Geology topics

Marshall L. Williams

Publications and source records attributed to Marshall L. Williams.

13 recordsLinked to original sources

USGS2018

Spatial and temporal trends in selenium in the upper Blackfoot River watershed, southeastern Idaho, 2001–16

Phosphate mining in southeastern Idaho has been an important economic driver for the region and State for over 100 years, but weathering of mining waste rock has also released selenium into the Blackfoot River. This report analyzes and presents data from three separate but complementary studies monitoring selenium in streams in the region. The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management, has been collecting streamflow and water-quality samples year-round on the Blackfoot River above reservoir near Henry, Idaho, (USGS streamgage 13063000) since 2001. Over the same period, the Idaho Department of Environmental Quality (IDEQ) has collected streamflow and water-quality samples from the Blackfoot River and tributaries during spring runoff. Data collected from 2001 to 2012 during these two studies were analyzed previously. This report extends the analysis using new data collected through 2016. This report also presents the results of a joint USGS and IDEQ seepage study conducted in June 2016 in the Blackfoot River near Dry Valley. Although limited in scope, this study explored the hypothesis that unaccounted selenium loading (loading in excess of tributary inputs) in this reach could be caused by groundwater inflow. USGS dissolved selenium concentration data from streamgage 13063000 on the Blackfoot River and IDEQ data from the mainstem and mining-affected tributaries are highest shortly after peak runoff and correlate with streamflow magnitude. Although earlier analyses indicated increasing selenium concentrations from 2001 to 2012, this study shows that runoff and baseflow dissolved selenium concentrations increased and then decreased during 2001–16. High median runoff concentrations from 2005 through 2011 are associated with high snowpack and streamflow. This result suggests that more snowmelt moving through selenium-bearing waste rock leads to increased instream concentrations. The time lag between peak runoff and then peak selenium concentrations suggests that selenium mobilization may occur as snowmelt percolates through waste rock rather than by faster surface runoff. However, variability in local snow accumulation and snowmelt conditions likely affects interannual variability in selenium concentrations in the mainstem Blackfoot River and tributaries. In contrast to runoff selenium concentrations, median baseflow (August to October) dissolved selenium concentrations were highest from 2009 to 2013. Aquatic plant senescence and release of selenium is an unlikely explanation for this trend because plants are still growing during this time of year. In addition, this trend is observed during and shortly after the observed period of high snowpack. Thus, increased baseflow selenium concentrations suggest that increased selenium loading to alluvial groundwater may occur during periods of high snowmelt and manifest in later years as higher instream concentrations during baseflows when the majority of streamflow is attributable to groundwater gains. Runoff-period streamflow and selenium loads were calculated for the tributaries and mainstem Blackfoot River. Selenium loads vary from year to year with mainstem loads greater than the total tributary contributions in some years and less than tributary contributions in other years. In general, East Mill Creek usually accounted for the largest proportion of the total Blackfoot River load, and unaccounted loads (loads in excess of tributary inputs) often occurred in the vicinity of Spring Creek and Dry Valley. The latter observation led the USGS and IDEQ to conduct a seepage study to further investigate groundwater and selenium loading to the Blackfoot River near Dry Valley. The seepage study results show consistent albeit small unaccounted increases in streamflow and dissolved selenium load in the Blackfoot River near Dry Valley. Field observation of a spring to the north of the river and independent groundwater monitoring data from Dry Valley to the south of the river suggest that alluvial groundwater may discharge to the river from both sides. However, the small unaccounted selenium load measured in the June 2016 study relative to loads measured during runoff suggest that groundwater loading in this reach may occur primarily during runoff. An improved understanding of alluvial groundwater extent, gradient, hydraulic conductivity, and quality would aid in interpreting unaccounted gains and losses in selenium loads in the Blackfoot River. Finally, State of Idaho selenium water-quality criteria have recently shifted to a hierarchical fish tissue and water concentration scheme. This report summarizes existing fish tissue and water-quality data in the mainstem and offers considerations for future selenium monitoring in the Blackfoot River.

Idaho↗

USGS2016

Mercury concentrations in water and mercury and selenium concentrations in fish from Brownlee Reservoir and selected sites in the Boise and Snake Rivers, Idaho and Oregon, 2013–15

Mercury (Hg) analyses were conducted on samples of sport fish and water collected from selected sampling sites in Brownlee Reservoir and the Boise and Snake Rivers to meet National Pollution Discharge and Elimination System (NPDES) permit requirements for the City of Boise, Idaho, between 2013 and 2015. City of Boise personnel collected water samples from six sites between October and November 2013 and 2015, with one site sampled in 2014. Total Hg concentrations in unfiltered water samples ranged from 0.48 to 8.8 nanograms per liter (ng/L), with the highest value in Brownlee Reservoir in 2013. All Hg concentrations in water samples were less than the U.S. Environmental Protection Agency (USEPA) Hg chronic aquatic life criterion of 12 ng/L. The USEPA recommended a water-quality criterion of 0.30 milligrams per kilogram (mg/kg) methylmercury (MeHg) expressed as a fish-tissue residue value (wet-weight MeHg in fish tissue). The Idaho Department of Environmental Quality adopted the USEPA’s fish-tissue criterion and established a reasonable potential to exceed (RPTE) threshold 20 percent lower than the criterion or greater than 0.24 mg/kg Hg based on an average concentration of 10 fish from a receiving waterbody. NPDES permitted discharge to waters with fish having Hg concentrations exceeding 0.24 mg/kg are said to have a reasonable potential to exceed the water-quality criterion and thus are subject to additional permit obligations, such as requirements for increased monitoring and the development of a Hg minimization plan. The Idaho Fish Consumption Advisory Program (IFCAP) issues fish advisories to protect general and sensitive populations of fish consumers and has developed an action level of 0.22 mg/kg Hg in fish tissue. Fish consumption advisories are water body- and species-specific and are used to advise allowable fish consumption from specific water bodies. The geometric mean Hg concentration of 10 fish of a single species collected from a single water body (lake or stream) in Idaho is compared to the action level to determine if a fish consumption advisory should be issued. The U.S. Geological Survey collected and analyzed individual fillets of mountain whitefish ( Prosopium williamsoni ), rainbow trout ( Oncorhynchus mykiss ), smallmouth bass ( Micropterus dolomieu ), and channel catfish ( Ictalurus punctatus ) for Hg. The 2013 average Hg concentration for small mouth bass (0.32 mg/kg) collected at Brownlee Reservoir and for channel catfish (0.33 mg/kg) collected at the Boise River mouth, exceeded the Idaho water quality criterion (>0.3 mg/kg), the Hg RPTE threshold (>0.24 mg/kg), and the IFCAP action level (>0.22 mg/kg). Average Hg concentrations in fish collected in 2014 or 2015 did not exceed evaluation criteria for any of the species assessed. Selenium (Se) analysis was conducted on one composite fish tissue sample per site to assess general concentrations and to provide information for future risk assessments. Composite concentrations of Se in fish tissue collected between 2013 and 2015 ranged from 0.07 and 0.49 mg/kg wet weight with the highest concentration collected from smallmouth bass from the Snake River near Murphy, and the lowest from mountain whitefish from the Boise River at Eckert Road.

Idaho↗

USGS2015

Evaluation of mercury in rainbow trout collected from Duck Valley Indian Reservation reservoirs, southwestern Idaho and northern Nevada, 2007, 2009, and 2013

The U.S. Geological Survey, in cooperation with the Shoshone-Paiute Tribes of the Duck Valley Indian Reservation, analyzed mercury (Hg) concentration in rainbow trout ( Oncorhynchus mykiss ) collected from three reservoirs on the reservation (Mountain View, Lake Billy Shaw, and Sheep Creek) during sampling events in 2007, 2009, and 2013, to determine the risk of Hg exposure to Tribal members and the general public. Mercury concentration in predatory fish tends to increase with fish length, and this tendency was true for rainbow trout in the reservoirs on the reservation (r 2 = 0.44–0.70). Mean (average) and median Hg concentrations in fish tissue were determined for each reservoir for each sample year. All Hg concentrations were less than the U.S. Environmental Protection Agency’s water-quality criterion of 0.30 milligram per kilogram (mg/kg wet weight [ww]) and the Idaho Department of Environmental Quality’s reasonable potential to exceed threshold of 0.24 mg/kg. Idaho Department of Health and Welfare toxicologists determined that the Hg concentrations in rainbow trout in this study would not warrant a fish-consumption advisory for this species. Throughout this report, statistical findings with a p -value of less than 0.05 are referred to as “significant.” Mean Hg concentrations in fish-tissue samples collected from Mountain View Reservoir were higher in 2007 (0.12 mg/kg ww) than in 2009 and 2013 (0.07 and 0.06 mg/kg ww, respectively), indicating a significant mean decrease. Mean Hg concentrations in fish-tissue samples collected from Lake Billy Shaw showed no significant differences among sample years (2007, 0.12 mg/kg ww; 2009, 0.07 mg/kg ww; 2013, 0.09 mg/kg ww). Mean Hg concentrations in fish-tissue samples collected from Sheep Creek Reservoir significantly increased in 2013 (0.10 mg/kg ww) from concentrations in 2007 and 2009 (0.06 and 0.05 mg/kg ww, respectively). These temporal and spatial variations are not unexpected, as each body of water may differ in the factors and conditions affecting the rate of methylation and demethylation. Coupled with the dynamic put-and-take fishery, the outcomes reflect the system complexities among reservoirs despite their fairly close proximity to one another. The influence of these other factors is evident when the analysis of atmospheric Hg deposition at Mercury Deposition Network site NV02 in northern Nevada showed no significant linear trend in wet Hg deposition rates for 2003–2013 (average 3.02 micrograms per square meter).

Idaho, Nevada↗

USGS2014

Selenium in the upper Blackfoot River watershed, southeastern Idaho, 2001-12

The upper Blackfoot River in southeastern Idaho receives runoff from 12 large phosphate mines. Waste shales that are removed to access the phosphate ore are highly enriched with selenium, resulting in elevated selenium in runoff from the mine waste dumps. In 2001, in cooperation with the Bureau of Land Management, the U.S. Geological Survey (USGS) began monitoring streamflow, selenium, and other water-quality parameters at a single location near the outlet of the upper Blackfoot River to the Blackfoot Reservoir. Water samples primarily were collected by a flow triggered, automated pump sampler, supplemented by manual point and equal-width integrated manual samples. The approach to monitoring concentrations and streamflow over time at a fixed location is ideal for evaluating temporal trends, but provides no information about the relative source contributions from the mine waste dumps draining into various tributaries. In 2001, the Idaho Department of Environmental Quality (IDEQ) began an annual, mid-May, synoptic survey of selenium concentrations and streamflow at 21 locations along the main stem Blackfoot River and its tributaries. Individually, neither the intensive USGS sampling at the outlet nor the IDEQ annual synoptic sampling provides a comprehensive view of selenium runoff in the Blackfoot River watershed. Together, the efforts are complementary; therefore, in this report, results are presented from both sampling efforts. The USGS collected time-series data from 2001 to 2012 at a fixed location, the Blackfoot River near the outlet of the reservoir, near Henry, Idaho (USGS streamgage 13063000). Dissolved selenium concentrations from 450 filtered samples collected at this site ranged from 0.5 to 11.4 micrograms per liter (μg/L). The State of Idaho chronic aquatic life criterion concentration of 5 μg/L was exceeded in 31 percent of the samples, with most exceedances occurring during May of each year. No exceedances of the selenium criterion were recorded in months other than April, May, or June. Concentrations of selenium in unfiltered and filtered samples were similar, and concentrations from samples collected by depth and width integrated methods were similar to those collected by grab (point) samples, indicating that the grab samples adequately represent selenium concentrations across the entire river cross section. In speciation analyses made during 2003 and 2004, the median percentage of total selenium as selenate was 81 percent, ranging from 17 to 98 percent, and the median percentage of total selenium as selenite was 19 percent, ranging from 2 to 83 percent of the total selenium. During the period of study, selenium concentrations had an upward trend during the lowflow season of August–October. Time trends were not obvious during other seasons. Selenium daily loads varied by more than a factor of 900 during the study period and ranged from 0.03 kilograms per day (kg/d) to more than 24 kg/d. Annual maximum daily loads of selenium varied over nearly a factor of 12, ranging from about 2 to 24 kg/d. For the annual spring synoptic samples collected by the IDEQ along the main stem Blackfoot River and major tributaries, selenium concentrations ranged from less than 2 to 870 μg/L in 176 samples. In most years, the synoptic sampling showed that the majority of the selenium loads passing the USGS streamgage at the outlet of the watershed could be attributed to a single tributary, East Mill Creek, which enters the Blackfoot River through Spring Creek. Selenium loads decreased by about half from East Mill Creek before reaching the Blackfoot River, suggesting that much selenium is at least temporarily removed from the water column by uptake by aquatic vegetation or by losses to sediment. Similar decreases in selenium loads occurred through the main stem Blackfoot River before reaching the outlet in low flow years, but not in high flow years.

Idaho↗

USGS2014

Groundwater level and nitrate concentration trends on Mountain Home Air Force Base, southwestern Idaho

Mountain Home Air Force Base in southwestern Idaho draws most of its drinking water from the regional aquifer. The base is located within the State of Idaho's Mountain Home Groundwater Management Area and is adjacent to the State's Cinder Cone Butte Critical Groundwater Area. Both areas were established by the Idaho Department of Water Resources in the early 1980s because of declining water levels in the regional aquifer. The base also is listed by the Idaho Department of Environmental Quality as a nitrate priority area. The U.S. Geological Survey, in cooperation with the U.S. Air Force, began monitoring wells on the base in 1985, and currently monitors 25 wells for water levels and 17 wells for water quality, primarily nutrients. This report provides a summary of water-level and nitrate concentration data collected primarily between 2001 and 2013 and examines trends in those data. A Regional Kendall Test was run to combine results from all wells to determine an overall regional trend in water level. Groundwater levels declined at an average rate of about 1.08 feet per year. Nitrate concentration trends show that 3 wells (18 percent) are increasing in nitrate concentration trend, 3 wells (18 percent) show a decreasing nitrate concentration trend, and 11 wells (64 percent) show no nitrate concentration trend. Six wells (35 percent) currently exceed the U.S. Environmental Protection Agency's maximum contaminant limit of 10 milligrams per liter for nitrate (nitrite plus nitrate, measured as nitrogen).

Idaho↗

USGS2014

Evaluation of seepage and discharge uncertainty in the middle Snake River, southwestern Idaho

The U.S. Geological Survey, in cooperation with the State of Idaho, Idaho Power Company, and the Idaho Department of Water Resources, evaluated seasonal seepage gains and losses in selected reaches of the middle Snake River, Idaho, during November 2012 and July 2013, and uncertainty in measured and computed discharge at four Idaho Power Company streamgages. Results from this investigation will be used by resource managers in developing a protocol to calculate and report Adjusted Average Daily Flow at the Idaho Power Company streamgage on the Snake River below Swan Falls Dam, near Murphy, Idaho, which is the measurement point for distributing water to owners of hydropower and minimum flow water rights in the middle Snake River. The evaluated reaches of the Snake River were from King Hill to Murphy, Idaho, for the seepage studies and downstream of Lower Salmon Falls Dam to Murphy, Idaho, for evaluations of discharge uncertainty. Computed seepage was greater than cumulative measurement uncertainty for subreaches along the middle Snake River during November 2012, the non-irrigation season, but not during July 2013, the irrigation season. During the November 2012 seepage study, the subreach between King Hill and C J Strike Dam had a meaningful (greater than cumulative measurement uncertainty) seepage gain of 415 cubic feet per second (ft 3 /s), and the subreach between Loveridge Bridge and C J Strike Dam had a meaningful seepage gain of 217 ft 3 /s. The meaningful seepage gain measured in the November 2012 seepage study was expected on the basis of several small seeps and springs present along the subreach, regional groundwater table contour maps, and results of regional groundwater flow model simulations. Computed seepage along the subreach from C J Strike Dam to Murphy was less than cumulative measurement uncertainty during November 2012 and July 2013; therefore, seepage cannot be quantified with certainty along this subreach. For the uncertainty evaluation, average uncertainty in discharge measurements at the four Idaho Power Company streamgages in the study reach ranged from 4.3 percent (Snake River below Lower Salmon Falls Dam) to 7.8 percent (Snake River below C J Strike Dam) for discharges less than 7,000 ft3/s in water years 2007–11. This range in uncertainty constituted most of the total quantifiable uncertainty in computed discharge, represented by prediction intervals calculated from the discharge rating of each streamgage. Uncertainty in computed discharge in the Snake River below Swan Falls Dam near Murphy was 10.1 and 6.0 percent at the Adjusted Average Daily Flow thresholds of 3,900 and 5,600 ft3/s, respectively. All discharge measurements and records computed at streamgages have some level of uncertainty that cannot be entirely eliminated. Knowledge of uncertainty at the Adjusted Average Daily Flow thresholds is useful for developing a measurement and reporting protocol for purposes of distributing water to hydropower and minimum flow water rights in the middle Snake River.

Idaho↗

USGS2013

An evaluation of seepage gains and losses in Indian Creek Reservoir, Ada County, Idaho, April 2010–November 2011

The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources, conducted an investigation on Indian Creek Reservoir, a small impoundment in east Ada County, Idaho, to quantify groundwater seepage into and out of the reservoir. Data from the study will assist the Idaho Water Resources Department’s Comprehensive Aquifer Management Planning effort to estimate available water resources in Ada County. Three independent methods were utilized to estimate groundwater seepage: (1) the water-budget method; (2) the seepage-meter method; and (3) the segmented Darcy method. Reservoir seepage was quantified during the periods of April through August 2010 and February through November 2011. With the water-budget method, all measureable sources of inflow to and outflow from the reservoir were quantified, with the exception of groundwater; the water-budget equation was solved for groundwater inflow to or outflow from the reservoir. The seepage-meter method relies on the placement of seepage meters into the bottom sediments of the reservoir for the direct measurement of water flux across the sediment-water interface. The segmented-Darcy method utilizes a combination of water-level measurements in the reservoir and in adjacent near-shore wells to calculate water-table gradients between the wells and the reservoir within defined segments of the reservoir shoreline. The Darcy equation was used to calculate groundwater inflow to and outflow from the reservoir. Water-budget results provided continuous, daily estimates of seepage over the full period of data collection, while the seepage-meter and segmented Darcy methods provided instantaneous estimates of seepage. As a result of these and other difference in methodologies, comparisons of seepage estimates provided by the three methods are considered semi-quantitative. The results of the water-budget derived estimates of seepage indicate seepage to be seasonally variable in terms of the direction and magnitude of flow. The reservoir tended to gain water from seepage of groundwater in the early spring months (March–May), while seepage losses to groundwater from the reservoir occurred in the drier months (June–October). Net monthly seepage rates, as computed by the water-budget method, varied greatly. Reservoir gains from seepage ranged from 0.2 to 59.4 acre-feet per month, while reservoir losses to seepage ranged from 1.6 and 26.8 acre-feet per month. An analysis of seepage meter estimates and segmented-Darcy estimates qualitatively supports the seasonal patterns in seepage provided by the water-budget calculations, except that they tended to be much smaller in magnitude. This suggests that actual seepage might be smaller than those estimates made by the water-budget method. Although the results of all three methods indicate that there is some water loss from the reservoir to groundwater, the seepage losses may be due to rewetting of unsaturated near-shore soils, possible replenishment of a perched aquifer, or both, rather than through percolation to the local aquifer that lies 130 feet below the reservoir. A lithologic log from an adjacent well indicates the existence of a clay lithology that is well correlated to the original reservoir’s base elevation. If the clay lithologic unit extends beneath the reservoir basin underlying the fine-grain reservoir bed sediments, the clay layer should act as an effective barrier to reservoir seepage to the local aquifer, which would explain the low seepage loss estimates calculated in this study.

Idaho↗

USGS2012

Sediment cores and chemistry for the Kootenai River White Sturgeon Habitat Restoration Project, Boundary County, Idaho

The Kootenai Tribe of Idaho, in cooperation with local, State, Federal, and Canadian agency co-managers and scientists, is assessing the feasibility of a Kootenai River habitat restoration project in Boundary County, Idaho. This project is oriented toward recovery of the endangered Kootenai River white sturgeon (Acipenser transmontanus) population, and simultaneously targets habitat-based recovery of other native river biota. Projects currently (2010) under consideration include modifying the channel and flood plain, installing in-stream structures, and creating wetlands to improve the physical and biological functions of the ecosystem. River restoration is a complex undertaking that requires a thorough understanding of the river. To assist in evaluating the feasibility of this endeavor, the U.S. Geological Survey collected and analyzed the physical and chemical nature of sediment cores collected at 24 locations in the river. Core depths ranged from 4.6 to 15.2 meters; 21 cores reached a depth of 15.2 meters. The sediment was screened for the presence of chemical constituents that could have harmful effects if released during restoration activities. The analysis shows that concentrations of harmful chemical constituents do not exceed guideline limits that were published by the U.S. Army Corps of Engineers in 2006.

Idaho↗

USGS2012

Bathymetric and underwater video survey of Lower Granite Reservoir and vicinity, Washington and Idaho, 2009-10

The U.S. Geological Survey conducted a bathymetric survey of the Lower Granite Reservoir, Washington, using a multibeam echosounder, and an underwater video mapping survey during autumn 2009 and winter 2010. The surveys were conducted as part of the U.S. Army Corps of Engineer's study on sediment deposition and control in the reservoir. The multibeam echosounder survey was performed in 1-mile increments between river mile (RM) 130 and 142 on the Snake River, and between RM 0 and 2 on the Clearwater River. The result of the survey is a digital elevation dataset in ASCII coordinate positioning data (easting, northing, and elevation) useful in rendering a 3×3-foot point grid showing bed elevation and reservoir geomorphology. The underwater video mapping survey was conducted from RM 107.73 to 141.78 on the Snake River and RM 0 to 1.66 on the Clearwater River, along 61 U.S. Army Corps of Engineers established cross sections, and dredge material deposit transects. More than 900 videos and 90 bank photographs were used to characterize the sediment facies and ground-truth the multibeam echosounder data. Combined, the surveys were used to create a surficial sediment facies map that displays type of substrate, level of embeddedness, and presence of silt.

Washington;Idaho↗

USGS2012

Grain-size distribution and selected major and trace element concentrations in bed-sediment cores from the Lower Granite Reservoir and Snake and Clearwater Rivers, eastern Washington and northern Idaho, 2010

Lower Granite Dam impounds the Snake and Clearwater Rivers in eastern Washington and northern Idaho, forming Lower Granite Reservoir. Since 1975, the U.S. Army Corps of Engineers has dredged sediment from the Lower Granite Reservoir and the Snake and Clearwater Rivers in eastern Washington and northern Idaho to keep navigation channels clear and to maintain the flow capacity. In recent years, other Federal agencies, Native American governments, and special interest groups have questioned the negative effects that dredging might have on threatened or endangered species. To help address these concerns, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, collected and analyzed bed-sediment core samples (hereinafter cores) in Lower Granite Reservoir and impounded or backwater affected parts of the Snake and Clearwater Rivers. Cores were collected during the spring and fall of 2010 from submerged sampling locations in the Lower Granite Reservoir, and Snake and Clearwater Rivers. A total of 69 cores were collected by using one or more of the following corers: piston, gravity, vibrating, or box. From these 69 cores, 185 subsamples were removed and submitted for grain size analyses, 50 of which were surficial-sediment subsamples. Fifty subsamples were also submitted for major and trace elemental analyses. Surficial-sediment subsamples from cores collected from sites at the lower end of the reservoir near the dam, where stream velocities are lower, generally had the largest percentages of silt and clay (more than 80 percent). Conversely, all of the surficial-sediment subsamples collected from sites in the Snake River had less than 20 percent silt and clay. Most of the surficial-sediment subsamples collected from sites in the Clearwater River contained less than 40 percent silt and clay. Surficial-sediment subsamples collected near midchannel at the confluence generally had more silt and clay than most surficial-sediment subsamples collected from sites on the Snake and Clearwater Rivers or even sites further downstream in Lower Granite Reservoir. Two cores collected at the confluence and all three cores collected on the Clearwater River immediately upstream from the confluence were extracted from a thick sediment deposit as shown by the cross section generated from the bathymetric surveys. The thick sediment deposits at the confluence and on the Clearwater River may be associated with floods in 1996 and 1997 on the Clearwater River. Fifty subsamples from 15 cores were analyzed for major and trace elements. Concentrations of trace elements were low, with respect to sediment quality guidelines, in most cores. Typically, major and trace element concentrations were lower in the subsamples collected from the Snake River compared to those collected from the Clearwater River, the confluence of the Snake and Clearwater Rivers, and Lower Granite Reservoir. Generally, lower concentrations of major and trace elements were associated with coarser sediments (larger than 0.0625 millimeter) and higher concentrations of major and trace elements were associated with finer sediments (smaller than 0.0625 millimeter).

Idaho, Washington↗

USGS2011

Bathymetric and sediment facies maps for China Bend and Marcus Flats, Franklin D. Roosevelt Lake, Washington, 2008 and 2009

The U.S. Geological Survey (USGS) created bathymetric and sediment facies maps for portions of two reaches of Lake Roosevelt in support of an interdisciplinary study of white sturgeon (Acipenser transmontanus) and their habitat areas within Franklin D. Roosevelt Lake, Washington. In October 2008, scientists from the USGS used a boat-mounted multibeam echo sounder (MBES) to describe bathymetric data to characterize surface relief at China Bend and Marcus Flats, between Northport and Kettle Falls, Washington. In March 2009, an underwater video camera was used to view and record sediment facies that were then characterized by sediment type, grain size, and areas of sand deposition. Smelter slag has been identified as having the characteristics of sand-sized black particles; the two non-invasive surveys attempted to identify areas containing black-colored particulate matter that may be elements and minerals, organic material, or slag. The white sturgeon population in Lake Roosevelt is threatened by the failure of natural recruitment, resulting in a native population that consists primarily of aging fish and that is gradually declining as fish die and are not replaced by nonhatchery reared juvenile fish. These fish spawn and rear in the riverine and upper reservoir reaches where smelter slag is present in the sediment of the river lake bed. Effects of slag on the white sturgeon population in Lake Roosevelt are largely unknown. Two recent studies demonstrated that copper and other metals are mobilized from slag in aqueous environments with concentrations of copper and zinc in bed sediments reaching levels of 10,000 and 30,000 mg/kg due to the presence of smelter slag. Copper was found to be highly toxic to 30-day-old white sturgeon with 96-h LC50 concentrations ranging from 3 to 5 (u or mu)g copper per liter. Older juvenile and adult sturgeons commonly ingest substantial amounts of sediment while foraging. Future study efforts in Lake Roosevelt should include sampling of bottom material to confirm the presence or absence of slag material indicated on the map. In addition, follow-up acoustic work to determine stream velocities at varying discharges, in conjunction with sediment mapping, would be helpful to more accurately identify areas of scour and areas of sediment deposition where slag deposits may accumulate within the Marcus Flats and China Bend reaches. MBES mapping could also be used to determine changes in bed elevation and sedimentation in the study reaches and could help evaluate annual deposition and provide estimates on fine-sediment thickness.

Washington↗

USGS2011

Seasonal seepage investigation on an urbanized reach of the lower Boise River, southwestern Idaho, water year 2010

The U.S. Geological Survey in cooperation with the Idaho Department of Water Resources Treasure Valley Comprehensive Aquifer Management Planning effort investigated seasonal groundwater gains and losses on the Boise River, Idaho, starting in November 2009 through August 2010. The investigation was conducted using seepage runs in 11 subreaches over a 14-mile reach from downstream of the inactive streamgage, Boise River below Diversion Dam (U.S. Geological Survey station No. 13203510) to the active Boise River at Glenwood Bridge streamgage (U.S. Geological Survey station No. 13206000). The seepage runs measured mainstem discharge, and significant tributary contributions and diversions along the reach. In addition, an evaluation of the groundwater hydraulic gradient was simultaneously conducted through shallow groundwater mini-piezometers adjacent to the river during February (low stream discharge) and May (high stream discharge) measurement timeframes. November discharge estimates, representative of autumn, had gains and losses that varied by subreach with an overall net gain of 42 ± 8 cubic feet per second (ft 3 /s). This finding compares favorably to a previous U.S. Geological Survey seepage investigation in November 1996 that found a gaining reach with an estimated gain of 52 ft 3 /s. This finding also is supported by a U.S. Geological Survey investigation in the study reach in November 1971 that estimated a gain of 74 ft 3 /s, which largely came from groundwater. The February discharge estimates, representative of winter conditions, showed variability in the reach with a net gain of 52 ft 3 /s with an uncertainty estimate of ± 7 ft 3 /s, which is consistent with the low stream discharge findings from November 2009. This finding is further supported by the differential hydraulic head measured at transect sites that qualitatively indicated groundwater to surface-water movement with few exceptions. The May discharge estimates, representative of the spring-time conditions, were gaining or potentially gaining in all but one of the upper subreaches between Boise River below Diversion Dam and Boise River near MK Nature Center sites, with seepage run results supported by hydraulic head differentials indicating a groundwater to surface-water movement. The lower end of the study reach between Boise River near MK Nature Center and Boise River at Glenwood Bridge sites showed more variability with observed hydraulic head differentials that partially supported the potential gains or losses in the reach. Overall, the reach had a calculated net gain of 24 ± 51 ft 3 /s and, therefore, this estimate may or may not reflect the actual conditions in the reach. The groundwater gains and losses in August, representative of summer conditions, varied in both the upper and lower parts of the reach, with a net loss of -88 ± 69 ft 3 /s. Overall, the reach experienced a net gain from groundwater at low stream discharges (November and February), a net loss to groundwater at moderately high stream discharge (August), and an ambiguous finding at a higher stream discharge (May). The hydraulic head differentials measured between the groundwater and surface water largely supported the calculated gain and loss estimates in the subreaches, with a potential for groundwater to surface-water movement at low stream discharge in February, and variability during high stream discharge conditions in May.

Scientific Investigations Report↗

USGS2009

Sediment Characteristics and Transport in the Kootenai River White Sturgeon Critical Habitat near Bonners Ferry, Idaho

Recovery efforts for the endangered Kootenai River population of white sturgeon require an understanding of the characteristics and transport of suspended and bedload sediment in the critical habitat reach of the river. In 2007 and 2008, the U.S. Geological Survey in cooperation with the Kootenai Tribe of Idaho, conducted suspended- and bedload-sediment sampling in the federally designated critical habitat of the endangered Kootenai River white sturgeon population. Three sediment-sampling sites were selected that represent the hydraulic differences in the critical habitat. Suspended- and bedload-sediment samples along with acoustic Doppler current profiles were collected at these sites during specific river discharges. Samples were analyzed to determine suspended- and bedload-sediment characteristics and transport rates. Sediment transport data were analyzed to provide total loading estimates for suspended and bedload sediment in the critical habitat reach. Total suspended-sediment discharge primarily occurred as fine material that moved through the system in suspension. Total suspended-sediment discharge ranged from about 300 metric tons per day to more than 23,000 metric tons per day. Total suspended sediment remained nearly equal throughout the critical habitat, with the exception of a few cases where mass wasting of the banks may have caused sporadic spikes in total suspended sediment. Bedload-sediment discharge averaged 0-3 percent of the total loading. These bedload discharges ranged from 0 to 271 tons per day. The bedload discharge in the upper part of the critical habitat primarily consisted of fine to coarse gravel. A decrease in river competence in addition to an armored channel may be the cause of this limited bedload discharge. The bedload discharge in the middle part of the white sturgeon critical habitat varied greatly, depending on the extent of the backwater from Kootenay Lake. A large quantity of fine-to-coarse gravel is present in the braided reach, but the duration of transport for these gravels is limited by the encroaching backwater of Kootenay Lake. Bedload discharge in the lower part of the white sturgeon critical habitat primarily consisted of fine to coarse sand due to decreased velocities as a result of the backwater from Kootenay Lake.

Scientific Investigations Report↗