§ 54.1-2301 provides specific statutory authority related to licensure of soil evaluators, alternative system installers and alternative system operators. Subsection D. (e) further requires the Board to create at least two classes of evaluators, one of which is to be conventional. However, the enabling statute is silent on the creation of classes for the installer or operator license.

The Board's authority is specifically related to licensure of individuals as authorized (soil evaluator, alternative installer or alternative operator). There is no statutory authority for the further division of the installer or the operator into multiple classes. The division of these two licenses into classes is not a criterion for licensure as provided for in D.(f).

Therefore, the subdivision of the two licenses into “journeyman” and “master” classification is not expressly authorized by the statute and exceeds the Board's authority.