California Code, Health and Safety Code - HSC § 117010

Every person who washes clothes in any spring, stream, river, lake, reservoir, well, or other waters that are used or intended for drinking purposes by the inhabitants of the vicinage or of any city, county, or town, of this state, is guilty of a misdemeanor, punishable by imprisonment in the county jail for not more than 90 days, or a fine of not less than fifty dollars ($50) nor more than one thousand dollars ($1,000), or by both such fine and imprisonment.

Each day's violation of this section is a separate offense.