Steve makes another good point: that the definition of sewage is very specific, and always includes some sort of collection and conveyance. 261.11 does not say human waste, or solid waste, as the Whitney Zone WAG Bag material does. So tested by plain common or dictionary standards, which is the first principle in all legal interpretation, 261.11 does not even apply to human waste deposited in a hole in the back country, so the practice cannot be a violation. USFS may be quite aware of that, and it is the best explanation of why it approved Wasson's notice of intent and does not even mention packing out waste from Wilderness.
It's good that you brought this up. The term "waste" is not defined in the regulations, and I would agree with you that "commonsense" definitions are typically the starting point in legal interpretation. Here is the dictionary definition of "waste":
b : refuse from places of human or animal habitation: as (1) : garbage, rubbish (2) : excrement —often used in plural (3) : sewage
The 9th circuit decision affirming the district court judgment that Wasson violated §261.11(d) by failing to properly dispose of waste is consistent with the dictionary definition:
In the present case, Wasson stored waste (human feces) in a bucket.
Waste means feces, and feces is feces whether it's in a bucket or a cat hole.
