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D. A. Nimick

Publications and source records attributed to D. A. Nimick.

21 records · Page 2Linked to original sources
USGS1994

Physical, chemical, and biological data for detailed study of the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge, west-central Montana, 1990-92, with selected data for 1987-89

Physical chemical, and biological data were collected in the lower Sun River area of west-central Montana during 1990-92 as part of a U.S. Department of the Interior detailed study of the extent, magnitude, sources, and potential biological impacts of contaminants associated with irrigation drainage. Physical and chemical data were collected from areas within and near the Sun River Irrigation Project and from wetland areas receiving irrigation drainage. Biological data were collected from areas in and near Freezout Lake Wildlife Management Area and Benton Lake National Wildlife Refuge. Additional biological data were collected previously during 1987-89 as part of a U.S. Fish and Wildlife Service program. This report presents data for selenium and other potentially toxic constituents in solid-phase, water, and biological media. Data consist of concentrations of major and trace elements in soil and drill cores; concen- trations of major ions, nutrients, and trace elements in ground water and surface water; and trace-element concentrations in bottom sediment and biological tissue. Hydrogeologic data for domestic and test wells and daily streamflow data for selected sites also are included.

Montana↗
USGS1993

Hydrology and water chemistry of shallow aquifers along the upper Clark Fork, western Montana

Shallow ground-water resources in western Montana have been developed primarily in Quaternary alluvium and Tertiary deposits, although bedrock supplies water to wells locally. Well-yield and trans- missivity values were largest (medians of 40 gallons per minute and 970 feet squared per day, respec- tively) in alluvium and smallest (medians of 15 gallons per minute and 130 feet squared per day, respectively) in bedrock. Chemical composition of ground water was dominated by calcium, magnesium, and bicarbonate derived from dissolution of carbonate minerals. Other water types may be the result of ion exchange (increased sodium) and mixing of geothermal water or leachate from mine wastes (increased sulfate). Although concen- trations of arsenic were relatively small (maximum of 20 micrograms per liter), they were somewhat larger in alluvium within 300 feet of the Clark Fork. Elevated concentrations of cadmium (maximum of 6 micrograms per liter) were measured in water from one well downgradient from tailings ponds. Although mining and smelting activities have resulted in widespread distribution of contami- nants in the Clark Fork valley, this study indicates that ground water contains elevated concentrations of trace elements only locally. Streamflow data indicate significant ground-water inflow to the Clark Fork in two reaches. Between Racetrack and Garrison, irrigation-return flow probably augments naturally occurring ground-water discharge. Between Jens and Cramer Creek, geo- thermal water from bedrock flows through alluvium to the river. In the Clark Fork, the maximum arsenic concentration was 8.1 micrograms per liter; copper and manganese concentrations were largest at Warm Springs (maximums of 14 and 350 micrograms per liter, respectively) and decreased downstream.

Water-Resources Investigations Report↗