Indiana Code Title 8. Utilities and Transportation § 8-1-27-17

Sec. 17. If a public utility cancels the implementation of a measure set forth in an environmental compliance plan as a result of an order issued by the commission under section 18 or 19 of this chapter that withdraws the commission's approval of the inclusion of the measure in the environmental compliance plan, the public utility may, absent fraud, concealment, gross mismanagement, or inadequate quality control, recover:

the costs incurred by the public utility in implementing the measure and a reasonable return on the unamortized balance, to the extent the implementation and the costs were approved previously by the commission.  The public utility may not recover costs in excess of the cost estimate approved by the commission under section 8(2) or 13 of this chapter, whichever is applicable, unless the commission finds that the additional costs were necessary and prudent.