Recently, drinking water quality across the United States has drawn attention from the media. The issue of the day is localized contamination at the minute levels of per- and polyfluoroalkyl substances, better known as (PFAS). This PFAS group has over 4000 manmade chemicals and is used by industries around the world. These chemicals are in nonstick coatings, fast-food wrappers, firefighting compounds, polishes, stain repellants, waxes, and many other products. Some other recently uncovered PFAS chemicals we hear of now include perfluorooctanoic acid (PFOA), perflurooctane sulfonate (PFOS), and GenX chemicals, like perfluorobutane sulfonic acid (PFBS).
The problem with all of these substances is that the chemical bonds are so strong they do not break down over time. This means that we absorb them through our food and other products. The human body can hold on to these compounds, which don’t change. At some point, with prolonged exposure, high levels of PFAS may adversely affect human health, according to researchers. Another problem is they are measured down to parts per trillion (ppt). Wow—ppt! That is minute for sure.
The U.S. Environmental Protection Agency (EPA) has established nonbinding drinking water health advisories for PFOA and PFOS at 70 ppt in 2016. Research from EPA shows that PFAS compounds can cause reproductive, developmental, liver and kidney, and immunological effects in laboratory animals. In studies, both chemicals have caused tumors in animals. The most consistent findings from human epidemiology studies are increased cholesterol levels among exposed populations. From this, EPA has now regulated that manufacturers need to remove PFAS compounds from further usage. There are so many PFAS compounds that the risks have not been fully identified by researchers. An action plan is being developed for limiting and identifying risks.
EPA Action Plan
The EPA’s February 2019 action plan describes approaches to identifying and understanding PFAS contamination, preventing future contamination, and effectively communicating with the public about PFAS. This action plan describes four steps for PFAS management:
- Evaluate the need for a maximum contaminant level (MCL) for PFAS, PFOA, and PFOS.
- Begin the necessary steps to propose designating PFOA and PFOS as “hazardous substances.”
- Develop groundwater cleanup recommendations for PFOA and PFOS at contaminated sites.
- Develop toxicity values for GenX chemicals and PFBS.
The action plan also identifies more short- and long-term actions to address PFAS issues. Short-term actions include:
- Developing new analytical methods and tools for understanding and managing PFAS risk.
- Promulgating Significant New Use Rules (SNURs) that require EPA notification before chemicals are used in new ways that may create human health and ecological concerns.
- Using enforcement actions to help manage PFAS risk.
Water Treatment Methods for PFAS
As operators, we must understand this action plan impact to our water systems. Also, we must understand the health risks and water treatment methods used to remove PFAS. Public outreach may be necessary if there are local concerns, so we must be ready for our customers to ask questions relating to these PFAS compounds. Being familiar with the treatment may help you plan for a response, if needed. Operators should plan for future impacts to address this in budgeting and capital improvement planning.
These advanced treatment methods are the most effective removal technologies today:
- Granular Activated Carbon (GAC)– Chemicals like PFAS are absorbed in the small pieces of carbon as the water passes through.
- Powdered Activated Carbon (PAC)– The carbon is powdered and is added to the water. The chemicals are then absorbed into the powdered carbon as the water passes through and the carbon is filtered out in the process for removal.
- Ion Exchange Resins–Small beads (called resins) are made of hydrocarbons that work like magnets. The PFAS chemicals are exchanged with beads compounds and are removed as the water passes through.
- Nanofiltration and Reverse Osmosis – Filtration process where water is pushed through a membrane with small pores. The membrane acts like a wall that can stop chemicals and particles from passing into drinking water by removing them.
Don’t overlook the byproducts of these processes; they should also be understood for concentrated levels of PFAS for proper disposal on spent carbons, resins, and reject water. A renewable carbon or resin source should be used.
Some Other Concerns
The PFAS action plan needs to be monitored. The first goal in this process is the EPA rulemaking that sets drinking water standard MCLs. The concern here is having the MCL as one group for PFAS, instead of each of the multiple chemicals. This would be too large of a group to effectively regulate and manage for compliance.
Liability is also an issue here for PFAS clean-up and any financial responsibility, which should belong to the PFAS producers. It would not be fair to hold community and drinking water systems and wastewater treatment facilities liable for PFAS contamination caused by a company’s products.
This could, however, have unintended consequences for utilities. The PFAS in source water may be retained in solids removed through treatment and will be found in media used to remove PFAS, thus complicating disposal. A hazardous substance designation could also result in water and wastewater treatment systems substantially increasing the cost of disposing of these materials, which would also increase the cost of the water supply to our communities. Wastewater effluent could also be an issue with minute trace amounts and the implications for removal.
The third Unregulated Contaminate Monitoring Rule (UCMR 3) introduced us to these perfluoronated compounds by EPA. Six compounds were in the communities sampling plan for UCMR 3, which may be the starting point for your actions now. Resampling may be necessary, if there is a localized concern. From what I’ve read, there are only a handful of contaminated sites in Florida, mostly around airbases, airports, or older industrial sites.
More monitoring is coming, with UCMR 5 on the horizon, and it’s in development right now by federal government agencies. They will be drilling down on information on PFAS chemicals for their databases, rulemaking, and public notifications. This looks to happen in 2023—or maybe sooner.
Clearly, now is the time for you to further your education and your tool box! The knowledge for water operations of advanced treatment methods is critical. Networking with fellow operators on these PFAS issues for clarification on this can only help. Attending your FWPCOA regional meetings is a good place to do that.
So, having a best friend forever is great, but having these chemicals in your source water is not.
Remember to keep on learning—our profession and your community are depending on you!