Tuesday, June 10, 2008

Colorado's Chemical Injection

Oil and gas companies in Colorado are injecting wells with millions of gallons of unknown fluids that contain dozens of dangerous chemicals linked to respiratory, neurological, cardiovascular, immune, and other disorders, including cancer.

According to industry data, at least 430 million gallons of chemical-laced fluids have been injected into more than 9,000 oil and gas wells in the state, mostly along the northern Front Range and the Western Slope. The amount of fluid injected may be far greater than reported: There are currently more than 35,000 wells operating in Colorado and one industry expert has estimated that 90 percent of all wells receive chemical injections (COGCC 2008, Carrillo 2005).

Locations of Wells Receiving Chemical Injections

Locations of Wells Receiving Chemical Injections

Source: IHS Energy (IHS). 2008. PI/Dwights Plus Energy Well Data, Rocky Mountain, Volume 18, Issue 5, Released May 1, 2008.

The analysis by Environmental Working Group and The Endocrine Disruption Exchange (TEDX), a research organization based in Paonia, Colo., found that at least 65 chemicals used by natural gas companies in Colorado are listed as hazardous under 6 major federal laws designed to protect Americans from toxic substances. If any one of these 65 chemicals were emitted or discharged from an industrial facility, reporting to the US EPA would be mandatory, and in most cases permits would require strict pollution limits and companies would be subject to specific cleanup standards. But because these same chemicals are used in natural gas drilling operations they are completely exempt from environmental reporting requirements, and their use is not controlled in any meaningful way.

While energy companies use toxic chemicals for a variety of purposes and can extract toxic materials as byproducts of the drilling process, the injection of toxic chemicals underground raises particular concern because of the risk of contaminating drinking water sources. Chemicals are typically injected in processes called "hydraulic fracturing" or "acidizing" that are used to increase oil and gas production. Because neither state nor federal law regulates such injections, or even requires companies to report the chemicals they use, the practice raises serious concerns about toxic chemicals leaching into water and soil.

Our analysis also identified more than 150 other chemicals or chemical mixes used in these operations that are not regulated by these 6 major environmental laws. The fact that these chemical products are not listed under the 6 laws does not mean that they are safe -- it simply reveals the magnitude of the shortcomings in these federal laws when it comes to protecting the environment and human health from chemicals used in oil and gas drilling operations.

Despite a record number of wells approved in Colorado -- more than 6,300 in 2007 versus just 2,900 in 2004 -- state and federal officials and the public have almost no idea how any of these industry chemicals are used, whether or not their use threatens water supplies, pollutes the local air, or presents a risk to public safety. This is true even when these chemicals are considered highly toxic, or an "imminent and substantial danger" to health and the environment under federal environmental laws. Dozens of pesticide ingredients are also used by the natural gas industry in Colorado.

These findings are released as Colorado's Oil and Gas Conservation Commission prepares to hold its latest hearing, June 10 in Grand Junction, as part of a landmark process to rewrite the state's drilling standards. Among the protections that the Commission is considering is a requirement that companies provide limited disclosure of the chemicals they use. But limited disclosure is not enough to ensure protection of public health and the environment. This analysis clearly shows that comprehensive reporting and public disclosure of all chemicals used in oil and gas operations is a mandatory first step toward understanding the magnitude of the environmental and health threat, if any, that may be posed by these operations.

Wells Receiving Chemical Injections in Colorado by County

 

COLORADO COUNTY WELLS
Weld 3019
La Plata 754
Rio Blanco 710
Adams 537
Garfield 457
Morgan 343
Mesa 336
Moffat 332
Baca 261
Logan 237
Washington 234
Cheyenne 184
Arapahoe 181
Kiowa 176
Yuma 166
Montezuma 117
Las Animas 100
Larimer 96
Elbert 85
Boulder 57
Jackson 47
Prowers 46
Routt 45
Archuleta 41
San Miguel 38
Bent 27
Dolores 27
Huerfano 27
Denver 22
Broomfield 18
Lincoln 18
Kit Carson 16
Delta 13
Gunnison 13
Fremont 12
Pitkin 10
Jefferson 5
Montrose 5
Phillips 3
El Paso 2
Grand 2
Rio Grande 2
Sedgwick 2
Crowley 1
Park 1
Pueblo 1
Washington 1

Source: IHS Energy (IHS). 2008. PI/Dwights Plus Energy Well Data, Rocky Mountain, Volume 18, Issue 5, Released May 1, 2008.

 

Underground Contamination Risks

A 2005 report by the Durango-based Oil and Gas Accountability Project (OGAP) found that fluids injected underground in hydraulic fracturing operations have been linked to a variety of health problems including respiratory illness, cancer and birth defects. In hydraulic fracturing, companies inject fluid under high pressure to break open rock formations allowing more natural gas or oil to flow up the drilling tube. Companies also inject acid to dissolve the rock to increase the flow of natural gas or oil -- a process known as "acidizing" or, if the acid is injected under high pressure to fracture the rock, "acid fracturing." In addition, companies inject "proppants" such as sand to prevent the fracture from closing (Oilfield Review 1995, OGAP 2005).

OGAP found that a draft EPA study showed that even when diluted with water, companies may inject at least nine fracturing chemicals into underground drinking water sources at concentrations that pose risks to human health: aromatics, benzene, ethylene glycol, fluorenes, methanol, 1-methylnapthalene, 2-methylnapthalene, naphthalene and phenanthrenes. The EPA removed this information from its final study released in 2004 which found that fracturing "poses little or no threat" to drinking water. An EPA insider and others subsequently criticized the study's accuracy. OGAP also found that one fracturing company, Schlumberger, recommends that many of its fracturing fluids be disposed of at hazardous waste facilities (OGAP 2005).

In the Energy Policy Act of 2005, Congress exempted the practice of hydraulic fracturing from the Safe Drinking Water Act. The oil and gas industry is the nation's only industry that is allowed to inject hazardous substances unchecked directly into, or directly adjacent to, underground drinking water sources (OGAP 2005, Hartman 2007).

The use of large volumes of injection fluids also raises questions about whether the water required for such injections may exhaust scarce water supplies in Colorado and other western states.

Hundreds of Millions of Gallons Injected

According to records from Englewood-based IHS Energy, Delta Petroleum Corp. injected a natural gas well in Mesa County with one of the highest volumes of fluid in the state. Between April 14, 2007 when Delta drilled the well and November 6, 2007 when drilling was completed, the Denver-based company injected the well with 1.4 million gallons of unknown fluids and acid and 361 tons of sand (IHS 2008).

The records also show that between February 3, 2004 and June 28, 2004, Canada-based Encana injected a natural gas well in Garfield County with 1 million gallons of fluid and 454 tons of sand (IHS 2008).

The numbers are consistent with a 1995 report from the industry publication, Oilfield Review, which found that companies can inject wells with as many as 1 million gallons of fluid and 1,500 tons of proppants such as sand (Oilfield Review 1995). Victor Carrillo, a representative for the Interstate Oil and Gas Compact Commission, told Congress in 2005 that 90 percent of the United States' oil and gas wells are fractured (Carrillo 2005).

Overall, the IHS records show that there are 9,037 wells in Colorado that received 431.7 million gallons of treatments with fluids. Most of the treatments are listed as fracturing or acid treatments (IHS 2008). These figures likely understate the total number of wells treated and the gallons of fluid used.

Drilling Chemicals Listed under 6 Federal Laws

Percent of 65 chemicals associated with adverse health effects.

Bar chart showing health effects of chemicals

 

Source: The Endocrine Disruption Exchange 2008 Analysis of Chemicals Found on National Toxics Lists for Colorado, unpublished.

 

65 Colorado Natural Gas Industry Chemicals Listed Under Six Federal Pollution Protection Laws

(2-BE) Ethylene glycol monobutyl ether
1-methoxy-2-propanol
2-(2-Methoxyethoxy)ethanol
2,2',2"-Nitrilotriethanol
Diethylene glycol
Diethylene glycol monobutyl ether
Formamide
Glutaraldehyde
Glycerin Mist (glycerol)
Glyoxal
Monoethanolamine
Monopentaerythritol
Hydrofluoric Acid
Hydrochloric Acid (HCl)
Ethylene oxide
Acetic acid
Fumaric Acid
Naphthalene
Xylene
Formic acid
Benzyl chloride
Ethyl benzene
Styrene
Methanol
Acrylamide
Dimethyl formamide
Ethylene glycol
Adipic Acid
Ammonium bisulfite
Chromium acetate
Dodecylbenzene sulfonic acid
Ferrous sulfate
Potassium hydroxide
Zinc Carbonate
Zirconium nitrate
Zirconium sulfate
Sodium hydroxide
Isobutyl alcohol (2-methyl-1-propanol)
Butanol (N-butyl alcohol, Butan-1-OL)
Thiourea
Mercury
Nickel
Lead
Antimony
Arsenic
Cadmium
Chromium
Copper
Zinc
Propargyl alcohol (Prop-2-YN-1-OL
Calcium hydroxide
Calcium oxide
Ethanol (Acetylenic alcohol)
Fluoride
Cobalt
Barium
Isopropanol (Propan-2-OL)
Vanadium
2-(Thiocyanomethylthio) benzothiazole (TCMTB)
1,2-Bromo-2-nitropropane-1,3-Diol (2-Bromo-2-nitro-1,3-propanediol or Bronopol)
2,2-Dibromo-3-Nitrilopropionamide (DBNPA)
Aluminum Oxide
Barite (BaSO4)
Sodium sulfate
Tetrahydro-3,5-dimethyl-2H-1,3,5- thiadiazine-2-thione (Dazomet)

Source: The Endocrine Disruption Exchange 2008 Analysis of Chemicals Used in Colorado Natural Gas Drilling Operations; Environmental Working Group Analysis of CAA, CWA, CERCLA, EPCRA, RCRA, and SARA.

At least 65 chemicals used by oil and gas companies in Colorado -- including at least some used for chemical injections -- are listed as hazardous under sections of the Clean Air Act, Clean Water Act, Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), Emergency Planning and Community Right-to-Know Act (EPCRA), Resource Conservation and Recovery Act (RCRA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA).

The chemicals are associated with a range of health effects from skin and eye irritation to nervous system and brain problems. Of those chemicals that appear on the federal toxic lists 95 percent can cause skin, eye, and sensory reactions; 90 percent have respiratory effects that include asthma, sore throats, and chronic sinus and upper and lower respiratory infections; 75 percent affect the nervous system, causing headaches, unexplained tingling, numbness and pain in the extremeties, blackouts, and convulsions; more than 70 percent can cause more long-term effects such as cardiovascular, kidney and immune system disorders; and approximately 45 percent are associated with cancer.

The Endocrine Disruption Exchange identified the chemicals and other substances used in oil and gas drilling through Tier II reports that companies are required to file with emergency first responders under EPCRA; Material Safety Data Sheets (MSDS) that companies are required to file with first responders by the Occupational Safety and Health Administration (OSHA), environmental impact statements written by the Bureau of Land Management and Forest Service; and accident reports completed by first responders (TEDX 2008).

While these data sources provide a glimpse of the chemicals used by energy companies, the sources are incomplete. Companies sometimes list names of products described in general terms such as "plasticizer" or "crosslinker." Data on the products' chemical ingredients is often missing. Sometimes product labels state "proprietary." The documents do not reveal -- nor are they designed to reveal -- what volumes or concentrations of the chemicals are used in the drilling and fracturing process. The MSDSs are designed to protect employees and first responders in the case of an accident and focus on acute exposure, but the information on the sheets often does not reflect the health impacts from long-term exposure.

 

Legislation

Clean Air Act

Twenty-seven chemicals used by the oil and gas industry in Colorado were listed as hazardous pollutants under three sections of the Clean Air Act. The Act, passed in 1970 and amended in 1990, protects Americans from a wide array of air pollution. The Act: (1) requires the use of technologies to control release of hazardous pollutants, (2) requires facilities to establish an emergency management plan for dangerous pollutants, and (3) controls pollutants likely to endanger public health.

The oil and gas industry enjoys an important exemption under the Clean Air Act. The drilling sites are not treated as an aggregated unit for measuring air pollutants, and therefore the relatively small emissions from each individual unit are deemed negligible. An extensive report by the Oil and Gas Accountability Project analyzes important exemptions for the oil and gas industry under a variety of statutes, including the Clean Air Act (OGAP 2007).

Clean Water Act

Twenty-two chemicals used by the oil and gas industry were listed as pollutants that when discharged into navigable waters pose an "imminent and substantial danger to the public health or welfare" under the Clean Water Act. The Act, passed in 1972, protects citizens from a variety of sources of water pollution.

The oil and gas industry is exempted from obtaining a permit for stormwater runoff discharges under the Clean Water Act. The numerous chemicals stored onsite and used in the production process by this industry raises an enormous concern regarding water quality, particularly discharges via surface runoff (OGAP 2007).

Resource Conservation and Recovery Act

Eleven of the 65 chemicals used by the oil and gas industry were listed as hazardous wastes when disposed of unused by the Resource Conservation and Recovery Act (RCRA). The Act, passed in 1976, is designed to protect human health and the environment from the potential hazards of waste disposal.

The oil and gas industry is exempt under RCRA, which protects citizens from wastes classified as hazardous. This provision exempts the industry from managing hazardous wastes in an environmentally responsible manner (OGAP 2007).

Comprehensive Environmental Response Compensation and Liability Act

We found that 40 of the 65 chemicals used by the oil and gas industry are listed as hazardous by the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) of 1980, commonly known as Superfund. The act is designed to allow the federal government to respond to releases of hazardous substances that constitute a threat to human health or the environment. The act levies a tax on the chemical and petroleum industries which is to be used to clean up contaminated sites.

Superfund exempts petroleum and crude oil from its list of chemicals, providing a significant escape hatch to the oil and gas industry (OGAP 2007).

Superfund Amendments and Reauthorization Act (SARA)

We found that 30 of the 65 chemicals used by the oil and gas industry are listed under - the Superfund Amendments and Reauthorization Act (SARA). The act amended CERCLA in 1986. Among numerous changes it enacted, SARA increased the size of the superfund and provided a greater focus on human health concerns raised by the growing number of contaminants polluting the environment. Section 110 lists chemicals that pose the greatest threat to human health while section 302(a) lists extremely hazardous substances that require cooperative plans between companies and local emergency planning committees to prepare for spills or releases.

Toxics Release Inventory (TRI)

Thirty-six of the 65 chemicals used by the oil and gas industry are required to be reported by other industries -- but not by oil and gas producers -- under the Toxics Release Inventory (TRI). The TRI is part of the nation's premier right-to-know law, the Emergency Planning and Community Right-to-Know Act (EPCRA), and requires the reporting of dangerous chemicals when used in amounts above certain thresholds.

Yet the TRI exempts oil and gas companies from reporting requirements, and there are no state requirements for oil and gas companies to report the chemicals they use. If the companies were required to report their chemicals under the TRI, the names of the chemicals would be made available to the public (CFR TRI SIC Codes 2008).

See Appendix A for a list of oil and gas industry chemicals under each statute.

 

Public Right to Know

The Public Has a Right To Know what Chemicals are Used

Currently, the Colorado Oil and Gas Conservation Commission is drafting state drilling standards that would require oil and gas companies to keep an inventory of all chemicals "by chemical name, used, stored, or released" in the drilling process. The inventory would include "how much of each chemical was used, how it was used, and when it was used."

While this requirement would be a major step forward, the proposed rule should be strengthened by requiring companies to list "specific volumes and concentrations" of chemicals used rather than simply "how much" of the chemicals they use (OGAP Proposed Changes 2008).

In addition, the draft rules do not specify that the public can access the chemical inventory, only that companies must keep it "in a readily retrievable and reviewable format" and that "the Colorado Department of Public Health and Environment may obtain information provided to the [Colorado Oil and Gas Conservation] Commission in a chemical inventory upon written request to the Commission."

The rules should be changed to require the companies to make public the chemicals they are using through the Commission's web site and through local first responders to increase public knowledge and for immediate access in the case of accidents or spills.

Colorado should follow the example of Klickitat County in Washington State that recently required a natural gas company that drills in Colorado to disclose the chemicals the company would use before drilling in Klickitat County. The county also required the company, Denver-based Delta Petroleum, to give local officials three days advance notice before adding new chemicals to its operations. This type of advance notice should be a model for Colorado. Under the agreement, Delta Petroleum provided a list of 76 substances to Klickitat county, some of which appear to be product names rather than more informative chemical ingredients of the products. (Download chemical page from agreement betwen Klickitat County and Delta Energy [PDF], or the entire document [PDF].)

The state should also have the ability to prohibit the use of any chemicals used in drilling -- a right that the Klickitat County planning department has under the agreement with Delta. Among the prohibited substances is 2-BE, also known as 2-butoxyethanol or ethelyne glycol monobutyl ether, a chemical found in at least 6 products used by natural gas companies in Colorado.

 

Appendix

Number of 65 Chemicals Used by Colorado Natural Gas Industry Listed Under 6 Federal Pollution Protection Laws

Clean Air Act: 27 chemicals listed under §112(b)(1), §112(r), §202(a)

 

 

  • (2-BE) Ethylene glycol monobutyl ether
  • 1-methoxy-2-propanol
  • 2-(2-Methoxyethoxy)ethanol
  • 2,2',2"-Nitrilotriethanol
  • Acetic acid
  • Acrylamide
  • Benzyl chloride
  • Diethylene glycol
  • Diethylene glycol monobutyl ether
  • Dimethyl formamide
  • Ethyl benzene
  • Ethylene glycol
  • Ethylene oxide
  • Formamide
  • Formic acid
  • Fumaric Acid
  • Glutaraldehyde
  • Glycerin Mist (glycerol)
  • Glyoxal
  • Hydrochloric Acid (HCl)
  • Hydrofluoric Acid
  • Methanol
  • Monoethanolamine
  • Monopentaerythritol
  • Naphthalene
  • Styrene
  • Xylene

Clean Water Act: 22 chemicals listed under §311(b)(2)(A)

  • Acetic acid
  • Adipic Acid
  • Ammonium bisulfite
  • Benzyl chloride
  • Calcium hydroxide
  • Calcium oxide
  • Chromium acetate
  • Dodecylbenzene sulfonic acid
  • Ethyl benzene
  • Ferrous sulfate
  • Formic acid
  • Fumaric Acid
  • Hydrochloric Acid (HCl)
  • Hydrofluoric Acid
  • Naphthalene
  • Potassium hydroxide
  • Sodium hydroxide
  • Styrene
  • Xylene
  • Zinc Carbonate
  • Zirconium nitrate
  • Zirconium sulfate

Comprehensive Environmental Response Compensation and Liability Act (Superfund), 40 chemicals listed under 40 CFR 302.4:

  • Acetic acid
  • Acrylamide
  • Adipic Acid
  • Ammonium bisulfite
  • Antimony
  • Arsenic
  • Barium
  • Benzyl chloride
  • Butanol (N-butyl alcohol, Butan-1-OL)
  • Cadmium
  • Chromium
  • Cobalt
  • Copper
  • Dimethyl formamide
  • Dodecylbenzene sulfonic acid
  • Ethyl benzene
  • Ethylene glycol
  • Ethylene oxide
  • Ferrous sulfate
  • Formic acid
  • Fumaric Acid
  • Hydrochloric Acid (HCl)
  • Hydrofluoric Acid
  • Isobutyl alcohol (2-methyl-1-propanol)
  • Lead
  • Mercury
  • Methanol
  • Naphthalene
  • Nickel
  • Potassium hydroxide
  • Propargyl alcohol (Prop-2-YN-1-OL
  • Sodium hydroxide
  • Styrene
  • Thiourea
  • Vanadium
  • Xylene
  • Zinc
  • Zinc Carbonate
  • Zirconium nitrate
  • Zirconium sulfate

Resource Conservation and Recovery Act: 11 chemicals listed

  • Acrylamide
  • Butanol (N-butyl alcohol, Butan-1-OL)
  • Ethylene oxide
  • Formic acid
  • Hydrofluoric Acid
  • Isobutyl alcohol (2-methyl-1-propanol)
  • Mercury
  • Methanol
  • Naphthalene
  • Thiourea
  • Xylene

Superfund Amendments and Reauthorization Act: 30 chemicals listed under §110, §302(A)

  • 2-(Thiocyanomethylthio) benzothiazole (TCMTB)
  • Acrylamide
  • Antimony
  • Arsenic
  • Barium
  • Benzyl chloride
  • Butanol (N-butyl alcohol, Butan-1-OL)
  • Cadmium
  • Chromium
  • Cobalt
  • Copper
  • Dimethyl formamide
  • Ethanol (Acetylenic alcohol)
  • Ethyl benzene
  • Ethylene glycol
  • Ethylene oxide
  • Fluoride
  • Hydrochloric Acid (HCl)
  • Hydrofluoric Acid
  • Isopropanol (Propan-2-OL)
  • Lead
  • Mercury
  • Methanol
  • Naphthalene
  • Nickel
  • Styrene
  • Thiourea
  • Vanadium
  • Xylene
  • Zinc

Toxics Release Inventory: 36 chemicals listed

  • 1,2-Bromo-2-nitropropane-1,3-Diol (2-Bromo-2-nitro-1,3-propanediol or Bronopol)
  • 2,2-Dibromo-3-Nitrilopropionamide (DBNPA)
  • Acrylamide
  • Aluminum Oxide
  • Antimony
  • Arsenic
  • Barite (BaSO4)
  • Barium
  • Benzyl chloride
  • Butanol (N-butyl alcohol, Butan-1-OL)
  • Cadmium
  • Chromium
  • Cobalt
  • Copper
  • Dimethyl formamide
  • Ethyl benzene
  • Ethylene glycol
  • Ethylene oxide
  • Formic acid
  • Hydrochloric Acid (HCl)
  • Hydrofluoric Acid
  • Isopropanol (Propan-2-OL)
  • Lead
  • Mercury
  • Methanol
  • Naphthalene
  • Nickel
  • Propargyl alcohol (Prop-2-YN-1-OL
  • Sodium hydroxide
  • Sodium sulfate
  • Styrene
  • Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione (Dazomet)
  • Thiourea
  • Vanadium
  • Xylene
  • Zinc

 

 

References: 

Carrillo, Victor (Carrillo). 2005. Testimony submitted to the House Committee on Energy and Commerce by Victor Carrillo, Chairman, Texas Railroad Commission Representing the Interstate Oil and Gas Compact Commission, February 10, 2005. Accessed online June 4, 2005 at http://www.rrc.state.tx.us/commissioners/carrillo/press/ energytestimony.html.

Code of Federal Regulations (CFR TRI SIC Codes). 2008. 40 CFR 372.23 (2008). The standard provides that industries classified by certain Standard Industrial Classification (SIC) Codes must adhere to reporting requirements as provided in 42 USCS 11023. "Major Group 13: Oil and Gas Extraction" is not one of the SIC groups included. See U.S. Department of Labor, Occupational Safety and Health Administration, Major Group 13: Oil and Gas Extraction, accessed online May 28, 2008 at http://www.osha.gov/pls/imis/sic_manual.display?id=8&tab=group.

Colorado Oil and Gas Conservation Commission (COGCC). 2008. Colorado Weekly and Monthly Oil and Gas Statistics, 5-5-08. Accessed online June 6, 2008 at http://www.oil-gas.state.co.us/. Environmental Protection Agency (EPA TRI). 2008. TRI (Toxics Release Inventory) Explorer. Accessed online May 29, 2008 at http://www.epa.gov/triexplorer/.

IHS Energy (IHS). 2008. PI/Dwights Plus Energy Well Data, Rocky Mountain, Volume 18, Issue 5, Released May 1, 2008.

Hartman, Todd (Hartman). 2007. Industry Oversight, Rocky Mountain News, December 11, 2007, p. 14.

Kosnik, Renee (Kosnik). 2007. The Oil and Gas Industry's Exclusions and Exemptions to Major Environmental Statutes. The Oil and Gas Accountability Project. Accessed online June 5, 2008 at http://www.earthworksaction.org/pubs/PetroleumExemptions1c.pdf. Oil and Gas Accountability Project (OGAP). 2005.

Our Drinking Water at Risk: What EPA and the Oil and Gas Industry Don't Want Us to Know About Hydraulic Fracturing. Accessed online June 5, 2008 at http://www.earthworksaction.org/pubs/DrinkingWaterAtRisk.pdf.

Oil and Gas Accountability Project (OGAP). 2007. The Oil and Gas Industry's Exclusions and Exemptions to Major Environmental Statutes, October 2007. Accessed online June 6, 2008 at http://www.earthworksaction.org/oil_and_gas.cfm.

Oil and Gas Accountability Project (OGAP Proposed Changes). 2008. Consolidated Final Rulemaking Proposals of the Oil and Gas Accountability Project, San Juan Citizens Alliance and the North Fork Ranch Landowners Ass'n Inc., Before the Oil and Gas Conservation Commission, State of Colorado, May 14, 2008.

Oilfield Review (Oilfield Review). 1995. Advanced Fracturing Fluids Improve Well Economics, Autumn 1995, 34-51.

The Endocrine Disruption Exchange (TEDX). 2008. See www.endocrinedisruption.org under "products."