The report covering 2017-18 shows that of 55 water supplies in the region, 87.3% did not reach Drinking-water Standards for New Zealand and 40% did not reach drinking water standards under the Health Act.
The report was discussed at a council meeting yesterday during which policy and planning acting manager Anita Dawe said some, but not all, of the failures were technical in nature.
The council's responsibility specifically covers the drinking water at its source.
Cr Laws said he was ''disappointed'' to read the staff report.
''The reality is the majority of suppliers failed national standards. We are responsible for overseeing this matter. I am concerned that the ORC is involved in this now.''
If the council let suppliers ''get away'' with technical problems it was not doing its job, he said.
''What are we going to do about it? Whose responsibility is it?''
Cr Ella Lawton questioned whether it had taken the issue seriously.
Council chief executive Sarah Gardner said the Government was reviewing drinking water and assessing what the responsibilities of different agencies were.
New legislation was likely to come out regarding this soon.
While the council had a responsibility for the water at its source, whether it was fit for consumption was the job of the ministry and supplier, she said. Whether it had a role to play in any failures detailed in the ministry report depended on the reason for each failure.
