Understanding Your Septic

The Septic Tank

A septic system disposes of wastewater underground. A system has two parts—a septic tank and a disposal field. A septic tank is an underground box constructed of concrete or sometimes a round plastic tank. The septic tank removes most solid wastes from the water. Heavier solids settle to the bottom of the tank, where the bacteria break them down into sludge. Lighter wastes (some solids, grease, oil, and some paper) form a crust or a "scum" layer on top of the water. Cleaner water between the two layers flows into the disposal field. Most solids fall out of the wastewater and remain in the tank. Bacteria break them down into sludge but never eliminate them completely; periodic cleaning is needed. 

Diagram of a septic system: a house connected by pipes to a septic tank and drainfield underground.

The Disposal Field

There are different types of disposal fields. In each system, wastewater flows through pipes into layers of stone and coarse soil. The stone holds the water and allows it to filter slowly throughout the soil.

Service Area

Southfield, Farmington Hills, Carleton, Bloomfield Twp, West Bloomfield, Bloomfield Hills, Ann Arbor, Ypsilanti, Canton, Novi, South Lyon, Clarkston, Saline, Willis, Whitmore Lake, Franklin, Van Buren, Milford, Northville, Plymouth, Salem Twp, Belleville, Beverly Hills, Commerce, Franklin, and surrounding areas.