Their search led to a broken transmission line near a Conoco-Phillips tank farm along Cherrytree Road, very near the homes. Investigators on the scene believe the cold weather lead to the rupture.
Residents from six homes had been evacuated since this began on Tuesday night, but so far no further evacuations have been ordered. Firefighters checked out nearby homes on Wednesday as the smell of gasoline wafted through the neighborhood.
"They came into my house last night and they checked the basement," said Harry Sprouse. "They said everything was okay there, so I was glad."
Fire crews from as far away as Delaware stood by in case the fumes caught fire.
It began around 9:12 p.m. Tuesday when the Aston Beechwood Fire Department and Aston Police were called out to a home on the 2200 block of Clearview Lane for the report of gas fumes. When they arrived they found that the fumes were also in neighboring homes.
The fire department called the Delaware County Emergency Management Office who, in turn, called the Pennsylvania Emergency Management Agency. PEMA arrived to the scene and determined that there is a gasoline leak in the area.
The neighborhood sits above a series of major gasoline pipelines. The gasoline got into the sewer lines, and some even flowed into the basement of one home with a faulty sewer check valve. By Wednesday night workers from the sewer department had gone in through a manhole and cut off the flow of gasoline.
Residents were also concerned about the ground water.
"My neighbor came over and told me about it so I just dashed right out here because she has public water, she switched to public water when she bought her house, but I still have well," said Julie Pena.
Late Wednesday, workers used high powered vaccum trucks to remove whatever fuel remained in the sewer lines as pipe line experts tried to determine what caused the leak and how much gasoline actually leaked.
The state Department of Environmental Protection has also been monitoring the situation. They're concerned the gasoline may make its way to the sewage treatment plant and into Chester Creek.
There are 34 transmission pipelines that run through Delaware County. They carry gasoline, heating oil and jet fuel - some of it from as far away as Texas.