What is Hydrofracking?
To recover natural gas deposits in shale formations, including the Marcellus and Utica, the industry uses a process termed high volume hydraulic fracturing, which uses millions of gallons of water, laced with a cocktail of chemicals, to fracture shale and release gas. Read more ...
Inherent Risks of Hydrofracking
Communities from Texas to Pennsylvania have been impacted by industrial fracking operations. Fracking activities operate 24 hours a day, 7 days a week during production. Volumes of toxic, radioactive, and caustic liquid waste by-products pose storage, treatment, and disposal problems. Regular operations, as well as accidents, can adversely impact the environment and public health. Well casings that are intended to prevent methane and toxic liquids from contaminating groundwater are prone to failure. Studies have shown that 6-7% of well casings fail immediately, while 50% fail after 30 years!
Primary concerns include human and environmental exposure to:
- Radioactivity that is a physical characteristic of Marcellus shale.
- The hazardous cocktail of hydrofracking chemicals injected into the ground.
- Air pollution from diesel engines, compressor stations, and flaring.
- Brine that is 5x saltier than seawater that can damage freshwater streams and lakes, as well as corrode infrastructure.
- Hazardous liquid and solid waste that is stored on-site, transported on public roads, and disposed of at municipal landfills or sewage treatment plants.
The Health Impacts of Fracking
While the fracking boom began years ago in other parts of the country, scientific studies on the public health effects of fracking are just now being conducted and reported. Researchers from the Colorado School of Public Health recently determined that air pollution from fracking, which includes known carcinogens, may contribute to acute and chronic health problems for those living near gas drilling sites. Other studies, including the US Environmental Protection Agency study on the impacts of fracking on drinking water, are ongoing.
Hydraulic fracturing is a process of fracturing rock in order to release the natural gas from isolated veins within the shale formation. The fractured rock is kept open using a "proppant" typically composed of sand or other chemicals. High-volume hydraulic fracturing is named because it uses millions of gallons of water per well. In order to capture a commercially viable amount of gas the well is drilled vertically to approximately 500 feet above the formation and then the wellbore is turned horizontal to tap all the tiny pockets and veins of gas in the shale. In Pennsylvania a typical horizontal wellbore is 4,500 feet.
According to the NYS DEC there are four primary differences between horizontal drilling and vertical drilling: 1) larger rigs with longer per well drilling time; 2) a higher likelihood of multi-well pads; 3) Using drilling mud rather than air to cool and power the drill; 4) the volume of rock cuttings associated with high volume hydrofracking.
Multiple wells can be drilled off the well-pad there will be a larger acreage of disturbance during the drilling and during production. During drilling a single well would disturb approximately 3 acres of land and during production where there is partial reclamation there would be 1.5 acres disturbed. For a multi-well pad, 5 acres of land is disturbed, and during production it is 3 acres. Multi-well pads are an attractive solution to minimize land disturbance for natural gas drilling. The drawback is in the concentration of waste generated during the drilling process. Multi-well pads tend to have six wells per pad so the waste generated by a high-volume hydraulic fracturing process is quite substantive.
Drilling mud is used by horizontal, or directional, drilling to cool and power the drill. Drilling mud can be 1) water-based; 2) potassium-chloride/polymer-based with a mineral oil lubricant; or 3) synthetic oil-based. After the drilling occurs the well is fractured. According to the industry it is 98% freshwater, and according to the DEC there are 12 classes of additives proposed to be included: 1) the proppant; 2) acid; 3) breaker; 4) bactericide/biocide; 5) clay stabilizer; 6) corrosion inhibitor; 7) crosslinker; 8) friction reducer; 9) gelling agent; 10) iron control; 11) scale inhibitor; 12) surfactant. These additives are comprised of a variety of chemicals and many of them are toxic. Even though they are only 2% of the solution, the problem is compounded by the fact that this is multiplied by millions of gallons.
Rock cuttings from a vertical well to 7,000 feet would be approximately 125 cubic yards and for horizontal wells drilled to the same depth with a 3,000 foot lateral would be 165 cubic yards.
Read the report, Finger Lakes Region Gas Lease Mapping Report
More information on Marcellus Shale from the NYS DEC
updated by lburch 8/14/14