Southeastern Washington Research Articles

EVALUATION OF THE EFFICACY OF POLYPHOSPHATE REMEDIATION TECHNOLOGY: DIRECT AND INDIRECT REMEDIATION OF URANIUM UNDER ALKALINE CONDITIONS

A field-scale technology demonstration has been conducted to optimize polyphosphate remediation technology for enhanced monitored natural attenuation of the uranium plume within the 300 Area aquifer at the Hanford Site, southeastern Washington State. The objective was to evaluate the efficacy of polyphosphate to treat uranium-contaminated groundwater in situ. Focused application of polyphosphate was conducted in a source or 'hot spot' area to reduce the inventory of available uranium contributing to the groundwater plume through direct precipitation of uranyl-phosphate solids and secondary containment via precipitation of apatite which can serve as a long-term sorbent for uranium. The test site consisted of an injection well and 15 monitoring wells installed in the 300 Area near the process trenches that had previously received uranium-bearing effluents. The results indicated sequestration of uranium as insoluble phosphate phases appears to be a promising alternative for treating the uranium- contaminated groundwater at the Hanford Site 300 Area. However, the formation of the apatite during the test was limited due to two separate overarching issues: (1) formation and emplacement of apatite via polyphosphate technology, and (2) efficacy of apatite for sequestering uranium under the present geochemical and hydrodynamic conditions.

The Wallula basalt sequestration pilot project

Abstract The U.S. Department of Energy Big Sky Regional Carbon Sequestration Partnership completed drilling the world’s first continental flood basalt sequestration pilot borehole to a total depth (TD) of 1253 m at a paper mill site near the town of Wallula located in Southeastern Washington State. Site suitability was assessed prior to drilling by acquisition, processing and analysis of a four-mile, five-line, three component seismic swath, which was processed as a single data-dense line. Analysis of the seismic survey data indicated absence of major geologic structures that would preclude CO2 injection at the site. Drilling of Wallula pilot borehole was initiated on January 13, 2009 and reached TD on April 6, 2009. Hydrogeologic information was obtained primarily during borehole drilling/advancement utilizing a progressive drill-and-test characterization strategy. A general decreasing transmissivity trend with depth pattern was observed, which is consistent with results exhibited for Columbia River basalt interflow zones at a number of other deep wells in the region. Based on the comparative results from 10 test intervals, a candidate injection test zone was identified between the general depth interval of ∼828 and 875 m bgs. Over this interval, three brecciated interflow zones were intersected and isolated for CO2 injection. The flow tops have moderate permeability (75 to 150 millidarcies) and are bounded by thick flow interiors that have extremely low (microdarcy) permeability. The borehole configuration established at the Wallula pilot site provides a unique opportunity to scientifically study the reservoir behaviour of three connected reservoir intervals confined between primary and secondary caprock zones. The permitting process for the CO2 injection has proceeded in accordance with formal rules for geologic sequestration projects enacted in June 2008 into the underground injection control program administered by the Washington State Department of Ecology. The permitting process is expected to conclude in October 2010 and injection would begin soon thereafter. Post-injection monitoring includes long-term sampling of water retrieved from the injection zone, shallow groundwater and soil gas monitoring, and PSInSAR.

Landscape-level effects on cynipid component communities of “orphaned” native shrubs

Native plants that persist in agricultural landscapes can be important for conserving and re-connecting fragmented biological communities, particularly to arthropods that live in and on them. However, their value as habitat may depend upon landscape context, which can differently impact species among trophic levels. We examined the communities of gall-inducing cynipid wasps and their parasitoids associated with a native wild rose, Rosa woodsii, in the Palouse region of southeastern Washington State and adjacent Idaho, to determine how this arthropod community varies with the landscape context of the host plant. Nine species of gall wasps (Diplolepis spp.), 11 species of parasitoids, and the inquiline cynipid, Periclistus sp. were sampled from R. woodsii shrubs throughout the Palouse region. We examined whether any gall-inducing cynipids were absent from R. woodsii in particular landscape contexts. We tested the relationship between community structure and landscape variables including landscape diversity and the proportion of prairie, agriculture, introduced grasslands, and built environments. All gall-inducer species occurred in every landscape context, although some species were more common on roses within prairie remnants. Gall-inducer and parasitoid species richness was positively correlated with the proportion of prairie in the landscape at radii from 100 to 1,500 m, with the scale of this effect differing between the two sample years. Landscape diversity had little or no effect on species richness. These results suggest that although R. woodsii supports diverse arthropod communities throughout a fragmented landscape, its greatest conservation potential will be realized if prairie remnants are conserved as well.

Paleoecological and biogeographical implications of late Pleistocene noble marten ( Martes americana nobilis) in eastern Washington State, USA

A mandible identified as noble marten ( Martes americana nobilis) recovered from sediments dating to 11,800 cal yr BP and a humerus identified as M. a. cf. nobilis recovered from sediments dating from 13,100 to 12,500 cal yr BP at the Marmes Rockshelter archaeological site in southeastern Washington represent the first record of this taxon in the state. Mammalian taxa associated with the Marmes Rockshelter noble marten represent a diversity of open mesic habitats corroborating earlier analyses of other records of the noble marten in the western United States and exemplify how paleozoologists determine the ecology and environmental predilections of extinct taxa. The recovery site represents the topographically lowest record of this species in western North America and the farthest north record in the United States. Future research should examine known late-Quaternary Martes spp. remains from British Columbia and Alberta to fill in the 2200-km geographic gap in the known distribution of this taxon between a record in the northern Yukon and those in the western United States, and to refine our knowledge of noble marten paleoecology.

Taphonomy, pathology, and paleoecology of the terminal Pleistocene Marmes Rockshelter (45FR50) “big elk” (Cervus elaphus), southeastern Washington State, USA

In 1968, remains of what were reported to be a larger-than-modern elk ( Cervus elaphus ) were recovered from terminal Pleistocene sediments associated with the Marmes Rockshelter archaeological site in southeastern Washington State. Originally thought to have been butchered by humans, it is associated with radiocarbon dates suggesting an age of about 980014C years B.P. Taphonomic analysis in 2009 indicates the elk likely died of natural causes during winter months; it was lightly scavenged by carnivores prior to burial from silt-rich spring runoff. The elk suffered from two pathological conditions: one resulting in fusion of the fourth and fifth cervical vertebrae, and the other resulting in excessive bone tissue on the proximal ends of the first ribs, seventh cervical, and first and second thoracic vertebrae. The Marmes elk is larger than modern Rocky Mountain elk ( C. e. nelsoni ) and is on the large end of the size range of modern Roosevelt elk ( C. e. roosevelti ). It is also larger than the similarly aged elk skeleton from Three Hills, Alberta. A single elk bone from the Sentinel Gap archaeological site in central Washington State, dated to about 10 20014C years BP and located 130 km west of Marmes Rockshelter, is the same size as the same bone of the Marmes elk. Terminal Pleistocene elk in eastern Washington likely grew to exceptionally large size as a result of abundant grass at the time, forage that decreased in abundance as Holocene climatic conditions developed.

Noteworthy collections: Florida

Drosera filiformis Raf. × tracyi Macf. (Droseraceae)—southeastern Washington County, Florida, elevation 20 m, 29 May 2010. Plants were found flowering on the wet borders of a low, sandy lake, with Drosera filiformis Raf. and Drosera tracyi Macf.

Engineered Surface Barrier Monitoring Using Ground‐Penetrating Radar, Time‐Domain Reflectometry, and Neutron‐Scattering Techniques

Effective monitoring of surface barriers intended to isolate and protect waste from the accessible environment requires techniques to assess their performance. Quantifying drainage conditions at any point below the barrier is difficult because field‐scale drainage measurements are not well suited for assessing spatial drainage heterogeneity. Measurements of water storage, however, can provide an indirect measure of impending drainage. We measured seasonal water content at a vegetated capillary barrier on the Hanford Site in southeastern Washington to determine effective water‐storage monitoring methods. Measurements were made using ground‐penetrating radar (GPR) direct ground wave methods operating at 100 MHz. Simultaneous measurements using time‐domain reflectometry (TDR) and neutron‐scattering probe (NP) were used to determine the sampling depth of the GPR ground wave. The ground wave sampling depth increased only slightly with decreasing moisture content, ranging from 30 to 37.5 cm. The TDR measurements were made using permanently emplaced arrays, eliminating the need for repeated ground disturbance. All three methods showed similar seasonal responses, with the highest water contents observed during the winter months and decreasing through the summer. Unlike TDR and NPs, which are local‐scale measurements, GPR exhibited much greater spatial detail across the barrier surface. While measurement uncertainties exist with regard to the sampling depth and dispersive effects, our results indicate that GPR can be an effective and minimally invasive method for providing reasonable near‐surface estimates of soil water content changes within an engineered barrier.

Development of occupational exposure limits for the Hanford tank farms

Production of plutonium for the United States’ nuclear weapons program from the 1940s to the 1980s generated 53 million gallons of radioactive chemical waste, which is stored in 177 underground tanks at the Hanford site in southeastern Washington State. Recent attempts to begin the retrieval and treatment of these wastes require moving the waste to more modern tanks and result in potential exposure of the workers to unfamiliar odors emanating from headspace in the tanks. Given the unknown risks involved, workers were placed on supplied air respiratory protection. CH2MHILL, the managers of the Hanford site tank farms, asked an Independent Toxicology Panel (ITP) to assist them in issues relating to an industrial hygiene and risk assessment problem. The ITP was called upon to help determine the risk of exposure to vapors from the tanks, and in general develop a strategy for solution of the problem. This paper presents the methods used to determine the chemicals of potential concern (COPCs) and the resultant development of screening values and Acceptable Occupational Exposure Limits (AOELs) for these COPCs. A total of 1826 chemicals were inventoried and evaluated. Over 1500 chemicals were identified in the waste tanks headspaces and more than 600 of these were assigned screening values; 72 of these compounds were recommended for AOEL development. Included in this list of 72 were 57 COPCs identified by the ITP and of these 47 were subsequently assigned AOELs. An exhaustive exposure assessment strategy was developed by the CH2MHILL industrial hygiene department to evaluate these COPCs.

New Record of Moose (Alces alces) in Southeastern Washington State

Historical records of moose (Alces alces) in Washington are limited to the northeastern corner of the state. There are no paleozoological records of moose in Washington. Since the beginning of the third millennium, moose have been occasionally reported in southeastern Washington. A sub-adult bull moose was photographed in southeastern Washington in July 2009, about 80 km west of the nearest historically documented occurrence of moose. The observed individual and other recent sightings in southeastern Washington are likely the result of an increasing population of Idaho moose and their expansion into western areas of that state and eastern Washington.

Separation, characterization and initial reaction studies of magnetite particles from Hanford sediments

Magnetic and density separation methods have been applied to composite sediment samples from the Hanford formation from sediment recovered during drilling of an uncontaminated borehole located near the 200 West Area of the Hanford Site in southeastern Washington State. This paper describes the results of using those separation methods and from the characterization and initial reactivity measurements on a highly magnetic fraction isolated from that sediment. X-ray diffraction (XRD) analysis of the highly magnetic sediment fraction indicates that this material contains predominantly magnetite (Fe 3O 4). Particle morphology observed by scanning electron microscopy (SEM) and compositions determined energy dispersive spectroscopy (EDS) are consistent with this identification. Analyses by X-ray photoelectron spectroscopy (XPS) indicates that there is a thin coating on the particles that are likely a type of aluminosilicate. This highly magnetic fraction of material is not reactive with indigo carmine, an organic redox probe molecule that was shown to readily react with synthetic magnetite. Because of the limited amounts of material readily available, initial tests have been conducted that demonstrate the ability to complete U(VI) sorption on individual particles (nominally ∼100 μm in size) of the isolated sediment and to remove and mount these individual particles for analysis of the concentration and chemical state of the sorbed U species using small area XPS.

A short history of waste management at the Hanford Site

The world’s first full-scale nuclear reactors and chemical reprocessing plants built at the Hanford Site in the desert of southeastern Washington State produced two-thirds of the plutonium generated in the United States for nuclear weapons. Operating these facilities also created large volumes of radioactive and chemical waste, some of which was released into the environment exposing people who lived downwind and downstream. Hanford now contains the largest accumulation of nuclear waste in the Western Hemisphere. Hanford’s last reactor shut down in 1987 followed by closure of the last reprocessing plant in 1990. Today, Hanford’s only mission is cleanup. Most onsite radioactive waste and nuclear material lingers inside underground tanks or storage facilities. About half of the chemical waste remains in tanks while the rest persists in the soil, groundwater, and burial grounds. Six million dollars each day, or nearly two billion dollars each year, are spent on waste management and cleanup activities. There is significant uncertainty in how long cleanup will take, how much it will cost, and what risks will remain for future generations. This paper summarizes portions of the waste management history of the Hanford Site published in the book “Hanford: A Conversation about Nuclear Waste and Cleanup.” ( Gephart, 2003).

Assessment of Self-Efficacy for Cultural Competence in Prescribing

Caring for diverse populations requires knowledge and confidence about the influence of racial, ethnic, and cultural factors on the effectiveness of medication regimens. Despite advances in cultural competence education, disparities in health care continue to exist and often adversely affect minorities and the poor. The purpose of this study was to explore family nurse practitioners' (FNPs) perception of self-efficacy regarding their abilities to make culturally competent prescribing decisions. This descriptive, correlational study used a modified version of the 12-item “Self-Efficacy for Cultural Competence” Likert-type scale developed by Assemi, Cullander, and Hudmon. The survey results from 27 FNPs in southeastern Washington indicated moderate to high levels of self-efficacy in culturally competent prescribing. Results included a significant difference in mean total self-efficacy scores between male and female practitioners. Male practitioners demonstrated significantly higher total self-efficacy scores, and they also were more likely to work in clinics with a higher percentage of clients from different cultural backgrounds than their own. The Cronbach's alpha test for reliability was 0.92, indicating high internal consistency of this revised instrument. Strengths of the study include the response rate of 63% and the fact that this sample, although predominantly white women, mirrors national nurse practitioner demographics.

Utility of a Probabilistic Sampling Design to Determine Bull Trout Population Status Using Redd Counts in Basins of the Columbia River Plateau

AbstractRedd counts are commonly used to monitor the current population status, trends in abundance, and distribution of bull trout Salvelinus confluentus. In many cases redd counts are conducted at subjectively selected sites, and there has been limited evaluation of statistical sampling designs. We evaluated the utility of the generalized random tessellation stratified (GRTS) sampling design to determine bull trout population status through redd counts. We tested a sampling effort that would be economically practical to implement on a continuous basis in multiple drainages within the southeastern Washington and Oregon portions of the Columbia River plateau. We evaluated the logistics of a pilot application of the GRTS design, compared GRTS‐based estimates of redd abundance with those from census surveys, determined the precision of the GRTS estimates and the associated power for abundance comparisons, and compared the performance of the GRTS design with that of other probability sampling designs through simulation. A target of 50 sites per basin can be sampled by a two‐person survey crew multiple times over the spawning season. At that level of effort, the precision of redd abundance estimates ranges from 15% to 35%, depending on the patchiness of the redd distribution and the extent of the target population. These levels of precision are suitable for detecting a 30–70% change in redd abundance. Direct comparisons of GRTS‐based estimates with those obtained from a census showed mixed results. However, in a simulation study with three other probability sampling designs, GRTS consistently outperformed all but systematic sampling, which provided slightly better precision at intermediate sample sizes. Depending on the scale of inference, GRTS is useful in monitoring bull trout conservation units through redd counts, though a census may provide a more practical design for monitoring core areas as defined by the U.S. Fish and Wildlife Service.

Long-term biogenic soil mixing and transport in a hilly, loess-mantled landscape: Blue Mountains of southeastern Washington

In soil-mantled landscapes, downslope sediment transport occurs via disturbance-driven processes that vary with climate and vegetation change. To help constrain the long-term (≫ 10 yr) pattern and rate of soil mixing and transport in forests, we analyzed the distribution of tephra grains in soil along a hillslope transect in the Blue Mountains, SE Washington. Deposited within a loess mantle, tephra associated with Mt. Mazama (7.7 cal. kyr B.P.) serves as a marker bed for estimating erosion and transport rates. Moving downslope, the buried tephra horizon is progressively exhumed and becomes increasingly mixed in the upper soil layer, reflecting disturbance and transport via tree root growth and turnover. This pattern also implies increasing erosion rates downslope and our hillslope transect becomes increasingly convex coincident with progressive exhumation of the tephra layer. This systematic correspondence between topographic form, specifically, local convexity, and surface lowering is consistent with theoretical models for which soil transport rates depend on slope inclination. From our analysis, calibrated coefficients for a linear, slope-dependent transport model are on the order of 10 − 3 m 2 yr − 1 , consistent with previous work in forested loess-mantled landscapes. In addition, our results reveal both the high degree of soil mixing over millennial timescales and the local variability of mixing in forested landscapes. Furthermore, the results enable us to quantify the amount of energy expended by trees in mixing and transporting soil and the net sediment transport fraction of the net primary productivity NPP of the ecosystem.

Assessing fuel treatment effectiveness using satellite imagery and spatial statistics

Understanding the influences of forest management practices on wildfire severity is critical in fire-prone ecosystems of the western United States. Newly available geospatial data sets characterizing vegetation, fuels, topography, and burn severity offer new opportunities for studying fuel treatment effectiveness at regional to national scales. In this study, we used ordinary least-squares (OLS) regression and sequential autoregression (SAR) to analyze fuel treatment effects on burn severity for three recent wildfires: the Camp 32 fire in western Montana, the School fire in southeastern Washington, and the Warm fire in northern Arizona. Burn severity was measured using differenced normalized burn ratio (dNBR) maps developed by the Monitoring Trends in Burn Severity project. Geospatial data sets from the LANDFIRE project were used to control for prefire variability in canopy cover, fuels, and topography. Across all three fires, treatments that incorporated prescribed burning were more effective than thinning alone. Treatment effect sizes were lower, and standard errors were higher in the SAR models than in the OLS models. Spatial error terms in the SAR models indirectly controlled for confounding variables not captured in the LANDFIRE data, including spatiotemporal variability in fire weather and landscape-level effects of reduced fire severity outside the treated areas. This research demonstrates the feasibility of carrying out assessments of fuel treatment effectiveness using geospatial data sets and highlights the potential for using spatial autoregression to control for unmeasured confounding factors.

Temporal Stability of Genetic Variation within Natural Populations of Summer Steelhead Receiving Mitigation Hatchery Fish

AbstractStochastic fluctuation in allele frequencies may reflect microevolutionary processes responsible for genetic change, such as small effective population size (Ne), which is a legitimate concern for imperiled populations affected by environmental or anthropogenic factors. In salmonids, recent empirical studies have provided conflicting results regarding the consistency of within‐population genetic variation over time. In the present study, we surveyed the genetic variation at 14 microsatellite loci in two endemic populations of summer steelhead Oncorhynchus mykiss (Tucannon and Touchet) for seven consecutive years and the Lyons Ferry Hatchery stock (LFH) for 4 years. The LFH (mitigation) stock is used to enhance fishing opportunities in southeastern Washington State and not to aid in the recovery of natural populations. We observed statistically significant differences in allele frequencies between replicated collections from the same location. One of twenty‐one genic tests for the Tucannon River collections, 9 of 21 genic tests for the Touchet River collections, and all genic tests regarding LFH collections were statistically significant. Temporal variation was larger than spatial variation (0.86% and 0.44%, respectively). We also used genetic data to infer effective population sizes for natural steelhead populations and the LFH mitigation hatchery stock, with point estimates of 729.7, 599.4, and 266.7 for the Tucannon, Touchet, and LFH populations, respectively. Despite the temporal variation observed, relative genetic differentiation was stable over time, replicated collections tending to cluster together in factorial correspondence analyses of allele frequency data. However, the genetic data were consistent with the potential for gene flow between the Tucannon River and LFH populations. The potential benefits of stocking genetically differentiated hatchery fish to enhance fishing opportunities in the Tucannon River may be offset by the negative effects of hatchery introgression and the small Ne in hatchery fish.

Making Peace With Plutonium

A legacy of the Cold War plutonium production effort is thousands of square miles of contaminated land, among them the 586 square mile Hanford nuclear site in southeastern Washington. The Department of Energy (DOE) is responsible for cleanup and disposition of much of the property. Because of cost and technological limitations, some of the disposed land will remain hazardous for certain land uses. Ensuring the safe, post-disposition use is the long-term stewardship mission of the DOE. This article argues that the National Park Service should become the lead agency responsible for Hanford's B-Reactor, the world's first full-scale plutonium production reactor and now a National Historic Landmark. The author argues that the site should become the principal venue for continued civic discussions concerning cleanup - the <i>vita activa</i> of long-term stewardship.

Heterogeneous characteristics of streambed saturated hydraulic conductivity of the Touchet River, south eastern Washington, USA

AbstractTraditionally a streambed is treated as a layer of uniform thickness and low saturated hydraulic conductivity (K) in surface‐ and ground‐water studies. Recent findings have shown a high level of spatial heterogeneity within a streambed and such heterogeneity directly affects surface‐ and ground‐water exchange and can have ecological implications for biogeochemical transformations, nutrient cycling, organic matter decomposition, and reproduction of gravel spawning fish. In this study a detailed field investigation of K was conducted in two selected sites in Touchet River, a typical salmon spawning stream in arid south eastern Washington, USA. In‐stream slug tests were conducted to determine K following the Bouwer and Rice method. For the upper and lower sites, each 50 m long and 9 m wide and roughly 20 m apart, a sampling grid of 5 m longitudinally and 3 m transversely was used. The slug tests were performed for each horizontal coordinate at 0·3–0·45, 0·6–0·75, 0·9–1·05 and 1·2–1·35 m depth intervals unless a shallower impenetrable obstruction was encountered. Additionally, water levels were measured to obtain vertical hydraulic gradient (VHG) between each two adjacent depth intervals. Results indicated that K ranged over three orders of magnitude at both the upper and lower sites and differed between the two sites. At the upper site, K did not differ significantly among different depth intervals based on nonparametric statistical tests for mean, median, and empirical cumulative distribution, but the spatial pattern of K varied among different depth intervals. At the lower site, K for the 0·3–0·45 m depth interval differed statistically from those at other depth intervals, and no similar spatial pattern was found among different depth intervals. Zones of upward and downward water flow based on VHG also varied among different depth intervals, reflecting the complexities of the water flow regime. Detailed characterization of the streambed as attempted in this study should be helpful in providing information on spatial variations of streambed hydraulic properties as well as surface‐ and ground‐water interaction. Copyright © 2009 John Wiley &amp; Sons, Ltd.

Patterns in Resource Partitioning by Insect Biological Control Agents of Yellow Starthistle (Centaurea SolstitialisL.) in Washington

Abstract Entire yellow starthistle, Centaurea solstitialis L. (Asteraceae), plants were harvested from three southeastern Washington sites in September 2004 for seed head dissections to assess intra-plant patterns in the spatial distribution of the introduced false peacock fly, Chaetorellia succinea (Costa), and peacock fly, Chaetorellia australis Hering (Diptera: Tephritidae). Thirty plants were partitioned into three height classes and collected at each site, spanning the longitudinal range of yellow starthistle in Washington. Seed head canopies were stratified into three vertical sections and individual heads were dissected to determine bioagent occupation. Logistic regression analysis using a binary logit model was performed on data collected from each of the three sites separately due to varying site effects. Explanatory variables included plant height, plant width, plant canopy stratum (apical, mid, basal), and presence of other bioagents within a head. ‘Other bioagents’ detected include the yellow ...

Advective Desorption of Uranium(VI) from Contaminated Hanford Vadose Zone Sediments under Saturated and Unsaturated Conditions

Sedimentary, hydrologic, and geochemical variations in the Hanford subsurface environment, as well as compositional differences in contaminating waste streams, have created vast differences in the migration and mobility of U within the subsurface environment. A series of hydraulically saturated and unsaturated column experiments were performed to (i) assess the effect of water content on the advective desorption and migration of U from contaminated sediments and (ii) evaluate the U concentration that can develop in pore water and/or groundwater as a result of desorption/dissolution reactions. Flow rate and moisture content were varied to evaluate the influence of contact time, pore water velocity, and macropore desaturation on aqueous U concentrations. Sediments were collected from the T‐TX‐TY tank farm complex and the 300 Area Process Ponds located on the Hanford Site, southeastern Washington State. The sediments vary in depth, mineralogy, and in contamination events. Experiments were conducted under mildly alkaline/calcareous conditions representative of conditions commonly encountered at repository sites across the arid western United States and, in particular, the Hanford site. Results illustrate the release of U from these sediments is kinetically controlled, and low water contents encountered within the Hanford vadose zone result in the formation of mobile–immobile water regimes, which isolate a fraction of the reactive sites within the sediments, effectively reducing the concentration of U released into migrating pore waters.