What are some of the issues concerning copper mining?

Source One:

http://www.greenspec.co.uk/building-design/copper-production-environmental-impact/

• Habitat destruction is one of the main issues associated with mining activity. Large areas of natural habitat are destroyed during mine construction and exploitation, forcing animals to leave the site.

• Animals can be poisoned directly by mine products and residuals. Bioaccumulation in the plants or the smaller organisms they eat can also lead to poisoning: horses, goats and sheep are exposed in certain areas to potentially toxic concentration of copper and lead in grass.

• They are fewer number of ants species in soil containing high copper levels, in the vicinity of a copper mine. If fewer ants are found, chances are great that other organisms leaving in the surrounding landscape are strongly affected as well by this high copper levels, since ants are a good environmental control: they live directly in the soil and are thus pretty sensitive to environmental disruption (Wikipedia)

• Surface Water pollution: Acid rock drainage occurs naturally within some environments as part of the rock weathering process but is exacerbated by large-scale earth disturbances characteristic of mining and other large construction activities, usually within rocks containing an abundance of sulfide minerals. The most commonly mined ore of copper, chalcopyrite, is itself a copper-iron-sulfide and occurs with a range of other sulfides. Thus, copper mines are often major culprits of acid mine drainage.’ ‘When the pH of acid mine drainage is raised past 3, either through contact with fresh water or neutralising minerals, previously soluble iron(III) ions precipitate as iron(III) hydroxide, a yellow-orange solid colloquially known as yellow boy. Other types of iron precipitates are possible, including iron oxides and oxyhydroxides. All these precipitates can discolor water and smother plant and animal life on the streambed, disrupting stream ecosystems’ (Wikipedia)

• Ground water pollution: Water in mines can contain heavy metals such as lead and cadmium which can leak into the local groundwater.

• Land degradation

• Deforestation

• Common ailments include respiratory illnesses such as asthma and tuberculosis as a result of inhalation of the silica dust particles resulting from the mining and processing of copper.  Miners in particular suffer from silicosis or pneumoconiosis.

• The smelting process can also create pollution. Smelting often produces large volumes of low concentration sulfur dioxide that is not worth further processing to remove the sulfur. Acid rain resulting from the combination of rain and SO2 can cause damage to crops, trees and buildings for many miles down-wind.

• Leaching solutions are typically regenerated and reused continuously for extended periods. On occasion, however, such during temporary or permanent closure, the solutions are disposed as wastes via land application or other means.

• High levels of copper can be harmful. Breathing high levels of copper can cause irritation of the nose and throat. Ingesting high levels of copper can cause nausea, vomiting, and diarrhea. Very-high doses of copper can cause damage to the liver and kidneys, and can even cause death. (U.S. Department of Health and Human Services, 2004

• Copper doesn’t break down in the environment, leading to its accumulation in plants and animals. Copper released into the environment usually attaches to particles made of organic matter, clay, soil, or sand. Copper compounds can break down and release free copper into the air, water, and foods.

• Elevated levels of copper are toxic in aquatic environments and may adversely affect fish, invertebrates, plants, and amphibians. Acute toxic effects may include mortality of organisms; chronic toxicity can result in reductions in survival, reproduction, and growth.  (EPA, 2008)

• Acute industrial exposure to copper fumes, dusts or mists can result in chronic copper poisoning.

• World production of copper amounts to 12 million tons a year and exploitable reserves are around 300 million tons. About 2 million tons a year are reclaimed by recycling. (source EPA)

• The US Geological Survey estimated that, as of 2013, there remained 3.5 billion metric tons of undiscovered copper resources worldwide in porphyry and sediment-hosted type deposits, two types which currently provide 80% of mined copper production. This was in addition to 2.1 billion metric tons of identified resources. Combined identified and estimated undiscovered copper resources were 5.6 billion metric tons, 306 times the 2013 global production of newly mined copper of 18.3 million metric tons. (Wikipedia)

• Usually found in combination with sulphur, iron, carbon and oxygen.

Sulfide copper minerals – bornite – chalcocite – chalcopyrite• Copper minerals are divided up into three groups: Primary or hypogene minerals found at great depths; Oxidised copper minerals commonly formed by copper sulfides exposed to erosion; Copper secondary sulfides formed from leaching of sulphides exposed near the earth’s surfaceThe top 5 copper-producing countries in 2013 (source USGS)

Chile: 5,700,000 tonnes China: 1,650,000 tonnes Peru: 1,300,000 tonnes USA:  1,220,000 tonnes Australia: 990,000 tonnes

The process for extracting copper involves a series of chemical, physical and electrochemical processes.Depending on whether an ore is sulfide or oxide, the process follows one of two routes.

Rocks are crushed in a series of crushers.  Sulfide ores are further reduced through a ‘wet grinding’ process that ensures a particle size suitable for the flotation process.

Sulfide ores and froth flotation: Sulfide ores are mixed with water and a surfacant creating a slurry. The slurry, when agitated causes the copper sulfide minerals to float at which point they are skimmed off the surface dried. The dried material is then sent to the smelter.

Oxide ores (and certain sulfide ores) are placed onto a leach pad and saturated with weak sulfuric acid solution that dissolves the copper mineral content. The resulting copper-bearing solution is collected and pumped to a solvent extraction plant.

Sulfide Ore: The dried copper concentrates are sent to the smelting operation where it is reduced and melted in several operations. At the end of this smelting process the copper is about 99% pure. After smelting, the 99% copper rich material is poured into molds as "anodes" using a casting wheel and transported to the plating house. In this form, they are ready for the next step, which involves dissolving and re-plating the copper to increase its purity level.

Oxide Ore: The copper-bearing solution is collected and pumped to the extraction plant where it is purified. It progresses through a number of steps that combine an organic solvent or sulfuric acid to the solution until the copper concentration is high enough for effective electro-plating. The copper-bearing solution, from the solvent extraction operations, is plated into pure copper cathodes using a process called solution exchange electrowinning (SX-EW). Stainless steel blanks are added to the plating tanks to act as cathodes and copper is plated onto them by electro-chemical deposition. It takes about a week before the

cathode is ready to be removed from the tank so the copper can be stripped off the blank. The cathodes are now 99.99% pure copper and ready for product manufacturing.

Waste rock is typically hauled from the mine site to waste dumps for disposal. Waste rock piles may have high permeability to both air and water. Oxygen and sulfide minerals may be contained in the dump. The quantity and composition of waste rock generated at mines vary greatly by site. This material can be classified as either oxide or sulfide, with varying solubilities, depending on the composition of the ore body. Sulfur-bearing minerals, such as pyrite and pyrrhotite, can oxidize to form sulfuric acid. Factors that influence acid generation by sulfide wastes include: (1) the amount and frequency of precipitation, (2) the design of the disposal unit, and (3) the neutralization potential of the rock. Constituents of concern for waste rock include sulfur-bearing minerals that may generate acid and leach metals contained in the ore body and surrounding rock. (Mining Industry Profile: Copper)

Tailings are generated during flotation. Tailings are made up of very fine host rock (i.e., gangue) and nonmetallic minerals separated from the values during beneficiation. The physical and chemical nature of tailings varies according to the ore characteristics and the beneficiation techniques used. Tailings are a slurry of fine-grained rock material and process water. Liquid is removed from the tailings slurry in thickeners and the thickened tailings are discharged to the tailings impoundment. Water is usually reclaimed from the thickeners and recirculated to the mill to be used in beneficiation and dust control (Mining Industry Profile: Copper)

The quantity of mine water generated at mines varies from site to site. The chemistry of mine water is dependent on the geochemistry of the ore body and the surrounding area. Water exposed to sulfur-bearing minerals in an oxidizing environment, such as an open pit or underground workings, may become acidified. This potential is greatly dependent on site-specific factors.

Barren solution (raffinate) is an acidic aqueous solution that has been stripped of copper but still has some carryover of the organic extraction/diluent used in the solvent extraction operation. The raffinate generated at hydrometallurgical plants is typically stored in ponds and recycled to the dump leaching operation. As a result, it does not become a waste until after the closure of the mine. Following mine closure, spent leaching solutions must be disposed of.

Energy:Primary copper production is a major activity in the mining sector. It is highly energy-intensive, ranking third in specific energy consumption (SEC) among the five major basic metals (aluminum, copper, iron, lead and zinc) . Open-pitmining                     0.021 MJ/ton             19-25%Milling                                   0.045           MJ/ton                                     40-52Smelting                               0.007 – 0.024            MJ/ton                        8-21Converting                            0.001 – 0.007            MJ/ton                        1-6Gas cleaning                        0.007– 0.009 MJ/ton                        8Electrorefining                      0.007  MJ/ton                                    6 Total                                      0.086 - 0.112            MJ/ton                       100 SOURCE: Charles H. Pitt and Milton E. Wadsworth, An Assessment of Energy Requirements in Proven and New Copper Processes report prepared for the U.S. Department of Energy, contract no EM-78 -S-07.1 743, 1980.Recycling & Reuse• Copper is 100% recyclable without loss of quality• Copper is the most recycled metal after iron and aluminium• Around 40% of the demand for copper within Europe is supplied from recycled copper.• Recycling a tonne of copper uses 20% of the energy that would be used to mine and extract the same copper.• The copper recycling process has much in common as that to extract it, but requires fewer steps. High-purity copper is melted in a furnace and then reduced; Low-purity copper is refined through electroplating in sulfuric acid.

Source Two:

http://blog.cowaninternational.com/2012/06/21/global-mining-reducing-minings-environmental-impact/

• In the USA, acid mine drainage has a significant impact on the environment. Around 10,500 miles of streams have been affected and half a million acres of land remain unrestored.

• Some organizations are developing practices with the intent to make the extraction of minerals safer for the environment.

o Clean Mining Alliance (CMA) aims to help make mining cleaner, help set international standards to facilitate cleaner mining technologies, showcase new emerging cleaner technologies in mining and educate its members and the wider community.

o Mining Association of Canada (MAC) has developed a set of principles and performance elements under the banner Towards Sustainable Mining (TSM). The principles developed in ‘collaboration with communities of interest and key stakeholders cover six criteria:

1. Tailings Management2. Energy and Greenhouse Gas Emissions Management3. Aboriginal and Community Outreach4. Crisis Management Planning5. Safety and Health6. Biodiversity Conservation

o The International Council on Mining and Metals also works to improve sustainable development performance in the global mining and metals industry.

o Canada’s Saskatchewan Eco Network recommends several ways to reduce mining’s environmental impacts including:

1. Increasing the efficiency of manufacturing processes ….2. Reduce mineral consumption.3. Improve environmental performance at mines.4. Introduce legislation and regulations to reduce the environmental impact of mining.5. Clean up abandoned mine sites. 6. Renewable energy will inevitably play a key role to reduce the impact of mining on the

environment.

Mining reportedly erodes more of the Earth’s surface each year than natural river erosion. For example, in excess of 220 tons of earth are excavated to produce just one ton of copper.

When mines fill with water, this becomes highly acidic. In the USA, acid mine drainage has a significant impact on the environment.

Third Source:https://www.copper.org/education/history/60centuries/industrial_age/itseffect.html

Its Effect on Copper MiningThe Industrial Revolution brought about a tremendous change in the production of copper and its alloys. In the first place, an insistent demand arose for more and better raw material. In 1586 Ulrich Fosse, a German who was working the Cumberland copper mines, boasted that he could smelt 560 tons of copper ore in forty weeks. The 17th and 18th Centuries saw a vast improvement in this rate of output, largely arising from a quicker removal of impurities from the ore. By 1717 the Landore Works at Swansea comprised three large buildings, one of which was devoted solely to calcining. There were also thirty smelting furnaces for copper, lead and silver, a refining house, a test house and other outbuildings. (20)

In 1794 the Mines Royal at Neath Abbey were smelting 230 tons of copper ore per week to give 18 tons of copper. They used thirty-eight furnaces which consumed 315 tons of coal in the operation. The presence of good coal, in fact, was one

of the reasons why the Swansea district became the centre of this industry; charcoal had been used right down to 1688 although as early as 1632 Edward Jorden discovered a new method of smelting by using pit coal, peat and turf as a fuel, and four years later Sir Philip Vernatt was granted a patent for the use of coal alone for that purpose.Swansea was also an excellent seaport and was accessible to ships from all parts of the world which could bring ore from mines abroad.During the 18th Century production in the nearby Cornish mines increased and a high output was sustained due to the introduction of steam pumps to remove the water from the diggings. This was the first use of steam power in mining and arose from the inventive mind of Thomas Newcomen, a Dartmouth blacksmith. Thus the Swansea district with its coal and commanding position became the greatest centre in the world of copper smelting and refining, a distinction which it retained until the latter part of the 19th Century. But a terrible price was paid; the local atmosphere in what had formerly been the beautiful green valleys became so foul with sulphurous fumes that it was said that if the Devil were to pass that way he would think he was going home. (21)

The cost of copper, in those days, was very great. In 1714 cake copper, unrefined, fetched £100 per ton, and plates as they came from the battery works cost £140 to £150 per ton. In 1694 Swedish copper, which was then regarded as high quality, cost £168 per ton. These figures, currency for currency, far exceed modern prices. On the other hand, the entire English output of English copper at that date was only about 100 tons per annum.20 ALEXANDER, W.O. Development of the Copper, Zinc and Brass Industries in Great Britain from A.D. 1500 to 1900 Murex Rev. (1955), 1, (15), p. 399.

Fourth source:https://www.lenntech.com/periodic/elements/cu.htm

CopperCopper is a reddish metal with a face-centered cubic crystalline structure. It reflects red and orange light and absorbs other frequencies in the visible spectrum, due to its band structure, so it as a nice reddish color. It is malleable, ductile, and an extremely good conductor of both heat and electricity. It is softer than zinc and can be polished to a bright finish. It is found in group Ib of the periodic table, together with silver and gold. Copper has low chemical reactivity. In moist air it slowly forms a greenish surface film called patina; this coating protects the metal from further attack.ApplicationsMost copper is used for electrical equipment (60%); construction, such as roofing and plumbing (20%); industrial machinery, such as heat exchangers (15%) and alloys (5%). The main long established copper alloys are bronze, brass (a copper-zinc alloy), copper-tin-zinc, which was strong enough to make guns and cannons, and was known as gun metal, copper and nickel, known as cupronickel, which was the preferred metal for low-denomination coins.Copper is ideal for electrical wiring because it is easily worked, can be drawn into fine wire and has a high electrical conductivity.Copper in the environmentCopper is a very common substance that occurs naturally in the environment and spreads through the environment through natural phenomena. Humans widely use copper. For instance it is applied in the industries and in agriculture. The production of copper has lifted over the last decades. Due to this, copper quantities in the environment have increased.The world's copper production is still rising. This basically means that more and more copper ends up in the environment. Rivers are depositing sludge on their banks that is contaminated with copper, due to the disposal of copper-containing wastewater. Copper enters the air, mainly through release during the combustion of fossil fuels. Copper in air will remain there for an eminent period of time, before it settles when it starts to rain. It will then end up mainly in soils. As a result soils may also contain large quantities of copper after copper from the air has settled.

Copper can be released into the environment by both natural sources and human activities. Examples of natural sources are wind-blown dust, decaying vegetation, forest fires and sea spray. A few examples of human activities that contribute to copper release have already been named. Other examples are mining, metal production, wood production and phosphate fertilizer production.Because copper is released both naturally and through human activity it is very widespread in the environment. Copper is often found near mines, industrial settings, landfills and waste disposals.Most copper compounds will settle and be bound to either water sediment or soil particles. Soluble copper compounds form the largest threat to human health. Usually water-soluble copper compounds occur in the environment after release through application in agriculture.World production of copper amounts to 12 million tons a year and exploitable reserves are around 300 million tons, which are expected to last for only another 25 years. About 2 million tons a year are reclaimed by recycling. Today copper is mined as major deposits in Chile, Indonesia, USA, Australia and Canada, which together account for around 80% of the world's copper. The main ore is a yellow copper-iron sulfide called chalcopyrite (CuFeS2).Health effects of copper

Routes of expositionCopper can be found in many kinds of food, in drinking water and in air. Because of that we absorb eminent quantities of copper each day by eating, drinking and breathing. The absorption of copper is necessary, because copper is a trace element that is essential for human health. Although humans can handle proportionally large concentrations of copper, too much copper can still cause eminent health problems.Copper concentrations in air are usually quite low, so that exposure to copper through breathing is negligible. But people that live near smelters that process copper ore into metal, do experience this kind of exposure.People that live in houses that still have copper plumbing are exposed to higher levels of copper than most people, because copper is released into their drinking water through corrosion of pipes.Occupational exposure to copper often occurs. In the working environment, copper contagion can lead to a flu-like condition known as metal fever. This condition will pass after two days and is caused by over sensitivity.EffectsLong-term exposure to copper can cause irritation of the nose, mouth and eyes and it causes headaches, stomachaches, dizziness, vomiting and diarrhea. Intentionally high uptakes of copper may cause liver and kidney damage and even death. Whether copper is carcinogenic has not been determined yet.

There are scientific articles that indicate a link between long-term exposure to high concentrations of copper and a decline in intelligence with young adolescents. Whether this should be of concern is a topic for further investigation.Industrial exposure to copper fumes, dusts, or mists may result in metal fume fever with atrophic changes in nasal mucous membranes. Chronic copper poisoning results in Wilson’s Disease, characterized by a hepatic cirrhosis, brain damage, demyelization, renal disease, and copper deposition in the cornea.

Environmental effects of copper

When copper ends up in soil it strongly attaches to organic matter and minerals. As a result it does not travel very far after release and it hardly ever enters groundwater. In surface water copper can travel great distances, either suspended on sludge particles or as free ions.Copper does not break down in the environment and because of that it can accumulate in plants and animals when it is found in soils. On copper-rich soils only a limited number of plants has a chance of survival. That is why there is not much plant diversity near copper-disposing factories. Due to the effects upon plants copper is a serious threat to the productions of farmlands. Copper can seriously influence the proceedings of certain farmlands, depending upon the acidity of the soil and the presence of organic matter. Despite of this, copper-containing manures are still applied.Copper can interrupt the activity in soils, as it negatively influences the activity of microorganisms and earthworms. The decomposition of organic matter may seriously slow down because of this.When the soils of farmland are polluted with copper, animals will absorb concentrations that are damaging to their health. Mainly sheep suffer a great deal from copper poisoning, because the effects of copper are manifesting at fairly low concentrations.

Source 5:http://www.timberjay.com/stories/mining-vs-water,12329

Mining vs. waterDunka site exposes breakdown in mine regulation

The Dunka Mine is located about three miles southest of Babbitt.

Posted Wednesday, October 7, 2015 4:44 pm

ATTACHMENTS MPCA responses 2.pdf

 MPCA responses to Timberjay questions.

Marshall Helmberger

SUPERIOR NATIONAL FOREST—As state and federal regulators work to finalize the environmental review on PolyMet Mining’s proposed NorthMet copper-nickel mining operation, impacts to water remain near the top of the list of concerns.

Unlike other mining in northeastern Minnesota, the ore that PolyMet proposes to mine is part of what’s known as the Duluth Complex, a zone of sulfide-bearing rock that stretches from southeastern St. Louis County in an arc through central Lake and Cook counties. The sulfide rock contains copper, nickel, platinum and other valuable metals, but it is also known to leach acid, metals, sulfates, and other potentially toxic chemicals when exposed to air and water. To critics, this process, known as acid rock drainage, has come to symbolize the dangers associated with the mining of sulfide ores.

While NorthMet would be the first copper-nickel mine in northeastern Minnesota, it wouldn’t be the first time that a significant amount of low-grade sulfide-bearing rock was exposed as part of a mining operation in the region.

For 30 years, beginning in 1964, LTV Steel operated the Dunka Mine, located just three miles southeast of Babbitt. While LTV mined taconite at the site, a layer of the Duluth Complex lay on top of the iron ore along one end of the mine. In exposing the iron ore, LTV removed an estimated 50 million tons of sulfide-bearing rock that it stockpiled at the mine site, where it remains to this day.

When state regulators and PolyMet officials say they can mitigate the risks of acid rock drainage at NorthMet, Dunka provides a good example of the challenges and the economic and political pressures that regulators could face when proposals outlined in the NorthMet Supplemental Draft Environmental Impact Statement, or SDEIS meet realities on the ground.

At first glance, the story of Dunka looks encouraging. When state regulators realized back in the 1970s that the stockpiled ore was leaching highly toxic levels of copper, nickel, and other contaminants into a nearby creek that drained into Birch Lake’s Bob Bay, they took action. After conducting experiments at the site to better understand the degree of acid drainage actually taking place at Dunka and how best to contain it, officials with the Department of Natural Resources and the Pollution Control Agency required LTV to cap the top of the sulfide-bearing waste rock piles. They also required the company to install a water treatment plant and a series of engineered wetlands that were designed to capture metals and other contaminants.

And even environmentalists, like Paula Maccabee, an attorney for WaterLegacy who has fought hard for better enforcement of pollution rules at Minnesota mines, acknowledge that the work, completed mostly in the 1990s, reduced to some degree the level of toxic metals being discharged from the Dunka site. Indeed, an analysis conducted by the DNR in 2000 found that the capping of the sulfide rock stockpiles, by itself, reduced runoff by 55 percent and decreased nickel discharges by 82 percent.

However, as Maccabee points out, the water treatment plant built in the 1980s has been closed for decades and existing manmade wetlands, by themselves, still do not bring Dunka’s discharge in compliance with Minnesota water quality standards.

Even so, Richard Clark, of the Minnesota Pollution Control Agency’s Metallic Mining sector, states that Cliffs Natural Resources, which assumed ownership of Dunka after acquiring LTV assets following the company’s 2001 bankruptcy, has been in consistent compliance with the terms of its wastewater permit for Dunka.

A review of monitoring data as well as Cliffs’ wastewater permit by the Timberjay shows that both Maccabee and Clark are right. Cliffs has complied with its permit, yet its discharges don’t comply with water quality standards. In fact, the mine’s discharge regularly fails to meet water quality standards for several contaminants, including nickel, sulfates, and hardness, often by significant amounts.

These two seemingly incongruous facts are at the heart of what former state regulator Bruce Johnson sees as a fundamental breakdown in Minnesota’s regulatory process as it pertains to metallic mining. Cliffs can both violate water quality rules at Dunka and simultaneously meet the terms of its wastewater permit for Dunka, issued by the MPCA in 2000, because the permit includes no effluent limits in most cases. For most of the mine’s discharge, Cliffs’ permit only requires that the company monitor the pollution and file monthly reports with the MPCA.

That might be a surprise to most members of the general public, but it’s all too common according to Johnson, a biologist by training who spent decades working for the MPCA and the Minnesota Department of Natural Resources. Johnson was one of the lead DNR researchers on the 1970s-era copper-nickel study and he was involved in the development of the remediation plan for the Dunka Mine, so he’s as knowledgeable as anyone in the state about the science and the regulatory history of Dunka. According to Johnson, permits like the one currently regulating Dunka, which only require companies to monitor their pollution output and report it to the MPCA, do little to protect water quality and it’s one of the reasons he’s grown disenchanted with the state of environmental regulation in Minnesota. Johnson and his wife Maureen, herself a chemist by training who worked for the MPCA for years to clean up Superfund sites in Minnesota, both now serve as volunteer science advisors for Maccabee’s WaterLegacy. “We’re spending millions of dollars funding the MPCA,” said Johnson. “I think the public would be surprised at what’s going on.”

Maccabee said she was stunned when Johnson first explained to her what was happening to the state’s regulatory process, particularly as it relates to mining. She said the current permitting process for the state’s mines is focused primarily on protecting mining companies from legal liability for their pollution, not on protecting the environment. “A permit like we see for Dunka protects the company even if their discharges violate water quality standards,” she

said. “If they put it in the permit that all they have to do is monitor, then they don’t have to comply with the water quality rules.”

Clark acknowledges that Cliffs complies with its permit simply by monitoring and reporting its pollution discharges, but he says the data that Cliffs is collecting will help the agency as it works towards the issuance of a new permit.

Maccabee says that’s slim comfort considering that Cliffs’ current permit for Dunka expired a decade ago. And, at this point, agency officials say that they have no timeline for when a new draft permit might be proposed, much less when a final permit might ultimately be approved.

One thing, however, is certain. It’s going to take years. And it may never happen at all.

In the meantime, says Maccabee, the old permits provide Cliffs with legal protection, helping to keep the courts and the public from weighing in on behalf of clean water.

It’s just such situations, repeated across the Iron Range, that prompted WaterLegacy to petition the Environmental Protection Agency earlier this year to rescind the MPCA’s regulatory authority over the mining industry. Maccabee, in WaterLegacy’s petition, noted that virtually every mine on the Iron Range is operating on expired permits, in some cases with permits that have been expired for a quarter century. In those cases, companies are allowed to operate under rules that date back in many cases to the 1970s or 80s, before Congress updated the Clean Water Act in the 1990s.

Routine violations of standards

Because the MPCA requires Cliffs to provide monthly reports of their discharges from various points in and around the Dunka Mine, the actual effluent levels are publicly available. And even though capping of the waste rock stockpiles has significantly reduced the flow of metals like copper and nickel, monitoring reports show that discharges of those metals, particularly nickel, still routinely exceed a number of the limits written in state law and enforced under federal law. The mine includes seven known surface discharge points and most violate a number of water quality standards, often by significant amounts.

One of the worst is a discharge point labeled SD-009, located about midway along the mine’s southeast flank. According to the discharge monitoring reports that Cliffs routinely files with the MPCA, SD-009 routinely discharges water into the environment that would be in gross violation of state water quality standards for metals like copper and nickel, says Johnson, if the MPCA followed state and federal rules.

The water from SD-009 always exceeds standards for other pollution parameters, says Johnson, including hardness and conductivity, sometimes by as much as four times the allowable limits under either federal or state rules. Sulfate discharges are extremely high as well, averaging approximately 1,800 milligrams per liter (mg/l), but reading as high as 2,450 mg/l at times. That compares to the 10 mg/l sulfate standard currently in state rules for wild rice waters, a list that includes Birch Lake. The MPCA has since proposed a flexible sulfate standard for wild rice waters, but even if this proposal were adopted, it is highly unlikely that such high levels of sulfate would ever be allowed.

The MPCA, back in 2000, issued Cliffs a permit variance that allows the company to continue to discharge excess pollutants from SD-009 and a second point, known as SD-008. The permit and the variance both expired in 2005, but under permitting rules the mine can continue discharging under the old variance until its application for a new permit is acted upon by the MPCA.

The effects of the contaminant discharges at Dunka are apparent beyond the mine itself. Most of the mine’s contaminants discharge into Unnamed Creek, a natural stream that flows north to the southern tip of Birch Lake’s Bob Bay. Cliffs maintains a monitoring point, known as SW-001, at the mouth of the creek, where it enters Bob Bay, which is located about a mile downstream of the mine. While the dilution of the mine’s discharge by other uncontaminated runoff in the Unnamed Creek watershed helps reduce the contaminate concentration, the water entering Bob Bay is still far from meeting water quality standards under state and federal law. The monitoring reports filed by Cliffs show routine violations for nickel, hardness, conductivity and sulfates. Sulfate levels in the water entering Bob Bay have run as high at 1,840 mg/l per liter according to the reports.

The monitoring reports show some of the highest pollution readings during the winter months, and Johnson said two factors account for that trend. For one, stream flow is generally lowest during winter, which means there’s less water to dilute the steady discharge of contaminants that do escape the mine site. In addition, engineered wetlands at the

site that are supposed to capture contaminants do not function during the winter, according to Johnson, which means the mine’s discharges are released essentially untreated. The MPCA acknowledges the higher pollutant concentrations in winter, and responded by writing allowances for the higher discharges into Cliff’s permit variance.

Calcium also

a concern

The monitoring reports also show very high levels of calcium in the mine’s discharge, and some of that may be attributable to the engineered wetland, which uses limestone as a way to reduce the toxicity of metals, like copper. While calcium is not typically considered a serious pollutant by itself, the recent spread of invasive mollusks, such as zebra mussels, into lakes across Minnesota, has raised concerns about calcium levels, particularly for lakes north of the Laurentian Divide, where traditionally low calcium levels are believed to provide a natural protection against the survival of zebra mussels. Like most shellfish, zebra mussels require sufficient calcium in order to grow their protective shells. In most Minnesota lakes, natural calcium comes from limestone deposits formed in ancient seabeds. But the last glaciers scraped the Canadian Shield nearly bare of limestone, leaving little calcium behind. Research on the mollusks show that they require calcium levels of at least 20-25 mg/l in order to mature and reproduce. Most lakes in northern St. Louis and Lake counties fall well below that level, which may be one reason zebra mussels haven’t proven to be a problem in Canadian Shield lakes in Minnesota, at least so far.

Yet monitoring reports from 2013-2014 show that the water entering Bob Bay at SW-001 contains calcium ranging from a low of 30.6 mg/l to a high of 405 mg/l, with an average reading of approximately 100 mg/l. Whether that discharge has raised the calcium levels in Bob Bay or elsewhere in Birch Lake isn’t known, since the MPCA hasn’t tested the waters of the bay since the 1980s.

Impacts to aquatic environment

The question remains, however, whether the mine’s discharges are negatively affecting the aquatic environment. The MPCA’s Clark says there’s little sign of it. “The most recent biological monitoring for the Dunka site suggests a healthy aquatic system in Unnamed Creek,” he said. As part of their permit, Cliffs is required to undertake biological assessments of the aquatic life in Unnamed Creek, and Clark maintains those assessments indicate the presence of pollution intolerant species, like caddisflies.  “These measures suggest an appropriately healthy and diverse population of aquatic insects is present in Unnamed Creek,” said Clark.

Johnson strongly disputes that claim, noting that the only way to adequately determine the health of a creek is to compare it with other un-impacted streams in the area. Clark acknowledges that the MPCA doesn’t require Cliffs to assess aquatic life in other nearby streams, which, according to Johnson, makes any conclusions derived from Cliffs’ sampling suspect.

Johnson notes that state researchers did undertake such comparisons as part of the 1970s-era copper-nickel study, and those comparisons demonstrated at the time that the diversity of aquatic insects in Unnamed Creek (which was already receiving Dunka discharges) was more than 40 percent less than in unpolluted streams in the vicinity.

Among more sensitive families and genera of aquatic insects, the comparison found even greater impacts. The diversity of mayflies, for example, was reduced from the average of 11 different genera in neighboring streams, to just four in Unnamed Creek, a reduction of 64 percent. Such dramatic impacts to aquatic species violates the intent of the Clean Water Act, said Johnson. Federal rules indicate that receiving streams should maintain at least 95 percent of their species diversity.

In the 1970s, DNR researchers speculated that discharges from mine dewatering might have contributed to the disappearance of a number of species of more sensitive invertebrates in Unnamed Creek. But, according to Johnson, more recent data gathered by Cliffs, suggests it’s the ongoing contaminant discharge from waste rock runoff that’s causing the problem.

While Cliffs’ studies suggest there’s been no further reduction in species diversity in Unnamed Creek in recent years, Johnson said there should be evidence of actual recovery if the pollution problem was under control. So far, he notes, there’s no sign of that.

As for the caddisflies cited by Clark, Johnson notes that the copper-nickel study found them to be less sensitive to pollution than other insect varieties living in the area.

The MPCA does cite other evidence, including bio-assays, that agency officials believe points to lower levels of contaminants coming from the mine. Bio-assays are essentially experiments in which researchers add increasing concentrations of water from a tested lake or stream— in this case, Unnamed Creek— to a sample of uncontaminated water, to determine at what level the conditions might prove toxic to certain aquatic insects or minnows, like fatheads, known to be sensitive to pollution. Cliffs is required to conduct such bioassays on a regular schedule as part of its current permit and, to date, Clark explains, only one of 11 such tests run since 2012 indicated a level of toxicity harmful to certain stream organisms. And even that test passed when run a second time, notes Clark. Meanwhile, none of the tests indicated toxicity to fathead minnows, a fish species known to be sensitive to pollution.

Johnson takes issue with those findings as well. He notes that when one of the bio-assays showed toxicity last summer, the testing company re-ran the test using water with a higher level of hardness, about 200 mg/l. Johnson said that makes a difference, since increased hardness makes metals like copper and nickel less toxic. He said the tests should be using water with the level of hardness found in Birch Lake, which is the receiving water for contaminants in Unnamed Creek. “Hardness in Birch Lake is about 46 milligrams per liter,” said Johnson. “According to the rules, the hardness should be based on natural conditions.” He calls the bio-assays, as conducted by Cliffs, “strategic advocacy, rather than science.”

Perhaps the larger question is whether the discharges, particularly the very high levels of sulfates, are affecting Bob Bay or Birch Lake as a whole. Research conducted for the state’s copper-nickel study in the 1970s, showed that fish and clams in Bob Bay exhibited very high levels of copper and nickel, although there was some evidence those levels may have been higher than normal even prior to mining at Dunka.

In addition, other more recent research, including studies on the Iron Range, suggest a strong connection between sulfate levels and the conversion of elemental mercury into the more highly toxic methyl mercury, which is responsible for fish consumption advisories on many lakes in northeastern Minnesota. Sulfate discharges from Dunka into Bob Bay are among the highest on the Iron Range. But despite these well-documented excesses, Clark says he’s unaware of any sampling of water or fish tissues in Bob Bay, at least by state officials, since the initial state remediation work back in the 1980s.

Who pays for

pollution?

The state’s mining industry has fought for years for relief from some of Minnesota’s environmental laws, which are among the strictest in the country— at least on paper. Mining company representatives and their political supporters argue that the cost of cleaning up some of the industry’s longstanding pollution problems is too high in an era of intense global competition in the iron ore industry.

Such political pressure has, more than once, stood in the way of enforcement of clean water rules on the state’s mining industry. Indeed, earlier this year, the Legislature, led by the Iron Range delegation, blocked the MPCA from issuing a draft permit for U.S. Steel’s Minntac tailings basin after company officials told top state officials they wouldn’t accept enforcement of the standard as written.

While political pressure is one way that companies can avoid the cost of environmental clean-up, bankruptcy is another. LTV’s 2001 bankruptcy left the clean-up of Dunka in a legal limbo until Cliffs Natural Resources purchased LTV’s northeastern Minnesota mining property in later that year.

But Cliffs is facing extreme financial challenges of its own given a high debt load and the recent plunge in iron ore prices. The company’s stock has fallen dramatically in the past four years, from a high of $99.86 in July of 2011, to just $2.75 a share this past week. Industry analysts have been speculating for months about a possible bankruptcy of the heavily indebted company.

Given the company’s financial difficulties, there’s reason to believe that the MPCA will continue to delay any action on a new permit. The MPCA and Cliffs can avoid compliance with the federal Clean Water Act at present, because the company is operating under expired permits that were originally issued prior to enactment of current clean water laws and rules. But those rules require that any new permit that the MPCA issues, must come into compliance with current standards— and that would almost certainly require a major new investment in pollution control facilities at Dunka. MPCA’s Clark notes that the current wastewater treatment plant at Dunka isn’t designed to address all of the documented pollution at the site, so a new facility would likely be required. Reducing sulfate levels, in particular,

would almost certainly require construction of a reverse osmosis facility, a water treatment method that is expensive to build and comes with ongoing operational costs. Would Cliffs, which inherited the pollution problems at Dunka, be willing to invest millions of dollars in such a clean-up effort? So far, neither the Legislature nor regulatory agencies in Minnesota have shown a willingness to force the issue against a politically-powerful mining industry.

Maccabee says the state needs to show it can truly regulate the taconite industry before it can credibly undertake a new and environmentally risky form of mining in the region. “Minnesota regulators need to act now and require a clean-up of Dunka mine pollution,” Maccabee said. “At least as important, Minnesota needs to learn the lessons of the Dunka mine project before embarking on copper-nickel mining in the Duluth Complex. Bankruptcy, volatile prices and the undue political influence of the mining industry all increase the risk of long-term violations of water quality standards.”

Cliffs Natural Resources was provided a draft of this story in advance and offered an opportunity to comment. The company did not respond.