A riser is basically a connection that runs from your buried septic tank to a surface area of your yard, granting access to its interior. The tank themselves are normally buried, several feet underground, which helps eliminate the very real possibility of odor leakage. However, there are some serious drawbacks, for example not having access to the tank for cleaning and maintenance.
A septic riser enables a tank to be buried a few feet beneath the earth while simultaneously allowing easy access when it becomes necessary to pump out the tank or for a cleaning or inspection.
With no riser, you must dig out the septic tank’s top surface and then find the septic tank lid (the access point). It’s easier in the long run to have a riser installed with a lid.
Risers for septic tanks are generally found in three kinds of materials: