Fracking or hydraulic fracturing as it is more properly known is the pressurized injection of water with chemical additives into a geologic formation. The pressure used exceeds the rock strength and the fluid cracks open or enlarges fractures in the rocks and shale. As the formation is fractured, a “propping agent,” such as sand or ceramic beads, is pumped into the fractures to keep them from closing when the pumping stops and the pressure is released. Natural gas will flow from the fractures in the rock and shale into the wells increasing the recovery of the methane.
Historically, shale wells had been drilled vertically and then hydraulically fractured with 80,000 gallons or less of water and sometimes water and diesel. Diesel use is no longer allowed. However, today the most efficient method for developing the vast low-permeability Marcellus shale reservoirs is high-volume hydraulic fracturing. Wells used for hydraulic fracturing are drilled vertically, vertically and horizontally, or directionally and may extend more than 8,000 feet below ground surface or less than 1,000 feet. The wells can extend several thousand feet horizontally, potentially allowing impact to properties and water supplies far away from the well heads. Fifty thousand to 350,000 gallons of water may be required to fracture one well in a coalbed formation while two to five million gallons of water may be necessary to fracture one horizontal well in a shale formation. Water used for fracturing fluids is acquired from surface water or groundwater in the local area.
No one has ever looked at what the long term implications are for the hydraulic balance and groundwater supply when fracking occurs. The removal of millions of gallons of water, the fracturing of the geological formations, and the high pressure injection of contaminants even at low concentrations into the subsurface could cause significant changes in groundwater flow and quality. Now, the often repeated statement by oil industry executives and the current EPA administration that no documented case of drinking water aquifer being contaminated with fracking fluid has been proven false.
In last Thursday’s New York Times was an article by Ian Urbana outlining information that was part of a 1987 E.P.A. report to congress titled “Management of Wastes from the Exploration, Development and Production of Crude Oil, Natural Gas and Geothermal Energy.” This three volume report was brought to the attention of the New York Times by Carla Greathouse, the study’s lead author. Corroborating documentation was obtained from state archives or from the agency’s library by the New York Times. It appears despite claims to the contrary, EPA has been aware of at least one well documented case of drinking water well contamination from fracking for 25 years. In addition, there are reports from several states noting contamination of drinking water wells in association with fracking. One New York state report reads: “Because of possible underreporting by individuals whose drinking water was contaminated and difficulties in detection, the full extent to which injected brines have contaminated underground sources of drinking water is unknown. However, 23 cases of contamination have been confirmed and 4 are suspected.” http://s3.documentcloud.org/documents/216377/doc-reader-with-epa-report.pdf
http://www.nytimes.com/interactive/us/drilling-down-documents-7.html#document/p1/a27935
In some parts of the country, groundwater is the primary source of drinking water. Residents of 34 of the 100 largest cities in the United States rely on groundwater, as do about 95% of rural households. My own home in the rural crescent would be worthless without my well. Groundwater needs to be protected from anything that can contaminate, damage the water table or impair well production potential. Groundwater hydrology is not fully understood and impairment is not easily seen, only slowly experienced. Groundwater contamination is a particular concern to many of the most vocal opponents of fracking, and although earth’s cleansing capacity is limited, impairment to groundwater storage, flow and well productive capacity should be of equal or greater concern. .
About half the population of the United States depends on groundwater for a significant portion of its drinking water. To help protect these supplies from contamination, the Congress passed Part C of the Safe Drinking Water Act in 1974. This law requires the Environmental Protection Agency (EPA) to establish an underground injection control (LJIC) program. Through this program, EPA, directly or through delegation to states, regulates the design, construction, and operation of underground injection wells, which inject wastes and other fluids below underground drinking water sources. It is time that EPA make their first priority the protection of groundwater.
Historically, shale wells had been drilled vertically and then hydraulically fractured with 80,000 gallons or less of water and sometimes water and diesel. Diesel use is no longer allowed. However, today the most efficient method for developing the vast low-permeability Marcellus shale reservoirs is high-volume hydraulic fracturing. Wells used for hydraulic fracturing are drilled vertically, vertically and horizontally, or directionally and may extend more than 8,000 feet below ground surface or less than 1,000 feet. The wells can extend several thousand feet horizontally, potentially allowing impact to properties and water supplies far away from the well heads. Fifty thousand to 350,000 gallons of water may be required to fracture one well in a coalbed formation while two to five million gallons of water may be necessary to fracture one horizontal well in a shale formation. Water used for fracturing fluids is acquired from surface water or groundwater in the local area.
No one has ever looked at what the long term implications are for the hydraulic balance and groundwater supply when fracking occurs. The removal of millions of gallons of water, the fracturing of the geological formations, and the high pressure injection of contaminants even at low concentrations into the subsurface could cause significant changes in groundwater flow and quality. Now, the often repeated statement by oil industry executives and the current EPA administration that no documented case of drinking water aquifer being contaminated with fracking fluid has been proven false.
In last Thursday’s New York Times was an article by Ian Urbana outlining information that was part of a 1987 E.P.A. report to congress titled “Management of Wastes from the Exploration, Development and Production of Crude Oil, Natural Gas and Geothermal Energy.” This three volume report was brought to the attention of the New York Times by Carla Greathouse, the study’s lead author. Corroborating documentation was obtained from state archives or from the agency’s library by the New York Times. It appears despite claims to the contrary, EPA has been aware of at least one well documented case of drinking water well contamination from fracking for 25 years. In addition, there are reports from several states noting contamination of drinking water wells in association with fracking. One New York state report reads: “Because of possible underreporting by individuals whose drinking water was contaminated and difficulties in detection, the full extent to which injected brines have contaminated underground sources of drinking water is unknown. However, 23 cases of contamination have been confirmed and 4 are suspected.” http://s3.documentcloud.org/documents/216377/doc-reader-with-epa-report.pdf
http://www.nytimes.com/interactive/us/drilling-down-documents-7.html#document/p1/a27935
In some parts of the country, groundwater is the primary source of drinking water. Residents of 34 of the 100 largest cities in the United States rely on groundwater, as do about 95% of rural households. My own home in the rural crescent would be worthless without my well. Groundwater needs to be protected from anything that can contaminate, damage the water table or impair well production potential. Groundwater hydrology is not fully understood and impairment is not easily seen, only slowly experienced. Groundwater contamination is a particular concern to many of the most vocal opponents of fracking, and although earth’s cleansing capacity is limited, impairment to groundwater storage, flow and well productive capacity should be of equal or greater concern. .
About half the population of the United States depends on groundwater for a significant portion of its drinking water. To help protect these supplies from contamination, the Congress passed Part C of the Safe Drinking Water Act in 1974. This law requires the Environmental Protection Agency (EPA) to establish an underground injection control (LJIC) program. Through this program, EPA, directly or through delegation to states, regulates the design, construction, and operation of underground injection wells, which inject wastes and other fluids below underground drinking water sources. It is time that EPA make their first priority the protection of groundwater.
