Introduction to PFAS
Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemical compounds used in myriad manufacturing processes and are commonly found in consumer and industrial goods such as anti-stick coatings, water repellents, and fire suppressants. PFAS chemicals makeup render this family of compounds highly useful in everyday products but also makes them persistent in the environment when released.
PFAS includes thousands of compounds, with the following three being most notable – perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and GenX (trade name for a technology). PFOA and PFOS have been produced since the late 1940s, whereas commercial development of GenX started in 2009 as a replacement for PFOA. In the PFAS family, PFOA and PFOS are the most studied compared to other chemicals in the same group. Human exposure to PFOS / PFOA is thought to lead to adverse health effects such as cancer, thyroid hormone disruption, liver and kidney disease, etc. However, long-term human health effects are not well understood and are currently being investigated. State and federal regulatory agencies are developing regulatory strategies to address PFAS in the environment.
Remediation strategies to remove PFAS from the environment and reduce human exposure is challenging because of the persistent nature of these compounds. Drinking water is currently the primary media of concern for PFAS contamination, however, surface water, groundwater, air, landfill leachate, and wastewater treatment plants are also being scrutinized.
What This Means for the Affected Facility
Whether you’re a manufacturer, water or wastewater treatment plant operator, solid waste manager, or site developer, PFAS will increasingly impact your regulatory compliance and therefore your bottom line. It’s difficult to accurately sample and measure PFAS above background concentrations because these compounds are present in everyday products and packaging.
Experienced professionals should be used to collecting samples of known or potentially contaminated media, limiting ambient- and cross-contamination. An accredited and experienced laboratory should be used to completing the sample analyses to provide precise, accurate, and defensible results.
PFAS Sources and Environmental Transport
PFAS are generally used to manufacture fluoropolymer coatings that resist heat, oil, stains, grease, and water. Products typically include clothing, furniture, non-stick cooking surfaces, and food packaging materials. It was common in the past for these manufacturing facilities to discharge waste PFAS directly to the environment because the compounds were not formally regulated. Another major source of PFAS is Aqueous Film-Forming Foam (AFFF) primarily used as a flammable liquid fire suppressant and commonly found in groundwater near former fires and firefighting training sites.
PFAS compounds are commonly transported by atmospheric deposition to soil and surface water, direct releases to soil, migration from soil to groundwater, wastewater and groundwater discharges to surface water, and solid waste landfill leachate. At various landfill sites, leachate contaminated with PFAS are typically sent to wastewater treatment plants for final management. These plants are not typically equipped with adequate PFAS treatment technology and eventually, PFAS in treated wastewater may be discharged to receiving water bodies.
Current and Anticipated PFAS Regulation
PFAS compounds are not currently regulated in drinking water or other media by the federal government, although the US Environmental Protection Agency established 70 parts per trillion (ppt) Drinking Water Health Advisory Level (HAL) for both individual and combined concentrations of specific PFAS compounds, PFOS and PFOA. Michigan set drinking water standards lower than the EPA’s 70 ppt limit, for four PFAS compounds effective August 1, 2020. Ever-more stringent regulation of PFAS in the environment (groundwater, surface water, air) is anticipated.
PFAS Treatment Technologies
The PFAS carbon-fluorine bonds make these compounds persistent and difficult to degrade and remove from the environment. As a result, PFAS are often referred to as a “forever chemical” due to their persistent nature. Traditional treatment technologies for removing PFAS from drinking water include Granular Activated Carbon filtration, Ion Exchange, and Membrane Filtration using Nanofiltration or Reverse Osmosis. Treatment technologies have unique advantages and disadvantages. PFAS is broadly classified as either short-chain or long-chain compounds. A complete and accurate characterization of PFAS compounds to be treated is important for implementing the most efficient and robust treatment design.
New treatment technologies are also being investigated to determine efficiency and efficacy for removing PFAS from drinking water. Examples include in situ remediation, polymer coated sand, biochar, nanofiltration and more.
PFAS Destruction Technology
It is important to prevent PFAS filtrate re-entry to the environment once removed from water systems. Currently, researchers are investigating methods for the destruction of PFAS compounds leading to complete mineralization of the carbon and fluorine bonds.
Check back for a future blog which further details treatment and destruction technologies.
How to Navigate PFAS Assessment and Remediation
At Draper Aden Associates, we can accurately assess the nature and extent of PFAS contamination, recommend the most effective and economically feasible treatment solution to remove PFAS compounds from the affected media, design and implement treatment, assist with regulatory tasks to maintain compliance following safe drinking water standards, and provide construction administration and operations assistance for the PFAS treatment system.
This blog is the first in a series discussing PFAS and its effect on the environment. Check back soon for an update to the regulatory situation for PFAS and other related blogs.