Historic mills and mill tailings as potential sources of contamination in and near the Humboldt River basin, northern Nevada
Bulletin
2210-D
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- More information: USGS Index Page (html)
- Larger Work: This publication is Chapter D of Geoenvironmental Investigations of the Humboldt River Basin, Northern Nevada
- NGMDB Index Page: National Geologic Map Database Index Page
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Abstract
Reconnaissance field studies of 40 mining districts in and near the Humboldt River basin have identified 83 mills and associated tailings impoundments and several other kinds of mineral-processing facilities (smelters, mercury retorts, heap-leach pads) related to historic mining. The majority of the mills and tailings sites are not recorded in the literature. All tailings impoundments show evidence of substantial amounts of erosion.
At least 11 tailings dams were breached by flood waters, carrying fluvial tailings 1 to 15 km down canyons and across alluvial fans. Most of the tailings sites are dry most of the year, but some are near streams. Tailings that are wet for part of the year do not appear to be reacting significantly with those waters because physical factors such as clay layers and hard-pan cement appear to limit permeability and release of metals to surface waters. The major impact of mill tailings on surface-
water quality may be brief flushes of runoff during storm events that carry acid and metals released from soluble mineral crusts. Small ephemeral ponds and puddles that tend to collect in trenches and low areas on tailings impoundments tend to be acidic and extremely enriched in metals, in part through cycles of evaporation. Ponded water that is rich in salts and metals could be acutely toxic to unsuspecting animals. Rare extreme storms have the potential to cause catastrophic failure of tailings
impoundments, carry away metals in stormwaters, and transport tailings as debris flows for 1 to 15 km. In most situations
these stormwaters and transported tailings could impact wildlife but probably would impact few or no people or domes-tic water wells. Because all identified historic tailings sites are several kilometers or more from the Humboldt River and major tributaries, tailings probably have no measurable impact on water quality in the main stem of the Humboldt River.
Suggested Citation
Nash, J.T., Stillings, L., 2003, Historic mills and mill tailings as potential sources of contamination in and near the Humboldt River basin, northern Nevada (Version 1.0): U.S. Geological Survey Bulletin 2210, vi, 36 p., https://doi.org/10.3133/b2210D.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Historic mills and mill tailings as potential sources of contamination in and near the Humboldt River basin, northern Nevada |
| Series title | Bulletin |
| Series number | 2210 |
| Chapter | D |
| DOI | 10.3133/b2210D |
| Edition | Version 1.0 |
| Year Published | 2003 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Description | vi, 36 p. |
| Larger Work Type | Report |
| Larger Work Subtype | USGS Numbered Series |
| Larger Work Title | Geoenvironmental investigations of the Humboldt River basin, northern Nevada |
| Time Range Start | 1995-01-01 |
| Time Range End | 2000-12-31 |
| Country | United States |
| State | Nevada |
| Other Geospatial | Humboldt River basin |
| Scale | 0 |