(1) The department will determine whether a mixing zone is appropriate for a particular discharge during the department's permit, permit renewal, approval, order, or authorization review process pursuant to the rules in this subchapter. The department may determine that:

(a) no mixing zone shall be granted;

(b) the standard mixing zone applied for is appropriate;

(c) the source specific mixing zone applied for is appropriate; or

(d) an alternative or modified mixing zone, as defined by the department, is appropriate.

(2) A person applying to the department for a mixing zone must indicate the type of mixing zone applied for and supply sufficient detail for the department to make a determination regarding the authorization of the mixing zone under the rules of this subchapter.

(3) A source specific mixing zone may not be used unless approved by the department.

(4) In making a determination of nonsignificance under the rules in ARM Title 17, chapter 30, subchapter 7, a person may use a standard mixing zone without approval from the department or request that the department specifically designate a mixing zone, which may be either a standard or source specific mixing zone.

(5) Department determinations regarding mixing zones will be accomplished within the time frames required for the underlying permit, approval, or authorization, and the applicant will be notified of that determination according to those same requirements. In all other cases, department determinations will be made and the applicant notified within 30 days after receipt of a complete application.

(6) After receiving notification of the department's determination the applicant may:

(a) accept the department's determination;

(b) modify the proposed mixing zone and reapply; or

(c) appeal the department's decision pursuant to any applicable provision of law.

History: 75-5-301, MCA; IMP, 75-5-301, MCA; NEW, 1994 MAR p. 2136, Eff. 8/12/94; TRANS, from DHES, 1996 MAR p. 1499.