Nine Mile Run

If you're talking about the place of I'm thinking of its in Pittsburgh across from the Homestead waterfront shopping center. If crossing the High Level bridge heading towards town take a right at the first light you come to. I used to live close by; the parking lot you see is about 15 ft above the river so if you're planning on landing something large you'd need a basket.
The mouth and about 200 ft in can be productive depending on the time of year and weather. There's also a paved bike trail which runs along the river starting at the parking lot and goes for about a mile towards town. Good access for shore fishing.

This is called Duck Hollow (Turd Hollow by some).  There is a combined sewage overflow, about 20 yards up stream of the mouth of the creek.  Do not fish, and especially, do not wade, when there are storms forecasted or 2-3 days after a good downpour.  It gets disgusting down there after.
 
That said, when the water hits about 55-60 degrees, the white bass and wipers will show up around the creek mouth.  Small mouth and sauger will be around with the water temps a bit higher.  I think most guys cat fish from the "pier".  I used to live about a mile from there, and fished a lot.  If it is more than a mile or two from your house, it is not really worth a trip.  I wouldn't expect too much from there in the middle of the summer, but who knows.
 
If you are lucky enough to be there soon after the CSO's open, carp line up to bath in the raw sewage, like the Pymie spillway bread line.  Interesting to see, but would suggest not fishing in that filth, until the river has had a chance to wash some of that waste out a bit.

Honestly for fishing in and around the city, Duck Hollow has some of the best and most varied I have come across. Yes, the wall is a pain and yes, it sucks that there is sewage outflow, but I consistently catch fish when I go there. Sauger, smallmouth, gar, bluegill, drum, huge variety and it seems like something is always biting there.