bluuebunny/crossref_metadata_2025 huggingface dataset:
The Evolution of Water Demand Forecasting
Authors: DeKay C. Frederick
Published: February 2018

Over the last 75 years, the Seattle (Wash.) Water Department's demand forecasts have evolved from intuitive assessments to sophisticated computer models that prepare geographically disaggregated, long‐term forecasts for planning facilities and short‐term forecasts by customer class for rate‐making and financial planning. A chronology of this evolution, a discussion of the issues that spawned it, and an analysis of the data bases that made it possible illustrate the lessons learned for water systems following a similar path of developing forecasting models.
Pitting in Copper Water Tubing
Authors: Rossum John R.
Published: February 2018

Investigation of leaks in copper water tubing led to evidence that internal pitting corrosion of copper is the result of failure to thoroughly flush household plumbing rather than a result of corrosive water or defective material.
Emerging Trends in Infrastructure Financing
Authors: Bodde David L.
Published: February 2018

Constrained budgets at the federal level suggest that state and local governments will have to assume a larger share of infrastructure spending. This has been true historically for water supply, for which federal funding has never played a dominant role, and is becoming increasingly likely for wastewater treatment as well. The limited federal assistance that might become available could take two forms: (1) targeted aid to economically distressed areas, and (2) unrestricted aid through block grants and revolving loan funds. Because congressional consideration of these matters remains incomplete, water supply and wastewater treatment managers have an opportunity to contribute to the legislative process.
Prediction of Organic Chemical Permeation Through PVC Pipe
Authors: Berens Alan R.
Published: February 2018

The transport properties of representative organic solvents at a wide range of concentrations in polyvinylchloride (PVC) powders, films, and sheets have been studied by gravimetric sorption methods to assess the possibility of organic pollutants permeating through underground PVC pipe. The rate of penetration changes by many orders of magnitude as the concentration, or activity, of solvent in the environment is varied. Softening and significant permeation of PVC pipe seems possible only in the presence of nearly undiluted solvents or swelling agents for PVC. At lower activities, which still correspond to unusually high levels of environmental pollution, solvent transport follows ideal Fickian diffusion kinetics. Thus reliable extrapolations to pipe walls are possible from laboratory data on PVC powders and films. The calculated permeation rates are virtually zero for many centuries, indicating that rigid PVC pipe is an effective barrier against permeation of environmental pollutants.
Effects of Cationic Polyelectrolytes on the Removal of Suspended Particulates During Direct Filtration
Authors: Tanaka Theodore S. , Pirbazari Massoud
Published: February 2018

This research investigated the important parameters influencing the degree of particulate removal from low turbidity water in a configuration that included rapid mixing followed by filtration. The varied parameters were rapid‐mixing velocity gradient, cationic polyelectrolyte type, and polyelectrolyte dosage. The cationic polyelectrolytes were characterized for molecular weight by membrane osmometry, light scattering, and high performance liquid chromatography. The filtration kinetics variables, including maximum depth‐averaged singlecollector efficiency and specific deposit, were used to characterize the efficiency of particulate removal for each of 72 filter runs. Statistical analyses demonstrated that the choice of polyelectrolyte was the only significant factor. Additionally, volume size distribution analyses of particle count data from in‐depth samples in the filter demonstrated that the polyelectrolyte configuration may be critical for adsorption of polyelectrolytes to particulates and media in filtration.
Waterborne Viral Gastroenteritis
Authors: Williams Fred P. , Akin Elmer W.
Published: February 2018

In studying the causes of human gastroenteritis, electron microscopy and related techniques have led to the identification of new viral agents that had previously escaped detection by routine cell culture procedures. Efforts to characterize and study these agents further are currently being made by researchers in many areas of the world. Two of the best‐known agents, rotavirus and Norwalk virus, have been implicated in waterborne outbreaks of this illness. Another virus, the Snow Mountain agent, was first identified from the investigation of one waterborne gastroenteritis outbreak.
Legionella Contamination of a Preoperational Treatment Plant
Authors: Voss Lance , Button Kenneth S. , Lorenz Richard C. , Tuovinen Olli H.
Published: February 2018

A study of the distribution of Legionella in a newly constructed water treatment facility found Legionella pneumophila (serogroup 1) in both hot‐ and cold‐water lines. The contamination was monitored by bacterial enumeration of samples collected from various sites in the building and from disassembled plumbing fixtures. Repeated flushing and hyperchlorination were inadequate as decontamination procedures, presumably because the organism had colonized interior spaces of valves and associated parts that are inaccessible to chlorine and unaffected by flushing.
An Engineer's View of Privatization: The Chandler Experience
Authors: Westerhoff Garret P.
Published: February 2018

Privatization of a southwestern US wastewater reclamation facility is described from an engineer's point of view, outlining the necessary steps as well as the alternative routes available for a privatization project.
Flavor Profile Analysis: Taste and Odor Control of the Future
Authors: Bartels Jeroen H.M. , Burlingame Gary A. , Suffet I.H. (Mel)
Published: February 2018

A standard method is needed in the drinking water industry to describe the actual flavor and aroma of a water sample in a qualitative and reproducible way, and to provide a quantitative estimate of the intensities of organoleptic (taste and odor) sensations. The method should be applicable for use in all water utilities over a wide range of problems, and each water utility should be able to train its personnel to use such a method without difficulties. The flavor profile method, a method that could be developed into a standard method for sensory analysis of drinking water, is discussed.
The Chemistry and Physiology of Odor Sensitivity
Authors: Amoore John E.
Published: February 2018

Odor threshold testing has demonstrated the wide variation in the normal olfactory sensitivities of a population and the common occurrence of specific anosmia, or “smell‐blindness.” Continuing research on specific anosmia is leading toward a new fundamental classification of primary odors. The relationship between the classification of odors and the descriptive terms used for taste and odor problems in water is discussed, with special reference to the earthy‐musty odor.
Design of the GAC Treatment Facility at Cincinnati
Authors: Westerhoff Garret P. , Miller Richard
Published: February 2018

The world's largest installation of granular activated carbon to treat drinking water is scheduled to be put in operation by the city of Cincinnati, Ohio, in 1988. After five years of pilot studies, details of the design of the facility, including components for on‐site regeneration of the carbon, have been developed. Twelve GAC contactors will provide an empty bed contact time of 15 minutes at a flow rate of 175 mgd (662 ML/d). The use of GAC is expected to remove the low concentrations of organic chemicals that are always present in the Ohio River, the city's water source.
Choosing a Second Generation Computerized Billing System
Authors: Wintish J. Peter
Published: February 2018

The first generation of a computerized billing system was installed in Rochester, N.Y., in 1972, but 10 years later serious shortcomings were apparent. The author describes how the criteria for an updated system were developed and the process by which the water bureau chose an appropriate new system.
Removing Giardia Cysts From Low Turbidity Waters by Rapid Rate Filtration
Authors: Al‐Ani Mohammed Y. , Hendricks David W. , Logsdon Gary S. , Hibler Charles P.
Published: February 2018

Pilot‐plant studies showed that when effective chemical pretreatment is employed in combination with rapid rate filtration, removals of turbidity, total coliform bacteria, and Giardia cysts from low turbidity waters may be greater than 80, 99.9, and 99.9 percent, respectively. Proper coagulation, however, requires the careful selection of chemicals and dosages. It was also observed that for waters having turbidity levels <1 ntu, percent reduction of turbidity can serve as a surrogate indicator of the removal of Giardia cysts.
Technical Note: Biological Removal of Ammonia at Roxana, Illinois
Authors: Crooks Jennifer Kurtz , Snoeyink Vernon L. , Curry Michael D. , Reynolds Marty L.
Published: February 2018

Algal growth on the upper walls of a reaction basin and in a few places on the weirs in an upflow clarifier led investigators to discover that organisms were converting ammonia to nitrogen, which was having a beneficial effect on water quality. The authors believe that if such activity were consciously encouraged, better quality drinking water could be achieved—perhaps at a lower cost.
Managing Droughts Through Triggering Mechanisms
Authors: Hrezo Margaret S. , Bridgeman Phyllis G. , Walker William R.
Published: February 2018

Triggering mechanisms can be developed by authorities for imposing and terminating regulations during droughts. This article reviews the triggering procedures used by seven states and two interstate commissions. Although triggering mechanisms differ in degree of detail and regulatory flexibility, all of the procedures examined provide a set of well‐defined responses that are activated when predetermined conditions are reached. Each plan discussed has been molded to fit local and state conditions, and each demonstrates the importance of coordinated planning for water shortage management prior to the onset of crisis conditions.
Using Chlorine Dioxide for Trihalomethane Control
Authors: Lykins Benjamin W. , Griese Mark H.
Published: February 2018

Because of the November 1979 amendment to the National Interim Primary Drinking Water Regulations, many utilities were faced with changing their disinfection practices to comply with the 0.10‐mg/L maximum contaminant level for trihalomethanes (THMs). After considering various options, one utility, the Evansville (Ind.) Water and Sewer Utility, chose chlorine dioxide disinfection as the most feasible method for controlling THMs. The performance of a 100‐gpm (6.3‐L/s) pilot plant that incorporated chlorine dioxide treatment was compared with that of a full‐scale plant that used chlorination. Chlorine dioxide was so effective for reducing THMs that it has been used in Evansville's full‐scale plant since 1983.
Providing Water for the Ile de France
Authors: Bourbigot Marie Marguerite , Sibony Jacques
Published: February 2018

Highly sophisticated management and water treatment techniques are needed to serve the Paris metropolitan area with potable water. Most of the suburbs depend on supplies from the Seine, the Marne, and the Oise rivers, all of which are subject to the pollutants and accidental spills inherent in a densely populated industrial area. Privately operated water utilities serving the suburbs have responded with a variety of safeguards, including automated monitoring systems that allow immediate adjustments to be made in water treatment plants, interconnections among sources and municipalities, and state‐of‐the‐art treatment techniques. The authors describe the complexities and the challenges of providing high quality drinking water from low quality sources for the most densely populated region of France.
Amended SDWA Marks New Era in the Water Industry
Authors: Cook Michael B. , Schnare David W.
Published: February 2018

The 1986 amendments to the Safe Drinking Water Act will bring about many changes in water utility management and operations in the next few years. The authors outline the mandates of Congress and the goals of the US Environmental Protection Agency in implementing the new legislation.
Occurrence and Public Health Significance of Invertebrates in Drinking Water Systems
Authors: Levy Richard V. , Hart Frederick L. , Cheetham Ronald D.
Published: February 2018

Invertebrates collected from the water distribution system of Worcester, Mass., were found to harbor a variety of bacteria—some of which may be pathogenic to humans—and to protect them from inactivation by chlorine and monochloramine. Currently, the best approach to invertebrate control is elimination of these organisms before they enter the distribution system or physical or chemical modification of their potential habitats within the system.
Western Water Law in Transition
Authors: Wilkinson Charles F.
Published: February 2018

The key elements in traditional western water law were developed in the nineteenth century, when water was viewed almost exclusively as a commodity to support consumptive uses such as mining and irrigation. This article examines a changing American West, which demands efficiency in water use and gives increasing weight to the recreational, wildlife, and aesthetic values of water. Obligations to Indian tribes have also come to the forefront In response to these societal imperatives, water law is undergoing steady and fundamental reform in order to meet modern perceptions of the highest and best use of western water.
Reallocating Water in the West
Authors: Weatherford Gary D. , Shupe Steven J.
Published: February 2018

Water is on the move in parts of the arid West from old uses to new uses. As the cost of developing additional water supplies becomes unacceptable in many areas, water scarcity is coming to mean that new uses can be served only if existing uses are cut back, become more efficient, or are retired. The West is leaving the era of initial water allocation and development and entering an era of reallocation and more efficient management. Most of the water transfers are from irrigated agriculture to cities, but some are from consumptive uses to in‐stream uses. Legal reforms are needed to facilitate the reallocation of water from lower economic uses to higher ones, through water marketing and other means, and to encourage water conservation.
Chemical Products and Toxicologic Effects of Disinfection
Authors: Lykins Benjamin W. , Koffskey Wayne E. , Miller Robert G.
Published: February 2018

Four disinfectants commonly used in US water treatment—chlorine, monochloramine, chlorine dioxide, and ozone—were applied to four parallel streams in a pilot plant in Jefferson Parish, La. Several organics, including surrogates such as total organic carbon and total organic halide, were evaluated to investigate the effects of disinfection and treatment by sand filtration and granular activated carbon (GAC) adsorption. Five toxicologic tests were also conducted to determine the general toxicity and the mutagenic–carcinogenic potential of disinfection or GAC adsorption. Results of the study showed that ozonation of clarified sand‐filtered water produced fewer organics than the other disinfectants studied. The shortterm animal toxicologic studies revealed difficulties in analyzing actual drinking waters for detectable toxic effects.
The Bioregeneration of GAC Used to Treat Micropollutants
Authors: Speitel Gerald E. , DiGiano Francis A.
Published: February 2018

Microbial activity in granular activated carbon (GAC) has the potential to extend the service life of GAC beds through in situ biological regeneration of sorption sites. Bioregeneration with phenol and paranitrophenol (PNP) was examined over the concentration range of 20–100 μg/L and was measured using radiochemical analytical techniques. Bioregeneration ranged from 5 to 22 percent over a 10‐day period and typically showed a lag phase, followed by rapid bioregeneration, and finally a fairly constant, much lower rate. Differences in bioregeneration rate as a function of column position were slight with phenol as the substrate but substantial with PNP, for which bioregeneration was greatest at the influent end and smallest at the effluent end. The experimental results, in combination with mathematical modeling, suggest that bioregeneration can significantly affect the removal of low concentrations of synthetic organic chemicals.
Reform in Costing and Pricing Water
Authors: Mann Patrick C.
Published: February 2018

Pricing is the primary process by which water utilities recover costs. Unfortunately, costing and rate design practices in the water industry lag behind practices in other public utility sectors. This article focuses on water rate innovations, with emphasis on the integration of marginal cost and traditional average cost pricing. Pricing and costing developments in other public utility sectors are discussed in relation to their applicability to water utilities.
Radium Removal Using Sorption to Filter Sand
Authors: Valentine Richard L. , Mulholland Timothy S. , Splinter Roger C.
Published: February 2018

This study evaluated the use of a novel sand filtration process that exploits the natural capacity of filter sand to sorb radium through the use of a periodic dilute acid rinse to maintain its sorptive capacity. Batch studies were conducted to determine distribution coefficients so that performance estimates could be made. Laboratory pilot studies using a partially softened groundwater showed the process capable of reducing 226Ra concentrations by 80 to 90 percent in the presence of iron flocs when daily rinsing was practiced using pH 1 (0.36 percent) or pH 2 (0.04 percent) HCl. Similar removals could be achieved in field studies using water containing 9–11 pCi 226Ra/L obtained from the existing sand filters in a city whose supply is treated for iron removal. Removals in the field were less when simultaneous iron and radium removal was attempted. In addition, estimates of the total sorptive capacity of the sand obtained in continuous‐flow experiments were generally significantly greater than those predicted based on batch results.
Water Utility Makes Use of National Weather Service Radar
Authors: Gerwin Stephen C.
Published: February 2018

The Washington Suburban Sanitary Commission (WSSC) has tied into the National Weather Service radar system to take measures against the disruptions in water service caused by power outages during frequent severe summer thunderstorms. Advance warnings of potential outages enable the utility to fill elevated storage tanks to maximal capacities, and pumping can be done during offpeak periods when electric rates are lower. In addition, repair crews can be stationed at strategic locations in advance of storms so that they do not have to travel long distances to reach affected facilities. The WSSC purchased receiving equipment for the weather information, but the information itself is furnished free of charge by the National Weather Service.
Silvicultural Application of Alum Sludge
Authors: Grabarek Robert J. , Krug Edward C.
Published: February 2018

Various properties of two types of alum sludge were investigated to determine whether silvicultural application was an appropriate method of disposal. These particular sludges did not produce any undesirable leachates, values of which were within limits set out in the Connecticut Public Health Code, nor did they produce aluminum toxicity in plants—even those grown in pure sludge. Alum sludge binds phosphorus, making it unavailable or slowly available to plants and thus possibly limiting plant growth and even physiologically stressing plants. The results of analyses indicated that limited applications of this material on forested land would most likely not measurably affect tree growth. Land application of alum sludge appears to hold promise as a low‐cost disposal alternative.
Past, Present, and Future of Water Management in the UK
Authors: Anson Malcolm
Published: February 2018

This article discusses water supply in the United Kingdom, emphasizing the conditions that led up to the present system of 10 regional water authorities. The functioning of the Wessex Water Authority is described in detail.
Removing Trihalomethane Precursors by Coagulation
Authors: Hubei Richard E. , Edzwald James K.
Published: February 2018

The removal of trihalomethane precursors by coagulation was studied with low turbidity, low alkalinity waters containing high levels of aquatic humic matter. Jar tests were conducted with synthetic and natural waters using alum, high‐molecular‐weight polymers, cationic polymers, and various combinations of these coagulants. Cationic polymers alone were found to be less effective than alum in the coagulation of humic substances. High‐molecular‐weight polymers used as coagulant aids with alum improved turbidity removal but not precursor removal, whereas high‐charge‐density cationic polymers with alum as a coagulant aid provided good precursor removals at low alum dosages.
Organic Contamination of Groundwater: A Learning Experience
Authors: Lau L. Stephen , Mink John F.
Published: February 2018

The discovery of contamination of the potable groundwater supply on the island of Oahu aroused public concern in the early 1980s. Pesticides used in growing pineapple and pipeline spills of aviation fuels caused several essential wells to be taken out of service. Federal and state officials took immediate action to meet the crisis and developed long‐term strategies to address public health concerns. The state legislature mandated closer reporting on the sale and distribution of pesticides and took other steps to strengthen the authority of state environmental officials. From this experience, the authors outline several measures other water utilities can take to forecast or meet similar contingencies.
Design Options for Water Filtration
Authors: Monk Robert D. G.
Published: February 2018

Options for a gravity filtration unit must be carefully evaluated before an optimum design can be finalized. This article explains a number of alternatives, identifies many of their advantages and disadvantages, and reviews the interrelationship of the components of a filtration system so that alternatives can be matched with the peculiarities of each project under consideration. Examples are provided to demonstrate these concepts.
The Influence of Bromide Ion on Organic Chlorine and Organic Bromine Formation During Free Chlorination
Authors: Symons James M. , Fu Paul L.K. , Dressman Ronald C. , Stevens Alan A.
Published: February 2018

The influence of bromide ion on the formation of nonpurgeable organic bromine and nonpurgeable organic chlorine was not studied previously because no analytical technique existed that could separately measure total organic chlorine and total organic bromine. This measurement has been made possible with the application of the neutron activation analysis. Thus, this study determined the influence of bromide ion concentrations on the relative amounts of nonpurgeable organic chlorine and bromine and chlorine‐substituted and bromine‐substituted trihalomethanes formed during the free chlorination of drinking water over various reaction times and pH values. Measurements of this type are important because bromide ion concentrations are not lowered by conventional drinking water treatment processes, bromide ion is present in many groundwaters, bromide ion may increase the production of trihalomethanes, and the health effects of bromine‐substituted compounds may be different from those of their chlorine‐substituted counterparts.
Point‐of‐Use and Point‐of‐Entry Drinking Water Treatment
Authors: Rozelle Lee T.
Published: February 2018

Point‐of‐use and point‐of‐entry water treatment systems that utilize tested and proven methods are an effective alternative to conventional systems for the reduction of chemical contaminants to acceptable levels. Reverse osmosis is the most universally effective technology for reducing inorganic contaminants. Adsorption by activated carbon is the most universally effective method for reducing organic contamination. Several technologies and their placements are discussed. Field studies concerning point‐of‐use and point‐of‐entry water treatment show this technology to be effective for community application. Thus far, bacterial growth in these devices has not been shown to be a health problem. Preliminary cost information indicates the advantages of point‐of‐use systems, especially for small communities.
Design Considerations and Operating Tips for Small Residential Systems
Authors: Lewis Bruce W.
Published: February 2018

In New Hampshire, many residential housing developments fall outside the service areas of the state's acknowledged private or municipal water utilities. In many cases, developers have installed small residential community water systems to meet the drinking water needs of a rapidly growing population. Proper design and installation are crucial to providing long‐term quality service to this customer group.
Granular Activated Carbon Filter‐Adsorber Systems
Authors: Graese Sandra L. , Snoeyink Vernon L. , Lee Ramon G.
Published: February 2018

The design, operation, and performance of granular activated carbon (GAC) filter‐adsorbers were documented and potential problems were identified by means of a survey of operating plants and a review of the literature. It was found that GAC as a total or partial replacement for sand is as effective as conventional filtration media for removing turbidity, provided an appropriate medium size has been selected. In addition, filter‐adsorbers can consistently eliminate tastes and odors from water supplies for extended periods of time. Sand‐replacement filter‐adsorbers, however, do not function well for removing less strongly adsorbed compounds such as trihalomethanes, volatile organics, and fractions of total organic carbon. More research is needed to determine whether microbial growth in filter‐adsorbers is beneficial or detrimental.
Implementing the New Regulations: A State Regulatory View
Authors: Kelley William A.
Published: February 2018

This paper discusses the 1986 Safe Drinking Water Act Amendments and their effect on existing state water quality programs. The author emphasizes the need for cooperation at the federal, state, and local levels.
Enforcement: USEPA Turns Up the Heat
Authors: Gray Kenneth Fairbanks , Koorse Steven J.
Published: February 2018

The 1986 Safe Drinking Water Act amendments have increased the likelihood that water systems in violation of the act will be subject to enforcement action of some kind. This article discusses the basis for this conclusion and suggests some strategies for coping with the anticipated change in the enforcement climate.
Irrigation Districts: Obstacles to Water Marketing
Authors: Smith Rodney T. , Vaughan Roger
Published: February 2018

The rising value of water is creating profitable opportunities for irrigation districts and their customers to conserve and trade water. Certificate offers would allow each grower to determine, voluntarily, whether the offered price makes it worth transferring water to outside buyers. This arrangement would create financial incentives for irrigation districts and farmers to participate in the market. And it would preserve the powers of irrigation districts to protect the public interest of their communities. Without such mechanisms, water marketing will not play an important role in the management of western water resources.
Water Marketing in Southern California
Authors: Holburt Myron B. , Atwater Richard W. , Quinn Timothy H.
Published: February 2018

The Metropolitan Water District of Southern California, faced with the prospect of severe water supply shortages within the next 20 years, is in the process of negotiating a series of water exchanges, groundwater storage programs, and other arrangements to help meet future demands. The authors describe these programs and discuss the efforts being made to enhance future water supplies for urban areas in Southern California while meeting legal requirements and minimizing the adverse effects on agricultural users.
Urban Use of Arizona's Rural Groundwater
Authors: Kohlhoff Karl F.
Published: February 2018

Mesa, Ariz., the second‐fastest‐growing city in the United States, has joined other burgeoning Arizona cities in buying rural groundwater rights to secure sufficient water supplies for the future. The state's 1980 Groundwater Management Act established comprehensive rules for controlling the use of this valuable underground resource, but the law has proved insufficient to address water‐transfer problems stemming from the clash of urban and rural ideologies that inevitably erupts when cities go into the “water farming” business. This article focuses on Mesa's experience of working closely with rural interests to ensure that its water farming venture will be economically beneficial to both city and rural residents.
Mechanisms of Coagulation With Aluminum Salts
Authors: Dentel Steven K. , Gossett James M.
Published: February 2018

A model is developed that describes the charge neutralization aspects of coagulation, based on fundamental equations describing aluminum speciation and solubility, particle electrodouble‐layer characteristics, and the effect of aluminum‐hydroxide deposition on the surfaces of colloidal or suspended particles. Model predictions are compared with results from closely controlled jar‐test experiments employing the addition of aluminum salts to synthetic suspensions, with good agreement under most conditions. The model's success suggests that charge neutralization coagulation can be explained as the partial coverage of negatively charged particles by positively charged aluminum hydroxide. Predicted conditions of pH and coagulant dosage for optimal destabilization of typical raw waters correspond with those recommended in practice, both for aluminum‐ and iron‐salt coagulants.
Bench‐Scale Evaluation of Coagulants for Low Turbidity Water
Authors: Brink Deborah R. , Choi Suing‐Ill , Al‐Ani Mohammed , Hendricks David W.
Published: February 2018

Because the conventional jar test is ineffective for determining optimal coagulant dosages for low turbidity waters, utilities employing rapid‐rate filtration of such waters may fail to maximize treatment efficiency for lack of a simple bench‐scale test for determining coagulant dosage. Using terms useful to water treatment plant operators, this article describes a simple bench‐scale procedure for determining coagulant dosages for raw water supplies with turbidity levels of 1 ntu or less. The authors explain the protocol for their jar‐filtration test and present documentation on test validity.
A New Age at AWWA
Authors: Jack Mannion John B.
Published: February 2018

In this interview AWWA's new Executive Director, John B. Mannion, outlines his goals for the association and for the drinking water industry.
The Role of the States in Solving the Small System Dilemma
Authors: Miller G. Wade , III John E. Cromwell , Marrocco Frederick A.
Published: February 2018

Although the problem of bringing small water systems into compliance with the 1986 amendments to the Safe Drinking Water Act seems overwhelming, state governments are in a good position to facilitate and influence the solution to this dilemma. State drinking water regulators can give planning, technical, and financial assistance to small utilities; interact with public utility commissions; coordinate the activities of other water‐related state agencies; motivate private investors; and reinforce financial assistance programs. Solving the small system dilemma will require substantial support from the federal government, professional organizations such as AWWA, and the private sector.
Methods of Measuring Disinfectant Residuals
Authors: Gordon Gilbert , Cooper William J. , Rice Rip G. , Pacey Gilbert E.
Published: February 2018

The analytical methods currently used to measure disinfectant residuals, including free chlorine (along with various chloramines), combined chlorine, chlorine dioxide, chlorite ion, chlorate ion, and ozone, are critically evaluated. All methods and recommendations are summarized in a table for easy reference.
Effects of Ozonation on Tastes and Odors
Authors: Anselme Christophe , Suffet I.H. (Mel) , Mallevialle Joel
Published: February 2018

Ozonation was effective for removing musty, earthy, fishy, and muddy tastes and odors from water that had been chlorinated, coagulated, and sand filtered. Astringent and plastic tastes were not significantly removed. The ozonation process was found to be responsible for the development of high‐intensity fruity odors. A combination of statistical and chemical analyses was used to help determine the source and evolution of fruity tastes and odors in potable water treatment.
Flying the International Flag
Authors: Mannion John B.
Published: February 2018

This article discusses the recall of PVC pipe by Pioneer International of Greensboro, Georgia, under the direction of the National Sanitation Foundation (NSF). The recalled pipe may not comply with the maximum level of 2.0 mg/L of residual vinyl chloride permitted under NSF Standard 14 and may leach vinyl chloride monomer to water in excess of the 2.0 mg/L federal standard.
Selected Drinking Water Characteristics and Attached Microbial Population Density
Authors: Donlan Rodney M. , Pipes Wesley O.
Published: February 2018

Cast‐iron test surfaces in a distribution system were exposed to ascertain the relationship between suspended microbial population density, chloramine residual, velocity, water temperature, and selected average solute concentrations and attached microbial population density. The population of attached microorganisms was directly related to water temperature and suspended microbial population density and indirectly related to chloramine concentration and maximum velocity using either analysis of variance or linear correlation. Statistical analysis using linear correlation could demonstrate no strong relationships between pH, alkalinity, organic nitrogen, ammonia, nitrite, nitrate, total phosphate, orthophosphate, or total organic carbon and attached microbial population density.
Developing a Sand‐GAC Filter to Achieve High‐Rate Biological Filtration
Authors: Bablon Guy P. , Ventresque Claire , Aïm Roger Ben
Published: February 2018

A single dual‐layer filter, combining sand and granular activated carbon (GAC) and maintaining the mechanisms of biological treatment, was studied in France as a possible means of achieving high‐rate filtration. Initial results attest that the dual layer far outperforms a single‐layer sand unit, particularly with respect to the removal of suspended solids and ammonia. Using GAC for the top layer of the double filter ensures the removal of appreciable quantities of assimilable carbon and consequently has a positive effect on final chlorination and the palatability of the water.
Coming: Our Own Congressional Campaign
Authors: Mannion John B.
Published: February 2018

Congress has, in effect, taken back the regulatory authority over drinking water that it once gave to the US Environmental Protection Agency. This action, evidenced in the 1986 amendments to the Safe Drinking Water Act (SDWA), augurs enormous practical consequences for US water utilities. Members of Congress rely on the committee system and the committee staffs for background information. The water industry has to become more effective in dealing with these decision‐making committees. The industry also needs to demonstrate to other senators and representatives that the concerns of local water utilities and rate‐payers merit their attention. AWWA and its sister organizations are moving to do just that.
Effectiveness of Conservation‐Oriented Water Rates in Tucson
Authors: Cuthbert Richard W.
Published: February 2018

In arid regions such as the American Southwest, various measures have been implemented to help reduce water use. In this article, the author examines the effectiveness of an inverted (increasing‐block) rate structure as a means of enhancing an already ambitious water conservation program in Tucson, Ariz. Use patterns of single‐family residential customers during a nine‐year period are analyzed, with a focus on inverted water rates. The results suggest that the use of these conservation‐oriented rates in Tucson has significantly helped to reduce single‐family water use during the past decade.
In Remembrance of Abel Wolman
Authors: Mannion John B.
Published: February 2018

Mr. Mannion pays tribute to Abel Wolman and his contributions in the area of public health and water supply, particularly his championing of the use of chlorine.
The Influence of Background Organic Matter on GAC Adsorption
Authors: Summers R. Scott , Haist Brigitte , Koehler Johannes , Ritz Jurgen , Zimmer Gerhard , Sontheimer Heinrich
Published: February 2018

Background organic matter in the Rhine River significantly affected the behavior of trichloroethene (TCE) and 1,2,4‐trichlorobenzene (TCB) in granular activated carbon (GAC) columns. The GAC column adsorption capacity for TCE was found to be more than 50 percent less than that found in batch adsorption experiments. The capacity for TCE of GAC preloaded with organic matter was found to be very similar to that of a TCE‐spiked GAC column, suggesting that the preloading isotherm approach can be useful in predicting GAC column capacity. Because of long‐term reductions in adsorption capacity, the breakthrough of TCE in a full‐scale column is not well predicted by the direct scaleup approach. Complete removal of TCB, presumably by biodegradation, was found after 40 days of operation.
The Impact of Incorporated Organic Matter on the Dewatering Characteristics of Aluminum Hydroxide Sludges
Authors: Dulin Betsy E. , Knocke William R.
Published: February 2018

The effects of coagulation of organic matter by alum (as influenced by coagulation pH, dosage, and potassium permanganate preoxidation) on the thickening and dewatering characteristics of aluminum hydroxide sludges were examined. Sludge dewatering characteristics worsened as the specific amount of organic matter incorporated into the sludge floc matrix increased. The observed changes in sludge characteristics were correlated to a decrease in sludge floc size and density that occurred when greater amounts of organic matter were incorporated into the floc structure. Addition of potassium permanganate improved sludge dewatering rates; the dosage required for improvement was a direct function of the amount of organic matter present in the sludge.
Hereward the Wake
Authors: Mannion John B.
Published: February 2018

Through a conversation with the heroic Anglo‐Saxon patriot Hereward the Wake (Wake meaning the Awake, the Watchful, the Alert and Observant) it is suggested that it would be strategically wise for the water industry to accept the fact that the environmentalists dominate the press, legislative bodies, and public opinion and to align ourselves more or less with that popular cause and reclaim the role of protectors of public health. Mr. Mannion also asks for support of AWWA's “United for Safe Drinking Water” campaign.
Supply Identification for Water Distribution Systems
Authors: Wood Don J. , Ormsbee Lindell E.
Published: February 2018

Identifying the precise source of delivered flow in water distribution systems is increasingly important. The necessity for this arises when individual supplies exceed allowable levels of certain chemical or biological constituents. An explicit methodology to make these calculations for complex water distribution systems is presented. The methodology requires the solution of a set of linear equations of order equal to the number of junctions. The equation coefficients are based on the flow distribution for the system demands under consideration. Because the explicit solution procedure requires the simultaneous solution of large equation sets for large networks, an alternative solution technique was developed. This technique solved the equations in a simple, cyclic manner requiring little computer storage and proved to be an efficient scheme for carrying out the calculations.
Kudos for 75th Anniversary Edition
Authors: Cook Michael B. , Seidel Harris F. , Okun Daniel A.
Published: February 2018

Mr. Metzger responds to the May 1989 Journal article by Ronald A. Smith that encouraged water utilities to employ long‐term contracts for supplying water to large users. Mr. Metzger points out that in many states, including Washington, publicly owned water utilities cannot enter into fixed‐rate contracts absent a statute that expressly provides such authority. The reasoning behind this is based on the fact that the effect of a contract that fixes rates for a specific term suspends the government's power of fixing and regulating such rates. Also, discriminatory rates could result. Mr. Smith responds that he would not support fixing of rates and his primary focus was on the development of a philosophical basis for rates and the various terms and conditions of their administration.
A little lesson in Jargon
Authors: Mannion John B.
Published: February 2018

With tongue‐in cheek, to help put serious matters in proper perspective, Mr. Mannion compiled a lexicon of water jargon. Definitions are given for PPB, MCLG, Additives Program, Risk Extrapolation, GC‐MS, Hormesis, DBCP, GAC, LD50, 404(c), and Persiflage.
Preparing for the Disinfection By‐products Rule: A Water Industry Status Report
Authors: McGuire Michael J.
Published: February 2018

The US Environmental Protection Agency (USEPA) is developing a rule covering disinfection of groundwater supplies and disinfection by‐products (DBPs). The rule is expected to force major changes in disinfection treatment practices. This article describes the critical elements of the rule as well as the work of an AWWA Technical Advisory Workgroup (TAW) assigned to address elements of the forthcoming rule. The role of the Metropolitan Water District of Southern California in managing the TAW is described, along with the various tasks being undertaken by the TAW. Also discussed are results of recent surveys and research projects investigating water utility actions to anticipate the rule.
Correlations Between Trihalomethanes And Total Organic Halides Formed During Water Treatment
Authors: Singer Philip C. , Chang Shengder D.
Published: February 2018

Data obtained from 12 full‐scale treatment plants in six states were evaluated to determine the extent to which correlations exist between trihalomethane (THM) and total organic halide (TOX) formation. Surface waters that had undergone conventional treatment at near‐neutral pH were found to contain a TOX‐to‐TTHM ratio of approximately 3.4:1. On a chlorine‐equivalent basis, the TTHMs comprised approximately 26 percent of the TOX concentration. This TOX‐to‐TTHM ratio corresponded closely to the ratio of TOX formation potential to THM formation potential found in raw waters after a chlorine contact time of seven days at pH 7. In waters subjected to precipitative softening at alkaline pH values, the TTHMs, on a chlorine‐equivalent basis, comprised 39 percent of the TOX concentration.
AIDS Transmission in Drinking Water: No Threat
Authors: Riggs John L.
Published: February 2018

Human immunodeficiency virus (HIV), the pathogen that causes AIDS in humans, can be transmitted in five ways: sexual contact with an infected individual: needle sharing by infected, intravenous drug users; transfusions of infected blood; exposure of wounds or cuts to the blood or body fluids of infected persons; and in utero transmission to infants by infected mothers. There is no evidence that HIV can be transmitted via a waterborne route.
External Corrosion in Distribution Systems
Authors: O'Day D. Kelly
Published: February 2018

Many utilities do not appreciate the fact that routine breaks of metal water mains often result from deterioration caused by gradual external corrosion. The author outlines the basic terms and conditions of galvanic and electrolytic corrosion, summarizes case studies that illustrate causes of external corrosion of underground metal mains and that describe methods to control external corrosion, and discusses the role of soil in external corrosion. Critical research needs identified include prolonging existing main life, identifying and controlling electrolytic corrosion problems, and evaluating the economics of corrosion control for new mains.
Assessing Hollow‐Fiber Ultrafiltration for Particulate Removal
Authors: Jacangelo Joseph G. , Aieta E. Marco , Cams Keith E. , Cummings Edward W. , Mallevialle Joël
Published: February 2018

A pilot study was undertaken to evaluate the efficacy of membrane filtration for the removal of particulate material from two untreated water supplies in Northern California. The permeate produced by the hollow‐fiber ultrafiltration module was assessed by monitoring four water quality parameters: turbidity, suspended solids, direct particle counts, and selected indicator bacteria. The study showed that the ultrafiltration process was very effective in removing particulates from both sources. It appeared that a constant final water quality in relation to particulate material was achieved regardless of the differences in concentrations or numbers of particles in the raw waters.
Removing VOCs by Membrane Stripping
Authors: Zander Amy K. , Semmens Michael J. , Narbaitz Roberto M.
Published: February 2018

This article describes the results of a pilot study conducted to compare the performance of a membrane air‐stripping system with that of packed‐tower aeration for removing volatile organic chemicals from drinking water. It was found that the mass transfer coefficients for the membrane system were generally more than an order of magnitude greater than those for the packed‐tower system. In particular, lower volatility compounds such as bromoform were very efficiently removed by the membrane. The data obtained for the membrane system were also compared with a predictive model developed from chemical engineering literature and verified in the laboratory.
Treatment of Seasonal Pesticides in Surface Waters
Authors: Miltner Richard J. , Baker David B. , Speth Thomas F. , Fronk Carol A.
Published: February 2018

Numerous pesticides were monitored in surface waters in agricultural areas. Atrazine, alachlor, metolachlor, cyanazine, metribuzin, carbofuran, linuron, and simazine were found in the influent to three water treatment plants in stormwater runoff. Studies at these plants, together with bench‐scale studies, demonstrated poor control by conventional treatment processes. The relatively high adsorption capacities of these agrichemicals indicate that granular activated carbon can be cost effective for their control. Powdered activated carbon applied at dosages used for the control of tastes and odors can also be effective if moderate percent removal is required.
Designing Fixed‐Bed Adsorbers to Remove Mixtures of Organics
Authors: Hand David W. , Crittenden John C. , Arora Harish , Miller James M. , Benjamin W. Lykins
Published: February 2018

A liquid‐phase granular activated carbon (GAC) pilot plant and a full‐scale GAC adsorber were designed, built, and operated in order to evaluate their performance for treating a groundwater contaminated with several volatile and synthetic organic chemicals. Several empty bed contact times (EBCTs) ranging from 1 to 30 min were used during the pilot‐plant study, and a simple method for evaluating the GAC use rate as a function of EBCT was developed and demonstrated for dichloroethene and trichloroethene (TCE). Pilot‐plant data were compared with the pore surface diffusion model, which considers external and internal mass transfer mechanisms of pore and surface diffusion. Natural organic matter in the water was found to decrease GAC capacity and kinetics for TCE.