Excavators are a great tool to remove sediment or muck from a lake, pond, or lagoon. You can work from the shoreline to reach into the water and excavate the sediment. Excavators can also work from barges or mats within the water or mud. Specialized excavators, such as long reach excavators and amphibious excavators, are made to remove sediment from water effectively.
Amphibious excavators have tracks that move over the top of large pontoons. They are driven by hydraulic motors that turn gears at one or both ends of the tracks. The tracks slide along tracks within the pontoons. This allows the amphibious excavator to travel on land, mud, or water.
The best way to determine the amount of silt in a pond or lake is to perform a bathymetric or sediment survey. You can set up a grid with a long tape measure and calculate the volume of sediment along with the depth for a general idea. A GPS or rangefinder with a probe can also be used to estimate the volume. The most accurate method is to have a survey completed by a professional. Otherwise, you may just be guessing until you find out when you dig it out.
Dredging is the solution to removing the silt or muck out of your pond. Silt can be dug out of the pond with an excavator or it can be pumped out with a dredge. Planning for the disposal of the silt is key as it will be sloppy, wet, and difficult to deal with.
CCRs including ash can considerably cut down on the safety and produtivity of coal power plants. Coal ash can be removed through dredging with a cutter head and pump that is connected to a flexible pipe. The material is then pumped to another area for proper settling and dewatering. Mechanical dredging with an excavator can be performed as well. The determination of the best method is often limited by access to the pond or lagoon from the shoreline and where the coal ash or fly ash needs to be disposed of. If the dredge can pump the ash directly into the disposal area, that method may be most effecieint. If the excavator can load trucks along the shoreline or a peninsula for offsite disposal then that method may be the best way to remove coal ash.
Yes, geotextile tubes are a great method to dewater coal ash as it is pumped or dredged from a pond or lagoon. The tubes allow for the material to be safely stored, without the risk of eroding, until the material is dry enough for final disposal.
Dredging is a way to remove ash from a pond. Coal ash or fly ash can be dug with an excavator or pumped with a hydraulic dredge from the pond.
Small hand operated dredges can be purchased for as little as $15,000, but they are only effective for limited types of projects and sediment. The smaller dredge barges can be purchased for $100,000 to $150,000. As you increase in size and effectiveness, most portable dredges cost between $500,000 and $2,000,000. The cost only increases for dredges bigger and with more features extending through the millions and for the largest dredges into the tens of millions. Auxiliary equipment and pipeline are an additional expense that needs to be considered as well in the cost of purchasing a dredge.
Dredging is highly variable in cost. Cost involved for dredging projects are typically as follows:
Costs to operate the dredge include wear parts, labor, fuel, and maintenance. Dredges are unique in that break-downs and maintenance usually have to occur on the water so adequate support personnel and equipment must be available. All of these factors is why dredging cost range from a $3 to $300 per cubic yard. Dredging is often limited by other factors such as dewatering or disposal, so costs can be affected by the entire process as well.
Yes, dredges can be equipped with guides or wheels to protect the auger or cutterhead from damaging the liner while pumping sludge or sediment.
