bluuebunny/crossref_metadata_2025 huggingface dataset:
MIEX for removal of DBP precursors: Pilot‐plant findings
Authors: Singer Philip C. , Schneider Maria , Edwards‐Brandt Jessica , Budd George C.
Published: February 2018

A 10‐gpm pilot plant was operated for four to five weeks at each of four US water treatment plants to evaluate the effectiveness of a magnetic ion exchange (MIEX) process for the removal of disinfection by‐product precursors. Variables examined were resin concentration, contact time, and regeneration frequency. Influent and effluent samples were taken on a regular basis and analyzed for ultraviolet (UV) absorbance at 254 nm, dissolved organic carbon (DOC), and bromide. Samples of the raw water and the MIEX‐treated water were also subjected to hydrophobic/hydrophilic fractionation, molecular size characterization, and chlorination under uniform formation conditions to determine the trihalomethane (THM) and haloacetic acid (HAA) formation potential before and after MIEX treatment. Results indicated that the resin removed substantial amounts of DOC and UV‐absorbing materials, except in one of the waters that had a high concentration of total dissolved solids and a low specific UV absorbance. The MIEX resin also removed bromide to some degree, depending on the presence of other competing anions in the raw water. Overall THM and HAA formation was decreased substantially as a result of MIEX treatment.
Becoming a Woman Entrepreneur in the Water Services Industry
Authors: Darr‐Bornstein Kristin , Miller Marsha
Published: February 2018

This article summarizes the experiences of two women who, after working together for many years in the engineering and environmental consulting industry, started a small business of their own in the water industry. The article discusses their transition from the security of working for an established firm to managing a small startup company, becoming certified as a woman‐owned business, the educational background necessary to start a business, the risks involved in starting a business, and lists the highlights of working at KDA during the past five and a half years. The article provides recommendations for starting your own business.
Policy Objectives in Designing WATER RATES
Authors: Gaur Sanjay
Published: February 2018

There are four identified policy criteria that water agencies may consider when designing their water rate structures. A rate structure should be financially sustainable, socially equitable, environmentally sound, and administratively manageable. However, there is no universal rate structure that meets all of the objectives of these criteria because the objectives tend to conflict with each other. In addition to considering these policy criteria, a water agency should also identify the following four key components when developing a rate structure: the revenue requirement; the classification of system cost; the allocation to customer classes; and, the design of the rate structure. Each water agency must prioritize these policy criteria and characteristics to determine the “correct” water rate structure for its specific community. Understanding your community's makeup and priorities, as well as the needs of the water utility, and clearly defining and documenting your rate structure process are the key to a positive result.
Reducing energy consumption for seawater desalination
Authors: Veerapaneni Srinivas (Vasu) , Long Bruce , Freeman Scott , Bond Rick
Published: February 2018

As freshwater sources become increasingly stressed, many coastal communities are looking to seawater desalination to augment their supplies and meet growing demand. Seawater desalination is an energy‐intensive process, however, with energy expenses accounting for a significant part of the process operating cost. This article looks at the factors affecting energy consumption for seawater desalination and discusses design and technological developments that can improve efficiency. Although the salinity of the feedwater affects the energy consumed during desalination, energy consumption is also influenced by such factors as recovery, flux, membrane type, ancillary processes, type of equipment, and energy‐recovery devices. To improve efficiency, utilities must take into account design and operation of all these components. Recent advances in desalination technology are making the process more energy‐efficient and cost‐effective. Water providers can do their part by optimizing system design to foster energy efficiency so that, ultimately, more communities can economically tap into untapped sources of supply.
DOM in Recharge Waters of the Santa Ana River Basin
Authors: Leenheer Jerry A. , Aiken George R. , Woodside Greg , O'connor‐Patel Katherine
Published: February 2018

Assessment of the composition, reactivity, and potential health effects of dissolved organic matter (DOM) is an important issue in the regulation and operation of groundwater recharge projects. The composition of DOM in various natural surface waters and reclaimed waters used to recharge the alluvial aquifers of the lower Santa Ana River Basin in California was derived primarily from terpenoid hydrocarbons and amino sugars. Lesser amounts of aromatic sulfonate and alkylphenol polyethoxylate metabolites of anionic and neutral surfactants were detected in reclaimed water, and these metabolites persisted in waters of the Santa Ana River, the Prado Wetland, and the recharge basins. Only small amounts of humic substances derived from tannins and lignins were deposited during storm flow periods in the Prado Wetland, but these amounts were responsible for significant increases in disinfection by‐product formation potential in these waters. Colloids composed of bacterial cell wall fragments showed large percentage increases in all waters during storm flow periods.
Capital Prioritization in a Large City
Authors: Gilmore William B.
Published: February 2018

This report presents an asset prioritization methodology implemented by the New York City Department of Environmental Protection (NYCDEP) when it began planning for an upgrade of its aging water and sewer infrastructure assets. The report discusses the step‐by‐step risk mitigation program.
Occurrence and co‐occurrence of perchlorate and nitrate in California drinking water sources
Authors: Kimbrough David Eugene , Parekh Pankaj
Published: February 2018

Perchlorate, a chemical that affects the ability of the thyroid to absorb iodide, has been detected in many drinking water sources, mainly groundwaters. Perchlorate enters groundwater via permeation from surface water; other contaminants can enter groundwater in the same fashion. The purpose of this study was to determine the overall distribution of perchlorate and nitrate in California drinking water sources and the co‐occurrence (if any) of nitrate and perchlorate. The study used the California Department of Health Services Division of Drinking Water and Environmental Monitoring database of all source water monitoring results, including those for nitrate and perchlorate. Data for nitrate (1994–2003) and perchlorate (1997–2003) were queried, and results (including nondetects) were averaged. A similar query was performed for all results above the reporting limit. All sources with positive results for perchlorate were queried for nitrate results. Nitrate results collected within 180 days of a positive perchlorate result were used. Results indicated that the mean perchlorate level in California drinking water sources was 3.6 μg/L, and the mean nitrate level was 21,000 μg/L. Among sources with positive perchlorate results, the mean perchlorate result was 12 μg/L, and the mean nitrate result was 39,000 μg/L for nitrate. A weak but statistically significant correlation was found between the concentrations of perchlorate and nitrate (R2 = 0.31, p < 0.001).
Information Disclosure and Security Information Protection at Water Utilities
Authors: Herrick Charles , Blaha Frank J.
Published: February 2018

This article discusses information disclosure and security information protection at water utilities. It focuses on security‐oriented vulnerability assessments (VAs) that may be used by terrorists as a roadmap of key system components/processes if reported to the U.S. Environmental Protection Agency as required by the Bioterrorism Preparedness and Response Act of 2002. Because of this concern, the Bioterrorism Act exempted VAs from Freedom of Information Act (FOIA) release. Contradicting this, most water utilities were already subject to state “sunshine laws” that required disclosure of most information requested by any member of the public. Consequently, the article discusses how water utilities face a difficult and ongoing challenge of identifying and managing the release of potentially sensitive information.
Using customer feedback for improved water quality and infrastructure monitoring
Authors: Whelton Andrew J. , Dietrich Andrea M. , Gallagher Daniel L. , Roberson J. Alan
Published: February 2018

This research found that capture and analysis of customer feedback about water quality, quantity, aesthetics, illness, and security can be an effective early warning system for monitoring water quality, process control, and infrastructure access. Interviews with utility workers and a review of published literature revealed that customers reported more than 82 incidents related to water treatment process failures, system intrusions, and accidental and intentional contamination. However, not every utility has established a comprehensive process for collecting, organizing, storing, tracking, and reviewing customer feedback. The lack of standardized terminology and effective data management limits the potential of customer feedback as a tool for monitoring water quality and alerting the utility to infrastructure concerns. Because they are located throughout the distribution system and are “on call” 24/7, customers can provide an early warning of potential problems. By improving the processes for handling customer complaints and concerns, utilities will gain not only a better understanding of water quality but a valuable resource for safeguarding supplies.
Assessing the effect of distribution system O&M on water quality
Authors: Besner Marie‐Claude , Gauthier Vincent , Trépanier Martin , Martel Kathy , Prévost Michèle
Published: February 2018

Historical water quality variations were evaluated in several distribution systems using a data integration approach. Utilities from three Canadian cities, two European cities, and two US cities participated in the study. The approach discussed here combines the use of water quality, system operations and maintenance (O&M) data, a hydraulic model, and a geographical information system. Temporal, spatial, and hydraulic proximities among occurrences were achieved through database queries. This investigation included: 140 coliform‐positive samples in five distribution systems; 48 occurrences of heterotrophic plate count (HPC) bacteria in four systems; and 217 customer complaints from three systems. The objective of this research was to identify the main causes of water quality variations to eventually determine the proportion attributable to O&M activities. The results showed that the role of O&M activities in the occurrence of coliforms in distribution systems varies, explaining 9–45% of coliform cases investigated in each system. O&M work was associated with about 30% of customer complaints investigated in each of the networks studied, and its association with HPC events was negligible in three out of four systems. Although O&M activities benefit water quality in the long term, greater understanding of their short‐term negative effects could better prevent and control potential water quality degradation.
people
Authors: Miner Gary
Published: February 2018

This article announces that Andrew W. Richardson, AWWA's 2005‐06 president, has been named chief executive officer of Greeley and Hansen, an engineering and consulting firm headquartered in Chicago, Illinois, that specializes in water, wastewater, and solid waste projects. In his new position, Richardson will work with the firm's principals and executive management team to lead the firm forward in its strategic vision of long‐term growth.
E. coli as a public health indicator of drinking water quality
Authors: Standridge Jon
Published: February 2018

Public health practitioners and water providers have been testing water for microbial contaminants for more than a century. In the United States, public water testing is regulated by federal law. The specifics of the federal law are enforced through such rules as the Total Coliform Rule (TCR). A negotiated rule‐making process to amend the TCR is under way. As this process proceeds, it is important that stakeholders have access to the latest information pertinent to the discussion. This article provides information to be used in evaluating Escherichia coli for inclusion in the amended rule as a potential indicator for drinking water monitoring. Advances in the techniques used for coliform and E. coli testing, new understanding about distribution system biofilms, newly emerged waterborne pathogens, and international changes in the use of E. coli as an indicator all combine to underscore the importance of reconsidering the role of E. coli as an indicator organism.
Lead release from new end‐use plumbing components in Seattle Public Schools
Authors: Boyd Glen R. , Pierson Gregory L. , Kirmeyer Gregory J. , Britton Michael D. , English Ronald J.
Published: February 2018

Field and laboratory studies were conducted to determine lead release from new end‐use plumbing components installed at drinking water sources (primarily fountains) in Seattle (Wash.) Public Schools. Small‐volume sequential field sampling results indicated that most of the lead originated in the first 50 mL drawn from the source. Laboratory testing of new end‐use plumbing components showed elevated lead concentrations during early exposure. Periodic spikes in lead were attributed to the movement of valves and possible release of metal particulates or dezincification of brass materials. New end‐use plumbing components typically had been installed immediately after purchase. Study results helped identify likely sources of lead and develop mitigation measures (such as preconditioning) so that drinking water sources can be used immediately after retrofitting and meet the Seattle school board policy limiting lead concentrations to 10 μg/L.
Invisible Support
Authors: Zimmerman Gary J.
Published: February 2018

In his column, AWWA Executive Director Gary Zimmerman relates the story of his Grandfather Morris, and compares Morris’ low‐key, gentle influence on his family to that of this month's focus topic, infrastructure, and how it quietly and without fanfare supports and affects many lives in countless ways. He goes on to introduce specific aspects of the Journal's focus topic that are covered in this issue, including: leak detection; pipe evaluations; asset management; advanced metering infrastructure; and, new ways to repair and rehabilitate pipe.
Asset Management in the Age of GIS: Two Approaches to Managing Water Pipeline Infrastructure
Authors: Hanson Paul H.
Published: February 2018

This article discusses two approaches to managing water pipeline infrastructure. The Greater Cincinnati Water Works (GCWW) asset management program is aimed at managing the city's infrastructure as cost‐efficiently as possible. The GCWW asset management plan includes: monitoring the performance of assets to ensure they are operating effectively and at the least possible cost; coordinating the utility's planning and operations with the long‐term planning of the community, e.g., street repairs and new developments; and, uploading information into its computers on soil data, exact pipeline locations, information from reports of inspections, leaks, and breaks, types of breaks, and the direction the pipe was laid. The article also highlights the Akron, Ohio, Public Utilities Bureau's experience with developing an asset management program. Both utilities’ experience using a Geographic Information Systems‐based asset management plan is presented.
Water Sector Benchmarking and Environmental Sustainability
Authors: Gritsinin ALexander ,   The Nature Conservancy
Published: February 2018

This article discusses benchmarking in the water sector and the development of environmentally‐based performance standards, despite the focus on the operational, financial, and regulatory compliance performance of utilities. The article discusses the growing interest among water sector practitioners, together with rich, historic data that are generating a need for a comprehensive and systematic sector‐wide evaluation of the success of benchmarking initiatives. However, no internationally recognized program currently exists that adequately appraises and rewards water utilities that are excelling in protecting watersheds, maintaining adequate water flows to sustain river ecosystems (also called environmental flows), conserving water resources, and systematically implementing integrated water resource management. The article goes on to mention that, by designing and implementing its Blue Water Awards initiative (Richter, 2007), The Nature Conservancy is attempting to help utilities respond to these pressures by translating freshwater biodiversity and watershed protection and conservation goals into operational and economic objectives.
Agencies Boost Enforcement of Construction Site Stormwater Rules
Authors: Pontius Fred
Published: February 2018

This article discusses how regulatory agencies at the state and national levels have increased Clean Water Act (CWA) enforcement activity against developers who fail to meet storm water permitting requirements at construction sites. The article describes how sediment runoff from construction sites is far greater than from agricultural and forest lands, and therefore, how construction activity contributes more sediment to streams than other sources. Further topics covered in the article include: Clean Water Act regulation of storm water; establishing a pattern of violations; and, continued scrutiny and active enforcement activity by the U.S. Environmental Protection Agency and state regulatory agencies, including inspections, information requests, and possible initiation of administrative or judicial enforcement cases.
Sensor Response to Contamination in Chloraminated Drinking Water
Authors: Szabo Jeffrey G. , Hall John S. , Meiners Greg
Published: February 2018

This article discusses the response of commercially available water quality sensors to contamination in a model drinking water system using chloramines as a residual disinfectant and how the results could impact decision‐making regarding development of a contaminant warning system. The experimental design of the study is presented, along with the response of standard water quality parameters and a comparison of free and total chlorine responses in chlorinated and chloraminated systems. Implications for contaminant warning systems are discussed.
Portable pressure wave‐maker for leak detection and pipe system characterization
Authors: Brunone Bruno , Ferrante Marco , Meniconi Silvia
Published: February 2018

This article illustrates the performance of the portable pressure wave maker (PPWM; patent pending) device for leak detection and pipe characterization used in the water engineering laboratory of the University of Perugia, Italy. The device consists of a steel vessel filled with pressurized air and water that is connected to a test pipe by a short conduit with a connection valve at its end. By a pressure value being fixed in the PPWM that is higher than the pressure in the pipe, a pressure wave propagates in the line when the connection valve is opened. Singularities (e.g., junctions, partial blockages, and leaks) will give rise to the formation of reflected waves whose arrival time and amplitude—recorded in one or more sections of the pipe—allow their detection. Because of its modest dimensions, the PPWM can easily be carried to plants and facilities as part of a transient test‐based leak‐detection and system‐characterization campaign. First, experimental evidence of PPWM device behavior for pipe characterization is shown. Then optimal operational conditions are determined by means of a numerical model and are tested in the laboratory. Finally, a simple formula for evaluating the generated pressure wave is given.
Plant conversion experience: ozone BAC process installation and disinfectant residual control
Authors: Marda Saurabh , Kim Doo‐Il , Kim Myung‐Jong , Gordy John , Pierpont Skip , Gianatasio Jim , Amirtharajah Appiah , Kim Jae‐Hong
Published: February 2018

The David L. Tippin Water Treatment Facility in Tampa, Fla., treats Hillsborough River water, which has relatively high organic matter content, especially during high‐rainfall seasons. In 2001, ozonation and biologically activated carbon (BAC) filtration were implemented along with a few additional modifications to the existing conventional process. After the start of the new process, unexpectedly low monochloramine formation efficiency and rapid decay of monochloramine residual in treated waters were observed. By changing the sequence of free chlorine and ammonia injection and by providing sufficient mixing and reaction time for free chlorine, monochloramine formation efficiency was dramatically increased. Among several factors that might affect monochloramine decay rate, the particulate matter produced from the BAC filters, presumably because of microbial activities, was found to be primarily responsible for the monochloramine demand. The filter backwashing practice was modified to successfully enhance filter performance and stabilize monochloramine in treated waters.
Iron oxide–coated fibrous sorbents for arsenic removal
Authors: Kumar Arun , Gurian Patrick L. , Bucciarelli‐Tieger Robin H. , Mitchell‐Blackwood Jade
Published: February 2018

Iron oxide‐coated sand has been demonstrated to be an effective adsorbent material for the removal of arsenic and other metals and metalloids from drinking water and wastewater. In this study, fibrous materials were evaluated for their ability to offer a high specific surface area alternative to sand as the substrate for the iron oxide coating. Four types of fibrous materials, polypropylene, polyester, fiberglass, and cellulose, were evaluated for their ability to retain iron coatings and to remove arsenate. Sand was also evaluated to provide a basis for comparison with previous research. In isotherm experiments, all four fibrous materials showed higher arsenate adsorption densities than iron oxide‐coated sand. Arsenate adsorption densities were highest for iron oxide‐coated fiberglass and cellulose, suggesting that these fibrous materials may offer advantages over iron oxide‐coated sand.
Station Efficiency Reduces Greenhouse Gas Emissions
Authors: Eckard Robert
Published: February 2018

This article begins by providing a brief overview of global warming, greenhouse gas (GHG) emissions, and government‐initiated analyses and legislation that supports or requires reductions in GHG emissions and increases in energy efficiency. The focus of the article is on how emissions reductions affects the wastewater industry. Sources of GHG emissions in the wastewater industry are explored, along with reasons for losses in pump efficiency, solutions to increase pump efficiency and reduce electricity use and GHG emissions, and advances in flow and efficiency monitoring technology. Sidebars are provided on topics that include: Common Causes of Centrifugal Pump Efficiency Loss; and, State and Regional Entities Taking Steps to Reduce and Regulate Greenhouse Gas Emissions.
Climate change: Charting a water course in an uncertain future
Authors: Wallis Michael J. , Ambrose Michael R. , Chan Clifford C.
Published: February 2018

The planet is warming, and many scientists agree that the rise in temperature is human‐made. However, science has not developed a model to predict the effects of increasing temperatures. Still, water utilities can and must plan for the uncertainties of climate change and its effects on water supplies and operations. The findings of a comprehensive case study, conducted by the East Bay Municipal Utility District in California on strategies to mitigate and adapt to climate changes, are presented in this article. Water utilities must include climate change in water supply availability and resource planning and can use this case study as a framework. The information presented in this article is applicable to long‐term water supply planning and can assist with decision‐making.
Assessing the carbon footprint of water production
Authors: Strutt Justin , Wilson Sian , Shorney‐Darby Holly , Shaw Andrew , Byers Andrew
Published: February 2018

A carbon footprint (CF) analysis is the sum of the estimated carbon dioxide and other greenhouse gas (GHG) emissions associated with a particular activity or industry. Without a standardized protocol for developing a CF of water production, U.S. utilities must draw on the experiences of other nations and adapt approaches used in other industries. In the United Kingdom, mandatory regulation of emissions for large industry has spurred collaborative development of CF methods for the water industry. British and Australian utilities are conducting CF analyses and using this information to better understand the environmental impact of their water production. First, various utility activities are defined, information about power and potential GHG emissions is gathered, and the GHGs are converted to carbon dioxide equivalents to create a CF assessment. The utility can then use this baseline CF as a management tool to guide decisions about sustainable operations and construction projects as well as future resources and treatment and transmission facilities.
California Implements Water Security and Emergency Preparedness, Response, and Recovery Initiatives
Authors: Crisologo Joseph
Published: February 2018

This article discusses various initiatives and activities implemented by the California Department of Public Health (CDPH) to help water systems prepare for potential threats and disasters, ranging from terrorism to natural events such as earthquakes, pandemic influenza, brush fires, and drought. Topics covered include: Crisis and Emergency Risk Communication; Emergency Water Quality Sampling Kit; Tabletop Exercise Design Class; Golden Guardian Statewide Exercise; California Health Alert Network; and, California Mutual Aid Laboratory Network.
Water quality considerations for distribution system storage facilities
Authors: Edwards Jerry , Maher James
Published: February 2018

Many factors influence decisions about water distribution storage facilities, including cost‐effectiveness, terrain, and aesthetics. Water age analysis using sophisticated hydraulic models has identified a consideration that is often overlooked, the storage site. Locating ground‐level storage or standpipes on high ground outside the demand area can have a detrimental effect on water quality. In this research, a detailed hydraulic model and extended period simulation were used to analyze four cases with varying parameters, including water level fluctuation and storage facility type and location. A comparison of a standpipe outside the demand area and an elevated tank within the demand area found that the latter reduced water age from 17 to 6 days. A least‐cost solution using ground storage or standpipes may have been sufficient in the past, but utility managers today should also weigh such factors as location when planning new storage facilities. Inadequate turnover because of a poor storage location may add up to significant additional costs in the future.
Asset management: Quantifying economic lifetime of large‐diameter pipelines
Authors: Davis Paul , Marlow David
Published: February 2018

Large‐diameter water mains have relatively low failure rates, but significant costs can result when failures do occur. Although economic analyses to schedule water main replacements are available, they rely on historical failure data. In many cases, however, large‐diameter mains do not have sufficient failure data to enable confident application of these methods. As an alternative, water authorities can inspect pipes to determine structural condition and assess the need for and timing of future inspections and replacement. Because asset failure depends on a range of factors, however, inspection data alone cannot fully support this type of decision‐making. This article describes a methodology that combines asset condition with a physical probabilistic failure model to determine the lifetime of a large‐diameter cast‐iron pipeline. Net present value calculations are used to determine the timing of future inspections and replacement of the entire pipeline. The authors also present a case study that illustrates the use of the proposed methodology.
Averting a Water Supply Crisis While Protecting Endangered Species: Partnerships Pay Off for Tennessee's Duck River
Authors: Palmer Sally Rollins ,   The Nature Conservancy
Published: February 2018

In 1999, the Tennessee chapter of The Nature Conservancy launched one of its first river projects on the Duck River in Middle Tennessee. The Duck River program quickly became involved with many federal, state, and local partners who were beginning to tackle the water supply challenges facing several communities in the river's watershed. One of the Nature Conservancy's key partners, and the local force behind water resource planning in the watershed, is the Duck River Agency (DRA). From 2000 to 2002, DRA members worked to build trust between all partners within the watershed, improving tools for water management planning and coordinating research priorities and efforts. This article discusses how those first steps at building trust and partnerships within the watershed would pay off very soon. When Tennessee's exceptional drought came along in 2007, it put the relatively new collaboration straight to the test.
Tabletop Exercises Drive Home the Importance of Drought Planning
Authors: Mason Deirdre , Verner Duane
Published: February 2018

Areas throughout the southeast and other parts of the United States faced drought conditions of increasingly catastrophic proportions during late 2007 and early 2008, and North Carolina was no exception. Traditional conservation measures and restrictions to outdoor water uses were no longer sufficient to adequately reduce demands on water systems. To facilitate interagency dialog on ways to address the drought, the North Carolina Department of Environment and Natural Resources Division of Water Resources and the Department of Crime Control and Public Safety Emergency Management Division hosted a drought tabletop exercise. Water utilities used the tabletop exercise as well as a draft drought‐response toolbox to help them decide on response actions for worsening drought conditions. The tabletop exercises described in this article can be used by state water agencies anywhere in the United States to prepare for a drought. States and water systems can create and conduct drought exercises like the ones described here, add drought factors and actions to their emergency response plans, and work with other state and local agencies to include drought scenarios in other types of security and emergency response training exercises.
Using nitrification potential curves to evaluate full‐scale drinking water distribution systems
Authors: Fleming Kala K. , Harrington Gregory W. , Noguera Daniel R.
Published: February 2018

Nitrification potential curves were recently introduced as a practical way of determining whether water quality conditions are conducive to the establishment of nitrification in chloraminated drinking water distribution systems. The innovative concept links the total chlorine and free ammonia concentrations found in chloraminated distribution systems to the growth and inactivation kinetics of the ammonia‐oxidizing bacteria responsible for nitrification. In this study, nitrification potential curves were developed for three full‐scale, chloraminated distribution systems. The curves were then used to evaluate the nitrification control strategies in effect at each system and show how operational changes such as reducing water age or increasing pH could affect nitrification potential.
Sensor network design of contammination warning systems: A decision framework
Authors: Murray Regan , Janke Robert , Hart William E. , Berry Jonathan W. , Taxon Tom , Uber James
Published: February 2018

Contamination warning systems have been proposed as a promising approach for detecting contaminants in drinking water systems early enough to allow for the effective reduction of public health or economic consequences. A variety of modeling and optimization tools has been developed to support the design of utility‐specific contamination warning systems. However, warning system design is not a straightforward application of a software tool; it requires a series of significant decisions about the warning system—s intended nature, purpose, and use. In this article, the authors describe a decision framework that uses the threat ensemble vulnerability assessment and sensor placement optimization tool (TEVA‐SPOT) to determine sensor placement. The framework allows for the development of multiple sensor network designs that can be compared and evaluated against a standard set of criteria. TEVA‐SPOT and the decision framework have been applied to several large water systems; one of those utility examples is included here.
Microfiltration and ultrafiltration membranes for drinking water
Authors:   The Awwa Subcommittee on Periodical Publications of the Membrane Process Committee
Published: February 2018

The use of microfiltration (MF) and ultrafiltration (UF) in water treatment applications continues to expand, both in terms of capacity and number of installations. The upper benchmark for the size of membrane facilities is expected to continue to get larger. In addition, the recent Long Term 2 Enhanced Surface Water Treatment Rule and its associated Membrane Filtration Guidance Manual, representing the first federal regulatory framework that directly addresses membrane filtration, is anticipated to result in increasing standardization of diverse state primacy agency policies for regulating MF/UF. In light of these advances, a comprehensive MF/UF resource for the water treatment industry had become imperative. In 2005, the first edition of AWWA Manual of Water Supply Practices M53, Microfiltration and Ultrafiltration Membranes for Drinking Water, was published. This article provides a concise and abbreviated summary of M53 to serve as a quick point of reference.
Secondary effects of implementing arsenic removal treatment—focus on corrosion and microbial regrowth
Authors: Edwards Marc , Parks Jeffrey L.
Published: February 2018

Strong‐base anion exchange, activated alumina, and granular ferric hydroxide/oxide media are technologies that small utilities will be using for arsenic removal to meet the new standards imposed by the US Environmental Protection Agency Arsenic Rule. Under at least some circumstances, however, these treatments can be predicted to cause severe adverse consequences. The removal of natural organic matter by column treatments can lead to an increase in copper pitting. Lower levels of bicarbonate in conjunction with higher concentrations of chloride can increase iron corrosion and cause red water complaints. Higher chloride‐to‐sulfate mass ratios can increase lead release from brass fittings and solder. Conversely, column treatments may remove phosphate or other trace inorganics creating nutrient limitations, which could reduce the potential for microbial regrowth in the distribution system.
Water system preparedness and best practices for pandemic influenza
Authors: Van Atta Philip , Newsad Robert
Published: February 2018

According to public health experts and the medical community, an influenza pandemic could occur at any time. The authors conducted a literature review, interviews, and a survey of Ohio water systems to assess how prepared U.S. water systems were for a pandemic flu outbreak and found varying preparedness levels. In addition, the project determined the planning resources available for water systems and developed a template plan that systems could use for pandemic preparedness and response. In addition to triggering supply disruptions for power, chemicals, and equipment, a pandemic flu could result in serious staffing problems for water systems, with illness and family care issues creating staffing shortages up to 40%. Cross‐training for essential positions, sequestering critical employees, and implementing vaccination and other personal protection measures would be essential to maintaining adequate levels of staffing during a pandemic. The article also discusses best practices and other strategies to improve utility contingency planning.
Comparative study of three types of controllers for water distribution networks
Authors: Kumar M. Prasanna , Kumar M.S. Mohan
Published: February 2018

Proportional derivative (PD) and proportional integral derivative (PID) controllers are discussed in terms of use in water distribution networks and compared with a dynamic inversion (DI)‐ based robust nonlinear controller. Controller performance is evaluated for sequential supply to multiple reservoirs for level control and for flow control of two water distribution networks to address the issues of equitable distribution among the reservoirs. This study illustrates the novel application of control algorithms and shows that slow transients can be controlled. The DI‐based nonlinear controller outperformed other controllers. Targets such as reservoir levels and flows into a reservoir were achieved in a monotonic fashion using a PID controller. However, the targets were achieved quickly without creating undue transients with the use of a DI controller. Unlike PID and DI controllers, severe oscillations were observed with the PD controller, and the target values were not reached. In general, nonlinear control systems can be quite useful in water distribution networks.
Total water management strategies for utility master planning
Authors: Jeffcoat Stuart , Baughman Douglas , Thomas P. Michael
Published: February 2018

Increasing demands on water resources and the associated stresses of continued population growth, land‐use changes, and climate uncertainty require water managers to use more innovative approaches to long‐term water management planning. A total water management (TWM) approach integrates management of the watershed, water supply sources, land‐use practices, and related resources to provide sustainable supplies while considering equitable economic and social considerations and promoting a healthy ecosystem. The authors describe a TWM plan implemented by the Clayton County Water Authority in Atlanta, Georgia, and examine how this approach has been used successfully to meet long‐term water supply and wastewater management needs, even during excessive drought conditions. This article opens the door to further applications of reclaimed water to keep supply reservoirs full even during severe droughts.
Benefits of shifting fire protection to reclaimed water
Authors: Digiano Francis A. , Weaver Christopher C. , Okun (Deceased) Daniel A.
Published: February 2018

Health‐based regulations drive up the cost of treatment, but about 50% of system design capacity is for irrigation and toilet flushing for which these regulations are irrelevant. Using reclaimed water to eliminate nonpotable demands reduces plant size, and shifting fire protection to reclaimed water keeps water residence time short in the potable lines to the benefit of water quality. In dual distribution systems, pipe diameters and water residence times are reduced in potable water lines, resulting in less deterioration in water quality. A case study community shows the benefits and costs of integrating fire protection into the nonpotable water lines in a dual system. Although the financial barrier to adoption of a dual distribution system is a challenge, this article provides a template to assess the costs and the benefits that will be useful to many water utilities.
National cost implications of a perchlorate regulation
Authors: Russell Caroline G. , Roberson J. Alan , Chowdhury Zaid , McGuire Michael J.
Published: February 2018

Compared with other drinking water regulatory determinations, the cost implications of a perchlorate maximum contaminant level are relatively low because of the chemical's limited occurrence in source waters in the United States. However, a small number of systems are carrying this cost burden and the cost implications to an individual system having to install perchlorate treatment would likely be significant. Several studies have evaluated the nationwide occurrence of perchlorate in drinking water sources, but to the authors’ knowledge, no study has been conducted evaluating the cost implications for treatment of all perchlorate‐contaminated drinking water sources. This study was undertaken to bridge this information gap in anticipation of discussions about whether to regulate perchlorate at a national level. If the perchlorate regulation is revisited by the U.S. Environmental Protection Agency, this study is expected to be a key building block for subsequent evaluation of the cost implications of a national perchlorate standard. This article provides an initial estimate of costs associated with such a standard. Details can be used as guidelines for water suppliers as they assess the cost implications of installing perchlorate treatment at their utility.
Preventing two types of well clogging
Authors: Van Beek Kees , Breedveld Rob , Stuyfzand Pieter
Published: February 2018

Wells abstracting groundwater are often susceptible to screen slot (chemical) clogging and well bore (mechanical) clogging. Well clogging can cause a decrease of a well—s specific capacity over time and may threaten its reliability. Both types of clogging can be easily diagnosed during operation with the help of entrance resistance—the difference in head between the abstraction well and the observation well in its gravel pack. An increase in entrance resistance over time indicates screen slot clogging. The increasing resistance is caused by accumulation of chemical precipitates in the screen slots and adjacent gravel pack. Well bore clogging, however, does not show an increase in entrance resistance. Both types of clogging can be easily prevented, or at least mitigated, by two opposing methods of well operation: continuous abstraction for wells susceptible to screen slot clogging, and discontinuous abstraction (alternating operation with idle periods) for wells susceptible to well bore clogging.
Application of anion exchange to control NOM interference on lime softening
Authors: Hsu Susan , Singer Philip C.
Published: February 2018

Simulated natural waters with various concentrations of natural organic matter (NOM) were softened using lime precipitation to determine the effects of dissolved organic carbon (DOC) on calcium removal. Water with 8.3 mg/L of DOC showed reduced calcium removal compared with waters with 0 and 1.5 mg/L of DOC and exhibited high degrees of oversaturation before precipitation commenced, providing evidence that NOM interferes with lime softening by inhibiting calcium carbonate nucleation and crystal growth. In 2005, the utility serving the Village of Palm Springs, Fla., implemented a full‐scale magnetic ion exchange (MIEX®) process upstream of its lime‐softening facilities. In this research, anion exchange treatment of simulated natural water and raw water from Palm Springs reduced DOC concentrations from 8.1 to 3.5 mg/L and from 7.7 to 2.1 mg/L, respectively, and therefore was expected to improve the performance of downstream softening. Both waters showed improvement in softening performance after anion exchange treatment with the resin. Analysis of raw and finished water quality at Palm Springs found improved hardness removal after implementation of the MIEX process, even at reduced lime doses.
Managing Water in a Shifting Climate
Authors: Matthews John , Aldous Allsion , Wickel Bart ,   The Nature Conservancy
Published: February 2018

This article discusses the challenges of managing water resources in the context of climate change. New methods are emerging for climate adaptation in managing water resources, and should begin by implementing practices at the forefront of sound water management, such as environmental flows, integrated water resource management, and the preferential use of “soft” over “hard” infrastructure. The article discusses five elements that should be considered when adapting water management programs to climate change, including: holistically assess hydro‐ecologic effects and vulnerabilities; understand thresholds; pursue “basin thinking,” even if actions are focused on a project scale; approach water management from a multidisciplinary perspective; and, consider the institutional challenges presented by climate change.
Women's advancement: One engineering firm's pathway to leadership
Authors: Ibison Meg , Bailey Bob
Published: February 2018

In the traditionally male‐dominated industry of engineering and construction, CH2M HILL provides a model for advancing female employees to achieve business success. The Women's Leadership Initiative uses the company's long‐standing inclusive workplace to accelerate women's advancement and includes internal and external components, including Women's Network Chapters, Women's Leadership Summits, and outreach to philanthropic and community organizations. Since the initiative was launched in 2003, women's representation in CH2M HILL senior leadership positions such as business unit heads, geographic region leaders, and top managers has increased from 2.9 to 18%. The Women's Leadership Initiative illustrates the strong business case for supporting women's advancement to leadership and demonstrates that businesses can benefit from fresh thinking and commitment to making women in the workplace a top priority. The initiative has been so successful that it now provides a model for other workforce diversity efforts, both in the engineering and construction sectors as well as other industries.
Bridging the engineering workforce gap through community outreach
Authors: Kekelis Linda , Gomes Lyn
Published: February 2018

The National Science Foundation has predicted a shortage of 70,000 engineers by 2010. Yet, engineers are needed more than ever to come up with novel solutions to reconcile the ever‐increasing demands on water resources. Through community outreach activities, today's engineers can become role models for middle school and high school students, encouraging them not only to become powerful stewards of water quality and conservation, but also to inspire the students to become tomorrow's engineers. Little information has been available, however, on how to interact effectively with students and keep them engaged during classroom visits and field trips. This article provides engineering firms and water agencies with guidelines that have been proven effective for conducting outreach activities in a classroom or at a worksite. The authors provide field trip schedules, a hands‐on activity to design and build a water filter, scavenger hunt/tour ideas, and sample questions to help stimulate interaction among students and role models.
Occurrence and removal of amino acids during drinking water treatment
Authors: Dotson Aaron , Westerhoff Paul
Published: February 2018

Amino acids (AAs) have been identified as precursors to disinfection by‐products—some more cytotoxic than the currently regulated disinfection by‐products. This study measured occurrences and removals of AAs, amino sugars, and bulk organic matter surrogates (dissolved organic carbon [DOC], dissolved organic nitrogen [DON]) in raw water and filter effluents of 16 full‐scale water treatment plants influenced by algal activity or wastewater discharge. In raw waters, the average concentration of free AAs—those not bound in larger molecules—was very low, 0.69 μg/L N (< 0.5% of the DON). The average concentration of total AAs—those bound and unbound—was 41.1 μg/L N (15% of the DON). The most dominant (on a molar basis) AA species detected were serine, alanine, and glycine. Water treatment removed, on average, 30, 30, 25, and 65% of DOC, DON, free AAs, and total AAs, respectively. This study was the first large‐scale occurrence survey of free and total AAs in United States drinking waters.