San Diego public utilities officials said Wednesday that they have implemented most recommendations made by the city auditor last year after thousands of customers were overbilled by faulty meter readers. Some key reforms still need to be implemented, the deputy chief operating officer told members of the city council’s audit committee, and others have yet to be validated by the city auditor. “Eighty percent of the recommendations we have completed, pending auditor review, which is a commitment we made back when the audit was released,” said Johnnie Perkins, the deputy COO tapped by Mayor Kevin Faulconer to oversee reforms at the public utilities department.