Silt removal using de-watering bags
During conventional desilting, a tanker is normally used. The solids to water ratio is around 70-80% water to 20-30% solids.
This can easily translate to 80-90 tonnes of water to remove a single tonne of silt. So when you look at the cost of this, you would be paying for more water to be moved off-site than solids.
Silt de-watering bags are usually used where the pond or lake is situated in a difficult to access location. This is where dredging the silt and placing it in a vehicle, just to remove it from site is impractical.
In these kind of situations we pump the silt into geo-textile bags. The silt is in the order of 80% solids to 20% water, and the bags allow the water to seep through the material whilst retaining all the solids.
For our process you don’t need Floculent, which is a separating chemical. This separates the solid from the water. Therefore this makes our silt pumping methods much more environmentally friendly than other systems.
After a week or two, all that is left in the bag is a stable solid product that can then be taken out of the bags and transported to a different location for composting etc.
Another way silt bags can be used, is as retention for a water body. After 2-3 weeks (when all the water has escaped out of the bag) the remainder can be molded and shaped to form islands or other features in the water body. This is not achievable using any other method.