For about 100 years, gas was produced from coal on site.
Heavy pollutants in the form of benzene and tar remained.
- Virtually the entire gas plant site is polluted.
At the place where the two gas bells stood, the pollutants go very far down.
They go deepest under the small gas bell, down to about eight meters deep.
Excavating so deep involves great risks, says Elke Myrhede, project manager for the environment in the Inner Harbor.
Thermal purification
Therefore, they have chosen to look at a method called thermal purification.
There the pollutants are boiled away.
The ground is heated up to 100 degrees via drilled holes where the pollutants are turned into gas which is then sucked up.
- The purification of the land is necessary to enable housing and other buildings.
SEK 122 million has been budgeted for the decontamination of the gasworks site.
The state accounts for 85 percent of the cost and the municipality for the rest.
- But it will be cheaper.
The project starts this autumn and will be ready in March next year.