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Drinking Water Health Advisories
2006 Edition
Last update: August 2006; EPA 822-R-06-013
Print Version of these Tables (PDF) (18 pp., 95 K, About PDF)
- Introduction
- Definitions
- Abbreviations
- Drinking Water Standards, Organics
- Drinking Water Standards, Inorganics
- Drinking Water Standards, Radionuclides
- Secondary Drinking Water Regulations
- Microbiology
- Drinking Water Advisory Table
Introduction
The Drinking Water Standards and Health Advisories Tables are revised periodically by EPA’s Office of Water in order to update RfD and Cancer values so that they are consistent with the most current Agency assessments of chemical contaminants that may occur in drinking water and to introduce new Health Advisories. The following information should be kept in mind when using the 2006 Edition of the Tables:
Reference dose (RfD) values are updated to reflect the values in the Integrated Risk Information System (IRIS) and the Office of Pesticide Programs (OPP) Reregistration Eligibility Decisions (RED) Documents. The Drinking Water Equivalent Level (DWEL) has been adjusted accordingly. Thus, both the RfD and DWEL in the Tables differ from the values in the Health Advisory document when the IRIS or OPP RfD is more recent than the Health Advisory document value. RfD values from IRIS that differ from the values in the Health Advisory documents are presented in BOLD type. Values derived from the REDs are given in BOLD italics. For unregulated chemicals with a recent IRIS or OPP RfD, the lifetime Health Advisory is calculated from the DWEL using the relative source contribution value published in the Health Advisory document. For regulated chemicals, no lifetime value is provided in the Tables when the revised lifetime value would differ from the Maximum Contaminant Level Goal (MCLG).
The cancer group designation or cancer classification and 10-4 cancer risk values reflect those presently in IRIS or in the OPP RED. New IRIS cancer designations and 10-4 cancer risk values are presented in BOLD type and those derived from the REDs are in BOLD italics.
IRIS Toxicological Reviews | OPP REDs
In some cases there is a Health Advisory value for a contaminant but there is no reference to a Health Advisory document. These Health Advisory values can be found in the Drinking Water Criteria Document for the contaminant.
With a few exceptions, the RfDs, Health Advisory, and cancer risk values have been rounded to one significant figure following the convention adopted by IRIS.
Copies of these Tables may be ordered free of charge from
SAFE DRINKING WATER HOTLINE
1-800-426-4791
Monday thru Friday, 9:00 AM to 5:30 PM EST
Definitions
The following definitions for terms used in the Tables are not all-encompassing, and should not be construed to be "official" definitions. They are intended to assist the user in understanding terms found on the following pages.
Action Level: The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow. It is the level of lead or copper which, if exceeded in over 10% of the homes tested, triggers treatment for corrosion control.
Cancer Classification: A descriptive weight-of-evidence judgment as to the likelihood that an agent is a human carcinogen and the conditions under which the carcinogenic effects may be expressed. Under the 2005 EPA Guidelines for Carcinogen Risk Assessment, descriptive terms for carcinogenicity replace the earlier alpha numeric Cancer Group designations (US EPA 1986 guidelines). The suggested descriptive terms are as follows:
- Carcinogenic to humans (H)
- Likely to be carcinogenic to humans (L)
- Likely to be carcinogenic above a specified dose but not likely to be carcinogenic below that dose because a key event in tumor formation does not occur below that dose (L/N)
- Suggestive evidence of carcinogenic potential (S)
- Inadequate information to assess carcinogenic potential (I)
- Not likely to be carcinogenic to humans (N)
The letter abbreviations provided parenthetically above are now used in the Tables in place of the prior alpha numeric identifiers for chemicals that have been evaluated under the new guidelines (the 2005 guidelines or the 1996 and 1999 draft guidelines).
Cancer Group: A qualitative weight-of-evidence judgement as to the likelihood that a chemical may be a carcinogen for humans. Each chemical was placed into one of the following five categories (US EPA 1986 guidelines). The Cancer Group designation are given in the Tables for chemicals that have not yet been evaluated under the new guidelines.
Group Category:
- A: Human carcinogen
- B: Probable human carcinogen —
- B1: indicates limited human evidence
- B2: indicates sufficient evidence in animals and inadequate or no evidence in humans
- C: Possible human carcinogen
- D: Not classifiable as to human carcinogenicity
- E: Evidence of noncarcinogenicity for humans
10-4 Cancer Risk: The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000.
Drinking Water Advisory: A nonregulatory concentration of a contaminant in water that is likely to be without adverse effects on health and aesthetics.
DWEL: Drinking Water Equivalent Level. A lifetime exposure concentration protective of adverse, non-cancer health effects, that assumes all of the exposure to a contaminant is from drinking water.
HA: Health Advisory. An estimate of acceptable drinking water levels for a chemical substance based on health effects information; a Health Advisory is not a legally enforceable Federal standard, but serves as technical guidance to assist Federal, State, and local officials.
One-Day HA: The concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to one day of exposure. The One-Day HA is normally designed to protect a 10-kg child consuming 1 liter of water per day.
Ten-Day HA: The concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure. The Ten-Day HA is also normally designed to protect a 10-kg child consuming 1 liter of water per day.
Lifetime HA: The concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for a lifetime of exposure. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of water per day. The Lifetime HA for Group C carcinogens includes an adjustment for possible carcinogenicity.
MCLG: Maximum Contaminant Level Goal. A non-enforceable health goal which is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety.
MCL: Maximum Contaminant Level. The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLG as feasible using the best available analytical and treatment technologies and taking cost into consideration. MCLs are enforceable standards.
RfD: Reference Dose. An estimate (with uncertainty spanning perhaps an order of magnitude) of a daily oral exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime.
SDWR: Secondary Drinking Water Regulations. Non-enforceable Federal guidelines regarding cosmetic effects (such as tooth or skin discoloration) or aesthetic effects (such as taste, odor, or color) of drinking water.
TT: Treatment Technique. A required process intended to reduce the level of a contaminant in drinking water.
Abbreviations
- D: Draft
- F: Final
- NA: Not Applicable
- NOAEL: No-Observed-Adverse-Effect Level
- OPP: EPA's Office of Pesticide Programs
- P: Proposed
- Reg: Regulation
- TT: Treatment Technique
Drinking Water Standards, Organics
| Chemicals | CASRN Number | Standards | Status HA Document | Health Advisories | Cancer Descriptor1 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Status Reg. | MCLG (mg/L) | MCL (mg/L) | 10-kg Child | |||||||||
| One-day (mg/L) | Ten-day (mg/L) | RfD (mg/kg/day) | DWEL (mg/L) | Lifetime (mg/L) | mg/L at 10-4 Cancer Risk | |||||||
| Acenaphthene | 83-32-9 | — | — | — | — | — | — | 0.06 | 2 | — | — | — |
| Acifluorfen (sodium) | 62476-59-9 | — | — | F'88 | 2 | 2 | 0.01 | 0.4 | — | 0.1 | L/N | |
| Acrylamide | 79-06-1 | F | zero | TT2 | F'87 | 1.5 | 0.3 | 0.0002 | 0.007 | — | 0.0008 | B2 |
| Acrylonitrile | 107-13-1 | — | — | — | — | — | — | — | — | 0.006 | B1 | |
| Alachlor | 15972-60-8 | F | zero | 0.002 | F'88 | 0.1 | 0.1 | 0.01 | 0.4 | — | 0.04 | B2 |
| Aldicarb3 | 116-06-3 | F4 | 0.001 | 0.003 | F'95 | 0.01 | 0.01 | 0.001 | 0.035 | 0.007 | — | D |
| Aldicarb sulfone3 | 1646-88-4 | F4 | 0.001 | 0.002 | F'95 | 0.01 | 0.01 | 0.001 | 0.035 | 0.007 | — | D |
| Aldicarb sulfoxide3 | 1646-87-3 | F4 | 0.001 | 0.004 | F'95 | 0.01 | 0.01 | 0.001 | 0.035 | 0.007 | — | D |
| Aldrin | 309-00-2 | — | — | — | F'92 | 0.0003 | 0.0003 | 0.00003 | 0.001 | — | 0.0002 | B2 |
| Ametryn | 834-12-8 | — | — | — | F'88 | 9 | 9 | 0.009 | 0.3 | 0.06 | — | D |
| Ammonium sulfamate | 7773-06-0 | — | — | — | F'88 | 20 | 20 | 0.2 | 8 | 2 | — | D |
| Anthracene (PAH)5 | 120-12-7 | — | — | — | — | — | — | 0.3 | 10 | — | — | D |
| Atrazine | 1912-24-9 | F | 0.003 | 0.003 | F'88 | — | — | 0.02 | 0.7 | — | — | N |
| Baygon | 114-26-1 | — | — | — | F'88 | 0.04 | 0.04 | 0.004 | 0.1 | 0.003 | — | C |
| Bentazon | 25057-89-0 | — | — | — | F'99 | 0.3 | 0.3 | 0.03 | 1 | 0.2 | — | E |
| Benz[a]anthracene (PAH) | 56-55-3 | — | — | — | — | — | — | — | — | — | — | B2 |
| Benzene | 71-43-2 | F | zero | 0.005 | F'87 | 0.2 | 0.2 | 0.004 | 0.1 | — | 0.1 | H |
| Benzo[a]pyrene (PAH) | 50-32-8 | F | zero | 0.0002 | — | — | — | — | — | — | 0.0005 | B2 |
| Benzo[b]fluoranthene (PAH) | 205-99-2 | — | — | — | — | — | — | — | — | — | — | B2 |
| Benzo[g,h,i]perylene (PAH) | 191-24-2 | — | — | — | — | — | — | — | — | — | — | D |
| Benzo[k]fluoranthene (PAH) | 207-08-9 | — | — | — | — | — | — | — | — | — | — | B2 |
| bis-2-Chloroisopropyl ether | 39638-32-9 | — | — | — | F'89 | 4 | 4 | 0.04 | 1 | 0.3 | — | D |
| Bromacil | 314-40-9 | — | — | — | F'88 | 5 | 5 | 0.1 | 3.5 | 0.07 | — | C |
| Bromobenzene | 108-86-1 | — | — | — | D'86 | 4 | 4 | — | — | — | — | D |
| Bromochloromethane | 74-97-5 | — | — | — | F'89 | 50 | 1 | 0.01 | 0.5 | 0.09 | — | D |
| Bromodichloromethane (THM) | 75-27-4 | F | zero | 0.081 | — | 1 | 0.6 | 0.003 | 0.1 | — | 0.1 | L |
| Bromoform (THM) | 75-25-2 | F | zero | 0.081 | — | 5 | 0.2 | 0.03 | 1 | — | 0.8 | L |
| Bromomethane | 74-83-9 | — | — | — | D'89 | 0.1 | 0.1 | 0.001 | 0.05 | 0.01 | — | D |
| Butyl benzyl phthalate | 85-68-7 | — | — | — | — | — | — | 0.2 | 7 | — | — | C |
| Butylate | 2008-41-5 | — | — | — | F'89 | 2 | 2 | 0.05 | 2 | 0.4 | — | D |
| Carbaryl | 63-25-2 | — | — | — | F'88 | 1 | 1 | 0.01 | 0.4 | — | 4 | L |
| Carbofuran | 1563-66-2 | F | 0.04 | 0.04 | F'87 | — | — | 0.00006 | — | — | — | N |
| Carbon tetrachloride | 56-23-5 | F | zero | 0.005 | F'87 | 4 | 0.2 | 0.0007 | 0.03 | — | 0.03 | B2 |
| Carboxin | 5234-68-4 | — | — | — | F'88 | 1 | 1 | 0.1 | 3.5 | 0.7 | — | D |
| Chloramben | 133-90-4 | — | — | — | F'88 | 3 | 3 | 0.015 | 0.5 | 0.1 | — | D |
| Chlordane | 57-74-9 | F | zero | 0.002 | F'87 | 0.06 | 0.06 | 0.0005 | 0.02 | — | 0.01 | B2 |
| Chloroform (THM) | 67-66-3 | F | 0.07 | 0.086 | — | 4 | 4 | 0.01 | 0.35 | 0.07 | — | L/N |
| Chloromethane | 74-87-3 | — | — | — | F'89 | 9 | 0.4 | 0.004 | 0.1 | 0.03 | — | D |
| Chlorophenol (2-) | 95-57-8 | — | — | — | D'94 | 0.5 | 0.5 | 0.005 | 0.2 | 0.04 | — | D |
| Chlorothalonil | 1897-45-6 | — | — | — | F'88 | 0.2 | 0.2 | 0.015 | 0.5 | — | 0.15 | B2 |
| Chlorotoluene o- | 95-49-8 | — | — | — | F'89 | 2 | 2 | 0.02 | 0.7 | 0.1 | — | D |
| Chlorotoluene p- | 106-43-4 | — | — | — | F'89 | 2 | 2 | 0.02 | 0.7 | 0.1 | — | D |
| Chlorpyrifos | 2921-88-2 | — | — | — | F'92 | 0.03 | 0.03 | 0.0003 | 0.01 | 0.002 | — | D |
| Chrysene (PAH) | 218-01-9 | — | — | — | — | — | — | — | — | — | — | B2 |
| Cyanazine | 21725-46-2 | — | — | — | D'96 | 0.1 | 0.1 | 0.002 | 0.07 | 0.001 | — | |
| Cyanogen chloride7 | 506-77-4 | — | — | — | — | 0.05 | 0.05 | 0.05 | 2 | — | — | D |
| 2,4-D (2,4-dichlorophenoxyacetic acid) | 94-75-7 | F | 0.07 | 0.07 | F'87 | 1 | 0.3 | 0.005 | 0.2 | — | — | D |
| DCPA (Dacthal) | 1861-32-1 | — | — | — | F'88 | 80 | 80 | 0.01 | 0.35 | 0.07 | — | C |
| Dalapon (sodium salt) | 75-99-0 | F | 0.2 | 0.2 | F'89 | 3 | 3 | 0.03 | 0.9 | 0.2 | — | D |
| Di(2-ethylhexyl)adipate | 103-23-1 | F | 0.4 | 0.4 | — | 20 | 20 | 0.6 | 20 | 0.4 | 3 | C |
| Di(2-ethylhexyl)phthalate | 117-81-7 | F | zero | 0.006 | — | — | — | 0.02 | 0.7 | — | 0.3 | B2 |
| Diazinon | 333-41-5 | — | — | — | F'88 | 0.02 | 0.02 | 0.0002 | 0.007 | 0.001 | — | E |
| Dibromochloromethane (THM) | 124-48-1 | F | 0.06 | 0.086 | — | 0.6 | 0.6 | 0.02 | 0.7 | 0.06 | 0.08 | S |
| Dibromochloropropane (DBCP) | 96-12-8 | F | zero | 0.0002 | F'87 | 0.2 | 0.05 | — | — | — | 0.003 | B2 |
| Dibutyl phthalate | 84-74-2 | — | — | — | — | — | — | 0.1 | 4 | — | — | D |
| Dicamba | 1918-00-9 | — | — | — | F'88 | — | — | 0.5 | 18 | 4 | — | N |
| Dichloroacetic acid | 76-43-6 | F | zero | 0.068 | — | 5 | 5 | 0.004 | 0.1 | — | 0.07 | L |
| Dichlorobenzene o- | 95-50-1 | F | 0.6 | 0.6 | F'87 | 9 | 9 | 0.09 | 3 | 0.6 | — | D |
| Dichlorobenzene -9 | 541-73-1 | — | — | — | F'87 | 9 | 9 | 0.09 | 3 | 0.6 | — | D |
| Dichlorobenzene p- | 106-46-7 | F | 0.075 | 0.075 | F'87 | 11 | 11 | 0.1 | 4 | 0.075 | — | C |
| Dichlorodifluoromethane | 75-71-8 | — | — | — | F'89 | 40 | 40 | 0.2 | 5 | 1 | — | D |
| Dichloroethane (1,2-) | 107-06-2 | F | zero | 0.005 | F'87 | 0.7 | 0.7 | — | — | — | 0.04 | B2 |
| Dichloroethylene (1,1-) | 75-35-4 | F | 0.007 | 0.007 | F'87 | 2 | 1 | 0.05 | 2 | — | — | S |
| Dichloroethylene (cis-1,2-) | 156-59-2 | F | 0.07 | 0.07 | F'90 | 4 | 1 | 0.01 | 0.35 | 0.07 | — | D |
| Dichloroethylene (trans-1,2-) | 156-60-5 | F | 0.1 | 0.1 | F'87 | 20 | 1 | 0.02 | 0.7 | 0.1 | — | D |
| Dichloromethane | 75-09-2 | F | zero | 0.005 | D'93 | 10 | 2 | 0.06 | 2 | — | 0.5 | B2 |
| Dichlorophenol (2,4-) | 120-83-2 | — | — | — | D'94 | 0.03 | 0.03 | 0.003 | 0.1 | 0.02 | — | E |
| Dichloropropane (1,2-) | 78-87-5 | F | zero | 0.005 | F'87 | — | 0.09 | — | — | — | 0.06 | B2 |
| Dichloropropene (1,3-) | 542-75-6 | — | — | — | F'88 | 0.03 | 0.03 | 0.03 | 1 | — | 0.04 | L |
| Dieldrin | 60-57-1 | — | — | — | F'88 | 0.0005 | 0.0005 | 0.00005 | 0.002 | — | 0.0002 | B2 |
| Diethyl phthalate | 84-66-2 | — | — | — | — | — | — | 0.8 | 30 | — | — | D |
| Diisopropyl methylphosphonate | 1445-75-6 | — | — | — | F '89 | 8 | 8 | 0.08 | 3 | 0.6 | — | D |
| Dimethrin | 70-38-2 | — | — | - | F '88 | 10 | 10 | 0.3 | 10 | 2 | — | D |
| Dimethyl methylphosphonate | 756-79-6 | — | — | - | F '92 | 2 | 2 | 0.2 | 7 | 0.1 | 0.7 | C |
| Dimethyl phthalate | 131-11-3 | — | — | - | — | — | — | — | — | — | — | D |
| Dinitrobenzene (1,3-) | 99-65-0 | — | — | - | F '91 | 0.04 | 0.04 | 0.0001 | 0.005 | 0.001 | — | D |
| Dinitrotoluene (2,4-) | 121-14-2 | — | — | - | F '92 | 0.50 | 0.50 | 0.002 | 0.1 | — | 0.005 | B2 |
| Dinitrotoluene (2,6-) | 606-20-2 | — | — | - | F '92 | 0.4 | 0.4 | 0.001 | 0.04 | — | 0.005 | B2 |
| Dinitrotoluene (2,6 & 2,4)10 | — | — | - | F '92 | — | — | — | — | — | 0.005 | B2 | |
| Dinoseb | 88-85-7 | F | 0.007 | 0.007 | F '88 | 0.3 | 0.3 | 0.001 | 0.035 | 0.007 | — | D |
| Dioxane p- | 123-91-1 | — | — | - | F '87 | 4 | 0.4 | — | — | — | 0.3 | B2 |
| Diphenamid | 957-51-7 | — | — | - | F '88 | 0.3 | 0.3 | 0.03 | 1 | 0.2 | — | D |
| Diquat | 85-00-7 | F | 0.02 | 0.02 | — | — | — | 0.005 | 0.02 | — | — | E |
| Disulfoton | 298-04-4 | — | — | - | F '88 | 0.01 | 0.01 | 0.0001 | 0.0035 | 0.0007 | — | E |
| Dithiane (1,4-) | 505-29-3 | — | — | - | F '92 | 0.4 | 0.4 | 0.01 | 0.4 | 0.08 | — | D |
| Diuron | 330-54-1 | — | — | - | F '88 | 1 | 1 | 0.003 | 0.1 | — | 0.2 | L |
| Endothall | 145-73-3 | F | 0.1 | 0.1 | F '88 | 0.8 | 0.8 | 0.007 | 0.25 | 0.05 | — | N |
| Endrin | 72-20-8 | F | 0.002 | 0.002 | F '87 | 0.02 | 0.005 | 0.0003 | 0.01 | 0.002 | — | D |
| Epichlorohydrin | 106-89-8 | F | zero | TT11 | F '87 | 0.1 | 0.1 | 0 | 0.07 | — | 0.3 | B2 |
| Ethylbenzene | 100-41-4 | F | 0.7 | 0.7 | F '87 | 30 | 3 | 0.1 | 3 | 0.7 | — | D |
| Ethylene dibromide (EDB)12 | 106-93-4 | F | zero | 0.00005 | F '87 | 0.008 | 0.008 | 0.009 | 0.3 | — | 0.002 | L |
| Ethylene glycol | 107-21-1 | — | — | - | F '87 | 20 | 6 | 2 | 70 | 14 | — | D |
| Ethylene Thiourea (ETU) | 96-45-7 | — | — | - | F '88 | 0.3 | 0.3 | 0.00008 | 0.003 | — | 0.02 | B2 |
| Fenamiphos | 22224-92-6 | — | — | — | F '88 | 0.009 | 0.009 | 0.0001 | 0.0035 | 0.0007 | — | E |
| Fluometuron | 2164-17-2 | — | — | — | F '88 | 2 | 2 | 0.01 | 0.5 | 0.09 | D | |
| Fluorene (PAH) | 86-73-7 | — | — | - | — | — | — | 0.04 | 1 | — | — | D |
| Fonofos | 944-22-9 | — | — | - | F '88 | 0.02 | 0.02 | 0.002 | 0.07 | 0.01 | — | N |
| Formaldehyde | 50-00-0 | — | — | - | D '93 | 10 | 5 | 0.2 | 7 | 1 | — | B113 |
| Glyphosate | 1071-83-6 | F | 0.7 | 0.7 | F '88 | 20 | 20 | 2 | 70 | — | — | D |
| Heptachlor | 76-44-8 | F | zero | 0.0004 | F '87 | 0.01 | 0.01 | 0.0005 | 0.02 | — | 0.0008 | B2 |
| Heptachlor epoxide | 1024-57-3 | F | zero | 0.0002 | F '87 | 0.01 | — | 0.00001 | 0.0004 | — | 0.0004 | B2 |
| Hexachlorobenzene | 118-74-1 | F | zero | 0.001 | F '87 | 0.05 | 0.05 | 0.0008 | 0.03 | — | 0.002 | B2 |
| Hexachlorobutadiene14 | 87-68-3 | — | — | - | — | 0.3 | 0.3 | 0 .0003 | 0.01 | — | 0.09 | L |
| Hexachlorocyclopentadiene | 77-47-4 | F | 0.05 | 0.05 | — | — | — | 0.006 | 0.2 | — | — | N |
| Hexachloroethane | 67-72-1 | — | — | - | F '91 | 5 | 5 | 0.001 | 0.04 | 0 | 0.3 | C |
| Hexane (n-) | 110-54-3 | — | — | - | F '87 | 10 | 4 | — | — | — | — | I |
| Hexazinone | 51235-04-2 | — | — | - | F '96 | 3 | 2 | 0.05 | 2 | 0.4 | — | D |
| HMX15 | 2691-41-0 | — | — | - | F '88 | 5 | 5 | 0.05 | 2 | 0.4 | — | D |
| Indeno[1,2,3,-c,d]pyrene (PAH) | 193-39-5 | — | — | - | — | — | — | — | — | — | — | B2 |
| Isophorone | 78-59-1 | — | — | - | F '92 | 15 | 15 | 0.2 | 7 | 0.1 | 4 | C |
| Isopropyl methylphosphonate | 1832-54-8 | — | — | - | F '92 | 30 | 30 | 0.1 | 3.5 | 0.7 | — | D |
| Isopropylbenzene (cumene) | 98-82-8 | — | — | - | D '87 | 11 | 11 | 0.1 | 4 | — | — | D |
| Lindane16 | 58-89-9 | F | 0 | 0.0002 | F '87 | 1 | 1 | 0.005 | 0.2 | — | — | S |
| Malathion | 121-75-5 | — | — | - | F '92 | 0.2 | 0.2 | 0.02 | 0.8 | 0.1 | — | D |
| Maleic hydrazide | 123-33-1 | — | — | - | F '88 | 10 | 10 | 0.5 | 20 | 4 | — | D |
| MCPA17 | 94-74-6 | — | — | - | F '88 | 0.1 | 0.1 | 0.004 | 0.14 | 0.03 | — | N |
| Methomyl | 16752-77-5 | — | — | - | F '88 | 0.3 | 0.3 | 0.025 | 0.9 | 0.2 | — | E |
| Methoxychlor | 72-43-5 | F | 0.04 | 0.04 | F '87 | 0.05 | 0.05 | 0.005 | 0.2 | 0.04 | — | D |
| Methyl ethyl ketone | 78-93-3 | — | — | - | F '87 | 75 | 7.5 | 0.6 | 20 | 4 | — | D |
| Methyl parathion | 298-00-0 | — | — | — | F '88 | 0.3 | 0.3 | 0.0002 | 0.007 | 0.001 | — | N |
| Metolachlor | 51218-45-2 | — | — | — | F '88 | 2 | 2 | 0.1 | 3.5 | 0.7 | — | C |
| Metribuzin | 21087-64-9 | — | — | - | F '88 | 5 | 5 | 0.01 | 0.35 | 0.07 | — | D |
| Monochloroacetic acid | 79-11-8 | F | 0.03 | 0.068 | — | 0.2 | 0.2 | 0.01 | 0.35 | 0.07 | — | I |
| Monochlorobenzene | 108-90-7 | F | 0.1 | 0.1 | F '87 | 4 | 4 | 0.02 | 0.7 | 0.1 | — | D |
| Naphthalene | 91-20-3 | — | — | - | F '90 | 0.5 | 0.5 | 0.02 | 0.7 | 0.1 | — | I |
| Nitrocellulose18 | 9004-70-0 | — | — | - | F '88 | — | — | — | — | — | — | — |
| Nitroguanidine | 556-88-7 | — | — | - | F '90 | 10 | 10 | 0.1 | 3.5 | 0.7 | — | D |
| Nitrophenol p- | 100-02-7 | — | — | - | F '92 | 0.8 | 0.8 | 0.008 | 0.3 | 0.06 | — | D |
| Oxamyl (Vydate) | 23135-22-0 | F | 0.2 | 0.2 | F '05 | 0.01 | 0.01 | 0.001 | 0.035 | — | N | |
| Paraquat | 1910-42-5 | — | — | - | F '88 | 0.1 | 0.1 | 0.0045 | 0.2 | 0.03 | — | C |
| Pentachlorophenol | 87-86-5 | F | zero | 0.001 | F '87 | 1 | 0.3 | 0.03 | 1 | — | 0.03 | B2 |
| Phenanthrene (PAH) | 85-01-8 | — | — | - | — | — | — | — | — | — | — | D |
| Phenol | 108-95-2 | — | — | - | D '92 | 6 | 6 | 0.3 | 11 | 2 | — | D |
| Picloram | 1918-02-1 | F | 0.5 | 0.5 | F '88 | 20 | 20 | 0.02 | 0.7 | — | — | D |
| Polychlorinated biphenyls (PCBs) | 1336-36-3 | F | zero | 0.0005 | D '93 | — | — | — | — | — | 0.01 | B2 |
| Prometon | 1610-18-0 | — | — | - | F '88 | 0.2 | 0.2 | 0.02 | 0.5 | 0.1 | — | D |
| Pronamide | 23950-58-5 | — | — | - | F '88 | 0.8 | 0.8 | 0.08 | 3 | — | 0.2 | B2 |
| Propachlor | 1918-16-7 | — | — | - | F '88 | 0.5 | 0.5 | 0.05 | 2 | — | 0.1 | L |
| Propazine | 139-40-2 | — | — | - | F '88 | — | — | 0.02 | 0.7 | 0.1 | — | N |
| Propham | 122-42-9 | — | — | - | F '88 | 5 | 5 | 0.02 | 0.6 | 0.1 | — | D |
| Pyrene (PAH) | 129-00-0 | — | — | - | — | — | — | 0.03 | — | — | — | D |
| RDX19 | 121-82-4 | — | — | - | F '88 | 0.1 | 0.1 | 0 | 0.1 | 0.002 | 0.03 | C |
| Simazine | 122-34-9 | F | 0.004 | 0.004 | F '88 | — | — | 0.02 | 0.7 | — | — | N |
| Styrene | 100-42-5 | F | 0.1 | 0.1 | F '87 | 20 | 2 | 0.2 | 7 | 0.1 | — | C |
| 2,4,5-T (Trichlorophenoxy-acetic acid) | 93-76-5 | — | — | — | F '88 | 0.8 | 0.8 | 0.01 | 0.35 | 0.07 | — | D |
| 2,3,7,8-TCDD (Dioxin) | 1746-01-6 | F | zero | 3E-008 | F ’87 | 1E-006 | 1E-007 | 1E-009 | 4E-008 | — | 2E-008 | B2 |
| Tebuthiuron | 34014-18-1 | — | — | - | F '88 | 3 | 3 | 0.07 | 2 | 0.5 | — | D |
| Terbacil | 5902-51-2 | — | — | - | F '88 | 0.3 | 0.3 | 0.01 | 0.4 | 0.09 | — | E |
| Terbufos | 13071-79-9 | — | — | - | F '88 | 0.005 | 0.005 | 0.00005 | 0.002 | 0.0004 | — | D |
| Tetrachloroethane (1,1,1,2-) | 630-20-6 | — | — | - | F '89 | 2 | 2 | 0.03 | 1 | 0.07 | 0.1 | C |
| Tetrachloroethane (1,1,2,2-) | 79-34-5 | — | — | - | F '89 | 0.04 | 0.04 | 0.00005 | 0.002 | 0.0003 | 0.02 | C |
| Tetrachloroethylene1 | 127-18-4 | F | zero | 0.005 | F '87 | 2 | 2 | 0.01 | 0.5 | 0.01 | — | — |
| Trichlorofluoromethane | 75-69-4 | — | — | - | F '89 | 7 | 7 | 0.3 | 10 | 2 | — | D |
| Toluene | 108-88-3 | F | 1 | 1 | D '93 | 20 | 2 | 0.08 | 3 | — | — | I |
| Toxaphene | 8001-35-2 | F | zero | 0.003 | F '96 | 0.004 | 0.004 | 0.00004 | 0.01 | — | 0.003 | B2 |
| 2,4,5-TP (Silvex) | 93-72-1 | F | 0.05 | 0.05 | F '88 | 0.2 | 0.2 | 0.008 | 0.3 | 0.05 | — | D |
| Trichloroacetic acid | 76-03-9 | F | 0.02 | 0.068 | — | 3 | 3 | 0.03 | 1 | 0.02 | — | S |
| Trichlorobenzene (1,2,4-) | 120-82-1 | F | 0.07 | 0.07 | F '89 | 0.1 | 0.1 | 0.01 | 0.35 | 0.07 | — | D |
| Trichlorobenzene (1,3,5-) | 108-70-3 | — | — | - | F '89 | 0.6 | 0.6 | 0.006 | 0.2 | 0.04 | — | D |
| Trichloroethane (1,1,1-) | 71-55-6 | F | 0.2 | 0.2 | F '87 | 100 | 40 | 0.035 | 1 | 0.2 | — | D |
| Trichloroethane (1,1,2-) | 79-00-5 | F | 0.003 | 0.005 | F '89 | 0.6 | 0.4 | 0.004 | 0.1 | 0.003 | 0.06 | C |
| Trichloroethylene7 | 79-01-6 | F | zero | 0.005 | F '87 | — | — | 0.007 | 0.2 | — | 0.3 | B2 |
| Trichlorophenol (2,4,6-) | 06/02/88 | — | — | - | D '94 | 0.03 | 0.03 | 0.0003 | 0.01 | — | 0.3 | B2 |
| Trichloropropane (1,2,3-) | 96-18-4 | — | — | - | F '89 | 0.6 | 0.6 | 0.006 | 0.2 | 0.04 | — | — |
| Trifluralin | 1582-09-8 | — | — | - | F '90 | 0.08 | 0.08 | 0.02 | 0.7 | 0.01 | 0.4 | C |
| Trimethylbenzene (1,2,4-) | 95-63-6 | — | — | - | D '87 | — | — | — | — | — | — | D |
| Trimethylbenzene (1,3,5-) | 108-67-8 | — | — | - | D '87 | 10 | — | — | — | — | — | D |
| Trinitroglycerol | 55-63-0 | — | — | - | F '87 | 0.005 | 0.005 | — | — | 0.005 | 0.2 | — |
| Trinitrotoluene (2,4,6-) | 118-96-7 | — | — | - | F '89 | 0.02 | 0.02 | 0.0005 | 0.02 | 0.002 | 0.1 | C |
| Vinyl chloride | 75-01-4 | F | zero | 0.002 | F '87 | 3 | 3 | 0.003 | 0.1 | — | 0.002 | H |
| Xylenes | 1330-20-7 | F | 10 | 10 | D '93 | 40 | 40 | 0.2 | 7 | — | — | I |
Footnotes, Organics
1 Chemicals evaluated under the 2005 Cancer Guidelines or the 1996 or 1999 drafts are demoted by an abbreviation for their weight-of-the-evidence descriptor. If the agency has not completed a new assessment for the chemical, the 1986 Guidelines Group designation is given in the Cancer Descriptor column.
2 When acrylamide is used in drinking water systems, the combination (or product) of dose and monomer level shall not exceed that equivalent to a polyacrylamide polymer containing 0.05% monomer dosed at 1 mg/L.
3 The MCL value for any combination of two or more of these three chemicals should not exceed 0.007 mg/L because of a similar mode of action.
4 Administrative stay of the effective date.
5 PAH = Polycyclic aromatic hydrocarbon.
6 1998 Final Rule for Disinfectants and Disinfection By-products: The total for trihalomethanes (THM) is 0.08 mg/L.
7 Under review.
8 1998 Final Rule for Disinfectants and Disinfection By-products: The total for five haloacetic acids is 0.06 mg/L.
9 The values for m-dichlorobenzene are based on data for o-dichlorobenzene.
10 Technical grade.
11 When epichlorohydrin is used in drinking water systems, the combination (or product) of dose and monomer level shall not exceed that equivalent to an epichlorohydrin-based polymer containing 0.01% monomer dosed at 20 mg/L.
12 1,2-dibromoethane.
13 Carcinogenicity based on inhalation exposure.
14 Regulatory Determination Health Effects Support Document for Hexachlorobutadiene (PDF).
15 HMX = octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine.
16 Lindane = g - hexachlorocyclohexane.
17 MCPA = 4(chloro-2-methoxyphenoxy)acetic acid.
18 The Health Advisory Document for nitrocellulose does not include HA values and describes this compounds as relatively nontoxic.
19 RDX = hexahydro -1,3,5-trinitro-1,3,5-triazine.
Drinking Water Standards, Inrganics
| Chemicals | CASRN Number | Standards | Status HA Document | Health Advisories | Cancer Descriptor 1 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Status Reg. | MCLG (mg/L) | MCL (mg/L) | 10-kg Child | |||||||||
| One-day (mg/L) | Ten-day (mg/L) | RfD (mg/kg/day) | DWEL (mg/L) | Lifetime (mg/L) | mg/L at 10-4Cancer Risk | |||||||
| Ammonia | 7664-41-7 | — | — | — | D '92 | — | — | — | — | 30 | — | D |
| Antimony | 7440-36-0 | F | 0.006 | 0.006 | F '92 | 0.01 | 0.01 | 0.0004 | 0.01 | 0.006 | — | D |
| Arsenic | 7440-38-2 | F | zero | 0.01 | D '95 | — | — | 0.0003 | 0.01 | — | 0.002 | A |
| Asbestos (fibers/l >10µm length) | 1332-21-4 | F | 7 MFL1 | 7 MFL | — | — | — | — | — | — | 700-MFL | A2 |
| Barium | 7440-39-3 | F | 2 | 2 | D '93 | 0.7 | 0.7 | 0.2 | 7 | — | — | N |
| Beryllium | 7440-41-7 | F | 0.004 | 0.004 | F '92 | 30 | 30 | 0.002 | 0.07 | — | — | — |
| Boron | 7440-42-8 | — | — | — | D '92 | 4 | 0.9 | 0.2 | 7 | 1 | — | I |
| Bromate | 7789-38-0 | F | zero | 0.01 | D '98 | 0.2 | — | 0.004 | 0.14 | — | 0.005 | B2 |
| Cadmium | 7440-43-9 | F | 0.005 | 0.005 | F ’87 | 0.04 | 0.04 | 0.0005 | 0.02 | 0.005 | — | D |
| Chloramine3 | 10599-90-3 | F | 44 | 44 | D '95 | — | — | 0.1 | 3.5 | 3 | — | — |
| Chlorine | 7782-50-5 | F | 44 | 44 | D '95 | 3 | 3 | 0.1 | 5 | 4 | — | D |
| Chlorine dioxide | 10049-04-4 | F | 0.84 | 0.84 | D '98 | 0.84 | 0.84 | 0.03 | 1 | 0.8 | — | D |
| Chlorite | 7758-19-2 | F | 0.8 | 1 | D '98 | 0.84 | 0.84 | 0.03 | 1 | 0.8 | — | D |
| Chromium (total) | 7440-47-3 | F | 0.1 | 0.1 | F '87 | 1 | 1 | 0.0035 | 0.1 | — | — | D |
| Copper (at tap) | 7440-50-8 | F | 1.3 | TT6 | D '98 | — | — | — | — | — | — | D |
| Cyanide | 143-33-9 | F | 0.2 | 0.2 | F '87 | 0.2 | 0.2 | 0.027 | 0.8 | 0.2 | — | D |
| Fluoride | 7681-49-4 | F | 4 | 4 | — | — | — | 0.068 | — | — | — | — |
| Lead (at tap) | 7439-92-1 | F | zero | TT6 | — | — | — | — | — | — | — | B2 |
| Manganese | 7439-96-5 | — | — | — | F'04 | 1 | 1 | 0.149 | 1.6 | 0.3 | — | D |
| Mercury (inorganic) | 7487-94-7 | F | 0.002 | 0.002 | F '87 | 0.002 | 0.002 | 0.0003 | 0.01 | 0.002 | — | D |
| Molybdenum | 7439-98-7 | — | — | — | D '93 | 0.08 | 0.08 | 0.005 | 0.2 | 0.04 | — | D |
| Nickel | 7440-02-0 | F | — | — | F '95 | 1 | 1 | 0.02 | 0.7 | 0.1 | — | — |
| Nitrate (as N) | 14797-55-8 | F | 10 | 10 | D '93 | 1010 | 1010 | 1.6 | — | — | — | — |
| Nitrite (as N) | 14797-65-0 | F | 1 | 1 | D '93 | 110 | 110 | 0.16 | — | — | — | — |
| Nitrate + Nitrite (both as N) | F | 10 | 10 | D '93 | — | — | — | — | — | — | — | |
| Selenium | 7782-49-2 | F | 0.05 | 0.05 | — | — | — | 0.005 | 0.2 | 0.05 | — | D |
| Silver | 7440-22-4 | — | — | - | F '92 | 0.2 | 0.2 | 0.00511 | 0.2 | 0.1 | — | D |
| Strontium | 7440-24-6 | — | — | - | D '93 | 25 | 25 | 0.6 | 20 | 4 | — | D |
| Thallium | 7440-28-0 | F | 0.0005 | 0.002 | F '92 | 0.007 | 0.007 | 0.00007 | 0.002 | 0.0005 | — | — |
| White phosphorous | 7723-14-0 | — | — | - | F '90 | — | — | 0.00002 | 0.0005 | 0.0001 | D | |
| Zinc | 7440-66-6 | — | — | - | D '93 | 6 | 6 | 0.3 | 10 | 2 | — | I |
Footnotes, Inorganics
1 MFL = million fibers per liter.
2 Carcinogenicity based on inhalation exposure.
3 Monochloramine; measured as free chlorine.
4 1998 Final Rule for Disinfectants and Disinfection By-products: MRDLG=Maximum Residual Disinfection Level Goal; and MRDL=Maximum Residual Disinfection Level.
5 IRIS value for chromium VI.
6 Copper action level 1.3 mg/L; lead action level 0.015 mg/L.
7 This RfD is for hydrogen cyanide.
8 Based on dental fluorosis in children, a cosmetic effect. MCLG based on skeletal fluorosis.
9 Dietary manganese. The lifetime health advisory includes a 3 fold modifying factor to account for increased bioavailability from drinking water.
10 These values are calculated for a 4-kg infant and are protective for all age groups.
11 Based on a cosmetic effect.
Drinking Water Standards, Radionuclides
| Chemicals | CASRN Number | Standards | Status HA Document | Health Advisories | Cancer Descriptor 1 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Status Reg. | MCLG (mg/L) | MCL (mg/L) | 10-kg Child | |||||||||
| One-day (mg/L) | Ten-day (mg/L) | RfD (mg/kg/day) | DWEL (mg/L) | Lifetime (mg/L) | mg/L at 10-4Cancer Risk | |||||||
| Beta particle and photon activity (formerly man-made radionuclides) | F | zero | 4 mrem/yr | — | — | — | — | — | — | 4 mrem/yr | A | |
| Gross alpha particle activity | F | zero | 15 pCi/L | — | — | — | — | — | — | 15 pCi/L | A | |
| Combined Radium 226 & 228 | F | zero | 5 pCi/L | — | — | — | — | — | — | — | A | |
| Radon | P | zero | 300 pCi/L AMCL1 4000 pCi/L |
— | — | — | — | — | — | 150 pCi/L | A | |
| Uranium | 7440-61-1 | F | zero | 30 µg/L | — | — | — | 0.00062 | 0.02 | — | — | A |
Footnotes, Radionuclides
1 AMCL = Alternative Maximum Contaminant Level.
2 Soluble uranium salts. Radionuclide Rule.
Secondary Drinking Water Regulations
| Chemicals | CAS Number | Status | SDWR |
|---|---|---|---|
| Aluminum | 7429-90-5 | F | 0.05 to 0.2 mg/L |
| Chloride | 7647-14-5 | F | 250 mg/L |
| Color | NA | F | 15 color units |
| Copper | 7440-50-8 | F | 1.0 mg/L |
| Corrosivity | NA | F | non-corrosive |
| Fluoride | 7681-49-4 | F | 2.0 mg/L |
| Foaming agents | NA | F | 0.5 mg/L |
| Iron | 7439-89-6 | F | 0.3 mg/L |
| Manganese | 7439-96-5 | F | 0.05 mg/L |
| Odor | NA | F | 3 threshold odor numbers |
| pH | NA | F | 6.5 – 8.5 |
| Silver | 7440-22-4 | F | 0.1 mg/L |
| Sulfate | 7757-82-6 | F | 250 mg/L |
| Total dissolved solids (TDS) | NA | F | 500 mg/L |
| Zinc | 7440-66-6 | F | 5 mg/L |
Microbiology
| Status Reg. | Status HA Document | MCLG | MCL | Treatment Technique | |
|---|---|---|---|---|---|
| Cryptosporidium | F | F 01 | — | TT | Systems that filter must remove 99% of Cryptosporidium |
| Giardia lamblia | F | F 98 | — | TT | 99.9% killed/inactivated |
| Legionella | F1 | F 01 | zero | TT | No limit; EPA believes that if Giardia and viruses are inactivated, Legionella will also be controlled |
| Heterotrophic Plate Count (HPC) | F1 | — | NA | TT | No more than 500 bacterial colonies per milliliter. |
| Mycobacteria | — | F 99 | — | — | — |
| Total Coliforms | F | — | zero | 5% | No more than 5.0% samples total coliform-positive in a month. Every sample that has total coliforms must be analyzed for fecal coliforms; no fecal coliforms are allowed. |
| Turbidity | F | — | NA | TT | At no time can turbidity go above 5 NTU (nephelometric turbidity units) |
| Viruses | F1 | — | zero | TT | 99.99% killed/inactivated |
Footnotes, Microbiology
1 - Final for systems using surface water; also being considered for regulation under groundwater disinfection rule.
Drinking Water Advisory Table
| Summer 2006 | ||||
| Chemicals | Status | Heath-based Value | Taste Threshold 1 | Odor Threshold 2 |
|---|---|---|---|---|
| Ammonia | D '92 | Not Available | 30 mg/L | |
| Methyl tertiary butyl ether (MtBE) | F '98 | Not Available | 40 µg/L | 20 µg/L |
| Sodium | F '03 | 20 mg/L (for individuals on a 500 mg/day restricted sodium diet). | 30–60 mg/L | |
| Sulfate | F '03 | 500 mg/L | 250 mg/L | |
Footnotes, Advisory
1 Taste Threshold: Concentration at which the majority of consumers do not notice an adverse taste in drinking water; it is recognized that some sensitive individuals may detect a chemical at levels below this threshold.
2 Odor Threshold: Concentration at which the majority of consumers do not notice an adverse odor in drinking water; it is recognized that some sensitive individuals may detect a chemical at levels below this threshold.