Viruses don't get any more infectious than hepatitis. The minimum dose is one virus particle. It also is not easy to kill with chlorine.
In this case, I can understand the public health department's desire for subsurface disposal.
I worked for awhile in an area where hepatitis was common (public defecation everywhere, with the resulting rampant fecal-oral diseases, dysentery, typhoid, etc.). One pretty fit young guy felt sick Friday, was ill Saturday, and dead Sunday from hepatitis.
We have septic, and much as I would like to recycle the water directly, I have made peace with running it through the septic field to be recycled (eventually). The upside of a more direct recycle is not worth it to me, but I can understand others arriving at different uses.
All the best,
Peter