Marine licensing – unexploded ordnance clearance: application guidance

Marine licensing requirements

UXO clearance involves ‘licensable marine activity’, under Part 4 of the Marine (Scotland) Act 2010 and Part 4 of the Marine and Coastal Access Act 2009.

A marine licence is required to carry on a licensable marine activity in the marine licensing area:

• to deposit or use any explosive substance or article either in the sea or on or under the seabed
• to use a vehicle, vessel, aircraft, marine structure or floating container to remove any substance or object from the seabed

It is an offence to carry out (or cause or permit to carry out) licensable marine activities without a marine licence or in contravention of any marine licence conditions.

Deposit or use any explosive substance or article

The following details should be provided in the marine licence application:

• the total number of UXOs to be cleared, location, size and type of each UXO (this should be as accurate as possible)
• the size and type of the donor charge

Where applicants are unable to provide this information (e.g. investigative works of potential UXOs have not yet been undertaken or have not been successful), a summary of the types of UXO that may be encountered should be included in the application. This information can be obtained from the desk-based risk assessment. The applicant should include:

• an explanation of how the number of clearances applied for was determined
• an overview of any surveys undertaken to inform this (e.g. geophysical and magnetometer surveys to identify potential UXOs)

Where investigative surveys for UXO constitute licensable marine activity in their own right, a marine licence will be required. In such circumstances, a two-licence approach is required, where one marine licence is obtained for investigative surveying (if needed) and a second is obtained for the deposit and use of explosive articles during the clearance activity. This will enable a more accurate description of required clearance activities in the marine licence application for clearance activities. 

The specifications of the clearance tool to be used, details of the operator which will conduct the clearance and a detailed method statement covering the use of the chosen clearance tool should be provided. It should also be clear how much explosive material, if used, the clearance tool will contain (Trinitrotoluene (TNT) equivalent weight).  

If multiple types of UXO are required or expected to be cleared, the application should highlight if the type or size of clearance tool may vary with UXO type and whether multiple attempts to clear all the explosive material may be required due to the volume of explosive material contained. The application should include if multiple attempts may be required for other reasons (e.g. for exploratory reasons or due to extensive marine growth on the UXO casing).  

Robust evidence demonstrating the level of noise reduction expected for the chosen clearance tool should also be provided in the application. This information will be important when assessing environmental effects, the outputs of which will determine the level of mitigation and monitoring required. Robust evidence in this instance refers to data and information that clearly demonstrates that the  proposed clearance tool results in reduced  levels of noise being emitted into the marine environment.

Removal of substances and objects

The following details should be provided in the marine licence application:

• details of any planned post-clearance survey
• removal method - for example, using a Remotely Operated Vehicle (ROV) - and whether it requires a container to collect debris  and if so, where will this be located
• the size of area that will be surveyed for debris (radius around the UXO)
• the minimum size of debris that will be collected
• disposal method of debris

In the case of removing objects from the sea following clearance operations, ensuring that all residual material has been removed is considered best practice, regardless of the clearance method used.

It is recommended that removal is carried out as soon as possible after clearance has taken place to minimise risk of chemical contamination to the surrounding water column and this procedure should be described in the application.