Work begins to replace untreated water supply

The days of Otematata residents having to boil their drinking water may soon be over, as a new water supply is expected to be commissioned by April.

Work on the upgrade has already started and bores have been sunk for a supply of clean water. This week, construction started of a building to house the ultraviolet light treatment. Piping is already in place.

The supply dates back to when the town was created to house workers on the Benmore power project in the early 1960s. Residents have had to boil untreated drinking water for years.

While they will still have to do that until the new supply is commissioned, Waitaki District Council water and wastewater asset manager, Martin Pacey, said the new supply would deliver clean water that might not have to be chlorine-treated.

It will have ultraviolet treatment to kill ''bugs'' and might not require chlorination, although that will have to be confirmed by ongoing monitoring.

Under the existing scheme, water is pumped from the Otematata River to an open dam and flows to the town from there. Untreated, it is subject to a permanent ''boil water'' notice for drinking, brushing teeth and preparing raw foods (salads and fruit).

To replace that supply, a quality groundwater source had been found east of the river which should meet the required drinking water standards. After ultraviolet treatment, it will be pumped directly to the town. Two tanks behind Otematata will hold a back-up supply, in case electricity fails.

A ''significant portion'' of the cost of the new supply is coming from depreciation built up in the Otematata water supply account and the rest from a loan. The rating impact would ''not be large'', Mr Pacey said.

The upgrade is part of work on 17 schemes, which supply about 20,000 consumers in the Waitaki district, to meet drinking water standards.

About 85% of consumers on about half of the schemes, including Oamaru, already have upgraded supplies.

The council is investigating groundwater supplies for both Omarama and Ohau, to get quality water which could meet standards without chlorination.

Work will start shortly on connecting Kakanui to the Oamaru water supply. The $870,000 cost includes laying a 9km long water pipe, along with an 8km waste pipe to handle sewage, connected to the Oamaru treatment plant.

About 90% of the route for the two pipes has been sorted, Mr Pacey said.

Other schemes due for upgrading include Herbert-Waianakarua, Hampden-Moeraki and Duntroon.

- david.bruce@odt.co.nz

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