Cal. PUC § 29180

The district may prescribe the form of bonds issued pursuant to this chapter, and of the interest coupons attached to those bonds. Bonds shall be signed by the president of the board, or by another member of the board designated by the board by resolution for that purpose, and countersigned by the secretary of the district and the seal of the district shall be affixed to those bonds. The interest coupons on the bonds shall be numbered consecutively and signed by the chief financial officer of the district. The signature on all coupons and one signature on the bonds may be engraved, lithographed, or printed facsimile signature. The seal of the district may be affixed to any bond by mechanical reproduction of a facsimile of the seal. In case any officer whose signature or countersignature appearing on the bonds or coupons shall cease to be an officer of the district before the delivery of the bonds to the purchaser, that signature or countersignature shall nevertheless be valid and sufficient for all purposes, the same as if that officer had remained in office until the delivery of the bonds. If the district appoints a registration agent, fiscal agent, or other agent to authenticate bonds, any bond of the district, whether in coupon or registered form, may be signed by the facsimile signatures of the officers of the district with a facsimile seal of the district affixed mechanically or otherwise reproduced on the bonds, provided that the bonds shall be authenticated by the fiscal agent, registration agent, or other agent appointed by the district for that purpose. Any agent appointed by the district to authenticate registered bonds or exchange bonds of different denominations, or coupon bonds for registered bonds, or vice versa, shall be a bank or trust company authorized to transact, and transacting, business in the State of California or the State of New York.