News 8 On Your Side is investigating toxic chemicals found in drinking water and food.Pennsylvania plans to soon start testing for the chemicals, which have already been detected in the water at Harrisburg International Airport. Steps are being taken there to deal with the issue.The airport has its own sewage treatment facility and water plant."We have own water system, which is fed by a series of groundwater wells," said Timothy Edwards, the executive director of the airport.Sampling of the wells over the last five years showed slightly elevated levels of perfluorooctanoic acid, or PFOA, and perfluorooctanesulfonic acid, or PFOS. The chemicals, which are used in firefighting foam and various consumer products, have been linked to cancer and other health issues.The U.S. Environmental Protection Agency has issued a health advisory for the chemicals of no more than 70 parts per trillion but has not set a maximum contamination level."It certainly is a concern. It's something that we're going to have to monitor very closely," Edwards said.He said there could be multiple sources for the chemicals in the water."Where it is coming from and its initial source, we are unsure of at this time," Edwards said.The airport's fire department uses firefighting foam that contains some of the chemicals. All three trucks at the department have hundreds of gallons of water and firefighting foam on board. In an emergency, the water and foam are mixed together to create something like dish soap.Chief Brian Wheeler said tubes and a basin are used to capture the foam during annual Federal Aviation Administration testing.When testing is complete, Wheeler said, "We'll call a hazardous waste disposal company to come in, vacuum this out and haul it out to the disposal facility."Airport officials said they will continue testing the water for the chemicals and reporting to the Department of Environmental Protection. There are also plans to install a carbon filtration system that's designed to remove the chemicals from the water. According to officials, a systemwide filtration system would cost about $1.5 million.Officials said there have not been chemical levels above the EPA health advisory level since February.