The 2017 Stormwater Quality theme for the Summit County Communities for Clean Stormwater is “Lake Erie and the Ohio River Start Here-Don’t Waste Them.” One targeted source of “Waste” is leachate from septic tanks which is a major component of pollution and poor water quality.
Households that are not served by public sewers usually depend on septic tank systems to treat and dispose of wastewater. A well designed, installed and maintained septic system can provide years of reliable low-cost service. When these systems fail to operate effectively, property damage, groundwater and surface water pollution, and disease outbreaks can occur. Therefore, it makes good sense to understand and care for your septic tank system.
There are many different types of septic tank systems to fit a wide range of soil and site conditions. The following information will help you to understand a conventional gravity-flow septic tank system, and keep it operating safely at the lowest possible cost. A conventional gravity-flow septic tank system has three working parts:
- The septic tank.
- The drainfield with its replacement area.
- The surrounding soil.
The Septic Tank
The typical septic tank is a large buried rectangular or cylindrical container made of concrete, fiberglass, or polyethylene. Wastewater from your toilet, bath, kitchen, and laundry flows into the tank. Heavy solids settle to the bottom where bacterial action partially decomposes them to digested sludge and gases. Most of the lighter solids, such as fats and grease, rise to the top to form a scum layer.
Septic tanks may have one or two compartments.Two compartment tanks do a better job of settling solids and are required for new systems. Tees or baffles are provided at the tank’s inlet and outlet pipes. The inlet tee slows the incoming wastes and reduces the disturbance of the settled sludge. The outlet tee keeps the solids or scum in the tank. All tanks should have accessible covers for checking the condition of the baffles and for pumping both compartments. If risers extend from the tank to or above the ground surface, they should be secure to prevent accidental entry into the tank.
Soils that are not decomposed remain in the septic tank. If not removed by periodic pumping, solids will accumulate until they eventually overflow into the drainfield. Most septic tanks need to be pumped every three to five years, depending on the tank size and the amount and type of solids entering the tank.
“Early Warning” Levels Inside Your Septic Tank
The septic tank should be pumped when:
- The bottom of the scum layer is within 3 inches of the bottom of the outlet tee or baffle.
- The top of the sludge layer is within 12 inches of the bottom of the outlet fitting.
Some septic tank additives on the market with chemicals, yeast, bacteria, or enzymes claim to improve septic tank performance or reduce the need for routine pumping. Such products are not necessary for the proper functioning of a septic tank. Some can cause solids to carry over to the drainfield, which results in early soil clogging and the need for a new drainfield. Products containing organic solvents contribute to groundwater pollution.
The wastewater leaving the septic tank is a liquid called effluent. It has been partially treated but still contains disease-causing bacteria and other pollutants.
The drainfield receives septic tank effluent. It has a network of perforated pipes laid in gravel filled trenches (2-3 feet wide) or beds (up to 10 feet wide) in the soil. Wastewater trickles out of the pipes, through the gravel layer, and into the soil. The size and type of drainfield depends on the estimated daily wastewater flow and soil conditions.
Every new drainfield is required to have a designated replacement area. It must be maintained should the existing system need an addition or repair.
The soil below the drainfield provides the final treatment and disposal of the septic tank effluent. After the effluent has passed into the soil, most of it percolates downward and outward, eventually entering the groundwater. A small percentage is taken up by plants through their roots or evaporates from the soil.
The soil filters effluent as it passes through the pore spaces. Chemical and biological processes treat the effluent before it reaches groundwater, or a restrictive layer, such as hardpan, bedrock, or clay soils. These processes work best where the soil is somewhat dry, permeable, and contains plenty of oxygen for several feet below the drainfield.
Warning signs of a failure:
- Odors, surfacing sewage, wet spots or lush vegetation
- Pluming or septic tank backups
- Slow draining fixtures
- Gurgling sounds in the plumbing system
If you notice any of these signs or if you suspect your septic tank system may be having problems, contact your local health department for assistance. In Summit County, call 330-923-4891.
How to care for your septic system
Here are the Ten Essentials that you need to know to care for your Septic System.
- Practice water conservation. The more wastewater you produce, the more wastewater the soil must treat and dispose of. By reducing and balancing your use, you can extend the life of the drainfield, decrease the possibility of system failure, and avoid costly repairs.
To reduce your water use:
- Use water-saving devices.
- Repair leaky faucets and plumbing fixtures.
- Reduce toilet reservoir volume or flow.
- Take shorter showers.
- Take baths with a partially-filled tub.
- Wash only full loads of dishes and laundry.
- Keep accurate records. Know where your septic tank is and keep a diagram of its location. Keep a record of maintenance which will be helpful if problems occur and if you plan to sell your home.
- Inspect your system once a year. Check the sludge and scum levels inside your septic tank to assure that the layers of solids are not within the “early warning levels.” Check the tank to see if the baffles or tees are in good condition. Periodically inspect the drainfield and downslope areas for odors, wet spots, or surfacing sewage. If your drainfield has inspection pipes, check them to see if there is a liquid level continually over six inches since this may be an early indication of a problem.
- Pump out your septic tank when needed. Don’t wait until you have a problem. Routine pumping can prevent failures such as clogging of the drainfield and sewage backup into the home. Using a garbage disposal will increase the amount of solids entering the septic tank, requiring more frequent pumping.
- Never flush harmful materials into the septic tank. Grease, cooking oils, newspaper, paper towels, rags, coffee grounds, sanitary napkins, and cigarettes cannot easily decompose in the tank. Chemicals such as solvents, oils, paint and pesticides are harmful to the system’s proper operation and may pollute the groundwater. Septic tank additives are not necessary for the proper functioning of a septic tank, nor do they reduce the need for routine pumping.
- Keep all runoff away from your system. Water from surfaces such as roofs, driveways, or patios should be diverted away from the septic tank and drainfield area. Soil over your system should be slightly mounded to help surface water runoff.
- Protect your system from damage. Keep traffic such as vehicles, heavy equipment or livestock off your drainfield or replacement area. The pressure can compact the soil or damage pipes. Before you plant a garden, construct a building, or install a pool, check on the location of your system and replacement area.
- Landscape your system properly. Keep impermeable materials off your drainfield and replacement area. Materials such as concrete or plastic reduce evaporation and the supply of air to the soil for proper effluent treatment. These materials can hinder getting access to the system for pumping, inspection, or repair. Grass is the best cover for your system.
- Never enter any septic tank. Poisonous gases or the lack of air can be fatal. Any work on the tank should be done from the outside.
- Contact your local Soil and Water Conservation District. Check the Summit County Public Health Department for help with Septic System problems at 330-923-4891. Although some malfunctions may require complete drainfield replacement, many problems can be corrected with a minimum amount of cost and effort.