Water quality · Indiana
Water quality in Indiana
Water quality (EPA SDWIS) data for ZIP codes in Indiana. Pick a ZIP below to dive into the water quality summary.
Last verified 2026-05-13 · methodology
What lands here
Pages show the CWS serving the address, any health-based violations in the last 3 years, most recent lead and copper sampling result, and a link to the primary SDWIS record.
Source & refresh
EPA SDWIS. Refreshed quarterly (federal mandate). Primary source →
Indiana top concern
Radon, lead pipes (older Rust Belt cities)
Indiana has Zone 1 radon coverage across most counties. Lead-service-line inventories under LCRR are heaviest in Gary, South Bend, Hammond, Indianapolis. Tornado exposure peaks April-June.
See Indiana state page for the full state-level rollup across all 12 dimensions.
Read more on water quality
Editorial deep-dives explaining the source data, its limits, and how to read it.
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EPA Radon Zones — what 1, 2, and 3 mean and when you should test
EPA classifies every US county into Zone 1 (high), Zone 2 (moderate), or Zone 3 (low) for radon. Plain-English guide to the classifications and at-home testing.
Lead and Copper Rule 2024 — the federal lead-pipe inventory mandate
The 2024 Lead and Copper Rule Revisions (LCRR) require every US community water system to inventory and report lead service lines. Plain-English guide.
AQI explained — what 50, 100, 150 actually mean for your lungs
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