Sign In | Create an Account | Welcome, . My Account | Logout | Subscribe | Submit News | Affiliated Sites | Home RSS

Clearing the air: Mine pro details Rio Tinto work

Guest op-ed

May 6, 2012
Kristen Mariuzza - Environmental Engineer and Permitting Manager, Rio Tinto Eagle Mine , The Mining Journal

The Mining Journal recently reported on Rio Tinto's application to obtain a new air permit for the Eagle Mine. Although we are required to have this permit to operate, we do understand that it is not necessarily the permit that is important to you. It is the assurance that you, your family, our employees and the surrounding environment is not affected by our emissions.

Not only am I part of the Rio Tinto team responsible for environmental performance at Eagle, I was also born and raised here in the Upper Peninsula along with many of you. I want to ensure that we, along with our children and future generations, can enjoy what the U.P. has to offer just as we always have. My responsibility is to ensure Rio Tinto constructs and operates in a world class environmentally protective manner. It is a commitment that we all stand behind.

In 2007, the Michigan Department of Environmental Quality issued all permits required to build and operate the Eagle Mine. We are dedicated to complying with our permits and all other environmental regulations that affect our operation.

Nearly five years have passed since permits were originally issued. Since then, we have refined the design of the mine, and have identified measures that will reduce overall emissions from our operations.

Anytime there is a change in the quality, nature or quantity of air emissions, The MDEQ requires a new permit to be issued. This will consolidate all required air quality standards into a comprehensive document, reducing the potential for noncompliance and improving the ability of regulators to enforce them.

Following are the key modifications realized to further reduce our emissions, resulting in the requirement for a new air permit application.

Eagle was originally designed with three diesel-fuelled generators to provide on-site power for all operations. We have since provided electrical service from Alger Delta and have removed these generators from the design with only a single stand by generator remaining.

Converting to grid electricity will virtually eliminate generator use and the corresponding emissions from both the generators and the fuel trucks traveling to the property. In addition, a portion of the electricity will come from renewable sources, a practice that is fully supported and important to us.

Additional refinements to the site resulted in a reduction to the already low dust emissions expected. Ore handling on the surface will occur in an enclosed building rather than a three-sided structure. Dust inside the mine has been reduced through the improved, eliminated or relocated material handling operations. Rock storage piles and transfers at our backfill plant will now occur indoors. And finally, we moved the crushing activities originally planned for the mine to the Humboldt Mill.

For perspective, the particulate emissions, primarily dust, from Eagle that is listed in our permit application, amount to less than one half of a percent of Marquette County's total industry emissions. In addition, emissions from our mine ventilation system will be equivalent to about 15 home wood burners.

Along with these design changes, the watering program we instituted on Marquette County Road 510/Triple A will reduce vehicle dust by approximately 90 percent compared to before operations. We encourage the use of carpools and provide a bus service to the mine for our employees and contractors.

As part of our commitment to environmental performance, we continually work to ensure compliance with regulatory standards, improve overall air emissions performance, be an industry best practice leader and remain engaged on air quality issues. We constantly review our emissions, look for ways to improve our performance and apply controls to minimize potential impacts from our operations.

We are confident that we can build, operate, and close Eagle responsibly with respect to both the environment and surrounding community. To supplement efforts required by regulators, Eagle will establish independent community monitoring of environmental performance at the Eagle Mine and Humboldt Mill.

This will be a partnership of local universities, the community, local Native American communities and Eagle working together. The purpose of the community-monitoring program is to enable unfiltered information about our performance. We also expect it will identify ways we can improve how we protect the environment.

On this topic and other matters we encourage you to go to our website at, visit our Information Center in downtown Marquette or call us at 486-6970.

Editor's note: Kristen Mariuzza, is environmental engineer and permitting manager for the Eagle Mine project.

Rio Tinto Eagle Mine

504 Spruce Street

Ishpeming, MI 49849

T 906-486-1257

F 906-486-1053



I am looking for:
News, Blogs & Events Web