Septic System Maintenance - Tank Outlet Filter

Do I need a Septic Tank Outlet Filter?

Septic tank outlet filters are a great idea but they require regular mainenance.  Septic tank outlet filters are not necessary for a properly sized and properly operated septic system.  Unfortunately, most of us make mistakes now and then and don't pay much attention to our septic system until there is a problem.  If you have better things to think about, a septic tank outlet filter may save you from the high cost to fix a failed drain field. 

Septic tank outlet filters are recommended upstream of pump tanks (required by some regulations). 

We also recommend septic tank outlet filters for houses with garbage disposals.    

Septic tank outlet filters will not protect your drain field from all forms of abuse, See the "Don't List".   However, the outlet filter may protect your drain field for a limited period of time from some forms of abuse, like waiting too long between septic tank pump-outs or excessive garbage disposal use.  This limited protection comes at a small cost, you need to regularly maintain the filter.   Without regular maintenance, the septic tank filter may plug and cause back-ups, gurgling, slow draining fixtures, or sewage overflow at the septic tank.

Plugged Filter and Septic Tank Back-up

A plugged filter and a septic tank back-up is aggravating when you need to deal with this problem on a cold night.  However, if the filter saves your drain field from plugging, it is well worth the aggravation.  The proper response to this event is to call a septic pumper.  The pumper will clean out your septic tank and clean the filter, any time of year (don't be shy in the winter).  Never try to fix this problem by pulling the filter out to let the septic tank drain.  Pulling the filter out of a surcharged septic tank will send solids, fats, oils, and grease down to the drain field.  This one event could plug the drain field and create a much more expensive problem to fix.

Septic Tank Outlet Filter Maintenance

Septic tank outlet filter maintenance consists of:

  • opening the port over the septic tank filter
  • pulling the filter, to inspect its condition
  • rinsing the filter, and 
  • re-installing the filter

This work should be done by a septic professional who knows the health and safety aspects of this process.   We suggest that filters be cleaned at least once a year.  Observed filter plugging and, back-ups may indicate that your system needs more frequent filter maintenance.  We also recommend more frequent filter maintenance for houses with garbage disposals.