For any tax year beginning on or after January 1, 2000 but prior to December 31, 2010, a 20% to 50% income tax credit was available if you redeveloped contaminated land in Colorado.

If you were not able to fully utilize the credit in the year incurred, you were allowed to carryforward the unused portion for up to five years. This credit is no longer available to claim now, but you may claim a credit on the portion of unused carryforward from the credit you claimed during the time period in which it was allowed.

See Colorado Income Tax FYI Publication Income 42 for details on this credit.