Ever moved a large pile of sand that's been stored outside? Once you get a foot or so into it, there's going to be some moisture. It's not going to be much by w

Ever moved a large pile of sand that's been stored outside? Once you get a foot or so into it, there's going to be some moisture. It's not going to be much by weight, but it's there. Of course, it's going to vary depending upon environmental factors (humidity, temperature how recently it rained, etc). That contributes partially to the liquefaction.