The chamber compartments are T-shaped which prevents sludge from draining out of the tank and only allows effluent to exit the tank to the drain field.
If a drain field is saturated/overloaded then it creates sewage to flow on the ground surface and eventually creates backups in sinks/toilets.
Make a habit to flush human waste and toilet paper only.
Never flush :
Paper towels.
diapers.
wipes or baby wipes.
Coffee grounds.
condoms/dental floss.
Gasoline, pesticides, paint, oil.
Cigarette butts.
Cat litter.
Feminine hygiene items.
Typically concrete-made septic tanks last for 50-plus years.
In general, a septic tank should be pumped every three to five years and inspection should be done between 1-3 years.