Kewaunee County groundwater quality has gotten a lot of attention in the last couple years but experts say that dairy cattle are actually quite clean next to livestock raised in other Midwest states. Kevin Erb, Director of the Conservation Professional Training Program with UW-Extension, notes pigs are much worse.

By comparison, swine operations tend to feed their animals processed foods that are bought from elsewhere. Very little of the land is needed for manure applications and it tends to pile up where it ends up leeching into groundwater.