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Air Pathway Analysis for Cleanup at the Chemical Plant Area of the Weldon Spring Site

Description: The Weldon Spring site is a mixed waste site located in St. Charles County, Missouri. Cleanup of the site is in the planning and design stage, and various engineering activities were considered for remedial action, including excavating soils, dredging sludge, treating various contaminated media in temporary facilities, transporting and staging supplies and contaminated material, and placing waste in an engineered disposal cell. Both contaminated and uncontaminated emissions from these activities were evaluated to assess air quality impacts and potential health effects for workers and the general public during the cleanup period. A site-specific air quality modeling approach was developed to address several complex issues, such as a variety of emission sources, an array of source/receptor configurations, and complicated sequencing/scheduling. This approach can be readily adapted to reflect changes in the expected activities as engineering plans are finalized.
Date: January 1, 1994
Creator: Chang, Y. S.
Partner: UNT Libraries Government Documents Department

Modeling emissions and dispersion of contaminants from cleanup activities at a mixed waste site to estimate air impacts and risks

Description: The transport and dispersion of contaminants via the air pathway is a major concern during cleanup of contaminated sites. Impacts to air quality and human health during cleanup were evaluated for the Weldon Spring site by using site-specific information for source areas, activities, and receptor locations. In order to ensure protection of human health and the environment, results are being used to focus on those cleanup activities for which release controls should be emphasized.
Date: September 1, 1993
Creator: Chang, Y. S. & Menlove, S.
Partner: UNT Libraries Government Documents Department

Estimation of environmental noise impacts within architectural spaces.

Description: Public Law 91-596, ''Occupational Safety and Health Act of 1970,'' Dec. 29, 1970, stimulated interest in modeling the impacts of interior noise on employees, as well as the intelligibility of interior public-address and other speech intra-communication systems. The classical literature on this topic has primarily featured a statistical uniform diffuse-field model. This was pioneered by Leo L. Beranek in the 1950s, based on energy-density formulations at the former Bell Telephone (AT and T) Laboratories in the years from 1930 to 1950. This paper compares the classical prediction approach to the most recent statistical methods. Such models were developed in the late 1970s and included innovations such as consideration of irregularly shaped (e.g., L-shaped) interior room spaces and coupled spaces.
Date: May 3, 2002
Creator: Chang, Y. S.; Liebich, R. E. & Chun, K. C.
Partner: UNT Libraries Government Documents Department

Development of computer program ENMASK for prediction of residual environmental masking-noise spectra, from any three independent environmental parameters

Description: Residual environmental sound can mask intrusive4 (unwanted) sound. It is a factor that can affect noise impacts and must be considered both in noise-impact studies and in noise-mitigation designs. Models for quantitative prediction of sensation level (audibility) and psychological effects of intrusive noise require an input with 1/3 octave-band spectral resolution of environmental masking noise. However, the majority of published residual environmental masking-noise data are given with either octave-band frequency resolution or only single A-weighted decibel values. A model has been developed that enables estimation of 1/3 octave-band residual environmental masking-noise spectra and relates certain environmental parameters to A-weighted sound level. This model provides a correlation among three environmental conditions: measured residual A-weighted sound-pressure level, proximity to a major roadway, and population density. Cited field-study data were used to compute the most probable 1/3 octave-band sound-pressure spectrum corresponding to any selected one of these three inputs. In turn, such spectra can be used as an input to models for prediction of noise impacts. This paper discusses specific algorithms included in the newly developed computer program ENMASK. In addition, the relative audibility of the environmental masking-noise spectra at different A-weighted sound levels is discussed, which is determined by using the methodology of program ENAUDIBL.
Date: March 31, 2000
Creator: Chang, Y.-S.; Liebich, R. E. & Chun, K. C.
Partner: UNT Libraries Government Documents Department

Development of computer program ENAUDIBL for computation of the sensation levels of multiple, complex, intrusive sounds in the presence of residual environmental masking noise

Description: The relative audibility of multiple sounds occurs in separate, independent channels (frequency bands) termed critical bands or equivalent rectangular (filter-response) bandwidths (ERBs) of frequency. The true nature of human hearing is a function of a complex combination of subjective factors, both auditory and nonauditory. Assessment of the probability of individual annoyance, community-complaint reaction levels, speech intelligibility, and the most cost-effective mitigation actions requires sensation-level data; these data are one of the most important auditory factors. However, sensation levels cannot be calculated by using single-number, A-weighted sound level values. This paper describes specific steps to compute sensation levels. A unique, newly developed procedure is used, which simplifies and improves the accuracy of such computations by the use of maximum sensation levels that occur, for each intrusive-sound spectrum, within each ERB. The newly developed program ENAUDIBL makes use of ERB sensation-level values generated with some computational subroutines developed for the formerly documented program SPECTRAN.
Date: March 31, 2000
Creator: Liebich, R. E.; Chang, Y.-S. & Chun, K. C.
Partner: UNT Libraries Government Documents Department

Impacts of Western Area Power Administration`s power marketing alternatives on air quality and noise

Description: The Western Area Power Administration, which is responsible for marketing electricity produced at the hydroelectric power-generating facilities operated by the Bureau of Reclamation on the Upper Colorado River, has proposed changes in the levels of its commitment (sales) of long-term firm capacity and energy to its customers. This report describes (1) the existing conditions of air resources (climate and meteorology, ambient air quality, and acoustic environment) of the region potentially affected by the proposed action and (2) the methodology used and the results of analyses conducted to assess the potential impacts on air resources of the proposed action and the commitment-level alternatives. Analyses were performed for the potential impacts of both commitment-level alternatives and supply options, which include combinations of electric power purchases and different operational scenarios of the hydroelectric power-generating facilities.
Date: May 1, 1995
Creator: Chun, K.C.; Chang, Y.S. & Rabchuk, J.A.
Partner: UNT Libraries Government Documents Department

Probabilistic consequence model of accidenal or intentional chemical releases.

Description: In this work, general methodologies for evaluating the impacts of large-scale toxic chemical releases are proposed. The potential numbers of injuries and fatalities, the numbers of hospital beds, and the geographical areas rendered unusable during and some time after the occurrence and passage of a toxic plume are estimated on a probabilistic basis. To arrive at these estimates, historical accidental release data, maximum stored volumes, and meteorological data were used as inputs into the SLAB accidental chemical release model. Toxic gas footprints from the model were overlaid onto detailed population and hospital distribution data for a given region to estimate potential impacts. Output results are in the form of a generic statistical distribution of injuries and fatalities associated with specific toxic chemicals and regions of the United States. In addition, indoor hazards were estimated, so the model can provide contingency plans for either shelter-in-place or evacuation when an accident occurs. The stochastic distributions of injuries and fatalities are being used in a U.S. Department of Homeland Security-sponsored decision support system as source terms for a Monte Carlo simulation that evaluates potential measures for mitigating terrorist threats. This information can also be used to support the formulation of evacuation plans and to estimate damage and cleanup costs.
Date: June 2, 2008
Creator: Chang, Y.-S.; Samsa, M. E.; Folga, S. M. & Hartmann, H. M.
Partner: UNT Libraries Government Documents Department

Assessment of health benefits from controlling air pollution in Shanghai, China.

Description: The large urban centers of the industrializing countries of the world are experiencing severe air quality problems as their demands for energy increase faster than their ability to afford strong environmental protection. This situation is particularly true in the fast-growing part of Asia, where coal often provides the fuel for power generation and industrial development and where the transportation sector grows unchecked. This paper describes the development of an integrated assessment of urban air quality and mitigation options for the city of Shanghai, China. First, a sector-specific, gridded inventory of emissions of SO{sub 2}, NO{sub x}, and particulate matter (PM) is developed. PM is divided into three size categories (TSP, PM{sub 10}, and PM{sub 2.5}) and split into carbonaceous and mineral classes. The URBAT model, a non-steady-state Lagrangian puff model, and related techniques are used to determine the spatial distribution of ambient concentrations of primary and secondary pollutant species. Damage functions are developed to determine the effects of these levels on human health in the greater Shanghai area. Two control scenarios are developed (for power generation and industry), and their effects on emissions of each species are estimated. The health benefits of the control measures are determined, and their relative costs are calculated. The result is a rudimentary cost-benefit analysis that can be used by urban and environmental planners as a guide for determining the relative effectiveness of taking different courses of action.
Date: June 18, 2002
Creator: Chang, Y.-S.; Streets, D. G.; Tsao, C. L.; Li, J.; Guttikunda, S. & Carmichael, G. R.
Partner: UNT Libraries Government Documents Department

Evaluation of the area factor used in the RESRAD code for the estimation of airborne contaminant concentrations of finite area sources

Description: The area factor is used in the RESRAD code to estimate the airborne contaminant concentrations for a finite area of contaminated soils. The area factor model used in RESRAD version 5.70 and earlier (referred to as the old area factor) was a simple, but conservative, mixing model that tended to overestimate the airborne concentrations of radionuclide contaminants. An improved and more realistic model for the area factor (referred to here as the new area factor) is described in this report. The new area factor model is designed to reflect site-specific soil characteristics and meteorological conditions. The site-specific parameters considered include the size of the source area, average particle diameter, and average wind speed. Other site-specific parameters (particle density, atmospheric stability, raindrop diameter, and annual precipitation rate) were assumed to be constant. The model uses the Gaussian plume model combined with contaminant removal processes, such as dry and wet deposition of particulates. Area factors estimated with the new model are compared with old area factors that were based on the simple mixing model. In addition, sensitivity analyses are conducted for parameters assumed to be constant. The new area factor model has been incorporated into RESRAD version 5.75 and later.
Date: July 1, 1998
Creator: Chang, Y. S.; Yu, C. & Wang, S. K.
Partner: UNT Libraries Government Documents Department

Risk assessment for the transportation of hazardous waste and hazardous waste components of low-level mixed waste and transuranic waste for the US Department of Energy waste management programmatic environmental impact statement

Description: This report, a supplement to Appendix E (Transportation Risk) of the U.S. Department of Energy Waste Management Programmatic Environmental Impact Statement (WM PEIS), provides additional information supporting the accident data for chemical risk assessment and health risk methodology described in that appendix (Part II) and presents the uncertainty analysis and on-site risk calculations. This report focuses on hazardous material truck accident rates, release probabilities, and release quantities; provides the toxicological values derived for each hazardous chemical assessed in the WM PEIS and further details on the derivation of health criteria; describes the method used in the transportation risk assessments to address potential additivity of health effects from simultaneous exposure to several chemicals and the method used to address transportation risks for maximally exposed individuals; presents an expanded discussion of the uncertainty associated with transportation risk calculations; and includes the results of the on-site transportation risk analysis. In addition, two addenda are provided to detail the risk assessments conducted for the hazardous components of low-level mixed waste (Addendum I) and transuranic waste (Addendum II).
Date: December 1, 1996
Creator: Lazaro, M.A.; Policastro, A.J.; Hartmann, H.M. & Chang, Y.S.
Partner: UNT Libraries Government Documents Department

Fisk-based criteria to support validation of detection methods for drinking water and air.

Description: This report was prepared to support the validation of analytical methods for threat contaminants under the U.S. Environmental Protection Agency (EPA) National Homeland Security Research Center (NHSRC) program. It is designed to serve as a resource for certain applications of benchmark and fate information for homeland security threat contaminants. The report identifies risk-based criteria from existing health benchmarks for drinking water and air for potential use as validation targets. The focus is on benchmarks for chronic public exposures. The priority sources are standard EPA concentration limits for drinking water and air, along with oral and inhalation toxicity values. Many contaminants identified as homeland security threats to drinking water or air would convert to other chemicals within minutes to hours of being released. For this reason, a fate analysis has been performed to identify potential transformation products and removal half-lives in air and water so appropriate forms can be targeted for detection over time. The risk-based criteria presented in this report to frame method validation are expected to be lower than actual operational targets based on realistic exposures following a release. Note that many target criteria provided in this report are taken from available benchmarks without assessing the underlying toxicological details. That is, although the relevance of the chemical form and analogues are evaluated, the toxicological interpretations and extrapolations conducted by the authoring organizations are not. It is also important to emphasize that such targets in the current analysis are not health-based advisory levels to guide homeland security responses. This integrated evaluation of chronic public benchmarks and contaminant fate has identified more than 200 risk-based criteria as method validation targets across numerous contaminants and fate products in drinking water and air combined. The gap in directly applicable values is considerable across the full set of threat contaminants, so preliminary indicators were ...
Date: February 18, 2009
Creator: MacDonell, M.; Bhattacharyya, M.; Finster, M.; Williams, M.; Picel, K.; Chang, Y.-S. et al.
Partner: UNT Libraries Government Documents Department

Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Remedial investigation results

Description: This report presents the results of the remedial investigation (RI) conducted at J-Field in the Edgewood Area of Aberdeen Proving Ground (APG), a U.S. Army installation located in Harford County, Maryland. Since 1917, activities in the Edgewood Area have included the development, manufacture, and testing of chemical agents and munitions and the subsequent destruction of these materials at J-Field by open burning and open detonation. These activities have raised concerns about environmental contamination at J-Field. This RI was conducted by the Environmental Conservation and Restoration Division, Directorate of Safety, Health and Environmental Division of APG, pursuant to requirements outlined under the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). The RI was accomplished according to the procedures developed by the U.S. Environmental Protection Agency (EPA 1988). The RI provides a comprehensive evaluation of the site conditions, nature of contaminants present, extent of contamination, potential release mechanisms and migration pathways, affected populations, and risks to human health and the environment. This information will be used as the basis for the design and implementation of remedial actions to be performed during the remedial action phase, which will follow the feasibility study (FS) for J-Field.
Date: March 14, 2000
Creator: Yuen, C. R.; Martino, L. E.; Biang, R. P.; Chang, Y. S.; Dolak, D.; Van Lonkhuyzen, R. A. et al.
Partner: UNT Libraries Government Documents Department

Environmental impacts of options for disposal of depleted uranium tetrafluoride (UF{sub 4}).

Description: The U.S. Department of Energy (DOE) evaluated options for managing its depleted uranium hexafluoride (UF{sub 6}) inventory in the Programmatic Environmental Impact Statement for the Long-Term Management and Use of Depleted Uranium Hexafluoride (PEIS) of April 1999. Along with the impacts from other management options, the PEIS discussed the environmental impacts from the disposal of depleted uranium oxide, which could result from the chemical conversion of depleted UF{sub 6}. It has been suggested that the depleted UF{sub 6} could also be converted to uranium tetrafluoride (UF{sub 4}) and disposed of. This report considers the potential environmental impacts from the disposal of DOE's depleted UF{sub 6} inventory after its conversion to UF{sub 4}. The impacts were evaluated for the same three disposal facility options that were considered in the PEIS for uranium oxide: shallow earthen structures, belowground vaults, and mines. They were evaluated for a dry environmental setting representative of the western United States. To facilitate comparisons and future decision making, the depleted UF{sub 4} disposal analyses performed and the results presented in this report are at the same level of detail as that in the PEIS.
Date: July 2, 2001
Creator: Monette, F. A.; Allison, T.; Avci, H. I.; Biwer, B. M.; Butler, J. P.; Chang, Y.-S. et al.
Partner: UNT Libraries Government Documents Department