Okla. Admin. Code § 252:4-7-2
The Uniform Environmental Permitting Act requires that DEQ licenses, permits, certificates, approvals and registrations fit into an application category, or Tier, established under the uniform environmental permitting rules. Tier I is the category for those things that are basically administrative decisions which can be made by a technical supervisor with no public participation except for the landowner. Tier II is the category for those permit applications that have some public participation (notice to the public, the opportunity for a public meeting and public comment), and the administrative decision is made by the Division Director. Tier III is the category for those permit applications that have extensive public participation (notice to the public, the opportunity for a public meeting and public comment, and the opportunity for an administrative evidentiary hearing), and the administrative decision is made by the Executive Director.
Okla. Admin. Code § 252:4-7-2