Article contributed by Yates County Soil & Water Con Dist, Cornell ProDairy, NYCAMH
Hydrogen Sulfide is a well-documented and extremely dangerous gas that can be found in manure storages. Hydrogen Sulfide (H2S) is a by-product of bacterial breakdown of organic compounds inside a manure storage. Much of the gas can remain dissolved in the liquid and remain contained under the crusted top layer in a manure lagoon until agitated. It is heavier than air and can concentrate low to the ground or in confined spaces. In a confined space H2S can also displace oxygen since it is heavier than air. Any extra source of sulfur that gets added in the manure has the potential to increase H2S gas production once it reaches the manure storage. Farms that utilize gypsum based bedding and anti-slip agents have an increased risk of H2S gas production due to the sulfur content in these products. A significant amount of research was performed by the Yates County (NY) Soil & Water Conservation District and Town of Benton Fire Department studying the levels of H2S gas around manure storages. Results showed that farms utilizing gypsum products almost always carried higher levels of deadly H2S gas during manure storage agitation and pump out. Studies also showed deep bedded packs can also carry high levels of H2S gas.
In December of 2021, a dairy farm in the Finger Lakes region of New York was agitating an under-barn manure storage for field applications. The barn has a traditional gutter cleaner that empties into the center of the barn to a manure storage located directly underneath. Under-barn manure storages can be especially troubling for H2S gas as levels concentrate quickly with only small areas for escape. This can “super concentrate” levels very quickly, especially during pump out. Fairly shortly after agitation, four cattle were discovered dead inside the barn with a fifth cow euthanized the following day. This farm was using a gypsum product inside the dairy facility. The cattle were discovered in an area adjacent to the opening to the under-barn storage. H2S gas quickly built-up during agitation and began to disperse into the dairy barn, killing the cattle.
Farmers should always be aware of H2S gas, regardless of gypsum product usage. Under-barn manure storages is the one area where there is a general consensus that gypsum products should not be used due to the extreme dangers involved. Any farm utilizing an under-barn storage should have good ventilation installed towards the top of the storage and at the barn floors where H2S gas would begin to concentrate. As much as is practical, the barn should also be depopulated during agitation and pump out. Fans should be on as high as possible and all family members and employees should be made aware of the risks. H2S gas levels at the fan exhaust area could be extremely high, so caution should be utilized in this area as well.
This is the second incident in a 12-month time span involving H2S gas on a farm using gypsum in the Finger Lakes area. This particular incident could very easily have injured or killed people instead of cattle and should be a reminder to all farms to be concerned and alert about H2S gas.
For additional information on hydrogen sulfide dangers, you can contact Tom Eskildsen at the Yates County Soil & Water Conservation District at 315-536-5188 or tom@ycsoilwater.com. Additional information and publications can be found on the Cornell University Pro-Dairy Website. Additionally, NYCAMH is always available to come to your farm and provide manure hazard safety training. For more information visit our webpage, call NYCAMH at (800) 343-7527, or e-mail: info@nycamh.com.
