Minn. R. 4410.7920
DRILL HOLE CONSTRUCTION STANDARDS
A permittee shall comply with the following standards with respect to construction of a drill hole. A. Drill holes shall be constructed in such a fashion as to facilitate testing and prevent any contamination of aquifers. B. Drill holes not permanently abandoned within 30 days of completion must be constructed to meet the requirements of part 4727.1100 regarding temporary abandonment of exploratory borings, and the requirements of any federal statutes and regulations applicable to deep wells.