(1) The standards in ARM 17.30.1006 establish the maximum allowable changes in ground water quality and are the basis for limiting discharges to ground water.

(2) The ground water standards may be exceeded within a mixing zone established pursuant to applicable provisions in ARM Title 17, chapter 30, subchapter 5.

(3) It is not necessary to treat discharges to a purer condition than the natural condition of the receiving water, within the meaning of 75-5-306, MCA.

(4) The classifications of ground water are based on natural specific conductance as specified in ARM 17.30.1006.