Minn. Stat. § 115B.15: APPLICABILITY.

Sections 115B.01 to 115B.14 apply to any release or threatened release of a hazardous substance occurring on or after July 1, 1983, including any release which began before July 1, 1983, and continued after that date. Sections 115B.01 to 115B.14 do not apply to a release or threatened release which occurred wholly before July 1, 1983, regardless of the date of discovery of any injury or loss caused by the release or threatened release.