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USGS1989

Uranium in Holocene valley-fill sediments, and uranium, radon, and helium in waters, Lake Tahoe-Carson Range area, Nevada and California, U.S.A.

Uraniferous Holocene sediments occur in the Carson Range of Nevada and California, U.S.A., between Lake Tahoe and Carson Valley. The hosts for the uranium include peat and interbedded organic-rich sand, silt, and mud that underly valley floors, fens, and marshes along stream valleys between the crest of the range and the edge of Lake Tahoe. The known uranium accumulations extend along the Carson Range from the area just southeast of South Lake Tahoe northward to the area just east of Carson City; however, they almost certainly continue beyond the study area to the north, west, and south. Due to the young age of the accumulations, uranium in them is in gross disequilibrium with its highly radioactive daughter products. These accumulations have thus escaped discovery with radiation detection equipment in the past. The uranium content of these sediments approaches 0.6 percent; however, the average is in the range of 300-500 ppm. Waters associated with these sediments locally contain as much as 177 ppb uranium. Modest levels of helium and radon also occur in these waters. Uraniferous waters are clearly entering the private and public water supply systems in some parts of the study area; however, it is not known how much uranium is reaching users of these water supplies. Many of the waters sampled in the study area exceed the published health effects guidance level of the Environmental Protection Agency. Regulatory standards for uranium in waters have not been published, however. Much uranium is stored in the sediments along these stream valleys. Estimates for a marsh and a fen along one drainage are 24,000 and 15,000 kg, respectively. The potential effects of man-induced environmental changes on the uranium are uncertain. Laboratory studies of uraniferous sediment rich in organic matter may allow us to evaluate the potential of liberating uranium from such sediments and creating transient increases in the level of uranium moving in water in the natural environment. ?? 1989 Springer-Verlag New York Inc.

Environmental Geology and Water Sciences↗

USGS2021

Simulated effects of sea-level rise on the shallow, fresh groundwater system of Assateague Island, Maryland and Virginia

The U.S. Geological Survey, in cooperation with the National Park Service, developed a three-dimensional groundwater-flow model for Assateague Island in eastern Maryland and Virginia to assess the effects of sea-level rise on the groundwater system. Sea-level rise is expected to increase the altitude of the water table in barrier island aquifer systems, possibly leading to adverse effects to ecosystems on the barrier islands. The potential effects of sea-level rise were evaluated by simulating groundwater conditions under sea-level-rise scenarios of 20 centimeters (cm), 40 cm, and 60 cm. Results show that as sea level rises, low-lying areas of the island originally represented as receiving freshwater recharge in the baseline scenario are inundated by saltwater. This change from freshwater recharge to saltwater decreases the overall amount of freshwater recharging the system. As the water table rises in response to the higher sea levels, freshwater flow out of the system changes, with more freshwater leaving as submarine groundwater discharge and less freshwater leaving as seeps and evapotranspiration. At the current land-surface altitude, as much as 50 percent of the island may be inundated with a 60-cm rise in sea level, and the low-lying marshes may change from freshwater to saltwater. Groundwater levels at 32 wells were monitored for as long as 12 months between October 2014 and September 2015 on Assateague Island. Results from objective classification analysis of 14 shallow monitoring wells show two dominant processes affecting groundwater levels in two different settings on the island. On the western side of the island, between the primary dune and the inland bays, water levels clearly respond to precipitation events. This side of the island is more protected from ocean tides and typically is more vegetated than the eastern side. On the eastern side of the island, between the Atlantic Ocean and the primary dune, water levels clearly respond to tidal events. Specific conductance was measured at four wells, two on the western part of the island and two on the eastern part of the island. Specific conductance values in the two wells west of the primary dune show episodic decreases, coinciding with precipitation events. Specific conductance values in the two wells on the eastern side of the primary dune show episodic increases, coinciding with high-tide events. These high frequency monitoring data are intended to aid in designing a monitoring network that can document both short-term and long-term hydrologic processes on Assateague Island National Seashore. This study uses a modeling approach consistent with models developed for Gateway National Recreation Area, Sandy Hook Unit (New Jersey) and Fire Island National Seashore (New York). Combined, these models are meant to improve the regional capabilities for predicting climate-change effects on barrier islands and provide resource managers with a common set of tools for adaptation and mitigation of potentially adverse effects of sea-level rise.

Maryland, Virginia↗

USGS1993

The Geysers-Clear Lake area, California: Thermal waters, mineralization, volcanism, and geothermal potential

Manifestations of a major thermal anomaly in the Geysers-Clear Lake area of northern California include the late Pliocene to Holocene Clear Lake Volcanics, The Geysers geothermal field, abundant thermal springs, and epithermal mercury and gold mineralization. The epithermal mineralization and thermal springs typically occur along high-angle faults within the broad San Andreas transform fault system that forms the western boundary of the North American plate in this area. The young volcanic rocks overlie Mesozoic marine rocks of the Great Valley sequence which have been thrust above the coeval Franciscan Complex and penecontemporaneously dropped back down along low-angle detachment faults.Many of the waters of the region are nonmeteoric as defined by their isotopic signature. One type of isotopically shifted water emerges from or near Great Valley sequence rocks and is the most chloride rich. It is interpreted to be evolved connate in origin. A second type, evolved meteoric water, has moderate chloride contents, high boron contents, and high B/Cl ratios and is found locally in Franciscan rocks, notably at the Sulphur Bank mercury mine, where it probably results from near-closed-system, repeated boiling of meteoric water in host rocks that also contribute organic components to the water. At the Sulphur Bank mine fracturing of otherwise impermeable Franciscan rocks by faulting has created a localized zone of permeability in which thermal water boils repeatedly with limited venting to the surface. Boron-rich fluids were apparently present at depth in The Geysers geothermal field when intrusion of silicic magma occurred, because the concealed intrusion of felsite is surrounded by a halo of tourmaline-bearing hornfels. The volume of this poorly dated early to middle Quaternary intrusive body probably exceeds the 100 km 3 of erupted Clear Lake Volcanics. Similar intrusions may have occurred in the eastern part of the area at Wilbur Springs and the McLaughlin mine, where gold deposition and evidence of hydrothermal phenomena suggest more magmatic activity than is indicated by the small exposed bodies of early Quaternary basaltic lava. The Clear Lake Volcanics are the present locus of volcanism in the northern Coast Ranges and progressively older volcanic centers occur to the south. Geophysical data suggest that a large silicic magma body may be centered north of The Geysers steam field, providing the heat for the geothermal field.Geothermal power production has peaked at The Geysers and pressure declines indicate significant depletion of the fluid resource. The vapor-dominated field evolved from a preexisting hydrothermal system within fractured, otherwise impermeable Franciscan metamorphic rocks. A deep water table of saline fluid has been postulated to be present under the steam field, but no chloride-rich water has been found at drillable depth. We propose that recently discovered, isotopically shifted steam in the northwest Geysers area indicates the presence not of deep connate water but xather of boiled-down, boron-rich Franciscan evolved meteoric water. This water is likely to be present in limited quantities and will not provide a significant hot water resource for geothermal power production at The Geysers field or from the main Clear Lake volcanic field.

Economic Geology↗

USGS2006

Pleistocene corals of the Florida keys: Architects of imposing reefs - Why?

Five asymmetrical, discontinuous, stratigraphically successive Pleistocene reef tracts rim the windward platform margin off the Florida Keys. Built of large head corals, the reefs are imposing in relief (???30 m high by 1 km wide), as measured from seismic profiles. Well dated to marine oxygen isotope substages 5c, 5b, and 5a, corals at depth are inferred to date to the Stage 6/5 transition. The size of these reefs attests to late Pleistocene conditions that repeatedly induced vigorous and sustained coral growth. In contrast, the setting today, linked to Florida Bay and the Gulf of Mexico, is generally deemed marginal for reef accretion. Incursion onto the reef tract of waters that contain seasonally inconsistent temperature, salinity, turbidity, and nutrient content impedes coral growth. Fluctuating sea level and consequent settings controlled deposition. The primary dynamic was position of eustatic zeniths relative to regional topographic elevations. Sea level during the past 150 ka reached a maximum of ???10.6 m higher than at present ???125 ka, which gave rise to an inland coral reef (Key Largo Limestone) and ooid complex (Miami Limestone) during isotope substage 5e. These formations now form the Florida Keys and a bedrock ridge beneath The Quicksands (Gulf of Mexico). High-precision radiometric ages and depths of dated corals indicate subsequent apices remained ???15 to 9 m, respectively, below present sea level. Those peaks provided accommodation space sufficient for vertical reef growth yet exposed a broad landmass landward of the reefs for >100 ka. With time, space, lack of bay waters, and protection from the Gulf of Mexico, corals thrived in clear oceanic waters of the Gulf Stream, the only waters to reach them.

Journal of Coastal Research↗

USGS2010

Nitrate-N movement in groundwater from the land application of treated municipal wastewater and other sources in the Wakulla Springs springshed, Leon and Wakulla Counties, Florida, 1966-2018

The City of Tallahassee began a pilot study in 1966 at the Southwest Farm sprayfield to determine whether disposal of treated municipal wastewater using center pivot irrigation techniques to uptake nitrate-nitrogen (nitrate-N) is feasible. Based on the early success of this project, a new, larger Southeast Farm sprayfield was opened in November 1980. However, a recent 2002 study indicated that nitrate-N from these operations may be moving through the Upper Floridan aquifer to Wakulla Springs, thus causing nitrate-N concentrations to increase in the spring water. The increase in nitrate-N combined with the generally clear spring water and abundant sunshine may be encouraging invasive plant species growth. Determining the link between the nitrate-N application at the sprayfields and increased nitrate-N levels is complicated because there are other sources of nitrate-N in the Wakulla Springs springshed, including atmospheric deposition, onsite sewage disposal systems, disposal of biosolids by land spreading, creeks discharging into sinks, domestic fertilizer application, and livestock wastes. Groundwater flow and fate and transport modeling were conducted to simulate the effect of all of the nitrate-N sources on Wakulla Springs from January 1, 1966, through December 31, 2018. The total simulated nitrate-N load to Wakulla Springs in 1967 was a relatively modest 69,000 kilograms per year (kg/yr). The major sources of the nitrate-N load in 1967 were determined to be: 1. Inflow to the study area across the lateral model boundaries at 31,000 kg/yr (45 percent), 2. Biosolids disposal by land spreading at 14,000 kg/yr (20 percent), 3. Creeks discharging into sinks at 7,800 kg/yr (11 percent), and 4. The Southwest Farm sprayfield at 4,500 kg/yr (7 percent). The total simulated nitrate-N load to Wakulla Springs in 1987 had increased dramatically to 297,000 kg/yr. The major sources of nitrate-N load in 1987 were determined to be: 1. The Southeast Farm sprayfield at 186,000 kg/yr (63 percent), 2. Biosolids at 37,000 kg/yr (12 percent), and 3. Inflow to the study area across the lateral model boundaries at 36,000 at kg/yr (12 percent). All of the other sources were 5 percent or less. The Wakulla Springs discharge can change rapidly, even during periods of little or no rainfall. This rapid change is probably the result of Wakulla Springs intermittently capturing groundwater that has been going to the Spring Creek Springs Group. This spring group is located in a marine estuary and is affected by tidally influenced saltwater intrusion. Two modeling scenarios were simulated and results are presented for 2007 and 2018 in an effort to bracket the range of possible current and future changes in the flow of Wakulla Springs. In scenario 1, it was assumed that Wakulla Springs was not capturing Spring Creek Springs Group flow. In scenario 2, it was assumed that Wakulla Springs was capturing Spring Creek Springs Group flow. Under the assumptions of scenario 1, the total simulated nitrate-N load to Wakulla Springs in 2007 was 207,200 kg/yr. The major sources of nitrate-N load were determined to be: 1. The Southeast Farm sprayfield at 111,000 kg/yr 53 percent), 2. Inflow to the study area across the lateral model boundaries at 44,000 at kg/yr (21 percent), and 3. Onsite sewage disposal systems at 24,000 kg/yr (12 percent). All of the other sources contributed 6 percent or less. Under the assumptions of scenario 2, the total simulated nitrate-N load to Wakulla Springs was 294,000 kg/yr. The major sources of nitrate-N load were determined to be: 1. The Southeast Farm sprayfield at 111,000 kg/yr (38 percent), 2. Onsite sewage disposal systems at 56,000 kg/yr (19 percent), 3. Inflow to the study area across the lateral model boundaries at 52,000 at kg/yr (18 percent), and 4. Creeks discharging into sinks at 31,000 kg/yr (11 percent). All of the other sources contributed 8 percent or less. The nitrate-N loads to Wakulla Springs from the Southeast Farm sprayfield for scenarios 1 and 2 were both 111,000 kg/yr. These amounts were the same because most of the water from the Southeast Farm sprayfield went into Wakulla Springs in both simulations. In contrast, the nitrate-N loads from onsite sewage disposal systems for scenarios 1 and 2 were 24,000 kg/yr and 56,000 kg/yr, respectively. The additional water captured by Wakulla Springs in scenario 2 came from an area that had a high density of residential and commercial sites using onsite sewage disposal systems Under the assumptions of scenario 1, the total simulated nitrate-N load to Wakulla Springs in 2018 will be 156,000 kg/yr. The major sources of nitrate-N load for scenario 1 are anticipated to be: 1. Inflow to the study area across the lateral model boundaries at 48,000 at kg/yr (31 percent), 2. The Southeast Farm sprayfield at 42,000 kg/yr (27 percent), 3. Onsite sewage disposal systems at 32,000 kg/yr (21 percent), and 4. Fertilizer at 17,000 kg/yr (11 percent). All of the other sources will contribute 5 percent or less. Under the assumptions of scenario 2, the total simulated nitrate-N load to Wakulla Springs in 2018 will be 266,000 kg/yr. The major sources of nitrate-N load for scenario 2 are anticipated to be: 1. Onsite sewage disposal systems at 80,000 kg/yr (30 percent), 2. Inflow to the study area across the lateral model boundaries at 57,000 at kg/yr (21 percent), 3. The Southeast Farm sprayfield at 43,000 kg/yr (16 percent), 4. Creeks discharging into sinks at 31,000 kg/yr (12 percent), and 5. Fertilizer at 32,000 kg/yr (12 percent). All of the other sources will contribute 6 percent or less. The simulated nitrate-N load from the Southeast Farm sprayfield to Wakulla Springs during 2007 through 2018 decreases from 111,000 kg/yr to 42,000 kg/yr in scenario 1 and decreases from 111,000 kg/yr to 43,000 kg/yr in scenario 2. Both scenarios show these decreases because of the simulated planned reduction in the concentration of nitrate-N in the wastewater used for irrigation from approximately 12 milligrams per liter (mg/L) in 2007 to 3 mg/L in 2018. In contrast, the simulated nitrate-N load from onsite sewage disposal systems to Wakulla Springs from 2007 through 2018 increases from 24,000 kg/yr to 32,000 kg/yr in scenario 1, and increases from 56,000 kg/yr to 80,000 kg/yr in scenario 2. Both scenarios show increases respective to the increases in population and residential and commercial sites using onsite sewage disposal systems. In addition, the simulated nitrate-N load to Wakulla Springs from 2007 through 2018 from inflow to the study area across the lateral model boundaries increases from 44,000 kg/yr to 48,000 kg/yr in scenario 1, and increases from 54,000 kg/yr to 57,000 kg/yr in scenario 2. Both scenarios show increases due to increasing nitrate-N levels upgradient in Leon County.

Scientific Investigations Report↗

USGS1995

Effects of selective forest clearing fertilization, and liming on the hydrology and water quality of a small tributary to the Quabbin Reservoir, central Massachusetts

Effects of selective forest clearing on water yield and water quality were investigated in a 308-hectare basin that drains to Quabbin Reservoir Watershed in central Massachusetts. The experimental basin and a nearby 280-hectare control basin were studied together for comparison. Streamflow was measured continuously and water-quality samples were collected biweekly in both basins from February 1985 through September 1989. During the same period, measurements of precipitation quantity and ground- water levels were made and samples were collected for determination of precipitation and ground-water quality. After an initial monitoring period to establish baseline hydrology and water quality in both basins, an area of red pine and white pine forest in the experimental basin was cleared. From October 1986 until April 1987, 23.8 percent of the total basal area was removed by clearcutting and thinning. Part of the cleared area was converted to rye and other field grasses, and the remainder was allowed to regrow naturally. Fertilizer and lime were applied to part of the cleared area. An additional 8.3 percent of basal area was cleared in fall 1988. Despite differences in bedrock geology, topography, and amount of wetland area, pre- treatment hydrology and chemistry of the two basins were similar. Biogeochemical reactions of the dilute mixture of sulfuric and nitric acids in precipitation with soils and rocks in the basins resulted in moderately buffered calcium-magnesium bicarbonate-type streamwater. During high flows, sulfate concentrations increased and alkalinity decreased. Selective forest clearing resulted in a slight increase in water yield during the year in which the clearing took place, particularly during the spring high-flow period, but flows returned to normal thereafter. Concurrent increases in solute flux were primarily a function of the increased water flux. No major alterations to biogeochemical processes were induced by the forest clearing, nor were any effects from the fertilizer or liming activity observed. The minimal effect observed from the clearing was attributed primarily to the limited area that was cleared, and the location of the cleared area in the headwaters of the basin (away from the riparian zone).

Massachusetts↗

USGS1988

National water summary 1986: Hydrologic events and ground-water quality

Ground water is one of the most important natural resources of the United States and degradation of its quality could have a major effect on the welfare of the Nation. Currently (1985), ground water is the source of drinking water for 53 percent of the Nation's population and for more than 97 percent of its rural population. It is the source of about 40 percent of the Nation's public water supply, 33 percent of water for irrigation, and 17 percent of freshwater for selfsupplied industries. Ground water also is the source of about 40 percent of the average annual streamflow in the United States, although during long periods of little or no precipitation, ground-water discharges provide nearly all of the base streamflow. This hydraulic connection between aquifers and streams implies that if a persistent pollutant gets into an aquifer, it eventually could discharge into a stream. Information presented in the 1986 National Water Summary clearly shows that the United States has very large amounts of potable ground water available for use. Although naturally occurring constituents, such as nitrate, and human-induced substances, such as synthetic organic chemicals, frequently are detected in ground water, their concentrations usually do not exceed existing Federal or State standards or guidelines for maximum concentrations in drinking water. Troublesome contamination of ground water falls into two basic categories related to the source or sources of the contamination. Locally, high concentrations of a variety of toxic metals, organic chemicals, and petroleum products have been detected in ground water associated with point sources such as wastedisposal sites, storage-tank leaks, and hazardous chemical spills. These types of local problems commonly occur in densely populated urban areas and industrialized areas. Larger, multicounty areas also have been identified where contamination frequently is found in shallow wells. These areas generally are associated with broad-scale, or nonpoint, sources of contamination such as agricultural activities or highdensity domestic waste disposal (septic systems) in urban centers. At present, only a very small percentage of the total volume of potable ground water in the United States is contaminated from both point and nonpoint sources; however, available data, especially data about the occurrence of synthetic organic and toxic substances, generally are inadequate to determine the full extent of ground-water contamination in the Nation's aquifers or to define trends in groundwater quality. Most information about the occurrence of these substances has come from the study of individual sites or areas where contamination had already been detected or suspected. Management and protection of ground water present a major challenge to the Nation. Current and projected costs of detection and cleanup of existing ground-water contamination are staggering and, even so, complete removal of pollutants from ground water in the vicinity of some waste sites might not be technically feasible. At all levels of government, the task of protecting the resource for its most beneficial uses is difficult and controversial. Despite increasing awareness that some of the Nation's ground water is contaminated with a variety of toxic metals, synthetic organic chemicals, radionuclides, pesticides, and other contaminants that might present a long-term risk to human health, public policy towards ground-water protection is still in the formative stages. Despite increasing efforts devoted to ground-water protection by State and Federal regulatory and resource-management agencies, the extent of ground-water contamination is likely to appear to increase over the next few years because more agencies will be searching for evidence of contamination, and they will be using increasingly sensitive analytical procedures. Increased technology and expanded monitoring activities probably will detect the effects of past contamination and land uses on water quality. The significant time lag between a waterquality change in one part of an aquifer system and the effects of that change at a downgradient site, such as a well, results from the generally slow movement of ground water. This lag between cause and observed effect needs to be considered in evaluating the effectiveness of current and future ground-water policies and remedial measures. Conclusive answers to questions about the location, extent, and severity of ground-water contamination, and about trends in ground-water quality, must await further collection and analysis of data from the Nation's aquifers. Generalizations, however, can be made, and the 1986 National Water Summary, which describes the natural quality of ground-water resources in each State and the major contamination problems that have been identified as of 1986, provides a national perspective of the ground-water-quality situation. The 1986 National Water Summary follows the format of previous volumes. It contains three parts, and the contents of each of these parts are highlighted below.

Water Supply Paper↗

USGS1980

The Quality of Water Discharging From the New River and Clear Fork Basins, Tennessee

The quality of water discharging from a strip-mined basin and a relatively unmined basin on the Cumberland Plateau in Tennessee are examined and compared. The chemical and aesthetic quality of these waters will directly affect the chemical and aesthetic quality of the water flowing through a proposed national river and recreation area. Water from the heavily mined New River basin is characterized by neutral pH, low dissolved solids (less than 300 milligrams per liter), and high concentrations of suspended sediment. More than 90 percent of the suspended sediment is silt and clay. Suspended-sediment concentrations in the thousands of milligrams per liter are not uncommon for New River and often impart a highly turbid appearance to the water. Approximately 590,000 tons of suspended sediment were discharged from the New River basin in 1977, as compared to an estimated 20,000 tons from the relatively unmined Clear Fork basin. In association with these fine-grain suspended sediments are sorbed trace metals. In 1977 the New River basin discharged an estimated 17,000 tons of suspended iron while Clear Fork discharged an estimated 600 tons. Suspended-sediment concentration was found to be highly correlated with both suspended and total trace-metal concentrations. This correlation coupled with the nearly neutral pH of the water indicates that trace metals are transported primarily in the suspended phase. The most promising indicator of the presence of coal mining was found to be dissolved sulfate. All unmined basins sampled in this study showed dissolved sulfate concentrations less than 20 milligrams per liter, whereas all mined basins had dissolved-sulfate concentrations in excess of 20 milligrams per liter regardless of basin size or discharge.

Water-Resources Investigations Report↗

USGS2007

Thioarsenates in geothermal waters of Yellowstone National Park: Determination, preservation, and geochemical importance

Mono-, di-, tri-, and tetrathioarsenate, as well as methylated arsenic oxy- and thioanions, were determined besides arsenite and arsenate in geothermal waters of Yellowstone National Park using anion-exchange chromatography inductively coupled plasma mass spectrometry. Retention time match with synthetic standards, measured S:As ratios, and molecular electrospray mass spectra support the identification. Acidification was unsuitable for arsenic species preservation in sulfidic waters, with HCl addition causing loss of total dissolved arsenic, presumably by precipitation of arsenic-sulfides. Flash-freezing is preferred for the preservation of arsenic species for several weeks. After thawing, samples must be analyzed immediately. Thioarsenates occurred over a pH range of 2.1 to 9.3 in the geothermal waters. They clearly predominated under alkaline conditions (up to 83% of total arsenic), but monothioarsenate also was detected in acidic waters (up to 34%). Kinetic studies along a drainage channel showed the importance of thioarsenates for the fate of arsenic discharged from the sulfidic hot spring. The observed arsenic speciation changes suggest three separate reactions: the transformation of trithioarsenate to arsenite (major initial reaction), the stepwise ligand exchange from tri- via di- and monothioarsenate to arsenate (minor reaction), and the oxidation of arsenite to arsenate, which only becomes quantitatively important after thioarsenates have disappeared.

Wyoming↗

USGS1964

The Water Supply of El Morro National Monument

In the land of enchantment, between Gallup and Grants, N. Mex., near the Zuni Mountains, a huge sandstone bluff rises abruptly 200 feet above the plain. The Spaniards called it 'El Morro,' which means 'the headland' or 'bluff.' Around it are other mesas and canyons and stands of pinon and ponderosa pine. Other great rocks are nearby, but none are as popular as El Morro, and none have been as important to the traveler. For at El Morro there is water. In that country, water is scarce and precious. In the old days, travelers from Santa Fe would tell each other about the pool of clear, refreshing water at the base of the huge rock. This is the story of the great bluff, its water supply, and the rocks around it. In the late summer of 1849, an American lieutenant of the Topographical Engineers, James H. Simpson, accompanied infantry and artillery troops on a reconnaissance march from Santa Fe into the Navajo Country. On September 18, at the urging of one Mr. Lewis, an Indian trader, Lieutenant Simpson left the main party in order to see 'half an acre of inscriptions' upon a huge rock (fig. 1) . Although somewhat dubious, the Lieutenant had allowed himself to be persuaded by Lewis that the trip was worthwhile. Taking with him an artist named R. H. Kern, another man by the name of Bird, and Mr. Lewis as guide, he set off through miles of desert country, filled with huge red and white sandstone rocks, 'some of them looking like steamboats, and others presenting very much the appearance of facades of heavy Egyptian architecture'.

Water Supply Paper↗

USGS2005

Disparate effects of constant and annually-cycling daylength and water temperature on reproductive maturation of striped bass (Morone saxatilis)

Adult striped bass ( Morone saxatilis ) were exposed to various combinations of constant or anually-cycling daylength and water temperature. Constant conditions (15 h days, 18 °C) were those normally experienced at spawning and cycling conditions simulated natural changes at Chesapeake Bay latitude. Females exposed to constant long (15 h) days and cycling water temperature (TEMPERATURE group) had blood plasma levels of sex steroids (testosterone [T] and estradiol-17β [E 2 ]) and vitellogenin (Vg), and profiles of oocyte growth, that were nearly identical to those of females held under a natural photothermal cycle (CONTROL group). Several fish from these two groups were induced to spawn fertile eggs. Females constantly exposed to warm water (18 °C), with or without a natural photoperiod cycle (PHOTOPERIOD and STATIC groups, respectively), had diminished circulating levels of gonadal steroid hormones and Vg, impaired deposition of yolk granules in their ooplasm, and decreased oocyte growth, and they underwent premature ovarian atresia. Males exposed to cycling water temperature (CONTROL and TEMPERATURE groups) spermiated synchronously during the natural breeding season, at which time they also had had high plasma androgen (T and 11-ketotestosterone [11-KT]) levels. The timing of spermiation was highly asynchronous among males in groups of fish held constantly at 18 °C (STATIC and PHOTOPERIOD groups) and this asynchrony was associated with diminished plasma androgen levels. Termination of spermiation by males exposed to cycling water temperature coincided with a sharp decline in levels of plasma androgens about a month after water temperature rose above 18 °C. In contrast, most males held constantly at 18 °C sustained intermediate levels of plasma androgens and spermiated until the end of the study in late July. The annual cycle of water temperature clearly plays a prominent role in the initiation, maintenance, and termination of the striped bass reproductive cycle. In females, a decrease in water temperature below values experienced at spawning appears to be required for vitellogenesis and oocyte growth to proceed normally. Constant exposure of males to spawning temperature disrupts synchronous spermiation but also delays testicular regression, which may be useful for spawning fish after the natural reproductive season.

Aquaculture↗

USGS1991

A vacuum-operated pore-water extractor for estuarine and freshwater sediments

A vacuum-operated pore-water extractor for estuarine and freshwater sediments was developed and constructed from a fused-glass air stone attached with aquarium airline tubing to a 30 or 60 cc polypropylene syringe. Pore water is extracted by inserting the air stone into the sediment and creating a vacuum by retracting and bracing the syringe plunger. A hand-operated vacuum pump attached to a filtration flask was also evaluated as an alternative vacuum source. The volume and time to extract pore water varies with the number of devices and the sediment particle size. Extraction time is longer for fine sediments than for sandy sediments. Four liters of sediment generally yield between 500 and 1,500 mL of pore water. The sediment that surrounds and accumulates on the air stone acts as a filter, and, except for the first few milliliters, the collected pore water is clear. Because there is no exposure to air or avenue for escape, volatile compounds andin situ characteristics are retained in the extracted pore water.

Archives of Environmental Contamination and Toxico↗

USGS2016

Transport and deposition of asbestos-rich sediment in the Sumas River, Whatcom County, Washington

Heavy sediment loads in the Sumas River of Whatcom County, Washington, increase seasonal turbidity and cause locally acute sedimentation. Most sediment in the Sumas River is derived from a deep-seated landslide of serpentinite that is located on Sumas Mountain and drained by Swift Creek, a tributary to the Sumas River. This mafic sediment contains high amounts of naturally occurring asbestiform chrysotile. A known human-health hazard, asbestiform chrysotile comprises 0.25–37 percent, by mass, of the total suspended sediment sampled from the Sumas River as part of this study, which included part of water year 2011 and all of water years 2012 and 2013. The suspended-sediment load in the Sumas River at South Pass Road, 0.6 kilometers (km) downstream of the confluence with Swift Creek, was 22,000 tonnes (t) in water year 2012 and 49,000 t in water year 2013. The suspended‑sediment load at Telegraph Road, 18.8 km downstream of the Swift Creek confluence, was 22,000 t in water year 2012 and 27,000 t in water year 2013. Although hydrologic conditions during the study were wetter than normal overall, the 2-year flood peak was only modestly exceeded in water years 2011 and 2013; runoff‑driven geomorphic disturbance to the watershed, which might have involved mass wasting from the landslide, seemed unexceptional. In water year 2012, flood peaks were modest, and the annual streamflow was normal. The fact that suspended-sediment loads in water year 2012 were equivalent at sites 0.6 and 18.8 km downstream of the sediment source indicates that the conservation of suspended‑sediment load can occur under normal hydrologic conditions. The substantial decrease in suspended-sediment load in the downstream direction in water year 2013 was attributed to either sedimentation in the intervening river reach, transfer to bedload as an alternate mode of sediment transport, or both. The sediment in the Sumas River is distinct from sediment in most other river systems because of the large percentage of asbestiform chrysotile in suspension. The suspended sediment carried by the Sumas River consists of three major components: (1) a relatively dense, largely non-flocculated material that settles rapidly out of suspension; (2) a lighter component containing relatively high proportions of flocculated material, much of it composed of asbestiform chrysotile; and (3) individual chrysotile fibers that are too small to flocculate or settle out, and remain in suspension as wash load (these fibers are on the order of microns in length and tenths of microns in diameter). Whereas the bulk density of the first (heaviest) component of suspended sediment was between 1.5 and 1.6 grams per cubic centimeter (g/cm3), the bulk density of the flocculated material was an order of magnitude lower (0.16 g/cm3), even after 24 hours of settling. Soon after immersion in water, the fresh chrysotile fibers derived from the Swift Creek landslide seem to flocculate readily into large bundles, or floccules, that exhibit settling velocities characteristic of coarse silts and fine sands (30 and 250 micrometers). In quiescent water within this river system, the floccules settle out quickly, but still leave between 2.4 and 19.5 million chrysotile fibers per liter in the clear overlying water. Consistent with the results from previous laboratory research, the amounts of asbestiform chrysotile in the water column in Swift Creek, as well as in the Sumas River close to and downstream of its confluence with Swift Creek, were determined to be directly correlated with pH. This observation offers a possible alternative to either turbidity or suspended‑sediment concentration as a surrogate for the concentration of fresh asbestiform chrysotile in suspension. Continued movement and associated erosion of the landslide through mass wasting and runoff will maintain large sediment loads in Swift Creek and in the Sumas River for the foreseeable future. Given the present channel morphology of the river system, aggradation (that is, sediment accumulation) in Swift Creek and the Sumas River are also likely to continue.

Washington↗

USGS2023

Quantifying ecosystem states and state transitions of the Upper Mississippi River System using topological data analysis

Aquatic systems worldwide can exist in multiple ecosystem states (i.e., a recurring collection of biological and chemical attributes), and effectively characterizing multidimensionality will aid protection of desirable states and guide rehabilitation. The Upper Mississippi River System is composed of a large floodplain river system spanning 2200 km and multiple federal, state, tribal and local governmental units. Multiple ecosystem states may occur within the system, and characterization of the variables that define these ecosystem states could guide river rehabilitation. We coupled a long-term (30-year) highly dimensional water quality monitoring dataset with multiple topological data analysis (TDA) techniques to classify ecosystem states, identify state variables, and detect state transitions over 30 years in the river to guide conservation. Across the entire system, TDA identified five ecosystem states. State 1 was characterized by exceptionally clear, clean, and cold-water conditions typical of winter (i.e., a clear-water state); State 2 had the greatest range of environmental conditions and contained most the data (i.e., a status-quo state); and States 3, 4, and 5 had extremely high concentrations of suspended solids (i.e., turbid states, with State 5 as the most turbid). The TDA mapped clear patterns of the ecosystem states across several riverine navigation reaches and seasons that furthered ecological understanding. State variables were identified as suspended solids, chlorophyll a , and total phosphorus, which are also state variables of shallow lakes worldwide. The TDA change detection function showed short-term state transitions based on seasonality and episodic events, and provided evidence of gradual, long-term changes due to water quality improvements over three decades. These results can inform decision making and guide actions for regulatory and restoration agencies by assessing the status and trends of this important river and provide quantitative targets for state variables. The TDA change detection function may serve as a new tool for predicting the vulnerability to undesirable state transitions in this system and other ecosystems with sufficient data. Coupling ecosystem state concepts and TDA tools can be transferred to any ecosystem with large data to help classify states and understand their vulnerability to state transitions.

PLOS Computational Biology↗

USGS2013

Geochemical and isotopic variations in shallow groundwater in areas of the Fayetteville Shale development, north-central Arkansas

Exploration of unconventional natural gas reservoirs such as impermeable shale basins through the use of horizontal drilling and hydraulic fracturing has changed the energy landscape in the USA providing a vast new energy source. The accelerated production of natural gas has triggered a debate concerning the safety and possible environmental impacts of these operations. This study investigates one of the critical aspects of the environmental effects; the possible degradation of water quality in shallow aquifers overlying producing shale formations. The geochemistry of domestic groundwater wells was investigated in aquifers overlying the Fayetteville Shale in north-central Arkansas, where approximately 4000 wells have been drilled since 2004 to extract unconventional natural gas. Monitoring was performed on 127 drinking water wells and the geochemistry of major ions, trace metals, CH 4 gas content and its C isotopes (δ 13 C CH4 ), and select isotope tracers (δ 11 B, 87 Sr/ 86 Sr, δ 2 H, δ 18 O, δ 13 C DIC ) compared to the composition of flowback-water samples directly from Fayetteville Shale gas wells. Dissolved CH 4 was detected in 63% of the drinking-water wells (32 of 51 samples), but only six wells exceeded concentrations of 0.5 mg CH 4 /L. The δ 13 C CH4 of dissolved CH 4 ranged from −42.3&permil; to −74.7&permil;, with the most negative values characteristic of a biogenic source also associated with the highest observed CH 4 concentrations, with a possible minor contribution of trace amounts of thermogenic CH 4 . The majority of these values are distinct from the reported thermogenic composition of the Fayetteville Shale gas (δ 13 C CH4 = −35.4&permil; to −41.9&permil;). Based on major element chemistry, four shallow groundwater types were identified: (1) low (<100 mg/L) total dissolved solids (TDS), (2) TDS > 100 mg/L and Ca–HCO 3 dominated, (3) TDS > 100 mg/L and Na–HCO 3 dominated, and (4) slightly saline groundwater with TDS > 100 mg/L and Cl > 20 mg/L with elevated Br/Cl ratios (>0.001). The Sr ( 87 Sr/ 86 Sr = 0.7097–0.7166), C (δ 13 C DIC = −21.3&permil; to −4.7&permil;), and B (δ 11 B = 3.9–32.9&permil;) isotopes clearly reflect water–rock interactions within the aquifer rocks, while the stable O and H isotopic composition mimics the local meteoric water composition. Overall, there was a geochemical gradient from low-mineralized recharge water to more evolved Ca–HCO 3 , and higher-mineralized Na–HCO 3 composition generated by a combination of carbonate dissolution, silicate weathering, and reverse base-exchange reactions. The chemical and isotopic compositions of the bulk shallow groundwater samples were distinct from the Na–Cl type Fayetteville flowback/produced waters (TDS &sim;10,000–20,000 mg/L). Yet, the high Br/Cl variations in a small subset of saline shallow groundwater suggest that they were derived from dilution of saline water similar to the brine in the Fayetteville Shale. Nonetheless, no spatial relationship was found between CH 4 and salinity occurrences in shallow drinking water wells with proximity to shale-gas drilling sites. The integration of multiple geochemical and isotopic proxies shows no direct evidence of contamination in shallow drinking-water aquifers associated with natural gas extraction from the Fayetteville Shale.

Applied Geochemistry↗

USGS2019

An importance–satisfaction analysis of trout license holders in Georgia

As anglers become increasingly diverse, fisheries managers are challenged to find ways to satisfy users with divergent preferences while conserving a limited resource on a limited budget. With this management challenge in mind, this study combines previous angler specialization research with an importance–satisfaction analysis (ISA) to aid fisheries managers in better understanding users with divergent preferences. An ISA involves asking stakeholders to simultaneously evaluate the importance of salient attributes of their fishing experience and their satisfaction with those attributes, which allows for graphical depiction of each attribute in one of four quadrants with managerial implications: Concentrate Here, Keep up the Good Work, Possible Overkill, and Low Priority. The data were collected via a mail-administered survey that was sent to 4,000 licensed trout anglers who were residents of Georgia. The anglers were asked to evaluate 10 catch and 7 noncatch attributes as well as answer questions that were used to measure levels of angler specialization. A K -means cluster analysis was used to segment the 469 respondents into three groups based on their specialization level. Analysis of variance (ANOVA) was used to determine whether anglers’ preferences differed by level of specialization. The results revealed that specialization groups differed in the level of importance that they placed on 6 catch and 4 noncatch attributes and in their levels of satisfaction with 5 catch and 2 noncatch attributes. There were also differences among the groups in quadrant placement for both catch and noncatch attributes. The respondents agreed that habitat improvement initiatives, adding new fishable water, and clear signage of regulations were of relatively high importance, with habitat improvement initiatives as the only attribute to fall in the Concentrate Here quadrant for all three clusters. The average responses for importance and satisfaction were highest for the most specialized group and lowest for the least specialized group. Combining segmenting techniques, like cluster analysis with ISA, offers fisheries managers the opportunity to gauge different user groups’ perceptions of salient fishery attributes.

Georgia↗

USGS2019

Temperature–not flow–predicts native fish reproduction with Implications for climate change

Habitat alterations and introduction of nonnative fishes reduced the distributions of the Flannelmouth Sucker Catostomus latipinnis , Bluehead Sucker C. discobolus , and Roundtail Chub Gila robusta to less than 50% of their historical ranges. Climate change models generally predict decreased streamflows and increased water temperatures that may further affect these species. Understanding the effects of flow and water temperature on their life histories should lead to better assessments of climate change impacts on extant populations and more informed management for species conservation. Basinwide larval fish sampling and hatch dates derived from otolith daily increment counts showed that water temperature was the dominant environmental factor cueing reproduction in the upper White River basin, Colorado. Reproduction for all three species began in spring, occurring first at warmer, lower-elevation, downstream locations and progressing upriver to higher elevations as water temperatures increased. Warmer water temperatures in tributaries initiated earlier reproductive activity compared to adjacent cooler main-stem habitat. Presence of larvae in samples and estimated hatch dates demonstrated a distinct, predictable upstream progression of reproduction associated with warming water and clear upstream limits to reproduction for all three species. Larval presence and hatching dates revealed earlier reproductive activity in 2012 than in 2013, driven by lower flow and earlier stream warming. A regression model predicted stream temperature during fish spawning seasons under different climate change scenarios and showed expanded upstream limits of thermally suitable reproductive habitat and earlier reproduction for our study species. The long-term implications of climate change are unknown, but managers should strive to perpetuate the valuable and relatively pristine native fish community in the upper White River drainage as a vestige of those that formerly existed throughout the Colorado River basin.

Colorado↗

USGS1998

Evaporation from a small prairie wetland in the Cottonwood Lake area, North Dakota - An energy-budget study

Evaporation from Wetland P1 in the Cottonwood Lake area of North Dakota, USA was determined by the energy-budget method for 1982–85 and 1987. Evaporation rates were as high as 0.672 cm day −1 . Incoming solar radiation, incoming atmospheric radiation, and long-wave radiation emitted from the water body are the largest energy fluxes to and from the wetland. Because of the small heat storage of the water body, evaporation rates closely track solar radiation on short time scales. The effect of advected energy related to precipitation is small because the water quickly heats up by solar radiation following precipitation. Advected energy related to ground water is minimal because ground-water fluxes are small and ground-water temperature is only about 7 °C. Energy flux related to sediment heating and thermal storage in the sediments, which might be expected to be large because the water is clear and shallow, affects evaporation rates by less than 5 percent.

North Dakota↗