Toxic Chemicals on Tap: How Natural Gas Drilling Threatens Drinking Water

Released by: Environment America

Executive Summary

    Humans need very few things to survive: air, shelter, food, and water. Fossil fuels (oil, coal and natural gas) pollute the air with smog, soot and global warming pollution, but their effect on water is often overlooked. Natural gas, which the industry touts as the “cleanest of all fossil fuels,” threatens to dirty drinking water with toxic chemicals used in drilling.i  Rivers, lakes and groundwater already face threats from industrial pollution, agricultural runoff, and overdevelopment. Adding an unnecessary threat to one of the most valuable resources is dangerous. The government must act to safeguard drinking water. 

    In light of the increased pressure to drill for more natural gas in states across the country, this report focuses on the dangers to drinking water from gas drilling. In particular, we examined hydraulic fracturing (often called “fracking”), a commonly used process gas companies employ to extract natural gas or oil reserves. Natural gas exists in bubbles underground, much like bubbles in carbonated soda. Getting to these pockets of gas requires injecting millions of gallons of water, sand and chemicals into the ground in order to crack open these bubbles in the rock to allow natural gas to flow to the surface.  

    Because manufacturers are often not required to disclose the make-up of fluids used in fracturing, we cannot present a truly comprehensive portrait of the toxic chemicals used in drilling.  However, the available information from state-required or voluntary disclosures paints a very troubling picture of the toxicity of these chemicals.  We find that many of the chemicals used in fracking pose serious health threats. They harm the nervous system, cause respiratory problems and create reproductive issues. 

    While the chemicals used in drilling near water certainly require monitoring and regulation, drilling also threatens water in other ways. The huge amounts of water required for drilling each site may drain local watersheds. Drilling sites can use up to 7.5 million gallons of water per well.ii  Other problems with the process include inadequate standards for waste disposal, the ability of drilling to force naturally occurring toxics substances as well as the natural gas itself into the groundwater, and a lack of appropriate monitoring of drilling sites. 

    While natural gas may be better in some aspects than its fossil fuel brethren, drilling for natural gas must not put drinking water at risk. In order to assure water safety, we should: 

Avoid Toxic Contamination

  • Replace dangerous chemicals in fracturing fluids with safer alternatives; and
  • Send wastewater to facilities capable of dealing with the issues presented by fracturing fluids.

Plan for Safety

  • Prevent gas drillers from using water for fracturing where it depletes local watersheds; 
  • Drill only in areas safely distant from drinking water; 
  • Require a fee for drilling sufficient to pay for cleanup of abandoned sites and to pay for monitoring, permitting, and enforcement of active sites; and  
  • Create a bonding requirement to make sure that companies have the ability to cover the above costs before drilling begins. 

Hold Drillers Accountable 

  • Make the composition of fracturing fluids public; 
  • Make sure citizens know the quantity and location of fluids injected nearby;
  • Make polluters pay for any contamination they cause; and 
  • Clean up sites when done and replace lost water supplies.

Employ Best Practices

  • Construct drilling sites in a way that prevents the spread of contaminants, such as using steel tanks rather than open pits for wastewater; and
  • Be prepared for problems by using rubber pools to catch spills and frequently monitoring for the possibility of escaped fluids or gases.

i Natural Gas Supply Association, Natural Gas and the Environment, downloaded from, 10 October 2009.  

ii New York Department of Environmental Conservation, Draft Supplemental Generic Environmental Impact Statement on the Oil, Gas and Solution Mining Regulatory Program, September 2009.