The lime recovery and reuse study was an integral part of the research program undertaken by the Central Contra Costa Sanitary District (CCCSD), California, to demonstrate the reliability of the wastewater treatment system proposed for its 30,000,000 gal/day 11,000 m3/day after reclamation plant. A major part of that research program was the operation of a full-scale 500,000-gal/day-2,500,000-gal/day (2,000-m3/day-9,500-m3/day) Advanced Treatment Test Facility (ATTF), which provided valuable design and operating data on the various unit processes being designed for the CCCSD water reclamation plant.