A second mega-dairy is planned for Eastern Oregon, close to Threemile Canyon Farms, one of the largest confined animal feeding operations in the nation. The proposed Willow Creek Dairy would house 30,000 animals. It would be the second-largest Oregon dairy, after Threemile Canyon, with 70,000 animals, said Wym Matthews, who oversees confined animal feeding operations (CAFOs) for the state Department of Agriculture. The department is taking public comment on the dairy’s proposed water pollution permit, which lays out how it must manage the 187 million gallons of manure it will produce each year.