Native Sun News: Gold mining still causing problems in Black Hills

The following story was written and reported by Talli Nauman. All content © Native Sun News.

LEAD, SOUTH DAKOTA — A little more than a century after gold discovery sparked the violation of Sioux treaty rights to the Black Hills, the precious metal is still causing violations – now of health and environmental protections.

Runoff pollution from the 260-acre Gilt Edge Mine Site, located five miles southeast of Lead, exceeds water quality standards for temperature, suspended solids, and nitrates, according to a December 2010 update on the EPA’s five-year review of the site.

The runoff flows into Strawberry Creek and Bear Butte Creek, which are part of the lower Belle Fourche watershed, a fish breeding habitat and contributor to domestic drinking supplies.

A decade ago the federal government placed the Gilt Edge Mine on the National Priority List for cleanup of toxic waste, declaring it a Superfund Site. The hazardous heavy metals at the site are the target of the cleanup. They include arsenic, cadmium, copper, lead, selenium, thallium and zinc.

The update notes that regulators are following a recommendation from the 2007 review, which calls for them to “continue monitoring”.

However, they say they cannot follow another recommendation to use a more sensitive detection method for cyanide monitoring because “no analytical technique for site water is available that provides a lower detection limit.”

Cyanide is used for leaching gold from ore. The recommendation for stricter monitoring stems from the fact that the water quality standard for the chemical compound is stricter than the level at which it is being measured. The update does not specify whether the cyanide level is in compliance with the standard.

Through November of 2011, the EPA says it will be overseeing the injection of grout into bedrock fractures at the site, to prevent clean water from becoming contaminated by the chemicals there. The injection process began in 2009.

According to an Enforcement Case Report that the Native Sun News generated with EPA digital tools on Dec. 31, 2010, representatives of the Canadian investors of the Gilt Edge and their U.S. subsidiary Brohm Mining Co. (BMC) have agreed to repay tax-supported cleanup costs in the amount of a total $13.46 million.

The money will go to reimburse emergency response actions taken by the EPA and South Dakota Department of Environment and Natural Resources (DENR) in the late 1990s when Brohm abandoned the mining operation.

The EPA already has spent more than $91 million to prevent hazardous substances from spreading downstream from the Gilt Edge Mine.

The agreement for partial repayment is the result of lawsuits filed against the parties in federal court by the state of South Dakota and the U.S. government.

Small underground mines were precursors to the Gilt Edge open-pit, cyanide heap leach operation on what today is FS Road 170. Metal-laden mill tailings of claims dating back to 1876 had already sullied Strawberry and Bear Butte creeks when BMC obtained a state mining permit in 1988 to develop two open pits, a large cyanide heap leach pad, and a 12-million-cubic-yard valley-fill waste rock dump. During construction and operation, BMC cleaned up a lot of the historical tailings both on and off-site.

But after Brohm had mined out the permitted reserve in 1992, inspectors confirmed acid mine leakage from its waste dump, requiring the company to cover the cleanup costs. Because its Canadian parent company was undergoing reorganization, Brohm then proposed a new Anchor Hill Project to mine adjacent to the Gilt Edge and help defray the costs of the first project with proceeds from the second.

Then the company notified the state it was abandoning the second project in 1998, due to lack of financing to achieve Forest Service permitting for expansion, which was opposed by environmental groups.

The state successfully sued for a temporary restraining order and a preliminary injunction to prevent Brohm from abandoning the site. But its parent company filed bankruptcy in Canada in July 1999, and taxpayers were left holding the environmental bag.

Superfund National Priority Listing was granted for the abandoned site on Dec. 1, 2000.

(Contact Talli Nauman at:

Join the Conversation