Final tests have found an oil and gas drilling technique, which has been criticised by environmentalists, has not contaminated water at a Taranaki production site.
Hydraulic fracturing, or fracking, involves pouring fluids under pressure into oil or gas reservoirs to crack layers of rock and free trapped hydrocarbons.
But a final round of water sampling carried out by the Taranaki Regional Council has established the water quality at Ngaere is good.
Samples were taken from a spring and a stream flowing alongside TAG Oil's Cheal B exploration site, where fracking was done by the previous owners.
The council says the water met New Zealand Drinking Water Standards.
Taranaki District Council director of environment quality Gary Bedford says a trace of methane was detected in a sample from one spring, which was expected because the Ngaere area was originally swampy.