(a) Throughout the inquiries, persons specified in § 137.1(a) and environmental professionals conducting the inquiry must take into account commonly known or reasonably ascertainable information within the local community about the facility and the real property on which the facility is located and consider that information when seeking to identify conditions indicative of the presence or likely presence of oil at the facility and the real property.

(b) Commonly known information may include information obtained by the person specified in § 137.1(a) or by the environmental professional about the presence or likely presence of oil at the facility and the real property on which the facility is located 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 § 137.30(a) and (b), the person specified in § 137.1(a) 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 facility and the real property on which the facility is located; 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 facility and the real property on which the facility is located.

(2) Local and state government officials who may have knowledge of, or information related to, the facility and the real property on which the facility is located.

(3) Others with knowledge of the facility and the real property on which the facility is located.

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