You will require this permit if you intend to construct, install or alter a septic tank system. This permit will be needed prior to a building permit being approved.
All septic tank systems must comply with Australian New Zealand Standard AS/NZS 1546.1:2008 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.