Luxembourg sends most of its sewage sludge abroad

Luxembourg produces around 24,000 tonnes of sewage sludge per year, a figure that is expected to rise to 55,000 tonnes per year in the coming years. Most of this sludge is sent abroad, as Luxembourg does not currently have a public facility to burn this waste.

It will be at least ten years before the first plant specialised in dealing with sewage sludge becomes operational in Luxembourg, according to the officials of the Intercommunal Syndicate for Wastewater Treatment in the North (SIDEN). With 150 employees and 35 member municipalities, SIDEN is the largest wastewater treatment structure in the Grand Duchy.

They explain that because of the increasingly fine filtration of harmful compounds, these residues can no longer be used as fertiliser or turned into compost. As a result, for at least the next ten years, the sludge will have to be exported to Belgium or Germany. The distance and cost of this incineration depends on the composition of the sewage sludge.

The more problematic the sludge, the further away the appropriate facilities. The cost of transporting and incinerating waste can range from €160 per tonne in facilities near Luxembourg to €200 or even €250 in sites further away, such as Hanover, Germany.

SIDEN Director Roland Schaack (left) and SIDEN President Aly Kaes. / © Marc Hoscheid

France no longer wants Luxembourgish sludge

While there are some private facilities in Luxembourg, they are not equipped to handle this type of waste. Because of the inconsistency of demand, entire lorries carrying sewage sludge must occasionally turn around since the infrastructure no longer has the capacity. The establishment of a public facility is therefore essential, as those based abroad are unlikely to accept Luxembourg residues for much longer.

Aly Kaes, president of the SIDEN, recounts that at the time "the municipality of Luxembourg City and other actors in the south of the country were exporting their sludge to France until the neighbouring authorities closed the border to this type of export. Luxembourg can therefore no longer ship this waste to France. If Belgium or Germany were to take such a decision, we'd be in big trouble with our sludge pile."

Luxembourg plans to build three to four incineration and recovery plants for hazardous components. Those in charge have their sights set on several locations, particularly where the majority of the sludge is collected. The SIDEN already has two potential sites in mind, either near the Fridhaff roundabout or in Bleesbréck, between Diekirch and Bettendorf.

These new facilities will obviously cost money to build and operate. Due to the increase in energy costs, the annual budget of the SIDEN has risen from €1.5 to €6 million, which is pushing those in charge to turn to alternative energies such as photovoltaics, wind power, or thermal power stations.

Concerns have been raised regarding a possible blackout in light of the situation in Ukraine. A complete power outage would pose a serious health risk to the country.