bluuebunny/crossref_metadata_2025 huggingface dataset:
Coagulation Mechanisms: An Electron Microscopic Study Using Aluminum Sulfate
Authors: Ishibashi T.
Published: February 2018

New research findings verified by electron photomicrographs indicate that the efficiency of coagulation is less influenced by zeta potential than was formerly believed. Adsorption of potential‐determining ions and bridging explain the observed phenomena better than the generally held double‐layer theory of coagulation.
Initial Degradation of Effluent Quality During Filtration
Authors: Amirtharajah A. , Wetstein Daniel P.
Published: February 2018

Although the initial degradation of effluent quality from a granular media filter has important implications for the design and operation of filters needed to produce extremely high quality water, this problem has not previously been investigated in depth. The mechanism responsible for the poor effluent appears to involve an interaction between the backwash stage and the initial stages of filtration, during which a degradative phase is followed by an improving phase.
The Bed Depth Service Time Design Method for Deep Bed Filtration
Authors: Saatçi Ahmet M. , Oulman C.S.
Published: February 2018

The bed depth service time (BDST) method, a simple means for evaluating the coefficients needed in filter design, can provide a rational basis for the design of a deep bed filter. Once determined, these coefficients, along with estimates of head loss, can be used to evaluate the effects of flow rate, filter length, and influent concentration and effluent suspended solids concentration on the length of a filter run. The coefficients can be determined in pilot plant tests using filters of various lengths or, with a somewhat lower accuracy, from the performance of a single existing filter.
Threading the Regulatory Maze: A Small Utility's View
Authors: Palmer Cary R. , Gronning Lloyd J. , Ketellapper Walraven F.
Published: February 2018

The experience of Thornton and other Colorado communities with recent federal sponsorship of and involvement in water projects is that new federal requirements are burdensome and costly in terms of time, inconvenience, and hidden expenses. Communities would do well to weigh very carefully the costs and benefits of federal grant monies and the use of federal lands before committing to future projects.
Change: a management problem or a problem with management?
Authors: Hayashida Kazu
Published: February 2018

When certain functions become obsolete, new and innovative programs must be introduced if the utility is to maintain its level of productivity. If management shirks this responsibility, problems and inefficiencies will continue, and change will then become a problem with management.
Elevated levels of sodium in community drinking water
Authors: Calabrese Edward J. , Tuthill Robert W. , Klar Janelle M. , Sieger Thomas L.
Published: February 2018

A comparison study of students from towns with differing levels of sodium in drinking water revealed statistically significantly higher blood pressure distributions among the students from the town with high sodium levels. Differences were found in both systolic and diastolic readings, in boys as well as girls.
Response of lead solubility to dissolved carbonate in drinking water
Authors: Schock Michael R.
Published: February 2018

Because of the potential toxicity of lead and its deleterious effects on human health, increased attention has been given to the use of lead piping materials in household plumbing. Water that is corrosive to lead has been observed to leach considerable amounts of lead from pipes, especially after the water has been standing in the pipes for several hours. This paper presents a revised model showing the detailed response of the theoretical solubility curves for lead to changes in dissolved inorganic carbonate concentration (Ct) and pH at 25°C. The model agrees well with previously published pipe loop solubility experimental data as well as with pipe coupon tests and precipitation data at high Ct.
Analytical note: catalytic effects of sulfur and other compounds in the azide–iodine test
Authors: Tuovinen Olli H. , Lapple William J. , Mair David M.
Published: February 2018

In the azide‐iodine reaction employed for corrosivity testing, nitrogen gas evolution is catalyzed by reduced compounds of sulfur. The test is not specific, since many other compounds have similar catalytic effects. Thus test results should be interpreted with caution because of interference from a variety of materials.
Energy conservation opportunities in municipal water and wastewater systems
Authors: Lystra Donald W. , Singhal Ashok K. , Loud Philip N.
Published: February 2018

Municipal water and wastewater systems have been shown to be the largest energy consumers in local governments. By studying unit processes at four utilities in the state of Michigan, the authors were able to pinpoint several areas in which sizable energy savings could be realized.
Conduct and uses of jar tests
Authors: Hudson Herbert E. , Wagner E.G.
Published: February 2018

If procedures that simulate treatment plant conditions are followed, jar testing can produce important information quickly and economically, and the data are directly applicable to plant design, modification, and operation. The procedure offers greater flexibility and economy than the traditional pilot plant test for pretreatment. It has shown excellent scale‐up correlations with plant operating records.
A regional response to water supply emergencies
Authors: Hooker Donald
Published: February 2018

In response to increased demand and previous drought conditions, area utilities teamed together to create a formal agreement for responding to area water shortages. Although most periods of low water supply are weather‐related, the agreement also covers shortages created by such occurrences as distribution system failures.
State initiatives for regionalization
Authors: Okun Daniel A.
Published: February 2018

Regionalization of water management offers many advantages over the present highly fragmented organizational structure that characterizes the water industry in the United States. Economies and efficiencies of scale are particularly attractive. Local government is loath to initiate regional arrangements because of the threat to local sovereignty. Federal initiatives are suspect and generally successful only when accompanied by federal dollars, which may cost more than they are worth. Accordingly, state government may be in the best position to stimulate the creation of regional institutions. Examples of such initiatives, both successful and unsuccessful, are discussed.
Carcinogenesis of synthetic organic chemicals in drinking water
Authors: Kraybill Herman F.
Published: February 2018

Of the total contaminants in the water supply on a worldwide basis, 2221 organic chemicals have been identified, and of these, about 765 are in drinking water. Of this total group of organic chemicals, 43 are recognized or suspected carcinogens, 56 are mutagenic contaminants, and 18 are carcinogenic promoters. Cancer risk factors are estimated for five organic contaminants. Five experimental approaches are recommended to elucidate the risk of cancer from organic biorefactories.
Evaluating adsorbent filter performance for enteric virus concentrations in tap water
Authors: Sobsey Mark D. , Moore Rebecca S. , Glass J. Steven
Published: February 2018

Under varying operating conditions, the performance limits of an electropositive adsorbent filter were equivalent to those of a conventional electronegative adsorbent filter. Performance limits were determined with respect to adsorption flow rate (hydraulic flux), tap water process volume (hydraulic load), stability of adsorbed virus during storage, and ability to concentrate several different enteric viruses.
Reactivity of halogens with aqueous micropollutants: a mechanism for the formation of trihalomethanes
Authors: Dore M. , Merlet N. , De Laat J. , Goichon J.
Published: February 2018

A study of some recognized extremes in precursor reactivities, such as occur with methylketones or metapolyhydroxybenzenes, indicates the variability of physical and chemical reactions in their effects on haloform yields. Comparison of the reactivities of chlorine, bromine, and iodine suggests that an iodoform test can give global determinations of haloform reaction precursors.
Economic analysis of water main breaks
Authors: Walski Thomas M. , Pelliccia Anthony
Published: February 2018

The cost of water main breaks can represent a significant portion of a distribution system's maintenance costs. Although qualitative guidance is available on why pipes break and when they should be replaced, there are no universal quantitative rules for when to replace pipe. This paper gives a simple method for determining which pipes need to be replaced, based on the history of recorded breaks.
Considering sludge production in the selection of coagulants
Authors: James Carol Ruth , O'Melia Charles R.
Published: February 2018

A combination of alum and a high‐molecular‐weight, weakly charged cationic polymer produced the most effective removals of TOC and turbidity, reduced the volume of sludge produced when compared with alum alone, and accomplished these objectives at reduced costs.
Investigating potential water contamination by petroleum‐asphalt coatings in ductile‐iron pipe
Authors: Miller Herbert C. , Barrett William J. , James Ruby H.
Published: February 2018

Experimental evidence designed to simulate a “worst‐case” scenario suggests that no significant contribution of polynuclear aromatic hydrocarbons (PAH) to piped water should be expected from a relatively freshly seal‐coated pipe.
Using pump curves and valving techniques for efficient pumping
Authors: Hilsdon Charles W.
Published: February 2018

Pump selection in single‐ and multiple‐pump installations involves the development of accurate system head curves, which represent the actual conditions under which the pump will operate. Variables in pump selection include the impeller diameter, pump speed, and parallel‐ and series‐pump operation. Regulation of capacity can also be affected by certain valving techniques.
Low‐dosage high‐rate direct filtration
Authors: Wagner E.G. , Hudson H.E.
Published: February 2018

Direct filtration of public water supplies is an increasingly acceptable treatment option. Compared with conventional treatment, direct filtration has lowered capital costs, reduced space requirements, and decreased sludge quantities. Moreover, the direct filtration process may offer large reductions in coagulant dosages and costs. The authors’ review of their experience with the use of low‐dosage chemical treatment in preparation for direct filtration, as well as a literature review, provides evidence that the potential for low‐dosage treatment may be widespread.
Viruses in a community water supply associated with an outbreak of gastroenteritis and infectious hepatitis
Authors: Hejkal T.W. , Keswick B. , LaBelle R.L. , Gerba C.P. , Sanchez Y. , Dreesman G. , Hafkin B. , Melnick J.L.
Published: February 2018

When a waterborne outbreak of gastroenteritis and hepatitis occurred in Georgetown, Texas, in June 1980, human enteric viruses were isolated from two of the city's wells and from a 720‐L sample of the city's potable water. Hepatitis A virus was also detected in the sewage and in one well‐water sample. The demonstration of viruses in the groundwater supply during a disease outbreak has implications for other communities that rely on groundwater and practice little or no water treatment.
The abuse of science in public policy
Authors: Havender William R.
Published: February 2018

The abuses of science by legislation and the unfounded conclusions which are sometimes reached are discussed. Cited are three examples of wrong conclusions reached by various scientists, including the Love Canal study which claimed that medical problems of residents were due to exposure to toxic wastes, a study which stated that lymphoma was caused by nitrites in foods, and an epidemiological study which led to an FDA ban on saccharin‐containing food products. In each of these cases, other studies have proved the original accounts either false or misleading due to the scientific methods used or the lack of pertinent information. To avoid such occurrences in the future, the author suggests that the current laws which direct science need to be changed.
Analysis of water supply costs in the Washington [D.C.] area
Authors: Clark Robert M. , Gillean James I. , Goodrich James A.
Published: February 2018

The crucial issue of assuring an adequate potable water supply to the Washington, D.C., Metropolitan Area (WMA) has been a subject of intense debate for at least 20 years and of concern for many more. Increased reliance on the Potomac River, which is subject to extreme fluctuations in flow, prompted this study of the most cost‐effective ways to ensure an extension of water supply availability.
Counterpoint – Crisis‐Ridden Water Systems Should Go Public
Authors: Sharpe William E.
Published: February 2018

Privatization of water systems is not a cure‐all for crisis‐ridden utilities as suggested in the February 1982 “Viewpoint.” What profit‐oriented company would be likely to purchase a deteriorating system, and what effect would such a purchase have on consumers? William E. Sharpe, water resources specialist with the Institute for Research on Land and Water Resources at Pennsylvania State University, University Park, Pa., argues that public ownership is more equitable for all consumers than private ownership.
Performance variability, ranking, and selection analysis of membrane filters for enumerating coliform bacteria in river water
Authors: Lorenz Richard C. , Hsu Jason C. , Tuovinen Olli H.
Published: February 2018

Seven different kinds of membrane filters were evaluated for the enumeration of fecal coliforms in water samples from three rivers. Analysis of variance of filter performance indicated significant interaction between the filter and the river water. The ranking and selection of filters was performed by using two different statistical procedures. In this paper a newly developed statistical method—MCB (Multiple Comparisons with the Best)—is introduced. None of the filters examined were found to be perfectly suitable for enumeration of fecal coliforms or total coliforms, but based on relative merits, two filters were outstanding.
Long‐term trends in nitrate concentration in Iowa water supplies
Authors: McDonald Donald B. , Splinter Roger C.
Published: February 2018

Long‐term water quality studies of surface waters and groundwaters in Iowa have shown increases in nitrate concentrations in surface supplies and shallow wells. Nitrate concentrations in deeper wells have remained low and have exhibited no appreciable increases since 1950. The application of nitrogenous fertilizers to agricultural land appears to be the primary source of nitrates in water supplies.
Analyzing transportation‐related hazardous material spills in New England
Authors: Crusberg Theodore C. , Smith David L.
Published: February 2018

This study shows that transportation‐related hazardous material spills are common in New England, and surface water supplies should be protected from this problem. A statistical analysis of reports made to the US Environmental Protection Agency in Region I (Lexington, Mass.) indicates that under‐reporting of such spills may be a serious hindrance to new legislation that would aid in protecting supplies of potable water. However, the more serious incidents were more likely to be reported to the federal government.
Stress differs from distress
Authors: Romanos William J. , Wise John C. , Sewards Joseph M.
Published: February 2018

Stress can seriously affect job performance throughout an organization. The first step in relieving stress is understanding how the human body copes with it physiologically and why stress so often is undetected until serious illness strikes. Managers should be aware of recently developed skills that can relieve stress and thus improve operational efficiency.
Analyzing asbestos fibers in water by means of transmission electron microscopy
Authors: Boatman Edwin S.
Published: February 2018

Analysis of asbestos in water is costly, requiring special facilities, an extensive series of manipulations, and excellent laboratory technique. Data that have been gathered over the past eight years indicate that a method involving transmission electron microscopy is the most appropriate of the microscopic methods used to detect and identify asbestos fibers. This paper offers an outline of the procedures used for the analysis of asbestos in drinking water.
New approaches to measuring total bacterial populations in water supplies
Authors: Herson Diane S. , Baker Katherine H.
Published: February 2018

Direct counts of stained bacterial cells were compared with counts obtained from standard plating techniques. The method used by the authors combined acridine orange staining with 2‐(p‐iodophenyl)‐3‐(p‐nitrophenyl)‐5‐phenyl‐tetrazolium chloride reduction. To overcome the interference of a membrane filter's pores with the identification of stained cells, the authors used a gel‐stripping technique to transfer the bacterial cells from membrane filters to a gelatin matrix before counts were made. The method will supplement standard plate counts by determining metabolically active bacteria in a water sample within four hours.
Inspecting, painting, and maintaining steel water tanks
Authors: Harper William B.
Published: February 2018

Water tanks require periodic inspection for signs of deteriorating paint coatings and regular maintenance of exterior and interior finishes. Dark exterior colors appear to degenerate faster than lighter colors and also cause more problems with interior coatings because of solar heat absorption. Methods of inspection are described as are procedures for repainting and recoating tanks.
Aqueous odor and taste threshold values of industrial chemicals
Authors: Alexander H.C. , McCarty W.M. , Bartlett E.A. , Syverud A.N.
Published: February 2018

Data have been generated on odor thresholds for 63 industrial chemicals; 46 of these also have been evaluated for taste threshold. A standard odor comparison substance, 1‐butanol, was used to compare the panel's values with values reported in the literature. The lowest odor threshold observed was 0.0008 mg/L for number 2 fuel oil. Naphtha gave the lowest taste threshold (0.02 mg/L). The effect of water temperature (60° C to 20° C) on odor threshold was tested for three chemicals. The odor thresholds measured at 60° C should be applicable at ambient temperature.
Evaluating potential health risks of consuming reused water
Authors: Neal Robert A.
Published: February 2018

The possible adverse health effects caused by human consumption of reused water are surveyed, and suggestions for laboratory animal tests to evaluate chemical constituents of the water are outlined. Such analyses are necessary before water treatment processes can be adjusted to accommodate reused water and monitoring procedures can be established to assure its safety.
The relationship of minerals commonly found in drinking water to atherosclerosis and hypertension in pigeons
Authors: Revis Nathaniel W. , Schmoyer Richard L. , Bull Richard
Published: February 2018

The authors have studied the effects of Ca, Cd, Pb, and Mg in drinking water on cardiovascular disease in white Carneau pigeons. These effects are expressed in terms of blood pressure and the presence and severity of atherosclerosis in pigeons from each of 16 experimental groups. The presence of Pb or Cd in drinking water significantly increased both blood pressure and the number and size of aortic atherosclerotic plaques. However, the presence of Ca significantly reduced the effects of Cd or Pb on blood pressure and on the number and size of aortic plaques.
Comparative inactivation of six enteroviruses by ozone
Authors: Roy D. , Englebrecht R.S. , Chian E.S.K.
Published: February 2018

Inactivation of six enteroviruses by ozone was determined by using a continuous flow, completely mixed reactor under controlled laboratory conditions. The relative resistance of these viruses to ozone was found to be, in descending order: poliovirus 2, echovirus 1, poliovirus 1, coxsackievirus B5, echovirus 5, coxsackievirus A9. The resistance of poliovirus 2 was approximately forty times that of coxsackievirus A9. The inactivation of enteroviruses by ozone was observed to be influenced by a change in temperature or pH.
Using water distribution system models
Authors: Walski Thomas M.
Published: February 2018

Selecting a numerical method for modeling a water distribution system is only the first step in obtaining accurate results. This article offers some practical suggestions for using water distribution models including selection of the program, calibration of the model, preparation of working maps of the system, and running the model.
The Latin American approach to improving water supplies
Authors: Wagner E. Glenn
Published: February 2018

The cost of supplying water for small cities and towns in Latin America is much less than in the United States because of regional administration, methods of financing, and simplified design of treatment plants. The aspects that are most adaptable to other developing countries and to the United States are discussed, with Brazil used as an example.
Ferric chloride and alum as single and dual coagulants
Authors: Johnson Patrick N. , Amirtharajah A.
Published: February 2018

A design‐and‐operation diagram for Fe(III) coagulation has been developed by using empirical work and information in the literature about coagulation. This diagram is compared with a previously developed design‐and‐operation diagram for alum coagulation. Empirical work has shown that combining alum and ferric chloride as dual coagulants does not result in a more effective coagulant.
Surviving the Johnstown, Pa., flood
Authors: Rosenthal Meyer
Published: February 2018

The devastating 1977 flood in Johnstown, Pa., created havoc with the city's water system. From this experience, some recommendations emerged that could enable a water utility to respond more quickly to the need for supplying safe, potable water. Being prepared before sudden disaster strikes obviates many potential problems and increases ability to cope with inevitable damage.
Energy efficiency through pipe design
Authors: Walski Thomas M.
Published: February 2018

Selecting pipe sizes in the course of developing planning studies usually involves applying some rule of thumb based on peak flow. Such rules do not account for the cost of energy, which can be significant. Some simple rules that incorporate energy cost factors for selecting optimal pipe sizes are presented.
Fundamental characteristics of water treatment plant sludges
Authors: Knocke William R. , Wakeland Douglas L.
Published: February 2018

Waste sludge samples obtained from several water treatment facilities in the Commonwealth of Virginia were used in laboratory‐scale dewatering studies that emphasized a review of floc microproperties, such as size distribution, shape, and density, and their impact on sludge filtration rates. Methods applicable to the measurement of floc size, density, shear strength, and water content were evaluated. The use of the Atterberg liquid limit test for providing data related to shear strength considerations was also experimentally reviewed.
Viewpoint – Water Supply and the New Federalism: A Foggy Glimpse Into the Past and Future
Authors: Gaston John
Published: February 2018

This month's “Viewpoint” discusses changes which the water utility industry will have to make if the new federalism takes hold. These changes include destroying the notion that water is an invisible, cheap commodity, reinforcing and implementing measures to protect source water quality, and developing new and better measurement techniques for identifying contaminants.
Effect of sampling variables on recovery of volatile organics in water
Authors: Ho James S.‐Y.
Published: February 2018

A laboratory system was set up to study the effect of sampling variables on the recovery of volatile organics in water by using a peristaltic‐pump sampler. A statistical 23 factorial experimental design was used to study the relative importance of three variables: transport‐line material, pumping rate, and the concentration of organic compounds. Other variables, such as sample lift and sample preservation, were also studied. The transport‐line material had a statistically significant effect on the recovery of all compounds studied. The pumping rate, the concentration level, and the sample lift affected the recovery of those volatile organics with Henry's law constants greater than 10 ‐2 atm·m3/mol. The preservation study showed that when sample bottles were only partially filled, they had to be preserved at 4° C or less so that they could be stored for at least two days without significant losses of the organic compounds.
Tailoring benefits to attract effective managers
Authors: Robertson Thomas T. , Harrold Steven A.
Published: February 2018

A properly structured benefit program that allows an employee options can help achieve the objectives of employers in attracting and retaining a desirable management and professional staff.
Viewpoint – A Venture Into the Past and Future
Authors: Wolman Abel
Published: February 2018

In this month's “Viewpoint,” Abel Wolman discusses his views on managing wastewaters and protecting drinking water. Past assessments and improvements in dealing with infectious diseases and organic and inorganic chemicals in water are reviewed. Wolman concludes that both the chemical and wastewater and water industries must take more responsibility for determining and controlling mutagenic and carcinogenic compounds. Furthermore, public opinion should also be given more serious consideration.
Base‐Extra Capacity Water Rate Design Questioned
Authors: Dimeo Joe , F R.
Published: February 2018

Reader Joe Dimeo writes with the following criticisms of AWWA's Manual M1 and “Base‐Extra Capacity Water Rate Design” (JOURNAL AWWA September 1983) by R.F. Banker: no rationale is given for allocating costs to base (commodity) or extra capacity (demand) and the considerable variation between the two systems; measuring extra capacity on an individual class basis is beyond the ability of almost every water district in the US; nothing tangible supports the assumption that extra capacity is contributed primarily by users in the first 15,000 gal/month category; though the manual recognizes the wide variation in water usage habits within each class and therefore the unavoidable discrimination in charges to individuals, it blandly dismisses this problem by saying that this issue is too complex to deal with; and the manual makes a weak case for assigning the balance of cost‐of‐service and unit costs on an individual basis in the actual design and development of water rates. R.F. Banker responds to each of Dimeo's points, and concludes that careful study of the new Water Rates Manual M1, including recognition of the intent and limitations of such a manual as set forth in the introduction, will provide the user with a basic understanding of the principles of rate‐making.
Transformations of Tetrachloroethene and Trichloroethene in Microcosms and Groundwater
Authors: Parsons Frances , Wood Paul R. , DeMarco Jack
Published: February 2018

Cis‐ and trans‐l,2‐dichloroethene were found in well water at a site contaminated with trichloroethene from a leaking storage tank, although neither compound was used in the vicinity nor was present as an impurity in the trichloroethene in the storage tank. The use of tetrachloroethene and trichloroethene in dry cleaning and metal refinishing plants is widespread. Several chloroethene compounds that are found in southern Florida groundwater may have been formed from these solvents via microbial metabolism in the groundwater environment. In this study, depletion of tetrachloroethene and appearance of cis‐ and trans‐l,2‐dichloroethene and chloroethene were observed following incubation of tetrachloroethene in microcosms containing muck from the aquifer recharge basin.
The Effects of Acid Precipitation Runoff on Source Water Quality
Authors: Leibfried Robert T. , Sharpe William E. , DeWalle David R.
Published: February 2018

The quality of water in two small streams that provide supplies to the water systems of Jennerstown and Boalsburg, Pa., was monitored during episodes of acid runoff in February 1981 (Card Machine Run) and March 1983 (Galbraith Gap Run). Changes in pH, in the concentration of aluminum, and in the the Ryznar Stability Index were determined. The magnitude and potential importance of these changes are discussed.
Field Monitoring of Chrysotile Asbestos in California Waters
Authors: Hayward Steven B.
Published: February 2018

The extent of asbestos contamination in sources of drinking water in the state of California is being monitored. Preliminary results show substantial fiber concentrations in surface waters whose watersheds include serpentine rock. These concentrations exhibit seasonal variations, with the largest concentrations occurring during or just following heavy rains in the watershed. Some of the concentrations were the highest measured anywhere in the world. Asbestos was also found in groundwater taken from wells that are recharged through serpentine rock. Water treatment was found to have widely varying success in the removal of asbestos fibers. In one case reduction by a factor of 5 × 104 was observed as a result of conventional coagulation‐filtration. Although sparse, the data on treatment suggest that the percentage removal of fibers depends on the initial concentration.
Controlling Corrosion by Controlling Bacterial Growth
Authors: Victoreen Hugo T.
Published: February 2018

Three experiments were conducted with a section of tuberculated cast‐iron main moved from the field to the laboratory for study. Influent (a blend of chlorine‐free waters from the distribution system) was treated with chlorine, erythromycin, or cyanide. Each antibiotic reduced total iron and turbidity, as well as total bacteria.
The Removal of Organic Halide Precursors by Preozonation and Alum Coagulation
Authors: Reckhow David A. , Singer Philip C.
Published: February 2018

An increased awareness of potentially carcinogenic micropollutants in US drinking waters has led to a reevaluation of several well‐established treatment techniques. The major focus of this concern has been on the recently recognized hazards of chlorination—the formation of both trihalomethanes and total organic halides. Coagulation has also been the subject of renewed investigation because of its ability to remove halogenated organic precursors. This article discusses the effects of preozonation and alum coagulation, both separately and in combination, on the removal of organic halide precursors.
Techniques for Protecting Groundwater Quality
Authors: Geraghty James J.
Published: February 2018

The ideal goal of complete protection of underground drinking water sources is probably economically and physically infeasible. Relatively few of the nation's drinking water wells have been contaminated, and the most serious instances of contamination can be controlled with proven techniques such as impounding plumes of contamination behind barrier walls or draining and pumping the plume. In the long term, the public should be made aware of the consequences of using certain common household, industrial, and agricultural products that can ultimately seep into drinking water aquifers.
Inorganic Chloramines as Drinking Water Disinfectants: A Review
Authors: Wolfe Roy L. , Ward N. Robert , Olson Betty H.
Published: February 2018

Although chloramines have been used to disinfect drinking water in the United States for more than 60 years, interest in these disinfectants has recently increased with the discovery that much lower levels of halogenated organics are produced during chloramination than during chlorination. Considerable controversy exists, however, regarding the effectiveness of chloramines as microbicidal agents and their possible effects on human health. This article reviews the advantages and disadvantages of the use of chloramines in disinfection, including their chemical properties; their effectiveness against bacteria, viruses, and protozoa; and the toxic effects they produce in humans and wildlife. The use of laboratory findings for predicting the efficiency of chloramines in the field is also addressed.
Groundwater Goof
Authors: Lund L.
Published: February 2018

In response to “Proposed Groundwater‐Management Pact Gets Votes of Approval” (Journal AWWA February 1984), this author clarifies figures related to Owens Valley, California water supplies and water use.
Viewpoint – A Perspective on the Control of Toxics
Authors: Lynch William O.
Published: February 2018

AWWA President William O. Lynch delivered the following address Jan. 24, 1984, at the National Conference on Toxics in Surf ace and Ground Waters, held in Philadelphia, Pa.
Regional Authorities Support Small Water Systems in the Americas
Authors: Donaldson David
Published: February 2018

This article describes the progressive steps that water and sanitation authorities in Latin America have carried out, beginning in the 1950s and extending to the present, to implement the goal of providing these basic services for all. As water sector programs are realized for smaller villages and dispersed populations, regional authorities are integrating their institutional activities to support such programs. This institutional experience in providing public water supplies for the Americas could be transferred to guide water projects in other regions of the world, as countries in Asia and Africa extend these services to smaller communities.
How Safe Are Organic Polymers in Water Treatment?
Authors: Mallevialle Joel , Bruchet Auguste , Fiessinger Francois
Published: February 2018

The advantages of organic polymers, or polyelectrolytes, in water treatment are many. But what is the fate of a polymer subjected to typical treatment processes? What by‐products are formed by ozonation and chlorination? Are there manufacturing impurities accompanying the polymers? What are the toxic and mutagenic effects of these impurities and by‐products? An anionic organic polymer commonly used in France was analyzed by several methods. It was found to be generally acceptable for drinking water standards in the United States and France. But the by‐products and impurities that were detected require more research to determine their potential health effects and demonstrate the need for adequate quality controls during manufacture of the polymer.
Computer Modeling in Water System Planning and Design
Authors: Harris Ronald U.
Published: February 2018

An overview of the methods of modeling water systems to improve and expand distribution facilities is followed by case studies of applications in Charlottesville, Va., Decatur, Ala., and Opelika, Ala. As computer hardware becomes less expensive and software becomes increasingly available, these techniques are within the reach of small systems as well as large systems.
A Computer‐Assisted Water System Analysis and Design for Charleston, S.C.
Authors: Topping Raymond E. , Puccia Robert J.
Published: February 2018

A computer model was developed and used to analyze all components of the Charleston, S.C., water distribution system in anticipation of improving the system to meet future demands. After limitations and deficiencies were identified, cost‐effective improvements to piping, storage facilities, service pumps, and booster pumps were recommended. An improved operations program, which included a power management plan that resulted in substantial savings in energy costs, was also determined with the computer model.
Computing Water System Development Charges
Authors: Barden Drew S. , Stepp Russell J.
Published: February 2018

This article illustrates how the base‐extra capacity cost allocation method can be used to compute a schedule of water system development charges for new customers. The goal is to achieve a more equitable recovery of capital costs from new connections that are made to an existing water system.
Was NAS Drinking Water Committee Report Ignored by the USEPA?
Authors: Suffet I. H. (Mel) , Symons James M.
Published: February 2018

In response to James M. Symon's article “A History of the Attempted Federal Regulation Requiring GAC Adsorption for Water Treatment” (Journal AWWA, August 1984), Suffet questions why the report on activated carbon adsorption by the Subcommittee on Adsorption of the National Research Council's Safe Drinking Water Committee seems to have had little effect on the federal regulatory process. Symons replies that although the committee's recommendations were useful, they were outweighed by other factors during the EPA's decision‐making process.
Pretreatment Preferred Over Outlandish Chlorine Doses
Authors: White George Clifford , Sacks Richard S.
Published: February 2018

In response to “Ann Arbor Controls Trihalomethanes” by Richard Sacks (Journal AWWA, July 1984), White disputes the practice of using chlorine beyond the breakpoint and then adding more ammonia. He suggests use of a 15‐minute chlorine demand surrogate parameter for raw water quality as an adjunct to total trihalomethane formation potential. Sacks replies that the article presented combined chlorination (i.e., adding ammonia to form chloramines) as an economical method of compliance for utilities that cannot meet the THM regulation.
An Overview of Water Treatment Practices in the United States
Authors: Stacha John H. , Pontius Frederick W.
Published: February 2018

Environmental and regulatory changes in the United States have required commensurate changes in the drinking water industry. This history of drinking water practices and treatment technologies recounts the progress of the industry over the past century and summarizes the treatment methodologies in common use today. New developments that are coming into use to address new concerns are also discussed.
Achieving Biologically Stable Drinking Water
Authors: Rittmann Bruce E. , Snoeyink Vernon L.
Published: February 2018

Biologically stable water does not promote the growth of microorganisms during its distribution. This article combines microbiological theory and European practice to demonstrate how biological processes within a water treatment plant can remove the organic and inorganic substrates that cause or contribute to biological instability. Theory and practice indicate that ammonium and manganese ions and biodegradable organic compounds can be removed by attached‐growth processes such as fixed bed, fluidized bed, and rapid sand filters. Low temperatures do not preclude good treatment. A quantitative kinetic model, which accurately describes field results, provides a sound basis for successful design and operation of biological water treatment processes. Following a biological process with conventional processes is recommended to provide multiple barriers against the escape of microorganisms into the finished water.
Estimating Mean Coliform Densities of Water Distribution Systems
Authors: Pipes Wesley O. , Christian Robert R.
Published: February 2018

Current drinking water regulations set a limit on the average number of coliforms allowed in samples that are collected during distribution system monitoring. This article presents evidence that the average number of coliforms in monitoring samples is a poor estimate of the mean coliform density of the distribution system. The evidence includes variance in coliform counts, data truncation caused by limitations of the examination methods, changes in coliform densities during transport of the samples to the laboratory, and false results. A regulation based on the fraction of monitoring samples with coliform densities greater than a preselected limit may be a feasible alternative to the current microbiological maximum contaminant level.
Pilot‐Plant Studies of Slow‐Rate Filtration
Authors: Fox Kim R. , Miltner Richard J. , Logsdon Gary S. , Dicks Douglas L. , Drolet Larry F.
Published: February 2018

Alternatives to conventional water filtration plants, which use coagulation, flocculation, sedimentation, and rapid filtration, may be appropriate for some small utilities. One such alternative is slow‐rate filtration. This article describes pilot‐plant studies that were undertaken to evaluate slow‐rate filtration for the removal of particulates, total coliforms, standard plate count bacteria, and organics (total organic carbon and trihalomethane formation potential). Two pilot‐scale filtration systems were used: a slow sand filter, operated for 800 days, and a second slow sand filter operated in parallel with a slow‐rate filter containing granular activated carbon, operated for 200 days. Results are presented for both systems.
Denver's Seven Decades of Experience With Chloramination
Authors: Dice Jack C.
Published: February 2018

The Denver (Colo.) Water Department's long‐term experience with the use of chloramines as a disinfectant can serve as a guide to those who have changed, or are considering a change, to this method. Recommendations include a high‐quality source of raw water and continuous vigilance in monitoring and maintaining the system.
Surrogate Parameters for Monitoring Organic Matter and THM Precursors
Authors: Edzwald James K. , Becker William C. , Wattier Kevin L.
Published: February 2018

UV absorbance at 254 nm is an excellent surrogate parameter for estimating the raw water concentrations of organic carbon (NPTOC—nonpurgeable total organic carbon) and THM precursors (TTHMFP—total trihalomethane formation potential) in the Grasse River (highly colored water) and the Glenmore Reservoir (protected, upland source). The raw water surrogate equations developed from the Grasse River data were tested successfully on other waters. Direct filtration pilot‐plant data demonstrated that UV can be used to monitor pilot‐plant performance for removals of NPTOC and THM precursors. For two plants studied, UV was an excellent predictor of plant performance for removals of NPTOC and THM precursors. Instantaneous TTHMs of the finished waters can be predicted from raw water UV, finished water pH, chlorine consumption, and temperature data. Particular attention should be given to the selection of sampling locations and to the sample‐handling conditions.
Organic Halogen Measurements: Current Uses and Future Prospects
Authors: Stevens Alan A. , Dressman Ronald C. , Sorrell R. Kent , Brass Herbert J.
Published: February 2018

Currently, the most popular method of analyzing total organic halide in water involves carbon adsorption, oxidative combustion, and measurement of the hydrogen halide by microcoulometry. Total organic halide can be used as an indicator of water quality, providing a direct measure of disinfection by‐product formation and, in some circumstances, a surrogate measure of individual organic pollutants. An important application of organic halide measurements is in unit process design, control, and monitoring. Each potential application, however, must be carefully assessed to determine the usefulness of organic halide measurements.
Removal by Coagulation of Trace Organics From Mississippi River Water
Authors: Semmens M.J. , Ayers Kenneth
Published: February 2018

In this study alum and ferric sulfate were evaluated for their effectiveness in removing four low‐molecular‐weight organic compounds—C14‐labeled octanoic acid, salicylic acid, phenol, and benzoic acid—from Mississippi River water and from water samples free of natural organic matter. Removal of these model organic compounds ranged between 3 and 20 percent, which is similar to the removals observed for the <1K fraction of natural organic matter. Solution pH affected the removal of the aromatic compounds but not of octanoic acid. Except for benzoic acid, all the model compounds were removed better in the absence of natural organics. Removal was found to be relatively insensitive to coagulant dosage.
The Amsterdam Water Supply
Authors: van der Veen Cornelis
Published: February 2018

The drinking water supply and treatment system in Amsterdam, dating from the mid‐1850s, takes advantage of the new and the old. Supplies are drawn from natural catchment areas in sand dunes, from the Rhine River, and from surface lakes as well as from groundwater. The dune‐water source is recharged with pretreated surface water before it is treated to potable quality for distribution. Industrial water, which is not of drinking water quality, is delivered separately to steel mills, paper mills, and an oil refinery. The pollution of the Rhine River concerns water suppliers in cities, such as Amsterdam, that are located across international boundaries from the sources of pollution. The author gives an overview of the sources of water supply, the treatment processes, and the distribution system that serve the capital city of the Netherlands.
Water Resources in Thailand's Resettled Villages
Authors: Perry James A. , Dixon Robert K.
Published: February 2018

An interdisciplinary survey team, composed of specialists in water quality, silviculture, agricultural economy, agricultural engineering, and anthropology, undertook a survey of two differing provinces in Thailand to assess the successes and shortcomings of resettlement programs. The authors describe the interdisciplinary approach and the findings of the survey team regarding water resources and management. Improved local participation in such projects is suggested to increase the likelihood of long‐term success of the relocation programs.
The Current Status of Denver's Potable Water Reuse Project
Authors: Lauer William C. , Rogers Stephen E. , Ray Jean M.
Published: February 2018

The feasibility of directly treating processed wastewater plant effluent to potable quality is being tested in Denver, Colo., with a full‐scale, 1‐mgd (3.8‐ML/d) demonstration plant. The complexity of putting the system into operation and the results to date are described, along with an outline of the plans for health effects research, economic studies, and programs to gain public acceptance of direct reuse. This project is expected to provide the information necessary to evaluate the feasibility of direct reuse, especially for cities located in water‐scarce areas where development of more conventional water resources is becoming increasingly costly, both in terms of the environment and in capital investments.
Roundtable – Trends in Ozonation
Authors: Sontheimer Heinrich , Fiessinger François , Rice Rip G. , Varas Alexander J. , LePage Wilfred , Prendiville Paul W. , Singer Philip C.
Published: February 2018

This discussion took place June 25, 1985, during AWWA's annual conference in Washington, D. C. Philip C. Singer, professor in the department of environmental sciences and engineering. University of North Carolina, Chapel Hill, moderated the panel and also assisted with editing the transcript. Other participants were: François Fiessinger, director of the central laboratory of the Lyonnaise des Eaux, Le Pecq, France; Wilfred LePage, superintendent of water treatment for the city of Monroe, Mich.; Paul W. Prendiville, senior vice‐president of Camp Dresser & McKee, Boston, Mass.; Rip G. Rice, president of Rip G. Rice Inc., Ashton, Md.; Heinrich Sontheimer, professor at the University of Karlsruhe, West Germany; and Alexander J. Varas, associate with Hazen and Sawyer, New York City.
Author Edits Theme Introduction
Authors: Myers Anthony G.
Published: February 2018

The author of this letter corrects statements in the theme introduction, “Groundwater,” (Journal AWWA, May, 1985). According to the author, a sentence reading, “Among the methods of removing these elements are...lime softening, which may cause corrosion problems; and ion exchange, which produces a large volume of sludge,” should be reversed to say: “... lime softening, which produces a large volume of sludge; and ion exchange, which may cause corrosion problems.” Also, the author believes that a sentence stating that:”.. investigators at the University of Illinois found promise in regenerating and reusing the resin” should read:”...investigators at the University of Illinois found promise in reusing the spent brine to regenerate the resin.” In response, the editor states that the statements in the theme introduction are essentially correct as they originally appeared, with the possible exception of the use of the word “sludge” in lieu of “brine.”