Outdoor sink drain

Lantley wrote:

You can water your lawn with water from your garden hose no issue.
But a plumbing fixture cannot drain onto your lawn. With or without a tank.

Many municipalities are now allowing grey water to be used for irrigation/lawns, etc, in the name of water conservation.

enblethen wrote:
Grey water can even be from a dish pan!

In California, in or on any State park or State lands, it is illegal to drain or dispose of any waste water that is stored in or generated in a any type of vehicle. But, a tent or primitive camper can dispose of personal waste water as generated on the ground.

So, is the OP's drain from an outside sink "stored in" (no) or "generated in" (no) the vehicle"? I would argue not. Again, are backpackers breaking the law? Are boondocking tenters breaking the law? No. So what's different?

I have an outdoor sink table that I set up next to my RV. It drains into a small collapsible bucket. I typically use it to rinse my hands when BBQing, nothing more (I don't wash dishes in it). When the small (1/2 gallon) bucket is full, I pick it up, walk outside my campsite, and toss it out onto the ground (no, not near other campsites). I refuse to feel guilty about that, nor do I believe that I am breaking the law or harming the environment in any way, shape, or form.

Here's more, from the USDA Forest Service:
Tent campers without holding tanks should observe environmental precautions for the proper disposal of gray water from washing and cooking. It is recommended that they dispose of the water in toilet buildings (which can accommodate a small volume from individual campers) or take the water to areas beyond the developed campground, and disperse over the ground, away from streams.

Again, I believe that the OP's outdoor sink, since it is NOT plumbed into a holding tank, is no different than a tent camper. JMHO, YMMV