Showing papers on "Water quality published in 1988"

WASP4, a hydrodynamic and water-quality model - model theory, user's manual, and programmer's guide

Abstract: The Water Quality Analysis Simulation Program Version 4 (WASP4) is a dynamic compartment-modeling system that can be used to analyze a variety of water-quality problems in a diverse set of water bodies. WASP4 simulates the transport and transformation of conventional and toxic pollutants in the water column and benthos of ponds, streams, lakes, reservoirs, rivers, estuaries, and coastal waters. The WASP4 modeling system covers four major subjects--hydrodynamics, conservative mass transport, eutrophication-dissolved oxygen kinetics, and toxic chemical-sediment dynamics. The WASP4 modeling system consists of two stand-alone computer programs, DYNHYD4 and WASP4, that can be run in conjunction or separately. The hydrodynamic program, DYNHYD4, simulates the movement of water and the water quality program, WASP4, simulates the movement and interaction of pollutants within the water. The latter program is supplied with two kinetic submodels to simulate two of the major classes of water-quality problems--conventional pollution (dissolved oxygen, biochemical oxygen demand, nutrients, and eutrophication) and toxic pollution (organic chemicals, heavy metals, and sediment). The substitution of either sub-model constitutes the models EUTRO4 and TOXI4, respectively.

Water Pollution Biology

Abstract: Water pollution problems and solutions sources and effects of water pollutants biological monitoring of water quality the toxicity of pollutants to aquatic organisms water pollution and public health water pollution control estuarine and marinepollution.

Concepts for a National Water-Quality Assessment Program

Abstract: A proposed National Water-Quality Assessment Program, described in this report, would contribute to the Nation's need for better information on the status, trends, and causes of water-quality conditions across the Nation. The assessments would be conducted through an aggregation of individual studies of key river basins and aquifer systems to provide water-quality information that is useful in understanding and managing these important water resources, as well as answering national questions about water quality.

Influence of Overwatering and Fertilization on Nitrogen Losses from Home Lawns

Abstract: Fertilized home lawns represent a potential source of NO,-N contamination to groundwater and surface waters. The waterborne losses of inorganic N from Kentucky bluegrass (Poa pratensis L.) turf subjected to three levels of N fertilization (0, 97, and 244 kg N ha"' yr~' as urea and methylene urea) and two irrigation regimes (scheduled by tensiometer and overwatering with 3.75 cm of water per week in addition to rainfall) were measured. The site was located on a Merrimac sandy loam (sandy, mixed, mesic Typic Dystrochrept). Soil-water percolate was collected by suction plate lysimeters placed below the root zone. Surface runoff was quantified with orifice flow splitters. Soilwater percolate flux comprised >93% of the total water and inorganic-N discharged from all treatments. Mean annual flow weighted concentrations of inorganic N in soil-water percolate were below the U.S. drinking water standard on all treatments and ranged from 0.36 mg L' on the overwatered, unfertilized, control treatment to 4.02 mg L" on the over-watered, high N treatment. Annual losses ranged from 32 kg ha"' on the overwatered high N rate treatment to 2 kg ha' on the scheduled irrigation, unfertilized, control treatment. Overwatering in conjunction with fertilization generated significantly higher annual flow weighted concentrations and mass loss than the unfertilized controls. Nitrogen loss and concentrations from the scheduled irrigation treatments were not significantly different from the controls. Additional Index Words: Nitrate-nitrogen, Turfgrass, Groundwater pollution, Water quality, Irrigation scheduling. Since 1970, pesticide and fertilizer use on home lawns has steadily increased (Watschke, 1983). The growth of chemical use suggests the possibility for an increase in off-site losses and subsequent environmental contamination. Lawn care chemicals may be applied in close proximity to impervious zones with high potential for surface runoff. Miller et al. (1974), in their study of groundwater contamination in the northeastern USA, stressed the need for long-term studies to determine if home lawn agrichemicals have penetrated the soil zone and entered the groundwater system. Several researchers have described conditions under which they found substantial NO3-N leaching from fertilized cool season turf grass (Owen and Barraclough, 1983; Rieke and Ellis, 1974). Nitrate-N is a drinking water contaminant with a U.S. drinking water standard of 10 mg L" (USEPA, 1976). Leaching of NO3 is of particular T.G. Morton and A. J. Gold, Dep. of Natural Resources Sciences, and W.M. Sullivan, Dep. of Plant Sciences, Univ. of Rhode Island, Kingston, RI 02881-0804. Contribution from the Rhode Island Agric. Exp. Stn. as Journal Paper no. 2380. Received 2 Mar. 1987. "Corresponding author. Published in J. Environ. Qual. 17:124-130 (1988). 124 J. Environ. Qual., Vol. 17, no. 1, 1988 concern on Long Island, NY, and the southern New England states where permeable, outwash soils overlie unconfined drinking water aquifers. Coastal estuaries and bays have been found to be N limited, and may be degraded by concentrations of NO3-N much less than the drinking water standard of 10 mg L-~ (Ryther and Dunstan, 1971). Other researchers have shown little increase in NOrN leaching from fertilized turfgrass (Starr and DeRoo, 1981; Snyder et al., 1984). Starr and DeRoo (1981) monitored the fate of N applied to cool season turfgrasses in southern New England and found low concentrations of NOrN in leachate when moderate rates of N were applied and no supplemental irrigation water was used. Irrigation has been shown to significantly increase NOrN leaching (Snyder et al., 1984; Endelman et al., 1974; Timmons and Dylla, 1981; Rieke and Ellis, 1974). Home lawns are typically watered with little regard for soil moisture status or the water holding capacity of the soil. Where irrigation is automatically controlled, rates are often selected to meet maximum evaporative demands, resulting in routine overwatering (Snyder et al., 1984). Excessive watering will increase antecedent soil moisture, thereby promoting additional leaching and surface water runoff from natural storm events or from the supplemental water alone. The goal of this study was to quantify N losses from turf subjected to the range of fertilization and watering practices generally used on home lawns. Commercial applicators often employ several practices that past studies have shown to minimize off-site transport of N (Rieke and Ellis, 1974; Brown et al., 1982). Nitrogen is frequently applied in the form of urea in combination with some form of slow release materials, rather than in immediately available forms. The fertilizer is usually applied in small increments throughout the growing season, which is thought to minimize high N concentrations in the root zone. However, commercial home lawn care companies often apply greater annual amounts of N than individual homeowners. A survey of 460 households on Long Island found that homeowners applied an average of 122 kg N ha-’ yr-’ to their lawns (Koppelman, 1978). Many commercial operations apply 220 to 293 kg N ha-’ yr"~ (J.F. Wilkinson, Old Fox Lawn Care, Inc., 1985, personal communication). The objective of this study was to determine the effects of varying N fertilization rates and irrigation regimes on waterborne losses of inorganic N from home lawns. MATERIALS AND METHODS

Impacts of freshwater wetlands on water quality: a landscape perspective

Abstract: In this article, we suggest that a landscape approach might be useful in evaluating the effects of cumulative impacts on freshwater wetlands. The reason for using this approach is that most watersheds contain more than one wetland, and effects on water quality depend on the types of wetlands and their position in the landscape. Riparian areas that border uplands appear to be important sites for nitrogen processing and retention of large sediment particles. Fine particles associated with high concentrations of phosphorus are retained in downstream wetlands, where flow rates are slowed and where the surface water passes through plant litter. Riverine systems also may play an important role in processing nutrients, primarily during flooding events. Lacustrine wetlands appear to have the least impact on water quality, due to the small ratio of vegetated surface to open water. Examples are given of changes that occurred when the hydrology of a Maryland floodplain was altered.

Water analysis : a practical guide to physico-chemical, chemical and microbiological water examination and quality assurance

Abstract: In the growing concern for our environment, maintaining water quality standards and protecting natural water resources have assumed key significance, particularly in newly industrialising countries and Third World conurbations. Excessive strains on the environment, such as intensive farming, industry and centres of high population density, rapidly inflict serious damage both on the ecological balance and on human beings. This publication provides those engaged in monitoring and environmental laboratories, waterworks laboratories and also in research and teaching with reliable and recognized techniques of day-to-day analysis and assessment, in order to develop sound monitoring systems and effective measures for protecting and improving water quality. In addition to detailed instructions on sampling methods and on-the-spot analysis of water this guide provides a concise theoretical presentation of the various techniques of water analysis together with an indication of their relative importance, and describes methods for use in water analysis laboratories with simple equipment or the latest in modern facilities. It includes an account not only of up-to-date analysis methods, eg. tests for anthropogenic traces of organic and inorganic substances, but also biological approaches to water analysis. And finally it comments on the mathematical evaluation and weighting of the data obtained from water analysis, and makes it possible to arrive at a comparative appraisal of the findings in the light of new guidelines and rules on the quality of wastewater, surface water, ground water, drinking water etc. With 178 figs., 55 tabs..

Surface Water Supplies and Health

Abstract: Rivers, streams, lakes, and reservoirs have long been important sources of drinking water. In the past, these sources were often heavily contaminated by sewage discharges and, unfortunately, were also important in the transmission of communicable diseases such as typhoid and cholera. With improvements in sewage disposal practices, development and protection of water sources, and water treatment, outbreaks of waterborne disease are less frequently reported, and drinking water becomes a less important route of transmission of communicable disease. In the United States, the incidence of waterborne disease is low but waterborne outbreaks continue to occur. Outbreak statistics are reported in this article, and information is presented on the causes of these outbreaks, especially in surface water systems.

Cumulative impacts on water quality functions of wetlands

Abstract: The total effect of cumulative impacts on the water quality functions of wetlands cannot be predicted from the sum of the effects each individual impact would have by itself. The wetland is not a simple filter; it embodies chemical, physical, and biotic processes that can detain, transform, release, or produce a wide variety of substances. Because wetland water quality functions result from the operation of many individual, distinct, and quite dissimilar mechanisms, it is necessary to consider the nature of each individual process. Sound knowledge of the various wetland processes is needed to make guided judgements about the probable effects of a given suite of impacts. Consideration of these processes suggests that many common wetland alterations probably do entail cumulative impact. In addition to traditional assessment methods, the wetland manager may need to obtain appropriate field measurements of water quality-related parameters at specific sites; such data can aid in predicting the effects of cumulative impact or assessing the results of past wetland management.

A summary of the U.S. Geological Survey National Water-Quality Assessment program

Abstract: Beginning in 1986, the Congress appropriated funds for the US Geological Survey to test and refine concepts for a National Water Quality Assessment Program. At present, the program is in a pilot phase with field studies occurring in seven areas around the Nation. In 1990, a committee of the National Academy of Sciences will complete an evaluation of the design and potential utility of the program. A decision about moving to full-scale implementation will be made upon completion of the evaluation. The program is intended to address a wide range of national water quality issues that include chemical contamination, acidification, eutrophication, salinity, sedimentation, and sanitary quality. The goals of the program are to: (1) provide nationally consistent descriptions of current water quality conditions for a large part of the Nation's water resources; (2) define long-term trends in water quality; and (3) identify and describe the relations of both current conditions and trends in water quality to natural and human factors. This information will be provided to water managers, policy makers, and the public to provide an improved scientific basis for evaluating the effectiveness of water quality management programs and for predicting the likely effects of contemplated changes in land- andmore » water-management practices.« less

Potential Links Between Eutrophication and the Formation of Carcinogens in Drinking Water

Abstract: Eutrophication in lakes and reservoirs is a recreational problem and a drinking water quality problem. A major concern is trihalomethane (THM) formation from the reaction of chlorine, a disinfectant, with organic matter in natural water during drinking water treatment. Trihalomethanes, such as chloroform, are known or suspected carcinogens. Algae and allochthonous humic substances are known contributors to the THM precursor pool. Other in-reservoir precursor sources, macrophytes, and sediments, have not been investigated. The authors examined precursor generation in an Ohio water supply reservoir. A three-year input-output study demonstrated that 30 percent of the precursors entering the treatment plant were generated within the reservoir. Laboratory experiments revealed that macrophytes and sediments produce THM precursors. Estimated THM precursor contributions to the reservoir from macrophyte growth and sediment release were small, but algal productivity and macrophyte decomposition may contrib...

Application of Two‐Dimensional Water Quality Model

Abstract: A two‐dimensional, laterally averaged, finite‐difference hydrodynamic and transport water quality model was applied to DeGray Lake, Arkansas, a reservoir extensively studied by the U.S. Army Corps of Engineers. The reservoir was known to exhibit strong longitudinal and vertical gradients in water quality, while lateral variations were generally small. DeGray Lake exhibited dissolved oxygen declines in the metalimnion of the main pool and hypolimnion of headwater regions during summer and fall months. Field data from two separate years were used to calibrate and verify the model. Spatial and temporal variations in dissolved oxygen concentrations and other water quality variables were successfully predicted throughout the stratification cycles.

Bacteriological contamination of water in rural areas: an intervention study from Malawi.

Abstract: The bacteriological quality of drinking water sources and of stored household water was examined in a rural area of Malawi, before and after improvement of the method of water supply. Among the traditional water sources, water quality was better in springs than in wells and rivers. During the rainy season, there was a considerable deterioration of water quality, which was most pronounced in wells. The improved water supply system consisted of piped, untreated surface water from an uninhabited mountain area. This water contained a mean value of 54 faecal coliforms per 100 ml which can be regarded as acceptable in this setting. During collection of drinking water and during household storage, there was considerable contamination, which mirrored the unhygienic environment. Contamination was worse during the rainy season than during the dry season. Technical interventions aimed at improving water supply in rural areas of developing countries will probably not become effective unless combined with comprehensive health education programmes for the population concerned.

Nationwide regression models for predicting urban runoff water quality at unmonitored sites

Abstract: Regression models are presented that can be used to estimate mean loads for chemical oxygen demand, suspended solids, dissolved solids, total nitrogen, total ammonia plus nitrogen, total phosphorous, dissolved phosphorous, total copper, total lead, and total zinc at unmonitored sites in urban areas. Explanatory variables include drainage area, imperviousness of drainage basin to infiltration, mean annual rainfall, a land-use indicator variable, and mean minimum January temperature. Model parameters are estimated by a generalized-least-squares regression method that accounts for cross correlation and differences in reliability of sample estimates between sites. The regression models account for 20 to 65 percent of the total variation in observed loads.

Strategies for assessing the cumulative effects of wetland alteration on water quality

Abstract: Assessment of cumulative impacts on wetlands can benefit by recognizing three fundamental wetland categories: basin, riverine, and fringe. The geomorphological settings of these categories have relevance for water quality.

Eutrophication of lakes and reservoirs: A framework for making management decisions

Abstract: The development of management strategies for the protection of environmental quality usually involves consideration both of technical and nontechnical issues. A logical, step-by-step framework for development of such strategies is provided. Its application to the control of cultural eutrophication of lakes and reservoirs illustrates its potential usefulness. From the perspective of the policymaker, the main consideration is that the eutrophication-related water quality of a lake or reservoir can be managed for given water uses. The approach presented here allows the rational assessment of relevant water-quality parameters and establishment of water-quality goals, consideration of social and other nontechnical issues, the possibilities of public involvement in the decision-making process, and a reasonable economic analysis within a management framework.

Water quality after logging small watersheds within the bull run watershed, oregon

Abstract: Road building, clearcutting 25 percent of the watershed, and slash disposal by broadcast burning or by natural decomposition caused changes in water quality of two small streams in the Bull Run Watershed in Oregon, which supplies water to the Portland, Oregon, metropolitan area. Concentrations of suspended sediment increased slightly, primarily owing to construction of a permanent logging road that crossed streams. Changes in nutrient cycling occurred due to logging and slash disposal in both watersheds where cutting was done. NO3-N concentrations, which increased most where logging residue was left to decompose naturally, increased more than sixfold and commonly exceeded 100 pg/i during the October-June high-flow season for seven years after logging. Where logging slash was broadcast burned, NO3-N concentrations increased roughly fourfold, but rarely exceeded 50 μg/l, and increases had mostly disappeared six years after slash burning. Changes in outflows of cations and other anions were not apparent. Annual maximum stream temperatures increased 2–3°C after logging, but temperature increases had mostly disappeared within three years as vegetation regrowth shaded the streams.

Contaminant Propagation in Distribution Systems

Abstract: The Safe Drinking Water Act (SDWA) of 1974 requires that the U.S. Environmental Protection Agency (EPA) establish maximum contaminant levels (MCLs) for each contaminant which may have an adverse effect on the health of persons. The SDWA clearly specifies that these MCLs shall be met at the consumers tap. Nevertheless most regulatory concern has been focused on water as it leaves the treatment plant before entering the distribution system. There is, however, growing interest in determining the factors that cause water quality variations in drinking water distribution systems. In order to study this effect, the Drinking Water Research Division of EPA initiated a cooperative agreement with the North Penn Water Authority. This cooperative agreement has resulted in a series of field monitoring and systems modeling studies that lend insight into the movement of contaminants in distribution systems. Previous research has resulted in development of a steady-state model, a quasi-steady-state model and dynamic model that have provided useful approaches to modeling the general propagation of contaminants in distribution systems. In this paper, results from the steady-state model are utilized to examine the actual pathways of water flow and the time of passage and percentage of water that flows from a given source to a given node in a distribution system. The contaminant propagation technique developed from this extension of the steady-state model provides a useful technique for analyzing many of the factors that affect water quality in a distribution system. A major finding of this research study is the importance of adequate hydraulic modeling of the systems being studied and the importance of field studies in verifying systems performance. The approach suggested in this research will provide useful insight into the water quality variations that may impact consumers at the tap and the development of time and spatially sensitive monitoring strategies.

Monitoring Dissolved Oxygen in Ground Water: Some Basic Considerations

Abstract: Dissolved oxygen (D.O.) concentration has a significant effect upon ground water quality by regulating the valence state of trace metals and by constraining the bacterial metabolism of dissolved organic species. For these reasons, the measurement of dissolved oxygen concentration should be considered essential in most water quality investigations. D.O. measurements have been frequently neglected in ground water monitoring. This is because O2 has often been assumed absent below the water table; measurement of O2, concentrations is not mandated by drinking water standards; and the redox potential has previously been considered an adequate and encompassing electrochemical measurement. Redox potentials, however, cannot adequately predict dissolved oxygen concentrations nor can D.O. concentrations be used to calculate redox potentials. D.O. concentrations can be measured precisely in the field by titration or electrode methods. The best methods of sample recovery are those that use positive pressure displacement devices. A fully adequate sampling procedure will isolate ground water from the atmosphere and will collect samples at restricted depth intervals at ambient temperature and pressure.

The Historical Context of Water Quality Management for the Delaware Estuary

Abstract: The Delaware Estuary, bounded by the states of Delaware, New Jersey and Pennsylvania, is located in one of the most complex urban-industrial regions in the United States. Water pollution of the estuary was observable over two centuries ago and progressively worsened until after World War II. Four distinct governmental responses to the pollution have led to the vastly improved water quality of today. A fifth-generation response, now being initiated, is oriented toward remaining problems, including toxic contamination of the water column, bottom materials and aquatic life. Changes in water quality and the institutional responses to pollution are traced to demonstrate the evolutionary process of water pollution control.

The effects of heavy metals pollution of the upper Arkansas River on the distribution of aquatic macroinvertebrates

Abstract: Water quality, types, and diversity of aquatic macroinvertebrates show that heavy metal pollution of the upper Arkansas River is presently moderately severe and conditions for aquatic life are generally poor, particularly in the Leadville area. A 2 year study was done on a 30 km section of the upper Arkansas River, Colorado, to determine the effects of heavy metals pollution on the distribution of the aquatic macroinvertebrates. Physical and chemical water parameters were measured, and aquatic macroinvertebrates were collected. The major sources of heavy metal-laden inflows are Leadville Drain, California Gulch, and a number of intermittent flows entering the Arkansas River between Lake Fork and Lake Creek. Important freshening flows are Tennessee Creek, Lake Fork (containing Halfmoon Creek), and Lake Creek.

Agriculture and water quality

Abstract: Agriculture generates byproducts that may contribute to the contamination of our Nation's water supply. Any effective regulations to ban or restrict agricultural chemical or land use practices in order to improve water quality will affect the farm economy. Some farmers will benefit; some will not. Most agricultural pollutants reach surface waterways in runoff; some leach through soil into ground water. Because surface water systems and ground water systems are interrelated, farm management practices need to focus on water quality in both systems. Modifying farm management practices may raise production costs in some areas. Farmers can reduce runoff losses by reducing input use, implementing soil conservation practices, and changing land use. Also at issue is who should pay for improving water quality: farmers, governments, consumers, or those who benefit from improved water quality.

Goals and data collection designs for water quality monitoring

Abstract: Water quality monitoring cannot address every information need through one data collection procedure. This paper discusses the goals and related procedures for designing water quality monitoring programs. The discussion focuses on the broad information needs of those agencies operating water quality networks. These information needs include the ability to assess trends and environmental impacts, determine compliance with objectives or standards, estimate mass transport, and perform general surveillance. Each of these information needs has different data requirements. This paper outlines these goals and discusses factors to consider in developing a monitoring plan on a site by site basis.

Sediment and water yields from managed forests on flat coastal plain sites

Abstract: Sediment losses and water yields were measured for five years on nine forested watersheds in the Gulf Coastal Plain of Arkansas. After one year of pretreatment measurements, three watersheds were clearcut and mechanically site prepared, three were selectively harvested, and three control watersheds were left undisturbed. Sediment losses and water yields were similar for the selectively harvested and cohtrol watersheds during all four post-treatment years. However, clearcutting with mechanical site preparation significantly increased sediment losses and water yields above levels measured on other watersheds. Increased sediment losses persisted for two years, while water yields increased for one year. Although sediment losses from clear-cutting were greater than for other treatments, actual losses averaged only 264 kg/ha and 63 kg/ha for the first and second post-treatment years, respectively. The relatively low sediment losses are attributed to the flat terrain and the relatively low flow discharge rates that typify these sites.

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the lower-Colorado River valley, Arizona, California, and Nevada

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A regional approach for assessing attainable surface water quality: An Ohio case study

Abstract: Land classification systems are useful for identifying areas of relative homogeneity among which attainable water quality varies according to predominant land type and present use. Five ecological regions in Ohio were delineated to evaluate a framework for assessing attainable water quality in small streams. Streams in relatively unimpacted, representative watersheds were selected in each region. Various water quality variables were sampled over a 16-month interval from July 1983 through November 1984. The highest water quality consistently occurred in the southeastern region; the lowest in the northwestern region. The correspondence between spatial patterns in water quality variables and the delineated regions, together with multivariate classification of the streams based on their major ion chemistry and nutrient richness, support the hypothesis that regional differences in attainable surface water quality occur and that a land classification system is useful for characterizing attainable water quality goals. Such a framework should be useful for planning, implementing, and monitoring pollution control programs.