This Task Order included clean-up of hazardous waste spill of sodium hydroxide at McMillan Water Treatment Plant. The scope included flushing and scraping caustic soda residuals from the interior surfaces of this containment area, which consists of 14 fiberglass tanks; seal containment area to prevent future leaks breaching the containment area; clean caustic soda residue from existing ceiling slab, walls, floors, pipes, and equipment; and install three 3” containment area floor drains and PVC drain piping below the slab and connect them to the primary floor drain. The project was completed while the existing caustic soda feed system remained operational while only partial tank outages occurred.