Orenco’s 18-in. external effluent filter basin, featuring patented Biotube® filter technology, is an ideal way to improve performance of existing residential septic systems by reducing solids discharged to the drainfield. External filter basins eliminate the need to make costly and sometimes hazardous modifications to existing septic tanks with restrictive access openings or to unusable outlet baffles or tees. Composed of an 18-in. diameter section of ribbed PVC pipe with a fiberglass base and 8-in. diameter Biotube® effluent filter. A grade ring insert (supplied) and a fiberglass lid are required to bring the unit up to finished grade.
