Jones Edmunds provided professional engineering services for the preliminary design report (PDR), final design, permitting, construction administration, and start-up of a new 6-MGD Modified Ludzack-Ettinger (MLE) wastewater treatment facility to produce reclaimed water for unrestricted public access reuse for the City of St. Cloud. This project was a follow-up to a wastewater master plan conducted by Jones Edmunds to assess the City’s wastewater needs for the next 20 years.
The PDR phase evaluated alternative unit treatment processes for headworks screening and grit removal; alternative biological treatment processes, including membrane bioreactor, oxidation ditch, and MLE; and alternative aeration systems including fine bubble and jet aeration. We conducted workshops with City engineering and operations staff to select the final unit process configurations and equipment. The recommended facility design includes headworks screening using mechanical step screens with screenings dewatering; vortex grit removal and classification; odor control using bioadsorption within aeration-tank-mixed liquor, anoxic/aeration basins, centrifugal blowers, and fine-bubble aeration; three 105-ft-diameter final clarifiers; effluent filtration with disk filters; chlorine disinfection with sodium hypochlorite; and a high-service reclaimed water pump station designed for a peak rate of 20 MGD. The plant design makes it easily expandable to 9 MGD.The plant included a new administration building and reuse of the old Southside WWTF tankage, which was converted into aerobic digesters for storing and stabilizing waste-activated biosolids before dewatering by a new screw-press dewatering system. Jones Edmunds prepared 95% design drawings and specifications and CM-at-Risk RFP documents for selecting a CM-at-Risk contractor. We conducted value engineering with the CM at Risk to reduce the overall Guaranteed Maximum Price for the project. The project received funding under the SRF loan program. Construction of the screw-press dewatering facilities finished in September 2005. Furthermore, construction of the 20-MG reclaimed water pump station finished in September 2006 to meet FDEP requirements and/or receive grant funding from SFWMD grant funding. The 6-MGD expansion began operation in 2008.The City of St. Cloud facility was featured and toured as part of the annual WEFTEC conference held in Orlando in 2009.