The entrance is located in the Scorcher territory beneath the low highway ramp, where a Vehicle Jump can be hit when boosting off the broken side. Once you pass under the water gate and into Scorcher territory, head right towards the ramp with "Dead End" written on it. To the right of the ramp are three supports. Between the second and third support, across from the Stanley Express Mailbox, is the entrance hatch.
- Upon returning to do final clear out, there sometimes appears to be a mutant below the floor that will throw blades at the protagonist. It is unkillable and the player will have to reload a save from before their first descent into this sewer to correct this.
- Equip the rail gun and you can see the four mutants below. Stand where you first collected their treasure. Two double kills and you should be good to go.