Pennsylvania Power & Light Co. will resume work in May as part of the company's continuing effort to clean up coal tar from the site of a former manufactured gas plant in Columbia, Lancaster County.
PP&L has done work at the site since 1987 and recently reached an agreement with the state Department of Environmental Protection on an extensive cleanup program that uses innovative technology.
The Columbia site, located on Front Street across from the Columbia Municipal Waste Water Treatment plant, is on the federal Superfund list for priority cleanup.
At one time, the Columbia Gas plant was located on the site. The plant heated coal to produce a gas, which was used for lighting and heating in the Columbia area. The plant operated for about 100 years. PP&L operated the plant for 14 years from 1935 to 1949 and, as a former owner, is partly responsible for cleaning up the property.
Coal tar is a by-product created when coal is heated to produce gas. It's a thick, black oily substance that looks and smells like driveway coating and can pose a risk to human health if directly ingested for long periods of time.
"Long before Columbia was designated a Superfund project, PP&L took action to eliminate the biggest risk the site presented to human safety," said Larry Downing, PP&L's community development director for the Lancaster area. "In 1987, we cleaned up all the coal tar on the ground's surface where people could come in contact with it."
Most of the remaining coal tar at the site is contained in two holder pits in the ground. The pits are about 25 feet deep.
Under a consent order signed with the DEP, PP&L will use the innovative technology called the Contained Recovery of Oily Waste, or CROW, to remove coal tar from one of the holders. Coal tar will be pumped directly from the other holder.
PP&L also will investigate if there is additional coal tar in the ground to see if additional cleanup actions are needed.
The CROW system uses a steam injection process. Steam is pumped into the ground through wells. The heat changes the coal tar's ability to flow, allowing it to be pumped to the surface by a series of recovery wells. The mixture is captured and the coal tar removed.
The innovative system has been used successfully at PP&L's Brodhead Creek Superfund site in Stroudsburg, Monroe County.
"We expect remediation of the gas holders to begin in May and to take four to six months to complete," Downing said.
In addition, PP&L will conduct an engineering evaluation and cost analysis related to contaminated sediments in the Susquehanna River near the site. There is an area about 100 feet by 50 feet in the bed of the river that contains coal tar. The coal tar is located under about two feet of clean sediment, Downing said.
"All work at the site is being overseen by the DEP and we have worked closely with the agency to develop an extensive cleanup program," Downing said.