National Drinking Water Database

• Read the Research
• Get a Water Filter
• Tips for Safe Water
• FAQs
• EWG Needs Your Help. As little as $5 can help.

National Drinking Water Database - Chemical Contaminants

Combined Uranium (mg/L)

Status: Regulated - EPA has established a maximum legal limit in tapwater for this contaminant.

Uranium is a radioactive element commonly found in most rocks; processed uranium ore is used for power generation and weapons manufacture. [read more]

Uranium Uranium is a radioactive heavy metal used in nuclear power plants and nuclear weapons. Uranium is a known human carcinogen. It has been observed to cause lung cancer in miners, and bone cancer and leukemia in workers and animals exposed to the substance (Hazardous Substances Data Bank (HSDB) 2003h). In addition to nuclear applications, uranium is also used to make helicopters, airplanes, army tanks, bullets and missiles. Small amounts are used to make pottery glazes and photographic chemicals. Since uranium is often found in naturally occurring phosphorus, phosphorus fertilizers and pesticides often have uranium impurities in them (Agency for Toxic Substances and Disease Registry (ATSDR) 1999c). A drinking water contaminant fact sheet written by EPA notes that exposure to uranium in drinking water above the maximum contaminant level (MCL) of 30 parts per billion (ppb) may damage the kidney and cause cancer (U.S. Environmental Protection Agency (USEPA) 2009b). Renal (kidney) problems are a hallmark of uranium toxicity; these effects develop early on following uranium exposure (Thun 1985).

	Detected	Found above health guidelines	Found above legal limit
States	28	28	20
Water utilities	2,830	2,830	192
People Served	24,329,141	24,329,141	715,090

Health Concerns for Combined Uranium (mg/L):

• Cancer
• Persistence and bioaccumulation
• Occupational hazards
• Organ system toxicity (non-reproductive)
• Ecotoxicology

Combined Uranium (mg/L) Exposure by State

Water utilities in 28 states have reported detecting Combined Uranium (mg/L) in treated tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies.

State	Water Suppliers with Combined Uranium (mg/L) contamination		Water suppliers reporting Combined Uranium (mg/L) above health-based limits
	Systems	Population	Systems	Population
New Jersey	500	7,323,364	500	7,323,364
California	157	6,740,595	157	6,740,595
Texas	143	2,903,621	143	2,903,621
Nevada	70	1,905,680	70	1,905,680
New Mexico	236	1,200,918	236	1,200,918
Connecticut	415	972,301	415	972,301
Nebraska	105	844,557	105	844,557
Oklahoma	52	811,370	52	811,370
Wisconsin	127	266,647	127	266,647
Arizona	2	266,000	2	266,000
New Hampshire	409	261,873	409	261,873
Massachusetts	26	152,950	26	152,950
Montana	123	122,577	123	122,577
New York	99	80,057	99	80,057
Alaska	145	78,759	145	78,759
Oregon	36	70,843	36	70,843
Missouri	21	66,031	21	66,031
North Dakota	16	63,566	16	63,566
Arkansas	28	37,071	28	37,071
Virginia	19	31,647	19	31,647
Illinois	8	31,524	8	31,524
Colorado	1	29,500	1	29,500
Vermont	43	27,669	43	27,669
Idaho	16	17,629	16	17,629
Wyoming	14	16,935	14	16,935
Iowa	4	3,718	4	3,718
Maine	14	1,709	14	1,709
Rhode Island	1	30	1	30
Total	2,830	24,329,141	2,830	24,329,141

The Most Polluted Communities

2,830 water utilities reported detecting Combined Uranium (mg/L) in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average Combined Uranium (mg/L) level

Rank	System	Population Served	Positive test results of total reported tests	Average Level (Range)
1	Sandy Lane Village Condominium Assn Brookfield, CT	318	4 of 4	76.58 ppb (65.34 to 84.72 ppb)
2	Candlewood Lake Condominium Assn., Inc. Danbury, CT	196	7 of 7	75.31 ppb (63.68 to 89.49 ppb)
3	Acre Lane, Inc. Ridgefield, CT	56	9 of 9	75.21 ppb (62.15 to 85.59 ppb)
4	Village of Beemer Beemer, NE	700	1 of 1	72.1 ppb (72.1 ppb)
5	Utility Development & Research Riviera, TX	630	7 of 7	71.81 ppb (65.8 to 81.6 ppb)
6	Valley Estates Water and Sewer Associati Espanola, NM	185	1 of 1	70 ppb (70 ppb)
7	Nichols Trailer Park Shelburne, ME	75	4 of 4	66.73 ppb (49 to 76.39 ppb)
8	Rio Brazos Water System TX	81	8 of 8	66.19 ppb (49.8 to 84.1 ppb)
9	Kern County Water Agency Bakersfield, CA	0	1 of 1	64.1 ppb (64.1 ppb)
10	Md#07 Marina View Heights Bass Lake, CA	200	2 of 2	62.5 ppb (40 to 85 ppb)

Health Based Limits for Combined Uranium (mg/L)

Standard	Description	Level
Maximum Contaminant Limit Goal (MCLG)	A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.	0 ppb
California Public Health Goals	Defined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.	0.5 ppb
Drinking Water Equivalent Level	A lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.	20 ppb
Maximum Contaminant Limit (MCL)	The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.	30 ppb

Testing Summary for Combined Uranium (mg/L)

Are tests routinely required for Combined Uranium (mg/L) by federal law?	Yes
Water suppliers reporting tests for Combined Uranium (mg/L) (2004-2009):	4,414 of 47,576
Average testing rate for water supplier reporting tests (2004-2009):	0.6 per year

Violation Summary for Combined Uranium (mg/L)

Data from the U.S. Environmental Protection Agency includes the following violations of federal standards for Combined Uranium (mg/L) since 2004

Maximum Contaminant Level Exceedance Violations	1,220
Monitoring Violations	9,073
Reporting Violations	0

Cancer

Type of concern:	Reference:
Known human carcinogen	Amer Conf of Gov't Industrial Hygienists - Carcinogens
Cancer - strong evidence	CHE Toxicant and Disease Database

Persistence and bioaccumulation

Type of concern:	Reference:
Not suspected to be bioaccumulative	Environment Canada Domestic Substance List

Occupational hazards

Type of concern:	Reference:
Allowed workplace exposures restricted to very low doses	European Union - Classification & Labelling
Allowed workplace exposures restricted to very low doses	National Library of Medicine HazMap
Allowed workplace exposures restricted to very low doses	RTECS®- TLV/BEI,2007
Allowed workplace exposures restricted to low doses	National Library of Medicine HazMap
Strong evidence of occupational hazards	European Union - Classification & Labelling
Single case study detailing occupational hazards	Frazier , L, 1998

Organ system toxicity (non-reproductive)

Type of concern:	Reference:
Possible human renal toxicant	CHE Toxicant and Disease Database
Classified as very toxic or harmful	European Union - Classification & Labelling
Limited evidence of renal toxicity	CHE Toxicant and Disease Database
Limited evidence of respiratory toxicity	US EPA, Air Risk Information Support Center, 1990
Limited evidence of kidney toxicity	Agency for Toxic Substances and Disease Registry, 2004
One or more animal studies show broad systemic effects at moderate doses (low dose studies may be unavailable for this ingredient)	RTECS®- Gigiena i Sanitariya 1972
Classified as not expected to be potentially toxic or harmful	Environment Canada Domestic Substance List
Classified as a low human health priority	Environment Canada Domestic Substance List

Ecotoxicology

Type of concern:	Reference:
Wildlife and environmental toxicity	European Union - Classification & Labelling
Not suspected to be an environmental toxin	Environment Canada Domestic Substance List

Government, industry, academic studies and classifications

government/industry list/academic study	appears on list as	classification(s)
European Union - Classification & Labelling	URANIUM	•Very toxic •Very toxic by inhalation and if swallowed •Danger of cumulative effects •May cause long-term adverse effects in the aquatic environment
European Union - Classification & Labelling	URANIUM COMPOUNDS	•Very toxic •Very toxic by inhalation and if swallowed •Danger of cumulative effects •Dangerous for the environment •Toxic to aquatic organisms
Amer Conf of Gov't Industrial Hygienists - Carcinogens	URANIUM (AS U)	•Confirmed human carcinogen (ACGIH classification A1)
Association of Occupational and Environmental Clinics	URANIUM	• o
Environment Canada Domestic Substance List	URANIUM	•This chemical was deemed a low human health priority and was NOT flagged by CEPA for further attention. The chemical was flagged for suspected persistence.
National Library of Medicine HazMap	URANIUM AND COMPOUNDS	•Nephrotoxin: Yes; •PEL (OSHA) - Permissible exposure limit (OSHA): 0.05 mg/m3, as U; •STEL (ACGIH) - Short-term exposure limits (ACGIH): 0.6 mg/m3, as U; •Bioaccumulates: Yes; •TLV (ACGIH) - Threshold limit value (ACGIH): 0.2 mg/m3, as U; •Flammability (NFPA) - NFPA flammability code: 0 = will not burn; 1 = must be preheated; 2 = high ambient temp required; 3 = may ignite at ambient temp; 4 = burn readily: 4: burns readily; •IDLH (NIOSH) - Immediately Dangerous to Life or Health: 10 mg/m3, as U;
Agency for Toxic Substances and Disease Registry, 2004	URANIUM	•Kidney toxicity hazards: suspected
US EPA, Air Risk Information Support Center	URANIUM	•Cardiovascular or blood toxicity hazards: suspected
US EPA, Air Risk Information Support Center, 1990	URANIUM	•Respiratory toxicity hazards: suspected
Frazier , L, 1998	URANIUM	•Reproductive toxicity hazards: suspected
Agency for Toxic Substances and Disease Registry, 2004	URANIUM (SOLUBLE SALTS)	•Kidney toxicity hazards: suspected
RTECS®- TLV/BEI,2007	URANIUM	• occupationally related - ACGIH TLV (human TWA)
RTECS®- Gigiena i Sanitariya 1972	URANIUM	• broad systemic - Broad systemic toxicity (rat LD50)

references

government/industry list/academic study	reference
European Union - Classification & Labelling	CPS&Q (Consumer Products Safety & Quality) formely known as ECB (European Chemicals Bureau). 2008. Classification and Labelling: Chemicals: Annex VI of Directive 67/548/EEC through the 31st ATP.
Amer Conf of Gov't Industrial Hygienists - Carcinogens	ACGIH (American Conference of Governmental Industrial Hygienists) 2008. ACGIH cancer classification system. www.acgih.org.
Association of Occupational and Environmental Clinics	AOEC (Association of Occupational and Environmental Clinics). 2009. AEOC exposures codes and asthmagen designation.
Environment Canada Domestic Substance List	EC (Environment Canada). 2008. Domestic Substances List Categorization. Canadian Environmental Protection Act (CEPA) Environmental Registry.
National Library of Medicine HazMap	NLM (National Library of Medicine). 2006. HazMap — Occupational Exposure to Hazardous Agents.
Scorecard.org Toxicity Information	Agency for Toxic Substances and Disease Registry. Minimal risk Levels for Hazardous Substances. January 2004. http://www.atsdr.cdc.gov/mrls.html, A Relational Database of Hazardous Chemicals and Occupational Diseases. Browse Haz-Map by Adverse Effects http://hazmap.nlm.nih.gov/hazmapadv.html, Landrigan, P.J., Goyer, R.A. Clarkson, T.W., Sandler, D.P., Smith, J.H., Thun, M.J., and R. Wedeen. The Work-Relatedness of Renal Disease. Archives of Environmental Health. 39(3): 225-230. 1984. (Table 2: Estimated Numbers of Workers in the United States with Potential Occupational Exposures to Known or Suspect Nephrotoxins)., Merck & Co. The Merck Manual of Diagnosis and Therapy. TABLE 226-1. Common Nephrotoxic Agents http://www.merck.com/pubs/mmanual/tables/226tb1.htm
Scorecard.org Toxicity Information	US EPA, Air Risk Information Support Center. Health Effects Notebook for Hazardous Air Pollutants. http://www.epa.gov/ttnatw01/hlthef/hapindex.html
Scorecard.org Toxicity Information	US EPA, Air Risk Information Support Center. Health Effects Notebook for Hazardous Air Pollutants. http://www.epa.gov/ttnatw01/hlthef/hapindex.html, Nemery, B. Metal Toxicity and the Respiratory Tract. European Respiratory Journal. 3(2): 202-219. 1990.(Table 1: Summary of pulmonary toxicity of metals).
Scorecard.org Toxicity Information	Frazier , L. and M. L. Hage (eds.). Reproductive Hazards of the Workplace, Wiley Europe, 1998. Table 10 (Partial List of Reproductive Toxicants) available at http://www.pharmacy.ohio-state.edu/homepage/safety/chemhygiene_table_repro.pdf.
Scorecard.org Toxicity Information	Agency for Toxic Substances and Disease Registry. Minimal risk Levels for Hazardous Substances. January 2004. http://www.atsdr.cdc.gov/mrls.html
RTECS®- TLV/BEI,2007	RTECS®- TLV/BEI,2007
RTECS®- Gigiena i Sanitariya 1972	RTECS®- Gigiena i Sanitariya. For English translation, see HYSAAV. (V/O Mezhdunarodnaya Kniga, 113095 Moscow, USSR) V.1- 1936- 37(10),27,1972

"RTECS®" is a United States trademark owned and licensed under authority of the U.S. Government, by and through MDL Information Systems, Inc.