New test results show several Canterbury councils have recorded high levels of nitrates in the water.
The results, provided to Forest and Bird under the Official Information Act, show 19 testing sites have a level of 5.65 milligrams of nitrogen per litre or higher, which is seen as the trigger point of concern for health authorities for ongoing monitoring.
The organisation says the data shows Selwyn, Ashburton, Timaru, and Waitaki are all areas of concern.
Linn Koevoet lives in Glenavy, a small town near the mouth of the Waitaki River. He is a Fish and Game councillor and sits on the Lower Waitaki River Management Committee.
