Advanced Technologies for Attaining and Maintaining DBP Compliance 95TH Annual Conference | November 2015 | Raleigh Convention Center, Raleigh, NC Scott Alpert, PE, PhD Allison Reinert, EIT

Outline Background Case Study 1 Case Study 2 Conclusions

Background Stage 2 D/DBP Rule TTHMs Chloroform Dichlorobromomethane Dibromochloromethane Bromoform HAA5 Monochloroacetic Acid Dichloroacetic Acid Trichloroacetic Acid Monobromoacetic Acid Dibromoacetic Acid DBPs 4 Additional HAAs Not Currently Regulated

Background A Stage 3 DBP regulation may be forthcoming DBPs A Stage 3 DBP regulation may be forthcoming 6 year review of the current D/DBP rules in 2016

“Stage 3” DBP Regulations May Go Beyond TTHMs and HAA5 Background DBPs “Stage 3” DBP Regulations May Go Beyond TTHMs and HAA5

Eastern North Carolina 35 MGD WTP Case Study 1 Eastern North Carolina 35 MGD WTP

Case Study 1 35 MGD run of river WTP The Problem 35 MGD run of river WTP Ozone, super-Ps, BAC, UV, free chlorine Increased bromide in source water, increased TOC concentrations during extreme weather conditions

DBP Compliance Case Study 1 Post Treatment Aeration Manage Water Age The Solution DBP Compliance Online THM Analyzers Manage Water Age Post Treatment Aeration

Case Study 1 The Solution

Online THM Analyzer Results 4 months of data collected Several days of abnormal results (high and low results) Sample carryover after recalibration or check standard Power failures, surges at the facility Influent sample flow 2,558 independent measurements over the 4 months Only 5.3% were abnormal (138 independent measurements) If we exclude when the influent sample flow was accidentally valved off only 1.9% were abnormal (49 independent measurements)

Online THM Analyzer Results Parameter Sampling Interval Average Min Max Raw TOC (mg/L) Daily 7.2 4.4 12.3 CFE TOC (mg/L) 2.4 1.6 3.7 Raw UV254 0.27 0.16 0.43 Finished Prior UV254 0.02 0.001 0.04 Pre Ozone (ppd) 402 165 831 Intermediate Ozone (ppd) 169 70 333 Raw Temperature (°C) 22.9 13.7 28.2 Finished Prior Chlorine (ppd) 196 104 325

Previously Published Models TTHM = 10-1.385*TOC1.098*Cl20.152*Br0.068*Temp0.609*pH1.601*Time0.263

Comprehensive Model Fluorescence Excitation Emission Matrices Coupled with Principal Component Analysis

Comprehensive Model

Post Treatment Aeration Floating aerators installed in two elevated tanks to help high water age areas of distribution system

Post Treatment Aeration Elevated Tank

Piedmont North Carolina 30 MGD WTP Case Study 2 Piedmont North Carolina 30 MGD WTP

Case Study 2 30 MGD reservoir WTP The Problem 30 MGD reservoir WTP Conventional treatment and chloramination Algae and basin maintenance require raw water chlorination Elevated DBPs throughout WTP and in distribution system

Case Study 2 Pilot GAC with raw water chlorination The Solution Pilot GAC with raw water chlorination Improve TOC reduction Maintain current oxidation practices

GAC Installation Carbon Manufacturer Product Name Carbon Source Effective Size (mm) Uniformity Coefficient Pilot Filter EBCT (min) Calgon Filtrasorb 300 Bituminous Coal 0.80-1.0 2.1 10 and 20 Filtrasorb 400 0.55-0.75 1.9 Norit 12 x 40 Lignite 0.65 1.7 Hydrodarco 3000 0.7-0.9 1.6

GAC with Raw Water Oxidation

GAC with Raw Water Oxidation Instantaneous DBPs - TTHMs Approximately 6 months Approximately 4.5 months Approximately 3.5 months Approximately 2 months

Regulated DBP Comparisons Instantaneous DBPs – HAAs Approximately 6 months Approximately 4.5 months Approximately 3.5 months Approximately 2 months

GAC Treated TTHM Speciation Over Time

GAC Treated HAA5 Speciation Over Time

Additional HAAs are Controlled by GAC

GAC Treated Unregulated HAAs Speciation Over Time None None

Conclusions Online THM analyzers can provide valuable information Literature Models and Site Specific Models can assist utilities with compliance Post Treatment Aeration provides polishing for THMs out in the distribution system GAC can assist with DBP compliance Upstream treatment from GAC impacts DBP speciation and performance

Acknowledgements Hazen and Sawyer Allison Reinert Ben Stanford Mark Bishop David Briley Jay Jackson Justin Irving Participating North Carolina Utilities

Questions? Scott Alpert, PE, PhD Hazen and Sawyer salpert@hazenandsawyer.com Allison Reinert, EIT areinert@hazenandsawyer.com