Jotapay,
I think this is a much bigger problem than most people recognize. I did some research a few years back and it seemed that more or less, we have let the genie out of the bottle and there really isn't a simple way to put it back in.
As for good information resources, one name that kept coming up was Christian Daughton, an EPA scientist who has written a number of journal articles and texts on pharmaceuticals in water. His cv is at
http://www.epa.gov/esd/bios/daughton.htm. His work led me to some others who were trying to do remediation on wastewater treatment facilities. If you can find some of these texts that deal with the problems of wastewater treatment, you might learn some useful lessons for protecting yourself.
I've looked at many of the filtering technologies, and they all leave something to be desired in my opinion. The craziest thing the municipalities do is to fluoridate the water. It's impossible to remove except with R.O. or distillation, both of which are wasteful processes. The water sources for many places are actually fairly good, as most municipalities at least try to protect their reservoirs and watersheds, but then they poison it with fluoride at a dose that is not that far below the toxic dose. Ground water can be better, or it can be very heavily contaminated. That's a crap shoot, but it seems like the number of known-polluted aquifers increases every year.
Regardless of the filtration type, it doesn't really help much since these technologies typically cannot filter fast enough for a shower without spending a lot of money on a whole-house-sized system. I came across a study a few years back - I'll see if I can find it again - that determined experimentally that the vast majority of exposure to volatile organic chemicals (VOCs) happened in the shower, and that only a small amount is absorbed via drinking water. So if you can't filter your shower, and your shower accounts for, say, 90% of your total daily exposure, then it doesn't matter if you filter your drinking water or not.
The complete irony in this dirty water business is that this is exactly the function served by wetlands, most of which were drained by the Army Corps of Engineers during the course of the 20th century so the land could be "developed." Now that the natural cleansing function of the wetlands has been removed from so much of the US, we are forced to find methods to replicate this function - and we will have to pay now for what was formerly provided by nature.