Households with drinking water bores near Palmerston North airport have been largely cleared of contamination by firefighting foam chemicals.
The chemicals, linked to run off from firefighter training at the airport, were found in only one out of a dozen bores.
In that bore, it tested at a level far below the maximum safe guideline.
"We are now in the process of informing the 12 households of the good news that their bore water is safe for drinking," Palmerston North Airport's chief executive David Lanham said in a statement.
Soil also tested at below the human health screening values for industrial and commercial land.
Surface water testing of Mangaone stream showed low levels of the chemicals.
Health authorities are still advising people to avoid eating eels or watercress from this stream, and various other waterways around the airport.
More tests are going on of eels and aquatic life.
The airport has admitted using a type of foam banned in 2006 up until last December.