Pump Stations Cut Costs for Florida City
The burgeoning suburb of Pembroke Pines, Fla., boasts a forward-thinking motto: “Join Us and Progress with Us.” It certainly fits because the city is one of the Sunshine State’s 10 largest cities. Nestled just west of Fort Lauderdale and north of Miami, Pembroke Pines is full of sun, sand and something most residents probably never think about: wastewater pump stations—nearly 200 of them.
Yet because of the city’s utility pump station philosophy, staff doesn’t have to worry about them either.
Wastewater pump stations in Florida coastal communities are not uncommon, given the topography and population. Pembroke Pines uses above-grade wet well mounted pump stations (WWMPS) by Smith & Loveless .
“Smith & Loveless (pump stations) are the only stations we allow contractors to bring into the city,” said Dan Pringle, the city’s utilities director.
The city standardized on Smith & Loveless stations more than 20 years ago. With its most recent installation of four Classic models, Pringle estimates the city owns and operates more than 180 wet well mounted pump stations.
The cornerstone of the WWMPS concept is the lowest proven cost of ownership throughout the life of the pump station. This stems from several important design attributes. Most noticeable is the above-grade location of all station equipment, including pumps, valves and controls in a compact arrangement above the wet well. This design allows the extreme ease of quick and safe inspection while eliminating all confined space hassles for routine maintenance. That is significant for cities that have numerous pump stations, like Pembroke Pines.
The key to the station’s placement on the wet well is the use of vacuum priming, which creates suction lift in the wet well in order to prime the pumps. A key component of the simple priming process is SonicStart prime sensing, which is a new innovation from the previously used electrode sensor. The adoption of this frequency modulator virtually eliminates the most typical routine maintenance on the station’s pumps.
“We have not touched [the pump] to this day and that was ... I’d say about a year and a half ago.”
The station’s pumps also provide significant savings in energy use and maintenance costs. With efficient motors and high pumping efficiencies, the pumps typically draw less power than alternate pumping schemes. Its vertical pump construction design promotes typical service life of 25-plus years. This includes traits like oversized stainless steel pump shafts (with a minimum of overhang), oversized bearings, bronze seal housing, premium efficiency motors with Class F insulation and trimmed impellers inside the shrouds.
Additionally, removing the entire rotating assembly is simplified: merely removing eight cap screws connecting the motor adapter to the volute facilitates full access to the volute and suction elbow. This gives maintenance staff the ability to perform virtually all pump maintenance and repairs onsite—if desired—without the use of outside contractors or expensive pump maintenance centers. This stands in large contrast to submersible pumps, which typically require special handling and multiple service personnel or an outside contractor.
“You can’t do any maintenance on [submersible pumps],” Pringle said. “You have to pull them up to check them, a very expensive proposition if you try to do that with 185 lift stations.”
The pump stations can save municipalities more than 50% annually on typical life-cycle costs over submersibles, including maintenance and repairs, efficiencies and service life.
Prior to shipment, completed stations are put through factory testing and performance certification. Extensive pump station test facilities replicate actual pumping conditions, including suction lift for vacuum primed stations, and deliver precise data to the customer to ensure proper operation. Once the station arrives to the job site, installation typically requires less than a single day.
Recently, the city discovered that it can perform the entire installation with city personnel instead of hiring outside contractors, saving an estimated $150,000 to $200,000 per installation.