Liquid manure, when stored long-term, has no oxygen (anaerobic conditions) resulting in the development and release of a number of manure-borne gases including various odorous compounds and methane (a greenhouse gas). With favorable economics, many farms with long-term manure storages could reduce odor and greenhouse gas emissions by installing a storage cover. Cover products are available for earthen, concrete and steel storages. When properly designed and managed, covered storages can greatly reduce farmstead gaseous emissions. However, when manure is recycled to cropland, odor emissions will occur, through injection or immediate incorporation can reduce field odor emissions. There are two basic types of storage structure covers: permeable and impermeable. Each type has several options with varying degrees of complexity and costs.