Working Group on managing UXO's and associated risks in coastal and nearshore projects
Introduction
During WW1 and WW2 and shortly afterwards bombs, grenades, mines, and many other types of ammunition were dropped, planted or dumped, and failed to detonate (at the time and since then). Both on land and at sea hotspots with high density of Unexploded Ordnance (“UXO”) potentially capable of exploding are known, whilst in other areas the probability of encountering such objects are less clear.
The immediate danger of UXO’s is clear: detonation upon mechanical impact, and the demolishing impact on equipment, humans, and nature nearby. Besides detonation upon impact, there is also the danger of environmental contamination from leakage due to degradation of munition casings.
However, the risk of UXO’s (presence, explosive capacity, actual state) is far from clear, because of the many uncertainties involved, i.e.:
- Locations where UXO have been planted, dumped or dropped are unclear due to inaccuracy of records and a constantly shifting environment;
- The likelihood of encountering ordnance, depends primarily on the combination of two factors: Presence of ordnance at a certain site (which is a statistical parameter), and 2. The extent of the dredging/digging operations for a project (both horizontal and vertical) ;
- Identification of targets as being a UXO, including the type/size and burial depth of the object in the seabed, is difficult even with the most advanced geophysical methods, whereas some dangerous ordnance cannot be found by these investigations;
- Many decades after being dropped, dumped or planted, the state of the ordnance, especially the potential to actually explode, is often difficult and sometimes impossible to ascertain beforehand;
- Human activities to investigate, in a marine environment, the presence and state of targeted objects which may be UXO, are not only costly but also involve significant dangers and risks;
- Construction work for coastal and nearshore projects (for instance trenching, dredging, pile driving, etc) implies physical disturbance of the seabed and the UXO’s encountered. Type, size and state of the UXO will determine whether this could result in an explosion, the extent of the explosion and the consequences thereof. Both the probabilities and the consequences thereof show very wide ranges.
Consequently, dealing with this risk is a difficulty for project owners preparing for coastal or nearshore projects. It is not only a technical/numerical problem, but also involves ethics as to how much resources the owner should apply to (partially) reduce risks, and/or conscientiously allocating risks to contractors.
Legislation regarding UXO and safety protocols are primary national and have been noted to differ considerably, so for identical problems different practices may be applied in various countries, which are not necessarily optimal. Also the advise of experts is known to vary widely, which may be partly explained by commercial bias.
For many non-UXO-specialists involved in coastal and nearshore projects, the many uncertainties in detection and characterisation of UXO’s, as well as the risks involved, are not well known or understood. More general, UXO’s instil emotion (fear, uncertainty), and this in itself can be an obstacle to a rational approach.
CEDA and HSB/IFHS have decided to establish a Working Group (WG) to prepare an information paper on the subject. The paper is to provide a structured overview of key uncertainties and risks, available investigation techniques, practices, (national) responsibilities of all parties, liabilities and legislation. A qualitative analysis of the options for risk mitigation is to be included, with quantitative examples when possible.
Case studies should provide examples how the problem is approached in practice.
CEDA and HSB/IFHS propose the following Terms of Reference for the Working Group. The TOR will be formally established by the Working Group at their first meeting.
Objectives of the WG
The objective of the Working Group is to provide a structured overview of options to detect, assess, manage, and mitigate risks in coastal and nearshore projects regarding planted, dumped or dropped UXO, with recommendations how to plan and execute a project safely and efficiently regarding these risks.
Terms of reference
Please see the draft TOR under "related documents" below.