In June, 2015 the US Environmental Protection Agency (EPA) released its five-year study, which found that “hydraulic fracturing activities have not led to widespread, systematic impacts to drinking water resources. The EPA said in its press release that this “is the most complete compilation of scientific data to date, including over 950 sources of information, published papers, numerous technical reports, information from stakeholders and peer-reviewed EPA scientific reports.”

Further, the University of New Brunswick examined the groundwater and water wells near the McCully field in New Brunswick. The study was released by the Geologic Survey of Canada in 2013 and concluded: “there is no indication that development and production at the McCully field has affected the water wells.” A presentation featuring highlights of this study can be found on the website of the New Brunswick Energy Institute (NBEI).

The crucial point to note is that hydraulic fracturing fluids have never migrated upwards from the fractured formation to contaminate groundwater.

According to a recent report by researchers at Cape Breton University in Nova Scotia, “due to the distance between the targeted formation and the aquifer, it is anticipated that fractures would not extend from the shale to the aquifer, and thus direct contamination from hydraulic fracturing fluids would appear unlikely.”

Groundwater

In the United States, state regulators from Alabama to Alaska have also said that hydraulic fracturing does not pose a credible threat to groundwater. Reports by the U.S. Geological Survey, the U.S. Government Accountability Office, the Ground Water Protection Council, and the Massachusetts Institute of Technology have all shown no significant risk.

well casting
Source: Energy in Depth

A typical well consists of more than two layers of thick steel and cement, which are designed to protect groundwater. In a small number of instances, a well may experience a buildup of pressure, which can – in extremely rare cases – lead to leakage between one of these barriers inside the well. But in order for the well actually to leak, every one of those barriers would have to crack and fail. Such instances are extremely rare.

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For example, in British Columbia the Oil and Gas Commission has acknowledged that 10 per cent of the Province’s wells may have experienced such pressure, but that the “gas does not migrate to soil or water — it is trapped within the surface casing protection layer. From there it has to be vented to ensure it is safely disposed.”

Wells in New Brunswick are tested after being cemented in to ensure the cement job was completed properly and effectively. If the well fails these tests, generally referred to as bond log tests and leak tests, then the well must be fixed immediately. Production and hydraulic fracturing can only occur after the well successful passes these tests.