### Comparison of EPA’s 2015 Final Updated Human Health AWQC a nd Previous AWQC June 2015

1 Pollutant CAS No. 2015 EPA Human Health AWQC for the Consumption of Previous EPA Human Health AWQC for the Consumption of Water + Organism (μg/L) Organism Only (μg/L) Water + Organism (μg/L) O rganism Only (μg/L) 1,1,1 - Trichloroethane 71 - 55 - 6 10,000 200,000 * --- 1,1,2,2 - Tetrachloroethane 79 - 34 - 5 0.2 3 0.17 4 1,1,2 - Trichloroethane 79 - 00 - 5 0.55 8.9 0.59 16 1,1 - Dichloroethylene 75 - 35 - 4 300 20,000 330 7,100 1,2,4,5 - Tetrachlorobenzene 95 - 94 - 3 0.03 0.03 0.97 1.1 1,2,4 - Trichlorobenzene 120 - 82 - 1 0.071 0.076 35 70 1,2 - Dichlorobenzene 95 - 50 - 1 1,000 3,000 420 1,300 1,2 - Dichloroethane 107 - 06 - 2 9.9 650 0.38 37 1,2 - Dichloropropane 78 - 87 - 5 0.90 31 0.5 15 1,2 - Diphenylhydrazine 122 - 66 - 7 0.03 0.2 0.036 0.2 1,3 - Dichlorobenzene 541 - 73 - 1 7 10 320 960 1,3 - Dichloropropene 542 - 75 - 6 0.27 12 0.34 21 1,4 - Dichlorobenzene 106 - 46 - 7 300 900 63 190 2,4,5 - Trichlorophenol 95 - 95 - 4 300 600 1,800 3,600 2,4,6 - Trichlorophenol 88 - 06 - 2 1.5 2.8 1.4 2.4 2,4 - Dichlorophenol 120 - 83 - 2 10 60 77 290 2,4 - Dimethylphenol 105 - 67 - 9 100 3,000 380 850 2,4 - Dinitrophenol 51 - 28 - 5 10 300 69 5,300 2,4 - Dinitrotoluene 121 - 14 - 2 0.049 1.7 0.11 3.4 2 - Chloronaphthalene 91 - 58 - 7 800 1,000 1,000 1,600 2 - Chlorophenol 95 - 57 - 8 30 800 81 150 2 - Methyl - 4,6 - Dinitrophenol 534 - 52 - 1 2 30 13 280 3,3' - Dichlorobenzidine 91 - 94 - 1 0.049 0.15 0.021 0.028 3 - Methyl - 4 - Chlorophenol 59 - 50 - 7 500 2,000 * * Acenaphthene 83 - 32 - 9 70 90 670 990 Acrolein 107 - 02 - 8 3 400 6 9

### Comparison of EPA’s 2015 Final Updated Human Health AWQC a nd Previous AWQC June 2015

2 Pollutant CAS No. 2015 EPA Human Health AWQC for the Consumption of Previous EPA Human Health AWQC for the Consumption of Water + Organism (μg/L) Organism Only (μg/L) Water + Organism (μg/L) O rganism Only (μg/L) Acrylonitrile 107 - 13 - 1 0.061 7.0 0.051 0.25 Aldrin 309 - 00 - 2 0.00000077 0.00000077 0.000049 0.00005 alpha - Hexachlorocyclohexane (HCH) 319 - 84 - 6 0.00036 0.00039 0.0026 0.0049 alpha - Endosulfan 959 - 98 - 8 20 30 62 89 Anthracene 120 - 12 - 7 300 400 8,300 40,000 Benzene 71 - 43 - 2 0.58 - 2.1 16 - 58 0.61 - 2.2 14 - 51 Benzidine 92 - 87 - 5 0.00014 0.011 0.000086 0.0002 Benzo(a)anthracene 56 - 55 - 3 0.0012 0.0013 0.0038 0.018 Benzo(a)pyrene 50 - 32 - 8 0.00012 0.00013 0.0038 0.018 Benzo(b)fluoranthene 205 - 99 - 2 0.0012 0.0013 0.0038 0.018 Benzo(k)fluoranthene 207 - 08 - 9 0.012 0.013 0.0038 0.018 beta - Hexachlorocyclohexane (HCH) 319 - 85 - 7 0.0080 0.014 0.0091 0.017 beta - Endosulfan 33213 - 65 - 9 20 40 62 89 Bis(2 - Chloro - 1 - Methylethyl) Ether 108 - 60 - 1 200 4,000 1,400 65,000 Bis(2 - Chloroethyl) Ether 111 - 44 - 4 0.030 2.2 0.03 0.53 Bis(2 - Ethylhexyl) Phthalate 117 - 81 - 7 0.32 0.37 1.2 2.2 Bis(Chloromethyl) Ether 542 - 88 - 1 0.00015 0.017 0.0001 0.00029 Bromoform 75 - 25 - 2 7.0 120 4.3 140 Butylbenzyl Phthalate 85 - 68 - 7 0.10 0.10 1,500 1,900 Carbon Tetrachloride 56 - 23 - 5 0.4 5 0.223 1.6 Chlordane 57 - 74 - 9 0.00031 0.00032 0.0008 0.00081 Chlorobenzene 108 - 90 - 7 100 800 130 1,600 Chlorodibromomethane 124 - 48 - 1 0.80 21 0.4 13 Chloroform 67 - 66 - 3 60 2,000 5.7 470 Chlorophenoxy Herbicide (2,4 - D) 94 - 75 - 7 1,300 12,000 100 --- Chlorophenoxy Herbicide (2,4,5 - TP) [Silvex] 93 - 72 - 1 100 400 10 ---

### Comparison of EPA’s 2015 Final Updated Human Health AWQC a nd Previous AWQC June 2015

3 Pollutant CAS No. 2015 EPA Human Health AWQC for the Consumption of Previous EPA Human Health AWQC for the Consumption of Water + Organism (μg/L) Organism Only (μg/L) Water + Organism (μg/L) O rganism Only (μg/L) Chrysene 218 - 01 - 9 0.12 0.13 0.0038 0.018 Cyanide 57 - 12 - 5 4 400 140 140 Dibenzo(a,h)anthracene 53 - 70 - 3 0.00012 0.00013 0.0038 0.018 Dichlorobromomethane 75 - 27 - 4 0.95 27 0.55 17 Dieldrin 60 - 57 - 1 0.0000012 0.0000012 0.000052 0.000054 Diethyl Phthalate 84 - 66 - 2 600 600 17,000 44,000 Dimethyl Phthalate 131 - 11 - 3 2,000 2,000 270,000 1,100,000 Di - n - Butyl Phthalate 84 - 74 - 2 20 30 2,000 4,500 Dinitrophenols 25550 - 58 - 7 10 1,000 69 5,300 Endosulfan Sulfate 1031 - 07 - 8 20 40 62 89 Endrin 72 - 20 - 8 0.03 0.03 0.059 0.06 Endrin Aldehyde 7421 - 93 - 4 1 1 0.29 0.3 Ethylbenzene 100 - 41 - 4 68 130 530 2,100 Fluoranthene 206 - 44 - 0 20 20 130 140 Fluorene 86 - 73 - 7 50 70 1,100 5,300 gamma - Hexachlorocyclohexane (HCH) 58 - 89 - 9 4.2 4.4 0.98 1.8 Heptachlor 76 - 44 - 8 0.0000059 0.0000059 0.000079 0.000079 Heptachlor Epoxide 1024 - 57 - 3 0.000032 0.000032 0.000039 0.000039 Hexachlorobenzene 118 - 74 - 1 0.000079 0.000079 0.00028 0.00029 Hexachlorobutadiene 87 - 68 - 3 0.01 0.01 0.44 18 Hexachlorocyclohexane (HCH) - Technical 608 - 73 - 1 0.0066 0.010 0.0123 0.0414 Hexachlorocyclopentadiene 77 - 47 - 4 4 4 40 1,100 Hexachloroethane 67 - 72 - 1 0.1 0.1 1.4 3.3 Indeno(1,2,3 - cd)pyrene 193 - 39 - 5 0.0012 0.0013 0.0038 0.018 Isophorone 78 - 59 - 1 34 1,800 35 960 Methoxychlor 72 - 43 - 5 0.02 0.02 100 ---

### Comparison of EPA’s 2015 Final Updated Human Health AWQC a nd Previous AWQC June 2015

4 Pollutant CAS No. 2015 EPA Human Health AWQC for the Consumption of Previous EPA Human Health AWQC for the Consumption of Water + Organism (μg/L) Organism Only (μg/L) Water + Organism (μg/L) O rganism Only (μg/L) Methyl Bromide 74 - 83 - 9 100 10,000 47 1,500 Methylene Chloride 75 - 09 - 2 20 1,000 4.6 590 Nitrobenzene 98 - 95 - 3 10 600 17 690 Pentachlorobenzene 608 - 93 - 5 0.1 0.1 1.4 1.5 Pentachlorophenol 87 - 86 - 5 0.03 0.04 0.27 3 Phenol 108 - 95 - 2 4,000 300,000 10,000 860,000 p,p' - Dichlorodiphenyldichloroethane (DDD) 72 - 54 - 8 0.00012 0.00012 0.00031 0.00031 p,p' - Dichlorodiphenyldichloroethylene (DDE) 72 - 55 - 9 0.000018 0.000018 0.00022 0.00022 p,p' - Dichlorodiphenyltrichloroethane (DDT) 50 - 29 - 3 0.000030 0.000030 0.00022 0.00022 Pyrene 129 - 00 - 0 20 30 830 4,000 Tetrachloroethylene (Perchloroethylene) 127 - 18 - 4 10 29 0.69 3.3 Toluene 108 - 88 - 3 57 520 1,300 15,000 Toxaphene 8001 - 35 - 2 0.00070 0.00071 0.00028 0.00028 trans - 1,2 - Dichloroethylene (DCE) 156 - 60 - 5 100 4,000 140 10,000 Trichloroethylene (TCE) 79 - 01 - 6 0.6 7 2.5 30 Vinyl Chloride 75 - 01 - 4 0.022 1.6 0.025 2.4 *AWQC for this chemical were not provided in EPA’s previous update .