Was planning to cover where the water comes from when you take a hot shower in both South Jersey and West Philly, but I nerded out so hard once I found out how a water tower works that when I sat down to record just the South Jersey part and it ended up being like 45 minutes long so we just went with that.  At the end the West Philly difference is grazed over, but honestly not in great detail.  Low level science got me charged up on this one.