Tennessee Code Title 7. Consolidated Governments and Local Governmental Functions and Entities § 7-51-2703

(a) A utility may provide reasonable construction and manufacturer's specifications for utility infrastructure to ensure that the infrastructure is constructed properly and with appropriate materials.  A utility that chooses to provide such specifications shall provide persons with a schedule of all approved materials for utility infrastructure with specifications for such materials.

(b) Notwithstanding subsection (a), a utility shall not require that materials or services for the construction of the utility infrastructure be provided by a specific vendor or manufacturer unless using the materials or services by a specific vendor or manufacturer is deemed necessary by the utility for the quality and integrity of the utility's system.