(1) Sand and gravel used in filter pack wells shall be
thoroughly hosed or sluiced with water, and shall be disinfected with a
solution containing at least 50 parts per million chlorine before being placed
in the well. All water introduced into a well during construction shall be
clean and potable. The well and its equipment, including the interior of the
well casing, shall be thoroughly swabbed and cleaned to remove all oil, grease,
and foreign substances upon completion of the well's construction. Following
the completion of a well, and again after the pumping equipment has been
installed, a well and its equipment shall be disinfected by thoroughly
agitating and mixing in the well a solution containing enough chlorine to leave
a residual of 25 parts per million throughout the well after a period of 24
(2) The responsibility for the chlorination of the well shall be agreed upon in writing by the parties
to the drilling agreement.
(3) The contractor shall clean and disinfect the drilling equipment after drilling in an area of known
or suspected contamination or areas of iron bacteria problems.