Septic system owners are responsible for system maintenance. Properly maintaining your septic system will save you money and protect health and the environment. Owners must employ state-licensed maintenance businesses to periodically pump out solids from septic tanks to properly maintain their system. If solids aren't removed, the material can accumulate and move into the drainfield and cause it to fail, or even backup into the residence or business. Minnesota rules require that the system be assessed at least once every three years or when sludge and scum accumulate to the point of endangering the soil treatment system.