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EWG Statement, 03/10/2008

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NATIONAL SUMMARY

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CONTAMINANTS DATABASE

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

Metolachlor is an herbicide for corn, soybeans, peanuts, cotton, pod crops. Potential health impacts associated with Metolachlor include cancer. [read more]

Sources of Metolachlor:

Agriculture (pesticides, fertilizer, factory farms)

An Environmental Working Group analysis of Metolachlor tests reported by 16,754 public water suppliers in 36 states shows that between 1998 and 2003, 6.8 million people in 175 communities drank water contaminated with Metolachlor. Metolachlor remains unregulated in tap water, without a maximum legal limit.

Exposure Summary

6,791,300 People drinking water contaminated with Metolachlor 175 Communities served water contaminated with Metolachlor

Table. Metolachlor Exposure by State

6.8 million Americans in 17 states were served tap water contaminated with Metolachlor between 1998 and 2003.

State	Water suppliers with Metolachlor contamination
	Systems	Population
Indiana	5	1,216,350
Ohio	3	1,053,606
Arizona	4	859,316
Virginia	2	795,800
Texas	33	658,438
Nebraska	13	632,973
Iowa	35	522,025
Illinois	37	411,262
California	6	297,423
Missouri	24	157,663
Pennsylvania	2	126,295
North Carolina	1	29,604
New York	3	20,721
Wisconsin	4	8,446
Michigan	1	1,006
Minnesota	1	276
New Mexico	1	96
Total	175	6,791,300

Table. The most polluted communities

6.8 million Americans in 175 communities were served tap water contaminated with Metolachlor between 1998 and 2003

Ranked by highest average Metolachlor level

Rank	System	Population Served	Positive test results of total reported tests	Average Level (Range)
1	Kiron Water Supply Kiron, IA	273	1 of 1	18 ppb (18 to 18 ppb)
2	Burkeville, Town Of Burkeville, VA	800	4 of 6	5.99 ppb (0 to 18.7 ppb)
3	Gladbrook Water Supply Gladbrook, IA	1,015	2 of 3	2.46 ppb (0 to 7 ppb)
4	City of Kearney Water Kearney, NE	24,889	2 of 15	1.87 ppb (0 to 19.7 ppb)
5	Sioux Rapids Water Department Sioux Rapids, IA	720	1 of 1	1.6 ppb (1.6 to 1.6 ppb)
6	Graettinger Municipal Water Supply Graettinger, IA	900	9 of 12	1.55 ppb (0 to 8.8 ppb)
7	West Branch Water Works West Branch, IA	2,188	8 of 8	1.51 ppb (0.98 to 1.9 ppb)
8	Maurice Municipal Water Supply Maurice, IA	254	3 of 3	1.37 ppb (1.1 to 1.8 ppb)
9	Cedar River Trailer Park Columbus Junction, IA	53	4 of 5	1.36 ppb (0 to 4.9 ppb)
10	Peterson Municipal Water Supply Peterson, IA	372	1 of 1	1.3 ppb (1.3 to 1.3 ppb)

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Health based limits for Metolachlor

Health Limit	Limit Value	Limit Description
Children's health-based limit for 1-day exposure	2000 ppb	Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.
Children's health-based limit for 10-day exposure	2000 ppb	Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.
Lifetime health-based limit, non-cancer risk	100 ppb	Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.
Drinking Water Equivalent Level	5000 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 Metolachlor

Water suppliers report an average of 0.5 Metolachlor tests per year. 22,997 water suppliers failed to report any Metolachlor tests at all.

Are tests routinely required for Metolachlor by federal law? No Water suppliers reporting tests for Metolachlor (1998-2003): 16,754 of 39,751 Average testing rate for water supplier reporting tests (1998-2003): 0.5 per year

Metolachlor Violations

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