High alkaline levels behind Bay of Plenty water warning

Pukehina beach is one of the areas where people were warned against water use today. Photo/file

High alkaline in the water has been identified as the reason behind an urgent warning in eastern areas of Western Bay of Plenty today.

Early testing suggested the water supplied to Pukehina Beach, Paengaroa, Maketu, Little Waihi and Pongakawa areas this morning had high pH and therefore the water was overly alkaline, the Western Bay of Plenty Council stated in a media release.

"Neutral pH is 7 and testing today showed the water may have had a pH of 9-10," it stated.

"This could be an issue for people with sensitive skin causing irritation and the water should not be drunk, but it is not thought to be unsafe."

Potential of hydrogen (pH) is a scale of acidity from 0 to 14. More acidic solutions, have lower pH. More alkaline solutions, have higher pH. Alkalis have a pH greater than 7.

The council said the water treatment plant should have been automatically shut down until the fault was corrected, but this did not occur overnight and the council was investigating what caused the failure.

The council was advised of a potential issue with the water supply about 7.30am today.

Staff were manually operating the water treatment plant at Pongakawa and the Maketu Reservoir had temporarily been isolated.

Parts of the water supply area were being flushed to restore the correct pH balance and this could take a few hours.

Residents in the potentially affected areas were advised to not drink or bathe in the water until the all-clear was given.

Once this occurred people should flush their own systems by running water taps for 10 minutes to clear.

Water cylinders should be flushed completely and households with header tanks are advised to do the same.

Council utilities manager Kelvin Hill said once this has been done people should rub their fingers together in the running water and if it feels slimy to the touch, then keep flushing.

The issue is similar to having an imbalance in your spa or swimming pool water, he said.

"At this stage we believe the effects of taking a shower in this water for people with sensitive skin would be no more than potential irritation and possibly a rash, but we'd advise anyone with concerns to seek medical advice."

Council would continue to provide updates on the flushing process throughout the day and advise when the system has been restored. Local schools and the Medical Officer of Health have been notified.

Water was being made available from water tankers and bottled water in the potentially affected areas.