Source of mystery odor in suburban Philadelphia under investigation

There have been no signs of illness from a mystery odor that prompted the evacuation of about 150 homes in suburban Philadelphia, officials said on Monday, while waiting for tests to determine the exact cause of what led to the noxious smell.

Residents were allowed to returned to their homes in Skippack, part of Montgomery County, Pa. after air and water samples were sent to four laboratories, Fire Chief Haydn Marriott told a news conference on Monday. Results could come later in the day, he said.

There were “absolutely, positively no signs of illness,” Marriott told reporters.

The odor was reported at about 5:45 p.m. Sunday at the Fairlawn Court townhouses in Skippack. About 150 houses in the development were evacuated because of the smell.

By Monday afternoon, about half of the people had returned to their homes, officials said.

Marriott said basement sump pumps are believed to be the origin of the smell. He said some form of hydrocarbon was involved but that it would take testing to determine the exact cause.

“The highest readings are in the sump pump pits, and we’re only getting the readings in the pits that have water in them,” Marriott said. “It is very apparent that it’s traveling somehow in that system with the water, but it’s hard to tell how and why at this point.”

But Marriott said the substance was found in a system with sealed pipes, so there was little chance of the surrounding area’s water supply being contaminated.

“We did speak to the water authority several times yesterday; they assured us that there was no problem with the water, that they were going to take care of the testing on their end,” he said.

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