The Water Treatment Control building on Dam Battlegrounds looks unremarkable from the outside, but it hides one of the most important early locked rooms in Arc Raiders. That room is tied directly to Celeste’s “Greasing Her Palms” quest and the Dam Surveillance key she hands over.
Getting there is simple once you know the route; the real risk is losing your key or wasting time wandering the wrong side of the structure. Here is how the location works, how to navigate the building, and what happens if your key goes missing.
Water Treatment Control building location (Dam Battlegrounds)
On the Dam Battlegrounds map, Water Treatment Control is a named landmark roughly in the middle of the playspace, connected to the main dam structure and the surrounding swampy low ground.
| Reference | What to look for |
|---|---|
| Landmark name | Water Treatment Control on your map |
| Map position | Central dam area, with the locked room on the southern/southeastern side of the complex |
| Visual cues outside | Industrial concrete building with external ramps and multiple floors |
| Common approach routes | From the dam top (drop down), or from the western swamp side |
You can approach from two broad directions:
- From the top of the dam: Move to the edge above Water Treatment Control and drop down to the mid-level with the blue metal stairs and blue railings. This puts you close to the right interior level for the locked room.
- From the swamp / low ground to the west: Work your way in through the lower entrances and climb up until you reach the central floor with the blue-railed staircase.
Enemies around the building are a mix of ground drones, ceiling-mounted “spider” Arcs, and occasional turrets. Clear methodically so you are not forced to sprint through the interior with a quest key in your bag.
How the Dam Surveillance key works for Water Treatment Control
Celeste’s “Greasing Her Palms” quest introduces the Dam Surveillance key. That key is used on a single security door inside Water Treatment Control, and simply visiting the room behind that door is enough to complete the Dam objective for the quest.
| Key detail | Behavior |
|---|---|
| Quest giver | Celeste, through the “Greasing Her Palms” quest |
| Delivery | Granted when the quest is accepted; can appear in your Stash if not in inventory |
| Item name | Dam Surveillance key (used in Water Treatment Control) |
| Usage | Unlocks the Water Treatment Control locked room door once |
| Safety | Can be protected in a Safe Pocket to survive death |
There are a few important behaviors to know:
- The quest completion only checks that you enter the room. The door does not need to be opened by your key. If another raider has already unlocked it in that raid, simply walking inside still updates the objective.
- The key is a physical item. If it sits in your main inventory and you die before extracting, it can be lost, just like any other loot.
- Safe Pockets protect it. Putting the Dam Surveillance key into a Safe Pocket keeps it through death, so you can attempt the run multiple times without farming a replacement.
Path through Water Treatment Control to the locked room
The interior of Water Treatment Control is small but easy to traverse incorrectly because of the ramps and mirrored corridors. Getting to the locked room reliably comes down to two navigation rules: reach the central “blue stair” floor, then stay on the right-hand side.
From the main entrance at mid-level (the door nearest the blue railings):
- Step through the doorway into the interior corridor.
- Take the first right turn.
- Immediately turn right again into a smaller side room.
This second right-hand room is the Dam Surveillance room: a compact control space with monitors and cabinets, and the locked security door that accepts the Dam Surveillance key.
Another way to orient yourself if you enter from an odd angle is to use vertical and color cues:
- Move until you find the central staircase with blue railings. That floor is the correct elevation.
- From that staircase, follow corridors toward the southern/southeastern edge of the building layout. The locked room sits in that corner.
Enemies frequently cling to ceilings or sit behind cover around this area. Clear the room before interacting with the door so you are not interrupted mid-unlock.
Locked room behavior and quest completion
Once you stand in front of the Dam Surveillance door in the Water Treatment Control room, you have two possible scenarios.
| Door state | What you do | Quest effect |
|---|---|---|
| Locked (closed) | Use the Dam Surveillance key to unlock and open the door | Stepping inside completes the Dam objective for “Greasing Her Palms” |
| Already open | Walk into the room and wait briefly | Objective completes even though you did not spend a key |
| Opened by you earlier in the raid | Re-enter the room if needed | Objective remains complete once triggered; re-entry is optional |
The Dam Surveillance room itself is a small, high-value loot area. Expect multiple loot containers, including chests that can roll higher-tier gear. Clearing the space and looting thoroughly can be worth the risk even if you already have the objective completed.
What if you lose or never receive the Dam Surveillance key?
Several problems can interrupt the intended flow of “Greasing Her Palms” around Water Treatment Control.
- You died with the key in your main inventory: the key is gone for that character unless you find another one in world loot or obtain help from another player who can open the door for you.
- The quest shows as active but no key is in your loadout: check the quest details to see if the key icon is listed, and check your Stash; it may have been placed there instead of directly in your inventory.
- The key seems never to have been granted: if the quest text references the Water Treatment Control locked room but your quest log shows no key at all and there is nothing in your Stash, this can indicate a progression bug. In that case, your options are to finish the objective by walking into an already-open door or wait for a patch that resolves missing quest items.
In all of these situations, the door being open is enough to count for the objective. If you can coordinate with other raiders, asking someone with a spare Dam Surveillance key to open the door and let you step inside is often the simplest workaround.
How Water Treatment Control fits into “Greasing Her Palms”
Water Treatment Control is only one-third of Celeste’s “Greasing Her Palms” quest. The Dam Battlegrounds objective is tied specifically to the Dam Surveillance locked room; the other steps send you elsewhere in the Rust Belt.
| Quest step | Map | Objective location | Trigger condition |
|---|---|---|---|
| Step 1 | Dam Battlegrounds | Water Treatment Control locked room (Dam Surveillance room) | Enter the room, door opened by you or another raider |
| Step 2 | Spaceport | Rocket thrusters near the Rocket Assembly / Control Tower A6 area | Remain by the thrusters briefly to “scope out” the site |
| Step 3 | Buried City | Barricaded area on the upper floor of the Space Travel building | Breaching or entering the barricaded rooms on that floor |
Finishing all three visits completes “Greasing Her Palms” and awards crafting materials and a Lure Grenade blueprint. The Dam step is usually the most constrained because of the key requirement and the density of Arc enemies inside the Water Treatment Control building. Once you understand the layout and key behavior, the Dam objective is also the most predictable: reach the blue-railed mid-level, take two rights, and step into the surveillance room.
Handled correctly, Water Treatment Control becomes less of a bottleneck and more of a reliable early-game loot stop whenever you draw the Dam Battlegrounds map.
