The Seracon building/plant is situated on St-Patrick st. in PSC. The sprawling building has been abandoned for some time. It was set for demolition back in 2009 where new condos would have been built but the plans have been stopped and it was (still is?) in legal limbo. 2009 article here and 2011 article here. If you ever rode on the Lachine canal bike path, you definitely passed by it.
The Seracon building/plant is highlighted in orange, including the parking lot. Plans for new condos have been put on hold when locals complained that they'd preferred replacing the plant with green space. In a compromise, the deal would have half of the area, from the bridge to rue d’Argenson, become green space while the rest, including the parking lot, be used for the new condo project.