An author of a report outlining the impacts of dairying on the environment and the clean up costs it could create has hit back at criticism over the research.
The Massey University paper - 'Milking Our Environment for All Its Worth' - has refuelled the fire of the ongoing debate about dairying's environmental impacts after it was published in US journal Environmental Management.
The paper explored the dairy industry's expansion in recent years, its cost on the environment and the financial costs that society will incur to clean it up.
It concluded that the damage that intensive dairying has been doing to water quality would cost more to fix than the industry's contribution to the economy.
Federated Farmers has dismissed the research as flawed and sloppy. It said the figures it used were out of date and did not give an accurate picture of what was really going on.
It said the research based conclusions on assumptions and did not take into account the positive steps farmers have been taking to reduce their environmental footprints.
However, one of the authors, Dr Mike Joy, rejected that and said they used the latest data they could find.
"There's no way we could get data from anywhere else; the industry people may have the data but they don't make it public to anyone else," he said.
"Why haven't they done it themselves if they've got the numbers? Why aren't they doing externality studies and publishing it so the public can see what's happening with the costs of this industry?"
Dr Joy said many farmers were playing a part in trying to reduce water degradation but steps needed to be taken at a higher industry and government level.
"I think this whole country needs to have a rethink of where we're going with agriculture," he said.
"What we're doing is just mining the environment for short-term gains, and we're not thinking about the long-term and the future generations that will have to pay for the damage that we're doing right now."