You will require this permit if you intend to construct, install or alter a septic tank system. All septic tank systems must comply with the current Australian New Zealand Standard for On-site Domestic Wastewater Treatment Units - Septic Tanks.
Septic Tanks provide an onsite sewage disposal system for buildings on the urban fringe and in rural or remote locations that have no access to a sewer connection. You should regularly (at least every three years but preferably every year) pump out the sludge and solids from the tank.