Manure Storage Cover and Flare Systems: A Win-Win

The increase in greenhouse gas emissions within the last five years has caused concern within the New York State Department of Agriculture and Markets. A state-funded report released in 2020 listed opportunities for mitigation and adaptation to assist in the effort to protect the quality of our air and the resiliency of our farmsteads. One recommended concept was the use of a cover and flare system for manure storages.

Cover and flare systems are used to trap and burn off the greenhouse gases of carbon dioxide, methane, and nitrous oxide that are produced by manure. These greenhouse gases are more potent, 84x and 264x respectively, than carbon dioxide. Therefore, Agriculture and Markets is targeting manure storages as a mitigation practice. One of the challenges of cover and flare systems is the need to separate the solids out of the manure. A separator system, which can be quite costly, is needed to do this. However, the separated solids can be used as bedding for the cows or as compost. Once the solids are separated, the liquid goes to a covered storage where gases are collected and flared off.

When it comes to covers, there are two types used: permeable and impermeable covers. Permeable covers are more budget-friendly but less effective at trapping the odors and emissions and do not have a long lifespan. Impermeable covers are good for odor and emission control but do cost more upfront than permeable ones. They are usually made from geosynthetic or HDPE materials. These materials give the cover a lifespan of 10-20 years, depending on environmental conditions.

If this is something of interest to you, be sure to consult an engineer before starting your project. It is also important to have a water management plan, as the cover will collect rainwater. There are multiple options for water management. One option, which requires DEC approval, is to pump the water to a nearby body of water. Another option is to use it for irrigation.

There are many benefits associated with covering your storage and flaring off the greenhouse gases produced. The most noticeable is the difference in odor around the farm. Once the storage is covered, all the gases are trapped by the cover, resulting in improved smell around the farm and happier neighbors. Another significant benefit from the use of cover and flare systems is the increase in storage volume and duration. Covering the storage prevents rainwater from entering the storage. For example, a 3-acre area with 30 inches of rainfall over the year creates 1.6 million gallons of water. That is equivalent to over 250 loads of water alone being hauled out of the storage. As mentioned above, separating the solids is also a benefit. Not having to put solids into the storage also lengthens storage duration and increases storage capacity. The separated solids can be reused as bedding for the cows, providing the same comfort and milk production as other bedding materials, and potentially lower somatic cell counts, while lowering your bedding bill. All these benefits can be realized while helping reduce methane emissions.

A 2018 case study was completed on a facility in Western New York where a 115,000 ft2, 60 mil HDPE cover was installed on the lagoon. Among the advantages from the installed solid separator and cover and flare system were higher milk production, improvements in odor control, improved cow comfort, a decrease in somatic cell counts and greenhouse gas emissions, and cost savings from not hauling the annual precipitation addition from the storage. The biggest benefit noticed was the ability to switch to the recovered manure solids for bedding, allowing cost savings on other materials and improving the quality of the bedding. The overall cost of the project was hefty, however, portions of the project were funded.

There are funding opportunities available for cover and flare systems. New York Soil and Water Conservation Districts (SWCD) and Agricultural and Markets created the NY Climate Resilient Farming Program (CRFP). CRFP is a competitive grant program that funds projects aimed at mitigating the impacts of agriculture on climate change, such as greenhouse gas emission reductions. Make sure to talk to your local conservation district and your planner about potential funding opportunities.

In summary, cover and flare systems are a great way for farms to mitigate their greenhouse emissions. While the project’s initial cost, between the separator facility and cover and flare is hefty, the potential benefits outweigh the costs in the long run. The system helps reduce odors and greenhouse gases in the atmosphere while potentially saving and making money for your farm in the process; a win-win. Remember, there are funding opportunities available for projects like this and others, so be sure to talk to your farmstead planner, SWCD, and NRCS if this is something that interests you. If you would like to read more about the case study, please reach out to your farmstead planner.