Under a Conrail bridge on Emerald Street, 15 tents and 10 mattresses were lined against the cold wall. It's an impromptu setup that feels more permanent by the day, where the denizens stuff foil roasting pans into the sewer to keep rats from overrunning them as they sleep. In the camps on Lehigh Avenue — there are two more under the bridges on Frankford Avenue and Kensington Avenue — more than a dozen people in addiction said they supported having a safe injection site.