Definitions
TT - Treatment Techniques are required to prevent contamination
from microorganisms
MCL - Maximum Contaminant Level
MCLG - Maximum Contaminant Level Goal
| Contaminants | MCLG (mg/L) 1, 4 | MCL or TT (mg/L) 2,3,4 | Potential Health Effects from Ingestion of Water | Sources of Contaminant in Drinking Water |
| Inorganic Chemicals | ||||
| Antimony | 0.006 | 0.006 | Increase in blood cholesterol; decrease in blood glucose | Discharge from petroleum refineries; fire retardants; ceramics; electronics; solder |
| Arsenic | none, (5) | 0.05 | 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 |
| Asbestos (fiber >10 micrometers) | 7 million fibers per Liter | 7 MFL | Increased risk of developing benign intestinal polyps | Decay of asbestos cement in water mains; erosion of natural deposits |
| Barium | 2 | 2 | Increase in blood pressure | Discharge of drilling wastes; discharge from metal refineries; erosion of natural deposits |
| Beryllium | 0.004 | 0.004 | Intestinal lesions | Discharge from metal refineries and coal-burning factories; discharge from electrical, aerospace, and defense industries |
| Cadmium | 0.005 | 0.005 | Kidney damage | Corrosion of galvanized pipes; erosion of natural deposits; discharge from metal refineries; runoff from waste batteries and paints |
| Chromium (total) | 0.1 | 0.1 | Some people who use water containing chromium well in excess of the MCL over many years could experience allergic dermatitis | Discharge from steel and pulp mills; erosion of natural deposits |
| Copper | 1.3 | Action Level=1.3; TT (6) | Short term exposure: Gastrointestinal distress. Long term exposure: Liver or kidney damage. Those with Wilson's Disease should consult their personal doctor if their water systems exceed the copper action level. | Corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives |
| Cyanide (as free cyanide) | 0.2 | 0.2 | Nerve damage or thyroid problems | Discharge from steel/metal factories; discharge from plastic and fertilizer factories |
| Fluoride | 4 | 4 | Bone disease (pain and tenderness of the bones); Children may get mottled teeth. | Water additive which promotes strong teeth; erosion of natural deposits; discharge from fertilizer and aluminum factories |
| Lead | zero | Action Level=0.015; TT (6) | Infants and children: Delays in physical or mental development. Adults: Kidney problems; high blood pressure | Corrosion of household plumbing systems; erosion of natural deposits |
| Inorganic Mercury | 0.002 | 0.002 | Kidney damage | Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and cropland |
| Nitrate (measured as Nitrogen) | 10 | 10 | "Blue baby syndrome" in infants under six months - life threatening without immediate medical attention. | Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits |
| Nitrite (measured as Nitrogen) | 1 | 1 | "Blue baby syndrome" in infants under six months - life threatening without immediate medical attention. Symptoms: Infant looks blue and has shortness of breath. | Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits |
| Selenium | 0.05 | 0.05 | Hair or fingernail loss; numbness in fingers or toes; circulatory problems | Discharge from petroleum refineries; erosion of natural deposits; discharge from mines |
| Thallium | 0.0005 | 0.002 | Hair loss; changes in blood; kidney, intestine, or liver problems | Leaching from ore-processing sites; discharge from electronics, glass, and pharmaceutical companies |
| Organic Chemicals | ||||
| Acrylamide | zero | TT | Nervous system or blood problems; increased risk of cancer | Added to water during sewage/wastewater treatment |
| Alachlor | zero | 0.002 | Eye, liver, kidney or spleen problems; anemia; increased risk of cancer | Runoff from herbicide used on row crops |
| Atrazine | 0.003 | 0.003 | Cardiovascular system problems; reproductive difficulties | Runoff from herbicide used on row crops |
| Benzene | zero | 0.005 | Anemia; decrease in blood platelets; increased risk of cancer | Discharge from factories; leaching from gas storage tanks and landfills |
| Benzo(a)pyrene | zero | 0.0002 | Reproductive difficulties; increased risk of cancer | Leaching from linings of water storage tanks and distribution lines |
| Carbofuran | 0.04 | 0.04 | Problems with blood or nervous system; reproductive difficulties. | Leaching of soil fumigant used on rice and alfalfa |
| Carbon tetrachloride | zero | 0.005 | Liver problems; increased risk of cancer | Discharge from chemical plants and other industrial activities |
| Chlordane | zero | 0.002 | Liver or nervous system problems; increased risk of cancer | Residue of banned termiticide |
| Chlorobenzene | 0.1 | 0.1 | Liver or kidney problems | Discharger from chemical and agricultural chemical factories |
| 2,4-D | 0.07 | 0.07 | Kidney, liver, or adrenal gland problems | Runoff from herbicide used on row crops |
| Dalapon | 0.2 | 0.2 | Minor kidney changes | Runoff from herbicide used on rights of way |
| 1,2-Dibromo-3-chloropropane (DBCP) | zero | 0.0002 | Reproductive difficulties; increased risk of cancer | Runoff/leaching from soil fumigant used on soybeans, cotton, pineapples, and orchards |
| o-Dichlorobenzene | 0.6 | 0.6 | Liver, kidney, or circulatory system problems | Discharge from industrial chemical factories |
| p-Dichlorobenzene | 0.075 | 0.075 | Anemia; liver, kidney or spleen damage; changes in blood | Discharge from industrial chemical factories |
| 1,2-Dichloroethane | zero | 0.005 | Increased risk of cancer | Discharge from industrial chemical factories |
| 1-1-Dichloroethylene | 0.007 | 0.007 | Liver problems | Discharge from industrial chemical factories |
| cis-1, 2-Dichloroethylene | 0.07 | 0.07 | Liver problems | Discharge from industrial chemical factories |
| trans-1,2-Dichloroethylene | 0.1 | 0.1 | Liver problems | Discharge from industrial chemical factories |
| Dichloromethane | zero | 0.005 | Liver problems; increased risk of cancer | Discharge from pharmaceutical and chemical factories |
| 1-2-Dichloropropane | zero | 0.005 | Increased risk of cancer | Discharge from industrial chemical factories |
| Di(2-ethylhexyl)adipate | 0.4 | 0.4 | General toxic effects or reproductive difficulties | Leaching from PVC plumbing systems; discharge from chemical factories |
| Di(2-ethylhexyl)phthalate | zero | 0.006 | Reproductive difficulties; liver problems; increased risk of cancer | Discharge from rubber and chemical factories |
| Dinoseb | 0.007 | 0.007 | Reproductive difficulties | Runoff from herbicide used on soybeans and vegetables |
| Dioxin (2,3,7,8-TCDD) | zero | 0.00000003 | Reproductive difficulties; increased risk of cancer | Emissions from waste incineration and other combustion; discharge from chemical factories |
| Diquat | 0.02 | 0.02 | Cataracts | Runoff from herbicide use |
| Endothall | 0.1 | 0.1 | Stomach and intestinal problems | Runoff from herbicide use |
| Endrin | 0.002 | 0.002 | Nervous system effects | Residue of banned insecticide |
| Epichlorohydrin | zero | TT | Stomach problems; reproductive difficulties; increased risk of cancer | Discharge from industrial chemical factories; added to water during treatment process |
| Ethylbenzene | 0.7 | 0.7 | Liver or kidney problems | Discharge from petroleum refineries |
| Ethelyne dibromide | zero | 0.00005 | Stomach problems; reproductive difficulties; increased risk of cancer | Discharge from petroleum refineries |
| Glyphosate | 0.7 | 0.7 | Kidney problems; reproductive difficulties | Runoff from herbicide use |
| Heptachlor | zero | 0.0004 | Liver damage; increased risk of cancer | Residue of banned termiticide |
| Heptachlor epoxide | zero | 0.0002 | Liver damage; increased risk of cancer | Breakdown of hepatachlor |
| Hexachlorobenzene | zero | 0.001 | Liver or kidney problems; reproductive difficulties; increased risk of cancer | Discharge from metal refineries and agricultural chemical factories |
| Hexachlorocyclopentadiene | 0.05 | 0.05 | Kidney or stomach problems | Discharge from chemical factories |
| Lindane | 0.0002 | 0.0002 | Liver or kidney problems | Runoff/leaching from insecticide used on catttle, lumber, gardens |
| Methoxychlor | 0.04 | 0.04 | Reproductive difficulties | Runoff/leaching from insecticide used on fruits, vegetables, alfalfa, livestock |
| Oxamyl (Vydate) | 0.2 | 0.2 | Slight nervous system effects | Runoff/leaching from insecticide used on apples, potatoes, and tomatoes |
| Polychlorinated biphenyls (PCBs) | zero | 0.0005 | Skin changes; thymus gland problems; immune difficiencies; reproductive or nervous system difficulties; increased risk of cancer | Runoff from landfils; discharge of waste chemicals |
| Pentachlorophenol | zero | 0.001 | Liver or kidney problems; increased risk of cancer | Discharge from wood preserving factories |
| Picloram | 0.5 | 0.5 | Liver problems | Herbicide runoff |
| Simazine | 0.004 | 0.004 | Problems with blood | Herbicide runoff |
| Styrene | 0.1 | 0.1 | Liver, kidney, and circulatory problems | Discharge from rubber and plastic factories; leaching from landfills |
| Tetrachloroethylene | zero | 0.005 | Liver problems; increased risk of cancer | Leaching from PVC pipes; discharge from factories and dry cleaners |
| Toluene | 1 | 1 | Nervous system, kidney, or liver problems | Discharge from petroleum factories |
| Total Trihalomethanes (TTHMs) | none | 0.1 | Liver, kidney or central nervous system problems; increased risk of cancer | Byproduct of drinking water disinfection |
| Toxaphene | zero | 0.003 | Kidney, liver, or thyroid problems; increased risk of cancer | Runoff/leaching from insecticide used on cotton and cattle |
| 2,4,5-TP (Silvex) | 0.05 | 0.05 | Liver problems | Residue of banned herbicide |
| 1,2,4-Trichlorobenzene | 0.07 | 0.07 | Changes in adrenal glands | Discharge from textile finishing factories |
| 1,1,1-Trichloroethane | 0.2 | 0.2 | Liver, nervous system, or circulatory problems | Discharge from metal degreasing sites and other factories |
| 1,1,2-Trichloroethane | 0.003 | 0.005 | Liver, kidney, or immune system problems | Discharge from industrial chemical factories |
| Trichloroethylene | zero | 0.005 | Liver problems; increased risk of cancer | Discharge from petroleum refineries |
| Vinyl chloride | zero | 0.002 | Increased risk of cancer | Leaching from PVC pipes; discharge from plastic factories |
| Xylenes (total) | 10 | 10 | Nervous system damage | Discharge from petroleum factories; discharge from chemical factories |
| Radionuclides | ||||
| Beta particles and photon emitters | none | 4 millirems per year | Increased risk of cancer | Decay of natural and man-made deposits |
| Gross alpha particle activity | none | 15 picocuries per Liter (pCi/L) | Increased risk of cancer | Erosion of natural deposits |
| Radium 226 and Radium 228 (combined) | none | 5 pCi/L | Increased risk of cancer | Erosion of natural deposits |
| Microorganisms | ||||
| Giardia lamblia | zero | TT | Giardiasis, a gastroenteric disease | Human and animal fecal waste |
| Heterotrophic plate count | N/A | TT | HPC has no health effects, but can indicate how effective treatment is at controlling microorganisms. | n/a |
| Legionella | zero | TT | Legionnaire's Disease, commonly known as pneumonia | Found naturally in water; multiplies in heating systems |
| Total Coliforms (including fecal coliform and E. Coli) | zero | 0.05 | Used as an indicator that other potentially harmful bacteria may be present | Human and animal fecal waste |
| Turbidity | N/A | TT | Turbidity has no health effects but can interfere with disinfection and provide a medium for microbial growth. It may indicate the presence of microbes. | Soil runoff |
| Viruses (enteric) | zero | TT | Gastroenteric disease | Human and animal fecal waste |
TT - Treatment Techniques are required to prevent contamination from microorganisms.
MCL - Maximum Contaminant Level
MCLG - Maximum Contaminant Level Goal