Without looking, I’d guess 100+ years of sewers draining into the river and industrial dumping. Takes a long time to track down every source and clean everything up.
Having read it, this is basically correct. The last hurdle was that the sewer system was designed to use the river to dump overflow in the case of heavy rains. Now they’re finishing up a large reservoir to use instead.
Without looking, I’d guess 100+ years of sewers draining into the river and industrial dumping. Takes a long time to track down every source and clean everything up.
Having read it, this is basically correct. The last hurdle was that the sewer system was designed to use the river to dump overflow in the case of heavy rains. Now they’re finishing up a large reservoir to use instead.