Data sources

Every record on this site originates in a public filing made to a delegated NESHAP authority. Each record page names the agency it came from and links to the original where the agency provides a stable URL.

How coverage varies

Some agencies publish a searchable database; we collect from those directly. Others release records only in response to a written public information request; for those jurisdictions our coverage updates on the cadence the agency responds to requests, which can be weekly or slower.

Accuracy

We normalise addresses and company names, but we do not invent data. A blank field means the agency's record was blank. Always verify against the issuing agency before relying on a record for a commercial decision.