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Melanie L. Clark

Publications and source records attributed to Melanie L. Clark.

At least 19 recordsLinked to original sources
USGS2015

Assessment of surface water chloride and conductivity trends in areas of unconventional oil and gas development — Why existing national data sets cannot tell us what we would like to know

Heightened concern regarding the potential effects of unconventional oil and gas development on regional water quality has emerged, but the few studies on this topic are limited in geographic scope. Here we evaluate the potential utility of national and publicly available water-quality data sets for addressing questions regarding unconventional oil and gas development. We used existing U.S. Geological Survey and U.S. Environmental Protection Agency data sets to increase understanding of the spatial distribution of unconventional oil and gas development in the U.S. and broadly assess surface water quality trends in these areas. Based on sample size limitations, we were able to estimate trends in specific conductance (SC) and chloride (Cl − ) from 1970 to 2010 in 16% ( n = 155) of the watersheds with unconventional oil and gas resources. We assessed these trends relative to spatiotemporal distributions of hydraulically fractured wells. Results from this limited analysis suggest no consistent and widespread trends in surface water quality for SC and Cl − in areas with increasing unconventional oil and gas development and highlight limitations of existing national databases for addressing questions regarding unconventional oil and gas development and water quality.

Water Resources Research↗
USGS2015

Soil disturbance as a driver of increased stream salinity in a semiarid watershed undergoing energy development

Salinization is a global threat to the quality of streams and rivers, but it can have many causes. Oil and gas development were investigated as one of several potential causes of changes in the salinity of Muddy Creek, which drains 2470 km2 of mostly public land in Wyoming, U.S.A. Stream discharge and salinity vary with seasonal snowmelt and define a primary salinity-discharge relationship. Salinity, measured by specific conductance, increased substantially in 2009 and was 53-71% higher at low discharge and 33-34% higher at high discharge for the years 2009-2012 compared to 2005-2008. Short-term processes (e.g., flushing of efflorescent salts) cause within-year deviations from the primary relation but do not obscure the overall increase in salinity. Dissolved elements associated with increased salinity include calcium, magnesium, and sulfate, a composition that points to native soil salts derived from marine shales as a likely source. Potential causes of the salinity increase were evaluated for consistency by using measured patterns in stream chemistry, slope of the salinity-discharge relationship, and inter-annual timing of the salinity increase. Potential causes that were inconsistent with one or more of those criteria included effects from precipitation, evapotranspiration, reservoirs, grazing, irrigation return flow, groundwater discharge, discharge of energy co-produced waters, and stream habitat restoration. In contrast, surface disturbance of naturally salt-rich soil by oil and gas development activities, such as pipeline, road, and well pad construction, is a reasonable candidate for explaining the salinity increase. As development continues to expand in semiarid lands worldwide, the potential for soil disturbance to increase stream salinity should be considered, particularly where soils host substantial quantities of native salts.

Journal of Hydrology: Regional Studies↗
USGS2015

Water-quality trends for selected sites in the Boulder River and Tenmile Creek watersheds, Montana, based on data collected during water years 1997-2013

In the Boulder River and Tenmile Creek watersheds in southwestern Montana, there was intensive mining during a 40-year period after the discovery of gold in the early 1860s. Potential effects from the historic mining activities include acid-mine drainage and elevated concentrations of potentially toxic trace elements from mining remnants such as waste rock and tailing piles. In support of remediation efforts, water-quality monitoring by the U.S. Geological Survey began in 1997 in the Boulder River and Tenmile Creek watersheds and has continued to present (2014). The U.S. Geological Survey, in cooperation with the U.S. Forest Service, investigated temporal trends in water quality at 13 sites, including 2 adit (or mine entrance) sites and 11 stream sites. The primary purpose of this report is to present results of trend analysis of specific conductance, selected trace-elements (cadmium, copper, lead, zinc, and arsenic), and suspended sediment for the 13 sites. Trend results for most stream sites in the Boulder River watershed for water years 2000–13 (water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends) indicate decreasing trends in flow-adjusted specific conductance, in flow-adjusted concentrations (FACs) for most filtered and unfiltered-recoverable trace elements, and in suspended sediment. Overall, magnitudes of the decreasing trends in FACs of metallic contaminants are largest for Bullion Mine tributary at mouth (site 3), Jack Creek at mouth (site 4), and Cataract Creek at Basin (site 8). For sites 3, 4, and 8, magnitudes of decreasing trends generally ranged from about -5 to -10 percent per year. Notably, the watersheds upstream from sites 3, 4, and 8 have been targeted by substantial remediation activities. Consideration of trend patterns among all stream sites in the Boulder River watershed provides strong evidence that remediation activities are the primary cause of decreasing trends in metallic contaminants. Trend results for sites in the Tenmile Creek watershed generally are more variable and difficult to interpret than for sites in the Boulder River watershed. Trend results for Tenmile Creek above City Diversion (site 11) and Minnehaha Creek near Rimini (site 12) for water years 2000–13 indicate decreasing trends in FACs of cadmium, copper, and zinc. The magnitudes of the decreasing trends in FACs of copper generally are moderate and statistically significant for sites 11 and 12. The magnitudes of the decreasing trends in FACs of cadmium and zinc for site 11 are minor to small and not statistically significant; however, the magnitudes for site 12 are moderate and statistically significant. In general, patterns in FACs for Tenmile Creek near Rimini (site 13) are not well represented by fitted trends within the short data collection period, which might indicate that the trend-analysis structure of the study is not appropriate for describing trends in FACs for site 13. The large decreasing trend in FACs of suspended sediment is the strongest indication of change in water quality during the short period of record for site 13; however, this trend is not statistically significant.

Montana↗
USGS2014

U.S. Geological Survey Science for the Wyoming Landscape Conservation Initiative: 2012 annual report

Southwest Wyoming contains abundant energy resources, wildlife, habitat, open spaces, and outdoor recreational opportunities. Although energy exploration and development have been taking place in the region since the late 1800s, the pace of development for fossil fuels and renewable energy increased significantly in the early 2000s. This and the associated urban and exurban development are leading to landscape-level environmental and socioeconomic changes that have the potential to diminish wildlife habitat and other natural resources, and the quality of human lives, in Southwest Wyoming. The potential for negative effects of these changes prompted Federal, State, and local agencies to undertake the Wyoming Landscape Conservation Initiative for Southwest Wyoming.

Wyoming↗
USGS2014

Trends in major-ion constituents and properties for selected sampling sites in the Tongue and Powder River watersheds, Montana and Wyoming, based on data collected during water years 1980-2010

The primary purpose of this report is to present information relating to flow-adjusted temporal trends in major-ion constituents and properties for 16 sampling sites in the Tongue and Powder River watersheds based on data collected during 1980–2010. In association with this primary purpose, the report presents background information on major-ion characteristics (including specific conductance, calcium, magnesium, potassium, sodium adsorption ratio, sodium, alkalinity, chloride, fluoride, dissolved sulfate, and dissolved solids) of the sampling sites and coal-bed methane (CBM) produced water (groundwater pumped from coal seams) in the site watersheds, trend analysis methods, streamflow conditions, and factors that affect trend results. The Tongue and Powder River watersheds overlie the Powder River structural basin (PRB) in northeastern Wyoming and southeastern Montana. Limited extraction of coal-bed methane (CBM) from the PRB began in the early 1990’s, and increased dramatically during the late 1990’s and early 2000’s. CBM-extraction activities produce discharges of water with high concentrations of dissolved solids (particularly sodium and bicarbonate ions) relative to most stream water in the Tongue and Powder River watersheds. Water-quality of CBM produced water is of concern because of potential effects of sodium on agricultural soils and potential effects of bicarbonate on aquatic biota. Two parametric trend-analysis methods were used in this study: the time-series model (TSM) and ordinary least squares regression (OLS) on time, streamflow, and season. The TSM was used to analyze trends for 11 of the 16 study sites. For five sites, data requirements of the TSM were not met and OLS was used to analyze trends. Two primary 10-year trend-analysis periods were selected. Trend-analysis period 1 (water years 1986–95; hereinafter referred to as period 1) was selected to represent variability in major-ion concentrations in the Tongue and Powder River watersheds before potential effects of CBM-extraction activities. Trend analysis period 2 (water years 2001–10; hereinafter referred to as period 2) was selected because it encompassed substantial CBM-extraction activities and therefore might indicate potential effects of CBM-extraction activities on water quality of receiving streams in the Tongue and Powder River watersheds. For sites that did not satisfy data requirements for the TSM, OLS was used to analyze trends for period 2 (if complete data were available) or a 6-year period (2005–10). Flow-rate characteristics of CBM-produced water were estimated to allow general comparisons with streamflow characteristics of the sampling sites. The information on flow-rate characteristics of CBM-produced water in relation to streamflow does not account for effects of disposal, treatment, or other remediation activities on the potential quantitative effects of CBM-produced water on receiving streams. In many places, CBM-produced water is discharged into impoundments or channels in upper reaches of tributary watersheds where water infiltrates and does not directly contribute to streamflow. For Tongue River at State line (site 4) mean annual pumping rate of CBM-produced water during water years 2001–10 (hereinafter referred to as mean CBM pumping rate) was 6 percent of the mean of annual median streamflows during water years 2001–10 (hereinafter referred to as 2001–10 median streamflow). For main-stem Tongue River sites 5, 7, and 10, mean CBM pumping rate was 8–12 percent of 2001–10 median streamflow. For main-stem Powder River sites (sites 12, 13, and 16), mean CBM pumping rates were 26, 28, and 34 percent of 2001–10 median streamflows, respectively. For main-stem Tongue River sites analyzed by using the TSM and downstream from substantial CBM-extraction activities [Tongue River at State line (site 4), Tongue River at Tongue River Dam (site 5), Tongue River at Birney Day School (site 7), and Tongue River at Miles City (site 10)], generally small significant or nonsignificant decreases in most constituents are indicated for period 1. For period 2 for these sites, the TSM trend results do not allow confident conclusions concerning detection of effects of CBM-extraction activities on stream water quality. Detection of significant trends in major-ion constituents and properties for period 2 generally was infrequent, and direction, magnitudes, and significance of fitted trends were not strongly consistent with relative differences in water quality between stream water and CBM-produced water. The TSM indicated significant or generally large magnitude increases in median values of sodium adsorption ratio (SAR), sodium, and alkalinity for period 2 for sites 5 and 7, which might indicate potential effects of CBM-extraction activities on stream water. However, other factors, including operations of Tongue River Reservoir, irrigation activities, contributions of saline groundwater, and operations of the Decker coal mine, confound confident determination of causes of detected significant trends for sites 5 and 7. For all mainstem Tongue River sites, trends for period 2 generally are within ranges of those for period 1 before substantial CBM-extraction activities. For main-stem Powder River sites analyzed by using the TSM [Powder River at Sussex (site 11), Powder River at Arvada (site 12), Powder River at Moorhead (site 13), and Powder River near Locate (site 16)], significant or generally large magnitude decreases in median values of SAR, sodium, estimated alkalinity, chloride, fluoride, specific conductance, and dissolved solids are indicated for period 1. Patterns in trend results for period 1 for main-stem Powder River sites are consistent with effects of Salt Creek oil-brine reinjection that started in 1990. Trend results for all main-stem Powder River sites downstream from substantial CBM-extraction activities (sites 12, 13, and 16) indicate evidence of potential effects of CBM-extraction activities on stream water quality, although evidence is stronger for sites 12 and 13 than for site 16. Evidence in support of potential CBM effects includes significant increases in median values of SAR, sodium, and estimated alkalinity for period 2 for sites 12, 13, and 16 that are consistent with relative differences between stream water and CBM-produced water. Significant increases in median values of these constituents for period 2 are not indicated for Powder River at Sussex (site 11) upstream from substantial CBM-extraction activities. In interpreting the trend results, it is notable that the fitted trends evaluate changes in median concentrations and also notable that changes in median concentrations that might be attributed to CBM-extraction activities probably are more strongly evident during low to median streamflow conditions than during mean to high streamflow conditions. This observation is relevant in assessing trend results in relation to specific water-quality concerns, including effects of water-quality changes on irrigators and effects on stream biota and ecology.

Montana;Wyoming↗
USGS2013

U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative: 2011 annual report

This is the fourth report produced by the U.S. Geological Survey (USGS) for the Wyoming Landscape Conservation Initiative (WLCI) to detail annual work activities. In FY2011, there were 37 ongoing, completed, or new projects conducted under the five major multi-disciplinary science and technical-assistance activities: (1) Baseline Synthesis, (2) Targeted Monitoring and Research, (3) Data and Information Management, (4) Integration and Coordination, and (5) Decisionmaking and Evaluation. The four new work activities were (1) development of the Western Energy Citation Clearinghouse, a Web-based energy-resource database of references for literature and on-line resources focused on energy development and its effects on natural resources; (2) a study to support the Sublette County Conservation District in ascertaining potential water-quality impacts to the New Fork River from energy development in the Pinedale Anticline Project Area; (3) a study to test the efficacy of blending high-frequency temporal data provided by Moderate Resolution Imaging Spectroradiometer (MODIS) sensors and high-resolution Landsat data for providing the fine-resolution data required to evaluate habitat responses to management activities at the landscape level; and (4) a study to examine the seasonal water chemistry of Muddy Creek, including documenting salinity patterns and providing a baseline for assessing potential effects of energy and other development on water quality in the Muddy Creek watershed. Two work activities were completed in FY2011: (1) the assessment of rancher perceptions of energy development in Southwest Wyoming and (2) mapping aspen stands and conifer encroachment using classification and regression tree (CART) analysis for effectiveness monitoring. The USGS continued to compile data, develop geospatial products, and upgrade Web-based products in support of both individual and overall WLCI efforts, including (1) ranking and prioritizing proposed conservation projects, (2) developing the WLCI integrated assessment, (3) developing the WLCI 5-year Conservation Action Plan, and (4) continuing to upgrade the content and improve the functionality of the WLCI Web site. For the WLCI FY2012 annual report, a decision was made to greatly reduce the overall length of the annual report, which will be accomplished by simplifying the report format and focusing on the take-home messages of each work activity for WLCI partners.

Wyoming↗
USGS2013

User’s manual for the National Water Information System of the U.S. Geological Survey: Water-Quality System

This user documentation is designed to be a reference for the quality of water (QW) programs within the National Water Information System (NWIS). If you are a new user, the “Introduction” and “Getting Started” sections may be the right place for you to start. If you are an experienced user, you may want to go straight to the details provided in the “Program” section (section 3). Code lists and some miscellaneous reference materials are provided in the Appendices. The last section, “Tip Sheets,” is a collection of suggestions for accomplishing selected tasks, some of which are basic and some are advanced. These tip sheets are referenced in the main text of the documentation where appropriate.

Open-File Report↗
USGS2012

Groundwater-quality and quality-control data for two monitoring wells near Pavillion, Wyoming, April and May 2012

In June 2010, the U.S. Environmental Protection Agency installed two deep monitoring wells (MW01 and MW02) near Pavillion, Wyoming, to study groundwater quality. During April and May 2012, the U.S Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, collected groundwater-quality data and quality-control data from monitoring well MW01 and, following well redevelopment, quality-control data for monitoring well MW02. Two groundwater-quality samples were collected from well MW01—one sample was collected after purging about 1.5 borehole volumes, and a second sample was collected after purging 3 borehole volumes. Both samples were collected and processed using methods designed to minimize atmospheric contamination or changes to water chemistry. Groundwater-quality samples were analyzed for field water-quality properties (water temperature, pH, specific conductance, dissolved oxygen, oxidation potential); inorganic constituents including naturally occurring radioactive compounds (radon, radium-226 and radium-228); organic constituents; dissolved gasses; stable isotopes of methane, water, and dissolved inorganic carbon; and environmental tracers (carbon-14, chlorofluorocarbons, sulfur hexafluoride, tritium, helium, neon, argon, krypton, xenon, and the ratio of helium-3 to helium-4). Quality-control sample results associated with well MW01 were evaluated to determine the extent to which environmental sample analytical results were affected by bias and to evaluate the variability inherent to sample collection and laboratory analyses. Field documentation, environmental data, and quality-control data for activities that occurred at the two monitoring wells during April and May 2012 are presented.

Wyoming↗
USGS2012

Water-quality characteristics and trend analyses for the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins, Wyoming and Montana, for selected periods, water years 1991 through 2010

The Powder River structural basin in northeastern Wyoming and southeastern Montana is an area of ongoing coalbed natural gas (CBNG) development. Waters produced during CBNG development are managed with a variety of techniques, including surface impoundments and discharges into stream drainages. The interaction of CBNG-produced waters with the atmosphere and the semiarid soils of the Powder River structural basin can affect water chemistry in several ways. Specific conductance and sodium adsorption ratios (SAR) of CBNG-produced waters that are discharged to streams have been of particular concern because they have the potential to affect the use of the water for irrigation. Water-quality monitoring has been conducted since 2001 at main-stem and tributary sites in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins in response to concerns about CBNG effects. A study was conducted to summarize characteristics of stream-water quality for water years 2001–10 (October 1, 2000, to September 30, 2010) and examine trends in specific conductance, SAR, and primary constituents that contribute to specific conductance and SAR for changes through time (water years 1991–2010) that may have occurred as a result of CBNG development. Specific conductance and SAR are the focus characteristics of this report. Dissolved calcium, magnesium, and sodium, which are primary contributors to specific conductance and SAR, as well as dissolved alkalinity, chloride, and sulfate, which are other primary contributors to specific conductance, also are described. Stream-water quality in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins was variable during water years 2001–10, in part because of variations in streamflow. In general, annual runoff was less than average during water years 2001–06 and near or above average during water years 2007–10. Stream water of the Tongue River had the smallest specific conductance values, sodium adsorption ratios, and major ion concentrations of the main-stem streams. Sites in the Tongue River drainage basin typically had the smallest range of specific conductance and SAR values. The water chemistry of sites in the Powder River drainage basin generally was the most variable as a result of diverse characteristics of that basin. Plains tributaries in the Powder River drainage basin had the largest range of specific conductance and SAR values, in part due to the many tributaries that receive CBNG-produced waters. Trends were analyzed using the seasonal Kendall test with flow-adjusted concentrations to determine changes to water quality through time at sites in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins. Trends were evaluated for water years 2001–10 for 17 sites, which generally were on the main-stem streams and primary tributaries. Trends were evaluated for water years 2005–10 for 26 sites to increase the spatial coverage of sites. Trends were evaluated for water years 1991–2010 for eight sites to include water-quality data collected prior to widespread CBNG development and expand the temporal context of trends. Consistent patterns were not observed in trend results for water years 2001–10 for flow-adjusted specific conductance and SAR values in the Tongue, Powder, and Belle Fourche River drainage basins. Significant (p-values less than 0.05) upward trends in flow-adjusted specific conductance values were determined for 3 sites, a downward trend was determined for 1 site, and no significant (p-value greater than 0.05) trends were determined for 13 sites. One of the sites with a significant upward trend was the Tongue River at the Wyoming-Montana State line. No trend in flow-adjusted specific conductance values was determined for the Powder River at Moorhead, Mont. Significant upward trends in flow-adjusted SAR values were determined for 2 sites and no significant trends were determined for 15 sites. No trends in flow-adjusted SAR values were determined for the Tongue River at the Wyoming-Montana State line or for the Powder River at Moorhead, Mont. One of the sites with a significant upward trend in flow-adjusted SAR values was the Powder River at Arvada, Wyo. For water years 2005–10, significant upward trends in flow-adjusted specific conductance values were determined no significant trends were determined for 13 sites. A significant upward trend was determined for flow-adjusted specific conductance values for the Tongue River at the Wyoming-Montana State line. No trend in flow-adjusted specific conductance values was determined for the Powder River at Moorhead, Mont. Significant upward trends in flow-adjusted SAR values were determined for 4 sites, downward trends were determined for 5 sites, and no significant trend was determined for 17 sites. No trends in flow-adjusted SAR values were determined for the Tongue River at the Wyoming-Montana State line or for the Powder River at Moorhead, Mont. Results of the seasonal Kendall test applied to flow-adjusted specific conductance values for water years 1991–2010 indicated no significant trend for eight sites in the Tongue, Powder, and Belle Fourche River drainage basins. No significant trend in flow-adjusted specific conductance was determined for the Tongue River at the Wyoming-Montana State line or the Powder River at Moorhead, Mont. Results of the seasonal Kendall test applied to flow-adjusted SAR values for water years 1991–2010 indicated an upward trend for one site and no significant trend for four sites in the Powder and Belle Fourche River drainage basins. The significant upward trend in flow-adjusted SAR values was determined for the Powder River at Arvada, Wyo., for water years 1991–2010. Results indicate that CBNG development in the Powder River structural basin may have contributed to some trends, such as the upward trend in flow-adjusted SAR for the Powder River at Arvada, Wyo., for water years 1991–2010. An upward trend in flow-adjusted alkalinity concentrations for water years 2001–10 also was determined for the Powder River at Arvada, Wyo. Trend results are consistent with changes that can occur from the addition of sodium and bicarbonate associated with CBNG-produced waters to the Powder River. Upward trends in constituents at other sites, including the Belle Fourche River, may be the result of declining CBNG development, indicating that CBNG-produced waters may have had a dilution effect on some streams. The factors affecting other trends could not be determined because multiple factors could have been affecting the stream-water quality or because trends were observed at sites upstream from CBNG development that may have affected water-quality trends at sites downstream.

Wyoming;Montana↗
USGS2011

U.S. Geological Survey Science for the Wyoming Landscape Conservation Initiative-2010 Annual Report

This is the third report produced by the U.S. Geological Survey (USGS) for the Wyoming Landscape Conservation Initiative (WLCI) to detail annual work activities. The first report described activities for 2007 and 2008, and the second report covered work activities for FY09. This third report covers work activities conducted in FY2010, and it continues the 2009 approach of reporting on all the individual activities to help give WLCI partners and other readers the full scope of what has been accomplished. New in this year's report is an additional section for each work activity that outlines the work planned for the following fiscal year. In FY2010, there were 35 ongoing/expanded, completed, or new projects conducted under the five major multi-disciplinary science and technical-assistance activities: (1) Baseline Synthesis; (2) Targeted Monitoring and Research; (3) Data and Information Management; (4) Integration and Coordination; and (5) Decisionmaking and Evaluation. The three new work activities were to (1) compile existing water data for the entire WLCI region and (2) develop regional curves (statistical models) for relating bankfull-channel geometry and discharge to drainages in the WLCI region, both of which will help guide long-term monitoring of water resources; and (3) initiate a groundwater-monitoring network to evaluate potential effects of energy-development activities on groundwater quality where groundwater is an important source of public/private water supplies. Results of the FY2009 work to develop methods for assessing soil organic matter and mercury indicated that selenium and arsenic levels may be elevated in the Muddy Creek Basin; thus, the focus of that activity was shifted in FY2010 to evaluate biogeochemical cycling of elements in the basin. In FY2010, two ongoing activities were expanded with the addition of more sampling plots: (a) the study of how greater sage-grouse (Centrocercus urophasianus) use vegetation-treatment areas (sites added to the Moxa Arch Natural Gas Development area) and (2) the study of cheatgrass (Bromus tectorum) occurrence in burn treatments of the Little Mountain Ecosystem. The activity that entails evaluating relationships between ungulate herbivory and fire on aspen (Populus tremuloides) recruitment also was expanded to include relationships between stand characteristics of and herbivory on aspen in various ecohydrological settings. The USGS continued compiling data and developing geospatial products from all of its WLCI activities to support (1) ranking and prioritizing of proposed conservation projects, (2) developing the WLCI Integrated Assessment, and (3) developing the WLCI 5-year Conservation Action Plan. Two activities were completed in FY2010: (1) the conceptual modeling and indicator selection for monitoring resource conditions across the WLCI region, and (2) the literature review on effects of oil and gas development in western regions of the United States, both of which are in the last stages of publication.

Open-File Report↗
USGS2010

Assessment of ecological conditions and potential effects of water produced from coalbed natural gas development on biological communities in streams of the Powder River structural basin, Wyoming and Montana, 2005-08

Ongoing development of coalbed natural gas in the Powder River structural basin in Wyoming and Montana led to formation of an interagency task group to address concerns about the effects of the resulting production water on biological communities in streams of the area. The interagency task group developed a monitoring plan and conducted sampling of macroinvertebrate, algal, and fish communities at 47 sites during 2005-08 to document current ecological conditions and determine existing and potential effects of water produced from coalbed natural gas development on biological communities. Macroinvertebrate, algal, and fish community composition varied between drainage basins, among sites within drainage basins, and by year. Macroinvertebrate communities of the main-stem Tongue River were characterized by higher taxa richness and higher abundance of Ephemeroptera, for example, compared to macroinvertebrate communities in plains tributaries of the Tongue River and the main-stem Powder River. Fish communities of the Tongue River were characterized by higher taxa richness and abundance of introduced species compared to the Powder River where native species were dominant. Macroinvertebrate community metric values from sites in the middle reach of the main-stem Powder River, from below Willow Creek to below Crazy Woman Creek, differed from metric values in the upper and lower reaches of the Powder River. Metrics indicative of communitywide differences included measures of taxa richness, relative abundance, feeding mode, and tolerance. Some of the variation in the macroinvertebrate communities could be explained by variation in environmental variables, including physical (turbidity, embeddedness, bed substrate size, and streamflow) and chemical (alkalinity and specific conductance) variables. Of these environmental variables, alkalinity was the best indicator of coalbed natural gas development because of the sodiumbicarbonate signature of the production water. Algal samples from the main-stem Powder River generally confirmed the pattern observed in the macroinvertebrate communities. Algal communities at sites in the middle reach of the Powder River commonly were characterized by dominance by a single taxon and by low biovolume of algae compared to other sites. In contrast to the macroinvertebrate and algal communities, species richness of fish communities was highest in the middle reach of the Powder River. Although a few significant differences in fish metrics were determined along the main-stem Powder River, the differences did not correspond to the pattern observed for the macroinvertebrate and algae communities. Differences in biological communities were noted between years, potentially due to the effects of drought. Macroinvertebrate community metrics, such as Diptera taxa richness, were significantly different in the severe drought year of 2006 from metric values in 2005 and 2007-08. Waterquality data collected during the study indicated that, with few exceptions, water-quality constituents generally did not exceed State or Federal acute and chronic criteria for the protection of aquatic life.

Scientific Investigations Report↗
USGS2009

Specific Conductance and Dissolved-Solids Characteristics for the Green River and Muddy Creek, Wyoming, Water Years 1999-2008

Southwestern Wyoming is an area of diverse scenery, wildlife, and natural resources that is actively undergoing energy development. The U.S. Department of the Interior's Wyoming Landscape Conservation Initiative is a long-term science-based effort to assess and enhance aquatic and terrestrial habitats at a landscape scale, while facilitating responsible energy development through local collaboration and partnerships. Water-quality monitoring has been conducted by the U.S. Geological Survey on the Green River near Green River, Wyoming, and Muddy Creek near Baggs, Wyoming. This monitoring, which is being conducted in cooperation with State and other Federal agencies and as part of the Wyoming Landscape Conservation Initiative, is in response to concerns about potentially increased dissolved solids in the Colorado River Basin as a result of energy development. Because of the need to provide real-time dissolved-solids concentrations for the Green River and Muddy Creek on the World Wide Web, the U.S. Geological Survey developed regression equations to estimate dissolved-solids concentrations on the basis of continuous specific conductance using relations between measured specific conductance and dissolved-solids concentrations. Specific conductance and dissolved-solids concentrations were less varied and generally lower for the Green River than for Muddy Creek. The median dissolved-solids concentration for the site on the Green River was 318 milligrams per liter, and the median concentration for the site on Muddy Creek was 943 milligrams per liter. Dissolved-solids concentrations ranged from 187 to 594 milligrams per liter in samples collected from the Green River during water years 1999-2008. Dissolved-solids concentrations ranged from 293 to 2,485 milligrams per liter in samples collected from Muddy Creek during water years 2006-08. The differences in dissolved-solids concentrations in samples collected from the Green River compared to samples collected from Muddy Creek reflect the different basin characteristics. Relations between specific conductance and dissolved-solids concentrations were statistically significant for the Green River (p-value less than 0.001) and Muddy Creek (p-value less than 0.001); therefore, specific conductance can be used to estimate dissolved-solids concentrations. Using continuous specific conductance values to estimate dissolved solids in real-time on the World Wide Web increases the amount and improves the timeliness of data available to water managers for assessing dissolved-solids concentrations in the Colorado River Basin.

Scientific Investigations Report↗
USGS2007

Nutrient and Suspended-Sediment Trends in the Missouri River Basin, 1993-2003

Trends in streamflow and concentration of total nitrogen, nitrite plus nitrate, ammonia, total phosphorus, orthophosphorus, and suspended sediment were determined for the period from 1993 to 2003 at selected stream sites in the Missouri River Basin. Flow-adjusted trends in concentration (the trends that would have occurred in the absence of natural changes in streamflow) and non-flow-adjusted trends in concentration (the overall trends resulting from natural and human factors) were determined. In the analysis of flow-adjusted trends, the removal of streamflow as a variable affecting concentration allowed trends caused by other factors such as implementation of best management practices to be identified. In the analysis of non-flow-adjusted trends, the inclusion of any and all factors affecting concentration allowed trends affecting aquatic ecosystems and the status of streams relative to water-quality standards to be identified. Relations between the flow-adjusted and non-flow-adjusted trends and changes in streamflow, nutrient sources, ground-water inputs, and implementation of management practices also were examined to determine the major factors affecting the trends. From 1993 to 2003, widespread downward trends in streamflow indicated that drought conditions from about 2000 to 2003 led to decreasing streamflow throughout much of the Missouri River Basin. Flow-adjusted trends in nitrite plus nitrate and ammonia concentrations were split nearly equally between nonsignificant and downward; at about one-half of the sites, management practices likely were contributing to measurable decreases in concentrations of nitrite plus nitrate and ammonia. Management practices had less of an effect on concentrations of total nitrogen; downward flow-adjusted trends in total nitrogen concentrations occurred at only 2 of 19 sites. The pattern of non-flow-adjusted trends in nitrite plus nitrate concentrations was similar to the pattern of flow-adjusted trends; non-flow-adjusted trends were split nearly equally between nonsignificant and downward. A substantial source of nitrite plus nitrate to these streams likely was ground water; because of the time required for ground water to travel to streams, there may have been a lag time between the implementation of some pollution-control strategies and improvement in stream quality, contributing to the nonsignificant trends in nitrite plus nitrate. There were more sites with downward non-flow-adjusted trends than flow-adjusted trends in both ammonia and total nitrogen concentrations, possibly a result of decreased surface runoff from nonpoint sources associated with the downward trends in streamflow. No strong relations between any of the nitrogen trends and changes in nutrient sources or landscape characteristics were identified. Although there were very few upward trends in nitrogen from 1993 to 2003, there were upward flow-adjusted trends in total phosphorus concentrations at nearly one-half of the sites. At these sites, not only were pollution-control strategies not contributing to measurable decreases in total phosphorus concentrations, there was likely an increase in phosphorus loading on the land surface. There were fewer upward non-flow-adjusted than flow-adjusted trends in total phosphorus concentrations; at the majority of sites, overall total phosphorus concentrations did not change significantly during this period. The preponderance of upward flow-adjusted trends and nonsignificant non-flow-adjusted trends indicates that in some areas of the Missouri River Basin, overall concentrations of total phosphorus would have been higher without the decrease in streamflow and the associated decrease in surface runoff during the study period. During the study period, phosphorus loads from fertilizer generally increased at over one-half of the sites in the basin. Upward flow-adjusted trends were related to increasing fertilizer use in the upstream drainage area, particularly in the 10 percent

Scientific Investigations Report↗
USGS2007

Water-Quality Characteristics for Sites in the Tongue, Powder, Cheyenne, and Belle Fourche River Drainage Basins, Wyoming and Montana, Water Years 2001-05, with Temporal Patterns of Selected Long-Term Water-Quality Data

Water-quality sampling was conducted regularly at stream sites within or near the Powder River structural basin in northeastern Wyoming and southeastern Montana during water years 2001-05 (October 1, 2000, to September 30, 2005) to characterize water quality in an area of coalbed natural gas development. The U.S. Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, characterized the water quality at 22 sampling sites in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins. Data for general hydrology, field measurements, major-ion chemistry, and selected trace elements were summarized, and specific conductance and sodium-adsorption ratios were evaluated for relations with streamflow and seasonal variability. Trend analysis for water years 1991-2005 was conducted for selected sites and constituents to assess change through time. Average annual runoff was highly variable among the stream sites. Generally, streams that have headwaters in the Bighorn Mountains had more runoff as a result of higher average annual precipitation than streams that have headwaters in the plains. The Powder River at Moorhead, Mont., had the largest average annual runoff (319,000 acre-feet) of all the sites; however, streams in the Tongue River drainage basin had the highest runoff per unit area of the four major drainage basins. Annual runoff in all major drainage basins was less than average during 2001-05 because of drought conditions. Consequently, water-quality samples collected during the study period may not represent long-term water-quality con-ditions for all sites. Water-quality characteristics were highly variable generally because of streamflow variability, geologic controls, and potential land-use effects. The range of median specific-conductance values among sites was smallest in the Tongue River drainage basin. Median values in that basin ranged from 643 microsiemens per centimeter at 25 degrees Celsius (?S/cm at 25?C) on the Tongue River to 1,460 ?S/cm at 25?C on Prairie Dog Creek. The Tongue River drainage basin has the largest percentage of area underlain by Mesozoic-age and older rocks and by more resistant rocks. In addition, the higher annual precipitation and a steeper gradient in this basin compared to basins in the plains produce relatively fast stream velocities, which result in a short contact time between stream waters and basin materials. The Powder River drainage basin, which has the largest drainage area and most diverse site conditions, had the largest range of median specific-conductance values among the four major drainage basins. Median values in that basin ranged from 680 ?S/cm at 25?C on Clear Creek to 5,950 ?S/cm at 25?C on Salt Creek. Median specific-conductance values among sites in the Cheyenne River drainage basin ranged from 1,850 ?S/cm at 25?C on Black Thunder Creek to 4,680 ?S/cm at 25?C on the Cheyenne River. The entire Cheyenne River drainage basin is in the plains, which have low precipitation, soluble geologic materials, and relatively low gradients that produce slow stream velocities and long contact times. Median specific-conductance values among sites in the Belle Fourche River drainage basin ranged from 1,740 ?S/cm at 25?C on Caballo Creek to 2,800 ?S/cm at 25?C on Donkey Creek. Water in the study area ranged from a magnesium-calcium-bicarbonate type for some sites in the Tongue River drainage basin to a sodium-sulfate type at many sites in the Powder, Cheyenne, and Belle Fourche River drainage basins. Little Goose Creek, Goose Creek, and the Tongue River in the Tongue River drainage basin, and Clear Creek in the Powder River drainage basin, which have headwaters in the Bighorn Mountains, consistently had the smallest median dissolved-sodium concentrations, sodium-adsorption ratios, dissolved-sulfate concentrations, and dissolved-solids concentrations. Salt Creek, Wild Horse Creek, Little Powder River, and the Cheyenne River, which have headwat

Scientific Investigations Report↗
USGS2007

Water-Quality Characteristics of Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek, Grand Teton National Park, Wyoming, 2006

To address water-resource management objectives of the National Park Service in Grand Teton National Park, the U.S. Geological Survey in cooperation with the National Park Service has conducted water-quality sampling on streams in the Snake River headwaters area. A synoptic study of streams in the western part of the headwaters area was conducted during 2006. Sampling sites were located on Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek. Sampling events in June, July, August, and October were selected to characterize different hydrologic conditions and different recreational-use periods. Stream samples were collected and analyzed for field measurements, major-ion chemistry, nutrients, selected trace elements, pesticides, and suspended sediment. Water types of Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek were calcium bicarbonate. Dissolved-solids concentrations were dilute in Cottonwood Creek and Taggart Creek, which drain Precambrian-era rocks and materials derived from these rocks. Dissolved-solids concentrations ranged from 11 to 31 milligrams per liter for samples collected from Cottonwood Creek and Taggart Creek. Dissolved-solids concentrations ranged from 55 to 130 milligrams per liter for samples collected from Lake Creek and Granite Creek, which drain Precambrian-era rocks and Paleozoic-era rocks and materials derived from these rocks. Nutrient concentrations generally were small in samples collected from Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek. Dissolved-nitrate concentrations were the largest in Taggart Creek. The Taggart Creek drainage basin has the largest percentage of barren land cover of the basins, and subsurface waters of talus slopes may contribute to dissolved-nitrate concentrations in Taggart Creek. Pesticide concentrations, trace-element concentrations, and suspended-sediment concentrations generally were less than laboratory reporting levels or were small for all samples. Water-quality characteristics of streams in the western part of the Snake River headwaters area were compared to water-quality characteristics of streams sampled in 2002 in the eastern part of the headwaters area. The median dissolved-solids concentration (55 milligrams per liter) for samples collected from western streams was smaller than the median dissolved-solids concentration (125 milligrams per liter) for samples collected from eastern streams. The small dissolved-solids concentrations in the western streams are a result of the large areas underlain by resistant Precambrian-era rocks that compose the Teton Range compared to the more erodable Mesozoic-era sedimentary rocks that compose the mountains in the eastern part of the headwaters area. The Teton Range also receives higher annual precipitation than the mountains in the east. The median total-nitrogen concentration (0.17 milligram per liter) in samples collected from streams in the western part of the Snake River headwaters area was larger than the median concentration (0.10 milligram per liter) for samples collected from streams in the eastern part of the headwaters area, in part because of larger dissolved-nitrate concentrations in samples from the western streams compared to the eastern streams. In contrast, total-phosphorus concentrations generally were larger for samples collected from eastern streams. Large total-phosphorus concentrations in the eastern streams were associated with large suspended-sediment concentrations. The source of the phosphorus and sediment probably is Mesozoic-era sedimentary rocks of marine origin that underlie parts of the eastern drainage basins.

Scientific Investigations Report↗
USGS2006

Water-quality characteristics, including sodium-adsorption ratios, for four sites in the Powder River drainage basin, Wyoming and Montana, water years 2001-2004

The U.S. Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, monitors streams throughout the Powder River structural basin in Wyoming and parts of Montana for potential effects of coalbed natural gas development. Specific conductance and sodium-adsorption ratios may be larger in coalbed waters than in stream waters that may receive the discharge waters. Therefore, continuous water-quality instruments for specific conductance were installed and discrete water-quality samples were collected to characterize water quality during water years 2001-2004 at four sites in the Powder River drainage basin: Powder River at Sussex, Wyoming; Crazy Woman Creek near Arvada, Wyoming; Clear Creek near Arvada, Wyoming; and Powder River at Moorhead, Montana. During water years 2001-2004, the median specific conductance of 2,270 microsiemens per centimeter at 25 degrees Celsius (?S/cm) in discrete samples from the Powder River at Sussex, Wyoming, was larger than the median specific conductance of 1,930 ?S/cm in discrete samples collected downstream from the Powder River at Moorhead, Montana. The median specific conductance was smallest in discrete samples from Clear Creek (1,180 ?S/cm), which has a dilution effect on the specific conductance for the Powder River at Moorhead, Montana. The daily mean specific conductance from continuous water-quality instruments during the irrigation season showed the same spatial pattern as specific conductance values for the discrete samples. Dissolved sodium, sodium-adsorption ratios, and dissolved solids generally showed the same spatial pattern as specific conductance. The largest median sodium concentration (274 milligrams per liter) and the largest range of sodium-adsorption ratios (3.7 to 21) were measured in discrete samples from the Powder River at Sussex, Wyoming. Median concentrations of sodium and sodium-adsorption ratios were substantially smaller in Crazy Woman Creek and Clear Creek, which tend to decrease sodium concentrations and sodium-adsorption ratios at the Powder River at Moorhead, Montana. Dissolved-solids concentrations in discrete samples were closely correlated with specific conductance values; Pearson's correlation coefficients were 0.98 or greater for all four sites. Regression equations for discrete values of specific conductance and sodium-adsorption ratios were statistically significant (p-values <0.001) at all four sites. The strongest relation (R2=0.92) was at the Powder River at Sussex, Wyoming. Relations on Crazy Woman Creek (R2=0.91) and Clear Creek (R2=0.83) also were strong. The relation between specific conductance and sodium-adsorption ratios was weakest (R2=0.65) at the Powder River at Moorhead, Montana; however, the relation was still significant. These data indicate that values of specific conductance are useful for estimating sodium-adsorption ratios. A regression model called LOADEST was used to estimate dissolved-solids loads for the four sites. The average daily mean dissolved-solids loads varied among the sites during water year 2004. The largest average daily mean dissolved-solids load was calculated for the Powder River at Moorhead, Montana. Although the smallest concentrations of dissolved solids were in samples from Clear Creek, the smallest average daily mean dissolved-solids load was calculated for Crazy Woman Creek. The largest loads occurred during spring runoff, and the smallest loads occurred in late summer, when streamflows typically were smallest. Dissolved-solids loads may be smaller than average during water years 2001-2004 because of smaller than average streamflow as a result of drought conditions.

Scientific Investigations Report↗
USGS2005

Water-Quality Assessment of the Yellowstone River Basin, Montana and Wyoming-Water Quality of Fixed Sites, 1999-2001

The National Water-Quality Assessment Program of the U.S. Geological Survey initiated an assessment in 1997 of the quality of water resources in the Yellowstone River Basin. Water-quality samples regularly were collected during 1999-2001 at 10 fixed sites on streams representing the major environmental settings of the basin. Integrator sites, which are heterogeneous in land use and geology, were established on the mainstem of the Yellowstone River (4 sites) and on three major tributaries?Clarks Fork Yellowstone River (1 site), the Bighorn River (1 site), and the Powder River (1 site). Indicator sites, which are more homogeneous in land use and geology than the integrator sites, were located on minor tributaries with important environmental settings?Soda Butte Creek in a mineral resource area (1 site), the Tongue River in a forested area (1 site), and the Little Powder River in a rangeland area (1 site). Water-quality sampling frequency generally was at least monthly and included field measurements and laboratory analyses of fecal-indicator bacteria, major ions, dissolved solids, nutrients, trace elements, pesticides, and suspended sediment. Median concentrations of fecal coliform and Escherichia coli were largest for basins that were predominantly rangeland and smallest for basins that were predominantly forested. Concentrations of fecal coliform and Escherichia coli significantly varied by season (p-value <0.001); the smallest median concentrations were during January?March and the largest median concentrations were during April?June. Fecal-coliform concentrations exceeded the U.S. Environmental Protection Agency recommended limit for a single sample of 400 colonies per 100 milliliters in 2.6 percent of all samples. Escherichia coli concentrations exceeded the U.S. Environmental Protection Agency recommended limit for a single sample of 298 colonies per 100 milliliters for moderate use, full-body contact recreation in 7.6 percent of all samples. Variations in water type in the basin are reflective of the diverse geologic terrain in the Yellowstone River Basin. The water type of Soda Butte Creek and the Tongue River was calcium bicarbonate. These two sites are in forested and mountainous areas where igneous rocks and Paleozoic-era and Mesozoic-era sedimentary rocks are the dominant geologic groups. The water type of the Little Powder River was sodium sulfate. The Little Powder River originates in the plains, and geology of the basin is nearly homogenous with Tertiary-period sedimentary rocks. Water type of the Yellowstone River changed from a mixed-cation bicarbonate type upstream to a mixed-cation sulfate type downstream. Dissolved-solids concentrations ranged from fairly dilute in Soda Butte Creek, which had a median concentration of 118 milligrams per liter, to concentrated in the Little Powder River, which had a median concentration of 2,840 milligrams per liter. Nutrient concentrations generally were small and reflect the relatively undeveloped conditions in the basin; however, some correlations were made with anthropogenic factors. Median dissolved-nitrate concentrations in all samples from the fixed sites ranged from 0.04 milligram per liter to 0.54 milligram per liter. Flow-weighted mean dissolved-nitrate concentrations were positively correlated with increasing agricultural land use and rangeland on alluvial deposits upstream from the sites and negatively correlated with increasing forested land. Ammonia concentrations generally were largest in samples collected from the Yellowstone River at Corwin Springs, Montana, which is downstream from Yellowstone National Park and receives discharge from geothermal waters that are high in ammonia. Median total-phosphorus concentrations ranged from 0.007 to 0.18 milligram per liter. Median total-phosphorus concentrations exceeded the U.S. Environmental Protection Agency's recommended goal of 0.10 milligram per liter for preventing nuisance plant growth for samples collec

Scientific Investigations Report↗