bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of ozonation on coagulation of NOM using polymer alone and polymer/metal salt mixtures
Authors: Edwards Marc , Benjamin Mark M. , Tobiason John E. 
Published: February 2018

The possible benefits of reduced coagulant demand and head loss resulting from preozonation must be weighed against increased organic matter in the finished water.Prior investigations have identified many of the mechanisms by which natural organic matter (NOM), coagulant, and particles interact in ozonated systems. This study investigated the effects of ozonation on coagulation with cationic polymer and with polymer‐metal salt mixtures. Preozonation decreased the concentration of NOM that reacts with polymer, reducing organic carbon removal, polymer coagulant demand, and the rate of head loss buildup during direct filtration. The effects of ozonation in systems using dual coagulants (alum‐polymer or ferric chloride‐polymer) were a blend of the effects observed for the coagulants individually.
Penalties for SDWA and CWA violations
Authors: Rubin Kenneth A. 
Published: February 2018

From reasonable penalties to deliberate overkill, USEPA has imposed sanctions on water utilities that violate the Safe Drinking Water Act or the Clean Water Act.Although the number of enforcement actions against water suppliers to date has been limited, increasing regulation means that utilities are more likely to face US Environmental Protection Agency (USEPA) sanctions under the Safe Drinking Water Act and, to some extent, the Clean Water Act. In this article the author reviews possible criminal and civil actions—the latter consisting of administrative and court actions and citizens' suits—and briefly describes eight cases that exemplify various enforcement actions taken in the last few years. Large monetary penalties are not USEPA's usual goal in acting against a water supplier unless the supplier deliberately makes false reports. Instead, USEPA usually seeks to impose fines that match the amount a violator saved by not complying with regulations. Reorganization last fall at USEPA created the Office of Enforcement and Compliance Assurance, which indicates the agency's intention to streamline enforcement efforts.
Costs and benefits of current SDWA regulations
Authors: Auerbach Jan 
Published: February 2018

The total national cost of compliance with current SDWA‐mandated drinking water regulations is estimated to be $1.4 billion annually for public water systems.In 1993 Congress directed the US Environmental Protection Agency (USEPA) to prepare a report examining the technical and economic capacity of states and public water systems to implement USEPA drinking water regulations. As part of the report, USEPA was required to address the costs and benefits of current regulations. USEPA submitted the “Chafce Report”—so called because Senators John Chafee (R‐R.I.) and Frank Lautenberg (D‐N.J.) wrote the amendment that required it— to Congress in September 1993. This article summarizes the portions of the report1 that provide demographic information about public water systems and a summary of USEPA's estimates of the costs and benefits of those regulations.
A survey of BOM in US drinking waters
Authors: Kaplan Louis A. , Reasoner Donald J. , Rice Eugene W. 
Published: February 2018

The data collected in this survey represent the first comparison of three methods for measuring biodegradable organic matter in a wide range of US drinking waters.Bacteria that pose a public health threat through their potential regrowth in water distribution systems derive energy and carbon for their growth from biodegradable organic matter. Three methods for determining biodegradable organic matter—which is necessary if the process of bacterial regrowth is to be fully understood—were compared in this study of a broad range of US drinking waters and treatment processes: the assimilable organic carbon (AOC) assay, the biodegradable dissolved organic carbon (BDOC) assay, and the coliform growth response (CGR). The source of water—surface water versus groundwater—had a strong influence on AOC and BDOC. The correlations between AOC and BDOC, between AOC and dissolved organic carbon (DOC), and between BDOC and DOC were statistically significant. CGR did not correlate well with either AOC or BDOC. The authors caution that these data are limited and urge increased focus on individual systems.
Water conservation for Rhode Island lawns
Authors: McCann Alyson , Gold Arthur J. , Mallon Kathleen , Gorres Josef 
Published: February 2018

Computer modeling helped Rhode Island water professionals choose the best way to educate consumers about lawn irrigation.In 1989, water professionals in Rhode Island developed a program for home lawn irrigation scheduling that adapted an agricultural soil moisture model for use on home lawns. The key to the program, which emphasized supplemental watering only, was a “water factor” that was developed from daily simulation models for lawns on two soil textures. The program was pilot‐tested in 1990 and ran statewide in the 1991 growing season. The simulation model relied on a single weather station for moisture data. Analysis of rainfall amounts suggested that computerized irrigation scheduling for home lawns requires spatially explicit data. Variability in factors such as rooting depth and soil composition caused additional concern about the accuracy of the recommendations. It was concluded the computerized farm‐based irrigation scheduling programs for the Northeast cannot be easily adapted to home lawn water management over a broad area. Instead, emphasis should be placed on linking sprinkler calibration rates to soil types. Low‐maintenance landscaping also should be encouraged in suburban areas.
Implications of discharging potable water in Southern California
Authors: Beuhler Mark D. , III Edward G. Means 
Published: February 2018

Water utility managers need to consider a wide range of effects when controlling discharge parameters.Controlling periodic discharges of potable water into streambeds, reservoirs, and flood‐control channels presents a wide range of challenges for water utility managers. The authors examine the physical, chemical, and biological effects of discharges, which are regulated by the National Pollutant Discharge Elimination System program. They also warn that future regulation of discharges will become more severe, limiting options for utilities and making permits more difficult to obtain.
Monitoring waivers for Phase II and Phase V regs
Authors: Ley Mary Ellen 
Published: February 2018

An assessment program to evaluate the vulnerability of wells to contamination enabled Wisconsin to waive some monitoring requirements.In 1992, student interns assessed the vulnerability of Wisconsin's 3,650 community and nontransient drinking water wells to contamination from pesticides and volatile organic chemicals. This article describes the development of criteria, the assessment process, and the number of waivers issued during the vulnerability assessment program. Cost to the Wisconsin Department of Natural Resources of development and implementation for the first three‐year monitoring period was $400,000. Monitoring waivers will save water systems about $18 million in initial monitoring costs and target resources to problem sites. Sample results to date indicate that fewer than 5 percent of the most vulnerable wells are contaminated.
Evaluating surrogates for disinfection by‐products
Authors: Najm Issam N. , Patania Nancy L. , Jacangelo Joseph G. , Krasner Stuart W. 
Published: February 2018

Data analysis suggests that UV‐254 absorbance is a better indicator than TOC concentration for chlorination by‐product formation in SDS tests—and is substantially easier, faster, and less costly to measure.Each of four low‐bromide waters was coagulated at three pH values (5.5, 7.0, and 8.0), and then simulated distribution system (SDS) chlorination tests were performed. The object of the study was to determine whether total organic carbon (TOC) or UV‐254 absorbance can be employed as an indicator of the trihalomethane (THM) and haloacetic acid (HAA) concentrations formed upon chlorination. Results showed that removal of TOC and UV‐254 always increased with decreasing coagulation pH, but the extent of removal varied with the different waters. Maximum reduction of SDSTHM and SDSHAA5 formation was achieved after coagulation at pH 5.5. UV‐254 proved to be a better surrogate for chlorinated by‐product formation than TOC. The applicability of the correlations to waters with higher bromide levels and different chlorination pH values should be evaluated.
Laboratory‐scale testing of a continuous CLAS process
Authors: Bhowmick Madhumita , Semmens Michael J. 
Published: February 2018

No gases were released to the atmosphere when UV photooxidation was incorporated in a continuous closed‐loop air‐stripping process for removing volatile organic chemicals from water.The removal of five volatile organic chemicals (VOCs) was evaluated by passing the contaminated water once through a hollow‐fiber‐membrane module that received a countercurrent flow of air recycled from an ultraviolet (UV) photooxidation chamber. VOC removal was measured experimentally under a variety of operating conditions. The results compared favorably with the behavior predicted by a mathematical model of the process. When operated as a closed‐loop process, the photooxidation of the VOCs in the gas phase has several advantages over conventional air‐stripping with off‐gas treatment: the end products are reabsorbed back into the water flow; no exhaust gases are released to the atmosphere; and no adsorbent regeneration or disposal costs are incurred.
Arsenic occurrence: USEPA seeks clearer picture
Authors: Reid Joe 
Published: February 2018

USEPA is combining existing data with new survey results in anticipation of proposing a revised arsenic rule next year.With a November 1995 deadline for proposing a new regulation for arsenic, the US Environmental Protection Agency (USEPA) has been moving to develop a clearer picture of arsenic occurrence and exposure throughout the United States. This article summarizes the studies that are the basis for USEPA's estimates of preliminary occurrence and exposure for arsenic, including several newer surveys that add information about low‐level occurrences. The article does not attempt to evaluate the methodology or conclusions of these studies or to weigh the relative importance of one study over another. Better estimates of arsenic occurrence at levels as low as 0.5 μg/L have particular importance, because USEPA could consider a new arsenic limit below 0.05 mg/L. Preliminary occurrence estimates from USEPA show that arsenic occurs primarily in the source water of smaller (serving fewer than 10,000 people) groundwater systems in the western United States.
Alum sludge land application and its effect on plant growth
Authors: Lucas Jay B. , Dillaha Theo A. , Reneau Raymond B. , Novak John T. , Knocke William R. 
Published: February 2018

Addition of phosphorus fertilizer corrected the phosphorus deficiency found in fescue grass at higher sludge application rates.These investigators conducted three greenhouse experiments to determine the impact of alum sludge from the Harwood's Mill water treatment plant, Newport News, Va., on the growth and chemical composition of fescue grass. Fescue yields decreased with increased sludge addition, a trend that was attributed to reductions in plant‐available phosphorus (P) at higher loadings. Supplemental P fertilization corrected this deficiency. Lime addition did not affect yield. The presence of manganese and copper in the sludge increased metal uptake by the plants but did not affect yield.
The effect of shear on the dewatering of water treatment residuals
Authors: Novak John T. , Bandak Nazih 
Published: February 2018

Conditioning with an appropriate polymer at the optimum dosage reduces the tendency of alum sludge to deteriorate under shear and, thus, leads to better dewatering.These researchers investigated, at bench scale, the dewatering performance of drinking‐water treatment plant sludges under varying shear conditions and the effect of conditioning with polymers. It was found that unconditioned alum sludges fracture during mixing and are more sensitive to the intensity of shear than to the mixing time. Polymers reduce this tendency to deteriorate, with the dosage required for the best dewatering depending on both the mixing time and the intensity of shear. Lime‐softening sludges do not deteriorate when subjected to shear
Gaining Access to Capital Markets
Authors: Raftelis George 
Published: February 2018

Financial experts discuss how to shop the bond market.Participants in this Roundtable met in New York, N.Y., on June 21, 1994. Moderator was George Raftelis of Raftelis Environmental Consulting Group Inc., 6100 Fairview Tower, Charlotte, NC 28210. Other participants were J. Chester Johnson, chairman of Government Finance Associates Inc., 71 Broadway, Suite 1301, New York, NY 10006; Edward S. Krauss, vice‐president of the Public Finance Department, Moody's Investors Service, 99 Church St., New York, NY 10006; Thomas E. Taylor, executive director of Upper Trinity Regional Water District, 396 W. Main St., Lewisville, TX 75067; and Clarence O. Warnstaff, director of public utilities, City of Virginia Beach, Municipal Center, Virginia Beach, VA 23456.
An evaluation of algal enumeration
Authors: Rashash Diana M.C. , Gallagher Daniel L. 
Published: February 2018

The data presented here can be used by water utility personnel who use the Palmer–Maloney method to approximate the standard deviation of their algal counts relative to the observed cell density.The Palmer–Maloney (P–M) counting chamber method, as described in Standard Methods section 10200‐F.2b, was used to enumerate 10 different unialgal cultures representing three algal morphologic types (i.e., colonial, unicellular, and filamentous). The standard deviations of counts obtained by the P–M method were not constant. Although the absolute standard deviation increased with increasing cell density, the relative standard deviation decreased from >30 percent at low cell density to <10 percent at high cell density. Variability among the three morphological types was similar.
Inorganic metal polymers: preparation and characterization
Authors: Gray Kimberly A. , Yao Chonghua , O'Melia Charles R. 
Published: February 2018

It is possible to produce stable preparations of partially neutralized aluminum chloride solutions in which cationic aluminum polyelectrolytes predominate, but attempts to produce similar stable preparations containing cationic iron(III) polyelectrolytes were unsuccessful.One method to improve the effectiveness of inorganic metal coagulants in water treatment is to partially neutralize concentrated metal salt solutions prior to their addition to the raw water and thus preform polymeric metal species, the actual coagulants. In this way coagulant chemistry can be controlled and proper solution conditions for the formation of desired coagulant species can be maintained. This article compares polymeric preparations of aluminum and ferric chloride salts with respect to preparation parameters and the extent and stability of polymerization.
Integrated planning: a common‐sense approach
Authors: Borak Jonathan , Giannini Paul 
Published: February 2018

Planning that integrates the various regulatory requirements applicable to water utilities is a practical way to anticipate emergencies.Overlapping federal emergency planning requirements are imposed on all but the smallest water and wastewater facilities. The various regulations pose complex challenges to facility managers, who must balance the legal need to prepare written plans responsive to individual laws with the practical need that response plans be clear and consistent. The integrated emergency planning process enables utilities to appreciate potential regulatory conflicts and accommodate them in a plan that can be readily implemented, meets legal requirements, and is less expensive to create and maintain. The integrated emergency planning process begins with an understanding of the various laws and regulations.
Hourly monitoring of single‐family residential areas
Authors: Rhoades Stephen D. 
Published: February 2018

A project in Austin, Texas, provides the city with the statistical basis for refining customer class categories and updating the rate structure.For several summers Austin, Texas, has used transit‐time ultrasonic meters to monitor hourly water use and derive coincident and noncoincident daily and hourly peaking factors for a sample of the city's single‐family residential customer class. These data have been used in a formal cost‐of‐service study for setting cost‐based rates. Additionally, the data have set the stage for operational, conservation, and pricing studies.
Giardia and Cryptosporidium in raw and finished water
Authors: LeChevallier Mark W. , Norton William D. 
Published: February 2018

The D/DBP Rule and the ESWTR must be orchestrated carefully to ensure protection of public health.The American Water System has conducted extensive monitoring of its operations since 1988. Analysis of 347 surface water samples collected between 1988 and 1993 showed that the prevalence rate of Giardia and Cryptosporidium was 53.9 percent and 60.2 percent, respectively. But because the parasite assay does not indicate viability or virulence, these results do not necessarily indicate that these water systems were at risk from waterborne pathogens. To supplement coagulation and filtration, the average system will have to apply sufficient disinfection to reduce viable Giardia levels by 3.1 log10. An analysis of existing disinfection practices shows that most systems are already applying disinfectant at a level sufficient to reduce Giardia levels. However, the proposed Disinfectants/Disinfection By‐products (D/DBP) Rule may hamper the ability of water utilities to apply sufficient disinfection under current operating conditions. Careful integration of the D/DBP and the Enhanced Surface Water Treatment rule is encouraged.
Developing an action level for Cryptosporidium
Authors: Haas Charles N. , Rose Joan B. 
Published: February 2018

The authors suggest yardsticks to gauge the significance of finished water oocyst densities.From consideration of prior monitoring studies on finished water Cryptosporidium and measurements made during and after detected outbreaks, an action level for Cryptosporidium oocysts is defined. At concentrations within and above 10–30 oocysts/100 L in finished water, the possibility of an outbreak would appear to exist. In the lower range of this region and below, outbreaks may occur but may not be detectable. If a single sample exhibits counts at or above this level, further sampling on an expedited basis or consideration of supplemental performance data to support a decision should be undertaken.
Slow sand filters for a small water system
Authors: Riesenberg Felix , Walters Brien B. , Steele Andy , Ryder Robert A. 
Published: February 2018

Slow sand filtration improved water quality in Camptonville, Calif.Slow sand filtration was selected to meet the Surface Water Treatment Rule requirements for the community of Camptonville, Calif. The slow sand filtration facility uses precast concrete vaults, hauled by truck to the site and laid out in a linear arrangement to adjust to the contour of the steep hillside site. This alternative filtration process is credited by the California Department of Health Services with 2‐log Giardia and 1‐log virus reduction. A 3‐log Giardia and 4‐log virus removal can be achieved with disinfection. The facility began operation in December 1991 and has maintained a treated water turbidity <1.0 ntu, despite stream turbidities of >30 ntu. The process effectively removes high levels of iron and manganese from the community's backup groundwater supply. In addition, low construction and operating and maintenance costs have kept customers' costs down.
An update of the federal regs
Authors: Pontius Frederick W. 
Published: February 2018

Because of resource limitations and pending reauthorization of the Safe Drinking Water Act, the pace of regulatory activity has slowed considerably.This article reports the current developments related to rules promulgated or proposed under the Safe Drinking Water Act, such as the Lead and Copper Rule, Phase V Rule, the Disinfectants/Disinfection By‐products Rule (including the Enhanced Surface Water Treatment Rule and the Information Collection Rule), the Radionuclides Rule, and the Sulfate Rule. Anticipated new rules that will update analytical methods, reestablish regulatory priorities, and streamline revisions to current regulations are reviewed as well.
Developing the Ground Water Disinfection Rule
Authors: Macler Bruce A. 
Published: February 2018

A different logic must be applied to regulations for systems that use true groundwater.The US Environmental Protection Agency (USEPA) is developing requirements for disinfection of groundwater‐based drinking water systems. The Ground Water Disinfection Rule regulatory workgroup, made up of representatives from USEPA, states, utilities, and other interested parties, recognizes that most drinking water systems using true groundwater supplies are substantially different from those using surface water. These differences have as much to do with the systems' relative sizes and economic circumstances as with the source water and types and degree of treatment currently in place. This article discusses the context, issues, status, and directions of this rule.
Public–private partnerships
Authors: Shanker Amy , Rodman Len 
Published: February 2018

For some water utilities, in some areas of operation, private‐sector involvement may hold the key to improved service and a healthier bottom line.Privatization is being considered as a way to increase competition and achieve more cost‐effective infrastructure improvements in US public utilities. A broader term—public–private partnerships—includes full privatization as well as other innovative ways through which water utilities can increase their competitiveness. Among other techniques are contract services, turnkey facility construction, and developer financing. Many of these techniques enable utilities to operate and treat more efficiently and to reap cost benefits. Drawbacks to private involvement may but do not necessarily include labor problems, lack of control by the utility, and lack of support from the community.
Influence of NOM composition on nanofiltration
Authors: Nilson James A. , DiGiano Francis A. 
Published: February 2018

Hydrophilic NOM caused little permeate flux decline and was poorly rejected compared with hydrophobic NOM.The influence of natural organic matter (NOM) composition on the rejection of total organic carbon (TOC), permeate water flux, and the strength and amount of NOM association with the membrane was examined in bench‐scale nanofiltration studies. NOM composition was manipulated by fractionation into hydrophilic and hydrophobic components and by powdered activated carbon (PAC) pretreatment with subsequent dilution to control for TOC concentration. Hollow‐fiber nanofilters made of negatively charged polysulfone were used in a batch recycle system. Hydrophobic NOM was shown to be responsible for nearly all permeate flux decline and was more highly rejected by the membrane than hydrophilic NOM. Using membrane‐feed solutions with the same TOC concentration, the authors found that the NOM remaining in solution after PAC pretreatment caused greater permeate flux decline and was more poorly rejected than the original mixture of NOM. NOM recovered from the membrane after nanofiltration was predominantly high‐molecular‐weight material (i.e., > 30,000 daltons).