Airports have for decades been managing and remediating contamination of soil and groundwater resulting from past practices. However, within the past two years airports have been surprised by a previously unrecognized environmental threat from a family of compounds found in firefighting foam known as perfluorooctanesulfonic acid (PFOS). A synthesis study to provide necessary education on the subject is proposed. It is suggested that it summarize the history of activities at airports – including those involving historic military operations – which have contributed to widespread PFOS contamination. The study will describe potential sources of PFOS, past airport practices leading to contamination, regulatory interest, and federal programs (such as those under the U.S. Department of Defense and Air National Guard) available to help airports deal with legacy sites. Deliverables would include a survey of airports currently dealing with these emerging contaminants and the steps they've taken to address the issue, as well as detailed case study examples such as the recent drinking water reservoir contamination occurring adjacent to Stewart International Airport. Airports will also benefit from an update on varying regulatory standards, including clean-up standards, health advisories, and safe drinking water limits at state and federal levels. The synthesis study would also look at the state of current treatment options. This information will assist airport management in assessing their potential risks and, if appropriate, developing strategies to identify and manage PFOS contamination on their properties.