I would recommend that people with wells have reverse osmosis filtration for their drinking water.
For the rest of the water, a softener/Filtration system where the water is filterd down to 20-30 Microns. Then put a couple of cartridge filters on the main line right after filtering the water down to 5 microns. We have 10 and 5 micron cartridges. The cartridges are inexpensive, and only need to be replaced about every six months.
This will take care of any of the bacterial problems plus a lot more.