My Account
Traces of the herbicide Hexazinone were detected in water produced by the Warkworth Water Treatment Plant, drawn from the Mahurangi River, during routine testing carried out by Watercare this month.
The level was 0.0005mg/L, which Watercare says is 800-times below the Ministry of Health’s maximum allowable value of 0.4mg/L. By late last week, the levels had dropped to 1000-times below the maximum allowable value.
An independent, UK-based microbiologist and leading authority on water quality, Professor Colin Fricker, was consulted on the readings.
Watercare says he confirmed that there was no public health concern associated with the levels of Hexazinone detected and no further action, other than continued monitoring, was required.
Watercare general manager service delivery Shayne Cunis says the operation of the treatment plant was adjusted to prevent the substance from entering the drinking water supply.
Hexazinone is a broad-spectrum herbicide that is often applied to control woody/herbaceous, annual and perennial weeds. It is known to be soluble in water, highly mobile and can leach from the soil.
Watercare publishes detailed water quality reports for all of its water treatment plants each year on its website.
