Cal. Health & Safety Code § 25174.8.1
(a) The fee provided for in Section 25205.5 does not apply to any of the following:
(1)
(A) Hazardous waste that results when a governmental agency takes a removal, remedial, or corrective action to address a release of a hazardous substance caused by a person other than the governmental agency that takes the action if both of the following conditions are met:
(4)
(6) Hazardous waste that is generated onsite and meets both of the following conditions: