2009 Montana Mining - Montana Mining Association

STILLWATER MINING COMPANY:
Committed to
environmental sustainability
Stillwater Mining Company’s (SMC) proactive environmental stance,
and its commitment to socially responsible management of its
operations, has lead to cutting edge innovation and operational partnering
which continues to be a model for the mining industry.
WATER TREATMENT AND OPERATIONAL INNOVATION
East Boulder Mine Water Treatment
The East Boulder Mine is located near the pristine waters of the
Boulder River, 32 miles southwest of Big Timber. The mine operates in
a glacier-carved mountain valley in the Beartooth Mountains, where
the East Boulder River forms the boundary of the permit area on the
east and north sides. Protection of the East Boulder River is the number
one priority within the environmental stewardship program at the
East Boulder Mine. For more than ten years, since mining began, the
East Boulder Mine has had no measurable impact on the surface
water quality within the East Boulder River.
Water management and water treatment at the East Boulder Mine
is defined by a tradition of innovation. In 2008, the East Boulder Mine
continued this tradition with additional improvements to the water
treatment systems. Systems already in place include the mine water
recycle system (80 to 90 percent water recycle/re-use), biological denitrification
(biological treatment of nitrate), biological nitrification
(treatment of ammonia), land application, and snowmaking. The biological
treatment systems are very efficient in nitrate and ammonia
removal. However, during the winter months colder water temperatures
tend to inhibit biological activity and result in a moderate loss of
treatment efficiency. During 2008, the East Boulder Mine installed a
heat exchanger/boiler system that maintains a minimum water temperature
of 12 degrees Celsius (53.6°F) throughout the biological treatment
cells. The resulting biological water treatment during the 08/09
22 Montana Mining 2009
Denitrification System at the East Boulder Mine.
Aerial of Stillwater Mine.
winter season (measured in percent nitrogen removed) has exceeded
99 percent, and has set a new standard for winter time removal efficiencies
at the mine site.
Looking forward into 2009, the East Boulder Mine is currently in the
process of designing a reverse osmosis (RO) water treatment system
that would function as a polishing cell or a backup system for the biological
treatment systems. The RO system would have the flexibility to
be used for mine water treatment or tailings water treatment in order
to maintain the proper water balance, both in the underground mine
and in the surface tailings storage facility. Improvements such as these
further demonstrate Stillwater Mining Company’s commitment to the
environment, and will help guarantee long-term protection of the surface
water resources within the East Boulder valley.
Stillwater Tertiary Treatment
for Septic Waste Water
The Stillwater Mine near Nye, Montana is located adjacent to the
Stillwater River and is approximately two miles north of the Absaroka-
Beartooth Wilderness Area. The Stillwater River flows through more
than twenty miles of wilderness before spilling out into the rolling
prairie and forested canyons along its 45 mile journey to the
Yellowstone River near the town of Columbus.
In order to protect surface water and groundwater resources within
the Stillwater Valley, SMC made a decision to replace the existing septic
and leach field system with a state-of-the-art AdvanTex Treatment
System for wastewater treatment. The AdvanTex Treatment System is
a multiple-pass, packed bed aerobic wastewater treatment technology
specifically designed and engineered for long-term processing of
wastewater. The treatment system utilizes textile media and naturallyoccurring
microorganisms to biologically treat the wastewater. The