As natural gas production rapidly increases across the U.S., its associated pollution has reached the stage where it is contaminating essential life support systems – water, air, and soil – and causing harm to the health of humans, wildlife, domestic animals, and vegetation. This project was designed to explore the health effects of products and chemicals used in drilling, fracturing (frac’ing, or stimulation), recovery and delivery of natural gas. It provides a glimpse at the pattern(s) of possible health hazards posed by the chemicals being used. There are hundreds of products in current use, the components of which are, in many cases, unavailable for public scrutiny and for which we have information only on a small percentage. We therefore make no claim that our list is complete.
Toxic chemicals are used at every stage of development to reach and release the gas. Drilling muds, a combination of toxic and non-toxic substances, are used to drill the well. To facilitate the release of natural gas after drilling, approximately a million or more gallons of fluids, loaded with toxic chemicals, are injected underground under high pressure. This process, called fracturing (frac’ing or stimulation), uses diesel-powered heavy equipment that runs continuously during the operation. One well can be frac’ed 10 or more times and there can be up to 28 wells on one well pad. An estimated 30% to 70% of the frac’ing fluid will resurface, bringing back with it toxic substances that are naturally present in underground oil and gas deposits, as well as the chemicals used in the frac’ing fluid. Under some circumstances, nothing is recovered.
Drilling or reserve pits are found on most well pads. They hold used drilling muds, frac’ing fluids and the contaminated water (produced water) which surfaces with the gas. Produced water is found in most regions where gas is extracted and continues to surface for the life of the well (20 to 30 years). It is a common practice to haul it in “water trucks” to large, central evaporation pits. Many of the chemicals found in drilling and evaporation pits are considered hazardous wastes by the Superfund Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Upon closure, every pit has the potential to become a superfund site.
Potable and arable water resources in the West are already marginal and especially vulnerable to contamination. Mountain watersheds that provide drinking and irrigation water for vast numbers of people downstream are at risk of contamination as a result of the Bureau of Land Management (BLM) leasing of hundreds of thousands of acres of underground mineral and gas resources to energy developers. Just as there is no accounting for what happens to the millions of gallons of fluids used to drill and fracture each well, there is no accounting for the source of the water being taken to complete these processes, how much of the fluid is water, and where and in what condition it is returned to the watershed.
In addition to the land and water contamination issues, at each stage of production and delivery, tons of toxic volatile compounds, including benzene, toluene, ethylbenzene, xylene, etc., and fugitive natural gas (methane), escape and mix with nitrogen oxides from the exhaust of diesel-driven, mobile and stationary equipment to produce ground-level ozone. Ozone combined with particulate matter less than 2.5 microns produces smog (haze). Gas field produced ozone has created a serious air pollution problem similar to that found in large urban areas, and can spread up to 200 miles beyond the immediate region where gas is being produced. Ozone not only causes irreversible damage to the lungs, it is equally damaging to conifers, aspen, forage, alfalfa, and other crops commonly grown in the West. Adding to this is the dust created by fleets of diesel-driven water trucks working around the clock hauling the constantly accumulating condensate water from well pads to central evaporation pits.
All meaningful environmental oversight and regulation of the natural gas production was removed by the executive branch and Congress in the 2005 Federal Energy Appropriations Bill. Without restraints from the Clean Water Act, Safe Drinking Water Act, Clean Air Act, and CERCLA, the gas industry is steamrolling over vast land segments in the West. Exploitation is so rapid that in less than 6 months in one county, 10 new well pads were built on the banks of the Colorado River, the source of agricultural and drinking water for 25 million people downstream. Spacing has dropped from one well pad per 240 acres to one per 10 acres. From the air it appears as a spreading, cancer-like network of dirt roads over vast acreage, contributing to desertification.
The information here is based on chemicals used in drilling a natural gas well, Crosby 25-3, in Park County, Wyoming. Natural gas, petroleum condensate, and drilling fluids were accidentally released from the ground adjacent to the well due to a breach in the surface casing. This occured over a period of about 58 hours between August 11 and 13th, 2006.
Fracturing, frac’ing, and stimulation are terms used to describe a process commonly used to facilitate the release of natural gas and to improve production. In this process, depending on the geology of the region, as much as one million gallons of fluid or more are injected underground under extremely high pressure to open up fractures in the strata being mined. The fluids used in this process are composed of water and a variety of chemicals.
Several different types of pits are used in natural gas operations. Drilling pits are earthen-bermed reservoirs on the well pad used for storage of discarded fluids from drilling, fracturing or other processes. These might be lined with heavy plastic sheeting, or unlined. Large evaporation pit complexes are used to dispose of water stripped from the natural gas as it surfaces, and the fluids from the drilling pits. These pits can be either commercial, servicing many drilling companies, or private, operated by one company. Natural gas processing plants also use pits to dispose of the water used to “wash” the gas before it leaves the refinery.
In 2007, an industry committee comprised of 19 oil and gas companies operating in New Mexico sponsored a sampling and analysis program (SAP) of pit solids. The SAP was completed by a third party consultant and analytical laboratory. The SAP focused on six drilling reserve pits in the San Juan Basin of northwestern New Mexico and the Permian Basin of southeast New Mexico prior to closure. TEDX’s analysis of the chemicals, their relevance to national toxics lists, and an EXCEL spreadsheet (which can be downloaded, searched and sorted as needed) are provided below.