bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving precursor removal
Authors: Spencer Catherine M. , Collins M. Robin 
Published: February 2018

Amending precoat filters with powdered anionic resin significantly increases the removal of organic precursors.The purpose of this work was to determine whether dissolved organic carbon (DOC) could be feasibly removed by diatomaceous earth (DE) precoat filters amended with powdered activated carbon or anionic resin. In the first series of experiments, various precoat configurations of DE size, amendment type and concentration, and precoat weight were evaluated for their initial removals of dissolved organic matter and turbidity from a synthetic raw water source. In the second series of experiments, various body feed compositions were tested for their ability to maintain or improve the turbidity and organic carbon removal achieved by the optimum precoat while head loss through the filter was kept to a minimum. Amending the DE filter with a strong‐base anionic resin in the precoat and body feed achieved significant removals of UV absorbance and DOC (> 50 percent) with excellent turbidity reduction and acceptable head loss development.
Quality Utility Service
Authors: Huber John 
Published: February 2018

Should the water industry certify its treatment operations?This Roundtable discussion about Quality Utility Service was held June 20, 1995, in Anaheim, Calif. The moderator was John Huber, president of Louisville Water Company, 435 S. Third St., Louisville, KY 40202. Other participants were Stephen F. Gorden, director of Detroit Water and Sewerage Department, 735 Randolph, Detroit, MI 48226; W.D. Kingdom, principal management consultant, Water Research Centre, 2655 Philmont Ave., Huntingdon Valley, PA 19006; L.D. McMullen, chief executive officer and general manager, Des Moines Water Works, 2201 Valley Dr., Des Moines, IA 50321; Robert H. Reinert, vice‐president, Malcolm Pirnie Inc., One International Blvd., Mahwah, NJ 07495; David L. Tippin, director, Tampa Water Department, 306 E. Jackson St., Tampa, FL 33602; and Cortez A. White, general manager, Washington Suburban Sanitary Commission, 14501 Sweitzer Lane, Laurel, MD 20707.
Decision‐tree construction and analysis
Authors: Murphy Patrick , Olson Betty H. 
Published: February 2018

Decision‐tree theory may be useful in understanding complex biological systems.Decision‐tree construction and analysis indicate the quantitative occurrence of sulfate‐reducing bacteria in a groundwater basin. The decision‐tree analysis allowed determination of the most important measured variables (discriminators) associated with the occurrence of sulfate‐reducing bacteria. Those variables may be used to improve reliability and validity of the tree. Statistical validation of endpoint data (leaves) is described, and decision trees are presented that increase the understanding of individual wells and hypothesize causes for sulfate‐reducing bacteria.
Filter media rehabilitation at a lime softening plant
Authors: Sr. James R. Mayhugh , Smith John A. , Elder Douglas B. , Logsdon Gary S. 
Published: February 2018

Treating filter media with glacial acetic acid proved an effective alternative to media removal and replacement at a lime‐softening plant.Water filtration plants treating surface water sources can be expected to routinely produce finished water of excellent quality when the source water quality remains steady or changes slowly. When the quality of the source water changes drastically over short periods, however, treatment plants may face severe challenges. Such a situation occurred at the Decatur, Ill., South Water Treatment Plant early in 1994. After a high‐turbidity episode, the lime‐softening plant experienced buildup of coagulant and calcium carbonate deposits in the filter beds. The filters and the deposits were evaluated, and an in situ filter media cleaning technique was successfully applied, using glacial acetic acid.
Optimizing submerged jet flocculator performance
Authors: Sobrinho Jose A. H. , Thiem Leon T. , Alkhatib Eid A. 
Published: February 2018

Particle removal experiments were conducted to uncover operational parameters leading to optimum performance.A 0.126‐L/s (2‐gpm) pilot plant was constructed to evaluate and optimize a novel water‐jet mixing system for flocculation of suspended particles in water. The jet flocculator pilot plant consisted of a long vertical circular column with influent entering through a nozzle on the bottom to create an upflow submerged jet. A perforated plate was placed inside the jet flocculator and positioned above the bottom to create a reactor chamber. Particle removal experiments were conducted to investigate operational parameters such as flows, turbidities, reactor volumes, and arrangements of the perforated plate openings. Optimum jet flocculator conditions occurred when the perforated plate caused a 94 percent reduction in the column area and was located at or near the submerged jet height. Effluent residual turbidities of the optimized jet flocculator were approximately 35 percent for 10‐ntu influents and 10 percent for 100‐ntu influents. When a 75‐cm (30‐in.) depth of pall rings was placed above the perforated plate, a 10 percent decrease in the effluent residual turbidity occurred for only the 10‐ntu influent.
“A‐Team” Decodes ICR for Utilities
Authors: McGuire Michael J. 
Published: February 2018

Utilities working to meet the complex requirements of the Information Collection Rule have immediate access to the experts by telephone or e‐mail.This Roundtable discussion among members of AWWA's “A‐Team” was held in Denver, Colo., Aug. 1, 1996. The moderator was Michael J. McGuire, president of McGuire Environmental Consultants Inc., 469 25th St., Santa Monica, CA 90402. Other participants were Kevin Dixon, director of water quality and ICR coordinator for New Jersey ‘“American Water Co., 213 Carriage Lane, Delran, NJ 08075; Ellen P. Flanagan, assistant commissioner, Chicago Water Department, 1000 E. Ohio St., Chicago, IL 60611; Eva Nieminski, an environmental engineer with the Utah Department of Environmental Quality, 288 N. 1950 W., Salt Lake City, UT 84114; Anne Sandvig, project engineer, Economic and Engineering Services Inc., 525 Belair, Custer, SD 57730; and Charlotte D. Smith, president of Charlotte Smith & Assoc. Inc., POB 1078, Venice, FL 34282.
Wholesale contracts: a resource option
Authors: Miller Ellen G. , Tatham Elaine , Hall Susan 
Published: February 2018

Long‐term wholesale contracts can become a prudent business decision for systems seeking an alternative to “going it alone.”Wholesale contracts are a prudent business option for smaller cities and rural systems that desire to maintain local control while addressing quality requirements and cost limitations. These contracts benefit both sellers (who gain a larger customer base over which to spread costs) and buyers (who gain a product that meets state and federal standards while holding down local costs). As part of a larger strategic planning process, the Kansas City, Mo., Water Services Department undertook an extensive telephone survey of water providers to assess their use of and interest in wholesale contracts. The survey indicated that buy–sell arrangements were common; wholesale contracts must be reached through a long‐term, mutually acceptable business relationship; and regular statements of support by leaders reassure uncertain potential wholesale customers.
Pesticide distributions in surface water
Authors: Stamer John K. , Wieczorek Michael E. 
Published: February 2018

The distribution of pesticide concentrations at two study sites points to herbicides that may affect management of public water supplies.Distributions of concentrations of 46 pesticides were documented from May 1992 through March 1994 for Maple Creek near Nickerson, Neb., and Platte River at Louisville, Neb. As their source of public water supplies, Lincoln and the western part of Omaha withdraw groundwater from the adjacent alluvium near the Platte River site, which is hydraulically connected to the Platte River. Organonitrogen herbicides dominated the pesticide distributions at each site. Variations in the distributions of pesticides at the two sites partly reflect differences in land use and land management practices. Diazinon, an insecticide used in urban areas, was commonly detected at the Platte River site but not at the Maple Creek site. Of the 46 pesticides analyzed at the Platte River site, the herbicides atrazine and alachlor were more likely to exceed their respective maximum contaminant levels of 3.0 and 2.0 μg/L; cyanazine was more likely to exceed the health advisory level of 1.0 μg/L.
Particle removal by flotation and filtration: pretreatment effects
Authors: Valade Matthew T. , Edzwald James K. , Tobiason John E. , Dahlquist Jan , Hedberg Torsten , Amato Tony 
Published: February 2018

Consistent performance of DAF and the quality of DAF effluent—despite considerable variation in flocculation characteristics and flocculated water quality conditions—demonstrate the robust nature of this process.Good dissolved‐air flotation (DAF) and filtration performance were observed for all pretreatment flocculation conditions studied: flocculation times of 5 and 20 min, gate and propeller mixers, two and three stages of flocculation, and low (G of 30 s−1) and high (G of 70 s−1) mixing intensity. The research showed that DAF plants can be designed with flocculation times as low as 5 min and that DAF is a robust particle removal process—i.e., it can produce consistently good water quality for a variety of conditions. Coagulation chemistry (pH and coagulant dosage) has a stronger influence on DAF and filtration performance than physical flocculation design and operating parameters.
Future directions in water quality regulations
Authors: Pontius Frederick W. 
Published: February 2018

Regulatory activity will accelerate over the next few years as USEPA works to meet the requirements imposed by the 1996 SDWA amendments.The Safe Drinking Water Act amendments of 1996 have imposed new requirements on the US Environmental Protection Agency (USEPA) to establish drinking water regulations. The regulatory process has been revised and now requires the use of sound science. Costs, benefits, and competing risks may also be considered. Current regulations for fluoride, volatile organic chemicals, total coliforms, surface water treatment, Phase II and Phase V synthetic organic and inorganic contaminants, and lead and copper remain basically unchanged. New deadlines are established for the regulation of arsenic, sulfate, radon, disinfectants and disinfection by‐products, enhanced surface water treatment, and groundwater disinfection.
Using negotiated guidelines in a facility upgrade
Authors: Pizzi Nicholas G. , Schwarzwalder Ronald O. , Sadzewicz John J. 
Published: February 2018

In Ohio, approval criteria for high‐rate processes are used to design a treatment plant upgrade that secures the required state approval.In Ohio, the use of high‐rate treatment processes requires prior approval from the Ohio Environmental Protection Agency. Approval criteria for high‐rate processes were developed and used for the first time in a study commissioned by the Cleveland Division of Water. The study developed data that aided in the design of an expansion project for the Crown Water Treatment Plant. Data from a pilot‐scale study, which examined the efficiency of high‐rate clarification and high‐rate filtration, confirmed that tube settlers and filters with 1,830 mm (72 in.) of 1‐mm effective size anthracite were appropriate for the plant's expansion and upgrade.
The Charlotte model for competition
Authors: Gullet Barry M. , Bean Douglas O. 
Published: February 2018

In North Carolina, local government competed with the private sector and won.The Charlotte–Mecklenburg Utility Department (CMUD), a municipal agency, provides water and wastewater services to approximately 500,000 residents of Charlotte and Mecklenburg counties in the southern Piedmont region of North Carolina. Spurred by inquiries from the private sector, unsolicited proposals to purchase system components, and political interest, CMUD decided to allow private firms to compete with city staff for the operation and maintenance of two of the department's eight treatment plants. Eight proposals were received from private firms and from the department's own bid team, referred to as Charlotte Mecklenburg–Contract Operations (CM–ConOP). CM–ConOp submitted the lowest‐cost proposal, which will result in savings of $4.2 million over the contract's five‐year term. In addition, the Charlotte model for competition showed that the public sector can compete successfully with private firms and that the result can be a complete change in the way the agency does business.
Rapid performance improvement: one utility's revolution
Authors: Patrick Roger , Meinck Garry 
Published: February 2018

In Western Australia, a traditional water utility rose to meet the challenge of rapid improvement.The Western Australian water industry went through a revolution in 1995. Now more commercial in focus, it is making a greater contribution to Western Australia's economy. At the same time, improved regulatory structures have ensured that standards are met for product quality, service response, environmental impact, and conservation. Pricing is moving to a user‐pays, full‐cost basis, with subsidies explicitly funded by the government.
Technology plans: a smart investment
Authors: Anderson Tully J. , Amatetti Edward J. 
Published: February 2018

Utilities know the value of long‐term planning, a talent they can apply to the development of an integrated approach to information infrastructure.This article addresses planning for information technology and highlights issues that concern utility managers. Information technology offers substantial benefits to utilities; however, there are also pitfalls and costs associated with the technology. The article addresses the major components of an information technology plan and illustrates some difficulties and challenges facing organizations that are installing new information systems.
Predicting DOC removal during enhanced coagulation
Authors: Edwards Marc 
Published: February 2018

Langmuir‐based semiempirical models are used to predict DOC removal during alum and ferric coagulation.The concentration of dissolved organic carbon (DOC) remaining after enhanced coagulation can be predicted with a standard error of about 10 percent or 0.4 mg/L using a new model with inputs of coagulant dosage, coagulation pH, raw water UV254, and raw water DOC. Total organic carbon remaining after coagulation can be predicted with similar accuracy. The model may also be calibrated to a specific site, improving the standard predictive error to 4 percent or 0.27 mg/L (or ±10 percent for 90 percent confidence). Performance differences between equimolar dosages of alum and ferric coagulants in mediating DOC removal may be attributed to (1) equal or better removal of DOC using ferric at very high coagulant dosages, (2) equal or better removal of DOC using alum at lower coagulant dosages, or (3) differing acidity of coagulants, producing a performance advantage for the more acidic coagulant.
Shared residuals processing will benefit adjacent agencies
Authors: Clark David K. , Anderson Catherine A. 
Published: February 2018

Cooperative efforts by neighboring facilities will reduce operating costs for both agencies.The Metropolitan Water District of Southern California (MWDSC) conducted a detailed feasibility study on alternative residuals processing and disposal methods for its Joseph Jensen Filtration Plant. Alternatives to the current practice of sewer disposal were evaluated through literature research, vendor testing, on‐site pilot testing, and joint investigations with outside agencies. As a result of this study, MWDSC and the Los Angeles Department of Water and Power (LADWP), one of MWDSC's 27 member agencies, will enter into an agreement to jointly process residuals from two adjacent water treatment plants operated by the respective agencies. The residuals from the MWDSC plant will be pumped to existing evaporation ponds at the LADWP plant for processing and disposal, and avoided costs will be shared between the two agencies. In addition, the agencies have agreed to exchange standard water treatment chemicals during emergencies.
Enhanced softening: factors influencing DBP precursor removal
Authors: Thompson Jeffrey D. , White Mark C. , Harrington Gregory W. , Singer Philip C. 
Published: February 2018

Bench‐scale tests demonstrate the importance of magnesium hydroxide precipitation and NOM characteristics on precursor removal by softening.Relationships of hardness removal, natural organic matter (NOM) removal, and selected chemical characteristics of NOM were explored, and the implications of the enhanced softening portion of the proposed Disinfectants/Disinfection By‐products Rule were assessed. For most of the nine raw water sources examined, the amount of dissolved organic carbon (DOC) removed (both on an absolute and a percentage basis) correlated strongly with the amount of magnesium precipitated. A semilogarithmic model provided a good fit to the data for six of the nine waters (R2 values >0.8). Greater absolute removal of DOC was achieved for raw waters with higher initial DOC concentrations. DOC removal by softening was most effective for the raw water sources with the highest percentage of hydrophobic organic carbon. Greater specific ultraviolet absorbance values also corresponded to greater DOC removal.
A dual water system for Cape Coral
Authors: Godman Robert R. , Kuyk David D. 
Published: February 2018

Cape Coral, Fla., may well be a model city for water conservation and the most beneficial use of water resources.After much public debate and education regarding the health and cost aspects of a dual water system, such a system is now operating in Cape Coral, Fla. The authors conceived a plan for a dual water reclamation system for the city in 1981 during a drought in south Florida. They studied the city's 300‐mi (480‐km) freshwater canal system to determine how much water would be available for a citywide irrigation system that would be supplemented by reuse of wastewater. Test wells were drilled over the 114‐sq mi (295‐km2) area of Cape Coral to assess the limited supply of treatable potable water for use in all aquifers. In 1992, the first home was connected to the new irrigation supply. About 25 percent of the city is now connected. Cape Coral is the only Florida city that has a detailed utility master plan that includes a citywide nonpotable irrigation system.
Service lines: their effect on microbiological quality
Authors: Prévost Michèle , Rompré Annie , Baribeau Hélene , Coallier Josée , Lafrance Pierre 
Published: February 2018

Water that stagnates for long periods in distribution system service lines is susceptible to increases in bacteria, which can be reduced by extensive flushing.The influence of service lines on the microbiological quality of drinking water was investigated. The microbial water quality in domestic service lines was found to differ from that in the main pipes of the distribution system. Differences in bacterial counts from the first flush of the service line and from the main pipe were generally more pronounced in service lines located near the plant. After a thorough flushing of the service line, however, tap water quality was found to be equivalent to that in the main pipe. Bacteriological parameters studied were total direct count after acridine orange staining, heterotrophic plate counts, total coliforms, and Aeromonas. Physicochemical parameters measured included temperature, oxidant residual, and total, dissolved, and biodegradable organic carbon. Lead and copper concentrations were determined in the first flush, after flushing the service line,
Pennsylvania's filtration evaluation program
Authors: Consonery Phil J. , Greenfield Donald N. , Lee Joseph J. 
Published: February 2018

By identifying weaknesses and optimizing treatment, Pennsylvania has greatly improved performance at its surface water plants.Pennsylvania's Department of Environmental Protection (DEP) initiated a statewide filter plant performance evaluation (FPPE) program for safe drinking water and completed 506 FPPEs at 290 surface water treatment plants. Only 39 percent of the plants were rated “acceptable” for performance at the program's inception in 1988, but by 1996 the percentage had increased to 91 percent—demonstrating that assistance to these systems could lead to successful improvements and decreased risks from waterborne protozoa. The percentage of positive Cryptosporidium (presumptive) samples of the finished water dropped from 35 percent in 1990 to <5 percent in 1996. Positive Cryptosporidium samples have remained below 5 percent in the last five years. The 90th percentile of particle count data showed a postfiltration count of 50/mL in the 3‐ to 18‐μm size range as the threshold for acceptable performance. Because optimized performance is a goal of the FPPE program, the concentrations of 3‐ to 18‐μm particles should remain below 10/mL to minimize breakthrough of pathogenic protozoa. The DEP considers turbidity of <0.1 ntu from each filter as a more optimum level of filter plant performance.
Preliminary testing for control of DBPs in Cleveland
Authors: Pizzi Nicholas G. , Rodgers Margaret L. 
Published: February 2018

Pilot testing of chlorination and ozonation with regular and enhanced coagulation suggests ozonation is not the best choice for the Crown Water Treatment Plant in Cleveland, Ohio.Bench‐ and pilot‐scale studies of total organic carbon (TOC) removal in Lake Erie water using enhanced coagulation, ozonation, and granular activated carbon (GAC) were conducted to determine the applicability of these processes to the upgrade and expansion of the Crown Water Treatment Plant in Cleveland, Ohio. Alum–polymer blends, alum, and ferric chloride more effectively removed TOC than did polyaluminum sulfate–polymer blends. Ozone did not affect TOC concentrations, but it reduced bromochloroacetic acid. Bench‐scale tests showed an optimal dose of 10 mg/L powdered activated carbon with 25 mg/L alum–polymer blend was needed to achieve a 39 percent reduction in TOC. Rapid, small‐scale column tests with GAC beds of 5‐ and 10‐min empty‐bed contact time showed breakthrough at two and six days, respectively; they did not maintain 30 percent TOC reduction after 30 and 100 days, respectively. TOC removal for future control of disinfection by‐products could most effectively be achieved in Cleveland by enhanced coagulation.
Crypto research: are fundamental data missing?
Authors: Klonicki Patricia T. , Hancock Carrie M. , Straub Timothy M. , Harris Stephanie I. , Hancock Keith W. , Alyaseri Ali N. , Meyer Charles J. , Sturbaum Gregory D. 
Published: February 2018

Effective application of Cryptosporidium research is tied to adequate documentation of oocyst quality and enumeration techniques.Noting the dearth of accurate information regarding the quality and quantity of Cryptosporidium oocysts used for experimentation, the authors used isolates meeting stringent quality assurance criteria to document the variation of results with three different enumeration techniques—hemacytometer, cellulose–acetate membrane, and well slide. In 70 comparisons of the three techniques, results generated by well slide and hemacytometer varied by an average of 24.7 percent, hemacytometer and membrane results varied 67.6 percent, and well‐slide and membrane results varied 79.3 percent. Significant discrepancies between counts generated by different techniques indicate a strong probability of poor accuracy in previous enumeration‐based studies. Recovery of oocysts after Percoll‐sucrose flotation varied considerably with either hemacytometer or membrane‐counting techniques, which helps explain low precision with the Information Collection Rule protozoan method. Incomplete description of experimental procedures hinders Cryptosporidium research directed toward improving the analytical method, evaluation of water treatment efficacy, and surrogate development.