Septic System Care and Maintenance

The majority of private sewage disposal systems in DuPage County consist of a septic tank and a septic field. The septic tank removes solids from household wastewater. After the wastewater exits the tank it flows under the ground through a series of pipes to the gravel filled trenches of the septic field. Proper maintenance of a septic tank is important to the proper functioning of the septic field.

Baffles slow the flow of sewage as it passes through the tank. Heavier solids accumulate on the bottom while lighter solids rise to the surface. As the tank fills up with solid material, the wastewater passes through more quickly and solids have less time to settle. A tank full of solids will result in some solids exiting the tank along with the wastewater. Blockages can then occur in the pipes of the septic field and could cause sewage to surface on the ground. To prevent pipe blockages, a septic tank should be pumped out every 2 or 3 years. The condition of the septic tank baffles should be checked at the time of pumping.

The below picture is a side view of a septic tank showing solids accumulating in the tank through the course of several years. Below the tanks are cross-sections of septic field pipe with blockages forming due to a tank that is not pumped out often enough.

Water & Sewage - care - tanks

An additional concern with septic fields is the build up of biomat in the soil. Biomat consists of microorganisms and their waste products. It forms where the septic trench gravel and soil contact each other. A small amount of biomat is normal; however, if the wastewater contains solids, then the organisms in the biomat will feed on the increased amount of nutrients and the layer will thicken. As the biomat thickens, the flow of water out of the trench is slowed. The trench will fill and eventually the wastewater will surface to the ground. To protect your field against excessive biomat formation, pump the tank every 2 to 3 years.

The below picture is a side view of two septic trenches showing biomat growth. The top trench shows normal biomat growth. The bottom trench has thicker biomat growth and prevents the wastewater from draining into the soil.

Water & Sewage - care - trenches

Correction of these problems can be costly. Hydrojetting may remove pipe blockages, but a septic field repair or replacement is needed to correct a biomat problem. Hydrojetting will not remove a biomat build up. The following information can help prevent these problems.

Do not add excess water to your septic system. Water from sinks, toilets, baths, and laundry machines need to go to the septic system. Water from footing sumps, water softener discharges, furnace humidifiers and air conditioners should not drain into the septic system. Repair dripping faucets and running toilets. Attempt to limit laundry loads to 2 or less a day. Use water wisely.

Do not put unnecessary solids into the septic field. Diapers, sanitary napkins, condoms, cigarettes, paper towels, newspapers, and facial tissues do not decompose well and could fill the tank and clog the field pipes. If a garbage disposal is used, the tank will need more frequent cleaning. Improve drainage around your septic field area. Discharge sump pumps or downspouts away from this area. Do not install a sprinkling system in the field area. Excess surface water sitting over the field area will encourage the growth of biomat.

Avoid damaging the field area. Vehicle or construction traffic due to building projects or landscaping can damage the field. Placing a swimming pool or shed over the field can damage the field as well.

Water & Sewage - Homeowner Guide - field