bluuebunny/crossref_metadata_2025 huggingface dataset:
Chlorophyll—a raw water quality parameter
Authors: Jones R. Anne , Lee G. Fred
Published: February 2018

Utilities that use surface water supplies should measure planktonic algal chlorophyll as a raw water quality parameter on a routine basis. Chlorophyll measurement can be a viable substitute for the more costly and tedious algal counting method used by many utilities. A simplified procedure for chlorophyll measurements is presented, and suggestions are made on how water utilities can correlate the results of these analyses with raw water quality parameters of importance to them. Chlorophyll measurements of the lake or impoundment at or near the water supply intake can provide guidance as to the depth at which the water should be taken from the body of water in order to optimize raw water quality and reduce the cost of treatment.
Managing a comprehensive water main reconstruction program
Authors: Corless John P.
Published: February 2018

A comprehensive program for reconstructing the aging portions of the Washington Suburban Sanitary Commission's distribution system consists primarily of cleaning mains and lining them with mortar. This article describes how specific projects are selected, how the work is planned and managed, and how water service is maintained with the least amount of inconvenience to the public during the reconstruction process.
Recent developments in water treatment in France
Authors: Rapinat Michel
Published: February 2018

Source water near Paris, France, has deteriorated in recent years causing a revaluation of traditional chemical treatment of drinking water. Good results have been obtained by using natural biologic purification in conjunction with activated carbon, thus reducing the amount of chemical reagents needed and also improving the taste of the water. Ozone is used before filtration, before activated carbon filtration, and after carbon filtration. The cost of these improved techniques is only about 6 percent more than traditional chemical reagent techniques.
The role of filtration in preventing waterborne disease
Authors: Logsdon Gary S. , Lippy Edwin C.
Published: February 2018

Filtration is an important treatment process in the removal of pathogenic microorganisms and in the prevention of waterborne disease. Historical records indicate that filtration was responsible for reducing death and illness from waterborne disease in 1871 in Germany and for reducing morbidity and mortality from typhoid fever in the United States in the late 1800s‐early 1900s. After studying recent outbreaks of waterborne disease, the authors attribute the causes of these outbreaks to the lack of filtration or to faulty operation and maintenance of the process. Pilot‐plant data and results from full‐scale operation are presented to illustrate the effectiveness of various forms of filtration in reducing microbial populations to concentrations that are easily controlled by disinfection.
Economic research needs relevant to improved drinking water quality
Authors: Russell Clifford S.
Published: February 2018

The role economists can assume in assessing public policies for improving drinking water quality is discussed. Econometric techniques can and should be applied to fields of investigation that have traditionally been limited to health research.
Significance of eutrophication in water supply reservoirs
Authors: Walker William W.
Published: February 2018

Key relationships between eutrophication of surface water supplies and the costs and quality of finished water are reviewed, with an emphasis on problems relating to organics. Data from lakes and reservoirs in the United States indicate a positive correlation between total phosphorus and total organic carbon measurements. In view of this correlation and results of controlled laboratory studies reported in the literature, nutrient enrichment is a significant factor contributing to organohalide problems in surface water supplies. Watershed management for control or reduction of phosphorus export is suggested as a potentially significant and cost‐effective means of dealing with organics‐related problems. Regionally calibrated empirical models can be used in conjunction with appropriate reservoir and watershed monitoring data to assess the extent, significance, and controllability of water quality problems related to phosphorus export and eutrophication.
Hidden costs of accidents can finance safety programs
Authors: Van Dyke Robert P.
Published: February 2018

Since the number and severity of on‐the‐job accidents in the water utility industry exceed the figures for industry as a whole, safety programs for workers are increasingly important in terms of cost savings as well as employee morale. Costs that are not normally identified as injury expenses are more than sufficient to finance safety programs.
Designing and constructing the Trap Falls water treatment plant
Authors: Johnson Mark L. , Doe Peter W.
Published: February 2018

The challenge of designing and building a 94‐ML/d (25‐mgd) water treatment plant to meet new water quality standards was successfully accomplished by the Bridgeport (Conn.) Hydraulic Company. A constricted site located near a highway and several dwellings called for an aesthetic architectural solution as well as the use of unusual water treatment technology. A fast‐track design and construction program achieved the desired results within the time limit set by regulatory agencies at a cost below the original estimate.
Simplifying design of water treatment plants for developing countries
Authors: Wagner E. Glenn
Published: February 2018

Water treatment plants in developing countries should be low in first cost and easy and economical to operate. Maximum use of gravity and hydraulic energy in the treatment process and use of labor instead of equipment in plant operation result in the most effective and economical treatment plant.
Tetrachloroethylene contamination of groundwater in Kalamazoo
Authors: Minsley Bruce
Published: February 2018

Sampling of the Kalamazoo, Mich., water supply indicated unacceptable levels of tetrachloroethylene from an unknown source In a portion of the city's water distribution system and in one of the city's well fields. Sequential test wells were drilled to identify the source of contamination and to plot its movement through the aquifer. Purge wells now protect the remainder of the well field from future contamination by the abandoned dry cleaning business that was found to be the source of the contamination.
Groundwater laws: opportunities for management and protection
Authors: Ballew Walter W.
Published: February 2018

Present and future protection of the nation's groundwaters depends on controlling the interrelated problems of excessive withdrawals and contamination. The author investigated the existing legal authority and identified gaps in federal and state regulatory laws as they apply to use of aquifers underlying the state of Georgia. The findings of this prototype case study could be applied in many states to coordinate and enhance groundwater protection, thus assuring the availability and safety of this natural resource.
Protecting water supply aquifers in areas using deep‐well wastewater disposal
Authors: Garcia‐Bengochea J.I.
Published: February 2018

The geohydrology of Florida allows deep‐well injection of treated wastewater in some areas if care is taken to assure protection of overlying aquifers used for public water supplies. Precautions are described that must be taken during construction, operation, and ultimate abandonment of the disposal wells to assure containment of injected wastes.
Calibrating Water Distribution System Models
Authors: Maloney Stephen W.
Published: February 2018

In response to the article entitled “Using Water Distribution System Models” by Thomas M. Walski (JOURNAL AWWA February 1983), Stephen W. Maloney writes to express his concern over the criterion used by Walski for calibration. Maloney suggests determining the degree of calibration of a computer model by comparing flows predicted by the field test and computer simulation at some arbitrary residual pressure. This type of comparison considers changes in head loss and thus removes the influence of the elevation data from calculations. Simulation equations are presented and explained. Walski responds in agreement with Maloney and states that the criterion for model calibration should be the ratio of observed to predicted head loss.
Coliform occurrence and chlorine residual in small water distribution systems
Authors: Goshko Marc A. , Pipes Wesley O. , Christian Robert R.
Published: February 2018

Samples were collected from seven small (0.09–11 ML/d [0.025–3 mgd]) municipal water systems. Statistical analyses of the data showed that for systems in which the free chlorine residuals vary considerably, there is no association between coliform density and a free chlorine residual of <0.2 mg/L. Enterobacter cloacae and Enterobacter agglomerans were found in samples With a free chlorine residual >0.2 mg/L, whereas Escherichia coli was found only in samples without a free chlorine residual.
Trihalomethane removal by packed‐tower aeration
Authors: Umphres Mark D. , Tate Carol H. , Kavanaugh Michael C. , Trussell R. Rhodes
Published: February 2018

A lime‐softened groundwater and a conventionally treated surface water were used in pilot studies of trihalomethane removals. The results of the two studies were nearly identical. The data were used to determine constants of a correlation for the liquid mass transfer coefficient. The correlation was applied to a process design model to determine a cost‐effective design for 87 percent removal of bromoform.
Conservation: Kudos and Complaints
Authors: Bennett Richard E.
Published: February 2018

This reader writes in disagreement with Wendell Inhoffer, one of the participants in “Roundtable” (JOURNAL AWWA July 1983). Inhoffer stated, among other things, that water saving devices are expensive and have limited effect in drought areas. The author presents results of a USEPA report entitled “Effects of Water Conservation‐Induced Wastewater Flow Reduction” to dispute Inhoffer's views. This report indicates that the use of water saving devices decreases operations and maintenance for wastewater collection systems, decreases chemical use and energy consumption, and decreases mass loadings.
Base–extra capacity water rate design
Authors: Banker R.F. , Costanza Frank B.
Published: February 2018

Increasing emphasis is being placed on developing water rates that reflect the costs of providing water service. The principles and philosophy of one cost‐allocation method—the base–extra capacity method—are discussed.
Chlorinated acids and chloral in drinking water
Authors: Uden Peter C. , Miller Joel W.
Published: February 2018

A quantitative study of chloroform, chloral hydrate, dichloroacetic acid, and trichloroacetic acid in drinking water showed that all four compounds resulted from municipal chlorination. The concentrations of these organics depended on the amount of natural organics in the untreated water. If residual chlorine was present after chlorination, the concentrations depended on the contact time between organics and residual chlorine. Qualitative studies showed that all of the chlorinated compounds found in finished waters were also formed in the chlorination of soil fulvic acids.
Cationic polyelectrolytes as primary coagulants for removing trihalomethane precursors
Authors: Amy Gary L. , Chadik Paul A.
Published: February 2018

Four cationic polymers were tested as sole coagulants for removing trihalomethane precursors from synthetic and natural waters. Waters synthesized from humic acid were more amenable to polymer coagulation than those synthesized from fulvic acid. The presence of kaolinite appeared to improve removal of trihalomethane formation potential (THMFP) from these waters. In general, the performances of the polymers were comparable. For the natural waters, the effectiveness of polymer coagulation in THMFP reduction varied as a function of raw water source. Ambient pH of the water appeared to influence polymer performance. For both types of water, the reductions in THMFP were generally greater than the corresponding decreases in total organic carbon.
Removing uranium from drinking water by metal hydroxides and anion‐exchange resin
Authors: Lee Suk Y. , Bondietti Ernest A.
Published: February 2018

Results of bench‐scale testing on uranium removal from a natural water that was chosen as a good representative of uranium‐bearing waters indicated that conventional coagulant and lime softening treatment removes more than 85 percent of dissolved uranium (83 μg U/L) when an optimum pH and dosage were provided. A strong base anion‐exchange column is a recommended option for the treatment of private well waters containing uranium at higher than desirable levels.
Coliforms in a water distribution system: a remedial approach
Authors: Hudson LeVerne D. , Hankins James W. , Battaglia Michael
Published: February 2018

In 1982 the incidence of noncoliform colonies increased alarmingly in the standard membrane filter tests of samples from the Springfield, Ill., system. This signaled a potential problem with bacteria and was followed by coliform infestation in the water mains. Intensive measures were taken to control bacterial growth in the water treatment process and in the distribution system, with an ultimate goal of preventing the reseeding of the system by chlorine‐resistant organisms.
A statistical experimental design for comparison testing of analytical procedures
Authors: Gibbs Paul H. , Cooper William J. , Ott Edward M.
Published: February 2018

An experiment has been designed for comparison (equivalency) testing of an approved standard test method and an alternative test method. The design has been applied in tests under actual operating conditions at water treatment plants. Statistical analysis of an example data set is detailed. The estimates of single‐analyst precision obtained with this design may reflect the results encountered at any water treatment plant.
Steel Water Storage Tanks
Authors: Buzek John R.
Published: February 2018

The characteristics of various types of steel water storage facilities are described and illustrated to serve as guidelines for selecting appropriate tanks. A summary of the advantages and disadvantages of each design is included.
Determination of Chlorine Dioxide, Chlorine, Chlorite, and Chlorate in Water
Authors: Aieta E. Marco , Roberts Paul V. , Hernandez Margarita
Published: February 2018

This article describes a procedure for either amperometric or potentiometric determination of iodine formed by the oxidation of iodide by chlorine dioxide, chlorine, chlorite, and chlorate. Either phenylarsine oxide or sodium thiosulfate can be used as the titrant. Sample pretreatment and pH adjustment are used to differentiate among the various chlorine species.
Key Elements of Construction Specifications
Authors: Ibbs C. William
Published: February 2018

Three types of serious contract disputes that commonly arise during the construction of water treatment facilities are related to schedule delays, site conditions, and performance of the contract. Typical provisions of construction specifications pertaining to such disputes are examined. Finally, four techniques for resolving disputes are discussed from the project owner's point of view.
Waterborne Disease Outbreaks—1946‐1980: A Thirty‐Five‐Year Perspective
Authors: Lippy Edwin C. , Waltrip Steven C.
Published: February 2018

The 672 outbreaks of waterborne disease that were reported in the United States between 1946 and 1980 affected more than 150 000 persons. An analysis of the data from these outbreaks provides information on how often and where outbreaks occurred, as well as on what caused them.
Reducing Tetrachloroethylene in Vinyl‐Lined Asbestos‐Cement Pipes Through Cement‐Mortar Linings
Authors: Yuskus Leo R.
Published: February 2018

In a research project aimed at eliminating or controlling the leaching of tetrachloroethylene from vinyl‐lined asbestos–cement (A–C) pipe, cleaning and cement‐lining of A–C pipes were studied. Tetrachloroethylene concentrations were reduced by removing the vinyl liner and applying a cement‐mortar liner and by applying cement mortar directly over the vinyl liner.
Effects of Acid Rain on Water Supplies in the Northeast
Authors: Taylor Floyd B. , Symons George E.
Published: February 2018

Results of the first study concerning the impact of acid precipitation on drinking water are reported in terms of health effects in humans as measured by US Environmental Protection Agency maximum contaminant levels. The study focused on sampling surface water and groundwater supplies in the New England states but also included other sites in the Northeast and the Appalachians. No adverse effects on human health were demonstrated, although the highly corrosive nature of New England waters may be at least partly attributable to acidic deposition in poorly buffered watersheds and aquifers.
Temperature Effects on the Use of Metal‐Ion Coagulants for Water Treatment
Authors: Morris Juli K. , Knocke William R.
Published: February 2018

The effects of low‐temperature conditions on the use of alum and ferric chloride for the removal of turbidity were studied. Experimental work involved the use of these coagulants for the removal of kaolin from water samples under both extreme‐low‐temperature and room‐temperature conditions. Analysis of data from a full‐scale treatment plant that experienced failure at low temperature was also included. Temperature effects on coagulation were significant, with low‐temperature conditions producing sharp decreases in turbidity removal efficiency. Alum coagulation was most severely affected. Precipitation studies showed that temperature did not significantly inhibit the rate of metal‐ion precipitation.
Experience With Chlorine Dioxide in Brussels, Part 2: Methods for Controlling Chlorine Dioxide Operation
Authors: Masschelein W.J.
Published: February 2018

Several methods for determining residual active oxidants involved in the generation and dosing of chlorine dioxide are described, including iodometry, specific spectrophotometric methods, and potentiometry. Continuous control in operation is also addressed.
Biologically Induced Variations in the Nature and Removability of THM Precursors by Alum Treatment
Authors: Hoehn Robert C. , Dixon Kevin L. , Malone Jill K. , Novak John T. , Randall Clifford W.
Published: February 2018

A study was conducted to examine whether biological activity in a reservoir, which is partly responsible for seasonal variations in finished water trihalomethane (THM) concentrations, could affect the efficiency of alum coagulation in removing THM precursors. Alum coagulation reduced THM precursors by about 50 percent, and its effectiveness did not appear to be altered by variations in algal or bacterial population densities in the lake. Yields of THMs from the dissolved organic carbon that remained after treatment, however, were generally greater when biological activity in the reservoir was high. Diurnal variations caused by intense biological activity could affect the ability of a water treatment plant to produce water with THM levels consistently less than the maximum contaminant level.
Biological Activated Carbon—At What Cost?
Authors: Neukrug Howard M. , Smith Matthew G. , Maloney Stephen W. , Suffet Irwin H. (Mel)
Published: February 2018

The combination of oxidation by ozonation and adsorption by granular activated carbon is commonly referred to as the biological activated carbon process. This article examines the technical and economic feasibility of incorporating ozone, GAC, or ozone‐GAC unit processes into a conventional water treatment train to remove trace organic compounds, to reduce total organic carbon, and to control unpleasant tastes and odors. Used as a basis for this evaluation are the operating conditions and results of a three‐year, pilot‐scale investigation of advanced water treatment systems that was conducted on Delaware River water in Philadelphia, Pa.
Acid Indexes Indicted
Authors: Schock Michael R. , Taylor Floyd B.
Published: February 2018

In response to “Effects of Acid Rain on Water Supplies in the Northeast” (Journal AWWA March 1984) by Symons and Taylor, Mr. Schock comments that the calcite saturation index (CSI) is so similar to the Langelier Index that nothing new is being taken into account. Its ability to predict the sensitivity of water to acid loading is questionable on the basis of fundamental aqueous chemistry. None of the indexes used in the article can estimate the amount of calcium carbonate that could be dissolved or deposited. Therefore, there is little advantage in promoting the use of over‐simplified indexes that cannot represent real systems. The authors in turn agree that CSI was not to be considered the answer to all of the problems, but rather the intent was to describe what might be a usable, empirical, or practical system for guidance with moderate costs and manageable logistics.
Sampling for Organic Contaminants in Groundwater
Authors: Gibb James P. , Barcelona Michael J.
Published: February 2018

Samples taken for analyzing the quality of groundwater can be altered by certain materials used in the construction of monitoring wells and even by the containers used to collect samples. Similar problems can occur with samples taken from a distribution system. Further research is needed to refine analytical procedures so that actual in situ data pertaining to organic compounds in groundwater can be obtained.
Water Supply in the People's Republic of China
Authors: Okun Daniel A.
Published: February 2018

The challenge of providing one fourth of the world's population with public water supplies is discussed and illustrated with photographs taken by the author on three recent missions to the People's Republic of China.
Real World Design: Appropriate Technology for Developing Nations
Authors: Monk Robert D.G. , Hal Terry , Hussain Mohammed
Published: February 2018

Untimely ideas foisted on unprepared peoples run the risk of becoming albatrosses around their necks. The planet is littered with the technological graveyards of haphazard planning. Developing nations cannot afford these mistakes in the area of water treatment and delivery. Design and engineering concepts must match a nation's ability to build, operate, repair, and pay for them. A low‐technology, labor‐intensive water treatment plant was designed for Chittagong, Bangladesh. It incorporates the use of local materials and labor, limits energy use, and reduces imported technology while surpassing World Health Organization maximum permissible guidelines.
Viewpoint – The Goal: A Predictable National Water Policy
Authors: DeConcini Dennis
Published: February 2018

The United States Congress has approached drinking water legislation in what the author considers a rather fragmented manner. Various closely‐related problems have been dealt with as individual issues. Several features of and proposed amendments to the Safe Drinking Water Act are discussed. Areas of major importance include setting and enforcement of primary standards, compliance, and small system problems. The National Water Alliance (NWA) was founded to address these and other questions outside of Congress. A predictable and stable national water policy is the NWA's chief goal. This “Viewpoint” is an edited version of the address Senator DeConcini delivered on June 11, 1984 at the American Water Works Association annual conference in Dallas, Texas.
A History of the Attempted Federal Regulation Requiring GAC Adsorption for Water Treatment
Authors: Symons James M.
Published: February 2018

The author traces the federal government's attempts to require certain water systems to use GAC adsorption treatment for the removal of synthetic organic contaminants present in source waters. The actions taken by opponents and proponents of the proposed rulemaking are discussed in chronological order, providing an overall perspective of the reasons for the rule's proposal, the reasons for objections to it, and the ultimate abandonment of the proposal. The confusion created by the almost simultaneous proposal for regulating trihalomethanes—a completely separate category of contaminants—is also discussed.
Improved Methods of Designing Filter Boxes
Authors: Monk Robert D. G.
Published: February 2018

It is not necessary to locate filtered‐water weirs above the filter media or to have an excessive depth of water over the media to avoid negative pressures. An understanding of the hydraulics of filters, combined with calculations of fixed head losses and information obtained from pilot studies, permits use of shallower filter boxes that are therefore more economical.
Water Rates and the Rate‐Setting Process
Authors: Woods Charles E.
Published: February 2018

Economic, legal, and policy considerations all play important roles in the design of an equitable, cost‐based rate structure. The financial plan, the notification process, the rate application, the hearing, the approval procedure, and the implementation of the rate order comprise the six stages of the rate‐setting process.
Chlorine Residual Monitoring in the Presence of N‐organic Compounds
Authors: Ram Neil M. , Malley James P.
Published: February 2018

N‐chloroorganic compounds, formed when N‐organic precursors are chlorinated, react similarly with analytical reagents used to determine free available chlorine (FAC) and may lead to falsely positive tests for FAC and an overestimation of the presumed level of disinfection. Bacterial kill measurements were carried out using apparent FAC residuals of 0.2 (±0.01) mg/L or 0.05 (±0.01) mg/L free chlorine as Cl2. Disinfection periods of 15 and 5 min were used, respectively, at pH 7 and 25°C. The results indicated no decrease in the disinfection levels of E. coli in solutions that contained N‐organic compounds compared with control solutions that did not contain such compounds.
Restoring Well Yield in the Netherlands
Authors: van Beek C.G.E.M.
Published: February 2018

This article summarizes the results of research on water well clogging in the Netherlands. The causes, the symptoms characteristic of the various causes, methods of regenerating production, and preventive measures are discussed. In most cases, proper means of rehabilitation and periodic treatment have restored the capacity of the country's wells, and in some instances production has been increased to levels greater than those achieved when the wells were first commissioned.
Scuba Diving: A Tool for Managing Water Quality
Authors: Means Edward G. , Preston Allan E. , McGuire Michael J.
Published: February 2018

In the 40 years since the advent of scuba, few industries other than the offshore oil industry have taken advantage of its commercial possibilities. The drinking water industry's innate affinity to underwater observation has proved the worth of a scuba diving capability in Southern California. The Metropolitan Water District of Southern California has trained and used a group of scuba divers for the past several years in efforts to control water quality in its storage reservoirs. This article outlines the considerations that must be taken into account before such a program is implemented and describes several successful solutions to problems that have been mitigated as a direct result of Metropolitan's scuba diving program.
Water Hammer: Causes and Effects
Authors: Kroon Joseph R. , Stoner Michael A. , Hunt William A.
Published: February 2018

The principles and causes of water hammer are reviewed as a reminder that engineers, operators, and managers of water systems should have at least an intuitive understanding of this hydraulic phenomenon. Potential water hammer problems should be considered when any pipeline design is evaluated, and a thorough surge analysis should be undertaken in many instances to avoid costly malfunctions in a distribution system. The phenomenon of water hammer has not been widely understood, and this disregard cannot be considered good design practice.
Stresses in Saddle‐Supported Ductile‐Iron Pipe
Authors: Evces Charles R. , O'Brien J.M.
Published: February 2018

A study of stresses induced in ductile‐iron pipe by saddle supports is described in this article. Experimental data on strain were used to determine the distribution of stress in the vicinity of the saddle. Results indicate that the optimum saddle angle is in the range of 90–120 degrees. The maximum localized stress for pipe with R/t values ≥ 28 can be approximated by the formula σ = k (P/t2) In (R/t), where k = 0.03 ‐ 0.00017 (β ‐ 90) and β is the saddle angle in degrees.
Converting From Chlorine to Chloramines: A Case Study
Authors: Kreft Peter , Umphres Mark , Hand Jeanne‐Marie , Tate Carol , McGuire Michael J. , Trussell R. Rhodes
Published: February 2018

One of the largest water utilities in the United States has changed from chlorine in its disinfection process to chloramines for controlling the formation of trihalomethanes. A study was conducted to determine if the conversion from free chlorine to chloramine disinfection was feasible for the water system. Technical aspects of chloramination were also addressed before the actual change took place on Nov. 5, 1984. This article recounts the issues that were evaluated prior to making the change to chloramines.
Experience With Chlorine Dioxide in Brussels, Part 3: Operational Case Studies
Authors: Masschelein W.J.
Published: February 2018

Brussels, Belgium, obtains much of its potable water supply from the River Meuse, which is heavily influenced by seasonal precipitation in the temperate climatic zone. The river is affected by human sewage, algal blooms, humic substances, and the infusion of hard groundwater. Chlorine dioxide is used at treatment plants, pumping stations, and clear water reservoirs along the aqueducts for bacterial disinfection and to prevent THM formation.
Removal of New Indicators by Coagulation and Filtration
Authors: Haas Charles N. , Severin Blaine F. , Roy Dipak , Engelbrecht Richard S. , Lalchandani Ajit
Published: February 2018

The removal of yeasts and acid‐fast organisms by chemical coagulation and rapid‐rate sand filtration was compared in laboratory studies with that of the currently accepted group of indicator organisms, total coliforms. These studies indicate that coagulation and filtration do not remove yeasts and acid‐fast organisms to a greater extent than coliform organisms, and since yeast and acid‐fast organisms are more resistant to chlorine than coliforms, yeasts and acid‐fast organisms may be more valid indicators of the efficiency of water disinfection than the traditional indicators.
Removing Aquatic Humus From Norwegian Lakes
Authors: Vik Eilen A. , Carlson Dale A. , Eikum Arild S. , Gjessing Egil T.
Published: February 2018

Research was conducted to clarify the mechanism of removal of aquatic humus by coagulation with aluminum and to determine the optimum coagulant dosage and pH for maximum removal of humus. In all cases a pH of 5.5 was the optimum for efficient coagulation. Water sources with the greatest amount of low‐molecular‐weight organics were shown to have the highest coagulant demand and the lowest removal of total organic carbon. When sufficient alum was added for maximum removal of humus at the optimum pH, residual aluminum was minimized.
Viewpoint – Securing Colorado's Water Future
Authors: Lamm Richard D.
Published: February 2018

Colorado Governor Lamm's views on necessary changes in water resources planning were excerpted from an article he wrote for the March–April 1985 issue of Colorado Municipalities.
Removing Barium and Radium Through Calcium Cation Exchange
Authors: Myers Anthony G. , Snoeyink Vernon L. , Snyder David W.
Published: February 2018

The removal of barium (Ba) and radium (Ra), which are found in many groundwater sources, was achieved in laboratory studies with an ion exchange process. In the studies, a strong acid resin in the calcium form effectively removed Ba2+ and Ra2+ to meet standards. The resin was regenerated with reclaimed brine, which would reduce disposal problems in actual practice. Total hardness, alkalinity, pH, and other water quality parameters remained unchanged. Additional research is needed, however, to refine the process and establish the costs.
Enumerating Injured Coliforms in Drinking Water
Authors: LeChevallier Mark W. , McFeters Gordon A.
Published: February 2018

This article emphasizes the importance of enumerating injured coliforms in drinking water and reviews the sources of injury, factors influencing the extent of injury, problems in enumerating stressed coliforms, recent advances in enumeration techniques, and the health implications of injured coliforms. Recommendations regarding future research are included.
Bacterial Adhesion and Fouling of Reverse Osmosis Membranes
Authors: Ridgway Harry F. , Rigby Martin G. , Argo David G.
Published: February 2018

Adhesion of selected bacteria to cellulose actetate (CA) reverse osmosis (RO) membranes used in wastewater reclamation processes was investigated to determine its role in membrane fouling and reduced process efficiency. Adhesion of a Mycobacterium sp. previously isolated from an early stage of RO membrane biofouling was relatively unaffected by large variations in the ionic strength or pH of the buffer system. However, trace quantities of a polyoxyethylene ether nonionic detergent almost completely inhibited attachment. The mycobacteria were found to adhere to the CA membrane surface (or to a CA‐affinity column) approximately 25‐fold more effectively than a wild‐type strain of Escherichia coli The ability of Mycobacterium and E. coli to adhere to the membrane was correlated with their relative surface hydrophobicities as determined by their affinities for n‐hexadecane. A similar correlation was established between a hydrophilic wild‐type strain of Acinetobacter phosphadevorus containing a single 17.8 mega‐Dalton plasmid (PYG1) and a more hydrophobic isogenic derivative strain (P7P‐) lacking the PYG1 plasmid. Unlike the P7WT parent strain, the P7P‐derivative produced more fimbrialike appendages, which may account for its enhanced hydrophobic and adhesive properties. The results suggest that hydrophobic interactions between bacterial cell surface components and the CA membrane surface play an important role in the initial stages of bacterial adhesion and RO membrane biofilm formation.
Prepurchasing Ozone Equipment
Authors: Monk Robert D.G. , Yoshimura Robert Y. , Hoover Michael G. , Lo Sherry H.
Published: February 2018

The design of the Los Angeles Aqueduct Filtration Plant calls for pretreatment with ozone to aid in flocculation, to control tastes and odors, to reduce the production of trihalomethanes, to serve as a disinfectant, and to aid in the removal of turbidity. Specifications for the ozone system allowed bidders to choose among several alternatives and postponed the final design of the building housing the ozone system until the equipment had been selected. The bid documents for the ozone system required that specific data be supplied along with bids to ensure a cost‐effective facility over a life cycle of 20 years. Experience with ozone systems of comparable size was also required. It is estimated that this unusual bidding procedure resulted in a cost savings for the city of Los Angeles of more than $5 million.
Using Ozone and Ultrasound to Reduce RO Membrane Fouling
Authors: Lozier James C. , Sierka Raymond A.
Published: February 2018

A study was undertaken to assess the usefulness of ozone and ultrasound in reducing the potential of humic acids to foul reverse osmosis membranes. Ozonation alone increased the filterability of low concentrations of humic acids, but the application of ultrasound during ozonation was detrimental, probably because the sound waves reduced the average particle size of colloidal and suspended solids in the solution. The presence of colloidal silica in the humic acid solutions further reduced the fouling potential through the formation of a porous prefilter on the surface of the simulant RO membrane.
Adequate Disinfection: An Alternative to Mandatory Filtration
Authors: Lippy Edwin C.
Published: February 2018

The author of this letter states that a reasonable and practical alternative to mandatory filtration is to apply and enforce currently available disinfection technology to prevent giardiasis outbreaks until research clearly shows the need for extensive and expensive treatment facilities. He makes the point that giardiasis outbreaks are frequently associated with inadequate or interrupted treatment rather than the lack of filtration. Tables illustrate public water deficiencies associated with giardiasis outbreaks between 1965 and 1983, treatment problems associated with forty‐five waterborne outbreaks of giardiasis 1965‐1983, and chlorine contact time values for public water system giardiasis outbreaks.
Competing Uses for Limited Water
Authors: Campbell Gregg A.
Published: February 2018

As needs for water increase in the growing economy of Colorado, especially in urban areas, old priority uses will inevitably have to give way to new perceptions of beneficial applications. The prior use doctrine, although theoretically applicable to the values of the marketplace, has practical shortcomings when senior water rights are sold for a different use. Agricultural use of water, which consumes a large share of Colorado's water entitlements at a low economic benefit, may have to be curtailed in the future in favor of more valuable uses.
Water: Allocating a Scarce Resource
Authors: Campbell Thomas C.
Published: February 2018

The author addresses shortcomings of the riparian doctrine of water rights as well as the prior appropriation doctrine in view of the increasing pressure on water supplies. To solve the problem of shortages that will inevitably occur, market pricing, in lieu of costly water development projects, is advocated as a means of allocating water supplies for priority uses.
Issue on Reuse Applauded
Authors: Okun Daniel A.
Published: February 2018

The author of this letter, while generally applauding a recent issue dealing with reuse (Journal AWWA, July, 1985), seeks to clarify several points that were presented in that issue. He emphasizes the importance of distinguishing between potable and nonpotable reuse, making the point that nonpotable reuse is widely accepted and is not considered to be as controversial as potable reuse. Furthermore, he contests the conclusion that nonpotable reuse is likely to be more costly than the potable supply and will need to be subsidized by it.
Pilot‐plant Simulation of Corrosion in Domestic Pipe Materials
Authors: Treweek Gordon P. , Glicker Joe , Chow Bruce , Sprinker Michael
Published: February 2018

Pilot‐plant corrosion testing, using pipe inserts fabricated from domestic pipe materials and a typical on–off flow cycle, established equilibrium corrosion rates for domestic pipe materials in the soft, low‐alkalinity water of Portland, Ore. Low corrosion rates for typical consumer plumbing materials were measured by pilot‐plant inserts and verified by pipe samples from consumers' home plumbing. Eight‐hour standing water samples removed from a copper coil, soldered at 20‐ft (6‐m) intervals with a lead–tin solder, exhibited lead and copper levels above the USEPA maximum contaminant levels (MCLs) after exposure to chloraminated water. After exposure to chorinated water, only copper levels were above the MCL. Metal levels began to fall below the MCLs after eight to twelve months' exposure.
Technical Note: Experimental Determination of the Calcium Carbonate Saturation States of Water Systems
Authors: Pisigan Rodolfo A. , Singley J. Edward
Published: February 2018

Emphasis is given to the fact that saturation indexes only indicate the tendency of a water to dissolve or precipitate calcium carbonate (CaCO3). The rate at which a given water attains equilibrium cannot be derived from the saturation index value.
Reducing Aluminum Residuals in Finished Water
Authors: Qureshi Naeem , Malmberg Rickard H.
Published: February 2018

Pilot‐ and plant‐scale tests were conducted in Minneapolis, Minn., in an attempt to reduce aluminum residuals in the finished water. At high pH, when the predominant mode of alum coagulation is sweep coagulation, increasing the intensity of chemical mixing reduced aluminum residuals only slightly. Reducing the pH with acid was effective in reducing the residuals, but posttreatment pH adjustment with lime to stabilize the water increased its hardness. It appears that the most promising means of reducing aluminum residuals is to replace part of the alum dosage with ferric chloride. At both Minneapolis and St. Paul water treatment plants, ferric chloride, at less than half the dosage of alum, reduced the residuals and resulted in longer filter runs.
Recovery of Coliforms in the Presence of a Free Chlorine Residual
Authors: Wierenga John T.
Published: February 2018

Despite the presence of a free chlorine residual, significant numbers of coliforms were recovered from the Grand Rapids, Mich., distribution system during the summers of 1982 and 1983. The first incident appears to have been caused by entry of a slug of contamination into the water supply. The second incident involved persistent recoveries of apparent regrowth organisms and paralleled previous incidents reported by other utilities. The subsequent discovery of several defects in the Grand Rapids water supply system points out the need to determine the source of such organisms, which, unless proved otherwise, must be considered a serious contamination problem.
Assuring Accurate Model Calibration
Authors: Walski Thomas M.
Published: February 2018

Water distribution system models are only as good as the data with which they are calibrated. Simply comparing predicted and observed pressures during normal use cannot ensure accuracy. Some tips for calibration are presented.
The Water Utility Manager's Role in the Legislative Process
Authors: Elwell Frederick H.
Published: February 2018

Water utility managers are urged to participate in the legislative process. Staff and governing bodies should be involved and should be informed as to what needs to be done and what effect proposed legislation is likely to have on the water system. Water managers are encouraged to utilize American Water Works Association (AWWA) contacts at the government affairs office in Washington, D.C., to turn to AWWA sections for help in dealing with legislation that affects them on a state and regional level and for help from section water utility councils, and to develop internal structures within the municipal framework to deal with issues at local and state levels. Guidelines for dealing with the legislative process are provided.
Regulating Streamflows
Authors: Howard Charles D.D.
Published: February 2018

In reply to an article in the September 1985 issue of the Journal AWWA, “Meeting Streamflow Requirements” by Frank Trelease III, the author of this letter comments on the failure of regulations to encourage regimes that protect instream resources while providing outof‐stream benefits.
Chlorination to Prevent and Control Waterborne Diseases
Authors: Lippy Edwin C.
Published: February 2018

An analysis of statistics compiled on outbreaks of waterborne disease from 1946 to 1980 and from 1965 to 1982 showed that disinfection was not provided where it was needed and was not properly operated where it was provided. Chlorine concentration, contact time, pH, temperature, and interfering substances all must be evaluated to determine disinfection requirements. Use of reliable chlorination facilities and proper application of current technology can control and prevent waterborne diseases.
Fungi in Potable Water Distribution Systems
Authors: Rosenzweig William D. , Minnigh Harvey , Pipes Wesley O.
Published: February 2018

Of 207 samples collected from various locations in five small municipal water distribution systems, 103 (49.8 percent) were positive for fungi. Counts ranged between 1 and 6 fungal propagules per 50‐mL sample. Four genera, Alternaria, Aspergillus, Cladosporium, and Penicillium, accounted for 58 percent of the isolates, with Aspergillus the most common (18.4 percent). Statistical analysis of the data to determine any relationship between the presence and number of fungal isolates and five physicochemical and two bacteriological parameters revealed no significant correlations.
The Nature of Organics Removed During Treatment of Mississippi River Water
Authors: Semmens M.J. , Staples A.B.
Published: February 2018

In light of increasing concern for the organic content of potable water supplies and the production of potentially toxic chlorinated organic products, a better understanding of the character of organics removed by commonly used treatment processes is desirable. A variety of chemical and physical characterization techniques were used to identify the changes in organic character resulting from chemical treatments of a Mississippi River water sample.
System Not Always the Source
Authors: Sheythe Larry L.
Published: February 2018

In response to an article entitled “Confluence – Waterborne Giardiasis: Where and Why,” (Journal AWWA, January 1986), the author of this letter to the editor comments that water is unfairly blamed for most Giardiasis outbreaks. He states that 80‐90 percent of the isolated outbreaks of giardiasis are not related to water at all, and, in fact, are caused by poor hygienic conditions in restaurants, homes, and daycare centers. At the same time, the author stresses continued efforts to furnish the safest possible water.
Viewpoint – Britain's Government May Privatize Regional Water Authorities
Authors: Rowntree Norman
Published: February 2018

Sir Norman Rowntree is a former director of the Water Resources Board for England and Wales. A retired professor of civil engineering at the University of Manchester Institute of Science and Technology, he is currently a civil engineering consultant dealing with the public health aspects of water resources management or development. In recognition of his distinguished career, he was knighted 16 years ago.
Variance Analyses and Criteria for Treatment Regulations
Authors: Amirtharajah Appiah
Published: February 2018

The US Environmental Protection Agency may propose treatment regulations, such as mandatory filtration‐disinfection of all surface waters and mandatory disinfection of all groundwaters to safeguard against the microbial pathogens, Giardia and viruses, that are being linked with increasing numbers of outbreaks of waterborne disease. Some water systems may seek variances from the required treatment regulations, either on the basis of the nature of the system's raw water quality or on the basis of an alternative treatment technique. In order to develop the methodology for the variance analyses, the performance capabilities of filtration, disinfection, and reservoir storage are reviewed. Particular attention is focused on the removal and inactivation efficiencies for the target organisms, Giardia and viruses. The three variance analyses described in this article are based on estimating the percent of removal and inactivation of target organisms in a particular system in comparison with standard treatment methods.
Returning Recently Covered Reservoirs to Service: Health and Aesthetic Considerations
Authors: Krasner Stuart W. , Means Edward G.
Published: February 2018

The Metropolitan Water District of Southern California recently placed floating covers on two of its finished‐water reservoirs in order to improve the microbiological quality of the water.
Effects of Low Temperature on the Removal of Trihalomethane Precursors by Coagulation
Authors: Knocke William R. , West Sara , Hoehn Robert C.
Published: February 2018

This study showed that the trihalomethane (THM) concentration in finished water that had been treated at 35.6°F (2°C) was significantly lower than in water treated at 71.6°F (22°C). Water temperature did not appear to affect the removal of total organic carbon (TOC) during coagulation with metal ion salts, but color removal was slightly reduced at low temperatures. The efficiency of coagulation for removing TOC, color, and THM formation potential improved when the water was treated at pH 5 rather than pH 7, regardless of temperature. Removal of low‐molecular‐weight organic substances was found to be more difficult at 35.6°F (2°C) than at 71.6°F (22°C). The data obtained suggest that reduced THM concentrations in finished water during winter are strictly a function of the reduced rate of THM formation.