Crud is coming out around the seems of the hot water tank's vent. Some of it is black and gooey which I assume is creosote from from the chimney's previous use. There is also white chalky stuff which appears to be some type of mineral. I put paper toweling on the floor under the vent pipe to catch this stuff and I now see there is a blue ring that formed on the toweling. None of these three things have an odor What are these things coming from and what are they?