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Toxicology of Hydraulic Fracturing

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

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Toxicology of Hydraulic Fracturing

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  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

  2. Background of Fracking • 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

  3. Background • 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

  4. Background • Water & its additives are withdrawn (flowback), and contained or recycled or disposed of, depending on permit • Regulated by the National Pollutant Discharge Elimination System (NPDES) • Requires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 ) • Oil or gas is then extracted

  5. Do not drink this water • http://www.youtube.com/v/4ApZkNsXfJE&t=1m

  6. Hydraulic Fracturing Explained http://www.youtube.com/v/YemKzEPugpk

  7. Areas of Concern • 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 • 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

  8. Horizontal Wells

  9. Continuous Reservoir Woodford Shale Weakly Laminated Shale Strongly Laminated Shale Thin section photomicrographs (Slatt and others, 2011)

  10. Disposal of Fluids from Fracking Water (brine) injection depths are usually deep, in rocks naturally stressed with faults capable of generating earthquakes Wastewater well Fracking well adapted from geology.com deep injection may trigger earthquakes due to stress relief on faults

  11. Induced Seismicity and Enhanced Recovery • Below a few kilometers depth, the Earth’s crust is everywhere stressed. Those natural stresses put faults close to failure. • The injection, which forces fluid along faults and fractures relieves the effective stress, making triggered earthquakes more likely • 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

  12. Drinking Water Aquifers vs Fracture Heights of Marcellus Shale

  13. Acids- Biocides Breakers Clay Stabilizers Corrosion Inhibitors Crosslinker Friction Reducers Gelling Agents Iron Control Agents Non-Emulsifiers pH Adjusting Agents Scale Inhibitors Surfactants Chemical Classes Used

  14. 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 Fracking Chemicals

  15. Acids • 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

  16. Biocides • 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 H2S • Typical Biocides- can have irritant/burns on tissue exposure • Glutaraldehyde • Quaternary Ammonium Chloride • TetrakisHydroxymethyl-Phosphonium Sulfate • Bromine-based solutions

  17. Biocides- Toxicity • Glutaraldehyde- sterilant for endoscopy equipment • Quaternary Ammonium Chloride- common disinfectant • TetrakisHydroxymethyl-Phosphonium Sulfate- also used in flame retardants, fabric treatments • Bromine-based solutions- also used in hot tubs and pools

  18. Breakers • Used to stabilize and prevent breakdown of gel- to keep proppants in suspension • Ammonium Persulfate • Sodium Chloride • Magnesium Peroxide • Magnesium Oxide • Calcium Chloride

  19. Breakers- Toxicity • Ammonium Persulfate- strong oxidizer- caustic (used as catalyst for polyacrylamide) • Sodium Chloride • Magnesium Peroxide- oxygen generator; also used to reduce contaminant levels in groundwater • Magnesium Oxide • Calcium Chloride

  20. Clay Stabilizers • Used to stabilize clay and prevent it from swelling and shifting during drilling operations • Choline Chloride • Tetramethyl ammonium chloride • Sodium Chloride

  21. Clay Stabilizers- Toxicity • Choline Chloride- therapeutic med • Tetramethyl ammonium chloride- • Sodium Chloride- table salt

  22. Corrosion Inhibitors • Used to prevent corrosion of steel well bore • Isopropanol • Methanol • Formic • Acetaldehyde

  23. 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

  24. Cross-linking Agents • Maintains fracking fluid viscosity at high temperatures • Potassium Metaborate • TriethanolamineZirconate • Sodium Tetraborate • Boric Acid • Zirconium Complex • Borate Salts

  25. Borate Salts- toxicity • Irritants at high concentrations • Oral ingestions cause N/V/D • Stools can be blue-green • Significant ingestions cause erythrodermic rash • Boiled Lobster skin • Desquamation

  26. Cross-linking Agents • Carrier fluids to deliver cross-linkers • Petroleum Distillate • Hydrotreated Light Petroleum Distillate • Crosslink stabilizer • Ethylene Glycol • Methanol

  27. Friction-Reducing Agents • Reduces friction of water as it flows – “slicks” • Polyacrylamide • Carrier fluids to deliver polyacrylamide • Petroleum Distillate • Hydrotreated Light Petroleum Distillate • Crosslink stabilizer & winterizer • Methanol • Ethylene Glycol

  28. Toxicity of Friction-Reducing Agents • Polyacrylamide- • also used in water treatments, grouting • acrylamide monomer is a neurotoxin • Peripheral neuropathy • Carrier fluids • Petroleum Distillate- liquid hydrocarbon • Hydrotreated Light Petroleum Distillate • Crosslink stabilizer & winterizer • Methanol • Ethylene Glycol

  29. Gelling Agents • Thickens water so sand will remain in suspension • Guar Gum- also thickener in ice cream • Polysaccharide Blend- CarboxymethylHydroxypropyl Guar • Carrier fluids for guar gum in liquid gels • Petroleum Distillate- liquid hydrocarbon • Hydrotreated Light Petroleum Distillate • Product stabilizer & winterizer • Methanol- metabolic acidosis; retinal and CNS toxin • Ethylene Glycol- metabolic acidosis, nephrotoxin

  30. Toxicity of Gelling Agents • Guar Gum- common food ingredient thickener in ice cream • Polysaccharide Blend- CarboxymethylHydroxypropyl Guar

  31. Iron Control Agents- • Prevent precipitation of metallic oxides • Citric Acid- food additive • Acetic Acid- food additive • Sodium Erythorbate- food additive • Thioglycolic Acid- irritant, permanent wave soln

  32. Iron Control Agents- Toxicity • Organic acids- much like Calcium-Lime-Rust (CLR) removing agents • Citric Acid- food additive • Acetic Acid- food additive • Sodium Erythorbate- food additive • Thioglycolic Acid- irritant, permanent wave soln

  33. 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

  34. Emulsifier Reducers- Toxicity • Lauryl Sulfate- surfactant found in numerous consumer products: shampoos, detergents, etc. • Product stabilizer & winterizer • Isopropanol- rubbing alcohol • Ethylene Glycol- metabolic acidosis, nephrotoxin

  35. pH Adjusters • Added to adjust pH of water to enhance properties of crosslinkers • Sodium Hydroxide • Potassium Hydroxide • Acetic Acid • Sodium Carbonate • Potassium Carbonate

  36. 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 ash- caustic • Potassium Carbonate- aka potash-caustic

  37. Scale Inhibitors • Prevents scale deposits in pipes • Copolymer of Acrylamide and Sodium Acrylate • Sodium Polycarboxylate • Phosphonic Acid Salt

  38. 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

  39. Surfactants • Used to increase viscosity of fracture fluids • Lauryl Sulfate • Carrier fluid for surfactant ingredients • Petroleum naphtha • Product stabilzers/winterizing agents • Ethanol • Methanol • Isopropyl Alcohol • 2-Butoxyethanol

  40. Surfactants- Toxicity • Lauryl Sulfate- common household ingredient: shampoos, soaps • Petroleum naphtha- hydrocarbon liquid • 2-Butoxyethanol- ethylene glycol mono-butyl ether- common cleaning agent • Ethanol • Methanol • Isopropyl Alcohol

  41. BTEX • VOCs commonly produced by oil and natural gas wells • Methane most common • BTEX • Benzene- AML • Toluene- CNS, RTA, leukoenecephalopathy in sniffers • Ethylbenzene- CNS • Xylene- CNS

  42. 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)

  43. BTEX • Benzene- AML, aplastic anemia • Toluene- CNS depression, RTA, leukoenecephalopathy in sniffers • Ethylbenzene- CNS depression • Xylene- CNS depression • Methane Simple asphyxiant

  44. WEB--‐BASED RESOURCES FOR INFORMATION REGARDING THE REGULATION AND HEALTH/ENVIRONMENTAL IMPACTS OF HYDRAULIC FRACTURING - Governmental Websites

  45. WEB--‐BASED RESOURCES FOR INFORMATION REGARDING THE REGULATION AND HEALTH/ENVIRONMENTAL IMPACTS OF HYDRAULIC FRACTURING Industry Websites

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