Archived Publication 

This information provided in this document is for reference. Please be aware that 

the information in this document may be outdated or superseded by additional 

information. 

EPA promulgated regulations for Concentrated Animal Feeding Operations 

(CAFOs) in February 12, 2003 that expanded the number of operations covered 

by the CAFO regulations and included requirements to address the land 

application of manure from CAFOs. The rule became effective on April 14, 2003. 

NPDES-authorized states were required to modify their programs by February 

2005 and develop state technical standards for nutrient management. On 

February 28, 2005, in response to litigation brought by various organizations, the 

Second Circuit court issued its decision in Waterkeeper Alliance et al. v. EPA, 

399 F.3d 486 (2d Cir. 2005). EPA has updated the CAFO rule to reflect the 

changes requested by the Court. Visit www.epa.gov/npdes/caforule to view the 

2008 CAFO Final Rule and supporting documents. 
Managing Manure Nutrients at 

Concentrated Animal Feeding 

Operations 

December 2004
U.S. Environmental Protection Agency

Office of Water (4303T) 

1200 Pennsylvania Avenue, NW 

Washington, DC 20460 

EPA-821-B-04-009
Disclaimer 

This is a guidance manual and is not a regulation. It does not change or substitute for any legal 

requirements. While EPA has made every effort to ensure the accuracy of the discussion in this 

guidance, the obligations of the regulated community are determined by the relevant statutes, 

regulations, or other legally binding requirements. This guidance manual is not a rule, is not 

legally enforceable, and does not confer legal rights or impose legal obligations upon any 

member of the public, EPA, States, or any other agency. In the event of a conflict between the 

discussion in this document and any statute or regulation, this document would not be 

controlling. The word —should“ as used in this guidance manual does not connote a 

requirement, but does indicate EPA‘s strongly preferred approach to assure effective 

implementation of legal requirements. This guidance may not apply in a particular situation 

based upon the circumstances, and EPA, States and Tribes retain the discretion to adopt 

approaches on a case-by-case basis that differ from this guidance manual where appropriate. 

Permitting authorities will make each permitting decision on a case-by-case basis and will be 

guided by the applicable requirements of the CWA and implementing regulations, taking into 

account comments and information presented at that time by interested persons regarding the 

appropriateness of applying these recommendations to the particular situation. In addition, EPA 

may decide to revise this guidance manual without public notice to reflect changes in EPA‘s 

approach to implementing the regulations or to clarify and update text. 
Managing Manure at Concentrated Animal Feeding Operations

Version Control

Version EPA Publication

Number

Publication

Date

Description of Changes Author’s

Initial

1 EPA-821-B-04-006 August 2004 Initial Release PHS

2 EPA-821-B-04-009 December 2004 Revised Appendix H; Updated

Phosphorus Index

PHS
TABLE OF CONTENTS

Page 

CHAPTER 1: INTRODUCTION .............................................. 1-1

A. Purpose of this Document ........................................ 1-1

B. Scope of this Document ......................................... 1-1

C. How To Use this Document ...................................... 1-1

D. Other Related Documents ....................................... 1-2

E. Scope of CAFO Regulations ...................................... 1-3

F. CAFOs with No Potential to Discharge .............................. 1-4

G. Comments on Managing Manure .................................. 1-5

CHAPTER 2: OPERATION, MAINTENANCE, AND RECORDKEEPING

REQUIREMENTS FOR THE PRODUCTION AREA ................... 2-1

A. Design Standards .............................................. 2-4

1. Adequate Storage for Manure, Litter, and Process Wastewater ..... 2-5

2. No Discharge for Production Areas ........................... 2-8

B. Proper Operation and Maintenance ............................... 2-10

1. Liquid Storage Structures ................................. 2-11

2. Solid Storage Structures .................................. 2-19

3. Visual Inspections ....................................... 2-19

C. Mortalities, Direct Contact, and Chemical Disposal .................. 2-21

1. Management of Animal Mortalities .......................... 2-21

2. Direct Contact of Animals With Surface Water ................. 2-23

3. Disposal of Chemicals .................................... 2-23

D. Records ..................................................... 2-24

E. Additional Voluntary Controls .................................... 2-25

1. Groundwater Protection Controls ........................... 2-25

2. Lagoon Covers ......................................... 2-26

3. Additional References .................................... 2-27

CHAPTER 3: PREPARING FOR LAND APPLICATION OF MANURE, LITTER,

OR WASTEWATER ............................................ 3-1

A. Manure Sampling .............................................. 3-1

B. Records ...................................................... 3-3

C. Additional Voluntary Controls ..................................... 3-3

CHAPTER 4: OPERATION, MAINTENANCE, AND RECORDKEEPING

REQUIREMENTS FOR THE LAND APPLICATION AREA .............. 4-1

A. Testing Protocols for Manure, Litter, and Soil ........................ 4-1

1. Collecting Manure for Land Application ....................... 4-2

2. Manure Sampling and Testing .............................. 4-3

3. Soil Sampling and Testing ................................. 4-3

B. Protocols to Land Apply Manure ................................... 4-5

1. Nutrient Management Plan ................................. 4-6

2. Required Nutrient Management Plan Format ................... 4-7

3. Plan Certification ......................................... 4-7

4. Comprehensive Nutrient Management Plans ................... 4-7

5. Crop Rotations and Crop Nutrient Requirements ................ 4-8

6. Application Rate ......................................... 4-8

7. Application Method ...................................... 4-12

i 
TABLE OF CONTENTS 

Page 

8. Application Timing ....................................... 4-15

9. Equipment Calibration and Inspection ....................... 4-17

10. Additional Land Application Considerations ................... 4-18

11. NMP Review and Revision ................................ 4-18

C. Records ..................................................... 4-19

D. Site-Specific Conservation Practices .............................. 4-19

1. Required Setback or Buffer ................................ 4-20

2. Alternatives to Setbacks .................................. 4-20

E. Voluntary Conservation and Pollution Prevention Practices ............. 4-22

1. Feeding Strategies ...................................... 4-23

2. Water Conservation ..................................... 4-23

CHAPTER 5: VOLUNTARY PERFORMANCE STANDARDS FOR CAFOS ............ 5-1

A. Overview of the Baseline Requirements ............................. 5-1

B. Overview of the Voluntary Performance Standards Program ............. 5-2

1. Program Participation ..................................... 5-2

2. Pollutants of Concern ..................................... 5-2

3. Required Technical Analysis ................................ 5-3

4. Validation of Equivalent Pollutant Reductions ................... 5-3

5. Relationship to Existing NPDES Permits ...................... 5-4

C. Step-By-Step Requirements for Participation in the Voluntary Performance

Standards Program ............................................. 5-4

1. Determining Baseline Pollutant Discharge ..................... 5-4

2. Demonstrating That an Alternative Control Technology Achieves

Equivalent or Better Pollutant Reductions ...................... 5-6

3. Obtaining an Alternative Performance Standard ................. 5-7

4. Future Case Studies ..................................... 5-21

CHAPTER 6: DEVELOPING AND USING TECHNICAL STANDARDS FOR THE

LAND APPLICATION OF MANURE, LITTER, AND PROCESS

WASTEWATER ............................................... 6-1

A. Developing Technical Standards for Land Application .................. 6-1

1. EPA Recommended Technical Standards and Policies ........... 6-1

2. Factors for Developing Technical Standards ................... 6-4

3. NRCS Standards and NMPs ................................ 6-4

4. Example National Nutrient Management Technical Standards for

Land Application ......................................... 6-5

5. Appropriate Flexibility in Applying Technical Standards ........... 6-5

B. Example Rate Calculations ....................................... 6-6

1. Manure Production and Composition ......................... 6-6

2. Developing a Nutrient Budget ............................... 6-8

3. Land Application Rate Calculation .......................... 6-11

C. Manure Management Planner ................................... 6-12

CHAPTER 7: AVOIDING COMMON DEFICIENCIES .............................. 7-1

A. Proactive Management ......................................... 7-1

B. Common Deficiencies ........................................... 7-2

1. Inadequacy of Storage Capacity ............................. 7-2

ii
TABLE OF CONTENTS

CHAPTER 8: 

A. 

B. 

C. 

D. 

E. 

Appendix A -

Appendix B -

Appendix C -

Appendix D -

Appendix E -

Appendix F -

Appendix G -

Appendix H -

Appendix I -

Appendix J -

Appendix K -

Appendix L -

Appendix M -

Page 

2. Infrequent Dewatering of Storage Structures . . . . . . . . . . . . . . . . . . . 7-2

3. Pumpdown Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

4. Lagoon Agitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

5. Representative Manure Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

6. Animal Mortality Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7. Chemical Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

8. Emergency Action Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

9. Example Onsite Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 

ADDITIONAL RESOURCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 

USDA Funding Programs for CAFOs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 

USDA and EPA Livestock and Poultry Environmental Stewardship 

Curriculum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2 

EPA Programs and Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2 

USDA Programs and Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4 

Associations and Trade Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5 

EFFLUENT LIMITATIONS GUIDELINES AND STANDARDS FOR 

CONCENTRATED ANIMAL FEEDING OPERATIONS 

INSPECTION CHECKLIST FOR A LARGE CAFO 

RECORDKEEPING CHECKLIST FOR THE PRODUCTION AREA AND LAND 

APPLICATION AREA AT A LARGE CAFO 

MEASURING THE AMOUNT OF ANIMAL WASTE 

ANIMAL WASTE SAMPLING 

SOIL SAMPLING AND TESTING 

LEACHING INDEX 

PHOSPHORUS INDEX 

AGRONOMIC NUTRIENT APPLICATION RATE 

CALIBRATING ANIMAL WASTE SPREADERS AND IRRIGATORS 

SOIL LOSS (EROSION) 

WINTER SPREADING TECHNICAL GUIDANCE 

MINIMUM DEPTH OF RAIN AT WHICH RUNOFF BEGINS 

Appendix N - RECOMMENDED BEST MANAGEMENT PRACTICES (BMPS) AND 

CONSERVATION PRACTICE STANDARDS 

iii
TABLE OF CONTENTS

Page 

Appendix O - EXAMPLE NATIONAL NUTRIENT MANAGEMENT TECHNICAL STANDARD 

Appendix P - CALCULATIONS FOR ESTIMATING MEDIAN ANNUAL OVERFLOW 

VOLUMES AND ANNUAL AVERAGE DISCHARGE OF POLLUTANTS 

iv
LIST OF TABLES

5-1 Summary Description of Baseline Requirements ............................ 5-2

LIST OF FIGURES

1-1 Example CAFO Potentially Demonstrating No Potential to Discharge ............ 1-5

2-1 Production Area at Whole Milk Dairy ..................................... 2-3

2-2 Cross Section of Properly Designed Lagoon .............................. 2-14

2-3 Schematic of Lagoon Depth Marker ..................................... 2-17

v
CHAPTER 1: INTRODUCTION ............................................... 1-1

A. Purpose of this Document ........................................ 1-1

B. Scope of this Document ......................................... 1-1

C. How To Use this Document ...................................... 1-1

D. Other Related Documents ....................................... 1-2

E. Scope of CAFO Regulations ...................................... 1-3

F. CAFOs with No Potential to Discharge .............................. 1-4

G. Comments on Managing Manure .................................. 1-5

Figures 

1-1 Example CAFO Potentially Demonstrating No Potential to Discharge ............ 1-5
Chapter 1: Introduction 

CHAPTER 1: INTRODUCTION 

A. Purpose of this Document 

In early 2003, EPA issued significant revisions to its regulations for NPDES permitting of

concentrated animal feeding operations (“CAFOs”) under the Clean Water Act. In December, 

2003, EPA issued a guidance document for CAFO permitting titled “NPDES Permit Writers’

Guidance Manual and Example NPDES Permit for Concentrated Animal Feeding Operations,” 

EPA-833-B-04-001 (“Permit Guidance”). That guidance document discussed the general

framework for NPDES permitting of CAFOs under the Clean Water Act and EPA’s revised

regulations. It addressed such issues as when does an animal feeding operation become

defined as a CAFO, when are CAFOs required to get a permit, the difference between general

permits and individual permits, and what effluent limitations and standards should or must be

included in NPDES permits for CAFOs. 

This document, “Managing Manure,” is designed to supplement EPA’s previous

guidance by providing additional technical information to owners, operators, technical service

providers, consultants, and permit authorities on how to carry out EPA’s revised regulatory

requirements for NPDES permitting of CAFOs. It also provides information on voluntary

technologies and management practices that may both improve the production efficiency of

CAFOs and further protect the quality of the nation’s waters. This document assumes that 

readers have a basic understanding of the CAFO regulations. 

B. Scope of this Document 

EPA’s regulations governing CAFOs consist primarily of two different sets of regulations. 

First, the regulations at 40 CFR 122.23 set the framework for CAFO permitting by establishing

criteria for who is defined as a CAFO and specifying whether, and when, a CAFO must apply for

a permit. The second set of regulations, which are at 40 CFR Part 412, are the effluent

limitations guidelines and standards (“ELGs” or “effluent guidelines”) for CAFOs, which establish

discharge limits and certain management practice requirements that must be included in

NPDES permits for CAFOs. 

While the regulations at 40 CFR 122.23 apply to all operations, it should be noted that

the ELG requirements in 40 CFR Part 412 apply only to permitting of Large CAFOs, as that term

is defined in the regulations. The statements below on what is required under the ELGs 

therefore apply only to the permitting of Large CAFOs. For permitting of Medium and Small

CAFOs, permitting authorities will set effluent limitations on a case-by-case basis based on sitespecific conditions. Where deemed appropriate by the permitting authority, the permitting

authority may set effluent limitations for those CAFOs that are similar to the ELG requirements

for Large CAFOs. EPA encourages permitting authorities to consider the discussions below on

the requirements and recommendations for applying the ELG to Large CAFOs when

establishing permit conditions for CAFOs of any size. 

C. How To Use this Document 

Managing Manure contains information pertinent to Large CAFOs in the Dairy Cows and

Cattle other than Veal Calves and the Swine, Poultry, and Veal Calves subcategories of the

final CAFO regulations (see Section E of this chapter). Permit writers, at their discretion on a 

case-by-case basis, may want to consider the information in this manual pertinent to small and

medium CAFOs. The effluent guidelines requirements cited in this manual must be included in 

permits for Large CAFOs, while the permit writer may include them in permits for smaller

CAFOs at the permit authority’s discretion. This manual assumes readers have a basic 

understanding of the CAFO regulations. Text boxes in each section provide the relevant

regulatory language, additional clarifications, and examples for key concepts. 

1-1
Chapter 1: Introduction 

Managing Manure is organized into eight chapters and 15 appendices: 

C Chapter 2 identifies and discusses the production area requirements of the

CAFO rules, example technologies that may help a facility comply with the

production area requirements, and additional voluntary practices that may benefit

operators of many Large CAFOs. 

C Chapter 3 identifies the requirements prior to land application of manure, litter,

and process wastewater (i.e., manure sampling and recordkeeping if these

wastes are transferred off site). 

C Chapter 4 describes the land application area requirements of the CAFO rules

(including the Nutrient Management Plan, setback requirements, and

recordkeeping) example management practices that may be used to help comply

with the land application area requirements, and additional voluntary practices

that may benefit operators of most Large CAFOs. 

C Chapter 5 describes the goals and requirements of the voluntary alternative

performance standards for CAFOs, including several detailed case studies that

may help CAFOs and Permit Authorities develop their own voluntary alternative

performance standards. 

C Chapter 6 provides guidance and case studies for the development and use of

Technical Standards for land application. 

C Chapter 7 describes the most common deficiencies found at CAFOs, identifies

practices to help avoid them, and includes some case studies of management

practices CAFOs may use to help achieve compliance with the CAFO

regulations. 

C Chapter 8 lists resources for additional help in complying with the regulations. 

C This document also includes several appendices including the regulations found

at 40 CFR, sample inspection checklists, records checklist, sample calculations,

and example methods for manure sampling, and equipment calibration. These 

examples are not binding or required, they are examples of how some Permit 

Authorities have implemented the regulatory

requirements. 

To further assist the user of this document, text boxes in 

each section provide the relevant regulatory language,

additional clarifications, and examples for key concepts.

Regulatory citations are provided in text boxes with a

double line. Examples and clarifications are denoted by

text boxes with a single line. 

D. Other Related Documents 

The Producer’s Guide (Producers’ Compliance 

Guide for CAFOs, EPA, 2003) gives a general

description of the revised CAFO regulations and helps

an animal feeding operation (AFO) determine whether

they might be regulated under the revised regulations. 

The Permit Guidance (Permit Writers Guidance 

Manual and Sample NPDES Permit for Concentrated 

Animal Feeding Operations, EPA, 2003) provides

information to NPDES permit writers on the permitting 

1-2
Chapter 1: Introduction 

requirements for CAFOs. This Permit Guidance is accompanied by a series of questions and

answers that reiterate the regulatory requirements and provide additional clarity by referring to

corresponding sections of the CAFO final preamble. 

Because they do not describe in detail the full set of federal regulatory requirements for

CAFOs or the pertinent State requirements, neither the Producer’s Guide nor the Permit 

Guidance are intended to be used to ensure that a CAFO is in compliance with all applicable

requirements. Readers are further cautioned that any of these guidance documents may be

revised or amended without notice. 

EPA’s National Agriculture Compliance Assistance Center

(http://www.epa.gov/agriculture/) provides information on environmental requirements affecting

the agriculture industry, including links to resources and publications. This web site is 

continually updated. 

Chapter 8 of this document provides additional resources. 

E. Scope of CAFO Regulations 

The federal regulatory requirements for CAFOs consist of Effluent Limitation Guidelines

and Standards for the CAFOs point source category (40 CFR Part 412), and NPDES permitting

requirements for CAFOs (40 CFR Part 122). In 2003, EPA revised both the effluent guidelines

and NPDES permitting requirements for CAFOs. Among other things, the new regulations

establish manure management performance standards for new and existing CAFOs. Any

NPDES permit issued to a CAFO after April 14, 2003 must contain the revised effluent

guidelines at 40 CFR Part 412. Appendix A of this document contains a copy of these final

rules. CAFOs should read these federal regulations as well as any state regulations for CAFOs,

and should check with the agency that regulates CAFOs in that state to determine permitting

requirements. For more information on EPA’s regulatory authority for the CAFO regulations,

see Section 1 of the Final CAFO Preamble and Chapter 1 of the Development Document for the 

Final Revisions to the NPDES and the Effluent Guidelines for Concentrated Animal Feeding 

Operations, available at <www.epa.gov/npdes/caforule>. 

The NPDES permitting regulations

generally define an AFO, among other things, AFO Definition 

as an operation where livestock or poultry are §122.23 (b)(1) Lot or facility (other than an confined for an extended period of time (see aquatic animal production facility) where animals 40 CFR 122.23 (b)(1) for the legal definition). (other than aquatic animals) have been, are, or This definition is intended to differentiate will be stabled or confined and fed or maintained confinement-based operations from pasture- for a total of 45 days or more in any 12-month based operations, where the latter are period: intended to be excluded from the CAFO 

regulations. AND 

Where crops, vegetation, forage growth, or postmeets the definition of an AFO and it confines

An operation is a Large CAFO if it 

harvest residues are not sustained in the normal 

growing season over any portion of the lot or at least: facility. 

C 700 mature dairy cows;

C 1,000 beef cattle or heifers;

C 1,000 veal calves; C 2,500 swine (each 55 pounds or more); C 10,000 swine (each under 55 pounds);

C 30,000 chickens (liquid manure handling systems);

C 125,000 chickens except laying hens (other than liquid manure handling

systems);

C 82,000 laying hens (other than liquid manure handling systems);

C 55,000 turkeys;

1-3
Chapter 1: Introduction 

C 5,000 ducks (liquid manure handling systems); C 30,000 ducks (other than liquid manure handling systems); C 500 horses; or 

C 10,000 sheep or lambs. 

The CAFO regulations also use the terminology

“Medium CAFOs” and “Small CAFOs;” these terms are 

generally not used in this document. For more information 

on the definition of a CAFO, consult the Permit Guidance 

as well as Chapter 2 of the Development Document for the 

Final Revisions to the National Pollutant Discharge

Elimination System Regulation and the Effluent Guidelines

for Concentrated Animal Feeding Operations. Both of 

these documents can be found on the Internet at 

<www.epa.gov/npdes/caforule>. 

The effluent guidelines referred to in this document

vary depending on whether the CAFO is currently

operating at the time that the regulations were revised or if

construction of the operation began after April 14, 2003.

Newly constructed CAFOs, and certain CAFOs expanding

the size of their operation may be subject to more stringent

requirements known as New Source Performance

Standards (NSPS). For more information consult the 

Permit Guidance as well as the guidance memorandum

entitled "New Source Determinations for Direct and Indirect 

Dischargers" and 2004 memorandum entitled “Clarification

Regarding CAFOs in 10-Year Protection Period.” 

The effluent guidelines are broken into the following subparts, each addressing specific

animal sectors: 

C Subpart A: Horses and Sheep;

C Subpart B: Ducks;

C Subpart C: Dairy Cows and Cattle other than Veal Calves; and C Subpart D: Swine, Poultry, and Veal Calves. 

Managing Manure focuses only on the animal operations with new or revised effluent

guidelines, specifically Subparts C and D (beef cattle, dairy cattle, veal calves, swine, chickens, 

and turkeys). Though the effluent guidelines for horses, sheep, and ducks have not changed,

these facilities may be subject to revised or additional requirements under the revised NPDES

permitting requirements for CAFOs at 40 CFR Part 122. Even for AFOs that are not regulated

as CAFOs, EPA encourages all owners and operators of those AFOs to review the practices

described in this guidance manual and consider adopting those practices that are applicable to

their operation. 

F. CAFOs with No Potential to Discharge 

The NPDES CAFO regulations require all CAFOs to apply for a permit. EPA recognizes

that, although they may be infrequent, there may instances where a CAFO truly does not have a

potential to discharge. Therefore, an exception is that in lieu of a permit application, Large

CAFOs can request a “no potential to discharge” determination from the permitting authority

where there is no potential for any CAFO manure, litter, or process wastewater to be added to

waters of the United States under any circumstances or climatic condition. If the permitting

authority makes a determination that the CAFO has “no potential to discharge”, the operation

would not need to apply for an NPDES permit. Land application discharges from a CAFO are

subject to NPDES requirements. It is important to note that the “no potential to discharge”

determination applies to both the production area and land application areas under the control 

1-4
Chapter 1: Introduction 

of the CAFO. The “no potential to discharge” determination process may include a site visit to

verify the information submitted by the CAFO operator or to gather additional information 

necessary to make the determination. See Figure 1-1 for an example CAFO that might be able

to make a demonstration of no potential to discharge. 

For more information on supporting a request for a “no potential to discharge”

determination, see section 3.3.5 of the Permit Guidance, available on the internet at 

http://www.epa.gov/npdes/pubs/cafo_permit_guidance_chapters.pdf 

Figure 1-1. Example CAFO Potentially Demonstrating No Potential to Discharge 

G. Comments on Managing Manure 

This document may be revised or amended periodically without public notice. EPA 

welcomes public comments on this document at any time, and will consider those comments in 

any future revision of this document. Comments, including additional helpful information, may

be submitted electronically to Paul Shriner at shriner.paul@epa.gov, or mailed to: 

U.S. EPA

Engineering and Analysis Division 4303T

1200 Pennsylvania Avenue, N.W.

Washington, D.C. 20460

1-5
CHAPTER 2: OPERATION, MAINTENANCE, AND RECORDKEEPING REQUIREMENTS FOR€

THE PRODUCTION AREA ............................................. 2-1€

A. Design Standards .............................................. 2-4€

1. Adequate Storage for Manure, Litter, and Process Wastewater ..... 2-5€

2. No Discharge for Production Areas ........................... 2-8€

B. Proper Operation and Maintenance ............................... 2-10€

1. Liquid Storage Structures ................................. 2-11€

2. Solid Storage Structures .................................. 2-19€

3. Visual Inspections ....................................... 2-19€

Figures 

2-1. Production Area at Whole Milk Dairy ....................................... 2-3€

2-2. Cross Section of Properly Designed Lagoon ................................ 2-14€

2-3. Schematic of Lagoon Depth Marker ....................................... 2-17€
Chapter 2: Requirements for the Production Area 

CHAPTER 2: OPERATION, MAINTENANCE, AND RECORDKEEPING REQUIREMENTS 

FOR THE PRODUCTION AREA 

This chapter discusses the operation, 

maintenance, and recordkeeping requirements 

for a CAFO production area. The production 

area at a CAFO includes the animal 

confinement area, the manure storage area, 

the raw material storage area, and the waste 

containment area. It also includes areas 

where eggs are washed or processed and 

areas used for the storage, handling, 

treatment, or disposal of dead animals (i.e., 

mortalities). Throughout this chapter, “manure” 

means manure, litter, and manure combined 

with other process wastewaters. The terms 

“process wastewaters,” “production area,” and 

“land application area” are also used 

throughout this chapter. The effluent 

guidelines described in this chapter apply only to Large CAFOs. The NPDES requirements 

apply to all CAFOs. This document uses “CAFO rules” to mean both the effluent guidelines and 

the NPDES permit requirements. Permit writers, at their discretion on a case-by-case basis, 

may want to consider the information in this chapter pertinent to small and medium CAFOs on a 

case-by-case basis. The legal definitions are 

provided in the text box on the next page. 

Runoff from raw material storage such 

as silos and feed bunkers is included in the 

definition of process wastewater, and must be 

handled to meet the effluent guidelines 

production area requirements. Some 

examples of water that come into contact with 

raw materials, products, or byproducts include 

water that comes into contact with spilled feed, 

contaminated milk, spent foot bath water, and 

other trace quantities of chemicals used at the 

operation. 

Photo by USDA NRCS 

Production areas include all of the 

following: 

C­ Animal confinement area - area within a CAFO where animals are confined for a 

period of time for feeding or maintenance purposes. 

C­ Manure storage area - area where manure and other wastes (e.g., bedding, 

compost, raw materials commingled with manure, or flush water) collected from 

the animal confinement area are stored or treated prior to final disposal. 

2-1€
Chapter 2: Requirements for the Production Area 

C­ Raw-materials storage area -

area where materials used in 

an animal feeding operation 

are stored. 

C­ Waste containment area -

area where wastes other than 

manure (e.g., contaminated 

storm water) from the 

production area are contained 

prior to final use or disposal. 

All field storage and stockpiles of 

manure and raw materials are defined as 

production area. A CAFO may have more 

than one production area. For example, a 

poultry operation may have long term litter 

storage sheds or stockpiles (manure storage 

areas) that are remotely located from the 

poultry houses (animal confinement areas); 

or a CAFO may handle mortalities at an area 

remotely located from the animal 

confinement area. The CAFO requirements 

apply to all such production areas. 

The definition of “production area” 

makes no distinction between short-term or 

temporary storage areas. Note in particular, 

however, that at layer and broiler operations, 

whether uncovered stockpiles of litter exist 

only temporarily or for a longer period of time 

can make a difference as to the facility’s 

regulatory status. At these operations, 

uncovered stockpiles of litter generally 

constitute a “liquid manure handling system,” 

and operations with a liquid manure handling 

system are defined in the regulations as 

Large CAFOs at a lower threshold number of 

animals than other operations. However, the 

permit authority may authorize some limited 

period of no more than 15 days for temporary 

storage of litter (e.g., where this time is 

needed to allow for contract hauling 

arrangements), within which time the 

uncovered stockpile of litter would not be 

Process Wastewater, Production Area, and 

Land Application Definitions 

§412.2(d) Process wastewater means water 

directly or indirectly used in the operation of the 

CAFO for any or all of the following: spillage or 

overflow from animal or poultry watering 

systems; washing, cleaning, or flushing pens, 

barns, manure pits, or other CAFO facilities; 

direct contact swimming, washing, or spray 

cooling of animals; or duct control. Process 

wastewater also includes any water which 

comes into contact with any raw materials, 

products, or byproducts including manure, litter, 

feed, milk, eggs, or bedding. 

§412.2(h) Production area means that part of 

an AFO that includes the animal confinement 

area, the manure storage area, the raw 

materials storage area, and the waste 

containment areas. The animal confinement 

area includes but is not limited to open lots, 

housed lots, feedlots, confinement houses, stall 

barns, free stall barns, milkrooms, milking 

centers, cowyards, barnyards, medication pens, 

walkers, animal walkways, and stables. The 

manure storage area includes but is not limited 

to lagoons, runoff ponds, storage sheds, 

stockpiles, under house or pit storages, liquid 

impoundments, static piles, and composting 

piles. The raw materials storage area includes 

but is not limited to feed silos, silage bunkers, 

and bedding materials. The waste containment 

area includes but is not limited to settling 

basins, and areas within berms and diversions 

which separate uncontaminated storm water. 

Also included in the definition of production area 

is any egg washing or egg processing facility, 

and any area used in the storage, handling, 

treatment, or disposal of mortalities. 

§412.2(e) Land application area means land 

under the control of an AFO owner or operator, 

whether it is owned, rented, or leased, to which 

manure, litter, or process wastewater from the 

production area is or may be applied. 

deemed to be a liquid manure handling system. See Chapter 1 of this document and section 

3.2.3 of the Permit Writers’ Guidance for more information. 

The production area definition does not include the owner/operator’s office or 

homestead, and does not include the field areas to which manure and process wastewater may 

2-2€
Chapter 2: Requirements for the Production Area 

Figure 2-1. 

be applied as nutrients for crop growth. 

production area is indicated by the dashed line. 

As a standard NPDES permit condition (see Section A of this chapter), all CAFOs are 

required to properly operate and maintain all facilities and systems of treatment and control 

which are installed or used to achieve compliance with the conditions of their permit. 

CFR 122.41(e). 

Management Plan (NMP) which must include, to the extent applicable, a set of nine minimum 

practices, including the following specific activities that apply to the operation and maintenance 

of a CAFO production area (see 40 CFR 122.42(e)): 

C Ensure adequate storage for manure, litter, and process wastewater, including 

procedures to ensure proper operation and maintenance of the storage facilities; 

C Ensure proper management of mortalities (i.e., dead animals) to ensure that they 

are not disposed of in a liquid manure, storm water, or process wastewater 

storage or treatment system that is not specifically designed to treat animal 

mortalities; 

C Ensure that clean water is diverted, as appropriate, from the production area; 

Production Area at Whole Milk Dairy 

See Figure 2-1 for an illustration of a dairy; the 

See 40 

In addition, the CAFO rules require each CAFO to have a Nutrient 

2-3€
Chapter 2: Requirements for the Production Area 

C Prevent the direct contact of confined animals with waters of the United States; 

C­ Ensure that chemicals and other contaminants handled on-site are not disposed 

of in any manure, litter, process wastewater, or storm water storage or treatment 

system unless specifically designed to treat such chemicals and other 

contaminants; 

C­ Identify appropriate site-specific conservation practices to be implemented, 

including as appropriate buffers or equivalent practices, to control runoff of 

pollutants to waters of the United States; 

C­ Identify protocols for appropriate testing of manure, litter, process wastewater, 

and soil; 

C­ Establish protocols to land apply manure, litter, or process wastewater in 

accordance with site specific nutrient management practices that ensure 

appropriate agricultural utilization of the nutrients in the manure, litter, or process 

wastewater; and 

C­ Identify specific records that will be maintained to document the implementation 

and management of the minimum elements described above. 

The following sections elaborate on each of these activities by describing both the 

required NPDES conditions as well as the applicable requirements from the effluent guidelines. 

The remainder of this chapter covers the CAFO’s requirements for the following topics: design 

standards, proper operation and maintenance, mortalities, direct contact, chemical disposal, 

records, and additional voluntary controls. 

A. Design Standards 

The CAFO rules prohibit the 

discharge of manure, litter, and other process 

wastewaters from the production area, 

except for allowing a discharge when rainfall 

causes an overflow from a storage structure 

designed, constructed, maintained, and 

operated to contain all manure, litter, and 

process wastewaters, including storm water, 

plus runoff and the direct precipitation from a 

25-year, 24-hour rainfall event. By requiring 

adequate storage (see 40 CFR 

Additional Conditions Applicable to 

CAFOs 

§122.42(e)(1)(i) Ensure adequate storage 

of manure, litter, and process wastewater, 

including procedures to ensure proper 

operation and maintenance of the storage 

facilities. 

122.42(e)(1)(i)) plus the capacity for 25-year, 24-hour rainfall event (see 40 CFR 

412.31(a)(1)(i)), the CAFO rules help to ensure that discharges of manure from a production 

area to waters of the U.S. are minimized or eliminated. At the same time, the CAFO rules 

provide a CAFO that has properly designed, constructed, maintained, and operated its facility 

with an allowance under its permit for a discharge from the production area in the case of 

uncontrollable rainfall events (see Example 2-1). 

2-4€
Chapter 2: Requirements for the Production Area 

Example 2-1. Design Standards that Comply with the Clean Water Act 

A permitted CAFO’s waste handling system has the capacity to contain the expected volume 

of runoff from a 25-year, 24-hour rainfall event plus four month’s worth of average daily 

process wastewater. Note that the definition of “process wastewater” includes contaminated 

runoff (see 40 CFR 412.2(d)). An unusually long and wet winter precludes the operator from 

dewatering the storage facility. It rains heavily for three weeks (a chronic rainfall), but the 

rainfall in any 24-hour period never exceeds the 25-year, 24-hour storm event. The facility’s 

waste handling system reaches capacity and the resulting overflow discharges to a river. 

Did the CAFOs violate its permit? 

If the CAFO met the requirements of its permit regarding the design, construction, operation 

and maintenance of its waste handling system this overflow due to a chronic rainfall event, 

but less than the 25-year, 24-hour storm, is not a violation of the permit. To ensure that it is 

meeting the requirements of the permit, the CAFO may want to check with its permitting 

authority to verify that the design capacity it has chosen is adequate. For example, the 

permit authority may require additional design capacity to meet Water Quality Standards. 

1. Adequate Storage for Manure, Litter, and Process Wastewater 

CAFOs must ensure adequate storage of manure, litter, and process wastewater, 

including procedures to ensure proper operation and maintenance of the storage facilities (see 

40 CFR 122.42(e)(1)(i)). Having adequate storage for all manure and wastewater provides 

flexibility to schedule land application of manure nutrients when weather and field conditions are 

suitable and when nutrients in the manure can best be used by crops. The link between 

adequate storage and land application practices is one of the most critical considerations in 

successfully developing and implementing a site-specific Nutrient Management Plan. In fact, 

the capacity for the 25-year, 24-hour storm event (or the 100-year, 24-hour storm, where 

appropriate) is just one component in determining overall storage capacity. Equally important is 

to ensure the capacity needed to store manure and wastes during those periods when land 

application is prohibited under a states’ technical standards (see Chapter 4). Adequate storage 

will help CAFOs meet the land application practices specified in their NMP, the best 

management practices required for land application of manure and process wastewater, and will 

help CAFOs meet realistic production goals while minimizing nitrogen and phosphorus 

movement to surface waters, as required by the effluent guidelines for Large CAFOs (40 CFR 

412.4(c)(1)). See Chapter 4 of this manual for more information on Nutrient Management Plans 

and land application requirements. See Cost Methodology for the Final Revisions to the 

NPDES and Effluent Guidelines for CAFOs (EPA 821-R-03-004) and Development Document 

for the Final Revisions to the NPDES and Effluent Guidelines for CAFOs (EPA 821-R-03-001) 

for additional information on adequate storage. 

Adequate storage is not defined by the CAFO regulations. Adequate storage is based 

on a site-specific evaluation of the CAFO’s entire waste handling system. Factors such as rainy 

seasons and storage capacity for the winter are relevant and are readily factored into the proper 

design and construction of any storage facility; see Example 2-2A. Also see Section B.1 of this 

chapter: Liquid Storage Structures and the accompanying text box on chronic rainfalls. 

Adequate storage is also affected by the individual CAFO’s operation and maintenance 

2-5€
Chapter 2: Requirements for the Production Area 

schedule and the site-specific Nutrient Management Plan; see Example 2-2B. CAFOs should 

also evaluate storage capacity and the adequacy of the existing waste handling system when 

the facility undergoes significant changes such as an expansion of herd size; see Example 2-

2C. CAFOs should further ensure that storage is adequate to avoid pumping water at a nonoptimal time to apply nutrients; see Example 2-2D. An example state regulatory requirement 

that defines adequate storage to include capacity for the winter plus freeboard is in Example 2-

2E. 

For additional information on designing, operating, and maintaining a storage structure, 

see U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) 

Practice Standards 313, Waste Storage Facility, and 359, Waste Treatment Lagoon, and the 

Field Office Tech Guide. These practice standards include information on the foundation of the 

storage pond or lagoon, maximum operating levels, structural loadings for fabricated structures, 

slab designs, and considerations for minimizing the potential for and impacts of sudden breach 

of embankment or accidental release from the required volume. These resources are described 

in more detail in Chapter 8 of this document. 

The CAFO rules do not have specific design requirements for how to choose a site for 

storage structures, or that site’s effect on the design of storage structures. However, CAFOs 

should evaluate the soils, geology, and topography of the site, as well as the location and layout 

of the operation to determine the best storage area for each operation. Animal manure storage 

areas should be built following commonly approved standards (e.g., USDA NRCS standards, 

American National Standard for Good Environmental Livestock Production Practices (ANSI 

GELPP)1

) and should be located away from water bodies, floodplains, drinking water wells, 

shallow ground water, sinkholes, and other environmentally sensitive areas. These standards 

also recommend that the production area is located with adequate separation distances from 

neighbors to minimize visual exposure and disrupt airflow. Where adequate separation is not 

possible, consider installing natural or manmade screening. 

Example 2-2. Examples of Site-Specific Determination of Adequate Storage 

Example A: Capacity for the wet season.€

A feedlot is located in a southern climate where the typical winter is brief and mild. Manure solids are€

separated daily and picked up monthly by a third party hauler. The CAFO schedules wastewater€

irrigation every 21 days to empty the holding pond unless the ground is wet or it is raining at the time of€

scheduled irrigation. The CAFO constructed the holding pond for 21 days of storage. Historical€

records show during the rainy season it typically rains daily for 45 days and the ground remains wet for€

approximately three months. €

1

The ANSI GELPP standards are a compilation of management practices that are commonly applied 

throughout confined livestock production operations. For additional information on siting, see ANSI 

GELPP 0001-2002. For additional information on measures that can be taken to reduce adverse 

environmental impacts of CAFOs, see ANSI GELPP 0002-2002. 

2-6 
Chapter 2: Requirements for the Production Area 

Example 2-2. Examples of Site-Specific Determination of Adequate Storage 

Does the CAFO meet the adequate storage requirements? 

No, the CAFO does not have adequate storage. When designing the holding pond, the CAFO did not 

consider the typical length of time (i.e., three months) that is required during the rainy season between 

emptying events. The CAFO should consider a more proactive operation and maintenance program to 

maintain capacity for the 25-year, 24-hour rainfall event. 

Example B: Capacity Consistent with NMP 

A poultry CAFO has a storage shed that can store the manure and litter removed from the poultry 

houses between each flock (i.e., manure “crust” or “cake”). The remaining manure and litter (i.e., the 

full house cleanout) is removed from the poultry houses once a year in the fall and stockpiled outside 

(the capacity of the shed cannot store a full-house cleanout). The practice does not coincide with the 

nutrient needs of the crops, and does not minimize the transport of nutrients from the crop fields. 

Rather than build additional storage or maintain covered temporary stockpiles, the CAFO coordinates 

with their integrator and arranges for full-house cleanouts to coincide with nutrient needs of the crops in 

the spring. Under the CAFO’s Nutrient Management Plan, 100% of the CAFOs manure and litter is to 

be used for land application. The CAFO has adequate land for all manure and litter produced. These 

practices and procedures are specified in the CAFO’s revised Nutrient Management Plan. The CAFO’s 

records and inspections show complete implementation of the Nutrient Management Plan. 

Does the CAFO meet the adequate storage requirements? 

The CAFO’s revised NMP includes spring cleanouts instead of fall cleanouts. Generally, the CAFO 

would be considered to have adequate storage. 

Example C: Adequate Capacity for Facility Expansion 

A 900 head dairy increases production by expanding the herd size to 1,200 head. The CAFOs original 

treatment lagoon was sized for 900 head. 

Does the CAFO meet the adequate storage requirements? 

No, the CAFO does not have adequate storage. The lagoon was neither sized nor designed to treat the 

manure and process wastewater for an additional 300 head. In addition, the lagoon may now 

experience operational problems due to overloading the treatment system, and may also experience 

significant increases in odors. 

Example D: Adequate Capacity for Appropriate Utilization of Nutrients 

A 1,500 head beef feedlot is located in a mild climate, and the state’s technical standards do not 

prohibit land application in the winter. The CAFO has a highly efficient solids separation system, a 

concrete holding pad for solids storage during inclement weather, and applies the manure solids as 

fertilizer in accordance with a Nutrient Management Plan. Any wastewater and runoff is directed to an 

evaporation pond sized solely for runoff from the 25-year, 24-hour storm event. Every year during the 

rainy season the wastewater accumulates until rainfall events fill the evaporation pond, overflows 

across a field, and discharges to a river. 

Does the CAFO meet the adequate storage requirements? 

No, the CAFO does not have adequate storage. The CAFO has not appropriately addressed the 

pollutants in the wastewater. The CAFO does not have capacity for all manure and process 

wastewater, including the runoff and direct precipitation from a 25-year, 24-hour rainfall event. In 

addition, the lack of adequate storage capacity contributed to the CAFO’s failure to ensure that manure 

application to fields was restricted to rates that would minimize phosphorus and nitrogen transport from 

2-7€
Chapter 2: Requirements for the Production Area 

Example 2-2. Examples of Site-Specific Determination of Adequate Storage 

the fields to waters of the U.S. (see 40 CFR 412.4(c)(1)). For example, the feedlot’s design is such that 

the facility cannot store process wastewater during those periods when the fields are saturated. 

Furthermore, the annual occurrence of discharges from the CAFO’s wastewater storage pond suggests 

the CAFO has not appropriately considered the rainy season in the design and construction of the 

pond. 

Example E: Sample State Regulation to Define Adequate Storage 

Storage structures containing manure with less than 20% total solids and exposed to precipitation must 

maintain a minimum freeboard of one foot at all times. This is in addition to the capacity 

needed to contain direct precipitation and runoff from the 25-year, 24-hour storm. For facilities with a 

drainage area, the storage structure must also have capacity to contain precipitation and runoff from the 

drainage area during the storage period. Adequate manure storage volume shall be provided and 

maintained to prevent the necessity of land applying manure on frozen and/or snow covered ground or 

periods of soil saturation. No later than September 15 of each year, the CAFO shall evaluate the 

storage capacity in their manure storage or treatment facilities and determine what steps are needed to 

avoid the need to land apply manure on frozen or snow covered fields for the upcoming winter. The 

operating record for the facility shall include documentation of the storage level as well as what was 

considered in this evaluation, and what actions were taken to avoid the need for land application of 

manure on frozen or snow covered ground. Failure to perform the evaluation or failure to take action if 

the evaluation indicates that action was necessary to avoid land application on frozen or snow covered 

ground shall be considered a violation of the permit. 

2. No Discharge for Production Areas 

The CAFO effluent guidelines require 

all Large dairy cow, cattle, veal calf, swine, 

chicken, and turkey CAFOs to meet a no 

discharge standard. This means there can 

be no addition of any pollutant or 

combination of pollutants to waters of the 

U.S. under any climatic circumstances (see 

the exception below). The no discharge 

requirement applies to the entire production 

area, including all manure, litter, and process 

wastewater whether stored close to or far 

away from the animal confinement area. 

Process wastewater includes, among other 

things, any water which comes into contact 

with any raw materials, products, or 

Effluent Limitations for the Production 

Area 

§412.31(a) Except as provided in 

paragraphs (a)(1) through (a)(2) of this 

section, there must be no discharge of 

manure, litter, or process wastewater 

pollutants into waters of the U.S. from the 

production area. 

Also §412.32(a), §412.33(a), §412.43(a), 

§412.44(a), and §412.45(a). 

byproducts (see 40 CFR 412.2(d)). Dilution of manure or wastes does not exempt the waste 

stream from the no discharge requirement. 

Even a well-managed facility may experience unusual situations with the potential to 

cause a discharge beyond the operator’s control. Consistent with existing provisions included in 

the NPDES regulations at 40 CFR 122.41, upset and bypass provisions are included as 

standard conditions in all NPDES permits to address the potential for unforeseen 

circumstances. An upset is an unintentional noncompliance event occurring for reasons beyond 

the reasonable control of the permittee. The upset provision in the NPDES permit operates as 

an affirmative defense to prosecution for violation of technology-based effluent limitations, 

2-8€
Chapter 2: Requirements for the Production Area 

provided certain specified criteria are met. For example, flood damage or other severe weather 

damage to containment structures that cannot reasonably be avoided or controlled by the 

permittee could be a basis for an affirmative defense for an upset. A bypass, on the other hand, 

is an act of intentional noncompliance during which waste treatment facilities are circumvented 

under certain specified circumstances, including emergency situations. The bypass provision 

authorizes bypassing to prevent loss of life, personal injury, or severe property damage where 

there are no feasible alternatives to the bypass and where the permitting authority is properly 

notified. See 40 CFR 122.41(m)2

. See the Permit Writers Guide and 40 CFR 122.41(n) for 

more information. In other words, even though the regulations prohibit discharges from the 

production area, a permitted CAFO can claim an upset/bypass defense for events that are 

beyond its reasonable control, including extreme weather events as well as other uncontrollable 

or unforeseen conditions. 

The no discharge requirement in the CAFO rules does not apply to discharges of noncontact storm water. Requirements applicable to storm water discharges are specified at 40 

CFR 122.26(b)(14). EPA generally defines "storm water associated with industrial activity" to 

include storm water discharges from facilities subject to effluent guidelines or New Source 

Performance Standards for storm water. Examples of such areas include immediate access 

roads and rail lines used or traveled by carriers of raw materials, manufactured products, waste 

material, or by-products used or created by the facility; refuse sites; sites used for the storage 

and maintenance of material handling equipment; and shipping and receiving areas. Additional 

permit conditions that apply to storm water discharges are beyond the scope of this document. 

However, CAFOs are encouraged to follow good housekeeping and spill prevention and 

response procedures at all times. 

No Discharge Exception 

If a CAFO chooses to implement minimum design standards for containment (discussed 

in Section A.1 of this chapter), the CAFO may be allowed a discharge. Production area 

discharges from Large CAFOs are permitted only when they consist of weather related 

overflows, and are permitted only in those cases where a storage structure has been designed, 

constructed, operated, and maintained in accordance with the effluent guidelines requirements. 

Only the overflow is a legitimate discharge under the effluent guidelines. Consequently, an 

operation cannot “pull the plug” and empty the runoff control systems simply because an 

overflow is occurring. Proper operation and maintenance of storage structures is discussed in 

the following section. 

2

 One important distinction here is a facility with a “no potential to discharge” determination does not have 

a permit, and is, therefore, not entitled to the upset and bypass provisions. 

2-9 
Chapter 2: Requirements for the Production Area 

B. Proper Operation and Maintenance 

Overflows from production areas are 

only in compliance with 40 CFR Part 412 if 

the facility’s storage structure is properly 

designed, constructed, operated, and 

maintained. CAFOs that do not actively 

maintain the capacity of the storage 

structure, are not entitled to this overflow. 

For example, a CAFO that starts dewatering 

only when the storage structure is completely 

full (such that additional capacity to 

accommodate a 25-year, 24-hour rainfall 

event does not exist) is not deemed “properly 

operated” and any related overflows would 

be in violation of the permit. 

The permissible overflow should be 

limited to the amount necessary to maintain 

the structural integrity of the storage 

Proper Operation and Maintenance 

Proper operation and maintenance (O&M) is 

a standard condition in all NPDES permits 

(40 CFR 122.41(e)). Proper O&M of storage 

structures includes activities such as 

periodic solids removal to maintain storage 

capacity, maintenance of berms and 

sidewalls, prompt repair of any deficiencies, 

and appropriate dewatering activities. 

CAFOs must actively manage storage 

structures to maintain the appropriate 

capacity, including the capacity to contain 

the runoff and precipitation from the 25-year, 

24-hour storm event. 

structure. To reiterate, the overflow allowance does not allow CAFOs to use permissible 

overflows during heavy rainfalls as an opportunity to pump additional process wastewater out of 

the liquid storage structure. 

For an overflow to be allowed, the effluent guidelines also require that the production 

area is operated in accordance with additional practice measures and record keeping 

requirements in the effluent guidelines at 40 CFR 412.31(a)(1)(ii)) in addition to the more 

general operation and maintenance requirements in 122.41. All production areas must be 

operated and maintained to prevent the discharge of pollutants into waters of the U.S. This 

includes, but is not limited to, activities such as: 

1.­ Conducting frequent inspections of storage structures to confirm they have 

adequate storage capacity as specified in 40 CFR 412; 

2.­ Removing solids from storage structures as needed to maintain the design 

storage capacity; 

3.­ Maintaining storage capacity for the design storm event (25-year, 24-hour storm 

event for existing CAFOs and 100-year, 24-hour storm event for new CAFOs); 

4.­ Establishing controls to prevent burrowing animals and plants from eroding 

storage structure berms, embankments, liners, and sidewalls; 

5.­ Stabilizing berms and embankments with vegetation, rock, or other materials to 

prevent erosion; 

6.­ Checking to ensure that all inlets and outlets to the storage structure are not 

blocked by debris or ice; and 

2-10€
Chapter 2: Requirements for the Production Area 

7.­ Visually inspecting the perimeter of any storage structure to ensure any runoff or 

process wastewater is contained. 

The following sections describe recommendations for the proper design, construction, 

operation, and maintenance of storage structures. When designing new or expanded storage 

structures, CAFOs should consider any potential air or ground water impacts. CAFOs should 

also properly handle non-contact storm water, as described in Section A.2 of this chapter. 

Section E of this chapter discusses additional voluntary controls that can be used to minimize 

volatilization and leaching of pollutants. 

1. Liquid Storage Structures 

The minimum design volume for liquid storage structures should be based on the 

maximum length of time between emptying or dewatering events (i.e., the minimum storage 

period); see Example 2-2F. The appropriate frequency of emptying events may vary for each 

CAFO based on factors such as: 

C­ Storage structure size (i.e., if it contains more than the minimum required storage 

capacity); 

C Hydraulic limitations of a land application site; 

C Typical rainfall for the area; 

C Nutrient concentrations in the stored liquid; 

C­ Allowable timing of land application such as winter applications as specified in a 

Nutrient Management Plan; and 

C Extent to which the liquid in the storage structure is used for irrigation water. 

2-11€
Chapter 2: Requirements for the Production Area 

Example 2-2. Examples of Site-Specific Determination of Adequate Storage 

(Continued) 

Example F: Capacity for the winter season 

A swine operation is located in a northern state that prohibits land application of manure to 

frozen, snow-covered, or saturated ground. For the CAFO’s location, the winter season lasts 

about 150 days. The CAFO constructs 150 days of storage (length of the winter season). 

The CAFO plans to land apply manure and process wastewater every six months (before 

and after the main cropping season). 

Does the CAFO meet the adequate storage requirements? 

No, the CAFO does not have adequate storage. The CAFO sized their storage to hold 

manure, litter, and process wastewater generated during the 150-day winter season; 

however, the CAFO’s land application schedule (every six months, or approximately 180 

days) requires a larger storage capacity. To ensure adequate storage, this CAFO should 

take into account the number of days between land application and the start of the 150-day 

winter season; when that number of days is added to the 150-day “no application” period in 

the winter, the amount of necessary capacity might in fact exceed 180 days. 

In most cases, storage is an integral part of overall nutrient management. This minimum storage 

period provides the capacity to store all manure and process wastewater plus rainfall events 

until optimal land application (i.e., the nutrients are needed by the crops, the soil can assimilate 

it, or there is little to no risk for runoff). States will generally establish this period through their 

technical standards for land application, as required by the regulations (see Chapter 6 of this 

manual for more information on technical standards). 

The CAFO rules do not specify exactly how this site-specific total design volume should 

be calculated, but EPA provided clarification on how this should be done in the preamble as 

follows. The total design volume for a liquid storage structure must include an allowance for 

each of the following: 

C­ The volume of manure, process wastewater, and other wastes accumulated 

during the storage period; 

C­ The volume of “normal” precipitation (i.e., precipitation from other than the design 

rainfall event) minus evaporation on the storage structure surface area during the 

entire storage period; 

C­ The volume of runoff from the facility’s drainage area during “normal” rainfall 

events during the storage period; 

C­ The volume of precipitation from the 25-year, 24-hour rainfall event on the 

storage structure surface area; 

C­ The volume of runoff from the facility’s drainage area from the 25-year, 24-hour 

rainfall event; 

2-12€
Chapter 2: Requirements for the Production Area 

C­ In the case of anaerobic waste treatment lagoons, the minimum treatment 

volume; 

C­ The volume of solids remaining in a storage structure after liquids are removed; 

and 

C Necessary freeboard. 

Additional storage may also be required to meet management goals or other regulatory 

requirements. 

The volume of “normal” precipitation for the storage period should reflect all precipitation 

associated with the rainy season at times when dewatering is not possible. (see the text box on 

chronic rainfalls). Frequent overflows are a potential indicator that a CAFO is not meeting its 

permit obligations to ensure adequate storage and to properly manage the facility. 

Chronic Rainfalls 

A storage structure should have capacity for the maximum length of time anticipated 

between emptying events. This storage volume should also accommodate all wastes, 

precipitation, and runoff for this period of time. Therefore, properly designed systems should 

already account for the “rainy season” or the non-growing season typical of the CAFO’s 

location. 

When a series of rainfall events (such as chronic rainfalls) precludes dewatering, the 

remaining capacity of the storage structure is reduced. Even so, it is highly unlikely that any 

given series of storms would result in an overflow, unless the series of storms occurs so 

close to the end of the design storage period that the storage structure is already filled close 

to capacity. When dewatering is not possible, a rainfall event of any size, both smaller and 

larger than the 25-year, 24-hour storm event, could result in an overflow that is in compliance 

with effluent limitations based on 40 CFR Part 412. CAFOs that do not actively maintain the 

capacity of the storage structure, such as CAFOs with minimal capacity, or CAFOs that start 

dewatering only when the storage structure is completely full, are not entitled to this overflow 

allowance. 

The volume needed for storing solids varies by the presence and efficiency of solids 

separation equipment or processes, and the extent to which the liquid storage structure 

provides treatment. The total volume needed for solids accumulation also depends on the 

length of time between solids removal. Facilities that completely agitate a manure pit prior to 

pumping are likely to need less solids storage volume than facilities that only draw irrigation 

water from the top of the liquid storage structure. Facilities that do not intend to remove solids 

for many years at a time will need solids storage volume for that entire period of time. Each 

CAFO must identify the site-specific design basis in their records and maintain a copy of these 

records on site; see Section D of this chapter for more information. 

2-13€
Chapter 2: Requirements for the Production Area 

Freeboard Definition 

The term freeboard is not defined in the CAFO rules, and is not specified by EPA. EPA 

encourages the use of NRCS and American Society of Agricultural Engineers (ASAE) 

standards that use freeboard as a safety feature designed to protect the structural integrity of 

a liquid storage structure. Generally, freeboard is the distance from the top of the maximum 

design storage volume to the top of the storage structure. 

The ASAE standard entitled Design of Anaerobic Lagoons for Animal Waste Management 

(ASAE EP403.3 Dec 98) recommends that freeboard be 0.3 meters (1 ft) for lagoons without 

a drainage area and 0.6 meters (2 ft) for lagoons with a drainage area. States may have 

additional requirements or alternate definitions of freeboard, but generally permitting 

authorities should consider the use of freeboard for additional storage not to be proper 

operation and maintenance. A spillway is often constructed at this level to prevent use of 

the freeboard area as additional storage capacity. Freeboard can vary from one foot in 

cases where inflow to the structure storage is controlled (e.g., influent is pumped into 

storage structure) to two feet when the inflow is not controlled (e.g., runoff from an 

uncovered animal confinement area flows freely into the storage structure). 

The cross section in Figure 2-2 illustrates the design volume requirements for an 

anaerobic treatment lagoon used as the storage structure in a production area. Additional 

storage volumes may be required to meet management goals or other regulatory requirements 

established by the permitting authority. Examples of additional storage volumes include storage 

for when fields are dormant or no cover crop exists; extra capacity for those climates where the 

rainy season is exceptionally heavy or erratic; and additional storage for where land application 

to frozen or snow-covered ground is prohibited. CAFOs should check with their permitting 

authority for additional design requirements for storage structures at a CAFO production area. 

2-14€
Chapter 2: Requirements for the Production Area 

Figure 2-2. Cross Section of Properly Designed Lagoon 

Treatment Lagoons 

A lagoon is one type of liquid storage structure (a runoff pond is another example). 

Lagoons are different from most other liquid storage facilities in that a lagoon is designed to 

biologically treat high pollutant load wastes such as manure and wastewater. In a lagoon, the 

manure becomes partially liquefied and stabilized by bacterial action before eventual land 

application. In contrast, a waste storage pond or runoff pond is not designed to provide 

treatment, and thus is typically smaller than a lagoon. Anaerobic lagoons operate without any 

considerable oxygen present, and are considerably smaller than aerobic lagoons. Aerobic 

lagoons are designed to provide a higher degree of treatment with less odor production, but 

require significantly more surface area and/or mechanical means for increasing the oxygen 

content in the lagoon. Anaerobic lagoons also decompose more organic matter per unit volume 

than aerobic ones. 

Lagoon capacity should be based on the maximum daily loading considering all waste 

streams to be treated by the lagoon. Most agricultural lagoons are anaerobic, which have a 

minimum treatment volume based on the volatile solids (VS) loading. Additional capacity may 

be necessary to accommodate the proper utilization of treated manure on crops. Usually this 

results in a minimum treatment period of several months; see the text box for more information 

on treatment lagoon design. 

2-15€
Chapter 2: Requirements for the Production Area 

Lagoons can be designed as singlestage or multiple-stage lagoons. Lagoons 

may also be used in combination with a 

solids separator, which is a typical 

arrangement for many dairy CAFOs. CAFOs 

should consider multiple-stage lagoons 

where the first cell can be operated as a 

constant volume treatment cell, and the 

subsequent cells can be used for polishing 

and storage. Multiple stage lagoons do not 

require a significantly greater total volume 

than single-stage systems. This approach 

results in a higher quality lagoon effluent, and 

may be helpful where the CAFO has a limited 

land application area or a reduced need for 

manure nutrients on some fields. Many 

CAFOs recycle the treated effluent from a 

treatment lagoon for flushing or cleaning. 

CAFOs should consider the feasibility of 

multiple stage lagoons when designing or 

expanding a lagoon system. 

When anaerobic lagoons biologically 

treat manure, nondegradable solids settle to 

the bottom as sludge. In addition, COD 

(chemical oxygen demand), VS (volatile 

solids), and P (phosphorus) accumulate in 

the sludge. Periodic removal of accumulated 

solids and sludge is necessary to maintain 

the treatment capacity (or minimum treatment 

volume) of the lagoon. The concentration of 

solids and nutrients (particularly phosphorus 

and potassium) in the solids may assist some 

CAFOs with an excess of nutrients or 

shortage of cropland, as this allows CAFO to 

transport the excess nutrients as a 

concentrated sludge much more 

economically than diluted wastewater. Solids 

accumulation beyond the design sludge 

volume is a potential indicator of an 

improperly operated and maintained lagoon, 

and can result from the expansion of the 

CAFO without a corresponding modification 

to the design of the treatment lagoon or 

failure to clean out the lagoon at specified 

intervals. Particularly malodorous lagoons 

may also be an indicator of overloaded or 

improperly maintained lagoons. 

Treatment Lagoon Design 

One reference for design of an anaerobic 

lagoon is the ANSI/ASAE standard EP403.3 

entitled “Design of Anaerobic Lagoons for 

Animal Waste Management.” ASAE’s 

standard on the design of anaerobic lagoons 

states that the lagoon depth should provide 

for a 6.6 foot minimum depth when the 

lagoon is filled to its treatment volume 

elevation which should be at least 1 foot 

above the highest ground water table 

elevation. ASAE also recommends making 

the lagoon as deep as practical to reduce 

surface area and convection heat loss, 

enhance internal mixing, reduce odor 

emissions, promote anaerobic conditions, 

minimize shoreline weed growth problems, 

and reduce mosquito production. This 

standard also provides equations for 

calculating the total lagoon volume and a 

listing of recommended maximum loading 

rates for anaerobic lagoons for animal waste 

in mass of volatile solids per day per unit of 

lagoon volume. The treatment volume is 

sized on the basis of waste load (volatile 

solids or VS) added per unit of volume and 

climatic region. Maximum lagoon loading 

rates are usually based on average monthly 

temperature and corresponding biological 

activity. If odors are of concern, 

consideration is also given to reducing the 

VS loading. 

The NRCS Standard Practice 359 Waste 

Treatment Lagoon, provides information on 

minimum top widths, operating levels, 

embankment elevations, and considerations 

for minimizing the potential of lagoon liner 

seepage. 

Other frequently used references are NRCS’ 

“Agricultural Waste Management Field 

Handbook”, Part 651, National Engineering 

Handbook, ASAE Engineering Practice 

standard ASAE EP393.3 “Manure 

Storages”, and Midwest Plan Service 

publication MWPS-18. 

2-16€
Chapter 2: Requirements for the Production Area 

In addition to solids management and careful attention to lagoon loading rates, other 

important operation and maintenance measures include: 

C Proper start-up procedures whenever lagoons are modified or first operated; 

C­ Protection of interior slopes with vegetation, mulch, stone, or other means to 

prevent erosion of the liner; 

C­ Trimming of vegetation on embankments to prevent roots from digging through 

the liner; 

C­ Inspection of embankments for animals, insects, or worms that may dig through 

the liner; 

C Lagoons should be fenced and warning signs posted to ensure safety; 

C­ Operation at minimum operating liquid level at the beginning of the design 

storage period, especially late fall and early winter; 

C­ Permanent depth markers showing maximum liquid levels and the lowest pumpdown level; and 

C Periodic visual inspections. 

See section 3 of this chapter for more information on visual inspections. 

Evaporative Lagoons 

Some CAFOs send manure and process wastewater to an evaporative lagoon. This is a 

shallow, uncovered lagoon which has a large enough surface area that much of the liquid 

evaporates off the lagoon through exposure to sun and wind. The advantage of this is that 

CAFOs in arid climates may not have to be concerned with land applying effluent. In many 

cases, the amount of wastewater produced is generally small enough when compared to 

evaporation that the lagoon would pose little to no risk of overflow and, therefore, would not 

require any pumping during most years. The level of the surface area increases during the 

winter months when evaporation rates decrease. However, such lagoons have generally been 

designed with more than enough storage to ensure they do not have to be pumped during the 

winter. 

The evaporative lagoon, by design, allows for the water to evaporate while the solids 

and salts remaining in the lagoon accumulate as a concentrated sludge. At some point, the 

solids that accumulate in the evaporative lagoon will require removal. When removed, any land 

application of these solids to crop land must be applied at appropriate agronomic rates, as 

described elsewhere in this guidance document. The accumulated solids are high in organic 

matter, but the nutrients will consist of concentrated phosphorus and little to no nitrogen. Thus 

the major disadvantage of evaporative lagoons is that evaporation causes most of the nitrogen 

to be lost to the air (primarily volatilized as ammonia). 

2-17€
Chapter 2: Requirements for the Production Area 

Depth Markers 

A depth marker is a tool that allows 

CAFOs to manage the liquid level in an 

impoundment to ensure that the 

impoundment has adequate capacity to 

contain direct precipitation and runoff from 

the design rainfall event. Without a depth 

marker, impoundments may fill to a level 

above their capacity, leading to overflows. 

The CAFO rules require that all open surface 

liquid impoundments in a production area 

have a permanent depth marker. The depth 

marker must indicate the minimum capacity 

needed for the runoff and direct precipitation 

Additional Measures 

§412.37(a)(2) Depth Marker. All open 

surface liquid impoundments must have a 

depth marker which clearly indicates the 

minimum capacity necessary to contain the 

runoff and direct precipitation of the 25-

year, 24-hour rainfall event, or, in the case 

of new sources subject to the requirements 

in §412.46 of this part, the runoff and direct 

precipitation from a 100-year, 24-hour 

rainfall event. 

from a 25-year, 24-hour rainfall event. In the case of closed or covered liquid impoundments, 

depth markers allow CAFOs to maintain levels in those impoundments so that accidental 

discharges do not occur. Only open surface liquid impoundments are required to have a depth 

marker, but level indicators are useful management tools for all types of liquid impoundments. 

It is also a good practice to 

indicate the maximum drawdown level 

on the depth marker in a treatment 

lagoon to ensure that the lagoon has 

the volume needed for biological 

treatment and capacity for all solids 

accumulating between solids removal 

events. Figure 2-3 provides an 

illustration of a open surface liquid 

impoundment with a depth marker. 

CAFOs may use remote 

sensors to measure the liquid level in 

an impoundment. Sensors can be 

programmed to trigger an alarm when 

the liquid level changes rapidly or 

when the liquid reaches a critical level. 

The sensor can transmit to a wireless 

receiver to alert the CAFO about an 

impending problem. One advantage of 

a remote sensor is that it can provide 

CAFOs with a real-time warning that 

the impoundment is in danger of 

overflowing. CAFOs may use remote 

sensors to track liquid levels to 

supplement the weekly required 

inspections of all manure and process 

wastewater structures (required 

inspections and associated records 

are described later in this chapter). 

Figure 2-3. Schematic of Lagoon Depth Marker 

Source: Earthern Pits (Basins) for Liquid Livestock Manure 

(November 2000) 

2-18€
Chapter 2: Requirements for the Production Area 

Even though remote sensors are more expensive, the price may be offset by the additional 

assurance they can provide in preventing accidental discharges and circumventing catastrophic 

failures. 

Divert Clean Water From Production Areas 

In some cases, CAFOs may choose to 

collect clean water, roof water, storm water, Additional Conditions Applicable to 

and other water streams that are not otherwise CAFOs 

defined as process wastewater and contain 

them in liquid storage structures (e.g., runoff §122.42(e)(1)(iii) Ensure that clean water is 

ponds). CAFOs located in extremely arid diverted, as appropriate, from the 

climates may decide to collect any and all production area. 

clean water for irrigation. Other CAFOs use 

the additional water to aid in land application of 

manure (e.g., additional water partially dilutes the manure to aid in pumping through irrigation or 

land spreading equipment). CAFOs choosing to collect this water and store it commingled at 

the production area along with their process wastewater must now handle all of the water as 

process wastewater. CAFOs must account for these additional volumes in the design, 

construction, and operation of their storage facilities. Reducing the total volume of process 

wastewater generated in the production area benefits an operation by reducing the volume of 

wastewater that has to be stored, treated, land applied, and disposed of. Smaller volumes of 

process wastewater often translates to smaller storage structures, which has many positive 

environmental and economic advantages. In most cases, it is both appropriate and desirable to 

divert this clean water from the production area. 

CAFOs not including additional volume 

in the storage structures for “clean” storm 

water runoff (e.g., rain falling on roofs of 

buildings and runoff from adjacent lands) must 

prevent clean water from reaching the 

production area. Clean water can be diverted 

from the production area by using earthen 

perimeter controls and roof runoff 

management techniques. 

Earthen perimeter controls usually 

consist of a berm, dike, or channel constructed 

along the perimeter of a site. Simply defined, 

an earthen perimeter control is a ridge of compacted soil, often accompanied by a ditch or 

swale with a vegetated lining, located at the top or base of a sloping area. When properly 

placed and maintained, earthen perimeter controls are effective in controlling the velocity and 

direction of storm water runoff. Used by themselves they do not have any ability to remove 

pollutants and, thus, must be used in combination with an appropriate sediment or waste 

trapping device. Roof runoff management techniques such as gutters and downspouts direct 

rainfall from roofs away from production areas. Roof gutters are illustrated in the picture on the 

right. 

Both earthen perimeter controls and roof management devices must be maintained to 

remain effective. For example, vegetation in a channel (e.g., ditch or swale) that accompanies 

2-19€
Chapter 2: Requirements for the Production Area 

an earthen perimeter control should be mowed periodically to prevent the vegetation from 

decreasing the channel velocity, which could cause the channel to overflow. In addition, the 

original height of a dike in an earthen perimeter control should be maintained; any decrease in 

height due to settling of manure, other solids, or erosion should be corrected. Roof 

management devices such as gutters and downspouts must be cleaned and inspected regularly 

to prevent clogging and to ensure their effectiveness. 

2. Solid Storage Structures 

Examples of solid storage structures 

include storage areas for solid manure such 

as the lower level of high-rise poultry houses, 

sheds for poultry litter, pits, stockpiles, 

mounds in dry lots, compost piles, and pads. 

CAFOs should manage all runoff from these 

areas. Permit authorities may also require 

CAFOs to manage any seepage to 

groundwater from these areas. The floor of 

solid manure storage areas should be 

constructed of compacted clay, concrete, or 

other material designed to minimize the 

movement of wastes beneath the storage 

area. The floor should be sloped toward a 

collection area or sump so that any runoff or liquid can be collected and transferred to a liquid 

manure storage area or treatment system. Also, CAFOs should consider storing stockpiles of 

solid manure under a roof or cover them to exclude precipitation whenever possible. For 

example, poultry litter stockpiled in a field for long term storage should be covered to reduce or 

eliminate the need to collect all runoff from the litter pile. 

3. Visual Inspections 

Visual inspections help ensure proper 

operation and maintenance of the production 

area. Most discharges can be prevented 

through early identification of potential 

equipment and system failures. The CAFO 

rules require periodic inspections of the 

production area. CAFOs should look for the 

following common problems during these 

inspections: 

C­ Seepage through waste storage 

embankments; 

C­ Erosion of waste storage 

embankments; 

C­ Vegetation growing in storage 

areas; 

Visual Inspections 

§412.37(a)(1) There must be routine visual€

inspections of the CAFO production area. €

At a minimum, the following must be€

visually inspected:€

(i) Weekly inspections of all storm water€

diversion devices, runoff diversion€

structures, and devices channelling€

contaminated storm water to the€

wastewater and manure storage and€

containment structure;€

(ii) Daily inspection of water lines, including€

drinking water or cooling water lines;€

(iii) Weekly inspections of the manure,€

litter, and process wastewater€

impoundments; the inspection will note the€

level in liquid impoundments as indicated€

by the depth marker.€

2-20€
Chapter 2: Requirements for the Production Area 

C Animals accessing storage areas; 

C Levels approaching freeboard; 

C Improperly functioning rain gauges; and 

C Improperly functioning irrigation and land application equipment. 

CAFOs must inspect the water lines at the CAFO daily, including drinking water and 

cooling water lines, to ensure they are not leaking. Leaks from these lines can increase the 

volume of wastewater that has to be stored in the production area storage structures and could 

result in the discharge of pollutants from the storage structure. Leaks from these lines can also 

cause what is otherwise a “dry” manure management system to discharge. Leaking water lines 

also can increase water and electricity bills. Many facilities now use automatic shut-off valves to 

detect pressure changes in the water lines. 

Weekly inspections are required for all storm water diversion devices, runoff diversion 

structures, and devices that channel contaminated storm water to the wastewater and manure 

storage and containment structures. These inspections help ensure that the devices (e.g., roof 

gutters) and structures are free from debris and remain in good working condition. 

Weekly inspections are required for manure, litter, and process wastewater 

impoundments. For surface and liquid impoundments, CAFOs should inspect berms for signs 

of structural weakness (e.g., seepage and wind or water erosion). CAFOs must note the depth 

of manure, litter, and process wastewater in any open surface liquid impoundment as indicated 

by the depth marker during the weekly inspections. 

CAFOs must correct all deficiencies found during the daily and weekly inspections as 

soon as possible (see 40 CFR 412.37(a)(3)). CAFOs must keep records to document that the 

corrective actions were taken, and the records must indicate any factors that prevented 

immediate corrective actions from being taken where deficiencies are not corrected within 30 

days (see 40 CFR 412.37(b)). Appendix B contains a sample checklist for the daily and weekly 

inspections required for a Large CAFO production area. CAFOs may consider using this 

checklist to design their production area inspection routine. 

2-21€
C. Mortalities, Direct Contact, and Chemical Disposal .................. 2-21€

1. Management of Animal Mortalities .......................... 2-21€

2. Direct Contact of Animals With Surface Water ................. 2-23€

3. Disposal of Chemicals .................................... 2-23€

D. Records ..................................................... 2-24€

E. Additional Voluntary Controls .................................... 2-25€

1. Groundwater Protection Controls ........................... 2-25€

2. Lagoon Covers ......................................... 2-26€

3. Additional References .................................... 2-27€
Chapter 2: Requirements for the Production Area 

C. Mortalities, Direct Contact, and Chemical Disposal 

To prevent contamination of the 

nation’s waters, the regulations require CAFOs 

to ensure proper management of dead animals 

to ensure that they are not disposed of in any 

liquid manure, storm water, or process 

wastewater storage or treatment system that is 

not specifically designed to treat animal 

mortalities to prevent the direct contact of 

confined animals waters of the U.S. The 

regulations also require CAFOs to ensure that 

chemicals and other contaminants handled onsite are not disposed of in any manure, litter, 

storm water, or process wastewater storage or 

treatment system unless the system is 

specifically designed to treat such chemicals 

and other contaminants. CAFOs must 

properly handle animal mortalities, prevent 

Mortality Handling 

§122.42(e)(1)(ii) Ensure proper management of 

mortalities (i.e., dead animals) to ensure that 

they are not disposed of in a liquid manure, 

storm water, or process wastewater storage or 

treatment system that is not specifically 

designed to treat animal mortalities. 

§412.37(a)(4) Mortalities must not be disposed 

of in any liquid manure or process wastewater 

handling system, and must be handled in such a 

way as to prevent the discharge of pollutants to 

surface waters, unless alternative technologies 

pursuant to §412.31(a)(2) and approved by the 

Director are designed to handle mortalities. 

animals from direct contact with surface water, and properly dispose of chemicals. These 

regulatory requirements are discussed below. 

1. Management of Animal Mortalities 

Despite improved health and production practices, intermittent mortality occurs at animal 

feeding operations. In some cases, a CAFO 

may need to handle catastrophic mortality. 

The CAFO should ensure the proper 

handling and disposal of dead animals to 

ensure biosecurity, to avoid creating 

nuisance conditions, and to manage any 

pathogens decaying carcasses produce. All 

CAFOs must not dispose of dead animals in 

a liquid manure, storm water, or process 

wastewater storage or treatment system 

unless the system is designed specifically to 

treat mortalities (see 40 CFR 

122.42(e)(1)(ii)). In addition, Large CAFOs 

subject to the effluent guidelines may not 

dispose of mortalities in any liquid manure or Photo by USDA NRCS 

process wastewater system unless 

alternative technologies pursuant to the Voluntary Alternative Performance Standards have 

been approved by the Director (see 40 CFR 412.37(a)(4)). For example, homogenization of 

mortalities may be an appropriate method of treatment, but subsequent disposal in a runoff 

pond is not. 

Mortality disposal methods include burial, composting, incineration, and rendering. 

CAFOs should determine the most appropriate method based on the type(s) of animal(s) 

maintained at the operation, state and local laws, and storage capabilities. For example, many 

poultry producers previously used fabricated pits for burying dead birds, but due to potential 

2-21 
Chapter 2: Requirements for the Production Area 

contamination of groundwater from pollutants leaching from these pits, many states now prohibit 

burial. Currently, many poultry producers compost dead birds between layers of litter and straw. 

In many states, burial is now allowed only during instances of catastrophic mortality. 

Due to the size of cattle carcasses, frequency of autopsies, and economics of mortality 

handling, most beef and dairy cow producers use rendering as their primary method of mortality 

disposal. Swine producers bury, incinerate, render, and compost their dead animals. During 

the last several years, however, more swine producers have switched from burial to 

composting. 

CAFOs should consider incorporating a mortality management strategy into the Nutrient 

Management Plan that includes the following five components identified in ANSI GELPP 005-

2002 Mortality Management: 

C A schedule for collecting, storing, and disposing of carcasses; 

C A description of how mortalities will be stored on site prior to disposal; 

C A description of the final method for mortality disposals; 

C­ A contingency plan that addresses reasonable foreseeable issues such as mass 

mortality due to mechanical failures or weather, loss of contract transporter for 

rendering, and euthanization due to disease outbreaks; and 

C Records of mortality disposal (e.g., date, numbers of animal, final disposition). 

To prevent the transmission of possible diseases, CAFOs should try to remove all carcasses 

from the animal living areas within 24 hours, minimize insect and rodent populations in the 

mortality storage areas, and use mortality storage areas with impermeable bases. Below are 

specific recommendations for each mortality disposal method as described in the ANSI Mortality 

Management standard: 

C­ Off-Site Rendering: The CAFO’s contingency plan should include at least one 

alternative carcass hauler and, if practical, one alternative rendering facility or 

other facility capable of properly disposing of carcasses. 

C­ Composting: CAFOs must ensure that clean water is diverted from the 

composting areas. The composting facility should be constructed with an 

impermeable base and roofed, carcasses should be prepared properly for 

composting, carcasses should be placed in the compost structure properly, and 

all carcasses should be covered completely by the compost amendment. 

C­ Burial: CAFOs should ensure that the burial locations are not in sensitive areas 

(e.g., floodplains, areas with shallow water tables, sandy soils, near surface 

water, or near groundwater wells), carcasses are prepared properly, and 

carcasses are covered properly. 

2-22€
Chapter 2: Requirements for the Production Area 

C­ Incineration: CAFOs should ensure that the incinerator is operational, the 

capacity of the incinerator is not exceeded, and the incinerator is maintained and 

secured properly. 

Additional information on the proper management of animal mortalities can be found in “NRCS 

Practice Standard Animal Mortality Facility-316.” This standard provides information for using 

freezer units, disposal and burial pits, incinerators, and considerations for planning normal and 

catastrophic animal mortality management. 

2.­ Direct Contact of Animals With 

Surface Water 

To help ensure that wastes generated 

by animals confined in a production area do 

not contaminate waters of the U.S., CAFOs 

must prevent direct contact by the animals with 

such waters. Direct contact means an animal 

is standing in a water body or walks through it. 

For example, if a cow walks through a stream 

in a production area, there is direct contact 

with the stream by the cow. Fences are a 

common method of preventing animals from 

contacting surface water bodies. CAFOs that 

use fencing in the production area to control 

animals’ access should check fence lines 

regularly and repair any damaged sections as 

soon as they are identified. CAFOs should 

also provide an alternative water source for the 

Additional Conditions Applicable to CAFOs 

§122.42(e)(1)(iv) Prevent direct contact of 

confined animals with waters of the United 

States. 

animals to discourage walking through 

streams. 

3. Disposal of Chemicals 

CAFOs must not dispose of chemicals 

and other contaminants handled on-site into a 

manure, litter, process wastewater, or storm 

water storage or treatment system unless the 

system is specifically designed to treat these 

chemicals and other contaminants. If the 

storm water storage or treatment system is not 

designed to handle chemicals and other 

contaminants, disposing of the materials in 

those systems could cause the treatment 

Photo by USDA NRCS 

Additional Conditions Applicable to CAFOs 

§122.42(e)(1)(v) Ensure that chemicals and 

other contaminants handled on-site are not 

disposed of in any manure, litter, process 

wastewater, or storm water storage or treatment 

system unless specifically designed to treat 

such chemicals and other contaminants. 

system to fail, and could discharge pollutants. For example, expired or wasted antibiotics must 

not be disposed of in a confinement building pit or flushed out of hospital pens into the liquid 

manure storage areas. Biological treatment systems such as lagoons and digesters are 

sensitive to certain chemical loads, and these treatment systems could fail. 

CAFOs should minimize the use of potentially harmful chemicals/contaminants and 

ensure these products are used and disposed of properly. For example, it may not be 

2-23€
Chapter 2: Requirements for the Production Area 

consistent with chemical labels to dispose of rinse water from spent chemical containers in the 

storage structure. The permit may specify additional restrictions and controls for these trace 

chemicals where necessary. To properly dispose of any chemical, operators should follow 

instructions provided on labels or documentation from the supplier. 

D. Records 

CAFOs must keep records to 

document that the design, operation, and 

maintenance requirements for a CAFO 

production area described above are met. 

These records must be kept for a minimum 

period of five years after they are created. 

See 40 CFR 122.42(e)(1)(ix) and (e)(2). 

CAFOs must make these records available to 

the Director or his or her designee. 

The CAFO must keep the following 

production area records: 

C­ Specific records that will be 

maintained to document the 

implementation and 

management of the minimum 

elements listed in §122.42(e), 

including: ensure adequate 

storage; ensure proper 

management of mortalities; 

clean water diversions; prevent 

direct contact of animals; 

ensure proper chemical 

disposal. 

Recordkeeping 

§122.42(e)(2) The permittee must create, 

maintain for five years, and make available to 

the Director, upon request, the following 

records... 

§122.42(e)(3) ...Large CAFOs must retain for 

five years records of the date, recipient name 

and address, and approximate amount of 

manure, litter, or process wastewater 

transferred to another person. 

§412.37(b) Each CAFO must maintain on-site 

for a period of five years from the date they are 

created a complete copy of the information 

required by 40 CFR 122.21(i)(1) and 40 CFR 

122.42.(e)(1)(ix) and the records specified in 

paragraphs (b)(1) through (b)(6) of this section. 

The CAFO must make these records available 

to the Director and, in an authorized State, the 

Regional Administrator, or his or her designee, 

for review upon request. 

C­ Documentation of all required visual inspections (see Section B.3 of this chapter). 

Note that though visual inspections of water lines are required daily, the record 

may consist of a signed weekly log assuring the inspections were conducted. 

See the Producers Guide for more information. 

C­ Weekly records of the depth of the manure and process wastewater in the liquid 

impoundment as indicated by the depth marker. See Section B.1 of this chapter. 

C Records documenting any actions taken to correct observed deficiencies. 

C­ Explanation of the factors preventing immediate correction of deficiencies, for 

deficiencies not corrected within 30 days. 

C­ Records of mortality management and practices used by the CAFO to meet the 

requirements for mortalities handling and disposal. 

2-24€
Chapter 2: Requirements for the Production Area 

C­ Records documenting current design of any manure or litter storage structures, 

including volume for solids accumulation, design treatment volume, total design 

volume, and approximate number of days of storage capacity. The 

documentation should also reflect any significant changes to these systems, 

such as changes to the waste handling system due to expanded or reduced 

number of animals. 

C Records of the date, time, and estimated volume of any overflow. 

Appendix C contains a sample checklist for the records that must be kept for a production area 

at a Large CAFO. 

E. Additional Voluntary Controls 

In addition to the requirements described above, there are many other controls that 

CAFOs can implement to increase the efficiency and environmental protection of storage 

structures. CAFOs should consult their state and local regulatory authorities to make sure 

these voluntary controls are not already required or prohibited. Examples of voluntary controls 

include groundwater protection controls and lagoon covers. They are discussed below. 

1. Groundwater Protection Controls 

Various controls are available to reduce the potential for the discharge of pollutants to 

the groundwater. These include, but are not limited to, storage structure liners and groundwater 

monitoring. 

Liners prevent pollutants from leaching into the groundwater from the bottom and sides 

of a storage structure. They can be made of natural (e.g., heavy clay) or synthetic (e.g., plastic 

or rubber) materials. To be effective, liners must be inspected periodically to ensure they are 

not leaking. CAFOs should check with their permitting authority for any state requirements 

concerning lagoon liners. For example, California currently requires waste management units at 

CAFOs to be lined with or underlined with soils containing at least 10 percent clay and not more 

than 10 percent gravel or artificial materials of equivalent impermeability; Idaho currently 

requires a 2-foot compacted layer of heavy soil, concrete or asphalt, or synthetic membrane 

liners. Other states may also require additional monitoring or controls to protect groundwater 

(and drinking water) resources. 

Groundwater can be monitored periodically to check for pollutant infiltration from a 

storage structure. Monitoring provides an early warning that there may be a problem with a 

storage structure and allows early correction of the problem. Monitoring typically requires 

installing at least one well up-gradient and two to three wells down-gradient from the storage 

structure. CAFOs should conduct a comprehensive hydrological assessment prior to installing 

the monitoring wells to ensure that the wells are located properly to detect pollutant releases to 

the groundwater. Groundwater in some areas is susceptible to seasonal variations of flow and 

may even change directions of flow. Monitoring of the groundwater beneath a storage structure 

in a production area is a good idea in areas where there is a strong likelihood of pollutants 

reaching the groundwater. These situations include areas where the storage structure is 

located over karst terrain and where the groundwater table is very shallow. 

2-25€
Chapter 2: Requirements for the Production Area 

Note that ground water controls may not always be voluntary. On a site-specific basis a 

NPDES permit may set additional requirements on groundwater discharges where the 

groundwater has a direct hydrologic connection to surface water. In addition as noted above, a 

CAFO may be subject to certain ground water controls based on state or local regulatory 

authorities that are separate from the Clean Water Act NPDES requirements. The CAFO 

should consult with their state permit authority for more information. 

2. Lagoon Covers 

Though the CAFO rules do not require 

the use of lagoon covers, one way to reduce 

the potential for pollutant discharges from 

storage lagoons is to install an impermeable 

cover over the lagoons. Covered lagoon 

systems have been used successfully in all 

areas of the country including cold climates. 

They can now be designed and constructed 

from materials to resist freezing, high winds, 

and other extreme weather conditions that may 

have precluded their use in the past. 

However, in some instances, covers are an 

attractive alternative to help reduce the 

potential for pollutants discharged to surface 

water bodies by decreasing the volume of 

storm water that has to be stored. Therefore, CAFOs may be able to design a smaller lagoon to 

manage all manure and wastewater if it is covered. This will minimize the amount of land that 

has to be devoted to the impoundment and, in turn, reduces excavation costs. In wet climates, 

the use of covers can drastically reduce the costs of land application and hauling of manure by 

eliminating a lot of non-contact water, especially direct precipitation. In many cases the use of a 

cover can reduce evaporation and the associated loss of nitrogen which in turn may result in 

significant odor reduction. The additional conserved nitrogen can often be beneficially used by 

crops. Volatilization of nitrogen is generally viewed as unfavorable, and new treatment 

technologies specifically include volatilization controls. 

Some covered lagoons can also be converted into anaerobic digesters which rely upon a 

bacterial process to produce methane gas while decomposing organic wastes. The methane 

generated from the anaerobic digestion can be burned in an engine generator to produce 

electricity or in a boiler to produce heat. Digesting manure may reduce odor emission, fly 

production, and may help control some pathogens. CAFOs should be cautioned that digesters 

still require effluent holding. 

Expanding CAFOs in particular may wish to install a constant volume treatment cell in 

lieu of expanding the existing lagoon. The old lagoon may then be used as the effluent holding 

cell. As detailed in the ASAE Standard EP403.3 Design of Anaerobic Lagoons for Animal Waste 

Management, CAFOs may use multiple cell lagoons when allowed by local conditions and/or 

regulations. When operated in a series, the volume of the primary cell should be at least equal 

to the sum of the treatment volume and sludge accumulation volume. When operated in 

parallel, each cell’s volume should be designed based on the anticipated loadings. 

2-26€
Chapter 2: Requirements for the Production Area 

EPA’s AgStar Program is a voluntary effort jointly sponsored by EPA, USDA, and the 

U.S. Department of Energy that encourages the use of methane recovery (biogas) technologies 

at CAFOs that manage manure as liquids or slurries. EPA’s AgStar web site 

<www.epa.gov/agstar> provides information on anaerobic digestion systems and concepts; a 

directory identifying appropriate consultants, project developers, energy services, equipment 

manufacturers and distributors, and commodity organizations; a handbook and software to 

provide guidance on developing biogas technology at commercial farms; link to USDA 

standards; and other reports on anaerobic digestion. 

Some CAFOs have had success using impermeable covers for odor control and to 

reduce volatilization. Synthetic impermeable covers include rigid materials (e.g., wood, 

concrete, fiberglass) or flexible materials (e.g., plastic). CAFOs typically use a floating cover 

(other types include inflated covers, which are susceptible to high winds, and covers suspended 

by cables). In addition to synthetic impermeable covers, CAFOs may choose to install 

biocovers (e.g., straw, cornstalks) or synthetic permeable covers (e.g., geotextile covers for 

earthen storage, clay ball covers (Leka rock) for concrete storage). When planning the addition 

of covers, CAFOs should plan for additional maintenance activities, such as removal of excess 

biocover materials to prevent line plugging and access to the lagoon for pumpout. CAFOs 

should be cautioned that such controls may be beneficial overall, but will not necessarily reduce 

potential for overflows. 

3. Additional References 

A reference CAFOs and permit writers may use in determining whether a facility has 

adequate storage is EPA’s Cost Methodology for the Final Revisions to the National Pollutant 

Discharge System Regulation and the Effluent Guidelines for CAFOs (December 2002)(EPA821-R-03-004) available at< http://epa.gov/guide/cafo/ >. 

2-27€
CHAPTER 3: PREPARING FOR LAND APPLICATION OF MANURE, LITTER, OR

WASTEWATER ..................................................... 3-1

A. Manure Sampling .............................................. 3-1

B. Records ...................................................... 3-3

C. Additional Voluntary Controls ..................................... 3-3
Chapter 3: Preparing for Land Application 

CHAPTER 3: PREPARING FOR LAND APPLICATION OF MANURE, LITTER, OR

WASTEWATER

As a practical matter, nearly all

manure, litter, and process wastewater is land

applied. Manure may be treated or processed

into “value-added” products to make manure

more transportable, uniform, or sellable, but it

is still ultimately land applied. Land applied

manure can either be applied to a CAFO land

application site, or transferred off site to other

persons for application to the land. Chapter 4

of this manual describes the requirements for

land application of manure to CAFO land

application areas. In the case where the 

manure, litter, or process wastewater is

transferred to others, the CAFO must provide

the recipient of the manure, litter, or process

Manure Transfers 

§122.42(e)(3) Prior to transferring manure,

litter, or process wastewater to other persons,

Large CAFOs must provide the recipient of the

manure, litter or process wastewater with the

most current nutrient analysis. The analysis

provided must be consistent with the

requirements of 40 CFR Part 412. Large

CAFOs must retain for five years records of the 

date, recipient name and address, and

approximate amount of manure, litter or process

wastewater transferred to another person. 

wastewater with the results of the most current nutrient analysis (i.e., nitrogen and phosphorus)

of the material. In addition, CAFOs must document manure transfers with certain records (see

Section B below). 

A. Manure Sampling 

Knowing the nutrient content of the

material provides the CAFO and/or recipient of

manure transferred off site with the necessary

information to calculate an appropriate

application rate for the manure, litter, or 

process wastewater. Without the nutrient 

content, including various forms of the

nutrients in the manure, an accurate 

application rate cannot be calculated. Under 

the requirements of the effluent guideline,

CAFOs must sample manure at least once

annually for nitrogen and phosphorus content

Manure and Soil Sampling 

§412.4(c)(3) Manure must be analyzed a

minium of once annually for nitrogen and

phosphorus content, and soil analyzed a

minimum of once every five years for

phosphorus content. The results of these 

analyses are to be used in determining

application rates for manure, litter, and other 

process wastewater. 

(40 CFR 412.4(c)(3)). Annual nutrient sampling of manure is the minimum frequency on which

to base application rates. Many states require sampling more frequently than the minimum

annual frequency established by the CAFO rules. Soil factors are also used to determine 

appropriate application rates; these are addressed in Chapter 4 of this document. 

The CAFO rules do not establish sampling methods and protocols. Soil testing

procedures are best suited for particular soil types and climates, and many alternative soil

testing methodologies may be used to generate useful predictions of crop response. There are 

also many different ways to express test results. Analytical results may also vary by testing

procedure, and various testing procedures may not be compatible. Analytical results are best

correlated to local growing conditions. The currently used protocols and sampling methods vary

considerably by geography and climate, and the most appropriate protocols for a given locale

are recommended by the local Land Grant University and Extension Offices. CAFOs should 

use the protocols for the sampling and analysis of manure as established in their state; see

Example 3-1. 

3-1
Chapter 3: Preparing for Land Application 

Example 3-1: Example State Protocols for Laboratory Analysis of Phosphorus 

If the soil pH using water pH test is 7.5 or greater, use the Olsen P-test. If the soil pH is less than 7.5,

use the Mehlich 3 or Bray P-test. 

When taking representative manure

samples, CAFOs should be cautioned that the

appropriate sampling and analytical methods

may vary by storage system. Sampling the

manure as close to the time of application as

practical provides the CAFO with a better

measure of the nitrogen content of the 

manure. The most current manure nutrient 

analysis must be provided to the recipient of

the manure transferred off site. Under 40 

CFR 412.4(c)(3), the results of the manure

nutrient analyses are to be used in

determining land application rates. EPA 

interprets this to mean that CAFOs applying

manure to their land application areas must

show that application rates are based on the

most current manure nutrient analysis (see

40 CFR 412.4(c)(3)); see Chapter 4 of this

manual. 

The nutrient composition of manure

varies widely among farms because of

differences in animal species and

management, and manure handling and

storage practices. Sampling the manure as

close to the time of application as practical

provides the CAFO with a better measure of

the nutrient content (especially nitrogen) of

the manure. The only method available for

determining the actual nutrient content of

manure for a particular operation is

laboratory analysis. The rules do not allow 

CAFOs to use text book values in place of

annual manure sampling. 

Part of the information CAFOs must 

provide to the recipient should include the

amount of nitrogen (i.e., total kjedahl nitrogen

(TKN) and ammonia) and phosphorus (i.e.,

total phosphorus and soluble phosphorus) in

the manure based on the most recent 

sampling. 

EPA recommends CAFOs also 

Commonly Used Testing Protocols for

Phosphorus 

The Mehlich 1, Mehlich 3, Morgan, and Modified

Morgan extractants are predominant for soil tests

for phosphorus and the cations in the

Northeastern United States. They were designed

to dissolve and/or desorb some fraction of the

labile P and thus provide an index of the

availability of phosphorus to crops over the

growing season. Since the chemistry of

northeastern soils primarily involves factors

affecting the availability of aluminum phosphates,

soil tests in the Northeast use a dilute acid 

solution to dissolve these minerals and extract 

phosphorus. 

What Forms of Nutrients Should Be Tested? 

At a minimum, CAFOs should test for total 

kjedahl nitrogen (TKN), ammonia, total

phosphorus, and soluble phosphorus. 

Organic forms of nitrogen are converted to

inorganic forms of nitrogen during a process

called mineralization. The inorganic forms of

nitrogen are utilized by plants. Inorganic nitrogen,

such as ammonium nitrogen (NH4+), is usually

attached to soil particles until used by the plants.

In contrast, the nitrate form(NO3-) is highly

susceptible to leaching, and can leach before

used by the plant. 

Adsorbed phosphorus is considered unavailable

for plant growth. Erosion and runoff are common 

ways in which adsorbed phosphorus can

transport off site and contaminate surface water.

In contrast, highly permeable soils, low pH, and

low organic matter allow phosphorus to leach. 

provide the percent solids of the manure.

Percent solids is used to calculate the dry weight basis of the nutrients and solids in the 

manure. For example, if a crop requires 10 pounds of nitrogen per acre, to determine how

much manure is needed per acre to satisfy the needs of the crop one must calculate the dry

weight of nitrogen in the manure; see Example 3-2. 

3-2
Chapter 3: Preparing for Land Application 

Example 3-2: Calculating the Dry Weight of Nitrogen in Manure 

The CAFOs most recent manure sample analysis indicates that the nitrogen content in lb/ton wet

weight is 3.3 and the moisture content is 33 percent. To calculate the amount of nitrogen in lb/ton dry

weight the CAFO uses the following equation: 

Concentration N dry basis = Concentration N wet basis × (100 G % moisture content) 

= 3.3 lb/ton × (100 G 33%) 

= 2.2 lb/ton 

B. Records 

CAFOs must record specific information when manure, litter, or process wastewater is

transferred to other persons for land application. The information that must be recorded 

includes: 

C Date of the transfer; 

C The recipient’s name and address; and 

C Approximate amounts/volume of manure, litter, or process wastewater

transferred to the recipient in either tons or gallons. 

CAFOs must retain these records for a period of five years after the date of transfer.

ANSI’s manure utilization standard also recommends that operators execute written manure

transfer agreements with all individuals who accept manure for off-site use, outside their control;

see example 3-3. 

Example 3-3: Sample Manure Utilization Standard 

ANSI GELPP 0004-2002, Manure Utilization standard recommends that the operator sample and

analyze all manure that is managed outside his control. ANSI recommends that sampling be

representative of the manure being removed from the production area and if representative sampling is

not conducted for each removal of manure, sufficient historical sample data must exist to show that the

manure’s nutrient and percent total solids content does not vary enough to impact nutrient application

planning. At a minimum, ANSI recommends that manure being transferred off site be analyzed for

percent total solids, nitrogen content (TKN and ammonia nitrogen), and total phosphorus content. 

C. Additional Voluntary Controls 

EPA encourages all manure applications by non-CAFOs, including manure land applied

off site, to be conducted in accordance with a Nutrient Management Plan such as the type of

plan outlined in USDA’s Comprehensive Nutrient Management Plan (CNMP). CNMPs are 

developed in accordance with NRCS conservation planning policy and rely on the planning

process and established conservation practice standards. For more information on USDA’s 

CNMP Technical Guidance see: http://www.nrcs.usda.gov/programs/afo/

cnmp_guide_600.50.html. 

For more general information and updates on CNMP planning, see

http://www.cnmpwatch.com/. 

3-3
CHAPTER 4: OPERATION, MAINTENANCE, AND RECORDKEEPING REQUIREMENTS FOR

THE LAND APPLICATION AREA ........................................ 4-1

A. Testing Protocols for Manure, Litter, and Soil ........................ 4-1

1. Collecting Manure for Land Application ....................... 4-2

2. Manure Sampling and Testing .............................. 4-3

3. Soil Sampling and Testing ................................. 4-3

B. Protocols to Land Apply Manure ................................... 4-5

1. Nutrient Management Plan ................................. 4-6

2. Required Nutrient Management Plan Format ................... 4-7

3. Plan Certification ......................................... 4-7

4. Comprehensive Nutrient Management Plans ................... 4-7

5. Crop Rotations and Crop Nutrient Requirements ................ 4-8

6. Application Rate ......................................... 4-8

7. Application Method ...................................... 4-12

8. Application Timing ....................................... 4-15

9. Equipment Calibration and Inspection ....................... 4-17

10. Additional Land Application Considerations ................... 4-18

11. NMP Review and Revision ................................ 4-18

C. Records ..................................................... 4-19

D. Site-Specific Conservation Practices .............................. 4-19

1. Required Setback or Buffer ................................ 4-20

2. Alternatives to Setbacks .................................. 4-20

E. Voluntary Conservation and Pollution Prevention Practices ............. 4-22

1. Feeding Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23

2. Water Conservation ..................................... 4-23
Chapter 4: Requirements for the Land Application Area 

CHAPTER 4: OPERATION, MAINTENANCE, AND RECORDKEEPING REQUIREMENTS

FOR THE LAND APPLICATION AREA 

The requirements discussed in this chapter apply when manure, litter, or process

wastewater is applied to the land application area. A land application area is the land under the 

CAFO owner or operator’s control, whether it is owned, rented or leased, to which manure, litter,

or process wastewater from the production area is or may be applied (40 CFR 122.23(b)(3) and

412.2(e)). Operational control of land includes ownership, rental agreements, leases, and 

access agreements. This may also include situations where a farmer releases control over the

land application area and the CAFO determines when and how much manure is applied to fields

not otherwise owned, rented, or leased by the CAFO to another entity. 

CAFOs must develop and implement a Nutrient Management Plan to help manage

manure, including setting forth a plan for land application. Requirements for developing and

implementing a Nutrient Management Plan can be found in 40 CFR 122.42 and 412.4. Among

these are the requirements to address the form, source, amount, timing, and method of

application of nutrients on each filed to achieve realistic production goals, while minimizing

nitrogen and phosphorus movement to surface waters. Furthermore, CAFOs should routinely

re-evaluate the environmental impacts of the land application of nutrients from animal manure,

wastes, commercial fertilizers, biosolids, and any other nutrient sources. 

EPA recommends all AFOs (including Large CAFOs) implement the practices discussed

in this manual for all land on which manure, litter, or process wastewater is placed to maximize

the value of manure and to minimize the potential for runoff of pollutants from the land

application area. The following activities are required by the CAFO rules for land application of

manure and are discussed in this chapter: 

C Identify testing protocols for manure, litter, process wastewater, and soil; 

C Establish protocols to land apply manure (including development and

implementation of a Nutrient Management Plan); 

C Maintain records; and 

C Identify appropriate site-specific conservation practices to control runoff. 

Section E of this chapter discusses voluntary conservation and pollution prevention strategies. 

A. Testing Protocols for Manure, Litter, and Soil 

To manage manure, litter, and process

wastewater properly, applicators must know Additional Conditions Applicable to

how much manure is produced and its Specified Categories of NPDES Permits

composition. CAFOs must also know the §122.42(e)(1)(vii) Identify protocols for composition of the soil where manure is to be appropriate testing of manure, litter, process land applied to calculate an appropriate wastewater, and soil. application rate for the manure. The rate and 

method of application should consider the soil

holding capacity, the nutrient requirements of the crops, slope of the field, nutrients available to

the crops from other sources (e.g., nutrients in the soil, nutrients from commercial fertilizer), the

physical state of the manure, litter, and process wastewater (e.g., solid, liquid, semi-solid), and

the potential for leaching and runoff of any pollutants (including nutrients). 

4-1
Chapter 4: Requirements for the Land Application Area 

1. Collecting Manure for Land Application 

Before samples can be collected that are representative of what will be land applied, and

before the CAFO can estimate the total quantity of manure nutrients to be land applied, the

CAFO should consider the complete system of manure collection in place at the production 

area. The ease of collecting all livestock and poultry waste often depends on the amount of

freedom given to the animals. If animals are allowed to move freely within a given space,

manure will be deposited randomly; animals confined to an area are more likely to defecate in

the same places. Waste collection can be automated (e.g., scrape and flush dairy barns) or

manual (e.g., removal of waste from a dry lot with a front-end loader). Some CAFOs improve

the efficiency of manure collection (i.e., decrease losses) by paving alleys and by installing

gutters and slotted floors with mechanical and hydraulic equipment. 

CAFOs should implement pollution prevention practices to keep production and

collection of unnecessary waste to a minimum. For example, many CAFOs reduce the volume

of contaminated runoff from open holding areas by restricting the size of the open holding

areas, roofing part of the holding area, and installing gutters and diversions to direct

uncontaminated water away from the holding areas. See Chapter 2.1 of this document for more

information on clean water diversions. CAFOs may also cover manure stockpiles in the feedlot

to reduce nutrient losses and reduce contaminants in runoff. CAFOs can further reduce the 

generation of waste by minimizing the amount of fresh water used to flush milking parlors and

eggwash areas, and using recycled water from a lagoon or holding basin to flush animal

housing areas. In addition, a few CAFOs have retrofit flush systems with dry manure handling

systems (such as belts, dry bedding systems, scrapers, or v-shaped pits) to significantly reduce 

the amount of water used in manure handling. This can significantly reduce the costs for

CAFOs to both haul and land apply manure. 

For unroofed confinement areas such 

as dry lots, CAFOs must have a system for

collecting and containing contaminated runoff.

CAFOs can accomplish this by using curbs at

the edge of paved lots and reception pits

where the runoff exits the lots, or by using

diversions, sediment basins, and 

underground outlets at unpaved lots. At 

unpaved beef feedlots, operators can

carefully remove manure so as not to break

the partial seal on the soil the manure has

created. This seal, though not completely

impermeable, does help reduce the

downward movement (leaching) of

contaminated water. CAFOs should routinely

add soil to earthen lots to fill in holes and to 

assist with retaining the originally designed grade of the lot. 

The amount of manure generated at a CAFO is linked directly to the number of animals

maintained. However, because the composition and concentration of manure changes as it

ages, the amount collected and applied to the land is often less than the amount initially

generated by the animals. To estimate the amount of manure, litter, and other process

wastewater that will be available for land application, CAFOs should calculate the quantity of

manure, litter, and other process wastewater stored on site and the quantity of manure, litter,

and process wastewater removed from the production area for uses other than application to

the CAFO’s land application areas. Any estimates should include all process wastewater such

as milk parlor wash water and egg wash water, if appropriate. See Appendix D for methods for

estimating the amount of animal waste in a pile, pond, or lagoon. 

4-2
Chapter 4: Requirements for the Land Application Area 

2. Manure Sampling and Testing 

The CAFO rules require that samples of manure be collected and analyzed for nitrogen

and phosphorus a minimum of once per year (412.4(c)(3)). Because the nutrient content of 

manure may vary throughout the year and depends on many site-specific factors (e.g.,

composition of feed ration, number of different rations, type and amount of bedding, amount of

water added or lost), results of representative annual nutrient sampling helps the CAFO develop

the appropriate rate at which to land apply manure. Although the CAFO rules require that

manure be analyzed only for nitrogen and phosphorus, CAFOs should consider analyzing the

manure for percentage of dry matter, ammonium nitrogen, calcium, manganese, magnesium,

sulfur, zinc, copper, pH, and electrical conductivity (a common measurement of total dissolved

salts) to better assess the resource value of the manure. CAFOs can also conduct additional 

analyses on pathogen levels. CAFOs should check with their permitting authority for the list of

analyses to be conducted and with their state and local Cooperative Extension Offices for

acceptable procedures and sources of analysis. 

Note that a CAFO should collect samples from all manure storage areas, both

liquid and dry, as well as any wastewater or storm water storage areas, in order to obtain 

representative test results. 

To develop better estimates of the

nutrient content of manure, ideally CAFOs

should sample manure each time it is removed

from the production area. Collect samples as

close to the time of land application as

possible, leaving sufficient time between

sampling and land application to obtain and

interpret the results of the analyses. If bedding

is provided for the animals, CAFOs should

include both spent bedding and manure in the

representative samples. CAFOs should 

sample each form of animal waste stored on

site (e.g., stockpiled solids, separated solids,

lagoon or pond liquid, lagoon or pond sludge)

not only because the composition of each will

be different, but because they often are

applied to the land separately from each other. Photo by USDA NRCS 

For example, liquids from a holding pond may be irrigated weekly to a neighboring field,

whereas the solids may be land applied just once or twice per year to remotely located fields.

See Appendix E for a description and examples of commonly used sampling procedures for

solid waste, semi-solid waste, liquid waste, and poultry litter. 

3. Soil Sampling and Testing 

Soil testing is an important tool for

estimating nutrients available for uptake by a 

crop. A soil test is a laboratory procedure

that measures the plant-available portion of

soil nutrients. This measurement is used to 

predict the amount of nutrients that will be

available during the growing season. In a 

traditional soil test, analyses are conducted

for pH, nitrogen, phosphorus, potassium, soil

organic matter, and electrical conductivity.

The CAFO rules require that soil be analyzed

for phosphorus at least once every five years.

When conducting soil sampling, a 

Soil Sampling 

ANSI GELPP 004-2002, Manure Utilization, 

standard recommends sampling soils every three

years and analyzing them for, at minimum, nitrate

content, available phosphorus content, pH, and

buffer pH. 

EPA also recommends periodically analyzing the

soil sample for nitrogen, potassium, pH, salinity,

metals, micronutrients, and organic matte to

better assess the soil conditions at a land 

application site. 

4-3
Chapter 4: Requirements for the Land Application Area 

representative soil sample should be collected at each land application site and analyzed. 

Generally, the soil test report contains

the laboratory test results and fertilizer and liming

recommendations for the next two crops in

the rotation. The report also includes

information regarding the recommended time

and method of fertilizer and lime applications.

In certain parts of the country, the pre-plant

nitrate test and pre-side-dress nitrate test are

used to determine whether additional 

nitrogen is necessary after the crop begins

growing. 

CAFOs should sample each field

management unit where manure is applied.

Different field areas may have different soil

Pre-Sidedress Soil Nitrate Test (PSNT) 

The PSNT is a widely used tool for optimizing

nitrogen fertilizer use efficiency for corn 

production. The test relies on timely

measurement of mineralized soil nitrate in the top

layer of soil just prior to corn’s period of rapid

nitrogen uptake. The PSNT is highly

recommended for corn fields where manure (and

other organic sources of nitrogen) have been

applied recently. The PSNT may be less reliable

when total nitrogen application prior to sidedress

exceeds 50 pounds nitrogen per acre. CAFOs 

should consult their local Extension Service for 

more information. 

types, past cropping histories, or different

production potentials, so each field should be

sampled and managed separately. To 

ensure a representative soil sample from

each field, CAFOs should collect several 

samples around the field at the appropriate

depth and thoroughly mix all samples; see

Example 4-1. Part of this mixed soil should 

be apportioned as a representative sample

for the entire field management unit. Next, 

samples for each field should be sent to an

accredited laboratory for analyses. An 

accredited laboratory is one that has been

accepted in one or more of the following 

programs: 

C A state-certified program; 

C The North American 

Soil P Test 

A soil sample from the site is necessary to 

assess the level of "available P" in the surface 

layer of the soil. The available P is the level

customarily given in a soil test analysis by the

Cooperative Extension Service or commercial

soil test laboratories. These ranges of soil test P

values will vary by soil test method and region.

The soil test level for "available P" does not 

ascertain the total P in the surface soil. It does 

however, give an indication of the amount of total

P that may be present because of the general

relationship between the forms of P (organic,

adsorbed, and labile P) and the solution P

available for crop uptake. 

Proficiency Testing Program

(Soil Science Society of America); or 

C Laboratories participating in other programs whose tests are accepted by the

Land Grant University in the CAFO’s state. 

Example 4-1: Soil Sampling Depths 

According to USDA-ARS publication Agricultural Phosphorus and Eutrophication, it is the surface inch 

or two in direct contact with runoff that are important when using soil testing to estimate phosphorus

loss. At the same time, phosphorus may be transported to drain tiles or ground water by leaching.

Soil samples should be collected to 2 inches when the subsurface drainage tiles are not present and

the CAFO owner or operator intends to surface apply manure without incorporation. 

Soil fertility specialists at state Land Grant Universities have conducted extensive

research to determine the most suitable extraction solutions for the local soils, to correlate soil 

tests and crop yields, and to calibrate soil tests with nutrient recommendations. These 

specialists can provide valuable information and services to ensure accurate testing. 

4-4 
Chapter 4: Requirements for the Land Application Area 

The analytical results from a soil test extraction are relatively meaningless by

themselves. Soil nutrient levels should be interpreted by the CAFO or a certified nutrient

management specialist to determine the plant-available nutrients in the soil. Most soil test 

laboratories use qualitative terms such as “low,” “medium or optimum,” and “high or very high”

to describe the results, which are related to quantities of nutrients extracted. When several 

samples are collected from the same field, the soil test results for all samples should be

compared to determine the best application rate for the manure. See Appendix F of this

manual and NRCS Practice Standard 590, Nutrient Management for information on soil 

sampling, soil testing, and soil analysis interpretations. 

B. Protocols to Land Apply Manure 

The CAFO rules require CAFOs to determine and implement site-specific nutrient

application rates that comply with the technical standards for nutrient management established

by the permitting authority. These standards must, among other things, address the form,

source, amount, timing, and method of application of nutrients on each field to achieve realistic

production goals, while minimizing phosphorus and nitrogen transport to waters of the U.S.

Chapter 6 of this manual discusses technical standards for land application. 

CAFOs should use the following

process to help ensure land application Protocols for Land Application

practices are appropriate: §122.42(e)(1)(viii) Establish protocols to land

apply manure, litter or process wastewater in C Review the latest state accordance with site specific nutrient technical standards; management practices that ensure appropriate

agricultural utilization of the nutrients in the C Conduct a field specific manure, litter or process wastewater. assessment; 

C Identify planned crop rotations and document crop nutrient requirements; 

C Calculate the appropriate nutrient (manure) application rate; 

C Use an appropriate manure application method; 

C Evaluate the timing of all animal manure applications as specified in the technical

standards; 

C Understand restrictions to manure application; and 

C Calibrate and inspect land application equipment. 

Part of the protocol to land apply manure is the preparation of a Nutrient Management

Plan. The requirements for a nutrient management plan are discussed in more detail below.

NRCS Practice Standard 590, Nutrient Management, also recommends that nutrient 

management plans be used whenever plant nutrients and soil amendments are applied to the

land, and the plan should not be limited to manure applications. 

4-5
Chapter 4: Requirements for the Land Application Area 

1. Nutrient Management Plan 

All CAFOs that apply manure, litter, or

process wastewater to a land application Additional Conditions Applicable to

area must develop and implement a Nutrient Specified Categories of NPDES Permits

Management Plan (NMP) that addresses §122.42(e)(1) At a minimum, a nutrient each land application area. For Large management plan must include best CAFOs the NMPs must address the management practices and procedures following1

: necessary to implement applicable effluent

limitations and standards. C Protocols for testing manure,

litter, process wastewater, and Best Management Practices (BMPs) for Land

soil (see Section A of this Application of Manure, Litter, and Process

chapter); Wastewater 

§412.4(c)(1) The CAFO must develop and C The land application protocol implement a nutrient management plan that consistent with the technical incorporates the requirements of paragraphs standards established by the (c)(2) through (c)(5) of this section based on a permitting authority; field-specific assessment of the potential for

nitrogen and phosphorus transport from the field C The manure, litter, or process and that addresses the form, source, amount, wastewater application rate timing, and method of application of nutrients on

calculations (see Section B.5 each field to achieve realistic production goals,

of this chapter); while minimizing nitrogen and phosphorus

movement to surface waters. 

C Calibration and inspection of

land application equipment

(see Section B.8 of this chapter); 

C Recordkeeping (see Section C of this chapter); and 

C Site-specific conservation practices (e.g., practices to control erosion less than or

equal to “T”) to control runoff of pollutants into surface water bodies (see Section

D of this chapter). 

The development of a NMP involves the assessment of manure nutrients generated on

the CAFO and the land available (owned or under operational control by the CAFO

owner/operator) to apply those nutrients at the proper application rate. By requiring CAFOs to

apply manure at the appropriate nutrient application rate, EPA expects that some commercial

fertilizer application will be replaced by manure application (for additional discussion refer to

EPA’s Development of Pollutant Loading Reductions from Revised Effluent Limitation 

Guidelines for Concentrated Animal Feeding Operations). All excess nutrients beyond the

amount needed for appropriate land application at the CAFO must be transported off site for

land application, properly used or properly disposed of. 

The NMP must address the nine minimum elements EPA has determined are needed to 

protect water quality. These minimum elements require a description of how CAFOs will

achieve each of the following (also see Chapter 2 of this document): 

C Adequate storage capacity;

C Proper management (handling and disposing) of dead animals; C Diverting clean water from the production area (clean water management); C Preventing animals from contacting waters of the U.S.;

C Proper chemical handling;

1

Some of the listed requirements apply to all CAFOs under 40 CFR 122.42 while others apply only to

Large CAFOs under the Effluent Guidelines at 40 CFR 412.4. 

4-6
Chapter 4: Requirements for the Land Application Area 

C Implementing conservation practices to control nutrient loss; C Testing manure, litter, process wastewater, and soil; C Methods for the land application of manure, litter, and process wastewater; and 

C Keeping records. 

EPA’s Producers’ Compliance Guide for CAFOs and the Permit Guidance provide additional

discussion of these minimum elements. In addition, see Chapter 6 for more information on

developing and using technical standards for the land application of manure, litter, and process 

wastewater. 

2. Required Nutrient Management Plan Format 

NMPs do not need to be written in a particular scheme or format. This provides flexibility

in developing a plan to meet the CAFO rule minimum measures and practices and other

requirements. If a state already requires a NMP that includes some, but not all of the minimum

elements, then only the missing elements would need to be incorporated into the existing plan.

Some states may already require NMPs that meet the requirements of this rule, therefore, some

CAFOs may not need to develop a new plan. For example, some states already require a 

Manure Management Plan (MMP). CAFOs must ensure that their MMP, NMP, CNMP, or 

equivalent plan contains all of the elements required by the CAFO regulations. 

3. Plan Certification 

The CAFO regulations encourage, but do not require, NMPs to be developed by certified

planners. However, due to the complexity of the plans and the variety of expertise that is

needed to develop a sound NMP, EPA expects that CAFO owners/operators will seek technical 

advice from local NRCS, Cooperative Extension, and Land Grant University staff as well as 

private technical planners. These certified specialists are available nationwide to help CAFOs

prepare NMPs. Generally, nutrient management specialists must complete a precertification

training course, pass an examination, and receive continuing education on a variety of topics.

To earn certification, nutrient management planners have competence in or an understanding of

soil science and soil fertility, nutrient application and management, crop production, soil and

manure testing and result interpretation, fertilizer materials and their characteristics, best

management practices for use of nutrients and water management, environmental and

economic impacts associated with improper nutrient management, and all applicable laws and

regulations. 

4. Comprehensive Nutrient Management Plans 

EPA encourages all CAFOs to go Accredited NMP Organizations beyond the minimum regulatory requirement

to develop a nutrient management plan and Approved organizations for certifying nutrient to develop a full-fledged Comprehensive management specialists include: Nutrient Management Plan. Whether a C USDA; CAFO develops a CNMP or not, EPA C Certified Crop Advisor Program of the recommends that CAFOs and their Amercian Society of Agronomy; consultants use USDA’s CNMP Guidance to C Land Grant University Certification Programs;

assist in developing the NMP. However, it C National Alliance of Independent Crop

should be noted that following this CNMP Consultants; 

Guidance does not guarantee that a CAFO’s C State Certification Programs; and

C American Registry of Professional Animal CNMP will adequately address all of the Scientists. minimum elements that are required by the

regulations for a nutrient management plan.

Each CAFO that develops a CNMP as a way

to meet their regulatory requirement for a nutrient management plan is responsible for ensuring

that its CNMP has all of the required minimum elements for a nutrient management plan. 

4-7
Chapter 4: Requirements for the Land Application Area 

5. Crop Rotations and Crop Nutrient Requirements 

To develop appropriate land

application practices, CAFOs should identify

planned crop rotations. A rotation is the 

growing of a sequence of crops to optimize

yield and crop quality, minimize the cost of

production, and maintain or improve soil

productivity. CAFOs should describe their 

planned sequence of crops (e.g., corn for

silage, soybeans), preferably for 5 years.

This should include planting and harvesting

dates and residue management practices.

When developing NMPs, CAFOs should start

with last year’s crop and project the crop

Benefits of Crop Rotations 

A cropping sequence with a variety of crop types

(grasses, legumes) and rooting characteristics

(shallow roots, deep roots, tap roots) better uses

available soil nutrients. Following a shallowrooted crop with a deep-rooted crop helps

scavenge nutrients that might have moved below

the root zone of the first crop. 

Source: CORE4 Conservation Practices, August 1999 

rotation for the next four years. Crop rotation is important in calculating total nutrient needs over

the period of the rotation, nutrient buildup, and nutrient removal via harvesting. 

After identifying crop rotation, CAFOs

should determine and document the crops’

nutrient requirements (i.e., nitrogen,

phosphorus, and potassium) and include a

description of the expected crop yield. Plant 

growth can require more than 20 chemical

elements; 16 of these elements are 

considered essential for plant growth. The 

primary essential elements include nitrogen,

phosphorus, and potassium. Nutrient 

requirements of specific crops are readily

available from state and local Cooperative

Extension Offices. 

Sixteen Essential Elements for Plant Growth 

Carbon Iron 

Hydrogen Manganese

Oxygen Boron 

Nitrogen Molybdenum

Phosphorus Copper

Potassium Zinc 

Calcium Chlorine 

Magnesium Sulfur 

Source: Chesapeake Bay Region Nutrient

Management Training Manual 

The total nutrient requirements for

fields are largely based on the CAFO’s expected crop yields. Generally, the higher the yield

expectation, the higher the nutrient requirement. Methods for calculating expected yield goals

include using past crop yields for that field, county yield records, soil productivity tables, or local

research. Expected yields should be based on realistic soil, climate, and management 

parameters. An unrealistic estimate can result in either too many or too few nutrients being

applied. Because climate can significantly affect yields, CAFOs should base expectations on 

data from at least the last 5 years. Given a 

crop rotation, Cooperative Extension Offices

and/or soil laboratories can and often do

provide recommended quantities of

nutrients/amendments to meet the expected

yield. This recommendation usually takes

the current soil test for that field into 

consideration, and may be used as the

calculated crop nutrient requirements for that 

year. 

6. Application Rate 

The effluent guidelines require that

application rates for manure, litter, and other

process wastewater must minimize P and N

transport from the field to waters of the U.S.

in compliance with technical standards for

nutrient management established by the 

Phosphorus Index 

The ranking of a Phosphorus Index (PI) identifies

sites where the risk of phosphorus movement

may be relatively higher than that of other sites.

When the parameters of the index are analyzed,

it will become apparent that an individual

parameter or parameters may be influencing the

index disproportionately. These identified

parameters can be the basis for planning

corrective soil and water conservation practices

and management techniques. If successful in

reducing the movement of phosphorus, the

concern of phosphorus enrichment will also be

reduced. The PI provides a method for

developing management guidelines for

phosphorus at the site to lessen their impact on

water quality. See Appendix H for more details. 

4-8
Chapter 4: Requirements for the Land Application Area 

permitting authority (40 CFR 412.4(c)(2)). Under these regulations, the State’s technical

standards must include a field-specific assessment that in general will provide information

needed to determine whether land application of manure is appropriate for a site and the basis

(e.g. nitrogen or phosphorus) for the application rate. EPA anticipates that most states will use

the results from the Phosphorus Index to determine whether animal waste should be applied on

a nitrogen or phosphorus basis. See Chapter 3 of the Permit Guidance for more information on 

technical standards for nutrient management. See Chapter 6 of this document for example

technical standards and their use in developing a NMP. 

Nitrogen-based application rates are generally based on the following factors: (1) the

nitrogen requirement of the crop to be grown based on the operation’s soil type and crop; and

(2) realistic crop yields that reflect the yields obtained for the given field in prior years or, if not

available, from fields obtained for the same crop at nearby farms or county records. Once the 

nitrogen requirement for the crop is established, the manure application rate is generally

determined by subtracting any other sources of nitrogen available to the crop from the crop’s 

nitrogen requirement. These other sources of nitrogen can include residual nitrogen in the soil,

nitrogen credits from legumes, crop residues, irrigation water, and biosolids. Application rates

are based on the nitrogen content in the manure and should also account for application

methods, such as incorporation, and other site-specific practices. Phosphorus-based

application rates generally take into account the phosphorus requirements of the crop, as well

as the amount of phosphorus that will be removed from the field when the crop is harvested. 

The current NRCS Nutrient Management technical standard describes three fieldspecific risk assessment methods to determine whether the land application rate is to be based

on nitrogen or phosphorus, or whether land application is to be avoided. These three methods 

are: (1) Phosphorus Index; (2) Soil Phosphorus Threshold Level; and (3) Soil Test Phosphorus

Level. The permitting authority has the discretion to determine which of these methods, or other

State-approved alternative method, is to be used. EPA anticipates that State standards will

generally provide CAFOs the flexibility to determine, separately for each field, whether manure

is to be applied at the nitrogen- or the phosphorus-based rate. Thus, EPA expects that as the

requirements are implemented, some CAFOs will be able to apply manure at the nitrogen-based

rate for all of their fields; some CAFOs will be limited to the phosphorus-based rate on all of

their fields; and the remaining CAFOs will have some fields that are limited to the phosphorusbased rate and some fields where manure can be applied at the nitrogen-based rate. In making

these field-specific determinations, CAFOs must use the method authorized by the permitting

authority. 

The objective of determining an application rate is to match, as closely as possible, the

amount of available nutrients in animal manure with the amount required by the crop. The basic 

equation for calculating agronomic application rates for manure is: 

Agronomic application rate = Crop nutrient requirement ! nutrient credits 

Crop nutrient requirement = Crop nutrient uptake × crop yield 

Nitrogen credits = Legume nitrogen credits + nitrogen residual from

past manure applications + nutrients from

commercial fertilizer applications + irrigation water

nitrate nitrogen + crop residues + other nitrogen

credits 

Essentially, nutrient credits are all other nutrients available to the crop in addition to the

nutrients in the manure. Each of these credits is described further below. 

C Credits from previous legume crops. Atmospheric nitrogen is fixed by legume

plants and brought into the soil. Amounts of nitrogen added by legume

production vary by plant species and growing conditions. CAFOs should check 

4-9
Chapter 4: Requirements for the Land Application Area 

with their local Cooperative Extension Office or Land Grant University to

determine appropriate legume credits for crop rotations. 

C Residuals from past manure applications. Nitrogen is a mobile nutrient that

occurs in the soil and plants in many forms. Not all nitrogen in manure that

CAFOs apply is available to the crop during the year of application. Some of the 

nutrients require organic material decomposition before they are made available

for plants. A percentage of last year’s nitrogen and a smaller percentage of

previous year’s nitrogen will become plant-available during the current crop 

season. For example, 12 percent of organic nitrogen might be available from

one year ago, 5 percent might be available from two years ago, and 2 percent

might be available from 3 years ago. Because these values depend on type of

animal waste and local climate, CAFOs should use mineralization rates from their 

local Cooperative Extension Office to determine the amount of nitrogen available 

from previous manure application. Even though phosphorus also undergoes a

mineralization process, phosphorus and potassium are typically considered 100

percent plant-available the year of application. The phosphorus in the soil is also

reflected by the current soil test. Therefore, typically little or no residual amounts

of phosphorus and potassium are calculated. 

C Nutrients supplied by commercial fertilizer and biosolids. Pound-for-pound,

animal manure does not have the same nutrient value as commercial fertilizer, 

and commercial fertilizer can be customized and blended to meet specifications.

Farmers often supplement animal manure applications with commercial fertilizer

or biosolids. Furthermore, because animal manure contains relatively high

concentrations of phosphorus, crops generally are not supplied with enough

nitrogen when manure is applied on a phosphorus basis. Therefore, CAFOs may

need commercial nitrogen fertilizer to meet the crop’s total nitrogen requirements

when manure is applied at less than the nitrogen rate. CAFOs must include the 

nutrient contribution from these other sources in the manure application rate

calculations. 

C Irrigation water. Irrigation water, especially from shallow aquifers, contains

some nitrogen in the form of nitrate nitrogen. Also, water from runoff ponds and

storage lagoons contains nutrients. CAFOs must include these nutrient sources 

in the NMP. To calculate the amount of nitrogen applied with irrigation water,

CAFOs must conduct a nutrient analysis to determine the concentration of

nitrogen and phosphorus in the water typically reported as nitrate nitrogen and

soluble phosphorus in parts per million (ppm), or milligrams per liter (mg/l). 

The use of animal manure as a nutrient source requires careful planning because the

nutrients contained in the manure are generally not in the proportion needed by crops. While 

most animal manure has a nitrogen-phosphorus-potassium ratio from 3-2-3 to 2-1-2, crops

typically require nutrients in a ratio ranging from 3-1-2 to 8-1-3. For this reason, applying animal

manure based on one of the crops’ nutrient requirements usually creates either a nutrient

deficiency or excess for the other two nutrients. 

Most state guidelines/policies already allow animal manure applications at rates

sufficient to meet, but not exceed, the 

nitrogen needs of agronomic crops. In areas 

with relatively high soil phosphorus levels, Soil Nitrogen Leaching Index

states should recommend that animal 

manure be applied at rates sufficient to meet, Field staff, watershed planners, and land

but not exceed, the phosphorus needs of owners/operators use the Leaching Index (LI) to

assist in evaluating various land forms and agronomic crops. management practices for potential risk of

nitrogen movement to water bodes. Appendix G Excess levels of phosphorus build up provides more details. in the soil at a rate that depends on the soil 

4-10 
Chapter 4: Requirements for the Land Application Area 

type, soil test method, and excess level of phosphorus application. According to NRCS’s

CORE4 Conservation Practices Training Guide, it takes between 8 to 16 pounds of excess

phosphorus to raise the soil test level of phosphorus by 1 pound. Many states have developed

a relationship between soil test levels of phosphorus and the potential for significant phosphorus

movement to surface or groundwater. States should set threshold soil test levels of phosphorus

at which either animal waste application rates should be based on the crops’ phosphorus

requirements or management practices should be put into place to control runoff and erosion.

For very high soil test phosphorus levels, this should include a total restriction of additional

phosphorus application to the field; see examples 4-2 through 4-4 for example State regulations

setting specific limits for phosphorus applications and erosion. 

Example 4-2: Example State Restriction of Additional Phosphorus Applications 

Livestock waste must not be applied to land where the Bray P1 or Mehlich soil test for elemental

Phosphorus is greater than 300 pounds per acre for the top 7 inches of the soil profile. 

Example 4-3: Sample State Technical Standard to Minimize Transport of Insoluble Pollutants 

Based on a soil test for elemental Phosphorus, the following limitations apply: 

soil test P > 150 ppm: no manure application

soil test P > 75 ppm: manure application containing up to 2 years crop needs

soil test P < 75 ppm: nitrogen based rates 

Example 4-4: Sample State Technical Standard to Minimize Transport of Insoluble Pollutants 

Adequate erosion and runoff controls to meet soil loss tolerance level or “T” must be used to prevent

discharge of livestock waste to waters of the state. 

Phosphorus Transport Factors 

According to USDA planning guidance, the factors influencing phosphorus movement

include transport, phosphorus source, and management factors. Transport factors are the

mechanism by which phosphorus moves within the landscape, such as rainfall, irrigation,

erosion and runoff. Factors which influence the source and amount of phosphorus available to

be transported are soil content and form of phosphorus applied. Phosphorus management

factors include the method and timing of application such as application equipment and tillage

practices. 

Phosphorus movement in runoff occurs in both particulate and dissolved forms.

Particulate phosphorus is attached to mineral and organic sediment as it moves with the runoff.

Dissolved phosphorus is in the water solution. In general, particulate phosphorus is the major

portion (75-90 percent) of the phosphorus transported in runoff from cultivated land. Dissolved 

phosphorus makes up a larger portion of the total phosphorus in runoff from non-cultivated

lands such as pastures and fields with reduced tillage. In terms of their impact on

eutrophication of water bodies, particulate phosphorus becomes less available to algae and

plant uptake than dissolved phosphorus because of the chemical form it has with the mineral 

(particularly iron, aluminum, and calcium) and organic compounds. Dissolved phosphorus is

100 percent available to plants. Added together, the available portion of particulate phosphorus

and the dissolved phosphorus represents the phosphorus that promotes eutrophication of 

4-11
Chapter 4: Requirements for the Land Application Area 

surface waters. The interaction between the particulate and dissolved phosphorus in the runoff

is very dynamic and the mechanism of transport is complex. 

Multi-Year Phosphorus Application Rate 

In some situations, the application equipment may not be able to apply manure at the

recommended phosphorus application rate because that rate is lower than the spreading

capability of the equipment. Therefore, when permissible under the State’s technical standards,

CAFOs may elect to use a multi-year phosphorus application rate until the equipment is

replaced. In other cases, the risk of runoff is low and it may be more practical and economical

to “bank” phosphorus by applying manure at rates higher than the crop’s phosphorus needs for

that year, again, where appropriate under the State standards. In both examples, the multi-year 

phosphorus application rate consists of applying a single application of manure at a rate equal

to the recommended phosphorus application rate or estimated phosphorus removal in

harvested plant biomass for the crop rotation for multiple years in the crop sequence. These 

applications may provide the phosphorus needed for multiple years. In this situation, CAFOs 

must not apply additional phosphorus to these fields until the amount applied in the single year

had been removed through plant uptake and harvest. However, even under the multi-year

application rate for phosphorus, CAFOs cannot exceed the annual nitrogen rate for the year of

application. State standards generally will not allow this method at land application areas with a

high potential for phosphorus runoff to surface water. CAFOs should check with their permitting

authority to determine the appropriateness of using a multi-year phosphorus application rate. 

Application Rates Based on Other Parameters 

In some areas, animal waste application rates might need to be based on parameters

other than nutrients. For example, trace metals present in animal wastes, when applied at

either nitrogen- or phosphorus-based rates, are made available to plants in sufficient quantities

that they provide many of the micronutrients necessary for plant growth. Excessively high levels

of these trace metals, however, can inhibit plant growth. By limiting manure applications to the

nitrogen- or phosphorus-based rate, CAFOs will also be limiting the rate at which metals are

applied to fields and thus reduce the potential for applying excessive amounts of the trace

metals. In other regions of the country where farmlands are overloaded with salt, the salt

content of animal waste, often measured as electrical conductivity, might be the appropriate

parameter for limiting land application rates. When using any of these alternative application

rates, CAFOs must ensure appropriate agricultural utilization of the nutrients in the manure as

discussed above (see 40 CFR 122.42(e)) and 412.4(c)]. In no case may manure be applied at

rates greater than the annual nitrogen needs of the crop(s). See Appendix I for information on

calculating nutrient application rates. 

7. Application Method 

CAFOs should always apply manure uniformly and at the approved application rates.

Under the effluent guidelines, CAFOs must record the date (day, month, year) and method of

each manure application (see 40 CFR

412.37(c)). Although many equipment options

exist, there are basically two general methods of

application: subsurface application and surface

application. The method of application is

generally dictated by the form of the waste (i.e.,

solid, semisolid, liquid). 

C Subsurface application. Solid, 

semisolid, and liquid waste can all

be applied using this method.

When feasible, this is the 

preferred method of manure

application. CAFOs use this 

4-12 
Chapter 4: Requirements for the Land Application Area 

method by mechanically incorporating or injecting the manure into the soil. Mechanical 

incorporation can be performed using moldboard plows, chisel plows, or heavy discs. To 

reduce nutrient losses, CAFOs should incorporate wastes applied to the land surface before it

dries, usually within two days of application. Injection requires a liquid manure spreader and

equipment to inject manure below the soil surface. To prevent nutrient losses, CAFOs should

close the openings made by the injectors following application. 

Immediately incorporating manure in the spring will increase the amount of plantavailable nitrogen by reducing ammonia loss. Incorporation in soils with low

runoff potential can help prevent the movement of nutrients and pathogens from

animal manure to surface waters. Where soil erosion is a problem, however,

tillage might result in unacceptable losses of soil and nutrients. 

Injection is likely the best method of incorporating liquid and semisolid animal

manure in reduced-till or no-till cropping systems because crop residues left on

the surface act as a mulch, and the exposed soil surface is minimal. 

C Surface application of liquid waste (irrigation). The three predominant systems

used for surface application of liquid animal wastes (irrigation) are solid sets,

center pivots, and traveling guns. Solid set systems are a series of sprinklers

generally supplied by underground pipe. Center pivot systems are generally

used in large fields and must be able to travel in a circle. Traveling guns are

high-pressure, high-output, single-nozzle systems that crawl down travel lanes in 

the field. Liquid wastes also can be surface applied with tank spreaders. 

Irrigation can save considerable amounts of time and labor when applying large

volumes of wastewater or liquid animal waste. Sometimes CAFOs may need to

dilute liquid animal wastes with fresh water for salinity or other plant

requirements, or to facilitate application via irrigation. Irrigation provides flexibility

in applying animal wastes during the growing season and has the added

advantage of supplying water during the growing season’s drier periods.

Infiltrating liquid can carry much of the easily volatilized ammonia into the soil,

although some ammonia will still be lost from the spray before it reaches the soil. 

The irrigation system should, however, be matched to the topography, cropping

program, nutrient, and water needs of the crops, as well as infiltration,

percolation rate, and water holding capacity of the soil. CAFOs should not use 

irrigation to apply animal wastes unless solids have been removed or chopped

very fine. If solids are present, the nozzles will clog and the system will not

operate properly. Irrigation also may produce aerosol sprays that can cause

odor problems. 

C Surface application of dry, solid manure. This application method is very

effective at applying dry, bulky animal wastes such as poultry litter. Box

spreaders with a chain-drag delivery to a fan or beater spreader mechanism, or 

4-13
Chapter 4: Requirements for the Land Application Area 

tank wagons equipped with splash plates typically are used for surface

applications. 

Although this is a relatively easy

method for applying animal manure

and wastes to the land, it has 

several disadvantages. First, when 

manure is applied to the surface of

the soil without incorporation, most

of the unstable, rapidly mineralized

organic nitrogen from the manure is

lost through the volatilization of

ammonia gas. Volatilization 

increases with time, temperature,

wind, and low humidity. Surface 

application without incorporation

also increases the likelihood of nutrient losses via surface runoff. Surface runoff 

losses are more likely on soils with high runoff potential, soils subject to flooding,

soils that are snow-covered or frozen (via runoff once the snow melts or soil

thaws), and soils with little or no vegetative cover. Second, aerosol sprays

produced by mixing manure and air during this type of application can carry

odors considerable distances. Third, this application method provides poor

distribution of nutrients, which can be aggravated by heavy winds. In addition, 

precision application of manure and waste, such as poultry litter, with a geared

box spreader can be difficult. 

CAFOs can reduce nutrient losses when using surface application by

implementing soil conservation practices such as contour strip cropping, crop

residue management, cover crops, diversion terraces, vegetative buffer strips,

and grass waterways. More information about conservation practices is available

from the local soil and water conservation district and USDA’s Natural Resources 

Conservation Service. 

CAFOs must record weather conditions (e.g., rainfall amounts) at the time of application

and for the 24-hour period before and after application (40 CFR 412.37(c)). 

4-14
Chapter 4: Requirements for the Land Application Area 

Irrigation Technologies 

Irrigation application systems may be

grouped under two broad system types:

gravity flow and pressurized. Gravity-flow

systems are particularly predominant in the

arid West. Many irrigation systems rely on

gravity to distribute water across the field.

Land treatments (such as soil borders and

furrows) are used to help control lateral water

movement and channel water flow down the 

field. Water losses are comparatively high

under traditional gravity-flow systems due to

percolation losses below the crop-root zone

and water runoff at the end of the field. See 

the text box at right for potential challenges

of gravity-flow irrigation in meeting the CAFO

requirements. 

Pressurized systems-including

sprinkler and low-flow irrigation systems-use

pressure to distribute water. Sprinkler system

use is highest in the Pacific Northwest,

Northern Plains, and in Eastern States. 

Center-pivot technology serves as the

foundation for many technological

innovations—such as low-pressure center

pivot, linear-move, and low-energy precision

application systems—that combine high

application efficiencies with reduced energy

and labor requirements. For more detail on 

irrigation water application technologies and a

discussion of irrigation water management,

see ARS’ Irrigation Water Management in 

Agricultural Resources and Environmental 

Indicators at http://www.ers.usda.gov/

publications/ah712/AH7124-6.PDF. 

8. Application Timing 

Timing of manure application is an

important consideration for nutrient

availability. The longer manure nutrients are

in the soil before crops take up the nutrients,

the more those nutrients, especially nitrogen,

can be lost through volatilization,

denitrification, leaching, and surface runoff.

CAFOs should consider the hydrological

cycle and hydrological sensitivity of each field

when making management decisions. 

C Spring applications. 

Applications made during this

time are best for conserving

Gravity-Flow Irrigation 

Water is conveyed to the field by means of open

ditches, above-ground pipe (including gated pipe)

or underground pipe, and released along the

upper end of the field through siphon tubes, ditch

gates, or pipe valves. Such systems are

generally designed for irrigation water, and many

CAFOs have not traditionally accounted for the

irrigated manure nutrients. Some irrigation

systems may offer nutrient management

challenges to CAFOs including: uneven nutrient

distribution, flooding and pooling, excessive

volatilization of nitrogen, excessive leaching, and

other potential difficulties in meeting technical

standards established in their state. 

Low spot where water is ponding will reduce efficiency. 

Photo by USDA 

Best Management Practices (BMPs) for Land

Application of Manure, Litter, and Process

Wastewater 

§412.4(c)(2)(i)) Include a field-specific

assessment of the potential for nitrogen and

phosphorus transport from the field to surface

waters, and address the form, source, amount, 

timing, and method of application of nutrients on

each field to achieve realistic production goals,

while minimizing nitrogen and phosphorus

movement to surface waters. 

nutrients because the threat of surface runoff and leaching diminish in late

spring. This time period also is favorable because it is just before the period of

maximum crop uptake, allowing for more efficient nutrient utilization. 

4-15
Chapter 4: Requirements for the Land Application Area 

C Summer applications. Early summer is a good time to apply manure because it

is generally the time of maximum crop uptake. One consideration is improper

manure application rates and methods can damage growing crops. Options for

applying manure in the early summer include side-dressing manure by injecting it

between crop rows, irrigating liquid manure over corn rows when the corn is 3 to

12 inches tall (taller corn stalks can suffer more leaf damage), or applying

manure to forages such as hay fields and grasses after the first and second

cuttings or to pastures with small stubble. CAFOs can also apply nutrients to

harvested stubble fields in mid- to late-summer. Nitrogen in the manure

stimulates more growth of cover crops, especially non-legume species that

require nitrogen. The cover crop takes up the nutrients and holds them in an

organic form in the plant, preventing them from leaching or being tied up in the

soil complex. These nutrients are then more available for subsequent year’s

crops when the crop residue breaks down. 

C Fall applications. Fall application of manure generally results in greater nutrient

losses than occur from spring application regardless of the application method,

but especially if the manure is not incorporated into the soil. Increased nutrient 

losses occur because mobile nutrients such as nitrogen leach out of the soil

during this period. Many of the non-leachable nutrients react with the soil to form

insoluble compounds that build soil fertility, but some are bound so tightly that

they might not be available for the next crop. In fall, manure is best applied at

low rates to fields that will be planted in winter grains or cover crops. If winter 

crops are not planted, CAFOs should apply manure to the fields containing the

most vegetation or crop residues. Sod fields to be plowed the next spring are

also acceptable, but fields where corn silage is removed and a cover crop not

planted are undesirable sites. 

C Winter applications. The greatest nutrient losses typically occur with winter

manure applications. Research indicates that winter applications increase

pollutants in runoff during spring thaw and rainfall events. Most of the seasonal 

runoff occurs during snowmelt in late winter or early spring. Manure applied in

winter generally does not have the opportunity to dry and anchor to the soil

surface or to be incorporated into the soil. CAFOs that apply manure during the

winter must do so in compliance with the State’s technical standards. Such 

protocols must account for the form of material that would be applied (e.g. liquid,

semi-solid, or dry manure). In addition, such standards should address the time 

at which the materials would be applied relative to periods when runoff may

occur, the fraction of precipitation that runs off the land in meltwater and in

response to winter rains (as affected, in part, whether soil is frozen or not), the

time it takes runoff to travel to waters of the United States (as affected by slope,

distance to waters, roughness of the land surface, and whether or not runoff is in

contact with the land surface), and other relevant factors, as appropriate. See 

Example 4-5 and Example 4-6 for sample State Technical Standards addressing

timing of manure applications, and Appendix L for example technical standards

addressing winter application of manure and waste water. Note manure, litter, 

and wastewater storage structures should include adequate capacity to store

materials that accumulate during those times when, under the technical

standards for nutrient management, land application would be prohibited. 

Example 4-5: Sample State Technical Standard for Winter Application of Manure 

CAFOs may only apply manure between November 15 and March 15 to those fields with less than 2% 

slope and not located closer than 2 miles to waters of the U.S. 

The fields must not be subject to spring flooding. The manure should be incorporated into the soil

unless a cover crop or 30% crop residue is maintained. 

4-16
Chapter 4: Requirements for the Land Application Area 

Example 4-6: Sample State Technical Standard for Application of Manure During a High

Probability of Runoff 

The owner of a dairy CAFO wants to surface apply liquid manure on a field tomorrow, October 20. 

Manure was last applied on the field in the spring and measurable rain has not fallen in the area for

seven days. The field contains Lenawee silty clay loam and 30 percent residue from the harvested 

corn crop. When last completed, tillage was done on the contour. Subsurface drainage tiles are

present in the field. The CAFO’s permit prohibits surface application of manure if the National Weather

Service forecasts a 50 or more percent chance of rainfall exceeding one inch, or less if a lesser rainfall

event is capable of producing runoff, within 24 hours of the time of the planned application. 

According to this state Technical Standard, can the CAFO owner apply manure on the field on October 

20? 

In the course of preparing his nutrient management plan, the producer previously determined that the

field has a runoff curve number of 74 under average antecedent soil moisture conditions. The 

producer made this determination after consulting Table 2-2b and Appendix A in Urban Hydrology for

Small Watersheds (USDA-NRCS 1986)(see Appendix M for these references). For the field in 

question, the producer also determined that 0.7 inches is the minimum quantity of water that is

required to produce runoff from the field under average antecedent soil moisture conditions. The 

producer made this determination after consulting column 5 in Table 10.1 of the National Engineering

Handbook, Part 630, Hydrology (USDA-NRCS 1993). On the morning of October 20, the producer

goes to the following internet address: http://www.nws.noaa.gov/mdl/forecast/graphics/MAV/. The 

producer views the map that appears after selecting the precipitation product labeled, “24H Prob.>=0.5

in.” According to the map, there is a 10 percent or less chance of 0.5 or more inches of rain in the

upcoming 24-hour period. With this information, the producer has correctly concluded manure can be

applied in this instance while remaining in compliance with his permit. 

CAFOs should check their state regulations to determine whether fall or winter land

application is allowed. 

9. Equipment Calibration and Inspection 

Operators of Large CAFOs must

periodically inspect land application equipment Inspect Land Application Equipment for

for leaks (40 CFR 412.4(c)(4)). CAFOs must Leaks

ensure land application equipment is §412.4(c)(4) The operator must periodically operating properly (see standard permit inspect equipment used for land application of conditions for operation and maintenance manure, litter, or process wastewater. discussed in Chapter 2). CAFOs should 

calibrate land application equipment before

each application to ensure that manure is delivered at the proper rate of application. Calibration 

defines the combination of settings and travel speed needed to apply animal waste at a desired 

rate. For example, spreaders can apply manure at varying rates depending on forward travel

speed, power takeoff speed, gear box settings, discharge opening, swath width, overlap

patterns, wind conditions, manure particle size, and many other parameters. There are two 

basic calibration techniques: 

C The load-area method, which involves measuring the waste amount in a loaded

spreader and then calculating the number of spreader loads required to cover a

known land area; and 

C The weight-area method, which requires weighing manure spread over a small

surface area and computing the quantity of manure applied per acre. 

The best calibration method depends on the type of spreader used. Soil-injection liquid

spreaders should be calibrated using the load-area method because soil-injected waste cannot 

4-17
Chapter 4: Requirements for the Land Application Area 

be collected. Liquid waste that is surface applied through a tank spreader is best measured by

the load-area method because of the difficulty in collecting the liquid waste. CAFOs can 

successfully use either method to measure solid and semisolid waste. NRCS Practice Standard 

590, Nutrient Management, recommends that land application equipment be calibrated to

ensure uniform distribution of material at planned rates and ANSI GELPP 0004-2002, Manure 

Utilization, recommends annual calibration of manure application equipment. See Appendix J

for more information on calibration of animal waste spreaders and irrigation equipment. 

Though the CAFO rules do not specify the frequency of the inspections, EPA

recommends inspections every time the equipment is used. This allows CAFOs to detect and 

then correct any potential problems before they cause adverse environmental impacts. 

10. Additional Land Application Considerations 

Although manure, litter, and process wastewater are valuable resources, they can also

cause extensive damage if placed in environmentally sensitive areas or applied at inappropriate 

times. To protect water quality, CAFOs must not apply manure closer than 100 feet to any

down-gradient waters of the U.S., open tile line intake structure, sinkhole, or agricultural well

head, or other conduits to waters of the U.S. (unless the CAFO qualifies for a compliance

alternative based on vegetated buffers or other alternative practices) (40 CFR 412.4(c)(5)). In 

addition, CAFOs should not apply manure in the following areas or under the following

conditions: 

C Near or in wetlands, riparian buffer areas, water sources, wells, drinking water

supplies, high slope areas, and high erosion areas; 

C Within concentrated water flow areas (vegetated or non-vegetated) such as

ditches, waterways, gullies, swales, and intermittent streams2; 

C When the hydraulic load/irrigation water exceeds the infiltration rate of the soil; 

C When crops are not being grown; 

C When the ground is frozen or snow-covered (as described in Section 8); and 

C When measurable precipitation is occurring on the day of application. 

See Section 8 for a more detailed discussion of timing. The permit authority may include these

types of requirements as technology-based standards. 

11. NMP Review and Revision 

CAFOs must keep a copy of the NMP on site (40 CFR 122.42(e)(2)). The NMP should 

be reviewed annually and revised every five years. Ideally, the NMP is re-certified every five 

years. CAFOs should review and modify NMPs, at a minimum, when the following events 

occur: 

C Change in manure nutrients produced; C Change in crop rotation;

C Change in farming operations or management systems;

C Change in technology or available data that affects land application; or C New soil test analyses with revised recommendations.

Note some of these features may be defined as waters of the U.S. If so, unpermitted discharges into

them is directly prohibited. See the Permit Guidance for further discussion. 

4-18

2
Chapter 4: Requirements for the Land Application Area 

C. Records 

The CAFO rules require CAFOs to maintain the following records for each site on which

manure, litter, or process wastewater is applied(40 CFR 412.37(c) and 122.42): 

C The Nutrient Management Plan for each site; 

C Expected yield for each crop grown on the site; 

C The date manure is applied to each site; 

C Weather conditions at the time of application and for 24 hours prior to and

following application; 

C Test methods used to collect and analyze manure, litter, process waste water,

and soil samples; 

C Results of annual nitrogen and phosphorus manure analyses; 

C Results of the phosphorus soil analysis required every five years; 

C Explanation of the basis for determining the manure application rates, as

provided in the technical standards established by the Director; 

C The calculations for the amount of total nitrogen and total phosphorus to be

applied to each field and the amount from all sources, including sources other

than manure, litter, and process wastewater; 

C The total amount of nitrogen and phosphorus actually applied to each field

including documentation of calculations for the total amount applied; 

C The method used to land apply the manure, litter or process waste water; and 

C The dates of the inspections of the land application equipment. 

Appendix C contains a sample checklist for the records that must be kept for a CAFO land

application area. 

D. Site-Specific Conservation Practices 

Although animal manure is a valuable resource, it also can cause extensive damage if

placed in environmentally sensitive areas or applied at inappropriate times. The effluent 

guidelines prohibit Large CAFOs from applying manure, litter, or process wastewaters within

100 feet of any down-gradient waters of the U.S., open tile line intake structures, sinkholes,

agricultural well heads, or other conduits to waters of the U.S. 

The rules also allow alternative ways to comply with this setback requirement as

described below: 

4-19
Chapter 4: Requirements for the Land Application Area 

1. Required Setback or Buffer 

(e.g., metals and pathogens) in manure do not reach waters of the U.S. after it is applied to the

land. CAFOs may apply commercial fertilizer in the setback zone, and may grow crops in the

setback zones, but CAFOs are encouraged to implement conservation practices in these areas.

A setback is an area where manure, 

litter, or process wastewater is not applied, but

crops continue to be grown. A setback 

reduces pollution by increasing the distance

pollutants in land-applied manure, litter, or

process wastewater have to travel to reach

surface water bodies. The CAFO rules require

that manure, litter, and process wastewater not

be applied closer than 100 feet to any downgradient surface water, open tile line intake

structure, sinkhole, agricultural well head, or

other conduit to surface waters except under

the two situations discussed below. This 

setback requirement helps ensure that

nitrogen, phosphorus, and other pollutants

2. Alternatives to Setbacks 

There are two alternatives to the 100-foot setback requirement in the rule. First, the 

CAFO may establish a 35-foot wide vegetated buffer between the land application site and

waters of the U.S. Second, the CAFO may demonstrate that the setback or the 35-foot

vegetated buffer is not necessary due to the implementation of an alternative practice. Both of 

these alternatives are described below. 

35-Foot Vegetated Buffer 

A vegetated buffer is a permanent strip of dense perennial vegetation established

parallel to the contours of and perpendicular to the dominant slope of the land application field.

NRCS standards such as Practice 393 recommend appropriate species for cover. This 

generally includes native species. If the native species includes hay or alfalfa, CAFOs may

choose such species in the vegetated buffer; however, for the area to continue to be considered

“vegetated,” CAFOs should not harvest it. The purpose of a vegetated buffer is to slow the

runoff from a land application site, enhance the filtration of the runoff, and minimize the risk of

nutrients and other pollutants leaving the land application site and reaching surface waters.

CAFOs may not grow crops in the buffer or apply manure, litter, or other process waste waters

to the buffer. NRCS standards recommend appropriate maintenance of the buffer, such as

periodic sediment removal, nutrient removal, and vegetation trimming. Vegetated buffers are

generally eligible for funding under USDA’s Conservation Reserve Program continuous sign-up.

In general, CAFOs can enroll in this program at any time and can receive incentive payments

for the installation of the buffer and annual rental payments for the duration of the 10 to 15 year 

contract. For more information on USDA’s Conservation Reserve Program see:

http://www.fsa.usda.gov/pas/publications/facts/html/crpcont03.htm 

Demonstration that the Setback is Not Necessary 

CAFOs may demonstrate that the setback is not necessary due to implementation of

alternative conservation practices or field specific conditions. Note that in the examples

provided, it is the CAFO that must ultimately make the demonstration, even if the CAFO uses 

information generated by others. The CAFO should demonstrate that the alternative 

conservation practices or field-specific conditions will provide pollutant reductions of nitrogen,

phosphorus, biochemical oxygen demand (BOD) and total suspended solids (TSS) equal to or

greater than the reductions achieved by the 100-foot setback; see Example 4-7. EPA 

anticipates that some CAFOs will select this alternative as a proactive approach to protecting 

4-20
Chapter 4: Requirements for the Land Application Area 

water quality. The regulations do not prescribe how the CAFO should make this demonstration;

however, in general, CAFOs should not be allowed to use a small setback without implementing 

some additional controls. The demonstration of pollutant reductions should at a minimum

address the runoff, leaching, and erosion of nutrients (nitrogen and phosphorus), BOD5 (five-day

biochemical oxygen demand), and solids. 

Example 4-7: Setback Compliance 

A Large CAFO has decided only a 5-foot setback is necessary because the field slope is less than 2 

percent. 

Did the CAFOs demonstrate that the setback is not necessary? 

No, this does not meet the requirements of the effluent guidelines. The CAFO has not made any

demonstration that the setback is not necessary by showing that the pollutant reductions of the site’s 

5-foot setback would equal those of a 100-foot setback. Indeed, it is highly unlikely that pollutant

reductions from a 5-foot setback could be deemed equal to reductions from a 100-foot setback without

implementation of additional practices. 

CAFOs should not assume that meeting state best management practices (BMP)

requirements or that all commonly used conservation practices (such as those discussed below)

will always meet the demonstration requirement. For example, incorporation (i.e., tilling the

manure into the soil) is a common and frequently encouraged management practice to minimize 

runoff. However, incorporating manure within 60 days before growing a crop may increase

erosion such that a field no longer meets the equivalent of the 100-foot setback requirement.

Appendix K includes a formula for calculating soil loss (erosion). CAFOs meeting current state

requirements do not necessarily meet the 100-foot setback requirements; see Example 4-8. 

Example 4-8: Incorrectly Assuming State Requirements Equals Setback 

A state has requirements that all manure be injected or incorporated within 24 hours after land

application. The CAFO injects all manure and decides no setback is necessary. 

Did the CAFOs demonstrate that the setback is not necessary? 

No, this does not meet the requirements of the effluent guildeline. The CAFO has not made any

demonstration that the setback is not necessary. CAFOs should not assume conservation practices or

best management practices already required by the state or locality are automatically equivalent to the

100-foot setback requirement. 

State-Developed Alternative Conservation Practices. In some cases, a state may 

develop a list of alternative conservation practices that, in tandem with phosphorus-based

technical standards for land application, have been evaluated and demonstrated to provide

pollutant reductions better than the 100-foot setback. CAFOs should check to see whether their 

permitting authority has collected data and information that could be used to demonstrate that

certain conservation practices provide pollutant reductions equivalent to or better than the

reductions that would be achieved by the 100-foot setback. A state may also provide CAFOs

with information or may specify suitable methods to facilitate the CAFO’s demonstration; see

Example 4-9. 

4-21
Chapter 4: Requirements for the Land Application Area 

Example 4-9: State-Developed Alternatives to Demonstrate Setback is Not Necessary 

A Land Grant University has conducted extensive research in terraces and conservation tillage on

many soil types native to the state and shown pollutant reductions better than that achieved by the 100 

foot setback. The CAFO has soils and field conditions, and uses conservation practices, that are

similar to those on which the Land Grant University has conducted the extensive research. The CAFO 

uses this information as the basis for its demonstration. 

Did the CAFOs demonstrate that the setback is not necessary? 

It is up to the permit authority to determine whether by relying on this information the CAFO has

sufficiently demonstrated the setback is not necessary. 

NRCS Conservation Plan. EPA Soil Loss Tolerance (T) encourages CAFOs to implement a

combination of NRCS recommended Soil loss tolerance (T) is the maximum amount of practices in conjunction with the NRCS soil loss in tons per acre per year, that can be Practice Standard 590, Nutrient tolerated and still permit a high level of crop Management, for a given field. NRCS follows productivity to be sustained economically and a 9-step process to develop a conservation indefinitely. See Appendix K for more details.

plan; this process is described in detail in the

USDA-NRCS National Planning Procedures

Handbook (NPPH), and may be found at: <http://policy.nrcs.usda.gov/>. An NRCS 

Conservation Plan is essentially a set of conservation practices that are designed to work in an

integrated manner to accomplish an identified level of resource treatment. The development of

a Conservation Plan includes determination of the baseline erosion and other associated 

losses, along with an evaluation of the practices that would meet the Tolerable Soil Loss “T.”

Some Conservation Plans might call for additional efforts to achieve smaller erosion losses (i.e.,

if water quality standards are not met or the maximum amount of soil loss (T) is unacceptable

for the site.) Therefore, an USDA Conservation Plan may be used to demonstrate pollutant

reductions better than the 100 foot setback; see Example 4-10. 

Example 4-10: Using a CNMP to Meet the Setback Requirements 

A CAFO voluntarily develops a USDA-prepared CNMP. The CNMP includes a conservation planning 

component. This component includes modeling of baseline and calculation of improvements resulting

from following the suggested practices. The CAFO refers to the calculations and modeling from the

conservation planning component in the CNMP to make the demonstration of improved pollutant

reductions over a 100 foot setback, and implements the conservation planning measures in lieu of the 

setback. 

Did the CAFOs demonstrate that the setback is not necessary? 

It is up to the permit authority to determine whether by relying on this information the CAFO has 

sufficiently demonstrated the setback is not necessary. EPA anticipates the Permitting Authority will 

find, in general, a certified CNMP will satisfy the requirement to demonstrate pollutant reductions better 

than the 100 foot setback. 

E. Voluntary Conservation and Pollution Prevention Practices 

Reducing the amount of runoff and eroded sediment that can reach surface water will in

turn reduce the amount of nutrients that can reach the surface water. Numerous management

practices to control runoff and soil erosion have been researched, developed, and implemented. 

Runoff and erosion control practices range from changes in agricultural land management (e.g.,

cover crops, diverse rotations, conservation tillage, contour farming, contour strip cropping) to 

4-22 
Chapter 4: Requirements for the Land Application Area 

the installation of structural devices (e.g., diversions, grade stabilization structures, grassed

waterways, terraces). In addition to the required NMP, EPA strongly encourages all CAFOs to

implement an approved USDA/NRCS conservation plan on all fields. Practices discussed in 

this section include: feeding strategies, and water conservation. 

1. Feeding Strategies 

Feeding strategies increase the efficiency with which animals use the nutrients in their

feed, which decreases the amount of nutrients excreted in their waste. Example feeding

strategies include, but are not limited to: 

C Formulating feed to meet the animal’s nutrient requirements (i.e., precision

nutrition). This results in more of the nutrients being metabolized, thereby

reducing the amount of nutrients excreted. This strategy has been successfully

used for both swine and poultry. 

C Multiphase feeding for cows and swine. This involves frequently changing the

diet composition (such as weekly) for different groups of animals (e.g., lactating

cows) to better match the changing nutritional requirements of the animal due to

age, size, weight, or productivity. 

C Reducing the particle size of the feed for swine by milling and pelleting. Note that

this may decrease total nutrient excretion, but may require different approaches

to manure handling and treatment. For example, solids separation is less

efficient with manures where animals are fed a small pellet size. 

C Use of phytase as a feed supplement for poultry and swine to help the animal

birds digest phosphorus and reduce the amount of phosphorus they excrete. 

C Using genetically modified feed for poultry and swine to make phosphorus more

available for consumption, such as high available phytate corn. 

C Reducing the dietary supplements, such as reduced phosphorus supplements

added to grains fed to dairy cattle. 

Because the manure generated when the various feeding strategies are used has lower

nutrient content, more of the material can be applied to the land. As a result, CAFOs can use 

less land to apply all of the manure and, in some cases, transport smaller amounts of the

material off-site for land application. In addition, strategies that focus on reducing the

phosphorus concentration can turn the manure into a more balanced fertilizer in terms of plant

nutrient requirements. Using these feeding strategies can result in potential cost savings in the

form of reduced feed costs and reduced hauling/disposal costs since there is less manure to be

transported for off-site land application. 

2. Water Conservation 

Water conservation is one way of

reducing the volume of wastewater that is

generated. EPA strongly encourages CAFOs

to use a variety of practices to conserve water.

These include, but are not limited to, using

advanced watering systems, recycling flush

water, and using dry scrape systems instead of

wet flush systems. 

Nipple water delivery systems reduce

the volume of wastewater generated by only 

4-23
Chapter 4: Requirements for the Land Application Area 

delivering water when the animals suck on the nipple. This reduces the spillage that occurs

typically with trough and cup water systems and also reduces the contamination of the standing 

water in those systems by the animals. CAFOs can also use pressure sensors and automatic

shutoff valves to reduce spillage in a watering system. A sensor can detect a sustained drop in

water pressure resulting from a leak or break in a water line and shut off the flow to the broken

line until it is repaired. 

CAFOs can also conserve water by recycling the wastewater generated when waste

collection gutters and alleys are flushed with water. CAFOs may need to treat the wastewater

from the flushing operation prior to being recycled to remove pollutants and make the water

acceptable for recycling. 

Another water conservation method is a dry scrape system. In a dry scrape system,

scrapers are used to push the manure through the collection gutters and alleys instead of water.

This reduces the volume of water used in manure handling, which in turn reduces the volume of

wastewater that has to be handled. Dry scrape systems are used for dry solid manure,

semisolid manure, and for slurry manure while flush systems typically are used only for 

semisolid and slurry manure. 

4-24
CHAPTER 5: VOLUNTARY PERFORMANCE STANDARDS FOR CAFOS ............. 5-1

A. Overview of the Baseline Requirements ............................. 5-1

B. Overview of the Voluntary Performance Standards Program ............. 5-2

1. Program Participation ..................................... 5-2

2. Pollutants of Concern ..................................... 5-2

3. Required Technical Analysis ................................ 5-3

4. Validation of Equivalent Pollutant Reductions ................... 5-3

5. Relationship to Existing NPDES Permits ...................... 5-4

C. Step-By-Step Requirements for Participation in the Voluntary Performance

Standards Program ............................................. 5-4

1. Determining Baseline Pollutant Discharge ..................... 5-4

2. Demonstrating That an Alternative Control Technology Achieves

Equivalent or Better Pollutant Reductions ...................... 5-6

3. Obtaining an Alternative Performance Standard ................. 5-7

4. Future Case Studies ..................................... 5-21

Tables 

5-1. Summary Description of Baseline Requirements .............................. 5-2

Figures 
Chapter 5: Voluntary Performance Standards for CAFOs 

CHAPTER 5: VOLUNTARY PERFORMANCE STANDARDS FOR CAFOS

The examples contained in this chapter are for informative purposes only. The examples assume, 

but do not guarantee, that the CAFO meets all applicable federal, state, and local requirements. 

EPA’s long-term vision for CAFOs includes continuing research and progress toward 

environmental improvement. Currently, CAFOs, USDA, land grant universities, state agencies, 

equipment vendors, and other agricultural organizations, are working to develop new 

technologies to reduce: nutrient, pathogen, and other pollutant losses to surface water; 

ammonia and other air emissions; and groundwater contamination from animal manure. In the 

future, as these technologies are developed and improved, EPA believes that they may offer 

CAFOs the potential to match or surpass the pollutant reduction achieved by complying with the 

current requirements. At that time, EPA believes that some CAFOs will voluntarily develop and 

install new technologies and management practices equal to or better than the current 

requirements described in Chapter 2 of this manual in exchange for being allowed to discharge 

the treated effluent. (For the purposes of this chapter, the current technology controls required 

under the CAFO ELG described in Chapter 2 will be referred hereafter as the "baseline" 

technology requirements.) This is why EPA has created the voluntary performance standards 

program for CAFOs. 

The voluntary superior environmental performance standards provision in 40 CFR 

412.46(d) is available to new source Large CAFOs subject to 40 CFR Part 412, Subpart D 

(swine, poultry, and veal calves). This provision provides that these CAFOs may request from 

the Director alternative NPDES permit effluent limitations based upon a demonstration by the 

CAFO that site-specific innovative technologies will achieve overall environmental performance 

across all media that is equal to or superior to the reductions achieved by the baseline 

standards as provided by 412.46(a), which contains the Subpart D, new source CAFO 

production areas stadards. This chapter does not address the voluntary superior environmental 

performance standards for new swine, poultry, and veal CAFOs. 

The remainder of this chapter presents an overview of the baseline requirements and 

the voluntary performance standards program which includes a description of who can 

participate in the program and how participation in the program will impact existing CAFO 

NPDES permits, as well as a step-by-step description of the requirements associated with 

participation in the program. 

A. Overview of the Baseline Requirements 

As described in Chapter 2, the baseline production area requirements for all existing 

beef, dairy, heifer, veal, swine, and poultry CAFOs are the same. However, baseline 

requirements vary for new operations. A summary of the requirements is presented in Table 

5-1. 

5-1
Chapter 5: Voluntary Performance Standards for CAFOs 

Table 5-1. Summary Description of Baseline Requirements 

Existing and New Large Beef, Dairy, Heifer and Existing Large Swine, Poultry and Veal CAFOs 

1. Baseline requirements prohibit the discharge of manure and process wastewaters. 

2. A CAFO may discharge when rainfall events cause an overflow from a storage structure designed,

constructed, operated and maintained to contain the following: 

C All manure, litter, and all process wastewaters including manure, wastewater, and other wastes

accumulated during the storage period as reflected by the design storage volume (see Chapter 2 

section B.1 of this document); 

C Direct precipitation from a 25-year, 24-hour rainfall event; and 

C Associated runoff from a 25-year, 24-hour rainfall event. 

B. Overview of the Voluntary Performance Standards Program 

Under the voluntary performance Program Benefits standards program, existing and new Large 

beef, heifer, and dairy CAFOs and existing CAFOs are expected to derive substantial Large swine, poultry, and veal CAFOs are benefits from participating in this program, allowed to discharge process wastewater through greater flexibility in operation, that have been treated by technologies that increased good will of neighbors, reduced the CAFO demonstrates results in equivalent odor emissions, potentially lower costs, and or better pollutant removals from the overall improved environmental stewardship. production area than would otherwise be EPA is considering other possible incentives achieved by the baseline requirements. to encourage participation in this program. Some CAFOs already achieve zero 

discharge and, in a few cases, will 

successfully demonstrate “no potential to 

discharge.” This approach focuses on waste-generating operations, plus areas that have the 

potential to produce significant volumes of contaminated runoff such as freestall barn and yard 

areas, holding areas around milking centers, and unroofed feedlots. Although these voluntary 

programs are targeted toward the CAFO’s wastewater discharges, EPA encourages operations 

electing to participate in the program to consider environmental releases holistically, including 

opportunities to lower releases to multiple environmental media. 

1. Program Participation 

All CAFOs electing to participate in the program should have a good compliance history 

(e.g., no ongoing violations of existing permit standards or history of significant noncompliance). 

In most cases, participation will result in an individual NPDES permit addressing the sitespecific nature of the alternative technology and establishing site-specific discharge limitations. 

2. Pollutants of Concern 

In general, all CAFOs applying for the voluntary performance standards program must 

design the treatment technology to achieve equal or less quantities of BOD5, total nitrogen 

(ammonia, nitrite/nitrate, and organic nitrogen), total phosphorous, and total suspended solids 

than the baseline system. EPA selected these parameters because of their high concentrations 

in manure-type waste streams and their impact on surface water quality if not treated. In 

addition, many conventional wastewater treatment technologies, in the process of treating these 

5-2
Chapter 5: Voluntary Performance Standards for CAFOs 

four selected pollutants, will result in treatment and removal of other pollutants. To qualify for 

voluntary alternative performance standards, the CAFO may also be required to remove other 

specific pollutants, such as pathogens and metals, if these pollutants are present in the waste 

stream at concentrations that may impact surface water quality, as determined appropriate by 

the permitting authority. 

3. Required Technical Analysis 

CAFOs requesting site-specific effluent limitations to be included in NPDES permits 

must submit a supporting technical analysis and any other relevant information and data that 

would support such site-specific effluent limitations. See section C of this chapter for more 

information. 

4. Validation of Equivalent Pollutant Reductions 

The CAFO must attain the limitations 

General Versus Individual NPDES and requirements of a permit based on Permits alternative technologies as of the date of 

permit coverage (40 CFR 412.31(a)(3). In A general NPDES permit is written to cover the event these alternative limits will not be 

met as of the date of permit coverage, such a category of point sources with similar

characteristics for a defined geographic as due to startup of certain wastewater area. The majority of CAFOs may treatment technologies, the permitting appropriately be covered under an NPDES authority would need to incorporate a general permit because CAFOs generally compliance schedule into an enforceable involve similar types of operations, require order that would establish milestones for 

the same kinds of effluent limitations and implementing the alternative technologies permit conditions, and discharge the same and fully meeting the permit limitations. The types of pollutants. permitting authority should consider whether 

it is appropriate to select a permit term that is Individual NPDES permits may be most less than five years to allow the permitting appropriate for CAFOs that are exceptionally authority to evaluate whether the alternative large operations, that are undergoing technologies have resulted in the permit significant expansion, that have historical limitations being met. compliance problems, and/or that have 

significant environmental concerns. If the permitting authority grants a Individual permits will generally include all of request for voluntary alternative performance the permit conditions contained in the standards, the CAFO should, at a minimum, general NPDES permit as well as some be required to take monthly effluent samples additional requirements. Additional from the treatment system to verify continued requirements could include liners and covers permit compliance. The permitting authority 

may determine the CAFO must take more for manure and wastewater storage units

and more frequent water quality monitoring. frequent samples (such as during start-up) or 

collect samples on a basis other than 

monthly (such as during all discharge events 

in the case of intermittent discharging technologies). CAFOs should be required to analyze for 

the following pollutants: BOD5, total nitrogen, total phosphorous, and suspended solids. The 

permitting authority may also require a CAFO to monitor other pollutants on a regular basis. If 

monthly pollutant discharges from the alternative treatment system are greater than specified in 

the NPDES permit, a CAFO may be subject to both state and U.S. EPA enforcement actions. 

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Chapter 5: Voluntary Performance Standards for CAFOs 

5. Relationship to Existing NPDES Permits 

EPA expects that most CAFOs will be subject to a general, rather than an individual, 

permit that requires compliance with the baseline effluent guidelines requirements. If a CAFO 

decides to pursue voluntary performance standards based on a treatment technology that 

allows a discharge, EPA expects the permit authority would require the CAFO to prepare and 

submit an application for an individual NPDES permit. The application will include general 

information about the CAFO (e.g., ownership, responsible persons, location, receiving stream), 

waste characteristics, information about the treatment system including design and operational 

parameters, and expected effluent quality from the proposed treatment system. A CAFO may 

not discharge from the alternative treatment system until the permitting authority has issued a 

NPDES permit that allows the discharge. 

C. Step-By-Step Requirements for Participation in the Voluntary Performance 

Standards Program 

The voluntary performance standards 

program has two main requirements: the Technical Analysis of Discharge 

CAFO must estimate the pollutant discharge 

associated with the baseline system, and §412.31(a)(2) ...The technical analysis of 

must demonstrate that the alternative the discharge of pollutants must include: 

treatment technology achieves an equivalent (A) All daily inputs to the storage system, 

or better reduction in the quantity of including manure, litter, all process waste 

pollutants discharged from the production waters, direct precipitation, and runoff. 

area. This section provides detailed (B) All daily outputs from the storage 

recommendations for how these showings system, including losses due to 

should be made, along with a description of evaporation, sludge removal, and the 

the information that must be submitted to the removal of waste water for use on cropland 

permitting authority to obtain alternative at the CAFO or transport off 

performance standards. site. 

(C) A calculation determining the predicted

1. Determining Baseline Pollutant median annual overflow volume based on a

25-year period of actual rainfall data 

applicable to the site.

If a CAFO decides to participate in the

Discharge 

(D) Site-specific pollutant data, including N,

voluntary performance standards program, P, BOD5, TSS, for the CAFO from 

the CAFO must conduct a technical analysis representative sampling and analysis of all 

to estimate the pollutant discharge sources of input to the storage system, or 

other appropriate pollutant data. 

(E) Predicted annual average discharge of

pollutants, expressed where appropriate as 

a mass discharge on a daily basis 

(lbs/day), and 

calculated considering paragraphs 

(a)(2)(i)(A) through (a)(2)(i)(D) of this 

section. 

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Chapter 5: Voluntary Performance Standards for CAFOs 

associated with the baseline1

 waste management system (e.g., anaerobic treatment lagoon). At 

a minimum, the technical analysis must include the information in the text box at right (see 40 

CFR 412.31(a)(2)). 

In an expected limited number of circumstances, the calculated median annual overflow 

volume based on a 25-year period of actual rainfall data may be zero. In these instances, the 

permit authority may allow the CAFO to calculate an average overflow volume for the 25-year 

period. 

One approach for estimating pollutant discharges is to use a computer simulation model, 

spreadsheet, or similar program. One can either develop a new model or revise an existing 

model that estimates pollutant discharges from waste management systems. These models 

can be used to evaluate site-specific climate and wastewater characterization data to project the 

pollutant discharge from your baseline system. The model should evaluate the daily inputs to 

the waste management system, including all manure, litter, all process wastewaters, direct 

precipitation, and runoff. The model should also evaluate the daily outputs from the waste 

management system, including losses due to evaporation, sludge removal, and the removal of 

wastewater for use on cropland at the CAFO or transported off site. CAFOs may use the model 

to predict the median annual overflow from the storage system that would occur over a 25-year 

period. Next, the CAFO should use these overflow predictions, combined with representative 

pollutant concentrations in the overflow, to predict the annual average discharge of pollutants 

(including nitrogen, phosphorus, BOD5, and total suspended solids) over the 25 years evaluated 

by the model. See 40 CFR 412.31 (a)(2)(i)(E) for the complete list. 

Site-specific information that a CAFO should gather and input to the model to calculate 

the predicted annual discharge of pollutants from the baseline system includes the following 

(also see 40 CFR 412.31(a)(2)): 

C Data on actual local precipitation from the past 25 years. Precipitation data are 

available from the National Weather Service and possibly a local airport. One 

can also obtain local precipitation data from EPA’s Better Assessment Science 

Integrating point and Nonpoint Sources (BASINS) model at: 

http://www.epa.gov/OST/BASINS/b3webwn.htm. State weather data are located 

at: http://www.epa.gov/ost/ftp/basins/wdm_data/. Historical weather may also be 

obtained from National Climate Data Center. 

C Soil type and permeability in drylot areas. Site-specific soil permeability data 

may be obtained from the local Soil Conservation District office. 

C The rate of evaporation from the storage system (e.g., lagoon, pond, holding 

tank). Evaporation rate data are available from the National Weather Service or 

EPA’s BASINS model website. 

C The concentration of BOD5, total nitrogen, total phosphorous, suspended solids, 

and other pollutants as required by the Director, measured in a representative 

sample collected from the waste management system. 

1

Recall a baseline system at the CAFO is a system that meets the requirements as described in Chapter 2 

(see 40 CFR 412.31(a)(1)). 

5-5 
Chapter 5: Voluntary Performance Standards for CAFOs 

C Starting volume in the waste management system based on process wastes and 

runoff collected since the last land application or waste management system 

pump-out and/or sludge clean-out; 

C Projected total design storage volume to store manure, wastewater, and other 

wastes accumulated during the storage period as reflected by the design storage 

volume (see Chapter 2 of this document); 

C Change in the waste management system’s volume due to the estimated daily 

flow of process wastes; 

C Change in the storage system volume due to direct precipitation and evaporation; 

C Change in the storage system volume due to runoff from open lot areas; and 

C Change in volume due to waste management system pump-out and/or sludge 

cleanout and land application. 

The model should calculate the net change in the volume of the liquid storage area daily 

and add it to the previous day’s total. If the total volume is greater than the maximum design 

volume, then the excess volume overflows. Also, CAFOs can calculate the mass pollutant 

discharge from the overflow by multiplying the overflow by the pollutant concentration (BOD5, 

total nitrogen, total phosphorous, total solids) measured in the representative sample. 

Examples 1 and 2 at this end of this chapter present the results of a technical analysis 

conducted for an example dairy and swine CAFO, representatively. Appendix P provides stepby-step example calculations showing the methodology used to predict the median annual 

overflow volumes and annual average discharge of pollutants for Examples 1 and 2. 

2. Demonstrating That an Alternative Control Technology Achieves Equivalent or 

Better Pollutant Reductions 

EPA recommends that CAFOs follow the steps shown below to demonstrate that an 

alternative control technology will achieve equivalent or better pollutant reductions: 

C Measuring volume or quantity of manure, wastewater, and runoff generation from 

production areas. 

C Collecting samples of manure, wastewater, and runoff to determine raw or 

untreated pollutant concentrations for treatment system design using the same 

pollutant parameters as measured for baseline. 

C Preparing a conceptual design of the treatment system showing equipment 

sizing, operational requirements, and expected pollutant reductions by each 

treatment step. 

C Estimating the volume and frequency of discharge from the treatment system. 

C Estimating or measuring the concentration of the effluent from the treatment 

system. 

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Chapter 5: Voluntary Performance Standards for CAFOs 

C Results of pilot testing to verify the treatment system will achieve equivalent or 

better pollutant reductions than baseline for all required constituents (including 

BOD5, total nitrogen, total phosphorous, and suspended solids), and to gather 

information for design of the full scale treatment system. Any pilot testing needs 

to be related to representative/typical production and climate conditions expected 

at the CAFO. Therefore, multiple testing episodes or sites may be necessary to 

adequately capture the actual conditions at the CAFO. Consider on-site pilot 

testing to demonstrate the proposed system will work at the CAFO. 

Examples 1 and 2 summarize the 

methods that could be used by the Can a CAFO Demonstrate Equivalency

Using Practices Already in Existence at the example CAFOs to determine if an Site? alternative treatment system performed 

equivalent or better than the baseline Yes. If the practices already in place at the system. In these examples, the permit operation provide equivalent or better pollutant authority would require the CAFO to reductions than the predicted average annual continue to collect testing data until the pollutant discharge for the baseline alternative technology has been proven at requirements, then the CAFO can apply for an the site. Thereafter, the CAFO may only alternative performance standard. Example 3 need to collect samples frequently enough shows how data from an existing pollution to demonstrate compliance with their 

NPDES permit limitations. prevention/treatment system were compared to

the baseline system to develop site-specific 

permit limits for an egg production facility. 3. Obtaining an Alternative 

Performance Standard 

The next step in participating in the voluntary performance standards program is to 

submit an application to the permitting authority along with the technical analyses, conceptual 

design, results of any pilot-scale testing and any other relevant data before construction of the 

full-scale treatment system. The permitting authority should review the application, technical 

analyses, and conceptual design, and then compare the pilot-scale testing results with the 

predicted annual average discharge of pollutants to verify the proposed treatment system is 

reasonable, appropriate, and will likely achieve the predicted results. In addition, the permit 

authority should confirm the quantity of pollutants discharged from the production area are 

equal to or less than the quantity of pollutants discharged under baseline. The Director has the 

discretion to request additional information to supplement the CAFO’s application, including 

inspection of the CAFO (40 CFR 412.31(a)(2)(E)(ii)). Once an application is approved, a CAFO 

can proceed with detailed design and construction of the alternative control technology. 

Following construction of the treatment system but prior to start-up (see 40 CFR 412.31(a)(3)), 

the CAFO must obtain an NPDES permit specifying the discharge limitations. Also see section 

B.4 of this chapter.

Example 1: Whole Milk Dairy, Lancaster, PA 

Background 

Amish Country Dairy (ACD) is a Large CAFO located in Lancaster County, PA. ACD currently milks 

1,200 dairy cows per day, plus manages 400 heifers and 400 calves. Milk cows are confined in a 

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Chapter 5: Voluntary Performance Standards for CAFOs 

Example 1: Whole Milk Dairy, Lancaster, PA 

550,000 square foot area containing 3 free-stall barns, the a milking parlor, and yard. Free-stall barn 

alleys are cleaned 3 times per day (every 8 hours) using a flush system. Sawdust is used for bedding 

in the free stall barn. Silage is kept covered. All flush water, cow wash-water, and parlor cleanup and 

sanitation water is directed to the existing 3,351,252 cubic foot manure holding lagoon. 

All liquids in the holding lagoon are applied to crop land four times each year consistent with the site’s 

NMP. Thus the lagoon has 90 days of storage capacity. To help show the storage structure has 

adequate capacity, ACD assumes that the storage volume is never less than the accumulated sludge 

volume plus the minimum treatment volume. Although solids are periodically removed and thus more 

volume is available to store process wastewater, runoff, and precipitation, this conservative assumption 

reserves the sludge volume for the maximum amount of accumulated solids over the storage period. 

Approximately 40 percent of the milk cow confinement area is paved or roofed. Precipitation from 

roofed areas drains on to the paved portion of the milk cow confinement area before being discharged 

to the manure holding lagoon. All paved areas have curbing to contain manure and precipitation. 

Unpaved areas have reception pits to collect manure and precipitation before discharge to the manure 

holding lagoon. Heifers and calves are managed on a non-paved 300,000 square foot dry lot that 

discharges to the manure holding lagoon. Any overflows from the lagoon may eventually reach a 

receiving surface water body (in this case, the Susquehanna River). 

Summary of Baseline Overflow Volume and Pollutant Loading Calculations 

Process Wastewater Generation: 25,857 ft3

/day (193,400 gal/day) 

Sludge Volume (constant): 870,807 ft3 

Minimum Treatment Volume (constant): 1,530,000 ft3 

Total Existing Storage Lagoon Volume: 3,351,252 ft3 (25 million gallons) 

Volume in Lagoon at Start: 2,400,807 ft3

 (Sludge Volume + Minimum Treatment 

Volume) 

Precipitation Volume (median): 40 in/yr 

Evaporation Rate (median): 57 in/yr 

Runoff (median): 17,033 ft3

/yr 

Liquid/Solids Removal for Crop Application: Completely dewater all lagoon liquids 4 times per year 

Calculated Baseline Overflow Volume Method: 

Daily accumulation of lagoon liquids (ft3

/day) = Process Waste (ft3/day) + Runoff (ft3/day) + 

((Precipitation - Evaporation (ft/day)) x Lagoon 

Surface Area (ft2

) 

Volume of Lagoon Liquids (ft3

) = Previous days volume (ft3) + Accumulation volume 

(ft3

/day) 

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Chapter 5: Voluntary Performance Standards for CAFOs 

Example 1: Whole Milk Dairy, Lancaster, PA 

If the Volume of Lagoon Liquids (ft3) is greater than the following: 

Existing Storage Lagoon Volume (ft3

) - Sludge Volume (ft3) - Minimum Treatment Volume (ft3)], then 

Overflow Volume = Volume of Lagoon Liquids (ft3

) - [Existing Storage 

Lagoon Volume (ft3

) - Sludge Volume (ft3) - Minimum 

Treatment Volume (ft3

)]; and 

Volume of Lagoon Liquids (ft3

) is adjusted to the following: 

[Existing Storage Lagoon Volume (ft3) - Sludge Volume (ft3) - Minimum Treatment Volume (ft3)] (the

maximum volume of liquids the lagoon can store)

If it is a land application day: 

The Volume of Lagoon Liquids (ft3

) = 0 

Model Calculated Overflow Volume for ACD: 57,386 ft3

/yr (429,247 gal/yr) 

ACD collected a representative sample of liquid from the storage lagoon to calculate the annual 

pollutant discharge of BOD5, total nitrogen, total phosphorous, and total suspended solids (TSS) as a 

result of the overflow volume. The sample was collected from the top 12 inches of the lagoon surface 

since the majority of overflow will likely be attributed to this zone. The sampling results are shown 

below: 

BOD5: 600 mg/L (5.0 lbs per 1000 gallons) 

Total nitrogen: 268 mg/L (2.2 lbs per 1000 gallons) 

Total phosphorous: 208 mg/L (1.7 lbs per 1000 gallons) 

TSS: 1,500 mg/L (12.5 lbs per 1000 gallons) 

Based on the overflow and the measured concentration, the annual pollutant discharges from the 

lagoon were calculated by multiplying the flow by the concentration as shown in the example for BOD5 

below: 

BOD5 : 600 mg/L x 3.785 L/gal x 429,247 gal/yr x 2.2 lbs/kg x 1 kg/106 mg = 2,145 lbs/yr 

A summary of the pollutant loadings based on the overflow rate and concentration is shown below. 

BOD5 2,145 lbs/yr

Total nitrogen 958 lbs/yr

Total phosphorous 743 lbs/yr

TSS 5,362 lbs/yr

Diagram of Baseline Waste Management System 

The following figure is a block diagram of ACD summarizing the inputs and outputs from the manure 

storage lagoon and the overflows and pollutant loadings. Any overflows from the lagoon eventually 

reach a surface water body (in this case, the Susquehanna River). 

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Chapter 5: Voluntary Performance Standards for CAFOs 

Example 1: Whole Milk Dairy, Lancaster, PA 

Waste Characterization and Alternative Treatment System Evaluation 

ACD in cooperation with their consultant, Tick Engineering, has decided to voluntarily pursue an 

alternative to their existing lagoon in order to have a constant discharge of treated water to the 

Susquehanna River. The treatment train they have selected consists of primary clarification, aerobic 

biological treatment and final polishing using an engineered wetland. Pilot scale testing of the system 

was conducted June 15 to November 15 at ACD by Tick Engineering using actual process wastewater. 

A summary of the conceptual design calculations and pilot scale treatment test results are included 

below. 

Waste Flow and Characterization 

A daily composite sample of manure, flush-water, wash-water, parlor cleanup and sanitation water and 

rainwater was collected by Tick Engineering during a seven day operational period in April 2003 to 

characterize the waste load discharged to the storage lagoon. The combined volume of manure, flushwater, wash-water, parlor cleanup water and rainwater was also measured during the seven day 

sampling period in April, 2003. The average daily flow to the lagoon, which included one day of rainfall 

was 176,410 gallons. Waste characterization data and calculated average daily loading to the 

treatment system is summarized below: 

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Chapter 5: Voluntary Performance Standards for CAFOs 

Example 1: Whole Milk Dairy, Lancaster, PA 

Pollutant Concentration Influent 

(mg/L) (lbs/day) 

BOD5 1,701 2,496 

Total nitrogen 478 702 

Total phosphorous 74 109 

TSS 12,269 18,018 

Daily pollutant loadings were calculated by multiplying the concentration for each constituent by the 

average daily flow as shown in the example below for BOD5: 

BOD5 Loading: 1,701 mg/L x 3.785 L/gal x 1 kg/1,000,000 mg x 2.2 lbs/kg x 176,410 gal/day = 

2,496 lbs/day 

Treatment system design is based on a flow excess of 20% or 211,690 gallons per day. Flows greater 

than 211,690 gal/day will overflow back to the existing 3,351,252 cubic foot lagoon. During dry weather 

periods, excess water and direct precipitation from the lagoon will be pumped back to the beginning of 

the treatment system for processing. The following figure is a flow diagram showing the treatment 

equipment and sizes, flows in and out of each treatment unit, and the pollutant reductions by each 

treatment step. Note that ACD will have the capability of recycling nearly 90,000 gallons per day of 

treated effluent for manure flushing. 

Alternative Treatment System Effectiveness 

The average concentration of target pollutants measured in the effluent from the pilot scale treatment 

system during the 6-month study is shown below. The calculated monthly loadings for the full-scale 

treatment system is based on an average daily flow of 176,410 gallons entering the treatment system 

minus a recycle flow of 90,000 gallons per day for manure flushing. 

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Chapter 5: Voluntary Performance Standards for CAFOs

Example 1: Whole Milk Dairy, Lancaster, PA

5-12

Diagram of Alternative Treatment System

Comparison of the Baseline Overflow to the Discharge from the Alternative Treatment System

Pollutant Baseline Overflow Treatment System Discharge

(lbs/yr) (lbs/yr)

BOD5 2,145 1,830

Total nitrogen 958 110

Total phosphorous 743 730

TSS 5,362 2,920

Conclusion: The loadings comparison clearly shows the proposed treatment system consisting of

primary clarification, aerobic biological treatment and final polishing using an engineered wetlands

would achieve a quantity of pollutants discharged from the production area that is equal to or less than

the quantity of pollutants that would be discharged using baseline treatment. Note this analysis

pertains to the technology-based requirements of the CAFO rules, and does not include an assessment

of whether such a discharge would meet the State’s water quality standards.
Chapter 5: Voluntary Performance Standards for CAFOs 

Example 2: KF Pork Producers, Dubuque, IA 

Background 

KF Pork Producers (KFP) is a Large CAFO located in Dubuque County, Iowa. KFP currently has 7,000 

grower swine with an average weight of approximately 140 pounds. Swine are housed in a 57,400 

square foot barn with 10 confinement pens. Manure is washed from pens daily using a flush system. 

All manure and flush water drains into storage tanks beneath the partially slotted concrete floor. 

Storage tanks are emptied daily by pumping the manure and flush water to an existing 3,931,800 cubic 

foot manure holding lagoon. 

KFP, in consultation with local residents, avoids de-watering the storage structure on weekends and 

holidays. Liquids in the holding lagoon are applied to crop land (to the maximum daily hydraulic 

loading) on the 7th, 14th, 21st, and 28th days of each month during the freeze free period between April 

21 and September 14, assuming that there has been no significant precipitation during the three days 

prior to the day of application. [The nutrient applications are tracked by KFP’s Nutrient Management 

Plan, and are not further considered here.] KFP assumes that the storage volume is never less than 

the accumulated sludge volume plus the minimum treatment volume. Although there are times that 

solids are removed and more space is available for process wastewater, runoff, and precipitation, this 

conservative assumption reserves storage space for the maximum amount of accumulated solids over 

the storage period. 

Summary of Baseline Overflow Volume and Pollutant Loading Calculations 

Process waste generation: 8,356 ft3

/day (62,500 gal/day) 

Sludge Volume (constant): 486,091 ft3

 (3.6 million gal) 

Minimum Treatment Volume (constant): 661,500 ft3

 (4.9 million gal) 

Total existing storage lagoon volume: 3,931,800 ft3

 (29.4 million gal) 

Volume of Liquids and Solids in Lagoon at Start: 1,206,083 ft3

 (Sludge Volume + Minimum 

Treatment Volume + Accumulated Process 

Wastes Since Last Liquid Application) 

Precipitation Volume (average): 26 in/yr 

Evaporation Rate (average): 98 in/yr 

Liquid/Solids Removal for Crop Application: Land apply lagoon liquids to the maximum 

hydraulic loading of the crop land on days 7, 

14, 21, and 28 of each month unless there 

has been precipitation in the past three days 

before the application day (This occurs 

between the freeze free days between April 

21 and September 14) 

Calculated Baseline Overflow Volume Method 

Daily accumulation of lagoon liquids (ft3

/day) = Process Waste (ft3/day) + [Precipitation - Evaporation] 

(ft/day) x Lagoon Surface Area (ft2

) 

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Chapter 5: Voluntary Performance Standards for CAFOs 

Example 2: KF Pork Producers, Dubuque, IA 

Volume of Lagoon Liquids (ft3) = Volume of Lagoon Liquids from Previous Day (ft3) + 

Daily accumulation of lagoon liquids (ft3

) 

If the Volume of Lagoon Liquids (ft3

) is greater than the following: 

Existing Storage Lagoon Volume (ft3

) - Sludge Volume (ft3) - Minimum Treatment Volume (ft3)], then 

Overflow Volume = Volume of Lagoon Liquids (ft3

) - [Existing Storage 

Lagoon Volume (ft3) - Sludge Volume (ft3) - Minimum 

Treatment Volume (ft3

)]; and 

Volume of Lagoon Liquids (ft3

) is adjusted to the following: 

[Existing Storage Lagoon Volume (ft3) - Sludge Volume (ft3) - Minimum Treatment Volume (ft3)] (the

maximum volume of liquids the lagoon can store)

If it is an application day (day 7, 14, 21, or 28 of the time period between April 21 and September 14),

the Volume of Lagoon Liquids (ft3

) = Volume of Lagoon Liquids (ft3) - Max Hydraulic Loading (ft3)

Model Calculated Overflow Volume for KFP: 158,419 ft3

/yr (1,184,970 gal/yr) 

KFP collected a representative sample of liquid from the storage lagoon to calculate the annual 

pollutant discharge of BOD5, total nitrogen, total phosphorous, and total suspended solids (TSS) as a 

result of the overflow volume. The sample was collected from the top 12 inches of the lagoon surface 

since the majority of overflow will likely be attributed to this zone. The sampling results are shown 

below: 

BOD5: 1,650 mg/L

Total nitrogen: 270 mg/L

Total phosphorus: 102 mg/L

TSS: 3,000 mg/L

Based on the overflow and the measured concentration, the annual pollutant discharges from the 

lagoon were calculated by multiplying the flow by the concentration as shown in the example for BOD5 

below: 

BOD5 : 1650 mg/L x 3.785 L/gal x 1,184,970 gal/yr x 2.2 lbs/kg x 1 kg/106

 mg = 16,280 lbs/yr 

A summary of the pollutant loadings based on the overflow rate and concentration is shown below. 

BOD5:

Total nitrogen:

Total phosphorus:

TSS:

16,280 lbs/yr 

2,660 lbs/yr 

1,010 lbs/yr 

29,600 lbs/yr 

Diagram of Baseline Waste Management System 

The following figure is a block diagram of KFP summarizing the inputs and outputs from the manure 

storage lagoon and the overflows and pollutant loadings. Any overflows from the lagoon discharge to a 

surface water body (in this case, the Mississippi River). 

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Chapter 5: Voluntary Performance Standards for CAFOs 

Example 2: KF Pork Producers, Dubuque, IA 

KFP realized it was not cost effective to haul excess nutrients in the liquid manure. KFP, in cooperation 

WB Engineering examined 

sulfide, and worked with KFP to determine if changes in swine feed rations could lower the amount of 

ammonia and phosphorous entering the manure. 

capacity and less frequent overflows. 

As a result of the whole-farm audit, KFP decided to further evaluate a new wastewater treatment 

system plus an off-gas treatment system for air removed from both the swine barn and manure pits. 

would have exceeded nutrient requirements according to the facilities NMP. 

For off-gas from the swine barn and manure 

Pilot 

scale testing of both the wastewater and air treatment system was conducted March 20 to September 

20 2003 by WB Engineering. 

treatment test results are included below. 

Waste Characterization and Treatment System Evaluation 

with their consultant WB Engineering, conducted a whole-farm audit to determine if pollutant releases 

could be reduced at the facility by application of new technologies. 

discharges of pollutants from lagoon overflows, estimated air emissions of ammonia and hydrogen 

Finally, WB examined manure application rates to 

determine if more frequent removals of manure/sludge from the lagoon could provide additional storage 

Changes in feed rations were not implemented on recommendations from both an animal nutritionist 

and the local agricultural extension agent, and additional application rates of manure to KFP’s crop land 

The treatment train selected for KFP consists of primary clarification, a vibrating membrane filtration 

system, and final polishing using a biological trickling filter. 

pits, a biofilter using an inorganic media was selected to remove ammonia and hydrogen sulfide. 

A summary of the conceptual design calculations and pilot scale 

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Chapter 5: Voluntary Performance Standards for CAFOs 

Example 2: KF Pork Producers, Dubuque, IA 

Waste Flow and Characterization 

A daily composite sample of manure and flush-water was collected by WB Engineering during a seven 

day operational period in March 2003 to characterize the waste load discharged to the storage lagoon. 

The volume of manure and flush-water was also measured during the seven day sampling period in 

April, 2003. The average daily flow to the lagoon was 62,500 gallons. Waste characterization data and 

calculated average daily loading to the treatment system for the target pollutants is summarized below: 

Pollutant Concentration Influent 

(mg/L) (lbs/day) 

BOD5 3,766 1,960 

Total nitrogen 753 392 

Total phosphorus 301 157 

TSS 11,863 6,174 

Daily pollutant loadings were calculated by multiplying the concentration for each constituent by the 

average daily flow as shown in the example below for BOD5: 

BOD5 Loading: 3,766mg/L x 3.785 L/gal x 1 kg/1,000,000 mg x 2.2 lbs/kg x 62,500 gal/day = 

1,960 lbs/day 

The wastewater treatment system design is based on a flow excess of 20% or gallons per day. Flows 

greater than 75,000 gal/day will overflow to the existing 1,500,000 cubic foot lagoon. During dry 

weather periods, excess water from the lagoon will be pumped back to the beginning of the treatment 

system for processing. Note that KF will have the capability of recycling nearly 22,600 gallons per day 

of treated effluent for manure flushing. 

Off-gas from the swine barn and deep pit areas was characterized by collecting air samples from areas 

near the exit fans. The average concentration of ammonia and hydrogen sulfide measured in the offgas was 54 ppm and 4 ppm, respectively. Based on a measured exhaust rate from all the exit fans for 

the barn and pit areas, WB engineering estimates approximately 80 lbs/day of ammonia and 

approximately 10 lbs/day of hydrogen sulfide is emitted to the atmosphere. Design of the biofilter for 

treatment of off-gas was provided by BIOREM and consisted of new fans and duct work to move air 

through a single discharge point, and an in-ground biofilter to destroy ammonia and hydrogen sulfide. 

Treatment System Effectiveness 

The average concentration of target pollutants measured in the effluent from the pilot scale wastewater 

treatment system during the 6-month study is shown in the table below. The calculated monthly 

loadings for the full-scale treatment system is based on an average daily flow of 25,250 gallons. The 

remaining 37,750 gallons of water that entered the treatment system is used for either recycle or 

contains concentrated treatment residuals that are discharged to the existing storage lagoon. KFP now 

has the additional flexibility to collect solids and concentrated nutrients from the existing sludge lagoon 

and haul them offsite for other uses. 

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Chapter 5: Voluntary Performance Standards for CAFOs

Example 2: KF Pork Producers, Dubuque, IA

5-17

Diagram of Alternative Treatment System

Comparison of the Baseline Overflow to the Discharge from the Alternative Treatment System

Pollutant Baseline Overflow Treatment System Discharge

(lbs/yr) (lbs/yr)

BOD5 16,280 3,285

Total nitrogen 2,664 2,215

Total phosphorous 1,006 1,460

TSS 29,602 2,190

The average concentration of ammonia and hydrogen sulfide measured in the off-gas from the biofilter

during the 6 month pilot scale treatment test is shown below. The biofilter removed approximately 70

percent of the ammonia and 87 percent of the hydrogen sulfide in the gas stream. The biofilter also

eliminated all odors from the swine CAFO’s offgas.

Biofilter Treatment Results During the 6-Month Pilot Test

Pollutant Influent Loading Gas Flow Effluent Loading Odor

(lbs/day) (cfm) (lbs/day)

Ammonia 80 23,000 25 None

Hydrogen Sulfide 10 23,000 1.3 None
Chapter 5: Voluntary Performance Standards for CAFOs 

Example 2: KF Pork Producers, Dubuque, IA 

Conclusion: Comparison of the pilot scale testing results with the calculated overflow discharges 

indicates the proposed treatment system can not achieve a quantity of pollutants discharged for all the 

targeted pollutants that is equal to or less than the quantity of pollutants that would be discharged under 

the baseline performance standards. Because the proposed treatment system cannot achieve this 

reduction for all target pollutants, the permitting authority denies the facility’s request for an individual 

NPDES permit for operation and discharge of water from the proposed treatment system. If 

modifications to the treatment system can be made that lower the annual discharge of phosphorous, 

then an individual permit may be considered. 

KF Pork Producers has still decided to install a new biofilter system to remove odors, ammonia and 

hydrogen sulfide from their air stream to address complaints from neighbors regarding smells from the 

facility. 

Example 3: Birvan Egg Farms, Okeechobee County, FL 

Background 

Birvan Egg Farms (Birvan) is a Large CAFO located Okeechobee County, Florida. Birvan currently has 

40,000 laying hens with an average weight of approximately 3 pounds. Birds are housed in a high-rise 

cage system. Manure drops from the cages to the floor below and is picked up by the wet flush system 

and is transferred to the anaerobic digester. The anaerobic digester removes the majority of nutrients, 

BOD5 and volatile solids while generating methane that is used in the facilities boiler system. Effluent 

from the anaerobic digester is pumped through a vibrating membrane filtration system for polishing 

residual solids, BOD5 and nutrients before land application of the polished water to a small grass field. 

All solids are hauled and sold off-site. Birvan elected to install an anaerobic treatment system rather 

than a holding pond due to space constraints and the lack of crop land to apply liquids and solids. The 

manure treatment system has been in operation since 1996. 

Birvan calculated the overflow volume and loading from a baseline system (a liquid storage structure) 

that could have been installed at the facility and compared the results with the loadings currently being 

obtained from the existing treatment system. 

Summary of Baseline Overflow Volume and Pollutant Loading Calculations 

Estimated Storage Lagoon Volume if Constructed: 58,200 ft3 (435 thousand gallons) 

Process Waste Generation: 374 ft3

/day (2,800 gal/day) 

Volume of Liquids and Solids in Lagoon at Start: 635 ft3

 (Sludge Volume + Minimum Treatment 

Volume + Accumulated Process Wastes 

Since Last Liquid Application) 

Precipitation Volume (average): 61 in/yr 

Evaporation Rate (average): 90 in/yr 

Sludge Volume (constant): 5,900 ft3 

Minimum Treatment Volume (constant): 9,200 ft3 

Assumed removal rate: 2x per month from January 21 to December 9 

5-18
Chapter 5: Voluntary Performance Standards for CAFOs 

Example 3: Birvan Egg Farms, Okeechobee County, FL 

Calculated Baseline Overflow Volume Method: 

Daily accumulation of lagoon liquids (ft3

/day) = Process Waste (ft3/day) + [Precipitation - Evaporation 

(ft/day)] x Lagoon Surface Area (ft2

) 

Volume of Lagoon Liquids (ft3

) = Previous days volume (ft3) + Accumulation volume 

(ft3

/day) 

If the Volume of Lagoon Liquids (ft3) is greater than the following: 

Existing Storage Lagoon Volume (ft3

) - Sludge Volume (ft3) - Minimum Treatment Volume (ft3)], then 

Overflow Volume = Volume of Lagoon Liquids (ft3

) - [Existing Storage 

Lagoon Volume (ft3) - Sludge Volume (ft3) - Minimum 

Treatment Volume (ft3

)]; and 

Volume of Lagoon Liquids (ft3

) is adjusted to the following: 

[Existing Storage Lagoon Volume (ft3

) - Sludge Volume (ft3) - Minimum Treatment Volume (ft3)] (the

maximum volume of liquids the lagoon can store)

Model Calculated Overflow Volume for Birvan: 3,162 ft3

/yr (23,651 gal/yr) 

Birvan collected a representative sample of liquid from the digester to calculate the annual loading of 

BOD5, total nitrogen, total phosphorous, and total suspended solids (TSS) that would be discharged as 

a result of the overflow volume. The sample was collected from the top 12 inches of the digester 

surface since the majority of overflows will likely be attributed to this zone. The sampling results are 

shown below: 

BOD5: 1,500 mg/L 

Total nitrogen: 750 mg/L 

Total phosphorus: 100 mg/L 

TSS: 3,200 mg/L 

Based on the overflow and the measured concentration, the annual pollutant discharges from the 

storage system was calculated by multiplying the flow by the concentration as shown in the example for 

BOD5 below: 

BOD5 : 1500 mg/L x 3.785 L/gal x 23,651 gal/yr x 2.2 lbs/kg x 1 kg/106

 mg = 295 lbs/yr 

A summary of the pollutant loadings based on the overflow rate and concentration is shown below. 

BOD5: 295 lbs/yr 

Total nitrogen: 148 lbs/yr 

Total phosphorus: 20 lbs/yr 

TSS: 433 lbs/yr 

Treatment System Evaluation 

Birvan has been collecting monthly samples for BOD5, total nitrogen, total phosphorous, and total 

suspended solids from the existing treatment system since early 1997. The measured monthly 

concentrations in the treatment system effluent and the total flow through the treatment system over the 

past 12 months is shown below. 

5-19
Chapter 5: Voluntary Performance Standards for CAFOs 

Example 3: Birvan Egg Farms, Okeechobee County, FL 

Measured Treatment System Effluent Concentration and Total Influent Flow During the Past 12 

Months 

Month BOD5 

(mg/L) 

Nitrogen 

(mg/L) 

Phosphorous TSS 

(mg/L) (mg/L) 

Total Flow 

(gal) 

June 20 3.3 0.6 14 83,800 

July 21 5.2 0.8 15 83,200 

August 13 1.6 0.7 10 84,600 

September 8 0.8 0.6 9 83,900 

October 9 0.6 0.4 7 84,200 

November 18 3.5 0.6 13 84,700 

December 13 2 0.7 11 84,300 

January 6 0.7 0.4 9 82,900 

February 8 0.7 0.4 8 83,900 

March 19 1.8 0.8 13 84,700 

April 20 4.2 1.2 15 85,100 

May 7 2.7 0.8 14 84,300 

Median 13 1.9 0.6 12 84,250 

As shown in the figure below, the vibrating membrane filter generates a concentrated waste stream 

equaling 20% of the influent flow (16,850 gal/month). This concentrated waste stream is sent to a 

10,000 gallon holding tank prior to off-site shipment. Effluent from the vibrating membrane filter enters 

a lift station where submersible pumps transfer approximately 45,000 gallons per month back to the 

layer house for manure flushing. Based on a measured average flow rate of approximately 22,400 

gallons per month at Outfall 001 and the concentration of pollutants in the vibrating membrane 

treatment system effluent, the following annual loadings to St. Lucie Canal were calculated and 

compared to the baseline overflow loadings. 

Comparison of the Calculated Baseline Overflow Discharge to the Treatment System Discharge 

Pollutant Baseline Overflow Treatment System Discharge 

(lbs/yr) (lbs/yr) 

BOD5

Total nitrogen

Total phosphorous

TSS

295 29 

148 4.2 

20 1.3 

433 27 

Conclusion: The comparison shows that the existing treatment systems consisting of an anaerobic 

digester and vibrating membrane filtration system achieves better performance than the baseline 

system for all targeted pollutants. If water quality constraints for fecal coliform in the St. Lucie canal 

make additional treatment necessary, Birvan is also considering increasing the temperature of the 

digester to make it thermophilic, a practice known to reduce fecal coliform in the effluent. 

5-20
Chapter 5: Voluntary Performance Standards for CAFOs 

Example 3: Birvan Egg Farms, Okeechobee County, FL 

Diagram of Existing Treatment System 

4. Future Case Studies 

EPA may provide additional case studies in the future, such as examples of whole-farm 

multi-media evaluations, voluntary alternative standards as applied to silage leachate, or 

alternative technologies for handling mortalities. Additional suggestions and recommendations 

may be sent to EPA at the address provided in Chapter 1 of this document. 

5-21
CHAPTER 6: DEVELOPING AND USING TECHNICAL STANDARDS FOR THE LAND

APPLICATION OF MANURE, LITTER, AND PROCESS WASTEWATER ........ 6-1

A. Developing Technical Standards for Land Application .................. 6-1

1. EPA Recommended Technical Standards and Policies ........... 6-1

2. Factors for Developing Technical Standards ................... 6-4

3. NRCS Standards and NMPs ................................ 6-4

4. Example National Nutrient Management Technical Standards for Land

Application .............................................. 6-5

5. Appropriate Flexibility in Applying Technical Standards ........... 6-5

B. Example Rate Calculations ....................................... 6-6

1. Manure Production and Composition ......................... 6-6

2. Developing a Nutrient Budget ............................... 6-8

3. Land Application Rate Calculation .......................... 6-11

C. Manure Management Planner ................................... 6-12
Chapter 6: Developing and Using Technical Standards 

CHAPTER 6: DEVELOPING AND USING TECHNICAL STANDARDS FOR THE LAND 

APPLICATION OF MANURE, LITTER, AND PROCESS WASTEWATER 

The CAFO effluent guidelines require Large CAFOs to develop and use site-specific 

nutrient application practices that are in compliance with the technical standards for nutrient 

management established by their permitting authority. Permitting authorities establish technical 

standards to minimize phosphorus and nitrogen transport to surface water. The effluent 

guidelines call for technical standards that establish methods and criteria for determining 

application rates that balance the nutrient needs of crops with the potential adverse impacts on 

water quality. 

This chapter provides guidance on how permitting authorities may establish technical 

standards and other land application considerations. This chapter also presents Manure 

Management Planner as a resource for Nutrient Management Plan (NMP) development, some 

example calculations for determining land application rates, and NMP case studies using 

Manure Management Planner. 

A. Developing Technical Standards for Land Application 

Technical standards for the land application of manure, litter, and/or process wastewater 

must include a field-specific assessment of the potential for nitrogen and phosphorus transport 

from the field to waters of the U.S. In addition, the standards must address the form, source, 

amount, timing, and method of application of nutrients on each field to achieve realistic 

production goals, while minimizing nitrogen and phosphorus movement to waters of the U.S. To 

develop technical standards for land application, permitting authorities may use the NRCS 

Nutrient Management Conservation Practice Standard, Code 590, (see Section A.4 of this 

chapter) or other appropriate technical standards as guidance. It should be noted, however, 

that consistency with NRCS Code 590 may not by itself ensure compliance with the regulatory 

requirements for technical standards for nutrient management (see 40 CFR 123.36) 

1. EPA Recommended Technical Standards and Policies 

EPA has developed a “National Nutrient Management Technical Standard” to guide the 

permit authority (regions and states) in developing and using technical standards. The 

“National Nutrient Management Technical Standard” is provided in Appendix O. The purposes 

of the technical standards are to enable agricultural users of nutrients to: 

C Minimize pollution of surface 

and ground water resources Nutrient Management Definition 

from agricultural nutrient 

sources; Planned process to protect water quality by 

managing the amount, source, placement, 

C Budget and supply nutrients 

for plant production; 

form, and timing of agricultural wastes and 

soil amendments utilized for the production 

of crop, forage, fiber, and forest products. It 

C Properly use manure, litter, 

process wastewater, and/or 

other organic by-products as a 

plant nutrient source; 

is supplying essential nutrients in adequate 

amounts to balance and maintain the soil for 

healthy biology and quality plants while 

avoiding conditions inimical to the 

ecosystem. 

6-1
Chapter 6: Developing and Using Technical Standards 

C Maintain or improve the physical, chemical, and biological condition of the soil; 

and 

C Prevent or reduce excess nutrient concentrations in the soil. 

This chapter describes how the content of NMPs are based on the technical standards, 

including the field risk assessment, determination of land management units, nutrient 

application rate development, nutrient application timing and methods, areas of special 

consideration, and operation and maintenance practices. This chapter also provides additional 

recommendations for sampling (e.g., soil, plant tissue, manure and process wastewater) and 

guidelines for laboratory analyses. 

The Field Risk Assessment 

CAFOs must perform field-specific risk assessments to determine whether manure 

nutrients should be applied at a nitrogen or phosphorus application rate, or whether land 

application should be avoided under state technical standards. CAFOs must use the stateapproved method. Currently, most states have adopted one of the three field risk assessments 

defined in the NRCS Nutrient Management standards. The three field risk assessments defined 

in the NRCS Nutrient Management standards are: 1) Phosphorus Index; 2) Soil Phosphorus 

Threshold Level; and 3) Soil Test Phosphorus Level. 

In some instances phosphorus levels in soils are so high, or site-specific conditions 

(e.g., highly erodible soils) are such that any application of manure, litter, or process 

wastewaters would be inconsistent with appropriate agricultural utilization of nutrients. Such 

instances would lead to excessive levels of nutrients and other pollutants in runoff. EPA 

expects that these factors will be taken into account as state permitting authorities develop 

appropriate technical standards for the land application of manure by CAFOs. 

To reduce a field-specific risk, CAFOs may apply conservation practices, best 

management practices, or management activities to their land application areas to reduce 

nutrient transport to surface waters. For example, a CAFO may be able to implement the 

conservation plan components of a CNMP to a field to reduce the field’s risk rating, often 

resulting in increased flexibility to land apply manure. 

Responsibilities 

The CAFO rules require the permit authority to develop the technical standards for 

nutrient management. Large CAFOs have, under their permits, a responsibility to develop their 

NMP to meet the state technical standards and other requirements. 

In developing NPDES permits, permit writers use the effluent guidelines, NPDES CAFO 

rule, and the technical standards for nutrient management. Development of the NPDES permit 

and how technical standards affect permits is discussed in EPA’s NPDES Permit Writer’s 

Guidance Manual and Example NPDES Permit for Concentrated Animal Feeding Operations 

(EPA-833-B-04-001). The NPDES regulations provide that the permitting authority must 

establish technical standards for nutrient management that are consistent with the requirements 

in 40 CFR 412.4(c)(2) (also see 40 CFR 123.36). The permitting authority must include in the 

technical standard, at a minimum, the methodologies necessary to address the following 

components of a NMP: 

6-2
Chapter 6: Developing and Using Technical Standards 

C Field-specific assessment of the potential for nitrogen and phosphorus transport 

from the field to waters of the U.S.; 

C Form, source, amount, timing, and method of application of nutrients on each 

field to achieve realistic production goals, while minimizing nitrogen and 

phosphorus movement to waters of the U.S.; and 

C Appropriate flexibility for CAFOs to implement the standard (e.g., multi-year 

phosphorus banking, 40 CFR 412.4(c)(2)(ii)). 

EPA strongly encourages states to address water quality protection issues when 

establishing technical standards (i.e., appropriate land application practices). EPA expects that 

state and Tribal technical standards for nutrient management will be developed collaboratively 

among the respective state departments of agriculture, Tribes, NRCS state conservationists, 

state Land Grant Universities, and NPDES permitting authorities. 

Coordination/Communication to Develop Technical Standards and NMPs 

EPA expects that permitting authorities will provide guidance to CAFOs on how to 

implement the state technical standards, in coordination with their state agricultural agency 

partners. In addition, EPA believes that a well-prepared Comprehensive Nutrient Management 

Plan (CNMP) prepared in accordance with the CNMP Technical Guidance issued by USDA’s 

NRCS should in most instances help the CAFO meet the NMP and minimum practice 

requirements of the permit, including the requirement to comply with the state technical 

standards (although whether a CNMP is adequate to meet these requirements is ultimately 

judged on a case-by-case basis). 

CAFO owners and operators should Nutrient Management Planning Tools seek technical assistance for developing 

NMPs from integrators, industry associations, Many states, universities, and private sector and private consultants. In addition, federal companies have developed nutrient agencies, such as the NRCS, as well as management tools that can be used state and Tribal agricultural and conservation (generally within a specific state) to assist agency staff, Cooperative Extension Service livestock and poultry producers develop agents and specialists, Soil and Water site-specific nutrient management plans. Conservation Districts, and Land Grant One example of such tools is Manure Universities may be able to provide technical Management Planner (MMP), developed at assistance. A number of computer-based Purdue University. This is a manure tools are being developed to facilitate the utilization planning tool to help develop development and implementation of NMPs. nutrient management plans. Access MMP For example, see CNMP Watch at 

at http://www.agry.purdue.edu/mmp/. http://www.cnmpwatch.com/ , a web site of 

the National Association of State 

Departments of Agriculture (NASDA) 

Research Foundation, for an update on nutrient management planning. 

NMPs are complex documents that require knowledge in a number of different areas. 

Therefore, CAFO personnel should undergo general nutrient management training to 

understand plan components and to successfully implement the plan. Free training, which lasts 

6-3
Chapter 6: Developing and Using Technical Standards 

between one and four days, is often available from state agricultural Cooperative Extension 

Offices. 

The CAFO rules do not require the use of a certified specialist to develop a NMP; 

however, EPA encourages CAFOs to use certified planners with expertise to develop, modify, or 

review their NMPs. See Chapter 4 of this document for more information. 

2. Factors for Developing Technical Standards 

Technical standards should be developed to consider various factors for CAFOs, such 

as site-specific production data, watershed and jurisdictional boundaries, local environmental 

issues, and climate and natural resources. Permitting authorities should develop land 

application technical standards to address the types of crops grown, number of animals at the 

CAFO, nutrient concentrations in the manure, and other nutrient sources. 

CAFOs may be subject to multiple technical standards if located near watershed or 

jurisdictional boundaries. For example, the permitting authority may develop stricter technical 

standards for an impaired water body. CAFOs should work with their permitting authority to 

determine the applicable technical standards. 

Different regions of the country may need to review specific environmental issues for 

their area. States may develop different technical standards for urbanized vs. rural areas. 

Stricter technical standards may be applied to CAFOs located near impaired watersheds (e.g., 

the Chesapeake Bay, Gulf of Mexico). 

The climate and natural resources of an area directly affect the land application of 

manure, litter, and process wastewater. When permitting authorities develop the technical 

standards (and when CAFOs develop their NMP), factors they should consider include type of 

soil, air quality issues that may affect management practices, and health issues (e.g., high 

levels of heavy metals or pathogens in the manure). For example, CAFOs located west of the 

Mississippi River tend to have water deficient and calcareous soils, while CAFOs located east of 

the Mississippi River tend to have water excess and acidic soils. 

3. NRCS Standards and NMPs 

Many technical standards for nutrient management have already been developed as part 

of implementing USDA’s National Nutrient Management policy. NRCS developed a national 

Nutrient Management Conservation Practice Standard (Code 590) that serves as a basis for 

each state NRCS office to develop its own tailored standard. Almost all States have developed 

a Phosphorus Index as part of their states’ Nutrient Management Conservation Practice 

Standard (Code 590). EPA expects that in most cases States have relied or will rely on these 

NRCS standards to form the basis for the technical standards established by the permitting 

authority. 

The USDA’s CNMP guidance contains six key elements: 1) manure and wastewater 

handling and storage; 2) nutrient management; 3) land treatment practices; 4) recordkeeping; 5) 

feed management; and 6) other manure and wastewater use options. As discussed in Chapter 4 

of this document, EPA endorses the CNMP approach but cautions CAFOs that following 

USDA’s CNMP Guidance does not guarantee that a CAFO’s CNMP will adequately address all 

of the minimum elements that are required by the regulations for a nutrient management plan. 

6-4
Chapter 6: Developing and Using Technical Standards 

See the Permit Writers Guidance for a comparison of USDA’s CNMP six elements and EPA’s 

minimum measures. 

The NRCS web site provides technical guidance to develop NMPs including a national 

template at http://www.nrcs.usda.gov/technical/references/. NRCS and EPA permitting 

authorities may have different definitions and requirements for nutrient management plans. 

Therefore, to meet the requirements for a NMP that complies with state technical standards, 

CAFOs may need to modify the elements of current NMPs or NMPs developed using NRCS 

standards. Appendix C includes a checklist that CAFOs may use to help ensure all 

requirements have been addressed in the NMP. 

4. Example National Nutrient Management Technical Standards for Land Application 

EPA has developed a “National Nutrient Management Technical Standard,” set forth in 

Appendix O. EPA intends to apply this example technical standard in states where EPA is the 

permitting authority. States may use this technical standard as guidance in developing state 

technical standards for land application. 

In those States where EPA is the permitting authority and required to establish the 

technical standards for nutrient management, 

this guidance recommends the use of the 

EPA Example Technical Standard in Example State Technical Standards for

conjunction with the State's conservation Winter Applications

practice for nutrient management (590) for When frozen soils prevent effective this purpose. Upon review of the State's 590, incorporation of nutrients at the time of any missing items required by the CAFO application do not apply nutrients: rules must be included in the terms and 

(a) within Surface Water Quality conditions of the NPDES permit. Management Areas (1,000 feet of lakes, or 

within 300 feet of perennial streams). 5. Appropriate Flexibility in Applying Identify perennial streams using the NRCS Technical Standards 

soil survey and/or USGS 1:24,000 scale 

topographic map. State regulations (including technical (b) within 200 feet upslope of wells, standards) may be more restrictive than the sinkholes, fractured bedrock at the surface, federal CAFO regulations. For example, the or gravel pits identified by the planner. state may establish the specific conditions (c) on slopes greater than 9%, except for and criteria applicable to winter spreading of 

manure. manure on slopes up to 12% with

concentrated flow channels maintained in 

The permitting authority and CAFO permanent vegetative cover. Slopes from

9% to 12% must be either contour should look at the appropriateness of certain stripcropped with alternate strips in requirements in the technical standards in perennial forage or contour farmed where all how they apply at that site. Examples of the residue from the previous corn crop include practicality of manure, litter, and (harvested for grain) remains on the soil process wastewater storage, allocation, and surface. Areas that do not contribute runoff application; equipment calibration and to surface water or groundwater conduits limitations; accessibility of records (e.g., feed 

management component of NMP with may be exempted based on an in-field

evaluation. Do not apply any nutrients on integrator-supplied feed); and available data slopes greater than 12%. (e.g., crop, soil, or feed information). In 

6-5
Chapter 6: Developing and Using Technical Standards 

developing the technical standards, the permitting authority shall also include appropriate 

flexibility for any CAFO to implement nutrient management practices to comply with the 

technical standards, as described above. 

B. Example Rate Calculations 

Large CAFOs must use the technical standards developed by the permitting authority to 

write a NMP. Chapter 4 of this manual discusses the aspects of the NMP in more detail. This 

section provides examples for calculating application rates. To properly manage manure, litter, 

and process wastewater, CAFOs must determine amount of manure produced, manure 

composition, nutrient requirements for crops, and the appropriate application rate (nitrogenbased or phosphorus-based). Throughout this section, an example dairy farm will be used to 

demonstrate the calculations. These examples are for illustrative purposes only. 

1. Manure Production and Composition 

To develop appropriate manure application rates, CAFOs must estimate the amount and 

composition of manure, litter, and process wastewater available for land application. The 

amount of manure generated at a CAFO is directly linked to the number of animals maintained. 

However, because the composition of manure changes as it ages, the amount collected and 

applied to the land is often much less than the amount generated by the animals. Therefore, 

CAFOs should estimate the amount of manure that will be available for land application by 

calculating the volume of manure, litter, and process wastewater stored on site and/or by 

calculating the quantity of manure removed during cleaning times. 

Because the nutrient content of manure depends on many site-specific practices, 

CAFOs may NOT use book values of manure to develop NMPs. CAFOs must sample the site 

manure at least annually and should send the samples to an accredited laboratory for analyses 

of at least total nitrogen (N) and phosphorus (P). Because it is a primary essential element for 

plant growth, CAFOs should also sample for potassium (K). See Chapter 4, Section A.2 and 

Appendix E of this manual for further details on manure sampling. 

Example: Calculations for a Dairy Farm 

Site Description 

The Dairy Farm houses approximately 800 cows on site annually. The average herd/flock size 

includes 500 lactating cows, 150 heifers, 100 dry cows, and 50 calves. 

The Dairy Farm uses a waste storage lagoon to store process wastewater (liquid wastes) from 

the milking center and flush barns, runoff from the feedlot, and direct precipitation into the lagoon. The 

farm treats wastewater from the milking center and flush barns in a solid/liquid separator prior to 

discharge into the storage lagoon. The site uses a concrete slab to store solid manure and litter wastes 

from the dry lot, barns, and solid/liquid separator. 

Calculating the Amount of Manure Produced and Collected Annually 

Solid Manure: The Dairy Farm collects solid manure from the barns where the dry cows and 

heifers are housed and the dry lot where the calves are housed. By weighing the front-end loader 

before and after a load of manure is removed from the dry lot, the site calculates that approximately 

8,000 pounds of manure are collected weekly. The manure is then transferred to a concrete slab for 

6-6
Chapter 6: Developing and Using Technical Standards 

Example: Calculations for a Dairy Farm 

storage until land application. 

In addition, the liquid/solids separator generates 31,000 pounds of solids daily. This quantity is 

also calculated by weighing the front-end loader before and after removing the solids. 

The annual collection of manure solids is calculated from the following equation: 

Solid Manure = (8,000 lbs/week x 52 weeks/year) + (31,000 lbs/day x 365 days/year) 

= 11,731,000 lbs/year ÷ 2000 lbs/ton 

= 5,865 tons/year 

Calculating the Amount of Manure Produced and Collected Annually (Continued) 

Liquid Manure: Process wastewater collected and stored in the waste storage pond consists 

of flush water from the milking center (parlor, holding area, and milk room); flush water from the freestall 

barns where the milking cows are housed; runoff from the feedlot; and direct precipitation. An estimated 

total of 6.6 million gallons per year of liquid manure is produced at the operation. The following 

calculations are used to estimate the quantity of liquid manure produced and collected at The Dairy 

Farm. 

Milking Center - The Dairy Farm estimates approximately 30 gallons of cleaning water is used 

per lactating cow each day. 

= 30 gallons/cow/day x 500 lactating cows

= 15,000 gallons/day x 365 days/yr

= 5,475,000 gallons/yr

Flush Barns - Most of the water used to flush the freestall barns is recycled from the lagoon. 

However, one day’s worth of flushing water (approximately 100 gallons per cow) is included in 

the total liquid waste as part of the lagoon’s design capacity. Only lactating cows, dry cows, 

and heifers are included in this calculation; the calves are kept on dry lots. 

= 100 gallons/cow/day x 750 lactating and dry cows 

= 75,000 gallons/yr 

Runoff - The runoff collection area totals 15 acres. The annual precipitation is approximately 5 

inches, with 40% runoff from the dry lot. 

= 15 acres x 43,560 square feet/acre x (5 inches/yr ÷12 inches/feet) x 40%

= 108,900 cubic feet/year

Conversion to gallons:

= 108,900 cubic feet/year x 7.48 gallons/cubic feet

= 814,572 gallons/year

Direct Precipitation - The size of the lagoon is 200 feet by 425 feet and the annual precipitation 

is 5 inches. 

= (5 inches/year ÷ 12 inches/feet) x 200 feet x 425 feet

= 35,417 cubic feet/year

Conversion to gallons:

= 35,417 cubic feet/year x 7.48 gallons/cubic feet

= 264,919 gallons/year

6-7
Chapter 6: Developing and Using Technical Standards 

Example: Calculations for a Dairy Farm 

Total Liquid Manure = (5,475,000 + 75,000 + 814,572 + 264,919) gallons/year 

= 6,629,500 gallons/year 

The total amount of manure, litter, and process wastewater produced annually is 5,865 tons of solids 

and 6.6 million gallons of liquids. 

Manure Sampling Analysis 

Solid Manure Sampling - The Dairy Farm samples the manure stored on the concrete slab 

using a hand-made sampling device (similar to a soil auger). The sampling includes collecting six 

random samples from wastes stored on the slab and mixing all six samples together. 

Liquid Manure Sampling - The Dairy Farm samples the waste storage lagoon using a plastic 

cup attached to a long pole. The sampling includes collecting eight random samples from around the 

shoreline of the lagoon and mixing all eight samples together. 

Manure Sampling Results 

Solid Manure: Total Kjedahl Nitrogen (TKN) - 9 pounds/ton

Total Phosphorus - 3 pounds/ton

Potassium - 6 pounds/ton

pH - 7.4

Liquid Manure: Total Kjedahl Nitrogen (TKN) - 12 pounds/1,000 gallons

Total Phosphorus - 6 pounds/1,000 gallons

Potassium - 10 pounds/1,000 gallons

pH - 7.5

2. Developing a Nutrient Budget 

CAFOs must estimate the nutrient requirements of the soils where manure, litter, and 

process wastewater will be land applied. This includes sampling the soil, planning of the crops, 

and recommended crop nutrient requirements. The recommended nutrient requirements are 

generally provided by the local Cooperative Extension Office and based on planned crops, 

expected crop yields, and current soil test results. 

Example: Calculations for a Dairy Farm 

Site Description 

The Dairy Farm owns and operates a total of 400 acres; 375 acres of cropland and 25 acres for 

the dairy operation. No land is currently rented. The Dairy Farm uses two fields for land application: 1) 

Field 1 with 250 acres; and 2) Field 2 with 125 acres. 

6-8
Chapter 6: Developing and Using Technical Standards 

Example: Calculations for a Dairy Farm 

Soil Sampling 

The soils of both fields used for land application are sampled separately. The results of the 

samples are below. 

Field 1: Nitrogen - 20 pounds/acre

Phosphorus - 75 pounds/acre

Potassium - 90 pounds/acre

pH - 6.2

Soil Organic Matter: 2.2%

Field 2: Nitrogen - 25 pounds/acre

Phosphorus - 110 pounds/acre

Potassium - 110 pounds/acre

pH - 5.8

Soil Organic Matter: 2.6%

For Field 1, the phosphorus concentration is not high (defined as greater than 100 pounds per 

acre according to the state technical standards); therefore, the land application rate of manure may be 

up to and including the nitrogen-based rate. For Field 2, the phosphorus concentration is “high” (i.e., 

>100 pounds/acre); therefore, the land application rate of manure must be no greater than the 

phosphorus-based rate. 

Crop Yields 

The crop production history for the previous five years is used to estimate crop yields. 

Field Number Year Crop Crop Yield (tons/acre) 

1 199920002001 Alfalfa 556 

1 20022003 Corn-silage 2022 

1 20022003 Winter wheat 34 

2 199920002001 Corn-silage 232120 

2 20022003 Alfalfa 55 

Example: Calculations for a Dairy Farm 

The Dairy Farm plans to plant corn-silage in both fields in April 2004 (harvested September 

2004) and winter wheat in both fields in September 2004 (harvested December 2004). The expected 

crop yield is calculated using the average historical crop yield: 

Field 1, Corn-silage Yield Estimate = (20 tons/acre + 22 tons/acre)/2 

= 21 tons/acre

Field 1, Winter Wheat Yield Estimate = (3 tons/acre + 4 tons/acre)/2

= 3 tons/acre

6-9
Chapter 6: Developing and Using Technical Standards 

Example: Calculations for a Dairy Farm 

Field 2, Corn-silage Yield Estimate = (23 tons/acre + 21 tons/acre + 20 tons/acre)/3 

= 21 tons/acre 

Field 2, Winter Wheat Yield Estimate: use 3 tons/acre since no crop yield history data are 

available. 

Recommended Crop Nutrient Requirements 

The Dairy Farm uses information from the local Cooperative Extension Office, expected crop 

yields, and soil test results to determine recommended crop nutrient requirements. 

Field Number Crop 

Nutrient Requirements 

(Nitrogen) 

Nutrient Requirements 

(Phosphorus) 

1 Corn-silage 180 pounds/acre 20 pounds/acre 

1 Winter wheat 40 pounds/acre 30 pounds/acre 

2 Corn-silage 180 pounds/acre 20 pounds/acre 

2 Winter wheat 40 pounds/acre 30 pounds/acre 

Example: Calculations for a Dairy Farm 

Nutrient Credits 

Nutrient credits for nitrogen include previous legume crops, residual nitrogen from previous 

manure applications, nitrogen from irrigation water, and other sources. Field 1 planting did not include 

a legume crop the previous year, therefore there is no nitrogen credit for legume crops. The Dairy Farm 

applied manure at a rate of 100 pounds of nitrogen per acre for the past two years. The residual 

nitrogen is calculated by multiplying the mineralization factor by the manure application rate for the 

previous years. The following mineralization factors, obtained from the local Cooperative Extension 

Office, are used for the calculation: 12% for one year ago and 5% for two years ago. 

Residual Nitrogen = 0.12 x 100 lb/acre + 0.05 x 100 lb/acre

= 17 lb/acre

The Dairy Farm will apply a starter commercial fertilizer to Field 1 prior to planting the cornsilage, resulting in a nitrogen credit of 10 pounds per acre. Based on tests of the irrigation water 

performed by the county, only a very small concentration of nutrients are present in the water. This 

nitrogen concentration is assumed negligible. The local Cooperative Extension Office did not identify 

any other nutrient credits. 

Total Nitrogen (N) Credit for Field 1 = 0 (legume crop) + 17 lb/acre (residual N) + 10 

lb/acre (fertilizer) + 0 (irrigation water) + 0 

(other sources) 

= 7 lb nitrogen/acre 

6-10
Chapter 6: Developing and Using Technical Standards 

Example: Calculations for a Dairy Farm 

Field 2 has no phosphorus nutrient credits. 

3. Land Application Rate Calculation 

Using the recommended crop nutrient requirements and nutrient credits, CAFOs can 

calculate the land application rate of manure, litter, and process wastewater. Land applications 

are typically either nitrogen-based or phosphorus-based. See Chapter 4, Section B.6 for more 

details. In the example below, if the phosphorus concentration in the soil is “high” (as indicated 

by laboratory results), or the PI rating is “high”, the CAFO would use a phosphorus-based 

application rate. 

Example: Calculations for a Dairy Farm 

Field 1 Nitrogen-Based Land Application Rate 

Field 1 land application will be nitrogen-based. The amount of nitrogen in the manure available 

to the crops during the first year of application (Plant Available Nitrogen, PAN) is 5 pounds per ton of 

solid manure and 5.8 pounds per 1,000 gallons of liquid manure. The following equation is used to 

estimate the manure application rate of nitrogen. 

Manure Application Rate = Recommended Crop Nutrient Requirements - Nutrient 

Credits 

Field 1, Corn-silage = 180 lb/acre - 27 lb/acre

= 153 lb/acre

Field 1, Winter Wheat = 40 lb/acre - 27 lb/acre

= 13 lb/acre

The Dairy Farm will apply liquid manure to Field 1 at the following rates: 

Liquid Manure Application Rate (Field 1, Corn-silage) = 153 lb/acre ÷ 5.8 lb PAN/1,000 

gallons 

= 26,380 gallons/acre 

Liquid Manure Application Rate (Field 1, Winter wheat) = 13 lb/acre ÷ 5.8 lb PAN/1,000 

gallons 

= 2,240 gallons/acre 

Field 2 Phosphorus-Based Land Application Rate 

Field 2 land application will be phosphorus-based. The Dairy Farm assumes that 100% of the 

phosphorus in the manure will be available to the plants. The following equation is used to estimate the 

manure application rate of phosphorus. 

Manure Application Rate = Recommended Crop Nutrient Requirements - Nutrient 

Credits 

Field 2, Corn-silage = 20 lb/acre - 0 lb/acre

= 20 lb/acre

6-11
Chapter 6: Developing and Using Technical Standards 

Example: Calculations for a Dairy Farm 

Field 2, Winter Wheat = 30 lb/acre - 0 lb/acre 

= 30 lb/acre 

The Dairy Farm will apply solid manure to Field 2 at the following rates: 

Solid Manure Application Rate (Field 2, Corn-silage) = 20 lb P/acre ÷ 3.0 lb P/ton 

= 6.7 tons/acre 

Solid Manure Application Rate (Field 2, Winter wheat) = 30 lb P/acre ÷ 3.0 lb P/ton 

= 10 tons/acre 

C. Manure Management Planner 

As far as NMP tools go, the Manure 

Management Planner (MMP) is probably one 

of the most efficient and comprehensive 

planning tools to use. MMP is nationally 

Manure Management Planner 

Developed at Purdue University, MMP is a 

Windows-based computer program that is 

used to create manure management plans 

for crop and animal feeding operations. The 

user enters information about the operation's 

fields, crops, manure storage, animals, and 

application equipment. MMP helps the user 

allocate manure (where, when and how 

much) on a monthly basis for the length of 

the plan (1-10 years). This allocation 

process helps determine if the current 

operation has sufficient crop acreage, 

seasonal land availability, manure storage 

capacity, and application equipment to 

manage the manure produced in an 

environmentally responsible manner. The 

planner can use the program with the CAFO 

manager to determine the most efficient 

utilization of manure in iterative processes, 

allowing the CAFO/farm manager to 

determine not only how and where to utilize 

manure, but also how to revise their own 

plans of crop rotation to maximize nutrient 

uptake and long-term land application. MMP 

is also useful for identifying changes that 

may be needed for a non-sustainable 

operation to become sustainable, and 

determining what changes may be needed 

to keep an operation sustainable if the 

operation expands. 

6-12
Chapter 6: Developing and Using Technical Standards 

supported by both EPA1

 and USDA-NRCS for nutrient management planning. MMP 

automatically calculates Extension fertilizer recommendations and manure nutrient availability 

automatically in accordance with state NRCS 590 standards. MMP automatically imports field 

data from Missouri's Spatial Nutrient Management Planner (SNMP) GIS, which is also 

supported nationally by EPA for nutrient management planning. MMP can be set to 

automatically import data from soil test labs and Customer Service Toolkit. MMP currently 

supports 25 states: AL, AR, DE, FL, GA, IN, IL, IA, KS, MA, MI, MN, MO, MS, MT, NE, ND, NM, 

OH, OK, PA, SD, TN, UT and WI. 

Manure Management Planner (MMP) is freely obtained from 

www.agry.purdue.edu/mmp. Full technical documentation can be downloaded from 

www.agry.purdue.edu/mmp/MmpDocs.htm. 

SNMP is also free (www.cares.missouri.edu/snmp) 

1

EPA is publishing this information in an effort to further public understanding of how a manure utilization 

planning tool can be used to develop nutrient management plans that can further efforts to protect our 

environment. The EPA does not endorse products nor does it recommend for or against the purchase of 

specific products. 

6-13 
CHAPTER 7: AVOIDING COMMON DEFICIENCIES .............................. 7-1

A. Proactive Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

B. Common Deficiencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

1. Inadequacy of Storage Capacity ............................. 7-2

2. Infrequent Dewatering of Storage Structures ................... 7-2

3. Pumpdown Practices ..................................... 7-2

4. Lagoon Agitation ......................................... 7-2

5. Representative Manure Samples ............................ 7-3

6. Animal Mortality Practices .................................. 7-3

7. Chemical Handling ....................................... 7-3

8. Emergency Action Plans ................................... 7-4

9. Example Onsite Check List ................................. 7-5
Chapter 7: Avoiding Common Deficiencies 

CHAPTER 7: AVOIDING COMMON DEFICIENCIES

Historically, the majority of discharges from CAFOs occur from manure handling

systems and during the land application of manure. In most cases, the discharge did not occur

during a rainfall event. In many cases, the discharge could have been avoided through better

planning, management, and operation of the CAFO. Even though proper operation and

maintenance is a standard permit condition, it is often helpful to simply be aware of the types of

deficiencies that may ultimately lead to a discharge. This chapter focuses on the more common

deficiencies that may lead to permit violations, pollutant discharges, or both, and provides some

tools CAFOs may use to avoid such deficiencies. 

Disclaimer: The purpose of this chapter is to give examples of practices that could lead to a 

CAFO being out of compliance with its permit requirements. These examples are not intended 

to comprehensively describe the CAFO regulatory requirements and the full set of practices that 

are necessary for a CAFO to remain in compliance. For more information, visit the Agriculture 

Compliance Assistance Center website at http://www.epa.gov/agriculture/. 

A. Proactive Management 

Norton et. al. (1996) developed a Example: Permit Violations in North Carolina dual approach of developing management

plans and conducting farm inspections for A review of permit violations on concentrated addressing key aspects of pollution risk animal feeding operations in North Carolina management: proactive found that two hundred eighty-five (285) management and reactive management. discharges occurred between 1996 and 2000. Proactive management involves identifying Forty-two percent (42%) of discharges from the potential for any discharge, assessing swine facilities were related to the land 

what can be done to minimize the risk of application of lagoon effluent and thirty-nine

discharge, and then taking steps to ensure percent (39%) were from the manure handling 

systems. Lagoon liquid levels were observed to the potential discharge does not occur. In be exceeding the lagoon's 25-year, 24-hour contrast, reactive management deals with the storm storage level at over 80% of all visits. actions necessary to respond to a discharge

and then implementing measures to prevent Source: Sheffield, 2002. an incident from reoccurring. Many state spill

response plan requirements and the

Environmental Management System

guidelines for ISO14000 certification (ASQ,1996) require addressing incidents such that they do 

not recur. 

Resources are available to help a CAFO to determine an accurate environmental profile

for their operation. For example, the National Livestock Producers Association (NLPA) and

Environmental Management Solutions, LLC, formed a clearinghouse for the On-Farm

Assessment and Environmental Review (OFAER) program. The OFAER Program provides a

free, confidential assessment of animal production facilities and is available to the producer

through NLPA. The program helps give producers an edge regarding the public’s perception of

their operation and offers cost savings by taking advantage of a third party’s animal production

and environmental stewardship knowledge. The OFAER program can help all operations learn

what strengths and challenges face the operation, as well as offer helpful recommendations

concerning these issues. For more information see 

http://www.nlpa.org/html/ofaer_program.shtml or contact America’s Clean Water Foundation at 

http://www.acwf.org/projects/ofaer.html for more information on the assessment program and to

download the OFAER environmental assistance program’s Form A: Producer Checklist. 

CAFOs may request compliance assistance from EPA's Agriculture Compliance

Assistance Center. For more information see http://www.epa.gov/agriculture/. 

CAFOs may also contact the state agriculture and environmental agencies for other 

resources. 

7-1
Chapter 7: Avoiding Common Deficiencies 

B. Common Deficiencies 

1. Inadequacy of Storage Capacity 

The minimum storage period for livestock and poultry manures is not specifically defined

by the CAFO regulations. The NRCS recommends that manure storage facilities have a 

minimum of 6 months of storage capacity. As discussed in Chapter 2 of this document, a caseby-case evaluation of the appropriateness of the storage period specified in a NMP based on

the proposed nutrient utilization strategy is necessary for a balanced assessment of other

acceptable storage periods. See Chapter 2 for more information on adequate storage. 

2. Infrequent Dewatering of Storage Structures 

A well-designed manure storage facility must also be well managed to prevent the

development of environmental concerns. Management decisions relative to startup and loading

(especially anaerobic lagoons), manure removal, monitoring of structure integrity and other

issues, and maintenance of appearance and aesthetics play critical roles in a well-managed

storage facilities. Probably the single most important requirement in operating and maintaining

a manure storage facility is to ensure that the facility does not overflow or discharge.

Discharges from manure storage facilities may violate permit requirements and other state or

local regulations; result in large fines or penalties; and, at the very least, represent a potential

environmental hazard. Manure removal from storage according to the storage period selected

is the most critical activity in preventing discharge. Many discharge problems have occurred

because producers were unable to manage the activities necessary to remove manure from

storage in a timely manner. 

3. Pumpdown Practices 

Lagoon effluent and holding pond water is usually removed by pumping equipment

similar to irrigation equipment. Hand carry, solid set, stationary big gun, traveling gun, draghose systems, and center pivot equipment have all been used to land apply liquids. Experience

has shown that unplanned discharges and spills sometimes occur with pumping activities.

Sources of such unplanned discharges include burst or ruptured piping, leaking joints, operation

of loading pumps past the full point of hauling equipment, and other factors. Hence, pumping

activities should be closely monitored, especially in the “startup” phase, to ensure that no spills

or discharges occur. Continuous pumping systems such as drag-hose or irrigation systems can

be equipped with automatic shut-off devices (which usually sense pressure) to minimize the risk

of discharge in the event of pipe failure. In some situations lagoon liquid may be applied

through permanent irrigation systems that are used to apply water for crop production. For this 

type of system backflow/anti-siphon devices should be installed to preclude the chance of

contamination of the fresh water supply. All process wastewater pumped out must be

accounted for in the overall nutrient balance calculated in the CAFO’s NMP. 

4. Lagoon Agitation 

Lagoons may or may not be agitated. When they are not agitated, considerable nutrient

buildup in the bottom sludge will occur. Agitation is a critical operation in maintaining available

storage in liquid manure systems. Some facilities have designed storage structures equipped

with pumps to allow wastewater application without additional agitation. Failure to properly

agitate will likely result in a continuing buildup of settled solids that are not removed. The result 

is less and less available storage capacity as time goes by. 

Agitation of manure resuspends settled solids and ensures that most or all of the manure

will flow to the inlet of the pump or removal device. Additionally, agitation homogenizes the

manure mixture and provides a more consistent nutrient analysis as the manure is being land

applied. Agitation of manure storage facilities releases gases that may increase odor levels and

present a health hazard. Consideration should be given to weather and wind conditions, time of 

7-2
Chapter 7: Avoiding Common Deficiencies 

day, and day of the week to minimize the possibility of odor conflicts while agitating. Some 

CAFOs may be subject to local or state requirements for agitation. 

5. Representative Manure Samples 

It is inappropriate to sample the more dilute liquid from the top of storage facility, and

then agitate the solids during land application activities. If a storage facility will be agitated just

prior to or during land application, manure samples for nutrient analysis, in order to be

considered representative, should be obtained after the facility is well agitated. In most cases, 

the results of such an analysis will not be available before land-applying the manure. In these 

cases, analysis results from the most recent pumping events can be used to anticipate the

present analysis (and estimate the proper application rate). The present analysis, when

available, can be used to calculate the nutrients actually applied. The CAFO must include this 

information in the records and address it in the NMP. 

6. Animal Mortality Practices 

NMPs developed as a condition of an NPDES permit must ensure proper management

of typical and catastrophic animal mortalities, as described earlier in this document. It is 

important for the CAFO also to identify and review any applicable State and local regulations

concerning animal mortalities. In many cases, state or local laws and ordinances may prohibit

the use of specific animal mortality practices. The plan must comply with any state or local

requirements. These regulations can often be found at the State Department of Agriculture of

the State Health Department. The permit authority, as well, should take note of any such State

or local requirements prior to reviewing a NMP as part of a permit application review or

conducting an inspection. 

Potential issues concerning compliance with the requirements for handling animal

mortality include the following: 

C Underestimating the number of mortalities; C Inappropriate technology selection based on type and number of animals; C Incorrect sizing of storage and treatment facilities;

C Failure to address catastrophic mortality; and

C Failure to identify or meet state and local requirements.

7. Chemical Handling 

CAFOs must ensure that chemicals and other contaminants handled on-site are not 

disposed of in any manure, litter, process wastewater, or storm water storage or treatment

system unless specifically designed to treat such chemicals and other contaminants (40 CFR 

122.42(e)(1)). Examples include pesticides, hazardous and toxic chemicals, and petroleum

products/by-products. This standard does not impose any new use restrictions that do not

already exist. Many chemicals will disrupt the biological treatment processes that may be a part

of a CAFO’s waste handling and storage system. Any chemicals that enter manure and

wastewater storage structures could be discharged to surface water during land application of

the manure and wastewater or during spills or other accidental releases. 

In general, poor housekeeping is an indicator of improper storage and handling of

chemicals and an increased potential for contamination of manure and wastewater structures.

The CAFO’s NMP should identify where chemicals are stored, where any mixing and loading

are conducted, how empty containers and waste materials are disposed of, and what practices

are employed to prevent chemicals from inappropriately entering the manure and wastewater 

storage structures. 

In addition, livestock operations may be subject to section 311 of the CWA, which

addresses pollution from oil and hazardous substance releases. The regulations established by

EPA to implement this portion of the CWA have two sets of requirements — the Spill Prevention 

7-3
Chapter 7: Avoiding Common Deficiencies 

Control and Countermeasures (SPCC) plan rule, and the Facility Response Plan (FRP) rule.

Only a very limited number of livestock operations are expected to meet the requirements for

having to prepare an SPCC plan and even fewer would need to prepare an FRP. In those 

cases where the SPCC requirements do apply to a CAFO, it may be appropriate to address

these requirements in concert with the chemical handling minimum standard in the NMP.

Additional information on the SPCC program can be obtained at EPA’s web site at

www.epa.gov/oilspill 

8. Emergency Action Plans 

Behind most manure spills and discharges is a chain of events that leads up to an

unsafe act, improper judgment, unsafe conditions, or a combination of factors. Preventing or

properly responding to discharges on a farm is everyone’s concern. Communication among the

farm owner, supervisors, and employees generates ideas and awareness that leads to accident

prevention and quick response if a spill does occur. Education programs, response plans, and

regular inspections of manure management and application systems are essential links in 

maintaining a safe, accident-free operation. 

Emergency action plans are needed to minimize the environmental impact of manure

spills, discharges, or mishaps. In several states, these plans are required to be developed and

maintained on all livestock and poultry operations, especially those with liquid manure 

management systems. This plan would be implemented if manure or other wastes from an 

operation are leaking, overflowing, or running off the site. Rather than waiting until the manure

or wastewater reaches a stream or leaves the property, act preemptively to ensure that this 

mishap does not happen. 

The Emergency Action Plan should be available to all employees, because accidents,

leaks, and breaks could happen at any time. The plan should follow this format: 

C Eliminate the source;

C Contain the spill, if possible; C Assess the extent of the spill and note any obvious damage; C Contact the appropriate agencies; and

C Clean up the spill and make repairs.

In addition, the CAFO may be required to have a closure plan for their manure storage

structures or impoundments. See Section 4.2 of the Permit Guidance for more information. 

7-4
Chapter 7: Avoiding Common Deficiencies

7-5 

9.	 Example Onsite Check List
Chapter 7: Avoiding Common Deficiencies 

7-6 
Chapter 7: Avoiding Common Deficiencies 

7-7 
Chapter 7: Avoiding Common Deficiencies 

7-8 
Chapter 7: Avoiding Common Deficiencies 

7-9 
Chapter 7: Avoiding Common Deficiencies 

7-10
Chapter 7: Avoiding Common Deficiencies 

7-11
Chapter 7: Avoiding Common Deficiencies 

7-12
Chapter 7: Avoiding Common Deficiencies 

7-13
Chapter 7: Avoiding Common Deficiencies 

7-14
CHAPTER 8: ADDITIONAL RESOURCES ...................................... 8-1

A. USDA Funding Programs for CAFOs ............................... 8-1

B. USDA and EPA Livestock and Poultry Environmental Stewardship

Curriculum .................................................... 8-2

C. EPA Programs and Information ................................... 8-2

D. USDA Programs and Information .................................. 8-4

E. Associations and Trade Groups ................................... 8-5
Chapter 8: Additional Resources 

CHAPTER 8: ADDITIONAL RESOURCES 

A. USDA Funding Programs for CAFOs 

The 2002 Farm Bill offers several voluntary conservation programs that can be used by

livestock and poultry producers to help them comply with the revised CAFO rules. Under the 

1996 Act, a producer who owned or operated a large confined livestock operation was not

eligible for cost-share payments to construct an animal waste management facility. The 2002 

Act removed that prohibition. In addition, the 2002 Act states that 60 percent of the funds made

available for cost-share and incentive payments are to be targeted at practices related to

livestock production rather than the 50 percent that was specified in the1996 Act. NRCS 

provides technical assistance to CAFO operators through conservation planning, design, and

implementation. Producers also may obtain assistance from technical service providers. 

Financial assistance to implement practices and systems is available through the following: 

Environmental Quality Incentives Program (EQIP) provides up to 75 percent (up to 90

percent for beginning or limited resource farmers or ranchers) in cost-share funds to construct

certain conservation practices, such as grassed waterways, filter strips, manure management

facilities, capping abandoned wells, and other practices important to improving and maintaining

the health of natural resources in the area. EQIP funds can be used to develop CNMPs, which

generally will satisfy the CAFO rules nutrient management plan requirement. At least 60 

percent of EQIP financial assistance funds are required by statute to be used on a nationwide

basis for livestock and poultry operations, both confined and grazing. All livestock producers

can receive EQIP cost-share for waste storage facilities regardless of the size of the operation

but only if they implement a CNMP. Each EQIP contract has a payment limitation of $450,000

per individual or entity for the period from fiscal year 2002 - fiscal year 2007. 

USDA’s National Funding Allocation Process is used to distribute program funds to the

States and Territories. The national funding priorities for EQIP under the 2002 Farm Bill are as

follows: 

C Reductions of nonpoint source pollution, such as nutrients, sediment, pesticides,

or excess salinity in impaired watersheds consistent with TMDLs where

available, as well as the reduction of ground water contamination and the

conservation of ground and water resources; 

C Reduction of emissions, such as particulate matter, nitrogen oxides, volatile

organic compounds, and ozone precursors and depleters that contribute to air

quality impairment violations of National Ambient Air Quality Standards; 

C Reduction in soil erosion and sedimentation from unacceptable levels on

agricultural land; and 

C Promotion of at-risk species habitat conservation. 

Local work groups are used by NRCS at the state level to implement these national

priorities. These local work groups–convened by local conservation districts–conduct a

conservation needs assessment and, based on these assessments, develop proposals for

priority areas. These proposals are submitted to the NRCS State Conservationist, who selects

those areas within the state based on the recommendations from the State Technical 

Committee. 

The local work groups are made up of representatives from conservation district board

members and key staff; NRCS; Farm Service Agency (FSA); FSA county committees and key

staffs; the Cooperative State Research, Education, and Extension Service; and other federal,

state, and local agencies interested in natural resource conservation. Their recommendations 

go to the NRCS-designated conservationist for the local area and then to the State

Conservationist, who sets priorities with the advice of the State Technical Committee. The 

8-1
Chapter 8: Additional Resources 

recommendations are integrated into regional and national strategic plans. These strategic

plans provide a basis for funding decisions. 

Agricultural Management Assistance Program (AMA) provides cost-share funds to assist

producers in implementing conservation systems and addressing regulatory requirements. 

Program funds may be used by CAFO operators to develop and implement a CNMP. AMA 

funding is limited to producers in the following 15 states: Connecticut, Delaware, Maine,

Maryland, Massachusetts, Nevada, New Hampshire, New Jersey, New York, Pennsylvania,

Rhode Island, Utah, Vermont, West Virginia, and Wyoming. 

Conservation Reserve Program (CRP) provides participants with rental payments and

cost-share assistance to take agricultural land out of production. Environmentally desirable land

devoted to certain conservation practices including riparian buffers, wetland buffers, and filter

strips may be enrolled in CRP at any time under continuous sign-up. Offers are automatically

accepted provided the land and producer meet certain eligibility requirements. Offers for 

continuous sign-up are not subject to competitive bidding. Continuous sign-up contracts are 10

to 15 years in duration. 

Other Farm Bill Programs: Other conservation programs may support CAFO operators in

their efforts to implement a well-rounded conservation plan. These programs include 

C Conservation Reserve Enhancement Program (CREP); C Wetlands Reserve Program (WRP); and

C Wildlife Habitat Improvement Program (WHIP).

In addition to financial assistance programs under the 2002 Farm Bill, there may be state

and local cost share programs available to support CAFO operators. Permit writers should 

determine whether such programs exist within the state or region for which they are responsible. 

The information presented in this section was obtained from the following USDA Web

site, which summarizes funding opportunities for animal feeding operations:

http://www.nrcs.usda.gov/programs/afo/2003pdf/CAFO%20Rule%20Fact%20Sheet.pdf. 

B. USDA and EPA Livestock and Poultry Environmental Stewardship Curriculum 

The Livestock and Poultry Environmental Stewardship (LPES) curriculum is a nationally

developed and regionally piloted training program. The curriculum was developed by a national

team of more than30 experts from 15 land-grant universities, USDA’s NRCS, and USDA’s

Agricultural Research Service (ARS) who prepared, peer reviewed, and pilot tested the LPES

curriculum with assistance from Mid-West Plan Service (MWPS) and guidance from EPA’s

National Agriculture Compliance Center (Ag Center). The LPES curriculum development effort

was funded by a grant from the EPA’s Ag Center with program oversight through the USDA. 

The goal of the LPES program is to provide producers, industry stakeholders, and educators

with access to the latest science-based information. Instructional materials are available for 

each of the 26 lessons that make up the curriculum. This material can be ordered from the 

MWPS, which is an organization of extension and research agricultural engineers from 12

universities plus representatives of the USDA (http://www.mwpshq.org). 

C. EPA Programs and Information 

Unified National Strategy for Animal Feeding Operations 

U.S. Department of Agriculture/U.S. Environmental Protection Agency Unified National 

Strategy for Animal Feeding Operations, March 9, 1999. 

http://www.epa.gov/npdes/pubs/finafost.pdf 

8-2 
Chapter 8: Additional Resources 

CAFO Final Rule Web Page 

This Web site provides access to the text of the rule and preamble, outreach brochures,

supporting documents, and guidance documents.

http://www.epa.gov/npdes/caforule 

Clean Water Act Section 319 Nonpoint Source Management Program 

EPA Office of Wetlands, Oceans and Watersheds, Clean Water Act Section 319 

http://www.epa.gov/owow/nps/cwact.html 

EMS Resources 

This Web site provides information and resources related to Environmental Management

Systems (EMSs) for businesses, associations, the public, and state and federal

agencies.

http://www.epa.gov/ems 

EPA’s Position Statement on Environmental Management Systems (May 15, 2002) 

http://www.epa.gov/ems/policy/EMS_PositionStatementFinal.pdf 

NPDES Permit Writers’ Manual 

U.S. EPA NPDES Permit Writers’ Manual, EPA 833-B-96-003, December 1, 1996.

To download individual chapters or the entire document, go to EPA’s NPDES Permit

Writers’ Manual page at http://cfpub.epa.gov/npdes/writermanual.cfm?program_id=45.

NPDES Permit Program Basics 

This Web site provides basic permitting tools and information.

http://cfpub.epa.gov/npdes/home.cfm?program_id=45. 

National Agriculture Compliance Assistance Center (Ag Center) 

http://www.epa.gov/agriculture/ 

National Management Measures to Control Nonpoint Source Pollution from

Agriculture 

EPA 841-B-03-004, 2003 

Includes information on the selection and implementation of BMPs to control the

contribution of pollutants to surface water.

http://www.epa.gov/owow/nps/agmm/index.html 

Permit Compliance System 

http://www.epa.gov/compliance/planning/data/water/pcssys.html 

Source Water Protection Programs 

EPA Office of Groundwater and Drinking Water, Source Water Protection

http://www.epa.gov/safewater/protect.html 

TMDL Programs 

EPA Office of Wetlands, Oceans and Watersheds, TMDL Program

http://www.epa.gov/OWOW/tmdl/index.html 

8-3 
Chapter 8: Additional Resources 

USDA and EPA Livestock and Poultry Environmental Stewardship Curriculum 

http://www.lpes.org/ 

United Egg Producers voluntary EMS program 

EPA Project XL, United Egg Producers.

http://www.epa.gov/projectxl/uep/ 

D. USDA Programs and Information 

2002 Farm Bill 

USDA’s online gateway to information about the 2002 Farm Bill.

http://www.usda.gov/farmbill/index.html 

Cooperative Extension Service Agents and Specialists 

Directory of State Extension Service Directors and Administrators.

http://www.reeusda.gov/hrd/statedir.htm 

Land Grant Universities 

This CSREES web site provides directory of land grant universities. Click on a state to 

link to a list of land-grant university web sites.

http://www.reeusda.gov/1700/statepartners/usa.htm 

NRCS Nutrient Management Technical Practice Standard 590 

USDA NRCS Nutrient Management Technical Resources, Code 590.

http://www.nrcs.usda.gov/technical/ECS/nutrient/590.html 

NRCS Nutrient Management Technical Resources 

This Web site provides computer-based tools to facilitate the development and

implementation of NMPs.

http://www.nrcs.usda.gov/technical/nutrient.html 

State NRCS Field Office Technical Guidance 

Click on the map to find available technical guidance for states and counties.

http://www.nrcs.usda.gov/technical/efotg/ 

State Technical Standards for Nutrient Management 

Use these links to NRCS State offices to search for state nutrient management

standards. 

http://www.nrcs.usda.gov/about/organization/regions.html#stat 

Financial & Technical Assistance Available to Concentrated Animal Feeding

Operation Owners and Operators 

Downloadable pdf document from USDA/NRCS (2003).

http://www.nrcs.usda.gov/programs/afo/2003pdf/CAFO%20Rule%20Fact%20Sheet.pdf 

8-4 
Chapter 8: Additional Resources 

USDA Agricultural Research Service 

http://www.ars.usda.gov 

USDA Cooperative State Research, Education, and Extension Service 

http://www.reeusda.gov/ 

USDA Farm Service Agency 

http://www.fsa.usda.gov/ 

USDA Farm Service Agency, Conservation Reserve Program 

http://www.fsa.usda.gov/dafp/cepd/crp.htm 

USDA Farm Service Agency, Conservation Reserve Enhancement Program 

http://www.fsa.usda.gov/dafp/cepd/crep.htm 

USDA Natural Resources Conservation Service (NRCS) 

http://www.nrcs.usda.gov 

USDA NRCS Conservation Programs 

Environmental Quality Incentives Program, Agricultural Management Assistance

Program, Wetlands Reserve Program, Wildlife Habitat Incentives Program. 

http://www.nrcs.usda.gov/programs/ 

USDA NRCS’s CNMP Technical Guidance 

Draft Comprehensive Nutrient Management Planning Technical Guidance, National 

Planning Procedures Handbook, Subpart E, Parts 600.50-600.54 and Subpart F, Part

600.75. 

http://www.nrcs.usda.gov/programs/afo/cnmp_guide_index.html 

USDA National Nutrient Management Policy 

NRCS Online Directives Management System, General Manual, Title 190, Part 402 -

Nutrient Management, May 1999.

http://www.nrcs.usda.gov/technical/ecs/nutrient/gm-190.html 

E. Associations and Trade Groups 

American Society of Agronomy (ASA) 

http://www.agronomy.org/ 

Certified Crop Advisors (CCA) 

http://www.agronomy.org/cca/ 

Certified Professional Agronomists (CPAg) 

http://www.agronomy.org/certification/agronomy.html 

8-5 
Chapter 8: Additional Resources 

Certified Professional Crop Scientists (CPCSc) 

http://www.agronomy.org/certification/crops.html 

Certified Professional Soil Scientists (CPSSc) 

http://www.agronomy.org/certification/soils.html 

ISO 14001 

This Web site provides information on ISO 14001 and other standards from the

International Standards Organization.

http://www.iso.org/iso/en/ISOOnline.frontpage 

National Alliance of Independent Crop Consultants (NAICC) 

http://www.naicc.org/ 

National Association of Conservation Districts (NACD) 

http://www.nacdnet.org 

National Association of State Departments of Agriculture (NASDA) 

http://www.nasda.org 

National Cattleman’s Beef Association (NCBA) 

http://www.beef.org 

National Center for Manure and Animal Waste Management 

http://www.cals.ncsu.edu/waste_mgt/natlcenter/center.htm 

National Milk Producers Federation (NMPF) 

http://www.nmpf.org 

National Pork Producers Council (NPPC) 

http://www.nppc.org 

National Turkey Federation (NTF) 

http://www.turkeyfed.org 

SERA-17 

http://www.soil.ncsu.edu/sera17 

United States Poultry and Egg Association 

http://www.poultryegg.org 

8-6 
APPENDIX A: EFFLUENT LIMITATIONS GUIDELINES AND STANDARDS FOR 

CONCENTRATED ANIMAL FEEDING OPERATIONS 

PART 412—CONCENTRATED ANIMAL FEEDING OPERATIONS (CAFO) POINT SOURCE 

CATEGORY 

Sec.

412.1 General applicability.

412.2 General definitions.

412.3 General pretreatment standards.

412.4 Best management practices (BMPs) for land application of manure.

Subpart A—Horses and Sheep 

412.10 Applicability.

412.12 Effluent limitations attainable by the application of the best practicable control technology currently

available (BPT).

412.13 Effluent limitations attainable by the application of the best available control technology

economically achievable (BAT).

412.15 New source performance standards (NSPS).

Subpart B—Ducks 

412.20 Applicability.

412.21 Special definitions

412.22 Effluent limitations attainable by the application of the best practicable control technology currently

available (BPT).

412.25 New source performance standards (NSPS).

412.26 Pretreatment standards for new sources (PSNS).

Subpart C—Dairy Cows and Cattle Other Than Veal Calves 

412.30 Applicability.

412.31 Specialized definitions.

412.32 Effluent limitations attainable by the application of the best practicable control technology currently

available (BPT).

412.33 Effluent limitations attainable by the application of the best control technology for conventional

pollutants (BCT).

412.34 Effluent limitations attainable by the application of the best available control technology

economically achievable (BAT).

412.35 New source performance standards (NSPS).

412.37 Additional measures.

Subpart D—Swine, Poultry, and Veal Calves 

412.40 Applicability.

412.43 Effluent limitations attainable by the application of the best practicable control technology currently

available (BPT).

412.44 Effluent limitations attainable by the application of the best control technology for conventional

pollutants (BCT).

412.45 Effluent limitations attainable by the application of the best available control technology

economically achievable (BAT).

A-1
412.46 New source performance standards (NSPS). 

412.47 Additional measures. 

Authority: 33 U.S.C. 1311, 1314, 1316, 1317, 1318, 1342, 1361. 

§ 412.1 General applicability. 

This part applies to manure, litter, and/or process wastewater discharges resulting from 

concentrated animal feeding operations (CAFOs). Manufacturing and/or agricultural activities which may 

be subject to this part are generally reported under one or more of the following Standard Industrial 

Classification (SIC) codes: SIC 0211, SIC 0213, SIC 0214, SIC 0241, SIC 0251, SIC 0252, SIC 0253, SIC 

0254, SIC 0259, or SIC 0272 (1987 SIC Manual). 

§ 412.2 General definitions. 

As used in this part: 

(a) The general definitions and abbreviations at 40 CFR part 401 apply.

(b) Animal Feeding Operation (AFO) and Concentrated Animal Feeding Operation (CAFO) are 

defined at 40 CFR 122.23. 

(c) Fecal coliform means the bacterial count (Parameter 1) at 40 CFR 136.3 in Table 1A, which 

also cites the approved methods of analysis. 

(d) Process wastewater means water directly or indirectly used in the operation of the CAFO for 

any or all of the following: spillage or overflow from animal or poultry watering systems; washing, cleaning, 

or flushing pens, barns, manure pits, or other CAFO facilities; direct contact swimming, washing, or spray 

cooling of animals; or dust control. Process wastewater also includes any water which comes into contact 

with any raw materials, products, or byproducts including manure, litter, feed, milk, eggs, or bedding. 

(e) Land application area means land under the control of an AFO owner or operator, whether it is 

owned, rented, or leased, to which manure, litter, or process wastewater from the production area is or 

may be applied. 

(f) New source is defined at 40 CFR 122.2. New source criteria are defined at 40 CFR 122.29(b). 

(g) Overflow means the discharge of manure or process wastewater resulting from the filling of 

wastewater or manure storage structures beyond the point at which no more manure, process wastewater, 

or storm water can be contained by the structure. 

(h) Production area means that part of an AFO that includes the animal confinement area, the 

manure storage area, the raw materials storage area, and the waste containment areas. The animal 

confinement area includes but is not limited to open lots, housed lots, feedlots, confinement houses, stall 

barns, free stall barns, milkrooms, milking centers, cowyards, barnyards, medication pens, walkers, animal 

walkways, and stables. The manure storage area includes but is not limited to lagoons, runoff ponds, 

storage sheds, stockpiles, under house or pit storages, liquid impoundments, static piles, and composting 

piles. The raw materials storage area includes but is not limited to feed silos, silage bunkers, and bedding 

materials. The waste containment area includes but is not limited to settling basins, and areas within 

berms and diversions which separate uncontaminated storm water. Also included in the definition of 

production area is any egg washing or egg processing facility, and any area used in the storage, handling, 

treatment, or disposal of mortalities. 

(i) Ten(10)-year, 24-hour rainfall event, 25-year, 24-hour rainfall event, and 100-year, 24-hour 

rainfall event mean precipitation events with a probable recurrence interval of once in ten years, or twenty 

five years, or one hundred years, respectively, as defined by the National Weather Service in Technical 

Paper No. 40, ‘‘Rainfall Frequency Atlas of the United States,’’ May, 1961, or equivalent regional or State 

rainfall probability information developed from this source. 

(j) Analytical methods. The parameters that are regulated or referenced in this part and listed with 

approved methods of analysis in Table1B at 40 CFR 136.3 are defined as follows: 

(1) Ammonia (as N) means ammonia reported as nitrogen. 

(2) BOD5 means 5-day biochemical oxygen demand. 

(3) Nitrate (as N) means nitrate reported as nitrogen. 

(4) Total dissolved solids means nonfilterable residue. 

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(k) The parameters that are regulated or referenced in this part and listed with approved methods

of analysis in Table 1A at 40 CFR 136.3 are defined as follows: 

(1) Fecal coliform means fecal coliform bacteria. 

(2) Total coliform means all coliform bacteria. 

§ 412.3 General pretreatment standards. 

Any source subject to this part that introduces process wastewater pollutants into a publicly owned 

treatment works (POTW) must comply with 40 CFR part 403. 

§ 412.4 Best management practices (BMPs) for land application of manure, litter, and 

process wastewater. 

(a) Applicability. This section applies to any CAFO subject to subpart C of this part (Dairy and 

Beef Cattle other than Veal Calves) or subpart D of this part (Swine, Poultry, and Veal Calves). 

(b) Specialized definitions. 

(1) Setback means a specified distance from surface waters or potential conduits to surface 

waters where manure, litter, and process wastewater may not be land applied. Examples of conduits to 

surface waters include but are not limited to: open tile line intake structures, sinkholes, and agricultural 

well heads. 

(2) Vegetated buffer means a narrow, permanent strip of dense perennial vegetation established 

parallel to the contours of and perpendicular to the dominant slope of the field for the purposes of slowing 

water runoff, enhancing water infiltration, and minimizing the risk of any potential nutrients or pollutants 

from leaving the field and reaching surface waters. 

(3) Multi-year phosphorus application means phosphorus applied to a field in excess of the crop 

needs for that year. In multi-year phosphorus applications, no additional manure, litter, or process 

wastewater is applied to the same land in subsequent years until the applied phosphorus has been 

removed from the field via harvest and crop removal. 

(c) Requirement to develop and implement best management practices. Each CAFO subject to 

this section that land applies manure, litter, or process wastewater, must do so in accordance with the 

following practices: 

(1) Nutrient management plan. The CAFO must develop and implement a nutrient management 

plan that incorporates the requirements of paragraphs (c)(2) through (c)(5) of this section based on a fieldspecific assessment of the potential for nitrogen and phosphorus transport from the field and that 

addresses the form, source, amount, timing, and method of application of nutrients on each field to 

achieve realistic production goals, while minimizing nitrogen and phosphorus movement to surface waters. 

(2) Determination of application rates. Application rates for manure, litter, and other process 

wastewater applied to land under the ownership or operational control of the CAFO must minimize 

phosphorus and nitrogen transport from the field to surface waters in compliance with the technical 

standards for nutrient management established by the Director. Such technical standards for nutrient 

management shall: 

(i) Include a field-specific assessment of the potential for nitrogen and phosphorus transport from

the field to surface waters, and address the form, source, amount, timing, and method of application of 

nutrients on each field to achieve realistic production goals, while minimizing nitrogen and phosphorus 

movement to surface waters; and 

(ii) Include appropriate flexibilities for any CAFO to implement nutrient management practices to 

comply with the technical standards, including consideration of multi-year phosphorus application on fields 

that do not have a high potential for phosphorus runoff to surface water, phased implementation of 

phosphorus-based nutrient management, and other components, as determined appropriate by the 

Director. 

(3) Manure and soil sampling. Manure must be analyzed a minimum of once annually for nitrogen 

and phosphorus content, and soil analyzed a minimum of once every five years for phosphorus content. 

The results of these analyses are to be used in determining application rates for manure, litter, and other 

process wastewater. 

A-3
(4) Inspect land application equipment for leaks. The operator must periodically inspect equipment 

used for land application of manure, litter, or process wastewater. 

(5) Setback requirements. Unless the CAFO exercises one of the compliance alternatives 

provided for in (c)(5)(i) or (c)(5)(ii) of this section, manure, litter, and process wastewater may not be 

applied closer than 100 feet to any down-gradient surface waters, open tile line intake structures, 

sinkholes, agricultural well heads, or other conduits to surface waters. 

(i) Vegetated buffer compliance alternative. As a compliance alternative, the CAFO may substitute 

the 100-foot setback with a 35-foot wide vegetated buffer where applications of manure, litter, or process 

wastewater are prohibited. 

(ii) Alternative practices compliance alternative. As a compliance alternative, the CAFO may 

demonstrate that a setback or buffer is not necessary because implementation of alternative conservation 

practices or field-specific conditions will provide pollutant reductions equivalent or better than the 

reductions that would be achieved by the 100-foot setback. 

Subpart A—Horses and Sheep 

§ 412.10 Applicability. 

This subpart applies to discharges resulting from the production areas at horse and sheep 

CAFOs. This subpart does not apply to such CAFOs with less than the following capacities: 10,000 sheep 

or 500 horses. 

§ 412.12 Effluent limitations attainable by the application of the best practicable control technology 

currently available (BPT). 

(a) Except as provided in 40 CFR 125.30 through 125.32, and subject to the provisions of 

paragraph (b) of this section, any existing point source subject to this subpart must achieve the following 

effluent limitations representing the application of BPT: There shall be no discharge of process waste 

water pollutants to navigable waters. 

(b) Process waste pollutants in the overflow may be discharged to navigable waters whenever 

rainfall events, either chronic or catastrophic, cause an overflow of process waste water from a facility 

designed, constructed and operated to contain all process generated waste waters plus the runoff from a 

10-year, 24-hour rainfall event for the location of the point source. 

§ 412.13 Effluent limitations attainable by the application of the best available technology 

economically achievable (BAT). 

(a) Except as provided in 40 CFR 125.30 through 125.32 and when the provisions of paragraph

(b) of this section apply, any existing point source subject to this subpart must achieve the following 

effluent limitations representing the application of BAT: There shall be no discharge of process waste 

water pollutants into U.S. waters. 

(b) Whenever rainfall events cause an overflow of process wastewater from a facility designed, 

constructed, operated, and maintained to contain all process-generated wastewaters plus the runoff from 

a 25-year, 24-hour rainfall event at the location of the point source, any process wastewater pollutants in 

the overflow may be discharged into U.S. waters. 

§ 412.15 Standards of performance for new sources (NSPS)

(a) Except as provided in paragraph (b) of this section, any new source subject to this subpart 

must achieve the following performance standards: There must be no discharge of process wastewater 

pollutants into U.S. waters. 

(b) Whenever rainfall events cause an overflow of process wastewater from a facility designed, 

constructed, operated, and maintained to contain all process-generated wastewaters plus the runoff from 

a 25-year, 24-hour rainfall event at the location of the point source, any process wastewater pollutants in 

the overflow may be discharged into U.S. waters. 

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Subpart B—Ducks 

§ 412.20 Applicability. 

This subpart applies to discharges resulting from the production areas at dry lot and wet lot duck 

CAFOs. This subpart does not apply to such CAFOs with less than the following capacities: 5,000 ducks. 

§ 412.21 Special definitions. 

For the purposes of this subpart: 

(a) Dry lot means a facility for growing ducks in confinement with a dry litter floor cover and no 

access to swimming areas. 

(b) Wet lot means a confinement facility for raising ducks which is open to the environment, has a 

small number of sheltered areas, and with open water runs and swimming areas to which ducks have free 

access. 

§ 412.22 Effluent limitations attainable by the application of the best practicable control technology 

currently available (BPT). 

(a) Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this 

subpart shall achieve the following effluent limitations representing the degree of effluent reduction 

attainable by the application of the (BPT): 

Regulated 

parameter 

Maximum daily1 Maximum monthly 

average1 

Maximum daily2 Maximum monthly 

average2 

BOD5 3.66 2.0 1.66 0.91 

Fecal coliform (

3

) (

3

) (

3

) (

3

) 

1 Pounds per 1000 ducks 

2 Kilograms per 1000 ducks 

3 Not to exceed MPN of 400 per 100 ml at any time. 

§ 412.25 New source performance standards (NSPS).

(a) Except as provided in paragraph (b) of this section, any new source subject to this subpart 

must achieve the following performance standards: There must be no discharge of process waste water 

pollutants into U.S. waters. 

(b) Whenever rainfall events cause an overflow of process wastewater from a facility designed, 

constructed, operated, and maintained to contain all process-generated wastewaters plus the runoff from 

a 25-year, 24-hour rainfall event at the location of the point source, any process wastewater pollutants in 

the overflow may be discharged into U.S. waters. 

§ 412.26 Pretreatment standards for new sources (PSNS).

(a) Except as provided in 40 CFR 403.7 and in paragraph (b) of this section, any new source

subject to this subpart must achieve the following performance standards: There must be no discharge of 

process waste water pollutants into a POTW. 

(b) Whenever rainfall events cause an overflow of process wastewater from a facility designed, 

constructed, operated, and maintained to contain all process-generated wastewaters plus the runoff from 

a 25-year, 24-hour rainfall event at the location of the point source, any process wastewater pollutants in 

the overflow may be discharged into U.S. waters. 

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Subpart C—Dairy Cows and Cattle Other Than Veal Calves 

§ 412.30 Applicability. 

This subpart applies to operations defined as concentrated animal feeding operations (CAFOs) 

under 40 CFR 122.23 and includes the following animals: mature dairy cows, either milking or dry; cattle 

other than mature dairy cows or veal calves. Cattle other than mature dairy cows includes but is not limited 

to heifers, steers, and bulls. This subpart does not apply to such CAFOs with less than the following 

capacities: 700 mature dairy cows whether milked or dry; 1,000 cattle other than mature dairy cows or veal 

calves. 

§ 412.31 Effluent limitations attainable by the application of the best practicable control technology 

currently available (BPT). 

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this 

subpart must achieve the following effluent limitations representing the application of BPT: 

(a) For CAFO production areas. Except as provided in paragraphs (a)(1) through (a)(2) of this 

paragraph, there must be no discharge of manure, litter, or process wastewater pollutants into waters of 

the U.S. from the production area. 

(1) Whenever precipitation causes an overflow of manure, litter, or process wastewater, pollutants 

in the overflow may be discharged into U.S. waters provided: 

(i) The production area is designed, constructed, operated and maintained to contain all manure, 

litter, and process wastewater including the runoff and the direct precipitation from a 25-year, 24-hour 

rainfall event; 

(ii) The production area is operated in accordance with the additional measures and records

required by § 412.37(a) and (b). 

(2) Voluntary alternative performance standards. Any CAFO subject to this subpart may request 

the Director to establish NPDES permit effluent limitations based upon site specific alternative 

technologies that achieve a quantity of pollutants discharged from the production area equal to or less 

than the quantity of pollutants that would be discharged under the baseline performance standards as 

provided by paragraph (a)(1) of this section. 

(i) Supporting information. In requesting site-specific effluent limitations to be included in the 

NPDES permit, the CAFO owner or operator must submit a supporting technical analysis and any other 

relevant information and data that would support such site-specific effluent limitations within the time frame 

provided by the Director. The supporting technical analysis must include calculation of the quantity of 

pollutants discharged, on a mass basis where appropriate, based on a site-specific analysis of a system 

designed, constructed, operated, and maintained to contain all manure, litter, and process wastewater, 

including the runoff from a 25-year, 24-hour rainfall event. The technical analysis of the discharge of 

pollutants must include: 

(A) All daily inputs to the storage system, including manure, litter, all process waste waters, direct 

precipitation, and runoff. 

(B) All daily outputs from the storage system, including losses due to evaporation, sludge removal,

and the removal of waste water for use on cropland at the CAFO or transport off site. 

(C) A calculation determining the predicted median annual overflow volume based on a 25-year 

period of actual rainfall data applicable to the site. 

(D) Site-specific pollutant data, including N, P, BOD5, TSS, for the CAFO from representative 

sampling and analysis of all sources of input to the storage system, or other appropriate pollutant data. 

(E) Predicted annual average discharge of pollutants, expressed where appropriate as a mass

discharge on a daily basis (lbs/day), and calculated considering paragraphs (a)(3)(i)(A) through 

(a)(3)(i)(D). 

(ii) The Director has the discretion to request additional information to supplement the supporting 

technical analysis, including inspection of the CAFO. 

(3) The CAFO shall attain the limitations and requirements of this paragraph as of the date of

permit coverage. 

(b) For CAFO land application areas. Discharges from land application areas are subject to the 

following requirements: 

A-6
(1) Develop and implement the best management practices specified in § 412.4;

(2) Maintain the records specified at § 412.37 (c);

(3) The CAFO shall attain the limitations and requirements of this paragraph by December 31,

2006. 

§ 412.32 Effluent limitations attainable by the application of the best conventional pollutant control 

technology (BCT).

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this 

subpart must achieve the following effluent limitations representing the application of BCT: 

(a) For CAFO production areas: the CAFO shall attain the same limitations and requirements as §

412.31(a). 

(b) For CAFO land application areas: the CAFO shall attain the same limitations and requirements 

as § 412.31(b). 

§ 412.33 Effluent limitations attainable by the application of the best available technology 

economically achievable (BAT). 

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this 

subpart must achieve the following effluent limitations representing the application of BAT: 

(a) For CAFO production areas: the CAFO shall attain the same limitations and requirements as §

412.31(a). 

(b) For CAFO land application areas: the CAFO shall attain the same limitations and requirements 

as § 412.31(b). 

§ 412.35 New source performance standards (NSPS).

Any new point source subject to this subpart must achieve the following effluent limitations 

representing the application of NSPS: 

(a) For CAFO production areas. The CAFO shall attain the same limitations and requirements as 

§ 412.31(a)(1) and § 412.31(a)(2). 

(b) For CAFO land application areas: The CAFO shall attain the same limitations and 

requirements as § 412.31(b)(1) and § 412.31(b)(2). 

(c) The CAFO shall attain the limitations and requirements of this paragraph as of the date of

permit coverage. 

(d) Any source subject to this subpart that commenced discharging after [insert date 10 years prior 

to the date that is 60 days from the publication date of the final rule] and prior to [insert date that is 60 days 

from the publication date of the final rule] which was a new source subject to the standards specified in § 

412.15, revised as of July 1, 2002, must continue to achieve those standards for the applicable time period 

specified in 40 CFR 122.29(d)(1). Thereafter, the source must achieve the standards specified in § 

412.31(a) and (b). 

§ 412.37 Additional measures. 

(a) Each CAFO subject to this subpart must implement the following requirements:

(1) Visual inspections. There must be routine visual inspections of the CAFO production area. At a 

minimum, the following must be visually inspected: 

(i) Weekly inspections of all storm water diversion devices, runoff diversion structures, and 

devices channeling contaminated storm water to the wastewater and manure storage and containment 

structure; 

(ii) Daily inspection of water lines, including drinking water or cooling water lines; 

(iii) Weekly inspections of the manure, litter, and process wastewater impoundments; the 

inspection will note the level in liquid impoundments as indicated by the depth marker in paragraph (a)(2) 

of this section. 

(2) Depth marker. All open surface liquid impoundments must have a depth marker which clearly 

indicates the minimum capacity necessary to contain the runoff and direct precipitation of the 25-year, 24-

hour rainfall event, or, in the case of new sources subject to the requirements in § 412.46 of this part, the 

runoff and direct precipitation from a 100-year, 24-hour rainfall event. 

A-7
(3) Corrective actions. Any deficiencies found as a result of these inspections must be corrected 

as soon as possible. 

(4) Mortality handling. Mortalities must not be disposed of in any liquid manure or process 

wastewater system, and must be handled in such a way as to prevent the discharge of pollutants to 

surface water, unless alternative technologies pursuant to § 412.31(a)(2) and approved by the Director are 

designed to handle mortalities. 

(b) Record keeping requirements for the production area. Each CAFO must maintain on-site for a 

period of five years from the date they are created a complete copy of the information required by 40 CFR 

122.21(i)(1) and 40 CFR 122.42(e)(1)(ix) and the records specified in paragraphs (b)(1) through (b)(6) of 

this section. The CAFO must make these records available to the Director and, in an authorized State, the 

Regional Administrator, or his or her designee, for review upon request. 

(1) Records documenting the inspections required under paragraph (a)(1) of this section;

(2) Weekly records of the depth of the manure and process wastewater in the liquid impoundment

as indicated by the depth marker under paragraph (a)(2) of this section; 

(3) Records documenting any actions taken to correct deficiencies required under paragraph

(a)(3) of this section. Deficiencies not corrected within 30 days must be accompanied by an explanation of 

the factors preventing immediate correction; 

(4) Records of mortalities management and practices used by the CAFO to meet the requirements

of paragraph (a)(4) of this section. 

(5) Records documenting the current design of any manure or litter storage structures, including

volume for solids accumulation, design treatment volume, total design volume, and approximate number 

of days of storage capacity; 

(6) Records of the date, time, and estimated volume of any overflow.

(c) Record keeping requirements for the land application areas. Each CAFO must maintain on-site

a copy of its site-specific nutrient management plan. Each CAFO must maintain on-site for a period of five 

years from the date they are created a complete copy of the information required by § 412.4 and 40 CFR 

122.42(e)(1)(ix) and the records specified in paragraphs (c)(1) through (c)(10) of this section. The CAFO 

must make these records available to the Director and, in an authorized State, the Regional Administrator, 

or his or her designee, for review upon request. 

(1) Expected crop yields;

(2) The date(s) manure, litter, or process waste water is applied to each field;

(3) Weather conditions at time of application and for 24 hours prior to and following application; 

(4) Test methods used to sample and analyze manure, litter, process waste water, and soil;

(5) Results from manure, litter, process waste water, and soil sampling;

(6) Explanation of the basis for determining manure application rates, as provided in the technical 

standards established by the Director. 

(7) Calculations showing the total nitrogen and phosphorus to be applied to each field, including 

sources other than manure, litter, or process wastewater; 

(8) Total amount of nitrogen and phosphorus actually applied to each field, including

documentation of calculations for the total amount applied; 

(9) The method used to apply the manure, litter, or process wastewater; 

(10) Date(s) of manure application equipment inspection.

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Subpart D—Swine, Poultry, and Veal Calves 

§ 412.40 Applicability. 

This subpart applies to operations defined as concentrated animal feeding operations (CAFOs) 

under 40 CFR 122.23 and includes the following animals: swine; chickens; turkeys; and veal calves. This 

subpart does not apply to such CAFOs with less than the following capacities: 2,500 swine each weighing 

55 lbs. or more; 10,000 swine each weighing less than 55 lbs.; 30,000 laying hens or broilers if the facility 

uses a liquid manure handling system; 82,000 laying hens if the facility uses other than a liquid manure 

handling system; 125,000 chickens other than laying hens if the facility uses other than a liquid manure 

handling system; 55,000 turkeys; and 1,000 veal calves. 

§ 412.43 Effluent limitations attainable by the application of the best practicable control technology 

currently available (BPT). 

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this 

subpart must achieve the following effluent limitations representing the application of BPT: 

(a) For CAFO production areas. 

(1) The CAFO shall attain the same limitations and requirements as § 412.31(a)(1) through (a)(2).

(2) The CAFO shall attain the limitations and requirements of this paragraph as of the date of

permit coverage. 

(b) For CAFO land application areas. 

(1) The CAFO shall attain the same limitations and requirements as § 412.31(b)(1) and (b)(2).

(2) The CAFO shall attain the limitations and requirements of this paragraph by December 31,

2006. 

§ 412.44 Effluent limitations attainable by the application of the best conventional pollutant control 

technology (BCT). 

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this 

subpart must achieve the following effluent limitations representing the application of BCT: 

(a) For CAFO production areas: the CAFO shall attain the same limitations and requirements as § 

412.43(a). 

(b) For CAFO land application areas: the CAFO shall attain the same limitations and requirements 

as § 412.43(b). 

§ 412.45 Effluent limitations attainable by the application of the best available technology 

economically achievable (BAT). 

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this 

subpart must achieve the following effluent limitations representing the application of BAT: 

(a) For CAFO production areas: the CAFO shall attain the same limitations and requirements as § 

412.43(a). 

(b) For CAFO land application areas: the CAFO shall attain the same limitations and requirements 

as § 412.43(b). 

§ 412.46 New source performance standards (NSPS). 

Any new source subject to this subpart must achieve the following effluent limitations representing 

the application of NSPS: 

(a) For CAFO production areas. There must be no discharge of manure, litter, or process 

wastewater pollutants into waters of the U.S. from the production area, subject to paragraphs (a)(1) 

through (a)(3) of this section. 

(1) Waste management and storage facilities designed, constructed, operated, and maintained to

contain all manure, litter, and process wastewater including the runoff and the direct precipitation from a 

100-year, 24-hour rainfall event and operated in accordance with the additional measures and records 

required by § 412.47(a) and (b), will fulfill the requirements of this section. 

(2) The production area must be operated in accordance with the additional measures required by

§ 412.47(a) and (b). 

A-9
(3) Provisions for upset/bypass, as provided in 40 CFR 122.41(m)-(n), apply to a new source

subject to this provision. 

(b) For CAFO land application areas: the CAFO shall attain the same limitations and requirements 

as § 412.43(b)(1). 

(c) The CAFO shall attain the limitations and requirements of this paragraph as of the date of

permit coverage. 

(d) Voluntary superior environmental performance standards. Any new source CAFO subject to 

this subpart may request the Director to establish alternative NPDES permit limitations based upon a 

demonstration that site-specific innovative technologies will achieve overall environmental performance 

across all media which is equal to or superior to the reductions achieved by baseline standards as 

provided by § 412.46(a). The quantity of pollutants discharged from the production area must be 

accompanied by an equivalent or greater reduction in the quantity of pollutants released to other media 

from the production area (e.g., air emissions from housing and storage) and/or land application areas for 

all manure, litter, and process wastewater at on-site and off-site locations. The comparison of quantity of 

pollutants must be made on a mass basis where appropriate. The Director has the discretion to request 

supporting information to supplement such a request. 

(e) Any source subject to this subpart that commenced discharging after [insert date 10 years prior 

to the date that is 60 days from the publication date of the final rule] and prior to [insert date that is 60 days 

from the publication date of the final rule] which was a new source subject to the standards specified in § 

412.15, revised as of July 1, 2002, must continue to achieve those standards for the applicable time period 

specified in 40 CFR 122.29(d)(1). Thereafter, the source must achieve the standards specified in § 

412.43(a) and (b). 

§ 412.47 Additional measures. 

(a) Each CAFO subject to this subpart must implement the requirements of § 412.37(a).

(b) Each CAFO subject to this subpart must comply with the record-keeping requirements of §

412.37(b). 

(c) Each CAFO subject to this subpart must comply with the record-keeping requirements of §

412.37(c). 

B-1
APPENDIX B - SAMPLE OWNER/OPERATOR INSPECTION CHECKLIST FOR A

LARGE CAFO1 

PRODUCTION AREA 

Conduct visual inspections of: 

‘ Water lines, including drinking water or cooling water lines (daily). 

‘ All storm water diversion devices (weekly). 

‘ Runoff diversion devices (weekly). 

‘ Devices that channel contaminated storm water to the wastewater and manure 

storage and containment structure (weekly). 

‘ Manure, litter, and process wastewater impoundments (weekly). 

‘ The level of the liquid in an open surface liquid impoundment as indicated by a 

depth marker (weekly). 

LAND APPLICATION AREA 

Conduct periodic inspections of: 

‘ The equipment used to land-apply manure, litter, or process wastewater. 

1

This checklist applies to a large CAFO with a capacity equal to or greater than 700 mature dairy 

cows whether milked or dry; 1,000 cattle (other than mature dairy cows and veal calves); 2,500 swine 

each weighing 55 pounds or more; 10,000 swine each weighing less than 55 pounds; 30,000 laying hens 

or broilers if the facility uses a liquid manure handling system; 82,000 laying hens if the facility uses other 

than a liquid manure handling system; 125,000 chickens other than laying hens if the facility uses other 

than a liquid manure handling system; 55,000 turkeys; or 1,000 veal calves. 

C-1 
APPENDIX C - SAMPLE RECORDKEEPING CHECKLIST FOR THE PRODUCTION 

AREA AND LAND APPLICATION AREA AT A LARGE CAFO1 

GENERAL INFORMATION 

Maintain records that contain the following general information for the CAFO: 

‘ The name of the owner or operator of the CAFO. 

‘ The location and mailing address of the CAFO 

‘ The latitude and longitude of the entrance to the production area. 

‘ The number and types of animals confined and whether the animals are in open 

confinement or housed under roofs. 

‘ The type of containment and storage, and the total capacity for manure, litter, and 

process wastewater storage in either gallons or tons. 

‘ The number of acres under the control of the owner or operator available for land 

application of manure, litter, or process wastewater. 

‘ The estimated amount/volume (tons or gallons) of manure, litter, and process 

wastewater transferred to other persons annually. 

‘ Documentation that the applicable effluent limitations guidelines and standards 

have been met. 

PRODUCTION AREA 

Maintain records for the production area that document: 

1

This checklist applies to a large CAFO with a capacity equal to or greater than 700 mature dairy 

cows whether milked or dry; 1,000 cattle (other than mature dairy cows and veal calves); 2,500 swine 

each weighing 55 pounds or more; 10,000 swine each weighing less than 55 pounds; 30,000 laying hens 

or broilers if the facility uses a liquid manure handling system; 82,000 laying hens if the facility uses other 

than a liquid manure handling system; 125,000 chickens other than laying hens if the facility uses other 

than a liquid manure handling system; 55,000 turkeys; or 1,000 veal calves. 

C-1 
‘ The total design volume for manure, litter, or process wastewater storage 

structures and the estimated number of days of storage capacity for each structure. 

‘ The date, time, and estimated volume of any overflow from a manure, litter, or 

process wastewater storage structure. 

‘ The procedures in place to ensure proper operation and maintenance of manure, 

litter, and process wastewater storage structures. 

‘ Proper management of dead animals (i.e., mortalities) to ensure that they are not 

disposed of in a liquid manure, storm water, or process wastewater storage or 

treatment system that is not designed specifically to treat dead animals. 

‘ How clean water is diverted, as appropriate, from the production area. 

‘ How direct contact of confined animals with surface water bodies is prevented. 

‘ How chemicals and other contaminants handled on-site are disposed to ensure 

they are not disposed in any manure, litter, process wastewater, or storm water 

storage or treatment system that is not designed specifically to treat such 

chemicals and other contaminants. 

‘ Results of the daily inspections of water lines, including drinking water or cooling 

water lines. 

‘ Results of the weekly inspections of the storm water diversion devices, runoff 

diversion structures, and devices channeling contaminated storm water to the 

wastewater and manure storage and containment structure. 

‘ Results of the weekly inspections of the manure, litter, and process wastewater 

impoundments. 

‘ Actions taken to correct deficiencies found during the daily and weekly 

inspections. 

‘ Factors that prevented any deficiencies from being corrected within 30 days after 

they were discovered. 

‘ The type of depth marker used in open surface liquid impoundments to indicate 

the minimum capacity needed to contain the runoff and direct precipitation for 

either a 25-year, 24-hour rainfall event or a 100-year, 24-hour rainfall event, 

whichever is appropriate. 

C-2
‘ Results the depth measurements of the manure and process wastewater in an open 

liquid surface impoundment using a depth marker. 

LAND APPLICATION AREA 

Maintain the records for the land application area that document: 

‘ The site-specific nutrient management plan. 

‘ Expected crop yields. 

‘ Date(s) manure, litter, or process waste water was applied to each field. 

‘ Weather conditions at the time of land application and for 24 hours prior to land 

application. 

‘ Test methods used to sample and analyze manure, litter, process waste water, and 

soil. 

‘ Results from manure, litter, process waste water, and soil sampling. 

‘ Explanation of the basis for determining the manure application rates. 

‘ Calculations showing the total nitrogen and phosphorus to be applied to each 

field, including sources other than manure, litter, or process waste water. 

‘ Total amount of nitrogen and phosphorus actually applied to each field. 

‘ Method used to apply the manure, litter, or process waste water. 

‘ Date(s) of manure application equipment inspection. 

C-3 
APPENDIX D - MEASURING THE AMOUNT OF ANIMAL WASTE

Determining the amount of animal waste produced and collected at your farm is essential to successful 

nutrient management. You can estimate the amount of animal waste that is available for land application 

based on the quantity of animal waste collected at cleaning time or by calculating your volume in storage. 

Include animal waste from all sources (e.g., scraped barns, drylots, lagoons, animal waste pits, solid 

separators, calf huts) in your calculation. 

Description 

Estimating the total amount of animal waste in storage is a primary element to determine the amount of 

nutrients you have available, and by extension, the total number of acres that can be fertilized at your 

calibration rate (see Appendix J). To determine your total amount of animal waste, you will need to 

estimate the volume of animal waste in each pile or container. This procedure is described below. 

Instructions for Calculating Animal Waste in Above-Ground Piles 

The volume of your animal waste pile can be calculated by transforming the pile’s shape into a common 

geometric shape, such as a cube or a pyramid. To calculate volume, all you will need to know is the 

formula for the simple shape (see the common volume equations at the end of this appendix) and the 

dimensions of your pile. For example, if you store your animal waste in a rectangular box, then the 

formula to use is: 

Volume = Length * Width * Height 

Next, you will need to measure the box’s length, width, and height (also called depth) and plug these 

numbers into the volume equation. Make sure your measurement units for all dimensions (i.e., sides) are 

consistent. For example, when measuring sides of your container, make sure you consistently measure in 

feet, yards, meters, etc. 

Your animal waste pile will most likely be a complex shape for which a volume formula is not readily 

available; therefore, you cannot use a simple formula to calculate your amount of animal waste. Instead, 

contour and break down the complex pile shape into an imaginary group of simple shapes (e.g., cones, 

rectangular boxes). The volume of each simple shape can then be computed by adding the volumes of all 

of the simple shapes (see the common volume equations at the end of this appendix). Make sure your 

measurement units for all simple shapes are consistent. Two examples of how to simplify a complex 

shape are provided below. 

In Example 1, an animal waste container with an annex becomes two rectangular prisms, each with 

different heights, lengths, and widths. Each volume is calculated separately (length * width * height), and 

then added together to get a total volume. 

D-1
In Example 2, a heaped load on a wagon becomes a rectangular prism and a rectangular pyramid, with 

the top of the rectangular prism in common with the bottom of the pyramid. Each volume is calculated 

separately (see volume equations at the end of this appendix), and then added together to get a total 

volume. 

When prism ends do not form a perfect shape, or where the dimension is not uniform along the end, take 

an average for the dimension when calculating volumes. Sometimes it is necessary to imagine moving 

animal waste around to form a measurable shape. Although this decreases the accuracy of the volume 

calculation, it makes it easier to compute the volume. 

You will probably need to convert your estimated volume of animal waste (in cubic feet or gallons) to units 

that match your animal waste application rates (in gallons or tons per acre). Converting animal waste 

volume to weight requires you to know the bulk density of the animal waste, which you can determine by 

weighing a unit volume of animal waste and dividing the weight by the volume (see Appendix J for more 

details on determining the bulk density of your animal waste). 

Using Example 1 above, you measure your container and find one section of its inside dimensions to be 

12 feet long, 5 feet wide, and 1 feet deep, while the other section is 3 feet long, 5 feet wide, and 0.5 feet 

deep. The total volume is: 

Volume (ft3

) = [(12 ft) x (5 ft) x (1 ft)] + [(3 ft) x (5 ft) x (0.5 ft)] = 67.5 ft3 

Next, determine the bulk density of your animal waste. If your 5-gallon bucket (which has a volume of 2/3 

cubic foot) weighs 5 pounds empty and 37 pounds filled, your density is: 

Density = (37 lb - 5 lb) / (2/3 ft3

) = 48 lb/ft3 

Therefore, your total animal waste in tons is: 

Total Animal Waste (tons) = (67.5 ft3 x 48 lb/ft3)/(2,000 lbs/ton) = 1.62 tons 

Instructions for Calculating Liquid Animal Waste 

Ponds, basins, and pits can be considered inverted piles, and you can therefore use the same techniques 

to estimate volume in above-ground piles. You can also compute the volume using the dimensions of 

your basin or by estimating the amount of animal waste removed after emptying your basin. The following 

example shows how to calculate volume in a basin, assuming the basin is a trapezoidal prism: 

D-2
Volume = (H x [W1 + W2]/2) x L 

Volume = (10 x 20/2) x 20 = 100 x 20 = 2,000 ft3 

If you store your animal waste in a constructed tank, use the dimensions of the tank to calculate volume. 

If the tank is not full, you will need to estimate your “new” height for the tank, that is, how high waste 

comes to in the tank. Use this new height in your volume calculation. 

References 

Cooperative Extension Service, University of Maryland System, Agricultural Engineering Department. 

Manure Management. Outreach & Extension, University of Missouri/Lincoln University. 

Who To Contact For More Information 

Your Local Cooperative Cooperative Extension Office 

Your Local Land Grant University 

National Water Management Center/Natural Resources Conservation Service (USDA) 

D-3
Common Equations for Calculating Volume 

W = Width H = Height L = Length D = Diameter 

Triangular Prism = (W * H) ÷ 2 * L Trapezoid Prism = (H * [W1 + W2] ÷ 2) * L 

2 Circular Prism = 0.785 * D * L Pyramid = W * L * H ÷ 3 

Cone = 0.785 x D2

 * H ÷ 3

 Sphere = 0.524 * D3 

D-4 
APPENDIX E - ANIMAL WASTE SAMPLING

Animal waste analysis is a key component of nutrient management. Complete analyses provide critical 

information about the animal waste composition, including pH and nutrient content. Actual nutrient content 

of animal waste varies with the type of animal, feed, storage system, and method of animal waste 

application. You should sample animal waste stored on site each time it is to be removed (for land 

application on or off site). Sample daily spread operations (if you land-apply daily) several times 

throughout the year to obtain a good estimate of nutrient content. 

Description 

Animal waste sampling is relatively simple, but must be done properly for reliable results. The sampling 

method differs based on the type of animal waste you generate at your farm (e.g., liquid, semi-solid, solid). 

Animal waste sampling generally consists of two to seven steps, depending on the type of animal waste. 

Although the number of steps varies based on the physical state of the animal waste, all of the methods 

rely on collecting a representative animal waste sample for analysis. Where bedding is collected with the 

animal waste, include both bedding and animal waste in the sample. Also, conduct sampling as close to 

the time of land application as possible. Specific techniques for gathering poultry litter, liquid animal 

waste, semi-solid animal waste, and solid animal waste samples are described below; you can use these 

to help develop sampling procedures at your farm. Remember that you should sample and analyze all 

animal waste at your farm. Work with your state and local agricultural Cooperative Extension Offices to 

ensure that you develop the proper procedures for your conditions and animal waste management 

methods. 

Before sampling, know where the samples are to be shipped, how to pack and ship the sample, and what 

to use as sample containers. Many laboratories will furnish the proper sample containers for a small 

charge. Samples should never be collected and shipped in glass bottles, and they should be shipped on 

wet ice unless otherwise instructed by the laboratory. Contact your state or local agricultural Cooperative 

Extension Office for a list of laboratories that can perform your analyses. You should also wear gloves at 

all times, to protect yourself and the sample from contamination. 

The test should analyze for such parameters as percentage of dry matter, ammonium-nitrogen, totalnitrogen, phosphorus (P or P2O5), and potassium (K or K2O). Request results in the same units as your 

calibrated animal waste application system (see Appendix J for more information about calibrating animal 

waste spreaders and irrigators). For example, if your animal waste application is measured in tons per 

acre, request that your analysis be reported as pounds of nutrient per ton of animal waste. 

Instructions for Collecting Poultry Litter Samples 

Poultry litter is a mixture of poultry animal waste and the bedding (e.g., sawdust or rice hull) from houses 

used to raise broilers, turkeys, and other birds. You will need a clean 5-gallon bucket, a narrow, squareended spade (or a soil spade), and a 1-quart plastic freezer bag to collect and store your sample. The five 

steps to collecting a representative poultry litter sample are described below. 

E - 1
Step 1: Mentally divide the poultry house into three zones of equal size. Within each zone, you’ll take six 

cores (i.e., samples) as shown in the diagram below.

 Feed line Water line 

Step 2: Take the first core within 1 foot of the feed line using your spade. Clear a small trench the width of 

the spade to the depth of the litter and remove a 1-inch slice, making sure to get equal amounts of litter 

from all depths. Empty the sample into your bucket. 

Step 3: Repeat the process, gathering six cores from each zone, taking your last core within each zone 

within 1 foot of the water line. Walk the length of the building in each zone in a zigzag pattern taking cores 

with the spade at random points along your path (as shown in the diagram above). Take a representative 

number of cores under feeders and waterers. If the bucket becomes full before all 18 samples are taken, 

dump the contents onto a plastic sheet and continue sampling. 

Step 4: After collecting samples from all three zones, crumble and thoroughly mix all of the litter in the 

bucket. It may be easier to pour the material onto a piece of plastic, or plywood, or into a wheelbarrow to 

facilitate mixing. Thorough mixing is critical to ensure that the analyzed sample is representative of the 

entire house. 

Step 5: After the litter is well mixed, fill your plastic freezer bag with a subsample (i.e., a small sample) 

from your composite. Fill the bag only two-thirds full and squeeze the air out before sealing. Keep the 

sample cool (on ice if possible) until it is shipped. 

Instructions for Collecting Liquid Animal Waste Samples 

Liquid animal waste is typically stored in tanks, lagoons, or ponds. For tanks, collect only one sample, but 

collect several subsamples of liquid animal waste to get a representative sample from lagoons and ponds. 

You will need a clean 5-gallon bucket, a plastic cup, wire, and a long pole to collect liquid animal waste 

samples from lagoons and ponds. Sample containers are required to collect liquid animal waste samples 

from all sources. The two steps to collect a representative liquid animal waste sample are described 

below. 

Step 1: For lagoons and ponds, collect several samples from around the shore of the lagoon or pond and 

mix them together in a clean 5-gallon bucket. You can collect the samples by wiring a plastic cup to the 

end of a long pole. When taking the sample, turn the cup upside down and push it a few feet below the 

surface. Then turn the cup right side up and pull out the sample. 

If you store your liquid waste in tanks, your tanks must be well agitated before sampling. Often the only 

practical time to do this is as you are pumping the animal waste into your spreader. 

Step 2: Fill a sample container with your sample, making sure to leave 2 inches of air space. Tightly seal 

the container and keep cool (on ice if possible) until it is shipped. 

E - 2
Instructions for Collecting Semi-Solid Animal Waste Samples 

Collecting a representative sample of semi-solid animal waste is best done using a simple sampling 

device. You will need a 2-inch PVC pipe, nylon rope, a rubber ball, a dowel, a clean 5-gallon bucket, and 

sample containers. The seven steps to collecting a representative semi-solid animal waste sample are 

described below. 

Step 1: Get a length of 2-inch PVC pipe long enough to reach well into your animal waste storage facility. 

Cut a notch 2 inches long and 1/4 inch wide at one end of the pipe. Cut a length of nylon rope 2 feet 

longer than the PVC pipe and tie a knot at one end. Drill a hole through a 2.5 inch rubber ball. Thread the 

rope through the ball until it is snug against the end knot. Tie a second knot to hold the ball at the end of 

the rope. Thread the rope through the PVC pipe and pull it until the ball plugs the end of the pipe. Slip 

your end of the rope into the notch and tie a knot; this will create a “latch” to keep the pipe sealed after you 

collect the sample. Tie a short dowel to the free end of the rope to serve as a hand grip. Cut a length of 

1-inch PVC pipe and seal one end. Use this pipe to push samples out of the tube. 

Step 2: With the ball sealing the end of the pipe, push the pipe through the top layer of animal waste to 

form a sample hole. 

Step 3: Release the rope from the notch so that the ball dangles freely from the end of the pipe. Push the 

pipe into the sample hole in the animal waste crust. Make sure the ball does not block the pipe opening. 

Step 4: Ease the pipe back slightly and pull the rope until the ball seals the end of the pipe. Slip the rope 

in the notch to anchor the ball in place and withdraw the pipe. 

Step 5: Pour the sample into a clean 5-gallon bucket. You may need the 1-inch PVC pipe to force the 

sample from the pipe. Two people will need to operate a long pipe. To avoid backwash, keep the bottom 

of the pipe lower than your end. 

Step 6: Repeat this process at several locations around the pit. 

Step 7: Mix samples thoroughly in the bucket, then fill your sample container with the mix, leaving 2 inches 

of air space. Tightly seal the container and keep the sample cool (on ice if possible) until it is shipped. 

A diagram of the sampling apparatus is shown below. 

Instructions for Collecting Solid Animal waste 

Collecting a representative sample of solid animal waste is best done using a simple sampling device. 

You will need thin-walled metal tubing (1-inch diameter), a drill, a dowel or short metal rod, a clean 5-

gallon bucket, and sample containers. The four steps to collecting a representative solid animal waste 

sample are described below. 

Step 1: Cut a 3-foot length of thin-walled metal tubing and sharpen the bottom edge. Near one end, drill 

E - 3
through the tubing and slide in a dowel or short metal rod to make a handle. Cut a 4-foot length of 

broomstick to force samples from the tube. 

Step 2: Push and twist the tubing all of the way into the animal waste pile. Use the broomstick to push the 

animal waste into a clean 5-gallon bucket. 

Step 3: Repeat Step 2 at several random locations around the pile. It is recommended that the more 

samples the better, so try to get at least 20 samples. 

Step 4: Mix samples in the 5-gallon bucket, and fill the sample container with the mix, leaving 2 inches of 

air space. Tightly seal the container and keep the sample cool (on ice if possible) until it is shipped. 

Animal Waste Sample Analyses 

Contact your state or local agricultural Cooperative Extension Office for a list of available laboratories that 

can analyze your animal waste samples. Some Cooperative Extension Offices may even provide free 

analysis (e.g., in Maryland). 

Label, package, and ship your samples to your contracted laboratory. The laboratory should be able to 

provide their proper protocol for packaging and shipping samples. 

Your animal waste sample is typically analyzed for the following constituents: 

C Nitrogen;

C Phosphorus;

C Potassium;

C pH;

C Moisture content;

C Calcium;

C Manganese;

C Magnesium;

C Sulfur;

C Zinc; and

C Copper.

The first step in interpreting analytical results of an animal waste test is to check the units used to report 

the results. They may be reported as percent nutrient (%) or parts per million (ppm), or, on rare 

occasions, on a dry-weight basis. (Most animal waste is measured on a wet-weight [i.e., as-is] basis.) 

The phosphorus and potassium may be reported on an elemental basis (P and K) rather than the 

phosphate (P2O5) and potash (K2O) basis, which is typical of fertilizers. You will need to convert your 

animal waste test results into the proper fertilizer units for calculating your animal waste application rate. 

Animal waste is an excellent fertilizer if it is spread uniformly on a field and at the proper rate. A pound of 

animal waste phosphate or potash has a nutrient value equivalent to that of commercial fertilizer. 

Although it has a value as a fertilizer, typically 50 to 80% of the total nitrogen applied is available to crops. 

E - 4
References 

MU Extension, University of Missouri-Columbia. Sampling Poultry Litter for Nutrient Testing. 

Cooperative Extension Service, University of Maryland System. Manure Analysis Instruction Sheets. 

Who to Contact For More Information 

Your Local Cooperative Cooperative Extension Office 

Your Local Land Grant University 

National Water Management Center/Natural Resources Conservation Service (USDA) 

E - 5
APPENDIX F - SOIL SAMPLING AND TESTING

The nutrient status of the soil is one of the most important components of a nutrient management plan. A 

soil test is a laboratory procedure that measures the plant-available portion of soil nutrients. This 

measurement is used to predict the amount of nutrient or nutrients that will be available during the growing 

season. Soil test results form the basis for nutrient recommendations. Traditional soil tests include tests for 

pH, phosphorus, potassium, nitrogen, soil organic matter, and electrical conductivity. You should sample 

each field area where animal waste nutrients are to be applied. If different field areas have different soil 

types, past cropping histories, or different production potentials, you should sample and manage these 

areas separately. You can use soil test results to characterize soil conditions and to determine the 

agronomic nutrient application rate (see Appendix I) for animal waste application. 

Description 

Soil sampling determines the average nutrient concentration in a field, and allows you to measure nutrient 

variability in the field. When you know the variability, you can adjust the fertilizer application rates to more 

closely meet the supplemental nutrient needs of a crop, which can increase crop yield, reduce commercial 

fertilizer costs, and reduce environmental risk. 

Send all samples to an accredited laboratory for analyses. An accredited laboratory is one that has been 

accepted in one or more of the following programs: 

C State-certified programs;

C The North American Proficiency Testing Program (Soil Science Society of America); and

C Laboratories participating in other programs whose tests are accepted by the Land Grant

University in the state in which the tests are used as the basis for nutrient application. 

The analytical results from a soil test extraction are relatively meaningless by themselves. You and/or your 

Certified Nutrient Management Specialist must interpret soil nutrient levels in terms of the soil's ability to 

supply the nutrients to crops. Most soil test laboratories use qualitative terms such as "low," "medium or 

optimum," and "high or very high," which are related to quantities of nutrients extracted, to label the 

results. 

Soil testing is a chemical evaluation of the nutrient-supplying capability of a soil at the time of sampling. 

Poor soil-sampling procedures account for more than 90% of all errors in fertilizer recommendations 

based on soil tests. The test is only as good as the sample, so you must handle the sample properly for it 

to remain a good sample. A testing program can be divided into four steps: 1) taking the sample, 2) 

analyzing the sample, 3) interpreting the sample analyses, and 4) making the fertilizer recommendations. 

Take samples as close as possible to planting or to the time of crop need for the nutrient, approximately 

two to four weeks before planting or fertilizing the crop. It usually takes one to three weeks from the time 

you sample for you to receive the results. Very wet, very dry, or frozen soils will not affect results, but 

obtaining samples during these climatic conditions is very difficult. Do not sample snow-covered fields 

because the snow makes it difficult to recognize. Avoid unusual areas in the field because your sample 

may not be representative. 

You may need to sample once every year and fertilize for the potential yield of the intended crop, 

especially for mobile nutrients. Whether you need an analysis of a nutrient depends on such things as 

mobility in the soil and the nutrient requirements of the crop. Having an analysis performed for every 

nutrient each year is not necessary, although EPA requires that, at a minimum, Large CAFOs should 

sample soil at least once every five years. 

F-1
Collect soil samples from each field at least once during each crop rotation cycle, keeping a record of the 

results for each field to evaluate long-term trends in nutrient levels. Work with your state and local 

agricultural Cooperative Extension Office to ensure that you develop the best procedures for your 

conditions and animal waste management methods. 

Instructions for Collecting Soil Samples 

Below is a set of sampling instructions that you can use to help you develop sampling procedures at your 

farm. You will need a soil auger or probe (a shovel or spade can be used for shallow samples), a ruler, 

several 5-gallon buckets for compositing samples, some plastic sheeting, and soil collection bags. Be 

sure all of your equipment is clean so as not to contaminate any of your samples. 

Avoid unusual areas such as eroded sections, dead furrows, and fence lines when sampling. If your 

sample area contains various topography, subdivide it into relatively uniform areas (i.e., sampling units). 

Omit small units from sampling since they are probably not treated differently from adjacent units. 

Sampling units should be approximately 20 acres in area, though some units may be bigger and some 

smaller. 

Number of Subsamples 

Collect one sample for each sample unit. (Note that if you collect samples at different depths, such as for 

nitrogen samples, you will have more than one sample per unit; you will have one sample, per depth, per 

unit.) Within each sampling unit, take soil samples from several different locations (at the same depth) 

and mix these subsamples into one composite sample for the unit for a given depth. The number of 

subsamples you take depends on the size of the unit. You can use the chart below as guidance. 

Field Size (acres) Number of Subsamples 

Fewer than 5 15 

5 to 10 18 

10 to 25 20 

25 to 50 25 

More than 50 30 

Source: Soil Sampling, University of Idaho. 

If you sample several units, this guidance may be impractical and unrealistic because of the time required 

to take the recommended samples. You need to collect a minimum of 10 subsamples from each unit to 

obtain a representative sample. Your composite sample for the unit should be at least 1 pint in size 

(approximately 1 pound). 

This guidance is also more applicable to surface (i.e., tillage layer) samples. If you take samples at 

greater depths, take at least 10 or more subsamples at a given depth at random within the sampling unit. 

F-2
Sampling Depth 

The depth at which you should sample depends on your crop, cultural practices, tillage depth, and 

nutrients to be analyzed. You need surface soil samples for all crops because fertilizer recommendation 

for all nutrients (except nitrogen) are based on the crop and soil tests from the surface samples. Typically, 

surface samples are used for determining pH, lime need, organic matter, phosphorus, potassium, sulfur, 

and zinc. The tillage layer is considered to be the 0-to-6- or 0-to-8-inch depth. Sampling deeper than the 

tillage layer for these parameters can result in inaccurate results. 

When sampling for mobile nutrients such as nitrogen and boron, take samples by 1-foot increments to the 

effective rooting depth of the crop, which may be 5 to 6 feet for some crops. Therefore, you will have five 

or six composite samples for the sampling unit (not including your surface sample). Effective rooting 

depth for some common crops are listed below. You will need subsurface soil samples for these nutrients 

because they leach into the subsoil. Collect these samples separately from your surface samples. 

Crop Depth (feet) 

Cereals (wheat, barley, oats) 5 to 6 

Corn 5 to 6 

Alfalfa, rapeseed 4 to 5 

Hops, grapes, tree fruits 4 to 5 

Sugarbeets 2 to 3 

Peas, beans, lentils, onions, 2 

potatoes, mint 

Vegetable seed 1 to 1.5 

Source: Soil Sampling, University of Idaho. 

Sample Collection 

Collect the appropriate number (at the appropriate depth) of samples in your bucket, one unit at a time. 

Take all subsamples randomly from the unit, ensuring that you are getting a representative distribution of 

samples. Zig-zag through the unit, staying away from the unusual areas as described above. Scrape 

away any surface residues and mix the sample to break up the soil aggregates. After you have collected 

all of your subsamples, stir your composite at least 50 times and spread out the sample on a piece of 

plastic or plywood. Fill your soil bag with 1 pint of soil per unit, discarding the rest of the soil from the unit. 

Repeat the collection process for each unit and for each depth. 

Sampling Handling 

Keep moist soil samples cool at all times during and after sampling. Samples can be refrigerated or 

frozen for extended periods of time. If samples cannot be refrigerated or frozen soon after collection, airdry them or take them directly to the testing laboratory. Air-dry by spreading the entire sample from a 

given unit in a thin layer on a plastic sheet, breaking up any clumps, and spreading the soil in a layer 

about 0.25 inch deep. Dry at room temperature, using a fan (if available) for more rapid drying. When the 

soil samples are dry, again mix the soil thoroughly, breaking up any large clumps. Take about 1 pint of 

well-mixed soil from the sample and place it in a soil sample bag or other container. When sending 

samples to your laboratory, be sure to include which nutrients you want to have analyzed, your last crop 

grown, and future cropping plans. 

F-3
Interpreting results 

Soil-testing laboratories use different test methods, which may influence results and subsequent 

recommended agronomic nutrient application rates. Adequate soil nutrient levels vary depending on plant 

species. Soil test results can be grouped into broad categories that describe the relative crop availability 

for a given nutrient: low, medium, optimum, and excessive. These categories are described below. 

C Low: The nutrient content in the soil is inadequate for optimum growth. Additional 

nutrients are needed for optimal crop growth. 

C Medium: The nutrient content in the soil may or may not be optimum for growth. 

Additional nutrients may be needed for optimal crop growth. 

C Optimum: The nutrient content in the soil is adequate for optimum growth of most crops. 

Additional nutrients may not be needed for optimal crop growth. 

C Excessive: The nutrient content in the soil is more than adequate for optimum growth of 

most crops. No additional nutrients should added. Additional nutrients may cause excess 

nutrient leaching or eroding from crop fields into water bodies. 

References 

Cooperative Extension, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln. 

Guidelines for Soil Sampling. G91-1000-A, February 1991. 

Mahler, R.L., and T.A. Tindall. “Soil Sampling,” Bulletin 704 (Revised). University of Idaho, Cooperative 

Extension System, August 1997. 

Maryland Cooperative Extension, University of Maryland College Park/Eastern Shore. Soil Sampling 

Procedures for Nutrient Management. March 1999. 

Oregon State University Extension Service. Soil Test Interpretation Guide, EC 1478, August 1999. 

Who to Contact for More Information 

Your Local Cooperative Cooperative Extension Office 

Your Local Land Grant University 

National Water Management Center/Natural Resources Conservation Service (USDA) 

F-4
APPENDIX G - LEACHING INDEX 

Tools such as the Soil Nitrogen Leaching Index have been developed to assist field staff, watershed 

planners, and land users in evaluating various land forms and management practices for potential risk of 

nitrogen and phosphorus movement to water bodies. The vulnerability ratings of the Leaching Index (i.e., 

inches of water infiltrating below the 1- meter root zone) address the ability of soluble nitrogen to move 

below the crop root zone and into groundwater. 

informational purposes only. 

nutrient management planner. 

Description 

seasonal rainfall distribution. The LI 

It does 

occurring if nutrients are present and available to leach. 

Instructions for Calculating Your Leaching Index 

calculate it using the following equations: 

where: 

The material contained in this appendix should be used for your 

Specific leaching index calculations should be done by NRCS, your local extension, or a certified 

The Leaching Index (LI) is a simple index of potential leaching based on average annual percolation and 

It is important in determining the amount of nitrate nitrogen leached. 

considers the saturated hydraulic conductivity and storage capacity of individual soils (based on various 

regions of the country), the average annual rainfall, and the seasonal distribution of that rainfall. 

not look at the leaching potential of specific nutrients, but rather the intrinsic probability of leaching 

The LI for local areas is in the USDA/NRCS Field Office Technical Guide (FOTG), Section II-3, or you can 

where: 

p = annual precipitation 

s = (1,000/curve number) - 10 

G-1
where: 

PW = fall and winter precipitation when crop growth is minimal, usually the sum of 

precipitation during October, November, December, January, and February 

An LI below 2 inches would indicate that soluble nitrogen would likely not leach below the root zone, 

whereas an LI between 2 and 10 inches indicates that soluble nitrogen may leach below that zone. You 

should consider nutrient management practices and techniques, such as pre-sidedress nitrate nitrogen 

testing (which measures soil nitrate during the growing season rather than prior to it) and use of a 

nitrification inhibitor. 

An LI greater than 10 inches indicates that soluble nitrogen leaches below the root zone. You should use 

an intense nitrogen management plan to minimize nitrate nitrogen movement. This would include careful 

management of applied nitrogen, precise timing to match crop utilization, conservation practices that 

restrict water percolation and leaching, and covering crops to capture and retain nutrients in the upper soil 

profile. 

References 

USDA/NRCS Field Office Technical Guide. 

Core4 Conservation Practices, August 1999. 

Who to Contact for More Information 

Your Local Cooperative Cooperative Extension Office 

Your Local Land Grant University 

National Water Management Center/Natural Resources Conservation Service (USDA) 

G-2
Appendix H - 1

APPENDIX H - THE PHOSPHORUS INDEX: A PHOSPHORUS RISK ASSESSMENT 

TOOL

RATIONALE FOR A PHOSPHORUS INDEX

Agronomic soil test P levels and guidelines were developed to guide soil fertility 

management by approximating the pool of soil P available for crop growth. Specifically, 

agronomic soil test P interpretations (i.e., low, medium, optimum, high) are based on the 

expected response of a crop to P, and cannot be directly interpreted as estimates of 

environmental risk, such as runoff P enrichment potential. Recent research shows that when 

soils have not received recent additions of P from manure and/or fertilizer soil test P is strongly 

related to dissolved P in runoff. However, in typical U.S. agricultural systems, which rely on the 

use of organic and inorganic nutrient sources, agronomic soil test guidelines alone are inadequate 

to address water quality concerns associated with nutrient loss. 

In considering alternatives to using agronomic soil test P guidelines alone to manage 

environmental quality, it is necessary to examine how nutrients, in this case P, move from the 

landscape to water. Within agricultural watersheds most nutrients, including P, are exported 

from a small part of the landscape during a few relatively large storms. This indicates that 

specific areas, known as hydrologically active areas, are responsible for a majority of P transport. 

These areas are not evenly distributed across the landscape and are typically determined by 

physical landscape properties such as soil type and topography. Where hydrologically active 

areas coincide with areas of high soil P or recent P applications, there is increased vulnerability 

and concern about P loss. These vulnerable areas or “critical P source areas” occur even in 

regions where subsurface flow pathways dominate P transport (e.g., some areas of the Coastal 

Plains). In these regions, critical P source areas contribute P to drainage waters and are localized 

to soils with high soil P saturation and hydrologic connectivity to the surface drainage network. 

In order to effectively manage nutrient related water quality concerns, these critical P source 

areas must be identified and managed. The identification of these areas needs to incorporate 

agronomic soil test P guidelines, but must also examine P application and P transport. 
Appendix H - 2

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The P Index has been developed to assist field staff, watershed planners, and land users in 

evaluating various landscapes and management practices for potential risk of P movement to 

water bodies through the identification of critical P source areas. The Index is a simple 

qualitative assessment tool to rank site vulnerability to P loss, which can also be used to help 

identify agricultural areas or management practices that have the greatest potential to accelerate 

eutrophication. As such, the P Index will identify alternative management options available to 

land users, providing flexibility in developing remedial strategies. When the parameters of the 

Index are analyzed, it becomes apparent that an individual parameter or parameters can influence 

the Index disproportionately. These identified parameters can the basis for planning corrective 

soil and water conservation practices and management techniques. As a result, some general 

management recommendations can be given based on site vulnerability rating, however, P 

management is very site-specific and requires a well-planned, coordinated effort between 

farmers, extension agronomists, and soil conservation specialists. Ultimately, the P Index is an 

educational tool that brings interaction between the planner and farmer in assessing 

environmental management decisions required to improve the farming system on a watershed 

rather than political basis. 

The P Index identifies critical P source areas or areas vulnerable to P loss by accounting for 

and ranking source and transport factors controlling P loss from a given site. Source and site 

management factors are typically well defined and reflect land use patterns related to soil P 

status, mineral fertilizer and manure P inputs, and tillage. Source factors include soil test P and 

rate method, timing and form of P applied. Transport factors mobilize P sources, creating 

pathways of P loss from a field or watershed and include erosion, surface runoff, subsurface 

flow, distance of the field to stream, presence of channelized flow pathways or ditches, and 

existence of implemented Best Management Practices. 

The material contained in this appendix should be used for your informational 

purposes only. Specific P Index calculations should be completed by NRCS, 

your local extension, or a certified nutrient management planner. 
Appendix H - 3

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Source Factors

Soil Test P Level 

Definition: 

A soil sample from the site is necessary to assess the level of "available P" in the surface 

layer of the soil. The available P is the level customarily given in a soil test analysis by 

the Cooperative Extension Service or commercial soil test laboratories. The user of the P 

Index must determine the soil test P level present at the site using a current soil test 

report. The soil test level for "available P" does not ascertain the total P in the surface 

soil. However, it does provide an indication of the amount of total P that may be present 

because of the general relationship between the forms of P (organic, adsorbed, and labile 

P) and the solution P available for crop uptake. 

Where this information can be located: 

Soil test P levels can be taken directly from a soil test report. Be sure to follow state or 

region specific soil sampling guidelines and use sampling depths recommended for the 

production system, an accredited soil testing lab, and a soil analysis recommended for the 

region and relevant soil types. 

Fertilizer and Organic Source P Application Rate 

Definition: 

The P fertilizer or organic P application rate is the amount, in pounds of phosphate per 

acre (lb P2O5/acre), that is applied to the soil. Fertilizer and organic P source accounting 

in P Indices varies by state. Most commonly, there are separate categories for rates of 

fertilizer and organic P sources and the actual rate is entered into the P Index. However, 

there are Indices that combine fertilizer and organic P source rates and others that do not 

require an actual rate entry, but that assign a category to a range of P application rates. 

Therefore, carefully review the P Index being used and the associated guidance. 
Appendix H - 4

Where this information can be located: 

Generally, the application rate of commercial fertilizer and organic sources of P can be 

taken directly from the farm records or nutrient management plan. In calculating the 

organic source P content, an analysis of the organic material or accredited book value 

estimate is needed. The P content by analysis is generally considered to be completely 

plant available. 

Fertilizer and Organic Source P Application Method 

Definition: 

The manner in which P is applied from a fertilizer or organic P sources and the amount of 

time that the fertilizer is exposed on the soil surface until crop utilization effects potential 

P movement. The value categories of increasing severity, LOW to VERY HIGH, depict 

the longer surface exposure time between fertilizer application, incorporation, and crop 

utilization. 

Where this information can be located: 

Generally, the application rate of commercial fertilizer can be taken directly from the 

farm records or nutrient management plan. 

Organic P Source Availability 

Definition: 

While the P content of organic sources is considered to be completely plant available, it is 

not considered to be completely environmentally available. Therefore, several P Indices 

account for the environmental availability of P in organic sources. Typically, a book 

value is assigned based on manure type. 

Where this information can be located: 
Appendix H - 5

Manure type is indicated in the farm nutrient management plan or the farm records. 

Additionally, the availability book values are typically located in the state specific P 

Index guidance. 

Transport Factors 

Soil Erosion 

Definition: 

Soil erosion is defined as the loss of soil along the slope or unsheltered distance caused 

by the processes of water and wind. Soil erosion is estimated from erosion prediction 

models currently used (USLE or RUSLE for water erosion and WEQ for wind erosion; 

http://www.iwr.msu.edu/rusle/ & http://bioengr.ag.utk.edu/rusle2/). Erosion induced by 

irrigation is calculated by other convenient methods. These soil loss prediction models 

do not predict sediment transport and delivery to a water body. The prediction models 

are used in the P Index to indicate a movement of soil, thus potential for sediment and 

attached phosphorus movement across the slope or unsheltered distance and toward a 

water body. 

Where this information can be located: 

The soil loss values will need to be determined for each evaluated field based on current 

farm management practices. In some states, the actual erosion values are available in the 

farm’s soil conservation plan. 

Index Surface Runoff Class or Runoff Class 

Definition: 

The runoff class of the site can be determined from soil survey or NASIS data (National 

Soil Information System). Guidance in determining the runoff class is based on the soil 

saturated hydraulic conductivity (KSat) and the percent slope of the site (U.S. Department 

of Agriculture-Natural Resources Conservation Service, 1993). A more simplified table 

has been developed using soil permeability classes. The result of using the matrix 

relating soil permeability class or KSat and slope provides the value categories: 
Appendix H - 6

NEGLIGIBLE, VERY LOW, LOW, MEDIUM, HIGH, and VERY HIGH. Another 

method to determine runoff class is using the NRCS curve number (CN) method. The 

major factors that determine curve number incl the hydrologic soil group, landscape 

cover type, conservation treatment, hydrologic condition, and antecedent runoff 

conditions. The NRCS runoff curve number method is described in detail in (U.S. 

Department of Agriculture-Natural Resources Conservation Service, 1985). 

Where this information can be located: 

Runoff class values can be determined using NASIS or soil survey data and the 

conversion table for the chosen evaluation method. Standardized state runoff class tables 

may be developed in cooperation with the state NRCS agency using NASIS data. 

Sub-surface Movement 

Definition: 

Sub-surface P movement refers to P movement down through the soil profile that has the 

potential to reach a receiving body. This type of P movement is accounted for based on 

either the leaching potential of the soil or based on the presence of artificial drainage. 

Leaching potentials are generally based on soil type and P Indices will provide 

information sources or a table to determine the leaching potential for their Index. The 

presence of artificial drainage typically depends on the examination of farm records or a 

field inspection. 

Where this information can be located: 

Sub-surface drainage information requires either knowledge of the soil type or presence 

of artificial drainage. This can be located in the farm records, soil survey information, or 

NASIS data. 

Distance to Receiving Body of Water 

Definition: 
Appendix H - 7

Distance to a receiving water body is a P Index category that has more recently been 

added to P Index evaluations. The distance category is used to estimate the potential of P 

reaching a body of water based on the concept that the closer a field is to a body of water 

the more likely it is that P in or on that field will reach a body of water. While the 

concept underlying the use of a distance factor is consistent from state to state, the 

methods used in determining the distance categories and the field reference point used in 

the measurement of a distance to a body of water varies from state to state. 

Where this information can be located: 

The distance of field to a receiving body of water can be obtained from a field inspection 

and measurement or by calculation of the distance using a farm map. In the 

determination of the distance, it is necessary to be familiar with the guidance associated 

with the P Index approach that you are using as different states use different field 

reference points (i.e., edge of field or concentrated flow path) in determining the distance. 

P Index Procedure 

To conduct a P Index evaluation of a field it is necessary to obtain all of the information 

needed to determine the source and transport characteristics. If one were using the Pennsylvania 

P Index (Table 1) to conduct the assessment, the following information would be needed: 

• Soil test 

• Fertilizer rates, methods, and timing of application 

• Manure rates, methods, and timing of application and P availability 

• Erosion 

• Runoff potential 

• Subsurface drainage 

• Contributing distance 

• Modified Connectivity – Practices such as buffer zones that impact the potential of P 

to move from a field to a body of water. 
Appendix H - 8

The information is used to determine all of the source and transport factors in the 

Pennsylvania P Index either using a directly measured value or selecting a category and 

weighting factor. Source and transport factors are then calculated using the equations listed 

below. The final P Index value is calculated by multiplying the Source Factor by the Transport 

Factor and then multiplying the product by 2. The final P Index value is then used to determine 

the appropriate management guidance for the field (Table 2). 

Source Factor = Soil Test Rating + Fertilizer Rating + Manure Rating 

Transport Factor = ((Soil Erosion + Runoff Potential + Sub-Surface Drainage + 

Contributing Distance)/22) x Modified Connectivity 

P Index Value = Source Factor x Transport Factor x 2 

Once the final P Index value has been calculated, there are two choices available to the 

producer and nutrient management plan developer: (1) follow the recommended nutrient 

management guidance (Table 2) or (2) examine best management practices that could be 

implemented to reduce both vulnerability to P loss from the site as well as the P Index value. 

Best management practices may include, but are not limited to the following: soil conservation 

practices, modification of organic and inorganic P application timing and incorporation, animal 

diet modification, and installation of buffer zones. The use of best management practices as a 

part of the P Indexing process offers producers flexibility in managing their manure on-farm 

while environmental protection. It is important to note that the initial P Index evaluation in 

many states, including Pennsylvania, accounts for the presence of certain best management 

practices. 

Interpretations of Site Vulnerability Rating for the P Index 

The guidance and P Index rating categories below in Table 2 were originally outlined in 

the USDA-USEPA Unified National Strategy and have been directly adopted by most states. 

The Low and Medium categories prescribed N-based nutrient management and High or Very 

High categories prescribe P-based management. Despite consistency in the management 

recommendations, differences can be seen the numeric P Index value categories that define Low, 

Medium, High, and Very High. 
Appendix H - 9

LOW - This site has a LOW potential for P movement from the site. If farming practices are 

maintained at current level, the probability of an adverse impact to surface water resources from 

P losses from this site would be low. 

MEDIUM - This site has a MEDIUM potential for P movement from the site. The probability 

for an adverse impact to surface water resources is greater than that from a LOW vulnerability 

rated site. Some remedial action should be taken to lessen the probability of P movement. 

HIGH - This site has a HIGH potential for P movement from the site. There is a high 

probability for an adverse impact to surface water resources unless remedial action is taken. Soil 

and water conservation as well as phosphorus management practices are necessary to reduce the 

risk of P movement and probable water quality degradation. 

VERY HIGH - This site has a VERY HIGH potential for P movement from the site. The 

probability for an adverse impact to surface water resources is very high. Remedial action is 

required to reduce the risk of P movement. All necessary soil and water conservation practices 

plus a phosphorus management plan must be put in place to reduce the potential of water quality 

degradation. 
Appendix H - 10

For more information contact: 

Andrew Sharpley, USDA-ARS, Pasture Systems and Watershed Management Research Unit, 

Curtin Road, University Park, PA 16802-3702. Phone (814) 863-0948; Email - 

Andrew.Sharpley@ars.usda.gov

Jennifer Weld, USDA-ARS, Pasture Systems and Watershed Management Research Unit, 

Curtin Road, University Park, PA 16802-3702. Phone – (814) 863-0946; Email - 

Jennifer.Weld@ars.usda.gov

Jerry Lemunyon, USDA-NRCS, Resource Assessment Division, South Regional Center, 501 

West Felix, P.O. Box 6567, Fort Worth, TX 76115. Phone – (817) 509 3216; Email - 

jlemunyo@ftw.nrcs.usda.gov

RRReeefffeeerrreeennnccceeesss

U.S. Department of Agriculture-Natural Resources Conservation Service. 1985. National 

Engineering Handbook number 4. 

U.S. Department of Agriculture-Natural Resources Conservation Service. 1993. Soil Survey 

Manual, Agricultural Handbook 18. 

Weld, J.L., D. Beegle, W.J. Gbuerk, P.J.A. Kleinman, and A.N. Sharpley. 2003. The 

Pennsylvania phosphorus index: Version 1. CAT UC 180 5M3/03ps4591. Publications 

distribution center, Pennsylvania State University, University Park, PA. 
Table 1. The Pennsylvania Phosphorus Index: Version 1 (Weld et al., 2003) 

PART A – SCREENING TOOL 

 Evaluation Category 

Soil Test P > 200 mg P kg-1 

 Contributing Distance < 150 ft 

If yes to either factor 

then proceed to Part B

PART B - SOURCE FACTORS 

Soil test Soil Test P (mg P kg-1) 

 Soil Test P Rating = 0.20* Soil Test P (mg P kg-1) 

Fertilizer P rate Fertilizer P (lb P2O5/acre) 

Manure P rate Manure P (lb P2O5/acre) 

P source 

application 

method 

0.2 

Placed or injected 

2" or more deep 

0.4 

Incorporated <1 

week 

0.6 

Incorporated > 1 week 

or not incorporated 

April - October 

0.8 

Incorporated >1 week 

or not incorporated 

Nov. - March 

1.0 

Surface applied to 

frozen or snow 

covered soil 

 Fertilizer Rating = Rate x Method 

P source 

availability 

0.5 

Treated manure/Biosolids 

0.8 

Dairy 

1.0 

Poultry/Swine 

 Manure Rating = Rate x Method x Source Availability Coefficient 

Source Factor = Soil Test P Rating + Fertilizer Rating + Manure Rating 

PART C - TRANSPORT FACTORS

Erosion Soil Loss (ton/acre/yr) 

Runoff potential 0 

Very low 

 2 

Low 

 4 

Medium 

 6 

High 

 8 

Very high 

Sub-surface 

drainage 

 0 

None 

 1 

Some 

 2* 

Patterned 

Contributing 

distance 

 0 

> 500 ft. 

 2 

500 to 350 ft. 

 4 

350 to 250 ft. 

 6 

150 to 250 ft. 

 8 

< 150 ft. 

Transport Sum = Erosion + Runoff Potential + Sub-surface Drainage + Contributing Distance

Modified 

connectivity 

0.7 

Riparian buffer– applies to 

distance < 150 ft 

1.0 

Grassed waterway or none 

1.1 

Direct connection – applies to 

distance > 150 ft 

Transport Factor = Modified Connectivity x (Transport Sum / 22) 

* Or rapid permeability soil near a stream 

Phosphorus Index Value = 2 x Source Factor x Transport Factor 
H-12

Appendix H - 12

Table 2. The Pennsylvania Phosphorus Index: Version 1 Interpretations and Management 

Guidance (Weld et al., 2003). 

Value Rating Management Guidance 

0 to 59 Low 

Nutrients can be applied to meet the Nitrogen crop requirement. 

Low potential for P loss. Maintenance of current farming practices is recommended to 

minimize the risk of adverse impacts on surface waters 

60 to 79 Medium 

Nutrients can be applied to meet the Nitrogen crop requirement. 

Medium potential for P loss. The chance for adverse impacts on surface waters exists. 

An assessment of current farm nutrient management and conservation practices is 

recommended to minimize the risk of future P losses. 

80 to 99 High 

Nutrients can be applied to meet the Phosphorus crop removal. 

High potential for P loss and adverse impacts on surface waters. Soil and water 

conservation measures and P-based management plans are needed to minimize the risk 

of P loss. 

100 or 

greater Very High 

No Phosphorus can be applied. 

Very high potential for P loss and adverse impacts on surface waters. Conservation 

measures and a P-based management plan must be implemented to minimize the P 

loss. 
APPENDIX I - AGRONOMIC NUTRIENT APPLICATION RATE

Good nutrient management includes proper land application of animal wastes. To do this, determine the 

most appropriate rate at which your animal waste should be applied. Calculate this application rate using 

results from your soil and animal waste analyses, crop nutrient recommendations, and land availability. It 

is important to consider all of these factors when calculating your nutrient application rate to reduce 

commercial fertilizer costs, reduce potential for crop damage, and reduce environmental impact. 

Description 

Animal waste nutrient application rates should be based upon Land Grant University guidance and sitespecific test results. You should consider current soil test results, nutrient credits from previous legume 

crops and animal waste applications, crop yield goals, and other pertinent information when determining 

your nutrient balance, which is used to calculate your application rate. 

Base your application rate on realistic yield goals. You can calculate an appropriate application rate, or 

agronomic rate, using the nutrient availability of the animal waste and the crop requirement for the nutrient 

having the highest nutrient need (nitrogen or phosphorus). Most state guidelines/policies allow animal 

waste applications at rates sufficient to meet, but not to exceed the nitrogen needs of agronomic crops, 

which typically results in over application of phosphorus. However, in areas with high soil phosphorus 

levels, animal waste should be applied at rates sufficient to meet, but not to exceed the phosphorus needs 

of agronomic crops. 

To calculate your nutrient application rate you need to perform a nutrient balance to determine whether 

animal waste nutrient spreading is necessary. To do this, first determine your crop nutrient needs, 

accounting for the nutrients currently available in your soil (as determined in your soil analyses) and from 

nitrogen credits. Next, determine how many gallons (or tons) of animal waste you collect between each 

land application (see Appendix D for more information on estimating animal waste volumes). Then, using 

the results of your nutrient animal waste analysis (see Appendix E), calculate the amount of nutrients 

available each year from your animal waste. Now you can calculate the amount of animal waste needed 

to meet your nutrient needs, which is done by dividing your crop nutrient need by your nutrient animal 

waste analysis for a few key nutrients (e.g., nitrogen and phosphorus). These steps are described in more 

detail below. 

Performing A Nutrient Balance 

To determine your agronomic nutrient application rate, you need to perform a nutrient balance for your 

crops. The nutrient balance accounts three components needed to calculate an application rate: 1) the 

nutrients your crops need, 2) the nutrients available to your crops from prior nutrient applications (i.e., 

nutrient credits), and 3) the nutrients available from your animal waste. 

Most crop nutrient requirements and nutrient credits are calculated from many years of field research. 

There is no “real time” method available for calculating your crops’ nutrient requirement or the nutrients 

available at any one time. Rather, both components are based on past performance for your climate and 

soil condition. 

A nutrient budget is a method for matching the nutrient needs of your crop with your available nutrients. It 

can easily determine if there is a gross imbalance between the nutrients that are available and the amount 

required and can be used to calculate a nutrient addition rate. 

There are two methods for calculating a nutrient budget. The first is based on a soil test analysis and crop 

nutrient recommendation as given by an agronomic specialist (e.g., USDA, land grant university). The 

I-1
nutrient requirement of your crop is determined from historical field research for your soil and climate. The 

nutrient credits are derived from analysis of soil and historical animal waste spreading data. This method 

is EPA’s preferred method because it takes into account your local climate and soil conditions. Typical 

crop nutrient requirements can be obtained from USDA and state agricultural Cooperative Extension 

Offices. Some states have even developed agronomic plant nutrient recommendations based on soil tests 

and yield goals for the major agronomic crops grown in that state. 

The second method is based on the balance between nutrients supplied to the crop and nutrients removed 

by the crop. You need to know the crop for which you are planning a nutrient budget. Nutrient budgets 

can be calculated for a single crop or over the entire crop rotation. You need to know your expected crop 

yield based on realistic soil, climate, and management parameters. Yield expectations can be calculated 

from historical records, soil productivity tables, or local research. 

Estimating the Nutrients Removed by the Crop 

The nutrients removed by the crop can be used to represent your nutrient crop need when it is not 

available from other sources. When a crop is harvested and removed from the field, the nutrients in that 

crop are also removed. These removed nutrients represent a net loss to the soil. Other losses, such as 

erosion and runoff, and leaching can occur and must be estimated if you are trying to maintain a constant 

level of nutrients in your field. The USDA/NRCS Agricultural Waste Management Field Handbook, Table 

6-6, can be used to estimate nutrient content in harvested crops. This handbook can be found on the 

Internet at http://www.ftw.nrcs.usda.gov/awmfh.html. Chapter 11 of this handbook can be used to 

estimate nitrogen nutrient losses from the field system. Use the following form to calculate the nutrients 

removed by your crop. 

Step 1: Yield (units of measure/acre) * Unit weight (lbs) = pounds crop material harvested 

______________________ * _____________ = _______________ lb/acre 

Step 2: Nutrient content of harvested material (refer to Table 6-6 of the Agricultural Waste Management Field 

Handbook) 

% N = ________ % P = _________ % K = ________ 

Step 3: Crop nutrient Content (multiply results in Step 1 by results in Step 2) 

N = _____ lb/acre * ______ %N P = _____ lb/acre * _____%P K = _____lb/acre * _____%K 

N = _______lb/acre P = ________ lb/acre K = _______ lb/acre 

Step 4: Convert to fertilizer equivalent units 

N =N lb/acre P2O5 = P lb/acre * 2.29 K2O = K lb/acre * 1.2 

N = ______ lb/acre P2O5 = ______ lb/acre K2O = ______ lb/acre 

Source: Core4 Conservation Practices, August 1999. 

I-2 
Estimating Nitrogen Credits 

Nitrogen is a mobile nutrient and exists in the soil and plants in many forms. It is stored in the soil’s 

organic matter and released as the organic matter decomposes. This nitrogen is available to crops during 

this time and should be accounted for in performing your nutrient balance. There are at least four groups 

of nitrogen credits that you need to account for: 1) legume nitrogen credits from your previous crop, 2) 

residual nitrogen from previous manure applications, 3) irrigation water nitrate nitrogen, and 4) other 

sources. These are described below. 

C Legume Nitrogen Credits - Legumes can produce, through atmospheric fixation, enough 

nitrogen to meet their nutrient requirements. When the legume is harvested, organic 

nitrogen is mineralized, releasing available nitrogen to the following crop. Refer to your 

local extension information for the legume nitrogen credits. 

C Nitrogen residual from previous manure applications - Organic nitrogen mineralizes 

according to a decay series which is specific for each manure type and composition. This 

concept recognizes the gradual mineralization of organic nitrogen over several years. 

Refer to your local mineralization rates to determine the residual release of nitrogen. 

C Irrigation Water Nitrate Nitrogen - Irrigation water, especially from shallow aquifers, 

contain some nitrogen in the form of nitrate nitrogen. To calculate the amount of nitrogen 

applied with irrigation water, determine the concentration of nitrate nitrogen in water (in 

mg/L). The application amount will equal the nitrate nitrogen concentration multiplied by 

the volume (in acre-inches) times 0.23 to calculate pounds of nitrate per acre. 

C Other Nitrogen Credits - Other credits come from atmospheric deposition from dust and 

ammonia in rainwater. This value is recorded by weather stations and can obtained from 

the National Atmospheric Deposition in Fort Collins, Colorado. The atmospheric 

deposition can range from a few pounds per acre per year to over 30 pounds per acre per 

year. 

Use the following chart to calculate your nitrogen credits. 

A. Legumes Credits from Previous Crop _____ lb/acre 

B. Residual from Previous Animal Waste Applications _____ lb/acre 

C. Irrigation Water Nitrate Nitrogen _____ lb/acre 

D. Others (atmospheric deposition, other fertilizer applications) _____ lb/acre 

Total Nitrogen Credits (Sum of A through D) _____ lb/acre 

I-3 
Calculating the Number of Pounds of Each Nutrient Available During Land Application 

To calculate the number of pounds of each nutrient that is available during land application, you need to 

know how much animal waste you produce (see Appendix D) and the nutrients contained in it (see 

Appendix E). Using your animal waste sampling results, multiply the amount of animal waste in storage 

(or available for application) by the concentration of nutrients found in your animal waste, as shown below. 

Nutrient 

Amount of Animal 

waste Available 

(gal or tons) 

Concentration of 

Nutrient in Animal 

waste Analysis 

(lb/gal or lb/ton) 

Pounds of Nutrient 

Available 

Nitrogen x = 

Phosphorus 

(P2O5) 

x = 

Potassium (K2O) x = 

Source: Iowa State University, 1995. 

After calculating the pounds of nutrients available, you need to correct for the nitrogen that is lost to the air 

during application. (It is assumed that there are no losses of phosphorus or potassium during application.) 

The remaining amount is the amount of nitrogen that will remain after spreading. To do this, multiply your 

pounds of nitrogen available (from the above chart) by the correction factor below that best describes your 

animal waste application method, and then plug that factor into the following form. 

C Direct injection - 0.95

C Broadcast and incorporate within 24 hours - 0.95

C Broadcast and incorporate after 24 hours - 0.8

C Broadcast, no incorporation - 0.7

If you use a combination of application methods, you will need to account for this difference in the total 

pounds of nitrogen available, using the appropriate ratio of pounds available with the appropriate 

correction factor. 

Pounds of Nitrogen 

Available 

Correction Factor Nitrogen Remaining after 

Application Loss (lbs) 

x = 

Source: Iowa State University, 1995 

The result is the nitrogen remaining after application losses; however, only 50 to 80% of the organic 

nitrogen will be available to plants the first year after spreading. The percentage available depends on the 

type of animal waste spread. Beef and dairy animal waste has approximately 50% available, while poultry 

waste has approximately 80% available. Next, multiply your nitrogen amount by your factor (e.g., 0.50 or 

0.80) using the following chart. The result is the net usable nitrogen in your animal waste (in pounds). 

I-4
Pounds of Nitrogen 

Remaining after 

Application Loss 

Percent of Nitrogen 

Available (as a 

decimal) 

Net Usable Nitrogen 

in Animal Waste (lbs) 

x = 

Source: Iowa State University, 1995 

Account for the nitrogen credits by adding the total estimated nitrogen credits to the net usable nitrogen in 

animal waste to calculate the total nitrogen available sources. 

To calculate the usable amount of each nutrient available during application, divide the total usable 

amount of nutrient in animal waste (using the adjusted amount for nitrogen) by your available volume of 

animal waste, to calculate a rate in pounds of nutrient per gallon of animal waste, or pounds of nutrient per 

ton of animal waste. 

Instructions for Determining Animal Waste Volume to Apply 

After calculating your nutrient needs, total pounds of nutrients available and the pounds of nutrients 

available to plants in each gallon (or ton) of animal waste spread, you have determined your nutrient 

balance and can calculate the amount of animal waste to apply to your crops. For each nutrient, divide 

your net nutrient needs (calculated or estimated from published rates) by the usable nutrient amount 

available (in pounds per gallon or pounds per ton) to calculate the amount of animal waste you need to 

apply. Do this for both nitrogen and phosphorus. You will base your application rate on whichever 

nutrient requires less animal waste. Next, divide your total volume of animal waste needed by your land 

area (in acres) to calculate your animal waste application rate (in gallons per acre or tons per acre). 

References 

U.S. Department of Agriculture. CORE4 Key Conservation Practices, August 1999. 

Iowa State University, University Extension. Land Application for Effective Manure Nutrient Management, 

Pm-1599, October 1995. 

Wolkowski, Richard P. A Step-by-Step Guide to Nutrient Management. Nutrient and Pest Management 

Program, A3568. 

Who to Contact for More Information 

Your Local Cooperative Cooperative Extension Office 

Your Local Land Grant University 

National Water Management Center/Natural Resources Conservation Service (USDA) 

I-5
APPENDIX J - CALIBRATING ANIMAL WASTE SPREADERS AND IRRIGATORS 

Animal waste should always be applied uniformly and at a rate consistent with nutrient demand. Although 

many equipment options exist, there are basically three general methods of application: subsurface 

application, irrigation, and surface application. The method of application, however, is generally dictated 

by the form of the animal waste (i.e., solid, semi-solid, liquid). For example, solid animal waste is 

generally best applied using a surface spreader or subsurface system. Liquid animal waste is applied by 

pump and liquid spreader, subsurface, or irrigation system. Semi-solid animal waste can be handled as a 

solid or a liquid; therefore, it can be applied with a surface spreader, liquid spreader, subsurface, or 

irrigation system. This appendix discusses calibration techniques for surface application, subsurface 

application, and irrigation. 

Description 

Animal waste spreader calibration is a key component of nutrient management. To properly calibrate your 

system, you will need to know your animal waste application rate (see Appendix I). 

You can perform animal waste spreader calibration using two direct methods: load-area and weight-area. 

Both methods require measuring the amount of animal waste applied to the soil under different conditions. 

The load-area method involves measuring the amount of animal waste in a loaded spreader and then 

calculating the number of spreader loads required to cover a known land area. Subsurface application 

calibration should be done using the load-area method because soil-injected animal waste cannot be 

collected. The weight-area method requires weighing animal waste spread over a small surface and 

computing the quantity of animal waste applied per acre. You can measure the application rates for 

irrigation systems using the area of your liquid storage. 

Animal waste should be collected after spreading, if possible. If calibrating using a large tarp or plastic 

sheet, then you can easily recollect the test volume. If the animal waste is spread on a known area, such 

as 500 or 1000 ft3

, this should be done in a field were the animal waste can be left on the surface. 

Your calibration method used depends on the type of animal waste spreader used (e.g., liquid animal 

waste is best measured with the load-area method, while solid or semi-solid animal waste may be used 

with either method). Instructions for using load-area calibration and weight-area calibration, as well as for 

calculating irrigation rates from irrigation systems are provided below. 

Instructions for Load-Area Calibration (Solid, Semi-solid, or Liquid Animal Waste) 

Use this method when you know your animal waste spreader’s capacity or animal waste weight. This 

approach works well with a liquid spreader filled to capacity, and is less accurate for box spreaders or 

other solid application systems where capacity is difficult to estimate. 

Overview 

1. Measure the capacity of animal waste (tons or gallons) held in the spreader load. 

2. Spread a number of identical loads at a constant speed, spreader setting, and overlap. 

3. Measure the total area of the spread. 

4. Compute the amount of animal waste spread per acre. 

J-1 
Measure the capacity of animal waste (tons or gallons) held in the spreader load. 

The capacity must be expressed in units compatible with the units used in the nutrient analysis and 

recommended application rate. The capacity is sometimes provided by the equipment manufacturer. 

Liquid animal waste application is expressed in pounds of nutrient per gallon; the application rate is given 

in gallons per acre. Spreader capacity is given in gallons of animal waste. 

Solid and semi-solid animal waste application is expressed in pounds of nutrient per ton; the application 

rate is given in tons per acre. Spreader capacity is given in tons of animal waste. Note that the moisture 

content in animal waste affects the weight. Therefore, the weight capacity of the spreader varies based on 

the animal waste held. The most accurate method of determining the weight of a load is to actually 

measure the load using farm scales. 

If scales are not available, use the following steps to convert volumetric capacity to weight capacity: 

C The manufacturer should supply the volumetric capacity of the spreader in cubic feet. 

Two capacities are usually provided: heaped load (animal waste piled higher than the 

sides of the box) and struck load (the volume contained within the box). 

C	 The capacity of older spreaders is sometimes given in bushels; multiply the bushel 

capacity by 1.24 to determine capacity in cubic feet. 

C Next, multiply the volumetric capacity (in cubic feet) by the bulk density of the animal 

waste (in pounds per cubic foot) and convert it to tons by dividing by 2,000. 

C Bulk density depends on the amount of water, solids, and air in the animal waste and can 

be measured by weighing a known standard volume of animal waste. A 5-gallon bucket 

has a volume of two-thirds cubic foot and can be used as a standard volume by weighing 

an empty bucket and recording the weight, filling the bucket with animal waste from the 

loaded spreader (packed to the same density as in the spreader), weighing the full bucket, 

and subtracting the empty bucket weight to calculate the animal waste weight in pounds. 

Next, multiply the animal waste weight by 3, and then divide by 2 to calculate the animal 

waste bulk density in pounds per cubic foot of volume. 

C Multiply the bulk density by the spreader capacity (in cubic feet) to calculate the weight of 

the spreader load in pounds, and then divide by 2,000 to calculate tons. 

C Repeat this procedure at least three times, sampling the animal waste at different places 

and in different spreader loads. 

C Average the results to obtain a representative composite of the animal waste. 

Spread a number of identical loads at a constant speed, spreader setting, and overlap. 

Spread at least three full loads of animal waste on the field, maintaining the same speed and spreader 

setting for each load. Try to spread in a rectangle or square for easy calculation. 

Measure the total area of the spread. 

Place flags at the four corners of the spread area. Measure the width and length between the flags (in 

feet) using a measuring tape, wheel, or consistent pace. Multiply the width by the length and divide that 

product by 43,560 to determine the area in acres. 

J-2
Compute the amount of animal waste spread per acre. 

Multiply the number of loads spread by the number of tons (or gallons) per load to determine the total 

amount of animal waste applied to the area. Divide the total amount of animal waste by the area of the 

spread (in acres) to determine the application rate in tons per acre (or gallons per acre). 

Repeat this procedure for various speeds and spreader settings until the desired application rate is 

achieved, maintaining a record of the rates found at the different settings. This procedure needs to be 

repeated for each piece of equipment used to spread animal waste. 

Instructions for Weight-Area Calibration (Solid or Semi-solid Animal Waste) 

Use this method to estimate solid and semi-solid animal waste application rates. 

Overview 

1. Select a animal waste collection surface. 

2. Secure the collection surface in the field. 

3. Spread animal waste over the collection area. 

4. Collect and weigh the animal waste. 

5. Compute the application rate. 

Select a animal waste collection surface. 

Select a ground cover that can be used to collect the animal waste. The ground cover can be a cloth or 

plastic sheet of at least 100 square feet in area. Multiply the length of the sheet by the width to determine 

the area in square feet. If the animal waste is too liquid, use shallow plastic or metal pans on top of the 

ground cover, with a minimum area of 1 square foot each. Multiply the pan length by the width to calculate 

the area of one pan. Multiply the area of the one pan by the number of pans to determine the total 

collection area in square feet. For handling and cleaning convenience, place a plastic garbage bag inside 

the pan for each field test so that the bag and animal waste can be discarded, leaving the pan clean. Six 

or more pans are necessary for a test. 

Weigh the ground cover or one pan and record the weights for use as a tare weight in calculations. You 

can use dirty sheets and pans for multiple tests only after removing major animal waste deposits. Weight 

dirty sheets and pans before each test so that any animal waste residue is included in the new tare weight. 

Secure the collection surface in the field. 

Lay out the ground cover, fully extended. Lay the sheet on the ground so that, as the sheet is removed 

from the field, the animal waste applied over the surface can be collected easily in its folds. If dirty sheets 

are being used for additional test, turn the dirty side up so that any animal waste residue included in the 

tare weight is not lost. Use stone, metal, or earth clods to hold down the cover so that the wind does not 

disturb it. Evenly space pans in a row perpendicular to the spreader’s path. Be mindful of tires, as they 

can easily crush the pans. Place flags at designated wheel tracks to help avoid pan damage. 

J-3
Spread animal waste over collection area. 

Spread animal waste over and near the ground cover or pans in a pattern similar to that practiced during 

spreading. With rear outlet spreaders, make three passes: the first directly over the center of the 

collection area and the second two on each side of and overlapping the first pass. With side outlet 

spreaders, locate a first pass off of but along one edge of the collection area. Continue with subsequent 

passes farther away from the collection area and at the intended overlap until animal waste no longer 

reaches the surface. 

In all cases, start spreading animal waste far enough before the collection area to ensure that the 

spreader is functioning. If a ground cover is folded or a pan is moved during a spread pass, investigate its 

condition before continuing with the test. Folded edges can be straightened without major loss of 

accuracy. If more than one-fourth of the surface has moved and did not receive animal waste, conduct the 

test again with a newly weighed sheet. 

Collect and weigh the animal waste. 

Remove the weights holding the ground cover in place. Fold the cover and animal waste in short sections 

from all sides and corners inward, avoiding animal waste loss. A 100-square-foot sheet folded with wet 

animal waste may weigh as much as 150 pounds and can be difficult to handle; place the folded cover in a 

feed tub or other container for easier handling. Pans typically weigh less than 5 pounds each and are 

usually easier to handle. 

Select scales that can accurately weigh the type and quantity of animal waste collected (e.g., kitchen 

scales for pans, spring-tension milk scales, or platform balances for ground covers). The weight indicated 

on the scale includes the tare weight of the cover or pans. Subtract the tare weight from the indicated 

weight to determine the net weight of the animal waste collected. 

Compute the application rate. 

The application rate is based on the method of collection and the units per acre. 

Using a ground cover: Divide the net pounds of animal waste collected by the ground cover area to obtain 

the animal waste application rate in pounds of animal waste per square foot. Multiply that result by 43,560 

and then divide by 2,000 to convert to tons per acre. 

Using pans: Add the net weights of the animal waste collected in the individual pans to calculate the total 

animal waste weight collected. Divide the total animal waste weight by the total collection area to obtain 

pounds of animal waste per square foot. Multiply that result by 43,560 and then divide by 2,000 to convert 

to tons per acre. 

If working with liquid animal waste, make an additional measurement to calculate the weight per gallon of 

animal waste. Fill a 5-gallon bucket with liquid animal waste similar to that tested. Weigh the bucket of 

animal waste and subtract the tare weight of the bucket to determine the net weight of 5 gallons of animal 

waste. Divide the result by 5 to determine the weight in pounds per gallon. Multiply this weight by the 

number of pans collected. Divide the total animal waste weight by the total collection area to obtain 

pounds of animal waste per square foot. Multiply that result by 43,560 and then divide by pounds per 

gallon to convert to gallons per acre. 

J-4
Instructions for Irrigation System Calibration 

Use this method when a direct measure of volume is not available when pumping from a lagoon or animal 

waste storage. Different methods are used depending on whether you use a traveling gun irrigation 

system or center pivot irrigation system. Both methods are described below. 

Measure surface area of lagoon or storage 

Calculate the area (assumed to be a rectangle) by multiplying length (in feet) by width (in feet) to calculate 

the surface area in square feet. Take these measures at the liquid level and not at the top of the storage. 

Secure a yardstick or other measuring tool to a wooden stake, and plant the stake in the storage where 

the wastewater is several feet deep. Start your irrigation system. 

If using a traveling gun irrigation system: 

Note the starting location of the towed irrigation system and at the same time the liquid level in the storage 

tank on the yardstick (to the nearest quarter inch). Mark the irrigation nozzle location with a stake; this is 

considered Depth 1. Record results in inches. 

Measure the diameter of the wetted circle from the irrigation nozzle (in feet). It is best if this measure is 

perpendicular to the direction of travel. 

At some later time (at least an hour), note the liquid level in the storage tank again, generally after more 

than one foot change in depth has occurred. (The greater the change in depth, the more accurate the 

estimated application rate will be.) This is considered Depth 2. Record results in inches. 

Note the location of irrigation nozzle with a second stake at the same time of the second depth measure. 

Measure the distance between the two stakes (in feet). 

Calculate the application rate by multiplying the area by the difference between Depth 1 and Depth 2 (i.e., 

Depth 1 - Depth 2). Multiply this result by 27,200 (conversion factor). Divide this number by the distance 

between the two stakes, and divide this result by the diameter of the wetted circle. Your application rate 

will be given in gallons per acre. Note that this test assumes that your irrigation sprinklers do not overlap 

when applying. If your sprinklers do overlap, you need to ensure that you account for the overlap when 

calculating your rate. You can use the spacing between sprinkler pulls or run when calculating your rate. 

If using a center pivot irrigation system: 

Note the location of the pivot irrigation system and at the same time the liquid level in the storage tank on 

the yardstick. If possible, measure depth to the nearest quarter inch. Mark the irrigation nozzle location 

with a stake; this is considered Depth 1. Record results in inches. 

When the pivot has completed an entire circle, note the wastewater depth again. This is considered Depth 

2. Record results in inches. 

Calculate the application rate by multiplying the area by the difference between Depth 1 and Depth 2 (i.e., 

Depth 1 - Depth 2). Multiply this result by 0.62 (conversion factor). Divide this number by the acres under 

the pivot, and divide this result by the fraction of the circle your pivot was able to complete. For example, 

if your pivot completes an entire circle, the fraction is 1. If it only completes 2/3 of the circle, the fraction is 

0.667. Your application rate will be given in gallons per acre. 

A center pivot is designed for a uniform pumping rate (GPM) and pressure. If this rate and pressure are 

used for animal waste, you already know how many gallons are applied per time unit and you know how 

long it take the unit to complete a circle (the ground drive is usually electric). Therefore, you can calculate 

J-5
total gallons without running the system. Then divide by the acres under the system and you have the rate 

per acre. It is useful to check this periodically, though your rate should not change unless the pump is 

damaged or worn. If you add fresh water to the mix, then the total gallons of animal waste is reduced by a 

like amount, but the fact remains that a sprinkler will only put out a set volume at a given pressure. 

References 

Northeast Regional Agricultural Engineering Service. Fertilizer and Manure Application Equipment, 

NRAES-57, April 1994. 

Maryland Institute for Agricultural and Natural Resources. Fact Sheet: Calibrating Manure Spreaders, 

Fact Sheet 419. 

Cooperative Extension, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln. 

Manure Applicator Calibration, G95-1267A. 

Who to Contact for More Information 

Your Local Cooperative Cooperative Extension Office 

Your Local Land Grant University 

National Water Management Center/Natural Resources Conservation Service (USDA) 

J-6
APPENDIX K - SOIL LOSS (EROSION) 

Calculating Soil Loss 

Erosion losses are frequently estimated by the Universal Soil Loss Equation and the Revised 

Universal Soil Loss Equation (RUSLE). The basic equation is 

A = R * K * LS * C * P 

where: 

A = estimated average soil loss in tons per acre per year 

R = rainfall-runoff erosivity factor 

K = soil erodibility factor 

L = slope length factor 

S = slope steepness factor 

C = cover-management factor 

P = support practice factor 

See the Agriculture Handbook (No. 703, USDA, 1997), which describes RUSLE in great detail. 

Another factor for soil loss is called the "T value" which stands for "Tolerable Soil Loss." 

It is not directly used in RUSLE equation, but is often used along with RUSLE for conservation 

planning. 

Soil Loss Tolerance (T) 

Soil loss tolerance (T) is the maximum amount of soil loss in tons per acre per year, that 

can be tolerated and still permit a high level of crop productivity to be sustained economically 

and indefinitely. EPA encourages alternative approaches that tie the pollutant reductions to “T”, 

the soil loss tolerance factor. “T” is defined as the maximum amount of erosion at which the 

quality of a soil as a medium for plant growth can be maintained. T factors commonly serve as 

objectives for conservation farm planning. These objectives assist in the identification of 

cropping sequences and management systems that will maximize production and sustain longterm productivity. T factors represent the goal for maximum annual soil loss, in the context of 

maintaining the long term sustainability goal. This includes maintaining (1) the surface soil as a 

seedbed for plants, (2) the interface between the air and the soil that allows the entry of air and 

water into the soil and still protect the underlying soil from wind and water erosion, and (3) the 

total soil volume as a reservoir for water and plant nutrients, which is preserved by minimizing 

soil loss. 

For more information see Natural Resources Conservation Service, National Soil Survey 

Handbook, title 430-VI (Washington, D.C., U.S. Government Printing Office, September 1999). 

K-1
APPENDIX L - WINTER SPREADING TECHNICAL GUIDANCE 

Interim Final 

Technical Guidance 

for the 

Application of CAFO Manure on Land in the Winter 

Water Division 

Region 5 

United States Environmental Protection Agency 

Introduction1 

Many owners or operators of concentrated animal feeding operations (CAFOs) utilize their 

manure, litter, and process wastewater (hereinafter “manure”) as a source of nutrients for the growth of 

crops or forage or to improve the tilth of soil. Others dispose of manure on land. The longer manure 

remains in the soil before plants take the nutrients up the more likely those nutrients will be lost through 

volitization, denitrification, leaching to subsurface drainage tile lines or ground water, and runoff to surface 

water. To utilize the greatest fraction of the nutrients in manure, late spring and early summer are the best 

times for land application. Some CAFO owners or operators apply manure on land in the late fall or winter 

because crops are not growing, labor is available and, when it is frozen, the soil is able to handle the 

weight of manure hauling equipment without excessive compaction. Application in the late fall or winter 

also enables the owner or operator to avoid the cost of the structures that would be needed to store 

manure through the winter months. From the dual perspectives of nutrient utilization and pollution 

prevention, however, winter is the least desirable time for land application. Appendix 1 contains an 

excerpt from the United States Environmental Protection Agency (EPA) (2002) summarizing the literature 

on the risk that land application in the winter poses to water quality. See page 19. 

Under regulations that EPA promulgated in 2003, agencies that are authorized to issue National 

Pollutant Discharge Elimination System permits (hereinafter “states”) need to have technical standards for 

nutrient management which address, among other factors, the times at which CAFOs may apply manure 

on land (see Title 40 of the Code of Federal Regulations, section 123.36). Technical standards are to 

achieve realistic crop or forage production goals while minimizing movement of nitrogen and phosphorus 

to waters of the United States. They will form the basis for the nutrient management plans that CAFO 

owners and operators will implement under 40 CFR sections 122.42 and 412.4. 

EPA recognizes certain times during which there may be an increased likelihood that runoff from 

CAFO land application areas may reach waters of the United States. The times include, among others, 

when the soil is frozen or covered with ice or snow. Frozen soil will occur in areas where snow or other 

ground cover is shallow and where prolonged periods of subfreezing air temperatures prevail (United 

States Army Corps of Engineers 1998). The January normal daily minimum air temperature in EPA 

Region 5 ranges from minus eight degrees Fahrenheit in the northwest to 22 degrees Fahrenheit in the 

south. Thus, all areas in the Region are subject to air temperatures that can cause soil to freeze. For the 

months of December through March, the mean precipitation in the Region ranges from three inches of 

water in the northwest to 14.6 inches of water in the south. The mean snowfall in these months ranges 

1 In accordance with the United States Environmental Protection Agency (2000), 

Region 5 asked three professional engineers to review a February 2004 draft of this document. The peer 

review record includes responses to the comments that these individuals provided pursuant to the request. 

L-1
from 13 inches in the south to 108 inches in the coastal north. The above normals notwithstanding, the 

only reliable way to predict temperature and precipitation prior to any winter is through statistical analysis 

of historical data for the location of interest. 

To assure effective implementation of the regulations, EPA (2003) has expressed its strong 

preference that states prohibit the discharge of manure from land application. That is unless the discharge 

is an agricultural storm water discharge (i.e., a precipitation-related discharge from land where manure 

was applied in accordance with a nutrient management plan). EPA has also expressed its strong 

preference for the way in which states should address the timing of land application in their technical 

standards. With regard to the winter months, EPA strongly prefers that technical standards either prohibit 

surface application on snow, ice, and frozen soil or include specific protocols that CAFO owners or 

operators, nutrient management planners, and inspectors will use to conclude whether or not application 

to a frozen or snow- or ice-covered field or a portion thereof poses a reasonable risk of runoff. Where 

there is a reasonable risk, EPA strongly prefers that technical standards prohibit application on the field or 

the pertinent portion thereof during times when the risk exists or may arise. 

Technical Guidance 

The purpose of this paper is to present technical guidance to which EPA Region 5 will refer as we 

work together with those states that plan to allow CAFO owners or operators to apply manure on land in 

the winter where a crop will not be grown in that season or nutrients need not be applied in the winter to 

grow the crop. For this purpose, Region 5 assumes that the risk of runoff will be minimized if a state 

requires injection or timely incorporation of manure in the winter, provided that the CAFO owner or 

operator adheres to the setback requirements in 40 CFR section 412.4(c)(5). Further, we assume that the 

risk of runoff will be minimized if waters of the United States, sinkholes, open tile line intake structures, 

and other conduits to waters of the United States are upslope from the land on which manure would be 

surface applied. Thus, the balance of this technical guidance is intended to provide a basis for the Region 

to evaluate the adequacy of preliminary technical standards that would allow surface application without 

timely incorporation where waters of the United States, sinkholes, open tile line intake structures, or other 

conduits to waters of the United States are downslope from the land on which the manure would be 

applied2 

. 

Potential Discharges that are not Precipitation-related 

When liquid manure is applied on frozen soil in the absence of snow cover, Region 5 has 

concluded that the manure will run off and potentially discharge if it is applied in excess of the pertinent 

rate specified in Table 1a or 1b below3 

. See Appendix 2 on page 21 for an example that shows how the 

Region came to this conclusion. In as much as the discharge of manure is not an agricultural storm water 

discharge when it is not related to precipitation, technical standards need to prohibit the application of 

liquid manure on frozen soil, in excess of the rates provided in the following tables, when the soil is not 

covered with snow. 

2 For the purpose of this technical guidance, “other conduits to waters of the United States” 

means any area wherein water is or may be conveyed to waters of the United States via channelized flow. 

3 Region 5 developed the tables for the corn and soybean crops commonly grown in the Region. 

On request, the Region can supply tables for other land uses and land cover and treatment practices. 

L-2
Liquid Manure Maximum Rates of Application onto Frozen Soil 

Table 1a

 Harvested Crops were Row Crops Planted in Straight Rows 

Land in Good Hydrologic Condition 

Hydrologic Soil Group4 Maximum Rate of Application 

(gallons per acre) 

A 3,000 

B 1,600 

C 1,100 

D 1,100 

Liquid Manure Maximum Rates of Application onto Frozen Soil 

Table 1b 

Harvested Crops were Close-seeded Legumes Planted in Straight Rows 

Land in Good Hydrologic Condition 

Hydrologic Soil Group Maximum Rate of Application 

(gallons per acre) 

A 4,100 

B 2,200 

C 1,100 

D 1,100 

Discharges that are Precipitation-related 

When manure is applied on land in the winter, Region 5 assumes that nutrients and manure 

pollutants will dissolve or become suspended in any precipitation which comes into contact with the 

manure. This assumption is consistent with the findings reported in Appendix 1 and Table 4. The 

technical guidance that follows is intended to provide a basis for the Region to evaluate the adequacy of 

preliminary technical standards as such standards affect the movement of nutrients and manure pollutants 

in precipitation runoff during the winter or early spring. Six substantive steps are presented below. The 

first three involve the formulation of state policy for nutrient management. As contemplated in Step 1, the 

policy should include a standard for the concentration or mass of biochemical oxygen demand in 

precipitation-related discharges. Nutrients, including ammonia and nitrite, contribute to this demand. The 

final three involve engineering analysis to determine whether the BOD standard will be met. 

4 See Appendix A in the United States Department of Agriculture, Soil Conservation Service, 

(1986) for information on the Hydrologic Soil Group within which a given soil is classified. The appendix 

may be viewed at http://www.wcc.nrcs.usda.gov/hydro/hydro-tools-models-tr55.html. 

L-3 
Step 1: In collaboration with the Region, the state establishes a standard for the concentration or mass of 

BOD that will be permitted in precipitation-related discharges from land on which manure has 

been surface applied in the winter. 

Step 2: A. The state establishes preliminary technical standards for the setback5

 and the type, form, and 

maximum quantity of manure that could be surface applied on land in the winter. Standards for 

the setback should be expressed in terms of distance and slope. The minimum distance is that 

required under 40 CFR section 412.4(c)(5). As required to use Equations 2 or 3, below, standards 

for the setback should also be expressed in terms of the land cover and treatment practice and 

the crop residue rate (in the case of Equation 2) or the Hydrologic Soil Group (in the case of 

Equation 3). See Tables 2 and 3 on pages 10 and 13 for information on various residue rates and 

land cover and treatment practices. 

B. If the standard established in Step 1 is expressed as a mass, the state establishes additional 

preliminary technical standards for the land cover and treatment practice and Hydrologic Soil 

Group applicable to land that is upslope from the setback. 

Step 3: So the Region can perform the engineering analysis, the state establishes appropriate design 

conditions for the land use, form of precipitation (rain or ripe snow), depth of precipitation, and the 

temperature and moisture content of soil. At a minimum, the design condition for the moisture 

content of soil should be antecedent moisture condition III (i.e., saturated soil) (Wright 2004, 

Linsley, et al., 1982). States should carefully review climate data to determine whether the design 

temperature of soil should be 0 °C or less. In no case should the design temperature of soil 

exceed 3 °C. 

Step 4: The Region calculates the percent removal of BOD that will occur in the setback given the design 

conditions and preliminary technical standards. Calculating the percent removal is a two-step 

process as shown in A. and B. below. 

A. Calculate the amount of time it takes water to travel or “concentrate” (Tc) across the setback 

distance. Two equations are provided below as options for calculating Tc. In general, use 

Equation 1 (USDA, Natural Resources Conservation Service, 2002a) when the design condition 

consists of rain on frozen soil or rain on ripe snow or when the preliminary technical standards 

specify a residue rate equal to or greater than 20 percent. Use Equation 3 (USDA, NRCS, 1993) 

when the design condition consists of ripe snow, the preliminary technical standards do not 

specify a residue rate, or the rate is less than 20 percent. 

Eq. 1 Tc (hr) = Tt (overland) + Tt (shallow concentrated) 

where 

Tt (overland) = 0.007 A (N A L)0.8 Eq. 2

 (P0.5) A (s0.4) 

5 The term “setback” is defined in 40 CFR section 412.4 to mean a specified distance from 

surface waters (i.e., waters of the United States) or potential conduits to surface waters where manure 

may not be land applied. 

L-4 
N = Manning’s roughness coefficient for overland flow. See 

Table 2 on page 10 to select a coefficient that is 

appropriate in light of the preliminary technical standards. 

L = overland flow portion of the setback distance (maximum 

of 100 feet) (ft). 

P = precipitation design depth (in). 

s = preliminary technical standard for the slope over the 

distance L (ft/ft). 

Tt (shallow concentrated) applies to the shallow concentrated flow portion of the setback 

distance. In other words, it applies to the portion that is between points (a) and 

(b) as described below. 

Point (a): 100 feet downslope from the furthest downslope point at which manure 

would be applied under the preliminary technical standards. 

Point (b): the nearest waters of the United States, sinkhole, open tile line intake 

structure, or other conduit to waters of the United States. 

Tt (shallow concentrated) is determined by multiplying the above distance times a velocity 

of runoff that is appropriate in light of the preliminary technical standards. See 

Figure 2 on page 12. 

Tc (hr) = 5 A (L0.8) A (S+1)0.7

3 1900 A (s0.5)

Eq. 3 

where 

L = preliminary technical standard for the setback distance (ft). 

S = potential maximum retention after runoff begins 

= 1000 - 10

 CN

CN = runoff curve number. See Table 3 on page 13 to select a number 

that is appropriate in light of the design condition for the land use 

and the preliminary technical standards. 

s = preliminary technical standard for the slope over the distance L 

(percent). 

B. Calculate the percent removal of BOD in the setback. The equation for percent 

removal is as follows (modified from Martel, et al., 1980): 

Eq. 4 ) A t E = (1 - A A e-(kT ) A 100 

where 

L-5 
E = percent removal of BOD. 

A = nonsettleable fraction of BOD in manure 

= 0.5 to 0.6 for animals other than mature dairy cows (Zhu 2003) 

= 0.9 for mature dairy cows (Wright 2004). 

kT = first-order reaction rate constant at the design temperature of soil 

(T) (°C)

T-20 = k A (2) . 

2 = 1.135 (Schroepfer, et al., 1964) 

k = 0.03/min6 

. 

t = detention time 

= Tc A 60. 

Step 5: The Region multiplies the percent removal calculated in Step 4. B. times the initial concentration 

of BOD in runoff from land where manure has been surface applied (i.e., the concentration prior to 

treatment of the runoff by land in the setback). If state-specific data are not available, use the 

values from Table 4 as the basis for assumptions about the initial concentration (see page 16). 

Subtract from the initial concentration the product of the percent removal times the initial 

concentration. If the standard established in Step 1 is expressed as a mass, proceed to Step 6. 

If it is expressed as a concentration, compare the final concentration to the standard. If the final 

concentration is less than or equal to the standard, then the Region will conclude that there is no 

reasonable risk of runoff. The Region will neither object to nor disapprove the state’s preliminary 

technical standards. However, for the analysis to hold, the technical standards need to require the 

CAFO owner or operator to verify that conditions in the setback at the beginning of any application 

are consistent with the values assigned to N or S. In other words, the standards need to prohibit 

surface application when ice reduces the surface roughness or occupies the surface storage in 

the setback. If the concentration is greater than the standard established in Step 1, then the 

Region will conclude that there is a reasonable risk of runoff. Therefore, the final technical 

standards need to prohibit surface application of manure in the winter (or on frozen or snowcovered soil) or the state needs to otherwise strengthen the preliminary technical standards so 

there is no reasonable risk of runoff. 

Step 6: If the standard is expressed as a mass, the Region calculates the mass of BOD that will run off 

the land given the design conditions for the land use, depth of precipitation, soil temperature, and 

soil moisture content as well as the preliminary technical standards for the Hydrologic Soil Group, 

land cover and treatment practice, and the type and maximum quantity of liquid manure. 

Calculating the mass is a three-step process as shown below. 

A. Use the following equation (USDA, NRCS, 1993) to calculate the inches of runoff. 

6 The k value of 0.03 per minute is as reported by Martel, et al., for treatment of municipal 

wastewater by the overland flow process. The Region assumes that Martel, et al., reported the constant 

at 20 °C consistent with standard engineering practice. 

L-6 
Eq. 5 Q = (P - 0.2 A S)2 

(P + 0.8 A S) 

where 

Q = runoff (in). 

P = precipitation design depth plus the depth of water that could be 

applied in the winter as liquid manure given the preliminary 

technical standards (in). 

S is as defined for Equation 3 except that, if the design temperature of soil is 0 °C 

or less, substitute Sf

 for S where Sf = (0.1 A S) (Mitchell, et al., (1997)). 

B. Use the following equation to convert the runoff from inches to a volume per acre. 

Eq. 6 Q (gal/ac) = Q(in) A ft/12 in A 43,560 ft2

/ac A 7.48 gal/ft3 

C. Calculate the mass of BOD in runoff by multiplying the volume of runoff times the final 

concentration of BOD calculated in Step 5. The equation is as follows: 

Eq. 7 BOD (lb/ac) = BOD (mg/L) A Q (gal/ac) A 3.7854 L/gal A g/1000mg A 0.0022 lb/g

Compare the mass with the standard established in Step 1. If the mass is less than or equal to 

the standard, then the Region will conclude that there is no reasonable risk of runoff. The Region 

will neither object to nor disapprove the preliminary technical standards. However, for the analysis 

to hold, the technical standards need to require the CAFO owner or operator to verify that 

conditions in the setback at the beginning of any application are consistent with the values 

assigned to N or S. In other words, the standards need to prohibit surface application when ice 

reduces the surface roughness or occupies the surface storage in the setback. If the mass is 

greater than the standard established in Step 1, then the Region will conclude that there is a 

reasonable risk of runoff. Therefore, the final technical standards need to prohibit surface 

application of manure in the winter (or on frozen or snow-covered soil) or the state needs to 

otherwise strengthen the preliminary technical standards so there is no reasonable risk of runoff. 

L-7
--

Table 2 

Recommended Manning’s Roughness Coefficients for Overland Flow 

Engman (1986) 

Cover or treatment Residue rate 

(ton/acre)7 

Recommended 

coefficient 

Range 

Bare clay-loam 

(eroded) 

0.02 0.012 to 0.033 

Fallow - no residue 0.05 0.006 to 0.16 

Chisel plow < 0.25 0.07 0.006 to 0.17 

0.25 to 1 0.18 0.07 to 0.34 

1 to 3 0.3 0.19 to 0.47 

> 3 0.4 0.34 to 0.46 

Disk/harrow < 0.25 0.08 0.008 to 0.41 

0.25 to 1 0.16 0.1 to 0.25 

1 to 3 0.25 0.14 to 0.53 

> 3 0.3 

No till < 0.25 0.04 0.03 to 0.07 

0.25 to 1 0.07 0.01 to 0.13 

1 to 3 0.3 0.16 to 0.47 

Moldboard plow (fall) 0.06 0.02 to 0.1 

Coulter 0.1 0.05 to 0.13 

Range (natural) 0.13 0.02 to 0.32 

Range (clipped) 0.1 0.02 to 0.24 

Short grass prairie 0.15 0.1 to 0.2 

Dense grass 0.24 0.17 to 0.3 

7 See Figure 1 to convert residue cover from a percent to a mass. 

L-8 
USDA, NRCS, (2002b). 

L-9
Figure 2 

Average Velocity of Shallow Concentrated Flow 

USDA, NRCS, (1993) 

L-10€
Table 3 

Runoff Curve Numbers for Hydrologic Soil-Cover Complexes8 

USDA, NRCS, (1993), USDA, SCS, (1986) 

Land use Treatment or practice Hydrologic condition9 Hydrologic Soil 

Group 

A B C D 

Fallow Bare soil 89 94 97 98 

Crop residue cover Poor 89 94 96 98 

“ Good 88 93 95 96 

Row crops Straight row Poor 86 92 95 97 

“ Good 83 90 94 96 

Straight row and crop 

residue cover 

Poor 86 91 95 96 

“ Good 81 88 92 94 

Contoured Poor 85 91 93 95 

“ Good 82 88 92 94 

Contoured and crop 

residue 

Poor 84 90 93 95 

“ Good 81 88 92 94 

Contoured and terraced Poor 82 88 91 92 

“ Good 79 86 90 92 

8 The runoff curve numbers in Table 3 apply to saturated soil conditions (i.e., antecedent moisture 

condition III). See Appendix 3 on page 22 for runoff curve numbers applicable to average soil moisture 

conditions. 

9 According to USDA, SCS, (1986), hydrologic condition is based on a combination of factors, 

including (a) density and canopy of vegetative areas, (b) amount of year-round cover, (c) amount of grass 

or close-seeded legumes in rotations, (d) percent of residue cover on the land surface (good $ 20 

percent), and (e) degree of surface roughness. 

L-11 
Land use Treatment or practice Hydrologic condition Hydrologic Soil 

Group 

A B C D 

Contoured, terraced, 

and crop residue 

Poor 82 87 91 92 

“ Good 78 85 89 91 

Small grain Straight row Poor 82 89 93 95 

Contoured Poor 80 88 92 94 

“ Good 78 87 92 93 

Contoured and crop 

residue 

Poor 79 87 92 93 

“ Good 78 86 91 93 

Contoured and terraced Poor 78 86 91 92 

“ Good 77 85 90 92 

Contoured, terraced, 

and crop residue 

Poor 78 86 90 92 

“ Good 76 84 89 91 

Close-seeded 

legumes10 or rotation 

meadow 

Straight row Poor 82 89 94 96 

“ Good 76 86 92 94 

Contoured Poor 81 88 93 94 

“ Good 74 84 90 93 

Close-seeded 

legumes11 or rotation 

meadow 

Contoured and terraced Poor 80 87 91 93 

10 Close-drilled or broadcast. 

11 Close-drilled or broadcast. 

L-12 
Land use Treatment or practice Hydrologic condition Hydrologic Soil 

Group 

A B C D 

“ Good 70 83 89 91 

Pasture or range Poor 84 91 94 96 

Fair 69 84 91 93 

Good 59 78 88 91 

Contoured Poor 67 83 92 95 

“ Fair 43 77 88 93 

“ Good 13 55 85 91 

Meadow Good 50 76 86 90 

Table 4 

Assumed Initial Concentration of BOD in Runoff 

from Land on which Manure or Process Wastewater has been Surface Applied 

Type of Material Initial Total BOD in Runoff (mg/L) 

Broiler manure12 708 

Cattle (other than mature dairy Reserved 

cow) manure 

Cattle open lot process Reserved 

wastewater 

Egg wash process wastewater Reserved 

Feed storage process wastewater Reserved 

Layer manure13 809 

Mature dairy cow manure14 924 

Swine manure15 204 

Turkey manure Reserved 

12 Daniel, et al., (1995). 

13 Ibid. 

14 Thompson, et al., (1979) 

15 Daniel, et al., (1995). 

L-13 
References 

Daniel, T., D. Edwards, and D. Nichols. 1995. “Edge-of-Field Losses of Surface-Applied Animal Manure.” 

In: Animal Waste and the Land-Water Interface, ed. K. Steele. CRC Press, Inc. Boca Raton, Florida. 

Engman, E. T. 1986. “Roughness Coefficients for Routing Surface Runoff.” Journal of Irrigation and 

Drainage Engineering, vol. 112, pp. 39 to 53. 

Linsley, R., M. Kohler, and J. Paulhus. 1982. Hydrology for Engineers. McGraw-Hill. New York, New 

York. 

Martel, C., D. Adrian, T. Jenkins, and R. Peters. 1980. “Rational Design of Overland Flow Systems.” In: 

Proceedings of the ASCE National Conference on Environmental Engineering. American Society of Civil 

Engineers. Reston, Virginia. 

Mitchell, G., R. Griggs, V. Benson, and J. Williams. 1997. Environmental Policy Integrated Climate 

(EPIC) User’s Manual. United States Department of Agriculture, Agricultural Research Service. Temple, 

Texas. 

Schroepfer, G. , M. Robins, and R. Susag. 1964. “The Research Program on the Mississippi River in the 

Vicinity of Minneapolis and St. Paul.” In: Advances in Water Pollution Research, vol. 1. Pergamon. 

London, England. 

Thompson, D., T. Loudon, and J. Gerrish. 1979. “Animal Manure Movement in Winter Runoff for Different 

Surface Conditions.” In: Best Management Practices for Agriculture and Silviculture, Proceedings of the 

1978 Cornell Agricultural Waste Management Conference, eds. R. Loehr, D. Haith, M. Walter, and C. 

Martin. Ann Arbor Science Publishers, Inc. Ann Arbor, Michigan. 

United States Army Corps of Engineers. 1998. Engineering and Design - Runoff from Snowmelt. EM 

1110-2-1406. Washington, D.C. 

United States Department of Agriculture, Natural Resources Conservation Service. 2002a. Urban 

Hydrology for Small Watersheds. Technical Release 55 (WinTR-55). Washington, D.C. 

United States Department of Agriculture, Natural Resources Conservation Service. 2002b. Residue 

Management Seasonal (Acre). Conservation Practice Standard 344. DesMoines, Iowa. 

United States Department of Agriculture, Natural Resources Conservation Service. 1993. National 

Engineering Handbook, Part 630, Hydrology. Washington, D.C. 

United States Department of Agriculture, Natural Resources Conservation Service. 1986. Urban 

Hydrology for Small Watersheds. Technical Release 55. Washington, D.C. 

United States Environmental Protection Agency. 2003. NPDES Permit Writers’ Guidance Manual and 

Example NPDES Permit for Concentrated Animal Feeding Operations. EPA-833-B-04-001. Washington, 

D.C. 

United States Environmental Protection Agency. 2002. Development Document for the Final Revisions to 

the National Pollutant Discharge Elimination System Regulation and Effluent Limitations Guidelines for 

Concentrated Animal Feeding Operations. EPA-821-R-03-001. Washington, D.C. 

United States Environmental Protection Agency. 2000. Peer Review Handbook, 2nd Edition. EPA 100-B00-001. Washington, D.C. 

L-14
Wright, P. 2004. Letter to Steve Jann, EPA, Region 5. Cornell Cooperative Extension. Ithaca, New 

York. 

Zhu, J. 2003. Personal communication with Steve Jann, EPA, Region 5. University of Minnesota 

Southern Research and Outreach Center. Waseca, Minnesota. 

L-15
Appendix L-1 

The following is an excerpt from EPA (2002): 

[C]onsiderable research has demonstrated that runoff from manure application on frozen or 

snow-covered ground has a high risk of water quality impact. Extremely high concentrations of 

nitrogen and phosphorus in runoff have been reported from plot studies of winter-applied 

manure: 23.5 to 1,086 milligrams (mg) of total kjeldahl nitrogen (TKN) per liter (L) and 1.6 to 15.4 

mg/L of phosphorus (P) (Thompson, et al. 1979; Melvin and Lorimor 1996). In two Vermont field 

studies, Clausen (1990, 1991) reported 165 to 224 percent increases in total P concentrations, 

246 to 1,480 percent increases in soluble P concentrations, 114 percent increases in TKN 

concentrations, and up to 576 percent increases in ammonia-nitrogen (NH3-N) following winter 

application of dairy manure. Mass losses of up to 22 percent of applied nitrogen and up to 27 

percent of applied P from winter-applied manure have been reported (Midgeley and Dunklee 

1945; Hensler, et al., 1970; Phillips, et al., 1975; Converse, et al., 1976; Klausner, et al., 1976; 

Young and Mutchler 1976; Clausen 1990 and 1991; Melvin and Lorimor 1996). Much of this 

loss can occur in a single storm event (Klausner, et al., 1976). Such losses may represent a 

significant portion of annual crop needs. 

On a watershed basis, runoff from winter-applied manure can be an important source of annual 

nutrient loadings to water bodies. In a Wisconsin lake, 25 percent of annual P load from animal 

waste sources was estimated to arise from winter spreading (Moore and Madison 1985). In New 

York, snowmelt runoff from winter-manured cropland contributed more P to Cannonsville 

Reservoir than did runoff from poorly managed barnyards (Brown, et al., 1989). Clausen and 

Meals (1989) estimated that 40 percent of Vermont streams and lakes would experience 

significant water quality impairments from the addition of just two winter-spread fields in their 

watersheds. 

Winter application of manure can increase microorganism losses in runoff from agricultural land 

compared to applications in other seasons (Reddy, et al., 1981). Cool temperatures enhance 

survival of fecal bacteria (Reddy et al., 1981; Kibby, et al., 1978). Although some researchers 

have reported that freezing conditions are lethal to fecal bacteria (Kibby, et al., 1978; Stoddard, 

et al., 1998), research results are conflicting. Kudva, et al., (1998) found that Escherichia coli 

can survive more than 100 days in manure frozen at minus 20 degrees Celsius. Vansteelant 

(2000) observed that freeze/thaw of soil/slurry mix only reduced E. coli levels by about 90 

percent. Studies have found that winter spreading of manure does not guarantee die-off of 

Cryptosporidium oocysts (Carrington and Ransome 1994; Fayer and Nerad 1996). Although 

several studies have reported little water quality impact from winter-spread manure (Klausner 

1976; Young and Mutchler 1976; Young and Holt 1977), such findings typically result from 

fortuitous circumstances of weather, soil properties, and timing/position of manure in the 

snowpack. The spatial and temporal variability and unpredictability of such factors makes the 

possibility of ideal conditions both unlikely and impossible to predict. 

L-16
Appendix L-2 

Example Derivation of the Maximum Rates 

for Liquid Manure Application on Frozen Soil 

Givens 

According to USDA, NRCS, (1993), the following are givens: 

Potential maximum retention after runoff begins (S) = 1000 - 10 

CN 

Runoff curve number (CN) = 1000 

S + 10

According to Mitchell, et al., (1997), the following is a given for frozen soil: 

Sf = 0.1 A S 

For CN in the range from zero to 100, Table 10.1 in USDA, NRCS, (1993), identifies the minimum depth of 

precipitation (P) at which the runoff curve begins under dry, average, and saturated antecedent soil 

moisture conditions. For example, for a CN of 91 and average antecedent soil moisture, the runoff curve 

begins when P equals 0.2 inches. 

Example 

Hydrologic Soil Group A.

Harvested crop was corn planted in straight rows.

The land is in good hydrologic condition.

The antecedent soil moisture is average.

Sf = (1000/64 - 10) A 0.1 = 0.56 

CNf = 1000/(0.56 + 10) = 94.7 • 95 

According to Table 10.1 in USDA, NRCS (1993), for a CN of 95, 0.11 inches is the minimum 

depth of precipitation (or other liquid) at which the runoff curve begins. Converting this depth to a 

volume per acre, 

Q (gal/ac) = 0.11 in A ft/12 in A 43,560 ft2

/ac A 7.48 gal/ft3 

results in 2,987 gallons per acre as the maximum quantity of liquid that can be applied on frozen 

soils in Hydrologic Soil Group A while precluding runoff. 

L-17
Appendix L-3 

Runoff Curve Numbers for Antecedent Moisture Condition II 

If the Curve Number for then the Curve Number 

AMC III is ... for AMC II is ... 

100 99 

99 96 

98 93 

97 91 

96 89 

95 87 

94 85 

93 83 

92 81 

91 79 

90 78 

89 76 

88 74 

87 73 

86 71 

85 70 

84 68 

83 67 

82 65 

81 64 

80 63 

79 62 

L-18
If the Curve Number for then the Curve Number for 

AMC III is ... AMC II is ... 

78 60 

77 59 

76 58 

75 57 

74 55 

73 54 

72 53 

71 52 

70 50 

69 49 

68 48 

67 47 

66 46 

65 45 

64 44 

63 43 

62 42 

61 41 

L-19
APPENDIX M - MINIMUM DEPTH OF RAIN AT WHICH RUNOFF BEGINS 

This appendix provides a methodology for estimating the minimum depth of precipitation required to 

produce runoff for a given field with a given runoff curve number. 

Step 1: Estimate the runoff curve for the field or land area of concern. Table 3 in Appendix L 

provides curve numbers for various combinations of land uses (e.g., row crops), cover treatment or 

practices (e.g., contoured), and hydrologic conditions (e.g., poor). The runoff curve numbers in this table 

represent Antecedent Moisture Condition III (e.g., saturated soils). To identify corresponding runoff curve 

numbers for Antecedent Moisture Condition II (i.e., average conditions) use either Appendix L-3 above or 

Tables 2-2b and 2-2c in Urban Hydrology for Small Watersheds, USDA-NRCS, 1986 (see Appendix M-2). 

To predict the possibility of runoff where rainfall is forecast in a season other than winter, it may be 

reasonable to use runoff curves for Antecedent Moisture Condition II. 

Step 2: Using Table 10.1 on page 10.7 of the USDA-NRCS National Engineering Handbook Part 

630, Hydrology (see Appendix M-1); select the curve number (CN) for the field being investigated. 

Step 3: For the selected curve number in Table 10.1, identify the minimum depth of precipitation 

in inches required to produce runoff for a given runoff curve number (Column 5, designated with the 

column header of Curve* starts where P =). 

M-1
Appendix M-1 

National Engineering Handbook Table 10.1 

Curve numbers (CN) and Constants for the Case Ia = 0.2 S 

M-2
------------------------------

Appendix M-2 

USDA Urban Hydrology for Small Watersheds (TR-55) 

Table 2-2a Runoff curve numbers for urban areas 1/ 

Curve numbers for 

-------------------------------------------Cover description --------

Average percent 

-----------hydrologic soil group -------------

Cover type and hydrologic condition impervious area 2/ A B C D 

Fully developed urban areas (vegetation established) 

Open space (lawns, parks, golf courses, cemeteries, etc.) 3/: 

Poor condition (grass cover < 50%) .......................................... 68 79 86 89 

Fair condition (grass cover 50% to 75%) .................................. 49 69 79 84 

Good condition (grass cover > 75%) ......................................... 39 61 74 80 

Impervious areas: 

Paved parking lots, roofs, driveways, etc. 

(excluding right-of-way) ............................................................. 98 98 98 98 

Streets and roads: 

Paved; curbs and storm sewers (excluding 

right-of-way) ................................................................................ 98 98 98 98 

Paved; open ditches (including right-of-way) .......................... 83 89 92 93 

Gravel (including right-of-way) ................................................. 76 85 89 91 

Dirt (including right-of-way) ...................................................... 72 82 87 89 

Western desert urban areas:

Natural desert landscaping (pervious areas only) 4/ ..................... 63 77 85 88 

Artificial desert landscaping (impervious weed barrier, 

desert shrub with 1- to 2-inch sand or gravel mulch 

and basin borders) ...................................................................... 96 96 96 96 

Urban districts:

Commercial and business ................................................................. 85 89 92 94 95 

Industrial ............................................................................................. 72 81 88 91 93 

Residential districts by average lot size:

1/8 acre or less (town houses) .......................................................... 65 77 85 90 92 

1/4 acre ................................................................................................ 38 61 75 83 87 

1/3 acre ................................................................................................ 30 57 72 81 86 

1/2 acre ................................................................................................ 25 54 70 80 85 

1 acre ................................................................................................... 20 51 68 79 84 

2 acres .................................................................................................. 12 46 65 77 82 

Dev lopin r eas e g u ban ar

Newly graded areas 

(pervious areas only, no vegetation) 5/ ................................................................ 77 86 91 94 

Idle lands (CN’s are determined using cover types 

similar to those in table 2-2c). 

1 Average runoff condition, and Ia= 0.2S. 2 The average percent impervious area shown was used to develop the composite CN’s. Other assumptions are as follows: impervious 

areas are directly connected to the drainage system, impervious areas have a CN of 98, and pervious areas are considered equivalent 

to open space in good hydrologic condition. CN’s for other combinations of conditions may be computed using figure 2-3 or 2-4. 3 CN’s shown are equivalent to those of pasture. Composite CN’s may be computed for other combinations of open space 

cover type. 4 Composite CN’s for natural desert landscaping should be computed using figures 2-3 or 2-4 based on the impervious area percentage 

(CN = 98) and the pervious area CN. The pervious area CN’s are assumed equivalent to desert shrub in poor hydrologic condition. 5 Composite CN’s to use for the design of temporary measures during grading and construction should be computed using figure 2-3 or 

2-4 based on the degree of development (impervious area percentage) and the CN’s for the newly graded pervious areas. 

Table 2-2b Runoff curve numbers for cultivated agricultural lands 1/ 

M-3 
------------------------ -------------------------- ------------- -------

Curve numbers for 

------------------Cover description -------

Hydrologic 

hydrologic soil group 

Cover type Treatment 2/ condition 3/ A B C D 

Fallow Bare soil — 77 86 91 94 

Crop residue cover (CR) Poor 

Good 

76 

74 

85 

83 

90 

88 

93 

90 

Row crops Straight row (SR) Poor 

Good 

72 

67 

81 

78 

88 

85 

91 

89 

SR + CR Poor 71 80 87 90 

Good 64 75 82 85 

Contoured (C) Poor 

Good 

70 

65 

79 

75 

84 

82 

88 

86 

C + CR Poor 69 78 83 87 

Good 64 74 81 85 

Contoured & terraced (C&T) Poor 

Good 

66 

62 

74 

71 

80 

78 

82 

81 

C&T+ CR Poor 65 73 79 81 

Good 61 70 77 80 

Small grain SR Poor 

Good 

65 

63 

76 

75 

84 

83 

88 

87 

SR + CR Poor 64 75 83 86 

Good 60 72 80 84 

C Poor 63 74 82 85 

Good 61 73 81 84 

C + CR Poor 62 73 81 84 

Good 60 72 80 83 

C&T Poor 61 72 79 82 

Good 59 70 78 81 

C&T+ CR Poor 60 71 78 81 

Good 58 69 77 80 

Close-seeded SR Poor 66 77 85 89 

 or broadcast Good 58 72 81 85 

 legumes or 

 rotation 

C Poor 

Good 

64 

55 

75 

69 

83 

78 

85 

83 

meadow C&T Poor 63 73 80 83 

Good 51 67 76 80 

1 Average runoff condition, and Ia=0.2S 

2 Crop residue cover applies only if residue is on at least 5% of the surface throughout the year. 

3 Hydraulic condition is based on combination factors that affect infiltration and runoff, including (a) density and canopy of vegetative areas, (b)

amount of year-round cover, (c) amount of grass or close-seeded legumes, (d) percent of residue cover on the land surface (good $20%), and (e)

degree of surface roughness.

Poor: Factors impair infiltration and tend to increase runoff. 

Good: Factors encourage average and better than average infiltration and tend to decrease runoff. 

M-4 
Appendix M-3 

M-5
M-6
APPENDIX N - RECOMMENDED BEST MANAGEMENT PRACTICES (BMPS) AND 

CONSERVATION PRACTICE STANDARDS 

There are several Best Management Practices (BMPs) and conservation practices to consider when 

planning and implementing a Nutrient Management Plan (NMP). This appendix contains some of USDA’s 

published practices, though many other practices exist. The practices you see here represent those that 

EPA believes may be the most helpful when planning your NMP. Consult your state or local Cooperative 

Extension Office for more information and other standards and practices. 

Description 

The Natural Resources Conservation Service (NRCS) is a division of USDA that provides leadership in a 

partnership effort to help people conserve, improve, and sustain our natural resources and the 

environment. NRCS relies on many partners to help set conservation goals, work with people on the land, 

and provide assistance. Its partners include conservation districts, state and federal agencies, NRCS 

Earth Team volunteers, agricultural and environmental groups, and professional societies. 

NRCS has published the National Handbook of Conservation Practices (NHCP), which includes 

conservation practice standards guidance for applying technology on the land, and sets the minimum level 

for acceptable application of the technology. The most commonly considered conservation practice 

standards that may be used are shown in the table below: 

Practice Practice 

Composting Facility (a) Pond Sealing or Lining - Flexible Membranes (a) 

Conservation Crop Rotation (a) Pond Sealing or Lining - Bentonite Sealant (a) 

Contour Buffer Strips (a) Residue Management, no-till and Strip Till 

Cover and Green Manure Crop Residue Management, Mulch Till 

Cross Wind Trap Strips Roof Runoff Management 

Diversions Spring Development 

Fences Strip cropping, Contour 

Filter Strips (a) Terraces 

Grade Stabilization Structure Trough or Tank 

Grassed Waterways Use Exclusion 

Irrigation Water Management Waste Management Systems (a) 

Nutrient Management (a) Waste Storage Facility (a) 

Pest Management Waste Treatment Lagoon (a) 

Pipelines Waste Utilization (a) 

N-1
National standards for each practice are available at the NRCS web site at 

http://www.ncg.nrcs.usda.gov/nhcp_2.html. State conservationists determine the national standards to 

apply on a state-wide level, and add detail to effectively implement the standards on a local level, including 

more restrictive levels, if warranted. Local standards cannot be less restrictive than the national 

standards. 

References 

Natural Resources Conservation Service, Department of Agriculture. Notice of Technical Guidance for 

Developing Comprehensive Nutrient Management Plans (CNMPs). 

Who to Contact for More Information 

Your Local Cooperative Cooperative Extension Office 

Your Local Land Grant University 

National Water Management Center/Natural Resources Conservation Service (USDA) 

N-2
APPENDIX O - EXAMPLE TECHNICAL STANDARD 

EXAMPLE EPA NUTRIENT MANAGEMENT TECHNICAL STANDARD 

I. Authority 

• 40 CFR 122.42 

• 40 CFR 123.36 

• 40 CFR 412.4 

• 40 CFR 412.37 

II. Applicability 

This technical standard applies to all land under the control of a CAFO owner or operator, whether 

it is owned, rented, leased, or under an access agreement, to which manure, litter, process 

wastewater or sludge from the production area is or may be applied, in States, Indian Country, 

and other Territories and Jurisdictions where US EPA has NPDES permit authority. 

III. Definition 

Nutrient management is a planned process to protect water quality by managing the amount, 

source, placement, form, timing and method of application of agricultural nutrients and soil 

amendments utilized for the production of crop, forage, fiber, and forest products. It is supplying 

essential nutrients in adequate amounts to balance and maintain the soil for healthy biology and 

quality plants while avoiding conditions inimical to the ecosystem. 

IV. Purposes 

A. Minimize pollution of waters of the United States from agricultural nutrient sources. 

B. Budget and supply nutrients for plant production 

C. Properly use manure, litter, process wastewater, and/or other organic by-products as a 

plant nutrient source. 

D. Maintain or improve the physical, chemical, and biological condition of the soil. 

V. Criteria 

A. Nutrient Management Plans Shall Meet the Following General Criteria 

A nutrient management plan (NMP) is a site specific, documented, management tool, prepared for 

reference and used by the producer or landowner, recording how nutrients are and will be used to 

achieve plant production and water quality protection. 

1. NMPs shall comply with all applicable federal, State, and local laws and 

regulations. The CAFO must reviewed the NMP annually. 

2. Plans for nutrient management shall be in accordance with the requirements of 

40 CFR 122.42, 412.4 and 412.37. Sources of information, among other things, 

to assist in the development of the plan can be found in the policy requirements of 

the NRCS General Manual Title 450, Part 401.03 (Technical Guides, Policy and 

O-1
Responsibilities) and Title 190, Part 402 (Ecological Sciences, Nutrient 

Management, Policy); technical requirements of the NRCS Field Office Technical 

Guide (FOTG); procedures contained in the National Planning Procedures 

Handbook (NPPH), the NRCS National Agronomy Manual (NAM) Section 503 

and NRCS Conservation Practice Standard Nutrient Management (590). 

3. Plans for nutrient management that are elements of a more comprehensive 

conservation plan shall recognize other requirements of the conservation plan 

and be compatible with its other requirements. 

4. The use of certified specialists in developing nutrient management plans is not 

required, but EPA does encourage CAFOs to make use of certified planners with 

the expertise to develop, or review and modify nutrient management plans. A 

certified planner is defined as someone who has been certified to prepare 

CNMPs by USDA or a USDA sanctioned organization. 

5. Plans developed for nutrient management that include the use of manure or other 

organic by-products will identify the size of the land base needed to enable plan 

implementation based on phosphorus, even when initial implementation will be 

based on nitrogen, unless other provisions that do not involve land application are 

made for utilizing the manure. 

6. A nutrient budget for nitrogen, phosphorus, and potassium must be developed 

that considers all potential sources of nutrients including, but not limited to animal 

manure and organic by-products, wastewater, biosolids, commercial fertilizer, 

crop residues, legumes credits, and irrigation water. 

THE FOLLOWING ARE KEY ELEMENTS IN THE DEVELOPMENT OF AN NMP 

B. Soil Sampling and Laboratory Analysis (Testing) 

1. CAFOs in nutrient non-impaired watersheds shall soil sample every 5 years at a 

minimum. CAFOs in watersheds listed on the CWA Section 303(d) list as nutrient 

impaired and CAFOs having a field(s) with Phosphorus Index Site Vulnerability 

Rating(s) of high or very high shall sample annually. 

2. Soil samples shall be collected and prepared according to the Land Grant 

University guidance or standard industry practice. 

3. Soil samples shall be analyzed according to accepted industry practice or Land 

Grant University guidance. Soil test analyses shall be performed by laboratories 

that are accepted in one or more of the following programs. 

a. State Certified Programs 

b. The North American Proficiency Testing Program (Soil Science Society of 

America), or 

c. Laboratories whose tests are accepted by Land Grant University in the 

State in which the tests will be used. 

4. Soil testing shall include analysis for any nutrients and soil components for which 

specific information is needed to develop the nutrient plan and monitor or amend 

O-2
the annual nutrient budget. Analyses are recommended for pH, electrical 

conductivity (EC), soil organic matter, nitrogen, phosphorus and potassium. 

5. The laboratory analysis for phosphorus shall be performed using the method 

recommended by the Land Grant University or by the following method: where 

the soil pH (using water pH test) is 7.5 or greater, an Olsen P-test will be done; 

where the soil pH is less than 7.5, the Mehlich 3 or Bray P-test will be done. 

C. Plant Tissue Sampling 

1. Tissue sampling and testing, where used, shall be collected, prepared, and 

analyzed according to accepted industry practice or Land Grant University 

guidance where it should be used. 

D. Manure and Wastewater Sampling (See Appendix C for waste sampling procedures) 

1. Manure and wastewater shall be analyzed a minimum of once annually for 

nitrogen and phosphorus content. The results of this analysis is to be used in 

determining application rates of manure, litter and wastewater. 

2. Manure and wastewater samples shall be collected, prepared, and analyzed 

according to accepted industry practice or Land Grant University guidance. 

E. Field Risk Assessment 

1. When animal manures or other organic by-products are land applied, a fieldspecific assessment of the potential for phosphorus transport from the field shall 

be completed. This assessment may be done using the Phosphorus Index or 

other recognized assessment tool adopted by the permitting authority. In such 

cases, plans shall include: 

a. A record of the assessment rating for each field or sub-field, and 

b. Information about conservation practices and management activities that 

can reduce the potential for phosphorus movement from the site. 

2. Erosion, runoff, and water management controls shall be installed, as needed, on 

fields that receive nutrients. Practices to control erosion should be less than or 

equal to “T”, as identified by the Revised Universal Soil Loss Equation (RUSLE). 

F. Nutrient Application Rates 

1. Nitrogen Application - The application rate for nitrogen shall be based on the 

utilization of crops at the recommended agronomic rates. When the plan is being 

implemented on a phosphorus standard, manure or other organic by-products 

shall be applied at rates, consistent with the phosphorus standard. In such 

situations, an additional nitrogen application, from non-organic sources, may be 

required to supply the recommended amounts of nitrogen. In no case shall 

manure or other organic by-products be applied above the nitrogen rate. 

Manure or other organic by-products may be applied on legumes at rates equal to 

the estimated removal of nitrogen in harvested plant biomass. 

O-3
2. Phosphorus Application - When manure or other organic by-products are used, 

the planned rates of phosphorus application shall be consistent with one of the 

following options: 

a. Phosphorus Index (PI) Rating 

Nitrogen or multi-year phosphorus based manure application on Low or 

Medium Risk sites, one-year phosphorus based manure application on 

High Risk sites and no manure application on Very High Risk Sites. 

b. Soil Phosphorus Threshold Values 

Nitrogen or multi-year phosphorus based manure application on sites on 

which soil test levels are below 0.75 times the threshold level, one-year 

phosphorus based manure application on sites on which soil test levels 

are more than 0.75 but less than 1.5 times the threshold level, and no 

manure application on sites on which soil test levels are more than 1.5 

times the threshold level.* 

c. Soil Test 

Nitrogen or multi-year phosphorus based manure application on sites 

where there is a soil test recommendation to supply phosphorus. Oneyear phosphorus based manure application on sites where the soil test 

level is greater than 75 but less than 150 ppm Bray P1. No manure 

application on sites where the soil test level is equal to or greater than 

150 ppm Bray P1. 

*Acceptable phosphorus based manure application rates shall be 

determined as a function of soil test recommendations or estimated 

phosphorus removal in harvested plant biomass. Guidance for 

developing these acceptable rates is found in the NRCS General Manual, 

Title 190, Part 402 (Ecological Sciences, Nutrient Management, Policy), 

and the National Agronomy Manual, Section 503. 

3. Planned rates of nutrient application, as documented in the nutrient budget, shall 

be determined based on soil test results, nutrient credits, waste analysis, crop 

need and sequence, seasonal and climatic conditions, and use and timing of 

irrigation water. 

4. Realistic yield goals shall be established based on soil productivity information, 

historical yield data, climatic conditions, level of management and/or local 

research on similar soil, cropping systems, and soil and manure/organic byproducts tests. For new crop or varieties, industry yield recommendations may be 

used until documented yield information is available. 

5. Plans for nutrient management shall specify the form, source, amount, timing, and 

method of application of nutrients on each field to achieve realistic production 

goals, while minimizing nitrogen and/or phosphorus movement to surface and/or 

ground waters. 

6. When actual crop yields exceed or fail to attain expected goals, the nutrient 

application rates for the succeeding crop must be adjusted to reflect that 

difference. 

7. Nutrient values of manure, litter, process wastewater, sludge, and organic byproducts shall be determined prior to land application based on laboratory 

O-4
analysis. “Book values” shall not be used except for planning of first year 

application(s) during initial start-up of the facility. Acceptable book values are 

those values recognized by ASAE, the NRCS, and/or the Land Grant University 

that accurately estimate the nutrient content of the material. 

8. Nutrient application rates shall not attempt to approach a site’s maximum ability to 

contain one or more nutrients as determined by the risk assessment methods in 

V.F.1.and 2. Excess applications or applications that cause soil imbalances 

should be avoided. Excess manure nutrients generated by the CAFO must be 

handled by export to a good steward of the manure, or the development of 

alternative uses. 

9. Nutrients shall be applied in such a manner as not to degrade the soil’s structure, 

chemical properties, or biological condition. 

10. The planned rates of nutrient application, as documented in the nutrient budget, 

shall be determined based on the following guidance: 

a. Nitrogen Application - Planned nitrogen application rates shall match the 

recommended rates as closely as possible. When manure or other 

organic by-products are a source of nutrients, additional nitrogen 

application, from non-organic sources, may be required to supply the 

recommended amounts of nitrogen. Split applications of nitrogen should 

be practiced to provide nutrients at the time of maximum crop utilization. 

b. Phosphorus Application - Planned phosphorus application rates shall 

match the recommended rates as closely as possible. 

11. Consider the use of variable-rate technology for management of supplemental 

nitrogen application to account for within-field spatial and temporal variability. 

12. Multiple-year phosphorus applications (“phosphorus banking”) - A single, 

multiple-year application of phosphorus applied as manure, litter, process 

wastewater, sludge, or other organic by-product may be applied to a field that 

does not have a high potential for nutrient movement as determined by one of the 

risk assessment methods in V.F.1. and 2. above. In a nutrient non-impaired 

watershed, this application shall not exceed the one year nitrogen application rate 

and shall not exceed three (3) times the one year phosphorus application rate. 

Following a multiple-year application in a nutrient non-impaired watershed, no 

application may be made until the applied phosphorus has been removed from 

the field via harvest or crop removal. In a nutrient impaired watershed, this 

application shall not exceed the nitrogen application rate and shall not exceed two 

(2) times the one year phosphorus application rate. Following a multiple-year 

application in a nutrient impaired watershed, no application may be made until the 

applied phosphorus has been removed from the field via harvest or crop removal. 

The multiple-year rates may be applied only if erosion and runoff control practices 

and buffers are installed to minimize risk of nutrient movement. 

G. Nutrient Application Timing 

1. Manure, litter, or process wastewater shall not be surface applied when the 

National Weather Service predicts a 50 percent or more probability of rain in 

excess of the amount that is reasonably likely to generated runoff, as provided 

below, within 24 hours of the end of an intended application. 

O-5
Minimum Quantity of Rainfall Required to Produce Runoff 

Hydrologic Soil Group Quantity of Rainfall (inches) 

A 1.0 

B 0.5 

C 0.25 

D 0.25 

See Appendix A in Urban Hydrology for Small Watersheds (USDA-SCS 1986) for 

information on the Hydrologic Soil Group within which a given soil is classified. 

The appendix may be viewed at http://www.wcc.nrcs.usda.gov/hydro/hydro-toolsmodels-tr55.html. The National Weather Service forecast may be viewed at 

http://www.nws.noaa.gov/mdl/forecast/graphics/MAV/index.html. At that address, 

select the precipitation forecast product that is appropriate given the Hydrologic 

Soil Group that represents the predominant soil type in the field where manure, 

litter, or process wastewater would be applied. For Hydrologic Soil Group B soils, 

this would be the forecast product labeled, “24H Prob.>=0.5in.,” for example. If 

the map that appears after selecting this product does not allow one to determine 

whether there is a 50 percent or more probability of the specified quantity of rain 

near the place where the field is located, then select the following National 

Weather Service address: 

http://www.nws.noaa.gov/mdl/synop/products/bullform.mex.htm. At that address, 

first select the state in which the field is located and then select the weather 

station closest to the field. Then press “Submit Query” at the bottom of the page. 

A table will appear after submitting the query. Locate the “Q24" entry in the first 

column and then locate the first number to the right of “Q24”. This number will be 

in the range from 0 to 6. These values correspond to the following amounts of 

precipitation: 0 = no precipitation, 1 = 0.01 to 0.09", 2 = 0.1 to 0.24", 3 = 0.25 to 

0.49", 4 = 0.5 to 0.99", 5 = 1 to 1.99", and 6 $ 2". 

2. Graduated markers in waste retention structures allow CAFO operators to know 

exactly how much liquid manure and/or process wastewater is in the waste 

treatment lagoon or waste storage pond. Waste retention structures must be 

maintained below the level designated in 40 CFR 412 to contain runoff from 

precipitation of a 25 year, 24-hour, or 100 year, 24-hour rainfall event as 

applicable. An NRCS designed waste retention structure that is maintained at the 

catastrophic storm storage level is not being operated as designed, i.e., 

maintaining the capacity to contain runoff and precipitation from a 25 year, 24­

hour or 100 year, 24-hour rainfall event as applicable. 

a. Waste storage ponds should be dewatered to the sludge level during 

months with a crop water demand that could use the water for crop 

production. DO NOT EXCEED NUTRIENT APPLICATION RATES 

BASED ON THE SITE-SPECIFIC RISK ASSESSMENT METHOD OR 

THE HYDRAULIC LOADING RATES. 

b. Waste treatment lagoons should be maintained at or just above the 

minimum treatment volume during months with a crop water demand that 

could use the water for crop production. DO NOT EXCEED NUTRIENT 

O-6
APPLICATION RATES BASED ON THE SITE-SPECIFIC RISK 

ASSESSMENT METHOD OR THE HYDRAULIC LOADING RATES. 

3. The timing of nutrient application must correspond as closely as possible with 

plant nutrient uptake characteristics, while considering cropping system 

limitations, weather and climatic conditions, and field accessibility. 

4. Avoid winter nutrient application for spring seeded crops. 

H. Nutrient Application Methods 

1. Except under conditions of agricultural storm water discharge as provided in 33 

U.S.C. 1362(14), there must be no discharge of manure, litter, or process

wastewater as a result of nutrient application by the CAFO. For example the 

direct discharge of to waters of the United States by spray irrigation. 

2. Apply nutrient materials uniformly to application areas or as prescribed by 

precision agricultural techniques. 

3. Consider immediate incorporation of land-applied manure, litter, sludge, and 

organic by-products to minimize risk of nutrient movement to surface waters. 

4. Supplementary commercial fertilizer(s) and/or soil amendments may be added 

when the application of nutrients contained in manure and/or process wastewater 

alone is not sufficient to meet the soil and crop needs, or when a nutrient excess 

occurs such that other nutrients become unavailable to the plant or toxic 

conditions arise. 

5. Process Wastewater Irrigation - Process wastewater application is not the same 

as irrigation. Process wastewater application scheduling should be based on the 

nutrient needs of the crop, the daily water use of the crop, the water-holding 

capacity of the soil, and the lower limit of soil moisture for each crop and soil. 

Process wastewater application via irrigation must be at rates that minimize 

transport of sediment, nutrients, and chemicals to waters of the United States. 

The amount of water applied to the field should be measured and natural 

precipitation should be accounted for. 

I. Setbacks and Vegetated Buffers 

1. A setback distance from conduits to surface water must be maintained unless the 

CAFO uses either one of the compliance alternatives: vegetated buffer or 

alternative practices. 

2. Setback - means a specified distance from waters of the United States or 

potential conduits to such waters where manure, litter, and process wastewater 

may not be land applied, but where crops may continue to be grown. The 

minimum width of a setback is 100 feet. Examples of conduits to waters of the 

United States include, but are not limited to: open tile line intake structures, 

sinkholes, karsts, ditches, cisterns and agricultural wellheads. 

3. Vegetated Buffer - means a narrow, permanent strip of dense perennial 

vegetation, where no crops are grown, established parallel to the contours of and 

perpendicular to the dominant slope of the field for the purposes of slowing water 

runoff, enhancing water infiltration, trapping pollutants bound to sediment, and 

O-7
minimizing the risk of any potential nutrients or pollutants from leaving the field 

and reaching waters of the United States. The minimum width of vegetated 

buffer is 35 feet. On a per foot basis, it is more effective at reducing runoff than 

the setback. Vegetated buffers include NRCS Codes 332, 386, 391, 393, and 

601. To the extent possible, the use of native vegetation should always be 

considered. 

4. The minimum widths of setbacks and vegetated buffers must be doubled around 

a sole-source drinking water supply wellhead. 

5. As a compliance alternative, the CAFO may demonstrate that a setback or buffer 

is not necessary because the implementation of alternative conservation 

practices of field-specific conditions will provide pollutant reductions equivalent or 

better than the reductions that would be achieved by the 100-foot setback. 

6. Practices and management activities for vegetated buffers 

a. Removal of vegetation in vegetated buffers will be in accordance with site 

production limitations, rate of plant growth, and the physiological needs of 

the plants. 

b. Do not mow below the recommended height for the plant species. 

c. Maintain adequate ground cover and plant density to maintain or improve 

filtering capacity of the vegetation 

d. Maintain adequate ground cover, litter, and canopy to maintain or 

improve infiltration and soil condition. 

e. Periodic rest from mechanical harvesting may be needed to maintain or 

restore the desired plant community following episodic events such as 

drought. 

f. When weeds are a significant problem, implement pest management to 

protect the desired plant communities. 

g. Prevent channels from forming. 

J. Considerations 

[High-quality soils prevent water pollution by resisting erosion, absorbing and partitioning rainfall, and 

degrading or immobilizing agricultural chemicals, manure, litter, process wastewater or other potential 

pollutants.] 

1. Conditions of the soil 

a. Because most coarse-textured soils have a low cation exchange 

(nutrient-holding) capacity, consider applications of manure, litter, sludge, 

process wastewater, and other organic by-products be restricted to 

several small applications during the growing season to minimize the 

chance of soluble nutrients reaching the ground water. 

O-8
b. Nutrient application on soils with less than 20 inches in depth to parent 

material, according to the Cooperative Soil Survey, shall not exceed the 

one year phosphorus application rate. 

c. Do not apply manure, litter, sludge, process wastewater, or other organic 

by-products over bedrock outcrops. 

d. Do not apply manure, litter, sludge, process wastewater, or other organic 

by-products on soils where the rock fragments in the top five feet of the 

surface layer are 3 - 10 inches in diameter and exceed 50% by volume. 

e. Do not apply manure, litter, sludge, process wastewater, or other organic 

by-products on soils where the rock fragments in the top five feet of the 

surface layer are >10 inches in diameter and exceed 25% by volume. 

f. Do not apply manure, litter, sludge, or process wastewater, or other 

organic by-products on soils where the slope is >15% according to the 

Cooperative Soil Survey. 

2. Saline soil 

a. Balance soil fertility to allow plant roots to grow through saline layer. 

b. If available, irrigation water may be used to leach salts below the root 

zone. Schedule salt leaching events to coincide with low residual soil 

nutrients and pesticides. 

c. Use of nutrient sources with high salt content will be minimized unless 

provisions are used to leach salts below the crop root zone. 

d. Micronutrients have a low availability on saline soils. Work to balance 

nutrients in the soil. 

e. On sites where there is a high soil salinity is a concern, the potassium 

application rate should not exceed 100% of the requirement needed over 

the entire crop rotation, or three years for perennial crops. 

f. On sites with pH values exceeding 8.5, consider adding gypsum to 

increase the availability and utilization of nutrients by the crop. 

3. Alkaline soil 

a. Alkaline soils have a high pH (above 7.0). This high pH is usually the 

result of too much calcium, potassium, sodium, or magnesium. 

b. Micronutrients such as iron, manganese, boron, and zinc are sparingly 

available in alkaline soils, leading to deficiencies in plants. Work to 

balance nutrients in the soil. 

c. Phosphorus deficiency may appear in plant tissue analyses as a result of 

little or too much phosphorus in the soil. Do not over apply phosphorus 

as determined by one of the risk assessment methods identified in 

V.F.1.and 2. above. 

O-9 
d. On alkaline soils, potassium should be applied near the time needed by 

the crop to minimize leaching. 

e. Calcium carbonate accumulations that inhibit root growth for some plants 

are common in many low-rainfall alkaline soils. This calcareous layer 

helps maintain high pH levels and constrains the availability of 

micronutrients. Balance the soil to optimize plant growth and nutrient 

uptake. 

4. Flooded ground (Flood irrigation is not a part of this definition) 

a. Nutrient, solid or liquid, shall not be applied to flooded soils. 

b. Agricultural waste shall not be land-applied on soils that are frequently 

flooded, as defined by the National Cooperative Soil Survey, during the 

period when flooding is expected. 

c. Manure, litter, sludge, process wastewater, and/or other organic byproducts may be applied to occasionally flooded areas during seasons 

when flooding is not expected and actively growing vegetation is present 

on over 50% of the field. 

5. Saturated ground 

a. Liquid manure and process wastewater shall not be applied on saturated 

soil where the manure or process wastewater may discharge to waters of 

the United States. The rate of application for liquid manure or process 

wastewater application on unsaturated soils shall not exceed the 

infiltration rate and moisture holding capacity of the soil after taking the 

antecedent moisture and temperature of the soil into account. 

b. Avoid soil compaction on soils with high moisture content. 

6. Drainage management 

Subsurface drainage expedites the transport of nitrate-nitrogen from the soil zone 

with the result that a significant amount of unused nitrogen (nitrate N) from farm 

fields ends up in nearby streams and other surface waters. 

a. The use of cover crops to utilize residual nitrates is recommended. 

b. Fields that are subsurface (tile) drained require additional precautions. 

When liquid wastes are applied to fields with subsurface (tile) drains, the 

liquid can follow soil macropores directly to the tile drains, creating a 

surface water pollution hazard from direct tile discharge. 

i. Do not apply application rates (volume) that would exceed the 

lesser of the available water capacity (AWC) in the upper 8 

inches, or 13,000 gallons/acre per application. See Appendix E, 

Available Water Capacity (AWC) Practical Soil Moisture 

Interpretations for Various Soils, Textures, and Conditions 

to Determine Liquid Waste Volume Applications not to 

Exceed AWC, to Determine AWC and the amount (volume) that 

can be applied to reach the AWC. 

O-10
ii. Prior to manure application, use a tool that can disrupt/close 

(using horizontal fracturing) the preferential flow paths (worm 

holes, cracks, root channels) in the soil, or till the surface of the 

soil 3 -5 inches deep to a condition that will absorb the liquid 

wastes. The purpose is to have the surface soil act as a sponge 

to soak up the liquid manure and keep it out of preferential flow 

channels. This is especially important if shallow tiles are present 

(<2 feet deep). Any pre-application tillage should leave as much 

residue as possible on the soil surface. The absorption of liquid 

manure by the soil in the root zone will minimize nitrogen loss 

and the manure/nutrient runoff potential. For perennial crops 

(hay or pasture), or continuous no-till fields where tillage is not an 

option, all tile outlets from the application area are to be plugged 

prior to application. 

iii. If injection, is used, inject only deep enough to cover the manure 

with soil. Till the soil at least 3 inches below the depth of 

injection prior to application, or all tile outlets from the application 

area are to be plugged prior to application. 

iv. In addition to tillage prior to surface liquid waste application or 

injection, install in-line tile flow control structures or inflatable tile 

plugs that can mechanically stop or regulate tile flow either prior 

to application, or have on site if needed to stop tile flow. Use 

caution not to back tile water where it may impair the functioning 

of an offsite subsurface drainage system. 

v. Repair broken tile or blowholes prior to application. 

c. In fields with existing drainage tiles, consider retrofitting to alternative 

water table management practices such as controlled drainage, 

subirrigation, and wetland reservoir subirrigation systems. 

d. The incorporation of BMPs like riparian zones, denitrifying ponds, and 

wetlands to reduce the level of nitrates before discharge into ditches and 

streams is encouraged. 

e. Design new subsurface drainage systems to manage soil water and 

water table levels through controlled drainage or subirrigation, lowering 

concentrations on nitrate-N in shallow ground water. 

7. Drought 

a. Cropping systems should be managed to maximize nutrient uptake from 

the soil and protect the soil during periods when erosion and potential 

nutrient runoff occurs. 

b. Decrease nutrient application rates on non-irrigated areas when drought 

conditions occur. 

c. Decrease grazing pressure pastures to maintain desired plant community 

and vegetation height. 

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d. Maintain adequate pasture conditions. This will maximize nutrient uptake 

by pasture plants and reduce nutrient flow into waterways. Overstocking 

pasture is a sure way to damage water quality. Overstocking damages 

plants, which reduces nutrient uptake and increases risk of erosion. 

e. Reducing stocking rates and grazing pressure is key to managing native 

rangeland and tame pastures both during and after drought. High 

stocking rates during drought can prompt a change in the plant 

community, reduce plant litter and organic matter, increase bare ground, 

and remove vegetation needed to trap manure solids and nutrient bearing 

sediment, which can decrease water infiltration from precipitation and 

increases runoff. 

8. Frozen ground 

a. Frozen ground is any portion of the 0 - 6 inch soil layer (root depth) that is 

frozen. 

b. Irrigation of wastewater to snow covered or frozen ground is prohibited 

c. Adequate manure storage volume shall be provided and maintained to 

prevent the necessity of land applying manure on frozen and/or snow 

covered ground. No later than October of each year, the CAFO shall 

evaluate the storage capacity in their manure storage or treatment 

facilities and determine what steps are needed to avoid the need to land 

apply manure on frozen or snow covered fields for the upcoming winter. 

The operating record for the facility shall include documentation of the 

storage level as well as what was considered in this evaluation, and what 

actions were taken to avoid the need for land application of manure on 

frozen or snow covered ground. 

d. Winter application of manure, litter, and other solid waste products is not 

desirable because nutrients cannot soak into frozen ground and manure 

accumulated on the surface of frozen soil or snow can easily be carried 

off the field during snow melt or other runoff events. In nutrient nonimpaired watersheds, if winter applications must be made, applications 

may only be made under the following conditions: The application does 

not exceed the one year phosphorus rate, the field has a slope not 

greater than 6%, cool-season crops are present and actively growing in 

the field, nutrients are needed to be supplied to the crop, and erosion and 

runoff control practices are installed to minimize risk of nutrient 

movement. When choosing a location for winter application; fields that 

are furthest from streams and waterbodies must be used first. In nutrient 

impaired watersheds, application of manure, litter, or other solid waste 

products to snow covered or frozen ground is prohibited. 

9. Heavy metals 

a. Plans developed for nutrient management that include the use of manure 

or other organic by-products will recognize that some manures contain 

heavy metals and should be accounted for in the plan for nutrient 

management. 

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b. When sewage sludge is applied, the accumulation of potential pollutants 

(including arsenic, cadmium, copper, lead mercury, selenium, and zinc) in 

soil shall be monitored in accordance with the US Code, Reference 40 

CFR, Parts 403 and 503, and/or any applicable State and local laws or 

regulations. 

K. Plans and Specifications 

1. Plans and specifications shall be in keeping with this standard and shall describe 

the requirements for applying the practice to achieve its intended purpose(s), 

using nutrients to achieve production goals and to prevent or minimize water 

quality impairment. 

L. Operation and Maintenance 

1. Periodically conduct leak inspections of equipment used for land application of 

manure, litter or process wastewater. 

2. Application equipment should be regularly (at least annually) calibrated to deliver 

the intended application rate and to achieve a uniform distribution pattern 

a. Equipment used to apply solid waste from dairy and beef should be 

calibrated to deliver within + 2 1⁄2 tons of the intended application rate. 

b. Equipment used to apply solid waste from swine should be calibrated to 

deliver within + 1 ton of the intended application rate. 

c. Equipment used to apply solid waste and litter from poultry and foul 

should be calibrated to deliver within + 1 ton of the intended application 

rate. 

d. Equipment used to apply organic by-products and solid waste from other 

animals should be calibrated to deliver within + 1 ton of the intended 

application rate. 

e. Equipment used to apply liquid or slurry waste should be calibrated to 

deliver 10 percent of the intended application rate. 

f. Process wastewater irrigation rate is characteristic of sprinkler hardware 

and operating parameters (i.e., nozzle type, size, trajectory, and 

pressure). Hence, irrigators should be selected to be compatible with soil 

infiltration rate or permeability. If irrigator application rate is higher than 

soil infiltration rate, the possibility for runoff is increased. Since runoff 

must be prevented when irrigating process wastewater, it is 

recommended that irrigators be selected for the lowest application rate 

possible. 

3. Records specified in this technical standard and in permit terms corresponding to 

40 CFY 412.37(b) and (c) shall be maintained on-site for five years, or for a 

period longer than five years if required by other federal, state, or local 

ordinances, or program or contract requirements. These records must be 

available to the permitting authority and the Regional Administrator, or his or her 

designee, for review upon request. 

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4. When cleaning equipment after nutrient application, remove and save fertilizers or 

waste in an appropriate manner. The saved residue material may be utilized on 

another crop as part of the fertilization program outlined in the NMP. If the 

equipment is flushed, keep wastewater away from high runoff areas, ponds, lakes 

streams, wells, and other water bodies. 

5. Dispose of fertilizer containers according to any applicable label directions and 

federal, state, and local laws. 

V. Additional Considerations 

A. Consider induced deficiencies of nutrients due to excessive levels of other nutrients. 

B. Consider additional practices to improve soil nutrient and water storage, infiltration, 

aeration, tilth, diversity of soil organisms, and to protect and improve water quality. 

1. Conservation Cover (327) 

2. Grassed Waterway (412) 

3. Contour Buffer Strips (332) 

4. Filter Strips (393) 

5. Irrigation Water Management (449) 

6. Riparian Forest Buffer (391A) 

7. Conservation Crop Rotation (328) 

8. Cover and Green Manure (340) 

9. Residue Management (329A, 329B, 329C, and 344) 

10. Waste Utilization (633) 

C. Consider cover crops whenever possible to utilize and recycling residual nitrogen. 

D. Consider application methods and timing that reduce the risk of nutrients being 

transported to ground and surface waters, or into the atmosphere. Suggestions include; 

1. Split applications of nitrogen to provide nutrients at the times of maximum crop 

utilization. 

2. Avoiding winter nutrient application for spring seeded crops. 

3. Band applications of phosphorus near the seed row. 

4. Applying nutrient materials uniformly to application areas or as prescribed by 

precision agricultural techniques, and/or 

5. Immediate incorporation of land applied manures or organic by-products. 

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6. Delaying field application of animal manures or other organic by-products if 

precipitation capable of producing runoff and erosion is forecast within 24 hours 

of the time of the planned application. 

E. Consider the immediate incorporation of manures into the soil after application to reduce 

nitrogen volatilization losses associated with the land application of animal manures. 

Volatilization losses can become significant, if manure is not incorporated immediately 

after application. 

F. Consider using soil test information no older than one year when developing new plans, 

particularly if animal manures are to be a nutrient source. 

G. Consider annual reviews to determine if changes in the nutrient budget are desirable (or 

needed) for the next planned crop. 

H. On sites on which there are special environmental concerns, consider other sampling 

techniques. (For example: Soil profile sampling for nitrogen, Pre-Sidedress Nitrogen Test 

(PSNT), Pre-Plant Soil Nitrate Test (PPSN) or soil surface sampling for phosphorus 

accumulation or pH changes.) 

I. Consider ways to modify the chemistry of animal manure, including modification of the 

animal’s diet to reduce the manure nutrient content, to enhance the producer’s ability to 

manage manure effectively. 

VI. Implementation 

A. A new source CAFO shall attain implementation of this technical standard as of the date 

the NPDES permit is issued. 

B. An existing CAFO shall attain implementation of this technical standard according to a 

schedule identified by the permitting authority. The schedule for implementation of this 

technical standard shall not extend beyond December 31, 2006. 

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APPENDIX P - CALCULATIONS FOR ESTIMATING MEDIAN ANNUAL OVERFLOW 

VOLUMES AND ANNUAL AVERAGE DISCHARGE OF POLLUTANTS 

The methodology for estimating overflows is presented in the following seven steps: 

1. Each day over the 25-year period, EPA subtracts the evaporation from the precipitation to 

calculate the net precipitation. The net precipitation is multiplied by the pond surface area to get a 

net precipitation volume for the pond. 

Net Precipitation (in) = Precipitation (in) - Evaporation (in) 

Net Precipitation Volume (cf) = [Net Precipitation (in) * Pond Surface Area (sf)] / 12 (in / ft) 

2. The runoff volume is calculated by subtracting 0.5 inches of infiltration from the daily precipitation 

and multiplying by the drylot runoff area. If precipitation less the infiltration is less than zero, the 

runoff is assumed to be zero. 

Runoff Volume (cf) = [Precipitation (in) - Infiltration (in)] * Runoff Area (sf) / 12 (in/ft) 

Where: Infiltration = 0.5 in 

3. The daily volume of the pond is calculated by summing the net precipitation volume, the runoff 

volume, and the previous day’s pond volume. 

Daily Pond Volume (cf) = Net Precipitation Volume (cf) + Runoff Volume (cf) + Previous 

Volume (cf) 

The minimum pond volume is equal to the accumulated solids volume plus the minimum treatment 

volume. If there is no precipitation, the net precipitation volume will be negative and the runoff 

volume will be assumed to be zero. However, the pond volume can not be less than the 

accumulated solids volume. Therefore, anytime a net precipitation volume loss results in the daily 

pond volume being less than the accumulated solids volume plus the minimum treatment volume, 

EPA assumes the daily pond volume is equal to the maximum accumulated solids volume plus the 

minimum treatment volume. 

4. During the freeze-free period, EPA assumes liquid from the pond is applied to crop land at a 

specified period (e.g., every 7 days, every 30 days, every 180 days). 

Applications (applications / yr) = Freeze Free Days (days / yr) / Days Between Application 

(days / application) 

5. The amount of liquid per application is assumed to be equal to the estimated daily flow into the 

pond (from the cost model) multiplied by 365 days and divided by the number of annual 

applications. 

Liquid per Application (cf / application) = Estimated Daily Flow (cf / day) * 365 (days) / 

Applications (applications / yr) 

6. EPA uses freeze free days to estimate a start day for application. The pond volume is never 

allowed to drop below the sludge volume plus the minimum treatment volume. If the application 

volume is greater than the volume available in the pond, EPA assumes all available liquid is 

applied. 

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Daily Pond Volume (cf) = Net Precipitation Volume (cf) + Runoff Volume (cf) + Previous 

Volume (cf) - Application Volume (cf) 

7. The pond volume for each day in the 25-year period is calculated. When the daily pond volume is 

greater than the maximum pond volume, EPA assumes an overflow equal to the daily pond 

volume less the maximum pond volume occurs. The pond volume is then set equal the maximum 

pond volume. 

Overflow (cf) = Daily Pond Volume (cf) - Maximum Pond Volume (cf) 

Daily Pond Volume (cf) = Maximum Pond Volume (cf) 

Example for KT Pork Producers, Dubuque, IA 

KF Pork Producers (KFP) is located in Dubuque County, Iowa. EPA uses 25-year daily precipitation and 

evaporation data from the Centerville, Iowa weather station to represent the climate of this county. The 

Centerville weather station is the closest weather station to Dubuque County, Iowa with readily available 

25-year climate data. The climate data begins January 1, 1970 and ends December 31, 1995. 

On January 1, 1970, KFP assumes the volume of was in the pond is equal to the sludge volume plus the 

minimum treatment volume which is 1,206,083 cubic feet (cf). It is assumed that the pond volume is never 

less than the accumulated solids volume plus the minimum treatment volume. 

On January 2, 1970, the Centerville weather station reports 0.00 inches of precipitation and 0.0778 inches 

of evaporation. The daily pond volume is calculated as: 

Daily Pond Volume (cf) = Net Precipitation Volume (cf) + Runoff Volume (cf) + Previous 

Volume (cf) 

Where: Net Precipitation Volume (cf) = (0.00 - 0.0778) * 157,272 / 12 = -1020 cf 

Runoff Volume = 0 

Previous Volume = 1,206,083 

Daily Pond Volume = -1020 + 0 + 1,206,083 = 1,205,063 cf 

KFP applies liquids in the holding lagoon to crop land every 7 days during the freeze free period between 

April 21 and September 14, provided that there has been no significant precipitation during the 3 days 

prior to the day of application. If there has been significant precipitation, the application date is moved to 

the next available date. In some cases this may mean that the weekly application may not occur. 

The freeze free period for Dubuque County, Iowa is 147 days from April to September. This results in 21 

applications per year. 

Applications (applications / yr) = Freeze Free Days (days / yr) / Days Between Application 

(days / application) 

Where: Freeze Free Days = 147 

Days Between Application = 7 

Applications = 147 / 7 = 21 applications / year 

Liquid per Application (cf / application) = Estimated Daily Flow (cf / day) * 365 (days) / 

Applications (applications / yr) 

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Where: Estimated Daily Flow = 8,356 cf/day 

Liquid per Application = 8,356 * 365 / 21 = 145,235 (cf / application) 

KFP’s first day of application is April 21, 1970. In addition to adding the net precipitation and runoff 

volume to the previous volume, the application volume is subtracted April 21 and roughly every seventh 

day afterward until there are 21 applications. When overflow is calculated, the volume of the overflow is 

subtracted from the previous days pond volume. 

On April 21, 1970, there is no precipitation and 0.349 inches of evaporation for Centerville, Iowa. 

Daily Pond Volume (cf) = Net Precipitation Volume (cf) + Runoff Volume (cf) + Previous 

Volume (cf) - Application Volume (cf) 

Where: Net Precipitation Volume (cf) = (0 - 0.349) * 157,272 / 12 = -4,574 cf 

Runoff Volume = 0 

Previous Volume = 776,594 

Application Volume = 145,235 

Daily Pond Volume = -4,574 + 0 + 776,594 - 145,235 = 626,785 cf 

EPA estimates an average annual overflow for KFP to be 158,419 cf or 1,184,970 gal/yr over the 25-year 

period. 

Using sampling data, the annual pollutant discharges are calculated by multiplying the overflow volume by 

the concentration: 

Pollutant discharge (lbs/yr) = Pollutant concentration (mg/L) * 3.785 L/gal * Overflow volume 

(gal/yr) * 2.2 lbs/kg * 1 kg/106

 mg 

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