bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of chlorine on PAC's ability to adsorb MIB
Authors: Gillogly Thomas E.T. , Snoeyink Vernon L. , Holthouse Andrea , Wilson Claude M. , Royal Earl P.
Published: February 2018

For maximum efficiency of both chlorine and PAC, contact between the two should be eliminated or minimized.

Experiments were conducted in natural and deionized distilled water to establish the extent to which chlorine diminishes the ability of activated carbon to adsorb 2‐methylisoborneol (MIB). The authors determined that the degree of reduction in MIB adsorption capacity was controlled by the amount of chlorine reacted per unit mass of activated carbon. Although the capacity reduction was attributed to the oxidation of MIB adsorption sites, the authors found that chlorine could readily oxidize sites already containing MIB, thereby releasing it back into the aqueous phase. A significant portion of this lost capacity could be recovered by drying the oxidized carbon. To maximize the efficiency of both the chlorine and powdered activated carbon (PAC), contact between the chlorine and PAC should be eliminated or minimized.
Leachability of regulated metals from cement–mortar linings
Authors: Guo Qizhong , Toomuluri Parvati J. , Eckert James O.
Published: February 2018

In a laboratory study, metals leached from cement–mortar linings at levels that suggest water suppliers should be selective when choosing cement for lining pipes.

A laboratory study was conducted to test the leachability of regulated metals from cement–mortar linings inside drinking water pipes. Faucet water of known quality was introduced in the test pipes and maintained in static, pressurized conditions for extended periods of time. Water samples were frequently drawn from the pipes and tested for metals and other water quality parameters during the test periods. Significant amounts of barium, cadmium, and chromium leached out from the cement–mortar linings in two of the three test pipes during the first 14 days of water stagnation. Barium and chromium continued to leach out at detectable levels as the pipes were subsequently refilled. The authors recommend that the water industry be selective in choosing cement for lining pipes.
Divining Trends
Authors: Hoffbuhr Jack W.
Published: February 2018

In his column, AWWA Executive Director Jack Hoffbuhr explains how associations can develop more effective programs for their members by analyzing trends. In particular, Hoffbuhr identifies four key trends that he believes will shape the future of AWWA and its membership ‐ time, increased demand for accountability, technology, and demographics.
Analyzing HAAs and ketoacids without diazomethane
Authors: Xie Yuefeng , Reckhow David A. , Springborg Denise C.
Published: February 2018

New methods accurately analyze HAAs and some ketoacids using an alternative methylating agent in place of the carcinogen diazomethane.

Currently available methods for analyzing haloacetic acids (HAAs) and ketoacids in water generally require the use of diazomethane for sample derivatization. This article proposes methods based on a less toxic, alternative methylating agent. The reagent in both cases is acidic methanol. Side‐by‐side comparison of the proposed method for HAA analysis and method 6251B showed no significant difference. These two methods were also found to give similar method detection limits and spike recoveries. The new O‐(2,3,4,5,6‐pentafluorobenzyl)‐hydroxylamine (PFBHA)‐acidic methanol derivatization analytical method for two ketoacids—glyoxylic acid and pyruvic acid—was found to be comparable to the method using PFBHA‐diazomethane. Additional study is needed to improve methylation efficiency for ketomalonic acid. Work is also needed to further test the proposed HAA method with monochloroacetic acid and brominated haloacetic acids.
Halogenated DBP concentrations in a distribution system
Authors: Chen Wei Jie , Weisel Clifford P.
Published: February 2018

With increasing residence time, concentrations of THMs increased, but concentrations of HANs, HKs, CP, and HAAs decreased.

Increases in the concentration of disinfection by‐products (DBPs) with increasing residence time in distribution systems have been predicted from laboratory studies but not conclusively demonstrated in the field. DBP concentrations were measured in a central New Jersey water distribution system during one year at four locations with nominal water residence times of zero, one, two, and at least three days. The water was disinfected with chloramine so that finished water left the plant with a free chlorine residual of 0.5 mg/L. Concentrations of trihalomethanes (THMs) increased with increasing residence time in the distribution system, but the concentrations of haloacetonitriles, haloketones, chloropicrin, and haloacetic acids decreased with increasing residence time. Concentrations changed more rapidly during warm months than cold months; temperature and chlorine residual were the most important parameters controlling DBP concentrations.
State Revolving Fund Outlook
Authors: Pontius Frederick W.
Published: February 2018

This article discusses the Drinking Water State Revolving Fund (DWSRF) created by the 1996 Safe Drinking Water Act (SDWA) amendments. The article expands on how the funds will provide relief for many water systems that need federal assistance to fund infrastructure improvements in order to comply with the SDWA and related regulations. Topics include: money appropriations; capitalization grants; results of the first drinking water infrastructure needs assessment; and, how the health of the overall federal budget affects the DWSRF.
Greater funding opportunities for drinking water systems
Authors: Bourne James , Blette Veronica
Published: February 2018

The DWSRF commits federal funding to finance infrastructure projects and set‐aside activities to improve US water supplies.

With the passage of the Safe Drinking Water Act (SDWA) amendments on Aug. 6, 1996, Congress established the Drinking Water State Revolving Fund (DWSRF), the first major authorization of federal funding to drinking water systems for the express purpose of ensuring greater public health protection and compliance with drinking water requirements. The DWSRF gives the states great freedom in allocating money for infrastructure needs and other projects and set‐aside activities that enhance managerial and operational quality or promote source water protection. It is up to each state to balance funding set‐aside activities with maximizing the amount of funding available to finance infrastructure improvements. The two‐pronged focus of DWSRF funding reflects the amended SDWA's new emphasis on preventing contamination of drinking water supplies and improving system operations.
TCE adsorption by GAC preloaded with humic substances
Authors: Kilduff James E. , Karanfil Tanju , Weber Walter J.
Published: February 2018

Molecular weight makes a difference—lower‐molecular‐weight substances reduce TCE adsorption.

Adsorption of trichloroethylene (TCE) by activated carbon preloaded with humic and fulvic acids was studied under several conditions in completely mixed batch systems. The authors investigated how molecular weight and molecular‐weight distribution of preloaded humic substances affected subsequent adsorption of TCE. The capacity of carbon to adsorb TCE was most greatly reduced in carbon that was preloaded with humic acid components having molecular weights less than about 1,400 g/mol as polystyrene sulfonate. The adsorption capacity was greatly reduced in carbon that was preloaded with whole humic mixtures in which lower molecular weights predominated. The energy distributions of adsorbent indicate that preloaded compounds preferentially occupy high‐energy sites, making them inaccessible to subsequently encountered TCE.
Combined adsorption—UF process increases TOC removal
Authors: Chang Yu‐Jung , Choo Kwang‐Ho , Benjamin Mark M. , Reiber Steve
Published: February 2018

This process can allow utilities to meet the enhanced coagulation goal for TOC in many cases in which coagulation is not effective.

Addition of heated iron oxide particles (HIOPs) as adsorbents to the feedwater of an ultrafiltration (UF) membrane system significantly increased removal of dissolved organic carbon (DOC) and reduced trihalomethane formation potential (THMFP). Treatment by the HIOP‐UF process met the TOC removal criteria set by the enhanced coagulation provision of the proposed Disinfectants/Disinfection By‐products Rule in all 16 water sources tested, even though those criteria were not met by enhanced coagulation with alum or ferric sulfate in many of the water sources. At pH 6.5 and for the operational conditions studied, 40‐75 percent of the DOC was removed; this percentage might be increased at lower pH or a higher HIOP dosage. THMFP was reduced even more (approximately 5‐10 percent more) than DOC. Although HIOPs tended to reduce membrane fouling, both soft water with extremely high DOC concentrations and hard, alkaline water with moderate DOC concentrations fouled the HIOP‐UF system. Fouling was less severe at lower pH values.
Complying With Risk Management and Process Safety Rules
Authors: Pontius Frederick W.
Published: February 2018

This article discusses the US Environmental Protection Agency (USEPA) risk management program (RMP) regulations and a related Occupational Safety and Health Administration (OSHA) Process Safety Management (PSM) rule that requires comprehensive management systems for the handling of hazardous chemicals by industry and privately operated water and wastewater treatment plants. A table lists the USEPA RMP and federal OSHA PSM thresholds for several common chemicals used at water treatment plants. Erratum ‐‐ The threshold value given in Table 1 (page 18) for chlorine should have been 2,500 lb (1,134 kg) and not 1,500 lb (680 kg).
Committee Report: Membrane processes
Authors:   AWWA Membrane Technology Research Committee
Published: February 2018

Researchers are tackling issues related to larger modules and plants, pretreatment, permitting, and disposal of residuals.

This review focuses on membrane technology research needs in the context of drinking water treatment. It considers practical issues like membrane piloting, scale‐up, residuals discharge, and costs, as well as more fundamental issues like membrane polymers, surface characterization, biofouling, and modeling of the transport of dissolved and particulate species in membrane systems. It is concluded that because the period since this committee's last report has been a fertile one for research, many new questions have arisen on both applied and fundamental issues in the development, use, and understanding of membrane processes in drinking water treatment.
Electrical grounding, pipe integrity, and shock hazard
Authors: Duranceau Steven J. , Schiff Melvin J. , Bell Graham E.C.
Published: February 2018

Electrical currents on metallic water service lines and mains affect corrosion of buried metal piping and can result in random shock hazards for water utility employees.

The practice of using metallic water piping as part of the electrical grounding system of a building has been commonplace for more than 80 years. Modern electronics such as variable‐speed motors, televisions, and computers produce both direct current and alternating current (AC), which can flow along metallic water service piping. When electrical transformers serve multiple buildings, the water services and distribution piping can act as parallel neutral return paths for AC from building electrical systems to the transformers. AC can increase the rate of corrosion of distribution and service piping and create shock hazards for distribution workers. As long as the current remains on the electrically continuous pipe, corrosion is not affected. Corrosion occurs when current leaves the pipe and flows through the earth.
Hydropower valve: a new application for an old device
Authors: James Wesley P.
Published: February 2018

A numerical model can help design engineers incorporate the hydropower valve into conventional systems, potentially reducing energy costs.

The hydropower valve is a combination of a hydraulic ram and a pressure‐reducing valve. Its intended use is to redistribute water between pressure zones in a water distribution system. Energy recovered in releasing water to a lower pressure zone can be used to pump water to a higher pressure zone. Using the hydropower valve can reduce energy consumption in the operation of a water distribution system.
Computing SI and CCPP using spreadsheet programs
Authors: Holm Thomas R. , Schock Michael R.
Published: February 2018

Spreadsheets can automate any chemical equilibrium calculation that can be performed by hand.

Lotus 1‐2‐3® worksheets for calculating the calcite saturation index (SI) and calcium carbonate precipitation potential of a water sample are described. A simplified worksheet illustrates the principles of the method, and a more complex worksheet suitable for modeling most potable water sources is briefly described. Both worksheets include ion pairing and adjustments of equilibrium constants for temperature and ionic strength. For several test cases with a wide range of temperature, alkalinity, pH, and calcium concentration, the worksheet SI values differed <1 percent from those computed by WATEQX. For water quality modeling, spreadsheets have several advantages compared with large equilibrium codes: flexible input and output, ease of maintaining the thermodynamic database, and relatively small memory and mass‐storage requirements. Modeling of archived chemical data is possible through the combination of database management and computational capabilities of many commercially available programs. The worksheets can be obtained from the authors.
Best Management Practices to Protect Groundwater Systems
Authors: Pontius Frederick W.
Published: February 2018

This article discusses how the US Environmental Protection Agency (USEPA) is building on successful state requirements and practices in developing the Ground Water Rule (GWR) for promulgation by November 2000. Best management practices (BMPs), which are required by state regulatory agencies are discussed as a way of giving attention to all aspects of the public water system including well construction, and operation and maintenance.
Risk Management Planning
Authors: Oxenford Moderated by Jeff
Published: February 2018

Water utilities must submit risk management plans for handling hazardous chemicals by June 21, 1999.
Are Operators the Only Ones Who Should Be Certified?
Authors: Gilnack Gerald M.
Published: February 2018

This article discusses how the 1996 Safe Drinking Water Act has put operator certification in the spotlight by requiring that all community water systems meet minimum standards of operator certification. The industry is moving toward state testing and certification of operators based on US Environmental Protection Agency guidelines. Even so, there is still a considerable amount of apathy from the owners of water systems who, as long as their respective systems are in compliance, don't care to be involved. The author outlines six principles that ownership should follow to increase the level of education and awareness of operators, managers, superintendents, and themselves.
Pilot‐plant training for high turbidity
Authors: Norton Russell , Auckly Chet , Raymond Will , Benedict Scott , Goodwill John
Published: February 2018

Treating high‐turbidity water at a pilot plant equips operators to handle real‐world turbidity spikes.

Sierra Pacific Power Company (SPPC), the major water purveyor in northern Nevada, draws its supply from surface water (75 percent) and groundwater (25 percent). The Truckee River, which provides SPPC surface water, is a dynamic raw water source that can change from a nominal turbidity of 5.0‐ntu to >4,000 ntu in as little as 5 hours. To equip its operators with the skills to treat such a variable raw water source, SPPC developed an intensive operator training session. An existing pilot plant was modified to accommodate a delivery system capable of producing a raw water turbidity of 5 ntu to >4,000 ntu in an 8‐hour period. SPPC's training program proved its value Jan. 1, 1997, when a major flood transformed the normally calm Truckee River into a turbulent raw water source with extreme turbidity fluctuations. Applying the experience and knowledge from their pilot training, operators were able to successfully treat the varying raw water conditions and continue delivery of a safe water supply to the cities of Reno and Sparks.
Optimizing enhanced coagulation with PAC: A case study
Authors: Najm Issam , Tate Carol , Selby Douglas
Published: February 2018

Enhanced coagulation plus PAC achieves required NOM removals at minimum cost.

Enhanced coagulation can remove only a finite fraction of the natural organic matter (NOM) in water. Supplementing enhanced coagulation with powdered activated carbon (PAC) increases the removal of NOM and disinfection by‐product (DBP) precursors. The removal of total organic carbon (TOC) and DBP precursors from Colorado River water was evaluated in an experimental matrix of jar tests using four ferric chloride dosages and four PAC dosages. On the basis of the chemical dosages used, the cost of each combination of coagulant and PAC addition was estimated. For a given TOC removal goal, a particular combination of ferric chloride and PAC dosages resulted in the lowest chemical costs. The analysis also indicated that this same dosage combination would produce the least sludge at the water treatment plant. This study shows that the combination of a chemical coagulant and PAC can be more cost‐effective than a chemical coagulant alone for meeting the requirements of Stage 1 of the Disinfectants/DBP (D/DBP) Rule. In addition, the combination of a chemical coagulant and PAC may be a cost‐effective alternative to granular activated carbon for meeting the requirements of Stage 2 of the D/DBP Rule.
Committee Report: Gasket materials
Authors:   AWWA Committee on Gasket Materials for Water Works Service
Published: February 2018

Elastomers' use‐specific sensitivity to chloramine makes it difficult to develop test methods, pass‐fail criteria, and a standard appropriate for all rubber components.

Rubber components are used extensively in water distribution systems, and their long‐term performance is of concern to water utility engineers. Thus, AWWA member utilities asked the AWWA Research Foundation (AWWARF) to investigate how chlorine and chloramine affect these components. In 1992, AWWARF commissioned a study to evaluate the effects of chlorinated and chloraminated water on two types of elastomers: generic specimens of known formulations and sheet stock of unknown formulations. This report responds to the AWWARF research, which concluded that chloraminated waters are more detrimental to most elastomers than waters with equivalent concentrations of chlorine. It also enumerates proposed actions, including developing pass‐fail criteria, related to these findings and explains why it is not currently feasible to develop an AWWA standard for all gaskets used in chloraminated waters.
Lessons From Down Under
Authors: Hoffbuhr Jack W.
Published: February 2018

In his column, AWWA Executive Director Jack Hoffbuhr discusses Sydney, Australia's recent problems with Cryptosporidium in the water supply. He briefly talks about the different approaches that the United Kingdom and the United States are taking to guard against microbiological contaminants, and urges Australian counterparts to fashion a program for controlling Cryptosporidium and other pathogens based on public health principles rather than political expediency.
CCRs: Help Is Coming for Small Systems
Authors: Knotts Jamie
Published: February 2018

This article discusses the Consumer Confidence Report (CCR) required by the 1996 amendments to the Safe Drinking Water Act. Specifically, the article discusses computer‐based report‐writing aids, which will assist utilities in presenting their data. AWWA's CCR Builder, a Web‐based tool, and the National Rural Water Association's (NWRAs) CCR tool are both discussed.
Conferences: Worthless or Worth It?
Authors: Miller Ellen G.
Published: February 2018

Conferences offer one‐stop learning and networking opportunities. State and national conferences can offer a top‐notch return on your system's dollars. Sessions and exhibits come first in the ranking of benefits, but informal discussion and networking run a close second. Getting names, telephone numbers, and email addresses puts you in touch with folks who work in circumstances similar to yours.
Safeguarding distribution system integrity
Authors: Trussell R. Rhodes
Published: February 2018

Keeping a residual is important, but it is only one of many actions needed to safeguard the integrity of the distribution system.

When water utilities began using chlorine for primary disinfection, a residual in the distribution system came with it. Regulations have made the distribution system residual an increasingly important requirement in many parts of the world. However, many groundwater systems commonly operate without a residual, and several European utilities now operate with no residual in treated surface water. This article examines the reasons often cited for maintaining a disinfectant residual and discusses the merits of alternative residual disinfectants.
US regulations on residual disinfection
Authors: Shaw Susan E. , Regli Stig
Published: February 2018

Preserving distribution system water quality and protecting public health depend on regulations as well as a whole‐system approach.

Most community water systems in the United States disinfect their water. However, only surface water systems are currently required to provide a disinfectant residual in the distribution system. This article reviews existing regulations, including the Surface Water Treatment Rule and the Total Coliform Rule, for maintaining a disinfectant residual and outlines their requirements. It also discusses forthcoming and long‐term regulations and how they may affect water treatment and distribution system water quality, operations, and maintenance.
Confessions
Authors: Hoffbuhr Jack W.
Published: February 2018

In this column, AWWA Executive Director Jack Hoffbuhr describes his experience with writing regulations and guidance for the Safe Drinking Water Act. He concludes from his experience with writing guidance that it has two major downsides: it often does not get the thorough review from stakeholders that it needs; and, it is often substituted for the regulation by well‐meaning folks trying to do their jobs. This can result in the imposition of more requirements than the regulation intended, creating even more confusion. He points out that the US Environmental Protection Agency has shown a willingness to work with stakeholders to facilitate regulatory development and implementation. He urges that this partnership must continue as the guidance is developed to help prevent further confusion.
More Regulations on the Horizon
Authors: Raysby Lisa
Published: February 2018

This column discusses some of the new regulatory requirements affecting small water systems, including: system capacity; source water assessment and protection programs; operator certification; Consumer Confidence Reports (CCRs); and, the Ground Water Rule (GWR). As far as finding resources to fund compliance efforts, states have access to the drinking water state revolving fund to provide technical assistance to small systems.
ICR protocol: alternative treatment of parasite sample data
Authors: Atherholt Thomas B. , Korn Leo R.
Published: February 2018

Alternative data analysis and reporting methods may help avoid flaws inherent in the current ICR protocol.

As part of the Information Collection Rule (ICR), the US Environmental Protection Agency (USEPA) has specified an immunofluorescence assay protocol for handling and reporting Giardia cyst and Cryptosporidium oocyst data. The protocol is flawed in several respects, primarily the extrapolation of cyst and oocyst counts in a small “equivalent sample volume” analyzed to a 100‐L volume, the conversion of zero counts to less than one count, and the reporting of the data collected in this manner. Such data conversion and reporting can introduce data analysis problems. USEPA's draft method 1622 for analyzing water samples for Cryptosporidium does not specify how parasite count data should be treated or analyzed. If ICR method data handling and reporting specifications are followed, parasite concentration data obtained using method 1622 could also be inaccurate. The authors propose an alternative procedure for analyzing and reporting ICR parasite data.
Capacity development: the small system perspective
Authors: Soelter Alan D. , Miller Ellen G.
Published: February 2018

A sampling of state agencies and midsized and small systems uncovered concerns about capacity development provisions and suggestions for resolving these concerns.

A brief two‐part study was undertaken to find out what midsized and smaller systems know about capacity development and what they need in order to comply with SDWA requirements. Three paradoxes emerged. (1) Capacity development provisions bring both more risk and more opportunity. (2) The provisions take more time but also save time. (3) The provisions allow states flexibility while requiring them, as a condition of receiving 100 percent of their Drinking Water State Revolving Fund allotment, to help systems acquire and maintain capacity. Suggested steps to resolve these paradoxes are presented for consideration by state primacy agencies and other groups.
Benefit–cost analysis of the Stage 1 D/DBP Rule
Authors: Odom Rosemarie , Regli Stig , Messner Mike , Cromwell John , Javdan Maggie
Published: February 2018

Protecting the public from exposure to DBPs and the subsequent risk of certain cancers must be balanced with controlling water treatment costs.

In 1992–93, the US Environmental Protection Agency (USEPA) convened a negotiated rulemaking process under the Federal Advisory Committee Act (FACA) to develop a consensus approach to simultaneously addressing potential health risks posed by disinfection by‐products (DBPs) and waterborne pathogens. The fact that inadvertent risk–risk tradeoffs might be made between protection from DBPs and protection from microbial pathogens complicates the process. It is further complicated by uncertainties that affect the assessment of both risks. The regulatory‐negotiations committee devised a staged approach to regulation that a second FACA committee finalized in 1996–97. This article summarizes the DBPs side of the benefit–cost analysis that was developed during these processes and later refined by USEPA to more fully address uncertainties regarding the rule's benefits.
Crafting a Regulation for Radon in Drinking Water
Authors: Pontius Frederick W.
Published: February 2018

Radon is a naturally occurring radioactive gas. The US Environmental Protection Agency (USEPA) was required by the 1986 Safe Drinking Water Act amendments to regulate radon in drinking water. A proposed maximum contaminant level (MCL) of 300 pCi/L water was published July 18, 1991. Since then, regulation of radon in drinking water has been the subject of continuing debate, congressional action, and, more recently, USEPA efforts to craft a proposed regulation. This article examines key issues in anticipation of USEPA's proposed rule.
Uses of protozoan monitoring data
Authors: Clancy Jennifer L. , Hansen Judi
Published: February 2018

Utilities around the world monitor for pathogens, but many find the data too unreliable to be used as a basis for making water quality or public health decisions.

European and North American water utilities and regulatory agencies were surveyed to determine current drinking water monitoring practices for Giardia cysts and Cryptosporidium oocysts and to ascertain how the monitoring data are used. Responses from 27 agencies indicated that monitoring is still generally voluntary, except in the case of disease outbreaks, during which regulatory agencies can require testing. The data are used to study the occurrence of protozoa in source water, to assess treatment efficiency, and to support investment planning. Rarely are these data used to make public health decisions and then only in conjunction with other data such as weather–watershed changes, treatment information, other water quality parameters (i.e., turbidity), and presence of disease in the community. The primary reason protozoan monitoring data are not used in public health decision‐making is lack of reliability of the data quality.
Potable use of reclaimed water
Authors: Crook James , MacDonald Jacqueline A. , Trussell R. Rhodes
Published: February 2018

Indirect potable reuse is a viable application of reclaimed water if indicated by site‐specific assessments that include contaminant monitoring, health and safety testing, and system reliability evaluation.

The National Research Council released a report in 1998 that evaluated the feasibility of augmenting drinking water supplies with highly treated reclaimed water. The report concluded that indirect potable reuse of reclaimed water (i.e., using reclaimed water to augment a potable water source before treatment) is viable and that direct potable reuse (i.e., introducing reclaimed water directly into a water distribution system) is not viable. Although recent health‐related research has uncovered no adverse effects, such health data are sparse, and the methods for such research are limited. Consequently, the results cannot be extrapolated to potable reuse in general. Thus, each indirect potable reuse project should be implemented only after a thorough, project‐specific assessment of health concerns and measures to mitigate them. Finally, potable reuse should only be considered in communities in which other efforts—water conservation, development of new water sources, and nonpotable reuse—cannot cost‐effectively meet the communities' needs. This article describes the council's recommendations for ensuring the safety of water systems that augment raw water sources with reclaimed water.
Setting reclaimed water rates
Authors: Cuthbert Richard W. , Hajnosz Ann M.
Published: February 2018

Reasonable rates play a large role in encouraging public support for a reclaimed water system.

The use of reclaimed water to offset potable water demands is becoming more popular. Setting reclaimed water rates and charges is an important factor in establishing and operating a reclaimed water system. This process is complex because it often costs more to provide reclaimed water than it does to provide potable water even though reclaimed water is generally of lower quality. The long‐term benefits of reclaimed water, however, are significant enough that most utilities want to encourage its use. To illustrate how a utility should price reclaimed water in order to encourage its use, this article summarizes results of a survey of rates and pricing strategies used by 23 US utilities that operate reclaimed water systems. In addition, strategies for setting reclaimed water rates are discussed based on a case study developed for the city of Tucson, Ariz., Water Department. In some circumstances, sound economic justifications exist for pricing reclaimed water below its embedded cost‐of‐service level.
Reduction of bromate in a BAC filter
Authors: Kirisits Mary Jo , Snoeyink Vernon L.
Published: February 2018

Water treatment plants already using ozone and GAC filters can readily implement this method of removing bromate.

Bromate removal was observed during biologically active carbon (BAC) filtration. Microorganisms in the BAC reduced bromate to bromide, although the formation of other intermediate species is possible. The effects of dissolved oxygen (DO) concentration, nitrate concentration, and empty bed contact time (EBCT) on microbial bromate reduction were examined. Oxygen and nitrate, common microbial electron acceptors, hindered bromate reduction. For example, at an influent DO concentration of 2 mg/L in a BAC filter with a 25‐min EBCT, bromate was reduced by 86 percent at an influent nitrate concentration of 0.2 mg/L, whereas it was reduced by 76 percent at an influent nitrate concentration of 5.1 mg/L. In general, lengthening the EBCT increased bromate removal. Biological bromate removal in a conventional ozone–granular activated carbon plant was deemed possible if the DO concentration in the BAC filter is controlled.
Emerging Microbes 101: A Basic Course
Authors: Murphy Sue
Published: February 2018

This paper discusses the causes and effects of contamination, waterborne disease, and microbial detection methods. It points out how important source water protection is to limiting and preventing contamination.
Effect of filter media on cyst and oocyst removal
Authors: Swertfeger Jeff , Metz Deborah H. , DeMarco Jack , Braghetta Anne , Jacangelo Joseph G.
Published: February 2018

Spiking studies underscore the important role filtration plays in removing protozoa from surface water.

As part of a pilot‐scale examination of filtration media at the Cincinnati (Ohio) Water Works, heat‐inactivated Giardia cysts and Cryptosporidium oocysts were spiked into surface water that had already undergone coagulation and sedimentation. This spiked water was then introduced into pilot‐scale filters containing sand only, typical dual anthracite–sand, and deep dual anthracite–sand media configurations. All of the media types used in this study demonstrated similar removal capabilities, with average cyst removal ranging from 2.7 to > 4.5 logs and average oocyst removal of 2.7–3.9 logs. Endospore and polystyrene bead removals were similar to those of the protozoa, but turbidity and particle counts demonstrated substantially less removal capability.
This Old Plant Still Flies
Authors: Sweed Walter
Published: February 2018

This paper describes the process of rehabilitating Stewart Field Water Filtration Plant, a 57 year old diatomaceous earth system located at Stewart Air Force Base in New Windsor, New York. Pumps and monitors were replaced, the microflocculation upflow absorption clarifier was adjusted by moving the aluminum sulfate injection point back as far as it would go and adding an inline flash mixer to the setup, a submersible pump was installed in one of the holding wells to reduce holes and tears from monthly manual acid washes, and the diatomaceous slurry feed line injection points were relocated.
Water utilities as integrated businesses
Authors: Heller Miriam , Von Sacken Eric W. , Gerstberger Richard L.
Published: February 2018

Information technology is helping utilities achieve a competitive edge today and move closer to ecoefficiency.

With privatization, managed competition, deregulation of the power industry, and increasing environmental legislation, water utilities must aspire to more than high levels of service and reliability. They must seek competitive levels of service and reliability. To reach this goal, water providers have to balance financial considerations and consumer requirements. They must make optimal use of production processes and support systems, ultimately achieving ecoefficiency, i.e., economically efficient use of resources with other businesses. Information technology (IT) plays a key role in achieving this climate of widespread efficiency by (1) enabling the integration of computer systems, information, human resources, and natural resources; (2) defining common performance measures; and (3) optimizing performance. Three existing paradigms—the utility communications architecture, utility business architecture, and industrial ecology—can serve as structured applications for efficient IT planning and deployment at the plant, utility, and regional levels.
Sizing residuals drying beds
Authors: Cornwell David A. , Vandermeyden Carel
Published: February 2018

Pilot tests and this design model can correctly size nonmechanical dewatering processes.

Design criteria were developed for nonmechanical dewatering of water treatment residuals. First, certain physical properties were determined for residuals high in alum, ferric chloride, or polyaluminum chloride. Laboratory tests that characterized these properties showed that capillary suction time and time to filter correlated very well; either could be used in the laboratory to test residuals' drainage characteristics. Pilot‐ and full‐scale evaluations at five utilities followed. Drainage characteristics predicted by pilot tests using 2‐in.‐ (50‐mm‐) diameter columns and measured in full‐scale sand drying beds correlated closely. This work showed that pilot tests can allow good prediction of full‐scale performance and, thus, the development of useful design parameters. Three models illustrate the proper sizing of sand drying beds, solar drying beds, and dewatering lagoons. These models allow a utility to determine the area required for each dewatering method on the basis of pilot data, local climatological data, and—most important—monthly residuals production. This article presents the test procedures and modeling required for utilities to size and design nonmechanical dewatering systems.
Technology Resources for Small Systems
Authors: Lahlou Mohamed , Saxena Sanjay
Published: February 2018

This article discusses different sources available to assist Small Water Systems in meeting Safe Drinking Water Act requirements, which include: US Environmental Protection Agency (USEPA) guidance documents; National Drinking Water Clearinghouse (NDWC) RESULTS [Registry of Equipment Suppliers of Treatment Technologies for Small Systems]; NDWC tech briefs; USEPA/NSF ETV Program; USEPA technical assistance centers (TACs); American Water Works Association's Small Utility Network (SUN); and the National Rural Water Association Services.
Unregulated Contaminant Monitoring
Authors: Pontius Frederick W.
Published: February 2018

The US Environmental Protection Agency set new requirements for unregulated contaminant monitoring Sept. 17, 1999. These requirements will replace those in the existing rule Jan. 1, 2001, when the new Unregulated Contaminants Monitoring Rule becomes effective. Existing requirements apply until Jan. 1, 2001, to large systems that serve more than 10,000 people. Provisions of the new rule are summarized here.
Rehabilitation of 1940s water mains
Authors: Hall Bruce B.
Published: February 2018

In‐place relining of rusted water mains restored aesthetically high‐quality water.

Water District No. 1 of Johnson County, Kan., rehabilitated sections of unlined cast‐iron pipe installed in the 1940s. Customers complained to the district about rusty water delivered to their homes. After two options were investigated, the cast‐iron pipes and fittings were cleaned and lined in place with cement mortar. The water district and the customers that it serves are both pleased with the result: elimination of rusty water at a reasonable cost.
Assessing Individual Filter Performance
Authors: Pontius Frederick W.
Published: February 2018

Under the continuous filter monitoring requirements of the Interim Enhanced Surface Water Treatment Rule (IESWTR), a water system may have to prepare a filter profile, perform an individual filter self‐assessment, or conduct a comprehensive performance evaluation (CPE). Individual filter requirements under the IESWTR are given in the guidance manual. Requirements for continuous filter monitoring for turbidity and the CPE provisions have been reviewed. Assessing individual filter performance is discussed in this article.
Occurrence of MTBE in drinking water sources
Authors: Gullick Richard W. , LeChevallier Mark W.
Published: February 2018

A recent survey investigates the prevalence of MTBE in drinking water supplies and evaluates the efficacy of treatment for MTBE removal.

Methyl tertiary butyl ether (MTBE) is of concern to the drinking water supply profession because of its strong taste and odor effects, potential risk to human health, tendency to migrate rapidly in groundwater, and resistance to conventional water treatment processes. An occurrence survey was performed from 1997 to 1998 to assess the prevalence of MTBE in surface and subsurface drinking water supplies. The survey examined 342 wells in 17 states, and MTBE was detected at least once in 30 wells (~8.8 percent). All samples were below the US Environmental Protection Agency's taste and odor advisory level of 20 μg/L. In addition, 92 surface water sites in 12 states were evaluated, and MTBE was detected at least once at eight sites (~8.7 percent). The highest concentration (25.1 μg/L) was detected downstream from a known gasoline release. Aeration removed up to 76 percent of low concentrations of MTBE, but activated carbon adsorption was relatively ineffective.
Financing Small Water Systems in the 21st Century
Authors: Ytell Elizabth , Butkus Pete
Published: February 2018

This column discusses funding for improvements to small water systems. It is suggested that a rate study should be done in the very beginning of the planning process along with other important points that are listed. Several federal and state sources of funding are given.
Use of polyphosphate in corrosion control
Authors: Cantor Abigail F. , Denig‐Chakroff David , Vela Richard R. , Oleinik Mark G. , Lynch Daniel L.
Published: February 2018

Case studies from three Wisconsin utilities found that polyphosphate blends used for corrosion control led to increased metal concentrations in the water.

When polyphosphate blends are added to water systems under certain conditions, leaching of pipe metal into the water may be significantly increased rather than decreased. Case studies of three Wisconsin water utilities uncovered possible negative consequences of using polyphosphate for corrosion control. These experiences suggest that water providers must exercise caution when adding polyphosphate to drinking water systems. Utilities should conduct off‐line tests before using polyphosphate, and full‐scale systems should be frequently monitored after polyphosphate addition. More research is needed to define the proper use of polyphosphates and to investigate alternatives to polyphosphates.
Removing arsenic from groundwater
Authors: Chwirka Joseph D. , Thomson Bruce M. , Stomp John M.
Published: February 2018

To meet the new arsenic MCL, Albuquerque, N.M., will construct its first arsenic treatment facility.

Three treatment technologies for removing arsenic from groundwater in Albuquerque, N.M., were compared: ion exchange (IX), iron hydroxide coagulation followed by microfiltration (C/MF), and activated alumina (AA) adsorption. For an 8,700‐m3/d (2.3‐mgd) arsenic treatment facility, capital costs of the three processes were similar: $5.2 million, $4.1 million, and $4.6 million, respectively. Annual operations and maintenance costs were $447,000, $273,000 and $444,000, respectively. The principal differences were the result of large salt requirements for the IX process and the need to reduce the pH to 6 for AA adsorption, followed by base addition to stabilize the water. The C/MF system was selected for a demonstration facility in Albuquerque.
Freeze‐thaw residuals conditioning
Authors: Parker Philip J. , Collins Anthony G. , DeWolfe James R.
Published: February 2018

Freeze–thaw conditioning can reduce residuals disposal costs.

Freeze–thaw conditioning is an effective way to process water treatment residuals. For many years the process has used natural out‐of‐doors freezing, but development of mechanical processes has been hindered by a lack of fundamental information about the process. This article presents the results of experiments performed to study the effects of initial solids content, curing time, and freezing rate on dewaterability of residuals from five water treatment facilities in the northeastern United States. Dewaterability of all residuals sharply increased following freeze–thaw conditioning. In the experimental procedure used, dewaterability following freezing and thawing was independent of rate. However, initial solids content and curing time strongly affected dewaterability, which was best for residuals frozen at high solids content and cured for long times. Cake solids contents > 40 percent w/w were achieved. Generally, the process was most successful for residuals that exhibited the best dewaterability before freeze–thaw conditioning. Finally, cost‐optimum freezing conditions were determined.
State Revolving Loan Fund Outlook
Authors: Pontius Frederick W.
Published: February 2018

This article discusses the Drinking Water State Revolving Fund (DWSRF), created by amendments to the Safe Drinking Water Act (SDWA) in 1996. Funding assistance for projects include: the costs of infrastructure needed to achieve or maintain compliance with SDWA requirements and to protect public health; capitalization grants to the states, which in turn can provide low‐cost loans and other types of assistance to eligible systems; and, capitalization grants for administrative costs and program funding for capacity development and source water protection.
Energy indicators and savings in water supply
Authors: Pelli T. , Hitz H.U.
Published: February 2018

Indicators that are easy to apply can assess the efficiency of energy usage.

This article describes two indicators that evaluate the energy consumption of a water supply system. The structure indicator describes how the spatial distribution of users and water sources influences energy consumption. It is defined as the minimal energy that is necessary to lift a cubic metre of water to users and to give it a pressure of 6 bar (88 psi), a typical water pressure at the tap. In turn, minimal energy can be calculated as the difference between the potential energy of the delivered water (for some unit of time) and the potential energy of the same quantity of water at the source. The quality indicator is defined as the ratio of the effective energy used (during the same unit of time) and minimal energy. It shows the efficiency of the entire water supply system, which is determined by factors such as the efficiency of pumps, locations of reservoirs, and water loss in the network. The results of calculations are used to establish a relationship between the value of the quality indicator and the energy‐reduction possibilities; this relationship permits a water supplier to evaluate how economically a water supply system uses its energy.
Insurance issues surrounding pipe‐related liabilities
Authors: Sylvester John M. , Reiter Thomas M. , Waldron John T.
Published: February 2018

Court decisions and other weapons in the legal arsenal can help policyholders obtain coverage and avoid exclusions for pipe‐related liabilities.

When a plumbing system fails and causes damage, pipe‐related liabilities can affect numerous policyholders, from pipe manufacturers, designers, and installers to public and private users of the product. The authors examine a number of coverage issues raised by insurers in response to claims related to pipe liability. These questions include when coverage is triggered and which insurers are liable for pipe problems that develop over many years. In addition, the authors detail arguments that policyholders can use to defeat the principal exclusions raised by insurers and describe the recourses available to compel insurers to cover pipe‐related liabilities. Although a final determination of coverage ultimately depends on the specific language of the policy and underlying facts of each case, many of the defenses and limitations raised by insurers can be overcome if policyholders vigorously pursue their rights to coverage.
Choices
Authors: Hoffbuhr Jack W.
Published: February 2018

In his column, AWWA Executive Director Jack Hoffbuhr discusses the importance of building a reliable water system for the future that will be based on trusting water utility professionals to consistently act to protect the public health of their consumers.