Alaska Administrative Code
Title 18 - Environmental Conservation
Chapter 75 - Oil and Other Hazardous Substances Pollution Control
Article 3 - Discharge Reporting, Cleanup, and Disposal of Oil and Other Hazardous Substances
18 AAC 75.345 - Groundwater and surface water cleanup levels
Current through February 27, 2024
(a) Except as otherwise provided in this section, cleanup of a discharge or release of a hazardous substance to groundwater or surface water must meet the requirements of this section.
(b) Contaminated groundwater must meet
TABLE C. GROUNDWATER CLEANUP LEVELS |
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Hazardous Substance |
CAS Number1 |
Health effect that drives risk; carcinogen (ca) noncarcinogen (nc); mutagen (m) |
Groundwater Human Health Cleanup Level2 (micrograms/liter) |
Acenaphthene |
83-32-9 |
nc |
530 |
Acenaphthylene3 |
208-96-8 |
nc |
260 |
Acetone |
67-64-1 |
nc |
14000 |
Aldrin |
309-00-2 |
ca |
0.0092 |
Ammonium Perchlorate |
7790-98-9 |
nc |
14 |
Anthracene |
120-12-7 |
nc |
434 |
Antimony (metallic) |
7440-36-0 |
nc |
7.8 |
Arsenic, Inorganic3 |
7440-38-2 |
ca |
0.52 |
Barium |
7440-39-3 |
nc |
3800 |
Benz[a]anthracene |
56-55-3 |
m |
0.12 |
Benzaldehyde |
100-52-7 |
nc |
1900 |
Benzene |
71-43-2 |
ca |
4.6 |
Benzo[a]pyrene |
50-32-8 |
m |
0.034 |
Benzo[b]fluoranthene |
205-99-2 |
m |
0.34 |
Benzo[g,h,i]perylene3 |
191-24-2 |
nc |
0.264 |
Benzo[k]fluoranthene |
207-08-9 |
m |
0.804 |
Benzoic Acid |
65-85-0 |
nc |
75000 |
Benzyl Alcohol |
100-51-6 |
nc |
2000 |
Beryllium and compounds |
7440-41-7 |
nc |
25 |
Bis(2-chloroethyl)ether |
111-44-4 |
ca |
0.14 |
Bis(2-ethylhexyl)phthalate |
117-81-7 |
ca |
56 |
Bromobenzene |
108-86-1 |
nc |
62 |
Bromodichloromethane |
75-27-4 |
ca |
1.3 |
Bromoform |
75-25-2 |
ca |
33 |
Bromomethane |
74-83-9 |
nc |
7.5 |
Butadiene, 1,3 - |
106-99-0 |
ca |
0.18 |
Butanol, N- |
71-36-3 |
nc |
2000 |
Butyl Benzyl Phthalate |
85-68-7 |
ca |
160 |
Butylbenzene, n- |
104-51-8 |
nc |
1000 |
Butylbenzene, sec- |
135-98-8 |
nc |
2000 |
Butylbenzene, tert- |
98-06-6 |
nc |
690 |
Cadmium (Diet) |
7440-43-9 |
nc |
9.2 |
Carbon Disulfide |
75-15-0 |
nc |
810 |
Carbon Tetrachloride |
56-23-5 |
ca |
4.6 |
Chlordane |
12789-03-6 |
ca |
0.20 |
Chlordecone (Kepone) |
143-50-0 |
ca |
0.035 |
Chloroaniline, p- |
106-47-8 |
ca |
3.7 |
Chlorobenzene |
108-90-7 |
nc |
78 |
Chloroform |
67-66-3 |
ca |
2.2 |
Chloromethane |
74-87-3 |
nc |
190 |
Chloronaphthalene, Beta- |
91-58-7 |
nc |
750 |
Chlorophenol, 2- |
95-57-8 |
nc |
91 |
Chromium(Ill), Insoluble Salts6 |
16065-83-1 |
nc |
22000 |
Chromium(VI)6 |
18540-29-9 |
m |
0.35 |
Chrysene |
218-01-9 |
m |
2.04 |
Copper |
7440-50-8 |
nc |
800 |
Cresol, m- |
108-39-4 |
nc |
930 |
Cresol, o- |
95-48-7 |
nc |
930 |
Cresol, p- |
106-44-5 |
nc |
1900 |
Cumene |
98-82-8 |
nc |
450 |
Cyanide (CN-) |
57-12-5 |
nc |
1.5 |
Cyclohexane |
110-82-7 |
nc |
13000 |
DDD |
72-54-8 |
ca |
0.32 |
DDE, p,p'- |
72-55-9 |
ca |
0.46 |
DDT |
50-29-3 |
ca |
2.3 |
Dibenz[a,h]anthracene |
53-70-3 |
m |
0.034 |
Dibenzofuran |
132-64-9 |
nc |
7.9 |
Dibromochloromethane |
124-48-1 |
ca |
8.7 |
Dibromoethane, 1,2- (Ethylene Dibromide) |
106-93-4 |
ca |
0.075 |
Dibromomethane (Methylene Bromide) |
74-95-3 |
nc |
8.3 |
Dibutyl Phthalate |
84-74-2 |
nc |
900 |
Dichlorobenzene, 1,2- |
95-50-1 |
nc |
300 |
Dichlorobenzene, 1,3-3 |
541-73-1 |
nc |
300 |
Dichlorobenzene, 1,4- |
106-46-7 |
ca |
4.8 |
Dichlorobenzidine, 3,3'- |
91-94-1 |
ca |
1.3 |
Dichlorodifluoromethane |
75-71-8 |
nc |
200 |
Dichloroethane, 1,1- |
75-34-3 |
ca |
28 |
Dichloroethane, 1,2- |
107-06-2 |
ca |
1.7 |
Dichloroethylene, 1,1- |
75-35-4 |
nc |
280 |
Dichloroethylene, 1,2-cis- |
156-59-2 |
nc |
36 |
Dichloroethylene, 1,2-trans- |
156-60-5 |
nc |
360 |
Dichlorophenol, 2,4- |
120-83-2 |
nc |
46 |
Dichlorophenoxy Acetic Acid, 2,4- |
94-75-7 |
nc |
170 |
Dichloropropane, 1,2- |
78-87-5 |
ca |
4.4 |
Dichloropropene, 1,3- |
542-75-6 |
ca |
4.7 |
Dieldrin |
60-57-1 |
ca |
0.018 |
Diethyl Phthalate |
84-66-2 |
nc |
15000 |
Dimethylphenol, 2,4- |
105-67-9 |
nc |
360 |
Dimethylphthalate3 |
131-11-3 |
nc |
16000 |
Dinitrobenzene, 1,2- |
528-29-0 |
nc |
1.9 |
Dinitrobenzene, 1,3- |
99-65-0 |
nc |
2.0 |
Dinitrobenzene, 1,4- |
100-25-4 |
nc |
2.0 |
Dinitrophenol, 2,4- |
51-28-5 |
nc |
39 |
Dinitrotoluene, 2,4- |
121-14-2 |
ca |
2.4 |
Dinitrotoluene, 2,6- |
606-20-2 |
ca |
0.49 |
Dinitrotoluene, 2-Amino-4,6- |
35572-78-2 |
nc |
39 |
Dinitrotoluene, 4-Amino-2,6- |
19406-51-0 |
nc |
39 |
Dioxane, 1,4- |
123-91-1 |
ca |
4.6 |
Diphenylamine |
122-39-4 |
nc |
310 |
Endosulfan |
115-29-7 |
nc |
100 |
Endrin |
72-20-8 |
nc |
2.3 |
Ethyl Chloride |
75-00-3 |
nc |
21000 |
Ethylbenzene |
100-41-4 |
ca |
15 |
Ethylene Glycol |
107-21-1 |
nc |
40000 |
Fluoranthene |
206-44-0 |
nc |
2604 |
Fluorene |
86-73-7 |
nc |
290 |
Formaldehyde |
50-00-0 |
ca |
4.3 |
Heptachlor |
76-44-8 |
ca |
0.014 |
Heptachlor Epoxide |
1024-57-3 |
ca |
0.014 |
Hexachlorobenzene |
118-74-1 |
ca |
0.098 |
Hexachlorobutadienc |
87-68-3 |
nc |
1.4 |
Hexachlorocyclohexane, Alpha- |
319-84-6 |
ca |
0.072 |
Hexachlorocyclohexane, Beta- |
319-85-7 |
ca |
0.25 |
Hexachlorocyclohexane, Gamma- (Lindane) |
58-89-9 |
ca |
0.42 |
Hexachlorocyclopentadiene |
77-47-4 |
nc |
0.41 |
Hexachloroethane |
67-72-1 |
ca |
3.3 |
Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) |
121-82-4 |
ca |
7.0 |
Hexane, N- |
110-54-3 |
nc |
1500 |
Hexanone, 2- |
591-78-6 |
nc |
38 |
Hydrazine |
302-01-2 |
ca |
0.011 |
lndeno [1,2,3-cd]pyrene |
193-39-5 |
m |
0.194 |
Isophorone |
78-59-1 |
ca |
780 |
Isopropanol |
67-63-0 |
nc |
410 |
Lead and Compounds7 |
7439-92-1 |
nc |
15 |
Mercuric Chloride3 |
7487-94-7 |
nc |
5.7 |
Mercury (elemental) |
7439-97-6 |
nc |
0.52 |
Methanol |
67-56-1 |
nc |
20000 |
Methoxychlor |
72-43-5 |
nc |
37 |
Methyl Ethyl Ketone (2-Butanone) |
78-93-3 |
nc |
5600 |
Methyl Isobutyl Ketone (4-methyl-2-pentanone) |
108-10-1 |
nc |
6300 |
Methyl Mercury |
22967-92-6 |
nc |
2.0 |
Methyl tert-Butyl Ether (MTBE) |
1634-04-4 |
ca |
140 |
Methylene Chloride |
75-09-2 |
nc |
110 |
Methylnaphthalene, 1- |
90-12-0 |
ca |
11 |
Methylnaphthalene, 2- |
91-57-6 |
nc |
36 |
Naphthalene |
91-20-3 |
ca |
1.7 |
Nickel Soluble Salts |
7440-02-0 |
nc |
390 |
Nitrobenzene |
98-95-3 |
ca |
1.4 |
Nitroglycerin |
55-63-0 |
nc |
2.0 |
Nitroguanidine |
556-88-7 |
nc |
2000 |
Nitrosodimethylamine, N- |
62-75-9 |
m |
0.0011 |
Nitroso-di-N-propylamine, N- |
621 -64-7 |
ca |
0.11 |
Nitrosodiphenylamine, N- |
86-30-6 |
ca |
120 |
Nitrotoluene, m- |
99-08-1 |
nc |
1.7 |
Nitrotoluene, o- |
88-72-2 |
ca |
3.1 |
Nitrotoluene, p- |
99-99-0 |
nc |
43 |
Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) |
2691-41-0 |
nc |
1000 |
Octyl Phthalate, di-N- |
117-84-0 |
nc |
224 |
Pentachlorophenol |
87-86-5 |
ca |
0.41 |
Pentaerythritol tetranitrate (PETN) |
78-11-5 |
nc |
39 |
Perfluorooctane Sulfonate (PFOS) 29 |
1763-23-1 |
nc |
0.40 |
Perfluorooctanoic Acid (PFOA) 29 |
335-67-1 |
nc |
0.40 |
Phenanthrene-3 |
85-01-8 |
nc |
170 |
Phenol |
108-95-2 |
nc |
5800 |
Phosphorus, White |
7723-14-0 |
nc |
0.40 |
Polychlorinated Biphenyls (PCBs) |
1336-36-3 |
ca |
0.50 |
Propyl benzene |
103-65-1 |
nc |
660 |
Pyrene |
129-00-0 |
nc |
120 |
Selenium |
7782-49-2 |
nc |
100 |
Silver |
7440-22-4 |
nc |
94 |
Styrene |
100-42-5 |
nc |
1200 |
TCDD, 2,3,7,8-8 |
1746-01-6 |
ca |
1.2 x 10-6 |
Tetrachloroethane, 1, 1, 1,2- |
630-20-6 |
ca |
5.7 |
Tetrachloroethane, 1,1,2.2- |
79-34-5 |
ca |
0.76 |
Tetrachloroethylene |
127-18-4 |
nc |
41 |
Tetryl (Trinitrophenylmethylnitramine) |
479-45-8 |
nc |
39 |
Thallium (Soluble Salts) |
7440-28-0 |
nc |
0.20 |
Toluene |
108-88-3 |
nc |
1100 |
Toxaphene |
8001-35-2 |
ca |
0.71 |
Trichloro- 1,2,2-trifluoroethane, 1, 1,2- |
76-13-1 |
nc |
55000 |
Trichlorobenzene, 1,2,3- |
87-61-6 |
nc |
7.0 |
Trichlorohenzenc, 1,2,4- |
120-82-1 |
nc |
4.0 |
Trichloroethane, 1,1,1- |
71-55-6 |
nc |
8000 |
Trichloroethane, 1,1,2- |
79-00-5 |
nc |
0.41 |
Trichloroethylene |
79-01-6 |
nc |
2.8 |
Trichlorofluoromethane |
75-69-4 |
nc |
5200 |
Trichlorophenol, 2,4,5- |
95-95-4 |
nc |
1200 |
Trichlorophenol, 2,4,6- |
88-06-2 |
nc |
12 |
Trichlorophenoxyacetic Acid, 2,4,5- |
93-76-5 |
nc |
160 |
Trichlorophenoxypropionic acid, -2,4,5 |
93-72-1 |
nc |
110 |
Trichloropropane, 1,2,3- |
96-18-4 |
m |
0.0075 |
Trimethylbenzene, 1,2,4- |
95-63-6 |
nc |
15 |
Trimethylbenzene, 1,3,5- |
108-67-8 |
nc |
120 |
Tri-n-butyltin |
688-73-3 |
nc |
3.7 |
Trinitrobenzene, 1,3,5- |
99-35-4 |
nc |
590 |
Trinitrololueue, 2,4,6- |
1 18-96-7 |
nc |
9.8 |
Vanadium and Compounds |
7440-62-2 |
nc |
86 |
Vinyl Acetate |
108-05-4 |
nc |
410 |
Vinyl Chloride |
75-01-4 |
ca |
0.19 |
Xylenes |
1330-20-7 |
nc |
190 |
Zinc and Compounds |
7440-66-6 |
nc |
6000 |
PETROLEUM HYDROCARBONS |
|||
C6-C10 GRO |
nc |
2200 |
|
C10-C25 DRO |
nc |
1500 |
|
C25-C36 RRO |
nc |
1100 |
Notes to Table C:
(c) The department will set a more stringent cleanup level than the applicable level under (b) of this section, if the department determines that a more stringent cleanup level is necessary to ensure protection of human health, safety, or welfare, or of the environment, and based on actual onsite and actual or likely offsite uses of the groundwater that are likely to be affected by the hazardous substance. In making a determination under this subsection, the department may consider.
(d) Where the department determines that toxicity information is insufficient to establish a cleanup level for a hazardous substance or a pollutant that ensures protection of human health, safely, and welfare, and of the environment, the department may require a responsible person to provide an alternative source of drinking water for the affected parties or implement other institutional controls under 18 AAC 75.375 until a cleanup level is established under (b)(2), (3), or (4) of this section.
(e) Toxic substances in sediment may not cause, and may not be reasonably expected to cause, a toxic or other deleterious effect on aquatic life, except as authorized under 18 AAC 70. For purposes of this subsection, "toxic subslances" has the meaning given in 18 AAC 70.990.
(f) The point of compliance where groundwater cleanup levels must be attained is throughout the site from each point extending vertically from the uppermost level of the zone of saturation to the lowest possible depth that could potentially be affected by the discharge or release of a hazardous substance, unless the department approves an alternative point of compliance as part of the cleanup action under 18 AAC 75.360. For the department to approve an alternative point of compliance under this subsection, the
(g) Groundwater that is closely connected hydrologically lo nearby surface water may not cause a violation of the water quality standards in 18 AAC 70 for surface water or sediment. The department will, in consultation with local, state, and federal officials and the public, establish points of compliance with this subsection, taking into account
(h) If the groundwater point of compliance is established at or near a property boundary or if groundwater is closely connected hydrologically to a surface waterbody, the department will, if the department determines that sentinel monitoring is necessary to ensure protection of human health, safety, or welfare, or the environment, require a responsible person to develop sentinel monitoring wells that monitor for any hazardous substances likely to migrate to the applicable point of compliance at concentrations that exceed the cleanup levels.
(i) The department will require long-term monitoring if the department determines that monitoring is necessary to ensure protection of human health, safety, or welfare, or of the environment and if groundwater, surface water, soil, or sediment contains residual concentrations of a hazardous substance that exceed the applicable cleanup levels. If long-term monitoring is required under this subsection, a responsible person shall submit a plan and schedule for monitoring as part of the requirements for cleanup operations under 18 AAC 75.360. Unless otherwise approved by the department, a responsible person shall conduct monitoring quarterly for at least one year to establish the concentration trend. The department will evaluate the monitoring program yearly. If the monitoring indicates that the concentration trend
(j) The department will require groundwater, surface water, soil, or sediment monitoring to estimate contaminant flux rates and to address potential bioaccumulation of each hazardous substance at the site, if the department determines that monitoring is necessary to ensure protection of human health, safety, or welfare, or of the environment. If monitoring is required under this subsection, a responsible person shall submit a plan and schedule for monitoring as part of the cleanup operation requirements under 18 AAC 75.360.
(k) Groundwater monitoring wells must be installed, developed, and decommissioned in accordance with an approved method that is protective of human health, safety, and welfare, and of the environment.
(l) For a cleanup conducted under (b)(1) of this section, a chemical that is detected at one-tenth or more of the Table C value must be included when calculating cumulative risk under 18 AAC 75.325(g).
Standard Methods for the Examination of Water and Wastewater, adopted by reference in 18 AAC 75.345, may be purchased from the American Water Works Association at http://www.awwa.org/store.aspx or by contacting the organization at service@awwa.org or (800) 926-7337. The document also may be viewed at the department's Anchorage, Fairbanks, Juneau, and Soldotna offices.
Authority:AS 46.03.020
AS 46.03.050
AS 46.03.710
AS 46.03.740
AS 46.03.745
AS 46.04.020
AS 46.04.070
AS 46.09.010
AS 46.09.020