Spokane River Research Articles

Investigating the Allometric Relationship for Total Mercury in Male and Female Signal Crayfish (Pacifastacus leniusculus) from Three Regions in the Columbia River Basin, USA.

The objective of this study was to evaluate the relationship between clawless body mass (CBM) and total mercury concentration (THg) in male and female crayfish captured from three different sites in the Columbia River Basin: the Spokane River, Boise River and Hangman Creek. It was found that the allometric relationships for THg in male and female crayfish did not differ from one another at any of the three locations (Spokane River: ANCOVA, F1,49 = 0.001, p = 0.63; Hangman Creek: ANCOVA, F1,73 = 0.007, p = 0.93; Boise River: ANCOVA, F1,38 = 0.02, p = 0.88. Furthermore, the slopes of the CBM and THg regression lines were not significantly different from one site to the next (ANCOVA, F2,166 = 1.5 p = 0.24), despite considerable differences in mean mass-adjusted THg across locations (Spokane River: 26.8 ± 2.6; Hangman Creek: 75.2 ± 2.1; Boise River: 99.0 ± 2.9). For signal crayfish (Pacifastacus leniusculus) from the Columbia River Basin, size and sex standardization can be accomplished with a single linear relationship.

The Spokane River ed. by Paul Lindholdt

Reviewed by: The Spokane River ed. by Paul Lindholdt Larry Cebula THE SPOKANE RIVER edited by Paul Lindholdt Washington University Press, Seattle, 2018. Illustrations, maps, bibliography, index. 296 pages. $24.95 paper. Who can tell the story of a river? Such a tale requires more than one voice. Geologists have their stories, as do Native peoples who live along its banks. Biologists see a river of interconnected life, while urban planners see a barrier to transportation and an urban amenity. Historians, environmentalists, and even lawyers have things to share. It is an interdisciplinary effort. It is to the credit of editor Paul Lindholdt that the anthology The Spokane River includes all of these voices and more. The twenty-eight chapters of the book include historical essays, policy reviews, poems, and personal experiences. The Spokane River begins as the outlet of Lake Couer D'Alene in Idaho. Over the course of its 111 miles, it rolls through the fertile Spokane Valley, plunges over a series of basalt cliffs in downtown Spokane, and snakes across ancient landscapes, gaining tributaries and volume until unites with the Columbia River beneath the waters of Lake Roosevelt. Its spectacular waterfalls are both the City of Spokane's most impressive sight and the reason for the town's existence. Yet, the river is not what it was. Dams turn long sections into slack-water lakes, some covered with algae blooms and dead fish in late summer. Houses crowd the banks in some places, and even where the river runs cool and clear, it carries heavy metals from long-ago mining operations and PCBs from paper plants. Signs warn anglers to limit their consumption of fish taken from the deceptively clear waters. Native voices in the book are strong. In the chapter titled "The River Gives Us Our Way of Life," Margo Hill of the Spokane Tribe recounts how her grandmother told her "the salmon hung from the horn of the saddle and stretched toward the ground" (p. 85). Her great grandmother Sadie Boyd made fish head soup, and when Hill would check to see what was cooking on her stove, she recounted: "Quite often I saw salmon eyes staring back at me" (p. 94). Fellow Spokane tribal member Barry Moses writes of the Spokane dialect of Interior Salish and how traditional names remind us of the Native uses and perceptions of the river. Lindholdt offers his own chapter, a biography of Lokout, brother of Qualchan and son of the Yakama chief Owhi. Born in the 1830s, Lokout's long life included stints as a linguist, a guide, a warrior, and finally a subject for photographer Edward Curtis in 1910. Other sections of the book focus on river history, efforts at environmental protection, The Expo '74 (Spokane's world's fair that reclaimed the banks of the river as a public park), personal essays, poems, and analyses of future threats to the Spokane River, including a loss of water and industrial contamination. The Spokane River is not only a superb book, it is a model for the kind of interdisciplinary collection that can be created around a common feature such as a river. The chapters are short, readable, and uniformly interesting. The book would work well in a college classroom. [End Page 216] Larry Cebula Eastern Washington University Washington State Archives Copyright © 2022 Oregon Historical Society

Effect of membrane filtration on the fate of polychlorinated biphenyls in wastewater treatment

The Spokane River is impacted by levels of polychlorinated biphenyls (PCBs) that have triggered fish consumption advisories and exceed water quality standards. Select wastewater treatment plants (WWTPs) on the river have been upgraded from secondary (biological) treatment to tertiary treatment in the form of membrane filtration to address phosphorus contamination. Because membrane filtration is effective at removing particles, it is likely to reduce PCB concentrations in the effluent as well. In this work, PCBs measured in the influents and effluent of several WWTPs discharging to the river were examined. Implementation of membrane filtration reduced PCB concentrations in the effluent (and therefore PCB loads to the river) by 33% at a facility that produces recycled and virgin paper and by ∼55% at municipal WWTPs, compared to secondary (activated sludge) treatment. Largest reductions in concentrations in effluent and loads were achieved for higher molecular weight (MW) PCB congeners (i.e. those with six or more chlorines), homologs, and formulations. The more modest reductions in effluent concentrations achieved at the paper WWTP may be due to the mix of PCBs in the wastewater there: it contained primarily the low MW Aroclor 1242 (presumably from carbonless copy paper) and PCB 11 (3,3′-dichlorobiphenyl) possibly from pigments. PCBs that appear to be associated with silicone products such as caulk, tubing, and o-rings are relatively more abundant in the effluent of some plants compared to the influent, suggesting that these congeners arise from contamination during sampling or from within the plant itself. At some WWTPs, this contamination accounts for nearly a third of PCBs measured in the effluent.

The Spokane River . Edited by Paul Lindholdt. Seattle: University of Washington Press, 2018. 283 pp. Illustrations, map, bibliography, and index. Cloth $90.00, paper $24.95.

The Spokane River . Edited by Paul Lindholdt. Seattle: University of Washington Press, 2018. 283 pp. Illustrations, map, bibliography, and index. Cloth $90.00, paper $24.95.

Sources of polychlorinated biphenyl blank contamination and their impact on fingerprinting

The development of high-resolution mass spectrometry methods for the measurement of polychlorinated biphenyls (PCBs) in environmental samples has dramatically reduced detection limits, leading to problems obtaining clean blanks. When PCBs are detected in samples at concentrations similar to the blanks, blank contamination must be addressed before fingerprinting and source apportionment through positive matrix factorization (PMF) can be successful. We tested a variety of blank correction methods using data from a study of water column concentrations of PCBs in the Spokane River, where concentrations of Σ209PCBs in whole water samples averaged 171 pg/L without blank correction and Σ209PCBs in the blanks averaged 88 pg/L. The results suggest that subtracting blank masses from sample masses can lead to erroneous results. Instead, censoring at one times the batch-specific blank level is a better approach. The sources of PCBs in field and method blanks were investigated by examining their congener profiles via PMF. The results suggest that commercial PCB formulations (in the US, Aroclors) continue to be the primary source of PCBs in blanks forty years after PCB production and use were banned in the United States. Other sources of PCBs to blanks include PCB 11 from pigments; PCBs 44 + 47 + 65, 45 + 51, and 68 arising from polymers cured using bis(2,4-dichlorobenzoyl) peroxide; and PCBs 1, 2, 3, 4, 8, 15 and others arising from silicone products derived from phenylsiloxanes, such as silicone-based adhesives.

The Spokane River. Edited by Paul Lindholdt

The Spokane River. Edited by Paul Lindholdt

How Well Does the Mechanistic Water Quality Model CE‐QUAL‐W2 Represent Biogeochemical Responses to Climatic and Hydrologic Forcing?

AbstractMechanistic water quality models are applied globally for water quality management in rivers and lakes. However, it is unclear how well these models represent the response of lakes to changes in climate and hydrologic conditions. To address this question, we conducted a series of climate and hydrologic sensitivity analyses using a parameterized water quality model, CE‐QUAL‐W2, for the Spokane River and Lake Spokane system. Two experimental tests with climate and flow forcing showed that the model predictions were rather insensitive to climatic‐driven hydrologic changes and a wide range of hydrologic conditions (1st to 99th percentile flows) for two different wastewater treatment plant discharge scenarios. The model realistically represented some aspects of Lake Spokane's observed responses to climatic and hydrologic variability, for example, the water residence time and some water quality trends. However, the model overestimated the reservoir total phosphorus (TPR) concentration by ~37% and the chlorophyll a (Chl a) concentration by ~31% and underestimated the minimum volume‐weighted hypolimnetic dissolved oxygen (DOMIN) concentration by ~26% for a wide range of flows compared to the observed data. In contrast to the model's water quality insensitivity, the modeled temperature was more sensitive to flow than was actually observed in Lake Spokane. This study provides guidance for improving the response of one of the most important mechanistic water quality models to climatic and hydrologic forcing and should help modelers and decision‐makers to develop a rigorous assessment of climate and flow sensitivity to improve the margin of safety when setting total maximum daily load targets.

Development of a system‐based water balance model to assess interrelated physical and anthropogenic constraints in lake and reservoir watersheds, applied to Coeur d'Alene Lake, Idaho, USA

AbstractThis study presents a methodology for the development of a water balance model that uses publicly available data in a manner useful to water scientists and managers who manage complex lake and reservoir watersheds. The approach was applied to Coeur d'Alene Lake, a naturally occurring lake that is controlled by a dam located on its outlet (Spokane River) in North Idaho, USA. As in many other areas, the region surrounding Coeur d'Alene Lake has experienced high rates of population growth in recent years, and there is concern that, as consumptive water use increases, the lake will eventually not be able to be managed to simultaneously maintain the federally mandated minimum flow requirements in the Spokane River and also maintain the target summertime elevation of 2128 feet (648.6 m) for recreation and hydropower purposes. The complexity caused by the competing uses at Coeur d'Alene Lake makes it an excellent case study for similarly characterized watersheds. Both a natural flow model and regulated elevation model were developed, and sensitivity analysis was conducted on both models to evaluate which lake processes have the greatest effects on lake elevation, thereby requiring the most attention. A ‘low‐flow’ scenario was modelled to demonstrate the usefulness of the model and to inform Coeur d'Alene Lake regional stakeholders regarding the interrelationship between current water policy and the lake's physical behaviour under stressed conditions that could result from climate change. Model result indicates that, while lake elevation may be maintained at the summertime elevation of 2128 feet (648.6 m) under a low‐flow scenario, the outflows in the Spokane River start to approach the minimum flow requirements in the month of August. The developed approach is useful where publicly available data exist and allows for economic, yet rigorous, water resources systems evaluation without requiring significant field data collection.

The modeled and observed response of Lake Spokane hypolimnetic dissolved oxygen concentrations to phosphorus inputs

ABSTRACTBrett MT, Ahopelto SK, Brown HK, Brynestad BE, Butcher TW, Coba EE, Curtis CA, Dara JT, Doeden KB, Evans KR, Fan L, Finley JD, Garguilo NJ, Gebreeyesus SM, Goodman MK, Gray KW, Grinnell C, Gross KL, Hite BRE, Jones AJ, Kenyon PT, Klock AM, Koshy RE, Lawler AM, Lu M, Martinkosky L, Miller-Schulze JR, Nguyen QTN, Runde ER, Stultz JM, Wang S, White FP, Wilson CH, Wong AS, Wu SY, Wurden PG, Young TR, Arhonditsis GB. 2016. The modeled and observed response of Lake Spokane hypolimnetic dissolved oxygen concentrations to phosphorus inputs. Lake Reserv Manage. 32:246–258.Lake Spokane, a reservoir in eastern Washington State, was previously hypereutrophic due to phosphorus discharges from the City of Spokane wastewater treatment plant (WWTP). This reservoir subsequently recovered to a meso-oligotrophic state after implementation of advanced phosphorus removal. The present study tested whether the mechanistic Lake Spokane water quality (WQ) model realistically represents the sensitivity of this reservoir's hypolimnetic oxygen concentrations to phosphorus inputs. We compared the observed relationship between the mean summer input total phosphorus concentration (TPIN) and the minimum volume weighted hypolimnetic dissolved oxygen concentration (DOMIN) to model values for conditions ranging from hypereutrophic to oligotrophic. Prior to advanced phosphorus removal, TPIN and DOMIN averaged 86 ± 37 (SD) µg/L and 1.4 ± 1.3 mg/L, respectively. Currently (2010–2014), these values average 14 ± 3 µg/L and 6.5 ± 0.8 mg/L, respectively. By contrast, the model's DOMIN response for similar TPIN concentrations was much less pronounced, with hypereutrophic and contemporary DOMIN averaging 3.8 ± 0.4 and 4.7 ± 0.04 mg/L, respectively. The model also has a structural DO deficit (saturated DO − DOMIN) of 5.3 mg/L that was evident when all TP inputs to the reservoir were set to zero. Similarly, when all WWTP effluent sources were set to TPEFF = 0 µg/L, the reservoir epilimnetic TP concentrations were ≈8 µg/L higher than the Spokane River inputs. The water quality model indicates that even if effluent phosphorus concentrations are reduced to zero, the dissolved oxygen goals for Lake Spokane cannot be met.

Cottus schitsuumsh, a new species of sculpin (Scorpaeniformes: Cottidae)in the Columbia River basin, Idaho-Montana, USA.

Fishes of the genus Cottus have long been taxonomically challenging because of morphological similarities among species and their tendency to hybridize, and a number of undescribed species may remain in this genus. We used a combination of genetic and morphological methods to delineate and describe Cottus schitsuumsh, Cedar Sculpin, a new species, from the upper Columbia River basin, Idaho-Montana, USA. Although historically confused with the Shorthead Sculpin (C. confusus), the genetic distance between C. schitsuumsh and C. confusus (4.84-6.29%) suggests these species are distant relatives. Moreover, the two species can be differentiated on the basis of lateral-line pores on the caudal peduncle, head width, and interpelvic width. Cottus schitsuumsh is also distinct from all other Cottus in this region in having a single small, skin-covered, preopercular spine. Haplotypes of mtDNA cytochrome oxidase c subunit 1 of C. schitsuumsh differed from all other members of the genus at three positions, had interspecific genetic distances typical for congeneric fishes (1.61-2.74% to nearest neighbors), and were monophyletic in maximum-likelihood trees. Microsatellite analyses confirmed these taxonomic groupings for species potentially sympatric with C. schitsuumsh and that fish used in morphological comparisons were unlikely to be introgressed. Its irregular distribution, in the Spokane River basin in Idaho and portions of the Clark Fork River basin in Montana, may have resulted from human-assisted translocation.

Nonlegacy PCBs: Pigment Manufacturing By-Products Get a Second Look

Polychlorinated biphenyls (PCBs) were commercially manufactured in the United States from about 1930 until 1979, when their production was banned under the Toxic Substances Control Act (TSCA) because of concerns about their extreme environmental persistence, ability to bioaccumulate, and adverse human health effects. PCBs were used in numerous industrial and consumer applications, most notably as insulation fluids in electrical transformers and generators but also in products including fluorescent lamp ballasts, caulk, and carbonless copy paper. These now-discontinued manufactured chemicals have received a great deal of attention in terms of research and environmental remediation. But other, lesser-known PCBs continue to be generated and released into the environment, not from intentionally created commercial products but as unintentional by-products of manufacturing processes including, according to recent studies, those used to make certain pigments used in dyes, inks, and paints. PCBs do not occur naturally, and once in the environment they can last for decades. Until recently, PCBs that were being detected in the environment were thought to come entirely from “legacy” sources. Yet developments in analytical technology have given researchers a better understanding of PCB sources, of the patterns of individual PCBs (or congeners) that are being detected environmentally, and the fate of PCBs in the environment—how they move between soil, sediment, water, and air. These advances have also enabled the detection of individual congeners at very low levels and the identification of many new and ongoing sources of PCBs beyond those resulting from historical commercial mixtures. Unintentionally produced PCBs were known to be present in inks and dyes when the U.S. Environmental Protection Agency (EPA) announced the final rule barring commercial PCB production in 1979. A rule allowing exemptions for PCBs in controlled manufacturing processes and as unintentional contaminants was promulgated under TSCA a few years later. This rule allowed for PCB concentrations of up to 50 ppm in certain products as a result of manufacturing processes.1 Recently, manufacturing by-product PCBs have been identified in wastewater, sediments, and air in numerous locations. They have also been positively identified in testing of new products colored with such pigments, so it is clear these PCBs are not occurring as a result of legacy commercial mixtures. What is emerging is an increasingly complex picture of the prevalence of nonlegacy PCBs alongside the persisting environmental presence of legacy PCBs, and a concurrent and likewise complex picture of how PCBs can affect human health at very low levels of exposure.

Impacts of Climate Change on Hydrology and Water Resources in the Boise and Spokane River Basins1

Jin, Xin and Venkataramana Sridhar, 2012. Impacts of Climate Change on Hydrology and Water Resources in the Boise and Spokane River Basins. Journal of the American Water Resources Association (JAWRA) 48(2): 197‐220. DOI: 10.1111/j.1752‐1688.2011.00605.xAbstract: In the Pacific Northwest, warming climate has resulted in a lengthened growing season, declining snowpack, and earlier timing of spring runoff. This study characterizes the impact of climate change in two basins in Idaho, the Spokane River and the Boise River basins. We simulated the basin‐scale hydrology by coupling the downscaled precipitation and temperature outputs from a suite of global climate models and the Soil and Water Assessment Tool (SWAT), between 2010 and 2060 and assess the impacts of climate change on water resources in the region. For the Boise River basin, changes in precipitation ranged from −3.8 to 36%. Changes in temperature were expected to be between 0.02 and 3.9°C. In the Spokane River region, changes in precipitation were expected to be between −6.7 and 17.9%. Changes in temperature appeared between 0.1 and 3.5°C over a period of the next five decades between 2010 and 2060. Without bias‐correcting the simulated streamflow, in the Boise River basin, change in peak flows (March through June) was projected to range from −58 to +106 m3/s and, for the Spokane River basin, the range was expected to be from −198 to +88 m3/s. Both the basins exhibited substantial variability in precipitation, evapotranspiration, and recharge estimates, and this knowledge of possible hydrologic impacts at the watershed scale can help the stakeholders with possible options in their decision‐making process.

Lake Missoula and Its Floods

The city of Spokane lies astride the Spokane River, some 40 miles from its origination near Coeur d’Alene, Idaho. The convention center and hotel, site of the 65th annual meeting of SRM, are located right along the river, creating a beautiful and even idyllic setting. These qualities make it even harder to imagine a long-ago day when a miles-wide wall of water, measuring as much as 500 feet high, bore down on this site. Hours before, a great ice dam on glacial Lake Missoula (present-day Clark Fork River) had failed. The dam was as much as 2,500 feet in height, impounded a lake up to 2,000 feet deep, extended east in the intermontane valleys for 200 miles, and covered some 3,000 square miles. It probably contained over 500 cubic miles of water, approximating half the volume of Lake Michigan. It is now generally agreed that catastrophic fl oods, in accordance with prevailing ice age conditions, repeatedly issued from Lake Missoula, probably on the order of several tens of times. Geologists estimate that the latest and last of the fl oods occurred about 13,000 years ago, creating the observable effects on the ground today, while largely obscuring the effects of earlier fl oods. Most students of the fl oods support that this particular event and its effects should be named “Bretz’s Flood” after the early geologist J Harlen Bretz, who fi rst recognized in 1919 the effects of catastrophic fl ooding on the Columbia drainage of southeastern Washington, as well as the Columbia River Gorge, the Portland-Vancouver Basin, and the Willamette Valley of Oregon. Over the 2 million years of the last ice age, four major glaciations advanced into what is now the northwestern United States. The last of these, the Wisconsin glaciation, left clear evidence of its effects, while likely obscuring most of the evidence of earlier fl ooding. It is near-certain, however, that each of the many fl oods inundated thousands of square miles in what is now central and southeastern Washington to depths of hundreds of feet. Later study also showed that the many fl oods likely shared the same provenance, that is, the same cause and effect. Piecing together the available evidence, it appears that the full glacial climate was cold and dry, with strong winds that redistributed soil materials to the southeastern quadrant of the Columbia Basin. These processes created what is today called the Palouse, an area of wind-deposited silts (loess) over the underlying basalt that had literally oozed out of the earth over previous untold centuries. The winds created dune-like deposits of variable orientation and depth that today make up fertile farmland in southeastern Washington and adjacent Idaho. Bretz’s Flood followed the path of the many earlier fl oods and recreated the effects over thousands of square miles in the Columbia Basin. These can briefl y be considered in four major categories: 1) the channeled scablands, 2) the river canyon, 3) the Grand Coulee, and 4) Lake Lewis.

Spokane River Watershed Strategies for Point and Nonpoint Source Management to Meet the Most Restrictive TMDL in the Nation

Spokane River Watershed Strategies for Point and Nonpoint Source Management to Meet the Most Restrictive TMDL in the NationRecognizing the water quality management challenges presented by a sensitive receiving waterbody and the need for a comprehensive watershed approach, the Spokane County Division of Utilities is taking a leadership position in implementing advanced point source wastewater treatment technology and managing a Washington/Idaho bi-state nonpoint source phosphorus management program for the Spokane...Author(s)David L. ClarkMichael KaschBen BratteboSourceProceedings of the Water Environment FederationSubjectSession 12: Tools for ImplementationDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2011ISSN1938-6478SICI1938-6478(20110101)2011:2L.632;1-DOI10.2175/193864711802864930Volume / Issue2011 / 2Content sourceImpaired Waters SymposiumFirst / last page(s)632 - 640Copyright2011Word count195Subject keywordsPhosphorus removalTotal Maximum Daily LoadNonpoint sourcesPoint sourcesSeptic systemsWater qualityLoading analysisWatershed management

Integrated nutrient removal design for very low phosphorus levels

The State of Washington has found that the Spokane River is DO impaired, and is requiring dischargers to reduce phosphorus inputs to the river. Spokane County elected to build a new water recovery facility with a target effluent total phosphorus level of 50 microg/L on a seasonal average basis. Spokane County elected to use a private company to design/build and operate their facility. The very low nutrient requirements, and lack of historical operating information, necessitated an integrated approach to the nutrient removal design while considering the risks and benefits of the various treatment options. The process selection evaluated membrane bioreactors and tertiary membranes for the primary liquids process in combination with chemical and/or biological phosphorus removal. The final process selection included chemically enhanced primary treatment, membrane bioreactor with metal salts, and dewatering liquor treatment with an innovative post aerobic digestion step.

Augmentation of seasonal low stream flows by artificial recharge in the Spokane Valley-Rathdrum Prairie aquifer of Idaho and Washington, USA

Conjunctive management of surface water and groundwater requires sophisticated spatial and temporal analysis. In situations involving multiple jurisdictions such as state boundaries, management problems are magnified due to often conflicting regulations and policies. A transient MODFLOW model of the Spokane Valley-Rathdrum Prairie (SVRP) aquifer/river system mutually accepted by both the states of Idaho and Washington, USA, was used to evaluate regional solutions to potential water shortages through the use of strategically placed infiltration basins or injection wells. Artificial recharge of the SVRP aquifer was simulated using diversions from Lake Pend Oreille during winter periods when flows are high and excess water is available. Alternative locations for potential wells and detention basins were examined. Lag times for the water to impact stream/groundwater interaction areas along the Spokane River were evaluated to assess the potential for augmenting stream flows from July through September. Results indicated that the aquifer could be used to improve low-flow season streamflow values utilizing both infiltration basins and injection wells with winter surface water diversions. Depending on the location, as much as 30% of the winter diversion rate could be lagged to improve summer flows at the Spokane gage. Thus, a regional mitigation strategy is scientifically feasible.

A two‐parameter climate elasticity of streamflow index to assess climate change effects on annual streamflow

This study extends the single parameter precipitation elasticity of streamflow index into a two parameter climate elasticity index, as a function of both precipitation and temperature, in order to assess climatic effects on annual streamflow. Application of the proposed index to two basins indicates that the single parameter precipitation elasticity index may give a general relationship between precipitation and streamflow in some cases, but that it cannot reflect the complicated non‐linear relationship among streamflow, precipitation and temperature. For example, for the Spokane River basin the climate elasticity of streamflow index varies from 2.4 to 0.2, for a precipitation increase of 20%, as temperature varies from 1°C lower to 1.8°C higher than the long term mean. Thus a 20% precipitation increase may result in a streamflow increase of 48% if the temperature is 1°C lower but only a 4% increase if the temperature is 1.8°C higher than the long‐term mean. The proposed method can be applied to other basins to assess potential climate change effects on annual streamflow. The results of the two case studies can inform planning of long‐term basin water management strategies taking into account global change scenarios.

Application of ultrasonic assisted extraction of chemically diverse organic compounds from soils and sediments

The objective of this research was the development, optimization, and demonstration of an ultrasonic assisted extraction (UAE) based method for organic anthropogenic waste indicators (AWIs) with a range of physicochemical properties from soil and sediment samples. The optimized method was designed to be cost effective compared to existing extraction methods, which may require large quantities of consumables, produce substantial volumes of organic waste, or require costly instrumentation or equipment. Reagent grade sand, soil collected from the native grassland in proximity to Eastern Washington University (EWU), and sediment samples collected from the Spokane river were used as sample matrices during method development. These matrices were fortified with eight AWIs of varying chemical properties that are representative of a variety of household, industrial, and agricultural sources. The recoveries of the AWIs spiked onto these matrices were determined in the extracts using gas chromatography/mass spectrometry (GC/MS). These values reflect the efficiency of the method for extraction of these analytes from representative environmental matrices. Recoveries ranged from 46.1% to 110% in the fortified soil and from 49.2% to 118.6% in the fortified sediment samples, which is comparable with existing methods for the study analytes. The optimized method was then used to quantify AWIs in a biosolid-amended soil. Indole and p-cresol were detected in the biosolid-amended soil.

Impacts of Climate Change on Regional Hydrological Regimes in the Spokane River Watershed

This study develops and implements a methodology to estimate the impacts of global climate change on regional hydrological regimes using ArcGIS Geostatistical Analyst. The model is easily used and can be expanded to different watersheds. The ArcGIS Geostatistical Analyst interface provides a comprehensive set of tools for creating surfaces from measured sample points compared with the previous method of using adjustable tension continuous curvature surface gridding. As a result, users can rapidly compare different interpolation techniques in order to obtain the best solution. Model results can subsequently be used in GIS models for visualization and analyses. The methodology was applied to the Spokane River Watershed. Results indicate that a 30% precipitation increase causes a 50% increase of streamflow when the temperature is normal compared to only a 20–30% increase in streamflow if the average annual air temperature is 1.5°C higher than normal. Conversely, a 20% precipitation decrease results in approx...

Free Zinc Ion and Dissolved Orthophosphate Effects on Phytoplankton from Coeur d'Alene Lake, Idaho

Coeur d'Alene Lake in northern Idaho is fed by two major rivers: the Coeur d'Alene River from the east and the St. Joe River from the south, with the Spokane River as its outlet to the north. This phosphorus-limited lake has been subjected to decades of mining (primarily for zinc and silver) and other anthropogenic inputs. A 32 full-factorial experimental design was used to examine the interactive effects of free (uncomplexed) zinc ion and dissolved-orthophosphate concentrations on phytoplankton that were isolated from two sites along a longitudinal zinc-concentration gradient in Coeur d'Alene Lake. The two sites displayed different dominanttaxa. Chlorella minutissima, a dominant species near the southern St. Joe River inlet, exhibited greater sensitivity to free Zn ions than Asterionella formosa, collected nearer the Coeur d'Alene River mouth with elevated dissolved-zinc concentrations. Empirical phytoplankton-response models were generated to describe phytoplankton growth in response to remediation strategies in the surrounding watershed. If dissolved Zn can be reduced in the water column from >500 nM (i.e., current concentrations near and down stream of the Coeur d'Alene River plume) to <3 nM (i.e., concentrations near the southern St. Joe River inlet) such that the lake is truly phosphorus limited, management of phosphorus inputs by surrounding communities will ultimately determine the limnologic state of the lake.