Transcript Slide 1

Toxicology of Hydraulic
Fracturing
NYOEMA Annual Conference
October 19, 2012
Michael G. Holland, MD, FAACT, FACMT, FACOEM, FACEP
Clinical Associate Professor, SUNY Upstate Medical University
Consulting Medical Toxicologist
Upstate New York Poison Center, Syracuse, NY
Director of Occupational Medicine
Center for Occupational Health of Glens Falls Hospital
Glens Falls, NY
Background of Fracking
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Hydraulic fracturing first performed in 1947
Has been used on over 1 million producing wells.
Currently, operators now fracture as many as
35,000 wells of all types (vertical and horizontal,
oil and natural gas) each year.
Vertical well sections can be 100-1,000’s of feet
below the land surface
Lateral sections may extend 1000 to 6000 feet
away from the well, often multiple sections and
directions
Background
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Water is pumped into well at high pressure
Exempt from EPA Clean Water Act
The high pressure fractures or opens up
existing fractures in shale.
Water has additives to enhance the
process (more detail later)
Proppants (propping agents, usually sand
or ceramic) are injected to prop open the
new fractures
Background
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Water & its additives are withdrawn
(flowback), and contained or recycled or
disposed of, depending on permit
– Regulated by the National Pollutant Discharge
Elimination System (NPDES)
– Requires flowback to be treated prior to
discharge into surface water or underground
injection (regulated by either the U.S.
Environmental Protection Agency’s (EPA)
Underground Injection Control (UIC) program )
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Oil or gas is then extracted
Do not drink this water
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http://www.youtube.com/v/4ApZkNsXfJE&t=1m
Hydraulic Fracturing Explained
http://www.youtube.com/v/YemK
zEPugpk
Areas of Concern
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Identification and Toxicology of fracking fluids and
additives
Possible groundwater contamination
– By the well and the process itself
– By storage of contaminated water
– NB: Exempt from Safe Drinking Water Act
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Radioactive isotopes
Air contamination from VOC produced by well- methane,
BTEX
Air/water contamination by industrial equipment &
engines used for pumping, extracting, etc.
Traffic, noise, etc in pad area
Horizontal
Wells
Continuous Reservoir
Woodford
Shale
Weakly
Laminated
Shale
Strongly
Laminated
Shale
Thin section photomicrographs
(Slatt and others, 2011)
Disposal of Fluids from Fracking
Wastewater well
adapted from
geology.com
Fracking well
deep injection may trigger
earthquakes due to stress
relief on faults
Water (brine)
injection depths
are usually deep,
in rocks naturally
stressed with
faults capable of
generating
earthquakes
Induced Seismicity and Enhanced Recovery
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Below a few kilometers depth, the Earth’s crust is everywhere
stressed. Those natural stresses put faults close to failure.
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The injection, which forces fluid along faults and fractures relieves
the effective stress, making triggered earthquakes more likely
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The formation of new fractures –i.e. the hydrofrac itself, actually
doesn’t release much energy compared to the triggered quakes.
But large volumes of fluid are injected during disposal, which flow
along fault, and may trigger earthquakes
Drinking Water Aquifers vs Fracture
Heights of Marcellus Shale
Chemical Classes Used
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AcidsBiocides
Breakers
Clay Stabilizers
Corrosion Inhibitors
Crosslinker
Friction Reducers
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Gelling Agents
Iron Control Agents
Non-Emulsifiers
pH Adjusting Agents
Scale Inhibitors
Surfactants
Fracking Chemicals
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Most companies will not divulge exact
chemicals since it is protected as
“proprietary mixtures”
They are supposed to give info to treating
physicians when requested, to treat an
exposed patient
While there may be 100’s of chemicals
possibly used, each individual site will
typically use 10 or less
Acids
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Hydrochloric acid (muriatic acid) and Acetic
Acid
– Dilute acid solutions used during the initial
fracturing sequence.
– Cleans out cement and debris around the
perforations
– Facilitates the subsequent slickwater solutions
employed in fracturing the formation
– Also used to adjust pH when needed
Biocides
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Used to prevent the growth of bacteria in the
water that may interfere with the fracturing
operation- by causing corrosion
Inhibits sulfate-reducing bacteria from forming
H 2S
Typical Biocides- can have irritant/burns on tissue
exposure
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Glutaraldehyde
Quaternary Ammonium Chloride
Tetrakis Hydroxymethyl-Phosphonium Sulfate
Bromine-based solutions
Biocides- Toxicity
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Glutaraldehyde- sterilant for endoscopy
equipment
Quaternary Ammonium Chloride- common
disinfectant
Tetrakis Hydroxymethyl-Phosphonium
Sulfate- also used in flame retardants,
fabric treatments
Bromine-based solutions- also used in hot
tubs and pools
Breakers
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Used to stabilize and prevent breakdown of
gel- to keep proppants in suspension
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Ammonium Persulfate
Sodium Chloride
Magnesium Peroxide
Magnesium Oxide
Calcium Chloride
Breakers- Toxicity
Ammonium Persulfate- strong oxidizercaustic (used as catalyst for
polyacrylamide)
 Sodium Chloride
 Magnesium Peroxide- oxygen generator;
also used to reduce contaminant levels
in groundwater
 Magnesium Oxide
 Calcium Chloride
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Clay Stabilizers
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Used to stabilize clay and prevent it from
swelling and shifting during drilling operations
– Choline Chloride
– Tetramethyl ammonium chloride
– Sodium Chloride
Clay Stabilizers- Toxicity
Choline Chloride- therapeutic med
 Tetramethyl ammonium chloride Sodium Chloride- table salt
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Corrosion Inhibitors
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Used to prevent corrosion of steel well bore
– Isopropanol
– Methanol
– Formic
– Acetaldehyde
Corrosion Inhibitors- Toxicity
Isopropanol- rubbing alcohol; bitter
taste, metabolized to acetone
 Methanol- wood alcohol, poisonous
when ingested- metabolic acidosis,
retinal, CNS toxicity
 Formic Acid- toxic metabolite of
methanol, responsible for acidosis and
toxicity of methanol
 Acetaldehyde- metabolite of ethanol
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Cross-linking Agents
 Maintains
fracking fluid viscosity at
high temperatures
– Potassium Metaborate
– Triethanolamine Zirconate
– Sodium Tetraborate
– Boric Acid
– Zirconium Complex
– Borate Salts
Borate Salts- toxicity
Irritants at high concentrations
 Oral ingestions cause N/V/D
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– Stools can be blue-green
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Significant ingestions cause
erythrodermic rash
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Boiled Lobster skin
Desquamation
Cross-linking Agents
 Carrier
fluids to deliver cross-linkers
– Petroleum Distillate
– Hydrotreated Light Petroleum Distillate
 Crosslink
stabilizer
– Ethylene Glycol
– Methanol
Friction-Reducing Agents
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Reduces friction of water as it flows –
“slicks”
– Polyacrylamide
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Carrier fluids to deliver polyacrylamide
– Petroleum Distillate
– Hydrotreated Light Petroleum Distillate
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Crosslink stabilizer & winterizer
– Methanol
– Ethylene Glycol
Toxicity of Friction-Reducing
Agents
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Polyacrylamide– also used in water treatments, grouting
– acrylamide monomer is a neurotoxin
– Peripheral neuropathy
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Carrier fluids
– Petroleum Distillate- liquid hydrocarbon
– Hydrotreated Light Petroleum Distillate
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Crosslink stabilizer & winterizer
– Methanol
– Ethylene Glycol
Gelling Agents
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Thickens water so sand will remain in
suspension
– Guar Gum- also thickener in ice cream
– Polysaccharide Blend- Carboxymethyl
Hydroxypropyl Guar
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Carrier fluids for guar gum in liquid gels
– Petroleum Distillate- liquid hydrocarbon
– Hydrotreated Light Petroleum Distillate
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Product stabilizer & winterizer
– Methanol- metabolic acidosis; retinal and CNS toxin
– Ethylene Glycol- metabolic acidosis, nephrotoxin
Toxicity of Gelling Agents
Guar Gum- common food ingredient
thickener in ice cream
 Polysaccharide Blend- Carboxymethyl
Hydroxypropyl Guar
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Iron Control Agents Prevent
oxides
precipitation of metallic
– Citric Acid- food additive
– Acetic Acid- food additive
– Sodium Erythorbate- food additive
– Thioglycolic Acid- irritant, permanent wave
soln
Iron Control Agents- Toxicity
 Organic
acids- much like CalciumLime-Rust (CLR) removing agents
– Citric Acid- food additive
– Acetic Acid- food additive
– Sodium Erythorbate- food additive
– Thioglycolic Acid- irritant, permanent wave
soln
Emulsifier Reducers
 Prevent
formation of emulsions of
the different components of fluids– Lauryl Sulfate- surfactant found in
shampoos, detergents
 Product
stabilizer & winterizer
– Isopropanol- rubbing alcohol
– Ethylene Glycol- metabolic acidosis,
nephrotoxin
Emulsifier Reducers- Toxicity
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Lauryl Sulfate- surfactant found in
numerous consumer products:
shampoos, detergents, etc.
 Product
stabilizer & winterizer
– Isopropanol- rubbing alcohol
– Ethylene Glycol- metabolic acidosis,
nephrotoxin
pH Adjusters
 Added
to adjust pH of water to
enhance properties of crosslinkers
– Sodium Hydroxide
– Potassium Hydroxide
– Acetic Acid
– Sodium Carbonate
– Potassium Carbonate
pH Adjusters- Toxicity
Sodium Hydroxide- Lye- caustic burns on
skin, mucosa when ingested
 Potassium Hydroxide- strong alkali
caustic burns
 Acetic Acid- organic acid- caustic
 Sodium Carbonate- aka soda ashcaustic
 Potassium Carbonate- aka potash-caustic
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Scale Inhibitors
 Prevents
scale deposits in pipes
– Copolymer of Acrylamide and Sodium
Acrylate
– Sodium Polycarboxylate
– Phosphonic Acid Salt
Scale Inhibitors- Toxicity
Copolymer of Acrylamide and Sodium
Acrylate- hygroscopic ingredient of
consumer products like cosmetic creams
 Sodium Polycarboxylate- common
detergent ingredient; HERA safe
detergent additive
 Phosphonic Acid Salt- HERA safe
detergent additive
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Surfactants
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Used to increase viscosity of fracture
fluids
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Lauryl Sulfate
Carrier fluid for surfactant ingredients
– Petroleum naphtha
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Product stabilzers/winterizing agents
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Ethanol
Methanol
Isopropyl Alcohol
2-Butoxyethanol
Surfactants- Toxicity
Lauryl Sulfate- common household
ingredient: shampoos, soaps
 Petroleum naphtha- hydrocarbon liquid
 2-Butoxyethanol- ethylene glycol monobutyl ether- common cleaning agent
 Ethanol
 Methanol
 Isopropyl Alcohol
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BTEX
VOCs commonly produced by oil and
natural gas wells
 Methane most common
 BTEX
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Benzene- AML
Toluene- CNS, RTA,
leukoenecephalopathy in sniffers
Ethylbenzene- CNS
Xylene- CNS
BTEX
“… waters from gas production have
higher contents of… BTEX than those
from oil operations; … waters discharged
from gas/condensate platforms are
about 10 times more toxic than from oil
platforms.
Argonne National Laboratory (pdf)
BTEX
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Benzene- AML, aplastic anemia
Toluene- CNS depression, RTA,
leukoenecephalopathy in sniffers
Ethylbenzene- CNS depression
Xylene- CNS depression
Methane Simple asphyxiant
WEB--‐BASED RESOURCES FOR INFORMATION REGARDING THE REGULATION AND HEALTH/ENVIRONMENTAL
IMPACTS OF HYDRAULIC FRACTURING - Governmental Websites
Governmental Agencies
USEPA Hydraulic Fracturing Website
Al things related to hydraulic fracturing, Including EPA’s
studies and proposed regulations.
http://www.epa.gov/hydraulicfracture/
Pennsylvania Marcellus
Shale Page
State regulations, well
Permits and locations
http://www.portal.state.pa.us/portal/server.pt/co
mmunity/marcellus_shale/20296
COGCC Website
Comprehensive source of
Information regarding hydraulic fracturing in
Colorado. Includes regulations, results of
Environmental studies, and
Informational materials.
http://cogcc.state.co.us
COGCC HF Information Page
Provides many links to informational websites on
HF
http://cogcc.state.co.us/Announcements/Hot_Topi
cs/Hydraulic_Fracturing/Hydra_Frac_topics.html
TCEQ Resources for
Public Address
Provides air quality information
http://www.tceq.texas.gov/agency/public_main.ht
ml
Fayetteville Shale
Homepage
Provides information regarding regulatory standards In
the State of Arkansas.
http://www.aogc.state.ar.us/Fay_Shale_Data.htm
Arkansas Well Fracture Information
Permits and chemical listings for proposed wells
To be fracture stimulated.
http://www.aogc.state.ar.us/Well_Fracture_Compa
nies.htm
USGS State of the Science Briefing
Contains links to PowerPoint presentations
To Congress– general information regarding hydraulic
fracturing.
http://www.usgs.gov/solutions/2012_june8.html
US Energy Information
Administration
General hydraulic fracturing information,
economics, production
http://www.eia.gov/energy_in_brief/about_shale_
gas.cfm
State of New York
Environmental Impact
Statement
The State of New York’s
Environmental impact
Statement regarding proposed hydraulic fracturing
operations
http://www.dec.ny.gov/energy/75370.html
WEB--‐BASED RESOURCES FOR INFORMATION REGARDING THE REGULATION AND HEALTH/ENVIRONMENTAL
IMPACTS OF HYDRAULIC FRACTURING
Industry Websites
Description
Web Address
FracFocus
All things fracking: General
information, chemical registry,
well maps, regulations,etc.…
http://fracfocus.org
Southwestern
Energy
General information
regarding each operations area,
as
well as environmental
initiatives
http://www.swn.com/operations/
Pages/areas.asp
x
HydraulicFracturing.com
Wide--‐ranging
Information regarding hydraulic
fracturing
And regulations
http://www.hydraulicfracturing.co
m/Pages/infor
mation.aspx
Halliburton
General process
information
http://www.halliburton.com/publi
c/projects/pub
sdata/hydraulic_fracturing/fracturi
ng_101.html
API Policy Issues
Policy information
http://www.api.org/policy--‐and-‐issues/hf.aspx
WEB--‐BASED RESOURCES FOR INFORMATION REGARDING THE REGULATION AND
HEALTH/ENVIRONMENTAL IMPACTS OF HYDRAULIC FRACTURING
NGO Websites
Organization
Descritpion
Web address
Earthworks
General information,
Groundwater, activism
http://www.earthworksaction.o
rg/issues/detail/h
ydraulic_fracturing_101
National Resources Defense
Council (NRDC)
Anti--‐fracking blog posts and
News stories
http://www.nrdc.org
Sierra Club
General information, activism
http://content.sierraclub.org/n
aturalgas/
Greenpeace
General information, activism
http://www.greenpeace.org/us
a/en/campaigns/gl
obal--‐warming--‐and-‐energy/The-‐Problem/fracking/
Environmental Working
Group
General information, activism
http://www.ewg.org/gas-‐drilling--‐and--‐fracking