Does NYC water have to be filtered and what does filtered water have to do with kosher?

Does New York City water have to be filtered? And  what does filtered water have to do with kosher?   Most municipalities filter their water, because  of the low quality, it requires filtration. New   York City water being of such high quality  doesn't need filtration. Consequently,   there are little creatures that are left in the  water, and they're known as copepods. Copepods   are crustaceans, which are not kosher. Now,  these little creatures could be seen by the   naked eye. Therefore, they have to be filtered  out in order to be able to drink our water. So,   water has to be filtered with a filter  that is at least 50 microns or smaller.   That's going to be enough to be  able to filter out these creatures.