A funny thing happened on the way to the reservoir... Not.
In fact, a lot of unfunny things have been happening on the way to absolutely everywhere, not just to the water supply. But we might as well start there, especially as someone else led the way -- someone whose cup runneth over, so to say.
The musical question here, for which there are no chairs available on which to sit or catch one's breath, once the music stops, is this: How much does 38 million gallons of water cost? Another question tends to come up right away: Why would anyone want to know? Other questions follow, flowing right along from these initial queries.
If we're talking about money, the cost of the water might also depend on where you price it -- if there's a drought going on, say, or if there's a raging fire nearby that needs a good dousing, and so on. These are all good questions, all very excellent angles worthy of consideration. As is so often the case in life, some questions simply have no satisfactory answers. This is one of those times.
The reason for the question in the first place, the cost of 38 million gallons of water, is because that is how much drinking water a city is dumping, of deferential respect for subscribers, owing to contaminants in the water.