Showing papers in "Water-Resources Investigations Report in 1983"

Precipitation-runoff modeling system; user's manual

Abstract: From introduction: This documentation is designed to provide the user with the basic philosophy and structure of PRMS, instructions for application of established models designed as cataloged procedures, and instructions for interaction with the PRMS library to permit user additions or modifications of model components. The components and subroutines described in this document are those available at the time of publication. However, the library is dynamic and will be enhanced and updated through time. This manual will be updated to reflect major additions and changes through manual inserts or republications.

Geohydrology of the proposed Waste Isolation Pilot Plant site, Los Medanos area, southeastern New Mexico

Abstract: From purpose and scope: This report discusses the ground-water systems and the interpretation of test results in the water-bearing zones above and below the proposed facility, Waste Isolation Pilot Plant (WIPP) in Los Medanos.

Sediment transport in the Tanana River near Fairbanks, Alaska, 1977-79

Abstract: : Suspended-sediment- and bedload-transport rates for the Tanana River near Fairbanks, Alaska, can be related to water discharge, and annual sediment loads can be computed using these relations. For a site near Fairbanks, the average annual (1974-79) load is 24 million metric tons of suspended sediment and 321,000 metric tons of bedload. Upstream, near North Pole, the average annual load is 20.7 million metric tons of suspended sediment and 298,000 metric tons of bedload. For both sites bedload is usually 1 to 1.5 percent of suspended-sediment load. Particle-size distribution for suspended sediment is similar at Fairbanks and North Pole. Median particle size is generally in the silt range, but at some low-water discharges, it is in the very fine sand range. Median particle size of bedload near North Pole is generally in the gravel range, but at some low transport rates, it is in the medium sand range. In 1977 median bedload particle size was comparable at the two sites, but in 1978 the median size was markedly smaller at Fairbanks. In 1979 generally coarser material was transported at both sites, but the difference in bedload particle size was even greater between the sites. At both locations and all water discharges and sediment-transport rates, suspended-load particles are significantly smaller than bedload particles. At North Pole in 1979, median bed-material particle size was in the coarse gravel range; at Fairbanks it was in the medium gravel range in the main channel but in the fine sand range in the overflow part of the channel. (Author)

Storm runoff as related to urbanization based on data collected in Salem and Portland, and generalized for the Willamette Valley, Oregon

Abstract: Storm runoff as related to urbanization is defined by a series of regression equations for Salem and for the Willamette Valley, Oregon. In addition to data from 17 basins monitored in the Salem area, data from 24 basins gaged in a previous study in Portland, Oregon-Vancouver, Washington were used defining the Willamette Valley equations. Basins used to define equations ranged in size from 0.2 to 26 square mi. Rainfall intensity varied from 1.8 to 2.2 in. for the 6-hour, 0.020 exceedance probability. Sensitivity analyses of equations indicate that urbanization of an undeveloped basin can increase peak discharge more than three times and almost double runoff volume. Much of Portland and Vancouver are located on porous river terraces where dry wells are used to shunt runoff. Much of east Salem is located on previously farmed land where drain tiles used to dewater soils still connect directly to streams.

Water-quality assessment of stormwater runoff from a heavily used urban highway bridge in miami, florida

Abstract: Runoff from a 1.43-acre bridge section of Interstate 95 in Miami, Florida, was monitored during five storms to estimate loads of selected water-quality parameters washed from this heavily traveled roadway. The monitoring was conducted periodically from November 1979 to May 1981 in cooperation with the Florida Department of Transportation for the specific purpose of quantifying the concentrations and loads of selected water-quality parameters in urban-roadway runoff. Automated instrumentation was used during each of the five storms to collect periodic samples of bridge runoff and to measure continuously the storm discharge from the bridge surface and the local rainfall. For most target parameters, 6 to 11 samples were collected for analyses during each event. Results of these analyses generally indicated that the parameter concentrations in the stormwater runoff and the parameter load magnitudes were quite variable among the five storms, although both were similar to the levels reported for numerous other roadway sites. Storm intensity influenced the rate of loading, but parameter concentration was the dominant variable controlling the overall magnitude of loading. (Author)

An assessment of steady-state propane-gas tracer method for reaeration coefficients cowaselon creek, new york

Abstract: From purpose and scope: The purpose of this report is to develop and test steady-state method for the measurement of propane-gas desorption coefficients in a natural channel flow as the first phase of the field assessments of hydrocarbon gas tracer method for reaeration coefficients. Three field tests were conducted in a straight 5.2 km reach of the Cowaselon Creek near Canastota, New York in June, July, and October, 1981.

Geohydrologic data and test results from well J-13, Nevada Test Site, Nye County, Nevada

Abstract: From purpose and scope: The purpose of this report is to present all the previously collected hydrogeologic, geophysical, and hydrochemical data on well J-13, and to reanalyze these data, using newly developed methods of analysis.

Hydrogeology of the Sarasota-Port Charlotte Area, Florida

Abstract: From purpose and scope: The objective of this investigation was to define the hydrogeologic framework of the surficial, intermediate (Tamiami-upper Hawthorn aquifer and lower Hawthorn-upper Tampa aquifer), and Floridian aquifers in the Sarasota-Port Charlotte area, including their regional extent, thickness, hydraulic properties, water quality, and their interrelation in the regional ground-water flow system.

Geology and ground-water resources of Camden County, New Jersey

Abstract: Camden County, New Jersey, is located in the Philadelphia-Camden metropolitan area. The western edge of the county is urban and industrial in character. The central part is less industrial and more suburban in character, and the eastern part is sparsely populated and predominantly agricultural, although urbanization is advancing eastward quite rapidly. Camden County is in the Atlantic Coastal Plain physiographic province. Underlying the county are unconsolidated sediments of Quaternary, Tertiary, and Cretaceous age, consisting of mostly alternating sands, silts, and clays. The sediments dip gently to the southeast and thicken from 40 feet at the Delaware River to 2,900 feet at the Camden-Atlantic County line. Below the unconsolidated sediments is the pre-Cretaceous crystalline bedrock. The major fresh-water aquifers in Camden County are sands and gravels of Cretaceous and Tertiary age in the Potomac Group and the Raritan and Magothy Formations; the Cohansey Sand; the Wenonah Formation-Mount Laurel Sand; and the Englishtown Formation. Minor aquifers are found in parts of the Merchantville Formation, the undifferentiated Vincentown and Manasquan Formations, and the Kirkwood Formation. Saturated sands an.d gravels in the surficial deposits of Quaternary age where in direct contact are commonly hydraulically connected to the underlying aquifers. The rate of ground-water withdrawal for Camden County was 68 mgd (million gallons per day) in 1966. This was the largest average annual county pumpage in the State in 1966. Eighty-five percent (56 mgd) was pumped from the aquifer system in the Potomac Group and the Raritan and Magothy Formations. The potentiometric surfaces of all the major artesian aquifers in Camden County declined from 1900 to 1970 as a result of pumping. The largest decline occurred in the aquifer system in the Potomac Group and the Raritan and Magothy Formations. At Haddon Heights, in the western part of the county, the potentiometric surface declined about 110 feet "from 1900 to 1968. The potentiometric surface of the aquifer in the Wenonah Formation-Mount Laurel Sand declined 43 feet in about 60 years in the vicinity of Berlin Borough. The chemical quality of ground water in Camden County is generally satisfactory for most uses. Concentrations of iron greater than the State's potable-water standard of 0.3 milligrams per liter are found in some areas of the Potomac-Raritan-Magothy aquifer system, in scattered locations in the Wenonah Formation-Mount Laurel Sand, and in the Cohansey Sand. In general, higher values of dissolved solids, sulfate, and chloride occur in water in and near the outcrop ,of the Potomac-Raritan-Magothy aquifer system than downdip in the aquifer. In the southeastern part of the county chloride concentrations in excess of 250 milligrams per liter can be found in the same aquifer system. The high chloride water has remained in the aquifer system from the time of deposition or has re-entered the system from the ocean after changes in sea level since Pleistocene time. Contamination of water in the Potomac-Raritan-Magothy aquifer system in the Philadelphia area has created a potential water-quality problem for the Camden area near the Delaware River. Contaminated ground water in Philadelphia, with high concentrations of sulfate and dissolved solids, is moving under the Delaware River toward Eagle Point in Gloucester County near the Camden County line. Decrease of pumping in Philadelphia and simultaneous increase of pumping in Camden and Gloucester Counties tends to draw ground water from Philadelphia toward New Jersey. The greatest potential for additional ground-water development in the county is from the Cohansey Sand which is generally an unconfined aquifer. The Cohansey also has the greatest possibility of ground-water contamination because of the local effect of wastes from suburban and industrial development and the shallow depth of the Cohansey aquifer.

The Southern Hills Regional Aquifer System of Southeastern Louisiana and Southwestern Mississippi

Abstract: From purpose and scope: The purposes of the investigation were to develop from available information (1) a description of the regional aquifer system serving as a public supply in the Capital Area Ground Water Conservation Commission district, the Florida Parishes of southwestern Mississippi; and (2) to discuss potential alternative sources of freshwater.

Mean annual runoff and peak flow estimates based on channel geometry of streams in southeastern Montana

Abstract: From introduction: The purpose of this report is to describe the channel-geometry technique and to present equations for estimating mean annual runoff and peak flows for ungaged streams in southeastern Montana.

A description of aquifer units in western Oregon

Abstract: Seven aquifer units were delineated for western Oregon by grouping aquifers according to hydraulic and geologic similarities. The bedrock aquifer units in the Klamath Mountains, Coast Range, and Western Cascade Range all have hydraulic conductivities generally less than 2 feet per day and generally yield less than 10 gallons per minute to wells. The Columbia River Basalt Group aquifer unit, which is present along the Columbia River and in the northern Willamette Valley, also has a low hydraulic conductivity of about 5 feet per day; however, the basalt does contain permeable interflow zones and scoriaceous flow tops that transmit water laterally. Well yields from the Columbia River Basalt Group are generally less than 100 gallons per minute. The most important aquifer unit in western Oregon is the Tertiary-Quaternary sedimentary deposits that occur in lowlands throughout the area and provide water for irrigation, industry, public supplies, and domestic and stock uses. Hydraulic conductivity of the most recent alluvium in the aquifer unit is generally 200 to 600 feet per day in the Willamette Valley, and well yields exceeding 2,000 gallons per minute have been reported. At shallow depths, the seven aquifer units generally contain water with low concentrations of dissolved solids. In the Tertiary rocks of the Coast Range, analyses of water from deep wells indicate that water with more than 10,000 milligrams per liter dissolved solids is probably widespread at depths greater than 2,000 feet. INTRODUCTION Objectives and Scope Under the authority of the Safe Drinking Water Act, the U.S. Environmental Protection Agency (ERA) is responsible for development and implementation of an Underground Injection Control (UIC) Program to protect the Nation's ground-water supply from contaminants injected into the subsurface. The U.S. Environmental Protection Agency (1975) regulations state that any aquifer containing water with fewer than 10,000 mg/L (milligrams per liter) of dissolved solids is to be protected. One of EPA's objectives in the UIC Program is to be able to estimate the size of the area around a proposed injection well that could be affected by increased pressures as a result of injection. EPA refers to the area as the "area of review" and defines it as "*** that area the radius of which is the lateral distance from an injection well pattern in which pressure changes resulting from the injection operation may cause the migration of the injection and (or) formation fluid into an underground source of drinking water" (U.S. Environmental Protection Agency, 1979). In Oregon, the U.S. Geological Survey was asked by the EPA to supply hydrogeologic information that will aid in the evaluation of proposals for underground injection. This report deals with aquifers in Oregon west of the Cascade Range crest. The three primary objectives of the project were to (1) delineate and describe the major aquifers, (2) describe the quality of water in those aquifers and identify geologic formations containing water with dissolved-solids concentrations exceeding 10,000 mg/L, and (3) evaluate methods by which the area of review may be estimated for proposed injection wells in western Oregon. During compilation of information for objectives 1 and 2, it became apparent that detailed hydrogeologic data for western Oregon's aquifers are inadequate for making reliable estimates of the area of review at any locality without first obtaining more site-specific data. However, rough preliminary calculations can be made to determine the order of magnitude of the size of the area of review using data tabulated in this report in conjunction with mathematical equations for predicting pressure buildup presented in an EPA publication "Radius of Pressure Influence of Injection Wells," by Warner and others (1979). These rough calculations can be improved using data obtained by test drilling and aquifer testing at the proposed injection site. For a detailed discussion of underground injection, the reader is referred to "An Introduction to the Technology of Subsurface Wastewater Injection," by Warner and Lehr (1977). This report is intended as a general guide for the EPA or other agencies involved in evaluation of proposals to inject waste into the subsurface in western Oregon. It is not intended for use as a sole source of information in evaluating specific sites for underground injection. Detailed information would need to be collected and analyzed on a site-by-site basis to perform such evaluations. 2 Method of Study and Available information Most of the Information in this report is compiled from published reports of the U.S. Geological Survey, Oregon Water Resources Department, and Oregon Department of Geology and Mineral Industries (see Selected References, p. 20-25). Additional data were obtained from western Oregon water well reports and lithologic and geophysical logs of more than 60 exploratory oil and gas wells. Geologic contacts shown on plate 1 and other plates in this report are primarily from the "Geologic Map of Oregon West of the 121st Meridian" (Wells and Peck, 1961). In some areas where more recent studies have been made, contacts from Wells and Peck (1961) were modified slightly. Generally, outcrops with an area I extent less than 1 mi 2 were not included in the plates. An important source of geologic background information is the publication "Geology of Oregon" (Baldwin, 1976). Description of the Area and its Climate Oregon is divided into western and eastern Oregon by the Cascade Range that trends north-south through the State. Approximately one-third of the State lies west of the crest of the range. The Cascade Range is an orographic barrier for eastward-moving oceanic weather systems and is a major drainage divide. Western Oregon has a mild climate and is rather humid with an average annual precipitation that ranges from about 30 in. in lowlands to more than 150 in. in the Cascade Range. Most precipitation occurs in fall and winter. Western Oregon is about 30,000 mi 2 in area and for this study is subdivided into four physiographic divisions: Klamath Mountains, Coast Range, Cascade Range, and WiIlamette Valley (fig. 1). Each division has a distinct geologic and hydrologic setting. Topographically high areas generally receive the most precipitation and, therefore, water available for recharge to the aquifers is greatest in those areas. The Klamath Mountains occupy most of southwestern Oregon and extend southward into northern California. They are rugged, have 2,000 to 5,000 ft of relief and, locally, receive more than 120 in. of precipitation annually (fig. 2). The Coast Range parallels the Oregon coast and extends from the Columbia River on the north to the latitude of Coos Bay, Oreg. on the south where it merges with the Klamath Mountains. The altitude of the crest of the Coast Range averages about 1,500 ft with peaks as high as 4,000 ft. Local areas of the Coast Range receive more than 200 in. of precipitation each year. The Cascade Range includes some of Oregon's highest peaks. The crest of the range averages about 5,000 ft in altitude and a few peaks along the crest rise to more than 10,000 ft. Some of the highest peaks receive more than 150 in. of precipitation annually, most of which falls as snow in the winter. Because of differences in underlying geologic formations, the Cascades are subdivided into two sections, the Western Cascades and the High Cascades. The Western Cascades form the western foothills of the range and are more deeply eroded and lower in altitude than the High Cascades, which are composed of geologically younger volcanic deposits (Peck and others, 1964). 3 0 60 MILES Modified from Dicken (1950) I . .'.i. .' . '. ' I Tl T I i r I 1 0 80 KILOMETERS FIGURE 1. Western Oregon and its physiographic divisions.

Water resources of the Santa Fe River basin, Florida

Abstract: From purpose and scope: The purpose of this report is to present an analysis of the stream-aquifer system of the Santa Fe River basin, including the quantity and quality of water available from each source and their interrelation. Much information is available in previously published reports, but the basin has not been previously evaluated as a hydrologic unit.

Hydrogeology of parts of the Central Platte and Lower Loup Natural Resources Districts, Nebraska

Abstract: Water-level declines of at least 15 feet have occurred in this heavily irrigated area of central Nebraska since the early 1930's, and potential for additional declines is high. To test the effects of additional irrigation development on water levels and streamflow in the area, computer programs were developed that represent the surface-water system, soil zone, and saturated zone of the hydrogeologic system. A two-dimensional, finite difference ground-water flow model of the 3374 square-mile study area was developed and calibrated using steady-state and transient conditions, and three management alternatives were examined. Results indicate that significant additional water-level declines will occur even if there is no additional ground-water development. 35 refs., 18 figs., 22 tabs.

Methods for estimating peak discharge and flood boundaries of streams in Utah

Abstract: From introduction: This report contains methods for estimating peak discharges and flood boundaries of streams in Utah. The peak-discharge information can be used for a wide variety of projects ranging from the design of bridges, culverts, dams, and embankments to detailed flood-plain and flood-insurance studies based on complex hydraulic characteristics of the stream and valley. The equations for estimating flood depth can be used for a simple, rapid approximation of flood-prone areas.

BASE FLOW OF STREAMS IN THE OUTCROP AREA OF SOUTHEASTERN SAND AQUIFER: South Carolina, Georgia, Alabama, and Mississippi

Abstract: From purpose and scope: The purpose of this study are to derive base flow estimates for representative parts of the Cretaceous and Tertiary clastic outcrop area as an aid in estimating recharge to the sand aquifers; to use base flow relations to estimate aquifer hydraulic parameters; and to relate the lithology of the aquifer to the streamflow duration curves.

Subsurface storage of freshwater in south florida: a prospectus

Abstract: Public agencies in south Florida have investigated various means for increasing the storage capacity of the water-management system, such as injection of freshwater into brackish aquifers, because of concern that increased demand during future dry seasons might cause water-supply deficiencies. In most parts of south Florida, freshwater deficiency usually becomes manifest as the encroachment of saline water into well fields. In some localities, it means the complete absence of natural ground-water supply. Surplus freshwater for injection might be available during the wet season from the same surface and subsurface sources that may become deficient in their capacity to supply local needs during the dry season. Quantification of the amount of surplus freshwater available from a given source requires site-specific analyses. The chemical composition of the surplus water and its proximity to the location of use or to an intervening conveyance system determine whether it is a suitable source for injection. Most of south Florida is underlain by saline, permeable artesian zones which have potential for freshwater storage. These are in the Avon Park, Ocala, Suwannee, and Tampa Limestones, and in the Hawthorn Formation. Experimental freshwater injection tests have been performed with varying degrees of success at five locations, in which surplus water has been stored in either the Avon Park, the Suwannee, or the Hawthorn. A determination of the feasiblity of cyclic freshwater injection at a selected site begins with an assessment of the suitability of local geologic conditions, guided by a knowledge of regional hydrogeology. Feasibility can only be established by actual injection and recovery tests, because some aquifer characteristics affecting freshwater movement during inflow and outflow (degrees of flow uniformity, anisotropy, and hydrodynamic dispersion) are not measurable with standard techniques. Injection and withdrawal tests determine recovery efficiency, the measure of the success of the operation. This is defined for each cycle as the percentage of injected freshwater that can be recovered before the dissolved solids exceed Secondary National Drinking Water Standards. As recovery efficiency improves during the first few cycles, several similar injection and withdrawal tests should be performed in succession. Computer simulations have been made to elucidate the relation of recovery efficiency with various hydrogeologic conditions and with design and management factors. The hydraulic characteristics of the injection zone determine the maximum practical injection capacity of a single well. This, together with the recovery efficiency obtained from a test injection well and local water-supply requirements, determines the number of wells required and the cost-effectiveness of the proposed system relative to other water-supply or conservation alternatives.

Effects of specific land uses on nonpoint sources of suspended sediment, nutrients, and herbicides, Pequea Creek basin, Pennsylvania, 1979-80

Abstract: The Susquehanna River Basin Commission and the U.S. Environmental Protection Agency cooperated with the U.S. Geological Survey in a study to quantify nonpoint-source loadings from an agricultural area in Pennsylvania. Pequea Creek, a tributary to the Susquehanna River, drains a 154-square mile agricultural area in Lancaster County, Pennsylvania. Previous studies defined the Pequea'Creek basin as a contributor of sediment, nutrients, and pesticides from nonpoint sources to the Susquehanna River. The purpose of this intensive watershed investigation was to determine the effects of various land uses on water quality of receiving streams. Streamflow was measured and monthly base-flow samples and water-weighted composite storm samples were analyzed for suspended sediment, nutrients, organic carbon, and triazine herbicides. Constituent loadings were calculated to quantify their discharge from the entire Pequea Creek basin and from four specific subbasins: forest, cornfield, rural residential, and pasture. Soil samples were analyzed for nutrients and selected herbicides, and land use and application data were collected to determine the source of loadings. Precipitation amounts and chemistry were also measured. Precipitation and streamflow were below average for much of the investigation period, May 1979 to December 1980. The annual precipitation for 1980 was 10 inches below normal, with drought conditions the last half of the year. During base flow, the highest concentrations of individual constituents generally observed were: 4.0 milligrams per liter total organic nitrogen and 1.4 milligrams per liter total phosphorus from the downstream pasture site; 24 milligrams per liter total nitrate nitrogen and 3.9 micrograms per liter total atrazine from the cornfield site; and 0.5 micrograms per liter total prometone, and 2.3 micrograms per liter total simazine from the residential site. Nearly all total nitrate nitrogen concentrations from the cornfield site during base flow were about double the U.S. Environmental Protection Agency (1977) criterion of 10 milligrams per liter. The highest constituent concentrations found in composite storm samples were nearly all in samples from the cornfield site. The highest concentrations found were: 16,000 milligrams per liter suspended sediment, 54 milligrams per liter total organic nitrogen, 41 milligrams per liter total nitrate nitrogen, 19 milligrams per liter total phophorus, and 200 micrograms per liter total atrazine. The highest concentrations found in composite storm samples for total prometone was 6.4 micrograms per liter at the residential site and for total simazine was 4.8 micrograms per liter at the downstream pasture site. Generally, concentrations of all the constituents, except nitrate, were higher during storms than during baseflow at all sites. Total concentrations of the constituents increase during storms predominantly due to increases in suspended concentrations. The highest storm concentrations of most constituents occurred at the cornfield site. Fertilizer and herbicide applications increase the available sources of nutrients and herbicides for transport to the stream. The highest phosphorus, atrazine, and suspendedsediment concentrations at the cornfield site occurred during intense storms soon after application and planting. Constituent yields (tons per square mile) from storms, about evenly distributed throughout the basin, were compared from the other specific landuse sites to the forest site, which represents a relatively undisturbed land use. During storms, yields for suspended sediment, total organic nitrogen, and total phosphorus were highest for the pasture and lowest for the forest site. Total nitrate-nitrogen yields were highest for the cornfield and about the same for the forest and residential sites. Yields of total organic carbon were about the same for the cornfield and residential sites, which were both slightly higher than the forest site. The total loads discharged into the Susquehanna River from Pequea Creek from January 1 to December 31, 1980 with 100,000 acre-feet of water were: 12,000 tons of suspended sediment, 840 tons of nitrate nitrogen, 72 tons of organic nitrogen, 21 tons of phosphorus, 540 tons of organic carbon, 93 pounds of atrazine, 52 pounds of simazine, and 5.0 pounds of prometone. Loads for 1980 were much lower than loads for 1978 and 1979 from the Pequea Creek basin, due to below normal precipitation. A comparison of data from Pequea Creek at Martic Forge and the Susquehanna River at Harrisburg shows that during some months, Pequea Creek significantly increased the loads of nitrate nitrogen and suspended sediment of the Susquehanna River. INTRODUCTION The Susquehanna River Basin Commission and the U.S. Environmental Protection Agency cooperated with the U.S. Geological Survey in a study to quantify nonpoint-source loadings from an agricultural area in Pennsylvania. Eutrophication and toxic substances are primary water-quality problems in the Chesapeake Bay (Chesapeake Bay Program, Environmental Protection Agency, written commun. 1982). The lower Susquehanna River basin has been identified as a primary source of sediment and nutrients to the Upper Chesapeake Bay (Clark and others, 1973, 1974). Levels of suspended sediment, nitrogen, and phosphorus in the past have been controlled only by regulating the quality of point discharges from industries and waste-water treatment plants. However, it has become evident that, in many areas, regulation of all point discharges cannot reduce levels of these constituents in receiving streams to acceptable limits. Therefore, nonpointsource loadings need to be investigated. Because agriculture was suspected of contributing much of the sediment and nutrients to the lower Susquehanna River and the Chesapeake Bay, a study of nonpoint-source discharges from an agricultural area was conducted from 1977 to 1981. Pequea Creek was selected for an investigation because the basin is typical of agricultural areas in southeastern Pennsylvania, and is a significant nonpoint-source contributor of suspended sediment, nitrogen, and phosphorus to the Susquehanna River (Ward and Eckhardt, 1979). Loads of these constituents and of triazine herbicides increased significantly during storms. High nitrate nitrogen concentrations during base flow in streams sampled from 1977 to 1979 (Ward and Eckhardt, 1979) tend to confirm studies in Lancaster County (Poth, 1977) which showed widespread nitrate nitrogen contamination of ground-water supplies. Contamination is generally confined to areas underlain by limestone and dolomite, as is most of the Pequea Creek basin. The factors found most influential in determining the transport of these nonpoint constituents are rainfall, runoff, and farming practices. The purpose of this study was to determine the effects of agricultural practices and other land uses on water quality of receiving streams in the Pequea Creek basin by measuring streamflow and concentrations of suspended sediment, nutrients, organic carbon, and herbicides during various hydrologic conditions. Information concerning land use, application rates, and soil data were used to determine sources of loadings. Precipitation quantities and chemistry were also measured. This report presents the results of data collected from May 1979 to December 1980. For ease in comparison of data, all references to species of nitrogen and phosphorus in this report are to be considered in their elemental form. For example, regardless of whether ammonium or nitrate is being discussed, the values and discussion all refer to their concentrations expressed as nitrogen. The information in this report should be useful to water managers and the agricultural community. Also, the Chesapeake Bay Program is using the data to develop runoff, transport, and routing models that can simulate water quality in the Chesapeake Bay and its major tributaries. Acknowledgments The authors acknowledge the dedicated efforts of many U.S. Geological Survey employees both in the field and laboratory, which enabled the successful completion of this study. Mr. Charles Takita and Mr. John Hauenstein of the Susquehanna River Basin Commission provided continuing technical and field assistance. The Chesapeake Bay Program, U.S. Environmental Protection Agency, spent many weeks identifying and digitizing land uses on aerial photographs to develop land use maps for the study area. The Pesticide Research Laboratory, Pennsylvania State University, analyzed soil pesticides. Mr. Marvin Herr and Mr. Kenneth Groff provided continuous land-use and application data for sites located on their properties. General Basin Factors Affecting Streamflow and Constituent Transport The Streamflow and water-quality characteristics of streams are affected by numerous factors. These include physiography, geology, soils, climate, land use, and land cover. Pequea Creek basin is in the southern part of the Conestoga Valley, a carbonate and shale section of the Appalachian Piedmont. The 154-mi2 basin is long and narrow and stretches about 60 mi from the Welsh Mountains to the Susquehanna River (fig. 1). Basin slopes are mostly less than 15 percent. Most of the basin is underlain by limestone and dolomite of Ordovician and Cambrian age. There is quartzite, schist, and gneiss of Cambrian and Precambrian age along the northeast border and schist of early Paleozoic age along the southern border of the basin. Most soils are classed as silt loams belonging to the ConestogaHollinger, Duffield-Hagerstown, and Chester-Glenelg associations. They are productive, well-drained soils that have high moisture-holding capacities (U.S. Dept. of Agriculture, 1956). Because of intense farming practices, the soils are generally classified as moderately eroded with some cases of severe erosion. The growing season generally lasts from May 3 to October 10 and averages 160 days. Monthly mean temperatures during the stud

Evaluation of water levels in major aquifers of the new jersey coastal plain, 1978

Abstract: From purpose and scope: The purpose of this report is to document and evaluate water levels and changes in water levels in the major artesian aquifers of the New Jersey Coastal Plain. Fundamental data for ground-water investigations and management are provided.

Distribution of chloride concentrations in the principal aquifers of the New Jersey coastal plain, 1977-81

Abstract: From abstract: The U.S. Geological Survey maintains a saltwater monitoring network in New Jersey to document and evaluate the movement of saline water into freshwater aquifers that serve as sources of water supply. This report delineates areas in the Coastal Plain where existing or potential saltwater intrusion exists.

Geology of the "20-foot" clay and gardiners clay in southern nassau and southwestern suffolk counties, long island, new york

Abstract: Purpose and scope: This report depicts in detail the areal extent, altitude, thickness, and lithology of the "20-foot" clay and Gardiners Clay (the two thickest and most extensive near-surface confining layers in the area) and redefines the surface of the geologic units that directly underlie these clay units at various locations--the Matawan Group-Magothy Formation, undifferentiated, the Monmouth Group, and the Jameco Gravel.

Hydrology of the Little Androscoggin River Valley aquifer, Oxford County, Maine

Abstract: The Little Androscoggin River valley aquifer, a 15-squaremile sand and gravel valley-fill aquifer in southwestern Maine, is the source of water for several towns in Oxford County. The saturated thickness of coarse-grained deposits that make up the aquifer ranges from about 10 feet near the boundaries to 100 feet. Deposits up to 200 feet in thickness of clay and silt underlie the aquifer in the southern part of the study area. The northern part of the aquifer rests on till and bedrock. Average inflows to the aquifer during the 1981 water year were 16.4 cubic feet per second from precipitation directly on the aquifer, 11.2 cubic feet per second from till-covered uplands adjacent to the aquifer, and 1.4 cubic feet per second from surface-water leakage. Average outflows from the aquifer during the 1981 water year were 26.7 cubic feet per second to surface water and 2.3 cubic feet per second to wells. Analyses of data collected to describe background water quality of the aquifer show that the water is of excellent quality and suitable for use as a drinking water supply. The average dissolved-solids concentration was 67 milligrams per liter, and average total organic carbon concentration was 1.1 milligrams per liter. The only constituents found to exceed recommended standards for drinking water were dissolved iron (two wells) and dissolved manganese (5 wells). Analyses of data collected to describe localized contamination of aquifer water show the effects of landfill leachates and highway road salt on water quality. Dissolved solids in ground water downgradient from one disposal site was more than ten tiE.es higher than average background levels. Dissolved chlorides and sodium concentrations more than three times average background levels were observed in a dug well close to a highway that is subject to salting during winter. These localized contamination sources have increased concentrations of constituents above permissible drinking water limits. A finite-difference ground-water flow model was used to simulate conditions observed in the aquifer during 1981. Model simulations indicate that a 50-percent reduction of average 1981 recharge would cause water-level declines of up to 20 feet in some areas. Model simulations also indicated that increased pumping in the northern part of the aquifer will not cause changes sufficient in the water-table slope to intercept ground water contaminated by a sludge-disposal site. INTRODUCTION The Little Androscoggin River valley aquifer extends from West Paris in the north to Mechanic Falls in the south, a distance of about 15 miles (fig. 1). The aquifer varies in width from less than one mile near South Paris to slightly greater than two miles near the town of Oxford. The aquifer consists of sands and gravel deposited during the last glacial period. Three towns--South Paris, Oxford, and Norway--(combined population about 13,500) use water from the aquifer for municipal supply. In addition, numerous rural domestic wells tap the aquifer. Land-use activities threatening water quality in the aquifer include sanitary landfills, a sludge-disposal site, and road-salting operations. Purpose and Scope of Investigation To gain a better understanding of the ground-water resource available from this aquifer, the U.S. Geological Survey, in cooperation with the Maine Geological Survey, Maine Department of Human Services and the Androscoggin Valley Regional Planning Commission (AVRPC), conducted a study from May 1980 through October 1982. The objectives were to: (1) determine the quantity and quality of water available from the Little Androscoggin River valley aquifer; (2) develop a better understanding of how ground-water moves through the aquifer, and (3) analyze effects of imposed stress on the aquifer. Acknowledgment s The author wishes to express his appreciation to the South Paris, Norway, and Oxford water utilities for their help during this study. Dave Bjerklie, formerly of the AVRPC, provided assistance during the data-collection phase of the study. The surficial geology of the area was remapped by Glenn Prescott of the U.S. Geological Survey. Thanks are also extended to town officials and the many private citizens who granted permission to drill test holes, run seismic surveys, and sample and test wells. 117 » ' South Paris '-> 119 ^> Little Androscoggin River Valley Aquifer 10 MILES 10 15 KILOMETER! Base from U.S. Geological Survey 1:250,000 Quadrangle, Lewiston 1969. 100 MILES 0 160 KILOMETERS INDEX MAP OF MAINE Base from U.S. Geological Survey Figure 1. Location of the study area Previous Investigations Hanley (1959) mapped the surficial geology of the southeastern part of the study area in the Poland quadrangle. The bedrock geology of the area was mapped by Creasy (1979a,b). Prescott (1967, 1968) mapped the surficial geology of the area and presented hydrologic data. Geohydfologic conditions were described by Prescott and Attig (1977). The geohydrology of the South Paris sludge disposal site was investigated by the EPA (U.S. Environmental Protection Agency) (1977), the MDEP (Maine Department of Environmental Protection) (1980) , and by the Environmental Assessment Council, Inc. (1979). The hydrogeology of the South Paris landfill site was also investigated by the MDEP (1980). A time-of-travel study was conducted on the Little Androscoggin River by Nichols and others (1981) . Methods of Investigation Fieldwork for the study ran from June 1980 through December 1981. During this time, a well and spring inventory was conducted in the study area. Wells, test holes, and springs where geohydrologic data were collected are shown on plate 1. Sixty test holes were drilled as part of this study. Split spoon samples were taken every 5 feet below the water table at each test hole where possible. Observation wells were installed in 56 of the 60 test holes. Water levels were measured monthly at 79 locations in the aquifer and continuously at one location. All wells in the monthly network were leveled in to the NGVD of 1929. Numerous miscellaneous water-level measurements were also obtained from private wells during the well inventory. Samples were collected from test holes throughout the study area for grain-size analysis. Saturated thickness and bedrock elevations were determined from seismic refraction data. Eight miles of seismic-refraction profiles were completed at 28 sites, and a detailed surficial geology map of the area was constructed. To determine inflows to the Little Androscoggin River in the study area and to monitor outflow from the area, two continuous surface-water monitoring gages and two daily reading gage sites were installed. Two seepage runs were conducted during base-flow conditions. Precipitation data were collected during 1981 at two sites in the study area. Seventy-two ground-water samples were collected for determination of dissolved inorganic chemical constituents from 56 wells and springs in the area. Samples obtained from municipal supply wells were analyzed for trace constituents, as were samples obtained near the South Paris sludge-disposal site. Two sets of samples were collected at 10 surface-water sites in the study area. The samples were analyzed for common dissolved inorganic, trace, and biological constituents. A two-dimensional digital-computer model of ground-water flow in the aquifer was constructed to simulate conditions observed during the 1981 water year and to examine effects of pumping on the aquifer. Well and Site-Numbering System Wells, springs, and test holes in Maine are numbered consecutively by county. Each local well number consists of a letter (or letters) designating county, and a number, for example 0-1216. If two wells are located at the same site, this would be indicated by another number after the original well number, for example 0-1217-8. Wells and springs inventoried as part of this study begin with the numbers 0-1215 in Oxford County and An-1070 in Androscoggin County. Wells with numbers smaller than those above located in the Little Androscoggin River valley aquifer have been reported by Prescott (1967) and Prescott and Attig (1977). The wells, springs, and test holes also have a location number based on their latitude and longitude in degrees, minutes, and seconds and a two-digit sequence number. This number is used by the U.S. Geological Survey nationwide to distinguish each well from all others. For example, well AN 1071, which is located at 44°28 ! 23\" north latitude and 70°11'50\" west longitude, is given location designation 442823070115001. The \"01\" at the end of this designation is the two-digit sequence number assigned in the order in which wells within the specified latitude and longitude were recorded. GEOLOGY Bedrock Geology With the exception of the area north of Norway which is underlain by gneiss and schist, the bedrock in the Little Androscoggin River valley is predominantly granite (Hussey, 1979). Although all the bedrock is relatively impermeable compared to the overlying sand and gravel aquifer, the yield to drilled wells in the granite is usually adequate for household requirements. The altitude of the bedrock surface beneath the aquifer, shown on plate 2, was determined from seismic refraction profiling (table 11), logs of wells and test holes (table 12), and bedrock outcrops. The locations of seismic profiles and test holes are also shown on plate 2. The seismic investigations were done by the Survey in 1980 and 1981 and interpretation of field data was based on time-delay and ray-tracing techniques described by Scott and others (1972). The well and test hole data were obtained from MDEP, well drilling contractors, water utilities in Norway, Oxford, and South Paris, and from drilling done by the Survey for this study. Surficial Geology The unconsolidated deposits in the study area (plate 3) are the result of glaciations which occurred approximately 2,000,000 to 10,000 years ago, during the Pleistocene Epoch. Main

Ground-water resources of coastal citrus, hernando, and southwestern levy counties, florida

Abstract: Ground water in the coastal parts of Citrus, Hernando, and Levy Counties is obtained almost entirely from the Floridan aquifer. Water enters the aquifer as infiltration of precipitation or as ground-water flow from outside the area. Ground-water flow is toward the Gulf of Mexico in the limestone and dolomite of the Floridan aquifer, and natural discharge is through coastal springs and upward leakage in marshlands. The aquifer is composed of one or more of the following Tertiary formations in order of increasing age: the Suwannee Limestone, Ocala Limestone, Avon Park Limestone, and that part of the Lake City Limestone above the evaporites. The aquifer increases in thickness from about 700 feet in the north to about 1,000 feet in the south. The Floridan aquifer is unconfined near the coast. In inland areas, where sands and clays are present, the aquifer is semiconfined. Transmissivity of the Floridan aquifer was estimated to range from 20,000 feet squared per day in the northeast corner of the study area in Levy County, to 2,000,000 feet squared per day at several springs. Transmissivities are generally larger at springs and decrease radially away from them. The potentiometric surface of the aquifer changes very little between the wet and dry seasons. This small change is related to seasonal variations in rainfall. The potentiometric surface has changed little from 1965 to 1980 due to relatively little ground-wafer development. Chemical constituents increase in concentration toward the coast and with depth. Water quality is generally good except in areas adjacent to the coast where saltwater intrusion from the Gulf of Mexico poses a threat to the freshwater supply. Increased ground-water withdrawal associated with increased population and demand on water resources could lower the potentiometric surface, and seawater could move inland into the water supply. This threat can be lessened by placing well fields adequate distances from the saltwater-freshwater zone of transition so as not to reduce or reverse the hydraulic gradient adjacent to the coast.

Effects of sanitary sewers on ground-water levels and streams in Nassau and Suffolk Counties, New York; Part 1, geohydrology, modeling strategy, and regional evaluation

Abstract: From purpose and scope: This report is the first in a three-part series describing the U.S. Geological Survey's efforts in the detailed hydrologic investigation of southern Nassau and southwest Suffolk Counties, which includes a ground-water modeling study to predict the effects of an extensive sewer network scheduled to be completed in 1985. As the introduction to the series, this report has four objectives: (1) to present a detailed description of the hydrologic system in the area, including newly acquired hydrogeologic information; (2) to define the hydrogeologic factors that will be affected by the sewer network; (3) to explain the modeling strategy and describe the techniques used to develop the ground-water models of the two adjacent areas studied; and (4) to present a preliminary evaluation of the effects of sewers as predicted by a regional ground-water flow model.

Source, use, and disposition of water in Florida, 1980

Abstract: An average of 21,206 million gallons per day of water were withdrawn for use in Florida in 1980 a 6 percent increase since 1975 and a 38 percent increase of 5,893 million gallons per day since 1970. The 1980 daily total consisted of 7,309 million gallons of freshwater and 13,897 million gallons of saline water. The freshwater supply was almost equally divided between ground water (51 percent) and surface water (49 percent). Almost all the saline water was pumped from estuaries. Of the saline water, only 121 million gallons per day less than 1 percent was obtained from wells. The largest use of freshwater in Florida was for irrigation an average of 2,997 million gallons per day, about 5 percent more than in 1975. Other freshwater uses in 1980 were: 1,859 million gallons per day for thermoelectric power generation, (an increase of 9 percent since 1975); 1,361 million gallons per day for public supply, (an increase of 19 percent since 1975); 781 million gallons per day for industrial use other than thermoelectric power generation (a decrease of 17 percent since 1975); and 310 million gallons per day for rural self-supplied use (an increase of 17 percent since 1975). The peak month of freshwater use was May with 9,300 million gallons per day; September was the minimum month with 5,930 million gallons per day of freshwater use. Of the 13,897 million gallons per day of saline water used in 1980, nearly all was for thermoelectric power generation (an increase of 21 percent since 1975). Only 57.5 million gallons per day of saline water were used for all other industrial purposes. Industry was the only category that had a decline in water use, a decrease of 157 million gallons per day from 1975, or 17 percent, primarily because of recycling of water. The average per capita use of freshwater for all uses has shown a steady decline from 1,180 gallons per day in 1965 to 750 gallons per day in 1980. This is because population has increased at a greater rate than the demand for freshwater. Population increased about 68 percent in the past 15 years but the use of freshwater increased only about 7 percent. A decline in use of freshwater by industry has resulted because of recycling and the emphasis on the use of saline water for thermoelectric power generation. However, the per capita use of freshwater for public supplies and rural domestic use has shown a steady increase over the years since 1950, leveling off at about 170 gallons per day since 1975. Irrigation, the largest use of freshwater, is also responsible for the greatest consumptive use, 1,530 million gallons per day, which includes an estimated 18 million gallons per day from conveyance loss, or about 39 percent of the water pumped. The next largest use of freshwater, thermoelectric power production, had the smallest consumptive use, about 1.7 percent of use, or 32.8 million gallons per day.