Geology topics
Publications and source records attributed to James W. Warner.
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Diisopropylmethylphosphonate (DIMP) is an organic compound produced as a byproduct of the manufacture and detoxification of GB nerve gas. Ground-water contamination by DIMP from the disposal of wastes into unlined surface ponds at the Rocky Mountain Arsenal occurred from 1952 to 1956. A digital-transport model was used to determine the effects on ground-water movement and on DIMP concentrations in the ground water of a bentonite barrier in the aquifer near the northern boundary of the arsenal. The transport model is based on an iterative-alternating- direction-implicit mathematical solution of the ground-water-flow equation coupled with a method-of-characteristics solution of the solute-transport equation. The model assumes conservative (nonreactive) transient transport of DIMP and steady-state ground-water flow. In the model simulations, a bentonite barrier was assumed that was impermeable and penetrated the entire saturated thickness of the aquifer. Ground water intercepted by the barrier was assumed to be pumped by wells located south (upgra-dient) of the barrier, to be treated to remove DIMP, and to be recharged by pits or wells to the aquifer north (downgradient) of the barrier. The amount of DIMP transported across the northern boundary of the arsenal was substantially reduced by a ground-water-barrier system of this type. For a 1,500-foot-long bentonite barrier located along the northern boundary of the arsenal near D Street, about 50 percent of the DIMP that would otherwise cross the boundary would be intercepted by the barrier. This barrier configuration and location were proposed by the U.S. Army. Of the ground water with DIMP concentrations greater than 500 micro- grams per liter, the safe DIMP-concentration level determined by the U.S. Army, about 72 percent would be intercepted by the barrier system. The amount of DIMP underflow intercepted may be increased to 65 percent by doubling the pumpage, or to 73 percent by doubling the length of the barrier.
A hydrologic reconnaissance of a 74-kilometer reach of the Yampa River in Dinosaur National Monument was made during low flow in mid-August 1976. Stream discharge, which was measured along this reach every 16 to 24 kilometers, ranged from 9.4 to 10.6 cubic meters per second. Variations in streamflow were explained, in part, by underflow, loss to ground water, and evaporation. Specific conductance was measured about every 2 kilometers and indicated a downstream increase on the order of 11 to 12 percent for the reach. Except for mercury, bottom-sediment trace-element concentrations in the study reach were less than maximum concentrations determined during August-September 1976 for bottom sediments at unperturbed sites upstream in the Yampa River basin. At one of five sampling sites, the mercury concentration in bottom sediments exceeded the maximum measured upstream level.
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The San Bernardino Valley Municipal Water District began receiving its initial entitlement of 46,000 acre-feet (5.7 x 107 cubic metres) per year of imported northern California water in December 1972. By 1990, the district will be receiving 102,000 acre-feet (1.3 x 108 cubic metres) per year. Plans are to distribute this imported water for artificial recharge to the local ground-water system. The upper Santa Ana River area is well suited for artificial recharge because it is largely underlain by permeable river-channel deposits. Some sandy clay, silt, and cemented sand and gravel layers occur that may locally retard downward percolation of recharge water. However, test drilling indicates none of these is extensive enough to impede recharge in the spreading grounds. Analyses of ground-water movement during current water-spreading operations, test-drilling data, and application of Baumann's (1965) equation for calculating the theoretical size of the recharge mound indicate that (1) barriers to ground-water movement are not evident in the river-channel deposits, (2) depth to the basement complex is less in the area of the eastern spreading basins than in the western basins, (3) the spreading grounds would be capable of accepting a combined total of as much as 80,000 acre-feet (9.9 x 107 cubic metres) per year, and (4) the water being recharged should move through the part of the aquifer composed of river-channel deposits toward the areas of pumpage.
Indian Wells Valley is in a semiarid region of the Mojave Desert. The U.S. Naval Weapons Center at China Lake and nearby communities depend upon an adequate source of ground water for their existence. Much of the ground water is of poor quality. Most of the ground-water pumping occurs in the Inyokern, intermediate, and Ridgecrest areas. The quality of ground water in these well fields is considered excellent for public use. The increasingly larger pumping depressions in the well fields do not seem to have significantly changed the natural flow pattern of the poor-quality ground water in the shallow aquifer toward the China Lake playa. In 1972 the flow pattern of the poor quality ground water was not toward these pumping depressions. The recharge to the ground water of sewage effluent from the U.S. Navy sewage ponds and the Ridgecrest Sanitation District sewage ponds has not significantly affected ground-water quality in the valley. There is no indication that recharge of sewage effluent from these ponds is migrating toward the well fields. The dissolved-solids concentration in the ground water in some areas is increasing slightly, but where this has occurred, it is not yet serious.
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