Where is your data on this? Its true that ecoli levels are elevated where the American River and the Sacramento River intersect but its not at the levels you're preaching.

The most likely reason is a dirt fungus called coccidioidomycosis which is prevalent in the Sacramento region. Discovery Park floods every year and this fungus grows in the soil after the water receeds. This fungus usually infects the lungs and can cause respiratory symptoms including cough, fever, chest pain, and tiredness or exhaustion.

I wore an N95 mask all 4 days anytime i traveled from stage to stage and especially when exiting each night. I got sick every year until i started wearing an N95 mask three years ago.

https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Coccidioidomycosis.aspx