Residents of the small North Island town of Raetihi are being warned some people may find their drinking water tasting of diesel, even after is finally cleared to drink.
Efforts continue to flush contamination out of the town's water reticulation system after a diesel spill 11 days ago, although locals have been told their water may not be drinkable until 2014.
Ruapehu District Council's deputy mayor Don Cameron says it is fully expected that even when eventually tested safe, the water in some homes may still have a diesel taint, and could do so for some time.
Meanwhile Mr Cameron says it is hoped residents will get non-drinkable running water back on for flushing toilets as soon as Friday, and water suitable for shower and laundry use by next week.
He says the council will continue to provide drinking water for the community until all homes have their tap water completely cleared.
Farmers near Raetihi have been told to be careful if they're taking water for their stock from the local river, as rain flushes more diesel through the waterway.
The Manawatu Whanganui Regional Council group manager of strategy and regulation, Nic Peet, said the diesel that remains in the catchment will gradually move through the system, particularly after heavy rain.
And Federated Farmers Ruapehu president Lyn Neeson warned that farmers needed to be alert to rising water levels and the potential for further diesel contamination.