By this time next year, Camarillo officials plan to have the architectural designs, the final environmental report and the finances squared away to build a groundwater desalinization plant on a plot of farmland just off Las Posas and Somis roads. The Camarillo City Council voted unanimously Aug. 23 to have the long-planned desalter built on a nearly 5-acre property east of The Church of Jesus Christ of Latter-day Saints on Las Posas Road. Brown and Caldwell, an environmental engineering and construction firm based in Northern California, will be paid about $3 million to design the plant.