You are now above the tank in the damaged containment room. Look to the back of the room and you will see a red button. Press it and it will glow blue (as in the picture above). If you climb up on to the ledge above the button via the support struts, you can grab a Health Pack and Tarydium Shards.
Now, if you stand by the button looking back down to the front of the room, you will see two alcoves at the sides of the room. Enter the one on the left to get a Kevlar Suit, Tarydium Shards and a Health Pack. Now go across to the other alcove and you can grab an Energy Amplifier plus more Tarydium Shards. There is a door in this alcove; go through it.
You will now be in a tall but short-ish area with a locked door ahead similar to the one you came through, biowaste in reservoirs underneath, and a lift beyond a pillar with an information panel.
"Lift 2 Status: A broken pipe was reported."
Well, this lift is broken and will not take you up to the top of the tall shaft beyond the pillar. Step on to the LEFT side of the lift though if you want to get some useful gear.
The lift will rise about half way then be blocked by a broken pipe that has fallen across its path. However, if you use your Flashlight, you will see that from this side of the lift you can use the lift clamp as a step to climb up on to the broken pipe. If you walk up the broken pipe you will see that you will arrive between two vertical pipes with rings round them; step on to the rings here and go round the back of the pipes to collect a can of 12 Eightballs and a box of 10 very useful Flak Shells. If you fall off (the lift won't come back down), don't worry, you can drop down from above later.
Anyway, jump back down off the pipes into the biowaste below. Here, once you have killed the Slith swimming around in the gunge, you can grab a Health Pack before climbing back out at floor level. Return to the damaged containment room, and proceed to the front of the room (the far end from the button), where you can come out to an information panel at the bottom of a short flight of steps to a walkway. Read the panel:
"Section C: Status Empty, this Containment Room is damaged, please avoid sending BioWaste here until we can fix it."
Climb the steps out on to the main containment ring walkway. Horizontal beams here yield a Health Pack and a can of 12 Eightballs. This walkway goes round in a circle directly above the empty containment ring below; go a short way anticlockwise to kill the Mercenary on guard here. But don't go any further anticlockwise yet, go instead clockwise until you reach a locked door on the left with the following legend:
"Control Room, ACCESS DENIED"
Horizontal beams here also yield a Health Pack which you can collect if you need it. When you're done, go through the opening opposite the locked door. You will be in a hub room with waterfalls of biowaste pumping out into a vat below; collect Tarydium Shards and a Health Pack from on top of the walkway here.
If you jump into the vat of biowaste and kill the Slith within, you can get a Health Pack from the bottom of the pool. Surface out onto a small platform here and collect another Health Pack and also a Toxin Suit (if you want to - bear in mind that it will replace your Kevlar Suit), then ride the lift back up to the main walkway again.
This room has four exits. Get your bearings by finding the opening by which you entered this room, which has no door, then go through the door opposite this entrance.
You will now be by the entrance to Section B, 90° anticlockwise from Section C by which you initially entered this area. Collect the two Flak Shells and two clusters of 40 Tarydium Shards from the horizontal beams here, then go down the steps to Section B's information panel.
"Section B: Status 48% Full."
Enter Section B and kill the Mercenary that comes running down the central walkway. Looking into the storage tank, you will see that it is about half full.