Effluent Filter

Effluent Filters are a simple and cost effective way to keep your system working properly and are now required in Indiana under 410 IAC 6-8.2.

Filters help to prevent suspended “stuff” (like hair and other solids) from leaving your septic tank and clogging up your absorption field. An effluent  filter mounts on your septic tank’s outlet or inside the outlet’s tee.   All water that exits the tank must first pass through the filter.   Most filters are made of plastic with 1/16th inch to 1/8th inch filter slots.

Servicing an effluent filter is simple. It usually means removing the filter from the tank and spraying it off with a garden hose.
This may need to be done as often as every six months or be able to operate fine for years, depending on the conditions in your tank and your wastewater flow. Septic pumpers  will service and/or replace your filter when they come out to clean your tank.

Indiana’s septic rule 410 IAC 6-8.2 (effective January 1, 2011) requires effluent filters (that meet  ANSI/NSF 46 Standards) in tanks on new construction projects.   These filters must be rated at 1.5 times the capacity of the septic tank.  This means that a three bedroom house with a 1000 gallon septic tank must be equipped with an effluent filter that is rated at 1,500 gallons per day.

If multiple tanks are used in series, the effluent filter should be installed on the outlet side of the last tank.   The Indiana septic rule also gives county health departments the option to require them in repair situations (where existing tanks are used in conjunction with new absorption fields).

The drawback to most effluent filters is that they can actually cause more harm than good unless they’re serviced on a regular basis (maintained by cleaning).  If neglected, most effluent filters plug up and greatly restrict the flow leaving the tank.  This eventually causes a high water level in your tank and  backups in your plumbing.   If a plugged filter causes a backup in your system, be sure to have your tank pumped down BEFORE you remove your filter.  Pulling your filter while there is a high water level in your tank will cause effluent, scum, grease and LOTS of suspended solids to get washed out into your absorption field – this is bad! To keep this from happening, you must pump the tank down (at least to the normal operating level) before you pull the filter.

The following is a picture of a PL-122 Effluent Filter System by Polylok Inc.  This is a great effluent filter that it NSF 46 approved, rated for 1,500 gpd, and approved in Indiana for 1000 gal. septic tanks.   The filters can be snapped together to increase filtration capacity(see below).  The red ball on the bottom makes a water tight seal when the filter is pulled and  prevents water and scum from rushing out of the tank if the filter is pulled when the water is high (as described above).

Meade Septic Design Inc. sells the Polylok PL-122 filter for $50.  Call me to order yours 574-533-1470.