I'll confess: I mostly dump it out in the backyard. I store water mostly in 15 and 30 gallon barrels, and when it comes time to rotate out water, I empty the old, clean with a bit of bleach, rinse, then refill, mark it for another 12-18 months, and go on with my day. My conscience is mostly clean - we are locally blessed with mostly an abundance of clean drinking water in the Pacific Northwest.