Ground getting polluted by itself?

Question

After logging in to the game, I suddenly found out most of my city ground is getting poluted.

The issue is that, I am running 'green' town, and there was no polution over many days of gameplay, and suddenly lots of it being generated.

Also the polution is in very interesting 'mini squares', please look on screenshots as reference.

Question: Why is my city getting polluted? That makes little sense and completely ruined my city.

More pictures of the situation (fullscreen):

1. Overall ground pollution overlay
2. Air pollution overlay (Bare in mind the Garbage dump would not give me any trouble for the last IRL week of playing this city)
3. Germs overlay (Obviously, as the ground is all poluted)
4. Sewage overlay
5. Water pollution overlay (Notice the stripes!)
6. Garbage overlay (They manage to collect all garbage by around 10PM each day)

All that is happening enormously fast, there was 0 pollution '2 in-game days' ago, and it it keeps growing. I also have filled all the spaces with trees, but the generated pollution is if all those buildings were Processors Factories.

Answer 1

Looking at your water map, it looks like you've been pumping sewage through your water system:

water map http://josh.c-servers.com/web/2013_11_08_15_49_24_SimCity_.png

While placing your water pumps and sewage filtering system next to each other is the way to ensure you don't run out of water, you must replace all of your water pumps with filtration pumps, otherwise you'll just be pumping sewage around your city, which will not only result in massive ground pollution but also make your sims seriously ill.