1. Pennsylvania Department of Environmental Protection
      1. Harrisburg, Pennsylvania November 15, 2001
      3. Environmental Benefits to Pennsylvania
      4. Economic Benefits to Farmers
      5. Damage Mitigation
      7. Permits for Concentrated Animal Feeding Operations
      8. Individual and General Permits
      9. Obtaining Permit Applications and Information
      10. NUTRIENT
      12. Required CAO Plans
      13. Compliance Plans
      14. Voluntary Plans
      15. Preemption of Local Ordinances
      20. Manure Storage Freeboard Requirements
      21. Conditions That Require Permits or DEP Approval
      2. DEATH
      2. SURFACE MAY
      1. PLANNING
      2. DESIGN
      2. FLY SPECIES

361-0300-001 / November 15, 2001
Pennsylvania Department of Environmental Protection

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Commonwealth of Pennsylvania, Harrisburg, Pennsylvania
Department of Environmental Protection

Manure Management for Environmental Protection
361-0300-001 / November 15, 2001 / Page i
: 361-0300-001
Manure Management for Environmental Protection
November 15, 2001
25 Pa. Code Chapter 91, Section 91.36
Provides practices for livestock and poultry operations under which DEP approval
or a permit is not required. Also, describes related requirements under the Nutrient
Management Act and the Pennsylvania Strategy for Concentrated Animal Feeding
Describes technical practices for all livestock and poultry operations in
The revision of this section of the Manure Management Manual updates and
clarifies current requirements for livestock and poultry operations and provides a
description of DEP approved practices.
The policies and procedures outlined in this guidance document are intended to
supplement existing requirements. Nothing in the policies or procedures shall
affect regulatory requirements. The policies and procedures herein are not an
adjudication or a regulation. There is not intent on the part of DEP to give the rules
in these policies that weight or deference. This document establishes the
framework, within which DEP will exercise its administrative discretion in the
future. DEP reserves the discretion to deviate from this policy statement if
circumstances warrant.
27 pages
Vol. 35, Tab 1

Manure Management for Environmental Protection
361-0300-001 / November 15, 2001 / Page ii
Dr. Douglas Beegle
Pennsylvania State University
David Bingaman
Pennsylvania Department of Agriculture
Todd Brajkovich
Perry County Conservation District
Leigh Cohen
Pennsylvania Department of Environmental Protection
Mohammad Farooq
Pennsylvania Department of Environmental Protection
Lyle Forer
Pennsylvania Department of Agriculture
Douglas Goodlander
State Conservation Commission Staff
Dr. Robert Graves
Pennsylvania State University
Thomas Juengst
Pennsylvania Department of Environmental Protection
Cedric Karper
Pennsylvania Department of Environmental Protection
Milt Lauch
Pennsylvania Department of Environmental Protection
Michael Lovegreen
Bradford County Conservation District
Dr. Dennis Murphy
Pennsylvania State University
Timothy Murphy
Natural Resources Conservation Service
Larry Nygren
Pennsylvania Department of Environmental Protection
Walter Peechatka
Penn Ag Industries
Leon Oberdick
Pennsylvania Department of Environmental Protection
Michael Sherman
Pennsylvania Department of Environmental Protection
Carol Young
Pennsylvania Department of Environmental Protection

Manure Management for Environmental Protection
361-0300-001 / November 15, 2001 / Page iii

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This publication supersedes all previous
Manure Management for Environmental Protection
published by the Commonwealth of Pennsylvania, Department of Environmental Protection (DEP). Due
to changes in recommendations and practices, copies of the previous versions of this booklet should be
discarded. The current publication consists of a booklet entitled
Manure Management for
Environmental Protection,
as well as eight technical supplements. A complete list of titles and where
they may be obtained is given at the back of this publication.
This manual was developed in consultation with technical specialists of the USDA Natural Resources
Conservation Service and the Cooperative Extension of the Pennsylvania State University. Additional
input and review were provided by many individuals including Agricultural Advisory Board to DEP,
DEP personnel, members of state farm organizations, and representatives of conservation districts.
The Manure Manual for Environmental Protection and its supplements provide practices that comply
with DEP regulations concerning animal manures. Some farmers may have operations that are
Concentrated Animal Operations under the Nutrient Management Act Regulations, or Concentrated
Animal Feeding Operations under the Pennsylvania strategy for meeting federal requirements. These
farmers would follow requirements in addition to those found in this manual. Farmers who do not
follow these requirements and the practices in this publication are required to obtain DEP approval or a
water quality permit.
Commonwealth of Pennsylvania
Department of Environmental Protection
Office of Water Management
Harrisburg, Pennsylvania
November 15, 2001

Manure Management for Environmental Protection
361-0300-001 / November 15, 2001 / Page iv

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Legal and Management Aspects of Animal Manures—
Safety and Emergency Response for Manure Management
Planning, Design and Construction of Manure
Management Systems—MM3
Operation and Maintenance of Manure Management
Manure Management Strategies to Control Flies—MM5
The Pennsylvania Department of Environmental Protection (DEP) publishes a manual containing guidelines for manure
management. The entire collection of eight individual booklets is called the MANURE MANAGEMENT MANUAL.
Copies of this manual are available from DEP Regional offices.
Prepared and reviewed with the assistance of agricultural and technical specialists working with the Pennsylvania Department
of Environmental Protection. This is a revision to the 1986 version of the manual edited by Robert E. Graves.
Graphic Design:
James McClure
Sookyoung Cho

Manure Management for Environmental Protection, Document MM1
361-0300-001 / November 15, 2001 / Page 1

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Many Pennsylvania farmers have been practicing good
stewardship to conserve the Commonwealth's agricultural
resources. The potential for environmental problems
resulting from all sources including livestock and poultry
operations has increased as the economy has grown and
development has occurred. The Department of
Environmental Protection (DEP) and others believe it is
easier to prevent pollution or other environmental
problems than to correct them after they occur.
This manual describes normal farming operations and
their relationship to sound environmental protection
practices identified by DEP. It illustrates how
environmental protection can be integrated into farming
operations. It may be used by farmers, DEP personnel,
and others interested in agricultural operations and the
Science and careful observation can often determine
whether a given farm practice is likely to cause pollution
or other environmental problems. Water quality will be
adversely affected if manure runs into streams or drainage
ditches as a result of land application, spillage, storage
overflow, or deliberate dumping. Nutrients in manure
applied when there is no growing crop or at rates that
greatly exceed crop fertilizer requirements are more likely
to leach into ground water or be carried away with runoff
water and eroded soil. Excessive manure application may
also result in decreased crop yields.
Manure management problems can arise when livestock
are added to a farm without increasing the land base. This
may result in excessive manure production in relation to
the nutrient needs of the land utilized for crops. Farmers
who purchase a high percentage of their livestock feed are
more likely to have insufficient land to utilize the manure
safely and effectively. In some instances, it may be easier
or more efficient to reduce inputs. In general, farmers
who grow all or most of the feed consumed by their
animals probably have sufficient cropland for well-
managed manure application.
If manure production exceeds crop requirements,
arrangements must be made to move excess manure to
other cropland or use it for other beneficial purposes.
Each farmer is responsible for providing a sound manure
management system that provides adequate protection for
the environment. Sound management involves proper
design, construction, maintenance and operation of the
manure handling system, and lessens the potential costs to
the public for addressing pollution problems. When
necessary, it may include extra storage, spare parts,
backup equipment, or contingency plans for equipment
breakdown or for extraordinary weather conditions.
The reasons for developing a sound manure management
program include:
environmental benefits to Pennsylvania
economic benefits to the farmer
compliance with laws and regulations concerning
environmental quality
limited liability protection
better neighbor relations
Manure management involves setting up an effective
system to handle and utilize manure produced by
livestock. All situations described in this manual involve
returning the manure to cropland as part of a
comprehensive crop management program, including
regular soil and manure testing. If too much manure is
being produced for available land, long-range solutions to
solve this problem must be implemented. These involve
moving the manure to a nutrient-deficient area, reducing
nutrient inputs or using a non-crop utilization system or
This manual does not attempt to cover specialized systems
designed to market manure or utilize it as a fuel, feed, or
special fertilizer. Since these systems are usually site
specific, interested farmers should seek competent advice
to ensure that their methods are environmentally sound.
Practices not identified in this manual must be approved
by DEP.
Environmental Benefits to Pennsylvania
Livestock manure is extremely beneficial for plant growth,
improving soil structure, and increasing soil fertility
levels. If improperly handled, however, it can be an
environmental problem resulting in contaminated runoff
into surface streams and leaching into ground water.
Severe cases can increase nitrogen, phosphorus or salt
levels in surface or ground water and runoff can cause
pathogen contamination, fish kills, and odor and taste
problems. Responsible manure management can provide
farmers with economic benefits while also protecting the

Manure Management for Environmental Protection, Document MM1
361-0300-001 / November 15, 2001 / Page 2
Economic Benefits to Farmers
When applied in the proper amounts at the appropriate
times, livestock manures can provide some, if not all, of
the nutrients required for many crops grown on
Pennsylvania farms. A manure-handling system also can
improve labor and equipment utilization. Manure usually
is applied to cropland owned or controlled by the
livestock owner. In some situations, the owner may
choose to transfer manure to others for use on cropland,
gardens, and nurseries. In certain situations, manure may
also be recycled as a fuel substitute or additive or as part
of a refeeding program.
Manure applied to farmland has the potential for
improving crop production and soil productivity. A 50-
cow dairy herd and associated young stock produce
approximately 1,400 tons of manure annually. Depending
on storage and handling methods, this manure contains
approximately 15,000 pounds of nitrogen, 6,000 pounds
of phosphate, and 12,000 pounds of potash. These
nutrients can be effectively used as a fertilizer for growing
plants. The organic matter and other trace elements also
may improve soil productivity substantially. Farmers who
successfully manage this quantity of material to gain
maximum crop production save a considerable amount of
money on purchased fertilizer. Those who do not manage
this nutrient supply efficiently may reduce crop
production levels, increase fertilizer bills, and cause
pollution. This pollution may effect regional surface and
ground water, as well as, the farmer's own water supply.
It may also cause odor and air pollution problems.
Compliance with Laws and Regulations
Discharges to surface or ground water are regulated by
various federal and state laws so that manure does not
pollute surface or ground water. Animal manures or
runoff discharged into waterways are a pollutant and are
considered under Pennsylvania law to be sewage. Items
classified as sewage must be handled and disposed of
under the requirements of state water pollution control
laws and permitting procedures.
Damage Mitigation
Implementation of an approved plan under the Nutrient
Management Act is a mitigating factor in any civil action
for penalties or damages resulting from the Clean Streams
Law. A civil action for penalties or damages will give
appropriate consideration to an operator who is fully and
properly implementing a nutrient management plan under
the Act.
Better Neighbor Relations
Many problems can be solved or minimized by contacting
affected neighbors. This can be done to obtain
preferences that will lessen potential conflicts prior to
field activities or operation changes. Introducing yourself
may help later if problems do arise. When problems do
occur, direct contact can increase understanding and help
to focus resolution efforts or eliminate confusion.
Permits for Concentrated Animal Feeding
Pennsylvania DEP has developed a permitting system to
cover all operations that are considered to be
Concentrated Animal Feeding Operations (CAFOs). The
specific requirements are contained in the
“Final Strategy
for Meeting Federal Requirements for Controlling the
Water Quality Impacts of Concentrated Animal Feeding
CAFO is a term that originated from federal
regulations. The State CAFO program requires all
CAFOs to obtain Individual or General National Pollutant
Discharge Elimination System (NPDES) Permits. In
Pennsylvania, these broad categories are CAFOs:
?? Operations that have greater than 1000 animal
equivalent units
?? Operations with 301 to 1000 animal equivalent units
that are also Concentrated Animal Operations
(CAOs) under the Pennsylvania Nutrient
Management Regulations
?? Any operation with a direct discharge to surface
waters during a storm event less than a 25 year, 24
hour storm
An animal equivalent unit (AEU) is one thousand pounds
of animal weight as determined by the method used in the
Pennsylvania Nutrient Management Regulations. CAOs
are operations with greater than 2 AEUs per acre of land
suitable for manure application. Exact definitions for
AEUs and CAOs are contained in the Pennsylvania
Nutrient Management Regulations.

Manure Management for Environmental Protection, Document MM1
361-0300-001 / November 15, 2001 / Page 3
No CAFO Permit
New or Expanded Farming Operation
>1,000 AEUs or Existing Farming
Operation >1,000 AEUs in Special
Protection Watershed or a CAO >300
AEUs in Special Protection Watershed
or Farming Operation with direct
discharge to surface waters*
Existing CAO >300 AEUs or Existing
Farming Operation >1,000 AEUs or New
or Expanded CAO with 301-1,000 AEUs
90 Days from
60 Days after
Receipt of
Notice of Intent
Nutrient Management Plan
PE Certification for new manure storage facilities
E&S Control Plan
NPDES Stormwater Permit
Individual NPDES Permit
General NPDES Permit
Greater than 1,000 AEUs
PPC Plan
Landowner/Broker Agreements
New or Expanded Manure
Storage Facility
WQP Part II Permit
P.E. Certification for
Existing Manure
Storage Facility
No Additional
*Any facility with an actual discharge
to surface waters during a storm
event less than a 25 year/24 hour
storm must obtain an individual

Manure Management for Environmental Protection, Document MM1
361-0300-001 / November 15, 2001 / Page 4
Individual and General Permits
All CAFOs in Pennsylvania must obtain coverage under a
NPDES CAFO Permit. There are two types of NPDES
Permits – Individual and General. The following
operations must operate under an Individual NPDES
?? Existing operations with more than 1,000 AEUs and
in a Special Protection Watershed
?? New or expanding operations with more than 1000
?? New, expanding, or existing CAOs with more than
300 AEUs located in a Special Protection Watershed
?? Any operation with a direct discharge to surface
waters during a storm event less than a 25 year, 24
hour storm
The following operations that are not in Special Protection
Watersheds must operate under a General NPDES Permit:
?? Existing CAOs with more than 300 AEUs
?? Existing operations with more than 1000 AEUs
?? New or expanded CAOs with 301 to 1000 AEUs
An operation that existed on or before January 16, 1998 is
considered to be an existing operation. Permit deadlines
and conditions are located in Chapter 92 of the
Pennsylvania Clean Streams Law regulations.
A General NPDES permit is contingent upon approval of
the Nutrient Management Plan by the conservation district
or the State Conservation Commission. Any CAFO may
choose Individual Permit rather than General Permit
coverage. Also, the manure storage and handling system
must be in compliance with the PA Technical Guide
Required Permit Elements
The following, where applicable, are required for all
?? An approved Nutrient Management Plan under the
Pennsylvania Nutrient Management Regulations
?? Implementation and availability of the Chapter 102
Erosion and Sedimentation Control Plan for
earthmoving activities including plowing and tilling
where manure is applied
?? A NPDES Permit for stormwater discharges for earth
disturbance of five acres or more
?? Publication in the Pennsylvania Bulletin of permit
applications and final actions
?? A newspaper notice for all new operations applying
for a CAFO permit
?? A 30-day public comment period for issuance of an
Individual CAFO Permit
Self Inspection is required of all CAFOs with
more than 1000 AEUs which includes submitting
quarterly reports to DEP; others retain reports
?? A public hearing for CAFO permits proposed in
Exceptional Value Watersheds
In addition to the above required elements, all CAFOs
with more than 1000 AEUs must meet the following
permit requirements:
?? A Pennsylvania Water Quality Management Part II
Permit for a new or expanded manure storage facility
prior to construction and operation, which includes
storage leak detection and monitoring and design and
post-construction certifications by a Pennsylvania
registered professional engineer, and prohibits
locating in wetlands or the 100-year floodplain
?? For existing manure storage facilities, a certification
from a professional engineer that the facility is
designed and being operated in accordance with the
Pennsylvania Technical Guide
?? In addition to the Contingency Plan for manure which
is part of the Nutrient Management Plan, a
Preparedness, Prevention and Contingency (PPC)
Plan to address the accidental release of all chemicals
related to operation of the CAFO
?? A signed agreement between the CAFO exporting
manure and the importer where the manure is to be
applied or the broker to insure that the manure will be
applied in an environmentally sound manner.
Receiving sites must be covered by a Nutrient
Management Plan or a Nutrient Balance Sheet
Obtaining Permit Applications and Information
This is a general description of the type of farming
operations in Pennsylvania that are required to obtain
CAFO permits and the required permit elements. Issuance
of a permit may be appealed within 30 days of the notice
in the PA Bulletin. Contact your DEP Regional Office,
Water Quality Management Program to obtain a permit
application or more specific information.
Appropriate nutrient management techniques are
described in the “Field Application of Manure”
supplement to this manual. Certain large and/or densely
populated animal operations are required under the
regulations to have detailed nutrient management plans as
described below.
In 1993, the Pennsylvania Nutrient Management Act
became law and created a legal framework for addressing

Manure Management for Environmental Protection, Document MM1
361-0300-001 / November 15, 2001 / Page 5
nutrient management for certain operations in
Pennsylvania. On October 1, 1997, the Nutrient
Management Regulations (Title 25, Chapter 83.201
.) became effective. These regulations provide the
details and requirements for the development and
implementation of Nutrient Management Plans under the
Nutrient Management Act. The plans cover the following:
?? Farm identification
?? Plan summary
?? Best management practices schedule
?? Nutrient application
?? Excess manure utilization
?? Manure management including barnyard areas
?? Stormwater runoff control and
?? Manure storage facilities
All plans required for CAFOs or under the Nutrient
Management Regulations must be developed by Nutrient
Management Specialists certified by the Pennsylvania
Department of Agriculture and approved by a delegated
conservation district or the State Conservation
Commission. Nutrient Management Plans are required for
all CAFO permits in Pennsylvania.
Required CAO Plans
The Pennsylvania Nutrient Management Regulations
require an operation classified as a Concentrated Animal
Operation (CAO) to submit a complete Nutrient
Management Plan for approval to a delegated County
Conservation District or the State Conservation
Commission. A CAO plan must be implemented
according to the schedule in the approved plan. The plan
submission requirements for different categories of CAOs
?? CAOs in existence on or before October 1, 1997 must
have nutrient management plans
?? CAOs that came into existence after October 1, 1997
must submit plans prior to commencement of manure
?? Operations that become CAOs because of expansion
of animal units or loss of suitable land for manure
application must submit plans within three months of
the operation change
CAOs are defined by the regulations as operations with
greater than 2 Animal Equivalent Units (AEUs) per acre
of land suitable for manure application. An AEU is one
thousand pounds of animal weight as determined by the
Nutrient Management Regulations.
Compliance Plans
An operation found to be in violation of the Pennsylvania
Clean Streams Law may be required to submit and
implement a Nutrient Management Plan that meets the
requirements for CAO plans. Additional information may
be required by the DEP to address specific concerns
related to the Clean Streams Law.
Voluntary Plans
Any operation that is not a CAO may voluntarily submit a
Nutrient Management Plan for approval to a delegated
County Conservation District or the State Conservation
Commission. Operations with voluntary plans will only
receive the benefits of the plan to the extent that the plan
is implemented. Benefits may include limited liability
protection, operational efficiency, pollution prevention,
and financial and technical assistance.
Preemption of Local Ordinances
Section 17 of the Nutrient Management Act contains
provisions pre-empting certain local ordinances.
Additional information on nutrient management planning
may be obtained from delegated County Conservation
Districts. Also, state agencies that are assigned to assist
the program can provide specific program information.
Responsibility for implementing the Nutrient Management
Regulations rests with the State Conservation
Commission. The Commission staff including assigned
Departments of Environmental Protection (DEP) and
Pennsylvania Department of Agriculture (PDA) staff
assists with program implementation. DEP Bureau of
Water Quality Protection staff assists with program
monitoring and delegation to County Conservation
Districts. PDA Bureau of Plant Industry staff administers
the Nutrient Management Specialist certification program,
and assists with program outreach and implementation. A
guidance manual titled
Pennsylvania’s Nutrient
Management Act Technical Manual
provides details to
explain and implement the technical requirements in the
Nutrient Management Regulations. The technical
guidance manual can be obtained from the PDA Bureau of
Plant Industry.

Manure Management for Environmental Protection, Document MM1
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The manure management system must follow the practices
in this manual or obtain DEP approval or permit. If
applicable, the approved practices must work in
conjunction with the approved and implemented plan
under the Nutrient Management Regulations, Title 25,
Chapter 83. The regulations under Pennsylvania Clean
Streams Law, Title 25, Chapter 91, Sections 91.33
through 91.36 cover the following:
?? Freeboard requirements (i.e., additional storage
volume above the maximum design capacity) for
manure storage facilities
?? The authority for DEP to require reports or plans on
the location, size, construction and contents of
manure storage facilities, or for water polluting
?? Obtaining permits for certain wastewater
impoundments and manure storage facilities
?? Design, construction and operation requirements for
all manure storage facilities
?? Registered professional engineer certification for the
design and construction of existing manure storage
facilities at existing animal operations with over
1,000 AEUs
?? CAFOs with over 1,000 AEUs and operators with
plans under the Nutrient Management Act must
obtain registered professional engineer certification
that the design and construction of new or expanded
liquid and semi-solid manure storage facilities
comply with the standards of the PA Technical Guide
?? DEP approval or permits for manure storage facilities
that do not follow the
Manure Management Manual
for Environmental Protection
and the
Technical Guide
?? DEP approval or permits for land application of
manure that does not follow the
Manure Management
Manual for Environmental Protection
?? The requirement to prevent, address and report water
pollution incidents
When necessary, refer to the appropriate requirements in
the Chapter 91 regulations or the supporting guidance
documents. In addition, Chapter 102 requires operations
with earthmoving activities to have an Erosion and
Sedimentation Control Plan, and an NPDES permit for
earth disturbance of five acres or more. You may also
obtain information from the DEP Regional Office, Water
Quality Management Program.
Manure Storage Freeboard Requirements
?? All agricultural operations with more than 1,000
AEUs must provide at least a 2-foot freeboard for
new or expanded waste storage facilities at all times
?? An agricultural operation with 1,000 AEUs or less
must provide at least a 12-inch freeboard for waste
storage ponds and at least a 6-inch freeboard for
waste storage structures
?? Agricultural operations with more than 1,000 AEUs
must provide at least 12 inches of freeboard on
existing waste storage ponds and 6 inches on existing
waste storage structures (as described in the PA
Technical Guide) and these facilities must be certified
by a Pennsylvania registered Professional Engineer to
be adequate
Conditions That Require Permits or DEP
?? Agricultural operations classified as CAFOs must
obtain Individual or General NPDES Permits
?? Existing, new or expanded CAOs with 301-1,000
AEUs and not in special protection watersheds must
apply for a General NPDES Permit by February 28,
?? CAOs with greater that 300 AEUs and in Special
Protection Watersheds must obtain Individual
NPDES Permits
?? New or expanded agricultural operations with more
than 1,000 AEUs must obtain an Individual NPDES
?? Agricultural operations with more than 1,000 AEUs
that install new or expanded manure storage facilities
must obtain Water Quality Management Part 2
?? Existing operations with more than 1,000 AEUs must
obtain General NPDES Permits
?? Design, construction and operation of manure storage
facilities not consistent with the
Manure Management
Manual for Environmental Protection
and the
Pennsylvania Technical Guide
?? Land application of manure not consistent with the
Manure Management Manual for Environmental
Other Requirements
Some farmers may have operations that are Concentrated
Animal Operations under the Nutrient Management Act
Regulations, or Concentrated Animal Feeding Operations
under the Pennsylvania strategy for meeting federal
requirements. These farmers would follow requirements
previously mentioned in this manual (Contact the nearest
DEP regional office for additional information).
Regardless of whether a permit is required, farmers are

Manure Management for Environmental Protection, Document MM1
361-0300-001 / November 15, 2001 / Page 7
always responsible for any pollution of surface or ground
water caused by their farming operations.
In addition to the Clean Streams Law and Nutrient
Management Act, various local, state, and federal laws
also may apply to manure handling, including:
Federal Clean Water Act
Pennsylvania Dam Safety and Encroachments Act
Pennsylvania Solid Waste Management Act
Pennsylvania Safe Drinking Water Act
Pennsylvania Sewage Facilities Act
Pennsylvania Air Pollution Control Act
1956 Pennsylvania Fertilizer Law
Right to Farm Act
Pennsylvania Local ordinances
Various liquid and non-liquid systems can be used
successfully to handle, store, and utilize or dispose of
manure. These are affected by type of animal, housing
system, amount and location of available land, housing
system location, manure utilization method, and personal
Pasturing livestock is one of the simpler forms of manure
management. The livestock spread manure, with little
effort required by the farmer. Stream access ramps and
fencing systems can be used to lessen stream degradation.
A poultry producer with a cage layer house has a much
different situation. Manure may fall directly from the
birds to a storage area underneath the cages, or it may
accumulate on scraping boards under cages, which are
regularly scraped to a cross conveyor which carries
manure to a storage area or to spreaders. If there is no
bedding or other material to soak up liquid portions of the
manure, storage and handling systems must be planned
and managed accordingly. In a high-rise house, the
ventilation and watering systems are managed to promote
maximum drying so material can be handled with
conventional front-end loaders. A scraper-board system,
on the other hand, is more efficient when handling wet
manure or for a liquid system outside the house.
Various forms of manure can be produced on dairy farms.
Bedded/loafing sheds used for dry cows and heifers may
require handling only a few times a year. The waste
produced is usually hard-packed combination of bedding
and dried manure. From a free-stall housing system or
paved feeding area, the produced manure may range from
a semisolid to a liquid. With semisolid or liquid manure,
scraping and handling equipment must be designed to
contain the more free-flowing manure and, in some cases,
treat it as a pumpable liquid. Feeding and resting yards
also must be able to handle runoff without washing
manure into streams or lakes. In a tie-stall or stanchion
barn, bedding is usually added to the manure. This
produces a more solid, stackable material.
Most modern hog and veal confinement facilities have a
liquid manure that can be stored either under the facility
or adjacent to it. Housing and management considerations
dictate the manure-handling system.
One of the first decisions facing a livestock farmer when
considering a handling system is whether or not to provide
for manure storage. This decision must be based on a
nutrient management plan. Hauling and spreading manure
when it is removed from the animal area appears to be the
simplest and easiest handling method. In a tie-stall dairy
barn, where daily cleaning is required for sanitation, daily
removal of manure is required. If land is available, daily
spreading may be the best choice. For a bedded-pack
barn cleaned twice a year, semiannual spreading is carried
out. In outside feed yards, scraping-board poultry houses,
or hog confinement units, some other schedule would be
applied, based on a nutrient management plan.
Although immediate spreading appears to be the easiest
and most economical method, this may not be the case. A
farmer who must spread manure every day must find a
suitable location. This often results in placing manure on
fields or crops which may not immediately utilize the
nutrient value. It also may result in rutting and soil
compaction in wet fields. Spreading every day may lead
to excess wear and tear of equipment. Spreading manure
on the soil surface when crops are not growing increases
the chance for nutrient loss and can result in pollution of
nearby streams, lakes, or ground water due to leaching or
runoff. Nutrient loss usually means purchasing more
commercial fertilizer to maintain crop yields. Cover crops
can be used to retain nutrients on the farm and to provide
additional feed.
An improperly designed or sized storage system also can
be an economic and environmental hazard. A storage that
is too small may have to be cleaned out during adverse
weather, and the manure may have to be spread when field
conditions are poor, resulting in problems associated with
daily spreading. An improperly designed, constructed or
operated storage that leaks, overflows, or fails to contain
manure can cause environmental and safety hazards in the
immediate area.
A manure-handling and storage system can be an
economic liability to the farmer. All costs and benefits
must be carefully considered along with the management
advantages and efficiencies when contemplating an
investment in storage systems.

Manure Management for Environmental Protection, Document MM1
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In situations where livestock or poultry producers have
more manure than should be applied to available
cropland, an alternate utilization method is needed.
Possibilities include burning broiler litter to produce heat,
processing layer manure as a fertilizer or feed additive, or
separating and drying solids from dairy manure for
In general, alternative treatment and handling schemes are
very site specific. A farmer considering their use should
make a detailed study of the situation and take advantage
of available opportunities, such as marketing manure as a
soil conditioner, composting material or other commercial
uses. A farmer with the right motivation and proper plan
can develop economical alternative uses of manure.
Recycling manure through crops is the most common
alternative for farmers with adequate cropland to utilize
nutrients produced by animals. Manure should be applied
to land at rates that will maximize crop growth, never at
rates that will cause environmental degradation.
Because manure disposal systems are complex and may
pose both human safety and environmental hazards, they
should be designed, constructed, operated, and maintained
in a manner that protects workers and others. Fencing
around manure storages, signs to warn of possible hazards
from noxious gases, and proper machinery installation and
guarding are a few examples of special requirements.
The Pennsylvania farmer should seek assistance in
developing and coordinating a manure management
Manure Management for Environmental
and its supplements apply to most livestock
systems typical to Pennsylvania. A separate supplement
covers agricultural composting. Land application
including spray irrigation is covered by the
supplement. Treatment is covered in this
booklet and in the swine supplement. Copies of these
supplements are available from DEP regional offices. The
farmer is also encouraged to seek information from local
equipment distributors, sales personnel, consultants,
agency personnel and contractors. Specific sources of
information are:
General information:
Conservation Districts,
Certified Nutrient Management Specialists
Education and technical advice:
Extension Office
Technical planning and design assistance:
Natural Resource
Conservation Service
Financial assistance:
USDA Farm Services Agency,
Conservation Districts
Laws and regulations:
Departments of
Environmental Protection and Agriculture,
Conservation Districts
Below is a table of contents for
Manure Management for
Environmental Protection
and its supplements. The
complete collection is referred to as the Manure
Management Manual. Each section is followed by the
abbreviation used in pagination.
Manure Management for Environmental Protection
- MM
Legal and Management Aspects of Animal Manures -
Safety and Emergency Response for Manure Management
Systems - MM2
Planning, Design and Construction of Manure
Management Systems - MM3
Operation and Maintenance of Manure Management
Systems - MM4
Manure Management Strategies to Control Flies - MM5
Field Application of Manure
- Supplement FA,
a supplement to Manure Management for Environmental
Dairy Manure Manag
ement - Supplement DM,
a supplement to Manure Management for Environmental
Dairy Manure Management Alternatives
- DM1
Dairy Manure Odor Control
- DM2
Semisolid Dairy Manure Storage
- DM3
Gravity Pipes For Handling Dairy Manure
- DM4
Gravity Flow Channels For Dairy Manure
- DM5
Dairy Manure Runoff Control
- DM6
Milking Center Wastewater Management
- DM7
Sizing Dairy Manure Storage Units
- DM8
Poultry Manure Management
- Supplement PM,
a supplement to Manure Management for Environmental
Swine Manure Management
- Supplement SM
a supplement to Manure Management for Environmental
Swine Manure Management Alternatives
- SM1
Swine Manure Odor Control
- SM2

Manure Management for Environmental Protection, Document MM1
361-0300-001 / November 15, 2001 / Page 9
Treatment Basins for Swine Manure Treatment
- SM3
Swine Manure Runoff Control
- SM4
Methane Gas From Swine Manure
- SM5
Beef Manure Management
- Supplement BM a
supplement to Manure Management for Environmental
Veal Calf Manure Management
- Supplement VM
a supplement to Manure Management for Environmental
Horse, Sheep, Goat, and Small-Animal Manure
- Supplement HS a supplement to Manure
Management for Environmental Protection
Manure Management for Horses
- HS1
Managing Sheep and Goat Manure
- HS2
Managing Manure and Wastes from Small Animals
- HS3
Agricultural Composting of Manures
Copies of
Manure Management for Environmental
and its supplements are available from the
Water Quality Management office in the Department of
Environmental Protection regional offices listed below:
Southeast Regional Office
555 North Lane, Suite 1
Conshohocken, PA 19428-2233
Telephone: 24 hours (610) 832-6000
Northeast Regional Office
Two Public Square
Wilkes-Barre, PA 18711-0790
Telephone: 24 hours (570) 826-2511
Southcentral Regional Office
909 Elmerton Avenue
Harrisburg, PA 17110
Telephone: 24 hours (717) 705-4700
Northcentral Regional Office
208 West Third Street
Williamsport, PA 17701
Telephone: 24 hours (570)327-3636
Southwest Regional Office
400 Waterfront Drive
Pittsburgh, PA 15222-4745
Telephone: 24 hours (412) 442-4000
Northwest Regional Office
230 Chestnut Street
Meadville, PA 16335-3481
Telephone: 24 hours (800) 373-3398
Revised from material originally prepared by Robert E. Graves,
Extension Agricultural Engineer, The Pennsylvania State University.

Manure Management for Environmental Protection, Document MM2
361-0300-001 / November 15, 2001 / Page 1

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On-farm storage of animal manure is becoming more
common in Pennsylvania. Many dairy, beef, veal, swine,
and poultry operations are installing manure storage
systems with the potential, under certain circumstances,
for safety risks. Experience in several states indicates that
when an accident does occur, it is likely to involve two or
three fatalities. Large numbers of livestock may also
Some manure storage systems are more hazardous than
others. Below-ground storages, or pits, are more
hazardous than above-ground ones. Systems that are
covered by lids, caps, or slotted floors are more hazardous
than uncovered systems. Thus the most dangerous
storages are pits within buildings or directly beneath
livestock. Pump-out pits with lids or caps can also be
very hazardous.
Under certain circumstances, manure storage hazards
include gases that are toxic (hydrogen sulfide), asphyxiant
(carbon dioxide), corrosive (ammonia), and explosive
(methane), and may include an atmosphere that contains
insufficient oxygen to sustain life. Drowning is also a
possibility. With covered pit storages, the danger from
gases is most severe when manure is being agitated or
pumped out, and after emptying. At other times, little gas
is produced, and natural air movement or ventilation from
fans usually prevents hazardous gas buildup and oxygen
levels from becoming dangerously low. With open
storages and above-ground tanks, oxygen depletion and
toxic and explosive gas buildup are less likely, so the
major potential hazard normally associated with such
systems is drowning.
Maximum safe gas concentrations, or threshold limit
values (TLV), have been established for an 8-hour
exposure for humans by the American Conference of
Government Industrial Hygienists. TLV are expressed in
parts per million (ppm). Safe gas levels for animals have
not been established, but animal responses to gases are
known to be similar to human responses. Animals,
however, suffer more continuous exposure and may be
adversely affected over time by a lower level of gas than
affects humans. This is of particular concern with small
or lightweight animals, such as newborn pigs.
The concentrations of gases in manure storages can be
measured with special instruments, but such instruments
are reliable only if they are carefully maintained, stored,
calibrated, and operated by trained personnel. Many
instruments cost as much as a few thousand dollars.
Although using sophisticated gas detection instruments is
the best way to monitor a hazardous environment, using
the equipment may be impractical for most farmers.
However, some local emergency services may have such
instruments and can use them effectively.
An inexpensive alternative to expensive gas detection
instruments would be the use of detector tubes or direct
reading colorimetric tubes. The tubes are made
specifically for one type of gas and for one instantaneous
measurement. The cost of the tubes is around $3 to $4
each. Along with a tube, a pump and extension hose is
necessary. When correctly calibrated the pump will pull
the correct amount of air through the tube, giving an
accurate reading of the concentration of gas present. The
cost of the pump is approximately two hundred dollars.
This type of instrumentation is easy to use and requires
minimal training. One drawback is that the tube only
gives an initial reading of the gas concentration and is for
the specified gas. You would have to take readings for all
suspected gases that are present. After determining the
gas concentration(s), you should continue to monitor and
ventilate the space.

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Manure Management for Environmental Protection, Document MM2
361-0300-001 / November 15, 2001 / Page 2
Hydrogen sulfide
S), the most hazardous manure gas,
is associated with most fatalities in manure storages. H
can cause death within seconds at high concentrations.
The TLV is 10 ppm. It is colorless and heavier than air,
accumulating near the bottom of the storage. Though very
low concentrations (100 to 150 ppm) can be identified by
a rotten-egg odor, hydrogen sulfide deadens one's sense of
smell and its odor is often masked by other smells
common to livestock facilities. Lethal concentrations of
500 to 600 ppm are thus difficult to detect. The amount of
the gas can increase a thousand fold during agitation and
emptying of a manure facility.
Carbon dioxide
), while a nontoxic gas itself,
displaces oxygen and therefore can asphyxiate humans
and animals. The TLV is 5000 ppm. Being both colorless
and odorless, carbon dioxide is impossible to detect
without gas detection equipment. Because it is heavier
than air, it accumulates near the bottom of the storage.
) can severely damage the eyes, throat,
and lungs. It combines with moisture in the eyes and
respiratory tract to form an alkaline solution that causes
severe burns. Its TLV is 25 ppm. NH3 is lighter than air
and has a strong bleach-like odor. Because of its irritating
nature, people usually leave a contaminated area quickly.
Therefore it is not suspected to have caused any human
deaths. Constant low-level exposure to ammonia,
however, can have a discomforting effect on humans and
) is a highly flammable and explosive gas.
The TLV for methane is 1000 ppm. Like carbon dioxide,
it is odorless, colorless, asphyxiating, and impossible to
detect without gas detection instruments. Methane is
lighter than air and readily rises out of storage areas to
collect under hoods, roof ridges, and corners. It is most
likely to accumulate during hot weather, especially if
ventilation is poor. Methane explosions have resulted
from someone lighting a torch or from short circuits in
electrical systems.
) deficient atmosphere occurs when oxygen is
displaced by another gas to less than 19.5 % by volume of
the total air. Normally, oxygen in air is 20.8 % by
volume. When oxygen is at 16.0 % by volume of the air,
a person becomes disorientated and has impaired
judgement. At 14.0 % by volume of the air, a person has
rapid fatigue and faulty judgement. At 6.0 % by volume
of air, a person can have difficulty in breathing and death
will occur within minutes. The oxygen percent should be
measured at all levels of a manure storage to insure that
there is no oxygen deficiency.
Many safety hazards can be minimized by proper design
and construction of a manure storage facility. Several
recommendations to consider when building a storage are
listed below. Many of the recommendations should also
be incorporated into existing storages.
Keep in-barn pits for liquid manure to a minimum
volume and divide pits into small compartments to
reduce or eliminate the need for agitation.
Locate pump-out openings for manure pits outside of
buildings. Use heavy covers or grates for pit access
points and keep them in place.
Equip ventilation systems with an alarm to indicate
power failure, and provide a backup ventilation
Build railings for all walkways on piers or walls along
open manure storage structures. Push-off platforms or
piers should have a barrier strong enough to stop a
slow moving tractor. If animals are to be on a pier,
install a low guardrail to keep them from rolling into
the pit if they slip.
If the manure storage is outdoors, provide a gas trap
or other device in pipes running to the storage to
prevent gases in the storage structure from reentering
the building, especially during pit agitation.
Install a fence around open storages, ponds, treatment
basins, and lagoons. The fence should be tight enough
to keep out small children. Warning signs should be
placed near open storages and above-ground tanks,
and a rescue pole and rope should be located
conspicuously in the area.
Manure storage hazards can be further reduced by
consistently following recommended operating
procedures. You should adopt all of the following
practices that apply to your operation.
Become familiar with and follow the Occupational
Safety and Health Administration (OSHA)
regulations and recommended practices for confined
spaces (OSHA 1910.146). While production
agriculture was excluded from these regulations, any
farmer with an employee could be cited for a
violation under the General Duty Clause of the OSHA
Act, Public Law 91-596. The General Duty Clause
states that each employer “shall furnish each of his

Manure Management for Environmental Protection, Document MM2
361-0300-001 / November 15, 2001 / Page 3
employees employment and a place of employment
which are free from recognized hazards that are
causing or are likely to cause death or serious
physical harm to his employees”. A confined space,
such as a manure storage, may fit this clause.
Test the pit atmosphere for toxic gases and levels of
Never enter a pit without proper ventilation. When
going in, wear an air-supplied respirator or a self-
contained breathing apparatus (SCBA), as well as a
safety harness attached to a rope attended by two
people at the entrance to the pit. Any person utilizing
this equipment must be trained in advance. Attaching
the safety rope to a winch or hoist is also
Cartridge-type masks are not safe.
Keep people and animals out of any building where
manure is being agitated or emptied. Provide strong
mechanical ventilation during agitation and pumping,
and for a few hours after pumping has stopped. If an
animal collapses during pit agitation, do not try to
rescue it immediately. Turn off the pump and
ventilate the building until the gases have had a
chance to escape.
Never fill a manure pit completely, but allow 1 to 2
feet of air space to accommodate concentrations of
gas. Lower the level of liquid manure in a storage
facility before starting agitation to reduce the
possibility of gas being forced above floor level.
Keep the agitator below the liquid surface because gas
is released in greater volumes with vigorous surface
Forbid smoking, open flames, or spark-producing
operations in the immediate vicinity of the storage
area. Keep all guards and safety shields in place on
pumps, pump hoppers, tank wagons, and power units,
and maintain electrical motors, fixtures, and wiring in
good condition.
Do not leave temporary access ladders leaning against
above-ground tanks. Permanent ladders on the
outside of above-ground tanks should terminate above
the reach of people or should have locked entry
Do not walk, ride, or allow animals on the crust-like
surface of open-air storages. Like ice, the crust is not
uniformly solid and can break through suddenly.
Warn visitors and guests of the hazards of manure
storages. You are legally responsible for their safety
while they are on your property.
Emergencies result from ignoring or not knowing the
hazards of manure storages and the recommended safety
practices. Generally, someone enters a pit without a
self-contained breathing apparatus (or is not properly
trained in its use) and passes out almost immediately from
toxic gases or oxygen deficiency. The tragedy can be
compounded when would-be rescuers, family, coworkers,
emergency personnel—panic and follow the first victim
into the pit.
When someone collapses in a pit, gases are so
concentrated that it is extremely dangerous for anyone
else to enter without a self-contained breathing apparatus
and proper training. The only reasonable immediate
action is to ventilate the storage area and notify rescue
personnel who can bring the proper equipment. Barn fans
and silo blowers may be activated to provide ventilation,
but do not lower fans into the pit because of the
possibility of a methane explosion.
In any rescue attempt, the rescuer should have a self-
contained breathing apparatus, proper training and a
safety harness with a lifeline. The lifeline should be
attended by at least two people outside the storage unit.
Rescuers should never place their own masks on a victim
or remove their own lifelines. Ropes, carriers, and
oxygen for victims can be lowered into the pit if
necessary. Victims should be brought out as quickly as

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Manure Management for Environmental Protection, Document MM2
361-0300-001 / November 15, 2001 / Page 4
possible, administered to by emergency services
personnel, and transported to an emergency room.
Prepared by Dennis J Murphy, Extension Safety Specialist, and William
Lloyd, Graduate Assistant, The Pennsylvania State University.

Manure Management for Environmental Protection, Document MM3
361-0300-001 / November 15, 2001 / Page 1

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Livestock and poultry farms need manure management
systems, usually including manure storage facilities, to
properly handle their manure. A manure management
system must be linked to a nutrient management plan that
determines how long manure must be stored or that
verifies that the available storage capacity is adequate for
the longest period between scheduled field applications.
Depending on the type of farm operation and the nutrient
management plan, the manure management system may
need other components in addition to a storage facility.
These might include barnyard runoff control, roof runoff
management, and field erosion and runoff control
practices. The mix of components that will be suitable
must be determined on a case-by-case basis by qualified
professional conservationists who work with the farmer.
At the planning stage, the farmer must consult with
appropriate specialists, such as a nutrient management
specialist, a soil scientist, and an engineer. A complete
plan is needed prior to design preparation to assure that
the farmer’s needs and legal obligations can be met. The
plan must identify the type, number or size, and
location(s) of all the components of the manure
management system. To the fullest extent possible, the
components must be identified as named conservation
practices from the PA Technical Guide. A list of the
practices is included in Section IV of the PA Technical
Careful design, materials selection, and construction are
required to build a sturdy, safe and environmentally sound
manure management system. Designs of all practices
must be done in accordance with the PA Technical Guide
standards and this manual, and must prevent or eliminate
the discharge of manure or contaminated water under all
weather conditions up to the 25-year, 24-hour storm. A
farm operation with facilities built to a lesser standard
may be required to obtain a NPDES permit. A manure
storage facility built to a lesser standard may be required
to obtain a Water Quality Part II permit.
For manure storage facilities where the manure is of semi-
solid or liquid consistency, there is a potential hazard to
public health and safety. Because of this potential hazard,
these types of manure storage facilities must be designed,
construction overseen and completion certified by a
Pennsylvania registered Professional Engineer. In many
cases, storage components are “pre-engineered” or based
on standard detail drawings. Even though these
components may have been prepared or approved by an
engineer, their appropriate use must be based on a site
investigation and a site-specific design, prepared or
approved by a Professional Engineer, which includes the
“pre-engineered” component.
All manure storage ponds shall be designed in accordance
with Standard PA-313. A key element in the design of
manure storage ponds is the provision for watertight
containment of the waste. The ponds shall be lined with a
compacted clay soil, a soil with clay or chemical
additives, a geosynthetic liner, a concrete liner, or a
combination of these features. Soil liners shall be
designed and built in accordance with Appendix 10D of
the Agricultural Waste Management Field Handbook.
All manure storage structures shall be designed in
accordance with Standard PA-313. Manure storage
structures for semi-solid or liquid manure shall be
watertight. They shall be designed and built of concrete,
steel, durable plastic, or a combination of these materials.
All manure storage facilities shall be designed and built to
prevent leaching or runoff of contaminated water into
surface or ground water.
All manure transfer systems shall be designed and built to
be watertight under all normal operating conditions and in
accordance with standard PA-634, “Manure Transfer”.
Pipes shall be adequate to handle all internal and external
design loads, and be equipped with watertight joints that
exceed the expected operating pressure.
The designer of any component of a manure management
system must provide the farmer with a copy of the design,
including any as-built design changes, and a written
operation and maintenance plan that explains the proper
operation and care of all the components of the designed
facility. All designs must include specifications that
describe the quality of the materials and the method or
performance requirements that the farmer or contractor
must meet to properly install the designed practice. The
specifications must be tailored to the specific design, and
shall be in conformance with the PA Technical Guide
specifications for the particular practice.

Manure Management for Environmental Protection, Document MM3
361-0300-001 / November 15, 2001 / Page 2
The farmer is responsible for having the component
practices installed according to the design and for
requiring the contractor(s) to provide quality control
during construction and to certify that they have followed
the design and specifications. Independent quality
assurance, including inspections by qualified individuals,
will protect the investment of the farmer and minimize
liability. All field design changes must be approved by
the designer and recorded on as-built drawings.
A manure storage facility is defined as a permanent
structure or facility, or portion of a structure or facility,
utilized for the primary purpose of containing manure.
Examples include liquid manure structures, manure
storage ponds, component reception pits and transfer
pipes, containment structures built under confinement
buildings, permanent stacking and composting facilities
and manure treatment facilities. The term does not
include the animal confinement areas or poultry houses,
horse stalls, freestall barns or bedded pack animal housing
Prepared by Timothy J. Murphy, Conservation Engineer, USDA Natural
Resources Conservation Service

Manure Management for Environmental Protection, Document MM4
361-0300-001 / November 15, 2001 / Page 1

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The goals of manure management are to efficiently utilize
manure nutrients, to protect the public's health and safety,
to minimize degradation of the air and soil, and to prevent
pollution of surface water and ground water. A well-
designed manure management system provides for storage
of manure and its utilization on cropland or for other
purposes. Some systems also use manure treatment
lagoons (not to be confused with storage ponds) which use
microbial action to break down wastes to reduce the
nutrient content of wastewater.
This document provides guidelines for effective operation
and maintenance of manure management systems.
Procedures necessary for both storage and treatment
systems are listed, followed by measures specific to
treatment systems. Important safety considerations are
listed for both storage and treatment.
Operating and maintaining a manure management system
is the owner/operator's responsibility. He or she should
use a site-specific plan to manage the manure and other
wastes in an environmentally acceptable manner. Such a
plan should also provide specific details concerning the
system's various components, including the following
Minimum and maximum operating depths for storage
and treatment facilities.
Operations specific to a given system, such as manure
nutrient analysis, salinity and pH checks, methods of
loading, or the approximate frequency of solids
Safety warnings, particularly where there is danger of
drowning or exposure to poisonous or explosive
Operating instructions and maintenance requirements
for pumps, valves and other mechanical equipment.
Operating instructions for all BMPs, including
frequency of barnyard scraping, cleaning of settling
and screening devices and vegetative filter area
dosing intervals.
The following list of procedures for operation and
maintenance applies to both manure storage and manure
treatment systems.
Design your manure facility to fit the nutrient
management plan.
Develop and implement a nutrient management plan
that meets the requirements in the manure manual.
In storage ponds and treatment lagoons, install and
maintain a gauge post that clearly marks the one-half-
full and full operating volumes.
At least twice a year, when a storage facility is
unloaded, check the walls and floor for cracks or
separations. Check the backfill areas around
structures for excessive settling, and determine the
cause. Make the necessary repairs.
On earthen facilities, check the berms and
embankments twice a year for sloughing, erosion, or
settling. Make repairs to maintain the impervious
lining, the slope stability and the top height and
The outlets of foundation drains and subdrains should
be kept open and checked frequently, and must drain
to a satisfactory outlet. Repairs should be made to
correct any leaking of manure into the drains. To
check for leaks, the drain's outflow should be
observed when the facility is being used. Leaking
may be detected by the color and smell of the
outflowing liquid; by lush, dark green vegetation
around the outlet; by the algae growth in the surface
outlet; or by the vegetation dying near the outflowing
To prevent erosion, good vegetative cover should be
established and maintained on berms and
embankments. Plantings should be clipped three
times each year to encourage their growth and to kill
weeds. If the vegetative cover is damaged, berms and
embankments should be replanted as soon as
Channels and berms of clean-water diversions around
the barnyards, buildings, and manure facilities should
be inspected frequently. The channels should be
protected from erosion. Berms must be high enough
for the channels to have adequate capacity. The
channels and berms should be mowed periodically

Manure Management for Environmental Protection, Document MM4
361-0300-001 / November 15, 2001 / Page 2
and should not be used as haul roads unless they were
designed and constructed for that purpose.
Buildings, structures, berms, and embankments
should be checked frequently for burrowing animals.
The animals should be removed and any damage
Haul roads and other approaches to manure facilities
should be inspected frequently and the need for stone,
gravel, or other stabilizing material determined.
Runoff or spills from loading areas should not be
allowed to flow into streams or roadside ditches.
Fences should be inspected and maintained to keep
livestock and unauthorized people away from manure
facilities. All warning and hazard signs should be
examined and repaired when necessary.
Several additional guidelines apply to the safe and
effective operation of manure treatment lagoon. Unless
otherwise stated, these apply to both aerobic and
anaerobic lagoons.
Before using an anaerobic lagoon, fill it to half its
designed volume (4 to 5 feet deep for most lagoons).
If possible, begin loading a lagoon in the spring or
Add manure to a lagoon regularly, frequently, and in
increasing amounts until each day's production is
added daily.
Maintain an anaerobic lagoon at or near the designed
depth (6 to 9 feet for most lagoons).
Except for naturally aerated lagoons, never empty a
lagoon below the 5-foot to 6-foot level. If salt builds
up in a lagoon, restart the lagoon from the 5-foot
depth. To control odor, maintain the lagoon's pH
above 6.7. Hydrated lime can be added daily at the
rate of 1 pound per 1000 square feet until the pH
becomes neutral (7.0).
Check the sludge buildup in a lagoon annually. When
sludge fills the designed storage volume, test its
nutrient content and spread it on cropland
Manure storage and treatment facilities, especially
covered tanks or pits, are high hazard areas. The
biodegradation of manure forms gases, such as methane
), hydrogen sulfide (H
S), ammonia (NH
), and
carbon dioxide (CO
), which can be fatal to both animals
and humans. In the proper mixture with air, some of the
gases can also explode. For these and other reasons,
manure facilities require strict safety precautions,
including the following:
When someone is working near a manure facility, the
area should be well ventilated. Welding near storage
or using open flames or electric motors that spark
(e.g., saws, drills, shop-vacs) is extremely hazardous
and should be avoided.
Care must be taken to provide mechanical ventilation
during agitation and emptying of indoor manure
facilities because agitated liquid manure can release
large volumes of dangerous gases. Humans should
always stay out of the building during agitation and
emptying. If the adequacy of ventilation is uncertain,
animals should be evacuated. No one should work
alone when agitating or emptying a manure facility.
A tank, pit, or other closed storage structure that has
been emptied of manure still contains dangerous
gases. No one should enter the structure except to
make repairs, and then only with special precautions,
including a safety harness, mechanical ventilation of
the structure, and an air-supplied respirator or self-
contained breathing apparatus (NOT A
CARTRIDGE-TYPE MASK) including proper
training. Two people should remain outside to take
appropriate action in the event of an emergency.
All lids, gates, hatch covers, and safety grills to
prevent unauthorized entry must be secured when
tanks and pits are left unattended. Heavy slide-in-
place covers can be moved by livestock.
Manure storage and treatment facilities should be
posted with signs bearing appropriate warnings. (See
example on Page 1, MM2)
Open, ground-level facilities, such as storage
facilities, should have an additional warning. (See
example on Page 3, MM2)
Prepared by William J. Bower, State Conservation Engineer and
Timothy J. Murphy, Conservation Engineer., USDA Natural Resources
Conservation Service.

Manure Management for Environmental Protection, Document MM5
361-0300-001 / November 15, 2001 / Page 1

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Numerous species of manure-breeding flies can become a
serious problem on the farm and within the community if
manure-handling systems are not managed properly. With
the movement of people and housing into prime
agricultural areas, flies dispersing from livestock and
poultry operations can become a significant public
nuisance and health problem, even leading to poor
community relations and threats of litigation.
Flies have four stages of development: egg, larva
(maggot), pupa, and adult. The rate of development,
which varies with species and environmental conditions, is
affected by temperature and moisture levels within the
breeding area. Moist manure attracts adult flies and
provides ideal breeding conditions.
Figure 1. House fly life cycle.
Species most prevalent around livestock housing are the
house fly (Musca domestica), stable fly (Stomoxys
calcitrans), little house fly (Fannia canicularis), black
garbage fly (Hydrotaea aenescens), and drone fly
(Eristalis tenax).
House flies
usually are the predominant species present in
livestock and poultry operations. House flies are nonbiting
flies that breed in fresh manure, decaying silage, spilled
feed, bedding, and other decaying organic matter. Adults
feed on manure and animal secretions with their sponging
mouth parts. Under ideal conditions, they can complete
their life cycle in as little as 7 days. On the farm, most
generations of flies require about 2 weeks to develop in
summer. Each female can produce 120 to 150 eggs,
which are laid in at least six batches at 3- to 4-day
intervals. Eggs hatch in 8 to 24 hours and maggots feed
for 4 to 7 days. Mature maggots usually crawl away from
their breeding site, seeking a drier environment for
pupation. Adult flies emerge in 3 to 4 days and typically
live about 3 to 4 weeks.
Moisture levels of 75 to 80 percent are optimal for house
fly oviposition (egg laying), larval development, growth,
longevity, and survival. Fresh cattle manure is
approximately 83 percent moisture and fresh poultry
manure is 75 percent moisture. Larvae developing in
organic substrates with less than 60 percent moisture
usually fail to pupate. Optimal moisture levels for
pupation range from 40 to 60 percent.
House fly populations in Pennsylvania increase rapidly in
June, peak in September, and decline with cold weather in
early October. From seven to nine generations occur
during the fly season. Within environmentally controlled
livestock housing (i.e., high-rise or deep-pit poultry
houses), suitable breeding conditions may be present year
round. Broken eggs, failure to control leaky waterers, and
an occasional dead bird in the manure storage add to the
High-rise houses normally are cleaned only once or twice
a year. House flies often disperse in large numbers as far
as 3.7 miles from their breeding site; and distances of 10
to 20 miles have been reported. While house flies are
only a minor direct annoyance to livestock, their potential
for transmission of diseases and causing a public nuisance
are of major concern.

Manure Management for Environmental Protection, Document MM5
361-0300-001/ November 15, 2001 / Page 2
Figure 2. House fly.
Stable flies
are vicious biters commonly associated with
dairy and equine operations. Male and female stable flies
feed several times each day, ingesting one or two drops of
blood at each meal. When not feeding, adult flies rest in
the shade on posts, trees, and buildings. Breeding takes
place in wet straw, spilled feeds, silage, and decaying
vegetation. The stable fly's life cycle is longer than that of
the house fly, requiring about 3 weeks to complete under
optimal conditions. Eggs hatch in 1 to 3 days, and the
maggots feed for 11 to 30 days before reaching maturity,
depending on the weather. When fully grown, they pupate
and within 6 to 20 days, emerge as adults which live for
20 to 30 days. Each female lays 200 to 400 eggs during
her lifetime. Stable flies have two primary generations per
season, peaking in early July and again in early
September. They over-winter as larvae or pupae. Stable
flies can travel many miles from the breeding site.
Little house flies
usually are most abundant in early spring
and late fall, when fly control practices normally are
considered unnecessary. Eggs are deposited chiefly on
decaying vegetable matter and chicken, hog, horse, and
cattle manure. Life cycles may vary from 3 weeks to 2
months, depending on environmental conditions. The
larvae are flattened, about 6 mm long when fully grown,
and conspicuously fringed with spine like projections.
The pupae resemble the larvae in appearance. Adult flies
prefer a sheltered habitat, inside or on the shaded sides of
Figure 3. Stable fly.
Figure 4. Little house fly.
Black garbage flies
often are found in large numbers in
poultry houses. Their life cycle is 14 to 17 days. The
larvae develop readily in poultry manure and may prey on
house fly maggots. The black fly larvae are not
considered to be practical biological control agents for
house flies, since the black fly adults are also pests.

Manure Management for Environmental Protection, Document MM5
361-0300-001/ November 15, 2001 / Page 3
Figure 5. Black garbage fly.
Drone or flower flies
(rat-tailed maggots) are common
inhabitors of liquid manure tanks, storage basins, and
anaerobic treatment basins. Where livestock are housed
on slatted floors over liquid manure tanks, rat-tailed
maggots may be found breeding in large numbers during
the summer. There are usually several broods a year. The
maggots are an inch long and have a long tail. When fully
developed, they move from liquid waste to drier areas to
pupate and change into adult flies. During this period, the
maggots become nuisance pests, crawling by the
thousands onto walkways, feed bunks, and elsewhere.
Piles of sawdust, sand, and other dry material near the
manure pits provide a pupation site and reduce the number
of crawling maggots within the barn and milkhouse.
Other than being a nuisance, this insect causes no harm.
Figure 6. Drone or flower fly (rat-tailed maggot).
Sanitation, moisture control, and manure management are
critical to a successful fly-control program, which must
break the fly reproduction cycle. The number of suitable
fly breeding sites must be kept to a minimum and
conditions favorable to the development of natural fly
predator populations must be maintained. Appropriate
insecticides may be used when necessary, but chemical
control works best in conjunction with good sanitation
practices. It is easier and less expensive to prevent a
heavy fly buildup than to control large fly populations
after buildup has occurred. If pesticides are applied
directly to manure or fed through animals for fly control,
label restrictions must be followed.
Fly control requires more than just manure removal
because hauling of animal manures and organic debris
controls only the immature insects. Spreading the manure
thinly in the fields kills eggs and larvae through drying.
Failure to spread the manure evenly leaves large clumps
where adult flies can develop and even produce a second
field generation in wet weather.
Incorporation of manure
into the soil soon after it is spread aids in breaking the fly
development cycle
While manure and organic debris removal controls
maggots and pupae, adult fly populations within the barns
and poultry houses must also be killed. This can be
accomplished through the use of residual insecticide
sprays, space sprays, and baiting. All pesticide label
instructions and safety measures should be followed.
Failure to control adult flies prior to manure removal may
release many flies into the community.
In dairy cattle operations, three potential fly breeding
spots are calf pens or hutches and box stalls used for
freshening and for sick animals, and spilled or wasted
feed. Pens should be cleaned as frequently as possible
and outdoor calf hutches moved regularly. Wet hay or
straw, other organic matter, and silage seepage should be
removed. Barnyards should have proper drainage, with
gravel and other fill used to eliminate low spots.
Alteration of breeding sites to moisture levels below 60
percent should significantly reduce fly populations. Since
both stable and houseflies breed in wet grain, silage,
haylage, and fermenting green-chopped materials, areas
around and under feed bunks can also be fly breeding sites
when water drains from the bunks and mixes with manure
and spilled feed. Adult flies observed on or around
manure may have come from other breeding sites, such as
wet silage or spilled feed. Improved silage and feed
management can control what may be perceived as a
manure related problem.

Manure Management for Environmental Protection, Document MM5
361-0300-001/ November 15, 2001 / Page 4
Manure storage systems that are not completely liquid can
also be a major source of flies, especially during dry
weather. As maggots leave the manure to pupate, they
seek dry areas. Liquid material completely surrounding
solid or semisolid material prevents successful pupation.
During dry weather, water may need to be added to a
liquid tank or basin to maintain the solid-liquid interface
along the storage edges. Also, manure containing large
amounts of straw, hay, and sawdust may furnish adequate
pupation sites. Seepage from the manure storage areas can
also furnish suitable fly breeding sites outside of the
storage area. If moisture levels remain above 85 percent,
liquid manure systems will not be a breeding site for flies
other than rat-tailed maggots.
Within shallow or deep-pit poultry houses, moisture levels
are affected by several different factors. Leaks in the
poultry watering system are the major source of excess
moisture in the manure. Producers should check for leaks
on a regular basis. Some manure pits also remain wet due
to seepage from the exterior, which can be avoided by
proper site selection, grading, and drainage. Houses
equipped with scrapper boards usually have lower
moisture levels since the scrapper boards aid in manure
drying. A few poultry producers use a series of fans or
mechanical rakes to dry the manure further. Keeping the
pit dry, so that the manure cones up under the cages,
reduces the amount of manure suitable for fly breeding
and enhances populations of naturally occurring predators
and parasites.
Accumulations of manure which have the proper moisture
and physical conditions often contain large numbers of
mites, parasitic wasps, and beetles, which prey on fly eggs
or larvae. In an attempt to enhance natural predator/prey
populations, stored semisolid or stacked manure should be
maintained in as dry a condition as possible. This provides
a desirable habitat for the predator and parasite
reproduction and reduces the suitability of the manure for
fly oviposition and larval development.
Populations of predators and parasites are affected by the
manure removal schedule. In livestock housing designed
for manure removal every few days, there is no buildup of
the beneficial agents. In situations where manure is stored
over long periods of time and natural predators and
parasite populations have built up, only part of the manure
should be removed at a time. A thick base of old manure
should be left to perpetuate the beneficial insects as well
as to assist in absorbing excess moisture as new manure is
Prepared by Clarence H. Collison, Extension Entomologist, the
Pennsylvania State University.

Manure Management for Environmental Protection
361-0300-001 / November 15, 2001
American Lung Association of Iowa
1321 Walnut Street, Des Moines, IA 50309
Agriculture Respiratory Hazards Education Series:
Unit 4
Livestock Confinement Dust and Gases
Unit 8
Measurement of Agricultural Dust and Gases
Unit 9
Personal Protection Equipment
American Society of Agricultural Engineers
2950 Niles Road, St. Joseph, MI 49085
Control of Manure Odors
Manure Production and Characteristics
Design of Manure Storages
Midwest Plan Service, Ames, IA
Available from Agricultural Publication Center
112 Agricultural Administration Building
University Park, PA 16802
Livestock Facilities Handbook
Research Results in Manure Digestion Runoff,
Refeeding, Odors
MWPS-36 Concrete Manure Storage Handbook ($20.00)
Minnesota Cooperative Extension
Agricultural Engineering Building
University of Minnesota, St. Paul, MN 55108
Farm Training Notebook: Dangers in the Air When
Handling Livestock
National Safety Council
444 North Michigan Avenue, Chicago, IL 60611
Industrial safety data sheets:
482 -
Excavation, General
254 -
Excavation, Trench
Northeast Regional Agricultural Engineering Service
250 Agricultural Engineering Building
University Park, PA 16802
Pole Frame Buildings
Penn State Cooperative Extension
Agricultural Publication Center,
112 Agricultural Administration Building
University Park, PA 16802
Controlling Insects and Mites on Dairy and Beef
Controlling External Parasites on Poultry
Poultry Management for Pennsylvania and the
Penn State Department of Agricultural & Biological
246 Agricultural Engineering Building
University Park, PA 16802
Fact Sheets:
Personal Protective Devices
Agricultural Respiratory Hazards and
Protective Devices
Farm Respiratory Hazards
Manure Storage Hazards
Where to Have Your Water Tested
Manure Storage and Settling Basin
Water Weighted Valve Opener
G-79 Odor Control for Animal Production Operations
Portland Cement Association
5420 Old Orchard Road
Skokie, IL 60077
Circular Concrete Tanks Without Prestressing
Natural Resources Conservation Service
Available for inspection at county NRCS offices;
distributed by National Technical Information Service,
U.S. Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
(703) 605-6000
email: orders@ntis.fedworld.gov.
EFM-1, 1A-1I-
Engineering Field Manual for
Conservation Practices
AWMFH-1, 1A-1C,
Agricultural Waste Management
Field Handbook
PA Technical Guide Section IV-Standards and
Specifications for Pennsylvania

This and related environmental information are available electronically via Internet. For more
information, visit us through the PA PowerPort at http://www.state.pa.us or visit DEP directly at
http://www.dep.state.pa.us (choose directLINK “Manure Management”).
www.GreenWorks.tv - A web space dedicated to helping you learn how to protect
and improve the environment.
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Environmental Fund for Pennsylvania, with financial support from the Pennsylvania
Department of Environmental Protection, 877-PA-GREEN.

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