SECTION 1. Subsection (a) of section 5 of Chapter 21K as appearing in the 2006 Official Edition, is hereby amended by adding after the word “release” in each instance it appears, the following words:- “or threat of release”

                SECTION 2. Subsection (f) of Section 5 of Chapter 21K as so appearing, is further amended by striking said section in its entirety and inserting in its place, the following section:-

                (f) Any person who owns or rents and occupies a family residence that is an emergency response site at which the department has incurred emergency mitigation responses costs for the release or threat of release or oil or hazardous materials, shall not be liable to the department for those costs if he can establish by a preponderance of the evidence that:  (1) he is not a person described in clauses (3) or (4) of subsection (a); (2) the site was being used exclusively by him as a family residence at the time of the release or threat of release; and (3) the owner or renter of the family residence did not unlawfully possess, store or use such oil or hazardous materials in violation of law; and (4) said owner or occupants conduct was not grossly negligent in causing the release or threat of release of oil or hazardous materials and; (5) said owner or occupant immediately notified the local fire department of the release or threat of release of oil or hazardous materials as soon as he had knowledge of it.