EWG Investigation | U.S. Tap Water Quality Database

Health Limit Exceeded
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Legal Limit
• EPA set legal limit which balances health concerns and treatment costs

Tier 3 Control - past mining and drilling
• Closed or abandoned mines/plans/notices
• Mineral rich land that has been titled to mining interests (mining patents)
• Formerly drilled and pumped oil & gas Leases

EWG INVESTIGATION

Findings

About The Data

News Release

EWG Statement, 03/10/2008

Asbestos

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

Asbestos is a mineral fiber from decay of asbestos cement in water mains. Potential health impacts associated with Asbestos include cancer, immunotoxicity, and respiratory toxicity. [read more]

Sources of Asbestos:
Water Treatment Water Treatment and Distribution Byproducts (pipes and fixtures, treatment chemicals and byproducts)

An Environmental Working Group analysis of Asbestos tests reported by 2,533 public water suppliers in 26 states shows that between 1998 and 2003, 8.6 million people in 147 communities drank water contaminated with Asbestos. In 2 of these communities, tap water was contaminated at levels above health-based thresholds.

Exposure Summary

8,582,708
People drinking water contaminated with Asbestos
147
Communities served water contaminated with Asbestos
6,748
People drinking water contaminated with Asbestos over health based limits
2
Communities served water with Asbestos above health based limits

Table. Asbestos Exposure by State

6,748 Americans in 2 states were served tap water contaminated with Asbestos at levels above health-based limits between 1998 and 2003.

State Water suppliers with Asbestos contamination Water suppliers reporting Asbestos above health-based limits
Systems Population Systems Population
Arizona 6 1,896,905 1 6,695
California 21 4,431,881 1 53
Tennessee 37 1,158,987 0 0
Florida 32 782,164 0 0
Washington 27 215,853 0 0
South Carolina 8 43,971 0 0
Utah 1 17,500 0 0
Alaska 2 9,647 0 0
Pennsylvania 1 6,000 0 0
Nevada 1 5,800 0 0
Iowa 2 4,694 0 0
New York 1 4,200 0 0
Idaho 1 2,340 0 0
Maine 1 1,725 0 0
Wisconsin 4 841 0 0
Indiana 2 200 0 0
Total 147 8,582,708 2 6,748

Table. The most polluted communities

6,748 Americans in 2 communities were served tap water contaminated with Asbestos above health based limits between 1998 and 2003

Ranked by highest average Asbestos level

Rank System Population Served Positive test results of total reported tests Average Level
(Range)
1 City of Showlow - Municipal Water
Showlow, AZ 6,695 1 of 2 12.45 MFL
(0 to 24.9 MFL)
2 Green Acres Mutual Water
Morgan Hill, CA 53 16 of 23 10.37 MFL
(0 to 105.68 MFL)

Health based limits for Asbestos

Health Limit Limit Value Limit Description
Maximum Contaminant Limit (MCL) 7 MFL 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.
Maximum Contaminant Limit Goal (MCLG) 7 MFL A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.
One in ten thousand (10-4) Cancer Risk 700 MFL The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000. Source: U.S. Environmental Protection Agency.
California Public Health Goals 7 MFL 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 7 MFL 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.

Testing Summary for Asbestos

Water suppliers report an average of 0.3 Asbestos tests per year. 37,218 water suppliers failed to report any Asbestos tests at all.

Are tests routinely required for Asbestos by federal law? Yes
Water suppliers reporting tests for Asbestos (1998-2003): 2,533 of 39,751
Average testing rate for water supplier reporting tests (1998-2003): 0.3 per year

Asbestos Violations

Table. 0.1 percent of all water suppliers violated safe drinking water standards for Asbestos between 1998 and 2003

Violation Type Violations Systems
Any Violation (1998-2003) 78 60
(0.1% of all suppliers)
Testing violations (1998-2003) 66 53
(< 0.1% of all suppliers)
Violations of tap water pollution standards (1998-2003) 12 8
(< 0.1% of all suppliers)