answers to a couple of questions

In my opinion size would matter more because once you have more livestock than you have land, manure storage and application becomes a bigger problem. But ownership matters too of course, responsible management no matter what the size of the operation.
Our farm is not markedly larger than in the 1970's-80's. We have bought some family land of relatives when they no longer wanted to own it, and we actually rent less now. (In 1906 the original holding was 350 acres plus pasture, and according to area maps that was not unusual. Not many people had 40 acres, most had at least 160 )
The number of cattle have not grown either for quite a few years, the biggest change was the addition of 3 sided sheds a few years ago for protection from the wind
The place has always supported the family plus one and sometimes two hired men. In our 35 years we have only one full time hired man, with another fellow who is retired but will help out as needed.
a number of years ago someone from soil conservation made the rounds of the area and recommended who should or should not have a runoff lagoon, we were told it was not necessary.
We have fields tested periodically to be sure there is no over application.
Dry stacking with the bedding will compost and is better than a lagoon. And we bed generously. Plus of course we only have 6 mos of manure issues and that in the cold months.
We certainly hope that a couple of members of the next generation will want to farm too.

You might want to reconsider that runoff lagoon. Under the new EPA final rule that went into effect December 21, 2008, all livestock operations of any size that discharge pollutants are liable for fines of up to $32,500 per day retroactive to February 27, 2009. You have until February 27th to decide whether to file a Nutrient Management Plan and apply for a National Pollutant Discharge Elimination System permit. Size no longer matters. You can certify your operation as having "no potential to discharge". But under the new rule the EPA says you have a "duty to apply". If you do not get the permit, and in August you get a 5 inch rain across your lots, you are liable for a fine up to $6,000,000.

If we get a rain in august of any amount it won't matter, our cattle are at pasture and our manure is in the field.

Most runoff occurs during snow melt or spring rains, before the crop covers the fields. Some years have more runoff events some years have less. Water runs over feedlots and fields, picking up anything that will dissolve in water and even carrying some solids. Rain falls on open air manure stacks, water runs from there into ditches and from there into creeks and rivers. Maybe a wetland intercepts the water but most wetlands spill over at times and the manure water enters the watershed and the ground water. Wetlands are a direct connection to our ground water so anything washed into those can also enter our ground water. Chemical fertilizer is one of the top pollutants of ground water. It's great to get those wetlands into CRP.

There are times when water washes over your manure and gets into the ditches and creeks. To pretend that water never leaves your farm is to think the world is flat and your farm is bowl shaped. But then it wouldn't be ag land, it would be wetland.

Most days this is not happening, most days it is not raining hard so when you look at your farm most days it looks like there is no runoff. But of course there must be sometimes or your feedlot would be a little lake.

I do not pretend that anything happens in a vacuum.
Which is more than the the mega farm promoters can say. At the meeting this summer only 1 person from the SDDENR admit that lagoons leak.
we are strong believers in CRP and responsible farming.
i am very proud of my neighbors and how they banded together.