Winter Manure Application Requirements for All Pig Farms

Phase III of the Resource Guide Project

In an on-going effort to educate farmers about the Illinois EPA Livestock Rules, information is being provided by the collaborative work of the Illinois Agricultural Coalition which includes: Illinois Beef Association, Illinois Farm Bureau, Illinois Milk Producers’ Association, and Illinois Pork Producers Association. Farmers may contact any of these organizations to request a free copy of a Resource Guide on the EPA Rules.


As the season transitions from fall to winter, there are numerous items that pork producers must do to prepare for the changing weather. One item that might often get overlooked is ensuring that manure is properly applied. There are specific requirements that pertain to all pig farms when applying manure during the winter.


Fall is a busy time with harvest and field activities to be completed before the first snow flies. Emptying pits and manure storages is typically a priority after the crops come out. Getting manure spread in a timely manner at optimal field conditions is always a priority for pork  producers. Responsibly applying manure ensures proper utilization of the nutrients and lessens any potential negative environmental impact. Manure application during the winter has a greater risk of runoff due to frozen, ice or snow-covered ground.


The Illinois Environmental Protection Agency (IL EPA) rules for agricultural related pollution include specific provisions for applying manure, whether liquid or solid, to frozen, ice or snow-covered ground. Frozen ground is defined by the IL EPA as soil that is frozen anywhere between the first half inch to eight inches of soil as measured from the ground surface.


Pork producers should do EVERYTHING in their control to avoid having to surface apply manure when ground is frozen, ice-covered or snow-covered. This includes emptying manure storages in the fall. Farmers should also consider transferring manure to other manure structures if there will not be enough storage available to last until spring.


If no other options exist and winter application is absolutely necessary, then certain criteria must be followed. Manure application should be limited to areas with less than 5% slope or with adequate erosion control practices. Be sure to select fields with the most residue cover, such as fields with cornstalks rather than bean stubble or fields with a cover crop. Apply manure far away from any surface waters or conduits to surface waters such as tile inlets, grass waterways or field ditches. Farmers should consider reducing the manure application rate and applying only as much manure as necessary until a better application window becomes available.   


If you are an Unpermitted Large CAFO or Permitted CAFO, your options for winter manure application are much more limited. An Unpermitted Large Swine CAFO is a farm that confines 2,500 head of swine weighing 55 pounds or more OR 10,000 swine weighing less than 55 pounds for more than 45 days in a twelve month period. Permitted CAFOs could be any size swine farm that has a National Pollution Discharge Elimination System (NPDES) permit with the IL EPA.

For Unpermitted Large CAFOs and Permitted CAFOs, surface application on frozen, ice or snow covered ground is PROHIBITED, unless ALL of the following requirements are met:

  • There are no practical alternatives to transfer or dispose of the manure at any other facility or location.
  • Manure cannot be injected or incorporated within 24 hours of application.
  • Prior to December 1, the owner/operator has taken steps to provide 120 days of storage, but those steps have failed and the storage volume is insufficient.
  • The owner/operator has notified IL EPA in writing by December 1 that the CAFO has less than 120 days of manure storage available.
  • A discharge from the storage structure to surface waters is expected.


Regardless of whether manure is actually applied in winter, Unpermitted Large CAFOs wanting to qualify for the Agricultural Stormwater Exemption and Permitted CAFOs must have a winter application plan, which includes the following requirements:

  • ¼ mile setback from non-farm residence
  • No discharge is allowed during the manure application
  • Surface application on frozen ground shall not occur within 24 hours preceding a forecast of 0.25 inches of precipitation.
  • Surface application on ice or snow-covered ground shall not occur within 24-hours preceding a forecast of 0.10 inches of precipitation.
  • Fields where manure is applied on frozen, ice or snow-covered fields:
  • Must anticipate 7 days of below-freezing temperatures following the application
  • Must visually monitor runoff from the site until ice/snow melts
  • Must report any runoff as a discharge to IL EPA, using the report protocol


Requirements for field selection for Unpermitted Large CAFOs and Permitted CAFOs conducting surface land application on frozen, ice or snow-covered ground must also include:

  • Adequate erosion and runoff control practices exist
  • Surface residue or vegetative buffers of 200 ft. between land application area and surface waters, grassed waterways, tile inlets or other conduits to surface water.
  • 5% or less slope
  • Field erosion soil loss less than T (erosion factor for soils available from NRCS) and phosphorus levels less than 300 pounds/acre
  • Normal setbacks from surface waters, wells, etc. are multiplied based on field slope


Let’s look at an example. Steve owns a 4,800 head wean to finish barn. Steve does not have any runoff from his manure or dead animal composter and is not required to get a permit with IL EPA. Steve would be an Unpermitted Large Swine CAFO. He plans to spread the manure after his crops are out, but a wet fall prevents him from applying any manure. He knows that he will not be able to wait until spring to apply manure. Steve is prohibited from applying any manure on frozen, ice or snow-covered ground, UNLESS he contacts the IL EPA in writing by December 1 to explain the situation. He must then follow the rest of the requirements for winter manure application for Unpermitted Large CAFOs. 


Another example – Dave has an older 1,200 head finisher barn that has less than 6 months of manure storage. He should do everything possible to avoid applying manure when fields are frozen, ice or snow-covered. If he must spread manure in any of these situations, he must be sure to follow the guidelines listed above to ensure there is no runoff from the manure application.


For additional questions about winter manure application or other questions related to the IL EPA Livestock Rules refer to the Swine Resource Guide or contact the IPPA office.