MODEL RELEASED. Environmental monitoring after fire. Scientists collecting grass samples near the Buncefield fuel depot. This fuel depot, near Hemel Hempstead, Hertfordshire, UK, was the site of a huge explosion and fire on 11th December 2005. The fire resulted in a hot smoke plume that drifted at an altitude of 3000 metres and covered much of South East England. Air, soil and water pollution levels are regularly monitored at and around the site.