Reprint of USEPA Press Release dated today.
WASHINGTON (Dec. 19, 2019) — Today, the U.S. Environmental Protection Agency (EPA) took another key step in implementing the agency’s PFAS Action Plan by announcing a new validated method for testing per- and polyfluoroalkyl substances (PFAS) in drinking water. This new validated test method complements other actions the agency is taking under the Action Plan to help communities address PFAS nationwide.
“EPA’s important scientific advancement makes it possible for both government and private laboratories to effectively measure more PFAS chemicals in drinking water than ever before,” said EPA Administrator Andrew Wheeler. “We can now measure 29 chemicals, marking a critical step in implementing the agency’s PFAS Action Plan—the most comprehensive cross-agency plan ever to address an emerging chemical of concern.”
EPA’s new validated Method 533 focuses on “short chain” PFAS, those PFAS with carbon chain lengths of four to 12. Method 533 complements EPA Method 537.1 and can be used to test for 11 additional PFAS.
Method 533 accomplishes a key milestone in the EPA PFAS Action Plan by meeting the agency’s commitment to develop new validated methods to accurately test for additional PFAS in drinking water. Method 533 also incorporates an analytical technique called isotope dilution, which can minimize sample matrix interference and improve data quality.
PFAS are a class of synthetic fluorinated chemicals used in many industrial and consumer products, including defense‐related applications. They are persistent, found at low levels in the environment, and bio‐accumulate. Studies have shown these compounds being detected more often in surface water, sediments and/or bioaccumulated into fish tissue. Because of the greater affinity of longer chain per‐ and polyfluoroalkyl substances (PFASs) compounds for fish than other environmental matrices, certain compounds are often found in fish tissue, but not in the water or sediment. Table 1 shows average concentrations of PFOA and PFOS in landfill leachates around the world. The USEPA health advisory level is 70 ppt for PFOA and PFOS.
Table 1. Concentrations of PFAS compounds in Landfill Leachate around the world
Treatment Options for PFOS and PFOA
The removal of PFASs from drinking water has been the USEPA’s national priority. Recent discoveries of PFAS/PFOS in drinking water in multiple states in the US has heightened interest in these emerging contaminants. Federal, state, and local agencies are formulating regulatory limits that vary greatly. These limits seem to be centered on drinking water, but these developments are driving disposal of existing stores of chemicals containing PFAS/PFOS and environmental media contaminated with PFAS/PFOS
Treatment processes that can remove PFAS chemicals from drinking water may include high-pressure membrane systems such as RO, granular activated carbon (GAC), or ion exchange as shown in Figure 1. The more conventional water treatment technologies such as (e.g., aeration) are not typically effective.
Landfill Leachate RO Treatment Plant – New Hanover County, North Carolina
New Hanover County upgraded its leachate treatment system to meet stricter regulatory standards for surface water discharges, particularly standards relating to metals (arsenic) and ammonia. Sampling by NC DEQ showed the new RO plant is filtering out PFAS. Table 2 shows the results from February 2019.
Figure 2. New Hanover County Leachate and PFAS Treatment Plant
Table 2. Concentrations of PFAS compounds in Leachate at New Hanover County Landfill
|PFAS Constituent||Raw||Treated||Surface water|
|PFOA (ppt)||1,250||< 0.6||3.9|
|PFOS (ppt)||228||< 0.6||7.1|
Comparison of GAC Types for PFOA and PFOS Removal
Four different types of GAC, i.e., Re-agglomerated Bituminous, Lignite, Enhanced Coconut and Enhanced Coconut (Blend) were evaluated under identical operating conditions and influent water quality. Figure 4 shows results from these four GAC products for PFOA/PFOS removal vs time.
Figure 4. GAC Treatability study for removal of PFOA and PFOS
Re-agglomerated bituminous coal GAC (FILTRASORB) significantly outperformed: Lignite, Enhanced Coconut and Enhanced Coconut (Blend).
PFAS compounds are of concern because they do not break down in the environment, bioaccumulate in humans and biota, and may pose risks to human health
GAC, Synthetic adsorbent, and ion exchange resins are widely used for PFAS removal. Capacity and leakage of PFASs into the treated water varies depending on the specific PFASs, the type of adsorbent used.
PFAS removal may be influenced by pH, water temperature, contact time, Natural Organic Matter, and chlorine. For complete PFAS removal, a polishing may be required.
Disposal methods for PFAS waste streams include high-temperature incineration or landfilling. Landfilling is not favored since the PFAS load would increase, and many landfills will not accept PFAS waste.
About the Author: Dr. deSilva is SCS’s Director of Wastewater Treatment. He has 30 years of progressive experience in wastewater engineering, from concept through construction and start-up, and is an international leader in operations and maintenance, energy management, solids handling processes, construction management, and commissioning wastewater treatment plants (WWTP) around the world.
Perfluoroalkyl and polyfluoroalkyl substances collectively referred to as PFAS or “forever chemicals,” are being detected in water and many types of foods. Viraj deSilva of SCS Engineers provides an overview of sources, treatment processes used to remove them from wastewater, and government advisory limits in this recent article in World Water Magazine.
PFAS is extremely persistent in the environment and includes more than 4,500 synthetic chemicals, are organic compounds whose hydrogen atoms are replaced by fluorine. The bonds between fluorine and carbon are extremely strong and difficult to break.
The two main PFAS compound structures are perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). PFOA and PFOS are no longer manufactured or used in the US, but similar replacement chemicals (such as GenX) remain. Other countries still manufacture PFAS and many consumer products imported to the US from those countries still contain the compounds.
About 610 locations in 43 US states serving an estimated 19 million people have PFAS in the drinking water, according to the Environmental Working Group and the Social Science Environmental Health Research Institute at Northeastern University in Boston, Massachusetts, United States (US). See the full references in the article.
The current US Environmental Protection Agency (EPA) health advisory limit is 70 parts per trillion. However, as an advisory level, it is not enforced – meaning that the water is not required to be tested for PFAS compounds. The US Food and Drug Administration (FDA) confirmed that forever chemicals were detected in many foods. The FDA tested 91 foods, including fresh produce, baked goods, meat, and fish.
Perfluorinated chemicals will continue to be subject to studies, risk assessments, possible regulations, and data collection under several statutes, so product and waste-reduction practices should be considered immediately to reduce potential consequences.
There are solutions to all of these challenges and the new EPA Action Plan; new measures will lead to better protection of potable water from the harmful impacts of forever chemicals.
Understanding the entire range of wastewater management and disposal alternatives can be a daunting task, particularly as increasingly stringent surface water discharge standards take effect or as zero discharge facilities find the management of their waste liquid needs changing over time. Former solutions are no longer options or may be too costly. One alternative that is rapidly gaining traction is deep injection wells.
Deep well injection is a viable leachate management option in many parts of the United States, yet it is often screened out as a possible alternative due to a lack of understanding of the technology or gross misconceptions about its acceptance or applicability. The purpose of the Monte Markley’s paper The Basics of Deep Well Injection as a Leachate Disposal Option is to present the basic technical, economic and regulatory considerations of deep well injection as a technology a facility should evaluate when considering the applicability of geologic sequestration of leachate.
Technical criteria discussed are potential disposal volumes, geologic suitability, chemical compatibility, pre-treatment requirements, and leachate chemistry. The economic considerations are evaluated based on the technical criteria noted above, management of public perception/relations, current leachate management expenditures, the service life of the asset and risk to develop accurate capital, O&M costs, and return on investment. Regulatory considerations include the role of state vs. federal primacy for each state, the general stance of regulatory acceptance in specific areas of the United States, and a discussion of the permitting process and typical reporting requirements.
These key considerations are then integrated into an overall suitability evaluation that an owner can utilize to accurately determine if deep well injection is a viable option and, if so, how to educate other stakeholders and manage the process of implementation as a project moves forward.
About the Author: Monte Markley, PG, SCS Engineers
As a national environmental consulting and contracting firm specializing in managing hazardous substances, SCS Engineers is helping our clients now. Start by reading The Environmental Dangers of PFAS and Technologies for Removing Them, published in WasteAdvantage magazine for use in the solid waste industry and other industrial applications in support of EPA’s Action Plan.
On February 14, 2019, the U.S. Environmental Protection Agency (EPA) Acting Administrator Andrew Wheeler announced EPA’s Per- and Polyfluoroalkyl Substances (PFAS) Action Plan. The PFAS Action Plan is in response to public interest and input the EPA has received over the past year. EPA’s Action Plan identifies both short-term solutions for addressing these chemicals and long-term strategies for states, tribes, and local communities need to provide clean and safe drinking water to their residents and to address PFAS at the source. These actions include: