Case Study – Salisbury Plain, Wiltshire

Challenge

In 2017, 1st Line Defence were contacted by White Young Green regarding clearing UXO contamination on a previous Ministry of Defence (MoD) site at Salisbury Plain in Wiltshire.

The site was located near a former military camp, established in the late 1800’s. It was initially a mixture of tents and huts, before permanent barracks were built in the inter-war years. The surrounding areas were used for training exercises of various sorts, and several Army Explosive Ordnance Clearance (EOC) operations have been undertaken across the local landscape over the years.

The main works area was known to have been contaminated with items of Land Service Ammunition (LSA), and items had been found and reported on the site previously. The site area was planned to be developed into new military accommodation as part of wider investment in a local barracks complex.

The client’s brief was to carry out a full inspection of the site to determine whether any UXO risk was present, and if any UXO items were discovered – to manage the land remediation procedure in line with CIRIA C681 guidance.

Process

Stage 1 – Risk Mitigation Strategy

Due to the known UXO contamination on the site a UXO Risk Assessment was not required, however – the site was at a ‘High-risk’ of UXO being present and clearance had to be thorough.

The site required clearance to a depth of 1m and due to the ground conditions and planned works, a UXO Support ‘Search & Clear’ operation was recommended to minimise the UXO risk to as low as reasonably practicable (ALARP).

Stage 2 – UXO Support

Eight UXO Specialists were deployed to the site for a period of several months to systematically ‘Search & Clear’ the areas where development was being planned. Topsoil was sifted, spread out and meticulous searches were carried out using specialist hand-held metal detectors equipped with magnetometer seniors.

During the operation, hundreds of both ‘live’ and ‘inert’ Mortar and PIAT (Projector, Infantry, Anti-Tank) rounds were recovered, and over 80 bags of UXO-related scrap materials were removed from site at the end of the operation.

The ‘live’ ordnance which was found on-site was destroyed by the Royal Logistics Corps (RLC) in controlled explosions, and the ‘inert’ items were safely disposed of by 1st Line Defence. In addition to the ‘live’ items, 2,003 inert PIAT rounds were recovered, and 355 inert parts of 2 Inch Smoke Mortars were found and removed.

Outcome

After four-months of ground investigations, the risk from UXO had been reduced to ALARP status – and the client completed the project without unearthing any additional UXO-related or suspicious items.