USGS-Monitored Groundwater Wells

Data current as of June 2026 — recomputed by ZipCheckup from federal data each build.

Per ZipCheckup's reading of USGS groundwater data, 506,398 monitoring wells are tracked across U.S. ZIP codes, as of June 2026.

USGS records show 506,398 groundwater monitoring wells across U.S. ZIP codes.

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Open data, licensed CC BY 4.0 · DOI: 10.5281/zenodo.19427201

How we compute this

We count the groundwater monitoring wells in the U.S. Geological Survey’s national water-data network and map them to ZIP codes. The figure recomputes when USGS refreshes its site inventory.

A monitoring well is an observation point for water-level and quality measurements, not a drinking-water source or a contamination reading. Well density reflects where USGS and partners have instrumented the aquifer system.

We translate the USGS site inventory rather than estimate it. Coverage is uneven by design, concentrated where groundwater is actively studied or managed.

Source: U.S. Geological Survey (USGS) groundwater monitoring network

Every number here is recomputed from public federal data on each build by open-source code in the ZipCheckup repository; a dated CSV snapshot is published with each finding. No data does not mean safe.

Frequently asked questions

How many groundwater wells does the USGS monitor?

Per ZipCheckup's reading of USGS groundwater data, 506,398 monitoring wells are tracked across U.S. ZIP codes, as of June 2026. Monitoring wells are observation points, not drinking-water sources. according to ZipCheckup's reading of federal data as of June 2026.