The DND UXO and Legacy Sites Program: Risk Assessment

The DND UXO and Legacy Sites Program identifies all UXO legacy sites and subsequently assesses and manages the UXO risk at each site. The level of risk is determined by assessing the probability of human interaction with the UXO, combined with the probability that such interaction will result in the detonation of the explosive.

Risk varies considerably from site to site depending upon the interplay of these two probabilities. Sites where it is determined that there is little risk of users encountering UXO will be considered as low priority for action, allowing attention to be directed towards sites where risk is greater.

The program carries out two types of risk assessment:

Programmatic prioritization risk assessment is the initial screening process used to designate UXO sites as a High, Medium or Low Risk, based upon the combination of human interaction and explosive probabilities. High Risk sites are the first to be programmed for risk mitigation action.
Site-specific risk assessment determines the level of clearance and the clearance methodology required to mitigate UXO risk to a level that will allow pre-designated property use to take place following clearance.

To aid in the crucially important work of establishing the explosive safety risk, an Explosive Risk Rating Sub-Committee has been formed. The Sub-Committee is made up of individuals with the UXO technical knowledge and experience with military munitions-use required to make highly informed decisions.

Once the level of risk has been determined, it can be mitigated by activities such as:

Property access controls.
On-site warning signage.
UXO clearance.
Education and information programs.

Because of existing technological constraints, it is currently not possible to guarantee that any property affected by UXO will present zero health or safety risk following UXO investigation and clearance projects. Accordingly, the DND UXO and Legacy Sites Program works to reduce risk to acceptable levels commensurate with property use, with a focus on public safety and quality of life.