The SEK898m (£68m) contract involves construction of a 4km wastewater tunnel and access tunnel. The access tunnel will be built at Kontrollvägen in northern Solberga, from which the wastewater tunnel will be blasted and drilled in two directions.

Construction is scheduled to start in December and the tunnel is due to be operational in 2030.

Mässtunneln, commissioned by Stockholm Water, will relieve the city’s wastewater system, enable more residential construction and reduce flood risk.