Material excavation and disposal, otherwise known as “Dig and Dump” has fallen out of favour over the past few years. This is due to decreasing disposal limits at landfill sites, new and emergent technologies, and an unwillingness to simply move contamination from one point to another.
However, when used in conjunction with other technologies such as Soil Stabilisation and soil washing, excavation and disposal becomes a more realistic and environmentally sound option.
Our aim is to recycle 95% of materials in order to minimise waste and adopt a more eco-friendly approach. An example of this in practice is the work undertaken in Burgess Hill. Here, we excavated and treated the former landfill site with removal of deleterious waste and the recovery of soils for re-use within the site under a Materials Management Plan. The site met all development requirements and was left to the satisfaction of regulators.
On a much greater scale, our disposal works at Harwell proved to be a huge success. This was the largest nuclear decommissioning and delicencing project in the UK, attracting global interest. As part of the works, contaminated made ground was excavated and bagged into bulk bags. These bags were then assayed in order to determine the waste level, ranging from Out of Scope to Low Level Waste. Any in scope material was kept in storage and repackaged for disposal to nuclear licenced disposal facilities. This site required extensive health and safety measures during disposal due to the hazardous nature of the nuclear waste. Health Physics supervisors ensured that there was no risk to operatives whilst dismantling and removing materials and concrete containing very low levels of radiation. The assay work helped segregate waste streams to ensure that only radiologically contaminated material was taken to nuclear waste facilities.