40 CFR Part 312 (especially 40 CFR 312.20)
Establishes the standards and practices for conducting "all appropriate inquiries" into a property's environmental conditions prior to acquisition, satisfying the CERCLA innocent landowner, bona fide prospective purchaser, and contiguous property owner liability defenses. Under 40 CFR 312.20 the inquiry must be conducted by a qualified environmental professional within one year before acquisition (with certain components, such as interviews, lien searches, government-records review, and the site visit, completed within 180 days). EPA recognizes ASTM International Standard E1527-21 as an accepted method for the Phase I Environmental Site Assessment process to satisfy these requirements (E2247-23 applies to forestland/rural property).
40 CFR Part 112
40 CFR Part 230
40 CFR Part 262
40 CFR Part 280
40 CFR Part 61, Subpart M (esp. 40 CFR 61.145, 61.150)
40 CFR Part 745
Pin a building and we'll surface every amendment, effective-date change, and filing deadline as it happens.