Most compact
The BioPod is the most compact biological treatment system that we know of.
It is a single, 3000 litre compact polymer tank (1.88m diameter by 2.06m high). This makes it easier to transport and it needs far less earthworks to install.
When installed, it is set in the ground, with only the inspection port and a small electrical control box visible. This makes it very unobtrusive in the garden.
Sandfilters - around 10 times larger than a BioPod
Sand filters (with their septic first stage) take up an area approximately 10 times larger than the BioPod. They occupy around 26 square metres, which is a lot of land area to excavate and occupy in your garden, especially when you consider that the sand filter will need to be completely dug up and replaced when it becomes saturated. The BioPod occupies only about 2.8 square metres.
Mechanically aerated systems can be large
Aerated systems can have multiple tanks and usually occupy a significantly larger land area than the BioPod.
It has a small footprint, so saves on excavation and installation costs. (Our ground is so rocky they broke a rock hammer at my place.) It also has a small eco-footprint as it uses no chlorine and hardly any electricity.
Maureen Lewis, Deakin ACT