How to care for a septic system

A septic system doesn't need daily attention, but it does need the right habits. The EPA's guidance boils down to four of them: get it inspected and pumped, go easy on water, watch what goes down the drain, and look after the drainfield.

Get it inspected and pumped

The EPA says a household system should be inspected by a septic service professional at least every three years. Its FAQ page puts it as every 1 to 3 years. Tanks are typically pumped every three to five years, but the real trigger is what's inside. The EPA says it's time to pump when:

• the bottom of the scum layer is within 6 inches of the bottom of the outlet,
• the top of the sludge layer is within 12 inches of the outlet, or
• sludge and scum make up more than 25 percent of the liquid depth.

Systems with float switches, pumps or other mechanical parts are different. The EPA says they generally need an inspection once a year, and recommends a service contract. Our pumping guide covers how to work out your own schedule.

Ask the professional to write down the sludge and scum levels at every visit, and keep those notes with your other septic records. If repairs come up, the EPA's advice is to have them done soon rather than waiting.

Use less water

Every gallon that goes down a drain ends up in the tank and then the drainfield. The EPA says one person can use as much as 70 gallons of water a day indoors, and a single leaky or running toilet can waste as much as 200 gallons a day. Fixing leaks is the quickest win.

A few changes the EPA suggests:

• Replace older toilets, which use 3.5 to 5 gallons a flush, with high-efficiency models that use 1.6 gallons or less. Toilets account for 25 to 30 percent of household water use.
• Fit faucet aerators and high-efficiency showerheads.
• Run the washing machine with full loads, or match the load size setting to the load.
• Spread laundry across the week instead of doing it all in one day.

Be careful what goes down the drain

The rule for toilets is short: flush only human waste and toilet paper. The EPA's list of things to keep out includes:

• cooking grease and oil
• non-flushable wipes, diapers and paper towels
• feminine hygiene products, condoms and dental floss
• cat litter, coffee grounds and cigarette butts
• medicines
• household chemicals such as gasoline, paint, pesticides and antifreeze

Sinks matter too. Never pour cooking oil or grease down the drain, and keep oil-based paints, solvents and large amounts of toxic cleaners out of it. For a clogged drain, the EPA says to skip chemical drain openers and use boiling water or a drain snake instead. Our drain cleaner guide has more options.

A garbage disposal adds food solids to the tank. The EPA advises limiting its use or avoiding it, and says a tank will need pumping more often if you use one.

Protect the drainfield

The drainfield, or leach field, is where the soil finishes treating the water, and it's easy to damage without noticing. The EPA advises that you:

• never park or drive on it
• plant trees at the distance a septic professional recommends, so roots stay out of the pipes
• send roof drains, sump pumps and other rainwater away from it
• check with a local designer or permitting authority before building anything on it
• never cover it with concrete, asphalt or another hard surface

What should grow there? The EPA suggests native grasses and ground cover rather than trees, shrubs or vegetable gardens, and Penn State Extension calls turf grass the safest choice. Our leach field maintenance guide goes further.

Do you need septic additives?

No. The EPA says additives are not necessary for a septic system to work properly on household wastewater, and that using them is not recommended. It warns specifically against additives made of organic solvents or strong alkali chemicals, which can harm the soil and groundwater. Regular pumping is the care that counts.

Know the warning signs

Good habits lower the risk of trouble, but they can't rule it out. Slow drains across the house, sewage odors, wet spots over the drainfield or sewage backing up indoors all need prompt attention. See the signs of a failing system, or use our symptom checker.

Quick answers

How often should a septic system be inspected?

The EPA says at least every three years for a typical household system. Its FAQ page says every 1 to 3 years. Systems with mechanical parts generally need a yearly check.

Can I use a garbage disposal with a septic system?

You can, but the EPA advises limiting it. Food waste adds solids, so the tank will need pumping more often.

Do I need to add anything to my septic tank?

No. The EPA says additives aren't necessary for a system treating household wastewater, and recommends against them.