About our data

• New Jersey: DCA lists of certified lead evaluation contractors (revised Aug 11, 2026) and lead abatement contractors (revised July 15, 2026), parsed from PDF. Firms on both lists are merged.
• New York: EPA Lead-Based Paint Professional Locator, all NY firms certified for evaluation or abatement, retrieved 2026-10-12.
• Massachusetts: licensed private lead inspector list (individuals), grouped into firms by business email domain or company name.
• Cleanup: expired certifications dropped; case and phone formats normalized; counties from ZIP or city (GeoNames, CC BY 4.0). All changes are in data/cleanup-log.csv.
• Not yet included: NJDOH individual licensees, EPA-certified individuals in NY, and the MA deleading contractor list.