All of that assumes the OP is looking for the mutagen reagents' canisters, but I would hazard a guess that they are looking for the hydraulic fluid canisters.
Well, about that, here are all four of them in spoilers (you need three):
1. One is in the locked warehouse in the warehouse block. You need to find a way to power the electronic lock to be able to open the door.
2. In fact, there is another one right there.
3. The Tchortists will reward you with one if you rescue their hostages, which will probably require you to demolish the Faceless camp - I'm not sure if you can do it if you are friendly with the Faceless already, but if you have accepted the mission before talking to their commander they will kill you.
4. A much easier option is just exploring south and west of Caerus Residential (where the statue is), there should be a ruined building with burrowers getting high on hydraulic fluid. Maybe you'll still find some left over.