(a) Throughout the inquiries, persons to whom this part is applicable per § 312.1(b) and environmental professionals conducting the inquiry must take into account commonly known or reasonably ascertainable information within the local community about the subject property and consider such information when seeking to identify conditions indicative of releases or threatened releases, as set forth in § 312.1(c), at the subject property.

(b) Commonly known information may include information obtained by the person to whom this part applies in § 312.1(b) or by the environmental professional about releases or threatened releases at the subject property that is incidental to the information obtained during the inquiry of the environmental professional.

(c) To the extent necessary to achieve the objectives and performance factors of § 312.20(e) and (f), persons to whom this part is applicable per § 312.1(b) and the environmental professional must gather information from varied sources whose input either individually or taken together may provide commonly known or reasonably ascertainable information about the subject property; the environmental professional may refer to one or more of the following sources of information:

(1) Current owners or occupants of neighboring properties or properties adjacent to the subject property;

(2) Local and state government officials who may have knowledge of, or information related to, the subject property;

(3) Others with knowledge of the subject property; and

(4) Other sources of information (e.g., newspapers, Web sites, community organizations, local libraries and historical societies).