NY does the same thing. My friend just arrived in NY from LA and he said they were handing out mandatory "travel forms" when you got off the plane so the DPH could track you down and make sure you're quarantining. Half of the passengers walked right by without taking the form. Since the penalties are civil, you cannot be detained or questioned about your state of residency or address - you can invoke your right to remain silent as there is no probable cause of you having committed a crime.