Consulting

Yes, dredging and dewatering of all CCRs including fly ash, bottom ash, boiler slag, and flue gas desulfurization, or scrubber, materials such as synthetic gypsum, can be dredged and disposed of properly. 

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:

• Permitting – local, state, and federal are considered in most projects
• Planning – designing engineered plans usually for the dewatering area and disposal
• Mobilization – both of the equipment, the setup for dewatering, and disposal site
• Depth of Sediment – water and sediment depth determine much of the cost involved (i.e. shallow sediment depth takes much more time to dredge)
• Type of Sediment – texture of the sediment determines the type of dredge and dewatering process; debris can add to cost significantly
• Run-times – 24/7 or 5 days for 8 hours; weather is also a major factor depending on the project
• Export and Transport – the time for the dewatering (immediate vs. months) and distance to the disposal area
• Disposal –  the setup of the disposal area and final reclamation; or the tip-fee for a landfill
• Remediation – clean-up of the project site and installation of best management practices

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. 

Water exiting one property and entering another can be necessary but it also may become an issue.  Often a conversation that leads into landscaping and grading for both properties may be the best solution.  Ensuring the proper best management practices are beign used during construction and after can also eliminate erosion and excessive water runoff (check out Georgia’s Manual for Erosion and Sediment Control, the “Green Book” for ideas).  Other resources like your local extension agent, NRCS agent, local issuing authority, and even EPD may be able to offer insight.  If significant erosion is occurring and contributing to sediment ending up in your lake, pond, or stream it may be best to call a professional engineer or environmental consultant. 

Dredging can be done in one of two ways.  Mechanical dredging is done by an excavator or clamshell digging sediment from a reservoir.  Hydraulic dredging is performed by a floating barge with a pump sucking the sediment from the lake bottom and pumping it in a pipeline to another location.