# National Primary Drinking Water Regulations

Contaminant MCL or Potential health effects from Common sources of contaminant Public Health

TT 1 

## (mg/L) 2 

## long-term 3 

## exposure above the MCL in drinking water Goal (mg/L) 2



## OC Acrylamide TT 4 Nervous system or blood problems; Added to water during sewage/ zero

increased risk of cancer wastewater treatment



## OC Alachlor 0.002 Eye, liver, kidney or spleen problems; Runoff from herbicide zero anemia; increased risk of cancer used on row crops



## R Alpha/photon emitters 15 picocuries Increased risk of cancer Erosion of natural deposits of certain zero per Liter minerals that are radioactive and

(pCi/L) may emit a form of radiation known

as alpha radiation



## IOC Antimony 0.006 Increase	in	blood	cholesterol;	decrease Discharge	from	petroleum	refineries; 0.006

in	blood	sugar fire	retardants;	ceramics;	electronics;

solder



## IOC Arsenic 0.010 Skin damage or problems with circulatory Erosion of natural deposits; runoff 0

systems, and may have increased from orchards; runoff from glass &

risk of getting cancer electronics production wastes



## IOC Asbestos	(fibers	>10 7	million Increased	risk	of	developing	benign Decay	of	asbestos	cement	in	water 7	MFL

micrometers) fibers	per intestinal	polyps mains;	erosion	of	natural	deposits

Liter	(MFL)



## OC Atrazine 0.003 Cardiovascular system or reproductive Runoff from herbicide used on row 0.003

problems crops



## IOC Barium 2 Increase in blood pressure Discharge of drilling wastes; discharge 2

from	metal	refineries;	erosion

of natural deposits



## OC Benzene 0.005 Anemia; decrease in blood platelets; Discharge from factories; leaching zero

increased	risk	of	cancer from	gas	storage	tanks	and	landfills



## OC Benzo(a)pyrene 0.0002 Reproductive	difficulties;	increased	risk Leaching	from	linings	of	water	storage zero (PAHs) of cancer tanks and distribution lines



## IOC Beryllium 0.004 Intestinal	lesions Discharge	from	metal	refineries	and 0.004

coal-burning factories; discharge

from electrical, aerospace, and

defense industries



## R Beta photon emitters 4 millirems Increased risk of cancer Decay of natural and man-made zero

per year deposits of certain minerals that are

radioactive and may emit forms of

radiation known as photons and beta

radiation



## DBP Bromate 0.010 Increased risk of cancer Byproduct of drinking water disinfection zero



## IOC Cadmium 0.005 Kidney damage Corrosion of galvanized pipes; erosion 0.005

of natural deposits; discharge

from	metal	refineries;	runoff	from

waste batteries and paints



## OC Carbofuran 0.04 Problems with blood, nervous system, or Leaching of soil fumigant used on rice 0.04

reproductive system and alfalfa



## OC Carbon tetrachloride 0.005 Liver problems; increased risk of cancer Discharge from chemical plants and zero

other industrial activities



## D Chloramines (as Cl ) MRDL=4.0 1 Eye/nose	irritation;	stomach	discomfort; Water	additive	used	to	control MRDLG=4 1

2 anemia microbes



## OC Chlordane 0.002 Liver or nervous system problems; Residue of banned termiticide zero

increased risk of cancer



## D Chlorine (as Cl ) MRDL=4.0 1 Eye/nose	irritation;	stomach	discomfort Water	additive	used	to	control MRDLG=4 1

2 microbes



## D Chlorine	dioxide MRDL=0.8 1 Anemia;	infants,	young	children,	and	fetuses	of Water	additive	used	to	control MRDLG=0.8 1

(as ClO ) pregnant women: nervous system effects microbes

2



## DBP Chlorite 1.0 Anemia;	infants,	young	children,	and	fetuses	of Byproduct	of	drinking	water 0.8

pregnant women: nervous system effects disinfection



## OC Chlorobenzene 0.1 Liver or kidney problems Discharge from chemical and agricultural 0.1

chemical factories



## IOC Chromium (total) 0.1 Allergic dermatitis Discharge from steel and pulp mills; 0.1

erosion of natural deposits



## IOC Copper TT 5 ; Short-term	exposure:	Gastrointestinal Corrosion	of	household	plumbing 1.3

Action distress. Long-term exposure: Liver or systems; erosion of natural deposits

Level	= kidney	damage.	People	with	Wilson’s

1.3 Disease should consult their personal

doctor if the amount of copper in their

water exceeds the action level



## M Cryptosporidium TT 7 Short-term	exposure:	Gastrointestinal	illness Human	and	animal	fecal	waste zero (e.g., diarrhea, vomiting, cramps)

LEGEND

D 

### Disinfectant IOC 

### Inorganic Chemical OC 

### Organic Chemical

DBP 

### Disinfection Byproduct M 

### Microorganism R 

### Radionuclides

## Contaminant MCL or

TT 1 

## (mg/L) 2 

## Potential health effects from

long-term 3 

## exposure above the MCL Common sources of contaminant

in drinking water Public Health

Goal (mg/L) 2



## IOC

OC Cyanide

(as free cyanide)

2,4-D 0.2

0.07 Nerve damage or thyroid problems

Kidney,	liver,	or	adrenal	gland	problems Discharge from steel/metal factories;

discharge from plastic and fertilizer

factories

Runoff	from	herbicide	used	on	row 0.2

0.07

crops



## OC

OC Dalapon

1,2-Dibromo-3-

chloropropane

(DBCP) 0.2

0.0002 Minor	kidney	changes

Reproductive	difficulties;	increased	risk

of cancer Runoff	from	herbicide	used	on	rights

of way

Runoff/leaching	from	soil	fumigant

used on soybeans, cotton, pineapples,

and orchards 0.2

zero



## OC o-Dichlorobenzene 0.6 Liver, kidney, or circulatory system

problems Discharge from industrial chemical

factories 0.6



## OC p-Dichlorobenzene 0.075 Anemia;	liver,	kidney	or	spleen	damage;

changes in blood Discharge	from	industrial	chemical

factories 0.075



## OC 1,2-Dichloroethane 0.005 Increased risk of cancer Discharge from industrial chemical

factories zero



## OC

OC

OC 1,1-Dichloroethylene

cis-1,2-Dichloroethylene

trans-1,2­

Dichloroethylene 0.007

0.07

0.1 Liver	problems

Liver	problems

Liver problems Discharge	from	industrial	chemical

factories

Discharge	from	industrial	chemical

factories

Discharge from industrial chemical

factories 0.007

0.07

0.1



## OC Dichloromethane 0.005 Liver problems; increased risk of cancer Discharge from drug and chemical

factories zero



## OC

OC 1,2-Dichloropropane

Di(2-ethylhexyl) adipate 0.005

0.4 Increased risk of cancer

Weight loss, liver problems, or possible

reproductive	difficulties Discharge from industrial chemical

factories

Discharge from chemical factories zero

0.4



## OC Di(2-ethylhexyl)

phthalate 0.006 Reproductive	difficulties;	liver	problems;

increased risk of cancer Discharge	from	rubber	and	chemical

factories zero



## OC

OC

OC Dinoseb

Dioxin	(2,3,7,8-TCDD)

Diquat 0.007

0.00000003

0.02 Reproductive	difficulties

Reproductive	difficulties;	increased	risk

of cancer

Cataracts Runoff	from	herbicide	used	on	soybeans

and vegetables

Emissions	from	waste	incineration

and other combustion; discharge

from chemical factories

Runoff from herbicide use 0.007

zero

0.02



## OC Endothall 0.1 Stomach and intestinal problems Runoff from herbicide use 0.1



## OC Endrin 0.002 Liver problems Residue of banned insecticide 0.002



## OC Epichlorohydrin TT 4 Increased cancer risk; stomach problems Discharge from industrial chemical

factories; an impurity of some water

treatment chemicals zero



## OC Ethylbenzene 0.7 Liver	or	kidney	problems Discharge	from	petroleum	refineries 0.7



## OC

M Ethylene	dibromide

Fecal	coliform	and

E. coli 0.00005

MCL 6 Problems	with	liver,	stomach,	reproductive Discharge	from	petroleum	refineries

system, or kidneys; increased risk of cancer

Fecal	coliforms	and E. coli are bacteria whose Human and animal fecal waste

presence indicates that the water may be contaminated

with	human	or	animal	wastes.	Microbes	in	these	wastes zero

zero 6

may cause short term effects, such as diarrhea, cramps,

nausea, headaches, or other symptoms. They may pose a

special health risk for infants, young children, and people

with severely compromised immune systems.



## IOC

M

OC Fluoride

Giardia lamblia

Glyphosate 4.0

TT 7

0.7 Bone	disease	(pain	and	tenderness	of

the bones); children may get mottled

teeth

Short-term	exposure:	Gastrointestinal	illness

(e.g., diarrhea, vomiting, cramps)

Kidney	problems;	reproductive

difficulties Water	additive	which	promotes

strong teeth; erosion of natural

deposits; discharge from fertilizer

and aluminum factories

Human	and	animal	fecal	waste

Runoff	from	herbicide	use 4.0

zero

0.7



## DBP

OC

OC

M Haloacetic acids

(HAA5)

Heptachlor

Heptachlor epoxide

Heterotrophic plate

count (HPC) 0.060

0.0004

0.0002

TT 7 Increased risk of cancer

Liver damage; increased risk of cancer

Liver damage; increased risk of cancer

HPC has no health effects; it is an

analytic method used to measure the

variety of bacteria that are common in

water. The lower the concentration of Byproduct of drinking water

disinfection

Residue of banned termiticide

Breakdown of heptachlor

HPC measures a range of bacteria

that are naturally present in the

environment n/a 9

zero

zero

n/a

bacteria in drinking water, the better

maintained the water system is.

LEGEND

D 

### Disinfectant IOC 

### Inorganic Chemical OC 

### Organic Chemical

DBP 

### Disinfection Byproduct M 

### Microorganism R 

### Radionuclides

## Contaminant MCL or Potential health effects from Common sources of contaminant Public Health

TT 1 

## (mg/L) 2 

## long-term 3 

## exposure above the MCL in drinking water Goal (mg/L) 2



## OC Hexachlorobenzene 0.001 Liver	or	kidney	problems;	reproductive Discharge	from	metal	refineries	and zero difficulties;	increased	risk	of	cancer agricultural	chemical	factories



## OC Hexachlorocyclopentadiene 0.05 Kidney or stomach problems Discharge from chemical factories 0.05



## IOC Lead TT5; Infants and children: Delays in physical or Corrosion of household plumbing zero

Action or mental development; children could systems; erosion of natural deposits

Level=0.015 show	slight	deficits	in	attention	span

and learning abilities; Adults: Kidney

problems; high blood pressure



## M Legionella TT7 Legionnaire’s	Disease,	a	type	of Found	naturally	in	water;	multiplies	in zero pneumonia heating systems



## OC Lindane 0.0002 Liver or kidney problems Runoff/leaching from insecticide used 0.0002

on cattle, lumber, gardens



## IOC Mercury	(inorganic) 0.002 Kidney	damage Erosion	of	natural	deposits;	discharge 0.002

from	refineries	and	factories;

runoff	from	landfills	and	croplands



## OC Methoxychlor 0.04 Reproductive	difficulties Runoff/leaching	from	insecticide	used 0.04

on fruits, vegetables, alfalfa, livestock



## IOC Nitrate (measured as 10 Infants below the age of six months who Runoff from fertilizer use; leaching 10

Nitrogen) drink water containing nitrate in excess from septic tanks, sewage; erosion of

of	the	MCL	could	become	seriously	ill natural	deposits

and, if untreated, may die. Symptoms

include shortness of breath and blue-baby

syndrome.



## IOC Nitrite (measured as 1 Infants below the age of six months who Runoff from fertilizer use; leaching 1

Nitrogen) drink water containing nitrite in excess from septic tanks, sewage; erosion of

of	the	MCL	could	become	seriously	ill natural	deposits

and, if untreated, may die. Symptoms

include shortness of breath and blue-baby

syndrome.



## OC Oxamyl (Vydate) 0.2 Slight nervous system effects Runoff/leaching from insecticide used 0.2

on apples, potatoes, and tomatoes



## OC Pentachlorophenol 0.001 Liver or kidney problems; increased Discharge from wood-preserving zero

cancer risk factories



## OC Picloram 0.5 Liver problems Herbicide runoff 0.5



## OC Polychlorinated	biphenyls 0.0005 Skin	changes;	thymus	gland	problems; Runoff	from	landfills;	discharge	of zero (PCBs) immune	deficiencies;	reproductive	or waste	chemicals

nervous	system	difficulties;	increased

risk of cancer



## R Radium 226 and 5 pCi/L Increased risk of cancer Erosion of natural deposits zero Radium	228	(combined)



## IOC Selenium 0.05 Hair	or	fingernail	loss;	numbness	in	fingers Discharge	from	petroleum	and	metal	refineries; 0.05

or toes; circulatory problems erosion of natural deposits; discharge

from mines



## OC Simazine 0.004 Problems with blood Herbicide runoff 0.004



## OC Styrene 0.1 Liver, kidney, or circulatory system problems Discharge from rubber and plastic 0.1

factories;	leaching	from	landfills



## OC Tetrachloroethylene 0.005 Liver problems; increased risk of cancer Discharge from factories and dry cleaners zero



## IOC Thallium 0.002 Hair loss; changes in blood; kidney, intestine, Leaching from ore-processing sites; 0.0005

or liver problems discharge from electronics, glass,

and drug factories



## OC Toluene 1 Nervous system, kidney, or liver problems Discharge from petroleum factories 1



## M Total Coliforms 5.0 Coliforms are bacteria that indicate that other, Naturally present in the environment zero

percent 8 potentially harmful bacteria may be present.

See fecal coliforms and E. coli



## DBP Total	Trihalomethanes 0.080 Liver,	kidney	or	central	nervous	system	problems; Byproduct	of	drinking	water	disinfection n/a 9

(TTHMs) increased	risk	of	cancer



## OC Toxaphene 0.003 Kidney, liver, or thyroid problems; Runoff/leaching from insecticide used zero

increased risk of cancer on cotton and cattle



## OC 2,4,5-TP (Silvex) 0.05 Liver problems Residue of banned herbicide 0.05



## OC 1,2,4-Trichlorobenzene 0.07 Changes	in	adrenal	glands Discharge	from	textile	finishing 0.07

factories



## OC 1,1,1-Trichloroethane 0.2 Liver, nervous system, or circulatory Discharge from metal degreasing 0.2

problems sites and other factories



## OC 1,1,2-Trichloroethane 0.005 Liver, kidney, or immune system Discharge from industrial chemical 0.003

problems factories



## OC Trichloroethylene 0.005 Liver problems; increased risk of cancer Discharge from metal degreasing zero

sites and other factories

LEGEND

D 

### Disinfectant IOC 

### Inorganic Chemical OC 

### Organic Chemical

DBP 

### Disinfection Byproduct M 

### Microorganism R 

### Radionuclides

## Contaminant MCL or

TT 1 

## (mg/L) 2 

## Potential health effects from

long-term 3 

## exposure above the MCL Common sources of contaminant

in drinking water Public Health

Goal (mg/L) 2



## M Turbidity TT 7 Turbidity is a measure of the cloudiness of water. Soil runoff n/a

It	is	used	to	indicate	water	quality	and	filtration

effectiveness (e.g., whether disease-causing organisms

are present). Higher turbidity levels are often associated

with higher levels of disease-causing microorganisms

such as viruses, parasites and some bacteria. These

organisms can cause short term symptoms such as

nausea, cramps, diarrhea, and associated headaches.



## R Uranium 30μg/L Increased risk of cancer, kidney toxicity Erosion of natural deposits zero



## OC Vinyl chloride 0.002 Increased risk of cancer Leaching from PVC pipes; discharge zero from plastic factories



## M Viruses (enteric) TT 7 Short-term	exposure:	Gastrointestinal	illness Human	and	animal	fecal	waste zero (e.g., diarrhea, vomiting, cramps)



## OC Xylenes (total) 10 Nervous system damage Discharge from petroleum factories; 10

discharge from chemical factories

LEGEND

D 

### Disinfectant IOC 

### Inorganic Chemical OC 

### Organic Chemical

DBP 

### Disinfection Byproduct M 

### Microorganism R 

### Radionuclides

# NOTES

1 Definitions

• Maximum	Contaminant	Level	Goal	(MCLG)—The	level	of	a	contaminant	in	drinking	water	below • Viruses:	99.99	percent	removal/inactivation

which	there	is	no	known	or	expected	risk	to	health.	MCLGs	allow	for	a	margin	of	safety	and	are • Legionella :	No	limit,	but	EPA	believes	that	if Giardia and	viruses	are	removed/inactivated	according

non-enforceable	public	health	goals. to	the	treatment	techniques	in	the	surface	water	treatment	rule, Legionella will	also	be	controlled.

• Maximum	Contaminant	Level	(MCL)—The	highest	level	of	a	contaminant	that	is	allowed	in • Turbidity:	For	systems	that	use	conventional	or	direct	filtration,	at	no	time	can	turbidity	(cloudiness	of

drinking	water.	MCLs	are	set	as	close	to	MCLGs	as	feasible	using	the	best	available	treatment water)	go	higher	than	1	nephelolometric	turbidity	unit	(NTU),	and	samples	for	turbidity	must	be

technology	and	taking	cost	into	consideration.	MCLs	are	enforceable	standards. less	than	or	equal	to	0.3	NTU	in	at	least	95	percent	of	the	samples	in	any	month.	Systems	that	use

• Maximum	Residual	Disinfectant	Level	Goal	(MRDLG)—The	level	of	a	drinking	water	disinfectant filtration	other	than	conventional	or	direct	filtration	must	follow	state	limits,	which	must	include	turbidity

below	which	there	is	no	known	or	expected	risk	to	health.	MRDLGs	do	not	reflect	the	benefits	of at	no	time	exceeding	5	NTU.

the	use	of	disinfectants	to	control	microbial	contaminants. • HPC:	No	more	than	500	bacterial	colonies	per	milliliter

• Maximum	Residual	Disinfectant	Level	(MRDL)—The	highest	level	of	a	disinfectant	allowed	in • Long	Term	1	Enhanced	Surface	Water	Treatment;	Surface	water	systems	or	ground	water	systems

drinking	water.	There	is	convincing	evidence	that	addition	of	a	disinfectant	is	necessary	for under	the	direct	influence	of	surface	water	serving	fewer	than	10,000	people	must	comply	with	the

control	of	microbial	contaminants. applicable	Long	Term	1	Enhanced	Surface	Water	Treatment	Rule	provisions	(e.g.	turbidity	standards,

• Treatment	Technique	(TT)—A	required	process	intended	to	reduce	the	level	of	a	contaminant	in individual	filter	monitoring, Cryptosporidium removal	requirements,	updated	watershed	control

drinking	water. requirements	for	unfiltered	systems).

2 Units	are	in	milligrams	per	liter	(mg/L)	unless	otherwise	noted.	Milligrams	per	liter	are	equivalent • Long	Term	2	Enhanced	Surface	Water	Treatment;	This	rule	applies	to	all	surface	water	systems

to	parts	per	million	(ppm). or	ground	water	systems	under	the	direct	influence	of	surface	water.	The	rule	targets	additional

3 Health	effects	are	from	long-term	exposure	unless	specified	as	short-term	exposure. Cryptosporidium treatment	requirements	for	higher	risk	systems	and	includes	provisions	to	reduce

4 Each	water	system	must	certify	annually,	in	writing,	to	the	state	(using	third-party	or	manufacturers risks	from	uncovered	finished	water	storages	facilities	and	to	ensure	that	the	systems	maintain	microbial

certification)	that	when	it	uses	acrylamide	and/or	epichlorohydrin	to	treat	water,	the	combination	(or protection	as	they	take	steps	to	reduce	the	formation	of	disinfection	byproducts.	(Monitoring

product)	of	dose	and	monomer	level	does	not	exceed	the	levels	specified,	as	follows:	Acrylamide start	dates	are	staggered	by	system	size.	The	largest	systems	(serving	at	least	100,000

=	0.05	percent	dosed	at	1	mg/L	(or	equivalent);	Epichlorohydrin	=	0.01	percent	dosed	at	20	mg/L people)	will	begin	monitoring	in	October	2006	and	the	smallest	systems	(serving	fewer	than

(or	equivalent). 10,000	people)	will	not	begin	monitoring	until	October	2008.	After	completing	monitoring	and

5 Lead	and	copper	are	regulated	by	a	Treatment	Technique	that	requires	systems	to	control	the determining	their	treatment	bin,	systems	generally	have	three	years	to	comply	with	any	additional

corrosiveness	of	their	water.	If	more	than	10	percent	of	tap	water	samples	exceed	the	action	level, treatment	requirements.)

water	systems	must	take	additional	steps.	For	copper,	the	action	level	is	1.3	mg/L,	and	for	lead	is • Filter	Backwash	Recycling:	The	Filter	Backwash	Recycling	Rule	requires	systems	that	recycle	to

0.015	mg/L. return	specific	recycle	flows	through	all	processes	of	the	system’s	existing	conventional	or	direct

6 A	routine	sample	that	is	fecal	coliform-positive	or E. coli -positive	triggers	repeat	samples--if	any filtration	system	or	at	an	alternate	location	approved	by	the	state.

repeat	sample	is	total	coliform-positive,	the	system	has	an	acute	MCL	violation.	A	routine	sample 8 No	more	than	5.0	percent	samples	total	coliform-positive	in	a	month.	(For	water	systems	that	collect

that	is	total	coliform-positive	and	fecal	coliform-negative	or E. coli -negative	triggers	repeat	samples--if fewer	than	40	routine	samples	per	month,	no	more	than	one	sample	can	be	total	coliform-positive

any	repeat	sample	is	fecal	coliform-positive	or E. coli -positive,	the	system	has	an	acute	MCL	violation. per	month.)	Every	sample	that	has	total	coliform	must	be	analyzed	for	either	fecal	coliforms	or

See	also	Total	Coliforms. E. coli .	If	two	consecutive	TC-positive	samples,	and	one	is	also	positive	for E. coli or	fecal	coliforms,

7 EPA’s	surface	water	treatment	rules	require	systems	using	surface	water	or	ground	water	under system	has	an	acute	MCL	violation.

the	direct	influence	of	surface	water	to	(1)	disinfect	their	water,	and	(2)	filter	their	water	or	meet 9 Although	there	is	no	collective	MCLG	for	this	contaminant	group,	there	are	individual	MCLGs	for

criteria	for	avoiding	filtration	so	that	the	following	contaminants	are	controlled	at	the	following	levels: some	of	the	individual	contaminants:

• Cryptosporidium :	99	percent	removal	for	systems	that	filter.	Unfiltered	systems	are	required	to • Haloacetic	acids:	dichloroacetic	acid	(zero);	trichloroacetic	acid	(0.3	mg/L)

include	Cryptosporidium	in	their	existing	watershed	control	provisions. • Trihalomethanes:	bromodichloromethane	(zero);	bromoform	(zero);	dibromochloromethane	(0.06	mg/L)

• Giardia	lamblia:	99.9	percent	removal/inactivation

# National Secondary Drinking

**Water Regulation**

National Secondary Drinking Water Regulations are non-enforceable guidelines regarding

contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary

standards to water systems but does not require systems to comply. However, some states

may choose to adopt them as enforceable standards.

Contaminant Secondary Maximum Contaminant Level

Aluminum 0.05 to 0.2 mg/L

Chloride 250 mg/L

Color 15 (color units)

Copper 1.0 mg/L

Corrosivity noncorrosive

Fluoride 2.0 mg/L

Foaming Agents 0.5 mg/L

Iron 0.3 mg/L

Manganese 0.05 mg/L

Odor 3 threshold odor number

pH 6.5-8.5

Silver 0.10 mg/L

Sulfate 250 mg/L

Total Dissolved Solids 500 mg/L

Zinc 5 mg/L 

# For More Information

EPA’s Safe Drinking Water Web site:

http://www.epa.gov/safewater/



# EPA’s Safe Drinking Water Hotline:

(800) 426-4791

To order additional posters or other

ground water and drinking water

publications, please contact the

National Service Center for

Environmental Publications at :

(800) 490-9198, or

email: nscep@bps-lmit.com.

EPA 816-F-09-004

May 2009