Changelog

A dated record of data refreshes, corrections, and methodology changes on PlainEnviro. We list only real, verifiable changes. See our corrections process if a figure looks wrong, or methodology for how the EPA pipeline works. For annual TRI release deltas by facility, see Annual TRI Changes.

Index hygiene

Dead water-system state hubs dropped from hub sitemap

Removed DEAD_WSYS noindex state hubs (AK/HI/MD/NJ/VI) from sitemap-water-systems while keeping the indexable /water-systems hub. Entity shards for those states were already emptied.

Accountability

Public /corrections alias and identity CiteThis blocks

Added a /corrections redirect to the editorial corrections process, a public /changelog of corroborated changes, and Cite this page blocks on identity and legal pages so readers have a stable citation string and a clear path to report data issues.

Index hygiene

Noindex browse letter hubs dropped from static sitemap

Removed /browse/facilities/[a-z] letter hubs from sitemap-static while keeping the indexable /browse/facilities hub (commit 9b968c0). Those letter pages stay noindex,follow.

Index hygiene

Noindex /search dropped from static sitemap

Stopped advertising /search in sitemap-static because the page is robots noindex,follow (commit 2345676).

Crawl freshness

Honest per-page sitemap lastmod

Static and index sitemap entries now stamp lastmod from git or data vintage per page instead of a single portal-wide fingerprint (commit 5fe76bd).

Index hygiene

Dead state shards dropped from sitemap index

Sitemap index no longer advertises empty DEAD state shards that had zero live URLs (commit d4e9976).

Crawl hygiene

Unknown air-quality states return real HTTP 404

Air-quality state routes for unknown slugs now return HTTP 404 instead of soft-404 redirects (commit cef5877).

Download the environmental statistics extract cited on this page: plainenviro-environmental-statistics.csv (EPA public records · CC BY 4.0).