MAP OF CONTAMINANTS IN DRINKING WATER

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The Contaminant Occurrence Map contains water quality data from 2019-2023 for 22 different drinking water analytes in the United States.

​Interactive Map
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How To Video

Our Contaminant Occurrence Map provides an interactive, data-driven view of water quality across the United States. This study analyzes the presence and concentration of contaminants in drinking water systems, including PFAS, nitrates, heavy metals, and other pollutants. Users can explore contamination trends, compare geographic areas, and access detailed insights into environmental health. Designed for researchers, policymakers, industry members, and the public, this resource supports informed decisions about water quality and regulatory compliance. Discover contamination hotspots, emerging contaminants, and risk factors through our comprehensive mapping tool. Starting in January 2026, WQRF will begin another round of data collection for our contaminant occurrence database, updating it with data from 2023 through 2025.

REPORTS

Contaminant Occurrence Above the MCLG (regulated contaminants): ​Summary​​, Report 

Aesthetics Occurrence (hardness, iron, pH, manganese, disinfection residuals): Summary, Report

Alkalinity, chloride, corrosivity, LSI, nitrate, nitrate-nitrite, orthophosphate, total phosphate, and sulfate: Report

1,4-dioxane, Cr6, PCE, Uranium, radium, calcium, magnesium, radon, strontium: Report

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Summaries and educational materials (toolkits, handouts, infographics, etc.) are publicly available resources, and the full scientific reports are free for Water Quality Association (WQA) members.

 ​If you are not a WQA member, please contact [email protected] to inquire about access to the full report(s) of interest.