Is it possible/allowed to have a greywater system installed by a plumber that is simply a tap that you can connect a hose to that takes the water from the water pipe going out (but not including the toilet). So there is a no tank involved it simply runs onto the garden when the tap is on (which you could turn off in winter). Is something like that possible in a suburban area? What is the simplest greywater system with no storage involved? What would the simplest system cost for a plumber to install?