A New Zealand dairy farm and a milking contractor have been fined $29,000 each for letting dairy effluent accumulate on a paddock, which risked contaminating groundwater.
About 136,000 litres of effluent – wastewater from a milking shed containing faeces – poured onto a paddock on a farm near Rangiora in Canterbury in March last year.
The farm is on top of several underground springs.
Water quality in the immediate area has been declining and its shallow groundwater puts it at a higher risk of contamination.
Mairangi Dairies, the farm's owner, pleaded guilty to discharging effluent and was fined $29,000.
Ponded effluent can flow into surface water bodies and seep through the soil, leaking into groundwater.
The ponding was caused by a malfunctioning effluent system, which both companies said the other was responsible for maintaining.
The court found both were accountable for letting the discharge occur.
Environment Canterbury, which brought the prosecution, said both the public and the dairy industry expected it to take action over offending at this level.
Maps show the farm is on top of several springs, and its groundwater is less than six metres deep, shallower than much of the region.
"Waterways in this area are particularly susceptible as the groundwater is very shallow," principal resource management adviser Richard Purdon said.
"There are springs nearby and the water quality has been progressively deteriorating.
"Environment Canterbury pursues this kind of offending through the courts to make it very clear to the parties responsible, and the industry as a whole, that they need to be vigilant when managing their dairy effluent."
Alongside the $29,000 fine, both companies were ordered to pay about $3000 each in costs.