PolyMet’s SDEIS: Perpetual water treatment and sulfide mining are synonymous – some are just having difficulty recognizing it

Carla Arneson

Definition of perpetual: “Continuing or lasting for an indefinitely long time.” Like centuries.

Legal Definition of perpetual: “That which is to last without limitation as to time; as, a perpetual statute, which is one without limit as to time, although not expressed to be so.” (Black’s Law Dictionary)

Definition of perpetual existence of a corporation: “having no end date.”

PolyMet, a corporation without an end date is perpetual but its pollution, also without an end date, is not perpetual?

The Supplemental Draft Environmental Impact Statement {SDEIS) description of PolyMet’s NorthMet Project pollution: “Both mechanical and non-mechanical treatment would require periodic maintenance and monitoring activities. Mechanical water treatment is part of the modeled NorthMet Project Proposed Action for the duration of the simulations (200 years at the Mine Site, and 500 years at the Plant Site). The duration of the simulations was determined based on capturing the highest predicted concentrations of the modeled NorthMet Project Proposed Action. It is uncertain how long the NorthMet Project Proposed Action would require water treatment, but it is expected to be long-term; actual treatment requirements would be based on measured, rather than modeled, NorthMet Project water quality performance, as determined through required monitoring.” In other words, wait and see just how bad it will get, then monitor and decide on “actual treatment requirements.”

“Modeled.” “Simulations.” “Highest predicted concentrations.” “Uncertain.” “Long-term.” Tucked among the verbiage evidence that the pollution will be worse than the predicted (minimum) of 200 years at the mine site and 500 years at the plant site. The United States has only been around for 237 years.

“Long-term” water treatment, for more than twice the time our country has existed – with no end in sight – certainly fits the definition of perpetual. And lest we forget, Minnesota saw how well computer modeling worked out with the Pagami Creek fire.

Financial assurance is not the answer Financial assurance is not the answer for one simple reason. If a bonding company does take on the risk of PolyMet or any other sulfide mine, PolyMet’s SDEIS indicates there is high probability that sulfide-mining contamination of surface water, sediments, ground water, and soil cannot be cleaned up in our lake district. Money cannot fix the unfixable. Or replace the irreplaceable.

Reverse osmosis is not the answer
Sulfide mining in water intensive areas has never been done without contaminating surrounding waters. Reverse osmosis is not “new” technology. It has been around for decades. If it could solve water contamination caused by metal mining it would have done so by now. Reverse osmosis cannot even solve water pollution at Minnesota’s taconite mines, which are operating under variances or expired permits. In addition, in Minnesota, mining permits are often written to deliberately leave out or weaken important contaminant parameters.

Promotion of reverse osmosis has been deceptive. The company neglects to point out that reverse osmosis will only treat part of the contamination from PolyMet’s proposed NorthMet Project, only treating discharge water at the end of the 20-year operation; it will not treat water going to the tailings basin for the proposed 20 years of production. As multiple types of waste chemicals concentrate in the basin (alleged in the proposal as closed system) the treatment will become less effective, (e.g. 80% of 1000 ppm leaves 200 ppm, 80% of 2,000 ppm leaves 400 ppm). Keep in mind that many of the stream standards are in the parts per billion level.

A filtration system is only as good as the water you put into it. The proposed closed loop system of
PolyMet is comparable to leaving a gallon of dirty water (total dissolved solids) in the bathtub each time you take a bath. All mining companies say they will have no discharge and will keep recycling. However, it does not work that way. Minntac is a closed system. The only solution to its contaminated wastewater is to contaminate surrounding waters. Reverse osmosis was tested for Mesabi Nugget and it was found to be too costly or it did not work. The company could not meet standards and obtained a variance to violate Minnesota’s water quality standards.

Reverse osmosis for Polymet is not scientifically defensible. No testing has been done that is relevant to the actual mining and treatment situation for this application. No substantive data indicates that reverse osmosis will work to fully meet water quality standards. In PolyMet’s case reverse osmosis was tested, but using what? It is unclear just what was run through the reverse osmosis system. Was wastewater used from its mineral extraction bulk sample testing? Compared to what PolyMet proposes to actually run through a full-scale treatment system, the ‘real’ water will be much worse. Pre-filter plugging and reject water disposal will be major issues. PolyMet underestimates the quality and quantity of input water that will need to be treated.

All filtration systems (Reverse Osmosis & Nano-filtration) require backwashing (backflushing) the pre-filters and the final filter. Since the pre-filter waste is a concentrate of the input wastewater it will likely be aquatically toxic. Depending on the quality of the input water, up to 40% of the input water can be this reject back flush. The proposal is to return reject water to the tailings basin. Sludge may go to a landfill, but is untested and likely to be aquatically toxic. Precipitation (rain, snow) will impact the hydrometallurgical residue facility (solids dump). The solids dump will cause leaching. Since the waste particles will be similar to silt or clay, treatment of the solids to prevent toxic leachate will be difficult if not impossible to treat into perpetuity.

Ignorance is not the answer
PolyMet takes only a small number of samples in their environmental testing processes, which does not represent what will occur in the real world. The heterogeneous mixture of rocks is not consistent and small samples cannot reflect anywhere near actual field conditions. This can be demonstrated with field data from both the Dunka mine and MinnAmax, which has demonstrated that water quality is much worse than the small scale lab testing that has been performed.  This difference is caused by the heterogeneity (disseminated) nature of the entire deposit; one spot will have lots of sulfur, another spot will have little sulfur. They have only taken a very limited number of environmental laboratory samples in this heterogeneous deposit. In comparison, to evaluate the economics of the minerals, they report taking thousands of analyses to define the 1% of the minerals that are of economic interest.   

The Mine pits will eventually fill with water. The north wall of the East pit is Virginia Formation. It is
well documented that this formation contains high sulfates and other heavy metals. This fractured mineralized wall will leach acid and metals. The Mine pits will eventually discharge, carrying contaminated pit water to the wetlands and the Partridge River. “The East Pit, West Pit, and Category 1 Stockpile are permanent features that would continue to provide solute-loading [metals and sulfate] for a minimum of 200 years.” (SDEIS) How the agencies picked a minimum of 200 years is a mystery; nothing is going to stop it. Take a look at the toxic Berkeley Pit if you want a preview.

The current PolyMet mine is designed for the 100-year storm (a 1980s statistical description of a 1% chance of a very high precipitation storm); given climate change, this design is insufficient. Scientific studies suggest the facility must be designed to withstand a 500-year storm, because the 1980’s 500-year storm is now occurring almost as often as the 100-year storm. For Polymet this is critical, it must be able to manage huge volumes of wastewater; if the storage and/or treatment system is
insufficient, untreated wastewater overflows to the nearest stream partially treated or untreated.
Compromise is not the answer
In the news recently the sulfide mining issue has been portrayed as an internal DFL problem; it is far bigger. This is a political issue that has crossed party lines. This is about Minnesota, not about any political party. Minnesotans love their lakes. They care about their children’s health. Republican or Democrat.

Sulfide mining is not an issue solved by “compromise” as some suggest. Compromise what? There is no acceptable trade-off for perpetual water pollution and increased neurological damage to our children, some of it inheritable, for unknown numbers of generations. Compromise how? By selling out our children and our waters? Hardly in the public’s best interest.

Multiple multi-national corporations are waiting for PolyMet to get permitted, to set the standards, while our agencies fail to address the overwhelming cumulative effects of a sulfide-mining district.

In northern Minnesota, with its interconnected wetlands, streams, rivers, and lakes, sulfide mining pollution requires perpetual water treatment, whether the industry and our agencies use the word perpetual or rhetorically camouflage it. Why the subterfuge?

The answer
Minnesota cannot legally permit a mine that requires perpetual water treatment.

In the Preliminary SDEIS, the consulting firm Environmental Resources Management (ERM) – picked by the Minnesota Department of Natural Resources (MDNR) and paid for by PolyMet – succinctly stated, “For purposes of this SDEIS, the WWTF (wastewater treatment facility) is considered a permanent facility and would be discharging treated effluent for perpetuity.” (Duluth News Tribune) Perpetuity is perpetual.

Released to the public on December 6, the final version of PolyMet’s SDEIS is a fabrication, morphing from ERM’s determination of water treatment for “perpetuity” to a watered-down version, “Modeling predicts that treatment activities will be a minimum of 200 years at the Mine Site and a minimum of 500 years at the Plant Site. While long term, the time frames for water treatment are not necessarily perpetual;” then that weaker version morphed too, essentially disappeared. By the time the general public saw PolyMet’s SDEIS there was no mention of perpetual. Vanished. A redacting magic act!  
And by then the public’s right to know had been emasculated even further. “Minimum” had been cut, no longer delineating water treatment of “200 years at the mine site and 500 years at the plant site.” Water treatment “for the very long term” became “long term.” But one telling word survived, it concerned closure, and “transitioning from mechanical to non-mechanical/passive water treatment if or when proven effective.“ (SDEIS 3.1.1) IF. If, or when, proven effective! Sophistry.
 During the April 9, 2013 panel discussion on nonferrous mining at the University of Minnesota-Duluth, MDNR Commissioner Tom Landwehr was asked whether the MDNR could issue a permit if it received a plan that called for long-term treatment. “Landwehr replied that treatment would need to be passive (such as water being filtered through a wetland) or not active at closure.” (Cook County News Herald)

Minnesota Administrative Rules concerning closure and postclosure maintenance (Minnesota Rule 6132.3200) states: “The mining area shall be closed so that it is stable, free of hazards, minimizes hydrologic impacts, minimizes the release of substances that adversely impact other natural resources, and is maintenance free.” Perpetual water treatment is not maintenance free.

The permitting process for sulfide mining needs to stop in Minnesota. It is not only delusional in Minnesota’s water rich environment, by law it is over.