A Toxic Trail is an investigation-focused quest in ARC Raiders that continues the water contamination storyline on the Dam Battlegrounds map. While the objectives are simple, the quest takes place in a swamp-heavy area with limited visibility and frequent player activity, making awareness and positioning just as important as knowing where to go.
This guide explains each step in order so you can complete the quest efficiently and avoid unnecessary risks.
How to Unlock A Toxic Trail Quest
Before you can start A Toxic Trail, you must complete the quest Source of the Contamination. That earlier mission introduces the polluted barrels and unlocks this follow-up investigation. Once available, A Toxic Trail will always take place on the Dam Battlegrounds map.
Preparing for the Quest
Although A Toxic Trail is not combat-heavy by design, the environment makes it dangerous. The swamp slows movement, limits cover, and places you close to the Central Swamp Lift extraction point, which is often watched by other raiders. Bringing survivable gear and enough healing items is strongly recommended.
If possible, make sure you have a safe pocket slot available. The quest reward is a usable key, and securing it will prevent losing it if you are eliminated before extraction.
Returning to the Water Intake Drain
The quest begins by sending you back to the Water Treatment Center. Your objective is to return to the water intake drain located beneath the Water Treatment Control building. This is the same location where contaminated barrels were discovered during earlier quests.
To reach the drain:
Approach the Water Treatment Center from the north
Move through the surrounding swamp
Look for a drainage pipe outlet near the building’s foundation
You will see contaminated barrels in the water
You do not need to interact with the barrels. Simply step into the contaminated water near the drain and remain there briefly. The objective will update automatically once you are close enough.
Be aware that movement is slowed in the swamp, making this area risky if other players are nearby.
Contaminated drain location
Locating the Source of the Barrels
After completing the first objective, the quest updates and asks you to search the swamp for the source of the contamination. Fortunately, this step does not require long-distance travel.
From the water intake drain, head west while staying within the swamp. Follow the natural flow of the water and keep scanning the open area ahead. After a short distance, you will come across a submerged cargo truck sitting in the swamp. The truck is easy to identify due to the toxic barrels still loaded on its flatbed.
This area is exposed and offers little cover, so take a moment to check your surroundings before approaching the vehicle.
Photographing the Truck
Once you reach the submerged truck, interact with it to take a photo. The interaction is automatic and does not require precise positioning. Your character will capture the image as evidence, confirming that the barrels were deliberately transported and dumped into the water system.
This completes the evidence portion of the investigation.
Submerged truck in swamp
Searching the Truck for Clues
The final objective is to search the truck for clues about who is responsible for the sabotage. Move to the cab of the truck and interact with the door. Inside, you will find the Spaceport Warehouse Key.
This key is not just a quest item. It can be used in future raids on the Spaceport map, making it a valuable reward. If you have a safe pocket available, place the key there immediately to ensure it is protected.
Completing the Quest and Leaving the Area
Once the key is collected, A Toxic Trail is marked as complete. You are not required to extract to finish the quest, but safely keeping the key should be your priority.
You may choose to extract immediately using the nearby Central Swamp Lift or continue looting and extract later. If you decide to leave through the lift, approach carefully. The extraction platform provides very little cover, and other players may be waiting for an opportunity to ambush.
For more ARC Raiders guides, take a look at our walkthrough for completing The Clean Dream quest and our guide to the best Candleberries farming locations.