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STAR Grant R833422: Transport and Transformation of Natural and Synthetic Steroid Hormones at Beef Cattle and Dairy Concentrated Animal Feeding Operations (CAFOs) 2007 - 2010
Project Purpose:
This project will assess the occurrence, fate, and transport of synthetic steroid hormones used for beef cattle production and endogenous steroids produced by cattle and cows from concentrated animal feeding operations (CAFOs).
Project Description(s):
Objective:
This project will assess the occurrence, fate, and transport of synthetic steroid hormones used for beef cattle production and endogenous steroids produced by cattle and cows from concentrated animal feeding operations (CAFOs). We hypothesize that the most important pathways for steroid releases from CAFOs are the discharge of contaminated stormwater runoff and migration in groundwater recharged through animal waste lagoons and animal feeding areas.
Approach:
The fate of synthetic hormones will be evaluated at research and commercial beef cattle feedlots located in California, Colorado and Iowa. Synthetic steroid hormones will be evaluated using a sensitive new analytical method that will be developed by modifying existing analytical methods. To quantify the relationship between growth hormone treatment and surface water releases, stormwater runoff samples will be collected at two research feedlots where hormone administration rates and waste handling procedures are rigorously controlled. Additional insight into steroid hormone fate and transport will be obtained by collecting samples at locations throughout two research feedlots and several full-scale commercial beef cattle CAFOs.
The fate of endogenous steroid hormones will be evaluated through the collection of samples at dairy CAFOs located in California. The potential for transport of steroid hormones via surface water pathways will be assessed through the collection of samples of stormwater runoff, animal waste lagoons and other sites that could release steroids during rainstorms. The potential for transport of steroid hormones in groundwater will be evaluated through the collection of groundwater downgradient of leaking animal waste lagoons and a series of tile drains that integrate groundwater recharged over large CAFOs. These results will be complemented by the development of a transport model and soil column studies with synthetic and endogenous steroids.
Project Outcomes:
Research conducted as part of this project will provide a better understanding of the relative importance of surface and groundwater pathways for steroid hormone releases from CAFOs. The results also will help in the development of policy guidelines and agricultural practices designed to minimize steroid hormone releases from CAFOs.
Contact
Susan Laessig at laessig.susan@epa.gov