A jointly prepared, interagency (US Environmental Protection Agency [USEPA] and the US Nuclear Regulatory Commission [USNRC]), §316(a) Technical Guidance Manual has been the primary guide to ecological studies of thermal discharges at... more
A jointly prepared, interagency (US Environmental Protection Agency [USEPA] and the US Nuclear Regulatory Commission [USNRC]), §316(a) Technical Guidance Manual has been the primary guide to ecological studies of thermal discharges at power plants since 1977. It reflected contemporary ecological theory, which assumed that undisturbed populations and ecosystems possessed a balanced and relatively unchanging structure and function that could be disrupted by addition of heat from a thermal discharge. It was intended primarily to facilitate the licensing of proposed nuclear power plants and thus focused on predictive assessments. Since 1977, however, scientific and regulatory contexts of §316(a) assessments have changed. Ecologists abandoned the notion of "balance" in populations and ecosystems and now recognize that natural systems are always changing spatially and temporally. Regulatory emphasis has shifted from predictive assessments at new plants, largely based on thermal-tolerance laboratory data, to retrospective assessments based on field data at operating plants. We suggest updates to thermal-assessment studies based on modern ecological theory and recent thermalassessment practice. The concepts we outline are fully consistent with statutory language and may assist in design and implementation of study plans by applicants. their consultants, development of discharge permits by USEPA or state agencies, and reviews of assessment documents by interested public and environmental organizations.
I would like to acknowledge the funding for this project generously provided by The Dow Chemical Company (Dow), The University Consortium for Field-Focused Groundwater Contamination Research directed by Dr. Cherry, The Natural Sciences... more
I would like to acknowledge the funding for this project generously provided by The Dow Chemical Company (Dow), The University Consortium for Field-Focused Groundwater Contamination Research directed by Dr. Cherry, The Natural Sciences and Engineering Research Council of Canada (NSERC) Industrial Research Chair held by Dr. Parker and Landesanstalt fur Altlastenfreistellung des Landes Sachsen-Anhalt (LAF). In addition, in-kind support was provided by FLUTe™, Solinst Canada Ltd. and Golder Associates Ltd.
ABSTRACTA wide range of anthropogenic activities have caused various problems to the aquatic environment, leading to economic, social, and environmental losses. The use of materials for the recovery of water quality is very important due... more
ABSTRACTA wide range of anthropogenic activities have caused various problems to the aquatic environment, leading to economic, social, and environmental losses. The use of materials for the recovery of water quality is very important due to the water scarcity scenario present in different parts of the world. The use of sawdust as an organic adsorbent for P removal in eutrophic environments attempts to address both water quality preservation and possible application of the organic adsorbent as fertilizer for agricultural practices. This use will result in important contributions to the water and food security. In this work, we performed laboratory experiments to study P adsorption and to evaluate possible adsorption of metals and emerging contaminants by sawdust. The experiments were carried out in 36 microcosms (glass jars), using 50% of the flasks as treatments (containing bags with sawdust) and the rest of the flasks as control (water and sediment without sawdust). For future appl...
report is based on risk estimates prepared by the University of California, Davis (UC Davis) at the Laboratory for Energy-Related Health Research (LEHR or the Site). ” As discussed in DSCSOC comments, some of the UCD risk estimates are... more
report is based on risk estimates prepared by the University of California, Davis (UC Davis) at the Laboratory for Energy-Related Health Research (LEHR or the Site). ” As discussed in DSCSOC comments, some of the UCD risk estimates are based on technically invalid approaches such as the use of cooccurrence-based sediment quality guidelines. This issue is discussed further below. Further, the risk estimates are based on a limited set of constituents of concern compared to the vast number of potentially hazardous chemicals at the LEHR Superfund site. These issues have been discussed in detail in comments of provided to the RPMs, and UCD and DOE as responsible parties. The comments are on the DSCSOC website,
Years of production of radioactive materials at the Hanford Site in southeastern Washington State has resulted in contamination of surface, subsurface, and surface water environments. Cleanup of the site has been aided by various tools,... more
Years of production of radioactive materials at the Hanford Site in southeastern Washington State has resulted in contamination of surface, subsurface, and surface water environments. Cleanup of the site has been aided by various tools, including computer software used to predict contaminant migration in the future and estimate subsequent impacts. The System Assessment Capability (SAC) is a total systems tool designed to simulate the movement of contaminants from all waste sites at Hanford through the vadose zone, the unconfined aquifer, and the Columbia River. Except for iodine-129, most of the contaminants modeled by SAC have acceptably matched field measurements. The two most likely reasons for the inconsistency between the measured field data and SAC modeled predictions are an underestimated inventory and an overestimated sorption value (Kd). Field data tend to be point measurements taken from near the surface of the unconfined aquifer. Thus, the depth of the iodine-129 contamin...
ABSTRACT In the early days of North America settlement industry was encouraged by government to utilize natural resources and bring development and wealth to communities. As populations grew and other demands developed, regulations were... more
ABSTRACT In the early days of North America settlement industry was encouraged by government to utilize natural resources and bring development and wealth to communities. As populations grew and other demands developed, regulations were created to protect natural resources for multiple uses. Industry then argued that environmental regulations increased costs and reduced their ability to compete nationally and internationally. It is only over the last 50 years that environmental regulations and legal precedents have placed substantial responsibility for the protection of natural resources on industry. In recent decades, product advertising and marketing has engaged the consumer as another stakeholder in shaping industry's attitude regarding environmental management and protection. The financial model for business has expanded with a growing economy and an increase in stakeholders. Fuller cost accounting incorporating the expense and benefit of environmental protection and remediation has changed the equation of profitability. Convergence of the corporate need to make a profit for investors together with meeting consumer environmental needs will continue toward the common goal of economic sustainability.
In recent months remediation activities at Hanford 100 Area siteslocated along the shores of the Columbia River near Richland, Washingtonhave accelerated in order to protect aquatic species from discharges of hexavalent chromium (CrVI).... more
In recent months remediation activities at Hanford 100 Area siteslocated along the shores of the Columbia River near Richland, Washingtonhave accelerated in order to protect aquatic species from discharges of hexavalent chromium (CrVI). These activities ...
Dear Mr. Lux: Enclosed is a summary of the subject meeting and the U.S. Nuclear Regulatory Commission staff’s recommendations for a path forward for each of the groups of deficiencies that were discussed at the meeting. If you have any... more
Dear Mr. Lux: Enclosed is a summary of the subject meeting and the U.S. Nuclear Regulatory Commission staff’s recommendations for a path forward for each of the groups of deficiencies that were discussed at the meeting. If you have any questions regarding this letter, please contact me at (301) 415-6664 or by e-mail at klk@nrc.gov. Sincerely, /RA/
A number of waste trenches at cribs at Hanford's BC Cribs and Trenches site, which received about 10 Mgal of scavenged tank waste with elevated concentrations of technetium-99 and nitrate, are currently being evaluated for... more
A number of waste trenches at cribs at Hanford's BC Cribs and Trenches site, which received about 10 Mgal of scavenged tank waste with elevated concentrations of technetium-99 and nitrate, are currently being evaluated for remediation. The objective of this study was to investigate the influence of fine-scale heterogeneity (i.e. horizontal laminations, cross-bedding) on the large-scale transport behavior of mobile contaminants through the vadose zone with the purpose of developing a remedial strategy. The vertical heterogeneity structure, conditioned on grain size distributions and geophysical logs (water content and natural isotopes), was developed from a single borehole at the site. Geostatistical methods were used to impose the 3-D spatial correlation structure from the nearby well-characterized experimental site to merge the heterogeneities at various scales. Flow and transport properties were derived using physically-based property transfer models. The STOMP simulator was t...
In recent months remediation activities at Hanford 100 Area sites – located along the shores of the Columbia River near Richland, Washington – have accelerated in order to protect aquatic species from discharges of hexavalent chromium... more
In recent months remediation activities at Hanford 100 Area sites – located along the shores of the Columbia River near Richland, Washington – have accelerated in order to protect aquatic species from discharges of hexavalent chromium (CrVI). These activities have focused on expanding existing groundwater pump-and-treat remedies, together with pilot-testing complementary in situ technologies. Comparative analyses of remedial alternatives within the context of remedial process optimization led by CH2M HILL Plateau Remediation Company (CHPRC) employed groundwater flow, particle tracking, and transport modeling using MODFLOW, MODPATH, and MT3DMS, respectively. As the conceptual site models for each of the groundwater operable units have developed, so too has the representation of the key features and processes within the numerical model. Herein the initial model construction and calibration are described and then the stepwise integration of several features and processes are presented,...
Intrusive characterization was conducted to obtain data and information needed for planning remediation strategies for the Hanford Site’s 618-10 burial ground trenches, which contain very high dose rate and very highly alpha contaminated... more
Intrusive characterization was conducted to obtain data and information needed for planning remediation strategies for the Hanford Site’s 618-10 burial ground trenches, which contain very high dose rate and very highly alpha contaminated items. The term “intrusive” is used to distinguish these activities from previously conducted “non-intrusive” characterization, which was performed without exposing personnel or the environment to waste material. Planning for remediation requires better understanding of the type, quantity, and condition of the materials deposited into the trenches than has been obtained through record searches and previous nonintrusive characterization activities. Intrusive characterization is defined as characterization activities that will remove materials for sampling and analysis from within selected 618-10 Burial Ground trenches. Exploratory test pitting was performed with excavations up to 6 meters deep and approximately 2 meters wide (at the base) and cross c...
The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. The findings of... more
The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. The findings of this report are not to be construed as an official Department of the Army position, unless so desig-nated by other authorized documents. Dredging Operations and Environmental Research Program
: The high cost of chemical analyses and bioassays of dredged material makes it necessary for decision makers to limit testing to that which will sufficiently characterize the sediment to evaluate a selected disposal alternative. This... more
: The high cost of chemical analyses and bioassays of dredged material makes it necessary for decision makers to limit testing to that which will sufficiently characterize the sediment to evaluate a selected disposal alternative. This report offers guidance for limiting the amount of testing necessary and considers other factors that could potentially reduce the cost of testing dredged material. The importance of an initial site evaluation to reduce the extent of dredged material testing is stressed. Unless a reason to believe that contamination exists can be established through examination of historical data and other site characteristics, no testing is warranted. The need for testing can sometimes be eliminated by examination of regulatory criteria for categorical exclusions, i.e., circumstances under which no testing is required. Additional cost savings can sometimes be generated during the scoping process by amelioration of the concerns of interested parties prior to preparation...
