State agencies issued protocols for dumping milk, which can pollute groundwater and decimate fish populations. Though Volenec has not had to dump any of his milk, he’s been worrying about the environmental costs of large-scale dairy farming, from water contamination to climate change. Manure runoff from industrial dairy farming has contributed to a dramatic increase in bacteria and nitrates in the state’s groundwater, according to a study funded in part by Wisconsin’s Department of Natural Resources. (A farm with twenty-five hundred cows produces as much waste as a city of four hundred thousand people.) The E.P.A. recently sampled the groundwater in a thirty-mile area of Juneau County that’s dense with dairy cows and found that sixty-five per cent of the sites had elevated levels of nitrates, which have been linked to birth defects, colon cancer, and “blue-baby syndrome,” a condition that reduces oxygen in an infant’s blood and can be fatal.