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Sulfur compound levels at the King George Landfill hover at 1,300 per million, when the average landfill has about 40 parts per million. That may be the cause of horrendous odors
By CATHY DYSON
King George County officials and the Virginia Department of Environmental Quality may have discovered what's caused horrendous odors at the landfill.
The amount of a sulfur compound being generated is 32 times higher than what's typically found in landfill waste, said James LaFratta, air compliance engineer with the DEQ in Woodbridge.
The levels of hydrogen sulfide--a gas that smells like rotten eggs--usually average about 40 parts per million in landfills, LaFratta said.
Levels at King George were 1,300 parts per million in June. Officials believe the high amounts were generated by waste ash from a coal-fired power plant in Alexandria.
"They've got a lot of hydrogen sulfide in the gas," LaFratta said. "And humans have a very low threshold [to it]. It doesn't take a lot of gas escaping for people to notice it nearby."
After numerous complaints from residents who live near the landfill, especially those at Oakland Park subdivision, DEQ officials started monitoring the odors in January.
King George supervisors periodically addressed the problem. They said the unusually wet weather in 2009 produced more gas. As a result, Waste Management, which operates the King George facility, drilled more wells to collect more gas.
Then, Waste Management opened its gas-to-energy plant in May. Methane gas, a natural byproduct of landfills, would be processed through the new plant and converted into electricity.
Waste Management fired up its turbines, then did emission tests. Those tests showed the extremely high levels of hydrogen sulfide, LaFratta said.
Waste Management workers believe they pinpointed the source of the problem. The landfill had been accepting waste from a coal-fired power plant in Alexandria. The coal ash had been treated with a sodium sulfate that's typically not a problem by itself, LaFratta said.
But when it mixes with other waste--and moisture--the compound breaks down quickly, causing sulfur to do the same. When the elements team up with hydrogen, the smelly hydrogen sulfide gas is produced.
Ash deposited at the landfill from nearby Birchwood Power Plant is still being accepted at the landfill. Its ash is treated with a lime slurry mix, which creates a calcium sulfide that doesn't break down as quickly or cause the unpleasant smell hydrogen sulfide does, LaFratta said.