S.D. Codified Laws § 10-47B-136.1
A tax report credit for special fuel blended with biodiesel to create biodiesel blend shall be allowed to the licensed blender who performs the blending activity. The tax report credit shall be granted on a per gallon basis in the amount that the rate for special fuel exceeds the rate for biodiesel blend. The credit shall be used to off-set any tax liability resulting from the blending of previously untaxed biodiesel.
This credit is extended only for special fuel which is blended with biodiesel and for no other fuel product. The further blending of additional fuel products with a motor fuel, special fuel, or biodiesel blend as defined under this chapter shall cause this credit to be cancelled and the blended product shall be taxed at the rate of tax for motor fuel and special fuel provided for in § 10-47B-4.
SDCL 10-47B-136.1