Nearly one in every eight community water systems in Illinois were found to have PFAS detections in drinking water. The Illinois Environmental Protection Agency (EPA) recently announced the completion of an 18-month statewide sample collection study of PFAS in drinking water.

The study collected drinking water from over 1,000 community water systems (CWS). According to the Illinois EPA, 126 of the 1,107 CWSs sampled had confirmed PFAS detections. The drinking water samples were analyzed for 18 PFAS compounds as part of the investigation with PFOA and/or PFOS detected in 120 of the CWSs. The Illinois EPA reported that 68 of the CWSs with confirmed detections of PFAS were at levels below current health advisory levels. Two locations had detectable concentrations of PFAS that exceeded the U.S. EPA’s Lifetime Health Advisory levels. As a result, those sources were taken out of services.

In addition, the Illinois EPA issued health advisories for six PFAS compounds. The Illinois EPA issues health advisories when there is a detection of a chemical substance that is harmful to human health for which no numeric groundwater standards exists, after resampling confirms the presence in a community water supply well. The six PFAS compounds covered in the health advisory issuance include:

• Perfluorononanoic Acid (PFNA)

• Perfluorooctanesulfonic Acid (PFOS)

• Perfluorobutanesulfonic Acid (PFBS)

• Perfluorohexanesulfonic Acid (PFHxS)

• Perfluorohexanoic Acid (PFHxA)

• Perfluorooctanoic Acid (PFOA)

The state is planing to use the data gathered from the statewide PFAS investigation to help guide the development of future Maximum Contaminant Level (MCL) drinking water quality standards for PFAS.

Merit Laboratories is a leading national PFAS environmental laboratory, analyzing drinking water, soil, wastewater, groundwater, and other sample matrices, including biosolids and sludge. Analytical methods performed by Merit for PFAS include drinking water by EPA 533, EPA 537.1, and EPA 537 rev. 1.1, biosolids by ASTM D7968-17 with Isotopic Dilution, and soil, wastewater, groundwater, and surface water by ASTM D7979-19 with Isotopic Dilution and ASTM D7968-17.