It depends, but most likely it will come from Customer Relations after the fact and not from the airport. All the airport is going to do is rebook you and maybe help you with a hotel, transportation, and/or food voucher.
http://www.united.com/page/article/1,,53028,00.html
Overnight accommodations
When circumstances within United's control cause a travel disruption that results in an unplanned overnight stay, United will provide a hotel room and a meal voucher to partially defray expenses related to this inconvenience. Hotels are usually near the airport, and transportation is generally provided by the hotel's shuttle service. If shuttle service is not available, United will provide transportation to the hotel and back to the airport for your rebooked flight.
You should be prepared for the fact that, in some cases, you may be required to bear the expense of an unplanned overnight stay. In the event of overnight travel delays resulting from circumstances beyond our control, such as weather or air traffic control delays, United will provide information to help you book discounted rates (at your expense) at local hotels.
Luggage handling
When you are rebooked for a later flight due to a travel disruption, your luggage will be forwarded to your original destination. If you are delayed, in many situations we cannot retrieve your luggage. Instead we will hold it for the next flight to your scheduled destination. If travel disruptions cause you to have an unplanned overnight stay and we are unable to retrieve your luggage, we will provide you with an overnight amenity kit.
Don't mistake this from VBD compensation.
Standard comp for 1K should be $350 or 15K RDM.
http://www.flyertalk.com/forum/unite...0-edition.html