We are going to build an outdoor washdown area, with sink bench, shower also used as dogwash/bootwash. Drainlayer/plumber will do all the restricted work.
It will be within a concrete area, and the washdown will have a floor grate over a set down concrete pit with fall, to a silt trap sump connected with a trap to the drain. The sink could drain straight to the pit, with the drainage trap after the silt trap.
Mainly it will be used for removing mud, hence the silt trap, but at times we would like to be able to divert the washdown water so that if we need to wash or rinse off chemicals that would be harmful to the septic system, we can send it to to an adjacent garden area instead. It would be best to divert before the silt trap, so that doesn't need cleaning out each time the diverter is used, and there shouldn't be mud involved in those sort of rinses.
Is there an easy way to set up such a drain diversion that will not be fiddly to change back and forth?
if the silt trap is in the concrete pit, I can only picture this working with some sort of cover over the silt trap, which would require removing the floor grate to put in place/remove. That would need to be done to empty the silt trap anyway, so we would want to make that fairly easy to lift out, probably by having several panels of grate to make them lighter to lift.
Any suggestions on a good way to do this diversion?