Section 327IAC2-11-6. Criteria for drinking water class ground water

   (a) The following numeric criteria are health protective goals for untreated ground water used as drinking water and are the maximum permissible level of a contaminant in drinking water class ground water:

(1) The following are the numeric criteria for select inorganic contaminants:

Contaminant	Criterion (mg/l unless noted)1
Antimony	0.006
Arsenic	0.010
Asbestos	7 MFL2
Barium	2
Beryllium	0.004
Cadmium	0.005
Chromium (total)	0.1
Combined beta/photon emitters	4 mrem/yr3
Cyanide (free)	0.2
Fluoride	4
Gross alpha particle activity (including radium 226 but excluding radon and uranium)	15 pCi/L4
Lead	0.015
Mercury (inorganic)	0.002
Nitrate (as N)	10
Nitrite (as N)	1
Radium 226 and 228 (combined)	5 pCi/L
Selenium	0.05
Thallium	0.002
Notes:
1mg/l is milligrams per liter.
2MFL is million fibers per liter greater than 10 micrometers in length.
3mrem/yr is millirems per year.
4pCi/L is picocuries per liter.

(2) The following are the numeric criteria for select organic contaminants:

Table 6(a)(2)
Numeric Criteria for Organic Contaminants in Drinking Water Class Ground Water
Chemical Abstract Registry Numbers	Contaminant	Criterion (mg/l unless noted)
15972-60-8	Alachlor	0.002
1912-24-9	Atrazine	0.003
71-43-2	Benzene	0.005
50-32-8	Benzo(a)pyrene	0.0002
1563-66-2	Carbofuran	0.04
56-23-5	Carbon tetrachloride	0.005
57-74-9	Chlordane	0.002
94-75-7	2,4-D	0.07
75-99-0	Dalapon	0.2
103-23-1	Di(2-ethylhexyl)adipate	0.4
96-12-8	Dibromochloropropane (DBCP)	0.0002
95-50-1	Dichlorobenzene, 1,2-	0.6
106-46-7	Dichlorobenzene, 1,4-	0.075
107-06-2	Dichloroethane, 1,2-	0.005
75-35-4	Dichloroethylene, 1,1-	0.007
156-59-2	Dichloroethylene, cis-1,2-	0.07
156-60-5	Dichloroethylene, trans-1,2-	0.1
75-09-2	Dichloromethane or methylene chloride	0.005
78-87-5	Dichloropropane, 1,2-	0.005
117-81-7	Di(2-ethylhexyl)phthalate	0.006
88-85-7	Dinoseb	0.007
85-00-7	Diquat	0.02
145-73-3	Endothall	0.1
72-20-8	Endrin	0.002
100-41-4	Ethylbenzene	0.7
106-93-4	Ethylene dibromide (EDB)	0.00005
1071-83-6	Glyphosate	0.7
76-44-8	Heptachlor	0.0004
1024-57-3	Heptachlor epoxide	0.0002
118-74-1	Hexachlorobenzene	0.001
77-47-4	Hexachlorocyclopentadiene	0.05
58-89-9	Lindane (gamma-BHC)	0.0002
72-43-5	Methoxychlor	0.04
108-90-7	Monochlorobenzene	0.1
23135-22-0	Oxamyl (vydate)	0.2
87-89-5	Pentachlorophenol	0.001
1918-02-1	Picloram	0.5
1336-36-3	Polychlorinated biphenyls (PCBs)	0.0005
122-34-9	Simazine	0.004
100-42-5	Styrene	0.1
1746-01-6	2,3,7,8-TCDD (Dioxin)	0.00000003
127-18-4	Tetrachloroethylene	0.005
108-88-3	Toluene	1
8001-35-2	Toxaphene	0.003
93-72-1	2,4,5-TP (Silvex)	0.05
120-82-1	Trichlorobenzene, 1,2,4-	0.07
71-55-6	Trichloroethane, 1,1,1-	0.2
79-00-5	Trichloroethane, 1,1,2-	0.005
79-01-6	Trichloroethylene	0.005
75-01-4	Vinyl chloride	0.002
1330-20-7	Xylenes (total)	10

(3) A drinking water class numeric criterion may be added to the criteria established in this subsection if adopted according to IC 4-22-2 and IC 13-14-9.

  (b) An agency shall determine if further action is necessary to comply with the narrative criteria established in section 5 of this rule if the following indicator levels are exceeded in drinking water class ground water:

(1) Chloride at two hundred fifty (250) milligrams per liter.

(2) Sulfate at two hundred fifty (250) milligrams per liter.

(3) Total dissolved solids at five hundred (500) milligrams per liter.

(4) Total coliform bacteria at nondetect.

  (c) If the commissioner determines that a site-specific numeric criterion for a contaminant without a drinking water class numeric criterion established in subsection (a) is necessary to protect human health, any natural resource, or the environment, a risk analysis shall be used to establish a numeric criterion for that contaminant and must:

(1) receive approval from the commissioner; and

(2) be based upon appropriate toxicological data.

  (d) The naturally occurring concentration of a contaminant in drinking water class ground water shall be the numeric criterion if that contaminant occurs at a concentration greater than the drinking water numeric criterion established in subsection (a) or (c) or an indicator level established in subsection (b).

  (e) If drinking water class ground water at a facility, practice, or activity is determined to have one (1) or more contaminant concentrations above the numeric criteria established in this section that are not attributable to the facility, practice, or activity under consideration, an agency shall manage the facility, practice, or activity or implement programs such that:

(1) the facility, practice, or activity causes no further increase in the concentration of the contaminant determined to be above the numeric criterion established in this section; and

(2) any design standard or management requirements that apply to the facility, practice, or activity are at least as stringent as the design standard and management requirements that would be applied to a facility, practice, or activity where ground water does not have one (1) or more contaminant concentrations above the numeric criteria established in this section.

  (f) The commissioner may, for a ground water contamination assessment or remediation at a facility, practice, or activity under the jurisdiction of the department of environmental management, allow an appropriate site-specific, risk-based numeric criterion different from the numeric criterion established in subsection (a) or (d) to be applied to drinking water class ground water within the boundary of the ground water management zone established according to section 9 of this rule. (Water Pollution Control Division; 327 IAC 2-11-6; filed Feb 4, 2002, 11:00 a.m.: 25 IR 1879; readopted filed Jun 4, 2008, 11:07 a.m.: 20080702-IR-327080207BFA; filed Nov 24, 2008, 12:30 p.m.: 20081217-IR-327060280FRA; readopted filed Jul 30, 2014, 4:04 p.m.: 20140827-IR-327140189BFA)