An official website of the United States government.

Contaminant Candidate List (CCL) and Regulatory Determination

Microbial Contaminants - CCL 4

Final CCL 4 Microbial Contaminants

Microbial Contaminant Name
Type
Diseases and Infections
Adenovirus
Virus
Respiratory illness and occasionally gastrointestinal illness.
Caliciviruses
Virus (includes Norovirus)
Mild self-limiting gastrointestinal illness.
Campylobacter jejuni
Bacteria
Mild self-limiting gastrointestinal illness.
Enterovirus
Viruses including polioviruses, coxsackieviruses and echoviruses
Mild respiratory illness.
Escherichia coli (0157)
Bacteria
Gastrointestinal illness and kidney failure.
Helicobacter pylori
Bacteria
Found in the environment capable of colonizing human gut that can cause ulcers and cancer.
Hepatitis A virus
Virus
Liver disease and jaundice.
Legionella pneumophila
Bacteria
Found in the environment including hot water systems causing lung diseases when inhaled.
Mycobacterium avium
Bacteria
Lung infection in those with underlying lung disease, and disseminated infection in the severely immuno compromised.
Naegleria fowleri
Protozoan
Parasite found in shallow, warm surface and ground water causing primary amebic meningoencephalitis.
Salmonella enterica
Bacteria
Mild self-limiting gastrointestinal illness.
Shigella sonnei
Bacteria
Mild self-limiting gastrointestinal illness and bloody diarrhea.