>What do we need to do to educate ourselves more about what are acceptable farm odors?
Acceptable farm odors can be easily defined by farmers and the folks who live near them. There are the rare birds who move to a rural area then complain about the odors and the dust from the gravel road, but you never hear about farmers complaining about the odors coming from neighboring farms -- except when they are CAFOs (as CAFOs have been generally defined on this site).
In my experience, it has been the long-term farmers who are most offended. The difference has to be in the bouquet, the concentration and the duration of the stench.
Give a small grant to a non-agricultural school (Civil/Enviro/Chem Depts) to quantify the odors around conventional farms and again around CAFOs. They MUST leave sampling equipment with the residents so samples can be taken when the "event" is in-progress. I have no doubt that within a year they could demonstrate quantified differences between CAFO and conventional operations.
Once you have the physical definition, then use it to shut down the CAFOs.
Does that mean that I think CAFOs cannot be operated without damaging the environment and the people living around them? The short answer is YES. The longer answer is an unequivocal, resounding YES.
Do I think they can be re-engineered to work satisfactorily? Given that they will be operated by people, NO, not unless the size is dramatically scaled back -- to that of a traditional farm.