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1.
ABSTRACT: This paper summarizes key provisions of the Clinton Administration's proposals for change in the Clean Water Act. Two of the important themes for change are tougher controls for non-point source pollution and the use of market-based instruments. A detailed analysis of market-based abatement suggests limited potential for reducing costs. The keys to nonpoint source pollution control are clearer definition of property rights combined with changes in government programs that encourage polluting activities.  相似文献   

2.
ABSTRACT. The limited success of command-and-control policies for reducing nonpoint source (NPS) water pollution mandated under the Federal Water Pollution Control Act (FWPCA) has prompted increased interest in economic incentive policies as an alternative control mechanism. A variety of measures have been proposed ranging from fairly minor modifications of existing policies to substantial revisions including watershed-wide polices that rely on economic incentives. While greater use of economic incentive policies, such as environmental bonds and point/nonpoint source trading is being advocated in the reauthorization of the CWA, the expected effects of individual proposals will be modest. The characteristics of NPS pollution, namely uncertainty and asymmetrical information, underscores that there is no single, ideal policy instrument for controlling the many types of agricultural NPS water pollution. Some of the usual incentive-based policies, such as effluent taxes, are not well suited to the task. Individual incentive policies proposed for the reauthorized CWA, such as pollution trading or deposit/refund systems, are not broadly applicable for heterogeneous pollution situations. Economic incentive policies may be appropriate in some cases, and command-and-control policies will be preferable in others and may in fact complement incentive policies.  相似文献   

3.
ABSTRACT: EPIC, a soil erosion/plant growth simulation model, is used to simulate nitrogen losses for 120 randomly selected and previously surveyed cropland sites. Simulated nitrogen losses occur through volatilization, surface water and soil runoff, subsurface lateral flow, and leaching. Physical and crop management variables explain a moderate but significant proportion of the variation in nitrogen losses. Site slope and tillage have offsetting effects on surface and ground water losses. Nitrogen applications in excess of agronomic recommendations and manure obtained off the farm and applied to the sites are significant contributors to nitrogen losses. Farm characteristics such as production of confined livestock, total manure nitrogen available, and farm income per cropland acre explain a relatively large portion of the variability in manure nitrogen applied to survey sites. The results help to identify farm characteristics that can be used to target nutrient management programs. Simulation modeling provides a useful tool for investigating variables which contribute to agricultural nitrogen losses.  相似文献   

4.
ABSTRACT: While the quality of rivers has received much attention, the degradation of small streams in upland areas of watersheds has only recently been recognized as a major problem. A major cause of the problem is increases in nonpoint source pollution that accompany urban expansion. A case study is used to examine the potential for storm water detention as a means of controlling water quality in streams of small watersheds. The storm water management basin, which is frequently used to control increases in discharge rates, can also be used to reduce the level of pollutants in inflow to receiving streams. Data collected on a 148-acre site in Maryland shows that a detention basin can trap as much as 98 percent of the pollutant in the inflow. For the 11 water quality parameters, most showed reductions of at least 60 percent, depending on storm characteristics.  相似文献   

5.
ABSTRACT: The Rural Clean Water Program has provided a unique opportunity to study the economics of agricultural nonpoint source pollution control. Several implications for improving the economic efficiency of future agricultural nonpoint source pollution control programs can be drawn from the results. First, individual projects should be targeted towards water bodies that have water quality problems causing economic damages. Considerable variation can exist among areas in the magnitude of economic damages, which may not be proportional to physical impacts. Second, the relative costs and effectiveness of the practices selected to reduce the delivery of pollutants can vary dramatically from one location to another. Early identification and emphasis on cost-effective BMPs can substantially reduce project costs and may make a project economically justifiable that would not otherwise be so. Finally, some projects that do not hive potential economic benefits from water quality improvements exceeding government cost may have on-farm benefits from reduced costs and increased long-term yields that are sufficient to make total benefits (water quality and on-farm) exceed costs.  相似文献   

6.
ABSTRACT: Ground water quality is an environmental issue of national concern. Agricultural activities, because they involve large land areas, often are cited as a major contributor of ground water contaminants. It appears that some degree of ground water contamination from agricultural land use is inevitable, especially where precipitation exceeds evapotranspiration. For this reason, and because agriculture differs significantly from point sources of pollution, farmers, policymakers, and scientists need alternative management strategies by which to protect ground water. Mathematical models coupled to geographic information systems to form expert systems can be important management tools for both policymakers and agricultural producers. An expert system can provide farmers, researchers, and environmental managers with information by which to better manage agricultural production systems to minimize ground water contamination. Significant research is necessary to perfect such a system, necessitating interim ground water management strategies that include not only a strong research program, but educational and public policy components as well.  相似文献   

7.
ABSTRACT: The degree of progress achieved under the 1972 Clean Water Act is reviewed by reference to traditional measures of program implementation, and to evidence of tangible, or “real-world” progress, such as beach closures, drinking water contamination, fishing bans and advisories, species health, and habitat degradation. Significant progress has been made in reducing pollution from point sources, but large point source releases of toxic and other pollutants remain. Little progress has been made in addressing runoff pollution, and in protecting aquatic habitats. Clean Water Act reauthorization should focus on pollution prevention to reduce further the release of toxics by point sources, a new program of mandatory but flexible controls on sources of runoff, and watershed protection programs to promote habitat protection and restoration. Economic factors should be considered in Clean Water Act programs, but must be balanced against scientific and governmental factors as well.  相似文献   

8.
ABSTRACT: A 155,947 ha portion of the Shenango River watershed in western Pennsylvania was evaluated as to the potential impact of agriculture drainage on water quality. Approximately a third of the area is being used as either cropland or pasture with approximately an equal percentage in forest lands. Eleven subwatersheds were evaluated as to their potential for nonpoint source pollution according to the criteria established by the Pennsylvania Department of Environmental Resources for the Chesapeake Bay Pollution Abatement Program. The individual components and overall rating for each subwatershed were then evaluated as to their correlation with four water quality variables based on 104 samples collected at 26 sampling stations throughout the watershed. There was a significant correlation between the overall rating factor for each subwatershed and each of the four water quality variables. In general, the watershed delivery factor, animal nutrient factor, and management factors were correlated with fecal coliform and phosphorus in the receiving streams, whereas the ground water delivery factor appeared to be more important in determining nitrate concentrations in these streams. These results indicate that manure and nutrient management, along with the exclusion of livestock from streams and the enhancement and/or replacement of riparian wetlands, are important approaches in reducing agricultural impacts in fresh water ecosystems.  相似文献   

9.
ABSTRACT: Recent regulations require impact statements for major water development projects, including reservoirs that will be used for water supply, recreation, and pollution control. A water quantity/quality model was developed and used for making water quality projections of a proposed reservoir in Montgomery County, Maryland. The study area is uncommon in that there is an extensive water quality data base. The results indicate that land use changes will have a significant effect on water quality and that the proposed reservoir will improve the quality of the surface waters downstream from the reservoir. A major effect of land use changes is the increase in the variability of water quality.  相似文献   

10.
ABSTRACT: The reauthorization of the Clean Water Act reemphasizes the need for regional scale monitoring and management of nonpoint pollution loads. The magnitude of the task will require that local governments and their consultants integrate information systems and modeling if they are to manage the massive data sets and conduct the array of simulations that will be needed to support the decision making processes. Interfacing geographic information systems (GIS) and nonpoint pollution modeling is a logical approach. The objective of the present study was to use the 37,000-acre area defined by the Kensington Quadrangle sheet in Montgomery County, Maryland, to show that GIS-supported nonpoint pollution modeling is practical and economically attractive. The purpose of the GIS is to estimate the spatial distribution of nonpoint nitrogen, phosphorous, zinc, lead, BOD, and sediment using a model developed by the Northern Virginia Planning District Commission. The system allows the user to change land uses in subareas to simulate the consequences of additional development or alternate management strategies. The tests show that in-house development of this type of special purpose GIS is a practical alternative to vendor supplied systems and that the required databases can be developed quite reasonably.  相似文献   

11.
ABSTRACT: Nonstorm water discharges to municipal separate storm sewer systems (MS4s) are notable for spatial and temporal variability in volume, pollutant type, pollutant concentration, and activity of origin. The objective of this paper was to determine whether current technical knowledge and existing U.S. policy support an improved regulatory approach. The proposed policy would use type of discharge as a regulatory basis, merging the concepts of allowability of de minimis discharges and type-based statewide consistent rules. Specific research objectives were to comprehensively identify discharge types, characterize their prevalence in California, analyze relevant local and regional regulatory guidelines, and systematically evaluate opinions of experts about potential water quality impacts. Results demonstrate nonstorm water discharges were widespread in at least one sector, industrial facilities subject to a state permit; one discharge for every four facilities was reported in 1995, even though the permit explicitly prohibits such discharges. Clear consensus exists for minimal water quality concern for some discharge types when considering both municipal guidelines and experts’ opinions. In particular, condensate from a wide range of equipment and discharges from fire fighting equipment testing were found to be of low concern. Discharge types with consensus high concern were largely limited to discharges prohibited under other regulations, such as wastewater and hazardous waste management controls. Some discharge types where no consensus was identified, such as landscape irrigation, nevertheless generated concern for water quality impacts and appear to be relatively widespread. Available information supports technical feasibility of the proposed policy because at least some discharge types show strong consensus for de minimis impacts among regulatory guidelines and opinions of technical experts.  相似文献   

12.
ABSTRACT: The computer model, CREAMS, has been developed for field-sized agricultural areas to aid in best management practices evaluation and planning. A test of CREAMS was performed by comparing monthly observed and simulated values for runoff, sediment, and phosphorus exports from two agricultural fields in Vermont to determine the applicability of the model in cold climates. Water quality samples were collected from field runoff and analyzed for both total suspended solids and total phosphorus. Generally, exports were overestimated during low flow months and underestimated during high flow months. Significant r2values (p <0.05), ranging from 0.78 to 0.90, between simulated and observed data were found for all comparisons except for sediment export from one field. Comparisons of the slopes of the regressions between observed and simulated values and the ideal slope of one using t-tests revealed significant differences between simulated and observed monthly runoff, sediment, and phosphorus exports. It is postulated that this lack of adequate prediction could be attributed to the use of average monthly, instead of daily, temperature and solar radiation in calculations of evapotranspiration and snowmelt, and the use of static parameter values for parameters that vary seasonally.  相似文献   

13.
ABSTRACT: Storm water detention basins have historically been employed for quantity (i.e., flooding) control only. However, recently it has been suggested that these basins may also provide a practical means of storm water quality control. This paper presents the formulation of a mathematical modeling approach which may be used by professionals to simultaneously design detention basins for the dual purpose of storm water quantity and quality control. Model simulations demonstrate that for a given basin, pollutant removal increases as storm frequency increases. The importance of particle size distribution and settling velocity for net pollutant removal is illustrated, The design procedure is demonstrated, and pollutant loading diagrams for estimating pollutant removal as a function of storm size are developed.  相似文献   

14.
    
ABSTRACT: Increasing specialization separates animal production from cropland, complicating manure management. To assist policy targeting efforts, we highlight areas where on-farm use of manure may be problematic. Matching confined animal production with land, on the farm- rather than at the county-level, gives our analysis an advantage over previous studies in avoiding aggregation problems. With manure-based water quality problems, data aggregated to the county level may fail to convey the heterogeneity of animal production across regions and animal types. Aggregation bias blurs the distinction between areas with specialized animal production and those that merely have numerous animals. We estimate bias from using county aggregates, show its distribution spatially and by animal sector, and link it to concentration. Ongoing vertical integration in agriculture likely alters in-county variability in facility scale and scope, and may influence decisions about which data we should gather and use.  相似文献   

15.
ABSTRACT: A stochastic programming framework is developed to evaluate the economic implications of reliability criteria and multiple effluent controls on nonpoint source pollution. An integrated watershed simulation model is used to generate probability distributions for agricultural effluents in surface and ground water resulting from agricultural practices. Results from the planning model indicate that reliability and multiple effluent constraints significantly increase the cost of nonpoint controls but the effects vary by control alternative. The analysis indicates that an evaluation of multiple water quality objectives can be an important planning tool for designing nonpoint source controls for innovative programs to promote cost-effective water quality regulation.  相似文献   

16.
ABSTRACT: Pollutants in urban storm water runoff, a significant and increasing fraction of pollutants in some waters of the U.S., originate from multiple activities. The industrial sector, one source category, is subject to federal and state-level storm water pollution prevention regulations, primarily General NPDES Permits that rely heavily on facility operators to identify themselves and develop appropriate site-specific pollutant controls. Degree of compliance is not readily determined and enforcement is inhibited because no publicly-available inventories contain data necessary to comprehensively identify facilities required to comply. This research evaluates the first stage of compliance, facility self-identification, concentrating on the motor-vehicle, transportation industry category using data at three scales: statewide, regional, and local or watershed. Data for California statewide and for the Los Angeles region show about 8 percent to 15 percent of motor-vehicle transportation facilities have complied with first-stage requirements. However, facility-specific evaluation in one Los Angeles County watershed suggests less than 50 percent of facilities in the industry conduct industrial activities of the kind covered by regulations; others need not comply. Results show strong variation by industry category. Second-stage compliance, follow-up reporting, is also evaluated for the Los Angeles region. About 17 percent to 34 percent of facilities completing first-stage requirements have also completed second-stage requirements.  相似文献   

17.
ABSTRACT. The Nation has entered a new era of water quality management in which land use policy and regulation must assume an increasingly important role. The benefits of tertiary and advanced waste treatment may be offset by contradictory land use and pollution from land runoff. Unless land use planning and controls are included in water quality management, land-imposed constraints on water quality can be anticipated. Pollution from major types of land runoff are reviewed with respect to sources, effects, and control procedures. Emphasis is given to land use practices and controls. The crucial issue with regard to the latter is lack of land use policies at federal, state, and local levels. State legislation establishing guidelines and minimum standards for land use regulation by local government is required. The dependency of water quality on land use points to the fallacy of attempting to provide for comprehensive water pollution control outside the context of comprehensive land-water resource planning and management.  相似文献   

18.
Abstract:  This research evaluated the effectiveness of regulations for stormwater pollutants originating from industrial facilities. Industrial facilities discharging stormwater are subject to General Permits implemented by state and federal agencies, which require facility operators to identify themselves and to implement pollution prevention measures. An overlying system of permits require Municipal Separate Storm Sewer System operators to identify and inspect facilities in their jurisdictions capable of discharging substantial pollutant loads into stormwater conveyances, introducing more active regulation and strategic prioritization, but with unequal implementation in different urban regions. This research evaluated the interaction between the regulations and ways in which the regulations succeed, or fail, at protecting water quality. The research evaluated potential for pollutant discharges at 136 industrial facilities in Pinellas County, Florida, using telephone interviews; off-site facility visits; and on-site facility inspections, targeting four industrial categories: wood products; stone, clay, glass, and concrete products; fabricated metal products; and electronic products. Results documented that a large proportion of facilities subject to General Permits conduct few or no activities likely to produce stormwater pollutants, indicating that the regulations’ equal treatment of all facilities may constitute overregulation. The research developed a methodology to assess facilities using intensity of industrial activities exposed to stormwater, a rational measurement that could regularize municipal agencies’ requirements and prioritize implementation toward facilities with the potential to impact receiving water quality.  相似文献   

19.
ABSTRACT: A framework for estimating the water quality benefits from soil erosion was developed. The framework is based on the linkages between soil erosion and offsite damages. The linkages are: erosion on the field, movement of eroded materials to waterways, impact of discharged material on water quality parameters, impact of water quality changes on ability of water to provide economic services, and the economic value of the changes in water use. These linkages need to be modeled in order to estimate the water quality benefits from reductions in soil erosion. Methods for modeling each link on a geographic level, which enables the analyses of national soil conservation, were examined. Areas where data or models were found to be lacking include transport of sediment and nutrients to water systems, impact of discharged materials on water quality parameters, and impact of water quality on ability of water to provide economic services. An economic evaluation of 1983 soil conservation programs was presented as an example of how the framework could be used. A number of simplifying assumptions were made to represent links that could not be modeled with available data.  相似文献   

20.
ABSTRACT: Contrary to the general trend of only a few actual trades occurring within point‐nonpoint source water quality trading programs in the United States, two trading projects in the Minnesota River Basin, created under the provisions of National Pollutant Discharge Elimination System (NPDES) permits, have generated five major trades and numerous smaller ones. In this paper, these two projects are described to illustrate their origins, implementation, and results. It was found that several factors contributed to the relatively high number of trades in these projects, including the offsetting nature of the projects (hence a fixed number of credits that the point sources were required to obtain), readily available information on potential nonpoint source trading partners, and an effectively internal trading scheme used by one of the two projects. It was also found that long term structural pollution control measures, such as streambank stabilization, offered substantial cost savings over point source controls. Estimates of transaction costs showed that the total costs of the trading projects were increased by at least 35 percent after transaction costs were taken into account. Evidence also showed that in addition to pollution reduction, these two trading projects brought other benefits to the watershed, such as helping balance environmental protection and regional economic growth.  相似文献   

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