For state law authorizing cities to regulate construction, etc., of sewers, see Gov. Code § 38660. See also Gov. Code §§ 38900, 39000 et seq. As to sewers generally, see Health & Saf. Code § 4600 et seq. As to director of public works, see §§ 2-22--2-24 of this Code. As to plumbing regulations, see Ch. 7. As to lavatory facilities for restaurants, see § 27-11. As to design standards for sewage disposal in subdivisions, see § 31-33. As to sewage disposal improvements in subdivisions, see § 31-42. As to water generally, see Ch. 25.