The player can find the entrance to the sewers near the path leading to the Radio Tower and Wasted Garage, just north of the Outrigger Settlement. When approaching the path, it will be on the opposite side of the path from the yellow road sign. The exit is next to the Radio Tower zipline stop; it will give the player a warning triangle.
Obtaining the mutants' treasure will unlock quests on the Wellspring and Subway Town Job Boards to "clean" the corresponding sewers. This will allow the players to engage all the mutants left in the sewers. The reward for returning to the sewers will be the chance to pick up any forgotten items of loot and $100. This sewer could also be the one Rikter Outrigger and Ramos Outrigger occasionally mention due to its closeness to the Outrigger Settlement.