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At least 1,315 records · Page 73Linked to original sources
USGS1998

Base cation concentrations in subsurface flow from a forested hillslope: The role of flushing frequency

A 20-m-wide trench was excavated to bedrock on a hillslope at the Panola Mountain Research Watershed in the Piedmont region of Georgia to determine the effect of upslope drainage area from the soil and bedrock surfaces on the geochemical evolution of base cation concentrations in subsurface flow. Samples were collected from ten 2-m sections and five natural soil pipes during three winter rainstorms in 1996. Base cation concentrations in hillslope subsurface flow were generally highest early and late in the storm response when flow rates were low, but during peak flow, concentrations varied little. Base cation concentrations in matrix flow from the 10 trench sections were unrelated to the soil surface drainage area and weakly inversely related to the bedrock surface drainage area. Base cation concentrations in pipe flow were lower than those in matrix flow and were also consistent with the inverse relation to bedrock surface drainage area found in matrix flow. The left side of the trench, which has the highest bedrock surface drainage area, had consistently lower mean base cation concentrations than the right side of the trench, which has the lowest bedrock surface drainage area. During moderate size rain events of about 20–40 mm, subsurface flow occurred only on the left side of the trench. The greater volume of water that has flowed through the left side of the trench appears to have resulted in greater leaching of base cations from soils and therefore lower base cation concentrations in subsurface flow than in flow from the right side of the trench. Alternatively, a greater proportion of flow that bypasses the soil matrix may have occurred through the hillslope on the left side of the trench than on the right side. Flushing frequency links spatial hillslope water flux with the evolution of groundwater and soil chemistry.

Georgia↗
USGS1987

Role of pressure in smectite dehydration: Effects on geopressure and smectite-to-illite transformation

Evaluation of the effect of pressure on the temperature of interlayer water loss (dehydration) by smectites under diagenetic conditions indicates that smectites are stable as hydrated phases in the deep subsurface. Hydraulic and differential pressure conditions affect dehydration differently. Smectites under hydraulic pressure conditions, such as in the pores of a sandstone, will retain at least two water layers (basal spacing, d 001 = 15A). Smectites under differential pressure for vertical effective stress conditions, such as in compacting shales, are stable as two-water-layer complexes to temperatures of 67°-81°C (153°-178°F), at which one water layer will be expelled. Loss of the remaining water layer requires temperatures of 172°-19 °C (342°-377°F). The temperatures of dehydration increase with pore fluid pressure and interlayer water density. The stability of hydrated smectite under hydraulic-pressure conditions indicates that simple thermal dehydration of smectite is not important in the development of abnormally high subsurface fluid pressures. Loss of water by smectite in a shale of low permeability may cause overpressuring; however, the resulting increase in fluid pressure will inhibit further dehydration. The temperatures of dehydration under differential-pressure conditions are inversely related to pressure and interlayer water density. The temperature range for interlayer water loss by smectite under differential-pressure conditions is approximately coincident with the beginning of the smectite-to-illite transformation and hydrocarbon generation. The model presented assumes the effects of pore fluid composition and 2:1 layer reactivity to be negligible. Agreement between theoretical and experimental results validate this assumption. However, changes in the chemical stability of the 2:1 layer with decreasing interlayer water content, increasing pressure and temperature, and changing pore-fluid chemistry may be important in initiating clay and organic matter transformations. Changes in clay stability with interlayer water loss may also be responsible for the different rates of smectite-to-illite transformation observed in interbedded sandstones and shales.

American Association of Petroleum Geologists Bulle↗
USGS2025

A comprehensive assessment of membrane bioreactor contaminant removal efficacy through analytical chemistry, fish exposures, and microbiome characterization

Treated municipal wastewater effluent is an important pathway for Contaminants of Emerging Concern (CEC) to enter aquatic ecosystems. As the aging wastewater infrastructure in many industrialized countries requires upgrades or replacement, assessing new treatment technologies in the context of CEC effects may provide additional support for science-based resource management. Here, we used three lines of evidence, analytical chemistry, fish exposure experiments, and fish and water microbiome analysis, to assess the effectiveness of membrane bioreactor treatment (MBR) to replace traditional activated sludge treatment. To do this, we sampled a municipal wastewater treatment plant with a split wastewater stream, a portion of which was treated with an MBR and another via an oxidation ditch (OXI). The OXI and MBR treatments substantially reduced most measured CECs compared to the primary effluent (PRI). Only pesticides and some pharmaceuticals were recalcitrant to both secondary treatment methods. While ammonia toxicity of PRI prevented its inclusion in fish exposure experiments, exposure of fish with waters from the OXI or MBR treated wastewater produced only subtle biological differences with no adverse apical outcomes. These findings were consistent with low chemically derived exposure: activity ratios for OXI and MBR. Microbiome analysis of fish and wastewater highlighted the significant reduction of microbial abundance and diversity in the MBR treatment compared to all other treatments. The comparable removal efficacy of CECs in MBR makes it an attractive alternative to traditional OXI, especially when MBR may eliminate the need for tertiary treatment for wastewater disinfection.

Environmental Toxicology and Chemistry↗
USGS2001

Surface-water and ground-water quality in the Yucaipa area, San Bernardino and Riverside Counties, California, 1996-98

The quality of surface water and ground water in the Yucaipa area was evaluated to determine general chemical characteristics and to identify areas of recent ground-water recharge. Water samples, collected from 8 sites on 3 creeks and from 25 wells, were analyzed for general chemistry, nutrients, tritium, and stable isotopes of hydrogen and oxygen. At one production well (1S/2W-25R4), water samples were collected at discrete depths during pumping and a continuous profile of the vertical flow rate inside the well casing was recorded. In addition to general-chemistry samples, tritium and carbon-14 samples were collected at this well to interpret the age of water at different depths.Results indicate that most water in the Yucaipa area is a calcium-bicarbonate type. The general chemical composition of surface water resembles that of ground water, although the concentration of most constituents is higher in ground water. The chemical composition of most ground-water samples is similar. Elevated concentrations of nitrate in some ground-water samples may indicate recharge from agricultural areas.In surface water that recharges ground water tritium activity ranged from 7 to 18 picocuries per liter. The range of tritium activity found in ground water indicates different times since recharge and possible mixing along ground-water flow paths. The oldest ground-water sample had a tritium activity less than 0.3 picocuries per liter, indicating more than 50 years since recharge. Water samples that had tritium activity greater than 0.3 picocuries per liter indicate that some of the water was recharged since 1952. The youngest ground water (greater than 7 picocuries per liter) was found near the hills and mountains surrounding the Yucaipa area; the oldest ground water (less than 0.3 picocuries per liter) was found in the Western Heights subbasin. Testing of the vertical contribution of ground water to well 1S/2W-25R4 showed that more than one-half of the water flowed into the well between depths of about 450 and 600 feet below land surface; the rest of the water flowed into the well between 600 and about 850 feet below land surface. At a discharge rate of 750 gallons per minute, virtually no water was contributed to the well below a depth of about 850 feet. The water samples collected at this well ranged in age from less than 50 to less than 400 years before present.

Water-Resources Investigations Report↗
USGS2012

Groundwater quality and simulation of sources of water to wells in the Marsh Creek valley at the U.S. Geological Survey Northern Appalachian Research Laboratory, Tioga County, Pennsylvania

This report provides a November 2010 snapshot of groundwater quality and an analysis of the sources of water to wells at the U.S. Geological Survey (USGS) Northern Appalachian Research Laboratory (NARL) near Wellsboro, Pennsylvania. The laboratory, which conducts fisheries research, currently (2011) withdraws 1,000 gallons per minute of high-quality groundwater from three wells completed in the glacial sand and gravel aquifer beneath the Marsh Creek valley; a fourth well that taps the same aquifer provides the potable supply for the facility. The study was conducted to document the source areas and quality of the water supply for this Department of Interior facility, which is surrounded by the ongoing development of natural gas from the Marcellus Shale. Groundwater samples were collected from the four wells used by the NARL and from two nearby domestic-supply wells. The domestic-supply wells withdraw groundwater from bedrock of the Catskill Formation. Samples were analyzed for major ions, nutrients, trace metals, radiochemicals, dissolved gases, and stable isotopes of oxygen and hydrogen in water and carbon in dissolved carbonate to document groundwater quality. Organic constituents (other than hydrocarbon gases) associated with hydraulic fracturing and other human activities were not analyzed as part of this assessment. Results show low concentrations of all constituents. Only radon, which ranged from 980 to 1,310 picocuries per liter, was somewhat elevated. These findings are consistent with the pristine nature of the aquifer in the Marsh Creek valley, which is the reason the laboratory was sited at this location. The sources of water and areas contributing recharge to wells were identified by the use of a previously documented MODFLOW groundwater-flow model for the following conditions: (1) withdrawals of 1,000 to 3,000 gallons per minute from the NARL wells, (2) average or dry hydrologic conditions, and (3) withdrawals of 1,000 gallons per minute from a new well 3,500 feet to the southwest that was drilled to provide water for Marcellus gas-well operations. Results of simulations indicate that during average hydrologic conditions, infiltration from Straight Run, a tributary to Marsh Creek, provides nearly all the water to the NARL wells. During dry conditions, the areas contributing recharge expand such that Asaph Run contributes about half of the water to the NARL wells when withdrawals are 1,000 or 2,000 gallons per minute. The addition of a simulated withdrawal of 1,000 gallons per minute from the nearby new well does not substantially affect the sources of water captured by the NARL wells. These results are subject to some limitations. The water-quality samples represent a snapshot of groundwater chemistry for only one hydrologic condition; the concentrations of some constituents may change temporally. In addition, samples were collected and analyzed for hydrocarbon gases, but not organic constituents associated with hydraulic fracturing; additional sampling for these constituents would provide a more complete water-quality baseline. The sources contributing water to the NARL wells and the new well were simulated by use of a simplified one-layer model of the glacial sand and gravel aquifer for steady-state conditions that in reality are never achieved. Steady-state simulations of dry hydrologic conditions show that it is possible for the NARL wells to capture water from Asaph Run; however, maps of simulated groundwater time-of-travel indicate that a dry period of unusually long duration would be required. A better analysis could be done by recalibrating the groundwater-flow model with a finite-difference grid having multiple layers, cells smaller than the 200-foot by 200-foot cells used in this study, and transient stress periods.

Pennsylvania↗
USGS2020

Batch extraction method to estimate total dissolved solids (TDS) release from coal refuse and overburden

A rapid batch extraction method was evaluated to estimate potential for total dissolved solids (TDS) release by 65 samples of rock from coal and gas-bearing strata of the Appalachian Basin in eastern USA. Three different extractant solutions were considered: deionized water (DI), DI equilibrated with 10% CO 2 atmosphere (DI + CO 2 ), or 30% H 2 O 2 under 10% CO 2 (H 2 O 2 +CO 2 ). In all extractions, 10 g of pulverized rock (<0.5-mm) were mixed with 20 mL of extractant solution and shaken for 4 h at 50 rpm and 20–22 °C. The 65 rock samples were classified as coal (n=3), overburden (n = 17), coal refuse that had weathered in the field (n = 14), unleached coal refuse that had oxidized during indoor storage (n = 20), gas-bearing shale (n = 10), and pyrite (n = 1). Extracts were analyzed for specific conductance (SC), TDS, pH, and major and trace elements, and subsequently speciated to determine ionic contributions to SC. The pH of extractant blanks decreased in the order DI (6.0), DI + CO 2 (5.1), and H 2 O 2 +CO 2 (2.6). The DI extractant was effective for mobilizing soluble SO 4 and Cl salts. The DI + CO 2 extractant increased weathering of carbonates and resulted in equivalent or greater TDS than the DI leach of the same material. The H 2 O 2 +CO 2 extractant increased weathering of sulfides (and carbonates) and resulted in the greatest TDS production and lowest pH values. Of the 65 samples, 19 had leachate chemistry data from previous column experiments and 35 were paired to 10 field sites with leachate chemistry data. When accounting for the water-to-rock ratio, TDS from DI and DI + CO 2 extractions were correlated to TDS from column experiments while TDS from H 2 O 2 +CO 2 extractions was not. In contrast to column experiments, field SC was better correlated to SC measured from H 2 O 2 +CO 2 extractions than DI extractions. The field SC and SC from H 2 O 2 +CO 2 extractions were statistically indistinguishable for 7 of 9 paired data sets while SC from DI extractions underestimated field SC in 5 of 9 cases. Upscaling comparisons suggest that (1) weathering reactions in the field are more aggressive than DI water or synthetic rainwater extractants used in batch or column tests, and (2) a batch extraction method utilizing 30% H 2 O 2 (which is mildly acidic without CO 2 enrichment) could be effective for identifying rocks that will release high amounts of TDS.

Applied Geochemistry↗
USGS1970

Chemical indicators of subsurface temperature applied to hot spring waters of Yellowstone National Park, Wyoming, U.S.A.

Under favorable conditions the chemistry of hot springs may give reliable indications of subsurface temperatures and circulation patterns. These chemical indicators can be classified by the type of process involved: Indicator Dominant Process The silica geothermometer Solution-precipitation Alkali ratios Ion exchange Cl/(HCO 3 + CO 3 ) ratio Rock alteration by dissolved CO 2 Relative concentration of Partitioning owing to subsur- volatiles in spring water face boning All these indicators have certain limitations. The silica geothermometer gives results independent of the local mineral suite and gas partial pressures, but may be affected by dilution. Alkali ratios are strongly affected by the local mineral suite and the formation of complex ions. Carbonate-chloride ratios are strongly affected by subsurface P CO2 . The relative concentration of volatiles can be very misleading in high-pressure liquid systems. In Yellowstone National Park most thermal waters issue from hot, shallow aquifers with pressures in excess of hydrostatic by 2 to 6 bars and with large flows (the flow of hot spring water from the Park is greater than 4000 liters per second). These conditions should be ideal for the use of chemical indicators to estimate aquifer temperatures. In five drill holes aquifer temperatures were within 2°C of that predicted from the silica content of nearby hot springs; the temperature level off at a lower value than predicted in only one hole, and in four other holes drilling was terminated before the predicted aquifer temperature was reached. The temperature-Na/K ratio relationship does not follow any published experimental or empirical curve for water-feldspar or water-clay reactions. We suspect that ion exchange reactions involving zeolites in the Yellowstone rocks result in higher Na/K ratios at given temperatures than result from feldspar or clay reactions. Comparison of SiO 2 and Cl/(HCO 3 + CO 3 ) suggest that because of higher subsurface P CO2 in Upper Geyser Basin a given Cl/(HCO 3 + CO 3 ) ratio there means a higher temperature than in Lower Geyser Basin. No correlation was found in Yellowstone Park between the subsurface regions of highest temperature and the relative concentration of volatile components such as boron and ammonia.

Wyoming↗
USGS2010

Geology, geochemistry, and geophysics of the Fry Canyon uranium/copper project site, southeastern Utah: Indications of contaminant migration

The Fry Canyon uranium/copper project site in San Juan County, southeastern Utah, was affected by the historical (1957–68) processing of uranium and copper-uranium ores. Relict uranium tailings and related ponds, and a large copper heap-leach pile at the site represent point sources of uranium and copper to local soils, surface water, and groundwater. This study was designed to establish the nature, extent, and pathways of contaminant dispersion. The methods used in this study are applicable at other sites of uranium mining, milling, or processing. The uranium tailings and associated ponds sit on a bench that is as much as 4.25 meters above the level of the adjacent modern channel of Fry Creek. The copper heap leach pile sits on bedrock just south of this bench. Contaminated groundwater from the ponds and other nearby sites moves downvalley and enters the modern alluvium of adjacent Fry Creek, its surface water, and also a broader, deeper paleochannel that underlies the modern creek channel and adjacent benches and stream terraces. The northern extent of contaminated groundwater is uncertain from geochemical data beyond an area of monitoring wells about 300 meters north of the site. Contaminated surface water extends to the State highway bridge. Some uranium-contaminated groundwater may also enter underlying bedrock of the Permian Cedar Mesa Sandstone along fracture zones. Four dc-resistivity surveys perpendicular to the valley trend were run across the channel and its adjacent stream terraces north of the heap-leach pile and ponds. Two surveys were done in a small field of monitoring wells and two in areas untested by borings to the north of the well field. Bedrock intercepts, salt distribution, and lithologic information from the wells and surface observations in the well field aided interpretation of the geophysical profiles there and allowed interpretation of the two profiles not tested by wells. The geophysical data for the two profiles to the north of the well field suggest that the paleochannel persists at least 900 m to the north of the heap leach and pond sites. Contamination of groundwater beneath the stream terraces may extend at least that far. Fry Creek surface water (six samples), seeps and springs (six samples), and wells (eight samples) were collected during a dry period of April 16–19, 2007. The most uranium-rich (18.7 milligrams per liter) well water on the site displays distinctive Ca-Mg-SO 4 -dominant chemistry indicating the legacy of heap leaching copper-uranium ores with sulfuric acid. This same water has strongly negative δ 34 S of sulfate (–13.3 per mil) compared to most local waters of –2.4 to –5.4 per mil. Dissolved uranium species in all sampled waters are dominantly U(VI)-carbonate complexes. All waters are undersaturated with respect to U(VI) minerals. The average 234 U/ 238 U activity ratio (AR) in four well waters from the site (0.939±0.011) is different from that of seven upstream waters (1.235±0.069). This isotopic contrast permits quantitative estimates of mixing of site-derived uranium with natural uranium in waters collected downstream. At the time of sampling, uranium in downstream surface water was mostly (about 67 percent) site-derived and subject to further concentration by evaporation. Three monitoring wells located approximately 0.4 kilometer downstream contained dominantly (78–87 percent) site-derived uranium. Distinctive particles of chalcopyrite (CuFeS) and variably weathered pyrite (FeS 2 ) are present in tailings at the stream edge on the site and are identified in stream sediments 1.3 kilometers downstream, based on inspection of polished grain mounts of magnetic mineral separates.

Utah↗
USGS2015

Characterization of hydrology and water quality of Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado, March 2012

Previous studies by the U.S. Geological Survey identified Alkali Flat as an area of groundwater upwelling, with increases in concentrations of total dissolved solids, and streamflow loss, but additional study was needed to better characterize these observations. The U.S. Geological Survey, in cooperation with the Bureau of Land Management, White River Field Office, conducted a study to characterize the hydrology and water quality of Piceance Creek in the Alkali Flat area of Rio Blanco County, Colorado. Water-quality samples were collected at five springs on March 27, 2012, to determine field properties, major ions, trace elements, and stable isotopes of water. Major-ion and trace-element chemistry indicated that the springs sampled as part of this study were likely recharged by the bedrock aquifer. Isotopic values for the springs plotted close to that of groundwater from the Parachute Creek Member of the Green River Formation, and the isotopic values from both of these sources are similar to the values for Grand Mesa snow. Based on fluoride, lithium, and strontium concentrations, one spring appeared to have different source water than the other four springs. The spring also had higher concentrations of calcium, magnesium, and sulfate relative to the other four springs. Trace-element and major-ion data indicate that this spring was sourced from the Uinta Formation. It was likely the other four springs were primarily sourced from the lower part of the Parachute Creek Member of the Green River Formation as indicated by low sulfate concentrations and high fluoride, lithium, and boron concentrations. Water-quality samples were collected at 16 surface-water-quality sites on March 14, 2012, to determine field properties, major ions, and trace elements. Sodium was the dominant cation and concentrations increased steadily from upstream to downstream along the study reach. Calcium, magnesium, and potassium concentrations remained relatively stable along the study reach. Strontium concentrations were relatively stable along the study reach, whereas boron and lithium concentrations increased appreciably at site PC22031 and remained elevated to the end of the study reach. Loading profiles were used to further refine areas of spring and groundwater input and streamflow gains and losses. Although there was a minor gain in streamflow from sites PC21543 to PC21816 (58 to 59 cubic feet per second (ft 3 /s) during March 2014), the observed increase in dissolved solids load indicated groundwater contribution to Piceance Creek between these two sites. From sites PC22737 to PC22980, dissolved solids load decreased, which was not observed in concentration profiles and indicated that streamflow loss occurred between these two sites. Barium, boron, lithium, and strontium loads showed similar patterns to that of the major ions along the study reach and indicated similar areas of groundwater gain and loss. Boron and lithium load were not observed to decrease in a similar pattern to that of barium and strontium load which would suggest the contribution to the stream from sources with similar chemistry to that of spring sites PCSP2 through PCSP5. Sodium, chloride, and bicarbonate loads increased and decreased along the study reach in a pattern similar to that of dissolved solids load. A chemical mass balance was used to estimate the amount of groundwater and (or) spring water that contributed to the observed changes in water quality along Piceance Creek. This analysis indicated only 5 percent spring water would need to reach Piceance Creek to result in the observed changes in water quality. Instantaneous streamflow was measured from sites PC20133 to PC23721 during field reconnaissance (February 2012) and during synoptic sampling (March 2012). During both February and March, the study reach from sites PC20133 to PC23721 was a losing reach with net losses that ranged from 0.5 ft 3 /s (February) to 3 ft 3 /s (March). Observed changes in streamflow along the study reach helped to depict interactions between groundwater and surface water in the Alkali Flat area. Water-quality samples were collected at five surface-water sites in December 2010 that were sampled as part of a previous USGS study in 2000. Water-quality data collected during December 2010 showed no appreciable difference from water-quality data collected during December 2000 at the five sites.

Colorado↗
USGS1999

Formation of natural gas hydrates in marine sediments 1. Conceptual model of gas hydrate growth conditioned by host sediment properties

The stability of submarine gas hydrates is largely dictated by pressure and temperature, gas composition, and pore water salinity. However, the physical properties and surface chemistry of deep marine sediments may also affect the thermodynamic state, growth kinetics, spatial distributions, and growth forms of clathrates. Our conceptual model presumes that gas hydrate behaves in a way analogous to ice in a freezing soil. Hydrate growth is inhibited within fine-grained sediments by a combination of reduced pore water activity in the vicinity of hydrophilic mineral surfaces, and the excess internal energy of small crystals confined in pores. The excess energy can be thought of as a "capillary pressure" in the hydrate crystal, related to the pore size distribution and the state of stress in the sediment framework. The base of gas hydrate stability in a sequence of fine sediments is predicted by our model to occur at a lower temperature (nearer to the seabed) than would be calculated from bulk thermodynamic equilibrium. Capillary effects or a build up of salt in the system can expand the phase boundary between hydrate and free gas into a divariant field extending over a finite depth range dictated by total methane content and pore-size distribution. Hysteresis between the temperatures of crystallization and dissociation of the clathrate is also predicted. Growth forms commonly observed in hydrate samples recovered from marine sediments (nodules, and lenses in muds; cements in sands) can largely be explained by capillary effects, but kinetics of nucleation and growth are also important. The formation of concentrated gas hydrates in a partially closed system with respect to material transport, or where gas can flush through the system, may lead to water depletion in the host sediment. This "freeze-drying" may be detectable through physical changes to the sediment (low water content and overconsolidation) and/or chemical anomalies in the pore waters and metastable presence of free gas within the normal zone of hydrate stability.

Journal of Geophysical Research B: Solid Earth↗
USGS2016

Soil moisture and biogeochemical factors influence the distribution of annual Bromus species

Abiotic factors have a strong influence on where annual Bromus species are found. At the large regional scale, temperature and precipitation extremes determine the boundaries of Bromus occurrence. At the more local scale, soil characteristics and climate influence distribution, cover, and performance. In hot, dry, summer-rainfall-dominated deserts (Sonoran, Chihuahuan), little or no Bromus is found, likely due to timing or amount of soil moisture relative to Bromus phenology. In hot, winter-rainfall-dominated deserts (parts of the Mojave Desert), Bromus rubens is widespread and correlated with high phosphorus availability. It also responds positively to additions of nitrogen alone or with phosphorus. On the Colorado Plateau, with higher soil moisture availability, factors limiting Bromus tectorum populations vary with life stage: phosphorus and water limit germination, potassium and the potassium/magnesium ratio affect winter performance, and water and potassium/magnesium affect spring performance. Controlling nutrients also change with elevation. In cooler deserts with winter precipitation (Great Basin, Columbia Plateau) and thus even greater soil moisture availability, B. tectorum populations are controlled by nitrogen, phosphorus, or potassium. Experimental nitrogen additions stimulate Bromus performance. The reason for different nutrients limiting in dissimilar climatic regions is not known, but it is likely that site conditions such as soil texture (as it affects water and nutrient availability), organic matter, and/or chemistry interact in a manner that regulates nutrient availability and limitations. Under future drier, hotter conditions, Bromus distribution is likely to change due to changes in the interaction between moisture and nutrient availability.

Book chapter↗
USGS2019

Water-quality and geochemical variability in the Little Arkansas River and Equus Beds aquifer, south-central Kansas, 2001–16

This fact sheet describes water quality and geochemistry of the Little Arkansas River and Equus Beds aquifer during 2001 through 2016 as part of the City of Wichita’s Equus Beds aquifer storage and recovery project in south-central Kansas. The Equus Beds aquifer storage and recovery project was developed to help meet future water demand by pumping water out of the Little Arkansas River (during above-base-flow conditions), treating it using National Primary Drinking Water Regulations as a guideline, and injecting it into the aquifer for later use. Water-quality data were collected and analyzed by the U.S. Geological Survey from 2 Little Arkansas River surface-water sites and 63 Equus Beds groundwater sites, including 38 areal assessment index wells, each of which has a shallow well and a deep well. About 4,700 surface and groundwater samples were collected and analyzed for more than 300 water-quality constituents. About 1,300 groundwater chemistry samples were geochemically modeled. Constituents of concern in the Equus Beds aquifer exceeded their respective Federal criteria throughout the study period and included chloride, sulfate, nitrate plus nitrite, Escherichia coli ( E. coli ), total coliforms, and dissolved iron and arsenic species.

Kansas↗
USGS2012

Sources and sinks of nitrogen and phosphorus to a deep, oligotrophic lake, Lake Crescent, Olympic National Park, Washington

Lake Crescent, in Olympic National Park in the northwest corner of Washington State is a deep-water lake renowned for its pristine water quality and oligotrophic nature. To examine the major sources and sinks of nutrients (as total nitrogen, total phosphorus, and dissolved nitrate), a study was conducted in the Lake Crescent watershed. The study involved measuring five major inflow streams, the Lyre River as the major outflow, recording weather and climatic data, coring lake bed sediment, and analyzing nutrient chemistry in several relevant media over 14 months. Water samples for total nitrogen, total phosphorous, and dissolved nitrate from the five inflow streams, the outlet Lyre River, and two stations in the lake were collected monthly from May 2006 through May 2007. Periodic samples of shallow water from temporary sampling wells were collected at numerous locations around the lake. Concentrations of nutrients detected in Lake Crescent and tributaries were then applied to the water budget estimates to arrive at monthly and annual loads from various environmental components within the watershed. Other sources, such as leaf litter, pollen, or automobile exhaust were estimated from annual values obtained from various literature sources. This information then was used to construct a nutrient budget for total nitrogen and total phosphorus. The nitrogen budget generally highlights vehicle traffic-diesel trucks in particular-along U.S. Highway 101 as a potential major anthropogenic source of nitrogen compounds in the lake. In contrast, contribution of nitrogen compounds from onsite septic systems appears to be relatively minor related to the other sources identified.

Washington↗
USGS1996

Hydrogeology and chemical quality of water and soil at Carroll Island, Aberdeen Proving Ground, Maryland

Carroll Island was used for open-air testing of chemical warfare agents from the late 1940's until 1971. Testing and disposal activities weresuspected of causing environmental contamination at 16 sites on the island. The hydrogeology and chemical quality of ground water, surface water, and soil at these sites were investigated with borehole logs, environmental samples, water-level measurements, and hydrologic tests. A surficial aquifer, upper confining unit, and upper confined aquifer were defined. Ground water in the surficial aquifer generally flows from the east-central part of the island toward the surface-water bodies, butgradient reversals caused by evapotranspiration can occur during dry seasons. In the confined aquifer, hydraulic gradients are low, and hydraulic head is affected by tidal loading and by seasonal pumpage from the west. Inorganic chemistry in the aquifers is affected by brackish-water intrusion from gradient reversals and by dissolution ofcarboniferous shell material in the confining unit.The concentrations of most inorganic constituents probably resulted from natural processes, but some concentrations exceeded Federal water-quality regulations and criteria. Organic compounds were detected in water and soil samples at maximum concentrations of 138 micrograms per liter (thiodiglycol in surface water) and 12 micrograms per gram (octadecanoic acid in soil).Concentrations of organic compounds in ground water exceeded Federal drinking-water regulations at two sites. The organic compounds that weredetected in environmental samples were variously attributed to natural processes, laboratory or field- sampling contamination, fallout from industrial air pollution, and historical military activities.

Water-Resources Investigations Report↗
USGS2010

Assessing water quality suitability for shortnose sturgeon in the Roanoke River, North Carolina, USA with an in situ bioassay approach

The aim of this study was to determine the suitability of water quality in the Roanoke River of North Carolina for supporting shortnose sturgeon Acipenser brevirostrum, an endangered species in the United States. Fathead minnows Pimephales promelas were also evaluated alongside the sturgeon as a comparative species to measure potential differences in fish survival, growth, contaminant accumulation, and histopathology in a 28-day in situ toxicity test. Captively propagated juvenile shortnose sturgeon (total length 49 ± 8mm, mean ±SD) and fathead minnows (total length 39 ± 3mm, mean ± SD) were used in the test and their outcomes were compared to simultaneous measurements of water quality (temperature, dissolved oxygen, pH, conductivity, total ammonia nitrogen, hardness, alkalinity, turbidity) and contaminant chemistry (metals, polycyclic aromatic hydrocarbons, organochlorine pesticides, current use pesticides, polychlorinated biphenyls) in river water and sediment. In the in situ test, there were three non-riverine control sites and eight riverine test sites with three replicate cages (25 X 15-cm (OD) clear plexiglass with 200-lm tear-resistant Nitex screen over each end) of 20 shortnose sturgeon per cage at each site. There was a single cage of fathead minnows also deployed at each site alongside the sturgeon cages. Survival of caged shortnose sturgeon among the riverine sites averaged 9% (range 1.7-25%) on day 22 of the 28-day study, whereas sturgeon survival at the non-riverine control sites averaged 64% (range 33-98%). In contrast to sturgeon, only one riverine deployed fathead minnow died (average 99.4% survival) over the 28-day test period and none of the control fathead minnows died. Although chemical analyses revealed the presence of retene (7-isopropyl-1-methylphenanthrene), a pulp and paper mill derived compound with known dioxin-like toxicity to early life stages of fish, in significant quantities in the water (251-603ngL-1) and sediment (up to 5000ngg-1 dry weight) at several river sites, no correlation was detected of adverse water quality conditions or measured contaminant concentrations to the poor survival of sturgeon among riverine test sites. Histopathology analysis determined that the mortality of the river deployed shortnose sturgeon was likely due to liver and kidney lesions from an unknown agent(s). Given the poor survival of shortnose sturgeon (9%) and high survival of fathead minnows (99.4%) at the riverine test sites, our study indicates that conditions in the Roanoke River are incongruous with the needs of juvenile shortnose sturgeon and that fathead minnows, commonly used standard toxicity test organisms, do not adequately predict the sensitivity of shortnose sturgeon. Therefore, additional research is needed to help identify specific limiting factors and management actions for the enhancement and recovery of this imperiled fish species.

North Carolina↗
USGS2006

Questa baseline and pre-mining ground-water quality investigation. 23. Quantification of mass loading from mined and unmined areas along the Red River, New Mexico

Along the course of the Red River, between the town of Red River, New Mexico, and the U.S. Geological Survey streamflow-gaging station near Questa, New Mexico, there are several catchments that contain hydrothermally altered bedrock. Some of these alteration zones have been mined and others have not, presenting an opportunity to evaluate differences that may exist in the mass loading of metals from mined and unmined sections. Such differences may help to define pre-mining conditions. Spatially detailed chemical sampling at stream and inflow sites occurred during low-flow conditions in 2001 and 2002, and during the synoptic sampling, stream discharge was calculated by tracer dilution. Discharge from most catchments, particularly those with alteration scars, occurred as ground water in large debris fans, which generally traveled downstream in an alluvial aquifer until geomorphic constraints caused it to discharge at several locations along the study reach. Locations of discharge zones were indicated by the occurrence of numerous inflows as seeps and springs. Inflows were classified into four groups, based on differences in chemical character, which ranged from near-neutral water showing no influence of mining or alteration weathering to acidic water with high concentrations of metals and sulfate. Acidic, metal-rich inflows occurred from mined and unmined areas, but the most-acidic inflow water that had the highest concentrations of metals and sulfate only occurred downstream from the mine. Locations of ground-water inflow also corresponded to substantial changes in stream chemistry and mass loading of metals and sulfate. The greatest loading occurred in the Cabin Springs, Thunder Bridge, and Capulin Canyon sections, which all occur downstream from the mine. A distinct chemical character and substantially greater loading in water downstream from the mine suggest that there could be impacts from mining that can be distinguished from the water draining from unmined areas.

New Mexico↗
USGS1981

Water Resources Research October 1, 1979 - September 30, 1980: Summary statements of research activities by the Water Resources Division

Research in the WRD had its beginnings in the late 1950's when the "core research" line item was added to the Congressional budget. Since this time the Federal program has grown from a "basic sciences" program to one that includes a broad spectrum of basic and applied scientific investigations. Water resources research in WRD includes the study of water in all its phases and uses the basic sciences of mathematics, chemistry, physics, biology, geology and engineering to gain a fundamental understanding of the processes that affect the movement of water and its chemical constituents through hydrologic systems. The basic knowledge and methodologies derived from water resources research are applicable not only to the solution of current problems associated with the Nation's water resources, but also to anticipated hydrologic issues.

Report↗
USGS2014

Morphology-dependent water budgets and nutrient fluxes in arctic thaw ponds

Thaw ponds on the Arctic Coastal Plain of Alaska are productive ecosystems, providing habitat and food resources for many fish and bird species. Permafrost in this region creates unique pond morphologies: deep troughs, shallow low-centred polygons (LCPs) and larger coalescent ponds. By monitoring seasonal trends in pond volume and chemistry, we evaluated whether pond morphology and size affect water temperature and desiccation, and nitrogen (N) and phosphorus (P) fluxes. Evaporation was the largest early-summer water flux in all pond types. LCPs dried quickly and displayed high early-summer nutrient concentrations and losses. Troughs consistently received solute-rich subsurface inflows, which accounted for 12 to 42 per cent of their volume and may explain higher P in the troughs. N to P ratios increased and ammonium concentrations decreased with pond volume, suggesting that P and inorganic N availability may limit ecosystem productivity in older, larger ponds. Arctic summer temperatures will likely increase in the future, which may accelerate mid-summer desiccation. Given their morphology, troughs may remain wet, become warmer and derive greater nutrient loads from their thawing banks. Overall, seasonal- to decadal-scale warming may increase ecosystem productivity in troughs relative to other Arctic Coastal Plain ponds.

Alaska↗