Hydraulic Fracturing and Drinking Water

I have many serious concerns about high volume horizontal hydrofracturing in tight shale

formations. This paper will focus on the cumulative effects of this process on drinking water and

specifically on the repeated fracturing of each well over its productive life.

Although there has been considerable experience with hydrofracturing in conventional oil and

gas fields for many years, the process currently used in tight shale formations is relatively new

and vastly different. Hydrofracking in conventional fields, if done at all, is typically performed

either at the initial completion of a well or as a means of secondary recovery late in the well’s

life. In tight shale formations the process is typically performed at relatively higher pressures in

dense shale of low porosity. It must be done at the initial completion of the well and then

repeated many times over the life of the well because of the rapid decline rates. Experience with

this type of tight shale hydrofracking on a large scale goes back only about ten years, so only a

few of these wells have been fracked more than once. However, all of these wells will have to be

fracked many more times at shorter and shorter intervals due to the rapid decline rates. At this

time we simply do not know how many times the process will be attempted or what the

cumulative effect of this repeated hydrofracturing will be. (This is one of the gaps in the EPA

study that you asked speakers to identify during the hearings in Binghamton, NY.)

Each successive hydrofracturing of a well will extend the fracture zone further from the

horizontal well bore. In areas like New York and Pensylvania, where there are numerous existing

natural fissures, each successive use of the process incre...

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...proved facilities prior to

commencement of each hydrofracturing procedure.

Require periodic subsidence checks above each well bore and the termination of any further

hydrofracturing if subsidence is detected.

It must be understood that the foregoing is not all-inclusive and that additional precautions

should be considered. However, none of these precautions individually or in combination will

entirely remove the risks associated with this process. Additionally it should be noted that this

paper is limited to the impact of the process on drinking water. A similar assessment needs to be

performed on the cumulative risk of air pollution from the process.

In summary, it is critical for the EPA in its studies to consider that hydrofracking will occur

many times at each well and to assure that the true cumulative risks of this activity are properly

addressed.