Abstract: At a 24,000-acre citrus grove, a connector well is proposed as a resource management tool for capturing water normally lost through evapotranspiration and by excess runoff. Such a well would connect the surficial sand aquifer with the deep, highly transmissive limestone Floridan Aquifer. Because of natural head differences, water would move by gravity flow from the sand into the Floridan Aquifer, thus replenishing water withdrawn for irrigation from the Floridan Aquifer. A 70-acre marsh was selected as the test site based on analyses of hydraulic conductivity, porosity, and water quality. Recharge rate through the connector well under steady-state conditions is estimated at 160 gallons per minute. The proposed connector well is designed to have 10-inch screens opposite zones in the 45-foot thick sand aquifer, be cased for 400 feet opposite confining beds and a secondary limestone aquifer, and be open hole for about 250 feet in the Floridan Aquifer. A graded-sand filter pack placed around the screened sections of the well will increase its efficiency.

Abstract: A digital water-quality model of the shallow alluvial aquifer near Barstow was evaluated to determine the applicability of the model computer program to varied hydrolic problems. The evaluation was made on the basis of the data requirements of the model, the characteristics and limitations of the model computer program, the relevance of the model results, and the computer costs associated with the model. Two-well tracer-dilution tests may not be a workable means of determining the aquifer dispersivity and porosity for use in a water-quality model with a large grid interval is under consideration because of the relative insensitivity of such a model to dispersivity. The model results were relevant to the real-life head and water-quality conditions in the aquifer near Barstow and provided an excellent means of evaluating the cause and effect relations associated with ground-water pollution.

Abstract: Eighty-five stream sites in and near the six-county Greater Pittsburgh Region were sampled in mid-June 1971 and again in mid-October 1972. Concentrations of inorganic nitrogen, organic carbon, or phosphorus were high enough to indicate potential problems at about a quarter of the sampling sites. Temperature, dissolved oxygen, and pH values indicated a generally favorable capacity for recovery from degradation, although a number of streams east of the Allegheny and Monongahela Rivers are marginal or lacking. Regionally, sulfate is the dominant ion and was observed in concentrations of 40 milligrams per liter or more at 90 percent of the sites. Bicarbonate exceeded 100 milligrams per liter at 22 sites. A moderate to high degree of mineralization is indicated by conductance readings of more than 500 micromhos per centimeter at half of the sampling sites.

Abstract: ^ digital computer model was used to model an unconfined sandstone aquifer (Arikaree aquifer) in about 340 square miles (880 square kilometers) in southeastern Wyoming. The model was calibrated by comparing observed and calculated changes in the potentiometric surface and leakage from the aquifer along streams during water year 1974. The comparison was fairly good for changes in the potentiometric surface and was good for leakage. The calibrated model was used to predict changes in the potentiometric surface and leakage through water year 1979, assuming no new ground-water development after 1974 and normal recharge to the aquifer. Water-level declines of as much as 14 feet (4.3 meters) were predicted, but much of the area would be relatively unaffected. The total predicted decrease in leakage between water years 1974 and 1979 was about 500 acre-feet (0.6 cubic hectometer) per year; the greatest decrease was predicted along streams closest to areas of pumpage.

From introduction: The primary objective of this study was to determine the net transport of zinc into the study area from urbanized perimeter, out of the study area across the northern boundary of the study area, and across the sediment-water interface within the study area, all within a limited time period. A secondary objective was to assemble as much data on other trace metals--their concentrations and chemical states in water, suspended solids, sediments and interstitial fluids--as possible within the time and funding constraints of the study in order to describe the existing trace metal conditions in the south bay. Thus the bulk of effort was directed toward evaluating the distribution and movements of zinc, but the data collected on the distribution and movements of zinc, but the data collected on the distribution of other metals is important and is reported here.

From abstract: This report presents the theory and method of calculation used by MIX2, describes the input to the program, presents results of two test cases, and provides a program listing.

Abstract: The route of the partly completed Cross-Florida Barge Canal follows the St. Johns, Oklawaha and Withlacoochee Rivers. If the canal is ·completed, the Summit Reach, connecting the Oklawaha and Withlacoochee Rivers will be excavated into the Floridan aquifer. Large springs that discharge from this limestone and dolomite aquifer flow to the Oklawaha and Withlacoochee Rivers.

From introduction: The North Coast Limestone area is one of the two most important ground-water provinces of Puerto Rico--the other being the South Coast Alluvial aquifer. The investigation of the water resources of the South Coast has progressed to the point that at this time (mid-1971) an electric-analog model of the area is being prepared. The hydrology of the North Coast Limestones, however, was never investigated as a whole before this investigation, and, therefore, this study was designed to assess the most important hydrolic features of the area.

Report discussing the probable impact of urban development on the magnitude and frequency of flooding in the lower reaches of the Walnut Creek basin. (from Abstract)

Purpose and scope: This reports presents the results of a 2-year investigation by the U.S. Geological Survey, in cooperation with the city of St. Petersburg, to evaluate geohydrologic conditions at a landfill in a coastal area. The report defines and describes the geologic and geohydrologic units underlying the landfill, and examines the controls these units exert on the flow and quality of surface and ground water in the area. The study increases the understanding of the geohydrologic aspects of landfill operations and will be helpful in the selection of future landfill sites in similar coastal areas.

From purpose and scope: The study was made to obtain baseline data for the island (Shelter Island) and as part of a larger study of shallow ground-water quality in Suffolk County, New York.

Report and geological survey. This report examines the effects of phosphate mining in Osceola National Forest, a 245-square mile area in Columbia and Baker Counties, Florida. It includes maps, graphs, and tables.

From introduction: The purpose of this report is to describe low-flow characteristics of streams in the lower Wisconsin River basin where streamflow data have been collected and to present equations for estimating low-flow characteristics and ungaged sites.

Abstract: Unconsolidated strata of clay, silt, sand, and gravel of Late Cretaceous and pre-Wisconsin Pleistoscene ages lie between crystalline basement rocks (bedrock) of Precambrian (?) age and unconsolidated deposits of late Pleistocene (Wisconsin) and Holocene ages in Queens County, Long Island, N.Y., a borough of New York City. Data collected during a recent study of the hydrogeology of the county and updated records of earlier studies have been used to prepare contour maps that delineate the surfaces of the bedrock and the Upper Cretaceous and pre-Wisconsin Pleistocene deposits. The presence of diabase fragments, apparently from the Hudson Palisades, in a buried valley through the county suggests that the ancestral Hudson River was diverted into Queens County in Pleistocene.

Report and geological survey. This report examines the ground water within the Wet Mountain Valley, Colorado. It includes maps of the area.

From introduction: This report describes some basic principles of hydrology as they apply to Martin County. The major land features of the county are described first, then the hydrologic cycle and the county's surface-water and ground-water resource. Specific problems associated with population growth and the county's development, such as saltwater intrusion and water use, are sited and sections have been included in the report to deal with these problems.

This report applies the transient-flow simulation model to the Sacramento River in California; "the model has demonstrated that it can provide reliable daily mean as well as instantaneous discharge data," among other things. It includes a map, graphs, and tables.

From introduction: The purpose of this report is to describe low-flow characteristics of streams in the Trempealeau-Black River basin where streamflow data have been collected and to present equations useful for estimating low-flow characteristics at ungaged sites.

This report presents the results of testing treated municipal wastewater in Saint Petersburg, Florida. It includes maps and tables.

This report describes results of a study to use stormwater data from four Miami, Florida catchménts to test applicability of deterministic modeling. It includes collected data, graphs, and maps.

Abstract: Most public water supplies sampled in Florida meet the National Interim Primary and Proposed Secondary Drinking Water Regulations. This conclusion is based on a water quality reconnaissance of 131 raw and treated public supplies throughout the State during the period January through May 1979. In a few public supplies, primary drinking water regulation maximum contaminant levels were exceeded for mercury, turbidity, and gross alpha particle activity. Secondary drinking water regulations were also occasionally exceeded in some public supplies for such parameters as chloride, pH, color, dissolved solids, iron, and manganese. These parameters, however, are more related to the aesthetic quality of drinking water than to public health aspects.

From purpose and study: The principal objectives of this study were as follows: (1) to determine the existing water-quality conditions in Lago Loiza as reflected by the principal chemical, physical, biological and bacteriological characteristics in the lake and its tributaries. (2) To estimate the reservoir's water budget during the study period, including the contributions from the tributaries and other sources. (3) Estimation of the reservoir's overall nitrogen and phosphorus budget, including the principal sources and sinks of these nutrients. (4) Definition of the sedimentation rate in the reservoir.

From abstract: This report presents "a water-quality study of the Neuse River, based on data collected during 1956-77 at the U.S. Geological Survey stations at Clayton and Kinston, employs statistical trend analysis techniques that provide a framework for river-quality assessment." It includes maps, graphs, and tables.

This report proposes three locations in two Florida counties "for regional monitoring of the effects of subsurface injection" on freshwater resources: Pinellas County and Hillsborough County. It contains a table, maps, and graphs.