Full Title: California’s Fracking Fluids: The Chemical Recipe
Author(s): Tasha Stoiber, Bill Walker, and Bill Allayaud
Publisher(s): Environmental Working Group
Publication Date: 08/2015


Description (excerpt):

The fluids used in hydraulic fracturing of oil wells in California contain dozens of chemicals that are hazardous to human health, including substances linked to cancer, reproductive harm and hormone disruption, an EWG analysis of state data shows. Under a 2013 California law (SB 4) requiring disclosure of all chemicals used to boost production from oil wells by fracking or similar methods, drilling companies reported using 197 unique chemicals in 691 oil wells from December 2013 through February 2015. The fracking fluids typically contained two dozen or more different chemicals. EWG’s analysis found that they included:

• 15 listed under California’s Proposition 65 as known causes of cancer or reproductive harm
• 25 likely to contain impurities of Proposition 65-listed chemicals
• 5 that the European Union has associated with an increased risk of cancer
• 6 associated with reproductive harm
• 3 linked to clear evidence of hormone disruption
• 12 listed under the federal Clean Air Act as Hazardous Air Pollutants known to cause cancer or other harm
• 93 associated with harm to aquatic life.

1 The 197 chemicals were compared to an EWG database drawn from 15 sources, including government agencies, industry panels and academic institutions and Material Safety Data Sheets required by federal regulations. The tables in the Appendix provide the unique Chemical Abstracts Service Registry number for each chemical, which can be used to look up the safety data sheet. California’s fracking disclosure law is the most comprehensive in the nation. The data in the reports submitted to the state’s oil and gas regulatory agency provide the most detailed accounting available of the chemical makeup of fracking fluids, at least for one state.

racking fluid is a mix of water, chemicals and sand that is pumped into underground shale rock formations under great pressure to free up trapped oil and gas. After a well is “treated” in this way, some of the fluid flows back to the surface, usually picking up additional chemicals that occur naturally in the shale. In California, most of the wastewater is disposed of in underground injection wells or in unlined pits, some of them dangerously close to potential sources of drinking or agricultural water. An earlier EWG analysis found that fracking wastewater contains numerous hazardous substances, some at levels much higher than state drinking water regulations allow (EWG 2015).