Disposal Question

Hi,

I"m not sure how the whole plumbing process works under the sink, but if I have my dishwasher on and poured dirty water down the sink on disposal side, so my question is, will that water get into my dishwasher water because the unit is on??

Thanks

No if it is plumbed right there should be no problem.

That's correct, it should not get to the DW. But, for maximum protection (and code required in some places for homes, and normally required for commercial DW) you'd have an airgap device between the DW and the drain. This is exactly what it sounds like - it has a built-in air gap so the waste FROM the DW can drain out, but if waste from the drain tried to get back to the DW, it would come out the gap in the device (usually on the counter next to the sink). Many are installed with a high loop of the drain hose, and for most situations, will stop back draining into the DW. If that high loop is omitted, or there's some high pressure pushing the drain water up (not very common), and there's no air gap, then yes, it can happen.