How come the water is not infected?

[Dyehardjr]

When Tommy was refusing to get cleaned off I thought the Zombie's may have a weakness to water. But that theory was quickly shot down was they started swimming towards Michael and Pegs on the boat. As to why it's not infected, maybe there is something to my water theory in the sense that the virus cannot be transfered through it.

Checking on the wonderful world wide web, I came across a website called http://www.waterencyclopedia.com/Mi-...the-Ocean.html. Here, I found this quote:
"Viruses are entities that require bacteria or other cells in order to make copies of their genetic material and to construct new casings that house the genetic material. Scientific studies have shown that 10 to 100 million viruses can be present in a teaspoonful of sea water." This may fight towards the fact that many viruses can in fact survive in oceananic waters.

But there are viruses and bacteria that also die in salt water... ever gargle salt water? Sure, it's disgusting, but it helps with the common cold. So until The Tower does a few more experiments, like sticking a zombie in a tank of salt water, and then having someone drink that water, we won't really know what will happen...