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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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Tap Water Quality Report The State of Wyoming 284 Water Systems Serving 440,125 People

An Environmental Working Group analysis of tap water tests from 1998 through 2003 for 284 communities across Wyoming shows 57 pollutants were found in drinking water across the state.

Pollution Summary

57 35	12 6	12 7	38 24	14 11	21 13
Total pollutants	Agricultural pollutants	Sprawl and Urban pollutants	Industrial pollutants	Water Treatment and Distribution Byproducts	Naturally occurring pollutants
Number of pollutants detected (1998 - 2003)			Over health based limits

NOTE: Health based limits included in this analysis include enforceable drinking water limits (called Maximum Contaminant Limits, or MCLs) as well as governmental, non-enforceable health guidelines, such as Maximum Contaminant Limit Goals (MCLGs), lifetime health advisory levels, one-day and ten-day advisory levels to protect children from non-cancer health endpoints, and other government-established health guidelines for tap water contaminants.

Health Summary

The federal government has set standards for 80 chemical pollutants in tap water, balancing health concerns and treatment costs.

Contaminants found in state tap water (1998-2003): 57

Total population exposed above health-based limits: 235,222

Communities served water with contaminants above health-based limits: 97

Health effects or target organs of contaminants found: Cardiovascular or Blood Toxicity, Cancer, Developmental Toxicity, Endocrine Toxicity, Immunotoxicity, Kidney Toxicity, Gastrointestinal or Liver Toxicity, Neurotoxicity, Reproductive Toxicity, Respiratory Toxicity, and Skin Sensitivity.

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Contaminants found above health based limits: 35

Rank	Contaminant Name	Population Exposed (of 440,125 Total)		Number of Water Systems (of 284) Total
		At Any Level	Above Health Limits See Note	With Detected	Above Health Limits See Note
1	Sulfate	295,100	0	202	0
		Substance from natural deposits, industrial processes, and agriculture
2	Nitrate & nitrite	218,024	70	184	1
		Chemical that enters water from fertilizer runoff, leaching septic tanks, and erosion of natural deposits
3	Nitrate	270,352	5,670	156	2
		Chemical that enters water from fertilizer runoff, leaching septic tanks, and erosion of natural deposits
4	Barium (total)	162,781	256	73	1
		Mineral from drilling and mining waste runoff; erosion of natrual deposits
5	Alpha particle activity (excl radon and uranium)	81,445	254	66	1
		From mining waste pollutants and natural sources
6	Arsenic (total)	24,197	24,197	33	33
		Metal that enters water by erosion of natural deposits, runoff from glass and electronics processing
7	Total trihalomethanes (TTHMs)	198,131	172,682	26	24
		Measure of four disinfection by-products
8	Chloroform	198,131	172,682	26	24
		Disinfection by-product
9	Bromodichloromethane	197,681	197,681	25	25
		Disinfection by-product
10	Trichloroacetic acid	185,453	13,277	23	4
		Disinfection by-product

View Full Table

NOTE: Health based limits included in this analysis include enforceable drinking water limits (called Maximum Contaminant Limits, or MCLs) as well as governmental, non-enforceable health guidelines, such as Maximum Contaminant Limit Goals (MCLGs), lifetime health advisory levels, one-day and ten-day advisory levels to protect children from non-cancer health endpoints, and other government-established health guidelines for tap water contaminants.

Testing Summary

The federal government has set standards for some of the pollutants found in tap water supplies.

Contaminants reported as tested by water suppliers in Wyoming		108
	Contaminants tested due to federal law:	90
	Contaminants tested in addition to those required by federal law:	18

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Violations Summary

According to EPA, in 2003 6% of America's public water systems reported one or more violations of a health-based drinking water standard, and 26% reported significant violations of either monitoring and reporting requirements or health-based standards.

Reported violations (1998 - 2003): 895

Number of WY systems with violations: 191 (67.3%)

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Information on violations is drawn directly from EPA's national violations database in the Agency's Safe Drinking Water Information System. Analyses by others have raised questions about the quality of the information in EPA's database. For the purposes of this investigation, EWG is not showing below or including in our analyses, those violations for individual water suppliers that occurred on days for which the total number of violations assigned by EPA to that water supplier was greater than 20. This criteria was based on common characteristics of incorrect violations data as identified by water utilities, from a review of EPA's violations data by several hundred utilities prior to the release of EWG's investigation.