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U.S. Geological Survey Integrated Water Availability Assessment—2010–20

This professional paper is a multichapter report that assesses water availability in the United States for water years 2010–20. This work was conducted as part of the fulfillment of the mandates of Subtitle F of the Omnibus Public Land Management Act of 2009 (Public Law 111-11), also known as the SECURE Water Act. As such, this work examines the spatial and temporal distribution of water quantity and quality in surface water and groundwater, as related to human and ecosystem needs and as affected by human and natural influences. Chapter A introduces the National Integrated Water Availability Assessment and provides important background and definitions for how the report characterizes water availability and its components. Chapter A also presents the key findings of Chapters B–F and thus acts as a summary of the entire report. Chapter B is a national assessment of water supply, which is the quantity of water supplied through climatic inputs. Chapter C is a national assessment of water quality, which is the chemical and physical characteristics of water. Chapter D assesses water use including withdrawals and consumptive use in the conterminous United States. Chapter E presents an analysis of factors affecting future water availability under changing climate conditions. The National Integrated Water Availability Assessment culminates with Chapter F, which is an integrated assessment of water availability that considers the amount and quality of water coupled with the suitability of that water for specific uses. Together, these six chapters constitute the National Integrated Water Availability Assessment for water years 2010–20.

Professional Paper↗

Geology of the Southern Guadalupe Mountains, Texas

This report deals with an area of 425 square miles in the western part of Texas, immediately south of the New Mexico line. The area comprises the south end of the Guadalupe Mountains and the adjacent part of the Delaware Mountains; it includes the highest peaks in the State of Texas. The area is a segment of a large mountain mass that extends 50 miles or more northward and southward. The report describes the geology of the area, that is, the nature of its rocks, tectonics, and surface features, and the evidence that they give as to the evolution of the area through geologic time. Incidental reference is made to the geology of surrounding regions in order to place the area in its environment. The Permian system of the southwestern United States has been until recently one of the intriguing but little known subjects of American stratigraphy. In the latter half of the nineteenth century after the western. United States was settled, the "red bed" sections of the Permian were studied and reported on by many geologists, but up to 1920 the existence of a contemporaneous marine sequence in western Texas and southeastern New Mexico was little appreciated. Since that year the discovery of extensive oil fields and potash beds in this region gave an impetus to the study of the Permian rocks, and furnished the geologist with records of hundreds of drill holes from which to deduce the nature of the strata not exposed at the surface. At the same time geologists have studied the rocks in the outcropping areas, and have compared them with the strata encountered by drilling. Much remains to be done in order to understand the history of Permian time in the region. The physical and chemical conditions that caused. the deposition of .the various and often complexly related deposits need to be better understood. More of the fossils of the rich and interesting marine faunas should be described, and the relations of the fossils to their environments should be determined. Further, a satisfactory scheme of correlation is needed, and also a subdivision into series that will express the contemporaneity of strata in different areas. One useful contribution to the solution of these problems is the detailed study of sequences of rocks exposed at the surface in the different mountain ranges of Texas and New Mexico. This report deals with one such sequence of rocks in western Texas, the one exposed in the southern Guadalupe Mountains (fig. 1). Here, the Permian rocks are magnificently exposed, to a thickness of about 4,000 feet (pl. 1). They are all of marine origin, and belong to the middle part of the system, with the base concealed and the top absent. Overlying and underlying beds, however, are found in nearby areas.

Texas↗

Summary appraisals of the nation's ground-water resources – Tennessee region

Ground water is an abundant and little-used resource in the Tennessee Region, a 41,000 square mile area dominated by the Tennessee River system and including parts of Alabama, Georgia, Kentucky, Mississippi, North Carolina, Tennessee, and Virginia. One-fifth to one-fourth of the precipitation that falls on the region enters the ground-water reservoirs. During the year approximately the same amount of water leaves the ground-water system, sustaining the dry-weather flow of streams. Recharge for the region is about 22,000 million gallons per day or 0.5 million gallons per day per square mile. The major types of aquifers in the region are unconsolidated material (including sand and regolith), carbonate rocks, and fractured noncarbonate rocks. One or more of these aquifer types occurs in each of the six physiographic subdivisions of the region. The productivity of these aquifers depends on their hydraulic properties and on the distribution of these properties. The unconsolidated sand aquifers are the most homogeneous in composition and most predictable in occurrence. These aquifers commonly yield 200 to 600 gallons per minute per well depending on the thickness of sand penetrated. The most difficult aquifers to predict in regard to depth and yield are the carbonate rocks. In these aquifers it is possible to drill dry holes within a few hundred feet of wells capable of producing several thousand gallons per minute. However, with an adequate reconnaissance study to determine the occurrence of ground water and a planned test drilling program, yields of up to 300 gallons per minute per well can be expected in the carbonate aquifers. Potential yields from the fractured noncarbonate aquifers are lower than in the carbonate rocks. The chemical and physical properties of ground water in the Tennessee Region are usually within the limits recommended by the Environmental Protection Agency for drinking water, and the ground water in all but some very shallow aquifers tends to be free of pathogenic microorganisms. Saline water is not known to occur in significant quantities in the region. In 1970, 173 million gallons per day of ground water were used in the Tennessee Region. This was less than 8 percent of the total quantity of water used in the region and only 0.8 percent of the estimated ground-water recharge. Ground water is used chiefly as a source of water supply for rural areas and small towns. A lesser amount is used by industries and commercial establishments located beyond the limits of municipal water-supply systems. However, there is potential for significantly increased use in order to augment surface-water supplies and to utilize the total water resource more efficiently. Hydrologic studies and adequate test drilling would greatly increase the chances of locating large amounts of ground water, especially in the nine-tenths of the Tennessee Region that is underlain by either carbonate rocks or fractured noncarbonate rocks which have highly variable water-bearing properties. Collectively, such studies are useful in developing a concept of the hydrologic system which would permit the development of criteria for selecting well sites in other areas with a similar geological and hydrological setting. Hydrologic studies that include test drilling have been conducted in all parts of the region except the Cumberland Plateau. Some of the basic data necessary for hydrologic studies, such as geologic maps, well records, and streamflow records are available throughout the region. However, detailed information on groundwater levels, ground-water quality, and aquifer characteristics are not equally available throughout the region. This type of information cannot be obtained quickly when it is needed; it must be the product of a continuing program of studies designed to evaluate the Tennessee Region's ground-water resource. Because of the interdependence of ground water and surface water, water management efforts can be fully effective only if they involve the whole water resource. In the Tennessee Region, surface water is highly controlled, but there is at present no regionwide water-resources management plan that includes ground water.

Tennessee↗

Summary appraisals of the nation's ground-water resources– South Atlantic-Gulf region

Precipitation in the 270,000-square-mile South Atlantic-Gulf Region ranges from 44 to 80 inches, and the average runoff is about 15 inches. The ground-water discharge that forms the base flow of streams is conservatively estimated to be about 78,000 million gallons per day the equivalent of about 6 inches of precipitation. On this basis, the regional sustained ground-water supply is about 286,000 gallons per day per square mile. Projected water use through 2020 indicates that about 10 percent of the supply will meet the region's requirement for ground water. Enormous quantities of ground water are available in the South Atlantic-Gulf States in the extensive aquifers that underlie the Coastal Plain province. Large supplies of ground water can be developed also in places in the Cumberland Plateau and the Valley and Ridge provinces. In the Piedmont and Blue Ridge provinces ground water is available only in modest quantities. The principal Coastal Plain aquifers consist largely of deltaic sand and gravel deposits of Cretaceous to Quaternary age; however, a notable exception is the highly permeable Tertiary limestone aquifer, which underlies parts of four States. Ground water in the Blue Ridge and the Valley and Ridge provinces is available from openings along fissures and joints in consolidated rocks and from the unconsolidated sand and gravel in the residuum and alluvium that overlie the bedrock. In parts of these areas faulting and folding has created favorable conditions for the development of moderate supplies of ground water. In the Piedmont province modest quantities of water are available from joints and fractures. Solution cavities in massive limestone units in some areas underlying the Cumberland Plateau section yield very large quantities of ground water. Most of the major Coastal Plain aquifers are recharged where they are exposed and water moves downdip to the south. The general direction of ground-water movement in the Coastal Plain aquifers is seaward. There is, however, movement of water vertically and laterally that affects pressure and quality in every aquifer. Ground water of good chemical and physical quality is available generally except in a small area in western Alabama and eastern Mississippi and in some small coastal areas. Freshwater extends to depths of slightly more than 3,000 feet in some areas. In many areas, water can be produced that does not require any treatment for general use. The more common objectionable constituents or properties are excessive iron, fluoride, hardness, color, and acidity. Contamination or pollution of ground water is not a major regional problem, but it is significant in local areas. Many of these local problems of contamination were the result of earlier improper disposal of oil-field and industrial waste. Saltwater intrusion either directly from the sea or from estuaries has been reported in every State in the region, and the potential for the proliferation of this problem is very large. The relationship of ground water and surface water is significant at many places in the region where large ground-water withdrawals affect swamps, lakes, and the flow of streams and springs. There is a potential in some areas for using ground water during dry periods for low-flow augmentation of stream supplies. In other areas it is feasible to recharge ground-water reservoirs artificially by means of injection wells, pits, and water spreading. Although large water-level declines caused by withdrawals have occurred locally, water-level changes have been small or modest when considered on a regional basis owing to the abundant rainfall and favorable recharge conditions. The saline-water resources of the region are known to be extremely large. In some areas where the availability of freshwater is limited, saline ground water is available for desalinization to supplement freshwater supplies. Also, the saline aquifers are potential storage sites for injected freshwater. Ground-water problems generally are not severe. Critical situations are restricted to areas where large quantities of ground water are being withdrawn or where aquifers are contaminated by oil-field or industrial waste. Large withdrawals in coastal areas have caused some saltwater intrusion. In other localities, highly mineralized water may have migrated along fault zones to freshwater aquifers. Many of the present problems can be resolved or ameliorated by redistributing withdrawals or developing alternative water sources.

Alabama, Florida, Georgia, Mississippi, North Caro↗

Effects of changes in reservoir operations on water quality and trophic state indicators in Voyageurs National Park, northern Minnesota, 2001-03

Implementation of an order by the International Joint Commission in January 2000 has changed operating procedures for dams that regulate two large reservoirs in Voyageurs National Park in northern Minnesota. These new procedures were expected to restore a more natural water regime and affect water levels, water quality, and trophic status. Results of laboratory analyses and field measurements of chemical and physical properties from May 2001 through September 2003 were compared to similar data collected prior to the change in operating procedures. Rank sum tests showed significant decreases in chlorophyll-a concentrations and trophic state indices for Kabetogama Lake (p=0.021) and Black Bay (p=0.007). There were no significant decreases in total phosphorus concentration, however, perhaps due to internal cycling of phosphorus. No sites had significant trends in seasonal total phosphorus concentrations, with the exception of May samples from Sand Point Lake, which had a significant decreasing trend (tau=-0.056, probability=0.03). May chlorophyll-a concentrations for Kabetogama Lake showed a significant decreasing trend (tau=-0.42, probability=0.05). Based on mean chlorophyll trophic-state indices (2001-03), Sand Point, Namakan, and Rainy Lakes would be classified oligotrophic to mesotrophic, and Kabetogama Lake and Rainy Lake at Black Bay would be classified as mesotrophic. The classification of Sand Point, Namakan, and Rainy Lakes remain the same for data collected prior to the change in operating procedures. In contrast, the trophic classification of Kabetogama Lake and Rainy Lake at Black Bay has changed from eutrophic to mesotrophic.

Minnesota↗

Water quality of Nippersink Creek and Wonder Lake, McHenry County, Illinois, 1994-2001

Wonder Lake, McHenry County, Illinois was formed when an earthen dam was constructed across Nippersink Creek in 1929. The U.S. Geological Survey (USGS), in cooperation with the McHenry County Soil and Water Conservation District, operated two streamflow and water-quality monitoring sites (upstream and downstream of Wonder Lake) from July 1994 through June 1997, and examined the water quality of the lake during 1999-2000. From 1999 through 2001, the USGS National Water-Quality Assessment Program operated the same upstream monitoring station to assess the streamflow, sediments, nutrients, and other chemical and physical characteristics of Nippersink Creek. Interpolation and regression methods were used to compute loads of sediment and nutrients delivered to Wonder Lake through Nippersink Creek by the combination of data sets collected as part of these studies. Since the formation of Wonder Lake, sediment and nutrient loading from Nippersink Creek has caused lake water-quality degradation. Wonder Lake effectively trapped 75 percent of the 15,900 tons of suspended sediment delivered during 1994-97. The average daily sediment load delivered during 1994-2001 was 25 tons. High sediment loading from the watershed reduces water clarity and hinders lake navigation. Nutrient loading from Nippersink Creek results in eutrophic conditions within Wonder Lake as evaluated on a Trophic State Index. The load of total phosphorus trapped in Wonder Lake is from 6 to 28 percent of the delivered load from Nippersink Creek. If the lake could be restored to its original capacity, the sediment trapping efficiency may be increased.

Scientific Investigations Report↗

Vertical distribution of trace-element concentrations and occurrence of metallurgical slag particles in accumulated bed sediments of Lake Roosevelt, Washington, September 2002

Sediment cores were collected from six locations in Lake Roosevelt to determine the vertical distributions of trace-element concentrations in the accumulated sediments of Lake Roosevelt. Elevated concentrations of arsenic, cadmium, copper, lead, mercury, and zinc occurred throughout much of the accumulated sediments. Concentrations varied greatly within the sediment core profiles, often covering a range of 5 to 10 fold. Trace-element concentrations typically were largest below the surficial sediments in the lower one-half of each profile, with generally decreasing concentrations from the 1964 horizon to the surface of the core. The trace-element profiles reflect changes in historical discharges of trace elements to the Columbia River by an upstream smelter. All samples analyzed exceeded clean-up guidelines adopted by the Confederated Tribes of the Colville Reservation for cadmium, lead, and zinc and more than 70 percent of the samples exceeded cleanup guidelines for mercury, arsenic, and copper. Although 100 percent of the samples exceeded sediment guidelines for cadmium, lead, and zinc, surficial concentrations of arsenic, copper, and mercury in some cores were less than the sediment-quality guidelines. With the exception of copper, the trace-element profiles of the five cores collected along the pre-reservoir Columbia River channel typically showed trends of decreasing concentrations in sediments deposited after the 1964 time horizon. The decreasing concentrations of trace elements in the upper half of cores from along the pre-reservoir Columbia River showed a pattern of decreasing concentrations similar to reductions in trace-element loading in liquid effluent from an upstream smelter. Except for arsenic, trace-element concentrations typically were smaller at downstream reservoir locations along the pre-reservoir Columbia River. Trace-element concentration in sediments from the Spokane Arm of the reservoir showed distinct differences compared to the similarities observed in cores from along the pre-reservoir Columbia River. Particles of slag, which have physical and chemical characteristics of slag discharged to the Columbia River by a lead-zinc smelter upstream of the reservoir at Trail, British Columbia, were found in sediments of Lake Roosevelt. Slag particles are more common in the upstream reaches of the reservoir. The chemical composition of the interior matrix of slag collected from Lake Roosevelt closely approximated the reported elemental concentrations of fresh smelter slag, although evidence of slag weathering was observed. Exfoliation flakes were observed on the surface of weathered slag particles isolated from the core sediments. The concentrations of zinc on the exposed surface of slag grains were smaller than concentrations on interior surfaces. Weathering rinds also were observed in the cross section of weathered slag grains, indicating that the glassy slag material was undergoing hydration and chemical weathering. Trace elements observed in accumulated sediments in the middle and lower reaches of the reservoir are more likely due to the input from liquid effluent discharges compared to slag discharges from the upstream smelter.

Scientific Investigations Report↗

Characterization and modes of occurrence of elements in feed coal and coal combustion products from a power plant utilizing low-sulfur coal from the Powder River Basin, Wyoming

The U.S. Geological Survey and the University of Kentucky Center for Applied Energy Research are collaborating with an Indiana utility company to determine the physical and chemical properties of feed coal and coal combustion products from a coal-fired power plant. The Indiana power plant utilizes a low-sulfur (0.23 to 0.47 weight percent S) and lowash (4.9 to 6.3 weight percent ash) subbituminous coal from the Wyodak-Anderson coal zone in the Tongue River Member of the Paleocene Fort Union Formation, Powder River Basin, Wyoming. Based on scanning electron microscope and X-ray diffraction analyses of feed coal samples, two mineral suites were identified: (1) a primary or detrital suite consisting of quartz (including beta-form grains), biotite, feldspar, and minor zircon; and (2) a secondary authigenic mineral suite containing alumino-phosphates (crandallite and gorceixite), kaolinite, carbonates (calcite and dolomite), quartz, anatase, barite, and pyrite. The primary mineral suite is interpreted, in part, to be of volcanic origin, whereas the authigenic mineral suite is interpreted, in part, to be the result of the alteration of the volcanic minerals. The mineral suites have contributed to the higher amounts of barium, calcium, magnesium, phosphorus, sodium, strontium, and titanium in the Powder River Basin feed coals in comparison to eastern coals. X-ray diffraction analysis indicates that (1) fly ash is mostly aluminate glass, perovskite, lime, gehlenite, quartz, and phosphates with minor amounts of periclase, anhydrite, hematite, and spinel group minerals; and (2) bottom ash is predominantly quartz, plagioclase (albite and anorthite), pyroxene (augite and fassaite), rhodonite, and akermanite, and spinel group minerals. Microprobe and scanning electron microscope analyses of fly ash samples revealed quartz, zircon, and monazite, euhedral laths of corundum with merrillite, hematite, dendritic spinels/ferrites, wollastonite, and periclase. The abundant calcium and magnesium mineral phases in the fly ash are attributed to the presence of carbonate, clay, and phosphate minerals in the feed coal and their alteration to new phases during combustion. The amorphous diffraction-scattering maxima or glass 'hump' appears to reflect differences in chemical composition of fly ash and bottom ash glasses. In Wyodak-Anderson fly and bottom ashes, the center point of scattering maxima is due to calcium and magnesium content, whereas the glass 'hump' of eastern fly ash reflects variation in aluminum content. The calcium- and magnesium-rich and alumino-phosphate mineral phases in the coal combustion products can be attributed to volcanic minerals deposited in peat-forming mires. Dissolution and alteration of these detrital volcanic minerals occurred either in the peat-forming stage or during coalification and diagenesis, resulting in the authigenic mineral suite. The presence of free lime (CaO) in fly ash produced from Wyodak-Anderson coal acts as a self-contained 'scrubber' for SO3, where CaO + SO3 form anhydrite either during combustion or in the upper parts of the boiler. Considering the high lime content in the fly ash and the resulting hydration reactions after its contact with water, there is little evidence that major amounts of leachable metals are mobilized in the disposal or utilization of this fly ash.

Scientific Investigations Report↗

Response curves for phosphorus plume lengths from reactive-solute-transport simulations of onland disposal of wastewater in noncarbonate sand and gravel aquifers

Surface-water resources in Massachusetts often are affected by eutrophication, excessive plant growth, which has resulted in impaired use for a majority of the freshwater ponds and lakes and a substantial number of river-miles in the State. Because supply of phosphorus usually is limiting to plant growth in freshwater systems, control of phosphorus input to surface waters is critical to solving the impairment problem. Wastewater is a substantial source of phosphorus for surface water, and removal of phosphorus before disposal may be necessary. Wastewater disposed onland by infiltration loses phosphorus from the dissolved phase during transport through the subsurface and may be an effective disposal method; quantification of the phosphorus loss can be simulated to determine disposal feasibility. In 2003, the U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, initiated a project to simulate distance of phosphorus transport in the subsurface for plausible conditions of onland wastewater disposal and subsurface properties. A coupled one-dimensional unsaturated-zone and three-dimensional saturated-zone reactive-solute-transport model (PHAST) was used to simulate lengths of phosphorus plumes. Knowledge of phosphorus plume length could facilitate estimates of setback distances for wastewater-infiltration sites from surface water that would be sufficient to protect the surface water from eutrophication caused by phosphorus transport through the subsurface and ultimate discharge to surface water. The reactive-solute-transport model PHAST was used to simulate ground-water flow, solute transport, equilibrium chemistry for dissolved and sorbed species, and kinetic regulation of organic carbon decomposition and phosphate mineral formation. The phosphorus plume length was defined for the simulations as the maximum extent of the contour for the 0.015 milligram-per-liter concentration of dissolved phosphorus downgradient from the infiltration bed after disposal cessation. Duration of disposal before cessation was assumed to be 50 years into an infiltration bed of 20,000 square feet at the rate of 3 gallons per square foot per day. Time for the maximum extent of the phosphorus plume to develop is on the order of 100 years after disposal cessation. Simulations indicated that phosphorus transport beyond the extent of the 0.015 milligram-per-liter concentration contour was never more than 0.18 kilogram per year, an amount that would likely not alter the ecology of most surface water. Simulations of phosphorus plume lengths were summarized in a series of response curves. Simulated plume lengths ranged from 200 feet for low phosphorus-concentration effluents (0.25 milligram per liter) and thick (50 feet) unsaturated zones to 3,400 feet for high phosphorus-concentration effluents (14 milligrams per liter) discharged directly into the aquifer (unsaturated-zone thickness of 0 feet). Plume length was nearly independent of unsaturated-zone thickness at phosphorus concentrations in the wastewater that were less than 2 milligrams per liter because little or no phosphorus mineral formed at low phosphorus concentrations. For effluents of high phosphorus concentration, plume length varied from 3,400 feet for unsaturated-zone thickness of 0 to 2,550 feet for unsaturated-zone thickness of 50 feet. Model treatments of flow and equilibrium-controlled chemistry likely were more accurate than rates of kinetically controlled reactions, notably precipitation of iron-phosphate minerals; the kinetics of such reactions are less well known and thus less well defined in the model. Sensitivity analysis indicated that many chemical and physical aquifer properties, such as hydraulic gradient and model width, did not affect the simulated plume length appreciably, but duration of discharge, size of infiltration bed, amount of dispersion, and number of sorption sites on the aquifer sediments did affect plume length appreciably. Because simulation of plume length in carbonate-mineral sediments indicated that the plume would be substantially longer than in noncarbonate-mineral sediments, the application of the response curves in locations with carbonate-mineral sediments would be inappropriate. The effect of carbonate minerals in sediments is to increase pH, which causes decreased sorption of phosphorus on aquifer sediments. Phosphorus removal from solution by precipitation onto aquifer sediments is more efficient at high concentrations of disposed phosphorus than at low concentrations. At very low phosphorus concentrations, the solubility product of phosphorus minerals is not exceeded and no phosphorus mineral forms. An important consequence is that removal of dissolved phosphorus from the plume by processes in the subsurface is decreased the more that removal efforts are applied in treatment before wastewater is disposed. Model simulations indicate that removal of phosphorus from wastewater disposed through septic systems would have the advantage of efficient phosphorus removal in the subsurface because phosphorus concentrations are high in septic-system effluent. Short plume lengths result from wastewater disposal through septic systems because of the efficient phosphorus removal and because of the low volume of wastewater involved. The simulation results for small-volume systems are not quantitative, however, because wastewater-infiltration rates are much lower than those of the higher-volume system that was used to calibrate the model and to create the plume-length response curves. The response curves for phosphorus plume lengths, as defined by the maximum extent of the 0.015 milligram-per-liter concentration contour, is clearly defined in the model simulations, although the relation between simulated plume length and protective setback distance is subject to interpretation. Phosphorus does move beyond the point at which the simulated 0.015 milligram-per-liter concentration contour has stopped, so that a determination of protective setback distance must include a consideration of whether that continued flux, or some other flux amount, is appropriate. Also, simulations indicate that phosphorus plumes do not reach their full extent until 50 to 200 years after disposal cessation, depending on concentration of phosphorus disposed. No phosphorus plume has been monitored for that long after cessation, so there is no way to verify the long-term simulation results.

Massachusetts↗

Review of the transport of selected radionuclides in the interim risk assessment for the Radioactive Waste Management Complex, Waste Area Group 7 Operable Unit 7-13/14, Idaho National Engineering and Environmental Laboratory, Idaho

The U.S. Department of Energy (DOE) requested that the U.S. Geological Survey conduct an independent technical review of the Interim Risk Assessment (IRA) and Contaminant Screening for the Waste Area Group 7 (WAG-7) Remedial Investigation, the draft Addendum to the Work Plan for Operable Unit 7-13/14 WAG-7 comprehensive Remedial Investigation and Feasibility Study (RI/FS), and supporting documents that were prepared by Lockheed Martin Idaho Technologies, Inc. The purpose of the technical review was to assess the data and geotechnical approaches that were used to estimate future risks associated with the release of the actinides americium, uranium, neptunium, and plutonium to the Snake River Plain aquifer from wastes buried in pits and trenches at the Subsurface Disposal Area (SDA). The SDA is located at the Radioactive Waste Management Complex in southeastern Idaho within the boundaries of the Idaho National Engineering and Environmental Laboratory. Radionuclides have been buried in pits and trenches at the SDA since 1957 and 1952, respectively. Burial of transuranic wastes was discontinued in 1982. The five specific tasks associated with this review were defined in a ?Proposed Scope of Work? prepared by the DOE, and a follow-up workshop held in June 1998. The specific tasks were (1) to review the radionuclide sampling data to determine how reliable and significant are the reported radionuclide detections and how reliable is the ongoing sampling program, (2) to assess the physical and chemical processes that logically can be invoked to explain true detections, (3) to determine if distribution coefficients that were used in the IRA are reliable and if they have been applied properly, (4) to determine if transport model predictions are technically sound, and (5) to identify issues needing resolution to determine technical adequacy of the risk assessment analysis, and what additional work is required to resolve those issues.

Idaho↗

Radiochemical sampling and analysis of shallow ground water and sediment at the BOMARC Missile Facility, east-central New Jersey, 1999-2000

A field sampling experiment was designed using low-flow purging with a portable pump and sample-collection equipment for the collection of water and sediment samples from observation wells screened in the Kirkwood-Cohansey aquifer system to determine radionuclide or trace-element concentrations for various size fractions. Selected chemical and physical characteristics were determined for water samples from observation wells that had not been purged for years. The sampling was designed to define any particulate, colloidal, and solution-phase associations of radionuclides or trace elements in ground water by means of filtration and ultrafiltration techniques. Turbidity was monitored and allowed to stabilize before samples were collected by means of the low-flow purging technique rather than by the traditional method of purging a fixed volume of water at high-flow rates from the observation well. A minimum of four water samples was collected from each observation well. The samples of water from each well were collected in the following sequence. (1) A raw unfiltered sample was collected within the first minutes of pumping. (2) A raw unfiltered sample was collected after at least three casing volumes of water were removed and turbidity stabilized. (3) A sample was collected after the water was filtered with a 0.45-micron filter. (4) A sample was collected after the water passed through a 0.45-micron filter and a 0.003-micron tangential-flow ultrafilter in sequence. In some cases, a fifth sample was collected after the water passed through a 0.45-micron filter and a 0.05-micron filter in sequence to test for colloids of 0.003 microns to 0.05 microns in size. The samples were analyzed for the concentration of manmade radionuclides plutonium-238 and -239 plus -240, and americium-241. The samples also were analyzed for concentrations of uranium-234, -235, and -238 to determine whether uranium-234 isotope enrichment (resulting from industrial processing) is present. A subset of samples was analyzed for concentrations of thorium-232, -230, and -228 to determine if thorium-228 isotope enrichment, also likely to result from industrial processing, is present. Concentrations of plutonium isotopes and americium-241 in the water samples were less than 0.1 picocurie per liter, the laboratory reporting level for these manmade radionuclides, with the exception of one americium-241 concentration from a filtered sample. A sequential split sample from the same well did not contain a detectable concentration of americium-241, however. Other filtered and unfiltered samples of water from the same well did not contain quantities of americium-241 nearly as high as 0.1 pCi/L. Therefore, the presence of americium-241 in a quantifiable concentration in water samples from this well could not be confirmed. Neither plutonium nor americium was detected in samples of settled sediment collected from the bottom of the wells. Concentrations of uranium isotopes (maximum of 0.05 and 0.08 picocuries per liter of uranium-238 and uranium-234, respectively) were measurable in unfiltered samples of turbid water from one well and in the settled bottom sediment from 6 wells (maximum concentrations of 0.25 and 0.20 picocuries per gram of uranium-238 and uranium-234, respectively). The uranium-234/uranium-238 isotopic ratio was near 1:1, which indicates natural uranium. The analytical results, therefore, indicate that no manmade radionuclide contamination is present in any of the well-bottom sediments, or unfiltered or filtered water samples from any of the sampled wells. No evidence of manmade radionuclide contamination was observed in the aquifer as settled or suspended particulates, colloids, or in the dissolved phase.

New Jersey↗

Questa baseline and pre-mining ground-water quality investigation. 12. Geochemical and reactive-transport modeling based on tracer injection-synoptic sampling studies for the Red River, New Mexico, 2001-2002

Reactive-transport processes in the Red River, downstream from the town of Red River in north-central New Mexico, were simulated using the OTEQ reactive-transport model. The simulations were calibrated using physical and chemical data from synoptic studies conducted during low-flow conditions in August 2001 and during March/April 2002. Discharge over the 20-km reach from the town of Red River to the USGS streamflow-gaging station near the town of Questa ranged from 395 to 1,180 L/s during the 2001 tracer and from 234 to 421 L/s during the 2002 tracer. The pH of the Red River ranged from 7.4 to 8.5 during the 2001 tracer and from 7.1 to 8.7 during the 2002 tracer, and seep and tributary samples had pH values of 2.8 to 9.0 during the 2001 tracer and 3.8 to 7.2 during the 2002 tracer. Mass-loading calculations allowed identification of several specific locations where elevated concentrations of potential contaminants entered the Red River . These locations, characterized by features on the north side of the Red River that are known to be sources of low-pH water containing elevated metal and sulfate concentrations, are: the initial 2.4 km of the study reach, including Bitter Creek, the stream section from 6.2 to 7.8 km, encompassing La Bobita well and the Hansen debris fan, Sulphur Gulch, at about 10.5 km, the area near Portal Springs, from 12.2 to 12.6 km, and the largest contributors of mass loading, the 13.7 to 13.9 km stream section near Cabin Springs and the 14.7 to 17.5 km stream section from Shaft Spring to Thunder Bridge, Goathill Gulch, and Capulin Canyon. Speciation and saturation index calculations indicated that although solubility limits the concentration of aluminum above pH 5.0, at pH values above 7 and aluminum concentrations below 0.3 mg/L inorganic speciation and mineral solubility controls no longer dominate and aluminum-organic complexing may occur. The August 2001 reactive-transport simulations included dissolved iron(II) oxidation, constrained using measured concentrations of dissolved iron(II) and dissolved iron(total). Both simulations included precipitation of amorphous Al(OH) 3 and hydrous ferric oxide as Fe(OH) 3 , and sorption of copper and zinc to the precipitated hydrous ferric oxide. Simulations revealed that hydrogen, iron, aluminum, copper, and zinc were non-conservative and that mineral precipitation can account for iron and aluminum concentrations. Copper and zinc concentrations can be accounted for by simulating their sorption to hydrous ferric oxide forming in the water column of the Red River , although hydrous manganese oxides also may be important sorption substrates.

New Mexico↗

Age and quality of ground water and sources of nitrogen in the surficial aquifers in Pumpkin Creek Valley, western Nebraska, 2000

Ground water is the source of drinking water for the residents of Pumpkin Creek Valley, western Nebraska. In this largely agricultural area, shallow aquifers potentially are susceptible to nitrate contamination. During the last 10 years, ground-water levels in the North Platte Natural Resources District have declined and contamination has become a major problem for the district. In 2000, the U.S. Geological Survey and the North Platte Natural Resources District began a cooperative study to determine the age and quality of the ground water and the sources of nitrogen in the aquifers in Pumpkin Creek Valley. Water samples were collected from 8 surface-water sites, 2 springs, and 88 ground-water sites during May, July, and August 2000. These samples were analyzed for physical properties, nutrients or nitrate, and hydrogen and oxygen isotopes. In addition, a subset of samples was analyzed for any combination of chlorofluorocarbons, tritium, tritium/helium, sulfur-hexafluoride, carbon-14, and nitrogen-15. The apparent age of ground water in the alluvial aquifer typically varied from about 1980 to modern, whereas ground water in the fractured Brule Formation had a median value in the 1970s. The Brule Formation typically contained ground water that ranged from the 1940s to the 1990s, but low-yield wells had apparent ages of 5,000 to 10,000 years before present. Data for oxygen-18 and deuterium indicated that lake-water samples showed the greatest effects from evaporation. Ground-water data showed no substantial evaporative effects and some ground water became isotopically heavier as the water moved downgradient. In addition, the physical and chemical ground-water data indicate that Pumpkin Creek is a gaining stream because little, if any, of its water is lost to the ground-water system. The water-quality type changed from a sodium calcium bicarbonate type near Pumpkin Creek's headwaters to a calcium sodium bicarbonate type near its mouth. Nitrate concentrations were largest in the alluvial system (median = 5 mg/L) and smallest in the surface-water system (median = 1 mg/L). Most nitrate concentrations exceeding the U.S. Environmental Protection Agency maximum contaminant level for drinking water of 10 mg/L as nitrogen were adjacent to irrigated fields and in areas where alluvial sediments are less than 50 ft thick. Sources of nitrogen in the ground water of the study area included naturally occurring nitrogen, commercial fertilizer, and animal waste. Based on nitrate concentration and delta nitrogen-15, the nitrogen in 65 percent of the water samples appears to have originated from a mixture of commercial fertilizers and animal waste. Some of the smallest nitrate concentrations in the ground-water samples contained some of the largest delta nitrogen-15 values (greater than 10 per mil), which suggests animal waste as the likely source. Commercial fertilizers were the likely source of most of the nitrogen in water samples with nitrate concentrations that exceeded 10 mg/L. The source of the nitrogen in water samples with nitrate concentrations exceeding 10 mg/L, but with delta nitrogen-15 values close to 10 per mil, could not be determined.

Nebraska↗

Water resources of Carbon County, Wyoming

Carbon County is located in the south-central part of Wyoming and is the third largest county in the State. A study to describe the physical and chemical characteristics of surface-water and ground-water resources in Carbon County was conducted by the U.S. Geological Survey in cooperation with the Wyoming State Engineer's Office. Evaluations of streamflow and stream-water quality were limited to analyses of historical data and descriptions of previous investigations. Surface-water data were not collected as part of the study. Forty-five ground-water-quality samples were collected as part of the study and the results from an additional 618 historical ground-water-quality samples were reviewed. Available hydrogeologic characteristics for various aquifers in hydrogeologic units throughout the county also are described. Flow characteristics of streams in Carbon County vary substantially depending on regional and local basin char-acteristics and anthropogenic factors. Precipitation in the county is variable with high mountainous areas receiving several times the annual precipitation of basin lowland areas. For this reason, streams with headwaters in mountainous areas generally are perennial, whereas most streams in the county with headwaters in basin lowland areas are ephemeral, flowing only as a result of regional or local rainfall or snowmelt runoff. Flow characteristics of most perennial streams are altered substantially by diversions and regulation. Water-quality characteristics of selected streams in and near Carbon County during water years 1966 through 1986 varied. Concentrations of dissolved constituents and suspended sediment were smallest at sites on streams with headwaters in mountainous areas because of resistant geologic units, large diluting streamflows, and increased vegetative cover compared to sites on streams with headwaters in basin lowlands. Both water-table and artesian conditions occur in aquifers within the county. Shallow ground water is available throughout the county, although much of it is only marginally suitable or is unsuitable for domestic and irrigation uses mainly because of high total dissolved solids (TDS) concentrations. Suitable ground water for livestock use is available in most areas of the county. Ground-water quality tends to deteriorate with increasing distance from recharge areas and with increasing depth below land surface. Ground water from depths greater than a few thousand feet tends to have TDS concentrations that make it moderately saline to briny. In some areas, even shallow ground water is moderately saline. Specific constituents in parts of some aquifers in the county occur in relatively high concentrations when compared to U.S. Environmental Protection Agency drinking-water standards; for example, relatively high concentrations of sulfate, chloride, fluoride, boron, iron, manganese, and radon were found in several aquifers. The estimated mean daily water use in Carbon County in 2000 was about 320 million gallons per day. Water used for irrigation accounted for about 98 percent of this total. About 98 percent of the total water used was supplied by surface water and about 2 percent by ground water. Excluding irrigation, ground water comprised about 78 percent of total water use in Carbon County. Although ground water is used to a much lesser extent than surface water, in many areas of the county it is the only available water source.

Scientific Investigations Report↗

Sediment coring and sedimentation analysis on Rasmussen Lake in Ethel's Woods Forest Preserve near Old Mill Creek, Illinois in 2005

The Lake County Forest Preserve District (LCFPD) is investigating the possibility of modifying the dam on Rasmussen Lake in Ethel's Woods Forest Preserve. The lake is of low water quality with an eroding shoreline. Sediments have been deposited in the impoundment over the last 50 years. Twenty-eight sediment sampling locations were identified along seven transects over a 51.4 acre area in Rasmussen Lake to determine sediment thickness and obtain sediment material for physical and chemical analyses. The maximum sediment thickness was consistently 3.0-4.5 feet (ft) from the dam to the upper end of the lake. The sediment thickness was less than 2.5 ft near the shore and in transect 5, near the northern part of the lake. Sediment thickness did not increase either in the upstream or downstream direction. The average-transect sediment thicknesses ranged from 1.8 to 2.7 ft. The approximate total sediment volume that has accumulated in the 51.4 acres of the lake over the past 50 years is 115.1 acre-feet.

Scientific Investigations Report↗

Simulation of daily pesticide concentrations from watershed characteristics and monthly climatic data

A time-series model was developed to simulate daily pesticide concentrations for streams in the coterminous United States. The model was based on readily available information on pesticide use, climatic variability, and watershed charac-teristics and was used to simulate concentrations for four herbicides [atrazine, ethyldipropylthiocarbamate (EPTC), metolachlor, and trifluralin] and three insecticides (carbofuran, ethoprop, and fonofos) that represent a range of physical and chemical properties, application methods, national application amounts, and areas of use in the United States. The time-series model approximates the probability distributions, seasonal variability, and serial correlation characteristics in daily pesticide concentration data from a national network of monitoring stations. The probability distribution of concentrations for a particular pesticide and station was estimated using the Watershed Regressions for Pesticides (WARP) model. The WARP model, which was developed in previous studies to estimate the probability distribution, was based on selected nationally available watershed-characteristics data, such as pesticide use and soil characteristics. Normality transformations were used to ensure that the annual percentiles for the simulated concentrations agree closely with the percentiles estimated from the WARP model. Seasonal variability in the transformed concentrations was maintained by relating the transformed concentration to precipitation and temperature data from the United States Historical Climatology Network. The monthly precipitation and temperature values were estimated for the centroids of each watershed. Highly significant relations existed between the transformed concentrations, concurrent monthly precipitation, and concurrent and lagged monthly temperature. The relations were consistent among the different pesticides and indicated the transformed concentrations generally increased as precipitation increased but the rate of increase depended on a temperature-dependent growing-season effect. Residual variability of the transformed concentrations, after removal of the effects of precipitation and temperature, was partitioned into a signal (systematic variability that is related from one day to the next) and noise (random variability that is not related from one day to the next). Variograms were used to evaluate measurement error, seasonal variability, and serial correlation of the historical data. The variogram analysis indicated substantial noise resulted, at least in part, from measurement errors (the differences between the actual concen-trations and the laboratory concentrations). The variogram analysis also indicated the presence of a strongly correlated signal, with an exponentially decaying serial correlation function and a correlation time scale (the time required for the correlation to decay to e-1 equals 0.37) that ranged from about 18 to 66 days, depending on the pesticide type. Simulated daily pesticide concentrations from the time-series model indicated the simulated concentrations for the stations located in the northeastern quadrant of the United States where most of the monitoring stations are located generally were in good agreement with the data. The model neither consistently overestimated or underestimated concentrations for streams that are located in this quadrant and the magnitude and timing of high or low concentrations generally coincided reasonably well with the data. However, further data collection and model development may be necessary to determine whether the model should be used for areas for which few historical data are available.

Scientific Investigations Report↗

Characterization of Preferential Ground-Water Seepage From a Chlorinated Hydrocarbon-Contaminated Aquifer to West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 2002-04

Wetlands act as natural transition zones between ground water and surface water, characterized by the complex interdependency of hydrology, chemical and physical properties, and biotic effects. Although field and laboratory demonstrations have shown efficient natural attenuation processes in the non-seep wetland areas and stream bottom sediments of West Branch Canal Creek, chlorinated volatile organic compounds are present in a freshwater tidal creek at Aberdeen Proving Ground, Maryland. Volatile organic compound concentrations in surface water indicate that in some areas of the wetland, preferential flow paths or seeps allow transport of organic compounds from the contaminated sand aquifer to the overlying surface water without undergoing natural attenuation. From 2002 through 2004, the U.S. Geological Survey, in cooperation with the Environmental Conservation and Restoration Division of the U.S. Army Garrison, Aberdeen Proving Ground, characterized preferential ground-water seepage as part of an ongoing investigation of contaminant distribution and natural attenuation processes in wetlands at this site. Seep areas were discrete and spatially consistent during thermal infrared surveys in 2002, 2003, and 2004 throughout West Branch Canal Creek wetlands. In these seep areas, temperature measurements in shallow pore water and sediment more closely resembled those in ground water than those in nearby surface water. Generally, pore water in seep areas contaminated with chlorinated volatile organic compounds had lower methane and greater volatile organic compound concentrations than pore water in non-seep wetland sediments. The volatile organic compounds detected in shallow pore water in seeps were spatially similar to the dominant volatile organic compounds in the underlying Canal Creek aquifer, with both parent and anaerobic daughter compounds detected. Seep locations characterized as focused seeps contained the highest concentrations of chlorinated parent compounds, relatively low concentrations of chlorinated daughter compounds, and insignificant concentrations of methane in shallow pore water samples. These seeps were primarily along the creek edge or formed a dendritic-like pattern between the wetland and creek channel. In contrast, seep locations characterized as diffuse seeps contained relatively high concentrations of chlorinated daughter compounds (or a mixture of daughter and parent compounds) and detectable methane concentrations in shallow pore water samples. These seeps were primarily along the wetland boundary. Qualitative thermal infrared surveys coupled with quantitative verification of temperature differences, and screening for volatile organic compound and methane concentrations proved to be effective tools in determining the overall extent of preferential seepage. Hydrologic and physical properties of wetland sediments were characterized at two focused and one diffuse seep location. In the seeps with focused discharge, measured seepage was consistent over the tidal cycle, whereas more variability with tidal fluctuation was measured in the diffuse seep location. At all locations, areas were identified within the general seep boundaries where discharge was minimal. In all cases, the geometric mean of non-zero vertical flux measurements was greater than those previously reported in the non-seep wetland sediments using flow-net analysis. Flux was greater in the focused discharge areas than in the diffuse discharge area, and all fluxes were within the range reported in the literature for wetland discharge. Vertical hydraulic conductivity estimated from seepage flux and a mean vertical gradient at seeps with focused discharge resulted in a minimum hydraulic conductivity two orders of magnitude greater than those estimated in the non-seep sediment. In contrast, vertical conductivity estimates at a diffuse seep were similar to estimates along a nearby line of section through a non-seep area.

Scientific Investigations Report↗

Hydrology and glacier-lake-outburst floods (1987-2004) and water quality (1998-2003) of the Taku River near Juneau, Alaska

The Taku River Basin originates in British Columbia, Canada, and drains an area of 6,600 square miles at the U.S. Geological Survey's Taku River gaging station. Several mines operated within the basin prior to 1957, and mineral exploration has resumed signaling potential for future mining developments. The U.S. Geological Survey in cooperation with the Douglas Indian Association, Alaska Department of Environmental Conservation, and the U.S. Environmental Protection Agency conducted a water-quality and flood-hydrology study of the Taku River. Water-quality sampling of the Taku River from 1998 through 2003 established a baseline for assessing potential effects of future mining operations on water quality. The annual mean discharge of the Taku River is 13,700 cubic feet per second. The monthly mean discharge ranges from a minimum of 1,940 cubic feet per second in February to a maximum of 34,400 cubic feet per second in June. Nearly 90 percent of the annual discharge is from May through November. The highest spring discharges are sourced primarily from snowmelt and moderate discharges are sustained throughout the summer by glacial meltwaters. An ice cover usually forms over the Taku River in December persisting through the winter into March and occasionally into April. Glacier-lake-outburst floods originating from two glacier-dammed lakes along the margin of the Tulsequah Glacier in British Columbia, Canada, are the source of the greatest peak discharges on the Taku River. The largest flood during the period of record was 128,000 cubic feet per second on June 25, 2004, resulting from an outburst of Lake No Lake. Lake No Lake is the larger of the two lakes. The outburst-flood contribution to peak discharge was 80,000 cubic feet per second. The volume discharged from Lake No Lake is relatively consistent indicating drainage may be triggered when the lake reaches a critical stage. This suggests prediction of the timing of these outburst floods might be possible if lake-stage data were available. Further increases in the volume of Lake No Lake are unlikely as all tributary glaciers have retreated out of the lake basin. Decreasing outburst-flood volumes from Tulsequah Lake suggests a continued decline in the volume of this lake. Physical and chemical parameters and concentrations of basic water-quality constituents indicate good water quality. Samples collected at the Taku River gaging station contained low concentrations of trace elements in the dissolved phase. Trace elements sampled were within acceptable limits when compared with the Alaska Department of Environmental Conservation aquatic-life criteria for fresh waters. The highest concentrations of total trace elements sampled were collected during glacial-outburst floods and likely are associated with suspended sediments. Total trace-element concentrations generally increase with increasing water discharge, although a high correlation for all constituents sampled does not always exist.

Alaska↗