See an updated list of Drinking Water Contaminants & their Maximum Contaminant Level at the U.S. Environmental Protection Agency.
EPA Drinking Water maximum contaminant level, its health effects and methods to improve the quality of the water
- 1,1,1-Trichloroethane (Organic Chemical)
- MCL: 0.2 milligrams per litre
- Health Effect: Causes narcosis & probably cancer
- Treatment: Granular activated carbon filter
- 1,1-Dichloroethylene (Organic Chemical)
- MCL: 0.007 milligrams per litre
- Health Effect: Affects kidneys & liver, can cause cancer
- Treatment: Granular activated carbon
- 1,2-Dichloropropane (Organic Chemical)
- MCL: 0.005 milligrams per litre
- Health Effects: Affects lungs, liver & kidneys
- Treatment: Granular activated carbon
- 1.2-Dicloroethane (Organic Chemical)
- MCL: 0.005 milligrams per litre
- Health Effects: Damages kidneys, liver & can cause nausea
- Treatment: Granular activated carbon
- 2,4,5-TP Silvex (Herbicide)
- MCL: 0.05 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, can cause leukemia or cancer
- Treatment: Granular activated carbon
- 2,4-D (Herbicide)
- MCL: 0.07 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, can cause leukemia or cancer
- Treatment: Granular activated carbon
- Alachlor (Herbicide)
- MCL: 0.002 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, can cause leukemia or cancer
- Treatment: Granular activated carbon
- Aldcarb (Pesticide)
- MCL: 0.003 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver and kidneys, can cause leukemia or cancer
- Treatment: Granular activated carbon
- Aldicarb Sulphone (Pesticide)
- MCL: 0.002 milligrams per litre
- Health Effects: Affects nervous, respiratory system, liver & kidneys, can cause leukemia or cancer
- Treatment: Granular activated carbon
- Aldicarb Sulphoxide (Pesticide)
- MCL: 0.004 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Alpha Emitters (Radionuclide)
- MCL: 15 pci/L Curies per litre
- Health Effects: Probable cause of cancer, affects skeletal tissue, & bone sarcomas
- Treatment: RO, ion exchange, lime softening at a high PH
- Aluminium (Contaminant)
- MCL: 0.05 to 0.2 milligrams per litre
- Health Effects: Aesthetic, discolouration of water
- Treatment: Ion exchange, RO, distillation
- Aresenic (Inorganic Chemical)
- MCL: 0.05 milligrams per litre
- Health Effects: Malignant tumors of skin & lungs, affects nervous system
- Treatment: Activated alumina, ion exchange, lime softening, reverse osmosis, distillation
- Asbestos (Inorganic Chemical)
- MCL: 7 MFL million fibres per litre
- Health Effects: Probable cause of cancer
- Treatment: Filtration, reverse osmosis, distillation
- Atrazine (Herbicide)
- MCL: 0.003 milligrams per litre
- Health Effects: Affects nervous and respiratory system, liver and kidney, probable cause of cancer
- Treatment: Activated granular carbon
- Barium (Inorganic Chemical)
- MCL: 2.0 milligrams per litre
- Health effects: Affects nervous & circulatory systems
- Treatment: Ion exchange, lime softening, reverse osmosis, distillation
- Benzene (Inorganic Chemical)
- MCL: 0.005 milligrams per litre
- Health Effects: Leukemia, anemia & possibly cancer
- Treatment: Granular activated carbon
- Beta Particle Emitters (Radionuclides)
- Max Level: 4 milligram per year
- Health Effects: Probable cause of cancer, affects skeletal tissue, bone sacromas, head sacromas
- Treatment: Reverse osmosis, ion exchange, lime softening at high pH
- Cadnium (Inorganic Chemical)
- MCL: 0.005 milligrams per litre
- Health Effects: Kidney disorders, bronchitis, anemia
- Treatment: Ion exchange, reverse osmosis, lime softening, distillation, corrosion control
- Carbofuran (Pesticide)
- MCL: 0.04 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Carbon Tetrachloride (Organic Chemical)
- MCL: 0.005 milligrams per litre
- Health Effects: Affects nervous system, liver and digestive system, causes cancer
- Treatment: Granular activated carbon
- Chlordane (Pesticide)
- MCL: 0.002 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Chloride (Contaminant)
- MCL: 250 milligrams per litre
- Health Effects: Taste, smell, corrosion of pipes
- Treatment: Ion exchange, RO, distillation
- Chromium (Inorganic Chemical)
- MCL: 0.1 milligrams per litre
- Health Effects: Liver and kidney disorders, affects skin and digestive system
- Treatment: Ion exchange, lime softening, reverse osmosis, distillation
- Colour (Contaminant)
- MCL: 15 TCU total colour units
- Health Effects: Aesthetic, staining
- Treatment: Sediment filter with granular activated carbon filtration
- Copper (Inorganic Chemical)
- MCL: 1.3 milligrams per litre
- Health Effects: Stomach and intestinal distress
- Treatment: Ion exchange, RO, distillation
- Dibromochloropropane (Organic Chemical)
- MCL: 0.0002 milligrams per litre
- Health Effects: Probable cause of cancer
- Treatment: Granular activated carbon
- Endrin (Pesticide)
- MCL: 0.002 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Ethylene Dibromide (Organic Chemical)
- MCL: 0.00005 milligrams per litre
- Health Effects: Probable cause of cancer
- Treatment: Granular activated carbon
- Ethylbenzene (Organic Chemical)
- MCL: 0.7 milligrams per litre
- Health Effects: Affects nervous system, liver and kidneys
- Treatment: Granular activated charcoal
- Fluoride (Inorganic Chemical)
- MCL: 4.0 milligrams per litre
- Health Effects: Brown discolouration of teeth
- Treatment: Ion exchange, reverse osmosis, distillation, activated alumina
- Foaming Agents (Contaminant)
- MCL: 0.5 milligrams per litre
- Health Effect: Aesthetic
- Treatment: Carbon filtration, distillation
- Giardia Lamblia (Microbiological)
- MCL: Zero colonies
- Health Effects: Stomach cramps, intestinal distress (Giardiasis)
- Treatment: Filtration, chlorination, UV radiation, distillation
- Heptachlor (Pesticide)
- MCL: 0.0004 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Heptachlor Epoxide (Pesticide)
- MCL: 0.0002 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Iron (Contaminant)
- MCL: 0.3 milligrams per litre
- Health Effects: Taste, staining, scaling, discolouration of water
- Treatment: Ion exchange, chlorination, filtration, distillation
- Lead (Inorganic Chemical)
- MCL: 0.015 milligrams per litre
- Health Effects: Affects nervous & reproductive system and kidneys, causes hypertension
- Treatment: Ion exchange, reverse osmosis, distillation, activated carbon granular filter (preferably carbon block filter)
- Legionella (Microbiological)
- MCL: Zero colonies
- Health Effects: Causes Legionnaires disease, Pontiac fever
- Treatment: Filtration, chlorination, UV radiation
- Lindane (Pesticide)
- MCL: 0.0002 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Manganese (Contaminant)
- MCL: 0.05 milligrams per litre
- Health Effects: Taste, staining, scaling, discolouration of water
- Treatment: Ion exchange, chlorination, filtration, distillation
- Mercury (Inorganic Chemical)
- MCL: 0.002 milligrams per litre
- Health Effects: Affects nervous system, kidneys
- Treatment: Granular activated carbon, lime softening, reverse osmosis, distillation
- Methoxychlor (Pesticide)
- MCL: 0.04 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Monochlorovenzene (Organic Chemical)
- MCL: 0.1 milligrams per litre
- Health Effects: Affects nervous system, kidneys and liver
- Treatment: Granular activated carbon
- Nitrate (Inorganic Chemical)
- MCL: 10 milligrams per litre
- Health Effect: Methmoglobinemia
- Treatment: Ion exchange, RO, distillation
- Nitrite (Inorganic Chemical)
- MCL: 1.0 milligram per litre
- Health Effect: Methmoglobinemia
- Treatment: Ion exchange, RO, distillation
- Odour (Contaminant)
- MCL: 3 ton total odour units
- Health Effects: Aesthetic
- Treatment: Activated granular carbon
- Pentachlorophenol (Herbicide)
- MCL: 0.001 milligrams per litre
- Health Effects: Affects nervous system, respiratory system, liver & kidneys, causes leukemia or cancer
- Treatment: Granular activated carbon
- Radium 226 & 228 (Radionuclides)
- MCL: 5 pci/L pico Curies per litre
- Health Effects: Probable cause of cancer, affects skeletal tissue, & bone sarcomas
- Treatment: RO, ion exchange, lime softening at a high pH
- Selenium (Inorganic Chemical)
- MCL: 0.05 milligrams per litre
- Health Effects: Affects nervous system, causes irritation to the mucous membrane
- Treatment: Distillation, lime softening, reverse osmosis, activated alumina
- Silver (Contaminant)
- MCL: 0.1 milligrams per litre
- Health Effects: Discolouration of skin
- Treatment: Ion exchange, RO, distillation
- Sodium (Inorganic Chemical)
- MCL: none (20mg/L makes water too salty)
- Health Effects: Possible increased blood pressure in susceptible individuals
- Treatment: Distillation, RO, ion exchange
- Styrene (Organic Chemical)
- MCL: 0.1 milligrams per litre
- Health Effects: Affects nervous system, liver and kidney
- Treatment: Granular activated carbon
- Sulfate (Contaminant)
- MCL: 250 milligrams per litre
- Health Effect: Taste, laxative effects
- Treatment: Ion exchange, RO, distillation
- Tetrachloroethylene (Organic Chemical)
- MCL: 0.005 milligrams per litre
- Health Effects: Affects nervous system, probable cause of cancer
- Treatment: Granular activated carbon
- Trihalomethanes (Organic Chemical)
- MCL: 0.1 milligrams per litre
- Health Effects: Affects nervous system, probable cause of cancer
- Treatment: Granular activated carbon
- Turbidity (Contaminant)
- MCL: 0.5 - 1.0 NTU Turbidity Units
- Health Effects: Interferes with disinfection
- Treatment: Filtration, granular activated carbon, distillation, reverse osmosis
- Vinyl Chloride (Organic Chemical)
- MCL: 0.002 milligrams per litre
- Health Effects: Affects nervous system, probable cause of cancer
- Treatment: Granular activated carbon
- Xylenes - total (Organic chemical)
- MCL: 10 milligrams per litre
- Health Effects: Affects nervous system, kidneys, lungs, liver and mucous membranes
- Treatment: Granular activated carbon
- Zinc (Contaminant)
- MCL: 5.0 milligrams per litre
- Health Effects: Taste
- Treatment: Ion exchange, reverse osmosis, distillation
Suggested treatments given above are only some of the methods. Sometimes one method by itself is adequate but at times a combination of methods is needed. Under some treatments a choice of methods is given. Consult your local water treatment company for the best recommendation of treatment method.
- MCL
- Maximum Contaminant Level