What treatment occurs in the septic tank?
The septic tank provides primary treatment of the wastewater from the building. The first compartment of the septic tank is for separating the solid and floatable material from the liquid portion of the wastewater. Wastewater flows from the building into the first compartment of the tank, where it is retained for approximately 1.5 days. During that time, solids settle out and sink to the bottom, and oils and greases separate and form a scum layer along the top of the liquid. A relatively clear layer of liquid is created between the scum and solids layers. The remaining clear liquid flows through holes in the middle of the baffle wall into the second chamber of the tank, from where it goes out to the leaching bed. When wastewater flows into the tank, equal volume of effluent is transferred out of the tank and to the leaching bed.
