1st Line Defence were commissioned to undertake a Detailed UXO Risk Assessment for a new development site in Avonmouth.

The site comprised an open area of marsh adjacent to some major industrial targets. Archival research found that two 250kg HE unexploded bombs were recorded in the south-western end of the site during the war, and that the area was heavily affected by incendiary bombing. It was determined that there was a viable risk that additional UXBs or unexploded incendiary devices may still be present within the site area. Given the ground conditions and shallow nature of the proposed works, it was recommended that a Non-intrusive UXO Magnetometer Survey be undertaken.

A 1st Line Defence survey team undertook a walkover survey of the entire site area. During data processing/interpretation, a number of discreet anomalies were detected in the otherwise clean ground, including higher levels of contamination in the south-west corner. Investigation of these targets resulted in the recovery of a number of partially expended 1kg German incendiary bombs and the base of an anti-aircraft projectile. Pieces of shrapnel were found in the areas of higher ferrous contamination, likely to have been the remnants of the 250kg UXBs which must have been destroyed in-situ. The client was issued with a report stating what had been undertaken and that the risk had been reduced to as low as reasonably practicable.