Environmental remediation

The former Olasfa factory

In 2006, the province of Overijssel commenced with the environmental remediation of the industrial terrain of the former asphalt factory – the Olster Asphalt Factory, ‘Olasfa’ – in the floodplain of the IJssel near Olst. Tar- and oil-like substances have been found in the soil, left behind after the Olasfa stopped producing roofing asphalt and tar products in 1983.

Harvesting the consequences

The severe pollution of groundwater has had a negative impact on the ecology of the IJssel. The province of Overijssel carries out the remediation on behalf of the Ministry of Infrastructure and the Environment and Rijkswaterstaat, amongst others, in order to prevent the pollution from spreading any further. And to prevent future generations from harvesting the negative consequences of their ancestors’ actions.

Remediation through steam

For this project, sustainable remediation techniques will be deployed; for example, the deployment of residual steam from a nearby factory. After having tackled several problems with this innovative technique, this system seems to be working properly now. This is good news, since the project was scheduled to be finished in 2015.


Besides the technical complexity, the environmental management is also an important factor. Because of the longevity of the remediation and the burden on the environment, support for the remediation has slightly diminished. In the near future, special attention shall be paid to the environment with tact and decisiveness.

Triple Bridge’s partner Hans Moll is involved in the Olasfa project as a project manager.