bluuebunny/crossref_metadata_2025 huggingface dataset:
Viewpoint – The Specter of Cities Without Water
Authors: Graeser Henry J.
Published: February 2018

Now associated with Black and Veatch in Dallas, Texas, Henry J. Graeser was for many years director of water utilities in Dallas. His long association with AWWA dates from 1945 and includes a term as president of the association in the late 1960s. These comments are an edited version of a paper he delivered before the Southwest and Texas sections of AWWA on Oct. 16, 1984, in Little Rock, Ark.
European‐US Practices Pondered
Authors: Stevenson David G.
Published: February 2018

In response to an article in an earlier issue of the Journal American Water Works Association (”Using Polymers With Direct Filtration,” March 1985), the author of this letter compares European and US practices of filter washing and emphasizes the effectiveness of a combination of air and water used simultaneously. He states, further, that two percent wash water consumption is a common guarantee figure in Great Britain with actual values often being one percent or less.
Viewpoint – Public Relations: More Brains Than Bucks
Authors: Brigham Arthur P.
Published: February 2018

Arthur P. Brigham, a public relations consultant, 204 E. Melbourne Ave., Silver Spring, MD 20901, was formerly the public affairs officer of the Washington (D.C.) Suburban Sanitary Commission. These suggestions for developing an effective public relations program were presented at AWWA's 1985 annual conference in Washington, D.C., on June 25.
Discussion: Prediction of Organic Chemical Permeation Through PVC Pipe—A Water Supplier's Perspective
Authors: Crum Donald E. , Carns Keith E.
Published: February 2018

In this discussion of Alan R. Berens' article on “Prediction of Organic Permeation Through PVC Pipe” (Journal AWWA, November 1985), Crum and Carns state that field experience at East Bay Municipal Utility District confirms Berens' conclusion that PVC pipe is an effective barrier against chemical pollutants, but they point out that more work is needed to verify this conclusion by using actual PVC pipe sections and gasket materials exposed to organic chemicals with activities in the range of 0.25 to 1.0 where Fickian transport assumptions no longer apply.
Identifying Water Main Leaks With Trihalomethane Tracers
Authors: Hargesheimer Erika E.
Published: February 2018

In this study, the trihalomethanes (THMs) chloroform and dichlorobromomethane, present in chlorinated drinking water, were used as tracer compounds to identify the presence of treated city water in samples of seepage collected at leak sites in the distribution system. Using physical and chemical tests such as alkalinity, hardness, conductivity, and pH, the origin of leakage water samples often could not be identified unequivocally as treated city water, groundwater, or raw river water. Purge‐and‐trap gas chromatographic analysis detected nanogram‐per‐litre to low microgram‐per‐litre levels of chloroform and dichlorobromomethane and can be used to positively identify traces of treated city water. The method was successfully applied to the analysis of distribution system main and service line leak samples.
Predicting the Expansion Behavior of Filter Media
Authors: Dharmarajah A.H. , Cleasby John L.
Published: February 2018

Models that have been used to predict the expansion of filter media are evaluated, and a new correlation, which represents an alternative approach to describing the velocity‐voidage relationship of particulately fluidized systems, is explained. The uses and limitations of this correlation are included.
Roundtable – Applying Health Effects Research
Authors: Burba Foster , Cotruvo Joseph , Golden Robert , Fowle John R. , Burba Foster , Bull Richard J. , Gaston John
Published: February 2018

This discussion took place during the AWWA annual conference in Washington, D.C., on June 25, 1985. Participants were: Richard J. Bull, associate professor of pharmacology and toxicology at Washington State University, Pullman, Wash.; Foster S. Burba, president of the Louisville Water Company, Louisville, Ky.; Joseph Cotruvo, director of the Criteria and Standards Division, Office of Drinking Water, US Environmental Protection Agency, Washington, D.C.; John R. Fowle III, acting director of the Water and Toxic Substances, Health Research Division, Office of Health Research, US Environmental Protection Agency, Washington, D.C.; and Robert Golden, vice‐president of Karch and Associates, Inc., Washington, D.C. John Gaston, senior consultant of CH2M Hill, Emeryville, Calif, was moderator of the panel.
Roundtable – Privatization: Pros and Cons
Authors: Doctor Ronald D. , Noran Paul F. , Gerber Robert A. , Bennett Jeffrey R.
Published: February 2018

The growing interest in the concept of privatization of municipal utility services was discussed at the AWWA annual conference in Washington, D.C., June 25, 1985. Participants were: Ronald D. Doctor of Arthur Young & Company, Seattle, Wash.; Robert A. Gerber of the Hackensack Water Company, Harrington Park, N.J.; and Paul F. Noran of Consumers Water Company, Portland, Maine. Jeffrey R. Bennett of Malcolm Pirnie Inc., White Plains, N. Y., served as moderator.
Private Sector Financing for Water Systems
Authors: Doctor Ronald D.
Published: February 2018

Tax benefits that are currently available for private investors provide the impetus for private sector financing and operation of municipal water and wastewater facilities. Tax reforms now being considered by Congress may greatly affect private investment in the public sector, but whatever form privatization takes in the future, the concept will probably be of increasing importance in restructuring the financing and operation of public water and wastewater utilities. The author outlines various forms of private investments in public facilities and discusses the probable effects of tax reform on each.
Roundtable Comment Clarified
Authors: Burba Foster S.
Published: February 2018

A statement in “Roundtable – Applying Health Effects Research,” (Journal AWWA, January 1986) is clarified. The statement which read: “I would like to see research on contaminants and not rely on the regulator alone” should have read: “I would like to see the drinking water industry engage consultants to interpret the results of research on contaminants and not rely on regulators alone.”
Chlorine Dioxide for Taste and Odor Control
Authors: Walker George S. , Lee Fat Piu (Tom) , Aieta E. Marco
Published: February 2018

A Canadian utility's experience with chlorine dioxide treatment for the prevention of tastes and odors is outlined. The chief complaint was caused by the presence of chlorophenols, formed by naturally occurring organics. Chlorine dioxide treatment successfully eliminated complaints of this type but failed (even in combination with powdered activated carbon) to eliminate completely those complaints arising from urban runoff (hydrocarbons) entering the river upstream of one of the city's two major treatment plant sites. Although significant reduction of taste and odor problems was achieved with increased oxidative power, elimination of all complaints depends on implementation of fixed‐bed activated carbon treatment.
Viewpoint – Industrial Customers: How They Affect Water Utilities
Authors: Ewen Peter K. Mac
Published: February 2018

Peter K. Mac Ewen is executive manager and chief engineer of the Chester (Pa.) Water Authority.
UV Versus Chlorine
Authors: McCarty David L.
Published: February 2018

In response to an earlier article (”Britain's Government May Privatize Regional Water Authorities,” Journal AWWA, March 1986), the author points out the benefits of the British water treatment practice of using ultraviolet light as the primary disinfectant followed by controlled addition of hypochlorite for a distribution system residual.
Experience With Chlorine Dioxide at Denver's Reuse Plant
Authors: Lauer William C. , Lohman Stephen R. , Rogers Stephen E.
Published: February 2018

Researchers at Denver's reuse demonstration plant found that the effectiveness of chlorine dioxide treatment is critically dependent on the performance of the generator. Because high chlorine dioxide yields can be obtained even when excessive concentrations of undesirable by‐products are present, chlorine dioxide yield alone cannot be used as a measure of optimum generation conditions. It is necessary to monitor carefully all of the various chlorine species produced—chlorite, chlorine, and chlorate, as well as chlorine dioxide.
Optimizing Direct Filtration in Brasília
Authors: Bratby John R.
Published: February 2018

Results are presented of laboratory and pilot‐plant studies designed to define the optimum conditions for direct filtration at the Brasilia, Brazil, water treatment plant. The use of ferric chloride was found to offer definite advantages (longer filter runs and lower effluent turbidities) over the use of alum. For the raw waters studied, the use of cationic polyelectrolytes to reduce the metal coagulant dosage was not feasible. It was concluded that preflocculation prior to direct filtration was unnecessary and could even be detrimental to performance. With the coarse filter bed adopted, high backwash rates are required but with lower than normal total volumes of backwash water.
Viewpoint – Drinking Water Quality: How Far Do We Go?
Authors: Gilbert Jerome B. , Price Michael L.
Published: February 2018

Jerome B. Gilbert is general manager and Michael L. Price is senior environmental engineer with the East Bay Municipal Utility District, Oakland, Calif.
A Computer Hardware Primer
Authors: Kroon Joseph R. , Strayer Robert F.
Published: February 2018

The array of available computers and related hardware can be overwhelming—even to individuals who are computer literate. Those who are marginally familiar with or have neither the time nor the desire to keep abreast of rapidly changing hardware technology must rely on outside advice in choosing the right system for their needs. The advice can be taken on blind faith or can be evaluated based on a basic understanding of the characteristics and applications of available computer hardware.
Developing and Applying the Water Supply Simulation Model
Authors: Clark Robert M. , Males Richard M.
Published: February 2018

The Water Supply Simulation Model is a series of computer programs that allows for evaluation of the physical and economic characteristics of a water distribution system in a spatial framework. Development of the model and its application to the water supply system of the village of New Vienna, Ohio, are described.
Water Management in Indian Country
Authors: J. Steven
Published: February 2018

Establishing a legal right to the use of water on Indian reservations has been a major focus of tribal efforts in past decades. This focus is currently expanding to include tribal assertions of control over the regulation and management of water resources in Indian Country. This article discusses ongoing tribal management efforts and how such efforts interface with state water administration in the West.
Public Rights at the Headwaters
Authors: Thorson John E.
Published: February 2018

Steadily increasing emphasis on the aesthetic, environmental, and recreational importance of America's water—particularly in the western states—is calling into question the substance of established water policies. In recent years, courts have tended to recognize and apply the public trust doctrine, which requires government protection of publicly important natural resources. One state, Montana, has undertaken major efforts to integrate public rights into its prior appropriation system by implementing water reservations, facilitating stream access, revising water permit requirements, limiting private appropriation, and controlling state water leasing.
Evaluating Activated Carbons for Removing Low Concentrations of Taste‐ and Odor‐Producing Organics
Authors: Lalezary Shala , Pirbazari Massoud , McGuire Michael J.
Published: February 2018

Equilibrium studies were conducted that used closed‐loop stripping analysis in conjunction with experimental methodologies to evaluate the performance of activated carbons for removing five specific taste‐ and odor‐causing organic compounds that occur at the nanograms‐per‐litre level in water supplies. Both powdered activated carbon (PAC) and granular activated carbon (GAC) proved to be more effective for removing geosmin than for removing 2‐methylisobomeol (MIB). Although chlorine and coagulants had no detrimental effect on the adsorption of organics by PAC, the removal of geosmin and MIB by GAC appeared to be adversely affected by background organic compounds, such as humic substances. The mixing technique used was observed to play a significant role in adsorption.
Modeling TOC Removal by GAC: The General Logistic Function
Authors: Clark Robert M.
Published: February 2018

Various models have been proposed to predict the performance of granular activated carbon (GAC) for single and bisolute systems, including the use of a bed depth service model for interpreting data for operation of adsorption beds to remove total organic carbon (TOC). This model is essentially the simple or symmetrical logistic function. The generalized logistic function is applied to TOC removal and data from GAC, incorporating the inverse of the Freundlich isotherm slope. Thus the model is useful when the breakthrough curve is nonsymmetrical.
Influence of Buffer Capacity, Chlorine Residual, and Flow Rate on Corrosion of Mild Steel and Copper
Authors: Rodolfo A. Pisigan , Singley J. Edward
Published: February 2018

The corrosion rates of mild steel decreased as buffer capacity was increased with pH at constant alkalinity. The corrosion‐promoting effect of ionic strength, however, appeared to predominate over the buffer action in water systems with relatively high total dissolved solids and chloride levels. The enhanced corrosion of mild steel and copper due to a free chlorine residual was related to the strong oxidation potentials of hypochlorous acid and hypochlorite ions. Corrosion rates were faster with higher flow rates, but other hydraulic and environmental factors also need to be considered when corrosivities are compared.
The Effects of Short‐Term Changes in Water Quality on Copper and Zinc Corrosion Rates
Authors: Stone Al , Spyridakis Dimitris , Benjamin Mark , Ferguson John , Reiber Steve , Osterhus Stein
Published: February 2018

In this study, the linear polarization technique was used to evaluate changes in the corrosion rates of copper and zinc surfaces in response to short‐term changes in water quality. This analytical technique can be applied wherever uniform corrosion, as opposed to pitting, is occurring. The parameters investigated included temperature, pH, dissolved oxygen, chlorine residual, flow, and conductivity. All the parameters except flow rate affected copper corrosion rates. Conductivity, dissolved oxygen, chlorine residual, and temperature affected zinc corrosion rates. Reproducible corrosion rates were obtained within a few minutes of the changes in water quality.
Managing Water to Promote Conservation
Authors: Schlenger Donald L. , Miller William H. , Banker Robert F. , Georgeson Duane L.
Published: February 2018

This discussion took place during the annual conference in Denver on June 23, 1986. Participants were Robert F. Banker, partner in the consulting firm of Black & Veatch, Kansas City, Mo.; Duane L. Georgeson, manager of the water system of the Los Angeles Department of Water and Power; and Donald L. Schlenger, director of development and research at the Hackensack Water Company, Hackensack, N.J., and vice‐president for corporate development of United Water Resources, the corporate parent of the Hackensack Water Company. William H. Miller, manager of the Denver Water Department, was moderator.
The Importance of Whiting as a Component of Raw Water Turbidity
Authors: Effler Steven W.
Published: February 2018

Water utilities routinely measure turbidity as an indicator of raw water quality and of the need for treatment. Carbonate precipitate (whiting) represents a significant, and at times dominant, component of turbidity in many hard‐water lakes and reservoirs. The chemistry, driving forces for occurrence, ubiquity, and important features of whiting are presented in this article. It is recommended that utilities that use hard‐water lakes or reservoirs as sources of supply keep apprised of this component of turbidity.
Utility Sharing Is Like Getting Married
Authors: Seibel Gene
Published: February 2018

This article provides some cautionary advice about entering into a sharing agreement among water utilities. The following considerations are addressed: selecting the negotiating team, determining what the contributions of each party will be, and setting charges for services provided.
A Water Resources Audit for Small Communities
Authors: Trauth Kathleen M. , Claborn Billy J. , Urban Lloyd V.
Published: February 2018

Small and intermediate‐sized municipalities frequently lack the resources to carry out effective water management programs. A detailed, “do‐it‐yourself’ audit is now available to such communities to help them identify available water resources, isolate problem areas, set goals, and develop management strategies. Stressing water conservation and reuse, the audit has five goals: to identify the potential for conservation, to reduce volumetric demand, to reduce peak demand in order to postpone the need for water system expansion, to identify potential uses for wastewater and stormwater, and to promote responsible management of water resources. The guide's self‐help format, complete with questions and instructions, enables municipalities to perform an audit without outside assistance and to repeat the procedure when necessary.
Operational Variables and the Release of Colonized Granular Activated Carbon Particles in Drinking Water
Authors: Camper Anne K. , Broadaway Susan C. , LeChevallier Mark W. , McFeters Gordon A.
Published: February 2018

Laboratory and field studies were conducted to determine the impact of granular activated carbon (GAC) drinking water filters and various operational variables on the release of populated filtration medium into finished water. Initially, various filtration media were compared. In laboratory column experiments, the surfaces of GAC, sand, and anthracite particles were populated to the same level with heterotrophic plate count (HPC) bacteria. However, GAC supported greater numbers of the coliform Klebsiella oxytoca than the other two media. A comparison of the media from operating drinking water filters showed that GAC‐filtered water contained particles with attached HPC and coliform bacteria to a greater extent than sand‐ and anthracite‐treated water. The involvement of various operational variables in the increased release of populated fines was evaluated at two facilities. Statistical analyses showed that GAC age does not affect the occurrence of populated fines in filtered water. However, a deeper GAC bed, an increase in applied water turbidity, and an elevated filtration rate were implicated as contributing to the presence of populated filtration medium in drinking water.
Effects of Coagulation on Sludge Thickening and Dewatering
Authors: Knocke William R. , Hamon Jeff R. , Dulin Betsy E.
Published: February 2018

The effects of coagulation mechanism (as influenced by coagulant dosage, influent turbidity, and coagulation pH) on the thickening and dewatering characteristics of aluminum and ferric hydroxide sludges were examined. Sludge thickening and dewatering improved with a reduction in coagulation pH or coagulant dosage or with an increase in influent turbidity. Enmeshment coagulation produced a large floc with a high water content, resulting in poor water removal during dewatering. Adsorption‐charge neutralization coagulation yielded a smaller but much denser floc, which corresponded to greater water removal from the sludge.
Operation and Maintenance of Water Systems in Developing Countries
Authors: Austin John H. , Jordan James K.
Published: February 2018

As the United Nations Drinking Water and Sanitation Decade unfolds, donor organizations have found severe shortcomings in the operation and maintenance of water facilities in less developed countries, thus rendering service to the people less than anticipated. The authors analyze the reasons for inadequate or improper maintenance and offer suggestions for improvement to help meet the goals of the decade. In addition to recommending greater emphasis on operational problems during the design stage, the development of management systems and trained personnel is stressed.
Increasing Water Supplies in the Iberian Peninsula
Authors: Higham Steven
Published: February 2018

Wet and contrasting arid regions characterize the Iberian Peninsula, thus presenting challenges to water planners. Recently, the government of Spain promulgated laws, similar to those in the United Kingdom, that created river basin water authorities. Now, instead of most of the water resources of the country being under the control of large landowners, the resources have been put in the public domain. In addition, many new impoundment projects are under construction or have recently begun operation. These actions are expected to alleviate the difficulties in meeting growing water demands for urban areas as well as for irrigation of farmlands and production of hydropower.
Dead Ends, Red Water, and Scrap Piles
Authors: Rossum John R.
Published: February 2018

The ideas presented in this article contradict some firmly entrenched notions in the water industry. Observations made by the author cast doubt on the infallibility of a negative Langelier index as an indication of the occurrence of red water. Complaints of red water (and perhaps corrosion rates) were reduced when the calcium carbonate precipitation potential‐hydroxide parameter exceeded 1.0.
Removing Manganese From Water at Fredericton, N.B., Canada
Authors: Viraraghavan T. , Winchester E.L. , Brown G.J. , Wasson G.P. , Landine R.C.
Published: February 2018

Fredericton, N.B., maintains 23 active wells that serve as the city's raw water source. Many of these wells have manganese concentrations far in excess of the 0.05 mg/L level recommended by the Canadian drinking water guidelines. An investigation showed that the wells could provide the city's drinking water if treatment for the removal of manganese was installed. After performing pilot studies, the city chose a chlorination‐filtration system for removing the manganese.
Removing VOCs From Groundwater Containing Humic Substances by Means of Coupled Air Stripping and Adsorption
Authors: Amy Gary L. , Narbaitz Roberto M. , Cooper William J.
Published: February 2018

Sequential air stripping and activated carbon adsorption were used for removing trichloroethylene (TCE) and carbon tetrachloride (CT) from a groundwater containing a high background level of organic carbon. Although both compounds were effectively removed by either process, TCE was more amenable to removal by adsorption, whereas CT was more amenable to removal by stripping. Background levels of organic carbon were found to significantly affect adsorption of both TCE and CT, reducing observed sorbent loadings.
Evaluating Treatment Plants for Particulate Contaminant Removal
Authors: Logsdon Gary S.
Published: February 2018

This article is intended to serve as a guide for those who evaluate water treatment plants with the objective of lowering the turbidity of finished water produced from filtration plants in which chemical coagulation is part of the treatment process. Ineffective removal of turbidity may be related to several factors, including the physical condition of the facilities, the hydraulics of treatment processes, the quality of water, and the competence of the operating staff. By preplanning, the evaluation can be conducted in a logical fashion that results in consideration of all necessary and important aspects of the plant and its operation. Descriptions of the proper operation of each component in the process train and pragmatic remedies to improve performance are given.
Technical Note: Proper Use of The Unit mg as CaCO3/L
Authors: Jenkins S. Rod , Morgan Joe M. , Nicol Jean‐Paul
Published: February 2018

The unit milligrams as calcium carbonate per litre (mg as CaCO3/L) should be used consistently to express charge equivalents of a solution. Confusion arises if this unit is used to express carbonate equivalents. Using consistent units (mg as CaCO3/L for charge equivalents), the total carbonate species (CT) was shown to be equal to the sum of the alkalinity and the acidity.
Point of Use and Point of Entry: An Industry Overview
Authors: Cirolia Donna M.
Published: February 2018

This article details what the Water Quality Association (WQA) is, the industry it represents, and its programs. The WQA is an international non‐profit trade association representing more than 2000 member companies that manufacture, sell, and service water quality improvement products for application at the point of use and point of entry. The association's purpose is to promote a consumer's right to quality information, and the growth of the water quality improvement industry. The WQA offers programs in personnel certification, product validation, voluntary advertising guidelines, and industry code of ethics.
Controlling Arsenic, Fluoride, and Uranium by Point‐of‐Use Treatment
Authors: Fox Kim R. , Sorg Thomas J.
Published: February 2018

Arsenic and other inorganic contaminants are found in the water supplies of many small communities. One possible solution for the problem of inorganic contaminants is point‐of‐use treatment, which can be used by individual homes or small communities. Ion exchange, activated alumina, and reverse osmosis point‐of‐use treatment units have been evaluated by the US Environmental Protection Agency, and each system was found to be effective under certain operating conditions. Data from various field projects are presented, along with laboratory data on the removal of specific contaminants.
Debating Recreational Use
Authors: McReynolds Laurent , Olson Kenneth F. , Becker Robert J. , Inhoffer Wendell R.
Published: February 2018

Because of the amendments to the Safe Drinking Water Act (SDWA) requiring filtration of all surface water supplies, recreational use of water supply reservoirs in different parts of the country has become a major concern to the water supply industry. Opinion varies depending upon which area of the country is in question. The West maintains that watersheds should be protected by keeping them isolated from human use, with only wildlife and natural occurrences as sources of contamination. In the East land values are skyrocketing, so it is often not economically feasible to prohibit development. In the Pacific Northwest it is felt that recreation on watersheds and reservoirs used for drinking water supplies should be controlled to the degree necessary to protect the water supply so that applicable standards can be met. There is no one solution to the problem of recreational use of watersheds. There has to be flexibility to determine what works best for specific situations and to allow the utility to take responsibility for product safety rather than imposing rigid methodology.
Replacing Sand With GAC in Rapid Gravity Filters
Authors: Hyde Robert A. , Hill Don G. , Zabel Tom F. , Burke Terry
Published: February 2018

A full‐scale study of the conversion of rapid sand filters to granular activated carbon (GAC) filter‐adsorbers was conducted by the Water Research Centre of Medmenham, UK, at the Church Wilne water treatment plant near Nottingham, England. The objectives were to identify the engineering problems associated with the change and to compare the costs and effectiveness of the GAC system with the rapid sand system. It was found that the GAC removed turbidity and residual coagulants as effectively as sand; the total organic carbon level was lower with GAC‐filtered water; longer filter runs were achieved with GAC filters; and microorganisms of health significance were effectively removed by chlorination after gas treatment.
Ensuring the Security of Public Water Supplies
Authors: Ownbey Pamela J. , Schaumburg Frank D. , Klingeman Peter C.
Published: February 2018

Accidental spills, vandalism, and acts of terrorism have become a growing threat to the safety and security of public water utilities in the United States and abroad. Adequate plans to safeguard supplies include design of facilities with security as a priority and training personnel to recognize and correct potential breaches in security. Two municipal water supply systems in the Pacific Northwest were evaluated in this study to determine the degree of safety and security provided to discourage, detect, and counteract accidental or intentional contamination of their raw and treated water. One is a groundwater system; the other is supplied by surface water. The findings will help increase awareness of the problems confronting utility personnel, regulatory agencies, and design engineers.
Removing Giardia Cysts and Other Particles From Low Turbidity Waters Using Dual‐Stage Filtration
Authors: Horn James B. , Hendricks David W. , Scanlan John M. , Rozelle Lee T. , Trnka Walter C.
Published: February 2018

Dual‐stage filtration (DSF) in packaged form is a good alternative to conventional rapid‐rate filtration for small utilities. The purpose of the study described in this article was to test the effectiveness of DSF for removing Giardia cysts from low turbidity (<;1 ntu), low temperature (near 32°F [0°C]) water. Removals of total coliform bacteria and turbidity were also determined. Two different water sources were tested, with runs up to 35 h in length. Dual‐stage filtration removed >;99 percent of Giardia cysts from waters with a turbidity of <;1 ntu and a temperature of <;46°F (<;8°C), when proper chemical treatment was applied and the system was operated at 10 gpm/sq ft (6.8 mm/s) or less. Removal of total coliform bacteria exceeded 98 percent, and removal of turbidity exceeded 90 percent.
Optimizing the Removal of Geosmin and 2‐Methylisobomeol by Powdered Activated Carbon
Authors: Lalezary‐Craig Shala , Pirbazari Massoud , Dale Melissa S. , Tanaka Theodore S. , McGuire Michael J.
Published: February 2018

The purpose of this study was to determine the conditions under which removal of the taste‐ and odor‐causing compounds geosmin and 2‐methylisoborneol (MIB) by powdered activated carbon (PAC) was most efficient. It was observed that a PAC dosage as low as 5 mg/L could reduce commonly occurring concentrations of these organics (up to 20 ng/L) to acceptable levels. Chlorine and monochloramine residuals appeared to have an adverse effect on the adsorption of geosmin and MIB by PAC, as did the presence of background humic acid. Filtration rate and contact time did not significantly affect removal efficiency.
Polyelectrolyte Characteristics and Flocculation
Authors: Leu Rong‐Jin , Ghosh iganka M.
Published: February 2018

The relationships among the characteristics of cationic polyelectrolytes, mixing conditions, and flocculated particle size distribution were studied in an attempt to develop a rational basis for selecting polyelectrolytes. Charge density was found to be the predominant factor in selecting an optimum dosage of polyelectrolyte for flocculating particles with a primary charge opposite to that of the polyelectrolyte. The initial periods of both rapid and slow mixing are critical in the formation of flocs. Large, strong flocs were obtained with high‐molecular‐weight (>;105) polymers. A simplified model was developed to predict the average floc size based on the molecular weight of the polyelectrolyte and the mixing intensity.
Aluminum‐Fulvic Acid Interactions: Mechanisms and Applications
Authors: Hundt Thomas R. , O'Melia Charles R.
Published: February 2018

The process of fulvic acid (FA) coagulation using aluminum coagulants (alum, polyaluminum chloride, and aluminum chloride) was studied in order to improve FA rehymoval during water treatment. The mechanism of FA removal is directly related to the form of aluminum in solution. Specific conditions and aluminum species that exist during the charge neutralization‐precipitation, adsorption, and simultaneous precipitation reaction mechanisms are discussed, as is the effect of calcium on FA removal.
Advanced Oxidation Processes for Treating Groundwater Contaminated With TCE and PCE: Laboratory Studies
Authors: Glaze William H. , Kang Joon‐Wun
Published: February 2018

Oxidation of trichloroethylene (TCE) and tetrachloroethylene (PCE) with various dosages of ozone or ozone plus hydrogen peroxide was studied in laboratory experiments. The results show that hydrogen peroxide accelerates the oxidation of TCE and PCE by ozone. At peroxide‐to‐ozone dosage ratios of >0.7 (w/w), the process appears to be mass transfer limited. High levels of bicarbonate ion in the groundwater significantly decreased the efficiency of TCE and PCE removal by the ozone‐peroxide system, suggesting that softening prior to oxidation may improve the process.
Getting the lead Out
Authors: McClelland Nina I.
Published: February 2018

The author points out several inaccuracies concerning the health significance of plastic pipe contained in the article entitled “Implementing a Lead Solder Ban” which appeared in the January 1988 Journal AWWA. The National Sanitation Foundation has explored, in detail, the health aspects of plastic pipe and has produced product standards which are continually revised. The NSF offers a certification program for components of plastic piping systems. Those manufacturers wishing to have the NSF stamp of approval must agree to a minimum of three unannounced plant inspections per year and have their product extraction tested by NSF one to three times a year depending on the product.
Central Softening by Crystallization in a Fluidized‐Bed Process
Authors: van der Veen Cornells , Graveland Anthonie
Published: February 2018

Water softening installations at Amsterdam (the Netherlands) Water Supply's two main drinking water treatment plants reduce hardness from 250 to 150 mg as CaCO3/L. In this softening process, pH is raised by adding caustic soda to produce calcium carbonate, which crystallizes on seeding grains in a fluidized bed within a cylindrical reactor. The process, which is not temperature sensitive, allows intensive mixing of water and caustic soda without causing turbidity, and sodium concentrations are not raised above regulatory guidelines. The only by‐product of the process, which is stable and makes few demands in terms of operation and maintenance, is recyclable seed grains layered with calcite. Additionally, increased pH lowers lead and copper solubility by factors of 2 and 5, respectively, and the process can be used to remove heavy metals and phosphates and for denitrification. Total investment and operations cost is equivalent to $4 per household per year, and total savings on household detergents, soaps, energy, and maintenance are equivalent to $25–$40 per household per year.
Trihalomethane Formation in High‐Bromide Lake Galilee Water
Authors: Rebhun Menahem , Manka Josepha , Zilberman Arie
Published: February 2018

A study was conducted of trihalomethane (THM) levels in Israel's national water supply system, which is composed of open channels, open operational reservoirs, and a long, closed conduit. The system derives its water from Lake Galilee. Because of the high bromide concentration in the lake, bromoform is the dominant THM formed. Significant volatilization of THMs was observed in the open channels, and the major production of THMs occurred in the closed conduit. Laboratory investigations showed the formation of relatively high concentrations of THMs at chlorine dosages (2–3 mg/L) and contact times (18 h) similar to those used in the system. The THM formation potential of water from an operational reservoir was significantly lower than that of raw lake water.
Operating a Small Full‐Scale Ion Exchange System for Uranium Removal
Authors: Jelinek Robert T. , Sorg Thomas J.
Published: February 2018

The design and operation of a small full‐scale ion exchange system used to remove uranium from well water in the foothills west of Denver, Colo., are described. Consistent removal of uranium was accomplished by anion exchange treatment at a reasonable cost. Because of a lack of clear regulatory guidelines, disposal of the uranium‐laden regenerant wastewater was the most complicated task associated with this treatment system. Gamma radiation buildup did not appear to be a health concern.
SDWA Amendments: Small Community Compliance
Authors: Long Bruce W. , Stukenberg John R.
Published: February 2018

The 1986 amendments to the Safe Drinking Water Act will substantially affect the treatment and supply of drinking water in the United States. The effects may range from minor operating changes to abandoning treatment and supply in favor of purchasing finished water from a neighboring community or water company. In all cases, the amendments will increase costs for water utilities and, ultimately, their customers.
AWWA Small Systems Program
Authors: Scharfenaker Mark A.
Published: February 2018

To better help small water systems comply with increasingly stringent drinking water regulations, AWWA has established a Small Systems Program as a component of the Technical and Professional Activities Department. All association efforts to assist small systems have been consolidated within the program, the primary objective of which is outreach education through information dissemination and technical assistance at the section level, in cooperation with state regulatory agencies and other organizations assisting small systems. Recent infusions of outside funds have made the fledgling Small Systems Program into a $300,000 operation.
1988 National Water Rate Survey
Authors: Raftelis George A.
Published: February 2018

Developing an effective rate structure for recovering service costs is necessary for operating a water utility on a self‐sustaining basis. This article discusses considerations in selecting an appropriate rate structure, the process of establishing revenue requirements and determining rates, and considerations in comparing water rates. It additionally presents an overview of a 1988 survey of US water rates.∗
Preparing for Tomorrow's Challenges
Authors: Tenny Edward
Published: February 2018

It's time for water utilities to take an assertive, active role in the community—the time for simply reacting to the issues is gone. In Portland, Ore., the bureau of water works has implemented a communications plan that has made the utility an involved public agency. Stretching beyond the obvious goal of informing its consumers about water issues, this utility has become a visible, involved part of its community.
The Role of Bicarbonate in Bacterial Growth in Oligotrophic Waters
Authors: Fransolet Guy , Depelchin Arthur , Villers Gilbert , Goossens Roger , Masschelein Willy J.
Published: February 2018

The growth‐rate constant of six strains of bacteria in oligotrophic waters was found to be highly dependent on the bicarbonate content of the water. This phenomenon explains the problem of bacterial aftergrowth that sometimes occurs in water distribution systems—even when assimilable organic carbon is scarce. The level of organic carbon, however, appears to affect the growth yield. Potassium was observed to be a limiting factor of bacterial growth.
Optimizing Manganese Removal and Washwater Recovery at a Direct Filtration Plant in Brazil
Authors: Bratby John R.
Published: February 2018

Laboratory and pilot‐plant studies were conducted to define the optimum conditions for manganese removal and washwater recovery at the Serra Azul direct filtration plant in Belo Horizonte, Brazil. The inverted sequence of chemical addition recommended—chlorine‐ferric chloride‐lime—offers definite advantages for manganese oxidation. Neither the use of polyelectrolytes nor the recycling of filter washwater was found to be advantageous. Changing the existing deep beds to the optimized shallower beds with coarse media will facilitate washing of the filters. Wash rates that are higher than those originally designed are necessary to adequately clean the filters. Adding anionic polyelectrolyte was observed to improve the settling and specific resistance of the sludge but did not increase thickened or filter cake sludge concentrations. The washwater will be recovered using combined equalization‐settling tanks, and the sludge will be dried in lagoons.
Free Chlorine Versus Monochloramine for Controlling Off‐Tastes and Off‐Odors
Authors: Krasner Stuart W. , Barrett Sylvia E. , Dale Melissa S. , Hwang Cordelia J.
Published: February 2018

In late 1984 the Metropolitan Water District of Southern California changed its primary disinfectant to chloramines to ensure that its member water agencies could comply with the 0.10‐mg/L trihalomethane (THM) regulation. Subsequent taste and odor problems were determined to be an indirect consequence of chloramination, resulting from chloramines’ lesser ability to oxidize odorous compounds released by certain microorganisms. The presence and possible sources of several off‐odorants as well as various treatment schemes to remove them from drinking water are discussed. The effects of these treatment techniques on THM levels in the distribution system are also examined.
Effect of Preloading on the Scale‐up of GAC Microcolumns
Authors: Speth Thomas F. , Miltner Richard J.
Published: February 2018

A previously presented microcolumn scale‐up procedure is evaluated. Scale‐up assumptions that involve equal capacities in microcolumns and field columns are studied in an effort to determine whether preloading activated carbon with a natural water significantly reduces the carbon's capacity for a target compound. The capacities observed in the column studies are compared with isotherms for distilled–deionized water, groundwater, and groundwater with preloaded carbon. Total organic carbon breakthrough in the field column is presented to explain capacity reductions. A simplified version of a mass transfer model and a more complex model are used to predict the pilot‐column results.
Adsorption of Humic Substances in the Presence of Sodium Salts
Authors: Lafrance Pierre , Mazet Michel
Published: February 2018

Inorganic sodium salts were found to enhance the adsorptive capacity of activated carbon for humic substances. The interactions between the salts and the surface of the carbon were investigated as a function of salt type and concentration by zeta potential measurements. At a constant pH, increasing the concentration of humic substances markedly increased the magnitude of the negative value of the zeta potential, whereas increasing salt concentration neutralized the zeta potential. The anion of the salts had little effect on adsorptive capacity or on the change in the zeta potential. Sodium ion concentration is thus the primary factor responsible for the increased adsorption of humic substances, probably via the neutralization of negative charges on both humate molecules and carbon surface functional groups.
Effects of Natural Organic Matter and Calcium on Ozone‐Induced Particle Destabilization
Authors: William B. Dowbiggin , Singer Philip C.
Published: February 2018

The susceptibility of alumina particles to ozone‐induced destabilization in the presence of humic material and calcium was evaluated. It was observed that calcium increased susceptibility to ozone‐induced colloid destabilization. The concentration of ozone required for particle destabilization is a function of the organic carbon concentration as well as the calcium concentration. Experiments without ozonation showed that suspensions with higher concentrations of calcium and lower concentrations of humic material coagulate more readily than suspensions of lower concentrations of calcium or higher concentrations of humic material.
Photo Choice Questioned
Authors: Hetland William T.
Published: February 2018

Comment on October 1988 Confluence article that the Metropolitan Water District of Southern California plans to use ammonium chloride, NH4Cl, as a slower‐acting disinfectant. The writer points out that when chlorine is reacted with ammonia, the monochloramine NH2Cl is formed as the disinfectant.
Turning the Supertanker
Authors: Mannion John B.
Published: February 2018

Mr. Mannion discusses the image of AWWA to some outsiders: mammoth, cumbersome and difficult to change, like a supertanker trying to turn. While Mr. Mannion agrees that AWWA is a big organization and one perceived to be self‐shackled by old‐fashioned traditions and procedures, he contends it is not like a supertanker for neither AWWA nor the industry its serves is a rigid structure nor a single unit. Mr. Mannion wants the organization to attend to the image it projects, because image can help or hinder an organization in its mission. Mr. Mannion asks section members, who may be underestimating their impact on the overall impression created by the association, to look at whether their committees and programs are providing the quality of service and leadership needed, actively implementing the associations' official programs and positions, and representing the industry in their localities and within AWWA's international structure.
Developing a Data Base on Infrastructure Needs
Authors: Clark Robert M. , Goodrich James A.
Published: February 2018

The distribution system is a major capital investment, and utilities must ensure they are getting the highest yield possible on that investment, both in terms of dollars and water quality. Knowing when pipe failure is likely to occur, determining the frequency of repairs, or being able to predict subsequent failures gives utilities additional leverage to tip the economic scales in their favor. Combining cost‐modeling analysis techniques with those of proportional‐hazards models can allow utility personnel to cost‐effectively plan for infrastructure needs on a systemwide basis.
Understanding Corrosion Control Strategies for Lead
Authors: Schock Michael R.
Published: February 2018

This article reviews the factors that should be considered by individual utilities in developing a lead‐solubility control program based on the adjustment of pH, dissolved inorganic carbonate, and orthophosphate. Because of the lack of fundamental and applied corrosion control research and the complexity of the chemical interactions involved, the recommendations included are only best estimates—which can be updated as new data become available. A flow chart is provided to aid in the selection of the best treatment scheme; it is based on the philosophy that chemical models are a useful qualitative guide to the impact of water chemistry on lead solubility but that levels of adjustment should be determined by feedback from pilot testing.
Copper Plumbing Surfaces: An Electrochemical Study
Authors: Reiber Steve H.
Published: February 2018

Electrochemical kinetic parameters on copper plumbing surfaces were investigated under hydraulic and water quality conditions typical of distribution systems. The generally reported values of anodic and cathodic Tafel slopes were found to be inapplicable to plumbing surfaces of drinking water systems. Actual values may differ from reported values by up to twofold. Cathodic Tafel slopes vary strongly with the oxidant–disinfectant constituents of the water, whereas anodic slopes are influenced by corrosion inhibitors and aging of the corrosion scale. The corrosion current (corrosion rate) is affected by these and other parameters, including dissolved oxygen, pH, and chlorine residual. Contrary to some reports, orthophosphates were found to significantly reduce corrosion rates on copper surfaces; however, the phosphate scales that provide this protection are prone to rapid dissolution at low pH.
Disinfection By‐products
Authors: McGuire Michael J. , Orme Jennifer , Glaze William H. , Orme Jennifer
Published: February 2018

This discussion of disinfection by‐products, with an emphasis on toxicology, took place June 22, 1989, during the AWWA annual conference in Los Angeles, Calif. Michael J. McGuire, water quality director for the Metropolitan Water District of Southern California and manager of AWWA's Technical Advisory Workgroup on Disinfection Treatment and By‐products, interviewed Jennifer Orme, chief of the US Environmental Protection Agency Health Effects Assessment Section, and William H. Glaze, chairman of the environmental science and engineering department at the University of North Carolina, Chapel Hill.