A Minnesotan’s Guide to the PolyMet Environmental Impact Statement

Laura Gauger

What is all this talk of the PolyMet project?  Chances are you have heard of it and know it’s a copper-nickel mine proposed for northeastern Minnesota in the Superior National Forest. But most Minnesotans do not have a copy of the Environmental Impact Statement (EIS) that outlines the project. And even if they did, the EIS is over 3,500 pages long, filled with technical jargon and difficult to navigate.
Governor Dayton has made it clear he is open to receiving public input on whether or not the State of Minnesota should give PolyMet Mining Corporation (Toronto, Ontario) a permit to build the mine and calls it “the most momentous, difficult and controversial decision” he will make as governor. The Minnesota DNR, too, is seeking public comment.
But the clock is ticking and time is running out. What should we tell them?
The information provided in this report consists of facts pulled directly from the PolyMet EIS and other official documents, allowing you to make up your own mind as to whether or not the mine should get a “Thumbs Up” or a “Thumbs Down.” Footnotes are also included, so you can confirm the information and get more details, if you so wish, by going to the original source.
The PolyMet EIS is available at the second floor desk of the Duluth Public Library. You can also access it on-line by going to the Minnesota DNR website. The on-line version  is “searchable,” so you can find items of interest by typing in key words or phrases.
The first thing you might be wondering is where exactly the PolyMet project site is located. The following map (Figure 4.2.1-1 from the EIS) shows the location relative to towns on the Iron Range, and a second map (Figure 3.2-1 from the EIS) shows an enlarged view of the project site. Both are included here for you to see.

PolyMet’s Plant Site / Tailings Dump.  

I would first like to draw your attention to the “Plant Site” outlined in orange on the map. It’s about 4,500 acres in size and is where the LTV Steel Mining Company piled its tailings for many years (1). The existing LTV tailings dump, which does not have a liner beneath it, covers about 3,000 acres. The average height of the western half is about 200 feet and of the eastern half is about 60 feet (2).
PolyMet proposes to place wet tailings (in slurry form) on top of the eastern half of the original LTV tailings dump and maintain a pond on top of the waste (See Figure 5.2.2-13 from the EIS). The company also plans to stabilize some of the existing perimeter dams and embankments to help prevent collapse (3).
According to PolyMet, the new tailings pile will cover about 1,325 acres (4). To put things into perspective, that’s the size of thirty-three Vikings stadiums. In terms of height, the PolyMet tailings will add about 150-165 feet onto the top of the existing LTV tailings dump, making the combined LTV/PolyMet tailings pile about 225 feet high (the height of a 22-story building) (2, 5).
“Tailings” are the waste products from metal extraction processes like flotation, smelting and hydrometallurgy. According to the EIS, the PolyMet tailings will contain arsenic, aluminum, beryllium, copper, zinc, nickel and sulfate, among other things (6).
PolyMet will be collecting contaminated seepage from the tailings dump and pumping it to an on-site water treatment plant (7). The EIS states that water treatment will be needed “indefinitely … a minimum of 500 years at the Plant Site” (8, 9).
The EIS acknowledges that the Embarrass River would be impacted by PolyMet’s tailings dump, and several different flow paths have been mapped for contaminants making their way from the dump to the river (10).  The company predicts that it will be able to capture and treat about 90% of the groundwater seepage, but the EIS states, “Tailings seepage bypassing the containment system (approximately 20 gallons per minute) would continue to enter the northern, northwestern, and western surficial flowpaths, and migrate slowly toward the Embarrass River” (11).
The Embarrass River drains to the St. Louis River and, ultimately, Lake Superior.

PolyMet’s Mine Site.   

Please take another look at Figure 3.2-1 from the EIS. You will see that, besides the “Plant Site” outlined in orange, there is a “Mine Site” outlined in purple. It’s about 8 miles from the tailings dump, and the two will be connected by road and rail.  There is also a green-and-black checkered line on the map that surrounds 6,650 acres of federal (public) land in the Superior National Forest that PolyMet is trying to secure from Congress.

So what’s that about?

PolyMet’s proposed “Mine Site,” where the company plans to dig three open pits, is located entirely within the Superior National Forest on public land under federal control. Even the ore body itself is on public land, not private. That’s why you may have heard talk of a “land swap.” PolyMet is trying to get control of the property by offering to give the federal government other properties in exchange (12).

The public lands sought by PolyMet can only be transferred to company control if Congress agrees. If the land swap falls through, the project dies.

The proposed “Mine Site” (outlined in purple on the map) covers 3,014 acres (13). The company is seeking to obtain not only this federal land, but a buffer zone around it that would bring the total amount of Superior National Forestland transferred from public to private ownership to 6,650 acres (12).
If PolyMet succeeds in getting this vast tract of water-rich lands, they will proceed to dig three open pits (east, central and west) totaling 530 acres in size. The east pit will be the deepest (maximum depth of about 700 feet) and eventually connect with the central pit (14).  
The company also proposes to store a portion of the waste rock from the mine operation in a permanent stockpile immediately northwest of where the central and west mine pits will be located. The mound will cover 526 acres (about 0.8 square mile) and be about 240 feet high (24 stories) (15).
The crushed sulfide and metal-containing waste rock that is not stored above ground eventually will be backfilled into the combined east/central mine pit where groundwater will saturate the waste. There are plans to add lime to the backfill, if needed, to help control acid mine drainage (16).
The backfilled pits will not be lined, and the 320-acre west pit (630 feet deep) will be allowed to fill with water and become a lake (17).
PolyMet proposes to collect seepage from beneath the waste rock stockpile and pump it to an on-site water treatment plant (15). There are also sketchy provisions in the EIS to pump water from the backfilled east/central pit to the water treatment plant during the reclamation phase (years 21-40), after which the treatment of the water “may continue into closure and long-term maintenance” (18).

The EIS states that water treatment will be needed “indefinitely … a minimum of 200 years at the Mine Site” (8, 9).
It also mentions that the composition of the sulfur and metal-enriched sludge from the water treatment process “would be similar” to the tailings generated by the hydromet plant (where the ore will be processed). Some of the sludge will be “disposed off-site,” but the EIS does not say how many tons or where the dump will be located (19).   

Impacts to Lake Superior and Rainy River Watersheds.   

In terms of river impacts from the PolyMet mine site, modeling shows that contaminated water would move both northward (into the Rainy River/Boundary Waters watershed) and southward (into the St. Louis River/Lake Superior watershed).
The northward flow would be due to a “strong bedrock gradient” toward the existing Peter Mitchell taconite mine pits (Northshore Mine) located about a mile north of the proposed PolyMet mine (20). As stated in the EIS, “Predicted ultimate outflow from the [Peter Mitchell pit] would be from the northeast end of the pit, to the Dunka River in the Rainy River watershed” (21).  The EIS, however, does not include an analysis of any potential impacts from the northward flow of contaminated water into the Boundary Waters watershed.  
Instead, the EIS focuses on the southward flow of contaminated waters to the Partridge River. Modeling shows the mine site “would contribute contaminant loads to the Partridge River from seven groundwater sources” (22, 23), and a map showing those flow paths is included here for you to see (Figure 5.2.2-7 from the EIS).
One of the seven flow paths is from the backfilled east mine pit to the river. The EIS states that, initially, the water in the backfilled pit would have “relatively high solute concentrations” and that, eventually, “the solute concentrations in the pits would stabilize to more or less steady-state values” (24, 25). However, steady-state values do not necessarily mean low levels. In addition, the EIS goes on to state that the timeframe for reaching steady-state “would likely be greater than 200 years as indicated by [modeling] which shows solute concentrations continuing to decrease at year 200, although still above [water quality standards]” (25).
The upshot of all this is that the backfilled PolyMet mine pit will be a “permanent feature that would continue to provide contaminant loading [to the Partridge River] for a minimum of 200 years” (22). The Partridge River, like the Embarrass, drains to the St. Louis River and, ultimately, Lake Superior.


According to the EIS, the PolyMet project will destroy 913 acres of wetlands, most of them rated “high quality.” The destruction would be caused by fill or excavation (26).  
The EIS states that up to an additional 6,500 to 7,700 acres of wetlands located within and around the PolyMet project area either will or could be “indirectly impacted” by the mine  – not permanently lost, but affected by changes in water quality, groundwater drawdown or other factors (27). The EIS does not specify wetland quality ratings (high v. moderate v. low) for any of these “indirectly impacted” wetlands, even though the impacts could be significant.

Groundwater Sacrifice Zone.   

Despite all of the above, PolyMet claims its mine will be in compliance with state law. To the average Minnesotan, that might mean there is nothing to worry about. But please consider the following information from the EIS.
If you look at the map referenced earlier (Figure 3.2-1 from the  EIS), you will notice a yellow line that marks the “PolyMet Owned/Leased Area.”  According to the EIS, this area is roughly 15,000 acres in size (28). When combined with the 6,650 acres of federal lands from the Superior National Forest that PolyMet hopes to secure (the area surrounded by the green-and-black checkered line), the grand total of lands under company control would be roughly 21,650 acres.
This comes into play when trying to figure out exactly where the Minnesota Pollution Control Agency will be enforcing groundwater quality standards at the PolyMet project site.

Here is what the EIS says:

• “Groundwater [quality standards] apply to groundwater at the project property boundary” (29).  

• “The groundwater quality [standards] used in the Final EIS are intended to be used to assess for impacts to groundwater at the Mine Site and Plant Site property boundaries, not within the NorthMet project footprint” (30).   

What those statements suggest to me is that the State of Minnesota will not be enforcing any groundwater quality standards anywhere within the “property boundary” associated with the PolyMet mine – even though, according to the company’s own computer modeling provided by Barr Engineering, the levels of pollutants in the water will be many times higher than standards set to protect people, plants and wildlife (31, 32). And this is no small tract of land. It’s over 21,000 acres of water-rich lands in the Lake Superior watershed.
I found all of this so surprising that I went directly to the Minnesota Pollution Control Agency (MPCA) to ask them about it, and they confirmed that, yes, it’s not until the polluted water crosses the company’s property boundary that groundwater quality standards will be enforced. I was told, “That’s the way the law works.”
Another person who likely could confirm the legal aspects of all this is Brad Moore, PolyMet’s Executive Vice President for Environmental and Governmental Affairs. Mr. Moore used to be the head of MPCA before joining the Barr Engineering/PolyMet team. Surely he is very familiar with the state’s mining regulations.  
I would encourage Minnesotans to ask Mr. Moore about “how the law works.”
The EIS states that levels of contaminants such as arsenic, antimony, copper and nickel in the groundwater at the PolyMet project site “would be reduced when the peak arrives at the property boundary due to attenuation processes” (33), and if you carefully look at the data tables included in the EIS, you will see that compliance with groundwater standards is predicted to occur at the boundary of the 21,600 acres of company-controlled lands and wetlands, not within (34).
Perhaps that explains why PolyMet seems so confident in telling Minnesotans they will be in compliance with state law.  
It’s not that the water within PolyMet’s property boundary will be clean. It’s that the pollution has been legalized.
So there you have it!  Now it’s time to make your views known to Governor Dayton AND the Minnesota DNR.
The public comment period on the PolyMet EIS closes on December 14, 2015.  

Contacting Minnesota DNR

From the Minnesota DNR website:

The public will be able to submit comments to the DNR on whether the final environmental impact statement is adequate. A 30-day public review period begins Nov. 13 and ends Dec. 14. The DNR will consider all comments received during that period in making its adequacy determination.
Public comments can be submitted electronically at NorthMetFEIS.dnr@state.mn.us or by mail to:
Lisa Fay, EIS project manager
Minnesota DNR Ecological and Water Resources Division
Environmental Review Unit
500 Lafayette Road, Box 25
St. Paul, MN 55155-4025

All written comments become a part of the final EIS record and are public information. Written comments will be accepted until 4:30 p.m. on Dec. 14.

Contacting Governor Dayton

Should the State of Minnesota give PolyMet a permit to build its copper-nickel mine in the Superior National Forest?
Here’s how to contact Governor
Dayton with your opinion:

Governor Mark Dayton
116 Veterans Service Building
20 W 12th Street
St. Paul, MN 55155
Telephone: 651-201-3400
Toll Free: 800-657-3717

Email: http://mn.gov/governor/contact-us/form/

Footnotes:   (1) PolyMet Final Environmental Impact Statement (FEIS), Nov 2015, pp. 4-182 and 4-225;  (2) FEIS, p. 4-108;  (3) FEIS, pp. 3-4 and 3-104 to 3-107;  (4) Waste Characterization Data Package, Version 10, PolyMet, March 2013, p. 39;  (5) Geotechnical Data Package, Volume 1, Flotation Tailings Basin, Version 4, April 2013,  p. 68 and Large Figures 10, 11, 13, 14, 15 and 17; (6) Waste Characterization Data Package, Version 10, PolyMet, March 2013, pp. 30-42;  (7) FEIS, pp. 3-119 to 3-123 and 5-7 to 5-8;  (8);  FEIS, pp. 5-8, A-265 to A-267, and A-569;  (9) FEIS, Appendix C, NorthMet Mining Project and Land Exchange PSDEIS (ver. 2) – Tribal Comments and Co-Lead Agencies’ Dispositions, 8/19/2013, p. 12; (10) FEIS, Figure 5.2.2-9;  (11) FEIS, pp. 5-7 to 5-8, and 5-109;  (12) FEIS, pp. 1-1 to 1-2, and 3-163 to 3-173;  (13) FEIS, pp. 3-17 to 3-18; (14) FEIS, Table 3.2-4;  (15) FEIS, Table 3.2-7 and pp. 3-47 to 3-49;  (16) FEIS, pp. 3-64 to 3-65, and A-564; (17) FEIS, pp. 3-64 to 3-65; (18) FEIS, pp. A-658 and A-662 to A-663; (19) FEIS, pp. 3-53, 3-117, A-640, and Figure 5.2.2-20;  (20) Comments on PolyMet mine site contaminant northward flowpath and groundwater model calibration, GLIFWC, August 11, 2015;  (21) FEIS, p. 6-16;  (22) FEIS, p. 5-173;  (23) FEIS, Figure 5.2.2-7;  (24) FEIS, pp. 5-121 to 5-122;  (25) FEIS, p. 5-174;  (26) FEIS, pp. 5-255, 5-265 to 5-269, 5-321 to 5-322 and 5-346 to 5-347;   (27) FEIS, pp. 5-257 and 5-347 to 5-348;  (28) FEIS, p. 4-225;  (29) FEIS, p. A-110;  (30) FEIS, p. A-591;  (31) Water Modeling Data Package, Volume 1 – Mine Site, Version 14, PolyMet, Feb 2015, Large Table 18;  (32) Water Modeling Data Package, Volume 2 – Plant Site, Version 11, PolyMet, Mar 2015, Large Tables 1, 2 and 10-14;  (33) FEIS, pp. A-585 to A-586 and Chapter 5, page 65; (34) FEIS, Tables 5.2.2-23, 5.2.2-38 and 5.2.2-39.