Cal. Health & Safety Code § 78700

Any owner of nonresidential real property who knows, or has reasonable cause to believe, that any release of hazardous substance has come to be located on or beneath that real property shall, prior to the sale, lease, or rental of the real property by that owner, give written notice of that condition to the buyer, lessee, or renter of the real property. Failure of the owner to provide written notice when required by this section to the buyer, lessee, or renter shall subject the owner to actual damages and any other remedies provided by law. In addition, where the owner has actual knowledge of the presence of any release of a material amount of a hazardous substance and knowingly and willfully fails to provide written notice to the buyer, lessee, or renter, as required by this section, the owner is liable for a civil penalty not to exceed five thousand dollars ($5,000) for each separate violation.