In our OneWater environment, solving problems caused by per- and polyfluoroalkyl substances (PFAS) is perhaps the most challenging socio-economic issue facing the environmental and construction sector today—a daunting public health issue for clients and communities we must confront.
The durability of PFAS have led to their use in an array of applications—from industrial firefighting foam, solvents and water- and stain-resistant coatings to consumer nonstick cookware, grease-resistant paper and fast-food containers.
But as broad as PFAS’ use is, the size, complexity, risk and cost of the toxic problem they pose is much greater.
Decades of manufacture, use, storage and disposal of products that contain PFAS have released the chemicals into the environment—our drinking water, air, soil and food supply. Their resistance to heat, oxidation, reduction and other chemical and biological reactions has led to them deemed “forever chemicals.”
Monitoring and occurrence data indicate that PFAS have impacted drinking water supplies serving up to 200 million Americans, with studies showing they may linger for years in blood tissue and link to certain cancers, liver problems and children’s immune system suppression.
The U.S. Environmental Protection Agency has published evidence suggesting exposure to PFAS even at extremely low levels (parts per trillion or ppt) can lead to health problems in humans. In addition to banning manufacture and use of PFAS with known or suspected adverse health impact, EPA issued a health advisory level of 70 ppt for short-term exposure in drinking water for two particularly pervasive PFAS chemicals. It does not plan to issue a final rule for these substances until fall 2023.
A number of Eastern states and California, which are heavily impacted, have implemented stricter limits, more comprehensive monitoring and more aggressive treatment rules.
For many consumers and water utilities, waiting for regulations or reducing concentrations of PFAS to “safe” levels in the absence of more definitive health data is not good enough. They seek to get rid of PFAS from drinking water, and get rid of it now.
PFAS durability has made these "forever chemicals" a staple in everything from firefighting foam to microwave popcorn bags.
Credit: Massachusetts DEP
Working through COVID-19 and labor and supply chain challenges, the engineering and construction community must actively connect now to remedy the risks of PFAS and boost collaboration to find, test and deploy the most innovative and cost-effective approaches there are to provide safe drinking water.
Large and small U.S. projects are underway, some moving quickly through design and into construction using proven removal technologies such as adsorption with granular activated carbon, ion exchange and reverse osmosis membranes to treat PFAS to non-detectable levels. Each solution has required a unique rapid response, often expedited using alternative project delivery such as design-build, CMAR, CM/GC, EPCM and equipment and materials pre-purchase.
Overall, the lack of specific regulatory guidance has forced utilities to take a “hurry up and solve the best they can” approach to deliver PFAS removal solutions. With treatment technologies available, there is no need to wait.
But in some cases, such an approach can set aside the proven course of more thoughtful process planning, which can result in treatments that underestimate turbidity, corrosion control or other impacts. These pitfalls are avoidable when experienced water professionals are involved. When done right, feed water with hundreds of parts per trillion of PFAS can be treated to non-detect levels.
While treatment solutions are impressive in removing these stubborn chemicals, they alone cannot break the PFAS cycle. The substances still accumulate in spent granular activated carbon or ion exchange resins, and in reverse osmosis concentrate—leaving residual wastes to process and dispose of.
Research programs are developing ingenious solutions to concentrate and destroy PFAS without releasing harmful by-products. This is critical, since the industry must address end users’ needs with a comprehensive plan that eliminates the problem rather than just shifting it to another part of the environment.
The push to identify, develop and implement affordable destructive technologies that remove PFAS from the environment altogether is essential to the health of our communities, and a pursuit we must all support.
Alan LeBlanc, PE, is vice president and drinking water discipline leader of CDM Smith, based in Manchester, N.H. He can be reached at firstname.lastname@example.org