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National Primary Drinking Water Standards
Primary (Health Related) Inorganic Contaminants
Contaminant	MCLG	MCL	WQA Recommended Treatment Methods	Potential Health Effects from Ingestion of Water	Sources of Contaminant in Drinking Water
Antimony	0.006 mg/L	0.006 mg/L	Coagulation/Filtration Submicron Filtration Reverse Osmosis Ultrafiltration Distillation	Increase in blood cholesterol Decrease in blood glucose	Fire retardants Ceramics Electronics Solder Discharge from petroleum refineries
Arsenic (+3)	zero	10 ppb (P)* (Total arsenic) Currently 50 ppb	Chemical Oxidation Reverse Osmosis Distillation Iron Based Media Anion Exchange Activated Alumina	Skin damage Circulatory system problems Increased risk of cancer	Discharge from semiconductor manufacturing Petroleum refining Wood preservatives Animal feed additives Herbicides Erosion of natural deposits
Arsenic (+5)	zero	10 ppb (P)* (Total arsenic) Currently 50 ppb	Coagulation/Filtration Submicron Filtration Anion Exchange Activated Alumina Reverse Osmosis Distillation Electrodialysis Iron Based Media	See Arsenic (+3) above	See Arsenic (+3) above
Arsenic (organic complexes)	zero	10 ppb (P)* (Total arsenic) Currently 50 ppb	Activated Carbon	See Arsenic (+3) above	See Arsenic (+3) above
Asbestos (fibers > 10µm)	7 MFL	7 MFP (million fibers per liter, >10µm)	Coagulation/Filtration Submicron Filtration Reverse Osmosis Ultrafiltration Distillation	Increased risk of developing benign intestinal polyps	Asbestos cement in water systems Natural Deposits
Barium	2.0 mg/L	2.0 mg/L	Cation Exchange Reverse Osmosis Distillation Electrodialysis	Circulatory system effects	Natural deposits Discharge of drilling wastes Discharge from metal refineries
Beryllium	0.004 mg/L	0.004 mg/L	Coagulation/Filtration Submicron Filtration Activated Carbon Activated Alumina Cation Exchange Reverse Osmosis Distillation Electrodialysis Ultrafiltration	Intestinal lesions	Discharge from electrical, aerospace, defense industries Discharge from metal refineries and coal-burning factories
Cadmium	0.005 mg/L	0.005 mg/L	Coagulation/Filtration Submicron Filtration Cation Exchange Reverse Osmosis Distillation Electrodialysis	Kidney effects	Galvanized pipe corrosion Natural deposits Batteries Paints
Chlorine	4 mg/L (P)*	4 mg/L (P)*	Activated Carbon Reverse Osmosis	Cancer	Chemical added to disinfect municipal water
Chromium (+3)	0.1 mg/L	0.1 mg/L (total chromium)	Coagulation/Filtration Cation Exchange Reverse Osmosis Distillation Electrodialysis	Liver disorders Kidney disorders Circulatory disorders	Natural deposits Steel and pulp mills
Chromium (+6)	See Chromium (+3) above	See Chromium (+3) above	Anion Exchange Reverse Osmosis Distillation Electrodialysis	See Chromium (+3) above	See Chromium (+3) above
Chromium (organic complexes)	See Chromium (+3) above	See Chromium (+3) above	Activated Carbon	See Chromium (+3) above	See Chromium (+3) above
Copper	1.3 mg/L	1.3 mg/L (action level)	Cation Exchange (20% - 90%) Reverse Osmosis Distillation Electrodialysis Corrosion control Polyphosphate/Silicate feed	Gastrointestinal irritation	Natural/industrial deposits Wood preservatives Plumbing
Cyanide	0.2 mg/L	0.2 mg/L	Chemical Oxidation Anion Exchange Reverse Osmosis Distillation Electrodialysis	Thyroid damage Nervous system damage	Electroplating Steel Plastics Mining Fertilizer
Fluoride	4.0 mg/L	4.0 mg/L	Activated Alumina Bone Char Reverse Osmosis Distillation Electrodialysis	Skeletal & dental fluorosis	Natural deposits Fertilizer Aluminum industries Water additive
Lead	zero	0.015 mg/L (action level)	Cation Exchange (20% - 90%) Coagulation/Filtration Reverse Osmosis Distillation Electrodialysis	Kidney damage Nervous system damage Impedes mental and physical development	Natural/industrial deposits Plumbing Solder Brass alloy faucets
Mercury (organic complexes)	0.002 mg/L (Total mercury)	0.002 mg/L (Total mercury)	Activated Carbon	Kidney damage	Crop runoff Natural deposits Batteries Electrical switches
Mercury (+2)	See Mercury (organic) above	See Mercury (organic) above	Submicron Filtration/ Activated Carbon Cation Exchange (20% - 90%) Reverse Osmosis Distillation Electrodialysis	See Mercury (organic) above	See Mercury (organic) above
Mercury (HgCl3-)	See Mercury (organic) above	See Mercury (organic) above	Anion Exchange Reverse Osmosis Distillation Electrodialysis	See Mercury (organic) above	See Mercury (organic) above
Nickel	0.1 mg/L	0.1 mg/L	Cation Exchange Reverse Osmosis Distillation Electrodialysis	Heart damage Liver damage	Metal alloys Electroplating Batteries Chemical production
Nitrate (as nitrogen)	10 mg/L	10 mg/L	Anion Exchange Reverse Osmosis (sensitive to pressure) Distillation Electrodialysis	Methemo-globulinemia	Animal waste Fertilizer Natural deposits Septic tanks Sewage
Nitrite (as nitrogen)	1 mg/L	1 mg/L	Chemical Oxidation Anion Exchange Reverse Osmosis Distillation Electrodialysis	Methemo-globulinemia	Same as nitrate; rapidly converted to nitrate.
Selenium (+4)	0.05 mg/L (total selenium)	0.05 mg/L (total selenium)	Coagulation/Filtration Submicron Filtration/ Activated Carbon Anion Exchange Activated Alumina Reverse Osmosis Distillation Electrodialysis	Hair and fingernail loss Circulatory problems	Natural deposits Mining Smelting Coal/Oil combustion
Selenium (+6)	See Selenium (+4) above	see Selenium (+4) above	Anion Exchange Activated Alumina Reverse Osmosis Distillation Electrodialysis	See Selenium (+4) above	See Selenium (+4) above
Sulfate	500 mg/L (proposed standard)	500 mg/L (proposed standard)	Anion Exchange Reverse Osmosis Distillation Electrodialysis	Diarrhea	Natural deposits
Thallium	0.0005 mg/L	0.002 mg/L	Cation Exchange Activated Alumina Distillation	Kidney, liver, brain, intestinal damage	Electronics Drugs Alloys Glass

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