Calculator
Solids build at a rate set by the household, not the tank. Pumping is due once they reach about a third of capacity.
On the permit, or stamped on the tank lid.
| Tank | 2 people | 4 people | 6 people |
|---|---|---|---|
| 750 gal | 4.0 yrs | 2.0 yrs | 1.3 yrs |
| 1,000 gal | 5.3 yrs | 2.7 yrs | 1.8 yrs |
| 1,250 gal | 6.7 yrs | 3.3 yrs | 2.2 yrs |
| 1,500 gal | 8.0 yrs | 4.0 yrs | 2.7 yrs |
| 2,000 gal | 10.7 yrs | 5.3 yrs | 3.6 yrs |
Subtract roughly a third from these if a garbage disposal runs daily.
Pumping costs a few hundred dollars. What it protects is the drainfield, which costs thousands to replace and cannot be unclogged once solids have sealed the soil surface. Everything else in septic maintenance is secondary to this one habit.