Your Septic System
How Your Septic System Functions
The typical septic tank is a large, buried, rectangular or cylindrical container made of concrete, fiberglass or polyethylene usually located 10 or more feet from the point where the sanitary drain leaves the house. Wastewater from your bathroom, kitchen and laundry flows into the septic tank. There, heavy solids settle to the bottom where bacterial action partially decomposes the solids into sludge and gases. The lighter solids, such as fats and greases, rise to the top and form a scum layer. The partially treated effluent then leaves the septic tank and flows to the drainfield. Septic tanks have one or two compartments specifically designed to capture the solids and prevent them from entering the drainfield. Two-compartment tanks do a better job of capturing the solids and may be required in new installations. Tees and baffles are essential parts of the septic tank. Some tanks are equipped with an inlet tee or baffle to slow incoming waste and direct it downward. The outlet tee or baffle prevents floating solids or scum from leaving the tank and then clogging the drainfield. Some tanks are also equipped with an effluent filter to further prevent the movement of solids into the drainfield. All septic tanks should have accessible covers for checking the condition of the baffles and for pumping out the accumulated sludge and scum mat. If accumulated solids are not regularly removed from the septic tank, they will overflow into the drainfield and cause premature failure of the drainfield resulting in costly repairs or replacement.
Servicing the Septic Tank
Regular servicing of the septic tank is the single most important maintenance requirement of a septic system. Required frequency of service depends on septic tank size, the number of persons in the household and whether occupants are minimizing the release of unnecessary solids into the wastewater. Most septic tanks should be pumped every three to five years.
How do I determine when to pump?
Most homeowners prefer to give this responsibility to a reputable septic tank pumping firm. Its representative will periodically check your system to determine the rate of solids accumulation and design a pumping schedule tailored to your situation. As a general rule, the tank will require pumping when any of the following occurs: the top of the sludge deposit is within 12 inches of the bottom of the outlet baffle; the bottom of the floating scum mat is within 6 inches of the bottom of the outlet baffle; the top of the floating scum mat is within 1 inch of the top of the outlet baffle or; the floating scum mat is more than 12 inches thick.
Should I use special products to enhance the operation of my septic tank?
No. Though many products are claimed to improve septic tank performance or reduce the need for routine pumping, they have not been found to make a significant difference. Some of these products can actually cause solids to be carried into the drainfield and lead to premature clogging. Other products containing organic solvents can contribute to groundwater contamination.
Where is my septic tank located?
The tank is usually located about 10 to 15 feet from the point where the sanitary drain leaves the house. It can be found by gently inserting a steel rod (soil probe) into the ground where the tank is most likely to be or by waiting for a light snowfall and observing where the snow first melts.
Reference:
Dersch, E. (2005). Managing Your Septic System. Michigan State University, page 2 - Click here to view full article
 |
 |