40 CFR 312.22: Additional inquiries.

(a) Persons identified under § 312.1(b) must conduct the inquiries listed in paragraphs (a)(1) through (a)(4) below and may provide the information associated with such inquiries to the environmental professional responsible for conducting the activities listed in § 312.21:

(1) As required by § 312.25 and if not otherwise obtained by the environmental professional, environmental cleanup liens against the subject property that are filed or recorded under federal, tribal, state, or local law;

(2) As required by § 312.28, specialized knowledge or experience of the person identified in § 312.1(b);

(3) As required by § 312.29, the relationship of the purchase price to the fair market value of the subject property, if the property was not contaminated; and

(4) As required by § 312.30, and if not otherwise obtained by the environmental professional, commonly known or reasonably ascertainable information about the subject property.