Westland Milk Products has been fined after an accidental oil spill into the Hokitika River.
The West Coast Regional Council issued an infringement notice after investigating the September 30 incident in which a quantity of canola oil entered the river via a stormwater drain.
Westland Milk Products environmental manager ChrisPullen said most of the oil was contained on-site, and of that which did escape nearly all of it was confined within the floating booms placed in the river and was then removed using tractor-driven sucking equipment and scoop nets.
Oil deposits were also removed from along the shoreline, Mr Pullen said.
"However, after talking to whitebait fishers downstream, we confirmed that some oil did drift downstream and was visible in their nets, which impacted on their activities. This is regrettable and the company apologises for the inconvenience caused."
The company had conducted its own investigation, which found that the spill was not the result of any carelessness or failure to follow proper procedures.
The report was provided to the regional council.
Pullen said the dairy company had co-operated with the regional council's investigation and accepted its decision the incident should result in a fine.
"We very much regret this incident. Westland is very aware that we operate in a unique environment alongside the Hokitika River. It is precious to us as a company and we recognise that it is a tremendous community, recreational and cultural resource.
"Everything possible was done to remedy the situation and to learn from it so this sort of thing does not happen again."
The dairy company has commissioned work for the construction of a stormwater interceptor in its dryer 7 area to prevent any future incidents. Interceptors were already in place in other areas of the factory but the risk to the stormwater drain of accidental spills in the D7 area had not previously been identified, Pullen said.
