The amount of time between cleanings depends on the tank size and the number of people that occupy the house. The average household needs to have the septic tank emptied every 2 years. The size of the tank is determined by the number of bedrooms the house was designed for. For example, a 3 or less bedroom house requires a 1000 gallon tank. A 4 bedroom house requires a 1250 gallon tank.
This tank has 2 compartments inside. The purpose if the 2nd compartment is to allow the solids to settle twice before leaving the tank. This tank has 2 covers. One on the inlet and one on the outlet side of the tank. The inlet is where the main sewage line enters the tank. The outlet is where the filtered effluent leaves the tank. As of July of 2000 all septic tanks must be installed with an effluent filter. This filter is installed in the outlet baffle of the tank. Both covers must be opened to properly clean the tank and the filter.