Water: Basic Information about Regulated Drinking Water Contaminants
Drinking WaterDrinking Water ContaminantsBasic Information about Regulated Drinking Water Contaminants and IndicatorsBasic Information about Regulated Drinking Water Contaminants and Indicators
Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. EPA sets standards for approximately 90 contaminants and indicators in drinking water. The presence of indictors at a level outside of specified limits may reflect a problem in the treatment process or in the integrity of the distribution system.
The fact sheets posted on this page update fact sheets published previously, and add new ones. For historical purposes, the original versions are available in PDF format on this page: Drinking Water Contaminants.
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
A
Acrylamide
Alachlor
Alpha Photon Emitters (Radionuclides)
Antimony
Arsenic
Asbestos
Atrazine
B
Barium
Benzene
Benzo(a)pyrene
Beryllium
Beta Photon Emitters (Radionuclides)
Bromate (Disinfection Byproduct)
C
Cadmium
Carbofuran
Carbon Tetrachloride
Chloramine (Disinfectant)
Chlorine(Disinfectant)
Chlorine dioxide (Disinfectant)
Chlorite (Disinfection Byproduts)
Chlordane
Chlorobenzene
Chromium
Copper
Cryptosporidium (Pathogen)
Cyanide
D
2,4-Dichlorophenoxyacetic Acid
Dalapon
1,2-Dibromo-3-chloropropane (DBCP)
o-dichlorobenzene
p-Dichlorobenzene
1,2-Dichloroethane
1,1-Dichloroethylene
cis-1,2-Dichloroethylene
trans-1,2-Dichloroethylene
Dichloromethane
1,2-Dichloropropane
Di(2-ethylhexyl) adipate
Di(2-ethylhexyl) phthalate
Dinoseb
Dioxin (2,3,7,8-TCDD)
Diquat
E
Endothall
Endrin
Epichlorohydrin
Ethylbenzene
Ethylene dibromide
F
Fecal Coliform (and Escherichia coli. E. coli (Indicators)
Fecal indicators (Enterococci or coliphage)(Indicators)
Fluoride
G
Giardia lamblia (Pathogen)
Glyphosate
H
Haloacetic acids (HAA5) (Disinfection Byproducts)
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorocyclopentadiene
I
J
K
L
Lead
Legionella (Pathogen)
Lindane
N
Nickel (remanded 1995)
Nitrate
Nitrite
P
Pentachlorophenol
Picloram
Polychlorinated biphenyls (PCBs)
R
Radium 226 and Radium 228 (Radionuclides)
T
Tetrachloroethylene
Thallium
Toluene
Total Coliforms (including fecal coliform and E. Coli) (Indicators)
Total Trihalomethanes (TTHMs) (Disinfection Byproducts)
Toxaphene
2,4,5-TP Silvex
1,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
Turbitity (Indicator)
V
Vinyl Chloride
Viruses (enteric)
Y
Z