Miami-Dade County South District Wastewater Treatment Plant Effluent Pump Station No. 2, Miami, FL
Professional delivery of a newer, safer water treatment system; expert installation of advanced water treatment technology.
To upgrade reclaimed water filtration system, to meet Florida Department of Environmental Protection (FDEP) High Level Disinfection (HLD) reclaimed water standards.
SCOPE OF SERVICES
A new pump station will pump reclaimed wastewater from the County’s new 285 mgd High Level Disinfection (HLD) treatment facility for use as electrical cogeneration cooling water and for irrigation of green space at Zoo Miami (previously known as Miami-Dade Metro Zoo). Due to the fast-track schedule and extraordinary volume of construction performed concurrently on site under other contracts, Poole & Kent’s (P&K) construction contract required extensive planning and coordination with the owner and other contractors.
Separate contracts for two of the largest construction components of this HLD treatment program, a new 285 mgd filtration system, and a 123 mgd capacity effluent pump station, were awarded to the Poole & Kent Company of Florida (P&K). The effluent pump station is discussed herein.
In January 2010, the P&K was awarded the contract for construction of the Effluent Pump Station No. 2. Improvements included under the project comprise the following components:
- Two 15,000 gallon steel surge tank(s)
- A 720,000 gallon cast-in-place concrete effluent wetwell for the effluent pumps
- Six (6) 20.5 mgd capacity, 900 horsepower stainless steel vertical turbine effluent pumps, each equipped with a variable frequency drive (VFD)
- A 12,000 s.f., multi-level pump building to house the pumps, electrical gear, controls, and operating and maintenance equipment. Included all foundation, structural, architectural, plumbing, and HVAC work An electrical room to house the electrical switchgear, VFDs, and instrumentation and controls
- Extensive yard electrical demolition and new construction
- Approximately 550 linear feet of 90-inch, 72-inch, 60-inch, and 42-inch prestressed concrete cylinder pipe (PCCP) and other extensive yard piping, including two 72" x 60"cut-in connections and one 72" x 24" hot tap connection
During construction of the three-story building, Poole & Kent installed a cofferdam with concrete tremie seal. Poole & Kent placed large volumes of concrete including a 3,500 yard tremie placement, 1,500 yard foundation slab, and over 2,000 yards of concrete for vertical walls, beams, columns, slabs, and floor along with precast joists. In addition, the project required secondary concrete placement of vortex pier fillets and baffle walls located in the pump station wet well. Being that the three-story building had to be completely dried within a 12-month time period including masonry, doors, louvers, windows, pre-cast joist, roof and exterior stucco, Poole & Kent management directed its subcontractor to construct all columns and beams and start construction of the roof prior to starting the masonry work. This innovative idea allowed multiple contractors to work concurrently and expedite the construction schedule.
P&K was responsible for scheduling, coordination, procurement, and execution of all aspects of construction of the facilities and process equipment. Due to the high volume of construction work being conducted on the site by other contractors outside of the effluent pump station project (14 other construction contracts were under way concurrently), successful completion of the project required extremely close coordination and cooperation with the owner, engineer and other construction contractors.
In 2004, the Miami-Dade County Water and Sewer Department (MDWASD) entered into a Consent Decree with the United States Environmental Protection Agency which
mandated that the County’s South District Wastewater Treatment Plant be upgraded to incorporate a 285 million gallon per day (mgd) capacity reclaimed water filtration system. In addition, the Decree mandated that the facility meet Florida Department of Environmental Protection (FDEP) High Level Disinfection (HLD) reclaimed water standards, as well as water quality equivalent to primary drinking water standards. This facility will be the largest in Florida to treat wastewater to these stringent standards, and the treated wastewater will be reclaimed for use as electrical cogeneration cooling water and for irrigation of green space at Zoo Miami (previously known as Miami-Dade Metro Zoo). Due to the aggressive completion schedule mandated in the Decree, planning, pilot testing, design, and construction were fast-tracked.