The West Link in the city of Gothenburg is an 8km-long double-track metro line which includes a 6km-long tunnel allowing for passage under the city of Gothenburg. Scheduled for completion in 2026, the USD 3bn project will also see the creation of three new underground stations.
The construction involves a large amount of tunnelling and concreting, which generates considerable volumes of potentially polluting waters. The contractors, Nordic Construction Company (NCC), are excavating through granite, limestone and clay for the tunnel and stations. During this work the site’s surface water runoff and ground water can come into direct contact with the exposed soil, creating waters with a high concentration of suspended matter including fine, slow-settling, clay particles.
If a significant amount of this material enters nearby drains and watercourses, it can block the gills of fish and smother aquatic plants and invertebrates, starving them of light and oxygen. The extensive concreting works during the construction phases will also create highly alkaline, cementitious construction waters with an elevated pH of 12-13 – akin to oven cleaner; again highly polluting to the environment if left untreated.
Siltbuster’s systems are being used to treat the waters generated during construction. The company’s engineers recommended the use of three integrated iHB40Rs units which remove the solids to less than 25mg/litre of suspended solids, and then neutralise the pH so that the water is pH 7 neutral – meeting the discharge criteria for release to the surface watercourse. Each unit treats approximately 40m3 per hour and an automated monitoring system plus an auto-sampler continually measure and test the treated water, providing NCC with proof of compliance.
Siltbuster’s iHB40Rs units were supplied for the Gothenburg project through its local distributor Clean Water Engineering and will be on site for the next few years with estimated completion in 2026.
This system treats the high incoming flows to a verifiable standard and offers a large treatment capacity for a small footprint. This was a key consideration as the West Link is being developed within the centre of Gothenburg, next to the biggest amusement park in Scandinavia, the Swedish exhibition centre, the World Culture Museum, Gothenburg World Trade Centre plus ice hockey and football stadia. With the construction work taking place in a high profile, densely populated, built-up area, and with a main highway linking Malmo to Oslo running nearby, space is at an absolute premium. There’s limited room on site for additional plant and equipment.
To be involved in yet another prestigious international project is a great endorsement for the expertise of our team, the robustness of our systems, the size of our fleet, our technical back-up and our growing reputation within the world’s construction sector.
