I received an email from Tom Gray, former PIO for the CCSD in response to my comments around a simple document describing the Sustainable Water Facility.  I am posting it here (with Tom’s permission) and hope it will be helpful to folks looking for a simple, crisp writeup.

Thanks, Tom for the response!

SWF Writeup – Tom Gray

First, I can give you a quick summary of what the project does and how it does it. Essentially, the SWF is our supplemental water supply, designed both to cover shortages in drought emergencies (which it is currently permitted to do) and to add a third water source to our portfolio of aquifers — San Simeon and Santa Rosa Creek — to provide the more efficient and environmentally sound water production.
The latter function is what we are seeking to ensure in the regular Coastal Development Permit. You can think of it as an optimizing function. A fully permitted SWF, for instance, would allow the CCSD to take more water from the San Simeon Creek aquifer in the summer, so that it can ease up on pumping from the sensitive Santa Rosa Creek aquifer, where subsidence and saltwater intrusions have historically been threats. You might think of the SWF as a relief pitcher. Right now, we can only call it in from the bullpen when the starter is exhausted, the opposing team has the bases loaded with one out in the ninth, and we’re hanging on to a one-run lead. Under the regular CDP, we hope to use the SWF more like a long reliever, stepping in for the starter after six innings to save his arm for his next start and to defend a decent lead.
As for a quick description of the project and how it works, this has been the same from the beginning. It treats water pumped from a well that picks up a mix of treated waste water (from the percolation ponds), ocean-influenced brackish water and fresh ground water flowing from upstream. It treats this through filtration, reverse osmosis and UV sterilization, then pumps it via an injection well to replenish the aquifer where we have our production wells. One difficulty in labeling it is that it does some “desalination” (of the brackish water) but does waste water recycling too. As technology and regulation make more direct re-use of our waste water possible, it may evolve into mainly a recycling facility, with desal just a sideline.
You also may be wondering why the name was changed. The best answer is that the name changed to reflect the next phase in permitting. The original “emergency” permit was always intended — by the County, explicitly in the permit itself — to be just a stopgap until a regular permit was approved. And, as I note above, the facility under the regular permit would be used not only to respond to emergency shortages but to prevent them as well. That, in my view, is why the “emergency” tag was dropped. The “sustainable” label is apt for several reasons. One is the facility’s recycling function, which enables us to make much better use of our limited water resources than we have done before. Another is the environmental enhancement built into the project. Most notable in this respect is its recharge of the San Simeon Lagoon with 100 GPM of fresh water when it is running. Another reason (and this is just my personal opinion) is that the design of the treatment plant is tailor-made for eventual operation from solar power, once the money becomes available.
The SWF and the EWS are the same project, of course. Any new work proposed in the Supplemental EIR is designed to address environmental impacts, especially in the area of brine disposal and the “growth-inducing” effect of having a more secure water supply. The water treatment system remains is the same, with no expansion of capacity.