The Ministry for Primary Industries (MPI) has today released guidelines for food producers and processors about how to ensure food safety and animal welfare after spreading rocks and minerals from drilling oil and gas wells on land, including the practice known as landfarming.
MPI Director of Resource Policy, David Wansbrough, says the guidance has been a collaboration between central and local government and industry groups.
"Everyone involved is committed to protecting the health and wellbeing of consumers and the welfare of animals. We even spoke to the farmers themselves who are proud of their ability to produce safe food and keep their animals healthy.
"The cornerstone of this work has been a detailed review and analysis of the New Zealand and international science by independent experts Landcare Research.
"The science tells us there is no risk to food safety or animal welfare if there is no grazing or harvesting until the level of hydrocarbons in the soil meet specified values.
"This isn't about fracking or pouring oil on land. It's about ground up rocks, mud and minerals left over from drilling very deep holes in the ground. Much the same as you would find if you dug a deep enough hole in your own backyard – mud, rocks, minerals and maybe some naturally occurring hydrocarbons.
"The hydrocarbons are at such low concentrations that the risk is low even immediately after being spread. We have set standards in the guidelines where we can be assured that there is no risk.
"We come into contact with low levels of hydrocarbons every day in soft drinks, coffee, vehicle exhausts, and barbequed food.
"Soil organisms naturally break down hydrocarbons like these, which is why it is a common and accepted practice internationally to spread these left-over rocks and minerals into soil.
"This process allows the rocks and minerals to be recycled to improve the productivity of some soils. They increase the clay content and improve the soil's ability to retain water and nutrients – this can improve pasture growth and reduce the risk of erosion.
"This guidance provides scientific assurance, regulatory clarity and a nationally consistent approach to ensure food safety and animal welfare."
The guidance document – Food Safety and Animal Welfare Guidance if Spreading Rocks and Minerals from Drilling Oil and Gas Wells on Land – is available online.
Download the guidance document [PDF, 489 KB]