California Uniform Plumbing Code Chapter 3 http://www.iapmo.org/Pages/2009UniformCodes.aspx § 306.1 Damage to Drainage System or Public Sewer… ragsor any other thing whatsoever It shall be unlawful for any person to deposit… solids; rags; … oils; grease; or any other thing whatsoever that would, or could, cause damage to the drainage system or public sewer.