Like I said, it's politics, and some people's oxen are going to be gored.
This is not a new thing, this has been going on, in one form or another, for over 40 years. The cousin I mentioned before has since sold his place and moved to Denmark: just too many people and not enough dirt in The Netherlands. We have the same type of problems here in the DelMarva area and chicken houses, for example. CAFO's are what they are, love them or hate them, but they produce large quantities of concentrated manure that has to go somewhere. Historically, many of these regions have simply been spreading it, over applying it at a gross multiple, and attempting to use it, the best they can, by growing Nitrogen intensive crops like corn.
In our state, we have to have land application permits to apply CAFO manure (including from my fish farm) that limits the amount of N and P we can apply to ag land. As with all regulation, a PIA, but a couple of bad actors ruin it for everybody.
The "new" regulation is really an attempt at holistic (multi source) N management of what little environment they have left, and as I mentioned, someone's oxen are being gored. It doesn't just use land application permits, but also the number of animals on pasture. Some, like my cousin I mentioned, saw this coming, sold their milk quotas and headed out of Dodge. Others invested heavily in those milk quotas, and now even though they bought the quotas enabling them to sell the milk, they don't have the N allotment to produce that milk. Their enormous investment in milk quotas is threatening to become worthless. Guys, including another one of my cousins with a dairy, are facing losing their family farm and life's work at the stroke of a pen.
