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.