Integrated environmental characterization and assessment of an exposed historic manure repository.

Historic manure stockpiled (active from 1935 through 2018) in a repository mound approximately 15 m high with a 31,415.93 m footprint was sampled from various depths at six locations in an environmental assessment framework. The manure samples were analyzed for nutrient content to investigate potential application as a soil amendment to local fields in combination with biowaste disposal regulations. Results indicate that manure can be used as a soil amendment; however, different crops and land conditions require specific nutrients, and application must be determined accordingly. Likewise, the manure analysis did not indicate any negative issues that would disallow land application as a disposal option. In addition to limiting environmental soil boring into the manure repository, two-dimensional geophysical electrical resistivity imaging was performed to characterize and quantify the deposited manure. Based on those efforts, the material volume within the site's manure repository was calculated to be 611,942.354 cubic meters (m). Finally, based on the geophysical results and the historical information about the manure's deposited volume in the study area, an estimation of the released landfill gases and its expected produced energy is presented.