By: Karen Mancl, Professor, Food, Agricultural and Biological Engineering and Brian Slater, Associate Professor, Environment and Natural Resources
Homes beyond the reach of a city sewer must treat and disperse wastewater on their lots. This household sewage treatment system requires regular care and maintenance just like other components of a home. A neglected system threatens public health and can result in financial losses to the property. In cities, a trained professional operator cares for the wastewater treatment system. For homes with household sewage treatment systems, the property owner is responsible for maintenance.
Household sewage treatment systems usually consist of a septic tank, a treatment system, and a dispersal system. The expected life of a properly maintained wastewater treatment system is around 20 years.
This fact sheet presents basic, regular maintenance required for all types of systems. Detailed information for an advanced treatment system or a complicated dispersal system can be obtained from the system installer or the local health department.
A homeowner can do three things to keep the system trouble-free and operating as designed for its full life span: conserve water, landscape carefully, and maintain the septic tank and its components.
Using less water is the best thing a homeowner can do to maintain the household sewage treatment system. Systems are designed to handle 50–60 gallons per person per day of household sewage for a residential home. Adding more water than the design load can result in system failure. The following techniques can be used to conserve water:
- Install water conserving fixtures such as low-flow shower heads and toilets, and front-loading washing machines.
- Repair water leaks such as dripping faucets and toilet valves that don’t seal.
- Space out water use. For example, avoid washing multiple loads of laundry on one day, and spread out bathing times throughout the day.
Since the household sewage treatment system is buried in the yard, even seemingly innocent landscape changes can damage the septic system. Mark the system location and be careful when making lot improvements. The following suggestions will help prolong the life of your system:
- Divert rainwater drainage away from the soil absorption system area. Downspouts, paved areas, and slopes can all deliver extra water to the area where the wastewater is being treated and dispersed. A typical septic system applies about 100 inches of extra water per year to a yard. This is in addition to the 40 inches per year of normal precipitation in Ohio.
- Keep pavement, decks, vehicles, heavy equipment, and other solid objects off of the soil absorption system area. Heavy objects can compact the soil and close up larger soil pores, which reduces the amount of water that can move through the soil. Access for maintenance and repair is also limited if the system is covered.
- Do not place additional soil fill over the system. Many of the system components are meant to be shallow to allow for air infiltration. If sewage is surfacing in the yard, covering it with fill does not work to solve the problem, and can actually make the situation worse. Surfacing sewage is a sign that the system is malfunctioning and needs repair or possible replacement.
Pump the Septic Tank and Clean the Filter
Septic tanks (Figure 1) are installed to separate and store solids from the sewage, which protects the soil and other treatment system components from clogging. If not maintained on a regular basis, solids can move out of the tank and cause system damage. Include the following septic tank maintenance:
- Pump the septic tank on a regular basis. Table 1 shows the estimated time for septic tank pumping for different sized tanks and families.
- Do not use biological or chemical additives in place of tank pumping. Sewage has adequate bacteria and enzymes, making additives unnecessary and in some cases harmful.
- Do not use a garbage disposal. The extra solids fill up the tank, increasing the cost and frequency of maintenance.
- Check the condition of the baffles or tees (Figure 1) when the tank is pumped. Baffles or tees are designed to improve the removal and retention of solids. They can crumble or fall off with time, or be accidentally damaged during pumping.
- If your tank is equipped with an effluent filter to help capture and retain solids, remove and clean it on a regular basis (6–12 months, depending on use). Use a hose to clean the filter, washing the solids back into the septic tank. If a hose is not available, a spray bottle of water with a drop or two of detergent can be used to clean off the filter (Figure 2). Cleaning a severely clogged filter may require a brush in a bucket of soapy water.
- Risers from the tank openings to the ground surface make future maintenance easier (Figure 1). Protect the tank lid from mower damage and replace broken lids. Always secure the lids to keep children and pets from accessing the tank.
- Never enter a septic tank. The septic tank produces toxic gases that can kill a person in a matter of minutes. If someone has accidentally fallen in, call 911 then put a fan on top of the tank to blow in fresh air.
|Table 1. Estimated Septic Tank Pumping Frequency (in Years) for Different Size Tanks (Note: If a garbage disposal is used, more frequent pumping is required.) (Mancl, K. 1984. Estimating Septic Tank Pumping Frequency. J. of the Environmental Engineering Division ASCE. 110(1):283-285.)
|Tank Size (gallons)
||Number of People in Household (Year-Round Residence)
|Figure 1. Septic tank cross section. Effluent filters are required on new installations. Older tanks may not have filters.
||Figure 2. Clean septic tank effluent filters every 6–12 months. Hold the filter over the tank opening and clean with hose or spray bottle. For heavily clogged filters, clean with a brush and soapy water.
Few homeowners are prepared to operate and maintain a wastewater treatment system. In Ohio, professional service providers can perform this service. The providers are registered with the local health department and must participate in annual continuing education. For most household sewage treatment systems, an annual inspection with a small amount of maintenance can avoid a total system failure that would necessitate expensive and inconvenient system replacement.