In modern landfills, liquid is generated from rainfall and the natural decomposition of debris filtered through it into a wastewater leachate that must properly flow through pipes to a collection system.
The challenge is that particulates in the leachate accumulate over time and solidify within pipes, causing serious clogs and backups that must be cleared to restore flow. One of the most difficult obstructions occurs when limescale, also known as calcite, builds up into a rock-hard substance that is arduous to remove.
Although various methods are available to remove tough blockages, some like chain cutters are well suited to cut through obstructions like tree roots but are not specifically designed to dislodge hardened deposits attached to pipe without damage.
“The leachate in landfill pipe can create material that’s like volcanic rock. I’ve known people that have tried cutters to remove hardened leachate and all it does is tear up the pipe,” said Dan Story, Operations Manager at KEG Technologies, a manufacturer of sewer and storm line products including nozzles, chain cutters and camera nozzle systems.
Instead, a more effective approach developed by the industry is to use specialized, vibratory nozzles that are specifically designed to quickly and effectively remove hardened deposits without damaging the pipe.
“As a modern vibration style nozzle moves through pipe, it is designed to break up even hardened deposits into tiny pieces that flush out with the wastewater. It’s much faster than a cutter and specifically designed to minimize pipe damage,” said Story.
In the case of KEG, the OEM’s vibrating rotational nozzle is called the Duce Nozzle. The rotating nozzle can be particularly effective for removing hardened leachate from landfill pipes.
The special nozzle utilizes water driven rotation and vibration to create a unique “jackhammer” action to remove leachate, as well as scaling, grout/mortar residue, tuberculation or other deposits that have hardened to the pipe floor or wall. This approach is safer, faster and more efficient than cutting and milling out the material.
“The Duce is specifically designed to remove landfill leachate and other deposits that have hardened to the pipe wall or floor such as grout and mortar residue,” said Story.
“KEG Technologies’ Duce Nozzle works extremely well to break up hardened debris,” agreed Bill Benner, Senior Project Manager at Ventilation Power Cleaning (VPC), a Seattle, WA-based firm that provides vacuum truck services to remove various industrial debris in the form of solids, liquids, sludges and slurries.
Contractors can dramatically speed landfill pipe cleaning to prevent clogs and environmental compliance violations using special vibratory nozzles.KEG Technologies
When water conservation is necessary, KEG offers another version of the Duce Nozzle that is purposely designed to be used with recycled water and a recycling truck. The use of a recycling truck facilitates up to 5 more hours of jetting per day since the work crew does not need to retrieve more water every 15-20 minutes. The approach saves water, fuel and vehicle/machine wear.
Although both types of vibratory nozzle can effectively clean hardened materials clinging to landfill pipe, Story advises determining the overall condition of the pipe via camera inspection before use. He also cautions against using the vibratory nozzle in weak or damaged pipe.
“A vibratory nozzle is not recommended for use in clay pipe or in any pipe displaying cracks, fissures or damage,” said Story, adding that the product was nicknamed “Duce” as a warning: “Don’t Use in Clay Ever.”
When landfills must keep their pipes free of obstructions, using a vibratory nozzle can help operators quickly and effectively clear clogs and restore flow. Compared to more aggressive measures like using chain cutters, the approach can ease maintenance, minimize incidental damage to pipe and help facilities remain compliant.