May 20, 2008 | General

Regulating Source Separated Organics Composting Sites

BioCycle May 2008, Vol. 49, No. 5, p. 42
Does the regulatory climate in various states affect the growth of the SSO composting industry? A survey illustrates various approaches to oversight and facility classifications.
Judy Purman

COMPOSTERS have learned through the “school of hard knocks” that processing source separated organics (SSO) and producing a useable finished product is certainly an easier task than composting mixed municipal solid waste (MSW). We have also learned that ultimately, composting SSO is not much more difficult than composting yard trimmings. Accepting only clean material for composting and good process control are keys to success.
How do specific states regulate the composting of SSO? What are existing regulations? How is the term “source separated organics” defined? The following is a review of both definitions and regulations governing SSO compost facilities relative to other types of composting facilities for California, Colorado, Minnesota, Oregon, Texas, Washington and Wisconsin. Additional states are being surveyed so that a complete list of state SSO regulations will be available later this year and posted at
A comparison of statutory definitions of the terminology reveals that some states classify SSO as MSW, and some consider SSO as a separate waste stream. Source separation is defined by each state, but not every state defines “food waste” as a distinct material type. Terms such as “putrescible,” “garbage” and “vegetative wastes” are used interchangeably. California is the only state in our sampling that does not include SSO in the definition of MSW. Definitions of the term “source separation” for the states surveyed are below, as is the year the state adopted the statute. Only California, Oregon and Wisconsin have specific definitions for food waste.
California (1995): Material separated from the solid waste stream by the generator of that material. It may also include material from a centralized facility, as long as it was kept separate from the waste stream prior to receipt by that facility, and the material was not commingled with other materials during handling. Food waste is any material that was acquired for animal or human consumption, is separated from the municipal solid waste stream and does not meet the definition of “agricultural material.” Food material may include material from food facilities as defined in Health and Safety Code section 113785, grocery stores, institutional cafeterias (such as prisons, schools and hospitals) or residential food scraps collection.
Colorado (2007): Solid waste segregated at the point of generation for special handling, disposal, composting or recycling.
Minnesota (1997): Mixed municipal solid waste that is: 1) Separated at the source by waste generators for the purpose of preparing it for use as compost; 2) Collected separately from other mixed municipal solid wastes; 3) Comprised of food wastes, fish and animal waste, plant materials, diapers, sanitary products and paper that is not recyclable because the commissioner has determined that no other person is willing to accept the paper for recycling; and 4) Delivered to a facility to undergo controlled microbial degradation to yield a humus-like product meeting MPCA’s Class I or Class II, or equivalent, compost standards and where process residues do not exceed 15 percent by weight of the total material delivered to the facility.
Oregon (2005): Person who last uses recyclable material separates the recyclable material from solid waste. The term used for SSO is green feedstocks, defined as materials low in substances that pose a present or future hazard to human health or the environment and are low in, and unlikely to support, human pathogens. Green feedstocks include, but are not limited to, yard debris, animal manures, wood waste, vegetative food waste, produce waste, vegetative restaurant waste, vegetative food processor by-products and crop residue.
Texas (2004): Organic materials from residential, commercial, industrial and other community activities which, at the point of generation, have been separated, collected and transported separately from nonorganic materials, or transported in the same vehicle as nonorganic materials but in separate compartments. SSO may include, but is not limited to, yard trimmings, clean wood materials, manure, vegetative material and paper. Yard trimmings and clean wood collected with white goods, as in brush and bulky item collections, will be considered SSO under these rules.
Washington (2003): Separation of different kinds of solid waste at the place it originates. Food waste is classified as “garbage” and defined as animal and vegetable waste resulting from the handling, storage, sale, preparation, cooking and serving of foods.
Wisconsin (2005): No definition is established for source separation. Food waste is defined as discarded materials resulting from the handling, processing, storage and consumption of food. Source separated materials include yard waste, clean chipped wood, farm crop residue, farm animal manure, animal carcasses or vegetable food waste.
Common exemptions from regulation are generally consistent for the sampled states, including household backyard composting, on-site agricultural composting and very low quantities of materials to be composted (e.g., less than 500 tons/year). In general, compost produced from exempt facilities is required to be used on site by the composter.
Common siting criteria include buffer distances from the “waters of the state” (wells, wetlands, lakes, streams, rivers), neighbors and airports. Roads leading into and out of facilities have to be of good quality and regularly maintained.
Facility plan requirements include signage with name, address, owner, accepted materials, and hours of operation; list of acceptable and unacceptable materials; detailed outline of material flow within the facility; and equipment specifications.
Operational criteria requirements include specific operational times for processing materials (how long is the material to be held at receiving, mixing, active composting, curing, finished product stockpiling); documentation of process including pile temperature to document PFRP (process to further pathogen reduction, based on USEPA 40CFR Part 503), moisture levels, feedstock analysis in some cases, and finished product analysis; leachate management, run-on/runoff prevention, minimization of ponding; proper storage and disposal of reject material; and detailed annual reporting.
Performance standards include no significant adverse impact on air, water or soil, and compost quality to meet specifications before use. Standards for finished product quality include caps on heavy metal content, documented pathogen reduction, maturity indicators and low levels of noncompostables.
Regulation differences are displayed in Table 1 (Web Extra), which compares regulations according to state agency, parameter regulated, allowable composting system, operator certification requirement, and operational parameters such as surface and groundwater regulation, pad requirements, finished product testing standards and air emission requirements.
Of those examined, California’s regulatory infrastructure is the most extensive. The California Integrated Waste Management Board (CIWMB) oversees regulations in the state. Specific standards exist for siting and operating compost facilities. These include: Regular schedule of site and feedstock inspections; Recordkeeping including public complaints, injuries, etc; Feedstock quality control; Pathogen reduction; Regular sampling protocol; Finished product standards; and Site closure plans.
However, other regulatory agencies exert control over facilities. These include local health entities, regional water quality control boards, air quality management districts, local land use authorities and fire authorities.(
Colorado has established a matrix of permitting requirements based on type and quantity of feedstock and type of business. Three different types and four classifications are included in the matrix. Type 1 feedstocks include agricultural crop residues, manure, untreated wood wastes, and source separated yard, paper and green wastes. Type 2 feedstocks include animal material and source separated food waste. Type 3 feedstocks include biosolids, solid waste, processed solid waste and sludges.
Classes I, II, III, IV and classification as “pilot project” distinguish between feedstock types, quantities and the purpose for composting. All have minimum standards of operation which include: Control of surface water flowing onto the site (run-on) and prevent surface water from leaving the site (runoff); Control on-site and prevent off-site nuisance conditions such as noise, dust, odors, vectors and windblown debris; Prevent water pollution at or beyond the site boundaries; Control access to prevent illegal dumping; and Submission of an annual report and specifications of records to be maintained.
Design and operations plans for Types I, II and III facilities include: Site maps and plans including potential environmental impacts; Capacity limits, feedstock types and quantities; Site perimeter controls; Detailed description of composting operation; Surface water control system design, construction and maintenance, leachate collection; Potential effects on ground and surface water, need for a pad, monitoring; Closure plans; Contingency action plans; Compost sampling and quality assurance; and Pathogen reduction. (
Minnesota composting facilities are regulated by the feedstock they process. There are two different permitting categories: Permit-by-rule and a permit for composting municipal solid waste.
All yard waste facilities are permitted through the permit-by-rule process. This involves filling out a two-page form specifying ownership, location and proximity to the waters of the state for the Minnesota Pollution Control Agency (MPCA). An annual report is required, which outlines how much green waste went into the facility and how much product went out during the calendar year. Analysis of one sample of finished compost is required per year.
For all other compostable materials, a facility is required to be permitted as an MSW composting facility. In other words, even though a facility is processing SSO, it must meet the same regulatory requirements as a plant composting mixed MSW. In addition, the state’s definition of “source separated” includes the requirement that no material is considered source separated if it is cocollected with any other material. Commingling yard waste with food scraps and nonrecyclable paper in a truck, by definition then, excludes both of them from being source separated and therefore, from being exempt from the 17 percent solid waste management tax. Yard trimmings are often used as a bulking agent for food waste. This definition requires that food waste and yard trimmings to be trucked to the same facility separately.
The MSW composting regulations are very detailed and require the following: Roads designed to prevent traffic congestion, traffic hazards, dust and noise pollution; Protection of surface and groundwater through the construction of an impermeable pad sloped to a retention pond; Composting must be aerobic and in vessel; Facility must be operated to control nuisance odors and prevent vector attraction; Only identified feedstocks may be accepted; Pathogen reduction and destruction must be documented; Required plans and procedures for pathogen reduction and sampling and analysis, management of storm water, leachate and nuisance odors, a contingency action plan and neighbor relations/managing complaints; and The finished product must be analyzed and meet specific requirements before it is marketed. An annual report must be prepared and submitted.(
The Oregon Environmental Quality Commission adopted regulations that pair feedstock type and quantity with three sets of regulations (A, B, C) to establish three types of permit categories – Registration, General permit and Full permit. Set A regulations are the least restrictive, and Set C the most.
The composting Registration permit is for facilities utilizing more than 20 tons of green feedstocks for composting in a calendar year, or facilities utilizing more than 20 tons and less than or equal to 5,000 tons of feedstocks, which are exclusively yard debris and wood waste, in a calendar year. These operations must comply with Set A regulations. The General permit is for facilities utilizing more than 2,000 tons of green feedstocks for composting in a calendar year, or utilizing more than 5,000 tons of feedstocks, which are exclusively yard debris and wood waste, in a calendar year. They must comply with Sets A and B regulations. The Full permit is for facilities utilizing more than 20 tons of feedstocks for composting during a calendar year that include any amount of nongreen feedstocks. These operations must comply with Sets A, B and C regulations.
Regulation Set A requires an odor minimization plan, mass balance calculation, water quality protection, operations and maintenance manual and records of incoming feedstocks. Regulation Set B requires design of physical features of the site, plan for utilization of processed compost, facility closure plan, scale drawings, all-weather access road, fire protections, control of access to the site, control of and methods to minimize noise, vectors, dust and litter and proper storage of feedstocks and residues. Regulation Set C requires a protective layer underneath compost processing and feedstock areas, pathogen reduction and proper techniques for salvaging noncompostable materials. (
Texas regulations are based on feedstock type, with cleaner materials such as yard trimmings and agricultural wastes requiring fewer conditions. Composting sites are classified into one of four permit tiers: Exempt are composting or mulching of manure, clean wood, source separated yard trimmings, paper or vegetative matter. Notification is required for composting of meat, fish, dairy feedstocks, dead animal carcasses, and meat/vegetable oils and greases. Registration is required for composting municipal sewage sludge, disposable diapers and paper sludges. A permit is required for composting grease trap wastes and MSW.
The most complex rules apply to the most difficult feedstocks and include the following requirements: Protection of surface and groundwater; Environmental impact analysis and minimization; Specifications on feedstocks; Requirement for aerobic composting; PFRP documentation; End product standards; Certification of operator; Facility access controls; Contingency action plans; and Air quality monitoring. (
Washington statutes outline composting requirements based on the type of feedstock, coupled with the potential for human and environmental harm. The local jurisdictional health department (JHD) has the authority to permit a nonexempt facility.
Four types of feedstocks with associated “harmfulness” levels are laid out. Type 1 include SSO, yard and garden wastes, wood wastes, agricultural crop residues, wax-coated cardboard, preconsumer vegetative food wastes, and other similar source separated materials that the JHD determines to have a comparable low level of risk in hazardous substances, human pathogens and physical contaminants. Type 2 feedstocks include manure and bedding from herbivorous animals that the JHD determines to have a comparable low level of risk in hazardous substances and physical contaminants when compared to a Type 1 feedstock. Type 3 feedstocks include meat and postconsumer SSO or other similar source-separated materials that the JHD determines to have a comparable low level of risk in hazardous substances and physical contaminants, but are likely to have high levels of human pathogens. Type 4 feedstocks include MSW, postcollection separated or processed solid wastes, industrial solid wastes, industrial biological treatment sludges, or other similar compostable materials that the JHD determines to have a comparable high level of risk in hazardous substances, human pathogens and physical contaminants.
Facility regulations include the following: Provide all-weather roads designed to prevent traffic congestion, traffic hazards, dust and noise pollution; Protect surface and groundwater – separate storm water from leachate by designing storm water run-on prevention systems, collect any leachate generated from areas of feedstock preparation, active composting and curing into a containment area (pond, tank); Pond specifications include a liner, allowances for wave action, overfilling and precipitation; Composting must be aerobic with attention paid to porosity, nutrient balance and pile oxygen, moisture, temperature and retention time; Compost pad specifications include grading to prevent ponding, run-on and runoff, construction materials (concrete with sealed joints, ashpaltic concrete or soil cement); Other materials are acceptable if their use complies with specifications.
Facilities receiving Types 2, 3 and 4 feedstocks must be operated to control nuisance odors, prevent vector attraction (flies and rodents), accept only identified feedstocks, have trained personnel on site and document pathogen reduction activities. Composting methods allowed are in-vessel, aerated static pile, windrow. Other requirements include: Analyze finished product (tests required and testing frequency vary with feedstock type); Required plans and procedures, ensuring only acceptable waste is tipped, and covering mass balance calculations and material flow; Pathogen reduction, sampling and analysis, management of storm water, leachate and nuisance odors; and Safety, fire and emergency and neighbor relations/managing complaints. An annual report outlining throughput in detail must be prepared and submitted to the regulatory authority. (
Of our state sampling, Wisconsin regulations are the least developed when it comes to SSO; the state also has the fewest SSO composting sites. Composting operations in Wisconsin are regulated by the Department of Natural Resources. Materials approved for composting include “yard waste, clean chipped wood, farm crop residue, farm animal manure, animal carcasses and vegetable food waste.”
Backyard composting, composting on-farm (either crop residue or manure) and yard waste sites composting less than 50 cubic yards are exempt from regulation. Facilities processing less than 20,000 cubic yards of yard waste and clean wood, and those processing less than 500 cubic yards of food waste are also exempt from all regulations except for criteria related to site selection. Siting requirements state that no facility can be located within a floodplain, within 5 feet of a seasonal high groundwater table, within 250 feet of any private or 1,200 feet of any public water supply, within 250 feet of any navigable lake, pond, river or stream.
Nonexempt facilities must meet minimum operational standards. These include: Wastes must be source separated and nonbiodegradable materials removed before processing; Wastes must be debagged within 24 hours, sized, mixed to a minimum carbon-nitrogen ratio of 12:1, moistened at 50 to 60 percent water, aerated and fully composted; Finished product must be stabilized, free of sharp objects and free of toxins, and it must be marketed to “prevent excessive stockpiling;” Facility must be operated in a nuisance-free and environmentally sound manner; Runoff must be managed as leachate and collected either in a basin or tank; All composting and storage of waste materials and compost must take place on a low permeability pad constructed of either asphalt, concrete, recompacted clay or other approved material; and Detailed plans for all aspects of operation must be submitted and approved. (
Though some states regulate source separated organics as MSW, others have developed SSO-specific regulations, recognizing as our industry matures that composting SSO may not require the same stringency as composting mixed MSW.
Perhaps the Oregon Department of Environmental Quality described the purpose of regulation best when it stated that its goal (for developing and revising compost regulations) is to develop quality regulations that protect human health and the environment while continuing to promote effective composting in Oregon. Indeed, well developed permit requirements can lead to the development of a more extensive statewide infrastructure to capture and recycle SSO. A more extensive infrastructure allows for collection route density, which in turn allows for an economically healthier infrastructure overall.
Judy Purman directs The Purman Group, LLC (, working in partnership with clients and other professionals to plan and implement sustainable solutions for a variety of today’s challenges including literacy action, waste minimization and management strategies, and streamlining operational and administrative systems.

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