In Part I, we looked at what per- and polyfluorinated alkyl substances, or PFAS, are and why you should care. In Part II, we look at the impact to our drinking water.
Per- and polyfluorinated alkyl substances or PFAS are a group of manufactured chemicals widely used in consumer products such as cookware, pizza boxes, stain repellants, and fire-fighting foams. These chemicals gained widespread attention nationally as well as locally when they began to be detected in the drinking water of some public water systems.
New analytical methods open a Pandora’s Box
Over the past couple of decades, new analytical techniques have emerged that make it possible to detect contaminants in water at concentrations as low as parts per trillion. The emergence of these new analytical methods led to the discovery of previously undetectable contaminants in natural waters as well as treated drinking water.
Because of these new capabilities, the scientific community began to discover many of the chemicals that are used in common household consumer products, as well as in pharmaceuticals, were also present at low concentrations in many rivers, streams, and aquifers all over the world. Some of these chemicals were also detected in treated drinking water.
PFAS was one of the groups of these chemicals detected in both natural waters and treated drinking water. The discovery of previously undetectable contaminants in drinking water has prompted questions by public water system operators nationwide. How do you communicate health risks for a contaminant when there is no regulated drinking water standard with which to compare? Does the public expect that none of these compounds will be present in drinking water? How does everyday exposure to these compounds from consumer products compare to exposure from drinking water?
PFAS present in the waters of the Miami Valley
PFAS is here, too. Rivers and streams in the Miami Valley likely contain low levels of some PFAS compounds. Studies have shown that most municipal wastewater effluent contains low levels of PFAS. (Margot, J., Ross, L., Barry, D.A., and Holliger, C., 2015)
A study conducted by MCD in 2010 and 2011 found low levels of the PFAS compound PFOS present in 22 out of 31 river, stream, and aquifer sampling sites. The same study also found PFOS in two out of two wastewater treatment plant outfalls sampled.
More recently, PFAS compounds were detected in the treated drinking water at Wright Patterson Air Force Base (WPAFB) and at the City of Dayton. According to the Dayton Daily News (March 11, 2020), the PFAS is thought to have originated from the use of foams during fire-fighting training activities. PFAS from the foams may have leached into the underlying aquifer and traveled to nearby water supply wells. PFAS concentrations at WPAFB were high enough that a granular activated carbon filtration system was required to reduce concentrations to acceptable levels. Meanwhile the levels of PFAS in the Dayton public water system have remained low enough that additional treatment has not been necessary.
Federal and state regulatory agencies struggle to coordinate PFAS response
Determining consistent health guidelines for levels of PFAS in drinking water has been a struggle for federal and state regulatory agencies. The United States Environmental Protection Agency (USEPA) published its PFAS action plan in February 2019. Under the plan, USEPA committed to developing maximum contaminant levels for two commonly detected PFAS compounds, PFOA and PFOS. The agency will also designate PFOA and PFOS as hazardous substances and begin a national monitoring program to examine the occurrence of PFAS compounds in drinking water.
Prior to the federal PFAS action plan, some states elected to set their own drinking water standards for PFAS as public pressure to do something about these contaminants mounted. Ohio EPA adopted the USEPA health advisory level of 70 parts per trillion. Ohio also developed a PFAS action plan for drinking water in December 2019. The objectives in include:
- Gather and provide sampling data from specific types of public water systems to determine if PFAS is present in raw and finished drinking water.
- Assist private water system owners with guidelines and resources to identify and respond to potential PFAS contamination.
- Establish action levels for drinking water systems in Ohio to aid in appropriately responding to PFAS contamination for the protection of public health.
More information on the Ohio PFAS action plan for drinking water is available at https://epa.ohio.gov/pfas.
In PFAS Part III we’ll look at strategies for dealing with PFAS.
Margot, J., Ross, L., Barry, D.A., and Holliger, C., 2015. A review of the fate of
micropollutants in wastewater treatment plants. 2015 Wiley Periodicals, Inc.,
WIREs Water 2015. doi: 10.1002/wat2.1090.
Ismail Turay, Jr., (2020), ‘Ohio EPA to begin testing for ‘forever’ chemicals in drinking water,’ Dayton Daily News, 11 March.