Septic Tanks - Preventative Routine Maintenance

Septic Tank Maintenance Tips

Follow these tips to keep your septic tank system running smoothly and save yourself money on repairs.

  • Have your septic system inspected every one to two years and cleaned (pumped out) every three to five years or more frequently, depending on the tank size and number of people using the system.
  • Never flush cat litter, coffee grounds, diapers, towelettes (even the'flushable' type), cigarette butts, tampons, condoms, grease, dental floss, baby wipes, paints, thinners, pesticides, oils, medicines, or excessive household chemicals.
  • Know your system's location. When you have the tank pumped, draw a diagram or map showing its location in relation to fixed points - corners of the house, steps, or fence posts. Ask the pumper to help you locate the drainfield. Note its location on your diagram, along with the location of your drinking water well. Keep this sketch with your septic tank records.
  • Place an easily movable item - a birdbath or decorative rock - over the tank lid to make it easy to find.
  • Protect the drainfield.
  • Add a barrier to prevent anyone from driving over the drainfield, which could break the tank lid and pipes and compact the soil, restricting oxygen flow. (Bacteria in the drainfield need oxygen.)
  • Divert down spouts and other surface water - especially irrigation sprinklers -away from the drainfield. Too much water can harm it.
  • Don't dig, build, or plant anything other than grass over the drainfield.
  • Conserve water. Reduce the amount of wastewater that must be treated and disposed of by your system:
  • Wash no more than one or two loads of clothes daily. Up to 53 gallons of water flood your septic system with each load, so it's best to spread laundry out over the week.
  • Fix leaky faucets and toilets; over time, they can send hundreds of extra gallons of water through your septic system.
  • Use low-flow fixtures and appliances whenever possible. Low-flush toilets use between 1 and 1.6 gallons of water per flush and may reduce your water bill by up to one-third. Low-flow faucet aerators on sink faucets. low-flow showerheads and low-flow washing machines will also save water.
  • Do not use a garbage disposal. It adds up to 50 percent more solids to your septic tank, and your tank will require more frequent pump-outs.
  • Do not use caustic drain openers for clogged drains. Use boiling water or a drain snake instead.
  • Make sure your water softener is not plumbed to wash back into the septic tank.
  • Keep good records, including a copy of your septic tank permit.
  • Do not use septic tank additives, commercial septic tank cleansers, yeast, sugar, etc. These products are not necessary and some may be harmful to your system.
  • Use commercial bathroom cleaners and laundry detergents in moderation. Try cleaning toilets, sinks, showers, and tubs with a mild detergent or baking soda.

Important Warning

Be extremely careful around open or exposed septic tanks. Falling into a septic tank can cause death from suffocation or drowning. Even leaning over a septic tank can cause you to collapse.

Pumping (Cleaning Out a Septic Tank)

Most home septic tanks require cleaning every three to five years.

Pumping is needed when solids fill from one-third to one-half of the tank. The only way to know when this occurs is to have your tank inspected by a septic contractor. The contractor will recommend pumping by a licensed septic pumper whenever:

The bottom of the scum (grease) layer is within 6 inches of the bottom of the outlet tee.
The top of the sludge layer is within 12 inches of the outlet tee.
After the tank is pumped, there is no need to "reseed" it. Seeding means to jumpstart good bacterial growth by adding things such as yeast, manure, or dead animals. DHEC doesn't recommend seeding the system because the simple act of using the system will provide all the bacteria necessary to make the system work well.

Yeast, manure, meat, and dead animals will not help develop the colony of bacteria in the tank any faster.

General Advice on Septic Tank Pumping Frequency

Tank Size Number of Residents Pumping Frequency
1,000 gallons 1 Every 12 years
  2 Every 6 years
  4 Every 3 years
  6 Every 2 years
  8 Every 1 year
1,250 gallons 1 Every 16 years
  2 Every 8 years
  4 Every 3 years
  6 Every 2 years
  8 Every 1 years
1,500 gallons 1 Every 9 years
  2 Every 4 years
  4 Every 3 years
  6 Every 2 years
  8 Every 1 year

Septic Tank Inspections

To prevent problems, have your septic system inspected every one to two years by a licensed septic tank contractor and follow his or her advice about how often to clean out the tank. Alternative septic systems that have mechanical parts such as a pump should be inspected at least once a year or more frequently as recommended by the manufacturer.

A septic tank contractor will:

  • Locate your septic system and uncover access holes
  • Open the inspection port to check that internal slabs or tees (baffles) are in good condition
  • If your system has an effluent filter, check it to see if it needs to be cleaned. (Some filters are equipped with alarm systems to alert the homeowner when the filter needs to be cleaned.)
  • Flush your toilets
  • Check for signs of sewage or wastewater backup
  • Measure scum and sludge layers
  • Identify any leaks
  • Inspect mechanical parts if there are any
  • Recommend tank cleaning (pumping) if needed
  • Check the ground over the drainfield for sogginess or ponding, which could indicate improper drainage, a clogged system, excessive water use. The contractor may recommend a drainfield inspection, a separate process.

For a more detailed explanation of the inspection process, read Septic Tank Inspection - What Should I Expect When I Have My Tank Inspected? (pdf) and Drainfield Inspection —Does My Drainfield Ever Need To Be Inspected? (pdf), both from the National Small Flows Clearinghouse (NSFC)