Earning your trust through reliable and efficient water management services.

OWWA/OMWA Joint Annual ConferenceMay 5 – 8, 2013Ottawa, Ontario

Killaloe Water System, AVIVETM Water Treatment andHuwa-San PeroxideAndy K. Valickis, P.Eng.

Jim ShubatMay 7, 2013

2

Problem

To find a cost effective solution to reduce the high level of THMs in the Killaloe Water System

3

Killaloe Water System

• Small system – only 90+ connections– Owned by the Township of Killaloe, Hagarty and Richards– Operated by OCWA

• Groundwater wells– GUDI with in-situ filtration– Treatment for iron and manganese removal – UV discharging to clearwells

• Long residency time in clearwells and distribution system (3 to 5 days)

– THM levels near or over the 100 µg/L limit– Individual samples as high as 140 µg/L

4

Solution

• AVIVETM Water Treatment system from SanEcoTec • Using Huwa-San peroxide (HSP) New form of stabilized

peroxide that maintains its residual (equivalent if not better than chlorine)

– NSF approved as a residual for drinking water – Used successfully in Europe in drinking water since 2004

• Use HSP for secondary disinfection in the clearwells and distribution system

– No chlorine to produce THMs

5

Advantages of AVIVETM and HSP

• Does not breakdown to form THMs or other chlorine based DBPs

• Attacks biofilm on pipe walls– Very strong oxidizer

• Longer lasting residual• Easy to use for operators

– Similar to sodium hypochlorite

• No chlorine taste in the drinking water– Significant consumer acceptance

6

Project Approach

• Met with MOE (regulators)– Essential to get their buy-in

• Sold the concept to the Township staff and Council– Including our own operations staff

• Numerous consultation meetings with MOE Approvals and Health Unit staff

• Undertook baseline monitoring and sampling• Public notification

7

Baseline Monitoring and Sampling

• THM formation– Historical THM concentration data available but not where

along the process are the majority of the THMs formed– Undertook jar testing to develop a baseline and confirm

HSP works

• ATP testing of the existing system– Baseline of microbial activity within distribution system– Undertaken over a number of weeks

• Other testing– HPC, Total Coliform, E.Coli– Metals testing (copper, lead, iron, manganese)

• Residential hot water systems

8

ATP Testing - Luminultra

• Measures Adenosine Triphosphate– A chemical found in living microorganisms– Quantitative indication of microbial activity in a sample– Results in 5 minutes– Indication of the amount of biofilm on pipe walls

• Testing equipment loaned to this project by Luminultra– Sampling and testing undertaken by staff from OCWA and

Fleming College’s CAWT

9

System Design

• Still need chlorine to achieve CT requirements– Chlorine added to incoming raw well water – Used residency time in contactor tanks and pipes (before

UV) to achieve CT

• HSP added immediately after UV system– Measure chlorine levels then adjust HSP dosing to quench

chlorine + enough to maintain minimum secondary disinfection residual of 3 mg/L

– With the quenching of the chlorine, THM formation immediately ceases

• Issue of backwashing contactors with “peroxidated” water– Filter to waste until chlorine levels restored

10

MOE Approvals

• Regulatory Relief– Sections from O. Reg. 170/03 under the Safe Drinking

Water Act

• Amendment to the DWWP– Additional sampling and reporting for initial 3 months– Voluntary sampling (i.e. residential hot water systems)

11

Equipment

• Very similar to what is required for feeding and monitoring sodium hypochlorite– Chemical feed pumps (off the shelf)– Peroxide residual monitors (supplied by Kramer)– Handheld units for sampling in distribution system

12

Results

• HSP system was commissioned and went live in late November 2012

• Immediate THM reduction

– Initially down to 25-27 µg/L range– Current levels are in the 20-23 µg/L range

• HSP residuals maintained throughout the distribution system

• Water quality during the changeover was not affected

• HAAs were also significantly reduced– Before 55 to 67 µg/L range; after 8.4 µg/L

13

HSP Residuals

14

THM Reduction

Post-HSP

15

ATP Testing Results

Pre-HSP Post-HSP

16

Residential Hot Water Systems(Microbiological Activity)

Post-HSP

Pre-HSP Post-HSP

17

Conclusions

• Project a big success!– Significant reduction in the DBPs produced– Proved HSP can retain a disinfecting residual

equivalent to or better than chlorine– Significant consumer acceptance of their “new”

tap water

• We finally have a viable alternative to chlorinating our water supplies

18

Special Thanks

Earning your trust through

reliable and efficient water

management service.