2006 Edition of the Drinking

Water Standards and Health

Advisories
2006 Edition of the Drinking Water

Standards and Health Advisories

EPA 822-R-06-013

Office of Water

U.S. Environmental Protection Agency

Washington, DC

Summer 2006

Date of update: August, 2006

Recycled/Recyclable

Printed on paper that contains

at least 50% recycled fiber.
(i)

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.

The IRIS Toxicological Reviews can be accessed at: http://www.epa.gov/IRIS. The OPP

REDs can be accessed at: http://cfpub.epa.gov/oppref/rereg/status.cfm?show=rereg

 

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.

The Drinking Water Standards and Health Advisories Tables may be reached from the Water

Science home page at: http://www.epa.gov/waterscience. The Tables are accessed under the

Health Advisories heading.

Copies the 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
(ii)

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
(iii)

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. 
(iv)

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 Office of Pesticide Programs

P Proposed

Reg Regulation

TT Treatment Technique
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals

CASRN

Number

Standards

Status

HA

Document

Health Advisories

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)

L

t

(m

ORGANICSAcenaphthene 83-32-9 - - - - - - 0.06 2 Acifluorfen (sodium) 62476-59-9 - - F ’88 2 2 0.01 0.4 Acrylamide 79-06-1 F zero TT2 F ‘87 1.5 0.3 0.0002 0.007 

Acrylonitrile 107-13-1 - - - - - - - Alachlor 15972-60-8 F zero 0.002 F ‘88 0.1 0.1 0.01 0.4 Aldicarb3 116-06-3 F4 0.001 0.003 F ‘95 0.01 0.01 0.001 0.035 

Aldicarb sulfone3 1646-88-4 F4 0.001 0.002 F ‘95 0.01 0.01 0.001 0.035 Aldicarb sulfoxide3 1646-87-3 F4 0.001 0.004 F ‘95 0.01 0.01 0.001 0.035 Aldrin 309-00-2 - - - F ‘92 0.0003 0.0003 0.00003 0.001 Ametryn 834-12-8 - - - F ‘88 9 9 0.009 0.3 Ammonium sulfamate 7773-06-0 - - - F ‘88 20 20 0.2 8 Anthracene (PAH) 5 120-12-7 - - - - - - 0.3 10 

Atrazine 1912-24-9 F 0.003 0.003 F ‘88 - - 0.02 0.7 

Baygon 114-26-1 - - - F ‘88 0.04 0.04 0.004 0.1 Bentazon 25057-89-0 - - - F ‘99 0.3 0.3 0.03 1 Benz[a]anthracene (PAH) 56-55-3 - - - - - - - - Benzene 71-43-2 F zero 0.005 F ’87 0.2 0.2 0.004 0.1 

Benzo[a]pyrene (PAH) 50-32-8 F zero 0.0002 - - - - - Benzo[b]fluoranthene (PAH) 205-99-2 - - - - - - - - Benzo[g,h,i]perylene (PAH) 191-24-2 - - - - - - - - Benzo[k]fluoranthene (PAH) 207-08-9 - - - - - - - - bis-2-Chloroisopropyl ether 39638-32-9 - - - F ‘89 4 4 0.04 1 Bromacil 314-40-9 - - - F ‘88 5 5 0.1 3.5 

Bromobenzene 108-86-1 - - - D ‘86 4 4 - - 

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 

has not completed a new assessment for the chemical, the 1986 Guidelines Group designation (see page iii) 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 polyacrylam

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.
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals

CASRN

Number

Standards

Status

HA

Document

Health Advisories

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)

Lif

(m

Bromochloromethane 74-97-5 - - - F ‘89 50 1 0.01 0.5 Bromodichloromethane(THM)

75-27-4 F zero 0.081 - 1 0.6 0.003 0.1 

Bromoform (THM) 75-25-2 F zero 0.081 - 5 0.2 0.03 1 Bromomethane 74-83-9 - - - D ‘89 0.1 0.1 0.001 0.05 Butyl benzyl phthalate 85-68-7 - - - - - - 0.2 7 Butylate 2008-41-5 - - - F ‘89 2 2 0.05 2 Carbaryl 63-25-2 - - - F ‘88 1 1 0.01 0.4 

Carbofuran 1563-66-2 F 0.04 0.04 F ‘87 - - 0.00006 -

Carbon tetrachloride 56-23-5 F zero 0.005 F ‘87 4 0.2 0.0007 0.03 Carboxin 5234-68-4 - - - F ‘88 1 1 0.1 3.5 Chloramben 133-90-4 - - - F ‘88 3 3 0.015 0.5 Chlordane 57-74-9 F zero 0.002 F ‘87 0.06 0.06 0.0005 0.02 

Chloroform (THM) 67-66-3 F 0.07 0.081 -4 4 0.01 0.35 

Chloromethane 74-87-3 - - - F ‘89 9 0.4 0.004 0.1 Chlorophenol (2-) 95-57-8 - - - D ‘94 0.5 0.5 0.005 0.2 Chlorothalonil 1897-45-6 - - - F ‘88 0.2 0.2 0.015 0.5 Chlorotoluene o- 95-49-8 - - - F ‘89 2 2 0.02 0.7 Chlorotoluene p- 106-43-4 - - - F ‘89 2 2 0.02 0.7 Chlorpyrifos 2921-88-2 - - - F ‘92 0.03 0.03 0.0003 0.01 

Chrysene (PAH) 218-01-9 - - - - - - - - Cyanazine 21725-46-2 - - - D ‘96 0.1 0.1 0.002 0.07 

1 1998 Final Rule for Disinfectants and Disinfection By-products: The total for trihalomethanes (THM) is 0.08 mg/L.
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals

CASRN

Number

Standards

Status

HA

Document

Health Advisories

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)

Lif

(m

Cyanogen chloride1 506-77-4 - - - - 0.05 0.05 0.05 2 

2,4-D (2,4-dichlorophenoxyacetic acid)

94-75-7 F 0.07 0.07 F ‘87 1 0.3 0.005 0.2 

DCPA (Dacthal) 1861-32-1 - - - F ‘88 80 80 0.01 0.35 

Dalapon (sodium salt) 75-99-0 F 0.2 0.2 F ‘89 3 3 0.03 0.9 Di(2-ethylhexyl)adipate 103-23-1 F 0.4 0.4 - 20 20 0.6 20 Di(2-ethylhexyl)phthalate 117-81-7 F zero 0.006 - - - 0.02 0.7 Diazinon 333-41-5 - - - F ‘88 0.02 0.02 0.0002 0.007 

Dibromochloromethane (THM) 124-48-1 F 0.06 0.082 - 0.6 0.6 0.02 0.7 

Dibromochloropropane (DBCP) 96-12-8 F zero 0.0002 F ’87 0.2 0.05 - - Dibutyl phthalate 84-74-2 - - - - - - 0.1 4 Dicamba 1918-00-9 - - - F ‘88 - - 0.5 18 

Dichloroacetic acid 76-43-6 F zero 0.063 -5 5 0.004 0.1 

Dichlorobenzene o- 95-50-1 F 0.6 0.6 F ‘87 9 9 0.09 3 Dichlorobenzene — 4 541-73-1 - - - F ‘87 9 9 0.09 3 

Dichlorobenzene p- 106-46-7 F 0.075 0.075 F ‘87 11 11 0.1 4 Dichlorodifluoromethane 75-71-8 - - - F ’89 40 40 0.2 5 Dichloroethane (1,2-) 107-06-2 F zero 0.005 F ‘87 0.7 0.7 - - Dichloroethylene (1,1-) 75-35-4 F 0.007 0.007 F ‘87 2 1 0.05 2 

Dichloroethylene (cis-1,2-) 156-59-2 F 0.07 0.07 F ‘90 4 1 0.01 0.35 Dichloroethylene (trans-1,2-) 156-60-5 F 0.1 0.1 F ‘87 20 1 0.02 0.7 

Dichloromethane 75-09-2 F zero 0.005 D ‘93 10 2 0.06 2 Dichlorophenol (2,4-) 120-83-2 - - - D ‘94 0.03 0.03 0.003 0.1 Dichloropropane (1,2-) 78-87-5 F zero 0.005 F ’87 - 0.09 - - Dichloropropene (1,3-) 542-75-6 - - - F ‘88 0.03 0.03 0.03 1 

Dieldrin 60-57-1 - - - F ‘88 0.0005 0.0005 0.00005 0.002 Diethyl phthalate 84-66-2 - - - - - - 0.8 30 

1 Under review. 2 1998 Final Rule for Disinfectants and Disinfection By-products: The total for trihalomethanes is 0.08 mg/L. 3 1998 Final Rule for Disinfectants and Disinfection By-products: The total for five haloacetic acids is 0.06 mg/L. 4 The values for m-dichlorobenzene are based on data for o-dichlorobenzene. 
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals

CASRN

Number

Standards

Status

HA

Document

Health Advisories

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)

Lif

(m

Diisopropylmethylphosphonate

1445-75-6 - - - F ‘89 8 8 0.08 3 

Dimethrin 70-38-2 - - - F ‘88 10 10 0.3 10 Dimethyl methylphosphonate 756-79-6 - - - F ‘92 2 2 0.2 7 Dimethyl phthalate 131-11-3 - - - - - - - - Dinitrobenzene (1,3-) 99-65-0 - - - F ‘91 0.04 0.04 0.0001 0.005 Dinitrotoluene (2,4-) 121-14-2 - - - F ‘92 0.50 0.50 0.002 0.1 Dinitrotoluene (2,6-) 606-20-2 - - - F ‘92 0.40 0.40 0.001 0.04 Dinitrotoluene (2,6 & 2,4) 1 - - - F ‘92 - - - - 

Dinoseb 88-85-7 F 0.007 0.007 F ‘88 0.3 0.3 0.001 0.035 Dioxane p- 123-91-1 - - - F ‘87 4 0.4 - - Diphenamid 957-51-7 - - - F ‘88 0.3 0.3 0.03 1 Diquat 85-00-7 F 0.02 0.02 - - - 0.005 0.02 

Disulfoton 298-04-4 - - - F ‘88 0.01 0.01 0.0001 0.0035 

Dithiane (1,4-) 505-29-3 - - - F ‘92 0.4 0.4 0.01 0.4 Diuron 330-54-1 - - - F ‘88 1 1 0.003 0.1 

Endothall 145-73-3 F 0.1 0.1 F ‘88 0.8 0.8 0.007 0.25 

Endrin 72-20-8 F 0.002 0.002 F ‘87 0.02 0.005 0.0003 0.01 Epichlorohydrin 106-89-8 F zero TT2 F ‘87 0.1 0.1 0.002 0.07 

Ethylbenzene 100-41-4 F 0.7 0.7 F ‘87 30 3 0.1 3 Ethylene dibromide (EDB)3 106-93-4 F zero 0.00005 F ‘87 0.008 0.008 0.009 0.3 

Ethylene glycol 107-21-1 - - - F ‘87 20 6 2 70 1

Ethylene Thiourea (ETU) 96-45-7 - - - F ‘88 0.3 0.3 0.00008 0.003 

Fenamiphos 22224-92-6 - - - F ‘88 0.009 0.009 0.0001 0.0035 

1 Technical grade. 2 When epichlorohydrin is used in drinking water systems, the combination (or product) of dose and monomer level shall not exceed that equivalent to an epich

containing 0.01% monomer dosed at 20 mg/L. 3 1,2-dibromoethane. 
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals CAS Number

Standards

Status

HA

Standards

Health Advisories

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)

Lif

(m

Fluometuron 2164-17-2 - - - F ‘88 2 2 0.01 0.5 Fluorene (PAH) 86-73-7 - - - - - - 0.04 1 Fonofos 944-22-9 - - - F ‘88 0.02 0.02 0.002 0.07 Formaldehyde 50-00-0 - - - D ‘93 10 5 0.2 7 

Glyphosate 1071-83-6 F 0.7 0.7 F ‘88 20 20 2 70 

Heptachlor 76-44-8 F zero 0.0004 F ‘87 0.01 0.01 0.0005 0.02 Heptachlor epoxide 1024-57-3 F zero 0.0002 F ‘87 0.01 - 0.00001 0.0004 Hexachlorobenzene 118-74-1 F zero 0.001 F ‘87 0.05 0.05 0.0008 0.03 Hexachlorobutadiene2 87-68-3 - - - - 0.3 0.3 0.0003 0.01 

Hexachlorocyclopentadiene 77-47-4 F 0.05 0.05 - - - 0.006 0.2 

Hexachloroethane 67-72-1 - - - F ‘91 5 5 0.001 0.04 Hexane (n-) 110-54-3 - - - F ‘87 10 4 - - Hexazinone 51235-04-2 - - - F ‘96 3 2 0.05 2 HMX3 2691-41-0 - - - F ‘88 5 5 0.05 2 

Indeno[1,2,3,-c,d]pyrene(PAH)

193-39-5 - - - - - - - - 

Isophorone 78-59-1 - - - F ‘92 15 15 0.2 7 Isopropyl methylphosphonate 1832-54-8 - - - F ‘92 30 30 0.1 3.5 Isopropylbenzene (cumene) 98-82-8 - - - D ‘87 11 11 0.1 4 Lindane 4 58-89-9 F 0.0002 0.0002 F ‘87 1 1 0.005 0.2 

Malathion 121-75-5 - - - F ‘92 0.2 0.2 0.02 0.8 Maleic hydrazide 123-33-1 - - - F ‘88 10 10 0.5 20 MCPA 5 94-74-6 - - - F ‘88 0.1 0.1 0.004 0.14 Methomyl 16752-77-5 - - - F ‘88 0.3 0.3 0.025 0.9 Methoxychlor 72-43-5 F 0.04 0.04 F ‘87 0.05 0.05 0.005 0.2 Methyl ethyl ketone 78-93-3 - - - F ‘87 75 7.5 0.6 20 Methyl parathion 298-00-0 - - - F ‘88 0.3 0.3 0.0002 0.007 

1 Carcinogenicity based on inhalation exposure. 2 Regulatory Determination Health Effects Support Document for Hexachlorobutadiene

(http://www.epa.gov/safewater/ccl/pdfs/reg_determine1/support_cc1_hexachlorobutadiene_healtheffects.pdf). 3 HMX = octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine. 4 Lindane = γ − hexachlorocyclohexane. 5 MCPA = 4(chloro-2-methoxyphenoxy)acetic acid.
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals

CASRN

Number

Standards

Status

HA

Document

Health Advisories

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)

Lif

(m

Metolachlor 51218-45-2 - - - F ‘88 2 2 0.1 3.5 

Metribuzin 21087-64-9 - - - F ‘88 5 5 0.01 0.35 

Monochloroacetic acid 79-11-8 F 0.03 0.061 - 0.2 0.2 0.01 0.35 

Monochlorobenzene 108-90-7 F 0.1 0.1 F ‘87 4 4 0.02 0.7 

Naphthalene 91-20-3 - - - F ‘90 0.5 0.5 0.02 0.7 

Nitrocellulose2 9004-70-0 - - - F ‘88 - - - - 

Nitroguanidine 556-88-7 - - - F ‘90 10 10 0.1 3.5 Nitrophenol p- 100-02-7 - - - F ‘92 0.8 0.8 0.008 0.3 Oxamyl (Vydate) 23135-22-0 F 0.2 0.2 F ‘05 0.01 0.01 0.001 0.035 Paraquat 1910-42-5 - - - F ‘88 0.1 0.1 0.0045 0.2 

Pentachlorophenol 87-86-5 F zero 0.001 F ‘87 1 0.3 0.03 1 Phenanthrene (PAH) 85-01-8 - - - - - - - - 

Phenol 108-95-2 - - - D ‘92 6 6 0.3 11 

Picloram 1918-02-1 F 0.5 0.5 F ‘88 20 20 0.02 0.7 

Polychlorinated biphenyls(PCBs)

1336-36-3 F zero 0.0005 D ‘93 - - - - 

Prometon 1610-18-0 - - - F ‘88 0.2 0.2 0.015 0.5 Pronamide 23950-58-5 - - - F ‘88 0.8 0.8 0.08 3 

Propachlor 1918-16-7 - - - F ‘88 0.5 0.5 0.05 2 

Propazine 139-40-2 - - - F ‘88 - - 0.02 0.7 

Propham 122-42-9 - - - F ‘88 5 5 0.02 0.6 Pyrene (PAH) 129-00-0 - - - - - - 0.03 - RDX3 121-82-4 - - - F ‘88 0.1 0.1 0.003 0.1 

Simazine 122-34-9 F 0.004 0.004 F ‘88 - - 0.02 0.7 

Styrene 100-42-5 F 0.1 0.1 F ‘87 20 2 0.2 7 2,4,5-T (Trichlorophenoxyacetic acid) 93-76-5 - - - F ‘88 0.8 0.8 0.01 0.35 

1 1998 Final Rule for Disinfectants and Disinfection By-products: the total for five haloacetic acids is 0.06mg/L. 2 The Health Advisory Document for nitrocellulose does not include HA values and describes this compounds as relatively nontoxic. 3 RDX = hexahydro -1,3,5-trinitro-1,3,5-triazine.
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals

CASRN

Number

Standards

Status

HA

Document

Health Advisories

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)

L

(

2,3,7,8-TCDD (Dioxin) 1746-01-6 F zero 3E-08 F ’87 1E-06 1E-07 1E-09 4E-08 Tebuthiuron 34014-18-1 - - - F ‘88 3 3 0.07 2 Terbacil 5902-51-2 - - - F ‘88 0.3 0.3 0.01 0.4 Terbufos 13071-79-9 - - - F ‘88 0.005 0.005 0.00005 0.002 Tetrachloroethane (1,1,1,2-) 630-20-6 - - - F ‘89 2 2 0.03 1 Tetrachloroethane (1,1,2,2-) 79-34-5 - - - F ‘89 0.04 0.04 0.00005 0.002 Tetrachloroethylene1 127-18-4 F zero 0.005 F ‘87 2 2 0.01 0.5 

Trichlorofluoromethane 75-69-4 - - - F ‘89 7 7 0.3 10 Toluene 108-88-3 F 1 1 D ‘93 20 2 0.08 3Toxaphene 8001-35-2 F zero 0.003 F ‘96 0.004 0.004 0.0004 0.01 2,4,5-TP (Silvex) 93-72-1 F 0.05 0.05 F ‘88 0.2 0.2 0.008 0.3 Trichloroacetic acid 76-03-9 F 0.02 0.062 - 3 3 0.03 1 

Trichlorobenzene (1,2,4-) 120-82-1 F 0.07 0.07 F ‘89 0.1 0.1 0.01 0.35 Trichlorobenzene (1,3,5-) 108-70-3 - - - F ‘89 0.6 0.6 0.006 0.2 Trichloroethane (1,1,1-) 71-55-6 F 0.2 0.2 F ‘87 100 40 0.035 1 Trichloroethane (1,1,2-) 79-00-5 F 0.003 0.005 F ‘89 0.6 0.4 0.004 0.1 Trichloroethylene 1 79-01-6 F zero 0.005 F ‘87 - - 0.007 0.2 

Trichlorophenol (2,4,6-) 88-06-2 - - - D ‘94 0.03 0.03 0.0003 0.01 Trichloropropane (1,2,3-) 96-18-4 - - - F ‘89 0.6 0.6 0.006 0.2 Trifluralin 1582-09-8 - - - F ‘90 0.08 0.08 0.02 0.7 

Trimethylbenzene (1,2,4-) 95-63-6 - - - D ‘87 - - - - Trimethylbenzene (1,3,5-) 108-67-8 - - - D ‘87 10 - - - Trinitroglycerol 55-63-0 - - - F ‘87 0.005 0.005 - - Trinitrotoluene (2,4,6-) 118-96-7 - - - F ‘89 0.02 0.02 0.0005 0.02 Vinyl chloride 75-01-4 F zero 0.002 F ‘87 3 3 0.003 0.1 

Xylenes 1330-20-7 F 10 10 D ‘93 40 40 0.2 7

1 Under review. 2 1998 Final Rule for Disinfectants and Disinfection By-products: The total for five haloacetic acids is 0.06 mg/L.
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals

CASRN

Number

Standards

Status

HA

Document

Health Advisories

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)

L

(

INORGANICSAmmonia 7664-41-7 - - - D ‘92 - - - - Antimony 7440-36-0 F 0.006 0.006 F ‘92 0.01 0.01 0.0004 0.01 Arsenic 7440-38-2 F zero 0.01 D ‘95 - - 0.0003 0.01 

Asbestos (fibers/l >10μmlength)

1332-21-4 F 7 MFL1 7 MFL - - - - - 

Barium 7440-39-3 F 2 2 D ‘93 0.7 0.7 0.2 7

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

Bromate 7789-38-0 F zero 0.01 D ‘98 0.2 - 0.004 0.14 Cadmium 7440-43-9 F 0.005 0.005 F ’87 0.04 0.04 0.0005 0.02 Chloramine3 10599-90-3 F 44 44 D ‘95 - - 0.1 3.5 

Chlorine 7782-50-5 F 44 44 D ‘95 3 3 0.1 5 Chlorine dioxide 10049-04-4 F 0.84 0.84 D ‘98 0.84 0.84 0.03 1 Chlorite 7758-19-2 F 0.8 1 D ‘98 0.84 0.84 0.03 1 Chromium (total) 7440-47-3 F 0.1 0.1 F ‘87 1 1 0.0035 0.1 

Copper (at tap) 7440-50-8 F 1.3 TT6 D ‘98 - - - - 

Cyanide 143-33-9 F 0.2 0.2 F ‘87 0.2 0.2 0.027 0.8 

Fluoride 7681-49-4 F 4 4 - - - 0.068 -

Lead (at tap) 7439-92-1 F zero TT6 - - - - - 

Manganese 7439-96-5 - - - F”04 1 1 0.149 1.6 

Mercury (inorganic) 7487-94-7 F 0.002 0.002 F ‘87 0.002 0.002 0.0003 0.01 

Molybdenum 7439-98-7 - - - D ‘93 0.08 0.08 0.005 0.2 Nickel 7440-02-0 F - - F ‘95 1 1 0.02 0.7 

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 Disi5 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.
Drinking Water Standards and Health Advisories

Summer 2006 

Chemicals

CASRN

Number

Standards

Status

HA

Document

Health Advisories

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)

(

Nitrate (as N) 14797-55-8 F 10 10 D ‘93 101 101 1.6 - 

Nitrite (as N) 14797-65-0 F 1 1 D ‘93 11 11 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 Silver 7440-22-4 - - - F ‘92 0.2 0.2 0.0052 0.2 

Strontium 7440-24-6 - - - D ‘93 25 25 0.6 20 

Thallium 7440-28-0 F 0.0005 0.002 F ‘92 0.007 0.007 0.00007 0.002 

White phosphorous 7723-14-0 - - - F ‘90 - - 0.00002 0.0005 Zinc 7440-66-6 - - - D ‘93 6 6 0.3 10 RADIONUCLIDESBeta particle and photon activity (formerly man-made radionuclides) F zero

4 mrem/

yr - - - - - 

Gross alpha particle activity F zero 15

pCi/L

- - - - - 

Combined Radium 226 & 228 7440-14-4 F zero 5 pCi/L - - - - - Radon 10043-92-2 P zero 300

pCi/L

AMCL3

4000

pCi/L

- - - - - 

Uranium 7440-61-1 F zero 30 μg/L - - - 0.00064 0.02 

1 These values are calculated for a 4-kg infant and are protective for all age groups. 2 Based on a cosmetic effect. 3 AMCL = Alternative Maximum Contaminant Level 4 Soluble uranium salts. Radionuclide Rule.
Secondary Drinking Water Regulations

Summer 2006 

Chemicals CAS Number Status SDWR

Aluminum 7429-90-5 F 0.05 to 0.2 Chloride 7647-14-5 F 250 mgColor NA F 15 color uCopper 7440-50-8 F 1.0 mg/Corrosivity NA F non-corroFluoride 7681-49-4 F 2.0 mg/Foaming agents NA F 0.5 mg/Iron 7439-89-6 F 0.3 mg/Manganese 7439-96-5 F 0.05 mgOdor NA F 3 threshold odopH NA F 6.5 – 8.Silver 7440-22-4 F 0.1 mg/Sulfate 7757-82-6 F 250 mgTotal dissolved solids (TDS) NA F 500 mgZinc 7440-66-6 F 5 mg/L
Microbiology

Summer 2006 

Status

Reg.

Status HA

Document

MCLG MCL Treatment Tec

Cryptosporidium F F 01 - TT Systems that filter mu

99% of Cryptosporidi

Giardia lamblia F F 98 - TT 99.9% killed/inactivatLegionella F1 F 01 zero TT No limit; EPA believe

Giardia and viruses aLegionella will also be 

Heterotrophic Plate Count(HPC)

F1 - NA TT No more than 500 ba

colonies per milliliter.

Mycobacteria - F 99 - - -Total Coliforms F - zero 5% No more than 5.0% s

coliform-positive in a sample that has total must be analyzed for coliforms; no fecal coallowed.

Turbidity F - NA TT At no time can turbidi

NTU (nephelometric t

Viruses F1 - zero TT 99.99% killed/inactiva

1 Final for systems using surface water; also being considered for regulation under groundwater disinfection rule.
Drinking Water Advisory Table

Summer 2006 

Chemicals Status Health-based Value Taste

Threshold

OdorThresho

Ammonia D ‘92 Not Available 30 mg/LMethyl tertiary butylether (MtBE)

F ‘98 Not Available 40 

μg/L 20 

μg/L

Sodium F ‘03 20 mg/L (for

individuals on a 500mg/day restrictedsodium diet).

30-60 mg/L

Sulfate F ‘03 500 mg/L 250 mg/L

Taste Threshold: Concentration at which the majority of consumers do not notice an adverse taste in drinking waterrecognized that some sensitive individuals may detect a chemical at levels below this threshold.Odor Threshold: Concentration at which the majority of consumers do not notice an adverse odor in drinking water; 

that some sensitive individuals may detect a chemical at levels below this threshold.