Cal. Water Code § 31142.50
(b)
(1) To regulate, prohibit, or control the discharge of pollutants, waste, or other materials in groundwater or surface waters, the district may adopt by ordinance requirements relating to the installation and use of small aboveground or small underground tanks, including, but not limited to, the following:
(c) An ordinance adopted pursuant to subdivision (b) may provide that:
(d) For purposes of this section, the following definitions apply: