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Addressing Data Heterogeneity: Lessons Learned From a Multimedia Risk Assessment

Description: Cleanup activities are currently being conducted by the US Department of Energy (DOE) at a former chemical plant site that has been inactive for more than 20 years. The Army produced nitroaromatic explosives at the 220-acre site during the 1940s, and radioactive materials of the uranium and thorium series were processed there by DOE`s predecessor agency during the 1950s and 1960s. Chemical and radioactive contaminants are present in soil, surface water, sediment, and groundwater at the site as a result of both past releases and disposal activities and subsequent contaminant migration. Samples have been collected from these media over a number of years under both DOE`s environmental monitoring program and the site characterization program of the Superfund process. Results of samples analyses have been compiled in a computerized data base. These data are being evaluated in the context of potential exposure pathways that are currently present at the site or that may be present in the future, in order to estimate possible adverse impacts to human health and the environment in the absence of cleanup. This paper discusses the methodology used to address associated tasks and the lessons learned during the assessment process. Statistical issues and recommended future directions for dealing with technical aspects of this project and with similar multimedia risk assessment projects are addressed in the final discussion. 10 refs., 9 figs., 1 tab.
Date: December 1, 1991
Creator: Öezkaynak, Halûk; Xue, Jianping; Butler, David A.; Haroun, Lynne A.; MacDonell, Margaret M. & Fingleton, Donald J.
Partner: UNT Libraries Government Documents Department

Oak Ridge Reservation, annual site environmental report for 1993

Description: The US DOE currently oversees activities on the Oak Ridge Reservation, a government-owned, contractor-operated facility. Three sites compose the reservation; Y-12, Oak Ridge National Laboratory, and K-25. This document contains a summary of environmental monitoring activities on the Oak Ridge Reservation (ORR) and its surroundings. The results summarized in this report are based on the data collected during calendar year (CY) 1993 and compiled in; Environmental Monitoring in the Oak Ridge Reservation: CY 1993 Results. Annual environmental monitoring on the ORR consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring is the collection and analysis of samples or measurements of liquid, gaseous, or airborne effluents for the purpose of characterizing and quantifying contaminants and process stream characteristics, assessing radiation and chemical exposures to members of the public, and demonstrating compliance with applicable standards. Environmental surveillance is the collection and analysis of samples of air, water, soil, foodstuffs, biota, and other media from DOE sites and their environs and the measurement of external radiation for purposes of demonstrating compliance with applicable standards, assessing radiation and chemical exposures to members of the public, and assessing effects, if any, on the local environment.
Date: November 1, 1994
Partner: UNT Libraries Government Documents Department

1993 Site environmental report Sandia National Laboratories, Albuquerque, New Mexico

Description: This 1993 report contains monitoring data from routine radiological and nonradiological environmental surveillance activities. Summaries of significant environmental compliance programs in progress, such as National Environmental Policy Act documentation, environmental permits, environmental restoration, and various waste management programs for Sandia National Laboratories in Albuquerque, New Mexico, are included. The maximum offsite dose impact was calculated to be 0.0016 millirem. The total population within a 50-mile (80 kilometer) radius of Sandia National Laboratories/New Mexico received an estimated collective dose of 0.027 person-rem during 1993 from the laboratories operations, As in the previous year, the 1993 operations at Sandia National Laboratories/New Mexico had no discernible impact on the general public or on the environment. This report is prepared for the U.S. Department of Energy in compliance with DOE Order 5400.1.
Date: November 1, 1994
Creator: Culp, T. A.; Cheng, C. F.; Cox, W.; Durand, N.; Irwin, M.; Jones, A. et al.
Partner: UNT Libraries Government Documents Department

Third annual environmental restoration monitoring and assessment report for FY 1994 of the Oak Ridge National Laboratory, Oak Ridge, Tennessee

Description: This report summarizes the salient features of the annual efforts of environmental monitoring, field investigations, and assessments conducted to support the Environmental Restoration (ER) Program at the Oak Ridge National Laboratory (ORNL). This report focuses on the watershed scale, providing an ORNL site-wide perspective on types, distribution, and transport of contamination. The results presented are used to enhance the conceptual understanding of the key contaminants and the sources, fluxes, and processes affecting their distribution and movement. This information forms a basis for prioritizing sites and for selecting, implementing, and evaluating remedial actions. This report summarizes the efforts of the Waste Area Grouping (WAG) 2 and Site Investigations (SI) Project. WAG 2 is the lower portion of the White Oak Creek system which drains the major contaminated sites at ORNL and discharges to the Clinch River where public access is allowed. The Remedial Investigation Plan (DOE 1992) for WAG 2 includes a long-term multimedia environmental monitoring effort that takes advantage of WAG 2`s role as an integrator and the major conduit of contaminants from the ORNL site. During FY 1992, the remedial investigation activities were integrated with a series of environmental monitoring and SI activities at ORNL that address pathways and processes important for contaminant movement to gain a more integrated perspective of contamination movement at the watershed scale.
Date: September 1, 1994
Creator: Clapp, R. B.; Watts, J. A. & Guth, M. A. S.
Partner: UNT Libraries Government Documents Department

Estimating exposure of terrestrial wildlife to contaminants

Description: This report describes generalized models for the estimation of contaminant exposure experienced by wildlife on the Oak Ridge Reservation. The primary exposure pathway considered is oral ingestion, e.g. the consumption of contaminated food, water, or soil. Exposure through dermal absorption and inhalation are special cases and are not considered hereIN. Because wildlife mobile and generally consume diverse diets and because environmental contamination is not spatial homogeneous, factors to account for variation in diet, movement, and contaminant distribution have been incorporated into the models. To facilitate the use and application of the models, life history parameters necessary to estimate exposure are summarized for 15 common wildlife species. Finally, to display the application of the models, exposure estimates were calculated for four species using data from a source operable unit on the Oak Ridge Reservation.
Date: September 1, 1994
Creator: Sample, B. E. & Suter, G. W. II
Partner: UNT Libraries Government Documents Department

Data management implementation plan for the site characterization of the Waste Area Grouping 1 Groundwater Operable Unit at Oak Ridge National Laboratory

Description: The Waste Area Grouping (WAG) 1 Groundwater Operable Unit (OU) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, is undergoing a site characterization. This project is not mandated by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA); therefore, no formalized meetings for data quality objective (DQO) development were held. Internally, DQOs were generated by the project team based on the end uses of the data to be collected. The 150-acre WAG 1 is contained within the ORNL security area. It includes all of the former ORNL radioisotope research, production, and maintenance facilities; former waste management areas; and some former administrative facilities. The goal of the WAG 1 Groundwater Site Characterization is to provide the necessary data on the nature and extent of groundwater contamination with an acceptable level of uncertainty to support the selection of remedial alternatives and to identify additional data needs for future actions. Primary objectives for the site characterization are: (1) To identify and characterize contaminant migration pathways based on the collection of groundwater data; (2) to identify sources of groundwater contamination and evaluate remedial actions which could be implemented to control or eliminate these sources; and (3) To conduct groundwater monitoring in support of other OUs in WAG 1 and the ORNL Groundwater OU.
Date: October 1, 1994
Creator: Ball, T. S. & Nickle, E. B.
Partner: UNT Libraries Government Documents Department

Study of combustion originated ash particles

Description: We are engaged in a study of the ash produced by combustion of lignite in a 750-MW power station. The aim is to follow the transport of elements with Z> 16 from the mine, through: (a) the combustion process, (b) emission to the atmosphere or (c) deposition in a land fill, (d) transport in the environment and (e) subsequent uptake by animals and humans. The resulting data will be used to estimate potential adverse impact on human health caused by operation of the power station.
Date: December 31, 1993
Creator: Toeroek, S.; Faigel, G.; Osan, J.; Toeroek, B.; Jones, K. W.; Rivers, M. L. et al.
Partner: UNT Libraries Government Documents Department

A comparison of dose and dose-rate conversion factors from the Soviet Union, United Kingdom, US Department of Energy, and the Idaho National Engineering Laboratory Fusion Safety Program

Description: Several independent data sets of radiological dose and dose-rate conversion factors (DCF/DRCF) have been tabulated or developed by the international community both for fission and fusion safety purposes. This report compares sets from the US Department of Energy, the Soviet Union, and the United Kingdom with those calculated by the Idaho National Engineering Laboratory Fusion Safety Program. The objectives were to identify trends and potential outlying values for specific radionuclides and contribute to a future benchmark evaluation of the CARR computer code. Fifty-year committed effective dose equivalent factors were compared for the inhalation and ingestion pathways. External effective dose equivalent rates were compared for the air immersion and ground surface exposure pathways. Comparisons were made by dividing dose factors in the different data bases by the values in the FSP data base. Differences in DCF/DRCF values less than a factor of 2 were considered to be in good agreement and are likely due to the use of slightly different decay data, variations in the number of organs considered for calculating CEDE, and rounding errors. DCF/DRCF values that differed by greater than a factor of 10 were considered to be significant. These differences are attributed primarily to the use of different radionuclide decay data, selection and nomenclature for different isomeric states, treatment of progeny radionuclides, differences in calculational methodology, and assumptions on a radionuclide`s chemical form.
Date: December 1, 1991
Creator: Rood, A. S. & Abbott, M. L.
Partner: UNT Libraries Government Documents Department

Radiological Assessment for the Dumping of Radioactive Wastes in the Oceans

Description: Over the last three decades or so, a number of international meetings have been convened to treat the specific problem of radioactive waste disposal into the oceans. The first of these meetings was held in 1958 at the United Nations Conference on the Law of the Sea. Immediately following, the International Atomic Energy Agency (IAEA), in the Brynielsson Report, recommended measures for ensuring that disposal of radioactive waste into the sea would not result in unacceptable hazards to man (IAEA 1961). Since that time, major changes have occurred in the philosophy and recommendations of the International Commission on Radiological Protection that are crucial to the assessments of impacts arising from this practice. Knowledge of oceanographic processes has improved markedly, providing better understanding of the physical transport process and of the pathways by which radionuclides are transported from marine dumping and disposal sites back to man. Finally, radioecology has developed to the stage where predictions of radionuclide cycling pathways and rates are possible. The IAEA report of 1961 was revised in 1983 (IAEA 1983). The IAEA has published many documents (Safety Series and Technical Documents) covering relevant areas such as oceanographic models, bioaccumulation factors, sediment distribution coefficients, and effects of ionizing radiation on organisms.
Date: June 1993
Creator: Templeton, W. L.
Partner: UNT Libraries Government Documents Department

Radionuclide concentrations in agricultural products near the Hanford Site, 1982 through 1992

Description: The Pacific Northwest Laboratory reviewed monitoring data for agricultural products collected from 1982 through 1992 near the Hanford Site to determine radionuclide concentration trends. While samples were collected and analyzed, and results reported annual in Hanford Site environmental reports, an 11-year data set was reviewed for this report to increase the ability to assess trends and potential Hanford effects. Products reviewed included milk, chicken, eggs, beef, vegetables, fruit, wine, wheat, and alfalfa. To determine which radionuclides were detected sufficiently often to permit analysis for trends and effects, each radionuclide concentration and its associated uncertainty were ratioed. Radionuclides were considered routinely detectable if more than 50% of the ratios were between zero and one. Data for these radionuclides were then analyzed statistically, using analyses of variance. The statistical analyses indicated the following: for the most part, there were no measurable effects for Hanford operations; radionuclide concentrations in all products reviewed remained relatively low when compared to concentrations that would result in a 1-mrem effective dose equivalent to an individual; radionuclide concentrations are decreasing in general; however, {sup 90}Sr concentrations in all media and {sup 129}I in milk increased from 1982 to 1986, then decreased gradually for the remainder of the review period. The {sup 129}I concentrations may be correlated with processing of irradiated reactor fuel at the Plutonium-Uranium Extraction (PUREX) Plant.
Date: June 1, 1994
Creator: Antonio, E. J.
Partner: UNT Libraries Government Documents Department

Environmental radiation monitoring plan for depleted uranium and beryllium areas, Yuma Proving Ground

Description: This Environmental Radiation Monitoring Plan (ERM) discusses sampling soils, vegetation, and biota for depleted uranium (DU) and beryllium (Be) at Yuma Proving Ground (YPG). The existing ERM plan was used and modified to more adequately assess the potential of DU and Be migration through the YPG ecosystem. The potential pathways for DU and Be migration are discussed and include soil to vegetation, soil to animals, vegetation to animals, animals to animals, and animals to man. Sample collection will show DU deposition and will be used to estimate DU migration. The number of samples from each area varies and depends on if the firing range of interest is currently used for DU testing (GP 17A) or if the range is not used currently for DU testing (GP 20). Twenty to thirty-five individual mammals or lizards will be sampled from each transect. Air samples and samples of dust in the air fall will be collected in three locations in the active ranges. Thirty to forty-five sediment samples will be collected from different locations in the arroys near the impact areas. DU and Be sampling in the Hard Impact and Soft Impact areas changed only slightly from the existing ERM. The modifications are changes in sample locations, addition of two sediment transport locations, addition of vegetation samples, mammal samples, and air sampling from three to five positions on the impact areas. Analysis of samples for DU or total U by inductively-coupled mass spectroscopy (ICP/MS), cc spectroscopy, neutron activation analysis (NAA), and kinetic phosphorimetric analysis (KPA) are discussed, and analysis for Be by ICP/MS are recommended. Acquiring total U (no isotope data) from a large number of samples and analysis of those samples with relatively high total U concentrations results in fewer isotopic identifications but more information on U distribution. From previous studies, total ...
Date: May 11, 1994
Creator: Ebinger, Michael H. & Hansen, Wayne R.
Partner: UNT Libraries Government Documents Department

Radiological impact of Par Pond drawdown from liquid effluent pathways

Description: The water level of Par Pond has been lowered over the past several months to reduce the effects in the event of catastrophic dam failure while assessing the condition of the dam and determining if repairs are necessary. In lowering the level of Par Pond, 60 billion liters of water containing low levels of tritium and cesium-137 were discharged to several onsite streams. SRS surface streams flow to the Savannah River. An assessment made to determine the total amount of tritium and Cs-137 discharged and to estimate the consequences to downstream Savannah River users. It is estimated that a total of 160 curies of tritium were displaced from Par Pond to the Savannah River between June 28, 1991 and September 19, 1991. This release could hypothetically result in a maximum individual dose of 3. 2{times}10{sup {minus}4} mrem and a total (80-km and drinking water populations) population dose of 1.4{times}10{sup {minus}2} person-rem. Likewise, a maximum individual dose of 5.0{times}10{sup {minus}2} mrem and a total population dose of 1.7{times}10{sup {minus}1} person- rem are predicted as a result of an estimated 0.21 curies of Cs-137 being discharged from Par Pond to the Savannah River.
Date: October 25, 1991
Creator: Carlton, W. H. & Hamby, D. M.
Partner: UNT Libraries Government Documents Department

An introductory guide to uncertainty analysis in environmental and health risk assessment. Environmental Restoration Program

Description: This report presents guidelines for evaluating uncertainty in mathematical equations and computer models applied to assess human health and environmental risk. Uncertainty analyses involve the propagation of uncertainty in model parameters and model structure to obtain confidence statements for the estimate of risk and identify the model components of dominant importance. Uncertainty analyses are required when there is no a priori knowledge about uncertainty in the risk estimate and when there is a chance that the failure to assess uncertainty may affect the selection of wrong options for risk reduction. Uncertainty analyses are effective when they are conducted in an iterative mode. When the uncertainty in the risk estimate is intolerable for decision-making, additional data are acquired for the dominant model components that contribute most to uncertainty. This process is repeated until the level of residual uncertainty can be tolerated. A analytical and numerical methods for error propagation are presented along with methods for identifying the most important contributors to uncertainty. Monte Carlo simulation with either Simple Random Sampling (SRS) or Latin Hypercube Sampling (LHS) is proposed as the most robust method for propagating uncertainty through either simple or complex models. A distinction is made between simulating a stochastically varying assessment endpoint (i.e., the distribution of individual risks in an exposed population) and quantifying uncertainty due to lack of knowledge about a fixed but unknown quantity (e.g., a specific individual, the maximally exposed individual, or the mean, median, or 95%-tile of the distribution of exposed individuals). Emphasis is placed on the need for subjective judgement to quantify uncertainty when relevant data are absent or incomplete.
Date: December 1, 1994
Creator: Hammonds, J. S.; Hoffman, F. O. & Bartell, S. M.
Partner: UNT Libraries Government Documents Department

Fall 1994 wildlife and vegetation survey, Norton Air Force Base, California

Description: The fall 1994 wildlife and vegetation surveys were completed October 3-7, 1994, at Norton Air Force Base (AFB), California. Two biologists from CDM Federal Programs, the U.S. Environmental Protection Agency (EPA) regional biologist and the Oak Ridge National Laboratory (ORNL) lead biologist conducted the surveys. A habitat assessment of three Installation Restoration Project (IRP) sites at Norton Air Force Base was also completed during the fall survey period. The IRP sites include: Landfill No. 2 (Site 2); the Industrial Wastewater Treatment Plant (IWTP) area; and Former Fire Training Area No. 1 (Site 5). The assessments were designed to qualitatively characterize the sites of concern, identify potential ecological receptors, and provide information for Remedial Design/Remedial Action activities. A Reference Area (Santa Ana River Wash) and the base urban areas were also characterized. The reference area assessment was performed to provide a baseline for comparison with the IRP site habitats. The fall 1994 survey is the second of up to four surveys that may be completed. In order to develop a complete understanding of all plant and animal species using the base, these surveys were planned to be conducted over four seasons. Species composition can vary widely during the course of a year in Southern California, and therefore, seasonal surveys will provide the most complete and reliable data to address changes in habitat structure and wildlife use of the site. Subsequent surveys will focus on seasonal wildlife observations and a spring vegetation survey.
Date: December 15, 1994
Partner: UNT Libraries Government Documents Department

Radiation doses from Hanford site releases to the atmosphere

Description: Radiation doses to individuals were estimated for the years 1944-1992. The dose estimates were based on the radioactive-releases from the Hanford Site in south central Washington. Conceptual models and computer codes were used to reconstruct doses through the early 1970s. The published Hanford Site annual environmental data were used to complete the does history through 1992. The most significant exposure pathway was found to be the consumption of cow`s milk containing iodine-131. For the atmospheric pathway, median cumulative dose estimates to the thyroid of children ranged from < 0.1 to 235 rad throughout the area studied. The geographic distribution of the dose levels was directly related to the pattern of iodine-131 deposition and was affected by the distribution of commercial milk and leafy vegetables. For the atmospheric pathway, the-highest estimated cumulative-effective-dose-equivalent (EDE) to an adult was estimated to be 1 rem at Ringold, Washington for the period 1944-1992. For the Columbia River pathway, cumulative EDE estimates ranged from <0.5 to l.5 rem cumulative dose to maximally exposed adults downriver from the Hanford Site for the years 1944-1992. The most significant river exposure pathway was consumption of resident fish containing phosphorus-32 and zinc-65.
Date: June 1, 1994
Creator: Farris, W. T.; Napier, B. A. & Ikenberry, T. A.
Partner: UNT Libraries Government Documents Department

Reconstruction of radionuclide concentrations in the Columbia River from Hanford, Washington to Portland, Oregon, January 1950--January 1971. Hanford Environmental Dose Reconstruction Project

Description: As part of the Hanford Environmental Dose Reconstruction (HEDR) Project, this report addresses the radioactivity in the Columbia River. The Columbia River received cooling-water effluent from the eight Hanford single-pass reactors and was the major pathway for waterborne radionuclides. The pathway began at the Hanford Site and continued downstream past the mouth of the Columbia River to the adjacent coastal and ocean areas. The objective of the HEDR Project`s Surface-Water Transport Task is to provide monthly average radionuclide concentrations in river water at specific locations along the Columbia River. These concentrations will be used in final estimates of radiation doses that individuals may have received from the Columbia River pathway. Under this task, a river hydraulic computer model was used to simulate transport of specific radionuclides from the Hanford reactors to Portland, Oregon. The model output consisted of monthly average water concentrations of radionuclides computed for 12 locations over 253 months (January 1950--January 1971). These water concentrations were forwarded to the staff of the Environmental Pathways and Dose Estimates Task for calculating dose estimates. The model used a source term input data file developed by the staff of the Source Terms Task which provided monthly average releases from each of the eight reactors, from January 1950 through January 1971. The Environmental Monitoring Task staff provided historical river monitoring data for use in validating computed water concentrations. The purpose of this report is to document the mathematical modeling required to reconstruct concentrations of radionuclides in Columbia River water. Modeling was required because available monitoring data are limited. The specific radionuclides considered are sodium-24, phosphorus-32, zinc-65, arsenic-76, and neptunium-239, determined by their relative contribution to dose for the river pathway (Napier 1993).
Date: January 1, 1994
Creator: Walters, W. H.; Gilmore, B. G. & Richmond, M. C.
Partner: UNT Libraries Government Documents Department

Columbia River Pathway Dosimetry Report, 1944-1992. Hanford Environmental Dose Reconstruction Project

Description: The purpose of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that individuals could have received as a result of radionuclide emissions since 1944 from the Hanford Site. One objective of the HEDR Project is to estimate doses to individuals who were exposed to the radionuclides released to the Columbia River (the river pathway). This report documents the last in a series of dose calculations conducted on the Columbia River pathway. The report summarizes the technical approach used to estimate radiation doses to three classes of representative individuals who may have used the Columbia River as a source of drinking water, food, or for recreational or occupational purposes. In addition, the report briefly explains the approaches used to estimate the radioactivity released to the river, the development of the parameters used to model the uptake and movement of radioactive materials in aquatic systems such as the Columbia River, and the method of calculating the Columbia River`s transport of radioactive materials. Potential Columbia River doses have been determined for representative individuals since the initiation of site activities in 1944. For this report, dose calculations were performed using conceptual models and computer codes developed for the purpose of estimating doses. All doses were estimated for representative individuals who share similar characteristics with segments of the general population.
Date: April 1, 1994
Creator: Farris, W. T.; Napier, B. A.; Simpson, J. C.; Snyder, S. F. & Shipler, D. B.
Partner: UNT Libraries Government Documents Department

HEDR modeling approach: Revision 1

Description: This report is a revision of the previous Hanford Environmental Dose Reconstruction (HEDR) Project modeling approach report. This revised report describes the methods used in performing scoping studies and estimating final radiation doses to real and representative individuals who lived in the vicinity of the Hanford Site. The scoping studies and dose estimates pertain to various environmental pathways during various periods of time. The original report discussed the concepts under consideration in 1991. The methods for estimating dose have been refined as understanding of existing data, the scope of pathways, and the magnitudes of dose estimates were evaluated through scoping studies.
Date: May 1, 1994
Creator: Shipler, D. B. & Napier, B. A.
Partner: UNT Libraries Government Documents Department

A review of plutonium environmental data with a bibliography for use in risk assessments

Description: Plutonium fueled radioisotopic heat sources find space, terrestrial, and undersea applications to generate electrical power. Such systems under postulated accident conditions could release radioactivity into the environment resulting in risks to the general population in the form of radiological doses and associated health effects. The evaluation of the radiological impact of postulated scenarios involving releases of activity into the environment includes identification of postulated accident release modes, including the probability of release and the release location; source term definition, including the activity of each radionuclide released and the corresponding chemical form and particle size distribution; analysis of the environmental behavior of the released radioactivity to determine the concentrations in environmental media (air, soil, and water) as a function of time; and analysis of the interaction between the environmental concentrations and man, leading to ingestion, inhalation, and external doses through each environmental exposure pathway. 443 refs., 2 figs., 4 tabs.
Date: June 15, 1983
Creator: Bartram, B.W. & Wilkinson, M.J.
Partner: UNT Libraries Government Documents Department

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Lakeview, Oregon. Revision 2

Description: The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, contaminated soil, equipment, and materials associated with the former uranium ore processing at UMTRA Project sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to minimize further contamination of ground water. Surface cleanup at the UMTRA Project site near Lakeview, Oregon, was completed in 1989. The mill operated from February 1958 to November 1960. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Ecological risks to plants or animals may result from exposure to surface water and sediment that have received contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will determine whether any action is needed to protect human health or the ecological environment.
Date: March 1, 1996
Partner: UNT Libraries Government Documents Department

Technical support for recovery phase decision-making in the event of a chemical warfare agent release

Description: In late 1985, Congress mandated that the U.S. stockpile of lethal unitary chemical agents and munitions be destroyed by the Department of the Army in a manner that provides maximum protection to the environment, the general public and personnel involved in the disposal program (Public Law 99-1, Section 1412, Title 14, Part b). These unitary munitions were last manufactured in the late 1960`s. The stockpiled inventory is estimated to approximate 25,000-30,000 tons, an includes organophosphate ({open_quotes}nerves{close_quotes}) agents such as VX [O-ethylester of S-(diisopropyl aminoethyl) methyl phosphonothiolate, C{sub 11}H{sub 26}NO{sub 2}PS] and vesicant ({open_quotes}blister{close_quotes}) agents such as Hd [sulfur mustard; bis (2-chloroethyl sulfide), C{sub 4}H{sub 8}Cl{sub 2}S]. The method of agent destruction selected by the Department of the Army is combined high-temperature and high-residence time incineration at secured military installations where munitions are currently stockpiled. This program supports the research program to address: the biomonitoring of nerve agent exposure; agent detection limits in foods and milk; and permeation of agents through porous construction materials.
Date: December 1995
Creator: Watson, A.; Kistner, S. & Halbrook, R.
Partner: UNT Libraries Government Documents Department

Corrective Action Decision Document for Corrective Action Unit 417: Central Nevada Test Area Surface, Nevada Appendix D - Corrective Action Investigation Report, Central Nevada Test Area, CAU 417

Description: This Corrective Action Decision Document (CADD) identifies and rationalizes the U.S. Department of Energy, Nevada Operations Office's selection of a recommended corrective action alternative (CAA) appropriate to facilitate the closure of Corrective Action Unit (CAU) 417: Central Nevada Test Area Surface, Nevada, under the Federal Facility Agreement and Consent Order. Located in Hot Creek Valley in Nye County, Nevada, and consisting of three separate land withdrawal areas (UC-1, UC-3, and UC-4), CAU 417 is comprised of 34 corrective action sites (CASs) including 2 underground storage tanks, 5 septic systems, 8 shaker pad/cuttings disposal areas, 1 decontamination facility pit, 1 burn area, 1 scrap/trash dump, 1 outlier area, 8 housekeeping sites, and 16 mud pits. Four field events were conducted between September 1996 and June 1998 to complete a corrective action investigation indicating that the only contaminant of concern was total petroleum hydrocarbon (TPH) which was found in 18 of the CASs. A total of 1,028 samples were analyzed. During this investigation, a statistical approach was used to determine which depth intervals or layers inside individual mud pits and shaker pad areas were above the State action levels for the TPH. Other related field sampling activities (i.e., expedited site characterization methods, surface geophysical surveys, direct-push geophysical surveys, direct-push soil sampling, and rotosonic drilling located septic leachfields) were conducted in this four-phase investigation; however, no further contaminants of concern (COCs) were identified. During and after the investigation activities, several of the sites which had surface debris but no COCs were cleaned up as housekeeping sites, two septic tanks were closed in place, and two underground storage tanks were removed. The focus of this CADD was to identify CAAs which would promote the prevention or mitigation of human exposure to surface and subsurface soils with contaminant concentrations above preliminary action levels. Based on ...
Date: April 2, 1999
Creator: United States. Department of Energy.
Partner: UNT Libraries Government Documents Department

Multimedia Environmental Pollutant Assessment System (MEPAS{reg_sign}): Exposure pathway and human health impact assessment models

Description: The Multimedia Environmental Pollutant Assessment System (MEPAS) provides physics-based models for human health risk assessment for radioactive and hazardous pollutants. MEPAS analyzes pollutant behavior in various media (air, soil, groundwater and surface water) and estimates transport through and between media and exposure and impacts to the environment, to the maximum individual, and to populations. MEPAS includes 25 exposure pathway models, a database with information on more than 650 contaminants, and a sensitivity module that allows for uncertainty analysis. Four major transport pathways are considered in MEPAS: groundwater, overland, surface water, and atmospheric. This report describes the exposure pathway and health impact assessment component of MEPAS, which provides an estimate of health impacts to selected individuals and populations from exposure to pollutants. The exposure pathway analysis starts with pollutant concentration in a transport medium and estimates the average daily dose to exposed individuals from contact with the transport medium or a secondary medium contaminated by the transport medium. The average daily dose is then used to estimate a measure of health impact appropriate to the type of pollutant considered. Discussions of the exposure pathway models include the assumptions and equations used to convert the transport medium concentrations to exposure medium concentrations. The discussion for a given exposure pathway defines the transport pathways leading to the exposure, the special processes considered in determining the pollutant concentration in the exposure medium, and the exposure model used to estimate the average daily dose. Models for the exposure pathway and health impact assessments require definition of several parameters. A summary of the notation used for these parameters is provided.
Date: May 1995
Creator: Strenge, D. L. & Chamberlain, P. J.
Partner: UNT Libraries Government Documents Department

Corrective Action Decision Document for Corrective Action Unit 417: Central Nevada Test Area Surface, Nevada

Description: This Corrective Action Decision Document (CADD) identifies and rationalizes the U.S. Department of Energy, Nevada Operations Office's selection of a recommended corrective action alternative (CAA) appropriate to facilitate the closure of Corrective Action Unit (CAU) 417: Central Nevada Test Area Surface, Nevada, under the Federal Facility Agreement and Consent Order. Located in Hot Creek Valley in Nye County, Nevada, and consisting of three separate land withdrawal areas (UC-1, UC-3, and UC-4), CAU 417 is comprised of 34 corrective action sites (CASs) including 2 underground storage tanks, 5 septic systems, 8 shaker pad/cuttings disposal areas, 1 decontamination facility pit, 1 burn area, 1 scrap/trash dump, 1 outlier area, 8 housekeeping sites, and 16 mud pits. Four field events were conducted between September 1996 and June 1998 to complete a corrective action investigation indicating that the only contaminant of concern was total petroleum hydrocarbon (TPH) which was found in 18 of the CASs. A total of 1,028 samples were analyzed. During this investigation, a statistical approach was used to determine which depth intervals or layers inside individual mud pits and shaker pad areas were above the State action levels for the TPH. Other related field sampling activities (i.e., expedited site characterization methods, surface geophysical surveys, direct-push geophysical surveys, direct-push soil sampling, and rotosonic drilling located septic leachfields) were conducted in this four-phase investigation; however, no further contaminants of concern (COCs) were identified. During and after the investigation activities, several of the sites which had surface debris but no COCs were cleaned up as housekeeping sites, two septic tanks were closed in place, and two underground storage tanks were removed. The focus of this CADD was to identify CAAs which would promote the prevention or mitigation of human exposure to surface and subsurface soils with contaminant concentrations above preliminary action levels. Based on ...
Date: April 2, 1999
Creator: United States. Department of Energy. Nevada Operations Office.
Partner: UNT Libraries Government Documents Department