A properly designed septic system in Tennessee will provide years of trouble free service. An improperly designed one will cause nightmares in a week. In an effort to prevent this, the State of Tennessee has regulations and restrictions that must be adhered to even before a septic system is even installed, since nobody likes to wake up in the morning to the smell of effluent bubbling to the surface.
Application For Permit Requirement
According to the state of Tennessee Department of Environment and Conservation, before a septic system is installed, an Application for a Septic Permit is required. The permit is obtained at your local municipality's building or code enforcement department. When you apply for a permit, an entire series of actions is undertaken. First, a qualified geologist or civil engineer surveys the site, runs a percolation test (a test to determine suitability of the soil), and designs the system. If the land will not support a septic system, the building department may offer guidance as to what options are available.
Water Table Restriction
There is a water table restriction that will prevent the issuance of a permit. First, the natural water table must be at least 4 feet below the surface of the leach field. This means that if the leach pipes are buried, for example, 3 feet below the surface, then the water table must be 4 feet below that, or 7 feet below grade (top of the field).
Lot Size Restriction
There is a lot size restriction as well. The lot must be sufficiently big enough to support a leach field, and have enough area available for a duplicate leach field, if another field has to be installed later on. Without this area requirement, a permit for installation cannot be issued.
Grade Slope Restriction
If the slope of the grade is 30% (1 foot of drop per every 3 feet of run), and the possibility exists of effluent bubbling to the surface, then a permit cannot be issued. For slopes 50% (1 foot of drop per every foot of run)or greater, no septic system is permitted. The Geologist or Civil Engineer doing the testing will issue a final determination on this.
Public Sewer Restriction
If there is a public sewage system available to be tied into, then the State of Tennessee will not issue a permit for a septic system. There are no exceptions to this regulation.