Is it possible to remove the feces from the river?

[WayneEE]

Some people in the pipeline said that the smell of water is a bit strange. Then I found the feces left by the boss in the river, the map of the final boss.

I have tried to burn it with fire, or dye it orange, and found that it can't be dyed. Also tried to connect the electric current to the river.

I just can't remove the big feces from the river.
Have you succeeded?

[DavidM]

The npc comment is just a joke.

[WayneEE]

Hahahahahahaaaaaaaa.........OK