Characterization and Quantification of per- and polyfluoroalkyl substances in landfill gas and estimate of emissions from U.S. Landfills

EPA Grant Number: RD839600
Title: Characterization and Quantification of per- and polyfluoroalkyl substances in landfill gas and estimate of emissions from U.S. Landfills
Investigators: Barlaz, Morton A. , Field, Jennifer , Simonich, Staci
Institution: North Carolina State University at Raleigh , Oregon State University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2019 through August 31, 2022
Project Amount: $900,000
RFA: Practical Methods to Analyze and Treat Emerging Contaminants (PFAS) in Solid Waste, Landfills, Wastewater/Leachates, Soils, and Groundwater to Protect Human Health and the Environment (2018) RFA Text |  Recipients Lists
Research Category: Drinking Water , Human Health , Health , Water , Water Quality , PFAS In Landfills (2018)

Objective:

The overall research objective is to estimate the mass of PFASs that are present in landfill gas (LFG) and the mass of PFASs emitted as fugitive emissions. Sub-objectives are to (a) develop methods to sample and analyze LFG for targeted and non-targeted PFASs, (b) measure PFAS concentrations at a cross section of U.S. landfills in different climatic regions, (c) develop a model to estimate PFAS production and emissions at the U.S. national scale, (d) evaluate the potential impact of soil attenuation on PFAS emissions, and (e) measure PFAS production from mixed waste and food packaging materials.

Approach:

We will work with landfill operators on strategies to pump LFG through sorbent traps that will be analyzed by low- and high-resolution gas chromatography mass spectrometry. We have commitments from the owners of over 400 landfills across the U.S. so to assure LFG samples from all climatic regions. Samples will be collected from headers to measure overall PFAS production and from individuals gas wells for analysis of the impact of waste age on PFAS concentrations. We will also use near surface LFG sampling and static chambers to qualitatively evaluate the impact of soil attenuation on PFAS concentrations as fugitive PFAS emissions will largely pass through landfill cover soils. Laboratory reactors will be operated to measure PFAS production and to understand the relationship between PFAS production and methane production for residential solid waste and food packaging materials. Finally, we will develop a model to estimate PFAS production and emissions in consideration of LFG production and emissions, climate, waste age and PFAS concentrations. Monte Carlo analyses will be used to estimate probable ranges in consideration of uncertainty.

Expected Results:

The research will (a) result in a quantitative estimate of the mass of PFASs produced and emitted at landfills as well as characterization (fingerprint) of what we expect will be a broad array of volatile PFASs in LFG, (b) complement an existing estimate of U.S. PFAS emissions via the landfill leachate pathway, and (c) result in a model to estimate a probable range of production and emissions that has the flexibility to vary input parameters as more information becomes available. There are several programmatic implications of this research: (a) Are PFASs from LFG a significant source in the context of national PFASs released to the atmosphere? (b) Are PFAS concentrations impacted by waste age which would enable predictions of the longevity of the measured emissions? (c) Are PFASs released early in the decomposition cycle or evenly throughout the decomposition cycle? Their early release would suggest the advantage of the early installation of gas collection systems.

Supplemental Keywords:

landfill gas, emissions inventory, landfill model, packaging