The letter says Marks had once said she'd revoke the permit if significant errors were found in the application.
The Alliance, at this link, lists in some detail what it believes to be significant shortcomings. To name but one, the Alliance says an environmental assessment by the Farm Services Administration had "45 significant errors, misstatements, inaccuracies and other problems." Among others, the National Park Service was not notified about the hog feeding operation — which will produce waste from 6,500 pigs — and excluded from the assessment of impact despite the farm's presence in the national river's watershed.
Little Rock lawyer Hank Bates sent the letter in behalf of the Alliance, the Ozark Society, the National Parks Conservation Association and the Arkansas Canoe Club. His letter specifically objects to the nutrient management plan. It says the plan calls for spreading hog waste laden with phosphorous onto fields that already have more phosphorous than they need. Inevitably, rain will put the phosphorous into the streams, which will produce algae and alter the Buffalo River ecosystem.