Will My Land “Perc?”

First of all, what is a septic system?

A septic system is installed when a public sewer line is not readily available. There are many different types of septic systems but most follow the same principle of moving sewage from the establishment, through a septic tank, to field lines installed in the ground. The field lines allow the effluent to transfer into the soil. The importance of a perc test is to determine the appropriate amount of soil that will effectively accomplish this transfer.

 

Will my land perc?

Every dirt “percs.” It is not necessarily a question of whether it will pass a percolation test but rather how suitable the soil is for the field lines of a septic system.

From a scale of 1 to 10, with 10 being the best:

Dirt that scores a 1-4 would need a septic mound constructed before it would be suitable area for septic field lines.

Dirt that scores a 5-8 would need a small amount of dirt added to the area in order to cover the field lines.

Dirt that scores a 9-10 would not require any dirt to be brought into the area. All of the necessary field lines could be installed into the soil.

North Alabama has a variety of dirt profiles that can change with the contour of the land, natural drainage, proximity to geological features, etc. These changes can occur within feet of each other. Therefore, one area of a piece of property may be more suitable than the next for a septic system.

 

What are my options?

A bad “perc test score” does not mean that the establishment is incapable of having a septic system. There are several options for each type of soil quality, as described below.

Conventional System:

This system requires no additional dirt to be brought into the area. The natural soil is of high enough quality that the field lines will be installed into the existing ground. This would be a score of a “9-10.”

Shallow Conventional:

This system is necessary when the soil is moderate. The field lines will be installed in the natural soil but will also require anywhere from 0 to 12 inches of soil added as cover. This would be a score of a “5-8.”

Engineered Design:

Engineered designed septic systems are required when the natural soil cannot support field lines. In this case, a septic mound or other alternative must be installed in which to transfer the effluent to the ground. Unfortunately, this is worst case scenario, with a score of a “1-4.”