Solid Waste Management Program fact sheet
Division of Environmental Quality Director: Ed Galbraith

This fact sheet addresses management alternatives and regulatory requirements for wastes (screenings) generated in cleaning and processing seed crops such as fescue, rice, wheat, corn, soybeans and cotton. Since seed-cleaning wastes are regulated as solid waste under state and federal laws, they must be managed in compliance with these laws, and with other applicable requirements.

Three programs of the Missouri Department of Natural Resources administer and enforce requirements that may affect management of seed-cleaning wastes. They are the Air Pollution Control Program, Solid Waste Management Program and Water Protection Program.


  1. Passive composting: compost piles are not turned and free oxygen is not present, resulting in anaerobic conditions. This type of composting usually requires several years to obtain stable compost and results in increased leachate production and odorous emissions. Passive composting as a management method for seed-cleaning wastes may require more environmental controls such as berms, buffer zones, retention ponds, etc., to help reduce pollution.
  2. Active composting: compost piles are turned frequently or other aeration is provided to maintain adequate oxygen (aerobic) conditions. Supplements are added as necessary to obtain optimum moisture and maintain proper carbon and nitrogen ratio for complete composting. Composting is normally completed within 120 days.
  3. Compost site size: the area within the composting perimeter including space for unloading, storing and handling materials and finished compost. It does not include buffer areas, parking lots, maintenance facilities and stormwater control basins.
  4. Buffer area: the grassed area down gradient of the storage and compost site.

Solid Waste Management Program Requirements and Information
The Missouri Solid Waste Management Law and regulations provide several options for managing wastes generated during seed cleaning:

  1. Disposal in a permitted sanitary landfill. Some seed-cleaning wastes, such as those that easily become airborne, may need to be managed as special wastes according to the Special Waste, Fact Sheet--PUB2050.
  2. Management as a permit-exempt solid waste activity under 10 CSR 80-2.020(9), provided pollution, a public nuisance or a health hazard is not created. Permit-exempt alternatives include:
    1. Using the seed-cleaning wastes in normal farming operations; using the seed-cleaning wastes in the processing or manufacturing of other products
    2. Some types of composting. However, all composting operations must comply with the requirements of the Water Pollution Control Branch. Co-composting seed wastes with municipal solid waste and/or sewage sludge requires a solid waste processing facility permit for construction and operation.

Water Protection Program Requirements and Information

Water Pollution Control Permits
Storage, treatment or disposal of seed-cleaning wastes may require permits under the Missouri Clean Water Law, Chapter 644, RSMo, and regulations 10 CSR 20-6.010, 6.015 and 6.200. Permits issued under these rules are joint state and federal permits. The department considers seed-cleaning waste storage and composting operations to be point sources and water contaminant sources due to the potential generation and discharge of leachates, especially from improper storage, composting or on-site disposal. Discharging untreated leachate during dry weather or stormwater runoff may pollute receiving water bodies.

Permit Exemptions
A water pollution control permit is not required for the following:

No Exposure Certification for Exclusion from NPDES Stormwater Permitting
Facilities that divert stormwater from contacting stockpiles and compost sites and operate as no discharge may apply for an exclusion from a stormwater permit, renewable every five years.

Permit Required
Regardless of the size of the site, Missouri law requires a water pollution control permit if solid waste or more than 5 percent sewage sludge is to be composted with the seed-cleaning wastes. However, adding amendments such as fertilizers, which may help the composting process, does not require a permit if the exemptions above apply.

Air Pollution Control Program Requirements and Information
Like many other industries in Missouri, industries that generate seed-cleaning wastes (seed chaff) are subject to the following state air pollution control regulations:

  1. All industries that generate seed chaff and vent these emissions through a stack must comply with 10 CSR 10-6.220, Restriction of Emission of Visible Air Contaminants. This rule sets a maximum allowable emission or opacity of visible air contaminants that can be discharged from a stack at a facility. Dust and particles emitted to the air when seeds are processed or seed chaff is separated may cause opacity problems unless cyclones, enclosures, filers or other mechanical equipment is used and maintained in good operating condition to prevent emissions from escaping to the outside air.
  2. All industries that generate seed chaff must comply with 10 CSR 10-6.170, Restriction of Particulate Matter to the Ambient Air Beyond the Premises of Origin. This rule restricts fugitive emissions of particulate matter (or dust) from the air beyond the property of origin. Fugitive emissions are those that do not come from a stack. Blowing particles from an uncontained or uncovered seed chaff pile may pose fugitive emission problems. Covering the pile or keeping it moist should reduce this problem. This can also include dust from unpaved haul roads within the property boundary, which usually can be controlled with a dust suppressant or regular application of water.
  3. All industries that generate seed chaff must comply with 10 CSR 10-6.045, Open Burning Requirements. For purposes of this rule, the Air Pollution Control Program considers seed chaff to be trade waste and therefore, prohibits open burning of seed chaff or any other wastes generated at businesses with few exceptions.
  4. All industries that generate seed chaff must comply with 10 CSR 10-6.165, Restriction of Emission of Odors, which restricts excessively odorous fumes. The most common source of odors from seed chaff is a chaff pile that is being improperly composted. Proper composting should not result in a noxious odor.

Finally, all facilities should determine the applicability of a construction or operating permit from the Department of Natural Resources’ Air Pollution Control Program. If unsure, please feel free to request a permit determination by sending a written request to the Air Pollution Control Programs’ Permitting Section at P.O. Box 176, Jefferson City, MO 65102. Should you be found operating or constructing without the appropriate permits, you could be subject to enforcement action..

All of the prior information is intended to assist you in maintaining compliance and avoiding enforcement actions. We appreciate that you recognize the importance of preserving Missouri’s natural resources and all of your efforts to maintain compliance with the statutes and regulations of Missouri.

Missouri Department of Natural Resources
Air Pollution Control Program
P.O. Box 176
Jefferson City, MO 65102
573-751-4817 or 573-751-5401

Water Protection Control Program
P.O. Box 176
Jefferson City, MO 65102