Miami Dade Water and Sewer’s first vacuum pressure swing adsorption (VPSA) system at the Central District Wastewater Treatment Plant significantly reduces Miami-Dade County’s power consumption while generating the same amount of oxygen used before. The VPSA oxygen production units replace a cryogenic oxygen system and help Miami Dade County meet new environmental guidelines set by the U.S. Environmental Protection Agency and the Florida Department of Environmental Protection. The newer technology will produce pure oxygen for the plant more efficiently and cost effectively.
The overall design of the new plant did not consider all existing infrastructure, nor did it plan for future construction. Therefore, PCL relocated existing electrical duct banks to free up the footprint of the new facility. We gathered all subsurface utility elevations and entered this information into the building information model to confirm the new plan would work. The team were also able to adjust the location of the future oxygen building in a way that lessoned the impact of underground utilities on plant operations.
Above ground were a couple of other details to set right. Under the electrical building slab were exposed conduits, so our design-build team used concrete hardening to protect the electrical service during storms. It was also determined that a proposed four-inch elevated slab under the process area was likely an entry point for rodents and other pests and could become a maintenance issue. PCL's team used a solution provider mentality to create the solution of backfilling this space and instead poured the process area slab as a slab-on-grade to alleviate this concern.