Restoration of contaminated soil and landfill sites

The most significant contaminated soil restoration locations managed by the City were the project areas of Kalasatama and Jätkäsaari that were to be transformed into residential use. Additionally, other large restoration sites were in the centre of Vuosaari and Herttoniemenranta. In addition to the large projects, several individual small sites were inspected and restored in 2019. Soil was restored at approximately 40 different restoration locations. 

The soil restoration was usually done during the other construction work in the areas. The soil condition database created by the Ministry of the Environment features the details of 878 areas in Helsinki where research has shown the soil to be contaminated, where the soil has been assessed as being potentially contaminated or where the soil has been restored. 

The restoration of the Vuosaari landfill is underway, and the City is preparing to restore the Iso-Huopalahti landfill in the coming years.

The soil was cleaned in the same way as in previous years, primarily by excavating the soil containing harmful substances and transporting it elsewhere for appropriate processing. Soil was also restored by isolating the contaminated soil matter on site. Below is an overview of how the contaminated soil matter was transported for treatment or final disposal in Helsinki in 2016–2019.

The costs generated by the restoration of contaminated areas and landfill sites increased from the last few years. Below are details of the costs caused by the restoration of contaminated soil and landfill sites in 2016–2019.

A total of approximately 111,000 tonnes of contaminated soil was transferred to be processed or disposed of, which is approximately 20% more than last year.

In 2019, 1,869,600 tonnes of unspoiled excavated earth were used at public construction sites. 192,500 tonnes of unspoiled excavated earth were delivered to external recipients.

Contaminated soil matter transported for treatment or final disposal in Helsinki and the costs for the City of Helsinki caused by the restoration of contaminated soil and landfill sites 2016–2019