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.

MTBE is a fuel additive used as an octane enhancer in unleaded gasoline; its ban or phaseout is in progress in 16 states as of December 2005. Potential health impacts associated with MTBE include cancer, developmental toxicity, gastrointestinal or liver toxicity, kidney toxicity, neurotoxicity, and skin sensitivity.

Sources of MTBE:

	Sprawl and Urban Areas (road runoff, lawn pesticides, human waste)
	Industry

An Environmental Working Group analysis of MTBE tests reported by 16,866 public water suppliers in 30 states shows that between 1998 and 2003, 32.7 million people in 632 communities drank water contaminated with MTBE. In 18 of these communities, tap water was contaminated at levels above health-based thresholds. MTBE remains unregulated in tap water, without a maximum legal limit.

Exposure Summary

32,724,110 People drinking water contaminated with MTBE 632 Communities served water contaminated with MTBE 75,208 People drinking water contaminated with MTBE over health based limits 18 Communities served water with MTBE above health based limits

Table. MTBE Exposure by State

75 thousand Americans in 7 states were served tap water contaminated with MTBE at levels above health-based limits between 1998 and 2003.

State	Water suppliers with MTBE contamination		Water suppliers reporting MTBE above health-based limits
	Systems	Population	Systems	Population
Indiana	9	190,281	2	50,120
New Hampshire	168	385,739	8	21,679
Michigan	9	24,890	1	1,758
New York	45	48,932	3	1,220
Maine	13	7,186	1	231
Virginia	6	1,595,205	2	155
Pennsylvania	23	948,046	1	45
California	50	24,605,230	0	0
New Jersey	110	3,034,340	0	0
Florida	7	523,626	0	0
Arkansas	76	436,216	0	0
Delaware	11	290,459	0	0
Illinois	32	240,255	0	0
Texas	11	195,007	0	0
South Carolina	13	60,380	0	0
Alabama	5	39,042	0	0
Alaska	1	36,100	0	0
Nevada	2	15,200	0	0
Nebraska	7	10,941	0	0
Wisconsin	6	8,967	0	0
Ohio	4	8,724	0	0
Rhode Island	10	6,725	0	0
Minnesota	2	5,644	0	0
Missouri	6	3,607	0	0
Iowa	1	2,358	0	0
Oklahoma	5	1,010	0	0
Total	632	32,724,110	18	75,208

Table. The most polluted communities

75,000 Americans in 18 communities were served tap water contaminated with MTBE above health based limits between 1998 and 2003

Ranked by highest average MTBE level

Rank	System	Population Served	Positive test results of total reported tests	Average Level (Range)
1	Gunstock Acres Village District Gilford, NH	1,200	1 of 1	620 ppb (620 to 620 ppb)
2	Adirondack Residential Ctr. Schyler Falls, NY	80	1 of 1	500 ppb (500 to 500 ppb)
3	Vails Grove Cooperative Brewster, NY	510	1 of 2	345 ppb (0 to 690 ppb)
4	Plainfield Village Water District Plainfield, NH	248	4 of 4	206.18 ppb (1.2 to 820 ppb)
5	Strawberry Hill Plaistow, NH	50	7 of 7	128.43 ppb (0.51 to 880 ppb)
6	Paradise Estates Rochester, NH	405	5 of 5	122.55 ppb (0.36 to 610 ppb)
7	Olde Country Village Townhouse Londonderry, NH	130	5 of 5	120.54 ppb (0.6 to 600 ppb)
8	Webbs Mhp Airville, PA	45	1 of 1	95.2 ppb (95.2 to 95.2 ppb)
9	Fairhaven Mhp Milford, NH	63	9 of 9	91.98 ppb (0.59 to 820 ppb)
10	Meadows At Cross River Bedford Hills, NY	630	3 of 3	47.33 ppb (26 to 73 ppb)

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Health based limits for MTBE

Health Limit	Limit Value	Limit Description
California Public Health Goals	13 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.

Testing Summary for MTBE

Water suppliers report an average of 0.8 MTBE tests per year. 22,885 water suppliers failed to report any MTBE tests at all.

Are tests routinely required for MTBE by federal law? No Water suppliers reporting tests for MTBE (1998-2003): 16,866 of 39,751 Average testing rate for water supplier reporting tests (1998-2003): 0.8 per year

MTBE Violations

Because MTBE 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 MTBE, and any level is legal in tap water.