Cal. Health & Safety Code § 25395.69
(a) “Bona fide purchaser” means a person, or a tenant of a person, who acquires ownership of a site on or after January 1, 2005, and who establishes all of the following by a preponderance of the evidence:
(3) The person is not potentially liable, or affiliated with any other person who is potentially liable, for the release or threatened release at the site through any of the following circumstances: