The precipitation of struvite (MgNH4PO4.6H2O) is a recurring problem in anaerobic sludge digestion systems. Soluble magnesium, ammonia, and phosphorus (P) released during solids destruction combine to form a hard and tenacious solid that is extremely difficult to remove from equipment surfaces and pipelines. This paper discusses how chemical modeling is being used to help reduce struvite scaling problems in the sludge storage basins (SSBs) at the Sacramento Regional Wastewater Treatment Plant (SRWTP) in California. It also describes bench-, pilot- and full-scale tests conducted to verify model calculations.