By Michele Bourdieu
Kristen Mariuzza, right, Rio Tinto Eagle Project environmental and permitting manager for technology and innovation, and Dan Blondeau, center, Rio Tinto advisor in communications and media relations, field questions from Steve Garske of Marenisco, Mich., as they explain steps in the water treatment system of the Eagle Mine. In the background is the Degassifier, used to remove carbon dioxide from the water being treated. (Photos by Keweenaw Now unless otherwise indicated.)
Thus, when Dan Blondeau, advisor in communications and media relations for Rio Tinto, recently invited Keweenaw Now to take a tour of the Eagle Mine, now that the water treatment facility is in operation as the mine tunnel is being constructed, I decided this would be a good opportunity to learn how it works and to what extent it protects the water. Botanist Steve Garske of Marenisco, Mich., accompanied me on this private tour on July 16, 2012. We both asked questions of Blondeau and Kristen Mariuzza, Eagle Project environmental and permitting manager for technology and innovation, who is also a Michigan Tech University graduate in environmental engineering.
The tour began outside the plant within view of the two large contact basins, together holding 11.5 million gallons of water.
This photo shows parts of the two contact basins and the paved contact area from which they collect water to be treated in the plant. In the background is the portal to the mine, through a decline tunnel being drilled under Eagle Rock, the tree-covered outcrop at the left.
"All of the water from the contact area will flow into these basins, and then all that water is treated through our water treatment plant," Mariuzza said. "Anything that leaves the contact area has to get washed before it leaves. So equipment that operates underground can drive on the contact area, but before it leaves the paved contact area it has to be washed through our truck wash. Water from the truck wash goes into the contact basins."
Mariuzza said the majority of the water they treat is storm water. The basins collect snow melt, any rain that falls on the site, water from the underground and water from the rock storage pad. Effluent from the water treatment plant is sampled monthly, she explained. This depends on how often the company is running the plant.
View of the Salmon Trout River. Rio Tinto-Kennecott is drilling toward an ore body of copper and nickel located under this trout stream. (Keweenaw Now file photo)
Mariuzza said there are two separate (unconnected) aquifers with a confining layer in between them.
"Seepage into the mine is not expected to have any effect on the overlying water resources," Mariuzza said. "The bedrock in the area of the underground mine workings has a very low permeability; therefore it is not a direct channel to the overlying aquifers and wetlands."
Blondeau noted the contact area at the mine site is sloped so that all water in the contact area flows to the contact basins.
"The 'non-contact' water basins are located outside of the contact area," he added. "Therefore, they do not come into contact with mining related activities. They collect storm water (rain and snow) at three locations within the mine site."
Water will flow to these non-contact basins and be naturally reabsorbed into the ground.**
To a question on the test wells, Mariuzza replied they are all permit required wells. The groundwater wells are sampled quarterly.
"We even have wells off-site that we sample," Mariuzza added.
Blondeau described the water treatment plant as "the heart of the site."
"The whole site is designed to treat water," he said.
Inside the plant, Blondeau and Mariuzza showed us each step in the water treatment process.
First, when the mine wastewater comes into the plant to be treated, if petroleum has been detected in the water before it reaches the water treatment plant, it goes through a Nutshell Filter, which is actually made of crushed nut shells. This removes oil from the wastewater.
Next is the Degassifier, which is used to remove carbon dioxide from the water being treated (photo above). The process is similar to the way carbon dioxide escapes from a bottle of soda when you open it.
A breakpoint chlorinator removes ammonia from the water only when the ammonia is high.
The Multiflo Clarifier removes scale-forming constituents such as calcium and magnesium from the water.
The Multiflo Clarifier removes such constituents as calcium and magnesium from the mine water.
"Basically it slows down the water flowing through the plant," Blondeau explained.
He said a coagulant creates bigger chunks so it settles solid metals.
The clean water, from the tank pictured here in the background, goes to the Multi Media Filters, and the waste stream (in the tank in the foreground), goes to the Filter Press.
Next, the solids filtered out of the water are tested and the results are sent to a landfill.
This area is referred to as the 'Filter Cake Disposal' bin. The material is tested, results are given to the Marquette County Landfill (MCLF), and the MCLF determines if the contents can be placed in the landfill. If the contents do not meet the requirements of the MCLF the contents are sent to a facility that accepts the material.
"The MCLF (Marquette County Landfill) has already accepted material from our operations," Blondeau said. "If they decide not to accept them, the test results are sent to a facility that will accept the material. Should they be considered hazardous waste, they would have to be sent farther away (possibly to Detroit or Wisconsin) to a hazardous waste facility."
Mariuzza added, "We don't expect that this will ever come up as a hazardous waste product."
Once the larger solids are removed, multimedia filters (made of different materials) help remove any suspended solids that haven't settled yet, Blondeau explained.
The next step is the Sodium Zeolite Ion Exchange, which removes hardness from the mine water.
This photo shows the Sodium Zeolite Ion Exchange filters. Only two are ever operating at one time. The third unit is on standby; for example, in the event of maintenance the system continues to operate. (Photo © and courtesy Rio Tinto)
In his right hand, Blondeau is holding the contents of a Multi Media Filter and in his left he is holding the contents of the Sodium Zeolite Ion Exchange filter. These contents are placed in the clear containers so that people can see what is inside each filter. The Multimedia filters help remove suspended solids from the water similar to the way a coffee filter removes coffee grounds. The Sodium Zeolite filters remove hardness from the water similar to household water softeners.
Finally, the Reverse Osmosis process (RO) helps purify and treat the water so that it can be reused and recycled. It is similar to the technology used in bottled water.
"We go through the reverse osmosis process two times," Mariuzza said.
This Reverse Osmosis system removes ions from water that has already gone through the previous steps. (Photo © and courtesy Rio Tinto)
"The less you have to pull through these filters the better," she noted. "It's like a screen, but the mesh is so small it removes ions. You can't even see the holes in the filter."
A pump pushes water through the small holes creating pressure -- 500 pounds per square inch (psi) on the first pass and 200 psi on the second, Mariuzza explained.
"Our product water is what gets discharged," she said.
Reverse osmosis also removes mercury present in rainwater in order to meet standards. The pH of the product water is close to neutral. If for any reason it is above or below the standard, the water is taken through the whole process again, Mariuzza added.
Because of a recent spill of hydrochloric acid at the plant, we asked what it was used for.
"One of the things we use hydrochloric acid for is to adjust the pH," Mariuzza said.
Both Blondeau and Mariuzza confirmed the acid spill was in a contained area and under control.
The Yellowdog Watershed Preserve (YDWP), on their Web site, expressed concern about the spill even though the company said they were not overly concerned about potential environmental damage.
"While the mining company considered this a 'relatively small' spill, hydrochloric acid is a strong, highly corrosive acid which can be very harmful to human tissue," the YDWP article stated. "YDWP will continue to keep an eye on the situation and be a leading force in monitoring our local resources to ensure our community is protected."
Following the Reverse Osmosis, an evaporator is used to remove the liquid fraction from the liquid waste, and the water vapor is condensed and mixed back into the treated reverse osmosis water. The Crystallizer removes salts that are tested and sent to a landfill that accepts waste.
In this photo the Evaporator is on the right and the Crystallizer is center/left of the two white pipes.
Mariuzza said the product water is sampled before it goes to the discharge -- a Treated Water Infiltration System (TWIS). The process is similar to a drainfield. It goes through perforated pipes into the groundwater, and test wells sample it.
Next we rode in the Rio Tinto vehicle to see the Temporary Development Rock Storage Area. Development rock is waste rock from the decline tunnel and does not contain nickel and copper ore.
This storage facility is for development rock, which is all rock removed from the underground that is not considered ore. The facility features a multi-layered liner, leak detection system and sump pump to collect water which will be treated by the water treatment plant. It is considered environmentally secure. All development rock will be returned underground as fill.
We asked if we could ride closer to the portal for a photo of the decline tunnel now being drilled under the outcrop known as Eagle Rock in order to access the ore body.
The decline tunnel is 18 feet in diameter and descends under Eagle Rock at a 13 percent grade (Every 100 feet it drops 13 feet).
This closer view of the decline tunnel shows the orange part of a pipe going underground and pulling clean air into the tunnel. (Photo © and courtesy Steve Garske)
According to a recent L'Anse Sentinel article about a July 25, 2012, Rio Tinto community forum in L'Anse, the company said the tunnel is to be a mile long and is now 70 per cent complete.
Local residents seek air quality monitoring
Big Bay residents recently complained about diesel fumes and a filter being removed from the exhaust of the tunnel. They are seeking an independent air monitoring program for the region. Carla Champagne of Concerned Citizens of Big Bay expressed these concerns at Rio Tinto's Annual General Meeting (AGM) in London, England, last April. In May, Powell Township passed a resolution stating, "in response to Citizen’s concerns, we the Powell Township Board do ask that the Environmental Protection Agency and or the Michigan Department of Environmental Quality develop an Air Quality Monitoring program in our region, with monitors installed at present and future mine sites, within the community of Big Bay, and at any other sites in Powell Township that these agencies deem appropriate."***
Both Mariuzza and Blondeau said they have never smelled diesel in the tunnel.
"We have refined the design of the mine, and we have identified measures and systems that can reduce overall air emission impacts from the site," Blondeau said. "MDEQ
(Michigan Department of Environmental Quality) requires a new permit application to be filed if there is a change in quality, nature or quantity impact of emissions. In accordance, we filed the new air permit in March of this year. The revised permit does not include a baghouse filtering system. A baghouse would not work properly because expected emissions will be so low that the filter would not work properly. Baghouse filter manufacturers have advised us that their products are not designed for emissions as low as ours. We are working with Superior Watershed Partnership on a community monitoring program. A portion of the monitoring will directly address air."
Blondeau also commented on the fence around Eagle Rock, which the Anishinaabe (Ojibwa) people consider a sacred site.
This photo shows the outcrop, Eagle Rock, which is surrounded by a fence. The decline tunnel being blasted to access the ore body is at right. (Photo © and courtesy Steve Garske)
"Activities prohibited in our lease include, 'Clearing of, or mining operation activities on the rock outcrop,'" Blondeau noted. "We are not allowed to remove any trees or vegetation from the area inside the fence."
He said the fence is several meters out from what is defined as the rock outcrop.
"When members of the Keweenaw Bay Indian Community (KBIC) visit the rock we do not go up on the rock with them unless they invite us up," he added.
Native Americans visit Eagle Rock
Although two Native Americans were arrested when the fence went up in 2010, Native people are allowed to visit Eagle Rock for spiritual ceremonies.
Two Keweenaw Bay Indian Community (KBIC) members who visited Eagle Rock recently -- Charlotte Loonsfoot and Jessica Koski -- shared their impressions with Keweenaw Now.
"Native People are not allowed to hold our ceremonies as we desire to at Eagle Rock," Loonsfoot said. "If we were able to stay about four nights and four days, then we would be able to do our Ceremonies, but they tell us we have to leave every night which is not allowed in our way. I hope someday this may change as we really need to help our spirits heal from all the pain and turmoil Kennecott/Rio Tinto has imposed on us."
Koski said she has visited Eagle Rock twice since the fence was put up around it in 2010 -- once shortly after "the arrest of two fellow tribal members who were honorably defending our sacred place, lands and waters from the disruptive intrusion of a foreign extractive mining company on our traditional Anishinaabe lands."
Her second visit was on July 20, 2012, when she took a small group of KBIC high school students to the Yellow Dog Plains.
"We gathered lots of wild raspberries and saw traditional trail marker trees of ancestors. We visited and drank from some of the freshwater springs there that help feed the headwaters of the Salmon Trout River. It was the most clean, cool, refreshing water I have ever tasted," Koski said. "Unfortunately, these springs are hydrologically connected to an aquifer that is to be injected with at least 20,000 gallons per day of partially treated waste water from the Eagle sulfide mining project."
Koski said that for her and the students it was not a mine tour, but a visit to a sacred place.
"Imagine, you are going to Church, but before you go you have to get permission from a company who is doing heavy construction all around and beneath. You are not sure whether it is a completely safe place to visit as you can smell chemicals and explosives lingering in the air, but it is your Church where your family has gone for many generations, so you can't just move to a new Church. Then image that you are escorted to a guard office, read liability legal language, and asked to put on a corporate hard hat, safety goggles and florescent vest. Then, you are not free to proceed on your own to your Church. A company official, or two, have to walk you to your Church. Then, as you finally reach the Church, the company official 'allows' you to go in, but stands and observes nearby. Just as you are about to proceed, you hear and feel blasting and rumbles beneath your feet." ****
Mine tour impresses; concerns about water remain
Garske said he found our tour interesting and the guides effective in doing their job.
"My overall impression of the tour was that our guides were intent on convincing us that everything was going well and according to plan, that the company was doing everything they can to see that the water would not be contaminated, that the rock would be protected, and that everything would be just fine," Garske said. "That's their job and they were working fairly hard at it."
However, he added he still has some concerns about the water and the Salmon Trout River.
"From what I've seen and heard, the hydrology of this whole area is extremely complex," Garske said.
He said he was also wondering how the company could keep water from the river from percolating (or gushing, if the mine collapses) into the mine, thus lowering the water table and the river.
"I am also concerned (as many others have been from day one) about potential leaching of acid and metals from the mine," Garske added. "Can this leachate be prevented from entering the groundwater and eventually making its way underground, north to the springs and streams that flow into Lake Superior?"
Mining expert Jack Parker, who has expressed concern about a possible collapse of the mine based on the plans in Kennecott's mining permit application, toured the mine in October 2011 with Michigan Tech professor Stanley Vitton, shortly after the blasting in the portal began. While Parker did not tour the water treatment plant, his overall impression was that Rio Tinto-Kennecott was trying to do everything right.
"My unanswered questions are related more to the application -- are the data in the mine design and planning the only departures from reality?" Parker writes. "So in Water Treatment I truly question the projected water quantities and chemistry. RT (Rio Tinto) is relying on figures in the application. Nobody here on Earth can vouch for future climate. I wonder how often we will experience 100-year floods …"
Parker commented favorably on the mining equipment he saw.
"We saw the mining equipment -- all first-class," Parker notes. "An electric/hydraulic face-drilling jumbo, computer controlled, costs $1,250,000, as did the backup machine. The underground haulage trucks carry 50 tons. Highway trucks will actually carry 50 tons in two 'bins' on two trailers, with one prime mover."
These are the mine haulage vehicles that go underground.
Parker also entered the decline tunnel and was impressed by the safety features and precautions.
After mine closure, Blondeau said, the water treatment plant must remain on the site at least five years as part of the 20-year post-closure monitoring.
"If for some reason we still need it after five years, we would leave it up," he said. "After closure everything has to be taken out (buildings, concrete, etc.)."
The mine will be backfilled as they drill upwards. Primary stopes will be backfilled with cemented rock, and secondary stopes will be backfilled without cement, Blondeau explained.
"It's really a very small, concentrated ore body," Blondeau said.
Although the original application said the ore would be hauled to a railhead near Marquette, it is now to be hauled to a mill at Humboldt.
"The DEQ doesn't have jurisdiction on the route," Blondeau explained. "Our permit doesn't specify the route we have to take." *****
The Eagle Mine project now employs more than 60 percent local employees, Blondeau said. At the time of this tour the total number was 90 employees of whom 61 were local.
"Again, this includes Kristen and me," he added. "I was born and raised here. I have the utmost confidence in our people (RT). ... If I didn't think they were doing everything right I wouldn't work here."
Mariuzza, also a local resident, said she worked for the Michigan DEQ for 10 years, then took three years off to stay home with her young children before accepting the position with Rio Tinto.
"I think we have a great environmental program and monitoring program," she said.
Keweenaw Now asked Blondeau about Rio Tinto's current exploration activities at various sites in the region.
"We continue to explore the central and western UP, but we haven't found any mineralization yet," Blondeau replied.
* See our May 3, 2011, article, "Updated: Residents concerned about water quality question Rio Tinto-Kennecott at community forum."
** See Rio Tinto's Web site for overview photos and a site legend.
*** See our May 23, 2012, article, "Updated: Big Bay residents report on Rio Tinto AGM in London."
**** Jessica Koski recently posted these comments on Facebook. UPDATE: Click here to read Koski's complete article, "Political Ecology in the Upper Peninsula of Michigan: A Sacred Place or Mine Portal?" posted Aug. 8, 2012, on Stand for the Land.
***** Rio Tinto is presently considering the proposed County Road 595 as a haul route to the mill at Humboldt, but federal agencies have concerns about potential environmental impacts if this road is built. The Michigan Department of Environmental Quality is considering issuing a wetlands fill permit to the Marquette County Road Commission under Section 404 of the Clean Water Act and Sections 301 and 303 of the Michigan Natural Resources and Environmental Protection Act for the proposed County Road 595. According to MCRC's permit application, construction would affect 25.81 acres of wetlands and require building 22 stream crossings. The Environmental Protection Agency has raised concerns about the wetland and stream impacts and will hold an informational public meeting at 6 p.m. followed by a formal public hearing at 7 p.m. on Tuesday, Aug. 28, at Northern Michigan University's Don H. Bottum University Center Ontario/Michigan/Huron Rooms, 1401 Presque Isle Ave., Marquette. Click here for details.