I would be checking the H. & S. manual for guidelines on safe practice. My husband works in Drainage and they have really good guidelines which includes wearing masks in some instances.
I wouldn't be worried about catching HVC unless you poured a few buckets of sewerage over your head after you cut the outside of your nose and then rubbed it in as hard as you could.
I would be worried about what else you breathed in - there's a lot of man-flu in the drains plus more. Perhaps you could keep a mask handy, along with your other safety gear.
The HCV is spread from blood to blood contact,sharing IV drug works & blood transfusions amongst other modes.You had no risk but I agree it wouldn't have been a pleasant experience.Sounds like the guy from the TV show--Dirty Jobs.
Breathing in fumes from sewage will not give you Hepatitis c. I'm sure from what you have described though it is gross enough to make anyone feel sick and have flu like symptoms.
You posted in the Hep C Forum, and you cant get Hep C from breathing sewage fumes.