(a) Notwithstanding any other provision of this part, an owner of property that is the site of a hazardous substance release is presumed to have no liability pursuant to this part for either of the following:
(1) A hazardous substance release that has occurred on the property.
(2) A release of a hazardous substance to groundwater underlying the property if the release occurred at a site other than the property.
(b) The presumption may be rebutted as provided in Section 79800.