Cal. Penal Code § 374.2

(a) It is unlawful for any person to maliciously discharge, dump, release, place, drop, pour, or otherwise deposit, or to maliciously cause to be discharged, dumped, released, placed, dropped, poured, or otherwise deposited, any substance capable of causing substantial damage or harm to the operation of a public sewer sanitary facility, or to deposit in commercial quantities any other substance, into a manhole, cleanout, or other sanitary sewer facility, not intended for use as a point of deposit for sewage, which is connected to a public sanitary sewer system, without possessing a written authorization therefor granted by the public entity which is charged with the administration of the use of the affected public sanitary sewer system or the affected portion of the public sanitary sewer system.
As used in this section, “maliciously” means an intent to do a wrongful act.
(b) For the purposes of this section “person” means an individual, trust, firm, partnership, joint stock company, limited liability company, or corporation, and “deposited in commercial quantities” refers to any substance deposited or otherwise discharged in any amount greater than for normal domestic sewer use.
(c) Lack of specific knowledge that the facility into which the prohibited discharge or release occurred is connected to a public sanitary sewer system shall not constitute a defense to a violation charged under this section.
(d) Any person who violates this section shall be punished by imprisonment in the county jail for not more than one year, or by a fine of up to twenty-five thousand dollars ($25,000), or by both a fine and imprisonment. If the conviction is for a second or subsequent violation, the person shall be punished by imprisonment in the county jail for not more than one year, or imprisonment pursuant to subdivision (h) of Section 1170 for 16, 20, or 24 months, and by a fine of not less than five thousand dollars ($5,000) or more than twenty-five thousand dollars ($25,000).