A Primer on PFAS: A Contaminant Emerged

Transcription

1 : A Contaminant Emerged Stephen G. Zemba, Ph.D., P.E. and Russell H. Abell, P.G., LSP Sanborn Head & Associates, Inc. 20 Foundry Street, Concord, NH /3/2018 Page 1

2 Presentation Outline PFAS Basics Relevance to Oil & Gas Industry PFAS Health Effects 4/3/2018 Page 2

3 PFAS THE BASICS 4/3/2018 Page 3

4 Compounds) PFAS Per- and Poly- Fluoroalkyl Substances Fluorocarbon Tail Strong bonds Hydrophobic Oleophobic Varying length F F F F F F F F F F F F F F F O OH perfluorooctanoic acid (PFOA) FF F F F F F F FF F F F F F F S O OH O perfluorooctane sulfonic acid (PFOS) Functional Group Strong to weak acids Hydrophilic 4/3/2018 Page 4

5 PFAS In the News 2015: PFOA found in Drinking Water in Hoosick Falls, NY EPA Launches Cross-Agency Effort to Address PFAS (Press Release, 12/04/17) Federal Register Notice May 25, /3/2018 Page 5

6 PFAS in the Environment Entered commerce in 1940s Some compounds phased out AFFF use for firefighting Household products Stormwater runoff/street dust Industrial/commercial facilities Textile coaters Chromium platers Car washes PFAS-containing wastes Landfills Wastewater treatment effluent/biosolids 4/3/2018 Page 6

7 Important PFAS Characteristics Soluble in water Resistant to degradation Low volatility Primary transport pathways Air Deposition Surface water transport Groundwater migration Primary exposure pathway Ingestion of groundwater 4/3/2018 Page 7

8 State Groundwater Standards State PFOA PFOS Notes Al, CA, CO, DE, FL, NY, RI 70 ng/l 70 ng/l Adopted EPA HAL AK, IL 400 ng/l 200 ng/l Maine 60 ng/l 100 ng/l Massachusetts PFAS are regulated; Anticipated in 2018 Michigan 70 ng/l 70 ng/l Minnesota 35 ng/l 27 ng/l New Jersey 40 ng/l --- Proposed PFOA 14 ng/l; PFNA 10 ng/l New Hampshire 70 ng/l 70 ng/l North Carolina 2,000 ng/l --- Texas 290 ng/l 560 ng/l Vermont 20 ng/l 20 ng/l West Virginia 500 ng/l --- 4/3/2018 Page 8

9 PFAS Occurrence in Large Data Sets `Study/Site PFOA DF (# detects) > 70 ng/l PFOS DF (# detects) > 70 ng/l Number of Sample Locations Sample Type UCMR3 0.3% (13) 0.9% (46) 4,920 Public Systems NH Domestic Private Wells Study/Site 12.1% (214) 0.7% (12) 1,762 Domestic Wells PFOA DF (# detects) > 400 ng/l PFOS DF (# detects) > 200 ng/l Number of Sample Locations Sample Type UCMR3 0% (0) 0.4% (19) 4,920 Public Systems NH Domestic Private Wells 0.9% (16) 0.1% (2) 1,762 Domestic Wells 4/3/2018 Page 9

10 RELEVANCE TO THE OIL & GAS INDUSTRY 4/3/2018 Page 10

11 11 Concerns to the Oil & Gas Industry Firefighting and/or fire suppression system O&M Disposal/management of AFFF Stormwater/runoff Drilling fluids? Listed by UNEP as a surfactant used in oil well stimulation 4/3/2018 Page 11

12 12 Class B Foams and PFAS Note: Class B fires relate to flammable liquids/gases and petroleum greases and tars AFFF = Aqueous Film Forming Foams Products labeled AFFF likely contain PFOS and some PFOA if manufactured in the 1970s-2000s timeframe AFFF purchased before 2010(?) should be suspected to contain PFOS and PFOA 4/3/2018 Page 12

13 13 Potential Release Scenarios Active discharge (e.g., to fight fires) System testing quantities may not need to be large Fire drill areas Losses and leaks from systems 4/3/2018 Page 13

14 PFAS HEALTH EFFECTS Hu et al., /3/2018 Page 14

15 15 PFAS Toxicity: General Findings Most studies have focused on PFOA and PFOS Both PFOA and PFOS bioaccumulate in human blood, PFOS more so PFAS chain length roughly relates to half-life and potential toxicity PFAS persist in humans for years, but in rats and mice for only days to weeks 4/3/2018 Page 15

16 C8 Panel Studies Industrial Facility Wood County, WV Probable links between PFOA exposure and: Diagnosed high cholesterol Ulcerative colitis Thyroid disease Testicular and kidney cancers Pregnancy-induced hypertension No correlations with: Birth defects Miscarriages and stillbirths Preterm birth and low birth weight Liver disease 19 other cancers and 11 other non-cancer effects 4/3/2018 Page 16

17 PFAS Reference Dose PFOA and PFOS toxicity studies point to non-cancer health effects Reproductive study in mice is the basis of EPA s Reference Dose of 20 ng/kg-d for PFOA+PFOS Liver enlargement first proposed then dropped Chosen development effects are not permanent Other authorities have assigned higher values Authority/Agency U.S. EPA (2016) Reference Dose (ng/kg-d) PFOA 20 (total for both) PFOS European Food Safety Authority (2008) Danish EPA (2015) Health Canada (2016, proposed) /3/2018 Page 17

18 18 Does PFAS Cause Cancer? Evidence of PFAS carcinogenicity from C8 Panel studies and animal studies is inconsistent and/or inconclusive Results of local health studies have been negative or inconsistent Hoosick Falls, NY (2017) only lung cancer statistically elevated Merrimack, NH (2018) no significantly different cancer rates, including cancers associated with PFOA Washington and Dakota Counties, MN (2018) overall cancer rate same as statewide Issue is somewhat moot as non-cancer health effects are driving the 70 ppt Health Advisory, and this level is protective of potential cancer risk 4/3/2018 Page 18

19 U.S. EPA s Lifetime Health Advisory Issued May 19, 2016 Applies to sum of PFOA + PFOS 70 ng/l based on developmental study in mice Basis: Lowest effects level of 1 mg/kg-d delayed ossification in pups and hastened male puberty Metabolic adjustment to mg/kg-d to account for much longer halflife in humans Add safety/uncertainty factors totaling 300: 10 (sensitive individuals) 3 (inter-species) 10 (LOAEL to NOAEL) to get reference dose of mg/kg-d = 20 ng/kg-d Only 20% of exposure from drinking water 4/3/2018 Page 19

20 Variability in Risk-Based Standards Regulatory authorities are making different assumptions and interpretations in the face of uncertainty Results thus far: Substantial variability and in some cases adoption of very protective assumptions Regulatory Authority Receptor Chemical Reference Dose (ng/kg-d) Background Exemption Exposure Rate (l/kg-d) Risk-Based Concentration (ng/l = ppt) U.S. EPA VT DOH TX CEQ Nursing mother Nursing infant Small child PFOA + PFOS PFOA + PFOS 20 80% % PFOA % PFOS /3/2018 Page 20

21 21 PFOA Levels in Blood (µg/l) Background levels decreased from 5 µg/l in late 1990s to present 2 µg/l Exposure to PFOA in water elevates levels in blood Bioconcentration over time ~100-fold 4/3/2018 Page 21

22 22 PFAS Health Risks - Summary Toxicity data limited and not consistent Most studies have focused only on PFOA and PFOS Epidemiological studies and laboratory animal studies have not shown consistent and conclusive findings Cancer incidence studies in NY, NH, and MN not indicative of PFAS effects Risk-based standards/guidelines for PFOA and PFOS are arguably protective Drinking water exposure elevates PFAS in blood If PFAS is causing health effects, the effects appear to be subtle 4/3/2018 Page 22

23 23 Conclusions Concerns over PFAS continue to strengthen States are leading the charge Lack of strong federal leadership Variability among states is considerable Concerns greatest for drinking water exposure Fire suppression systems may be of greatest concern to the Oil & Gas Industry 4/3/2018 Page 23

24 ITRC PFAS Team : Series of seven PFAS Fact Sheets tailored to the needs of state regulatory program personnel who are tasked with making informed and timely decisions regarding PFAS-impacted sites. - Naming Conventions and Physical and Chemical Properties - Regulations, Guidance, and Advisories - History and Use - Environmental Fate and Transport - Site Characterization Considerations, Sampling Precautions, and Laboratory Analytical Methods - Remediation Technologies and Methods - Aqueous Film-Forming Foam 24

25 25 For Further Information The Interstate Technology Regulatory Council (ITRC) a publicprivate coalition of stakeholders has published a series of fact sheets on PFAS with updated information U.S. EPA s website has information regarding PFAS regulation at If you have questions or comments, you can Stephen Zemba at szemba@sanbornhead.com or Russ Abell at rabell@sanbornhead.com or (for legal/regulatory questions) Matthew Thurlow at mthurlow@bakerlaw.com 4/3/2018 Page 25