| Acid mine drainage is the most common means of releasing hazardous waste. AMD is caused when
sulfur in waste rock, tailings or ore mixes with water and oxygen to form sulfuric acid. The high
acidity dissolves metals such as aluminum into the water. Newmont's Rain Mine south of Carlin is a
good example of a mine that is leaking acid into downstream waters. | |
| Pit lakes form when the dewatering wells stop pumping. If the surrounding rock contains sulfur,
the water that drains into the pit may be acidic. The Berkeley Pit, pictured above, contains hazardous
concentrations of many heavy metals. |
| Heap closure, the process of cleaning up a cyanide heap, can also pollute
the groundwater. Too often, the mining industry, with state concurrence,
is allowed to discharge the seepage from their cyanide heaps into the ground. At the
Candelaria Mine and the Wind Mountain Mine, this seepage has contaminants at concentrations
that exceed hazardous waste standards. |
| Many mines spill hazardous waste at their sites.
Click here for a report (4.7 megs) on hazardous waste spills from 1992 through 2000 in Nevada.
It shows that Newmont is by far the leader when it comes to spills. |
| The most polluted mines qualify for clean-up under the Superfund program. This program, codified as
the Comprehenxive Environmental Response, Compensation, and Liability Act (CERCLA), is designed to prevent
and remediate the worst discharges of hazardous waste. Short term removals are emergency actions at
sites which may soon be polluting the environment. Long-term remedial actions at sites with significant
hazardous pollution at completed at sites on the National Priorities List (NPL). |
| Click here for a map and list of all
NPL sites in the United States. |
| There is only one site in Nevada. The Carson River from Dayton to Lake Lahontan has mercury laden
tailings on its shore. This resulted from historic mining in on the Comstock near Virginia City, NV.
However, there are at least two sites that clearly qualify for listing on the NPL. One of the
most polluted sites is the Yerington Mine. Click here
for a tour of this site and a
letter explaining the reasons NPL status is the only way this site will ever be cleaned up
and the contaminants will cease threatening the nearby Yerington Paiute Reservation or the City of
Yerington. Another site is the Rio Tinto mine near the Duck Valley Reservation north of Elko, NV. |
