A few minutes of Googling is not enough.
A *lifetime* isn't enough :-).
In 2004 they switched from chlorine to chloramine
Sorry; my mistake. I didn't see mention of that little detail anywhere; I now gather that the controversy was due to the fact that chloramine treatment seems to have more side-effects than chlorine.
your point about treatment effectiveness is invalid
Perhaps. While *optimal* chloramine treatment apparently *can* be effective, it isn't obvious that a given treatment with it is. Chloramines are relatively weak disinfectants for virus and protozoa inactivation, per the EPA, for example.
99.9% plus of those cysts would be dead
That isn't obvious to me. First, I still find it incongruous that the cited figures would be for input water. The EPA says in at least one place that it doesn't require measurement of a water system's inflow. And good luck figuring out whether the cited figures are for dead versus viable cysts (it isn't obvious to me how one can even tell one from the other). Regardless, it seems the numbers are pretty useless, regardless, *except* to compare to like numbers (which is what Rockwell did). Maybe the other numbers he cited included dead cysts, also?
a real-world water source which has likely never been tested in history and if it has, likely decades ago
Yet a few lines later you mention a scientist who has done precisely that testing (although I can't find any of his published numbers for Giardia). Rockwell provides citations which seem to contradict your statement. You do a good job of hedging your statement, though; is "likely" 50.1%? is "decades ago" 11 years ago, 16 years ago, or 20 years ago? Does it matter? You could cite Rockwell's paper on that point, but be careful, as we know that paper has at least 4 errors.
Read more here: http://www.modbee.com/2010/05/08/1158938/fouled-waters-sierra-lakes-streams.html#storylink=cpy
I did, including bacterial contamination was easily high enough to sicken hikers with Giardia. I wonder if it could give me the flu, also.
It goes on to say: at high elevations in Yosemite, Sequoia and Kings Canyon national parks, Derlet found a striking difference: Most lakes and streams were clear as champagne and pollution-free.
All in all, the news article you cite (not a technical paper, let alone a peer-reviewed one) is perhaps irrelevant to a discusson of Giaria.
The bottom line: I think to claim Rockwell is in error, one should have to point out the errors in his numbers, or, provide different numbers.
I think I've made this point before: despite your 4 nitpicky complaints with his paper, Dr. Rockwell could certainly have reached the right conclusion anyway. Until I read something that reaches an opposite conclusion and is equally comprehensive and accompanied by as much supporting material, I'm going to continue to drink freely and confidently.