How Often Should I Empty My Septic Tank
We get asked this a lot! It seems everyone has an opinion and nearly all are different. We thought we'd approach the problem from a "bums on seats" perspective!
Septic tanks do need to be emptied, they are not self cleaning; however the frequency depends on the number of folks using the tank and the size of the tank. A typical domestic tank will have a volume of around 2600 to 3000 litres. The average adult produces 110g of poo each day so in a full year will produce 40 kg of solid waste. Most commercial treatment plants - the place your licensed contractor should take the waste - are designed to run best with a solids feed of around 5%. So, this is the target level.
So a family of four will produce around 160 kg of solids each year or 6% on a 2600 litre tank. In this case the tank should be emptied each year. Two people in the house should have the tank emptied every two years and one person can save a bit of cash and only have the tank emptied every four years.