This issue concerns a proposal that allows recovery of a Configuration Addition Maintenance Adder cost in addition to the current maintenance costs. This adder is applicable after a major physical change to the unit to meet new environmental compliance requirements. Because maintenance cost calculations are based on a 10- or 20-year history, without the configuration addition adder, these units’ historical averages used to determine maintenance costs will under-recover the expected costs until the full 10- or 20-year historical period is incorporated.