Compost Operator

Guidebook

Best Management

Practices for Commercial Scale Composting Operations

March 2015 Copyright February 2011

Michigan Recycling Coalition PO Box 10070 Lansing, MI 48901 Phone: 517-974-3672 MRC Executive Director Kerrin O’Brien [email protected]

Editors: Nicole Chardoul, Kerrin O’Brien, Beth Clawson, Matthew Flechter

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MICHIGAN COMPOST OPERATOR TRAINING GUIDEBOOK

Table of Contents

Part 1: Core Principles Chapter 1: Introduction to Composting Composting Defined ...... 1-2 Chapter 2: Biology & Core Principles Composting Process ...... 2-2 Microbiology ...... 2-3 Aerobic vs. Anaerobic Conditions ...... 2-5 Composting Methods ...... 2-6 Critical Factors Table ...... 2-7 Chapter 3: Characterization and collection of Organics Characteristics of Organic Materials ...... 3-2 Collection Options for Yard Clippings ...... 3-3 Best Collection Practices ...... 3-4 Comingled Materials ...... 3-5 Collection Equipment Options ...... 3-9 Food Waste ...... 3-13 Characterizing Food Waste ...... 3-14 Working With Generators ...... 3-15 Working With Haulers ...... 3-20 Part 2: Site Design & Operations Chapter 4: Facility Siting and Site Design Site Planning ...... 4-2 Odor and Site Design ...... 4-3 Site Capacity and Sizing ...... 4-5 Site Layout ...... 4-7 Area Requirements ...... 4-8 Site Selection ...... 4-10 Site Design ...... 4-11 Site Drainage Information ...... 4-14 Chapter 5: Operations Incoming Material Stream ...... 5-1 Quantity of Incoming material ...... 5-4 Pre-processing ...... 5-6 Compost Production ...... 5-7 Composting Systems ...... 5-8 Compost “Recipe”...... 5-10 Monitoring the Compost Process ...... 5-12 Composting Equipment ...... 5-13 Staffing ...... 5-18 Low Odor Operations ...... 5-20 Managing Operations Summary ...... 5-22 Part 3: Marketing & Finance Chapter 6: Facility Financing Establishing Project Credibility ...... 6-2 Financing Capital Costs ...... 6-5 Financing Operating Costs ...... 6-9 Table 1: Financing Sources for Facility Capital ...... 6-12 Table 2: Financing Sources for Operating Costs ...... 6-13 Chapter 7: Compost Marketing Concepts & Tools Benefits of Compost ...... 7-2 Compost Market Planning ...... 7-2 Product Quality Standards & Control ...... 7-6 Compost Characteristics ...... 7-9 Market Sectors ...... 7-10 Matching Process to Market Specifications ...... 7-11 Using Compost ...... 7-14 Promotion and Distribution ...... 7-16 Part 4: Troubleshooting Chapter 8: Troubleshooting Odor Problems ...... 8-3 Temperature ...... 8-6 Dust...... 8-8 Noise ...... 8-9 Flies and other pests ...... 8-10 Inferior Final Product Quality ...... 8-11 Site-related problems ...... 8-12 Handling Neighbor Complaints ...... 8-13 MICHIGAN COMPOST OPERATOR TRAINING GUIDEBOOK Best Management Practices for Composting

Part 1: Core Principles

Michigan Recycling Coalition PO Box 10070 Lansing, MI 48901 Phone: 517-974-3672 [email protected]

Best Management Practices for Composting

Introduction to Composting 1

About your Guidebook This manual presents a series of Best Management Practices for Composting which provide technical information and assistance on the operation and management of compost sites, especially those that process yard trimmings and “diminimus” (5% or less) amounts of other organic residuals. Each module in the series is designed to provide information to improve the success and viability of a composting operation with an overall goal of minimizing odor and water quality impacts while producing quality compost products. The industry continues to evolve and improve through trial and error, research, innovation, and technological development. This Best Management Practices Series and the corresponding training offer the best approaches to the current challenges of composting.

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on Municipal Solid Waste, yard trimmings and Composting Defined food scraps make up the second and third Composting is a managed, aerobic (requiring largest portions of the MSW stream, 13.2% oxygen) process in which microorganisms and 12.7% respectively (by weight). In a decompose organic materials (for example; landfill these materials undergo anaerobic leaves, grass, brush, wood, manure, decomposition and produce methane. agricultural residues, food scraps, etc.) Methane (CH4) is a greenhouse gas that yielding carbon dioxide gas (CO2), heat, remains in the atmosphere for about 9-15 water, and a stable, soil-like product called years and is over 20 times more effective at humus or compost. Understanding the trapping heat in the atmosphere than carbon biological principles of composting enables dioxide (CO2) over a 100-year period. Some the site manager to make sound operational landfills are equipped to capture, presently, decisions to control and optimize the process up to 80% of the gases produced. Most to produce a quality product. landfills are not equipped to capture landfill The Environmental and Economic Benefit of gases. According to the U.S. EPA, landfills are Composting the second largest source of methane emissions in the U.S. Composting is a way to manage organic discards to the benefit of the environment. As a fundamentally aerobic process, well- • Composting reduces the production of operated composts sites do not produce greenhouse gases in landfills that significant amounts of methane and contribute to climate change, contribute considerably less to the • Composting diverts yard clippings and production and release of climate changing food residuals from taking up valuable greenhouse gases. Additionally, experimental space in highly engineered landfills, studies have shown that carbon and sequestration in soil was increased by 6 to 40 • Compost replenishes the organic tons of carbon per hectare from the matter and nutrient value of soil. application of compost. • Compost can be used to effectively Impact on Waste Management reduce or eliminate soil erosion and filter stormwater discharge Continuing pressures have focused attention • Composting provides local jobs and on diverting yard trimmings from landfills and enhances the local economy. many states have responded by implementing yard trimmings composting Impact on Climate Change programs or even bans on the disposal of yard trimmings in landfills. Increasingly in the According to the U.S. Environmental United States, composting is used to handle a Protection Agency’s 2008 Facts and Figures variety of municipal solid wastes, agricultural

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residues (old hay/straw, animal bedding, and compost and back into the soil rebuilds manure etc.), biosolids, food scraps, and healthy soil ecosystems that control and more. Smaller scale backyard composting is reduce soil erosion, suppress disease in crops, promoted as a means of reducing the total restore and rehabilitate wetlands and amount of yard trimmings that require brownfield sites by breaking down pollutants, collection and transportation to central and reduce the need for artificial agricultural composting facilities. chemicals. The application of compost can reduce the need for irrigation by 30-70% and Composting contributes to local economies also reduce the overall agricultural demand by employing people, transforming a locally for energy. produced “waste” into a locally produced resource. In a still-relevant study conducted History and recently reaffirmed by the Institute of The origins of composting practices in human Local Self-Reliance, for every 10,000 tons of history date back thousands of years. material per year managed, if landfilled Archeological evidence suggests that animal creates one job but if composted creates four manure was used to increase food production jobs. (Waste to Wealth, 2006) Tax revenue shortly after people began cultivating food. from composting businesses also add to the Manure was mixed with straw in what community bottom-line. eventually became a fertile soil-like material. Providing a lower cost option for the There are numerous references in the Bible management of organic wastes makes and the Talmud to the cultivation of the soil composting even more valuable to a and the use of animal manure as fertilizer. community. Because composting is less One of the earliest documented agricultural resource intensive than landfilling, compost uses of manure was discovered on a set of can be managed and produced locally in most clay tablets dated to the Akkadian Empire communities. which flourished in the Mesopotamian Valley 1,000 years before Moses was born. Impact on Soil The first groups of European settlers came to The worldwide deterioration of agricultural America with the knowledge of spreading soils has made composting and soil manure to fertilize soils but lacked sufficient rehabilitation a necessity. Much research is numbers of farm animals to impact crop taking place on the benefits of compost as a production. In the early 17th century, Pilgrims soil amendment. The widespread were taught by members of the Abanaki tribe dependence on fertilizers and pesticides to add a fish to each hill of corn, a practice temporarily improves soil productivity but which many American colonial farmers does nothing to maintain soil structure and continued until the early 18th century. As the ultimately leaves the soil lifeless. The number of farm and farm animals grew, successful diversion of organic waste to

Michigan Compost Operator Training Guidebook 1-3 farmers soon discovered (or rediscovered) that mixing barnyard manure with muck soils produced a much higher quality fertilizer.

Sir Albert Howard, a government agronomist in India, developed the modern concept of composting. The Indore method called for the mixing of three parts garden clippings to one part manure or kitchen waste. Howard published his ideas in a 1940 book, An Agricultural Testament. The first advocate of Howard’s method was J.I. Rodale, founder of Organic Gardening Magazine. This technique quickly became the standard for gardeners who prefer not to use synthetic chemicals. The use of compost in agriculture, however, declined with the growing prevalence of chemical fertilizers following World War II.

Historically, most composting methods are based on practical experience rather than scientific knowledge. There has been little application of scientific principles to composting practices, but current interest in the science of composting has grown due to increasing complexities in dealing with large amounts of organic residues in a short period of time, lack of landfill space, and increasing concern about the environment.

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Best Management Practices for Composting

The Biology and 2 Core Principles of Composting

This part of the Best Management Practices Guidebook provides technical assistance in the operation and management of compost sites, specifically those that process yard waste. Each chapter of Best Management Practices (BMP’s) is designed to improve the success and viability of composting operations, with an overall goal of minimizing odor and water quality impacts during the production of quality compost products. While the industry will continue to improve through research and development, innovation, equipment developments and trial and error, BMP’s offer the best approach to the challenges of composing.

Introduction This chapter reviews the biological aspects of

composting and their role in management of Composting Process p. 2 the process. Topics include definition and description of the composting process; Microbiology p. 3 historical aspects, microbiology of Aerobic vs. Anaerobic Conditions p. 5 composting monitoring and controlling the

composting process; and characterization of Composting Methods p. 6 finished (marketable) compost. A Critical Factors Table p. 7 terminology section has been appended, as well as, journal articles related to biological aspects of composting.

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The composting process factors such as temperature, and physical In a managed environment, factors such as particle size of the materials composting is a process that being consumed. produces a valuable, quality The overall objective in managing the product (compost), and composting process is to create and maintain minimizes odor. communities of microorganisms that work together to decompose the organic matter. In nature, dead plant and animal matter is Management of the composting process decomposed slowly into humus primarily by initially requires the proper mixture of microorganisms. These organisms are ingredients based on the ration of carbon to distributed widely throughout every nitrogen (C: N ratio) in the input materials, environment on the planet. The rate at which periodic monitoring and adjustment of

these microorganisms decompose organic factors such as compost, moisture, O2 and/or

material aerobically into humus depends CO2 levels and temperature. These are some upon the relative amounts of carbon and of the factors directly associated with the nitrogen in the material mix, the availability activity of microorganisms doing the work of oxygen and moisture, other environmental (figure 1).

Figure 1: The composting process.

Raw organic materials Carbon Dioxide Gas

Water Water & water vapor

Air (Oxygen) Microbes Heat

Compost (Humus)

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Microbiology of composting Composting is a process carried out primarily Table 1: Microbial Groups by microorganisms that decompose organic Microbial Group Description materials. The major groups of microorganisms that are active during Bacteria Microscopic organisms that are composting are bacteria, actinomycetes, and very simplistic and can exist in fungi. Other organisms that complete the Psychrophilic a variety of forms and environmental conditions. diversity of decomposers include nematodes, Mesophilic Most numerous group of protozoa, and micro-arthropods. In the microbes active during Thermophilic visible spectrum are earthworms, arthropods, composting and generally larger nematodes, beetles, and other detritus considered the fastest decomposer. eating insects. Each group is diverse, with many family members that function under a Actinomycetes Similar in structure to fungi, variety of environmental conditions. We but more closely related to bacteria. Primarily aerobic, refer to all of these organisms collectively as more pronounced after easily the “soil food web.” degraded compounds are gone and when moisture and Compost typically contains large amounts of temperature is low. Generates carbon-based materials. Fungi and the “earthy smell” that is familiar to healthy soil and actinomycetes help to break the complex compost. chemical bonds releasing the nutrients necessary for other microorganisms such as Fungi (Molds) Larger than bacteria and actinomycetes, more tolerant bacterial to thrive. Their microfilaments of low-moisture and low pH transport nutrients across distances. conditions, but less tolerant of Bacteria, actinomycetes, and fungi are able to low oxygen conditions. access a larger surface area of organic Decompose woody substances and other decay-resistant material after other larger microorganisms materials better than bacteria have broken it into smaller particles. through breaking enzyme chemical bonds. Bacteria groups are classified based on the temperature ranges in which they are active, shown in Table 1. These are divided into Temperature is one of the primary indicators three groups: Psychrophilic bacteria that are of microbial activity. Figure 2 shows the active between 0°F - 55°F; Mesophilic typical temperature trend observed in a well bacteria that are active from 50°F -120°F (10 - managed compost windrow over the first 50 50°C), and the Thermophilic bacteria that are days of composting. Ranged in which the active from 110° - 160°F (45°- 70°C). different classes of microbes thrive are indicated.

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Figure 2: Idealized Temperature Profile of a Windrow Compost Pile

Mesophilic Mesophilic Phase Phase Ambient Air (Fungi become or Thermophilic active) Psychrophilic Phase Phase

As shown above, bacteria flourish in the early these are in the form of nutrients necessary stages of composting consuming the easily for plant growth. Others are “glued” together degraded materials. Bacteria will dominate by microbes to form organic chains and composting as long as conditions are polymers such as Glycine and humic acid. favorable. Fungi and actinomycetes become Table 2: Microbial Requirements most active near the end of composting, feeding on materials that are more difficult to Requirement Benefit to Microbes break down. Fungi gains advantage at low pH, while low-moisture favors both fungi and Carbon (C) Provides carbohydrates (energy) and builds microbial biomass actinomycetes. Low oxygen reduces fungi populations and aerobic bacteria populations Nitrogen (N) Provides proteins, nitrate, and increases anaerobic bacteria populations ammonia generating gasses that produce offensive Oxygen (O ) Respiration (aerobic microbes), odors. 2 facilitates metabolism Many chemical changes are occurring during Moisture Critical for promoting and the decomposition process. As sugars, maintaining activity starches, and proteins and other compounds are oxidized they produce heat, carbon pH Percent Hydrogen (H), optimal dioxide, water and compounds that are near neutrality (pH 7), normally finishes higher (pH 8). resistant to further decomposition. Many of

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Aerobic vs. anaerobic conditions Composting will occur through aerobic decomposition if enough oxygen is present You can easily throughout the pile to support the identify when reproduction of aerobic microorganisms. If your compost has the percent oxygen in part or all of the pile is gone anaerobic insufficient, then the process will become from the number anaerobic and an entirely different of neighbors community of microbes will flourish taking calling to over the process. Anaerobic microbes do not complain about require oxygen to survive. the smell. Aerobic decomposition converts organic matter into carbon dioxide gas, water, and heat, while nitrogen complexes are converted Each compound has its own unmistakable into nitrates. This will smell like fresh soil or odor. For example, NH4 based ammonia woodland. That is a byproduct of smells sharp like ammonia or fertilizer; sulfur actinomycetes activity. Anaerobic smells like rotten eggs; and VFA’s smell like decomposition converts organic matter into “rotting garbage” or “dead animal.” Aerobic carbon dioxide gas, methane gas, various composting can be accomplished by alcohols, and volatile fatty acids (VFA’s). The maintaining control of a variety of factors nitrogen complexes are converted to which affect the composting process. ammonia (gas) and sulfur compounds are Specifics on how to control these factors are converted to hydrogen sulfide gas. discussed in more detail in the chapter on operations. Compost piles can reduce by As aerobic decomposition occurs, carbon is half in both weight and size lost as CO2 gas, and nitrogen tends to be within the first couple of weeks conserved. The higher rate of carbon loss of decomposition. results in a decrease of C:N ratio of the mixture. The pH tends to rise to 8.0 to 8.5 and the volume of the composting material is reduced by 50 to 60%; while the weight is To minimize odors, the composting process reduced by 40 to 80%. must be managed to promote aerobic decomposition, unless you are composting in- vessel. In-vessel is a compost method that will be discussed in later chapters. A septic tank is one example of in-vessel composting.

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Composting methods affect biology

A variety of methods are used for large scale composting (>100 yards) of organic materials. The most common and effective methods are heap and windrow composting, on which this guidebook focuses. In windrow composting a mixture of raw organic material is placed in elongated trapezoidal piles called windrows.

Windrows with dimensions relative to their contents aerate naturally by chimney effect

or convection (figure 3): rising heat generated Finished compost curing in windrows inside the pile draws in cooler air from the There are other effective large-scale bottom and sides of the windrow. Turning composting methods such as passive systems, windrows blends the composting materials, static pile systems, and in-vessel systems that decreases particle size, releases CO2, and will be discussed in more detail later in this homogenizes ingredients to promote uniform guidebook. Smaller scale composting (i.e. decomposition increasing temperatures to backyard composting) rarely achieves high help kill pathogens and weed seeds. enough temperatures to effectively kill weed seeds and pathogens.

Figure 3: Schematic of the Chimney Effect

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Table 4: Critical Factors Overview

Factor Significance

C:N ratio A carbon to nitrogen (C:N) balance of 25:1 to 30:1 helps ensure rapid (recipe ) decomposition. C:N ratios below 20:1 tend to generate foul odors. C:N ratios above 40:1 increase composting times.

Moisture The right balance nourishes microbial organisms. Target range is 50 – 60% by weight. Excess moisture tends to limit oxygen availability and

can leach out.

Oxygen and Microorganisms need O2 to oxidize carbon which is released as CO2. carbon dioxide The aerobes die, and the anaerobes flourish, resulting in offensive

odors. O2 concentrations in the compost air greater than 5% are

recommended for rapid composting.

Temperature Heat is the result of vigorous microbial activity. 110-140°F indicate an active pile. Most weed seeds and pathogens are killed at 145°F. Temperatures above 160°F effectively stop the composting process.

Time The time to reach a stable compost is affected by C:N ratio, O2 availability, moisture, particle size, mixing, and temperature.

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Best Management Practices for Composting Characterization and Collection of Organics 3 Now that you know the science behind Characteristics of Materials p. 2 composting this chapter moves you into collecting and handling your feedstock Collection Options p. 3 materials. You will also learn how to handle Best Collection Practices p. 4 food wastes safely. Finally, you are presented with an overview of site Comingled Materials p. 5 management of these materials to help ensure the creation of a quality compost Collection Equipment Options p. 9 product with few problems. Food Waste p. 13

Introduction Characterizing Food wastes p. 14 Leaves, grass, and brush are the organic Working With Generators p. 15 components of the waste stream most often considered for composting. These and other Working With Haulers p. 20 organic materials such as food waste, wood waste, non-recyclable or soiled paper, and Considerations biosolids (waste water residuals or sludge) make up almost two-thirds of the waste that Volume: how much organic material is in the must be handled every day in every municipal waste stream? community. Managers who are interested in reducing and diverting as much material as Diversion potential: how much of that possible from disposal must consider the organic material can feasibly be composted? characteristics of organic wastes and pursue cost-effective, technically and Material characteristics: how do moisture, environmentally sound management. nutrient content, and particle size affect handling?

How much organic waste is there?

 The average household in Michigan generates yard clippings at the rate of 4.4 cubic yards per household per year, or about 1500 pounds annually. This amounts to between two and five paper bags per week (3-4 during peak grass growing season; 1-2 in mid-summer; and as many as 25 in a week in the late fall).

Michigan Compost Operator Training Guidebook 3-1  Up to 60% of all yard clippings are grass  Yard clippings are estimated to comprise and weeds generated in the growing between 18-25% of the residential waste season from May through September, stream; an additional 10-17% consists of but may only result in 30% of the total other organics, such as food, wood, and actually collected due to increasing soiled paper. mulching or “grasscycling” at the site of  Biosolids are generated at a rate that generation. ranges from 100 to 150 dry pounds per capita annually.

Characteristics of Organic Materials

Management activities including source reduction, source separation, collection, preprocessing, and ultimately composting; final product uses are affected by the mix and volume of the materials composted. This table summarizes key material characteristics.

Volume Characteristics Leaves 160 lbs/ household /yr C:N ratio: 80:1 0.8 cubic yards, loose Moisture content: 10-50% Density: 150-700 lbs/cy High carbon & mineral content Composts alone, but slowly, with little odor Grass 1,040 lbs/ household /yr C:N ratio: 15:1 2.6 cubic yards, loose Percent moisture: 60-80% Density: 400-800 lbs/cy Decomposes quickly Good nitrogen source Strong potential for odor Brush and 300 lbs/household/yr C:N ratio: 200-500:1 Tree 1 cubic yard, loose Percent moisture: 40-50% Trimmings Density:250-500 lbs/cy Very slow to break down Food 255 lbs/household/year C:N ratio: variable, typical 15:1 1.64 tons/employee/yr (food service, markets) Percent moisture: variable 0.71 tons/employee/yr (restaurants) Density: 800-1000 lbs/cy 19.29 tons/employee/yr (food processors) Biosolids 120 dry pounds/per capita/per year C:N ratio: High nitrogen Percent moisture: variable Quality of sludge variable Michigan Compost Operator Training Guidebook 3-2 Urban 300-5,000 lbs/employee/yr (manufacturers) C:N ratio: 300:1; high in lignin wood Generation rates vary tremendously depending Percent moisture: 5-20% waste on the type of manufacturing. Highest rates Density: 300-600 lbs/cy occur in the wood processing industry. Slow to compost. Requires grinding to reduce particle size Industrial Variable, depending on industry (paper mills, C:N ratio: 6:1 sludge leather, pharmaceuticals) Nutrient value can be high. Concern about contaminants varies by industry

Collection Options for Yard Clippings

An effective yard trimmings collection system and trash. Co-collection systems are includes many components, all of which must gaining attention as a method to increase function smoothly together. The physical efficiency while adding materials such as components of an effective collection system food scraps to the recovery stream. are the method used to set yard trimmings out ♦ Managing a low odor operation within the at the curb (in bags or carts, or loose) and the confines of your site. type of collection vehicle. Equipment for processing yard trimmings after they arrive at their destination for composting must be Once a service has been provided to residents, planned in conjunction with collection it is very difficult to repeal, or stop, no matter equipment. Factors affecting equipment how costly to taxpayers. When designing choices include the quantity, composition, and collection programs for brush and other yard timing of yard trimmings generation, the trimmings, it is advisable to start with minimal structure and route allocation of the existing frequency and convenience, from which the hauling infrastructure, and market community can later add or build additional specifications for the final compost product. services. For example, on-call brush collection is great for the resident, but costly to administer for a reasonable cost. Key Collection Issues

♦ Degree of source separation (i.e., woody Key Collection Considerations materials separated from soft materials Self-Haul to • Limits collection costs such as grass, leaves, and garden Drop-Off • Quality control is a problem trimmings). Site at unattended drop-off sites ♦ Type of container used, if any, affects • Provides incentive to home collection vehicle choice as well as compost processing components. • Negative impact on seniors, ♦ Reducing the number of trucks passing or physically challenged down each street for organics, recyclables, individuals

Michigan Compost Operator Training Guidebook 3-3 • Some residents expect • Costs (capital and O&M) curbside service • Service availability from • Provides some level of private sector services in sub-rural areas Funding • Charge through taxes versus Curbside • What material is set-out? user-based, with bags, tags or Collection • Is material loose or contained subscription (i.e. bags, carts, mesh fabric)? • Which materials can be commingled? Equipment • Labor (seasonal staffing, Issues lifting, safety, etc.) • Automated trucks versus loaders versus vacuums • Impact of grasscycling and home yard care practices Best Collection Practices Best collection practices can be affected by time of year and how they are collected. Contracting with a city for their leaf collection using vacuum trucks for municipal leaf collections is both cost effective and practical. However, not all residents may be able to get their leaves raked to the curbside in a timely fashion, so multiple passes may be required.

Leaves  Collect source separated; Fall 6-8 weeks; Spring 1-2 weeks Loose → vacuum truck or loader Carts → Automated packer truck Paper bagged → Packer truck Grass Clippings  Collect at curb source separated, April – September, or provide drop-off site  Carts or paper bags → Packer truck  No plastic bags!  Encourage on-site handling by generator through pricing, education incentives  Brush and Tree  Curb chip Trimmings  Bulk collect Food  Collection from commercial sector e.g. restaurants, produce markets, grocers in curb carts or wet-strength compostable bags  Food processing waste composted or transported to farmers for feed. Waste wood  Separate collection at C&D sites  Source-separated collection from businesses and contractors (pallets, clean dimensional wood, other)

Michigan Compost Operator Training Guidebook 3-4 Material separation the fall, a separate collection of leaves is very common.

The three primary residential yard Segregation of woody materials from soft, trimmings materials (leaves, grass, brush) wet materials generally increases may be completely segregated for curbside processing efficiency. However, set-out, or commingled. Alternatively, two commingling is generally easier for of the materials (typically grass and leaves) residents, thereby increasing participation may be mixed, with brush segregated. The while reducing the costs for educating level of separate collection of materials is residents on proper set-out methods. dependent on key factors including: Commingling materials also requires fewer specialized collection vehicles, thereby 1. The seasonality of generation of the reducing capital and labor costs. respective materials, 2. Available equipment to mix or grind Segregation of brush by residents is material necessary where curbside chipping is the 3. Compost market specifications, and handling method for woody waste. This 4. Potential end use. benefits site processing by eliminating the need to grind soft materials along with In locations where leaf drop is substantial in woody materials due to commingling. Commingled materials

Under a commingled materials collection program, grass clippings, leaves, brush and Separated materials other woody items such as vines, are placed in a single container, bag or pile. Under this system, brush and wood are set out separately from leaves and grass. Brush Advantages Disadvantages and wood can be piled loose, placed in bags or bins, or bundled with twine. Brush • Convenience = • Where plastic bags are collection can typically occur less frequently high participation used for collection, (quarterly, monthly) while grass collection • One collection extra labor is required truck can be used to debag would require weekly service to avoid odor • Carts and • If higher product problems. automated grades are required, loading brush separation may Grass clippings and leaves can be mechanism can be required commingled (although they occur mostly in be used • Commingled “hard” & • Potentially, less “soft” wastes must all different season, with some spring and fall collection labor is be ground at overlap), while wood wastes are generally required than for processing site bundled separately for chipping or collecting separated • Equipment to separate in bulk. materials brush from • Lower overall cost leaves/grass at the site of collection can be purchased

Michigan Compost Operator Training Guidebook 3-5 Advantages Disadvantages Contained material collection

• Increased • Increases promotion processing and education costs Some communities allow residents to place efficiency • Requires specialized yard trimmings at the curb in any labeled • Reduced site trucks (e.g., container. A second option is to designate a processing costs compartmentalized) or specific type of container. Containers • Faster 2 trucks or chipper include paper bags, reusable mesh bags, decomposition of • Potentially more cans, carts, and semi-automatic carts. soft-only wastes collection labor than • Pruning practices for a commingled are substantially method different from • May require separate Advantages Disadvantages mowing practices collection routes for • Less equipment • Initial capital costs for trucks • At the processing and potentially less containers may be high site, wood chips labor than for loose • May require specialized can be added as material trucks (automated or needed to balance • Potentially less semi-automated lifters) C:N contamination • Amount of material set- than for loose out may be limited to Loose material collection material container capacity • Material is not • May require more The greatest advantage of collecting loose litter-prone or residential storage problematic for space yard trimmings, leaves simply raked to the traffic, parking, • May need separate leaf curb, is the avoidance of purchasing any sewers collection program to containers. Also, plastic bag fragments, if • Promotes handle the large volume used in the collection process, a are avoided participation of leaves in the fall in the finished compost.

Advantages Disadvantages Plastic bags

• Convenient – • Potentially greater The use of plastic bags for yard trimmings conducive to contamination than for participation contained material pick-up is no longer a popular option because • Amount of • Requires specialized of the anaerobic odor that develops in the material set-out is equipment to move bags during the collection and because of the unrestricted materials from curb to plastic fragments that remain in the finished • Contaminants are truck compost. Plastic bags were initially used by more visible Wet material is difficult • some communities because little behavior • No container costs to handle, and may • No bags to remove cause odors; materials change was required of residents and in processing may clog street drains because plastic bags are cheaper than paper. • Material in street is However, the problems created by the use of litter-prone through plastic bags, even compostable plastic bags disruption by traffic, rain and wind often outweigh their benefit. • Street sweepings may impact the quality of the end product.

Michigan Compost Operator Training Guidebook 3-6 Non-compostable plastic bags finished compost environmental effects – including the effects on compost – of Advantages Disadvantages degradation products • May have reduced • Lowest cost • Private sector strength when wet among bag operating costs are • Breakdown does not options passed along to occur in composting • Residents are generator in the form time frame, or with familiar with this of higher tip fees. Site some bags, may break container (i.e. closure is often down too quickly (i.e. the standard threatened due to before collection at household odors. the curb) garbage bag) Added processing • • Odor remains an issue • Availability (i.e., costs from acceptance if materials are in bag special purchase of plastic bags for too long and distribution (including of bags are not compostable) are required) initial debagging, control of blowing plastic bits, and removal of plastic contaminants from final product • Cost effective debagging systems have not been demonstrated; laborers for manual debagging are nearly impossible to find and keep • Once separated from the yard trimmings Paper “kraft” yard waste collection bags and compost, plastic decompose completely. bags must be disposed of at an additional cost • Plastic fragments in compost reduce Paper bags quality and marketability Biodegradable paper “kraft” bags are an Compostable plastic bags increasingly popular method of containing yard trimmings material for collection. In • Lower cost than • Impedes processing many municipal programs, these bags are paper or mesh operations unless sold in local retail stores at a price that bags effort is made to covers the cost of the bag, or the bag plus • Possible remove the contents the costs of collecting and composting. The degradation of • Plastic fragments in the bags which, compost reduce ability of the paper bag to decompose along if true, would quality and with the bag contents is its most obvious eliminate plastic marketability advantage. One disadvantage is the higher fragments in the • Little data on the price per bag versus traditional plastic (25¢-

Michigan Compost Operator Training Guidebook 3-7 39¢ per bag, bulk pricing for paper versus 9¢/bag for plastic), but an advantage is the lower price per bag versus a compostable plastic bag ($1 per bag). Carts and bins

Advantages Disadvantages

• Fewer vehicles and • Initial investment workers required for is high if Advantages Disadvantages collection municipality or • Less expensive • More expensive • Carts are durable hauler provide than compostable than traditional • Easy for residents to carts plastic bags plastic bags load and transport to • Automated • Bag can be • Heavier than curb tipping shredded by plastic bags • Eliminates problems equipment may windrow turners • May lose with plastic bags be needed for along with strength under which can in turn curb carts and contents reducing prolonged wet lower tip fee costs possibly bins pre-processing conditions, and processing site • Smaller bins have costs making handling • Sticker system can be limited capacity, • Allows airflow difficult used to allow especially for fall during collection • Non-degradable homeowners to use leaves process, items (such as their own container preventing pre- glass bottles, (supplemental kraft composting odors bricks, cans) bags could also be • Most models cannot be seen used) stand upright, through the making loading paper easier • Less potential for puncture or tear than plastic • May hold more material than plastic, which tears more easily

Michigan Compost Operator Training Guidebook 3-8 Collection Equipment Options

Different methods of material set-out Some collection vehicles may be specifically require different types of collection designed for handling particular materials. equipment. For material that is set-out For example, leaf vacuum trucks are often loose in the street, equipment is needed for used to collect leaves from the streets in gathering the material and loading it into a fall. Mobile chipping units are used to transport vehicle. Contained material may handle tree trimmings and other wood be loaded directly into a transport truck, wastes. such as an existing garbage truck, or a truck with an automated loading mechanism.

Following is a summary list of the various types of equipment used for the collection of yard trimmings. General gathering Material-specific Transport • Front-end loader • Leaf vacuum truck • Dump truck • Mechanical claw • Mobile chipping unit • Rear-loading packer truck truck for wood waste • Semi-automated rear- loading truck • Automated or semi- automated side-loading truck

Loose material is typically set in the street Material contained in bags can generally be for collection. If the material is a mix of manually loaded into packer trucks, but yard trimmings types, a front-end loader or carts are commonly too large for manual mechanical claw truck may be required to loading. Semi-automated rear-loading load the material into a transport truck. trucks or fully automated side-loading trucks Loose material such as brush may be set on are required to handle carts with capacities the curb, in which case it would be handled typically need for yard trimmings collection separately from material set in the street (i.e., 60 or more gallons). (e.g., leaves and grass).

Michigan Compost Operator Training Guidebook 3-9 General Gathering Equipment

Front-end loader Mechanical claw truck

For efficient yard trimmings collection, the The claw is a pincer loading bucket attached front-end loader is usually adapted with an to the front-end lift assembly of a tractor. It oversized bucket (i.e., greater than 4.5 cubic is used for grabbing loose yard trimmings in yards). It is particularly efficient for the street. As with the conventional front- collecting leaves where leaf fall is heavy. end loader, material is hoisted into a This type of operation typically involves one transport vehicle–commonly a rear packer loader operator, one or two laborers as or dump truck. rakers, and two or more dump trucks for transport. Advantages Disadvantages • Efficient for loose • As with front-end material collection – loader, relatively Advantages Disadvantages either leaves or only time-consuming mixed yard • Potential • Efficient for • Relatively time trimmings materials contamination collection of consuming • More adaptability to from street debris leaves • Potentially high different materials • Can interfere with • May utilize contamination and conditions than street parking existing • Dump trucks may conventional front- during collection municipal fill fast because end loader season equipment leaves are not • Material is compacted compacted to some • Not as thorough as extent, saving space vacuum truck for in the transport leaf collection vehicle

Material-Specific Equipment

Leaf vacuum trucks

Vacuum trucks are often used to clean gutters and storm drains. They also efficiently collect leaves that are set-out loose on the street. They work by sucking leaves into a shredder, then blowing them into a transport vehicle. In some cases,

Front-end loader with a bucket is an efficient tool. leaves are also compacted.

Michigan Compost Operator Training Guidebook 3-10 Advantages Disadvantages Advantages Disadvantages • Thorough • High operating • Efficient for • Extremely time collection of and maintenance collection of consuming when material costs woody materials used as a regular that may be collection • Faster than front- • Potentially high end loaders when contamination difficult to handle method using other High labor, leaves are dry • Relatively slow • methods operation and • Leaves can be operation Useful for maintenance compacted • Does not perform • well with wet Christmas tree costs leaves collection • High potential Processes material for operator • Requires several • laborers at the point of injury collection

• Chips may be Leaf loader marketed as mulch

A newer type of collection attachment called a leaf loader is pulled along behind a Transport Equipment truck, and picks up leaves with a five-foot- wide sweeper. Like vacuums, it reduces leaf volume through some shredding. Dump truck

Advantages Disadvantages This utility truck is typically part of municipal service vehicle fleets. It can serve many • Labor costs are • Must be used on functions, including the transport of yard less than a curbed-street trimmings gathered by front loaders or claw vacuum system • Potential for high • Shreds leaves as it contamination trucks. loads • Can be towed in a Advantages Disadvantages variety of positions • Relatively low cost • Does not compact • Creates less leaf transport vehicle material and has dust; eliminates option relatively low need for special • Useful for receiving capacity, so box on truck loose material transport is gathered with either relatively the front-end loader inefficient and Mobile chipper or the claw costly due to labor • May be used for involved Mobile chipping units are typically used by collection of • Must be covered to public works crews and private firms material contained prevent blowing involved in tree trimming. They are also in bags material back onto • Commonly part of street useful for collection of special materials existing municipal (e.g., Christmas trees). fleet of service vehicles; cost of vehicle may be shared with other public works

Michigan Compost Operator Training Guidebook 3-11 Rear-loading packer truck Advantages Disadvantages • Initial capital cost • Time-consuming This truck is commonly used to collect is substantial relative to fully- automated side- garbage, and generally ranges from 16 to 25 • Efficient collection of material loader cubic yard capacity. It is also efficient for contained in carts • More collecting yard trimmings materials in bags, • Fewer trucks and maintenance largely because it compacts the material. workers required than for non- compared to rear- automated loading/bag vehicles Advantages Disadvantages system • Reduces potential Efficient for a Not necessarily • • for operator injury system that uses workable as a bags for set-out transport vehicle material in a loose • May be used as material Automated side-loader transport vehicle in collection collection system system involving collection • May be This truck has a fully automated loading of loose material impractical mechanism. The mechanism grabs a with front-end where carts are container and hoists above a hopper into loader or claw used for set-out which the material is dropped for truck because of the compaction. The operator can stay in the • Compaction difficulty in minimizes hoisting large cab throughout the process. transport costs carts into packer • May take Advantages Disadvantages advantage of existing equipment • Efficient collection • Most expensive such as garbage of materials option collection vehicles contained in carts • More • Fewer trucks and maintenance workers required than for non- than for rear- automated Semi-automated rear-loading truck loading/bag vehicles system With this truck, an operator positions a cart • Less labor for a lifting mechanism (e.g., a bar lift) to required than for hoist into a hopper at the rear (with some semi-automated rear-loader models, on the side) of the truck. The • Reduces potential operation may require a crew of two, one for operator injury to drive the truck, the other to handle the container. Alternatively, one operator can perform the entire operation, but at a slower rate.

Michigan Compost Operator Training Guidebook 3-12

Use of Transfer Stations for Longer Distance Hauling to Processor

To reduce local collection costs and processing fees, some communities have opted to designate a transfer station for yard trimmings. This allows the smaller volume vehicle to travel a short distance to empty loads and go back to curb collection. Then up to 100 cubic yards of compacted material can be hauled by one driver to the composting Photo: A Syracuse University Physical Plant truck facility. Remote facilities may have lower dumps 4.45 tons of food waste on May 6, 2010 at the tipping fees due to being located in sparsely Onondaga County Resource Recovery Agency (OCRRA) populated areas. Amboy Compost Site in Camillus. http://greenuniversecity.syr.edu/UniversityFoodServices.htm

Food Waste

This section focuses on composting food waste or, more specifically, adding food waste to an already successful yard waste composting operation. Concepts covered include: assessing needed capacity; capabilities and the potential cost of adding food waste to operations; maintaining low odor operations; and characterizing, collecting and processing food waste. Practical tips are provided to achieve the best return on processing food waste.

Introduction Nationally we throw away more than one- Adding food waste to a composting operation quarter of all prepared food, approximately is an excellent way to increase the volume 96 billion pounds each year. Food waste and nutrient quality of the end product. As includes preparation waste and scraps, as such, it may also increase your customer well as uneaten food from households, base, contributing positively to the bottom commercial, institutions (i.e. school line. However, the added expense of cafeterias), and industrial sources such as additional processing and the higher potential food processors. According to the MRC’s for odor incidents may prevent one from Recycling Measurement Project Report of taking that step. 2001, organic waste made up approximately 29% of Michigan’s municipal waste stream in Food waste comprises the single largest 1999 with 163 compost sites managing only component of the waste stream by weight. about 10% of that waste.

Michigan Compost Operator Training Guidebook 3-13 Characterizing Food Waste Food waste differs from yard waste in that it conditions, demands that food waste be is generally characterized as a highly collected and processed in a timely and putrescent, rapidly degradable feedstock with efficient manner. a high moisture content and bulk density. A California case study characterized food Pre-consumer food waste -- or the vegetative waste as generally scraps resulting from food production -- is composed of 71% fruit and easily separated from vegetable waste, 26% packaging and service bread and starch waste, Adding food waste to waste; thus, it usually does and 3% other items. existing composting not present the operations increases the contamination issues that Compostable Food volume and quality of the post-consumer food waste Material capture does. Newcomers end product. to food waste utilization Food waste that can be often initiate a program composted includes, but is with pre-consumer food waste, leading to a not limited to: higher rate of program success.

• trim from fruits and vegetables, Post-consumer or uneaten food waste is spoiled fruits and vegetables, salads often contaminated with paper, metal, glass, • day old breads and pastries, excess and/or plastic food packaging, which batter, spoiled bakery products complicates the composting process and • dairy products - cheese, yogurt, ice decreases the value of the resulting compost. cream, and miscellaneous by-products However, these problems can be resolved • floral waste and trimmings, plants successfully, as demonstrated below. • leftover food that cannot be served again The inclusion of soiled paper products in food • frozen foods waste composting is common, and may solve • coffee grounds and filters a variety of composting and recycling • tea bags challenges. Paper adds a necessary carbon • egg shells and cartons source to the composting mix, and will absorb • seafood (including shells) much excess moisture. • consumable liquids (beer, wine, liquor, juices, soda, vinegar, etc.) Most paper products can be safely and beneficially used as a composting feedstock • meat processing by-products when the paper or cardboard is soiled or wax- • plate scrapings and leftovers, post- consumer food waste coated, or where markets for traditional paper recycling are not available or The potential of food waste to produce liquid economical. Composting economics and leachate, combined with its low carbon-to- diversion from disposal are improved by nitrogen ratio relative to ideal composting including non-recyclable and soiled paper

Michigan Compost Operator Training Guidebook 3-14 with the food scraps. Keep in mind that all through common paper recycling channels. paper categories contain very low levels of Composting wax-coated cardboard is, potential contaminants, though in most cases therefore, an attractive option for both these levels are below those found in yard generators and composters, though it may trimmings and background soil levels. require specialized equipment to shred the cardboard to reduce particle size.

Non-Vegetative Food Waste Food waste, especially post-consumer waste, may contain meat, dairy, grease, fats, oils and other non-vegetative organics, some of which are prohibited by composting facilities. Although they are organic and degradable, they break down slowly and composting them requires more time, care and supervision because they can contain more pathogens than other compostable items and may attract animals and insects. Local renderers or meat processing by-product specific composters may be a good option for managing significant or concentrated quantities of animal by-products.

Compost operations utilizing meat processing Compostable paper waste mixed with food waste. by-products and/or animal bedding can be Paper will absorb liquid inside collection successfully managed through a variety of containers, reducing spills and seepage from techniques, such as utilizing a concrete pad compactors and collection trucks. In the and bunkers or in-vessel composting units compost pile paper acts as a bulking agent, with full containment of leachate and run-off, improving aeration and reducing compaction. also employing adequate cover for odor Waxed-coated corrugated cardboard and control (i.e.: sawdust, woodchips or leaves). paperboard is abundant in the food Alternatively, another option for non- preparation industry, and cannot be recycled vegetative organics is anaerobic digestion for methane recovery.

Working with Generators Conducting a waste audit is important to the waste audit is likely to reveal that the success of any waste reduction program; heaviest component of most waste streams in knowing how much food waste is generated grocery stores, restaurants and cafeterias is by the operation on a daily basis is the key to food waste, and the greatest volume designing an effective management system. A

Michigan Compost Operator Training Guidebook 3-15 component of that same waste stream is management of food waste for utilization is a cardboard. key component to a successful program.

According to the EPA, the organic waste in Food scraps are separated from other wastes supermarkets makes up 75-90% of the entire at the source of generation -- for example, in waste stream, and in schools and restaurants food preparation areas -- then collected 74%. A study compiled by Draper and Lennon frequently and routinely. Kitchen and wait Associates estimated the following staff, and possibly customers (if plate generation rates: schools 0.35 lbs/meal; scrapings are collected) must be taught to health care 0.6 lbs/meal; prisons 1 separate acceptable materials for lb/inmate/day, conferences 0.6 lbs/meal and composting. The selection of food waste supermarkets 3,000 collection containers lbs/employee/year. should be coordinated with U.S. supermarkets solid the waste hauler. Normally, collection costs waste streams are 75 – are billed by the cubic yard What eventually (a volume measurement); 90% organic waste. determines whether a therefore, food waste business undertakes a food measurements must be waste diversion program is converted. Volume-to-weight conversions for if the benefits outweigh the cost. To help food waste vary considerably, depending on make that determination, the following five the type of food and its moisture content. If factors need to be considered. trash collected is measured and billed by weight, a standard container filled with 1. Waste Management Costs representative samples of the institution’s food waste should be filled then weighed for Diverting food waste to a composting an approximate conversion between volume program requires a separate collection and and weight. transportation system, one that operates in parallel with a waste management system. Standard container sizes and their volume Remaining trash will continue to go to the capacity include (202 gallons = 1 cubic yard): landfill, while food waste will go to a compost 5-gallon container - .025 cubic yards site. As food waste is removed from the 32-gallon container - .16 cubic yards landfill waste stream, the need for frequent trash pickup is reduced, as may be the need 64-gallon container - .32 cubic yards for a large trash holding container. Like 96-gallon container - .48 cubic yards landfills, compost operations charge a tip fee, but usually at a rate equal to or lower than

landfills. To avoid odor and health and safety Another consideration is the seasonality of concerns, inform your local health composting sites. Some municipal programs department of your program to eliminate cease collection of residential and downtown misinformation. Educating employees that yard waste during the winter months, so would be responsible for separation and working with residents to give them home-

Michigan Compost Operator Training Guidebook 3-16 based alternatives for food waste you need to check with your composter to management during the winter months make sure the compostable products are becomes important. For commercial and acceptable in their operation (i.e. may require institutional establishments, finding a hauler the feedstock to be shred prior to that can continue collection year round so composting). that kitchen staff operations remain constant is key to a successful program. Keeping things simple at first allows one to establish a successful collection system more Accommodating changes to your current easily. Continuous employee education, waste handling system means renegotiating getting employees to “buy into the system,” the contract with your current waste hauler and monitoring will help, as will color coded or finding a new waste hauler that can bins and appropriate labeling and signage. provide the variety of services you now Once employees are trained, minimal extra require. Understanding your service needs time is required to separate materials as it will allow you to design a program that works. becomes part of the normal daily routine.

In order to make an informed decision It’s important to know how much food waste regarding services, it is important to become is generated by the operation on a daily basis. familiar with the waste management facilities A way to estimate the amount of waste and associated management costs in your generated is to measure all of the scraps vicinity. produced in each area during a typical operation day or week, and then project this 2. Food Waste Separation and amount over time. For example, if you have Collection several stores or cafeterias measure one typical container of food scraps and then In general, pre-consumer food scraps are multiply this amount by the number of more easily collected and composted because containers collected. Of course, make sure it is fairly simple to train food preparation that employees are informed, and that employees to properly separate compostable containers contain food scraps only. food scraps from other non-organic waste. Post-consumer food waste diversion will 3. Storage and Collection Containers require regular monitoring by trained staff, as well as training of consumers to reduce the The selection of outside collection containers level of contamination in collected food should be coordinated with the food waste waste, which can decrease the value of the hauler. (In some cases, the hauler may food waste to compost operators. Up-front provide these.) Existing containers can simply involvement with your procurement be re-labeled, or it may be determined that department and suppliers to provide only the number or size of containers needs to be compostable products will ease the post- changed. Collection containers will require consumer food scrap contamination regular cleaning even if food waste is concerns, as would switching to reusable contained in bags. trays, plates and silverware. But, the costs and benefits of these types of operational The collection system is critical to a food program changes need to be considered and waste utilization program. The system for

Michigan Compost Operator Training Guidebook 3-17 separating food waste at the source and be used by generators at workstations to transporting the materials to a vehicle collect materials, and then be rolled to a pick- collection point should be as simple and up area when full. These totes must be convenient as possible. rinsed out and cleaned frequently.

The primary objectives of the collection It is important to ensure that the hauling system are to: vehicle is equipped with leak-proof seals and seams that are inspected often. Food waste • Maximize the capture rate of food that is collected in biodegradable and waste compostable bags may reduce the frequency • Eliminate non-organic contaminants of cleaning collection containers. such as plastic wraps, rubber bands, glass, and metal The cost to change the number or size of • Minimize labor and space outside and inside collection containers is requirements. usually a one-time expense; simply add as few containers as possible when beginning. Collection bins should be placed in a Clearly marked and brightly colored convenient area for staff and/or customers to containers -- such as green for food, blue for use. Due to the high moisture content of food recyclables, and brown for trash -- are helpful scraps, containers should be a reasonable size for proper participation and reducing for employees to lift and load into a central contamination. collection container or on-site composter. Containers should only be filled to 2/3 4. Collection Frequency capacity to reduce spillage. Just as trash hauling needs to be prompt and Whether collected in buckets or small, reliable in order to avoid health and safety biodegradable bags, the collections will be problems, so too does food waste hauling. accumulated in a larger, centralized tote or Some institutional generators of food waste small dumpster. If possible, combining food have found it easier and more economical to waste with yard clippings and leaves in a cart transport collected food waste themselves. or dumpster will reduce potential odor and Others contract with private waste haulers to leakage concerns. Haulers can pick-up the collect and deliver the materials to a food waste in bulk, using roll-off containers, composting site. compactors, or specialized vehicles for high volume generators; or they can dump full 32- The collection of food waste should occur 64 gallon totes and dumpsters from small frequently, and upon arrival at the generators with automated collection composting site, the material should be vehicles. immediately mixed and incorporated with the other materials on site. Containers collecting food waste will require regular cleaning. One collection option is for Collection and hauling schedules and routines the hauler to swap clean empty totes with full are dependent upon the amount of food totes; this means that totes will be tipped and waste collected at the site of generation. cleaned at the composting site. The totes can Changes in collection frequency necessary to

Michigan Compost Operator Training Guidebook 3-18 manage food waste will result in fluctuations plants that have anaerobic digestion system in “disposal” costs. Once a successful pattern that need the high biological oxygen demand is established, fluctuations will give way to a (BOD) to break down the phosphorus, it is a predictable new reality. growing concern.

5. Other Considerations Reducing the discharge that goes into a garbage disposal by diverting that material Worker Training for composting is likely to save water costs, save possible BOD and TSS (total suspended There are minor costs associated with solids) surcharges, and avert potential training workers to separate compostable restrictions on disposal into the sewage food waste. While a few compost site system. Check with the local sewage operators provide this service, many do not. treatment plant to find out whether the BOD Be sure to figure training time into your levels resulting from using garbage disposals cost/benefit estimates. If the business is needed in the treatment process, before decides to take on post-consumer food waste deciding on the best organic management utilization, training may have to include practice for your area. consumers and will require more rigorous oversight overall. Household Organics Collection

Many communities and private businesses around Michigan already provide for the curbside collection of yard waste, grass, leaves and brush. Adding household organics to that service is relatively easy. Including food waste with yard waste collection makes for a less messy, less wet transfer process than collecting food waste on its own.

The overall volume of organics to be processed will increase, as may the need for blending before piling. But the primary challenge for the curbside collection of other household organics is education. Helping Employee and worker training requires oversight and continuous training of new employees. householders understand the composting process and in some cases providing the

necessary collection containers will make curbside collection of food waste a viable A common practice in food service businesses community option. is to put food waste into the garbage disposal, which then sends the organics into the sewage system. While this may be acceptable in some areas of the country or in biological-based sewage treatment plants or

Michigan Compost Operator Training Guidebook 3-19 Working with Haulers While transporting food waste to an off-site maximize collection efficiencies. When done composting operation may be the simplest properly, problems are prevented and solution for most commercial enterprises, transportation costs are kept to a minimum. finding a hauler with the interest, ability and commitment is often the weakest link in the Restaurants, grocery stores, and cafeterias in chain of food waste composting. The unique close geographic proximity might consider properties of separated food waste require entering into a cooperative agreement with a specialized handling to maintain a waste hauler to assure the success of a food contaminant-free and manageable material. waste collection program. Separating food Regular and more frequent collection will waste for utilization from other types of keep odors and pests to a minimum. Food waste headed for the landfill means that waste hauling, however, also offers new waste management costs are diversified. opportunities to increase and expand a Haulers are taking waste to the landfill, and collection business. the generator is paying for transportation and landfill tipping fees. Hauling separated food Hauling Food Waste Efficiently waste to a composting operation means that generators will pay for transportation and Waste haulers maximize their profit by compost tipping fees. Traditional waste optimizing vehicle capacity and collection disposal fees will be offset by the diversion of frequency. If the vehicle is too small, food waste to a composting operation. Often excessive transportation costs may result the cost to compost is less than the cost to from traveling to the compost facility too landfill, but this depends on the facilities, often. Conversely, small loads in a large services and tip fees available in your area. vehicle may not warrant use of the equipment. The goal for the waste hauler is Change in waste disposal and hauling services to match food waste generation with typically requires a change in service collection frequency and the appropriately- contracts. Likewise, the change in waste sized vehicle. management and collection routines may necessitate contract negotiation between the The type of collection vehicle can vary from parties involved, as well as education of the front- or rear-load compacting trucks for employees. dumpsters, automated side-loader for totes, sometimes split compartments if co-collected Compost operators should also consider with recyclables or trash, or even trucks other transportation options. Allowing equipped with continuous feed mobile mixing generators to haul their own food waste to units. the operation might reduce costs and simplify the process. Compost operators may want to Generators may be required to produce a consider adding food waste hauling services minimum amount of food waste in order to to a composting operation, if the proximity to participate in a collection program to the organic source is economically feasible.

Michigan Compost Operator Training Guidebook 3-20 MICHIGAN COMPOST OPERATOR TRAINING GUIDEBOOK Best Management Practices for Composting

Part 2: Site Design & Operations

Michigan Recycling Coalition PO Box 10070 Lansing, MI 48901 Phone: 517-974-3672 [email protected]

Best Management Practices for Composting

Facility Siting and Site Design

4 Introduction

The rapidly growing popularity of composting as a low-cost, community-based solid waste Site Planning p. 2 management technique can strain the Odor and Site Design p. 3 existing compost infrastructure. These overburdened facilities are susceptible to Site Capacity and Sizing p. 5 odor production and excessive processing Site Layout p. 7 costs that can lead to program failure. Area Requirements p. 8 These challenges tend to feed off of one Site Selection p. 10 another. Odor problems lead to increased Site Design p. 11 processing costs, which in turn increase the need to process greater quantities of yard Drainage Design Information p. 14 waste in order to generate higher Design Checklists p. 17 revenues. The cycle can continue until the facility becomes legally or economically Example Compost Pad Design p. 20 infeasible to operate. The cycle can be Overview of New Composting p. 21 broken, however, because both of these Law failures can be prevented in large part through the application of good basic site design principles.

This portion of the Compost Operator Training manual describes best management practices for site-related issues associated with intensive windrow composting, where the entire site must be accessed more than three to five times weekly.

Michigan Compost Operator Training Guidebook 4-1 Site Planning

A compost site must provide sufficient area Michigan PA 451, Part 115 (formerly P.A. 641) and conditions for all-weather composting governs the composting of non-exempt while limiting environmental risk, odor, and organic waste materials (exempt materials noise. Site development involves creating a include leaves, grass clippings, garden waste, plan for finding an acceptable location, and brush/wood chips and up to 5% by adapting the composting method to the site volume Class 1 organics such as food scraps, (or vice versa), providing sufficient land area paper, food processing residual). Many local for operations, and implementing surface units of government require compost sites to runoff and pollution control measures as adhere to specific zoning and land use needed. regulations that regulate where composting can take place. All building requirements, To help understand geographic and other surface and ground water regulations, and impacts on site planning, operators should federally based NPDES requirements should make a preliminary sketch of the facility also be investigated. The DEQ’s Water showing all key areas and factors which will Resource Division has created a compliance affect operations, including: assistance document entitled "Compost Wastewater & Storm Water Permit • prevailing wind direction Information - Compliance Assistance for Yard • traffic flow patterns Clippings Composting Facilities". This • land slope document describes the applicable permits • runoff patterns related to wastewater and storm water • surrounding land uses discharges from compost facilities. The • wetlands or water bodies document can be found at • activity configuration (materials www.michigan.gov/deqstormwater (select handling and processing) Industrial Program, then under Storm Water Program Compliance Assistance select Permitting & Regulation Compost Operations Compliance Assistance.) Before beginning the planning process, it’s important to understand local and state NOTE: SEE APPENDIX AT THE END regulatory requirements including permit applications that may affect the site OF THE CHAPTER FOR AN operation. Also be aware that starting a OVERVIEW OF CURRENT STATE composting facility will raise concerns among LAWS ABOUT REGISTERING YOUR neighbors and local public officials. Educating these groups about composting and its COMPOST FACILITY, AND STATE advantages will be a critical part of getting OPERATION REGULATIONS. started smoothly.

Michigan Compost Operator Training Guidebook 4-2 This training manual focuses on large scale processing residuals, etc.), an enclosed in- yard clippings composting with the option to vessel system or outdoor operation that has a add up to 5% by volume ‘other’ (Class 1 lined pad or groundwater discharge permit is according to the MDNRE) organics. When required to control all water runoff and planning to compost more than 5% by volume groundwater. Class 1 organics (food scraps, paper, food

Odor and Site Design . And, proximity to neighbors requires high Factors that affect odor operational standards to avoid problem- causing odors and traffic issues. Resolving Many factors affect the potential for odor these conflicts is key to acquiring and buildup during production at a compost developing a compost site that successfully facility, including: economics, site location, balances the conflicting needs of cost versus weather, community and markets. These quality. must be balanced with care in order to develop a successful composting facility with A variety of odors, particularly those caused adequate equipment, personnel as needed, by anaerobic conditions, are attributable to and a system to move the pressures caused by the product out the door. need to intensively process high volumes of organic A successful compost site Budgets frequently dictate yard waste material at that yard waste be design balances the inappropriately sized sites. managed using relatively conflicting needs of cost Physical topography such low-tech windrow type versus quality. as puddles, mud, and acidic management conditions also contribute techniques. Yard waste to the development of generation patterns often require that anaerobic processes but are preventable with composting be carried out amidst dense good engineering and site design. populations to reduce transportation costs. However, large parcels of land are difficult to The relationship of odor to site find and costly in suburban communities design where yard and garden clippings generation is Odor minimization is a major objective of at it’s highest. These sites can be too small facility siting and design. Successful site with little room to expand because of design isn’t conceptually difficult; it simply proximity to neighbors. Increasing the requires the control of water and runoff on quantity of incoming materials makes these the operating surface of the facility. sites more crowded and inefficient.

Michigan Compost Operator Training Guidebook 4-3 While good site design alone cannot ensure Odors can result from several pile that operations will produce few odors, poor environment factors, for example ammonias site design is almost certain to cause odor and sulfides (rotten egg smell), are associated during production at all but the lowest with excess moisture during aerobic volume sites. Site design should be the first composting; amines (fishy smell) are component employed to minimize the associated with anaerobic conditions; and opportunity for odor production. volatile fatty acids (VFA), are associated with anaerobic conditions; evidence of unstable The existing moisture content of a process. composting mass, rainwater inputs, and runoff are all important factors that must be Byproducts of anaerobic respiration tend to actively managed. The operating surface be acidic. If the composting mass becomes must be prepared in a manner that limits the acidic, metals and other elements present in amount of water that is held on the pad. This the material may leach and become includes grading, sloping and hardening of the concentrated in site runoff. Leachate is the pad surface. It is important that water drains liquid that has moved through the compost quickly, leaving the pad strong enough to pile and exits the bottom of the pile. The support heavy equipment despite several leachate contains dissolved and suspended days of rain. Runoff water, either from the pollutants. composting process or from rainfall, must be conveyed away from the operating surface Water management for odor and/or accumulated in a retention pond before reusing for irrigation or releasing off- Prevent pooling or ponding site. The use of vegetated bio-swales assists Ponding of water, particularly on the in filtering the runoff water before it enters a composting pad, will cause a number of detention or retention pond. operating problems. First and foremost, ponding can create anaerobic conditions and Anaerobic conditions generates odor. Pooling and ponding If compost piles are located in standing water weakens the composting surface. Standing for even short periods of time, air spaces puddles and ponds create saturated soft within the pile will be replaced with water. spots on the pad that become susceptible to Recall that when water replaces air in rutting and other physical deterioration that compost piles, there is no oxygen for eventually necessitates remedial care. respiration and aerobic microbes cannot survive. Anaerobic processes can be caused Initially, proper pad construction and sloping by water in piles, compaction or small should prevent pooling. A surface of rigid or particles, where aerobic microbes are semi-rigid pavement with gravel or slag replaced with anaerobic ones. Composting surfacing and an appropriate sub-base is still occurs, however, anaerobic respiration recommended. After construction, constant produces offensive odors. This can set off a pad maintenance and housekeeping activities series of problems, even when anaerobic are essential to preserve drainage and conditions are present in only localized downward slopes to convey all water away portions of a pile. from the compost. Windrows should be

Michigan Compost Operator Training Guidebook 4-4 placed along the “fall line” of the slope, and pose a significant odor and possible rather than across the slope, to ensure pollution risk. Optimally, it would be best to drainage of water away from windrows. As avoid the accumulation of moisture in the illustrated in the diagram of a sample site at first place. Where formation of anaerobic the end of the chapter. pools cannot be prevented, odor-causing elements can be reduced by adding Treat anaerobic pools pulverized limestone to the pool and If pools of leachate or water form on a surrounding area. composting pad, they can become anaerobic

Site Capacity and Sizing

An important step in site planning and generated each year. The following rule of development is calculating the capacity thumb should be considered an average needed based on projections for volumes of range, assuming leaves, grass and brush are incoming materials, equipment needs and collected: materials handling activities.

Lack of adequate space and equipment, Average residential 1-2 cubic yards per combined with overly large quantities of generation: household per year. incoming materials can cause dramatic odor and material management problems. Most Design key: Older communities with sites cannot efficiently handle more than larger trees may 5,000 cubic yards per acre per year generate more leaves; (cy/acre/yr) and 8,000 cy/acre/year is newer communities with generally the upper limit for an intensely large lawns will generate managed site. Too much material makes it more grass. difficult for operators to mix and turn material in proper ratios and frequencies. The following table identifies optimal High capacity approaches (e.g. more frequent volumes which can be processed annually mechanical turning and quicker organic based on low, medium and high intensity decomposition) allow more efficient use of processing means. This can be used as a rule sites. of thumb during the design process to understand that a medium and high intensity Estimating Generation site, more equipment and more labor will be needed to push the material through. It is An important planning step is identifying the important to note that the Michigan compost geographic area to be served by the site, and rules state a limitation of 5,000 CY per acre at estimating the volume of organic waste to be any one time (i.e. if you measure an acre at

Michigan Compost Operator Training Guidebook 4-5 any time during the year, the active, curing or finished compost volume on that acre cannot If you measure an acre exceed 5,000 CY). at any time during the year, Annual Throughput the active, curing or finished Annual Annual Annual compost volume on that acre Capacity Material Material Material cannot exceed Volume- Volume- Volume - 5,000 cubic yards. 1 Acre 5 Acres 20 Acres Low 3,000 CY 15,000 CY 60,000 CY Medium 5,000 CY 25,000 CY 100,000 CY High 8,000 CY 40,000 CY 160,000 CY Small overall volumes, Low intensity minimal operational attention

Speed up organic breakdown Medium through shredding, increased intensity turning to handle higher amounts per year; attention to C:N ratios, moisture content, aeration; engineered pad

Attention to C:N ratios, High intensity moisture content, aeration; Design Considerations – shared by all facilities high level of equipment and site development, including but generally require more attention as self-propelled windrow intensity increases. Any compost site should turners, shredders, have adequate drainage away from the piles screeners, loaders, and should consider staff operations training, engineered pad, aeration turning and incoming volume logs. systems, positive odor control, and +sophisticated instrumentation; extensive staff training

Michigan Compost Operator Training Guidebook 4-6 Site Layout

In acquiring or developing a compost site, the Material Flow and Site Configuration operator should plan to accommodate appropriate operating strategies, utilities, material handling areas and other factors.

Site Access Appropriate site entrances and exits are especially important in providing the facility with a good public image. Important Do’s and Don’ts include:

DO locate the site entrance on or near major transportation routes DON’T allow incoming and outgoing vehicles to travel on residential streets. DO clearly mark the site entrance with signs DON’T allow incoming vehicles to back-up off site while waiting to enter. DO provide enough space for trucks to adequately maneuver off the streets DON’T allow vehicles to track mud or Utilities compost from the site to public roads. Access to common utilities will be required by DO insure that entering and exiting vehicles compost facilities. Electricity, water, can safely enter and leave traffic. telephone, internet, and sanitary sewer (or septic tank and drain field) are basics that each site will require for successful operation. Access to water for moisture conditioning the composting mass is particularly critical when conditions and materials are particularly dry and susceptible to combustion.

Compost facilities carry out three types of operational functions. 1) Receiving/Staging; 2) Processing; and 3) Curing/Storage. Space allocated to each of these activities can be calculated based on incoming volumes of

Michigan Compost Operator Training Guidebook 4-7 yard clippings and other organics on a visitors. Fencing around the facility monthly basis. perimeter, a locking gate, lighting, and utilities help protect the facility from those Site Security troubles. Good signs promote efficient site Access should be controlled to limit liability use by visitors, help to prevent confusion, and from illegal dumping, contamination, provide vital information in the case of vandalism, theft, and injury to wandering emergency.

Area Requirements

Efficient facility layout is important to Site Layout Objectives minimize the frequency and amount of material movement from station to station. 1. Minimize backtracking, system delays, Some overall layout objectives that each and material handling. facility designer should consider are: 2. Maintain flexibility. 3. Separate feedstock piles to allow Area Requirements precise combining of materials. Staging/ Processing Curing/ 4. Utilize manpower and space Receiving Storage efficiently. % of Total 20-30% 55-65% 10-20% 5. Provide for good housekeeping and Site Area (Assuming some ease of maintenance. Needed leaf storage in processing area)

Material Handling Needs % of incoming Staging/Receiving Requirements Processing Curing/Storage materials Requirements Requirements Accumulate in Fall for following Incorporate As finished compost Leaf Stream 50-60% Spring gradually with at 3:1 or 4:1 volume incoming grass reduction Accumulate for 1-2 days at most Incorporate quickly As finished compost Grass Clippings 30-40% with Fall leaves (See above) Accumulate until grinding can Grind separately As finished compost Brush/Wood chips 0-15% occur from grass or leaves (See above) Accumulate for 1-2 days at most Incorporate quickly Incorporate quickly Food Scraps 0-5% with Fall leaves with Fall leaves

Michigan Compost Operator Training Guidebook 4-8 Calculating Space for Active Compost The shape and size of windrows vary equipment and building. Often, though, the depending on the type of turning equipment curing and finished compost is stored outside used. The aisle space needed between and the area and pads need to accommodate windrows is also impacted by equipment these volumes. selection.

To accurately calculate the footprint of the site which will be occupied by the active processing area, operators will need to estimate the peak volume of organic materials and how much can be placed into each windrow. For additional information on calculating the full range of windrow types, the On Farm Composting Handbook is an excellent reference.

Where more sophisticated indoor or in-vessel There is plenty of space at Tuthill Farms for approaches are used, the area requirements composting. will be different to accommodate the

The table below provides some basic guidelines.

Calculating Windrow Volume Method and Approximate shape Avg. aisle Cross-sectional area equipment used width

Windrows/piles 11’ A = 2/3 x b x h turned with a bucket loader

Self-propelled and 5’ A = h x (b - h) * tractor-drawn windrow turners

* This formula is an approximation and is valid only when the width is greater than or equal to twice the height.

Michigan Compost Operator Training Guidebook 4-9 Site Selection

Location from neighbors. Buffers should take The process of composting will at times advantage of natural allies like prevailing generate odors. In order to ensure that winds, wooded areas, hills, and railroad cuts occasional odors are not a nuisance to the to cost effectively prevent offset impact. surrounding community, the site should be located away from nearby “sensitive receptors.” Usually, rural agricultural areas or those zoned for industrial operations are best Generally speaking, suited to outdoor composting technologies. Where more sophisticated operators become more indoor or in-vessel approaches are used, the challenged by the facility siting standards may be modified conditions of the site than somewhat. Proper attention during the design phase should minimize the the actual composting of disturbance that a facility brings to the the organics. surrounding community.

Setbacks, Buffers and Site Access Site Selection Criteria Setbacks from sensitive receptors and other • Proximity to customers factors should be observed whenever • Proximity to transportation corridors possible. • Minimum travel and materials handling • Firm surface to support vehicles under • 500-feet from a sensitive receptor (e.g. varying weather conditions hospitals, churches, schools, nursing • Opportunity for expansion homes) • Cost of space and utilities • 300-feet from residences • Buffer from neighbors • 500-feet from active wells • Drainage, runoff control • 200-feet from natural or artificial • Avoid sensitive receptors such as schools, wetlands hospitals, schools

• FAA regulations prohibit the existence of compost facilities within 10,000 feet of Where setbacks of this nature are not any airport. feasible, buffers should be constructed to mitigate the effects of compost facility impact. Composting facilities set near areas zoned for either agriculture or industrial purposes are Buffers can include constructed berms the best locations for siting a composting (**berm requirement from rules?), walls, and operation. rows of trees. They serve to block the effects of noise, odor, and visual impacts of the site

Michigan Compost Operator Training Guidebook 4-10 Site Design Although a firm processing surface is properly built site. 1) The surface should necessary, it does not have to be provide adequate stability and firmness for paved. Moderate to well-drained soils are year-round operational access with windrow satisfactory for some lower intensity yard turners, trucks, and other heavy equipment. waste composting situations. A pad This can be constructed in a variety of ways, constructed of 8 inches of compacted and as compacted gravel to concrete. 2) A pad graded sand or gravel works well when the should be constructed so that its final grade existing soil conditions are not acceptable. and elevation provide a slope that allows water to flow away quickly and efficiently Paved pads of concrete or asphalt are from the composting material. A 2% slope is generally a luxury and only a necessity for recommended as adequate. 3) The presence high-intensity sites. Pavement does reduce of clay at the surface of any site should “raise problems related to mud, equipment a red flag”, indicating the potential for wet operation, and pad maintenance. It also areas to form. Sites with clay soils will require minimizes the amount of stones that get special attention to preparation of hardened mixed into the compost. However, the cost is surface in order to avoid drainage and odor significant and pad runoff must be managed. problems.

Usually, an impermeable surface is required Successful development of these two design only when both the soil is well-drained and goals will result in a facility that dramatically the water table is high (w/in 4-5 increases operational efficiency and reduces feet). Concrete or asphalt is also sometimes the chance of odor and off-site leachate beneficial for special activity areas such as contamination. mixing of raw material with a bucket loader. Pad Surface Material and Design Sites without engineered pads on which to Several factors will influence the type of pad maneuver equipment have problems when material and surface preparation which may there are significant amounts of precipitation be required. These factors include the type of and the ground is soft. Equipment can get equipment to be used, the volume of material stuck in the mud, ruts may form and ponding expected, and type of soils present. may occur which can result in anaerobic conditions if a pile or windrow is located in the standing water. Generally speaking, Pad Type Design Keys operators become more challenged by the Rigid Pavement • Strip topsoil and add conditions of the site than the actual appropriate base and sub base composting of the organics. And these material challenges frequently lead to an • Design pavement cross-sections unsustainable business operation. for refuse packer truck axle weights fully loaded with yard clippings There are three key elements for site surface design that must be considered for any

Michigan Compost Operator Training Guidebook 4-11 Prepared Earth • Strip and compact ground inadvertent mixing with the compost Surface surface as underlayment product, erosion, high-temperature • Add 8-inch layer of compacted composting process, and the scraping action gravel or slag surface layer (4- inch lifts); an additional layer of of metal buckets regularly clearing the pad permeable sand may be surface to maintain open drainage required as the final base layer ways. Paving also allows for easier snow to promote drainage under the removal for year around activity. entire pad structure where clay soils are present Prospective operators should carefully • Use geotextile fabric between base layers and the underlying evaluate the operational benefits of paving all in situ soil where underlying or part of their site. At a minimum, the wet clays are present. mixing area and compost pad that houses working windrows should be hard surfaced. Typical Site Preparation and Construction Costs* Advantages of Prepared Surface

Average Cost Easier year-round access during all Pad Type per acre • Earth Pad (no fill) $7,000 – 10,000 climatic conditions. Gravel/Slag $30,00 – 50,000 • Reduced maintenance Asphalt Pad $65,000 – 100,000 • More efficient material handling Concrete Pad $150,000 and up • Reduces the likelihood of odor problems

*Does not include engineering and construction Disadvantages of Prepared Surfaces supervision; note that an economy of scale may be achieved with larger sites, thus reducing the average cost per acre. Cost figures may vary from community • The quality of finished compost can be to community. Facility operators can reduce these adversely affected when gravel or slag average construction costs by seeking cooperative materials become mixed in the organic working relationships with local contractors. mixture. Note that the significant additional capital • High maintenance costs of placing asphalt or concrete pavement • Excess water may be more difficult to are offset by the operational savings in facility control during rainy periods maintenance and other efficiency gains. • Soft muddy pads can mean down time during inclement weather Advantages of paved sites Where the water table is low and the soils are Paving your compost pad can alleviate sandy, less design effort and construction product management issues. Constant expense will be required to ensure access. In grading and re-grading is not needed to circumstances where the existing ground is maintain an appropriate slope and surface clayey and wet, greater effort and expense integrity. Water runoff can be controlled will be required to ensure all-weather more easily. The annual addition of layers of access. In any case, compost facility developers should give pad design and replacement surfacing material will not be construction the highest possible priority. required to make up for losses due to

Michigan Compost Operator Training Guidebook 4-12 Alternative Surfacing Options Under no circumstances should any Some operators have had success using centralized composting facility be sited on a alternative surfacing material like slag or ground surface area that has a clay base limestone that can be less expensive than without surface improvements. more common construction materials. Other Cohesive soils like clay cannot support activity operators with access to heavy equipment in wet weather. Statewide experience has have been able to prepare excellent “do it clearly indicated that sites located on a clay yourself” facilities as part of ongoing base without overlying pavement will become construction or landfill management inaccessible and extremely muddy after only activities. Clearly those composters with a month or two of steady operation. involvement or background in earthmoving contracting or landfilling are at an advantage In the limited circumstances where a pad of when it comes to constructing a less compacted native soil is feasible, the actual expensive compost site. pad and other high traffic areas (e.g. entry, exit, access roads, and perimeter areas Use of Existing Soils around grinders, debaggers and screeners) Under limited circumstances, compost sites should be carefully prepared in the same can be developed using existing soil manner that the foundation preparation is units. This approach should be considered carried out before placement of a gravel or only after carefully evaluating the proposed paved surface. These steps are: operation and the native soils for appropriate characteristics. 1) Clear proposed pad area of all vegetation and manmade structures. This type of lower strength pad surface is feasible where the proposed operation is to 2) Remove organic soil layer from be low intensity (e.g. infrequent use of proposed pad area. wheeled loaders for material management and turning). It should only be employed 3) Grade and compact (with vibratory when the surface geological unit is sandy or compaction device) suitable in situ gravelly materials. Additionally, the year granular soil for use as pad surface. around water table should be at least five feet below the surface of the proposed pad area.

Michigan Compost Operator Training Guidebook 4-13 Site Drainage Information

Pad Surface Slope important at composting facilities. It is Any outdoor surface for composting requires critical that each operation is designed, a slope that is suitable for the quick and constructed, and managed by knowledgeable efficient outflow of leachate and stormwater professionals in a manner that limits the runoff. Pad surface slope is critical to keeping production of compost wastewater and the site accessible in all weather. prevents the contamination of storm water. Site design and management should focus on In circumstances where non-rigid materials identifying areas of the site where compost (e.g. gravel, slag) are used, continual wastewater is potentially generated and regrading of the pad is required. Trucks, areas of the site where compost wastewater windrow turners, loaders and other heavy is not generated. Controls will need to be equipment leave ruts when operating on a implemented in both areas to adequately non-rigid surface, especially during wet protect groundwater and surface waters, periods of the year. In order to simply and however storm water runoff controls will be easily keep up with site “housekeeping,” the main focus in the areas where compost regrading of the site should occur every wastewater is not generated. day. Slopes of less than 2% are difficult to Compost Wastewater Drainage maintain, especially when most regrading is undertaken and completed using instruments Compost wastewater is a liquid that is no more sophisticated than the equipment comprised of process water; wash water; operator’s eyes. The overall slope of the pad, and/or leachate that ponds, flows laterally regardless of the material used in its from the base of the compost pile, or collects construction, should be able to consistently in an under-drainage system. Storm water maintain flow in the direction of the drainage that has been allowed to comingle with collection ditches. compost wastewater, as defined, is considered compost wastewater.

Design Keys Compost wastewater discharges from Rigid and durable Minimum slope of 1% composting facilities are highly variable and pavements: in one direction. can contain potentially significant levels of Gravel, slag or other Gradient of 2% in at nutrients, heavy metals, oil and grease, non-rigid surfaces: least one dimension soluble salts, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), tannins and phenols from decomposing Compost Wastewater and Storm leaves, herbicides, pesticides, fungicides and fecal coliform. The negative impacts to Water Drainage waters of the state from improperly managed Appropriate management of compost compost wastewater include, but are not wastewater and storm water is very limited to, the following:

Michigan Compost Operator Training Guidebook 4-14

• Elevated levels of BOD and COD Compost wastewater generated at the site cause oxygen depletion in surface may be collected in a properly lined basin and water, which could lead to fish reintroduced onto the compost piles. It may and aquatic organism mortality. not be discharged onto the ground or into Additionally, high BOD and COD surface waters without a permit from the loads can cause oxygen depletion Department of Environmental Quality (DEQ), in the soil column, which can Water Resources Division (WRD). result in the release and mobilization of metals in the groundwater. Any discharges of compost • High levels of nutrient loads wastewater to waters of the (mainly phosphorus) to surface state would require a waters stimulates excessive National Pollution Discharge growth of aquatic vegetation and algae causing accelerated Elimination System (NPDES) eutrophication of waterbodies. permit. High levels of nutrients, such as nitrates, are also a human Storm Water Drainage health concern in the

groundwater. In addition to managing and minimizing • Tannins and lignins are compost wastewater, compost sites should natural dissolved organic prevent the contamination of the storm acids derived from woody water that has not contacted production materials that give yard areas (feedstock, raw materials, compost clippings compost piles, etc.). It is critical that storm water from wastewater a tea color. non-production areas of the site is diverted • Discharges of compost away from production areas. Remember that wastewater can negatively when storm water mixes with compost impact the natural color of wastewater, the entire mixture is considered waterbodies, which can in compost wastewater. turn negatively impact the natural ecological processes Compost facilities need to manage storm within those waterbodies. water discharges from the site so that it does • Elevated levels of fecal coliform in the not cause negative impact to the receiving discharge is a human health concern. waters. Even with proper construction and management, storm water at the site may Ideally controls should be implemented on still carry some pollutants which can be site to prevent the generation of compost harmful to surface waters. If compost wastewater. However, if wastewater is facilities discharge storm water to the surface generated then it should be managed so that waters of the state or to a separate storm it does not comingling with storm water and sewer system a NPDES industrial storm water it does not discharge to waters of the state. permit will be needed. Storm water

Michigan Compost Operator Training Guidebook 4-15 management at compost facilities will involve Conclusion the implementation of a number of storm Composting plays a major role in both waste water runoff controls such as: management and resource recycling for our • Detention and retention ponds organic wastes. However, studies have • Diversion berms and dikes demonstrated that water quality degradation • Storm sewer inlet protection is likely if the process is not carried out in a • Vegetative filter strips professional manner on sites that are • Check dams appropriately designed, constructed, and • Infiltration trenches managed.

All storm water runoff controls utilized on site Outdoor compost facilities require a drainage require design by a qualified professional and system that will appropriately manage ongoing maintenance to be effective. The compost wastewater (if generated) and storm MDEQ Nonpoint Source Best Management water runoff. Compost wastewater if Practices Manual should be referenced to generated should be managed so it does not appropriately implement controls that will comingle with storm water runoff. All work effectively given specific site discharges of compost wastewater and storm characteristics. water generated onsite needs to be covered by all applicable WRD discharge permits. It is advisable that compost facility operators work with DEQ, WRD staff when considering how to effectively design site drainage and to appropriately permit compost wastewater and storm water discharges to waters of the state.

Michigan Compost Operator Training Guidebook 4-16

Compost Facility Planning, Siting, and Design Criteria Checklist

A. Materials to be Composted Yard Waste Yard Waste and other compostable materials (classified as Class 1 compostable material) such as wood, organic garbage, paper products and manures not generated in the production of livestock or poultry, spent grain from breweries, sugar beet limes, drywall, and dead animals not managed under dead animals act B. Compost Facility Planning Check Zoning Identify public officials with jurisdiction over the proposed compost facility Review local composting regulations Check meteorological parameters (e.g. wind direction) Identify critical surface and ground water resources Identify “sensitive receptors” Detail existing buffers (woods, roads, walls, hills. lakes, etc.) between site and its neighbors Identify possible areas for future facility expansion Detail surrounding transportation routes Identify project team (e.g. engineer, lawyer, contractor, equipment vendors)

C. Compost Facility Site Design Phase Acquire all necessary permits (building, zoning, business, and solid waste management) Prepare a construction erosion control plan to mitigate loss of soil and impact to surrounding water resources Identify types, quantity and seasonal distribution of incoming material Define incoming quantity limitations based on site size and composting technology Define material staging and preparation requirements Identify outgoing quantities of finished material Define size reduction/mixing equipment Define turning and aeration equipment Define screening and blending equipment Define utility equipment (e.g. loaders, dozers, trucks)

Michigan Compost Operator Training Guidebook 4-17 Define site boundaries Describe major areas of activities (e.g. receiving pre-processing, grinding, composting, curing) Describe major transportation routes to and from the facility Determine traffic flow on site (maintain counter clockwise flow is possible) Define buffers necessary to mitigate effects on neighbors Design pad and roadway surfaces Provide site security (e.g. gate, signage and fencing) Develop appropriate site erosion control structures Develop appropriate retention pond facilities for storm water control and primary effluent treatment (e.g. sedimentation) D. Yard Waste Only Site Criteria Not in a 100 year floodplain 50 feet from a property line DEQ minimum 200 feet from a residence, recommended 300 feet DEQ minimum 100 feet from a body of water, including a lake, stream, or wetland, recommended 200 feet 2000 feet from a type I or a type IIA water supply well 800 feet from a type IIB or type II water supply well 500 feet from a church or other house of worship, hospital, nursing home, licensed day care center, or school, other than a home school 4 feet above groundwater Pad surface material that allows year-round access and adequate support for expected loads (rigid or semi- rigid pavement; gravel or slag surfacing with subbase) Pad surface slope that allows for quick, efficient leachate outflow and storm water runoff (1% slope for rigid and durable pavements; 2% slope for gravel, slag, or non-rigid surfaces with daily regarding) Drainage conveyance structure that is capable of conveying leachate or storm water runoff to retention pond without overflow or percolation Diversion channels to direct runoff and promote sedimentation removal Stabilization of steep grades with geotextiles, vegetation, or rip-rap Retention pond at sites larger than 5 acres or those with high water tables Restrict/control rate of runoff to reduce quantity and increase quality of runoff

E. Class 1 Compost Site Criteria 50 feet from property line DEQ minimum 200 feet from a residence, recommended 300 feet

Michigan Compost Operator Training Guidebook 4-18 If within 500 feet of a residence, visual obstruction from a fence of at least 8 feet in height and 75% screening or an earthed berm that offers equal obstruction is required DEQ minimum 100 feet from a body of water, including a lake, stream, or wetland, recommended 200 feet 2000 feet from a type I or type IIa water supply well 800 feet from a type IIb or type III water supply well 500 feet from a church or other house of worship, hospital, nursing home, licensed day care center, or school, other than a home school 4 feet above groundwater If located within 10,000 feet of any airport runway used by turbojet aircraft or 5000 feet of an airport runway used by only piston-type aircraft the facility must be designed and operated so that the facility does not pose a bird hazard to aircraft Pad surface material that allows year-round access and adequate support for expected loads (rigid or semi- rigid pavement; gravel or slag surfacing with subbase) Pad surface slope that allows for quick, efficient leachate outflow and storm water runoff (1% slope for rigid and durable pavements; 2% slope for gravel, slag, or non-rigid surfaces with daily regarding) Drainage conveyance structure that is capable of conveying leachate or storm water runoff to retention pond without overflow or percolation Diversion channels to direct runoff and promote sedimentation removal Stabilization of steep grades with geotextiles, vegetation, or rip-rap Retention pond at sites larger than 5 acres or those with high water tables Restrict/control rate of runoff to reduce quantity and increase quality of runoff

Michigan Compost Operator Training Guidebook 4-19 Example of Compost Processing Area with Pad Detail

Michigan Compost Operator Training Guidebook 4-20 Overview of New Composting Law

Contact: Duane Roskoskey 517-582-3445 Agency: Environmental Quality

The law identifies several options for managing yard clippings: • Composted at the property where they came from. • Temporarily accumulated under specific conditions at a site before moving to another location. • Composted at a farm registered with the Department of Agriculture under specific conditions. • Composted at a composting facility registered with the DEQ Waste and Hazardous Materials Division. • Composted and used under specific conditions at a licensed solid waste landfill. • Composted at a processing plant meeting Part 115 requirements. • Composted at a site that has not more than 200 cubic yards of yard clippings if no nuisance is created. • Decomposed in a controlled manner using a closed container to create and maintain anaerobic conditions (e.g. anaerobic digester). • Disposed of at a landfill if diseased or infested or the material is an invasive plant collected through an eradication or control program and inappropriate to compost.

DEQ registered composting facilities will be subject to a $600 registration fee. The registration is for three years. Registered facilities have location restrictions and operating requirements, and are required to submit annual reports containing information about the amount of yard clippings and other compostable materials managed during the previous fiscal year.

DEQ registered composting facilities are subject to a $600 registration fee. The registration is for three years. Registered facilities have location restrictions and operating requirements, and are required to submit annual reports containing information about the amount of yard clippings and other compostable materials managed during the previous fiscal year. Questions may be directed to Mr. Duane Roskoskey at 517-582-3445 or by email at [email protected] .

www.michigan.gov/deq/0,1607,7-135-3312_4123-185537--,00.html

Michigan Compost Operator Training Guidebook 4-21

Best Management Practices for Composting

Operations

5

Introduction Incoming Material Stream p. 2 Composting is the art and science of Quantity of Incoming material p. 4 managing organic materials to provide an Pre-processing p. 7 optimum environment for the growth and reproduction of microbes. Experienced Compost Production p. 9 facility operators often compare composting Compost “Recipe” P 12 to making a fine wine, as a way of acknowledging that large scale compost Composting Process p. 13 production requires the balancing of complex interrelated factors. On the other hand, it is Staffing p. 20 neither “rocket science” nor alchemy. Field and laboratory research continues to provide Low Odor Operations p. 23 good scientific data on the process. While today’s operators also benefit from the Odor Control in Production p. 27 trial and error of earlier composting efforts,

there is no substitute for thorough planning, monitoring and analysis of operational data. Proper operation of a compost facility requires an established protocol for materials handling, and the right equipment and trained staff to carry out those procedures in a timely manner. Many factors are important in development of a successful composting facility. This module covers all facets of site operations, from material receiving through processing and monitoring. Principles of operation and recommendations presented herein are applicable to both large and small facilities. Building a pile Incoming Material Stream

Composters must continually monitor the odor problems and produce high quality incoming material stream in order to avoid compost.

Michigan Compost Operator Training Guidebook 5-1 Managing incoming materials Food Waste It is essential to evaluate the quality and Food waste differs from yard waste but is quantity of incoming organic materials in similar to grass in that it is generally order to operate a compost facility effectively characterized as a highly putrescent, rapidly without creating nuisance odor problems. degradable feedstock with a high moisture Important aspects of managing incoming content and bulk density. materials include: The potential of food waste to produce liquid • reduction of grass volumes and/or leachate, combined with its low carbon-to- addition of extra carbon material nitrogen ratio relative to ideal composting • paying immediate attention to grass and conditions, demands that food waste be food scraps as they enter the site collected and processed in a timely and • rejecting foreign materials or efficient manner, and may require chipping or contaminated material grinding if mixed with compostable products like forks, spoons and cups. Grass As grasscycling programs are becoming more Reducing the amount of grass in the waste popular, more volumes of food waste in the stream greatly reduces the potential for odor feedstock may be desirable. Food waste is generation. Grass collected in plastic bags high in nitrogen and speeds up the may be odorous even before it enters the decomposition process of compost. Adding facility. food waste to yard waste for composting will One way to reduce grass is through an reduce water needs throughout the process aggressive community education program. and increase the nutrient content of the The Southeast Oakland County Resource finished product. Once composted, food Recovery Authority (SOCRRA) demonstrated a wastes contribute to the overall beneficial 60% reduction in grass from its member characteristics of compost as a soil communities in the last four years through an amendment and nutrient additive. education program and financial incentives Brush (higher tip fees for grass). A key processing issue for Michigan composting facilities is whether to accept loads of brush commingled with grass and leaves, or only in separate loads. Depending upon the type of equipment used, grinding wet material such as grass can increase the rate of wear on cutting edges, resulting in costly maintenance and downtime. By accepting segregated brush at the gate, an operator can increase processing options and possibly reduce equipment costs. Brush alone can be stockpiled without causing odor, Food waste collection truck whereas commingled brush and grass cannot. The woody component of yard waste helps

the compost process in chipped form,

Michigan Compost Operator Training Guidebook 5-2 providing some carbon for microbes and Charging by weight effectively discourages enhancing aeration. Another disadvantage of this practice, although scales are costly. Signs separate collection programs for grass and of over-compaction include evidence that brush is the added cost for two trucks and moisture is being removed due to compaction extra employees. (streams of liquid draining from incoming vehicles) and obviously overloaded packer trucks (compressed springs and flattened Managing grass, food waste and brush tires). • Accept only enough grass to make the desirable C:N ratio, based on available leaves and brush. • If food waste is accepted, limit this volume to 5%, or to the amount accepted for your facility by the MDNRE, to manage C:N and moisture. • Give top priority to securing adequate leaf volume. • If accepting brush commingled with grass, invest in grinding equipment designed to handle wet materials.

Plastic bags Gate management Yard clippings collected and delivered in The condition of material arriving at a plastic bags present a major operational compost facility affects variables such as: concern for composters. Accepting grass • collection containers delivery in plastic causes foul odors, raises • type of delivery truck (degree of operational costs dramatically, and can compaction) reduce both the quality and value of the • amount of physical contaminants finished product (plastic bits, pH problems). • the length of time since grass has been Plastic bags cause odor problems because cut and in transport grass turns anaerobic and foul-smelling inside • curbside collection quality control the airtight container. Nitrogen-rich grass, Grass stored in plastic bags or a truck for especially with high moisture, begins to several days will be more odorous than in decompose soon after bagging, and uses up bulk or paper bags and delivered on the day oxygen. When placed in plastic bags, grass collected. can become anaerobic within hours. If a facility’s fee is based on volume rather than weight, haulers may compact more Debagging is costly, whether done material into each load to save money. This mechanically or by hand. To save money, densifies the feedstock and makes it more some operators build compost piles without difficult to aerate. Also, the site operator first debagging, and rely on a turner or loses money when the amount of material is grinder to shred the bags open. This system measured by volume rather than weight. relies on screening to remove plastic later

Michigan Compost Operator Training Guidebook 5-3 and often produces poor quality compost • Reject non-compostable wastes at the containing tiny pieces of plastic which blow gate. Track incoming loads so haulers can around the site. Compost with plastic in it be held accountable for trash. looks like trash and will be harder to sell. • Determine the maximum volume of grass and food waste your site can handle; divert to another site if this peak capacity Gate management tips point is exceeded. • Don’t accept material in plastic bags. If • Charge higher tip fees for grass and food you must, follow a rigorous and effective waste than for leaves and wood chips. debagging protocol.

Quantity of Incoming Material

Estimating incoming volume In designing a composting facility, decisions Seasonal generation and estimates must be made about the type The amount of yard waste generated varies and quantity of yard waste to handle. Site by season. Up to 60% of yard clippings in design and equipment depends on the Michigan consist of grass and weeds collected volume of material expected. Objectives for in the growing season from May through estimating volumes include: September. The overall amount of leaves • ensuring a sufficient supply of carbon-rich appears larger because it arrives in a shorter materials on-site to manage the C:N ratio time period than grass. Brush from pruning as windrows are built, and storm damage occurs primarily in two • sizing and equipping the facility for peak peaks in the spring and fall. Moderate volumes, and quantities of brush accumulate in the • planning effective operating procedures. summer and winter months. Food waste volumes in the spring may be high due to One approach to estimating yard waste is to households ‘storing’ food scraps in their multiply the number of homes by an average compost carts over the winter when yard yard waste generation rate. The following waste collection services weren’t provided. table shows data from Illinois. Food scrap volumes may also be higher in the summer and fall when local, fresh food are Table 1: Yard Waste Generation Rates per Single prepared. Family Household per Year Material Pounds Cubic Yards Loose Changes in weather, landscape practices and Leaves 160 0.8 population can alter yard waste volumes from Grass 1,040 2.6 year to year. To successfully handle Brush 300 1.0 fluctuations, a site must be sized to Total 1,500 4.4 accommodate estimated peak capacity.

Michigan Compost Operator Training Guidebook 5-4 Receiving areas should be large enough to 80:1 and compost slowly without additional store fall leaves and the grass surges nitrogen. expected in the spring and early summer. Table 2: C:N Ratios of Common Materials Recommendation MATERIAL C:N RATIO The best time of year to start composting is Grass Clippings 20:1 autumn, because leaves can be stockpiled Green Leaves 40:1 and available to mix with succulent grass Dry Leaves 80:1 clippings the following spring. Store leaves in Sawdust/wood 500:1 large piles with good drainage, away from chips* property lines, to keep as dry as possible and Dry Straw 100:1 slow the rate of decomposition over winter. Cow Manure 20:1 Food Scraps 15:1 Bulking agents * Carbon in wood is released over a number of years. A bulking agent is a carbon-rich material

added to a compost mix to enhance air flow New Jersey public and private compost or convection through the windrow. facilities recommend no less than three parts Commonly used materials include wood partially composted leaves (from previous chips, leaves, sawdust, cornstalks or straw. In fall) to every one part grass. While this may order to aid natural convection, bulking push the C:N ratio above 30:1, it has the agents must be large advantage of added bulking enough to physically Rule of Thumb material in the mass and support small pockets increasing air flow, which through which air can Mix 2-3 parts leaves to 1 part grass, prevents odors. pass. A compost pile by volume for optimal C:N ratio of with an acceptable C:N 30:1 and add wood chips for bulking Leaves stored over the winter ratio is less likely to agent. lose approximately half their become anaerobic volume by the time they are because sufficient bulking agents are also mixed with spring grass. Due to the volume present to facilitate air flow. reduction that occurs in leaves stored over Balancing C:N Ratios winter, operators who use the three parts brown to one part green rule will actually be The carbon to nitrogen ratio (C:N) of consuming six parts incoming leaves to one incoming materials must be actively managed part spring grass. As shown in Table 1, the in order to have a predictable composting typical generation pattern for communities operation, avoid problematic odors and cannot accommodate this formula. Practical produce consistent, high quality compost. strategies are therefore needed to manage The optimal mixture of yard clippings has a grass effectively. The following materials C:N ratio between 25:1 and 35:1. Too much handling tips offer suggestions on how to nitrogen (C:N below 20:1) results in ammonia balance materials to produce an acceptable odors while excess carbon (above 80:1) C:N ratio. significantly slows the composting rate. Dry brown leaves have an average C:N ratio of

Michigan Compost Operator Training Guidebook 5-5 Pre-processing specifically to handle wet materials. Many The goals of pre-processing include reducing grinders on the market are most effective on the size of brush, creating a homogeneous dry woody materials and require extensive mix, and ensuring that compost mixes have maintenance when handling a wet, green acceptable C:N ratios and moisture levels. mixture.

Particle size reduction The costs and benefits of a commingled yard Tree trimmings and brush over 1" in diameter waste stream should be carefully considered must be physically broken down by a chipper in designing a program. or grinder before they can be added to a Specialized equipment is available to separate compost mix. Unchipped, these materials do commingled brush from smaller particles such not have a sufficiently small surface area to as grass and leaves, and some composters make carbon accessible to microbes. use this approach. This kind of separating Although costly to process, chipped brush equipment can be cost effective because it provides carbon to composting microbes and reduces wear on the hammers and knives in enhances pile aeration by providing structure. grinding equipment. If accepting food scraps Brush can be stockpiled prior to processing with compostable products, you may need to for long periods of time without causing grind this material in order to promote the odors. This allows the operator to chip or degradation of the forks and spoons. grind less often, during slow periods or when Otherwise, you may find small bits of plastic leased equipment is available. in your final product.

Brush must be size-reduced or ground into If possible, grind woody material separately chips in order to compost. Brush mixed with from grass and leaves. Particle size reduction grass and leaves (commingled) can be costly also occurs each time a mechanical windrow to grind with equipment that is not designed turner with knives or blades is used to turn

Recipe Tips: 1. Provide enough space on the site for actively composting windrows, storage of leaves and wood chips, and processing activities. 2. Keep enough leaves and wood chips stockpiled on-site (approximately 1 to 2 months at expected rate of use) to balance the amount of grass that will come to the site in the spring and summer. 3. Incorporate spring and summer grass into leaf windrows incrementally to “stretch” the value of the leaves. The ratio of grass to leaves in the initial mixture should be limited to 1 part grass to 4 parts leaves. Subsequent "doses" of grass added to each windrow should also not exceed one part in four. 4. Repeated incorporations can bring the final grass to leaf ratio to a much higher level, without creating odors, than would be possible using a single incorporation approach. This incremental grass incorporation technique substantially limits odor potential. 5. One good way to form a windrow is to build a grass sandwich: place a load of grass on a leaf/chip layer; add grass; cover with another leaf/chip load, and mix.

Michigan Compost Operator Training Guidebook 5-6 windrows. This cannot, however, be used as odor control. Under no circumstances should a substitute for chipping larger pieces prior to grass be left over the weekend without being mixing into the compost pile. Only brush incorporated into a pile. smaller than 1” in diameter can be mixed into Odors can be generated in localized a pile without pre-chipping if a Scarab or anaerobic pockets in compost piles that have similar turner will be used to turn the piles. acceptable C:N and moisture levels overall. In order to prevent pockets of high nitrogen, Mixing/moistening dryness or excessive moisture, piles must be Incoming material must be mixed and mixed well. watered to achieve the desired C:N ratio (30:1) and moisture level (50-60%). Although Michigan composters are rarely troubled by Materials Handling Tips: lack of moisture, drought conditions can • Grass and food waste must be occur and a method of watering windrows is incorporated into compost piles or essential. Water trucks equipped with windrows within 24 hours of when it overhead hoses can be leased or rented, arrives. because rarely-used, single-purpose Begin composting with an optimal equipment is not cost effective. • moisture content of 55% and C:N Water should be applied to piles when they ratio of 30:1. are “open,” that is, when a concave depression has been made at the top of the • Mix raw materials thoroughly to pile. A triangular or peaked top effectively distribute C:N and moisture. sheds water. • Costs are incurred every time Mixing is essential to good composting. material is moved. Design the site Incoming grass must be mixed into windrows and material handling procedures to or piles within 24 hours of when it arrives. reduce unnecessary relocation of Grass that is already odiferous should be material as it moves through the incorporated into leaf piles immediately. A stations of activity. thin covering of wood chips has been shown as a good bio-filter and further measure of

Compost Production that focuses on minimizing odor production, Site influences thereby increasing the need for more costly Sites constrained by close neighbors may equipment. Turning and screening require additional considerations before a operations on smaller sites must be more composting system is designed. The compost intensive in order to manage the compost system must be appropriate to the site, process and use of space effectively. expected volume and type of incoming Intensive utilization usually requires materials. The proximity of neighbors can additional or more expensive equipment. create the need for a composting approach

Michigan Compost Operator Training Guidebook 5-7

Scarab windrow turner in action at a USDA demonstration site.

Composting systems

Windrow composting Windrow composting consists of placing a windrow turner must be appropriately sized mixture of raw materials into long, narrow for that turner. piles that have a triangular cross-section. These piles, or windrows, are then agitated or It is recommended that windrow height not turned as needed. Windrows are usually exceed 12 feet due to the potential to formed by a front-end loader or dump truck develop anaerobic conditions in the center of and can be turned with bucket loaders or the pile. The lower limit is approximately 3 specialized windrow turners. feet because piles smaller than this are not Dimensions for height and width of a specific insulated well enough to support composting windrow will be related to the machinery temperatures during winter. Current used to create and/or turn it. A pile turned research has indicated that very wide by a front-end loader will be no higher than windrows also impede natural air flow. the loader can reach. A pile turned by a

Michigan Compost Operator Training Guidebook 5-8

Table 3: Windrow Composting Technologies

Compost system Common Size of typical system applications Windrows (w/turners) Yard clippings Small - large volumes, capital intensive

Windrows (w/front-end Yard clippings, Small - medium volumes. loaders) food waste

Trapezoid Windrow Yard clippings Large volumes processed on less acreage (specialized turner)

Trapezoidal windrow composting Trapezoidal windrows are large square shapes built approximately ten feet high. Turning is accomplished by a rotating milling drum with cutters that shaves a thin layer from the windrow and discharges the material laterally to form a new windrow to the side. The trapezoid method was designed to handle large volumes of material on limited acreage. The center of the trapezoid is insulated from the convective forces that take place on the surface of the windrow. Because air cannot penetrate naturally through such a large mass, the center tends to develop extremely high temperatures or anaerobic conditions.

Passive or Static pile composting Passive, or static, piles are essentially windrows turned infrequently with a front-end loader. Piles are limited in height by the reach of the loader, but should not be taller than 12 feet high.

Turning Turning of compost windrows and piles accomplishes the following: homogenizes compost materials, ensures that all materials are located in the center of the pile for some length of time where temperatures are highest, reduces particle size, and temporarily aerates the mix. Turning should occur when the temperature at the center of the pile reaches 140ºF. Turning should occur more frequently in the early stages of composting and less frequently when the composting rate is slower. Sometimes conditions within a pile or windrow warrant more or less frequent turning. This is covered more fully in the section on troubleshooting.

Aeration Aeration within a compost windrow or pile is achieved primarily by natural convection which is a result of the shape of the pile. Cool air flows up from the bottom of the pile through the hot center and out of the top in what is commonly referred to as "the chimney effect". Air flowing out of a compost pile is warm.

Michigan Compost Operator Training Guidebook 5-9 The rate of air flow through the pile will be related to its porosity which, in turn, is related to the size and amount of bulking agents such as wood chips. Figure 1 shows how air flows through compost piles as a result of the chimney effect.

Figure 1 Convection of air through compost piles

Compost “Recipe” affect the composting process, odor Carbon:Nitrogen ratio production and the quality of the finished The mixture or “recipe” used to combine product. organics for compost production is important for a number of reasons. Characteristics of The most important aspect of the compost materials added to a mixture can aid or “recipe” is the Carbon: Nitrogen (C:N) ratio. inhibit the decomposition process, aeration, The best balance for a compost mix will microbial growth and odor production. The permit composting to proceed at an mix of incoming materials can dramatically acceptable rate without generating large volumes of odors that can offend neighbors. A mix too high in carbon will decompose at a slow rate and a mix too high in nitrogen runs the risk of generating ammonia. The relative C:N ratios of grass (20:1), leaves (between 40:1 and 80:1) and woody trimmings (500:1) require balancing to achieve the optimal mixture with a 30:1 ratio. Seasonal generation patterns require that leaves be accumulated on-site in the fall for mixing with grass and food waste as it Summer collections are mostly grass

Michigan Compost Operator Training Guidebook 5-10 arrives in the spring and summer. This grass as a means of reducing grass volumes method of accumulation can be used to accepted at local composting sites. Instead, obtain an overall C:N ratio of almost 30:1. A residents are asked to leave cuttings on the handy rule of thumb for achieving a workable lawn or compost cuttings themselves. Many C:N ratio is to mix two parts brown material communities have reduced the quantities of (high carbon content) to one part green (high grass generated through educational nitrogen content) by volume. programs and economic incentives. Grass cycling with mulching mowers and home Bulking agents composting programs are successful One of the primary reasons for using leaves mechanisms for reducing the cost of or wood chips as a primary constituent in a collection, processing, and potential odor compost pile is the need to provide production of grass. These programs have sufficiently available bulking materials to the helped to reduce monetary and non- compost pile. Bulking agents increase the monetary costs of operating composting porosity of a compost pile which, in turn, facilities. enhances the capacity of the mass to aerate itself through convection. Anaerobic materials The focus of odor prevention is often solely Leaves are the most common carbon based on the composting facility. But all too often bulking agent used with grass clippings odor problems are caused by materials that because they make carbon readily available arrive in an anaerobic state. Grass that has when added to highly nitrogenous fresh grass been placed in plastic bags can begin clippings. Other bulking agents that can be anaerobic decomposition within hours. used include sawdust, cornstalks, or straw. Leaf piles formed in the fall will be half their Facility operators should discourage haulers original size when spring rolls around. from collecting materials and letting them sit overnight or for the weekend in sealed Grass vehicles. Haulers should make an effort to The simplest approach to operating a low collect residential grass clippings early in the odor compost site cost effectively is to week in order to ensure that lawn materials minimize the quantity of incoming grass. As generated on the weekend do not remain indicated above, optimal mixes of leaves to sealed in bags or cans any longer than grass are between two and three parts leaves absolutely necessary. Operating contracts to one part grass, by volume. with haulers can be written in order to allow When a mixing regime of one part grass to compost operators to refuse tipping rights to three parts leaves is followed, the amount of loads of grass at the gate that are obviously grass that can be effectively handled is anaerobic and problematic. This will give approximately 1/6 of the amount of incoming haulers an incentive to work to minimize the leaves. development of anaerobic loads. It will also provide facility operators with the An obvious approach is to reduce the opportunity to reject incoming loads as a incoming quantities of grass. Some Michigan means of corrective action on the behalf of communities have banned curbside set out of the facility and its neighbors.

Michigan Compost Operator Training Guidebook 5-11 Monitoring the compost process degrees Celsius for 24 hours will reveal the Temperature percent moisture. The formula for this is: Temperature must be monitored regularly Wet weight – dry weight/100 = %moisture since it is the primary indicator of the level of It is easiest when you begin with a 10 gram microbial activity and composting rate. sample before drying Temperatures can be monitored using a Improperly assembled and maintained piles temperature probe that penetrates the or windrows may not reach high enough center of the mass. temperatures during the active phase of Active composting occurs within the composting for killing all weed seeds and temperatures of 70 to 145ºF. Temperatures pathogens. below 70ºF are too low (microbes become inactive and weed seeds are not killed offf); temperatures above 160ºF are too high (see the chapter on -Troubleshooting).

Moisture Aerobic microbes need moisture to live. The optimal moisture content of 45-60% moisture can be determined by a simple test called the Squeeze method. Determining moisture content of compost requires measuring both wet and dry weights. Drying compost samples in a soil oven at 110 Soil lab drying ovens

The "Squeeze" method to monitor Oxygen moisture levels: Oxygen meters can be used to determine the oxygen levels of the compost mass, however, Squeeze a handful of compost to see if any the data collected from an oxygen meter is water can be expressed. It should be moist more difficult to interpret than temperature but not wet. Damp as a wrung out sponge. If data. Oxygen meters are also more expensive not, water needs to be added. than temperature probes. If more than a few drops of water can be squeezed out, it may be too wet. If there is Compost curing significantly more water than this, it will be necessary to add dry bulking agent to avoid Compost quality is enhanced by aging, or anaerobic conditions. curing the finished compost to eliminate phytotoxins and stabilize the product. Curing is the final stage of the composting process

that occurs after most of the food supply for the microbes has been consumed. It entails

Michigan Compost Operator Training Guidebook 5-12 placing compost in piles and leaving them further. The degree of maturity can be undisturbed for a period of several months. measured through laboratory tests, seedling Curing occurs when the readily metabolized germination tests or estimated by compost materials in the original feedstock have been reactions in the field. Mature compost is free consumed by microbes. Biological activity of phytotoxins that can interfere with plant drops to a low level, as indicated by failure of germination and growth. piles to re-heat and low demand for oxygen and nitrogen, although moisture and aeration Contamination with soil or uncomposted needs must be met. residues, especially after the active phase of composting has finished, can lead to the Curing can be done before or after screening, reintroduction of weed seeds or plant but it is easier to maintain aerobic conditions pathogens. in the pile if the compost is cured first and then screened. In this way, bulking agents Finished compost can become such as wood chips can still be there to recontaminated with weed seeds if weeds are enhance aeration. allowed to grow and go to seed on or adjacent to the pile or windrow. Keep It is necessary to keep the moisture content vegetation adjacent to stored compost in the curing piles between 40% and 50% to mowed short, and tarp piles or windrows to keep the compost from drying out. If curing prevent contamination by wind-blown weed is to be done in static piles, ensure that seeds. When moving or spreading finished enough moisture is in the piles when they are compost, avoid picking up soil or other formed, since it is hard to uniformly add contaminants from under or around the pile moisture at a later date without turning. or windrow. Mature compost is a dark brown humic material which cannot significantly degrade

Composting Equipment

Equipment choices should be based on the equipment that may enhance marketability of condition and volume of the incoming the final product can be purchased or rented. materials. The need for more sophisticated Changes in the overall waste stream including equipment generally increases as the volume those brought about by climatic differences, of materials processed increases. Organic changes in community growth, and the materials in plastic bags require debagging community’s yard waste management and screening. Brush and other large woody practices can all dramatically affect the type materials need chipping or grinding whether and relative volumes of materials expected at they are commingled with or separated from a site. Facility developers should be aware of grass. All materials composted require community trends before a site is developed mixing. Finally, screeners and bagging

Michigan Compost Operator Training Guidebook 5-13 in order to anticipate long term organic Equipment replacement and preventive management needs. maintenance expenses should be budgeted. Equipment failure during peak times can Equipment selections must be robust and break a composting business. Annual flexible in their ability to withstand changes in maintenance costs can be as much as 10-20% the incoming stream. Equipment must be of the purchase price of equipment. If you flexible because it is less likely to be used carefully monitor and plan regular frequently if it is suited to management of replacement the chances of production only one type or form of material. slowdowns are greatly reduced. Equipment Tips: turning, and moving raw material from one  Lease or rent as-needed equipment such location to another on-site. as grinders and screeners, if used infrequently. Front-end loaders often serve as the most  Use equipment with a history of high important piece of equipment for small quality service; try to do an on-site composting systems. A drawback to using “demo” before purchasing equipment. loaders to turn compost is that thorough  Have a reliable backup processing plan for mixing is more difficult with a loader, because equipment failure. materials mat together. The potential for  Purchase equipment that flexibly suits the unmixed areas within a pile is greater with incoming material and site. loaders than mechanical turners.

Windrow Turners Turning Windrow turners are specially designed for Turning equipment is used to homogenize turning and aerating compost windrows. compost materials, ensure that all materials Large turners are self-propelled, straddle the are in the central portion of the pile where windrow and allow more intensive use of temperatures are highest for some length of land. Smaller windrow turners are side- time and reduce particle size. The two major mounted on loaders or tractors which are types of equipment used to turn piles include: driven in aisle ways beside the windrow. front-end loaders and specially designed Windrow turners mix piles more thoroughly turning equipment. than front-end loaders and generally produce a final product with superior texture. Front-end Loaders Windrow turners are less flexible than loaders Front-end loaders can be used for: compost because they cannot be used to move mixing, pile or windrow formation and material from one area to another and cannot be used to turn static piles.

Table 4: Turning equipment Equipment type Cost Range Capacity Comments Front-end loaders $50,000 to $100,000 500 to 750 cy/hr Small volume systems Tractor-driven $10,000 to $90,000 2,000 to 4,000 Also need a loader or tractor turners cy/hr Self-propelled $40,000 to $200,000 2,000 to 4,000 Large volume systems, smaller turners cy/hr acreage.

Michigan Compost Operator Training Guidebook 5-14

need to be maintained frequently and wear Grinding quickly when grass is processed with brush. Grinding and chipping equipment is used to Chippers and shredders process brush by reduce the size of brush and tree limbs before slicing or cutting it with blades. In general, it is mixed with other materials. This chippers and shredders handle smaller equipment is available in different styles and material than grinders and hammer mills. sizes which vary significantly in price. Table 4 lists cost ranges and capacities for Hammer mills and tub grinders use metal grinders. hammers to break apart material. Hammers

Table 5: Grinding/Chipping equipment Equipment type Cost Range Capacity Comments Grinders $20,000 to $700,000 10 to 500 cy/hr Hammers and a rotating tub reduce size. Hammer mills $17,000 to $250,000 60 to 450 cy/hr Uses hammers to crush materials.

Chippers, $5,000 to $135,000 5 to 300 cy/hr Uses knives and blades to cut materials. shredders

Pug mills use rotating paddles to mix Mixing materials and work faster than batch- Mixing equipment is used to mix organic operated mixers. Batch mixers are adapted materials before composting. Many small from agricultural applications and produce a compost facilities use only front-end loaders homogeneous mix of materials. Windrow to mix materials for composting. Other turners can be considered a means of mixing mixing equipment includes pug mills and compost after it has been formed into batch mixers. windrows. Cost ranges and capacities of screening equipment are listed in Table 5.

Table 6: Mixing equipment Equipment type Cost Range Capacity Comments Pug mills $20,000 to $50,000 20 to 2000 cy/hr Continuous mixing systems, faster than batch mixers Batch mixers $10,000 to $150,000 10 to 500 cy/hr Batch systems, adapted from agric. uses.

chips or any other foreign matter that Screening reduces final product quality. Screening equipment is used to remove large Operators that are interested in marketing particles from finished compost before it is their finished product to specialty markets sold. This includes rocks, twigs, large wood should investigate particle size requirements

Michigan Compost Operator Training Guidebook 5-15 of that market. For example, compost that is essentially a rotating drum with holes that is to be used as topdressing for a golf course either inclined or contains internal flights to would need to have a smaller particle size move material along as the drum rotates. than material that will be used to replant Other types of screens shake or vibrate to vegetation after road construction. separate finished compost from unwanted Trommel screens are commonly used at objects. compost facilities. A trommel screen is

Table 7: Screening equipment Equipment type Cost Range Capacity Comments Screeners $50,000 to $180,000 10 to 200 cy/hr Screen sizes vary. Investigate sizing needs of the markets being served.

equipment is often only cost-effective for Other equipment sites that handle large volumes of material, or Other equipment that can be useful at volumes of food waste that exceed optimal compost facilities is listed in Table 8. This mix ratios and need to be contained.

Table 8: Other equipment Type of Equipment Purpose Comments Debaggers Breaks up plastic bags Finished compost likely to contain plastic pieces Bagging equipment Used to place finished compost Very expensive, used primarily at high in bags volume sites. In-vessel or enclosed Containerized composting Expensive, used mainly where food composters systems to grind and compost waste or bio-solids is the highest food waste, compostable food volume material (not considered yard serving products, animal waste composting) bedding, bio-solids in a controlled environment

equipment have come to the market with Equipment reliability many claims about capability and quality. The resurgence of composting popularity in Some of this equipment was developed for the last few years has driven the markets that handle different materials such development of new equipment and new as agriculture and the gravel and waste approaches. Windrow turners, screeners, management industries. Equipment and other “specialized” composting developed from agricultural applications has

Michigan Compost Operator Training Guidebook 5-16 the greatest number of characteristics in advisable to obtain a guarantee from the common with composting. manufacturer for the cost of service and Development of windrow turners and reworking defective parts. screeners has been an area of great Prototype equipment, while frequently innovation and innovative and effective in difficulty. Facility Equipment "disasters" test circumstances, often operators need to be requires considerable field sure to work with often occur during periods experience before adequate equipment that has been of heaviest use. Develop a durability can be achieved. developed and refined back-up plan for when for use in yard clippings compost programs. equipment fails. Conditions prevalent at a Equipment Tips: particular site also need to be taken into  Talk with other operators to find out what account. equipment they have used and what the In late spring and early summer, an inability service record has been. to turn and incorporate incoming grass can  Have equipment demonstrated on-site mean the difference between idle with your material. If possible, have it neighborhood curiosity and court restraining demonstrated during adverse weather orders. conditions.

 Purchase equipment with a proven track A facility operator should try to purchase record. equipment with a track record. Because  Air conditioning is necessary. composting equipment is a relatively new

development, operators often end up with prototype or early design versions of equipment. Under such conditions, it is

Scarab windrow turner

Michigan Compost Operator Training Guidebook 5-17 Staffing

Qualifications • Train all staff in the basic principles The pool of skilled compost facility operators of composting. is small and it is unlikely that hiring experienced staff is a significant The successes of your employee depends on consideration, particularly at the laborer both training and on-the-job experience each level. However, there is a tremendous need play a role in. Staff will be required to for mechanically talented individuals with the operate and maintain equipment, monitor ability to reason systematically. It is and sample compost piles, administration and necessary to ensure that all site workers gate management. Laborers will also be understand the need for hard work and needed for debagging and other unskilled attention to detail. Operational costs depend jobs. on a number of staff on-site and the effectiveness with which they work. • Initial training Choosing and training staff well are a Initial training should include the basics of significant part of a facility developer’s job. composting operations, data collection, and Large equipment operators and farmers record keeping. Simple operations such as provide a good pool of applicants. recording the temperature of windrows and piles, determining moisture content, and • Hire people who have solid monitoring oxygen levels are all important mechanical skill and demonstrate diagnostic tools which form a lasting record of the daily successes and failures of site attention to detail. management. Like many other long term Personnel utilization is seasonal. The most processes, composting requires early intensive operation of a yard waste attention to indicators of failure in order to composting site is during the late spring, respond to problems on a timely basis. summer and early fall months when most organic materials are generated. The need Another area of importance at any compost for staffing can drop practically to zero in the facility is equipment maintenance and repair. winter when deliveries to the site are limited. All equipment, whether specialized or simple, New hires need a basic understanding of the is under constant pressure to operate. This biology of decomposition and how daily means that preventive maintenance operations might affect that process. programs require religious adherence and Development of successful operations is a that frequently replaced or hard to obtain site-specific process dependent on the efforts parts should be kept in inventory. Because of individual staff members in individual downtime is risky for a compost operation, a situations. talented mechanic must be available in the event that failure occurs in spite of preventive maintenance.

Michigan Compost Operator Training Guidebook 5-18 Safety is an important issue although few composting practice. The most effective standardized rules have been developed to training, however, is achieved in the process cover compost operations. Basic “common of developing an operator’s “feel” for what sense standards” should apply with regard to works on a particular site with a particular safety. Lock-out and tag-out procedures waste stream. should be employed to ensure that maintenance workers and mechanics are not All staff should be encouraged to share injured. All staff should also be aware of insights into successes and failures that occur problematic climatic conditions that can lead on a daily basis. Records of all test and to heightened odor emission, the presence of monitoring should be made available so that aspergillus fumigatus, and other airborne they can be used to inform operating hazards. decisions routinely, rather than only during crisis situations. As an incentive, operators Operators of tub grinders, windrow turners, and staff should be rewarded for their and other heavy equipment should be fully increasing knowledge with the opportunity of trained in the operation of this equipment increased compensation, short courses and and should be required to wear the seminars where they can share their appropriate safety protection. This may experience and learn from others. Encourage include safety shoes, hard hats, eyeglasses or staff to continue composting training through other gear as appropriate. Visitors to the site participation in short courses and seminars. should be restricted from operating areas and should be given standard head and eye protection when they accompany staff into working areas. Exposure to the elements is another concern for workers, particularly under extreme weather conditions.

Training Tips:  Train staff members in proper data collection and record keeping techniques.  Train staff members in proper safety procedures.  Training in equipment maintenance is extremely important.

Ongoing training Training at a composting facility is an ongoing process. New developments in composting practice occur constantly and are frequently presented in periodicals devoted to Trained employees help to maintain consistency and quality.

Michigan Compost Operator Training Guidebook 5-19 Regular Operations Schedule Time period Operation Daily Accept yard clippings, monitor quality, record volumes/weight (trash or debris is removed by person who brought it) Check for odors and take action when necessary. Process (grind or chip) incoming materials, incorporate grass within 24 hours of when it is dropped off. Check site for trash & debris, remove. Check for dust, take action when necessary. Check equipment, lubricate according to maintenance schedule. Maintain pad to provide drainage and access. Weekly Turn windrows when they reach 140 ºF Monitor and record representative area of windrows for temperature and moisture levels. General clean-up of site. Clean equipment. Mix windrows as they reduce in size.

Low-Odor Facility Operations

Remediating odor problems can lead to At facilities where large amounts of grass are increased processing costs, which in turn, processed, composting must be done under increases the need to process larger volumes carefully controlled circumstances. Operating of yard clippings to generate higher standards and methodology play the primary revenues. Site improvements or additional role in maintaining the necessary control, in equipment which might be required to defeat conjunction with a properly conceived and odor problems also require cash. This cycle executed site design. can continue until the facility becomes legally or economically unfeasible to operate.

Michigan Compost Operator Training Guidebook 5-20

It is difficult to maintain low odor operations on lowland sites such as this one near a river.

Problematic odors Table 9: Common odors at compost Composting is a natural process producing little odor in the forest or a homeowner’s sites backyard. Larger amounts of yard clippings Odor Cause increase the possibility of odor generation. A Ammonia Too much nitrogen variety of odors can be produced as a result Amines (fishy smell) Anaerobic conditions of the composting process. Typical odors Sulfides (rotten eggs) Anaerobic conditions include ammonia, amines (fishy smell), Volatile fatty acids Anaerobic conditions sulfides (rotten eggs) and volatile fatty acids. (VFAs) The type of odor produced can provide the compost operator a clue to what’s causing the problem and how it can be remedied.

Michigan Compost Operator Training Guidebook 5-21 Managing Operations Summary

when the windrow or pile is first formed. Factors affecting process and odors Inability to provide the required amount of No matter how big an investment has been moisture will ultimately slow the composting made in facility development, the level of process and require additional management operations management represents the most and expense in the long run. important difference between success and Unusual weather conditions can lead to failure. Odor producing compost sites often circumstances where moisture contents are have difficulties producing a high quality too high. However, excessive moisture finished compost product. The pursuit of contents are sometimes the result of poor maximum compost volume production must recipe mixes with too much grass in the mix be modified by the pursuit as the most frequent of minimal odor production. cause. Excessive grass in Moisture levels should composting mixtures has a Composting rate be maintained between number of bad side effects, especially the If the primary operational 45 and 60% for optimal opportunity for the goal is to maximize development of odors. production of compost, then microbial activity. Turning is a technique the most important task of useful for drying out piles that are too wet facility managers is to produce an appropriate because moisture is released during turning. quality of compost in the shortest amount of Excessive turning of windrows or piles dries time. However, operating experience the materials to the point where moisture frequently demonstrates that production content is below optimal. For this reason the cannot be the only variable considered. turning program should be carefully timed to The rate and quality of the composting maintain the correct moisture content. process can be linked to the health of the Many facilities in Michigan have found it organisms that are decomposing the mixture, effective to turn windrows while it is raining which in turn depends on the C:N ratio, in order to add moisture and to prevent moisture levels and aeration. Whether the excessive evaporation of moisture. This can primary organisms of decomposition are also be helpful in minimizing off-site odors aerobic or anaerobic will also be linked to when turning windrows of anaerobic these factors. material. Moisture Aeration & turning Moisture content of the composting mass is Until recently, few controlled experiments one of the most important management had been completed on the effects of turning variables. Moisture levels should be frequency on outdoor windrows of yard maintained between 45 and 60% for optimal waste. Work performed at the Southeast microbial activity. At most sites the Oakland County resource Recovery Authority appropriate level of moisture is adjusted

Michigan Compost Operator Training Guidebook 5-22 (SOCRRA) during the summer of 1994 clearly Weather conditions demonstrated that aeration within a compost Weather conditions can affect the decision to windrow or pile is related more closely to pile turn in a number of ways. Most importantly, shape and porosity than to turning the site operator must determine the frequency. Turning should not be depended potential for odor generation and upon as the primary mechanism to maintain transmission. oxygen in windrows or piles. Turning of piles that are anaerobic or otherwise odiferous should be done with This research showed that any additional care. It should not be turned on hot humid oxygen made available as a result of turning days when there is little air movement. was removed within hours by the natural Similarly, windrows/piles that are known to microbial activity of composting. Aeration of have low moisture content should not be yard waste windrows or piles is primarily the turned on hot sunny or windy days. Moisture result of static aeration or gas flow through can be added to these piles naturally by the pile, commonly referred to as convection turning on a rainy day. Windrows with high or “the chimney effect”. In order to ensure moisture content should be turned on windy proper aeration of a yard waste windrow or or sunny days to limit additional water intake. pile, the following guidelines are Wind direction is a major in deciding whether recommended: to turn piles. Turning and other odor-causing tasks should be performed when prevailing Recipe winds favor the composter (winds that carry Compost must be prepared with sufficient possible odors away from site neighbors). bulking agents to allow adequate interstitial It is important to monitor wind direction and air flow. postpone activities that release odors when wind is blowing towards most sensitive Moisture content neighbors. Windrows must be prepared so that excess moisture does not inhibit or prevent the flow Time of day of air through the windrow/pile. Turning any kind of composting material has the potential to generate odors. Therefore, Windrow/pile dimension turning should be moderated any time The composting mass should be shaped so residential areas or other sensitive receptors that it has a reasonable surface to mass ratio. (schools, hospitals, churches, office buildings) If the distance to the center of the pile is too might be impacted. large, central portions of the pile will not be Turning during the working day is likely to adequately aerated, and localized areas of generate fewer complaints than turning anaerobic decomposition may occur. during the evening after most families have While windrow/pile turning is not the primary returned home. Weekend work in residential method of aeration, it should be done areas is likely to be risky during the warmer routinely in order to promote homogenous months. and efficient material breakdown. Scheduling of this activity should be done with consideration of the following factors:

Michigan Compost Operator Training Guidebook 5-23 Season Turning operations during the late summer The worst odors are generated when grass is and the fall have a lower chance for odor collected in the spring and early summer. As production than the same operations the season wears on, incoming grass typically completed during the spring and early becomes drier and less odorous. summer.

Summary Table 10: Low Odor Production Compost Facility Recommendations DESIGN ASPECT COMPONENTS

Site Surface Design Pad Surface Slope • Suitable for quick, efficient leachate outflow and stormwater runoff • Minimum 1% slope for rigid and durable pavements •2-5% for gravel, slag, or non-rigid surfaces with daily grading

Site Drainage Design Drainage Conveyance Structures • Capable of conveying leachate and stormwater runoff to retention pond without overflow or percolation • Diversion channels to direct runoff and promote sedimentation removal • Stabilization of steep grades with geotextiles, vegetation, or rip-rap

Retention Pond Design • Required at sites larger than 0.5 acres or those with high water tables • Restrict/control rate of runoff • Adequate design should reduce quantity and increase quality of runoff

Other Factors Site Location • Rural or industrial-zoned areas for outdoor technologies to minimize impact • Away from schools, hospitals, or dense residential sectors

Quantity of Incoming Material • Too much material can cause insurmountable odor and management problems • No more than 5,000 - 8,000 cy/acre/yr • Establish peak site capacity based on equipment. NEVER exceed peak capacity-instead, send additional yard clippings to another site.

Compost “Recipe” • Balance of several factors: C:N ratio; moisture content; pile shape/size; temperature; oxygen; bulking agents

Composting Technology/Operations • Tailor system and operating procedure to type and quantity of feedstock

Michigan Compost Operator Training Guidebook 5-24 MICHIGAN COMPOST OPERATOR TRAINING GUIDEBOOK Best Management Practices for Composting

Part 3: Marketing & Finance

Michigan Recycling Coalition PO Box 10070 Lansing, MI 48901 Phone: 517-974-3672 [email protected]

Best Management Practices for Composting

Facility Financing

6

Introduction

Composting facilities have become an integral component of our solid waste Establishing Project Credibility p. 2 management infrastructure. Finding capital to finance composting facilities, especially Financing Capital Costs p. 5 in light of budget constraints in local Financing Operating Costs p. 9 communities, present both a challenge and Table 1: Financing Sources p. 12 an opportunity for facility developers whether public or private sector. Table 2: Operating Costs p. 13 Partnerships between the public and private sectors, in a range of variations, often result in successful financing strategies.

In the sections following, this module will outline several strategies for financing facility capital and operating costs and help you determine which one is best suited for you based on your needs. We will also address the importance of establishing both project credibility and public acceptance to the ultimate success of your project.

The financing tools best suited for you will depend on a variety of issues, including level of private and public sector involvement, size of proposed facility, support for composting in the community, public/private partnership possibilities, public concern about taxation, and the organizational structure of the compost operator.

Michigan Compost Operator Training Guidebook 6-1

Establishing Project Credibility

The basics of establishing project credibility construction of a successfully operating vary little between the private sector and facility in a community similar to yours. public sector. Neither a private entrepreneur nor a community will be The management team should be: well convinced to fund a multi-million dollar organized, experienced in working with the facility that is poorly conceived or public and community officials, and capable designed. In order to obtain financing for a of selling the project to financiers and the project, developers should be able to community. ensure the following elements within their Technical Skills business plan. Organic waste streams, composting technologies and approaches, and climates 5 Key elements of successful operations: differ dramatically from one facility to the next. Not all technologies are appropriate 1. Developer Credibility in every situation. In order to determine the most suitable technical approach, it is 2. Political Acceptance likely that either a formal or informal 3. Technical Soundness feasibility study will be required during the facility development process. 4. Adequate Revenues Realistic Financial Considerations 5. Regulatory Approval Whether public or private, even the most successful projects encounter difficulties and unanticipated expenses along the way. Developer Credibility In order to avoid frustration and delay as A credible project team has experience in much as possible, the Project Team should designing cost-effective, technically sound carefully review the successes and failures facilities that produce quality compost. of similar existing facilities. Having a source When selecting or assembling a project of contingency funds available to meet team, look for the following elements: unexpected developments should be an integral part of facility financing. Management Skills

Compost facility managers have a multi- faceted job. While they must directly Political Acceptance manage site operators, technicians and The perfect site for a composting facility (or laborers, they must also work to satisfy any other solid waste management facility) customers with quality service and is one far enough from civilization so that products. The project team should be noise, traffic, and odors will not be experienced in managing the design and

Michigan Compost Operator Training Guidebook 6-2

disturbing, while close enough to minimize facility must be taken seriously and given transportation costs to and from the adequate resources if the project is to facility. In reality, these two criteria are succeed. Technical Soundness means: usually competing. quality product in a reasonable amount of time and cost-effective manner, while Gaining political acceptance of a project minimizing nuisances. frequently hinges on where you plan to build the site. Development of a Choice of Technology composting facility within a community is a delicate business. The project developer must make every effort to ensure that their choice is one that Before financing a composting facility, the can succeed. Existing, successful facilities project team should seek a letter of support can provide good reference. The industry is from the host community and the necessary young enough, however, that developers planning and zoning acceptances. Property should not be overly-biased against new that will be purchased or leased should also approaches: if successful, they could well have purchase agreements and lease provide a substantial and competitive agreements contingent on the availability of advantage. project financing. Project Engineer The most effective strategy is to locate the site on public land committed to the The project engineer should be registered project. One way to achieve this is to offer and insured, with experience in designing a financial benefit, such as a reduced tip fee facilities for communities with similar or host community fee, to the community needs. This will ensure that the developer which owns the site. has recourse if the facility is not developed according to contractual specifications. Positive community relations means: Adequate Revenues • sharing development plans Many sites, especially those that • incorporating reasonable criticism concentrate their efforts on processing yard • demonstrating care and concern for the debris, have an uneven flow of revenues project’s impact on businesses and throughout the year. These facilities personal lives require a cushion of resources in order to continue year around operation when tip fees and sales revenues decline in the Technical Soundness colder months. Most compost facilities employ the most basic windrow technologies, and do not Tip Fee Generation require substantial resources to develop a A consistent flow of revenue can be technically sound facility. In fact, with generated from tip fees. These fees should experienced project team members this be at a contractually designated amount for could happen quite efficiently without a defined period. Most facilities attempt to elaborate designs and reports. However, cover operating costs and sometimes the development of a technically sound

Michigan Compost Operator Training Guidebook 6-3

capital recovery as well through the tip fee like California have very stringent revenues. Typically, a compost facility relies regulatory approaches while others have on two sources of revenue: tip fees and little or none. This has the effect of creating material sales. an earlier demand for composting in many areas. However, it is likely that states will Material Sales increasingly move toward some kind of Startup compost facilities are similar to regulation of composting. other small businesses. Every effort must Michigan now requires compost facilities be be made to create adequate cash flow by registered if they produce 7,500 cu yd of developing long-term contracts at compost or more annually. predetermined tip fees, ensuring that a cash cushion is available to carry the Local Requirements operation through slow months, and that high value markets for finished product The most important regulatory and continue to develop. permitting requirements can come at the local level. Here, regulations can be The strength of compost markets varies developed to deliberately encourage or widely between regions directly impede the for a variety of reasons. development of Overall, compost is Prospective facility operators composting facilities. increasingly finding must thoroughly understand Frequently, composters niches, however, as soil the regulatory and permitting interested in starting a amendment, designer site find that local zoning potting mixes, climate in which they intend to and planning agencies horticultural growth develop their compost facility have not considered media, and for specialty composting. Project applications. developers may experience a range of reactions based on Regulatory Approval local folklore about the effects of The regulatory requirements placed on composting sites. compost facilities vary dramatically from state to state and are based on the types of Prospective facility operators must materials being composted. Similarly, thoroughly understand the regulatory and public opinion of composting fluctuates permitting climate in which they intend to between active support and shrill develop their compost facility. Some areas opposition. A clear understanding of the might well impose requirements that are legal requirements and an open, honest too burdensome for successful project approach to gaining approvals are essential implementation. Even where regulations to the success of a facility. appear conducive to facility development, care should be taken to preserve good State Requirements community relations and influence the regulatory climate to make it more The degree of regulation by state favorable to composting. governments varies widely. Some states

Michigan Compost Operator Training Guidebook 6-4

Financing Capital Costs This section provides compost The major disadvantage is the potential entrepreneurs ways to identify appropriate difficulty in obtaining public approval for funding sources. It is not intended to the fee. However, the fee and the solid provide an in depth education but to briefly waste service should be perceived as summarize each approach to developing connected and, if distributed according to sources of capital to assists the user in benefit accrued, this mechanism may create determining an appropriate approach. an incentive for waste reduction or material recovery. This approach is best suited to For quick reference, Table 1, at the end, small, cohesive communities that perceive summarizes the advantages and composting as beneficial and worthy of disadvantages of each type. public funding. Solid Waste Management Fees To fund publicly-owned solid waste projects Fees can be assessed several ways: like composting facilities, public agencies may levy a solid waste management fee on • A flat charge for each residence or all persons owning property and benefiting building from waste collection service or a disposal • By weight or volume of the refuse facility. The public agency may use these received fees to pay for the cost of solid waste By average number of containers or management facilities, for the operation • bags of refuse received and maintenance of facilities, and for the Relative difficulty of collection or payment of principal and interest on • management of received solid waste bonds. • Other criteria unique to the client A fee established by a public vote creates a In some cases, a public notice and a public hearing strong source of revenues and usually is required prior to establishing these fees. results in a more favorable credit rating.

Variable fees are the most equitable type of fee, since costs are based on the amount of Tax Levy service provided. Variable fees can also be Within some public agencies such as an Act based on the difficulty in providing the 185 County Department of Public Works or service (e.g., distance of property to the an Act 179 or 245 Solid Waste Authority, facility). Flat fees, while that are equally the public agency may impose special taxes distributed among taxpayers may not for the purpose of providing solid waste necessarily represent the most equitable management services to residents within a distribution among those receiving solid specified jurisdiction. These services are waste services. increasingly being viewed as including organic material recovery through

Michigan Compost Operator Training Guidebook 6-5

composting. Although this power may vary Bond Financing based on local conditions depending on Two types of bonds may be issued by a property taxation limitations and other public agency: general obligation bonds and factors, some degree of tax levy is usually revenue bonds. Generally, bond financed possible. In any case, without the financial capital facilities must either accept public protection of flow control for a public bids for the facility or adopt a resolution facility, double-barreled bond issues (tax approving a request for proposals. backup plus revenues) may be necessary if this approach is used in financing compost General obligation bonds are issued against facilities. Flow control uses regulatory or the assurance of the financial stability of economic means to direct materials to a the state, city, or public agency issuing the designated facility. Regulatory flow control bond. Each entity has a limit on the amount has been successfully challenged as of debt that it can incur. The issuing body unconstitutional and is not considered a may levy a special property tax to fund the viable means of ensuring supply. issue of waste management district bonds Communities may still employ economic for the payment of facility costs. These flow control, offering favorable tip fees to bonds are special obligations of the city, attract materials to a desired facility state or public agency, not a corporate obligation or indebtedness of the units A tax levy provides a very predictable comprising the bonding authority. revenue stream for program financing. As Proceeds from the sale of the general such, it is well-suited for longer term costs obligation bonds must be kept as a separate such as debt retirement. and specific fund to pay the cost of the facilities or services. A tax levy carries with it certain disadvantages as well, especially when used Revenue bonds are special obligations of to cover program or facility operating the public agency and are payable only costs. Put another way, tax-based systems from pledged facility revenues. A city, state remove consumer choice from the funding or public agency may borrow money and mechanism. Additionally, it can be the issue revenue bonds. Revenue bonds are cause of the second major problem with funded based on the strength of potential tax-based systems: public acceptance. income streams generated by the infrastructure project. The revenues may Tax-funded public services have become include monthly user fees, disposal fees, or politically unpopular in many places of the revenues from sale of materials. United States, an anathema to the meaning of good government, regardless of the All bonds, bond anticipation notes and quality of the service being provided. As interest, and securities issued in connection with the agency fee system, public with financing of solid waste management acceptance must be cultivated and the facilities are tax-exempt, as are revenues provision of services carefully matched with received by the city, state or public agency implementation of the tax collection governing authorities. mechanism. Backed by tax revenues, bonds are the most secure type of tax-exempt financing. The

Michigan Compost Operator Training Guidebook 6-6

market acknowledges this in pricing such Agency Funds debt, with lower interest cost than revenue Public service organizations, whether bonds of the same rating. county, city or public agency, will have access to ongoing agency funds from their The service provider can usually provide annual operations. Larger operations will additional credit support through have an equipment-capital replacement line construction, performance and operating item in their budget and an annual capital guarantee, and the governmental body will appropriation mechanism that guides long- provide “put or pay” contracts. These term capitalization and capital contracts commit the county to guarantee replacement. delivery of a minimum tonnage of solid waste and pay a tipping fee whether or not Advances from other fund reserves in the the guaranteed waste is delivered and the system can be the source of capital that is facility is operating. replaced through the capital replacement payments in that year's budget. New Lease Financing capital acquisitions, if timed correctly or if Capital purchases can also be funded small enough in size, can be fit into this through lease financing. This method is system. frequently used to purchase either fixed equipment to be installed in the facility or This type of funding allows local rolling stock equipment, such as forklift, governments to enter the composting wheel loader, containers, collection business and works well with publicly- vehicles, or windrow turners. The term funded, privately-operated facilities. “lease” is typically for a shorter period Assistance from the public sector can make (three to five years) than bond finance private responsibility for composting a arrangements, and the cost of financing is reality in a community. Operating typically higher. In many cases, however, improvements, such as truck purchases, the security on the lease is provided by the drop-off station equipment, building equipment itself. modifications or processing equipment, can be handled through an agency funding Lease financing of equipment is most useful approach if there is a large enough public when other capital financing approaches organization already in place. Many are not available. However, costs of lease counties with large public works financing are high because shortened terms departments in place may find this require that capitalization be recovered extremely useful. over a shorter period. The cost of lease financing prevents it from being used as an Grant and Loan Opportunities ongoing capitalization strategy. It can, Many states have developed solid waste however, be a useful approach for small management funds, grants and loans, and equipment purchases between major outright subsidies for waste reduction, capital projects or as a means for recovery, and management initiatives. “bootstrapping” a project in its infancy These programs were created to focus when there are few other alternatives for economic development efforts on capitalization. integrated solid waste programming. In

Michigan Compost Operator Training Guidebook 6-7

many projects, inexpensive loan financing quantity than public-sector funding, unlike a makes a project possible. Careful attention large public sector bond issue. to the rules of such funding programs should be paid in order to distinguish the Perceived lack of public sector control is general eligibility of composting facility often the most common argument against development. Many economic private sector project capitalization. There development loans are offered at interest are ways to introduce some control, rates equal to or below the prime rate. however, through licensing, contracts, and flow control. The use of private sector The obvious advantage of grants or public financing does inevitably bring with it the sector loans is that they lower overall risk of abandonment as private sector firms project costs. Loans, while requiring a may go out of business or pursue other payback, may still be advantageous at a five more lucrative markets. percent interest rate. There are drawbacks to a grant program, foremost among them future funding uncertainty. In addition, the timing of grant application, award and receipt of funds can disrupt project development. The effect of any waiting period on reaching program goals must be weighed.

Private Sector Equity and Bank Financing

The public sector can leverage significant investment in solid waste facilities and services from the private sector. Public- sector leveraging can take the form of capitalization through equity contributions, cash reserves from larger private firms, or bank financing allotted to private firms

The public sector may take steps to guide, encourage and control this investment through licensing, goal setting and economic flow control. Private sector financing has an element of uncertainty and unpredictability. Private financing avoids placing an Contingencies include a binding public administrative or tax burden directly on the sector contract that provides appropriate county (ies) or local units. Such financing guarantees and remedies should private can often be implemented more quickly financing fall through. This is one of the since the approval process may be much main reasons that reliance on private sector simpler. As well, private sector financing financing is typically matched with suitable also offers more flexibility in timing and contractual commitments as required by the public sector.

Michigan Compost Operator Training Guidebook 6-8

Financing Operating Costs Operating costs are typically funded help to subsidize total compost facility through a combination of operating costs. revenues. The following section briefly summarizes each approach to developing Once composting facility operations are sources of operating revenue and assists underway, sometimes higher landfill tipping the user in determining whether a given fees can be established to encourage use of approach is appropriate. the new facilities. One advantage to tipping fees is that they equitably apply to all For quick reference, Table 2, summarizes facility users. They can also be easily the advantages and disadvantages of each increased or decreased to cover costs. In type. It also provides the names of contacts the absence of flow control, a disadvantage with experience in the use of the fee. is that fluctuations in the market may result in haulers using other facilities with lower Facility Tipping Fees tipping fees. As a result, revenues cannot Facility tipping fees, paid at the gate of a always be easily predicted. In the presence compost processing facility, are the most of flow control, haulers have complained common method used in other sectors of that tipping fees are higher than those of the solid waste and material recovery competing facilities. industry to cover costs of operation. Facility tip fees… Variable or differential tip fees are used to allocate accurately the cost of processing • are the most common form of each material. For instance, tip fee operating revenue surcharges may be assessed against • should be set lower than rates charged materials requiring additional processing, for other forms of disposal e.g., bagged materials. Where possible, this • can be collected on the basis of weight type of economic incentive provides the or volume operator with an excellent opportunity to use best management practices (i.e., to achieve quicker material degradation or higher quality product) on a consistent basis.

Tipping fees are used in many composting facilities. Differential tipping fees can offset costs and encourage material recovery. Additionally, where service programs are linked, for instance a compost facility at a landfill, tipping fees can be used for cross- Scalehouse and scales at BVSWMA landfill subsidization. If recovery is to be entrance College Station, TX. encouraged, a landfill tip fee surcharge can

Michigan Compost Operator Training Guidebook 6-9

Collection Fees based on the amount of waste placed for This funding mechanism is presently used collection. The recycling service, however, by many refuse haulers to cover both is provided as an add-on service that does collection and disposal costs. It is also used not increase the fees if more recyclables are as a method for funding composting set out. This approach rewards recycling collection and processing services to behavior while increasing costs when they businesses, multi-family complexes and put more trash out. households. Landfill Tipping Fee Surcharge Under a standard subscription service, all Communities that own or host a site may users pay the same fee for collection consider levying a surcharge to landfill services. This easily administered approach tipping fees to align fees with true disposal has the advantage that revenues can be costs, raise funds, and provide a negative simply and accurately predicted. However, incentive for disposal. this type of fee provides no economic incentive to recycle or reduce organic waste A local surcharge offers an effective method production. for capturing the avoided cost benefits that are realized in future years – such as rising A variable rate fee disposal costs – or to structure is another type finance start-up and large of collection fee system Collection fees are usually capital investment costs. commonly used. These established in the form of systems allow the user to A surcharge is also a good pay for refuse collection a periodic subscription means of supplementing proportional to his or her service. operations of recovery actual use. Variable rate efforts throughout an structures should be entire community. As encouraged whenever such, the operation of possible if collection fees are to be used as compost facility would not be substantially a major funding source for composting dependent on this means of funding. facility operations. Instead, funding from a surcharge could be used to do extra things like fund special Among the advantages of this system is that equipment, create education/ promotional it offers an equitable charge based on the programs, and develop markets for volume of material generated and composting. Facilities entirely dependent encourages organic recycling when the rate on this mode of funding suffer in the long structure has lower charges (or no charge) run as resources dwindle. for recyclables. The primary disadvantage is that it costs more to administer. Local tipping fee surcharges may be legally challenged that are imposed by local Bundling of collection fees is a good way of legislation and if private landfills do not guaranteeing user participation. Under this contractually agree to participate. Local approach, the costs for the recycling and surcharges are generally negotiated with yard waste collection are bundled into a the landfill operator in exchange for public single collection fee. The bundled fee is

Michigan Compost Operator Training Guidebook 6-10

sector support of the facility and as part of some compost-based products in different a broader host community agreement. areas around the country lend credence to the claims that market revenues will Another disadvantage arises because a eventually be a considerable source of cash steadily increasing rate of waste stream flow. diversion, composting, and source reduction results in a steadily decreasing Material sales provide the operator with an revenue stream. Thus, if composting additional source of revenue to go along activities are financially dependent on the with tip fees or collection fees. Sales are surcharge as a major revenue source, they directly related to the facility’s success in can be financially encumbered by their own efficiently composting its incoming success. organics. Strong material sales revenues create strong incentives for the operators Some of the collected revenues should be to continue to be good operators. directed to benefit community members directly. Tax reductions, general fund Materials revenues are a good funding subsidies, or special project funding could source for operating costs, but the all be considered. Tipping fee surcharges variability of markets means that no facility can be used: to compensate communities should consider them a sole, or even for road use, odor problems, etc. to primary, source of revenue. Because supply discourage disposal and encourage recovery and demand fluctuate widely, it is difficult and recycling efforts to accurately predict prices and therefore difficult to predict the revenues to be available. Eventually, revenue streams from the sale of materials will become more stable and predictable.

Bagged compost is ready for retail sales labeling

and quality assurance stickers or for wholesale to a retail outlet that will apply its own label.

Material Sales Material sales are another cash revenue stream that can be used to offset costs. Bulk sales may make up the largest portion of your

In general, markets for composted organics business. are becoming stronger. The successes of

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Table 1: Comparison of Financing Sources for Facility Capital

Source Advantages Disadvantages Contacts

Solid Waste Public support creates a Costs may not be equitably County or District Solid Waste Management Fees mandate for development divided between system users Coordinators

Costs are equally distributed Public approval is difficult to BPW, City or County Councils get

District Tax Levies Can be used in conjunction Allocation of tax is not based County or District Solid Waste with bond issue on facility usage Coordinators

Predictable stream of revenue Reduces the leverage of BPW, City or County Councils consumer choice

Require a tax increase

Bond Financing Bonds issued by City, state or Bond payments need to be Bond counsel to cities, states, districts are tax exempt regular or districts

Extremely secure and Repayment often requires Small business assistance predictable financing means “put or pay” contracts agencies

Lease Financing Easier to qualify Limited to “lease-able” Equipment manufacturers and equipment representatives Equipment can be its own security High financing costs Credit agencies

Lease can be arranged quickly Small business assistance agencies

Agency Funds No cost of funds Major facilities could take City Manager, County years to fully fund Executive, and Solid Waste Expenditures can be planned Coordinators in budget cycle Inaccessible to private sector

Sometime capital reserves can Threatened by budget be tapped cutbacks

Public Grants and Low or no cost funding Uncertainty of funding State DNR, Commerce, and Loans EPA officials Provide good seed for other Timing of grants is usually sources longer State legislators

Elaborate rules for grants limit Solid waste consultants fund uses

Private Equity and Unlimited and immediate Financing is risk-averse Local bankers Bank Financing funds for attractive projects Management interference Venture capitalists Management assistance from from financiers Private investor services financiers Small business assistance Reduces tax burden agencies

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Table 2: Comparison of Financing Sources for Operating Costs

Source Advantages Disadvantages Contacts

Facility Tipping Fees Common, well understood Fluctuations in markets County solid waste means of collecting revenue may tip fees to rise and fall coordinators and planners

Can easily be used to create In the absence of flow State DNR and EPA incentives for recovery control, revenues are regulators unpredictable Differential tip fees are a fair way to allocate costs

Collection Fees Common, well understood Costs more to administrate Local solid waste haulers means of collecting revenue When fees are poorly Can easily be used to create applied, costs of incentives for recovery composting can be misrepresented

Landfill Surcharges Can be contractually Illegal for public sector to Privately owned landfills negotiated as part of permit or impose on private landfills support process Publicly owned landfills Steadily increasing rates of Effective means of capturing landfill diversion reduces future year benefits revenue stream

Material Sales Revenues are proportional to Lack of market awareness State and national EPA, size of facility reduces current sales Departments of Agriculture Natural Resources, and Strengthening markets bode Strength of market varies Commerce well for economic strength of regionally facilities Land grant universities

•Composting Council Soil and Bark Producers Assoc. National Recycling Coalition, National Solid Waste Management Assoc.

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Best Management Practices for Composting

Compost Marketing: 7 Concepts & Tools

To produce compost that meets consumer compost are appropriate for specific uses. expectation, it is essential to ascertain the In all cases, the compost operator must potential buyers’ requirements for quality concentrate on delivery of a consistently and quantity when designing the facility. high quality product that is available in Attention to in­coming material, reliable quantities. procedures, and adequate curing will ensure consistently high quality compost. Benefits of Compost p. 2 Compost Market Planning p. 2 A good marketing strategy must Product Quality Standards & Control p. 6 demonstrate the benefits of and Compost Characteristics p. 9 applications for compost to compete Market Sectors p.10 Matching Process to Market Specs p. 11 successfully with other soil products. While Promotion and Distribution p. 16 compost imparts a broad range of benefits to soil and plants, different grades of

Good marketing will include a variety of ways that will attract the attention of the consumer.

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Benefits of Compost

Compost is best known for its soil Mature, properly produced compost has enrichment value. The addition of compost also been gaining recognition for its ability improves the physical, chemical and to absorb odors, bind contaminants from biological properties of soils and potting polluted water and soil, control erosion and mixes. The use of compost for plant growth degrade toxic chemicals. Between purposes requires consideration of factors increased research on the benefits of such as the crop or plant to be grown, type compost as a growth media and interest in of soil at the site, and specific compost its use in bioremediation, the future for characteristics. Benefits of compost as a compost markets is promising. growing media are included in Table 1.

Table 1: Benefits of compost

Physical: •Decreases bulk density, • Improves soil structure and reduces compaction, allows increases water holding better root penetration capacity • Darkens soil and increases • Improves drought tolerance • Reduces soil erosion heat absorption Chemical: • Slowly releases nutrients • Reduces fertilizer needs by up to 50 % • Good source of micro • Increases cation exchange • Buffers soil pH nutrients capacity which enables soil to hold nutrients more strongly and resist leaching Biological: • Increases microbial activity • Good source of micro in soil, releasing nutrients nutrients from organic matter • Increases plant survival rate • Strengthens plant resistance • Produces higher crop yields and growth to parasites • Buffers soil pH • Can reduce soilborne plant • Plants develop thicker and diseases more active root systems in a short period of time.

Compost Market Planning

Composting should be approached as the material, rather than disposal of a waste. production of a revenue-generating organic The shift in focus toward revenue

Michigan Compost Operator Training Guidebook 7-2 generation will affect the quality of the using compost incorrectly. New research finished product and the way customers and field experience is rapidly expanding view compost, resulting in higher demand our understanding of compost properties for the product. Efforts spent in planning to and the ways it can work. produce a quality compost from the start will pay off in returning customers. Identify the people and institutions your potential customers trust for advice Basic marketing strategy and steps: regarding new soil products. Develop a relationship with researchers and extension 1. Understand compost attributes agents at the colleges and universities in your area. Extension agents work regularly 2. Assess volumes and sources of with growers and equipment manufacturers compostables and are well educated with regard to scientific research. The list may also include 3. Identify market sectors in your region researchers, product distributors, journals, and conferences where the industry gathers 4. Survey organic soil product consumers to look at new products and discuss ideas. 5. Identify processing needs Assess Quantity of Available Compostables 6. Analyze cost/benefit markets trade-offs The total quantity of compost produced will 7. Follow your plan affect marketing options, as well as facility sizing and design. Growers may decline to 8. Evaluate results and modify plan try compost because sufficient quantities might not be available to meet the needs Repeat as needed their whole operation.

To determine the annual volume of Understand Compost compost that will be produced, municipal If you aren’t already well-versed in the managers should estimate the volume of organics industry, DO YOUR HOMEWORK! compostables generated within their Specific attributes of compost make it political boundaries. From this figure, the similar to, and therefore a potential amount of finished compost can be replacement for some competing soil calculated, which is roughly one-fifth of products. generated compostables. Private compost operators may have a more complex Compost also offers unique benefits; decision regarding the sizing of their however, negative effects can result from facility.

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Compost Market Planning

Explore regional markets Consider markets within a 50-mile radius of the composting facility. With a low value in The full spectrum of compost market relation to weight, transporting soil sectors should be considered. Because products beyond this range is rarely cost actual markets for compost vary widely effective, even in wholesale quantities. from one community to the next, an assessment of the organics industry in your Survey consumers region is essential to understand the potential for compost use in your locality. When choosing an organic product, buyers look for particular effects such as quick drainage, low weight, durability, or dark Prospective market sectors color. By focusing on a grower's objectives, • Landscaping compost producers can gear their product • Sports Turf to meet those needs, or decide to market • Home Gardening the compost to one they can meet. • Nursery/greenhouse • Agriculture (fiber, food, sod, Soil amendment buyers also examine forestry) service factors such as availability, bulk • New Uses purchase pricing, pickup options, storage and delivery services. • Soil blenders and brokers

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A market survey can help identify potential Analyze trade-offs users of compost products, level of The extra expense required to meet quality demand, price paid for similar products, standards of a higher value market should desired qualities, location, peak demand be analyzed thoroughly. Estimate the profit months, purchase terms and delivery margin for each sector, taking into account conditions. Listed below are five key the extra costs you would incur in meeting questions for representatives of market specifications. Consider the advantages and sectors. disadvantages of finding one buyer for the majority of your compost or of contracting Key Questions for Potential Users out the marketing of your product. • Do you purchase soil products? (topsoil, peat, etc.) Marketing compost requires specialized knowledge, skills, industry contacts and • What are important attributes in time. As the amount and variety of determining product use? compost in the marketplace increases with • How much does your operation new compost facilities coming on-line, consume annually? competition for buyers can be expected to What is the cost per cubic yard for soil • increase. On the other hand, potential products? markets become more familiar and What packaging, delivery, storage, • comfortable with compost with use. payment options are important? Companies that control a big share of the organics market often hire customer service

Get to know the needs of potential users of staff. Their role is to educate consumers on compost in your area before choosing the proper use of the product and ensure where to focus precious marketing dollars. that last year’s product performed Keep an eye on similar products available to satisfactorily and to know ahead of time buyers and look for marketing what custom processing or refinements opportunities. must be done for next year’s product to keep up with the changing needs of their Identify processing needs repeat customers. Raw materials influence the physical and chemical properties of compost. Yard Follow your plan clippings alone tend to produce a compost Once you have surveyed your regional with lower nutrient levels than food waste options and designed a marketing plan, give and animal manures. High rate aerobic it time to succeed. Fits and starts and composting will prevent sour, low pH or changing direction will not yield results as odorous finished products. Removal of quickly as persevering with a well designed visible manmade contaminants is essential plan. for most markets, and requires control of incoming feedstock and screening equipment. Complete curing requires storage space.

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Evaluate results Systematic monitoring of your marketing strategy will reveal its effectiveness. If no one makes it their job to inquire about customer satisfaction, you cannot be certain whether or not they were pleased with the product.

Product Quality Standards and Control

Why have standards? phytotoxicity due to lack of maturity, odor Standards define a material in a way that and other properties allows consumers to match the product with their needs. Standards let consumers Curing takes from one to six months, shop for value and purchase product with depending on complexity of the feedstock known characteristics that produce a and efficiency of the composting process. desired effect. User needs tend to be The curing stage eliminates phytotoxins specific; no single standard of quality is (poisonous to plants), and kills weed seeds universally accepted. However, the and pathogens. Mature compost is a dark Michigan Recycling Coalition and brown humic material which degrades at a Composting Council, and the National much slower rate. The degree of maturity Composting Council continue to refine can be measured through lab tests or compost standards, test methods, and user estimated by compost reactions in the guidelines. field.

Compost Quality Issues All compost products are not created equal. Compost quality is enhanced by curingafter stabilization. Compost is cured when readily Finished compost can vary significantly in metabolized material has been consumed chemical attributes like pH and soluble salt by the microbes. Biological activity drops to content, and in physical qualities like a low level, as indicated by failure of the particle size, color and bulk density. These pile to re-heat and low oxygen demand differences can result from variance in the indicates that moisture and aeration needs initial recipe mix, feedstock characteristics, are met. processing methods, refining steps, and additives. Compost quality is a function of many variables, including appearance, pH, Although native soils buffer crops to some organic matter and nutrient content, extent from variations in pH and other parameters, container-grown plants are

Michigan Compost Operator Training Guidebook 7-6 more susceptible. Commercial growers • Total N, P, K raise high-value crops and can ill-afford o Calcium even small failures due to poorly o Magnesium formulated growing media. Although its o Sodium capacity for storing plant nutrients is o Zinc enormous, compost is not a magical o Manganese treatment for every plant. o Copper o Iron Understanding and effectively o Boron communicating the properties and capacity o Aluminum of your product(s) will ensure their proper o Molybdenum application and overall success in the field. • Chloride • Sulfate Testing • Foreign matter content • Pathogens (Fecal coliforms and Part 115, Solid Waste Management, of the Salmonella sp.), if manures were Natural Resources and Environmental composted Protection Act, 1994 PA 451, as amended, • Maturity test (i.e. Solvita Test) requires that composting facilities maintain records that demonstrate that the composting is being done in a manner that Soil Blending prevents nuisances and minimizes Soil blenders often add ingredients to soil anaerobic conditions. Included in the products to adjust attributes such as pH, records that must be kept is the color, or nutrient value as needed by requirement to perform testing on the customers for specific applications. Possible additives include: finished product. This ensures that the composting process has been completed Table 1. Additives used in Soil Blending and that the end user understands what the Additive Source Objective finished compost contains and how to use Ammonium chemical increases it. Each pile or mix design should have a sulfate fertilizer nitrogen sample tested, on a yearly basis. The content Department of Environmental Quality (DEQ) Bone meal bones increases suggests that the finished compost be phosphorus, tested for the parameters listed below, at a pH Ferric chemical salt lowers pH, minimum. sulfate darkens color, adds iron • Ph Peat partly holds water; • Carbon to Nitrogen (C:N) ratio decayed decreases ship • Electrical Conductivity (i.e. soluble vegetation weight salts) Perlite volcanic ash Increases • Total nutrient analysis

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aeration, falls within the acceptable ranges for all test drainage items. Sulfur element lowers salinity, pH STA participants will:

When adding amendments to compost, it is • Regularly sample and test compost important to measure and mix well for a products based on production volumes homogeneous product. Specialized • Complete test analyses for the compost equipment for metering and blending is properties listed below and simply advisable. report o screen size Work hard at making a consistent product. o pH Higher quality won’t attract customers if o soluble salts they cannot depend on it with every o nutrient content (total N, P2O5, purchase. A container nursery operator will K2O, Ca, Mg) be less forgiving of product deviations than o moisture content some other buyers, because the crop at risk o organic matter content is so vulnerable and valuable. o bioassay (maturity) o stability (respirometry) Products that compete with compost sales o particle size (report only) include: Peat moss, reed-sedge peat, o pathogen (Fecal Coliform or sphagnum peat; manufactured or blended Salmonella) topsoil; and composted animal manures o trace metals (Part 503 regulated (bagged). metals)

MDOT standards • Use USCC approved laboratories to carry out product analyses The Michigan Department of • Provide lab results to USCC as Transportation (MDOT) in partnership with prescribed the Michigan Recycling Coalition and • Make test results readily available and Composting Council (MCC) developed a provide a “Compost Technical Data special provision that sets forth Sheet” to buyers which includes requirements for compost used in MDOT directions for product use, a list of projects. See the Resources section for a ingredients and test results copy of this provision. Compost producers • Assure that the facility and product is in who wish to have their product considered compliance with all state and federal for use in MDOT projects must be enrolled regulations and fully compliant members of the US • Have the right to use the Seal of Testing Composting Council Seal of Testing Assurance logo on products in Assurance (STA) program and provide test compliance with the program results to the Michigan Department of Transportation to certify that their compost

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Compost Characteristics

Quality, stability, consistency, availability, Table 1. Typical ranges of test parameters in and price are key elements in marketing quality compost finished compost as a valuable product. Test Parameter Range Not only do consumers need to be aware that these attributes are present, but the pH 6.8-7.3 they also need to be able to rely on them Soluble Salts 0.35-0.64 dS/m being there with every purchase. (mmhos/cm)

Quality can be established by analytical (1:5 v/v method) testing and demonstration plots. Nitrogen 1.0-2.0% Demonstrations are particularly effective if planted and maintained by someone other Phosphorus 0.6-0.9% than the compost operator. Potassium 0.2-0.5% Moisture Content 45-50% Analytical testing is essential to verify your compost product attributes and also to Organic Matter 35-45% ensure worker safety, avoid environmental Particle Size passes 3/8" screen degradation, and maintain a viable compost Bulk Density 900-1,000 lbs/yd3 process. Producers often forego testing Source: http://ohioline.osu.edu/anr- because it’s costly or they are uncertain as fact/0015.html to what parameters to test and what those results mean. But testing is an important Additional quality factors include: investment in the process and the end Characteristics of both physical and product and provides a wealth of chemical properties concern consumers. information. Physical Characteristics The main purpose of testing compost is to determine the concentrations of • Particle size components and characteristics of the • Odor compost so that an evaluation of its quality • Color can be made. Knowledge of a compost's • Contaminants quality enables it to be used responsibly. The chemical and physical characteristics of Biological/chemical characteristics compost depends on the feedstock. Since • Nutrients (N, P, K) the characteristics of compost can vary • pH greatly, tests have been developed to • Stability measure various important parameters of • Organic compounds, pesticides, the compost. Parameters that are typically herbicides measured are shown in Table 1 below. • Pathogens • C:N ratio (optimal: 10:1 to 20:1)

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Stability is essential if customers are to organic matter content, much is lost from return for additional purchases. If compost stockpiling compost after it is fully mature. produces odors or harms vegetation in any way, a poor reputation will result for the The shelf life of compost from yard compost operator. clippings is estimated at two to five years in Michigan’s climate. After this amount of Consistency of both product quality and time compost will reduce to little more supply are of particular importance when than a mineral soil. The natural process of selling to professionals who need large mineralization causes organic forms of volumes on a regular basis. Inconsistency nutrients, such as nitrogen, to convert to or lack of product at a crucial time can an inorganic form. This occurs over time result in lost business. as mature compost sits and at a higher rate in hot climates, both moist and dry. Price of compost must be comparable to compost sold at nearby facilities. It is also Because of the limited shelf life of compost, important to compare compost prices with operators should store mature compost the price of comparable materials such as only for good reasons (for spring buyers) peat moss and topsoil. and, if unavoidable, store finished compost for 6 to 9 months in large piles to minimize Compost has a limited shelf life. loss of nutrients and organic matter. Part Unlike antique furniture or durable goods 115 Solid Waste Regulations limit storage of that increase or maintain their value as materials for more than three years in most years go by, compost is a perishable cases and limit volumes to no more than product with a limited shelf life. Since the 5,000 cubic yards on any acre. benefits of compost are derived from its

Market Sectors

Compost users can be grouped into six For example: If an operator wanted to categories, each with their own application target golf courses, it would be necessary to quality. Compost operators must become find out what characteristics are important familiar with the specific applications, in material used for the various turf needs and concerns of the market sectors requirements of a golf course. Compost they are targeting. In this way, decisions used in the construction and maintenance made throughout the entire composting of golf greens would have different process will work together to produce a characteristics than that used for fairways. final product that is suitable, even superior, for that market. Market sectors and the relative volume, quality and pricing are included in Table 2.

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Table 2 Compost market sectors Compost Uses Compost is used for a multitude of Sector Quality Volume Pricing purposes, some of which are specific to a Landscaping Medium Medium Medium market sector, while others overlap. Some

general uses include: Sports Turf High Medium High

• Turf establishment (sod, lawns) Home Medium Medium Medium • Erosion control Horticulture • Greenhouse potting mixes

• Golf course construction, Nursery/ High Medium High topdressing greenhouse • Stormwater filter material Agriculture Medium Large Low Final landfill cover • Biofilter for odor control New Uses High Variable Variable • Agricultural usage of compost could potentially be a very large market, however, low profit margins drive down the price for compost sold for agricultural purposes. Exceptions to this trend are specialty crops with high value such as berries, herbs, certified organic crops and even sod, where higher prices for compost can be obtained.

Matching Process to Market Specifications

Assess capabilities and costs of your market research to identify target markets, facility decisions regarding feedstock volumes, quality and processing will be based on the Compost quality is a function of feedstock results of that research. In addition, composition and effectiveness of the purchase of specialized equipment may be processing operation. By conducting necessary in order to produce a finished

Michigan Compost Operator Training Guidebook 7-11 product that is acceptable to the target available form than with leaves. Compost market. made from leaves only (leaf humus) differs from leaf/grass compost and from woody How much compost will you produce compost. High percentages of grass raises annually? the pH of finished compost. The organic matter content of wood-based compost has Rule of thumb: longer durability due to the slow breakdown of lignin and cellulose. 20% of incoming volume (cubic yd) Add equipment, staff, space or supplies to OR make a better product. Flexibility in the production process, such as different size Volume In ÷ 5 screens, allows the facility to accommodate a wider range of consumer needs.

Screening removes contaminants and What does it cost to produce compost for oversize compostables, resulting in a a target market? cleaner product with uniform particle size. The production of compost to meet the Screening compost costs about $2 per cubic needs of a high-value market calls for yard, but can increase its value from the $6- rigorous quality control. Additional 8/cy range to $12-20 [H. Hoitink, BioCycle] equipment to grind or shred incoming The moisture content of compost has a big material or screen the final product is impact on the effectiveness of screening necessary, as well as market. equipment; optimum is 40-45%; less creates dust and more clogs the screen. Formula to estimate production costs per yard of compost produced: [(Amortized Active composting has a natural drying capital) + (Annual op. cost)] ÷ effect over time, but it is difficult in Michigan’s comparatively wet climate to (Est. cy finished compost/yr) = achieve correct moisture content on schedule without controlling precipitation. $__ /cy To guarantee the ability to screen compost prior to spring sales, a facility may need a What feedstocks does the site take in? covered drying area. A roofed, possibly enclosed area where compost can cure A carbon to nitrogen ratio of 25:1-35:1 is protected from precipitation, or be spread ideal for composting without producing out in order to dry as quickly as possible. ammonia odors. To achieve this ratio, Translucent roofing material allows sunlight roughly twice the volume of leaves through and aeration provided by blowers (wintered over) to grass must be available can speed the drying process. whenever forming a windrow. A curing area is very important for quality Wood chips add structure and carbon to the assurance, and should be sized to allow pile, though the carbon is in a less readily finished compost to be stored for a

Michigan Compost Operator Training Guidebook 7-12 minimum of one month. Curing piles use Quality begins with raw materials that have less space per cubic yard than windrowsA minimal impurities when the generator puts shipping, receiving and distribution area yard clippings at the curb. Collection would include a loading ramp, enclosed equipment, public education program and bays, traffic access and parking, storage for gate inspection policies and practices all bags, containers, tools, boxes, pallets, push contribute to ensuring that the compost wall, scales and office. facility will receive clean feedstocks.

An ongoing program to inform haulers Compost Process about exactly what is acceptable at the Organic materials that are composted can facility and the penalties for violating these result in a variety of products because of requirements must be implemented. To different feedstocks, processing techniques maintain quality standards at the gate, the and management controls. Composting operator needs a good inspection program, facilities have typically been governed by requires anactive gate attendant and a the incoming materials or “waste” stream, staging area large enough to dump and with managers pressured to move large inspect loads as received. Maintaining volumes of material through the process as records of haulers using the facility, fast as possible at the including the date, amount and origin of lowest possible cost in One bad experience with equipment, land and each load, enables bad labor. While the compost can cause a loads to be traced. conditions for microbes consumer to consider all Upgrading finished can be optimized to composts to be poor. speed up the compost decomposition process, Finishing activities can the necessary time to produce a mature include curing, refining, screening, compost is often shortchanged. This results amending, storing, vehicle loading, in an unfinished product with a lower packaging, and/or shipping. Each activity quality. Low quality products can tarnish requires space for storage of equipment consumer confidence in compost products. and compost. Equipment such as One bad experience with compost can screeners, shredders, mixers and baggers cause a consumer to consider all composts are used by some compost operators to to be poor. upgrade their final product. Although some of this equipment is quite expensive, Target uses must govern process operators that process large volumes of decisions compost may find them a worthwhile Decisions regarding product quality, purchase. collection methods, processing and refining are dependent upon the uses planned for Staff the compost. The exploration and Improving the quality and consistency of evaluation of market options are the first the finished compost can involve a number step in designing a compost program.

Michigan Compost Operator Training Guidebook 7-13 of additional activities, and potentially Customer service personnel are often additional staff. This should be included in dedicated to that task but many times serve your long term business and marketing multi-task roles as bookkeepers and general plan. office support. To sell your product the operation requires marketing and sales Hiring heavy equipment operators (loader, representatives. Sometimes the same truck, and screener) requires finding people person can fill both roles. with training and experience. Dispatchers for deliveries, loading, payment receipt often requires persons holding commercial driver’s license (CDL) and bonding.

Using Compost

Compost has numerous uses related to soil improvement; biofilters for odor control, bedding for farm animals, and stormwater filtration. Compost is an excellent soil conditioner which can be customized and applied as a soil amendment, mulch, topdressing or as an ingredient in potting mixes. Some specific uses for compost include: Compost characteristics must match plant • Mix with existing soil to create a requirements (e.g. pH, soluble salt levels), superior topsoil and application rates will vary depending on • Use in all landscape areas for soil use, soil type, and plant needs. Often, soil improvement - lawn, flower, has either too much sand or too much clay. vegetable gardens, around trees In both cases, compost use can help and shrubs, bed preparation remediate the soil encouraging proper root • As seed cover when seeding turf development and plant growth. areas • Backfill mix for planting trees and Compost users rely on accurate product shrubs data to obtain and apply compost correctly. • To heel in nursery stock during transplanting • Erosion control • Seedling establishment • Frost-heave control for nursery field crops • Weed control

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• Reclaim disturbed lands have praised the tremendous benefits of • Landfill final cover compost for years, declaring it the best • Plant bed renovation single material to add to soil. • Lawn core aeration & overseeding • Replacement for cover crops However, unlike apple pie, all composts are not good for every occasion in the plant • Topsoil extender, to increase percent of organic matter in kingdom. For example, acid-loving subsoils rhododendrons will respond poorly to the neutral or alkaline pH of compost. • Basis for making compost extracts and teas Long term residual effects There are long-term residual effects from Soils amended with compost show applying compost to soil. Nitrogen and increased water holding capacity reducing other nutrients tied up in compost are the need for irrigation in volumes and released slowly over a number of years. frequency. When used as a mulch or top-dressing, the mineralization rate of compost is much Tips for Using Compost slower because of the wetting and drying that occurs on the soil surface.

More is not always better Soil with 1 percent organic matter (OM) will Excessive use of compost can result in generate 10 pounds of nitrogen per acre reduced plant growth, succulent plants that per year, compared to 100 pounds from soil are disease prone, ground water with 10 percent OM, based on a contamination, and potential surface run- mineralization rate of 8% to 10% of N at off. 72°F. [source: F. Gouin, Better Composting School] Plain compost made from yard clippings will not likely contain sufficient nitrogen (N) causing over-succulence, but a compost product supplemented with manure or fertilizer could. Applying too much compost wastes money and resources, and can jeopardize the crop. Compost used and applied properly, however, will increase the success of almost any project.

Compost isn’t ideal for every occasion. Generally speaking, compost improves soil and helps make most plants healthier. It is a living material, rich with microorganisms and small amounts of slow-release nutrients. Organic gardeners and farmers

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Further research is needed to better ensured a much better response than the understand the long term benefits of traditional farm practice of ploughing down compost, and how to use it, as exemplified added material. In fact, ploughing down in the following findings. Based on compost or manure increases the extensive laboratory and field tests, probability of restricting oxygen supply in addition of compost to compacted, the soil. [Avnimelech, et al.] structurally deficient soils led to consistent improvement of that soil.

Surface application or very shallow mixing resulted in increased crop yields and Promotion and Distribution

Compost does not sell itself. Promotion and Education Leads to Increased Sales In addition to process controls to ensure 1. Target a specific audience. consistent quality, successful marketing 2. A name and logo increases product depends on convincing the consumer to buy identity and recognition. your compost product or products. 3. A detailed user’s guide educates both sellers and buyers about the Some selling points include: product; helps ensure correct application and better results. • Soil benefits 4. Include complete contact • Renewable resource information and a feedback website • Lower cost than peat moss or mail in card. • Recycles beneficial nutrients It is crucial to broadcast a persuasive User’s Guide message about the benefits and advantages of your compost to target audiences A User’s Guide is a great marketing tool that through a variety of media. Establishing can serve to familiarize potential customers continuous, high demand for your product with the advantages of compost use. Some is important to keep product moving, from items that may be useful in a User's Guide running out of space at the site, and having include: old or poor quality compost to remove. Establishing sales goals and a distribution 1. Suggested application rates and strategy before starting the compost procedures for soil types, plantings operation will prevent this. 2. Local case studies of successful uses of your compost 3. Benefits of compost 4. Laboratory results of product testing

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5. Comparisons with other soil • On-site pick up, self-load with products shovels and even containers (by 6. Results of growth trials conducted bushel or cubic foot) by unbiased third party • On-site pick up, operator loads trucks (by cubic yard) Media advertising and publicity • Operator delivers truckloads to Newspapers, television, radio will reach a outlets such as garden store, DPW large audience, especially if timed right to yard for local sales match the interests of prospective buyers • Home delivery by truckload (minimum quantity, pre-payment) Direct Mail • Retail in containers such as plastic or Your best customers may be those who burlap bags, large plant pots. have purchased compost in the past. By • Donations to community programs keeping a mailing list of buyers, and to raise awareness. communicating with them periodically, you can increase re-orders. This also gives you a Work with municipal managers to use direct line to consumer feedback and sends finished compost in parks and roadside a clear message that you care about both landscaping. Signs can be placed so that your product and your customers. they draw attention to the use of compost in public areas. Successful demonstrations Green Industry Expos, Home and Garden can educate residents and businesses about Shows many aspects of compost and increase their confidence in using it. In addition, it is By attending conferences and trade shows important that information regarding where soil blenders, landscapers, and availability of compost, cost, looks, growers go to keep up with developments applications, and overall benefits of and products in their industry. You can increased organic matter in soil be readily network with colleagues, learn about available. competitors, introduce your compost, identify potential buyers, and learn more about what buyers want.

Distribution Methods Increase Sales Making your compost available to consumers by various means will optimize sales levels. Convenience is an important consideration in purchasing decisions for residents and businesses, so provide as many options and as much convenience as possible. Per unit costs for services such as home delivery can be reduced through volume purchase and passed along to the compost buyer. Some distribution programs include: Michigan Compost Operator Training Guidebook 7-17

Public procurement Public agencies such as parks departments and the road commission use substantial quantities of soil products to build and maintain parks, roadside plantings, and landscapes surrounding buildings and institutions. Public sentiment favors use of local, recycled products in place on non- renewable resources, and can be rallied to support your compost marketing efforts. Procurement policies and price preferences for compost products are effective tools for market development.

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MICHIGAN COMPOST OPERATOR TRAINING GUIDEBOOK Best Management Practices for Composting

Part 4: Troubleshooting

Michigan Recycling Coalition PO Box 10070 Lansing, MI 48901 Phone: 517-974-3672 [email protected]

Best Management Practices for Composting

Troubleshooting

8 Introduction Compost operators may perceive complaints from neighbors as unfounded Under normal conditions at a well-designed harassment based on NIMBY attitudes (Not composting facility using sound in My Backyard). However, sensitivity to management practices, most problems can odors and other nuisance conditions is be avoided. However, a number of factors normal and should be anticipated. This is alone or in combination can cause an especially true in residential and operator to lose control of the composting commercial areas where people live and process, resulting in foul odors, leaching, work. Good relationships with your vectors, and inferior product quality. These neighbors will pay dividends when (if) you problems are serious and must be corrected do have problems. or the facility will be susceptible to complaints which can lead to legal ramifications. There have been numerous instances where odor problems have Figure 1: Problem-solving at compost resulted in costly legal fees and permanent facilities closure of the composting facility. Other problems that can trouble compost facilities include dust, noise, litter, unwanted Identify wildlife, site degradation. In addition, operational problems can occur such as Problem piles that don’t heat up sufficiently or temperatures that are too high.

Odor Problems p. 3 Repeat Determine as Temperature p. 6 Cause needed Dust p. 8 Noise p. 9 Flies and other pests p. 10 Remedy Inferior Final Product Quality p. 11 Problem Site-related problems p. 12

Handling Neighbor Complaints p. 13

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The best remedy is to prevent operational taken by the compost operator to remedy a problems from occurring in the first place problem. through proper site design and facility management. However, even with facilities As depicted in Figure 1, problem-solving at that have been designed properly and are compost facilities is a process of identifying well-run, problems can occasionally arise problems, determining their root cause and that must be addressed. applying appropriate remedies. As needed, this process is repeated until the problem is This fact sheet includes information on how under control. to identify a problem and determine its cause. It also includes actions that can be

Problem: Anaerobic smell. Cause: Water pooling on compost pad. Solution: Restore grade and repair pad to remove low spots that allow water to puddle.

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Odor Problems Determine the Cause & Remedy Identify the Problem Odors occur at compost facilities for several reasons. Identifying the source and type of Odor is generally the most frequent and odor can give an indication of the root serious complaint from neighbors of cause of the problem. compost facilities. The first and most important task for the operator is to determine what problematic odors are Ammonia present and where they are being generated. Only then can appropriate An ammonia smell is usually generated in a remedial actions be taken. Compost that is compost pile that contains too much properly made under aerobic conditions will nitrogen-rich material such as fresh grass. have an earthy aroma that is not offensive. Incoming material can already generate However, partly decomposed feedstocks or ammonia odors if it has been closed up in poor composting techniques can generate plastic bags for very long. problematic odors including ammonia, Ammonia can also be generated when hydrogen sulfide (the smell of rotten eggs) carbon has been supplied to the piles in and volatile fatty acids (VFAs). VFAs are particles that are too large, such as uncut compounds for which most people have brush. In either of these examples, there is very little tolerance. too much nitrogen in the original mix for

the amount of available carbon (low C:N While determining that there is an odor ratio). An ammonia odor can also may seem simple, identifying the source sometimes indicate a pH level that is too and cause of problematic odors at a high. compost facility can be complex. Sites are large open areas with many potential odor- If the ammonia odor is related to an producing sources, and odors travel in imbalance in the amount of carbon and unpredictable ways. nitrogen in the recipe (C:N ratio), add more carbon-rich material such as leaves or wood It is essential to determine whether odors chips. It is important that the particle size are generated by piles of incoming material of the carbon source is small enough that it that have not yet been incorporated, or can be used by microbes. A carbon source from a specific compost pile, standing such as brush or very large wood chips may water, holding pond or another source. need to be chipped or ground to a smaller Identification of the source of the problem particle size. is important because the actions required to remedy each of these problems will High pH (greater than 8) can cause differ. excessive ammonia loss and kill bacterial decomposers. If the pH level of a compost pile is greater than 8, add acidic material

Michigan Compost Operator Training Guidebook 8-3 such as leaves or sulfates and avoid adding If the hydrogen sulfide odor is caused by more alkaline material to the pile. wetness, add dry bulking agent, remix and place piles in an area where they won’t be Hydrogen sulfide located in standing water. If insufficient aeration is related to poor structure or A smell of hydrogen sulfide (rotten eggs) compaction, add bulking agent and remix indicates that anaerobic conditions are the pile. If airflow through the pile is present. Anaerobic conditions form if there uneven (short circuiting), turning piles more are not enough air spaces through which air frequently should eliminate the problem. can flow. This can be caused by too much moisture and/or a lack of aeration. A pile Volatile Fatty Acids (VFAs) with too much moisture will lack adequate aeration because too many of the air spaces VFA’s are not only offensive to the olfactory are filled with water. Anaerobic conditions senses, their presence can contribute to can also develop when the pile becomes phytotoxicity problems in finished compacted or air flow through the pile is compost. Like hydrogen sulfide odors, VFA short circuited. Compaction occurs when odors are generated by microbial there are not enough large or rigid particles decomposition that occurs under anaerobic such as wood chips to maintain structure conditions. Because VFAs are generated and air spaces in the mass. under anaerobic conditions, it is necessary to determine why those conditions exist Short circuiting is a term used to describe and eliminate them. the tendency of air to follow the route of least resistance through the pile. Occurrence of VFAs also indicates that Channeling most often occurs in a compost anaerobic conditions are present within the pile that is not mixed during the composting compost pile. The remedy applied should process. In short circuiting, air flows be the same as when hydrogen sulfide preferentially through the channels rather odors are present. than being distributed evenly throughout the mass. Air does pass through the pile If malodorous conditions persist despite when short circuiting occurs, there are taking the actions previously described, it areas or pockets within the pile with no air, may be necessary to time the turning of creating localized anaerobic conditions. compost piles carefully. Turning is best Rapidly falling temperatures within a when done with sensitive receptors in compost pile can be an indication that short mind, such as when it is raining or when the circuiting is causing the odor problem. wind direction is opposite of where sensitive receptors are located. Hydrogen sulfide odors (rotten eggs) indicate that anaerobic conditions are present within the compost pile. This is either because the material is too wet or because there is insufficient aeration.

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Table 1. Summary of Causes and Remedies for Odor Problems

Situation Possible reason Clues Remedy Ammonia High nitrogen level C:N ratio less than Add high carbon odor 20:1 ingredients Slowly available Large woody Increase available carbon carbon source particles, C:N ratio content via leaves, smaller less than 30:1 particle woodchip High pH pH greater than 8 Lower pH with acidic ingredients (leaves) or avoid adding more alkaline material Hydrogen sulfide Material too wet Low temperatures Add dry bulking agent (rotten-eggs) or VFAs Turn to remove moisture (also releases odors) Both odors indicate anaerobic conditions Poor structure Add bulking agent Pile compacted Remix pile and add bulking agent if necessary Insufficient aeration Decrease pile size Pile too large High temperatures Remix pile so that it's smaller, change recipe Airflow uneven or Falling Shorten time between short circuiting temperatures turnings

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Temperature Identify the Problem there is too much carbon or where the structure of the pile is extremely poor. If Temperature of the composting mass is a large amounts of woody material are primary indicator of microbial activity. present in the pile, there is probably too Compost piles that don’t reach the much carbon for the amount of nitrogen temperatures that indicate active present. If the pile settles very quickly, it composting will take much longer to fully can be assumed that structure is the decompose. The ideal temperature range primary problem. for active composting is 105-145º F. Compost piles that have not heated up A combination of cold weather and piles within 3 days of being formed should be that are too small (3" tall or less) can also considered problematic and in need of result in failure of piles to heat up. adjustment. If low temperatures are caused by materials Temperatures greater than 170º F create that are too wet, add dry bulking agent and potential for spontaneous combustion. remix. If dryness is the cause of low Mesophilic organisms thrive from 104°- temperatures, add water or wet 122°F and their activity is inhibited outside ingredients. If the C:N ratio is too high, add of this range. High temperatures can be the high-nitrogen ingredients (grass or “green” result of compost piles that are too big or materials) and remix. If the piles are too too dry, and from lack of heat removal due small, combine piles together or enlarge by to insulation or lack of aeration. adding highly degradable ingredients.

Determine the Cause & Remedy

Low temperatures High temperatures High temperatures can be caused by A compost pile can fail to heat up because insufficient aeration for heat removal within the materials are too dry or too wet. The piles, low moisture levels or because piles material is too wet if the material looks are too large. If high temperatures are soggy and too dry if no water can be caused by insufficient aeration, there will be squeezed by hand out of a handful of adequate amounts of moisture, as compost. Piles should be maintained at 50 determined by the squeeze method. to 60 percent moisture to stimulate and maintain composting organisms and to If high temperatures are caused by low eliminate problems. The “squeeze method” moisture levels, add water, turn and aerate as described in BMP#4: Operations can be to control temperature. If the pile is used to test whether there is enough overheating but sufficiently moist, turn the moisture in the compost pile. pile or increase air flow to release heat. Overheating piles that are over 8 feet tall Other conditions under which material will should be re-built into smaller piles. fail to begin composting include where

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Table 2: Causes and Remedies for Temperature Problems

Situation Possible reason Clues Remedy Pile fails to heat Too dry Can’t squeeze water out Add water up from a handful of compost

Too wet Materials look soggy Add dry material Not enough Large amounts of woody Add nitrogen-rich material nitrogen material

Poor structure Pile settles too quickly Add bulking agent pH too low pH <5.5, garbage-like Add lime or wood ash, re- odor mix

pile too small Compost piles 3' tall or Re-mix and combine piles less

Temp. too high Insufficient Pile is moist (as Turn pile more frequently aeration determined by squeeze or increase air flow. method)

Moderate to low Pile is dry (as Add water, continue moisture levels determined by squeeze turning method)

Pile is too large Height >8’ Decrease pile size Source: The On-Farm Composting Handbook, Northeast Regional Agricultural Engineering Service, 1992.

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Dust Identify the problem dry loads and from handling dry materials at any stage of the production process. The Dust is often considered a problem by very presence of dust from compost neighbors when if drifts off-site. Dust feedstock materials, windrows or finished consists of fine, dry particles that become product is a sign that conditions are too dry airborne easily. It irritates eyes and lungs for composting organisms. and settles on surfaces and affects employees, customers, neighbors and equipment. It is a hazard to workers if it is Remedy the situation inhaled on a regular basis. The singular solution to dust problems is to simply add water. This can be done in a Dust problems have been associated with variety of ways, but often requires aspergillus fumigatus, a fungus whose specialized equipment such as a watering spores can produce an allergic response in truck, hoses or irrigation systems. While susceptible individuals and can cause Michigan’s climate usually provides infections in persons with weakened adequate moisture to prevent dust, one immune systems. Although this fungus is month or season of drought can create omnipresent to varying degrees, it has been significant dust problems. the basis of costly litigation at some composting facilities. Water can be added to incoming yard waste most easily at the pre-processing stage Dust can also clog radiators, foul oil and fuel before the windrow is built. Thereafter, the filters and require more frequent moisture content of active windrows should lubrication of bearings. Dust can also be maintained at 50 to 60 percent. The promote corrosion because it traps squeeze method can be used to test moisture on metal surfaces and its whether there is enough moisture in the insulating properties can cause equipment compost pile. to overheat. Therefore, dust problems should be dealt with well before they Unpaved or dirty roads and other become a nuisance to neighbors. unimproved surfaces should be wet down as needed to keep dust down during Determine its cause extended periods of dry weather. Determine where the dust is originating.

Dust can have many sources. It can come from unpaved or dirty roads, from emptying

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Noise Identify the Problem determine whether or not ear protection is warranted. Noise is a sound that is perceived as unpleasant or unwanted. Noise can affect Talking to neighbors should help to facility employees, neighbors and determine the nature of the noise that is customers. Although noise complaints from troublesome to them. It is also important neighbors are often the driving force behind to identify what times of day neighbors are having to deal with noise problems; noise is most sensitive to noise so that activities at unlikely to harm the hearing of neighbors. the compost facility can be done at a time It can, however, irreversibly damage the that is least disturbing to them. hearing of facility employees or customers. Remedy the situation Excessive noise can be caused by equipment that needs to be maintained, Equipment that is in need of maintenance on-site vehicle traffic, engines, should be given the attention it requires. hammermills, hydraulic motors or the This may mean lubricating bearings or warning signals of loaders and other replacing worn parts. This is important not equipment when operated in reverse. only for neighbor relations but is also Truck traffic to and from the site can also important for the hearing of the equipment cause noise problems. operator and the longevity of the equipment itself. Determine the cause Employees who, of necessity, must work Sound levels are measured in decibels (dB) under extremely noisy conditions should be and the Occupational Safety and Health provided hearing protection and required Administration (OSHA) has set standards for to wear it. Site modifications that can exposure to sound at different dB levels. protect neighbors from unwanted noise Purchase of an inexpensive meter that gives include vegetative buffers or berms around a direct measurement in dB permits the site, installing sound walls and enclosing objective measurement of this often noise-producing equipment. If permitted subjective problem. Exposure of employees by safety regulations, normal backup alarms who work directly with equipment such as may be substituted with intermittent hammermills should be measured to alarms.

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Flies and other pests Rodents and small mammals are attracted to compost piles for the warmth that is Identify the problem provided when the pile is burrowed into. Flies and other pests such as gnats, rodents or other small wildlife are attracted by the Remedy the situation odor of decomposition, and need to be In order to eradicate flies and other insects, controlled for public health and aesthetic anaerobic conditions must be eliminated. reasons. Flies may deposit their eggs on the Remix and turn compost piles if they are compost and the warm, moist conditions too wet and ensure that compost is not just below the surface provide an ideal located in standing water. Drainage at the environment for their larvae. While pests site must be improved if standing water is may become a problem at any compost causing anaerobic conditions. facility, they are often a sign of a poorly managed site. Process control and good Because ammonia is such a strong housekeeping can limit both the number attractant for flies, it is essential to control and impact of pests. ammonia production and kill fly larvae by frequent turning. Determine the Cause Flies and other insects are generally Rodents can be kept away from a compost attracted to semi-anaerobic environments site by turning piles more frequently. and can be attracted to a compost pile from Rodents will not burrow into frequently far away. Points of attraction include grass turned piles or cured piles. clippings and food waste that have not yet been incorporated into a compost pile or organic matter located in standing water.

Insects, mammals and birds can all become pest problems in poorly managed compost sites.

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Inferior Final Product Quality

Identify the Problem Plastic in compost results mainly from An inferior final product will result in low accepting yard clippings in plastic bags. sales and a poor reputation. Problems Bags are removed prior to windrowing, or associated with final product quality: shredded along with the contents and screened to remove plastic bits after • plant toxicity related to immature composting is complete. Debagging is done compost; by hand or machine. Plastic pieces become smaller by turning and grinding, but do not • physical contaminants such as plastic biodegrade. bits, other manmade inerts, and stones; Small pieces of compostable plastic from • chemical characteristics such as odor, accepting compostable products with food high pH and soluble salts content; scraps may remain even after active composting and curing. Screening the pre- • clumping of screened compost. cured or cured product may remove these pieces. • weed growth in screened compost. Contamination with soil or uncomposted Immature compost can interfere with plant residues, especially after the active phase of growth and develop odors during storage. composting has finished, can lead to the Tests for maturity include seedling reintroduction of weed seeds or plant germination and growth, lab analyses, and pathogens. rough field methods. Finished compost can become Plastic and stones can be identified by a recontaminated with weed seeds if weeds visual examination. Screened compost are allowed to grow and go to seed on or should have a uniform particle size, though adjacent to the pile or windrow. Similarly, sizes can vary for different uses. compost can become contaminated with vegetative reproductive structures from Although compost is typically described as some weeds—Canada thistle and having a neutral pH, levels above 8.0 are rhizomateous grasses, for example—if they not uncommon for yard waste compost. are allowed to grow on or adjacent to the Field test kits for various chemical pile. parameters work well. Remedy the situation Determine the cause Compost matures through a process called Phytotoxicity is due to immature compost curing that involves ongoing low levels of or compost that went anaerobic during microbial activity. It begins after active storage. Maturity requires proper curing: decomposition is complete, takes up to 120 time, moisture and aeration. Michigan Compost Operator Training Guidebook 8-11 days in larger piles with good aeration and To prevent clumping, ensure correct drainage, 40-50 percent moisture. moisture content of compost and screening rate to allow enough time for clumps to For most end uses, plastic bits are not break up. acceptable. The best ways to eliminate pieces of plastic is to not accept yard When moving or spreading finished clippings in plastic bags or debag before compost, avoid picking up soil or other composting. Small screens do a reasonable contaminants from under or around the pile job of removing inert particles, but or windrow and avoid adding fresh material screening is costly and small screens after the active phase as it can cause remove extra compost. reintroduction of weed seeds or plant pathogens. Some compostable products may break down completely and others may not, so Keep vegetation adjacent to stored testing products and giving your customers compost mowed short, and tarp piles or feedback on what products to use and not windrows to prevent contamination by to use may reduce this issue. wind-blown weed seeds.

Site-related problems

Identify the problem Determine the cause Even well-designed compost facilities can Poor drainage happens when runoff water experience problems over time due to collects in places that result in standing facility use and poor maintenance. These water (ponding), and the potential for may include ponding, poor drainage and erosion as water flows across the pad. This anaerobic conditions in a retention pond. can be caused by poor pad design or rutting that occurs when heavy equipment Poor site design is almost certain to cause operates on a wet surface. odor production at all but the lowest volume sites. These situations are often Ponding related to poor site design results accompanied by odor because they result in wet areas of the pad even where there from standing water on-site or isn’t much traffic. Where both of these development of anaerobic conditions. problems, (ponding due to equipment Detailed information on site design are traffic and poor site design), are interacting presented in the chapter on Site Design. to create ponding problems, it can be difficult to establish which is greater.

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Development of anaerobic conditions in a surfacing as needed so water will move holding pond can be identified by heavy quickly away from the composting piles and algae and weed growth and/or gas bubbles into a drainage ditch or holding pond. If on the surface of the pond. This could be ponding is related to ruts caused by the the result of anaerobic leachate from activity of heavy equipment, alternate plans compost piles that enters the holding pond must be developed to keep equipment off as runoff. It could also result from organic the pad while it is wet. This can include materials decomposing anaerobically in the allowing only smaller, lighter equipment to holding pond. Placement of fresh grass be used on the pad when moisture levels directly into a holding pond can also result are high. in anaerobic conditions. Anaerobic conditions in holding ponds can Remedy the situation be remedied by effectively handling drainage and ponding problems. In Regardless of why ponding occurs, the addition, sediment traps can be installed integrity of the pad surface must be and the pond’s surface area can be maintained through regrading and re- enlarged.

Handling Neighbor Complaints

Identify the problem contact person to call regarding any Unhappy neighbors may register complaints complaints will send a clear message of with a local or state government regulator concern for neighbors. before letting the compost facility operator know how they feel. It is preferable for an Following up with neighbors after remedial operator to be the first to know about a action has been taken is important so that perceived problem their facility may be they will know their complaints were heard causing. In order to deserve that kind of and the problem was resolved. Regular relationship with neighbors, compost contact with neighbors regarding positive operators must demonstrate an openness events will help to foster good relations. to hearing neighbors’ complaints and willingness act on complaints immediately. Determine the cause The first and most important rule for By reaching out to the surrounding handling complaints is to take each one community at each stage of facility seriously. Is your fencing or berm properly development, educating residents about screening your property? Is the wind the process, and giving tours to show blowing their way today? Did your front procedures for handling materials, fears gage landscaping not get maintained and confusion can be alleviated in advance. properly? Are your trucks leaving a mess on Also, posting the telephone number and

Michigan Compost Operator Training Guidebook 8-13 the roads? Not practicing regular good a prompt, sincere response and clear plan neighbor relations? of action will be appreciated. Corrective action must then be taken quickly, whether Find out why neighbors are complaining a change in procedure, equipment or the and get to the source of it right away. Is facility is required. this a regularly occurring complaint? Periodically survey and talk to your Turning piles, screening and other activities neighbors. Find out what if any complaints that can bother neighbors should be done there are. Ask them to contact you any and with neighbors in mind, whenever possible. every time they have a concern or think By determining when neighbors are most something is amiss. sensitive to certain activities, a compost operator can try to work around those Remedy the situation times. In addition, turning compost piles The best remedy for neighbor complaints is can be done when the wind is blowing in to let the individual or group know what the the opposite direction from sensitive facility is doing to address the perceived receptors or when it is raining. Thoughtful problem. Even if it will take more time than timing of these activities should reduce the they would prefer to eliminate the problem, potential to annoy neighbors.

Conclusion Proper processing of compost will result in the cause can be eliminated and the fewer complaints from neighbors than problem should not repeat itself. haphazard practices. Consistently applied procedures will produce minimal odors, Careful attention should also be given to draw few pests and produce high quality the concerns and complaints of neighbors compost. However, even in well-run with regard to problems at a facility. These facilities, problems can occur. complaints should be addressed quickly and completely. Results of the actions taken to It is important to address these problems remediate a problem should be clearly quickly and with attention to the underlying explained to neighbors as soon as possible. cause of the problem at hand. In this way

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