3-OSS Design.pdf

This is a Septic Repair Design document for an on-site sewage system approved for permit release by the Traverse County Health Department on January 22, 2026. The design was prepared by All Septic Designs LLC for a property owner (Teresa Thurston) located at 4709 Ridgewest Drive in an unspecified jurisdiction, with design work completed on December 4, 2025.

The project involves installation of a new on-site sewage system designed for a 3-bedroom single-family residence with normal residential waste strength. Key design specifications include: a 1,500-gallon traffic-rated septic tank with risers and lids to grade; a 1,097-gallon traffic-rated pump chamber with float settings at 37.5 gallons high and 18 gallons low water alarm; a new SJE Rhombus IFS series EQ pump with time dose, ETM, CC and audio/visual alarm; and a pressure distribution system with an 8 APH rate of 450 gallons per day for a minimum of 562.5 square feet of gravel chambers in place of 3/4" to 1.5" clean drain rock. The system design incorporates an existing gravity drain and garage disposal per owner request. Installation requirements include confirmation that the existing tank is in good condition and watertight, incorporation of the existing garage disposal, connection of drainfield trenches with sleeved transport lines in the driveway, and monitoring port installation. The design parameter is increased to 150 gallons per bedroom per day with no expansion of the existing septic facility. Site conditions per soil logs show soils at 44" depth transitioning from dark brown mottled material through gravelly, slightly compacted layers with some mottling at greater depths.