Highly variable flow rate — batch discharges or shift-driven production would hydraulically overload a downstream unit sized for average flow.
Highly variable waste strength/concentration — equalization dampens organic-load swings that would otherwise shock a biological process.
pH swings — blending over time reduces the peak chemical dose otherwise needed for neutralization of intermittent acidic/alkaline batches.
Intermittent/batch production schedule — e.g. a weekday-only operation feeding a continuously-operating downstream biological process needs a buffer to bridge the off-hours.
Multiple waste streams of differing character — blending several process streams produces a more uniform combined feed than treating each separately.
Protection against toxic slug loads — the added detention time gives operators a window to detect and divert an abnormal discharge before it reaches biological treatment.
