No abstract

Hydrologic data collected in 1975~77 as part of a comprehensive waterresources investigation of Boulder County by the U.S. Geological Survey, in cooperation with the Boulder County Health Department and the Colorado Geological Survey, are presented in this report. The data, in tabular and graphic form, consist of water-quality analyses of selected constituents and geohydrologicsite, water-treatment, and sewage-treatment data for 609 wells and 48 springs; water-quality analyses for 102 of the wells and 9 of the springs; water quality analyses of streamflow from 34 sites; and specific conductance and watertemperature measurements of streamflow from 3 sites. State and local officials in Boulder County may find these data useful in planning for residential, commercial, and industrial development.

No abstract

Surface-water and ground-water data were compiled for the parts of the Colorado River and the White River basins in and adjacent to the Grand Hogback coal field.The data were evaluated to assess the quantity and quality of water resources available in the area for use in hydraulic coal mining.Based on discharge records, surface-water supplies of most streams should be adequate to meet the demands for hydraulic mining of 1 million tons of coal per year with a recycled water system. However, on some of the smaller streams in the area, some storage of water may be required for use during low-flow periods to meet minimum-flow requirements for downstream reaches. Other potential sources of water include Rifle Gap Reservoir, Harvey Gap Reservoir, and ground water from valley-fill deposits along major streams and rivers.The surface and ground water in the study area should be of adequate quality for use in hydraulic mining, with the possible exceptions of suspended-sediment concentrations that periodically may be as much as 18,800 milligrams per liter in streams in the Rifle Creek drainage, and dissolved-solids concentrations that are greater than 20,000 milligrams per liter in some aquifers.Data are insufficient to assess the potential impact of hydraulic coal mining on downstream water quali ty.