EPA Regulated

ContaminantDescriptionEPA Classification
1,1,1-Trichloroethane1,1,1-Trichloroethane is an industrial cleaning solvent that contaminates drinking water sources due to releases from metal degreasing sites and chemicals factories.Organic Chemicals
1,1,2-Trichloroethane1,1,2-Trichloroethane is used in production of synthetic fibers, plastic wraps and adhesives; it is released as a pollutant from various chemical manufacturing factories.Organic Chemicals
1,1-DichloroethyleneIndustrial chemical pollutant from manufacture of adhesives, synthetic fibers, refrigerants and plastic wraps.Organic Chemicals
1,2,4-Trichlorobenzene1,2,4-Trichlorobenzene is a pollutant from textile finishing factories and industrial chemical manufacturing.Organic Chemicals
1,2-Dibromo-3-chloropropane1,2-Dibromo-3-chloropropane is a persistent pesticide and groundwater contaminant associated with male sterility and severe reproductive toxicity; historically used as a soil fumigant on bananas and pineapples; banned by EPA in early 1980s.Organic Chemicals
1,2-Dichloroethane1,2-Dichloroethane is a chemical used in the production of vinyl chloride; it is released as a pollutant from industrial chemical factories.Organic Chemicals
1,2-Dichloropropane1,2-Dichloropropane is used as a solvent and intermediate in the production of dry cleaning agent perchloroethylene; it is released as a pollutant from chemical factories, landfills, and from agricultural soil due to former use as a fumigant.Organic Chemicals
2,4,5-TP2,4,5-TP (Silvex) is an herbicide banned in 1985; it was formerly used in homes and on recreation areas, industrial sites, lumber yards, vacant lots, lawns and turf, and crops including rice.Organic Chemicals
2,4-D2,4-D is a chlorophenol herbicide used on row crops, lawns and golf courses.Organic Chemicals
AcrylamideAcrylamide (or acrylic amide) is a chemical compound with the chemical formula C3H5NO. Its IUPAC name is prop-2-enamide. It is a white odourless crystalline solid, soluble in water, ethanol, ether, and chloroform. Acrylamide decomposes in the presence of Organic Chemicals
AlachlorAlachlor is a widely-used herbicide applied to corn, soy and sorghum; it is carcinogenic to animals and potentially carcinogenic in people.Organic Chemicals
Alpha particlesAn alpha particle is identical to a helium nucleus having two protons and two neutrons. It is a relatively heavy, high-energy particle, with a positive charge of +2 from its two protons. Alpha particles have a velocity in air of approximately one-twentietRadionuclides
AntimonyAntimony is a metal that enters water from petroleum refinery pollution, fire retardants, ceramics, electronics and solder.Inorganic Chemicals
ArsenicArsenic contaminates drinking water due to mining runoff, erosion of natural deposits, emissions from glass and electronics processing and the use of arsenical compounds as wood preservatives and pesticides.Inorganic Chemicals
AsbestosAsbestos is a mineral fiber introduced into water by the dissolution of asbestos-containing minerals and from decay of asbestos cement in water mains. Inorganic Chemicals
AtrazineAtrazine is an endocrine-disrupting herbicide used on corn, sugarcane and sorghum; it is associated with adverse reproductive effects and toxicity to the immune system.Organic Chemicals
BariumBarium is a mineral that enters drinking water through drilling and mining waste runoff, discharges from chemical industries and erosion of natural deposits.Inorganic Chemicals
BenzeneBenzene is a petroleum chemical that contaminates drinking water due to emissions from petroleum and chemical industries, leaching landfills and gas storage tanks.Organic Chemicals
Benzo(a)pyreneBenzo(a)pyrene is a polycyclic aromatic hydrocarbon that contaminates drinking water from leaching coal tar coatings on water distribution pipes and storage liners; it is also a product of combustion.Organic Chemicals
BerylliumBeryllium is a metal associated with metal refineries and combustion of fossil fuels, especially coal burning; it is released into the environment from electrical, aerospace and defense industries.Inorganic Chemicals
Beta particles and photon emittersBeta particles have an electrical charge of -1. Beta particles have a mass of 549 millionths of one atomic mass unit, or AMU, which is about 1/2000 of the mass of a proton or neutron. The speed of individual beta particles depends on how much energy they Radionuclides
BromateBromate is a carcinogenic disinfection byproduct of ozonation formed when source waters contain high levels of natural bromide; it can also form following water treatment with chlorine dioxide or hypochlorite.Disinfection Byproducts
CadmiumCadmium is a metal used in the steel and plastic industries; it is released from corrosion of galvanized pipes, runoff from metal refineries, waste batteries and paints; contamination from fertilizers; and erosion of natural deposits.Inorganic Chemicals
CarbofuranCarbofuran is a highly toxic insecticide and soil fumigant that had been used on corn, rice and alfalfa; it poses severe risks to children (via diet), agricultural workers and the environment.Organic Chemicals
Carbon tetrachlorideCarbon tetrachloride is an industrial solvent and refrigerant released as a pollutant from various chemical plants and the petroleum refining industry.Organic Chemicals
ChloraminesCompounds formed by the reaction of hypochlorous acid (or aqueous chlorine) with ammonia.Disinfectants
ChlordaneChlordane is a persistent insecticide/termiticide that is likely carcinogenic to humans and has been banned in the U.S. since 1988.Organic Chemicals
ChlorineWater additive used to control microbes Disinfectants
Chlorine dioxideChlorine dioxide is used as drinking water disinfection agent and as a bleaching agent for cellulose, paper pulp, flour and oils; in water, it rapidly decomposes into toxic disinfection byproducts chlorite and chlorate.Disinfectants
ChloriteChlorite is a disinfection byproduct resulting from water treatment with chlorine dioxide, or from the use of chlorine dioxide as a bleaching agent for cellulose, paper pulp, flour and oils.Disinfection Byproducts
ChlorobenzeneChlorobenzene is an aromatic organic compound with the chemical formula C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals.Organic Chemicals
ChromiumChromium is a metal that pollutes drinking water due to discharge from steel and pulp mills and erosion of natural deposits.Inorganic Chemicals
cis-1,2-Dichloroethylenecis-1,2-Dichloroethylene is a pollutant discharged by various industrial chemical factories from the manufacture of plastic wrap, adhesives and synthetic fiber.Organic Chemicals
ColiformsColiform bacteria are a commonly used bacterial indicator of sanitary quality of foods and water. They are defined as rod-shaped Gram-negative non-spore forming bacteria which can ferment lactose with the production of acid and gas when incubated at 35-37Microorganisms
CopperCopper is a naturally occuring metal and drinking water contaminant that enters tap water by corrosion of household plumbing systems and erosion of natural deposits.Inorganic Chemicals
CryptosporidiumCryptosporidium is a single-celled protozoan parasite commonly found in lakes and rivers, especially when the water is contaminated with sewage and animal waste. Microorganisms
CyanideCyanide is a chemical used in mining and steel/metal, plastic, and pesticide manufacturing; it is applied to roads as road salts, and small quantities occur naturally in some plants.Inorganic Chemicals
CystsCysts are single-celled protozoan parasites commonly found in lakes and rivers, especially when the water is contaminated with sewage and animal waste. Common cysts include Cryptosporidium and Gairdia lamblia.Microorganisms
DalaponDalapon is an herbicide used on roads, railway tracks and other rights of way.Organic Chemicals
Di adipateDi(2-Ethylhexyl) adipate is a placticizer and solvent released as a pollutant from industrial chemical factories, sewage treatment facilities and iron foundries.Organic Chemicals
Di phthalateDi(2-ethylhexyl) phthalate is a pollutant from rubber and industrial chemical factories and a leachate from PVC pipes; it is classified by EPA as a probable human carcinogen.Organic Chemicals
DichloromethaneDichloromethane is a widely-used paint remover, solvent and metal degreasing agent; it is discharged into the environment from the manufacture of chemicals, textiles, electronics, metals and plastics, pharmaceuticals and pesticides.Organic Chemicals
DinosebDinoseb is an herbicide historically used on soybeans and vegetables; it is associated with birth defects and reproductive difficulties and has been banned in the U.S. since 1986.Organic Chemicals
DioxinAny of a family of compounds known chemically as dibenzo-p-dioxins. Concern about them arises from their potential toxicity as contaminants in commercial products. Tests on laboratory animals indicate that it is one of the more toxic anthropogenic (man-maOrganic Chemicals
DiquatDiquat is a non-selective herbicide and dessicant used extensively for control of crop and aquatic weeds; it may cause cataracts.Organic Chemicals
EndothallEndothall is an herbicide and defoliant used on a broad range of crops and aquatic plants.Organic Chemicals
EndrinEndrin is a banned organochlorine insecticide that is persistent, bioaccumulative, acutely toxic to vertebrates and associated with massive deaths of fish, birds and other wildlife.Organic Chemicals
EpichlorohydrinEpichlorohydrin (abbreviated ECH) is an organochlorine compound and an epoxide. This is a colorless liquid with a pungent, garlic-like odor, moderately soluble in water, but miscible with most polar organic solvents.[2] Epichlorohydrin is a highly reactivOrganic Chemicals
EthylbenzeneEthylbenzene is a pollutant from petroleum refineries and industrial chemical factories; it is also used to make plastics, and may be present as an impurity in some insecticides.Organic Chemicals
Ethylene dibromideEthylene dibromide is a a pollutant from petroleum refineries that was formerly used as gasoline additive and a pesticide suspended from use by EPA in 1984.Organic Chemicals
FluorideFluoride-containing compounds are used in topical and systemic fluoride therapy for preventing tooth decay. They are used for water fluoridation and in many products associated with oral hygiene.[12] Originally, sodium fluoride was used to fluoridate wateInorganic Chemicals
Giardia lambliaGiardia lamblia is a single-celled protozoan parasite that lives in the intestine of infected humans or animals. It is found on surfaces or in soil, food, or water that has been contaminated with the feces from infected humans or animals. Microorganisms
GlyphosateGlyphosate is one of the most commonly used herbicides in the U.S., and is applied in agriculture, forestry and on lawns and roadsides.Organic Chemicals
Haloacetic acidsHaloacetic acids refers to the sum of the concentrations of five related disinfection byproducts in a water sample: dichloroacetic acid, trichloroacetic acid, monochloroacetic acid, monobromoacetic acid and dibromoacetic acid.Disinfection Byproducts
HeptachlorHeptachlor is a highly toxic and carcinogenic termiticide banned from most applications in the U.S. since 1988.Organic Chemicals
Heptachlor epoxideHeptachlor epoxide is a beakdown product of heptachlor, a highly toxic and carcinogenic termiticide banned from most applications in the U.S. since 1988.Organic Chemicals
Heterotrophic plate countThe number of colonies of heterotrophic bacteria grown on selected solid media at a given temperature and incubation period, usually expressed in number of bacteria per milliliter of sample.Microorganisms
HexachlorobenzeneHexachlorobenzene is a pollutant from metal refineries and agricultural chemical factories.Organic Chemicals
HexachlorocyclopentadieneHexachlorocyclopentadiene is an industrial pollutant discharged from chemical factories.Organic Chemicals
LeadLead is a metal that enters water by corrosion of household plumbing systems, discharge of industrial pollution and erosion of natural deposits.Inorganic Chemicals
LegionellaA genus of bacteria, some species of which have caused a type of pneumonia called Legionnaires Disease.Microorganisms
LindaneLindane is an insecticide still used in shampoo to control lice and scabies; it is a form of hexachlorocyclohexane, a highly toxic pesticide phased out of agricultural use in the U.S.Organic Chemicals
MercuryMercury is a metal from refinery and factory pollution, coal burning, landfill and agricultural runoff and erosion of natural deposits.Inorganic Chemicals
MethoxychlorMethoxychlor is an endocrine-disrupting insecticide similar to DDT; banned in the U.S. in 2002, it was historically used on farm animals and in animal feed, lumber, gardens and certain crops. Organic Chemicals
NitrateNitrate enters drinking water sources from fertilizer runoff, leaching septic tanks, and erosion of natural deposits; it is also emitted by chemical, petrochemical and metal-finishing industries.Inorganic Chemicals
NitriteNitrite is a chemical that enters water from fertilizer runoff, leaching septic tanks, and erosion of natural deposits.Inorganic Chemicals
o-Dichlorobenzeneo-Dichlorobenzene (1,2-Dichlorobenzene) is an intermediate for making herbicides; it is discharged as a pollutant from the manufacture of agricultural chemicals.Organic Chemicals
OxamylOxamyl is a neurotoxic insecticide used on cotton, fruit and vegetable crops (apples, potatoes and tomatoes).Organic Chemicals
p-Dichlorobenzenep-Dichlorobenzene is a carcinogenic pesticide used as a fumigant, deodorant, and in manufacture of other industrial chemicals.Organic Chemicals
PentachlorophenolPentachlorophenol is a carcinogenic pollutant discharged from wood preserving factories.Organic Chemicals
PicloramPicloram is an herbicide that may contaminate drinking water sources due to runoff from applications to pasture, rangeland and rights-of-way.Organic Chemicals
Polychlorinated biphenylsPolychlorinated biphenyls (PCBs) are a group of highly toxic chlorinated industrial chemicals used as dielectrics, coolants and lubricants in electrical equipment; PCBs contaminate water by leaching from landfills or other waste deposits.Organic Chemicals
Radium 226 and Radium 228Radium is a naturally radioactive, silvery-white metal when freshly cut. It blackens on exposure to air. Purified radium and some radium compounds glow in the dark (luminesce). The radiation emitted by radium can also cause certain materials, called "pRadionuclides
SeleniumSelenium is a naturally occurring element that contaminates water due to mining or petrolum refining, fly-ash from coal-burning power plants, and irrigation of arid farmland soils high in selenium.Inorganic Chemicals
SimazineSimazine is a widely used herbicide that has been associated with endocrine disruption and cancer in experimental studies.Organic Chemicals
StyreneStyrene is a pollutant from plastics, rubber and other industrial chemical factories and from landfill leachate.Organic Chemicals
TetrachloroethyleneTetrachloroethylene (perc) is a common soil and groundwater contaminant used in dry cleaning and as a solvent in automotive and metalworking factories and other industries.Organic Chemicals
ThalliumThallium is a highly toxic metal that contaminates the environment due to leaching from ore-processing sites, discharge from electronics, glass, and drug factories and historical use as rodenticideInorganic Chemicals
TolueneToluene is a pollutant from petroleum refineries and a chemical used in plastics manufacturing as well as the pharmaceutical, paint and furniture industries.Organic Chemicals
ToxapheneToxaphene is a highly toxic, persistent and bioaccumulative insecticide anticipated to be carcinogenic to people, and banned from use in the U.S. in 1990.Organic Chemicals
trans-1,2-Dichloroethylenetrans-1,2-Dichloroethylene is a synthetic chemical used as a solvent, refrigerant, and in the production of pharmaceuticals; it is released as pollutant from various industrial chemical factories.Organic Chemicals
TrichloroethyleneTrichloroethylene is used to remove grease from fabricated metal parts and in the production of some textiles; this pollutant comes from metal degreasing sites, metal finishing and rubber processing industries.Organic Chemicals
TrihalomethanesTrihalomethanes constitute the sum of four disinfection byproducts: chloroform, bromodichloromethane, dibromochloromethane, and bromoform.Disinfection Byproducts
TurbidityTurbidity is a measure of the cloudiness of water. It is used to indicate water quality and filtration effectiveness (e.g., whether disease-causing organisms are present). Higher turbidity levels are often associated with higher levels of disease-causing Microorganisms
UraniumNaturally occurring radioactive element whose principal isotopes are Uranium-238 and Uranium-235. Natural uranium is a hard silvery-white shiny metallic ore that contains a minute amount of Uranium-234.Radionuclides
Vinyl chlorideVinyl chloride is a chemical used for production of PVC plastic; it contaminates drinking water due to leaching from PVC pipes and discharges from plastics manufacturing.Organic Chemicals
VirusesDisease-causing organisms that grow only inside living cells. Microorganisms
XylenesXylenes are a group of chemicals produced from petroleum and released as pollutants from chemical, plastics and synthetic fiber industries as well as printing, painting, and laboratory uses.Organic Chemicals