"So any area that might have wildfowl on it needs to be designated lead free."

I don't think that is what they are saying , I feel they are asking that any area that is managed for waterfowl needs to be non-toxic shot only.

"I don't believe the upland hunting lead shot that winds up in the wildfowl waters is a signifigant killer of wildfowl."

I am not trying to be a smart a++ here , but this is not a case of what any of us THINK . It's a case of what the numerious lead poisoning studies have shown .
Lead shot is lead shot , it doesn't matter if it came from a waterfowl load or a upland load .