327 IAC 2-11-6 Criteria for drinking water class ground water

Sec. 6. (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.