The entrance to the sewers is located west of Wellspring under the highway ramp in the Wasted Territory. When leaving Wellspring, head west (to the left) and you will see the ramp and a rusted highway sign with a light fixture on top. The sewer entrance is directly underneath the beginning of the ramp, right behind the turret.
Upon entering the sewer, you will be placed in a large room. Grab the paint cans on your left, and loot the dead body on the ground. Right in front of you will be two Mutant Clubs. Use the Striker Crossbow to stealthily kill them.
After taking them out, shoot a Bolt at the Scoop Mutant at the end of the room. From here, you can either go right or left. Go right first, and grab the suitcase on the floor. Make your way to the end of the tunnel, where a Feltrite crystal is waiting for you. Note that going this way will result in a two-mutant ambush. From here, make your way back. Loot the corpse on the floor, and make your way into the left door. A lone mutant will run at you, so get a Combat Shotgun ready.
You will eventually reach a small room, where a Club Mutant and two Dagger Throwers will come at you. Use your shotgun to take them out. Once inside, grab the paint can on the right. Then, run to the other side of the room, and grab the other paint can. You will once again have to choose between going right or left.
First, go left. Grab the Canned food and Beer Bottles on the ground, and progress. Two Club Mutants will run at you, so be ready. Next, grab the small items on the floor, and loot the corpse. Heading right from here will take you back to the Wasteland. In order to complete the "Southern Sewers" quest, you will need to find the mutant's loot. To do this, head back to where you came from.
This time, go right. A single Club Mutant will be waiting. At the end of the hallway, you will reach a large room. In here, several mutant variants will run at you. For experienced players, they shouldn't pose much of a challenge. Loot the corpse at the entrance, and then head into the small room, where some spray paint cans are laying. Grab them, and head over to loot at the other end of the room. Loot it, and then head back to the exit.
- Near the beginning of the interior, the interior of Wellspring Sewers is visible as a walkway leading to a pair of doors on a slightly lower level, inaccessible due to a railing.