Quote Originally Posted by medvampire
Ben
If I may put my 2 cents in here.
I also posted in the other forum you mentioned. Most pathogens can live in non chlorinated water. The levels of suggested chlorine allow for rapid kill times. This becomes important if an infected person enters your pool to prevent the spread of the infection. It is even more important of you have a person with a lower immunity. Children under the age of 3 to 5 are at higher risk due to an undeveloped immune system. Some thing that will give an adult a good case of gut cramps could in essence kill a child. With the emergence of antibiotic resistant pathogens we are now seeing in the lab total kill of these pathogens is not optional.
Steve
That's a point I hadn't considered, but should. People forget that pools are -- to some degree -- not just a swimming hole, but a community toilet. Adequate chlorine and proper filtration can make them safe-to-swim-in community toilets, but can't eliminate the sources of risk.

It's worth noting that all the serious E. coli infections that resulted from waterpark use a few years back, all apparently occurred in water features that were maintaining minimum levels of chlorine.

Ben