Showing papers on "Water quality published in 1983"

Environmental Health Engineering in the Tropics: An Introductory Text

Abstract: HEALTH AND POLLUTION Engineering and Infectious Disease Health and Water Chemistry Water Quality and Standards WATER SUPPLY Water Supplies in Developing Countries Rural Water Supply Urban Water Supply and Water Treatment EXCRETA AND REFUSE: TREATMENT, DISPOSAL AND RE-USE Excreta Disposal in Developing Countries Types of Excreta Disposal System Planning a Sanitation Program Waste Water Treatment Surface Water Drainage Refuse Collection and Disposal Composting Health Aspects of Waste Re-use ENVIRONMENTAL MODIFICATIONS AND VECTOR-BORNE DISEASES Engineering Control of Arthropod Vectors Dams, Irrigation and Health Schistosomiasis Appendices Index

Design of Networks for Monitoring Water Quality

Abstract: Design of networks for monitoring water quality , Design of networks for monitoring water quality , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Groundwater Contamination in the United States

Abstract: Ground water contamination is of increasing concern in the United States because about 50 percent of our drinking water comes from well water. The causes of contamination stem from both point sources and nonpoint sources. Since ground water moves slowly, the contaminant may affect only a small portion of an aquifer for a considerable period of time. Deleterious effects on human health have resulted from pathogenic organisms in ground water and from its toxic chemical composition. It is difficult to estimate the extent of contamination on a national basis as the frequency of instances of contamination is very variable. Remedial actions to clean up aquifers are difficult, expensive, and sometimes not feasible. Many of the laws and regulations that control ground water contamination are designed with other main objectives.

Mathematical modeling of water quality : streams, lakes, and reservoirs

Abstract: This book is the first to deal comprehensively with the subject of mathematical modeling of water quality in streams, lakes, and reservoirs. About one third of the book is devoted to model development processes -- identification, formulation, parameter estimation, calibration, sensitivity testing, and application -- and a thorough review of the mathematical principles and techniques of modeling. Emphasis is placed on well documented models, representative of the current state of the art, to illustrate capabilities and limitations for the simulation of water quality. About two thirds of the book deals with specific applications of models for simulation of water quality in natural water bodies. Topics covered include modeling of temperature, dissolved oxygen and phytoplankton growth in streams, development and application of one-dimensional models of stratified impoundments, two- and three-dimensional modeling of circulation and water quality in large lakes, thermally stratified plumes and cooling ponds, ecology of lakes and reservoirs, modeling of toxic substances, and the use of models in water quality management and decision making.

Water quality consequences of conservation tillage: New technology is needed to improve the water quality advantages of conservation tillage

Abstract: CONSERVATION tillage, which leaves some or all of the residue from the previous crop on the soil surface, effectively protects the soil against erosion. Use of conservation tillage has other environmental implications as well, particularly for water quality. The reduced soil erosion possible with conservation tillage compared with moldboard plow or clean tillage systems is an obvious advantage because of the reduction in sediment and sediment-associated chemical losses. In some cases, runoff is also less with conservation tillage, which can reduce losses of soluble, nonadsorbed chemicals. However, maintenance of crop residue on the soil surface currently limits fertilizer and pesticide use options in conservation tillage, thus affecting chemical concentrations and losses in surface runoff water and sediment. Water quality concerns Drainage water and sediment from agricultural land carrying dissolved and adsorbed nutrients and pesticides are major sources of nonpoint pollution. The primary nutrient forms carried are ammonium-nitrogen (NH4-N), nitrate-nitrogen (NO3-N), and phosphate-phosphorus (PO4-P). These are discussed in an Environmental Protection Agency document, “Quality Criteria for Water” (22). The volume recommends criteria for different water quality goals. However, knowledge of the kind and extent of effects of dissolved chemicals on water quality is incomplete …

An index associated with nutrient eutrophication in the marine environment

Abstract: The annual loadings and distributional patterns of phosphorus and nitrogen were observed at several stations in the Saronicos Gulf, Aegean Sea during 1980. All nutrient concentrations peaked sharply in the northern part of the Gulf where a sewage outfall exists. A ‘nutrient index’ designed to take into account the nutrient's loading of the area, to be specific for each nutrient and sensitive to stressful concentration changes, is described. The score values of this index provide a continuous assessment of water quality.

Chironomid Taxa Richness: Natural Variation and Use in Pollution Assessment

Abstract: Taxa richness of the benthic macroinvertebrate community is often used as a simple and reliable water quality indicator. However, taxa richness for Chironomidae (SC) may be less effective. SC in unstressed ecosystems may vary with differences in stream size and season. A diverse chironomid community may be present in some moderately polluted environments. A comparison of SC with taxa richness for the intolerant Ephemeroptera, Plecoptera and Trichoptera (SEPT) showed no significant relationship. Also, the effects of sediment may complicate use of SC in water quality work. SEPT was consistently found to decline with sediment addition, but the response of SC was flow dependent.

Trend Assessment of Water Quality Time Series

Abstract: A general methodology is described for identifying and statistically modeling trends which may be contained in a water quality time series. A range of useful exploratory data analysis tools are suggested for discovering important patterns and statistical characteristics of the data such as trends caused by external interventions. To estimate the entries in an evenly spaced time series when data are available at irregular time intervals, a new procedure based upon seasonal adjustment is described. Intervention analysis is employed at the confirmatory data analysis stage to rigorously model changes in the mean levels of a series which are identified using exploratory data analysis techniques. Furthermore, intervention analysis can be utilized for estimating missing observations when they are not too numerous. The effects of cutting down a forest upon various water quality variables and also the consequences of acid rain upon the alkalinity in a stream provide illustrative applications which demonstrate the effectiveness of the methodology.

Effects of acidity, calcium, and aluminium on fish survival and productivity—a review

Abstract: Fish survival, growth and productivity are dependent on both biological and environmental factors. The latter can be distinguished as edaphic (which includes water quality) and morphometric (which includes lake and stream morphology). Climatic factors are relatively less significant in temperate waters, except over a long time scale, or over wide geographic areas. In the conditions characteristic of acid lakes— low pH, low calcium and high aluminium concentrations—survival may be reduced, growth may be affected and, consequently, productivity will be low. In spite of inconsistencies in the literature, it can be shown that at low pH (⋍ 4.5), a limiting concentration of calcium is about 1 mg litre−1 and aluminium can have adverse effects at 250 μg litre−1 within a limited range of pH. These three factors appear to interact. Taking age specific fecundity of adults and survival of eggs and fry, it is possible to predict the limiting conditions for maintenance, growth or decline of a fish population. At pH 4.5 and calcium < 0.8 mg litre−1 it may be expected that many lakes will be fishless.

Significance of eutrophication in water supply reservoirs

Abstract: Key relationships between eutrophication of surface water supplies and the costs and quality of finished water are reviewed, with an emphasis on problems relating to organics. Data from lakes and reservoirs in the United States indicate a positive correlation between total phosphorus and total organic carbon measurements. I n view of this correlation and results of controlled laboratory studies reported in the literature, nutrient enrichment is a significant factor contributing to organohalide problems in surface water supplies. Watershed management for control or reduction of phosphorus export is suggested as a potentially significant and cost-effective means of dealing with organics-related problems. Regionally calibrated empirical models can be used in conjunction with appropriate reservoir and watershed monitoring data to assess the extent. significance. and controllability of water quality problems related to phosphorus export and eutrophication. Reservoir water quality is a complex function of its morphometry and water­ shed characteristics. including climate. hydrology, geology, morphology, and land uses. Rational planning and operation of water supply systems requires recogni­ tion of the cause-effect relationships that influence water quality and. therefore. influence the feasibility and costs of sup­ plying water that meets state and federal standards and criteria. The trend toward increasingly restrictive drinking water standards can be attributed to increased scientific understanding of the relation­ ships between drinking water quality and health and to vast improvements in analytical capabilities. particularly with respect to organics.' Given this trend and the current and projected water-supply shortages in many areas of the country, the protection or enhancement of source water quality will become increasingly critical. Watershed management programs are potentially cost-effective in relation to treatment schemes that may be required to meet finished water quality objectives. 2 For example. the expenses involved in constructing and operating a new filtra­ tion plant. which may become necessary as a result of increasing turbidity con­ centrations in a reservoir, seem likely to exceed the costs of stabilizing certain eroding areas of a watershed. The in­ n uence of watershed erosion on suspend­ ed solids and turbidity concentrations in a downstream reservoir is a cause-effect relationship that is easily grasped. al­ though factors other than erosion (e.g .• algal growth or iron released from anoxic sediments) could also contribute to high turbidity levels. Although source protec­ tion is important for all water suppliers, 38 RESEARCH AND TECHNOLOGY it is especially critical for small systems. Because of the considerable economies of scale associated with water treatment costs.3 the unit costs of additional treat­ ment. which may be required to offset degrading source quality or to meet new. more restrictive standards. are likely to have larger economic impacts on smaller systems. especially if new capital in­ vestments are required. Management of watersheds for quality protection has been hindered by limited knowledge of the factors and processes involved in nonpoint source pollution and reservoir dynamics. The state of the art in these areas has improved consider­ ably in the past ten years, although these improvements are not reflected widely in current policies and practices. Scientific understanding of eutrophication. which results from the discharge of excessive levels of aquatic plant nutrients into water bodies. has advanced to the point of providing predictive models that have been used widely in managing recrea­ tionallakes. 4 This article reviews some of the key effects of eutrophication on water supplies. with a focus on organics.

Soil conservation and water quality improvement: What farmers think

Abstract: DEBATE continues in the American agricultural community over policy for achieving soil conservation and the reduction of nonpoint-source pollution. This debate is sharpened by the goals to reduce nonpoint-source pollution expressed in such legislation as Section 208 of the Federal Water Pollution Control Act Amendments of 1972, the Clean Water Act of 1977, the Soil and Water Resources Conservation Act of 1977, and the Rural Clean Water Program outlined in the Agricultural Appropriations Act of 1980. “Best management practice” is a term commonly used to identify a practice or system of practices for controlling agricultural nonpoint-source pollution. Technical information on such practices attests to their effectiveness for improving water quality. But adoption of best management practices by farmers has been hampered by differences in perceptions between public officials and farmers as to what factors influence decisions. Most economic modeling studies of soil conservation and water quality issues use linear programming. Such studies assume that a farmer's primary motivation is profmaximization. But, there may be other factors involved in a farmer's adoption of best management practices. Personal valuse and beliefs, neighborhood and social pressures, and traditions may have as much or more …

Water Pollution and Management

Abstract: Buku ini menyajikan hasil penelitian tentang pencemaran air dan penanganannya yang dibahas dengan cara pandang multi-disiplin. Artikel-artikelnya telah dipilih dari serangkaian materi dari Aquatic Ecology Course yang diselenggarakan di Jawahalal Nehru University dengan bantuan Central Board for the Prevention and Control of Water Pollution, New Delhi. Topik-topik yang termasuk dalam buku ini adalah: Aquatic Ecosystem, The Aquatic Environment, Eutrophication, Energy Flow Through an Aquatic Ecosystem, Water Budgeting and Planning, Pollution of Surface and Ground Waters, Pesticide Pollution of Water, Heavy Metals in Aquatic Environment, Thermal Pollution, Radioactive, Pollution in the Environment, Environmental Impact of Nuclear Industry, Fisheries and Water Pollution, Concepts of Criteria and Purity Standards In water Quality Management, Biological Indicators and Indices of Water Quality, Water Resources Management, Natural Regeneration Capacity of Natural Waters.

Invertebrates and urban runoff in a small northern stream, Edmonton, Alberta, Canada

Abstract: The invertebrate fauna of a small northern stream was examined within Edmonton, Alberta. Many invertebrates that were common upstream of the city were absent or rare within the city. In contrast, some tubificids and chironomids were very abundant within the city. Diversity and richness (number of taxa) of the fauna were much lower within Edmonton than upstream, while the total density was much higher within the city. These changes in the urban invertebrate fauna were apparently caused by the discharge of organic materials and silt from storm sewer runoff. Chemical analysis of routinely-collected water samples did not show significant differences between urban and non-urban sites. This was probably due to the sporadic nature of storm sewer runoff. Peak levels of contaminants in the stream were usually missed because of the routine nature of sampling. Aquatic invertebrates, which exhibit long-term responses to sporadic runoff incidents, provided a better indication of stream water quality than did routine chemical monitoring.

Impacts of Silviculture on Flatwoods Runoff, Water Quality, and Nutrient Budgets

Abstract: Three forest watersheds were isolated by roads in poorly drained flatwoods of Florida. After 12 months of baseline calibration the forest in one watershed was harvested and regenerated with minimum disturbance, in the second watershed with maximum disturbance from common practices, and in the third watershed left intact as a control. Water yields from the maximum treatments increased a significant 250 percent while that from the minimum treatments increased 117 percent as compared to the control. Weed vegetation remaining after the minimum treatment continued significant water use. The water yield increases lasted only for one year. Water quality was reduced by both treatments with the most effect immediately after the maximum disturbance. Absolute levels of suspended sediments, potassium, and calcium remained relatively low. The maximum treatment caused significant changes in net cation balances only for one year. The information shows relative little effect of silvicultural practices in flatwoods on water quality as compared to data from upland forests. Water yield increases may be manipulated by the degree of harvest and weed control practices.

Concentration of coliphage from water and sewage with charge-modified filter aid.

Abstract: Methods of detecting and concentrating animal viruses from large volumes of water and wastewater have experienced rapid development in recent years, but only a few methods are available for the concentration of bacteriophages The present study describes the use of a charge-modified (Zeta Plus) filter aid (AMF Cuno, Meriden, Conn) for the concentration of coliphages from large volumes of water and sewage Coliphages MS-2 and f2 were efficiently adsorbed from water and sewage to the positively charged filter aid Elution was accomplished with 4% beef extract--05 M NaCl adjusted to pH 95 The recovery of f2 from 10- to 20-liter volumes of tap water ranged between 11 and 70%, and the recovery of MS-2 ranged between 43 and 70% The efficiency of recovery of naturally occurring coliphages from secondarily treated sewage ranged between 16 and 44% This technique appears to be promising because it requires low-cost equipment (47-mm polypropylene filter housing), is easy to handle, and can filter large volumes of water (greater than or equal to 20 liters) with good recoveries Filtrations can be conducted at the ambient pH of the water, and the unit cost per filtration (ie, the cost of filter aid) comes to less than three cents per sampling The technique could be useful in evaluation of viral water quality, study of ecology and occurrence of phages in natural waters, and isolation of rare phages from natural waters

Restoration of a Disused Dock Basin as a Habitat for Marine Benthos and Fish

Abstract: (1) Changes in the water quality, and in flora and fauna, of a Liverpool dock have been monitored since closure of its gates in 1977. Water salinities have been found to fall within the ranges 25-31%o, and temperatures 03-19 OC. Secchi disc extinction depths averaged 5-6 m in the dock and 10 cm in the Mersey estuary outside. An air-lift pump has been installed which prevents stratification during summer and ensures an oxygenrich water column. The absence of harmful dinoflagellate blooms is attributed to artificial destratification by this method. (2) Improvements in water quality have been accompanied by the development of a more diverse marine flora and fauna than in other unclosed docks. The benthic community is dominated by Mytilus edulis. Trace metal concentrations and coliform bacterial counts in Mytilus flesh are sufficiently low for the animals to comply with existing food safety regulations. Introduced Laminaria saccharine grew until water temperatures reached 15 OC, but a few plants survived a 14-week period in summer 1981 when ambient water temperatures were above 15 ?C. (3) It is concluded that a dock of this character can be maintained as a productive marine environment with a variety of educational, amenity and economic uses.

Literature relevant to remote sensing of water quality

Abstract: References relevant to remote sensing of water quality were compiled, organized, and cross-referenced. The following general categories were included: (1) optical properties and measurement of water characteristics; (2) interpretation of water characteristics by remote sensing, including color, transparency, suspended or dissolved inorganic matter, biological materials, and temperature; (3) application of remote sensing for water quality monitoring; (4) application of remote sensing according to water body type; and (5) manipulation, processing and interpretation of remote sensing digital water data.

Stormwater Quality Characteristics in Detention Basins

Abstract: The use of stormwater detention basins for the dual purpose of flood control and mitigation of pollutant runoff loads has been promoted. However, only limited data and methods for analysis and prediction of pollutant removal in detention basins exist. This paper presents the results of a stormwater quality sampling program conducted to describe the particle size distribution and the time variable influent and effluent concentrations of chemical oxygen demand, total phosphorus, total kjeldahl nitrogen, and solids during various storm events. Concentrations in three separate particle size ranges for each of the four parameters was determined. The basin is shown to be generally effective in reducing solids, chemical oxygen demand, (COD), and total phosphorus. Total kjeldah nitrogen (TKN) concentrations and loadings were generally increased. The effectiveness of the detention basin in reducing pollutant loads appears to be related to two factors, namely, equalization and sedimentation. Dry weather water quality in the detention basin determines the importance of the former, whereas the particle size distribution for each pollutant determines the degree of sedimentation.

Microbial indicator systems for assessing water quality

Abstract: of fermented meats as their numbers increase during normal production (Niven, 1963). E. coli seems the best indicator organism as it is of faecal origin and grows only very slowly if at all at refrigeration temperatures. Enumeration of bacteria in raw meats is also performed to assess the general level of contamination, and thus probable shelf life. Aerobic plate counts are suitable for this purpose. Incubation can be at 37 ~ when examining carcasses immediately after slaughter (Roberts et al., 1980b), but a lower incubation temperature (usually 25 ~ is necessary for meat stored chilled because the microflora is then mostly composed of psychrotrophic bacteria.