Managing Your Household Septic System

Sending wastewater to the tank too fast can cause solid materials to pass into the drainfield without undergoing the gradual anaerobic digestion that occurs in the septic tank. You should conserve water use in the house to ensure:

• slow movement of wastewater into the tank,
• reasonably complete digestion of solids, and
• slow trickling of wastewater from the tank to the soil treatment area.

No more than two loads of laundry (one in the morning and one in the evening) should be done a day. Avoid marathon showers and other excessive uses that may send big surges of wastewater into the system. Consider using water-saving devices available for toilets and shower heads.

There is no consensus within the onsite wastewater treatment industry about wastewater from water softeners. Research is being conducted to better understand the consequences of disposing water softener wastewater into septic systems. In the mean time, we recommend avoiding the practice.

Do not connect sump pump outlets or roof gutters to the system. Be make sure that any runoff from the roof, driveway, and other impermeable surfaces is directed away from the soil treatment area. In doing so, you will prevent accumulating water in the soil treatment area.

The quality of your wastewater — not just its quantity — is also important in ensuring that your septic system functions properly. Fats and grease should never be poured down the drain. They can solidify in the lines and cause failure; they can cause excessive buildup of the floating scum layer in the septic tank; and they can get into the soil treatment area and surrounding soil and seal the system off altogether.

Limit your use of garbage disposals or don’t use them at all. Septic systems are intended to be used for the treatment and disposal of human wastes and wash waters that come from the home. Only household cleansers, disinfectants, and bleaches should be allowed into the septic tank and only in moderation. Anything else does not belong in a septic system. Do not put any toxic or hazardous materials, such as paints, thinners, waste oils, photographic solutions, or poisons into a septic system; they will not be treated sufficiently to prevent contamination of water that returns to your local groundwater and or surface water.

Other materials that cannot be decomposed in a septic system include coffee grounds, dental floss, disposable diapers, cat box litter, cigarette butts, sanitary napkins, tampons, plastics, facial tissue, and paper towels. Such materials merely increase the risk of plugging and necessitate more frequent cleaning. Drains should be equipped with strainers or other filtration devices to reduce the amount of food particles, hair, and lint entering the system.

Slow accumulations of sludge and scum are normal. You should remove these materials through periodic pumping and appropriate disposal. This will protect the soil treatment area from materials that will damage its effectiveness.

Annual or semi-annual inspection of the septic tank is advisable to determine the thickness of the sludge and scum layers. A probe may be put into the tank from one of its access ports to make this determination. If you have any doubts about inspecting the septic tank, a private contractor who specializes in septic system cleaning and pumping can be found in your telephone directory. This service will cost you some money, but it is less expensive than digging up a fouled soil treatment area.

Additives that are marketed as septic tank cleaners, rejuvenators, or primers are not needed. Most of these additives won’t harm your system, but they don’t help them either. Some of these additives are strong chemicals that can harm a septic system.

Activities that help to maintain the septic tank will also maintain the soil treatment area:

• keep tank free of excessive sludge,
• ensure that tank is used within its designed capacity, and
• ensure proper quality of wastewater.

All this assumes that the wet-season water table is at least 2 feet below the bottom of the drainfield and that the soil is adequately permeable. Additional measures that you can take include:

• keep vehicular traffic off of the soil treatment area because vehicles can compact the soil and possibly break drain lines,
• try to position trees so that their roots will not enter the drain lines and plug them, and
• keep a healthy grass cover over the system to prevent exposure of the soil and possible erosion around the drain lines but don’t over-irrigate the grass, otherwise your soil treatment area must work harder to remove the excess water.

Properly sited, designed, constructed, and maintained septic systems can provide an efficient and economical wastewater treatment alternative to public sewer systems. While septic systems are designed and installed by licensed professionals to meet the needs of individual sites, homeowners are responsible for the system’s operation and maintenance. Learn more about household septic systems by exploring Extension's educational materials library or visiting the Onsite Wastewater Education Program.

This material is based upon work supported by the Cooperative State Research, Education, and Extension Service, U.S. Department of Agriculture, under special
project number 99-EWQI-1-0613.