I'm deff no engineer or ship designer but could they include some type of bladder in the fresh water holding tanks kind of like how my carpet cleaner works - fresh water in the bladder, bad water in the same tub just outside of the bladder - that way they'd at least have a way of storing #1 and #2 until such a time as they can treat it before emptying into the ocean - not for use all the time when they have power etc just for emergency storage during situations such as these. (I hope I made sense how I wrote it and I have no idea how it would work large scale, works great for my little 1 gal carpet cleaner holding tank thing)