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Investigation of the chemical composition and distribution of mining wastes in Killarney Lake, Coeur d'Alene Area, Northern Idaho Item Info

Killarney Lake, a lateral lake of the Coeur d'Alene River in northern Idaho, received mining and milling wastes from the Coeur d'Alene mining district for nearly 100 years. Mining and milling wastes were transported by the river during flood events until 1968 when tailings ponds were built. Lake bed sediments in Killarney Lake were sampled at three separate localities using a piston core sampler operated from a raft. The cores collected 3.6 m and 3.5 m of lake bottom sediments from the north and south ends of the lake, respectively, and 6.4 m of sediments from the center of the lake. Lake bed sediments were also sampled to a depth of 59 em using a freezer box sampler. A control core and freezer box section were extracted from Bells Lake in the nearby St. Joe River drainage, an area free of commercial mining practices. Identification of the Mazama ash, which was collected at 6.1 m below lake bottom in Killarney Lake and 3.8 m below lake bottom in Bells Lake, by microprobe analysis enabled the chronology of cores from both lakes to be constrained. The lake bottom sediments were sampled to. evaluate heavy metal concentrations downstream of the mining district. Sediments were analyzed by atomic absorption spectrometry for As, Ag, Cd, Cu, Fe, Mn, Ni, Pb, and Zn. Sediments from Bells Lake showed similar chemistry to the pre-mining sediments in Killarney Lake, suggesting that Bells Lake was an adequate control. High concentrations of heavy metals are present in the top 59 em of the Killarney Lake bed at the center and deepest portion of the lake. Up to 17.5 em of metallic silt were collected at the north and south ends of the lake. The highest observed metal concentrations in the sediment were 376 ppm As, 37 ppm Ag, 475 ppm Cu, 146 ppm Cd, 111,000 ppm Fe, 13,440 ppm Mn, 71 ppm Ni, 37,400 ppm Pb, and 32,850 ppm Zn. In this uppermost layer, concentrations of metals are 1 to 3 orders of magnitude greater than in deeper Killarney Lake sediments or in Bells Lake. A sharp, defined contact was observed between the natural organic silt and the introduced metallic silt. Organic silt was also observed overlying the metallic silt in the freezer box sample. Sediments with heavy metal concentrations above that of background were found to occur a maximum of 22.5 em below the lower metallic silt and organic silt contact.

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Title:
Investigation of the chemical composition and distribution of mining wastes in Killarney Lake, Coeur d'Alene Area, Northern Idaho
Authors:
Bender, Scott F.
Date Created (ISO Standard):
1991-10
Description:
Killarney Lake, a lateral lake of the Coeur d'Alene River in northern Idaho, received mining and milling wastes from the Coeur d'Alene mining district for nearly 100 years. Mining and milling wastes were transported by the river during flood events until 1968 when tailings ponds were built. Lake bed sediments in Killarney Lake were sampled at three separate localities using a piston core sampler operated from a raft. The cores collected 3.6 m and 3.5 m of lake bottom sediments from the north and south ends of the lake, respectively, and 6.4 m of sediments from the center of the lake. Lake bed sediments were also sampled to a depth of 59 em using a freezer box sampler. A control core and freezer box section were extracted from Bells Lake in the nearby St. Joe River drainage, an area free of commercial mining practices. Identification of the Mazama ash, which was collected at 6.1 m below lake bottom in Killarney Lake and 3.8 m below lake bottom in Bells Lake, by microprobe analysis enabled the chronology of cores from both lakes to be constrained. The lake bottom sediments were sampled to. evaluate heavy metal concentrations downstream of the mining district. Sediments were analyzed by atomic absorption spectrometry for As, Ag, Cd, Cu, Fe, Mn, Ni, Pb, and Zn. Sediments from Bells Lake showed similar chemistry to the pre-mining sediments in Killarney Lake, suggesting that Bells Lake was an adequate control. High concentrations of heavy metals are present in the top 59 em of the Killarney Lake bed at the center and deepest portion of the lake. Up to 17.5 em of metallic silt were collected at the north and south ends of the lake. The highest observed metal concentrations in the sediment were 376 ppm As, 37 ppm Ag, 475 ppm Cu, 146 ppm Cd, 111,000 ppm Fe, 13,440 ppm Mn, 71 ppm Ni, 37,400 ppm Pb, and 32,850 ppm Zn. In this uppermost layer, concentrations of metals are 1 to 3 orders of magnitude greater than in deeper Killarney Lake sediments or in Bells Lake. A sharp, defined contact was observed between the natural organic silt and the introduced metallic silt. Organic silt was also observed overlying the metallic silt in the freezer box sample. Sediments with heavy metal concentrations above that of background were found to occur a maximum of 22.5 em below the lower metallic silt and organic silt contact.
Subjects:
mine wastes sediment heavy metals
Location:
Killarney Lake; Coeur d'Alene River
Latitude:
47.52
Longitude:
-116.56
Collection:
Coeur d'Alene Basin
IWRRI number:
199101
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
Publisher:
University of Idaho
Contributing Institution:
University of Idaho
Type:
Text
Format:
application/pdf
Cataloger:
wbv
Date Digitized:
2012

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Preferred Citation:
"Investigation of the chemical composition and distribution of mining wastes in Killarney Lake, Coeur d'Alene Area, Northern Idaho", Idaho Waters Digital Library, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/iwdl/items/iwdl-cda_bender_1991.html
Rights
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
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