Seepage from earthen animal waste ponds and lagoons - An overview of research results and state regulations

Wastewater seepage from earthen animal waste lagoons and storage ponds can contaminate groundwater with nutrients and pathogens. For almost 30 years, the subject has been the focus of laboratory and field research projects de signed to (I) measure if and how much earthen ponds and lagoons leak, (2) d etermine how different soil types affect seepage rates, and (3) evaluate th e magnitudes and mechanisms of sealing from animal waste. In this article w e present a research review performed to determine how researchers have att empted to answer these questions and how well they have been answered. We d iscuss weaknesses in the body of knowledge and present further research and educational needs. We also performed a review of 14 state regulations to a ssess and compare how different states govern seepage from ponds and lagoon s. Six states regulate the maximum allowable seepage rate from ponds and la goons (values ranging from 0.042 to 0.63 cm/day) while another six states r egulate the maximum hydraulic conductivity of earthen liners (values rangin g from 0.086 to 0.0086 cm/day). The two remaining states regulate neither: The results of this research and regulatory review demonstrate that there i s still much to be learned about seepage from animal waste ponds and lagoon s. We suggest that a risk-based approach to regulating seepage may be appro priate in the future.