Well, there's a website for the water testing done by the city of Madison. Unfortunately it hasn't been updated since 08/19:

http://www.ci.madison.wi.us/...health/ironman03.htm

When they tested it on the 19th it was pretty darn close to 78, but I'm hoping things have cooled off since then. There has been a lot of cool weather since then (at least in Chicago).

http://www.triathlete.com/forum_msg.asp?msg=16955

Zeke