Due to the in-game map for this area being extremely confusing, and the area being a maze of passages on multiple levels, it is advisable to not rely on the picture too much. You will find yourself trying to go through walls to reach chests.
Location 1 (White Chest)
Upon entering the area, take the path to the left. You will come to an area with Hyperion Soldier-Traps. The chest is behind a large metal pillar.
Location 2 (White Chest)
After the first chest, keep following the pink passages. You will encounter three Crab Worm-Traps. Head through the passage and turn to the right, there is another area with Hyperion Soldier-Traps and Claptraps. The chest is in the house on the right.
Location 3 & 4 (Red Chest & White Chest)
This chest is in the area with Soldier-Traps and a ramp on the cavern wall. The chest is behind one of the houses. The white chest is directly above the red chest, inside the house at the top.
Location 5 (Red Chest)
This chest is up the ramp in the same area as the previous two chests. If the ramp is down, then after this chest, the player can head to Chest 9 directly north. If Phase One has not been completed, you cannot access this chest until you have killed General Knoxx-Trap and have gone through the back door.
Location 6 (Red Chest)
This chest is in the area where you kill Cluck-Trap. There are 3 boulders in the area, the chest is on top of the center boulder, directly infront of the red/green pole.
Location 7 (White Chest)
After killing Cluck-Trap, head out of the area via the east entrance. Go to the left and follow the passage until you get to an area with Soldier-Traps. The chest is on top of a house.
Location 8 (Red Chest)
After killing Cluck-Trap, head out of the area via the east entrance. Go to the left, then to the right into an area with elevated ramps and houses. The chest is located in the southern most house.
Location 9 (White Chest)
The chest is in the west end of the area outside of the back door, past the first bridge, but before the second. This is after killing Knoxx-Trap.
Location 10 (2 Red Chests, 2 White Chests)
These 4 chests are in the control room where the power is turned on in Phase One.
Location 11 (White Chest)
This chest is located in the passage just before the control room. There are lockers and an ammunition crate in the room.
Location 12 (White Chest)
This chest is on one of the buildings before the gate to the power station. It is directly opposite the gate switch, to the west.
Location 13 (Red Chest)
After killing Cluck-Trap, head out of the area via the east entrance. Go to the right across two houses. There will be a house with a red chest inside.