I think it would be a tough sell to a judge that every backpacker is required by 36 CFR §261.11 to carry their human waste out of every National Forest, even their waste water (pee?).
I could definitely see that being a sticking point for a judge. But...it's basically how the federal district judge in Oregon and the appellate panel of 9th Circuit judges interpreted §261.11(d) in US v. Wasson.
The prohibitions in §§261.3 through 261.23 are "general prohibitions" that apply throughout the national forest system: "The prohibitions in this part apply, except as otherwise provided, when: (1) An act or omission occurs in the National Forest System or on a National Forest System road or trail." 36 CFR §261.1. There's nothing in §261.11(d) (or in any of the docs in US v. Wasson) suggesting it would be limited to RV holding tanks, developed toilets, etc.
The challenge was to i.d. a regulation requiring the packing out of human waste generally from the Whitney Zone, and §261.11(d) was applied in exactly the same way to an individual in another national forest. Analytically the elements of the prohibition are simple: was human waste removed from the site or area? If not, was the waste deposited in a receptacle provided for that purpose? If the answer to both questions is no, §261.11(c) can -- and actually did -- support a citation/prosecution.
There is no reason analytically why someone doing the same thing in another national forest (failing to remove human waste or deposit waste into a provided receptacle) could not be similarly prosecuted. If someone in the Whitney Zone were cited under §261.11(d) for failing to remove waste, an argument that wag bags are not lawfully provided waste receptacles would not be a defense. The wag bag history might be interesting but when all is said and done you have still violated §261.11(d) by failing to remove waste. At least that's what US v. Wasson strongly suggests could happen if someone were to be cited.
Lots of interesting issues might come up during a case like that. Such as, was it legal to remove (burn down) the toilets and implement a pack out system without completing the ongoing NEPA process that was in the process of evaluating those very alternatives? Seems like a judge might direct Inyo to go back and finish that NEPA process if they want to enforce wag bag use for this specific area. And then that would bring up the obvious impacts that we see on the trail.
I don't know about the legality of burning down existing toilets. But I think it can be argued that in order to require the carrying out of human waste in general, a national park would not need to take any affirmative action at all, as that default policy is already built into the existing federal regulations. I'm not going to claim any familiarity with NEPA but my hypothesis would be that NEPA compliance would not be required if the forest service simply followed the default policy of removing waste, as there would be no proposed action or project to be evaluated.
But assuming NEPA must be followed in order to implement a wag bag policy, why wouldn't NEPA also be required for a policy authorizing disposal of waste in cat holes? Lots of examples of national forests informally authorizing waste disposal in cat holes (arguably exercising their authority under §261.11(d) to "provide" receptacles for that purpose) but is there a reason why a cat hole policy would get a free pass from NEPA but not wag bags? Would there not be environmental impacts that should or must be evaluated?
Just throwing out these questions for discussion's sake; again, I'm not familiar with NEPA. Also, not saying the interpretation of §261.11(d) being made here would necessarily be followed by every judge everywhere, only that there is a verifiable example of §261.11(d) being used to cite/prosecute an individual for failing to carry out waste from a national forest, and a 9th Circuit panel didn't have a problem with it.
