A new report issued by Canterbury Regional Council has confirmed that nitrate discharges from farming are contaminating drinking water in parts of rural Canterbury.
The report was commissioned as part of a strategic water study. It assessed levels of nitrate leaching into groundwater from sources that include fertiliser and livestock dung and urine.
However, water quality in deeper aquifers, including those that supply the drinking water for Christchurch and most Canterbury towns, are not compromised.
The regional council says the report provides evidence that nitrate discharges are having negative impact on shallow groundwater supplies.