One minor suggestion: maybe add a sign or something similar that describes the drain station as such, at least the first one. Now, I’m a meticulous guy when I explore, so it was natural for me to stumble upon the first drain station and figure it out, but someone who doesn’t check any and every detail on the map may not know that they even exist. Especially since their design kinda blends in with the whole “factory/testing facility” background.
So yeah, one little tip for new players would do plenty to save them from some trouble later.