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Steven E. Slagle

Publications and source records attributed to Steven E. Slagle.

9 recordsLinked to original sources
USGS1995

Geohydrologic conditions and land use in the Gallatin Valley, southwestern Montana, 1992-93

The Gallatin Valley is part of an intermontane basin in southwestern Montana with an area of about 540 mi2. The valley is drained by the Gallatin River and its tributaries. After formation of the Three Forks structural basin, the Gallatin Valley was filled with as much as 6,000 feet of Tertiary and Quaternary sediments. Depth to water in the study area generally ranges from about 3 feet to about 460 feet below land surface. The median specific capacity of 26 wells completed in alluvium was 4.6 gallons per minute per foot. The median specific capacity of 21 wells completed in Quaternary and Tertiary alluvial-fan deposits in the southern and eastern part of the area was 1.6 gallons per minute per foot. The median specific capacity of 16 wells completed in Tertiary sediments was 0.78 gallon per minute per foot. Water from 38 wells sampled for water-quality analyses generally was a calcium bicarbonate type containing dissolved-solids concentrations ranging from 113 to 551 milligrams per liter. Radon-222 concentrations in water from 16 samples wells ranged from 170 to 1,565 picocuries per liter. Water samples collected from 6 wells were analyzed for a total of 54 pesticides and pesticide- degradation products. No pesticides or related analytes were detected in any of the samples. Agriculture is the primary land use in the Gallatin Valley; however, population growth has resulted in the establishment of numerous rural subdivisions. Water-level measurements made during this study coupled with long-term water-level trends do not indicate any significant water-level changes resulting from increased ground-water withdrawals. The occurrence of larger nitrate concentrations (maximum of 4.5 milligrams per liter) in ground water in more densely developed areas indicates a possible influence of subdivision development on ground-water quality.

Montana↗
USGS1994

Records of water levels in monitoring wells in the Gallatin Valley, southwestern Montana, 1947-93

Water-level data were collected in the Gallatin Valley to provide a basis for evaluation of the configuration of the ground-water surface and water-level change. Water-level records collected during a 2-year study of the area and historical water-level data for 121 wells in the Gallatin Valley are summarized in the report. Well-depth and primary-aquifer data are included. The locations of the wells are shown on a map at a scale of 1:275,500.

Open-File Report↗
USGS1980

Geohydrology of southwestern Kansas

Southwestern Kansas is one of the principal areas of ground-water development for irrigation in the State, and many reports are available concerning ground-water conditions in the area. The purposes of this investigation were to consolidate and update data, to determine the extent and effects of irrigation development on the ground-water resource, to determine the chemical quality of the ground water in relation to irrigation use, to describe the general operation of the hydrologic system, and to identify problem areas where intensive quantitative studies will be needed by State and local agencies for planning and management of the resource. This study began in 1972 as part of a cooperative program of ground-water investigations between the Kansas Geological Survey and the U.S. Geological Survey. Support in this study was provided by the Division of Water Resources of the Kansas State Board of Agriculture and the Division of Environment of the Kansas Department of Health and Environment.

Kansas↗
USGS1975

Ground-water resources of Greeley and Wichita counties, Western Kansas

Unconsolidated deposits of sand, silt, clay, and gravel compose the principal aquifer in Greeley and Wichita Counties. The deposits are as much as 300 feet (91 m) 2/ thick, of which as much as 145 feet (44 m) is saturated. In 1972, there were about 1,040 large-capacity wells--yielding 100 gallons per minute (6.3 1/s) or more--in the counties, mostly for irrigation supplies. The wells yield as much as 2,000 gallons per minute (130 1/s). Withdrawals of ground water average about 220,000 acre-feet (270 hm 3 ) annually. Water levels have declined in parts of the area where large-capacity wells are concentrated, resulting in as much as 60-percent reduction in saturated thickness. Water-level declines during 1948-72 ranged from less than 10 to about 55 feet (3-17 m). The largest decline, about 55 feet (17 m), has occurred near Leoti, in central Wichita County. As of January 1972, about 5 million acre-feet (6,000 hm) of ground water were in storage in Greeley and Wichita Counties; however, only about 70 percent of this amount is considered to be available for pumping. The water from the unconsolidated aquifer is a mixed chemical type in which calcium, sodium, and bicarbonate are the principal constituents. Generally, the water is suitable for all common domestic, stock, and irrigation uses. Price increases for grain in 1973 and absence of acreage controls probably will encourage additional development of ground water for irrigation. Increased withdrawals will, however, accelerate the rate of water-level decline and reduction in ground-water storage. Increased water-level declines will be accompanied in most of the area by noticeable decreases in well yields. Any additional increase in the rate of withdrawal in areas where saturated thickness has declined about 40 percent or more may significantly shorten the economic life of the aquifer. Additional development in these areas should be considered with regard to increasing pumping costs and decreasing well yields. Development of the ground-water resource could be managed in several ways. The formation of Kansas Ground-Water Management District Number 1 provides a means by which local water users can decide on various management alternatives that would affect the future of their irrigation supply.

Kansas↗