FINDLAY, Pa. -- State environmental officials are bringing a mobile lab to an Allegheny County elementary school to test the air after residents and teachers complained about the stench from a nearby landfill.

Residents said the landfill has always smelled, but teachers at Wilson Elementary School in Findlay Township's Imperial neighborhood said there were two weeks in February and every day so far in March that the smell has been overpowering and they want it fixed.

Some people in the area complained the smell is giving them headaches.

Officials from the Pennsylvania Department of Environmental Protection will test the air in the area from Monday to Wednesday.

Officials said a frozen pipe at the Imperial landfill caused a backup of gas that made its way into neighboring homes.

The Allegheny County Health Department cited the landfill after receiving dozens of complaints, many of which were received in the past few weeks.

"This is not a hazardous waste landfill. This is a municipal landfill. This is the garbage you and I produce every day. It does have an odor to it. It's probably not terribly harmful to people, but it does have a noxious smell," said health director Bruce Dixon.

A representative for the landfill said the company will investigate to determine if its gas collection system needs to be expanded.

Dixon said that if the company doesn't fix the issue, the county can force the company to do so.