bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensory GC analysis of decaying vegetation and septic odors
Authors: Khiari Djanette , Barrett Sylvia E. , Suffet I.H. (Mel)
Published: February 2018

GC–MS is combined with sensory GC analysis to identify chemicals responsible for decaying vegetation and septic odors in drinking water supplies.

A study was undertaken to identify the chemicals responsible for septic and decaying vegetation odors, not only in odor reference standards but also in natural waters. Two complementary extraction methods—closed‐loop stripping analysis and simultaneous distillation extraction—were used. Chemical identification was performed by gas chromatography (GC) with mass spectrometry, and sensory identification was accomplished by flavor profile analysis and sensory GC. Dimethyl disulfide, dimethyl trisulfide, and 2‐isobutyl‐3‐methoxypyrazine were the principal contributors to decaying vegetation odors, whereas dimethyl trisulfide and indole were strongly associated with septic odors. In addition, the study confirmed the presence of these chemicals as well as 2‐isopropyl‐3‐methoxypyrazine (associated with decaying vegetation) in water supplies.
A Center for Excellence
Authors: Hoffbuhr Jack
Published: February 2018

Hoffbuhr envisions AWWA as a clearinghouse that helps utilities and other members learn from each other.
Water availability under the Texas water rights system
Authors: Wurbs Ralph A.
Published: February 2018

Simulation studies of demands on Texas water supplies point to the complexities of administering and modeling a water allocation system.

Texas recently established a surface water rights permit system, similar to those of other western states. A simulation study of the Brazos River Basin identified issues and concerns that illustrate the practical complexities of administering and modeling a water allocation system. Key considerations involve sharing of limited supplies by numerous water users during drought, reservoir storage priorities, multiple‐reservoir system operations, water quality constraints, return flows, hydrologic data compilation, and reliability assessment. The issues affecting evaluation of water availability within the Texas water rights system are representative of other states as well.
Evaluating criteria for enhanced coagulation compliance
Authors: White Mark C. , Thompson Jeffrey D. , Harrington Gregory W. , Singer Philip C.
Published: February 2018

Jar testing of 31 natural waters suggests many utilities may need the proposed alternative performance criterion to comply with enhanced coagulation specified in the proposed D/DBP Rule.

Jar tests were performed on 31 natural waters from a variety of sources across the United States. These tests indicate that the majority of utilities supplying samples will have difficulty meeting the Step 1 total organic carbon (TOC) removal requirements in the Disinfectants/Disinfection By‐products Rule. Utilities may need the proposed point of diminishing returns alternative performance criterion to achieve compliance with the enhanced coagulation requirement. Water sources with high TOC and low alkalinity were most likely to meet the proposed Step 1 TOC requirements. Those with low TOC were most likely to need the alternative performance criterion.
Electronic Communication: A Tool for Small Systems
Authors: O'Neil Jim
Published: February 2018

This article discusses an electronic bulletin board created by the Alaska Section of AWWA for operators in the state, and discusses the importance of electronic communications for small systems.
Leak Detection Cost‐effective and Beneficial
Authors: Leauber Chris E.
Published: February 2018

One of the major contributors to water loss is unknown underground leaks in the distribution system, most of which go undetected for long periods of time. Aggressive leakage control programs can usually locate 50‐75 percent of unaccounted‐for water, which is the difference between the water delivered to the distribution system and the amount of water sold to customers. This article discusses using sonic leak detection, and also the benefits of a leak detection program.
SDWA Limits Lead Content of Plumbing Materials
Authors: Pontius Frederick W.
Published: February 2018

The 1986 Safe Drinking Water Act (SDWA) amendments included Sec. 1417, which was intended to decrease future problems of lead contamination in water systems. The section was amended in 1996 to expand coverage to include the use of leaded plumbing fittings and fixtures (faucets).
Testing the SANCHO model on distribution systems
Authors: Laurent Patrick , Servais Pierre , Prévost Michèle , Gatel Dominique , Clément Bernard
Published: February 2018

A deterministic model to predict microbiological water quality in distribution systems is tested by comparing field data measurements and predicted values obtained through model simulations.

Empirical findings were used to evaluate a deterministic model of bacterial dynamics in a pipe carrying potable water. The SANCHO model simulates the response of fixed and free bacteria in the system to the concentrations of chlorine and organic substrate entering the system. The authors tested the model on seven full‐scale distribution systems and made a study of the error distribution between measured values and the model's predicted values. Various simulation examples demonstrate the usefulness of the model for determining a bacterial regrowth control strategy for distribution systems. Coupled with residence time calculation software, the SANCHO model may become an important decision‐making tool in the management of water distribution systems. The model is particularly useful in that it can help define the reduction thresholds for biodegradable dissolved organic carbon required to maintain a given network's quality objectives as a function of the residence time of the water in the system.
Committee report: transit‐time ultrasonic flowmeters
Authors:   AWWA Subcommittee on Ultrasonic Devices
Published: February 2018

A review of transit‐time ultrasonic flowmeter principles and operation lays the groundwork for development of an AWWA standard on flowmeter selection.

AWWA has not yet developed a standard providing guidelines for selecting transit‐time ultrasonic flowmeters from among the numerous models and designs available. As a first step toward developing such a standard, the AWWA Subcommittee on Ultrasonic Devices, a subsection of the AWWA Committee on Rate Type Flowmeters, has documented the state of the art in transit‐time flowmeters. This report presents committee findings to date for public review and information. The committee welcomes comments from manufacturers, prospective users, and other parties interested in transit‐time flowmeters.
DAF pretreatment: its effect on MF performance
Authors: Braghetta Anne , Jacangelo Joseph G. , Chellam Shankararaman , Hotaling Michael L. , Utne Bruce A.
Published: February 2018

A pilot study suggests that DAF pretreatment helps reduce membrane fouling in hollow‐fiber MF.

A pilot study investigated the use of dissolved air flotation (DAF) as a pretreatment to hollow‐fiber microfiltration (MF). Results showed that DAF‐pretreated feedwater achieved longer MF runs than raw feedwater. MF performances with DAF‐pretreated water were compared for fluxes of 70, 90, 110, and 135 gfd (120, 155, 190, and 230 L/m2/h). Performance results indicated that MF run lengths of more than 30 days could be achieved at flux conditions of 70 and 90 gfd (120 and 155 L/m2/h), with run lengths of 21 and 10 days for fluxes of 110 and 135 gfd (190 and 230 L/m2/h). Experimental results from this pilot study were also interpreted using a mathematical model to determine MF backwash efficiency at the different flux conditions. Both the experimental and modeling results suggest that membrane fouling by the DAF‐pretreated water was characterized by reduced pore blockage and lower cake compressibility as compared with treatment of raw feedwater.
The Revolving Loan Fund
Authors: Pontius Fred
Published: February 2018

Roundtable participants explain how to apply for funds from the drinking water state revolving fund.
Reduction of microscopic particulates by aquifers
Authors: Gollnitz William D. , Clancy Jennifer L. , Garner Stephen C.
Published: February 2018

The authors introduce a method for evaluating natural reduction of microscopic particulates in aquifers that store groundwater under the direct influence of surface water.

Many water utilities operate collection devices constructed in alluvial‐valley aquifers. Pumping groundwater from these systems may induce infiltration of surface water containing pathogenic protozoa. However, the porous sand and gravel of this kind of aquifer can significantly reduce the number of microscopic particulates that pass through the aquifer media. A method is proposed for evaluating the natural reduction efficiency of porous‐media aquifers, taking into consideration the transport of particulates through the aquifer during a period of maximum infiltration. The method allows regulators to estimate the risk of pathogenic protozoa, determine the log‐reduction credit warranted by the water's transport through the aquifer, and determine the type of treatment needed for the source.
COMMITTEE REPORT: Climate change and water resources
Authors:   AWWA's Public Advisory Forum
Published: February 2018

Global warming is a fact, and water resource managers need to plan accordingly.

Global climatic change—the greenhouse effect—is here to stay. Although uncertainties remain about the nature and extent of climatic changes that will occur, most among the scientific community believe changes in the hydrologic cycle and to water resource management systems will be significant. Water managers, policy‐makers, and the public should begin to consider the implications of climatic change for long‐term water planning and management. AWWA's Public Advisory Forum has discussed this problem for the past two years. The recommendations it offers in this article are not for specific changes in operations, for complicated or costly new infrastructure or development, or for irreversible actions. Instead, they are recommendations for thoughtful analysis of water systems' vulnerabilities to unprecedented climate change and for attention, planning, and continued vigilance in response to this situation. As the proverb says, to see the future is good, but to prepare for it is better.
Slow Sand Filtration: Still a Timeless Technology Under the New Regs?
Authors: Tanner Stephen A.
Published: February 2018

Amendments to the Safe Drinking Water Act (SDWA) of 1996 require the US Environmental Protection Agency (USEPA) to develop new rules to control Cryptosporidium and chemical byproducts of the disinfection process. This may force operators to evaluate whether their current practices will still be technologically sound when the new rules take effect. One such process under scrutiny is slow sand filtration. This article describes what slow sand filtration is, and how it is viewed by operators, state regulators, and the USEPA.
Evaluating particle counters
Authors: O'Shaughnessy Patrick T. , Barsotti Michael G. , Fay James W. , Tighe Scott W.
Published: February 2018

Comparisons of particle counts made by counters and counts made by microscopic processes suggest counters accurately indicate removal efficiency.

Particle counting methods for use in a water treatment facility were analyzed to compare counts made by a particle counter with a forward‐angle light scatter (FALS) sensor with counts made with a scanning electron microscope and by microscopic particulate analysis. A separate study compared an FALS sensor with a light obscuration sensor when challenged with latex spheres and cultured microorganisms and when performing continuous in‐line counts of the facility's filter effluent. Log removal values were comparable among the particle counting methods and did not vary significantly across various size ranges of an FALS sensor. Microorganisms were undersized by both sensor types compared with sizes determined with an optical microscope. These results suggest counters accurately indicate facility particle removal efficiency. However, counts made by a particle counter within a specific size range should be interpreted after characterizing the nature of the particles in the source
Water quality reports boost consumer confidence
Authors: Jordan Charles G.
Published: February 2018

The consumer confidence report, which is really a water quality report, is an opportunity to communicate with customers.

By late 1998, according to provisions in the reauthorized Safe Drinking Water Act, all community water systems will be required to produce an annual consumer confidence report—really a water quality report—for their customers. Consumers will gain confidence if they learn what their drinking water contains, how it might affect them, and what the utility is doing about potential problems. Utility managers should approach this report more as a communication exercise than a technical exercise. Simplicity is the key to providing an effective water quality report for customers. This article describes how a water system can produce a consumer confidence report that informs customers and complies with the law.
Bubbling to the surface: public water supply issues
Authors: Bishop Bojinka
Published: February 2018

Water suppliers are grappling with drinking water issues that fundamentally affect public policy.

Significant forces including public criticism and publicity about water quality problems have caused public issues about water supply to be raised. Consequently, the “silent service” has begun a dialogue with the public. Currently, the industry's voice is only a whisper, and sometimes it's hoarse, but progress has been made—especially on the local level. For more effective analysis and response, this article characterizes public water supply issues as outsider, insider, local, and latent. Because many of these issues are fundamental to sound social and public policy, the water supply industry should play a more active role in setting public policy.
Public affairs step by step
Authors: Faulkner‐Vaughn Linda
Published: February 2018

The author spotlights innovative public affairs activities and offers step‐by‐step instructions for creating a public affairs program.

Public affairs programs come in all shapes and sizes. From large utilities like the East Bay Municipal Utility District in Oakland, Calif., to small‐town operations like the Georgetown County (S.C.) Water and Sewer District, utility managers across the United States are realizing that public affairs is an important component of a water provider's operation. Conversations with program directors show that public affairs programs may have similar components, but each is unique in how it responds to the needs, demands, and interests of the particular community it serves.
Deposition and retention of bacteria in backwashed filters
Authors: Hozalski Raymond M. , Bouwer Edward J.
Published: February 2018

Biomass accumulation in laboratory‐scale filters is not impaired by backwash with water alone.

Experiments tracked the deposition of two model bacteria—Pseudomonas aeruginosa and Klebsiella pneumoniae—onto clean filter media (i.e., glass beads and filter sand) and the subsequent removal of the bacteria by backwashing. The ability of bacteria to accumulate and be retained in a frequently backwashed filter is critical for effective removal of biodegradable organic matter in a process termed biofiltration. Column filtration experiments showed that the bacteria, especially P. aeruginosa, readily attached to the filter media during filtration, despite unfavorable chemical conditions. Water backwash was not effective at removing bacteria from the filter media, with only 20–40 percent removal during 10‐min backwash cycles at hydraulic loading rates ranging from 23 to 53 m/h (9.3 to 22 gpm/sq ft) and bed expansions ranging from 15 to 50 percent. Incomplete removal of biomass during backwashing was beneficial for removal of biodegradable total organic carbon, typically allowing a backwashed biofilter to maintain treatment at levels similar to the period immediately preceding the backwash.
An Armada of Regulations
Authors: Hoffbuhr Jack W.
Published: February 2018

In his column, AWWA Executive Director Jack Hoffbuhr discusses the history of drinking water regulations in the United States and shows how, as the country has grown, so has the number and complexity of regulations. The need for a new approach in the regulatory process is advocated since contaminant‐by‐contaminant regulation will not effectively protect public health in the long run.
Regulatory Update for Small Systems
Authors: Curry Scott G.
Published: February 2018

This article discusses how small systems can take advantage of the new emphasis on source water protection, consumer education and involvement, and increased funding opportunities as provided by the 1996 Safe Drinking Water Act (SDWA) amendments. The article specifically discusses capacity development, source water assessment and protection, consumer confidence reports, and funding.
How safe is safe?
Authors: Miller Kenneth J.
Published: February 2018

Should water utilities be required to produce drinking water that is safe for everyone, including immunosuppressed people?
New horizons in federal regulation
Authors: Pontius Frederick W.
Published: February 2018

New requirements and schedules have dramatically accelerated the pace of regulatory activity.

The US Environmental Protection Agency is in the process of responding to the mandates imposed by the 1996 Safe Drinking Water Act amendments. New requirements and regulatory schedules have dramatically accelerated the pace of regulatory activity. Several new rules are mandated, such as those that cover microorganisms and disinfection by‐products, arsenic, uranium, radon, groundwater disinfection, and filter backwash recycling. New contaminants for regulation will be identified using a listing process through which the agency will decide whether candidate contaminants warrant regulation.
Cost to utilities of a lower MCL for arsenic
Authors: Frey Michelle M. , Owen Douglas M. , Chowdhury Zaid K. , Raucher Robert S. , Edwards Marc A.
Published: February 2018

Water utilities need to begin now to evaluate their costs for complying with a lower MCL for arsenic.

Compliance with a revised arsenic maximum contaminant level (MCL) for drinking water will require a substantial cost to water suppliers in the United States. A rigorous methodology was developed to estimate the national cost of complying with alternative regulatory limits for arsenic. This methodology considered the feasibility of available technologies based on existing treatment at utilities that are not in compliance and the level of water quality constituents that limit technology performance. A least‐cost method of selecting treatment alternatives was used to estimate compliance costs and the results were extrapolated nationally. Estimated national compliance costs ranged from $330 million per year for a 20‐μg/L MCL to more than $4.1 billion/year for a 2‐μg/L MCL. These estimates represent a 10‐ to 20‐fold increase in the US Environmental Protection Agency's (USEPA's) preliminary cost estimates. Although the effect on small systems would be substantial, this study found that the cost burden would be shared equally between small (<10,000 people served) and large (>10,000 people served) systems. USEPA also found that systems using groundwater would bear more of the total costs (62 to 82 percent) than systems using surface water.
Considerations in As analysis and speciation
Authors: Edwards Marc , Patel Sapna , McNeill Laurie , Chen Hsiao‐wen , Frey Michelle , Eaton Andrew D. , Antweiler Ronald C. , Taylor Howard E.
Published: February 2018

A modified field technique can quantify particulate As, soluble As(III), and soluble As(V) in drinking water.

Several problems with commonly used techniques that analyze for arsenic are reported, and solutions are proposed. Analytical techniques can accurately detect <0.5 μg/L total arsenic if certain conditions are met: iron, nitrate, and other interferences are overcome in hydride generation techniques, poor recoveries are overcome in graphite furnace atomic adsorption techniques, and chloride interferences are accounted for in inductively coupled plasma mass spectrometry techniques. Because no techniques adequately preserve arsenic species during storage, a speciation protocol that is fast (about 5 min/sample), relatively inexpensive (about $10/resin column), and user‐friendly and that can be applied in the field was developed. Particulate arsenic represents a significant fraction of total arsenic in drinking water.
A Balanced View of Chlorine Dioxide
Authors: Gates Don J.
Published: February 2018

In this article, the author attempts to provide a balanced view of the value of chlorine dioxide as an alternative disinfectant for drinking water. Despite the advantages of chlorine dioxide as an adjunct to free or combined chlorine, water suppliers, consultants, and academic and regulatory professionals continue to express concern about its potential health effects. This article discusses the major health effects of chlorine dioxide and offers practical ways to reduce the potential risks associated with its use.
Route restructuring reduces meter‐reading costs
Authors: Bienlien Kent D. , Adams Daniel J. , Cunningham Brian S.
Published: February 2018

Computer software makes restructuring a much faster process and meter‐reading less costly.

Restructuring meter routes is one way to increase productivity and efficiency and reduce costs. The route restructuring trial described in this article was designed to quantify the benefits of using commercial restructuring software. The cost to read a meter before route restructuring (based on an average of 224 meters per day) was estimated at $0.958; after restructuring, it was $0.699 (307 meters per day), a 27 percent reduction in labor costs. Labor cost to restructure the routes was reduced by an estimated 83 percent. Used effectively, route restructuring software increases the productivity of meter readers and efficiently tracks and manages all aspects of the work.
Dewaterability of alum and ferric coagulation sludges
Authors: Thompson Phillip L. , Paulson Wayne L.
Published: February 2018

Ferric sulfate sludges demonstrated superior dewaterability over sludges formed by coagulation with aluminum.

Tighter regulations governing stream discharge of coagulation sludge from the primary sedimentation process prompted the University of Iowa Water Treatment Plant to consider sludge‐handling options. This pilot study was undertaken in order to investigate differences in the mechanical dewatering of sludges formed by using either alum or ferric sulfate coagulants. The approach used various volumes of wasted lime sludge produced from the plant's softening process as a filtering aid. After the short pilot study, dewatering data from a bench‐scale plate‐and‐frame filter press indicated that ferric sludge was easier to dewater than sludges formed by coagulation with alum. The addition of lime‐softener sludge increased the dewaterability of all sludges tested, primarily by increasing the sludge feed solids concentration, which may have also decreased blinding.
Greater Funding Opportunities for Small Systems
Authors: Bourne James
Published: February 2018

This article discusses the considerable obstacles facing small communities that want to improve their drinking water infrastructure. Specifically, the article discusses the establishment of the Drinking Water State Revolving Fund (DWSRF) as part of the 1996 Safe Drinking Water Act (SDWA) amendments, and how the program provides additional options and flexibilities for smaller, less affluent systems to more easily afford the construction costs associated with needed infrastructure improvements.
Oregon's SDWRLF gets under way
Authors: Leland Dave , Wise Doug
Published: February 2018

Oregon takes a step‐by‐step approach to setting up a state drinking water revolving loan fund.

The 1996 Safe Drinking Water Act amendments established a Drinking Water State Revolving Fund (DWSRF) to help states and their community drinking water systems meet regulations. Oregon's efforts to secure and administer its share of the DWSRF led to the design and development of the state Safe Drinking Water Revolving Loan Fund (SDWRLF). The SDWRLF program was developed over the course of 18 months in close cooperation with the Oregon Drinking Water Advisory Committee, the Oregon Health Division, the Oregon Economic Development Department, and the Oregon Department of Environmental Quality. The design that emerged from their collaborative contributions represents a significant effort to improve and protect public drinking water systems in the state.
SDWA capacity development
Authors: Shanaghan Peter E. , Kline Ian P. , Beecher Janice A. , Jones Ralph T.
Published: February 2018

Using stakeholder comments, USEPA is creating guidance and information to smooth implementation of SDWA capacity development provisions.

The capacity development provisions of the 1996 Safe Drinking Water Act offer a flexible framework within which states and water systems can work together to ensure that systems acquire and maintain the technical, financial, and managerial capacity needed to consistently achieve the public health protection objectives of the act. Capacity development is related to the Drinking Water State Revolving Fund (DWSRF) in two important ways: states may set aside funds from their DWSRF allotments to develop and implement capacity development programs, and the US Environmental Protection Agency (USEPA) is required to withhold DWSRF funds from states that fail to implement the capacity development provisions. USEPA's implementation of the capacity development provisions is being guided by an unprecedented process of stakeholder consultation and involvement.
From Mouse to Man
Authors: Hoffbuhr Jack W.
Published: February 2018

In his monthly column, Executive Director Jack Hoffbuhr of the American Water Works Association (AWWA) discusses an article in USA Today which initially reported that a cure for cancer was imminent, but then advised caution since the tests had only been conducted on mice. The interpretation of animal tests in determining the potential carcinogenicity of chemicals is questioned.
Building a Winning Team
Authors: Siburg David R.
Published: February 2018

This article describes how Vince Lombardi's formula for success in the National Football League ‐ attitude, attention to detailed evaluations, and disciplined preparation ‐ can be used by small system managers to help move their utilities forward by stimulating new ideas and incorporating changes to be monitored against identified performance standards.
Implementing a DBO project
Authors: Kelly Elizabeth S. , Haskins Scott , Reiter Paul D.
Published: February 2018

The process of implementing Seattle's Tolt design‐build‐operate project provides a road map for other utilities interested in alternative contracting approaches.

The city of Seattle, Wash., used an innovative public‐private partnership to develop its first water filtration plant. The new Tolt treatment facilities will increase system reliability and flexibility by allowing continuous operation of Seattle's Tolt source through periods of high turbidity. It will also improve system yield and allow long‐range compliance with anticipated regulations. As an alternative to the conventional public works procurement process, Seattle created a design‐build‐operate (DBO) model to provide reliable, cost‐effective project development while maintaining public ownership of the facility. The DBO contract is valued at $101 million, which represents a savings of $70 million over the $171‐million estimated cost of developing the same facility using conventional design‐bid‐build procurement with city operations for 25 years. The Tolt facility, expected to be operational in late 2000, will be a 120‐mgd (45 106‐m3/d) filtration and ozonation plant for treatment of Seattle's Tolt River source of supply, which provides about a third of the water for Seattle and its 26 regional wholesale customers.
Detection limits of organic contaminants in drinking water
Authors: Draper William M. , Dhoot Jagdev S. , Dhaliwal Joginder S. , Remoy John W. , Perera S. Kusum , Baumann Frank J.
Published: February 2018

Better control of MDL determination will substantially reduce interlaboratory variation.

This article examines some of the experimental variables that can contribute to the observed variability in laboratory performance. The examples provided suggest that method detection limits (MDLs) would be more uniform among laboratories if (1) uniform spike concentrations were used in MDL determination; (2) analytical methods were more uniform as to procedures, reagents, and materials; and (3) tighter guidelines were established for conducting MDL experiments and handling MDL data. The pooling of data from multiple spike levels (or any other means to increase sample size) minimizes random error in MDL determination. Improved control in MDL determination would lead to better information on laboratory capabilities, and this in turn would improve the technical basis for reporting limits, trigger levels, and water quality standards.
The Coming Crisis
Authors: Hoffbuhr Jack W.
Published: February 2018

In his column, AWWA Executive Director Jack Hoffbuhr touches on how electronic publishing will impact the traditional publishing medium ‐ paper ‐ and jests about the coming crisis: what will be done with all of the National Geographic magazines hoarded around the world now that you can purchase the complete set on a single CD‐ROM?
Mentors
Authors: Hoffbuhr Jack W.
Published: February 2018

In his column, AWWA Executive Director Jack Hoffbuhr discusses the importance of mentoring in employee development.
Small system maintenance management using GIS
Authors: Kaufman Martin M. , Wurtz Matthew
Published: February 2018

It took only three months and less than $3,000 to develop this comprehensive maintenance management system.

A geographic information system (GIS) was developed for maintenance operations at a small (6,104 customers) utility district. Characteristics unique to GIS applications, such as the accurate modeling of physical and environmental processes, data modeling and preparation, and the spatial nature of the data, were incorporated into the steps used to develop the system. The steps were problem identification, process modeling, data modeling, developing a data plan, cartographic modeling, data entry, and testing. These steps achieved computability—the transition from a real‐world problem to a computer application. The results give an accurate depiction of the water supply processes, including the hydraulic characteristics of the infrastructure and the service requirements. This low‐cost application was implemented rapidly and has the flexibility to create additional applications.
Waterborne outbreaks of cryptosporidiosis
Authors: Craun Gunther F. , Hubbs Stephen A. , Frost Floyd , Calderon Rebecca L. , Via Steve H.
Published: February 2018

A review of 35 outbreaks of cryptosporidiosis points to recommendations for prevention of waterborne outbreaks and uncovers a need for more adequate epidemiological data.

Cryptosporidium parvum infection occurs worldwide in urban and rural populations, and waterborne outbreaks have been associated with consumption of contaminated drinking water and water during recreational activities. This article reviews the epidemiology and causes of waterborne outbreaks that have been reported in North America and the United Kingdom. Outbreaks were associated with filtered and unfiltered surface water sources, groundwater sources, and contamination of the distribution system. In most outbreaks, sources of contamination and deficiencies in treatment and operation were identified. Available epidemiological information is inadequate to estimate endemic waterborne risks, and analytical studies should be conducted to assess these risks. A major issue to consider in assessing waterborne cryptosporidiosis risks is the role of protective immunity, which may be acquired through low‐level sporadic exposures to C. parvum in drinking water.
Cost of advanced UV for inactivating crypto
Authors: Dyksen John E. , Marshall Marilyn M. , Gera Arun , Clancy Jennifer L.
Published: February 2018

Cost comparisons indicate that advanced UV technology may be cost‐effective for drinking water treatment and competitive with other treatment alternatives.

A collaborative project funded by the AWWA Research Foundation and the Electric Power Research Institute evaluated five electrotechnologies for their ability to inactivate viable Cryptosporidium oocysts. Advanced ultraviolet (UV) light technology was found to provide greater than 4‐log inactivation of Cryptosporidium. This UV technology was evaluated further from an engineering design and economic standpoint to determine the feasibility of implementing it at existing treatment facilities. This article describes the results of the engineering and economic analyses for advanced UV electrotechnology.
Controlling Legionella using copper‐silver ionization
Authors: States Stanley , Kuchta John , Young William , Conley Louis , Ge John , Costello Michael , Dowling John , Wadowsky Robert
Published: February 2018

Nursing homes as well as hospitals are at risk for Legionella contamination.

Hospital‐acquired Legionnaires' disease, associated with contaminated hot water plumbing systems, is a well‐documented problem in hospitals and may also be a problem in nursing homes. In this study, four nursing homes were surveyed to determine the extent to which potable hot water systems were colonized by Legionella pneumophila and to measure microbial and chemical factors related to legionellae contamination. The survey indicated that two of the homes were heavily contaminated with Legionella and suggested that contamination is associated with hot water temperatures, chlorine concentrations, the presence of free‐living amoebae, and possibly intermittent seeding of building plumbing systems with legionellae from the public water supply. The most heavily colonized nursing home plumbing system was then equipped with a copper‐silver ionization device, designed to control Legionella. A subsequent two‐year evaluation indicated that the device controlled Legionella but not amoebae or non‐Legionellaceae bacteria. Maintenance of the ionization system and monitoring of legionellae and metals concentrations in the water are important for effective use of the control device.
Operator Certification Is Coming of Age
Authors: Way Eric J.
Published: February 2018

Small systems will face the biggest challenges as the bar is raised on training and education.
Sulfide‐oxidizing bacteria: their role during air‐stripping
Authors: Dell'Orco Michael J. , Chadik Paul A. , Bitton Gabriel , Neumann R.P.
Published: February 2018

Biological oxidation of sulfide enhances the removal of sulfide from groundwater by diffused aeration.

Air‐stripping, used to remove hydrogen sulfide naturally present in many groundwater supplies, commonly causes sulfideoxidizing bacteria to proliferate. The role of sulfide‐oxidizing bacteria during air‐stripping was investigated in a diffused‐air pilot reactor modeled after an existing treatment facility. Visible bacterial filaments and biofilm developed within a few days and increased both the sulfide removed from and turbidity in the effluent. Total sulfide, dissolved oxygen, pH, and electrode potential were monitored at eight locations in the reactor to characterize the process.
Complying With USEPA's Consumer Confidence Report Rule
Authors: Pontius Frederick W.
Published: February 2018

This article discusses the final Consumer Confidence Report (CCR) Rule, which ties together several aspects of the amendments to the 1996 Safe Drinking Water Act (SDWA) that are intended to provide consumers with more information about drinking water. Topics discussed include: key CCR compliance dates; content specification; delivery and record‐keeping requirements; required information for the CCR; estimated compliance costs; and, compliance tools. A CCR compliance checklist is also provided.
Tokyo's modern water system celebrates its centennial
Authors: Kawakita Kazunori
Published: February 2018

The city's Bureau of Waterworks has made strides in purifying and conserving water, meeting demand, upgrading pipelines, and preparing for earthquakes.

In 1898, Tokyo, Japan, modernized its then 300‐year‐old water supply system by building a slow sand filtration plant. The modernized system has come a long way and is celebrating its one hundredth anniversary in 1998. This article highlights the triumphs and tribulations Tokyo has faced over the years in delivering drinking water to its citizens. It covers the development of the dams, reservoirs, and rivers used to secure water; Tokyo's Bureau of Waterworks; efforts to conserve water; upgrades to the distribution system; and emergency preparations for responding to earthquakes.
Using PAC–UF to treat a low‐quality surface water
Authors: Jack Anne M. , Clark Mark M.
Published: February 2018

In a pilot study, a PAC‐UF process shows promise in treating a low‐quality source water without sacrificing either cost or operating efficiency.

A water supply from a Midwestern agricultural watershed was treated using a hybrid powdered activated carbon‐ultrafiltration (PAC‐UF) pilot system. The pilot was operated remotely over a four‐month period using five combinations of target flux and backwashing frequency. Simple statistical techniques were used to analyze energy and cost efficiency for each combination. Energy use was minimized when target flux and the period between backwashes were minimized. Total cost was minimized when the target flux and period between backwashes were maximized. A degradation in water quality at the end of the pilot‐testing period presented a significant operational challenge that was overcome through the direct addition of 14 mg/L ferric chloride to the UF recirculation loop. The sudden degradation in water quality is testimony to the need for pilot tests designed to evaluate the effects of seasonal water quality variations.
Tracking filter performance with particle counting
Authors: Hargesheimer Erika E. , McTigue Nancy E. , Mielke J. Laurie , Yee Phillip , Elford Tom
Published: February 2018

Particle counting can be a sensitive tool for monitoring filter performance and improving the quality of finished water.

Minor changes (1–2 mg/L) in the primary coagulant dosage can significantly affect particle counts in filtered water. Jar tests were inconclusive in selecting a coagulant dosage for source water of low turbidity (<5 ntu). Measurements of turbidity in filtered water were also not definitively altered by small changes in coagulant dosage. On‐line particle counting was successfully used in a 0.5 × 106–m3/d (135‐mgd) conventional water treatment plant to distinguish the effects on water quality of small changes in coagulant dosage and filter flow. Measurable changes in particle counts in filtered water were detected when the aluminum sulfate dosage ranged from 5 to 10 mg/L at filter loading rates of 4–9.5 m/h (1.7–4.0 gpm/sq ft). Particle count percentile plots and statistics (10th, 50th, 90th, 95th, and 98th percentiles) were valuable indicators of the performance of both individual filters and the overall plant.
A Fork in the Road
Authors: Hoffbuhr Jack W.
Published: February 2018

In this column, AWWA Executive Director Jack Hoffbuhr explores the AWWA Water Utility Council's answers to questions about future trends for the drinking water profession. A key issue is the public distrust of government institutions. To combat this, water utilities must develop a culture based on communicating with and involving their consumers, governing boards, and other stakeholders to establish trust and credibility. Also, regulatory officials and elected representatives must also make an effort to involve the public in discussions about drinking water, where it fits in the overall public health picture, and the course that future regulation should take. A key issue should be how to best regulate drinking water. The current contaminant‐by‐contaminant method is showing the strain of too many contaminants for the available science. There is not enough scientific data to establish sound contaminant levels for many substances. Consumer driven programs for addressing public health are being instituted by utilities. Partnership for Safe Water and QualServe use local solutions to meet national public health objectives. They are an example of how to develop a successful regulatory program that does not depend on a contanimant‐by‐contaminant approach.
Federal Facilities Subject to SDWA Regulations
Authors: Pontius Frederick W.
Published: February 2018

The revised federal facility provisions of the 1996 Safe Drinking Water Act (SDWA) amendments mean that federal agencies must plan carefully so that compliance with SDWA regulations is achieved within the specified time. Federal facilities will be treated in the same manner as nongovernmental entities and must abide by compliance schedules and reporting requirements to avoid enforcement action from the U.S. Environmental Protection Agency or the primacy state or from citizen suits.
The disinfectant residual dilemma
Authors: Clement Jonathan A.
Published: February 2018

European and American experts agree that more research is needed to understand how maintaining a residual affects public health, biological stability, treatment practices, and, ultimately, the consumer.
European regulations on residual disinfection
Authors: Hydes Owen
Published: February 2018

Even though European countries vary in their disinfection practices, they must hit the same microbiological targets set by a formal drinking water directive.

This article describes the relevant requirements of the European Community Drinking Water Directive and outlines how the European Union's 15 member states and Switzerland have implemented them. European countries vary considerably in their national requirements or guidance on disinfection and the use of disinfectant residuals within the distribution system. Although a few European countries require all water supplies to be disinfected and a disinfectant residual to be maintained, some countries do not require disinfection or the use of a disinfectant residual. Some countries adopt intermediate positions, and many countries have exceeded the directive's requirements. A number of factors influence countries' practices, including the nature and quality of their water sources, meteorological conditions, the degree of treatment provided to remove impurities, concern about disinfection by‐products, and the operation and condition of the distribution system. A recently agreed on new Drinking Water Directive is also described.
Legacy
Authors: Hoffbuhr Jack W.
Published: February 2018

In this column, AWWA Executive Director Jack Hoffbuhr outlines the history of waterborne disease and the development of the science of epidemiology. He urges public health professionals to continue to assist developing countries to improve water treatment and sanitation through programs such as Water For People, and to keep striving to develop treatment methods to control long‐term health effects.
Y2K: Are Small Systems Ready?
Authors: Jesperson Kathy
Published: February 2018

This article outlines what small systems need to do to address the Y2K problem. First, identify all the computer‐supported operations of the system, such as backwashing and supervisory control and data acquisition (SCADA) telemetry systems. Second, determine whether any of these operations use a “real‐time” clock function, which relies on the exact calendar day of the year. Also, in regards to billing software, it would be important to require certification from the billing software vendor that their products are Y2K compliant. It is also recommended that small system managers require all purchase orders to contain language that requires equipment to be Y2K compliant. A checklist prepared by the Federal Reserve Board and recommended by the Small Business Administration is provided, along with websites that offer detailed information about Y2K compliance.
Enforcement Policy Issued for Y2K Testing
Authors: Pontius Frederick W.
Published: February 2018

The US Environmental Protection Agency (USEPA) has issued an enforcement policy designed to encourage water utilities, companies, and other facilities to promptly test computer‐related equipment to ensure that environmental compliance is not impaired by the year 2000 (Y2K) problem. The agency intends to waive 100 percent of the civil penalties that might otherwise apply and to recommend against criminal prosecution for environmental violations caused during specific testing designed to identify and eliminate Y2K‐related malfunctions. This policy is limited to testing‐related violations disclosed to USEPA by February 1, 2000, and is subject to certain conditions, which are discussed in this article.
Surfing the Web for water quality data
Authors: DeNileon Gay Porter
Published: February 2018

Water quality information on the Internet is increasing every day, but questions persist about the data's reliability, accessibility, and timeliness.

The Internet offers water professionals widespread opportunities to disseminate and obtain water quality data. As part of a US Environmental Protection Agency pilot project, the Des Moines (Iowa) Water Works is posting its finished water quality data in real time on the World Wide Web. Some utilities have also instituted Web sites; others are still in the process of determining the type and extent of information to post on the Internet. This article cautions water professionals about the pitfalls associated with cyberspace data—notably inaccuracy and inaccessibility— and briefly describes the major sites providing water quality information.
Ferric chloride plus GAC for removing TOC
Authors: Nowack Kirk O. , Cannon Fred S. , Arora Harish
Published: February 2018

Ferric chloride extends GAC bed life and prevents calcium buildup.

Granular activated carbon (GAC) treatment is one method that water utilities can use to increase removal of natural organic matter and comply with the recently promulgated Disinfectants/ Disinfection By‐products Rule. The cost of GAC depends on its useful service life and its capacity for reuse. The research reported here used minicolumns to investigate how ferric chloride coagulation influenced the total organic carbon (TOC) subsequently removed by GAC. Ferric chloride pretreatment lengthened GAC bed life by lowering influent TOC and by rendering the TOC that remained more adsorbable. Jar tests showed that at pH < 6.0, ferric chloride was superior to aluminum salts, on an equimolar basis, for removing TOC.
Arsenic treatment considerations
Authors: Chen Hsiao‐wen , Frey Michelle M. , Clifford Dennis , McNeill Laurie S. , Edwards Marc
Published: February 2018

The least‐cost method of removing arsenic may not be the best method all around.

The best arsenic treatment technique for a given utility will depend on arsenic concentration and species in source water, other constituents in the water, existing treatment processes, treatment costs, and handling of residuals. To evaluate these issues, a national survey investigated arsenic occurrence and speciation in US drinking water sources. In general, total arsenic concentration was higher in groundwater than in surface water supplies. Particulate arsenic was more abundant than previously suspected, and more arsenate than arsenite was present. The cost of arsenic treatment increased in the following order: modified conventional treatment << activated alumina or anion exchange < reverse osmosis. Nevertheless, the most cost‐effective treatment still might not be best, because secondary treatment benefits and residuals handling should also be taken into account.