• Drinking Water Regulation Standards

• Publications about drinking water and groundwater
  
  

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.

• Contaminant Specific Fact Sheets

• Consumer Version

  Inorganic Chemicals

  Synthetic Organic Chemicals

  Volatile Organic Chemicals

Technical Version

Inorganic Chemicals

Synthetic Organic Chemicals

Volatile Organic Chemicals

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).

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.

• 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.

  • Microorganisms
  • Disinfectants
  • Disinfection Byproducts
  • Inorganic Chemicals
  • Organic Chemicals
  • Radionuclides

  Printable version: Complete NPDWR Table

  ---

  Microorganisms

  Surface Water Treatment Rules

  Ground Water Rule

  Revised Total Coliform Rule And Total Coliform Rule

  Contaminant

  MCLG ¹ ( mg/L ) ²

  MCL or TT ¹ ( 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

  TT ³

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

  Human and animal fecal waste

  Giardia lamblia

  zero

  TT ³

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

  Human and animal fecal waste

  Heterotrophic plate count ( HPC )

  n/a

  TT ³

  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

  TT ³

  Legionnaire's Disease, a type of pneumonia

  Found naturally in water; multiplies in heating systems

  Total Coliforms (including fecal coliform and E. Coli )

  • Quick reference guide
  • Rule Summary

  zero

  5.0% ⁴

  Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present ⁵

  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

  TT ³

  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

  TT ³

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

  Human and animal fecal waste

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  Disinfection Byproducts

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

  Stage 1 and 2 Rules Summary

  Contaminant	MCLG 1 ( mg/L ) 2	MCL or TT 1 ( 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/a 6	0.060	Increased risk of cancer	Byproduct of drinking water disinfection
  Total Trihalomethanes ( TTHMs )	--> n/a 6	========-->--> 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	MCLG 1 ( mg/L ) 2	MCL or TT 1 ( 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 Cl 2 )	MRDLG =4 1	MRDL =4.0 1	Eye/nose irritation; stomach discomfort, anemia	Water additive used to control microbes
  Chlorine (as Cl 2 )	MRDLG =4 1	MRDL =4.0 1	Eye/nose irritation; stomach discomfort	Water additive used to control microbes
  Chlorine dioxide (as ClO 2 )	MRDLG =0.8 1	MRDL =0.8 1	Anemia; infants and young children: nervous system effects	Water additive used to control microbes

  ---

  Inorganic Chemicals

  Chemical Contaminant Rules Summary

  Contaminant

  MCLG ¹ ( mg/L ) ²

  MCL or TT ¹ ( 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

  • Quick reference guide
  • Consumer fact sheet

  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

  TT ⁷ ; 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

  • Quick reference guide
  • Rule information

  zero

  TT ⁷ ; 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

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  Organic Chemicals

  Chemical Contaminant Rules Summary

  Contaminant	MCLG 1 ( mg/L ) 2	MCL or TT 1 ( 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	TT 8	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	TT 8	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

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  Radionuclides

  Quick Reference Guide

  Radionuclides Rule Information and Summary

  Contaminant	MCLG 1 ( mg/L ) 2	MCL or TT 1 ( 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

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• 
  
• Drinking Water Program Implementation-Public Water System Supervision Program (PWSS)
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You can send an e-mail order to any of these sources, or call them at:

• NSCEP ncepi.mail@epa.gov (800) 490-9198
• WRC center.water-resource@epa.gov (202) 260-7786 (Voicemail) or (202) 260-0386 (Fax)
• ERIC ericse@osu.edu (800) 276-0462
• NTIS orders@ntis.fedworld.gov (800) 553-6847