Search USGS⌕ Search

Geology topics

Walton H. Low

Publications and source records attributed to Walton H. Low.

6 recordsLinked to original sources
USGS1997

Activities of the National Water-Quality Assessment Program in the upper Snake River Basin, Idaho and western Wyoming, 1991-2001

In 1991, the U.S. Geological Survey (USGS) began a full-scale National Water-Quality Assessment (NAWQA) Program. The long-term goals of the NAWQA Program are to describe the status and trends in the water quality of a large part of the Nation's rivers and aquifers and to improve understanding of the primary natural and human factors that affect water-quality conditions. In meeting these goals, the program will produce water-quality, ecological, and geographic information that will be useful to policy makers and managers at the national, State, and local levels. A major component of the program is study-unit investigations, upon which national-level assessment activities are based. The program's 60 study-unit investigations are associated with principal river basins and aquifer systems throughout the Nation. Study units encompass areas from 1,200 to more than 65,000 mi2 (square miles) and incorporate about 60 to 70 percent of the Nation's water use and population served by public water supply. In 1991, the upper Snake River Basin was among the first 20 NAWQA study units selected for implementation. From 1991 to 1995, a high-intensity data-collection phase of the upper Snake River Basin study unit (fig. 1) was implemented and completed. Components of this phase are described in a report by Gilliom and others (1995). In 1997, a low-intensity phase of data collection began, and work continued on data analysis, report writing, and data documentation and archiving activities that began in 1996. Principal data-collection activities during the low-intensity phase will include monitoring of surface-water and ground-water quality, assessment of aquatic biological conditions, and continued compilation of environmental setting information.

Wyoming↗
USGS1987

Solute geochemistry of the Snake River plain regional aquifer system, Idaho and eastern Oregon

Three geochemical methods were used to determine chemical reactions that control solute concentrations in the Snake River Plain regional aquifer system: (1) Calculation of a regional solute balance within the aquifer and of mineralogy in the aquifer framework to identify solute reactions, (2) comparison of thermodynamic mineral saturation indices with plausible solute reactions, and (3) comparison of stable-isotope ratios of the ground water with those in the aquifer framework. The geothermal ground-water system underlying the main aquifer system was examined by calculating thermodynamic mineral saturation indices, stable-isotope ratios of geothermal water, geothermometry, and radiocarbon dating. Water budgets, hydrologic arguments, and isotopic analyses for the eastern Snake River Plain aquifer system demonstrate that most, if not all, water is of local meteoric and not juvenile or formation origin. Solute-balance, isotopic, mineralogic, and thermodynamic arguments suggest that about 20 percent of the solutes are derived from reactions with rocks forming the aquifer framework. Solute reactions indicate that calcite and silica are precipitated in the aquifer. Mineralogic evidence and thermodynamic arguments suggest that olivine, pyroxene, pyrite, and anhydrite are being dissolved and plagioclase is being weathered. Large amounts of sodium and chloride, relative to their concentration in the igneous rock, are being removed from the aquifer. Release of fluids from inclusions in the igneous rocks, and initial flushing of grain boundaries and pores of detrital marine sediments in interbeds are believed to be the source of the sodium chloride. Identification and quantification of reactions controlling solute concentrations in ground water in the eastern plain indicate that the aquifer is not a large mixing vessel that simply stores and transmits water and solutes but is undergoing diagenesis and is both a source and sink for solutes. Evaluation of solute concentrations and stable-isotope ratios of hydrogen, oxygen, carbon, and sulfur along ground-water flowpaths that transect irrigated areas suggests that irrigation water may have altered solute concentrations and isotope ratios in the eastern Snake River Plain aquifer system. The changes, however, have been small, owing to similarity of solute concentrations in applied irrigation water and in native ground water and rapid movement and large dispersivity of the aquifer. Reactions controlling solutes in the western Snake River basin are believed to be similar to those in the eastern basin but, because of different hydrologic conditions, a definitive analysis could not be made. The regional geothermal system that underlies the Snake River Plain contains total dissolved solids similar to those in the overlying Snake River Plain aquifer system but contains higher concentrations of sodium, bicarbonate, silica, fluoride, sulfate, chloride, arsenic, boron, and lithium, and lower concentrations of calcium, magnesium, and hydrogen. These solutes are believed to be derived from reactions similar to those in the Snake River Plain aquifer system, except that ion exchange may be a significant mechanism controlling solute concentrations in the geothermal system. Geothermometry calculations of selected ground-water samples from known geothermal areas throughout the basin suggest that the geothermal system is large in areal extent but has relatively low temperatures. Approximately half of the silica-quartz calculated water temperatures are greater than 90 degrees Celsius. Radiocarbon dating of geothermal water in the Salmon Falls and Bruneau-Grand View areas in the south-central part of the Snake River basin suggests that residence time of the geothermal water is about 17,700 years.

Idaho, Oregon↗
USGS1980

Water-quality conditions in the Milner reach, Snake River, south-central Idaho, October 18-21, 1977

During late October 1977, water discharge from Minidoka Dam into the Milner reach of the Snake River was less than 22 cubic meters per second, compared to normal flows for that time of year of about 42 cubic meters per second or more. To determine if impaired water-quality conditions existed, samples were collected at several sites above and below major point-source waste discharges near Burley, Idaho. Data collected for this study indicate some water-quality impairment within the study reach. At site 15 near Milner Dam, dissolved oxygen was below the 90-percent saturation standard prescribed by the Idaho water-quality standards. The total coliform and fecal coliform standards were exceeded at about one-third of the sites sampled on the main stem of the Snake River. Un-ionized ammonia concentration exceeded U.S. Environmental Protection Agency water-quality criteria at one site near Burley. Concentrations of trace metals, insecticides, and herbicides were all low; none exceeded existing criteria.

Idaho↗