bluuebunny/crossref_metadata_2025 huggingface dataset:
MULTIPLE PURPOSE RIVER DEVELOPMENT
Authors: Wolman Abel
Published: February 2018

Water resources development on the North American continent has followed an irregular pattern, with randomness and planning existing side‐by‐side, and even planning varying widely in its aims‐and how often it was followed. Much of this is examined, trends are discerned, and a few pitfalls are pointed out for those who are embarking upon water resources development.
SMALL QUANTITY FIELD DISINFECTION
Authors: O'Connor John T. , Kapoor Surinder K.
Published: February 2018

Globaline and halazone have been used as disinfectants since the second World War. Currently, both are undergoing re‐evaluation to find a disinfectant tablet that can dissolve fast and still pass the tests of storage and time.
FOAM SEPARATION CLARIFICATION OF NATURAL WATERS
Authors: Grieves R. B. , Conger W. L. , Malone D. P.
Published: February 2018

This report is an investigation presenting a complete analysis of the effectiveness of continuous foam separation in removing natural water turbidity. It contains 82 individual experiments and an estimate of operating costs for a 1,000 gpd unit.
MATHEMATICAL MODEL FOR WATER–WASTEWATER SYSTEMS
Authors: Weddle Clark L. , Mukherjee S. K. , Porter J. W. , Skarheim H. P.
Published: February 2018

Determining the most economical usage of all water sources, including conventional sources, desalted seawater, and renovated wastewater, is a problem that will be encountered more and more frequently. The authors present a network analysis‐based model for selecting the least‐cost water supply and wastewater disposal system for a municipal area.
LOPEZ WATER SUPPLY PROJECT
Authors: Lawrance Charles H. , Tranbarger Keith G. , Drahn Richard A.
Published: February 2018

This project, recently completed in San Luis Obispo County, Calif., is an unusual multipurpose water‐supply system. It successfully combines water conservation, public water supply, recreation, flood protection, and the preservation of fish and wildlife.
Membrane and Ion‐Exchange Processes ‐ A Review
Authors: Lynch Maurice A. , Mintz Milton S.
Published: February 2018

The process of reverse osmosis has been known for many years; its application to water desalting is little more than a decade old, however. Here is a synopsis of the developments that have accrued in the field within the brief span of time.
Application of Jar‐Test Analysis at Phoenix, Ariz.
Authors: Griffith J. David , Williams Robert G.
Published: February 2018

A Metricized Article

Jar testing and pilot‐plant work can prove valuable precursors in designing floc basins—as the authors of this article pointedly cite. They also are quite incisive in their refutation of some prevailing theories regarding mixing and settling times. By their preliminary research, the Phoenix water department has been able to trim design costs considerably.
Surge Control
Authors: Weaver Douglas L.
Published: February 2018

When a pump “quits” because of a power failure, a high‐pressure wave will develop and traverse back and forth throughout the system. Pressures, from this and other precipitous system changes, may increase by a factor of two or more and lead to stress damage of system components. The use of the right sort of relief valve can lessen, even eliminate, such surges.
20 Yr of Fluoridation in San Francisco
Authors: Tracy Harry W.
Published: February 2018

The flouridation system now performing within San Francisco's water system is not the one that first went on‐stream a score of years ago. Here's a brief history of its evolvement.
An Improved Method for Determining Organics by Activated Carbon Adsorption and Solvent Extraction—Part I
Authors: Buelow Ralph W. , Carswell J. Keith , Symons James M.
Published: February 2018

Increasingly, organics in water are receiving attention. According to the authors of this article, there has been no apparatus that combines the features of low cost, reliability, portability, and ease of use—until now. Here is a first installment, detailing the apparatus and describing, generally, the ramifications of testing. In March, the JOURNAL will publish complete test procedures.
Evaluation of Plant Operating and Jar‐Test Data
Authors: Hudson H. E.
Published: February 2018

Flocculating and settling‐velocity test data can be used to revise plant design. The author describes how results may be plotted so that comparisons between lab and plant tests are more valid.
Solubility and Occurrence of Lead in Surface Water
Authors: Hem J. D. , Durum W. H.
Published: February 2018

The data in this article suggest methods of reducing the lead content of drinking water at the water‐treatment plant.
The Homestead Typhoid Outbreak
Authors: Pfeiffer Kenneth R.
Published: February 2018

Early this year, the popular press reported the outbreak of typhoid in Dade County, Fla. The facts at the time were diffuse, and when a problem developed with the nearby Miami Beach system,* concern developed that the Dade–Miami Beach incidents might be linked. Here are the facts relating to the events that took place in what was an isolated event in a Dade County migrant labor camp. An analysis of the facts as they relate to the source of outbreak is also presented.
Salt‐Water Intrusion and Its Control
Authors: Todd David K.
Published: February 2018

Salt‐water intrusion is a natural and troublesome phenomenon that renders ground water unpotable. It must therefore be controlled or eliminated where possible. Presented here are various means of preventing salt water from contaminating ground‐water sources of drinking water.
Demand‐Rate Economics
Authors: Lobb Howard J.
Published: February 2018

Because of rapidly rising costs, equity in rates is receiving greater attention from both the water consumer and the utility. One method for just assessment is thought to be the demand‐rate system, elements of which are explained in the following article.
Analysis + Efficiency = Power Savings
Authors: Ashmore Willard O. , Howard William S.
Published: February 2018

By using an Energy Efficiency Index, and evaluating the effect of modified operating procedures on this index, the Saginaw‐Midland Water Supply System was able to achieve greater efficiency in its use of energy. It is suggested that these methods could be applied by other systems that utilize pumping stations to save power and thus save money as well.
The Effect of Inflation on Water‐Utility Budgets
Authors: Shields John R.
Published: February 2018

During the past few years, inflation has required water Utilities to modify their budgetary practices. It is now more important than ever to use all facets of input in preparing the budget. Information on past programs, present practices, and new changes within the Utility as well as overall economic conditions in society is necessary to the development of a budget that will meet the full requirements of the Utility with the establishment of clear priorities.
Liquid Extraction for the Rapid Determination of Halomethanes in Water
Authors: Richard John J. , Junk Gregor A.
Published: February 2018

A rapid and simple method is described for the determination of halomethanes in water. The procedure involves vigorous shaking of water and pentane with subsequent gas Chromatographie analysis of the pentane extract using an electroncapture detector. Less than 0.1 μg/l in a 10‐ml water sample is easily detected.
Disinfection—Where Are We?
Authors: Symons George E. , Henderson Kenneth W.
Published: February 2018

Passage of the Safe Drinking Water Act and recent concern over chlorinated organics in potable water has quickened interest in the technology of water disinfection. The authors review the present state of water‐disinfection technology and provide a glimpse of what the future might hold.
Gravity Thickening of Water Treatment Plant Sludges
Authors: Kos Peter
Published: February 2018

Research concerning the behavior of Sludges during the gravity thickening process is described in this article.
Consumer Notification – Public Awareness or the Smoking Pistol?
Authors: Gaston John M.
Published: February 2018

The author expresses his opinion on the effect that the mandatory public notification provision of the Safe Drinking Water Act will have upon water utilities and consumers.
Water Consumption Under Peak‐Responsibility Pricing
Authors: Flack J. Ernest , Roussos George J.
Published: February 2018

The probable impacts of a shift to peak‐responsibility pricing on water consumption by several categories of user in the Denver, Colo., service area are predicted.
Algae Control in Water‐Supply Reservoirs
Authors: Muchmore Charles B.
Published: February 2018

The following article presents a literature review on the topic of copper sulfate and other algae‐control methods for water‐supply reservoirs.
Why Consider Water Conservation?
Authors: Sharpe William E.
Published: February 2018

Water conservation is a fact of life for the water industry and can be of benefit both to utilities and to their customers. But planning and pricing policies must be geared to offset potential adverse impacts on revenues.
Water Conservation‐A Practical Approach
Authors: Rice I.M. , Shaw L.G
Published: February 2018

Dallas, Texas, is trying to encourage water conservation—by appealing to the consumer's pocketbook as well as his conscience.
Pesticidal Residue in Rural Potable Water
Authors: Sandhu Shingara S. , Warren W.J. , Nelson Peter
Published: February 2018

The results of an intensive study of the nature and extent of pesticidal pollution of rural drinking‐water supplies in two geographically contrasting South Carolina counties are reported.
Increasing Water and Sewer Rate Schedules: A Tool For Conservation
Authors: McGarry Robert S. , Brusnighan John M.
Published: February 2018

To encourage water conservation and waste reduction, the Washington Suburban Sanitary Commission has implemented a conservation‐oriented rate structure that has succeeded in reducing average daily and peak consumption by residential customers, though not as yet by commercial or governmental water consumers.
Developing a Conservation Program Tailored to Area Needs
Authors: Minton Gary R. , Williams Richard , Murdock Thomas
Published: February 2018

Reported here are the results of an analysis conducted to determine the most appropriate water conservation program for Anchorage, Aka., one of the fastest growing urban centers in the US.
Source and Level of Mercury in a New Impoundment
Authors: Meister John F. , DiNunzio James , Cox James A.
Published: February 2018

The source of mercury in fish in a new impoundment was identified in this study as the inundated soil. The mercury in the soil was introduced into the food chain by direct uptake by microorganisms, rather than by a dissolution process; thus, the mercury level in the fish is not indicative of the quality of the impoundment as a public water supply.
The Use off GAC Filtration to Ensure Quality in Drinking Water From Surface Sources
Authors: Schalekamp Maarten
Published: February 2018

To ensure that the quality of drinking water derived from Swiss lake water is not inferior to that of well or groundwater, GAC filtration is indispensable, and, at a cost of one eighth of the total treatment costs, its use is also economically feasible.
An Evaluation of Activated Carbon for Drinking Water Treatment: A National Academy of Science Report
Authors: Suffet I.H.
Published: February 2018

The National Academy of Science report on the use of activated carbon for drinking water treatment is reviewed here, with special emphasis on how the efficiency of adsorbents is defined.
Computer Modeling Programs: Tools for Model Operations
Authors: Lee Cesario A.
Published: February 2018

Engineers and planners need a system of computer programs to effectively analyze water distribution systems. The days of using a single computer program to solve for pressure and flow variables have passed. Capabilities such as extracting and combining networks and allocating loads are a must for optimal system operation. Manipulation, comparison, and checking programs provide efficient and accurate methods to process data and determine trends and solutions. The Denver Water Department successfully uses one such system to operate efficiently and control costs.
Bacterial, chemical, and mineralogical characteristics of tubercles in distribution pipelines
Authors: Tuovinen Olli H. , Button Kenneth S. , Vuorinen Antti , Carlson Liisa , Mair David M. , Yut Lynn Ann
Published: February 2018

Tubercle deposits collected from pipelines in the Columbus, Ohio, distribution system and examined for their microbiological, chemical, and mineralogical composition were found to contain several kinds of organisms, including sulfate reducers, nitrate reducers, nitrite oxidizers, ammonia oxidizers, sulfur oxidizers, and various unidentified heterotrophic microorganisms. Chemical analysis revealed that the tubercles consisted largely of iron oxides, although minor and trace elements were present in varying quantities.
The occurrence of trihalomethanes in public water supply systems of New York state
Authors: Schreiber Judith S.
Published: February 2018

An investigation into the occurrence of trihalomethane (THM) compounds and other synthetic organic chemicals in public water supplies was conducted in 1978 by the New York State Department of Health. In addition to the routine samples, four systems were chosen to be investigated for seasonal variation. Although the highest chloroform levels were generally found in the month of July, the January concentrations were also high. Five systems were selected for investigation throughout their distribution systems. Contrary to the expected result of increasing levels throughout the system, these findings indicated that the concentrations of chloroform were often highest at the treatment plant. Interpretation of the data according to source type, available treatment, and physical parameters is presented, and the potential impact of the US Environmental Protection Agency (USEPA) THM primary drinking water regulations is discussed.
Common pipe flow formulas compared with the theory of roughness
Authors: Lamont Peter A.
Published: February 2018

A brief review is made of the theory of roughness, of the test results on which the recommended roughness values were based, and of various exponential formulas (and their suitability) in common use in the United States. The author also presents a table of recommended values of the Hazen‐Williams coefficient C, based on a close comparison with the theory of roughness, which is a popular formula in the United States.
Synthetic adsorbents and activated carbons for water treatment: statistical analyses and interpretations
Authors: Weber Walter J. , van Vliet Benjamin M.
Published: February 2018

The second of a two‐part series evaluating alternative adsorbents for removal of trace organics from water supplies, this paper presents a statistical analysis of the comparative data and an interpretation of factors governing the performance characteristics of adsorbents for water treatment applications. The first paper presents an overview and experimental comparisons among eight of the more promising synthetic adsorbents and two reference activated carbons.
Direct filtation: polymer in backwash serves dual purpose
Authors: Yapijakis Constantine
Published: February 2018

Direct filtration has been used as a viable alternative to complete, conventional treatment systems that employ flocculation–sedimentation prior to filtration where the raw water source is relatively unpolluted and is low in color and turbidity. By adding a polymer to the water to be used for filter backwashing, a reduction of the initial turbidity breakthrough period and peak can be obtained in addition to a much Improved settling–thickening rate for the backwash solids.
Determining the concentration of easily assimilable organic carbon in drinking water
Authors: van der Kooij Dirk , Visser A. , Hijnen W.A.M.
Published: February 2018

This paper describes a method for determining the potential of a water for supporting microbial regrowth in a drinking water distribution system. The method is based on the growth of fluorescent pseudomonads as a function of the concentration of easily assimilable organic carbon (AOC) in water. Using this method, the authors analyzed water samples from various stages of water treatment and water in which samples of nonmetallic piping materials had been placed. The concentration of AOC in water increased if the water was ozonated or placed in contact with plasticized polyvinyl‐chloride.
Research needs for capacity planning
Authors: Lauria Donald T.
Published: February 2018

The goal of this subcommittee report is to identify gaps in existing knowledge regarding capacity planning for community water supply facilities so that an agenda for research priorities can be identified and adopted to eliminate deficiencies.
The economics off leak detection and repair—a case study
Authors: Moyer Ellen E. , Male James W. , Moore I. Christina , Hock John G.
Published: February 2018

This article analyzes the costs and benefits of a leak detection and repair program for a publicly owned water utility. The characteristics of different types of leaks and the accuracy of the detection method used are also discussed. The results of the analysis demonstrate that benefits outweigh costs and that the program has led to a substantial decrease in unaccounted‐for water without incurring greater repair costs for the system.
Standard plate count: A comparison of pour plate and spread plate methods
Authors: Taylor Raymond H. , Allen Martin J. , Geldreich Edwin E.
Published: February 2018

Water samples collected during routine flushing of dead‐end mains were analyzed for bacterial count by using both pour plate and spread plate procedures. Results from these analyses were compared statistically. The pour plate procedure was neither as accurate nor as precise as the spread plate procedure for enumerating the heterotrophic plate count population.
The ecology of acid‐fast organisms in water supply, treatment, and distribution systems
Authors: Haas Charles N. , Meyer Michael A. , Paller Marc S.
Published: February 2018

Eight locations in each of two water utilities were sampled for 18 months in order to collect data on acid‐fast organisms, total coliforms, standard plate count, membrane standard plate count, free and total chlorine residual, total organic carbon (TOC), pH, turbidity, and temperature. These data were analyzed by using computerized statistical packages. In raw water, densities of acid‐fast organisms correlated with concentrations of total coliforms and the level of turbidity. Sand filtration removed acid‐fast organisms, and the densities of acid‐fast organisms decreased with increasing distance from the treatment plant. Conventional terminal chlorination appeared to have no statistically significant effect on the density of the organisms leaving the plant. Overall, chlorine residuals had a negative effect on densities of acid‐fast organisms, whereas turbidity and TOC had positive effects on microbial concentrations.
The movement of typhoid organisms in saturated, permeable soil
Authors: McGinnis James A. , DeWalle Foppe
Published: February 2018

An outbreak of typhoid fever in Yakima County, Wash., is compared with 11 similar episodes of groundwater transmission of typhoid fever reported in the literature. The survival time and the distance bacteria can travel in groundwater are analyzed by using a linear regression correlated with the velocity of groundwater flow in various types of soils.
A predictive model for chloroform formation from humic acid
Authors: Engerholm Bruce A. , Amy Gary L.
Published: February 2018

Several mathematical equations (submodels) are used to formulate an overall model for predicting chloroform formation from humic acid in terms of time, initial total organic carbon (TOC), initial chlorine‐to‐TOC ratio, reaction temperature, and reaction pH.
Secondary utilization of trace organics by biofilms on porous media
Authors: Stratton Richard G. , Namkung Eun , Rittmann Bruce E.
Published: February 2018

Biofilm processes are potentially important for the removal of trace levels of organic compounds in water reuse schemes as well as in nature. This article describes the mechanism of secondary utilization in controlled biofilm reactors. Secondary utilization is the biodegradation of a secondary substrate, the metabolism of which is inconsequential to sustaining the cells. Trace levels of organics are good examples of secondary substrates because their concentrations are too low to support any significant cell mass. Experiments with five representative compounds demonstrated that secondary utilization can remove organic compounds from water, even when the input concentrations are low. Experimental and theoretical results showed that fractional removals are often increased as the input concentration is reduced.
Chlorination‐Filtration for Iron and Manganese Removal
Authors: Wong Joseph M.
Published: February 2018

Processes in which oxidation is followed by removal of suspended solids can effectively remove soluble iron and manganese from water. Three common processes for removing iron and manganese are: (1) aeration‐filtration, (2) chlorination‐filtration, and (3) potassium permanganate‐manganese greensand filtration. This article describes these processes and presents results from a pilot study of chlorination‐filtration. The costs for oxidants in chlorination‐filtration are less than those for potassium permanganate‐manganese greensand filtration.
Control of Trihalomethane Precursors in Drinking Water: Granular Activated Carbon With and Without Preozonation
Authors: Glaze William H. , Wallace James L.
Published: February 2018

In a pilot study that lasted 80 weeks, unozonated and ozonated waters were fed to granular activated carbon (GAC) columns to compare the removal of trihalomethane formation potential by GAC treatment with that by ozone‐GAC treatment. The results were comparable for these treatments.
The Groundwater Supply Survey
Authors: Westrick James J. , Mello J. Way ne , Thomas Robert F.
Published: February 2018

The results of the US Environmental Protection Agency, Office of Drinking Water, sampling and analysis of volatile organic compounds (VOCs) in finished water supplies that use groundwater sources are discussed. Concentrations of 29 VOCs in addition to five trihalomethanes and total organic carbon from 945 water supplies were measured. The five most frequently found compounds other than trihalomethanes were trichloroethylene, 1,1,1‐trichloroethane, tetrachloroethylene, cis‐ and/or trans‐1,2‐dichloroethylene, and 1,1‐dichloroethane. Approximately half of the samples were taken from a random list of water systems, which were subdivided into two sets of systems—those serving fewer than 10 000 persons and those serving more than 10 000 persons. The nonrandom samples were taken from systems selected by the states, using groundwater sources that were likely to show VOCs in drinking water. Large systems in the random sample had a significantly higher frequency of occurrence of VOC contamination than small systems and were also more likely to have higher levels of contamination.
Biofilm Fouling of RO Membranes—Its Nature and Effect on Treatment of Water for Reuse
Authors: Ridgway Harry F. , Justice Carol A. , Whittaker Christine , Argo David G. , Olson Betty H.
Published: February 2018

Increasing demand for domestic water has spurred renewed activity in the treatment of secondary municipal effluent to augment existing resources. Demineralization of pretreated wastewater by reverse osmosis yields safe, potable supplies, but microorganisms and chemical substances in the feedwater rapidly impede membrane flux, reducing plant efficiency and increasing treatment costs. The nature of biofilm development was studied at an advanced wastewater treatment plant in Southern California under low‐ and high‐chlorine conditions, where close relationships were found between the accumulation of biochemical material and the loss of membrane premeability. High chlorine residuals damaged the membrane structure and reduced mineral rejection capacity.
Polymerized Iron Chloride: An Improved Inorganic Coagulant
Authors: Leprince Antoine , Fiessinger Frangois , Bottero J. Y.
Published: February 2018

Laboratory, pilot‐scale, and full‐scale experiments were conducted to determine whether polymerized iron chloride (PIC) is a more efficient coagulant than conventional ferric chloride. Polymerized iron chloride, prepared either by adding alkali to the stock solution or by heating a dilute solution of the iron salt, was shown to be more effective than ferric chloride for turbidity removal, particularly at low water temperatures. Removal of organics, however, did not appear to be improved by the use of PIC.
Declining‐Rate Filters: Regulatory Aspects and Operating Results
Authors: Cornwell David A. , Bishop Mark M. , Dunn Howard J.
Published: February 2018

Although the current design trend is to use constant‐rate filters, significant operating data now show that use of declining‐rate filters includes such benefits as economy and ease of operation. A survey of state regulations showed that no specific requirements exist for the design and operation of declining‐rate filters and that the regulations often do not distinguish between the two types of filters.
Controlling Algae in Water Supply Impoundments
Authors: Raman Raman K.
Published: February 2018

The impact of algae in reservoirs on water supply, the lake eutrophication process, and various techniques used for controlling algae are discussed. Since copper sulfate is the chemical most commonly used to control algae in lakes, the chemistry of copper in the natural lake environment is reviewed, as well as methods for application of chemicals.
Dezincification Update
Authors: Jester Thomas C.
Published: February 2018

The occurrence of dezincification in valves and fittings made of brass alloys with a high content of zinc has caused relatively few problems in the United States although it is a problem in many parts of Europe and other areas. This is probably because AWWA standards call for the use of low‐zinc brass alloys. However, not all waters would subject high‐zinc brass to dezincification, so water suppliers should be aware of the mechanism and the causes and effects of this type of corrosion. The author provides a literature review and a summary of findings in studies undertaken since 1955 on dezincification.
Calculating the pH of Calcium Carbonate Saturation
Authors: Pisigan Rodolfo A. , Singley J. Edward
Published: February 2018

Two new expressions for the pH of saturation (pHs) were derived. One is a simplified equation developed from an aqueous carbonate equilibrium system in which correction for ionic strength was considered. The other is a more accurate quadratic formula that involves computerized calculation of pHs and takes into account ionic speciation and an activity correction factor. Different methods of determining pHs of 155 water samples were compared using the Langelier equation, the Larson–Buswell formula, the two pHs equations derived in this study, two mathematical models obtained from multivariate analysis, the WATSPEC2 computer program, and Caldwell–Lawrence diagrams.
The Effect of Slow Sand Filter Maintenance on Water Quality
Authors: Cullen Thomas R. , Letterman Raymond D.
Published: February 2018

Full‐scale municipal slow sand filters at seven sites in the Syracuse, N.Y., area were monitored before, during, and after filter scraping to verify the presence or absence of a ripening period, to determine the filter run length, and to quantify the labor and material required for scraping and resanding operations. Results showed some evidence of a ripening period, ranging from 6 h to 2 weeks, in four of the 10 operations monitored. The presence or absence of a ripening period did not seem to be related to the use of prechlorination, to water temperature, to scraping methodology, or to frequency of filter maintenance. The factor that seemed to have the most significant effect on the quality of the filtrate was the amount and nature of the particulate matter present in the raw water.
Potential Health Effects of Mercury in Water Supply Wells
Authors: Stolzenburg Thomas R. , Stanforth Robert R. , Nichols David G.
Published: February 2018

The cycling of mercury in the environment and in well water was studied to determine the seriousness of the threat to human health of the elemental mercury sometimes contained in water well equipment. Modeling of mercury cycling indicated that, because of unfavorable conditions, mercury in well water is highly unlikely to be methylated to the toxic methylmercury form. More important, aquatic organisms, such as fish and shellfish, that can concentrate methylmercury and could be consumed by humans are not present in well water.
Privatization of Water Systems in France
Authors: Deschamps Jean‐Dominique
Published: February 2018

Private companies in France, operating under the oversight of local municipal authorities, are responsible for a large share of the country's water and sewer utilities. Highly successful in providing state‐of‐the‐art technologies for the management and treatment of water and wastewater systems, these firms now have the financial and human resources to extend their operations abroad, thus providing leadership in the toward privatization of public services. The operations of the largest of these companies, the Compagnie Générale des Eaux, are described.
Full‐Cost Water Pricing
Authors: Goldstein James
Published: February 2018

Many municipal water systems have traditionally priced water at far less than the cost of service, thereby requiring subsidies from general funds. Conversely, some water revenues have been diverted to meet other expenses of the city. The author cites the benefits of separate accounting for water revenues and expenses and full‐cost pricing, drawing on the situation in Massachusetts. Increased efficiency and ultimate economies can be realized from allocation of sufficient funds to undertake rehabilitation and maintenance programs. Methods of structuring rates and implementing full‐cost rates are reviewed, and Boston's recent restructuring of water and sewer services is given as an example of improvements made possible by full‐cost pricing.
Oxidation of Five Earthy‐Musty Taste and Odor Compounds
Authors: Lalezary Shala , Pirbazari Massoud , McGuire Michael J.
Published: February 2018

Several commonly used techniques for removing organic taste and odor compounds from water were investigated. These techniques were originally designed to simulate water treatment conditions, but it was necessary to choose test conditions that were often extremes, such as wide ranges of dosages and contact times, so that more conclusive evidence of the efficiencies of these techniques could be determined. A comparison of equivalent dosages showed that chlorine dioxide was the most effective oxidant for removing the five selected compounds.
Posttreatment of Reverse Osmosis Product Waters
Authors: Applegate Lynn E.
Published: February 2018

Reverse osmosis (RO) product water usually requires posttreatment, regardless of the type of RO device, the chemical nature of the RO membrane, and the intended application of the water. Posttreatment requirements depend primarily on the application and must be determined on a case‐by‐case basis. For many industrial applications, posttreatment consists of demineralization by means of ion exchange and disinfection with ultraviolet radiation. Posttreatments for municipal applications include pH adjustment with bases or a degasifier (or both), reduction of corrosiveness, and disinfection with chlorine. Details of these posttreatments are given for RO product waters from brackish as well as seawater sources. The economics of these treatment processes are also presented.
Water Contamination Caused by Gasoline Permeating a Polybutylene Pipe
Authors: Leseman William G.
Published: February 2018

A water quality complaint received by the city of Tallahasse, Fla., resulted in an investigation that found contamination of a service line caused by gasoline leaking into the soil surrounding the pipe. The service connection to an apartment was the only incidence of the contamination, but levels of 1,2‐dibromoethane were found in one apartment to be 50 times the limit set by the Florida Department of Environmental Regulations. The service line was replaced with copper pipe, which solved the problem.
The Potential Toxicity of Uranium in Water
Authors: Wrenn McDonald E. , Durbin Patricia W. , Willis David L. , Singh Narayani P.
Published: February 2018

The nephrotoxic responses of mammalian species, including humans, to injected, inhaled, ingested, and topically applied uranium compounds have been thoroughly investigated. Because there appear to be no unequivocal reports of uranium‐induced radiation effects in humans, it is necessary to rely on experimental work with animals and on epidemiological investigations of human populations exposed to radium isotopes to infer human response to the alpha‐particle emissions of uranium. Metabolic models have been developed to relate the intake of uranium in water and food to its uptake in the human skeleton and soft tissues, of which the kidney is the critical organ. A US Environmental Protection Agency committee has recommended a limit for uranium in drinking water of 100 μg/L, which includes a substantial safety factor, to limit effects on the kidney.
Air‐Water Phase Equilibria of Volatile Organic Solutes
Authors: Munz Christoph , Roberts Paul V.
Published: February 2018

The equilibrium or Henry's constant, Hc, and the mass transfer rate constant, KLa, are the major factors determining the extent of transfer during bubble aeration and in countercurrent packed columns. This study delineates the limits of validity of Henry's law for nonionizing halogenated solutes and presents data on the effects of temperature and the addition of model cosolvents on the Henry's constant. The experimental results are compared with predictions from a semi‐empirical thermodynamic model and from vapor pressure and solubility data. No effect of solute concentration on the solute's Henry's constant was observed up to solute liquid mole fractions of $$10−3 Very high cosolvent concentrations, in excess of $$10 g/L, are required to reduce the solute's Henry's constant. The Henry's constant of the organic compounds studied increases by a factor of approximately 1.6 with each 10°C rise in temperature, representing a very strong effect. Thus, temperature is likely to be a key parameter affecting the extent of removal of volatile organic compounds in gas‐liquid contacting processes.
Removal of Taste‐ and Odor‐Causing Compounds by Biofilms Grown on Humic Substances
Authors: Namkung Eun , Rittmann Bruce E.
Published: February 2018

Laboratory experiments showed that biodegradation of taste‐ and odor‐causing compounds by biolfilms grown on natural humic materials is feasible. Although the mineralization of peat fulvic acid (PFA) was relatively low (about 10 percent), long‐term application of the PFA resulted in a significant amount of biofilm mass in the reactor and allowed the secondary utilization of trace levels of taste and odor compounds. These results suggest that biofilms grown on natural organic materials can play an important role in removing taste and odor compounds during water treatment. Examples of drinking water treatment processes that allow good biofilm accumulation are granular activated carbon, sand filters, river bank filtration, submerged fixed‐bed reactors, and fluidized‐bed reactors.
Comparing Aluminum and Iron Coagulants for In‐line Filtration of Cold Water
Authors: Haarhoff Johannes , Cleasby John L.
Published: February 2018

Pilot studies showed that with water temperatures <;37°F (3°C) and raw water turbidities <;2 ntu, ferric chloride removed turbidity more efficiently than did aluminum sulfate but that aluminum sulfate caused slower head loss development. The total clogging head loss at the onset of turbidity breakthrough, however, was approximately the same for both coagulants. Equivalent head loss development and turbidity removal were demonstrated at a molar iron‐to‐aluminum dosage ratio of 3:5.6.
Networking Urban Water Supplies in West Africa
Authors: Perry James A.
Published: February 2018

This article characterizes the diversity among four West African water supply systems and outlines problems faced by managers of these kinds of utilities. After having interviewed municipal water system managers in the Ivory Coast, Ghana, Burkina Faso, and Liberia, the author describes physical facilities, monitoring and analysis operations, and the regulatory framework within which each system operates. Solutions to common problems and the role of water utility professionals from the developed world are discussed.
A Review of Solid‐Solution Interactions and Implications for the Control of Trace Inorganic Materials in Water Treatment
Authors:   Trace Inorganic Substances Research Committee
Published: February 2018

This report describes the chemical and physical phenomena important for determining the partitioning of inorganic contaminants between solution phase and particulate phases. It illustrates how such considerations may be used to understand and manipulate conventional treatment processes to enhance the removal of inorganic contaminants and to inhibit the release of trace inorganic contaminants resulting from corrosion processes.
Trace Metal Contamination From Brass Fittings
Authors: Schock Michael R. , Neff Chester H.
Published: February 2018

Data were obtained during a two‐year field and laboratory corrosion study that implicated brass valves and fittings as a potential source of lead, copper, and zinc in drinking water, particularly in standing water. Contamination from this source was found to be a significant cause of metal concentrations that exceeded maximum contaminant levels. These findings should be considered in the design of water sampling programs, the selection of plumbing materials for household use, and the planning of corrosion‐rate measurement and plumbing material solubility experiments.
Controlling Organics with GAC: A Cost and Performance Analysis
Authors: Adams Jeffrey Q. , Clark Robert M. , Miltner Richard J.
Published: February 2018

The amendments to the US Safe Drinking Water Act require extensive evaluation of the feasibility of removing organic compounds using granular activated carbon (GAC). To meet deadlines for this technology evaluation, the US Environmental Protection Agency has combined the use of column studies and adsorption modeling with cost models to make projections for the performance of full‐scale GAC systems. A representative list of synthetic organic chemicals was studied, and cost and performance results for GAC treatment are presented in this article.
Using a Microporous Hollow‐Fiber Membrane to Separate VOCs From Water
Authors: Semmens Michael J. , Qin Ren , Zander Amy
Published: February 2018

The use of microporous polypropylene hollow fibers for separating volatile organic contaminants (VOCs) from water was evaluated. The water was pumped through the lumen of the fibers, and organic‐free air was pumped countercurrently on the outside of the fibers. The rate of VOC removal was modeled on the basis of known empirical correlations, and the experimental data compared favorably with theoretical predictions. The use of a membrane in the air‐stripping process offers several potential advantages over conventional packed‐tower aeration, including a higher overall mass transfer coefficient (KLa), a reduced dependence of KLa on gas flow rate, no upper limit on the gas flow rate that can be used, no need for mist elimination, and no need for tall structures.
Lead at the Tap: Sources and Control
Authors: Lee Ramon G. , Becker William C. , Collins David W.
Published: February 2018

A survey of 94 water companies and districts was conducted in early 1988 to determine lead levels at customer taps and to evaluate the factors that influence these levels. The results of the survey indicate that lead‐based solder is the most significant source of lead at the tap. In addition, brass faucets were found to contribute substantially to the lead in the first‐draw samples. Although water quality and site characteristics cannot be used to predict lead levels, certain factors are associated with higher lead concentrations. Other than the presence of corrosion inhibitors, pH was the only water quality factor that appeared to influence lead levels at the tap. Site factors were also important, with plumbing age being the most significant.
Determining Inorganic Disinfection By‐products by Ion Chromatography
Authors: Pfaff John D. , Brockhoff Carol A.
Published: February 2018

Disinfection by‐products will soon be regulated by the US Environmental Protection Agency under the 1986 amendments to the Safe Drinking Water Act. Because of its sensitivity and precision, ion chromatography is a good choice for analyzing by‐products of chlorine dioxide and ozone, i.e., chlorite, chlorate, and bromate, as well as several other anions.
Disinfecting Biofilms in a Model Distribution System
Authors: LeChevallier Mark W. , Lowry Cheryl D. , Lee Ramon G.
Published: February 2018

This study examined the disinfection efficiency of free chlorine and monochloramine for controlling biofilm organisms in a model pipe system. The composition of the pipe material was found to be a major influence on disinfection efficiency. Bacteria grown on galvanized, copper, or PVC pipe surfaces were readily inactivated by a 1‐mg/L residual of free chlorine or monochloramine. Biofilms grown on iron pipes treated with free chlorine doses as high as 4 mg/L (3‐mg/L residual) for two weeks did not show significant changes in viability, but if treated with 4 mg/L of monochloramine for two weeks, these biofilms exhibited a more than 3‐log die‐off. Accumulation of corrosion products on iron pipes was found to interfere with free chlorine disinfection.
Measuring and Modeling Variations in Distribution System Water Quality
Authors: Clark Robert M. , Coyle Judith A.
Published: February 2018

The authors describe a field study that examined the effects of hydraulic mixing on water quality variations in a distribution system. Conducted at the North Penn Water Authority (average production of 5 mgd and 225 mi of distribution pipe), the study incorporated a field sampling program that utilized customized automated samplers designed to prevent loss of volatile constituents. As a complement to the field sampling program, computer models that would predict water quality variations in distribution systems were examined and developed. A clear need was shown for obtaining more representative monitoring results than are normally acquired from distribution system sampling.
Comparative Subchronic Toxicity Studies of Three Disinfectants
Authors: Daniel F. Bernard , Condie Lyman W. , Robinson Merrel , Stober Judy A. , York Raymond G. , Olson Greg R. , Wang Shin‐Ru
Published: February 2018

In separate subchronic toxicity studies, male and female Sprague–Dawley rats received various dosages of chlorine, monochloramine, or chlorine dioxide in their drinking water for 90 consecutive days. None of the disinfectants caused premature death at any of the concentrations used. The highest dose of chlorine tested (250 mg/L) was concluded to be a no observable adverse effect level. At 200 mg/L (the lowest observable adverse effect level), monochloramine produced decreased body and organ weights in both sexes and a small decrease in red blood cell count and serum calcium in males. Chlorine dioxide produced dosage‐related decreases in body and organ weight at concentrations as low as 25 mg/L, but its most significant toxic effect was the induction, at all concentrations, of nasal lesions.
Evaluating the costs of Packed‐Tower Aeration and GAC for Controlling Selected Organics
Authors: Adams Jeffrey Q. , Clark Robert M.
Published: February 2018

This article focuses on a preliminary cost analysis that compares liquid‐phase granular activated carbon (GAC) treatment with packed‐tower aeration (PTA) treatment, with and without air emissions control. The sensitivity of cost to design and operating variables is also discussed. For most of the contaminants examined, PTA appears to be more cost‐effective than liquid‐phase GAC, even when vapor‐phase GAC is required in the stripping system.
Microbial Activity in GAC Filters at the Choisy‐le‐Roi Treatment Plant
Authors: Servais Pierre , Billen Gilles , Ventresque Claire , Bablon Guy P.
Published: February 2018

To maintain the biological stability of drinking water during distribution in large, complex networks, high standards have to be met—namely, low bacterial densities and low levels of biodegradable organic carbon. Second‐stage granular activated carbon (GAC) filtration (without regeneration of carbon) is used for this purpose at the Choisy‐le‐Roi, Paris, France, treatment plant. Effective removal of dissolved organic carbon has been observed with such filtration—mainly because of a reduction in the biodegradable organic carbon. To study the microbial processes involved in this removal, new methods based on the use of radio‐labeled tracers have been developed in order to measure the bacterial biomass and activity associated with GAC.
Agronomic Effects of Land Application of Water Treatment Sludges
Authors: Elliott H.A. , Dempsey B.A.
Published: February 2018

Economic, regulatory, and legal constraints on alternative disposal methods are raising interest in land application of water treatment sludges. Understanding the agronomic and environmental issues is essential before a land‐based disposal program is implemented. Water treatment sludges may favorably modify the pH and water‐holding capacity of soils but generally have little fertilizer value. Supplemental phosphorus (P) fertilizer will usually be needed to offset the strong P‐binding capacity of these sludges. Heavy metal concentrations can be limited in sludges primarily by controlling the purity of the coagulant chemicals.
European Drinking Water Standards
Authors: Carney Michael
Published: February 2018

This article summarizes drinking water standards that apply to member states of the European Community, considers the extent to which the standards have been met, and discusses likely future developments.
Effectiveness of Natural Polyelectrolytes in Water Treatment
Authors: Kawamura Susumu
Published: February 2018

Synthetic polyelectrolytes are widely used in the United States because of their effectiveness as a coagulant or coagulant aid. Synthetic polyelectrolytes produce a lower volume of sludge compared with alum flocculation, and their effectiveness is not much affected by the pH level of water. Synthetic polyelectrolytes provide better dewatering characteristics in sludge produced and facilitate better filter performance. However, one drawback of these products is that their long‐term effects on human health are not well understood. Natural polyelectrolytes such as chitosan (cationic) and sodium alginate (anionic) are not only as effective as or even more effective than their counterparts at similar dosages, but they also do not cause any adverse effects to human health. This article presents results of bench‐ and pilot‐scale tests that compared natural and synthetic polyelectrolytes. It suggests that natural products would be workable substitutes for synthetic products.
Modeling the Risk From Giardia and Viruses in Drinking Water
Authors: Regli Stig , Rose Joan B. , Haas Charles N. , Gerba Charles P.
Published: February 2018

This article discusses the assessment of risk from microorganisms in drinking water, the problems associated with such an analysis, the approach for specific organisms, the monitoring required to demonstrate that risk levels are met, and how risk assessment might be approached for determining whether a given level of risk from Giardia and viruses is avoided. Guidelines are suggested for determining the level of treatment necessary to ensure that consumers receive a finished drinking water with risks of less than one infection per 10,000 people per year from Giardia and enteric viruses.