Fire and Emergency is asking people living near a Waikato landfill that's been burning for three days to stay indoors.
Three helicopters, almost 10 ground crews and 40 fire fighters are working to dampen flames and contain the fire at the Hampton Downs Landfill.
Landfill operators are also using heavy machinery to cover the tip face with clay to help extinguish the fire.
Wind in the area changed over night, so smoke from the blaze will now drift in a south-westerly direction.
Fire and emergency says residents nearby should stay inside and keep windows and doors closed.