bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation and Removal of Assimilable Organic Carbon During Biological Treatment
Authors: Huck Peter M. , Fedorak Phillip M. , Anderson William B.
Published: February 2018

Within the last few years techniques have been developed to measure the easily biodegradable organic material in drinking water. One way of expressing these measurements is as concentration of assimilable organic carbon (AOC). This article presents data obtained in a pilot‐plant study of biological treatment in Edmonton, Alta., using the van der Kooij AOC method. Expected increases in AOC concentrations were seen following ozonation, but some inhibition was also observed. In the dual‐media filters, lower hydraulic loading led to better AOC removals. AOC levels were generally quite low following granular activated carbon treatment. In the absence of broadly accepted criteria for AOC in finished water, several criteria were proposed and used to evaluate plant performance.
Creating Economic Incentives for Conservation
Authors: Vickers Amy , Markus Edward J.
Published: February 2018

US water suppliers are increasingly incorporating conservation into their management strategies as a way to enhance supply capacities and shift consumer demand toward sustainable‐use patterns. Incentives to the utility for following this management strategy, aside from the conserving of water, include reduced investment and operating costs and preservation of environmental assets. Disincentives include revenue shortfalls, more frequent rate adjustments, and difficulty predicting future demand. Recent experience by the electric utility industry indicates innovative program‐financing mechanisms may be required if conservation is to be a worthwhile and economically safe venture, particularly for investor‐owned, regulated water utilities. For example, an important assumption associated with incentive strategies is that increased water efficiency is an equal substitute for water supply capacity and has equivalent value in the marketplace. Utilities need to quantify the economic and environmental assets of a conservation program so those elements may be justly incorporated into the financial considerations of alternative supply‐ and demand‐side planning options.
The (Relative) Insignificance of G in Flocculation
Authors: Han Mooyoung , Lawler Desmond F.
Published: February 2018

The kinetics of flocculation of heterodisperse suspensions like those in water treatment plants are usually described by the Smoluchowski equation, which incorporates collision frequency functions for particle collisions by Brownian motion, fluid shear, and differential sedimentation. These collision‐frequency functions are based on a rectilinear view of collisions, i.e., one that ignores short‐range forces and changes in fluid motion as particles approach one another. With this rectilinear approach, the velocity gradient, G, is the principal design parameter for flocculation units. A curvilinear approach, i.e., one that accounts for short‐range effects in particle collisions, is presented as a set of corrections to the rectilinear collision frequency functions for each mechanism. The primary ramification of this curvilinear, heterodisperse approach is that G is found to be not nearly so important. Previous experimental work in which the role of G has been examined is reviewed in light of this finding.
Assimilable Organic Carbon as an Indicator of Bacterial Regrowth
Authors: Kooij Dirk van der
Published: February 2018

The relationship between the level of regrowth of heterotrophic bacteria and the level of easily assimilable organic carbon (AOC) was determined by collecting and examining a series of distribution water samples from 20 supplies during two summer and autumn periods. The AOC concentration of distribution system water decreased with increasing distance from the treatment plant, but AOC uptake was limited at concentrations <l0 μg C/L. A significant correlation was found between the concentration of AOC in water leaving the treatment plant and the geometric mean of the counts of heterotrophic bacteria in distribution water as determined on diluted broth agar medium. At AOC concentrations <l0 μg C/L, the geometric mean of the colony counts on plate count agar medium (incubated at 22°C) remained below the guideline value of 100 cfu/mL.
Flocculation and Air Requirements for Dissolved Air Flotation
Authors: Edzwald James K. , Walsh John P. , Kaminski Gary S. , Dunn Howard J.
Published: February 2018

Bench‐scale and pilot‐plant studies were used to investigate the effects of flocculation time and floe size on the performance of dissolved air flotation and to determine air requirements for three different types of water supplies. The results show that long flocculation periods are not needed and suggest that floe particles of 10–30 μm should be prepared for flotation. Two measures of the air supplied were examined: percentage recycle and the bubble volume concentration or the volume of air released per volume of water treated. Bubble volume concentrations of 4,600 ppm or 8 percent recycle were sufficient to effectively treat all the waters tested.
Canada's Cooperative Approach to Drinking Water Regulation
Authors: Decker Karen Carter , Long Bruce W.
Published: February 2018

Canada's abundant surface water, so prominent on maps of the country, is not always located where people need it most. One in three Canadians depends on groundwater. Drinking water quality is regulated separately by each of the provinces and territories, but there are common elements in the various policies. In general, Canadians select the highest‐quality supply and protect it or remove the potential sources of contamination. Problems a utility may have meeting the water quality guidelines established by the province are addressed with a cooperative abatement strategy. In this article the authors review regulatory policies, water sources, contamination problems, and treatment strategies for each of Canada's provinces and territories.
Evaluating the Performance of Biologically Active Rapid Filters
Authors: LeChevallier Mark W. , Becker William C. , Schorr Paul , Lee Ramon G.
Published: February 2018

This article examines the application of biological treatment strategies to current problems of the water industry. The studies focused on the production of biologically stable water, increased disinfectant stability, and reduced formation of disinfection by‐products. Results show that biological processes can meet the practical as well as the regulatory requirements of the industry.
Slow Sand: Timeless Technology for Modern Applications
Authors: Lay Trudie , Allen Martin J.
Published: February 2018

Regulations will ultimately require nearly all surface water supplies to be filtered. Together, the water supply professionals, the regulators, and the small communities need to take a closer look at cost‐efficient, low‐surveillance technologies that provide safe, reliable water. Slow sand filtration, one such technology, is experiencing a renaissance of attention. It is an energy‐efficient, lowcost, basic technology that can achieve substantial savings through efficiency of design and simplicity of operation while providing safe water to consumers. However, there is a dark side–inappropriate regulatory requirements and antiquated design criteria.
Workforce 2000: Coming Soon to Your Workplace
Authors: Scharfenaker Mark A.
Published: February 2018

The workforce is shrinking as the baby‐bust generation succeeds the baby boomers, and it is becoming increasingly diverse, with fewer white males and more women, minorities, immigrants, and disabled and older workers. Today's workforce also has different needs and expectations from yesterday's workforce, ranging from family‐friendly benefits to inclusion in employer decision‐making processes. Water utilities are taking action in response to these workforce changes, which are elevating the importance of personnel operations. Implementation of innovative management methods based on flexibility, teamwork, and quality service are showing signs of success.
Transformation of NOM by Ozone and its Effect on Iron and Aluminum Solubility
Authors: Edwards Marc , Benjamin Mark M.
Published: February 2018

Ozonation may alter the functional group composition, molecular weight (MW), and behavior of natural organic matter (NOM) in reactions of significance for drinking water treatment. In this work, the transformation of NOM by ozone was monitored by acid‐base titrations, ion chromatography, and gel‐permeation chromatography (GPC). The results led to an improved understanding of how ozonation affects NOM and how ozonated NOM affects the solubility of freshly precipitated iron and aluminum hydroxides. Organic acidity increased substantially during ozonation, and most of the newly produced organic acid groups were ionized at pH 4.0. Of 27 simple organic acids assayed in ozonated NOM, oxalic acid was dominant. The concentration of oxalate produced upon ozonation increased with ozone dose, solution pH, and Fe(II) concentration. Ozonation of NOM destroyed compounds of high and low apparent MW as determined by GPC and increased the concentration of compounds with intermediate apparent MW. Within the group of compounds formed with intermediate apparent MW, however, the dominant identifiable compounds were low‐MW organic acids such as oxalic and formic acids. Based on this and other observations, changes in the chromatograms of NOM as a result of ozonation appear to reflect changes in functional group composition and polarity of the molecules more—and true MW changes less—than previously recognized. At relatively high ozone doses and slightly acidic pH values, oxalic acid produced upon ozonation of NOM can complex and solubilize significant concentrations of aluminum. The concentration of soluble metal that formed in the presence of ozonated NOM can be predicted reasonably well by considering oxalate as the only metal‐complexing ligand present in such systems.
Assessing the Quality of Flavor Profile Analysis Data
Authors: Meng An‐Kuo , Suffet Irwin H. (Mel)
Published: February 2018

Flavor profile analysis (FPA) data for influent and effluent water samples from two Philadelphia treatment systems were studied, along with quality control protocols, in order to optimize the FPA method. The quality of the data was evaluated for (1) the qualitative description and (2) the quantitative response for each organoleptic descriptor.
Permeation of Organic Contaminants Through Gasketed Pipe Joints
Authors: Glaza Edward C. , Park Jae K.
Published: February 2018

Numerous incidents of drinking water contamination resulting from permeation of organic chemicals in soil through water piping components have been reported in the United States and Europe. The authors of this article immersed samples of gasket materials in gasoline and solvents and exposed actual gasketed pipe segments to gasoline and solvents to determine the susceptibility of various gasket types to permeation. Water inside gasketed pipe segments was analyzed at regular time intervals for the presence of gasoline or solvent using gas chromatography. The results of these exposure tests were used to estimate the concentration of contaminants in the pipe water resulting from permeation through the gasket materials.
Effect of Preozonation on Coagulant–NOM Interactions
Authors: Edwards Marc , Benjamin Mark M.
Published: February 2018

Preozonation of water sources containing natural organic matter (NOM) may alter coagulant requirements, the total organic carbon (TOC) removed by coagulation, and the concentration of aluminum and iron in the finished drinking water. In this work, these phenomena were investigated and interpreted as resulting from (1) changes in the zeta potential of precipitates (floes) that form in the presence of ozonated NOM; (2) slight losses of TOC by oxidation and volatilization of NOM molecules; and (3) changes in the quantity of TOC removed by precipitation and sorption.
Nitrate Contamination of Groundwater: Sources and Potential Health Effects
Authors: Bouchard Dermont C. , Williams Mary K. , Surampalli Rao Y.
Published: February 2018

Because nitrate contamination of groundwater is pandemic and the costs associated with remediating groundwater are high, the question of risk to human health from nitrate needs to be addressed. In order to prevent methemoglobinemia (an acute toxic response to nitrite exposure that precludes transport of oxygen by the blood), the US Environmental Protection Agency has set the maximum contaminant level for nitrate in drinking water at 10 mg nitrate‐N/L. However, it is quite common for groundwater in agricultural areas to exceed this standard at some time during the year. A relationship between nitrate intake and cancer has not been conclusively demonstrated, but some evidence points to a linkage.
Supplying Water and Treating Sewage in Kiev After the Chernobyl Accident
Authors: Tsarik Nikolai
Published: February 2018

After the 1986 catastrophe at the Chernobyl Atomic Power Station near Kiev, Ukraine, the city'ssurface water sources, including the Dnieper River and a reservoir, were contaminated with radionuclides. In addition, certain peculiarities were later noted in the activated sludge at the sewage treatment facilities. The staff of Kievvodokanal (the Kiev Water Supply and Sewer Authority) had to institute immediate and radical measures to protect the populace. These measures included intensive monitoring, cloud seeding, boring of additional wells, and development of contingency plans. In addition, an underground barrier was built around Chernobyl, and a complex, major treatment plant was quickly built on the Desna River because the radioactivity of its water was an order of magnitude lower than in the Dnieper River. The staff is prepared to share its experiences and cooperate with organizations to develop a conceptualized plan for supplying water to population centers in the event of radioactive contamination of water sources.
Factors Affecting DBP Formation During Ozone–Bromide Reactions
Authors: Siddiqui Mohamed S. , Amy Gary L.
Published: February 2018

Ozonation of waters containing bromide ion leads to the formation of organic and inorganic by‐products. By‐product formation is influenced by bromide ion concentration, the source and concentration of organic precursors, pH, ozone dosage, temperature, and alkalinity. Both organic and inorganic by‐products increased when bromide ion concentration increased but decreased with an increase in alkalinity. Organic by‐products were found to increase with a decrease in pH, whereas bromate formation was favored by a high pH. In general, bromoform concentration first increased, then diminished, as the dosage of ozone was increased. Both ozonation and incubation temperatures had a positive effect on the formation of bromoform and bromate. PEROXONE appears to favor bromate formation over organic by‐product formation, whereas the addition of ammonia reduces both bromate and organic by‐products.
Implementation Status of Oregon's Safe Drinking Water Act
Authors: Leland David E.
Published: February 2018

Implementation of amendments to the Safe Drinking Water Act is proceeding on schedule in Oregon and is having major effects on public water systems. For the first time, water systems arc monitoring for many organic chemicals and other toxic substances. Some systems are discovering contamination and are taking corrective action. Water system managers are taking notification of the public more seriously, and consumer awareness and interest are increasing when users are informed of drinking water contamination. Much more extensive bacteriological monitoring is revealing problems for which corrective actions (e.g., installing chlorination) are being taken. Filtration treatment or alternate water sources are being planned, designed, and installed by communities using unfiltered surface water sources. A higher level of expertise and attention is necessary if existing filtration plants are to achieve more stringent finished‐water standards, and some of these plants will need significant modifications to meet these standards. Certified laboratories are continuing to expand their services to meet requests for additional testing by water suppliers. The cost of routine monitoring for water systems is increasing as new requirements come into effect. Public water supplies are beginning to overwhelm existing loan and grant programs in search of funding for mandated capital improvements. The state drinking water program requires substantial increases in funding and personnel to administer the expanded regulatoty program and provide technical assistance to water suppliers in order to meet new standards and solve contamination problems. Statewide budget constraints, however, may result in a large reduction in staffing for the drinking water program.
Emerging Standards For Water Utility Computerization
Authors: Brueck Terrance M. , Gerstberger Richard L.
Published: February 2018

With the continuing proliferation of computer hardware and software, many utilities are facing the problem of system incompatibility and an inability to share and exchange information among systems, resulting in much duplication of effort. To avoid this in the future, open system architecture and common industry standards are being developed. A utility communication architecture for electric utilities, based on open system standards, is currently being modified for use by water utilities.
Removing Nitrate With a Methylotrophic Fluidized Bed: Microbiological Water Quality
Authors: Liessens Jan , Germonpré Richard , Kersters Ilse , Beernaert Stan , Verstraete Willy
Published: February 2018

Fluidized‐bed denitrification of surface water with methanol as the carbon source is currently being studied in Belgium. Residual methanol and microbial excretion products increased the dissolved assimilable organic carbon in the reactor effluent. Hyphomicrobium sp. was isolated as a methylotrophic denitrifier of primary importance. The anoxic denitrifying environment apparently provides a favorable niche for a large diversity of associated bacterial strains. Hydraulic shear resulted in the constant washout of these indicator species from the reactor. Thus, the microbiological quality of the effluent is altered by the denitrifying process, and the treated water has to be further subjected to filtration and disinfection in order to guarantee the removal of residual organic carbon and prevent breakthrough of indicator organisms.
Small System Viability
Authors: Maxwell John M. , Wubbena Robert L.
Published: February 2018

The viability of small water systems in the U.S. has become a major concern. The financial foundations and the level of technical and management skills in small systems are too often inadequate to meet the challenge of providing safe, potable water and reliable service to customers. Four tests to determine financial viability; operating budget; operating cash reserve; capital cash reserve; household income index, are outlined.
Integrating Hydraulic Modeling and SCADA Systems for System Planning and Control
Authors: Schulte Andreas M. , Malm Arthur P.
Published: February 2018

The DuPage Water Commission (DWC) of Elmhurst, Ill., has built a new water distribution network and is monitoring it using an integrated supervisory control and data acquisition (SCADA) simulator (ISS). The ISS integrates DWC's SCADA system and its hydraulic simulator to confirm system design, develop operational scenarios, and train operators to respond to emergencies. Operations personnel have already verified the accuracy of the hydraulic simulator, which enabled them to resolve an operational problem involving a low‐pressure system response. The ISS has been demonstrated for initial system studies, for verification of the transfer mechanism, and for actual storage management studies during unexpected drought strains on the system in the summer of 1992. Emergency training through return of data from the simulator to the SCADA system has been delayed. The training will enable an operator to simulate a main break, for example, and practice alternative responses by manipulating a system of remotely controlled isolation valves. Using the ISS, operators can become familiar with unusual conditions before they occur in the real system, which began operation in January 1992.
Sources of Chlorate Ion in US Drinking Water
Authors: Bolyard Michele , Fair Patricia Snyder , Hautman Daniel P.
Published: February 2018

Samples of untreated source water and finished drinking water were obtained from 42 water utilities which treated their water with oxidants–disinfectants that included chlorine dioxide (ClO2), gaseous chlorine, hypochlorite solutions, and chloramines. Chlorite ion was only detected in water from utilities that used ClO2. Finished water from utilities that used ClO2 or hypochlorite solutions contained comparable concentrations of chlorate ion (ClO3−) in the range 21–660 μg/L. Analysis of the hypochlorite solutions indicated ClO3− contamination was a greater problem in the solutions purchased in concentrations >10 percent available chlorine. Low levels of ClO3− (10–81 μg/L) were also detected in approximately one third of the untreated source samples.
Removing THMs From Drinking Water Using High‐Energy Electron‐Beam Irradiation
Authors: Cooper William J. , Cadavid EvaMaria , Nickelsen Michael G. , Lin Kaijun , Kurucz Charles N. , Waite Thomas D.
Published: February 2018

High‐energy electron‐beam irradiation was shown to be efficient for removing trihalomethanes (THMs) from drinking water. The process was demonstrated on a 1.5‐MeV variable‐current (0–50 mA) electron‐beam system at a flow rate of 120 gpm and on a 60Co gamma source. Of the four THMs, chloroform was the most difficult, i.e., energy‐intensive, to remove. The brominated THMs were much more efficiently destroyed by the process. Organically bound halogens were converted to halide anions, and no organic halogen or oxyhalogen reaction by‐products were observed.
Air‐Stripper Design and Costing Computer Program
Authors: Dzombak David A. , Roy Sujoy B. , Fang Hung‐Jung
Published: February 2018

Packed‐tower, countercurrent air‐stripping is widely used to remove volatile organic compounds from contaminated water. An air stripper is designed using a well‐developed mathematical model of the process. However, the number of variables in the model exceeds the number of constraining equations by two, with the result that a number of alternative air‐stripper designs are possible for a particular water treatment objective. To select one or several designs associated with minimum capital and operating costs, it is necessary to develop a large number of possible designs and to estimate the costs associated with each. The air‐stripper design and costing (ASDC) program, a microcomputer‐based public‐domain program, automates the iterative design and cost calculations and thus enables rapid, preliminary evaluation of alternative air‐stripper designs and associated costs. In this article, the design methodology and cost‐estimation techniques incorporated in ASDC are described, and ASDC cost predictions are compared with costs reported for actual operating air strippers.
Manganese Control During Ozonation of Water Containing Organic Compounds
Authors: Wilczak Andrzej , Knocke William R. , Hubel Richard E. , Aieta E. Marco
Published: February 2018

Bench‐scale tests were conducted to investigate the removal of dissolved manganese from Delaware River water. Prior pilot‐plant results had indicated that manganese was not effectively removed by ozonation, sludge blanket clarification, and filtration, because of the breakthrough or resolubilization of colloidal manganese dioxide [MnO2(s)] species. Increasing the alkalinity was not an effective means of controlling manganese. But application of potassium permanganate after ozonation and at the beginning of coagulation considerably improved the removal of soluble manganese.
Accelerated Testing of Copper Corrosion
Authors: Edwards Marc , Ferguson John F.
Published: February 2018

An innovative, short‐term corrosion test has been developed that can predict long‐term copper corrosion behavior. When used in a six‐day study of uniform copper corrosion in five waters, the test predicted corrosion rates that were in good qualitative and quantitative agreement with known long‐term (210‐day) results. A second phase of the study examined the poorly understood phenomenon of soft‐water pitting. Initial work successfully reproduced soft‐water copper pitting in the laboratory using a synthetic water, facilitating future studies of pit initiation and potential remedies. Relative pitting tendencies were predicted using the short‐term test, as was the long‐term release of the by‐products of copper corrosion. Pitting severity increased with increasing pH and duration of stagnation and decreased in the presence of natural organic matter or chlorine residuals.
Factors Affecting Radium Removal Using Mixed Iron—Manganese Oxides
Authors: Mott Henry V. , Singh Sarabjit , Kondapally Venkateshwer R.
Published: February 2018

Batch experiments confirmed that sorption of radium by a mixed iron‐manganese oxide solid phase shows promise for treating radium‐contaminated water. The capacities of these mixed oxides for sorption of radium depend on the composition of the solid phase, the pH of the aqueous solution, and the presence of competing cations. The removal of the oxide‐radium complexes from aqueous suspension by manganese greensand filtration was also investigated. It was found that influent radium concentrations of 100 pCi/L were reduced to 2–9 pCi/L by this process. Additional study of the fate of radium in manganese greensand filters is recommended before this procedure is used for drinking water treatment.
Analyzing Disinfection Kinetics and Reactor Design: A Conceptual Approach Versus the SWTR
Authors: Lawler Desmond F. , Singer Philip C.
Published: February 2018

The Surface Water Treatment Rule (SWTK) specifies C x T values for achieving various degrees of inactivation of pathogenic microorganisms, with C being the concentration of the disinfectant in the effluent from any reactor and T being a characteristic contact time dependent on reactor hydraulics. The disinfection credit calculated for reactors using the SWTR‐prescribed C x T approach is compared with predictions based on accepted disinfection kinetics and fundamental reactor behavior. This analysis demonstrates that the C x T approach lacks a sound conceptual basis, tends to be somewhat conservative, and is unnecessarily costly for many water treatment plants. A dimensionless parameter, k' Cθ, the product of a disinfection rate constant, the effluent disinfectant concentration, and the theoretical detention time, provides a systematic approach for evaluating disinfection conditions and plant modifications. The decay of chlorine in the reactor is considered, and an error in a previous Journal article is corrected.
Testing Direct Filtration for the Treatment of High‐Turbidity Water
Authors: Logsdon Gary S. , Neden Douglas G. , Ferguson A. Mark D. , LaBonde Shawn D.
Published: February 2018

Pilot‐testing was undertaken by the Greater Vancouver (B.C.) Water District to determine the feasibility of using direct filtration for treating turbid water. Because episodes of natural high turbidity tended to be of short duration, turbidity spiking was included in the investigation. Results showed that turbid water could be treated successfully with direct filtration when a deep‐bed monomedium filter was used; a shallower dual‐media filter was not acceptable. Even with a high‐turbidity raw water, turbidity and production goals were met. Determining the appropriate dosage of filter aid was a key factor in meeting the performance goals.
Waterborne disease in the United States, 1991 and 1992
Authors: Moore Anne C. , Herwaldt Barbara L. , Craun Gunther F. , Calderon Rebecca L. , Highsmith Anita K. , Juranek Dennis D.
Published: February 2018

Although outbreaks of waterborne disease are probably underrecognized and underreported, the reported data are helpful in identifying water treatment deficiencies as well as in characterizing the epidemiology of waterborne disease.

For 1991 and 1992, 17 states and territories reported 34 outbreaks of disease associated with drinking water, which affected an estimated 17,464 people. A protozoal parasite (Giardia lamblia or Cryptosporidium) was identified as the etiologic agent for seven of the eleven outbreaks for which an agent was determined; the remaining four were due to hepatitis A, Shigella sonnei, or chemicals. A lack of treatment or inadequate treatment accounted for the majority of outbreaks, and most (76 percent) were associated with well water. In addition, eight states reported eleven outbreaks of gastroenteritis associated with unintentional ingestion of recreational water. Six of these outbreaks were caused by Giardia or Cryptosporidium. Ongoing for 22 years, this national surveillance of waterborne disease helps to identify deficiencies in water systems and the etiologic agents associated with outbreaks.
Determining the practical quantitation level for arsenic
Authors: Eaton Andrew D.
Published: February 2018

Laboratories using current, approved analytical methods can quantify arsenic in drinking water as low as 4 μg/L.

In light of the fact that the maximum contaminant level (MCL) for arsenic is likely to be lowered significantly, the purpose of this study was to assess the capabilities of laboratories for arsenic analysis by atomic absorption spectrometry at concentrations near those being considered for the revised MCL. The evaluation involved 22 laboratories and used four representative drinking water matrixes to determine a practical quantitation level (PQL) for arsenic, which could be used by the US Environmental Agency in setting the new MCL. Samples were spiked with arsenic at concentrations ranging from 1 to 10 μg/L. On an interlaboratory basis, analytical precision and bias changed markedly at concentrations <4 μg/L, setting a lower limit to the PQL of 4 μg/L. Reliable quantitation levels were also determined.
Privatization in England and Wales
Authors: Jeffery Jack
Published: February 2018

Privatization has improved standards and increased customer involvement.

Privatization of water companies in the United Kingdom was brought about by the Water Act 1989, which brought the 10 existing regional water authorities under a system of regulation based on rate control. The benefits of privatization include increased capital expenditures, better water quality, and greater security of supply. Relationships between managers and employees have become less rigid, and more employees feel there is better chance of reward for good work under the new system of operation.
Supply storage in federal reservoirs
Authors: Wurbs Ralph A.
Published: February 2018

The emphasis in federal reservoir management has shifted from construction of new projects to optimization of existing facilities.

Numerous cities, municipal water districts, and other nonfederal entities have contracted for municipal and industrial water supply storage capacity in federal multipurpose reservoirs, under the provisions of the 1958 Water Supply Act and amendments thereto. In the past, allocation of storage capacity to municipal and industrial water supply and associated sponsorship arrangements have been an integral part of the process of planning and constructing new federal reservoir projects. More recently, cities and other municipal and industrial water suppliers are increasingly viewing storage reallocations and related operational modifications of completed federal reservoir projects as potential sources of supply for meeting growing water needs. Demands on existing facilities will continue to intensify in the future. The author outlines, from an institutional perspective, the role of federal multipurpose reservoirs in municipal and industrial water supply, with a particular focus on storage reallocations at existing projects.
Principles of Community Outreach
Authors: Rubin A. Robert
Published: February 2018

When a decision is to be made in a small community, whether the issue is drinking water, wastewater or solid waste, utility managers and community members must understand not only the facts of the case, but also human nature and societal factors. At North Carolina State University, the Coperative Extension Service has a long history of involvement with small communities that are struggling to reach important decisions. It has developed helpful guidelines for all participants in the decision‐making process. These guidelines are listed in the article.
Dual‐stage filtration proves cost‐effective
Authors: Brigano Frank A. , McFarland James P. , Shanaghan Peter E. , Burton Bruce
Published: February 2018

Dual‐stage filtration reduced turbidity levels and raised water quality at Freestone, Calif.

A prefabricated dual‐stage filtration system was installed as a demonstration project under the USEPA Small System Technology Initiative at Freestone,Calif., a community of approximately 70 people. The filtration system proved to be a cost‐effective compliance option for this small water system, which had a long history of microbiological contamination and boil‐water orders. Dual‐stage filtration of a source water that averaged monthly turbidities of 4.25‐23 ntu consistently produced water with turbidity concentrations well below 0.5 ntu. Using an advanced telemetry device that relayed key operating data to his office 13 mi from the plant site, the operator was able to successfully operate and maintain the equipment working an average of 13 hours/month (including travel time and state‐mandated weekly site visits). The overall cost for the dual‐stage filtration system at Freestone was $7.56/1,000 gal (3.8 mJ), 42 percent less than the estimated cost for a similarly sized coagulation‐filtration system for this site. Transferring ownership of the system to Sonoma County was a key factor in the success of this project.
Precursor control in waters containing bromide
Authors: Symons James M. , Jr. Gerald E. Speitel , Diehl Alicia C. , Jr. Harvey W. Sorensen
Published: February 2018

Trihalomethane and haloacetic acid precursors in water containing high concentrations of bromide ion can be controlled by ozonation and biodegradation without excessive bromate formation.

Two coagulated and settled waters of differing quality and dissolved organic carbon concentration, but with the same bromide concentration, one natural and one spiked, were treated with robust ozonation followed by biodegradation. After free chlorination, these waters were tested for the formation of trihalomethanes (THMs) and, in some cases, haloacetic acids (HAAs). The formation of bromate was also determined. Results were promising, with prospects being good for controlling THMs, HAAs, and bromate in bromide‐containing water.
Inside Senate Bill 2019
Authors: Pontius Frederick W.
Published: February 2018

On May 19, 1994, the Senate passed S. 2019, which would reauthorize the Safe Drinking Water Act (SDWA). Originally introduced by Senator Max Baucus (D‐Mont.) as S. 1547, the bill that was voted on as S. 2019 brought to a close a long and difficult process in the Senate to pass an SDWA bill. A review of the Senate proceedings leading to passage of S. 2019 is available; this review summarizes the content of the bill.
Knowledge‐based systems for maintenance
Authors: Luxhoj James T. , Tao Pen C.
Published: February 2018

A prototype knowledge‐based system, a form of artificial intelligence, was developed to aid human workers in identifying and scheduling maintenance jobs.

A knowledge‐based system (KBS) is useful as a management tool for crew scheduling and site preparation to enhance productivity of maintenance operations for a water distribution system. It aids in identifying tasks and their expected durations, precedence relationships, and requirements for materials, tools, and labor. A prototype KBS is developed that codifies knowledge from field experts for planning maintenance operations for a water distribution system. This case study from Hackensack (N.J.) Water Company examines the influence of weather, traffic, leak severity, and the presence of other utility connections on planning repair operations for joint leaks.
Electrochemical nature of lead contamination
Authors: Singley J. Edward
Published: February 2018

When lead pipe is in contact with water, the rate of lead pickup can be affected by changing the availability of electron acceptors, but in the cases of lead‐based solder and lead‐containing fixtures, corrosion is largely independent of water quality.

Because the minimization of lead pickup by water quality modification has not been predictable, one of the objectives of this work was to provide a basis for such predictions. There are three major situations in which lead is in contact with potable water: lead pipes, lead‐based solders, and brass and bronze fixtures. For lead pipes, the mechanism of corrosion is primarily that of establishing a concentration cell on the lead surface that results in electrons being transferred from one point on the surface to another. Increasing the pH or minimizing the dissolved oxygen or chlorine residual is an effective means of reducing the corrosion rate. For solders and alloys, the galvanic corrosion is due to the direct contact of the dissimilar metals. Water quality has very little effect on this type of corrosion. The author comments that it is hoped that a continuous decrease in lead violations will be seen as the ban on lead solders takes effect and the exposed lead surfaces are removed by corrosion.
A Preview of the New Sulfate Proposal
Authors: Pontius Frederick W.
Published: February 2018

The US Environmental Protection Agency (USEPA) is required to regulate sulfate under the 1986 Safe Drinking Water Act (SDWA) amendments, and a rule has been under development for several years. The agency decided to reconsider a regulation proposed for sulfate under Phase V, which has been previously reviewed. Following deferral of the Sulfate Rule proposed under Phase V, USEPA's sulfate workgroup proceeded to evaluate alternative options for its regulation. Draft regulatory and preamble language was prepared for a new proposed rule. This material was eventually released outside the agency and has been referred to as a “preproposal.” This article is a summary of the preproposal.
Removing EDB with GAC filters
Authors: Narbaitz Roberto M. , Baratta Alan , Parsons Frances Z.
Published: February 2018

Based on the most conservative estimates, computers predicted that the interval between carbon replacements could safely be extended to nine months for 50 percent of the filters.

Nearly 1,000 point‐of‐entry granular activated carbon (GAC) filters are efficiently removing ethylene dibromide (EDB) from contaminated groundwater throughout Florida. This article discusses the design, performance, and operational problems of the filters and assesses the possibility of extending the interval between GAC replacement from the current six months. Few breakthroughs have occurred in these filters, and most were caused by desorption during periods of sharp decreases in well‐water EDB concentrations. Because GAC loading data from the literature described the program data very well, they were used in conjunction with the equilibrium column model to predict the performance of the program's filters for different GAC replacement periods. Based on the most conservative estimates, maintenance for 50 percent of the filters could be extended to every nine months.
Chemistry of arsenic removal during coagulation and Fe–Mn oxidation
Authors: Edwards Marc
Published: February 2018

Recent studies have indicated that arsenic in drinking water is as hazardous as radon in homes and secondhand tobacco smoke.

Arsenic removal during coagulation or Fe–Mn oxidation is examined to aid utilities that desire to improve arsenic removal. Fundamental mechanisms of arsenic removal are discussed, optimization strategies are forwarded, and some new insights are provided to guide future research. Specifically, As(III) removals by coagulation are primarily controlled by coagulant dose and relatively unaffected by solution pH, whereas the converse is true for As(V). When compared on the basis of moles iron or aluminum hydroxide solid formed during coagulation, iron and aluminum coagulants are of demonstrably equal effectiveness in removing As(V) at pH <7.5. However, iron‐based coagulants are advantageous if soluble metal residuals are problematic, if pH is >7.5, or if the raw water contains As(III). Arsenic removal during Fe–Mn oxidation is controlled by the quantity of iron removed [Fe(OH)3 formed] and is relatively independent of the quantity of manganese removed (MnOOH formed).
Choosing Best Practices
Authors: Harmon Rick
Published: February 2018

From meter reading to long‐term asset management, other utilities and industries have practices worth investigating.

Best practices was the topic of a Roundtable discussion held June 22, 1994, in New York, N. Y. The moderator was Rick Harmon, manager of management development programs, AWWA, 6666 W. Quincy Ave., Denver, CO 80235. Other participants were Robert B. Jackson, director of community and intergovernmental relations, Sewerage and Water Board of New Orleans, 625 St. Joseph Street, Room 235, New Orleans, LA 70165; Ron Lovan, general manager of utilities, City of Thornton, 9500 Civic Center Drive, Thornton, CO 80229; Sue F. McCormick, manager of technical support services, Lansing Board of Water and Light, P.O. Box 13007, Lansing, MI 48910; Roger Patrick, principal consultant, PA Consulting Group, 146 Arthur St., North Sydney, NSW 2060, Australia; and Gerald C. (Jerry) Smith, senior vice‐president of operations, American Water Works Service Co., 1025 Laurel Oak Road, Voorhees, NJ 08043.
Performance improvement: a Challenge for water utilities
Authors: Erhardt Ellen Duke , Kramer Gregory L.
Published: February 2018

From “focused improvement” to “reengineering,” management techniques exist to reduce costs, improve customer service, and empower employees.

Performance improvement is the systematic evaluation of processes to ensure that customers' expectations are met in the most cost‐effective manner. When customers' priorities regarding cost, quality, and timeliness are understood, improvement can begin on processes that deliver products and services. Changes can be strategic or tactical and fast or structured. Methods include focused improvement, continuous improvement, restructuring, and process innovation or reengineering. To achieve sustainable results, utility employees should be involved in the process change. By monitoring and evaluating outcomes, the utility can measure change, recognize progress, and set new goals.
Developing rates with citizen involvement
Authors: Reed Robert , Johnson Ronald L.
Published: February 2018

Drought‐related shortages and rate problems have eased for Marin Municipal Water District, which has adopted a three‐tier rate structure that meets revenue needs and enjoys widespread community support.

The Marin Municipal Water District (MMWD) in Corte Madera experienced a particularly severe water shortage during California's six‐year drought. Citizens were frustrated because the district rigidly limited consumption and repeatedly raised rates. As the drought was ending in 1992, MMWD assembled a citizen advisory committee to direct the district and a consulting firm in establishing a new rate structure. More than a cost‐allocation exercise to meet financial needs, the planning process involved important policy issues that required public input. The marginal cost approach chosen meets revenue needs and addresses the problems of limited water supply and expensive source development to meet increased demand. Support for the rate structure is widespread because committee members, who represented most elements of the larger community, were able to reach broad consensus on most issues.
Training improves management effectiveness
Authors: Schmid Patricia Jean , Markel W. J. (Jack)
Published: February 2018

Needs analysis, employee training, and evaluation are the stepping‐stones to success for a training program.

Since the late 1950s, many organizations have had to restructure how they do business to stay competitive in the global market. To do so, companies have identified necessary changes through comprehensive needs analyses, trained the affected employees to meet those changes, and then verified that the changes were occurring at the job site through followup evaluations. This article shows how the same combination of strategies can be successfully used to update management training in an established water utility. The American Water System created its Management Institute by identifying and tying the critical learning issues within the organization to the new training objectives and then validating that those objectives were being met on the job.
Network modeling: advances at a major British utility
Authors: Elton Alan , Schulte Andreas M.
Published: February 2018

The economic benefits of network modeling have outweighed Severn Trent's initial investment, and the less tangible operational and customer benefits continue to grow.

For 14 years, Severn Trent Water has been committed to network analysis to improve understanding of the operation of its assets, which include 23,000 mi of distribution main. The traditional benefits of hydraulic analysis have been achieved over the years, including investment planning, system design, emergency planning, source optimization, and operational strategy development. Recently, the utility implemented a more widespread use of this technology to realize significant additional benefits, including reduced source output, demand management, and pressure control; improved customer service for pressure and quality; reduced service interruptions through improved local planning; and reduced response time for information at local centers. This article reviews organizational changes, software and hardware changes, and ingredients necessary to “make it work.” It also summarizes achievements of the last three years.
Waste stream recycling: its effect on water quality
Authors: Cornwell David A. , Lee Ramon G.
Published: February 2018

Properly treated, blended, and monitored waste streams can be recycled through the water treatment process, thus relieving disposal problems and conserving water.

Waste streams recycled to the influent of a water treatment plant typically contain contaminants at concentrations that are of concern. These contaminants may include Giardia and Cryptosporidium, trihalomethanes, manganese, and assimilable organic carbon. This research shows that proper management—treatment, equalization, and monitoring—of the waste streams can render them suitable for recycling in many situations.
Hydraulic transients cause low‐pressure problems
Authors: Walski Thomas M. , Lutes Teresa L.
Published: February 2018

Mysterious short‐term pressure drops at the top of Cat Mountain prompted an investigation that revealed hydraulic transients as the culprit.

Most engineers are familiar with hydraulic transients that cause problems with excessive pressure in water distribution systems. However, transients can also cause short‐lived low‐pressure problems. This article describes the analysis conducted by the Austin (Texas) Water and Wastewater Utility that identified transients as the source of low pressures in a portion of the city. Pressures recorded during controlled conditions provided the key in identifying pump and valve operation as the source of the problem.