Drinking water arsenic levels get the all-clear

Levels of arsenic in drinking water from all three treatment plants in Waipā have returned to below Drinking Water Standards maximum acceptable values.

Yesterday evening’s results recorded 0.0078 and 0.0097 milligrams per litre from the two main treatment plants, down from 0.01 and 0.011 on Monday, and the original results of 0.0138 and 0.0145.

The Alpha Street plant results were 0.0078 milligrams per litre yesterday, down from 0.0117 on Monday.

The maximum acceptable standard for arsenic in New Zealand drinking water is 0.01 milligrams per litre.

Water services manager Karl Pavlovich said while the level drop is great news, the council will continue to test daily to ensure any further variation is captured.

“We’ll continue with our enhanced arsenic monitoring plan for the next few weeks and will also review our regular monitoring programme.”

“We’d like to collect more data on both the source of the arsenic and how the effectiveness of our treatment can be improved,” Pavlovich said.

Waipā draws some of its water from the Waikato River, where naturally occurring arsenic levels are generated by geothermal activity and accumulated arsenic sediments within the hydro lakes along the river.

The Water Services Authority - Taumata Arowai and Health New Zealand have confirmed that drinking water with slightly elevated arsenic levels for a short period of time is unlikely to impact health. The limits in the New Zealand Drinking Water Standards are based on the level of risk from a lifetime of drinking the water.