Section 327IAC2-11-8. Criteria for impaired drinking water class ground water

   Impaired drinking water class ground water, classified according to section 4(g) or 4(h) of this rule, shall meet the following requirements:

(1) A contaminant not identified in the classification as being in excess of the numeric criterion of section 6(a) or 6(d) of this rule shall meet the numeric criterion established in section 6(a) or 6(d) of this rule.

(2) A contaminant identified in the classification as being in excess of the numeric criterion established in section 6(a) or 6(d) of this rule shall meet the existing contaminant concentration if it is greater than the numeric criterion established in section 6(a) or 6(d) of this rule and results from a source of contamination that:

(A) was from a previously unregulated facility, practice, or activity;

(B) was discovered after those who caused the contamination abandoned the site and those who caused the contamination cannot be found; or

(C) cannot be identified due to the nature of the specific constituent.

(3) Any design standard or management requirements that apply to a facility, practice, or activity with impaired drinking water class ground water must be at least as stringent as the design standard and management requirements that would be applied to a facility, practice, or activity with drinking water class ground water.

(4) The commissioner may allow an appropriate site specific, risk based numeric criterion different from the numeric criterion established in this section to be applied to impaired drinking water class ground water at and beyond the boundary of the ground water management zone established according to section 9 of this rule.

(Water Pollution Control Division; 327 IAC 2-11-8; filed Feb 4, 2002, 11:00 a.m.: 25 IR 1881; readopted filed Jun 4, 2008, 11:07 a.m.: 20080702-IR-327080207BFA; readopted filed Jul 30, 2014, 4:04 p.m.: 20140827-IR-327140189BFA)