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EWG Statement, 03/10/2008

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NATIONAL SUMMARY

Quality Varies Across the U.S.

CONTAMINANTS DATABASE

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

Arsenic (total) is a metal that enters water by erosion of natural deposits, runoff from glass and electronics processing. Potential health impacts associated with Arsenic (total) include cancer, cardiovascular or blood toxicity, developmental toxicity, endocrine toxicity, gastrointestinal or liver toxicity, kidney toxicity, neurotoxicity, reproductive toxicity, respiratory toxicity, and skin sensitivity. [read more]

Sources of Arsenic (total):

	Sprawl and Urban Areas (road runoff, lawn pesticides, human waste)
	Industry
	Naturally Occurring (naturally present but increased for lands denuded by sprawl, agriculture, or industrial development)

An Environmental Working Group analysis of Arsenic (total) tests reported by 30,575 public water suppliers in 41 states shows that between 1998 and 2003, 90.1 million people in 9,957 communities drank water contaminated with Arsenic (total). In 9,956 of these communities, tap water was contaminated at levels above health-based thresholds.

Exposure Summary

90,097,384 People drinking water contaminated with Arsenic (total) 9,957 Communities served water contaminated with Arsenic (total) 90,096,056 People drinking water contaminated with Arsenic (total) over health based limits 9,956 Communities served water with Arsenic (total) above health based limits

Table. Arsenic (total) Exposure by State

90.1 million Americans in 38 states were served tap water contaminated with Arsenic (total) at levels above health-based limits between 1998 and 2003.

State	Water suppliers with Arsenic (total) contamination		Water suppliers reporting Arsenic (total) above health-based limits
	Systems	Population	Systems	Population
California	1,061	41,379,839	1,060	41,378,511
Texas	1,267	8,145,634	1,267	8,145,634
Illinois	600	5,605,255	600	5,605,255
Florida	506	4,621,770	506	4,621,770
Arizona	567	4,405,061	567	4,405,061
Michigan	979	3,136,414	979	3,136,414
Nevada	180	2,152,522	180	2,152,522
Washington	301	1,928,148	301	1,928,148
Utah	265	1,864,778	265	1,864,778
Wisconsin	405	1,662,062	405	1,662,062
Pennsylvania	230	1,494,919	230	1,494,919
New Mexico	391	1,337,752	391	1,337,752
Nebraska	381	1,211,904	381	1,211,904
Minnesota	410	1,088,910	410	1,088,910
Colorado	174	1,061,728	174	1,061,728
Indiana	200	948,868	200	948,868
New Jersey	28	948,200	28	948,200
Kentucky	78	924,743	78	924,743
Missouri	163	826,193	163	826,193
North Carolina	61	786,810	61	786,810
Iowa	217	747,137	217	747,137
Tennessee	27	649,519	27	649,519
Idaho	273	535,731	273	535,731
Ohio	140	466,804	140	466,804
New Hampshire	240	343,873	240	343,873
Montana	95	311,378	95	311,378
North Dakota	159	296,883	159	296,883
Maine	188	274,537	188	274,537
Alaska	155	246,846	155	246,846
Delaware	18	221,158	18	221,158
Oregon	103	202,303	103	202,303
Virginia	19	122,613	19	122,613
Arkansas	15	61,715	15	61,715
New York	25	57,775	25	57,775
Wyoming	33	24,197	33	24,197
Alabama	1	3,285	1	3,285
Rhode Island	1	95	1	95
Massachusetts	1	25	1	25
Total	9,957	90,097,384	9,956	90,096,056

Table. The most polluted communities

90.1 million Americans in 9,956 communities were served tap water contaminated with Arsenic (total) above health based limits between 1998 and 2003

Ranked by highest average Arsenic (total) level

Rank	System	Population Served	Positive test results of total reported tests	Average Level (Range)
1	Igiugig Water System King Salmon, AK	100	1 of 1	126 ppb (126 to 126 ppb)
2	Why Utility Corp Why, AZ	480	7 of 7	122.29 ppb (5 to 176 ppb)
3	Four Seasons Mobile / Rv Park Santa Barbara, CA	350	1 of 1	116 ppb (116 to 116 ppb)
4	Fallon Naval Air Station Fallon, NV	3,000	4 of 4	112.5 ppb (100 to 120 ppb)
5	Sandy Stream Park Palmyra, ME	88	2 of 2	110.5 ppb (110 to 111 ppb)
6	City of Fallon Water Fallon, NV	8,400	12 of 12	103.33 ppb (90 to 140 ppb)
7	City of Richfield Water Richfield, ID	420	1 of 1	100 ppb (100 to 100 ppb)
8	Johnson Creek Durham, NH	50	1 of 1	99 ppb (99 to 99 ppb)
9	Philadelphia Water System Crown King, AZ	75	4 of 4	97.75 ppb (96 to 100 ppb)
10	Spinsfield Commons Orland, ME	105	10 of 11	94.73 ppb (0 to 151 ppb)

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Health based limits for Arsenic (total)

Health Limit	Limit Value	Limit Description
Maximum Contaminant Limit (MCL)	10 ppb	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.
California Public Health Goals	<0.01 ppb	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.
EPA Human Health Water Quality Criteria	0.02 ppb	Water quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.
Drinking Water Equivalent Level	10 ppb	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.

Testing Summary for Arsenic (total)

Water suppliers report an average of 0.4 Arsenic (total) tests per year. 9,176 water suppliers failed to report any Arsenic (total) tests at all.

Are tests routinely required for Arsenic (total) by federal law? Yes Water suppliers reporting tests for Arsenic (total) (1998-2003): 30,575 of 39,751 Average testing rate for water supplier reporting tests (1998-2003): 0.4 per year

Arsenic (total) Violations

Table. 3.5 percent of all water suppliers violated safe drinking water standards for Arsenic (total) between 1998 and 2003

Violation Type	Violations	Systems
Any Violation (1998-2003)	2,710	2,001
	(3.5% of all suppliers)
Testing violations (1998-2003)	2,581	1,975
	(3.5% of all suppliers)
Reporting violations (1998-2003)	1	1
	(< 0.1% of all suppliers)
Violations of tap water pollution standards (1998-2003)	128	48
	(< 0.1% of all suppliers)