Pennsylvania Power & Light Co. will start work in May to remove underground coal tar contamination at the site of a former manufactured gas plant in Carlisle that's been out of operation for nearly 50 years.
The plant was located at the intersection of routes 641 and 74. A UGI Utilities Inc. service facility and some retail businesses in the former Middle Atlantic Millwork building are located on the property. PP&L has an electrical substation in the area.
The manufactured gas plant, which made gas by heating coal, operated at the location for about 100 years from 1853 to about 1950. PP&L owned and operated the plant for about 25 years from 1925 to 1949. Following PP&L's ownership, a predecessor company of UGI briefly owned and operated the plant before closing it. PP&L will share cleanup costs with UGI.
"As part of our commitment to work with the state Department of Environmental Protection to investigate any location in Pennsylvania affected by the past operation of PP&L, we have stepped forward to work with the agency to clean up the Carlisle location," said Kathy Wildauer, PP&L's community development director in the Carlisle area. "PP&L is taking action because it's the right thing to do, not because of any enforcement action."
PP&L is the only electric utility in the state with a comprehensive, voluntary agreement with the DEP to investigate and, if necessary, clean up former power plant and gas plant sites.
Prior to the introduction of natural gas, manufactured gas plants operated in many small communities throughout the United States providing gas for heating and lighting of homes and businesses. The Carlisle plant was one of the first manufactured gas plants in the United States.
Coal tar is a by-product created when coal is heated to manufacture gas. It's a thick, black oily substance that looks and smells like driveway coating, and can pose a risk to human health and safety if ingested for long periods of time.
"When these plants were operating, the accepted method for handling excess coal tar was to store it on site," Wildauer said. "The situation in Carlisle is the same as in hundreds of other communities. The responsible action now is to remove the coal tar from the site and to dispose of it properly."
No coal tar has been found on the surface where people could come in contact with it, Wildauer said.
The initial work at the site is expected to take about two to three weeks. PP&L estimates it will require about 50 truckloads to remove the material from the site.
The material is contained in several underground structures that remain from the original plant, including the foundation of a former gas storage holder about 4 feet deep and 60 feet in diameter and three smaller structures. All of the material in the structures will be excavated, removed from the site and properly disposed of.
The DEP has approved the cleanup plan and will oversee work at the location, Wildauer said.
"Coal tar gives off a very strong odor," Wildauer said. "We will take all the precautions we can to reduce the odor, but people in the immediate area most likely will smell the coal tar as it's being removed. We understand that the work will create a temporary inconvenience in the immediate area, and we will do everything we can to alleviate it."
The entire site will be fenced for public safety and plastic will be placed on the fence to stop dust from blowing off the site. To control odor, a foaming agent will be sprayed on any exposed coal tar areas when work is not being done, tarps will be placed over exposed areas, and only small areas will be dug-up at a time.
"All of these actions will help to reduce dust and odor from the site," Wildauer said.
Workers involved in the removal, who are in direct contact with the material, will wear protective clothing, Wildauer said. Cleanup work will be done by a certified hazardous waste remediation contractor.
There is an additional underground structure at the site that contains coal tar. Cleanup work at that location will be done at another time, Wildauer said.