EWG INVESTIGATION

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EWG Statement, 03/10/2008

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WHAT'S IN YOUR WATER?

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NATIONAL SUMMARY

Quality Varies Across the U.S.

CONTAMINANTS DATABASE

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Credits

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Status: Unregulated - EPA has not established a maximum legal limit in tapwater for this contaminant.

Radon is a natural (radioactive) breakdown product of uranium in soil, rock and water. Potential health impacts associated with Radon include cancer and respiratory toxicity. [read more]

Sources of Radon:

Naturally Occurring (naturally present but increased for lands denuded by sprawl, agriculture, or industrial development)

An Environmental Working Group analysis of Radon tests reported by 1,483 public water suppliers in 19 states shows that between 1998 and 2003, 34.8 million people in 1,219 communities drank water contaminated with Radon. In 879 of these communities, tap water was contaminated at levels above health-based thresholds. Radon remains unregulated in tap water, without a maximum legal limit.

Exposure Summary

34,841,477 People drinking water contaminated with Radon 1,219 Communities served water contaminated with Radon 12,434,478 People drinking water contaminated with Radon over health based limits 879 Communities served water with Radon above health based limits

Table. Radon Exposure by State

12.4 million Americans in 16 states were served tap water contaminated with Radon at levels above health-based limits between 1998 and 2003.

State	Water suppliers with Radon contamination		Water suppliers reporting Radon above health-based limits
	Systems	Population	Systems	Population
California	211	28,295,282	165	7,859,805
Nevada	24	1,503,279	23	1,494,879
Minnesota	480	2,793,317	284	1,178,819
Ohio	34	858,896	20	817,303
Wisconsin	142	280,973	107	232,661
Arizona	1	180,000	1	180,000
Colorado	63	319,387	43	170,418
Maine	142	170,516	129	151,296
Nebraska	53	134,135	48	126,720
Massachusetts	8	142,278	7	108,278
Oregon	3	69,580	2	62,380
New York	45	45,111	42	36,256
New Mexico	2	10,695	2	10,695
Montana	4	4,337	4	4,337
Iowa	1	531	1	531
Wyoming	2	25,099	1	100
Alabama	3	7,971	0	0
Pennsylvania	1	90	0	0
Total	1,219	34,841,477	879	12,434,478

Table. The most polluted communities

12.4 million Americans in 879 communities were served tap water contaminated with Radon above health based limits between 1998 and 2003

Ranked by highest average Radon level

Rank	System	Population Served	Positive test results of total reported tests	Average Level (Range)
1	Dearborn Hill Apartments Bangor, ME	60	3 of 4	5646.33 pCi/L (5133 to 5908 pCi/L)
2	Sunlight View Ii Glenwood Springs, CO	110	1 of 1	5600 pCi/L (5600 to 5600 pCi/L)
3	Crescent Mobile Home Park Keene, NH	133	2 of 4	5542 pCi/L (5524 to 5560 pCi/L)
4	Town of Sawpit Water Placerville, CO	50	1 of 1	5470 pCi/L (5470 to 5470 pCi/L)
5	Stratford Waterworks Stratford, WI	1,651	1 of 1	5330 pCi/L (5330 to 5330 pCi/L)
6	Pine Mountain Mobile Home Court Grand Marais, MN	60	3 of 3	5323.33 pCi/L (4760 to 5680 pCi/L)
7	Alpine Water Users Association Twin Peaks, CA	3,000	3 of 4	5273.33 pCi/L (4340 to 5920 pCi/L)
8	Canton Point Park Greene, ME	73	2 of 2	5046.5 pCi/L (4760 to 5333 pCi/L)
9	Countryside Mobile Homes Menomonie, WI	50	1 of 1	4910 pCi/L (4910 to 4910 pCi/L)
10	Country Meadow Apartments Augusta, ME	53	1 of 1	4845 pCi/L (4845 to 4845 pCi/L)

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Health based limits for Radon

Health Limit	Limit Value	Limit Description
One in ten thousand (10-4) Cancer Risk	150 pCi/L	The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000. Source: U.S. Environmental Protection Agency.

Testing Summary for Radon

Water suppliers report an average of 0.5 Radon tests per year. 38,268 water suppliers failed to report any Radon tests at all.

Are tests routinely required for Radon by federal law? No Water suppliers reporting tests for Radon (1998-2003): 1,483 of 39,751 Average testing rate for water supplier reporting tests (1998-2003): 0.5 per year

Radon Violations

Because Radon is unregulated in tap water, no violations are recorded in EPA's violations database, the Safe Drinking Water Information System. Under the federal tap water law, water suppliers are not required to routinely test for Radon, and any level is legal in tap water.