ZipCheckup's National Data-Anomaly Scan

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

ZipCheckup's cross-dataset scan flagged 23,151 data patterns across 42,680 U.S. ZIP codes, grouped into 10 categories, as of June 2026.

ZipCheckup's automated scan flagged 23,151 data patterns across 42,680 U.S. ZIP codes, sorted into 10 categories, as of June 2026.

By state

categorycount
Composite score diverges from an underlying signal6,226
Concentrated enforcement activity9,045
Elevated readings near schools236
Elevated readings with no violation on record485
Higher-income ZIPs with elevated readings1,579
Infrastructure age inconsistent with risk profile12
Lower-risk ZIPs amid higher-risk neighbors1,497
Multiple overlapping risks in one ZIP11
PFAS exceedance clusters (adjacent ZIPs)548
Sharp period-over-period score change3,512
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Open data, licensed CC BY 4.0 · DOI: 10.5281/zenodo.19427201

How we compute this

This is ZipCheckup's own analysis, not a federal count. We run an automated scan that cross-references EPA drinking-water, PFAS, radon, FEMA flood, and Census signals for each ZIP code and flags patterns worth a closer look — adjacent PFAS exceedances, scores that diverge from an underlying reading, concentrated enforcement, and similar.

The category labels are written in plain language; ZipCheckup's raw internal slugs are not exposed. Categories are listed alphabetically with their counts. A flagged pattern is a prompt to investigate the underlying federal data, never a verdict about a place.

The scan recomputes each build, so counts move as federal extracts update. Every flagged ZIP links to its full per-ZIP report, where the underlying data is shown in context.

Source: ZipCheckup cross-dataset anomaly scan (EPA SDWIS/ECHO, UCMR5 PFAS, EPA radon, FEMA flood, U.S. Census)
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 data anomalies did ZipCheckup find?

ZipCheckup's automated scan flagged 23,151 data patterns across 42,680 U.S. ZIP codes as of June 2026, grouped into 10 categories. This is ZipCheckup's own cross-dataset analysis, not a federal count. according to ZipCheckup's reading of federal data as of June 2026.

What kinds of patterns does the scan detect?

The scan sorts 23,151 flagged patterns into 10 categories — from PFAS exceedance clusters to concentrated enforcement activity — listed alphabetically with their counts as of June 2026. Each is a data pattern worth a closer look, not a verdict.