroll County Environmental Advisory Council recommended Tuesday approving a zoning amendment that would allow the German-owned Lehigh Cement Co. to store pelletized sludge, known as biosolids, at its factory in Union Bridge.
"We can go along with the proposal if emissions data are better for biosolids than they are for coal," said Sher Horosko, a member of Carroll Air, a community environmental group that formed about six months ago to fight what members call "constant pollution" from the plant. "If they are simply as good as coal, the least we can say is that Lehigh has a sustainable energy source. If it is worse than coal, our presumption is that it will not be allowed."
A pound of dried biosolids could do the work of about a half-pound of coal and will burn cleaner than the thousands of tons of coal that Lehigh burns hourly, company officials said. The company would store as much as 400 tons of sludge, trucked from Synagro-Baltimore LLC, in a new 130-foot silo and later burn it in its kiln at temperatures as high as 3,000 degrees.
The factory would be the first in the United States to burn sludge for fuel, although the practice is widespread in Europe. The final decision on the zoning change rests with the county commissioners.
"I am satisfied that this issue is being vetted enough and that enough questions are being asked and answered," said Commissioner Dean L. Minnich. "I am leaning toward accepting it, if Lehigh can show that biosolids are a good fuel that is environmentally friendly and won't cause a disaster."
The county zoning administrator allowed Lehigh to construct the silo but banned storage of sludge, pointing to a decade-old ordinance that prohibits storage of sludge "whether or not these solids have undergone treatment." Lehigh has appealed that decision, but given the environmental council's decision, the company might withdraw the appeal, said Peter Lukas, Lehigh plant manager.
"The recommendation shows the county understood our arguments," Lukas said. "I think we can move ahead and start building our facility and schedule a second test after everything is in place."
The kiln's high temperatures destroy organic compounds, removing them from the environment, and the resultant ash is incorporated into the cement, company officials said. Lehigh is in the second half of a two-year, state-issued research permit on burning biosolids. The company must secure a permit to burn the biosolids from the Maryland Department of the Environment.
A state-required test burn last year showed slightly elevated levels of nitrogen oxide, MDE officials said. Turning the heat down slightly would result in reduced emissions, Lukas said. Once the new silo is built in about four months, the state will monitor additional test burns.
"This is basically clean, dry material," said James Slater, Carroll's director of environment and resource protection. "There are safeguards and spill-prevention measures in place."
Kevin E. Dayhoff, environmental council chairman, said, "It would be enormously beneficial to find a way to dispose of biosolids in a manner that benefits the environment. Currently, it is land-applied or land-filled. We really dug into this issue hoping to be a neutral sounding ground so that folks could understand the issue. After a thorough review, we are recommending that the commissioners allow storage of biosolids."
The council focused on safe storage of the product and assurances that the community would experience no ill effects, said Slater, who will help draft the zoning amendment.
"Lehigh feels confident that it can make this work," Slater said. "We have a fairly good picture of what Lehigh is proposing, how it will implement the process and what measures it will take to safeguard the community."
Lehigh would procure the biosolids from Synagro, which is paid by Baltimore to haul sludge from the city's Back River and Patapsco wastewater treatment plants. Synagro produces tons of pellets each day from the sludge.
Horosko of Carroll Air said the environmental council moved too quickly and without adequate input from residents.
"Lehigh did everything it was supposed to and we are willing to see what happens," she said. "But we would have rather seen a balanced conversation from our perspective rather than a rush to judgment."
The county commissioners will have to base their decision on the advice of their staff, the state's promise to monitor emissions and the company's reassurances that biosolids are safe. They have no model to study or other jurisdiction's experience to review.
"Lehigh is asking the county commissioners to rule on something that we have had to evaluate on our own," Slater said. "We have no one who has done this before that we can rely on. We are on the cusp."