Casanova isn’t on a public water system, so there’s no utility report to find a hardness figure in. USGS notes that private households in Fauquier County draw on wells, and wells differ from one property to the next. The hardness of yours is a number you would have to measure at your own tap. The flush deals with what that water leaves behind, which settles at the bottom of the tank.
In ZIP 20119, the Census area Casanova sits in, about half of owner homes heat with electricity and close to three in ten with propane, and none use utility gas. A water heater here is most likely one of those two. On an electric tank, sediment banks up around the lower element. On a propane tank the layer lies under the burner chamber, so the flame heats through a blanket of grit before it reaches the water.
The median owner home in the ZIP was built in 1990, more than four in ten owner homes predate 1980, and the village adds frame houses built well over a century ago. A flush on an old tank also tells you something: if the first bucket from the drain valve comes out gritty, the tank is carrying a lot, and the next question is how much life it has left.
Out here the well pump runs on household electricity, so an outage stops the water supply along with an electric tank. On August 13, 2021, gusts of 60 knots put numerous trees down at Casanova Road and Meetze Road. We don’t do well work, so a pump or pressure tank question goes to a well contractor; the tank is ours.