To fortify its wastewater treatment system and fulfill a US Environmental Protection Agency (EPA) Consent Order, the Miami-Dade County Water and Sewer Department commissioned a design-build project for a new, high-purity oxygen production facility at its 143-MGD Central District Wastewater Treatment Plant (WWTP). The project was recently honored by the Cuban American Association of Civil Engineers (CAACE) as a Project of the Year ($25-100 million). Wade Trim led the facility design for electrical, instrumentation and controls, process mechanical, architectural, acoustical, structural, plumbing, HVAC, civil and site work, stormwater, and fire protection. PCL Construction is the Design-Build lead.

The oxygenation process at the WWTP was updated from a cryogenic, liquid-based system to a vacuum pressure swing adsorption (VPSA) gaseous-based system. Two new 90-ton-per-day VPSA oxygen production units will significantly reduce the County’s energy consumption while increasing the reliability of the oxygen production crucial to the WWTP. The updates were designed to improve maintenance and operational access and reduce costs. Another key aspect of the new systems is its ability to start quickly, approximately 30 minutes after a power interruption compared to several days with the existing system.

Considerable existing infrastructure piping traversing the site, along with the plant’s main electrical power line, were relocated to minimize disruption to the WWTP and maintain its treatment capacity during construction. Increased resiliency was a prime requirement given the sea level rise and climate change considerations in South Florida. Critical areas were set above the flood elevation level and designed with structural specifications to withstand a Category 5 hurricane.

Project phasing was crucial to meet EPA deadlines. An early action design and construction package for the foundation segments was developed to allow initial construction elements to proceed while other design elements were completed. Wade Trim’s coordination between 11 firms was integral to reaching each project milestone.

Miami-Dade WASD staff and project team members received the Project of the Year Award on October 16 at the 60th Annual CAACE Engineer’s Day Gala in Miami.