Canterbury's regional council has hit back at claims the water isn't safe to drink

Freshwater ecologist Mike Joy and Medical Officer of Health Alistair Humphrey have both called for Envrionment Canterbury to take urgent action - on increasing levels of nitrates in the region's water.

But ECan's top scientist Tim Davie says these actions are well underway, and it could just take a while to see the results.

He says drinking untreated water always has a risk associated with it.

But Davie says Canterbury's drinking water is no more dangerous than it was 10 years ago.