VOCs and hydrocarbon fumes arising from the handling of contaminated soils are easily detectable below hazardous thresholds as an odour and have potential to cause significant disturbance to nearby residents.
A comprehensive odour management system has been agreed with the Local Authority and implemented to minimise this risk as far as practicable in a residential area where the local community can be found directly on the site boundaries.
Key to this is daily odour assessments which were implemented daily on and around the site. These are used to determine whether there is a disturbance risk to the local community as well as identifying potential odour sources on site for mitigation. Supervisors, engineers and site operatives were trained in the risks associated with this constraint as well as how to undertake an odour assessment; this allows for the quick identification and mitigation of risks on site.
Dewatering in advance of excavation allowed for removal of dissolved phase contaminants through Water Treatment Plant. This resulted in decreased odour risks to the site during this phase of excavation.
An innovative odour management system was procured ahead of the works. A typical constraint of odour neutralising equipment is that is it placed in solution with water and applied as a mist, an aspect that would have impacted working conditions within the excavated shaft. A “dry” odour mitigation system was procured where essential oils were proactively introduced to the face of the excavation and the odour source through the excavation ventilation system.
To date, the site has received no odour complaints associated with the works.