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How often should I pump my septic system tank?

 How often you need your septic system pumped depends upon the use it gets and the size of the tank. The following table is a good guideline, although specific systems and circumstances may vary. For example, a garbage disposal system increases the load by approximately 30%, meaning the system must be pumped more often.

Note that this presumes year-round occupancy -- obviously, seasonal use puts a lighter load on the system. Also note that this chart only applies to septic systems. It does not apply to simple holding tanks which retain all solid and liquid waste with no treatment or effluent disposal system.

Table I. Septic Tank Pumping Frequency in Years
. Household size - Number of Occupants
. 1 2 3 4 5 6 7 8 9 10
Tank-Gallons Septic Tank Pumping Frequency in Years
500 5.8 2.6 1.5 1.0 0.7 0.4 0.3 0.2 0.1 --
750 9.1 4.2 2.6 1.8 1.3 1.0 0.7 0.6 0.4 0.3
900 11.0 5.2 3.3 2.3 1.7 1.3 1.0 0.8 0.7 0.5
1000 12.4 5.9 3.7 2.6 2.0 1.5 1.2 1.0 0.8 0.7
1250 15.6 7.5 4.8 3.4 2.6 2.0 1.7 1.4 1.2 1.0
1500 18.9 9.1 5.9 4.2 3.3 2.6 2.1 1.8 1.5 1.3
1750 22.1 10.7 6.9 5.0 3.9 3.1 2.6 2.2 1.9 1.6
2000 25.4 12.4 8.0 5.9 4.5 3.7 3.1 2.6 2.2 2.0
2250 28.6 14.0 9.1 6.7 5.2 4.2 3.5 3.0 2.6 2.3
2500 30.9 15.6 10.2 7.5 5.9 4.8 4.0 3.5 3.0 2.6