Water quality

​Ashburton District Council is committed to providing water that is safe to drink and meets the requirements of the Water Services Act.  This means complying with the Drinking Water Standards for New Zealand (DWSNZ).  There are a range of treatment systems we use to reduce the risk of contamination and minimise the risk to public health.

How does Council know the water is safe?

Water is regularly sampled to confirm the safety and quality of the water we supply to our customers.  The Drinking Water Quality Assurance Rules sets out how often the supplies must be sampled.  For example, water leaving the Methven water treatment plant is sampled twice a week.

Our monitoring process usually involves the following steps:

• Water samples are taken from sample points on the supplies
• Samples are analysed at Council's laboratory to see if the bacteria E. coli is present or not
• Samples that need analysis for other chemicals or metals are sent to another specialist laboratory

Council's laboratory has Ministry of Health recognition to do E. coli analysis and is independently audited every year.

If E. coli is found in the water the following steps are undertaken:

• Contractors investigate what caused the problem and fix it
• The public health authorities at The Water Services Authority Taumata Arowai are notified
• Where necessary, a boil water notice may be issued
• More sampling is undertaken until there are three days with no E. coli in the samples

Nitrate Levels in Council-Managed Drinking Water Supplies

All Council-managed drinking water supplies are routinely tested for a range of parameters, including nitrate levels. Recent monthly testing consistently shows nitrate-nitrogen levels below the maximum acceptable value (MAV) of 11.3mg/L.

You can view the latest water quality report here (updated monthly).

Council encourages private bore owners, especially those in rural areas, to test their water regularly, as these supplies are not treated or monitored by Council.

For more information on health standards relating to drinking water in New Zealand see Taumata Arowai.

I have my own private supply – is this tested?

If you are not connected to a Council supply and have your own water supply, Council does not monitor its water quality.

You can get information about safe and healthy private water supplies from Taumata Arowai and information about the risks from nitrates in groundwater from Environment Canterbury.

If you would like to have your water tested, there are a number of laboratories that will do one-off samples.  They will also be able to test for a wide range of things including chemicals and metals that the Council laboratory cannot.

If you are worried about the quality of your private water supply and need further information, please contact Council on (03) 307 7700.