National Primary Drinking Water Standards Primary (Health Related) Inorganic Contaminants
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See Also: Water Treatment Terms & Definitions
| Contaminants | 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 |
-Cancer | -Fire retardants -Ceramics -Electronics -Fireworks -Solder |
| Arsenic (+3) | 0.05 mg/L | 0.05 mg/L (Interim Standard) | -Chemical Oxidation/Disinfection -Reverse Osmosis -Distillation |
-Skin Damage -Nervous system toxicity |
-Natural deposits -Smelters -Glass -Electronic wastes -Orchards |
| Arsenic (+5) | -Coagulation/Fiiltration -Submicron Filtration -Anion Exchange -Activated Alumina -Reverse Osmosis -Distillation -Electrodialysis |
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| Arsenic (organic complexed) | -Activated Carbon | ||||
| Asbestos (fibers > 10 µm) | 7 MFL | 7 MFP (million fibers per liter, >10 µm) | -Coagulation/Filtration -Submicron Filtration -Reverse Osmosis -Ultrafiltration -Distillation |
-Cancer -Nervous system toxicity |
-Natural deposits -Asbestos cement in water systems |
| Barium | 2.0 mg/L | 2.0 mg/L | -Cation Exchange -Reverse Osmosis -Distillation -Electrodialysis |
-Circulatory system effects -Nervous system toxicity |
-Natural deposits -Pigments -Epoxy sealants -Spent coal |
| Beryllium | 0.004 mg/L | 0.004 mg/L | -Coagulation/Filtration -Submicron Filtration -Activated Carbon -Activated Alumina -Cation Exchange -Reverse Osmosis -Distillation -Electrodialysis |
-Bone damage -Lung Damage |
-Electrical aerospace, defense industries |
| Cadmium | 0.005 mg/L | 0.005 mg/L | -Coagulation/Filtration -Submicron Filtration -Cation Exchange -Distillation |
-Kidney Effects | -Galvanized pipe corrosion -Natural deposits -Batteries -Paints |
| Choromium (+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 -Mining -Electroplating -Pigments |
| Chromium (+6) | Same As above | -Anion Exchange -Reverse Osmosis -Distillation -Electrodialysis |
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| Chromium (organic complexes) | Same As above | -Activated Carbon | |||
| Copper | 1.3 mg/L | 1.3 mg/L (action level) | -Cation Exchange (20%-90%) -Reverse Osmosis -Distillation -Electrodialysis |
-Gastrointestinal irritation | -Natural/industrial deposits -Wood preservatives -Plumbing |
| Cyanide | 0.2 mg/L | 0.2 mg/L | -Chemical Oxidation/Disinfection -Anion Exchange (20%-90%) -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 florosis | -Natural deposits -Fertilizer -Aluminum industries -Water additive |
| Lead | zero | 0.015 mg/L (action level) | -Cation Exchange(20%-90%) -Coagulation/Filtration -Submicron Filtration/Activated Carbon -Reverse Osmosis -Distillation -Electrodialysis |
-Kidney damage -Nervous system damage |
-Natural/industrial deposits -Plumbing -Solder -Brass alloy faucets |
| Mercury (+2) | 0.002 mg/L | 0.002 mg/L (total mercury) | -Cation Exchange(20%-90%) -Coagulation/Filtration -Submicron Filtration/Activated Carbon -Reverse Osmosis -Distillation -Electrodialysis |
-Kidney disorders -Nervous system damage |
-Crop runoff -Natural deposits -Batteries -Electrical switches |
| Mercury (HgCl3) | -Anion Exchange(20%-90%) -Reverse Osmosis -Distillation -Electrodialysis |
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| Mercury (organic complexes) | -Activated Carbon | ||||
| Nickel | 0.1 mg/L | 0.1 mg/L | -Cation Exchange(20%-90%) -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 |
-Methemolglobulinemia | -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 |
-Methemolglobulinemia | Same as Nitrate;rapidly converted to Nitrate |
| Selenium (+4) | 0.05 mg/L | 0.05 mg/L (total selenium) | -Coagulation/Filtration -Submicron Filtration/Activated Carbon -Anion Exchange -Activated Alumina -Reverse Osmosis -Distillation -Electrodialysis |
-Liver damage | -Natural deposits -Mining -Smelting -Coal/Oil combustion |
| Selenium (+6) | -Anion Exchange -Activated Alumina -Reverse Osmosis -Distillation -Electrodialysis |
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| Sulfate | 500 mg/L (proposed standard) | 500 mg/L (proposed standard) | -Anion Exchange -Activated Alumina -Reverse Osmosis -Distillation -Electrodialysis |
-Diarrhea | -Natural deposits |
| Thallium | 0.0005 mg/L (proposed standard) | 0.002 mg/L (proposed standard) | -Cation Exchange -Activated Alumina -Distillation |
-Kidney, liver, brain, intestinal damage | -Electronics -Drugs -Alloys -Glass |
National Primary Drinking Water Standards Primary (Health Related) Organic Contaminants
| Contaminants | MCLG, mg/L | MCL, mg/L | Treatment Methods |
|---|---|---|---|
| Acrylamide | zero | 0.0005 (action level) | Control of water treatment chemicals and surfaces in contact with water |
| Adipates (diethylhexyl) | 0.4 | 0.4 | Activated Carbon Aeration |
| Alachlor | zero | 0.002 | Activated Carbon |
| Aldicarb | 0.007(P)* | 0.007(P)* | Activated Carbon |
| Aldicarb sulfone | 0.007 (P)* | 0.007 (P)* | Activated Carbon |
| Aldicarb sulfoxide | 0.007(P)* | 0.007(P)* | Activated Carbon |
| Altrazine | 0.003 | 0.003 | Activated Carbon |
| Benz(a)anthracene (PAH) | zero (P)* | 0.0001 (P)* | Activated Carbon |
| Benzene | zero | 0.005 | Activated Carbon Aeration |
| Benzo(a)pyrene (PAH) | zero | 0.0002 | Activated Carbon |
| Benzo(b)fluroanthene | zero (P)* | 0.0002 (P)* | Activated Carbon |
| Benzo(k)fluoranthene (PAH) | zero (P)* | 0.0002 (P)* | Activated Carbon |
| Butyl benzyl phthalate (PAE) | zero (P)* | 0.1 (P)* | Activated Carbon |
| Carbofuran | 0.04 | 0.04 | Activated Carbon |
| Carbon tetrachloride | zero | 0.005 | Activated Carbon Aeration |
| Chlordane | zero | 0.002 | Activated Carbon |
| Chrysene (PAH) | zero (P)* | 0.0002 (P)* | Activated Carbon |
| 2,4-D | 0.07 | 0.07 | Activated Carbon |
| Dalapon | 0.2 | 0.2 | Activated Carbon |
| Di[2-ethylhexyl]adipate | 0.4 | 0.4 | Activated Carbon |
| Dibenza(a,h)anthracene (PAH) | zero (P)* | 0.0003 (P)* | Activated Carbon |
| Dibromochloropropane (DBCP) | zero | 0.0002 | Activated Carbon Aeration |
| Dichlorobenzene (ortho-) | 0.6 | 0.6 | Activated Carbon Aeration |
| Dichlorobenzene (meta-) | 0.6 | 0.6 | Activated Carbon Aeration |
| Dichlorobenzene (para-) | 0.075 | 0.075 | Activated Carbon Aeration |
| Dichloroethane (1,2-) | zero | 0.005 | Activated Carbon Aeration |
| Dichloroethylene (1,1-) | 0.007 | 0.007 | Activated Carbon Aeration |
| Dichloroethylene (cis-1,2-) | 0.07 | 0.07 | Activated Carbon Aeration |
| Dichloroethylene (trans-1,2-) | 0.1 | 0.1 | Activated Carbon Aeration |
| Dichloromethane (methylene chloride) | zero | 0.005 | Aeration |
| Dichloropropane (1,2-) | zero | 0.005 | Activated Carbon Aeration |
| Diethylhexyl phthalate (PAE) | zero | 0.006 | Activated Carbon |
| Dinoseb | zero | 0.006 | Activated Carbon |
| Diquat | 0.02 | 0.02 | Activated Carbon |
| Endothall | 0.1 | 0.1 | Activated Carbon |
| Endrin | 0.002 | 0.002 | Activated Carbon |
| Epichlorohydrin | zero | 0.002 (action level) | Control of water treatment chemicals and surfaces in contact with water |
| Ethylbenzene | 0.7 | 0.7 | Activated Carbon Aeration |
| Ethylene Dibromide (EDB) | zero | 0.00005 | Activated Carbon Aeration |
| Glyphosphate | 0.7 | 0.7 | Activated Carbon |
| Heptachlor | zero | 0.0004 | Activated Carbon |
| Heptachlor epoxide | zero | 0.0002 | Activated Carbon |
| Hexachlorocyclopentadiene | 0.05 | 0.05 | Activated Carbon Aeration |
| Indenol (1,2,3-c,d)pyrene (PAH) | zero (P)* | 0.0004 (P)* | Activated Carbon |
| Lindane | 0.0002 | 0.0002 | Activated Carbon |
| Methoxychlor | 0.04 | 0.04 | Activated Carbon |
| Monochlorobenzene | 0.1 | 0.1 | Activated Carbon Aeration |
| Oxamyl (vydate) | 0.2 | 0.2 | Activated Carbon |
| Pentachlorophenol | zero | 0.001 | Activated Carbon |
| Picloram | 0.5 | 0.5 | Activated Carbon |
| Picloram | 0.5 | 0.5 | Activated Carbon |
| Polychlorinated byphenyls (PCBs) | zero | 0.0005 | Activated Carbon |
| Simarzine | 0.004 | 0.004 | Activated Carbon |
| Styrene | 0.1 | 0.1 | Activated Carbon Aeration |
| 2,3,7,8-TCDD (dioxin) | zero | 3X10-8 | Activated Carbon |
| Tetrachloroethylene | zero | 0.005 | Activated Carbon Aeration |
| Toluene | 1. | 1. | Activated Carbon Aeration |
| Toxaphene | zero | 0.003 | Activated Carbon |
| 2,4,5-TP (silvex) | 0.05 | 0.05 | Activated Carbon |
| Trichlorobenzene (1,2,4) | 0.07 | 0.07 | Activated Carbon Aeration |
| Trichloroethane (1,1,1-) | 0.2 | 0.2 | Activated Carbon Aeration |
| Trichloroethane (1,1,2-) | 0.003 | 0.005 | Activated Carbon Aeration |
| Trichloroethylene | zero | 0.005 | Activated Carbon Aeration |
Trihalomethanes (THMs)
|
zero | 0.100 | Activated Carbon Aeration Ultrafiltration (20%-90%) Reverse Osmosis (20%-90%) |
| Vinyl chloride | zero | 0.002 | Aeration |
| Xylenes (total) | 10. | 10. | Activated Carbon Aeration |
| (P)* = Proposed Standard MCLG = Maximum Contaminant Level Goal established at the level at which no known or anticipated adverse effects on the health of persons occur and which allows an adequate margin of safety; expressed in milligrams per liter unless otherwise specified. MCL = Maximum Contaminant Level established as close to the MCLG as feasible taking into consideration costs and treatment techniques applicable at public water systems; expressed in milligrams per liter unless otherwise specified. |
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National Secondary Drinking Water Regulations
Recognized Treatment Techniques for meeting the National Secondary Drinking Water Regulations with the Application of Point-Of-Use Systems
"The National Secondary Drinking Water regulations control contaminants in drinking water that primarily affect the aesthetic qualities relating to the public acceptance of drinking water. The regulations are not federally enforceable but are intended as guidelines for the states" (40 CFR Section 143.3)
For simplicity, WQA uses the term Point-Of-Use (POU) when referring to both treatment at the tap and for whole house treatment.
Except for instances of contamination through inhalation or dermal adsorption, the WQA notes that in-home treatment of drinking and cooking water only is often the most economical and preferred method of choice for reducing these drinking water aesthetic contaminants. Of course, the particular contaminant found in the water will determine the appropriate treatment technique.
The recognized treatment methods listed here reflect the fact that point-of-use systems on the market today may differ widely in their effectiveness to treat any specific contaminant. Anyone contemplating use of such point-of-use equipment for a specific application or purpose should make their selection only after careful investigation of the performance capabilities. As part of the installation procedure, the performance of the system should be verified through an appropriate water analysis. In addition, the product water should be monitored periodically to verify performance.
It is the general consensus of the manufacturers and sellers of the point-of-use systems employing the listed techniques that, if these systems are defect free, properly applied and installed, and maintained strictly according to the manufacturers' installation and maintenance instructions, they may be considered for use in meeting the requirements of the National Secondary Drinking Water Regulations (SDWR).
| Contaminant | SMCL, mg/L | Treatment Methods | ||
|---|---|---|---|---|
| Aluminum (AL +3 ) | 0.05 to 0.2 depending on case-by-case circumstances | Cation Exchange Reverse Osmosis Distillation Electrodialysis |
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| Chloride (C1 -1 ) | 250 | Reverse Osmosis Distillation Anion Exchange Electrodialysis |
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| Color | 15 color units |
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| Copper (Cu +2 ) | 1.0 | Reverse Osmosis Distillation Cation Exchange (20%-90%) Electrodialysis |
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| Corrosivity | Non-corrosive | Calcite or Calcite/Magnesium Oxide (Magnesia) (5 to 1) Filter to raise pH Soda Ash Chemical Feed Polyphosphate Feed Sodium Silicate Feed Reduce TDS via Reverse Osmosis (partial, split stream treatment) Coatings Insulating Unions |
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| Fluoride (Fl -1 ) | 2.0 | Activated Alumina Bone Char Reverse Osmosis Distillation Electrodialysis |
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| Foaming agents (MBAS) (methylene blue active substances) |
0.5 |
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| Iron (Fe +2) (ferric iron) |
0.3 |
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| Iron (Fe +3 ) | 0.05 | Filtration | ||
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*Ferrous Iron (clear water iron) is readily converted to ferric iron (red water iron) in the presence of any air or oxidizing material; precipitating ferric iron must be prevented to avoid fouling and interference with effective reverse osmosis membrane rejection. |
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| Manganese (Mn +2) (ferric iron) |
0.5 | Filtration(oxidizing filters) Cation Exchange Reverse Osmosis* Distillation Pressure Areation/Filtration Chlorination - Precipitation/Filtration Electrodialysis |
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| Manganese (Mn +4 ) | Filtration | |||
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*manganese must be maintained in the soluble manganous (Mn +2) to avoid fouling and interference with effective reverse osmosis membrane rejection. |
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| Odor | 3 threshold odor number | Activated Carbon Aeration Oxidation |
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Note: Chlorine and hydrogen sulfide are examples of odors that may be reduced by the treatment methods suggested. |
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| pH | 6.5-8.5 | pH may be increased by alkalies and may be decreased by acids Ion Exchange Neutralizing Filter (Calcite, Magnesia) |
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| Silver (Ag +1) | 0.1 | Coagulation/Filtration Submicron Filtration/Activated Carbon Ion Exchange (Anion or Cation depending on complexed Ion Species) |
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| Sulfate (SO 4 -2) | 250 | Reverse Osmosis Distillation Anion Exchange Electrodialysis |
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| Total dissolved solids (TDS) | 500 | Reverse Osmosis Distillation Deionzation by Ion Exchange (Cation/Anion in two bed or mixed bed) Electrodialysis |
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| Zinc (Zn +2) | 5 | Reverse Osmosis Distillation Cation Exchange Electrodialysis |
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