A mysterious odor in suburban Philadelphia, which led to a voluntary evacuation, was determined to be from gasoline on Monday.
Officials said that gasoline had gotten into the groundwater in the area and had gotten into Skippack townhouses through their sump pumps, The Associated Press reports. It isn't currently known how gas leaked into the area's groundwater.
A voluntary evacuation was suggested for 150 homes Sunday evening after people began reporting a chemical smell, which authorities checked themselves.
According to the Los Angeles Times, those who left were notified that they could go home and Fire Chief Hadyn Marriott said there were no reports of anyone getting sick.
He said that so far there were "absolutely, positively no signs of illness."
Before testing came back on Monday, Marriott noted that the mysterious odor appeared to be coming from the homes' sump pumps. "It is very apparent that it's traveling somehow in that system with the water."
While it was determined that groundwater was contaminated by gasoline, Marriott said that the water authority was insisting that the water supply for Skippack was safe for residents.