Manure structures should be monitored during extreme wet weather conditions
Recent heavy rains have added to what may have been nearly full manure storage structures. Livestock farmers are encouraged to monitor these facilities and prepare to take action should an emergency develop.
April 19, 2013 - Author: Gerald May, Michigan State University Extension
No one expects emergencies. While we plan for difficult times, sometimes a sequence of events results in situations outside the parameters of normal planning. A late spring, combined with heavy rains across Michigan, have many livestock waste storage structures approaching overflow volumes. Michigan State University Extension recommends giving these structures immediate attention by monitoring them to prevent a major environmental event.
What do you do if the manure storage is approaching overflow volume?
Transfer to another storage area. Perhaps the ideal solution is to move the manure to another storage structure that has a greater freeboard. Be sure the manure storage facility you’ll be transferring into is structurally sound and can safely hold the manure being transferred without exceeding its own freeboard requirement.
Apply a limited amount of manure to select fields. In many instances, lowering the manure just a few inches will be helpful; possibly buying enough time for the weather and field conditions to improve. Consider hauling a few loads now on fields with lighter well-drained soils that may support manure application equipment. Hay fields or fields with crop residue may also support tractors and manure spreaders. The emerging hay or crop residue will also help capture the manure nutrients and reduce the risk of nutrient runoff. Rule out all fields susceptible to runoff in persisting wet conditions.
In a dire emergency, where manure is near the top of the berm, starting to overflow and there are no other options, consider pumping off a small amount into a low area in an adjacent field. It is more desirable to control where the manure is going then to have the storage bank give way and lose millions of gallons into a ditch, creek or wetland. If utilizing this last course of action, transfer low nutrient waste by either pumping off the top of the manure storage structure where the rain and dilute manure has been captured or pump from a storage structure that collects low nutrient waste then transfer the more nutrient rich manure from the manure storage structure approaching full. This course of action may be in violation of the Michigan Right to Farm Generally Accepted Agriculture Management Practices (GAAMPs) and on permitted farms the Michigan Department of Environmental Quality (MDEQ) National Pollution Discharge Elimination System (NPDES) Permit. Be sure to document the situation and the emergency need to transfer manure, document the amount of manure transferred and that the freeboard was reestablished. Under this scenario, evaluate the risk and choose the action that will result in the lowest environmental risk.
Review your emergency plan now. Know who to call and what needs to be done in an emergency situation. Make sure the contact information for the large equipment operators needed to contain emergencies is up to date. Review emergency management procedures with all appropriate employees. Insure they all know the procedures to follow in case today’s annoyance turns into a full scale emergency in the future.
Monitor manure storage structures. Just like the soils in fields, the banks of earthen manure structures are saturated and weakened. Walk the perimeter of these storages on a daily basis. Look for any weakness in the banks themselves or any small ruts where manure may start to seep out. Once manure starts to seep through it will quickly erode the bank resulting in a larger manure spill.
Permitted farms should stay in contact with MDEQ. Permitted farms are encouraged to contact MDEQ prior to making any changes in the farm’s nutrient management plan or manure transfer agreements. The agency will be understanding and helpful during extreme weather conditions and emergency situations. Permitted farms are also required to maintain approximately 16 inches of freeboard and emergency volume (12 inches of freeboard plus an emergency volume equal to a 25 year 24 hour rain event, which in Michigan is generally about 4 inches of rain). Farms with less than the required freeboard and emergency volume are in violation of their permit and are encouraged to contact MDEQ.
Hopefully the rain and wet weather will soon by behind us. We could all use some sunshine and drying weather. Until that time continue to monitor manure storage structures aiming to prevent a severe environmental event.