Maintenance of a Septic Tank
The most important element in the effective maintenance of a septic tank is desludging of the primary chamber periodically.
Contrary to what some people believe, ALL humans produce sludge.
How much? Roughly 90 litres per year. This the equivalent of a grown man. Given time this will compact to 60 litres.
Once this more than half fills the primary chamber, it then starts to overspill into the second chamber and into the percolation area.
Moreover, it reduces the available capacity for anaerobic digestion , thereby increasing the amount of untreated sewage to the percolation area.