Septic Tank and Drainfield Maintenance

There are many types of onsite sewage disposal systems in use today. One of the most common is a septic tank, followed by a lateral drain field. Septic systems can be installed only if the soil is permeable. A soil scientist can evaluate the soil and determine a permeability rate. The soil will give the sewage effluent final treatment and disposal.

A standard septic system consists of a septic tank, a distribution device (either a flow splitter or a distribution box), and the drain field. Septic tanks can be made of concrete, plastic or fiberglass. They must be of watertight construction. Septic tanks must have a riser that extends to the surface, allowing the tank to be pumped periodically. Effluent filters are recommended to be placed in the outlet sanitary tee of the septic tank. Effluent filters are very effective in stopping solids from leaving the tank and clogging the drain field. A distribution device is not needed if the lateral field is installed level. If it is not level, a flow splitter may be necessary to distribute the effluent equally to all laterals. The drain field. can consist of gravel with perforated 4" pvc pipe. Recommended alternatives are gravellous pipe or chambers.

Regular maintenance of a sewage system is the best prevention of failure. Periodic maintenance can significantly lengthen the life span of a system. Water conservation and waste disposal habits are also important.

The following guidelines should be followed:

• Practice water conservation. Water usage should be monitored to prevent flooding the system. (ie: stagger loads of laundry throughout the week instead of doing all of the laundry on Saturday.) Water saving fixtures in the shower and toilets can also greatly cut down on the amount of water used. Any water leaks must be promptly repaired.
• Do not use your sewage system as a trash can by adding materials other than domestic sewage. Keep chemicals (paint, thinner, pesticides, etc.) and non-degradable items (disposable diapers, sanitary napkins, cigarette butts, etc.) out of the septic system.
• Restrict the use of a garbage disposal. If a garbage disposal is used the extra solids introduced into the tank can increase the accumulation of sludge by more than 50%, requiring more frequent pumping.
• Do not pour grease or oils down the sink drain. They can clog up your drain field.
• Have the solids pumped out of your septic tank periodically. This will need to be done every 3 to 5 years depending on the size of the family living in the home. Keep a record of pumping, maintenance and other inspections. Keep a sketch of the system for future reference.
• Clean the septic tank filter (if you have one) by hosing the filter off back into the tank annually or as needed.
• Don’t cover the absorption field with a hard surface, such as concrete or asphalt. Grass is the best cover for the field. Grass will not only prevent erosion, but will help remove excess water.
• Keep surface waters away from the tank and drain field. This includes downspouts from your homes roof gutters. Also keep foundation drain and sump pump discharge out of the system.
• Do not drive automobiles or heavy equipment on the system.
• Do not disturb the area near the sewage system or the set aside repair area.

Return to the Environmental Health Division Homepage or return to the Columbia/Boone County Health Department Homepage