Because this space is literally marginalized, at the edge of and several feet lower than the streets and parking lots that surround it, few people are aware of the pollution that affects it - which means that even fewer are willing to do anything about it. And just to kick it while its down, someone added a pointless chain link fence. The fence straddles a natural moat in between two steep embankments, but I suppose that someone wanted to be absolutely positive that no one would walk from the easily accessible public parking lot on one side to the easily accessible public road on the other side. Of course, the very occasional vagrant blogger is able to scale the fence without much difficulty, but whatever.
In spite of all the concrete encroachments, the polluted runoff from acres of surrounding parking lots, a worthless fence, and the noise and exhaust from the bus station next door, this is actually a pleasant, quiet place. When I walked down to take a closer look at it, I even surprised a muskrat in the water. I encourage more people to visit, especially the tenants of the "green" building next door. If we can make this place less marginal, we can make it less polluted as well.