California Code, Health and Safety Code - HSC § 80920

(a) The source of the release of the hazardous substance, or the identity of the party liable for damages in connection with the release or responsible for the costs of removal of the hazardous substance, is unknown or cannot, with reasonable diligence, be determined.

(b) The loss was not compensable pursuant to law, including Chapter 6.5 (commencing with Section 25100) of Division 20, because there is no liable party or the judgment could not be satisfied, in whole or part, against the party determined to be liable for the release of the hazardous substance.

(c) The person has presented a written demand for compensation, which sets forth the basis for the claim, to the party that the person reasonably believes is liable for a loss specified in subdivision (a) of Section 80940 that was incurred by that person and is compensable pursuant to this chapter, the person has presented the Department of General Services with a copy of the demand, and, within 60 days after presenting the demand, the party has either rejected, in whole or in part, the demand to be compensated for a loss specified in subdivision (a) of Section 80940, or has not responded to the demand. Only losses specified in subdivision (a) of Section 80940 are compensable under a claim filed pursuant to this subdivision.