Standard&Poor's Ratings Services affirmed its ratings on Southern California Public Power Authority's (SCPPA) revenue bonds, issued for the Southern Transmission Project (STS). The bonds are payable from rates and charges that the participants' electrical systems provide to their service areas. The ratings reflect: The credit quality of the six California municipal electric systems that are severally obligated to pay STS's debt service; The unlimited step-up nature of the "take or pay" transmission service contracts, which unconditionally require the cities to pay operations and debt service on the project; and The importance of the STS as the only route by which energy generated at the Intermountain Power Project (IPP), a coal-fired generation facility located in Utah, can be conveyed