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Proposed Wisconsin Exxon Mine
Alice McCombs (EarthWINS@AOL.COM)
Mon, 24 Jul 1995 10:55:34 -0400
METALLIC SULFIDE MINING IN WISCONSIN--WHAT YOU SHOULD KNOW
Northern Wisconsin is underlain by ancient volcanic rock known as the
Greenstone Belt. Research by Wisconsin Resources Protection Council has found
that 18 sites are currently under investigation or are known to have ore
containing zinc, copper, lead, gold and silver, as well as numerous other
minerals and elements. These minerals are found as massive sulfides, or rocks
formed by minerals in combination with sulfur. Unlike the relatively inert
taconite and iron ores mined throughout Minnesota, Wisconsin, and Michigan,
metallic sulfide ores in this state can and do produce sulfuric acid and Acid
Mine Drainage (AMD). Sulfuric acid is formed when sulfide rock is exposed to
air and water (oxidation) during and after mining activity. AMD is the toxic
brew of both sulfuric acid and the heavy metals and toxic elements leached
from the rock due to the interaction with the acid.
According to the U.S. Bureau of Mines, over 10,000 miles of rivers and
streams have already been contamimated by mining operations. The
Environmental Protection Agency (EPA) currently lists at least 48 Superfund
clean-up sites directly caused by mining; more than half are either active
operations or are recently abandoned sites, reflecting current technology and
operating practices. One project alone, the Summitville mine in Colorado,
sterilized 17 miles of the Alamosa River and was abandoned by its operators
in 1992. Total tax dollars needed to clean up this disaster are now projected
to be $120 million. Mining industry claims that only "old" mines pollute are
simply not true.
Groundwater contamination from AMD has occurred in Wisconsin. The
Shullsberg mine in the southwestern lead-zinc district closed in 1979 and
left behind serious increases in sulfates, zinc, iron and other metals and
elements in groundwater. Vomiting, diarrhea, and greater health risks among
well users and serious economic losses for dairy operations forced the State
of Wisconsin to investigate the contamination and ultimately help pay for new
wells in a deeper aquifer (Evans and Cieslik,1985). A 1995 investigation by
WI DNR suggests limestone and dolomite rock in this part of the state limited
the AMD of abandoned mines and averted even more contamination. Acid
generation potential is much greater in northern Wisconsin since naturally
buffering minerals are largely absent.
Most of Wisconsin's potential mine sites are located near headwaters of
rivers and within wetlands or forests. Mining in Northern Wisconsin
threatens both surface and groundwater quality, wildlife, recreation and
tourism. The "boom and bust" cycle of mining development is the source of
numerous ghost towns and depressed economies throughout the United States.
Volatile metal prices on the world market make it unlikely that a mine will
stay in operation even until the resource is exhausted. The extractive
industries are also well known for ignoring the treaty rights and sovereignty
of Native Americans and other indigenous peoples.
Current Concerns:
Exxon Corporation, fined $5 billion for negligence in the 1987 Exxon
Valdez Alaskan oil spill, has returned to revive the mining project it
abandoned in 1986. Exxon has formed Crandon Mining Company (CMC) with
multinational mining company Rio Algom (also notorious, for dumping
radioactive waste into Ontario's Serpent River) CMC is attempting to develop
an underground zinc and copper mine near the Mole Lake Sokaogon Chippewa
Reservation in Forest County. The proposed mine is situated within the
headwaters area of the pristine and trout-rich Wolf River, a designated
National Wild and Scenic Riverway and a state Outstanding Resource Water.
According to CMC's Mine Permit Application documents filed with the State
early this summer, the proposed project (mine shafts, milling plant,
administrative buildings, roads, pipelines and waste rock tailings ponds)
would cover more than 600 acres. At least 30 acres of on-site wetlands would
be bulldozed. 345 acres of forest and wetlands at the site would be
permanently covered by tailings ponds that must keep the AMD-producing waste
rock and the toxic waste created by the milling operation out of the
groundwater forever. One example of state law that grants special favor to
the mining industry, also implicitly acknowledges that tailings ponds will
eventually leak. When Exxon and other miners helped draft new state mining
law in the 1980's, they negotiated a loophole that would allow pollution.
Only after groundwater pollution is detected 1,200 feet away from the edges
of tailings ponds, are mining interests required to begin clean-up.
"Once started (AMD) is self-perpetuating and very difficult to stop...it
persists for decades or even centuries..."California Mining Waste Study, 1988
More Impacts to Water:
Wisconsin DNR estimated in 1986 that groundwater flowing into the mine
itself during operations could average 2-3,000 gallons per minute or more
than 2.8 million gallons every day over a projected 28 years of operations.
Roughly the same amount daily would be treated and discharged to the
Wisconsin River via a 37 mile-long underground pipeline. Impacts to the Wolf
River watershed caused by the diversion of this water include significant
drawdown of not only the aquifer, but of nearby streams and lakes. Wisconsin
DNR has confirmed that wastewater discharged into the Wisconsin River will
cost Exxon less money to treat and allow more contaminants into state waters
than a prior option that placed the effluent directly in the more protected
Wolf River watershed. A partial list of contaminant metals and elements that
would be discharged include: arsenic, lead, zinc, copper, sulfates, mercury,
cadmium, and selenium. Comprehensive impact analysis is difficult as
treatment plant plans and results of computer model predictions of
groundwater drawdown and inflow to the mine have yet to be released by Exxon.
More Environmental Impacts:
Construction Phase:
-Construction related dust, noise, traffic, and air pollution.
-Increased stream sedimentation due to erosion.
-Wetland drainage and destruction; elimination of habitat.
Mining Phase:
-Noise from blasting, ore transport by rail & truck, milling (rock grinding),
and tailings deposition-all affecting local populations and wildlife habitat.
To date, 7 threatened or endangered species have been found at or near the
proposed site: the Goblin Fern, Bald Eagle, Osprey, Dwarf Bilberry,
Red-shouldered Hawk, Northern Blue Butterfly and Mountain Cranberry
(previously thought extinct in Wisconsin).
-Air Pollution from sulfur-laden fugitive dust from milling and tailings
deposition.
-Sulfuric Acid produced from exposed ore and waste rock stored above ground
prior to milling and from tailings after milling removes the desired metals.
Acid production and leaching of heavy metals and elements from waste rock
backfilled into the mine itself.
-Transportation, storage and use of chemical reagents-such as sodium cyanide,
xanthates, sulfuric acid and others-in huge amounts for separating
(concentrating) metals from ore. Leftover waste sludge from this process is
to be stored forever with the tailings. Note-Only 3 years ago, the largest
ever US civilian evacuation due to a chemical spill took place in Superior,
WI., when railroad tanker cars holding benzene derailed. The death toll on
fish and wildlife, and long-term impacts to the environment are still being
studied.
Reclamation:
-as noted above, long-term threats to surface and groundwater are very real.
Facts About Proposed Exxon Mine
Should mining permits be granted to Exxon and barring any market, labor or
environmental events causing shutdowns or early closure, their proposal
includes:
Construction of facilities, roads, railroad: 3 years
Operational life of mine: 28 years
Daily ore production: 5,500 tons (2 million per year)
Project ore total production: 55 million tons
Waste rock stored above ground: approx. 25 million tons
Waste rock backfilled into mine: approx. 25 million tons
Reclamation: 4 years
The mining industry and state DNR were challenged to find examples of
successful reclamation and have failed. There has never been a successfully
reclaimed metallic sulfide mine anywhere in this country. Why permit them in
Wisconsin?
Report by Mining Impact Coalition of Wi. Inc. (608) 255-6629
References available on request.
Distributed by:
WATERSHED INFORMATION & NEWS SERVICE (WINS)
Committed to Serving All Our Relations in the Great Lakes and Mississippi
Watersheds
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