Rocks with a high concentration of arsenic were dumped into Lake Lucerne in 2023, on the Uranian side, during excavation work for the Gotthard road tunnel. According to the authorities, there is no danger for the environment.
On Wednesday, the SRF program “Rundschau” devoted an online report to this subject. Alexander Imhof, director of the Uranian Environment Office, confirmed the facts to the Keystone-ATS agency, stressing that arsenic could be naturally present in the rocks.
The canton of Uri wants to renature the lake with materials from the construction of the second tube of the Gotthard road tunnel. Last year, a backfilling test was carried out using the materials, says Thomas Rohrbach, spokesperson for the Federal Roads Office (FEDRO).
For this, 100,000 tonnes were delivered from the tunnel site to Flüelen (UR). According to FEDRO, the checks and analyzes carried out revealed that a delivery of 3,000 tonnes of excavation materials contained arsenic. Those responsible for filling the lake were immediately informed, assures Mr. Rohrbach.
No danger
In the process, the spill was stopped, explains Mr. Imhof. Rocks already placed in the lake were covered with harmless materials. It is unlikely that any plants or animals suffered from arsenic.
A statement confirmed by OFROU, which explains that there is no risk for humans or the environment, whether in the short or long term. Likewise, arsenic has never represented a danger for site employees.
A risk assessment showed that rocks with a higher arsenic content could continue to be dumped into the lake without the limit values being exceeded. However, as this is a renaturation project, the canton of Uri has decided that no materials from the contaminated area should be used.
According to Alexander Imhof, the incriminated rocks come from the Ticino side of the Gotthard. They continue to be stored in Airolo (TI), added Thomas Rohrbach. Infiltration water from the depot will be analyzed for the presence of arsenic.
FEDRO specifies that materials containing arsenic will be permanently stored in Airolo. They will be covered with a layer of coating to avoid contact with air and soil.
This article was automatically published. Source: ats
