South Miami Heights WTP Reservoir
and High Service Pump Station, MIAMI, FL
MDWASD opted to have the construction of the finished water reservoir, one of four planned at the treatment plant, and the high service pump building were completed as a stand-alone project, ahead of the overall plant construction, allowing the facility to be temporarily utilized as a remote finished water storage booster pump station for water produced at other treatment facilities. The use of the new finished water storage reservoir and high service pump station in this manner provides increased pressures and reliability to the southern end of the County’s distribution system until the new treatment facility is completed.
The original contract did not include provisions for providing electrical service and the ammonia and chlorine storage and feed systems. MDWASD subsequently authorized P&K for the additional work during the construction period. P&K successfully completed all testing of the reservoir, piping, instrumentation, SCADA and signaling, verifying proper functioning of the facility. More importantly, with the additional scope items, Poole & Kent still managed to provide $530,000 in cost savings to the owner.
SCOPE OF SERVICES
In March 2010, P&K was awarded the contract for construction of the Reservoir and High Service Pump Building. The project included the following components:
- One new 5 million gallon (MG) reinforced concrete finished water storage reservoir tank, measuring approximately 173 feet by 194 feet and 26 feet deep, and buried on three sides
- Four (4) new horizontal split case high service pumps and 500-hp variable speed drive motors capable of delivering approximately 11.3 million gallons per day (MGD) of finished potable water to the distribution system, with space left for a fifth pump.
- A new high service pump building and electrical room to house the new motor control center, switchgear, control panels, lighting panels and supervisory control and data acquisition (SCADA) equipment
- Ammonia and chlorine chemical feed systems
- Yard piping consisting of ductile iron pipe, fittings, valves
- Venturi, magnetic, and turbine flow meters and meter pits.
- Auger-cast concrete piles and concrete mat foundations for the new building and reservoir
- 5-ton overhead bridge crane
- Six roof-top air supply fans, including ducting and accessories for the new pump room
- Two roof-top 17-ton air conditioning units for the new electrical room, including all ducting, supply diffusers, return air grilles and all accessories
- Site work including significant earth berms, planters, retaining walls, and irrigation and landscaping
P&K was responsible for scheduling, coordination, procurement, and execution of all aspects of construction of the facilities and equipment. The heavily reinforced concrete reservoir is essentially buried on three sides and on top, shielding it from the residential neighborhood to the west. Due to the subsurface geotechnical characteristics in the area, a foundation system of auger cast piles was utilized under the reservoir and the building to provide additional support for both structures. Dewatering was extensive and required the use of seven pumps, ranging from 6" to 24", to keep the work areas dry. The project required unusually large concrete pours for the castin- place structures. The approximately 33,500 square foot tank required a two foot slab. Pours were done in 12-hour shifts with P&K crews working overnight to oversee the pours.
Miami-Dade Water and Sewer Department (MDWASD) owns and operates three regional and five smaller, local water treatment plants which supply approximately 313 million gallons of potable water per day to the County’s customers. Plans are under way to construct a new water treatment plant, the South Miami Heights Water Treatment Plant (SMHWTP), in the southern end of the service area to replace the smaller, local plants located nearby.