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Public Health Benefits of End-Use Electrical Energy Efficiency in California: An Exploratory Study

Description: This study assesses for California how increasing end-use electrical energy efficiency from installing residential insulation impacts exposures and disease burden from power-plant pollutant emissions. Installation of fiberglass attic insulation in the nearly 3 million electricity-heated homes throughout California is used as a case study. The pollutants nitrous oxides (NO{sub x}), sulfur dioxide (SO{sub 2}), fine particulate matter (PM2.5), benzo(a)pyrene, benzene, and naphthalene are selected for the assessment. Exposure is characterized separately for rural and urban environments using the CalTOX model, which is a key input to the US Environmental Protection Agency (EPA) Tool for the Reduction and Assessment of Chemicals and other environmental Impacts (TRACI). The output of CalTOX provides for urban and rural populations emissions-to-intake factors, which are expressed as an individual intake fraction (iFi). The typical iFi from power plant emissions are on the order of 10{sup -13} (g intake per g emitted) in urban and rural regions. The cumulative (rural and urban) product of emissions, population, and iFi is combined with toxic effects factors to determine human damage factors (HDFs). HDF are expressed as disability adjusted life years (DALYs) per kilogram pollutant emitted. The HDF approach is applied to the insulation case study. Upgrading existing residential insulation to US Department of Energy (DOE) recommended levels eliminates over the assmned 50-year lifetime of the insulation an estimated 1000 DALYs from power-plant emissions per million tonne (Mt) of insulation installed, mostly from the elimination of PM2.5 emissions. In comparison, the estimated burden from the manufacture of this insulation in DALYs per Mt is roughly four orders of magnitude lower than that avoided.
Date: June 1, 2006
Creator: McKone, Thomas E. & Lobscheid, A.B.
Partner: UNT Libraries Government Documents Department

The significance of the erosion-induced terrestrial carbonsink

Description: Estimating carbon (C) balance in erosional and depositionallandscapes is complicated by the effects of soil redistribution on bothnet primary productivity (NPP) and decomposition. Recent studies arecontradictory as to whether soil erosion does or does not constitute a Csink. Here we clarify the conceptual basis for how erosion can constitutea C sink. Specifically, the criterion for an erosional C sink is thatdynamic replacement of eroded C, and reduced decomposition rates indepositional sites, must together more than compensate for erosionallosses. This criterion is in fact met in many erosional settings, andthus erosion and deposition can make a net positive contribution to Csequestration. We show that, in a cultivated Mississippi watershed and acoastal California watershed, the magnitude of the erosion-induced C sinkis likely to be on the order of 1 percent of NPP and 16 percent of erodedC. Although soil erosion has serious environmental impacts, the annualerosion-induced C sink offsets up to 10 percent of the global fossil fuelemissions of carbon dioxide for 2005.
Date: October 10, 2006
Creator: Berhe, A.A.; Harte, J.; Harden, J.W. & Torn, M.S.
Partner: UNT Libraries Government Documents Department

Energy Efficiency in Western Utility Resource Plans: Impacts onRegional Resources Assessment and Support for WGA Policies

Description: In the aftermath of the consumer price shocks and short-term power shortages of the 2000-01 electricity crisis, policymakers and regulators in Western states are placing increased emphasis on integrated resource planning (IRP), resource adequacy and assessment and a diversified portfolio of resources to meet the needs of electricity consumers. In some states, this has led to a resurgence in state and utility commitments to energy efficiency. Increasing interest in acquiring energy efficiency as a power-system resource is also driven by the desire to dampen high growth rates in electricity demand in some Western states, rapid increases in natural gas prices, concerns about the environmental impacts of electricity generation (e.g. water consumption by power plants, air quality), and the potential of energy efficiency to provide utility bill savings for households and businesses (WGA CDEAC 2006). Recognizing the cost-competitiveness and environmental benefits of energy efficiency, the Western Governor's Association (WGA) has set a high priority for energy efficiency, establishing a goal of reducing projected electricity demand by 20% across the West by 2020 in a policy resolution on Clean and Diversified Energy for the West (WGA 2004). Nationally, the need for improved tracking of demand-side resources in load forecasting is formalized in the North American Electric Reliability Council (NERC)'s recently adopted reliability standards, which utilities and regional reliability organizations will need to comply with (NERC 2005a and 2005b). In this study, we examine the treatment of energy efficiency in recent resource plans issued by fourteen investor-owned utilities (IOUs) in the Western United States and Canada. The goals of this study are to: (1) summarize energy-efficiency resources as represented in a large sample of recent resource plans prepared by Western utilities and identify key issues; (2) evaluate the extent to which the information provided in current resource plans can be used to support ...
Date: August 1, 2006
Creator: Hopper, Nicole; Goldman, Charles & Schlegal, Jeff
Partner: UNT Libraries Government Documents Department

ENVIRONMENTAL ASSESSMENT FOR THE NPDES STORM WATER COMPLIANCE ALTERNATIVES AT THE SRS

Description: The U.S. Department of Energy (DOE) prepared this environmental assessment (EA) to evaluate the potential environmental impacts associated with proposed and alternative actions to achieve water quality permit compliance at 38 storm water outfalls located at the Savannah River Site (SRS) (Figure 1-1). Effluent monitoring data indicates that some of these outfalls may not presently comply with new National Pollutant Discharge Elimination System (NPDES) Storm Water General Permit effluent standards that became effective July 1, 2005 (SCR000000). The NPDES permit requires that best management practices (BMPs) be implemented and maintained, as necessary, to ensure that storm water discharges at SRS do not cause or contribute to the contravention of applicable state water quality standards (WQS).
Date: November 1, 2006
Creator: Shedrow, C
Partner: UNT Libraries Government Documents Department

Concentrations of Radionuclides and Trace Elements in Environmantal Media arond te Dual-Axis Radiographic Hydrodynamic Test Facilit at Los Alamos National Laboratory during 2005

Description: The Mitigation Action Plan (MAP) for the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory requires that samples of biotic and abiotic media be collected after operations began to determine if there are any human health or environmental impacts. The DARHT facility is the Laboratory's principal explosive test facility. To this end, samples of soil and sediment, vegetation, bees, and birds were collected around the facility in 2005 and analyzed for concentrations of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 234}U, {sup 235}U, {sup 238}U, Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Bird populations have also been monitored. Contaminant results, which represent up to six sample years since the start of operations, were compared with (1) baseline statistical reference levels (BSRLs) established over a four-year preoperational period before DARHT facility operations, (2) screening levels (SLs), and (3) regulatory standards. Most radionuclides and trace elements were below BSRLs and those few samples that contained radionuclides and trace elements above BSRLs were below SLs. Concentrations of radionuclides and nonradionuclides in biotic and abiotic media around the DARHT facility do not pose a significant human health hazard. The total number of birds captured and number of species represented were similar in 2003 and 2004, but both of these parameters increased substantially in 2005. Periodic interruption of the scope and schedule identified in the MAP generally should have no impact on meeting the intent of the MAP. The risk of not sampling one of the five media in any given year is that if a significant impact to contaminant levels were to occur there would exist a less complete understanding of the extent of the change to the baseline for these media and to the ecosystem as a ...
Date: May 15, 2006
Creator: Gonzales, G. J.; Fresquez, P.R.; C.D.Hathcock & Keller, D.C.
Partner: UNT Libraries Government Documents Department

Advanced Power Plant Development and Analyses Methodologies

Description: Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into advanced power plant systems with goals of achieving high efficiency and minimized environmental impact while using fossil fuels. These power plant concepts include ''Zero Emission'' power plants and the ''FutureGen'' H{sub 2} co-production facilities. The study is broken down into three phases. Phase 1 of this study consisted of utilizing advanced technologies that are expected to be available in the ''Vision 21'' time frame such as mega scale fuel cell based hybrids. Phase 2 includes current state-of-the-art technologies and those expected to be deployed in the nearer term such as advanced gas turbines and high temperature membranes for separating gas species and advanced gasifier concepts. Phase 3 includes identification of gas turbine based cycles and engine configurations suitable to coal-based gasification applications and the conceptualization of the balance of plant technology, heat integration, and the bottoming cycle for analysis in a future study. Also included in Phase 3 is the task of acquiring/providing turbo-machinery in order to gather turbo-charger performance data that may be used to verify simulation models as well as establishing system design constraints. The results of these various investigations will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support.
Date: February 6, 2006
Creator: Samuelsen, G.S. & Rao, A.D.
Partner: UNT Libraries Government Documents Department

Advanced Power Plant Development and Analysis Methodologies

Description: Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into advanced power plant systems with goals of achieving high efficiency and minimized environmental impact while using fossil fuels. These power plant concepts include 'Zero Emission' power plants and the 'FutureGen' H2 co-production facilities. The study is broken down into three phases. Phase 1 of this study consisted of utilizing advanced technologies that are expected to be available in the 'Vision 21' time frame such as mega scale fuel cell based hybrids. Phase 2 includes current state-of-the-art technologies and those expected to be deployed in the nearer term such as advanced gas turbines and high temperature membranes for separating gas species and advanced gasifier concepts. Phase 3 includes identification of gas turbine based cycles and engine configurations suitable to coal-based gasification applications and the conceptualization of the balance of plant technology, heat integration, and the bottoming cycle for analysis in a future study. Also included in Phase 3 is the task of acquiring/providing turbo-machinery in order to gather turbo-charger performance data that may be used to verify simulation models as well as establishing system design constraints. The results of these various investigations will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support.
Date: June 30, 2006
Creator: Rao, A.D.; Samuelsen, G.S.; Robson, F.L.; Washom, B. & Berenyi, S.G.
Partner: UNT Libraries Government Documents Department

Best Practices in Determining the Impacts of Municipal Programs on Energy Use, Air Quality, and Other Ancillary Costs and Benefits (Poster)

Description: This poster, submitted for the CU Energy Initiative/NREL Symposium on October 3, 2006 held in Boulder, Colorado, discusses best practices for determining the impacts of municipal programs on energy use, air quality, and other costs and benefits.
Date: October 3, 2006
Creator: Brown, E. & Mosey, G.
Partner: UNT Libraries Government Documents Department

Nevada Transportatoion Options Study

Description: This study performs a cost and schedule analysis of three Nevada Transportation options that support waste receipt at the repository. Based on the U.S. Department of Energy preference for rail transportation in Nevada (given in the Final Environmental Impact Statement), it has been assumed that a branch rail line would be constructed to support waste receipt at the repository. However, due to potential funding constraints, it is uncertain when rail will be available. The three Nevada Transportation options have been developed to meet a varying degree of requirements for transportation and to provide cost variations used in meeting the funding constraints given in the Technical Direction Letter guidelines for this study. The options include combinations of legal-weight truck, heavy-haul truck, and rail. Option 1 uses a branch rail line that would support initial waste receipt at the repository in 2010. Rail transportation would be the primary mode, supplemented by legal weight trucks. This option provides the highest level of confidence in cost and schedule, lowest public visibility, greatest public acceptability, lowest public dose, and is the recommended option for support of waste receipt. The completion of rail by 2010 will require spending approximately $800 million prior to 2010. Option 2 uses a phased rail approach to address a constrained funding scenario. To meet funding constraints, Option 2 uses a phased approach to delay high cost activities (final design and construction) until after initial waste receipt in 2010. By doing this, approximately 95 percent of the cost associated with completion of a branch rail line is deferred until after 2010. To support waste receipt until a branch rail line is constructed in Nevada, additional legal-weight truck shipments and heavy-haul truck shipments (on a limited basis for naval spent nuclear fuel) would be used to meet the same initial waste receipt rates ...
Date: May 25, 2006
Creator: GEHNER, P.; WEAVER, E.M. & FOSSUM, L.
Partner: UNT Libraries Government Documents Department

Energy penalty analysis of possible cooling water intake structurerequirements on existing coal-fired power plants.

Description: Section 316(b) of the Clean Water Act requires that cooling water intake structures must reflect the best technology available for minimizing adverse environmental impact. Many existing power plants in the United States utilize once-through cooling systems to condense steam. Once-through systems withdraw large volumes (often hundreds of millions of gallons per day) of water from surface water bodies. As the water is withdrawn, fish and other aquatic organisms can be trapped against the screens or other parts of the intake structure (impingement) or if small enough, can pass through the intake structure and be transported through the cooling system to the condenser (entrainment). Both of these processes can injure or kill the organisms. EPA adopted 316(b) regulations for new facilities (Phase I) on December 18, 2001. Under the final rule, most new facilities could be expected to install recirculating cooling systems, primarily wet cooling towers. The EPA Administrator signed proposed 316(b) regulations for existing facilities (Phase II) on February 28, 2002. The lead option in this proposal would allow most existing facilities to achieve compliance without requiring them to convert once-through cooling systems to recirculating systems. However, one of the alternate options being proposed would require recirculating cooling in selected plants. EPA is considering various options to determine best technology available. Among the options under consideration are wet-cooling towers and dry-cooling towers. Both types of towers are considered to be part of recirculating cooling systems, in which the cooling water is continuously recycled from the condenser, where it absorbs heat by cooling and condensing steam, to the tower, where it rejects heat to the atmosphere before returning to the condenser. Some water is lost to evaporation (wet tower only) and other water is removed from the recirculating system as a blow down stream to control the building up of suspended ...
Date: November 27, 2006
Creator: Veil, J. A.; Littleton, D. J.; Gross, R. W.; Smith, D. N.; Parsons, E.L., Jr.; Shelton, W. W. et al.
Partner: UNT Libraries Government Documents Department

International Collaboration on CO2 Sequestration

Description: This reporting period covers the first half of the two-year sub-task, which includes a review of recent and ongoing engineering studies concerning practical modes for the ocean discharge of CO{sub 2}, review of recent and ongoing experimental studies concerning the rates (and extent) of formation and dissolution for CO{sub 2} hydrates, review of recent and ongoing biological studies concerning organism response to reduced pH and increased CO{sub 2} concentration, and the definition of discharge scenarios. These steps have been successfully completed. Results-to-date were presented at the Annual Fall Meeting of AGU (December 2005) and will be presented at the Annual DOE Meeting on Carbon Capture and Sequestration (May, 2006). The objective during this reporting period was to begin a two-year sub-task to update an assessment of environmental impacts from direct ocean sequestration. The approach is based on the work of Auerbach et al. (1997) and Caulfield et al. (1997) to assess acute impacts, but uses updated information concerning injection scenarios and bioassays.
Date: May 19, 2006
Creator: Herzog, Howard J. & Adams, E. Eric
Partner: UNT Libraries Government Documents Department

Inventory Data Package for Hanford Assessments

Description: This document presents the basis for a compilation of inventory for radioactive contaminants of interest by year for all potentially impactive waste sites on the Hanford Site for which inventory data exist in records or could be reasonably estimated. This document also includes discussions of the historical, current, and reasonably foreseeable (1944 to 2070) future radioactive waste and waste sites; the inventories of radionuclides that may have a potential for environmental impacts; a description of the method(s) for estimating inventories where records are inadequate; a description of the screening method(s) used to select those sites and contaminants that might make a substantial contribution to impacts; a listing of the remedial actions and their completion dates for waste sites; and tables showing the best estimate inventories available for Hanford assessments.
Date: June 1, 2006
Creator: Kincaid, Charles T.; Eslinger, Paul W.; Aaberg, Rosanne L.; Miley, Terri B.; Nelson, Iral C.; Strenge, Dennis L. et al.
Partner: UNT Libraries Government Documents Department

Installation of 200 kW UTC PC-25 Natural Gas Fuel Cell At City of Anaheim Police Station

Description: The City of Anaheim Public Utilities Department (Anaheim) has been providing electric service to Anaheim residents and businesses for over a century. As a city in a high-growth region, identifying sources of reliable energy to meet demand is a constant requirement. Additionally, as more power generation is needed, locating generating stations locally is a difficult proposition and must consider environmental and community impacts. Anaheim believes benefits can be achieved by implementing new distributed generation technologies to supplement central plants, helping keep pace with growing demand for power. If the power is clean, then it can be delivered with minimal environmental impact. Anaheim started investigating fuel cell technology in 2000 and decided a field demonstration of a fuel cell power plant would help determine how the technology can best serve Anaheim. As a result, Anaheim completed the project under this grant as a way to gain installation and operating experience about fuel cells and fuel cell capabilities. Anaheim also hopes to help others learn more about fuel cells by providing information about this project to the public. Currently, Anaheim has hosted a number of requested tours at the project site, and information about the project can be found on Anaheim Public Utilities RD&D Project website. The Anaheim project was completed in four phases including: research and investigation, purchase, design, and construction. The initial investigative phase started in 2000 and the construction of the project was completed in February 2005. Since acceptance and startup of the fuel cell, the system has operated continuously at an availability of 98.4%. The unit provides an average of about 4,725 kilowatthours a day to the Utilities' generation resources. Anaheim is tracking the operation of the fuel cell system over the five-year life expectancy of the fuel stack and will use the information to determine how fuel ...
Date: September 15, 2006
Creator: Predisik, Dina
Partner: UNT Libraries Government Documents Department

Bird Movements and Behaviors in the Gulf Coast Region: Relation to Potential Wind-Energy Developments

Description: The purpose of this paper is to discuss the possible impacts of wind development to birds along the lower Gulf Coast, including both proposed near-shore and offshore developments. The report summarizes wind resources in Texas, discusses timing and magnitude of bird migration as it relates to wind development, reviews research that has been conducted throughout the world on near- and offshore developments, and provides recommendations for research that will help guide wind development that minimizes negative impacts to birds and other wildlife resources.
Date: June 1, 2006
Creator: Morrison, M. L.
Partner: UNT Libraries Government Documents Department

Preliminary Assessment of Potential Impacts to Dungeness Crabs from Disposal of Dredged Materials from the Columbia River

Description: Dredging of the Columbia River navigation channel has raised concerns about dredging-related impacts on Dungeness crabs (Cancer magister). The overall objectives of this effort are to synthesize what is known about disposal effects on Dungeness crabs (Phase 1) and to offer approaches to quantify the effects, including approaches to gain a population-level perspective on any effects found in subsequent studies (Phase 2). This report documents Phase 1, which included (1) development of a conceptual model to integrate knowledge about crab biology and the physical processes occurring during disposal, (2) application of physics-based numerical modeling of the disposal event to understand the physical forces and processes to which a crab might be exposed during disposal, (3) conduct of a vulnerability analysis to identify the potential mechanisms by which crabs may be injured, and (4) recommendations of topics and approaches for future studies to assess the potential population-level effects of disposal on Dungeness crabs. The conceptual model first recognizes that disposal of dredged materials is a physically dynamic process with three aspects: (1) convective descent and bottom encounter, (2) dynamic collapse and spreading, and (3) mounding. Numerical modeling was used to assess the magnitude of the potentially relevant forces and extent of mounding in single disposal events. The modeling outcomes show that predicted impact pressure, shear stress, and mound depth are greatly reduced by discharge in deep water, and somewhat reduced at longer discharge duration. The analysis of numerical modeling results and vulnerabilities indicate that the vulnerability of crabs to compression forces under any of the disposal scenarios is low. For the deep-water disposal scenarios, the maximum forces and mounding do not appear to be sufficiently high enough to warrant concern for surge currents or burial at the depths involved (over 230 ft). For the shallow-water (45 to 65 ft), short-duration disposal ...
Date: February 1, 2006
Creator: Pearson, Walter H.; Miller, Martin C.; Williams, Greg D.; Kohn, Nancy P. & Skalski, John R.
Partner: UNT Libraries Government Documents Department

Spray Rolling Aluminum Strip

Description: Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.
Date: May 10, 2006
Creator: Lavernia, E.J.; Delplanque, J-P & McHugh, K.M.
Partner: UNT Libraries Government Documents Department

Controls on Gas Hydrate Formation and Dissociation

Description: The main objectives of the project were to monitor, characterize, and quantify in situ the rates of formation and dissociation of methane hydrates at and near the seafloor in the northern Gulf of Mexico, with a focus on the Bush Hill seafloor hydrate mound; to record the linkages between physical and chemical parameters of the deposits over the course of one year, by emphasizing the response of the hydrate mound to temperature and chemical perturbations; and to document the seafloor and water column environmental impacts of hydrate formation and dissociation. For these, monitoring the dynamics of gas hydrate formation and dissociation was required. The objectives were achieved by an integrated field and laboratory scientific study, particularly by monitoring in situ formation and dissociation of the outcropping gas hydrate mound and of the associated gas-rich sediments. In addition to monitoring with the MOSQUITOs, fluid flow rates and temperature, continuously sampling in situ pore fluids for the chemistry, and imaging the hydrate mound, pore fluids from cores, peepers and gas hydrate samples from the mound were as well sampled and analyzed for chemical and isotopic compositions. In order to determine the impact of gas hydrate dissociation and/or methane venting across the seafloor on the ocean and atmosphere, the overlying seawater was sampled and thoroughly analyzed chemically and for methane C isotope ratios. At Bush hill the pore fluid chemistry varies significantly over short distances as well as within some of the specific sites monitored for 440 days, and gas venting is primarily focused. The pore fluid chemistry in the tub-warm and mussel shell fields clearly documented active gas hydrate and authigenic carbonate formation during the monitoring period. The advecting fluid is depleted in sulfate, Ca Mg, and Sr and is rich in methane; at the main vent sites the fluid is methane ...
Date: March 3, 2006
Creator: Kastner, Miriam & MacDonald, Ian
Partner: UNT Libraries Government Documents Department

Hydraulic Characteristics of the Lower Snake River During Periods of Juvenile Fall Chinook Migration

Description: This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10°C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir’s epilimnion at the Clearwater/Snake River confluence is of key biological importance to juvenile fall Chinook salmon. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four lower Snake reservoirs are also heavily influenced by wind forcing at the water’s surface, and during periods of low river discharge, often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The depth of this upper warm layer and its direction of travel ...
Date: January 30, 2006
Creator: Cook, Chris B.; Dibrani, Berhon; Richmond, Marshall C.; Bleich, Matthew D.; Titzler, P. Scott & Fu, Tao
Partner: UNT Libraries Government Documents Department

Factors Influencing The Accuracy Of A Macroinvertebrate Bioassessment Protocol In South Carolina Coastal Plain Streams (DRAFT)

Description: The Multiple Habitat Sampling Protocol (MHSP) is a bioassessment method designed to assess the ecological health of South Carolina streams on the basis of macroinvertebrate samples collected from natural substrates. The MHSP is computed by averaging the EPT (number of Ephemeroptera, Plecoptera, Trichoptera taxa) and BI (a biotic index that reflects the pollution tolerances of individual taxa) to produce a bioclassification score. The MHSP produced low bioclassification scores that could falsely indicate environmental degradation in some undisturbed, high quality streams in the Sandhills ecoregion. This problem had two causes: (1) the metrics (especially EPT) were significantly related to stream size, which confounded stream size effects with environmental impacts, and (2) the scoring criteria for EPT were too high for some Sandhills streams, likely because of unrecognized heterogeneity among the Sandhills streams from which the criteria were derived. We corrected these problems by developing new scoring criteria from ecologically comparable undisturbed streams and by utilizing residuals from regressions of the metrics on stream width to normalize for stream size. The MHSP and related protocols are effective methods for assessing environmental quality but allowances must be made for the effects of stream size and the potential ecological heterogeneity that naturally exists among streams in some ecoregions.
Date: January 31, 2006
Creator: Paller, M. H.; Martin, F. D.; Wike, L. D. & Specht, W. L.
Partner: UNT Libraries Government Documents Department

Final monitoring plan for site restoration at Murdock, Nebraska.

Description: In early 2005, Argonne National Laboratory conducted an Engineering Evaluation/Cost Analysis (EE/CA; Argonne 2005b) to address carbon tetrachloride contamination identified in groundwater and surface water at Murdock, Nebraska, approximately 22 mi east-northeast of Lincoln (Figure 1.1). The EE/CA study was performed for the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA), as the technical basis for a proposed removal action for the Murdock site. The EE/CA was conducted in compliance with an Administrative Order on Consent issued for Murdock by the U.S. Environmental Protection Agency (EPA 1991). Three removal action alternatives were examined through the use of site-specific data and predictive simulations of groundwater flow and contaminant transport performed with calibrated numerical models. The alternatives were evaluated individually and compared against performance criteria established under the National Oil and Hazardous Substances Pollution Contingency Plan and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). On the basis of these evaluations, an alternative employing phytoremediation in conjunction with seasonal groundwater extraction and treatment by spray irrigation was recommended by the CCC/USDA to permanently reduce the carbon tetrachloride contaminant levels in groundwater and surface water at the site. The proposed alternative is being implemented in cooperation with the EPA. Under the direction of the CCC/USDA and the EPA, implementation of the chosen removal action occurred in phases, beginning in April 2005. Installation of all the required remediation systems was completed by the end of August 2005. Specific technical objectives of the removal action are as follows: (1) To eliminate pathways for potential human exposure to carbon tetrachloride concentrations above the regulatory limit of 44.2 {micro}g/L in surface water at the site. (2) To minimize or eliminate any detrimental environmental impacts of carbon tetrachloride discharge to the surface waters of a tributary creek located immediately north of the town. (3) To ...
Date: February 28, 2006
Creator: LaFreniere, L. M.
Partner: UNT Libraries Government Documents Department