By Mike Ekberg, manager of water resource monitoring and analysis
You've probably heard about PFAS, but what are they and why are they such a hot topic today?
Amazing chemicals
PFAS or per- and polyflouroalkyl substances are a group of chemicals developed in the 1940s that can repel water, dirt, and grease; tolerate high temperatures; make fabrics stain resistant; and can be used to extinguish fires. They are nearly indestructible and last for a really long time. According to the U.S. Food and Drug Administration, there are nearly 5,000 PFAS compounds in existence today.
Widely used in consumer products
PFAS are widely used in consumer products such as cookware, pizza boxes and stain repellants. The properties of PFAS make them well suited for the creation of nonstick cookware surfaces, water resistant fabrics, stain resistant carpets, and for use in some firefighting foams. These products are popular with consumers but the PFAS chemicals used in their production are bad for the environment.
Credit: Grand Valley State University
PFAS are bad news for the environment
Unfortunately, some of the same properties that make PFAS valuable in manufacturing, make them bad news for clean air, soil and water. The chemical bonds that hold PFAS molecules together make them highly resistant to breaking down in the natural environment. Once they get into soil and water, they persist for very long periods of time. Because PFAS are so persistent, they can buildup (bioaccumulate) in fish and wildlife. They can also accumulate in the blood and serum of people. Studies have shown that low levels of PFAS are commonly present in municipal wastewater sludge and effluent as well in many rivers and streams where treated or untreated human sewage is discharged. The issue of PFAS in the environment is not going to go away anytime soon.
Widespread exposure to PFAS in the U.S. population
Humans can be exposed to PFAS by consuming PFAS-contaminated food and water or by using products that contain PFAS.
Studies have shown widespread exposure of PFAS in humans. Yet, no one knows for sure the effects on human health, according to the Centers for Disease Control and Prevention.
Human health effects uncertain
Studies of laboratory animals given large doses of PFAS have found that some PFAS may affect growth and development, reproduction, thyroid function, the immune system, and injure the liver. Epidemiologic studies have examined a number of health effects and associated exposure to some PFAS compounds with the following:
More information for private well owners read this fact sheet from the National Groundwater Association.
PFAS what's next?
Science is working to better understand how PFAS interacts with the human body and what levels of exposure are safe. Meanwhile industry is phasing out certain PFAS chemicals and replacing them with others. Whether these new PFAS compounds are safer is unknown.
A lack of coherent policies and standards for PFAS in drinking water at the federal level has, in many cases, led to state regulatory agencies adopting their own standards. This has led to a hodgepodge of different drinking water standards for various PFAS chemicals across the country.
Public water systems with PFAS in their source water find themselves in the unenviable position of having to make decisions without federal guidance as to which standards they should apply and what treatment options are most cost effective and ensure consumer safety. The way forward on this issue remains a work in progress.
Most manufactured chemicals we use end up in the environment
Perhaps the most striking point in dealing with the issue of PFAS in the environment is these compounds are a reminder to us all that most manufactured chemicals we use as consumers end up in the natural environment in one way or another.
Our consumer-driven society creates strong incentives to create new chemical compounds in manufacturing and industry each year. Yet, our knowledge of the ultimate fate of these compounds and their potential impacts on human health and the environment is often sorely lacking.
In Part II, I'll take a closer look at the issue of PFAS in source waters for public drinking water systems and how this issue is being addressed at the national, state, and local levels.
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:
In PFAS Part III we will look at strategies for dealing with PFAS.
References
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.
In Part I, we looked at what per- and polyfluorinated alkyl substances, or PFAS, are and why you should care. In Part II, we looked at their presence in local drinking water. In this final post, we look at the strategies for dealing with PFAS.
Per- and polyfluorinated alkyl substances or PFAS are a group of manufactured chemicals widely used in consumer products such as cookware, paper wrappers for fast food, 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.
A lack of a cohesive nationwide approach for determining appropriate PFAS levels and actions has resulted in a wide range of state standards for different PFAS compounds. This adds to the confusion for consumers trying to determine how much PFAS in their drinking water is safe.
Three strategies for dealing with emerging contaminants
It's likely that chemicals, such as PFAS, originating from consumer products will continue to be detected in natural waters as well as treated drinking water. It's also likely that as consumers of public drinking water, we will continue to prefer that these types of chemicals not be present in our drinking water. With that in mind, here are three strategies that could help.
Credit: ept.ca/features/environmental-compliance-new-tsca/
1. Study chemicals in the marketplace and replace toxic substances with less toxic alternatives
It's estimated that approximately 2,000 new chemicals are introduced into the U.S. market each year. Few of these chemicals are evaluated for their toxicity and potential environmental impacts in a timely manner.
The Toxic Substances Control Act (TSCA) requires USEPA to evaluate new chemicals for safety, but historically, the agency did not have the necessary authority or resources to keep up with this task.
Congress recognized these deficiencies and, in 2016, it passed the Frank R. Lautenberg Chemical Safety for the 21st Century Act. The act made some important improvements to the process for ensuring safety of chemicals in the marketplace.
Key provisions of the act:
The act, however, only required USEPA to begin risk evaluations on 20 chemicals within the first three–and-a-half years of its implementation. Twenty is a very small number when compared to the number of new chemicals entering the market each year. If we can reduce or prevent chemicals that have a high potential of impacting water quality from entering the marketplace, we will have done our water resources a great service.
2. Source water protection is more important than ever
All too often decisions about how to develop land over sensitive aquifers and in close proximity to municipal wellfields are made without appropriate consideration about how the development and activities taking place on that development could impact water quality.
As consumers of public drinking water, we expect that our local governments and public water utilities engage in vigorous efforts to protect their supply of water. This means that economic development plans and activities must align with protection of our source of drinking water.
This alignment implies that some areas over sensitive water resources are not suitable for certain types of development that could pollute or threaten good water quality. A well thought out and proactive source water protection plan is the key to making this happen.
3. Investment in advanced water treatment may be needed
Public expectations often drive investment in new technologies. As new analytical methods lower thresholds for detecting contaminants, water utilities and regulatory agencies will have to deal with the discovery of new chemicals in water. While the concentrations may be extremely small, community members will most likely feel safer if these chemicals are not found in their drinking water.
Water utilities may be faced with the decision to provide advanced water treatment, such as membrane filtration and granular activated carbon filtration, but this level of treatment can be expensive and could raise water rates.
MCD Helping our region to be water resilient
The Miami Conservancy District is committed to helping our region successfully respond to the water challenges that chemicals such as PFAS present to the water resiliency of our communities.
At the request of Congressman Mike Turner, MCD and a group of community and business leaders retained a consultant to assess the City of Dayton's public water system and all interconnected utilities.
MCD is also working with the United States Geological Survey to evaluate the occurrence of PFAS in groundwater outside of the Dayton metro area. These efforts will help our region protect water for now and into the future.
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