bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using granular media amendments to enhance NOM removal
Authors: Collins M. Robin , Eighmy T. Taylor , Jr. James M. Fenstermacher , Spanos Stergios K. 
Published: February 2018

Granular media amendments to slow sand filtration show promise in improving organic precursor removal.Filters amended with anionic resin and granular activated carbon (GAC) achieved significantly higher (>75 percent) removals of organic carbon and trihalomethane formation potential during an 89‐day filter run than any other filter media combination studied. There was no significant difference in removal rate with GAC used as a surface or sublayer amendment. Treatment efficiencies of the aluminum oxide–, anthracite‐, and clinoptilolite‐amended slow rate filters could not be clearly distinguished from conventional slow sand filters with precursor removals <25 percent. Organic precursor removal by slow rate filters was considered a function of both the microbiological maturity and adsorptive capacity of the schmutzdecke and filter bed. Maintenance of elevated removals by resin‐ or GAC‐amended slow sand filters will eventually require the use of deeper amendment layers or frequent replacement or
Characterizing filter media mineral coatings
Authors: Merkle Peter B. , Knocke William , Gallagher Daniel , Junta‐Rosso Jodi , Solberg Todd 
Published: February 2018

Characterizing filter media mineral coatings using analytical techniques from geological science helps unlock fundamental filtration phenomena.Fundamental analytical techniques from the geological sciences were employed to characterize the surface coatings found on anthracite and sand filter media from a variety of full‐scale water treatment facilities. Attempts were made to relate the presence of various chemical surface coatings to the process chemistry used at the facility, the presence of various chemical species (e.g., manganese) in the raw water, or both. The authors also considered the role that such chemical oxide surfaces may play in the overall performance of filtration systems.
Calibrating hydraulic network models
Authors: Ormsbee Lindell E. , Lingireddy Srinivasa 
Published: February 2018

To a novice, careful calibration of a hydraulic network model may be as daunting a task as climbing Mt. Everest.Although calibration should always be included in any hydraulic analysis, it is often neglected or done haphazardly. As a result, inappropriate data may be used or data errors may be overlooked, so the resulting hydraulic model is of limited value. The novice may see calibrating a hydraulic network model as a task as daunting as climbing Mt. Everest. This article presents a seven‐step method for use in calibrating a hydraulic network model. The last and most difficult step is microlevel calibration, which involves the adjustment of demand loadings and pipe roughnesses until computed and observed field pressures or flow rates are within reasonable agreement for various levels and extremes of demand, pumping, and storage. Various explicit calibration algorithms have reduced the need for trial‐and‐error procedures and have improved the reliability of the resulting calibration. There remains little justification for failing to develop good calibrated network models prior to network analysis.
Biological mechanisms in slow sand filters
Authors: Weber‐Shirk Monroe L. , Dick Richard I. 
Published: February 2018

Bench‐scale investigations of particle removal mechanisms in slow sand filters identify bacterivory as the only significant biologically mediated particle removal mechanism.Particle and E. coli removal mechanisms in slow sand filters were investigated at bench scale. Sodium azide (an inhibitor of oxidative phosphorylation) caused appreciable reduction in particle and E. coli removal; this indicated biological removal mechanisms were significant. Bacterivory was identified as the biological mechanism principally responsible for bacteria removal. There was no evidence of significant particle removal by attachment to biofilms.
Competition strategies for a public utility
Authors: Pontek Robert , Wehmeyer Mark 
Published: February 2018

In Martin County, Fla., private sector involvement was part of the solution that kept a public water utility in charge.Throughout the water and wastewater industry, public utilities face heightened competition from private contract operations and maintenance firms. Public utilities can successfully compete with private sector companies if—and only if—they are willing to embrace modern organizational concepts, employ technology as appropriate, and solicit and receive support from their employees. The governmental organization must also be willing to adapt and provide more responsive support (i.e., purchasing, fleet maintenance, and personnel).
Public involvement helps supply project succeed
Authors: Plank R. David , Rogers Roddy , Shorney Frank L. , Novak Donald J. , Zion Robert R. 
Published: February 2018

A Missouri utility invited public participation in a water supply planning project, and voters approved the bond issue to finance the project by a margin of 89 percent.Completing a major water supply project in today's tangle of environmental, regulatory, legal, political, and property rights issues may cost utilities lots of time and money—and do little to boost their public image. City Utilities (CU) of Springfield, Mo., faced these challenges head on while investigating and implementing plans to develop a new 30‐mgd (0.114 X 106‐m3/d) water supply. The utility involved community leaders, water consumers, landowners, governing agencies, regulators, and the news media from planning through design to construction and startup. These efforts helped lead to a high‐quality project completed under budget and ahead of schedule. Such success is attributed largely to a thorough public involvement campaign resulting in wide public acceptance. Voters approved a $57.5 million bond issue to finance the project by 89 to 11 percent.
Communication strategies for pipeline construction
Authors: Price Neal , Melton James R. , Stift Michael T. 
Published: February 2018

Effective communication and scheduling turned a pipeline construction project on a golf course into a win–win situation for the country club and the San Diego County Water Authority.The San Diego County Water Authority has nearly completed a 3.4‐mi (5.5‐km), 72‐in.‐ (1,830‐mm‐) diameter potable water pipeline and associated facilities in northwest San Diego County, Calif. The north county distribution pipeline project includes the pipeline, three flow‐control and metering facilities, a 1‐mil‐gal (0.004 × 106–m3) prestressed‐concrete regulating structure, and a chlorine contact tank. The pipeline parallels and crosses two 24‐in.‐ (610‐mm‐) diameter potable lines that serve 85 percent of the daily water supply to Oceanside, Calif. Construction began in March 1995 and concluded late in 1996.
Financial indicators measure fiscal health
Authors: Jordan Jeffrey L. , Carlson Christopher N. , Wilson James R. 
Published: February 2018

Using financial ratios, the authors establish indicators that can be used to monitor a utility's financial performance.As part of AWWA's QualServe program, utilities will require yardsticks that include system financial performance indicators. The purpose of this article is to provide a set of financial indicators to aid utility managers in their efforts to measure financial health and performance. Provided are readily available tools to track system financial performance to help assure the future viability of the system and the provision of water to the public.
Understanding protozoa in your watershed
Authors: Crockett Christopher S. , Haas Charles N. 
Published: February 2018

A watershed must be understood at a fine level of detail until more is known about the sources, fate, and transport of protozoa.To fully protect and control its watershed, a utility must own its reservoir systems and land reserves. Few utilities are in this position. The many others with limited or no watershed protection capabilities must identify all potential sources of contamination. A systematic approach enables identification of sources of protozoa and conditions that could lead to treatment challenges, and it enables utility personnel to make decisions more confidently about protection of source waters and consumers.
Distributing reclaimed water through dual systems
Authors: Okun Daniel A. 
Published: February 2018

Dual distribution systems for nonpotable water reuse can help preserve high‐quality water supplies and reduce treatment costs.Growing urbanization has put a heavy demand on limited sources of water for public community water supply systems. A proven conservation measure to help meet increasing demand is the reclamation of wastewater for nonpotable purposes. Reclaimed water can be used for landscape and recreational grounds irrigation, industrial processes, cooling towers, air‐conditioning, stack gas scrubbing, toilet flushing, construction, firefighting, and environmental enhancement such as maintaining urban stream flows and wetlands. Urban reuse requires dual distribution systems that use one system for potable water and another for reclaimed water. Dual systems are particularly appropriate for urban developments now being planned, but they can prove cost‐effective even for systems that must be retrofitted. The economies arise from savings in the acquisition and development of new water sources and facilities and in wastewater treatment and disposal. Because the public health risk from nonpotable reuse is minimal, public acceptance is high and even enthusiastic. Nonpotable urban reuse is an option worth consideration by municipalities seeking additional water supply to meet future needs.
UV disinfection of small ground water supplies
Authors: Parrotta Marc J. , Bekdash Faysal 
Published: February 2018

Ultraviolet light treatment is safe, effective, and cost‐competitive for small systems that do not require residual disinfection.The US Environmental Protection Agency has critically analyzed disinfection technologies available to small public water systems. Future groundwater disinfection requirements are expected to affect many public groundwater supplies, including a large number of very small noncommunity systems. Because small water systems generally have fewer technical and financial resources to cope with new requirements, they will need the simplest and lowest‐cost techniques that enable them to comply with new drinking water standards. To address this issue, the agency studied ultraviolet light technology. This article summarizes availability, efficacy, operability, and costs of this technology as an option for small systems.
Effect of chlorine on PAC's ability to adsorb MIB
Authors: Gillogly Thomas E.T. , Snoeyink Vernon L. , Holthouse Andrea , Wilson Claude M. , Royal Earl P. 
Published: February 2018

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

In a laboratory study, metals leached from cement–mortar linings at levels that suggest water suppliers should be selective when choosing cement for lining pipes.A laboratory study was conducted to test the leachability of regulated metals from cement–mortar linings inside drinking water pipes. Faucet water of known quality was introduced in the test pipes and maintained in static, pressurized conditions for extended periods of time. Water samples were frequently drawn from the pipes and tested for metals and other water quality parameters during the test periods. Significant amounts of barium, cadmium, and chromium leached out from the cement–mortar linings in two of the three test pipes during the first 14 days of water stagnation. Barium and chromium continued to leach out at detectable levels as the pipes were subsequently refilled. The authors recommend that the water industry be selective in choosing cement for lining pipes.
Analyzing HAAs and ketoacids without diazomethane
Authors: Xie Yuefeng , Reckhow David A. , Springborg Denise C. 
Published: February 2018

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

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

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

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

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

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

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

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

Spreadsheets can automate any chemical equilibrium calculation that can be performed by hand.Lotus 1‐2‐3® worksheets for calculating the calcite saturation index (SI) and calcium carbonate precipitation potential of a water sample are described. A simplified worksheet illustrates the principles of the method, and a more complex worksheet suitable for modeling most potable water sources is briefly described. Both worksheets include ion pairing and adjustments of equilibrium constants for temperature and ionic strength. For several test cases with a wide range of temperature, alkalinity, pH, and calcium concentration, the worksheet SI values differed <1 percent from those computed by WATEQX. For water quality modeling, spreadsheets have several advantages compared with large equilibrium codes: flexible input and output, ease of maintaining the thermodynamic database, and relatively small memory and mass‐storage requirements. Modeling of archived chemical data is possible through the combination of database management and computational capabilities of many commercially available programs. The worksheets can be obtained from the authors.
Pilot‐plant training for high turbidity
Authors: Norton Russell , Auckly Chet , Raymond Will , Benedict Scott , Goodwill John 
Published: February 2018

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