Fonterra says milk from Taranaki dairy farms with oil and gas drilling waste buried on them is safe, even though it has done no special testing for contaminants.
Fonterra has decided to reject milk from new farms that are spreading - rather than burying - waste.
But its general manager of milk supply, technical and assurance, Andy Goodwin, says farms with drilling waste buried do not require special testing. He says the waste is at least a metre beneath the ground and won't come into contact with the pasture's root system, so it is not a food safety issue.
However, some environmentalists say the science and testing is simply not there to assure the waste disposal practices are safe.