Get matched with top septic tank pros in Bigfork, MN

The purpose of a septic tank is to allow solid wastes to separate out of the wastewater using time, gravity, and other natural biological processes. If your septic tank is too small, it might be overwhelmed by solid waste and unable to accomplish this task—and if it’s far too large, there won’t be enough liquid in the tank to nurture the necessary bacteria to aid in the breakdown process.

How deep your septic system needs to be into the ground depends on several factors. In extremely cold environments, the tank needs to rest below the maximum frost line, which can be up to six or eight feet deep. The standard burying depth for most systems is between a few inches and four feet below ground level. Depth can also depend on the slope of the landscaping and other property variables. 

There are many reasons you may want to extend the depth of an existing well or drill a new, deeper well on your property. A deeper well can tap cleaner water sources—shallow water may contain more contaminants. With a deeper well, you’ll also have an easier time reaching the water table depth (the level at which underground water is found) and can get past tricky soil conditions. 

Plus, if your local building code requires a minimum well depth for safety and environmental standards, you’ll meet the code by digging a deeper well in the first place.

A septic tank riser should extend to just above the ground level or slightly above it. The exact height can vary depending on local regulations and personal preferences, but a common guideline is to have the riser's top flush with or no more than a few inches above the surrounding ground. This height allows for easy access to the septic tank without creating a tripping hazard or obstructing mowing and landscaping activities. It's essential to ensure that the riser lid is easily visible and accessible for regular maintenance and inspection while being mindful of safety and aesthetics.