When wastewater becomes a passion

Water is used for cooling and warming, hygiene and cleaning at Emmi. After use, it flows into the sewerage system as wastewater, meaning that valuable organic substances also leave the Emmi cycle. This is not the case in Dagmersellen, where a resourceful team has found new possibilities for its use. They were rewarded for their efforts with the Emmi Sustainability Prize 2013.

The wastewater treatment plant at the Dagmersellen site is around 25 years old. Because the local municipality was no longer able to manage the wastewater, Emmi was commissioned at the time by the canton of Lucerne to build its own treatment facility. Emmi improved the plant on an ongoing basis. However, odours remained an issue: milk contains sulphur and nitrogen, among other things. The breakdown of the substances produces a strong odour, which neighbours complained about repeatedly.

Tackling the task with enthusiasm

After numerous attempts, the solution was finally found in the biofilter that was meant to clean the exhaust air. Some of the bacteria in the filter were almost inactive - their lives had been wrongly estimated both by the manufacturer and external experts. Only wastewater plant manager Rolf Reichlin, who was appointed in July 2012, and his team managed to track down the problem. Since then, they have been tackling the insides of the industrial wastewater treatment plant with relentless enthusiasm. Rolf Reuchlin laughs: "You could say that dirty water is my passion." The latest strategy succeeded at the start of this year: since then, exhaust air from the biofilter has been fed into a micro gas turbine. This incinerates the very last remaining odour molecules, making the complaints a thing of the past and at the same time generating green energy.

Valuable substances in wastewater

The wastewater specialists pay particular attention to optimal recycling of substances in the wastewater, particularly protein and minerals. This is a project that corresponds perfectly to last year's sustainability motto: "Closing materials cycles". The aim is to reduce wastewater costs while also making use of its valuable contents as fertiliser. The sludge is therefore now taken away by a partner firm and processed into fertiliser and biogas. The rinsed milk and powder residue are passed on as animal feed. But this is not enough for Rolf Reichlin: "We are working on processing the sludge into fertiliser directly on site in the future."

Existing future potential

The wastewater treatment plant in Dagmersellen is currently the only one of its kind in the Emmi Group. Although the water still has to make a detour via the local wastewater treatment plant after being treated, Emmi has been able to build up vast knowledge on recycling waste over recent years. And with the ideas of Rolf Reichlin and his team, we are sure to learn even more in the future.

How much water Emmi uses

Emmi's Swiss facilities use 2.8 million cubic metres of water every year to manufacture their products. By way of comparison, an Olympic-sized swimming pool (50 x 25 x 2 m) holds 2,500 m3 of water. Emmi's annual water consumption would therefore fill 1,120 Olympic-sized swimming pools. If the pools were laid end-to-end, they would stretch 56 kilometres, which is the same distance as the stretch of motorway between Kirchberg (canton of Berne) and Dagmersellen (canton of Lucerne).