DBP Control: Update on WaterRF and Mid-Sized Utilities

Transcription

1 DBP Control: Update on WaterRF 4427 A Decision Support Tool for Small and Mid-Sized Utilities 2012 Water Research Foundation. ALL RIGHTS RESERVED.

2 Stage 2 D/DBP Rule Promulgated in January 2006 IDSE completed for all systems Compliance monitoring begins: April 2012 for systems >100,000 October 2012 for systems 50, ,00 October 2013 for systems <50, Water Research Foundation. ALL RIGHTS RESERVED.

3 Goal of Project To develop a manual and web tool on DBP formation and control Definitive Understandable Results-oriented To help small utilities determine the options and steps most applicable to their needs 2012 Water Research Foundation. ALL RIGHTS RESERVED.

4 Presentation Outline Professor David Reckhow: Overview of DBPs Professor Yeufeng Xie: Stage 2 D/DBP Regulations Dr. William Becker: Approach to DBP Compliance Tool Dr. Erik Rosenfeldt: DBP Compliance Tool Overview 2012 Water Research Foundation. ALL RIGHTS RESERVED.

5 Tuesday, October 2, 2012 Webcast Overview of DBPs WaterRF Project #4427 David A. Reckhow Professor, University of Massachusetts 1

6 Formation of DBPs Reaction of disinfectants with natural organic matter (NOM) Chlorine or Chloramines Natural Organic Matter Disinfection Byproducts 2

7 The first, and currently regulated DBPs The THMs Cl Cl C H Cl Br Br Br Cl C H Br C H Br C H Cl Cl Br Chloroform Bromodichloromethane Chlorodibromomethane Bromoform The HAAs Tri-HAAs Cl Cl C COOH Cl Br Cl C COOH Cl Br Br C COOH Cl Br Br C COOH Br Di-HAAs Trichloroacetic Bromodichloroacetic Chlorodibromoacetic Tribromoacetic Acid Acid Acid Acid (TCAA) Cl Br Br H C COOH H C COOH H C COOH Cl Cl Br 3 HAA5 only Dichloroacetic Bromochloroacetic Dibromoacetic Acid Acid Acid (DCAA)

8 The DBP Iceberg THMs, THAAs DHAAs ICR Compounds 50 MWDSC DBPs ~700 Known DBPs Halogenated Compounds Non-halogenated Compounds

9 Other DBPs Many others formed but not regulated Total organic Halide (TOX): the total amount of organic chlorine and organic bromine DBPs Hl Haloacetonitriles itil Halopropanones Halonitromethanes (including chloropicrin) Haloaldehydes (including chloral hydrate) Halobenzoquinones Non-TOX byproducts Probably the Nitrosamines (including NDMA) next to be regulated 5

10 Factors Affecting DBP Formation Time ph Chlorine Dose Temperature Bromide Ammonia addition Biodegradation d Reactions with pipe walls & attached materials 6

11 Time mg/l chlorine dose ph o C Major 900 Byproducts Aquatic NOM TO OX Concentrat tion ( g/l) (redrawn from: Reckhow & Singer, 1984; JAWWA 76: ) TCAA TOX TTHM tration ( g/l) HAA Concen THM, 200 DCAA Time (hrs)

12 Dose & TOC Near linear increase until residual exists Then relatively small increases in THMs and HAAs with increasing dose Higher TOC and higher precursor levels mean more DBPs TTHM Concentra ation ( g/ L) Laboratory Treated Waters 1989 Start of Lasting Residual Connecticut cut River Hadley, MA High Cl 2 Demand Finished Water New England Med Cl 2 Demand Goose Creek 50 Panama, NY 0 Low Cl 2 Demand Chlorine Dose (mg/l)

13 ph Affects 1400 Range of Interest 1200 THMs increase with increasing i ph Most decrease n ( g/l) Con ncentratio 1000 TOX TTHM Redrawn from: Reckhow & Singer, 1984; JAWWA 76: (4.2 mg/l TOC, 3 days, 20 mg/l dose, 20 o C) TCAA DCAA ph

14 Effect of Bromide No Bromide HOCl HOCl HOCl B A C Cl C H Cl Cl H D HOCl E HOCl Cl C Br Cl H F HOCl Br C Br Cl H 10 HOCl Br HOBr Cl k Br C Br Br

15 Impact of Bromide on THM Formation CHCl 3 Data from: Minear & Bird, hours, ph mg/l Chlorine Dose 1 mg/l Humic Acid Percent of TTHM CHBrCl 2 CHBr 2 Cl CHBr Bromide Concentration (mg/l)

16 Case Study: Impact of time & chlorine dose THMs Almost Always increase with time, ph and chlorine dose Tot tal Trihalom methanes ( g/l) Loss of Residual Chlorine Dose 2.5 mg/l 5 mg/l 10 mg/l Time (hrs)

17 Chloramination Slows THM & HAA THM model based on actual treated water 13 TOC = 2.5 mg/l SUVA = 2.0 ph 8 20C 1.2 mg/l free Cl 2 dose Chloramination (3 mg/l; 4 mg- Cl 2 /mg-n) Concentratio on ( g/l) Addition of ammonia at 2, 4 or 8 hr Formation 20 All Free Cl 2 2 hr Free Cl hr Free Cl 2 8 hr Free Cl Time (hrs)

18 14 DBP Control prior to Distribution Source water management Sl Selection of sources, watershed hd management Precursor Removal (mostly NOM) Coagulation (& settling/filtration) ti Biological treatment (w & w/o pre-oxidation) Adsorption Precursor Modification Oxidation Other process changes Dl Delayed point it of chlorination DBP Removal

19 DBP Control after Point of Entry Management of Water Age Avoiding high Cl 2 doses Booster chlorination Blending from multiple POEs Use of Alternative Final Disinfectants Chlorine Dioxide: limits on dose Chloramines: many secondary issues Forms less THMs, HAAs, but more nitrosamines and some others Localized Treatment 15

20 Conclusions Regulated DBPs (THMs & HAAs) tend to increase with time, and chlorine dose Non-regulated and emerging DBPs may not Increasing ph usually results in lower DBP levelsl Exception: THMs! Many options for controlling DBPs Precursor removal is most widely practiced Chloramines are also widely used They can increase some DBPs that may be subject to future regulation (e.g., nitrosamines) 16

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22 Stage 2 D/DBP Rule Yuefeng Xie, Ph.D., P.E., DEE Professor of Environmental Engineering

23 TCAA versus TCA Both terms stand for trichloroacetic ihl i acid A carcinogen versus a skin peel chemical Cancer or 10 years younger looking skin EPA/AWWA versus FDA/American Society of Plastic Surgeons. By a professor/engineer versus a makeup artist 60 ppb (ug/l) in DW versus 20% in DW $24 for 5 g (99%) from Aldrich versus $23.99 for 1 oz (20%) from Amazon online

24 D/DBP Rule: Stage 2 Overview Designed to reduce peak occurrences in distribution systems by changing compliance monitoring (LRAA) One-year IDSE to select site-specific ifi optimal sample points to capture peaks and limit THM/HAA variations Locational Running Annual Average (LRAA) MCLs: 80/60 - for each monitoring location 3 Monitoring for Large SW systems (> 10,000) quarterly sampling at least one quarterly sample at peak month 4-20 DS locations determined by initial distribution system evaluation (IDSE) and stage 1 locations 2-8 at high THM sites, and 1-7 at high HAA sites Monitoring for small SW systems (< 10,000) 2 locations as determined by IDSE 3

25 D/DBP Rule: Stage 2 (cont.) Compliance schedule 80 ppb TTHM & 60 ppb HAA5, based on locational running annual average (LRAA) at: New sampling sites to be identified through initial distribution system evaluations (IDSEs) to begin 6¼, 6¾ and 7 ¾ years after promulgation (+ 2) Apr 2012 (>100K) Oct 2012 (50-100K) Oct 2013 (<50K) 4 4

26 5 Stage 2: Compliance Population-based monitoring Surface Water Systems (Sub-part H) Surface Water DS Monitoring Locations Monitoring System Size Stage 1 Compliance Highest TTHM Highest HAA5 Total Frequency < Yearly 500-3, Quarterly 3,301-9, Quarterly 10,000-49, Quarterly 50, , Quarterly 250, , Quarterly 1M - <5M Quarterly 5M Quarterly 5

27 Stage 2: Compliance Population-based monitoring i Groundwater Systems Groundwater System Size Stage 1 Compliance DS Monitoring Locations Highest TTHM Highest HAA5 Total Monitoring Frequency < Yearly 500-9, Yearly 10,000-99, Quarterly 100, , Quarterly 500, Quarterly 6 6

28 Stage 1 versus Stage 2 (US EPA)

29 RAA versus LRAA

30 Example (HAAs)

31 Operational Evaluation Levels

32 Operational Evaluation Levels

33 Operational Evaluation Level What s covered in an Operational Evaluation Treatment & distribution practices that might have caused dthe exceedance Storage tank operations, excess storage capacity distribution system flushing, source water quality, treatment processes & operation When does this provision start?: As soon as the 3 rd quarter of Stage 2 compliance data are received i.e., as early as July 2014 for small utilities

34 Operational Evaluation Level Provision for limited OE if exceedance is due to A localized phenomenon or of known cause EPA Guidance Manual ft_guide_stage2_operationalevaluation.pdf _ g _ p 13 13

35 EPA Guidance Manuals Initial Distribution System Evaluation (IDSE) Guidance Manual Operational Evaluation Guidance Manual Consecutive Systems Guidance Manual Small Systems (SBREFA) Guidance Manual Simultaneous Compliance Guidance Manual

36 DBP Control NOM + Chlorine DBPs NOM Enhanced coagulation Chlorine Alternative disinfectants DBPs Removal 15

37 The Magic of TCA

38 DBP Control: Update on WaterRF 4427 A Decision Support Tool for Small and Mid-Sized Utilities William Becker, Ph.D., P.E. National Water Practice Leader Erik Rosenfeldt, Ph.D., P.E. Deb Dryer, Ph.D., Columbia University David Reckhow, Ph.D., P.E. UMASS Yuefeng Xi, Ph.D., P.E. Penn State Harrisburg File location name here.p ppt Djanette Khiari, Ph.D. Water Research Foundation

39 Goal of Project 2 To develop a manual and web tool on DBP formation and control Definitive e Understandable Results-oriented To help small utilities determine the options and steps most applicable to their needs

40 Presentation Outline 3 Approach Control of DBPs Compliance Tool Introduction

41 DBP Formation 4 NOM = natural organic matter HOCl + NOM Reduce these to minimize formation Chlorinated Organics THMs HAAs f [chlorine dose, NOM concentration, ph, temperature, time]

42 DBP Control: 5 Understand your water system Source Treatment Plant Distribution System

43 Options 6 DBPs = f [chlorine dose, TOC, ph, temperature, time] Parameter Source Water Treatment Distribution TOC Chlorine Time Temperature ph : Locations where parameters can be affected

44 DBP Control 7 f [chlorine dose, NOM concentration ti (and type), ph, temperature, t time] Control options: Use alternative source water Alter chlorination scheme Reduce chlorine dose Move point of chlorination to downstream of NOM removal Optimize DOC removal (e.g., improved mixing, coagulation chemistry, ph) Use alternative disinfectants Use of ozone, chlorine dioxide typically results in lower concentrations of DBPs UV disinfection Chloramines Optimize distribution system operations Reduce travel time in distribution system Change ph Remove DBPs after formation Aeration for THMs; GAC for HAAs

45 Source Control 8 Parameter Source Water Treatment Distribution TOC Chlorine Time Temperature ph : Locations where parameters can be affected

46 Source Strategies 9 If flexibility exists, consider: Changing source water seasonally Blending water sources Modifying reservoir filling operations

47 Changing Sources Seasonally 10 Goal Use the best source water quality during periods of high DBPs Requires significant infrastructure to be in place Potentially simple to complicated rules Examples: Reservoir/River Sources Surface / Ground Water Sources Multiple Intakes Algae Elev vation Temperature Low DO, Mn 2+??

48 Treatment Control 11 Parameter Source Water Treatment Distribution TOC Chlorine Time Temperature ph : Locations where parameters can be affected

49 Treatment Strategies for Stage 2 12 System Optimization Process Changes Advanced TOC Removal Cost Optimize Free Chlorine Disinfection Implement Enhanced Coagulation Change Coagulant Change Secondary Disinfectant Change Primary Disinfectant MIEX or Post-Filter GAC Contactors Membranes Strategy

50 Treatment Options: 13 Optimize Free Chlorine Free chlorine usage If possible, reduce or eliminate raw water chlorination Not at the expense of required CT If manganese is an issue, need to consider alternative pre-filter oxidant Understand CT requirements Chlorine doses leaving the plant Evaluate seasonal trends at minimum residual locations May be able to reduce applied chlorine dose in the winter to maintain residual. However, may need higher dose in the winter to meet CT

51 Treatment Options: 14 Optimize Coagulation Target TOC as well as turbidity Turbidity (NTU) Turbidity UV 2.3 NTU 11.2 NTU Ferric Dose (mg/l) UV Absorban nce (cm 1 )

52 Treatment Options: 15 Change Coagulants Coagulation changes to target TOC reduction Change coagulant PACl effective for particle removal Alum can be effective for particle and TOC reduction Limited ph reduction before Al solubility issues Ferric can be effective for particle and TOC reduction ph can be suppressed further than alum or PACl Add acid Lowering ph improves removal of TOC Alum and ferric are acidic, so ph will be lowered compared to PACl Be wary of alkalinity (needed for floc formation)

53 Treatment Options: 16 Change Disinfectants Alternative disinfectants do not form chlorinated DBPs ClO 2, Ozone, UV Non-chlorine disinfectants more effective against Cryptosporidium and Giardia In addition to cost Ozone can create bromate (MCL = 10 g/l) if you have bromide in your raw water Chlorine dioxide forms chlorite (MCL = 1.0mg/L) No residual disinfectant for the distribution system

54 Treatment Options: 17 Advanced TOC Removal Activated Carbon (GAC and PAC) Membranes MIEX

55 Distribution System 18 Parameter Source Water Treatment Distribution TOC Chlorine Time Temperature ph : Locations where parameters can be affected

56 Formation in the Distribution System? Measu ured TTHM (pp pb) Predicted Water Age (hours)

57 Localized or Widespread? 20 IDSE scrutiny has improved understanding of DBPs in Distribution Systems Problem areas highlight extent of elevated DBPs

58 Widespread Issues 21 Consider system-wide improvements Reduce chlorine levels into the DS Chloramines for residual

59 Widespread Issues 22 Consider system-wide improvements Reducing water age Reduce amount of storage (within safe limits) Consider dead-ends Is the storage in the best place?

60 Localized Issues: Minimize System Water Age Periodic flushing programs Done to eliminate or reduce hot spots Completed in conjunction with distribution system model approximating water age 23

61 Localized Issues 24 Localized Treatment Treatment may be an option? Mixing Tank Aeration GAC at tank outlet

62 Guidance Manual and web tool introduction 1

63 The crux 2 The Manual and web tool provide guidance for complying with Stage 2. The goal of the materials is to help utilities: Evaluate potential compliance relative to a goal Understand DBP reduction strategies Compare DBP reduction strategies using system specific information to estimate: Percent DBP reductions Cost

64 Methodology Overview 3 Data Assembly Evaluate Compliance Status and Determine Required Reduction Compliance Goal Easily Achieved Compliance Goal Compliance Goal not Met or Questionable Source, Treatment, Distribution Strategies Interactive Road Map to Compliance

65 Step 1: Assemble Data and Determine Goals 4 Data Assembly Evaluate Compliance Status and Determine Required Reduction Compliance Goal Easily Achieved Compliance Goal Compliance Goal not Met or Questionable Source, Treatment, Distribution Strategies Interactive Road Map to Compliance

66 Available Data Determine Data Available: DBPs: Stage 1 Quarterlysinceat at least 2002 (for larger systems) IDSE (between 2006 and 2009) What type of IDSE performed? Standard Monitoring Hydraulic Model System Specific Study Data used to satisfy IDSE 1 6 measurements per sample site for 1 year Additional / Non Compliance Continued monitoring of IDSE sites or early monitoring of selected compliance sites

67 Other Useful Data Population Served TOC Raw water alkalinity Raw Water Bromide Finished i water ph Advanced TOC characterization UV 254 and/or SUVA Chlorine usage data Total chlorine usage in plant Residual chlorine levels Distribution System Locational Water Age (if known) Seasonal Demand System Storage Capacity

68 Manual Data Entry 7 Com mpliance Sites Jan March May July Sept Nov Site type IDSE high TTHM IDSE high HAA IDSE high TTHM Jan April July Oct Stage Average RT Site 1 Stage Average RT Site 2 With data that look like this, Process and calculate to this Com mpliance Sites Q1 Q2 Q3 Q4 LRAA OEL 1 OEL 2 IDSE IDSE IDSE Stage Site 1 Stage Site 2

69 Entering Data into the Webtool 8 First, some information about compliance locations: Followed by data entry

70 More Data Entry 9

71 Choosing Compliance Goals Depends on your level of comfort with risk 1. Maintain LRAAs below the MCLs 80 g/l for TTHMs 60 g/l for HAA5 Mandatory Minimum 2. Maintain LRAAs below 80% of the MCL 64 g/l for TTHMs 48 g/l for HAA5 3. Prevent any Operational Evaluations 4. Eliminate all individual sample concentrations > MCL

72 Step 2: Compliance Calculations 11 Data Assembly Evaluate Compliance Status and Determine Required Reduction Compliance Goal Easily Achieved Compliance Goal Compliance Goal not Met or Questionable Source, Treatment, Distribution Strategies Interactive Road Map to Compliance

73 Analyzing the data - IDSE 12 Complian nce Sites Other Sites Jan March May July Sept Nov LRAA OEL1 OEL2 "Q1" "Q2" "Q3" "Q4" Site type Q1 Q3 Q2 Q4 IDSE high TTHM IDSE high HAA IDSE high TTHM Jan April July Oct Stage Average RT Site 1 Jan March May July Sept Nov IDSE Entry point IDSE high HAA IDSE high TTHM IDSE Average RT IDSE Average RT Jan April July Oct Stage Average RT Site 2 Stage Max RT Site 3 (high THM) Stage Average RT Site 4 LRAA > MCL LRAA > 80% of MCL OEL > MCL Any Value > MCL

74 Contextualizing the IDSE Stage 1 Locational Running Annual Average Historical Record Stage 1 TTHM Historical Record Stage 1 HAA5 Historical Record TT HM ( g/l) Stage 1 1 Stage 1 2 Stage 1 3 Stage 1 4 Stage 1 5 HAA5 ( g/l) Stage 1 1 Stage 1 2 Stage 1 3 Stage 1 4 Stage O 05 A 06 O 06 A 07 O 07 A 08 O 08 A 09 O 09 0 O 05 A 06 O 06 A 07 O 07 A 08 O 08 A 09 O 09 Calculate Worst Case Factor and Apply to the IDSE Data

75 Summary of analysis 14 TTHM HAA5 TTHM ( g/l) HAA5 ( g/l) Compliance Goal Description # of Sites Design Percent Exceeding Goal Reduction 1 LRAA < MCL 2 7% 2 LRAA < 80% MCL 9 25% 3 OEL < MCL 3 16% 4 No samples > MCL 8 35%

76 Step 3: Strategies Assessment 15 Data Assembly Evaluate Compliance Status and Determine Required Reduction Compliance Goal Easily Achieved Compliance Goal Compliance Goal not Met or Questionable Source, Treatment, Distribution Strategies Interactive Road Map to Compliance

77 Strategies Considered 16 Source Treatment Distribution ib i Source Change Source Blending Reservoir Management Source Management Purchase Water Point of Chlorination Optimize Chlorine Dose Optimize PAC Optimize Coagulation for TOC Change Coagulation PAC Addition Change Primary Disinfection Advanced TOC removal GAC Advanced TOC removal MIEX Membranes Optimize DS Chlorination Change Secondary disinfection Booster Chlorination Optimize Storage Operation Tank THM Stripping Lessen Storage Volume System Flushing

78 Determining Impact of 17 Strategies Each Strategy linked to an optimum DBP reduction Users will answer a series of questions about their systems to hone in on actual DBP reduction potential Cost curves for each strategy are also linked to questionnaire responses

79 Strategy Costs and 18 Performance Summary

80 Example: 19 Treatment strategy 1 (T1): Raw water chlorination Contributes significantly to in-plant formation of DBPs Moving chlorination ato to after TOC removal by coagulation and sedimentation can reduce DBPs Complicating Factors: Achieving CT Iron and Manganese removal, algae, etc.

81 Contextual Questions 20

82 Outcome 1: Year Round Raw 21 Water Chlorination

83 Cost Information Year Round 22 Raw Water Chlorination Needs new contact time, by addition of clearwell tankage Input plant size, time required (ie, 4 MGD (2780 gpm), 30 minutes required) Need 2780 gal/min x 30 min = 83,000 gal storage (0.083 MG) Cost = x = $280,000 Cost ($) Clear Water Storage (McGivney and Kawamura) y = x R² = Tank Size (MG)

84 Updated summary worksheet ,000 0

85 Step 4: Road Map to Compliance 24 Data Assembly Evaluate Compliance Status and Determine Required Reduction Compliance Goal Easily Achieved Compliance Goal Compliance Goal not Met or Questionable Source, Treatment, Distribution Strategies Interactive Road Map to Compliance

86 Ultimate Output - Manual 25 Can be easily transferred to Excel or other programs for analysis Alternatively,

87 Ultimate Output - Webtool 26 Goal DBP Reduction: 17% % DBP Reduction Capital Cost ($) Annual Op. Cost ($) Source Option 1: Change 40% Reduction CapX:$ 30,000,000 OpX: $850,000 Option 2: Blending 15% Reduction CapX: $ 100,000 OpX: $ 600,000 Option 5: Purchase 8% Reduction CapX: $0 OpX: $ 780,000 Treatment Option 1: Raw Chlorination 9 % Reduction CapX: $ 100,000 OpX: $ 0 Option 7: Alt. Disinfection 5 % Reduction Cap X $ 2,100,000 OpX: $ 100,000 Option 4: Optimize Coagulation 3 % Reduction CapX: $ 0 OpX: $ 50,000 Option 8: GAC 30% Reduction Cap X: $ 6,500,000 OpX: $ 400,000 Option 5: Change Coagulation 11 % Reduction Cap X: $ 1,300,000 Op X: $ 72,000 12% $100,000 $ 50,000 Option 10: RO/NF Membranes 60% Reduction CapX $ 12,000,000 OpX: 450,000 Distribution Option 1: Optimize DS Chlorine 4 % Reduction CapX: $ 0 OpX: $ 0 Option 2: Chloramines 40 % Reduction CapX: $ 1,800,000 OpX: $ 95,000 Option 4: Flushing 5 % Reduction CapX: $ 30,000 OpX: $ 240,000 9 % $ 30,000 $ 240,000 Total 21 % $ 130,000 $ 290,000

88 Ultimate Output - Webtool 27 Goal DBP Reduction: 28% % DBP Reduction Capital Cost ($) Annual Op. Cost ($) Source Option 1: Change 40% Reduction CapX:$ 30,000,000 OpX: $850,000 Option 2: Blending 15% Reduction CapX: $ 100,000 OpX: $ 600,000 Option 5: Purchase 8% Reduction CapX: $0 OpX: $ 780,000 Treatment Option 1: Raw Chlorination 9 % Reduction CapX: $ 100,000 OpX: $ 0 Option 7: Alt. Disinfection 5 % Reduction Cap X $ 2,100,000 OpX: $ 100,000 Option 4: Optimize Coagulation 3 % Reduction CapX: $ 0 OpX: $ 50,000 Option 8: GAC 30% Reduction Cap X: $ 6,500,000 OpX: $ 400,000 Option 5: Change Coagulation 11 % Reduction Cap X: $ 1,300,000 Op X: $ 72,000 20% $1,400,000 $ 72,000 Option 10: RO/NF Membranes 60% Reduction CapX $ 12,000,000 OpX: 450,000 Distribution Option 1: Optimize DS Chlorine 4 % Reduction CapX: $ 0 OpX: $ 0 Option 2: Chloramines 40 % Reduction CapX: $ 1,800,000 OpX: $ 95,000 Option 4: Flushing 5 % Reduction CapX: $ 30,000 OpX: $ 240, % $ $ 1,800,000 30,000 $ 240,000 95,000 Total % $1,430,000 $ 1,800,000 $ 290,000 95,000

89 Summary 28 The Stage 2 D/DBP Rule compliance dates are 1 year away for small and mid-size utilities There is a huge body of knowledge available for utilities and consultants to use in developing solutions The purpose of this project is to assemble that information into an easy to use tool to help small and mid-size utilities comply with the rule

90 Summary (cont.) 29 Approaches to reduce DBPs target formation factors Source, treatment, and distribution strategies Need to understand your data to assess compliance situation Need to understand control options to implement the most cost effective solution for your particular utility. The new WaterRF and Hazen and Sawyer DBP Compliance Guidance Manual and Tool will provide assistance

91 Thank You! 30 Djanette Khiari Bill Becker enandsa er com Erik Rosenfeldt Dave Reckhow Yuefeng Xie

92 Questions?

93 Foundation Resources 2677: Disinfection By Product Formation and Control During Chloramination 2940: Long Term Effects of Disinfection Changes on Water Quality 3026: Evaluation of Disinfection Practices for DBP and Precursor Occurrence in ConsecutiveSystems 3103: Localized DBP Treatment Evaluation Model And User s Manual 3115: Decision Tool to Help Utilities Develop Simultaneous Compliance Strategies

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