Hi,

I intend to build a house in a 1/4 acre plot and I'm confused between installing a septic or bio digester. I understand that the digester's performance hasn't yet been proven as it's a new technology and that the recycled water has a distinct smell.

Could anyone share his/her experience on the same? What would you recommend and why?

I had a nasty experience on digester. After spending money including engaging an 'expert' to implement a digester for flashing toilets in my commercial building it was a disaster after one month. The recycled water had a bad smell; we tried all means to mitigate the bad smell until I gave up. I disconnected it in the 2nd month and wrote off the cost incurred.

Digester I mean, a biological septic tank that use bacteria to digest organic waste on site. As for, Bio-digester model type: T6 (18 persons) or T9 (up to 40 persons).

I second @TSi's sentiments. Mucking thro' this gray area as a control can lead to huge losses .. tho' I'm told that certain embassies use the digester (am yet to know which ones)

For a single dwelling unit, it is cheaper to install a septic tank. A septic tank designed properly can last even 20 years as it is self regulating.

In a bio-digester, for it to work well and depending on the design, one needs to pump (electricity) in air (oxygen) to aid the breakdown of nutrients by bacteria. This is called aerobic decomposition. To start the bio-process, you may require to seed the tank with the right bacteria.

If the oxygen is not enough in the tank, then you have anaerobic decomposition which produces methane (bio-gas) and other bad smelling gases such as hydrogen sulphide (smell of rotten eggs). A biogas plant is an example of an anaerobic bio-digester.

Bio-digesters malfunction primarily due to overloading (bacteria need time to break down the nutrients) and this means the design is not good. Also, you might murder all the bacteria for example using soaps that say they kill 99% of germs or introducing things like Jik that are otherwise household disinfectants.