Petaluma, CA Public Conduct: Loud Party Ordinance (2026)

030(F) to include owners, tenants, lessees and anyone organizing or controlling the gathering, to take reasonable steps preventing underage drinking: controlling access to alcohol, controlling its quantity, checking drivers' licenses or other government identification, and supervising underage attendees. 050 then makes it unlawful and a public nuisance for a responsible person to knowingly host, permit or allow an underage or unruly gathering where at least one underage person, defined as anyone under twenty-one, consumes alcohol; the section presumes the responsible person knew about the drinking if they were present at any point during the gathering, and a property owner remains a responsible person "regardless of any contract or agreement" purporting to shift that liability elsewhere.

030(I) covers not just underage drinking but a party conducted in a way that substantially disturbs a neighborhood through excessive noise, excessive traffic, street obstruction, fights, vandalism or littering. 060, exempts alcohol use that is protected by the free exercise clause in Article I, Section 4 of the California Constitution. 070 makes that juvenile's parents or guardians jointly and severally liable for penalties and response costs.