How Often Should It Be Pumped - Mason County Public Health Septic System User Manual

How often should it be pumped?

Your system should be pumped WHENEVER IT NEEDS IT. This will be different
for everyone. Hard and fast rules like "pump the tank every other year" just aren't
scientifically valid. Also, pumping the system is hard on the bugs because it can
take years before the anaerobic zoo in your tank is functioning at its peak. Over-
pumping is hard on your micro-critters, and it's a big bite on your pocketbook.
How often you have to pump a septic tank is a function of how big the tank is
relative to how many people are using the system, and how they are using the
system. The chart below illustrates some average times between pumping,
based the size of the tank and the number of users. Please keep in mind that this
is 'average'. Your pumping frequency may be higher or lower – even with the
same sized tank and number of occupants.
SUGGESTED PUMPING FREQUENCIES
Suggested Pumping Frequency (In Years)
Tank Size
(gallons)
1000 gal 12 years
1500 gal 19 years
Adapted from "Estimated Septic Tank Pumping Frequency" by
Karen Manci, 1984 Journal of Environmental Engineering, Volume 110.
The most important thing remember is to check your system annually. Once your
system has to be pumped for the first time or two, your pumper should be able to
tell you the future frequency that is best for your system. Remember, if the
number of occupants or your use of the system changes, your pumping needs
may increase or decrease (i.e. – kids move out, kids move back in, you get rid of
your garbage grinder, open a home-based business, etc.)
When having your septic tank pumped, make sure to have the second chamber
checked if it is a two-compartment tank. If you have a pump tank, be sure that is
checked as well. Some materials can liquefy and then re-solidify, settling out in
the pump tank. Have them removed if they are present. You DO NOT want any
solids sucked into the pump and passed into the drainfield, this is a quick road to
failure.
WITH NORMAL USE:
Number of people using the system:
1 2
6 years
9 years
- 22 -
4 6
3 years 2 years
4 years 3 years
8
1 year
2 years