PPL Corporation has installed a $250,000 aeration system at Lake Wallenpaupack to help mitigate a hydrogen sulfide odor that occurs downstream of the Wallenpaupack hydroelectric power plant periodically from mid-July to late September.

“This odor is not a health risk, however, we recognize that it is a nuisance to the community downstream of our power plant along the Lackawaxen River,” said Brad Piatt, PPL’s manager of Peaking Power. “To be a good neighbor, we are doing the best we can to proactively try and find a solution that will work for the community and continue to protect the fish at the lake.”

Starting this week and throughout the sulfide season, PPL will pump air into the lake through a 3,000-foot-long pipe laid along the bottom of the lake in the old Wallenpaupack Creek bed near the water intake for the hydroelectric plant.

The bubbles will help keep higher levels of dissolved oxygen in the area of the plant’s water intake, which should reduce the amount of hydrogen sulfide released to the Lackawaxen River. The system is expected to add enough oxygen to a volume of water equal the amount of water the plant uses in an average day. The amount of oxygen added to the water must be regulated so it does not harm the fish.

Since the odor is periodic and depends on the weather, results may not be measurable until next sulfide season. “We were scheduled to install the system next year but we wanted to try to capture a little data this year so we can make any necessary adjustments and be in full service next summer,” Piatt said.

“We are excited about this new system’s potential to help us meet our commitment to be responsible corporate citizens,” he said.

Hydrogen sulfide gas is formed through a natural process of decomposing vegetation that settles at the bottom of deepwater lakes or reservoirs. During summer months, the warm, oxygenated water remains at the top of the lake while the cold, oxygen-depleted water sinks to the bottom until it mixes again in the fall.

To run the powerhouse turbines at the Wallenpaupack hydroelectric plant, PPL draws a mixture of water from the top and bottom of the lake. This is done to provide the best flow of water into the generating units and to preserve the cool water trout fisheries downstream of the plant, Piatt said.

During the summer months when the plant is operating, the build-up of hydrogen sulfide gas is released when cooler water from the bottom of the lake is discharged into the Lackawaxen River.

“The Lake Wallenpaupack hydrogen sulfide situation is greatly compounded by the large amount of lawn and farm fertilizer runoff,” Piatt said. “No one has ever instituted measures on such a large scale to try to correct this type of problem.”

For the past four years, PPL has worked with experts to gather and review data and develop and test possible treatment options.

Lake Wallenpaupack was built by PPL in 1926 to provide water for the company’s Wallenpaupack hydroelectric power plant. The 5,700-acre lake, on the border of Wayne and Pike counties in the Pocono Mountains, is a valuable regional resource for power generation, drought management and recreation.

PPL Corporation (NYSE: PPL), headquartered in Allentown, Pa., controls more than 12,000 megawatts of generating capacity in the United States, sells energy in key U.S. markets and delivers electricity to nearly 5 million customers in Pennsylvania, the United Kingdom and Latin America. More information is available at www.pplweb.com .