501 W Main St, Northville, MI 48167-1576 | Mary K. Gallagher, Superintendent
How the septic system works
Waste material from the house enters the septic tank where:

When waste enters the tank, bacteria begin to break down the solid materials. This break down reduces solids, but also leaves a residue behind in the tank. As time passes, this residue builds up, and must be removed to prevent it from entering the drainfield and clogging the system. The center liquid layer flows slowly from the tank into the drainfield. Perforated pipes allow the liquid to be equally distributed in a gravel-filled disposal field. Once the liquid reaches the disposal field, it soaks into the soil. The soil then acts as the final filter for treatment of waste received from the septic system. »Next Section
Septic Tank Maintenance Information