No U-bend on sinks, smells from grey water tank.

Spriddler

Compass Navigator m/home.

My sink waste and bathroom basin appear to discharge straight into the holding tank without any form of trap or U-bend.

I've noticed smells coming from the sink and basin which I assume is due to the 'straight through' plumbing. It seems a very bad design to me.

Are other m/homes similarly plumbed?