This is so simple, but so useful! You have the sink at the top with the pump attached, then you’ve got the water reservoir and the gray water collection below. Press the pump peddle and hey presto! Running water… Best of all, when not in use, the buckets fit inside each other and the pump/tube/peddle fit inside the top bucket.
This self contained sink could also be used in an off-the-grid home, that doesn’t have running water. You could build a nice sink surround and pop in a nice metal bucket at the top (or even a normal sink), and hide the other buckets under the sink with a curtain etc. So there you go, a great little self contained sink system for camping, or use off-the-grid.