33 U.S.C. § 2703: Defenses to liability

an act of God; an act of war; exercised due care with respect to the oil concerned, taking into consideration the characteristics of the oil and in light of all relevant facts and circumstances; and took precautions against foreseeable acts or omissions of any such third party and the foreseeable consequences of those acts or omissions; or any combination of paragraphs (1), (2), and (3). A responsible party is not liable under section 2702 of this title to a claimant, to the extent that the incident is caused by the gross negligence or willful misconduct of the claimant. to report the incident as required by law if the responsible party knows or has reason to know of the incident; to provide all reasonable cooperation and assistance requested by a responsible official in connection with removal activities; or without sufficient cause, to comply with an order issued under subsection (c) or (e) of section 1321 of this title or the Intervention on the High Seas Act ( 33 U.S.C. 1471 et seq.). the real property on which the facility concerned is located was acquired by the responsible party after the placement of the oil on, in, or at the real property on which the facility concerned is located; one or more of the circumstances described in subparagraph (A), (B), or (C) of paragraph (2) is established by the responsible party by a preponderance of the evidence; and the responsible party complies with paragraph (3). At the time the responsible party acquired the real property on which the facility is located the responsible party did not know and had no reason to know that oil that is the subject of the discharge or substantial threat of discharge was located on, in, or at the facility. by escheat; through any other involuntary transfer or acquisition; or through the exercise of eminent domain authority by purchase or condemnation. The responsible party acquired the facility by inheritance or bequest. has satisfied the requirements of subsection (a)(3)(A) and (B); has provided full cooperation, assistance, and facility access to the persons that are authorized to conduct removal actions, including the cooperation and access necessary for the installation, integrity, operation, and maintenance of any complete or partial removal action; is in compliance with any land use restrictions established or relied on in connection with the removal action; and has not impeded the effectiveness or integrity of any institutional control employed in connection with the removal action. on or before the date on which the responsible party acquired the real property on which the facility is located, the responsible party carried out all appropriate inquiries, as provided in subparagraphs (B) and (D), into the previous ownership and uses of the real property on which the facility is located in accordance with generally accepted good commercial and customary standards and practices; and stop any continuing discharge; prevent any substantial threat of discharge; and prevent or limit any human, environmental, or natural resource exposure to any previously discharged oil. Not later than 2 years after August 9, 2004 , the Secretary, in consultation with the Administrator of the Environmental Protection Agency, shall by regulation establish standards and practices for the purpose of satisfying the requirement to carry out all appropriate inquiries under subparagraph (A). The results of an inquiry by an environmental professional. Interviews with past and present owners, operators, and occupants of the facility and the real property on which the facility is located for the purpose of gathering information regarding the potential for oil at the facility and on the real property on which the facility is located. Reviews of historical sources, such as chain of title documents, aerial photographs, building department records, and land use records, to determine previous uses and occupancies of the real property on which the facility is located since the property was first developed. Searches for recorded environmental cleanup liens against the facility and the real property on which the facility is located that are filed under Federal, State, or local law. Reviews of Federal, State, and local government records, waste disposal records, underground storage tank records, and waste handling, generation, treatment, disposal, and spill records, concerning oil at or near the facility and on the real property on which the facility is located. Visual inspections of the facility, the real property on which the facility is located, and adjoining properties. Specialized knowledge or experience on the part of the responsible party. The relationship of the purchase price to the value of the facility and the real property on which the facility is located, if oil was not at the facility or on the real property. Commonly known or reasonably ascertainable information about the facility and the real property on which the facility is located. The degree of obviousness of the presence or likely presence of oil at the facility and on the real property on which the facility is located, and the ability to detect the oil by appropriate investigation. any specialized knowledge or experience on the part of the responsible party; the relationship of the purchase price to the value of the facility and the real property on which the facility is located, if the oil was not at the facility or on the real property; commonly known or reasonably ascertainable information about the facility and the real property on which the facility is located; the obviousness of the presence or likely presence of oil at the facility and on the real property on which the facility is located; and the ability of the responsible party to detect oil by appropriate inspection. With respect to real property purchased on or after May 31, 1997 , until the Secretary promulgates the regulations described in clause (ii), the procedures of the American Society for Testing and Materials, including the document known as “Standard E1527–97”, entitled “Standard Practice for Environmental Site Assessment: Phase I Environmental Site Assessment Process”, shall satisfy the requirements in subparagraph (A). In the case of real property for residential use or other similar use purchased by a nongovernmental or noncommercial entity, inspection and title search of the facility and the real property on which the facility is located that reveal no basis for further investigation shall be considered to satisfy the requirements of this paragraph. Nothing in this paragraph or in subsection (a)(3) shall diminish the liability of any previous owner or operator of such facility who would otherwise be liable under this Act. Notwithstanding this paragraph, if a responsible party obtained actual knowledge of the discharge or substantial threat of discharge of oil at such facility when the responsible party owned the facility and then subsequently transferred ownership of the facility or the real property on which the facility is located to another person without disclosing such knowledge, the responsible party shall be treated as liable under section 2702(a) of this title and no defense under subsection (a) shall be available to such responsible party. Nothing in this subsection shall affect the liability under this Act of a responsible party who, by any act or omission, caused or contributed to the discharge or substantial threat of discharge of oil which is the subject of the action relating to the facility.