Authority: IC 13-18-3-1; IC 13-18-4-1; IC 13-18-4-3; IC 13-18-4-4; IC 13-18-4-5; IC 13-18-17-5

Affected: IC 4-22-2; IC 13-18-4; IC 13-18-17; IC 13-22; IC 13-23; IC 13-24; IC 13-25-4; IC 13-25-5-8.5; IC 13-30

Sec. 2. (a) The following agencies shall adopt rules under IC 4-22-2 to apply the standards established in this rule to the facilities, practices, and activities they regulate:

1. (1) The department of environmental management.
2. (2) The department of natural resources.
3. (3) The Indiana state department of health.
4. (4) The state chemist of the state of Indiana.
5. (5) The office of the state fire marshal.

(b) An agency shall use its regulatory authority when adopting rules to ensure the criteria established in sections 5, 6, 7, and 8 of this rule will not be exceeded in ground water at or beyond the boundary of a ground water management zone established according to section 9 of this rule. When adopting rules, an agency shall, to the extent consistent with its regulatory authority, ensure that facilities, practices, and activities are designed and managed to eliminate or minimize, to the extent feasible, potential adverse impacts to the existing ground water quality by applying preventative action levels, design standards, a monitoring framework, or other regulatory methods. An agency may consider technological and economic reasonableness and other appropriate factors in determining a feasible approach.

(c) The standards established in this rule shall not limit nor expand the authority of an agency.

(d) The standards established in this rule shall allow the following to be consistent with the remediation objectives set forth in IC 13-25-5-8.5:

1. (1) Ground water remediations conducted under:

   1. (A) IC 13-22;
   2. (B) IC 13-23; or
   3. (C) IC 13-25-5.

2. (2) Ground water remediations that:

   1. (A) are not emergency or nontime-critical activities; and

   2. (B) are conducted under:

      1. (i) IC 13-24; or
      2. (ii) IC 13-25-4.
3. (3) Ground water remediations conducted under any other provision of IC 13, as appropriate.

(e) No person shall cause the ground water in a drinking water supply well to have a contaminant concentration that creates one (1) or more of the following:

1. (1) An exceedance of the numeric criteria established for drinking water class ground water in Tables [section] 6(a)(1) and 6(a)(2) of this rule.
2. (2) A level sufficient to be acutely or chronically toxic, carcinogenic, mutagenic, teratogenic, or otherwise injurious to human health based on best scientific information.

3. (3) An exceedance of one (1) or more of the following indicator levels:

   1. (A) Chloride at two hundred fifty (250) milligrams per liter.
   2. (B) Sulfate at two hundred fifty (250) milligrams per liter.
   3. (C) Total dissolved solids at five hundred (500) milligrams per liter.
   4. (D) Total coliform bacteria at nondetect.
4. (4) Renders the well unuseable for normal domestic use.

(f) No person shall cause the ground water in a nondrinking water supply well, including an industrial, commercial, or agricultural supply well, to have a contaminant concentration that, based on best scientific information, renders the well unuseable for its current use.

(g) The criteria established in subsections (e) and (f) are immediately enforceable on the effective date of this rule under IC 13-30 to protect ground water quality in water supply wells.

(h) Except as provided in subsection (g), the criteria established in this rule shall not be enforceable under IC 13-30 until subsequent rules are adopted to apply the standards established in this rule pursuant to subsections (a) and (b).

(Water Pollution Control Division; 327 IAC 2-11-2; filed Feb 4, 2002, 11:00 a.m.: 25 IR 1876; readopted filed Jun 4, 2008, 11:07 a.m.: 20080702-IR-327080207BFA; readopted filed Jul 30, 2014, 4:04 p.m.: 20140827-IR-327140189BFA; readopted filed May 27, 2020, 11:52 a.m.: 20200624-IR-327200186BFA; readopted filed Oct 18, 2024, 1:57 p.m.: 20241113-IR-327230810RFA)