From introduction: The purpose of this report is to describe the general quality and quantity of water in the principal water-supply aquifers in Minnesota.

The model discussed in this report simulates recharge to, flow through, and discharge from the water-table aquifer representative of most of Chester County, Pennsylvania. It includes maps and graphs.

Abstract: Concentrations of nitrate, chloride, and total sol ids in water in the Magothy aquifer, southeast Nassau County, N.Y., show a steadily increasing trend from the early 1950's to 1973. Vertical distribution of nitrate, chloride, and total-solids concentrations as shown in sections of the study area indicate downward movement of these constituents. Maximum concentrations are in a zone underlying the areas of Westbury, Hicksvil.le, and Plainview. Nitrate (as nitrogen) concentration increased from 4-5 milligrams per liter to 7 milligrams per liter in the area of Westbury and from 3 to 10 milligrams per liter in Plainview during the period 1950-73. During this same period, a 10 milligram-per-liter line of equal-chloride concentration on a cross section in the Westbury area moved downward a distance of less than 50 feet (15 meters), and in the area of Hicksville nearly 150 feet (45 meters). Total-solids concentration doubled in the area of Plainview, where maximum downward movement of pollutants was observed.

From introduction: The objective of this project is to measure the impact coal mining has on the hydrologic system and to develop the capability for predicting the effect of future mining on water resources. To achieve this necessities isolating the problems and measuring the parameters involved before, during, and after mining.

Abstract: The primary effect of a floodwater-retarding structure (FRS) on the flow of Trout Creek, Wisconsin, is attenuation of flood peaks. Reduction of flood peaks ranged from 58 to 91 percent during the study period, 1975 to 1979. An inverse relationship exists between sediment concentration and outflow from the FRS during floods. Most sediment stored in the flood pool during floods is released from the reservoir during subsequent reduced discharge. Sediment-trapping efficiency of the FRS was 7 percent during the 4-year study. The bankfull capacity of the channel was reduced from 154 cubic feet per second upstream from the FRS to 65 cubic feet per second downstream. Mean bankfull depth downstream from the FRS has adjusted to a value 45 percent less than upstream from the structure due to the sedimentation of materials transported from the FRS during reduced flows. The FRS was not found to have any significant adverse effect on the arthropod fauna or trout reproduction in Trout Creek from 1975 to 1979. During 1960-1979, winter floods seem to have had the greatest adverse effect on the survival of brown trout eggs and sac fry.

This report evaluates and describes the effects that strip mining the Anna S. Mine has on the water quality of Babb Creek in Pennsylvania. It includes maps, graphs, and tables.

This report uses data collected from seventeen lakes and ponds in Eagan, Minnesota from 1972 through 1978 to determine the effects of urbanization on water quality. It contains a map, graphs, and tables.

From introduction: The purpose of this report is to assemble empirical data on longitudinal dispersion for a variety of natural channels as a first step in the critical examination of current models used to describe longitudinal dispersion.

From abstract: This report evaluates "four dam-break flood-wave models [...] by using three field data sets and selected criteria of desirable features." It includes maps, graphs, and tables.

From purpose and scope: The purpose of this study was to update hydrologic data and refine understanding of the hydrologic system within the San Dieguito, San Elijo, and San Pasqual hydrologic subareas in San Diego County, Calif., and to evaluate the suitability of these areas for reclaimed water use.

From introduction: This study is limited to four U.S. Geological Survey stream-flow stations located in Idaho (figure 1). The 6 to 22 years of stations were assembled and evaluated through use of computer techniques for data plotting and regression analysis developed by Steele (1972). Objectives of this evaluation were were (1) to show which parameters were highly correlative with the levels of specific conductance and(or) discharge and (2) to see if any changes in overall chemical character of the stream had occurred over the long term.

Abstract: A facility consisting of a circular recharge basin 6.10 meters in diameter with a central observation manhole was developed on Long Island to study the role of the unsaturated zone during aquifer recharge with tertiary-treated sewage. The manhole extends through most of the 7.5-meter-thick unsaturated zone, which is composed of glacial outwash sand and gravel, and enables collection of water samples and monitoring of dynamic characteristics of the unsaturated zone during recharge experiments. The system contains instrumentation for monitoring infiltration rate, pressure-head distribution, soil-moisture content, ground-water levels, and soil gases. The 24.55-square-meter recharge basin has operated in all seasons intermittently since April 1975 and, as of April 1978, has transmitted 62 million liters of tertiary-treated effluent to the water-table aquifer. Overall performance of the facility indicates that it is suitably designed for monitoring the unsaturated zone during artificial-recharge experiments.

From introduction: The purpose of this study is to simulate the hydrology of the Farrington aquifer using a computer-simulation model so that the effects of alternative withdrawal schemes can be evaluated quantitatively. The primary study area consists of the northern part of the New jersey Coastal Plain...This report discusses the geohydrology of the Farrington aquifer, the simulation model, and the effects of projected withdrawals from the Farrington aquifer.

From purpose and scope: The purpose of this report, prepared by the U.S. Geological Survey in cooperation with the Napa County Flood Control and Water Conservation District, is to provide local planners with sufficient data to permit them to manage effectively the local ground-water resources for long-term use.

From introduction: This report contains a general description of the hydrology of the project site, summaries of the data collected during 1971 to 1978, and discusses some of the factors affecting the hydrology of the site. This information and the water-level contour map (Fuentes and Patterson, 1979) will be helpful in designing an effective ground-water monitoring program and will provide baseline hydrologic information from which future changes can be detected.

Abstract: The three lakes investigated gain water- from adjoining water-table aquifer and lose water to Floridan aquifer by downward leakage. Net seepage (net exchange of water between lake and aquifers) can be estimated by equation S = AX + BY, where S is net seepage, X represents hydraulic gradient between lake and water-table aquifer, A is lumped parameter representing effect of hydaulic conductivity and cross-sectional area of materials in flow section of water-table aquifer, Y is head difference between lake level and potentiometric surface of Floridan aquifer, and B is lumped parameter representing effect of hydraulic conductivity, area, and thickness of materials between lake bottom and Floridan aquifer. If values of S, X, and Y are available for two contrasting water-level conditions, coefficients A and B are determinable by solution of two simultaneous equations. If the relation between lake- and ground-water level is same on all sides of the lake with regard to each aquifer and if X and Y are truly representative of these relations, then X and Y terms of equation provide valid estimates of inflow to lake from water-table aquifer and outflow from lake to Floridan aquifer.

From introduction: This study was begun in 1967 in cooperation with the Wisconsin Department of natural Resources (DNR)--its purpose was to evaluate the effects of construction of a reservoir and a floodwater-retention structure on the hydrologic system and water quality in a small basin in southwestern Wisconsin. In 1968, Federal research funds were obtained to provide for more detailed study of water quality and to extend the scope of the study to include aquatic biota.

Abstract: The various components of inflow and outflow to and from the lake and their relative magnitudes were identified. In 1972 water year the total inflow to the lake was 200,000 acre-feet, but it was only 75,000 acre-feet in 1973 water year. In 1972 water year the Donner and Blitzen River contributed 55 percent of the inflow, with Silvies River, direct precipitation, and Sodhouse Spring contributing 28, 13, and 4 percent respectively. Om 1973 the Donner and Blitzen River contributed 61 percent of the inflow. The Silvies River, direct precipitation, and Sodhouse Spring contributed 1, 25, and 12 percent respectively. Ground-water inflow, other than Sodhouse Spring, appears to be negligible. In 1972 water year, 81 percent of the outflow was by evapotranspiration and 19 percent was surface outflow through The Narrows. In 1973, 96 percent of the outflow was by evapotranspiration and 4 percent was surface outflow through The Narrows. Ground-water outflow is negligible.

Samples of water, fish, and benthic macroinvertebrates collected at 10 sampling stations over a 10-month period indicate that Sacony Creek and its major tributaries possess water of good to excellent quality. No excessive quantities of dissolved nutrients, oxidizable matter, or fecal coliform bacteria were detected. Fish inhabitants include a sizable wild trout population in the upper Sacony basin and a diverse warm-water population, dominated by white suckers (Catostomus commersoni), in the lower basin. A population of 590 trout or 119 pounds per acre (133 kilograms per square hectometer) was estimated for good habitat in the upper basin. A maximum standing crop of 558 pounds per acre (626 kilograms per square hectometer) was measured at' one of the more productive reaches. Benthic macroinvertebrate collections tended to support the water chemistry and fish population studies. Diversity (d) and Redundancy (r) ranged from 2.44 to 3.46 and 0.14 to 0.38, respectively. Such diversity and redundancy values indicate good quality water at all stations.

This report presents "low-flow characteristics of streams in the Rock-Fox River basin" in Wisconsin. It includes maps and tables.

This report presents the results of water sampling in two New York counties and concludes that the possibly cause of fluctuations of chloride, sulfate, and nitrate in the water are "precipitation, lawn fertilizer, dissolved salts from storm runoff, and effluent from septic tanks and cesspools." This report also includes a number of maps and graphs.

From abstract: This report "presents PHREEQE, a Fortran IV computer program designed to mode1 geochemical reactions and calculate pH, redox potential, and mass transfer as a function of reaction progress. "It contains tables and other figures.

From abstract: This report provides "hydrologic information for the north-central and western coal-mining regions of Missouri . . . to define the hydrologic system in these areas of major historic and planned coal development." It "describes the physical setting, climate, coal-mining practices, general hydrologic systems, and the current (1980) hydrologic data base in these two coal-mining regions."

From explanation: This map is based on water level measurements made in wells screened in the Eocene Memphis Sand (formerly "500-foot sand"). Monthly low-water levels for the month of August, 1978 from USGS maintained recorder equipped wells and supplemental measurements made on August 22 and 23 of private and industrial wells were used as control. Water levels are commonly at their lowest for the year during late August of early September (Criner and Parks, 1976).