Montana Title 75. Environmental Protection § 75-11-508. Corrective action--petroleum mixing zones

(1) A corrective action plan prepared pursuant to 75-11-309 may include the use of a petroleum mixing zone, as defined in 75-11-503, in conjunction with the final remediation and resolution of a petroleum release.

(2) If a petroleum mixing zone is included in a corrective action plan, it may be established only when:

(3) The boundary of a petroleum mixing zone established in accordance with this section must be contained within the boundary of the property on which the petroleum release originated unless a recorded easement, a restrictive covenant, or another institutional control approved by the department on an adjoining property allows the petroleum mixing zone to extend onto the adjoining property.

(4) Monitoring of a petroleum mixing zone may not be required unless there is a unique, overriding, site-specific, impact-related reason to require monitoring.

(5) At the downgradient boundary of a petroleum mixing zone, the concentration of any petroleum constituent, including benzene, may not exceed a water quality standard adopted pursuant to 75-5-301.

(6) If a petroleum mixing zone is established and maintained:

(7) A corrective action plan approved by the department pursuant to 75-11-309 may be amended to include a petroleum mixing zone in accordance with this section, including a corrective action plan approved prior to April 15, 2011.