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PFAS: Like Nothing We’ve Seen Before
MI Chapter APWA Annual ConferenceMay 23, 2019
Scott Bell, P.E.
Contents• What are PFAS?
• PFAS uses and sources
• What makes PFAS so different?
• Exposure risks and regulatory standards
• Michigan PFAS response
• Regulatory Updates
• Technical Updates
• Other sources of information
What are PFAS?
PFAS = Per- and PolyfluorinatedAlkyl Substances• Manmade organic compounds with 4+ carbon atoms in a chain, plus a
“functional group”
• Fluorine attached to carbons instead of hydrogen
– Perfluorinated = all carbon atoms have attached fluorine atoms
– Polyfluorinated = most carbon atoms have attached fluorine atoms
What are PFAS? PFAS are surfactants
• Reduce surface tension in liquids – Key reason for use in plating
• Both hydrophobic and hydrophilic
• Soluble in water
• Low volatility
• Extremely stable– Carbon-fluorine bond
What are PFAS?
When people say “PFAS”, they usually mean:
• One or more regulated PFAS, such as PFOS (perfluorooctanesulfonic acid) or PFOA
(perfluorooctanoic acid), which are the most regulated PFAS in the U.S.
OR
• The sum of the 14 PFAS measured in drinking water using USEPA Method 537.1
Per- and Polyfluorinated
Substances (PFAS)
Per-fluorinated
Poly-fluorin
ated
Per-fluoro-alkylAcids
(PFAAs)
Non-PFAAs
Perfluoroalkyl
Carboxylic Acids (PFCAs)
Perfluoroalkyl
Sulfonic Acids
(PFSAs)
C4 - PFBAC5 - PFPeAC6 - PFHxAC7 - PFhpAC8 - PFOAC9 - PFNAC10 - PFDAC11 - PFUnAC12 - PFDoAC13 - PFTriDAC14 - PFTeDA
C4 - PFBSC5 - PFPeSC6 - PFHxSC7 - PFhpSC8 - PFOSC9 - PFNSC10 - PFDS
What are PFAS?
Current commercial labs will report these 11 PFCAs and 7 PFSAs, along with 6 other “precursor compounds”
PFAS Uses and Sources
1938• DuPont discovered polytetrafluoroethylene (PTFE)
1945• 3M licensed electrochemical fluorination ECF, DuPont registers Teflon trademark
1952• Scotchgard formula discovered by 3M
1954• PTFE first used for non-stick cookware
Mid-1960s
• Use of perfluorocarboxylates (PFCAs) in consumer products (textile and leather treatment, cookware, floor polish, etc.) becomes widespread
Late 1960s
• Use of PFAS in firefighting foam (aqueous film-forming foam, AFFF) begins
2002• 3M voluntarily discontinues production in US
PFAS Uses and Sources
Food packaging paper
Pharmaceuticals Fabric protection
Outdoor apparel
Non-woven fabrics
Leather treatment
Electronics Non-stick cookware
PFAS in Consumer & Commercial Goods
Aqueous film-forming foam (AFFF)
Chrome plating
Landfill leachate
Major Industrial & Commercial PFAS Uses(Current Regulatory Focus)
PFAS Uses and Sources
Other industries: petroleum refining, molding, forging, etc.
Biosolids land application
Paper productionLandfill leachate
Potential Sources of PFAS Under Investigation
PFAS Uses and Sources
What Makes PFAS So Different?
• PFAS are toxic to people
• PFAS stick around a long time.
• PFAS are everywhere.
• There are a lot of PFAS compounds and
we can’t measure all of them.
What Makes PFAS So Different?
Human health risks – multiple PFAS health concerns (ATSDR*):
• Affect growth, learning, and behavior of infants and older children
• Liver damage
• Thyroid disease
• Decreased fertility
• Asthma
• Increase serum lipid (cholesterol) levels
• Increased risk of cancer (esp. kidney, testicular, thyroid)
• Decreased birth weight and other birth defects
• Possible links to osteoarthritis and risk of early menopause
Source: https://www.atsdr.cdc.gov/pfas/health-effects.html
What Makes PFAS So Different?
PFAS stick around a long time
Chemical Group Half Life in Soil
PFAS 1–3 years1
PCBs ~2.6 years2
Dioxins ~13 years2
2NIH, July 20142California OEHHA, 2000
What Makes PFAS So Different?
PFAS stick around a long time
Chemical Group Half Life in Human Tissue
PFAS 2 – 9 years1
Dioxins 7 – 11 years2
PCBs 10 – 15 years3
1USEPA, 20092World Health Org., Oct. 20163Ritter, et al., Env. Health Perspectives, v119 n2 Feb. 2011
What Makes PFAS So Different?
PFAS stick around a long time• Referred to by many as the “forever chemicals”.
• The carbon-fluorine bond is one of the strongest chemical bonds known.
• Transformations in the environment most often involve replacement of
non-fluorine atoms with fluorine atoms – from “poly” to “per”.
• PFAS are not destroyed by standard incinerators – some studies suggest
>900o C is necessary for destruction.
What Makes PFAS So Different?
PFAS are everywhere• A 2009 peer-reviewed paper in ES&T
concluded that 135,000 tons of POSF,
a compound created to synthesize
other PFAS, were produced globally
between 1970 – 2002.
• Estimate based on 3M production
records.
• Production has continued elsewhere in
the world since 2002.
What Makes PFAS So Different?
PFAS are everywhere• A 2015 report by a European
environmental agency concluded that
there are “more than 3,000
commercial highly fluorinated
substances in circulation on the
global market.”
What Makes PFAS So Different?
PFAS are everywhere• A USEPA national drinking water study
(2013-2015) found PFAS in 194 of
4,864 public water supplies tested.
• These supplies serve 16.5 million
people in 33 states
Map credit: Hu, et al., ES&T, 2016
What Makes PFAS So Different?
PFAS are everywhere• 2018 MDEQ sampling found PFAS in
179 of 1,744 water supplies tested.
• All but 2 were below the Federal screening level of 70 ppt for PFOA & PFOS.
• Quarterly monitoring started on 62 (map).
• Sampling of 750 non-community wells planned this year.
Map credit: Hu, et al., ES&T, 2016
What Makes PFAS So Different?
There are a lot of PFAS (and we can’t measure them all)
• In 2018, the OECD published their
findings that 4,730 different PFAS
compounds had been catalogued.
• Compare this with the “standard list” of
24 PFAS compounds currently reported
by commercial labs.
PFAS 4,730 compounds
PCBs 209 congeners
Dioxin 75 compounds
What Makes PFAS So Different?
There are a lot of PFAS (and some of the ones we can’t measure can transform to the regulated compounds)
What Makes PFAS So Different?
Potential liability concern for local governments
• Drinking water supplies
• Wastewater treatment plants– Discharge limits
– Land application of biosolids
• Airports (AFFF)
• Landfills (both closed and operating)
• Fire departments (AFFF)– Past fire response locations?
Exposure Risks and Standards
Human exposure pathways
• General public
– Primary exposure through ingestion (water & food)
– Dermal contact and inhalation are not considered significant for general public
– Per the ATSDR:
“Studies have shown that only a small amount of PFAS can get into your body through your skin. Therefore, showering and bathing in water containing PFAS should not increase exposure. Washing dishes in water containing PFAS should not increase exposure.”
• Workers in industries where high-concentration PFAS materials are used may be exposed through inhalation or dermal contact
Exposure Risks and Standards
Ecological risks
• PFAS are persistent and bioaccumulative.
• Ecological receptors are not currently drivers in Michigan, except as human food
source.
• Standards related to aquatic toxicity are much higher than for human health.
Exposure Risks and Standards
MDEQ: State surface water quality standards (Rule 57 values, mg/l)
• HNV (DW) – Maximum water concentration at which adverse noncancer effects are not likely to occur in the human population from lifetime exposure through drinking the water.
• HNV (NDW) – Maximum water concentration at which adverse noncancer effects are not likely to occur in the human population from lifetime exposure through conducting water-related recreation activities or consuming fish from the water.
• FCV – The concentration that does not allow injurious or debilitating effects in an aquatic organism resulting from repeated long-term exposure.
• AMV – Maximum concentration to which an aquatic community can be exposed briefly without resulting in unacceptable effects.
• FAV - level of a chemical or mixture of chemicals that does not allow the mortality or other specified response of aquatic organisms to exceed 50% when exposed for 96 hours.
Compound Human NoncancerValue (DW)
Human NoncancerValue (NDW)
Final Chronic Value
Aquatic MaximumValue
Final Acute Value
Year
PFOS 0.011 0.012 140 780 1,600 2014
PFOA 0.42 12 880 7,700 15,000 2010/11
Exposure Risks and Standards
MDEQ: State groundwater cleanup values (Part 201 criteria)
*GSI – Groundwater/surface water interface.
Compound Groundwater -Drinking Water Pathway (mg/l)
Soil –Drinking Water Pathway (mg/kg)
Groundwater – GSI* Pathway (mg/l)
Soil – GSI* Pathway (mg/kg)
Year
PFOS 0.07 - 0.012 0.24 2018
PFOA 0.07 - 12 10,000 2018
PFOS + PFOA 0.07 - - 2018
Michigan PFAS Response
Wolverine Worldwide
• May 2016: USEPA - HALs for PFOS & PFOA = 70 ppt.
• January 2017: MDEQ learns of PFAS at former landfills used by
Wolverine Worldwide, groundwater testing begins, PFOS found.
• October 2017: Wolverine announces whole-house water filters for
300 homes.
• November 2017: Michigan PFAS Action Response Team (MPART)
created by Governor Snyder.
– temporary body “to investigate sources and locations of PFAS
and protect drinking water and public health.”
• January 2018: MDEQ announces groundwater cleanup criteria
under Part 201; Accelerated testing begins on rivers, public water
supplies, other sites.
Michigan PFAS Response: fast, aggressive
Since 2017, Michigan has been looking for PFAS “sites”
• Military bases
• Industrial dischargers
• Airports
• Municipal WWTPs
• Landfills
• Public water supplies
• Water bodies (lakes & rivers)
• Old fire sites
Michigan PFAS Response: multi-agency
• EGLE (formerly MDEQ) is the lead agency –multiple divisions involved
– Water Resources Division (WRD)
– Remediation and Redevelopment Division (RRD)
– Drinking Water and Municipal Assistance Division
• Michigan Dept. of Health & Human Services
– Consultation when drinking water supplies are potentially at risk
– Responsible for issuing fish consumption advisories
• Michigan Dept. of Natural Resources
– Routinely conducting fish tissue testing for PFAS, since 2011
– Currently (2018) conducting deer tissue testing for PFAS
• County Health Departments
– Consultation when drinking water wells are potentially at risk
• USEPA –No known involvement in MI PFAS sites except Wolverine
Michigan PFAS Response: low standards
State surface water quality standards
Compound Human Noncancer Value (DW)
Human NoncancerValue (NDW)
Final Chronic Value
Aquatic MaximumValue
Final Acute Value
Year
PFOS 0.011 0.012 140 780 1,600 2014
PFOA 0.42 12 880 7,700 15,000 2010/11
State groundwater cleanup values
Compound Groundwater -Drinking Water Pathway (mg/l)
Soil –Drinking Water Pathway (mg/kg)
Groundwater – GSI* Pathway (mg/l)
Soil – GSI* Pathway (mg/kg)
Year
PFOS 0.07 - 0.012 0.24 2018
PFOA 0.07 - 12 10,000 2018
PFOS + PFOA 0.07 - - 2018
Michigan PFAS Response: public health focus
Overwhelming focus is on human health protection, so DHHS is involved.
Dept. of Health and Human Services:
• Public health authority, no promulgated standards, but policy action levels.
• MDEQ working closely with DHHS.
• DHHS has been developing “decision trees” for sites with PFAS groundwater
impacts.
Michigan PFAS Response: public health focus
Any PFAS detected in
res well?
PFOA+PFOS ≥ 1500 ppt?
NO
No public health recommendations for
PFAS.
• Suggest: follow-up sampling to assess long-term conditions.
• Suggest: continue assessing potential for GW contamination in area.
NO
YES
Recommend monitoring DW and/or GW to
determine if concentrations are
increasing over time, orrecommend POU filter
as a presumptive interim measure until plume is
defined.
• Recommend: continue assessing potential for GW contamination in area.
YES
NO
Advise alternative water source or POU
filter as interim measure and seek new permanent
water source as long-term measure.
• Advise: Continue assessing potential for GW contamination in area.
YES
Advise alternative water source or
whole-house filter with monitoring as
interim measure and seek new permanent water source as long-
term measure.
• Advise: Continue assessing potential for GW contamination in area.
Total PFAS ≥ 70 ppt?
PFOA+PFOS ≥ 70 ppt?
NORecommend
POU filter as a presumptive
interim measure until plume is
defined.
• Recommend: continue assessing potential for GW contamination in area.
YES
Michigan PFAS Response – What’s Next?
Further investigations by EGLE:
• Municipal WWTP biosolids:– Data collection by State, initiated in October 2018
– PFAS standards for land application?
• Fire departments– State issued RFP on May 15, seeking contractor “for the collection, consolidation and disposal of
6% Class B aqueous film forming foam (AFFF)”.
– Fire departments can continue using Class B foam, but are required to report use via the State’s
Pollution Emergency Alerting System (PEAS) hotline.
• Site Investigations– EGLE has begun sending “compliance communications” under Part 201 for PRPs to investigate
PFAS
– Also planning to require investigation at RCRA sites (likely to include landfills)
Michigan PFAS Response – What’s Next?
New screening levels from the Department of Health and Human Services:
Lower screening levels for PFOA/PFOS and new screening levels for other PFAS could trigger more investigation and response actions.
PFAS Compound DHHS drinking water screening level
PFOA 9 ppt
PFOS 8 ppt
PFBS 1,000 ppt
PFHxS 84 ppt
PFNA 9 ppt
Regulatory Updates
USEPA PFAS Action Plan (Feb. 2019):
• Establish drinking water MCLs for PFOS & PFOA.
• Designate PFOS & PFOA as “hazardous substances” under federal law.
• “Consider” adding PFAS to Toxics Release Inventory (TRI).
• “Propose” nationwide drinking water monitoring for PFAS.
• New lab methods (coming up)
• Plan has been widely criticized for lack of schedule & specific actions.
Regulatory Updates
New drinking water standards for Michigan:
• Governor Whitmer directed the MDEQ to start rulemaking for PFAS maximum
contaminant levels (MCLs) on March 26, 2019.
• Recommendations for MCLs are due July 1, 2019.
• Must consider:– PFOA
– PFOS
– PFBS
– PFHxS
– PFNA
• Proposed regulations by October 1, 2019 (could be finalized in 2020).
• Prediction: once MCLs are promulgated, they will be adopted as GW cleanup stds.
Technical Updates
New lab methods for PFAS analysis (USEPA lead):
• Non-potable waters – direct injection (Method 8327)
– Groundwater, surface water, storm water
– Expected to be available for public review in summer 2019
• Non-potable waters – solid phase extraction/isotope dilution (Method 8328)
– Groundwater, surface water, storm water
– Also applicable for solid matrices (soil, sediment)
– USEPA plans to add compounds to the “list of 24”
– External validation planned summer 2019
• Probable finalization in first half of 2020
Other Sources of Information
Interstate Technology & Regulatory Council (ITRC)
www.itrcweb.org
• Fact sheets, training opportunities
National Groundwater Association
www.ngwa.org
• Guidance document – currently under revision
LimnoTech
www.limno.com
• Web article series – follow us on Twitter & LinkedIn
Questions?
Scott Bell, P.E.
734-332-1200
@LimnoTech
www.limno.com
@ScottBell_Limno
www.linkedin.com/in/ScottBell-LimnoTech