bluuebunny/crossref_metadata_2025 huggingface dataset:
Organonitrogen herbicides in the lower Kansas River basin
Authors: Stamer John K. , Zelt Ronald B.
Published: February 2018

Atrazine, which is not readily removed by conventional treatment, may cause problems for water utilities in agricultural areas.

To help managers, planners, and regulators determine when and where surface waters are likely to be adversely affected by organonitrogen herbicides, the authors analyzed various data on the distribution of these compounds in the lower Kansas River basin. They found that atrazine was the most frequently detected herbicide, was found in the highest concentrations, and was most likely to exceed the maximum contaminant level. The highest atrazine concentrations in the water were measured where the largest amounts of atrazine had been applied to the land, and median concentrations were higher in spring and summer than in fall and winter. Atrazine and chemically similar herbicides are not effectively removed by traditional water treatment. The Kansas State Board of Agriculture has established a pesticide management area to decrease the amount of atrazine that enters surface water.
The current regulatory agenda: an update
Authors: Pontius Frederick W. , Roberson J. Alan
Published: February 2018

Major changes to USEPA's current regulatory agenda are anticipated when the SDWA is reauthorized.

Three earlier articles (published in the Journal in February 1990,March 1992, and February 1993) reviewed the history, content,status, and schedule of regulations mandated by the Safe Drinking Water Act. Current developments related to these rules are presented in this article.
Managing the financial condition of a utility
Authors: Amatetti Edward J.
Published: February 2018

Utilities that demonstrate the ability to best manage potential financial risks will be in the best position to obtain low‐cost financing in the future.

The ability of a utility to obtain needed financing depends on its ability to convince the investor market of its creditworthiness. It follows that creditworthiness should be an explicit goal of utilities, like good customer service and an adequate supply of safe water. Managing creditworthiness effectively means managing future financial risk. The sources of financial risk in water utilities are discussed, as are ways to lower the financial risk profile over time. The minimization of risk through growth management, effective rate design, and the regulatory process is covered, and the changing role of the financial manager is explained.
Small systems and SDWA reauthorization
Authors: Shanaghan Peter E.
Published: February 2018

USEPA's small systems coordinator summarizes key elements of the agency's report to Congress, emphasizing the issues of viability, low‐cost technology, and financing.

Small systems issues have been a prominent feature of deliberations on the Safe Drinking Water Act (SDWA) since its initial formulation. In 1993 the US Environmental Protection Agency (USEPA) prepared a report to Congress that contained a detailed discussion of the SDWA compliance challenges faced by small water systems. This article focuses on three of the major small system issues identified in the report to Congress– viability, lower‐cost technology, and financing—and discusses how USEPA's reauthorization recommendations would address these issues.
Commercial labs: how accurate are they?
Authors: Clancy Jennifer L. , Gollnitz William D. , Tabib Zhanet
Published: February 2018

In general, commercial laboratories show a lack of proficiency in testing for Giardia and Cryptosporidium.

The authors conducted a blind survey of 16 commercial laboratories in order to evaluate their ability to test for Giardia and Cyptosporidium using the American Society for Testing and Materials (ASTM) method. After filters were spiked with approximately 740 Giardia cysts and Cyptosporidium oocysts or 500 cells of the alga Oocystis, they were sent to the laboratories for analysis. For the laboratories that submitted reports, Giardia cyst recoveries ranged from 0.8 to 22.3 percent, averaging 9.1 percent; Cyptosporidium oocyst recoveries ranged from 1.3 to 5.5 percent, averaging 2.8 percent. Four of the laboratories falsely reported the Oocystis as positive, four laboratories failed to recover the Giardia cysts, and six laboratories failed to recover the Cryptosporidium oocysts. Not all laboratories strictly followed the ASTM method. The majority of laboratories need to make improvements in one or more of the following areas: response to clients, adequacy of sampling equipment and directions for use, analytical methods, and data accuracy.
Information Collection Rule Delayed
Authors: Pontius Frederick W.
Published: February 2018

The first rule to be proposed and promulgated as a result of the regulatory negotiation (reg neg) for the Disinfectants‐Disinfection By‐products (D‐DBP) Rule is the Information Collection Rule (ICR). The ICR is designed to fill gaps in the data so that a better scientific basis can be provided for future rules. The reg‐neg advisory committee agreed that the ICR should be proposed December 1993 and promulgated June 1994 so that monitoring could begin October 1994. The proposed rule was published February 10, 1994, in the Federal Register. The rule applies to systems that serve more than 10,000 people and that use surface water or groundwater under direct influence of surface water and the groundwater systems that serve more than 50,000 people. An overview of the July 2, 1993, draft ICR was presented in this column in the October 1993 issue. The proposed ICR is consistent with the requirements summarized in this earlier article, but several important changes have been made. The author lists these changes in the current article.
The pitting corrosion of copper
Authors: Edwards Marc , Ferguson John F. , Reiber Steve H.
Published: February 2018

To solve or prevent copper pitting problems, it is first necessary to achieve a clearer understanding of copper corrosion theory, parts of which are currently not supported by practical experience.

Some current theories of copper pitting are contradicted by practical experience. Although it has been theorized that chloride initiates copper pitting attack, simple experiments show that the presence of chloride ion actually tends to decrease the likelihood that pitting will occur. In contrast, sulfate plays no role in pitting theory, yet sulfate has consistently demonstrated a propensity to initiate and propagate copper pitting. New theories are required to reconcile pitting theory and practical observation in order to allow the rational mitigation of copper pitting problems. In addition, the presence of natural organic matter (NOM) in water supplies prevents or inhibits certain copper corrosion problems. As a result, recent efforts to remove NOM as a means of controlling disinfection by‐products may lead to increased copper corrosion problems.
Evaluating buoyant coarse media flocculation
Authors: Schulz Christopher R. , Singer Philip C. , Gandley Robert , Nix James E.
Published: February 2018

In laboratory and field studies, a two‐stage buoyant coarse media flocculator provided settled water turbidities <2 ntu at loading rates as high as 12 gpm/sq ft.

A new type of coarse media flocculator, using buoyant media instead of the heavier gravel in order to facilitate cleaning, was evaluated in laboratory and field studies. The results indicate that a two‐stage buoyant coarse media (BCM) flocculator provided effective treatment at higher loading rates and shorter residence times than are typically employed in designing mechanical flocculators. Source‐water quality and coagulant chemistry directly influenced flocculator performance and dictated the type of flocculator configuration selected. Tapering velocity gradients in the first‐stage flocculator enhanced performance. The authors recommend that additional studies be performed to develop reliable design and operating criteria for full‐scale BCM flocculators.
Long‐term effects of sludge application to land
Authors: Geertsema Wesley S. , Knocke William R. , Novak John T. , Dove Dennis
Published: February 2018

Applying alum sludge to field research plots appears to have had no effect on the soil, groundwater, or growth of pine trees—even after 30 months.

The purpose of this study was to evaluate the long‐term environmental effects of applying alum sludge to land. Investigations at the original field site included soil analysis, soil water monitoring, groundwater monitoring, and analysis of tissues from pine needles. No long‐term (30 months) effects were observed, and the authors conclude that alum coagulant sludges can be applied to forest lands at loading rates of at least 1.5 to 2.5 percent by dry weight without adverse effect.
Cost estimates for membrane filtration and conventional treatment
Authors: Wiesner Mark R. , Hackney John , Sethi Sandeep , Jacangelo Joseph G. , Laîé Jean‐Michel
Published: February 2018

Membrane processes may offer small facilities a less expensive alternative for the removal of particles and organic materials.

Costs of several ultrafiltration and nanofiltration processes are compared with the cost of conventional liquid‐solid separation with and without GAC adsorption for small facilities. Data on raw‐water quality, permeate flux, recovery, frequency of backflushing, and chemical dosage obtained from a pilot study were used with a previously developed model for membrane costs to calculate anticipated capital and operating costs for each instance. Data from the US Environmental Protection Agency were used to estimate conventional treatment costs. All of the membrane process calculations showed comparable or lower total costs per unit volume treated compared with conventional treatment for small facilities (<200,000 m3/d or about 5 mgd).
Effect of selected anions on copper corrosion rates
Authors: Edwards Marc , Meyer Travis , Rehring John
Published: February 2018

Under conditions typical of drinking water, copper demonstrates a tendency toward increased corrosion that is inhibited only by the presence of chloride or bicarbonate at certain pH values.

Copper passivation was examined in simple solutions that contained bicarbonate, chloride, perchlorate, nitrate, or sulfate at pH 5.5, 7.0, 8.5, and 10. Copper corrosion rates increased with aging in the presence of sulfate, nitrate, or perchlorate at all pH values, whereas copper passivated in the presence of chloride at pH ≥7.0. Bicarbonate ion was discovered to have a dual nature that was pH‐dependent, causing activation (increased corrosion rates) after aging at pH ≤7.0 and passivation at pH ≥8.5. Activation in the presence of bicarbonate was due to catalysis of oxygen reduction (cathodic) reactions, whereas sulfate, nitrate, and perchlorate increased the copper oxidation (anodic) reaction rates after aging.
Complacency Caused Milwaukee's Crypto Outbreak
Authors: Smith Velma
Published: February 2018

All in all, Milwaukee's experience with Cryptosporidium had a stiff price‐‐much human suffering as well as an estimated $37 million in lost wages and productivity. Discovering how it happened might not help the people who suffered most from the worst drinking water disaster in recent US history. But finding answers is crucial to preventing further cases of contamination‐‐in Milwaukee or in any other community served by the nation's 200,000 public water systems. The author discusses why she feels the Milwaukee episode with Cryptosporidium happened and what should be done to prevent it from happening again.
Biodegradation of NOM: effect of NOM source and ozone dose
Authors: Goel Sudha , Hozalski Raymond M. , Bouwer Edward J.
Published: February 2018

Batch experiments proved to be effective for obtaining a preliminary estimate of the biodegradation potential of NOM.

Batch degradation experiments were conducted to evaluate the extent of biodegradation of natural organic matter (NOM) as a function of ozone dosage. Four NOM sources that might be encountered in drinking water treatment were characterized and tested. The biodegradability of all sources was enhanced as the ozone dose was increased from 0 to 7.3 mg ozone/mg total organic carbon (TOC). Increased ozonation resulted in cnsistently improved TOC removals for NOM souces having a large fraction of high‐molecular‐weight organics. Greater biodegradation was observed for the unozonated sources with lower UV‐absorpotion ‐to‐TOC rations and larger fraction of low‐molecular‐weight organics.
Measuring UV‐absorbing organics: a standard method
Authors: Eaton Andrew
Published: February 2018

Under the Information Collection Rule, water utilities across the United States will gather data on UV‐absorbing organics in an attempt to correlate this parameter with the occurrence of disinfection by‐products precursors.

The method described here was prepared by the Joint Task Group for Method 5910. It will be included in the nineteenth edition of Standards Methods but is being published now so that it will be available for use with the Information Collection Rule. The method is intended to indicate the aggregate concentration of UV‐absorbing organics, which may possibly be correlated with precursors of disinfection by‐products. Details of the experimental method, results and discussion, and quality control are included, as well as a description of the principle of the method and interferences. Interlaboratory precision data are shown.
Membrane air‐stripping: effects of pretreatment
Authors: Castro Kevin , Zander Amy K.
Published: February 2018

Membrane air‐stripping shows promise for removing volatile contaminants from low‐pH and low‐chlorinewaters but is incompatible with ozonated waters or waters with high pH or high‐chlorine concentration.

Microporous polypropylene hollow‐fiber membranes offer significant advantages over packed‐tower aeration for removing volatile organic chemicals. A laboratory study assessed the performance of membrane air‐stripping in continuous operation, while exposed to various pretreatments. Results indicate that membrane air‐stripping is compatible with low‐pH or low‐chlorine waters but not with waters of high pH or high‐chlorine concentration or those that are ozonated.
Evaluating NF for DBP control with the RBSMT
Authors: Allgeier Steven C. , Summers R. Scott
Published: February 2018

A rapid bench‐scale membrane test was designed to capture critical aspects of full‐scale systems, particularly water flux and solute rejection, while maintaining the benefits of a bench‐scale system.

At the center of the rapid bench‐scale membrane test (RBSMT) is a tangential‐flow flat‐sheet cell with recycle, which represents a differential element of a fullscale spiral‐wound nanofiltration element treating the average feed for a full‐scale system. The RBSMT incorporates operational parameters, such as recovery, pressure, crossflow velocity, and hydraulic conditions that approximate field‐scale operation. Four conventionally treated surface waters and one untreated groundwater were evaluated using the RBSMT. All of the waters tested would meet the Stage 1 requirements of the Disinfectants/ Disinfection By‐product Rule after nanofiltration, and the four surface waters would satisfy the Stage 2 requirements.
Earthquake lessons pay off in Sounthern California
Authors: Young Michael B. , III Edward G. Means
Published: February 2018

Superior design standards, long‐term planning and preparation, and the development of in‐house repair capabilities helped MWDSC crews manage when the 1994 Northridge earthquake struck.

After the Sylmar earthquake in 1971, the Metropolitan Water District of Southern California established emergency planningprocedures. In 1994, the Northridge earthquake in the same area put those preparations to the test. Much of the groundwork proved helpful: an Emergency Operations Center was activated within 40 minutes, and reconnaissance patrols completed their damage inspection within just 5 hours. In addition, a decision to buy heavy machining equipment paid off when crews were able to fabricate new pipe sections for the damaged Jensen Filtration Plant. Lessons learned in 1994 were that practice sessions do not duplicate the actual experience of an earthquake; human emotional response to disaster is unpredictable; agencies can expect outside assistance and do not need large stockpiles of extra equipment; and a business resumption plan needs to be established so office work can continue during an emergency.
LA's rehearsal for the big one
Authors: McReynolds Larry , Simmons Robert L.
Published: February 2018

The Los Angeles Department of Water and Power fully restored service within five days of a destructive, 6.8‐magnitude earthquake.

Although the 6.8‐magnitude Northridge earthquake in 1994 was not “the big one” Californians fear, it caused as much damage to the San Fernando Valley as would be expected from the big one—which, experts say, will have a magnitude of 8.0 or higher. This extensive damage occurred because the epicenter was in a large population center, and the quake caused record ground accelerations. The devastation tested the preparedness of the Los Angeles Department of Water and Power. Extensive damage to the water system left 500,000 people without water or fire protection, but water trucks supplied citizens at various locations while repair crews worked around the clock. Full service was restored within five days to 99 percent of customers.
Planning For Residential Fire Sprinklers
Authors: Walski Thomas M.
Published: February 2018

Fire sprinkler installation raises complicated issues.

Moderator of this Roundtable discussion was Thomas M. Walski, associate professor, Department of Environmental Engineering, Wilkes University, Wilkes‐Barre, PA 18766. Other participants were Jerry Dobrovolny, assistant waterworks engineer, City of Vancouver, 453 W. 12th Ave., Vancouver, BC V5Y 1V4; James D. Lake, technical services manager, National Fire Sprinkler Association (NFSA), POB 1000, Patterson, NY 12563; Kanwal Oberoi, water network engineer for the City of Edmonton Public Works, 8720‐106A Ave., Edmonton, AB T5H 0S3; and Joellen C. Thompson, hydraulic engineer, City of Grand Rapids Water System, 530 Ball Ave. N.E., Grand Rapids, MI 49503. The group met June 19, 1994, in New York, N.Y.
Corrosion control on the basis of utility experience
Authors: Dodrill Donna M. , Edwards Marc
Published: February 2018

Although selection of corrosion control optimization strategies is more art than science, utility experiences can provide a basis for rational decision‐making.

Utility experience under the Lead and Copper Rule was examined to provide improved insight into corrosion control. Average 90th percentile lead concentrations were highest in very‐low‐alkalinity waters (<30 mg/L as CaCO3) at utilities that did not use inhibitors; lead release was significantly reduced at higher alkalinities. Average lead releases were 20–90 percent lower for utilities using phosphate inhibitors (orthophosphates, polyphosphates, and blended phosphates) in very‐low‐alkalinity waters than for utilities not using inhibitors. At alkalinities of 30–74 mg/L as CaCO3 and at pH values > 7.40, it appeared that polyphosphate inhibitors had adverse effects on average lead release. Utilities with pH > 7.40 and high‐alkalinity waters had the highest copper concentrations. Phosphate inhibitors were usually beneficial in mitigating copper release; however, most benefits were at utilities with pH > 7.80 and alkalinity < 90 mg/L as CaCO3. Inhibitors appeared to adversely affect average copper release in some pH and alkalinity categories.
Network maintenance through analysis of the cost of water
Authors: Cabrera Enrique , Andrés Miguel , Planells Francisco
Published: February 2018

A methodology based on the history of a system's pipe repairs—and incorporating cost analyses—indicates the best time to begin a leak detection program and when consideration should be given to replacing the network.

A pipe's average life—normally between 40 and 100 years—is a highly variable parameter. This article proposes a method based on the history of repairs carried out on a network that allows an estimate to be made of the time a program for detection and repair of leaks should be started, as well as when the network should be replaced. Because some of the parameters are difficult to estimate, it is convenient to assess their influence on the results via sensitivity analysis.
Bench‐scale evaluation of GAC for NOM control
Authors: Summers R. Scott , Hooper Stuart M. , Solarik Gabriele , Owen Douglas M. , Hong Seongho
Published: February 2018

Although these authors confirm that the RSSCT is able to predict the breakthrough behavior of full‐scale activated carbon columns, they emphasize the importance of obtaining a representative batch water sample for the RSSCT.

The Information Collection Rule (ICR) will require that some utilities perform disinfection by‐product (DBP) precursor removal studies. The rapid small‐scale column test (RSSCT), a bench‐scale granular activated carbon (GAC) test designed to reduce time and costs associated with field‐scale studies, has been proposed as an alternative to evaluate GAC performance for the ICR. RSSCT scaling equations maintain similitude with full‐scale GAC systems, and therefore the RSSCT directly assesses the concentration breakthrough in a full‐scale GAC column. A review of past studies shows that the RSSCT has successfully predicted field‐scale performance for the control of natural organic matter and DBP precursors. The results of a current study emphasize the importance of obtaining a representative batch water sample for the RSSCT. A cost analysis based on using GAC to satisfy stage 1 and stage 2 requirements of the Disinfectants/Disinfection Byproducts Rule suggests that minimizing empty bed contact time will reduce capital costs associated with GAC contactors.
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.
Inside the Information Collection Rule
Authors: Pontius Frederick W.
Published: February 2018

This article focuses on the content of the Information Collection Rule (ICR) proposed February 10, 1994, and promulgated May 14, 1996. The ICR has three major components: applicability monitoring and treatment studies, monitoring requirements for DBPs and related parameters, and microbial monitoring requirements. The general requirements for each component of the ICR are reviewed here, but not all details can be presented. The US Environmental Protection Agency (USEPA) has developed extensive educational materials to assist water utilities in complying with the ICR.
Waterborne Disease Outbreaks and Small Systems
Authors: Fox Kim R.
Published: February 2018

Kim R. Fox is an environmental engineer with the Water Supply & Water Resources Div., US Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268; telephone 513‐569‐7820, e‐mail Fox.Kim@epamail.epa.gov.
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.
What Do the SDWA Amendments Mean for Small Systems?
Authors: Saxena Sanjay
Published: February 2018

The 1996 Safe Drinking Water Act (SDWA) amendments mark the dawn of a new era in ensuring the safety of America's drinking water. The amendments represent a balanced, integrated framework of reform that offers opportunities for states and water systems. One of the most important provisions in the amendments creates a new state revolving loan fund program to provide loans for SDWA compliance‐related capital improvements to drinking water treatment facilities. Three major new prevention provisions are discussed: source water protection, capacity development, and operator certification. A new amendment requirement states that water systems must prepare an annual consumer confidence report that must include information on the source of supply and finished water quality. Other regulatory improvements are discussed as well.
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.
SDWA Then and Now
Authors: Howell Mary L.
Published: February 2018

When President Clinton signed the Safe Drinking Water Act (SDWA) amendments August 6, 1996, small systems across the nation got a reprieve. There is flexibility under the new act; it encourages partnership approaches and supports the fact that one size does not fit all. This article discusses new funding that is available, the annual report requirement, basing standards on costs and risks, source water protection, operator certification, technical assistance, and allowed variances.