Forty-five large investors collectively managing $1.2 trillion in assets are pressing some of the nation’s largest meat producers to set policies for reducing water pollution in their feeding, slaughtering and processing operations. The investors, who are members of sustainability non-profit advocate Ceres and the Interfaith Center on Corporate Responsibility (ICCR), sent letters to Cargill Inc [CARG.UL], JBS, Perdue Farms and Smithfield Foods [SFII.UL]. In those letters, they asked the companies to assess the pollution impacts…