California Code, Health and Safety Code - HSC § 116030

(a) The construction standards as set forth in this article and the regulations adopted pursuant thereto, shall not apply to any artificially constructed swimming facility in excess of 20,000 square feet of surface area, including, but not limited to, a manmade lake or swimming lagoon with sand beaches.

(b) The requirements of this article and regulations adopted pursuant thereto, pertaining to the operation, maintenance, and use of a public swimming pool, including the quality and purity of the water, lifesaving and other measures to ensure the safety of bathers, and measures to ensure personal cleanliness of bathers shall apply to the swimming facilities described in subdivision (a).