canada animal manuremanagementguide

PUBLICATION 1534

A FEDERAL/PROVINCIAL PUBLICATION

CANADA ANIMAL MANURE MANAGEMENT GUIDEThis publication has been revised by the Animal Manure Management Committee under theauthority of the Canada Committee on Agricultural Engineering Services. The CanadaDepartment of Agriculture has agreed to publish the Guide, in accordance with the terms ofreference of the Federal-Provincial Cooperative Committee on Agricultural Communications.

The Guide Committee

E.M. Barber (Chairman), British Columbia Ministry of AgricultureF.R. Hore (Co-chairman), Canada Department of AgricultureM. Pascua, Newfoundland Department of Forestry and AgricultureA. Raad, Prince Edward Island Department of Agriculture and ForestryW.C. Durant, New Brunswick Department of Agriculture and Rural DevelopmentJ.D. Gunn, Nova Scotia Department of Agriculture and MarketingM. Fortier, Quebec Department of AgricultureD.E. Presant, Ontario Ministry of Agriculture and FoodD. Hogkinson, Manitoba Department of AgricultureM. Wrubleski, Saskatchewan Department of AgricultureB.S. West, Alberta Department of AgricultureW.M. Carson, Nova Scotia Technical CollegeJ.B. McQuitty, University of AlbertaJ. Pos, University of GuelphJ.B. Robinson, University of GuelphD.D. Schulte, University of Manitoba

Acknowledgment

The Committee gratefully acknowledges the contributions to this guide by many engineers andscientists, with special credit to J.R. Ogilvie, University of Guelph and J.E. Turnbull, CanadaDepartment of Agriculture

PUBLICATION 1534, available fromInformation Services, Agriculture Canada, Ottawa K1A 0C7© Minister of Supply and Services Canada 1980Cat. No. A53-1534/1980 ISBN: 0-662-10604-0Revised 1980 Reprinted 1981 5M-11:81

Also available in French

CONTENTS

Caution to be observed in using this guide 4Introduction 5Regulatory programs covering management practices 6

Federal 6Provincial 6

Manure management 10Importance 10

Water pollution 10Manure gases 10Odors 11Other concerns 12

Management principles 12Use of manure in crop production 13

General information 13Fate of manure nutrients applied to cropped soils 13Manure nutrients as potential environmental contaminants 14Manure application rate 14

Site selection, land-use planning and building construction 15Site selection 15Land-use planning 15Farm building construction 16

Manure handling systems 17Introduction 17Parts of the system 17

Collection and transfer 17Storage 18Removal, transport and land incorporation 24

Beef cattle 25Dairy cattle 26

Milk center wastes 26Swine 29Poultry 30

Dead bird disposal 30Processing of animal manure 32

Anaerobic processes 32Anaerobic lagoons 32Anaerobic digesters 32

Aerobic processes 33Oxidation ditches 34Aerated lagoons 34Composting 34

Dehydration 35Incineration 35

Appendix 1 — Properties of the principal manure gases and their physiological responseon adult humans 36

Appendix 2 — Volume of dilution water required to change the moisture content of manure 37

TABLES

Table 1 - Nutrients ingested and excreted by 15 feeder pigs (18-90 kg) 13Table 2- Nitrogen, phosphorus and potassium excreted by animals over a 365-day period 13Table 3 - Animal manure characteristics (nominal values for urine and feces as voided) 19Table 4 - Manure handling systems for beef cattle 26Table 5 - Manure handling systems for dairy cattle 27Table 6 - Sediment tank capacities for milk center wastes 28Table 7 - Size of underground disposal field for milk center wastes 28Table 8 - Manure handling systems for swine 29Table 9 - Manure handling systems for poultry 30

ILLUSTRATIONS

Figure 1 — Curbed storage slab for stacked manure (CPS plan M-2703) 20Figure 2 — Open circular manure storage with tractor access (CPS plan M-2701) 21Figure 3 — Curbed slab manure storage with earth banks (CPS plan M-2704) 21Figure 4 — Rectangular roofed storage for semisolid manure (CPS plan M-2705) 22Figure 5 — Rectangular roofed manure tank (CPS plan M-3753) 23Figure 6 — Below-ground open circular manure tank (CPS plan M-3752) 23Figure 7 — Clay-lined manure storage pond with pumping dock (CPS plan M-2702) 24Figure 8 — Above-ground liquid manure silo with tractor pto pump system (CPS plan 3750) 25

CAUTION TO BE OBSERVED IN USING THIS GUIDE

Information presented in this guide is based onmaintaining an ecological balance betweennutrients supplied by animal manure andfertilizer and nutrients used by crops, withoutundue nuisance from other properties ofmanure. Individuals not trained or experiencedin animal manure management should notextract portions of the guide, nor drawinferences, without considering all aspects ofthe problem from the source of the manurethrough to its re-utilization by crops.

Information is also presented on the nitrogencontent of farm-animal manure. To avoid anymisunderstanding, the amount of nitrogenexcreted by an animal is not the same amountavailable when the manure is applied to thecrop. The amount of nitrogen availabledepends on the method of handling andprocessing, and should be assessed for eachdifferent type of management system.

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INTRODUCTION

Public concern continues about all formsof pollution. At the same time, intensiveanimal operations, some on limited land areas,have increased in number and size. This trendtoward increased scale of animal confinementfor production of meat, milk and eggsmagnifies the problems of manuremanagement and increases the possibility ofcausing pollution.

Furthermore, the number of animaloperations with little or no cropland availablefor manure utilization and the number ofresidential dwellings on or near farmland isincreasing. This often results inpollution-related disputes between urbanresidents and animal producers, particularly inthe densely populated areas of Canada. Thus,there is a need for properly designed andmanaged animal facilities, and for control ofthe number of residential dwellings on or nearfarmland. Land-use policies must be developedthat take into account the special requirementsof animal production.

The fundamental basis for soundmanure management practices is anappreciation of the natural role that animalmanure plays in un-managed soil-plantsystems. This leads to the realization that themost appropriate management of manure is toreturn it to soil, thus using it as a nutrient incrop production. The guiding principle is thatnutrients returned to the soil should be

matched to specific crop requirements. Evenso, special precautions may be required toprevent air and water pollution before, duringor after land application of the manure.

Unlike many facets of animalproduction, the technology related to manurehandling still is developing rapidly. Extensionpersonnel, regulatory officials, producers andresearch workers must realize this, so thatproblems may be minimized throughup-to-date management practices.

The purpose of this guide is to focusattention on those practices that provide areasonable yet environmentally sound basis formanure management. It gives descriptions ofalternate practices which, though not yetcommonly employed, may prove useful to boththe agricultural community and to those whoplan, regulate or assess animal manuremanagement systems. However, the guide isnot a detailed design manual; rather itprovides a common basis for understandingmanure management practices across Canada.It is a place to start and should be used withthat in mind.

Finally, this publication is intended as acommon foundation for new or revisednational, provincial and other jurisdictionalregulations, codes or guidelines on animalmanure management, that eventually can bemade consistent with one another.

5

REGULATORY PROGRAMS COVERING MANAGEMENT PRACTICES

Federal

At the federal government level, the FisheriesAct has implications in all parts of Canada since thislegislation covers the control of pollution in waterfrequented by fish. Also, the Canada Water Actprovides for the conduct of cooperativefederal-provincial watershed studies. The results ofthese studies can be used to establish water-qualitystandards for the watershed.

Provincial

Major responsibility for the regulation of farmnuisance and pollution problems continues to be atthe provincial level. After early experimentalapproaches to this tough regulatory problem, thereis now a tendency to regulate farm pollutionproblems through guidelines and education programsas opposed to the use of specific and detailedregulations. A growing number of provinces areadopting a certificate of compliance program whereinwritten approvals are given to operations thatcomply with recognized standards. More animalproducers sit on advisory and inspection committees.Several provinces are giving new emphasis toland-use planning in an attempt to prevent problemsbefore they occur.

British Columbia — British Columbia has adopteda system of agricultural pollution control whereby thelivestock and poultry industries regulate their ownsanitation and pollution problems. The B.C.Agricultural Environmental Control Program isadministered by the B.C. Federation of Agriculture.Producer sanitation committees investigatecomplaints and make recommendations specific toeach farm, based on defined environmentalguidelines. The full force of the Pollution Control Actis brought to bear on farmers who refuse to complywith the recommendations.

To supplement this program, British Columbianow is experimenting with the application ofMinimum Distance Separation Formulas, admin-istered at the municipal level, to control the siting oflivestock and poultry buildings.

Regulatory agencies with authority to controlwaste management on British Columbia farms are:

! Pollution Control - Pollution ControlBranch, Ministry of Act, 1967Environment

! Ministry of Health - Health Act! Ministry of Municipal - Municipal Act

Affairs and municipal

governments! Ministry of Lands and - B.C. Water Act

Forests! Environment Canada - Fisheries Act! Ministry of Agriculture - Milk Industry Act

Alberta — The agricultural environmental controlprogram in Alberta is based on voluntary guidelinesand is administered jointly by Alberta Agriculture andAlberta Environment. The program educates farmerson good manure management methods andcoordinates the various regulatory agencies listedbelow. This program has avoided a tough regulatoryapproach to the problem of agricultural pollution.Operations meeting the guidelines are issued acertificate of compliance.

Complaints made to Alberta Environment areinitially turned over to Alberta Agriculture where anamiable solution is attempted. When a solution is notobtained by negotiation, the matter reverts to theagency whose jurisdiction is involved. Recentincreased involvement by the agricultural industryitself indicates the possibility of greater self-policingby producer groups.

Formulas are being developed to aid in theorderly siting of agricultural and non-agriculturaldevelopments. These formulas may be used toimplement land-use plans at the local level.

Regulatory agencies with authority to controlwaste management on Alberta farms are:

! Local governments - Building permits, development bylaws, set backs, etc.

! Regional Planning - Municipal PlanningCommission or ActProvincial Planning Director

! Alberta - Developments onTransportation provincial highways

! Local boards of - Provincial Board ofhealth Health Regulations

under the Public Health Act! Alberta Environment - Water Resources Act

- Clean Air and Clean Water Acts- Joint administration of certificate of

compliance program! Alberta Agriculture - Regulations under the

Alberta Dairyman's Act Joint administration of certificate of compliance program

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Saskatchewan — The Family Farm ImprovementBranch of Saskatchewan Agriculture administers ThePollution (By Live Stock) Control Act, 1971. This actempowers the Minister of Agriculture to issue permitsfor the construction of facilities for intensive livestockoperations. Failure to apply for a permit mayconstitute an offence under the act.

Before the Minister issues a permit, approvalmust be received from the Ministers of Health,Tourism and Renewable Resources, and Environ-ment. Copies of the applications are also sent forcomments to rural municipalities, nearby urbanmunicipalities, and other affected agencies.

Complaints against intensive livestockoperations are investigated by Branchfarmstead-engineering specialists who recommendcorrective measures. Generally speaking,cooperation from farmers is excellent. If necessary,the Minister may issue orders under the act to cleanup operations. Failure to comply with a Minister'sorder constitutes an offence under the act.

The Saskatchewan Intensive LivestockOperations Code of Good Practice recommends isola-tion distances and other practices for locating andoperating intensive livestock operations. TheDepartment of Agriculture has shared in the costs ofrelocating facilities to more desirable locations whenthere are no other alternatives for pollution control.

The Minister of Agriculture has appointed acommittee representing livestock producers to advisehim on the administration of this act.

Manitoba—The management of animal wastes isprovincially regulated under the Clean EnvironmentAct and the Public Health Act. The livestock wasteregulation under the Clean Environment Act outlinesthe basic requirements for the storage and disposalof animal wastes and the disposal of dead animals.Certain livestock operations in locations of potentialconcern are further required to register with theDepartment of Mines, Resources and EnvironmentalManagement, which administers the act.

Regulations under the Public Health Actadministered by the Department of Health and SocialDevelopment deal with the protection of watersources and the location of, and sanitation in,facilities for the keeping of animals. There is overlapbetween the two acts in this regard with the latterbeing very antiquated in the area of livestockproduction.

To date, prosecutions under any of theseregulations have been few. Education and persuasionhave been used in lieu of force to change wastemanagement practices. Particular cases where it isdifficult to apply or interpret the legislation arehandled individually with cooperation betweenAgriculture, Environmental Management and theclient. Hopefully the forthcoming review and revisionof regulations pertaining to the management of

livestock wastes will eliminate much of the ambiguityand redundancy of the current legislation.

Ontario— Ontario attempts to prevent pollutionfrom animal manure by means of manuremanagement information and guidelines in the formof an Agricultural Code of Practice. MinimumDistance Separation Formulas are used for sitinglivestock buildings and manure storages. Theseformulas are also used to site rural residences, bothfarm and non-farm, in relation to neighboringlivestock operations.

Certificates of compliance are issued jointly bythe Ministries of Environment and Agriculture andFood to farmers who can meet the siting distancesand who agree to specific conditions of manuremanagement appropriate to their operations.Municipalities are required to include reference to theAgricultural Code of Practice in official plans and thusin zoning bylaws.

Air or water pollution violations by livestockoperations are dealt with initially by the Ministry ofthe Environment which then consults with Ministry ofAgriculture and Food engineers on recommendationsfor abatement. Continued violation is referred to aFarm Pollution Advisory Committee composed offarmers representing each of the major livestock andpoultry groups. Failure to follow therecommendations of this group results in a violatorbeing subjected to legal action under theEnvironmental Protection Act.

Ministries of Agriculture and Food, Environmentand Housing participated in and sponsored the thirdrevision of the code published in 1976.Relevant legislation is:• The Environmental Protection Act, 1971, ad-

ministered by the Ministry of The Environment• The Ontario Water Resources Act, administered

by the Ministry of The Environment• The Milk Act, administered by the Ministry of

Agriculture and Food• Fisheries Act, administered by Environment

CanadaQuebec— Farming comes under the Environ-

ment Quality Act (December 1972) which states thatcontaminants emitted by these operations must notaffect the life, health, safety, welfare or comfort ofhuman beings, nor cause damage to the quality ofthe soil, vegetation, wildlife or property. Farmingoperations are subject, moreover, to the ProvincialHealth Regulations (1944) concerning fox farms,pigpens, barns, stables, yards and manure.

A draft regulation under the Environment QualityAct concerning animal farming operations ispresently being prepared. This will regulate thelocation of animal production sites, and the storageand disposal of manure from animal operations.

New Brunswick — The Agricultural Environ-mental Control Program in New Brunswick is

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administered jointly by the Provincial Departments ofAgriculture and Environment. Under this programevery livestock farmer is requested to obtain acertificate of compliance. Farmers who borrowmoney through either the federal or provincialloaning agencies for construction of their livestockfacilities are required to have a certificate ofcompliance before a loan is approved. Thesecertificates are issued jointly by the twoDepartments. Farmers who cause a pollution hazardcan be forced to comply with pollution controlregulations under the Clean Environment Act.

Regulatory agencies with authority to controllivestock manure and waste management in NewBrunswick are:• Department of - Clean Environment

Environment Act- Unsightly Premises Act

• Department of Health - Health Act• Department of - Community

Municipal Affairs Planning Act• Environment Canada - Fisheries Act

Nova Scotia— The proper use and storage ofanimal manure on livestock farms in Nova Scotiacomes under the Environmental Protection Act asenacted in 1973. This act is administered by theNova Scotia Department of Environment which hascomplete authority to control manure management.As yet, no regulations have been established underthe act that give specific requirements for storageand handling of manure.

A set of guidelines covering the storage andhandling of manure was established by personnelrepresenting the departments of agriculture of thefour Atlantic Provinces. Later, another set ofguidelines for Nova Scotia was developed by acommittee representing the Departments ofEnvironment, Health, and Municipal Affairs, and theFederation of Agriculture.

Regulatory agencies with authority to controlanimal manure and waste management in NovaScotia are:• Department of the - The Environmental

Environment Protection Act- Water Act

! Department of Health - Health Act! Department of - Municipal Act

Municipal Affairs

Prince Edward Island — With the exception ofnewly established piggeries and poultry operations,Prince Edward Island has opted for guidelines andextension education programs to promote andupgrade sound animal waste management on farms.New piggeries and poultry operations which havebenefited from public funds in their establishmentunder provincial capital grants programs, such as theFamily Farm Development and New Farmer

Programs, have to meet animal waste managementguidelines before they are approved for publicfunding. This is usually done through inspection andthe issuing of a certificate of compliance to theseguidelines by the P.E.I. Department of Environment.

Usually, complaints attributed to animal wastepollution are referred by the P.E.I. Department ofEnvironment to the P.E.I. Department of Agricultureand Forestry for action and follow-up. In resolvingthese complaints, staff of the P.E.I. Department ofAgriculture and Forestry usually resort to nothingmore than good public relations augmented bywhatever technical engineering and financialassistance is available and warranted in each specificcase.

The only acts which could be used to enforceacceptable standards of pollution abatement are TheAct to Establish the Environmental ControlCommission administered by the P.E.I. Departmentof Environment and The Public Health Actadministered by the P.E.I. Department of Health.

Newfoundland — The Newfoundland AgriculturalEnvironmental Control Program is administered bythe Department of Consumer Affairs andEnvironment and the Department of Forestry andAgriculture.

Complaints are investigated by the environmentofficers of the Department of Consumer Affairs andEnvironment and the agricultural representatives ofthe Department of Forestry and Agriculture. Theysubmit their corresponding reports to an inter-departmental Livestock Waste ManagementCommittee for evaluation and appropriate action.The same procedure is applied to both new andexisting livestock or poultry producers. Decisionsmade by this committee are based on guidelinesrecently legislated by Council and on the existingacts of other regulatory agencies concerned.

The regulatory agencies with authority to controlwaste management in Newfoundland are:! Department of - The Waste Material

Consumer Affairs (Disposal) Actand Environment - The Environmental

Management and Control (Water and Sewage) Regulations

- Prevention and Control of Air Pollution- Soil Regulations- Legislated Livestock Waste Management

Guidelines! Department of - Milk and Its Product

Health Act- Meat and Meat Product Act

! Environment - Fisheries ActCanada

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Other agencies involved in the issuance ofpermits to build are:

! Development Control Division, Department ofMunicipal Affairs and Housing

! Provincial Planning Office! Department of Transportation and

Communications! Public Health Inspection Services Division,

Department of Health! Environmental Management and Control Divi-

sion, Department of Consumer Affairs andEnvironment

! Agriculture Division, Department of Forestry andAgriculture

! Municipal or Community Council Authority (ifapplicable)

9

MANURE MANAGEMENT

Importance

Manure resulting from animal production can bedetrimental to the environment and a hazard to thehealth and safety of both humans and animals.Even if adequate facilities for manure handling andstorage are provided, difficulties still may occur.Hence an awareness of the potential hazards orproblems associated with animal manures and anunderstanding of the circumstances involved canminimize the risks and lead to the development ofsound manure management practices. The solutionto many of the potential hazards or problems is firstto recognize their existence and second to exercisecare and common sense to avoid them. Some of themore important considerations follow.

Water Pollution

A characteristic of animal manures is their highwater pollution potential. Hence a major objectiveof efficient manure management must be to ensurethat manure or its constituents cannot gain accessto rivers, streams, lakes or water supplies.

Manure contamination of water can occur in anumber of ways, some of which are more obviousthan others. Obvious examples are direct dumpingof manure into surface water, providing animalsdirect access to streams for drinking, runoff fromfeedlots and manure stockpiles, and overflow frommanure storages of inadequate capacity. The lessobvious ways include spring surface runoff followingwinter application of manure on frozen groundsloping towards a stream, seepage from excessivelyhigh application rates on land and from lagoons anddetention ponds constructed in porous soils. Undercertain conditions, various manure constituents maybe carried downwards by water percolating into thegroundwater. There is also a possibility ofabsorption of air-borne manure constituents bynearby bodies of water downwind from the opera-tion.

There are several consequences of waterpollution by animal manures. Oxygen in the wateris depleted because the bacteria demand it todecompose the organic matter in the manure. Thisdemand is known as the biochemical oxygendemand (BOD) of the manure. If dissolved oxygenconcentrations are seriously depleted, the watermay no longer support desirable aquatic life such asfish but instead becomes septic and unpleasant. Theaddition of manure constituents such as nitratesand phosphates to water also may cause orcontribute to eutrophication and the resultantunsightly growth of algae.

Contamination of water by manure poses a

serious health hazard to humans and animals, wateracting as the carrier of numerous disease pathogensfrom infected animals. In addition, contaminatedwater can be responsible for nitrate poisoning in bothanimals and humans, particularly infants. Manurealso can impart taints and odors to drinking water.

Manure Gases

Manure undergoes microbial decomposition afterit is voided by the animal. The organic matter isbroken down to simpler compounds, the processbeing characterised by the production and evolutionof numerous gases. If the decomposition takes placein the presence of oxygen (O2), the process is said tobe aerobic and, when it occurs in the absence of O2,the process is called anaerobic. In practice, mostmanure storages are anaerobic. Anaerobicdecomposition is typical of liquid manure handlingsystems and characteristic of collection pits, holdingtanks and storage lagoons.

Aerobic decomposition is essentially an odorlessprocess whereas anaerobic decomposition ischaracterised by bad odors. In addition, the lattercan produce gases, in considerable quantities, whichare potentially hazardous to man and animals. Theseinclude carbon dioxide (CO2), methane (CH4),ammonia (NH3) and hydrogen sulfide (H2S). Some ofthe properties and physiological effects on humans ofthese gases are given in Appendix 1.

Manure gases have caused fatalities and nearfatalities, involving both humans and animals, andproperty damage and loss. Such accidents are theresult of high concentrations accumulating undercertain conditions. These conditions occurinfrequently and are largely recognizable.

Carbon dioxide is seldom a critical problem inanimal housing. Instances have occurred wherefailure of the mechanical ventilation system in atightly constructed barn has resulted in animaldeaths, probably due to a combination of heat stressand O2 deficiency rather than CO2 asphyxiation. Analarm system to warn the operator in the event ofsuch a failure would be a prudent investment.

Methane also is unlikely to be a factor in animalhealth and performance in normally ventilatedbuildings. Its significance lies in its flammable andexplosive nature. At low concentrations, it burns witha pale blue flame, but at higher concentrations thereis a real danger of an explosion. The head space ofa covered manure storage is an example of whereexplosive concentrations may collect. To minimizethe risks from CH4 in and around manure handlingand storage facilities, prohibit smoking or use ofnaked flames, use explosion-proof electric motors onfans and equipment, adequately vent covered

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storages to outside air, use U-bends or gas traps inall sewage channels connecting a barn to outsidestorage tanks so gases in the tank cannot back upinto the barn, and ensure that a barn with insidemanure storage is continuously ventilated (ifunventilated for even a short period, thoroughlyvent before use).

Ammonia, with its sharp pungent odor, acts asan irritant to moist tissues such as eyes and therespiratory tract even at relatively lowconcentrations. High or even moderateconcentrations in the animal environment are not aconcern, as these have not been found. Rather,quite low concentrations, readily detectable tohumans, appear to decrease animal health andperformance in the presence of other atmosphericcontaminants such as dust and H2S. Rapid manureremoval from the barn, adequate floor slopes toensure good drainage, liberal use of bedding andincreased ventilation rates (particularly duringemptying of storages) are possible methods ofreducing concentrations.

Hydrogen sulfide is potentially the mostdangerous of the manure gases and has killed bothhumans and animals in Canada and many othercountries. Constant exposures to concentrations ofonly a few parts per million or short exposures tointermediate concentrations also are suspected ofbeing detrimental to animal well-being. Normally,H2S is barely detectable in animal housing as longas the liquid manure remains undisturbed. Evenslight agitation of storages or disturbance of gutterswill release H2S to the atmosphere. Concentrationsappear to be largely a function of the length of timethe manure is stored and the degree of agitation ordisturbance. The greatest risks are during emptyingof tanks and pits, when concentrations in thepithead space and above slats can reach lethallevels within a few minutes. To minimize risks fromthis gas, do not agitate when emptying pits locatedwithin a building and at the same time providemaximum ventilation, remove stock from a buildingwhen agitation is necessary (or, if stock cannot bemoved, make use of a windy day to ensure amaximum air exchange through open doors andwindows), use gas traps in sewage channelsbetween covered outside pits and barns to preventgas back-up, and empty pits frequently, particularlyin warm weather.

Entering manure storages at any time isextremely dangerous, especially during orfollowing emptying of the storage. Consequently,never enter such a facility without being properlyequipped with air-breathing apparatus andsafety harness. Omit the air-breathing apparatusonly when positive ventilation has been providedby fans of sufficient capacity to ensure that

manure gases are purged from the storage headspace and a constant supply of fresh air isavailable.

Odors

Possibly the most common complaint directed atanimal production facilities is about the bad odorsthey produce. Many of these complaints occur at thetime manure storages are being emptied and themanure field-spread. The odors are the result of thebiological breakdown of the manure under anaerobicconditions within storages, whether these be piles,lagoons or indoor pits.

Many compounds are involved in manure smells.Some, such as NH3 and H2S are produced in easilydetected quantities. Others, such as mercaptans andamines, are present in concentrations measured inparts per billion, that are only detectable by highlysophisticated analytical techniques and equipment.Even at such concentrations, a number of thesecompounds can be perceived as offensive by thehuman nose. Consequently, consider the odornuisance of animal manures to minimize the risks ofcomplaints.

In recent years, manure odors have been thesubject of extensive research around the world. Twobasic approaches have been used: preventing theproduction of malodors in the first instance, orattempting to eliminate the odor after it has beenproduced. Unfortunately, neither approach has founda practical low-cost solution to the problem, for avariety of reasons. As a result, the animal produceris left with sound planning and management as themost effective means of minimizing the odornuisance. Planning authorities as well as operatorsmust recognize, however, that malodors cannot beeliminated even with the best possible planning andmanagement.

Minimizing odor nuisance is basically commonsense and a respect for the rights of others. Locateanimal facilities so that prevailing winds blow awayfrom nearby residences. Local municipalitiesfrequently have regulations governing minimumdistances between them. Avoid spreading manure onland adjacent to residences or main roads unless themanure is either injected directly into the soil orincorporated immediately into it by cultivation. Eithermethod not only reduces offensive odors duringspreading but also minimizes the high nitrogenlosses to the atmosphere that normally occur whenmanure lies on the soil surface.

Local weather reports provide a valuablemanagement tool in minimizing odor nuisance. Fieldspread manure on cool windy mornings when thewind is blowing away from nearby residences, as thisis least likely to cause offense. Odors from manureapplied to fields late in the day tend to be trapped

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near the ground because the air is cooling andfalling. Again, don't field spread on weekends andduring holidays as neighbors are more likely toobject at such times.

A high standard of hygiene within barns willminimize the indoor odor problem. Thoroughcleaning and frequent manure removal to storage,coupled with good drainage and liberal use ofbedding where appropriate all contribute, since thebreakdown of feces and urine requires, among otherthings, time and moisture. Good hygiene also willreduce atmospheric dust concentrations and, sincedust is a carrier of odors, the exhaust air from barnswill be less offensive.

Other Concerns

Animal production raises other concerns thatmay require consideration. Manure, for example,makes an ideal breeding ground for various insects,including flies, and tends to attract birds and evenrodents. All of these can be a nuisance and possiblecarriers of disease.

The noise generated by animals in confinementcan be another annoyance to nearby residents.Aesthetics are also a legitimate concern for,although an animal production unit can be an assetin one setting, it may detract from another unlesssuitably screened.

Dust, to a varying degree, is a feature ofanimal production units. Not only a physicalnuisance, it also carries odors and could transmitcertain disease pathogens. Dust is more likely to bea problem in total confinement of poultry(particularly deep litter), and pigs. Blowing dustfrom feedlot operations can be a nuisance to nearbyresidents.

Management Principles

To think that an animal production operationcan be maintained without some impact on thenatural environment is unrealistic. However, theextent to which it may be detrimental dependsprimarily on its management. The uniqueness ofeach animal production unit must be stressed; notwo situations are identical. Although differentoperations may have several common features, thebest way to minimize the environmental hazard

from animal manure is to examine the managementoptions available in each case.

Consider the following:

Is adequate land available for crop utilization ofmanure, having regard to the rate and time ofapplication to avoid water pollution and tomake most efficient use of the plant nutrientscontained in the manure? If the land base isinsufficient, investigate alternative means ofmanure disposal to arrive at an environmentallysatisfactory solution.Ensure sufficient manure-storage capacity toeliminate uncontrolled release of manure intothe environment, avoid land application ofmanure during winter, and permit most effectivecrop use of nutrients. Storage must be of a typethat will eliminate seepage to groundwater.Locate animal production facilities to avoidnuisance complaints about odors, dust, flies,noise and aesthetics, by providing adequateseparation and suitable screening.Use weather conditions to best advantage tominimize odor nuisance during field spreading ofmanure. Better still, use soil injection or rapidsoil cover of manure, and gain the additionalbenefits of greatly reduced nitrogen losses andcontrol of possible pollution arising from surfacerunoff.Control manure gases, particularly from storedliquid manure, to ensure the safety and healthof both humans and animals, either by frequenttransfer of manure from animal facilities toseparate storages or by exhausting enough airfrom the headspace in indoor storages toprevent gas build-up.Provide drinking water facilities for animals onpasture so they won't drink from, andcontaminate, streams or lakes.

In any given situation most or all of the aboveprinciples may require examination in detail toachieve an environmentally and economicallyacceptable animal manure management system. Themanure handling and storage alternatives outlined inthe following sections offer the opportunity to makemanagement decisions, based as closely as possibleon the requirements of these principles.

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USE OF MANURE IN CROP PRODUCTION

General Information

The nutrients contained in manure have theirorigin in animal feed and, by measuring intake,excretion and weight gain it is possible to prepare,for each class of animals, a nutrient budget asshown in Table 1. While the numbers differ fordifferent animals and for different diets, the re-covery in the manure for each of the three principalplant nutrients is generally 65 to 90%. Whenanimals are on range, these nutrients are returneddirectly to the soil from which they were derivedand the net loss from the soil of most nutrients,including phosphorus (P) and potassium (K), isrelatively small. In the case of nitrogen (N), the lossmay be greater but is made up partly by naturalfixation. In recent years, management has changedfrom essentially pastoral to a more intense systemin which the animals are continuously housed oroccupy only small land areas. Feed grown elsewheremust be imported to such animal concentrationsand, as manure accumulates in these feeding areas,so do plant nutrients. To ensure these nutrients donot threaten the quality of groundwater or surfacewater, they must be applied to cropland in arational way. Therefore blocks of productiveagricultural land must be maintained close to animalproduction enterprises. This should be a majorconsideration of all land-use planning.Fate of Manure Nutrients Applied to Cropped

SoilsTable 2 shows the approximate major nutrient

content of manure from different types of animals.The nitrogen in freshly excreted manure is in theorganic form, which is converted to ammonium-nitrogen during storage or after application to soil.Since ammonium is firmly held to the surfaces ofsoil particles, it does not leach easily, but undersome conditions may be converted to ammonia gaswhich volatilizes. Large quantities of N may be lostin this way from manure lying on the soil surface,particularly in dry, warm and windy weather.

Certain soil microbes convert ammonium-nitrogen to nitrate-nitrogen. This form of N is notadsorbed to soil and may be leached from the rootzone depending on the amount of water movementin the soil. Nitrate-nitrogen may also be lost whenother microorganisms convert it to gaseouscompounds such as nitrous oxide, or to freenitrogen (denitrification) when oxygen is in shortsupply in soils. Thus, when soils are very wet,nitrate may be leached out of the root zone withpercolating water or it may volatilize as a result ofdenitrification.

Crops generally have higher requirements forN than for the other major elements. Bothammonium- nitrogen and nitrate-nitrogen are takenup by plants.

Table 1 — Nutrients Ingested and Excreted by 15 Feeder Pigs (18-90 kg)

Ingest Excrete(kg) (kg) (%)

Nitrogen 105 68 65Phosphate 59 41 69Potash 32 27 84

Table 2 — Nitrogen, Phosphorus and Potassium Excreted by Animals over a 365-day Period*

Nitrogen (kg of N)

Phosphorus(kg of P2O5)

Potash(kg of K2O)

1 dairy cow (545 kg) 64 30 802 beef cows (182-500 kg) 64 30 806 pigs (14-90 kg) 64 36 22120 hens (2.3 kg) 64 51 28180 broilers (0-1.8 kg) 64 29 25

* Adapted from Land Requirements for Utilization of Liquid Manure in Crop Production by G E Jones, T H. Lane,and L R. Webber. Ont Dept. of Agr and Food Information Leaflet. June 1968.

Note: Figures refer to freshly voided manure and include feces and urine The kind of manure management system

13

has a very large influence on actual nutrient content at time of land application.

Phosphorus is taken up by plants in the form ofmineral phosphates which normally arise in soil fromthe weathering of the soil's parent material, from theaddition of fertilizer P or from mineralization oforganic P. The P in manure may be inorganic ororganic; the organic component mineralizes ratherslowly in soils and so not all of it is immediatelyavailable for crop uptake. Phosphates, unlikenitrates, are virtually immobile in mineral soilsbecause, if not used by plants, they form insolublecompounds in combination with calcium, iron oraluminium. At normal soil pH an equilibrium existsbetween the insoluble complexes and theplant-available phosphate so that, at any time, asmall proportion of the soil P will be available toplants.

Soils generally have large stores of potassium,up to 10 times as much as either N or P. While muchof this K is unavailable at any one time, somerelease brings this element into the soil solution,from which it may either leach or be taken up byplants. Most of the K added to soils in manure isreadily available, and during the first season, iseither taken up by the crop or adsorbed on the soilto become available later. In the soil, K is not subjectto conversions and losses like N, nor is it fixed asfirmly in insoluble compounds as is P.

Manure Nutrients as PotentialEnvironmental Contaminants

Manure applied to soils may influence waterquality in a number of ways, the extent dependingon such factors as cropping practices, localtopography, soil type, precipitation and season. Themost direct contamination occurs when manure,applied to sloping frozen land on top of snow, iswashed directly to a watercourse when the snowmelts. Occasionally, similar effects may result whenheavy rain occurs immediately after manureapplication to unfrozen soil. Addition of manure towater enhances algal and/or submerged plant growthbecause of the increased nutrients, creates ademand on the dissolved oxygen as organic matterdecomposes, and introduces potentially pathogenicbacteria to the water.

Over-application of manure to any soil over along term will build up the nutrient content of the soil(the P content is of particular concern) far beyondcrop requirements. Sediments eroded from thisheavily enriched soil will cause greater waterpollution with P, the critical nutrient in aquatic

systems, than sediments from normal productivesoil.

Over-application of manure may also result innitrate contamination of groundwater. Nitrate shouldbe kept from entering groundwater or surface waterbecause of its potential toxicity to animals andinfants when consumed in the water supply. Whilethe tolerance for nitrate is moderately high(regulatory agencies generally accept a limit of 10milligrams of nitrate-nitrogen per litre of drinkingwater), cases are on record of groundwater suppliesfar exceeding acceptable levels. High concentrationshave often been traced to mismanagement of animalmanure.

High concentrations of nitrate in forages and incorn plants may occur when nitrate levels far exceedthe crop requirements. High nitrate forages haveoccasionally been implicated in illness or death ofcattle. In silage corn it may lead to dangerousaccumulations of gas in the newly-filled silo when thenitrate is reduced to nitrogen oxides.

Manure Application Rate

In estimating the best application rate ofmanure to a particular soil, consider:• the texture and fertility level of the soil; • the nutrient requirements of the crop to be

grown;• the nutrient contents of the manure;• local climatic factors which will affect the fate of

each of the major nutrients (as describedabove); and

• the objective of safe, pollution-free recycling ofmanure nutrients.

The nutrient balance in manure (i.e., the N:P:Kratio) may not be ideal for the specific soil-plantrequirements. For example, if sufficient manure isapplied to meet the annual requirement for N, the Papplication may be excessive. On the other hand,just meeting the phosphorus requirement would inthat case require a nitrogen supplement. The actualapplication rate may represent a compromise; thekind of compromise reached should consider localrequirements and conditions. For that reason,consult the appropriate provincial agency and, withas much information as can be gained from soiltests, crop requirements, and manure analyses, planyour manure utilization system according toprovincial recommendations.

14

SITE SELECTION, LAND-USE PLANNING AND BUILDING CONSTRUCTION

Site Selection

Selection of a barn or feedlot location on an animalproduction farm is most important. You must haveessential services, enough area, and suitablesurroundings.Essential services are:

feed and water;electricity; andtransportation and traffic routes.

Sufficient area for:animal pens or buildings;feed and manure storage;control of snow, wind and runoff;manure application on productive land; andexpansion.

Suitable surroundings concern:topography and drainage;natural shelters and screening;proximity to operator's residence;compatibility with adjacent land uses; adequate separation from neighbors andresidential and recreational areas;location and uses of nearby bodies of water andwater courses; andenvironmental and zoning regulations.Each farm needs individual consideration and

some points discussed may be covered by provincialor local legislation. Consult local authorities beforeconstruction.

Use prevailing winds to advantage to carryunavoidable odors away from neighbors and thefarmhouse. Also, locate the site as far as possiblefrom neighboring dwellings to allow dilution of odorsand minimize nuisance from noise and flies. Consultthe appropriate local authorities about requiredseparation distances.

Avoid low areas subject to flooding. The siteshould have a natural slope to provide drainageaway from the barn or feedlot. A natural slope allowsgravity flow of liquid manure to a storage or feedlotrunoff to a detention basin. Site a feedlot at the topof a ridge, or construct a ditch or terrace above thelot to intercept and divert unpolluted runoff water.

A uniform slope of 2 to 5% and a relativelyimpervious soil (loam to clay loam) is desirable forunpaved feedlots. However, sand or gravelly soil isbetter beneath paved areas to promote good naturalor artificial drainage, minimizing the risk of heavingand cracking of the pavement.

Select an impervious clay site for below-groundstorages. If any sand or gravel is found in theexcavation, provide an impervious lining to protectagainst groundwater pollution.

As a further precaution, locate animal facilitiesand manure storages far enough from surface bodiesof water to permit the construction of additionalpollution control works if necessary.

The accumulation of some snow, which getsmixed with manure on open confinement areas, ispractically unavoidable in most parts of Canada. Tominimize snowdrifts, select a site about 30 to 60 mdownwind from a porous windbreak such as ashelterbelt of trees or shrubs. Alternatively, build awindbreak 3 to 3.5 m high of boards spaced toprovide about 20% porosity, to allow a large part ofdrifting snow to settle before it reaches the feedlot.

Land-use Planning

Land-use planning, proximity to proposed orexisting residences, and prevailing-wind directionmust be evaluated before constructing or modifyingan animal operation. Good relationships betweenfarmers, neighbors and regulatory bodies areabsolutely necessary. It is impossible to control allodors from an animal operation, particularly atmanure-spreading time, as existing technologycannot cope fully with a little ‘country atmosphere'from time to time. Residents and regulatory officialsmust be made aware of manure management froman agricultural point of view.

Land-use planning officials hopefully will avoiddirect zoning of residential areas into predominatelyagricultural areas and thus minimize future conflictsbetween residents and farmers. An earlier statementin this publication is repeated for emphasis:Therefore blocks of productive agricultural land mustbe maintained close to animal productionenterprises. This should be a major consideration ofall land-use planning. An agricultural operation in anarea zoned for agriculture is expected to representreasonable land use.

Provincial agricultural advisors, representativesof regulatory agencies and farmers are workingtogether with municipal authorities to plan anddevelop guidelines for rational land use. Forexample, in Ontario an Agricultural Code of Practicehas been developed featuring Minimum DistanceSeparation Formulas. These formulas are applied toboth farming and non-farming land uses to assessthe environmental commitment as compared toother alternatives. A similar system, based on theOntario formulas, is being developed in BritishColumbia and Alberta with the express purpose ofmaintaining buffer zones between non-compatibleland uses.

15

Farm Building Construction

Farm buildings should be designed andconstructed in accordance with the Canadian FarmBuilding Code.1 They also should meet local healthand sanitation requirements.

The Canada Plan Service (CPS) Design Centerprepares detailed large-scale plans for Canadianagriculture. Prepared in cooperation with theprovinces, the plans are available at provincialdepartment of agriculture distribution centers orfrom local extension advisers.

In areas where the climate is humid and mild,the installation of eavestroughs on buildings to divertroof drainage away from the site is recommended. Incolder climates with deep snow, eavestroughingrequires too much maintenance; therefore provide agravel splash pad at the base of the wall to controlerosion from roof runoff, and slope roofs away fromopen lots. It is important to divert uncontaminated

runoff, including roof runoff, away from open-lotareas to lessen the manure washed away and thevolume of waste to be handled.

While management systems should be employedthat reduce dust and dust-borne odors from barnventilation systems, the problem cannot becompletely eliminated. Hence, exhaust the air awayand downwind (if possible) from residences. Tallstacks help dilute dust and odors, but are not alwayspractical, because of the high cost of stacks largeenough for summer ventilation, stack freezing, andicing of fans that operate intermittently.

__________1 Issued by the Associate Committee on the National

Building Code, National Research Council ofCanada, Ottawa.

16

MANURE HANDLING SYSTEMS

Introduction

Most manure handling systems for confinedanimal operations have common parts that functionin the following sequence: collection (temporarystorage); transfer to storage; storage; removalfrom storage; transportation to land; landapplication and incorporation. Some of the basicrequirements for these parts are discussed under"Parts of the System".

Although manure handling systems arefunctionally similar and some pieces of equipmentare common, there is in practice no single system.Because the methods of animal management andthe properties of manure are not the same for allanimals, different systems have been developed foreach kind of animal. Those for beef cattle, dairycattle, swine and poultry are outlined in detail laterin this section and where necessary, the effect ofclimatic differences across Canada have been takeninto account. Some of the alternate systems shownfor each kind of animal differ simply in the provisionof more or less automation. Other alternatives aretied specifically to given methods of animalmanagement and particularly to the way freshmanure is modified in its consistency (its resistanceto movement or separation). The consistency offresh manure always is changed, more or less,somewhere within the handling system.

Although other factors are involved, themoisture content of manure has an important effecton its consistency and hence on the selection ofhandling equipment and facilities. Based onconsistency, manure is handled generally as aliquid, solid or semisolid. For example, where animalmanagement practices exclude or restrict the use ofbedding, liquid manure with a thin consistency isproduced by adding water (intentionally, or fromleaky waterers). Some liquefaction also takes placewhen liquid manure is stored anaerobically. At 85%moisture content or greater, liquid manure will flowby gravity from deep horizontal gutters, and, at90% or greater, it can be pumped readily. Appendix2 contains a useful graph to determine the amountof dilution water required to change the moisturecontent. Where ample bedding is used or manure issubjected to natural or induced air drying, solidmanure is usually produced. It has a stiff,non-flowing consistency and can be handled by anestablished line of solid manure equipment. Anexample is manure with 8% bedding or greater.There are, however, existing management practiceswhere the amount of bedding or drying is limited,and thick semisolid manure is produced that mayflow slowly or hardly at all. For instance, whenabout 2% long straw bedding is added to fresh dairycattle manure, the mixture will likely flow slowly,

whereas very little flow will occur with additions ofabout 4%. Some modifications to conventional solidmanure facilities and equipment are required to handlesemisolid manure.

In each of the alternate systems outlined later,manure consistency is taken into account by specifyingthe type of handling facilities and equipment required.

Parts of the System

Collection and Transfer

Odor production in confinement barns can beminimized when collection facilities are small andmanure is transferred at frequent intervals to separatestorage; the in-barn environment, is subjected only tothe unavoidable odors of animals and fresh manure.On the other hand, large collection facilities for liquidmanure become anaerobic manure storages. Wherecollection and storage are combined within a barn, youneed special precautions to minimize risks fromhazardous gases released during agitation and/oremptying, as discussed earlier under "Manure Gases".

Transfer equipment must be suited to theconsistency of the manure. For solid manure,mechanical equipment is readily available to scrape (orload), convey and stockpile the manure. Tractorscoops, box-type manure spreaders and pumps can beused to transfer semisolid manure. If tractor scoopsare used, the manure must be pushed against asubstantial buck-wall to load the scoop. Also, wherebox-type manure spreaders are used, end-gateattachments will be needed to contain the manure inthe spreader. Enclosed-chain conveyors are a low-costalternative to more expensive pumps.

Liquid manure can be transferred horizontally fromthe collection area by gravity flow in deep gutters,hydraulically in shallow trenches, or by mechanicalscrapers. Where site conditions allow storage below thelevel of the collection area, collected manure may bedelivered directly into a separate large storage.However, transfer pumps or elevators are requiredwhere the storage is above the collection area.Conventional open impeller sewage pumps are usedsuccessfully, although they do clog occasionally. Helicalrotor pumps also are used but the synthetic rubberstator can be damaged by small rocks or by operatingthe pump dry. More costly non-clog pumps, usedsuccessfully for years in municipal sewage treatmentplants, are available; these have smooth-vanedrecessed impellers that will pass any solids that canenter the pump inlet. Piston pumps with large pistonsthat push manure through 8- to 16-in. PVC piperecently have been gaining acceptance by animalproducers. These pumps can move manure horizontally45 m or more, depending on the consistency.

17

Where manure enters directly into a separatelarge storage from the collection area, precau-tionary measures are needed to protect the barnfrom dangerous gases from the storage. Gas trapsinvolving baffles and/or intermediate chambers areacceptable. Alternatively, if the openings betweenthe barn and the storage are small and the storagetank is completely enclosed, a continuous-runningfan exhausting from the storage to the outside airwill give similar protection plus some barnventilation.

Storage

Storage structures are required to holdmanure, wastewater and feedlot runoff betweenperiods of land application. Although different farmshave different storage needs, several general pointsrelated to storage location, size, construction andoperation should be observed. Specific requirementsdiffer for solid, semisolid and liquid manure.Detailed plans for several types of storages,prepared by the Canada Plan Service (CPS), areavailable through extension engineers at provincialministries or departments of agriculture.

Location — Locate the storage convenient tothe barn or feedlot but at a site that will allowexpansion of the animal facilities and the storage. Itshould be accessible by firm farm roads to alloweasy transport of manure and equipment to andfrom the storage. For below-ground storages, avoidareas with a high water table and choose a sitewhere surface-water runoff may be diverted. Thesoil should be compacted well to prevent differentialsettlement of the storage structure and, where anearthen storage is considered, should be sufficientlyimpervious to contain manure liquids.

Sizes— The size of manure storage depends onthe type and number of animals, the length of timethat manure is stored and, with liquid manure, thevolume of dilution water added. The daily volumesof fresh manure produced by different animals areshown in Table 3. The number of animals is theaverage number confined during the storage period,not the number of animals produced. The storagetime period should be sufficient to avoid having tospread manure on snow, frozen ground or sensitivecrops. Fall and spring applications are best,requiring up to six months storage capacity for mostfarm situations. In regions with a long winter,storage capacity for 200 days or greater may berequired. To minimize the space required in a liquidmanure storage, avoid excessive amounts ofdilution water. Unless land application through anirrigation system is planned, add only enough waterto bring the moisture content to about 90% for easyagitation and pumping.

To determine the size of manure storage, use

the following formula:

Vs = [(Na x Vm x T)/1000] + Vw

where Vs = volume of storage, in cubic metres Na = number of animals confined during

storage periodVm = volume of manure produced, in litres per

animal per day (see Table 3)T = storage time in daysVw = volume of dilution water required for

liquid manure storages, in cubic metres(see Table 3 for moisture contents offresh manure and Appendix 2 fordilution water needed to changemoisture contents)

The size of detention basins (usually earthen) to storecontaminated runoff from open feedlot and manurestorage areas depends on the size of the runoff areaand the amount of runoff that occurs during the criticaltime that storage is required. Under most Canadianconditions, this critical period is the winter 6 months orgreater, to avoid application of the runoff on snow orfrozen ground. To obtain a design value for the amountof runoff, there are estimating formulas. A localhydrologist can use these, taking into account theconditions familiar to him. To obtain a firstapproximation for design, use the following formulas asa guide:

For paved feedlotsV = A x (0.48 Pm + 0.65 Ps) For unpaved feedlotsV = A x (0.22 Pm + 0.45 Ps) For solid manure storages V = A x (0.25 Pm + 0.65 Ps)

where (in any consistent units),V = volume of storageA = area contributing to runoffPm = sum of the November to April (6

months) mean monthly total pre-cipitation (rainfall plus equivalent waterdepth of snowfall)2.

PS = the 24-hour precipitation from a stormexpected once in 25 years3.

These formulas suggest that the design storagecapacity be based on the detention of winter runoffplus the storm runoff that may occur before emptyingthe storage in the spring. At that time, and at timesfollowing major runoff events between May andOctober, the runoff is applied to crop land for utilizationof the fertilizer nutrients in the runoff.__________2 Available from publications by the Atmospheric

Environment Service, Environment Canada, Downsview,Ontario.

3 Available from "Short duration rainfall intensity —duration frequency" data prepared by AtmosphericEnvironment Service, Environment Canada, Downsview,Ontario.

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Table 3 - Animal Manure Characteristics (Nominal Values for Urine and Feces as Voided).

Animal

Volumeof manure/animal*(L/day)

Volume ofmanure and

bedding /animal*(L/day)

Undilutedmanuremoisture

(%)

Urinein

manure(%)

BOD/animal(g/day)

Nutrients/animal**

N(g/day)

P2O5(g/day)

K2O(g/day)

CattleBeef or dairy calf (0-3 mo) 5.4Beef or dairy calf (3-6 mo) 7.1Beef feeder or dairy heifer

(6-15 mo) 14.2 17.0 35 77 36 91

Beef feeder or dairy heifer (15-24 mo) 21.2 22.6

Beef cow (545 kg) 28.3 34.0Dairy cow (545 kg) 45.3 87 30 900 172 82 204

Open pen loose housing 56.6Free stall loose housing 48.1Tie stall 50.9

Swine20-90 kg (8-22 wk) 5.1 91 45 135 32 18 115-10 kg (3-6 wk) 1.111-20 kg (6-9 wk) 2.321-35 kg (9-12 wk) 3.436-55 kg (12-16 wk) 5.156-80 (16-20 wk) 7.481-90 kg (20-22 wk) 9.1Sow 11.3 13.6

Chicken 0Broiler (0-1.8 kg) 0.08 0.14 litter-25Laying hen (1.8 kg) 0.14 77 9 1.45 1.1 0.6

Turkey 75 0Broiler (0-14 wk) 0.13Growing hen (0-22 wk) 0.18Growing tom (0-24 wk) 0.28Breeder 0.34

Rabbit (doe and litter) 0.71Ewe sheep 2.8 4.2 75 50 40 20 7 17Horses 26.0 56.6 80 20 122 50 91Mink (female and kits) 0.20* Adapted from Canadian Farm Building Code, Associate Committee on the National Building Code, National Research Council

of Canada, Ottawa ** Manure analyses by an appropriate laboratory are advisable since the actual nutrient contents can vary in practice

Although a settling basin is not always installedbetween the feedlot and the detention basin to removesome of the solids from the runoff, its use isrecommended. As a guide to design, the surface area ofthe settling basin should be about 1/40th of the feedlotarea that contributes runoff, and the basin should be 0.6m in depth or greater, but not exceeding 1.2 m. Anearthen settling basin should have a paved ramp and padif the solids are to be removed with a tractor scraper.

Construction - Storage facilities for manure or runoffshould be manure-tight to avoid water pollution. Althoughmost storages are constructed as single units, multipleunits may be required where it would be uneconomical tobuild beyond a particular capacity, or where agitationequipment has limited capacity.

Solid manure storages require a slab to provide footingfor the operation of loading equipment and a perimetercurb to contain the liquid runoff (Figure 1). In areas ofheavy precipitation, it may be economical to either add aroof, or to drain the runoff to an adjacent holding basin to

provide increased liquid storage. The floor of the storageshould slope to a low corner, preferably that cornerdiagonally opposite to the paved entrance ramp. The crownof the ramp and the top of the perimeter curb should all beat the same level for maximum liquid retention.

Semisolid manure storages require a slab surrounded byeither a concrete wall (Figure 2) or a low curb surroundedby an earthen embankment to contain both the liquid runoffand the sloppy manure (Figure 3). A ramp entranceprovides access for manure removal equipment. Theentrance ramp is crowned to exclude drainage water fromthe yard. The floor slab slopes to a low point at the corneropposite the entrance ramp to facilitate complete removalof the liquid fraction by a vacuum tanker or an irrigationsystem. An optional drain or porous wall at the low cornermay be installed to allow liquids to pass into a separatestorage basin.

In areas of heavy precipitation, it may be economical touse a roof over a rectangular walled storage as in Figure 4.

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Figure 1 — Curbed storage slab for stacked manure (CPS plan M-2703)

Liquid manure storages are either below orabove the collection facilities. Storages below guttersor alleys can be either rectangular (Figure 5) orcircular (Figure 6) reinforced concrete structures toaccommodate gravity transfer from the barn.Agitation is necessary and commonly is donehydraulically with a tractor pto-powered liquidmanure pump. The effective agitation radius usingthis method is limited to about 7 to 9 m; therefore,large circular storages should be limited to 15 m indiameter with tractor accesses at two opposite sides.Rectangular storages work best if divided intocompartments no larger than 7 by 9 m with thepump access opening located centrally along onelong side. Where odors from storages will create a

nuisance, rectangular storages can be covered atless cost than circular storages. Inexpensive earthenmanure storages can be used but they require asuitable dock to place a tractor and a pump agitatornear the deepest part of the storage for manureremoval (Figure 7). A slab of pavement isrecommended under the pump location to preventerosion while pumping. Unless manure is pumpedunder pressure to earthen storages, the inlet pipeshould be above the liquid level in the storage;submerged inlets under gravity flow may plug.Earthen storages also are limited to manure-tightsoil conditions (otherwise a waterproof lining will berequired), and to locations where odors will notcreate a nuisance.

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Figure 2 — Open circular manure storage with tractor access (CPS plan M-2701).

Figure 3 — Curbed slab manure storage with earth banks (CPS plan M-2704).

21

Liquid manure storages located above thecollection facilities can be circular concrete structuresbuilt mostly above ground. These storages have beentraditionally of a silo type, 9 m in diameter by up to9 m high (Figure 8). Larger diameter silos, includingsome up to 18 m and occasionally up to 24 m,recently have been gaining acceptance as agitatorpumps improve. Above-ground storages must bemanure-tight. For poured concrete structures, thiscan be achieved by using good quality concrete, withspecial reinforcement to resist liquid pressures. Forconcrete stave structures, a waterproof plastercoating is required. The sump pump and plumbingsystem is a most important part of above-groundstorages. It must be able to transfer manure into thestorage at convenient intervals, agitate the manurebefore removal from storage and remove manurefrom the storage and fill a tanker. A suitable sumppump and plumbing arrangement is shown in Figure8, but other arrangements may be used. Above-ground storages overcome construction problems inhigh water-table areas and provide a degree of safetydue to the height of access. Although the concreteconstruction costs are generally less than forbelow-ground structures with roof or cover in areaswhere there are experienced silo contractors, theoverall cost due to the required pump and plumbingis about the same. Liquid manure forms a crust morereadily in silo-type storage, so odors are negligibleexcept when pumping out.

Operation of liquid manure storage— Some of the

measures you can take to minimize operatingproblems are:• Disturb liquid manure in storage as little as

possible, to minimize the emission of odors.Odors are further reduced by covering thestorage.

• Add only enough dilution water to allow agitationand pumping. Excess water increases storagerequirements (or reduces the length of storageperiod for existing structures) and increases thequantities to be handled.

• Avoid coarsely ground feeds, particularly withswine. These feeds can create flow andsettlement problems in conduits, gutters andstorages.

• Avoid additions of hay and bedding; where hay isfed, chopped hay creates fewer pumpingproblems than long hay.

• Provide adequate agitation before removingmanure from storage. Avoid agitation when thewind is toward neighbors.

• When manure enters a separate covered storagethrough barn openings, exhaust ventilate fromthe storage or provide a gas trap, to preventback-flow of odorous and dangerous gases intothe barn.

• Remove animals and open all doors for maximumventilation when agitating open storages withinthe barn, to avoid gas hazards.

• Fence open-top outdoor storages to excludechildren and domestic animals.

Figure 4 — Rectangular roofed storage for semisolid manure (CPS plan M-2705).

22

Figure 5 — Rectangular roofed manure tank (CPS plan M-3753).

Figure 6 — Below-ground open circular manure tank (CPS plan M-3752).

23

• Keep covers for equipment-access openings intocovered storages securely in place when not inuse. Covers should weigh 20 kg, should not float,and should either be larger than their openings orbe secured with a safety chain so they can't fallinto the storage.

• Do not enter an indoor or covered storagewithout taking special precautions. Make sure it iswell ventilated and wear a rope safety harness.Have at least two men standing by on the ropeoutside the storage in case of emergency. As anadditional precaution, wear a self-containedbreathing apparatus.

• Do not smoke or use matches or an open flamewhile inspecting an unventilated storage tank.Some manure gases, particularly methane, canbe explosive when mixed with air (see Appendix1).

Removal, Transport and Land Incorporation

Conventional handling equipment is available toremove, transport, and spread solid and liquidmanure on the land. Special equipment (that isavailable) and special facilities are required to handlesemisolid manure. These include a buck-wall for ascoop loader to work against and either a boxspreader with end-gate or an open-top, flail-type tankspreader.

Application of manure onto cropland via sprinklerirrigation has not proven acceptable to many farmersbecause of problems with labor, equipment andodors; where irrigation is planned, manure must bediluted to about 95% moisture content to make amixture liquid enough for successful pumping andsprinkling.

An alternative to storing liquid and solid fractionsof manure in a single storage and handling themtogether is to use suitable drains that let the liquidcollect in a separate basin. From here it can bereadily pumped through an irrigation system ontoadjacent fields. The semisolid manure remaining thencan be handled more easily with sludge pumps ortractor scoops.

To minimize the odor nuisance when fieldspreading, manure should be applied downwind fromneighbors and during periods of the day when airmovement favors odor dispersal. Covering manure byplowing or disking as soon as possible after spreadinggreatly reduces odor and keeps manure from washingoff fields with the surface runoff.

Although not widely practiced, two methods forincorporating liquid manure into the land have beendeveloped. In the plowdown method, inexpensivehoods are fitted to tanker outlets to divert manuredownward into a 1.8 m swath; a second tractor, withwheels set wide apart and pulling a plow slightlywider than the swath, follows the tanker and covers

Figure 7 — Clay-lined manure storage pond with pumping dock (CPS plan M-2702).

24

the swath within seconds. This method is not efficientfor most farm operations with only one tanker, but itcan be used if neighbors pool equipment.Concentrating manure in a relatively narrow swathresults in application rates higher than those obtainedwith conventional spreading equipment. However, byreducing the tanker outlet to 75 mm in diameter,reducing the discharge pressure at the outlet, andtravelling at 5 to 6 km/h, the application rate can bekept below 100 t/ha.

The second method for land incorporation of liquidmanure is soil injection. This holds the greatestpotential for odor control, for lengthening the timemanure can be applied in the spring, for incorporatingmanure into hay and pasture without completelydestroying the crop, and for achieving an acceptablerate of application. Soil injectors now available leadliquid manure under pressure from the tanker throughtubes located behind deep cultivator teeth. Somerefinements are still needed to avoid buildup ahead ofthe injector unit, to ensure adequate coverage behindthe unit, and to make injectors suitable for row-cropapplication under a wide range of soil conditions. Forthe corn producer, injection may extend the time hecan apply manure between rows by a few weeksduring the critical work period in the spring; for thehay and pasture producer, manure may beincorporated without plowing and unnecessary loss ofcrop.

Existing rapid cover plow-down and soil injectionequipment is designed for liquid manure and is notsuitable for producers who have an odor problem with

solid and semisolid manure. Where rapid covertechniques cannot be used, an alternative is preciseplacement of manure on the ground surface. Manureis forced out of the spreader and drops to the groundbetween two curtains or through flexible drop tubestrailing just above the ground. This technology hasbeen developed recently in Europe; it likely will findapplication on Canadian farms where odors and spraydrift from field spreading have become a problem.

Beef Cattle

Five alternate manure handling systems are shownin Table 4. The first two require minimum capitalinvested in housing, but need a relatively largefeedlot, for example, 18 to 28 m2 per feeder. Carefulmanagement is important to control the high runoffand odor pollution possible with open-dirt feedlots.Good drainage combined with the regular mounding ofmanure is essential to maintain high levels ofsanitation and minimize odor nuisance. Drainage,however, must be controlled in leak-proof storage toavoid surface and groundwater contamination. Tominimize the groundwater pollution hazard presentedby infiltration and deep percolation of nitrated beneathactive feedlot surfaces, an undisturbed soil-manureinterface should be maintained when manure is eithermounded on the lot or removed during the clean-outoperation. Snow control around the feedlot isimportant, as well as provision of diversion ditches toprevent outside water from entering the lot.

Figure 8 — Above-ground liquid manure silo with tractor pto pump system (CPS plan 3750).

25

The third system, which combines open feedlotand covered shelter, is more suitable for humidregions. Less area is required, for example, 5 to 6.5m2 per feeder. A paved feedlot facilitates easy andfrequent cleaning.

The last two systems are totally covered feedlotswhich allow the lowest area per animal, for example,2 to 3 m2 per feeder. Confinement housing for beefcattle requires considerable engineering input relatingto proper ventilation, slat design, manure tank designand access for manure removal. Operators consideringthe extremely high investment for a fully confinedfacility should obtain agricultural engineeringassistance far beyond what this guide provides.

Dairy Cattle

Table 5 shows manure handling systems for thetwo common types of animal management, tie stalland free stall. For tie stall management, manure canbe handled as a solid, semi-solid or liquid. The threealternate systems for free stall management takeadvantage of the lesser bedding requirements andprovide for handling manure as either a liquid or semi-solid.

Milk Center Wastes

Where manure is handled as a liquid, all milkcenter wastes are best used to dilute the liquidmanure in

Table 4 — Manure Handling Systems for Beef Cattle.

Type of animalmanagement Type of manure Collection, transfer and storage Removal and transport to land Comments

Open field andwoodlot

Field droppings

Manure near feeding - watering sites

On slab or ground

Spread by cattle

Tractor loader to spreader toland

If slab not used at feed andwater site, change sitelocations periodically tominimize large concent-rations of manure. Avoidsites where pollution ofnatural bodies of water willoccur

Open dirt feed-lot (dry climate)

Lot manure withbedding added

Tractor scraper to mounds on lot Tractor loader to spreader toland

Mound seldom needs to beremoved if it can bemaintained firm and dry.Divert outside water awayfrom feedlot.

Wet manure near feedbunks and waterers

Tractor scoop to curbed storage slab Liquids drain to settling basin,solids loaded to spreader to land

Storage slab may be upperpart of settling basin

Lot and storage slabrunoff

Surface drains to settling basin.Overflow stored in detention basin

Settling basin sludge: Tractorloader to spreader to land.

Obtain local advice regardingsize of settling and detentionbasinsDetention basin liquid: Vacuum

tanker to land OR

Pump to irrigation system to landOpen pavedfeedlot andcovered beddedarea (humidclimate)

Solid manure incovered bedded area

On paved or dirt floor Tractor loader to spreader toland

Provide sufficient headroomin bedded area for beddingpack plus cattle space (3-3.7 m typical)

Semi-solid manure onpaved lot

Tractor scraper to stock pile on curbedslab

Tractor loader to spreader toland

Let snow and ice mixed withmanure melt and drainbefore handling

Lot and stock pilerunoff

Surface drains and/or sewers to earthdetention basin or concrete tank

Vacuum tanker to land OR

Pump to irrigation system to landCovered feedlotwith solid floor

Solid manure inbedded area

On paved or dirt floor Tractor loader to spreader toland

Provide sufficient headroomin bedded area for beddingpack plus cattle space (3-3.7 m typical)

Unbedded manure atfeeding- watering area

To handle as semisolid manure, tractorscraper to stockpile on outdoor curbedslab. (see CPS plans M-2701, M-2703,M-2704, or M-2705). Retain runoff onslab, or drain to earth detention basinor concrete tank

Tractor loader to spreader toland

Use box spreader withendgate or open-topflail-type tanker

To handle as liquid manure, tractorscraper to storage tank (see CPS plansM-3752 or M-3753) or earthen storage(see CPS plan M-2702)

Pump-agitator to tanker to land

Covered feedlotwith fully slottedfloor

Liquid manure Manure through slotted floor to tankstorage below

Pump-agitator to tanker to land When agitating liquidmanure, remove cattle andopen all doors to avoid gashazard

26

Table 5 — Manure Handling Systems for Dairy Cattle

Type of animalmanagement Type of manure Collection and transfer Storage Removal and

transport to land Comments

Tie stall withbedding (see CPSplan 2220)

Solid manure

Manure stack runoff

Shallow gutter, gutter cleanerto elevatorSurface drain and/or sewer

Stack on curbed slab(CPS plan M-2703)Retain within storage,or drain to detentiontank or earthen basin(CPS plan M-2703)

Tractor loader tospreaderVacuum tanker, orpump-filled tanker, orirrigation

In cold climates, manuredropped from a stackerwill freeze into a verysteep cone and willinterfere with stackeroperation

Tie stall with limited bedding(see CPS plan2220)

Semi-solid manure Shallow gutter, gutter cleanerto storage, or gutter cleaner toshort term holding tank andby plunger pump through pipeto storage OR

Stockpile in walledstorage (CPS plansM-2701, M-2704,M-2705)

Tractor loader tospreader, or tractorscraper and ramp tospreader, or sludgepump to spreader

Semisolid handlingrecommended withuncut hay or bedding

Grate-covered deep gutter,continuous gravity flow tostorage, or gravity flow toshort term holding tank andby plunger pump through pipeto storage

In high precipitationareas, consider drainingstorage with separatestorage and handling ofliquid fraction

Liquid fraction instorage

Retain within storageor drain to detentiontank or earthen basin

Vacuum tanker, orpump-filled tanker, orirrigation

Tie stall withrestricted choppedbedding (see CPSplan 2220)

Liquid manure Grate-covered shallow gutter,gutter cleaner to storage; orgutter cleaner to short termholding tank and pump to longterm storage

OR

Above-grade silo typestorage (CPS plan3750), or concretestorage tank (CPSplans M-3752, M-3753)or earthen storage(CPS plan M-2702)

Agitation, then bygravity or pump toopen-top tanker, orby vacuum tanker

Where storage is indirect contact withcollection area,continuous tan exhaustto prevent gas entry andcold drafts into barn

Grate-covered deep gutter,continuous gravity flow tostorage, or gravity flow toshort-term holding tank andpump to long-term storage

Free stall withpaved passages;limited bedding(CPS plans 2101,2104, 2106, 2112)

Semi-solid manure Tractor scraper to buck- wallto storage

ORTractor or shuttle scraper toopening into storage or toelevator into storage, or toshort-term holding tank andplunger pump to long-termstorage, or to cross gutterwith continuous gravity flow tostorage

Stockpile in walledstorage (CPS plansM-2701, M-2704,M-2705)

Tractor loader tospreader, or tractorscraper and ramp tospreader, or sludgepump to spreader

Semisolid handlingre-commended withuncut hay or beddingIn high precipitationareas, consider drainingstorage with separatestorage and handling ofliquid fraction

ORTractor scraper to buck-wall orramp to truck or spreader todistant storage

Liquid fraction instorage

Retain within storageor drain to detentiontank or earthen basin

Vacuum tanker, orpump-filled tanker, orirrigation

Free stall withpaved passages;restricted choppedbedding (CPS plans2101, 2104, 2112)

Liquid manure Tractor or shuttle scraper toopening into storage, or toshort-term holding tank withpump to storage, or to crossgutter with continuous gravityflow or gutter cleaner tostorage

Above grade silo-typestorage, (CPS plan3750), or concretestorage tank (CPSplans M-3752, M-3753)or earthen storage(CPS plan M-2702)

Agitation, then bygravity or pump toopen-top tanker, orby vacuum tanker

Close floor openingsfrom barn into storagewhen agitating holdingtank

Free stall withslotted floorpassages, restrictedchopped bedding(CPS plan 2102)

Liquid manure Manure through slotted floorto trench below, flush trenchwith pump recirculationsystem, pump-agitator tolong- term storageOR

Above grade silo-typestorage (CPS plan3750), or concretestorage tank (CPSplans M-3752,M-3753), or earthenstorage (CPS planM-2702)

Agitation, then bygravity or pump totop loading tanker, orby vacuum tanker

When flushing trenches,remove cattle and openall doors to avoid gashazard

Manure through slotted floorto deep gutter below,continuous gravity flow tostorage, or gravity flow toshort-term holding tank andpump to long-term storage

27

storage. Depending on the location of the storage, theycan either flow to the storage through a pipe and gastrap, or collect in a sump from which they are pumped bya float-operated, sewage-type sump pump (CPS Plan2102 shows such a system). However, the addition ofmilk center wastes to a manure storage will reduce theeffective capacity of the storage by 25% or more.

Where liquid manure storage is not available, solidmanure preferably should be removed from the milkingparlor floor and placed in the manure storage. Milk centerwash water may be delivered through a pipe and gas trapto a lagoon, a collection tank or a sediment tank andunderground disposal field. Lagoons may be suitable insome areas but Canadian field experience is limited andprior approval from local authorities should be obtained.Follow recommendations contained in Part 2 of theCanadian Farm Building Code4 for the construction ofaerobic lagoons, but the lagoon effluent unlikely will beacceptable for discharge into surface waters. Therefore,provide for periodic application of the lagoon contents tocropland. The recommended loading rate is based onproviding 4.5 to 5.5 m2 of lagoon surface area per cowmilked.

________4 Issued by the Associate Committee on the National Building

Code, National Research Council of Canada, Ottawa.

Particularly in milder climates, milk centerwastes may be collected in a concrete tank andapplied to adjacent cropland via a pump andsprinkler system on a regular basis, usually every2 to 4 weeks. Never apply milk center wastes in thismanner onto snow covered or frozen fields, and takecare to prevent surface runoff to a watercourse.

For the sediment tank and disposal field system,recommended tank sizes are shown in Table 6 andrecommended sizes of disposal field are shown inTable 7. However, where manure gratings or floordrains collect manure solids in the milking parlor andthese solids are added to the milk center wastes, thesediment tank sizes in Table 6 should be doubled.Construct sediment tanks to permit easy inspectionand removal of sediment. Individual practice deter-mines the rate of sediment accumulation in the tankand depends on the amount of manure and wastefeed washed to the tank and the sanitizers used.Regular removal and land application of sediment isrequired to avoid carry-over of solids that mayprematurely plug the disposal field. To determine thecleaning frequency, check the depth of sedimentevery few months after you begin operation.

Table 6 —Sediment Tank Capacities for Milk Center Wastes*.

No. of cows Volume (L)Settling compartment

Length (mm) Width (mm) Water depth (mm)Up to 25 2250 2060 915 122026 to 45 2700 2440 915 122046 to 65 3250 2740 990 122066 to 100 4100 2740 1065 1370

* Adapted from Canadian Farm Building Code, Associate Committee on the National Building Code, National Research Council of Canada, Ottawa.

Table 7 — Size of Underground Disposal Field for Milk Center Wastes*.

No. of cows

Length of tile trench (m)

Good subsoil drainage(Sand and gravel)

Medium subsoildrainage

(Sandy loam soil)

Poor subsoildrainage

(Silt & clay loam soil)Up to 25 30 30 4526 to 45 30 55 8046 to 65 40 80 12066 to 100 60 120 180

* Adapted from Canadian Farm Building Code, Associate Committee on the National Building Code, National Research Council of Canada, Ottawa.

28

Swine

As shown in Table 8, swine manure can behandled as either a solid, semisolid or liquid.However, the high cost and general scarcity ofbedding materials for solid manure handling systemshas led to the wide use of the generally more efficientliquid manure handling systems.

Several alternate facilities to collect and transferliquid manure are shown. The hand scrape to deepnarrow gutter system, with sluice gates to regulategravity flow through a gas trap into storage, was apopular trend in certain areas of the country;however, a new trend of gutter flushing systemsseems to be developing. Some use tipping buckets or

syphon tanks with fresh water or clear effluent forflushing, while others use the pump-agitator torecycle flush water. In the latter case, aerationdevices may be used in the surge tanks to controlodors, or a floating intake may be used to removerelatively clear effluent from the surface of detentionponds. For breeding herds, an optional system isshown using open paved runs and a covered beddedarea. If these facilities are placed on a sloping site,gravity flow can be provided from the paved runs viasurface drains or channels to storage. However, extrastorage must be provided to allow for the addedprecipitation on the exposed manure collecting andtransfer areas.

Table 8 — Manure Handling Systems for Swine.

Type of animalmanagement

Type of manure Collection and transfer Storage Removal andtransport to land

Comments

Bedded pens:see CPS plans

Solid manure Shallow gutter, gutter cleanerto elevator

Stack on curbed slab(see CPS plan M-2703)

Tractor loader tospreader to land

Only practical wherebedding is abundantand inexpensive

3025 3036 3302 3311 3312 3426 3801 3802

Manure stackrunoff

Surface drains and/or sewer Retain within storage ordrain to detention tankor earthen basin

Vacuum tanker toland

Leaching can bereduced by providingcovered storage (seeCPS plan M-2705, and add features forhandling liquidfraction)

Little or nobedding:see CPS plans

Liquid manure Hand scrape to shallow gutter,shovel (or gutter cleaner) toopening into storage

If storage site belowlevel of collectionfacilities, gravity flow to

Pump-agitator totanker to land

ORVacuum tanker toland

To exclude long-termstorage gases frombarn, provide a gastrap where manureenters storage

3025 3035 3036 3301 3302 3311 3312

ORHand scrape to deep narrowgutter, gravity flow from gutterthrough valve and gas trap intostorage

OR

large tank (see CPSplans M-3752, M-3753)or earthen storage(CPS plan M-2702)

ORprovide a continuous-running fan exhaust-ing from storage. Thisfan should be selectedto give the first stageventilation rate req’dby the swine

3428 3448 3449 3801 3802

Hydraulic flushing using freshwater or recycled liquid manure

ORThrough partially slotted floorto either:trench below, gravity flow fromtrench through gas trap intostorage

If storage site abovelevel of collectionfacilities, gravity flow toshort-term holdingtank, pump to largeabove-ground circulartank (see CPS plan3750)

ORtrench below, removal andtransfer by vacuum tanker tolong-term storage

OR continuous loop trench belowfor oxidation ditch.Effluent overflow into storage(see Oxidation Ditches, P. 34)

Open pavedruns andcovered beddedarea (optionalfor breedingherds)

Solid manure

Semi-solid manureand runoff frompaved runs andfrom manure stack

Hand scrape to gutter or opentrench, tractor scrape tostorageHand or tractor scrape tosurface drains, open channels or sewer

Stack on curbed slab

Retain within storage ordrain to detention tankor earthen basin

Tractor loader tospreader to land

Pump-agitator totanker to land

ORVacuum tanker toland

29

Poultry

Two manure handling systems for chicken broilers andheavy breeders and three systems for layers are shown inTable 9. This table includes comments on management.

Dead Bird Disposal

A number of choices are available to the poultrymanfor disposal of dead birds.• burial pits and disposal pits;• refrigerated holding and regular delivery to a

rendering plant;• incineration; and• storage in long-term holding tanks for land disposal.

Disposal facilities should be adequate to handlenormal mortality rates, estimated to be 1% each month.A large loss due to disease or power failure should not beconsidered in the design of these facilities. Such a loss

can better be handled by arranging to bury the birds or,preferably, by delivering them to a rendering plant.

In order to decide which of the four methods to adopt,a number of factors must be considered.

Burial Pits and Disposal Pits—These must be locatedand constructed to avoid polluting water supplies. Theymust not be a hazard to people in the area. This meansthat burial pits are less desirable for continual use thandisposal pits that are enclosed.

Although local water table and soil conditions must beconsidered, pits should generally be located at least 45 mfrom any well or spring used as a water supply.

Disposal pits can be made of metal, concrete or otherlocally approved material that is water-proof, and shouldbe constructed to exclude insects and rodents. Theaddition of lime helps control odors. For safety, cover pitswith tightfitting lids equipped with a locking device.

Refrigerated Holding—Some poultrymen havedeveloped a satisfactory method to temporarily store

Table 9 — Manure Handling Systems for Poultry.

Type of animalmanagement

Type of manure Collection and transfer Storage Removal andtransport to land

Comments

Floor housing withbedding (broilers,replacement pullets,breeders)

Dry litter On floor, tractor loader totruck or spreader tostorage

On floor (currentbroiler batch); interimstorage in stockpile oncurbed slab

Tractor loader tospreader to land

Stockpile storagerequired only if housingmust be cleaned andrepopulated duringperiod when manurecannot be spread

Heated floor housing,no bedding (broilers)

Dry droppings On concrete or wood floor On floor (currentbroiler batch); interimstorage in weather-proof shed

Tractor loader tospreader to land

Floor slab heated bycirculating hot water insteel or plastic piping

Ceiling suspended orfloor supported cages(layers)

Liquid manure Shallow trench, tractorshuttle scraper (for ceiling-suspended cages) or cableshuttle scraper (for floor-supported cages) to opening into storage,

OR cross conveyor to storage

Storage tank (see CPSplans M-3752, M-3753and 3750) or earthenstorage (see CPS planM-2702)

Pump-agitator totank to land

ORVacuum tanker toland

Add dilution waterduring agitation, asrequired for pumping

Semi-solid manure Shallow trench, tractorshuttle scraper (for ceiling-suspended cages) or cableshuttle scraper (for floor-supported cages) to crossconveyor to storage

Stockpile in walledstorage (see CPSplans M-2701,M-2704, M-2705)

Tractor loader tospreader to land

Avoid adding excesswater

Semi-solid manure Droppings directly into deep pit below (see CPSplan 5211)

Tractor loader tospreader to land

Avoid adding dilutionwater to minimize odor.Maximum ventilation inpit area to assist dryingof manure

Tiered cages (layers) Semi-solid manure Moveable belt to crossconveyor. Droppingboards, mechanical scraperto cross conveyor

Stockpile in walledstorage

Tractor loader tospreader to land

Avoid adding excesswater

Wire or wood slatfloor. Partial or totalfloor area (breeders)

Semi-solid manure On floor, tractor loader totruck to storage orspreader to land

On floor (currentflock); interim storagein stockpile on curbedslab

Tractor loader tospreader to land

Stockpile storagerequired only if housingmust be cleaned andrepopulated duringperiod when manurecannot be spread

Stockpile runoff Surface drain and/or sewer Retain in storage ordrain to detentiontank or earthen basin

Vacuum tanker toland

Avoid dilution water

30

dead birds in a milk-can cooler. A refrigerator orfreezer of adequate capacity for the flock also could beused. This method is limited to smaller flocks.

Incineration—Incinerators should be designed toconsume all material and should meet National FireProtection Association standards for Type 4 wastes. Inaddition, they must meet any local requirements.Some provinces require licensing. In these cases, theincinerator must be of an approved or licensed design,and each installation must be approved individually aswell.

Incinerators must be operated and maintainedcorrectly. They should be fire safe and located so thatprevailing winds carry exhaust fumes away fromneighbors.

Long-term Storage and Land Disposal—Poultrymenwho have chosen this method of disposal installprecast concrete cisterns sized to be filled over 3 to 5

years. When one tank is filled, a second tank is used,allowing an additional 3 to 5 years for completedigestion before the first tank is pumped out for landdisposal. Digestion is by enzymes or natural decay.Water is added to aid decomposition.

A good, tight-fitting and child-proof lid can bemade by cementing a milk can with the bottomremoved into the top of the cistern.

A holding tank sized to provide 550 L of tankcapacity per 1000 broilers or 2850 L per 1000 layers(same as for disposal pits) should provide 5 yearsfilling time and allow water equal to one-half of thetank capacity to be added.

Before making any final decision on method ofdisposal and starting construction, check with localauthorities to make certain the proposed method ofdisposal meets all requirements.

31

PROCESSING OF ANIMAL MANURE

Animal manure may be processed in a variety ofways to control odors, reduce water pollutionpotential, improve fertilizer value, permit energyrecovery, or reduce volume. Although manureprocessing systems are available commercially, mostare not widely used. However, because these systemsmay be valuable in certain circumstances, they arediscussed in this section to indicate what is involved.

Anaerobic Processes

Most manure management systems involve ananaerobic process of one kind or another. In fact,virtually all manure storage piles, pits and ponds arebasically anaerobic; that is, the organic materialdecomposes in the absence of free oxygen.Depending on the nature of the manure and otherenvironmental conditions, many complex reactionscan occur. The difference between an ordinarymanure storage pit, for example, and a processdefined as anaerobic is that in the latter, oneattempts to control the process and consequently thereactions that occur within its environment.

Anaerobic processes for manure managementgenerally rely on bacteria for degradation of theorganic matter. Although millions of these bacteriamay be present in as little as a thimble-full ofmanure, there are normally only two types ofmicroorganisms involved. The first type converts thefats, carbohydrates and proteins in the manure tosimpler compounds, including simple organic acidssuch as acetic and propionic acid. These so-calledacid-forming bacteria reproduce rapidly and are notsensitive to changes in their environment. Bythemselves, they and others combine to produce thehighly odorous gases and volatile compoundsassociated with ordinary manure storage units.

Processes such as anaerobic lagoons andanaerobic digesters rely on a second type of bacteria,the methane-formers, to control odors and produceenergy. The methane-producing bacteria arerelatively few and do not reproduce rapidly. They areextremely sensitive to the presence of oxygen and, ingeneral, require a special environment to functionproperly.

The end products of a properly functioninganaerobic process are methane (CH4), carbon dioxide(CO2), water, new bacterial cells, inert solids, smallamounts of hydrogen (H2) and traces of hydrogensulfide (H2S), ammonia (NH3), water vapor and othergases. Anaerobic lagoons and anaerobic digesters arethe two most widely used anaerobic processes formanure management.

Anaerobic Lagoons

Because of low initial cost and ease of operation,anaerobic lagoons have been adopted widely fortreatment of animal manure in the United States. InCanada, anaerobic lagoons have not been successfulbecause of low temperatures for much of the year.Under these conditions, the decomposition rate islow. Consequently, lagoons fill rapidly with solids thatdo not stabilize and obnoxious odors are produced.

Anaerobic lagoons should not be confused withmanure storage ponds or feedlot runoff detentionponds. Unfortunately, many anaerobic lagoons areunder designed or poorly managed. When thishappens, they cease to function as a lagoon andsimply serve as a holding basin. In spite of thedrawbacks, situations may exist where neighbors donot object and the lagoon is not a surface orgroundwater pollution hazard. In such instances,anaerobic lagoons may provide valuable flexibility inmanure management systems.

If construction of an anaerobic lagoon is beingconsidered, there are several basic requirements. Itshould be placed far enough away and downwindfrom living areas to avoid being a nuisance, belocated where there is enough space for expansionand slope is sufficient to prevent surface drainagefrom entering, and be built to permit biological actionduring as much of the year as possible. This meansthe lagoon should be as deep as possible and ofsufficient volume to handle the manure and wastewater from the entire herd at a recommended loadingrate. Recommendations for loading rates and lagoonconstruction are contained in the Canadian FarmBuilding Code 5. Consult local authorities for approvalof design before starting construction.

Anaerobic Digester

Anaerobic digesters are widely used to processdilute organic materials resulting from municipal andindustrial sewage treatment. This process has beenused successfully in warmer climates for solidsstabilization and methane gas production from animalmanure. However, as of 1979, the economicfeasibility of producing methane gas from animalmanure in North America has yet to be demonstrated.Most animal manures have potential for methaneproduction, depending on the amount and conditionof manure available and the development of a suit-able farm-size system of anaerobic digestion inCanada.

____________5 lssued by the Associate Committee on the National

Building Code, National Research Council of Canada,Ottawa.

32

Most digesters are circular, airtight structures ofvarying depth. They are equipped with mixingdevices and heat exchangers to keep manure atapproximately 35°C. Anaerobic digestion occursfrom 0 to 60°C, but gas production is severelylimited in the upper and lower ends of this range.Temperature, loading rate, mixing, retention time,alkalinity and toxicity of feed additives all affectmethane production. Other facts to consider beforeinvesting in an anaerobic digestion system includethe high cost of properly designed structures, themixing equipment and gas-control devices needed,the continual care necessary to avoid explosions, theneed to regularly feed liquid manure to the digesterand supervise the digester operation, the storageand use of the biogas produced, and the storage anduse of the digested liquid manure.

A successfully operated anaerobic digesterproduces gas consisting of about 60 to 70%methane and 40 to 30% carbon dioxide. Thismixture is sometimes called biogas. Research at theUniversity of Manitoba and elsewhere has shown itis possible to produce heating energy equivalent to1 to 2.4 L of fuel oil per day, from each 1,000 kg ofanimal liveweight, depending on the species. Thepotential for electricity generated from biogas issomewhat less, about 2.6 to 6.2 kWh per day foreach 1,000 kg of liveweight, again depending on thespecies. Research also has shown that poultrymanure normally will produce more biogas per unitliveweight than manure from swine, dairy or beef.However, because of the dilution needed to guardagainst ammonium inhibition of the bacteria, moredigester capacity is necessary. The result is thatbiogas from poultry manure per unit digestercapacity is about the same as for other species.Manure that lies for more than a few hours on openfeedlots or concrete aprons, or that has bedding orother debris mixed with it, will not be as effective asliquid manure collected under cages or slotted floors,or by flushing gutters.

In anaerobic digestion, approximately 1% of theoriginal nitrogen in the manure is lost while virtuallyall of the phosphorus and potassium are retained.Reports that digested manure is better fertilizer thanregular liquid manure are based on digested manurehaving a larger percentage of inorganic nitrogen thatis readily available to plants. However, digestedmanure must be incorporated quickly during landapplication to prevent large losses of ammonianitrogen. Therefore, we can only say for certain that,with proper management, anaerobically digestedmanure is at least as good as regular manure.

Of the volume of manure that enters a digester,97 to 98% will leave the digester and presumablymust be hauled to the field. However, depending onthe dilution necessary for digestion, more may haveto be hauled. Poultry manure, for example, needs nodilution if hauled as a solid manure, but if digested,the dilution water would increase the original volume

about four times.Studies in Canada have shown that, on an

annual basis, about 35% of the gross energyproduced by a well-insulated and properly-operatedanaerobic digester is used to heat and mix theincoming manure, and replace heat losses. Thepercentage of gross energy that must be returned tothe digester depends on the time of year. DuringJanuary about 46% is used to run the digester whilein July and August less than 27% is needed.

Three realistic options exist for using biogas onanimal production farms: use it directly for cooking,lighting, space heating, water heating, grain dryingor gas-fired refrigerating and air conditioning;transform it into electricity by burning it in an enginethat turns a generator; or vent it to the atmosphere.The best use depends on the amount and type ofseasonal energy needed by a particular farm and thecomparative cost of each form of energy from othersources. At present, the use of biogas as a fuel forcars, trucks and tractors is impractical because of itslow energy per unit volume. This low energy contentreduces the distance that can be travelled or thework that can be done with the biogas contained ina reasonably-sized tank.

The cost of an anaerobic digestion system on afarm will depend partly on the degree of automationdesired and thus the complexity of the system, theamount of dilution necessary and therefore the sizeof the digester, the investment in addition to thenormal manure handling costs, and the intended useof the biogas. Other factors that influence costs arethe structural materials used for the digester, theamount of insulation necessary, the bearing capacityof the soil, the location of the water table and thelocation of the digester with respect to the barn.Some farmers may be able to reduce costs byobtaining various components of the system throughsales and salvage yards. They also may choose tobuild the system themselves and avoid direct laborcosts. Some may prefer to use additional labor tooperate the system instead of purchasing automaticcontrols, decreasing the initial cost but increasingthe operating cost. Therefore, each situation mustbe examined to determine its economic justification.Much progress has been made in research anddevelopment of anaerobic digesters for farms.However, anaerobic digestion cannot berecommended at present for use with normal animaloperations.

Aerobic Processes

Aerobic decomposition occurs when a dilutemixture of organic wastes and water is supplied withdissolved oxygen. Under these conditions, aerobicbacteria use the organic matter as a food source inbiochemical and oxidation reactions to produce new

33

bacterial cells, carbon dioxide and water as theprimary end products. In practical systems, all of theorganic matter will not be decomposed aerobicallyand accumulation of these stable solids along withfixed solids will result.

Compared to domestic sewage, animal manurecontains extremely high amounts of carbonaceousmaterial and nutrients. Consequently, treatment ofanimal manures with the hope of obtaining effluentsuitable for disposal in a stream or lake is noteconomically feasible today. However, in manyinstances partial treatment of liquid animal manuresmay be used to control odors or to reduce thenitrogen content of the material. Oxidation ditchesand aerated lagoons have been the most successfulmethods of treating liquid animal manures.Composting (an aerobic process) can be used tostabilize solid manure.

Oxidation Ditches

An oxidation ditch is an open channel pit shapedlike a racetrack in which a paddle, brush-type rotoror an air pump supplies oxygen to the liquid manureand keeps the liquid contents of the ditch incirculation. Oxidation ditches have been employedunder slotted floors in swine, beef, and dairyconfinement buildings and under caged layersystems for poultry. The principal advantage of theoxidation ditch is its capability to minimize odors.Construction and installation costs can be high andmaintenance may be a problem.

Foaming of the ditch contents is sometimesencountered during start-up or when the ditch isoverloaded. Antifoam agents, water spray, or smallamounts of oil may be used to combat foaming. Anoxidation ditch should be started gradually byinitially filling the ditch with tap water. A rotorshould not be started in a ditch that contains liquidmanure more than a few days old. The oxidationditch works well in cold climates provided themajority of the ditch is within the confinementfacility.

A properly designed, installed, and operatedoxidation ditch can reduce odor productiondramatically. However, it does not eliminate theneed for manure management. In most cases arelatively odor free effluent still must be stored andreturned to the land. In some cases the volume ofliquid effluent may be reduced; in others it may beincreased depending upon the type of manure, wateruse, and evaporation within the facility. Engineeringadvice on the design of an oxidation ditch should besought prior to investment so that loading rates androtor capacity, etc., can be matched to the individualoperation.

Aerated Lagoons

There are two types of aerated lagoons: thenaturally-aerated lagoon (sometimes called anaerobic lagoon or an oxidation pond) and themechanically-aerated lagoon.

Naturally-aerated lagoons are generally shallow(1 m) basins in which bacteria and algae areexpected to purify the organic matter of the manure.Lack of a long, warm summer in Canada and theease with which it is possible to overload naturallyaerated lagoons has limited their success for animalmanure management. Mechanically-aerated lagoonsoperate on the same biological principles as theoxidation ditch. However, the aerator is generally apump or a blower that is often designed to float inplace on the lagoon.

Several disadvantages exist with mechanically-aerated lagoons when compared to an oxidationditch. Manure must be moved to the lagoon, thelagoon will require more space, if not maintained itwill be an eyesore, and it is subject to freezing.Advantages usually include flexibility with respect toexisting buildings, lower initial costs, and lessconcern for foaming or equipment failure. If properlydesigned and operated, a mechanically-aeratedlagoon will control odors. Liquid and solids will haveto be removed periodically and measures would haveto be taken to start the aerator as soon as possiblein the spring to prevent growth of odor-producingbacteria. As is the case with the oxidation ditch,engineering advice should be sought beforepurchasing a fixed or floating aerator.

Composting

Composting is a relatively fast aerobic process inwhich organic matter is broken down by bacteria andfungi to produce a dark-colored humus. Aeration isaccomplished by mixing solid or semisolid manurewith a mechanical scraper, windrower, or rotarydrum. This process is self-heating to about 60° Cand with moderate shelter can be operatedyear-round. Stable compost can be produced inabout 10 days provided a carbon to nitrogen ratio ofapproximately 25:1 and a moisture content ofaround 50% are maintained in the heap. Since freshanimal manure contains more nitrogen and moisturethan is desirable for good composting, choppedstraw may be used to improve the compost. Goodcomposting requires daily mixing and should not betried without adequate labor, time, and equipment.Commercial compost markets are limited and, aswith dried manure, relatively few animal operationsin North America have successfully sold these asby-products.

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Dehydration

Moisture removal by the addition of heat is moreapplicable to undiluted poultry manure than to othertypes. It is the highest in nutrients, the driest tobegin with, and can be dried further in the poultryhouse by ventilation using surplus heat produced bythe flock or heat from outside air.

Dehydration is desirable for odor control,improved handling characteristics and weightreduction. Manure dried to 15% moisture content orless stores well with little odor and doesn't attract

many flies. Commercial manure drying for marketinghas had limited success in North America becausedemand in any given area is small.

Incineration

Incineration of animal manure has failed as afeasible manure management alternative. Air pol-lution due to odors and particulate matter, the factthat 10 to 30% of the initial dry matter remains asash, and high costs are the primary reasons for thisfailure.

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Appendix 1. Properties of the Principal Manure Gases and their Physiological Response on Adult Humans1.

Gas Specificgravity2

Odor Color Affinityfor water

Limits of inflammability3

(% by volume)Threshold

limit value 4

(ppm) 5

Excursionfactors

Time-weighedaverage limit 7

(ppm)

Gas concentration (ppm)and physiological response

Lower Upper

Ammonia(NH3)

0.6 Sharp,pungent

None Highlysoluble

15.5 27.0 25 1.5 37.5 IRRITANT

5-50 — least detectable odor100-500 — Irritations to mucous

surfaces in 1 hour400-700 — immediate irritation of

eyes, nose and throat2,000-3,000 - severe eye irritation,

coughing, frothing atmouth, could be fatal

5,000 — respiratory spasm, rapidasphyxia, may be fatal

10,000 — rapidly fatalCarbondioxide

1.5 None None Moderatelysoluble

— — 5,000 1.25 6 250 ASPHYXIANT20,000 — safe

(CO2) 30,000 — increased breathing40,000 — drowsiness, headaches60,000 — heavy, asphyxiated

breathing300,000 — could be fatal (30

minute exposure)Hydrogensulfide(H2S)

12 Offensive,rotten

egg smell

None Highlysoluble

4.3 45.5 10 2 20 POISON

0.01-0.7 — least detectable odor

3-5 — offensive odor10 — eye irritation20 — irritation to mucous

membranes and lungs50-100 — irritation to eyes and

respiratory tract (1 hourexposure)

150 — olfactory-nerveparalysis, fatal in 8-48hours

200 — dizziness (1 hour),nervous systemdepression

500-600 — nausea, excitement,unconsciousness,possible death,(30 minutes)

700-2,000 - rapidly fatalMethane(CH4)

0.6 None None Slightlysoluble

5.0 15.0 — — — ASPHYXIANT

500,000 — headache, nontoxic

1 Source. Nordstrom, G.A and J.B. McQuitty 1976. Manure gases in the animal environment — a literature review Research Bulletin 76-1, Departmentof Agricultural Engineering, University of Alberta, Edmonton, Alberta 80 pp. 115 ref.

2 Specific gravity: the ratio of the weight of pure gas to standard atmospheric air, per unit volume If value is less than 1 0, the gas is less dense than air;if greater than 1.0, it is more dense than air.

3 The range within which a mixture of the gas with atmosphere air can ignite or explode in contact with a flame or spark. Source: R C Weast (Ed ). 1973-74. Handbook of Physics and Chemistry, 54th Edition. CRC Press, Cleveland.

4 Threshold limit value (TLV) represents conditions under which nearly all workers may be repeatedly exposed for an 8-hour day and 40-hour work weekwithout apparent adverse effects.

5 Parts per million of gas in atmospheric air; to convert gas concentration to percent by volume, divide ppm by 10,000.

6 Excursion factor defines the magnitude of the permissible excursion above the TLV.

7 Time-weighed average (TWA) limit defines the maximum concentration permitted for a short period. TLV multiplied by the excursion factor equals TWA.

NOTE: When two or more hazardous gases are present, and in the absence of information to the contrary, the effects of the different gases should beconsidered as additive; that is, if the sum of C1/T1 + C2/T2 + .......... Cn/Tn exceeds unity, then the TLV of the mixture should be considered asbeing exceeded.C = observed atmospheric concentration and T = corresponding TLV for each gas, n.

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Appendix 2 — Volume of Dilution Water Required to Change the Moisture Content of Manure.

EXAMPLE: To bring manure that has 75% moisture content up to 95% moisture, 4 m3 ofwater must be added to each m3 of manure.

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