A tank that never overflows, never freezes, and always shows a clean bacteriological sample can still be quietly failing its customers — delivering water from one corner of the tank that's days older, and chemically different, than the water leaving from another. At the Class 3 level, storage management stops being about individual checks and becomes about systems: mixing systems, cleaning and inspection programs, and the mechanical and electrochemical equipment that keeps a tank safe and structurally sound over decades of service.
Tank Mixing Systems: Combating Stratification and Short-Circuiting
Two related hydraulic problems drive most water-quality issues inside an otherwise well-run tank:
- Thermal stratification occurs when incoming water is a different temperature (and therefore a different density) than the water already in the tank. Cooler, denser water tends to sink