Manual.Site Managers Handbook[1] · Chemical fertilizer production requires about 42 gallons of...

FOWLER COMPANY Organics Processing Systems & Equipment

2443 Stuart Avenue | Clovis, CA 93611 | Phone: 559-259-5429 | email: [email protected]

Site Managers Handbook

Table of Contents

Introduction…page 2

Chapter 1: History of Composting…page 3

Chapter 2: Basics of Composting…page 7

Chapter 3: Site Selection and Layout…page 10

Chapter 4: Constructing Your Windrows…page 12

Chapter 5: Monitoring the Composting Process…page 14

Chapter 6: Selecting the Proper Turner for Your Operation…page 15

Chapter 7: Turning the Windrow…page 18

Chapter 8: Plastic Bag Removal…page 20

Chapter 9: Figuring Windrow Volume…page 22

Chapter 10: Odor Control…page 23

Chapter 11: Finishing Your Compost…page 25

Chapter 12: Raw Manure vs. Composted Manure, by Peter Aleman…page 28

Chapter 13: Glossary of Composting Terms…page 31



Introduction The purpose of this Compost Site Managers Handbook is to provide some basic guidelines for the composting process and hopefully provide information that will steer you toward a successful program. I hope I have included information that is useful and thought provoking. The information in this handbook is basically a compilation of articles and things I have learned from others while working in the field. I want to thank the friends I have made in this business for sharing their knowledge with me. Like the composters that have come before you, your experiences with differing waste streams will make you one of the minority of knowledgeable composters, now and in the future. The idea of composting is not new. Some of the oldest books in the Bible refer to the dung heap. Only the introduction of specialized equipment and the market value of compost have changed. Aggressive recycling goals and recent diversion mandates have forced composting from the backyards of organic gardeners into the offices of public officials around the globe. Since the first printing of this handbook ten years ago there is an exciting change beginning in the composting industry. The emphasis on composting has shifted from governmental to private contractors and farmers; organic farms are more and more frequent in rural areas. Retail organic-and-natural food business has shown an annual 20% increase in recent years while traditional grocery chains have fed off their leftovers, posting annual increases of barely 3%. The reinvigoration of the rural community may be beginning with pockets of smaller organic farms supporting the local community and visa-versa. Municipal yard waste collection and composting programs are still multiplying but the private sector has discovered the true potential of properly managing the soil that sustains us. People are learning the importance of organically grown product. For instance, the Colorado dentist that is raising organic hay that helped his neighbors horses get rid of colic or the 16 year old youth that started a compost business at his father’s dairy farm and now, after college, manages to record sales in the hundreds of thousands of dollars annually. The world is sick and tired of a synthetic diet that has proven to weaken the immune system and cause cancer; people want healthy food!



Chapter 1: History of Composting EARLY RECORDINGS OF COMPOST USE Composting has been practiced since Biblical times. To benefit crop yield Native Americans taught the pilgrims how to incorporate organic matter into the soil as they planted their seed. The pioneer farmers had no other choice than to rely on organic waste materials to supply the nutritional requirements of their crops. A WORLD IN CRISIS The chemical age brought about the introduction of synthetic fertilizers. A German chemist, Justus von Liebig, is credited as the “father of chemical agriculture”. Beginning in the middle of the last century, he deduced from the ashes of a plant that he had burned, that what nourished plants was nitrogen, phosphorus and potash or potassium carbonate – the NPK of today’s chemical agriculture. It is reported in the book, Secrets of the Soil by Peter Tomkins and Christopher Bird (1989), that Liebig discovered ten years later that “the secret to fertilizing soil lay precisely in this organic excreta (humus and humus acid), not chemicals”. As a result of the misinterpretation of Liebig’s findings, the farming industry began using chemical fertilizers and has been in a vicious cycle ever since. Waste disposal issues have forced the solid waste industry to reconsider the flow of material entering the landfill. The manner in which wastes were handled had to be changed and composting promised a high diversion rate from the landfill at a surprisingly low cost. If properly managed composting is a highly profitable venture. VALUE OF COMPOST What the majority of people do not realize is that a plant grown with synthetic fertilizers has been given a short-term chemical fix. It is the humus content that gives soil the reserve fertility needed to produce optimum yields under the broadest spectrum of growing conditions while still producing plants that are nutritionally well balanced. Chemical fertilizers do not contribute to the humus or organic levels of the soil. In many cases they can burn the young growth and destroy or reduce the microorganisms, which are the life of a healthy soil.



Today there is concern that urban and agriculture chemical use has caused both surface and groundwater contamination as seen by fish kills, well pollution, and human health problems. Specialized large-scale livestock production has become concentrated in certain areas and manure runoff has begun to cause high levels of nitrates to be detected in watershed areas. Composting this manure will stabilize the nitrates and kill the pathogens making the possibility of surface and groundwater contamination remote. BENEFITS OF COMPOST Compost can be applied alone or in combination with synthetic fertilizers. There will never be enough raw organic material available to satisfy the fertility requirements of productive plants around the world. The application of compost either alone or in combination with chemical fertilizers will provide agriculture and horticulture the following benefits: 1. Compost contains nutrients that have been converted into a form that is readily available to plants. These nutrients are released into the soil at a rate that parallels the plants ability to utilize them. 2. Compost stores minerals. Tiny particles called colloids have a negative charge and thus attract positive charged elements such as potassium, calcium, magnesium, iron and copper. Colloids have the capacity to hold minerals. 3. Compost neutralizes toxins in the soil. The organic acids in humus form stable complexes such as aluminum and iron locking up these toxins in a form that is unable to harm plants. Heavy metals are also fixed in stable complexes making them relatively unavailable for uptake by plants. 4. Compost enhances the color of vegetation. The pigments that make up chlorophyll and color plants are manufactured from substances in compost rich soil and air. 5. Compost helps prevent drought conditions. The tilth of the soil is improved by compost which absorbs great quantities of water. The water is stored as a film on tiny crumbs known as aggregates. 6. Compost increases root structure increasing the efficiency of the uptake of nutrients and moisture. Tests show that compost amended soils have root structures 1,000 times greater than chemically grown plants.



7. Compost prevents erosion by absorbing up to 195% of its weight in water. Fertile soils with high levels of humus allow water to soak in slowly. Without humus, rain bounces off the hard packed surface of the land churning up soil particles to form muddy drops of water. These drops run over the surface carrying away valuable soil particles, resulting in erosion. 8. Compost grown produce has a longer shelf life. Compost seems to provide anti-microbial qualities that prolong shelf life for many edible plants. This is an important factor in today’s market. 9. Compost does not consume large amounts of energy while being produced. Chemical fertilizer production requires about 42 gallons of petroleum to produce 110 pounds of nitrogen fertilizer. 10. Compost is an excellent substitute for peat. Peat does not have the fertility of compost, yet compost can provide all the benefits afforded by peat. 11. Compost improves soil tilth permitting better air and water entry. A hard clay soil will become more porous with the addition of compost while a sandy soil will be bound together by the compost particles. 12. Compost is pollution free. Chemical fertilizer users agree that up to 60% of the initial application of nitrogen can not be used by the young plant. Chemical fertilizers are known to be potential pollutants of both ground and surface water by the EPA. 13. Compost brings the city and farm together. By turning a large portion of the waste stream, which can be as much as 60% organic, into compost, cities and farms are working together to help reduce the waste stream. QUICK FACTS ABOUT COMPOST

• Compost is easy to handle and can be stored indefinitely. • Odors at compost sites result from a lack of oxygen when piles are not

properly turned, become too wet or contain material that is high in nitrogen; all of these problems can be eliminated with proper management.

• Composting kills pathogens such as E-coli leaving a safe pasteurized

product.



• Some materials can be composted in as little as six weeks when processed

properly. • Compost market value has remained constant or increased while other

recycled products values have dropped. ACCEPTANCE OF COMPOSTING Composting can be a highly profitable business for anyone. Cities can recover their input costs through the sales of the finished product and avoided landfill costs. Compost is used locally and is a tangible result of community recycling efforts. Those involved with agriculture are learning the far-reaching benefits of sustainable agriculture. Composting is no longer practiced by a handful of dedicated organic gardeners, it is big business. Composting has become THE MOST DESIRABLE SOLUTION for those involved with managing the waste streams created in our environment.



Chapter 2: Basics of Composting WHAT IS COMPOST? Compost is organic matter (leaves, grass, woody material, manure, crop residue, sewage sludge, etc.) which has been converted by microorganisms into lignoproteins or humus for beneficial plant growth. Compost is an organic soil conditioner capable of providing sustained fertility. EXPLANATION OF THE COMPOSTING PROCESS In order to begin composting organic material, three items are needed for the microbes that will actually do the conversion. Item 1. A food source with a carbon/nitrogen (C: N) ratio of 30:1. This ratio is optimum and a slight variance from this ratio is acceptable but will affect the rate at which the material composts. Bacteria and fungi use the carbon and nitrogen in the waste to produce proteins for their growth and reproduction. They require about 30 parts of carbon to 1 part of nitrogen from the raw organic material. When the C: N ratio exceeds 30:1, the composting process slows. Inorganic nitrogen, such as urea or ammonium nitrate, can be mixed with carbon containing material, such as sawdust, to provide the desired 30:1 ratio. If the C: N ratio decreases to 25:1 or less, the bacteria and fungi can not use all of the available nitrogen. Too much nitrogen causes excess ammonia to accumulate, which will cause unpleasant odors when the compost pile is turned. Item 2. Moisture in the range of 40% - 60% by weight. When moisture content exceeds 60% and the weight of the excess moisture will squeeze any air pockets from the windrow making Item 3 (oxygen) unavailable to the microbes. When the moisture content drops below 40% the heating action within the windrow will quickly dry the material, making the microbes become dormant and die. A general guideline for judging moisture content is to grab a handful of material and squeeze it hard, if the material stays in a ball and did not drip when squeezed the moisture content is ok. If the material will not stay together it is too dry. To raise the moisture content 10% in a five-foot high by seventeen-foot wide windrow add approximately ten gallons per lineal foot. To dry the windrow out several daily turnings will be required; this is best done on a dry day. Item 3. Oxygen. This is where the biggest benefit to owning a compost turner lies. Along with providing a mixing and shredding action, Compost turners are



specifically designed to add the maximum amount of oxygen into the windrow giving the microbial life the oxygen they need to live and prosper. Temperature is the leading indicator of whether the ratios of items one, two, and three are correct to begin the composting process. The microbes create heat as they reproduce and therefore are known as thermophilic (heat loving) bacteria. Thermophilic bacteria thrive between 113°F and 165°F. The optimum temperature at which compost should be turned is 145°F at this temperature weed seeds and pathogens are killed. Fresh organic material will need to be turned more often, as the material progresses toward a finished product turning frequency will decrease. When the material fails to heat beyond 110°F the compost can be stockpiled for final curing. Final curing will usually take 30 days. Mature compost will be dark brown to black in color and have a pleasant smell similar to good topsoil. METHODS OF COMPOSTING There are three popular methods of composting, they are as follows:

• Aerated and static piles (this includes aerated bag systems) • In-vessel • Open windrow method

Aerated and Static Piles Composting can be performed in static windrows or piles through which air is forced. The material is placed in a windrow or pile over perforated pipes or a system of grates. Air is blown or pulled through the pipes or grates through the compost. Forced aeration eliminates turning of material but requires blowers and a pipe or grate network to move the air. A minimum of 10 cubic feet per minute per cubic yard of compost is required. Aerated static piles are popular when space limitations are a major concern. Since no aisles are needed more material can be composted per square foot. With an aerated or static pile it is difficult to add water to the material. Forced air will also follow the path of least resistance causing pockets of material to remain uncomposted. Additionally due to the lack of turning, the material is not mixed regularly which results in a much lower recovery ratio. Static pile composting can take a year or longer to produce a composted product. Aerated bag systems are popular when composting in very



close proximity to large residential developments. Aerated bag systems require a large initial investment and repeated purchases of the storage bags. The bags must then be disposed of. In-Vessel This method uses large drums that rotate at about 6 RPM and retain the material within the drum for approximately 3 – 6 days. If properly managed the material is the taken out and windrowed and turned until completed. Another method of in-vessel composting is the raceway. This method is done indoors and is usually fully automated. Material is placed between two concrete walls and is mechanically turned on a regular basis. The machine that turns the material runs on a track located at the top of the concrete wall, moving the material 2 – 3 feet each time it is turned. When the material reaches the end of the raceway it is considered complete. Both types of in-vessel composting require an investment that is usually in the millions of dollars. Open Windrow Method In excess of 90% of compost site use the open windrow method. The reason for this methods popularity is because of its reliability, low cost and time spent managing the material. The open windrow method achieves the highest recovery ratio and the greatest product consistency. This method is easy to manage and requires the lowest capital investment. Specialized compost turning equipment is generally used to aerate the material but initially some sites may use a front-end loader to accomplish this task. Particle Size Particle size is important; it gives the microbes more surface area to work on, enhancing the process. The rotating drum on a compost turner rotates at the proper RPM to help break down the particles after the composting process has begun to weaken cell structure. Shredding material too fine will stop the free exchange of oxygen within the windrow. Incoming wood material may be pre-ground before being put into a windrow. Unless the volume of material requires a full time grinder on site a contractor is generally hired every few months to come in and grind wood products. Leaves and grass clippings and other incoming material do not need to be ground before composting. This material will add porosity to the windrow allowing an enhanced exchange of air within the windrow. It is also a good idea to pre-screen material before it is ground; this will remove dirt and other small material thus prolonging the life of the hammers or grinding head.



Chapter 3: Site Location and Layout The location of a composting facility is extremely important. Although a well managed site may be operated in close proximity to residential housing and never get a complaint from neighbors, this is certainly not the most desirable. Odors can occur if there is a lack of oxygen within the windrow. A composting site will need to be accessible and ideally have the following criteria. 1) Location

a) Distance from residents i) Be aware of wind direction for dust, odor and fugitive plastic and paper ii) Note which direction runoff will drain

b) Accessibility

i) Easily accessible to landscape contractors, refuse haulers ii) Locate as close to your primary material source as possible

c) Waterways

i) Runoff can contaminate ground and surface water, note where the runoff will go and plan accordingly ii) Look for natural drainage buffers or create a biofilter with finished product

2) Base/Soil Conditions

a) Look for good drainage b) The prepared site should have a 1 – 3 % grade c) A paved site is a luxury and not needed in most cases d) Packed clay with a top coat of fly ash, kiln dust or even wood chips are a common surface application

3) Size

a) One acre will hold 2,850 tons of windrowed compost. (5 x 17 windrows spaced 8 feet apart) b) In most cases 3 – 4 batches of compost can be completed in one year for a potential yearly capacity of 11,400 tons per acre c) In addition to the active compost area where the material is windrowed consider allowing for the following:



i) grinding area ii) incoming material storage iii) retail area iv) screening area v) equipment maintenance and tool storage vi) truck scales vii) finished product storage viii) at least 8 foot aisles to allow for watering of windrows and fire department access

4) To estimate your total volume of material: Total daily volume x 316 (receiving material 6 days a week 52 weeks per year) divide by 4 (total number of batches per year @ 90 days each batch) = TOTAL AMOUNT OF MATERIAL ON SITE AT ONE TIME. NOTE: Remember to allow for seasonal changes of incoming volumes, Re: spring grass, fall leaves. 5) Some states have some or all of the following local regulations, check with your state recycling board.

a) Limits on the size of windrows (height and/or length) b) Types of materials that can be composted c) Permits to operate a compost site d) Dust control e) Monitoring of runoff f) Testing of finished compost g) Fire hydrant locations

A compost site is a busy place. It is a good idea to post signs directing traffic flow, general site rules, list of materials that are or are not accepted, safety guidelines, drop off rates and retail purchase prices. A well-managed compost facility can be a good neighbor as well as an attractive model of a communities recycling agenda.



Chapter 4: Constructing Your Windrows The aerated windrow method of composting organic matter is by far the most popular and frequently implemented for several reasons: 1. Low capital investment 2. Less downtime/reliability 3. Highest quality product 4. Contaminate removal is easily done 5. Shortest time frame from raw material to mature compost Construction of windrows is usually done with a front-end loader, walking floor trailer or rear dump truck. Some site managers run all material through a grinder and pull the grinder ahead as the pile is formed. Grinding all incoming material is a waste of resources. Wood and some brush materials need to be ground to reduce the overall size, but with aggressive flails most organic matter will complete the composting process at a particle size that is more than acceptable. Definitely do not pre-grind leaves, grass and manure, as a compost turner can turn it into compost faster and more economically. THE INITIAL MIX When forming windrows, a carbon/nitrogen ratio of 30:1 is optimum. Knowing the feed stock will help achieve this. Follow these rules of thumb; (1) Nitrogen sources will include grass, manure, supermarket produce, sewage sludge (bio-solids). (2) Carbon sources will include leaves, wood, paper and cardboard. It is a good idea to provide the operator with visual guides on the proper width of the windrow. Do not exceed the recommended windrow size for the various compost turners. CATCHING RUNOFF Constructing a semi-permanent windrow of mature compost at the drainage end of the windrow is a cost effective and efficient method of managing runoff. The biofilter is laid-out perpendicular to the composting windrows and is an efficient and cost effective method of managing runoff. A biofilter is also a good tool to



help stem erosion problems. To help keep the biofilter dry, periodic turnings are recommended. See figure 1 for proper orientation of the biofilter ADDING MOISTURE The most common methods of adding moisture to a windrow are with a water truck, drip irrigation lines, pivot sprinkler systems or a holding tank that is pulled by or mounted to the compost turner. Some smaller communities use their fire truck to add water. Windrows can also be formed with a depression at the top to accept water or to add a slurry into the windrow, such as manure, pit manure, sewage sludge or food processing waste. Many green wastes contain more moisture than one thinks but if moisture needs to be added waste water sources can sometime be found by shopping locally.

Figure 1 - Typical Bio-filter Text Box: Bio-filter



Chapter 5: Monitoring the Compost Process Developing files and monitoring windrows is a good method of providing data to support quality control practices. This can involve sampling temperatures and verifying oxygen levels and moisture content. Finished compost can be lab analyzed for particle size, contaminants, and nutrient values. Having this information on file may seem unnecessary but if it is ever required not having it can put those involved in a difficult position. Most state and local regulations only require a temperature log, if there are any requirements at all. This is sufficient to prove if procedures were followed to achieve a total pathogen kill. Windrows should be numbered and records kept detailing what material is in each windrow. Following are some examples of typical temperature monitoring charts.

Field Log

Permanent File Chart



Chapter 6: Selecting the Proper Turner for Your Composting Operation

DESIGN Through our experience we have learned that every compost site has two items, material to be composted and a tractor or loader with a bucket for handling the material. Because a compost turner is used only occasionally it makes sense to make use of existing equipment to aid in turning the compost. This is true except for large sites where a self-propelled compost turner may be needed. Keeping the initial investment to a minimum is critical; equally important are capacity and quality manufacturing practices. To produce marketable compost free of weed seeds nearly every site will benefit from this specialized piece of equipment. STYLES Compost Turners are available in three types or styles. The simplest of which are the PTO-type units. PTO units use a farm tractor to power and pull the compost turner through the windrow. This farm tractor must be capable of ground speeds of ½ MPH (44 FPM) or less while operating at full PTO RPM. To accomplish this, a creeper gear or hydrostatic transmission will be needed. An 80 to 225 HP tractor is needed depending on which turner size is purchased.

PTS612 composting yard waste

The next step up is a high capacity, commercial grade straddle turner that is towed behind a tractor or front-end loader. The towable straddle units have their own engines to power the turning mechanism and require a 60 HP prime mover to pull the unit through the windrow.



The largest sites will require a self-propelled compost turner.

SPB 718 4 WD in Wichita, Kansas

There are many variables at each site, but we have developed several guidelines that should help each user decide which model Compost Turner will suit their needs the best. 1. Assume a full-time site will use the turner about 4-6 hours one or two days a week. The compost turner will not be used every day. 2. Estimate the daily volume of fresh incoming material. 3. Know what is available for a prime mover or if something is going to be purchased. 4. If the waste stream is seasonal or other commitments prevent full-time operation, a decision must be made concerning the amount of time that will be dedicated to turning windrows. This decision must be made before a compost turner can be sized for the site. SIZING FORMULA To find what capacity Compost Turner will be required take the total daily volume and multiply by 90 days. This will equal the total amount of material that will be on site at one time. Take this figure and divide by the number of hours



that will be spent turning material. This will give the number of tons that will need to be turned in one hour. CONTAMINATED SOILS Users have been successful using Compost Turners to process soil contaminated with petroleum and other hazardous material. If your site will be processing contaminated soil contact us for models specifically designed to work with this material.



Chapter 7: Turning the Windrow FREQUENCY Periodic windrow turning with a Compost Turner is the most efficient means to replenish the oxygen supply within the windrow. Temperature readings will be the indicator of when to turn the windrow, generally around 145 degrees Fahrenheit but below 165 degrees Fahrenheit. Proper operation of the turner will assure you that the windrow will remain uniform and will not need to be “dressed” by the loader. A steady ground speed is essential for a neat appearing windrow. Keeping the machine level from left to right is achieved by raising or lowering the wheel(s) with the corresponding toggle switch on the controls located in the cab of the loader. To assure the complete windrow is turned the rear of the skid plate should be almost touching the ground while the leading edge should be raised 1” – 2” higher. PROCEDURE When entering the windrow, keep the turner at an idle until the drum is covered with material, and then slowly rev the motor up to the pre-set level. Continue forward at a very slow walking pace giving the turner ample time to work the material, keep your speed constant. When exiting a windrow decrease the engine RPM as the turner leaves the material, as you begin your turn lift the unit 12” off the ground. After the windrow has been turned, contaminates such as plastic bags, rocks, or aluminum cans will be visible on the top of the windrow or in the alleyways. This is the perfect time to walk the windrow and remove these materials.

Properly Sized Windrows

OVER AND UNDERSIZED WINDROWS



Oversized windrows can be turned by simply lifting a unit to the height needed, although is not a normal practice. Some PTO and LS series turners are not limited to a specific “tunnel” size. As the composting process continues to degrade the material, windrows will decrease in size and should be combined with other windrows. If windrows are not combined and are much smaller than normal the TS and SPB turners are operated in a normal fashion for PTO and LS series machines keep the end of the drum in the center of the windrow as shown in the drawing below.



Chapter 8: Plastic Bag Removal PROBLEM Plastic bags have plagued compost site mangers since the infancy of municipal yard waste composting. Plastic bags cause three major problems: 1) they cause problems with most processing equipment, especially grinders. 2) They cause a blockage within the windrow hindering the natural exchange of oxygen within the windrow. 3) Finished compost that has plastic particles in it has a much-reduced market value. SOLUTION There are several options that can provide possible solutions to the problems created by plastic. The most obvious is to eliminate plastic bags from the waste stream before they reach the site. This can be accomplished several ways, using paper bags which will compost along with the other material in the windrow, using drop off sites to collect materials for the compost site or removal of materials from the plastic bags at the curb placing the bag in separate container. Naturally, there are other options available and you may never totally eliminate plastic from your material. If these previously mentioned ideas do not fit into your program a compost turner has been used successfully to remove plastic bags from the windrow. Here is how it works: The drum has fixed flails that actually split the bags open as the drum rotates, collecting them on the drum. After some bags have collected on the drum, shut the turner off and remove the bags from the drum by hand. This will take 1 – 2 minutes if the drum has not been allowed to get so full of bags that they have wrapped tight on the drum. If the turner is in the middle of the windrow when it is time to remove the bags from the drum, simply shut the unit down and raise the machine. After 3 – 4 passes 85 – 90% of the plastic will have been removed. The plastic that remains will be small in size and should not interfere with the composting process. When the compost is ready to be screened the remaining plastic can easily be removed with a trommel screen. If after screening there is fugitive plastic in the screened product a smaller screen opening may be needed to get this material out.



516 Cougar performing plastic removal



Chapter 9: Figuring Windrow Volume



Chapter 10: Odor Control CAUSES There is really only one reason that composting organic matter creates odors, lack of oxygen. If a windrow is not turned at the proper time the oxygen within the pile is depleted. This causes the composting process to slow or even stop. When the windrow is aerated after it has started to go dormant the material will have a strong ammonia smell. Proper turning of the material at temperatures around 145 degrees will generally stop most odor problems. Sites using a loader bucket to turn material will also notice an ammonia smell at times; this is caused by not getting the material fully aerated with the loader bucket. Also, remember the bigger the pile or windrow the greater the odor when it is opened up. Another cause for odors is too much moisture in the windrow. This situation causes the microbes to diminish and eventually to die out, stopping the compost process. The solution to this problem is to turn the windrow frequently to help dry it out. Springtime influxes of large amounts of green grass can also cause odor problems at compost sites. The cause of this type of odor problem results from the incoming material composting so quickly that the windrow can not provide enough surface area to exchange the oxygen as fast as it is being used. It is important that fresh green grass be windrowed as soon as possible, mixed with other materials with the Turner and have the temperature monitored every couple of hours. If green grass continues to be a problem, save some of your fall leaves or finished compost and mix them with the green grass. Saw dust, wood fiber, paper, cardboard, cotton burrs or even finished compost will work to slow the compost process down to something that is more manageable. Remember that a 30:1 carbon to nitrogen ratio is the target for the initial mix. SOLUTIONS After checking moisture content, C: N ratios and allowing for seasonal changes in material if odors are still a problem there are several solutions that may help the problem. Monitoring wind direction and turning the material when the wind is in the most favorable direction to minimize complaints is sometimes all that is needed. If this is not possible or does not solve the problem an odor control system may need to be purchased. There are self-contained systems that mount directly on the compost turner. This system applies the deodorizer as the material is being turned; this type of system has helped many sites to fully



eliminate odor complaints. Another type of odor control is a mister system that creates a pleasantly odorized barrier that odors have a difficult time transgressing. This type of system can become quite expensive and few sites have had to resort to this type of odor management. DEALING WITH THE PUBLIC Develop a plan on how odor complaints will be handled and instruct your personnel on how to proceed with these complaints. Log every odor complaint and follow up after the problem has been taken care of. If the material is particularly odorous have a procedure to dispose of the material. Remember that the person on the phone could become a strong ally if they are properly taken care of.



Chapter 11: Finishing Your Compost QUALITY Horticultural quality compost will need to meet many criteria including particle size and have a low rate of contamination. Mature compost that contains plastic, wood and other debris will not sell over the long haul on the retail market. A clean feedstock will assure a contaminate-free end product. If wood chips are used as a bulking agent, they will need to be removed by a trommel screen and be reintroduced into the composting process for further degradation. If your feedstock contains plastic bags, aluminum cans or other undesirable material, these will also need to be removed with a trommel screen. PRODUCT READINESS Screening is best done immediately after the material is taken out of the windrow. A moisture content of approximately 30% is optimum for screening but screening can be accomplished at higher moisture contents. A mature yard waste compost that has been properly composted when screened will pass approximately 70% of the material through the screen panel opening leaving approximately 30% of the material as oversized (these percentages will vary with screen panel opening sizes). Mature compost is dark brown, almost black and has few, if any, recognizable pieces of the original material in it. If your product has the above attributes it is ready to be screened. SCREEN LOCATION It is important to locate your trommel screen away from traffic and the customer area. The trommel screen operation requires the operator to back the front-end loader 50% of the time; making it difficult to watch for pedestrians or vehicles. If the screen must be placed in a traffic area post signs or rope the area off making sure everyone understands that this area is off limits. Being located in close proximity to the retailing area is not mandatory but could save some wear and tear on loaders and/or trucks. TROMMEL SCREEN OPERATION The reason a trommel screen works well on organic matter when deck or star screens type screens fail is the tumbling action. There is no substitute for the tumbling action a trommel screen gives the material; the recovery ratio is higher



with a trommel screen. The key to any trommel screen is open screening area. There is a difference between total screening area and open screening area. Open screening area is the amount of air in the screen panel that will allow material to pass through. Total screening area is the total surface area devoted to the screen panels, this area can be covered with structural supports, plate washers and other devices used to attach the screen panels to the drum. The trommel drum should be adjustable from 2 – 5 degrees to tailor the drum angle for various materials. The conveyor that feeds the trommel drum should be aggressive enough to offer a consistent feed rate. If the feed rate is inconsistent, capacity will be sacrificed due to the trommel drums diminished ability to process the incoming material. Another important factor is the ability of the brush to properly keep the screen panels from blinding when screening wet material. A properly designed brush should have the ability to be lifted off the screen panel with a threaded assembly of some type when it is not needed. INCREASED MARKET VALUE A clean finished product has a much higher market value than a product with visible contaminates. Bagging your finished product will also open many markets to you; not everyone wants to buy in bulk. A bagged product also sells for more per finished yard. The agricultural market is at the low end of market value for finished compost, a bagged product sold at garden centers is at the high end. Bagging plants are an investment that takes time as well as money and the decision to purchase a bagging system should be considered carefully.



626 Cougar Trommel screening finished compost



Chapter 12: Raw Manure vs. Composted Manure It is well understood that large amounts of raw organic matter should not be applied directly to soils, until they have sufficiently biostabilized. The application of too much immature manure to the soil can sometimes cause damage to plant growth due to nitrogen starvation and toxic metobolite production.1 More importantly, compost maturity results in higher levels of total nitrogen and higher levels of water soluble humic acids.2 Research also has compared the application of raw manure versus composted manure. In a large study conducted in northeastern Oklahoma in cooperation with Oklahoma State University some interesting responses were tabulated. The text consisted of large plots (67.8 yards by 20 yards = .28 acres) and the results are the average of 10 replications. The test consisted of 4 tons/acre composted manure verses 16 tons/acre of raw manure applied in late August on a field which was planted to winter wheat. A soil test was taken in November and another in April, just prior to harvest. The following table summarizes the data:

The data shows the unexplained effect of the 4 ton/acre of compost verses the higher 16 ton/acre rate of the raw manure in regards to percentage of organic matter, available nitrogen, phosphorus, potassium and increased cation exchange capacity. Even though the compost application consisted of ¼ the quantity of organic matter, it still demonstrated a more positive effect on soil improvement. One reason for this is the composting procedure produces a higher quality form of humic acids that are more stable in soils.



Tissue analysis taken prior to harvest showed the same pattern in the nitrogen and phosphorus levels, as did the soil. The numbers, in the order of control, compost and raw manure, are as follows: %nitrogen –4.66, 4.95 & 4.81, %Nitrate -.48, .44 & .57 and %phosphorus -.33, .41 & .37. Aside from the indications that composted manure has higher fertilizer value and crop response than raw manure, there are more considerations: 1. Freight – The cost of hauling higher volumes is a factor. 2. Environmental – Long term studies3 indicate that after eleven years of continuous applications, even moderately low rates of raw manure (15 to 30 tons per acre) showed nitrate levels to potentially cause soil and water pollution. Furthermore, the high levels of phosphates also accumulated to the point that they could begin interfering with nutrient balances of some crops. 3. Sodium Levels – Several authors4, 5, 6 have demonstrated that repeated applications of raw manure result in accumulations of soluble salts in soils, sufficient to lower yields. This is a very important consideration in areas where sodium levels are already a concern, the lower quantities of compost being a higher beneficial nutrient to sodium ratio. 4. Weed Seeds & Pathogenic Microorganisms – The heat generated during the activity of a properly managed compost pile sufficient to destroy both weed seeds and pathogenic microorganisms.7, 8 5. Odor and Fly Control – Composting manure under controlled conditions, does not lead to the putrid decomposition of uncontrolled raw manure piles. Composting does not result in the odors and fly problems commonly found in uncontrolled raw manure piles. This is an important consideration in areas where feedlots, dairies, hog operations and chicken operations are close to urban areas.9 6. Safe Method of Insecticide Breakdown – As rapidly expanding urban areas use up landfill sites, the wastes produced by agricultural food processing plants needs to be dealt with differently. A concern, however, has been the fate of insecticides in the residues. Composting has been proven to be effective in the breakdown of many insecticide residues such as; diazinon, parathion, organophosphate insecticides, dieldrin and even a reduction in DDT.10



7. Quality Control – One of the most important benefits of composting is that during the composting process, different organic wastes are thoroughly mixed, therefore resulting in even field applications and nutrient distribution. REFERENCES 1. Zucconi, et al, 1981b, “Evaluating Toxicity of Immature Compost,” Biocycle (March/April) 54-57. 2. Riffaldi, et al, 1987, “Water Extracts of Fresh and Mature Farmyard Manure,” Biological Wastes, 65-72. 3. Chang, et al, 1990, “Soil Chemistry after Eleven Years Applications of Cattle Feedlot Manure,” Journal of Environmental Quality, 475-480. 4. Wallingford, et al, 1975, “Present Knowledge on the Effects of Land Application of Animal Waste,” In Managing Livestock Wastes, 3rd. International Symp., ASAE, St. Joseph, MI 580-586. 5. Pratt, et al, 1978, “An Approach to Measuring Leaching of Nitrate from Freely Drained Land,” Nitrogen in the Environment, 223-273. 6. Horton, et al, 1981, “Animal Wastes Effects Upon Crop Production, Soil and Runoff Waters,” USEPA Rep. 600/S2-81230. 7. Knoll, K. H., 1963, “The Influence of Various Composting Processes on Nonsporeforming Pathogenic Bacteria,” IRGRD Bulletin, No. 19:1-7. 8. Rose, W. A., et al, 1968, Investigation of windrow composting as a means for disposal of fruit waste solids, Nat. Canners Assoc. Res. Found., Washington, D.C. 9. Bell, R. G., 1974, “The Role of Compost and Composting in Modern Agriculture,” Compost Science, Nov/Dec, 25-26. 10. A summary of a report from the National Canners Association, Compost Science, ?? issue, pg. 22.



Chapter 13: Glossary of Composting Terms Contributed by Bill Newland

AERATED STATIC PILE - A composting system that uses a series of perforated pipes (or equivalent) as an air distribution system running underneath a compost pile and connected to a blower that either draws or blows air through the piles. Little or no pile turning is performed. AERATIO (For Composting) - Bringing about contact of air and composting solid organic matter, by means of turning or ventilating to allow microbial aerobic metabolism (biooxiation). AEROBIC - 1) The composting environment characterized by bacteria active in the presence of oxygen (aerobes). It generates higher temperatures and is a faster process than anaerobic composting. 2) Occurring in the presence of oxygen. AEROBIC DIGESTION - In this active stage of composting temperatures may exceed 140 degrees Fahrenheit (high enough to destroy pathogens, weed seeds, fly ova, etc.) and there are no excessive unpleasant odors created. The most efficient and rapid processing occurs with enclosed aerobic systems. AEROBIC RESPIRATION - The energy yielding bio-chemical reaction in which the final electron donor is oxygen. AFP - Air filled porosity is the air capacity of compost. AGRICULTURAL RESIDUES - The surplus organic materials produced from the raising and processing of plants and animals. These include but are not limited to manure, bedding, plant stalks, hulls, prunings, leaves and other vegetative matter. ANAEROBIC - 1) The composting environment characterized by bacteria active in the absence of oxygen (anaerobes). 2) Occurring in the absence of oxygen. ANAEROBIC DIGESTION - The energy yielding chemical reaction in which the final electron acceptor is an inorganic molecule. The microflora obtains oxygen from the waste material and peak temperatures may range up to 130 degrees Fahrenheit. This method requires a longer period of time, foul odors are created and some pathogens may survive.



ARTIFICIAL SOIL - A growth medium for plants obtained by mixing soil or inert soil substitutes with stabilized organic matter. BACTERIA - Unicellular or multicellular microscopic organisms. BATCH COMPOSTING - All material is processed at the same time without introducing new feedstock once composting has begun. Windrow composting can be a batch system. BIOASSAY - A laboratory assay (test) using a living biological test organism. BIOAVAILABLE - Available for biological uptake and metabolism. BIODEGRADABILITY - The potential of an organic component for conversion into simpler structures by enzymatic and microbial activity. BIOOXIDATION - Aerobic microbial metabolism of organic or inorganic compounds. BULKING AGENT - The material (usually carbonaceous such as sawdust, wood chips or shredded yard trimmings) added to a compost system to maintain airflow by preventing settlement and compaction of feedstock. CARBON TO NITROGEN RATIO (C: N Ratio) - Numerical ratio of the mass of carbon to the mass of nitrogen; determines the compost ability of a material, and serves as one indicator of product quality. CLEAN GREEN - The source separated yard trimmings and prunings from the urban community; which can be considered as virgin organic material harvested from the urban forest. (See also: VIRGIN ORGANIC MATERIAL) COMPOST (See also: MATURE COMPOST) - The stabilized and sanitized product of composting which is beneficial to plant growth. It has undergone an initial stage of decomposition and is in the process of humification (stabilization/curing). Compost has little resemblance in physical form to the original material from which it was made. Specifically it is an “organic soil conditioner”. COMPOST(ING) FACILITY - A processing facility that receives biodegradable organic material. Prepares it as a feedstock and transforms the feedstock through a controlled natural biooxidative process into stabilized compost. It may also



prepare the compost for specific end user applications, while insuring the delivery of an environmentally safe product. COMPOSTABLE - Organic material that can be biologically decomposed under aerobic conditions. COMPOSTABLE MATERIAL - A material which can undergo physical, chemical, thermal and/or biological degradation under aerobic conditions in a processing facility, such that is enters into and is physically indistinguishable from the finished compost (humus). It ultimately mineralizes (biodegrades to water, carbon dioxide and biomass) safely in the environment and provides beneficial soil amendments. COMPOSTING - The transformation of biologically decomposable material through a controlled process of biooxidation which proceeds through mesophilic and therophilic phases, and results in the production of carbon dioxide, water, minerals and stabilized organic matter (compost and humus). Composting is a natural process to stabilize mixed decomposable organic material recovered from municipal solid waste, yard trimmings, sewage sludge and certain industrial and commercial residues. COMPOSTING PROCESSES - 1) Static reserve – organics are processed by biothermic stabilization and placed in a mesophilic static pile. 2) Low tech – windrows of various sizes are turned by a front-end loader or bulldozer. 3) Medium tech – windrows are turned by a special machine and the moisture/temperature closely monitored. 4) High tech – feedstock is processed in an enclosed vessel, special bin or force aerated pile. CONDENSATE - The moisture sometimes found in aeration pipes that is formed when the temperature falls below the dew point. It often occurs in systems where air is drawn through a composting pile. CONTINUOUS FLOW - A system of composting in which material is continuously added to the process and the end product continuously removed. It is generally used in large operations. CONTROLLED COMPOSTING - A process in which the most important factors are regulated for achieving maximum efficiency, reducing processing time, sanitizing the organic mass and minimizing odors. CURBSIDE PICKUP - The curbside collection and transport of household solid waste to a centralized waste handling facility, such as a transfer station, a



material recovery facility (MRF), an incinerator, or landfill. Waste at curbside may be mixed together in common containers or source separated by the householder. CURBSIDE RECYCLING - A program in which residents separate recyclable products from their trash and leave them at curbside for pickup. CURED COMPOST - The highly stabilized product which results from a prolonged period of humification and mineralization. CURING - The last stage of composting that occurs after much of the readily metabolized material has been decomposed. Provides for additional stabilization, reduction of pathogens, and allows further decomposition of cellulose and lignin. DECOMPOSITION - 1) The conversion of organic matter, by microbial and/or enzymatic interactions. 2) The initial stage in the degradation of an organic substrate, characterized by processes of destabilization of the pre- existing structure. In properly controlled composting decomposition is conductive to a subsequent stage of stabilization (humification and mineralization). DENITRIFICATION - The biological reduction of nitrogen to ammonia, molecular nitrogen or oxides of nitrogen which results in the loss of nitrogen into the atmosphere. DIGESTER - An enclosed composting system with a device to mix and aerate the organic materials. DROP-OFF - A program for private citizens to deposit recyclable materials at a separation center. DRUM COMPOSTING SYSTEM - An enclosed cylindrical vessel which slowly rotates for a set period of time to initiate the composting process. DYNAMIC PILE SYSTEM (See: AERATED STATIC PILE) FEEDSTOCK - The decomposable organic material used for the manufacture of compost. FERMENTATION - An energy yielding chemical reaction in which the final electron acceptor is an organic compound.



FINISHED PRODUCT - A compost material that meets the minimum requirements for public health, safety and environmental protection. It is suitable for use without further processing. FINISHING - The post-processing of compost to size, remove inert contamination or bulking agents and prepare for delivery to the end user. FOOD WASTE - 1) The residual food from residences, institutions or commercial facilities. 2) The unused portion of fruit, animal or vegetable material resulting from food processing or production. FOREIGN MATTER - The non-biodegradable matter contained in compost such as glass, plastic, metal, etc. It is permitted only at low levels in market compost. (Soil and sand are non-degradable but can be very desirable components in some market composts.) FRESH COMPOST - The organic substrate which has been through the thermophilic stage and achieved sanitization. It has undergone partial decomposition but is not yet stabilized into mature compost. Its value in a crop management program is limited to a top dressing or incorporation into the soil where final stabilization can occur. FRESH ORGANIC MATTER - The raw organic substrate for composting before undergoing initial decomposition. GREEN MATTER - The portion of the municipal solid waste stream consisting of grass clippings, tree trimmings, garden residues, leaves, and other vegetative matter which has not been commingled with MSW. HAMMERMILL - A powered machine using rotating or flailing hammers to reduce the size of materials. HAZARDOUS COMPOUNDS - They are any organic or inorganic materials that may endanger life or health at a certain level. They include poisons, heavy metals, pesticides, herbicides, etc. sometimes found in mixed MSW. HEAVY METALS - The trace elements regulated because of their potential toxicity to plants and animals. They include but are not limited to cadmium (CD), copper (CU), chromium (CR), mercury (HG), nickel (NI), lead (PB), and zinc (ZN).



HOT BED - A cultivation or rooting bed in which a layer of decomposing (heat producing) organic matter underlies a layer of cultivated soil or artificial substrate. HUMIC ACID - The main constituent of humus, composed of proteins and partially degraded lignins. It is dark brown to black in color. HUMIFICATION - The process of making humus. HUMUS - A complex aggregate of amorphous substances formed during the microbial decomposition of organic residues and other products synthesized by the soil organisms. Humus has a high capacity for base exchange (CEC), water absorption and combining within organic soil tractions. Cured compost may be designated by the general term “HUMUS”. IN VESSEL COMPOSTING - A system using mechanized equipment to rapidly decompose organics; which are enclosed within a drum, tank or other structure while the oxygen, moisture, temperature and agitation are closely controlled. INCUBATION STUDY - A study done in a laboratory setting with controlled temperature, moisture and feedback. INERTS - The non-biodegradable products contained in compost (glass, plastic, metal, etc.) and permitted only at low levels in marketable compost. INOCULA - The preconditioned microorganisms or compost added to a raw material to ensure that the appropriate microorganisms are present for decomposition. INORGANIC - A substance in which carbon to carbon bonds are absent (I.E. mineral matter). INTERMEDIATE PROCESSING CENTER - A facility to handle already segregated recyclable materials from the curbside source separation program. LAND RECLAIMATION - The restoration of productivity to lands made barren through processes such as erosion, mining or land clearing. LATENT METABOLISM - The metabolic processes that remain to be completed before achieving stabilization. Latent metabolism may be measured by the evolution of restoration, heat production, toxicity and other criteria under appropriate conditions.



LEACHATE - 1) A liquid, which has percolated through or condensed out of solid wastes and extracted, dissolved and suspended materials. 2) A liquid that drains from the mix of fresh organic matter. LIGNIN - The complex amorphous organic component of wood that acts as the binder between cells and is responsible for its rigidity. It decomposes very slowly by microbial action. MATERIALS RECOVERY FACILITY (MRF) - An operating plant designed to recover commingled, recyclable materials that may not have been segregated through curbside recycling or original source separation. MATURE COMPOST (See also: COMPOST) - The stabilized and sanitized product of composting which is beneficial to plant growth. It has undergone an initial stage of decomposition and is in the process of humification (stabilization/curing). It is characterized as rich in readily available forms of plant nutrients, poor in phytotoxic acids and phenols and low in readily available carbon compounds. MESOPHILIC PHASE - Phase of composting that occurs between 68 to 113 degrees Fahrenheit. METABOLISM - The sum of the chemical reactions within a cell or whole organism including the energy-releasing breakdown and molecules (catabolism) and the synthesis of complex molecules and new protoplasm (anabolism). MICRONUTRIENTS - The nutrients needed by plants in small quantities for healthy development. MICROORGANISMS - Small living organisms visible only through a microscope. MIXED ORGANICS COMPOST - Compost made by using a variety of decomposable materials as feedstock. Refers to compost manufactured from the organic materials recovered from the municipal solid waste stream. MOISTURE CONTENT - It is determined by the mass of water lost per unit of dry mass when the material is dried at 103 degrees Celsius (217 degrees Fahrenheit) for eight hours or more. The minimum moisture content required for biological activity is 12-15% and, generally it becomes the limiting factor below 45%. In any type of marketing operation 25% moisture content is the standard.



MULCH - A layer of organic material applied on or near the top of the soil for stabilizing the surface and improving the microclimatic conditions for establishing vegetation. It reduces erosion, retains water, improves tilth and provides valuable organic soil components. Mulch is compost that is not completely stabilized. MUNICIPAL SOLID WASTE (MSW) - The discarded material from residential, commercial and institutional sources from which decomposable organic materials may be recovered for compost feedstock. MUSHROOM COMPOST - A cellulose rich organic matter that has undergone the initial decomposition stage of a controlled compost process. The fungi bring about cellulysis and humification of the substrate (stabilization stage). ORGANIC - A substance which includes carbon-to-carbon bonds. ORGANIC CONTAMINATES - The synthetic trace of organics including pesticides and polychlorinated biphenyls (PCB’s). ORGANIC MATTER - The portion of the soil that includes microflora and microfauna (living or dead) and residual decomposition products of plant and animal tissue. Any carbon assembly, large or small, dead or alive, inside the soil space. Humus is entirely organic matter. ORGANIC SOIL CONDITIONER - The stabilized organic matter marketed for conditioning the soil structure. It improves certain chemical and biological properties of the soil. PATHOGEN - It is an organism, chiefly a microorganism, capable of producing an infection or disease in a susceptible host. The term includes viruses, bacteria, fungi, and all form of animal parasites and protozoa. PERCENT MOISTURE - The weight of the water in a material divided by the total weight of the material and expressed as a percent figure. PH - Is the negative logarithm of the hydrogenion concentration of a solution. It is the value used to determine the degree of acidity or alkalinity of a material. Below seven is acid. Seven is neutral. Above seven is alkaline (basic). PHYTHOTOXIC - Any substance or condition detrimental to plant growth. It can be the presence of a contaminant or a nutrient deficiency.



PHYTHOTOXIN - Any substance causing growth reduction or death in plants. PLUG FLOW - Refers to conditions when a batch of material enters a composting system and moves through with only local or incidental mixing. RECYCLABLES - Material which can be separated from the waste stream and used again either in its present form or manufactured into another product. RECYCLE(ING) - The returning of used products (that would otherwise be discarded) for processing into new products. It reduces the consumption of virgin and non-renewable resources. RESPIRATION - The metabolic function of consuming oxygen. RUN-OFF - Precipitation which reaches the area surrounding the compost pad without passing through the composting materials. SANITIZATION - The reduction of disease producing organisms below the level of health risks. SCREENING - The sifting of composting through a screen to remove large particles and contaminates. The final step to improve the consistency and quality of the end product. SEMI-MATURE COMPOST - The material is at the start of the curing stage. It can be reheated to approximately 20 degrees Fahrenheit above ambient temperature. The volume reduction of original materials is approximately 40-50%. Suitable for incorporation and/or application into soil avoiding plant root contact. SEPTAGE - The liquid and solid material pumped from a septic tank or cesspool during cleaning. SHREDDER - A powered mechanical device used to break waste material into smaller pieces. SIZE REDUCTION - The generic term for separation or breaking up of solid waste or other materials into smaller pieces through abrasion, thermal dissociation, tearing, screening, crushing, chipping, grinding, shearing, etc. The process makes waste easier to handle and increases surface area for composting. SLUDGE A solid residue of the waste water purification process. It is produced



by screening, sedimentation, filtering, pressing, bacterial digestion, chemical precipitation and oxidation. Primary sludge is produced by the sedimentation process and secondary sludge is the product of microbial digestion. SLURRY A thin watery mixture of fine insoluble material. SOIL AMENDMENT/SOIL CONDITIONER - A soil additive which stabilizes the soil, improves resistance to erosion, increases permeability to air, aids in water retention, improves texture, reduces surface crusting, eases cultivation or otherwise enhances soil quality. SOLID WASTE - The garbage, refuse and other discarded solid materials resulting from private, commercial, agricultural and community activities. SOURCE SEPARATION - The practice by primary waste generators (private and commercial) of dividing materials into various groupings (I.E. paper, plastic, glass, metal, food waste, yard waste, etc.) and placing them in separate containers for pickup by the waste hauler. The extent of separation varies with the marketing requirements of the disposal service and the community waste management program. STABILITY - The state or condition of composted material in which it can be safely stored or applied to the soil without adverse effects. The desired degree of stability in mature compost is one in which the readily compostable compounds are broken down and only the stabilization of the more resistant decompostable compounds remains to be accomplished. STABILIZATION - 1) A stage of composting following active decomposition. It is characterized by slow metabolic processes, lower heat production and the formation of humus. 2) A process which creates resistance to change. (See: CURING) STATIC PILE SYSTEM - A compost pile with or without a controlled air source that is not turned at all. THERMAL DEATH POINT - The required temperature to kill a specific pathogen. THERMAL DEATH TIME - The length of exposure time required to kill a specific pathogen at a specific temperature.



THERMOPHILIC STAGE - The stage in a composting process characterized by active bacteria which grow best in the high temperature range of 45 degrees Celsius to 75 degrees Celsius (113 degrees Fahrenheit to 167 degrees Fahrenheit). This stage is associated with a rapid rate of decomposition. The ideal temperature of a composting pile is considered to be 55 degrees Celsius (131 degrees Fahrenheit). At this temperature some mesophilic organisms are still active and contributed to the overall efficiency. TOPSOIL - The nutrient rich upper layer of soil consisting of various mixtures of sand, silt, clay and organic matter that supports plant growth. TOXICITY - An adverse biological effect due to toxins and other compounds. VERMICOMPOSTING - The biological degradation of organic matter from agricultural, urban and industrial sources occurring when earthworms feed on these materials. VIRGIN ORGANIC MATERIAL - The freshly harvested yard trimmings and tree prunings from the urban forest which are source separated and not commingled with other discarded materials. VOLATILIZATION - The gaseous loss of a substance to the atmosphere. WINDROW SYSTEM - The composting mixture is placed is elongated piles called windrows. These windrows may be left static to aerate naturally or may be turned mechanically with a front-end loader or specially designed equipment. In some cases, forced aeration from perforated pipes buried in the windrow provides oxygen for the aerobic process. YARD TRIMMINGS - The grass clippings, leaves, weeds, shrubs, and tree prunings less than six inches in diameter from residents and businesses.

Manual.Site Managers Handbook[1] · Chemical fertilizer production requires about 42 gallons of...

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Transcript of Manual.Site Managers Handbook[1] · Chemical fertilizer production requires about 42 gallons of...