A report commissioned by the Taranaki Regional Council has found the controversial practice of disposing of oil and gas drilling soil on marginal land increases its value tenfold.
The report by soil scientist Dr Doug Edmeades investigated soil fertility, heavy metals and petrochemical residues at three sites in the region.
It concludes the process, used along with irrigation and fertiliser, produces high quality pastures and can increase land values from $3000 - $5000 a hectare to $30,000 - $40,000 a hectare.
The council's environmental quality director Gary Bedford says the report fills a missing science gap from a farming perspective.
Mr Bedford says a decision by Fonterra not to accept any milk from farms where spoil from oil and gas drilling has been deposited is up to the company, but the report is still useful for all concerned.
Greens say report doesn't stand up to scrutiny
The Green Party says the report doesn't stand up to basic scrutiny.
Green Party energy spokesperson Gareth Hughes says the terms of reference are a joke and the report has been written by a known climate-change denier.
Mr Hughes says the report is flawed because it says all land farms are fit for dairy farming, when testing of contamination levels was only done on three land farms.
He says the report draws far reaching conclusions from a tiny data set and questions why the Taranaki District Council contracted someone who denies climate change to write the report.