Water Purification in Uppsala

During my trip to Gamla Uppsala, I stumbled across how drinking water is purified in Uppsala. It's done in a place called Tunasen, which I think is simply a big hill-like structure, on which I took a walk. It was pure chance that I came to the point where the source of water purification begins.

Basically, I can summarise it to three main methods.
1) Mechanical Filtration
2) Biological Trickling Filter
3) Chemical Removal of heavy metals and humus

All are explained in the sign below.

Sign explaining how water is purified in Uppsala

Water is pumped up and allowed to slowly seep into the gound which acts as a mechanical filter.

No wonder the water is so hard. They don't soften the water.

No wonder the water tastes so bad in Uppsala. No doubt the water quality makes it suitable as portable water straight from the taps, but the taste leaves much to be desired.

They ought to properly purify and soften the water before distributing it to the townsfolk. It's amazing how good the water back home tastes as compared to the one here.