AUGUST 1995 81

M

Technical Note:Interference of Br

, BrO3

, and

ClO3

with DOX determination Although no interference from bromate or chloratewas detected, a small positive interference of about12 g Cl /L per 1 mg/L bromide was found in thepresence of background organic matter.

James M. Symons

I N F O R M A T I O N C O L L E C T I O N R U L E

ethod 5320 B for dis-solved organic halogen (DOX)1 states in section bof the General Discussion:

Inorganic substances such as chloride, chlorate, bro-mide, and iodide will adsorb on activated carbon to anextent dependent on their original concentration in

the aqueous solution andthe volume of sampleadsorbed. Positive inter-ference will result if inor-ganic halides are notremoved. Treating theactivated carbon with aconcentrated aqueoussolution of nitrate ioncauses competitive des-orption from the activatedcarbon of inorganic halideand washes inorganichalides from other sur-faces (emphasis added).

In the dissolved organic halogen (DOX) analytic test, prior tocombustion, the granular activated carbon (GAC) on which theDOX is adsorbed is washed with a sodium nitrate solutiondesigned to remove any inorganic chloride that may have alsoadsorbed to the GAC. Thus, a potential positive interference isremoved. This study investigated the effectiveness of the nitratewash in eliminating possible interferences from bromide,bromate, and chlorate ions. No interference was detected frombromate or chlorate ion, but a small positive interference ofabout 12 g Cl/L per mg/L of bromide ion was found in thepresence of background organic matter.

(C) 1995 American Water Works Association

82 JOURNAL AWWA

In section 5, A, 3, however, themethod calls for only testing 100-, 500-,and 1,000-mg Cl/L solutions to ensurethat significant interference is not a prob-lem from inorganic halide interference.

In previous work, because avoidinginorganic halide interference during thedetermination of dissolved organiciodine by method 5320 B1 in the pres-ence of high concentrations of iodideion was difficult (many nitrate washesrequired)2, an investigation was begunto determine the effectiveness of method5320 B for controlling interference frombromide ion during a DOX determina-tion. This is important because of thecurrent interest in the formation of dis-infection by-products (DBPs) during thedisinfection of bromide-containingwaters. DOX determinations often playan important role in those investiga-tions. Because of current interest, bro-mate and chlorate ion interference wasalso studied.

TestsAll tests were performed according to

method 5320 B,1 using an organic halo-gen analyzer* shown to be comparable tothe more commonly used instrument.The chloride rejection was 50 times bet-ter with the former instrument than withthe latter.3 All data reported are the aver-age of at least two determinations, and 50mL of sample was analyzed.

ResultsInfluence on blanks. Four tests were

performed: one on deionized water (DI),one on DI water spiked with 100 mgCl/L, one on DI water spiked with 2 mgBr/L, and one on DI water spiked with100 mg Cl/L and 2 mg Br/L. The resultsin Table 1 show that the nitrate washremoved almost 100 percent of the chlo-ride, whereas approximately 98 percentof the bromide was removed. In gen-eral, these removals are high; however,the presence of a very large amount ofbromide in a sample could result in asignificant increase in the DOX blank,from 4 to 20 g Cl/L.

Influence of bromide ion. In deion-ized water. Because only about 5 percentof the groundwaters in the United Stateshave bromide ion concentrations >0.35mg/L,4 a second test was performed in

*TOX-10, COSA Instrument Co., Norwood, N.J. Dohrmann Div., Rosemount Analytical, Santa Clara,

Calif.

16

14

12

10

8

6

4

2

0

0 500 1,000 1,500 2,000

Bromide Ion Concentrationg/L

App

aren

t DO

Xg

Cl /

LFIGURE 1 Interference of bromide ion with DOX analysis in DI water

0 200 400 600 800 1,000

Bromide Ion Concentrationg/L

Appa

rent

DOX

g

Cl /

L

105

100

95

90

85

FIGURE 2 Interference of bromide ion with DOX analysis in thepresence of trichlorophenol

(C) 1995 American Water Works Association

AUGUST 1995 83

which DI water was spiked at four con-centrations of bromide ion: 0, 0.25,0.5, and 1.0 mg Br/L. The DOX datafrom this experiment was combinedwith the data from the DI + 2 mg Br/Lsample in Table 1 to produce Figure 1,in which the apparent DOX equals themeasured value minus that amountdetected in the DI blank water.

The slope of this line is 0.0072 gCl/L per g Br/L, with an r2 of0.960. This indicates a 98.4 percentremoval of the bromide interference over the rangetested, good agreement with the data in Table 1.

In the presence of trichlorophenol. To determinewhether similar results could be obtained if bromideion was present along with organic matter, various

concentrations of bromide ion were spiked into a DIwater solution of 92.5 mg Cl/L trichlorophenol, thecompound used to check the operation of the DOXprocedure during every test. The bromide concen-trations used varied from 0 to 1,000 g Br/L. The datain Figure 2 show the gradually greater interference ofbromide ion as its concentration increases. At 0 gBr/L, the calculated recovery of the trichlorophenolwas 97.4 percent, a typicalvalue for this laboratory.

The equation for the best-fit line in Figure 2 is DOX ing Cl/L = 0.0118 g Cl/L/gBr/L + 89.7 g Cl/L with anr 2 value of 0.989. This meansthat the slope of this line is1.6 times as great as that inFigure 1. This translates to97.3 percent removal of thebromide interference here ascompared with 98.4 percentin DI water, and 99.997 per-cent removal of chlorideinterference in DI water

(Table 1). The presence of the trichlorophenol onthe granular activated carbon may interfere to asmall extent with the ability of the nitrate wash toremove bromide. As a rule of thumb, every 1 mg/Lof bromide present in the water being tested will

add 12 g Cl/L to the DOXconcentration as deter-mined by method 5320 B.1

Influence of bromateor chlorate ion in deion-ized water. Two other inor-ganic ions, bromate andchlorate, which might bepresent in water, adsorb onthe GAC used in method5320 B1 and are reduced onthe GAC surface to bromide

and chloride. They were tested for interference in theDOX test. For each ion, a test similar to the one used togenerate Figure 1 was performed. As the data in Table2 show, these ions did not interfere with the DOX test.

Precision and accuracyTo assess the single operator precision of this deter-

mination in this laboratory, all of the data collected by

The presence of trichlorophenol on thegranular activated carbon may interfereto a small extent with the ability of thenitrate wash to remove bromide.

Tests to determine interferencesfrom bromide, bromate, and chlorate

ion were performed on a dissolvedorganic halogen analyzer.

Theoretical Measured InterferenceInterference Value Removed*

Sample DOX g Cl/L DOX g Cl/L percent

DI only 0 4.3 Not applicableDI + 100 mg Cl/L 100,000 7.58 99.997DI + 2 mg Br/L 887 19.7 98.264DI + 100 mg Cl/L

+ 2 mg Br/L 100,887 23.3 99.981

*Interference removed = (theoretical interference) (measured value 4.3)/(theoretical interference)(g Br) (35.5/80) = g Cl

TABLE 1 Interference of Cl and Br ion in deionized water with DOXdetermination

PHO

TO: M

ATT

MIL

AM

(C) 1995 American Water Works Association

the analyst were pooled. The mean blank value was 7.6 pg Cl-/L, with a coefficient of variation (o/mean x 100) of 14.1 percent for 53 samples. The mean con- centration for a 49.9-pg Cl-/L trichlorophenol stan- dard was 48.16 pg Cl-/L (96.54 percent recovery) with a coefficient of variation for recovery of 4.3 per- cent for 24 samples.

Discussion DOX is a water quality parameter that has had a

checkered history in the water supply industry. Some- times it has been popular because it is a single mea- surement group parameter that may be substituted for individual halogen-substituted DBP measure- ments. Its correlation to the molar sum of all mea- surable halogen-substituted DBPs has been demon- strated.5 On the other hand, because of its unknown character, demonstrating any health effects related to a given concentration has not been possible. In addi- tion, the inability to determine the accuracy of the method has been a valid criticism. Thus, at times it has lost favor.

DOX is to be measured in the upcoming data- gathering exercise related to the Information Collec- tion Rule. Considering the concentration of bromide ion in most waters, the interference reported here should not be a problem. In those waters sampled with > 0.5 mg/L of bromide, probably in the west and southwest,* the interference will be detectable, particularly if replicates are tested and averaged t improve the precision of the data. The extent of pos itive bias will be related to the concentration of bro mide ion in those samples.

l The nitrate wash step of method 5320 B1 is effective for removing bromate and chlorate ion.

l Based on work with trichlorophenol, in the pres- ence of organic matter, every milligram per litre of b.romide ion present will create a pos- itive interference of 12 pg Cl-/L using method 5320 B.l

Acknowledgment The authors thank Louis

A. Simms, staff chemist, Envi- ronmental Engineering Pro- gram, Department of Civil and Environmental Engi- neering, University of Hous- ton, for his invaluable help with the DOX instrumenta- tion; Stuart W. Krasner, Water Quality Division, the Metro-

politan Water District of Southern California, for his helpful review of the manuscript; the reviewers of the article for their suggestions for improvements; and the AWWA Research Foundation for its spon- sorship of the work, contract 803-93.

References 1.

2.

3.

4.

5.

Standard Methods for the Examination of Water and Wastewater. APHA, AWWA, and WEE Washing- ton, D.C. (18th ed., 1992) MUCKLE, S. Treatment of Spacecraft Humidity Condensate to Produce Potable Water. Masters thesis, Univ. of Houston, Texas (1990). RECKHOW, D.A. ET AL. The Determination of TOX in Water: A Comparative Study of Two Instru- ments. Zntl. Jour. Envir. Anal. Chem., 38:l (1990). AMY, G. Nationwide Survey of Bromide Ion Con- centrations in Drinking Water Sources, AWWA Res. Fdn., Denver, Colo. (in press). SINGER, P.C.; OBOLENSKY, A.; &- GREINER, A. Rela- tionships Among Disinfection By-products in Chlorinated Drinking Waters. Proc. 1992 WQTC, Toronto, Ont.

Symons is Cullen Distinguished Pro- fessor of Civil Engineering, University of Houston, Houston, TX 77204-4791. A graduate of Cornell University, Ithaca, N. Y (BCE), and of Massachu- set& Institute of Technology Cambridge (SM, ScD), Symons has been conduct-

ing research in the field of drinking water quality for more than 30 years. He has been a recipient of AWWAs Research Divi-

Conclusions sion Award and Publications Award (1970 and 1978) and is l The nitrate wash step of method 5320 B1 is not a member of the National Academy of Engineering. Rebecca

as effective for removing bromide ion as it is for Xia is a research assistant in the Department of Civil and removing chloride ion. Environmental Engineering, University of Houston.

84 JOURNAL AWWA (C) 1995 American Water Works Association

1991JanuaryJanuary 1991 CoverJanuary 1991 Table of ContentsLettersReflections - Are You Enjoying Life?Legislation/Regulation - Regulatory Status ReportLaw & WaterRoundtable - Environmentalism in the Water IndustryTheme Introduction - Activated CarbonEvaluating GAC for Trihalomethane ControlEvaluating the Costs of Packed-Tower Aeration and GAC for Controlling Selected OrganicsConference Summary: Practical Aspects of the Design and Use of GACUsing Powdered Activated Carbon: A Critical ReviewPredicting GAC Performance With Rapid Small-Scale Column Tests

FebruaryFebruary 1991 CoverFebruary 1991 Table of ContentsReflections - The Turning PointLegislation/Regulation - SDWA ReauthorizationViewpoint - Give the Customers What They WantLaw & WaterFace To Face - Office of Water ReorganizationTheme Introduction - Computers in the Water Industry"Network Analysis From Planning, Engineering, Operations and Management Perspectives"Expert Systems in Water treatment Plant OperationHardware Used for Analyzing Water Distribution Systems in OhioEffect of Natural Organic Matter on Biodegradation of a Recalcitrant Synthetic Organic ChemicalMicrobial Activity in GAC Filters at the Choisy-le-Roi Treatment PlantAccumulation and Adsorption Capacity of PAC in a Slury Recirculating Clarifier

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THM Formation by the Transfer of Active Chlorine From Monochloramine to PhloroacetophenoneBromoform and Idoform Formation potential Tests as Surrogates for THM Formation PotentialSee Letters-Letter #1-9/91-page 10

Comparing Ozonation and Membrane Separation for Color Removal and Disinfection By-product ControlInvestigating the Mechanism of Inactivation of Escherichia coli B.by Monochloramine

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Galvanic Stimulation of Corrosion on Lead-Tin Solder-Sweated JointsAnalyzing the Permeation of Organic Chemicals Through Plastic PipesCorrelation of Coliform Growth Response With Other Water Quality ParametersAssociation of Microorganisms With Surfaces in Distribution Systems

AugustAugust 1991 CoverAugust 1991 Table of ContentsLettersReflections - If the Shoe Hurts, Maybe It FitsLegislation/Regulation - Phase II Organic and Inorganic Contaminant RegulationsLaw & WaterRoundtable - Implementing the Lead RuleTheme Introduction - Capital FinancingEffective Revenue Bond Marketing - Put your Best Foot ForwardSee Letters-Letters #2-11/91-page 8

Reliability Analysis for Master planning of a Water SystemFinancing Capital ImprovementsContamination of Potable Water by Permeation of Plastic PipeSee Letters-Letter #2-2/92-page 4See also Letters-Letter #1-4/92-page 4

Effect of Initial Concentration of a SOC in Natural Water on Its Adsorption by Activated CarbonSee Letters-Letter #1-11/91-page 8

Removal of Soluble Manganese by Oxide-coated Filter Media: Sorption Rate and Removal Mechanism IssuesUsing Cobalt-Ultraviolet Spectrophotometry to Measure Hydrogen Peroxide Concentration in Organically Laden GroundwatersReview of Effects of Silver-Impregnated Carbon Filters on Microbial Water QualitySee Letters-Letter #1-3/92-page 4

SeptemberSeptember 1991 CoverSeptember 1991 Table of ContentsLetters"Reflections - Quo Vadis, AWWA?"Legislation/Regulation - Standardized Compliance MonitoringThe Federal Drinking Water Program: Friend or Foe?See Letters-Letter #1-1/92-page 4

Law & WaterTheme Introduction - Emerging TechnologiesMechanical Dewater of Alum Solids and Acidified Solids: An EvaluationLaboratory Comparison of DAF With Conventional TreatmentEvaluating Modifications to Slow Sand FiltersApplication of Gene Probe Technology to the Water Industry"The Haberer Process: Combinig Contact Flocculation, Filtration and PAC Adsorption"Pilot Testing the Haberer Process in the United StatesLow-Pressure Membrane Filtration for Removing Giardia and Microbial IndicatorsRemote Biological Monitoring in an Open Finished-Water Reservoir

OctoberOctober 1991 CoverOctober 1991 Table of ContentsReflections - Blunt Q's, Straight A'sLegislation/Regulation - Conservation LegislationLaw & WaterRoundtable - Conservation: An Expanding ViewTheme Introduction - ConservationThe Emerging Demand-Side Era in Water ManagementIntegrating Conservation and Water Master PlanningEstimating the Effects of Conservation on Deamand During DroughtsCalifornia Industries Cut Water UsePredicting the Formation of DBPs by the Simulated Distribution SystemPermeation of Polybutylene Pipe and Gasket Material by Organic ChemicalsSensitivity of the Asiatic Clam to Various Biocidal Control AgentsEffectiveness of Natural Polyelectrolytes in Water Treatment

NovemberNovember 1991 CoverNovember 1991 Table of ContentsLettersReflections - A Frightful FragilityLaw & WaterLegislation/Regulation - Fluoride regulation and Water FluoridationRoundtable - Public Relations Versus public InvolvementTheme Introduction - Health EffectsLessons Learned From the loma Prieta EarthquakeSee Letters-Letter #1-2/92-page 4

Prevention of Waterborne Cholera in the United StatesGiardiasis Risk From an Unfiltered, Protected Surface Water SourceProcess Selection for Potable Reuse Health Effects StudiesInactivation of Cell-Associated and Dispersed Hepatitis A Virus in WaterComparative Subchronic Toxicity of Chlorine and Monochloramine in the B6C3F1 MouseModeling the risk From Giardia and Viruses in Drinking WaterThe Effects of Soils on the Permeation of Plastic Pipes by Organic Chemicals

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1992JanuaryJanuary 1992 CoverJanuary 1992 Table of ContentsLettersReflections-A Four-Alarm Primacy FireLaw & WaterLegislation/Regulation-Congress debates lead legislationRoundtable-Will states keep primacyTheme intro-Membrane processes show promiseConvincing the public that drinking water is safeMaking Automated Systems Successful: How to Win the Hearts of Organizational SkepticsCreating a High-Performance Utility: The Link Between Culture and Organizational HealthCommittee report: membrane processes in potable water treatmentSOC removal in a membrane softening processRemoving Color From a Groundwater SourceMass Transport Considerations for Pressure-Driven Membrane ProcessesSelective Alum recovery from clarifier sludge

FebruaryFebruary 1992 CoverFebruary 1992 Table of ContentsLettersReflections-In Memory of Arch BecherViewpoint - Soviet, US Water Supply Problems Stem From Similar CausesLegislation/Regulation-USEPA Implements Stormwater RegulationsLaw & WaterFace To Face - Controlling Microbes Versus Disinfection By-productsSee Letters-Letter #1-11/92-page 4

Theme intro-Customer Service Goes High TechSee Letters-Letter #3-6/92-page 4

Expert Systems Show Promise for Customer InquiriesVoice Mail for the '90's: A Case StudyPerformance Chart Increases Crew ProductivityAssimilable Organic Carbon as an Indicator of Bacterial RegrowthEffects of particle Detachment in Granular-Media FiltrationIron and Manganese sequestration Facilities Using Sodium SilicateEvaluating GAC Adsorbers for the Removal of PCBs and ToxapheneRemoving Lead From Drinking Water With a Point-of-Use GAC Fixed-Bed Adsorber

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JuneJune 1992 CoverJune 1992 Table of ContentsLettersReflections - Getting Ready for Bad Weather"Viewpoint - Creativity, Flexibility Required in Response to Changes in the Workforce"Law & WaterLegislation/Regulation - OSHA - Our Savior Has ArrivedFace To Face - Facing the FutureTheme Introduction - Celebrating DiversitySee Letters-Letter #2-9/92-page 4

Workforce 2000: Coming Soon to Your WorkplaceWater Utilities Prepare for Workforce 2000Workforce Literacy in the Water Utility IndustryAccommodating the Biological Clock of Shift WorkersTransformation of NOM by Ozone and its Effect on Iron and Aluminum SolubilityMolecular Size Distributions of Dissolved Organic MatterComparing Plant-Scale Dual- and Mixed-Media FiltersTastes and Odors Associated With Chlorine DioxideAssessing the Quality of Flavor profile Analysis Data

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Water Audit Encourages Residents to Reduce ConsumptionNonresidential Water Conservation: A Good InvestmentPotential Impact of Water-Efficient plumbing Fixtures on Office Water ConsumptionThe (Relative) Insignificance of G in FlocculationLaboratory Evaluation of the Leaching of Organics From Fabric Material

NovemberNovember 1992 CoverNovember 1992 Table of ContentsLettersSee Letters-Letter #1-2/93-page 4

Reflections - Max Talks to the PublicLaw & WaterLegislation/Regulation - 'Reg Neg' Considered for D-DBP RuleRoundtableTheme Introduction - Trade-offs Key to D-DBP RuleSee Letters-Letter #2-6/93-page 4

How Strategic Is Your Planning?Optimizing Belt Filter Press Dewaterizing at the Skinner Filtration PlantDisinfection By-product Formation and Control by Ozonation and BiotreatmentRemoving Chlorite by the Addition of Ferrous IronCombining Methods for the Reduction of Oxychlorine Residuals in Drinking WaterDeveloping a Computer Model to Simulate DBP Formation During Water TreatmentUsing Ion Chromatography to Analyze Inorganic Disinfection By-productsComparison of the Microextraction Procedure and Method 552 for the Analysis of HAAs and ChlorophenolsTechnical Note: Comparing Predicted and Observed Concentrations of DBPs

DecemberDecember 1992 CoverDecember 1992 Table of ContentsLettersReflections - Reflections on WaterLaw & WaterLegislation/Regulation - Proposed Sulfate MCL ReconsideredTheme Introduction - Filtration: From Bacon to BlauAn Analysis of Low-Level Turbidity MeasurementsSelecting Particle Counters for Process monitoringExamining Relationships Between Particle Counts and Giardia, Crytosporidium and TurbiditySee Letters-Letter #1-3/93-page 4

Contact Filtration: Particle Size and RipeningPilot Study of the Effects of Ozone and PEROXONE on In-line Direct FiltrationHow Preoxidation Affects particle Removal During Clarification and FiltrationMF-PAC for Treating Waters Contaminated With Natural and Synthetic OrganicsDBP Control by Nanofiltration: Cost and Performance1992 Index

1993JanuaryJanuary 1993 CoverJanuary 1993 Table of ContentsLettersReflections - Of Time and the FutureLaw & WaterLegislation/Regulation - Influencing Regulations Through LitigationTheme Introductions - Bromated DBPsSee Letters-Letter #2-6/93-page 4

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Using a Conceptual Framework for Assessing Risks to Health From Microbes in Drinking WaterIncorporating Biologically Based Models Into Assessments of Risk From Chemical ContaminantsDeterminingHealth Risks Associated With Disinfectants and Disinfection By-products: Research NewsChemicals Versus Microbials in Drinking Water: A Decision Sciences PerspectiveResearch Agenda for Inorganic CompoundsImproving the Disinfection Detention Time of a Water Plant ClearwellEffect of Calcium in Field-Spent GACs on Pore Development During RegenerationModeling Hydrodynamics and Ozone Residual Distribution in a Pilot-Scale Ozone Bubble-Diffuser Contactor

AprilApril 1993 CoverApril 1993 Table of ContentsReflections - A Big Water Bang TheoryLaw & WaterLegislation/Regulation - Nitrate and Cancer: Is There a Link?Theme Introduction - Nitrate RemovalEmerging Standards For Water Utility ComputerizationComputer Applications in the Water IndustryThe Creative OrganizationIon Exchange for Nitrate RemovalRemoving Nitrate with a Methylotrophic Fluidized Bed: Technology and Operating PerformanceRemoving Nitrate with a Methylotrophic Fluidized Bed: Microbiological water quality

MayMay 1993 CoverMay 1993 Table of ContentsLetters"Reflections - Change, Pain and Section Progress"Law & WaterLegislation/Regulation - Involving the Public in Developing RegulationsRoundtable - Caring for WatershedsTheme Introduction - Biological Treatment: A Partner for Ozone?Investigation of the Regent Street Water Tower CollapseA Knowledge-Based Energy Management System for the Municipal Water IndustryTrends in Water Pricing: Results of Ernst & Young's National Rate SurveysTesting Biologically Active Filters for Removing Aldehydes Formed During OzonationFormation and Removal of Aldehydes in Plants That Use OzonationEffect of Ozone Dosage and Subsequent Biodegradation ofn Removal of DBP PrecursorsTesting a Coke Biofilter for the Pretreatment of Polluted Surface Water in TaiwanTesting Reinforced Concrete Structures for WatertightnessCommittee Report: Research Needs for Inorganic Contaminants

JuneJune 1993 CoverSee Letters-Letter #2-9/93-page 4

June 1993 Table of ContentsLettersReflections - A Quality ConversationViewpointLaw & WaterLegislation/Regulation - Tapping USEPA's Integrated Risk Information SystemFace To Face - On Quality, Public Involvement and ListeningTheme Introduction - Small Systems Need Creative ApproachSee Letters-Letter #2-10/93-page 4

A Cryptosporidiosis Outbreak in a Filtered-Water SupplyHow Will Small Water Systems Finance SDWA Compliance?Financing Assistance Available for Small Public Water SystemsDeveloping Models for Assessing the Financial Health of Small and Medium-Sized Water utilitiesIon exchange: A Cost-Effective Alternative for Reducing RadiumComposite Correction Program Optimizes Performance at Water PlantsUsing POE Techniques to Remove RadonInfluence of Bromide on Low-Pressure Membrane Filtration for Controlling DBPs in Surface WatersSampling and Enumeration of Zebra Mussel Veligers: Implications for Control

JulyJuly 1993 CoverJuly 1993 Table of ContentsReflections - Oh, Is That What You Meant?Law & WaterLegislation/Regulation - Utility Compliance: Status and OutlookRoundtable - Workplace DiversityTheme Introduction - Distribution SystemsTips for Saving Energy in Pumping OperationsSee Letters-Letter #1-11/93-page 4

Computer-Generated Pumping Schedules for Satisfying Operational ObjectivesIntegrating Hydraulic Modeling and SCADA Systems for System Planning and ControlUsing Computer Models to Determine the Effect of Storage on Water QualityAssessing the Effects of Storage Tank Design on Water QualtiyPlanning a Distribution System Flushing ProgramNitrification in a Distribution SystemInvestigating the Preferential Dissolution of Lead From solder ParticulatesExamining the Relationship Between Iron Corrosion and the Disinfection of Biofilm Bacteria

AugustAugust 1993 CoverAugust 1993 Table of ContentsReflections - The Mother Country's Shining ExampleViewpoint - California Consortium Finds ConsensusLaw & WaterLegislation/Regulation - Protecting the Public Against CryptosporidiumRoundtable - IRP: An Open Planning ProcessTheme Introduction - ConservationThe Energy Policy Act: Assessing Its Impact on UtiltiesIntegrating Conservation Targets Into Water Demand ProjectionsMarginal-Cost Pricing: Its Role in ConservationEvaluating the Effect of Residential Water Audits"The Social Acceptability of Water Conservation in Sprinfield, Ill."Evaluation of a Field Test Kit for Monitoring lead in Drinking WaterInvestigating the Effects of Chloramine on Elastomer DegradationAOC Associated with Oils for Lubricating Well PumpsUsing Coefficients to Predict Dynamic Flow Torque for Quarter-TurnValves

SeptemberSeptember 1993 CoverSeptember 1993 Table of ContentsLettersReflections - Who's in Charge of Happiness?Viewpoint - The Emperor Has No ClothesLaw & WaterLegislation/Regulation - Reg-Neg process Draws to a Close"Theme Introduction - Ther's a Will, But is There a Way?"Getting the Most From a Contract LaboratoryLaboratory Management: Facing the Challenges of the FutureQuality Assurance and Quality Control for Drinking Water LaboratoriesUSEPA Drinking Water Laboratory Certification ProgramEnumerating and Disinfecting Bacteria Associated With Particles Released From GAC Filter-AdsorbersSources of Chlorate Ion in US Drinking WaterControlling the Formation of Chlorate Ion in Liquid Hypochlorite FeedstocksThe Occurrence of DBPs in Utah Drinking WatersRemoving THMs From Drinking Water Using High-Energy Electron-Beam Irradiation

OctoberOctober 1993 CoverOctober 1993 Table of ContentsLettersReflections - Philosophers All, We AreLaw & WaterLegislation/Regulation - Information Collection Rule to Gather Critical DataTheme Introduction - Treatment Plant DesignWater Quality Improvement Plan for Greater VancouverThe Role of Residuals Disposal Laws in Treatment Plant DesignAir-Stripper Design and Costing Computer ProgramProbabilistic Evaluation of Packed-Tower Aeration Designs for VOC RemovalSee Letters-Letter #1-2/94-page 4

Using a Hydraulic model to Predict Hollow-Fiber UF PerformanceManganese Control During Ozonation of Water Containing Organic CompoundsAccelerated Testing of Copper CorrosionFactors Affecting Radium Removal Using Mixed Iron-Manganese OxidesInvestigating Filter performance as a Function of the Ratio of Filter Size to Media Size

NovemberNovember 1993 CoverNovember 1993 Table of ContentsLettersReflections - The Tie That Bind Us"Viewpoint - Wanted: Intuitive, Strategic Thinkers"Law & WaterLegislation/Regulation - D-DBP Rule to Set Tight StandardsRoundtable - Sharing Public Policy DecisionsTheme Introduction - A Chance for the 'Inner Adult' to ShinePublic Affairs Programs: The Critical Link to the PublicPublic Involvement in Austin's Rate StudyWorking With a Politically Active CommunitySurvey Says Water Utility Advisory Councils Are a SuccessMaking the Public a Partner in Project DevelopmentAnalyzing Disinfection Kinetics and Reactor Design: A Conceptual Approach Versus the SWTRRemoving Giardia and Cryptosporidium by Slow Sand FiltrationExamining the Impact of Aquifer Storage and Recovery on DBPsTable of Values of Most Probable Numbers: Ten Tubes, Three DilutionsSee Letters-Letter #3-4/94-page 4

DecemberDecember 1993 CoverDecember 1993 Table of ContentsReflections - On Keeping Bosses InformedLaw & WaterLegislation/Regulation - Strengthening the Surface Water Treatment RuleTheme Introduction - Refocusing on FiltrationAssessing Treatment Plant PerformanceTesting Direct Filtration for the Treatment of High-Turbidity WaterThe Performance and Microbiology of Ozone-Enhanced Biological FiltrationPredicting and Verifying TOC Removal by PAC in Pilot-Scale UF SystemsParticle Behavior in Deep-Bed Filtration: Part 1 - Ripening and BreakthroughParticle behavior in Deep-bed Filtration: Part 2 - Particle DetachmentParticle Removal and Head Loss Development in Biological Filters1993 Index

1994JanuaryJanuary 1994 CoverJanuary 1994 Table of ContentsReflections-A Message From the RomansViewpoint-Ensuring Water Quality in Urban EnvironmentsLaw & WaterLegislation/Regulation- Congress to Decide Fate of Radon StandardRoundtable-Customer service gains a footholdTheme intro- Storms and silver liningsOvercoming the flood: how midwestern utilities managed disasterSurviving the flood: teramwork pays off in Des MoinesWeathering the storm: water systems versus hurricanesEmergency preparedness and responseOrganonitrogen herbicides in the lower Kansas River basinEffects of ozonation on coagulation of NOM using polymer alone and polymer/netal salt mixtures"Examining the reactions between soluble iron, DOC, and alternative oxidants during conventional treatment"

FebruaryFebruary 1994 CoverFebruary 1994 Table of ContentsLettersReflections-Tips For SuccessLaw & WaterLegislation/Regulation-SDWAReauthorization Battle BeginsRoundtable-The competition for federal fundsTheme intro-Assessing the regulatory pictureThe current regulatory agenda: an updatePenalties for SDWA and CWA violationsCosts and benefits of current SDWA regulationsAre water rates becoming unaffordable?See Letters-Letter #2-6/94-page 4

Waterborne disease in the United States, 1991 and 1992See Letters-Letter #1-7/94-page 4

Determing the practical quantitation level for arsenicA volumetric method for assessing Giardia inactivationA survey of BOM in US drinking waters

MarchMarch 1994 CoverMarch 1994 Table of ContentsReflections-Can We Talk About It?Law & WaterFace to Face-A world view of water supplyTheme intro-Is privatization in the future for US water suppliers?Privatizing infrastructure options for municipal systemsBritish privatization: balancing needsPrivatization in England and WalesPrivatizing the Mexican water industryWater industry best practicesCompetitive Adsorption of VOCs and BOM: the role of molecular oxygenComparing two GACs for adsorption and biostabilization"Toxicological studies on MX, a disinfection by-product"

AprilApril 1994 CoverApril 1994 Table of ContentsLettersReflections-How to Carve a RoseLaw & WaterTheme intro-Removing radionuclidesManaging the financial condition of a utilitySupply storage in federal reservoirsWater conservation for Rhode Island lawnsImplications of discharging potable water in Southern CaliforniaModifying ion exchange for combined removal of uranium and radiumExhausting and regenerating resin for uranium removal

MayMay 1994 CoverMay 1994 Table of ContentsLettersReflections-Understanding the PressViewpoint-Principles of community outreachLaw & WaterLegislation/Regulation-A Look At The Federal Drinking Water Revolving Loan Fund ProposalsRoundtable-Training for the next centuryTheme intro-Small systems and big decisionsStrategic planning for SDWA compliance in small systemsSee Letters-Letter #1-10/94-page 4

Small systems and SDWA reauthorizationMonitoring waivers for Phase II and Phase V regs Dual-stage filtration proves cost- effectiveCommercial labs: how accurate are they?Monitoring the effect of zebra mussels on raw-water intakes

JuneJune 1994 CoverJune 1994 Table of ContentsLettersReflections-The Fearless CrusaderLaw & WaterLegislation/Regulation-Information Collection Rule DelayedFace to face-Taking the initiativeTheme intro- Disinfection By-products: Strengthening the DatabaseQuality degradation: implications for DBP formationPrecursor control in waters containing bromideSee Letters-Letter #3-9/94-page 4

BOM removal during biological treatment: a first-order modelBromide's effect on DBP formation, speciation, and control: part 1, ozonationSee Letters-Letter #3-9/94-page 4

Using RSSCTs to predict field-scale GAC control of DBP formationEvaluating surrogates for disinfection by-products

JulyJuly 1994 CoverJuly 1994 Table of ContentsLettersReflections-Who's Winning the Game?Law & WaterLegislation/Regulation-Inside Senate Bill 2019Theme intro-Managing Distribution Systems: Theory and PracticeSCADA trends and integration perspectivesKnowledge-based systems for maintenanceHead loss testing in transmission mainsStainless-steel pipingSee Letters-Letter #1-10/94-page 4

The pitting corrosion of copperElectrochemical nature of lead contamination

AugustAugust 1994 CoverAugust 1994 Table of ContentsLettersReflections-Keeping the Best and BrightestLaw & WaterLegislation/Regulation-A Preview of the New Sulfate ProposalTheme intro-New Twists to Old TreatmentsCost-effectiveness of SDWA regulationsEffect of iron oxide coating on sand filtrationEvaluating buoyant coarse media flocculationSynthetic adsorbent versus GAC for TCE removalRemoving EDB with GAC filtersLaboratory-scale testing of a continuous CLAS process

SeptemberSeptember 1994 CoverSeptember 1994 Table of ContentsLettersLegislation/Regulation-Crafting a New Arsenic RuleTheme intro-In Search of an Arsenic MCLArsenic occurrence: USEPA seeks clearer pictureHealth implications of arsenic in drinking waterChemistry of arsenic removal during coagulation and Fe-Mn oxidationEnhanced coagulation for arsenic removalGAC adsorption of intermittently loaded pesticides

OctoberOctober 1994 CoverOctober 1994 Table of ContentsLettersReflections-Advice From a Roman PoetLaw & WaterLegislation/Regulation-Environmental and Related Federal LawsRoundtable-Choosing Best PracticesTheme intro-Do everything as well as you can"TQM in OREM, Utah responsive agency, satisfied customers"Performance improvement: a challenge for water utilitiesDeveloping rates with citizen involvementWater affordability and alternatives to service disconnectionTraining improves management effectivenessAlternative strategies for removing bromate

NovemberNovember 1994 CoverNovember 1994 Table of ContentsLettersReflections-On TV Reporting and ParasitesLaw & WaterLegislation/Regulation-Disposal of Radioactive ResidualsRoundtable-Regulatory Compliance CostsTheme intro-Recycling and reuse: are they the answer?Network modeling: advances at a major British utility See Letters-Letter #2-2/95-page 4See Letters-Letter #1-7/95-page 4

Development fees: a legislative historyWaste stream recycling: its effect on water qualityLong-term effects of sludge application to landEffects of alum sludge on plant growthThe effect of shear on the dewatering of water treatment residuals

DecemberDecember 1994 CoverDecember 1994 Table of ContentsReflections-Opening the CEO's BoxViewpoint-Protecting Consumers From CryptosporidiosisLaw & WaterTheme intro-New Uses for Membrane TechnologyHydraulic transients cause low-pressure problemsCost estimates for membrane filtration and conventional treatmentMembrane plants in North AmericaSelecting membranes for removing NOM and DBP precursorsEffect of selected anions on copper corrosion rates