Horowhenua District Council has carried out further work to ensure the Tokomaru water supply remains safe to drink.
The latest upgrade has raised the pH level of the water from 6.2 to 7.2 to make it less acidic. This reduces the chance that the water will dissolve metals inside old tapware or plumbing found in some properties, which could release small amounts of metals into the water.
Last month a ‘do not drink’ water notice was issued to Tokomaru residents after elevated levels of lead were found during testing.
Further investigation showed the lead was coming from three dedicated sample taps used to test the water, which had corroded, and the water itself was safe to drink.
The corroded sample taps are used only by Council for testing water quality and are not part of the drinking water supply network. Work is underway to replace the taps.
Drinking water suppliers have a duty to ensure that the water they supply complies with the Drinking Water Standards, which set maximum levels for metals in water.
However, suppliers are only responsible for drinking water quality up to the point of supply, which is normally the toby outside a property.
Since the ‘do not drink’ notice was lifted on 9 August Council has continued extensive testing of the water quality, including at the Tokomaru School and the Tokomaru Early Childhood Centre.
This has shown the water up to the point of supply remains safe to drink and complies with the New Zealand Drinking Water Standards.
However, due to the risk of old taps or pipes within properties releasing contaminants into the water, it is recommended that people flush at least a large cup of water out of their taps first thing in the morning – this applies to all residents, not just those in Tokomaru.
Council says it will continue to test the Tokomaru water supply monthly until the end of the year, when it will revert to the statutory six-month cycle.
