PFAs in Drinking Water
Per- and polyfluoroalkyl substances, also known as PFAS, are a group of over 5,000 human made compounds. Used since the 1940s, PFAS compounds can be in a wide range of consumer and industrial products and processes. PFAS released to the air, soils, ground- or surface water can enter into nearby drinking water sources. To assess the presence of PFAS in state drinking water sources, the Maryland Department of the Environment (MDE) has initiated an assessment from 137 selected Community Water Systems.
These Community Water Systems were selected by the proximity, number, and type of potential sources of PFAS MDE mapped over 2,000 potential sources of PFAS in Maryland. The 2,000 potential sources include military installations, fire training areas, airports, landfills, manufacturing facilities, and wastewater treatment plants.
The purpose of this initial sampling effort is to assess the occurrence of PFAS in Maryland’s most vulnerable public drinking water sources and, when necessary, to take action to require monitoring or risk mitigation measures.
In Poolesville’s water system, elevated levels of PFOA or PFOS were detected in the water samples collected from Well 2 and Well 3. A Tier 2 Public Health Advisory Notice was mailed to every resident. While there are no national or state Maximum Contaminant Levels (MCLs) for PFAS in drinking water, the EPA released interim health advisories for PFOA and PFOS. For this reason, we have taken Wells 2 and 3 offline.
Drinking water health advisories provide information on contaminants that can cause human health effects and are known or anticipated to occur in drinking water. EPA's health advisories are non-enforceable and non-regulatory and provide technical information to states agencies and other public health officials on health effects, analytical methods, and treatment technologies associated with drinking water contamination. EPA’s lifetime health advisories identify levels to protect all people, including sensitive populations and life stages, from adverse health effects resulting from exposure throughout their lives to these PFAS in drinking water. The health advisory levels were calculated to offer a margin of protection against adverse health effects. EPA’s lifetime health advisories also take into account other potential sources of exposure to these PFAS beyond drinking water (for example, food, air, consumer products, etc.), which provides an additional layer of protection.
Poolesville will continue to conduct additional sampling and develop a plan for removing PFOA, PFOS and other PFAS in the drinking water.