Progressive build-up of silt over time may cause water storage and process dams to reach close to critical volume and an influx of water over the rainy season could have dire implications.

Integrated Pump Rental has alerted operators that desilting of these facilities should be undertaken as soon as possible, in order to accommodate additional rainwater.

“While it is critical to ensure that water storage dams, settlement ponds and similar reservoirs are kept at their required storage volumes at all times, it is just as important to regularly clean and desilt these to avoid any environmental occurrences should these facilities become overfull due to heavy rainfall,” says company MD Lee Vine.

He notes that cleaning these facilities is not always a simple task, as it involves the pumping of high solids materials from the facility being desilted and using the incorrect system or equipment could lead to environmental damage. Application requirements and conditions need to be thoroughly assessed to establish the most efficient and cost-effective desilting options.

“Historically many operations have used manual excavation methods for desilting and cleaning, but our established track record with proven references has proved that this is not only inefficient, but it often fails to remove the required volume of sediment,” he says.

“In some instances, it is possible to pump the high solids material to another nearby dam or reservoir. However, this is sometimes not possible and in this type of scenario we implement an alternate solution such as capturing and storing the content in specialised geotextile bags while the water is separated from the solid material,” he explains.

While the company recommends its SlurrySucker desilting solution, the system needs sufficient volumes of water for it to be floated and if these conditions are not present, a hydro-mining solution needs to be applied.

The SlurrySucker is equipped with a high-performance pump that can move high solids volumes, allowing it to dredge quickly and cost effectively over the full area. Where necessary, monitoring guns are used to blast drier slurry towards the discharge point. Specialised pumps with chopper blades can also be used to dislodge reeds or other plant materials present in the dam.

Locally engineered and manufactured by Integrated Pump Rental, the SlurrySucker is designed to deal with a range of high solids material including coal slurry, general silt and sand. The barge can be operated remotely, further improving safety.