Clogged with tons of debris accumulated during more than 10 years of inattention, a network of large concrete box culverts posed a threat of flooding for the drainage canals connected throughout the city of Lauderdale Lakes, Fla.
Thanks to an innovative solution that matched up commercial divers with an advanced-technology vacuum truck and a versatile new sewer-cleaning nozzle, the city’s culverts are debris-free and the canals are no longer in danger of overflowing.
Shenandoah Construction of Pompano Beach, specializing in storm and sanitary sewer maintenance and trenchless construction, solved the city’s problem with a combination of ingenuity, skill and technology. The company faced daunting conditions — nearly 20 concrete box culverts from 24 inches in diameter to 6 feet tall by 10 feet wide and up to 150 feet long, all mostly clogged with debris and full of water. The culverts run beneath roads throughout the city, connecting a series of drainage canals that collect and divert surface water.
“Normally, you’d blow debris out of a culvert from one end and pick it up with an excavator at the other end,” says Danny DiMura, vice president of Shenandoah Construction. “The problem is moving the excavator and trucks around in locations where you don’t have much room to operate. It’s time-consuming and not very productive. This seemed like a good place to use our dive team along with a vacuum truck. We were very pleased with the results.”
Tons of debris
Shenandoah used a new Vactor 2100 Plus fan-driven vacuum truck for the project as part of an extended field test of the truck arranged by Environmental Products of Florida, a local Vactor Manufac-turing dealer.
The truck, introduced in early 2009, includes increased vacuum performance, along with improvements in operator comfort and control, air routing and filtration efficiency, and fuel efficiency. Internal monitoring systems enable the operator to monitor and troubleshoot flow and pressure, blower temperature and oil level, drive system idle and open vacuum relief.
For the Lauderdale Lakes job, the truck was equipped with the HydroSurge high-performance cleaning nozzle from Vactor. It uses an adjustable nozzle plate and waterjet inserts with adjustable angles to provide enhanced traction and cleaning performance for handling difficult blockages.
“We talked to Shenandoah about finding a good project as a test for the new Vactor truck and nozzle,” says Paul Hart, south Florida territory manager for Environmental Products. “The Lauderdale Lakes project combined some interesting elements and challenges, and the 2100 Plus proved it could easily handle the job. As we expected, the HydroSurge nozzle performed effectively underwater.”
Shenandoah’s four-man dive team played an integral role in the project, manually guiding the nozzle underwater to clear the culverts. “We entered the culvert at the opposite end from where the vacuum truck was positioned,” says Shaune Rogers, diving superintendent.
“I hand-carried the nozzle and took it right underwater into the material in the culverts. I was using a diving helmet with two-way radio communication to the vacuum truck driver operating the controls. I’d tell him to turn it off or pull it up — basically just give him directions from right inside the culvert. I felt that hand-carrying the nozzle was very safe, and I found it was easy to move the material. It almost felt weightless.”
Rogers emphasized that Shenandoah followed all OSHA safety standards for the dive, including using the required number of divers (three in this case) and a tender (or spotter). “We’re the only vacuum truck operator in the area that uses divers,” says Rogers, who trained for four years as a U.S. Navy diver before starting a commercial diving career 16 years ago.
Efficient and safe
Rogers explains that the dive crews often uses a short, plain PVC pipe attached to a 185-cfm compressor to vacuum material at one end of the pipe and discharge it from the other end. To clean the Lauderdale Lakes culverts, Shenan-doah combined the compressor with the power of the vacuum truck.
DiMura and Rogers agree that the combination of the dive team, vacuum truck and improved nozzle was successful with respect to efficiency, productivity, safety and results. “I have to say, this was really a cool, interesting job,” Rogers says.
During the six-week project, the crew cleaned nearly 20 culverts, including a 150-foot-long culvert that required seven days. The divers worked with up to 100 feet of vacuum hose. Rogers estimates that the crews removed more than 1,000 tons of material.
DiMura gave the Vactor 2100 Plus high marks. “It’s a great all-around sanitary sewer cleaning machine,” he says “It has very good vacuum power, and it’s well designed with a side-discharge port and good placement of the vacuum ports. We were very impressed with how quietly the truck operated.” The test of the HydroSurge nozzle was so successful that Shenandoah will continue using it for all its heavy-duty sewer cleaning projects.
Customized approaches
Shenandoah Construction has provided quality service in the trenchless industry for more than 30 years. The company operates a large fleet of cleaning trucks, seven inspection trucks (four with test and seal capability) and a variety of other mobile equipment. From locations in Pompano Beach, Port St. Lucie and Fort Myers, the company serves customers from Jacksonville to Key West.
The company provides a customized approach to each project it manages for clients, which include municipalities, county governments, property management companies and contractors. Its dive team handles underwater projects including dam repair and the placement of riprap in constructing breakwaters and other underwater walls. The Lauderdale Lakes project was the divers’ first culvert-cleaning assignment.
“For more than 30 years, our focus has been to use the most up-to-date technologies and methods,” says DiMura. “That’s why we wanted to try the Vactor 2100 Plus and HydroSurge nozzle on a difficult and unusual project along with our dive team. It was a successful approach, and one that we’ll use again in the future.”
Frank Ligori is a product manager with Vactor Mfg. based in Streator, Ill.
