bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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.
Selected processes for removing NOM: an overview
Authors: Jacangelo Joseph G. , DeMarco Jack , Owen Douglas M. , Randtke Stephen J. 
Published: February 2018

GAC adsorption and membrane processes offer alternatives to enhanced coagulation for removing NOM.As a result of the anticipated Disinfectants/Disinfection By‐product Rule, there has been increasing emphasis by the water industry on the removal of natural organic matter (NOM) from raw‐water supplies. Three important NOM removal options are coagulation, granular activated carbon (GAC) absorption, and membrane filtration. Of these three processes, coagulation is the most widely used in the water industry. But when coagulation cannot remove adequate concentrations of NOM so that disinfection by‐products can be controlled, other treatment technologies such as GAC and nanofiltration may need to be used Various aspects of each of these technologies are discussed.
Enhanced coagulation: its effect on NOM removal and chemical costs
Authors: Crozes Gil , White Patrick , Marshall Matthew 
Published: February 2018

Coagulation pH appeared to be a determining factor for maximum NOM removal.Several bench‐scale studies were conducted to evaluate the effectiveness of enhanced coagulation for controlling chlorination by‐products and to assess the impace of coaqulation pH preadjustment on total organic carbon (TOC) removal and plant operating costs. Tests were conducted on a variety of surface water sources with TOC values ranging from 2 to 1 mg/L. An iron‐based coagulant, such as ferric chloride, was consisitently more effective than alum in removing natural organic matter (NOM). Coagulation pH appeared to be a determining factor for maximum NOM removal when ferric chloride was used as a primary coagulant. Typically, preadjustment of pH at a value of 6.0 ± 0.2 increased NOM overall removal to as much as 65 percent and reduced the coagulant dose by as much as 60 precent. Enhanced coagulation led to higher overall operating costs, but preadjustment of pH with sulfuric acid reduced costs, by lowering the coagulant dosage as well as sludge production.
Preservation of trace metals in water samples
Authors: Creed John T. , Martin Theodore D. , Sivaganesan Manohari 
Published: February 2018

Metal concentrations in nonacidified drinking water samples may decrease if the sample is held for two weeks.Questions about trace metal preservation are resurfacing because the health effect risks associated with certain metals continue to drive the required reporting limits lower. Inductively coupled plasma‐mass spectrometry was used in this study to analyze preservation of samples containing trace metals. Metal concentrations in nonacidified drinking waters may decrease if the sample is held for two weeks. Acidification of these drinking water samples resolubilized the metals that had fallen out of solution. The preservation of metal samples within drinking waters by acidification to a pH of <2 effectively stabilized the metal concentration for 180 days.
Denitrification using a membrane‐immobolized biofilm
Authors: McCleaf Philip R. , Schroeder Edward D. 
Published: February 2018

Denitrification using a membrane‐immobilized biofilm may offer a more economic nitrate removal method than conventional treatments.Immobilized bacterial cell technology was applied, on a bench scale, to the selective removal of nitrate from contaminated water, together with the segregation of denitrifying bacteria and the carbon energy source from the treated water. The two‐chambered reactor, with a microporous membrane for bacterial cell immobilization, performed at an average denitrification rate of 5,800 mg nitrate‐nitrogen (NO3−‐N)/m2/d of membrane surface area. A carbon‐to‐nitrogen mass consumption ratio of 2.2 g organic carbon/gram nitrogen was observed, with a small degree of methanol contamination of the water being treated. A physical model for NO3−‐N removal based on Fick's law and the measured diffusion coefficient of nitrate through the immobilization structure gave a good correlation with experimental results.
SHAKEN into action
Authors: Tanaka Sandra S. 
Published: February 2018

Lessons learned from the Northridge quake honed LADWP's emergency response operation.On Jan. 17, 1994, Los Angeles faced what has emerged as the most destructive urban disaster in US history—the 6.8‐magnitude Northridge earthquake. In addition to the loss of life and damage to structures, thousands of residents and businesses were crippled because they were without necessary utility services for up to 10 days following the quake. The Northridge earthquake taught us the value of preplanning for emergencies while allowing for flexibility in dealing with the unexpected. A written response plan provides a framework for staffing, outlining various responsibilities rather than identifying individuals in specific roles. But no amount of preparation can take the place of dedicated staff members who are willing to place their work above their personal needs.
Drinking water aluminum and bioavailability
Authors: Reiber Steve , Kukull Walter , Standish‐Lee Perri 
Published: February 2018

Aluminum solubility and chemical changes that take place in the human intestine make ready assimilation of aluminum in drinking water unlikely.This article discusses chemical considerations relative to aluminum uptake in the body and reviews aluminum concentrations, species, and distribution in natural and treated waters. The issue of bioavailability and the likelihood that aluminum in drinking water is more readily assimilated than other forms of aluminum is reviewed and rejected based on issues of solubility and likely chemical transformations that take place