Tenn. Code § 68-221-404
The commissioner may develop a program for the evaluation of new technologies for use in subsurface sewage disposal systems. In the program, the commissioner shall first evaluate written documentation and the available studies and literature for such products. If the commissioner is satisfied with the results of this initial review, then the commissioner may authorize certain numbers of systems using the technology to be installed on an experimental basis for a period of time. During this time, the commissioner may require that mechanisms be used to protect the public and the environment. In the commissioner's discretion, this may include restrictive covenants on the property, or manufacturer's warranties with certain terms, or financial assurance mechanisms, including, but not limited to, surety or performance bonds, letters of credit, or escrow deposits. The commissioner may set the fee for permits for such experimental systems in a manner that reflects the department's costs for oversight and evaluation, fees paid by other systems, and the number of experimental systems installed, notwithstanding any rules that set a specific fee for experimental systems, to the contrary.
T.C.A. § 68-221-404