bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Factors to Be Considered in Choosing Pipe
Authors: Inhoffer W. R. 
Published: February 2018

Managers, engineers, maintenance men, and all others interested in transmission mains and water distribution have long been concerned with the age‐old problem of obtaining the best dollar value when purchasing pipe. With the improvement of familiar materials and the introduction of new ones in the manufacture of pipe, AWWA's Engineering and Construction Com. decided that an open discussion by qualified representatives of cast‐iron, steel, reinforced‐plastic, and reinforced‐concrete pipe manufacturers would be appropriate. In addition, a firsthand‐experience report from a major water system would place the problem in perspective. This Joint Discussion was presented at the Annual Conference on May 16, 1973. Each panelist was specifically requested to cover the following items in his presentation: (1) bedding requirements, (2) trench loadings—dead and impact, (3) permissible deflection in and recommended types of joints, (4) resistivity to corrosion, erosion, and chemical action, (5) flexibility during installation, (6) problems with and related costs of distortion potential, and (7) job‐site storage problems.*The first article presents the factors to be considered in deciding what type of pipe to use. The second article makes a case for steel pipe. The third article compares gray and ductile cast‐iron pipe. The last article makes a case for fiber‐glass composite pipe.
Face to Face
Authors: Johnson E.F. 
Published: February 2018

Following graduation from Manhattan College with a Bachelor of Civil Engrg. degree and graduate studies in sanitary engineering at Virginia Polytechnic Inst. & State Univ., James J. Corbalis Jr. began what was to become a notable career in the water‐supply f ield. His first employment was with Wiley& Wilson, Consulting Engineers, in Lynchburg, Va., as a design engineer. He later became a sanitation of f icer for the Virginia State Dept. of Health, followed by a position as sanitary engineer for the County of Fairfax (Virginia.)During WWII he served as an ensign with the US Navy, Civil Engrg. corps. After being discharged, he became a Consulting engineer for the Fairfax County Planning Com., then sanitary engineer for the County of Fairfax, and later engineer‐director for the City of Alexandria San. Auth. He presently is engineer‐director for the Fairfax County Water Auth.Mr. Corbalis has a long list of professional affiliations which include: certified professional engr. (Civil), Virginia; honorary member, AWWA; diplomate, American Academy of Envir. Engrs.; member and past President, Virginia Soc. of Professional Engrs.; member and pastdirector. Natl. Soc. of Professional Engrs.; member and past chairman, Virginia Sect., AWWA; member and past President, Virginia Water Pollution Control Assn.; and member and past President, Virginia Water Pollution Control Assn.; and member and past President, Virginia Water and Sewer Auths. Assn. He is also a member of the Interstate Com. on the Potomac River Basin, and a member of the Technical Advisory Com., Water Resources Planning Bd., Metropolitan Washington Council of Governments.In the following article, AWWA Exec. Dir. Eric Johnson questions Mr. Corbalis about the Fairfax County Water Auth. covering such topics as the formation of the authority, discussion of their Operations, water rights, rate setting, public relations efforts, and labor‐management relations.
Face to Face
Authors: Johnson E. F. , Robinson J. L. 
Published: February 2018

In the following interview J.L. Robinson, director of the Fort Worth (Texas) Water Dept., answers questions asked by Eric Johnson, executive director of AWWA. Some of the points discussed include: the history of the Fort Worth Water Dept., water rates, capital improvements programs, community relations, employee relations, energy considerations, and research programs.Mr. Robinson received a BS degree in chemical engineering from the Univ. of Texas and is a registered professional engineer. He is a member of WPCF and a life member of AWWA. In 1967 he received the William D. Hatfield Award, and in 1975 he received the Arthur Sidney Bedell Award. He has held several regional and national offices in the water, wastewater, and pollution control fields.
Surviving the flood: teamwork pays off in Des Moines
Authors: McMullen L.D. 
Published: February 2018

L.D. McMullen recounts the hour‐by‐hour drama of how the Des Moines Water Works battled the rising Raccoon River and restored water service to residents last summer.Teamwork and communication saved the day last summer for the Des Moines Water Works. Massive flooding shut down the plant in mid‐July and left 250,000 people without drinking water. The utility had been thought to be safe; 25‐ft levees separated it from the Raccoon River, and the previous record flood level had been 19.5 ft in 1947. Last summer, though, the river crested at nearly 27 ft. Utility employees, their efforts to protect the plant unsuccessful, turned their attention to equipment repair and restoration of service. Utility General Manager L.D. McMullen describes how employees met the stated goal of “seven days to pump; thirty days to drink.” He credits the utility's team structure, regular communication among workers and between the utility and the public, and support from citizens, employees' families, local businesses, and suppliers.
Examining the reactions between soluble iron, DOC, and alternative oxidants during conventional treatment
Authors: Knocke William R. , Shorney Holly L. , Bellamy Julia D. 
Published: February 2018

Speciation of iron is necessary in assessing whether oxidant addition will prove advantageous during treatment.Greater knowledge of the interaction between soluble iron, dissolved organic carbon (DOC), and alternative oxidants is warranted if the latter are to be optimized for iron removal. An important conclusion of the work is that speciation of iron (differentiation of particulate, colloidal, and soluble forms) in source‐ and treated‐water samples is needed to determine whether oxidant addition will prove advantageous. Source waters that contain predominantly particulate or colloidal iron may be effectively treated by coagulation and separation processes alone, whereas removal of soluble iron requires the addition of any one of the oxidants studied: potassium permanganate, chlorine dioxide, or hypochlorous acid. Both the concentration and nature of DOC in water were found to affect the residual iron speciation that followed oxidant addition.
Are water rates becoming unaffordable?
Authors: Rubin Scott J. 
Published: February 2018

The problem of affordability of drinking water is not limited to customers of small or rural water systems.National trends in water rates and income levels are examined to determine whether water rates are becoming unaffordable. A more detailed analysis of water rates and income distributions is conducted for 168 water suppliers in Pennsylvania. The author concludes that rates are increasing much more rapidly than income levels for low‐income water customers. Further, the ability of customers to afford water service appears most at risk in large water systems, even though those systems tend to be publicly owned and have lower rates than investor‐owned systems. Overall, anywhere from one in four to one in six water customers is currently paying more than 2 percent of household income for water service. Expected rate increases will place increased pressure on water utilities and all levels of government to develop policies and rate structures to ensure the continued provision of water service to low‐income households.
A volumetric method for assessing Giardia inactivation
Authors: Haas Charles N. , Hornberger Joel C. , Anmangandla Uma , Heath Mark , Jacangelo Joseph G. 
Published: February 2018

Based on these tests, the results of the proposed volumetric method—which has the advantage of reducing labor requirements—were indistinguishable from those of the standard method.Because the standard method of determining Giardia inactivation in disinfection tests—which involves counting dead and living organisms—can be extremely tedious, an alternative method, whereby the concentration of only viable trophozoites is estimated, is being sought. This article describes the development of such a volumetric method and its verification by comparing the results obtained with the standard and volumetric methods. This work demonstrates that the two methods yield equivalent results—at least for the disinfectants and waters examined. Whether this equivalence operates for larger‐scale concentration techniques and for different waters, disinfectants, and organisms remains open to further research.
Privatizing infrastructure options for municipal systems
Authors: Haarmeyer David 
Published: February 2018

Privatization, which operates successfully in France and Britain, offers municipalities a way to harness private‐sector resources and incentives to improve water supply systems.Municipal water supply systems face little competition and generally cannot go bankrupt, so they lack incentives to operate efficiently. Private systems also face problems: rate regulation removes incentives to innovate, and because private systems pay taxes, they are at a competitive disadvantage. To “level the playing field” in the United States, publicly owned water‐supply companies could be transformed into stand‐alone, government‐owned enterprises subject to the same tax and regulatory policies as private water companies. Both this transitory phase and full privatization would expand a municipality's tax base, encourage full‐cost pricing, and lead to less reliance on government financing to upgrade facilities and meet drinking water regulations.
Privatizing the Mexican water industry
Authors: Casasús Carlos 
Published: February 2018

Access to basic services plus betterment of water and sewer systems led to the privatization of Mexico's water industry.Mexico has begun to privatize its water industry in an attempt to provide better water service and produce revenues that match costs. Privatization does not follow the traditional scheme, however. It is structured in the form of a management contract in which the ownership of the infrastructure and control over the politics of implementing the new billing systems remain in the hands of Mexico City's government.
Competitive Adsorption of VOCs and BOM: the Role of Molecular Oxygen
Authors: Sorial George A. , Cerminara Perry , Papadimas Spyridon P. , Suidan Makram T. , Speth Thomas F. 
Published: February 2018

Molecular oxygen further reduced the adsorptive capacity of carbon for the volatile organics studied.In this study, the presence of background organic matter (BOM) was seen to reduce the adsorptive capacity of carbon for chloroform, chlorobenzene, and dibromochloropropane. Adsorption of these compounds was further reduced under oxic conditions. This additional reduction in capacity was likely due to conglomeration of BOM on the carhon surface, which reduced the available surface area for the target volatile organic chemical (VOC). Adsorption isotherms conducted with constant initial concentration ratios of VOC to BOM showed similar behavior. The ideal adsorbed solution theory (IAST) was found to accurately describe anoxic adsorption isotherms for VOCs in water containing BOM but failed to predict this competition for data collected under oxic conditions.
Taking the initiative
Authors: Reid Joe 
Published: February 2018

AWWA's new president is focused on getting the organizational framework established for three initiatives—safe drinking water for all, customer satisfaction, and total water management.Robert L. Wubbena, incoming AWWA president, discussed the broadening scope of the water industry and AWWA's part in it during an April 29 conversation at AWWA headquarters with Joe Reid, managing editor of Waterweek. As president, Wubbena will automatically be a member of the Executive Committee and Board of Directors, and he will also be involved with numerous other committees. Previously he has served AWWA through the General Policy Council, Management Division (chair), Education Division, AWWA/WEF Joint Management Conference (co‐chair), and the Wetlands Technical Advisory Workgroup. He has also served as a Pacific Northwest Section officer and received its Fuller Award in 1982. Wubbena, president of Economic & Engineering Services Inc. in Olympia, Wash., is active in the community and belongs to several other professional organizations. He holds bachelor's and master's degrees in engineering from the University of Iowa.
BOM removal during biological treatment: a first‐order model
Authors: Huck Peter M. , Zhang Shulin , Price Michael L. 
Published: February 2018

The good linear relationships obtained between influent concentration and removal rate for all parameters tested confirm that removal of biodegradable organic matter during biological drinking water treatment can be approximated by a first‐order model.Using data from two pilot‐scale studies and one full‐scale investigation, this article demonstrates that the removal rate in biological water treatment is proportional to the influent concentration to the bioreactor, i.e., a first‐order process. This is true not only for measures of biodegradable organic matter, e.g., assimilable organic carbon, but also for precursors of chlorination by‐products such as trihalomethanes. The slope of the removal rate versus the influent concentration relationship is termed the average specific removal rate, rAS. When data were available from different studies, the rAS values tended to fall in the same range. With a first‐order model, the performance of biological treatment in a given situation can be estimated from limited data. The model is suggested as an approach for the preliminary design of bioreactors for drinking water treatment.
Bromide's effect on DBP formation, speciation, and control: part 1, ozonation
Authors: Shukairy Hiba M. , Miltner Richard J. , Summers R. Scott 
Published: February 2018

Ozonation of high‐bromide waters at ambient pH will likely result in bromate concentrations that exceed the maximum contaminant level specified in the draft D–DBP Rule.The effect of variable ozone dosage and bromide concentration on the formation of organic disinfection by‐products (DBPs) and bromate were evaluated. Low ozone dosages resulted in oxidation of organic precursors, yielding decreases in the formation potential for total trihalomethanes (THMs), six haloacetic acids (HAAs), and total organic halide (TOX). Increasing the ozone dosage oxidized bromide to bromate, decreasing the bromide for incorporation into DBPs. Bromate concentrations were linearly correlated with ozone residuals. Changes in the bromine incorporation factors n and n' reflected differences in the resulting speciation of THMs and HAAs, respectively. Because TOX measurements based on chloride equivalence may underestimate the halogenated DBP yield for high‐bromide waters, a procedure is described whereby bromide and bromate concentrations were used to correct the TOX measurement.
Stainless‐steel piping
Authors: Tuthill Arthur H. 
Published: February 2018

Stainless‐steel piping can be cost‐effective for potable water use.Stainless steel has been used extensively for potable water since the mid‐1960s in desalination plants for handling product water; in potable water treatment plants for gravity filtration and piping; in Tokyo, Japan, for small‐diameter household connection piping; and in New York City for large‐diameter risers and other piping. The most familiar use of stainless steel is for drinking fountains. Background information and general data are given on types 304 (UNS S30400) and 316 (S31600) stainless steel, and their current use in potable water applications is reported. The behavior of stainless steel used with raw, chlorinated, and finished water as well as of piping buried in soil is reviewed. Postfabrication cleanup and maintenance of exterior appearance and cleanliness are also reviewed. Guidelines for procurement and successful use are suggested.
Effect of iron oxide coating on sand filtration
Authors: Stenkamp V. Susie , Benjamin Mark M. 
Published: February 2018

Although the difference in their efficiencies was frequently small, iron‐oxide‐coated sand outperformed uncoated sand as a filter medium in almost all cases.Plain sand was compared with iron‐oxide‐coated sand as a medium for filtration. The coated sand has a positive surface charge at neutral pH, whereas uncoated sand is negatively charged under similar conditions. The influent to the filters contained either latex particles, which were negatively charged in all solutions investigated, or ferrihydrite particles, which were negatively charged at pH > 5 but positively charged at lower pH values. The coated medium outperformed the uncoated one in most experiments, a result that is consistent with expected electrostatic interactions.
Health implications of arsenic in drinking water
Authors: Pontius Frederick W. , Brown Kenneth G. , Chen Chien‐Jen 
Published: February 2018

Definitive answers regarding arsenic health risks at low exposures will be elusive without additional research.The adequacy of the current maximum contaminant level (MCL) for arsenic is being evaluated by the US Environmental Protection Agency. If recent theoretical estimates of chronic effects and cancer risks prove accurate, the current MCL may not effectively protect health. Knowledge of arsenic pharmacokinetics and mechanisms in humans, however, is not complete enough to provide a definitive answer, and current epidemiologic evidence is too inconsistent and too fraught with uncertainty regarding arsenic exposure to be helpful in assessing low‐level risks.
Alternative strategies for removing bromate
Authors: Siddiqui Mohamed , Amy Gary , Ozekin Kenan , Zhai Wenyi , Westerhoff Paul 
Published: February 2018

For all the potential bromate removal processes evaluated, analysis of the treated water showed the formation of bromide ion, indicating that chemical reduction of the bromate is the primary removal mechanism.Stage 1 of the Disinfectants–Disinfection By‐Products Rule specifies a maximum contaminant level of 10 μg/L for bromate ion, a by‐product of the ozonation of natural water containing bromide ion. Several options for removing bromate after its formation are evaluated: reduction with ferrous iron (Fe2+), reduction on the surface of activated carbon, ultraviolet irradiation, and high‐energy electron beam irradiation. For all the processes, bromide was found in the treated water, which indicates that the dominating mechanism of bromate removal is chemical reduction. If Fe2+ is introduced after preozonation, it may function both as a reducing agent for bromate and as a coagulant for dissolved organic carbon removal.
Selecting membranes for removing NOM and DBP precursors
Authors: Fu Paul , Ruiz Hector , Thompson Ken , Spangenberg Carl 
Published: February 2018

A high‐permeability, charged nanofiltration membrane was successfully operated for organics removal under conditions of higher‐than‐normal recovery and flux rate.A membrane filtration pilot plant was operated for one year to evaluate the removal of natural organic matter and disinfection by‐product precursors from a highly colored groundwater in Orange County, Calif. Two nanofiltration (NF) membranes—a traditional softening membrane and a high‐permeability, charged membrane—were selected for pilot‐scale testing based on bench‐scale tests of eight NF and ultrafiltration membranes. The high‐permeability NF membrane demonstrated superior organics removal at very high recovery and flux. It also allowed most inorganic constituents to pass through. The concentrate of low total dissolved solids reduced inorganic fouling and made concentrate reuse possible. The article also presents preliminary design criteria and a cost opinion for full‐scale treatment facilities.
Soil and Hydrology: their effect on NOM
Authors: Aiken George , Cotsaris Evangelo 
Published: February 2018

Soil chemistry, hydrology, and source material affect not only the amount of natural organic matter in an aquatic system but its reactivity as well. They also help water treatment plant operators anticipate problems.Organic mater derived from different source materials has distinctive chemical characteristics associated with those materials. Interactions among organic matter and the minerals and inorganic constituents in soil can result in the removal and fractionation of organic matter, altering the composition and reactivity of the dissolved orgainc carbon (DOC). Hydrologic conditions define the flow path and control the rate of transport of DOC within the system. The nature, distribution, and reactivity of organic matter in a given system is determinde, to a large extent, by the strength and nature of interactions among the various components of the environment.
Effects of bromide and NOM on by‐product formation
Authors: Najm Issam N. , Krasner Stuart W. 
Published: February 2018

Ozone added for disinfection during drinking water treatment reacts with bromide and DOC to form organic and inorganic by‐products, some of which are proven animal carcinogens.Bromide and natural organic matter in water are known to play a role in the formation of ozonation by‐products. Their exact effect on the production of various ozonation by‐products was examined in this bench‐scale study, which used ranges of bromide and dissolved organic carbon (DOC) concentrations typical of US waters. Results show that bromate and cyanogen bromide formations are a function of bromide and Doc concrentrations, with the effect of bromide being more significant. On the other hand, the formation of aldehydes and ketoacids was proportional to the amount of DOC in the water, but they were largely unaffected by bromide concentration. In addition, the ozone dosage needed to achieve the target ozone residual increased with DOC concentration
An update of the federal drinking water regs
Authors: Pontius Frederick W. 
Published: February 2018

The 104th Congress may bring significant reforms to the SDWA as well as to USEPA's drinking water program.Previous articles (published in the Journal in February 1990, March 1992, February 1993, and February 1994) reviewed the history, content, status, and schedule of regulations mandated by the Safe Drinking Water Act. Current developments related to these rules are presented in this article.
Field evaluation of the GWDR's natural disinfection criteria
Authors: Yates Marylynn V. 
Published: February 2018

A virus transport model USEPA is considering generally underpredicted virus concentration at the wells in this study.The draft proposed Ground Water Disinfection Rule (GWDR) will exempt some public water supply systems from disinfecting if they can demonstrate that adequate “natural disinfection” occurs between potential sources of fecal contamination and wells. One way to determine that is to use a virus transport model such as VIRALT, which was developed for the Office of Ground Water and Drinking Water of the US Environmental Protection Agency. For this study, several sites were examined where virus contamination of groundwater has been documented. The necessary hydrogeologic and microbiological data from these sites were obtained and used as input values for VIRALT. The model's predictions were then compared with the measured virus concentrations in wells at the sites. It was found that the model generally underpredicted the virus concentration at the wells. A sensitivity analysis revealed that the model is extremely sensitive to the value of the virus adsorption coefficient and the virus inactivation rate.