Why is an Outlet Filter important?
Cleaning the outlet filter on your septic tank is an important part of caring for your wastewater system. The Outlet filter stops unsettled particles from leaving the tank and entering the land application system. This enhances the settling process and protects your soakage system from blockage.
If the Outlet filter is not cleaned it can block up, this can cause the tank to overflow disturbing the settling process. A blocked filter can result in raw sewage overflowing onto your property or bypassing the filter and blocking the soakage system.
Cleaning your Filter
1. Locating the Outlet Filter
The outlet filter can be found at the end of your septic tank, before it flows out to the land application system; or in the case of an aerated treatment system, before it flows into a second treatment stage. The filter is normally found under a 150mm cap as per the cross section below:
If you have a secondary treatment system with a septic as the first stage, the filter is found between the primary settling and secondary treatment tanks. These stages could be incorporated in a single tank, in which case the filter is found between chambers. The examples below shows where to find the filter on an Econotreat Advanced Secondary Treatment System:
Which in real life may look something like this:
In some cases the filter may actually be under the manhole lid. So if you can't find a pipe at the end of the septic tank, remove the manhole lid and check the outlet junction at the end of the tank. The manhole access could be a tidy concrete lid or something DIY like the below, depending on the age of the tank:
2. Remove the Filter
Before removing the filter we recommend you put on some gloves, as sewage contains bacteria such as E. Coli that could make you sick.
Now having locating the outlet pipe, remove the cap from the top of it. In the pipe you should be able to see a handle on the top of the filter. If the filter is blocked, it is possible that the water level in the tank has risen and the filter is no longer visible; in this case you will need to reach into the water or use a hook to locate the filter.
Now simply take hold of the filter and lift it out. There should be a little resistance as most filters have a seal to prevent water for short circuiting past. In the case of a Zoeller filter (they are blue and white) you will need to twist the filter to remove it.
3. Cleaning the filter
To clean the filter you can simply hose it down. You will need a bit of pressure or a brush if you don't have pressure. The flow of water on most filters is up the center and then out the sides, so to clean them you simply hose the outside and the sediment will be washed out the bottom.
The cleaning should take place in a garden or some place safe where the sediment can decompose. If you have children it will need to be somewhere that they won't come in contact with it. You could remove the manhole from the septic and wash the filter back onto the top of the septic.
4. Finishing up
Now the filter is clean you can put it back in the tank, ensuring it goes all the way down. Then put the cap back on the pipe.
Dispose of your gloves safely and clean your hands well.
