Identifying a new dredge disposal site

Evaluating the potential for a new deposit ground for the Port of Boston

The Port of Boston has a maintenance dredge disposal licence to deposit silt within the intertidal area of the Wash. Depths at the existing disposal site have naturally reduced, mainly due to channel migration, with time restricting disposal operations to the high water of spring tides. Continued shoaling will soon make access and subsequent disposal too restrictive for maintenance dredge operations.

To continue effective maintenance and operation of the Port, thus meeting its statutory obligations, a new disposal site is needed in a more accessible location.

ABPmer was commissioned to evaluate the potential for a new deposit ground that was viable for the Port’s operations.

Existing Port and public domain information were sourced on the hydrodynamic and sedimentary regime, operational requirements and environmental information to identify potential new deposit ground locations. Use was also made of results from an existing numerical model of the Wash area to enable an assessment of the likely plumes from a typical disposal operation.

These data were compared against pre-licence application consultation responses and environmental designations to provide an initial environmental evaluation of the likely suitability of the shortlisted sites.

This study is the first stage in establishing whether a new deposit location is likely to be acceptable before further detailed characterisation is undertaken.