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Priority Pollutants / 307(a) Toxics
Priority pollutants are a set of chemical pollutants we regulate, and for which we have developed analytical test methods. (There are also analytical test methods for additional analytes not included in this list.) We originally developed a list of 65 toxic pollutants as part of a settlement agreement with the National Resources Defense Council (NRDC), to be included in section 307(a) of the Clean Water Act (40 CFR Part 401.15)
In the late 1970s we identified the specific chemicals contained within each of the classes of chemicals on the 307(a) list using a set of five criteria, including the frequency of occurrence of the compound in water and the availability of chemical standards. The resulting list of 129 pollutants became known as the "Priority Pollutants List." Three of those chemicals have since been removed for a variety of reasons: 17. bis(chloromethyl) ether; 49. trichlorofluoromethane; and 50. dichlorodifluoromethane. The original numbering system was retained for the remaining pollutants. The current list of 126 Priority Pollutants, shown below, can be found in Appendix A to 40 CFR Part 423.
- 001 Acenaphthene
- 002 Acrolein
- 003 Acrylonitrile
- 004 Benzene
- 005 Benzidine
- 006 Carbon tetrachloride
- 007 Chlorobenzene
- 008 1,2,4-trichlorobenzene
- 009 Hexachlorobenzene
- 010 1,2-dichloroethane
- 011 1,1,1-trichloreothane
- 012 Hexachloroethane
- 013 1,1-dichloroethane
- 014 1,1,2-trichloroethane
- 015 1,1,2,2-tetrachloroethane
- 016 Chloroethane
- 018 Bis(2-chloroethyl) ether
- 019 2-chloroethyl vinyl ethers
- 020 2-chloronaphthalene
- 021 2,4,6-trichlorophenol
- 022 Parachlorometa cresol
- 023 Chloroform
- 024 2-chlorophenol
- 025 1,2-dichlorobenzene
- 026 1,3-dichlorobenzene
- 027 1,4-dichlorobenzene
- 028 3,3-dichlorobenzidine
- 029 1,1-dichloroethylene
- 030 1,2-trans-dichloroethylene
- 031 2,4-dichlorophenol
- 032 1,2-dichloropropane
- 033 1,2-dichloropropylene
- 034 2,4-dimethylphenol
- 035 2,4-dinitrotoluene
- 036 2,6-dinitrotoluene
- 037 1,2-diphenylhydrazine
- 038 Ethylbenzene
- 039 Fluoranthene
- 040 4-chlorophenyl phenyl ether
- 041 4-bromophenyl phenyl ether
- 042 Bis(2-chloroisopropyl) ether
- 043 Bis(2-chloroethoxy) methane
- 044 Methylene chloride
- 045 Methyl chloride
- 046 Methyl bromide
- 047 Bromoform
- 048 Dichlorobromomethane
- 051 Chlorodibromomethane
- 052 Hexachlorobutadiene
- 053 Hexachlorocyclopentadiene
- 054 Isophorone
- 055 Naphthalene
- 056 Nitrobenzene
- 057 2-nitrophenol
- 058 4-nitrophenol
- 059 2,4-dinitrophenol
- 060 4,6-dinitro-o-cresol
- 061 N-nitrosodimethylamine
- 062 N-nitrosodiphenylamine
- 063 N-nitrosodi-n-propylamine
- 064 Pentachlorophenol
- 065 Phenol
- 066 Bis(2-ethylhexyl) phthalate
- 067 Butyl benzyl phthalate
- 068 Di-N-Butyl Phthalate
- 069 Di-n-octyl phthalate
- 070 Diethyl Phthalate
- 071 Dimethyl phthalate
- 072 benzo(a) anthracene
- 073 Benzo(a)pyrene
- 074 Benzo(b) fluoranthene
- 075 Benzo(b) fluoranthene
- 076 Chrysene
- 077 Acenaphthylene
- 078 Anthracene
- 079 Benzo(ghi) perylene
- 080 Fluorene
- 081 Phenanthrene
- 082 Dibenzo(,h) anthracene
- 083 Indeno (1,2,3-cd) pyrene
- 084 Pyrene
- 085 Tetrachloroethylene
- 086 Toluene
- 087 Trichloroethylene
- 088 Vinyl chloride
- 089 Aldrin
- 090 Dieldrin
- 091 Chlordane
- 092 4,4-DDT
- 093 4,4-DDE
- 094 4,4-DDD
- 095 Alpha-endosulfan
- 096 Beta-endosulfan
- 097 Endosulfan sulfate
- 098 Endrin
- 099 Endrin aldehyde
- 100 Heptachlor
- 101 Heptachlor epoxide
- 102 Alpha-BHC
- 103 Beta-BHC
- 104 Gamma-BHC
- 105 Delta-BHC
- 106 PCB–1242 (Arochlor 1242)
- 107 PCB–1254 (Arochlor 1254)
- 108 PCB–1221 (Arochlor 1221)
- 109 PCB–1232 (Arochlor 1232)
- 110 PCB–1248 (Arochlor 1248)
- 111 PCB–1260 (Arochlor 1260)
- 112 PCB–1016 (Arochlor 1016)
- 113 Toxaphene
- 114 Antimony
- 115 Arsenic
- 116 Asbestos
- 117 Beryllium
- 118 Cadmium
- 119 Chromium
- 120 Copper
- 121 Cyanide, Total
- 122 Lead
- 123 Mercury
- 124 Nickel
- 125 Selenium
- 126 Silver
- 127 Thallium
- 128 Zinc
- 129 2,3,7,8-TCDD