As of August 30, 2024 there are 10,047 active septic systems in McLean County. In McLean County, a typical septic system consists of a septic tank followed by either a seepage field or a sand filter. A septic system is a very simple design and has about four major steps in its process. First, all water runs out of your house through one main sewer line into the septic tank. Next, the wastewater is held long enough to allow solids to settle down to the bottom (sludge) and oil and grease float to the top (scum). The wastewater between the sludge and the scum is then discharged into the drain field. Finally, waste water percolates into the soil, naturally removing harmful coli-form bacteria, viruses, and nutrients.
A septic system fails over time because suspended solids are washed out of the septic tank by wastewater being discharged. These small solids plug up spaces between soil particles in seepage field trench walls and between the sand in the sand filter. There are many signs of a failing septic system. The first sign can be a strong odor coming from your drains and toilets with gurgling and slow drainage. Other signs of failure include wastewater backing up into household drains, which include the sludge and scum, bright green spongy grass on the drain field even during dry weather, and pooling water or muddy soil with a strong sewage odor around your septic system or in your basement.
There are several easy ways to go about preventing these types of disasters with the proper maintenance. One of the first things you can do is check to make sure that everything draining to the septic system has tight connections and operates correctly. Secondly, you will want to measure your sludge and scum layers in the tank (if you are unsure how to do this you will need professional help). Finally, exteriorly and interiorly inspect the tank for damage. During the inspections, further maintenance may have to be conducted, such as pumping the tank. This is typically done every 3-5 years, but pumping periodically is the best way to keep the system functioning.
To keep the system functioning at full capacity there are other things to also avoid, such as additives. There are around 1,200 different products containing enzymes and yeast, and research has shown some of these products can cause damage to the system. Garbage disposals also increase the accumulation of solids in the tank. Prevent heavy trucks or equipment from driving over the septic system, and do not build over it. Soaps and detergents in moderation should be the golden rule because overuse can kill the good bacteria in the septic tank. Use toilet paper designed to break down quickly in the septic tank. Avoid flushing cigarettes, paper towels, sanitary napkins, tampons, condoms, “flushable” wipes, and disposable diapers. Finally, one of the most important things is to minimize water usage—the more water used, the more frequently you will have to conduct maintenance and pumping. Laundry should be spread out across the week and not done all on one day.
There are many reasons to keep a maintained septic system; most importantly it saves you money. Maintenance on a septic system will cost $300-$500 every 3-5 years but replacing a system costs $15,000-35,000. Maintaining your septic system will protect your property value. This also keeps you and your neighbors healthy and helps protect the environment.
For more information on proper septic system maintenance and resources including lists of licensed septic system installers or tank pumpers, contact the McLean County Health Department’s Environmental Health Division at (309) 888-5483.
