Not long after you arrive in city 10 you will come to an outdoor area that has a handful of headcrab zombies a few bombs/traps that look like the lambda cashes from half life 2 episode 2 you will jump a fence into an area with a white car with a lambda bamb infront of it turn to the left and you will see a bench and if you look at the ground there is a can pick it up and throw the can into the trashcan next to the bench