PFAS Test Results

Understanding Our Per- and Polyfluoroalkyl Substances (PFAS) Test Results

The tables on this page show the results of our PFAS compliance testing. These results are compared against the maximum contaminant levels (MCLs) for these six key compounds regulated by the U.S. Environmental Protection Agency (EPA):

• PFOA: Perfluorooctanoic acid
• PFOS: Perfluorooctanesulfonic acid
• PFHxS: Perfluorohexanesulfonic acid
• HFPO-DA (also called GenX): Hexafluoropropylene oxide dimer acid
• PFNA: Perfluorononanoic acid
• PFBS: Perfluorobutane sulfonate

For transparency, WSSC Water reports both the individual sample results and the running annual average.

Individual results tables show the data received directly from the laboratory.

Running annual average tables show the average amount measured over the most recent four quarters.

In accordance with EPA rules, any test result below the practical quantitation limit (PQL) is treated as zero when calculating the running annual average. The PQL, as defined by EPA, is the lowest level a laboratory can measure with reliable accuracy. Therefore, if a PFAS chemical is detected below the PQL, it is counted as zero in the average—even though a trace amount may still be present.

Test Results

Select from the following items to access the test results for our water filtration plants.