You could route the RO waste water to your fresh water holding tank, fit the fresh tank drain hose with a garden hose fitting w/ shut-off valve, and attach a garden hose to it to drain it to a suitable location, or just store it there until it gets full and drain at your convenience.
Me, if I were to do the RO thing, I would install a water softener in front of it, operate the both of them on the city water pressure, eliminate the silly filtered water spigot and small RO storage tank entirely by routing the filtered water to fill the RV's fresh water storage tank, and run the entire RV with its electric water pump. That way, every faucet in the RV will be filtered and usable, plus, the hot water tank won't get all calcified up with hard water deposits.
Of course, the RV park might get [s]a little[/s]
very upset at me pouring 300 gallons of water down their sewer hookup so that I could fill my holding tank with filtered water!
That being said, I most likely will continue to just use a dual filter cartridge set-up and live with the crummy water like always.
It's just that I like to whack the hornets nest with a stick every once in a while!
