Designed to Fail

Back Forty Tailings Facility ‘Not a Pond,’ Aquila Says”?

Response by the Mining Action Group

The Aquila Back Forty’s Mining Permit amendment, under consideration by the Michigan Department of Environmental Quality, features a tailings dam (aka “tailings management facility”, or TMF) to be built using the extremely risky “upstream” method.  Objections to the Back Forty’s TMF design have been raised by numerous environmental groups, including the Mining Action Group of the Upper Peninsula Environmental Coalition, Menominee River Front 40, the Coalition to Save the Menominee River, the Center for Science in Public Participation, the Wisconsin Resource Protection Council, the Michigan Environmental Council, and others.

The upstream tailings dam method is designed to fail, environmental groups warn.  Industry experts consider the upstream method to be the least desirable type of tailings dam construction, due to its high risk of dam instability.

It is used because it is cheaper to construct, but is not the “Best Available Technology”. TMF dam walls are “raised” and each successive raise is partially supported by tailings, as depicted in the Back Forty TMF diagram above. This design is fundamentally unstable, and part of what makes the “upstream” construction method especially risky. The upstream dam method has been banned in several countries.

A POND IS NOT A POND, SAYS AQUILA?

Aquila’s public relations manager, Dan Blondeau, is trying to assure concerned citizens that the Back Forty’s upstream tailings dam won’t fail. In correspondence with filmmaker Mark Doremus, Blondeau claimed the “Back Forty tailings facility is NOT a pond and will NOT store liquid tailings.”

“I’d say Blondeau should read the permits,” said Kathleen Heideman of the Mining Action Group.

“The Back Forty tailings WILL be pumped as a wet slurry. These WILL be liquid tailings,” said Heideman. “The Back Forty tailings facility WILL contain a pond.”

The permit amendment makes it clear that wet tailings, deposited in the TMF structure, will be topped by a huge pond – water from the tailings:

  • “The decant pond expands from 100,000 cubic meters (m3) capacity to a maximum of 150,000 m3, then diminishes to 50,000 m3 at the end of operations”
  • “The height of the decant pond will rise as the TMF is constructed, with a maximum height of 36 meters at full build-out”

It may be hard to visualize the size of that pond, but “150,000 m3” (cubic meters) means the decant pond will be roughly six times larger than the Lincoln Memorial Reflecting Pool in Washington DC[1]

In the Aquila Back Forty Dam Safety Permit, the volume of “supernatant water” (floating on the surface of tailings) is predicted to be even larger – almost 40 million gallons:

  • “The maximum volume of supernatant water allowed in the (tailings) decant area will decrease with time from 0.15 Mm3 (39.6 Mgal) to 0.05 Mm3 (13.2 Mgal)”

40 million gallons of water – how big is that?

  • “A good-sized bath holds 50 gallons, so a million gallons would be 20,000 baths” [2]
    The Back Forty TDF pond will hold enough water to fill 800,000 baths.
  • “An Olympic-sized swimming pool holds 660,000 gallons of water” [3]
    The Back Forty TDF pond will hold enough water to fill 60 Olympic swimming pools.

Blondeau claimed the Back Forty tailings dam has a “maximum projected height of 130 feet” but the permit states a maximum projected height at closure of “42 meters” (138 feet tall). How tall?

  • A mature white pine tree averages 50 to 80 feet tall.
  • At 138 feet, the Back Forty tailings dam will be 55% taller than Marquette’s Landmark Inn (89 feet tall).

WILL ADDITIONAL TAILINGS STORAGE BE NEEDED?

The Back Forty tailings facility will cover 124 acres of the mine site.

“Blondeau fails to acknowledge the monstrous size of the Back Forty tailings dam,” said Heideman. “124 acres of tailings  – that’s like 50 city blocks, or 100 football fields. Tailings will cover an area 25 times larger than the Superior Dome at Northern Michigan University,” said Heideman.

And that may be just the beginning. The Mining Action Group has questioned whether Aquila is being honest in calling the Back Forty project a “7 year open pit mine” operation. Environmentalists believe that Aquila is planning an underground mining phase, although the permit applications deny that any underground mining will take place.

From 2015 until early 2018, Aquila Resources described the Back Forty project as having a “16 year life of mine and mill of 16.1 Mt of ore, including both open pit and underground mining.” This claim was repeated in Aquila’s press releases, investor statements, in presentations to the local community, and in correspondence with the Michigan DNR and the Menominee Indian Tribe of Wisconsin. In 2016, Aquila told their investors they would submit an underground permit once the open pit mine and milling facility were operating. Now the applicant is winking, telling investors that underground expansion will require “additional studies…”

Environmental groups claim that Aquila will pursue additional 9 years of underground mining, for a total of 16 years of mining. If true, the TMF will need to “accommodate” additional waste.

That’s the reason why mining companies build “upstream” tailings dams – the structure can “grow higher” if the mine needs to store more waste. TMF impoundments are frequently expanded through additional raises, which greatly increases the height of the dam walls and the total volume of waste rock and water contained within the structure. This habit of incremental raising greatly exacerbates the problem of instability, and has resulted in the catastrophic collapse of several tailings dams.

Strict impoundment loading limits were not defined in the Back Forty mine permit amendment application. It is reasonable and foreseeable to assume that Aquila has selected the controversial “upstream dam” method because it could allow for sequential expansion through raising of the dam wall (as pictured above) What may begin as a TMF with “three raises” can grow exponentially via incremental change, if permitting review is not environmentally protective. The tailings dams at Brumadinho and  Mount Polley were raised higher than originally designed, multiple times.

PERMANENT WASTE STORAGE

“Instead of talking about 100 year rainfall events, we need to be thinking about a 10,000-year lifespan,” said Heideman. “What are the real storm risks, the real seismic risks, the groundwater risks from failure of materials with a limited life, like the plastic liners underneath the TMF?”

When the risks are properly calculated for a 10,000-year lifetime – the figure often used for how long these tailings structures will need to maintain their integrity – experts say there is “a significant and disproportionate chance of failure for a tailings dam.” [4]

“TRIED, TESTED, AND PROVEN”?

Blondeau claims that the design of the Back Forty TMF “uses tried, tested, and proven engineering methods” because “similar facilities are already in operation at the Malartic Mine and the MusselWhite Mine in Canada, and the Neves Corvo Mine in Portugal.”

These mines  – Malartic, Musselwhite, and Neves Corvo – offer proof of nothing. “Thickened tailings” have been used for less than 10 years. The type of ore, tailings, and method of disposal varies widely – and the TMF designs are very different:

Malartic Mine

The Malartic Mine has only been operating since 2011. Malartic’s tailings are non-reactive. The thickened tailings have “solid material concentrations of between 65 and 70%” with “little or no free water. They form cone-shaped cells of various heights. The tailings are used to “cover acid-generating tailings” (to a depth of 3 meters), to remediate a previously abandoned tailings impoundment. To “avoid overflows, a sterile stone wall will be built around the various cells.” This is significantly different from the Back Forty TDF, where tailings will be highly reactive, tailings will decant a large quantity of water, and TMF walls will be built using reactive waste rock, not “sterile stone.” [5]

Musselwhite Mine

The Musselwhite Mine in Northwestern Ontario went into production in 1997 and “began thickened tailings disposal in May 2010.” “The cold climate presents a special challenge to operating the thickened tailings system as there is very little precedent experience.”  To reduce the likelihood of acid generating and metals leaching in the long term, the Musselwhite Mine announced plans “to remove the sulphide minerals from the tailings stream using a flotation plant.” Construction of a tailings thickener began in 2009; this was done to “to allow for an increased life span (capacity) of the current tailings management area. The thickener will reduce the water content in the tailings to approximately 74% solids to allow for stacking/mounding of the dry tailings…” [6] This is significantly different from the Back Forty TDF, where tailings are highly reactive, sulfides are not removed, and tailings are not “dry” or “stacked.” [7]

Neves Corvo Mine in Portugal

Owned by Lundin Mining, the Neves Corvo Mine opened in 1988. “Neves-Corvo has been developed as an underground operation, exploiting a number of polymetallic sulphide orebodies” with“tailings from the mine stored into a 190 hectare tailings management facility (“TMF”) bounded to the north by a rockfill embankment across a natural river valley. The facility was originally developed for subaqueous tailings deposition, but converted to thickened tailings deposition in 2010 “with an accompanying thickened tailings plant to increase the storage capacity.” At Neves Corvo, due to “multiple expansions of underground mining” and “expansion of the zinc processing plant and the volume of tailings produced, there will also be a need to expand the tailings thickening plant.” Additionally, underground “voids are being backfilled using a mixture of development rock, cement, and “paste fill (PF) made from cycloned process tailings.” This is different from the Back Forty TDF:  Neves Corvo uses an upstream tailings dam [8] but the disposal of thickened tailings (begun in 2010) has not solved their tailings storage problems:  new mining and “expansion of the zinc processing plant” resulted in yet more tailings; a new “Feasibility study for expanding the TMF… will provide a comprehensive tailing development scenario.”  

Read that again:  after 30 years of mining, Lundin is still trying to come up with a “comprehensive tailing development scenario” for Neves Corvo Mine? Ever-expanding operations come with demands “for additional tailings and mine waste rock storage at the Neves Corvo tailings storage facility, beyond the 2015 deposition design. Specifically an increase of up to 27 Mt of tailings and as much as 10 Mt of mine waste rock need to be accommodated…” [9]

That’s exactly what must be avoided at the Back Forty.

In all these mines, “thickened” tailings management was used to address “capacity problems” caused by expanding mining operations – suggesting these mines were not carefully planned, or failed to disclose future mining phases, resulting in undersized tailings storage. Mining companies treat TMFs like magic garbage bins, which must expand on demand to “accommodate” whatever amount of tailings and waste is produced.

FILLED WITH REACTIVE WASTE

The Back Forty is a polymetallic orebody. After processing, the finely ground tailings will contain hazardous metals cable of producing acid mine drainage and mobilizing metals through leaching. Geochemical modeling provided in Aquila’s 2015 application demonstrated that 77% of the waste rock and nearly all ore is reactive. The leachate produced by geochemical analysis of Back Forty tailing samples had an average pH of 2.5, very acidic.

All tailings held inside the TMF will be reactive, at risk of acid mine drainage. Recent tailings dam collapses, like the Brumadinho tailings dam in Brazil and the Mount Polley tailings dam in Canada, resulted in catastrophic environmental damages but their tailings were either inert or less reactive.

Blondeau downplayed the hazardous nature of the Back Forty tailings, comparing them to “toothpaste” and “drywall mud.”

In fact, the Back Forty’s tailings will be more toxic than either Brumadinho or Mount Polley.

“Mr. Blondeau’s comparison of the consistency of the dewatered tailings to ‘drywall mud’ or ‘toothpaste’ is not reassuring when you consider that with the ‘upstream’ design these mudlike materials end up being a structural part of the dam!” said Steve Garske of the Mining Action Group. “The remaining water in the tailings is what causes these dams to fail.”

Heideman calls the comparison with drywall mud and toothpaste “insulting.”

“There is no beneficial reuse. There is nothing domestic or healthy about it. These are toxic industrial tailings, full of mercury, lead, cancer-causing metals, acid-generating sulfides, residual sodium cyanide, chemical frothing reagents used in the milling process, and more. Failure of the Back Forty’s upstream tailings dam, whether it happens in five years or five hundred, would be an unspeakable environmental catastrophe.”

DESIGNED TO FAIL

Upstream mine tailings dams have been called “bombs waiting to explode” – and they are collapsing. The “failure rate of tailings dams has remained at roughly one failure every eight months… Over a 10,000-year lifespan (a figure often used for how long these structures will need to maintain their integrity) this implies a significant and disproportionate chance of failure for a tailings dam.” [10]

“This is really the mining industry’s dirty secret: upstream tailings dams are cheap, risky, and unstable,” said Heideman. “The State of Michigan cannot allow the Back Forty project to proceed as designed.”

 


NOTES

  1. https://www.bluebulbprojects.com/MeasureOfThings/results.php?comp=volume&unit=cm&amt=100000
  2. https://water.usgs.gov/edu/mgd.html
  3. https://en.wikipedia.org/wiki/Olympic-size_swimming_pool
  4. https://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=513583
  5. http://www.mining.com/malartic-gold-mine-class-action-lawsuit-trial-begins/
  6. http://csr.goldcorp.com/2010/docs/2009_musselwhite.pdf
  7. https://papers.acg.uwa.edu.au/p/1104_21_Kam/
  8. https://www.lundinmining.com/site/assets/files/3643/neves-corvo-technical-report.pdf
  9. https://papers.acg.uwa.edu.au/p/1504_40_Lopes/
  10. https://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=513583

 

 

New ​Report Finds Fault with Sulfide Mine’s Plans

MARQUETTE, MI — A new technical report from the Center for Science in Public Participation (CSP2) identifies serious faults with Aquila Resources’ Back Forty Mine Permit Amendment application, now under review by the Michigan Department of Environmental Quality.

The technical review of the Back Forty permit was conducted by Dr. Kendra Zamzow, an environmental geochemist, and Dr. David Chambers, an internationally-known expert on tailings dam safety. CSP2 analyzes mining applications in order to “provide objective research and technical advice to people impacted by mining.”

The Back Forty project proposes to excavate an 800 foot deep open-pit sulfide mine on the banks of the Menominee River, 100 feet from the water. Milling will also take place on-site, using cyanide leaching, mercury recovery, and flotation. Aquila claims to be “minimizing impacts” but the footprint of the facility has ballooned to 440 hectares (1087 acres), largely due to a larger tailings management facility. Most of the mine site would be covered by waste rock, ore storage, milling facilities and tailings storage. Environmental groups claim that the Back Forty’s environmental impacts could be significantly reduced by using feasible, common-sense alternatives — but Aquila has rejected these options.

Nearly all of the Back Forty rock is reactive – capable of producing Acid Mine Drainage (AMD) when exposed to air and water. AMD pollution devastates watersheds and lasts hundreds of years. Tailings and waste rock will be stored on-site during mining, and the tailings will remain on the surface forever. Aquila has told their investors they will pursue underground mining as a “second phase” of operations, but this is not acknowledged in any permit. Underground mining could extend the mine’s life from 7 years to 16 years, greatly magnifying the risks. During closure, the open pit will be backfilled with waste and tailings. Once this takes place, groundwater contaminated with AMD is predicted to seep into the river.

CSP2’s technical report evaluated the Back Forty mining permit, including updated environmental impacts, feasible alternative designs, financial assurances, and Aquila’s proposed use of an “upstream” tailings design, the same risky construction method that has resulted in catastrophic tailings dam failures around the world.

Key Findings of CSP2’s Technical Report

  • The Tailings Management Facility (TMF) is to be constructed using the upstream dam construction method, which is the least safe design. It also applies an underestimated seismic event to the construction design.
  • There are no details for the wastewater treatment plant (WWTP).
  • There is no information on how mercury from the retort will be stored or transported, or whether there is a facility to receive it.
  • Mercury emissions from the retort did not go into air deposition modeling.
  • Air deposition modeling suggests that Spring Lake currently meets mercury water quality standards, but will exceed (violate) them after mining begins. By using old data, Aquila Resources may be biasing the baseline high, underestimating the impact of emissions.
  • There are significant unexplained inconsistencies with the volume of chemical reagents, and the storage capacity for lime.
  • Recent data suggests upper groundwater layers flow faster than the data used in the groundwater model. The groundwater model was not updated, and may underestimate the volume of dewatering and impacts to wetlands.
  • Biological monitoring should include mussels, but currently that is not scheduled.
  • There are no plans to monitor surface water for metal concentrations, although sediment and mine discharge will be monitored for metals. Surface water metal analysis should be added.
  • Financial assurance is underestimated.

“This report only underscores the fact that the original Mining Permit should not have been granted,” said Ron Henriksen, spokesperson for the Front 40, which helped secure the review. “Aquila continues to provide inadequate applications with missing information. The DEQ should rescind this entire permit, have the applicant revise their mistakes, and refile it, properly formatted, with all material in one complete, organized application package.”

“These flawed permits and their environmental impacts are deeply interconnected. We urge the State of Michigan to hold a consolidated hearing on the Mine Permit Amendment, the Air Permit application, and the Dam Safety Permit application – an option allowed under Part 632 in cases where an applicant applies for multiple permits,” said Kathleen Heideman, a member of the Mining Action Group of the Upper Peninsula Environmental Group (UPEC).

“We need a thoughtful, consolidated hearing to discuss these permits,” said Heideman. “Nothing less than the future of the Menominee River is at stake.”

“The mine permitting process generates thousands of pages of data and arguments and choices. What is a grassroots environmental organization to make of it? Our logical minds can see where the loose ends are dangling. By hiring mining experts ourselves, we can identify those loose ends as areas of serious concern about this mining permit.  We can enter the discussion that would otherwise be dominated by agency staff, lawyers, and mining company engineers. Expert commentary gives us a louder and more credible voice,” said Jon Saari, a board member of the Upper Peninsula Environmental Coalition.

“CSP2’s expert review of Aquila Resources’ latest Back Forty mining permit application has exposed serious flaws in their mining layout and operational design. This includes their insistence on using the risky upstream dam construction for their tailings facility,” said Steve Garske, a member of the Mining Action Group of the Upper Peninsula Environmental Coalition. “If constructed as planned, this mine will literally be an accident waiting to happen.”

Technical review of the Back Forty Mine Permit Amendment was made possible by a collaborative effort of the Mining Action Group, the Front 40 Environmental Fight, the Coalition to Save the Menominee River, a 2019 grant from Freshwater Future’s Great Lakes Network, and a 2019 emergency mini-grant from the Western Mining Action Network.

Public Participation

The deadline for submitting written comments on the Aquila Back Forty Mine Permit Amendment permit has been extended until February 15, 2019 at 5pm (EST). Mail comments to Back Forty Mining Permit Amendment, MDEQ-OGMD, 1504 West Washington Street, Marquette, MI 49855, or email comments to DEQ-Mining-Comments@michigan.gov with “Back Forty Mining Permit Amendment” as the subject.

Learn More

 

CSP2 disputes claims in letter about Back Forty mine

Wednesday, January 30, 2019  – Eagle Herald

Dear Editor,

I recently received a copy of an editorial published in the EagleHerald, “Communications director says release was ‘misleading’,” by Nathan Conrad, communications director for the Natural Resource Development Association.

I am the president of the Center for Science in Public Participation (CSP2). I have agreed to review the application to construct a tailings dam at the proposed Back Forty mine, but as yet have not received the technical documents I need to perform this review. Nonetheless, Mr. Conrad decided to criticize CSP2 before I have done my analysis.

He said in the letter to the editor: “CSP2 is the same anti-mining group that reviewed a wetland permit last year for opponents of the Back Forty mine. Furthermore, the same local environmental groups opposed to mining previously hired CSP2 to review Eagle Mine’s permits.”

This is attacking the messenger, not the message. It is a logic of innuendo, and a smear tactic. The only factual information in this statement is that a report was done — not that the report was either objective or biased, or right or wrong, and why.

Mr. Conrad goes on to assert: “In 2015, it was made known CSP2 colluded with an “anti-mine coalition” and the Environmental Protection Agency (EPA) in an attempt to derail the Pebble Mine project in Alaska.”

This is not only false, but unless Mr. Conrad has factual evidence to substantiate this claim, which he doesn’t, it is a libelous statement.

CSP2 provides an objective analysis of the data — data that is typically paid for by, and collected by the mining industry. CSP2’s analysis and critiques are not based on who collected or paid for the data, it is an analysis of the data itself. If there is to be a criticism of our reports, then critique the report, not the reporter.

If, however, Conrad wants to insist that it is political agenda, or who one works for that counts, then who should be trusted, a scientist working for a nonprofit helping citizen groups, or a scientist employed with a for-profit company, paid by the mining industry?

David M. Chambers
Center for Science in Public Participation, Bozeman, Mont.

Writer disputes points, talks about permits

Tuesday, January 29, 2019 – Eagle Herald

Dear Editor,

In his recent letter to the EagleHerald (posted below), Nathan Conrad paints concerned citizens as “known anti-mining” “opponents” who are trying to “obstruct and mislead.” In fact, we’re local residents concerned about the Back Forty sulfide mine, which will destroy clean water and other natural resources. Unlike Conrad’s Natural Resource Development Association, we’re 100 percent volunteer — no paid staff, no lobbyists. We hired well-respected experts at The Center for Science in Public Participation (CSP2) to assist with the complex technical review of the proposed Back Forty mine permit.

Conrad’s letter made false statements, including:

  • “According to The Center for Science in Public Participation own website, since 2007, the organization has been providing technical support to a loose coalition of groups opposed to the proposed mine.” False. This refers to the Pebble Mine, not the Back Forty.
  •  “Furthermore, the same local environmental groups opposed to mining previously hired CSP2 to review Eagle Mine’s permits.” False.
  •  (Aquila) “received all state and federal permissions required for the construction and commencement of operations at the Back Forty Project.” False. Aquila’s permits are replete with unmet special conditions — incomplete or missing environmental studies, infrastructure designs, financial assurances, etc. No construction or operations can take place until all conditions are satisfied.

When Conrad said the mine received “four final permits” he meant:

  • Mining permit — defunct, in litigation
  • Air pollution permit — defunct, being modified
  • Wetland permit — wetland destruction, in litigation
  • NPDES permit — pollutant discharge to the Menominee River

Aquila rushed headlong in pursuit of these permits, desperate to meet investor deadlines to get more funding. But haste makes waste, as the saying goes. Aquila’s permits were shoddy and must be amended. A fifth permit is under review for the tailings dam, one of the mine’s riskiest features.

Mining and milling will obliterate this scenic area. The true riches of the place aren’t found underground, but in the flowing river, sturgeon, mussels, native plants, ancient garden beds, and the burial mounds belonging to ancestors of the Menominee people.

Lowered water quality. Lost wetlands. The industrialization of yet another wild place. These are the Back Forty’s permitted environmental impacts.

Aquila’s “commitment to clean mining” is totally meaningless. Millions of tons of reactive waste tailings raise the permanent threat of groundwater contamination or catastrophic dam failure. Contaminated waters from the pit will seep into the river. Air pollution — mercury, lead and other metals — will settle nearby and accumulate in lakes. This is how clean water is lost: Permit by permit, to a thousand cuts.

Did Conrad read the permits? “Clean mining” claims do not change the devastating facts of the Back Forty project. We look forward to CSP2’s technical review.

Kathleen Heideman
Mining Action Group of the Upper Peninsula Environmental Coalition, Houghton, Mich.

Responding to:

Communications director (**) says release was ‘misleading’

Tuesday, January 22, 2019 12:00 AM  Eagle Herald

Dear Editor,

A press release distributed by a known anti-mining group published in the EagleHerald Extra (“Environmental groups to fund technical review of permit amendments for Back Forty Mine,” Jan. 17, 2019) was grossly misleading and provides a disservice to your readers.

According to The Center for Science in Public Participation (CSP2)’s own website, since 2007, the organization has been “providing technical support to a loose coalition of groups opposed to the proposed mine.”

CSP2 is the same anti-mining group that reviewed a wetland permit last year for opponents of the Back Forty mine. Furthermore, the same local environmental groups opposed to mining previously hired CSP2 to review Eagle Mine’s permits.

In 2015, it was made known CSP2 colluded with an “anti-mine coalition” and the Environmental Protection Agency (EPA) in an attempt to derail the Pebble Mine project in Alaska.

CSP2 may claim it is independent from Mining Action Group, Front 40, and UPEC but the group is far from impartial. For the press release to suggest its “independent” is dubious at best. In fact, the press release clearly shows it has reached its conclusion before the “independent” review is conducted.

The fact of the matter is — despite anti-mining groups’ attempts to obstruct and mislead — Aquila Resources has been granted four of four final permits by Michigan’s Department of Environmental Quality. Because of Aquila’s commitment to clean mining, it has received all state and federal permissions required for the construction and commencement of operations at the Back Forty Project.

Nathan Conrad

Communications Director for the Natural Resource Development Association

**  In his letter to the editor of the Eagle Herald, Mr. Conrad identified himself as the “Communication Director for the Natural Resource Development Association” but failed to disclose that he is a registered lobbyist for AQUILLA RESOURCES, one of the “leading members” of the Natural Resource Development Association. Talk about misleading!

Aquila Back Forty Mine Permit Amendment – Public Comments of Al Gedicks

Public Comments of Al Gedicks, executive director, Wisconsin Resource Protection Council
DEQ Public Meeting in Stephenson, MI – January 9, 2019

TAILINGS DAM FAILURES

The proposed Back Forty tailings waste storage uses the “upstream” dam construction method. According to the 4 th World Landslide Forum in Slovenia in 2017, “Several examples of recent tailings dam failures involved dams constructed by the upstream method, where
the new embankments are founded on tailings, causing the dam to become progressively more dangerous as its height increases.” According to Aquila’s mine plan, waste rock will be used to build the embankment around the tailings dam.

Based upon the record of historical failures, two distinct failure mechanisms seem to be dominant. The first mechanism is related to the development of progressive failure in a weak soil layer in the dam foundation. Appendix A of the Golder Report states that the project site is typically covered with topsoil underlain by a variable thickness of silty sand overburden soil of very loose to loose relative density.

The second dominant failure mechanism is related to static or dynamic liquefaction of loose tailings material at a critical state. Static liquefaction is the sudden loss of strength when loose soil, typically granular material such as tailings sands, are loaded and cannot drain. Loading and deformation produce a tendency for the materials to contract and develop excessive pore pressure faster than drainage systems can relieve the pressure. Static or dynamic liquefaction of loose tailings may occur at a critical condition, where a rapid (undrained) small increase in the shear strain results in a large increase in pore pressure, reduced effective stresses and a dramatic reduction of shear strength. Typical for these types of failures is that they occur rapidly with no warning, so it is an extremely dangerous phenomenon. Although it is called static liquefaction, a triggering event usually causes the rapid strength loss.

There are many potential triggers, including:

  • vibrations from construction equipment
  • rise in water pressure in a slope
  • stress increase due to a dam raise
  • stress concentrations due to a higher dam
  • loss of horizontal confining stress due to lateral strains in
    the foundation or dam

Source: Klohn Crippen Berger, “Static Liquefaction and Strength Loss in Tailings Dams,” posted on April 11, 2018. Available at https://www.klohn.com/blog/static-liquefaction-strength-loss-tailings-dams/

Static liquefaction and strength loss of tailings dams due to undrained failure has become a major concern in tailings management following the Mariana, Brazil and Mount Polley
tailings dam failures. At both Mount Polley, British Columbia and the Samarco mine in Brazil, the companies’ failure to act on warnings and prepare for possible disasters points to an alarming corporate practice of putting production and profit ahead of safety concerns.

Source: Judith Marshall, “Tailings dam spills at Mount Polley and Mariana: Chronicles of Disasters Foretold,” Canadian Centre for Policy Alternatives, August 2018. Available at https://www.policyalternatives.ca/tailings-disasters

CAUSES OF TAILINGS DAM BREAKAGE

The causes of tailings dam breakage are numerous. Apart from construction problems, poor maintenance or unusual weather are cited in a review of tailings dam failures in Geotechnical News Magazine in December 2010.

Aquila’s amended permit application minimizes the potential for external erosion of the tailings dam from the runoff of rainwater by using 18-year-old data on the severity of storms. It is not sound science to predict the safety of tailings dam storage on such old data.

According to the chief scientist at Climate Central, “Across the board, the United States has seen an increase in the heaviest rainfall event, and the Midwest specifically has seen an increase of almost 40 percent.” In August 2018, in Wisconsin’s Coulee Region–and Vernon County in particular–was hammered by heavy rains that cause two dam failures and damaged at least five more dams.

The public needs information on the potential volume of tailings release, the chemical composition of the tailings release, and the flow of tailings release to the Menominee River and wetlands under both dam-break and dam-failure scenarios.

AQUILA’S FINANCIAL ASSURANCE PLAN

Aquila has proposed a financial assurance plan for the Back Forty Project that is clearly inadequate to administer reclamation, remediation, and post-closure monitoring. The indirect cost estimates for the Back Forty financial assurance are less than that recommended by most sources.

One of the often-quoted public sources of guidance is the U.S. Forest Service’s “Training Guide for Reclamation Board Estimation and Administration.” The Forest Service recommends indirect costs at a minimum of 39%, ranging up to 128% of the direct cost of reclamation and closure. The amount of indirect cost proposed for the Back Forty financial assurance is 10%. This amount is clearly inadequate.

Source: Dave Chambers, “Review of Aquila’s Back Forty mine proposal,” Center for Science in Public Participation, February 24, 2016.

Aquila’s total financial assurance cost estimate for the end of construction operating period and the Life of Mine (LOM) operating period is $130.5 million. Compare this with the $544 million financial assurance to protect taxpayers from future cleanup costs at Polymet’s proposed mine and processing site near Babbitt and Hoyt Lakes, Minnesota–if the company went bankrupt or couldn’t do the work itself.

The amount of financial assurance is calculated to cover the cost of closing and reclaiming the mine, in addition to long-term water treatment needed to meet state and federal pollution standards.

Source: Dan Kraker, Minnesota Public Radio, “Polymet offers state $544M if it couldn’t pay for mine cleanup,” December 15, 2017.

The calculation of direct cost for reclamation involves a significant amount of detailed analysis. Aquila can offer its estimate of the financial assurance, but it is the responsibility of the DEQ to carefully check these calculations for their accuracy. There is significant financial incentive for Aquila to make optimistic assumptions about the cost of individual items of the financial assurance, in order to keep these costs to a minimum. However, it is always less expensive for the mine proponent to conduct reclamation activities than it is for the DEQ to contract and oversee these same activities.

If the DEQ does not have the expertise internally to check the assumptions and calculations made by Aquila in its financial assurance calculations, then it should retain the services of a qualified contractor to review Aquila’s financial surety bond.

Such reviews can and often do result in millions of dollars in increases in the financial assurance, which is of major significance to the public, since this is a potential financial liability. After Minnesota’s review, Polymet’s new financial assurance plan provides about $200 million more than the initial estimate included in its first mine permit application.

ENVIRONMENTAL IMPACTS

In the 900 pages of Aquila’s Mining Permit Amendment Application, there is a systematic dismissal of the potential for pipeline spills, tailings spills, tailings impoundment failures, and other releases of hazardous materials. The economic and environmental costs of these releases are not covered in either state or federal financial assurance programs—even though they commonly occur at metallic sulfide mines.

In a recent report,* Earthworks reviewed state and federal documents and a federal database for fourteen copper-sulfide mines, representing 89% of copper production in 2010—the most recent data available from the U.S. Geological Survey. These mines provided a representative view of the types of environmental impacts resulting from the development of copper-sulfide deposits, focusing on pipeline spills, tailings failures and water collection and treatment failures.

The report found that:

  • ALL OF THE MINES (100%) experienced pipeline spills or other accidental releases.
  • At 13 of the 14 mines (92%), water collection and treatment systems failed to control contaminated mine seepage, resulting in significant water quality impacts.
  • Tailings spills have occurred at nine operations, and a partial failure of the tailings impoundment occurred at four out of fourteen mines (28%). The total costs for just 7 of these large failures was $3.8 BILLION DOLLARS, at an average cost of $543 million per failure.
  • These losses, according to dam committee reports and government accounts, are almost ALL the result of failure to follow accepted practice.

According to the report, these failures are a direct result of the increasing prevalence of tailings storage facilities with greater than a 5-million cubic meter total capacity—necessitated by lower grades of ore and the higher volumes of ore production required to attain or expand a given tonnage of finished product.

In Aquila’s mine permit application, they proposed to store 5.1 million cubic meters of tailings, thereby increasing the risk of a tailings spill, according to the scientific literature.

In Aquila’s amended application, they propose to store 4.9 million cubic meters of tailings, despite the increased size of the tailings dam. How is it physically possible to have a larger tailings dam with a smaller volume of tailings?

Regardless, whether it is 5.1 million cubic meters or 4.9 million cubic meters, the large volume of tailings poses a serious risk for a tailings dam failure—which is ENTIRELY OMITTED in Aquila’s amended permit application.

* Source: Earthworks, “U.S. Copper Porphry Mines: The Track Record of Water Quality Impacts Resulting from Pipeline Spills, Tailings Failures and Water Collection and Treatment Failures,” July 2012. Available at: https://www.earthworksaction.org/files/publications/Porphry_Copper_Mines_Track_Record __8-2012.pdf

Aquila’s amended application states that the project will generate a total of 61.56 million tons of waste, including 48.81 million tons of waste rock, 8.95 million tons of tailings, and 3.80 million tons of overburden. All of this waste must be safely stored and contained in the tailings storage facility in perpetuity. According to the International Commission on Large Dams: “Tailings facilities are probably the largest man-made structures on earth.” They also contain some of the most toxic metals that threaten human health–such as arsenic, lead, and mercury.

Aquila’s public statements about the Back Forty Project have admitted that “Mining worldwide hasn’t always effectively managed environmental impacts” and this has been unfortunate. However, according to Aquila, “Today’s practices and regulations are meant to address these issues.”

However, if we look at the evidence on catastrophic mine waste, a new study reveals that catastrophic mine waste failures are increasing in frequency, severity, and costs—all around the world. The study by Bowker and Chambers* found that nearly half of all recorded “serious failures” happened in modern times, between 1990 and 2010. It calculated an average cost of $543 million for the most serious spills, with some climbing well above $1.3 billion. Since 1990 a dozen spills even resulted in the loss of lives–over 380.

These losses, according to dam committee reports and government accounts, are almost all the result of failure to follow accepted practice. These failures are a direct result of the increasing prevalence of tailings storage facilities with greater than a 5-million cubic meter total capacity, necessitated by lower grades of ore and the higher volumes of ore production required to attain a given tonnage of finished product.

Aquila’s original plan was to store 5.1 million cubic meters of tailings. The amended application proposes to store 4.9 million cubic meters of tailings.

The study projects 11 very serious failures between 2010-2020, at a total unfundable public cost of $6 billion. “There is no organized industry attempt to cover these losses in a risk-management loss-prevention program, and no political jurisdiction issuing permits is large enough to prefund a low-frequency, high-consequence loss of this scale. The inevitable result is either ‘government pays,’ or the damages go uncompensated.”

Aquila’s tailings storage facility is a disaster waiting to happen.

Source: Risk, Public Liability & Economics of Tailings Storage Facility Failures by Lindsay Newland Bowker & David M. Chambers, Washington, D.C., Earthworks, 2015.

Aquila Back Forty Mine Permit Amendment – Public Comments by Andi Rich

Public Comments of Andi Rich, supporter of the Coalition to Save the Menominee River
DEQ Public Meeting in Stephenson, MI – January 9, 2019

Why are we being required to review amendments of such a large project with changes so extensive that they can only be described as a full rewrite?

It is not reasonable to expect the public to filter the already-complex documentation initially submitted, in addition to the exorbitant amount of changes, and I would like to make the common sense request that as this project no longer resembles the initially approved permitted project, that Aquila should be allowed to walk away from the initial permit; but, in order to obtain a valid permit for this entirely new project, they should re-submit their request as a new permit application. This is the only way to allow an organized, fair, and thorough review, unobscured by the tremendous new amount of documents to review.

Citing the 2012 Earthworks report: 100% of the fourteen mines studied experienced pipeline spills or other accidental releases, 92% had water collection and treatment systems that failed to control contaminated mine seepage, tailing spills occurred at nine of the operations, and a partial failure of the tailings impoundment occurred at four out of fourteen mines (over 25%). Total costs for just seven of these 16 large failures was $3.8 billion, at an average cost of $543 million per failure.

With an average $543 million price tag for errors, the EXPECTATION BY AQUILA that the DEQ review what basically amounts to a completely new permit request (but harder to follow), with innumerable chain reactions from each change, IS UNREALISTIC, since the likelihood of our community members and even trained professionals, such as yourselves, to complete this exorbitant task with any type of accuracy is not only unlikely, it is also unrealistic.

When small, fairly common errors that occurred in 100% of the sulfide mines reviewed by Earthworks come with an average price tag of millions of dollars, I submit that our community deserves a permit application that is far more comprehensive than this jumbled mess of changes. Our safety depends on it.

More Red Flags for Aquila: Enviro Groups Fund NEW Technical Review of Back Forty Sulfide Mine

FOR IMMEDIATE RELEASE — JOINT PRESS STATEMENT

 

STEPHENSON, MI — The Front 40 Environmental Group and the Mining Action Group (MAG) of the Upper Peninsula Environmental Coalition (UPEC) have secured a new independent technical review of the Aquila Back Forty Mine Permit Amendment application, to be completed by the Center for Science in Public Participation (CSP2). CSP2 analyzes mining applications in order to provide objective research and technical advice to people impacted by mining. Dr. Kendra Zamzow and Dr. David Chambers are conducting the review.

The Back Forty project proposes to excavate an 800’ deep open-pit sulfide mine on the banks of the Menominee River, 100’ from the water. Milling will take place on-site, using cyanide leaching and flotation. Most of the mine site will be covered by waste rock, ore storage areas, milling facilities and tailings storage. Aquila claims to be “minimizing impacts” but the footprint of the facility has ballooned to 440 hectares (1087 acres), largely due to a larger tailings management facility. Environmental groups claim that the Back Forty’s environmental impacts could be significantly reduced by using common-sense feasible alternatives — but Aquila Resources has rejected these options.

Nearly all of the Back Forty rock is reactive, or capable of producing Acid Mine Drainage (AMD) when exposed to air and water. AMD pollution devastates watersheds, and lasts hundreds of years. Tailings and waste rock will be stored on-site during mining, and the tailings will remain on the surface forever. Aquila has told their investors they will pursue underground mining as a “second phase” of operations, but this is not acknowledged in any permit. Underground mining would extend the mine’s life from 7 years to 16 years, greatly magnifying risks. During closure, the open pit will be backfilled with waste and tailings; as a result, AMD groundwater contamination is predicted to seep into the river.

CSP2’s review will consider changes to the Back Forty mining permit, including environmental impacts, feasible alternative designs for waste storage, transportation plans, remediation, financial assurances, and the proposed use of an “upstream” tailings design, a risky construction method that has resulted in catastrophic tailings impoundment failures. Dr. Chambers, an internationally-known expert on tailing basins, will review this aspect of the permit.

“The Back Forty mine will threaten freshwater resources and destroy important cultural resources belonging to the Menominee Indian Tribe of Wisconsin,” said Kathleen Heideman, a board member of the Upper Peninsula Environmental Coalition.

More than 120 concerned citizens, tribal members, environmental groups and others participated in the recent Michigan Department of Environmental Quality’s (MDEQ) public meeting, held on January 9th in Stephenson, MI. Many speakers expressed frustration over access to the permit files, including password errors, server problems,and  browser or operating system incompatibilities. In light of these problems, the MDEQ has been asked to grant a 30-day Extension of the Public Comment Deadline.

The Mining Action Group also requested a consolidated hearing process in order to discuss the Back Forty Mining Permit Amendment request, a modified Air Quality permit application, and a new Dam Safety permit application. “We need a thoughtful, consolidated hearing that will allow concerned citizens to discuss all of these interconnected permits,” said Heideman.

Technical review of the Back Forty Mine Permit Amendment is made possible by a collaborative effort of the Mining Action Group, the Front 40 Environmental Fight, the Coalition to Save the Menominee River, a 2019 grant from Freshwater Future’s Great Lakes Network, and a 2019 emergency mini-grant from the Western Mining Action Network.

PUBLIC PARTICIPATION

Comments on the Aquila Back Forty permit will be accepted until February 6th at 5pm (EST). Mail comments to Back Forty Mining Permit Amendment, MDEQ-OGMD, 1504 West Washington Street, Marquette, MI 49855, or email comments to DEQ-Mining-Comments@michigan.gov with “Back Forty Mining Permit Amendment” as the subject.

The MDEQ has been asked to extend the Public Comment deadline, but no decision has been announced. Please contact Melanie Humphrey for an update on the extension request:  906-250-7564, HUMPHREYM@michigan.gov

Instructions for reviewing the Back Forty permit materials were included in the MDEQ’s Public Notice: https://www.michigan.gov/documents/deq/deq-ogmd-mining-Back_Forty_mine_amendment-PublicMeetingNotice_1.9.2019_641172_7.pdf

Mission of the Mining Action Group
The UPEC Mining Action Group (MAG), formerly known as Save the Wild U.P., is a grassroots effort to defend the clean water and wild places of Michigan’s Upper Peninsula from the dangers of sulfide mining. Contact the Mining Action Group at info@savethewildup.org or call (906) 662-9987. Learn more about the UPEC Mining Action Group at miningactiongroup.org.

Mission of the Front 40 Environmental Fight
The Front 40 is a grassroots organization that was formed in early 2003 in response to the threat of a metallic mineral mine potentially being developed on the shores of the Menominee River in Lake Township, Michigan. It is the principal objective of the Front 40 Environmental Group to ensure that metallic sulfide mining operations are not allowed to adversely impact our rivers, lakes, groundwater and lands. Learn more about the Front 40 group: menomineeriver.com.

Aquila Back Forty Mine Permit Amendment – Public Comments of John Engel

DEQ Public Meeting in Stephenson, MI – January 9, 2019

My name is John Engel, a member of the Executive Committee of the John Muir Chapter of the Sierra Club and a retired Project Manager for a consulting engineering company.

The 632-mining permit amended environmental impact assessment Section 2.4.2 groundwater quality states: No known occurrence of contaminated groundwater on the project site was observed in the monitoring wells during the study.

Section 3.4.4 (Foth 2015b) of the environmental impact assessment describes the following mechanisms as potentially affecting groundwater quality.

  • A leak in the closure tailings facility liner, cap and cover system.

A March 11, 2015 publication, Impermeable Basal Structure – With Synthetic Liners by the Geological Survey of Finland states: There is little data available about the field performance of liner materials and the lifetime prediction is usually based only on material tests of the synthetics (including high stress, aggressive fluids, and elevated temperatures), which by no means guarantee the duration of the liners service life, too often causing unsatisfied lifetime predictions. (1)

Will the tailings cap and cover system withstand the increased frequency of severe weather events without eroding or collapsing? The liner system and monitoring technology has not been verified to withstand the test of time. Tailings and waste rock are reactive, creating sulfuric acid, heavy metals when exposed to oxygen and water. The reaction will occur for hundreds of years. When the tailings facility liner fails and the backfilled mine pit waters become acidic, the groundwater will contaminate the marshes, rivers, and streams, adjacent to the mine site. (2)

The tailing management facility is 127.8 acres and approximately 148 ft high containing 4.9 million cubic meters of tailings or approximately 356,000 loads in a 18-yard dump truck. The facility will contain an additional 5.9 million cubic meters of reactive waste rock, approximately 429,000 18-yard dump truck loads.

Who is going to be held responsible and pay for the removal of the waste rock and tailings from the mine site, years after the investors have received their money and Aquila Resources have closed the mine site?

The Sierra Club is very concerned about the Back 40 Mine Project causing catastrophic long-term environmental damage. The location of the mine, processing mill, and reactive tailings storage facility, minimizes the value and fails to protect the quality of the groundwater, including the aquatic life in the Menominee and Shaky Rivers. Environmental damage will affect the states of Michigan and Wisconsin, as well as, despoiling sacred cultural sites of the original home of the Menominee Indian Nation.

Speaking on behalf of the 3.5 million members and supporters of the National Sierra Club, including 150,000 members and supporters of the Michigan Chapter, we strongly oppose risky sulfide mining operations such as the Back 40 Mine!

 

 

References:

  1. Impermeable basal structure – with synthetic liners
    Latest update: 03.11.2015
    Mine Closure: Wastes and waste facilities
    Anna Tornivaara, Geological Survey of Finland, P.O. Box 1237, FI-70211 FINLAND:
    Anna Tornivaara of Geological Survey of Finland, Espoo (GTK) with expertise in: Geochemistry, Geology and Hydrogeology 03.11.2015
  2. Flambeau Mine: Water Contamination and Selective “Alternative Facts”
    Robert E. Moran, Ph.D. Michael-Moran Assoc., LLC Water Quality/Hydrogeology/Geochemistry Golden, Colorado, U.S.A. remwater@gmail.com remwater.org

Aquila Back Forty Mine Permit Amendment – Public Comments of Ron Henriksen

Testimony of Ron Henriksen for the Front 40 Environmental Group
DEQ Public Meeting in Stephenson, MI – January 9, 2019

The PERFECT PERMIT APPLICATION was supposedly filed by Aquila Resources with the MDEQ in November of 2015. A number of critical plans were not fully addressed along with inaccurate and inadequate models and test data. Many items were changed over the first year prior to the granting of a permit with many conditions.

Now a full three (3) years later, we find ourselves reviewing yet another version by way of these amendments which simply confirms that the public was correct in stating the original permit was flawed and incomplete. IF Aquila had completed the Feasibility Study PRIOR to submitting the permit application, these SIGNIFICANT amendments may not have been necessary. WHY are these amendments still written with terms such as “will be provided”; “must be obtained”; and “shall be determined”? Are the plans ever final?

How can this project ever be considered complete or be granted an EFFECTIVE status when there are still many unknown factors (yet to be determined)? WHY is there still missing data? Certainly Aquila must have some reasonable excuse that this information is still not being provided?

It would be appropriate to grant an extension for the review time for several reasons:

  1. After 16 years of trying to develop the potential project, there still seems to
    be a number of unresolved issues. The Front 40 along with other concerned
    groups have commissioned to have a technical review of this amendment.
  2. Access to the 904 pages of documents was not user-friendly. The Public
    cannot read or comment on that which they cannot find.
  3. The amendments were filed during the holidays when this material could
    just as easily have been filed in January of 2019 and filed as a complete
    proposal. Now they have added another 55 pages to the EIA; creating more
    review. Are there more items?
  4. Perhaps it would be beneficial to the DEQ and the public for the DEQ to
    rescind the entire permit application; have the applicant re-work and re-file it
    properly formatted – with all the data materials in one complete and organized
    application package.

 

Aquila Back Forty Mine Permit Amendment – Public Comments of Jon Saari

Testimony at DEQ Public Meeting in Stephenson, MI – January 9, 2019

My name is Jon Saari. I am a Board member of the Upper Peninsula Environmental Coalition, and a resident of Marquette. MI. I am opposed to approving the Mining Permit Amendments to the Aquila Back Forty project.

In my testimony for the wetlands permit hearing I focused on the exact arithmetic of impacts to wetlands, both direct and indirect; they totaled 28.39 acres of the 93 acres of wetlands on the mine site. We and our experts did not believe the company’s estimate, and indeed the number has since been revised upward to about 55 acres. We were told that any change in this number would force Aquila to start over. That hasn’t happened.

Instead of “aligning” the mining facilities to minimize the wetlands impact, Aquila and its engineers have introduced us to the concept of “feasibility design.” It seems to argue that if it costs the company more to construct a tailings pond safely or to protect wetlands, they need not do it. Feasibility, meaning money, determines the design.

This latest version of the mine plan greatly expands the mining facilities to the east. Approximately 222 acres have been added to the mine footprint, mainly it seems to increase capacity for tailings and waste rock. Where is the increased rock coming from? The size of the pit is roughly the same, so the company must be hedging its bets about the future of this mine. The life of the mine in this permit is seven years, but on the ground it seems to be anticipating an additional nine years of underground mining.

So the alignment in this new plan is preparing for a longer and deeper future mine. The requirement in the wetlands permit to seek the least damaging alternative to the destruction of 55 acres of wetlands fell by the wayside. As we argued in that hearing, relocating some facilities onto the uplands of the eastern area would have minimized that destruction. But this idea was dismissed; in the language of “feasibility design” it was not feasible due to transportation costs.

The company and its engineers plow ahead with their own logic. The Michigan DEQ has to fit all this complexity into its regulations. The third party in this contest is the public stakeholders — the native ancestors, the landowners, the river protectors, the environmental advocates. May they finally be listened to.