Rural residents in North Taranaki are worried a composting operation, which receives truckloads of oil and gas drilling waste, is being allowed to pollute a nearby river.
Farmers in a small valley, north of Urenui, say the Mimi River ran white and foamy recently and they believe it can only have come from the compost and worm-farming site.
The company, Remediation NZ, takes waste including manure, fish and poultry waste and synthetic-based drilling fluids and muds from the oil and gas industry. The waste is converted into fertiliser and soil conditoners.
Neighbour John Oxenham said he complained to Taranaki Regional Council when the Mimi River turned white.
There have been odour problems coming from the site before, resulting in the company being fined in 2010.
But the council's resource management director Fred McClay, said samples were taken and no breach has been found.