Water that is stored in high volumes (>300,000 gallons) is susceptible to bacteria growth, especially sulfate reducing bacteria (SRB) that are anaerobic and must be removed before using the water. SRBs produce hydrogen sulfide byproducts that are toxic to humans and corrode steel piping and infrastructure.
The practice of heavily dosing the pit water with chlorine dioxide (ClO2) is not able to control SRBs due to the undesirable consequences of the reaction causing iron to precipitate from solution and building a thick sediment of iron on the floor of the pit that becomes a host for SRB colonies. This layer acts to protect the bacteria and biofilm which are not reached by subsequent ClO2 applications. HydroFlow technology was used to recirculate the water in the pits as an alternative to chlorine dioxide, and the water volume of the pit was turned over approximately every 3.5 days.
HydroFlow provided consistent bacteria neutralization between 88%-97%. The energy and equipment used to recirculate the pit cost less than the periodic dosing of ClO2 and no sediments were created, which allowed a higher kill rate of the bacteria in the pit overall.