Geology topics
Wayne A. Wood
Publications and source records attributed to Wayne A. Wood.
Appraisal of ground-water quality near wastewater-treatment facilities, Glacier National Park, Montana
Water-level and water-quality data were collected from monitoring wells at wastewater-treatment facilities in Glacier National Park. Five additional shallow observation wells were installed at the Glacier Park Headquarters facility to monitor water quality in the shallow ground-water system. Water-level, water-quality, and geologic information indicate that some of the initial monitoring wells are not ideally located to sample ground water most likely to be affected by waste disposal at the sites. Small differences in chemical characteristics between samples from monitor wells indicate that effluent may be affecting ground-water quality but that impacts are not significant. Future monitoring of ground-water quality could be limited to selected wells most likely to be impacted by percolating effluent. Laboratory analyses for common ions could detect future impacts.
Changes in quality of ground water in the Lincoln area, Montana, 1974-79
Water samples from representative shallow wells in the vicinity of Lincoln, Montana, were collected during March and June 1979 for analysis to evaluate changes in quality since 1974-75 and possible contamination by domestic or agricultural waste. All samples were suitable for drinking water with respect to the constituents tested. Tests for fecal coliform bacteria were negative. The concentrations of dissolved solids, composed mainly of calcium, magnesium, bicarbonate, and sulfate, were less than 300 milligrams per liter. Concentrations of sodium, potassium, and chloride were 3.5 milligrams per liter or less. From March to June, the maximum concentration of nitrite plus nitrate as nitrogen decreased from 0.57 to 0.29 milligram per liter and the mean concentrations decreased from 0.16 to 0.11 milligram per liter, probably as a result of dilution of ground water by snowmelt. The concentrations in samples from the same wells generally were less during 1979 than during 1974-75. Isolation of sewage effluent in shallow zones by hardpan, consumption of nutrients by abundant phreatophytes, filtration of bacteria by the soil or aquifer, and dilution by underflow and recharge evidently combine to maintain the quality of the well waters within acceptable limits.
Supplemental data from the Ennis and other thermal-springs areas, Southwestern Montana, 1978-80
Hydrogeologic data were collected principally during 1978-80 in eight hot-spring areas, in the Marysville geothermal test well, in the Butte Mine and in the Bitterroot and Missoula River valleys to provide a basis for evaluating the geothermal potential of the areas. Measurements are tabulated for subsurface temperatures, water levels, rates of flow, and the chemical composition of water and gas in wells and test holes. Most of the data are for the area near Ennis Hot Springs.
Geothermal gradients in the Missoula and Bitterroot Valleys, west-central Montana
Temperature-depth profiles of six cased test holes in the Missoula and Bitterroot Valleys, west-central Montana, consist of linear segments, the intersections of which commonly correspond with lithologic boundaries. Geothermal gradients commonly decreased with depth, probably as a result of compaction and higher quartz content of the deeper sedimentary deposits. There is no evidence for hydrothermal discharge. A maximum temperature of 31.7 degrees Celsius was measured at a depth of 869 meters. Estimated temperatures at a depth of 1 kilometer at the drill sites ranged from about 34 to 63 degrees Celsius. Temperatures exceeding 90 degrees Celsius probably would not occur at depths less than 1,500 meters. Values of thermal conductivity needed to maintain an assumed regional heat flow of about 2.1 heat flow units along the measured geothermal gradients generally exceeded published values for the rock and soil penetrated by the wells. Laboratory determinations of the thermal conductivity of cores and cuttings would be useful to refine the estimates and to test the conclusion that the measured temperatures are not hotter than normal. (USGS)