Conn. Gen. Stat. § 7-498

Any development property may be exempted from any property tax imposed by the municipality; provided any municipality may enter into an agreement, approved by resolution, providing for a payment or payments in lieu of taxes with respect to any such property, or providing that any such property is subject to all or any portion of local property taxes. In no case shall development property be exempt in whole or in part from such property tax for a period or periods, in the aggregate, in excess of twenty years. This section shall not affect, modify, alter or invalidate any agreement entered into by any municipality prior to August 8, 1975, relating to local property taxes to be paid on any municipally owned property.