Avert and prevent manure storage spills during this rainy season
Assess and monitor outdoor manure storage systems during this rainy season
April 29, 2011 - Author: Natalie Rector, Michigan State University Extension
Rain and outdoor manure storage are battling it out this spring. The more rain, the more freeboard disappears in the storage and the less opportunity to spread manure without getting stuck. What to do?
There are no simple solutions to the current situation, but thinking through your specific situation, and monitoring it daily can help prevent, or at least minimize, environmental risks and potential regulatory issues.
So, what should you do? Do anything you can to reduce liquid storages before they are dangerously close to overflowing. Even relieving a few inches off the top will buy some time and reduce stress on the storage system. Options may include transferring manure to another system, hauling to the driest field you have or assessing if you can get on any alfalfa field without getting stuck.
Don’t make a bad situation worse. If land applied, be sure that the manure is not at risk of running off to surface waters. Tile drained fields provide another risk during wet times. Be cautious by taking appropriate steps to insure land applied manure does not reach surface inlets or tile drains.
Outside manure storages should be designed with freeboard to deal with exactly the weather we have been having. Slightly different requirements for freeboard exist for permitted and non-permitted farms. In general, an outside storage, especially a slope sided, earthen storage, should have at least 16 inches of freeboard.* The late spring and excessive rains in some parts of Michigan may be causing the freeboard to be consumed by rain and runoff. As rain fills up this freeboard, it may put engineering stress on the integrity of the structure. If the stress results in a break or overflow of the storage, thousands of gallons could quickly exit the manure storage. A manure storage that captures runoff from around the farmstead, in addition to direct rainfall, obviously fills up even faster. Any clean water that can be diverted from reaching the manure storage would help now and in future rainy weather.
For all storage structures, especially earthen, cautiously walk the perimeter of the storage daily if necessary, based on your rainfall amounts, weather forecasts and storage situation. Recognize that berms for earthen storages, just like fields, may be water saturated and weakened. Assess how solid the sides are, looking for low points or areas with lower structural integrity. EACH farm location has unique risks of manure reaching surface waters. ASSESS your risk, consider what the worst case scenario might be and think through a PLAN to address that situation. Knowing the down slope direction from the storage will help you think through what critical features are along that path and help you know how critical the risks could be. Know how to get earth moving equipment on site immediately and plan where potential berms would need to be built to divert the flow from reaching surface water, neighboring property or road ways. Even when there are not imminent risks to surface waters, have plans in place to contain, control and stop manure from moving overland.
For permitted farms, allowing manure to exceed the freeboard limit is a permit violation, even if a release does not occur. Contact your regional Michigan Department of Environmental Quality Staff and file a report. They will work with you to seek an emergency solution.
If your farm already has a spill and release plan now is the perfect time to review that plan. Does the plan adequately address your current situation? If so follow it. If not, update the plan to reflect obvious needs. And if your farm doesn’t have a written plan, you can learn how to do one on the MAEAP website, by clcking on MSU Extension bulletin E-2575, Emergency Planning for Farms.
Communicate precautions and plans with all farm employees and family members. Have phone numbers posted for emergency services and neighbors with equipment that could assist.
In the event that a manure storage breaches and manure reaches surface waters, contact the Pollution Emergency Alerting System hotline immediately at the Department of Environmental Quality: (800) 292.4706 or Michigan Department of Agriculture and Rural Development: (800) 405.0101
*Freeboard is based on an outside storage needing 12 inches of available space plus the amount of a 24 hour, 25 year precipitation event, which across Michigan is generally around 4 inches. Therefore the 16 inches is used as a generality in this article. Permitted farms are required to have this available space for both sloped sided and straight sided storages that are uncovered. Non-permitted farms having a straight sided storage, such as concrete or steel, can have 6 inches of constant freeboard, and then room for the 24 hour, 25 year storm event, again approximately 4 inches in Michigan, adding up to 10 inches.