@therjes Welcome to Connect. You have come to a good place for sharing valuable information with like-minded people. I wish this forum had been available 12 years ago when my family first began dealing with gluten issues on top of the many food allergies we have had for a lifetime. It has become much easier to find good information about gluten-free foods, but confusion still exists.
@eileena Do you have any research-based information to share showing crops were tested and found to be contaminated in the field with gluten by runoff water? I would be interested to see that, because every time I have seen the claim, it was based on the theory that if plants could be contaminated with pathogens or pesticides from runoff, they could also be contaminated with gluten.
The primary causes of oat contamination are using shared farm equipment or transporting in trucks which carried wheat, that were not adequately cleaned and/or processing in a facility that also processes wheat or barley and is not completely cleaned or storage in bins that are contaminated.
Cross-contamination of frozen vegetables may occur if they are processed in a facility that coats some of their items with flour to prevent sticking together. Wheat coating was a problem in my family's early food allergy days (and we have many among us - some life-threatening) and most manufacturers have stopped using wheat flour or cornstarch for this purpose because of action by food allergy networks and activists. For example, commercial shredded cheese used to be coated with flour as an anti-caking agent, making even nachos unsafe for gluten-free people. The big producers stopped doing this years ago.
In my experience, contamination with gluten and other allergens (a big one for my family is tree nuts) is most likely to occur unintentionally by transfer on food-prep surfaces and utensils. Or by manufacturers who change their recipes and add a dangerous-to-me ingredient without making note of the change on the front of the package. Or by restaurant cooks and servers who think food allergies are "not a real thing." Or by well-meaning friends and relatives who just don't understand a little bit is not OK.
I look forward to hearing more from you about your journey with gluten-sensitivity.
Sue