Description of the job
The area to be treated was the landfill in the Municipality of Siena. This contaminated area contained two main types of waste:
- the first contained shredded waste of different types (wet waste, plastic and urban waste)
- the second was made of dioxin-containing ashes.
Two different codes were used to classify these types of waste
- EWC 191302, which identifies solid waste from remediated areas.
- EWC 170504, which identifies non-dangerous soils, whose dioxin content is below the risk level
The shredded material and the dioxin-containing soil were in different areas.
- Time available was limited and this required careful organisation to removal and dispose of the soils so as to create a continuous flow from removal to disposal. This continuous flow made it possible to optimise the efficiency of machines and eliminate waiting times. The excavation pace produced 600/800 tons of soil per day on average, corresponding to approx. 25 trucks per day. This method made it possible to remove and dispose of all of the material in five months.
- Due to the scope of the job a workers dormitory, changing rooms and shower rooms were set up at the work site,. An office and a workshop were also built for the extraordinary maintenance of vehicles.
A truck wheel washing installation was set up to prevent pollutants from being taken out from the worksite as much as possible . Runoff water was also treated.
Worksite setting up
- Within the excavation area there were several underground utilities, such as gas network and sewage network, whose position was not always clearly defined and this required great attention to prevent damages. This situation caused a slowdown of excavation phases and required the continuous excavation-disposal flow to be adapted in order to avoid waiting times
- Excavation volume: 43,000 m3
- 1 work site manager
- two 1 m3 bucket bulldozers
- one 140 hp tracked excavator
- six 300,000 kg trucks
- Amount of the contract: 1,112,000 €