Browsing by Subject "Water Supply"

Now showing 1 - 6 of 6
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    Demand Management Strategies of North Carolina Public Water Systems
    (2008-04-22T19:18:30Z) Childs, Rush
    The traditional approach to water resources management in the Southeastern United States does not take full advantage of economic tools for managing scarcity. It fails to prevent economically inefficient uses of water, imposes additional costs to downstream users, and degrades the natural environment. The recent drought in the Southeastern United States reveals these shortcomings and indicates that water supply planners should be aware of the role of demand management in reducing waste and misallocation during times of water stress. This analysis draws on data from the State of North Carolina’s Local Water Supply Plan Database. In the absence of statewide standards for technical and economic efficiency, it examines the decision of public water systems to voluntarily adopt demand management practices. An empirical model of water use is then estimated to determine the effectiveness of current demand management strategies, as employed by North Carolina public water systems. Results of the analysis confirm the view held by experts; individual demand management strategies are context-specific and should be adopted with careful attention to local conditions. In North Carolina, the degree of demand management pursued by public systems reflects a policy choice of system managers, customers, and decision makers. River basin planning is also shown to positively affect the degree of demand management pursued by public systems. A model estimating overall system demand shows that conservation pricing can be effective at reducing levels of water use; however, estimating the effectiveness of demand management strategies is complicated by a lack of criteria for determining systems’ program participation.
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    Desalination and transboundary water governance in conflict settings.
    (Journal of environmental management, 2024-03) Walschot, Maureen; Katz, David
    Desalination can reduce both water scarcity and variability in supplies, two factors identified as drivers of transboundary water conflict. As such, some have predicted that increasing development of desalination capacity may reduce conflict over shared waters. Others have claimed that desalination may become a source of new conflicts. Additionally, desalination may open up new avenues for cooperation, but also may allow for unilateral action by parties, thereby decreasing cooperation. This study looks at the impact of the introduction of desalination on hydro-political relations in two protracted conflict settings: the island of Cyprus and the Arab-Israeli conflict. Using both quantitative and qualitative assessments, we find that desalination has fundamentally altered hydro-political relations, but find no consistent trends in terms of levels of conflict and cooperation. These findings suggest that the influence of desalination on hydro-political relations is likely to be a function of, rather than a transformer of, the larger geopolitical context.
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    Environmental Impacts of the Coal Ash Spill in Kingston, Tennessee: An 18-Month Survey
    (2010) Ruhl; L; Vengosh, A; Dwyer; G, S; Hsu-Kim; H; Deonarine
    An 18 month investigation of the environmental impacts of the Tennessee Valley Authority (TVA) coal ash spill in Kingston, Tennessee combined with leaching experiments on the spilled TVA coal ash have revealed that leachable coal ash contaminants (LCACs), particularly arsenic, selenium, boron, strontium, and barium, have different effects on the quality of impacted environments. While LCACs levels in the downstream river water are relatively low and below the EPA drinking water and ecological thresholds, elevated levels were found in surface water with restricted water exchange and in pore water extracted from the river sediments downstream from the spill. The high concentration of arsenic (up to 2000 mu g/L) is associated with some degree of anoxic conditions and predominance of the reduced arsenic species (arsenite) in the pore waters. Laboratory leaching simulations show that the pH and ash/water ratio control the LCACs' abundance and geochemical composition of the impacted water. These results have important implications for the prediction of the fate and migration of LCACs in the environment, particularly for the storage of coal combustion residues (CCRs) in holding ponds and landfills, and any potential CCRs effluents leakage into lakes, rivers, and other aquatic systems.
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    Physical and economic potential of geological CO2 storage in saline aquifers.
    (Environ Sci Technol, 2009-03-15) Eccles, Jordan K; Pratson, Lincoln; Newell, Richard G; Jackson, Robert B
    Carbon sequestration in sandstone saline reservoirs holds great potential for mitigating climate change, but its storage potential and cost per ton of avoided CO2 emissions are uncertain. We develop a general model to determine the maximum theoretical constraints on both storage potential and injection rate and use it to characterize the economic viability of geosequestration in sandstone saline aquifers. When applied to a representative set of aquifer characteristics, the model yields results that compare favorably with pilot projects currently underway. Over a range of reservoir properties, maximum effective storage peaks at an optimal depth of 1600 m, at which point 0.18-0.31 metric tons can be stored per cubic meter of bulk volume of reservoir. Maximum modeled injection rates predict minima for storage costs in a typical basin in the range of $2-7/ ton CO2 (2005 U.S.$) depending on depth and basin characteristics in our base-case scenario. Because the properties of natural reservoirs in the United States vary substantially, storage costs could in some cases be lower or higher by orders of magnitude. We conclude that available geosequestration capacity exhibits a wide range of technological and economic attractiveness. Like traditional projects in the extractive industries, geosequestration capacity should be exploited starting with the low-cost storage options first then moving gradually up the supply curve.
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    Physical and economic potential of geological CO2 storage in saline aquifers.
    (Environ Sci Technol, 2009-03-15) Eccles, JK; Jackson, Robert; Newell, Richard G; Pratson, L
    Carbon sequestration in sandstone saline reservoirs holds great potential for mitigating climate change, but its storage potential and cost per ton of avoided CO2 emissions are uncertain. We develop a general model to determine the maximum theoretical constraints on both storage potential and injection rate and use it to characterize the economic viability of geosequestration in sandstone saline aquifers. When applied to a representative set of aquifer characteristics, the model yields results that compare favorably with pilot projects currently underway. Over a range of reservoir properties, maximum effective storage peaks at an optimal depth of 1600 m, at which point 0.18-0.31 metric tons can be stored per cubic meter of bulk volume of reservoir. Maximum modeled injection rates predict minima for storage costs in a typical basin in the range of $2-7/ ton CO2 (2005 U.S.$) depending on depth and basin characteristics in our base-case scenario. Because the properties of natural reservoirs in the United States vary substantially, storage costs could in some cases be lower or higher by orders of magnitude. We conclude that available geosequestration capacity exhibits a wide range of technological and economic attractiveness. Like traditional projects in the extractive industries, geosequestration capacity should be exploited starting with the low-cost storage options first then moving gradually up the supply curve.
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    Reduction in urinary arsenic levels in response to arsenic mitigation efforts in Araihazar, Bangladesh.
    (Environ Health Perspect, 2007-06) Chen, Yu; van Geen, Alexander; Graziano, Joseph H; Pfaff, Alexander; Madajewicz, Malgosia; Parvez, Faruque; Hussain, AZM Iftekhar; Slavkovich, Vesna; Islam, Tariqul; Ahsan, Habibul
    BACKGROUND: There is a need to identify and evaluate an effective mitigation program for arsenic exposure from drinking water in Bangladesh. OBJECTIVE: We evaluated the effectiveness of a multifaceted mitigation program to reduce As exposure among 11,746 individuals in a prospective cohort study initiated in 2000 in Araihazar, Bangladesh, by interviewing participants and measuring changes in urinary As levels. METHODS: The interventions included a) person-to-person reporting of well test results and health education; b) well labeling and village-level health education; and c) installations of 50 deep, low-As community wells in villages with the highest As exposure. RESULTS: Two years after these interventions, 58% of the 6,512 participants with unsafe wells (As >/=50 microg) at baseline had responded by switching to other wells. Well labeling and village-level health education was positively related to switching to safe wells (As < 50 mug/L) among participants with unsafe wells [rate ratio (RR) = 1.84; 95% confidence interval (CI), 1.60-2.11] and inversely related to any well switching among those with safe wells (RR = 0.80; 95% CI, 0.66-0.98). The urinary As level in participants who switched to a well identified as safe (< 50 microg As/L) dropped from an average of 375 microg As/g creatinine to 200 microg As/g creatinine, a 46% reduction toward the average urinary As content of 136 microg As/g creatinine for participants that used safe wells throughout. Urinary As reduction was positively related to educational attainment, body mass index, never-smoking, absence of skin lesions, and time since switching (p for trend < 0.05). CONCLUSIONS: Our study shows that testing of wells and informing households of the consequences of As exposure, combined with installation of deep community wells where most needed, can effectively address the continuing public health emergency from arsenic in drinking water in Bangladesh.