Water Resources of Idaho
Water Resources of Idaho |
All NAWQA studies have several common characteristics designed to address the Nation's water-quality issues. Nationally consistent data collection and assessment methods make this possible and are critical for providing uniform and comparable information on water quality for the Nation. Ground-water, surface- water, and ecological studies were performed at various scales to understand the water-quality problems and to meet the needs of interested parties at the local, regional, and national levels. Partnerships and cooperative studies between local, State, and Federal agencies can help to meet specific needs. The following sections describe surface-water, ground-water, and ecological monitoring components of the Northern Rockies NAWQA. The design described in the following sections is similar to other NAWQA study areas nationwide.
Surface Water
Assessment of stream chemistry focused on an evaluation of how water quality of rivers and lakes varies in response to the effects of land use in different seasons and under different hydrologic conditions, and to estimate the flux of constituents on an annual basis. This was accomplished by monitoring a set of basic and intensive-fixed sites. The NROK had 10 basic-fixed and 2 intensive-fixed sites. Basic-fixed sites were sampled for nutrients, major ions, trace metals, and suspended sediment on a regular basis, approximately monthly, for the duration of the 2-year high-intensity phase of the study. The intensive-fixed sites were sampled for the same constituents as the basic fixed sites with the addition of pesticides and volatile organic compounds during selected time periods. The sites were selected to include a combination of specific land uses and hydrogeology that are considered to have potentially important effects on water-quality in the study area.
Figure of Surface Water Sites
Ground Water
The ground-water assessment in the NROK focused on water quality of two major basin-fill aquifers that are the principal sources of drinking water in their areas and include two aquifers designated as sole-source aquifers by the U.S. Environmental Protection Agency; the Spokane Valley/Rathdrum Prairie aquifer in northeastern Washington and northern Idaho, and the Missoula aquifer in southwestern Montana. These aquifers are highly susceptible to contamination. All wells were sampled for analysis of nutrients, major ions, trace metals, pesticides, VOC's, and radon. Selected wells were also sampled for stable and radioactive isotopes. A ground water/surface water interaction study also was conducted along the Spokane River in Idaho and Washington to examine the effects of recharge from the Spokane River on the hydrologic and chemical characteristics of the adjacent alluvial aquifer. A number of wells were installed in the alluvium adjacent to the river and sampled for selected constituents. Figure of Ground Water Sites
Ecology
Ecological assessments in the NROK focused on the effects of land use on stream ecology, especially as evidenced in fish tissue, fish communities, streambed sediment, and aquatic organisms. Fish tissue and streambed sediment samples were collected at all fixed sites and at additional stream sites for a basin-wide assessment of trace elements and organic compounds. A special study was conducted in the Spokane and St. Regis River Basins to evaluate the effects of mining on stream ecology. Another special study focused on contaminants in the Spokane River downstream of Lake Coeur d'Alene. Figure of Ecology Sites
U.S. Department of the Interior | U.S. Geological Survey
URL: id.water.usgs.gov/nrok/sampling.htm
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Page Last Modified: Wednesday, 22-Apr-2009 14:16:38 EDT
