[Code of Federal Regulations]

[Title 40, Volume 22]

[Revised as of July 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 40CFR141.32]



[Page 392-414]

 

                   TITLE 40--PROTECTION OF ENVIRONMENT

 

         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

 

PART 141_NATIONAL PRIMARY DRINKING WATER REGULATIONS--Table of Contents

 

                  Subpart D_Reporting and Recordkeeping

 

Sec. 141.32  Public notification.



    The requirements in this section apply until the requirements of 

Subpart Q of this part are applicable. Public water systems where EPA 

directly implements the public water system supervision program must 

comply with the requirements in Subpart Q of this part on October 31, 

2000. All other public water systems must comply with the requirements 

in Subpart Q of this part on May 6, 2002 or on the date the State-

adopted rule becomes effective, whichever comes first.

    (a) Maximum contaminant levels (MCLs), maximum residual disinfectant 

levels (MRDLs). The owner or operator of a public water system which 

fails to comply with an applicable MCL or treatment technique 

established by this part or which fails to comply with the requirements 

of any schedule prescribed pursuant to a variance or exemption, shall 

notify persons served by the system as follows:

    (1) Except as provided in paragraph (a)(3) of this section, the 

owner or operator of a public water system must give notice:

    (i) By publication in a daily newspaper of general circulation in 

the area served by the system as soon as possible, but in no case later 

than 14 days after the violation or failure. If the area served by a 

public water system is not served by a daily newspaper of general 

circulation, notice shall instead be given by publication in a weekly 

newspaper of general circulation serving the area; and

    (ii) By mail delivery (by direct mail or with the water bill), or by 

hand delivery, not later than 45 days after the violation or failure. 

The State may waive mail or hand delivery if it determines that the 

owner or operator of the public water system in violation has corrected 

the violation or failure within the 45-day period. The State must make 

the waiver in writing and within the 45-day period; and

    (iii) For violations of the MCLs of contaminants or MRDLs of 

disinfectants that may pose an acute risk to human health, by furnishing 

a copy of the notice to the radio and television stations serving the 

area served by the public water system as soon as possible but in no 

case later than 72 hours after the violation. The following violations 

are acute violations:

    (A) Any violations specified by the State as posing an acute risk to 

human health.

    (B) Violation of the MCL for nitrate or nitrite as defined in Sec. 

141.62 and determined according to Sec. 141.23(i)(3).

    (C) Violation of the MCL for total coliforms, when fecal coliforms 

or E. coli are present in the water distribution system, as specified in 

Sec. 141.63(b).

    (D) Occurrence of a waterborne disease outbreak, as defined in Sec. 

141.2, in



[[Page 393]]



an unfiltered system subject to the requirements of subpart H of this 

part, after December 30, 1991 (see Sec. 141.71(b)(4)).

    (E) Violation of the MRDL for chlorine dioxide as defined in Sec. 

141.65 and determined according to Sec. 141.133(c)(2).

    (2) Except as provided in paragraph (a)(3) of this section, 

following the initial notice given under paragraph (a)(1) of this 

section, the owner or operator of the public water system must give 

notice at least once every three months by mail delivery (by direct mail 

or with the water bill) or by hand delivery, for as long as the 

violation or failure exists.

    (3)(i) In lieu of the requirements of paragraphs (a) (1) and (2) of 

this section, the owner or operator of a community water system in an 

area that is not served by a daily or weekly newspaper of general 

circulation must give notice by hand delivery or by continuous posting 

in conspicuous places within the area served by the system. Notice by 

hand delivery or posting must begin as soon as possible, but no later 

than 72 hours after the violation or failure for acute violations (as 

defined in paragraph (a)(1)(iii) of this section), or 14 days after the 

violation or failure (for any other violation). Posting must continue 

for as long as the violation or failure exists. Notice by hand delivery 

must be repeated at least every three months for as long as the 

violation or failure exists.

    (ii) In lieu of the requirements of paragraphs (a) (1) and (2) of 

this section, the owner or operator of a non-community water system may 

give notice by hand delivery or by continuous posting in conspicuous 

places within the area served by the system. Notice by hand delivery or 

posting must begin as soon as possible, but no later than 72 hours after 

the violation or failure for acute violations (as defined in paragraph 

(a)(1)(iii) of this section), or 14 days after the violation or failure 

(for any other violation). Posting must continue for as long as the 

violation or failure exists. Notice by hand delivery must be repeated at 

least every three months for as long as the violation or failure exists.

    (b) Other violations, variances, exemptions. The owner or operator 

of a public water system which fails to perform monitoring required by 

section 1445(a) of the Act (including monitoring required by the 

National Primary Drinking Water Regulations (NPDWRs) of this part), 

fails to comply with a testing procedure established by this part, is 

subject to a variance granted under section 1415(a)(1)(A) or 1415(a)(2) 

of the Act, or is subject to an exemption under section 1416 of the Act, 

shall notify persons served by the system as follows:

    (1) Except as provided in paragraph (b)(3) or (b)(4) of this 

section, the owner or operator of a public water system must give notice 

within three months of the violation or granting of a variance or 

exemption by publication in a daily newspaper of general circulation in 

the area served by the system. If the area served by a public water 

system is not served by a daily newspaper of general circulation, notice 

shall instead be given by publication in a weekly newspaper of general 

circulation serving the area.

    (2) Except as provided in paragraph (b)(3) or (b)(4) of this 

section, following the initial notice given under paragraph (b)(1) of 

this section, the owner or operator of the public water system must give 

notice at least once every three months by mail delivery (by direct mail 

or with the water bill) or by hand delivery, for as long as the 

violation exists. Repeat notice of the existence of a variance or 

exemption must be given every three months for as long as the variance 

or exemption remains in effect.

    (3)(i) In lieu of the requirements of paragraphs (b)(1) and (b)(2) 

of this section, the owner or operator of a community water system in an 

area that is not served by a daily or weekly newspaper of general 

circulation must give notice, within three months of the violation or 

granting of the variance or exemption, by hand delivery or by continuous 

posting in conspicuous places with the area served by the system. 

Posting must continue for as long as the violation exists or a variance 

or exemption remains in effect. Notice by hand delivery must be repeated 

at least every three months for as long as the violation exists or a 

variance or exemption remains in effect.



[[Page 394]]



    (ii) In lieu of the requirements of paragraphs (b)(1) and (b)(2) of 

this section, the owner or operator of a non-community water system may 

give notice, within three months of the violation or the granting of the 

variance or exemption, by hand delivery or by continuous posting in 

conspicuous places within the area served by the system. Posting must 

continue for as long as the violation exists, or a variance or exemption 

remains in effect. Notice by hand delivery must be repeated at least 

every three months for as long as the violation exists or a variance or 

exemption remains in effect.

    (4) In lieu of the requirements of paragraphs (b)(1), (b)(2), and 

(b)(3) of this section, the owner or operator of a public water system, 

at the discretion of the State, may provide less frequent notice for 

minor monitoring violations as defined by the State, if EPA has approved 

the State's application for a program revision under Sec. 142.16. 

Notice of such violations must be given no less frequently than 

annually.

    (c) Notice to new billing units. The owner or operator of a 

community water system must give a copy of the most recent public notice 

for any outstanding violation of any maximum contaminant level, or any 

maximum residual disinfectant level, or any treatment technique 

requirement, or any variance or exemption schedule to all new billing 

units or new hookups prior to or at the time service begins.

    (d) General content of public notice. Each notice required by this 

section must provide a clear and readily understandable explanation of 

the violation, any potential adverse health effects, the population at 

risk, the steps that the public water system is taking to correct such 

violation, the necessity for seeking alternative water supplies, if any, 

and any preventive measures the consumer should take until the violation 

is corrected. Each notice shall be conspicuous and shall not contain 

unduly technical language, unduly small print, or similar problems that 

frustrate the purpose of the notice. Each notice shall include the 

telephone number of the owner, operator, or designee of the public water 

system as a source of additional information concerning the notice. 

Where appropriate, the notice shall be multi-lingual.

    (e) Mandatory health effects language. When providing the 

information on potential adverse health effects required by paragraph 

(d) of this section in notices of violations of maximum contaminant 

levels or treatment technique requirements, or notices of the granting 

or the continued existence of exemptions or variances, or notices of 

failure to comply with a variance or exemption schedule, the owner or 

operator of a public water system shall include the language specified 

below for each contaminant. (If language for a particular contaminant is 

not specified below at the time notice is required, this paragraph does 

not apply.)

    (1) Trichloroethylene. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

trichloroethylene is a health concern at certain levels of exposure. 

This chemical is a common metal cleaning and dry cleaning fluid. It 

generally gets into drinking water by improper waste disposal. This 

chemical has been shown to cause cancer in laboratory animals such as 

rats and mice when the animals are exposed at high levels over their 

lifetimes. Chemicals that cause cancer in laboratory animals also may 

increase the risk of cancer in humans who are exposed at lower levels 

over long periods of time. EPA has set forth the enforceable drinking 

water standard for trichloroethylene at 0.005 parts per million (ppm) to 

reduce the risk of cancer or other adverse health effects which have 

been observed in laboratory animals. Drinking water which meets this 

standard is associated with little to none of this risk and should be 

considered safe.

    (2) Carbon tetrachloride. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

carbon tetrachloride is a health concern at certain levels of exposure. 

This chemical was once a popular household cleaning fluid. It generally 

gets into drinking water by improper waste disposal. This chemical has 

been shown to cause cancer in laboratory animals such as rats and mice 

when the animals are exposed at high levels over



[[Page 395]]



their lifetimes. Chemicals that cause cancer in laboratory animals also 

may increase the risk of cancer in humans who are exposed at lower 

levels over long periods of of time. EPA has set the enforceable 

drinking water standard for carbon tetrachloride at 0.005 parts per 

million (ppm) to reduce the risk of cancer or other adverse health 

effects which have been observed in laboratory animals. Drinking water 

which meets this standard is associated with little to none of this risk 

and should be considered safe.

    (3) 1,2-Dichloroethane. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 1,2-

dichloroethane is a health concern at certain levels of exposure. This 

chemical is used as a cleaning fluid for fats, oils, waxes, and resins. 

It generally gets into drinking water from improper waste disposal. This 

chemical has been shown to cause cancer in laboratory animals such as 

rats and mice when the animals are exposed at high levels over their 

lifetimes. Chemicals that cause cancer in laboratory animals also may 

increase the risk of cancer in humans who are exposed at lower levels 

over long periods of time. EPA has set the enforceable drinking water 

standard for 1,2-dichloroethane at 0.005 parts per million (ppm) to 

reduce the risk of cancer or other adverse health effects which have 

been observed in laboratory animals. Drinking water which meets this 

standard is associated with little to none of this risk and should be 

considered safe.

    (4) Vinyl chloride. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that vinyl 

chloride is a health concern at certain levels of exposure. This 

chemical is used in industry and is found in drinking water as a result 

of the breakdown of related solvents. The solvents are used as cleaners 

and degreasers of metals and generally get into drinking water by 

improper waste disposal. This chemical has been associated with 

significantly increased risks of cancer among certain industrial workers 

who were exposed to relatively large amounts of this chemical during 

their working careers. This chemical has also been shown to cause cancer 

in laboratory animals when the animals are exposed at high levels over 

their lifetimes. Chemicals that cause increased risk of cancer among 

exposed industrial workers and in laboratory animals also may increase 

the risk of cancer in humans who are exposed at lower levels over long 

periods of time. EPA has set the enforceable drinking water standard for 

vinyl chloride at 0.002 part per million (ppm) to reduce the risk of 

cancer or other adverse health effects which have been observed in 

humans and laboratory animals. Drinking water which meets this standard 

is associated with little to none of this risk and should be considered 

safe.

    (5) Benzene. The United States Environmental Protection Agency (EPA) 

sets drinking water standards and has determined that benzene is a 

health concern at certain levels of exposure. This chemical is used as a 

solvent and degreaser of metals. It is also a major component of 

gasoline. Drinking water contamination generally results from leaking 

undergound gasoline and petroleum tanks or improper waste disposal. This 

chemical has been associated with significantly increased risks of 

leukemia among certain industrial workers who were exposed to relatively 

large amounts of this chemical during their working careers. This 

chemical has also been shown to cause cancer in laboratory animals when 

the animals are exposed at high levels over their lifetimes. Chemicals 

that cause increased risk of cancer among exposed industrial workers and 

in laboratory animals also may increase the risk of cancer in humans who 

are exposed at lower levels over long periods of time. EPA has set the 

enforceable drinking water standard for benzene at 0.005 parts per 

million (ppm) to reduce the risk of cancer or other adverse health 

effects which have been observed in humans and laboratory animals. 

Drinking water which meets this standard is associated with little to 

none of this risk and should be considered safe.

    (6) 1,1-Dichloroethylene. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 1,1-

dichloroethylene is a health concern at



[[Page 396]]



certain levels of exposure. This chemical is used in industry and is 

found in drinking water as a result of the breakdown of related 

solvents. The solvents are used as cleaners and degreasers of metals and 

generally get into drinking water by improper waste disposal. This 

chemical has been shown to cause liver and kidney damage in laboratory 

animals such as rats and mice when the animals are exposed at high 

levels over their lifetimes. Chemicals which cause adverse effects in 

laboratory animals also may cause adverse health effects in humans who 

are exposed at lower levels over long periods of time. EPA has set the 

enforceable drinking water standard for 1,1-dichloroethylene at 0.007 

parts per million (ppm) to reduce the risk of these adverse health 

effects which have been observed in laboratory animals. Drinking water 

which meets this standard is associated with little to none of this risk 

and should be considered safe.

    (7) Para-dichlorobenzene. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that para-

dichlorobenzene is a health concern at certain levels of exposure. This 

chemical is a component of deodorizers, moth balls, and pesticides. It 

generally gets into drinking water by improper waste disposal. This 

chemical has been shown to cause liver and kidney damage in laboratory 

animals such as rats and mice when the animals are exposed to high 

levels over their lifetimes. Chemicals which cause adverse effects in 

laboratory animals also may cause adverse health effects in humans who 

are exposed at lower levels over long periods of time. EPA has set the 

enforceable drinking water standard for para-dichlorobenzene at 0.075 

parts per million (ppm) to reduce the risk of these adverse health 

effects which have been observed in laboratory animals. Drinking water 

which meets this standard is associated with little to none of this risk 

and should be considered safe.

    (8) 1,1,1-Trichloroethane. The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

that the 1,1,1-trichloroethane is a health concern at certain levels of 

exposure. This chemical is used as a cleaner and degreaser of metals. It 

generally gets into drinking water by improper waste disposal. This 

chemical has been shown to damage the liver, nervous system, and 

circulatory system of laboratory animals such as rats and mice when the 

animals are exposed at high levels over their lifetimes. Some industrial 

workers who were exposed to relatively large amounts of this chemical 

during their working careers also suffered damage to the liver, nervous 

system, and circulatory system. Chemicals which cause adverse effects 

among exposed industrial workers and in laboratory animals also may 

cause adverse health effects in humans who are exposed at lower levels 

over long periods of time. EPA has set the enforceable drinking water 

standard for 1,1,1-trichloroethane at 0.2 parts per million (ppm) to 

protect against the risk of these adverse health effects which have been 

observed in humans and laboratory animals. Drinking water which meets 

this standard is associated with little to none of this risk and should 

be considered safe.

    (9) Fluoride.

    [Note: EPA is not specifying language that must be included in a 

public notice for a violation of the fluoride maximum contaminant level 

in this section because Sec. 143.5 of this part includes the necessary 

information. See paragraph (f) of this section.]

    (10) Microbiological contaminants (for use when there is a violation 

of the treatment technique requirements for filtration and disinfection 

in subpart H or subpart P of this part). The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

that the presence of microbiological contaminants are a health concern 

at certain levels of exposure. If water is inadequately treated, 

microbiological contaminants in that water may cause disease. Disease 

symptoms may include diarrhea, cramps, nausea, and possibly jaundice, 

and any associated headaches and fatigue. These symptoms, however, are 

not just associated with disease-causing organisms in drinking water, 

but also may be caused by a number of factors other than your drinking 

water. EPA has set enforceable requirements for treating drinking water 

to reduce the risk of these adverse health



[[Page 397]]



effects. Treatment such as filtering and disinfecting the water removes 

or destroys microbiological contaminants. Drinking water which is 

treated to meet EPA requirements is associated with little to none of 

this risk and should be considered safe.

    (11) Total coliforms (To be used when there is a violation of Sec. 

141.63(a), and not a violation of Sec. 141.63(b)). The United States 

Environmental Protection Agency (EPA) sets drinking water standards and 

has determined that the presence of total coliforms is a possible health 

concern. Total coliforms are common in the environment and are generally 

not harmful themselves. The presence of these bacteria in drinking 

water, however, generally is a result of a problem with water treatment 

or the pipes which distribute the water, and indicates that the water 

may be contaminated with organisms that can cause disease. Disease 

symptoms may include diarrhea, cramps, nausea, and possibly jaundice, 

and any associated headaches and fatigue. These symptoms, however, are 

not just associated with disease-causing organisms in drinking water, 

but also may be caused by a number of factors other than your drinking 

water. EPA has set an enforceable drinking water standard for total 

coliforms to reduce the risk of these adverse health effects. Under this 

standard, no more than 5.0 percent of the samples collected during a 

month can contain these bacteria, except that systems collecting fewer 

than 40 samples/month that have one total coliform-positive sample per 

month are not violating the standard. Drinking water which meets this 

standard is usually not associated with a health risk from disease-

causing bacteria and should be considered safe.

    (12) Fecal Coliforms/E. coli (To be used when there is a violation 

of Sec. 141.63(b) or both Sec. 141.63 (a) and (b)). The United States 

Environmental Protection Agency (EPA) sets drinking water standards and 

has determined that the presence of fecal coliforms or E. coli is a 

serious health concern. Fecal coliforms and E. coli are generally not 

harmful themselves, but their presence in drinking water is serious 

because they usually are associated with sewage or animal wastes. The 

presence of these bacteria in drinking water is generally a result of a 

problem with water treatment or the pipes which distribute the water, 

and indicates that the water may be contaminated with organisms that can 

cause disease. Disease symptoms may include diarrhea, cramps, nausea, 

and possibly jaundice, and associated headaches and fatigue. These 

symptoms, however, are not just associated with disease-causing 

organisms in drinking water, but also may be caused by a number of 

factors other than your drinking water. EPA has set an enforceable 

drinking water standard for fecal coliforms and E. coli to reduce the 

risk of these adverse health effects. Under this standard all drinking 

water samples must be free of these bacteria. Drinking water which meets 

this standard is associated with little or none of this risk and should 

be considered safe. State and local health authorities recommend that 

consumers take the following precautions: [To be inserted by the public 

water system, according to instructions from State or local 

authorities].

    (13) Lead. The United States Environmental Protection Agency (EPA) 

sets drinking water standards and has determined that lead is a health 

concern at certain exposure levels. Materials that contain lead have 

frequently been used in the construction of water supply distribution 

systems, and plumbing systems in private homes and other buildings. The 

most commonly found materials include service lines, pipes, brass and 

bronze fixtures, and solders and fluxes. Lead in these materials can 

contaminate drinking water as a result of the corrosion that takes place 

when water comes into contact with those materials. Lead can cause a 

variety of adverse health effects in humans. At relatively low levels of 

exposure, these effects may include interference with red blood cell 

chemistry, delays in normal physical and mental development in babies 

and young children, slight deficits in the attention span, hearing, and 

learning abilities of children, and slight increases in the blood 

pressure of some adults. EPA's national primary drinking water 

regulation requires all



[[Page 398]]



public water systems to optimize corrosion control to minimize lead 

contamination resulting from the corrosion of plumbing materials. Public 

water systems serving 50,000 people or fewer that have lead 

concentrations below 15 parts per billion (ppb) in more than 90% of tap 

water samples (the EPA ``action level'') have optimized their corrosion 

control treatment. Any water system that exceeds the action level must 

also monitor their source water to determine whether treatment to remove 

lead in source water is needed. Any water system that continues to 

exceed the action level after installation of corrosion control and/or 

source water treatment must eventually replace all lead service lines 

contributing in excess of 15 (ppb) of lead to drinking water. Any water 

system that exceeds the action level must also undertake a public 

education program to inform consumers of ways they can reduce their 

exposure to potentially high levels of lead in drinking water.

    (14) Copper. The United States Environmental Protection Agency (EPA) 

sets drinking water standards and has determined that copper is a health 

concern at certain exposure levels. Copper, a reddish-brown metal, is 

often used to plumb residential and commercial structures that are 

connected to water distribution systems. Copper contaminating drinking 

water as a corrosion byproduct occurs as the result of the corrosion of 

copper pipes that remain in contact with water for a prolonged period of 

time. Copper is an essential nutrient, but at high doses it has been 

shown to cause stomach and intestinal distress, liver and kidney damage, 

and anemia. Persons with Wilson's disease may be at a higher risk of 

health effects due to copper than the general public. EPA's national 

primary drinking water regulation requires all public water systems to 

install optimal corrosion control to minimize copper contamination 

resulting from the corrosion of plumbing materials. Public water systems 

serving 50,000 people or fewer that have copper concentrations below 1.3 

parts per million (ppm) in more than 90% of tap water samples (the EPA 

``action level'') are not required to install or improve their 

treatment. Any water system that exceeds the action level must also 

monitor their source water to determine whether treatment to remove 

copper in source water is needed.

    (15) Asbestos. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that asbestos 

fibers greater than 10 micrometers in length are a health concern at 

certain levels of exposure. Asbestos is a naturally occurring mineral. 

Most asbestos fibers in drinking water are less than 10 micrometers in 

length and occur in drinking water from natural sources and from 

corroded asbestos-cement pipes in the distribution system. The major 

uses of asbestos were in the production of cements, floor tiles, paper 

products, paint, and caulking; in transportation-related applications; 

and in the production of textiles and plastics. Asbestos was once a 

popular insulating and fire retardent material. Inhalation studies have 

shown that various forms of asbestos have produced lung tumors in 

laboratory animals. The available information on the risk of developing 

gastrointestinal tract cancer associated with the ingestion of asbestos 

from drinking water is limited. Ingestion of intermediate-range 

chrysotile asbestos fibers greater than 10 micrometers in length is 

associated with causing benign tumors in male rats. Chemicals that cause 

cancer in laboratory animals also may increase the risk of cancer in 

humans who are exposed over long periods of time. EPA has set the 

drinking water standard for asbestos at 7 million long fibers per liter 

to reduce the potential risk of cancer or other adverse health effects 

which have been observed in laboratory animals. Drinking water which 

meets the EPA standard is associated with little to none of this risk 

and should be considered safe with respect to asbestos.

    (16) Barium. The United States Environmental Protection Agency (EPA) 

sets drinking water standards and has determined that barium is a health 

concern at certain levels of exposure. This inorganic chemical occurs 

naturally in some aquifers that serve as sources of ground water. It is 

also used in oil and gas drilling muds, automotive paints, bricks, tiles 

and jet fuels. It generally gets into drinking



[[Page 399]]



water after dissolving from naturally occurring minerals in the ground. 

This chemical may damage the heart and cardiovascular system, and is 

associated with high blood pressure in laboratory animals such as rats 

exposed to high levels during their lifetimes. In humans, EPA believes 

that effects from barium on blood pressure should not occur below 2 

parts per million (ppm) in drinking water. EPA has set the drinking 

water standard for barium at 2 parts per million (ppm) to protect 

against the risk of these adverse health effects. Drinking water that 

meets the EPA standard is associated with little to none of this risk 

and is considered safe with respect to barium.

    (17) Cadmium. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that cadmium is a 

health concern at certain levels of exposure. Food and the smoking of 

tobacco are common sources of general exposure. This inorganic metal is 

a contaminant in the metals used to galvanize pipe. It generally gets 

into water by corrosion of galvanized pipes or by improper waste 

disposal. This chemical has been shown to damage the kidney in animals 

such as rats and mice when the animals are exposed at high levels over 

their lifetimes. Some industrial workers who were exposed to relatively 

large amounts of this chemical during working careers also suffered 

damage to the kidney. EPA has set the drinking water standard for 

cadmium at 0.005 parts per million (ppm) to protect against the risk of 

these adverse health effects. Drinking water that meets the EPA standard 

is associated with little to none of this risk and is considered safe 

with respect to cadmium.

    (18) Chromium. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that chromium is 

a health concern at certain levels of exposure. This inorganic metal 

occurs naturally in the ground and is often used in the electroplating 

of metals. It generally gets into water from runoff from old mining 

operations and improper waste disposal from plating operations. This 

chemical has been shown to damage the kidney, nervous system, and the 

circulatory system of laboratory animals such as rats and mice when the 

animals are exposed at high levels. Some humans who were exposed to high 

levels of this chemical suffered liver and kidney damage, dermatitis and 

respiratory problems. EPA has set the drinking water standard for 

chromium at 0.1 parts per million (ppm) to protect against the risk of 

these adverse health effects. Drinking water that meets the EPA standard 

is associated with little to none of this risk and is considered safe 

with respect to chromium.

    (19) Mercury. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that mercury is a 

health concern at certain levels of exposure. This inorganic metal is 

used in electrical equipment and some water pumps. It usually gets into 

water as a result of improper waste disposal. This chemical has been 

shown to damage the kidney of laboratory animals such as rats when the 

animals are exposed at high levels over their lifetimes. EPA has set the 

drinking water standard for mercury at 0.002 parts per million (ppm) to 

protect against the risk of these adverse health effects. Drinking water 

that meets the EPA standard is associated with little to none of this 

risk and is considered safe with respect to mercury.

    (20) Nitrate. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that nitrate 

poses an acute health concern at certain levels of exposure. Nitrate is 

used in fertilizer and is found in sewage and wastes from human and/or 

farm animals and generally gets into drinking water from those 

activities. Excessive levels of nitrate in drinking water have caused 

serious illness and sometimes death in infants under six months of age. 

The serious illness in infants is caused because nitrate is converted to 

nitrite in the body. Nitrite interferes with the oxygen carrying 

capacity of the child's blood. This is an acute disease in that symptoms 

can develop rapidly in infants. In most cases, health deteriorates over 

a period of days. Symptoms



[[Page 400]]



include shortness of breath and blueness of the skin. Clearly, expert 

medical advice should be sought immediately if these symptoms occur. The 

purpose of this notice is to encourage parents and other responsible 

parties to provide infants with an alternate source of drinking water. 

Local and State health authorities are the best source for information 

concerning alternate sources of drinking water for infants. EPA has set 

the drinking water standard at 10 parts per million (ppm) for nitrate to 

protect against the risk of these adverse effects. EPA has also set a 

drinking water standard for nitrite at 1 ppm. To allow for the fact that 

the toxicity of nitrate and nitrite are additive, EPA has also 

established a standard for the sum of nitrate and nitrite at 10 ppm. 

Drinking water that meets the EPA standard is associated with little to 

none of this risk and is considered safe with respect to nitrate.

    (21) Nitrite. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that nitrite 

poses an acute health concern at certain levels of exposure. This 

inorganic chemical is used in fertilizers and is found in sewage and 

wastes from humans and/or farm animals and generally gets into drinking 

water as a result of those activities. While excessive levels of nitrite 

in drinking water have not been observed, other sources of nitrite have 

caused serious illness and sometimes death in infants under six months 

of age. The serious illness in infants is caused because nitrite 

interferes with the oxygen carrying capacity of the child's blood. This 

is an acute disease in that symptoms can develop rapidly. However, in 

most cases, health deteriorates over a period of days. Symptoms include 

shortness of breath and blueness of the skin. Clearly, expert medical 

advice should be sought immediately if these symptoms occur. The purpose 

of this notice is to encourage parents and other responsible parties to 

provide infants with an alternate source of drinking water. Local and 

State health authorities are the best source for information concerning 

alternate sources of drinking water for infants. EPA has set the 

drinking water standard at 1 part per million (ppm) for nitrite to 

protect against the risk of these adverse effects. EPA has also set a 

drinking water standard for nitrate (converted to nitrite in humans) at 

10 ppm and for the sum of nitrate and nitrite at 10 ppm. Drinking water 

that meets the EPA standard is associated with little to none of this 

risk and is considered safe with respect to nitrite.

    (22) Selenium. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that selenium is 

a health concern at certain high levels of exposure. Selenium is also an 

essential nutrient at low levels of exposure. This inorganic chemical is 

found naturally in food and soils and is used in electronics, photocopy 

operations, the manufacture of glass, chemicals, drugs, and as a 

fungicide and a feed additive. In humans, exposure to high levels of 

selenium over a long period of time has resulted in a number of adverse 

health effects, including a loss of feeling and control in the arms and 

legs. EPA has set the drinking water standard for selenium at 0.05 parts 

per million (ppm) to protect against the risk of these adverse health 

effects. Drinking water that meets the EPA standard is associated with 

little to none of this risk and is considered safe with respect to 

selenium.

    (23) Acrylamide. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that acrylamide 

is a health concern at certain levels of exposure. Polymers made from 

acrylamide are sometimes used to treat water supplies to remove 

particulate contaminants. Acrylamide has been shown to cause cancer in 

laboratory animals such as rats and mice when the animals are exposed at 

high levels over their lifetimes. Chemicals that cause cancer in 

laboratory animals also may increase the risk of cancer in humans who 

are exposed over long periods of time. Sufficiently large doses of 

acrylamide are known to cause neurological injury. EPA has set the 

drinking water standard for acrylamide using a treatment technique to 

reduce the risk of cancer or other adverse health effects which have 

been observed in laboratory animals. This treatment technique limits the 

amount



[[Page 401]]



of acrylamide in the polymer and the amount of the polymer which may be 

added to drinking water to remove particulates. Drinking water systems 

which comply with this treatment technique have little to no risk and 

are considered safe with respect to acrylamide.

    (24) Alachlor. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that alachlor is 

a health concern at certain levels of exposure. This organic chemical is 

a widely used pesticide. When soil and climatic conditions are 

favorable, alachlor may get into drinking water by runoff into surface 

water or by leaching into ground water. This chemical has been shown to 

cause cancer in laboratory animals such as rats and mice when the 

animals are exposed at high levels over their lifetimes. Chemicals that 

cause cancer in laboratory animals also may increase the risk of cancer 

in humans who are exposed over long periods of time. EPA has set the 

drinking water standard for alachlor at 0.002 parts per million (ppm) to 

reduce the risk of cancer or other adverse health effects which have 

been observed in laboratory animals. Drinking water that meets this 

standard is associated with little to none of this risk and is 

considered safe with respect to alachlor.

    (25) Aldicarb. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that aldicarb is 

a health concern at certain levels of exposure. Aldicarb is a widely 

used pesticide. Under certain soil and climatic conditions (e.g., sandy 

soil and high rainfall), aldicarb may leach into ground water after 

normal agricultural applications to crops such as potatoes or peanuts or 

may enter drinking water supplies as a result of surface runoff. This 

chemical has been shown to damage the nervous system in laboratory 

animals such as rats and dogs exposed to high levels. EPA has set the 

drinking water standard for aldicarb at 0.003 parts per million (ppm) to 

protect against the risk of adverse health effects. Drinking water that 

meets the EPA standard is associated with little to none of this risk 

and is considered safe with respect to aldicarb.

    (26) Aldicarb sulfoxide. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

aldicarb sulfoxide is a health concern at certain levels of exposure. 

Aldicarb is a widely used pesticide. Aldicarb sulfoxide in ground water 

is primarily a breakdown product of aldicarb. Under certain soil and 

climatic conditions (e.g., sandy soil and high rainfall), aldicarb 

sulfoxide may leach into ground water after normal agricultural 

applications to crops such as potatoes or peanuts or may enter drinking 

water supplies as a result of surface runoff. This chemical has been 

shown to damage the nervous system in laboratory animals such as rats 

and dogs exposed to high levels. EPA has set the drinking water standard 

for aldicarb sulfoxide at 0.004 parts per million (ppm) to protect 

against the risk of adverse health effects. Drinking water that meets 

the EPA standard is associated with little to none of this risk and is 

considered safe with respect to aldicarb sulfoxide.

    (27) Aldicarb sulfone. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

aldicarb sulfone is a health concern at certain levels of exposure. 

Aldicarb is a widely used pesticide. Aldicarb sulfone is formed from the 

breakdown of aldicarb and is considered for registration as a pesticide 

under the name aldoxycarb. Under certain soil and climatic conditions 

(e.g., sandy soil and high rainfall), aldicarb sulfone may leach into 

ground water after normal agricultural applications to crops such as 

potatoes or peanuts or may enter drinking water supplies as a result of 

surface runoff. This chemical has been shown to damage the nervous 

system in laboratory animals such as rats and dogs exposed to high 

levels. EPA has set the drinking water standard for aldicarb sulfone at 

0.002 parts per million (ppm) to protect against the risk of adverse 

health effects. Drinking water that meets the EPA standard is associated 

with little to none of this risk and is considered safe with respect to 

aldicarb sulfone.

    (28) Atrazine. The United States Environmental Protection Agency 

(EPA)



[[Page 402]]



sets drinking water standards and has determined that atrazine is a 

health concern at certain levels of exposure. This organic chemical is a 

herbicide. When soil and climatic conditions are favorable, atrazine may 

get into drinking water by runoff into surface water or by leaching into 

ground water. This chemical has been shown to affect offspring of rats 

and the heart of dogs. EPA has set the drinking water standard for 

atrazine at 0.003 parts per million (ppm) to protect against the risk of 

these adverse health effects. Drinking water that meets the EPA standard 

is associated with little to none of this risk and is considered safe 

with respect to atrazine.

    (29) Carbofuran. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that carbofuran 

is a health concern at certain levels of exposure. This organic chemical 

is a pesticide. When soil and climatic conditions are favorable, 

carbofuran may get into drinking water by runoff into surface water or 

by leaching into ground water. This chemical has been shown to damage 

the nervous and reproductive systems of laboratory animals such as rats 

and mice exposed at high levels over their lifetimes. Some humans who 

were exposed to relatively large amounts of this chemical during their 

working careers also suffered damage to the nervous system. Effects on 

the nervous system are generally rapidly reversible. EPA has set the 

drinking water standard for carbofuran at 0.04 parts per million (ppm) 

to protect against the risk of these adverse health effects. Drinking 

water that meets the EPA standard is associated with little to none of 

this risk and is considered safe with respect to carbofuran.

    (30) Chlordane. The United States Environmental Protection Agency 

(EPA sets drinking water standards and has determined that chlordane is 

a health concern at certain levels of exposure. This organic chemical is 

a pesticide used to control termites. Chlordane is not very mobile in 

soils. It usually gets into drinking water after application near water 

supply intakes or wells. This chemical has been shown to cause cancer in 

laboratory animals such as rats and mice when the animals are exposed at 

high levels over their lifetimes. Chemicals that cause cancer in 

laboratory animals also may increase the risk of cancer in humans who 

are exposed over long periods of time. EPA has set the drinking water 

standard for chlordane at 0.002 parts per million (ppm) to reduce the 

risk of cancer or other adverse health effects which have been observed 

in laboratory animals. Drinking water that meets the EPA standard is 

associated with little to none of this risk and is considered safe with 

respect to chlordane.

    (31) Dibromochloropropane (DBCP). The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

that DBCP is a health concern at certain levels of exposure. This 

organic chemical was once a popular pesticide. When soil and climatic 

conditions are favorable, dibromochloropropane may get into drinking 

water by runoff into surface water or by leaching into ground water. 

This chemical has been shown to cause cancer in laboratory animals such 

as rats and mice when the animals are exposed at high levels over their 

lifetimes. Chemicals that cause cancer in laboratory animals also may 

increase the risk of cancer in humans who are exposed over long periods 

of time. EPA has set the drinking water standard for DBCP at 0.0002 

parts per million (ppm) to reduce the risk of cancer or other adverse 

health effects which have been observed in laboratory animals. Drinking 

water that meets the EPA standard is associated with little to none of 

this risk and is considered safe with respect to DBCP.

    (32) o-Dichlorobenzene. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that o-

dichlorobenzene is a health concern at certain levels of exposure. This 

organic chemical is used as a solvent in the production of pesticides 

and dyes. It generally gets into water by improper waste disposal. This 

chemical has been shown to damage the liver, kidney and the blood cells 

of laboratory animals such as rats and mice exposed to high levels 

during their lifetimes. Some industrial workers who were exposed to



[[Page 403]]



relatively large amounts of this chemical during working careers also 

suffered damage to the liver, nervous system, and circulatory system. 

EPA has set the drinking water standard for o-dichlorobenzene at 0.6 

parts per million (ppm) to protect against the risk of these adverse 

health effects. Drinking water that meets the EPA standard is associated 

with little to none of this risk and is considered safe with respect to 

o-dichlorobenzene.

    (33) cis-1,2-Dichloroethylene. The United States Environmental 

Protection Agency (EPA) establishes drinking water standards and has 

determined that cis-1,2-dichloroethylene is a health concern at certain 

levels of exposure. This organic chemical is used as a solvent and 

intermediate in chemical production. It generally gets into water by 

improper waste disposal. This chemical has been shown to damage the 

liver, nervous system, and circulatory system of laboratory animals such 

as rats and mice when exposed at high levels over their lifetimes. Some 

humans who were exposed to relatively large amounts of this chemical 

also suffered damage to the nervous system. EPA has set the drinking 

water standard for cis-1,2-dichloroethylene at 0.07 parts per million 

(ppm) to protect against the risk of these adverse health effects. 

Drinking water that meets the EPA standard is associated with little to 

none of this risk and is considered safe with respect to cis-1,2-

dichloroethylene.

    (34) trans-1,2-Dichloroethylene. The United States Environmental 

Protection Agency (EPA) establishes drinking water standards and has 

determined that trans-1,2-dichloroethylene is a health concern at 

certain levels of exposure. This organic chemical is used as a solvent 

and intermediate in chemical production. It generally gets into water by 

improper waste disposal. This chemical has been shown to damage the 

liver, nervous system, and the circulatory system of laboratory animals 

such as rats and mice when exposed at high levels over their lifetimes. 

Some humans who were exposed to relatively large amounts of this 

chemical also suffered damage to the nervous system. EPA has set 

drinking water standard for trans-1,2-dichloroethylene at 0.1 parts per 

million (ppm) to protect against the risk of these adverse health 

effects. Drinking water that meets the EPA standard is associated with 

little to none of this risk and is considered safe with respect to 

trans-1,2-dichloroethylene.

    (35) 1,2-Dichloropropane. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 1,2-

dichloropropane is a health concern at certain levels of exposure. This 

organic chemical is used as a solvent and pesticide. When soil and 

climatic conditions are favorable, 1,2-dichloropropane may get into 

drinking water by runoff into surface water or by leaching into ground 

water. It may also get into drinking water through improper waste 

disposal. This chemical has been shown to cause cancer in laboratory 

animals such as rats and mice when the animals are exposed at high 

levels over their lifetimes. Chemicals that cause cancer in laboratory 

animals also may increase the risk of cancer in humans who are exposed 

over long periods of time. EPA has set the drinking water standard for 

1,2-dichloropropane at 0.005 parts per million (ppm) to reduce the risk 

of cancer or other adverse health effects which have been observed in 

laboratory animals. Drinking water that meets the EPA standard is 

associated with little to none of this risk and is considered safe with 

respect to 1,2-dichloropropane.

    (36) 2,4-D. The United States Environmental Protection Agency (EPA) 

sets drinking water standards and has determined that 2,4-D is a health 

concern at certain levels of exposure. This organic chemical is used as 

a herbicide and to control algae in reservoirs. When soil and climatic 

conditions are favorable, 2,4-D may get into drinking water by runoff 

into surface water or by leaching into ground water. This chemical has 

been shown to damage the liver and kidney of laboratory animals such as 

rats exposed at high levels during their lifetimes. Some humans who were 

exposed to relatively large amounts of this chemical also suffered 

damage to the nervous system. EPA has set the drinking water standard 

for 2,4-D at 0.07 parts per million (ppm) to protect against the risk of



[[Page 404]]



these adverse health effects. Drinking water that meets the EPA standard 

is associated with little to none of this risk and is considered safe 

with respect to 2,4-D.

    (37) Epichlorohydrin. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

epichlorohydrin is a health concern at certain levels of exposure. 

Polymers made from epichlorohydrin are sometimes used in the treatment 

of water supplies as a flocculent to remove particulates. 

Epichlorohydrin generally gets into drinking water by improper use of 

these polymers. This chemical has been shown to cause cancer in 

laboratory animals such as rats and mice when the animals are exposed at 

high levels over their lifetimes. Chemicals that cause cancer in 

laboratory animals also may increase the risk of cancer in humans who 

are exposed over long periods of time. EPA has set the drinking water 

standard for epichlorohydrin using a treatment technique to reduce the 

risk of cancer or other adverse health effects which have been observed 

in laboratory animals. This treatment technique limits the amount of 

epichlorohydrin in the polymer and the amount of the polymer which may 

be added to drinking water as a flocculent to remove particulates. 

Drinking water systems which comply with this treatment technique have 

little to no risk and are considered safe with respect to 

epichlorohydrin.

    (38) Ethylbenzene. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined ethylbenzene is a 

health concern at certain levels of exposure. This organic chemical is a 

major component of gasoline. It generally gets into water by improper 

waste disposal or leaking gasoline tanks. This chemical has been shown 

to damage the kidney, liver, and nervous system of laboratory animals 

such as rats exposed to high levels during their lifetimes. EPA has set 

the drinking water standard for ethylbenzene at 0.7 part per million 

(ppm) to protect against the risk of these adverse health effects. 

Drinking water that meets the EPA standard is associated with little to 

none of this risk and is considered safe with respect to ethylbenzene.

    (39) Ethylene dibromide (EDB). The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

that EDB is a health concern at certain levels of exposure. This organic 

chemical was once a popular pesticide. When soil and climatic conditions 

are favorable, EDB may get into drinking water by runoff into surface 

water or by leaching into ground water. This chemical has been shown to 

cause cancer in laboratory animals such as rats and mice when the 

animals are exposed at high levels over their lifetimes. Chemicals that 

cause cancer in laboratory animals also may increase the risk of cancer 

in humans who are exposed over long periods of time. EPA has set the 

drinking water standard for EDB at 0.00005 part per million (ppm) to 

reduce the risk of cancer or other adverse health effects which have 

been observed in laboratory animals. Drinking water that meets this 

standard is associated with little to none of this risk and is 

considered safe with respect to EDB.

    (40) Heptachlor. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that heptachlor 

is a health concern at certain levels of exposure. This organic chemical 

was once a popular pesticide. When soil and climatic conditions are 

favorable, heptachlor may get into drinking water by runoff into surface 

water or by leaching into ground water. This chemical has been shown to 

cause cancer in laboratory animals such as rats and mice when the 

animals are exposed at high levels over their lifetimes. Chemicals that 

cause cancer in laboratory animals also may increase the risk of cancer 

in humans who are exposed over long periods of time. EPA has set the 

drinking water standards for heptachlor at 0.0004 part per million (ppm) 

to reduce the risk of cancer or other adverse health effects which have 

been observed in laboratory animals. Drinking water that meets this 

standard is associated with little to none of this risk and is 

considered safe with respect to heptachlor.



[[Page 405]]



    (41) Heptachlor epoxide. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

heptachlor epoxide is a health concern at certain levels of exposure. 

This organic chemical was once a popular pesticide. When soil and 

climatic conditions are favorable, heptachlor expoxide may get into 

drinking water by runoff into surface water or by leaching into ground 

water. This chemical has been shown to cause cancer in laboratory 

animals such as rats and mice when the animals are exposed at high 

levels over their lifetimes. Chemicals that cause cancer in laboratory 

animals also may increase the risk of cancer in humans who are exposed 

over long periods of time. EPA has set the drinking water standards for 

heptachlor epoxide at 0.0002 part per million (ppm) to reduce the risk 

of cancer or other adverse health effects which have been observed in 

laboratory animals. Drinking water that meets this standard is 

associated with little to none of this risk and is considered safe with 

respect to heptachlor epoxide.

    (42) Lindane. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that lindane is a 

health concern at certain levels of exposure. This organic chemical is 

used as a pesticide. When soil and climatic conditions are favorable, 

lindane may get into drinking water by runoff into surface water or by 

leaching into ground water. This chemical has been shown to damage the 

liver, kidney, nervous system, and immune system of laboratory animals 

such as rats, mice and dogs exposed at high levels during their 

lifetimes. Some humans who were exposed to relatively large amounts of 

this chemical also suffered damage to the nervous system and circulatory 

system. EPA has established the drinking water standard for lindane at 

0.0002 part per million (ppm) to protect against the risk of these 

adverse health effects. Drinking water that meets the EPA standard is 

associated with little to none of this risk and is considered safe with 

respect to lindane.

    (43) Methoxychlor. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that methoxychlor 

is a health concern at certain levels of exposure. This organic chemical 

is used as a pesticide. When soil and climatic conditions are favorable, 

methoxychlor may get into drinking water by runoff into surface water or 

by leaching into ground water. This chemical has been shown to damage 

the liver, kidney, nervous system, and reproductive system of laboratory 

animals such as rats exposed at high levels during their lifetimes. It 

has also been shown to produce growth retardation in rats. EPA has set 

the drinking water standard for methoxychlor at 0.04 part per million 

(ppm) to protect against the risk of these adverse health effects. 

Drinking water that meets the EPA standard is associated with little to 

none of this risk and is considered safe with respect to methoxychlor.

    (44) Monochlorobenzene. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

monochlorobenzene is a health concern at certain levels of exposure. 

This organic chemical is used as a solvent. It generally gets into water 

by improper waste disposal. This chemical has been shown to damage the 

liver, kidney and nervous system of laboratory animals such as rats and 

mice exposed to high levels during their lifetimes. EPA has set the 

drinking water standard for monochlorobenzene at 0.1 part per million 

(ppm) to protect against the risk of these adverse health effects. 

Drinking water that meets the EPA standard is associated with little to 

none of this risk and is considered safe with respect to 

monochlorobenzene.

    (45) Polychlorinated biphenyls (PCBs). The United States 

Environmental Protection Agency (EPA) sets drinking water standards and 

has determined that polychlorinated biphenyls (PCBs) are a health 

concern at certain levels of exposure. These organic chemicals were once 

widely used in electrical transformers and other industrial equipment. 

They generally get into drinking water by improper waste disposal or 

leaking electrical industrial equipment. This chemical has been shown to 

cause cancer in laboratory animals such as rats and mice when the 

animals are exposed at high levels



[[Page 406]]



over their lifetimes. Chemicals that cause cancer in laboratory animals 

also may increase the risk of cancer in humans who are exposed over long 

periods of time. EPA has set the drinking water standard for PCBs at 

0.0005 part per million (ppm) to reduce the risk of cancer or other 

adverse health effects which have been observed in laboratory animals. 

Drinking water that meets this standard is associated with little to 

none of this risk and is considered safe with respect to PCBs.

    (46) Pentachlorophenol. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

pentachlorophenol is a health concern at certain levels of exposure. 

This organic chemical is used as a wood preservative, herbicide, 

disinfectant, and defoliant. It generally gets into drinking water by 

runoff into surface water or leaching into ground water. This chemical 

has been shown to produce adverse reproductive effects and to damage the 

liver and kidneys of laboratory animals such as rats exposed to high 

levels during their lifetimes. Some humans who were exposed to 

relatively large amounts of this chemical also suffered damage to the 

liver and kidneys. This chemical has been shown to cause cancer in 

laboratory animals such as rats and mice when the animals are exposed to 

high levels over their lifetimes. Chemicals that cause cancer in 

laboratory animals also may increase the risk of cancer in humans who 

are exposed over long periods of time. EPA has set the drinking water 

standard for pentachlorophenol at 0.001 parts per million (ppm) to 

protect against the risk of cancer or other adverse health effects. 

Drinking water that meets the EPA standard is associated with little to 

none of this risk and is considered safe with respect to 

pentachlorophenol.

    (47) Styrene. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that styrene is a 

health concern at certain levels of exposure. This organic chemical is 

commonly used to make plastics and is sometimes a component of resins 

used for drinking water treatment. Styrene may get into drinking water 

from improper waste disposal. This chemical has been shown to damage the 

liver and nervous system in laboratory animals when exposed at high 

levels during their lifetimes. EPA has set the drinking water standard 

for styrene at 0.1 part per million (ppm) to protect against the risk of 

these adverse health effects. Drinking water that meets the EPA standard 

is associated with little to none of this risk and is considered safe 

with respect to styrene.

    (48) Tetrachloroethylene. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

tetrachloroethylene is a health concern at certain levels of exposure. 

This organic chemical has been a popular solvent, particularly for dry 

cleaning. It generally gets into drinking water by improper waste 

disposal. This chemical has been shown to cause cancer in laboratory 

animals such as rats and mice when the animals are exposed at high 

levels over their lifetimes. Chemicals that cause cancer in laboratory 

animals also may increase the risk of cancer in humans who are exposed 

over long periods of time. EPA has set the drinking water standard for 

tetrachloroethylene at 0.005 part per million (ppm) to reduce the risk 

of cancer or other adverse health effects which have been observed in 

laboratory animals. Drinking water that meets this standard is 

associated with little to none of this risk and is considered safe with 

respect to tetrachloroethylene.

    (49) Toluene. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that toluene is a 

health concern at certain levels of exposure. This organic chemical is 

used as a solvent and in the manufacture of gasoline for airplanes. It 

generally gets into water by improper waste disposal or leaking 

underground storage tanks. This chemical has been shown to damage the 

kidney, nervous system, and circulatory system of laboratory animals 

such as rats and mice exposed to high levels during their lifetimes. 

Some industrial workers who were exposed to relatively large amounts of 

this chemical during working careers



[[Page 407]]



also suffered damage to the liver, kidney and nervous system. EPA has 

set the drinking water standard for toluene at 1 part per million (ppm) 

to protect against the risk of adverse health effects. Drinking water 

that meets the EPA standard is associated with little to none of this 

risk and is considered safe with respect to toluene.

    (50) Toxaphene. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that toxaphene is 

a health concern at certain levels of exposure. This organic chemical 

was once a pesticide widely used on cotton, corn, soybeans, pineapples 

and other crops. When soil and climatic conditions are favorable, 

toxaphene may get into drinking water by runoff into surface water or by 

leaching into ground water. This chemical has been shown to cause cancer 

in laboratory animals such as rats and mice when the animals are exposed 

at high levels over their lifetimes. Chemicals that cause cancer in 

laboratory animals also may increase the risk of cancer in humans who 

are exposed over long periods of time. EPA has set the drinking water 

standard for toxaphene at 0.003 part per million (ppm) to reduce the 

risk of cancer or other adverse health effects which have been observed 

in laboratory animals. Drinking water that meets this standard is 

associated with little to none of this risk and is considered safe with 

respect to toxaphene.

    (51) 2,4,5-TP. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that 2,4,5-TP is 

a health concern at certain levels of exposure. This organic chemical is 

used as a herbicide. When soil and climatic conditions are favorable, 

2,4,5-TP may get into drinking water by runoff into surface water or by 

leaching into ground water. This chemical has been shown to damage the 

liver and kidney of laboratory animals such as rats and dogs exposed to 

high levels during their lifetimes. Some industrial workers who were 

exposed to relatively large amounts of this chemical during working 

careers also suffered damage to the nervous system. EPA has set the 

drinking water standard for 2,4,5-TP at 0.05 part per million (ppm) to 

protect against the risk of these adverse health effects. Drinking water 

that meets the EPA standard is associated with little to none of this 

risk and is considered safe with respect to 2,4,5-TP.

    (52) Xylenes. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that xylene is a 

health concern at certain levels of exposure. This organic chemical is 

used in the manufacture of gasoline for airplanes and as a solvent for 

pesticides, and as a cleaner and degreaser of metals. It usually gets 

into water by improper waste disposal. This chemical has been shown to 

damage the liver, kidney and nervous system of laboratory animals such 

as rats and dogs exposed to high levels during their lifetimes. Some 

humans who were exposed to relatively large amounts of this chemical 

also suffered damage to the nervous system. EPA has set the drinking 

water standard for xylene at 10 parts per million (ppm) to protect 

against the risk of these adverse health effects. Drinking water that 

meets the EPA standard is associated with little to none of this risk 

and is considered safe with respect to xylene.

    (53) Antimony. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that antimony is 

a health concern at certain levels of exposure. This inorganic chemical 

occurs naturally in soils, ground water and surface waters and is often 

used in the flame retardant industry. It is also used in ceramics, 

glass, batteries, fireworks and explosives. It may get into drinking 

water through natural weathering of rock, industrial production, 

municipal waste disposal or manufacturing processes. This chemical has 

been shown to decrease longevity, and altered blood levels of 

cholesterol and glucose in laboratory animals such as rats exposed to 

high levels during their lifetimes. EPA has set the drinking water 

standard for antimony at 0.006 parts per million (ppm) to protect 

against the risk of these adverse health effects. Drinking water which 

meets the EPA standard is associated with little to none of this risk 

and should be considered safe with respect to antimony.



[[Page 408]]



    (54) Beryllium. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that beryllium is 

a health concern at certain levels of exposure. This inorganic metal 

occurs naturally in soils, ground water and surface waters and is often 

used in electrical equipment and electrical components. It generally 

gets into water from runoff from mining operations, discharge from 

processing plants and improper waste disposal. Beryllium compounds have 

been associated with damage to the bones and lungs and induction of 

cancer in laboratory animals such as rats and mice when the animals are 

exposed at high levels over their lifetimes. There is limited evidence 

to suggest that beryllium may pose a cancer risk via drinking water 

exposure. Therefore, EPA based the health assessment on noncancer 

effects with an extra uncertainty factor to account for possible 

carcinogenicity. Chemicals that cause cancer in laboratory animals also 

may increase the risk of cancer in humans who are exposed over long 

periods of time. EPA has set the drinking water standard for beryllium 

at 0.004 part per million (ppm) to protect against the risk of these 

adverse health effects. Drinking water which meets the EPA standard is 

associated with little to none of this risk and should be considered 

safe with respect to beryllium.

    (55) Cyanide. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that cyanide is a 

health concern at certain levels of exposure. This inorganic chemical is 

used in electroplating, steel processing, plastics, synthetic fabrics 

and fertilizer products. It usually gets into water as a result of 

improper waste disposal. This chemical has been shown to damage the 

spleen, brain and liver of humans fatally poisoned with cyanide. EPA has 

set the drinking water standard for cyanide at 0.2 parts per million 

(ppm) to protect against the risk of these adverse health effects. 

Drinking water which meets the EPA standard is associated with little to 

none of this risk and should be considered safe with respect to cyanide.

    (56) [Reserved]

    (57) Thallium. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that thallium is 

a health concern at certain high levels of exposure. This inorganic 

metal is found naturally in soils and is used in electronics, 

pharmaceuticals, and the manufacture of glass and alloys. This chemical 

has been shown to damage the kidney, liver, brain and intestines of 

laboratory animals when the animals are exposed at high levels over 

their lifetimes. EPA has set the drinking water standard for thallium at 

0.002 parts per million (ppm) to protect against the risk of these 

adverse health effects. Drinking water which meets the EPA standard is 

associated with little to none of this risk and should be considered 

safe with respect to thallium.

    (58) Benzo[a]pyrene. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

benzo[a]pyrene is a health concern at certain levels of exposure. 

Cigarette smoke and charbroiled meats are common source of general 

exposure. The major source of benzo[a]pyrene in drinking water is the 

leaching from coal tar lining and sealants in water storage tanks. This 

chemical has been shown to cause cancer in animals such as rats and mice 

when the animals are exposed at high levels. EPA has set the drinking 

water standard for benzo[a]pyrene at 0.0002 parts per million (ppm) to 

protect against the risk of cancer. Drinking water which meets the EPA 

standard is associated with little to none of this risk and should be 

considered safe with respect to benzo[a]pyrene.

    (59) Dalapon. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that dalapon is a 

health concern at certain levels of exposure. This organic chemical is a 

widely used herbicide. It may get into drinking water after application 

to control grasses in crops, drainage ditches and along railroads. This 

chemical has been shown to cause damage to the kidney and liver in 

laboratory animals when the animals are exposed to high levels over 

their lifetimes. EPA has set the



[[Page 409]]



drinking water standard for dalapon at 0.2 parts per million (ppm) to 

protect against the risk of these adverse health effects. Drinking water 

which meets the EPA standard is associated with little to none of this 

risk and should be considered safe with respect to dalapon.

    (60) Dichloromethane. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

dichloromethane (methylene chloride) is a health concern at certain 

levels of exposure. This organic chemical is a widely used solvent. It 

is used in the manufacture of paint remover, as a metal degreaser and as 

an aerosol propellant. It generally gets into drinking water after 

improper discharge of waste disposal. This chemical has been shown to 

cause cancer in laboratory animals such as rats and mice when the 

animals are exposed at high levels over their lifetimes. Chemicals that 

cause cancer in laboratory animals also may increase the risk of cancer 

in humans who are exposed over long periods of time. EPA has set the 

drinking water standard for dichloromethane at 0.005 parts per million 

(ppm) to reduce the risk of cancer or other adverse health effects which 

have been observed in laboratory animals. Drinking water which meets 

this standard is associated with little to none of this risk and should 

be considered safe with respect to dichloromethane.

    (61) Di (2-ethylhexyl)adipate. The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

that di(2-ethylhexyl)adipate is a health concern at certain levels of 

exposure. Di(2-ethylhexyl)adipate is a widely used plasticizer in a 

variety of products, including synthetic rubber, food packaging 

materials and cosmetics. It may get into drinking water after improper 

waste disposal. This chemical has been shown to damage liver and testes 

in laboratory animals such as rats and mice exposed to high levels. EPA 

has set the drinking water standard for di(2-ethylhexyl)adipate at 0.4 

parts per million (ppm) to protect against the risk of adverse health 

effects. Drinking water which meets the EPA standards is associated with 

little to none of this risk and should be considered safe with respect 

to di(2-ethylhexyl)adipate.

    (62) Di(2-ethylhexyl)phthalate. The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

that di(2-ethylhexyl)phthalate is a health concern at certain levels of 

exposure. Di(2-ethylhexyl)phthalate is a widely used plasticizer, which 

is primarily used in the production of polyvinyl chloride (PVC) resins. 

It may get into drinking water after improper waste disposal. This 

chemical has been shown to cause cancer in laboratory animals such as 

rats and mice exposed to high levels over their lifetimes. EPA has set 

the drinking water standard for di(2-ethylhexyl)phthalate at 0.006 parts 

per million (ppm) to reduce the risk of cancer or other adverse health 

effects which have been observed in laboratory animals. Drinking water 

which meets the EPA standard is associated with little to none of this 

risk and should be considered safe with respect to di(2-

ethylhexyl)phthalate.

    (63) Dinoseb. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that dinoseb is a 

health concern at certain levels of exposure. Dinoseb is a widely used 

pesticide and generally gets into drinking water after application on 

orchards, vineyards and other crops. This chemical has been shown to 

damage the thyroid and reproductive organs in laboratory animals such as 

rats exposed to high levels. EPA has set the drinking water standard for 

dinoseb at 0.007 parts per million (ppm) to protect against the risk of 

adverse health effects. Drinking water which meets the EPA standard is 

associated with little to none of this risk and should be considered 

safe with respect to dinoseb.

    (64) Diquat. The United States Environmental Protection Agency (EPA) 

sets drinking water standards and has determined that diquat is a health 

concern at certain levels of exposure. This organic chemical is a 

herbicide used to control terrestrial and aquatic weeds. It may get into 

drinking water by runoff into surface water. This chemical has been 

shown to damage the liver, kidney and gastrointestinal tract and



[[Page 410]]



causes cataract formation in laboratory animals such as dogs and rats 

exposed at high levels over their lifetimes. EPA has set the drinking 

water standard for diquat at 0.02 parts per million (ppm) to protect 

against the risk of these adverse health effects. Drinking water which 

meets the EPA standard is associated with little to none of this risk 

and should be considered safe with respect to diquat.

    (65) Endothall. The United States Environmental Protection Agency 

(EPA) has determined that endothall is a health concern at certain 

levels of exposure. This organic chemical is a herbicide used to control 

terrestrial and aquatic weeds. It may get into water by runoff into 

surface water. This chemical has been shown to damage the liver, kidney, 

gastrointestinal tract and reproductive system of laboratory animals 

such as rats and mice exposed at high levels over their lifetimes. EPA 

has set the drinking water standard for endothall at 0.1 parts per 

million (ppm) to protect against the risk of these adverse health 

effects. Drinking water which meets the EPA standard is associated with 

little to none of this risk and should be considered safe with respect 

to endothall.

    (66) Endrin. The United States Environmental Protection Agency (EPA) 

sets drinking water standards and has determined that endrin is a health 

concern at certain levels of exposure. This organic chemical is a 

pesticide no longer registered for use in the United States. However, 

this chemical is persistent in treated soils and accumulates in 

sediments and aquatic and terrestrial biota. This chemical has been 

shown to cause damage to the liver, kidney and heart in laboratory 

animals such as rats and mice when the animals are exposed at high 

levels over their lifetimes. EPA has set the drinking water standard for 

endrin at 0.002 parts per million (ppm) to protect against the risk of 

these adverse health effects which have been observed in laboratory 

animals. Drinking water that meets the EPA standard is associated with 

little to none of this risk and should be considered safe with respect 

to endrin.

    (67) Glyphosate. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that glyphosate 

is a health concern at certain levels of exposure. This organic chemical 

is a herbicide used to control grasses and weeds. It may get into 

drinking water by runoff into surface water. This chemical has been 

shown to cause damage to the liver and kidneys in laboratory animals 

such as rats and mice when the animals are exposed at high levels over 

their lifetimes. EPA has set the drinking water standard for glyphosate 

at 0.7 parts per million (ppm) to protect against the risk of these 

adverse health effects. Drinking water which meets the EPA standard is 

associated with little to none of this risk and should be considered 

safe with respect to glyphosate.

    (68) Hexachlorobenzene. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

hexachlorobenzene is a health concern at certain levels of exposure. 

This organic chemical is produced as an impurity in the manufacture of 

certain solvents and pesticides. This chemical has been shown to cause 

cancer in laboratory animals such as rats and mice when the animals are 

exposed to high levels during their lifetimes. Chemicals that cause 

cancer in laboratory animals also may increase the risk of cancer in 

humans who are exposed over long periods of time. EPA has set the 

drinking water standard for hexachlorobenzene at 0.001 parts per million 

(ppm) to protect against the risk of cancer and other adverse health 

effects. Drinking water which meets the EPA standard is associated with 

little to none of this risk and should be considered safe with respect 

to hexachlorobenzene.

    (69) Hexachlorocyclopentadiene. The United States Environmental 

Protection Agency (EPA) establishes drinking water standards and has 

determined that hexachlorocyclopentadiene is a health concern at certain 

levels of exposure. This organic chemical is used as an intermediate in 

the manufacture of pesticides and flame retardants. It may get into 

water by discharge from production facilities. This chemical has been 

shown to damage the kidney and the stomach of laboratory animals



[[Page 411]]



when exposed at high levels over their lifetimes. EPA has set the 

drinking water standard for hexachlorocyclopentadiene at 0.05 parts per 

million (ppm) to protect against the risk of these adverse health 

effects. Drinking water which meets the EPA standard is associated with 

little to none of this risk and should be considered safe with respect 

to hexachlorocyclopentadiene.

    (70) Oxamyl. The United States Environmental Protection Agency (EPA) 

establishes drinking water standards and has determined that oxamyl is a 

health concern at certain levels of exposure. This organic chemical is 

used as a pesticide for the control of insects and other pests. It may 

get into drinking water by runoff into surface water or leaching into 

ground water. This chemical has been shown to damage the kidneys of 

laboratory animals such as rats when exposed at high levels over their 

lifetimes. EPA has set the drinking water standard for oxamyl at 0.2 

parts per million (ppm) to protect against the risk of these adverse 

health effects. Drinking water which meets the EPA standard is 

associated with little to none of this risk and should be considered 

safe with respect to oxamyl.

    (71) Picloram. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that picloram is 

a health concern at certain levels of exposure. This organic chemical is 

used as a pesticide for broadleaf weed control. It may get into drinking 

water by runoff into surface water or leaching into ground water as a 

result of pesticide application and improper waste disposal. This 

chemical has been shown to cause damage to the kidneys and liver in 

laboratory animals such as rats when the animals are exposed at high 

levels over their lifetimes. EPA has set the drinking water standard for 

picloram at 0.5 parts per million (ppm) to protect against the risk of 

these adverse health effects. Drinking water which meets the EPA 

standard is associated with little to none of this risk and should be 

considered safe with respect to picloram.

    (72) Simazine. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that simazine is 

a health concern at certain levels of exposure. This organic chemical is 

a herbicide used to control annual grasses and broadleaf weeds. It may 

leach into ground water or runs off into surface water after 

application. This chemical may cause cancer in laboratory animals such 

as rats and mice exposed at high levels during their lifetimes. 

Chemicals that cause cancer in laboratory animals also may increase the 

risk of cancer in humans who are exposed over long periods of time. EPA 

has set the drinking water standard for simazine at 0.004 parts per 

million (ppm) to reduce the risk of cancer or other adverse health 

effects. Drinking water which meets the EPA standard is associated with 

little to none of this risk and should be considered safe with respect 

to simazine.

    (73) 1,2,4-Trichlorobenzene. The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

that 1,2,4-trichlorobenzene is a health concern at certain levels of 

exposure. This organic chemical is used as a dye carrier and as a 

precursor in herbicide manufacture. It generally gets into drinking 

water by discharges from industrial activities. This chemical has been 

shown to cause damage to several organs, including the adrenal glands. 

EPA has set the drinking water standard for 1,2,4-trichlorobenzene at 

0.07 parts per million (ppm) to protect against the risk of these 

adverse health effects. Drinking water which meets the EPA standard is 

associated with little to none of this risk and should be considered 

safe with respect to 1,2,4-trichlorobenzene.

    (74) 1,1,2-Trichloroethane. The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

1,1,2-trichloroethane is a health concern at certain levels of exposure. 

This organic chemical is an intermediate in the production of 1,1-

dichloroethylene. It generally gets into water by industrial discharge 

of wastes. This chemical has been shown to damage the kidney and liver 

of laboratory animals such as rats exposed to high levels during their 

lifetimes. EPA has set the drinking water standard for 1,1,2-

trichloroethane at



[[Page 412]]



0.005 parts per million (ppm) to protect against the risk of these 

adverse health effects. Drinking water which meets the EPA standard is 

associated with little to none of this risk and should be considered 

safe with respect to 1,1,2-trichloroethane.

    (75) 2,3,7,8-TCDD (Dioxin). The United States Environmental 

Protection Agency (EPA) sets drinking water standards and has determined 

that dioxin is a health concern at certain levels of exposure. This 

organic chemical is an impurity in the production of some pesticides. It 

may get into drinking water by industrial discharge of wastes. This 

chemical has been shown to cause cancer in laboratory animals such as 

rats and mice when the animals are exposed at high levels over their 

lifetimes. Chemicals that cause cancer in laboratory animals also may 

increase the risk of cancer in humans who are exposed over long periods 

of time. EPA has set the drinking water standard for dioxin at 

0.00000003 parts per million (ppm) to reduce the risk of cancer or other 

adverse health effects which have been observed in laboratory animals. 

Drinking water which meets this standard is associated with little to 

none of this risk and should be considered safe with respect to dioxin.

    (76) Chlorine. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that chlorine is 

a health concern at certain levels of exposure. Chlorine is added to 

drinking water as a disinfectant to kill bacteria and other disease-

causing microorganisms and is also added to provide continuous 

disinfection throughout the distribution system. Disinfection is 

required for surface water systems. However, at high doses for extended 

periods of time, chlorine has been shown to affect blood and the liver 

in laboratory animals. EPA has set a drinking water standard for 

chlorine to protect against the risk of these adverse effects. Drinking 

water which meets this EPA standard is associated with little to none of 

this risk and should be considered safe with respect to chlorine.

    (77) Chloramines. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that chloramines 

are a health concern at certain levels of exposure. Chloramines are 

added to drinking water as a disinfectant to kill bacteria and other 

disease-causing microorganisms and are also added to provide continuous 

disinfection throughout the distribution system. Disinfection is 

required for surface water systems. However, at high doses for extended 

periods of time, chloramines have been shown to affect blood and the 

liver in laboratory animals. EPA has set a drinking water standard for 

chloramines to protect against the risk of these adverse effects. 

Drinking water which meets this EPA standard is associated with little 

to none of this risk and should be considered safe with respect to 

chloramines.

    (78) Chlorine dioxide. The United States Environmental Protection 

Agency (EPA) sets drinking water standards and has determined that 

chlorine dioxide is a health concern at certain levels of exposure. 

Chlorine dioxide is used in water treatment to kill bacteria and other 

disease-causing microorganisms and can be used to control tastes and 

odors. Disinfection is required for surface water systems. However, at 

high doses, chlorine dioxide-treated drinking water has been shown to 

affect blood in laboratory animals. Also, high levels of chlorine 

dioxide given to laboratory animals in drinking water have been shown to 

cause neurological effects on the developing nervous system. These 

neurodevelopmental effects may occur as a result of a short-term 

excessive chlorine dioxide exposure. To protect against such potentially 

harmful exposures, EPA requires chlorine dioxide monitoring at the 

treatment plant, where disinfection occurs, and at representative points 

in the distribution system serving water users. EPA has set a drinking 

water standard for chlorine dioxide to protect against the risk of these 

adverse effects.



    Note: In addition to the language in this introductory text of 

paragraph (e)(78), systems must include either the language in paragraph 

(e)(78)(i) or (e)(78)(ii) of this section. Systems with a violation at 

the treatment plant, but not in the distribution system, are required to 

use the language in paragraph (e)(78)(i) of this section and treat



[[Page 413]]



the violation as a nonacute violation. Systems with a violation in the 

distribution system are required to use the language in paragraph 

(e)(78)(ii) of this section and treat the violation as an acute 

violation.



    (i) The chlorine dioxide violations reported today are the result of 

exceedances at the treatment facility only, and do not include 

violations within the distribution system serving users of this water 

supply. Continued compliance with chlorine dioxide levels within the 

distribution system minimizes the potential risk of these violations to 

present consumers.

    (ii) The chlorine dioxide violations reported today include 

exceedances of the EPA standard within the distribution system serving 

water users. Violations of the chlorine dioxide standard within the 

distribution system may harm human health based on short-term exposures. 

Certain groups, including pregnant women, infants, and young children, 

may be especially susceptible to adverse effects of excessive exposure 

to chlorine dioxide-treated water. The purpose of this notice is to 

advise that such persons should consider reducing their risk of adverse 

effects from these chlorine dioxide violations by seeking alternate 

sources of water for human consumption until such exceedances are 

rectified. Local and State health authorities are the best sources for 

information concerning alternate drinking water.

    (79) Disinfection byproducts and treatment technique for DBPs. The 

United States Environmental Protection Agency (EPA) sets drinking water 

standards and requires the disinfection of drinking water. However, when 

used in the treatment of drinking water, disinfectants react with 

naturally-occurring organic and inorganic matter present in water to 

form chemicals called disinfection byproducts (DBPs). EPA has determined 

that a number of DBPs are a health concern at certain levels of 

exposure. Certain DBPs, including some trihalomethanes (THMs) and some 

haloacetic acids (HAAs), have been shown to cause cancer in laboratory 

animals. Other DBPs have been shown to affect the liver and the nervous 

system, and cause reproductive or developmental effects in laboratory 

animals. Exposure to certain DBPs may produce similar effects in people. 

EPA has set standards to limit exposure to THMs, HAAs, and other DBPs.

    (80) Bromate. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that bromate is a 

health concern at certain levels of exposure. Bromate is formed as a 

byproduct of ozone disinfection of drinking water. Ozone reacts with 

naturally occurring bromide in the water to form bromate. Bromate has 

been shown to produce cancer in rats. EPA has set a drinking water 

standard to limit exposure to bromate.

    (81) Chlorite. The United States Environmental Protection Agency 

(EPA) sets drinking water standards and has determined that chlorite is 

a health concern at certain levels of exposure. Chlorite is formed from 

the breakdown of chlorine dioxide, a drinking water disinfectant. 

Chlorite in drinking water has been shown to affect blood and the 

developing nervous system. EPA has set a drinking water standard for 

chlorite to protect against these effects. Drinking water which meets 

this standard is associated with little to none of these risks and 

should be considered safe with respect to chlorite.

    (f) Public notices for fluoride. Notice of violations of the maximum 

contaminant level for fluoride, notices of variances and exemptions from 

the maximum contaminant level for fluoride, and notices of failure to 

comply with variance and exemption schedules for the maximum contaminant 

level for fluoride shall consist of the public notice prescribed in 

Sec. 143.5(b), plus a description of any steps which the system is 

taking to come into compliance.

    (g) Public notification by the State. The State may give notice to 

the public required by this section on behalf of the owner or operator 

of the public water system if the State complies with the requirements 

of this section. However, the owner or operator of the public



[[Page 414]]



water system remains legally responsible for ensuring that the 

requirements of this section are met.



[52 FR 41546, Oct. 28, 1987, as amended at 54 FR 15188, Apr. 17, 1989; 

54 FR 27527, 27566, June 29, 1989; 55 FR 25064, June 19, 1990; 56 FR 

3587, Jan. 30, 1991; 56 FR 26548, June 7, 1991; 56 FR 30279, July 1, 

1991; 57 FR 31843, July 17, 1992; 59 FR 34323, July 1, 1994; 60 FR 

33932, June 29, 1995; 63 FR 69464, 69515, Dec. 16, 1998; 65 FR 26022, 

May 4, 2000]