Bio-mat is the black, slimy dirt found over a septic system. (See the photo above.) It is a byproduct of anaerobic bacteria and it is the culprit that gives off that pungent septic system smell.
According to inspectapedia.com, bio-mat “is a bacteria layer which forms in soil below and around drain field trenches 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. 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.”
Inspectapedia.com continues, “The septic tank discharges septic effluent (or onsite wastewater), into a soil absorption system (or drain field, seepage pit, or cesspool). If it’s working properly, it should have retained all large solids. The soil absorption system, or ‘SAS,’ further treats the effluent to reduce the level of biological solids and pathogens, in order to reach an acceptable level for further movement of the liquid into the remaining soils. Inadequate treatment of effluent would mean that sewage and pathogens would be discharged into and contaminate nearby ground water.”
Bio-mat is a significant sign of septic drain field failure, but it’s not the reason for the failure. Learn more about the real reason septic systems fail by going to septicdrainer.com. Our site offers great tips and information, as well as an exclusive blog with the latest trends and insights.