Showing papers on "Nonpoint source pollution published in 1989"

AGNPS: A nonpoint-source pollution model for evaluating agricultural watersheds

Abstract: A computer model to analyze nonprofit-source pollution and to prioritize potential water quality problems in rural areas is described. The event-based model uses geographic cells of data units at resolutions of 0.4 to 16 ha to represent upland and channel conditions. Within the framework of the cells, runoff characteristics and transport processes of sediment, nutrients, and chemical oxygen demand are simulated for each cell and routed to the outlet. This permits the flow at any point in the watershed to be examined. Upland sources contributing to a potential problem can be identified and prioritized where remedial measures could be initiated to improve water quality most efficiently.

Optimal Spatial Management of Agricultural Pollution

Abstract: Through forces of wind and water, agricultural chemicals and soil particles move to and contaminate water bodies. Possibilities for containing these pollutants have gone largely unnoticed by economists, who have focused on reducing discharges. Many soil and water management measures not only prevent pollutants from becoming dislodged but also intercept surface runoff. This paper demonstrates the importance of managing the movement of agricultural pollutants, specifically sediment. Abatement costs can be reduced and more ambitious abatement objectives justified when pollutants are contained. However, containment requires coordinated action by landowners. Achieving this coordination is a major challenge for pollution control programs.

Delivery of sediment and pollutants from nonpoint sources: A water quality perspective

Abstract: In a 1984 report to Congress, the U.S. Environmental Protection Agency (EPA) concluded that nonpoint pollution was a leading cause of the nation's remaining water quality problems. Half of the states specified that nonpoint pollution was a significant water quality problem, and nearly every state reported some kind of water quality problem related to these sources. Research suggested that lakes, including the Great Lakes; reservoirs; and estuaries, such as the Chesapeake Bay, were particularly vulnerable to nonpoint pollution. Recognizing the need for a massive, federal nonpoint pollution cleanup program, the EPA administrator called for redirecting existing federal, state, local, and private resources to assess nonpoint source problems of national significance ( 45 ). Managers of nonpoint pollution abatement programs must identify land and define those land use activities that pose the most severe threat to receiving waters, so-called “hazardous land” (34). To define hazardous lands, information is needed on the strength of the pollution source and on attenuation of pollutants between the source and receiving water body. Sediment delivery characteristics In the 1950s, researchers studying sediment deposition in reservoirs noted that the quantity of sediment deposited in and passed through reservoirs was smaller than the upland erosion potential …

Targeting the Conservation Reserve Program to Maximize Water Quality Benefits

Abstract: There is a growing desire on the part of environmental and conservation groups to see agricultural programs that remove cropland from production, or that require soil and input conservation, be used to protect or improve water quality. Such programs could become powerful tools for addressing an important source of water pollution. One such program is the Conservation Reserve Program (CRP). Many environmental groups are looking upon the CRP as a way of retiring from production cropland which is contributing to water quality problems. Senators Robert Dole and Wyche Fowler have each proposed expansions of the CRP specifically to address water quality issues. The Environmental Protection Agency is encouraging states either to incorporate the CRP into their plans to meet the nonpoint source pollution requirements of the 1987 Water Quality Act, or to develop their own CRP-like programs. Most discussions of how to approach the problem of nonpoint source pollution involve targeting programs to problem watersheds. For example, Section 319 of the 1987 Water Quality Act requires states to identify priority watersheds for treatment of nonpoint source pollution problems. Such targeting implies there exist criteria upon which areas can be ranked for the purpose of implementing water quality improvement measures. The criteria selected are

Surface Water Pollution and Its Control

Abstract: Parameters of surface water quality and their interpretation introduction to microbiology - sewage fungus biology of surface waters quality of natural waters de-oxygenation, self-purification and re-aeration water and disease - survival of pathogenic organisms in sewage effluents - bacterial indicators of faecal pollution oil-pollution temperature effects and thermal pollution eutrophication acid precipitation and its effect on surface water storm sewage discharges and urban surface run-off legislation the operation of a surface water pollution control organization river quality modelling, A.E.Warn (Anglian Water Authority, Huntingdon).

Input Management of Production Systems

Abstract: Nonpoint sources of pollution, which are largely responsible for stressing regional and global life-supporting atmosphere, soil, and water, can only be reduced (and ultimately controlled) by input management that involves increasing the efficiency of production systems and reducing the inputs of environmentally damaging materials. Input management requires a major change, an about-face, in the approach to management of agriculture, power plants, and industries because the focus is on waste reduction and recycling rather than on waste disposal. For large-scale ecosystem-level situations a top-down hierarchical approach is suggested and illustrated by recent research in agroecology and landscape ecology.

Preliminary evaluations of regional ground-water quality in relation to land use

Abstract: The U.S. Geological Survey through its Toxic-Waste— Ground-Water Contamination Program began studies during 1984 to evaluate the degradation of regional ground-water quality as a result of human activities. The studies are designed to quantitatively relate human activities, expressed as land use, to the quality of ground water at a regional scale. Preliminary results from six of the studies in New York, New Jersey, Connecticut, Florida, Nebraska, and Colorado summarized in this paper indicate that regional ground-water quality has been affected by human activities. The frequencies of detection of volatile organic compounds and some trace elements were larger in ground water underlying urban or industrial areas in comparison to undeveloped areas. Ground water in agricultural areas generally had larger concentrations of nitrate and had an increased frequency of detection of pesticides in comparison to undeveloped areas. Effects of human activities on water quality increased as the intensity of urbanization or irrigation increased. Ground-water pumpage, waste-water discharges into a stream that is hydraulically connected to an alluvial aquifer, and consumptive use of ground water affected the ground-water quality in one study area to a greater extent than land-use practices. These preliminary results indicate that in specific areas, surficial nonpoint sources, expressed as land use, have altered regional ground-water quality. Additional studies are being made to determine if these results are consistent and widespread.

Water quality achievable with agricultural best management practices

Abstract: Greater emphasis has been placed on controlling nonpoint sources of pollution; however, the quality of water achieved by implementing best management practices (BMPs) remains uncertain. Water quality in runoff from agricultural areas under best management was compared with water quality standards, where appropriate, and with other measures of treated water, thereby defining the water quality achievable by using best management practices. The study draws upon results obtained from 7 years of water quality monitoring in the LaPlatte River and St. Albans Bay watersheds in Vermont of BMPs implemented for manure management, barnyard runoff, and milkhouse wastes. These studies include long-term stream monitoring for sediment and nutrient concentration and load, as well as intensive evaluation of the treatment effectiveness of certain BMPs, such as vegetated filter strips and manure storage, on concentration and export of sediment, nutrients, and bacteria. Results indicate that BMPs may be highly effective in reducing pollutant concentrations and loads, but runoff may continue to exceed water quality criteria. Further development of BMPs is needed to improve the water quality achievable.

Impact of land use and nps loads on lake quality

Abstract: Extensive land use, nonpoint source (NPS), and lake water quality data are used to determine the interaction of lake water quality and watershed development in the Lake Austin watershed. Historical trends in total suspended solids and total phosphorus are examined over the 1979–84 period, during which impervious cover increased by 79% in the lake watershed. A PC‐based continuous stirred tank reactor (CSTR) model is used to depict the response of lake water quality to loadings associated with a variety of development options ranging from impervious cover of 10–40%. The reliability of the model is supported by the unusually simple lake hydraulics, exclusive NPS loading, and extensive data base. Model results are used to create a set of recommendations that should protect the water quality of the lake.

Evaluation of North Carolina's estuarine shoreline area of environmental concern from a water quality perspective

Abstract: Nonpoint source pollution from estuarine shoreline development is a major water quality issue in North Carolina. The state's Coastal Area Management Act includes an “estuarine shoreline Area of Environmental Concern”; (AEC) where land‐disturbing activities are subject to permitting. The estuarine shoreline AEC extends inland 75 feet (23 m) from the mean high water mark, providing an incentive to maintain vegetated buffers (to avoid permit requirements) and giving the state some control over nearshore activities. But is this 23‐meter buffer sufficiently wide for protecting water quality? A hydrologic model that measures the ability of a buffer zone to detain polluted stormwater is applied in the state's Carteret County. Results show that for typical residential and commercial development, 23 m provides an inadequate width for filtering polluted runoff. This suggests that the dimensions of the estuarine shoreline AEC should be expanded if it is to be an effective tool for protecting estuarine water...

Estimating the water quality benefits from soil erosion control1

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.

Characterisation of unresolved complex mixtures of hydrocarbons

Abstract: Metadata merged with duplicate record (http://hdl.handle.net/10026.1/666) on 20.12.2016 by CS (TIS).

Spreadsheet watershed modeling for nonpoint-source pollution management in a Wisconsin basin

Abstract: Although several sophisticated nonpoint pollution models exist, few are available that are easy to use, cover a variety of conditions, and integrate a wide range of information to allow managers and planners to assess different control strategies. Here, a straightforward pollutant input accounting approach is presented in the form of an existing model (WATERSHED) that has been adapted to run on modern electronic spreadsheets. As an application, WATERSHED is used to assess options to improve the quality of highly eutrophic Delavan Lake in Wisconsin. WATERSHED is flexible in that several techniques, such as the Universal Soil Loss Equation or unit-area loadings, can be used to estimate nonpoint-source inputs. Once the model parameters are determined (and calibrated, if possible), the spreadsheet features can be used to conduct a sensitivity analysis of management options. In the case of Delavan Lake, it was concluded that, although some nonpoint controls were cost-effective, the overall reduction in phosphorus would be insufficient to measurably improve water quality.

Effects of animal waste control practices on nonpoint-source phosphorus loading in the west branch of the Delaware River watershed

Abstract: The water quality objective of the New York State Model Implementation Program (MIP) was to reduce phosphorus (P) loading to the Cannonsville Reservoir, a eutrophic impoundment on the West Branch of the Delaware River that supplies drinking water to New York City. The MIP focused on controlling P losses from animal waste sources in the rural watershed, particularly dairy barnyards. Results indicated that runoff from the West Branch watershed during the winter-spring period accounted for more than 80% of the annual loading of dissolved and total P to the reservoir. Reductions in barnyard P losses of 50% to 90% were shown to be achievable using practices that reduced the volume of runoff from these areas. However, the contribution of P from barnyard runoff was substantially less than that from manure-spread cropland in the budget for annual losses of dissolved and total P in the West Branch watershed. Manure spreading schedules that guide the location and timing of spreading had the potential to reduce P loading from the studied subwatershed by as much as 35% in the absence of short-term or long-term manure storage systems. Because treatment of cropland was given only limited attention by the MIP, P loading reduction attributable to the program as well as the response of the reservoir9s water quality were negligible.

Soil erosion and nonpoint-source pollution control in an Idaho watershed

Abstract: A geographic information system was used to assemble and retrieve the physical parameters required to estimate sheet and rill erosion and water quality effects of applying II resource management systems to 16 farms in Idaho9s Tom Beall watershed. A linear programming model was used to determine the economically efficient (optimal) systems for reducing total erosion and nonpoint-source pollution in the watershed. The water quality effects of the optimal resource management systems were evaluated using the Agricultural Nonpoint Source (AGNPS) model. Minimum tillage with either cross-slope farming or contour farming was the most economically efficient system for reducing farm-level erosion rates. All but two farms had to switch from conventional to minimum tillage to reduce the average erosion rate in the watershed to the tolerance (T) level [11.2 t/ha/yr (5 tons/acre /year)]. Reducing average erosion to 2T required using no tillage practices on II farms and converting two farms to permanent vegetation. Total net farm income in the watershed increased 1.5% when average erosion was reduced to T. Controlling erosion significantly reduced total sediment, nutrients (nitrogen and phosphorus), and chemical oxygen demand (COD). Average sediment, nutrients, and COD decreased 45%, 38%, and 24%, respectively, with the optimal resource management systems for 2T, and 72%, 64%, and 29%, respectively, with the optimal systems for T.

Effect of Buffer Zones on Estuarine and Riparian Land Use in Eastern North Carolina

Abstract: INTRODUCTION. Stormwater-borne (nonpoint source) pollution from urban and agricultural runoff is a critical water quality problem in the North Carolina Coastal Plain. Nutrient and sediment pollution of rivers and estuaries is largely attributed to farm runoff, while bacterial contamination of shellfish beds and recreational waters and accumulations of metals and toxics in coastal waters have been linked to urban, residential, and recreational development along North Carolina's estuarine shorelines. (J) A key management technique for dealing with these runoff-borne pollutants is the maintenance of vegetated riparian buffer zones. These buffers provide filters to cleanse contaminated runoffbefore it can enter surface waters, delay stormwater so that contaminants may decompose or settle out, and simply move development farther from the shore, which reduces pollutant delivery. In the case of agricultural nonpoint source (NPS) pollution, riparian buffers are generally in the form ofbottomland forests along stream corridors. Where the concern is stormwater from urban and commercial shoreline development, the buffer is typically a vegetated (usually with grass) setback from the water line. Establishment and maintenance of an undeveloped vegetated area along stream banks and estuary shores have significant potential landuse implications. In the case of coastal shorelines, there are clear economic impacts because of strong development pressures, intense landuse competition, and the extremely high value of waterfront property. These variables are usually not important along inland stream corridors in Eastern North Carolina, but restrictions on rural and agricultural land use are even more controversial than in residential and commercial areas. (2) * Information provided by Lynn Phillips (Director, Carteret County Planning Department) was helpful in interpreting the land-use implications of the buffer model. Leo Zonn provided useful comments on an earlier draft. Dr. Phillips is Associate Professor ofGeography and Planning at East Carolina University in Greenville, NC 27858.

Economic targeting of nonpoint pollution abatement for fish habitat protection

Abstract: A model is presented which relates farm economics, pollutant delivery, fisheries habitat quality and reliability, and spatial optimization. The model identifies the most profitable cropping practices which provide an acceptable level of risk of impairment to the physical and chemical fish habitat. The potential of the model as a watershed management aid is demonstrated with an application to salmonid habitat in a Lake Michigan tributary.

Nonpoint source pollution risk assessment in a watershed context

Abstract: Nonpoint source pollution control requires assessment of the influence of dispersed runoff-contributing areas on downstream water quality. This evaluation must consider two separate phases: site-to-stream loading and downstream fluvial transport. Any model, combination of models, or procedure for making this assessment can be generalized to a simple spatial model or framework, which considers runoff or pollutant loading per unit area and down-stream attenuation, with drainage area as a scaling factor. This spatial model has a probabilistic interpretation and can be used in conjunction with a standard dilution model to give a probabilistic estimate of the impacts at the basin mouth of runoff from a specific upstream contributing area. It is illustrated by applying it to an assessment of the probability that various copper concentrations at the mouth of the urbanized South Platte River basin in Denver, Colorado, USA, will be exceeded as a result of runoff from a subbasin within the city. Determining the probability that a concentration of a pollutant at the basin mouth can be attributed to runoff from a discrete area within the basin is useful for targeting and risk assessment because it enables quantitative risk-based comparisons. The spatial framework is also useful for evaluating management and control options, since actions within the basin can be directly linked to water quality at a downstream point.

Bacteriological Water Quality in Vermont Agricultural Watersheds Undergoing Land Treatment

Abstract: Bacteria are often important indicators of nonpoint source water pollution. Runoff from farmland and agricultural activities such as animal waste management, feedlots, and grazing are the principal sources of bacteria to surface waters. Fecal coliform and fecal streptococcus levels have been monitored in four Vermont agricultural watersheds for eight years as part of the LaPlatte River Watershed Project. This project is a long-term monitoring program designed to evaluate the effects of implementing best management practices on water quality. Bacterial densities recorded in the monitored streams and in runoff from specific agricultural practices are reported. While levels of fecal streptococci in the streams have declined significantly since implementing land treatments, bacterial densities continue to exceed water quality criteria 20 to 30 percent of the time, particularly in summer. Bacterial densities in the streams appear related to agricultural activities within their watersheds such as corn ...

Farm Income and Ground Water Quality Implications from Reducing Surface Water Sediment Delweries

Abstract: The potential surface water and ground water quality tradeoff implications from the nonpoint source provisions of the 1987 Water Quality Act are investigated in this paper using a national linear programming model developed at Iowa State University and modified by the Economic Research Service and the Leaching Evaluation of Agricultural Chemicals (LEACH) Handbook developed by the U.S. Environmental Protection Agency. The linear programming model is used to maximize net farm revenue using optimal combinations of crop rotations and tillage practices for each region of the United States given natural resource constraints. The LEACH handbook is used to determine the relative potential for pesticides to leach below the root zone for different soil types, hydrologic conditions, pesticides used, and tillage practices. The results indicate that imposing a surface water quality erosion constraint aimed at reducing sediment concentrations results in a larger decrease in farm income than imposing a uniform 5 ton per acre per year erosion constraint. Both constraints could result in regional improvement in ground water quality in some regions of the country while decreasing ground water quality in other regions.