More than 10 years of dirt and sludge in an underground storage tank (UST) at Fred’s Citgo station in Albany, N.Y., became suspended when a shipment of ethanol-blended fuel was introduced.
Ethanol, a solvent, released the contaminants, which discharged with the gasoline, clogging dispenser filters every two days and costing station operator Alfred T. Baranello thousands of dollars to replace. Customers, frustrated by the slower dispensing times, began stopping elsewhere.
Baranello contacted Dale Hitchcock, owner of Albany Tank Services Inc. in Ravena, N.Y., who realized that snaking and vacuuming would not solve the problem because the contamination was so extensive. “Those techniques clean only a small portion of the tank bottom, leaving the upper 90 percent untouched,” says Hitchcock. “We needed a method that removed all the contaminants from the tank without resorting to cut and enter, which Fred couldn’t afford.”
This was not Hitchcock’s first contaminated UST, and a better cleaning method was forming in his mind. When he learned about Gamajet Cleaning Systems Inc. in Exton, Pa., he called Michael Delaney, manager of business development, with his idea.
Hitchcock met with Gamajet operations and engineering personnel to develop a rotary impingement cleaner. When Baranello’s call arrived, the prototype was ready for its first field test. The machine cleaned the 12,000-gallon fiberglass tank in 10 minutes without excavation or confined-space entry. Hitchcock promptly bought it.
Down to fiberglass
To facilitate cleaning and lower the gasoline level in the tank, Baranello deferred fuel delivery. Hitchcock decided to use water as a cleaning solution to eliminate the risk of explosion.
“We needed a clean water source, so I converted a salvaged 1,000-gallon tank and added a 50-gpm/130-psi Gamajet portable pump,” he says.
On cleaning day, Hitchcock removed the drop tubes and submersible pumps in the UST, then pumped out the remaining fuel using a 1997 Peterbilt truck with a 5,000-cfm/28-inch Hg Transway pump. He placed a 2-inch suction hose in the lower end of the tank.
“The main challenge was designing a rotary impingement cleaner small enough to fit down 4-inch riser pipes, yet powerful enough to scour the interior of 12- by 30-foot-long vessels,” says Delaney. The Gamajet X did both.
The device is a dynamic head on the end of an adjustable lance. As the head spins, two jet nozzles spray in a 360-degree pattern generated by a rotating tee housing and a nozzle housing. The housings are connected by a set of bevel gears that differ by one or two teeth, causing the lance to index a few degrees with every rotation. Liquid passing through the jets powers the head. “Pneumatic or electric motors can drive it, but the simplest method is media-driven,” says Delaney.
Clean and vacuum
Hitchcock’s crew lowered the Gamajet X through the tank riser using the lance, then connected it to the pump hose. As debris flew off the walls, Hitchcock vacuumed it and the wastewater for proper disposal. A flow rate of 42 gpm/130 psi kept the water from atomizing and kept the pump’s motor at a usable amperage for 120-volt receptacles. Within 10 minutes, the tank was clean. Hitchcock then inspected it with a GE Everest Ca-Zoom camera to verify that it was spotless.
“Regulations requiring greater use of ethanol and ultra-low-sulfur diesel have led to new fuel formulations that are less stable and much more susceptible to contamination and phase separation,” says Delaney. “What happened at this filling station is not an isolated incident. It’s more like the tip of the iceberg.” The fuel distributor arrived that afternoon and the station was back in business.
