California Code, Vehicle Code - VEH § 38321

(a) Any person who drops, dumps, deposits, places, or throws, or causes or permits to be dropped, dumped, deposited, placed, or thrown, upon any area, any material described in Section 38320, shall immediately remove the material or cause it to be removed.

(b) If such person fails to comply with the provisions of this section, the governmental agency responsible for the maintenance of the area, or the property owner of the land on which the material has been deposited, may remove such material and collect, by civil action, if necessary, the actual cost of the removal operation in addition to any other damages authorized by law from the person who did not comply with the requirements of this section.