Seepage From Anaerobic Lagoons Degrads Water Quality

2296 Words Jun 16th, 2018 10 Pages
In the 1990’s North America, Europe and Asia have seen a great expansion in the hog industry. In North Carolina alone, the industry quadrupled in this decade. Other regions of the United States, particularly the Midwest, have seen similar growth. As the industry has grown, large scale production, or hog confinement operations, has dominated the industry. The primary method of waste handling for confinement operations is anaerobic lagoons (Midwest Plan Service, 1987). In this method, animal waste is washed from the confinements or housing units to a lagoon and diluted with fresh water. Lagoons allow for solids, from the manure, to settle to the bottom of the lagoon and the ammonium to volatilize. The animal waste to dilution water ratio …show more content…
Although the researchers found increased concentrations in NO3-N, NH3-N, Cl and organic nitrogen initially, data suggested that seepage rates decreased over time. These researchers also stated that “biological sealing of unlined animal manure lagoons in coarse-textured soils will take place over a period of time”. However a recommendation was made stating that unlined lagoons in areas of high water tables and coarse textured soils should not be installed. This hypothesis is also corroborated by Phillips et al. (1983), but in a much more primitive study. These researchers also found that loamy soils were sealed much more effectively and consistently than coarser material. A study confirming this hypothesis by Culley et al. (1989) observed waste from a beef production unit being deposited in an unlined lagoon. The surrounding soil characteristics are coarse sand environments, with the lagoon being constructed below the normal water table, although prior to waste deposition the bottom of the lagoon was unsaturated. The researchers observed that two weeks after initiation of waste addition to the lagoon, the hydraulic conductivity of the bottom layer decreased to 10-8 m/s, or as the authors suggest effectively sealed. The evidence was also backed up by chloride concentrations, a conservative element, seeing significant decreases in the surrounding soil after two weeks as well. The final results indicated that the
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