California Code, Government Code - GOV § 39577

The cost of abatement in front of or upon each parcel of land and the costs incurred by the responsible agency in enforcing abatement upon the parcels, including investigation, boundary determination, measurement, clerical and other related costs, constitutes a special assessment against that parcel.  After the assessment is made and confirmed, a lien attaches on the parcel upon recordation of the order confirming the assessment in the office of the county recorder of the county in which the property is situated, except that if any real property to which such lien would attach has been transferred or conveyed to a bona fide purchaser for value, or if a lien of a bona fide encumbrancer for value has been created and attaches thereon, prior to the date on which the first installment of such taxes as imposed by Section 39578 would become delinquent, then the lien which would otherwise be imposed by this section shall not attach to such real property and the costs of abatement and the costs of enforcing abatement, as confirmed, relating to such property shall be transferred to the unsecured roll for collection.