REPRINT OF USEPA PRESS RELEASE
EPA Moves Forward on Key Drinking Water Priority Under PFAS Action Plan
WASHINGTON (Dec. 4, 2019) — Yesterday, the U.S. Environmental Protection Agency (EPA) sent the proposed regulatory determination for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in drinking water to the Office of Management and Budget for interagency review. This step is an important part of EPA’s extensive efforts under the PFAS Action Plan to help communities address per- and polyfluoroalkyl substances (PFAS) nationwide.
“Under President Trump, EPA is continuing to aggressively implement our PFAS Action Plan – the most comprehensive cross-agency plan ever to address an emerging chemical,” said EPA Administrator Andrew Wheeler. “With today’s action, EPA is following through on its commitment in the Action Plan to evaluate PFOA and PFOS under the Safe Drinking Water Act.”
The action will provide proposed determinations for at least five contaminants listed on the fourth Contaminant Candidate List (CCL4), including PFOA and PFOS, in compliance with Safe Drinking Water Act requirements.
The Safe Drinking Water Act establishes robust scientific and public participation processes that guide EPA’s development of regulations for unregulated contaminants that may present a risk to public health. Every five years, EPA must publish a list of contaminants, known as the Contaminant Candidate List or CCL, that are known or anticipated to occur in public water systems and are not currently subject to EPA drinking water regulations. EPA publishes draft CCLs for public comment and considers those prior to issuing final lists.
After issuing the final CCL, EPA determines whether or not to regulate five or more contaminants on the CCL through a process known as a Regulatory Determination. EPA publishes preliminary regulatory determinations for public comment and considers those comments prior to making final regulatory determinations. If EPA makes a positive regulatory determination for any contaminant, it will begin the process to establish a national primary drinking water regulation for that contaminant.
For more information: www.epa.gov/ccl
Background on the PFAS Action Plan
PFAS are a large group of man-made chemicals used in consumer products and industrial processes. In use since the 1940s, PFAS are resistant to heat, oils, stains, grease, and water—properties which contribute to their persistence in the environment.
The agency’s PFAS Action Plan is the first multi-media, multi-program, national research, management and risk communication plan to address a challenge like PFAS. The plan responds to the extensive public input the agency received during the PFAS National Leadership Summit, multiple community engagements, and through the public docket. The PFAS Action Plan outlines the tools EPA is developing to assist states, tribes, and communities in addressing PFAS.
EPA is taking the following highlighted actions:
Highlighted Action: Drinking Water
Highlighted Action: Cleanup
Highlighted Action: Monitoring
Highlighted Action: Toxics
Highlighted Action: Surface Water Protection
Highlighted Action: Biosolids
Highlighted Action: Research
The agency is also validating analytical methods for surface water, ground water, wastewater, soils, sediments and biosolids; developing new methods to test for PFAS in air and emissions; and improving laboratory methods to discover unknown PFAS.
Highlighted Action: Enforcement
Highlighted Action: Risk Communications
For more information, article, and treatment options visit SCS Engineers.
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.