Perfluorinated Alkyl Substances in Drinking Water

Transcription

1 Perfluorinated Alkyl Substances in Drinking Water Charles D. Hertz, Ph.D. March 16, 2017 Joint Technical Conference PA Section AWWA WWOAP Exton, PA

2 Perfluorinated Alkyl Substances (PFAS) in Drinking Water How the discovery of PFAS in regional supplies informs a national discussion of unregulated substances Presentation Outline PFAS background Drinking water standards Health Advisories Occurrence data UCMR3 additional monitoring importance of lab sensitivity Regulation of unregulated substances 2

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4 PFOS PFOA 4

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6 AFFF aqueous film-forming foam firefighting foam PFOS and/or PFOA C6-Transition-Bulletin.pdf

7 Drinking Water Standards EPA and PA DEP set standards Safe Drinking Water Act regulations Primary standards Secondary standards EPA regulates chemicals in drinking water with enforceable standards: Maximum Contaminant Levels (MCLs) Unregulated chemicals Occurrence data generated through Unregulated Contaminant Monitoring Rule (UCMR) 7

8 PFAS? systematic, science-driven process

9 mandated monitoring for large systems 9

10 EPA mandated monitoring UCMR3: Low rates of occurrence Initially, Reference Concentration = Provisional Health Advisory for PFOS and PFOA

11 Effect of changing Reference Concentrations PFOS: 33 to 124 samples > Ref Conc PFOA: 0 to 32 samples > Ref Conc 11

12 Unregulated just means no MCL Hexavalent chromium Perchlorate Pharmaceuticals & personal care products MTBE PFAS No relationship to: media attention controversy public expectations 12

13 UCMR3 data: national results sorted by PFOS concentration Local Connection: 5 of top 10 results were from Southeastern Pennsylvania

14 UCMR BASE MAIN SYSTEM - EAST Non Detect Detected < HAL Not Sampled or Waiting Aqua PA SAMPLING Sampled systems > 10,000 people Non-detect for PFOS/PFOA everywhere sampled except Bristol Edgely Wells Detection limit was 60 ppt (PFOS & PFOA combined) PEDDLERS VIEW SYSTEM NOT SAMPLED CHALFONT SYSTEM NOT SAMPLED 14

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19 Although not part of regulatory process, Health Advisories can be important

20 Health Advisories exist for many compounds Reference Concentrations Provisional Health Advisories Existed for just two PFAS PFOS: 0.2 ug/l = 200 ng/l = 200 ppt PFOA: 0.4 ug/l UCMR3: 1 st set of national occurrence data Provisional Health Advisory for PFOS became defacto acute MCL Effectively by-passing regulatory process

21 Health advisory timeline for PFAS Change in Reference Concentrations: PFOS and PFOA EPA Provisional Health Advisory, 2009 Short-term adverse health effects PFOS: 200 ppt PFOA: 400 ppt EPA Health Advisory, May 19, 2016 Long-term adverse health effects PFOS + PFOA: 70 ppt

22 PFOA and PFOS Potential Adverse Health Effects Developmental effects to fetuses Developmental effects to breastfed infants Cancer- testicular, kidney Immune effects Thyroid effects Based on both: Laboratory studies, best-available, peer reviewed Epidemiological studies, human populations 22

23 EPA s PFOA/PFOS health advisory: 70 ppt = 70 ng/l Protective Factors 80% home/environment exposure 20% water exposure Over 70 year lifetime 2 liters per day consumption 20% Water 80% Home and environment Home exposure Water exposure Lactating women and children 98% of U.S. has detected blood levels of PFCs 23

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25 PFOS in blood serum, ug/l decrease over time

26 PFOA and PFOS Implementation of Health Advisory Inconsistent implementation (nationally) & confusion Health Advisory has effectively become an acute MCL Actions & expectations from PADEP HA de facto MCL 26

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28 Occurrence of PFAS in Water Occurrence depends on sensitivity of testing methods UCMR3 EPA Method 537 Mandated sensitivity: Minimum Reporting Levels Monitoring outside of UCMR3 program More sensitive version of method Lower MRLs If you look harder you will find more 28

29 UCMR3 less sensitive Mandated MRLs 40 ng/l PFOS 20 ng/l PFOA Post-UCMR3 more sensitive MRL depends on lab 2 10 ng/l 29

30 Aqua s PFAS detection timeline EPA Monitoring (UCMR3) Begins w/ Higher limits January 2013 EPA Monitoring Concludes December 2015 Bristol Monitoring follow up February 2016 Horsham Interconnect Monitoring April 2016 Rapidly changing EPA Changes Health Advisory May 2016 Bucks & Mont Co. Monitoring May - current 1/13 12/15 2/16 4/16 5/16 7/16 UCMR3 PFOS, MRL: 40 ng/l PFOA, MRL: 20 ng/l MRL: 2.5 ng/l 30

31 AQUA SAMPLING Feb. April 2016 BASE MAIN SYSTEM - EAST Non Detect Detected < HAL Not Sampled or Waiting AQUA SAMPLING FEB to APRIL Used lower reporting level (2.5ppt) Sampled sources and interconnects Detected PFOS/PFOA everywhere except Southampton Interconnect PEDDLERS VIEW SYSTEM NOT SAMPLED CHALFONT SYSTEM NOT SAMPLED 31

32 Regional Impacts on Watersheds 25 miles downstream Park Creek Little Neshaminy Creek Neshaminy Creek 32

33 Watershed Sampling: Little Neshaminy Creek 33

34 Watershed Location Little Neshaminy PFOS + PFOA, ng/l Proportion of Valley Rd % Sept. Rushland 160 Rushland % Sept Aug Neshaminy Bristol Rd 17 Bristol Rd 20 46% Sept Aug

35 PFAS Testing LC / MS / MS 35

36 Neshaminy Watershed Samples, Dec Combined PFOS + PFOA North Branch Neshaminy ND (< 2.4 ng/l) Pine Run 9.9 Rushland 15 Route Bristol Road

37 Little Neshaminy Watershed, Dec Combined PFOS + PFOA Park Creek 122 ng/l Little Valley Road 69 Little Rushland 51 Little Kansas Road

38 Voluntary monitoring post-ucmr3 more sensitive version of lab method Detected only with lower MRLs: 2.5 ng/l 38

39 Neshaminy Raw PFOS, ng/l PFOA, ng/l

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41 Treatment: Granular Activated Carbon Plans for GAC contactors Aqua PA Chalfont Aqua PA Hatboro Horsham Water & Sewer Authority Warminster Water Authority PAC experiments at Neshaminy WTP Additional treatment with anion exchange Pilot status 41

42 What is Aqua doing? Developing a regional strategy and toolbox of options to address PFOA/PFOS for Aqua systems that includes: Conducting sampling of sources to ensure levels remain below the HA Working with federal, state, and local agencies on actions to reduce PFOA/PFOS discharging into the Neshaminy Creek Partnering with EPA and PADEP to identify other sources of these chemicals in and around our groundwater sources Communicating our findings and results Examining potential treatment improvements so if levels were to increase, we can react to protect our customers 42

43 Charles Hertz 762 W. Lancaster Ave Bryn Mawr, PA