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Water: Drinking Water Standards

Drinking Water Science and Regulatory Support

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Drinking Water Standards and Health Advisories Tables

These tables summarize the drinking water regulations and health advisory values as well as the reference dose (RFD) and cancer risk values for drinking water contaminants.

Drinking water and health advisory summary tables are prepared periodically. They contain drinking water standards in the form of non-enforceable concentrations of drinking water contaminants, Maximum Contaminant Level Goals (MCLGs), or enforceable Maximum Contaminant Levels (MCLs). Maximum Contaminant Levels are the maximum permissible level of a contaminant in water delivered to users of a public water system. Health Advisories (HAs) provide information on contaminants that can cause human health effects and are known or anticipated to occur in drinking water. Health Advisories are guidance values based on non-cancer health effects for different durations of exposure (e.g., one-day, ten-day, and lifetime). They provide technical guidance to our Regional Offices, State governments, and other public health officials on health effects, analytical methodologies, and treatment technologies associated with drinking water contamination.

In the 2012 tables, EPA introduced a new policy of calculating lifetime health advisories for all drinking water contaminants, regardless of their carcinogenicity status. By making non-cancer benchmarks available, EPA is providing risk assessment managers values they can compare with the cancer risk level drinking water concentration (10-4 cancer risk) to determine which number provides a more meaningful scenario-specific risk reduction. EPA defines the lifetime health advisories as the concentration in drinking water that is not expected to cause any adverse non-carcinogenic effects for a lifetime of exposure. The 10 4 cancer risk is the concentration of the chemical contaminant in drinking water that is associated with a specific probability of cancer. EPA advises consideration of the more conservative cancer risk levels (10-5 or 10-6), found in the IRIS or RED source documents, if risk assessment managers consider them more appropriate for exposure-specific risk assessment.

2012 Drinking Water Standards and Health Advisories tables (PDF) (20 pp, 359K; EPA 822-S-12-001)

Archived tables

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Human Health Benchmarks for Pesticides

EPA has developed human health benchmarks for approximately 363 pesticides to enable our partners to better determine whether the detection of a pesticide in drinking water or source waters for drinking water may indicate a potential health risk.

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Estimated Per Capita Water Ingestion in the United States

Drinking Water Health Advisories:  Estimated Per Capita Water Ingestion in the United States - 2004
This report provides current estimates of water ingestion and body weight for the population of the U.S. and selected subpopulations including pregnant women, lactating women and women of child-bearing age.

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Chemical Contaminants

Health and Drinking Water Advisories for Chemical Contaminants

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Microbiological Contaminants

Regulatory Support Documents for Microbiological Contaminants

Criteria documents and guidance for drinking water contaminants provide information so preliminary decisions can be made as to whether the contaminant is a significant health threat via drinking water exposure and whether sufficient data exists to perform quantitative risk assessments.

Children's Risk

Health Advisories for Microbiological Contaminants

Health Advisories serve as informal technical guidance to assist federal, state, and local officials responsible for protecting public health when emergency spills or contamination situations occur. They are not to be construed as legally enforceable federal standards. The Health Advisories are subject to change as new information becomes available.

Fact Sheets

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