Grantee Research Project Results
2023 Progress Report: Understanding PFAS Contaminants in Wastewater Plants in Delaware
EPA Grant Number: EM840531Title: Understanding PFAS Contaminants in Wastewater Plants in Delaware
Investigators: Coleman-Kammula, Seetha , Powley, Charles , Coleman, Brian
Institution: Science, Technology and Research Institute of Delaware (STRIDE)
EPA Project Officer: Ludwig-Monty, Sarah
Project Period: February 1, 2023 through January 31, 2025
Project Period Covered by this Report: February 1, 2023 through January 31,2024
Project Amount: $80,000
RFA: Congressionally Directed Spending (2022)
Research Category: PFAS Detection , Watersheds , Endocrine Disruptors , Environmental Justice
Objective:
The project aims to identify the extent of per- and polyfluoroalkyl substances (PFAS) contamination in wastewater in Delaware. If PFAS containing wastewater is discharged into surface water and soil, PFAS compounds being highly mobile can migrate into drinking water sources. The results of our research will help identify means to prevent contamination of drinking water supplies, thereby supporting EPA's Goal 5 and Objective 5.1.
Progress Summary:
This is a summary of the results from the first year of a two-year project.
- EPA Method 1633 has been used to analyze inflows to and outflows from three wastewater treatments plants (WWTPs) in Delaware. One of the plants (B) processes landfill leachate (LFL) and "green sand backwash water" both of which have been analyzed as part of the project.
- Initial results show no clear pattern of seasonal variation in PFAS content.
- Water leaving from 2 of the 3 WWTPs was found to have a hazardous index (as proposed by EPA for drinking water) of less than 1. All three plants had PFOS above but close to the proposed drinking water MCL for PFOS. All samples from the three plants had PFOA levels of twice the proposed drinking water MCL or more.
- LFL going to plant B was found to be a major source of PFAS to the plant. Total PFAS by Method 1633 ranged from 17.6 to 23.7 µg/L (ppb) with 5:3 FTCA the largest component (9 - 15 µg/L). "Green sand backwash water" is also an input to plant B. It was found to have total PFAS by Method 1633 of 177 to 241 ng/L with PFOS the largest component (71 - 120 ng/L)
- Samples of biosolids have been analyzed from two WWTPs. One from plant A had 22 ng/g of 5:3 FTCA as the major PFAS detected. The second sample (plant C) had PFOS (19 ng/g) as the major PFAS, and PFDA (14 ng/g) as the second most detected PFAS.
- We have just started analyzing for fluorotelomer phosphate diesters (diPAPs). The first result indicates that biosolids from plant A had 3.4 ng/g of 8:2 diPAP.
Future Activities:
- Further investigation of seasonal variation in PFAS at the three WWTPs.
- Expand the scope of diPAP analysis.
- Define reaction conditions for using TOP Assay to indicate concentrations of precursors in influent, effluent and biosolids.
Supplemental Keywords:
Wastewater, influent, effluent, biosolids, precursors, EPA Method 1633, landfill leachate, LFL, fluorotelomer phosphate diesters, diPAPsRelevant Websites:
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.