FYI, San Diego has a desalination plant that cost about a billion dollars to build and provides water equivalent to that used by 400,000 homes [1]. The lack of the San Onofre plant doesn't seem to be a limiting factor.
Yup! If memory serves, some of the design was borrowed from the San Onofre plans. Certainly only limiting in terms of volume of desalinated water for Orange County. I believe that was the original intent as San Onofre is nicely situated to serve both counties