Crown pillar discussed at hearing

By JOHN PEPIN, Journal Munising Bureau

POSTED: May 19, 2008

MARQUETTE — A downstate contested case hearing on the Eagle Project of the Kennecott Eagle Minerals Company was scheduled to enter its fourth week today.

Testimony last Friday from Kennecott included witnesses discussing engineering and the area between the mine roof and the earth’s surface, called the crown pillar. The crown pillar testimony was expected to continue today and into the middle of the week.

The hearing is considering a challenge to a Michigan Department of Environmental Quality decision to grant Kennecott permits for its nickel and copper mine in northern Marquette County.

The National Wildlife Federation, Huron Mountain Club, Yellow Dog Watershed Preserve and Keweenaw Bay Indian Community are challenging the DEQ issuance of those mining and groundwater permits.

The final witness for the plaintiffs testified last Wednesday. Testimony then shifted to witnesses from Kennecott, and will eventually feature DEQ witness testimony.

“Even though Kennecott’s case has begun, it does not change the strong basis we built while outlining the many flaws in the application and the permits,” National Wildlife Federation attorney Michelle Halley said.

On Friday, Kennecott geologist and Eagle manager of exploration Andrew Ware testified on the extensive process Kennecott undertook to gather geologic and geotechnical data relative to the Eagle ore body.

This process obtains information about the size, shape and metallurgy of the ore body — a critical and integral aspect for designing and engineering the mine for environmental protection and safety.

Kennecott witnesses scheduled this week on engineering and crown pillar issues include:

David Stone, president of MineFill Services Inc., who is scheduled to discuss backfilling the underground mine as mining occurs from the bottom of the ore body to the top as it relates to structural integrity.

The mine backfill design ensures the integrity of the mine’s crown pillar in preventing the potential for long-term subsidence.

Kennecott officials said Stone is a mining and geotechnical engineer with more than 30 years experience. His primary expertise is in mining rock mechanics, and he is an internationally recognized expert in mine backfilling, according to Kennecott.

Tracey J. Arlaud, senior mining engineer with McIntosh Engineering, is expected to focus her discussion on engineering and design elements of the Eagle Project, with specific discussion on the stability of the crown pillar of the mine during normal operations.

Kevin Beauchamp, engineer with Golder Associates, is a geotechnical and mining engineering expert who was integrally involved in the crown pillar design and modeling for the mine. He is expected to review the geotechnical assessments and reports provided to regulators as part of the permit process.

Beauchamp has  experience in crown pillar design for underground mines, with much of that experience with mines in the Great Lakes region.

Trevor Carter, a principal with Golder Associates, is a geological engineer expected to testify that the design put forward by Kennecott for Eagle is safe and stable for workers underground.

Carter is an expert on the stability of various rocks and geology.

Once these witnesses have finished testifying, witness testimony will turn to other issues related to the permits issued to Kennecott, followed by the calling of witnesses by the DEQ.

The contested case hearing is expected to take  another few of weeks to complete. Administrative Law Judge Richard A. Patterson is presiding.

Kennecott cannot begin work on the Eagle Project until the contested case is settled.

Patterson will make a recommendation to DEQ Director Steve Chester, who is the final decision maker. Chester can affirm the permits, change the permits or deny them.

State law requires a decision by the end of June. Afterward, the case could be appealed by either side.