Hi...

I wanted to discuss regarding emptying of septic tanks - mainly to assess their appropriate cleaning frequency.

In India there are codes and manuals which have standardized size and cleaning frequency of septic tank.These suggest a maximum interval of 2 years for cleaning of septic tanks and related sizes linked to loads.

But, during our study of onsite sanitation in a few cities in India, we have found that, septic tanks that are constructed on-site are generally over sized and their cleaning frequency is more than the prescribed limits of codes and manual (e.g. by the CPHEEO). The common septic tank cleaning frequency is around 7 to 10 years for such on-site constructed large septic tanks.

I would like to find out about the implications of large /oversized septic tanks which are cleaned at such long intervals. How would such long cleaning intervals affect the treatment of excreta waste in septic tanks.

Regards,
Aasim