Inspection and Pumping
Compliance inspections have three basic criteria.
1. The tank(s) have to be sealed and in good condition.
2.The system cannot show obvious signs of failure, which would be a high level of liquid in the tank, surface discharge in the yard or backing up in the house.
3. The drain field must have at least a 3' separation between the bottom of the rock and saturated soil. 2' if the system was installed before April 1st 1996.
The MPCA recommends pumping a septic tank every 3 years or less. Local municipalities may require it sooner. The purpose of pumping the tank is to get the sludge and scum layers out of the tank before they get thick enough to work their way past the baffles and enter the drain field where they contribute to the bio mat build up and eventually cause hyrdraulic failure. Think about it, moisture in the form of rain, snow, spring run off etc. has been soaking into the soil since time began. Water in a drain field would similarly work forever. Then why do drain fields fail? It's the sediment from the tank getting into the drain field. Regular maintenance (pumping) prevents this from happening.