Item 8 Staff Briefing Slides on PFAS Chemicals — original pdf

Backup

PFAS Update Water & Wastewater Commission Meeting December 4, 2024 Kasi Clay Water Quality Manager Agenda  What are PFAS?  Drinking Water Testing  Future Drinking Water Regulations  Wastewater and Biosolids EPA Studies 2 What are PFAS?  Per- and polyfluoroalkyl substances: man-made chemicals widely used since 1940s - Persistent - Bioaccumulative - Toxic  PFAS Environmental Pathways • Ground and surface water • Wastewater plant effluent, industrial waste • Soil contamination: landfill, industrial • Air: precipitation  Potential health impacts from long-term exposure • Cancer • Reproductive health • Developmental effects 3 Source: US EPA Common PFAS Sources & Historical Uses Drinking Water Testing Regulatory Development Process  UCMR purpose: Collect data on emerging, unregulated contaminants to assist EPA in the determination of future regulations Draft/Final CCL Proposed/ Final UCMR UCMR Monitoring Results Prelim/Final Regulatory Determination Proposed/ Final Rule Six-Year Review Drinking Water Testing 2013/2014 UCMR 3 Testing March 2024 UCMR 5 Q2 Testing July 2024 UCMR 5 Testing October 2023 UCMR 5 Q1 Testing April 2024 UCMR 5 Q3 Testing  Tests treated drinking water collected from each Water Treatment Plant  Quarterly testing over 12-month period  29 PFAS chemicals + lithium How much is one part per trillion?  One drop in three Barton Springs Pools  1.2 square inches in the total area of Austin (305 square miles)  One cent in $10 billion 6 Drinking Water Testing UCMR5 Results Parameter MCL* ppt HFPO-DA (GenX)* Not regulated individually 1.4 PFOA* PFOS* PFNA* PFHxS* PFBS* PFBA PFHxA PFPeA 7 21 Other Compounds 4.0 4.0 10 10 10 N/A N/A N/A N/A Average ppt 0 0.79 0 2.3 0 2.3 0.5 1.2 0 * Regulated beginning 2027 Future Drinking Water PFAS Regulatory Limits PFOA (perfluorooctanoic acid) PFOS (perfluorooctanesulfonic acid) PFNA (perfluorononanoic acid) PFHxS (perfluorohexanesulfonic acid) HFPO-DA (GenX) (hexafluoropropylene oxide dimer acid) PFNA, PFHxS, GenX, and PFBS (Mixture) 8 PFAS Compound Maximum Contaminant Level (MCL) 4.0 ppt 4.0 ppt 10 ppt 10 ppt 10 ppt 1 (unitless Hazard Index) Future Drinking Water Regulations  National Primary Drinking Water Regulation • Now to 2027: Initial UCMR 5 testing determines future monitoring frequency • 2027: Monitoring begins • 2029: Compliance deadline for PFAS treatment  Compliance based on Running Annual Average (RAA) of quarterly testing • Exceedances beyond EPA's MCL require public notice and treatment 9 Future Drinking Water Regulations Projected PFAS Compliance PFOS (perfluorooctanesulfonic acid) 4.0 ppt 1.2 ppt 1.2 ppt PFAS Compound PFOA (perfluorooctanoic acid) PFNA (perfluorononanoic acid) PFHxS (perfluorohexanesulfonic acid) HFPO-DA (GenX) (hexafluoropropylene oxide dimer acid) 10 ppt PFNA, PFHxS, GenX, and PFBS (Mixture) MCL 4.0 ppt 10 ppt 10 ppt 1 (unitless Hazard Index) Davis RAA 0 ppt Ullrich RAA 0 ppt Handcox RAA 0 ppt 3 ppt 0 ppt 0.2 0 ppt 4 ppt 0 ppt 0.3 0 ppt 0 ppt 0 ppt 0 ppt 0 ppt 0.0 2027 – Projected Compliance Monitoring Quarterly Monitoring Quarterly Monitoring Reduced Monitoring 2029 – All WTPs are in compliance with regulations; No treatment required 10 Wastewater & Biosolids EPA PFAS Studies  Publicly Owned Treatment Works Influent Data Collection • Federal Register Notice posted. • Comments closed in mid-November.  National Sewage Sludge Survey • Identify the presence of pollutants in sewage sludge. 11 Questions? December 4, 2024