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Water use in South Dakota during 1985 is estimated to have been 674 million gal/day. This is a slight decrease from the 1980 estimate of 690 million gal/day. Of the total use, 63% was from surface-water sources and 37% was from groundwater sources. About 75% of the total water use...

The N Aquifer is the main source of water in the 5,400 sq mi Black Mesa area in the Navajo and Hopi Indian Reservations in northeastern Arizona. Water in the aquifer is under confined conditions in the central 3,300 sq mi of the area. Maximum saturated thickness is about 1,050...

Regression analysis was used to develop models for estimating mean annual suspended-sediment loads for streams in Colorado. Mean annual suspended-sediment loads at 81 selected streamflow-gaging stations in the central, northwestern, and southwestern regions of Colorado were expressed as functions of geomorphic and hydrologic variables. A multiple-regression model that included mean...

Aquifers in Island County, Washington, that are intruded by seawater from Puget Sound contain chloride concentrations that exceed 100 mg/L. Chloride concentrations exceeded 100 mg/L in 24 % of the wells that were drilled below sea level and sampled in August 1981, but most of the chloride concentrations did not...

From 1953 to 1983, an estimated 0.01 to 0.136 Ci (curies)/year of iodine-129 were contained in wastewater generated by the ICPP (Idaho Chemical Processing Plant) at the Idaho National Engineering Laboratory. The wastewater was directly discharged to the Snake River Plain aquifer through a deep disposal well until February 9,...

The Black Creek aquifer contains dilute seawater near the North Carolina State line, probably the result of incomplete flushing of ancient seawater. Data do not indicate that the dilute seawater has migrated toward areas of fresh ground-water withdrawals. The concentration of chloride in ground-water samples ranges from 5 to 720...

The program named PHRQPITZ is a computer code capable of making geochemical calculations in brines and other electrolyte solutions to high concentrations using the Pitzer virial-coefficient approach for activity-coefficient corrections. Reaction-modeling capabilities include calculation of (1) aqueous speciation and mineral-saturation index, (2) mineral solubility, (3) mixing and titration of aqueous...

Hydrogeologic factors influencing leachate movement from an in-situ oil-shale retort near Rock Springs, Wyoming, were investigated through models of ground-water flow and solute transport. Leachate, indicated by the conservative ion thiocyanate, has been observed ? mile downgradient from the retort. The contaminated aquifer is part of the Green River Formation...

This paper describes the results of a study to determine the geologic and hydrologic factors that control migration of tritium from a closed, low-level radioactive-waste disposal site. The disposal site, which operated from 1943 to mid1949, contains waste generated by research activities at the world's first nuclear reactors. Tritium has...

External quality assurance monitoring of the National Atmospheric Deposition Program (NADP) and National Trends Network (NTN) was performed by the U.S. Geological Survey during 1985. The monitoring consisted of three primary programs: (1) an intersite comparison program designed to assess the precision and accuracy of onsite pH and specific conductance...

Present Mount Shasta, California, area hydrologic characteristics were documented to compare future changes due to land use or volcanic activity. Lower flanks of Mount Shasta consist of broad aprons of pyroclastic-flow, debris flow, and fluvial deposits, with incised channels on upper parts of the mountain. Data include glacial areas and...

Aquifers in coastal areas of Puerto Rico commonly contain limited quantities of freshwater that occur as a thin layer at the surface of the water table. Many wells have been abandoned because well screens were inadvertently placed in saltwater parts of the aquifer. A scavenger/production well couple that can be...

The northern divide of the Susquehanna River basin crosses 29 broad valleys that contain thick glacial deposits but are drained only by small headwater streams. Much groundwater could be withdrawn from sand and gravel deposits in these valleys with little immediate effect on streamflow. A digital model of the headwater...

Predicting the fate of organic compounds in streams and rivers often requires knowledge of the volatilization characteristics of the compounds. The reference-substance concept, involving laboratory-determined ratios of the liquid-film coefficients for volatilization of the organic compounds to the liquid-film coefficient for oxygen absorption, is used to predict liquid-film coefficients for...

The characteristics and distributions of near-surface bottom sediments and of nutrients in the sediments provide information on modern sediment and nutrient sources, sedimentation environments, and geochemical reactions in the tidal Potomac system, Maryland and Virginia. This information is fundamental to an improved understanding of sedimentation and eutrophication problems in the...

Five principal creeks, First Creek, Second Creek, Wood Creek, Third Creek, and Incline Creek, having a cumulative drainage of 17.8 square miles, furnished a yearly average of about 15,000 acre-feet of runoff, mainly snowmelt, to Lake Tahoe during the 1970-73 water years. Annual runoff from the individual streams ranged from...

Differing capacities of plant species to tolerate drought and salinity are causative factors for presence of species and communities in various habitats. It is proposed that minimum xylem pressure potentials measured are indicative of drought tolerance and that minimum cell osmotic potentials are indicative of salt tolerance of plant species....

No abstract available. ...

Twenty-four wells were constructed at nine sites at Bear Creek Valley to provide geologic and hydrologic information. Lithologic samples and suits of geophysical logs were obtained from the deepest boreholes at six of the sites. Two of these boreholes at the base of Chestnut Ridge were completed in the Maynardville...