ARSD 74:54:01:04. Standards for groundwater of 10,000 mg/L TDS concentration or less

The following standards are the allowable pH range and maximum allowable concentration in groundwater of 10,000 mg/L TDS concentration or less for the contaminants specified unless the ambient condition exceeds the standards. Regardless of whether there is one contaminant or more than one contaminant present in groundwater, when the ambient pH or concentration of any water contaminant exceeds the standard specified in this section, the ambient pH or concentration is the allowable limit, provided that the discharge at such concentrations will not result for the present or the reasonably foreseeable future in concentrations at any place of groundwater withdrawal in excess of the standards in this section. These standards apply to the dissolved portion of the contaminants specified, with the exception of mercury and the organic compounds, using the definition of "dissolved" given in the publication Methods and Guidance for the Analysis of Water, Version 2, June 1999. The standards for mercury and the organic compounds apply to the total unfiltered concentrations of the contaminants. Groundwater must meet the standards listed as follows unless otherwise provided by chapters 74:54:01 and 74:54:02: Human Health Standards CONTAMINANT CAS NUMBER CONCENTRATION ORGANICS Alachlor 15972-60-8 0.002 mg/L Aldicarb 116-06-3 0.003 mg/L Aldicarb Sulfone 1646-87-4 0.002 mg/L Aldicarb Sulfoxide 1646-87-3 0.004 mg/L Atrazine 1912-24-9 0.003 mg/L Benzene 71-43-2 0.005 mg/L Benzo[a]pyrene 50-32-8 0.0002 mg/L Cabofuran 1563-66-2 0.04 mg/L Carbon tetrachloride 56-23-5 0.005 mg/L Chlordane 57-74-9 0.002 mg/L 2,4-D (2,4-dichlorophenoxyacetic acid) 94-75-7 0.07 mg/L Dalapon (sodium salt) 75-99-0 0.2 mg/L Di(2-ethylhexyl)adipate 103-23-1 0.4 mg/L Di(2-ethylhexyl)phthalate 117-81-7 0.006 mg/L Dibromochloropropane (DBCP) 96-12-8 0.0002 mg/L o-Dichlorobenzene 95-50-1 0.6 mg/L p-Dichlorobenzene 106-46-7 0.075 mg/L 1,2-Dichloroethane 107-06-2 0.005 mg/L 1,1-Dichloroethylene 75-35-4 0.007 mg/L cis 1,2-Dichloroethylene 156-59-2 0.07 mg/L trans 1,2-Dichloroethylene 156-60-5 0.1 mg/L Dichloromethane (Methylene chloride) 75-09-2 0.005 mg/L 1,2 Dichloropropane 78-87-5 0.005 mg/L Dinoseb 88-85-7 0.007 mg/L Diquat 85-00-7 0.02 mg/L Endothall 145-73-3 0.1 mg/L Endrin 72-20-8 0.002 mg/L Ethylbenzene 100-41-4 0.7 mg/L Ethylene dibromide (EDB) 106-93-4 0.00005 mg/L Glyphosate 1071-53-6 0.7 mg/L Heptachlor 76-44-8 0.0004 mg/L Heptachlor epoxide 1024-57-3 0.0002 mg/L Hexachlorobenzene 188-74-1 0.001 mg/L Hexachlorocyclopentadiene 77-47-4 0.05 mg/L Total Haloacetic Acids, including: Dichloroacetic acid 76-43-6 Monochloroacetic acid 79-11-8 0.06 mg/L Trichloroacetic acid 76-03-9 Lindane 58-89-9 0.0002 mg/L Methoxychlor 72-43-5 0.04 mg/L Monochlorobenzene 108-90-7 0.1 mg/L Oxamyl (Vydate) 23135-22-0 0.2 mg/L Pentachlorophenol 87-86-5 0.001 mg/L Picloram 1918-02-1 0.5 mg/L Polychlorinated biphenyls (PCBs) 1336-36-3 0.0005 mg/L Simazine 122-34-9 0.004 mg/L Styrene 100-42-5 0.1 mg/L 2,3,7,8-TCDD (Dioxin) 1746-01-6 0.00000003 mg/L (3 x 10-8 mg/L) Tetrachloroethylene (PCE) 127-18-4 0.005 mg/L Toluene 108-88-3 1 mg/L Total petroleum hydrocarbons NA 10 mg/L1 Toxaphene 8001-35-2 0.003 mg/L 2,4,5-TP Silvex 93-72-1 0.05 mg/L 1,2,4-Trichlorobenzene 120-82-1 0.07 mg/L 1,1,1-Trichloroethane 71-55-6 0.2 mg/L 1,1,2-Trichloroethane 79-00-5 0.005 mg/L Total trihalomethanes, including: bromodichloromethane, 75-27-4 bromoform (tribromomethane), 75-25-2 0.08 mg/L chloroform (trichloromethane), 67-66-3 and dibromochloromethane 124-48-1 (chlorodibromomethane) Trichloroethylene 79-01-6 0.005 mg/L Vinyl chloride 75-01-4 0.002 mg/L Xylenes (total) 1330-20-7 10 mg/L INORGANICS Antimony 7440-36-0 0.006 mg/L Arsenic 7440-38-2 0.01 mg/L2 Asbestos 1332-21-4 7 MFL (longer than 10 micrometers) Barium 7440-39-3 2 mg/L Beryllium 7440-41-7 0.004 mg/L Bromate 7789-38-0 0.01 mg/L Cadmium (Cd) 7440-43-9 0.005 mg/L Chlorite 7758-19-2 1 mg/L Chromium 7440-47-3 0.1 mg/L Copper (Cu) 7440-50-8 1.0 mg/L Cyanide (CN) as free cyanide 143-33-9 0.2 mg/L Cyanine (CN) as weak acid dissociable 143-33-9 0.75 mg/L Fluoride (F) 7681-49-4 4 mg/L Lead (Pb) 7439-92-1 0.015 mg/L Mercury (Hg) 7487-94-7 0.002 mg/L Nitrate (as N) 14797-55-8 10 mg/L Nitrite (as N) 14797-65-0 1 mg/L Nitrate + Nitrite (both as N) NA 10 mg/L Selenium 7782-49-2 0.05 mg/L Silver 7440-22-4 0.1 mg/L Thallium 7440-28-0 0.002 mg/L RADIONUCLIDES Beta particle and photon radioactivity (from man-made radionuclides) NA 4 mrem/yr Gross alpha particle activity, excluding radon and uranium NA 15 pCi/l Radium 226 & radium 228 combined 7440-14-4 5 pCi/l Radon 10043-92-2 300 pCi/l Uranium 7440-61-1 0.03 mg/L MICROBIOLOGY Fecal coliform bacteria NA Less than 2.2 organisms per 100 mL (MPN) 1 If Total Petroleum Hydrocarbons is between 0.1 mg/L and 10 mg/L, and is within the radius of influence of a well or within Zone A of a delineated wellhead protection area, clean up must continue until 0.1 mg/L is met. Total petroleum hydrocarbons must be analyzed using the California Department of Health Services Method published in "Leaking Underground Fuel Tank Field Manual: Guidelines for Site Assessment, Cleanup, and Underground Storage Tank Closure," October 1989, or its equivalent. 2 Ground Water Discharge Plans with permitted allowable limits for arsenic issued before the effective date of these ground water quality standard revisions are exempt. Other standards that are not applicable to groundwater receiving discharge from publicly owned treatment works. CONTAMINANT CAS NUMBER CONCENTRATION Chloride 7647-14-5 250 mg/L pH NA 6.5-8.5 Sulfate 7757-82-6 500 mg/L TDS NA 1000 mg/L If the standards in either table one or table two are exceeded by ambient groundwater quality, the ambient water quality becomes the maximum allowable limit, as determined in § 74:54:02:18, for an approved groundwater discharge plan.