On August 14, 2009 PSO filed an application for interim rate relief through a rider to collect the carrying charges associated with the incremental capital investment made since PSO’s last rate case. The carrying costs to be collected through the rider are the depreciation, return and taxes associated with the incremental investment. The rider would be adjusted semi-annually. Expenditures submitted would be limited to only those items directly related to serving customers; such as the addition of new power generation, transmission and distribution equipment.