Fairfax Water and PFAS

In early March the Environmental Working Group (EWG) released the results of a a new analysis, they commissioned of tap water samples taken from various location throughout the Northern Virginia region. The EWG reported that they detected total PFAS in 19 samples of tap water ranged from about 6 parts per trillion, or ppt, in a state park in Fairfax County, to about 62 ppt in a public park in Prince William County. In 2019 the EWG had reported that the results from the sampling conducted as part of the EPA’s Unregulated Contaminant Monitoring Rule 3 from 2013 to 2015.  All results in Fairfax were non-detect, meaning that all results were below the detection limit of the test used. The analysis was conducted using EPA Method 537. In the Prince William County Service Authority Eastern service area was found to have 12 ppt of PFAS in 2014. This year’s findings were more wide spread and in some cases at a higher level.

Fairfax Water responded to the new release from EWG by stating that when they tested in 2013 to 2015 that no perfluoroalkyl substances (PFAS) were detected in Fairfax Water’s service area, and pointing out that:  “There is currently no established federal water quality regulation for any type of PFAS.  In May of 2016, The Environmental Protection Agency (EPA) established the health advisory levels at 70 parts per trillion (ppt) for Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic acid (PFOS).  Both chemicals are types of PFAS.” In February 2020 and in February 2021 the EPA announced its intention to regulate PFOA and PFOS under the safe drinking water act. No limit was identified. In late 2020 the European Union (EU) issued a directive  setting a limit value of 500 ppt for total PFAS concentration in drinking water.   

Fairfax Water says “There are no treatment processesavailable for drinking water utilities that would not significantly increase water rates for customers. Nor would such treatments produce a demonstrated health benefit. “ It appears that they are going to see what concentration the EPA intends to regulate PFOS and PFOA for drinking water. Changing the water treatment chain at the Corbalis and Griffith water treatment plants would be necessary to treat the source water to remove PFAS. This would "significantly" increase the cost of water for all the residents of Fairfax and Prince William Counties. 

In May of 2016, The Environmental Protection Agency (EPA) established the health advisory levels at 70 parts per trillion (ppt) for Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic acid (PFOS). All the samples taken by EWG are below that level.  I do not know at what level the EPA or Virginia intends to regulate PFOS and PFOA at. Several states have set significantly lower levels for some PFAS contamination. Studies indicate that high concentrations of PFOA and PFOS can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. Both chemicals have caused tumors in animal studies. The most consistent findings from human studies are increased cholesterol levels among exposed populations, with more limited findings related to cancer, thyroid hormone effects, other reproductive and developmental impacts in humans, infant birth weights and adverse effects on the immune system. The EWG is pushing for a federal limit if 1 ppt.

The source of PFAS contamination in the latest samples is not known. The level of PFAS in a sample of tap water is largely determined by the source of the water supply. However, the EWG speculates based on the location of the samples that the Occoquan Reservoir and/or the Occoquan watershed in Prince William, may be the source of the contamination. In February 2020, a malfunction released a large spill of PFAS-based firefighting foam from a hangar at Manassas Regional Airport, in the Occoquan River basin. It is not known whether the spill contaminated water supplies, but it is possible and would explain the difference in the sampling results reported in 2014 and 2020.

PFAS are synthetic fluorinated organic chemicals. Manufacturers have produced PFAS for a variety of industries and products, including surface treatments for soil/stain/water resistance; surface treatments of textiles; paper; metals; and for specialized applications, such as fire suppression for hydrocarbon fires, and have been widely used on military bases.

PFAS are resistant to metabolic and environmental degradation, are highly persistent in the environment and can bioaccumulate in humans; and therefore are often called “forever chemicals.” PFAS include a large number of important chemicals that can be used in some food packaging and can make things grease- and stain-resistant. They were used in firefighting foams and in a wide range of manufacturing practices. The result is that according to the CDC more than 95% of the U.S. population has measurable levels of PFOA and PFOS in their blood; and babies are born with PFOA in their blood.

Drinking water can be a source of exposure in communities where these chemicals have contaminated water supplies. Such contamination is typically associated with a specific facility, for example: an industrial facility where PFAS were produced or used to manufacture other products, or locations where firefighting foam was used such as oil refineries, airfields or other training facilities for firefighters.

Activated carbon or commonly granulated activated carbon (GAC) has been shown to effectively remove PFOS and PFAS from drinking water. The EPA says, “GAC can be 100 % effective for a period of time, depending onthe type of carbon used, the depth of the bed of carbon, flow rate of thewater, the specific PFAS you need to remove, temperature, and the degree andtype of organic matter as well as other contaminants, or constituents, in thewater.” Activated carbon treatment an inexpensive and readily available point of use treatment. “High-pressure membranes, such as nanofiltrationor reverse osmosis, have been extremely effective at removing PFAS. Reverse osmosis membranes are tighter than nanofiltrationmembranes.  Research shows that these types of membranes aretypically more than 90 percent effective at removing a wide range of PFAS,including shorter chain PFAS.”