EWG Arsenic, Nitrate & Chromium-6 Co-occurrence Map
Environmental Working Group interactive map showing co-occurrence of arsenic, nitrate, and chromium-6 in drinking water affecting 100 million+ people in the US, with system-level detection data
ewg.org
At a glance
- Region
- United States (North America)
- Coverage
- US drinking water systems: 100M+ people affected
- Access
- Free
- Category
- Non-Profit
- Last updated
- 2025
What's inside
- Arsenic Contamination
- Nitrate Contamination
- Chromium-6 Contamination
- Drinking Water Quality
- Co-occurrence Analysis
What you can do with it
Typical work that data of this type supports.
- 01
Hotspots and trends
Find where contamination is high and whether it is getting worse.
Because it has: Arsenic Contamination
- 02
Compliance checks
Compare samples against drinking water and discharge standards.
- 03
Coverage gaps
Find who lacks safe water or sanitation.
Because it has: Drinking Water Quality
Where AI adds value
Ideas for machine learning and AI agents built on this kind of data.
- 01
Risk maps
Predict contamination where no samples exist, from geology, land use and climate.
- 02
Anomaly alerts
Catch sudden spikes in sensor or lab data automatically.
- 03
Failure prediction
Predict pipe bursts and plant failures before they happen.
Related water data
- EWG National Nitrate Analysis Interactive MapNorth America | Free
- GitHub Waterhackweek Mapping Groundwater ContaminantsNorth America | Free
- USGS Estimated Nitrate and Arsenic in SW US Basin-Fill Aquifers (SIM 3234)North America | Free
- EPA UCMR 5 PFAS Drinking Water DataNorth America | Free
- EWG Tap Water Database (2025 Edition)North America | Free
- USGS Arsenic Concentrations in Groundwater of the United StatesNorth America | Free
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