Mobile Equipment Reduces Phosphorus In Wastewater Effluent

The city of Rosemount, Minnesota, was seeking treatment for phosphorus in the effluent discharge from the city's wastewater treatment plant. The customer's 0.75 MGD facility was permitted to discharge wastewater with a maximum average monthly total phosphorus level of 1.0 mg/l; however the effluent from the facility's newly installed disc filters was exceeding the NPDES permit limit.

Extremely cold winter temperatures was determined as the cause of the problem with total suspended solids (TSS). New disc filters were installed to remove TSS and the associated phosphorus, but soon after the installation, it was determined that the phosphorus concentration had not been reduced.