(1)(a) Beginning with taxes levied for collection in calendar year 2006, all personal property located on land owned by the United States, or an instrumentality of the United States, at the Hanford reservation that is used exclusively in the performance of a privatization contract to pretreat, treat, vitrify, and immobilize tank waste under subsection (2) of this section is exempt from taxation.
(b) Beginning with taxes levied for collection in calendar year 2002, and until the application of (a) of this subsection, all personal property located on land owned by the United States, or an instrumentality of the United States, at the Hanford reservation that is used exclusively in the performance of a privatization contract to pretreat, treat, vitrify, and immobilize tank waste under subsection (3) of this section is exempt from taxes levied by the state.
(2) To qualify for the exemption provided in subsection (1)(a) of this section, the personal property must be owned by a person that has a privatization contract to pretreat, treat, vitrify, and immobilize tank waste located at the Hanford reservation. For the purposes of this section, a privatization contract means a contract in which the United States, or an instrumentality of the United States, has designated the other contracting party as a party responsible for carrying out tank waste clean-up operations at the Hanford reservation.
(3) To qualify for the exemption provided in subsection (1)(b) of this section, the personal property must be owned by a person that has, and complies with, a privatization contract to pretreat, treat, vitrify, and immobilize tank waste located at the Hanford reservation. The personal property must be acquired or constructed, and operated, in compliance with the tank waste treatment complex requirements of the Hanford federal facility agreement and consent order, including schedules for tank waste treatment complex start of construction, initiation of hot commissioning, and schedules for tank waste pretreatment processing and vitrification. The privatization contractor shall submit annually, on or before August 1st, a progress report to the Washington state department of ecology documenting compliance with the requirements of the agreement and consent order and the terms of the privatization contract. The department of ecology shall annually issue, on or before October 1st, a determination to the department of revenue indicating whether the privatization contractor is in compliance with the requirements of the agreement and consent order.
(4) An inadvertent use of property, which otherwise qualifies for an exemption under this section, in a manner inconsistent with the purpose for which the exemption is granted, does not nullify the exemption if the inadvertent use is not part of a pattern of use. A pattern of use is presumed when an inadvertent use is repeated in the same assessment year or in two or more successive assessment years.