Contanimated Water

[CodFace 0]

Half my city has the contaminated water signs all over and it keeps saying one of my pumps is making people sick, But my water pumping station is on blue land, away from any black and brown land. What gives? 

[Monster's Cat 120]

Are there any water pumps in the polluted area? That you might've placed?

[Grimhood 1]

Or an old water tower?

[galacticwarrior 9]

Furthermore, I think it can happen if you buy contaminated water from another city. Try shutting down your suppliers one by one to see who's supplying you the dirty water.

[tnemelkfoo 4]

dude, when u open the water table data it's just blue and white. blue means there is water. it doesnt mean the water is clean. you have to open the ground pollution data. it will show the brown color which is the polluted areas. it doesnt overlap on the water data. so i bet if u do that, you will see your water pump on a brown piece of land.

[Yaffle 29]

I think if you click near the picture of the water advisor a little ! appears in the bar to the right of him. Double click on that and it should take you to whatever it is causing the problem on your map. It's a bit like the bulldozer tool, double clicking on the icons next to the demolition dude pops you to the next abandoned building/rubble.

As others have said my guess is a forgotten water tower or you are buying it in. If the latter, as suggested, turn that off. If it's your main big water station, you'll have to install the filtration pumps, which purify the water first. They are, of course, more expensive.