Free EPA Fact Sheets About Drinking Water

Drinking Water Fact Sheets

NATIONAL PRIMARY DRINKING WATER REGULATIONS

These fact sheets are about chemicals that may be found in some public or private drinking water supplies. These chemicals may cause health problems if found in amounts greater than the health standard set by the U. S. EPA.

The consumer version of the fact sheet describes basic information about each contaminant such as: what it is and its health effects; why it is regulated and its drinking water standard; how much is produced and released to the environment (including the top states); how it is detected and removed from drinking water; how consumers will know if it is in drinking water; and, sources of information to learn more about drinking water.

The technical version of the fact sheets contains similar information plus the chemical and physical properties, trade names for the chemical and other regulatory information.

Many consumers are concerned about the possible health effects of Cryptosporidium, a microbial parasite, in their drinking water. EPA and CDC have prepared advice for those with severely compromised immune systems who are concerned about Cryptosporidium.

EPA recently set new standards to strengthen protection from microbial contaminants, including Cryptosporidium. Simultaneously, EPA set standards to strengthen control of disinfection byproducts, potentially harmful contaminants that form when disinfectants (such as chlorine) react with decomposing plant matter and other naturally-occurring materials in water. Clickhere to read more about the Microbial and Disinfectants/Disinfection Byproducts Rules.

E coli is a bacteria that can occur in drinking water. Although most strains of E. coli are harmless and live in the intestines of healthy humans and animals, some can cause illness. Most cases of illness are believed to have come from eating undercooked ground beef, however, some are waterborne.

MTBE is a fuel additive, commonly used in the United States to reduce carbon monoxide and ozone levels caused by auto emissions. Due to its widespread use, reports of MTBE detections in the nation's ground and surface water supplies are increasing. The Office of Water and other EPA offices are working with a panel of leading experts to focus on issues posed by the continued use of MTBE and other oxygenates in gasoline.

Healthadvisories provide information on certain contaminants. Health Advisories are guidance values based on non-cancer health effects for different durations of exposure (e.g., one-day, ten-day, longer-term, and lifetime).

ehso blue lightbar
Ground Water & Drinking WaterPublications

This page provides the following information about our publications:

  • "F" if the publication is a fact sheet;
  • "N" if the publication is new (published since June 1996);
  • the name of the publication;
  • its EPA publication number; and
  • the source of the publication, and the publication number for that source.

Subject Categories
  • Basic Drinking Water Information
  • For Kids and Teachers
  • Drinking Water Standards Program
  • The National Primary Drinking Water Regulations (NPDWR) are legally enforceable primary standards and treatment techniques that apply to public water systems. Primary standards and treatment techniques protect public health by limiting the levels of contaminants in drinking water.

    Printable version: Complete NPDWR Table


    Microorganisms

    Surface Water Treatment Rules

    Ground Water Rule

    Revised Total Coliform Rule And Total Coliform Rule

    Contaminant MCLG1 (mg/L)2 MCL or TT1 (mg/L)2 Potential Health Effects from Long-Term Exposure Above the MCL (unless specified as short-term) Sources of Contaminant in Drinking Water
    Cryptosporidium zero TT3

    Gastrointestinal illness (such as diarrhea, vomiting, and cramps)

    Human and animal fecal waste

    Giardia lamblia zero TT3

    Gastrointestinal illness (such as diarrhea, vomiting, and cramps)

    Human and animal fecal waste

    Heterotrophic plate count (HPC) n/a TT3

    HPC has no health effects; it is an analytic method used to measure the variety of bacteria that are common in water. The lower the concentration of bacteria in drinking water, the better maintained the water system is.

    HPC measures a range of bacteria that are naturally present in the environment

    Legionella zero TT3

    Legionnaire's Disease, a type of pneumonia

    Found naturally in water; multiplies in heating systems

    Total Coliforms (including fecal coliform and E. Coli)

    zero 5.0%4

    Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5

    Coliforms are naturally present in the environment; as well as feces; fecal coliforms and E. coli only come from human and animal fecal waste.

    Turbidity n/a TT3

    Turbidity is a measure of the cloudiness of water. It is used to indicate water quality and filtration effectiveness (such as whether disease-causing organisms are present). Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.

    Soil runoff

    Viruses (enteric) zero TT3

    Gastrointestinal illness (such as diarrhea, vomiting, and cramps)

    Human and animal fecal waste


    Disinfection Byproducts

    Quick reference guide: Stage 1 and 2 Disinfectants and Disinfection Byproducts Rules

    Stage 1 and 2 Rules Summary

    Contaminant MCLG1 (mg/L)2 MCL or TT1 (mg/L)2 Potential Health Effects from Long-Term Exposure Above the MCL (unless specified as short-term) Sources of Contaminant in Drinking Water
    Bromate zero 0.010

    Increased risk of cancer

    Byproduct of drinking water disinfection

    Chlorite 0.8 1.0

    Anemia; infants and young children: nervous system effects

    Byproduct of drinking water disinfection

    Haloacetic acids (HAA5) n/a6 0.060

    Increased risk of cancer

    Byproduct of drinking water disinfection

    Total Trihalomethanes (TTHMs) --> n/a6 ========-->--> 0.080

    Liver, kidney or central nervous system problems; increased risk of cancer

    Byproduct of drinking water disinfection


    Disinfectants

    Quick reference guide: Stage 1 and 2 Disinfectants and Disinfection Byproducts Rules

    Stage 1 and 2 Rules Summary

    Contaminant MCLG1 (mg/L)2 MCL or TT1 (mg/L)2 Potential Health Effects from Long-Term Exposure Above the MCL (unless specified as short-term) Sources of Contaminant in Drinking Water
    Chloramines (as Cl2) MRDLG=41 MRDL=4.01

    Eye/nose irritation; stomach discomfort, anemia

    Water additive used to control microbes

    Chlorine (as Cl2) MRDLG=41 MRDL=4.01

    Eye/nose irritation; stomach discomfort

    Water additive used to control microbes

    Chlorine dioxide (as ClO2) MRDLG=0.81 MRDL=0.81

    Anemia; infants and young children: nervous system effects

    Water additive used to control microbes


    Inorganic Chemicals

    Chemical Contaminant Rules Summary

    Contaminant MCLG1 (mg/L)2 MCL or TT1 (mg/L)2 Potential Health Effects from Long-Term Exposure Above the MCL (unless specified as short-term) Sources of Contaminant in Drinking Water
    Antimony 0.006 0.006

    Increase in blood cholesterol; decrease in blood sugar

    Discharge from petroleum refineries; fire retardants; ceramics; electronics; solder

    Arsenic

    0 0.010 as of 01/23/06

    Skin damage or problems with circulatory systems, and may have increased risk of getting cancer

    Erosion of natural deposits; runoff from orchards, runoff from glass and electronics production wastes

    Asbestos (fiber > 10 micrometers) 7 million fibers per liter (MFL) 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

    Allergic dermatitis

    Discharge from steel and pulp mills; erosion of natural deposits

    Copper 1.3 TT7; Action Level=1.3

    Short term exposure: Gastrointestinal distress

    Long term exposure: Liver or kidney damage

    People with Wilson's Disease should consult their personal doctor if the amount of copper in their water exceeds the action level

    Corrosion of household plumbing systems; erosion of natural deposits

    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 4.0 4.0

    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 TT7; Action Level=0.015

    Infants and children: Delays in physical or mental development; children could show slight deficits in attention span and learning abilities

    Adults: Kidney problems; high blood pressure

    Corrosion of household plumbing systems; erosion of natural deposits

    Mercury (inorganic) 0.002 0.002

    Kidney damage

    Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and croplands

    Nitrate (measured as Nitrogen) 10 10

    Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome.

    Runoff from fertilizer use; leaking from septic tanks, sewage; erosion of natural deposits

    Nitrite (measured as Nitrogen) 1 1

    Infants below the age of six months who drink water containing nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome.

    Runoff from fertilizer use; leaking 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 drug factories


    Organic Chemicals

    Chemical Contaminant Rules Summary

    Contaminant MCLG1 (mg/L)2 MCL or TT1 (mg/L)2 Potential Health Effects from Long-Term Exposure Above the MCL (unless specified as short-term) Sources of Contaminant in Drinking Water
    Acrylamide zero TT8

    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 or reproductive problems

    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 (PAHs) 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, nervous system, or reproductive system

    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

    Discharge 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 drug 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

    Weight loss, liver problems, or possible reproductive difficulties.

    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

    Liver problems

    Residue of banned insecticide

    Epichlorohydrin zero TT8

    Increased cancer risk, and over a long period of time, stomach problems

    Discharge from industrial chemical factories; an impurity of some water treatment chemicals

    Ethylbenzene 0.7 0.7

    Liver or kidneys problems

    Discharge from petroleum refineries

    Ethylene dibromide zero 0.00005

    Problems with liver, stomach, reproductive system, or kidneys; 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 heptachlor

    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 cattle, 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 deficiencies; reproductive or nervous system difficulties; increased risk of cancer

    Runoff from landfills; discharge of waste chemicals

    Pentachlorophenol zero 0.001

    Liver or kidney problems; increased cancer risk

    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, or circulatory system problems

    Discharge from rubber and plastic factories; leaching from landfills

    Tetrachloroethylene zero 0.005

    Liver problems; increased risk of cancer

    Discharge from factories and dry cleaners

    Toluene 1 1

    Nervous system, kidney, or liver problems

    Discharge from petroleum factories

    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 0.20 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 metal degreasing sites and other factories

    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

    Quick Reference Guide

    Radionuclides Rule Information and Summary

    Contaminant MCLG1 (mg/L)2 MCL or TT1 (mg/L)2 Potential Health Effects from Long-Term Exposure Above the MCL (unless specified as short-term) Sources of Contaminant in Drinking Water
    Alpha particles none ---------- zero 15 picocuries per Liter (pCi/L)

    Increased risk of cancer

    Erosion of natural deposits of certain minerals that are radioactive and may emit a form of radiation known as alpha radiation

    Beta particles and photon emitters none ---------- zero 4 millirems per year

    Increased risk of cancer

    Decay of natural and man-made deposits of

    certain minerals that are radioactive and may emit forms of radiation known as photons and beta radiation

    Radium 226 and Radium 228 (combined) none ---------- zero 5 pCi/L

    Increased risk of cancer

    Erosion of natural deposits

    Uranium zero

    30 ug/L as of 12/08/03

    Increased risk of cancer, kidney toxicity Erosion of natural deposits


  • Drinking Water Program Implementation-Public Water System Supervision Program (PWSS)
  • Drinking Water Program Implementation-Protection of Drinking Water Sources
  • Drinking Water State Revolving Loan Fund (DWSRF) and related activities
  • National Drinking Water Advisory Council (NDWAC)
  • Legislation and Program Direction
  • Federal Register Notices
The US EPA OGWDW distributes one free copy of each publication per customer through the Office of Water Resource Center (OWRC) and the National Service Center for Environmental Publications (NSCEP, formerly NCEPI) until supplies are exhausted. Customers can then order them for a fee from the Educational Resources Information Center (ERIC) or the National Technical Information Service (NTIS).

You can send an e-mail order to any of these sources, or call them at:

You can also contact the SafeDrinking Water Hotline (1-800-426-4791) for more information about EPA's drinking water programs.

For more information, contact the Safe Drinking Water Hotline at 1-800-426-4791 via telephone or via email at [email protected] Hardcopies of this publication may be ordered from NCEPI, the Safe Drinking Water Hotline, or the Water Resource Center.

Allergy Store