The WRRF's (Water Resources Recovery Facility) final phase of construction has been completed and is now online. The 50% plant expansion provides for the City’s rapid population growth. It has a permitted design flow capacity of 20 million gallons per day (MGD).
The WRRF provides primary treatment through the use of fine step screens and vortex grit removal. Secondary treatment is a carefully controlled multi-stage biological process that includes various microorganisms metabolizing ammonia ultimately into Nitrogen gas and other microorganisms accumulating Phosphorus. This takes place in anoxic basins for denitrification, oxidation ditches which utilizes an extended aeration process for nitrification, and six final clarifiers. The effluent from the biological process is passed through thirteen deep-bed sand filters for the removal of fine solids and then disinfected with ultraviolet light. Lastly, the effluent is oxygen enriched by submerged aerators.
In 2001 the Murfreesboro WRRF was recognized by the Greater Nashville Regional Council with the Local Government award for Excellence in Wastewater Facilities and by the American Council of Engineering Companies of Tennessee with the Engineering Excellence Award. In 2011& 2015 the plant received the Tennessee’s Beneficial Reuse of Effluent Award from the Kentucky-Tennessee Water Environment Association. In 2015 MWRRF received the Outstanding Performance Award (or “Plant of the Year”) from The Tennessee Water and Wastewater Association. MWRRF will receive the Operational Excellence Award 2018 at the Kentucky-Tennessee Water Professionals Conference for the sixth year in a row.