Homes built from 1960 to 1965 could have either a Block or Precast Cesspool.
Pre-1959 homes usually have Block Cesspools. Homes built after 1965 usually have Precast Cesspools
If you have a Block Cesspool, NEVER pump all the water out of the cesspool as it could cause a collapse.
A Precast Cesspool will never collapse.
With Precast Cesspools you should always try to pull the whole cover on the main pool, which is 32 inches in circumference, to allow all solids to be pumped out. This should be done every couple of years.