In In re Pacific Gas and Electric Company (1993) 48 Cal.P.U.C.2d 430, PG&E was required, pursuant to a state agency consent order, to perform hazardous waste cleanup. PG&E filed an advice letter requesting approval of a memorandum account to record the costs, but the PUC did not act on the advice letter for approximately eight months. During the interim, PG&E was required to perform some of the cleanup work. However, the PUC disallowed inclusion in the memorandum account of expenses incurred prior to the date of the resolution approving it, even though PG&E protested that the PUC had failed to act on its advice letter in a timely fashion. ( Id. at pp. 433-434.)