EWG INVESTIGATION

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

Perchlorate is an oxygen additive in solid fuel propellant for rockets, missiles, and fireworks. No information on potential health impacts for Perchlorate was identified in standard government and academic sources. [read more]

Sources of Perchlorate:

	Agriculture (pesticides, fertilizer, factory farms)
	Industry

An Environmental Working Group analysis of Perchlorate tests reported by 982 public water suppliers in 7 states shows that between 1998 and 2003, 26.2 million people in 86 communities drank water contaminated with Perchlorate. In 8 of these communities, tap water was contaminated at levels above health-based thresholds. Perchlorate remains unregulated in tap water, without a maximum legal limit.

Exposure Summary

26,237,842 People drinking water contaminated with Perchlorate 86 Communities served water contaminated with Perchlorate 211,734 People drinking water contaminated with Perchlorate over health based limits 8 Communities served water with Perchlorate above health based limits

Table. Perchlorate Exposure by State

212 thousand Americans in 2 states were served tap water contaminated with Perchlorate at levels above health-based limits between 1998 and 2003.

State	Water suppliers with Perchlorate contamination		Water suppliers reporting Perchlorate above health-based limits
	Systems	Population	Systems	Population
Texas	2	111,850	2	111,850
California	81	25,583,466	6	99,884
Minnesota	2	515,026	0	0
Pennsylvania	1	27,500	0	0
Total	86	26,237,842	8	211,734

Table. The most polluted communities

212,000 Americans in 8 communities were served tap water contaminated with Perchlorate above health based limits between 1998 and 2003

Ranked by highest average Perchlorate level

Rank	System	Population Served	Positive test results of total reported tests	Average Level (Range)
1	City of Levelland Levelland, TX	13,805	1 of 1	32 ppb (32 to 32 ppb)
2	City of La Verne Water Department La Verne, CA	34,009	38 of 48	11.17 ppb (0 to 26 ppb)
3	La Quinta Ridge Mobile Estates Indio, CA	350	1 of 1	9 ppb (9 to 9 ppb)
4	La Puente Valley Cwd La Puente, CA	7,500	30 of 142	8.38 ppb (0 to 129 ppb)
5	Industry Waterworks System City Of Industry, CA	5,000	16 of 19	7.42 ppb (0 to 14 ppb)
6	City of Midland Water Midland, TX	98,045	3 of 3	7.31 ppb (4 to 10 ppb)
7	Lsid - Tonyville Lindsay, CA	400	2 of 2	7.15 ppb (6.8 to 7.5 ppb)
8	Scwc - San Dimas San Dimas, CA	52,625	22 of 41	6.16 ppb (0 to 17.9 ppb)

Health based limits for Perchlorate

Health Limit	Limit Value	Limit Description
California Public Health Goals	6 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 Perchlorate

Water suppliers report an average of 1.6 Perchlorate tests per year. 38,769 water suppliers failed to report any Perchlorate tests at all.

Are tests routinely required for Perchlorate by federal law? No Water suppliers reporting tests for Perchlorate (1998-2003): 982 of 39,751 Average testing rate for water supplier reporting tests (1998-2003): 1.6 per year

Perchlorate Violations

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