A Sustainable Cleanup Solution for Preventing PFAS in Drinking Water
Eleven states in the U.S. have enacted laws or regulations that ban “intentionally added” PFAS (per and polyfluoroalkyl substances) in food wrappers and containers to date. These states include California, Colorado, Connecticut, Hawaii, Maine, Maryland, Minnesota, New York, Rhode Island, Vermont, and Washington. The California and New York bans are already in effect starting January 1, 2023. Other state PFAS packaging bans are also planned for later this year.
The new state laws and regulations come at a time when many people are becoming aware of the health risks frofxposure to PFAS. These chemicals have been linked to an increased risk of wide-ranging health ailments, including hypertension, thyroid malfunction, liver disease, immunodeficiencies, and cancer. And reports emerge almost daily connecting PFAS with newly identified health problems.
PFAS chemicals used in food wrappers can make their way into thod products and impact human health. According to one study, regular consumers of microwave popcorn had higher concentrations of PFAS in their blood serum. Additionally, it was reported consumers who order fewer takeout meals and eat at home more were found to have lower PFAS levels.
In time, these new regulations restricting PFAS in food packaging will help reduce the daily ingestion of PFAS. However, millions of Americans are still exposed to a greater risk: the water from their faucets. Even though we’re advised to drink eight glasses of it a daily, this water may contain alarming levels of PFAS.
PFAS Contaminated Drinking Water: A Pervasive, often Undetectable Problem
According to the Environmental Working Group, as many as 200 million Americans may be drinking water contaminated with “forever chemicals”. This number was based on a detection level greater than 1 part per trillion, which is undeniably tiny, but still many times more than the respective 0.004 ppt and 0.02 ppt Health Advisory (HA) levels set by the U.S. EPA for PFOA (perfluorooctanoic acid) and PFOS (perfluoro sulfonic acid), two of the most prevalent PFAS compounds.
Given the apparent health risks, the agency has proposed to formally regulate PFOA and PFOS as hazardous substances under the Safe Drinking Water Act before the end of 2023. Considering the low HAs, it is likely that almost all of us are drinking unsafe levels of PFAS, even if we can’t detect them.
Sources of PFAS Contamination in Water
There are numerous sources of PFAS contamination of groundwater, however, attention was initially drawn to the repeated use of Aqueous Film-Forming Foams (AFFF) at airports and military bases worldwide. These AFFF releases have been linked to some of the most serious contamination problems discovered thus far. This is in part due to the Department of Defense’s mandatory PFAS testing conducted at their facilities.
Recently, the focus on PFAS has shifted to the many industrial sources contributing to the issue. These sources include processes enhancing the stain and water repellence or durability of packaging materials. PFAS chemicals leaked from facilities that either manufacture or otherwise use fluorinated coatings for packaging can leach through the soil to contaminate the groundwater. In groundwater, PFAS form ‘plumes’ can travel for miles and reach wells that pump water for human consumption. It is estimated that almost half of the U.S.’s drinking water is sourced from groundwater.
There are other ways that PFAS in packaging materials can impact groundwater. For instance, food packaging in landfills has also been identified as a major source of PFAS in landfill leachate, which then contaminates the surrounding groundwater. Additionally, the U.S. EPA has sued a plastics company over allegations that PFAS are created during a fluorination process used to make plastic containers more resistant. These PFAS chemicals can leak into the products they contain (e.g., insecticides) and end up in the groundwater when they are applied.
Removing PFAS from Drinking Water is Inefficient and Costly
Once a drinking water well becomes impacted by PFAS, many affected communities employ costly approaches which remove the chemicals by filtering the effluent stream of a pumping well aboveground with sorbent media. Known in the groundwater remediation industry as pump and treat (P&T), this method has been used in water treatment plants for many years, however, its application to PFAS is new. It is also highly problematic and very expensive.
For larger community water supplies, P&T involves large aboveground tanks or in-ground beds filled with granular activated carbon or ion exchange resins that filter the chemicals out of the water. These systems, like the recent six-million-gallons-per-day system installed by the City of Stuart, Florida, can cost tens of millions of dollars to implement, and millions more to operate annually for many years to come.
Water is heavy and requires a lot of work to move it, which means the pump & treat (P&T) method is an energy-hogging approach with a massive carbon footprint. A typical P&T system preventing PFAS from contaminating drinking water can generate annual carbon dioxide (CO2) emissions equivalent to a fleet of gas-powered automobiles. In most cases, these P&T systems are designed to work around the clock, year after year, for decades.
Additionally, these P&T systems generate tons of PFAS-laden waste materials that are either thrown into landfills or incinerated. Due to their near-indestructible and mercurial nature, both disposal methods risk releasing the chemicals back into the environment. PFAS are found in groundwater at most landfills that have tested for them, and the U.S. EPA has not endorsed any incineration methods as safe and effective.
A Sensible, Cost-Effective and Sustainable Solution Prevents PFAS from Impacting Drinking Water Using Colloidal Activated Carbon In-Ground Filtration
Considering the mounting evidence of adverse health effects due to exposure, further PFAS impacts to drinking water should be prevented, wherever possible. With this aim, material scientists at REGENESIS developed a novel colloidal activated carbon technology (CAC, a.k.a., PlumeStop®) that transforms the sand, gravel, or rock materials that groundwater moves through (i.e., the aquifer matrix) into an in-ground purifying filter for PFAS.
Powered by nature, the process relies on flowing groundwater to move PFAS into CAC-treated zones, where the chemicals are filtered out. These CAC filter zones are created by directly injecting CAC across the groundwater flow path between a PFAS source zone (e.g., an airport fire training area) and a ‘downstream’ drinking water well or surface water body.
CAC’s net-zero-emissions manufacturing process involves milling activated charcoal into red-blood-cell-sized particles and treating it with a food-grade, anti-clumping agent to create a colloid. This patented material innovation allows CAC to move through and ‘paint’ the aquifer materials with microscopic carbon. As groundwater moves from higher to lower elevations across a CAC filter zone, PFAS attach to the carbon adhered to the aquifer matrix and are removed from the water. By removing PFAS from groundwater, the exposure risk to potential receptors is eliminated, usually for decades following the installation of a single CAC filter zone.
CAC treatments consume little to no energy and generate no emissions or PFAS waste. The approach is also substantially more economical. Based on a recent study showing 57,000 PFAS-contaminated facilities may exist in the U.S. alone, millions of tons of CO2 emissions may be eliminated, and potentially billions of dollars saved, using in-ground CAC treatments to filter PFAS out of groundwater and protect our drinking water resources from these harmful chemicals.
Closing
Banning PFAS from food wrappers and other types of packaging materials is one of the obvious solutions states are requiring to reduce daily exposure to the ‘forever chemicals’. Unfortunately, many of these PFAS chemicals have already been released into the environment, threatening to contaminate drinking water sources and impact public health. To mitigate these unseen risks, effective, practical, and sustainable CAC in-ground filtration treatments are deployed at over 30 sites worldwide, with hundreds more sites in the planning stages.
Author Info:
Ryan Moore (rmoore@regenesis.com), CHMM, is PFAS Program Manager at REGENESIS®, focused on collaborating with environmental professionals and the industry at large in communicating effective, proven approaches to manage sites where PFAS contaminants exceed regulatory standards. Ryan has managed the use of PlumeStop®, Colloidal Activated Carbon™, available exclusively through REGENESIS, to treat PFAS and other organic pollutants at hundreds of sites globally.