Here's an improvement for you sanitary technicians out there!
Sewer, done by Kal-el's request.
I think can be used to raise city level. But, as always your imagination is the limit how the building can be used. Oh yes, and restrictions in civedit are another limiting factor.
It was bit difficult to decide how to make the icon so I tried this: stonewall strenghened riverbank with two sewer pipe outings, pouring icky stuff to a river.