Search USGS⌕ Search

Geology topics

Barney D. Lewis

Publications and source records attributed to Barney D. Lewis.

8 recordsLinked to original sources
USGS1985

Ground-water resources and potential hydrologic effects of surface coal mining in the northern Powder River basin, southeastern Montana

The shallow ground-water system in the northern Powder River Basin consists of Upper Cretaceous to Holocene aquifers overlying the Bearpaw Shale--namely, the Fox Hills Sandstone; Hell Creek, Fort Union, and Wasatch Formations; terrace deposits; and alluvium. Ground-water flow above the Bearpaw Shale can be divided into two general flow patterns. An upper flow pattern occurs in aquifers at depths of less than about 200 feet and occurs primarily as localized flow controlled by the surface topography. A lower flow pattern occurs in aquifers at depths from about 200 to 1,200 feet and exhibits a more regional flow, which is generally northward toward the Yellowstone River with significant flow toward the Powder and Tongue Rivers. The chemical quality of water in the shallow ground-water system in the study area varies widely, and most of the ground water does not meet standards for dissolved constituents in public drinking water established by the U.S. Environmental Protection Agency. Water from depths less than 200 feet generally is a sodium sulfate type having an average dissolved-solids concentration of 2,100 milligrams per liter. Sodium bicarbonate water having an average dissolved-solids concentration of 1,400 milligrams per liter is typical from aquifers in the shallow ground-water system at depths between 200 and 1,200 feet. Effects of surface coal mining on the water resources in the northern Powder River Basin are dependent on the stratigraphic location of the mine cut. Where the cut lies above the water-yielding zone, the effects will be minimal. Where the mine cut intersects a water-ielding zone, effects on water levels and flow patterns can be significant locally, but water levels and flow patterns will return to approximate premining conditions after mining ceases. Ground water in and near active and former mines may become more mineralized, owing to the placement of spoil material from the reducing zone in the unsaturated zone where the minerals are subject to oxidation. Regional effects probably will be small because of the limited areal extent of ground-water flow systems where mining is feasible. Results of digital models are presented to illustrate the effects of varying hydraulic properties on water-level changes resulting from mine dewatering. The model simulations were designed to depict maximum-drawdown situations. One simulation indicates that after 20 years of continuous dewatering of an infinite, homogeneous, isotropic aquifer that is 10 feet thick and has an initial potentiometric surface 10 feet above the top of the aquifer, water-level declines greater than 1 foot would generally be limited to within 7.5 miles of the center of the mine excavation; declines greater than 2 feet to within about 6 miles; declines greater than 5 feet to within about 3.7 miles; declines greater than 10 feet to within about 1.7 miles; and declines greater than 15 feet to within 1.2 miles.

Water Supply Paper↗
USGS1982

Evaluation of a predictive ground-water solute-transport model at the Idaho National Engineering Laboratory, Idaho

Aqueous chemical and radioactive wastes discharged to shallow ponds and to shallow or deep wells on the Idaho National Engineering Laboratory (INEL) since 1952 have affected the quality of the ground water in the underlying Snake River Plain aquifer. The aqueous wastes have created large and laterally dispersed concentration plumes within the aquifer. The waste plumes with the largest areal distribution are those of chloride, tritium, and with high specific conductance values. The data from eight wells drilled near the southern INEL boundary during the summer of 1980 were used to evaluate the accuracy of a predictive modeling study completed in 1973, and to simulate 1980 positions of chloride and tritium plumes. Data interpretation from the drilling program indicates that the hydrogeologic characteristics of the subsurface rocks have marked effects on the regional ground-water flow regimen and, therefore, the movement of aqueous wastes. As expected, the waste plumes projected by the computer model for 1980, extended somewhat further downgradient than indicated by well data due to conservative worst-case assumptions in the model input and inaccurate approximations of subsequent waste discharge and aquifer recharge conditions. (USGS)

Idaho↗
USGS1981

Hydrologic conditions at the Idaho National Engineering Laboratory, Idaho, emphasis: 1974-1978

The Idaho National Engineering Laboratory (INEL) site covers about 890 square miles of the eastern Snake River Plain and overlies the Snake River Plain aquifer. Low concentrations of aqueous chemical and radio-active wastes have been discharged to shallow ponds and to shallow or deep wells on the site since 1952. The regional water table ranges from about 200 feet to more than 1,000 feet below land surface within the INEL boundaries. The gradient of the water table averages about 4 feet per mile to the south-southwest. During the latest period of record, 1974 through 1978, the position of the water table has shown a net decline that ranges from 0.2 foot near the northern boundary of the INEL to more than 10 feet in the central and southern parts of the site. Recharge from surface water has been minimal or non-existent during the latter part of this period. A large body of perched ground water has formed in the basalt underlying the waste disposal ponds in the Test Reactor Area. This perched zone contains tritium, chromium-51, cobalt-60, strontium-90, and several nonradioactive ions. Tritium is the only mappable waste constituent in that portion of the Snake River Plain aquifer directly underlying this perched zone. Low concentrations of chemical and low-level radioactive wastes enter directly into the Snake River Plain aquifer through the Idaho Chemical Processing Plant (ICPP) disposal well. From 1974 through 1978, this 600-foot well was used to discharge a total of 1,861 million gallons of waste water which contained 1,697 curies of radioactivity, ninety-five percent of which was tritium. Tritium has been discharged to the well since 1953 and has formed the largest waste plume, about 28 square miles in area, in the regional aquifer, and minute concentrations have migrated downgradient a horizontal distance of 7.5 miles. Other waste plumes south of the ICPP contain sodium, chloride, nitrate, and the resultant specific conductance. These plumes have similar configurations, flow southward, and the contaminants are in general laterally dispersed in that portion of the aquifer underlying the INEL. Other waste plumes, containing strontium-90 and iodine-129, cover small areas near their points of discharge because strontium-90 is sorbed from solution as it moves through the aquifer and iodine-129 is discharged in very low quantities. Cesium-137 is also discharged through the well but it is strongly sorbed from solution and has never been detected in a sample of ground water at the INEL. Radionuclide plume size and concentrations therein are controlled by aquifer flow conditions, the quantity discharged, radioactive decay, sorption, dilution by dispersion, and perhaps other chemical reactions. Distributions of non-radoactive chemical wastes are subject to the same processes except for radioactive decay.

Idaho↗
USGS1979

Saline-seep development in the Hailstone Basin, northern Stillwater County, Montana

As a result of an increase in saline seep occurrence in Montana, a study was begun in 1974 to determine the hydrogeology of saline seeps in the Hailstone basin. The aquifer is composed of colluvium of Holocene age. The impermeable Cretaceous Niobrara Formation underlies the saturated zone basinwide. The ground-water system is shallow, unconfined, and locally recharged. Ground-water levels and size of the saline seeps respond rapidly to precipitation in the basin. The appearance and growth of saline seeps are related to precipitation patterns; the agricultural practice of summer follow; topography; the presence of a shallow, unconfined, and locally recharged ground-water system; and a soluble salt source. Continuous cropping could reduce the amount of water percolating beneath local recharge areas, and thus minimize the water available for seep formation and growth. The lateral variation in chemical quality of water from wells suggests a shallow flow system. The field specific conductance of 29 ground-water samples collected in 1976 ranged from 2,160 to 14,000 micromhos per centimeter and averaged 6,660 micromhos per centimeter. Water from saline seeps in the study area contains principally sodium, magnesium, calcium, and sulfate. Nitrate is present in the ground water in concentrations of as much as 855 milligrams per liter. The high nitrate concentrations are interpreted to originate primarily from oxidation of organic material once native sod is broken by cultivation. (USGS).

Montana↗
USGS1978

Geology and water-yielding characteristics of rocks of the northern Powder River basin, southeastern Montana

Numerous and widespread subbituminous and lignite coal deposits occur in the Powder River Basin in southeastern Montana, principally within the Fort Union Formation. Many of the coal beds are less than 250 feet (76.2 m) below land surface and are, therefore, mineable by surface methods. Individual cola beds are commonly 20-30 feet (6.1-9.1 m) thick, but may be as much as 80 feet (24 m). These factors, coupled with the low-sulfur content of the coal, make it attractive as a major energy resource.

Nevada↗