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Contaminant Candidate List (CCL) and Regulatory Determination

Contaminant Candidate List 1 - CCL 1

On March 2, 1998, EPA announced the first Drinking Water Contaminant Candidate List (CCL 1). On July 18, 2003, the Agency announced its formal decision on whether to develop regulations for contaminants on the first CCL.

On this page:

Microbial Contaminant Candidates

  • Acanthamoeba
  • Adenoviruses
  • Aeromonas hydrophila
  • Caliciviruses
  • Coxsackieviruses
  • Cyanobacteria (blue-green algae), other freshwater algae, and their toxins
  • Echoviruses
  • Helicobacter pylori
  • Microsporidia (Enterocytozoon & Septata)
  • Mycobacterium avium intracellulare (MAC)

Chemical Contaminant Candidates

Chemical Contaminant CASRN1
1,1,2,2-tetrachloroethane 79-34-5
1,2,4-trimethylbenzene 95-63-6
1,1-dichloroethane 75-34-3
1,1-dichloropropene 563-58-6
1,2-diphenylhydrazine 122-66-7
1,3-dichloropropane 142-28-9
1,3-dichloropropene 542-75-6
2,4,6-trichlorophenol 88-06-2
2,2-dichloropropane 594-20-7
2,4-dichlorophenol 120-83-2
2,4-dinitrophenol 51-28-5
2,4-dinitrotoluene 121-14-2
2,6-dinitrotoluene 606-20-2
2-methyl-Phenol (o-cresol) 95-48-7
Acetochlor 34256-82-1
Alachlor ESA & other acetanilide pesticide degradation products N/A
Aldrin 309-00-2
Aluminum 7429-90-5
Boron 7440-42-8
Bromobenzene 108-86-1
DCPA mono-acid degradate 887-54-7
DCPA di-acid degradate 2136-79-0
DDE 72-55-9
Diazinon 333-41-5
Dieldrin 60-57-1
Disulfoton 298-04-4
Diuron 330-54-1
EPTC (s-ethyl-dipropylthiocarbamate) 759-94-4
Fonofos 944-22-9
Hexachlorobutadiene 87-68-3
p-Isopropyltoluene (p-cymene) 99-87-6
Linuron 330-55-2
Manganese 7439-96-5
Methyl bromide 74-83-9
Methyl-t-butyl ether (MTBE) 1634-04-4
Metolachlor 51218-45-2
Metribuzin 21087-64-9
Molinate 2212-67-1
Naphthalene 91-20-3
Nitrobenzene 98-95-3
Organotins N/A
Perchlorate 14797-73-0
Prometon 1610-18-0
RDX 121-82-4
Sodium 7440-23-5
Sulfate 14808-79-8
Terbacil 5902-51-2
Terbufos 13071-79-9
Triazines & degradation products of triazines including, but not limited to Cyanazine 21725-46-2 and atrazine-desethyl 6190-65-4
Vanadium 7440-62-2


1 Chemical Abstract Service Registry Number (CASRN#) - Chemical abstract service registry numbers are used in reference works, databases, and regulatory compliance documents by many organizations around the world to identify substances with a standardized name.

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