Compost: Send Your Leaves to a MULCH Better Place

8/9/2019 Compost: Send Your Leaves to a MULCH Better Place

1/58

Send Your Leavesto a

MULCHBetter Place


2/58

Leaf CompostingA Guide for MunicipalitiesThe State of Connecticut Department of Environmental ProtectionLocal Assistance and Program Coordination UnitRecycling Program

Leslie Carothers, Commissioner

January 1989

Prepared byThe University of Connecticut Cooperative Extension Service

This document is printed on recycled paper.


3/58


4/58

STATE OF CONNECTICUTDEPARTMENT OF ENVIRONMENTAL PROTECTION

165 CAPITOL AVENUE HARTFORD, CONNECTICUT 06106

January, 1989Dear Local Chief Executive Officer:I am pleased to present you with this copy of Connecticuts leaf compostingmanual which has been developed in conjunction with the University ofConnecticut Cooperative Extension Service to assist municipalities in theplanning and implementation of community leaf composting programs.A major goal of the State of Connecticut is to protect its environment and thehealth of its people by minimizing solid waste generation where possible andproviding for the safe and adequate disposal of those solid wastes which aregenerated in the state~ In order to achieve this goal, the 1987 session of theGeneral Assembly passed Public Act 87-544 which mandates that a statewidesolid waste management plan be adopted to include a strategy to recycle notless than 25 percent of the solid waste generated in the state after January 1,1991. After that date, items designated in regulations promulgated by theDepartment of Environmental Protection for recycling cannot be accepted atlandfills or resource recovery facilities for permanent disposal. Among thesedesignated items is leaves.The Department recommends leaf composting as a relatively inexpensivemeans of recycling which can result in up to a 10 percent reduction in amunicipalitys waste stream. Simply defined, composting is a naturallyoccurring biological process in which organic material, such as leaves, is brokendown into a peat-like material by the action of microorganisms. The resultingcompost can then be used as a soil conditioner.Leaf composting has a great deal of potential for expanding.the statescomposting andrecyding effort. It will a~so result in reduced volumes ofwaste being incinerated or landfilled, avoided disposal costs, and reduction ofpossible environmental impacts - all with the production of a beneficial endproduct. I hope that this leaf composting manual will help your communityfulfill this potential.

Sincerely yours,

Leslie CarothersCommissioner


5/58


6/58

AcknowledgementsThis document is based upon material and recommendations gathered by theauthors through extensive site visits in New Jersey, New York, Massachusetts andConnecticut. State manuals from Massachusetts and New Jersey (Rutgers) provideda valuable source of information, as did the numerous consultants and researchers,with whom the authors spoke. Available scientific and industry literature was reviewedand a state-wide town level survey was conducted.The authors of the document are Roy F. Jeffrey, Community Development Agent,The University of Connecticut Cooperative Extension Service; John J. Kolega,

Agricultural Engineer, The University of Connecticut Department of Natural ResourcesManagement and Engineering; Robert L. Leonard, Resource Economist, TheUniversity of Connecticut Department of Agricultural Economics and Rural Sociology;and Robert Rynk, Extension Engineer, Department of Food Engineering, Universityof Massachusetts.

Special appreciation is given to Kathy Alexander and Lois Hager of the ConnecticutDepartment of Environmental Protection for their assistance in the preparation ofthis document.Appreciation is given to the review groups who so generously gave of their timeand offered constructive comments. Included are: Marilyn Altobello, CandaceBartholomew. Edmond Marrotte and Marilyn Moir of The University of Connecticut;Sumner Martinson and Michael Simpson, of the Massachusetts Department ofEnvironmental Quality and Engineering; F.V. Rossi, Director of Public Works in

Simsbury, Cf; Orris Yingling of Westport, CT; Tom Richard of Cornell University,NY; George B. Willson, Consultant, Laurel, MD, formerly with the AgriculturalResearch Service, USDA, Beltsville, MD; Beng Leong Ooi, President of OrganicRecycling. Inc., Valley Cottage, NY: Raymond Poincelot of Fairfield University, CT;Peter Battles, Town Planner of East Lyme, CT; Peg Hall, Recycling Coordinatorof Branford, CT; Paul Dion and John England of the Connecticut Department ofEnvironmental Protection.In addition, the authors would like to express appreciation to the Office ofRecycling. New Jersey Department of Environmental Protection/Department of Energyfor the use of their logo "Send Your Leaves to a Mulch Better Place."Finally, we wish to thank Rosalie Salisbury and Gall Brewster of the CooperativeExtension Service for their untiring secretarial work in preparing this document.

ii


7/58

Purpose of ManualTo a six-year old, a pile of leaves means a gleeful romp in the Autumn sun.To a public works director it can be a headache in the form one more load of soggy,solid waste to truck to an increasingly expensive disposal site. Although much ofwhat the Department of Environmental Protection does is oriented toward ensuring

the future of six-year-olds, the goal of this manu al is to help the public works directorand other municipal officials who are faced with disposing of tons and tons of leavesevery fall.Leaf composting is an easily managed and relatively inexpensive method ofrecycling. By decreasing the amount of solid waste which has to be sent to a landfillor incinerator, a well-run composting operation can reduce a municipalitys disposalcosts. At the same time, it can increase the visibility and viability of local recyclingefforts because it results in the production of a beneficial soil conditioner which canbe made available to residents and landscapers or utilized on municipal propertiesto enhance growth of plants by improving the general condition of the soil.The purpose of this manual is to facilitate the establishment of municipal-scaleleaf composting operations. It is intended to aid municipalities in planning, siting,designing and operating leaf composting facilities, and to identify those issues whichmust be addressed when applying to the Department of Environmental Protectionfor a composting permit.The manual describes several approaches to leaf composting and outlines thecircumstances in which each should be considered. The mair~ focus, however, is onthe "windrow and turn" method because this relatively simple technology oftenprovides the best b alance of efficiency and cost effectiveness.Hopefully, the six-year-olds joyful attitude will last a lifetime, and with thehelp of this manual, the public works director can focus on the aesthetics ratherthan on the tonnage of the falling leaves.

iii


8/58

Table of ContentsLelter from Cnmnlissioner ................................................. iAcknowledgements ....................................................... iiPurpose of Manual ................ : ...................................... iii

Planning A Leaf Compo sting OperationA. Volume .......................................................C.D.E.F.G.H.J.K.L.

Site Selection ...................................................Collection .....................................................End Use .......................................................Processing Method ...............................................Program Managemem ............................................Budget ........................................................ _ 9Process Management ............................................. 2Permits ....................................................... 2Education ..................................................... 2Schedule ...................................................... 2Additional Assistance ............................................. 3

II. Leaf CollectionA. Volume ....................................................... 4B. Municipal Collection Methods ......................................C. Scheduling Municipal Leaf Collection ................................ 5D. Public Education and Notification ................................... 5

llI. Technical InformationA. Basics of Composting ............................................. 8B. Composting Methods -- An Overview. ................................ 9Composting Leaves With Sewage Sludge .............................Composting Leaves With Other Plant Materials ........................Backyard Composting ...........................................C. Facility Siting and Design Considerations ..............................Area Requirements .............................................Ground and Surface Water Protection ...............................Site Layout and Preparation ......................................D Composting Operation ............................................ 14Annual Site Preparation .........................................Processing Equipment .......................................... 1 , tHandling Incoming Leaves ....................................... 15Leaf Wetting .................................................. I5Windrow Formation ............................................ 16Compost Process Monitoring ..................................... 16Windrow Turning ............................................. 17Leaf Cnring .................................................. 17Finished Product .............................................. 18Recmd Keeping ............................................... 18Conlin~ency PIm~ .............................................. 18E. Other Management Considerations ................................... 18Grass Clippings ............................................... 18Road Sah .................................................... 18


9/58

I V .

V.

Pesticides .................................................... 18Aspergillus Fumigatus .......................................... 18Lead ........................................................ 20F. End Use and Disposition of Leaf Compost .............................0General Characteristics .......................................... 20Market Opportunities ........................................... 20Distribution Channels ........................................... 20

BudgetingA. An Overview. ................................................. 22

R eferences & A ppendicesReferences....................................................... 30Appendix A. Troubleshooting Guide for Operating Windrows ....................1Appendix B, Weight, Volume and Bag Count Data ..............................2Appendix C. Leaf Collection Equipment and Approximate Prices (1988) ...........3Appendix D. Composting Processing Equipment and ApproximatePrices (1988) .............................................. 34Appendix E. Sample Windrow Temperature Data Sheet ..........................5Appendix F. Sample Leaf Volume Data Sheet ...................................6Appendix G, Capital Recovery Factor Values ....................................7Appendix H. Glossary ........................................................38

Figures andFigure 1.Figure 2.Figure 3.Figure 4.Figure 5,Figure 5a.Figure 5b.Figure 5c.Figure 6.Figure 7.Figure 8.Table 1.Table 2.Table 3.Table 4.Table 5.Table 6.Table 7.

TablesLeaf Collection Area Map ..........................................Windrow and Turn Profiles ........................................Aerated Static Pile Profile ..........................................Site Setback Distances ..............................................Sample Site Plan ..................................................Preliminary Site Layout Showing Windrow and Curing Areas ..........

5912141515

Compost Site Cut and Fill Recommendations for Site Grading ...........6Com post Windrow and C uring Areas Showing V ehicle T raffic Pattern . . . .6Windrow Spacing ..................................................18Temperature Measuremem Technique ................................8Windrow Turning Technique .......................................8Collection Options .................................................10Lea[ Compost Guidance Summary ...................................19Sample Windrow Temperature Data Sheet .............................24Worksheet for Estimating Municipal Costs of Collection ................4Worksheet for Estimating the Increase in Collection Costs Associatedwith a Shift from Disposal to Composting .........................6Worksheet for Estimating Municipal Costs of Lea[ Composting .......... 27Wo rksheet [or Summ arizing Annual Econo mic Benefits and Costsfrom Lea[ Composting ..........................................29


10/58

I. Planning aLeaf ComposungOperationII. LeafCollection


11/58


12/58

I. Planning A Leaf Composting OperationPlanning is the first task in establishing a leafcomposting facility. Several key decisions must be maderegarding leaf collection, processing and end use. TMssection outlines the items that local officials stmnldconsider.

A. VolumeEstimate the amount of leaves to be composted.Estimates generally run between 5-10% of the total solidwaste sneam. More specific estimates should be made

during the fall collection period by measuring truck loadscollected. If leaves are collected with other solid wastes,compare weekly volume dnring tbe rest of the year tothe volume of the fall collection.B. Site Selection

Given the estimated amount of leaves to be com posted,select an adequate site, the size of which should bedetermined by the volume of leaves collected. Approx-imately 3,500 to 12,000 cubic yards of leaves per yearcan be composted on one acre of land depending on themethod used. The compost site requires relatively flator gentl,v sloping land and moderately drained soil whichis not affected by seasonal high water. Site alterationsmay include grading, drainage control, security fencing,road improvements and provisions for fire protection.C. Collection

Determine the leaf collection systetn. Leaf collectioninvohes both municipal collection and independentItauling by residents, groundskeepers, and privately hiredhaulers. Independent hauling is common in suburbancommtmities with leaves brought to tile composting siteor a supervised collection station. A major decision iswhethel to ~ollect leaves in loose foml ot in bags.D. End Use

Determine Ibe end use of the composl since thisdecision will determine Ihe composting metlmd andcquipmenl Io be employed. Lea/compost is valuable asa naulch, soil amendment and topsoil snl)slilute.Potential users can include the town pinks, public worksdepaHmems, residents, landscapers and ntnser}men.Where high qualit3 compost is required, additional stepswill be uecessary for processing and screening.

E. Processing MethodChoose a composting method appropriate to the enduse. Four methods are available for composting leavesby themselves, of whiclt the windrow and turn methodappears thus far to be the most comm on and cost effective.

Passive LeaJ Piles involve placing the leaves in largepiles and letting them remain there until a usableproduct is developed, a minimum of 2-3 ..ears.Although it is a minimal management method, pilingshould not be considered a permanent disposaltechnique. Windrow and Turn requires the leaves to be placedin individual rows and turned frequently. A finalproduct can be achieved in one y ear or less. Aerated Static Pile reqnires the leaves to be placed ina large windrow through which air is pumped orpnlled. Information regarding use of this technologywith leaves is limited, but it appears that in order toachieve a final product leaves composted by themselvesrequire an estimated time of 4 to 6 months. Thereis extensive information regarding this method withcomposting sewage sludge. In-vessel composting is a fully enclosed "factory type"operation involving mechanical devices, controls and/

or forced aeration. The processing period may be asshort as 10 days, depending upon the mix of rawmaterials.F. Program M anagement

Choose a management structure. A compost site canbe m anaged in one of three ways: Municipally operated and managed: Involves tileassignment of municipal employees and equipmto the site. with a designated site manager. Municipally operated, privately managed: Inwflves theassignment of municipal employees and equipmentto the site but overall management of pile or windrow

buildingtm-ning, watering, etc. is ~emducted b} ap~ixate consultant or mam~gel who is paid a [lal feeo~ pmccntage of the tipping fee, nsual]} taRulaledon a cubic yardage basis. Normally, the priwue lirmis also responsible for marketing the final product. Privately operated and privately managed: Involvestotal s3stem operation by the private sector under


13/58


14/58

Time Schedule

Task SeasonDetermine leaf, volumeIdentil,y site end use andcnmposting methodDetermine personnelequipment needsBudgetDesign and permitsConstruct siteTrain personnelBegin operations

Fall Winter Spring ~ Summer Fall

Technical AssistanceDE P L ncal Assistan{e and ProgramCoordination UnitConnecticut Recycling ProgramRm 11.5, State Olfice Building165 C apitol AvenueHartl,ord, CT 06106 (203) 566-8722DEP Solid Waste Management Unit122 Wa~,hington StreetHartford. CT 06106 {203) 566-5817The Uni\cp, ity o[ C{mne{ti{ ut Cool)etutivvBox U-36, 1376 Storr, RosdStor>,, CI" 06269-4036 (203) 486-,1126

The U niversity of (2}nnecti{ utDepartment of, Natural Resour{cs Manag{mentand EngineeringBox U-87, 137 6 Stons RoadStorts, (7I 06269-4087 (203) 486-2840Conn((ti{ ut Agricultural EXl}etim(.nt Stzation123 Huntington Avenu{.Ntw Havcn, C-I" 0650"1 (203) 789-7272


15/58


16/58

C. S cheduling M unicipal Leaf CollectionLeaf collection is a seasonal operation beginning inmid-October and continuing through early December.

If an initial collection is made early in this period, asecond collection may be necessary. In addition, sometowns also make a spring collection of leaves and otheryard deb ris. A site for receiving leaves from independenthaulers should be. made available even if there is nota municipal collection in the spring. The leaves fromthe spring collection should be composted separatelyfrom the fall collection.D. Public E ducation and Notification

Regardless of the method of collection chosen, residentsand businesses must be educated on a regular basis aboutthe requirements for participation in the compostingprogram and the importance of keeping extraneousmaterial out of their leaf bags or piles. This type ofeducation can be incorporated into the ongoing publicityfor the overall recycling prbgram. In addition, thereshould be a special public notification for each leafcollection. The notification should include:

(1) A statement of the intent and community b enefitsof the composting program:( _ 9 ) A description of the intended uses of thecompost;(3 ) A statement that leaves must not containextraneous material such as branches, glass,metal, paper or household solid waste;(4) Instructions regarding the piling, or if bags areused, the type of bag and b ag closure to be used;(5) Instructions regarding the placement of leavesat the curb or in the street;(6) The dates when leaves will be collected indesignated districts and the locations and hoursof community collection stations and other drop-off locations.

Residents can be notified of the leaf collection datesby letter or announcements in the newspaper or on alocal radio station. If on-street parking is banned duringleaf collection, a notice should be posted on the streetat least 24 hours in advance, and parking bans shouldbe rotated within each community.A map, such as that in Figure 1, can be provided toresidents showing the designated leaf collection areas andthe temative dates for collection in each district. Sincethe rate of collection is dependent on weather conditions,however, any revisions to the dates need to be publicized.

Figure 1. Leaf C ollection A reas Designated by Districts(Source: South Windsor)

East Hartford

District Leaf Collection Start Date1 Oct. 292 Nov. 43 Nov. 124 Nov. 19


17/58

Table 1. Collection OptionsProcedure and/or Equipment Advantages Disadvantages

A. Bagged leaves Keeps leaves out of street and Cost of bags.prevents blowing leaves. Time required for debagging.Pickup not sensitive to weather. Plastic in compost must be avoided.Pickup at low cost without special-ized equipment.Instructions can be printed on bagsprovided by the town.1. Bag type:(a) Nonbiodegradableplastic.(b) Biodegradable andphotodegradableplastic.(c) Biodegradable paper.

2. Equipment and procedure.(a) Compactor truck.( i ) Empty baginto

compactor.

(if) Empty bag atcomposting site.(b) Dump truck.*

B. Loose leaves1. Location of piles:(a) Curb side.

(b) In street.

Lower cost of bag.Debris can be removed when bagis emptied.Little information is now availableon the use of these bags for leafcollection or how they break downduring composting.Convenience in bagging and great-er compaction than with plasticbags.

Large quan tity per load due tocompaction.Maximum opportunity forremoval of debris.Efficient dumping into windrows.Eliminates debagging operation atsite.Pickup may be quicker.No specialized equipment.

Costs and possible shortage of laborfor emptying bags.

Higher cost of bag.Extra effort in the distribution ofspecial bags.Shredding may be required.Possible increase in time needed forcomposting.High equipment costs unless thecompactor is used for otherpurposes.Inefficient use of compactor.

Inconvenience in emptying bagsand forming piles or windrows.Small quantity per load in absenceof compaction.

Avoid problems associated withleaves in the street.

Mo st convenient for collection inabsence of parked cars.

Raking of lea~es by collectioncrew is labor intensive, especiallywhen collection is by front endloader.Mo re extraneous material inleaves.Danger to children playing inleaves. Danger of fire from catalyt-ic converters.Either raking or repeated collec-

*Bags can be either hand loaded directly or piled into a front end loader and then lifted into the truck.


18/58

Table 1. Collection Options -- continuedProcedure and/or Equipment A dvantages D isadvantages

2. Vacuum leaf collector withdischarge into wire ormesh-covered box on dum ptruck or trailer.(a) Mounting options:(i) On trailer withdischarge intotruck.(ii) On front of truck(on hoist used forsnow plow).(iii) On trailer withleaf box.

(b) Drive options:(i) Belt.( i i ) On enginecrankshaft.(iii) Power take-off.

Catch basin cleaner.

4. Front end loader and dumptruck.

5. Front end loader andcompactor truck with chutefor receiving leaves.

Leaves are shredded to some degreeand are compacted, especially ifsomewhat damp.

Load one truck while another is intransit.

tion if cars are parked on the street.More extraneous material in leaves.Ineffective if excessively wet orfrozen.Dust if dry.Noise.Moderate expense for specializedequipment.Potential danger to operator andinconvenience from operation atrear of truck.Driver can see operator. Not generally available with beltdrive.Can be pulled with any type oftruck including one equipped forsnow plowing and sanding.Belt drive reduces vibration fromimpeller to engine which reducesmaintenance costs and increasesservice life.Lower initial costs.Intermediate cost relative to otheroptions.Large units (12 inch suction h6se)are fast and effective with su fficientsuction for collection of wet leaves.

Specialized equipment is optional.Effective with wet and/or slightlyfrozen leaves.Efficiency can be increased if frontend loader works with a small snowplow and final cleanup is with astreet sweeper.Same as in number 4 except thateffective capacity is much greaterwith a compactor.

Inconvenience in backing trailer tounload.Potential danger to operator andinconvenience from operation atthe rear of the truck.Higher initial cost.

Vibration from impeller increasesmaintenance costs and decreasesservice life.Intermediate cost relative to otheroptions.Small units (6-8 inch suction hose)are slow and clog in excessively wetor freezing conditions.Very high initial costs.Rather high maintenance costs.Noise.Leaves m ust be raked into the street.(A tractor-pulled rake can be usedonly in suburban areas.)Inefficient with dry leaves.

Same as in number 4.


19/58


20/58

III. TechnicalInformation


21/58


22/58

III. Technical InformationThis section contains detailed information about thecomposting process and is intended for those individualswho will design, manage and operate leaf compostingfacilities.

A . Basics of Com post ingComposting is a biological process in which micro-organisms break down organic materials, like leaves, intoa soil-like product called compost. The microorganismsare naturally present among the leaves. If nutrients,oxygen and moisture are present in the proper amounts,the microorganisms will heat the leaves up to I00-140degrees (F) and produce a near neutral (pH) product.This section briefly describes some of the principleswith which one should be familiar before developinga composting facility. The application of the principlesis explained in subsequent sections.

Microorganisms: Decomposition is conducted primar-ily by microscopic organisms naturally present in leafwaste, including bacteria, actinomycetes, and fungi.These microorganisms grow rapidly on the organicmaterial, using it as a source of food. Heat, carbondioxide, water vapor, and compost are produced inthe process. Nutrients: The availability of carbon and nitrogen isa limiting factor in the composting process. Themicroorganisms need nitrogen for protein, bodybuilding and population growth, and carbon is theirenergy source. In addition, efficient compostingrequires carbon and nitrogen to be present in the properbalaoce.The optimum range of the carbon to nitrogen (C:N)latio is from 20:1 to 30:1. Tile more tile C:N ratiodeviates from this range, the slower the decompositionprocess becomes. With a ratio of greater than 40 to1, nitrogen represents a limiting factor and the reactionrate slows. With a C:N ratio lower than 15 to 1, excessnitrogen is driven off as ammonia. While this loss ofoitrogen is oot detrimental to the process of decom-

position, it lowers the nutrient value of the compostproduct.The C:N ratio in leaves tends to range between 60:1to 80:1. thus, leaf composting is generally slower thanmost composting applicatioos. By adding nitrogen-rich materials, such as seaweed or grass clippings, theC:N ratio will be reduced and improved. Oxygen: An adequate supply of air is essential to the

maintenance of efficient composting. Aerobes, theorganisms primarily responsible for the rapid decom-position of organic material, require oxygen to convertorganic waste to compost. Normal air is about 21%oxygen. If the oxygen content falls below the optimumlevel of 5%, these organisms begin to die off and thecomposting process is taken over by anaerobes,organisms which do not require oxygen. They operatemuch less efficiently and can cause severe odorproblems.

Temperature: Temperature is a key environmentalfactor affecting biological activity and should bemonitored frequently. The metabolism of the microor-ganisms present in the leaves results in a naturaltemperature increase. Due to the insulating effect ofthe leaf compost pile, the temperature achieved in thepile affects the makeup of the microbial population.The optimum temperature range is between 100 and140 degrees F.

Two categories of microorganisms are active inaerobic composting. At temperatures above freezing,mesophilic organisms become active. As a result of theiractivity, the temperature within the compost pileincreases. At temperatures in excess of l l0 degrees F,thermophilic organisms become active, increasing therate of decomposition. As the temperature approaches140 degrees F, the rate of decomposition begins todecline rapidly as organisms begin to die off or becomedormant. Moisture: In leaf composting, the optimal moisturecontent is 40% to 60%, by weight, or about theconsistency of a wrung-out sponge. Moisture isrequired to dissolve the nutrients utilized by microor-ganisms as well as to provide a suitable environmentfor bacterial population growth. A moisture contentbelow 40% limits the availability of nutrients and limitsbacterial population expansion. When the moisturecontent exceeds 60%, the flow of ox,vgen is inhibitedand anaerobic conditions begin to develop. Leavesnsually require additional water at the start of the

process. pH: During tile composting process, the material willbecome slightly acidic and then return to near neutralconditions as stability is approached. Decompositionis most efficient with a pH of between 6.0 and 8.0.If the pH is too high, nitrogen is driven off as am monia.As the pH drops below 6.0, the microorganisms beginto die off and the decomposition slows.

8


23/58

The pH level of the comp ost pile partially determinesthe type of organisms available to the decompositionprocess.Bacteria are most successful as decomposers whenthe pH is between 6.0 and 7.3. Fungi have an op timumrange between 5.5 and 8.0. Normally, operating leafcompost systems should not present a pH (acidic)problem. Should such an occurrence develop, theaddition of lime may be necessary. To minimize thispossibility, keep the pile in an aerobic state. Thenormal pH range for finished leaf compost is neutralto slightly alkaline (7-7.:3).

Particle Size: The m icroorganisms act on the surfaceof the composting materials. Smaller particles (the sizeof a quarter or smaller) have greater surface area andbreak down more quickly. However, extremely smallparticles limit air flow through the materials so somecompromise is required. Time: The time required to transform leaves intofinished compost v aries considerably, depending on theprocess utilized, from 10 days to 3 years. Frequentaeration, fine particle size and the proper ratio of carbo nto nitrogen speed the process. The process is slowedby low temperatures and materials with a highproportion of cellulose and lignin.

B. Composting Methods -- An OverviewSelection of the methodology best suited for thecommunity will depend upon a variety of factors,including marketing options, availability, site con-straints, and equipment opportunities. Additionally, the

availability and usefulness of other organic wastes mayinfluence the decision-making process within eachmunicipality. The windrow and turn method has beenused most often for leaf composting. A leaf compost

guidance summary can be found in Table 2. Passive Lea[ P iles: Leaves are depo si ted in piles ranginin height from 9 to 20 feet and are left undisturbefor a minimum of two to three years. Leaf piles th

are too small (less than 6 feet high) should b e comb ineAn optional measure is to turn and aerate the leaf pin the early spring or late fall. Although procemanagement is minimal, the leaf piles shouldmaintained to avoid an unsightly appearance ashould be com bined after there is a noticeable volumreduction from the initial leaf pile size. Odor maya problem when these piles are disturbed as anaerobconditions may exist in the oxygen starved centerthe pile, so wind directions should be considered befowork on the p iles is undertaken. Comp ost consistenGfor end use is fair, as it may retain clumpsuncomposted leaves. Windrow and Turn: Leaves are deposited on acompacted pad to form a triangular shaped windrow(Figure 2a) measuring 10 to 20 feet at the base witha height of 6 to 12 feet or higher. The windrow lengthcan be up to several hundred feet long or as long asthe site allows. In this process, the windrows are turnedperiodically with a front end bucket loader or a specialturning machine and water is added as needed. Thefrequency of windrow turning is determined by thetemperature and moisture content of the windrow.Windrows are combined as they shrink in size. Theleaves compost through the winter and spring, cureover the summer and are available for end use by thenext collection season. The finished compost can be

removed from the composting site to make room forincoming leaves. The consistency of compost for enduse is good as periodic turning will result in fewerclumps of undecomposed leaves.

Figure 2 . Windrow an d Turn Prof i le sa. Front End Loader Formation b. Windrow Turning Machine Formation


24/58

Table 2. Leaf Compost Guidance Summary.Parameter MethodLeaf Pile Windrow and Turn Forced Aeration1. Site information.Size: cubic yards 8,000-12,000leaves/acreSurface Earth pad

Grade 2% slope (rain)DrainageSubsurface ModerateSurface

2. Suggested separationdistances (in feet) fromcompost site.To residential andbusiness complexes

Satisfy acceptable waterquality criteria for dis-charge (or contain on siteif needed). Divert surfacewater from p iles.

3,500-8,000 5,000-10,000Earth pad (paved surfaceacceptable)2% slope (min)

Earth or paved2% slope (min)

Moderate ModerateSatisfy acceptable waterquality criteria for dis-charge ( or contain on siteif needed). Divert surfacewater from windrows.

Satisfy acceptable waterquality criteria for dis-charge (or contain on site ifneeded). Divert surfacewater from aeratedwindrows.

200-250 200-250 200-250From adjacent property 100lineFrom a surface water 100bodyFrom glound surface 5*to bedrockFrom ground surface to 5 *seasonal high watertable (highest seasonatlevel)Com post process time 9-3 years

Not applicableCan be high at time of ini-tial pile disturbance.

~ 4. Curing time (followingi compost process)5. Odor generation

100 100lO0 100

Varies with frequency ofturning windrows 6-12months1 month (min)

4-6 months

month (min)Some odor potential when Minimal problem if thepile is first disturbed; prop- system is properly de-er management will reduce signed, installed andor eliminate this potential; operated.decreases with pile turningfrequency.

*Current S tate of Conn ecticut practice followed for siting solid waste land disposal facilities.

10


25/58

Table 2. Leaf Compost Guidance Summary continued.i Parameter Method

Leaf Pile Windrow an d Tu r n Forced Aeration6. Equipment needs Front end loader daily Front end loader daily Front end loader, tubduring leaf collection during leaf collection mill grinder, blowerperiod, period and when win- type fan, temperaturedrows are turned, and timer switch con-

7. Water supply

Three or 4 foot stem trois, plastic pipingtype thermometer. For (both solid and perfo-large leaf composting rated lengths needed), 3facilities, evaluate the or 4 foot stem typeuse of specialized me- thermometer.Adequatechanical equipment for electrical capacity. O p-turning windrows, tional leaf shredder.Required for fire con-trol, wetting of leaves;can use water hose or aportable water tanksource having waterspray capability. Up to45 gals/cu yd. Largeoperations may requireon-site water.

8. Operational

9. Comments

Required for fire con-trol and wetting ofleaves.Up to45 gals/cu yd.

Nothing done to leafpiles; may combine leafpiles after initial pileshrinkage. Maintainheight of at least 6 feet.

End product qualitymay limit marketablity;shredding will improveappearance.

Combine w indrowsafter pile shrinkage oc-curs (1 or 2 monthsafter their formation).Turn windrows as in-dicated by temp eratureand m oisture data.

Acceptable compostquality; screening ofcompost will give amore uniform product.

Required for initialwetting of leaves (seewindxow ) and for firecontrol.Up to 45 gals/cu yd.

Blow air through thepile. An organic mate-rial such as woodchips, sawdust or com-post is used as a pilecover for insulation.The frequency andtime of aeration is bytimer switch or temper-ature controlled.The field experimentdata available for thisapplication is rather li-mited. Method hasbeen used successfullywhere leaves have beencomposted with sewagesludge (Greenwich,CT).

11


26/58

Use of specialized windrow-turning machinesimproves aeration, resulting in shorter time require-ments for composting. The turning machine is eitherself-propelled or machine driven. If machine driven,it is important that the drive method selected beproperly matched to the machine.

With windrow-machine turning, the machineselected limits the windrow height to 5 to 7 feet.Windrow width varies from 14 to 18 feet to give atrapezoidal shaped pile, (Figure 2b). Aerated Static Pile: The windrow configuration issimilar to that described for windrow and turn except

that the windrow is stationary. (static pile) and has abase of wood chips or some other porous material.Since the leaves are not turned in this process, it isparticularly important thal non-compostable materialsare removed before windrow formation. The leaves are

also put through a tub grinder or shredder beforeforming the windrow. A perforated plastic pipe isplaced over or in the base material and air is forcedthrough the pipe into leaves using an air blower (Figure3). After the windrow is formed, a t"-6" layer ofcompost, wood chips, sawdust or an equivalent porousmaterial is placed over the pile to help retain processheat, moisture and odor. In order to manage windrowtemperature the air movement is controlled either bya timer switch or manually. Experience with thismethod for composting leaves is limited. It is generallyused in sewage sludge composting.

In-vessel Composting: In-vessel composting encom-passes a variety of systems involving mechanicalagitation, forced aeration and enclosure within abuilding. These systems are designed and supplied byconsultants or commercial suppliers. They are

Figure 3. A erated Static Pile Profile

Note: Piping size and su bstrale thickness not inrelative proportion to pile heigh~ and width.lanlc Blanket 6"

ip e [4")

12


27/58

generally not economically feasible for compostingleaves alone, but may be ap propriate if sludge disposalis an issue. The advantages include fast processing,avoidance of weather problems and better process andodor control.Composting Leaves w ith Sewage Sludge: Leaves can beadded to sewage sludge to provide a bulking agent forthe sludge. The leaves provide a carbon nutrient sourceand increase the number of voids (air spaces) to improveair passage for process temperature control, addition ofoxygen, and removal of excess moisture. Sewage sludgecomposting involves environmental and health concernsfar beyond those associated with leaf composting andrequires additional approvals and/or permits from DEP.It should be noted, however, that using leaves in thisway could serve as an alternative to the separatecomposting of leaves. Composting leaves with sewagesludge would normally be an option with the forced

aeration and in-vessel methods. There may be othermaterials currently b eing comp osted for which leaves canserve as a bulking agent.Com posting Leav es With Other Plant M aterials: Leavescan be composted with other forms of plant material,such as seaweed or grass clippings. One advantage ofsuch a composting practice is an improvement in thecarbon to nitrogen ratio (C:N). The fresh plant materialprovides the nitrogen source and results in a fastercomposting rate. Experimentation is advised beforeundertaking this method of composting on a large scalebecause high nitrogen levels will require much morefrequent turning to prevent odor problems.Backyard Composting: Backyard composting involvesthe composting of leaves and other yard wastes on a smallscale within the confines of ones own property. Thismethod is particularly appropriate for areas where theresidences are located on one-half acre plots or larger.Backyard composting should be encouraged becauseresidents benefit from readily available leaf compost andthe municipality benefits by avoiding the cost of handlingand processing the leaves. For further informationregarding backyard composting, contact the local officeof The University of Connecticut Cooperative ExtensionService.C. Facil ity Sit ing and D esign Con siderat ionsArea RequirementsProcessing Sites: The facility is sized according to theyearly seasonal volume of leaves to be handled, takinginto consideration the method of leaf collection and thecomposting method employed. A good leaf volumeestimate can be made from records of the number of truckloads of leaves hauled. For this purpose, one ton of leavesis taken to be the equivalent of approximately four cubic

yards of leaves. Additional information is provided inAppendix B. In the absence of such information, a leafvolume of six percent of the total annual solid wastevolume can be used. Space requirements vary accordingto the composting method, ranging from 3,500 to 12,000cubic yards of leaves per acre. For example, a suggestedguideline for a windrow and turn facility is one acrefor each 6,000 cubic yard of leaves. Additional space isrequired for the compost storage and site buffer areas.Compost Storage Area: For the windrow and turnmethod, the storage area for finished compost shouldbe an additional 15 percent the size of the windrowcomposting area. Compost will need to be kept in thestorage area for a minimum of one month while it cures.Bullet Area: Consider the impact of potential odor, on-site operational noise and visual appearance on thesurrounding neighborhood when siting a compostfacility. Minimum suggested separation distances of thecomp ost processing and storage site are 200-250 feet fromoccupied buildings and at least 100 feet from adjacentproperty lines. Existing trees and landscaping may beused to improve aesthetics by screening the site frompublic view and to reduce equipment noise. The potentialimpacts of composting odor and traffic flow on adjacentareas should also be considered.Ground and Surface Water Protection: A minimum of5 feet should be maintained between the base of thedeposited leaves and the maximum high water table orbedrock. This recommendation is based upon the currentState of Connecticut practice for siting solid waste landdisposal facilities but may be modified in accordance withspecific site conditions such as soil permeability andhydrologic setting. High groundwater can cause severeproblems for equipment movement, especially in the latewinter and spring months when piles must be turned.

The compost processing and storage site should beat least 100 feet from a surface water body such as abrook, pond or stream. Facilities must be sited inaccordance with the Connecticut Inland-Wetlands andWater Courses Act and the Connecticut Sedimentationand Erosion Control Act.Site Layout and Preparation: Once an appropriate sitehas been chosen, a site plan needs to be p repared. Samplediagrams are found in Figures 4 and 5.Compost Pad: This is the surface where compostingoccurs. It should be constructed of well-drained materialsand be designed for heavy equipment use in all seasons.Windrow length should p~rallel the slope. To preventruts from forming a paved surface can be used as a pad.Roads: Roads should be laid out to provide easy accessfor the public, leaf hauling vehicles and fire protection

13


28/58

equipment. The road surface should be able to sustainthe load of the vehicles indicated, and be functional inall types of weather conditions.Drainage: Locate the site on mo derately to well-drainedsoil. Excessively well-drained soils should be avoided,unless site modifications are m ade. Surface water shouldbe diverted away from the compost process site andstorage area using a diversion ditch, an interceptor berm(baled hay or other m eans) or an interceptor drain. Anysurface or subsurface discharge away from the site mustbe made in an environmentally safe and acceptablemann er. Design water diversions and discharge systemsfor a 25-year rainstorm. Slopes should be graded at 2-3 percent (2-3 foot drop in 100 feet), to assist in surfacewater removal from the pad. Be sure not to exceed a5 percent grade.Water: A source of wa ter is needed for we tting the leaves,and provision must be made for fire protection. Wherea water source such as a pond or a hyd rant is not available,a water tank vehicle can be used. For very dry, leaves,approx imately 45 gallons of water are required for eachcubic yard of leaves. For large operations, an on-site watersource may be necessar).Site Clearing: Clear the site to provide enough space forroads, compost processing, storage of compost, and forfire protection. Before clearing, consider the need for abuffer zone and visual screening.Signs: Post a sign at the entrance to the facility identifyingthe facility and indicating the hours of operation.Directional signs will be needed for traffic control. Theleaf receiving area should be identified. Signs may alsobe needed to clarify the fact that the facility is for leavesonly, thereby minimizing the addition of contaminants.Security: Control access roads so that illegal dumpingor vandalism does not occur.Please see Table 2 for a summ ary of facility siting anddesign considerations.D . Compost ing Operat ion

The following section focuses on tile windrow-and-turn method of composting leaves. In most settings, thismethod will strike a good balance between processefficiency and operational simplicity. Details about theoperation of the other methods mentioned here can befound in the references or from consnltants engaged todesign a composting system. In addition, a trouble-shooting guide for operating ~ windrow and turn facilityis included as Appendix A.Annual Site Preparation: Prior to the start of the leafcollection season, regrade the site as needed to maintaina 2-3 percent slope and to maxim ize run-off and minimize

Figure 4. Site Setback D istances

Note: Depending on site constraints such as propertylines, buildings and surface water, availableacreage for composting will vary. Area losscould be significant.

ponding of surface water. Bring in fill as needeMaintain the drainage system components such asubsurface drains or diversion ditches.Review and prepare the site to ensure good vehicloperation conditions.Check the availability and method for handling watto wet leaves. If there is no water at the site, a watehauling tank vehicle and a mechanism for spraying water on the leaves will be needed.

Processing Equipment: Equipment needs and preferen-ces will vary with each community. Use of existingequipment is encouraged but this may not always resultin tile most efficient operation. In some instances, it maybe possible to share specialized equipment (i.e., a sieveor shredder) with nearby towns.The basic piece ol equipment needed for any type ofleaf composting operation is the front end bucket loader.It is used daily at the site during the leaf collection season.With windrow-and-turn operations the loader or otherturning equipment must be available for the remainder

14


29/58

Figure 5a. Preliminary Site Layout Showing Windrowand Curing Areas, Proposed StormwaterManagement System and Access Road.Quali~ Engineering, Division of Solid Waste.

PROPOSEDRECHARGE BAS IN

of the year for w indrow turning and reconstruction whenneeded. For large operations, specialized turning andmixing equipment may be feasible. Informationregarding compost processing equipment is found inAppendix D.For compost process temperature monitoring, a 3-4foot pointed stem-type thermometer capable of readingbetween 0 to 200 degrees F is needed. A spare thermometeris recommended to confirm temperature calibrations.Screens, shredders or tub grinders are optional but canbe used to reduce volume, obtain compost uniformityand remove unwanted materials. Shredding o[ leaves toreduce leaf size normally is not needed at the initial stageas the leaves are adequately reduced in size through thephysical process of moving and turning during collectipnand composting. Such shredding, however, may ass*stthe compost process if moisture levels are low by reducingthe free air space. At the end of the composting/curing

process, it may be appropriate to screen the compost toremove large clumps and woody material. This createsa more marketable product with a consistent level ofappearance.Handling Incoming Leaves: Incoming leaves can bebrought directly to the leaf processing area or to areceiving (staging) area for later transfer to the leafcompost pad. Compacted leaves brought directly to thecompost pad must be loosened and fluffed for properaeration. If citizens are allowed to bring leaves to thesite, a separate drop-off point should be provided fordebagging, traffic control and safety considerations. Sitesupervision is required during this period for qualitycontrol and the recording of leaf volume delivered tothe site.Although a leaf receiving area adds another step tothe site operation it allows flexibility in scheduling thestart of the leaf composting process and in schedulingthe debagging o f leaves. The leaves should be transferredto the windrows within a couple of days to prevent thecompost process from starting in the receiving area.

Unless biodegradable bags are used, leaves should bedebagged before they are placed in the windrow.Debaggers should work on the face of the pile -- notfrom the ends -- so that more people can work on onepile at the same time. Simple hand tearing of bags seemsto be as efficient as other methods. Empty bags shouldbe removed immediately and placed in receptacles so theydo not end up in the windrows. If a staging area is used,leaves should be removed fro*n the debagging areaimmediately after opening to make space for thedebaggers to work.Leaf Wetting: Incoming lea,.es should be checked formoisture. A "hand squeeze" test is adequate. If no wateroozes from a handful of squeezed leaves, the leaves should

15


30/58

Figure 5b. Comp ost Si te Cut and Fi l l Recommendationfor Site Grading.

Figure 5c. Compost Windrow and Curing AreasShowing Vehicle Traffic Pattern.Source: Massachusetts Department of EnvironmentalQuality, of Engineering, Division of Solid t\as*e.

be wetted before or while they are being placed in thewindrow. Leaves can be wetted using a hose connectedto the water source or by using a pum p-spray mechanismattached to a po rtable water tank.During the early stages of composting, leaves mustbe mixed during wetting, otherwise the water will runoff the pile surface instead of penetrating the windrow.Over-watering is normally not a problem as excess waterwill drain off. Once the leaves start to break down,watering can be done after turning without problems.With specialized windrow-machine turning, the leavesare wetted after the first or second turning using a fireor stick hose. The initial leaf turning breaks up the leavesto improv e their water retention capab ility. Leaves shouldnot be over-watered in this process. If pile moisturemeasurements can be made, aim for a pile moisturecontent of about 45-50 percent.

Windrow Formation: The windrow should be at leastsix feet high with a bottom width of about 10 to 14 feet.(See Figure 2). If a greater height is used, the windrowswill require more frequent turning.Start the first windrow 20 feet from the edge of thecomposting pad. Leave two feet between the first twowindrows and a 20-foot space between pairs of windrows.Windrows should run in the direction of the slope toreduce any tendency for ponding. (Figure 6).After the windrows have been reduced to almost one-half of the initial size (about 1 to 2 months after windrowformation), each pair of windrows is combined into asingle windrow.During specialized machine turning of the windrow,leaves will fall into the vacant aisle. It will be necessaryperiodically to gather these leaves and place them in thewindrow. Depending on how the windrows are spaced,windrows are combined 15 to 25 days after the start ofthe composting process.Windrow layout should address fire protectionconcerns as needed. Although a leaf windrow fire is anunlikely occurrence, the layout of the windrows and thesite conditions should provide access for fire fightingequipment (fire lanes or fire hose and water hydrant):

Compost Process Monitoring: Windrow temperaturemeasurements should be made and recorded at least twicea week to monitor the compost process and to determinewhen it is complete (see Table 3). Other data to recordat that time are the ambient air temperature, weatherconditions, odor (if detected), pile moisture conditionsand site observations. There should be at least threetemperature measurements per 100 feet of windrow takenat the lower third of the leaf compost pile using a 3foot stem-type thermom eter (figure 7).

16


31/58

Time, odor and temperature are indicators of whenthe compost process is comp lete. After a period of about6 months begin checking for compost stabilization asfollows. Place a sample of the compost in a plastic bag,seal it, store at room temperature 24 to 48 hours, andthen open it. If there is no significant odor, the processis complete and the compost is ready for movement tothe storage area for curing. Temperature recovery afterwindrow turning is another sign of stabilization. If thereis no odor nor increase in temperature in the windrowoccurring within seven days, the compost is stable andready for the curing stage.Windrow Turning: Windrows should be turned whenthe compost pile temperature drops to 100 degrees F orif the temperature exceeds 140 degrees F. The windrow smay require turning if other process problems develop,such as odor or excess m oisture at the base of the windrow.When turning, the leaves should be lifted high with abucket and allowed to cascade to a new location(figure 8). The next turning should be done in theopposite direction. In all cases, operators should attemptto get those leaves on the bottom of the windrows tothe top of the new windrows. At the time of turning,

check and remove contaminants. Common ones includeplastic, bottles or containers, rocks or stones, automotivehubcaps, tennis balls, and miscellaneous bulks materialsIf moisture has to be added to the windrow, try toschedule the turning operation to coincide with rain orsnow to avoid having to pump or deliver water.

At compost sites near residential areas, schedulewindrow turning to avoid noise and/or odor complaintsTry to select a time when the wind is blowing awayfrom neighboring buildings. A wind sock erected at thesite can be used as a wind direction indicator. Choosea time of day when most people are likely to be awayor inside their buildings.Leaf Curing: After the leaves have been composted, abrief curing period is needed to complete biologicastabilization. This can be done at the compost pad ora separate bulk storage area. The compost is left as isfor at least one month for curing before use. At this po int,compost can be made into large piles as opposed towindrows thereby taking up less space.

Figure 6. Windrow (WR) Spacing

W R5

17


32/58

Finished Product: The finished compost can b e screenedto break up clumps to provide product uniformit,v andimproved appearance. An analysis of compo st for selectedchemical constituents, such as nitrogen, phosphorus andpotassium, lead, cadmium and pH, should be made.Municipalities may obtain appropriate analysis of tbecompost through the Connecticut Agricultural Exper-iment Station in New Haven.Record Keeping: The importance of good record keepingcannot be over-empbasized. Records should be main-rained on the quantity of leaves received, processtemperature and moisture, operating costs, the cbemicalcomposition of the compost produced and the quantityof compost shipped. Such information is useful inassessing the efficiency of the operation and developinga cost/benefit analysis. Regular observations concerningodor, noise, and dust are important in evaluatingcomments received by local and/or state officials. Thesite observation recorded for the day that the complaintwas reported might serve to substantiate whether or notthe problem could be associated with the leaf compostingprocess. Appendices E and F may be copied out of thismanual for use by the site manager.Contingency Plan: There should be an alternativearrangement available in the event that leaves cannotbe composted due to unforeseen circumstances; e.g.,equipment failure or natural disaster.E. Other Management ConsiderationsGrass Clippings: Grass clippings have a relatively highercontent of nitrogen than leaves. In some instances,however, grass may have concentrations of herbicides(weed killers) used in normal lawn maintenanceprograms. Once applied to turf the herbicide may takea few weeks o r months to deg rade to a relatively harmlessstate. Ongoing research at Rutgers University is expectedto provide additional information on this topic.Road Sal t: Road salt used in ice and snow removal hasnot been found to be a problem with regard to highconcentratiotas in leaves used for comp osting. Generally,any concentration of salt that may be deposited on leaves(during an early fall snowstorm or over the winter forthose leaves picked up in spring) becomes diluted witha larger amount of leaves that have not been in contactwith road salt.Pesticides: Pesticides used on trees are normally co nfinedto a few insecticides and possibly some fungicides. Ina norm al 3ear, only a few trees will be selectively sprayedand in most instances will be treated early in tbe growingseason (June-July). During those years of high insectinfestation (e.g., gypsy moth caterpillars), a moreintensive spraying program may be necessary. However,

Figure 7. Temperature Measurement Technique

1/ 3 H e i g h t

F igu r e 8. W in d r ow Tu r n in g for A e r ation an d M ixin gof LeavesLift leaves high with bucket loader and let leaves fallto new location to create a cascading (m ixing) effect.

Note: The principle of the mixing technique is to movethe top of the windrow to the bottom of thewindrow being formed, mixing the leaves wellduring this process.

even in this case treatment will be completed early inthe season (May-June), and by the time leaf fall occurs,the pesticides will be significantly degraded.Aspergillus [umigatus: A fungus spore Aspergillus]umigatus, may be produced by the composting processespecially when wood chips are used as a bulking agentin sewage sludge composting. This fungus may be a causeof lung infections in susceptible humans. Little evidenceexists to demonstrate that this is a concern with leaf corn-

18


33/58

Table 3. Sample Windrow Temperature Data SheetData collected by: ~. ~~. CtgM~"/" Year: /~q Month:

Weather Information (Sunny, rain, etc.)Wind direction (from Northeast, South, etc.)Air Temperature: oF 36 ~" Time of dav:Site Observation Comments (Water ponding, dust, etc.) l/.,/a~, ~/~tt. gC)/~,a/~o ~,.~

Windrow Moisture ("Hand squeeze" test observation) circle item: Needs moisture ~ ExcessOdor (circle item): ~ Minimal Strong

Temperature Observation, Findrow temperaturemeasurement location:

Diagram

Windrow O bservation (See Sketch Below)

Actions Tak en (turneO windrow, graded, etc.):

19


34/58

posting operations. However, municipal compost sitesshould not be established in close proximity to bospitalsor nursing homes. People with diseases causing imnrunesuppression (including arthritis) should uot work nea~compost. In addition, people taking drugs that suppressthe immune system, like c~,closporiu, should not workwith compost.Lea& Lead is sometimes fonnd in finished compostproducts, particularly in sludge composting. Very limiteddata exist concerniug concentrations that nray be exp ectedto be found in compost produced only from leaves, andthere appears to be no published data compariug leadlevels in leaves by source (e.g. street trees in an urbansetting vs. yard trees in low density suburban settings).Research in N ew Jersey indicates that relatively low levelsshould be expected.F. End Use and Disposit ion of Leaf Com postGeneral Characteristics: Leaf compost is a soil-likematerial valued primarily as a soil amendment. Thenutrient content of leaf compost is usually too low toconsider it as a fertilizer. Generally, leaf compost pilesinclude clumps of uncomposted leaves, branches andother foreign materials which, if not screened out,significantly decrease the value of the compost. Screeningor shredding increases the value of the com post.Market Opportunities: In determining market opportun-ities the following procedure sbould be followed: Inventory possible markets. Identify their specifications. Identify their capacity to absorb the compost. Thisshould include the amount used each year, theseasonality of use, and projections for long-term usage. Identify their shipping and delivery requirements. Identify revenue potentials of target markets.

There are a number of market opportunities for leafcompost. They include:Municipalities:Continual and extensive need forcompost type products as soil amendments and mulch.Screening the compost will make the product usable ona larger variety of jobs.

Landscaping htdustry: Continual and extensive need forcompost-type products as soil amendments and mulch.The compost sbould be screened to remove unwantedmaterial and be of consistent appearance.Greenkouse/Nursery: Large demand for co~npost if itis of consisteudy good quali~y based upon physicalchemical characteristics. The compost must be screenedto remove unwauted materials and present a cousistentappearance. Leaf compost cau comprise up to 90% oftile potting soil mix for eilher bedding plants or nmser~,plants. Cbemical analysis of N. P, K and pH is neededto accommodate tile nutrient needs of tbe plant.Home Grounds Gardening: Useful as an amendment togarden sob and as mulch around landscape plantings.Does not require screening.Agriculture: Agricultural producers annually addorganic matter to improve soil conditions and cropproduction. Corapost is useful if conveniently and readilyavailable in large enough quantities. Does not requirescreening.Distribution Channels: Product movement off-site willbe determined by the availability of users and distributionoptions. Distribution channels include:Municipal: Equipment can be used to move compostoff-site to road jobs, school landscaping, etc.Giveaway: Commonly used: residents pick-up at site.Wholesale to Distributors: Several large compostmarketing companies operate in the northeast and canhandle bulk or retail distribution of high qualitcompost. While tbis option will not provide muchincome to the compost producer, it will save time andmanagement required for distribution.Bulk Sales: Sold to large-scale users (landscapers,greenhouse, etc.). Charge assessed on yardage or tonnagebasis. Product can be delivered or picked up at the site.Retail: Sold directly to public, usually on a volume orvehicle basis. Usually unbagged. Requires managementof funds at site for each sale. If considering sale of b aggedcompost, a marketing study is recommended.

2O


35/58


36/58

IV. Budgeting


37/58


38/58

IV. BudgetingBudgeting is a systematic procedure for estimatingcosts, revenues and other benefits. This section providesa broad overview of budgeting and sample worksheetsto determine tbe cost/benefit analysis of leaf com posting.

A. An OverviewTables 4 through 7 are worksheets to be used inestimating the costs of equipment, labor and suppliesneeded for leaf collection and composting. Tables 5 and7 also include procedures for estimating benefits snchas the avoided cost of incinerating or landfilling leavesand the value of compost a\ailable for use by themunicipality and by residents. Several copies of theworksheets may be needed in exploring and evaluatingalternatives and in organizing information about theparticular alternative selected for implementation. Theworksheets provide a general outline for estimatingmunicipal and non-municipal costs and benefits andshould be modified to meet the needs of a particulartown or group of towns if a regional project is underconsideration.A town with an established procedure for keepingleaves separate from other solid wastes and with nointerest in considering ahernative leaf collection policiesand procedures may not need Tables 4 and 5. A ny changein collection costs associated with a shift from disposal

to composting would probably be directly related to thedifference in hauling distances and could be directlyestimated and entered in Part B1 of Table 7.Towns now collecting leaves in combination withother solid wastes should carefully explore and evaluatealternative leaf collection policies and techniques priorto investing in specialized equipment. Table 4 providesan outline for estimating municipal costs of separate leafcollection with alternative combinations of equipmentand operating procedures. General data on leaf weiglrts,volumes mad bag counts are given in Appendix B.Information on leaf collection techniques and equipmentis shown in Table 1 and Appendix C. Each town willneed additional information directly relevant to local

conditim~s. Planners should visit nearb,v towns v,,itbsimilm conditions which have bad experience with leafcollection.Table 5 outlines a procedure for estimating themunicipal and non-municipal change in leaf collectioncosts associated with a shift from disposal to composting.It is broad ira scope and accounts for independent hauling

and municipal contractors as well as leaf collection bymunicipal employees.Because Table 5 includes items that vary from townto town, estimating procedures consistent with localpolicies and practices are required. Bag costs, for exam ple,have generally been a non-municipal expense; however,a municipality that requires the use of biodegradablebags might provide the bags or sell them below cost.The Table does not include an estimate of the value ofnon-m~nicipal labor in bagging leaves. This is probablya recreational activity for many residents, and the timerequired for bagging may be little more than that for

forming and reforming loose piles. Likewise, there isno clear basis for estimating the value of time spent byresidents in hauling leaves. A reasonable estimate of directcosts of hauling by residents can be based on estimatesof trip numbers and average distances in combinationwith a standardized cost per mile, such as the municipalreimbursement rate for town employees.Information on rates charged by privately hired haulersand municipal contractors can be determined by aninformal survey v,ithila the town and in nearbycommunities. Groundskeepers charge for a package ofservices. If a shift from leaf disposal to leaf compostingappears to imply little impact on leaf hauling bygroundskeepers this item can be ignored in Parts A andB of Table 5.The key to successful use of Table 5 is concentrationon major cost items that are likely to be impacted bya shift from collection for disposal to collection forcomposting. The bottom line in the Table will indicatethe change in municipal and non-municipal collectioncosts associated w ith a shift from disposal to com posting.Table 6 is a worksheet for estimating municipal costsof leaf composting. A rather specific format is providedfor estimating labor and equipment costs for each majorphase of the composting process. General data on leafweights, volumes and bag counts are given in AppendixB. Basic information on compost processing equipmentand approximate prices in 1988 are sho~n in AppendixD. However, considerable judgment and local researchwill be required to estimate costs for a particular sitewith specific types of equipment and operatingprocedures.Table 7 is a worksheet for summarizing annualeconomic benefits and costs associated with leafcomposting. The estimate of avoided cost of incinerating


39/58

or landfilling leaves should include both capital andoperating costs. The value of existing laudfill capacityowned by the to,~n should be based on its replacementcost rather than on the original cost of acquiring thesite. The value of cmnpost used by the tov,n and b3residents and businesses can generally" be based on thecost o~ the soil conditioner most likely to be used in

the absence o[ ~he compost. A lower value should beused in the case of compost uses beyond the quanititiesthat would be used iu the absence of the municipal leafcomposting program. Other benefit and cost categoriesare defined iu Table 7 and preceding tables.

23


40/58

Table 4. Worksheet for Estimating Municipal Costs of CollectionAnnual Operating Costs S/Year

I.A. Cash Expenses for Equipment (operating and maintenancecosts and/or rental costs)1. Compactor trucks:( units) x ( hr/wk) x ( wks/yr) x ($. /hr)2. Vacuum leaf collectors:( units) x ( hr/wk) x ( wks/yr) x ($_ /hr)3. Catch basin cleaners:units) x ( hr/wk) x ( wksiyr) x ($_ /hr)4. Front end loaders:

units) x ( hr/wk) x (. wks/yr) x ($. /hr)5. Dump trucks:( units) x ( hr/wk) x (. wks/yr) x ($. /hr)6. Other equipment:( units) x ( hr/wk) x (, wks/yr) x ($. /hr)Total cash expenses for equipment ........................................B. Labor1. Truck drivers:(, workers) x ( hrs/wk) x ( wk/yr) x ($. /hr) =2. Equipment operators:( workers) x (. hrs/wk) x ( wk/yr) x ($ /hr) =3. Other workers:( . workers) x (. hrs/wk) x ( wk/yr) x ($ /hr) =Total of hourly wages .........................................................Costs of fringe benefits ($. Total of hourly wages) x (_____%)__ =Total labor costs (total of hourly wages plus cost of fringe benefits) .................. =Total Annual Operating Costs (sum of parts A and B) .............................

24


41/58


42/58

Table 5. Worksheet for Estimating the Increase in Collection CostsAssociated with a Shift from Disposal to Composting.Collection Costs S/YearM u n icip a l Non-munic ipal

A. Costs of L eaf Collection if Leaves A re to b eComposted1. Bags =2. Independent hauling by:

(a) Residents(b) Groundskeepers =(c) Privately hired haulers =

3. Municipal contractors =4. Municipal crews (from Table 4) =5. Other =

Subtotal for A ................................ =

B. Costs of Leaf Co llection if Leaves Are Notto be Composted1. Bags =2. Independent hauling by:

(a) Residents =(b) Groundskeepers =(c) Privately hired haulers =3. Municipal contractors =

4. Municipal crews =5. Other =

Subtotal for B ................................ =

C. Change in Collection Costs(Subtotal A minus Subtotal B) .................=

26


43/58

Table 6 . Worksh ee t for Es t imat ing M unic ipa l Cos t s o f Leaf Com pos t ing .

I. A nnual Operating Costs S/YearA. Labor1. Site monitoring and directing of trucks whileleaves are being received:*( hrs./wk) x ( wks/yr) x ($ /hr)2. Emptying of bags:( hr/cu yd) x (. cu yd/yr) x ($ ihr)3. Equipment operator during windrow formation:(. hrs./wk) x ( wks/yr) x ($ /hr)4. Truck driver if needed during windrow formation:(. - hrs./wk) x ( wks/yr) x ($ /hr)5. Compost process monitoring:

( . hr/visit) x (. visitsiwk) x(. wks monitored/yr) x ($ /hr)6. Equipment operator for turning of windrows:(. _ hr/turn) x (. turns/yr) x ($ /hr)7. Wetting of leaves:(.__ hr/wetting) x (__ wettings!yr) x ($__ /hr)8. Other (shredding, loading, bagging, etc. as applicable): ($.9. Site monitoring while compost is being sold or given away:~( _ hrs.!wk) x ( wks/yr) x ($ /hr)

Total of hourly wages ................................................... =Costs of fringe benefits ($ ) x ( %) .................... =Total labor costs (total hourly wages plus costs of fringe benefits) .............B. Cash Expenses for Equipment (operating and maintenance costs and/orrental costs)

1. Front end loader during windrow formation:(. hrs.!wk) x ( wks/yr) x ($ /hr)2. Dump truck for moving leaves at the site:(. hrs./wk) x ( wks/yr) x ($ /hr)3. Front end loader or other equipment for turning windrows:(. hr/turn) x ( turns/yr) x ($. /hr)4. Water truck (if needed)!(. hr/wetting) x ( wettings/yr) x ($ ihr)5. Maintenance of roads, fences, drainage and water systems, and buildings6. Other equipment for shredding, loading, bagging, etc. as applicable:

Total cash expenses for equipment ......................................

one person monitors more than one activity include only the time associated with or allocated to leaf composting.

27


44/58

Table 6. Worksheet for Estimating Municipal Costs of Leaf Composting. (continued)

C.Supplies and Other Expenses1. Traiuing of perscmoel2. Replacement thermometers3. Laboratory analyses of compost4. Electricity5. Water6. Other

Total for supplies and other expenses ......................................Total Annual Operating Costs (sum of parts A, B and C) .......................lI. Annual Capital Costs (Ill each case start with tile initial capital cost of tilt

particular item and convert to an annual basis with a capital recovery factor(CRF) that includes an allowance for anllua] depleciation over the service lifeand annual interest on investment, see Appendix G.Since land does notdepreciate, the CRF for land is the annual rate of interest).A. Land ($ ) x ( CRF)B. Site Improvements

1. Site grading, drainage and roads: ($ ) x ( CRF)2. Fencing, gate, signs, and buffers: ($ ) x (. CR.F)3. Water system: ($ ) x ( CRF)4. Gate house and storage shed: ($ ) x (. CRF)5 . Othel

Annual capital costs for site improvements .................................C. Equipment (Let C/T stand for the ratio of composting usage to total usage)

1. Front end loader:($__) x ( C/T) x ( CRF) =2. Dump truck: ($ ) x ( C!T) x ( CRF) =3. Water truck: ($. ) x ( C/T) x (. CRF) =4. Other equipment for turning windrows, shredding, bagging, etc.:

($ ) x (. C/T) x ( CRF)($ ) x (. C/T) x ( CRF)

Annum capital costs for equipment ........................................Total Annual Capital Costs (sum of parts A, B and C) ..........................Annual Costs of Composting (sum of parts I and II) ............................

28


45/58

Table 7. Worksheet for Summarizing Annual Economic Benefits and Costs fromLeaf Composting

Item or Function M unicipalS/Year

Non-munic ipalA. Ben efits

1. Avoided cost of incinerating or landfilling leaves =2. Value of compost used by the municipality =3. Revenue from the sale of compost =4. Value of com post used by residents and businessesin excess of payments to the municipality =5. Other revenues or benefits =

Total Economic Benefit .......................... =B . C O S T S

1. Change in collection costs (from Table 5) =2. Municipal costs of composting (from Table 6)3. Other costs

Total Economic Cost ............................. =Net Economic B enef it (Total Economic Benefitminus Total Economic Cost) ................... =


46/58

V. Referencesand Appendicies


47/58


48/58

V. References and AppendicesReferences

Commonwealth of Massachusetts. Leaf Composting Guidance Document. Depart-ment of Environmental Quality Engineering. Division of Solid Waste Manage-ment. Boston, MA 198 8.Derr, Donn A. The Econom ics of Leaf Composting. Department of Agricultural Eco-nomics and Marketing. Rutgers University. N ew Brunswick, NJ. Research Re-port Series No. P-02550-2-85.Macy, Jack. Commonwealth of Massachusetts. Department of Environmental QualityEngineering. Division of Solid Waste Management. Boston. Telephone Inter-view, 25 July 1988 .Poincelot, Raymond P. The Biochernistry and M ethodology of Compost ing. TheConnecticut Agricultural Experiment Station. New Haven, CT. Bulletin 754.September 1975.Rice, James E. "Efficient Materials Handling: Leaf Bagging vs. Curb." Biocycle (Feb-ruary 198 8 ): 20-21.Royer Foundry and Machine Co. Municipal Leaf Compost ing. Kingston, PA 1973.State of Connecticut. Solid Waste Managem ent Plan, State o] Connecticut RegionalSolid Waste Recycling Plan, Vol. II. Department of Environmental Protection.Hartford, CT. December 198 6.Strom, F. and M.S. Finstein. Leaf Com posting Manual for New J ersey Municipali-ties. Department of Env ironmental Sciences. Rutgers University. New Bruns-wick, NJ. 198 5.Strom, Peter F. Department of Environmental Science. Rutgers University. NewBrunswick, NJ. Personal Communication, 14 April 1988.

Appendix A.Appendix B.Appendix C.Appendix D.Appendix E.Appendix F.Appendix G.Appendix H.

AppendicesTroubleshooting Guide For Operating WindrowsWeight, Volume and Bag Count DataLeaf Collection Equipment and Approximate Prices (1988)Compost Processing Equipment and Approximate Prices (1988)Sample Windrow Temperature Data SheetSample Leaf Volume D ata SheetCapital Recovery FactorValuesGlossary

3O


49/58

Appendix A: Trouble Shooting Guide For Operating WindrowsProblem Cause Solution

Odor Excess moisture Turn windrowTemperature greater than 140 F Turn or reduce windrow sizeLeaf compaction Turn or reduce windrow sizeSurIace ponding Eliminate ponding/regrade

Low windrow temperature

High windrow temperatureSurJace ponding

RatsMosquitoes

Windrow too smallInsufficient moisturePoor aerationLeaf compactionInsufficient oxygenDepressions or rutsInadequate slopePresence of garbagePresence of stagnant water

Combine windrov,,sAdd water v,bile turning windrowTurn windrowTurn or reduce windrow sizeTurn windrowFill depression and/or regradeGrade site to recommended slopedesignRemove garbageEliminate ponding

3 1


50/58

Appendix B: Weight, Volume and Bag Count DataDescription Data*

A. Bagged or loose leaves in a compactor truck:(1) Actual count based on one full load of $1 cu yd, w eighing 14,525 Ib andcontaining 1,550 bags (Springfield, MA; 19 87, reported by M acy)(2) Average b y truckload based on truck capacity without adjustmentfor partially filled loads:a. Averaged over 1,745,38 0 lb (Springfield, MA, 19 87, reported by M acy)b. Averaged ov er 1,413,010 lb (Waterbury, Ct, 198 7, from town records)(3) A general estimate (reported by Derr)

B. Loose leaves collected with vacuum equipment and blown into a leaf box:(1) Average by truckload based on truck capacity without adjustment for partiallyfilled loads:

a. Averaged over approximately 150 loads, Scarsdale, NY (reported by Rice)(2) A general estimate (reported by Derr)C. Loose leaves loaded into an open truck with a front end loader:(1) Average by truckload based on truck capacity without adjustmentfor partially filled loads:

a. Averaged over 13 loads (Springfield, MA, 198 7, reported by Mac5,)(2) A general estimate (reported by Derr)D. Bagged leaves in an open truck:

(1) Based on 9.37 lb/bag and an assumed average bag volum e of 25 gallons(3.34 cu ft/bag)

9.37 lb/bag50.0 bags/cu yd;468.5 lb/cu yd;

414 lb/cu yd555 lb/cu yd450 lbicu yd

190 lb/cu yd350 lb/cu yd

371 lb/cu yd250 lb/cu yd75.7 Ib!cu yd

*These estimates reflect a variety o1 measurement techniques, moisture conditions, and degrees of com paction and are presentedhere as a general guide.

32


51/58

A ppend ix C: L eaf Col lect ion Equ ipmen t and Ap proximate Prices in 1988Description Cost

A. Compactor trucks:(1) 20 cu yd; 240 hp diesel; automatic transmission; single axle $ 80,000(2) 25 cu yd; 270 hp diesel; automatic transmission double axle $ 95,000

Vacuum leaf collectors:(1) Trailer mounted; belt driven; 12-inch intake; 12,000 cfm;

a) With gasoline engineb) With diesel engine(2) Trailer mounted; power-take-off and clutch connection;18 -inch intake; 24,000 cfm; diesel engine(3) Trai]er mounted; impeller on engine crankshaft;18-inch intake; 22,000 cfm; gasoline engine;

a) With 1,t cu yd dump boxb) With 20 cu yd dump box

$ 20,000$ 21,500$ 14,000$ 7,500$ 14,500$ 16,000

Catch basin cleaners:(1) Complete unit including truck; 12-inch intake; 12,000 dfm; diesel enginea) 10 cu yd capacityb) 16 cu yd capacity $100,000$120,000

33


52/58

Appendix D: Compost Processing Equipment and Approximate Prices in 1988Description Cost

A. Front endloaders:(1) 90 hp w ith 1.75 cu yd bucket $ 55,000(2) 115 hp with 3 cu yd bucket $ 70,000(3) 155 hp tractor (without bucket) $ 8 0,000

a) 3 cu ydbucket $ 4,800b) 7 cu yd woodchip and snow bucket $ 7,400c) Qu ick attachment system $ 3,900(4) 8 2 hp tractor (without bucket) $ 60,000

a) Lease with 1.6 c~ yd bucket $ 2,600/month(5) 123 hp tractor (without bucket) $ 8 7,000a) Lease with 2.4 cu yd bucket $ 3,600/month(6) 158 hp tractor (w, ithout bucket) $111,000

a) Lease with 3.0 cu yd bucket $ 4,600/month(Note: Based on experience in Springfield, MA , a 3 cu yd loader can turn approximately I8 0 cu yd per hour "a, ith eachload lifted high and allowed to cascade into a new windrow.)

Special ized aerating and turning eq uipment:(1) Flail type; self propelled; turns windrows up to 7 ft. high and 18 ft. wideat a rate of up to 3,000 tons per hour; 360 hp; not easily transportedbetween sites (10 6" wide and 14 6" high on low b ed trailer)(2) Auger type; mounted on a tractor that can be used with numerous optional

attachments; turns windrows up 6 ft. high and 10 ft wide at a rate of up to3,000 tons per hour; engine options of 177 to 225 hp; not convenient forlong distance transport; can be driven on road at a maximum speed of20 mi/hr(3) Flail type; powered by 177 hp engine while attached to a front loader (loadernot inchaded); turns windrows up to 5 or 6 ft. high and 14 ft. wide at arate of up to 8 00 tons per hour; can be loaded on a flat bed truck with a frontend loader equipped w ith a quick catch system(4) Flail type; attaches to a large farm type tractor with a three point hitch andpower-take-off (The tractor should have 100 to 225 hp and a hydrostatictransmission or a creeper transmission with 2 or 3 speeds under 1/3 mi/hr withpower-take-off at 1,000 rpm); turns windrows 5 to 6 ft. high and 14 ft. wideat a rate of up to 600 tons per hour; special wheels for over the road transportSeparat ing and shredding equipment:(1) 25 cu yd/hr; 18 hp gasoline engine(2) 75 cu yd/hr; 55 hp diesel engine(3) 200 cu yd/hr; 110 hp diesel engine

$160,000

$180,000

65,000

$ 30,000

$ 17,000$ 40,000$ 9 1,000

34


53/58

Appendix E: Sample Windrow Temperature Data SheetData collected by: Year: Month:

Weather Information (Sunny, rain, etc.).Wind direction (from Northeast, South, etc.)Air Temp erature: F Time of day:Site Observation C omm ents (Water ponding, dust, etc.).

Windrow M oisture ("Hand squeeze" test observation) circle item:Needs moisture Satisfactory ExcessOdor (circle item): None Minimal Strong

Temperature Observation, Findrow temp eraturemeasurement location: Windrow O bservation (See Sketch Below)

Diagram

Actions Taken (turned w indrow, graded, etc.):

35


54/58

Appendix F: Sample Leaf Volume D ata SheetMonth Year

[ Vehicle No.__i Type.ICap.

i DATE1 Loads

2

27

Cu.Yd.CY!Tons

Cap. Cu.Yd. i Cap. Cu.Yd.Loads CY/Tons I Loads CY/Tons ]

Vehicle No.--Type.Cap. Cu.Yd.Loads CY/Tons TOTAL

Source: New Jersey Office of Recycling (Form OR-3A)

36


55/58

Appendix G: Capital Recovery Factor Values~Interest Rates

Years 7% 8% 9% 10%12345678910

1.0700 1.08 00 1.0900 1.1000.5531 .5608 .568 5 .5762.3811 .3880 .3951 .4021.2952 .3019 .308 7 .3155 2439 .2505 .2571 .2638.2098 .2163 .2229 .2296 1855 .1921 .198 7 .2054 1 6 7 5 .1740 .18 07 .1874.1535 .1601 .1668 .1736.1424 .1490 .1558 .1627

The formula for computing capital recovery factors not presented hereis as follows:CRF = i(l+ i)n(1 + i)n - 1where: i = interest or discount raten = numb er of yearsSource: Derr, Donn A. The Economics o[ Lea] Composting

Department of Agricultural Economics andMarketing, Cook College, Rutgers University,Research Report Series No. P-02550-2-8 5Note: This is only one of numerous methods of calculating annualdepreciation and interest on investment. If an allowance is to be madefor salvage, value straight line depreciation and average annual intereston investment can b e calculated as follows:

annual depreciation = (c - s)/nannual interest = i(c + s)/2

where: c = initial costs = salvage valuen = service life in yearsi = annual interest rate

37


56/58

Appendix H: Glossary of Composting Terms

Aerated Static Pile Composting: A method of composting organic wastes in which oxygenand temperature levels are mechanically controlled by blowing air through a staticpile.Aerobic Com posting: Decomposition of organic wastes by microorganisms in the presence

Documents

Compost: Send Your Leaves to a MULCH Better Place