Pongakawa and Paengaroa residents experienced rashes and burning sensations on their skin and sore stomachs and puffy eyes after drinking water with higher than normal pH levels.
Western Bay of Plenty District Council issued a warning of higher than normal pH levels in water coming from council mains affecting properties in Pongakawa and Paengaroa yesterday.
During this time council received 20 calls from residents near Wilson Rd South and Arawa Rd who had noticed changes to their water.
A handful of residents reported skin reactions such as rashes and feeling burning sensations, while others reported having sore stomachs and puffy eyes or that the water felt slimy.
Properties in Paengaroa and Pongakawa were flushed and tested and all drinking water was now back within the recommended pH levels from NZ drinking water standards.
The council said anyone who was unsure should flush their taps for 10 minutes to ensure fresh water in their system or contact council if they are concerned.
A council spokesman said Monday evening's issue was thought to have been caused by a section of water main line that had not been active for a period of time being brought back on line without adequate flushing.
"This led to a body of water with higher than normal pH entering the main system affecting some properties in the Paengaroa and Pongakawa areas."
Contractors and staff worked overnight on Monday and through Tuesday to flush the water and test the eastern water system. They also visited properties to manually flush individual water supplies, advise residents and provide bottled water.
Both manual and electronic testing has been conducted which shows water pH levels are back to normal.
Council will continue to closely monitor the situation over the coming days.