DNR report: It is scientific and historical and relies heavily on documented studies from over 200 sources. I copied and pasted some highlights. It goes through the history, science, and geology of mining in WI, health risks and monitoring, socioeconomic considerations, monitoring with some laws thrown in for good measure. (The pagination is from the pdf.)
Pages 1-3 Table of contents
Aluminum is of particular interest, as it is abundant in the Ironwood formation and has been linked to fish mortality in acidified waters.
Historically, mercury emissions to the atmosphere were considered to be widely dispersed. Recent studies suggest, however, that local and regional deposition is more important than previously thought.
(My note: see impaired waters and outstanding waters in Iron County via this link. http://dnr.wi.gov/topic/impairedwaters/2012ir_iwlist.html
5. Asbestosform grunerite present
Organic compounds. While potential pollutants associated with the ore and waste rock are typically of greater concern due to the large volume of these materials processed, a number of fuel, lubricants, solvents, and process chemicals are also used on site, and may potentially be present in stormwater or process water outfalls.
6. SPECIFIC CONSIDERATIONS (This is excellent. Science!)
Based on the information presented in this report, baseline and ongoing environmental monitoring at a taconite mining operation…
continuous monitoring of surface and groundwater flows and elevations, etc.
7. History of mining in WI. (Quick historical review.)
8. Tyler’s Fork (prospect; 1890 and 1902-1903)
The most significant is the Penokee Deposit, approximately defined by the locations of historical mines in the district (Figure 1), with the area of most interest being located in the west-central portion of the range in the vicinity of the former Berkshire Mine. Marsden (1978) described these reserves as “the largest in Wisconsin and one of the more important undeveloped iron ore reserves of the United States.” He estimated total reserves in this region to be 3.7 billion metric tons of crude ore with a 32% weight recovery. About 75% of this ore is located in Ashland County. This ore is magnetite taconite, with a crude iron content of 20-35%. Gogebic Taconite, LLC has recently expressed interest in developing a surface mine at this location, with initial operations to be located between Mellen and Upson.
9. At least three additional magnetite taconite deposits with production potential exist in Ashland and Iron Counties (Marsden 1978). These are, from east to west, the Pine Lake deposit (estimated 206 million tons of crude ore with 27% weight recovery) the Agenda deposit (estimated 160 million tons of crude ore with 28% weight recovery), and the Butternut deposit (estimated 53 million tons of crude ore with a 29% weight recovery). A mine was planned at the Butternut deposit by the Ashland Mining Company in the late 1950s (Kohn 1958), but never opened. Some additional exploration was carried out in the region throughout the 20th century, with rock from at least one site (near Moose Lake in Iron County, drilled by American Can Company) containing 20-31% iron (USGS 2005).
10. In some areas within the Lake Superior-type iron formations, geologic processes concentrated the iron into relatively soft hematite-rich zones that were especially high-grade economic iron ores. These zones are referred to as “natural ore” and were the target of much of the early mining in the Lake Superior-type iron deposits. The ore zones were relatively small in comparison to the larger, harder, lower-grade taconite deposits they occur within. Since the zones of natural ore were small and discontinuous, the mining of these deposits was accomplished in relatively small surface pits and in underground workings. Much of the natural ore was depleted by the time underground iron mining ended in 1967 in the Penokee-Gogebic Range. Since that time, techniques have been developed to mine and process the larger, harder, lower-grade taconite deposits which are the source of nearly all iron ore in the world today. The taconite requires beneficiation (Section 1.3), typically being concentrated into taconite pellets prior to shipping, unlike the original high-grade natural ores which were shipped directly from the mines to steel mills.
12. An accurate understanding of the mineralogy and geochemistry of the ore deposits and adjacent rocks is necessary to determine if asbestiform minerals are present, to evaluate the acid-
13. generating and neutralizing potential of the rocks, and to determine what elements may be mobilized during weathering of waste rock piles (Section 2.2).
Lake Superior-type iron formations have prominent bedding defined by variations in mineralogy of adjacent beds and parallel planes of weakness. The bedding is typically either planar or wavy on a relatively small scale, but in either case constitutes an important structural feature that influences the stability of mine workings and act as preferential groundwater flow paths. In most of the iron districts of Wisconsin the rocks have been deformed so that originally horizontal bedding dips into the Earth, often very steeply. This dip angle influences the amount of potential ore rock that is near the surface and the amount that is more difficult to access, which in turn influences the amount of overburden rock that would end up as waste during mining. In open-pit mining, progressively more overburden waste rock must be removed as the mine advances downward. Additionally, the angle of dip influences the stability of slopes in and around a mine.
Geology of Penokee Range!
15. 1.3. THE TACONITE MINING PROCESS
The mining and processing of taconite differs considerably from the largely underground, high-grade iron ore mines that defined iron mining in the Lake Superior region prior to the mid-20th century. Taconite operations consist of two major processes, extraction and beneficiation. Extraction consists of drilling and blasting the ore and overburden. Beneficiation is the process of concentrating and pelletizing the ore. Taconite operations typically consist of a mine pit, waste rock and tailings disposal areas, and processing plants and associated facilities.
16. Info on blasting and taconite operations at Tilden and Empire mines in Ishpeming, MI
Magnetic separation info…..
17. chemicals, flotation… figure explaning the process. (Much more complicated that putting a magnet to rock.)
18. Taconite mining and processing requires the use and management of a large quantity of water. The mine pit must typically be dewatered below the depth of the groundwater table, and runoff from mining and processing areas must be managed. Beneficiation processes require a large amount of water – ore and tailings are typically transported and treated in slurry throughout most of the process, and additional water is required for emissions control devices.
Picture of a tailings basin from MN.
19. Dry stacking is an alternate tailings disposal technique under discussion for projects that have been proposed in Wisconsin (Olivio 2013). In this method, tailings are dewatered using vacuum filtration, then transported to a storage area and compacted in a “dry stack”. While more expensive than conventional tailings disposal, this method has the advantages of requiring a smaller footprint and a reduced potential for contamination of water resources (Davies and Rice 2004; Davies 2011).
The final step in a taconite mining project is reclamation. Land areas (e.g., tailings disposal basins) can be covered and revegetated (e.g., Applied Ecological Services 2008). Areas of the mine pit can be refilled with waste rock, or, following the cessation of dewatering, it can be left to fill with water, forming an artificial lake. The former Jackson County iron mine (Figure 2) is the only example of a reclaimed open-pit taconite mine in Wisconsin.
20. 2. ENVIRONMENTAL AND ECOLOGICAL CONSIDERATIONS
Because a large taconite deposit located in the Gogebic District of Ashland and Iron counties (Section 1) is currently being evaluated for a mine, this section of the report is written to be particularly relevant to water, land, and air resources within that region of the state. Six watersheds with a total surface area of ~1300 square miles transect the Gogebic Range in Wisconsin and drain to Lake Superior (Table 1; Figure 9). Collectively these watersheds contain ~600 lakes and 200 streams spanning ~1000 miles. Sixty-six of the water bodies are classified as Outstanding Resource Waters (ORW) or Exceptional Resource Waters (ERW). Many of the streams support excellent trout fisheries. The watersheds are heavily forested with northern hardwoods and mixed conifers, and wetlands are abundant.
21. map of watershed
FIGURE 9. MAJOR WATERSHEDS ADJACENT TO THE PENOKEE-GOGEBIC IRON RANGE (PGIR) IN NORTHERN WISCONSIN. LAKE SUPERIOR AT TOP OF MAP.
Open-pit taconite mining has the potential to alter the flows and storage of surface waters and groundwaters. For example, given the elongated nature of the iron deposits that extend through parts of the adjacent watersheds in the Gogebic Range, a large mining pit could span multiple watersheds transporting water from one to another (Adams 1994). An elongated mine pit could receive groundwater input as simultaneous seepage from two or more watersheds, while dewatering of the pit might create discharge to only one. Leaving “saddles” of land in mine pits situated along watershed divides has been proposed to separate flows (Herr and Gleason 2007).
Taconite mine development proceeds in a series of steps that can sequentially affect different elements of the hydrologic budget (Figure 10). The first step would likely involve removal of trees and other vegetation from the future pit site, processing sites, access roads and service areas. As a result, rates of evapotranspiration would be expected to decline, and water yield would be expected to increase (cf. Hornbeck et al. 1993). Owing to the relatively steep topography and shallow regolith overlying low permeability bedrock in the PGIR, groundwater recharge prior to disturbance is probably low – as evidenced by the abundance of wetlands and small streams draining the area. After the forest cover is removed, surface runoff and the erosional transport of disturbed soils will increase, especially during storm events.
22. FIGURE 10. SIMPLIFIED DIAGRAM OF POTENTIAL HYDROLOGIC ALTERATIONS ASSOCIATED WITH THE VARIOUS STAGES OF A TACONITE MINING OPERATION.
During active mining operations, the mine pit functions as a hydrologic sink receiving groundwater inflow and storm water. Due to the relatively low transmissivity of the bedrock that characterize much of the PGIR, subsurface flow into the mine workings is expected to occur largely via fractures (Stuart et al. 1954; Adams 1994). Groundwater and direct precipitation inputs to the pit must be pumped out (mine dewatering), often at a rate of several thousand gallons per minute (Adams 1994). Dewatering can create a large cone of depression, lowering groundwater elevations around the pit (Stuart et al. 1954). Operations can utilize some or all of the pit water in beneficiation and pellet manufacturing, or it may be discharged to surface waters. In the latter case, some or all the surface runoff and infiltration that is “lost” to the pit footprint is replaced by this flow. Additional surface discharges (e.g., stormwater, treated wastewater) may exist as well.
Following the end of active mining operations, the mine pit may be left to fill with water, creating an artificial lake (e.g., Lake Wazee, Figure 2). If mine water was being discharged to surface features during operation, the cessation of dewatering can produce a shift in downstream flows and/or water levels. The time required for the pit to fill completely with water is dependent on pit size and the specific hydrology of the site, but abandoned pits in Minnesota have been predicted to require between 5 and 20 years to reach capacity (Adams 1994; Adams et al. 2004). As the pit fills, the difference in elevation between the newly forming lake and the surrounding water table decreases, resulting in decreased groundwater inflow.
24. HYDROLOGICAL MONITORING AND MODELING
To quantify any alterations to surface and groundwater resources, hydrology would ideally be thoroughly characterized prior to any large-scale mining operations.
2.2. POTENTIAL POLLUTANTS
This section describes pollutants of concern when considering the environmental and ecological impact of a taconite mining operation. This is not meant to be an exhaustive list of potential pollutants from such an operation, but rather focuses on those that are of particular concern considering the unique nature of open-pit taconite mining and the locations in Wisconsin in which it is likely to occur.
25. ACID MINE DRAINAGE (AMD)
Acid mine drainage (AMD) is a phenomenon commonly associated with mining of deposits that contain metal sulfide minerals (e.g., Nordstrom 2011). Pyrite and other sulfide minerals are stable under reducing conditions deep underground but are unstable and undergo relatively rapid chemical weathering when exposed to oxygen, water, and microorganisms near the Earth’s surface (Edwards et al. 2000). Through several reaction steps, pyrite reacts with oxygen and water to create sulfate ions and ferric iron ions, releasing protons in the process (e.g. Langmuir 1997). A commonly written reaction pathway is the oxidation of pyrite (FeS2), a non-magnetic iron mineral that co-occurs with magnetic forms such as magnetite (the iron oxide of primary interest in taconite mining):
FeS2 + 15/4O2 +7/2H20 → Fe(OH)3(s) +2H2SO4 (1)
Equation 1 oversimplifies the processes that can occur can under environmental conditions, but it illustrates how strong acid (H2SO4) can be generated as a byproduct of mining activity in the presence of metal sulfides. The reaction shown in equation 1 slows down at very low pH, but the proliferation of iron-oxidizing micro-organisms can speed it up again.
Hanna and Lapakko (2012) conducted a site-intensive investigation of sulfate export from waste rock at a former taconite mine at the eastern end of the Biwabik Iron Formation in MN using a combination of field and laboratory methods.
Given the findings and magnitude of sulfate release rates in the nearby Biwabik Iron Formation, it would be prudent to conduct site-specific investigations of sulfate release prior to mining in the PGIR. Samples from representative cores and engineering estimates of waste rock generation should be considered.
FIGURE 11. AVERAGE CONCENTRATIONS OF SULFATE IN THE ST. LOUIS RIVER WATERSHED OF NORTHWESTERN MINNESOTA (FROM BAVIN AND BERNDT, 2008)
28. MERCURY AND METHYLMERCURY
Mercury emissions and deposition
Mercury is a component of gas emissions from the heat curing of taconite pellets (Galbreath 2005). Studies at taconite processing facilities in Minnesota have shown that mercury is released from magnetite during the production of taconite pellets (Berndt and Engesser 2005). Recent emission inventories indicate that taconite mining and processing are the largest source of airborne mercury within the Lake Superior basin (Figure 12), and most of the taconite-related Hg emissions are associated with mining activity in northeastern Minnesota. The Minnesota Pollution Control Agency (MPCA) estimates that nine taconite facilities in this region emit a combined total of roughly 257 kg of Hg annually into the Lake Superior airshed as a result of taconite processing (Table 3). This represents 20% of total mercury emitted statewide (Berndt 2003), and current efforts in Minnesota seek to substantially reduce taconite-related mercury emissions (e.g., Benner 2008; Benson et al. 2012a; 2012b, Berndt 2008; Schlager et al. 2012). For comparison, Wisconsin Hg emissions from the four counties within the Lake Superior basin (Ashland, Bayfield, Iron, Vilas) totaled ~18 kg for 2012 (WDNR Air Management Hg Inventory data). ).
FIGURE 12. PERCENTAGE OF MERCURY RELEASES FROM DIFFERENT SECTORS IN THE LAKE SUPERIOR BASIN. SOURCE: LAKE SUPERIOR BINATIONAL PROGRAM 2012.
p.30 Mercury in the environment
Mercury contamination of fisheries in northern WI is well documented, and a region-wide public health advisory cautions people about the consumption of native fish (Section 3.3). There are similar concerns about the effects of mercury contamination on loons and other piscivorous wildlife in the region (Evers et al., 2011). Mercury is one of the few toxic elements (along with selenium, discussed below) known to biomagnify in aquatic foodwebs.
p.31 figure…aquatic mercury cycle in the environment
p. 32 FIGURE 14. THEORETICAL RELATIONSHIP BETWEEN MERCURY METHYLATION RATE (MMR) AND TWO KEY SUBSTRATES, INORGANIC MERCURY AND SULFATE (SOURCE: WATRAS ET AL., 2006).
p. 33 Quantitative predictions of mercury fate and transport should consider:
Mercury present in surface waters used during processing, both dissolved and that present in suspended sediment.
Mercury present in groundwater used in processing.
The range, distribution, and chemical form of mercury present in mined strata, as determined from core samples.
The range of mercury present in tailings.
Mercury present in runoff waters from tailings stockpiles and in waters of retention ponds.
Mercury present in green taconite pellets.
Mercury predicted or measured in stack emissions, followed by estimates of the proportion deposited locally vs. that entering the global atmosphere.
Selenium (Se), a nonmetallic element is an important trace nutrient in animals but a potential toxin at higher concentrations. Selenium pollution results from a number of human activities, including coal burning and mining (Lemly 2004). Selenium has geochemical behavior similar to that of sulfur, so it is commonly present in small amounts in pyrite.
Selenium is highly bioaccumulative. Oxidation and methylation in sediments renders Se available for biotic uptake, and is introduced into the food chain by rooted plants, benthic invertebrates, and bottom-feeding fish (Lemly and Smith 1987).
p. 34 While Wisconsin does not currently have a standard for acute selenium toxicity, the Michigan acute aquatic life standard is 120 μg/L. The Wisconsin human threshold criterion for public water supplies is 50 μg/L.
While selenium contamination is commonly associated with sulfide mining, and is also a major concern in areas impacted by mountaintop coal mining (Palmer et al. 2010), selenium contamination has also recently been discovered at the Tilden and Empire taconite mines on the Marquette range in northern Michigan (MDEQ 2009; 2010). Extensive sampling in the vicinity of these mines found many exceedances of the 5 μg/L chronic criterion in surface waters. The acute criterion (120 μg/L) was not exceeded in streams or lakes, but was exceeded in a seep coming out of a reclaimed waste rock pile. Selenium concentrations in sediments were measured as high as 39 mg/kg; a maximum of 2 mg/kg has been recommended as protective of bioaccumulative risk (MDEQ 2009). Fish tissue concentrations were measured at levels well in excess of the EPA criterion near the mines as well (MDEQ 2009; 2010). Interestingly, although the two mines are directly adjacent to one another, selenium concentrations in waste rock seeps at the Empire mine are two orders of magnitude greater than those from waste rock seeps at the Tilden mine (MDEQ 2009), suggesting spatial heterogeneity in the distribution of selenium in ore bodies. Given the scale of open-pit taconite mines, therefore, the absence of selenium at one location in the mine pit does not necessarily imply that it is not present elsewhere.
p.35 MINERAL FIBERS
“Asbestos” is the generic name for the silicate materials chrysotile, actinolite, amosite, anthophyllite, crocidolite, and tremolite (NTP 2011). Extensive use of these materials in industrial applications and materials began in the late nineteenth century and peaked in the mid-1970s. Asbestos is now recognized as a serious human health hazard (Section 3.1), and therefore its use and production has been greatly reduced. Asbestiform minerals form under special geologic conditions characterized by folding, faulting, shearing, and dilation; these deformations can also create other, non-asbestiform fibrous minerals (Ross et al. 2008).
Grunerite, an iron-rich amphibole, sometimes occurs with a fibrous crystal habit. This asbestiform grunerite, amosite, has especially slender crystals with a length:width aspect ratio of more 5:1, and is a known hazard linked to mesothelioma (e.g., Walton 1982).
The metamorphosed iron formations in Wisconsin commonly contain amphibole minerals. Grunerite is present in iron formations of the Black River Falls District, the Florence District, and locally in the Penokee-Gogebic District in Wisconsin. In the Penokee-Gogebic District grunerite is known to occur where the Ironwood Formation has been contact metamorphosed by igneous intrusions (Schmidt 1980), although there are no published studies of the aspect ratio or possible health effects of the grunerite in this district.
p.36 OTHER METALS OF CONCERN
Many of the transition elements have geochemical behavior similar to that of iron and therefore are commonly present in trace amounts in iron oxide and iron sulfide minerals. Magnetite commonly contains Mg, Ti, V, Cr, Mn, Co, Ni, Cu, Hg, and Zn. Pyrite commonly contains Ni, Co, As, Cu, Zn, Ag, Au, Tl, Se, and V. The concentration of these metals varies within each deposit and the fate of the ions during taconite processing and waste rock storage would depend on the beneficiation processing and on the geochemical and microbiologic processes acting on the rock after being mined.
The weathering of minerals that contain plant nutrient ions can contribute to eutrophication in surface water.
SUSPENDED AND DISSOLVED SOLIDS
Fine-grained mineral particles that become suspended in moving water are a common issue in surface water at sites where sediment and soil is disturbed or fine-grained crushed rock is produced.
Mining operations require a great deal of heavy machinery, and therefore utilize a large quantity of fuel, lubricants, solvents, etc. Fuel oil is also commonly used along with ammonium nitrate fertilizer for blasting. In operations where chemical flotation is employed, a variety of organic surfactants are typically used in the process (see Section 1.3). Any organic compounds being utilized in a mining operation should be monitored for in surface and groundwater, especially at any storm and process water outfalls.
p.37 2.3. AQUATIC ECOLOGY
Species-level effects of pollution seldom occur in isolation; any changes in the community structure can resonate through the food web as changes in the primary producers influence the primary and secondary consumers which in turn can impact the fish community. Ecological evidence of mining-related pollution can often be found in the composition of the algae and macroinvertebrates.
Periphyton (i.e., benthic algae) have been shown to be sensitive to elevated metals concentrations both in situ and in laboratory settings.
Macroinvertebrates are also sensitive to pollution from heavy metals, acid mine drainage, and increased sediment loads (Freund and Petty 2007, Bruns 2005, Poulton et al. 2010).
p.38 3. HUMAN HEALTH CONSIDERATIONS
Taconite mine tailings and waste contain components having well-documented toxic properties (Plumlee and Morman 2011). These may include, depending upon the ore formation, mercury and other metals, asbestos and other mineral fibers, arsenates, sulfates, and silicate dusts. In most cases, the documented incidence of toxicity is to on-site workers or to the public living very near to poorly-managed operations.
Risk to the public off-site is dependent upon the off-site presence of toxicants, via an appropriate exposure pathway, at concentrations sufficient to cause harm from either a short term (acute) or long-term (chronic) duration. The exposure pathway could consist of changes to local air quality (inhalation), changes to surface- or ground- drinking water sources, direct contact via contaminated surface waters, or direct contact to contaminated soils or stockpiles. Risk to the public could also follow an indirect route of environmental impacts resulting in exposure to toxicants in food, as well as loss of livelihood (e.g., subsistence needs such as wild rice and fishing, loss of tourism, etc.).
3.1. HEALTH RISKS RELATED TO AIR QUALITY
Particulate matter (PM) is a term for microscopic solids in the form of inhalable aerosols. PM may be from various dust or combustion sources. PM also forms in the atmosphere from condensation of atmospherically transformed volatiles, and may be transported great distances once formed or emitted. PM is of public health significance due to the small and inhalable size, varying chemical reactivity and toxicity, and their potential to be transported in the atmosphere.
…with particles less than 4-10 μm diameter being of concern due to the potential for this size range to reach the bronchiolar and alveolar depth of the lungs. "The largest source of PM from taconite ore mines is traffic on unpaved haul roads.
Asbestos is considered a human carcinogen by the U.S. Department of Health and Human Services (DHHS), the U.S. EPA, and the International Agency for Research on Cancer (IARC) (ATSDR 2001), causing respiratory-tract cancer, mesothelioma of the lung and abdominal cavity, and other cancers (NTP, 2011).
p.39 The assessment of a proposed mine site should include steps to protect both workers and public health by preventing dispersion and conducting confirmation monitoring. Confirmation monitoring should particularly emphasize the protection and reassurance of nearby communities.
p.40 As has been discussed since the first NE cancer report (MCSS [Minnesota Cancer Surveillance System], 1997), the large excess among males is consistent with an occupational exposure. Most of this excess appears attributable to two large and unique industries in NE Minnesota – iron ore mining and processing and the manufacturing of asbestos-containing ceiling tiles (Conwed Corporation plant in Carlton County). Workers in both industries experienced potential exposures to commercial asbestos, although the role of other mineral dusts in the taconite industry remains under investigation. As described further below, due to previous efforts to identify workers employed in these industries and to the statewide cancer registry, it has been possible to compare these records and ascertain to what extent mesothelioma cases in NE Minnesota (or anywhere else in the state) were previously employed in these industries. Some 43 of the 58 mesothelioma cases among miners, and 23 of the 25 cases among former Conwed workers were residing in NE Minnesota at the time of diagnosis. Since three cases worked in both industries, at least 63 male cases, or 82% of the excess cases among males in NE are attributable to these industries.
p. 40 3.2. HEALTH RISKS RELATED TO DRINKING WATER QUALITY
Soluble substances in stored waste rock, tailings, or tailings impoundments have the potential to affect ground or surface drinking water supplies if not properly managed. Acid formation is a concern if waste rock and tailings from taconite mining contain metal sulfides (section 2.2).
Although this section is concerned with Public Health, acid formation has related effects on ecosystems. These include both direct pH effects, and indirect effects caused by enhancing the introduction, through solubilization, of mineral and cationic toxicants into aquatic systems. From the public health perspective, the greatest concern would be the potential for the pH-enhanced alteration of drinking water supplies, with emphasis on unhealthy concentrations of metals in drinking water. The effect metals have on drinking water varies with the specific contaminant, and may range from acute or chronic toxic concentrations to aesthetic effects on taste or appearance that render water unpalatable. Although metals vary in their mechanism of toxicity, one shared feature is environmental or biological persistence.
p.41 If significant sulfide minerals are present, aqueous sulfate (sulfuric acid) formed primarily from weathered pyrite (see section 2.2) can drive low-pH conditions in tailings impoundments, surface runoff, and infiltrated runoff that enhances solubility and leaching of metals waste rock and wastewater impoundments.
Protection of Groundwater/Drinking water. To assess the potential for groundwater impacts to private and municipal drinking water supplies, a complete profile of the leachable mineral content of representative samples of the ore and waste materials that might be generated as part of a mining operation is required. Prior to commencement of mining activities at a new site, it is important to establish a thorough baseline profile of potentially affected groundwater and drinking water aquifers.
The ore removal and processing facility should have a preparedness plan for unplanned spills of process chemicals, including, but not limited to fuel, flotation chemicals, surfactants, acids, ore wash, and suspension fluids. The preparedness plan should have specific contingencies to prevent groundwater and surface water contamination in the event of a spill.
Much of what is currently known about leachable materials generated from taconite mining has come from studies of surface water and groundwater around “pit lakes” formed within old or abandoned mine sites such as the Mesabi Nugget mine near Hoyt Lakes-Aurora MN, where manganese and arsenopyrite have been identified as contaminants of concern
The pit lakes tend to be in remote areas away from exposure routes to the public, but such impacts to groundwater should be considered with respect to land reclamation and reuse. For new mining sites, detailed watershed, groundwater, and well use maps are useful tools for assessing impacts, and should be among the information needed to review a mine permit application.
Since selenium, depending upon the dose, is both an essential nutrient and a toxicant, understanding intake boundaries are appropriate.
Small amounts of asbestos are sometimes present in drinking water from various sources including natural deposits, asbestos in mine waste, or asbestos in cement pipes and filters
p.43 3.3. POTENTIAL IMPACTS ON FOOD SAFETY AND AVAILABILITY
MERCURY IN FISH
It is recommended that consumption of fish caught from waters statewide be restricted according to the DNR safe-eating guidelines, and exceptions (e.g., stricter guidelines) are in place for numerous lakes throughout northern Wisconsin due to higher levels of mercury in fish from these waters.
WILD RICE Wild rice is an important component of aquatic communities in parts of Minnesota, particularly northern Minnesota. It provides food for waterfowl, and shelter for animals and fish. Wild rice is also a very important cultural resource to many Minnesotans, and is economically important to those who harvest and market wild rice.
4.1. SOCIOCULTURAL CONSIDERATIONS
Richards and Brod (2004) investigated how rural communities confront development proposals that involve uncertain risks. Specifically, they investigated community support (differentiating community leaders from residents) for a gold cyanide process (GCP) mine in Montana. They conclude with a recommendation that rural communities facing projects characterized by new and unfamiliar technology should approach these developments as “new species of trouble (Erickson, 1994) that can be more fully understood through case comparisons.”
p.45…..introducing technical or industrial activities (e.g., wind farms or uranium drilling in Sweden or a taconite mine in Wisconsin) to such an environment could be appraised as threatening.
METHODS OF SOCIAL INQUIRY
This section briefly identifies methods which could be called upon for exploring the sociocultural aspects of mining in Wisconsin.
A single discussion is rarely sufficient; the approach typically requires the conduct of multiple groups in order to discover potentially meaningful trends across the groups and differences between the groups (e.g., focus groups in north Wisconsin community could include a group of long-time residents, new transplants from urban areas, members of environmental groups, members of hunting and fishing groups)..
In-depth personal interviews
Like a focus group, in-depth personal interviews generate narrative rather than numerical data. Although results may reflect the attitudes and opinions of a community atlarge, their strength is providing deeper understanding from information-rich informants.
p. 49 4.2. ECONOMICS
Section 4.1 discusses how individuals perceive and react to projects such as iron mining. The economic issues discussed here are at more of a system level, where individual perceptions matter less than the overall patterns of behavior. However, individual perceptions can strongly influence or even dominate a system, particularly in a small economic system like a rural community. Furthermore, perceptions of economic impacts can influence people’s opinions and behaviors about a project.
The first point to understand is that the duration of mine construction and operations influences economic effects.
Second, the amount of commercial activity generated by mining is limited by the total revenue obtainable from use of the ore body.
p. 50 Third, the effects of a mine on the regional economy depend in part on the relative capacity of the region. For instance, a mining operation will need labor, housing, equipment, local transportation, and similar inputs. If the region’s ability to supply those inputs is limited, the mine’s local impacts will also be limited.
Mining operations that constitute a large fraction of the regional economy have a proportionally large negative effect when mine operations end.
Fourth, it is important to distinguish commercial activity from economic development.
Finally, it is also important to distinguish commercial activity from externalities associated with the mine (see below for definition and discussion). By their nature, externalities come in a wide variety of types and sizes. Two of particular relevance to mining are human health effects and environmental damage from pollution. Because these effects are not accounted for in any market transaction involving the mining operation, they require additional effort to assess.
p. 51 45
Common Topics in Mining Economics
This document reflects the following economic topics:
Context: Locations of proposed mine and neighboring municipalities and counties. Trends in regional population, demographics, employment, personal income, sizes of commercial sectors.
Project Description: Physical size, duration, phases, etc. Ore body value, gross sales expectations, employment needs, ownership structures, etc.
Linkages: Local shares of project ownership; equipment and materials supply; and labor supply. Input-Output structure of the local economy; local economic impacts of the project. Major infrastructure requirements such as power and rail. Local capacity constraints on housing, transportation, labor, skilled labor, etc.
Fiscal Effects: Property, sales, and other taxes expected from the project. Municipal service impacts including water, sewer, and public safety. Zoning and other local regulations and requirements.
Externalities: Valuation of human health or environmental effects. Changes in the local economy more generally through price or political changes.
The economic effects of a mining operation depend on the context of the local economy. Important factors include the location and sizes of nearby communities and commercial activity by sector (Pfeil 2005).
p.. 52 TABLE 5. MUNICIPALITIES NEAR THE PENOKEE RANGE
TABLE 6. BAD RIVER RESERVATION CENSUS DESIGNATED PLACES
p. 53 TABLE 7. PERSONAL INCOME BY SECTOR, ASHLAND COUNTY, 2001 AND 2011
The economic effects of a mining operation obviously depend on the specifics of the proposal. Any evaluation of a particular mining project therefore must include a detailed description of the proposal, which cannot be done until the mining operations plans are well developed.
These topics relate to three key issues: the mine’s expected gross revenue, property rights governing that revenue, and extent of commercial transactions with the local economy.
Roughly speaking, there are three types of linkage effects considered in an impact analysis, as follows:
1. Direct effects: Spending by the mining operation on materials, equipment, labor, and other other inputs.
2. Indirect effects: Spending by mine suppliers on inputs for their own businesses.
3. Induced effects: Spending by individuals for personal consumption.
p.55 FISCAL AND PUBLIC SERVICES ISSUES
Fiscal Impacts. Specific payment agreements negotiated between the mining operation and local governments (WDNR 1997a). Non-negotiated requirements on the mining operation, e.g., from zoning law. State taxes or fees related to the project (WDNR1997b; WDOR 2003. Property tax implications of the project, including current payments and reduced land value post extraction. Public Services. Current locations and capacities of public services including schools; hospital and emergency medical services; and police and fire protection. Additional demands anticipated on those services, given the anticipated population changes associated with the mining operation. Capacity of local roads and intersections relative to anticipated additional traffic associated with the mining operation. Changes in rail routes or traffic are anticipated and the effect of such traffic at crossings.
p. 56 EXTERNALITIES
A technological externality is an effect caused by physical means, as in the example of pollution generated by one person and experienced by another as reduced health. A pecuniary externality is an effect caused by changes in the prices of various other goods, as when purchases by a company raise the market price faced by all other buyers or a political action (e.g., a tax) affects prices.
To emphasize, the absence of money exchange does not imply that an effect is imaginary or unimportant. Instead it poses a measurement problem. That problem must be solved in two steps:
1. Assess the size of the effect. Assess how much pollution results, how widely dispersed it is and how many people are affected,
2. Estimate people’s valuation of the effect at that size.
p. 57 DATA SOURCES
U.S. Bureau of Labor Statistics, U.S. Bureau of Economic Analysis, U.S. Census Bureau’ U.S. Geological Survey, National Minerals Information Center
p. 58 5. WATER QUALITY MONITORING
Monitoring objectives for a given mine will depend on the specific conditions at that mine and will be determined during the permitting process as the ore body is investigated, the project facilities are planned, and baseline conditions are evaluated. Three objectives of monitoring that pertain to mining are: 1) determination of baseline conditions; 2) compliance with water quality standards; and 3) evaluation of changes in water quality.
Monitoring is most effective if sample locations used to determine baseline conditions are maintained throughout the life of the mine….
Because compliance monitoring may necessitate sample stations located above and below the mine and above and below discharge points (USEPA 2003a), knowledge of the location of mining facilities is important in planning sampling during the baseline sampling period. Information acquired during baseline monitoring will be used to develop a monitoring plan required as part of the National Pollution Discharge Elimination System (NPDES) permit process (USEPA 2003a).
5.2. MONITORING DESIGN
p.59 Mine monitoring plans often involve a combination of fixed, regular sampling dates supplemented by samples under high flow conditions (USEPA 2003a).
p.60 5.3. ANALYSIS
Just as monitoring objectives determine the design of a monitoring program, they also inform the analysis of data collected. Two common analytical objectives of mine monitoring are to compare water quality data with established environmental standards or with reference or baseline conditions.
5.4. GROUNDWATER MONITORING
Many of the issues involved in groundwater monitoring are similar to those already discussed for surface water monitoring, but there are some important differences. Determination of baseline conditions may be more difficult for groundwater because the nature of aquifers and groundwater flow patterns is often not known. Determining baseline conditions may require placement of many groundwater monitoring wells, not all of which may be needed once flow patterns are understood. Mines may affect groundwater levels both through mine construction that disrupts baseline flow and through pumping to remove water from the mine or for processing (USEPA 2003a). Groundwater wells are thus used both for sampling water quality and assessing groundwater level and flow rates.
It is usually necessary to establish a network of groundwater wells around the proposed mine site to determine baseline groundwater flow directions, rates, and water quality; some wells may be eliminated once flow patterns have been delineated (MOE 2012). If more than one aquifer may potentially be affected by mining activities, all of the aquifers should be sampled (USEPA 2003a). Standard groundwater well configurations have been proposed for waste disposal sites or known contaminated sites that may be useful for mines as well (Maqsood et al. 2004, Meyer et al. 1994). In general, a minimum of one upgradient well and 4 or 5 downgradient wells will be required for continued monitoring, but often more wells are appropriate (Maqsood et al. 2004)
Groundwater data collected during the baseline monitoring period are used in groundwater modeling for the mine site (USEPA 2003a). Groundwater models are usually necessary to develop a site water balance for managing runoff, discharges, and flow rates. Such models are also useful in designing better groundwater well monitoring networks (Maqsood 2004).
Sample frequency considerations for groundwater monitoring are similar to those for surface water monitoring and are affected by the variability of constituent concentrations and water levels.
p.61 Many discussions of analysis methods for groundwater monitoring are directed at hazardous waste sites, landfills, and other sites involving some form of waste disposal (USEPA 2009, Gibbons 1996, Davis and McNichols 1999). Such sites are regulated under the Resource Conservation and Recovery Act (RCRA), but solid wastes from mining were exempted from this act. Subsequent rules have modified this so that some mine wastes, such as waste solvents, follow the same regulations as other industrial wastes (USEPA 1994, USEPA 2003a).
p. 62 6. LABORATORY METHODS
Many of the environmental monitoring requirements, including what approved methods and limits may apply and what laboratory certification is necessary, can be found in the approved Wisconsin Natural Resources State Statutes and Administrative Codes. Table 8 lists many of these Chapters and their titles.
All mining waste or leachate from the wastes needs to meet the standards that apply to groundwater, surface water and wetlands (Wis Statute Chapter 295). The approved methods applicable to the Clean Water Act (CWA) are tabled in the current revision of the Federal Register, 40 CFR, part 136.
TABLE 8. WISCONSIN NATURAL RESOURCES STATE STATUTES AND ADMINISTRATIVE CODES RELEVANT TO TACONITE MINING
Both field and laboratory QA/QC are strongly recommended to support defensibility
6.1. TOXICITY ANALYSIS
WET, whole effluent toxicity testing is commonly performed on wastewater effluent, though in the case of taconite mining operations WET testing on stormwater discharges, from waste rock storage areas, for example, is appropriate. Both acute toxicity and chronic toxicity are assessed. Organisms such as water fleas, fat head minnows and algae are used to measure lethal and sub-lethal effects after exposure to different concentrations of the samples for specified lengths of times.
WET has the major advantage of being able to identify the potential for harm to downstream aquatic life without needing to identify the source of toxicity. WET testing may be particularly useful for routine monitoring of mining operations, because the composition of waste water may vary with ore composition, etc.
p. 64 pictures related to WET
p. 65 6.2. WASTE CHARACTERIZATION
ASTM D 5477-07 (or most recent approved version) is used to determine acid mine drainage (potential). Humidity cells are set up with samples of waste rock and flushed with water to create a laboratory-weathering experiment designed to enhance the mass release of acidity/alkalinity, metals, and other pertinent analytes from a sample of solid material.
While a standard test duration cannot be prescribed, humidity cell testing often requires several years to fully evaluate AMD potential of mine waste. A major concern historically, therefore, is that a mine waste will be categorized as “not acid producing” based on a relatively short period of dissolution testing. Samples have been tested that produced circumneutral drainage for periods of roughly 2, 5, 8, and 14 years then produced acidic drainage
Thus, waste rock characterization should not be viewed only as an initial testing procedure, but rather as an ongoing process that can serve as an “early warning” system for potential pollution problems throughout the life of a mine.
p. 66-97 7. ANNOTATED BIBLIOGRAPHY Over 200 sources are cited.
p.98 APPENDIX A: RESOURCES FOR METHODS OF SOCIAL INQUIRY
p. 100 APPENDIX B: EQUIVALENCE TESTS
p. 101- 103 APPENDIX C: OVERVIEW OF RELEVANT ANALYTICAL METH