bluuebunny/crossref_metadata_2025 huggingface dataset:
An analysis of monitoring data for the Stage 1 Disinfectants/Disinfection Byproducts Rule
Authors: Shoaf David R. , Singer Philip C.
Published: February 2018

In this research, disinfection by‐product monitoring data for the period between Jan. 1, 2004, and Sept. 30, 2005, were obtained for 113 North Carolina water systems serving 10,000 or more customers. Data were analyzed to assess compliance with the trihalomethane (THM) and haloacetic acid (HAA) regulatory requirements of the Stage 1 Disinfectants/Disinfection Byproduct Rule (D/DBPR) as well as potential future compliance with the Stage 2 D/DBPR. Analysis of the data indicated that relatively few systems had experienced noncompliance with the Stage 1 D/DBPR. Of the 452 systemwide running annual averages (SRAAs) available for the seven quarters of data analyzed, only eight of the SRAAs exceeded the Stage 1 maximum contaminant level (MCL) for total THMs, and eight exceeded the MCL for the five regulated HAAs. An examination of bromine incorporation patterns among the THM and HAA species suggests that omission of several of the brominated HAA species in the reported HAA measurements in accordance with regulatory requirements ignores a significant portion of HAA exposure in some North Carolina systems.
Combined chlorine dissipation: Pipe material, water quality, and hydraulic effects
Authors: Mutoti Ginasiyo (Ignatius) , Dietz John D. , Arevalo Jorge , Taylor James S.
Published: February 2018

Effects of water chemistry, temperature, pipe material, and hydraulic conditions on total chlorine dissipation were investigated using laboratory‐ and pilot‐scale experiments. Chlorine demand in the bulk phase depends on water chemistry, and the bulk‐phase dissipation constant (kb) generally increased with increasing dissolved organic carbon. A 10°C rise in temperature resulted in a threefold increase in kb. Pipe material significantly influenced total chlorine dissipation rates in the following order: galvanized iron > unlined cast iron > polyvinyl chloride (PVC) > lined cast iron. Total chlorine consumption predominantly occurred at the wall surface in small‐diameter unlined cast‐iron and galvanized‐iron pipes and predominantly in the bulk phase for lined cast‐iron and PVC pipes. The mass transfer coefficient (kf) and the overall dissipation constant (K) increased with increasing Reynolds numbers. The wall constant (kw) is an intrinsic pipe property and is therefore a true constant; an increase in kw with increasing Reynolds number was observed. However, this may be attributed to dynamic changes in particulate surface area associated with release of corrosion products from the pipe surface.
Economic and Design Considerations for Membrane Filtration at a Lime Softening Plant
Authors: Bernard Michael , Harrison Sam
Published: February 2018

This article discusses the rehabilitation of a lime softening‐mixed media filtration plant with the city of Murfreesboro (Tennessee) Water and Sewer Department (MWSD). The article discusses the process of evaluating which type of membrane filtration system would best fit the city's needs and the configuration in which the membranes should be placed. The two options that were considered include: a vacuum‐driven, immersed membrane technology; or, a pressure‐driven, containerized design. Also at issue was whether the membranes should be installed before or after granular activated carbon (GAC) filtration. Membrane flux, construction costs, and membrane pilot‐testing are discussed.
Treatment Optimization—Providing More Effective Multiple‐barrier Protection
Authors: Barr Pamela
Published: February 2018

This article begins by providing a brief overview of the U.S. Environmental Protection (USEPA) Agency Office of Ground Water and Drinking Water's Technical Support Center (TSC) in Cincinnati, Ohio, and its treatment optimization program for enhancing water system multiple‐barrier protection. The program started in 1989, focusing on the development of comprehensive performance evaluation (CPE) to assist filtration plants in complying with the turbidity requirements of the then recently promulgated Surface Water Treatment Rule (SWTR). Development of the CPE procedures showed that most water systems could easily comply with the SWTR using existing facilities while they also achieved optimized levels of performance. TSC works through four USEPA regional offices to facilitate development of area‐wide optimization programs (AWOPs) in 21 states. Treatment optimization fundamentals are discussed, along with the value of optimization.
Inside the Water Resources Development Act of 2007
Authors: Pontius Fred
Published: February 2018

The Water Resources Development Act (WRDA) of 2007 became law November 9, 2007 after both houses of Congress voted to override a presidential veto. A pork‐barrel bill by design, members of Congress seeking particular project authorizations exerted tremendous pressure to pass the bill. The legislation authorizes flood control, navigation, and environmental projects and studies by the U.S. Army Corps of Engineers (the Corps). If fully funded,WRDA 2007is estimated by the Congressional Budget Office (CBO) to result in about $11.2 billion of spending from 2008 to 2012 (CBO, 2007). An additional $12 billion would be needed over the 10‐year period beyond 2012, with some construction and operations costs continuing or commencing even after the first 15 years. This article describes the WRDA as federal legislation that is the main vehicle for authorizing water projects undertaken by the Corps. It is also the vehicle used to implement policy changes in Corps water resource projects and programs. The article discusses how WRDA legislation was developed, project funding, and the nine titles of the 2007 WRDA.
Conserve to Enhance—voluntary municipal water conservation to support environmental restoration
Authors: Schwarz Andrew , Megdal Sharon B.
Published: February 2018

Conserve to Enhance offers an innovative municipal water conservation mechanism designed to motivate consumers to conserve water and set aside funds to purchase water for environmental needs. The concept and program elements were developed with the collaboration of utility representatives, elected officials, interested citizens, as well as more than 40 experts in water and environmental concerns. Under the proposed voluntary program, a baseline water use is established for participants on the basis of actual water consumption. Even if participants reduce their water consumption, they agree to continue to pay this baseline amount, with any monetary savings accrued by their conservation efforts going to the Conserve to Enhance program. These funds are then used to purchase water for environmental enhancements such as irrigation for revegetation efforts. The authors offer a set of considerations and recommendations for the potential development of a program, including strategies for measuring and accounting for conservation, water utility involvement, and development of decision‐making bodies.
Detecting Changes in Water Quality Data
Authors: McKenna Sean A. , Wilson Mark , Klise Katherine A.
Published: February 2018

Timely deployment of contaminant warning systems requires on‐line sensors and advancement of data analysis and decision support systems to accurately detect water quality changes. As a demonstration of event detection in water quality data, three water quality change‐detection algorithms were developed and used to detect changes in water quality observed at four locations within a distribution system. Each data set was “spiked” with simulated anomalous water quality values of 1 h duration and 10 levels of spike strength. The receiver operating characteristic (ROC) curve is proposed as an objective means of assessing and comparing water quality change‐detection algorithm results that is also able to provide the tradeoff between missed detections and false alarms on a single plot. The area under the ROC curve provides a measure of the sensitivity and specificity of each algorithm for each spike strength and location. Resulting areas under the ROC curve range from 0.46 for spike strengths of 1.0 (background) to 0.98 for strengths of 3.5 standard deviations from the mean, where an ROC curve area of 1.0 indicates perfect detection.
Lead variability testing in Seattle Public Schools
Authors: Boyd Glen R. , Pierson Gregory L. , Kirmeyer Gregory J. , English Ronald J.
Published: February 2018

A field‐testing program was conducted in Seattle (Wash.) Public Schools (SPS) to assess the variability of lead at drinking water sources (i.e., fountains) after implementation of a lead remediation program. A total of 768 samples—384 first‐draw and 384 flushed samples—were collected from 48 drinking water fountains during a two‐month period. Results showed the mean lead concentration to be 3 μg/L, which was notably less than the 21 μg/L measured before remediation in SPS. Twelve samples (1.6%) had lead concentrations > 10 μg/L, four samples (0.5%) showed lead levels > 20 μg/L, and no samples had lead concentrations > 30 μg/L. The highest lead concentrations and greatest variability occurred in samples from end‐use plumbing configurations consisting of standard brass materials (~3–8% lead), whereas relatively low lead concentrations and variability were observed for sources with low‐lead bubblers and components. This study demonstrated that the remediation program successfully and reliably lowered lead levels in SPS drinking water.
Effects of quenching methods on HAA determination in chloraminated waters
Authors: Hong Ying , Liu Suibing , Song Hocheol , Hu Jia , Ates Nuray , Karanfil Tanju
Published: February 2018

This study examined the effects of using ammonium chloride (NH4Cl), a chlorine quenching agent recommended by US Environmental Protection Agency method 552.3, on haloacetic acid (HAA) determination under different chloramination scenarios simulated in laboratory experiments. During the early reaction times for the surface water tested in this study (dissolved organic carbon of 3 mg/L), results showed that HAA concentration was overestimated up to 9 μg/L because of the use of NH4Cl. In all chloramination scenarios, positive errors decreased with increasing reaction time. Among the various quenching agents or methods tested, sodium arsenite (NaAsO2) and stoichiometric amounts of sodium sulfite (Na2SO3) were found to be appropriate for HAA determination in chloraminated samples. However, they have some limitations for use in practical applications. Immediate extraction of samples without using any quenching agent resulted in positive errors in HAA determination because of the low pH conditions (pH < 1) coupled with high temperature after the addition of sulfuric acid during HAA extraction. Adjusting sample pH to high values and using ascorbic acid for quenching chloramine were found to be unsuitable for HAA samples.
2007 Online Peer Review Report
Authors: Lacey Marcia
Published: February 2018

Last year marked the inaugural year for the new Peer Review Editorial Board and JOURNAL AWWA's online submission system. The results from the new system are impressive. In 2007, an initial decision was made on a manuscript in just under two months, and a final decision was made in just less than three months.
Quantification of uncertainty in microbial data—reporting and regulatory implications
Authors: Emelko Monica B. , Schmidt Philip J. , Roberson J. Alan
Published: February 2018

Microbial contaminants are often regulated differently than chemical contaminants. Microorganisms are enumerated by techniques that are frequently susceptible to considerable losses, resulting in highly variable recoveries. Accordingly, several treatment technique‐based regulations have evolved for microbial treatment. However, even these regulations ultimately require some reliance on microbial concentration data. Statistical approaches have been developed for the calculation of confidence intervals for microbial concentrations and removals by treatment processes, and these approaches take into account the various errors associated with microbial enumeration. The approaches were used here to demonstrate the relationship between methodological error and the practicality of concentration‐based regulations that require continuous and/or frequent monitoring, demonstrate the necessity of treatment technique‐based regulations such as the Long Term 2 Enhanced Surface Water Treatment Rule, demonstrate that methodological uncertainty is more substantially reduced by increasing organism count than by improving methodological recovery, and propose sampling targets of approximately 10 or more organisms to appreciably reduce the uncertainty associated with microbial quantification
The People Side of Asset Management
Authors: Stowe Joe
Published: February 2018

This article addresses the challenge facing water utilities of replacing the departing Baby Boomers. Appropriate training must address the specific requirements of each organization. It is imperative that the people resources of a utility be taken care of so that there is adequate staff to address the many other challenges facing the water industry. Almost every utility has a number of programs that address various aspects of traditional asset management, but not much attention is given to directly target staff issues. The article discusses four activities that help utilities become people‐oriented that include: initiative to provide self‐assessment; business planning/action planning; succession planning; and, leadership training.
Water Wise for Life Kiosk: Taking the Conservation Message to the People
Authors: Johnstone Clare
Published: February 2018

This article provides a brief overview of City West Water, located in Melbourne, Victoria, Australia. It is a Victorian state government‐owned water business, responsible for providing water, sewage, industrial waste, and recycled water services to more than 320,000 residential and business customers in Melbourne's central business district and inner and western suburbs. The article discusses how CWW has adopted innovative programs in order to influence customers to embrace water conservation initiatives. The joint water conservation plan (JWCP) for metropolitan Melbourne offers a showerhead exchange program, and the article presents details of the program and of its marketing campaign that included a water conservation kiosk located in a shopping mall called the Water Wise for Life kiosk. It allows face‐to‐face interactions with customers to promote conservation practices. Findings of a market research survey to test the kiosk concept are presented, along with the design of the kiosk and a description of real products showcased in the kiosk.
Building ICI Program Capacity in Small and Medium Utilities
Authors: Lander Paul
Published: February 2018

This article discusses a collaborative effort by a group of water providers in Northern Colorado to build capacity in order to provide more robust water conservation services to their Industrial/Commercial/Institutional (ICI) customers. This group focused their efforts on three projects that would compile an aggregate database of ICI water‐use data from across the region; analyze these data and create preliminary benchmarks of end use in four priority sectors; and, create an online tool for ICI customers and managers that combines a simple assessment with benchmark data and other resources and tools. Future goals of the ICI collaborators are to increase the number and extent of records in the database, use the online tool in training and education, and increase the number and quality of end‐use benchmarks for this sector.
Distribution Disruption
Authors: Zimmerman Gary J.
Published: February 2018

In his column, AWWA Executive Director Gary Zimmerman recounts a recent episode of airplane travel delays, missing connecting flights, and lost luggage. He uses this example to illustrate how any one of a multitude of variables has the capacity to disrupt water distribution at any given moment. He provides a brief introduction of the distribution issues presented in this month's JOURNAL.
Distribution system on‐line monitoring for detecting contamination and water quality changes
Authors: Skadsen Janice , Janke Robert , Grayman Walter , Samuels William , Tenbroek Mark , Steglitz Brian , Bahl Sumedh
Published: February 2018

Concerns about water quality and possible intentional contamination of water distribution systems are making on‐line monitoring an increasingly important priority for many water utilities. The city of Ann Arbor (Mich.) evaluated different water quality monitoring parameters, tested multiple manufacturers— monitoring equipment, and evaluated how to effectively locate monitoring equipment within the distribution system to address these two concerns. A suite of modeling tools was used in this case study. Total chlorine, ultraviolet absorbance at 254 nm, conductivity, and dissolved oxygen were selected for monitoring based on pilot testing. When balancing costs and benefits, four stations for monitoring water quality and four stations for monitoring contamination events were found to be sufficient for the city. Only one location was common between water quality and security sites, and the number of security monitors needed was not affected by system demands. It was confirmed that it is critical to minimize response time in order to mitigate the effects of a contamination event.
Keeping the Experienced Generation
Authors: Roy Justin G.
Published: February 2018

With recent talk about how to find and retain the younger generation within today's workforce, the importance of another employment‐related issue is being ignored: how will water utilities keep experienced, retirement‐aged professionals, and why should these professionals be retained? The natural cycle of employment ‐ employees leaving and employees joining an organization ‐ is something employees look forward to, whether at a junior or senior level. The retirement of a senior‐level employee has always meant greater opportunity (career growth) for the junior‐level employees of the next generation. This article discusses options that water utilities should consider when facing the issue of succession planning for the future.
Toward Sustainable Growth in Arid Climates: Requiring Developers to Show Water Supplies Are Adequate
Authors:   Brownstein Hyatt Farber Schreck
Published: February 2018

Colorado recently enacted legislation that grants power to local government agencies to deny approval of a proposed development if the developer fails to show that there are adequate water supplies to support the project. Although this type of legislation is also mirrored in California and Arizona, the standards for assessing the adequacy of a water supply vary slightly in each jurisdiction. This article considers the water supply assessment requirements for Arizona, California, and Colorado.
Planning for knowledge retention now saves valuable organization resources later
Authors: Blankenship Linda , Bruck Terry
Published: February 2018

Large numbers of drinking water utility workers are leaving the workforce, as they retire or leave to seek opportunities elsewhere. Unfortunately, a utility's most valuable knowledge is likely not written down nor is it readily learned by new workers in a written form. Utilities need a blended approach, from structured document repositories to learning and training on the organization's best practices, in order to successfully retain valuable knowledge. The article presents information from an Awwa Research Foundation research project on retaining this valuable knowledge. Utilities that successfully address the need for knowledge retention will be better‐equipped to cope with the challenges ahead ‐ increasingly sophisticated technology, stringent regulations, higher customer expectations, aging infrastructure, technology pressures, security concerns, economic constraints, and more. With all of the other initiatives, special projects, and day‐to‐day issues facing utility leaders, a program with long‐term and sometimes hidden payback like knowledge retention is a key area that utility leaders must focus on.
How not to calibrate a hydraulic network model
Authors: Hirrel Timothy D.
Published: February 2018

This article challenges the notion that hydraulic network models should be calibrated by adjusting input parameters such as roughness and demand so that model results match some set of field data. With a thorough examination of the required input and extensive manipulation of the Hazen‐Williams formula, this article shows that adjustments to input data cannot be proved correct with typically available field data and might adversely affect model accuracy, particularly if an undiscovered network anomaly exists. Discussion focuses on how network anomalies can be discovered, how a model can be used appropriately within the limitations of input accuracy, and how the extensive use of a model can improve reliability.
Sodium hypochlorite dosage for household and emergency water treatment
Authors: Lantagne Daniele S.
Published: February 2018

Point‐of‐use (POU) water treatment with sodium hypochlorite (NaOCl) has been proven to reduce diarrheal disease in developing countries. However, program implementation is complicated by unclear free chlorine residual guidelines for POU water treatment and difficulties in determining appropriate dosage recommendations. The author presents evidence supporting proposed criteria for household water treatment for free chlorine residuals of < 2.0 mg/L 1 h after NaOCl addition and > 0.2 mg/L after 24 h of storage. In testing of 106 drinking water sources from 13 countries, free chlorine residual was measured for 24 h after treatment with different NaOCl doses. For most unchlorinated water (with turbidity < 10 ntu or from an improved source), the NaOCl dose necessary to meet the proposed criteria was 1.875 mg/L. For most unimproved sources with turbidity of 10‐100 ntu, the required dose was 3.75 mg/L. POU chlorination is not recommended in waters with turbidity > 100 ntu. The article also discusses the applicability of POU water treatment with NaOCl to emergency water treatment.
Comparing nanofiltration and reverse osmosis for drinking water augmentation
Authors: Bellona Christopher , Drewes Jörg E. , Oelker Gregg , Luna John , Filteau Gerry , Amy Gary
Published: February 2018

This study investigated the use of ultra‐low‐pressure reverse osmosis (ULPRO) and nanofiltration (NF) membranes for water reuse applications where lower operating pressures and a high permeate quality are desired. A laboratory‐scale investigation was performed to compare the rejection and operational performance of RO, ULPRO, and NF membranes and to select two membranes for testing at a California water facility. A ULPRO membrane and an NF membrane were then tested at pilot and full scale at a water recycling plant and monitored for operational performance and rejection of total organic carbon, total nitrogen, and regulated and unregulated organic micropollutants. Pilot‐ and full‐scale testing of the best‐performing membranes demonstrated that both ULPRO and NF membranes could be used to meet potable water quality requirements. The presumed advantage of using ULPRO and NF membranes diminished as fouling occurred, resulting in operating pressures only slightly lower than or similar to those found for traditional RO membranes.
Naming conventions and documentation for distribution system modeling
Authors: Doe Steve R.K. , Duncan Charles T.
Published: February 2018

Water distribution system computer models are increasingly used as a critical part of designing and operating water systems. Although many water utilities have such models, their usefulness is often greatly reduced by poor naming conventions used during model development. In many cases, once a model leaves the model developer, it cannot be determined when it was last updated nor what its purpose was without extensive and costly rework. Despite the benefits of a systematic naming convention, including improving communication between developers and users, very little literature exists on model‐naming conventions, model management, and documentation. This article explores systematic naming conventions in hydraulic modeling on the basis of a review of more than 1,000 models. A framework for naming model files, scenarios, data sets, network elements, and model development process documentation is provided.
Arsenic removal at llinois iron removal plants
Authors: Holm Thomas R. , Kelly Walton R. , Wilson Steven D. , Talbott Jonathan L.
Published: February 2018

Samples of source groundwater and treated water were collected from 31 iron‐removal plants with at least one well for which the arsenic concentration was above the maximum contaminant level of 10 μg/L. In most samples, arsenite made up at least 80% of dissolved arsenic. Arsenic removal efficiencies varied widely for iron concentrations < 3 mg/L, but for iron > 3 mg/L, soluble arsenic concentrations were lowered by at least 75%. A parametric model of arsenic removal that considers the effects of other adsorbing substances fit the data fairly well. Arsenic removal appeared to be much more influenced by dissolved organic matter than by silica, carbonate, or phosphate. An electrostatic adsorption model also fit the data fairly well but not as well as the parametric model.
Are Drinking Water Regulations Affordable?
Authors: Pontius Fred
Published: February 2018

This article argues that in order to equitably address real public health issues facing communities of all sizes, affordability must be clearly understood and addressed. After seven years of experience with the current drinking water affordability criteria, the U.S. Environmental Protection Agency (USEPA) concluded in 2006 that refinements should be considered to address the situations within communities with below‐average incomes or above‐average costs (USEPA, 2006). The article discusses affordability and exemptions, affordability and variances, affordability criteria under review, and achieving sustainable water systems.
Committee Report: Disinfection Survey, Part 1—Recent changes, current practices, and water quality
Authors:   AWWA Disinfection Systems Committee
Published: February 2018

In 2007, the AWWA Disinfection Systems Committee conducted its fourth survey of drinking water disinfection practices. This first‐time online survey presented new challenges and benefits. Compared with the 1998 survey, fewer small systems (those serving populations < 10,000 people) responded and more mid‐sized to large groundwater systems responded. Ninety‐eight percent of respondents reported providing disinfected water. Chlorine gas remained the predominant disinfectant, used by 63% of respondents. Use rates for chloramine (30%), chlorine dioxide (8%), ozone (9%), and ultraviolet light (2%) increased from the prior survey. “Disinfection Contact—In Plant” (assumed for microbial inactivation) was the most frequently cited treatment. Almost half of respondents cited disinfection‐related changes since the last survey. Survey respondents appear compliant with current microbial and disinfection by‐product regulatory requirements and well positioned for compliance with future requirements.
Efficacy of disinfectant residualon microbial intrusion: A review of experiments
Authors: Besner Marie‐Claude , Servais Pierre , Prévost Michèle
Published: February 2018

In order to determine the effectiveness of a disinfectant residual in the event of accidental microbial intrusion, a literature review was conducted of numerous studies, specifically investigating the fate of microorganisms introduced into experimental systems (laboratory‐, pilot‐, and isolated full‐scale). In these experiments, various types of microorganisms (including pathogens) were monitored in the presence or absence of a disinfectant residual. Monitoring of the organisms was performed in the bulk water and/or the biofilm. This review uncovered discrepancies in the findings obtained from laboratory‐ and pilot‐scale settings regarding the persistence of microorganisms in biofilm following an intrusion occurrence. However, by extrapolating the findings of the experimental systems, the most critical conditions with respect to microorganism persistence in a water system were identified: intrusion/inoculation taking place under zero‐ or low‐flow conditions and/or delay between the time of intrusion/inoculation and the onset of disinfection.
Taps
Authors: Grumbles Benjamin H.
Published: February 2018

In this article, the author reflects on his six year career with the U.S. Environmental Protection Agency, part of which was spent as assistant administrator for water. Memorable highlights related to safe water include the following: a newly promulgated arsenic standard; strengthening the Lead and Copper Rule; regulatory controls on disinfection byproducts, Cryptosporidium and other contaminants in surface water systems; regulating microbial contaminants in groundwater systems; and, revisions to the Total Coliform Rule to strengthen safeguards against bacteria. Highlights related to secure water include the following: vulnerability assessments and emergency response plans; tools for mitigating threats of chemical and biological contamination as well as physical and cyber attacks; the Water Security Initiative; and water and wastewater response networks (WARNs). Topics related to sustainable water highlights include: the focus on four pillars of sustainable infrastructure ‐ better management, full‐cost pricing, water efficiency, and watershed management; and, the 2007‐08 Green Infrastructure Partnership. The author presents emerging challenges such as climate change, greenhouse gas emissions, and pharmaceuticals and personal care products in water.
Filtration: A Phenomenal Process
Authors: Lacey Marcia
Published: February 2018

When filtration was first used as a means of purifying water, it's doubtful that those who applied it envisioned a future when the process would be refined enough to be able to remove contaminants not visible to the naked eye. This month's articles detail the abilities of several types of filtration to do just that.
Monitoring and Testing: A Critical and Growing Sector of the Water Industry
Authors: Maxwell Steve
Published: February 2018

This article discusses how high‐quality information and increased understanding of that information are critical to sustaining natural ecosystems and maintaining public health. This improved information makes the nation's modern industrial economy and advanced manufacturing practices possible. The testing and monitoring sector of the water industry is composed of fixed‐base analytical laboratory equipment, in‐line and field water quality monitoring systems, water meters and devices to measure water quantity, data collection and transmission systems, analytical software packages, and commercial water testing and analysis firms. Taken together, the monitoring and testing business represents a critical part of the water industry; annual revenues are estimated at around $2 billion in the United States alone. The article presents recent trends and developments in this field, along with a brief overview of the critical role played by monitoring and testing at various stages in the natural hydrologic cycle and within water treatment storage and distribution systems. The article wraps up with a statement on the outlook for the water quality monitoring and testing sector of the industry.
Resilient and Sustainable Water Infrastructure
Authors: Santora Marc , Wilson Rande
Published: February 2018

This article discusses the importance of increasing the resiliency and sustainability of critical assets within the water sector. To meet this challenge, the water sector must fundamentally change the way the nation views and manages its water infrastructure. The evolution of this essential utility business model, from compliance to resiliency and sustainability, can be accomplished by focusing on the following priority areas: effective utility management; full‐cost pricing of services; efficient use of water; and, protection of resources. The article discusses in detail these four priority areas, along with interdependencies such as drinking water infrastructure providing a vital public safety function for fighting fires.
Arsenic removal using oxidative media and nanofiltration
Authors: Moore Kenneth W. , Huck Peter M. , Siverns Steve
Published: February 2018

Nanofiltration (NF) is a promising drinking water treatment technology for arsenic removal; however, most of the research on NF treatment of arsenic has used synthetic water. In this investigation, a pilot membrane system treated groundwater naturally contaminated with arsenic to test the performance of two NF membranes and one reverse osmosis (RO) membrane, both with and without oxidizing pretreatment using manganese dioxide (MnO2). The arsenic concentration in the groundwater was ~ 40 μg/L, mostly present as arsenite, a neutral species. Without the oxidizing pretreatment, the two NF membranes provided almost no removal whereas the RO membrane provided ~ 25 to 50% arsenic removal, depending on operating conditions. Following pretreatment with MnO2, the treated arsenic concentration dropped to < 4 μg/L (90% removal) for all three membranes. The substantially improved performance for these negatively charged membranes was attributed to the oxidation of the neutrally charged arsenite to negatively charged arsenate. These results indicate that where arsenite is present, facilities with RO or NF processes can dramatically enhance their arsenic removal by adding a membrane‐compatible oxidation step such as MnO2 filtration.
Evaluating surrogates for Cryptosporidium removal in point‐of‐use systems
Authors: Muhammad Nur , Sinha Rajib , Krishnan E. Radha , Piao Haishan , Patterson Craig L. , Cotruvo Joseph , Cumberland Scott L. , Nero Vincent P. , Delandra Carol
Published: February 2018

Because of their small size, Cryptosporidium oocysts cannot be easily filtered from water. This study evaluated the use of surrogates for measuring the microbial treatment performance of two point‐of‐use devices incorporating filtration with electrostatic charge interaction mechanisms. Both systems were challenged with Cryptosporidium oocysts (4‐6 μm), Bacillus subtilis (B. subtilis) spores (~1.2 μm), polystyrene latex (PSL) beads (~ 3 μm), Escherichia coli, and MS2 bacteriophage. The target biological contaminants were more effectively removed than the PSL beads, and the smaller B. subtilis spores mimicked Cryptosporidium oocyst removal more closely than the ~ 3‐μm PSL beads. Thus, surface charge appears to be an important factor for microorganism attachment, and B. subtilis spores should be considered a more appropriate surrogate than PSL beads for evaluating Cryptosporidium movement through charged media. For noncharged devices, PSL beads may still be useful as a surrogate for Cryptosporidium.
Modeling variable‐speed pump operations for target hydraulic characteristics
Authors: Wu Zheng Yi , Tryby Michael , Todini Ezio , Walski Thomas M.
Published: February 2018

Conventional hydraulic models can be used to analyze operational scenarios for a variable‐speed pump (VSP) delivering target hydraulic characteristics of either the fixed hydraulic head or the desired pump flow. However, modelers must repeatedly adjust relative speed factors for achieving the target hydraulic performance, which can be a time‐consuming task. A new solution method has been developed for directly calculating the required VSP speed to provide a fixed hydraulic head. However, this method needs to be extended as a generic modeling approach for practical applications. This article presents an enhanced VSP solution method that extends the previously developed VSP hydraulic network solver to automatically calculate the relative pump‐speed coefficient for attaining the prescribed hydraulic head or pumping the preferred amount of flow. Using this improved method, engineers can model not only a single VSP but also multiple VSPs with rule‐based logic controls. This allows the target control head to be specified at any location or for the target flow to be specified for VSPs of different capacities. The extended method provides a flexible, robust modeling approach for engineers to analyze a variety of VSP configurations in water and wastewater collection systems.
Cyclic storage systems optimization: Semidistributed parameter approach
Authors: Alimohammadi Saeed , Afshar Abbas , Mariño Miguel A.
Published: February 2018

As defined in this article, a cyclic storage system integrates a surface water subsystem with a groundwater subsystem in an interactive loop in order to satisfy demand. This article presents a semidistributed optimization model for design and operation of a proposed cyclic system. The model includes interacting components of surface and groundwater subsystems with the objective of minimizing total system costs. A generalized and modified unit‐response matrix method is developed and embedded into the optimization model. The response matrixes are developed employing the MODFLOW model. These unit responses are embedded into the optimization model forming a simulation‐optimization scheme. Application of the model shows that release from the reservoir does not necessarily follow a storage rule curve as might be expected in a noncyclic system. Solution to the proposed model, in addition to the design parameters, provides the optimal operation for the defined cyclic storage system.
From Regs to the Web, It's All About Communication
Authors: Zimmerman Gary J.
Published: February 2018

In his column, AWWA Executive Director Gary Zimmerman stresses the importance of communication, and provides examples of AWWA communicating with U.S. regulatory agencies to develop regulations that benefit and protect public health. He also urges readers to visit AWWA's Government Affairs website to stay informed about the latest developments in Washington, D.C., and mentions the downloadable videos that are regularly updated to help viewers stay current with water issues. The AWWA headquarters website has been updated, and Zimmerman discusses several of the changes including: one login, one checkout; update your own profile information; personalize your communication preferences; and, an upgraded eLearning platform.
Drinking water regulations: Estimated cumulative energy use and costs
Authors: Reiling Stephen J. , Roberrson J. Alan , Cromwell John E.
Published: February 2018

Although the cumulative energy use and costs from the 18 National Primary Drinking Water Regulations is significant, it is much less than the amount of energy typically used for pumping treated water through the distribution system. This study was undertaken to not only determine the cumulative energy use and costs from these regulations, but also to further the understanding of relationships between energy use and utility operation and maintenance costs. As advanced treatment technologies – ozone, ultraviolet light, and membranes, for example – are increasingly incorporated into new plants and plant upgrades, the energy required for these advanced technologies must also be incorporated into their lifecycle evaluation. The information presented in this article will help water utility managers gain a better understanding of how these energy‐intensive advanced treatment technologies will increase operations and maintenance costs in perpetuity. In addition, utility operators will better understand the continual need to optimize their energy use.
Demonstrating 4‐log adenovirus inactivation in a medium‐pressure UV disinfection reactor
Authors: Linden Karl G. , Shin Gwy‐Am , Lee Jung‐Keun , Scheible Karl , Shen Chengyue , Posy Phyllis
Published: February 2018

Previous bench‐scale results demonstrated that polychromatic medium‐pressure (MP) ultraviolet (UV) disinfection could achieve 4‐log adenovirus inactivation at equivalent UV doses well below those required under the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). These findings were confirmed and extended to a full‐scale UV disinfection reactor using a live adenovirus challenge. The MP UV disinfection system was able to measure > 4‐log adenovirus disinfection at an MS2 coliphage reduction equivalent dose (RED) of < 100 mJ/cm2. The highest observed adenovirus‐based RED achieved, referenced to a low‐pressure (LP) UV dose‐response, was 233 mJ/cm2; the validated RED, including relevant validation factors, was equivalent to that required by the LT2ESWTR for 4‐log virus inactivation credit. These results proved that required virus disinfection doses can be validated and that MP UV is capable of meeting the 4‐log virus disinfection standard in the LT2ESWTR at a measurable and achievable UV dose substantially lower than that of LP UV technology.
Head Loss Solutions Increase Flow From Thornydale Booster Station
Authors: Denman Dan
Published: February 2018

This field report discusses an effort by Tucson Water to deliver water to five golf courses in Tucson. Problems were encountered with head loss from vertical turbine pumps at the Thornydale Booster Station, and also with the omission of air‐release valves (ARVs) from reclaimed water main “drop” sections. A third issue was discovered with the lateral 16‐in. main that connects a storage tank to pumps, and when full, this control tank turns boosters off. By carefully researching all aspects of the booster delivery system and its mains, the problems were identified, and the solutions slowly improved this system. For example, by calculating net‐positive suction head available, conducting surge‐pressure analysis, calculating anticipated head losses, and tracking down odd pressure readings at selected main locations, Tucson Water was able to narrow the field and pinpoint trouble. During pump tests, volts, amps, and flow were recorded, thus eliminating pump problems.
Guarding Against the Insider Threat
Authors: Archuleta Edmund G. , Moyer Jack
Published: February 2018

This article discusses a study done by the National Infrastructure Advisory Council (NIAC) to explore the problem of insider threat to the security of water systems. The NIAC report describes the insider threat as the potential for an employee to use his or her position of trust to cause significant disruption to critical infrastructure services. This potential is a combination of two key elements: access and inside knowledge. The article presents information on common elements and psychology of perpetrators of insider attacks, and provides steps to safeguard against an insider threat.
Water resources technologies for sustainable water planning
Authors: Frias Rafael E. , Binney Peter
Published: February 2018

Utility managers are charged with providing safe and reliable water services to current and future customers. Sustainability has emerged as an influential utility strategy that guides the organization's planning and development of approaches to serving their customers’ day‐to‐day and long‐term needs. These sustainability strategies improve resource efficiency, direct long‐term investment strategies, and reduce implementation risks. The article describes a wide range of technologies and programs that can be considered when adapting a portfolio of strategies to include the most cost‐effective and easily implemented approaches for delivering safe and reliable services to water utility customers. By considering the full water cycle and the capability of emerging technologies to cost‐effectively treat marginal‐quality water sources, the water manager is more likely to successfully navigate the public and political interactions that are an integral part of successful utility planning and ensure more reliable sources of water now, and in the future.
Fluidized bed bioreactor treatment of perchlorate–laden groundwater to potable standards
Authors: Webster Todd S. , Guarini William J. , Wong Hang Sau
Published: February 2018

During the past decade, perchlorate at levels above regulatory standards has become increasingly prevalent in drinking water aquifers. A large pilot‐scale biological fluidized bed reactor (FBR) followed by a surface water treatment plant was tested to demonstrate effective treatment of perchlorate‐laden groundwater to potable water. At perchlorate concentrations up to 1,000 μg/L, nitrate‐nitrogen concentrations of 6.1 mg/L, and flow rates of 95‐189 L/min (25‐50 gpm), the FBR treatment plant was effective in removing perchlorate and producing potable water that met all drinking water regulations before disinfection. The use of on‐line perchlorate and nitrate analyzers allowed for rapid analysis of plant performance and provided continuous electron donor feed control to maintain optimal contaminant treatment rates. Recovery from feed and plant electrical interruptions was rapid in achieving acceptable treatment performance. Study results provided essential design data for a potential full‐scale treatment plant.
Generations at Work: The Problems, Power, and Promise Explored
Authors: Wilson Linda
Published: February 2018

This article discusses inter‐generational relationships within the workplace, and provides lists of work group traits for each generation (Traditionalists, Baby Boomers, Gen Xers, and Millennials), and what each group values and needs to flourish on the job. The article focuses on the diversity and techno‐knowledge of the Millennials, and suggests several activities that organizations and their workers can do to better understand each generation.
Metering residential irrigation water: Technological approaches and cost estimations
Authors: Richards Gregory L. , Johnson Michael C. , Barfuss Steven L.
Published: February 2018

An increasing number of secondary or dual water systems, which typically deliver irrigation water, are taking steps to meter all residential connections. Although metering encourages conservation and provides increased manageability, metered systems also face unique challenges principally related to water quality. In order to use standard meters, filtration must be used to clean secondary water to a level sufficient for meters to perform well. Increased operational expenses attributable to water treatment, meters, meter reading, and maintenance interfere with inexpensive water pricing methods generally used in secondary systems. Consequently, the question of metering ultimately hinges on economic feasibility for the majority of secondary water providers. This article outlines the technologies currently available for secondary water metering applications. Approximate costs and design requirements of these technologies are identified, thereby allowing water suppliers to determine the economic feasibility of metering. In addition, other design precautions and considerations for implementing secondary metering are discussed.
Desal Plant Delivers
Authors: Hoehn Kai‐Uwe
Published: February 2018

This article discusses a cost‐effective, state‐of‐the‐art, energy‐efficient reverse osmosis (RO) seawater desalination plant located in Perth, Australia. The Perth plant became fully operational in April 2007 and now produces 144,000 m3/d of water. Located in the industrial area of Kwinana, 40 km south of Perth, the project is the result of a successful collaboration between Western Australia Water Corporation (WAWC) and proAlliance, a joint venture of Degremont and Multiplex, that built the plant after Degremont won the contract in 2005. A subsidiary, Degremont Australia Pty. Limited, was chosen in an alliance with WAWC to operate the plant on a 25‐year contract. For the RO process, Degremont selected FILMTEC? membrane elements from Dow Water Solutions to compose the two‐pass RO system for seawater and brackish water.