The on-site liaison has the authority to shut down the event immediately in case of emergency or contravention of the terms and conditions of the approval. With any public event, you must have someone who has this authority, and that person must be available and on site at all times. It is a good idea to have two on-site liaisons, so they can take breaks during the event. Please note that the on-site liaison should also refrain from consuming alcohol while working the event.