By Lindsay Ward

CHARLEROI, Pa. (KDKA) – Crews discovered that an overflow of gasoline was responsible for causing about 40 homes in Washington County to smell a strong odor for days.

The Charleroi Fire Department was first alerted to the smell on Friday at 11 a.m. in a residence at First Street and Prospect Ave. As the day progressed, more houses and businesses noticed fumes coming up through their sewer drains.

WATCH: KDKA’s Lindsay Ward reports live —

On Monday, crews worked on McKean Avenue, snaking a camera down into the manhole to get a better look at a possible gas leak.

Charleroi Fire Department says they managed to find that the issue stemmed from an overflow of gasoline at the Gulf Station.

They said this caused gas to seep into the ground and then into the sewer lines.

WATCH: Crews find the source of the smell —

While the fumes should go away in a few days, they say the incoming rain will make it worse.

In addition to opening windows, the Charleroi Fire Department is telling residents to flush soapy water down their sewer drains to help control the fumes.

No one has been taken to the hospital, but the Charleroi Fire Department urges anyone who feels sick from the smell to call 911 immediately.