Waikato Regional Council has started a prosecution against a piggery near Te Aroha following an investigation into the discharge of effluent into a stream.
The council has been looking into the alleged ongoing, uncontrolled and unauthorised discharges to both land and water over the past six months.
It believed the effluent entered the Patuwhao Stream, which flowed to the Waihou River, resulting in the council cautioning land owners downstream.
An interim enforcement order from the Environment Court was in place, which required the piggery to stop discharging a contaminant onto land in circumstances which may result in it entering water.
The council had been regularly inspecting the site, and said the volume and frequency of the discharges had decreased.
However, it would continue to monitor activities on the site.