WATER QUALITY Water Quality Annual Report 2016/17 1800 454 500 I [email protected] www.gvwater.vic.gov.au Water Quality Annual Report 2016-17 TABLE OF CONTENTS List of Figures ....................................................................................................................... 4 List of Tables ........................................................................................................................ 5 1 INTRODUCTION ........................................................................................................... 7 1.1 Water Supply Systems .............................................................................................. 10 1.2 Source Water Protection ........................................................................................... 12 1.3 Improvements to Water Supply and Treatment ...................................................... 14 1.4 Changes to Water Sampling Localities .................................................................... 15 2 WATER TREATMENT AND QUALITY MANAGEMENT SYSTEMS .................................. 16 2.1 Water Treatment ....................................................................................................... 16 2.1.1 Raw Water and Pre-Treatment ................................................................. 16 2.1.2 Chemical Addition, Coagulation and Flocculation ................................... 16 2.1.3 Clarification, Sedimentation and Flotation .............................................. 17 2.1.4 Filtration ..................................................................................................... 18 2.1.5 Disinfection ................................................................................................ 18 2.1.6 Fluoridation ................................................................................................ 18 2.1.7 Clear Water Storage (Storage of Treated Water) ..................................... 18 2.1.8 Distribution (Supply to the Customers’ Tap) ............................................ 19 2.2 Changes to Water Treatment Processes and Chemicals ....................................... 22 2.3 Issues to Note in 2016/2017 .................................................................................. 23 3 QUALITY OF DRINKING WATER ................................................................................. 24 3.1 Escherichia Coli ......................................................................................................... 24 3.1.1 Results ........................................................................................................ 25 3.1.2 Actions in relation to Non-Compliance ..................................................... 27 3.2 Chlorine Based Disinfection By-Product Chemicals ................................................ 27 3.2.1 Results ........................................................................................................ 28 3.2.2 Actions in relation to Non-Compliance ..................................................... 29 3.2.3 Actions in relation to Non-Compliance ..................................................... 32 3.2.4 Actions and Preventative Measures Taken in relation to Non-Compliance .................................................................................................................... 34 3.2.5 Actions in Relation to Non-Compliance .................................................... 36 3.3 Turbidity ..................................................................................................................... 36 3.3.1 Results ........................................................................................................ 37 3.3.2 Actions in relation to Non-Compliance ..................................................... 38 3.4 Ozone Based Disinfection By-Product Chemicals ................................................... 38 3.5 Aluminium .................................................................................................................. 38 Page 2 of 103 Water Quality Annual Report 2016-17 3.5.1 Results ........................................................................................................ 39 3.5.2 Actions in relation to Non-Compliance ..................................................... 42 3.6 Fluoride ...................................................................................................................... 42 3.6.1 Actions in relation to Non-Compliance ..................................................... 44 3.7 Other Chemicals that may pose a Risk to Public Health ........................................ 44 3.7.1 Results ........................................................................................................ 46 3.7.2 Actions in relation to non-compliance ...................................................... 73 3.8 Aesthetics .................................................................................................................. 73 3.8.1 Results ........................................................................................................ 75 3.8.2 Actions in relation to Aesthetic Issues ..................................................... 83 3.8.3 Missed Samples from Water Quality Monitoring Program ...................... 84 3.9 Analysis of Results .................................................................................................... 85 3.9.1 Water Quality Standards ........................................................................... 85 3.9.1.1 Analysis of results for E.coli and comparison with previous years .............. 85 3.9.1.2 Analysis of results for total trihalomethanes and comparison with previous years 85 3.9.1.3 Analysis of results for turbidity and comparison with previous years ........ 85 3.9.1.4 Analysis of results for other health related parameters.............................. 85 4 EMERGENCY AND INCIDENT MANAGEMENT ............................................................ 87 4.1 Known or Suspected Contamination ....................................................................... 87 4.1.1 Section 22s ................................................................................................ 87 4.1.1.1 Avenel Chlorine Overdose ........................................................................... 87 4.1.1.2 Barmah E.coli Detection (False Positive) ..................................................... 88 4.1.1.3 Shepparton Blackwater (Taste & Odour) Event ........................................... 89 4.1.1.4 Katamatite E.coli Detection (False Positive) ................................................ 90 4.1.1.5 Tatura E.coli Detections (False Positive) ...................................................... 91 4.2 Blue Green Algae Response ..................................................................................... 92 5 COMPLAINTS RELATING TO WATER QUALITY ........................................................... 96 5.1 Analysis of Water Quality Complaints....................................................................... 97 5.2 Customer Engagement around Water Quality ......................................................... 98 6 FINDINGS OF THE MOST RECENT RISK MANAGEMENT PLAN AUDIT ....................... 99 7 UNDERTAKINGS UNDER SECTION 30 OF THE ACT ................................................ 100 8 REGULATED WATER ............................................................................................... 101 9 FURTHER INFORMATION ........................................................................................ 103 Page 3 of 103 Water Quality Annual Report 2016-17 List of Figures Figure 1: Goulburn Valley Water Drinking Water Quality Policy .......................................................... 9 Figure 2: GVWs Operational Areas and Sampling Localities ............................................................ 11 Figure 3: DAFF Jar Tests Being Undertaken ...................................................................................... 17 Figure 4: New Nagambie WTP DAFF cells ......................................................................................... 22 Figure 5: New Nagambie WTP Plant Building.................................................................................... 22 Page 4 of 103 Water Quality Annual Report 2016-17 List of Tables Table 1: GVW Raw Water Sources and Localities Serviced ............................................................. 13 Table 2: Changes in Drinking Water Treatment Processes ............................................................ 14 Table 3: GVW Treatment Processes ................................................................................................. 20 Table 4: GVW Chemicals used in treatment ..................................................................................... 21 Table 5: Escherichia coli (Distribution) ............................................................................................. 25 Table 6: Escherichia coli (Clear Water Storage) ................................................................................ 26 Table 7: Chlorine based disinfection by-product chemicals – Trihalomethanes ............................ 28 Table 8: Chlorine based disinfection by-product chemicals – Chloroacetic Acid ........................... 30 Table 9: Chlorine based disinfection by-product chemicals – Dichloroacetic Acid ....................... 31 Table 10: Chlorine based disinfection by-product