Carroll factory seeks use of sludge

Lehigh Cement Co. would burn processed sewage in its kilns

`Biosolids' would come from Baltimore

Environmental group members want hearing on the proposal

April 11, 2005|By Mary Gail Hare | Mary Gail Hare,SUN STAFF

Owners of a Carroll County plant want to burn more than 100 tons a day of dried, sanitized sewage from Baltimore's wastewater facilities to make cement, a proposal that the company insists is safe but that has raised concerns from residents.

Lehigh Cement Co. is proposing to use the pelletized sludge - known as a "biosolid" - as an alternative or supplement to the coal it burns in kilns at its factory in Union Bridge, in Western Carroll.

Lehigh, which is based in Allentown, Pa., has asked Carroll County for zoning approval to build two 130-foot silos, one of which would store as much as 400 tons of biosolids. The other would hold products for the company's milling operation.

Lehigh proposes to haul dried sludge by the 20-ton truckload from sewage treatment operations in Baltimore City to its plant. It would take about five truckloads a day to keep the process in operation, plant officials said.

"We would consume about five tons of biosolids per hour and will be using it to enhance or supplant coal," said Peter Lukas, Lehigh's plant manager in Union Bridge. "We would have to fill the silo every three days."

Lukas knows of no similar operation in the United States, but "this is a common practice all over Europe," he said. He said that the heat that would be used would neutralize contaminants and that the process is environmentally safe.

Lehigh's kilns heat limestone to more than 2,000 degrees in the manufacturing of cement.

Residents wary

Residents are leery, even though farmers have used such sludge as fertilizer for years.

"There is a big difference between putting this stuff on land and breathing it in," said Judy Smith, a Union Bridge resident and member of Carroll Air, an environmental group that formed about six months ago.

Lehigh's proposal recently became public when the company asked the county for a zoning ruling on the height of the silos.

"Farmers have to have a license to spread this on the ground," said Sher Horosko, a member of Carroll Air. "We want a hearing where we can speak our concerns, and we want time to study the public health consequences of this operation."

The company also has discussed its plan with state and town officials and conducted a test burn last year. State approval would be necessary before the project could go into operation.

Support from mayor

Union Bridge Mayor Bret Grossnickle says he is not opposed to the idea.

"It is great that they have found something to do with dry sludge," Grossnickle said. "This is no worse for the environment than burning soft coal. If they don't meet [Environmental Protection Agency] standards, they won't be able to do it."

Sewage treatment plants in the United States produce about 6 million tons of sludge annually, according to the EPA. Federal and state agencies generally support biosolid recycling to manage wastewater residuals, with strict regulations. Most of that recycling involves fertilizer products.

City sludge

Baltimore collects and treats up to 250 million gallons of wastewater daily, primarily from Baltimore and Baltimore County, at the Back River and Patapsco treatment plants.

Disposal of the resulting malodorous sludge is a big undertaking. The city uses a variety of methods - including contracts with private disposal firms, spreading it in wet form on farmland for use as fertilizer and converting it into gardening compost at a city-owned facility in Hawkins Point.

City officials hired a hauler in 1988 to take it to a dump out of state, only to have the "poo-poo choo-choo," as it came to be known, make a return to Baltimore after landfill operators across the country refused to take it.

Since 1990, the city has been drying and pelletizing the Back River plant's sludge for use as a fertilizer and fuel.

Lehigh is negotiating with Baltimore City about costs to purchase the material from the treatment plants, Lukas said. The city provided Lehigh free material for the test burn last year.

Test burn

The test resulted in increased nitrogen emissions from the plant and subsequently a failure to meet air-quality standards, according to the Maryland Department of the Environment, which has ordered further testing.

"Their permit application is not complete, and they have not provided enough data to consider a second burn," said Richard McIntire, and MDE spokesman.

The agency would have to approve the process, and McIntire said it is investigating the idea.

"This is the same stuff you can throw on your lawn. It is essentially nitrogen with no significant levels of toxic pollutants. But this is the first time we have had any proposal to burn dried biosolids in a cement kiln," McIntire said.

Lehigh plans a second test, once the silos are installed in about three months, Lukas said.

"I am confident we can meet the standards," he said.

Hedy Alavi, a professor of environmental engineering at the Johns Hopkins University, said there is little information on the environmental effect of burning biosolids for fuel.

Fertilizer uses have been found to be safer, he said.

The county does not advertise a hearing on height variance, but officials notified six neighbors whose properties adjoin Lehigh. None of them appeared at the zoning hearing Tuesday.

"I am going to use the time to research and to consult our code, the county attorney and our environmental specialist," said Neil Ridgely, county zoning administrator.

The hearing has generated questions for the county attorney, Kimberly Millender.

"We are examining whether our zoning allows this type of storage and researching what Lehigh presented," she said.

The plant, which underwent a $270 million renovation three years ago, employs about 250 people and is a major employer in the town of 1,100.

State environmental officials received 26 complaints from residents about the plant, including problems with cement dust, last year. The company agreed in a consent order last month to pay a $90,000 penalty and speed up the timetable for $55 million to $60 million in improvements.

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