bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removing Giardia and Cryptosporidium by conventional treatment and direct filtration
Authors: Nieminski Eva C. , Ongerth Jerry E. 
Published: February 2018

Data on Giardia cyst and Cryptosporidium oocyst removal correlated with the removal of particles of each cyst's size range, regardless of the treatment mode.A two‐year evaluation of Giardia cyst and Cryptosporidium oocyst removal was conducted at a full‐scale 900‐gpm water treatment plant and at a 0.5‐gpm pilot plant, both operated under conventional treatment and direct filtration regimes. Raw water quality (turbidity and algal content), as well as treatment effectiveness in removing turbidity, controlled the removal of seeded cysts more than the mode of treatment. A high correlation was found between cyst removal rates and removal of the respective size particles; poorer correlation was found between the cysts and turbidity removal, whereas no correlation was established between the removals of cysts and heterotrophic bacteria.
Economics of Small Systems
Authors: Rommelmann David W. 
Published: February 2018

Enhanced cooperation among agencies will be an advantage to small systems.This discussion of economic issues that affect small systems was held in Anaheim, Calif., June 20, 1995. Moderator was David W. Rommelmann, regional vice‐president at Boyle Engineering Corp., 8430 University Executive Dr. Park, Suite 601, Charlotte, NC 28262. Other participants were Peter Cook, deputy director of the Office of Ground Water and Drinking Water, US Environmental Protection Agency, 301 M St. S.W., Washington, DC 20460; John Cromwell, manager of water supply, Apogee Research Inc., 4350 East West Hwy., Suite 600, Bethesda, MD 20814; Dan L. Fraser, water and wastewater consultant, 501 Tamarack, Helena, MT 59601; Joel McManus, economic development specialist for the National Rural Electric Cooperative Association, 1800 Massachusetts Ave. N.W., Washington, DC 20036; James D. Schwartz, acting assistant administrator of water and waste, US Department of Agriculture Rural Utilities Service, 14th and Independence Ave. S.W., Washington, DC 20250; and Elizabeth Ytell, senior associate, Northbridge Environmental Management Consultants, 601 University Ave., Suite 123, Sacramento, CA 95825. (At the time of this discussion, she was director of environmental services for the Rural Community Assistance Corporation in Sacramento.)
Pilot‐plant studies: from planning to project report
Authors: Logsdon Gary S. , LaBonde Shawn , Curley Donald , Kohne Roger 
Published: February 2018

Careful planning can increase the likelihood that a pilot study will lead to reliable conclusions and recommendations.Pilot‐plant studies are often considered appropriate or necessary for effective planning, design, and operation of water treatment facilities. By carefully planning pilot‐plant investigations before they are undertaken and by diligently conducting the study, water utility staff and engineers can maximize the return on the resources invested in pilot‐plant programs. This article contains ideas and concepts on pilot‐plant testing that have been developed through two decades of work with pilot plants.
Alkalinity, pH, and copper corrosion by‐product release
Authors: Edwards Marc , Schock Michael R. , Meyer Travis E. 
Published: February 2018

The conventional Langelier index or Larson's ratio approach to controlling copper corrosion by‐product release is demonstrably inaccurate.Contrary to expectations, higher bicarbonate concentrations exacerbate copper corrosion rates and by‐product release. In fact, as illustrated by monitoring experiences of large utilities and by laboratory data, the concentration of copper corrosion by‐products in drinking water increases linearly with bicarbonate concentration at constant pH. This relationship implicates cupric hydroxide solubility in control of copper release from relatively new (less than a few years old) copper plumbing. Decision‐making guidance from a traditional Larson's ratio or Langelier index approach can aggravate copper corrosion problems; consequently, their use should be discontinued for copper corrosion mitigation. In contrast, aeration–CO2 stripping is a particularly attractive strategy because benefits from higher pH are realized without adverse effects from higher alkalinity.
Water quality and disinfection kinetics
Authors: Haas Charles N. , Joffe Josh , Anmangandla Uma , Jacangelo Joseph G. , Heath Mark 
Published: February 2018

Water qulity significantly affects predictions of microbial inactivation.The contact‐time tables of the US Environmental Protection Agency are based on survival data obtained in buffered demand‐free water. However, disinfection data from experiments conducted at Drexel University showed that the choice of source water influences the degree of inactivation. Sophisticated disinfection kinetic models and statistical tests are used to analyze the sources of these discrepancies. This article demonstrates that the quality of a particular source water is a significant factor in predicting disinfection effectiveness.
Public–Private Partnerships
Authors: Featherstone Jeffrey P. 
Published: February 2018

The arrangement may benefit both parties, but it should not be entered into lightly.This discussion about public–private partnerships was held June 21, 1995, in Anaheim, Calif. Moderator was Jeffrey P. Featherstone, policy analyst for the Delaware River Basin Commission, 25 State Police Dr., West Trenton, NJ 08628. Other participants were Janice Beecher, senior research scientist and director of regulatory studies at the Center for Urban Policy and the Environment, Indiana University, 342 N. Senate Ave., Indianapolis, IN 46204‐1708; Peter Huhn, wastewater consultant, 41304 Bravos Court, Temecula, CA 92591, formerly of Operations Management International; Michael J. Leonard, chief executive officer of Atlanta–Fulton County Water Resources Commission and national expert for water and wastewater infrastructures, US Environmental Protection Agency, 345 Courtland St., Atlanta, GA 30365; Pio Lombardo, vice‐president of client services for Wheelabrator, Liberty Lane, Hampton, NH 03842; Kenneth J. McCaughtry, member of board of directors of Beaver Falls Municipal Authority, 8th Ave., Beaver Falls, PA 15010; and George Raftelis, president of Raftelis Environmental Consulting Group, 6100 Fairview Dr., Charlotte, NC 28210.
Coagulation: its effect on organic matter
Authors: Dennett Keith E. , Amirtharajah A. , Moran Thomas F. , Gould Joseph P. 
Published: February 2018

Mass spectra obtained using fast atom bombardment provided qualitative information about coagulation's effectiveness under various treatment conditions.Removal of natural aquatic dissolved organic matter (DOM) by conventional coagulation using ferric chloride was investigated. Reverse osmosis was used to isolate DOM from the Suwannee River in southern Georgia and from Lake Allatoona in northwestern Georgia. The two most significant differences between the source waters are pH and organic carbon concentration. Extensive jar‐testing identified regions of removal based on initial concentration of DOM, coagulant dosage, and pH conditions. Fast atom bombardment mass spectrometry was used to characterize the molecular‐weight distributions of DOM before and after coagulation. Trends in the shape of the mass spectra correlated well with data for DOM removal and suggested that the mechanism for DOM removal varies with the pH and coagulant dosage. At higher pH conditions and lower coagulant dosages, masses up to 1,000 daltons (D) were detected in the mass spectra after coagulation. At lower pH conditions and higher coagulant dosages, no masses above 750 D appeared in the mass spectra.
AWWA taste and odor survey
Authors: Suffet I.H. (Mel) , Corado Ana , Chou David , McGuire Michael J. , Butterworth Steve 
Published: February 2018

A 1989 survey provides insights on how utilities perceive taste and odor problems in their water supplies, what treatment processes they use, and which processes they rated effective.A taste and odor questionnaire was sent to 826 water utilities. A total of 377 usable responses were received from across the United States and Alberta, Canada. Sixteen percent of the utilities considered their taste and odor problems to be serious, and 43 percent had experienced a taste and odor event lasting longer than one week. The major odor problems reported by the utilities were characterized as chlorine, earthy, fishy, and medicinal; major taste problems were reported as sour, metallic, and chlorine. There were differences between the taste and odor problems encountered by utilities treating groundwater and those treating surface water. Most utilities attributed taste and odor problems to the distribution system. In addition, groundwater plants identified the disinfectant used and mineral residuals as other sources of taste and odor problems. Surface water systems blamed plankton and decaying vegetation in the influent water, the disinfectant used, and conditions at reservoirs.
Characteristics and costs of MF and UF plants
Authors: Adham Samer S. , Jacangelo Joseph G. , Laîné Jean‐Michel 
Published: February 2018

Date from this Questionnaire indicate that larger‐capacity MF and UF plants are becoming technologically and economically feasible.A questionnaire was sent to membrane filtration plants worldwide regarding their capacities, operation, water quality, and costs. The total plant capacity of all utilities responding was 49 mgd (185,500 m3/d). About 90 percent of the existing plants have design capacity < 1 mgd (< 3,800 m3/d). The largest plant is a 15‐mgd (57,000‐m3/d) ultrafiltration plant currently being commissioned in France. Source waters for the plants included both groundwater (35 percent) and surface water (65 percent) and were not necessarily limited to high‐quality waters. Although influent total coliform concentrations ranged from 1 to >1,000/100 mL, none of the plants reported the presence of coliforms in their permeate. The current treatment unit cost for membrane filtration ranges from <$0.50/1,000 gal (<$0.13/m3) for plant capacities >5 mgd (>19,000 m3/d) to as high as $2.50/1,000 gal ($0.66/m3) for plant capacities of 0.01 mgd (38 m3/d). Capital and operation and maintenance costs of membrane filtration are expected to continue to decline.
GAC: pore structure versus dye adsorption
Authors: Krupa Nicholas E. , Cannon Fred S. 
Published: February 2018

Field‐spent carbons that had been catalytically reactivated were analyzed for adsorption capacity in relation to pore structure.Laboratory tests compared several virgin and reactivated granular activated carbons (GACs) with regard to pore‐size distributions versus their water‐phase adsorption capacity for several adsorbates. Pore‐size characterizations employed N2 adsorption isotherms, as interpreted by the density functional theory (DFT) model. These were compared with previous results that employed the Barrett, Joyner, and Halenda model, as adapted by the authors. The newly developed DFT model offered better correlations to water‐phase adsorption behavior, although it also exhibited an apparent anomaly in the 8–12‐Å pore‐width range. For the coal‐based GACs used in this study, the pore sizes that provided the greatest adsorption capacity correlated well with the dimensions of the adsorbates; small‐compound adsorption correlated most strongly with micropore volume, and larger dye adsorption correlated most strongly with mesopore plus large micropore volume. Coefficients of determination (r2) exceeded 0.95 when the appropriate range of DFT pore‐volume distribution was compared with dye or p‐nitrophenol adsorption capacity.
Influence of NOM on copper corrosion
Authors: Korshin Gregory V. , Perry Samuel A.L. , Ferguson John F. 
Published: February 2018

Experimental data suggest that NOM promotes the formation of pits in a certain narrow range of concentrations and suppresses this type of corrosion at higher dosages.Natural organic matter (NOM) profoundly affected the corrosion of copper in a moderately alkaline synthetic water. It decreased the rate of corrosion, increased the rate of copper leaching, and dispersed crystalline inorganic corrosion products. The interaction of NOM with corrosion products was modeled using separate phases of malachite and cuprous oxide. The authors concluded that NOM promotes the formation of pits in a certain narrow range of concentrations (0.1–0.2 mg/L in laboratory tests) and suppresses this type of corrosion at higher dosages. At low DOC concentrations, the main interaction between NOM and the surfaces of corroding metal and corrosion products is adsorption. The influence of NOM on corrosion of metals in real distribution systems must be studied in relation to long periods of surface aging, flow rate, concentration and type of oxidants, pH, and alkalinity.
Water quality deterioration from corrosion of cement–mortar linings
Authors: Douglas Bruce D. , Merrill Douglas T. , Catlin Joel O. 
Published: February 2018

Under extended low‐flow conditions, water can leach cementitious materials from cement–mortar lining, and significant increases in pH can result.Corrosion of cement–mortar lining—i.e., the leaching of lime from the cement matrix—can impair water quality by increasing pH, calcium, and alkalinity. Field tests at two utility sites evaluated the effects of water flow, lining method, seal coating, water quality, and cement–mortar composition. Water that remained stagnant in newly lined pipe sections for a relatively long time (one week) exhibited significant water quality effects—e.g., pH increases up to 12. Asphaltic seal coats significantly reduced cement–mortar corrosion in both tests. At one site, corrosion increased when the mortar contained Type II cement, a water‐reducing admixture, pozzolanic material, or a high proportion of sand. At the other site, none of these parameters significantly affected results. Design and operating measures to minimize stagnation can reduce corrosion effects.
Committee report: water accountability
Authors: Committee AWWA Leak Detection and Water Accountability 
Published: February 2018

Advances in technologies and expertise should make it possible to reduce lost and unaccounted‐for water to less than 10 percent.Often, decision‐makers in the water supply field are satisfied when they can account for 85 percent of the water they produce. Recognizing the problem of lost or nonrevenue‐producing water and desiring to find solutions for member utilities, AWWA's Distribution and Plant Operations Division asked the Leak Detection and Water Accountability Committee to write this report, which recommends that because of increasing demand and higher operational costs, the goal for lost or nonrevenue‐producing water should be less than 10 percent. The report also proposes that certain guidelines should be followed when the goal of 10 percent is not met.
Waterborne disease surveillance
Authors: Frost Floyd J. , Craun Gunther F. , Calderon Rebecca L. 
Published: February 2018

Because current reporting systems have drawbacks, drinking water professionals should collaborate with the public health community to enhance approaches to waterborne disease surveillance.One option for obtaining information about the occurrence and causes of epidemic and endemic waterborne disease is to improve disease surveillance systems now in place in most state and local health departments. In addition, the authors recommend additional ways of improving disease surveillance and investigating endemic waterborne disease. Health care reform may reduce the effectiveness of the current system of laboratory‐based disease reporting, but opportunities for enhanced disease surveillance may also emerge from these reforms. In addition, new laboratory technologies may make routine surveillance of enteric pathogen infections, rather than disease from these pathogens, increasingly feasible. The interests and information needs of the drinking water industry and its customers can best be assured by its informed participation in the debate over the design and goals of new disease surveillance programs.
Backflow protection and residential fire sprinklers
Authors: Hart Frederick L. , Nardini Christine , Till Robert , Bisson Daniel 
Published: February 2018

Is backflow prevention necessary to prevent stagnant water in residential fire sprinklers from contaminating municipal supplies?The current risk of death or injury from fire is 11.1 times higher than the current risk of waterborne illness. An analysis was conducted to determine the possible overall public health effect if residential fire sprinklers are connected to municipal water supply systems. Risk‐versus‐benefit calculations associated with the installation of residential fire sprinkler systems with and without various levels of backflow prevention are presented. The degree of risk for waterborne illness would remain essentially unchanged from current conditions if residential sprinkler systems were installed with a simple check valve device, and the relative degree of risk from fire would be reduced from 11.1 to 5.8.
Sizing residential service lines
Authors: Walski Thomas M. , Clyne Robert E. 
Published: February 2018

Field‐tested water service lines provide data to facilitate more accurate sizing of pipes, valves, and meters.With the installation of residential fire sprinkler systems becoming more widespread, the city of Edmonton, Alta., foresaw a need for better guidelines for designing and sizing these systems. The city constructed experimental test service lines to obtain up‐to‐date information on head loss for copper, polyethylene, and polyvinyl chloride pipe, as well as associated meters and valves. Test results and data are presented here along with equations that can be used to more accurately calculate pipe sizes.
Assessing plant performance using MPA
Authors: Hancock Carrie M. , Ward J.V. , Hancock Keith W. , Klonicki Patricia T. , Sturbaum Gregory D. 
Published: February 2018

Knowledge of microbiotic particulate composition provides valuable information for assessing treatment plant performance and enhancing plant operation.Concentration of microbiota and total particulates in raw and finished water samples from 55 conventional treatment plants was compared. Analyses included (1) enumeration and identification of the microbiota, (2) direct measurement of the pellet volume of total particulates after laboratory centrifugation, (3) total particle counts, and (4) Giardia and Cryptosporidium detection. Organism reduction based on microscopic particulate analysis in the raw and finished waters ranged from –0.8 to 6.0 log. There was a significant correlation between reduction values generated by organism counts, centrifugate pellet measurements, and particle counts. However, only organism reduction values remained consistent regardless of influent turbidity or flocculent material present in the effluent. Because of low concentrations and intermittent occurrence, counts of Giardia and Cryptosporidium did not accurately reflect treatment plant performance.
Creative funding brings RO to small system
Authors: Cress Barry W. 
Published: February 2018

Both the drinking water and the economy have improved in Las Animas, Colo.The problematic nature of water quality in the Arkansas River east of Pueblo, Colo., has made the development of good public water supplies a challenge. The Colorado municipality of Las Animas, which has wells in the river's alluvial aquifer, has been plagued by high levels of water hardness and dissolved solids. This factor and the region's marginal economy have impeded the ability of this rural community to grow. Thanks to the pooling of funds from several sources, the construction of a reverse osmosis treatment plant has become a reality. Much of the cost of the new plant was paid through grant funds.
Restructuring small systems
Authors: Castillo Eloise Trabka , Rubin Scott J. , Keefe Sally K. , Raucher Robert S. 
Published: February 2018

Data from this study could be useful for shaping statewide or national restructuring policies.Physically interconnecting small water systems with larger ones or creating networks of shared management and other expertise might provide a long‐term solution to the problems facing small water systems. Using a geographic information system to display results and screen for geographic barriers, the authors analyzed restructuring potential in 17 states by calculating distances between small and nearby larger water systems and applied screening criteria to indicate whether the restructuring option would be cost‐effective. Physical interconnection with a large system may be economically feasible for up to 35 percent of small community water systems, although in most states examined it would be cost‐effective for only 10–20 percent of them based on the criteria used here. However, the potential for large systems to provide satellite services to small systems is high in the states evaluated. These results cannot be used to implement any particular restructuring option, but they provide insight into overall restructuring potential.
Physical—chemical mechanisms in slow sand filters
Authors: Weber‐Shirk Monroe L. , Dick Richard I. 
Published: February 2018

Efficiency of physical–chemical particle removal increases with particle accumulation within the filter bed.Physical–chemical and biological particle removal mechanisms in slow sand filters were investigated at bench scale. Physical–chemical particle removal mechanisms were significant for particles throughout the size range analyzed (0.75–10 μm). Influent particle concentration and previously removed particles affected physical–chemical particle removal. Particle removal efficiency increased with particle accumulation within the filter bed.
Research needs for small water systems: a survey
Authors:   Small Systems Research Committee
Published: February 2018

Four of seven areas identified as requiring research have to do with management and policy issues.A survey of perceived research needs of small water systems was conducted with state regulatory agencies and engineering consulting firms. The following were identified as the seven most important areas for research: funding, financing, and costs; adequate qualified staffing, supervision, and operator training; system viability; corrosion control and corrosion by‐products; appropriate and reliable efficient treatment technology; disinfection by‐products; and the heavy burden of regulations and monitoring requirements.
NOM removal by slow sand filtration through iron oxide–coated olivine
Authors: McMeen Chris R. , Benjamin Mark M. 
Published: February 2018

A 16‐month study indicates slow sand filtration through iron oxide–coated olivine significantly improves NOM removal.A 16‐month pilot study compared iron oxide–coated olivine (IOCO) with uncoated olivine and plain sand as a medium for slow sand filtration. Three columns, each containing one of the media, were fed water from one proposed and one existing water supply source, and the removal efficiencies of natural organic matter (NOM) in the columns were compared. Consistent with previous work, NOM removal (measured as dissolved organic carbon or UV254) was slight in both the sand‐packed and olivine‐packed columns. However, removal of NOM was dramatically better in the IOCO‐packed column. This improved performance could be attributed to both more efficient adsorptive removal of NOM and greater bioactivity in the IOCO column. During the test period, there was no indication that the adsorptive capacity of the IOCO was approaching exhaustion, suggesting that the adsorption sites were being bioregenerated. The performance of the IOCO warrants further evaluation as a technique for removing disinfection by‐product precursors, particularly in small systems.