Geotextile covers to reduce odor and gas emissions from swine manure storage ponds

Odor, hydrogen sulfide (H₂S), ammonia (NH₃), and volatile organic compounds (VOC, GC/MS analytes) were measured between May and October 2000, and between April and October 2001 at sites representing three different swine production facilities (8000-head nursery, 2000-head finishing, and 3000-head finishing) in southwestern Minnesota. For each facility type, two farms were tested. The paired farms had similar manure storage ponds, production phases, herd sizes, genetics, and diet formulations. A manure storage pond from each pair of farms was selected as treatment (with geotextile cover, Biocap™), and the other as control (without cover). Results showed reductions in odor, H₂S, and NH₃ flux rates due to the geotextile cover, but performance in reducing odor and H₂S deteriorated during the second year of the study. No significant differences in VOC (GC/MS analytes) emissions from covered and non-covered manure storage ponds were observed during the two-year study. Analysis of ambient H₂S data suggested the covers were effective in reducing ambient H₂S concentrations near manure storage ponds located at the two finishing units. Odor and gaseous flux rates were poorly correlated with relevant manure parameters (NH₃-N, sulfides, and VOC).