What is a Biomat?
The biomat is a bacteria layer which forms in soil below and around the bottom of the drainfield where septic effluent or wastewater is discharged. This layer is critical in the processing of fine biological solids and pathogens which are in the effluent, and without it the septic system would not be adequately treating the effluent. Inadequately-treated effluent released into the ground risks contamination of nearby ponds, wells, streams, etc. A similar layer also forms around drywells used to accept graywater from buildings. Septic effluent, (or onsite wastewater), is discharged into a soil absorption system (or drainfield) from the septic tank which should, if it’s working properly, have retained all large solids. The job of the soil absorption system, or “SAS”, is to further treat the effluent to reduce the level of biological solids and pathogens to a level acceptable for further movement of the liquid into remaining soils. Inadequate treatment of effluent would mean that sewage a
