Environment Canterbury councillor Vicky Southworth wants the regional council to take a leadership role over groundwater pollution of water supplies. Photo / RNZ, Nate McKinnonEnvironment Canterbury councillor Vicky Southworth wants the regional council to take a leadership role over groundwater pollution of water supplies. Photo / RNZ, Nate McKinnon

ECan chairman Craig Pauling says the council has been working towards improving water quality for many years. Photo / RNZ, Nate McKinnonECan chairman Craig Pauling says the council has been working towards improving water quality for many years. Photo / RNZ, Nate McKinnon

Mapping of nitrate-nitrogen samples by concentration shows the Ashburton region had the highest nitrate concentrations, similar to previous years' surveys. Photo / Environment CanterburyMapping of nitrate-nitrogen samples by concentration shows the Ashburton region had the highest nitrate concentrations, similar to previous years’ surveys. Photo / Environment Canterbury

Agriculture Minister Todd McClay says ECan voting on a motion on the council’s last sitting day before the election was a “gimmick or a political stunt”. Photo / RNZ, Reece BakerAgriculture Minister Todd McClay says ECan voting on a motion on the council’s last sitting day before the election was a “gimmick or a political stunt”. Photo / RNZ, Reece Baker