bluuebunny/crossref_metadata_2025 huggingface dataset:
Small System Compliance Technology for the SWTR
Authors: Pontius Frederick W.
Published: February 2018

Before the 1996 Safe Drinking Water Act (SDWA) amendments were passed, cost assessments to determine treatment technology feasibility were based on effects that would be experienced by regional and large metropolitan water systems. This approach was initially established in the 1974 SDWA and was retained in the 1986 SDWA amendments. However, feasible technologies for large systems may not be appropriate for small systems. This article discusses treatment technologies for categories of small systems for the Surface Water Treatment Rule.
Integrated membrane treatment in Alaska
Authors: Lozier James C. , Jones Greg , Bellamy William
Published: February 2018

An integrated membrane system for a surface water supply in Barrow, Alaska, combines microfiltration and nanofiltration.

An integrated membrane treatment process consisting of microfiltration followed by nanofiltration is producing potable water in Barrow, Alaska. The process was selected to address treatment of surface water that is cold, highly colored, of low turbidity, and relatively soft with moderate alkalinity. The water has supersaturated concentrations of dissolved gases, high concentrations of natural organic material including disinfection by‐product precursors, and significant concentrations of Giardia and Cryptosporidium. The dual‐membrane process produces finished water that exceeds current and anticipated regulatory requirements at minimal operating complexity and cost.
Effect of pretreatment on surface water nanofiltration
Authors: Chellam Shankararaman , Jacangelo Joseph G. , Bonacquisti Thomas P. , Schauer Barbara A.
Published: February 2018

A pilot study using integrated membrane systems suggests that MF or UF pretreatment may be necessary to reduce fouling during NF of surface water.

An integrated membrane system pilot study compared microfiltration (MF), ultrafiltration (UF), and conventional treatment as pretreatment strategies for surface water nanofiltration (NF) using spiral‐wound elements. MF and UF pretreatment resulted in lower NF fouling rates and longer cleaning intervals compared with those measured following conventional treatment. NF fouling rates evaluated under a wide range of hydrodynamic conditions following conventional treatment suggest NF fouling is more influenced by permeate flux than by feedwater recovery. NF was shown to be capable of meeting all current and anticipated trihalomethane and haloacetic acid regulations.
Urban Water Supply: The Next 100 Years
Authors: Personett Mike
Published: February 2018

As the 21st century approaches, questions are beginning to arise regarding the future of water supply in the United States. A US Census Bureau forecast projects an increase of 129 million people in the United States by the year 2050. Such an increase in water demand could eventually translate into chronic water shortages affecting both the quality of life and the economic well‐being of much of the population. This article expresses the opinion of the author on the importance of making urban water supply in the 21st century a national public policy priority.
Overview of SDWA Source Water Protection Programs
Authors: Pontius Frederick W.
Published: February 2018

The Safe Drinking Water Act (SDWA) amendments of 1996 are replete with provisions that expand current efforts to protect source water. As a result, source water protection has become a national priority. The US Environmental Protection Agency (USEPA) has set as a goal that local source water protection programs be in place by 2005 to protect water supplies in 30,000 communities that serve 60 percent of the US population. This article discusses the six major programs now existing under the SDWA related to source water protection: underground injection control, sole source aquifer, wellhead protection, source water assessment, source water petition, and comprehensive groundwater protection grants. Although each of these programs is administered by the USEPA, state and local involvement are key to their success.
State and regional water planning in Texas
Authors: Bagwell Tony , Personett Mike
Published: February 2018

The state water plan is an important guide for state policy‐makers, as well as regional and local water planners and managers.

Because of an extreme drought during the 1950s, Texas made statewide water supply planning a policy priority. The Texas Water Development Board was created to provide organizational and financial assistance to local and regional water suppliers. Over the past 40 years this planning effort has evolved in response to a variety of changing conditions. The comprehensive Texas Water Plan, based on a consistent framework of planning data and forecasts, was developed with significant regional and local participation. The plan challenges state leaders, water managers, and the general public to take the necessary and often controversial or innovative actions to meet the state's water needs for the next 50 years in a timely, cost‐effective, and environmentally sensitive manner.
The Willamette—a river in peril
Authors: Leland David , Anderson Steven , Sterling Danold J.
Published: February 2018

The future health of the river depends on actions taken today.

The overall health of the Willamette River is slightly better than marginal. The health of the river in the future depends on action taken today: it can be maintained or improved with active effort, or it can be allowed to decline. That picture emerged from the Willamette River Basin Water Quality Study. The five‐year study adapted established study methods and water quality models to a major river system. It was funded and carried out by a combination of agencies and stakeholders.
Alternative Monitoring Guidelines Released
Authors: Pontius Frederick W.
Published: February 2018

On August 6, 1997, the US Environmental Protection Agency (USEPA) issued guidelines for alternative monitoring, formerly known as permanent monitoring relief. This article describes these guidelines, including: sampling waivers allowed for chronic contaminants; surrogate sampling points; reduced nitrate sampling; and, state adoption and USEPA approval of alternative monitoring. The article also provides a list of chronic chemical contaminants for which USEPA's alternative monitoring guidelines apply.
Air transfer efficiency of packed saturators used in DAF
Authors: Steinbach Sandra , Haarhoff Johannes
Published: February 2018

A mathematical model predicts how saturation pressure, hydraulic loading, and packing depth affect air transfer.

A rational model that predicts the air transfer efficiency in the packing layer of dissolved‐air flotation saturators is described. The model is defined in terms of absolute air concentrations, assumes the Lewis‐Whitman two‐film theory, and uses the Onda correlations to estimate the mass transfer coefficient. A comprehensive method is proposed for experimentally determining the overall air transfer efficiency of an operating saturator. A series of experiments was performed to partition the overall transfer efficiency into the contributions of top and bottom end effects, of free fall of the water before it reaches the packing, and of the packing itself. The laboratory data show a close agreement of the theoretical model with the measured performance. The model is used to demonstrate the effects of the most important saturator design parameters on the concentration of precipitable air.
Consumer confidence reports: challenge and opportunity
Authors: Berberich Charles
Published: February 2018

This requirement could inspire consumers to become utilities' partners.
Public affairs and the consumer landscape
Authors: Baron John M.
Published: February 2018

Water utilities need to get into their customers' heads to win their hearts and minds.

The water industry needs to develop a public information program that effectively publicizes its efforts to maintain a safe water supply. To do this, the industry needs to know the needs of its customers. Customers are motivated by concerns about health, good value for price, service, and the environment. As groups they may lobby for federal protection when the need is felt, and as individuals they may simply switch their allegiance to bottled water. Although they are overloaded with information, they remain interested in information relating to personal and public health. The industry needs to give customers information that meets their substantive and emotional needs. Asking them is the best way to determine what this information is.
Backwashing first‐stage sand–BAC filters
Authors: Niquette Patrick , Prévost Michèle , Maclean Robert G. , Thibault Daniel , Coallier Josée , Desjardins Raymond , Lafrance Pierre
Published: February 2018

Does it increase removal of biodegradable organic matter and ammonia?

The effect of filter backwash on the efficiency of first‐stage sand–biological activated carbon (BAC) filters was evaluated by comparing, in first‐stage sand–BAC filters, concentrations of ammonia, biodegradable dissolved organic carbon, aldehydes, and oxalate. These concentrations were measured before and after filter backwash. Filter position (first‐stage sand–BAC filters versus second‐stage BAC filters) was also studied to understand how flocs and particle accumulation influenced the efficiency of the first‐stage sand–BAC filter. A first‐stage sand–anthracite filter operated under similar hydraulic conditions and effluent turbidity acted as a reference. Filter backwash improved the efficiency of sand–BAC filters, especially in cold water sources. However, both filters produced similar water quality. First‐stage sand–anthracite filters did not adequately remove biodegradable organic matter and ammonia.
Communicating ICR Data on Cryptosporidium
Authors: Pontius Frederick W.
Published: February 2018

In July 1997, water utilities serving 100,000 or more people and using surface water began an 18‐month monitoring program for Cryptosporidium under the Information Collection Rule (ICR). This column reviews frequently asked questions concerning Cryptosporidium, the ICR, and available resources.
Energy management opportunities
Authors: Arora Harish , LeChevallier Mark W.
Published: February 2018

Annual savings attributable to management of electric demand were estimated at $3.4 million.

Energy costs are a major part of total operation and maintenance expenses for a water utility. An energy survey of the American Water System (AWS) water companies was conducted, and energy audits were conducted at three representative AWS water supply systems. The audits identified energy savings ranging from 10 to 32 percent compared with 1993 electrical costs. Cost‐effective energy conservation measures consisted of base loading the most efficient plant in a multiplant water system, implementing strategies to reduce demand charges, modifying pumps, and installing energy‐efficient lighting. Installation of variable‐frequency drives, standby generators, and energy‐efficient motors was recommended, but these devices were not cost‐effective. Energy savings and the corresponding implementation costs were extrapolated for the entire AWS on the basis of the surveys and results of the three audits. Identified energy conservation measures may save AWS $3.4 million annually (12.3 percent of existing energy costs) at an implementation cost of $6.1 million, with a payback period of 1.8 years.
Controlling DBPs with monocholoramine
Authors: Carlson Mark , Hardy Douglas
Published: February 2018

Operators can adjust pH, contact time, and chlorine dosage to promote disinfection while retarding formation of disinfection by‐products.

Balancing disinfection with control of disinfection by‐products (DBPs) requires an understanding of how common water quality variables such as chlorine dosage and contact time, temperature, pH, and total organic carbon (TOC) affect both processes. This article examines how these variables affect the concentrations of trihalomethanes (THMs) and haloacetic acids (HAAs) at the shorter contact times associated with the use of chloramines, rather than chlorine, for residual disinfection. Five case studies evaluated DBPs in five water sources of differing quality. The most important variables were TOC and chlorine contact time, but chlorine dosage, pH, and temperature also had an effect. Response to some variables was linear; response to others was nonlinear. In most water sources, THM concentrations were greater than HAA concentrations, but in some the reverse was true. DBP concentrations must be investigated under a range of conditions to determine the best way to use chlorine disinfection while minimizing concentrations of DBPs.
Working with the USDA to protect source water
Authors: Pedersen Dan W. , Luitweiler J. Preston , Torobin Marcia
Published: February 2018

Federal agricultural conservation programs can support the protection of drinking water sources.

In the past, water suppliers often relied on pristine sources of water from distant locales. With rapid population growth and the advent of intensive land use, however, water suppliers can no longer ignore the quality of their source water. The 1996 Safe Drinking Water Act amendments recognized this and authorized voluntary state‐supported incentive‐based petition programs, through which water suppliers can work with landowners and local organizations to protect source water. In addition to good‐faith efforts, financial incentives will be helpful in assuring an effective petition program. This article describes US Department of Agriculture incentive programs and how water suppliers can participate in them to augment their source water protection efforts.
Racing the Dinosaur
Authors: Hoffbuhr Jack W.
Published: February 2018

In his column, AWWA Executive Director Jack Hoffbuhr discusses the benefits of moving from an information‐based platform to a knowledge‐based environment. Flexibility in decision‐making, utilizing intellectual capital, and optimizing member resources are discussed as being important parts of a knowledge‐based environment.
Water conservation guidelines and the DWSRF
Authors: Beecher Janice A. , Flowers John E. , Matzke Charles S.
Published: February 2018

The SDWA's conservation guidelines provision reverberates throughout the DWSRF to help encourage conservation measures.

The Safe Drinking Water Act amendments of 1996 include a short and relatively little known provision concerning water conservation planning. The provision requires the US Environmental Protection Agency to publish guidelines for conservation planning by water systems. However, use of the guidelines in conjunction with the Drinking Water State Revolving Fund (DWSRF) or other programs is completely at the discretion of the states. For example, states can choose whether to require a conservation plan as part of a DWSRF application or award points to systems based on their completion of a plan. Although conservation planning is a voluntary provision, it has the potential to bring conservation into the mainstream of utility capital planning. Strategic use of conservation will help extend the value and life of water supply assets, while also expanding the beneficial investment of public funds through the DWSRF.
Conducting an Effective Meter Replacement Program
Authors: Olson Kevin
Published: February 2018

This article discusses the benefits of establishing a regular maintenance program for meters. Meter maintenance topics discussed are: testing; repairing or replacing; installation; communication; and, good record keeping.
M/DBP Rules: Their Effect on Small Systems
Authors: Post Dallas
Published: February 2018

This article discusses the regulation of microbiological contaminants and the effect these regulations will have on small water systems. The Microbial/Disinfection By‐products (M/DBP) cluster of rules are discussed in brief detail.
Safe Drinking Water January 1, 2000?
Authors: Pontius Frederick W.
Published: February 2018

This article discusses the year 2000 (Y2K) problem, which will affect computer systems worldwide on January 1, 2000. Topics covered include: in addition to computers, what exactly Y2K will affect; the state of preparedness of government and businesses; a description of the Y2K problem; and, the potential of Y2K to adversely affect all areas of a water utility.
UV light inactivation of Cryptosporidium oocysts
Authors: Clancy Jennifer L. , Hargy Thomas M. , Marshall Marilyn M. , Dyksen John E.
Published: February 2018

Animal infectivity studies demonstrate the efficacy of pulsed and advanced UV in inactivating Cryptosporidium oocysts.

Cryptosporidium parvum oocysts are highly resistant to conventional chlorine‐based disinfectants. The authors tested two innovative electrotechnologies that use ultraviolet (UV) light and found that both pulsed UV and advanced UV inactivated Cryptosporidium oocysts. The advanced UV system achieved >4‐log inactivation as determined in animal infectivity studies using the neonatal mouse model. With the pulsed UV system, oocyst inactivation was also noted in the process control (non‐UV‐exposed oocysts), suggesting that some oocyst inactivation may have occurred independently of UV exposure. Irrespective of this, both technologies appear to be effective and novel ways to treat drinking water and to provide an additional significant barrier that helps protect public health.
Rejection of MS‐2 virus by RO membranes
Authors: Adham Samer S. , Trussell R. Shane , Gagliardo Paul F. , Trussell R. Rhodes
Published: February 2018

If reverse osmosis is to be used for pathogen removal, quality control measures are necessary.

A bench‐scale study was conducted to evaluate MS‐2 virus rejection by reverse osmosis membranes. Viruses were recovered in permeate passing through some of the membrane structures. Thus, if reverse osmosis is to be used for pathogen removal, quality control measures on reverse osmosis membrane manufacturing are necessary to ensure that the required level of removals are achieved consistently.
USEPA Operator Certification Guidelines to Address Key Issues
Authors: Pontius Frederick W.
Published: February 2018

The Safe Drinking Water Act (SDWA) Amendments of 1996 direct the US Environmental Protection Agency (USEPA), in cooperation with the states, to publish guidelines that specify minimum standards for certification and recertification of operators of community and nontransient‐noncommunity public water systems. This article provides an in‐depth discussion of the USEPA draft guidelines, including the following topics: public health objectives; antibacksliding; baseline standards; operator qualifications; grandparenting; enforcement; certification renewal; resources needed to implement the program; recertification; stakeholder involvement; and, program review.
Maryland program builds operator skills
Authors: Barrett Joy M.
Published: February 2018

Innovative training center combines peer‐to‐peer instruction and technical assistance to hone trainees' know‐how.

For 15 years, the Maryland Center for Environmental Training (MCET) has been dedicated to training operators to deliver safe drinking water to local communities. The state of Maryland has been a national leader in the operator certification movement and has developed a rigorous program for building operators' technical skills and ensuring appropriate qualification of all operators working in the state. MCET's training and technical assistance programs are based on solid principles, including peer‐to‐peer training, building local expertise, and developing and distributing effective publications and training curricula.
ICR treatment studies
Authors: Allgeier Steven C. , Shukairy Hiba M. , Westrick James J.
Published: February 2018

Utilities are currently evaluating membranes and GAC for DBP precursor removal.

Under the treatment study requirement of the Information Collection Rule, 493 treatment plants were required to monitor total organic carbon (TOC) concentrations in their influent or finished water to determine whether studies evaluating granular activated carbon or membranes would be required. These TOC results were aggregated and analyzed by source water type, treatment type, disinfection practices, and geographic location. Seventy‐eight percent of these plants met the criteria to avoid the treatment study requirement. The remaining plants will be required to conduct new treatment studies, submit data from previous studies, or contribute funds to a cooperative research effort. Under the treatment study requirement, 62 granular activated carbon studies and 37 membranes studies will be conducted.
Using a membrane bioreactor to reclaim wastewater
Authors: Cicek Nazim , Franco Juan P. , Suidan Makram T. , Urbain Vincent
Published: February 2018

The membrane bioreactor is an emerging technology for the reclamation of municipal wastewater.

A pilot‐scale membrane bioreactor sufficiently purified simulated municipal wastewater for indirect recharge to groundwater or nonpotable uses. Throughout more than 500 days of steady‐state operation, total organic carbon concentrations of <1.1 mg/L and chemical oxygen demand of <3.5 mg/L were consistently achieved. No suspended solids were detected in the effluent during this period. The treated water was fully nitrified, resulting in low ammonia and organic nitrogen concentrations but high nitrate concentrations. Cyclic oxic–anoxic operation or an additional denitrification process would be necessary to meet potable water reuse standards. Phosphorus was fully used in the bioreactor for biological growth. Heterotrophic bacteria and MS‐2 viruses were completely retained by the membrane system, reducing the extent of final disinfection required.
Defining Public Water Systems
Authors: Pontius Frederick W.
Published: February 2018

This article discusses the definition of a public water system (PWS) as outlined by the Safe Drinking Water Act (SDWA) amendments of 1996. Before passage of the 1996 amendments, the SDWA defined a PWS as “a system for the provision to the public of piped water for human consumption if such system has at least 15 service connections or regularly serves at least 25 individuals.” The amendments revised the definition of a PWS in several areas, discussed here.
Distributing groundwater without a disinfectant residual
Authors: Hambsch Beate
Published: February 2018

In Germany, high‐quality groundwater may be distributed without a disinfectant residual.

Microbiological data on drinking water in a distribution system were compared before and after the treatment plant discontinued use of a chlorine residual. Bacteriological assessments of chlorinated groundwater consistently showed heterotrophic plate counts (HPCs) < 5 colony forming units (cfu)/mL, a count indicating that bacterial regrowth was very unlikely. Because chlorination that produced about 0.1 mg/L free chlorine residual led to taste and odor complaints, chlorination was discontinued, and water that contained no residual was distributed. Shortly after this change, samples with higher retention times produced HPCs as high as 60–80 cfu/mL. After four to six weeks these counts decreased to values again < 5 cfu/mL. This short‐term increase in HPCs, which has also been observed in other cases, is assumed to be due to a change in the biofilm.
Nitrate removal from contaminated groundwater
Authors: Liang Sun , Mann Mary Ann , Guter Gerald A. , Kim Philip H.‐S. , Hardan David L.
Published: February 2018

An innovative approach to design of an ion exchange plant used data from bench‐scale tests and computer models.

Data from bench‐scale tests were used in conjunction with computer model simulations to develop design criteria for an ion exchange treatment process for removing nitrate. This approach is a potentially economical means of predicting nitrate breakthrough profiles, which can be used to make preliminary assessments of nitrate operating capacity, as well as the effects of changing process parameters, on the operational efficiency of various ion exchange processes. In addition, the effects of volatile organic chemicals, strong oxidants such as chlorine, and arsenic adsorption on ion exchange resin degradation were assessed.
Complying With the Stage 1 D/DBP Rule
Authors: Pontius Frederick W. , Diamond William R.
Published: February 2018

On December 16, 1998, the US Environmental Protection Agency published the Stage 1 Disinfectants/Disinfection Byproducts (D/DBP) Rule and the Interim Enhanced Surface Water Treatment Rule. These rules are the result of extensive regulatory negotiations and a rulemaking process that formally began in 1992. This paper summarizes the Stage 1 D/DBP Rule. Topics covered include: compliance dates; requirements for residual free chlorine and chloramines; requirements for residual chlorine dioxide; requirements for chlorine DBPs; requirements for chlorite; best available technologies; routine monitoring requirements; requirements for bromate; reduced monitoring requirements; disinfection byproducts precursor removal requirements; total organic carbon removal; comparison of compliance forecasts for different size surface water systems; state primacy requirements; compliance choices; and, guidance manuals that are in preparation.
The past, present, and future SDWA
Authors: Pontius Frederick W.
Published: February 2018

In spite of an anxious beginning in 1974 and passage of draconian amendments in 1986, this act has evolved into a law that is workable today and holds promise for tomorrow.
Medium‐pressure UV for oocyst inactivation
Authors: Bukhari Zia , Hargy Thomas M. , Bolton James R. , Dussert Bertrand , Clancy Jennifer L.
Published: February 2018

In vivo studies indicate the infectivity of treated Cryptosporidium parvum oocysts more reliably than do in vitro assays.

Inactivation of Cryptosporidium parvum oocysts in finished drinking water by medium‐pressure ultraviolet (UV) light was investigated at bench scale using a collimated beam apparatus and at demonstration scale using a UV reactor. Oocyst viability was assessed in vitro (using 4',6‐diamidino‐2‐phenylindole with propidium iodide and maximized in vitro excystation) and in vivo (using neonatal mouse infectivity assays). In vivo bench‐scale studies showed > 4‐log inactivation at UV dosages as low as 41 mJ cm–2, although in vitro surrogate assays showed little or no inactivation at this or higher UV dosages. The in vitro assays, which indicate oocyst viability, grossly overestimated the UV dosages required to prevent oocyst infection in susceptible hosts. Results of demonstration studies, carried out under the Environmental Technology Verification program of the National Sanitation Foundation and the US Environmental Protection Agency, agreed with the bench‐scale results and showed that a UV dosage as low as 19 mJ cm–2 provided 3.9‐log inactivation of Cryptosporidium oocysts.
Financial help for utilities along the US–Mexico border
Authors: Brackbill Craig E.
Published: February 2018

Two interrelated international institutions offer much‐needed financial and technical assistance for communities along the US–Mexico border.

With the economic growth spurred by passage of the North American Free Trade Agreement, the significant environmental infrastructure needs along the US–Mexico border were expected to become more severe. In 1993, the United States and Mexico addressed this concern, signing a bilateral agreement that created two new interrelated international institutions. The Border Environment Cooperation Commission (BECC) reviews and certifies environmental infrastructure projects proposed within 100 km (62 mi) of the international border. The North American Development Bank (NADBank) helps develop financing for BECC‐certified projects and also serves as a lender. To date, 26 projects have been certified, with 14 projects receiving direct NADBank funding. The institutions work with both public and private project sponsors and financial participants. Small systems are eligible both for grants to assist with the application process and for programs to develop their internal capacities for construction and operation of new facilities.
Predicting full‐scale TOC removal
Authors: Tseng Tai , Edwards Marc
Published: February 2018

A Langmuir model providing good prediction of full‐scale TOC removal during enhanced coagulation may help utilities comply with forthcoming regulations.

A Langmuir model provides the best available prediction of full‐scale removal of total organic carbon (TOC) during enhanced coagulation. Because jar tests allow more transfer of carbon dioxide gas than treatment plants, the model can even correct certain errors arising during such tests. When the model was adapted to predicting TOC removal in two raw water sources mixed together in different proportions, standard error was only 0.15 mg/L for two years of jar‐test data at one utility. Case studies of 27 full‐scale utilities showed accurate prediction of TOC removal by coagulation (1) at a range of utilities using alum, ferric, or polyaluminum chloride coagulants; (2) over long time periods without a need for frequent recalibration; (3) with use of a predicted rather than measured coagulation pH; and (4) for two raw water sources mixed in various proportions.
Innovate or Hesitate?
Authors: Hoffbuhr Jack W.
Published: February 2018

In this column, Jack Hoffbuhr, Executive Director of the American Water Works Association, discusses the importance of innovation in today's business culture and describes several characteristics of innovative organizations.
Big Advantages in Membrane Filtration
Authors: Cleveland Christopher T.
Published: February 2018

Many small water systems are coping with an aging or nonexistent treatment facility, regulatory agencies requiring immediate action, and limited funding for drinking water projects. Solutions are often difficult to implement because of economic situations, staffing considerations, and other issues specific to small water systems. To provide safe drinking water to their customers while dealing with these challenges, many small water systems are turning to membrane filtration.
Selecting MF to satisfy regulations
Authors: Kelley William A. , Olson Roger A.
Published: February 2018

When Marquette, Mich., was faced with having to filter its cold, clean source water for the first time, microfiltration was the technology of choice.

The city of Marquette, Mich., operates a public water system that uses Lake Superior as its raw water source. Historically, only chlorination was provided so that the drinking water met state and federal drinking water standards. In 1989, the US Environmental Protection Agency promulgated the Surface Water Treatment Rule (SWTR), which requires filtration of all surface water sources unless the water supplier controls the watershed. This rule intensified efforts by the state's drinking water program to have the city install and operate a filtration system. The city was advised to construct a direct filtration plant but decided against it. An alternative suggestion for the city's cold, clean source water was microfiltration (MF). Results of a feasibility study and a pilot study were positive, and the city designed, constructed, and began operation of a 0.026 ˇ 106–m3/d (7‐mgd) MF plant. The plant, which has been on line for more than a year, has solved the SWTR regulatory concern and now provides the city with its drinking water.
NF performance at full and pilot scale
Authors: Mulford Luke A. , Taylor James S. , Nickerson David M. , Chen Shaio‐Shing
Published: February 2018

Nanofiltration pilot plants accurately represented full‐scale plant performance.

Productivity and water quality from the Roy W. Likens membrane facility in Palm Coast, Fla., were accurately simulated by three membrane pilot plants in a four‐month field investigation using various sizes of a film membrane manufactured by the same company and operated under the same conditions. All plants used the same source water, groundwater that is moderately hard (330 mg/L as CaCO3) and highly organic (11 mg/L non‐purgeable dissolved organic carbon, 336 trihalomethane formation potential [THMFP], 227 μg/L haloacetic acid formation potential [HAAFP]). All pilot units were built and operated according to standards in the Information Collection Rule (ICR). The average finished water quality for all membrane plants was 0.4 mg/L total organic carbon as C, 35 μg/L THMFP, and 28 HAAFP. For the full‐scale plant, membrane productivity decreased by 50 percent during five years. A second‐order resistance model more accurately described productivity over time than did a zero‐order direct mass transfer model, although both models produced statistically significant results. These results demonstrated that full‐scale plant performance could be accurately scaled up from single‐element or multistage pilot plants as specified in the ICR protocol.
Microfiltration goes Hollywood: the Los Angeles experience
Authors: Karimi Ali A. , Vickers James C. , Harasick Richard F.
Published: February 2018

Finished water turbidity and particle removal were independent of flux.

Faced with the need for additional treatment of its finished water stored in the Hollywood Reservoirs, the Los Angeles Department of Water and Power evaluated the efficacy of microfiltration (MF) to meet the requirements of the Surface Water Treatment Rule. This evaluation included a pilot test to assess the MF process and to define the design parameters (flux and frequency of chemical cleaning). Finished water turbidity and particle removal were independent of flux in the tested water. This finding allows the utility to operate the MF system at a flux as much as 50 percent higher than the 67‐gfd (114‐L/m2/h) flux currently allowed by California regulations. Membrane resistance was used to evaluate the system performance under variable operating conditions of temperature, flux, and pressure. A design flux of 67 gfd (114 L/m2/h) was projected to yield more than two months (i.e., 66 days) of filter run before chemical cleaning. A higher flux of 80–100 gfd (136–170 L/m2/h) was acceptable with more frequent chemical cleaning of the MF membranes.
Using limited data to assess future needs
Authors: Kleiner Yehuda , Rajani Balvant
Published: February 2018

A five‐step methodology was developed to help utilities with sketchy or scarce data on water main break history to budget for future pipe replacement.

Most major urban utilities are aware of the need to keep records of distribution system water mains. These records—which typically include data about water main break history, pipe material, pipe vintage, and soil type—are eventually used to allocate budgets to replace, rehabilitate, or repair aging distribution systems. Many utilities have incomplete or scarce water main data, which may make financial planning difficult. Thus, a methodology that facilitates the use of scarce, available data to assess future needs is warranted. Presented is a case study that followed five essential steps: (1) bundle data on water main breaks into homogeneous groups to predict future breaks for water utility regions for which data were insufficient, (2) establish breakage rate patterns for these groups to project future breakage rates, (3) use projected breakage rates to determine the economic life of water mains, (4) examine probabilistic scenarios of water main life, and (5) determine the investments required to replace water mains.
Source Water Protection for Small Systems
Authors: Trax John
Published: February 2018

Small Systems can strengthen public health protection by developing and implementing a source water protection program. An active program falls in the low to moderate price range and can save money over the long term by avoiding costly treatment modifications or additions needed to remove contaminants.
IESWTR Targets Poorly Performing Filtration Plants
Authors: Pontius Frederick W.
Published: February 2018

The Interim Enhanced Surface Water Treatment Rule establishes individual filter turbidity monitoring requirements for systems serving 10,000 or more people. If the turbidity in any filter exceeds 2.0 ntu for two consecutive months in two consecutive measurements taken 15 minutes apart, a comprehensive performance evaluation (CPE) is required. This requirement is intended to identify and correct poorly performing filtration plants. A CPE is the evaluation phase of the composite correction program (CCP). The CCP is a comprehensive, systematic process for identifying and correcting factors that limit the performance of a filtration plant. It was developed to improve plant performance by optimizing existing facilities, thus minimizing new capital construction.
Ion exchange softening: effects on metal concentrations
Authors: Sorg Thomas J. , Schock Michael R. , Lytle Darren A.
Published: February 2018

Leaching data from a two‐phase study indicate that ion exchange softening does not systematically increase metal concentrations.

A corrosion control pipe loop study was conducted to evaluate the effect of ion exchange water softening on metal leaching from household plumbing materials. The two water sources evaluated had different pH values and hardness levels. Results showed that removing hardness ions with a household water softener did not lead to a pattern of higher metal leaching from various home plumbing materials containing lead, copper, and zinc. Furthermore, the water softener did not have a detrimental effect on several significant water quality parameters that influence metallic solubility and the rate of corrosion, i.e., pH, total inorganic carbon, dissolved oxygen, chlorine, temperature, and orthophosphate.
Determining GAC bed life
Authors: Gillogly Thomas E.T. , Snoeyink Vernon L. , Vogel John C. , Wilson Claude M. , Royal Earl P.
Published: February 2018

Laboratory columns closely simulated the performance of a pilot plant for taste and odor control.

This study developed a way to rapidly and effectively evaluate the remaining life of a granular activated carbon (GAC) bed used to mitigate taste and odor episodes. The maximum attenuation of a 2‐methylisoborneol (MIB) episode, a representative taste and odor compound, can rapidly be determined using laboratory‐scale columns packed with partially spent GAC taken from full‐scale operating adsorbers. These laboratory‐scale columns closely simulated the performance of pilot‐scale columns. The percent of a transient MIB load removed by GAC did not depend on the influent MIB concentration but did depend on the amount of natural organic matter adsorbed on the GAC surface. This approach can be used to determine GAC's potential percentage removal of taste‐ and odor‐causing compounds as a function of GAC service time. It allows GAC to be tested to estimate its readiness for summer taste and odor episodes. Adsorption alone in GAC adsorbers that used < 10 min of empty bed contact time was insufficient to fully protect against typical MIB episodes.
Password‐Protected
Authors: Hoffbuhr Jack W.
Published: February 2018

In this column, AWWA Executive Director Jack Hoffbuhr describes his experiences with new technology and suggests that we be issued passwords to operate the new devices, thus remaining in control of our environment.
ICR Crypto Data: Worthwhile or Worthless?
Authors: Pontius Frederick W. , Clancy Jennifer L.
Published: February 2018

The Information Collection Rule (ICR) was designed to provide data to be used in the development of Stage 2 of the Disinfectants/Disinfection Byproducts Rule for the regulation of microbial contaminants and disinfection by‐products. The ICR included monitoring for Cryptosporidium using procedures defined by the US Environmental Protection Agency (USEPA) and an analytical method referred to as the ICR method.1 Monitoring and reporting under the ICR are complete. USEPA has begun to release validated ICR data to stakeholders and to the public, including data for Cryptosporidium.
Assessing ozone disinfection with nonbiological surrogates
Authors: Mariñas Benito J. , Rennecker Jason L. , Teefy Susan , Rice Eugene W.
Published: February 2018

Fluorescent‐dyed polystyrene microspheres can be used to assess disinfection efficiency.

The authors investigated the use of fluorescent‐dyed polystyrene microspheres to assess drinking water disinfection efficiency in full‐scale ozone contactors. A demonstration was conducted with one of two parallel full‐scale ozone bubble‐diffuser contactors at the Alameda County Water District Water Treatment Plant in Fremont, Calif. Microsphere suspensions were analyzed by flow cytometry to determine changes in fluorescence distribution. Selection of threshold fluorescence intensities allowed the determination of microsphere “survival” ratios that were correlated with Cryptosporidium parvum inactivation curves. Compared with the concentration times contact time (C X T) concept, use of the surrogate indicators offered a potentially simpler and more accurate approach for assessing and optimizing ozone disinfection efficiency achieved in full‐scale contactors and for demonstrating compliance with disinfection requirements.
Committee Report: Emerging pathogens—viruses, protozoa, and algal toxins
Authors:   AWWA Research Division Microbiological Contaminants Research Committee
Published: February 2018

Water utility managers will need to know important issues about microbes of concern in drinking water.

The American Water Works Association Research Division Microbial Contaminant Committee reviewed three viral and three protozoan microorganisms and one set of bacterial toxins of greatest concern to the water industry: enterovirus, calicivirus and Norwalk virus, and hepatitis; Cyclospora cayetanensis, microsporidia, and Toxoplasma gondii; and cyanobacterial toxins. To help the water quality specialist, this report describes the virus, protozoan, or toxin; reviews its health effects; summarizes information on its occurrence, waterborne outbreaks, and water treatment; discusses analytical procedures; and outlines needed research.
Microbiological quality before and after nanofiltration
Authors: Laurent Patrick , Servais Pierre , Gatel Dominique , Randon Guy , Bonne Pascal , Cavard Jacques
Published: February 2018

A long‐term study identifies the benefits accrued when a distribution system fed with biologically treated water switches to a nanofiltered supply.

The authors investigated microbiological behavior of a distribution system supplied initially with biologically treated water and then with nanofiltered water. Their purpose was to identify and evaluate the changes in microbiological water quality attributable to modifications in water treatment at the plant. During the course of the study, all data from various indicators of microbiological quality (i.e., heterotrophic plate counts, coliform enumeration, total direct counts, and fixed bacterial biomass) showed similar trends. Results indicated that the use of nanofiltration allows utilities to reduce chlorination of treated water and at least maintain or increase the microbiological quality of distributed water for areas with high residence times.
Using ion chromatography to detect perchlorate
Authors: Okamoto Howard S. , Rishi Dharmendra K. , Steeber William R. , Baumann Frank J. , Perera S. Kusum
Published: February 2018

Ion chromatography with suppressed conductivity was used to develop the California Department of Health Services trace concentration method for perchlorate analysis.

This article describes an ion chromatography method to analyze trace concentrations of perchlorate in drinking water. Perchlorate was separated from anions commonly found in groundwater and surface water by elution through an AS5 anion exchange column with 120 mmol/L sodium hydroxide + 2 mmol/L ρ‐cyanophenol. Analytes were measured by conductometric detection using signals enhanced by chemical suppression of the conductance from the eluent. A 740‐μL sample injection provided the sample mass necessary to achieve a perchlorate method detection limit of ≤ 1 μg/L and a working range of 2.5–100 μg/L, without sample preconcentration. Interference studies showed that 5.0 μg/L of perchlorate could be measured in the presence of 1,000 mg/L of bicarbonate, chloride, or sulfate. The method was successfully used to survey drinking water wells in California considered vulnerable to perchlorate contamination.
Combined arsenic and nitrate removal by ion exchange
Authors: Ghurye Ganesh L. , Clifford Dennis A. , Tripp Anthony R.
Published: February 2018

If an MCL < 5 μg/L is adopted for arsenic, then many suppliers will need to treat water specifically to remove it.

On‐site ion exchange studies investigated the combined removal of arsenic (V) [As(V)] and nitrate from drinking water in McFarland and Hanford, Calif., and Albuquerque, N.M. Whereas previous ion exchange workers had studied removal of high concentrations of As (> 50 μg/L As) without nitrate present, these studies focused on removing 10–15 μg/L As to achieve a product water with < 2 μg/L As while also maintaining nitrate below its maximum contaminant level. Results of 1‐in.‐ (25‐mm‐) column experiments showed that conventional sulfate‐selective resins were better than special nitrate‐selective resins for combined As(V) and nitrate removal. The conventional resins yielded longer run lengths and leaked less As and nitrate into the product water. Decreasing empty bed contact time from 3.0 to 1.5 min did not greatly alter As leakage into the product water. Particulate iron in the ion exchange feed increased As leakage in the product water. Two commercially available computer programs were reasonably accurate in predicting both As and nitrate run lengths for various influent nitrate and sulfate concentrations. Generally, predicted As and nitrate run lengths were within ±35 percent of those observed experimentally.
Generation Gap
Authors: Hoffbuhr Jack W.
Published: February 2018

In his monthly column, AWWA Executive Director Jack Hoffbuhr discusses the aging baby boom generation and the effect on the workforce they continue to have, even as they are nearing retirement age.
Y2K: Where Are We Now?
Authors: Pontius Frederick W. , DeBoer Jon G.
Published: February 2018

This article discusses the Year 2000 Readiness and Responsibility Act of 1999, known as the Y2K Act. The primary purpose of this act was to establish special rules for commercial litigation related to Y2K computer failures. Noncompliance resulting from a Y2K incident may last only 15 days unless an extension is granted. To meet the government's need for information on the Y2K date rollover, an information coordination center will serve as the federal government's central point for coordinating a wide range of information on system operations and events related to the Y2K transition.
Conscientious particle counting
Authors: Van Gelder Annika M. , Chowdhury Zaid K. , Lawler Desmond F.
Published: February 2018

The water industry needs to develop concentration standards that will enable it to assess the accuracy of particle counts taken by different instruments.

Research was undertaken to test whether different particle counters yield the same particle count and size distribution information, to assess the possibility of using particle concentration standards from other applications in the water industry, and to develop and test a concentration standard for use in the water industry. Five particle counters were used, including duplicates of each of two manufacturers' light‐obscuration instruments (commonly used in the water industry) and one electrical sensing zone (ESZ) instrument. On all types of samples (latex spheres, a commercially available fine test dust used as a standard in other industries, and water treatment plant samples), the light‐obscuration instruments consistently measured far fewer particles in the smallest sizes (2–5 μm) than the ESZ instrument, and evidence is presented that suggests the ESZ instrument is more correct. Recommendations for standards to use with light‐obscuration instruments include using a multimodal count standard using latex spheres of two sizes, with those sizes being in the middle of standardized size ranges; using separate sizing standards at the boundaries of the size ranges; and avoiding any use of particle counters for regulatory purposes at this time.