S.D. Codified Laws § 10-35-1.9
The first year after the environmental upgrade is operational, the original cost of the environmental upgrade, as reported to the agency regulating the coal-fired power plant, is exempt from ad valorem taxation. In the second and subsequent years after the environmental upgrade is operational, the depreciated cost of the environmental upgrade, as reported to the agency regulating the coal-fired power plant, is exempt from ad valorem taxation. Any value that is attributable to the construction work in progress on the environmental upgrade shall be excluded from the assessment process of the owner or owners of the coal fired power plant.
This exemption shall be allocated proportionately, based upon percentage ownership of the coal-fired power plant. However, no coal-fired power plant may have its assessed valuation reduced below its valuation for the year preceding the first year the environmental upgrade is operational.
SDCL 10-35-1.9
This section is repealed effective January 1, 2046 pursuant to SL 2013, ch 51, §2.