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161.
Clayton W. Ogg Gary A. Keith 《Journal of the American Water Resources Association》2002,38(2):577-586
ABSTRACT: In the past five years, USDA and EPA programs became major players in implementing watershed programs. The 1996 Farm Bill for the first time required that USDA assistance for farmers address priority environmental needs on a site‐specific, or watershed, basis. USDA involves farmers and other players in locally run watershed programs and focuses cost share and incentive payments on nutrient planning, riparian protection, and other practices prioritized to most efficiently achieve watershed goals. As a result, USDA has become a funding source for environmental initiatives targeted to watersheds, as well as a technical resource that attempts to support more efficient use of federal and state environmental expenditures. Analysis identifies institutional and technical barriers to targeting the very limited, new assistance and suggests how those barriers are being addressed by some innovative programs. Since Total Maximum Daily Load (TMDL) and other state run programs face many of the same challenges of ranking watersheds, setting goals, and finding cost effective remedies, this paper identifies a very close fit between the new federal programs and other watershed programs. 相似文献
162.
Anita Broughton Andrea Sepulveda Keith Foster Taras Kruk Michael G. Nickelsen Maleya Gillan Thomas K.G. Mohr 《补救:环境净化治理成本、技术与工艺杂志》2019,29(4):49-63
The synthetic chemical, 1,4‐dioxane, is classified by the U.S. Environmental Protection Agency (EPA) as a probable human carcinogen. Between 2013 and 2015, the EPA detected 1,4‐dioxane in public drinking water supplies in 45 states at concentrations up to 33 µg/L and in groundwater from releases at hazardous waste sites across the United States. Although a Federal maximum contaminant level drinking water standard has not yet been proposed, state‐specific standards and criteria are as low as 0.3 µg/L. 1,4‐Dioxane is a recalcitrant chemical in that applications of conventional treatment technologies have had limited success in reducing concentrations in water to meet current and proposed health‐protective levels. Although mainly used as a stabilizer for the solvent 1,1,1‐trichloroethane, it has been used in other industrial processes and has been detected in a variety of consumer products, such as foods, pharmaceuticals, cosmetics, and detergents. The high aqueous solubility of 1,4‐dioxane coupled with limited solubility of chlorinated solvents typically found in conjunction with 1,4‐dioxane contamination is the primary reason for its treatment challenges. In the last several years, an alternative, cost‐effective technology has been developed that has demonstrated treatment to levels significantly lower than the Federal and state‐specific goals. This article provides a Federal and state‐by‐state summary of 1,4‐dioxane‐specific drinking water and groundwater concentration criteria and qualitative comparison of the effectiveness of conventional treatment technologies compared to the effectiveness of an alternative treatment technology. A case study is also provided to present details regarding the application of an alternative treatment technology at an active groundwater remediation site in California. 相似文献
163.
This paper draws on climate justice principles developed in the context of international negotiations between national governments to assess the distribution of carbon reduction roles between different actors involved in residential energy use within the UK. In so doing, it aims to provide a new understanding of equity aspects of current residential policy and to highlight opportunities for more effective and equitable policy. The paper uses three criteria: rights and corresponding duties; mitigation responsibilities and capabilities. It applies them systematically to assess the roles of five key actors involved in residential energy use in the UK. The assessment finds a suboptimal distribution of actors’ duties, responsibilities and capabilities and roles and discusses whether and how a more effective and fair allocation of outcomes, in terms of carbon reduction and fuel poverty, could be achieved. In particular, it raises questions about whether the right actors are being legally obliged or incentivised to deliver energy efficiency improvements, and suggests that particular actors – local authorities and community groups – are under-used and require greater government support with capability. The paper represents the first use of international climate justice frameworks to investigate residential energy policy within a country. 相似文献
164.
Carol C. House J. Jeffery Goebel Hans T. Schreuder Paul H. Geissler William R. Williams Anthony R. Olsen 《Environmental monitoring and assessment》1998,51(1-2):451-463
A demonstration project in Oregon examined the feasibility of combining Federal environmental monitoring surveys. An integrated approach should remove duplication of effort and reduce the possibility of providing apparently conflicting information to policy makers and the public. Data collection teams made photo interpretation measurements and on-site soil/vegetation/animal observations at locations that were selected from the Forest Inventory and Analysis (FIA), National Forest System (NFS) Region 6, and National Resource Inventory (NRI) surveys in a six-county area in Northern Oregon. The project demonstrated the feasibility of conducting a combined FIA/NFS/NRI survey and suggests an approach that will preserve the utility of the critical historical information from these surveys. We suggest a framework for estimating the extent of forest and range land that explains FIA/NRI differences and provides a common basis for both surveys. We suggest indicator and protocol criteria that will allow consistent national and regional estimates over all vegetation types, and stress the importance of including measurement repeatability in the design of the combined survey. 相似文献
165.
Keith A. Grasman Patrick F. Scanlon Glen A. Fox 《Environmental monitoring and assessment》1998,53(1):117-145
During the 1950s and 1960s, reproductive failures and population declines were observed in fish-eating birds such as gulls, terns, cormorants, herons, and eagles in the Great Lakes. DDE-induced eggshell thinning contributed to these declines, but other factors such as embryo toxicity also were implicated. With reduced releases of many pollutants, reproduction recovered in some species. However, biomonitoring during the 1980s and 1990s indicates continuing effects at highly contaminated sites. Improved analytical techniques and bioassays have allowed the assessment of the total dioxin-like toxicity of complex mixtures of organochlorines (TCDD-equivalents). Developmental defects such as embryo mortality, deformities, and edema have been associated with dioxin-like PCBs in several avian species. Improved biochemical techniques have allowed the measurement of biomarkers that detect physiological alterations associated with contaminants. Specific biomarkers studied in Great Lakes birds include cytochrome P-450 monooxygenases, highly carboxylated porphyrins, thyroxine, vitamin A, and immune function. Reproductive and physiological alterations are associated with population-level effects in Caspian terns and bald eagles that feed on highly contaminated fish. Biomonitoring using biomarkers and population-level measures in fish-eating birds will continue to be important for assessing the effects of contaminants on the Great Lakes ecosystem. 相似文献
166.
Sather ME Slonecker ET Kronmiller KG Williams DD Daughtrey H Mathew J 《Journal of environmental monitoring : JEM》2006,8(5):558-563
Passive Sampling Devices (PSDs) have been successfully used by government and academic agencies to monitor common ambient air pollutants such as ozone and nitrogen dioxide (NO(2)). Most PSD studies have involved long-term (e.g. bi-weekly or monthly) sampling. But the Passive Ozone Network of Dallas (POND) studies of 1998 and 1999 showed that high quality 24-hour and 12-hour data using the Ogawa PSD could be collected for ambient ozone concentrations. This paper presents an evaluation of short-term passive sampling results for nitrogen oxides (NO(x)) in El Paso and Houston, Texas, using the Ogawa PSD. The Ogawa NO(x) PSDs were compared to both Federal Reference Method (FRM) monitors and a photolytic converter, with the photolytic converter designed to report closer concentrations to "true" NO(x) by more effectively limiting the interferences of other nitrogen species. Overall, good agreement was noted for all three monitor types in both cities, supporting the potential use of lower cost Ogawa PSDs for large multi-site episodic NO(x)/NO(2)/NO saturation screening studies. This evaluation was conducted during two separate six week periods of the cooler winter months so additional testing of the Ogawa PSDs during different seasons is recommended. 相似文献
167.
W. Keith Taulbee Christopher T. Nietch Donald Brown Balaji Ramakrishnan M. Jackie Tompkins 《Journal of the American Water Resources Association》2009,45(4):907-927
Abstract: A stream mesocosm experiment was conducted to study the ecosystem‐wide effects of two replicated flow hydrograph treatments programmed in an attempt to compare a simulated predevelopment condition to the theoretical changes that new development brings, while accounting for engineering design criteria for urban stormwater management. Accordingly, the treatments (three replicates each) differed in base flow between events and in the rise to, fall from, and duration of peak flow during simulated storm hydrographs, which were triggered by real rain events occurring outside over a 96‐day period from summer to fall, 2005. Incident irradiance, initial substrate quality, and water quality were similar between treatments. Sampling was designed to study the interactions among the treatment flow dynamics, sediment transport processes, streambed nutrients, and biotic structure and function. What appeared most important to the overall structure and function of the mesocosm ecosystems beyond those changes resulting from natural seasonality were (1) the initial mass of fines that infiltrated into the gravel bed, which had a persistent effect on nitrogen biogeochemistry and (2) the subsequent fine sediment accumulation rate, which was unexpectedly similar between treatments, and affected the structure of the macroinvertebrate community equally as the experiment progressed. Invertebrate taxa preferring soft beds dominated when the gravel was comprised of 5‐10% fines. The dominant invertebrate algal grazer had vacated the channels when fines exceeded 15%, but this effect could not be separated from what appeared to be a seasonal decline in insect densities over the course of the study. Neither hydrograph treatment allowed for scour or other potential for flushing of fines. This demonstrated the potential importance of interactions between hydrology and fine sediment loading dynamics on stream ecosystems in the absence of flows that would act to mobilize gravel beds. 相似文献
168.
Jacqueline D. Sharp Mark K. Jaccard David W. Keith 《International Journal of Greenhouse Gas Control》2009,3(5):641-651
Carbon capture and storage (CCS) may play a central role in managing carbon emissions from the power sector and industry, but public support for the technology is unclear. To address this knowledge gap, and to test the use of discrete choice analysis for determining public attitudes, two focus groups and a national survey were conducted in Canada to investigate the public's perceptions of the benefits and risks of CCS, the likely determinants of public opinion, and overall support for the use of CCS.The results showed slight support for CCS development in Canada, and a belief that CCS is less risky than normal oil and gas industry operations, nuclear power, or coal-burning power plants. A majority of respondents indicate that they would support the use of CCS as part of a greenhouse gas reduction strategy, although it would likely have to be used in combination with energy efficiency and alternative energy technologies in order to retain public support. 相似文献
169.
Rachel C. Walton Keith N. White 《Environmental pollution (Barking, Essex : 1987)》2009,157(7):2142-2146
The amount of toxic metal accumulated by an organism is often taken as an indicator of potential toxicity. We investigated this relationship in the freshwater snail, Lymnaea stagnalis, exposed to 500 μg l−1 Al over 30 days, either alone or in the presence of phosphate (500 μg l−1 P) or a fulvic acid surrogate (FAS; 10 mg l−1 C). Behavioural activity was assessed and tissue accumulation of Al quantified. Lability of Al within the water column was a good predictor of toxicity. FAS increased both Al lability and behavioural dysfunction, whereas phosphate reduced Al lability, and completely abolished Al-induced behavioural toxicity. Tissue accumulation of Al was not linked to toxicity. Higher levels of Al were accumulated in snails exposed to Al + P, compared to those exposed to Al alone, whereas FAS reduced Al accumulation. These findings demonstrate that the degree of tissue accumulation of a metal can be independent of toxicity. 相似文献
170.
Charlie M. Shackleton Fiona Parkin Maphambe I. Chauke Linda Downsborough Ashleigh Olsen Gregg Brill Craig Weideman 《Environment, Development and Sustainability》2009,11(2):229-240
Harvesting of non-timber forest products is an integral component of rural livelihoods throughout the developing world. At
times this is at odds with conservation objectives. Reconciliation of the two requires examination of local level contexts
and needs. This paper reports on the harvesting needs for Ischyrolepis by a rural community in South Africa, against the setting that they had recently been prohibited from harvesting by the local
conservation officials. Interviews were conducted with conservation officials to understand the reasoning for the prohibition.
Local demand for Ischyrolepis was assessed by household surveys, as well as in-depth interviews with traders. The density and size class distribution of
Ischyrolepis was determined using transects. The total annual demand for Ischyrolepis was determined to be approximately only 2.7% of the standing crop. The bulk of the annual demand was for small-scale trade,
the income from which was a primary source of income for the few harvesters. Very little evidence could be found indicating
that harvesting was damaging the resource or its habitat, and local knowledge suggested that the abundance of the species
was stimulated by harvesting. Even if market demand were to increase, the size of the shoots required means that less than
20% of the standing crop could be harvested annually. Current regulations around harvesting are in a state of revision, and
hence confusion prevails regarding if harvesting is permissible, and if so, under what conditions, which is detrimental to
both conservation and livelihoods.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献