California Code, Public Utilities Code - PUC § 29223

The chief financial officer shall keep a record of bonds, notes, or other evidences of indebtedness redeemed, and report the redemption to the board.  At the end of each month in which there has been a redemption, a report of the redemption shall be made accompanied by the bonds, notes, or other evidences of indebtedness that have been taken up and canceled or by a certificate of their destruction by any bank or trust company appointed by the board as fiscal agent or paying agent for those bonds, notes, or other evidences of indebtedness and authorized to destroy bonds, notes, or coupons, or other evidences of indebtedness upon payment of them.