For the purposes of this chapter:

1. "Department" means the department of environmental quality.

2. "Install" means to place or replace a part of an onsite waster treatment system, whether new or existing, to make it ready for use.

3. "License" means authorization by the department for an individual to engage in the business of installing an onsite wastewater treatment system.

4. "Onsite wastewater treatment system" means a wastewater treatment system or part thereof, serving a dwelling or building, or group thereof, which uses soil treatment and disposal. The term commonly may be known as a septic system.

5. "Permit" means authorization from a local public health unit or other political subdivision to install an onsite wastewater treatment system, in accordance with the specific site and rules adopted under this title.