Could be much worse than pesticide drift, it could be herbicide drift. Food can be washed of course but the effect on your normal beneficials and pollinators could well be affected.

You don't mention how close to the spraying area this would be? Also is the spraying area up wind or down-wind from where the garden would be? Is it possible to construct/erect/grow a windbreak of any kind? Will water run-off be an issue?

1/2 mile is a common recommended distance but obviously on windy days sprays can be carried much further than that.

And I would think the application methods they use would make a difference, how much aerosolization there is. In other words, a small sprayer focused on the individual trees isn't going to drift nearly as much as the generally misting applied by some large commercial mechanized sprayers.

Last, the exact nature of the "chemical" used would have to be taken into consideration since some are clearly more harmful than others.

Dave

The most intensive part of the apple spray schedule takes place from late spring through early summer. After thinning there would be less pesticide pressure. With that much space you could look at late sprawling crops like pumpkins, winter squash or late potatoes.

You would need to check on compatibility of your crops with with fungicides and insecticides used in late summer on the apples, though. Just in case.

If I was in your position, I would set aside a day for internet research. I would get names of large commercial farms in general, large commercial farms in the area, and names of the pesticides you want to avoid.

I would then search for lawsuits past and present describing damage done by those pesticides connected with the problem of drift.

You will find descriptions of damage done and testimony of experts on both sides, all of which will allow you to make a more informed choice in your own plans.

The 'general' results will of course have more information, but the particular area results may have exactly the information that would be crucial to your choice.

If you're in fear or doubt, grow stuff that fruits rather than leafy stuff which is harder to intensely wash.

You can easily wash things that fruit and/or you're not planning on eating the outer parts (peppers, toms, eggplant, squash, melons, etc).

Nice land use gift you got there.