Mikkeli is the capital of clean water, where sludge is used to solve water-related problems across the globe

Mikkeli believes in the circular economy of municipal water: it has excavated a test cave near the city’s new water treatment plant, where both companies and researchers can carry out research using the city’s wastewater. This test environment will be used to seek new solutions to the shortage of clean freshwater and the recovery of nutrients from wastewater.

Water shortages in southern Europe have been the subject of numerous headlines, and the lack of clean freshwater has become an increasingly topical issue around the world. Meanwhile, Finland is tackling the challenge of recovering nutrients, such as nitrogen and phosphorus, from its wastewaters. But what role does Mikkeli, a medium-sized city in South Savo, have to play in solving these global problems?

A few years ago, Mikkeli was facing a once-in-half-a-century project: the renovation of the city’s wastewater infrastructure.

The previous treatment plant, which was constructed in the 60s, was long past its prime. This presented Mikkeli with a unique possibility: since it was facing a gigantic undertaking, the city could also seize new opportunities.

“As we were planning the new treatment plant, we saw the headlines about the global freshwater shortages. This inspired us to consider how Mikkeli’s new water infrastructure could help solve these problems,” explains Water Supply Manager Reijo Turkki from Mikkeli Waterworks. He was at the forefront of taking the project forward as the director of Mikkeli Waterworks.

The planning process gave rise to the idea of constructing a test environment in connection with the water treatment plant, where companies and researchers could carry out research using the city’s own wastewater. In addition, the planners wanted the new treatment plant to be able to reclaim water for reuse in industry and other areas, after being purified of nutrients and other substances.

After the project’s plans were complete and approved by Mikkeli’s City Council, it was time to excavate.

Mikkeli is part of the InnoCities network. The city is spearheading its development approach with the circular economy of municipal waters, which it promotes with the Blue Economy Mikkeli (BEM) Centre of Excellence.

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