Recirc tank
Definition
The underground reservoir at a recirculated splash pad that stores water between spray cycles, where chlorine, UV and filtration treatment occur before water is pumped back to features.
Recirc tanks are typically 2,000–10,000 gallon below-grade vaults located in the equipment room or buried near the pad. Drained spray water enters through a screen, settles, gets dosed with chlorine and (modern systems) UV-treated, then is pumped back to the features.
Tank stagnation is the leading cause of recreational water illness at splash pads. Properly designed tanks turn over their full volume every 30–60 minutes during operation.