On Tue, 23 Dec 2008 17:01:16 -0800 (PST), Steve
wrote Re Tempering tank for hot water system:

Interesting....... If there is some possibility of this happening, I
am wondering why it has not been made more of an issue to the
public?????

Because very few people drink water from their hot water heater. If
they do, they usually heat it up more while cooking, making
coffee/tea, etc. thus killing any bacteria that might be present.