Section 6020.703 - Defenses to liability(a) Grounds.--There shall be no liability under section 701 of this act for a person otherwise liable who can establish that the release or threat of release of a hazardous substance and the damages resulting therefrom were caused solely by any of the following:(3) An act or omission of a third party other than an employee, agent or contractor of the responsible person or one whose act or omission occurs in connection with an agreement or contractual relationship (except where the sole contractual arrangements arise either from a published tariff and acceptance for carriage by a common carrier by rail, or an exempt circular or transportation contract in lieu of a published tariff for carriage by a common carrier by rail), if the responsible person: (i) exercised due care with respect to the hazardous substance concerned, taking into consideration the characteristics of such hazardous substance, in light of all relevant facts and circumstances; and(ii) took precautions against foreseeable acts or omissions of any such third party and the consequences that could foreseeably result from those acts or omissions.(b) Assistance.--Except as provided in subsection (c), no person shall be liable under this act for costs or damages as a result of actions taken or omitted in the course of rendering care, assistance or advice in accordance with this act or at the direction of the department with respect to an incident creating a danger to public health, safety or welfare or the environment as a result of a release of a hazardous substance or contaminant or the threat thereof. This subsection does not preclude liability for costs or damages as the result of negligence on the part of the person.(c) Government action.--No State agency or political subdivision shall be liable under this act for costs or damages as a result of actions taken by the State agency or political subdivision in response to a release or threatened release of a hazardous substance generated by or from a site.(d) Residential housing.--There shall be no liability under section 701 for the owner of real property which is exclusively used or under construction as residential housing who can establish that the release or threatened release of a hazardous substance and the damages resulting therefrom were caused solely by an act or omission of a third party, other than an employee, agent or contractor of the owner or one whose act or omission occurs in connection with an agreement or contractual relationship, if the owner: (1) at the time of acquisition, did not know and had no reason to know, that a hazardous substance which is the subject of the release or threatened release was disposed on, in or at the site. For purposes of this paragraph, the owner must have undertaken, at the time of acquisition, all appropriate inquiries into the previous ownership and uses of the property consistent with good commercial or customary practice in an effort to minimize liability. The department shall take into account specialized knowledge or experience on the part of the owner, the relationship of the purchase price to the value of the property if uncontaminated, commonly known or reasonably ascertainable information about the property, the obviousness of the presence or likely presence of contamination at the property and the ability to detect the contamination by appropriate inspection; and(2) after obtaining actual knowledge of the presence of a hazardous substance on, in or at the site, exercised due care with respect to the hazardous substance concerned, taking into consideration the characteristics of the hazardous substance, in light of all relevant facts and circumstances and took precautions against foreseeable acts or omissions of any such third party and the consequences that could foreseeably result from those acts or omissions.(e) Limited liability.--Liability under the provisions of section 701 shall not apply to municipal waste transporters for that portion of municipal waste which is defined as household hazardous waste under section 1512 of the act of July 28, 1988 (P.L. 556, No. 101) , known as the Municipal Waste Planning, Recycling and Waste Reduction Act, and which is collected from generators and transported to permitted municipal waste disposal facilities.(f) Burden of proof.--A person claiming a defense provided in this section has the burden to prove all elements of the defense by a preponderance of the evidence. 1988 , Oct. 18, P.L. 756, No. 108, § 703, effective in 60 days.