Composting agricultural wastes

Composting in Colorado

In general, commercial composting facilities are regulated by the Hazardous Materials and Waste Management Division. Section 14 of 6 CCR 1007-2 (Regulations Pertaining to Solid Waste Sites and Facilities) provides information on the design, operating, monitoring, closure and post closure requirements for commercial composters. 

These regulations don't apply to backyard or biosolids composting, and there are several exemptions for facilities that compost agricultural wastes.  

Agricultural wastes

Under Section 14 of 6 CCR 1007-2, Part 1, ‘agricultural wastes’ means all discarded or residual plant materials or animal materials that directly result from the raising of crops or animals, including animal manures, that are:

  • returned to the soils as fertilizer, soil conditioners or compost or
  • are composted to return to the soils, or
  • are used for other agricultural purposes.

In addition, agricultural waste means all carcasses and carcass by-products resulting from any mass livestock mortality that is the result of an all-hazards event or depopulation ordered by the state veterinarian or other appropriately designated authority.

Generally exempt - agricultural waste only

Facilities that compost ONLY agricultural waste are exempt from Section 14 provided:

  • Finished compost distributed off-site meets the specifications for compost established by the CDA. 

 

Conditionally exempt - agricultural waste and imported wood, leaves and untreated lumber (finished product can only be applied to agricultural land)

Facilities that compost agricultural waste generated on-site AND imported wood chips, tree branches, sawdust, leaves or untreated lumber are considered conditionally exempt provided they comply with the following; 

  • Importation of wood chips, tree branches, sawdust, leaves or untreated lumber occurs only in quantities necessary for effective composting of the agricultural waste generated on-site; 
  • Storage of imported wood chips, tree branches, sawdust, leaves or untreated lumber is limited to nine (9) months and the owner/operator of the facility maintains records to demonstrate adherence to this time limit; 
  • The composting facility is operated in such a manner that noise, dust, and odors do not constitute a nuisance or health hazard and does not cause or contribute to surface or groundwater pollution; 
  • The facility complies with all CDA requirements and specifications; and 
  • The finished compost is only used on agricultural zoned property, as defined by the local requirements.

 

Class I, II, and III composting facilities - agricultural waste mixed with other materials (finished material can be distributed to the public)

Facilities that compost a variety of materials along with agricultural waste are subject to Section 14 of 6 CCR 1007-2, Part 1 and will need to meet the requirements for a Class I, II, or III composter depending on the amount and type of feedstock that is processed. These requirements also apply to facilities that only import wood, leaves, and untreated lumber, but want to distribute a finished product to the public. 

This includes materials like vegetative wastes, food residuals, food processing waste, biosolids, fats, oils, greases, dairy manufacturing wastes, dissolved air flotation (DAF) skimmings, and paunch. 

 

Other general composting exemptions

Section 14 does not apply to backyard composters or permitted wastewater treatment plants that compost biosolids. 

 

Contacts

Hazardous Materials and Waste Management Division 
Jace Driver, Solid Waste Permitting Project Specialist
303-691-4059
jace.driver@state.co.us

 

Environmental Agriculture Program 

Environmental Agriculture county contact map

Environmental Agriculture county contact list

 

Colorado Department of Agriculture 
Laurel Hamling, Program Administrator
303-869-9096
laurel.hamling@state.co.us