What's more logical is having mobile retention tank emptying carts at stations were units have layovers, they can tank the water supply and empty the tanks quickly / easily.What a bizarre suggestion. There's a lot of difference between scooping up water from a trough fed by the main and dumping solid human waste at high speed over the track. We are at last getting rid of rolling stock that sprays the 'brown mist' everywhere, so any suggestion of creating yet more hazardous waste is ridiculous.
It's yet another major failing of this train, in part caused by knee jerk decisions in procurement.
The days of dumping brown waste on tracks should be a thing of the past, it's terrible how it went on for so long.