SEARCH · USGS Science

Results for “Water”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources

USGS1984

Water levels and water-level changes in the Prairie du Chien-Jordan and Mount Simon-Hinckley aquifers, Twin Cities metropolitan area, Minnesota, 1971-80

The ground-water system in the Twin Cities Metropolitan Area includes five aquifers; two of these aquifers the Prairie du Chien-Jordan and the Mount Simon-Hinckley supply about 80 percent and 10 percent, respectively, of the ground water pumped for public supply. Water levels and changes in water levels in these two aquifers differ greatly in the Twin Cities Metropolitan Area. The Mississippi, Minnesota, and St. Croix Rivers are in hydraulic connection with and influence the pattern of flow in the upper aquifer, the Prairie du Chien-Jordan. Water generally flows toward these streams from water-level highs northeast, northwest, and south of Minneapolis and St. Paul. Consequently, heavy pumping has caused only localized cones of depression in the potentiometric surface of this aquifer. In contrast, the Mount Simon-Hinckley, which has only a slight hydraulic connection to the streams, is greatly influenced by pumping. Pumping in the urban centers of Minneapolis and St. Paul has caused a large cone of depression in the Mount Simon-Hinckley potentiometric surface. During 1971, the measurable cone was centered in eastcentral Hennepin County, was about 25 miles in diameter, and was as much as 150 feet deep at its center. Between 1971 and 1980, average water levels in the Prairie du Chien-Jordan aquifer changed less than 5 feet in most of the study area, but rose or declined as much as 25 feet locally in response to pumpage and recharge. During this period, seasonal declines of water levels from winter to summer lessened, and the area where these declines exceeded 10 feet decreased. In contrast, between 1971 and 1980, average water levels in the Mount Simon-Hinckley aquifer rose as much as 60 feet in the center of the cone of depression in response to decreased pumping. Also, the measurable cone of depression contracted from about 25 miles to about 15 miles in diameter. However, because of increased summer pumping due to below-average precipitation during 1980, seasonal water levels declined much more and over a wider area during 1980 than in 1971. Water-level data suggest that (1) little variation in annual pumpage between 1971 and 1980 from the Prairie du Chien-Jordan aquifer produced generally stable water levels in that aquifer, (2) decreased annual pumpage from the Mount Simon-Hinckley aquifer from 1971 to 1980 caused water levels in that aquifer to rise, and (3) a greater seasonal component of pumpage from the Mount Simon-Hinckley aquifer than from the Prairie du Chien-Jordan produced larger and more widespread seasonal water-level declines in the Mount Simon-Hinckley than in the Prairie du Chien-Jordan, particularly during dry years.

Minnesota↗

USGS1992

Hydrogeology, ground-water quality, and potential for water-supply contamination near the Shelby County landfill in Memphis, Tennessee

An investigation was conducted from 1989 to 1991 to collect and interpret hydrogeologic and ground-water-quality data specific to the Shelby County landfill in east Memphis, Tennessee. Eighteen wells were installed in the alluvial and Memphis aquifers at the landfill. Hydrogeologic data collected showed that the confining unit separating the alluvial aquifer from the Memphis aquifer was thin or absent just north of the landfill and elsewhere consists predominantly of fine sand and silt with lenses of clay. A water-table map of the landfill vicinity confirms the existence of a depression in the water table north and northeast of the landfill and indicates that ground water flows northeast from the Wolf River passing beneath the landfill toward the depression in the water table. A map of the potentiometric surface of the Memphis aquifer shows that water levels were anomalously high just north of the landfill, indicating downward leakage of water from the alluvial aquifer to the Memphis aquifer. An analysis of water-quality data for major and trace inorganic constituents and nutrients confirms that leachate from the landfill has migrated northeastward in the alluvial aquifer toward the depression in the water table and that contaminants in the alluvial aquifer have migrated downward into the Memphis aquifer. The leachate plume can be characterized by concentrations of certain major and trace inorganic constituents that are 2 to 20 times higher than samples from upgradient and background alluvial aquifer wells. The major and trace constituents that best characterize the leachate plume are total organic carbon, chloride, dissolved solids, iron, ammonia nitrogen, calcium, sodium, iodide, barium, strontium, boron, and cadmium. Several of these constituents (specifically dissolved solids, calcium, sodium, and possibly ammonia nitrogen, chloride, barium, and strontium) were detected in elevated concentrations in samples from certain Memphis aquifer wells. Elevated concentrations were detected in samples from the Memphis aquifer beneath the leachate plume where the confining unit is thin or absent. The distribution of halogenated alkanes (specifically dichlorodifluoromethane and trichlorofluoromethane) and halogenated alkenes (specifically 1,2-trans-dichloroethene and vinyl chloride) in samples from wells screened in both the alluvial and Memphis aquifers is similar to the distribution of major and trace inorganic constituents that characterize the leachate plume. The ground-water supply most susceptible to contamination from the Shelby County landfill is the Sheahan well field of the Memphis Light, Gas and Water Division. This well field is about 5 miles downgradient from the landfill in the direction of ground-water flow. Based on an estimated velocity of 0.5 to 1.5 feet per day, ground water would require about 50 to 150 years to travel from the Shelby County landfill to the Sheahan wellfield. Given the time and distance of transport, any contaminants in the ground water would not likely persistto reach this well field because of the effects of various physical, chemical, and biological processes, including dilution and adsorption.

Tennessee↗

USGS1994

Effects of water-control structures on hydrologic and water-quality characteristics in selected agricultural drainage canals in eastern North Carolina

November of water into and out of tidally affected canals in eastern North Carolina was documented before and after the installation of water-control structures. Water levels in five of the canals downstream from the water-control structures were controlled primarily by water-level fluctuations in estuarine receiving waters. Water-control structures also altered upstream water levels in all canals. Water levels were lowered upstream from tide gates, but increased upstream from flashboard risers. Both types of water-control structures attenuated the release of runoff following rainfall events, but in slightly different ways. Tide gates appeared to reduce peak discharge rates associated with rainfall, and flashboard risers lengthened the duration of runoff release. Tide gates had no apparent effect on pH, dissolved oxygen, suspended-sediment, or total phosphorus concentrations downstream from the structures. Specific conductance measured from composite samples collected with automatic samples increased downstream of tide gates after installation. Median concentrations of nitrite plus nitrate nitrogen were near the minimum detection level throughout the study; however, the number of observations of concentrations exceeding 0.1 milligram per liter dropped significantly after tide gates were installed. Following tide-gate installation, instantaneous loadings of nitrite plus nitrate nitrogen were significantly reduced at one test site, but this reduction was not observed at the other test site. Loadings of other nutrient species and suspended sediment did not change at the tide-gate test sites after tide-gate installation. Specific conductance was lower in the Beaufort County canals than in the Hyde County canals. Although there was a slight increase in median values at the flashboard-riser sites, the mean and maximum values declined substantially downstream from the risers following installation. This decline of specific conductance in the canals occurred despite a large increase of specific conductance in the tidal creek. Flashboard risers had no significant effect on concentrations of dissolved oxygen, suspended sediment, total ammonia plus organic nitrogen, or phosphorus. Maximum concentrations of ammonia nitrogen were smaller at both test sites after riser installation. In addition, concentrations of nitrite plus nitrate nitrogen exceeding 1.0 milligram per liter rarely occurred at the flashboard-riser test sites following installation of the risers. Median loadings of nitrite plus nitrate nitrogen and total nitrogen decreased at one riser test site following flashboard-riser installation. Tide gates and flashboard risers were associated with reductions in concentrations and export of nitrite plus nitrate nitrogen; however, these changes should be interpreted cautiously because reductions were not observed consistently at every site. The hydrology and baseline water-quality characteristics of the two study areas differ, making comparisons of the effectiveness of the two types of water-control structures difficult to interpret. The effects of water-control structures on the hydrology of the drainage canals are more meaningful than the changes in water quality. Tide gates and flashboard risers altered the hydrologic characteristics of the drainage canals and created an environment favorable for nutrient loss or transformation. Both structures retained agricultural drainage upstream, which increased potential storage for infiltration and reduced the potential for surface runoff, sediment, and nutrient transport, and higher peak outflow rates.

North Carolina↗

USGS1999

Induced infiltration from the Rockaway River and water chemistry in a stratified-drift aquifer at Dover, New Jersey, with a section on modeling ground-water flow in the Rockaway River Valley

The vertical hydraulic conductivity per unit thickness (streambed leakance) of unconsolidated sediment immediately beneath the channel of the Rockaway River near a municipal well field at Dover, N.J., is between 0.2 and 0.6 feet per day per foot and is probably near the low end of this range. This estimate is based on evaluation of three lines of evidence: (1) Streamflow measurements, which indicated that induced infiltration of river water near the well field averaged 0.67 cubic feet per second; (2) measurements of the rate of downward propagation of diurnal fluctuations in dissolved oxygen and water temperature at three piezometers, which indicated vertical Darcian flow velocities of 0.6 and 1.5 feet per day, respectively; and (3) chemical mixing models based on stable isotopes of oxygen and hydrogen, which indicated that 30 percent of the water reaching a well near the center of the well field was derived from the river. The estimated streambed-leakance values are compatible with other aquifer properties and with hydraulic stresses observed over a 2-year period, as demonstrated by a set of six alternative groundwater flow models of the Rockaway River valley. Simulated water levels rose 0.5 to 1.7 feet near the well field when simulated streambed leakance was changed from 0.2 to 0.6 feet per day per foot, or when a former reach of the Rockaway River valley that is now blocked by glacial drift was simulated as containing a continuous sand aquifer (rather than impermeable till). Model recalibration to observed water levels could accommodate either of these changes, however, by plausible adjustments in hydraulic conductivity of 35 percent or less. The ground-water flow models incorporate a new procedure for simulating areal recharge, in which water available for recharge in any time interval is accepted as recharge only where the water level in the uppermost model layer is below land surface. Water rejected as recharge on upland hillsides is allowed to recharge aquifers at the base of the hillsides. Inclusion of uplands in models of valley-fill aquifers and use of the new procedure increases model complexity and data requirements, but automates the simulation of recharge to those aquifers from the uplands, even in transient-state simulations with multiple periods of varied stresses, and facilitates delineation of upland areas that contribute water to well fields. The area from which ground water flowed toward the Dover well field decreased with an increase in simulated streambed leakance or an increase in simulated hydraulic conductivity of upland till. Concentrations of solutes in ground water near the Dover well field reflect the mixing of native ground water with water infiltrated from the Rockaway River. Chemical reactions in the aquifer, chiefly the weathering of carbonate minerals by dissolved carbon dioxide, affect the pH and the concentrations of both solutes and dissolved gases. Concentrations of sodium, chloride, and sulfate appear to be related to man's activities, such as road deicing, or to decay of organic matter in the aquifer.

New Jersey↗

USGS1996

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas: Shallow ground-water quality of a land-use area in the San Luis Valley, south-central Colorado, 1993

This report describes the quality of shallow ground water in an agricultural area in the San Luis Valley, Colorado, and discusses how natural and human factors affect the quality of shallow ground water. Thirty-five wells were installed, and water samples were collected from these wells and analyzed for selected dissolved common constituents, nutrients, trace elements, radionuclides, and synthetic organic compounds. The San Luis Valley is a high intermontane valley that is partially drained by the Rio Grande. The San Luis Valley land-use study area was limited to a part of the valley where the depth to water is generally less than 25 feet. The area where the 35 monitor wells were installed was further limited to the part of the study area where center-pivot overhead sprinklers are used to irrigate crops. Precipitation, runoff from adjacent mountainous areas, and ground-water inflow from the adjacent mountainous areas are the main sources of water to the aquifers in the San Luis Valley. Discharge of water from the shallow, unconfined aquifer in the valley is mainly from evapotranspiration. The dominant land use in the San Luis Valley is agriculture, although nonirrigated land and residential land are interspersed with agricultural land. Alfalfa, native hay, barley, wheat, potatoes, and other vegetables are the main crops. Dissolved-solids concentrations in shallow ground water sampled ranged from 75 to 1,960 milligrams per liter. The largest median concentration of cations was for calcium, and the largest median concentration of anions was for bicarbonate in shallow ground water in the San Luis Valley. Calcium concentrations ranged from 7.5 to 300 milligrams per liter, and bicarbonate concentrations ranged from 28 to 451 milligrams per liter. Nitrite plus nitrate concentrations ranged from less than 0.1 to 58 milligrams per liter as N; water from 11 wells had nitrite plus nitrate concentrations greater than 10 milligrams per liter as N. With the exception of the following trace elements--aluminum, barium, iron, manganese, molybdenum, and uranium--the concentrations of trace elements were less than 10 micrograms per liter in 90 percent of the samples. All trace-element concentrations measured were below the maximum contaminant levels set by the U.S. Environmental Protection Agency. Five samples exceeded the proposed maximum contaminant level of 0.02 milligram per liter for uranium. All samples collected exceeded the proposed maximum contaminant level for radon-222. The volatile organic compound methyltertbutylether was detected in one sample at a concentration of 0.6 microgram per liter. Of the pesticides analyzed for, one or more were detected in water from 5 of the 35 wells sampled. Metribuzin was the most commonly detected pesticide and was detected in water from three wells at concentrations ranging from an estimated 0.005 to 0.017 microgram per liter. Metolachlor (detected in one sample at a concentration of 0.072 microgram per liter), prometon (detected in one sample at a concentration of 0.01 microgram per liter), and p,p'-DDE (detected in one sample at an estimated concentration of 0.002 microgram per liter) were the other pesticides detected. The U.S. Environmental Protection Agency lifetime health advisory for metolachlor, metribuzin, and prometon is 100 micrograms per liter, which is much larger than the concentrations measured in the shallow ground water sampled for this study. The elevated nitrite plus nitrate concentrations in shallow ground water are indicative of leaching of fertilizers from the land surface. This conclusion is consistent with conclusions made in other investigations of the San Luis Valley.

Colorado↗

USGS1955

Reconnaissance of geology and ground water in the lower Grand River valley, South Dakota, with a section on Chemical quality of the ground water

The area described in this report is the flood plain of the Grand River and the bordering benchlands in Perkins and Corson Counties, S. Dak., from a point about 6 miles west of the town of Shadehill to the confluence of the Grand and Missouri Rivers near Mobridge. The exposed bedrock formations include the Pierre shale, the Fox Hills sandstone, and the Hell Creek formation of Late Cretaceous age, and-the Ludlow member of the Fort Union formation of Tertiary (Paleocene) age. Some stringers of the Cannonball formation probably interfinger with beds of the Ludlow member but none of the former was identified during the field investigations. The Pierre shale is exposed from the mouth of the Grand River to approximately the center of the area. Although a few wells in the area obtain water from this formation, it is not generally considered to be a source of supply. The Fox Hills sandstone, the Hell Creek formation, and the Ludlow member of the Fort Union formation are exposed successively upstream and, where saturated, yield small to moderate quantities of water to wells. Unconsolidated deposits of silt, sand, and gravel occur in several physiographic positions; they underlie the high benchland on both sides of the river, the poorly defined terraces along the river, and the flood plain throughout its entire length. Possibly all these unconsolidated deposits are water bearing; however, where the deposits on the benchland and in the terraces are dissected by streams, they probably contain little or no water. The average depth to ground water along the lower Grand River valley is about 17 feet. Probably, the flow of ground water in the bottom lands is nearly parallel to and slightly toward the surface stream. The measurements of the water level in observation wells for the period 1946-48 indicate that the fluctuations of the water table are small. The results of analyses of 13 samples of ground water from the alluvium and the Hell Creek formation show that the suitability of the ground water for use varies because of the considerable range in mineralization and composition. Dissolved solids ranged from 343 to 4,250 parts per million (ppm), hardness from 11 to 1,130 ppm, and percentage of sodium from 25 to 98. Concentrations of some of the individual constituents exceed standards of the United States Public Health Service. The water is moderately hard and contains undesirable amounts of iron and moderate to large amounts of dissolved solids. In general, the water quality ranges from excellent to unsuitable for irrigation use. The result of the mixing of the ground water with recharge water from Shadehill Reservoir cannot be predicted on the basis of available data. The geologic and hydrologic data in this report were obtained from earlier reports and from field observations during the period 1946-48. The report includes a geologic map and tabulated well records.

South Dakota↗

USGS1965

Ground-water pumpage and water-level changes in the Milwaukee-Waukesha area, Wisconsin, 1950-61

Artesian water pressure in the deep sandstone aquifer continued to decline throughout most of the Milwaukee-Waukesha area, Wisconsin between 1950 and 1961. Areas of greatest water-level decline were in northeast Waukesha County and in northwest Milwaukee County. The chief cause of the decline was continued heavy pumpage. The major aquifers of southeastern Wisconsin are the Niagara aquifer, which is primarily Niagara Dolomite of Silurian age, and the sandstone aquifer, which consists of sandstones of Cambrian and Ordovician ages. Locally, the glacial sands and gravels ,of Pleistocene age also are important aquifers. In the Milwaukee-Waukesha area, the sandstone aquifer is completely artesian, confined above by the Maquoketa Shale. The Niagara aquifer is generally unconfined. Pumpage from the sandstone aquifer in the Milwaukee-Waukesha area de- creased from about 23.3 million gallons per day in 1950 to about 20.9 million gallons per day in 1961. The principal reason for decreased pumpage was sub- stitution of surface-water supply from Lake Michigan. Between 1950 and 1961, the water-level changes in wells in the sandstone aquifer ranged from plus 10 feet at Town of Lake to minus 98 feet in northwest Milwaukee. Except for a small area near Town of Lake, water levels in wells in the Milwaukee-Waukesha area were lower in 1961 than in 1950. Water-level changes were directly related to the pumpage pattern and pump- age changes. Increased pumpage at Waukesha and in northwest Milwaukee and continued heavy pumpage at Wauwatosa caused widespread water-level declines in northeast Waukesha County and in northwest Milwaukee County. Locally, decreased pumpage at West Milwaukee allowed limited recovery of water levels since 1957. Estimates of pumpage through the year 1975 indicate a pumpage decrease in the middle 1960's, followed by an increase in the late 1960's and early 1970's. Additional conversion to surface-water supply in Milwaukee County will account for most pumpage decreases. Increased pumpage is most likely in Waukesha County where the population is expanding rapidly and an adequate surface-water supply is not readily accessible. The westward shift of the pumpage pattern may cause an additional water-level decline of about 50 feet at Waukesha but will permit water levels to recover about 100 feet at West Allis by 1975. Partial or complete conversion to surface-water supplies by municipalities that depend entirely on water from the sandstone aquifer would allow greater use of the sandstone aquifer by isolated suburban developments and industries.

Wisconsin↗

USGS1969

Relation of sea water to fresh water in carbonate rocks in coastal areas, with special reference to Florida, U.S.A., and Cephalonia (Kephallinia), Greece

The principles controlling the equilibrium between the denser salty water and the lighter fresh water in coastal aquifers apply to carbonate as well as sand systems. However, under certain equilibrium conditions of fresh and salt water in parts of some carbonate aquifers unusual hydrologic phenomena result. Hydrologic conditions at Tarpon Springs, Florida, and Cephalonia, Greece, include deep vertical openings as sinkholes through a relatively impervious part of the aquifer system. In both cases the tops of the sinkholes or natural wells are exposed to sea water. At Tarpon Springs the dynamic equilibrium between salt water and fresh water fluctuates so that the flow of salt water from the spring to a lake 2 miles away is sometimes reversed. At Cephalonia, the head of fresh water does not exceed the head of salty water in the sinkholes; the flow of sea water into the aquifer, aided by a shallow channel from the sea, is continuous, and the water level in the sinkhole is continuously depressed below sea level. Both cases represent a partially confined U-tube system where water at the seaward, sinkhole end is denser than at the other end and where a low fresh-water head is less than the salt-water head.

Cephalonia, Florida↗

USGS1999

Dissolved sulfide distributions in the water column and sediment pore waters of the Santa Barbara Basin

Dissolved sulfide concentrations in the water column and in sediment pore waters were measured by square-wave voltammetry (nanomolar detection limit) during three cruises to the Santa Barbara Basin in February 1995, November–December 1995, and April 1997. In the water column, sulfide concentrations measured outside the basin averaged 3 ± 1 nM ( n = 28) in the 0 to 600 m depth range. Inside the basin, dissolved sulfides increased to reach values of up to 15 nM at depths >400 m. A suite of box cores and multicores collected at four sites along the northeastern flank of the basin showed considerable range in surficial (<0.5 cm) pore-water sulfide concentrations: <0.008, 0.01, 0.02, to as much as 0.4 μM at the 340, 430, 550, and 590 m sites, respectively. At a core depth of 10 cm, however, pore–water sulfides exhibited an even wider range: 0.005, 0.05, 0.1, and 100 μM at the same sites, respectively. The sulfide flux into the deep basin, estimated from water-column profiles during three cruises, suggests a fairly consistent input of 100–300 nmole m −2 h −1 . In contrast, sulfide fluxes estimated from pore-water sulfide gradients at the sediment water interface were much more variable (−4 to 13,000 nmole m −2 h −1 ). Dissolved silicate profiles show clear indications of irrigation at shallow sites (340 and 430 m) in comparison to deeper basin sites (550 and 590 m) with low (<10 μM) bottom-water dissolved-oxygen concentrations. Pore-water profiles indicate ammonia generation at all sites, but particularly at the deep-basin 590 m site with concentrations increasing with sediment depth to >400 μM at 10 cm. Decreases in water-column nitrate below the sill depth indicate nitrate consumption (−55 to −137 μmole m −2 h −1 ) similar to nearby Santa Monica Basin. Peaks in pore-water iron concentrations were generally observed between 2 and 5 cm depth with shallowest peaks at the 590 m site. These observations, including observations of the benthic microfauna, suggest that the extent to which the sulfide flux, sustained by elevated pore-water concentrations, reaches the water column may be modulated by the abundance of sulfide-oxidizing bacteria in addition to iron redox and precipitation reactions.

Geochimica et Cosmochimica Acta↗

USGS1999

Water-use patterns of woody species in pineland and hammock communities of South Florida

Rockland pine forests of south Florida dominated by Pinus elliottii var. densa characteristically have poor soil development in relation to neighboring hardwood hammocks. This has led to the hypothesis that Everglades hammock trees are more reliant on soil moisture derived from local precipitation whereas pineland plants must depend more on groundwater linked to broader regional hydrologic patterns. Because soil moisture sources are likely to vary more than groundwater sources, we hypothesized that hammock plants would exhibit correspondingly higher levels of dry season water stress. This was examined by measuring predawn water potentials, and by analyzing water uptake in representative hammock and pineland woody species using stable isotopes of plant water and that of potential sources during wet and dry seasons. Two species typical of each of the two communities were selected; a fifth species which was found in both communities, Lysiloma latisiliqua Benth., was also analyzed. Water content of soils in both communities decreased from wet to dry season. Consistent with our hypothesis, the change in predawn water potentials between the wet and dry season was less in pineland species than that of hammock species. Water potential changes in L. latisiliqua in both communities resembled that of hammock species more than pineland plants. Isotopic data showed that pineland species rely proportionately more on groundwater than hammock species. Nevertheless, unlike hammock species in the Florida Keys, mainland hammock species utilized a substantial amount of groundwater during the dry season.

Florida↗

USGS2018

Evaluating and managing environmental water regimes in a water-scarce and uncertain future

While the number of environmental flows and water science programmes continues to grow across the globe, there remains a critical need to better balance water availability in support of human and ecological needs and to recognise the environment as a legitimate user of water. In water‐stressed areas, this recognition has resulted in friction between water users in the public and private sectors. An opportunity exists for practitioners to be on the forefront of the science determining best practices for supporting environmental water regimes. This Special Issue brings together a collection of environmental flows science and water management papers organised around three major themes: (1) method development and testing; (2) application case studies; and (3) efficacy evaluation. Contents of this Special Issue are intended to foster collaboration and broaden transferability of the information, technical tools, models and methods needed to support environmental water management programmes. The technical sophistication of methods and modelling tools, while important to the advancement of environmental water science, may come at the expense of easily interpretable outcomes that positively influence management decisions. Researchers need to be more proactive in translating the results of advanced modelling methodologies into user‐friendly tools and methods. This will allow stakeholders and water managers to proactively test alternative water allocation scenarios to help address growing human water demands in the face of droughts and changes in climatic patterns. The application of environmental flows science and water management strategies cannot be done in isolation. Implementation involves a complex decision‐making process that integrates ecological, hydrologic and social science across diverse multifaceted governance systems and requires active stakeholder involvement. Scientists and managers must strengthen partnerships at multiple scales to develop sensible science investment strategies so that collective knowledge can be translated into wise environmental water management decisions.

Freshwater Biology↗

USGS2005

Estimating water‐table altitudes for regional ground‐water flow modeling, U.S. Gulf Coast

Water‐table altitude, a controlling factor for ground‐ water flow , was estimated from detailed topographic data by subtracting the estimated depth‐to‐water. Land‐surface altitude of the Coastal Plain in the south‐ central United States varies from 0 to more than 800 feet above sea level. Predevelopment depth‐to‐water in 6,825 wells less than 150 feet deep averages 25.7 feet (standard deviation, 19.5 feet). Most water‐table‐altitude variation is due to variation in land‐surface altitude and not due to variation in depth‐to‐ water. Digital topographic data, from 1:250,000 scale maps for every 30 seconds of latitude and longitude are available for the continental United States. About 90 altitudes were averaged for each 25‐square‐mile block of a rectangular grid used for ground‐water flow modeling. Multiple linear regressions of predevelopment water‐level data and topographic data were used to derive empirical equations relating water‐table altitude to topography. The regression method was more consistent, efficient, and accurate than manually digitizing values from manually contoured water‐table maps. Water‐table maps usually are prepared from few data that are concentrated in topographically flat areas. Manually digitizing water‐table maps on a regional scale introduces additional error. About 35 percent of the water‐table altitudes obtained manually were greater than average land‐surface altitudes from topographic data. The mean difference between water‐table altitudes from the two methods was less than 10 feet, which indicates no systematic error was incorporated in the regression method. Copyright © 1989, Wiley Blackwell. All rights reserved

Gulf of Mexico coast↗

USGS2008

Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms

Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin, which is given to lactating cows as a feed. By weight, monensin can be the most significant antibiotic used in a dairy farm. This study investigates the potential of monensin to move from dairy operations into the surrounding ground water. Using two dairy farms in California as study sites, we twice collected samples along the environmental pathway-from flush lanes, lagoon waters, and shallow ground water beneath the dairies and beneath its associated manured fields. Monensin concentrations were determined using solid-phase extraction and liquid chromatography-tandem mass spectrometry with positive electrospray ionization. Monensin was detected in all of the flush lane and lagoon water samples. Theoretical maximum concentration estimated from the actual dosing rate and the theoretical excretion rate assuming no attenuation was one order of magnitude greater than observed concentrations, suggesting significant attenuation in the manure collection and storage system. Monensin was also detected, at levels ranging from 0.04 to 0.39 microg L(-1), in some of the ground water samples underneath the production area of the dairy but not from the adjacent manured fields. Concentrations in ground water immediately downgradient of the lagoons were one to two orders of magnitude lower than the concentrations detected in lagoons, suggesting attenuation in the subsurface. The data suggest the possibility of monensin transport into shallow (2-5 m) alluvial ground water from dairy management units, including manure storage lagoons and freestalls occupied by heifers, lactating cows, and dry cows.

Journal of Environmental Quality↗

USGS1951

Water law, with special reference to ground water

This report was prepared in July 1950 at the request of the President's Water Resources Policy Commission. It followed the report entitled Water facts in relation to a national water-resources policy," which, in part, has been published as Geological Survey Circular 114 under the title "The water situation in the United States, with special reference to ground water.'' The only changes made in preparing this report for publication as a circular were revision of the sections on Idaho, Indiana, Massachusetts, Montana, New Mexico, Oregon, and Texas, to bring them up to date. This report discusses some of the problems in the field of water law and summarizes briefly the laws providing for the acquiring, of water rights in the different States. The need for consideration of the subject is brought out in Circular 114. In that report it was pointed out that: (1) The use of water in the United States is increasing rapidly and undoubtedly will continue to do so; (2) ground water must meet a large and perhaps an increasing share of our water demands; (3) the full development of the water resources of ever more numerous and larger areas will require manipulation of stream systems and ground-water reservoirs to protect them from overdevelopment or pollution and to increase and maintain their yield of water of good quality; and (4) such manipulation, as well as the protection of existing rights, requires control of water use by means of hydrologically sound statutes.

Circular↗

USGS1951

Ground-water conditions in the Dutch Flats area, Scotts Bluff and Sioux Counties, Nebraska, with a section on chemical quality of the ground water

The U.S. Department of the Interior (DOI) studied contamination induced by irrigation drainage in 26 areas of the Western United States during 1986-95. Comprehensive compilation, synthesis, and evaluation of the data resulting from these studies were initiated by DOI in 1992. Soils and ground water in irrigated areas of the West can contain high concentrations of selenium because of (1) residual selenium from the soil's parent rock beneath irrigated land; (2) selenium derived from rocks in mountains upland from irrigated land by erosion and transport along local drainages, and (3) selenium brought into the area in surface water imported for irrigation. Application of irrigation water to seleniferous soils can dissolve and mobilize selenium and create hydraulic gradients that cause the discharge of seleniferous ground water into irrigation drains. Given a source of selenium, the magnitude of selenium contamination in drainage-affected aquatic ecosystems is strongly related to the aridity of the area and the presence of terminal lakes and ponds. Marine sedimentary rocks and deposits of Late Cretaceous or Tertiary age are generally seleniferous in the Western United States. Depending on their origin and history, some Tertiary continental sedimentary deposits also are seleniferous. Irrigation of areas associated with these rocks and deposits can result in concentrations of selenium in water that exceed criteria for the protection of freshwater aquatic life. Geologic and climatic data for the Western United States were evaluated and incorporated into a geographic information system (GIS) to produce a map identifying areas susceptible to irrigation-induced selenium contamination. Land is considered susceptible where a geologic source of selenium is in or near the area and where the evaporation rate is more than 2.5 times the precipitation rate. In the Western United States, about 160,000 square miles of land, which includes about 4,100 square miles (2.6 million acres) of land irrigated for agriculture, has been identified as being susceptible. Biological data were used to evaluate the reliability of the map. In 12 of DOI's 26 study areas, concentrations of selenium measured in bird eggs were elevated sufficiently to significantly reduce hatchability of the eggs. The GIS map identifies 9 of those 12 areas. Deformed bird embryos having classic symptoms of selenium toxicosis were found in four of the study areas, and the map identifies all four as susceptible to irrigation-induced selenium contamination. The report describes the geography, geology, and ground-water resources of the Dutch Flats area in Scotts Bluff and Sioux Counties, Nebr. The area comprises about 60 square miles and consists predominantly of relatively flat-lying terraces. Farming is the principal occupation in the area. The farm lands are irrigated largely from surface water; ground water is used only as a supplementary supply during drought periods. The climate in the area is semiarid, and the mean annual precipitation is about 16 inches. The rocks exposed in the Dutch Flats area are of Tertiary sad Quaternary age. A map showing the areas of outcrop of the rock formations is included in the report. Sufficient unconfined ground water for irrigation supplies is contained in the deposits of the .third terrace, and wells that yield 1,000 to 2,000 gallons a minute probably could be developed. The depth to water in the area ranges from a few feet to about 80 feet sad averages about 30 feet. The depth to water varies throughout the year; it is least in the late summer when the recharge from irrigation is greatest, sad it is greatest in the early spring before irrigation is begun. A map showing the depth to water in September 1949 is included in the report. The ground-water reservoir is recharged by seepage from irrigation canals and laterals, by seepage from irrigation water applied to the farms, and, to a much lesser extent, by precipitation. In the area b

Nebraska↗

USGS2024

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2020

As part of a long-term cooperative program to monitor water quality within the Scituate Reservoir drainage area, the U.S. Geological Survey in cooperation with Providence Water (sometimes known as Providence Water Supply Board) collected streamflow and water-quality data in tributaries to the Scituate Reservoir, Rhode Island. Streamflow and concentrations of chloride and sodium estimated from records of specific conductance for 14 tributaries were used to calculate loads of chloride and sodium during water year 2020 (October 1, 2019, through September 30, 2020). Water-quality samples were collected by Providence Water at 37 sampling stations on tributaries to the Scituate Reservoir during water year 2020. These water-quality data are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields of selected water-quality constituents for water year 2020 in this report. Annual mean streamflows for monitoring stations in this study ranged from about 0.32 to 26.7 cubic feet per second during water year 2020. At the 14 continuous-record streamgages, tributaries transported about 2,200 metric tons of chloride and 1,400 metric tons of sodium to the Scituate Reservoir; annual chloride yields for the tributaries ranged from 13 to 110 metric tons per square mile, and annual sodium yields ranged from 8.8 to 6 metric tons per square mile. At the stations where water-quality samples were collected by Providence Water, the medians of the median daily loads were 220 kilograms chloride per day, 10 grams nitrite as nitrogen per day, 500 grams nitrate as nitrogen per day, 290 grams orthophosphate as phosphate per day, 55,000 million colony forming units of coliform bacteria per day, and less than 900 million colony forming units of Escherichia coli per day. The medians of the median yields were 76 kilograms chloride per day per square mile, 4.1 grams nitrite as nitrogen per day per square mile, 240 grams nitrate as nitrogen per day per square mile, 100 grams orthophosphate as phosphate per day per square mile, 31,000 million colony forming units of coliform bacteria per day per square mile, and less than 260 million colony forming units of Escherichia coli per day per square mile.

Rhode Island↗

USGS2024

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2021

As part of a long-term cooperative program to monitor water quality within the Scituate Reservoir drainage area, the U.S. Geological Survey in cooperation with Providence Water (formerly Providence Water Supply Board) collected streamflow and water-quality data in tributaries to the Scituate Reservoir, Rhode Island. Streamflow and concentrations of chloride and sodium estimated from records of specific conductance for 16 tributaries were used to calculate loads of chloride and sodium during water year 2021 (October 1, 2020, through September 30, 2021). Water-quality samples were collected by Providence Water at 36 sampling stations on tributaries to the Scituate Reservoir during water year 2021. These water-quality data are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields of selected water-quality constituents for water year 2021. Annual mean streamflows for monitoring stations in this study ranged from 0.37 to 32.4 cubic feet per second during water year 2021. At the 16 continuous-record streamgages, tributaries transported about 2,900 metric tons (t) of chloride and 1,800 t of sodium to the Scituate Reservoir; annual chloride yields for the tributaries ranged from 15 to 110 metric tons per square mile (t/mi 2 ), and annual sodium yields ranged from 10 to 68 t/mi 2 . At the stations where water-quality samples were collected by Providence Water, the medians of the median daily loads were 180 kilograms per day for chloride, 12 grams per day as nitrogen for nitrite, less than 700 grams per day as nitrogen for nitrate, 410 grams per day as orthophosphate for phosphate, 71,000 million colony forming units per day for coliform bacteria, and less than 2,000 million colony forming units per day for Escherichia coli . The medians of the median yields were 67 kilograms per day per square mile for chloride, 4.2 grams per day per square mile as nitrogen for nitrite, 400 grams per day per square mile as nitrogen for nitrate, 180 grams per day per square mile as orthophosphate as phosphate, 46,000 million colony forming units per day per square mile for coliform bacteria, and 1,000 million colony forming units per day per square mile for Escherichia coli .

Rhode Island↗

USGS2025

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2022

As part of a long-term cooperative program to monitor water quality within the Scituate Reservoir drainage area, the U.S. Geological Survey, in cooperation with Providence Water (formerly the Providence Water Supply Board), collected streamflow and water-quality data in tributaries to the Scituate Reservoir, Rhode Island. Streamflow and concentrations of chloride and sodium estimated from records of specific conductance for 16 tributaries were used to calculate loads of chloride and sodium during water year 2022 (October 1, 2021, through September 30, 2022). Water-quality samples were collected by Providence Water at 37 sampling stations on tributaries to the Scituate Reservoir during water year 2022. These water-quality data are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields of selected water-quality constituents for water year 2022. Annual mean streamflows for monitoring stations in this study ranged from about 0.31 to 28.0 cubic feet per second during water year 2022. At the 16 continuous-record streamgages, tributaries transported about 2,600 metric tons of chloride and 1,600 metric tons of sodium to the Scituate Reservoir; annual chloride yields for the tributaries ranged from 15 to 100 metric tons per square mile, and annual sodium yields ranged from 10 to 59 metric tons per square mile. At the stations where water-quality samples were collected by Providence Water, the medians of the median daily loads were 55,000 million colony forming units per day for coliform bacteria, 1,300 million colony forming units per day for Escherichia coli , 230 kilograms per day for chloride, 11 grams per day as nitrogen for nitrite, 620 grams per day as nitrogen for nitrate, and 440 grams per day as orthophosphate for phosphate, The medians of the median yields were 25,000 million colony forming units per day per square mile for coliform bacteria, 810 million colony forming units per day per square mile for Escherichia coli , 110 kilograms per day per square mile for chloride, 5.1 grams per day per square mile as nitrogen for nitrite, less than 300 grams per day per square mile as nitrogen for nitrate, and 230 grams per day per square mile as orthophosphate for phosphate.

Rhode Island↗