Monroeville, Allegheny County and state officials are investigating the cause of Monday's gasoline spill at a Monroeville Sunoco station.

Frank Salvati, owner of the station at 4830 William Penn Highway, estimated on Tuesday that about 700 gallons of regular-grade gasoline leaked out of at least one of four underground tanks on the property and flowed down Alpine Village Drive.

He said he believes a faulty tank monitor for at least one underground tank caused the spill.

All four underground tank monitors will be replaced as a precaution, said Salvati, who has owned the gas station since 1996.

Salvati hired Groundwater & Environmental Services to pump out gas that leaked into municipal property on Alpine Village Drive, across from the station.

Most of the gas that escaped from the station was recovered, said Monroeville Mayor Gregory Erosenko.

He said he believes the creek near the gas station was not affected.

Pennsylvania Department of Environmental Protection (DEP) officials could not be reached for comment.

Salvati also hired Tanknology, a company that specializes in environmental compliance for petroleum systems, to test the tanks and repair them.

Police officers and firefighters evacuated about 25 families from Alpine Village Drive, Matterhorn Road and Abers Creek Road after a strong gasoline smell was reported in the area at 4:31 p.m. on Monday, said Lt. Steven Pascarella of Monroeville police.

Evacuated families were sent initially to Monroeville Senior Citizens Center, then were given a choice of staying overnight at the Monroeville Red Roof Inn or returning to their homes around 1 a.m. on Tuesday, Pascarella said.

Besides Monroeville police and all five Monroeville volunteer fire companies, agencies including DEP, Pennsylvania Fish and Boat Commission, Monroeville Emergency Management Team, Monroeville Hazardous Materials Team, Allegheny County Emergency Management, Allegheny County Hazardous Materials Team and Allegheny County Fire Marshal's Office also were on the scene, Pascarella said.

Erosenko said the efforts by the emergency responders were organized and professional and Salvati was responsible and cooperative.

Salvati said he will be responsible for repairs to his gas station and hotel expenses for families who stayed overnight, and a state fund for petroleum business professionals will cover the cleanup's cost.