Rigorous Testing Applied to Water Supply
MACKENZIE DISTRICT COUNCIL PRESS RELEASE
RIGOROUS TESTING APPLIED TO WATER SUPPLY
29 August 2016
For immediate release
Mackenzie District Council says it’s committed to keeping ratepayers’ water safe with regular testing and monitoring of district water supplies as required by New Zealand’s Drinking Water Standards.
All of the district’s public water schemes are treated with chlorine and water schemes in Tekapo and Twizel are also filtered and UV treated.
Utilities Manager, Geoff Horler, says all water supplies are regularly tested for E.coli.
“For Tekapo and Fairlie we test the water at source and in the reticulation system weekly. In Twizel we test at source twice a week and in the reticulation system weekly. In our smaller centres such as Allandale and Burkes Pass, we test at source weekly and in the reticulation system monthly.”
Results come back from the testing laboratory within 24 hours.
“What we’re looking for is an E.coli count of less than one. If a test fails then we need to try and find out why,” Mr Horler says.
In January two tests at the Fairlie Treatment Plant returned positive for E.coli as did a further test in June. This was because testing was carried out too close to when the water had been treated with chlorine, not allowing the chlorine time to spread through the system. There was also one further positive test in the reticulation system in May, due to an equipment failure.
Water in the Twizel and Tekapo schemes is primarily treated with ultraviolet, with chlorine added as a safety net.
Chlorine is added to all water supplies at an extremely low level of about 1 part per million, Mr Horler says.
“We’ve got a rigorous system that we’re always reviewing and monitoring. In Twizel we’ve spent $3.5 million installing filters and UV treatment systems to obtain better quality water. Similarly, in Tekapo, in the last three years we’ve installed good quality UV treatment systems.”
“We’re confident that our systems are robust and we’re always looking to make improvements and find better ways of doing things,” Mr Horler says.