dunno as i'm still stuck with septic system and hate it. i'm not in the kind of setup that i need perfectly white clothes that often nor do i worry if some stain isn't completely removed. i don't dribble on my clothes much anyways... more often it's just dirt that needs to come out and BO which washes out with a little soap. sunshine and fresh air take care of sterilizing and freshening enough for me.
they detect human strains of e.coli, nutrients too but some are digested in the tank, but once through the tank to the groundwater leachfield most have little more happen to them. this is why agricultural pollutants in wells are being detected (blue baby syndrome), if the ground was capable of actually digesting this stuff it would be done... so it isn't and the price will be paid by future generations in one way or another... if you want something digested it has to be brought in contact with the right bacteria/fungi/organisms which most do not live down deep enough and are not active enough to take care of it all. wetlands will do a lot of cleanup and are a good alternative to agricultural and also grey water, but best of all is to make sure toxins aren't getting there to begin with.
it takes a chamber to collect it and then someone to move it after the chamber gets full. in a single house you can design the chambers to the right size so that they don't get emptied until the compost process is complete (instead you just change which chamber things go to when one gets full). that ways you only have to move composted waste. worms and soil will take care of it. leave it in a covered pile for a year or two and there's no remaining issues with bacteria or smell. needs to be covered though to keep rain from leaching stuff away. prime garden/soil material when done. if you're worried about bacteria after a year or two you can bury it below the plants and use topsoil to cover it and then nothing gets splashed on plant leaves or produce.
for apartments the easiest system is gravity fed chute to a chamber and then the chamber gets emptied when it gets full and the waste is then composted in some other location. they have trucks, sucker hoses, etc. for doing things like this. just has to be be done and going and then the biogas can be collected too for burning as it's better to be done than letting it escape unburned.
unfortunately, it really doesn't work that well for certain drugs, and mixing industrial pollution and other waste water with human waste and clean water being used as transport system is really poor design. we have done it in the past because water was cheap and rivers acted like wastewater treatment plants, but now they're finding out that it doesn't work and the rivers smell like sewage all the time and the animals are being affected by the drugs, metals, cleaners, etc... so no, it's not really a good system and it's going to only get worse with the water being reduced (already they are having problems in CA because the systems were designed to have so much water in them and with the drought people aren't using enough water... oops...).
water can be cleaned up, but you ignore the other side of the equation, the rejected part of the water is even more concentrated and unsuitable in many cases for uses in gardens or agriculture.
they've been doing various projects around the world in this vein for years. the resulting water is often pumped into the the ground at some location or sent through a wetland to make it acceptable at the other end for it to be withdrawn and then used again (after being treated yet again). it's a trick used to get people to accept it, but it is horribly inefficient and expensive when compared to an alternative system. the problem is that it is the embedded system so it is hard to get people to change or to see why the change is needed.
now if you can see the difference in how much those pipes, pumps, water treatment plants, maintenance, etc. all cost in comparison to what a dry composting system would cost and what the maintenance would be. there's just not enough money in it for the politicians to get excited about it. not as much room for rewarding cronies, not consumptive enough, doesn't generate enough taxes, etc. and of course, people freak out about even thinking of human waste, so much gets hidden in the waste stream along with it. a convenient slight of hand for many...
songbird