Remedial Dredging

Remedial Dredging, also known as Environmental Dredging, is undertaken to correct past industrial activities or practices which may have damaged the ambient environment. It involves the careful removal of contaminated material (usually fine grained sediments). This material must be treated and manged in accordance with the local regulations. The main aim of remedial dredging is to achieve the require water depths whilst having a positive effect on the local environment. Accuracy is key to prevent unnecessary overdredging, increasing the quantity of material to be treated/managed. Minimising the suspended sediment from dredging is also essential to prevent the resuspension of contaminants into the water column where they can be dispersed and potentially impact other adjacent areas. The production rates achievable in remedial dredging are much lower than other forms dredging. This is due to the accuracy and turbidity standards required altering the optimum equipment selected.

The Bates Partnership has been involved with numerous remedial dredging projects in recent years. This assistance has included:

• Site investigations to determine the contamination properties;
• Detailed sampling to determine the horizontal and vertical distribution to contamination (minimise volume deemed contaminated);
• Assessment of dredging methods available, their production rates and programme implications;
• Assessment of all dredge material management options ranging from onsite treatment/use to Transfrontier exportation;
• Licensing of the works including ascertaining the environmental mitigation measures stipulated;
• Negotiation with receiving facilities on gate fees;
• Dredging and Transportation Contract Drafting;
• Design of adequate monitoring of the works;
• Onsite Supervision and Contract Management (Project Manager, Engineer or clients rep); and
• Measurement of the works for final account settlement and/or regulatory reporting.

The costs involved with remedial dredging are many orders higher than regular maintenance or capital dredging. Therefore ensure the design, method and management options developed are optimised are critical in ensuring the works undertaken achieve best value for money.

Should you have a project that may involve the management of contaminated material please get in touch with us today to ensure all measures to optimise the project are undertaken from the outset.