pfas impacts resulting from fire protection: management ... · © arcadis 2016 contents pfas...
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PFAS Impacts Resulting from Fire Protection:
Management and Mitigation Options
Ian Ross, Ph.D., Arcadis, Leeds, United Kingdom
Erika Houtz, Ph.D., Arcadis, San Francisco, CA
Jeffrey McDonough, Arcadis, Newtown, PA
Jonathan Miles Ph.D., Arcadis, Leeds, United Kingdom
Jake Hurst, Leeds, United Kingdom
Peter Storch, Melbourne, Australia
Jeff Burdick, Arcadis, Newtown, PA
© Arcadis 2016
Contents
PFAS Chemistry
Regulatory Evolution
Analytical Challenges / Advanced Analytical Solutions
Fate and Transport / Site Conceptual Model
Foam Evolution
Remediation Case Study
Summary
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Perfluorinated compounds (PFCs)
PFAAs totally resist biodegradation & biotransformation so are extremely persistent
• Perfluorinated Compounds (PFCs) generally are the Perfluoroalkyl acids (PFAAs)
• PFAAs include:
• Perfluoralkyl carboxylates (PFCAs) e.g. PFOA
• Perfluoroalkyl sulfonates (PFSAs) e.g. PFOS
• Perfluoroalkyl phosphinic acids (PFPiS); perfluoroalkylphosphonic acids (PFPAs)
• There are many PFAAs with differing chain lengths, PFOS and PFOA have 8 carbons (C8) -octanoates
July 2016 3
C1 Methane
C2 Ethane
C3 Propane
C4 Butane
C5 Pentane
C6 Hexane
C7 Heptane
C8 Octane
C9 Nonane
C10 Decane
C11 Unodecane
C12 Dodecane
C13 Tridecane
C14 Tetradecane
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Polyfluorinated Compounds -Precursors
Thousands of polyfluorinated precursors to PFAAs have been commercially synthesized for bulk products
The common feature of the precursors is that they will biotransform to make PFAA’s as persistent “dead end” daughter products
PFAS do not biodegrade i.e. mineralise
Some precursors are fluorotelomers
Some are cationic (positively charged) or zwitterionic(mixed charges) –this influences their fate and transport in the environment
Cationic / zwitterionic PFAS tend to be less mobile than anionic PFAAs and so can potentially be retained longer in “source zones”
Environmental fate and transport will be complex as PFAS comprise multiple chain lengths and charges
PFOA
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Useful Graphics5
Diversity of PFAS Characterised in AFFF
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AFFFComposition
Precursors
% Precursors 1.2 19.5 18.8 21.9 19.1
% PFOS 80.5 66.1 69.6 63.5 65.0
% Shorter Chain PFAAs 18.3 14.4 11.5 14.7 15.9Property of Arcadis, all rights reserved
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100% Precursors
NO PFOS or
PFOA
AFFFComposition
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9
Aerobic Precursor Biotransformation toDead End PFAAs
Fire Training Facilities
Landfill
Biosolids Land Application
Manufacturers of Derivative Products
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REGULATORY CLIMATE / PFAS DISTRIBUTION
Evolution of regulatory understanding globally and global distribution
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Evolving Regulatory PFAS Values – OverviewDrinking, Surface and Ground Water (mg/l)
PFOS O=8
PFOA O=8
PFBS B=4
PFBA B=4
PFPeA/S Pe=5
PFHxA Hx=6
DENMARK(Drinking & Groundwater)
FEDERALGERMANY
(Drinking Water)
(0.1)
UK(Drinking Water)
AUSTRALIA(Drinking Water)
(0.09)
THE NETHERLANDSUS EPA(Drinking Water)
VERMONT(Drinking Water)
MINNESOTA(Drinking Water)
NEW JERSEY
CANADA(Drinking Water)
PFHxS Hx=6
PFHpA Hp=7
PFOSA O=8
PFNA N=9
PFDA D=10
COMPOUND REGULATED AND CHAIN LENGTH KEY
(0.07)
ITALY(Drinking Water)
(0.07)
TEXAS-Residential(Groundwater)
0.56
(1)
0.3/0.3/
0.3/
0.3/
0.3/
3/
7/
3/1/
.030.5
0.5
(0.1)
1
0.60.2
15
30
0.20.2
0.2
0.2
.014.013
(0.02)
.027.035
7
7
0.56
0.29
34
71
.093.093
0.56
0.290.37
.093
0.6
.53
.023ground
drinking
0.5
drinkingdrinking.01ground
0.29
SWEDEN(Drinking Water)
(0.5)(0.5)
(0.5)(0.5)
(0.5)(0.5)
5
STATE OF BADEN-WÜRTTEMBERG
(Groundwater)
0.23/(0.3)
European Surface Waters (PFOS) 0.00065
Australian Surface Waters (PFOS) 0.00023
(0.07)
.005.005
PENNSYLVANIA(Drinking Water
-proposed)
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PFPeA = 0.07
PFHxA = 0.07
PFHxS = 0.07
PFHpA = 0.07
PFOA = 0.07
PFOS = 0.07
PFNA = 0.07
PFOA = 0.07 (0.7)
PFOS = 0.07 (1)
PFOA = 0.4
PFOS = 0.2
PFOA = 0.07 (0.13)
PFOS = 0.07 (0.56)
PFOA = 0.42 (0.089)
PFOS = 0.011 (0.08)
PFBA = 7 (7) [7]
PFBS = (9) [7]
PFOA = [0.3]
PFOS = [0.3]
PFOA = 0.07
PFOS = 0.07
CL = groundwater cleanup level
AL = private well action level
RL = reporting level
PHG = public health goal
Applies to the individual and summed PFOA, PFOS, PFHpA, PFNA, and PFHxS
State YearStandard/
GuidanceType
AK 2016 CL GW
CT 2016 AL GW
DE 2016 RL GW
IA 2016Statewide
Standards
Protected GW
(Non-protected GW)
KY 2016 PHG DW
ME2016
2016
Health-base MEG
RAG
DW
(GW)
MI2015
2016
HNV
GCC
SW
GW
MN
2011
2011
2011
Short-term HRL
Short-term HRL
Chronic HRL
GW
(GW)
[GW]
US GUIDANCE VALUES
PFOA = 0.40
PFOS = 0.40
MEG = maximum exposure guideline
RAG = remedial action guideline
HNV = human noncancer value for surface drinking water
GCC = generic cleanup criteria
HRL = health risk limit
Applies to individual and summed PFOA and PFOS
Draft/proposed values
All concentrations provided as µg/L
© Arcadis 2016
PFOA = 0.07
PFOS = 0.07
PFBS = 667
PFOA = [0.014]
PFNA = 0.010 (0.013)
PFOA = 2
PFHpA = 300
PFOA = 24
PFOS = 300
PFOSA = 0.2
PFNA =1
PFBA = 71
PFBS = 34
PFPeA = 0.093
PFHxA = 0.093
PFHxS = 0.093
PFHpA = 0.56
PFOA = 0.02
PFOS = 0.02
BCL = basic comparison level
AGQS = ambient groundwater quality standard
ISGWQC = interim specific groundwater quality criterion
MCL = maximum contaminant level
IMAC = interim maximum allowable standard
ILR = initiation level
PCL = protective concentration level
PGWES = primary groundwater enforcement standard
Final recommendation from advisory body
State YearStandard/
GuidanceType
NV 2015 BCL DW
NH 2016 AGQS GW
NJ
2015
2016
2017
ISGWQC
MCL
MCL
GW
(DW)
[DW]
NC 2006 IMAC GW
OR 2011 IL SW
TX 2016 Tier 1 PCL GW
VT 2016 PGWES GW/DW
PFOA = 0.29
PFOS = 0.56
PFOSA = 0.29
PFNA = 0.29
PFDA = 0.37
PFDS/PFUnA/PFDoA/PFTrDA, PFTeDA = 0.29
Applies to individual and summed PFOA and PFOS
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US GUIDANCE VALUES
All concentrations provided as µg/L
AL, AZ, CO, CT, MA, WV have adopted the EPA HA as their DW guidance
ANALYTICAL TOOLS
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Useful Graphics 15
• Total oxidizable precursor (TOP) Assay
– Initial LC-MS/MS analysis with re-analysis following oxidative digest
– Detection limits to ~ 2 ng/L (ppt)
– Commercially available in UK, Australia, under development in US
• Particle-induced gamma emission (PIGE) Spectroscopy
– Isolates organofluorine compounds on solid phase extraction,
measures total fluorine
– Detection limits to ~ 15 ug/L ( ppb) F
– Commercially available in US
• Adsorbable organofluorine (AOF)
– Isolates organofluorine compounds with activated carbon and
measures F by combustion ion chromatography
– Detection limits to ~ 1 ug/L (ppb) F
– Commercially available in Germany, Australia
• Time of Flight MS (LCQTOF) MS– Identifies multiple precursors via mass ions capture and accurate mass
estimation (to 0.0001 of a Dalton) to give empirical formulae (e.g.
C10F21O3N2H4)
Advanced Analytical TechniquesExpanding analytical tool box to assess total PFAS
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Total Oxidizeable Precursor Assay (TOP)Oxidation of Precursors to PFAAs with OH
S2O82- 2 SO4
-
Heat
OH-SO4
2- + OHpH>11
NaOH + K2S2O8
Dilute
Sample
pH >12
85 oC
OH•
Approach described in Houtz and Sedlak, ES&T, 2012
R + shorter PFAA
products
PFSA
Precursors
PFCA
Precursors
OH•PFPA
Precursors +8
8
8
OH•
OH•
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TOP Assay Applied to AFFF Formulations: Many formulations appear PFAS-free until precursors are revealed by TOP Assay
0
5
10
15
20
ECF,2001
FT 1,2005
FT 2,2002
FT 3,2009
FT 4,2003
Co
nce
ntr
atio
n, g
/LAFFF Formulations, Pre-TOPA
PFOS
PFHpS
PFHxS
PFBS
PFNA
PFOA
PFHpA
PFHxA
PFPA
PFBA
0
5
10
15
20
ECF,2001
FT 1,2005
FT 2,2002
FT 3,2009
FT 4,2003
Co
nce
ntr
atio
n, g
/L
AFFF Formulations, Post-TOPA
PFOS
PFHpS
PFHxS
PFBS
PFNA
PFOA
PFHpA
PFHxA
PFPA
PFBA
FT = Fluorotelomer-based AFFF
ECF = Electrochemical Fluorination- based AFFF
© Arcadis 2016
Total Oxidizable Precursor (TOP) AssayFire Training Area
Soil CompositeGroundwater Composite
240%
increase
75%
increase
EPA Method 537 Underestimates the PFAS Mass
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Comparison of AOF & TOP Assay with AFFF Impacted Groundwater
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R² = 0.8034
0
10
20
30
40
50
0 10 20 30 40 50
AO
F µ
g/L
(o
rganofluorine e
quiv
ale
nt)
LC-MS/MS Sum PFAS Post-TOP Assay, µg/L(organofluorine equivalent)
© Arcadis 2016
Digest AFFF precursors and measure the hidden mass: TOP Assay
Analytical tools fail to measure the hidden PFAS precursor mass, the TOP assay solves this
Microbes slowly make simpler PFAA’s (e.g. PFOS / PFOA) from PFAS (PFAA precursors) over 20+ years
Need to determine precursor concentrations as they will form PFAAs
Too many PFAS compounds and precursors –so very expensive analysis
Oxidative digest convert PFAA precursors to PFAA’s
Indirectly measure precursors as a result of the increased PFAAs formed
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Conceptual Site Model
Increasing mobility of shorter perfluoroalkyl chain PFAS
C6 C4 C5 C3? C2?
C8 C7 C6 C4 C5 C3? C2?Hidden anionic mobile PFAA
precursors
Anionic precursor biotransformation
increases as aerobic conditions develop
Direction of groundwater flow
0 C8
Anionic PFAA dead
end daughters
0
0
C F S
08 17
0
00H3C 0
C 4H9
0
C8F17 S 0
0
0
00H3C 0
C 4H9
0
0
S 0C8F17
C F
0
0
S 08 17
0
0
C6F13
S 0
0
0
C8F17
0
0
S 0S 0 C8F17
0
0
S 0C8F17
0
S 0C8F17
0
0
S 0
C6F13
0
C6F13
0 0
0
S 0S 0
0 C6F13
Source Zone - Hidden Cationic and Zwitterionic PrecursorsLess mobile as bound via ion exchange to negatively charged fine grain soils
(e.g. silts & clays). Precursor biotransformation is limited by the anaerobic redox
conditions created by the co-occuring hydrocarbons.F
N+
0
0H
0
00
C1H9
C F
H3C 0
0
0
S 08 17
0
0
S
N H
C 8F17
NH+
F
F Cn
0
0 0H
NS
F
F C
F n0
0
H3C 00 C 4H9
0
0H
0
N+F
F
F C
F
C6F13
0
0
S 0 N
NN
S
0 H
0
F
F C
F n
0
0-C5F11
0
H3C 0
0
00H3C 0
C 4H9
0 C4H9
0 0
C6F17 S 0
0
CH
CH
CH
CHCH
CH
CH
AFFF/FFFP/FP
CH3
CH3
CH3
CH3
CH3
Hydrocarbon NAPL Short hydrocarbon plume
-300mV -200mVREDOX
ZONATION-100mV 0mV 100mV 200mV
C7C8
PFAS Source Zones, a CSM
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AFFFComposition
% Cationic 1.2 8.2 9.7 10.6 8.0
% Anionic 98.8 80.5 81.2 78.1 80.9
% Zwitterionic 0.0 11.2 9.1 11.2 11.1
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100% Precursors
NO PFOS or
PFOA
AFFFComposition
% Cationic 0.0 0.0 30.2 30.3 0.0 34.1
% Anionic 100.0 100.0 69.8 0.7 0.0 0.9
% Zwitterionic 0.0 0.0 0.0 69.0 100.0 65.0
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Excessive Costs
August 20, 2017
28
http://greensciencepolicy.org/wp-
content/uploads/2016/09/Rolland-Weber-PFOS-
PFAS-German-activities-Final.pdf
Risk based approaches not adopted in Germany
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Groundwater Risks to Receptors
AFFF / FFFP / FP
Fire training
Incident Response Source – Pathway – Receptor
High concentration, spill site, route
via groundwater to receptor e.g.
drinking water well
Diffuse
Ground level impacts and
ground/surface water
Landfill Leachate
Municipal / Domestic WWTP
Industry & Manufacturing
Agricultural Land
Commercial / Domestic Products
Metal Plating
ASTs –Fuel storage (FFFP / FP)
Grasshopper effect
via widening of source zones
e.g. concentrated plume intercepts crop spray irrigation to make secondary wider source area for more dilute plume
?
?
?
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PFBA BAF 56.8 Lettuce
PFPeA BAF 17.1 Tomato
© Arcadis 2016 August 20, 2017 31
Foams
32
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• Fires involving liquid hydrocarbons are class B and extinguished with fluorosurfactantfoams such as:
o Aqueous Film Forming Foams (AFFF)
o Fluoroprotein (FP)
o Film Forming Fluoroprotein Foam (FFFP)
• AFFF’s were develop in 1960’s and have been used widely to extinguish class B (liquid hydrocarbon) fires
• PFAS foam composition is chemically complex with multiple organofluorinecompounds many of which are not detected by commercially available analytical methods (i.e. precursors or polyfluorinated compounds)
• PFAS foams contains both polyfluorinated and perfluorinated compounds
Class B Fire Fighting Foams
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PFAS Foams being Replaced
• C8 (PFOS and PFOA) phased-out
• C8 replaced with compounds with shorter (e.g., C4, C6) perfluorinated chains
• C4, C6 PFAS are less bioaccumulative, still extremely persistent and more mobile in aquifer systems vs C8 - more difficult and expensive to treat in water and concentrating in fruits and vegetables
• Solutions for characterizing all PFAS species important to cover current and future risks / liabilities
• Regulations addressing multiple chain length PFAS (long and short) are evolving globally
• Fluorine free (F3) foams contain no persistent pollutants
• F3 foams pass ICAO tests with highest ratings for extinguishment times and burn-back resistance, so are widely available as replacements to AFFF
Non-fluorinated replacement foams are being increasingly adopted
Manufacturer F3 Foam
National Foam Jetfoam (Aviaton)
National Foam Respondol (Class B)
Auxquimia UNIPOL
Vsfocum Silvara
Bioex Ecopol
Fomtec Enviro 3x3 Plus
Solberg Re-healing Foam RF6 / RF3
Dr. Sthamer Moussol F-F3/6
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PFAS and F3 Foam Certification
• Currently certification of Fluorine Free (F3) foams differs
• F3 Foams pass ICAO (International Civil Aviation Organisation) tests with the highest possible rankings
• F3 foams not currently US Military Specification (MILspec) certified because.
• Different F3 foams cannot be blended.
• Training required to aerate correctly, challenge for untrained personnel.
• F3 foams cannot work between ½ and 5x correct dose.
• Currently not considered to offer equal protection to the safety of the user as PFAS based foams (shorter projection distance).
• MILSpec created for AFFF -stipulates flourosurfactants
• Costs to change nozzles, pumps for F3 foams, especially large sites.
© Arcadis 2016 36
Foam Policy Queensland, Australia
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Main implications of New Policy
• PFOS legacy foams must be removed from service
• Must be destroyed by high temperature (>1100 C) destruction
• Long chain foams (>C7) must be phased-out by July 2019
• Must be destroyed by high temperature (>1100 C) destruction
• Facility and equipment cleaning with solvent may be required to remove PFOS, PFHxS, PFOA, and PFOA precursors below acceptable levels
• Disposal of impacted infrastructure?
• MSDSs do not provide the information needed for
management decisions
© Arcadis 2016
Main implications of New Policy
• Non-Persistent foam usage going forward
• Needs to be certified fluorine free
– Adsorbable organic fluorine technique can work - ~ <50 mg/kg F acceptable as F free
• Should be contained and disposed of without direct release to the environment where possible
• Emergency use of non-persistent foams is acceptable
• These foams do not form films
Treatment and Restoration
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Dickenson and Higgins, 2016
• Green lines show lead vessel GAC replacement; Orange line shows lead and lag GAC replacement
• Shortest chain (PFBA) breaks through first; PFBA is not regulated currently, but may be subject to future regulation
• Routine O&M/GAC change outs controls contaminant breakthrough; large GAC vessel sizes and lower flow rate will extended GAC lifetime
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ACTIVATED CARBON
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© Arcadis 2016
• PFAS do not biodegrade (mineralise) but biotransform to PFAAs as dead-end
daughter products
• Regulations surrounding PFAS are evolving with lowering drinking water standards
and a focus on increased interest in additional PFAAs and precursors
• Concern over short chain concentration in fruits
• Precursors mass and multiple PFAAs likely accompany PFOS & PFOA in sources and
plumes –depending on exact nature of source material
• Analysis of just PFAA’s can significantly underrepresent the actual PFAS mass
• A CSM is proposed based on TOP and AOF data from a FTA sources and plumes
• Fluorine Free (F3) foams are evolving and being widely accepted
• Remediation options are evolving and being proven using TOP assay
Summary
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Recent Publications
43August 20, 2017
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