The Dewey-Burdock site at the headwaters of the Cheyenne River 50 miles from the Pine Ridge Reservation is proposed as the first site for mining uranium in South Dakota’s underground water table. Photo courtesy Azarga Uranium Corp

Environment | Opinion

David Ganje: More study needed on water permit at uranium mine in Black Hills

Thursday, November 2, 2017

Some thoughts on the Dewey Burdock uranium project

By David Ganje
Native Sun News Columnist
nativesunnews.today

Powertech (USA), Inc., a wholly owned subsidiary of Azarga Uranium Corp., is a uranium company with pending applications to South Dakota, the Environmental Protection Agency and the National Regulatory Commission for the development of an in situ uranium mine operation in Custer and Fall River Counties.

This project, known commonly as the Dewey Burdock project, would be the most significant mining operation in the state in the last twenty years. The project is an in situ mining operation which would use two different groundwater aquifers in the course of uranium extraction and in the subsequent disposal of process related liquid waste. I will refer to the company as the developer. I do not represent any of the parties in the matter.

South Dakota contains several distinguishable aquifers. These aquifers are usually horizontal in nature. Aquifers are separated by confinement zones of rock which prevent an aquifer’s waters from flowing to the one above it or to the aquifer below it. The developer’s project involves a number of pending permit and licensing requirements.

In this opinion piece I discuss one aspect of the project: the waste water injection permit which would grant the right to construct and operate injection wells for the disposal of treated waste water into the Minnelusa aquifer. This permit application is under consideration by the EPA. The EPA has not approved or rejected the application.

The Minnelusa is a major aquifer that encircles the Black Hills and spreads out in all directions radially for some goodly distance. The aquifer also runs eastward under all of western South Dakota. Minnelusa groundwater near the project area is hard. It is not used for domestic, municipal or irrigation purposes near the project area. Nevertheless in other areas numerous parties including the city of Rapid City draw upon the Minnelusa aquifer for domestic, municipal, industrial or irrigation use.

The Madison aquifer lies beneath the Minnelusa. Aquifers are separated by confining zones. The Madison is used for drinking water and other similar uses more often than the Minnelusa because its water qualities are better. One issue concerning the use of the Minnelusa as an injection zone for waste water is the question of leakage between aquifers. This is also called hydraulic connection.

If a confinement zone is substantial, leaking is less possible. If a confinement zone, or its surrounding geological features such as faults, is less substantial, leaking between aquifers is possible. The developer in its water rights application stated, based analysis of groundwater from wells and springs in the general region, that some areas’ geologic features may mean water movement between the Madison and Minnelusa aquifers.

The permit application did not provide the developer’s own studies or any hired tests for the immediate project site that address the issue of possible leakage. Unrelated government studies have been done of other geographic areas of the Minnelusa, for example in 2002 and 1985.