A surfacing of septic water is caused by the age of the system, over use of water or high ground water caused by seasonal rains.
A lateral line is a drain field that disperses the septic water into the earth. Lateral lines connect into the tanks and are buried underground.
Pumping of a conventional system is the same as pumping out an aerobic system. By pumping out the system you are taking the solids out to prevent them from stopping up the lateral lines. Soil types and system types affect the operation of a system as well. Sandy soils work better and longer than clay [...]
The lateral fields are full due to high ground water or a failing system and simply will not take any additional liquids. There may also be a broken or clogged pipe causing it to not drain. Some systems are designed to use a lift pump which may also be failing.