Minn. R. 7500.1400
Drill holes must be sufficiently large to admit freely the insertion of a cartridge of explosives.
Tamping must be done only with wood or approved plastic rods without exposed metal parts, but nonsparking metal connectors may be used for jointed poles. Violent tamping must be avoided.
Only holes that will be fired in the next round of blasting may be loaded. After loading, the remaining explosives must be immediately returned to an authorized location.
Drilling must not be started until the remaining butts of old holes are examined with a wooden stick for unexploded charges. If unexploded charges are found, they must be refired before work proceeds.
No person is allowed to deepen drill holes which contain explosives.
Minn. R. 7500.1400
Statutory Authority: MS s 299F.71 to 299F.83