altered, modified, or changed by the board for particular common sources of
supply, the following rules apply to drilling wells with rotary tools.
(1) Suitable and safe
surface casing must be used in all wells. Sufficient surface casing must be run
to reach a depth below all fresh water located at levels reasonably accessible
for agricultural and domestic use. Surface casing must be set in or through an
impervious formation and must be cemented by the pump-and-plug or
displacement method with sufficient cement to circulate to the top of the well.
If it becomes necessary to run a production string, such string must be
cemented by the pump-and-plug method or any other method approved by the
board administrator and must be properly tested by the pressure method before
cement plugs are drilled.
(2) All cemented casing
strings shall stand under pressure until the cement has reached a compressive strength
of 300 pounds per square inch; provided, however, that no tests shall be
commenced until the cement has been in place for at least 8 hours. The
requirement "under pressure" as used herein will be complied with if
one float valve is used or if pressure is otherwise held.
(3) Blowout prevention
equipment must be installed and maintained on all wells in accordance with the
requirements of ARM 36.22.1014.
drilling fluid or air must be used when drilling the surface hole prior to setting
surface casing and when drilling through freshwater aquifers anywhere within
the state of Montana.