The Comprehensive Everglades Restoration Plan (CERP) is the nation’s largest environmental restoration project—the repair of Florida’s Everglades. This “River of Grass,” a collection of sawgrass marshes, freshwater ponds, prairies and forests, covered almost 11,000 square miles of South Florida just a century ago. Today it is half that size, drained by agriculture, development and flood control. Essentially, CERP was approved by Congress as a holistic program to restore and sustain hydrological and biological characteristics that defined the original pre-drainage Everglades. The Water Resources Development Act (WDRA) of 2007 authorized construction of the Picayune Strand Restoration project in Southwest Florida.
The Picayune Strand Restoration is partnership between the state of Florida and the Federal government whereby a large portion of the funding for was provided by the American Recovery and Reinvestment Act (ARRA). The project is overseen by the Army Corp of Engineers. The project’s first monumental accomplishment, which illustrates the nature of the partnership that made the project possible, was the Florida Department of Environmental Protection’s acquisition of the thousands of individual parcels of property within the Picayune Strand. This purchase has allowed the project to move forward.
FAKA Union Pumping Station is the second of three new pump stations in the Picayune Strand Restoration project. Because the excavation for each pump station is quite large (300’-500’ x 35’-40’ deep) and dewatering water flow is so high (30,000-100,000gpm), the bid documents stated specifically that the proposed dewatering plan would be a critical element in the evaluation and award of the project. The $79 million FAKA Union Pumping Station project was ultimately awarded to Harry Pepper & Associates (HPA) who has had a long history of success in Florida water management projects. HPA was also awarded the first Picayune project, Merrit Pumping Station. Over the years, Holland Pump has worked on many of HPA’s projects as well and submitted a 128 page dewatering proposal outlining their approach for the FAKA Union Pumping Station project.
There were many dewatering methods contemplated for the project including electric driven deep wells and installation of slurry walls. “Deep wells for this project would have had a high initial cost and delayed the excavation a couple of months. In addition, despite bringing the best science one can to the evaluation of dewatering requirements, the actual flows are less predictable. The FAKA excavation is also deeper and wetter than the previous excavation at Merrit,” said Holland President, Win Blodgett.
Holland Pump’s method was to provide a variety of pump types and models at different stages of the excavation but has relied heavily on Hydraulically Driven Submersible (HDS) systems for which they have manufactured since 1978. “Today most contractors are familiar with Suction Lift Pumps (SLP’s) whereby the “wet end” of is indirectly/directly mounted to the engine but these systems generally rely on priming systems and the pump/pump driver must also be located close to the work because most pumps, particularly pumps with higher flow characteristics really have limited suction lift capability because of NPSHr (Net Positive Suction Head Required),” said Blodgett.
“Hydraulically Driven Submersible (HDS) pumps are often the best choice for high volume low head pumping because they are simply more reliable. The pump head can also be place up to 100 yards from the work which allows the power unit to be high and dry where it can be fueled and maintained easily. The pump head is placed in the water and the pump’s impeller pushes the water to the point of discharge. No priming is required. For the most part, our pumps are much more repairable than cast volute pumps because our volutes and are fabricated from steel plate. They are also more serviceable because if you have a problem with the pump head, you can often just swap out the pump head vs. having to change out the system. So in terms of overall reliability and keeping pumps running 24 hours a day, 7 days a week, HDS is often the way to go,” says Blodgett.
On-site supervision is a critical part to the success of any dewatering job but was even more critical for FAKA Union Pumping Station that is essentially one large excavation. Holland Pump selected Pump Consultant, Mike Cressman for the job.” Mike is probably the most experienced dewatering man in southwest Florida and over the last 20 years has performed hundreds of projects from golf courses to housing developments to multi—story buildings. He is also a good mechanic. My dad used to say, ‘there is no substitute for experience’ and that is proven to be true because a dewatering man with really solid experience has both good judgment and intuition. I believe Mike’s onsite advice literally saved weeks of time on the total project. This is a reason why we continue to get work with HPA and I am sure it assists the project’s bottom line,” said Blodgett.
“Our greatest challenge is also our greatest asset, providing exceptional customer service which is one of the reasons why we are often able to displace our competitors. For example, Holland Pump was not hired at the start of the Merrit Pumping Station project, but we took the project over and have been there the last 16 months,” continued Blodgett.
During the initial stages of an excavation, the land is cleared and a settling pond was created. The pumps are required to pump a lot of sand and trash and as the excavation proceeds the pumpage becomes crystal clear. “Using HDS pump systems allowed the excavation to proceed immediately and to add pumps as needed,” said Blodgett.
For the first months of the excavation Holland Pump relied on up to twenty 14” HDS Trash Pump systems. “Using a number of pumps for a project like this makes sense because you gain redundancy; if one pump fails then adjustments can be made to maintain the dewatering flows required avoiding project holds up and potential disasters,” said Blodgett.
The 14” HDS Trash Pumps were later supplemented by their A22000DS Axial Flow Pump system which provided 10,000gpm at 50TDH. “Right now is this economy it is difficult not only for us but for most of our competitors to build really large pumps because the investment is high and the payback horizon is many months. With the A22000DS we were able to innovate by taking two A22000 pump systems from our fleet and put them in series with the second pump at a higher elevation acting as a booster pump for the first. We tested the idea in Palm Beach County by creating a 50’ tall hill with the same slope as the excavation at FAKA and making sure the pump system would perform as promised,” said Blodgett.
When the bottom of the excavation was reached, large diameter suction lift pumps were brought in. Holland Pump’s PT14TPA 14” Trash Pump features Cornell’s 12NNF and can pump about 6000 gpm at 45TDH. The PT14TPA-D6081A is a wonderful pump for mid-head applications when the suction lift is 10’ or less.
“Because of the 50 CFM diaphragm priming system, the pump primes three times faster than most competitive models and can even overcome small leaks on the suction side. At a depth of 35’ or more, these pumps are more fuel efficient also but it was essential to wait until the excavation was really stable and under control before we brought in these pumps; if there is a major rain or the slope of the excavation is compromised, SLP’s could have been washed in,” said Blodgett.
With some 70 employees with an average of 9 years employment at Holland Pump, 600 pump systems available for rent, and a 40,000 square foot manufacturing facility, Holland Pump will travel anywhere there are major pumping projects required. “Holland has proved over the last 34 years that we can provide turnkey dewatering solutions that help our customers finish faster. When we are successful at accomplishing that it is really satisfying.” said Blodgett.
To learn more about Holland Pump, visit www.hollandpump.com or to speak with Holland Pump Consultant please call our Customer Service Center at 1-888-997-PUMP.