Moa Flat & Heriot - Boil water & aluminium reminder

Consumers in Heriot and on the Moa Flat Rural Water Scheme are reminded that a boil water notice is in place.

Separately, an aluminium advisory is also in place for the Moa Flat Rural Water Scheme.

About the boil water notice

New drinking water standards were introduced in November 2022. Unfortunately processes at the Moa Flat Water Treatment Plant, which was designed prior to this, do not treat the water to meet these standards for protozoal and bacterial measures.

The water source is from Timber Creek, approximately 17km upstream of the plant. The water goes into a large pond which has about two months storage capacity. The colour, natural organics and low levels of silt in this water make it difficult to treat. It needs to comply consistently with requirements of the Drinking Water Quality Assurance Rules.

Council has been working with an independent water engineer to improve processes at the plant.

We have worked through a number of their options for improvement, but they have not been sufficient to lift the boil water notice. In December 2024, Council began an Organic Carbon Filtration trial at the plant and we hope this will be a successful solution to lift the boil water notice. This trial will need to run for three months before we are confident of long-term success. If this does not work we will work with the Rural Water Scheme Committee on further options.

You can read more about this update here.

Council advises anyone using water from their tap for consumption (including teeth cleaning and food preparation such as washing fruit and vegetables) should boil it for 1 minute before it is used.

You can bring your own clean containers to fill at the water tank available at the Heriot School grounds.

You can read our boil water FAQs at www.cluthadc.govt.nz/boil-water-faqs

About the advisory

The aluminium advisory remains in place as test results continue to show some elevated aluminium levels from time to time.

Read more about the aluminium advisory including advice and the latest test results at www.cluthadc.govt.nz/advisory

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