What to Know About Septic Installation and Maintenance

Before installing a septic system, here's what you need to know about system maintenance.

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Meet The Expert: Sara Heger is an instructor and researcher in the Onsite Sewage Treatment Program at the University of Minnesota. She offered Family Handyman the following information about installing and maintaining a septic system.

How to Hire a Septic Contractor

  • Contact your county zoning or septic permitting department. They’ll have a list of licensed contractors.
  • Get a referral from someone you know, and get references.
  • If possible, hire an installer who does both soil testing and septic installation. That shortens the timeline for septic installation. When the contractor already knows the soil specifics, they’ll need to do less homework. A case could also be made to get a design and then have several installers bid on the design. In some areas, the permitting authority or an engineer is required to do the design.

While percolation tests, or “perc tests,” are still in use, the trend is moving toward attaining a more detailed soil description. A soil description gives a more accurate picture of the soil’s absorption rate, helping design a system optimized for your location.

What Type of System Do You Need?

The soil test determines whether you can install a septic system or just a holding tank. What’s the difference?

  • Holding Tank: A holding tank stores waste until it needs to be pumped out. It has an alarm to let you know when it’s time. Don’t ignore that alarm.
  • Septic System: A typical, in-ground gravity septic system consists of a septic tank with lines running to a drain field. The septic tank may have a filter which removes particles down to 1/8-in., and directs the effluent to the drain field where the waste is treated and absorbed into the soil.

Advanced Treatment Systems

A small percentage of homes may need more than a septic tank prior to discharge of the wastewater to the soil.  Common options for advanced pretreatment are aerobic treatment units and media filters.

Mound systems can also work if your property has a high water table, really rocky soil, or soil that is too permeable or not permeable enough. This type of system treats and purifies wastewater in an above-ground mound before it enters the soil.

What Type of Tank Do You Need?

Your septic system needs an approved tank. Concrete is the most common, followed by polyethylene tanks. Twin-wall polyethylene tanks are strong and costly. Single-wall poly tanks are susceptible to collapse when they’re pumped out; they should be used only where lot line restrictions are so tight that a new tank can be placed only by collapsing it.

What About Maintenance?

Your drain field and system need monitoring and inspecting. Filters may need cleaning as often as every year, and the tank needs to be pumped out periodically. Ask your installer about the proper pumping schedule for your system.

A typical modern septic tank has three manhole covers: one to access the pump, one to access the filter and one to pump out the tank.

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What If Something Goes Wrong? 

If something goes wrong with a system that includes a pump, an alarm alerts you to the problem. If the alarm sounds, don’t just call any septic company for repair. Call the installer or the company that has regularly serviced the system. They know your system and may be able to diagnose the problem before they arrive, saving you time and money.

Your installer should provide you and the permitting authority a packet of info that details system maintenance, tank specifics, soil treatment specifics, and an as-built map of the system. This detail will be vital if the system installer/designer isn’t available for repair or maintenance.