Six rainfall events were intensively sampled below a mixed hardwood forest canopy in central Pennsylvania to determine sample size requirements for estimation of thronghfall volumes and ionic concentrations. Evaluation of the ionic parameters of thronghfall revealed that the concentrations of most major ions were nonnormally distributed. Differences in the distributions of concentrations were found to occur between ions as well as between storms. Significant departures from normality were mainly due to right‐skewness. Only H+ exhibited a left skewed sample distribution. None of the basic transformations were effective in normalizing all parameters. A high degree of spatial variability was observed for each of the chemical parameters. Nitrate and hydrogen ions (NO−3 and H+), were found to be the least variable, whereas vegetatively mobile ions such as K+ and Mg2+ exhibited the greatest variability. Because of high event‐to‐event variation in the distributions of ion concentrations, specific sample‐size requirements should be estimated for each ion through preliminary sampling of thronghfall precipitation from several storms.
The DOE Biomass Program recently implemented the Biofuels Initiative, or 30x30 program, with the dual goal of reducing U.S. dependence on foreign oil by making cellulosic ethanol cost competitive with gasoline by 2012 and by replacing 30 percent of gasoline consumption with biofuels by 2030.Experience to date with increasing ethanol production suggests that it distorts agricultural markets and therefore raises concerns about the sustainability of the DOE 30x30 effort: Can the U.S. agricultural system produce sufficient feedstocks for biofuel production and meet the food price and availability expectations of American consumers without causing environmental degradation that would curtail the production of both food and fuel?Efforts are underway to develop computer-based modeling tools that address this concern and support the DOE 30x30 goals. Beyond technical agronomic and economic concerns, however, such models must account for the publics' growing interest in sustainable agriculture and in the reduction of greenhouse gas emissions. This paper discusses ongoing work at the Center for Advanced Energy Studies that investigates the potential consequences and longterm sustainability of projected biomass harvests by identifying and incorporating "sustainable harvest indicators" in a computer modeling strategy.
This document contains new concepts or the author(s) interpretation of new calculations andlor measurements; accordingly, EG&G Idaho, Inc. is required by the United States Government to include the following disclaimer: ,C i ilul i i i ii Iii iiiiii i DISCLAIMER w This reportwas preparedas an accountof won sponsoredby an agency of the UnitedStatesGovernment. Neither the UnitedStatesGovernmentnorany agency thereof, nor any of their employees, makes any warranty,express or implied, or assumes any legal liabilityor responsibilityfor the accuracy,completeness,or usefulness of any information, apparatus, product or process disclosed, or representsthat Itsuse wouldnotinfringeprivatelyownedrights. Referencesherein to any specificcommercialproduct, process,or serviceby tradename, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation,or favoringbythe UnitedStatesGovernmentorany agency thereof. The views and opinionsof authors expressed herein do not necessarilystate or reflect thoseof the United States Governmentor any agency thereof.
Contaminants remaining onsite after regulatory-approved environmental remediation operations are complete represent continued risk to human health and the environment. Many sites require continued management efforts to: (1) protect the integrity of the engineered remedy/control, (2) limit the exposure of individuals to residual contamination by limiting reuse activities, (3) maintain ready access to accurate records/information, and (4) INTRODUCTIONThe return of environmentally contaminated sites to pristine conditions is often not achievable (National Research Council [NRC], 2000). Many of today's waste management techniques do not eliminate contaminants, such as hazardous and radioactive waste, but rather only concentrate and/or attempt to contain the contaminants of concern (Applegate & Dycus, 1998; NRC, 1997;Rumer & Mitchell, 1995;Russell, 2000;Suter, Luxmoore, & Smith, 1993; US EPA, 1998). Remedial decisions concerning these complex challenges often focus on mitigation actions to reduce risk (Burger, 2004b;Greenberg et al., 2002;Mayer, Faass, Greenberg, & Lewis, 2006). However, risks to human health and the environment frequently remain at many sites even after regulatory-approved environmental remediation operations are complete (US DOE, 1997DOE, , 1999DOE, , 2001. The resulting risks are associated with the residual wastes left in place or disposed of onsite in shallow burial cells, as well as residual contamination of soils, facilities, surface water, and groundwater.This article examines two prevailing management approaches for addressing the risks associated with long-term contaminant isolation. These approaches are illustrated through a series of case studies. Sacrifice zones are shown to be sites that are purposefully isolated to prevent human access onto the property. An alternative approach is illustrated at controlled reuse sites, where access is limited to specific use. Both of these management 75Managing Residual Contaminants-Reuse and Isolation Case Studies approaches employ a series of engineered and institutional controls to minimize potential exposure and associated risk. APPLICABLE U.S. REGULATIONSThe United States is addressing radioactive and hazardous waste problems by enforcing a variety of environmental regulations (the Comprehensive Environmental Response, Compensation, and Liability Act [CERCLA]; the Resource Conservation and Recovery Act [RCRA]; the Uranium Mill Tailings Radiation Control Act [UMTRCA]; and the Small Business Liability Relief and Brownfields Revitalization Act). Of particular significance is CERCLA, as amended, which establishes the framework for the federal response to the release of hazardous substances that endanger public health or the environment.The US EPA has the primary authority for implementing the provisions of CERCLA. It does so via the Superfund program that has two primary areas of focus: the long-term cleanup of contaminated sites and an emergency response program (US EPA, 2004c). As a way of prioritizing the program's work, the US EPA establishe...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.