Cal. Health & Safety Code § 25221

A person may enter into an agreement with the department regarding his or her property, or a portion thereof, which provides for restricting specified uses of the property, as determined by all parties to the agreement. Except as otherwise provided in this article, the agreement is irrevocable and shall be recorded by the owner, pursuant to paragraph (1) of subdivision (a) of Section 25220, as a hazardous waste easement, covenant, restriction, or servitude, or any combination of those servitudes, as appropriate, upon the present and future uses of the land. That person shall bear all costs incurred in determining the specific land use restrictions for his or her property, or a portion of the property pursuant to this subdivision.