News broke earlier this week over the discovery of a large WW2 bomb in Birmingham. With the Aston Expressway and parts of the M6 closed, as well as nearby residents evacuated, a major operation was underway yesterday to detonate what was believed to be 132kg of high explosives (http://www.bbc.co.uk/news/uk-england-birmingham-39939925). The controlled explosion has now been successfully carried out, re-opening motorways and allowing people back into their homes. However, how do you know if your site is at risk from the discovery of unexplained ordnance? REC’s Geo-technical Manager, Colin Wardle, looks into how REC can help.
“Over time, REC has come across several cases of unexploded ordnance (UXO) such as the above, and has had much experience in working through solutions to budget and plan ahead for such occurrences. If you require a site investigation, then UXO will generally be considered within a Phase 1 desk based assessment (typically the first phase of any site investigation). When submitting proposals, REC looks at UXO and Bomb Risk Maps, particularly for areas that were heavily targeted during WWII (Liverpool, Manchester, London etc.). If the area is deemed to be at risk, REC then contracts a specialist organisation to undertake a desk based risk assessment; undertaking a review of their database and assessing if there is significant risk from UXO.
Going forwards, the desk based risk assessment allows you to arrange for an UXO survey to be incorporated during site investigation work and to maintain a watching brief during any intrusive works that break ground (including the earthworks and foundation excavations). If the threat of UXO is known of in advance then the costs to mitigate and to undertake watching briefs can be incorporated into the budget. However, if the UXO is unknown of in advance, then there are of course, increased costs; the logistics of the Birmingham site, for example, will have accrued additional costs with motorway closure, 500m exclusion zone and temporary eviction of residents in that zone.
With over 20 years’ experience and in-house geo-technical specialists, REC can help you prepare and ensure as much as possible that UXO is accounted for in site investigations. REC has undertaken many scopes of works on various WWII targeted sites, as well as sites previously used for target range and construction and testing of Home Guard improvised devices. From experts encountering UXO the size of transit vans, to coming across old Mortars whilst hand digging inspection pits, REC can pre-empt and help you plan ahead.”
Need more advice? Get in touch with our Geo-technical team at firstname.lastname@example.org or ring us on 0845 676 9303.