I chose the second challenge as I already coded for a second pump. I added a "Factory" area in black. When the already pumped water precipitates back to the ground and lands on the factory it's polluted and infiltrates the ground. The pollution is tracked with a data box. I had a graph on there but it kept causing glitches.
My link is: http://www.slnova.org/eriedmayer/projects/161198/
I didn't struggle too much. I was actually working on this while my students were participating in Hour of Code today so they were coding and I was coding. They were really impressed with my abilities. Ha - that's probably a first.