PFAS and Landfill Leachate

By:  Ivan Cooper, Principal, Civil & Environmental Consultants, Inc. 

Landfill leachate is facing increased scrutiny as a conduit for discharge of emerging contaminants (EC) to the environment in discharges to POTWs or direct discharge to surface water. Emerging contaminants include Per- and polyfluoroalkyl substances (PFAS); 1,4-Dioxane; pharmaceutical and personal care products (PPCP); rDON; and others. Although drinking water guidelines and standards are much lower than wastewater or leachate limits — few, if any, areas have such limits — the direction is worrisome for landfill managers.

Constituent concentrations are regulated in drinking water by various states at increasingly lower levels than the current EPA Health Advisory limit of the combined 70 ng/L of PFOA and PFOS, and these lower limits could impact the leachate discharge levels that landfills may have to meet.

Typical technologies for removing PFAS and other contaminants from a liquid flow include activated carbon, ion exchange, and reverse osmosis. These technologies use separation approaches instead of contaminant destruction, which causes some concern when it comes to managing residuals. These technologies may require pretreatment, or are used in series with other technologies. Additionally, residuals management may transfer more concentrated fractions to solid waste and air media that requires destructive or solidification treatment or other management approaches.

Landfill leachate poses further consideration, as constituent concentrations of the various emerging contaminants has ranges from low ng/L levels to tens of thousands times that level. In order for activated carbon or ion exchange technologies to remove PFAS, conventional treatment technologies must first be employed to provide a liquid that will not quickly blind the technologies. It is increasingly crucial to identify innovative technologies that are technologically competent and cost effective. In current evaluations for a number of landfill leachate flows, we evaluated a number of innovative destruction technologies, including:

• Modified bentonite adsorbents
• Foam Fractionation
• Supercritical Water Oxidation
• Low Temperature Plasma

These technologies are in their infancy and have shown significant promise. However, there still are concerns about residuals management, complete destruction, or sequestering short chain PFAS. Additional evaluation on treatment processes are also needed to address concerns about treatment results where PFAS precursors become regulated PFAS constituents.

About the Author

Mr. Cooper oversees water and wastewater consulting activities for landfill leachate, power and energy production facilities, pulp & paper, pharmaceuticals and medical waste, chemical manufacturing, primary metals production, and other industrial facilities. He has detailed experience in wastewater permitting, treatability, preliminary and detailed studies and design, construction observation, operation and maintenance manuals, start-up, and operational assistance for municipal and industrial wastewater treatment facilities.

Mr. Cooper has detailed biological and physical chemical treatment experience, including both aerobic and anaerobic digestion of residuals, including gas collection, purification, and CHP (Combined Heat and Power projects). He has prepared several technical manuals for US EPA Technology Transfer program in Alternative Collection and Wastewater Treatment, and delivered over 50 seminars for US EPA on wastewater treatment issues. He has testified in a number of environmental litigations, including residuals and sludge management, domestic wastewater reuse, metals in public water supplies and corrosion in municipal systems.

With over 49 years of technical and management experience, he has evaluated sites, designed water and wastewater treatment plants, performed and reviewed historical and cost evaluations for over 100 landfills and National Priority List (NPL) Superfund sites and has conducted the preliminary and detailed design of over 100 industrial and municipal waste treatment systems and sewage systems. Mr. Cooper has conducted environmental assessments, water supply feasibility studies, financing and utility rate studies, and reproduction cost studies. He is certified to serve on a value engineering team.

Mr. Cooper is the chair of the SWANA Landfill Leachate Technical Committee, past chair of the Residuals Management and Solid Waste sections of the TAPPI Environmental Division, member of the Water Environment Federation Industrial Wastewater Committee, past chair of the Disaster Preparedness Committee of the NC AWWA-WEA and past chair of the Industrial Wastewater Committee of the NC AWWA WEA.