Septic tanks don’t require a lot of maintenance as long as you avoid flushing harmful chemicals and non-biodegradable items down the drain or toilet.
However, you do need to ensure you are pumping the septic tank regularly. According to the EPA, septic tanks should be pumped about once every three to five years to keep the septic system healthy and operating as intended.
How often the septic system needs to be pumped varies depending on several key factors, including the septic tank size, the size of the household, and the average water usage.
We asked experts to find out exactly how often you should pump your septic tank.
Meet the Expert
Josh Mitchell is a professional plumbing technician and owner of the plumbing-centered website PlumbingLab.com where he and his team offer plumbing advice, reviews, and helpful guides to tackle DIY plumbing projects.
How Does a Septic System Work?
Septic systems are designed to handle a substantial amount of waste from the household.
“The septic tank is a passive filtration system that separates waste into three layers,” says Josh Mitchell, Plumbing Technician and Owner of PlumbingLab.com.” Bacteria in the tank break down some of the waste, but over time, sludge and scum build up, requiring manual removal.”
When wastewater flows into the septic tank from the house, any heavy solids sink to the bottom of the tank where they form a sludge layer. Light waste, such as oil or grease, float on the top to form a scum layer, while the middle layer is made up of liquid waste called effluent that is released into the drain field for further filtration and decomposition.
The naturally-occurring bacteria and microorganisms inside the tank use a process known as anaerobic digestion to help decompose the solid waste, reducing the volume of sludge and scum.
If the tank is not pumped about once every three to five years, the sludge and scum will eventually build up to the point that the septic system stops working properly.
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How Often Should You Pump Your Septic Tank?
Typically, the average septic tank should be pumped out once every three to five years, but the specific frequency of septic tank pumping depends on a variety of key factors, including the size of the household, average water use, septic tank size, and more.
Household Size
The more people there are living in a single house or using a shared septic tank, the more waste there is to collect, separate, filter, and decompose.
“A 1,000-gallon tank in a home with two people can last up to five years before needing to be pumped, while the same tank with a four-person household might need pumping every three years,” Mitchell says.
Average Water Usage
The amount of water that the home uses also contributes to the frequency of septic tank pumping.
“Large families or homes with heavy water usage (like frequent laundry or long showers) may need more frequent attention,” Mitchell says.
So even if the household is relatively small, if water usage is excessive, you may need to pump the tank more frequently than a similarly sized household with more conservative water usage habits.
Septic Tank Size
Larger tanks are capable of holding more waste before the accumulation of sludge and scum can impact the operation of the septic system, which is why it’s necessary to find out the exact size of your septic system.
“If you’re unsure, a professional inspection every one to two years can help you decide,” Mitchell says.
Septic System Condition
Relatively new and well-maintained septic systems won’t need to be pumped as frequently as old, neglected septic tanks that have had the overall capacity reduced by sludge and scum.
Type of Waste
Septic systems are made to handle regular household waste, but if you dump cleaning chemicals down the drain this can impact the septic system operation.
“Avoid flushing non-biodegradable items (wipes, sanitary products) or pouring grease down drains, as they can clog the system,” Mitchell says.
How to Maintain a Septic Tank
Homeowners need to keep up with septic system maintenance to ensure the tank remains healthy and the filtration process is not impeded by the build up of sludge and scum.
- Regular inspections help to identify problems early and may be required by law depending on where you live.
- Reduce household water usage to lessen the burden on the septic system.
- Divert water from downspouts, driveways, patios, and sump pumps away from the septic tank and drain field.
- Address septic system problems as soon as possible to reduce the risk of minor issues becoming major repairs.
- Avoid driving vehicles or heavy equipment over the septic tank and drain field to prevent damage to the septic system.
- Use septic-safe cleaning products and only flush biodegradable items down the drain or toilet.
