Personnel: D. Raj Raman, Assistant Professor, Agricultural & Biosystems Engineering; Michael D. Mullen , Associate Professor, Plant and Soil Sciences ; Alice C. Layton, Research Assistant Professor, Center for Environmental Biotechnology; Robert T. Burns, Associate Professor, Agricultural & Biosystems Engineering; Gary S. Sayler, Professor Microbiology, Director, Center for Environmental Biotechnology; Lara B. Moody, Research Associate, Agricultural & Biosystems Engineering; A. Renea Dyer, M.S. candidate, Biosystems Engineering Technology Program.

Previous work examining livestock estrogen discharges has focused on poultry waste; little has been reported regarding the potentially large environmental loadings of estrogen from dairy operations. To address the gap in knowledge, this work has four objectives.

First, quantify the conservation of estrogens in full-scale dairy waste storage systems. Specifically, compare lagoons and dry-stacks for their ability to conserve applied estrogen loads.

Second, measure estrogen concentration in runoff from plots fertilized with liquid dairy waste. Specifically, document the potential environmental significance of these losses and determine how waste phase affects off-site movement of estrogens.

Third, determine the efficacy of high-rate anaerobic digestion for degrading estrogens. Specifically, establish the potential of this technology to reduce environmental estrogen loads, and elucidate bioreactor operating conditions that maximize estrogen degradation.

Fourth, determine the fate of 17b-estradiol in dry stacks, lagoons, high-rate anaerobic digesters, and soil. Specifically, use radiolabeled estrogens in lab studies to establish the extent to which microbes in these systems can mineralize estrogens.