33 CFR §137.55

1. (a)All appropriate inquiries must include a search for the existence of environmental cleanup liens against the facility and the real property on which the facility is located that are filed or recorded under Federal, State, tribal, or local law.
2. (b)All information collected by persons specified in § 137.1(a) rather than an environmental professional regarding the existence of environmental cleanup liens associated with the facility and the real property on which the facility is located may be provided to the environmental professional or retained by the applicable party.