As discussed earlier, about 2.3 x 108 kg of manure is generated each day in the US by the pig industry. Manure is land applied because its value in supplying nutrients to crops as well as of disposing unwanted waste. Pig manure is one of the key fertilizers used in organic farming. Therefore, it is important to ensure that manure from pig farms is free of chemicals that may harm humans, other animals, and/or the environment. When completed, this study will reveal the fate and activity of estrogens in swine manure and the possibility of estrogen losses both through leaching and in surface runoff. All this information will be helpful in assessing the extent of potential problem as well as in developing management strategies that will reduce estrogen losses to ditches, streams, and rivers.