The Green Party is welcoming an inquiry into so-called Taranaki landfarms, where oil industry waste is disposed of, but believes it should include other farms.
The Government has announced it is establishing a working group to look into the controversial farms after Parliamentary Commissioner for the Environment Jan Wright advised it to intervene.
Dr Wright said the big problem with the landfarms was there were no rules in place to stop dairy cows or other stock grazing on landfarmed areas before it was safe.
Green Party New Plymouth candidate Sarah Roberts said the working group should also look at other farms.
"A whole group of us in Taranaki who were quite concerned about what we were seeing happening here feel relieved that there is going to be a working group set up to deal with the problem of having livestock on oil industry waste," Ms Roberts said.
"The landfarms are a problem but we feel quite strongly that the scope of the working group needs to widen."
Ms Roberts claimed the Taranaki Regional Council was still granting consents to put waste at mixed-bury cover sites which were at wellsites, as well as at the landfarms - a number of which were on dairy farms.