Treating the groundwater at Malmö's new hospital area
In the heart of Malmö, a new hospital area is emerging, with two profile buildings reaching ten and eleven floors into the sky. Skanska is constructing on behalf of Region Skåne.
The healthcare buildings also extend ten meters below ground in two basement levels. However, six meters down, the groundwater level is reached. Four liters of water per second flow in during the construction of the northern hospital building, which began in the spring of 2018. The water contains chemicals, such as dichloroethane and trichloroethane, which leaked from old dry-cleaning facilities in Malmö.
The client, Region Skåne, was very particular that everything should be done correctly. All pumped groundwater must be treated before being released into the stormwater system. No laundry chemicals are allowed to remain. In this case, no traditional solution with regular sedimentation that only removes turbidity would work.
– It was, of course, a challenge, says production manager Mikael Larsson. No one had done anything similar on this scale.
Reducing the chemical level tenfold
Several companies presented their ideas, including Swedish Hydro Solutions. The fact that purification could take place entirely without the addition of chemicals intrigued both Region Skåne and the environmental department in Malmö.
It sounded a bit strange with the extraction of chitosan from crab shells. But evidently, with newly replaced filters, we are close to getting down to zero. We haven't found any other contractor with a different technique that can do it better. It's impressive to be able to reduce the chemical level tenfold.
— Mikael Larsson, Production Manager at Skanska
Effective water treatment
The pumps are running 24/7. The facility at the northern healthcare building handles 345 cubic meters of water per day. Another facility is being set up, twice as large, to assist in the construction of the southern healthcare building.
Lucas Rådén is the foreman and responsible for the maintenance of water treatment for the northern healthcare building. He shows the chitosan socks, sedimentation tanks, and the square meter-sized filters.
– This is where the magic happens, he says.
Once a day, he cleans the chitosan and filter outlets, ensuring the pump works.
– In the beginning, it was a bit challenging to keep track of all the valves, but you quickly get the hang of it. Now it takes a maximum of half an hour if everything works as it should. And we get help from Swedish Hydro Solutions right away if we need it.
As the person in charge, Lucas Rådén appreciates that the water treatment process is clearly divided into different stages. It is easy to follow what is happening and where there might be a glitch. This makes maintenance more straightforward and smoother.
Water samples are taken every week. And once a month, Swedish Hydro Solutions comes to service the facility. A major service is done every six months, including filter replacements. Production manager Mikael Larsson is very satisfied.
– The word is spreading that we are treating groundwater down here. We are so proud of this!
He is pleased with the high environmental requirements from Region Skåne.
– It's fantastic to have a client who is vigilant, cares, and has the knowledge. We will try to motivate the next client to also handle water treatment correctly.
