Canterbury farming representatives say more analysis needs to go into claims that farming is to blame for increased nitrate levels in the region's water supplies.
A report into the quality of groundwater in Canterbury shows 33 of 289 wells tested contain unacceptable levels of nitrate for drinking water.
Medical Officer of Health in Canterbury, Dr Alistair Humphrey, has raised concerns about health risks associated with that.
He puts the blame on more intensive farming in the region, and associated irrigation.
Federated Farmers Mid Canterbury president Chris Allen says however, it is not as simple as that.
He says the issues are complex and have been developing over a long period of time and the nitrate pollution could be the result of other factors - not necessarily just intensive farming.
Sir Kerry Burke who was chair of the Canterbury Regional Council, before the Government disbanded it and replaced it with commissioners, says if nitrate levels are rising, that's a disturbing trend.
He says although freezing works are likely the cause of some of the pollution, it is hard not to attribute some of the problem to intensification.
Sir Kerry says declining water quality would have been an election issue if people had been able to vote for a regional council.