The South Platte Renew Water Recovery Facility (SPR) is the third largest water resource recovery facility in Colorado. The facility treats approximately 20 million gallons per day of residential and industrial wastewater from 300,000 residents in connecting communities. Due to treated effluent being discharged into the South Platter River, which flows north through the Denver Metro area, the Colorado Department of Public Health and Environment Water Quality Control Commission instituted new limitations to nitrogen and phosphorous levels found in water.

The project focused on upgrades to the plant’s chemical feed system to facilitate compliance with new limits. The scope of work also included the conversion of the existing sodium hypochlorite disinfection system to Ultraviolet (UV) disinfection. The facility previously used oxidation reduction potential to control the disinfection process and chemical dosing, which had been found to cause operational problems. Conversion to the new UV disinfection system drastically decreased chemical usage, offering the client consistent and reliable control over the disinfection process, and effectively meets all discharge permit requirements for disinfection.

The team had a tight budget, a rigid schedule and had to perform work while the facility was still operational. The team worked closely with the plant staff and the design engineer early in preconstruction to develop a conceptual level estimate. The estimate helped identify issues with the City’s budget that had been based on outdated information. Throughout the design process, the project team collaborated with the City and design engineer to provide real-time pricing for different design alternatives, allowing the plant staff to make timely decisions to optimize design and reduce the overall project cost. This process created more control over the budget and schedule while mitigating the potential need for a redesign.

The UV equipment selection served as the basis of the new facility’s design. PCL conducted a competitive bidding process between three UV manufacturers prior to the 30% design milestone. Early selection for the ultraviolet disinfection process equipment kept the project on schedule.  The team also provided estimates for the differences in infrastructure costs associated with each of the proposing manufacturers. As an additional schedule control, the project team used BIM 360 as a quality tool to compare drawings and verify installation prior to the construction of several elements. The time spent in the planning stage helped to save time in the schedule and maintain the project budget.