Faulty new equipment at MarkWest Energy Partners' Houston Gas Plant in Washington County sent plumes of black smoke high into the air Sunday and Monday, raising enough public concern that the state Department of Environmental Protection dispatched an inspector.
The problem had been corrected by Tuesday, and the DEP said no violations were apparent, noting the company had previous permission to do smokestack flaring while installing equipment to separate ethane from other liquid gases at the plant along Route 519 in Chartiers.
But John Poister, DEP regional spokesman, said the department is analyzing air-monitoring results while working with MarkWest to "prevent this type of problem in the future."
Over the weekend, while MarkWest installed the equipment, liquid fuels from natural gas drilling were sent up the plant's smokestack to be burned off in open air. The process is known as flaring. But tests of the new equipment produced roiling black clouds of pollution along with giant flames that made it appear from a distance as a major house fire.
"One thing that really helped was that a number of residents sent pictures that showed more than a small problem there and that made the difference when we made the decision to send an inspector there," Mr. Poister said. "There was smoke where it was not supposed to be."
Robert E. McHale, MarkWest spokesman, said the smoke wasn't aesthetically pleasing and product was lost during the burn off. But the system worked as designed from a safety perspective by sending potentially dangerous liquid gases up the smokestack to be burned.
"It was, basically, a hiccup," Mr. McHale said. "That's the best way to think of it, as a hiccup."
John L. Obenour, 84, whose Hornhead Farm sits next to the plant, said he went to the plant Monday to complain after repeated episodes of billowing black smoke found their way to his property. He said he has black soot on his window seals and black streaks on his roof.
Such episodes have happened several times, he said.
"I could detect a smell because the atmosphere was so heavy, as it is," he said. "The last couple of days I could detect that smell and the god-dang black stuff in the air was settling this way and that.
"You can't stop progress, and I never want to be a thorn in their side," he said. "But I also want to have clean air."
Raina Rippel, director of the Environmental Health Project based in Peters, said, "We have had concern for some time about residents' health and safety living in close proximity to this site, and this event magnifies those concerns."
David Templeton: email@example.com or 412-263-1578.