Ark. Code Ann. § 8-4-213: Conclusiveness of commission actions

(a) If no appeal is taken from an order, a rule, or other decision of the Arkansas Pollution Control and Ecology Commission as provided in §§ 8-4-222 - 8-4-229 , or if the action of the commission is affirmed on appeal, then the action of the commission in the matter shall be deemed conclusive, and the validity and reasonableness thereof shall not be questioned in any other action or proceeding.

(b) However, this section shall not preclude the authority of the commission to modify or rescind its actions.