On 13 January, the Water Management Authority set up a series of measures to protect against pollution and on Wednesday, its origin was discovered.

Authorities have reported that an oil filter on an industrial site in Belval was severely damaged, resulting in the release of some oil into the sewer and subsequently into the Alzette river.

The company responsible for the site promptly addressed the issue, initiating cleanup measures and repairing the damaged filter. However, the full extent of the environmental impact is yet to be determined.

Since mid-January, there have been multiple instances of pollution recorded in the Alzette near Schifflange and Esch-sur-Alzette, leading to coordinated response efforts by the Water Management Authority (AGE) and the CGDIS. In response to these incidents, an investigation was launched, coming to a halt on Wednesday, February 21 when the origin of the pollution was discovered.