This is different, though. This is waste water.. human excrement, blood, piss, saliva, sweat.. everything. There's a big difference between getting sick and getting a terminal or lifelong virus. If they don't filtrate HIV and Hepatitis out of the water, such when an "accident" occurs, and you drink it, guess what? You now have HIV and Hepatitis.
you can generally only contract HIV from blood contact, so your average person drinking trace amounts of it (even if there were live viruses in the water) wouldn't get sick.
regardless, water sourced from rivers, lakes and oceans has animal waste and other potentially toxic or virulent material in it - aside from the level of waste that needs to be effectively removed, I don't really see the difference.
***also if you think this is anything like Soylent Green, you should probably go watch it again.