&EPA
            United States
            Environmental Protection
            Agency
            Office of Research and
            Development
            Washington, DC 20460
EPA/625/R-95/001
September 1995
Process Design Manual
Land Application of
Sewage Sludge and
Domestic Septage

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                                              EPA/625/R-95/001
                                               September 1995
         Process Design Manual

Land Application of Sewage Sludge and
            Domestic Septage
         U.S. Environmental Protection Agency
         Office of Research and Development
     National Risk Management Research Laboratory
     Center for Environmental Research Information
                Cincinnati, Ohio

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                                        Notice
This document has been reviewed in accordance with the U.S. Environmental Protection Agency's
peer and administrative review policies and approved for publication. Mention of trade  names or
commercial products does not constitute endorsement or recommendation for use.

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                                              Contents
                                                                                                Page
Chapter 1   Introduction
            1.1   Overview	  1
            1.2   Sewage Sludge Regulations	  1
            1.3   Objectives of Manual	  2
            1.4   Scope of Manual	  3
Chapter 2   Overview of Sewage Sludge Land Application Practices
            2.1   Introduction	  5
            2.2   Application to Agricultural Lands	  5
                 2.2.1   Purpose and Definition	  5
                 2.2.2   Advantages  of Agricultural Land Application	  5
                 2.2.3   Limitations of Agricultural Land Application	  7
            2.3   Application to Forest Lands	  7
                 2.3.1   Purpose and Definition	  7
                 2.3.2   Advantages  of Forest Land Application	  7
                 2.3.3   Limitations of Forest Land Application	  8
            2.4   Land Application at Reclamation Sites	  8
                 2.4.1   Purpose and Definition	  8
                 2.4.2   Advantages  of Land Application at Reclamation Sites	  9
                 2.4.3   Limitations of Land Application at Reclamation Sites	  9
            2.5   Land Application at Public Contact Sites,  Lawns, and Home Gardens	  9
                 2.5.1   Purpose and Definition	  9
                 2.5.2   Advantages  of Land Application at Public Contact Sites, Lawns, and
                        Home Gardens	  9
                 2.5.3   Limitations of Land Application at Public Contact  Sites, Lawns, and Home
                        Gardens	  10
            2.6   References	  10
Chapter 3   Overview of the Part 503 Regulatory Requirements for Land Application of
            Sewage Sludge
            3.1   General	  11
            3.2   Pollutant Limits	  11
                 3.2.1   Ceiling Concentration Limits	  12

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                3.2.2   Pollutant Concentration Limits	  13
                3.2.3   Cumulative Pollutant Loading Rates (CPLRs)	  13
                3.2.4   Annual Pollutant Loading  Rates (APLRs)	  14
                3.2.5   Why Organic Pollutants Were Not Included in Part 503	  14
            3.3  Management Practices	  14
            3.4  Operational Standards for Pathogens and Vector Attraction Reduction	  15
                3.4.1   Pathogen Reduction Requirements	  15
                3.4.2   Vector Attraction Reduction Requirements	  20
            3.5  Frequency of Monitoring	  22
            3.6  Recordkeeping and Reporting	  22
            3.7  Sewage Sludge Quality and the Part 503 Requirements	  22
                3.7.1   Exceptional Quality  (EQ) Sewage Sludge	  22
                3.7.2   Pollutant Concentration (PC) Sewage Sludge	  24
                3.7.3   Cumulative Pollutant Loading Rate (CPLR) Sewage Sludge	  24
                3.7.4   Annual Pollutant Loading  Rate (APLR) Sewage Sludge	  24
            3.8  References	  26
Chapter 4   Characteristics of Sewage Sludge
            4.1  Introduction	  27
            4.2  Sewage Sludge Quantity	  27
            4.3  Total Solids Content	  29
            4.4  Volatile Solids Content	  29
            4.5  pH	  29
            4.6  Organic Matter	  29
            4.7  Pathogens	  31
            4.8  Nutrients	  32
                4.8.1   Nitrogen	  32
                4.8.2   Phosphorous,  Potassium, and Other Nutrients	  33
            4.9  Metals	  33
            4.10 Organic Chemicals	  34
            4.11 Hazardous Pollutants (If Any)	  34
            4.12 Types  of Sewage Sludge	  35
                4.12.1   Primary Sewage Sludge	  35
                4.12.2   Secondary Sewage  Sludge	  35
                4.12.3   Tertiary Sewage Sludge	  35
                4.12.4   Domestic Septage	  35

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            4.13 Effects of Wastewater and Sludge Treatment Processes on Sewage Sludge
                 Characteristics	  35
            4.14 Effects of Pretreatment and Pollution Prevention Programs on Sewage Sludge
                 Characteristics	  37
            4.15 References	  37
Chapter 5   Site Evaluation and Selection Process
            5.1  General	  39
            5.2  Part 503 Requirements	  39
                 5.2.1    Protection of Surface Water and Wetlands	  39
                 5.2.2   Protection of Threatened and Endangered Species	  40
                 5.2.3   Site Restrictions	  40
            5.3  Planning and Selection Process	  41
            5.4  Preliminary Planning	  41
                 5.4.1    Institutional and Regulatory Framework	  41
                 5.4.2   Public Participation 	  41
                 5.4.3   Preliminary Land Area Requirements	  41
                 5.4.4   Sewage Sludge Transport Assessment	  41
            5.5  Phase I Site Evaluation  and Site Screening	  43
                 5.5.1    Existing Information Sources	  43
                 5.5.2   Land Use and Availability	  44
                 5.5.3   Physical Characteristics of Potential Sites	  46
                 5.5.4   Site Screening	  49
            5.6  Phase II Site Evaluation: Field Investigation	  49
            5.7  Selection  of Land Application Practice	  50
            5.8  Final Site Selection	  50
                 5.8.1    Preliminary Cost Analysis	  50
                 5.8.2   Final Site Selection	  50
            5.9  Site Selection Example	  53
                 5.9.1    City Characteristics	  53
                 5.9.2   Sewage Sludge and Soil Characteristics	  53
                 5.9.3   Regulations Considered	  53
                 5.9.4   Public Acceptance	  54
                 5.9.5   Preliminary Feasibility Assessment	  54
                 5.9.6   Estimate  Land Area Required	  54
                 5.9.7   Eliminate Unsuitable Areas	  54

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                 5.9.8    Identify Suitable Areas	  55
                 5.9.9    Phase II Site Survey and Field Investigation	  56
                 5.9.10  Cost Analysis	  56
                 5.9.11   Final  Site Selection	  56
            5.10 References	  56
Chapter 6   Phase II Site Evaluation
            6.1  General	  57
            6.2  Preliminary Field Site Survey	  57
            6.3  Site-Specific Field Investigations	  58
                 6.3.1    Base Map Preparation	  58
                 6.3.2    Field  Checking of Surface Features and Marking Buffer Zones on
                         the Base Map	  58
                 6.3.3    Identifying Topographic Limitations	  59
                 6.3.4    Field  Soil Survey	  59
                 6.3.5    Delineation of Floodplains and Wetlands	  60
                 6.3.6    Site Hydrogeology	  60
            6.4  Soil Sampling and Analysis to Determine Agronomic Rates	  61
                 6.4.1    Part 503 Definition of Agronomic Rate	  61
                 6.4.2    Soil Sampling	  61
            6.5  Special Considerations for Reclamation Sites	  61
                 6.5.1    Sampling and Analysis of Disturbed Soils	  62
            6.6  References	  62
Chapter 7   Process Design for Agricultural Land Application Sites
            7.1  General	  63
            7.2  Regulatory Requirements and Other Considerations	  63
                 7.2.1    Nitrogen and Other Nutrients	  63
                 7.2.2    Soil pH and Requirements for pH Adjustment	  64
                 7.2.3    Special Considerations for Arid Lands	  65
            7.3  Application Methods  and Scheduling	  65
                 7.3.1    Application Methods	  65
                 7.3.2    Scheduling	  67
                 7.3.3    Storage	  68
            7.4  Determining Sewage Sludge Application  Rates for Agricultural Sites	  68
                 7.4.1    Part 503 Agronomic Rate for N and Pollutant Limits for Metals	  68
                 7.4.2    Crop  Selection and Nutrient Requirements	  69
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                 7.4.3   Calculating Residual N, P, and K	  69
                 7.4.4   Calculation of Annual Application Rates	  72
                 7.4.5   Calculation of Supplemental N, P, and  K Fertilizer	  81
                 7.4.6   Use of Computer Models To Assist in Determining Agronomic Rates	  81
            7.5  Design Example of Sewage Sludge Application Rate Calculations	  82
                 7.5.1   Calculation of Agronomic N Rate for Each Field	  82
                 7.5.2   Calculation of Long-Term Pollutant Loadings and Maximum Sewage
                        Sludge Quantities	  83
                 7.5.3   Calculation of Agronomic P Rate for Each Field	  84
                 7.5.4   Calculation of Supplemental K Fertilizer To Meet Crop Nutrient Requirements . .  90
                 7.5.5   Additional Considerations for Land Application Program Planning	  91
            7.6  References	  91
Chapter 8   Process Design for Forest Land Application Sites
            8.1  General	  95
            8.2  Regulatory  Requirements and Other Considerations	  95
                 8.2.1   Pathogens	  95
                 8.2.2   Nitrogen Dynamics	  96
            8.3  Effect of Sewage Sludge Applications on Tree  Growth and Wood Properties	  96
                 8.3.1   Seedling  Survival	  96
                 8.3.2   Growth Response	  96
                 8.3.3   Wood Quality	  96
            8.4  Effect of Sewage Sludge Application on  Forest Ecosystems	  96
            8.5  Forest Application Opportunities	  97
                 8.5.1   Forest Stand Types	  97
                 8.5.2   Christmas Tree Plantations	  99
            8.6  Equipment for Sewage Sludge Application at Forest Sites	  99
                 8.6.1   Transfer Equipment	  99
                 8.6.2   Application Equipment	  99
            8.7  Scheduling	  100
            8.8  Determining Sewage Sludge Application Rates for Forest Sites	  100
                 8.8.1   General	  100
                 8.8.2   Nitrogen Uptake and Dynamics in Forests	  100
                 8.8.3   Calculation Based on  Nitrogen for a  Given Year	  103
                 8.8.4   Calculation of Sewage Sludge Application  Rates for First and Subsequent
                        Years	  104
                 8.8.5   Calculation Based on  Part  503 Pollutant Limits for Metals	  104

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            8.9   Design Example of Sewage Sludge Application at Forest Sites	  104
                 8.9.1   Sewage Sludge Quantity and Quality Assumptions	  104
                 8.9.2   Site Selection	  104
                 8.9.3   Determining the Sewage Sludge Application Rate Based on Nitrogen	  105
                 8.9.4   Site Capacity Based on Nitrogen	  106
            8.10 References	  107
Chapter 9   Process  Design for Land Application at Reclamation Sites
            9.1   General	  109
            9.2   Consideration of Post-Sewage  Sludge Application Land Use	  110
                 9.2.1   Mining Regulations	  110
            9.3   Nutrients, Soil pH, and  Climate Considerations	  112
                 9.3.1   Nutrients	  112
                 9.3.2   Soil pH and pH Adjustment	  113
                 9.3.3   Factors Affecting Crop  Yields at Reclamation Sites	  113
                 9.3.4   Special Considerations for Arid Lands	  113
            9.4   Vegetation Selection	  113
                 9.4.1   General	  113
                 9.4.2   Seeding and Mulching	  118
            9.5   Sewage Sludge Application Methods	  118
                 9.5.1   Transportation	  118
                 9.5.2   Site Preparation Prior to Sewage Sludge Application	  119
                 9.5.3   Methods of Application	  119
                 9.5.4   Storage	  119
            9.6   Scheduling	  119
            9.7   Determining Sewage Sludge Application Rates at Reclamation Sites	  120
                 9.7.1   General Information	  120
                 9.7.2   Approach for Determining a Single, Large Application of Sewage Sludge at a
                        Reclamation  Site	  120
                 9.7.3   Design Example for a Single, Large Sewage Sludge Application at a
                        Reclamation  Site	  121
            9.8   References	  122
Chapter 10  Land Application at Public Contact Sites, Lawns, and Home Gardens
            10.1 General	  125
            10.2 Part 503 Requirements	  125
            10.3 Marketing of Sewage Sludge	  125

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                 10.3.1  Developing Product Demand	  126
                 10.3.2  Marketing Cost Considerations	  126
            10.4 References	  127
Chapter 11  Land Application of Domestic Septage
            11.1  General	  129
                 11.1.1  Definition of Domestic Septage	  129
                 11.1.2  Domestic Septage Versus Industrial/Commercial Septage	  130
            11.2 Regulatory Requirements for Land Application of Domestic Septage	  130
                 11.2.1  Determining Annual Application Rates for Domestic Septage at Agricultural
                        Land, Forests, or Reclamation Sites	  130
                 11.2.2  Pathogen Reduction Requirements	  131
                 11.2.3  Vector Attraction Reduction Requirements	  131
                 11.2.4  Certification Requirements for Pathogen and Vector Attraction Reduction	  132
                 11.2.5  Restrictions on Crop Harvesting, Animal Grazing, and Site Access	  133
                 11.2.6  Recordkeeping and Reporting	  133
                 11.2.7  Part 503 Required Management Practices	  134
                 11.2.8  State  Requirements for  Domestic Septage	  134
            11.3 Adjusting the pH of Domestic Septage	  134
                 11.3.1  Sampling for pH	  135
            11.4 Methods of Application	  136
            11.5 Operation and Maintenance at Land Application Sites Using Domestic Septage	  137
            11.6 References	  138
Chapter 12  Public Participation
            12.1 Introduction	  139
            12.2 Objectives	  139
            12.3 Implementation of a Public Participation Program	  139
                 12.3.1  Initial  Planning Stage	  140
                 12.3.2  Site Selection Stage	  143
                 12.3.3  Site Design Stage	  143
                 12.3.4  Site Preparation and Operation Stage	  144
            12.4 Special Considerations	  144
                 12.4.1  Agricultural Sites	  144
                 12.4.2  Forest Sites	  145
                 12.4.3  Reclamation Sites	  145
            12.5 References	  145

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Chapter 13  Monitoring and Sampling
            13.1 Overview	 147
            13.2 Sewage Sludge Monitoring and Sampling	 147
                13.2.1 Sampling Location	 147
                13.2.2 Frequency of Monitoring	 149
                13.2.3 Sample Collection	 150
                13.2.4 Analytical Methods	 150
            13.3 Soil Monitoring and Sampling	 150
                13.3.1 Sampling Location and  Frequency	 152
                13.3.2 Number of Samples	 152
                13.3.3 Sample Collection	 152
                13.3.4 Analytical Methods	 153
            13.4 Surface-Water and Ground-Water Monitoring	 154
                13.4.1 Surface-Water Monitoring	 154
                13.4.2 Ground-Water Monitoring	 154
            13.5 Vegetation  Monitoring	 154
            13.6 Monitoring  and Sampling at Reclamation Sites	 154
                13.6.1 General	 154
                13.6.2 Disturbed Soil Sampling Procedures	 154
                13.6.3 Suggested Monitoring Program	 155
            13.7 References	 156
Chapter 14  General Design Considerations
            14.1 Introduction	 157
            14.2 Transportation of Sewage Sludge	 157
                14.2.1 Transport Modes	 157
                14.2.2 Vehicle Transport	 157
                14.2.3 Pipeline Transport	 163
                14.2.4 Other Transport Methods	 167
            14.3 Storage of Sewage Sludge	 168
                14.3.1 Storage Requirements	 168
                14.3.2 Storage Capacity	 168
                14.3.3 Location of Storage	 170
                14.3.4 Storage Design	 170
            14.4 Land  Application Methods	 171
                14.4.1 Overview	 171

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                 14.4.2 Application of Liquid Sewage Sludge	  171
                 14.4.3 Application of Dewatered Sewage Sludge	  175
            14.5  Site Preparation	  177
                 14.5.1 General	  177
                 14.5.2 Protection of Ground Water and Surface Water Quality	  177
                 14.5.3 Grading	  178
                 14.5.4 Erosion Control	  178
            14.6  Design of Supporting Facilities	  178
                 14.6.1 Access Roads	  178
                 14.6.2 Public Access: Site Fencing and Security	  178
                 14.6.3 Equipment and Personnel Buildings	  179
                 14.6.4 Lighting and Other Utilities	  179
            14.7  References	  179
Chapter 15  Management, Operational Considerations, and Recordkeeping and Reporting
            15.1  Sewage Sludge Management Plans	  181
            15.2  Part 503 Requirements Affecting Land Application Site Operation	  181
            15.3  Nuisance  Issues	  181
                 15.3.1 Odor	  183
                 15.3.2 Spillage	  183
                 15.3.3 Mud	  183
                 15.3.4 Dust	  183
                 15.3.5 Noise	  184
                 15.3.6 Road Maintenance	  184
                 15.3.7 Selection of Haul Routes	  184
            15.4  Safety Concerns	  184
                 15.4.1 Training	  184
            15.5  Health Concerns	  185
                 15.5.1 General	  185
                 15.5.2 Personnel Health Safeguards	  185
            15.6  Recordkeeping and Reporting	  185
                 15.6.1 General	  185
                 15.6.2 Part 503 Recordkeeping Requirements for Preparers of Sewage Sludge	  185
                 15.6.3 Part 503 Requirements for Appliers of Sewage Sludge	  192
                 15.6.4 Notification Requirements for Preparers and Appliers of Sewage Sludge	  192
                 15.6.5 Notice of Interstate Transport	  194

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                 15.6.6 Notification by Appliers	  194
                 15.6.7 Annual Reports	  194
            15.7  References	  195
Chapter 16  Cost Estimate Guidance for Land Application Systems
            16.1  Introduction	  197
                 16.1.1 Information Needed Prior to Using Cost Algorithms	  197
                 16.1.2 Economic Variables	  197
                 16.1.3 Total Base Capital Cost Estimates	  198
                 16.1.4 Total Annual O&M Cost Estimates	  198
                 16.1.5 Calculating Cost Per Dry Ton	  198
            16.2  Agricultural Land Application	  198
                 16.2.1 General Information and Assumptions Made	  198
                 16.2.2 Process Design and Cost Calculations	  199
            16.3  Application to Forest Lands	  203
                 16.3.1 General Information and Assumptions Made	  203
                 16.3.2 Process Design and Cost Calculations	  203
            16.4  Land  Application at Reclamation Sites	  207
                 16.4.1 General Information and Assumptions Made	  207
                 16.4.2 Process Design and Cost Calculations	  207
            16.5  Transportation of Sewage  Sludge	  211
                 16.5.1 Truck Hauling of Liquid Sewage Sludge	  211
                 16.5.2 Truck Hauling of Dewatered Sewage Sludge	  214
                 16.5.3 Long-Distance Pipeline Transport of Liquid Sewage Sludge	  217
            16.6  Example of Preliminary Cost Estimation for Agricultural Land Application to
                 Cropland	  220
                 16.6.1 Process Design and Cost Calculations	  220
            16.7  References	  223
Appendix A Case Studies	  225
Appendix B Federal Sewage Sludge Contacts	  283
Appendix C Permit  Application Requirements	  285
Appendix D Conversion Factors	  287
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                                               Figures
Figure                                                                                            Page

1-1     Overview of the Part 503 rule's land application requirements	 2
1-2    Suggested sequence for manual use	 4
4-1     Generation, treatment, use, and disposal of sewage sludge and domestic septage	  28
5-1     Simplified planning steps for a sewage sludge land application system	  40
5-2    Institutional framework	  42
5-3    Planning, site selection, and land application practice selection sequence	  51
5-4    General area map with concentric rings	  54
5-5    General soil map showing area selected for sewage  sludge land application	  54
5-6    Detailed soil survey map of potential site for sewage sludge land application	  56
7-1     Determining mineralized PAN from previous sludge applications	  75
7-2    Determining agronomic N  rate	  77
7-3    Worksheet 1 calculations to determine residual N credits for previous sewage sludge applications...  85
7-4    Calculation  of the agronomic N rate for the wheat field	  86
7-5    Calculation  of the agronomic N rate for the corn field	  88
11-1    Part 503 pathogen reduction Alternative 1 for domestic septage (without additional treatment)
       applied to agricultural land, forests, or reclamation sites	  132
11-2    Part 503 pathogen reduction Alternative 2 for domestic septage (with pH treatment) applied to
       agricultural  land, forests, or reclamation sites	  132
11-3    Part 503 vector attraction reduction options for domestic septage applied to agricultural land,
       forests, or reclamation sites	  133
11-4    Certification of pathogen reduction and vector attraction requirements	  133
11-5    Part 503 5-year recordkeeping requirements	  133
11-6    Procedure for lime-stabilizing domestic septage within the pumper truck	  136
11-7    Subsurface soil injection	  136
14-1    Examples of sewage sludge transportation modes to land  application sites	  158
14-2a  A6,500-gallon liquid sludge tank truck	  158
14-2b  A3,300-gallon liquid sludge tank truck with 2,000-gallon pup trailer	  158
14-2c  A 25-cubic-yard dewatered sludge haul truck	  159
14-2d  A 12-cubic-yard dewatered sludge spreader vehicle	  159
14-3   Hydraulic characteristics of sludge solids	  164
14-4   Storage days required as estimated from the use of the EPA-1 computer program for
       wastewater-to-land systems	  169
14-5   Example of mass flow diagram using cumulative generation and cumulative sludge
       application to estimate storage requirement	  170
14-6   Splash plates on back of tanker truck	  172
14-7   Slotted T-bar on back of tanker truck	  172
14-8   Tank truck with side spray nozzle for liquid sludge surface application	  172

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                                               Figures

Figure                                                                                          Page

14-9   Tank truck with liquid sludge tillage injectors	 174
14-10  Tank truck with liquid sludge grassland injectors	 174
14-11   Tractor-pulled liquid sludge subsurface injection unit connected to delivery hose	 174
14-12a Tank wagon with sweep shovel injectors	 175
14-12b Sweep shovel injectors with covering spoons mounted on tank wagon	 175
14-13  Center pivot spray application system	 176
14-14  Traveling gun sludge sprayer	 176
14-15  Diagram of liquid sludge spreading system  in forest land utilizing temporary storage ponds	 176
14-16  A 7.2-cubic-yard dewatered sludge spreader	 177
14-17  Large dewatered sludge spreader	 177
14-18  Example of a disk tiller	 177
14-19  Example of a disk plow	 177
15-1   Sludge Management Plan	 182
15-2   Restrictions  for the harvesting of crops and turf, grazing of animals, and public access on sites
       where Class B  biosolids are applied	 182
15-3   Examples of crops impacted by site restrictions for Class B sewage sludge	 182
15-4   Required records for preparers of sewage sludge to document sampling and analysis	 187
15-5   Certification statement required for recordkeeping	 187
15-6   Pathogen reduction alternative 3—analysis and operation	 189
15-7   Notice and necessary information	 193
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                                               Tables
Table                                                                                          Page

1-1     Quantity of Sewage Sludge Generated Annually by Use or Disposal Practice	 1
2-1     Summary of Typical Characteristics of Sewage Sludge Land Application Practices	 6
3-1     Types of Sludge, Septage, and Other Wastewater Solids Excluded From Coverage Under Part 503 .  12
3-2     Definitions of Terms Under the Part 503 Rule	  12
3-3     Who Must Apply for a Permit?	  13
3-4     Part 503 Land Application Pollutant Limits for Sewage Sludge	  13
3-5     Part 503 Land Application Management Practices	  14
3-6     Summary of Class A and Class B Pathogen Alternatives	  15
3-7     Pathogen  Requirements for All Class A Alternatives	  16
3-8     The Four Time-Temperature Regimes for Pathogen Reduction Under Class A, Alternative 1	  16
3-9     Processes To Further Reduce Pathogens  Listed in the Part 503 Rule	  17
3-10   A Partial List of Processes Recommended as Equivalent to PFRP Under Part 257	  18
3-11    Restrictions for the Harvesting of Crops and Turf, Grazing of Animals, and Public Access on Sites
       Where Class B Sewage Sludge is Land Applied	  18
3-12   Processes to Significantly Reduce Pathogens (PSRPs) Listed in Part 503	  19
3-13   Selected Processes Recommended as Equivalent to PSRP  Under Part 2571	  19
3-14   Summary of Vector Attraction Reduction Requirements for Land Application of Sewage Sludge
       Under Part 503	  20
3-15   Frequency of Monitoring for Pollutants, Pathogen Densities,  and Vector Attraction Reduction	  23
3-16   Summary of Part 503 Requirements for Different Types of Sewage Sludge	  23
3-17   Part 503 Land Application General Requirements	  25
3-18   Procedure to Determine the Annual Whole Sludge Application Rate for Sewage Sludge Sold or
       Given Away in a Bag or Other Container for Application to Land	  26
4-1     Effects of  Sewage Sludge Treatment Processes on Land Application Practices  	  30
4-2     Principal Pathogens of Concern in Municipal Wastewater and Sewage Sludge	  31
4-3     Typical Pathogen Levels in Unstabilized and Anaerobically Digested Liquid Sludges 	  31
4-4     Nutrient Levels Identified in Sewage Sludge	  32
4-5     Mean Concentrations of Metals in Sewage Sludge Compared to Part 503
       Ceiling Concentration Limits	  33
4-6     Analytical  Classification and  Limits for TCLP Constituents	  34
4-7     Chemical  and Physical Characteristics of Domestic Septage	  35
4-8     Nutrient Levels in Sewage Sludge From Different Treatment Processes	  36
5-1     Preliminary Estimates of Sewage Sludge Applications (Dry Weight) for Different Types of Land	43
5-2     Sewage Sludge Solids Content and  Handling Characteristics	  43
5-3     Transport  Modes for Sewage Sludge	  43
5-4     Auxiliary Facilities for Sewage Sludge Transport	  44

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                                               Tables

Table                                                                                          Page

5-5    Evaluation of Sewage Sludge Transport Modes	 44
5-6    Suggested Provisions of Contracts Between Sewage Sludge Preparer, Sludge Applier,
       and Private Landowners	 47
5-7    Potentially Unsuitable Areas for Sewage Sludge Application	 47
5-8    Recommended Slope Limitations for Land Application of Sewage Sludge	 47
5-9    Soil Limitations for Sewage Sludge Application to Agricultural Land at Nitrogen Fertilizer
       Rates in Wisconsin	 48
5-10   Recommended Depth to Ground Water	 48
5-11    Potential Impacts of Climatic Regions on Land Application of Sewage Sludge)	 49
5-12   Example Design Features Checklist/Comparison of Candidate Land Application Practices	 52
5-13   Relative Ranking for Forest Sites for Sewage Sludge Application	 53
5-14   Cost Factors To Be Considered During Site Selection	 53
5-15   Ranking of Soil Types for Sewage Sludge Application	 55
6-1    Basic Site-Specific Information Needed for Land Application of Sewage Sludge	 57
6-2    Sample Form for Preliminary Field Site Survey	 58
6-3    Types of Data Available on SCS Soil Series Description and Interpretation Sheets	 59
7-1    Summary of Research on Sewage Sludge Application to Rangeland	 66
7-2    General Guide to Months Available for Sewage Sludge Application for Different Crops in
       North Central States	 67
7-3    Representative Fertilizer Recommendations for Corn and Grain Sorghum in the Midwest	 70
7-4    Representative Fertilizer Recommendations for Soybeans in the Midwest	 70
7-5    Representative Fertilizer Recommendations for Small Grains in the Midwest	 71
7-6    Representative Fertilizer Recommendations for Forages in the Midwest	 71
7-7    Estimated Mineralization Rates (K^) for Different Sewage Sludges	 72
7-8    Volatilization Losses of NH4-N  as NH3	 74
7-9    Part 503 Cumulative  Pollutant  Loading Rate (CLPR) Limits	 80
7-10   Amounts of Pollutants Added by Sewage Sludge in Design Example	 84
8-1    Sewage Sludge Application to  Recently Cleared Forest Sites	 97
8-2    Sewage Sludge Application to  Young Forest Plantations (Over 2 Years Old)	 98
8-3    Sewage Sludge Application to  Closed Established Forest (Over 10 Years Old)	 98
8-4    Comparison of  Different Application  Systems  for Forest Sites	 99
8-5    Monthly Application Schedule for a Design in the Pacific Northwest	 100
8-6    Estimated Annual Nitrogen Removal by Forest Types	 101
8-7    Ranges of Values and Suggested Design Values for Nitrogen Transformations and
       Losses  From Sewage Sludge Applied to Forest Environments	 101
8-8    Example First-year Application Rate for Sewage Sludge Based on Available Nitrogen
       for Two Different Types of Douglas-fir Stands	 103
8-9    N Requirements for Sewage Sludge Application to Hybrid Poplar and Established Douglas-fir
       Plantations	 105
8-10   Sewage Sludge Application Rates to Meet N  Requirements at Forest Sites	 106
8-11    Maximum Annual Sewage Sludge Application Based on N Requirements	 106

                                                 xvi

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                                              Tables

Table                                                                                         Page

9-1     Hectares Under Permit for Surface, Underground, and Other Mining Operations
       From 1977 to 1986	  109
9-2     Number of Hectares Reclaimed With Bonds Released During 1977 to 1986	  109
9-3     Recent Land Reclamation Projects With Municipal Sludge	  111
9-4     Humid Eastern Region Vegetation	  114
9-5     Drier Mid-West and Western Region Vegetation	  115
9-6     Western Great Lakes Region	  115
9-7     Northern and Central Prairies	  115
9-8     Northern Great Plains	  115
9-9     Southern Great Plains	  116
9-10   Southern Plains	  116
9-11    Southern Plateaus	  116
9-12   Intermountain Desertic Basins	  116
9-13   Desert Southwest	  116
9-14   California Valleys	  117
9-15   Some Sucessful Plant Species and Species Mixtures Used in Various Sludge
       Reclamation Projects	  117
10-1    Percent of POTWs Selling Sewage Sludge and Mean Price of Sewage  Sludge Sold	  127
11-1    Characteristics of Domestic Septage: Conventional Parameters	  129
11-2    Characteristics of Domestic Septage: Metals and Organics	  130
11-3    Typical Crop Nitrogen Requirements and Corresponding Domestic Septage Application Rates	  131
11-4    Summary of Domestic Septage Stabilization Options	  135
11-5    Summary of Land Application Methods for Domestic Septage	  137
12-1    Relative Effectiveness of Public Participation Techniques	  140
12-2   Potential Advisory Committee Members	  140
13-1    Monitoring Considerations for Part 503 Requirements	  148
13-2   Sampling Points for Sewage Sludge	  149
13-3   Sewage Sludge Sample Containers, Preservation, and Storage	  151
13-4   Analytical Methods for Sewage Sludge Sampling	  151
13-5   Potential Soil Surface Layer and Subsurface Parameters of Interest	  152
13-6   Suggested Procedures for Sampling Diagnostic Tissue of Crops	  155
14-1    Truck Operation Summary, Liquid Sludge	  160
14-2   Truck Operation Summary, Dewatered  Sludge	  161
14-3   Projected Monthly Sludge Distribution for Agricultural Sludge Utilization  Program,
       Madison, Wisconsin	  162
14-4   Use of Sewage Sludge Pumps	  166
14-5   Surface Application Methods for Liquid  Sewage Sludge	  172
14-6   Subsurface Application Methods for Liquid Sewage Sludge	  174
14-7   Methods and Equipment for Application of Dewatered Semisolid and  Solid  Sludges	  176
15-1    Part 503 Recordkeeping and Reporting Requirements 	  186
15-2   Recordkeeping Recommendations for Class A Pathogen Reduction Alternatives	  188

                                                xvii

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                                               Tables

Table                                                                                          Page

15-3   Recordkeeping Requirements for Class B Pathogen Reduction Alternatives	 190
16-1   Typical Days Per Year of Food Chain Crop Sludge Application	 199
16-2   Capacity and Number of Onsite Mobile Sludge Application Vehicles Required	 200
16-3   Vehicle Load, Unload, and Onsite Travel Time	 200
16-4   Vehicle Sludge Handling Capacity	 200
16-5   Gallons of Fuel Per Hour for Various Capacity Sludge Application Vehicles	 201
16-6   Cost of Onsite Mobile Sludge Application Vehicles 	 202
16-7   Hourly Maintenance Cost  for Various Capacities of Sludge Application Vehicles	 202
16-8   Capacity and Number of Onsite Mobile Sludge Application Vehicles Required	 204
16-9   Vehicle Load, Unload, and Onsite Travel Time	 204
16-10  Vehicle Sludge Handling Capacity	 204
16-11  Gallons of Fuel Per Hour for Various Capacity Sludge Application Vehicles	 205
16-12  Cost of On-Site Mobile Sludge Application Vehicles (1994)	 206
16-13  Hourly Maintenance Cost  for Various Capacities of Forest Land Sludge Application Vehicles	 207
16-14  Typical Truck Unloading Time as a Function of Type of Land Application Used	 211
16-15  Typical Days Per Year of Sludge Hauling as a Function of Types of Application Used and
       Geographical Region	 212
16-16  Number of Vehicles and Capacity of Each Truck	 212
16-17  Fuel Use Capacities for Different Sized Trucks	 212
16-18  Cost of Tanker Truck	 212
16-19  Loading Area Costs Based on Sludge Volume	 213
16-20  Vehicle Maintenance Cost Factors	 213
16-21  Capacity and Number of Haul Vehicles	 214
16-22  Fuel Usage  Values for Different Sized Trucks	 215
16-23  Costs for Different Sized Trucks	 215
16-24  Loading Area Costs	 216
16-25  Vehicle Maintenance Cost Factors	 216
16-26  Factors for Various Sludge Concentrations and Two Types of Sludge	 217
16-27  Head Available from Each Pumping Station	 218
16-28  Annual Labor Per Pump Station	 218
16-29  Pipeline Cost	 219
16-30  Annual Cost of Pumping Station  Parts and Supplies	 220
                                                XVIII

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                                  A cknowledgments
Three groups of participants were involved in the preparation of this manual: (1) the writers, (2) the
technical directors, and (3) the technical reviewers. (Note: This document was originally published
by EPA in 1983; this edition represents a significantly updated revision.) The contractor for this
project was Eastern Research Group, Inc. (ERG), Lexington, Massachusetts, with senior ERG staff
serving as primary writers. Contributing writers provided key information on land application at forest
sites and agricultural sites. The technical advisor was an environmental engineering consultant with
expertise in sewage sludge land application systems, who provided invaluable technical knowledge
throughout the project. Technical direction was provided by U.S. Environmental Protection Agency
(EPA)  personnel from the Center for Environmental Research Information (CERI) in Cincinnati,
Ohio, and the Office of Water in Washington, DC. The technical reviewers were experts in sewage
sludge land application, and included university professors/researchers, consultants, and govern-
ment officials. Each reviewer provided a significant critique of the manual. The people involved in
this project are listed below.
Manual Preparation
Eastern Research Group, Inc. (ERG)
Writers:               Linda Stein, ERG
                      Russell Boulding, ERG
                      Jenny Helmick,  ERG
                      Paula Murphy, ERG
Contributing
Writers:               Charles Henry, University of Washington
                      Lee Jacobs, Michigan State University
Technical Advisor:      Sherwood Reed, Environmental Engineering Consultants
Technical Direction
Project Director:        James  E. Smith, CERI, EPA, Cincinnati, OH
Technical Director:      Robert Southworth, Office of Water, EPA, Washington, DC
Technical Review:
William Sopper, Pennsylvania State University, State College, PA
Robert Brobst, U.S. EPA Region VIM, Denver, CO
Robert Southworth, Office of Water, EPA, Washington, DC
Lee Jacobs, Michigan State University, East Lansing, Ml
Charles Henry, University of Washington, Eatonville, WA
Ronald Crites, Nolte and Associates,  Inc., Sacramento, CA
                                          XIX

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                                               Chapter 1
                                             Introduction
1.1   Overview

Land application of sewage sludge1 generated by domes-
tic sewage treatment is performed in an environmentally
safe and  cost-effective  manner  in many communities.
Land application involves taking advantage of the fertilizing
and soil  conditioning  properties  of sewage sludge by
spreading the sewage sludge on the soil surface, incorpo-
rating or injecting the sewage sludge into soil, or spraying
the sewage sludge. Because sewage sludge disposal
practices (e.g., landfilling) are becoming less available and
more costly, and because of the increasing desire to bene-
ficially reuse waste residuals whenever possible, land ap-
plication is increasingly chosen as a sewage sludge use
or disposal practice.

Approximately  33 percent of the 5.4 million dry  metric
tons of sewage sludge generated annually in the United
States at publicly owned treatment works (POTWs) is
land applied, as shown in Table 1-1. Of the sewage
sludge that is land applied, approximately 67 percent is
land applied on agricultural  lands, 3 percent on forest
lands,  approximately  9 percent on reclamation sites,
and 9 percent on public contact sites; 12 percent  is sold
or given away in a bag or other container for application
to the land (Federal Register, Vol. 58,  No. 32, February
19, 1993). In addition, approximately 8.6 billion gallons
of domestic septage is generated annually.

Land application of sewage sludge has been practiced
in many  countries  for centuries so that the  nutrients
(e.g., nitrogen,  phosphorus) and  organic matter in sew-
age sludge can be  beneficially used to grow  crops or
other vegetation. Over the years, land application has
been  increasingly  managed  to  protect human  health
and the  environment from various potentially harmful
constituents typically found  in  sewage sludge,  such
as  bacteria,  viruses,  and  other pathogens; metals
(e.g., cadmium and  lead); toxic organic chemicals (e.g.,
PCBs); and nutrients (e.g., nitrogen as nitrate). Manage-
 The term "biosolids" has recently gained popularity as a synonym
 for sewage sludge because it perhaps fosters "reuse" potential bet-
 ter than the term "sewage sludge." While this premise may be true,
 this manual does not use the term "biosolids" because the term is
 not defined consistently at this time and because the federal Part
 503 regulation uses the term "sewage sludge."
ment of the land application of sewage sludge has in-
cluded regulatory measures; voluntary and mandatory
pretreatment of wastewater and/or sludge by industry to
improve quality (e.g., lower pollutant levels); and use of
good management practices at land application sites
(e.g., buffer zones, slope restrictions).

1.2   Sewage Sludge Regulations

In 1993, the  U.S.  Environmental  Protection Agency
(EPA) promulgated 40 CFR Part 503 to address the
Clean Water Act's (CWA) requirement that EPA develop
a regulation for the use or disposal of sewage sludge.
The  CWA  required that  this regulation protect  public
health and  the environment from any reasonably antici-
pated adverse effects of pollutants in  sewage sludge.
The  elements of the Part 503 land application standard
are illustrated  in Figure 1-1. The pollutant limits in the
Part 503 rule were based on in-depth risk assessments

Table 1-1. Quantity of Sewage Sludge Generated Annually by
         Use or Disposal Practice (Federal Register,
         February 19, 1993)
POTWs Using a
Use/Disposal
Practice

Use/Disposal
Practice
Land application
Incineration
Co-disposal: Landfill
Surface disposal
Unknown:
Ocean disposal13
Other
Transfer

Number
4,657
381
2,991
1,351
133
3,920
25

Percent
of
POTWs
34.6
2.8
22.2
10.0
1.0
29.1
0.2
Quantity of
Sewage Sludge
Used or Disposed3

Quantity
(1,000
dmt)
1 ,785.3
864.7
1,818.7
553.7
335.5
0
N/A
Percent
of
Sewage
Sludge
33.3
16.1
33.9
10.3
6.3
0.0
N/A
                                                       All POTWs
                                                                         13,458
                                                                                   100.0
                                    5,357.2
                                                                                                     100.0
 Numbers may not add up to 100 percent because of rounding.
b The National Sewage Sludge Survey, on which these figures are
 based, was conducted before the Ocean Dumping Ban Act of 1988,
 which generally prohibited the dumping of sewage sludge into the
 ocean after December 31, 1991. Ocean dumping of sewage sludge
 ended in June 1992.

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                                           General Requirements


                                 Reporting        |          _Pollutant  Limits
                         Recordkeepin<
                               Frequency of
                               Monitoring
                                              Management
                                                Practices
            Operational  Standards
                 Pathogen
                 and Vector
                 Attraction
                 Reduction
Figure 1-1.  Overview of the Part 503 rule's land application requirements.
that investigated the  effects on human health and the
environment of using or disposing sewage sludge. The
pollutant limits and management practices in Part 503
protect human health and the environment, as required
by the CWA.  Another key component of the  rule is
the operational  standard  that  requires reduction  of
pathogens (i.e., disease-causing organisms) and of vec-
tor attraction (e.g., insects, rodents) using specified op-
erational processes  (e.g., treatment), microbiological
monitoring, and physical barriers (e.g., injection or incor-
poration) for sewage sludge to achieve this reduction.
This operational standard, in the judgement of EPA, pro-
tects public health and the environment from pathogens
and vectors. Other parts of the rule (i.e., general require-
ments, frequency of monitoring, recordkeeping, and re-
porting requirements) make the rule self-implementing.

Research has shown that most sewage sludge currently
generated  in the United  States  meets the  minimum
pollutant limits and pathogen reduction requirements set
forth in Part 503, and that some sewage sludge already
meets the most stringent Part 503  pollutant limits and
pathogen and vector attraction reduction requirements.

This manual refers to the Part 503 regulation throughout
the document as it relates to the  specific topic being
discussed (e.g., site selection, design). In addition, this
manual provides a summary of the Part 503 land appli-
cation requirements (Chapters).

State agencies may have their own  rules governing the
use or disposal of sewage sludge or domestic septage.
If this is the  case, or if a state has not  yet adopted
the federal rule,  the generator or preparer of sewage
sludge destined for land application will have to follow
the most restrictive portions of both the federal and state
rules. Users or disposers of sewage sludge or domestic
septage are strongly encouraged to check with the ap-
propriate state sewage  sludge coordinator  to obtain
information on specific and the most up-to-date state
requirements.

1.3   Objectives of Manual

The information in this manual is  intended for use by
municipal  wastewater treatment and sewage sludge
management authorities, project planners and design-
ers, regional, state, and local governments concerned
with  permitting and  enforcement of federal  sewage
sludge regulations, and consultants in  relevant disci-
plines such as engineering, soil science,  and agronomy.
The manual is intended to provide general guidance and
basic information on the planning, design, and operation
of sewage sludge land application projects for one or
more of the following  design practices:

• Agricultural  land application  (crop production,  im-
  provement of pasture and rangeland).

• Forest land application (increased tree growth).

• Land application at reclamation sites (mine spoils,
  construction sites, gravel pits).

• Land application at public contact  sites (such  as
  parks and golf courses), lawns,  and home gardens.

This manual reflects state-of-the art design information
for the land application of sewage sludge. Other EPA
manuals that can serve as useful  supplements to  this
guide  include:

• Environmental Regulations  and  Technology: Control
  of Pathogens  and  Vector Attraction in   Sewage
  Sludge.  1992. Office of Research and Development.
  EPA/625/R-92/013.

• Preparing Sewage Sludge  For  Land  Application Or
  Surface Disposal: A Guide  for Preparers of Sewage
  Sludge on the Monitoring, Record Keeping,  and Re-
  porting Requirements of the Federal Standards for

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  the Use or Disposal of Sewage Sludge, 40 CFR Part
  503.  1993. Office of Water. EPA 831 B-93-002.

• A Plain English Guide to the EPA Part 503 Biosolids
  Rule. 1994. Office  of Wastewater  Management.
  EPA/832/R-93/003.

• Domestic Septage Regulatory Guidance: A Guide to
  the EPA 503 Rule. 1993. Office of Water. EPA 832-
  B-92-005.

• Technical Support Document for Land Application of
  Sewage Sludge. 1992. Vols. I and II. Office of Water.
  EPA  822/R-93-001a. (NTIS  No.: PB93-110583 and
  PB93-110575).

• Process Design Manual: Sludge Treatment and Dis-
  posal. 1979. Office of Research and Development.
  EPA/625/1-79/011.

• Process Design  Manual for Dewatering Municipal
  Wastewater Sludge.  1982. Office of  Research and
  Development. EPA/625/1-82/014.

References are made throughout this  manual to these
and other documents for more detailed  information  on
specific topics relevant to designing  land application
systems. Full citations for all references are provided at
the end  of each chapter.

1.4   Scope of Manual

This manual covers both  regulatory and non-regulatory
aspects  of designing and operating sewage sludge land
application sites. This manual does not discuss the sur-
face disposal of sewage sludge or codisposal of sewage
sludge with municipal solid waste, which is covered in
the Process Design Manual: Surface Disposal of Sew-
age Sludge and Domestic Septage (EPA, 1995,  EPA/
625/R-95/002). This manual also does not discuss incin-
eration of sewage sludge, which is discussed  in the
Technical Support Document for Incineration of Sewage
Sludge (EPA, 1992, NTIS PB93-110617). In  addition,
discussion of industrial sludge, which is regulated  by 40
CFR Part 257,  is  beyond the scope of this manual.

Figure 1-2  presents a suggested sequence to follow
when  using this manual, which may be varied according
to  user needs. The manual consists of 16 chapters and
4 appendices.  The appendices provide case studies,
regional  EPA office information, permit requirements,
and measurement conversions.

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Figure 1-2.  Suggested sequence for manual use.

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                                             Chapter 2
                 Overview of Sewage Sludge Land Application Practices
2.1   Introduction

The sewage sludge land application practices listed in
the previous chapter are not mutually exclusive. For
example, land  reclamation may involve the planting of
trees on sewage sludge-amended soil, and two or more
practices (e.g., land application at agricultural and forest
sites) can be used in a single sewage sludge manage-
ment program. Table 2-1 summarizes the typical  char-
acteristics  of  the  sewage  sludge  land  application
practices covered in this manual.

Each of these practices has advantages and disadvan-
tages in terms of the quality and  quantities of sewage
sludge  that can be utilized and for application  site re-
quirements. This chapter provides an overview of the
land application practices and  highlights their advan-
tages  and disadvantages. Each  practice  is then dis-
cussed  in  greater  detail  in the subsequent  design
chapters. The design chapters present the criteria and
limitations that establish sewage sludge  application
rates in detail.

2.2   Application to Agricultural Lands

2.2.1   Purpose and Definition

Agricultural land application of sewage sludge  is  prac-
ticed in nearly every state, and is especially common in
Colorado, New Jersey, Pennsylvania,  Ohio,  Illinois,
Michigan, Missouri, Wisconsin, Oregon, and Minnesota.
Hundreds of communities, both large  and small,  have
developed successful agricultural land application pro-
grams. These programs benefit the municipality gener-
ating the sewage  sludge by  providing  an ongoing,
environmentally acceptable, and  cost-effective means
of managing sewage sludge; the participating farmer
also benefits by receiving the nutrients in sewage sludge
for crop production, generally at a lower cost than con-
ventional fertilizers.

Sewage  sludge applied to  agricultural  land must be
applied at a rate that is  equal to or less than the "agro-
nomic rate," defined in Part 503 as the rate designed to
provide the amount of nitrogen needed by the  crop or
vegetation while minimizing the amount of nitrogen in
the sewage sludge that will pass below the root  zone of
the crop or vegetation to the ground water. The amount
of available N (or P) applied to the site is based on that
required by the crop. This amount of N would otherwise
be applied to the site as commercial fertilizer by the
farmer. By limiting N loadings to fertilizer recommenda-
tions, the impact on ground water should be no greater
than in agricultural operations using commercial fertiliz-
ers or manure; ground-water impacts may even be less
because  of  Part  503's agronomic rate  requirement.
Chapter 7 of this manual provides details  of agronomic
rate calculations for agricultural sites.


2.2.2  Advantages of Agricultural Land
       Application

Sewage sludge contains several plant macronutrients,
principally N and P, and in most cases, varying amounts
of micronutrients such as boron  (B),  copper (Cu), iron
(Fe), manganese (Mn),  molybdenum (Mo), and  zinc
(Zn). The exact ratio of these nutrients will not be that of
a well-balanced formulated fertilizer; but the nutrients in
sewage sludge can be combined  with nutrients from
other fertilizers to provide the  proper amounts of nutri-
ents needed for crop production.

Sewage sludge can also be a valuable soil conditioner.
The addition of organic materials like  sewage sludge to
a fine-textured clay soil can help make the soil  more
friable  and can  increase the amount of pore space
available for root growth and the entry of water and air
into the soil.  In  coarse-textured sandy soils, organic
residues  like sewage sludge can increase  the water-
holding capacity of the soil and provide chemical sites
for nutrient exchange and adsorption. In some regions
of the country, the water added to the soil during sewage
sludge application also is a valuable resource.

The treatment works generating the sewage sludge can
benefit because in many cases agricultural  land appli-
cation  is less  expensive than alternative methods of
sewage sludge use or disposal. The general public may
benefit from cost savings resulting from agricultural land
application of sewage sludge, and the recycling of nutri-
ents is attractive to citizens concerned with the environ-
ment and resource conservation.

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Table 2-1.  Summary of Typical Characteristics of Sewage Sludge Land Application Practices
Characteristics
Agricultural Land
Application3
Forest Land
Application
                                                                               Land Application at
                                                                               Reclamation Sites
                          Application to Public
                          Contact Sites, Lawns,
                          and Home Gardens
Application rates
Application frequency
Ownership of
application site(s)
Useful life of application
site(s)
Sewage sludge
transport complexity
and cost
Sewage sludge
scheduling
Application constraints
Sludge nutrients
beneficially recycled


Potential benefits to
existing soil condition
Varies; normal range in
dry weight of 2 to 70
t/ha/yr (1 to 30 T/ac/yr)
depending on type of
crops, sewage sludge
characteristics, etc.
Typical rate is 10 t/ha/yr
(5 T/ac/yr).

Typically repeated
annually, usually
scheduled between
harvesting and planting.
Scheduling can be
complex with large
quantities of sludge.

Usually  privately owned
land. Conditions of
application often
covered by a contract
between farmer(s) and
municipality.

Unlimited for sludge
meeting Part 503
pollutant concentration
limits (PCLs,  see
Chapter 3); limited by
accumulated  metal
loadings from total
sludge applied when
sludge does not meet
PCLs—typically 20-100
or more years"

Can be  expensive if
farms are numerous
and long transportation
distances are involved.
Scheduling can be
difficult, because
applications must work
around planting/
harvesting activities and
poor weather conditions.

Usually none when
appropriate application
vehicles are used. May
be limited by cropping
pattern and  Part 503
agronomic rate
management practice
requirement.
Yes. Reduces
commercial fertilizer use.


Depends on existing
soil characteristics and
quantity of sludge used.
Varies; normal range in
dry weight of 10 to 220
t/ha/yr (4 to 100 T/ac/yr)
depending on soil, tree
species, sewage sludge
quality, etc. Typical rate
is about 18 t/ha/yr (8
T/ac/yr).b

Usually applied annually
or at 3- to 5-year
intervals.
Usually owned by
private tree-growing firm
or governmental agency
at state/federal level.
Usually limited by
accumulated metal
loadings in total sewage
sludge applied. With
most sewage sludge, a
useful life  of 20 to 55
years or more is typical.b
Depends on distance to
forest lands and roads
within site.
Scheduling affected by
climate and maturity of
trees.
Can be difficult if limited
access roads and
uneven terrain. May
involve specially
designed application
equipment. May be
limited by Part 503
agronomic rate
management practice
requirement.

Yes. Reduces or
eliminates commercial
fertilizer use.

Depends on existing
soil characteristics.
Varies; normal range in
dry weight of 7 to 450
t/ha/yr (3 to 200
T/ac/yr). Typical rate is
112 t/ha/yr (50 T/ac/yr).
Usually a one-time
application.


Usually a one-time
application.
Usually owned by
mining firm or
governmental agency at
state/federal level.
Usually a one-time
application that helps
revegetate site.
Cumulative pollutant
limits may not be
reached for 13 to 50 or
more years.b
Depends on distance to
disturbed lands.
Scheduling affected by
climate and availability
of new sites.
Usually none, but may
be complicated  by
irregular terrain
common at disturbed
sites.
Yes. Reduces or
eliminates commercial
fertilizer use.

Yes. Allows soil to
support vegetation and
retards erosion.
Varies depending on
end use (e.g., crops,
turf). Typical rate is 18
t/ha/yr (8 T/ac/yr).
Varies depending on
end use.
Usually privately owned;
some public contact
sites (e.g., parks) may
be owned by a
governmental agency.


Varies, possibly 32 or
more years.b
May include conveying
sewage sludge from
wastewater treatment
plant to processing
center, transport  of
bulking materials for
composting, and
distribution of the
finished sewage  sludge.

Varies depending on
end use.
None; similar to surface
application of solid or
semisolid fertilizers,
lime, or animal manure.
Yes. Reduces
commercial fertilizer use.


Depends on existing
soil characteristics and
quantity of sludge used.

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Table 2-1.  Summary of Typical Characteristics of Sewage Sludge Land Application Practices (continued)
Characteristics
Agricultural Land
Application3
Forest Land
Application
                                                                  Land Application at
                                                                  Reclamation Sites
                      Application to Public
                      Contact Sites, Lawns,
                      and Home Gardens
Dramatic improvement
in vegetative growth
response
Existing projects using
this practice


Availability of technical
literature pertaining to
this practice
May improve
production; generally
replaces some
commercial fertilizer
nutrients.

Hundreds of large and
small full-scale projects.


Extensive.
Yes. Projects show
large positive impact.
A moderate number of
full-scale and
demonstration projects.

Moderate.
Yes. Projects show
large positive impact.
A moderate number of
full-scale and
demonstration projects.

Moderate.
Depends on existing
soil conditions and
quantities of plant
nutrients normally
applied.

A moderate number of
full-scale and
demonstration projects.

Moderate.
at = metric tonnes, T = English tons
b Estimates of useful site life from EPA's Technical Support Document for Land Application of Sewage Sludge (U.S. EPA, 1992). Site life may
 be longer if sludge is not applied every year.
A major advantage of agricultural land application is that
usually the treatment works does not have to purchase
land. The land utilized  for sewage sludge application is
kept in production, its value for future uses is  not im-
paired, and it remains on the tax rolls. Finally, agricul-
tural land application usually takes place in a relatively
rural setting where the application of sewage sludge is
similar to  conventional  farming operations,  such  as
spreading animal manure, and is not likely to become a
public  nuisance if properly managed.

2.2.3   Limitations of Agricultural Land
       Application

Sewage  sludge application rates for agricultural land
application (dry unit weight of sludge applied per unit of
land area) are  usually relatively low. Thus, large land
areas  may be needed, requiring  the cooperation of
many individual land owners. In addition, sewage sludge
transport, as well as application  scheduling that is com-
patible with agricultural planting, harvesting, and possi-
ble adverse climatic  conditions, will  require  careful
management. If  the farms accepting  sewage  sludge
are numerous and widespread, an expensive and com-
plicated  sewage sludge  distribution system may  be
required.

2.3   Application to Forest Lands

2.3.1   Purpose and Definition

Except for certain areas  in the Great Plains and the
southwest, forested lands are abundant and well distrib-
uted throughout most of the United States. Many treat-
ment works are located in close proximity to forests; in
fact, it is estimated that close to one-third  of the land
within  standard metropolitan areas is forested. Further-
more,  approximately two-thirds  of all forest land in the
United States  is  commercial  timberland (Smith and
                                  Evans, 1977). Thus, while currently 3 percent of sewage
                                  sludge that is land applied is applied to forest sites, the
                                  application of sewage sludge  to forest soils has the
                                  potential to be a major sewage sludge use practice.

                                  Sewage sludge has been land applied at forest sites in
                                  more than ten states, at least on an experimental, field-
                                  scale  level.  The  most extensive experience with this
                                  practice is in the Pacific Northwest. Seattle, Washington,
                                  and a number of smaller towns apply sewage sludge to
                                  forests on a relatively large scale.

                                  Three  categories of forest land may be  available for
                                  sewage sludge application:

                                  • Recently cleared land  prior to planting

                                  • Newly established plantations (about 3  to 10 years old)

                                  • Established forests

                                  The availability of sites and application considerations
                                  for each type of site listed above (as discussed in Chap-
                                  ter 8) will determine which type of site or combination of
                                  sites is best for a forest land application program.

                                  2.3.2  Advantages of Forest Land Application

                                  Sewage sludge contains nutrients and essential micro-
                                  nutrients often  lacking  in forest soils.  Demonstration
                                  projects have  shown greatly  accelerated  tree growth
                                  resulting from sewage sludge application to both newly
                                  established plantations and established forests. In addi-
                                  tion, sewage sludge contains organic matter that can
                                  improve the condition of forest soils by increasing the
                                  permeability of fine-textured clay soil, or by increasing
                                  the water-holding capacity of sandy soils.

                                  Treatment works  located near forest lands may benefit
                                  because forest land application may be  less expensive
                                  than other methods of sewage sludge use or disposal.
                                  The general public may benefit from cost savings  real-

-------
ized by the treatment works and commercial tree grow-
ers using the sewage sludge, and the recycling of nutri-
ents in sewage sludge is attractive to environmentally
concerned citizens. Because forests are perennial, the
scheduling of sewage sludge applications is not as com-
plex as  it may be for agricultural land application pro-
grams, for which planting and harvesting cycles must be
considered. A final advantage of forest land application
is  that the treatment works may not have to pay for
acquiring land. Sewage sludge application to forest soils
is generally performed either annually or at 3- to 5-year
intervals.

2.3.3  Limitations of Forest Land Application

Because sewage  sludge application to forest lands is
not as widely practiced as agricultural application, guid-
ance on this  practice is more limited. Chapters provides
information on  land application at forest sites. The Natu-
ral  Resource Conservation Service (formerly the Soil
Conservation Service) and County Land-Grant Univer-
sity Extension  agents may  be able to assist with pro-
gram design and implementation.

It may be difficult to control public access to sewage
sludge-amended forest lands. The public is accustomed
to free access to forested  areas for recreational pur-
poses and may tend to ignore posted signs, fences, etc.
Public access  restrictions required in Part 503 are dis-
cussed in Chapter 3. Forest lands generally are consid-
ered to have low potential for public exposure regarding
risks associated with the land application of sewage
sludge.

Access into  some forest lands may be difficult for con-
ventional sewage sludge application equipment. Terrain
may be uneven and obstructed. Access roads may have
to be built,  or specialized sewage sludge application
equipment used or developed.

2.4  Land Application at Reclamation
      Sites

2.4.1  Purpose and Definition

The surface mining of coal, exploration for minerals,
generation of mine spoils from underground mines, and
tailings from mining operations have created over 1.5
million ha (3.7 million ac) of drastically disturbed land.
The properties of these  drastically disturbed and mar-
ginal  lands vary considerably from  site to site. Their
inability  to support vegetation  is the result of several
factors:

• Lack  of nutrients.  The soils have low  N, P, K,  or
  micronutrient levels.

• Physical properties. Stony or sandy  materials  have
  poor water-holding capacity and low cation exchange
  capacity  (CEC). Clayey soils have  poor infiltration,
  permeability, and drainage.

• Chemical properties. The  pH of mine soils, tailings,
  and some drastically disturbed soils  range from very
  acidic to  alkaline. Potentially phytotoxic levels of Cu,
  Zn, Fe, and salts may be present.

• Organic matter. Little, if any, organic matter is present.

• Biological properties. Soil biological activity is gener-
  ally reduced.

• Topography. Many of these lands are characterized
  by steep  slopes that are subject to excessive erosion.

Historically, reclamation of these lands  is accomplished
by grading  the surface to slopes that minimize erosion
and  facilitate revegetation.  In  some cases, topsoil  is
added. Soil amendments such as lime and fertilizer also
are added, and grass, legumes, or trees are  planted.
Although these methods are sometimes successful, nu-
merous failures have  occurred, primarily because of the
very poor physical, chemical, or biological properties  of
these disturbed lands.

Sewage sludge can  be used to return barren  land  to
productivity or to provide the vegetative  cover necessary
for controlling soil erosion. A relatively  large amount  of
sewage sludge must be  applied to  a  land area (7 to
450 t DW/ha) to provide  sufficient organic matter and
nutrients capable of supporting  vegetation until a self-
sustaining ecosystem can be established. Because  of
these typically large,  one-time applications of sewage
sludge at  reclamation sites, the Part  503 rule allows
sewage sludge application at reclamation sites to ex-
ceed agronomic rates for N if approved  by the permitting
authority, who may require  surface water or ground-
water monitoring as a condition for sewage sludge ap-
plication, if deemed necessary.

Pilot and full-scale demonstration projects have been
undertaken in at least 20 states to study the application
of sewage  sludge to  reclaimed lands. The results sug-
gest that sewage sludge can  be used  effectively  to
reclaim disturbed  sites when the application of sewage
sludge is managed properly. The following factors must
be considered: the degree to which the sewage sludge
is stabilized, sewage sludge application rates, the de-
gree of land  slope, and siting issues  (e.g., quality  of
aquifer, depth to ground water).

Because sewage sludge typically is  applied only once
to land reclamation sites, an ongoing program of sew-
age sludge application to disturbed lands requires that
a planned  sequence of additional sites be available for
the life of the program. This objective may be achieved
through arrangements with  land  owners  and mining
firms active in the area or through planned sequential
rehabilitation  of existing disturbed land areas. Once a
reclamation site  is reclaimed, sewage sludge  can be

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applied to the site in compliance with the requirements
for the type of site it may become (e.g., agricultural or
forest land, or a public contact site). For example, re-
claimed  areas may be  used for crop production using
agronomic rates of sewage sludge application.

2.4.2  Advantages of Land Application at
       Reclamation Sites

Land application may be extremely attractive in areas
where disturbed and marginal lands exist because of the
benefit to the treatment works in using  or disposing its
sewage  sludge and to the environment through recla-
mation of unsightly, largely useless land areas.

Sewage sludge has several characteristics that makes
it suitable for reclaiming and improving  disturbed lands
and marginal soils. One of the most important is the
sewage  sludge organic matter which (1) improves soil
physical properties by improving granulation, reducing
plasticity and cohesion, and increasing water-holding
capacity; (2) increases the soil cation exchange capac-
ity; (3) supplies plant nutrients;  (4) increases and buffers
soil pH;  and (5) enhances the rejuvenation of microor-
ganism populations and activity.

The natural buffering capacity  and pH of most  sewage
sludge will  improve the acidic or moderately  alkaline
conditions found in many mine soils. Immobilization of
heavy metals is pH-dependent, so sewage sludge ap-
plication reduces  the potential for acidic, metal-laden
runoff and leachates.  Sewage sludge is also desirable
because the nutrients contained in it may substantially
reduce commercial fertilizer needs. Furthermore, sew-
age sludge helps to increase the number and activity of
soil microorganisms.

The amount of sewage sludge  applied in a single appli-
cation can often be greater for  land reclamation  than for
agricultural land application, provided that the quantities
applied do not pose a serious risk of future plant phyto-
toxicity or unacceptable  nitrate leaching into a  potable
ground water aquifer, and if regulatory agency approval
is granted. In some cases, serious degradation of sur-
face water and ground  water may already exist at the
proposed site, and a relatively heavy  sewage sludge
addition  with subsequent revegetation  can be  justified
as improving an already bad situation.

The treatment works may not have to purchase  land for
reclamation projects. In addition, disturbed or marginal
lands  are usually located in  rural, relatively  remote
areas.

2.4.3  Limitations  of Land Application at
       Reclamation Sites

Plant  species for revegetation at reclamation sites
should be carefully selected for their suitability to local
soil and  climate conditions. If crops intended for animal
feed or human  consumption are planted, the require-
ments for agricultural land application of sewage sludge
have to be met.

Reclamation sites,  especially old abandoned mining
sites, often have irregular, excessively eroded terrain.
Extensive grading and other site  preparation steps may
be necessary to prepare the site for sewage sludge
application. Similarly, disturbed lands often have irregu-
lar patterns of soil characteristics. This may cause diffi-
culties  in sewage sludge application, revegetation, and
future site monitoring.

2.5   Land Application at  Public Contact
      Sites, Lawns, and Home Gardens

2.5.1   Purpose and Definition

Approximately 9 percent of sewage sludge that is land
applied annually is used as a soil conditioner or fertilizer
on land  having a high potential for public contact. These
public  contact  sites include public parks, ball fields,
cemeteries, plant nurseries, highway median strips, golf
courses, and airports, among others. Another 12 per-
cent of land applied sewage sludge is sold or given away
in a bag or other container, most likely for application to
public contact sites,  lawns, and home gardens. Usually,
sewage sludge  that is sold or given away in a bag or
other container is composted, or heat dried (and some-
times formed into pellets). Composted sewage sludge is
dry, practically odorless, and easy to distribute and han-
dle. Bagged or otherwise containerized sewage sludge
that is sold  or given  away often is used as a substitute
for topsoil and  peat  on lawns, golf courses, parks, and
in ornamental and vegetable gardens. Yield improve-
ments have been valued at $35 to $50 per dry ton over
other potting media (U.S. EPA, 1993).

There  have been two basic approaches to sewage
sludge  use in  parks and recreational areas: (1)  land
reclamation followed by park establishment, and (2) use
of sewage sludge as a substitute for conventional fertil-
izers in the maintenance of established parkland vege-
tation.  Sewage sludge can supply a portion of the
nutrients required to maintain lawns, flower gardens,
shrubs  and trees, golf courses, recreational areas, etc.

2.5.2  Advantages of Land Application at
        Public Contact Sites, Lawns, and Home
        Gardens

Programs  designed to promote  sewage  sludge  land
application  to public contact sites, lawns, and home
gardens are particularly  advantageous for  treatment
works having limited opportunities for other types of land
application  (e.g., at  forest sites, agricultural  land, and
reclamation sites).

-------
In some areas of the country, a high demand exists for
bagged sewage sludge applied to public contact sites,
lawns, and home gardens. This is, in part, due to the fact
that sewage sludge often is sold at lower cost than many
commercial fertilizers, or is given away free. In addition,
although the nutrient content of many sewage sludges
is lower than that of commercial fertilizers,  sewage
sludge contains organic matter that can release nutri-
ents  more  slowly, minimizing potential  "burning" of
plants (Lue-Hing et al., 1992).

2.5.3   Limitations of Land Application at
        Public Contact Sites, Lawns, and Home
        Gardens

Many of the strictest requirements of the Part 503 rule,
in particular the pollutant limits for metals and the patho-
gen requirements,  must be met for sewage sludge ap-
plied to lawns, home gardens, and  public contact sites.
This is because  of the high potential for human contact
with the sewage sludge at these sites and because it is
not possible to impose site restrictions when  sewage
sludge is sold or given away in a bag or other container
for application to the land. While meeting the pollutant
limits and pathogen requirements will not be difficult for
many sewage sludge preparers, some treatment works
have  reported  problems in meeting certain  of these
requirements, and corrective measures would  involve
increased operational costs.

In general, the costs of a program that markets sewage
sludge for use on  lawns,  home  gardens, and public
contact sites may be greater than the costs of direct land
application.  Major  costs  include those  for  sewage
sludge dewatering,  processes to  achieve adequate
pathogen and vector attraction reduction, market devel-
opment, and transportation.


2.6    References

Lue-Hing, C., D.R.  Zenz, and R. Kuchenrither, eds. 1992. Municipal
  sewage sludge management: Processing, utilization,  and dis-
  posal. In: Water quality management library, Vol. 4. Lancaster, PA:
  Technomic Publishing Company, Inc.

Smith, W,  and J. Evans. 1977. Special opportunities and problems
  in using forest soils for organic waste application. In: Elliott, L.F.,
  and J.F. Stevenson, eds.  Soils for management of organic wastes
  and wastewaters. Soil Science Society of America, Madison, Wl.

U.S. EPA. 1993. Standards for the use or disposal of sewage sludge.
  Fed. Reg. 58(32):9259.
                                                    10

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                                             Chapter 3
     Overview of the Part 503 Regulatory Requirements for Land Application of
                                         Sewage Sludge
3.1   General
The federal Part 503 rule (40 CFR Part 503) establishes
requirements for land applying sewage sludge (includ-
ing  domestic septage)  to ensure protection of  public
health  and the environment when  sewage sludge is
used for its soil conditioning or fertilizing properties.
Promulgated in 1993, Part 503 covers sewage sludge
sold or given away in bulk, bags, or other containers for
application to agricultural land (e.g., cropland, pastures,
and rangelands), forests, reclamation sites (e.g., mine
spoils, construction sites, and gravel pits), public contact
sites (e.g., parks, plant nurseries), and lawns and home
gardens. The rule's land application requirements also
pertain to material derived from sewage sludge. Such
materials include sewage sludge that has undergone a
change in quality through  treatment (e.g., composting,
drying) or mixing with other materials (e.g., wood chips)
after it  leaves the treatment works where it was gener-
ated. Part 503  also covers surface disposal and incin-
eration of sewage sludge,  which are beyond the  scope
of this manual.

This chapter highlights key aspects of the Part 503 rule
as they pertain to land application of sewage sludge,
including general requirements, pollutant limits, man-
agement practices, pathogen and vector attraction re-
duction, frequency  of  monitoring, recordkeeping,  and
reporting,  as shown in Chapter 1,  Figure 1-1.  For a
discussion of Part 503 requirements for the land appli-
cation of domestic septage, see Chapter 11. More de-
tailed discussions of the rule can be found in other EPA
documents (U.S. EPA,  1992a; 1992b; 1994).

For most types of sewage sludge other than those spe-
cifically excluded (see Table 3-1), the requirements in 40
CFR Part 503 supersede those in 40 CFR Part 257—the
previous rule that governed the use or disposal of sew-
age sludge from 1979  to 1993. Part 503 establishes
minimum standards; when  necessary to protect  public
health  and the environment, the permitting authority
may impose requirements that are more stringent than,
or in addition to, those  stipulated in the Part 503  rule.
The  rule leaves  to the discretion  of individual  states
whether to administer a more restrictive sewage sludge
use or disposal program than is required by the federal
regulation. A state  program may even define sewage
sludge differently than the federal regulation (see Table
3-2). Also, while state officials are encouraged to submit
their sewage sludge programs for review and approval
by EPA, they are not required to do so. A disadvantage
of an unapproved state program for the regulated com-
munity is the added  complexity of complying with all
applicable federal and state requirements, including the
most restrictive requirements of both the  state program
and  the federal rule.  Both state  and federal  operating
permits also might be required in a state with a sewage
sludge management  program that has  not  been  ap-
proved by EPA.

For the most part, the requirements of the Part 503  rule
are implemented  through permits issued by EPA or by a
state that administers an EPA-approved sewage sludge
management program (see Table 3-3). But the Part 503
rule  is "self-implementing," meaning that persons who
generate, prepare,  or land apply sewage sludge must
comply with the  rule even if they  are not specifically
required to obtain a permit.

To ensure compliance with the rule, regulatory officials
have the authority to inspect operations, review records,
sample applied sewage sludge, and generally respond
to complaints concerning public health  or public  nui-
sances. EPA also is  prepared to pursue enforcement
actions when necessary to address violations, whether
willful or the result  of negligence. In the absence of a
government enforcement  action, private citizens have
standing to  pursue civil remedies against a violator un-
der the Clean Water Act.

3.2   Pollutant Limits

Subpart B of the  Part 503 rule prohibits the land appli-
cation of sewage sludge  that exceeds pollutant limits
termed ceiling concentrations in the rule  for 10 metals,
and  places  restrictions on the land application of sew-
age sludge that exceeds additional pollutant limits speci-
fied  in the  rule  (pollutant concentrations, cumulative
                                                 11

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Table 3-1.  Types of Sludge, Septage, and Other Wastewater
           Solids Excluded From Coverage Under Part 503
                                                              Table 3-2.  Definitions of Terms Under the Part 503 Rule
Sludge Type
Applicable Federal
Requirements
Sewage sludge that is hazardous
in accordance with 40 CFR Part
261

Sewage sludge with a PCB
concentration equal to or greater
than 50 mg/kg total solids (dry
weight  basis)

Grit (e.g., small pebbles and
sand) and screenings (e.g., large
materials such as rags) generated
during preliminary treatment of
sewage sludge

Commercial septage  (e.g., grease
from a  grease trap at a
restaurant) and industrial septage
(e.g., liquid or solid material
removed from a septic tank that
receives industrial wastewater)
and mixtures of domestic septage
and commerical or industrial
septage

Industrial sludge and sewage
sludge  generated  at an industrial
facility during the treatment of
industrial wastewater with  or
without combined  domestic
sewage

Incinerator ash generated  during
the  firing of sewage sludge in a
sewage sludge incinerator
Sewage sludge co-fired in an
incinerator with other wastes
(other than an auxiliary fuel)

Drinking water sludge generated
during the treatment of either
surface water or ground water
used for drinking water


Treatment of sewage sludge prior
to final use or disposal (e.g.,
processes such as thickening,
dewatering, storage, heat drying)
Storage of sewage sludge as
defined in Part 503
                                   40 CFR Parts 261-268
40 CFR Part 761
40 CFR Part 257 (if
land applied)
40 CFR Part 258 (if
placed  in a municipal
solid waste landfill)

40 CFR Part 257 (if
land applied)
40 CFR Part 258 (if
placed  in a municipal
solid waste landfill)
40 CFR Part 257 (if
land applied)
40 CFR Part 258 (if
placed  in a municipal
solid waste landfill)


40 CFR Part 257 (if
land applied)
40 CFR Part 258 (if
placed  in a municipal
solid waste landfill) or
40 CFR Parts 261-268
(if hazardous)

40 CFR Parts 60, 61
40 CFR Part 257 (if
land applied)
40 CFR Part 258 (if
placed  in a municipal
solid waste landfill)

None (except for
operational parameters
used to meet Part 503
pathogen and vector
attraction reduction
requirements)

None
                                                              Bulk Sewage Sludge
                                                              Domestic Septage
Domestic Sewage



Preparer
Scum, Grit, and
Screenings
Sewage Sludge
Treatment Works
Sewage sludge that is not sold or given
away in a bag or other container for
application to land.

A liquid or solid material removed from a
septic tank, cesspool, portable toilet, Type
III marine sanitation device, or similar
system that receives only domestic
sewage. Domestic septage does not
include grease-trap pumpings or
commercial/industrial wastes.

Waste and wastewater from humans or
household operations that is discharged
to or otherwise enters  a treatment works.

The person who generates sewage
sludge  during the  treatment of domesitc
sewage in a treatment works, or the
person  who derives a material from
sewage sludge.

Scum consists of floatable materials in
wastewater and is regulated by  Part 503
if it is subject to one of the Part 503 use
or disposal practices because it is, by
definition, sewage sludge. Grit, which is
regulated under 40 CFR Part 257 when
applied to the land, consists of heavy,
coarse, inert solids (e.g., sand, silt,
gravel,  ashes, corn grains, seed, coffee
ground, and bottle caps) associated with
raw wastewater. Screenings, which also
are  regulated under Part 257 when
applied to the land, consist of such solids
as rags, sticks, and trash found  in the
raw wastewater.

A solid, semi-solid, or liquid residue
generated during the treatment of
domestic sewage in a treatment
works.  Sewage sludge includes scum
or solids removed in  primary,
secondary, or advanced  wastewater
treatment processes  and  any  material
derived from sewage sludge (e.g., a
blended sewage  sludge/fertilizer
product), but does not include grit and
screening or ash generated by the
firing of sludge in an incinerator. Part
503 considers domestic septage as
sewage sludge and sets separate
requirements for domestic septage
applied to agricultural land, forests, or
reclamation sites.

A federally, publicly, or privately  owned
device  or system used to treat (including
recycle and reclaim) either domestic
sewage or a combination of domestic
sewage and industrial waste of a liquid
nature.
pollutant loading  rates [CPLRs], or annual pollutant
loading rates [APLRs]). For one of the regulated met-
als, molybdenum, only  ceiling  concentrations apply
while  EPA reconsiders the CPLRS, pollutant concen-
tration limits, and  APLRs established by the rule. The
different types  of  pollutant limits included in Part 503
are discussed below and are listed in Table 3-4.
                           3.2.1   Ceiling Concentration Limits

                           All  sewage sludge applied to  land  must meet Part 503
                           ceiling concentration limits for the 10 regulated pollutants.
                           Ceiling concentration  limits are the  maximum allowable
                           concentration  of a pollutant in  sewage sludge to be land
                           applied.  If the  ceiling concentration limit for any one of the
                           regulated pollutants is exceeded, the sewage sludge can-
                           not be land applied. The ceiling concentration limits were
                                                           12

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Table 3-3.  Who Must Apply for a Permit?
Treatment Works Treating Domestic Sewage (TWTDS)
Required to Apply for a Permit
• All generators of sewage sludge that is regulated by Part 503
  (including all POTWs)

• Industrial facilities that separately treat domestic sewage and
  generate sewage sludge that is regulated by Part 503

• All surface disposal site owner/operators
• All sewage sludge incinerator owner/operators

• Any other person designated by the permitting authority as a
  TWTDS

TWTDS and Other Persons Not Automatically Required To
Apply for a Permit3
• Any person (e.g., individual, corporation, or government entity)
  who changes the quality of sewage sludge regulated by Part 503
  (e.g., sewage sludge blenders or processers)
• Sewage sludge land appliers, haulers, persons who store, or
  transporters who do not generate or do  not change the quality of
  the sludge

• Land owners  of property on which sewage sludge is applied
• Domestic septage pumpers/haulers/treaters/appliers

• Sewage sludge packagers/baggers (who do not change the
  quality of the  sewage sludge)

3 EPA  may  request  permit applications from these persons when
  necessary to  protect public health and  the environment from rea-
  sonably anticipated effects of pollutants that may be present in
  sewage sludge.
b If all the sewage sludge received by a sludge blender or composter
  is exceptional quality (EQ) sludge, then no permit will  be required
  for the person who receives or processes the EQ sludge.
                                         developed  to  prevent the land  application of sewage
                                         sludge containing high concentrations of pollutants.

                                         3.2.2  Pollutant Concentration Limits

                                         Pollutant concentration limits are the most stringent pol-
                                         lutant limits included in  Part 503 for land  application.
                                         These limits help ensure that the quality of land-applied
                                         sewage sludge remains at least as  high as the quality
                                         of sewage sludge at the  time the  Part 503 rule was
                                         developed. Sewage sludge  meeting pollutant concen-
                                         tration  limits, as well as certain  pathogen and vector
                                         attraction  reduction  requirements (see Section 3.7.1),
                                         generally is subject to fewer Part 503 requirements than
                                         sewage sludge  meeting cumulative pollutant loading
                                         rates (CPLRs) (discussed  below).

                                         3.2.3  Cumulative Pollutant Loading Rates
                                                 (CPLRs)

                                         A cumulative pollutant loading  rate (CPLR) is the  maxi-
                                         mum amount of a pollutant that can be applied to  a site
                                         by all bulk sewage sludge applications made after July
                                         20, 1993. CPLRs pertain only to land application of bulk
                                         sewage sludge, as defined in Part 503. When the  maxi-
                                         mum CPLR is reached at the application site for any one
                                         of the  10 metals  regulated  by  the  Part 503 rule, no
                                         additional sewage sludge subject to  the CPLRs can be
                                         applied to the site. If a CPLR is  reached at a site, only
                                         sewage sludge that meets the pollutant concentration
                                         limits could be applied to that site.
Table 3-4.  Part 503 Land Application Pollutant Limits for Sewage Sludge
Pollutant
Ceiling Concentration
Limits (milligrams per
    kilogram)a'b
Pollutant Concentration
 Limits (milligrams per
     kilogram)3'0
 Cumulative Pollutant
 Loading Rate Limits
(kilograms per hectare)
  Annual Pollutant
 Loading Rate Limits
(kilograms per hectare
 per 365-day period)
Arsenic
Cadmium
Chromiumd
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
Applies to:
From Part 503
75
85
3,000
4,300
840
57
75
420
100
7,500
All sewage sludge that
is land applied
Table 1, Section 503.13
41
39
1,200
1,500
300
17
d
420
36d
2,800
Bulk sewage sludge and
bagged sewage sludge8
Table 3, Section 503.13
41
39
3,000
1,500
300
17
	 d
420
100
2,800
Bulk sewage sludge
Table 2, Section 503.13
2.0
1.9
150
75
15
0.85
	 d
21
5.0
140
Bagged sewage sludge8
Table 4, Section 503.13
 Dry-weight basis.
b All sewage sludge samples must meet the ceiling concentrations, at a minimum, to be eligible for land application (instantaneous values).
c Monthly average.
d EPA is re-examining these limits.
8 Bagged sewage sludge is sold or given away in a bag or other container for application to the land.
                                                       13

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3.2.4   Annual Pollutant Loading Rates
        (APLRs)
3.3   Management Practices
The annual pollutant loading rate (APLR) is the maxi-
mum amount of a pollutant that can be applied to a site
within a 12-month period from sewage sludge that is
sold  or given away in a  bag or  other container for
application to land.1 To meet the APLRs, the pollutant
concentration in sewage sludge,  multiplied by the "an-
nual whole sludge application  rate,"  as determined in
Appendix A of the Part 503 rule, must not cause any of
the APLRs to be exceeded. APLRs rather then CPLRs
are used for sewage sludge sold or given away in a bag
or other container for application  to land because con-
trolling cumulative applications of these types of sewage
sludge would not be feasible.

APLRs are based on  a 20-year site life,  which EPA
considers  a  conservative  estimate  because  sewage
sludge sold or given away in small quantities will most
likely be  applied  to lawns, home gardens,  or public
contact sites. Sewage sludge is not likely to be applied
to such types of land for longer than  20 years;  indeed,
20  consecutive years  of application is unlikely  (U.S.
EPA, 1992a).
3.2.5  Why Organic Pollutants Were Not
        Included in Part 503
The Part 503 regulation does not establish pollutant
limits for any organic pollutants because EPA deter-
mined that none of the organics considered for regu-
lation2  pose  a public  health  or environmental  risk
from land application of sewage  sludge (U.S. EPA,
1992a). EPA used the following criteria to make this
determination:

• The pollutant is banned or  restricted  in the United
  States  or is no  longer manufactured  in the United
  States; or

• The pollutant is not present in sewage  sludge at sig-
  nificant frequencies of detection,  based on data gath-
  ered from the 1990 NSSS; or

• The limit for a pollutant from  EPAs exposure assess-
  ment is not expected  to  be exceeded in sewage
  sludge  that is used or disposed,  based on data from
  the NSSS.
1 "Other containers" are defined in Part 503 as open or closed recep-
 tacles, such as buckets, boxes,  cartons, or vehicles, with a load
 capacity of 1 metric ton or less.
2 Aldrin/dieldrin, benzene, benzo(a)pyrene, bis(2ethylhexyl)phthalate,
 chlordane,  DDT (and its derivatives ODD and DDE), dimethyl ni-
 trosamine,  heptachlor, hexachlorobenzene, hexachlorobutadiene,
 lindane, PCBs, toxaphene, and trichloroethylene.
As  described in Table 3-5, the Part 503 rule specifies
management practices that must be followed when sew-
age sludge is land applied. Management practices re-
quired  for  bulk  sewage  sludge  meeting Part  503
pollutant  concentration limits or  cumulative pollutant
loading rates protect  water quality and  the survival of
threatened or endangered species. For example,  bulk
sewage sludge that meets these pollutant limits cannot
be  applied to sites that are flooded or frozen in such a
way that the sewage sludge might enter surface waters
or wetlands. Also,  any  direct or  indirect  action  that
diminishes the likelihood of a threatened or endan-
gered species' survival by modifying its critical habi-
tat  is prohibited. Other Part 503 management practices
are listed in Table 3-5.

Table 3-5.  Part 503 Land Application Management Practices

For Bulk Sewage Sludge3

Bulk sewage sludge cannot be applied to flooded, frozen, or
snow-covered agricultural land, forests, public contact sites, or
reclamation sites in such a way that the sewage sludge enters a
wetland or other waters of  the  United States (as defined in 40
CFR Part 122.2), except as provided in a permit issued pursuant
to Section 402 (NPDES permit) or Section 404 (Dredge and Fill
Permit) of the Clean Water Act, as amended.

Bulk sewage sludge cannot be applied to agricultural  land, forests,
or reclamation sites that are 10 meters or less from U.S. waters,
unless otherwise specified  by the permitting authority.

If applied to agricultural lands, forests, or public contact sites, bulk
sewage sludge must be applied at a rate that is equal to or less
than the agronomic rate for the site. Sewage sludge applied to
reclamation sites may exceed the agronomic rate if allowed by the
permitting authority.

Bulk sewage sludge must not harm or contribute to the harm of a
threatened or endangered species or result in the destruction or
adverse modification of the species' critical habitat when applied to
the land. Threatened or endangered species and  their critical
habitats are listed in Section 4 of the Endangered Species Act.
Critical habitat is defined as any place where a threatened or
endangered species lives and grows during any stage of its life
cycle. Any direct or indirect action (or the result of any direct or
indirect action) in a critical  habitat that diminishes the  likelihood of
survival and recovery of a listed species is considered destruction
or adverse modification of a critical  habitat.

For Sewage Sludge Sold  or Given Away in a Bag  or Other
Container for Application to the Land3

A label must be affixed to the bag or other container,  or an
information sheet must be  provided to the person who receives
this  type of sewage sludge in another container. At a  minimum, the
label or information sheet must contain the following information:

• the name and address of the person who prepared the sewage
 sludge for sale or give-away in a bag or other container;

• a statement that prohibits application of the sewage  sludge to the
 land except in accordance with the instructions on the label or
 information sheet;

• an AWSAR (see Table 3-18) for the sewage sludge that does not
 cause the APLR pollutant limits to be exceeded.

3 These management practices do not apply if the sewage sludge is
 of "exceptional quality," as defined in section 3.7.
                                                      14

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The preparer of sewage sludge that is sold or given
away in a bag or other container for application to land
must comply with the Part 503  management practice
that requires the preparer to provide application rate
information, as well as other pertinent data, to the land
applier of sewage sludge meeting annual pollutant load-
ing rates (as discussed in Table 3-5 and Section 3.7.4).

3.4  Operational Standards for
      Pathogens  and Vector Attraction
      Reduction

Subpart D of the Part 503 rule describes requirements
for land  application of sewage sludge (and  domestic
septage, as discussed in Chapter 11) that reduce the
potential forthe spread of disease, thus protecting public
health and the  environment. The Part 503 Subpart D
requirements cover two characteristics of sewage sludge:

• Pathogens. Part 503 requires the reduction of poten-
  tial disease-bearing microorganisms called patho-
  gens (such as bacteria and viruses) in sewage sludge.

•  Vector Attraction. Part 503 also requires that the po-
  tential  for sewage sludge to attract vectors (e.g.,  ro-
  dents,  birds,  insects)  that can transport pathogens
  away from the land application site be  reduced.

Compliance with the  Part 503 pathogen and vector at-
traction  reduction  requirements, summarized below,
must be demonstrated separately.

3.4.1  Pathogen Reduction Requirements

The Part 503 pathogen reduction requirements for sew-
age sludge are divided into two categories: Class A and
Class B,  as shown in Table 3-6. The implicit goal of the
Class A  requirements is to reduce  the  pathogens  in
sewage sludge  (including  Salmonella sp. bacteria, en-
teric viruses, and viable  helminth ova) to  below detect-
able levels. When this goal is achieved, Class A sewage
sludge can be land applied without  any pathogen-re-
lated  restrictions on the site (see  Section  3.7).

The implicit  goal of the Class  B requirements  is  to
ensure that pathogens have been reduced to levels that
are unlikely to pose  a threat to  public health and the
environment under specific use conditions. Site restric-
tions on the land application  of Class B sewage sludge
minimize the  potential for human  and animal  contact
with the sewage sludge until environmental factors have
reduced  pathogens to below detectable levels. In addi-
tion, to further reduce the likelihood  of human  contact
with pathogens, Class B sewage  sludge cannot be sold
or given away  in a  bag  or other container for land
application. Part 503 Class A and B pathogen reduction
requirements  are  summarized  below;  another  EPA
document (U.S. EPA, 1992b) provides a detailed discus-
sion of pathogen reduction requirements under Part 503.
Table 3-6.  Summary of Class A and Class B Pathogen
          Alternatives
CLASS A

In addition to meeting the
requirements in one of the six
alternatives listed below, fecal
coliform or Salmonella sp.
bacterial levels must meet
specific densities at the time
of sewage sludge use or
disposal, when prepared for
sale or give-away in a bag or
other container for application
to the land, or when prepared
to meet the requirements in
503.10(b),  (c), (e), or (f)

Alternative 1: Thermally
Treated Sewage Sludge

Use one of four
time-temperature regimes

Alternative 2: Sewage Sludge
Treated in a High pH-High
Temperature Process

Specifies pH, temperature,
and air-drying requirements

Alternative 3: For Sewage
Sludge Treated in  Other
Processes

Demonstrate that the process
can reduce enteric viruses
and viable helminth ova.
Maintain operating conditions
used in the demonstration

Alternative 4: Sewage
Sludge Treated in Unknown
Processes

Demonstration of the process
is unnecessary. Instead, test
for pathogens—Salmonella
sp. bacteria, enteric viruses,
and viable helminth ova—at
the time the sewage sludge is
used or disposed, or is
prepared for sale or
give-away  in a bag or other
container for application to
the land, or when prepared to
meet the requirements in
503.10(b),  (c), (e), or (f)


Alternative 5: Use of PFRP

Sewage sludge is treated in
one of the  processes to further
reduce pathogens (PFRP)

Alternative 6: Use of a
Process Equivalent to PFRP

Sewage sludge is treated in a
process equivalent to one of
the PFRPs, as determined by
the permitting authority

CLASS B

The requirements in one of
the three alternatives below
must be met in addition to
Class B site restrictions

Alternative 1: Monitoring of
Indicator Organisms

Test for fecal coliform density
as an indicator for all
pathogens at the time of
sewage sludge use or disposal

Alternative 2: Use of PSRP

Sewage sludge is treated in one
of the processes to significantly
reduce pathogens (PSRP)

Alternative 3: Use of
Processes Equivalent to
PSRP

Sewage sludge is treated in a
process equivalent to one of
the PSRPs, as determined by
the permitting authority

Note: Details of each
alternative  for meeting the
requirements for Class A and
Class B designations are
provided in Section 3.4.
3.4.1.1   Class A Pathogen Requirements

Sewage sludge that must meet the Class A  pathogen
requirements  includes  sewage sludge that is  sold or
given away in a bag or other container for application to
land and bulk sewage sludge that is applied  to a lawn
or home garden.  Part  503 Subpart  D establishes six
alternatives  for  demonstrating  that  sewage  sludge
meets Class A pathogen reduction requirements (Table
3-6). The rule requires that the density of fecal conforms
be less than 1,000 Most Probable Number (MPN) per
gram total solids  (dry  weight) or that Salmonella sp.
bacteria be less than  3  per 4 grams  total solids, as
discussed in Table 3-7.
                                                     15

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Table 3-7.  Pathogen Requirements for All Class A Alternatives    Table 3-8.
The following requirements must be met for all six Class A
pathogen alternatives. Either:
• the density of fecal coliform in the sewage sludge must be less
 than 1,000 most probable number (MPN) per gram total solids
 (dry-weight basis),
                       or
• the density of Salmonella sp. bacteria in the sewage sludge must
 be less than 3 MPN per 4 grams of total solids (dry-weight basis).
This requirement must be  met at one of the following times:
• when the sewage sludge is used or disposed;
• when the sewage sludge is prepared for sale or give-away in a
 bag or other container for land application; or
• when the sewage sludge or derived material is prepared to meet
 the Part 503 requirements in 503.10(b), (c), (e), or (f)
Pathogen reduction  must take place before or at the same time as
vector attraction reduction, except when the pH adjustment or
percent solids vector attraction reduction options are met, or if
vector attraction reduction  is accomplished through  injection or
incorporation.

Each of the six alternatives for meeting Class A patho-
gen reduction requirements includes monitoring require-
ments to ensure that  substantial regrowth  of pathogenic
bacteria does not occur afterthe sewage sludge meets the
pathogen  reduction requirements prior to use or disposal.

The timing of Class A pathogen reduction in  relation to
vector attraction  reduction  requirements  (see Section
3.4.2) is important when certain vector attraction reduc-
tion options are used. Part 503 requires that Class  A
pathogen reduction be  accomplished before or at the same
time as vector attraction reduction,  except when vector
attraction reduction is achieved by alkali addition or drying.

The following discussion summarizes the Part 503 Class
A pathogen  reduction  alternatives. For a more complete
discussion of these alternatives, see Environmental Regu-
lations and Technology: Control of Pathogens and Vector
Attraction in Sewage Sludge (U.S. EPA, 1992b).

Alternative 1: Thermally Treated Sewage Sludge

This alternative may be used when the pathogen reduc-
tion process relies on  specific time-temperature regimes
to reduce pathogens (Table 3-8). The approach involves
calculating the heating  time necessary at a particular
temperature to reduce a sewage sludge's pathogen con-
tent to  below detectable  levels. The need to conduct
time-consuming  and expensive tests for the presence of
specific pathogens can be avoided with this approach.

The microbiological density portion of the requirement
(i.e., the regrowth requirement) is designed  to ensure
that the microbiological  reductions expected as a result
of the time-temperature  regimes have  actually been
attained and that regrowth has not occurred.  Equations
for each of the four time-temperature regimes takes  into
          The Four Time-Temperature Regimes for Pathogen
          Reduction Under Class A, Alternative 1
Regime
A
B
C
D
Applies to:
Sewage sludge
with 7% solids or
higher (except
those covered by
Regime B)
Sewage sludge
with 7% solids or
higher in the
form of small
particles heated
by contact with
either warmed
gases or an
immiscible liquid
Sewage sludge
with less than
7% solids
Sewage sludge
with less than
7% solids
Requirement
Temperature of
sewage sludge
must be 50°C
or higher for
not less than
20 minutes
Temperature of
sewage sludge
must be 50°C
or higher for
not less than
1 5 seconds
Heated for
more than 15
seconds but
less than 30
minutes
Temperature of
sludge is 50°C
or higher with
at least 30
minutes contact
time
Time-Temperature
Relationship3
131,700,000
-| QO. 14007
(Equation 3 of
Section 503.32)
131,700,000
10o.i40or
131,700,000
-| QO. 14007
50,070,000
U 10 0.14007
(Equation 4 of
Section 503.32)
' D = time in days; T = temperature in degrees Celsius.
account the percent of solids in the sewage sludge and
the operating parameters of the treatment process.

Alternative 2: Sewage Sludge Treated in a High
pH-High Temperature Process

This alternative may be used when the pathogen reduc-
tion process relies on a particular high temperature-high
pH process that has been demonstrated to be effective
in  reducing pathogens to below detectable  levels. The
high pH (>12 for more than 72 hours) and high tempera-
ture (above 52°C [126°F] for at least 12 hours while pH
is >12) for prolonged periods allow a less stringent time-
temperature regime than the requirements under Alter-
native 1. After the 72-hour period  during which the pH
of the sewage sludge  is above  12, the sewage sludge
must be air dried to achieve a percent solids content of
greater than 50 percent. As when thermal processing  is
used, monitoring for regrowth of pathogenic bacteria (fecal
coliforms orsalmonellae) must be conducted (Table 3-7).

Alternative 3: Sewage Sludge Treated in Other
Processes

This alternative applies to sewage sludge treated by
processes  that do not meet the process conditions re-
quired by Alternatives 1 and 2. Alternative 3 relies on
comprehensive  monitoring of fecal coliform or Salmo-
nella sp. bacteria; enteric viruses; and viable helminth
                                                     16

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ova to demonstrate adequate  reduction of pathogens,
as specified in the Part 503 rule.

If no enteric viruses or viable helminth ova are present
before treatment (i.e., in the feed sewage sludge), the
sewage sludge is Class A with respect to pathogens until
the next monitoring episode.  Monitoring  is continued
until enteric viruses or viable helminth ova are detected
in the feed sewage sludge,  at which point the treated
sewage sludge  is analyzed  to see if these organisms
survived treatment. If enteric virus and viable helminth
ova densities are below detection limits, the sewage
sludge meets Class A requirements and will continue to
do so  as long  as  the treatment process is  operated
underthe same conditions that successfully reduced the
enteric virus and viable helminth ova densities. Monitoring
for fecal coliform and Salmonella sp.  bacteria,  however,
must continue to be performed as indicated in Table 3-7.

Alternative 4: Sewage Sludge Treated in Unknown
Processes

This alternative  is used primarily for  stored  sewage
sludge for which the history  is  unknown. It also can be
used  when the  process in  which sewage sludge is
treated  does not meet any of the  descriptions of a
Process to Further Reduce Pathogens (PFRP).  In this
alternative,  a representative sample of  the  sewage
sludge must meet the Part 503  requirements for Salmo-
nella sp. or fecal coliform bacteria (as  described in Table
3-7); enteric viruses; and viable helminth ova at the time
the sewage sludge  is used  or disposed,  prepared  for
sale or give-away in a bag or other container for appli-
cation to land, or prepared to meet "exceptional quality"
(EQ) land application requirements (as discussed later
in this chapter). The number of samples that have to be
collected and analyzed for pathogen densities is  based
on the amount  of sewage sludge that is  land applied
annually (see the requirements for frequency of moni-
toring in the land application  subpart of Part 503).

Alternative 5: Use of a PFRP

This alternative provides continuity with the 40 CFR Part
257 regulation (the predecessor to Part 503). For Alter-
native  5, sewage sludge qualifies as Class A if it has
been treated in  one of the processes to further reduce
pathogens (PFRPs) (Table 3-9) and meets the regrowth
requirement in Table 3-7. The treatment processes must
be operated  according to the  PFRP process descrip-
tions summarized in Table 3-9 at all times. The list of
processes in  Table 3-9 (which appears as Appendix B in
the Part 503 regulation) is  similar to the PFRP ap-
proaches listed in Part 257, with two  major differences:

• All  requirements concerning vector  attraction  have
  been removed.
Table 3-9.  Processes To Further Reduce Pathogens (PFRPs)
          Listed in the Part 503 Rule

1. Composting

Using either the within-vessel composting  method or the static
aerated pile composting method, the temperature of the sewage
sludge is maintained at 55°C (131°F) or higher for 3 days.

Using the windrow composting method, the temperature of the
sewage sludge is maintained at 55°C (131°F) or higher for 15
days or longer. During the period when the compost is maintained
at 55°C (131°F) or higher, there shall be a minimum of five
turnings of the windrow.

2. Heat Drying

Sewage sludge is dried by direct or indirect contact with hot gases
to reduce the moisture content of the sewage sludge to 10% or
lower. Either the temperature of the sewage sludge particles
exceeds 80°C (176°F) or the wet bulk temperature of the gas in
contact with the sewage sludge as the sewage sludge leaves the
dryer exceeds 80°C (176°F).

3. Heat Treatment

Liquid sewage sludge is heated to a temperature of 180°C (356°F)
or higher for 30 minutes.

4. Thermophilic Aerobic Digestion

Liquid sewage sludge is agitated with air or oxygen to maintain
aerobic conditions and the mean cell residence time (i.e., the
solids retention time) of the sewage  sludge is 10 days at 55°C
(131°F)to60°C (140°F).

5. Beta Ray Irradiation

Sewage sludge is irradiated with beta rays from an electron
accelerator at dosages of at least 1.0 megarad at room
temperature (ca. 20°C [68°F]).

6. Gamma Ray Irradiation

Sewage sludge is irradiated with gamma rays from certain
isotopes, such as Cobalt 60 and Cesium 137, at dosages of at
least 1.0 megarad at room temperature (ca. 20°C [68°F]).

7. Pasteurization

The temperature of the sewage sludge is  maintained at 70°C
(158°F) or higher for 30 minutes or longer.
• All  "add-on" processes  listed  in  Part  257 are now
  PFRPs because Part 503 contains separate require-
  ments for vector attraction reduction.

Under this alternative, treatment processes classified as
PFRPs under Part 257  can continue to be operated;
however, microbiological monitoring (i.e., for fecal coli-
form or Salmonella sp. bacteria) must now be performed
to ensure that pathogen density levels are below detec-
tion limits and that regrowth of Salmonella sp. bacteria
does  not occur between treatment and use or disposal
of the sewage sludge.

Alternative 6: Use of a Process Equivalent to a
PFRP

Under this alternative, sewage sludge is  considered to
be Class A sewage sludge if it is treated by any process
equivalent to a PFRP  and meets the regrowth require-
ment in Table 3-7. To be equivalent, a treatment process
                                                     17

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must be able to consistently reduce pathogens to levels
comparable to the reduction achieved by a listed PFRP.
Processes must be operated at all times at the parame-
ters described in the process description. The Part 503
rule gives the  permitting authority responsibility for de-
termining equivalency. To assist in  making such deter-
minations, the EPA's Pathogen Equivalency Committee
(PEC) serves  as a resource,  providing  recommenda-
tions on the equivalency of processes;  the PEC  also
provides guidance to the regulated  community. Equiva-
lency determinations can be made  on a site-specific or
national basis. Processes recommended in Part 257 as
equivalent (Table 3-10) should yield sewage sludge that
meets Class A pathogen reduction requirements, as
long as microbiological requirements are also met.
Table 3-10.  A Partial List of Processes Recommended as
           Equivalent to PFRP Under Part 2571
    Operator
           Process Description
Scarborough      Static pile aerated "composting" operation that
   Sanitary       uses fly ash from a paper company as a
   District        bulking agent. The process creates pile
   Scarborough   temperatures of 60°C to 70°C (140°F to
   Mgjne         158°F) within 24 hours and maintains these
                temperatures for up to 14 days. The material
                is stockpiled after 7 to 14 days of "composting"
                and then marketed.

Mount Holly       Zimpro 50-gpm low-pressure wet air oxidation
   Sewage       process.  The process involves heating raw
   Authority       primary sewage sludge to 177°C to 204°C
   Mount Holly    (350°F to 400°F) in a reaction vessel under
   New Jersey
pressures of 250 to 400 psig for 15 to 30
minutes.  Small volumes of air are introduced
into the process to oxidize the organic solids.
Miami-Dade       Anaerobic digestion followed by solar drying.
   Water and     Sewage sludge is processed by anaerobic
   Sewer        digestion in two well-mixed digesters operating
   Authority       'n ser'es 'n a temperature range of 35°C to
   Miami, Florida  f°C , Total residence time is 30
                days. The sewage sludge is then centrifuged
                to produce a cake  of between 15% to 25%
                solids. The sewage sludge cake is dried for 30
                days on a paved bed at a depth of no more
                than 46 cm (18 inches). Within 8 days of the
                start of drying, the  sewage sludge is turned
                over at least once  every other day until the
                sewage sludge reaches a solids content of
                greater than 70%.

1These processes were all recommended for site-specific equivalency.
3.4.1.2   Class B Pathogen Requirements

Bulk sewage sludge that is applied to agricultural land,
forests, public contact sites, or reclamation sites must
meet the Class B pathogen  requirements if it does not
meet Class A pathogen requirements. Part 503 Subpart
D  establishes three alternatives for demonstrating that
sewage sludge meets Class B pathogen requirements
(Table 3-6). The  rule's  implicit  objective for all  three
approaches is to  ensure that  pathogenic bacteria and
enteric viruses are reduced in density, as demonstrated
by a fecal coliform density in the treated sewage sludge
Table 3-11.  Restrictions for the Harvesting of Crops and Turf,
           Grazing of Animals, and Public Access on Sites
           Where Class B Sewage Sludge is Land Applied

Restrictions for the harvesting of crops and turf:
   1. Food crops with harvested parts that touch the sewage
   sludge/soil mixture and are totally above ground shall not be
   harvested for 14 months after application of sewage sludge.
   2. Food crops with harvested parts below the land surface
   where sewage sludge remains on the land surface for 4
   months or longer prior to incorporation into the  soil shall not
   be harvested for 20 months after sewage sludge application.
   3. Food crops with harvested parts below the land surface
   where sewage sludge remains on the land surface for less
   than 4 months prior to incorporation shall not be harvested for
   38 months after sewage sludge application.
   4. Food crops, feed crops, and fiber crops, whose edible parts
   do not touch the surface of the soil, shall not be harvested for
   30 days after sewage sludge application.
   5. Turf grown on land where sewage sludge  is  applied shall
   not  be harvested for 1 year after application  of  the sewage
   sludge when the harvested turf is placed on  either land with a
   high potential for public exposure or a  lawn,  unless otherwise
   specified by the permitting authority.

Restriction for the grazing of animals:
   1. Animals shall not be grazed on land for 30 days after
   application of sewage sludge to the land.

Restrictions for public contact:
   1. Access to land with a high potential for public exposure,
   such as a park or ballfield, is restricted for 1  year after
   sewage sludge application. Examples of restricted access
   include posting with no trespassing signs, or fencing.
   2. Access to land with a low potential for public exposure
   (e.g., private farmland) is restricted for 30 days after sewage
   sludge application. An example of restricted access is
   remoteness.
                                          of 2  million Most Probable  Number  (MPN) or colony-
                                          forming units (CPU) per gram total solids sewage sludge
                                          (dry-weight basis). Viable helminth ova are not neces-
                                          sarily reduced in Class B sewage sludge.

                                          Unlike  Class  A  sewage sludge, which  is  essentially
                                          pathogen-free, Class B  sewage sludge contains some
                                          pathogens. Therefore, site restrictions  (Table 3-11) ap-
                                          ply for a certain period when Class B sewage sludge is
                                          land  applied to allow environmental factors to further
                                          reduce pathogens to below detectable  levels. Addition-
                                          ally, Class  B sewage sludge must meet a vector attrac-
                                          tion  requirement  (see  Section  3.4.2).  The  three
                                          alternatives for meeting Part 503 Class B pathogen
                                          reduction  requirements  are summarized below; more
                                          detailed information on  Class B  pathogen requirements
                                          can be found in another EPAdocument (U.S. EPA, 1992b).

                                          Alternative 1: Monitoring of Fecal Coliform

                                          This  alternative requires that seven samples of treated
                                          sewage sludge  be collected at the time of use or dis-
                                          posal, and that the geometric mean fecal coliform den-
                                          sity of these sample be  less that 2 million CPU or MPN
                                          per gram  of sewage sludge solids (dry-weight basis).
                                          Analysis  of multiple  samples is  required during each
                                                       18

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monitoring period because the methods used to deter-
mine fecal coliform density (i.e.,  membrane filter meth-
ods and the MPN dilution method) have poor precision
and because sewage sludge quality tends to vary. Use
of at least seven samples  is  expected to reduce the
standard error to a reasonable value.

Alternative 2: Use of a PSRP

Under this alternative, which  provides continuity with
Part 257, sewage sludge is considered to be Class B if
it  is treated  in  one  of the processes to  significantly
reduce pathogens (PSRPs) (Table 3-12). The  list of
processes (which appears as Appendix B in the Part 503
regulation) is similar to the PSRP approaches listed in Part
257, except that all conditions related to reduction of vector
attraction  have  been  removed. Unlike  the  comparable
Class A requirement, this alternative does not require mi-
crobiological monitoring because public access to the site
is  restricted, allowing time for environmental conditions to
reduce pathogens to below detectable levels.
Table 3-12.  Processes to Significantly Reduce Pathogens
           (PSRPs) Listed in Part 503

1. Aerobic Digestion
Sewage sludge is agitated with  air or oxygen to maintain aerobic
conditions for a specific mean cell residence time (i.e., solids
retention time) at a specific temperature. Values for the mean cell
residence time and temperature shall be between 40 days at 20°C
(68°F) and 60  days at 15°C (59°F).

2. Air Drying
Sewage sludge is dried on sand beds or on paved or unpaved
basins.  The sewage sludge dries for a minimum of 3 months.
During 2 of the 3 months, the ambient average daily temperature
is above 0°C (32°F).

3. Anaerobic Digestion
Sewage sludge is treated in the absence of air for a specific
mean cell residence time  (i.e., solids retention time) at a specific
temperature. Values for the mean cell residence time and
temperature shall be between 15 days at 35°C to 55°C (131°F)
and 60  days at 20°C (68°F).

4. Composting
Using either the within-vessel, static aerated pile, or windrow
composting methods, the  temperature of the sewage sludge is
raised to 40°C (104°F) or higher and remains  at 40°C (104°F) or
higher for 5 days. For 4 hours during the 5-day period, the
temperature in the compost pile exceeds 55°C (131°F).

5. Lime Stabilization
Sufficient lime  is added to the sewage sludge  to raise the pH of
the sewage sludge to 12 after 2 hours of contact.
Alternative 3: Use of a Process Equivalent to a PSRP

Alternative 3 states that sewage sludge treated by any
process determined to be equivalent to a PSRP by the
permitting authority  is considered to be a Class B sew-
age sludge. To assist the permitting authority in making
determinations, the EPA's Pathogen Equivalency Com-
mittee (PEC)  serves as a resource, providing recom-
mendations on the equivalency of processes; the PEC
also  provides  guidance to the  regulated  community.
Equivalency determinations can be made on a site-spe-
cific or national basis. Processes recommended in Part
257 as equivalent (a partial list is provided in Table 3-13)
should yield sewage sludge that meets Class B patho-
gen requirements.
Table 3-13.  Selected Processes Recommended as Equivalent
           to PSRP Under Part 2571
Operator
Process Description
Town of Telluride,   Combination oxidation ditch, aerated storage,
Colorado          and drying process. Sewage sludge is treated
                 in an oxidation ditch for at least 26 days and
                 then stored in an aerated holding tank for up
                 to a week. Following dewatering to 18%
                 solids, the sewage sludge is dried on a paved
                 surface to a depth of 2 feet (0.6 m). The
                 sewage sludge is turned over during drying.
                 After drying to 30% solids, the sludge is
                 stockpiled prior to land application. Together,
                 the drying and stockpiling steps take
                 approximately 1  year.  To ensure that PSRP
                 requirements are met, the stockpiling  period
                 must include one full summer season.

Comprehensive    Use of cement kiln dust (instead of lime) to
Materials          treat sewage sludge by raising sewage sludge
Management, Inc.  pH to at least 12 after 2 hours of contact.
Houston, Texas    Dewatered sewage sludge is mixed with
                 cement kiln dust in an enclosed system.

N-Viro Energy     Use of cement kiln dust and lime kiln dust
Systems, Ltd.      (instead of lime) to treat sewage sludge by
Toledo, Ohio       raising the pH. Sufficient lime or kiln dust is
                 added to sewage sludge to produce a pH of
                 12 for at least 12 hours of contact.

Public Works      Anaerobic digestion of lagooned sewage
Department       sludge. Suspended solids had  accumulated in
Everett,           a 30-acre (12-hectare) aerated lagoon that
Washington       had been used to aerate wastewater. The
                 lengthy detention time in the lagoon (up to 15
                 years) resulted in a level of treatment
                 exceeding that provided by conventional
                 anaerobic digestion. The percentage of fresh
                 or relatively unstabilized sewage sludge was
                 very small compared to the rest of the
                 accumulation (probably much less than 1% of
                 the whole).

Haikey Creek      Oxidation ditch treatment plus storage.
Wastewater       Sewage sludge  is processed in aeration
Treatment Plant    basins followed  by storage in aerated sludge
Tulsa, Oklahoma   holding tanks. The total sewage sludge
                 aeration time is  greater than the aerobic
                 digestion operating conditions specified in the
                 Part 503 regulation of 40 days at 20°C (68°F)
                 to 60 days at 15°C (59°F). The oxidation ditch
                 sludge is then stored in batches for at least
                 45 days in an unaerated condition or  30 days
                 under aerated conditions.

Ned K. Burleson &  Aerobic digestion for 20 days at 30°C (86°F)
Associates, Inc.    or 15 days at 35°C (95°F).
Fort Worth, Texas

1 All processes were recommended for site-specific equivalency, ex-
 cept the  N-Viro  System,  which was recommended for national
 equivalency.
                                                         19

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3.4.2  Vector Attraction Reduction
        Requirements

Subpart D in Part 503 establishes 10 options for dem-
onstrating that sewage sludge that is land applied meets
requirements for vector attraction reduction  (Table 3-14).
The options  can be divided into two general approaches
for controlling the spread of disease via vectors (such
as insects, rodents, and birds):

• Reducing  the attractiveness of the sewage sludge to
  vectors (Options 1 to  8).

• Preventing vectors from coming into contact with the
  sewage sludge (Options 9 and 10).

Compliance  with  the vector attraction reduction require-
ments using  one of the options described below must be
demonstrated  separately from compliance with require-
ments for reducing pathogens in sewage sludge. Thus,
demonstration of adequate vector attraction reduction does
not demonstrate achievement of  adequate pathogen
reduction. Part 503 vector attraction reduction require-
ments are summarized below; for a detailed discussion
of vector attraction requirements, see U.S. EPA(1992b).
3.4.2.1   Option 1: Reduction in Volatile Solids
          Content

Under this option, vector  attraction is reduced if the
mass of volatile solids in the sewage sludge is reduced
by at least 38 percent during the treatment of the sew-
age sludge. This percentage  is the amount of volatile
solids reduction that can be attained  by anaerobic or
aerobic digestion plus any additional volatile solids re-
duction that occurs before the sewage sludge leaves the
treatment works, such as through  processing in drying
beds or lagoons, or when sewage sludge is composted.
Table 3-14.  Summary of Vector Attraction Reduction Requirements for Land Application of Sewage Sludge Under Part 503
           (U.S. EPA 1992b)
Requirement   What Is Required?
     Most Appropriate For:
Option 1       At least 38% reduction in volatile solids during sewage
503.33(b)(1)    sludge treatment
Option 2       Less than 17% additional volatile solids loss during
503.33(b)(2)    bench-scale anaerobic batch digestion of the sewage
              sludge for 40 additional days at 30°C to 37°C (86°F to
              99°F)

Option 3       Less than 15% additional volatile solids reduction during
503.33(b)(3)    bench-scale aerobic batch digestion for 30 additional days
              at 20°C (68°F)

Option 4       SOUR at 20°C (68°F) is <1.5 mg oxygen/hr/g total
503.33(b)(4)    sewage sludge solids


Option 5       Aerobic treatment of the sewage sludge for at least  14
503.33(b)(5)    days at over 40°C (104°F) with an average temperature
              of over 45°C (113°F)

Option 6       Addition of sufficient alkali to raise the pH to at least 12 at
503.33(b)(6)    25°C (77°F) and  maintain a pH >12 for 2 hours and a pH
              >11.5 for 22 more hours

Option 7       Percent solids >75% prior to mixing with other materials
503.33(b)(7)


Option 8       Percent solids >90% prior to mixing with other materials
503.33(b)(8)


Option 9       Sewage sludge is injected into soil so that no significant
503.33(b)(9)    amount of sewage sludge is present on the land surface
              1 hour after injection, except Class A sewage sludge
              which must be injected within 8 hours after the pathogen
              reduction process.

Option 10      Sewage sludge is incorporated into the soil within 6  hours
503.33(b)(10)   after application to land. Class A sewage  sludge  must be
              applied to the land surface within 8 hours after the
              pathogen reduction process, and must be incorporated
              within 6 hours after application.
     Sewage sludge processed by:
     • Anaerobic biological treatment
     • Aerobic biological treatment
     • Chemical oxidation

     Only for anaerobically digested sewage sludge
     Only for aerobically digested sewage sludge with 2% or less
     solids—e.g., sewage sludge treated in extended aeration
     plants

     Sewage sludge from aerobic processes (should not be used
     for composted sludges). Also for sewage  sludge that has
     been deprived of oxygen for longer than 1-2 hours.

     Composted sewage sludge (Options 3 and 4 are likely to be
     easier to meet for sewage sludge from other aerobic
     processes)

     Alkali-treated sewage sludge (alkalies include lime, fly ash,
     kiln dust, and wood ash)


     Sewage sludges treated by an aerobic or anaerobic process
     (i.e., sewage sludges that do not contain  unstabilized solids
     generated in primary wastewater treatment)

     Sewage sludges that contain unstabilized solids generated
     in primary wastewater treatment (e.g., any heat-dried
     sewage sludges)

     Liquid sewage sludge applied to the land. Domestic septage
     applied to agricultural land, a forest, or a  reclamation site
     Sewage sludge applied to the land. Domestic septage
     applied to agricultural land, forest, or a reclamation site.
                                                        20

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3.4.2.2   Option 2: Additional Digestion of
         Anaerobically Digested Sewage Sludge

Under this option, an anaerobically digested sewage
sludge is considered to have achieved satisfactory vec-
tor attraction reduction if it loses less than 17 percent
additional volatile solids when it is anaerobically batch-
digested in the laboratory in a bench-scale unit at 30° to
37°C  (86° to 99°F) for an additional 40 days.

Frequently, sewage sludge is recycled through the bio-
logical wastewater treatment section  of a treatment
works or resides for long periods of time in the waste-
water collection system. During this time it undergoes
substantial biological degradation. If it is subsequently
treated by anaerobic digestion for a period of time, it is
adequately reduced in vector attraction; however,  be-
cause sewage sludge enters the digester already par-
tially  stabilized,   the  volatile  solids reduction after
treatment is frequently less than 38%.  The additional
digestion test is  used  to demonstrate that the sewage
sludge is indeed satisfactorily reduced in vector attraction.

3.4.2.3   Option 3: Additional Digestion of
         Aerobically  Digested Sewage Sludge

Under this option,  an  aerobically  digested  sewage
sludge with 2  percent or less solids is  considered to
have achieved satisfactory vector attraction reduction if
it loses  less than 15  percent additional  volatile solids
when  it is aerobically batch-digested in the laboratory in
a bench-scale unit at 20°C (68°F) or higher for an addi-
tional  30 days. This test can be run on sewage sludge
with up to 2 percent solids and does  not  require  a
temperature correction for sewage sludge not initially
digested at 20°C. Sewage sludge with  greater than  2
percent  solids  can be diluted to 2  percent solids with
effluent,  and the  test  can then be run  on the diluted
sludge.

This option is appropriate for aerobically digested sew-
age sludge, including sewage sludge from  extended
aeration  and oxidation ditch plants where the nominal
residence time of sewage sludge leaving the wastewa-
ter treatment processes generally exceeds 20 days. In
these  cases, the sewage sludge may already have been
substantially reduced in biological degradability prior to
aerobic digestion.

3.4.2.4   Option 4: Specific Oxygen Uptake Rate
         (SOUR) for Aerobically Digested Sewage
         Sludge  Treated in an Aerobic Process

For sewage sludge treated in an aerobic process (usu-
ally aerobic digestion), reduction in vector attraction can
also be demonstrated if the SOUR of the sewage sludge
to be  land applied is  equal to or less than  1.5 mg of
oxygen per hour per gram of total sewage sludge solids
(dry-weight basis) at 20°C (68°F). The basis of this test
is that if the sewage sludge consumes very little oxygen,
its value  as a food source for vectors  is very low and
thus vectors are unlikely to be attracted to the sewage
sludge.
Frequently, aerobically digested sewage sludge is circu-
lated through the aerobic biological wastewater treat-
ment process for as long as 30 days.  In these cases,
the sewage sludge entering the aerobic digester is al-
ready partially digested, which makes it difficult to dem-
onstrate the 38  percent reduction required by Option 1;
Option 4 provides an  alternative to the percent solids
method for demonstrating vector attraction reduction.
The oxygen uptake rate depends on the conditions of
the test  and, to some degree, on the nature of the
original  sewage sludge  before  aerobic treatment.  It
should be noted that the SOUR method may be unreli-
able at solids content above 2 percent.

3.4.2.5   Option 5: Aerobic Processes at Greater
         Than  40°C
Under this option, the sewage  sludge  must  be treated
for 14 days or longer, during which time the temperature
must be over 40°C (104°) and the average temperature
higher than 45°C (113°F). This option applies primarily
to  composted sewage sludge, which generally contains
substantial amounts  of partially decomposed organic
bulking agents.
This option can  be applied to sewage sludge from other
aerobic processes, such as aerobic digestion, but other
approaches for demonstrating compliance (e.g., those
described in Options 3 and 4) are likely to be easier to
meet for these types of sewage sludge.

3.4.2.6   Option 6: Addition of Alkali
Under this option, sewage sludge is considered to be
adequately reduced in vector attraction  if sufficient alkali
is added  to:
• Raise the pH to at least 12.
• Maintain a pH of at least 12 without addition of more
  alkali for 2 hours.
• Maintain a pH of at least 11.5 without addition of more
  alkali for an additional 22 hours.
The conditions  required under this option  are intended
to  ensure that the sewage sludge can  be  stored for at
least several days at the treatment works, transported,
and then land applied without the pH falling to the point
where putrefaction occurs and vectors  are attracted.

3.4.2.7   Option 7: Moisture Reduction  of Sewage
         Sludge Containing No Unstabilized Solids
Under this option, sewage sludge vector attraction is
considered to be reduced  if the sewage sludge does not
                                                  21

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contain  unstabilized  solids generated during  primary
wastewater treatment and if the  solids content of the
sewage sludge is greater than or equal to 75  percent
before the sewage sludge is mixed with other materials.
Thus, the reduction  must be  achieved by removing
water, not by adding inert materials.

It is important that the sewage sludge meeting Option 7
not contain unstabilized solids because the partially de-
graded food  scraps likely to be present in such  sewage
sludge would attract birds, some mammals, and possi-
bly insects,  even if the  solids content of the  sewage
exceeded 75  percent. Additionally, steps should  be
taken to prevent exposure of stored sewage sludge to
high humidity, which  could cause its  outer surface to
equilibrate to a lower  solids content  and attract  vectors.

3.4.2.8   Option 8: Moisture Reduction of Sewage
         Sludge Containing Unstabilized Solids

Vector attraction of any sewage sludge is considered to
be adequately reduced if the solids content of the sludge
is  increased to 90 percent  or greater. This extreme
desiccation deters vectors in all but the most  unusual
situations. The solids increase must  be achieved  by
removal of water and not  by dilution  with inert solids.
Drying to this  extent severely limits biological activity
and strips off or decomposes the volatile compounds
that attract vectors.

3.4.2.9   Option 9: Injection of Sewage Sludge

Vector attraction reduction can be demonstrated by in-
jecting the sewage sludge below the ground. Under this
option, no significant amount of the sewage sludge can
be present on the land surface within 1 hour after injec-
tion. If the sludge is Class A with respect to pathogens,
it must be injected within 8 hours after discharge  from
the pathogen-reduction process; special restrictions ap-
ply to Class  A sewage sludge because it is a  medium
for regrowth, and after 8 hours pathogenic bacteria may
rapidly increase.

Injection of sewage sludge beneath the soil places a bar-
rier of earth between the sewage sludge and vectors. The
soil quickly removes water from the sewage sludge, which
reduces the mobility and odor of the sewage sludge.

3.4.2.10   Option 10: Incorporation  of Sewage
          Sludge into the Soil

Under this option, sewage sludge applied to the land
surface must be incorporated into the soil within 6 hours.
If the sewage sludge  is Class A with respect to patho-
gens, the time between processing and application  must
not exceed 8 hours.

When applied at agronomic rates, the loading of sewage
sludge solids typically is approximately 1/200th or less
of the mass of soil in the plow layer. If  mixing is reason-
ably good, the dilution of sewage sludge in the soil
surface is equivalent to that achieved with soil injection.
Initial vector attraction will diminish and be virtually elimi-
nated when the sewage sludge is mixed with the soil.

3.5   Frequency of Monitoring

The Part 503 rule requires that pollutant concentrations
(for metals), pathogen densities,  and vector attraction
reduction  be monitored  and analyzed when sewage
sludge is land applied. Monitoring is intended to ensure
that the land-applied  sewage sludge meets applicable
criteria after its quality has been initially demonstrated.

Part 503 specifies  how often sewage sludge must be
monitored and lists the analytical methods to be used
for analyzing different types of samples. The frequency
of monitoring requirements range from 1 to 12 times per
year, depending on the amount of sewage sludge (in
metric tons, dry-weight basis) applied to a site. Require-
ments for monitoring  must be  met regardless of which
approaches  are  used for meeting pollutant limits and
pathogen and vector attraction reduction requirements.
Frequency of monitoring requirements are  summarized
in Table 3-15. For frequency of monitoring requirements
for stored sewage sludge, contact the permitting authority.

3.6   Recordkeeping and Reporting

The person who prepares sewage sludge for land appli-
cation must provide information necessary to demon-
strate compliance with  the Part 503 rule to  the  land
applier, and the person who applies the sewage sludge
to the land is responsible for obtaining from the preparer
information necessary to demonstrate compliance with
the rule.  For a discussion of specific Part 503 record-
keeping and reporting requirements, see Chapter 15.

3.7   Sewage Sludge Quality and  the Part
      503 Requirements

The Part 503 requirements that must be complied with
depend on the  quality of the sewage sludge, in terms of
pollutants, pathogen levels, and vector attraction reduc-
tion control. These quality differences are discussed
below and are  summarized in Table 3-16.

3.7.1  Exceptional Quality (EQ) Sewage Sludge

Sewage sludge that meets the Part 503 ceiling concen-
tration limits, pollutant concentration limits, one of the
Class A pathogen reduction alternatives, and one of the
vector attraction reduction options described above can
be considered "exceptional quality" (EQ) sewage sludge.3
Sewage sludge meeting these EQ requirements are not
 The sewage  sludge quality designation "exceptional quality" is
 based on interpretations of the Part 503 rule, which does not explic-
 itly use this term.
                                                  22

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Table 3-15.  Frequency of Monitoring for Pollutants, Pathogen Densities, and Vector Attraction Reduction

                                             Amount of Sewage Sludge (U.S. tons)
Amounts of Sewage Sludge3
(metric tons per 365-day period)
Greater than zero but less than 290
Equal to or greater than 290 but
less than 1 ,500
Equal to or greater than 1 ,500 but
less than 15,000
Equal to or greater than 1 ,5000
Ave. per day
>0 to <0.85
0.85 to <4.5
4.5 to <45
>45
per 365 days
>0 to <320
320 to <1 ,650
1,650to <1 6,500
>1 6,500
Frequency
Once per year
Once per quarter
(4 times per year)
Once per 60 days
(6 times per year)
Once per month
(12 times per year)
 Either the amount of bulk sewage sludge applied to the land or the amount of sewage sludge received by a person who prepares sewage
 sludge for sale or give-away in a bag or other container for application to the land (dry-weight basis).


Table 3-16.  Summary of Part 503 Requirements for Different Types of Sewage Sludge
Type of
Sewage
Sludge3
"Exceptional
Quality"
(Bag or Bulk)
Pollutant
Concentration
(Bulk Only)
CPLR
(Bulk Only)

APLR
(Bag Only)

Ceiling Other
Concentration Pollutant
Limit Limits
Yes Pollutant
Concentration
Limits
Yes Pollutant
Concentration
Limits
Yes Cumulative
Pollutant
Loading
Rates
(CPLRs)
Yes Annual
Pollutant
Loading
Rates
(APLRs)
Vector
Pathogen Attraction
Class Reduction
A 1 of
Options
1-8b
B 1 of
Options
1-10
A or B 1 of
Options
1-10

A 1 of
Options
1-8

Siting
Restrictions
No
Yes

No if
Pathogen
Class A
Yes if
Pathogen
Class B
No


General
Requirements,
Management
Practices
Nob
Yes

Yes


Yesc


Track
Added
Pollutants
No
No

Yes


No


 All sewage sludge must also meet Part 503 frequency of monitoring requirements and recordkeeping and reporting requirements.
b If sewage sludge instead follows vector attraction reduction options 9 or 10 (incorporation or injection), the sewage sludge must also meet
 Part 503 general requirements and management practices, and would not be considered "exceptional quality" sewage sludge.
c Only two general requirements and a management practice requirement for labeling must be met.
subject to Part 503's land application general require-
ments and management practices. EQ sewage sludge
can be applied as freely as any other fertilizer or soil
amendment to any type of land (unless EPA or the
director of an  EPA-approved state sludge program de-
termines that  in a particular case, when bulk sewage
sludge  is land applied, the Part 503 general require-
ments or management practices are needed to protect
public health and  the  environment).  Although  the Part
503  rule does not require EQ sewage  sludge to be
applied at the agronomic rate for nitrogen (which is  a
requirement for sewage sludge not meeting EQ require-
ments), for good management EQ sewage sludge, like
any type of fertilizer, also should be applied at the agro-
nomic rate,  which supplies the nitrogen needs  of the
crop or vegetation  grown on the site and protects ground
water.
To  achieve EQ  sewage sludge  quality,  the user  or
preparer of sewage sludge must:

• Not exceed the Part 503 ceiling concentration limits
  and pollutant concentration limits for regulated metals
  (Table 3-4).

• Meet one of the six Part 503 Class A pathogen re-
  duction alternatives  (Table 3-6) and required bacterial
  monitoring (Table 3-7).

• Meet one of the first eight Part 503 vector attraction
  reduction options (Table 3-14).

• Comply  with the Part 503 frequency  of  monitoring
  (Table  3-15)  and  recordkeeping/reporting require-
  ments (see Chapter 15).
                                                     23

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The Part 503 general  requirements and management
practices do not apply to EQ sewage sludge unless they
are deemed necessary for bulk sewage sludge, as dis-
cussed above.

3.7.2  Pollutant Concentration (PC) Sewage
       Sludge

"Pollutant Concentration" (PC) sewage sludge meets
the same low  pollutant limits as EQ sewage sludge, but
usually meets Class B rather than Class A pathogen
reduction requirements. Sewage  sludge meeting Class
A pathogen reduction requirements and vector attraction
options  9 or  10  (which do not  qualify as  EQ vector
requirements) also is PC sewage sludge. If PC sewage
sludge is Class  B pathogen  status, it must be land
applied according to specific site restrictions discussed
in Table 3-11 to prevent exposure to the sewage sludge.
Sewage sludge that meets PC criteria can be applied to
all types of land,  except lawns and home gardens,  if
these site restrictions are observed. To achieve PC sew-
age sludge quality, the sewage sludge must:

• Not exceed the Part 503 ceiling  concentration limits
  and pollutant concentration limits  for regulated metals
  (Table 3-4).

• Meet one of three Part 503 Class B pathogen reduc-
  tion alternatives (Table 3-6)  and  Class B site restric-
  tions (Table 3-11).

• Meet one of 10 applicable Part 503 vector attraction
  reduction options (Table 3-14).

• Comply with the Part 503 frequency of monitoring
  (Table  3-15)  and recordkeeping/reporting  require-
  ments (see Chapter 15).

• Comply with certain Part 503  general requirements
  (Table 3-17) and management practices (Table 3-5).

3.7.3  Cumulative Pollutant Loading Rate
       (CPLR) Sewage Sludge

"CPLR"  sewage sludge must meet more  Part 503 re-
quirements than  EQ or PC sewage sludge. These re-
quirements, such  as  tracking  of cumulative  metal
loadings, ensures adequate protection of public health
and the environment.  CPLR sewage sludge users or
preparers must:

• Not exceed the Part 503 ceiling  concentration limits
  and cumulative pollutant loading rate (CPLR) limits
  for regulated metals (Table 3-4) when the sewage
  sludge is land applied in  bulk.

• Meet either Part 503 Class A or Class B pathogen
  reduction requirements (Table 3-6)  and related re-
  quirements  (either Table  3-7 or Table 3-11).

• Meet one of 10 Part 503 vector attraction reduction
  options (Table 3-14).
• Comply with Part 503 frequency of monitoring (Table
  3-15) and recordkeeping/reporting requirements (see
  Chapter 15).

• Comply with certain Part 503 general requirements
  (Table 3-17) and management practices (Table  3-5).

3.7.4  Annual Pollutant Loading Rate (APLR)
       Sewage Sludge

"APLR" sewage sludge, which pertains only to sewage
sludge sold or given away in a bag or other container for
application to  land ("bagged" sewage sludge),  must
meet Class A pathogen reduction requirements and one
of the vector  attraction  reduction  treatment  options.
These provisions are  required because of the  high po-
tential for human contact at sites where bagged sewage
sludge is likely to be  applied (i.e.,  public contact  sites
such as parks). APLR sewage sludge users or preparers
must:

• Not exceed the Part 503 ceiling  concentration limits
  and annual pollutant loading rate  (APLR) limits for
  regulated metals (Table 3-4) when the sewage sludge
  is placed in a bag  or other container,  as defined in
  Part 503, for sale or given away for application to the
  land.

• Meet Part 503 Class A pathogen reduction  require-
  ments (Table  3-6) and required bacterial monitoring
  (Table 3-7).

• Meet one of the first eight Part 503 vector attraction
  reduction options (Table 3-14).

• Meet the Part 503 management practice that requires
  a label or  information sheet that lists data specified
  in Part 503 (Table 3-5).

• Meet the Part 503 frequency of monitoring (Table
  3-15) and recordkeeping/reporting requirements (see
  Chapter 15).

• Meet  the   Part  503  general  requirements   (Part
  503.12(a) and (e)(i)).

The  Part  503  labelling provision  requires that the
preparer of APLR sewage sludge  provide the applier
with allowable application rate information, either  on a
label or in a  handout (usually based on the  nutrient
content of the sewage sludge). This information  is based
on the preparer's calculation of the annual whole sludge
application rate (AWSAR) (Table 3-18). The preparer/
manufacturer also provides the applier with information
on the nutrient value of the bagged sewage sludge. The
recommended application rate helps ensure  that the
sewage sludge is applied at the appropriate agronomic
rate to minimize the  amount of excess nitrogen  that
passes below the root zone and into ground water.
                                                 24

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Table 3-17.  Part 503 Land Application General Requirements
For EQ Sewage Sludge

None (unless set by EPA or state permitting authority on a
case-by-case basis for bulk sewage sludge to protect public health
and the environment).

For PC and CPLR Sewage Sludge

The prepare!3 must notify  and provide information necessary to
comply with the Part 503 land application requirements to the
person who applies bulk sewage sludge to the land.

The preparer who provides sewage sludge to another person who
further prepares the sewage sludge for application to the land
must provide  this person with notification and information
necessary to  comply with the Part 503 land application
requirements.

The preparer must provide written notification of the total nitrogen
concentration (as N on a dry-weight basis) in bulk sewage sludge
to the applier of bulk sewage sludge to agricultural land, forests,
public contact sites, or reclamation sites.

The applier of sewage sludge must obtain information necessary
to comply with the Part 503 land application requirements, apply
sewage sludge to the land  in accordance with the  Part 503 land
application requirements, and provide  notice and relevant
information to the owner or lease holder of the land on which
sewage sludge is applied.

Out-of-State  Use

The preparer must provide written notification (prior to the initial
application of the bulk sewage sludge  by the applier) to the
permitting authority in the state where  sewage sludge is proposed
to be  land applied when bulk sewage  sludge is generated in one
state (the generating state) and transferred to another state (the
receiving state) for application to the land. The notification must
include:

• the location (either street  address or  latitude and  longitude) of
 each land application site;

• the approximate time period the bulk sewage sludge will be
 applied to the site;

• the name, address, telephone number, and  National Pollutant
  Discharge Elimination  System (NPDES) permit number for both
 the preparer and the applier of the bulk sewage sludge; and
• additional information or permits in both states, if required by the
  permitting authority.

Additional Requirements for CPLR Sewage Sludge

The applier must notify the permitting authority in  the state where
bulk sewage sludge is to be applied prior to the initial application
of the sewage sludge. This is a one-time notice requirement for
each land application site each time there is a new applier. The
notice must include:

• the location (either street address or latitude and  longitude) of the
  land application site; and

• the name, address, telephone number, and NPDES permit
  number (if appropriate) of the person who will apply the bulk
  sewage sludge.

The applier must obtain records (if available) from the previous
applier or landowner that indicate the  amount of each CPLR
pollutant  in sewage sludge that have been applied to the site since
July 20, 1993. In addition:

• when CPLR sewage sludge was previously applied since July 20,
  1993 to the  site and cumulative amounts of regulated pollutants
  are known, the applier must use this information  to determine the
  additional amount of each pollutant that can be applied to the site
  in accordance with the CPLRs in Table 3-4;

• the applier must keep the previous records and also record the
  additional amount of each pollutant he or she is applying to
  the site; and

• when CPLR sewage sludge was previously applied to the site
  and cumulative amounts of regulated pollutants are not known, no
  additional sewage sludge meeting  CPLRs can be applied to that
  site. However, EQ or PC sewage sludge could be applied.

If sewage sludge meeting CPLRs has not been applied to the site
in excess of the limit since July 20, 1993, the CPLR limit for each
pollutant  in Table 3-4 will determine  the maximum  amount of each
pollutant  that  can be applied if the applier keeps a record of the
amount of each pollutant in sewage sludge applied to any given
site.

The applier must not apply additional sewage sludge under the
cumulative pollutant loading concept to a site where any of the
CPLRs have been reached.
 The preparer is either the person who generates the sewage sludge or the person who derives a material from sewage sludge. This includes
 the person who prepares sewage sludge for sale or give-away in a bag or other container for application to the land.
                                                              25

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Table 3-18.  Procedure to Determine the Annual Whole Sludge Application Rate for Sewage Sludge Sold or Given Away in a Bag
            or Other Container for Application to Land

1. Analyze a sample of the sewage sludge to determine the concentration of each of the  10 regulated metals in the sewage sludge.

2. Using the pollutant concentrations from Step 1 and the APLRs from Table 3-4, calculate an AWSAR for each pollutant using the following
equation:
where:
  AWSAR = Annual whole sludge application rate (dry metric tons of sewage sludge/hectare/year)
  APLR = Annual pollutant loading rate (in Table 3-4) (kg of pollutant/ha/yr)
  C= Pollutant concentration (mg of pollutant/kg of sewage sludge, dry weight)
  0.001 = A conversion factor

3. The AWSAR for the sewage sludge is the lowest AWSAR calculated for each pollutant in Step 2.

Example:

a. Sewage sludge to be applied to land is analyzed for each of the 10 metals regulated in Part 503. Analysis of the sewage sludge
indicates the  pollutant concentration in the second column of the table below.

b. Using these test results and the APLR for each pollutant from Table 3-4, the AWSAR for all the pollutants are calculated as shown in the
fourth column of the table below.

c. The AWSAR for the sewage sludge is the lowest AWSAR calculated for all 10 metals. In our example, the  lowest AWSAR is for copper
at 20  metric tons of sewage sludge/hectare/year. Therefore, the AWSAR to be used for this sewage sludge is 20 metric tons per
hectare/year. The 20 metric tons of sewage sludge/hectare is the same as 41 0 pounds of sewage sludge/1 ,000 square feet (20 metric tons
x 2,205 Ib per metric ton/107,600 square feet per hectare). The AWSAR on the label or information sheet would have to be equal to or less
than 410 pounds per 1,000 square feet.
                                                                                            AWSAR =
Metal
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
oevvdye oiuuye
Concentrations
(milligrams/kilogram)
10
10
1,000
3,750
150
2
—
100
15
2,000
«ri_r^
(kilograms/
hectare/year)
2.0
1.9
150
75
15
0.85
—
21
5.0
140
Cone, in Sewage Sludge (0.001)
2/(10 x 0.001)
1.97(10x0.001)
1507(1,000x0.001)
757(3,750x0.001)
157(150x0.001)
0.857(2x0.001)
—
217(100 x 0.001)
57(15 x 0.001)
140/(2,000x 0.001)
;u 11. iuii:>/ iicuidic/ ye
= 200
= 190
= 150
= 20
= 100
= 425

= 210
= 333
= 70
 Annual pollutant loading rates from Table 3-4 of this guide and Table 4 of the Part 503 rule. The APLR for molybdenum does not have to be
 met while EPA is reconsidering this value.


3  8   References                                        u-s- EPA- 1994- A P'ain English guide to the EPA Part 503 biosolids
                                                                  rule. EPA/832/R-93/003. Washington, DC.

When an NTIS number is cited in a  reference, that         u.s. EPA. I992a. Technical support document for land application of
document is available from:                                     sewage sludge, Vol. 1. EPA/822/R-93/018a (NTIS PB93110575).
    National Technical Information Service                     Washington, DC.

    5285 Port Royal Road                                    u s ERA 1992b  Environmental regulations and technology: Control
    Springfield, VA 22161                                        of pathogens and vector attraction in sewage sludge. EPA/625/R-
    703-487-4650                                               92/013. Washington, DC.
                                                           26

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                                             Chapter 4
                              Characteristics of Sewage Sludge
4.1   Introduction

Determining the suitability of sewage sludge for land ap-
plication by characterizing its properties is a necessary first
step in planning and designing a land application system.
The composition  of sewage sludge will have important
bearing on the following design decisions:

• Whether the sewage sludge can be cost-effectively
  applied to land.

• Which land  application practice (i.e.,  application to
  agricultural,  forest,  reclamation  or  public contact
  sites)  is technically feasible.

• The quantity of sewage sludge to be applied per unit
  area,  both annually and cumulatively.

• The degree  of regulatory control and  system moni-
  toring required.

Important properties of sewage sludge that need to be
characterized include:

• Quantity

• Total solids content

• Volatile solids content

• pH

• Organic matter

• Pathogens

• Nutrients

• Metals

• Organic chemicals

• Hazardous pollutants, if any

Sewage sludge composition depends principally  on the
characteristics of the wastewater influent entering the
wastewater treatment works and the treatment proc-
esses used. Generally,  the more industrialized a com-
munity is, the greater the possibility that heavy  metals
may pose a potential problem for land  application of
sewage sludge.  Industrial pretreatment requirements
(40 CFR Part 403) and pollution prevention programs,
as well as advances in wastewater and sewage  sludge
treatment processes, generally have reduced the levels
of pollutants in the final sewage sludge leaving a treat-
ment works. Figure 4-1 shows the basic wastewater and
sewage sludge generation and treatment process.

This chapter describes the properties of sewage sludge
to be characterized, the different types of sewage sludge
(which exhibit different characteristics), and the effects
that wastewater and sewage sludge treatment proc-
esses and  pretreatment  have  on sewage  sludge
characteristics. The information provided is intended
primarily for illustrative purposes.  While  the data are
useful in preliminary planning, analysis of the actual
sewage sludge to be land-applied is necessary for de-
sign purposes. The chemical composition  of sewage
sludge may vary greatly between wastewater treatment
works and also overtime at a single plant. This variabil-
ity in sewage sludge composition underscores the need
for a sound sampling program (e.g., analysis of a sub-
stantial number of sewage sludge samples over a period
of 2 to 6 months or longer) to provide a reliable estimate
of sewage sludge composition. Sampling is discussed
in Chapters 6 and 13.

4.2   Sewage Sludge Quantity

The amount of sewage sludge to be  land applied will
affect site  evaluation and design in several important
ways, including land area needs, size of transportation
equipment and storage facilities, and cost. Quantities of
sewage sludge available also will affect the selection of
land application  practices (i.e., application at  agricul-
tural, forest, reclamation or public contact sites), as well
as application rates and operating schedules.

Sewage sludge quantity can be measured in two ways:
the  volume of the wet sewage sludge, which includes
the water content and solids content, or the mass of the
dry  sewage sludge  solids. Sewage sludge volume is
expressed  as  gallons (liters) or cubic meters, while
sludge mass usually is expressed in terms of weight, in
units  of dry metric tons (tonnes).  Because  the water
content of sewage sludge can be high and quite vari-
able,  the mass of dry sludge solids  is often used to
compare sewage sludges with different proportions of
water (U.S. EPA, 1984).
                                                  27

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      SEWAGE SLUDGE
                DOMESTIC
                SEWAGE
                GENERATION
                            INDUSTRIAL
                            WASTEWATER
                            GENERATION
                                                                            TREATED*  USE
                                                                            SEWAGE
                                                                            SLUDGE
                                                                                       Land Application

                                                                                       • Agricultural land
                                                                                       • Strip-mined land
                                                                                       • Forests
                                                                                       • Plant nurseries
                                                                                       • Cemeteries
                                                                                       • Parks, gardens
                                                                                       • Lawns and home
                                                                                        gardens
       DOMESTIC SEPTAGE
                                    RAW
                               )    SEPTAGE\

                             r     "v
SEPTIC TANKS
                              PUMPING
                                AND
                              HAULING
                                           COTREATMENT
                                                WITH
                                           WASTEWATER
                                              AND/OR
                                          SEWAGE SLUDGE
                                                   SEPTAGE
                                                  TREATMENT
TREATED
SEWAGE
SLUDGE/
SEPTAGE
Figure 4-1.  Generation, treatment, use, and disposal of sewage sludge and domestic septage.
                                                      28

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Key factors affecting sewage sludge volume and mass
are wastewater sources and wastewater and sludge
treatment processes. For example, industrial contribu-
tions to wastewater influent streams  can significantly
increase the sewage sludge quantity generated from a
given amount of wastewater. Also,  higher degrees
of wastewater treatment generally increase sewage
sludge volume. In addition, as shown in Table 4-1, some
sewage sludge treatment  processes  reduce sewage
sludge volume, some reduce sewage sludge mass, and
some increase sewage sludge mass  while improving
other sewage sludge characteristics (U.S. EPA, 1984).

4.3   Total Solids Content

The total solids (TS) content of sewage sludge includes
the suspended and dissolved solids and is usually ex-
pressed as the percent of total solids present in a sew-
age sludge. TS can affect the  potential land application
system design in several ways, including:

• Size  of transportation  and storage systems—The
  higher the solids  content, the  lower the volume of
  sewage sludge  that will have to be transported and
  stored because less water will need to be handled.

• Mode of transport—Different types  of transportation
  to the land application site (e.g., trucks, pipelines) will
  be used depending on the solids content of the sew-
  age sludge to be applied  (see Chapter 14).

• Application method and equipment—The method of
  sewage sludge  application  (e.g., surface spreading,
  injection, spray irrigation)  and the type of application
  equipment needed will vary depending on the solids
  content of the sewage sludge (see Chapter 14).

• Storage method—Different  storage  methods will be
  used  depending on solids  content (e.g., tanks  for
  liquid  sewage sludge versus stockpiles for dewatered
  sewage sludge).

In general, it is  less expensive  to transport sewage
sludge with a high solids content (dewatered sewage
sludge)  than to transport sewage sludge  with a low
solids content (liquid sewage sludge). This cost savings
in transport should be weighed against the cost of de-
watering the sewage sludge. Typically,  liquid sewage
sludge has a solids content of 2  to 12 percent solids,
while dewatered sewage sludge has a  solids content of
12 to 40 percent solids (including chemical additives).
Dried or composted  sewage sludge typically has a sol-
ids content over 50 percent.

TS content  depends on the  type of sewage sludge
(primary, secondary, or tertiary, as discussed in Section
4.12), whetherthe sewage sludge has been treated prior
to land application, and how it was treated. Treatment
processes such as thickening, conditioning, dewatering,
composting, and drying  can lower water content and
thus raise the percent solids. The efficiency of these
treatment  processes, however, can vary substantially
from time  to time, producing sewage sludge with sub-
stantially lower solids content than anticipated.  Land
application sites, therefore, should be flexibly designed
to accommodate the  range of  variations  in sewage
sludge solids content that  may occur as  a  result  of
variations  in the  efficiency of the wastewater and sew-
age sludge treatment processes. Without this flexibility,
operational problems could result at the site.


4.4   Volatile  Solids Content

Sludge volatile solids (VS) are organic compounds that
are reduced when  the  sludge  is  heated to 550°C
(1,022°F) under oxidizing conditions. The VS content of
sludge provides  an estimate of the organic content  of
the material. VS content is most often expressed as the
percent of total solids that are volatile solids.  VS is an
important determinant of potential odor problems at land
application sites. Reduction of VS is  one option in the
Part 503 regulation for meeting vector attraction reduc-
tion requirements (see Chapter 3). Most  unstabilized
sewage sludge contains 75 percent to 85 percent VS on
a dry weight basis. A number of treatment processes,
including anaerobic digestion, aerobic digestion,  alkali
stabilization, and composting, can be used to reduce
sludge VS content and thus the  potential for odor. An-
aerobic digestion—the most common method of sludge
stabilization—generally biodegrades about 50 percent
of the volatile solids in a sewage sludge.


4.5   pH

The pH of sewage sludge can affect crop production  at
land application sites by altering the pH  of the soil and
influencing the  uptake  of  metals by  soil  and plants.
Pathogen  levels  and vector control are the major rea-
sons  for pH adjustment of sewage sludge.  Low pH
sludge  (less than approximately pH  6.5) promotes
leaching of heavy metals, while high pH sludge (greater
than pH 11)  kills many bacteria and, in conjunction with
soils of neutral or high pH, can inhibit movement  of
heavy metals through soils. Some of the Part 503 patho-
gen reduction alternatives include raised  pH levels (see
Chapters).


4.6   Organic Matter

The  relatively high level of organic matter in sewage
sludge allows the sludge to be used as a soil conditioner
to improve the physical properties of soil (e.g., increased
water infiltration  and water-holding capacity). The soil
conditioning properties of sewage sludge are especially
useful at reclamation sites such as mine spoils.
                                                  29

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Table 4-1.  Effects of Sewage Sludge Treatment Processes on Land Application Practices (U.S. EPA, 1984)

Treatment Process and Definition            Effect on Sewage Sludge                    Effect on Land Application Practices
Thickening: Low-force separation of
water and solids by gravity, flotation, or
centrifugation. (Sewage sludge thickeners
may also be used as flow equalization
tanks to minimize the effect of sewage
sludge quantity  fluctuations on subsequent
treatment processes.)

Digestion (Anaerobic and Aerobic):
Biological stabilization  of sewage sludge
through conversion of  some of the organic
matter to water, carbon dioxide, and
methane. (Digesters may also be used to
store sewage sludge to provide greater
flexibility for the treatment operation and
to  homogenize sewage sludge solids to
facilitate subsequent handling procedures.)

Alkali Stabilization: Stabilization of
sewage sludge through the addition of
alkali.
Conditioning: Alteration of sewage
sludge properties to facilitate the
separation of water from sewage sludge.
Conditioning can be performed in many
ways, e.g., adding inorganic chemicals
such as lime and ferric chloride; adding
organic chemicals such as polymers;
mixing digested sewage  sludge with water
and resettling (elutriation); or briefly raising
sewage sludge temperature and pressure
(heat treatment). Thermal conditioning
also causes disinfection.

Dewatering: High-force separation of
water and solids. Dewatering methods
include vacuum filters, centrifuges, filter
presses, belt presses, lagoons, and sand
drying beds.
Composting: Aerobic process involving
the biological stabilization of sewage
sludge in a windrow, aerated static pile,
or vessel.
Heat Drying: Application of heat to ki
pathogens and eliminate most of the
water content.
Increase solids concentration of sewage
sludge by  removing water, thereby
lowering sewage sludge volume. May
provide a blending function in combining
and mixing primary and secondary
sewage sludges.


Reduces the volatile and biodegradable
organic content and the mass of sewage
sludge by  converting it to soluble  material
and gas. May reduce volume by
concentrating solids. Reduces pathogen
levels and controls putrescibility and odor.
Raises sewage sludge pH. Temporarily
decreases biological activity. Reduces
pathogen levels and controls putrescibility.
Increases the dry solids mass of the
sewage sludge. Because pH effects are
temporary, decomposition, leachate
generation, and release of gas, odors,
and heavy metals may occur over time.

Improves sewage sludge dewatering
characteristics. Conditioning may  increase
the mass of dry solids to be handled
without increasing the organic content of
the sewage sludge. Conditioning may also
improve sewage  sludge compactability
and stabilization. Generally,  polymer-
treated sewage sludges tend to be sticky,
slick, and less workable than other
sewage sludges. Some  conditioned
sewage sludges  are corrosive.


Increases solids  concentration of  sewage
sludge by removing much of the entrained
water, thereby lowering  sewage sludge
volume. Dewatering may increase sewage
sludge solids  to 15%  to 40% for organic
sewage sludges  and  45% or more for
some inorganic sewage sludges.  Some
nitrogen and other soluble materials are
removed with the water. Improves ease of
handling by converting liquid sewage
sludge to damp cake. Reduces fuel
requirements  for heat drying.

Lowers  biological activity. Can destroy
most pathogens. Degrades sewage
sludge to a humus-like material. Increases
sewage sludge mass due to addition of
bulking agent.

Disinfects sewage sludge. Destroys most
pathogens. Slightly lowers potential for
odors and biological activity.
Lowers sewage sludge transportation
costs for all practices (e.g, agricultural,
forests, reclamation sites, public contact
sites).
Reduces sewage sludge quantity.
High pH of alkali-stabilized sewage sludge
tends to immobilize heavy metals in
sewage sludge as long as the pH levels
are maintained.
Polymer-treated sewage sludges may
require special operational considerations
at the land application site.
Reduces land requirements and lowers
sewage sludge transportation costs for all
practices.
Excellent soil conditioning properties.
Significant storage usually needed. May
contain lower nutrient levels than less
processed sewage sludge.


Greatly reduces volume of sewage sludge.
                                                              30

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4.7   Pathogens
Potential disease-causing  microorganisms  known as
pathogens, including bacteria,  viruses,  protozoa, and
eggs of parasitic worms, are often present in municipal
wastewater and raw sewage sludge. Pathogens also
are present in domestic septage. Pathogens can pre-
sent a public health hazard if they are transferred to food
crops grown on land to which sewage sludge or domes-
tic septage is applied, contained in  runoff to surface
waters from land application sites, or transported  away
from  the site  by vectors such as insects, rodents, and
birds. For this reason, Part 503 specifies pathogen re-
duction  and  vector attraction  reduction  requirements
that must be  met  by sewage  sludge applied to  land
application sites. Table 4-2 illustrates the different types
of pathogens typically found in  sewage sludge and do-
mestic septage.
Generally, sewage sludge  intended for land application
is  stabilized  by chemical or biological processes  (see
Section 4.13). Table 4-3 shows typical levels  of some
pathogens in unstabilized and stabilized sewage sludge.
Stabilization greatly reduces the number of pathogens
in  sewage sludge,  including bacteria, parasites, proto-
zoa,  and viruses (Sagik et al.,  1979), as well as  odor
potential. Nevertheless, even stabilized sewage sludge
will usually contain some pathogens;  thus the Part 503
regulation requires that specific processes  to reduce
pathogen levels be undertaken  prior to land application
and that  site  restrictions for certain  types of sewage
sludge be followed. The Part 503 pathogen and vector
attraction reduction requirements serve to protect oper-
ating personnel, the general public, crops intended for
human consumption, ground  water, and surface water
from  potential contamination by unacceptable  levels of
pathogens. Part 503 requirements also are designed to
ensure that regrowth of bacteria does not occur prior to
use or disposal. A summary of the Part 503 pathogen
and vector attraction  reduction  requirements  is  pre-
sented in Chapter 3.  For more  detailed discussions of
Table 4-3.  Typical Pathogen Levels in Unstabilized and
          Anaerobically Digested Liquid Sludges (U.S. EPA, 1979)
                         Typical           Typical
                      Concentration in   Concentration in
                        Unstabilized      Anaerobically
                         Sludge       Digested Sludge
Pathogen             (No./100 milliliters)  (No./100 milliliters)
Table 4-2.  Principal Pathogens of Concern in Municipal
          Wastewater and Sewage Sludge
Organism
Disease/Symptoms
Virus
Fecal Coliform Bacteria3
Salmonella
Ascaris lumbricoides-
Helminth
2,500
1,000
8
200
- 70,000
,000,000
,000
- 1 ,000
100
30,000
3
0
- 1 ,000
- 6,000,000
-62
- 1 ,000
Bacteria
Salmonella sp.

Shigella sp.
Vibrio cholerae
Campylobacter jejuni
Escherichia coli
(pathogenic strains)
Enteric Viruses
Hepatitis A virus
Norwalk and Norwalk-like
viruses
Rotaviruses

Enteroviruses
   Polioviruses
   Coxsackieviruses
   Echoviruses

Reovirus
Astroviruses
Calciviruses
Protozoa
Cryptosporidium
Entamoeba histolytica
Giardia lamblia

Balantidium coli
Toxoplasma gondi
Helminth Worms
Ascaris lumbricoides
Ascaris suum

Trichuris trichiura

Toxocara canis

Taenia saginata

Taenia solium

Necator americanus
Hymenolepis nana
Salmonellosis (food poisoning),
typhoid fever
Bacillary dysentery
Cholera
Gastroenteritis
Gastroenteritis
Infectious hepatitis
Epidemic gastroenteritis with severe
diarrhea
Acute gastroenteritis with severe
diarrhea
Poliomyelitis
Meningitis, pneumonia, hepatitis, fever,
cold-like symptoms, diarrhea, etc.
Meningitis, paralysis, encephalitis, fever,
cold-like symptoms, diarrhea, etc.
Respiratory infections, gastroenteritis
Epidemic gastroenteritis
Epidemic gastroenteritis

Gastroenteritis
Acute enteritis
Giardiasis (including diarrhea,
abdominal cramps, weight loss)
Diarrhea and dysentery
Toxoplasmosis
Digestive and nutritional
disturbances, abdominal pain,
vomiting, restlessness
May produce symptoms such as
coughing, chest pain, and fever
Abdominal pain, diarrhea, anemia,
weight loss
Fever, abdominal  discomfort, muscle
aches, neurological symptoms
Nervousness, insomnia, anorexia,
abdominal pain, digestive
disturbances
Nervousness, insomnia, anorexia,
abdominal pain, digestive
disturbances
Hookworm disease
Taeniasis
1 Although not pathogenic, they are frequently used as indicators.
                                                       31

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pathogens that may be present in sewage sludge and
pathogen and vector attraction reduction processes, see
other EPA documents (U.S. EPA,  1992a, 1994).

Following  land  application, bacterial pathogens gener-
ally die off to negligible numbers (99 percent die-off) in
12 days (Salmonella sp.) or 18 days (fecal coliform) at
a temperature  of 15°C (EPA, 1992b, based on EPA,
1987). Viruses commonly survive a maximum of 19 days
(surface application) at 15°C  (EPA, 1987; U.S. EPA,
1992b). Protozoa will survive for only a few days (Kowal,
1983). Viable helminth ova densities in sewage sludge
applied to the surface of grassed  plots are reduced by
more than 90  percent within 3  to 4  months; viable
helminth ova survive longer if sewage sludge is tilled into
the soil (Jakubowski, 1988). Generally,  none of these
microorganisms will leach through  the soil  system to
pollute the receiving ground waters (Edmonds, 1979),
but instead will  remain in the surface soils  for the dura-
tion of their survival period. Where  surface runoff occurs,
buffers should be used to filter out pathogens and pre-
vent entry into receiving water bodies.


4.8   Nutrients

Nutrients present in sewage sludge, such as nitrogen
(N), phosphorus (P), and potassium (K), among others,
are essential for plant growth and endow sewage sludge
with its fertilizing properties.  Nutrient levels are key de-
terminants of sewage sludge application rates. Exces-
sive nutrient levels due to high sludge  application rates
can  result in environmental contamination  of ground
water and surface water and should be avoided. The
Part 503 regulation requires that bulk sewage sludge be
applied to land  at the agronomic rate for nitrogen at the
application site.1

Table 4-4  shows levels of nutrients typically  present in
sewage sludge. Nutrient  levels,  however, particularly
nitrogen levels, can vary significantly, and thus analysis
should be conducted on the actual sewage sludge being
considered for land application. Typically, nutrient levels
in sewage sludge are considerably lower than those in
commercial fertilizers, especially K, which is usually less
than 0.5  percent in sewage sludge (Table 4-4).  Thus,
supplemental fertilization will usually be needed along
with sewage sludge  to  promote optimum vegetative
growth. More sewage sludge can be applied for addi-
tional nutrients  as long as the Part 503 CPLRs are not
exceeded, or the Part 503 pollutant concentration limits
are met (see Chapter 3). When the pollutant concentra-
tion limits are met, the application rate for the sewage
Table 4-4. Nutrient Levels Identified in Sewage Sludge
         (Sommers, 1977; Furr et al., 1976)a

                                 Percent13
Nutrient
Total N
NHJ-N
NOg-N
P
K
Na
Ca
Fe
Number of
Samples
191
103
43
189
192
176
193
165
Range
<0.1-17.6
5x10'4-6.76
2x10'4-0.49
<0. 1-14.3
0.02-2.64
0.01-3.07
0.1-25.0
<0.1-15.3
Median
3.30
0.09
0.01
2.30
0.30
0.24
3.9
1.1
Mean
3.90C
0.65
0.05
2.50
0.40
0.57
4.9
1.3
1 The agronomic rate is defined in Part 503 as the sewage sludge
 application rate designed to provide the amount of nitrogen needed
 by the crop or vegetation grown and to minimize the amount of
 nitrogen in the sewage sludge that passes below the root zone of
 the crop to the ground water.
3 Data are from numerous types of sludge in 15 states: Michigan,
 New Hampshire, New Jersey, Illinois, Minnesota, Ohio, California,
 Colorado, Georgia, Florida, New York, Pennsylvania, Texas, Wash-
 ington, and Wisconsin.
b Dry solids basis.
c It is assumed that 82 percent of the total N is organic N. So: organic
 N + NH4 + NO3 = TN, or: 3.2 + 0.65 + 0.05 = 3.90.

sludge is not impacted by the amount of each pollutant
in  the sewage sludge.
4.8.1  Nitrogen

Nitrogen  (N)  may be present  in sewage sludge in  an
inorganic  form, such as ammonium  (NH4) or nitrate
(NO3), or in an organic form.  The form in which N is
present in sewage sludge is a key factor in determining
how much N is available to plants, as well as the poten-
tial for N contamination of ground water. Generally,  in-
organic N as NO3 is the most water-soluble form of N,
and therefore is of the most concern for ground-water
contamination because of its high mobility in  most soil
types.  Inorganic N in the form  of NH4 can  readily vola-
tilize as ammonia (NH3) when sewage sludge is applied
to the soil surface rather than incorporated or injected,
and thus may not be available to plants. Organic N must
be decomposed by soil microorganisms, or mineralized
to inorganic  NH4  and NO3, before this form of N is
available for plants to use. Therefore, organic N can  be
considered a slow-release form of N.

The concentrations of organic  and inorganic N in sew-
age sludge are affected by the  type of sludge treatment
and handling processes used.  Most of the organic N in
sewage sludge is associated with the sludge solids, and
thus organic N levels are  not appreciably altered  by
sludge dewatering or drying procedures. In contrast, the
water-soluble inorganic forms of N and  their concentra-
tions will decrease dramatically during dewatering (e.g.,
drying  beds,  centrifuges, presses). Some  heat  or  air
drying  processes or lime treatment will  reduce NH4 be-
cause of NH3 volatilization, but will not affect NO3 levels.
                                                   32

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Aerobic conditions  facilitate  microbial conversion of
other N species to  the  mobile  NO3 form; conversely,
anaerobic conditions inhibit conversion of NH4 to NO3
by oxidation. Usually, over 90 percent of the inorganic N
in  sewage sludge will  be in  the form of NH4 unless
aerobic conditions have prevailed during  sludge treat-
ment. For most liquid sewage sludge collected from an
anaerobic digester, essentially all the inorganic N will be
present as NH4, constituting from 25 to 50 percent of the
total N. The NH4 concentration in the  liquid phase of
sludge is relatively constant at a specific treatment plant,
although treatment  process  such as  dewatering  can
substantially lower  the  NH4 content to less  than  10
percent of the total N.

Because the inorganic  N content of sewage sludge is
significantly influenced by sludge handling procedures, N
analysis should be conducted on the actual sewage sludge
that is land applied. The amount of inorganic N mineralized
in soils is affected by  the extent of sludge processing (e.g.,
digestion, composting) within the sewage treatment plant
and will generally be  less for well stabilized  sludge.

The organic N content of sewage sludge can range from
1 to 10 percent on a dry weight basis.  Organic N com-
pounds found in sludge are primarily amino acids, indi-
cating the  presence  of proteinaceous materials (Ryan et
al., 1973;  Sommers et al., 1972). After application to
soils, microbes in  the soil will decompose the organic N
compounds in sewage sludge,  resulting  in  release of
NH4, which can  then be  assimilated  by the crop or
vegetation being grown.

For a  further discussion of  nitrogen availability  once
sewage sludge  has  been land applied,  see Chapters 7,
8,  and 9.

 4.8.2  Phosphorous, Potassium, and Other
        Nutrients

Sewage sludge  contains varying concentrations of other
macro- and micronutrients required for plant growth. Some
sludge constituents,  such as  phosphorous (P), calcium
(Ca), magnesium  (Mg), and iron  (Fe), readily form insol-
uble compounds with sludge  solids  and thus  remain at
relatively high levels  in sewage sludge (Table 4-4).

Other sewage sludge constituents,  such as potassium
(K) and sodium (Na), are water-soluble  and are  dis-
charged with the treated  wastewater,  unless special
advanced  treatment processes  are used to remove
them. Of the water-soluble constituents that do remain
in the sludge, dewatering of sludge (e.g., by centrifuges
or presses) will further reduce  their concentrations in
sludge, while air or  heat drying  will result in increased
levels because these constituents are nonvolatile.

For a discussion  of the  influence of P,  K, and nutrient
levels on sewage sludge application rates, see Chap-
ters 7, 8 and 9.
4.9   Metals

Sewage sludge may contain varying amounts of metals;
at low concentrations in soil, some of these metals are
nutrients needed for plant growth and are often added to
inorganic commercial fertilizers.  But at high concentra-
tions, some metals may be toxic to humans, animals, and
plants. Based on an extensive risk assessment of metals
in sewage sludge, the Part 503 rule regulates 10 metals in
sewage sludge that is to be land applied, including:

• Arsenic

• Cadmium

• Chromium

• Copper

• Lead

• Mercury

• Molybdenum

• Nickel

• Selenium

• Zinc

The  Part 503 risk assessment found that other metals
do not pose potential  health or environmental risks at
land application sites. EPA's 1990  National Sewage
Sludge Survey (NSSS) analyzed samples of 412 pollut-
ants or analytes from 177 POTWs using at least secon-
dary treatment processes,  including  the  10  metals
regulated by Part 503  for land application, as shown in
Table 4-5. Chapter 3 discusses the  Part 503 pollutant
limits for these  10 metals.  Based on the NSSS survey,
EPA estimates that only approximately 2 percent (130
POTWs) of the 6,300 POTWs affected by Part 503
Table 4-5.
Metal
         Mean Concentrations of Metals in Sewage Sludge
         Compared to Part 503 Ceiling Concentration
         Limits (Adapted From U.S. EPA, 1990)
Mean Concentration
   (mg/kg, DW)
  Part 503 Pollutant
Ceiling Concentration
  Limits (mg/kg, DW)
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
9.9
6.94
119
741
134.4
5.2
9.2
42.7
5.2
1,202
75
85
3,000
4,300
840
57
75
420
100
7,500
                                                   33

-------
would not meet the regulation's "ceiling concentrations"
for metals, the minimal requirement for land application.
Metal concentrations in sewage sludge in large part
depend on the type and amount of industrial waste
discharged into the wastewater treatment system. Be-
cause metals are generally insoluble, they usually are
present at higher levels in sewage sludge than in waste-
water, and dewatering of sewage sludge has a minimal
impact on reducing metal concentrations in sewage
sludge destined for land application. Pretreatment of
industrial wastewater discharged to a sewerage system
has been effective in reducing the metals content of
sewage sludge generated at treatment works.

4.10 Organic Chemicals
Sewage sludge may also contain synthetic organic
chemicals from industrial wastes, household products,
and pesticides. Most sewage sludge contains low levels
of these chemicals and does not pose a significant
human health or environmental threat. Part 503 does not
regulate organic chemicals in sewage sludge because
the organic chemicals of potential concern have been
banned or restricted for use in the United States; are no
longer manufactured in the United States; are present
at low levels in sewage sludge based on data from EPA's
1 990 NSSS; or because the limit for an organic pollutant
identified in the Part 503 risk assessment is not ex-
pected to be exceeded in sewage sludge that is used or
disposed (U.S. EPA, 1992b).

4.11 Hazardous Pollutants (If Any)

Sewage sludge is not included on a list of specific wastes
determined to be hazardous by EPA, nor does available
data suggest that sewage sludge is likely to exhibit char-
acteristics of a hazardous waste, which include ignitability,
corrosivity, reactivity, ortoxicity. The non-hazardous nature
of sewage sludge, however, cannot be assumed.
Although sewage sludge conceivably could exhibit the
characteristics of ignitability, corrosivity, or reactivity, most
concerns about sewage sludge have focused on toxicity.
Few, if any, sewage sludges will exhibit the toxicity char-
acteristic (55 FR 11838). If, however, factors are present
indicating a possible toxicity problem (e.g., the treatment
works receives significant loadings of pollutants covered
by the test for toxicity) and the treatment works does not
have current data showing that the sludge is not hazard-
ous, it is advisable for the treatment works to test the
sewage sludge for toxicity (U.S. EPA, 1990).

The test for toxicity is the Toxicity Characteristic Leach-
ing Procedure (TCLP). This test can be used for both
sewage sludge and domestic septage. Forthe TCLP
test, concentrations of pollutants in a TCLP sewage
sludge extract are compared to regulatory levels for
tnyir.itv Tahlff 4-fi li<;t<; thp> tnyir.itv r.harar.tp>ri<;tir.
Table 4-6. Analytical Classification and
Constituent
Pesticides
Chlordane
Endrin
Heptachlor

Lindane
Methoxychlor
Toxaphene

Herbicides
2,4-D
2,4,5-TP Silvex
Volatiles
Benzene
Carbon tetrachloride
Chlorobenzene
Chloroform

1 ,2-Dichloroethane
1,1-Dichloroethylene
Methyl ethyl ketone
Tetrachloroethylene
Toluene
Trichloroethylene
Vinyl chloride

Semivolatiles
o-Cresol
m-Cresol

p-Cresol
1 ,2-Dichlorobenzene
1 ,4-Dichlorobenzene
2,4-Dinitrotoluene
Hexachlorobenzene
Hexachlorobutadiene
Hexachloroethane

Nitrobenzene
Pentachlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Metals
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver

Limits for TCLP Constituents
Limit, mg/L

0.03
0.02
Or\r\p
.UUo
0.4
10.0
0.5


10.0
1.0

0.5
0.5
100.0

6.0
0.5
0.7
200.0
0.7
1000.0
0.5
0.2


200.0
200.0

200.0
300.0
7.5
0 1
0.02
0.5

3.0
2.0
1.0
400.0
2.0

5.0
100.0
1.0
5.0
5.0
0.2
1.0
5.0

34

-------
pollutants and their regulatory levels. If the concen-
trations  of pollutants in the extract meet or exceed
these regulatory levels, the wastes are  classified as
hazardous.  If a sewage sludge or domestic septage
extract is deemed hazardous, land application would not
be allowed. Studies conducted by EPA's Office of Solid
Waste in 1985-86 found that none of the sewage sludge
samples tested  had TCLP extract concentrations that
exceeded the (then proposed) regulatory  levels. For
most pollutants, except metals, levels were non-detect-
able (U.S. EPA, 1993a).

4.12  Types of Sewage Sludge

The characteristics  of sewage sludge described above
will vary depending  on the type of sewage sludge gen-
erated, as discussed below.

4.12.1  Primary Sewage Sludge

Primary sewage sludge—sludge that is  the  result  of
primary wastewater treatment and has not undergone
any sludge treatment process—usually contains from 93
to 99.5 percent  water, as well as solids and dissolved
substances that were present in the wastewater or were
added during the wastewater treatment process (U.S.
EPA, 1984). Primary wastewater treatment removes the
solids (sludge) that settle out readily from  the wastewa-
ter. Usually the water content of this sludge can be easily
reduced by thickening or dewatering.

4.12.2  Secondary Sewage Sludge

Secondary wastewater treatment generally involves a
primary clarification  process followed by biological treat-
ment  and secondary clarification (U.S.  EPA,  1990).
Sewage sludge generated by secondary wastewater
treatment processes, such as activated biological sys-
tems and trickling filters, has a low solids content (0.5
percent to 2 percent) and is more difficult to thicken and
dewaterthan primary sewage sludge.

4.12.3   Tertiary Sewage Sludge

Tertiary sewage sludge is produced by advanced waste-
water treatment processes such as chemical precipita-
tion  and  filtration.  Chemicals  used   in  advanced
wastewater treatment processes, such  as aluminum,
iron, salts, lime, or  organic polymers, increase sludge
mass and usually sludge volume. Generally, if lime  or
polymers  are used, the thickening and dewatering char-
acteristics of sludge will improve, whereas if iron  or
aluminum salts are used, the dewatering and thickening
capacity of the sludge will usually be reduced.

4.12.4  Domestic Septage

Domestic septage is considered sewage  sludge by the
Part 503  regulation and is defined and  discussed  in
Table 4-7.  Chemical and Physical Characteristics of
         Domestic Septage (U.S. EPA, 1993b)
Parameter
Concentration, mg/kg
 (dry weight basis)
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
Nitrogen as N
Phosphorus as P
PH
Grease
Biochemical oxygen demand (BOD5)
Total solids (as normally spread)
4
3
14
140
35
0.15
-
15
2
290
2%
<1%
6-7
6-12%
6,480 mg/L
3.4%
Chapter 11. Table 4-7 shows some of the characteristics
of domestic septage. Domestic septage may foam and
generally has a strong odor (U.S. EPA, 1978). Settling
properties  are highly variable. Some domestic septage
settles  readily to about 20 to  50 percent of its original
volume, while others show little settling (U.S. EPA, 1979).

4.13 Effects of Wastewater and Sludge
      Treatment Processes on Sewage
      Sludge Characteristics

The effects of wastewater and sludge treatment proc-
esses on  sewage sludge characteristics have been
discussed above as  they pertain to specific sludge
parameters. This section focuses on the broader ef-
fects of treatment on sewage sludge characteristics,
highlighting the variable nature of treated sludge and
thus the need for site-specific sludge characterization.
Table 4-1  lists the various types of treatment proc-
esses, a number of which can be used to meet the
Part 503 pathogen or vector attraction reduction re-
quirements (see Chapters). Table 4-8 shows nutrient
levels found in sewage sludge subjected to different
treatment  processes. EPA's Process Design Manual
for Sludge Treatment and Disposal (U.S. EPA, 1979)
provides further information  on  sludge treatment
technologies.

Sewage sludge is virtually always treated by a stabiliza-
tion process prior to land application. Stabilization re-
duces the volume of  raw sludge by 25 to  40 percent
because much of the volatile  solids are degraded  to
                                                 35

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Table 4-8.  Nutrient Levels in Sewage Sludge From Different Treatment Processes (Sommers, 1977)a
Nutrient
Organic C (%)



Total N (%)



NHJ-N (mg/kg)



NOg-N (mg/kg)



Total P (%)



K(%)



Na (%)



Ca (%)



Sludge
Treatment
Process13
Anaerobic
Aerobic
Other
All
Anaerobic
Aerobic
Other
All
Anaerobic
Aerobic
Other
All
Anaerobic
Aerobic
Other
All
Anaerobic
Aerobic
Other
All
Anaerobic
Aerobic
Other
All
Anaerobic
Aerobic
Other
All
Anaerobic
Aerobic
Other
All
No. of
Samples
31
10
60
101
85
38
68
191
67
33
3
103
35
8
3
45
86
38
65
189
86
37
69
192
73
36
67
176
87
37
69
193
Range
18-39
27-37
6.5-48
6.5-48
0.5-17.6
0.5-7.6
<0. 1-10.0
<0. 1-17.6
120-67,600
30-11,300
5-12,500
5-67,600
2-4,900
7-830
—
2-4,900
0.5-14.3
1.1-5.5
<0. 1-3.3
<0. 1-14.3
0.02-2.64
0.08-1.10
0.02-0.87
0.02-2.64
0.01-2.19
0.03-3.07
0.01-0.96
0.01-3.07
1 .9-20.0
0.6-13.5
0.12-25.0
0.1-25.0
Median
26.8
29.5
32.5
30.4
4.2
4.8
1.8
3.3
1,600
400
80
920
79
180
—
149
3.0
2.7
1.0
2.3
0.30
0.39
0.17
0.30
0.73
0.77
0.11
0.24
4.9
3.0
3.4
3.9
Mean
27.6
31.7
32.6
31.0
5.0
4.9
1.9
3.9
9,400
950
4,200
6,540
520
300
780
490
3.3
2.9
1.3
2.5
0.52
0.46
0.20
0.40
0.70
1.11
0.13
0.57
5.8
3.3
4.6
4.9
1 Concentrations and percent composition are on a dried solids basis.
' "Other" includes lagooned, primary, tertiary, and unspecified sludges. "AH" signifies data for all types of sludges.
carbon dioxide, methane,  or other end products. This
decomposition of the organic matter in the sludge and
the subsequent release  of carbon dioxide,  ammo-
nium, hydrogen sulfide, and phosphate result in lower
levels of organic carbon (C), nitrogen (N), sulfur (S),
and  phosphorous  in the  stabilized sludge than was
present in the  raw sludge entering the stabilization
unit. Stabilization processes include aerobic and an-
aerobic digestion and composting, among others. The
actual  amounts of stabilized sludge produced in a
treatment works depends on operational parameters
(e.g, temperature, mixing, detention time) of the sta-
bilization process used.

Composting of sewage sludge results  in further de-
creases in the organic constituents.  If  the  sludge is
mixed with a bulking agent (e.g., wood chips) during com-
posting to facilitate aeration and rapid stabilization, some
of the bulking agent will remain in the compost (even
if screened), resulting in dilution of sludge components
(e.g., nutrients, metals). The extensive biological activity
that  occurs during  composting results  in further de-
creases in the organic N, C, and S content of the sludge.
In general, the organic N content of sludge decreases
in the following order: raw, primary or waste activated,
digested, and composted.

Wastewater and sewage sludge treatment processes
often involve the addition of ferric chloride, alum, lime,
or polymers. The concentration of these added ele-
ments  increase their  concentration in  the resultant
sludge. In  addition,  the  added compound can  have
other indirect effects on sludge composition. For exam-
ple, alum  precipitates as aluminum hydroxides, which
can subsequently adsorb phosphorus and coprecipitate
with  trace  metals  such as  cadmium.  Lime (calcium
oxide or hydroxide) used as a sludge stabilization agent
will ultimately precipitate in sludge  as calcium carbon-
ate, which also can retain phosphorus and metals. Lime
addition also may result in losses of ammonia through
volatilization.
                                                   36

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4.14  Effects of Pretreatment and
       Pollution Prevention  Programs on
       Sewage Sludge Characteristics

EPA first  established  pretreatment requirements  (40
CFR Part 403) in 1978. Pretreatment programs require
industries to limit the concentrations of certain pollutants
in wastewater discharged to a treatment works, includ-
ing heavy  metals and organic chemicals.

In addition to pretreatment programs, pollution preven-
tion programs designed to reduce or eliminate  pollution
are often developed as a joint effort by industry and
government and are  undertaken voluntarily  by  a
company. The quality of sewage sludge has continu-
ally improved  over  the years, and  many regulators,
researchers, and  treatment works  managers  believe
that pretreatment and  pollution  prevention programs
have been significant factors in  achieving this improve-
ment.  For example,  levels of cadmium, chromium, and
lead have decreased since the 1970s, as shown by data
from EPA's 1982 "40 City Study" (U.S. EPA, 1982) and
1990 NSSS (Shimp et al., 1994).

4.15  References

When  an NTIS number is cited in  a reference,  that
document is available from:
    National Technical Information Service
    5285 Port Royal Road
    Springfield, VA22161
    703-487-4650
Edmonds, R.  1979. Microbiological characteristics  of dewatered
   sludge following application to forest soils and clearcut areas. In:
   Sopper, W, and S. Kerr, eds. Application of municipal sewage
   effluent and biosolids on forest  and  disturbed land.  University
   Park, PA: Pennsylvania State University  Press.
Furr, A., A. Lawrence, S. long, M. Grandolfo, R. Hofstader, C. Bache,
   W. Gutenmann, and D. Lisk. 1976. Multi-element and chlorinated
   hydrocarbon analysis of municipal sewages  of American cities.
   Environ. Sci. Technol. 10:683-687.
Jakubowski, W. 1988. Ascaris ova survival in land application condi-
   tions. EPA Administrator's Item  Deliverable No. 2799 (May 1988).
Kowal, N. 1983. An overview of public health effects. In: Page, A., T.
   Gleason, III, J. Smith, Jr., I. Iskandar, and L. Sommers, eds. Proceed-
   ings of the 1983 Workshop on Utilization of Municipal Wastewater and
   Sludge on Land.  Riverside, CA: University of California, pp. 329-394.
Ryan, J., D. Keeney, and L. Walsh. 1973. Nitrogen transformations
   and availability of an anaerobically digested sewage sludge in soil.
   J. Environ. Quality 2:489-492.

Sagik, B., B. Moore, and C. Forber. 1979. Public health aspects related
   to the land application of municipal sewage effluents and sludges.
   In: Sopper, WE., and S.M. Kerr, eds. Utilization of municipal sewage
   effluent and sludge on forest and disturbed land. University Park,
   PA: Pennsylvania State University Press, pp. 241-263.

Shimp, G., K. Hunt,  S. McMillian, and G. Hunter. 1994.  Pretreatment
   raises biosolids quality. Environ.  Protection 5(6).

Sommers, L. 1977. Chemical composition of sewage  sludges and
   analysis of  their potential use as fertilizers. J.  Environ. Quality
   6:225-239.

Sommers, L., D. Nelson, J. Yahner, and J. Mannering. 1972. Chemi-
   cal  composition  of sewage sludge  from selected Indiana cities.
   Oroc. Indiana Acad. Sci. 82:424-432.

U.S. EPA. 1994. A plain English guide to the EPA 503 biosolids rule.
   EPA/832/R-93/003 (June). Washington, DC.

U.S. EPA Regions VIII and X. 1993a.  Biosolids management handbook
   for small to medium size POTWs. Denver, CO, and Seattle, WA.

U.S. EPA. 1993b. Domestic septage  regulatory guidance. EPA/832/B-
   92/005. Washington, DC.

U.S. EPA. 1992a. Control of pathogens and vector attraction in sew-
   age sludge. EPA/625/R-92/013. Cincinnati, OH.

U.S. EPA. 1992b. Technical support document for land application of
   sewage sludge, Vol. I. EPA/822/R-93900/9 (NTIS PB93110583).
   Washington, DC.

U.S. EPA. 1992c. Technical support document for reduction of patho-
   gens and vector attraction in sewage sludge. NTIS PB93110609.
   Washington, DC.

U.S. EPA. 1990. National Sewage Sludge Survey: Availability of in-
   formation and data, and anticipated impacts on proposed regula-
   tions. Fed. Reg.  55(218).

U.S. EPA.  1987. Survival  and transport of pathogens in  sludge-
   amended soil: A critical literature review. EPA/600/2-87/028. Cin-
   cinnati, OH.

U.S. EPA. 1984. Use and disposal of municipal wastewater sludge.
   EPA/625/10-84/003. Cincinnati, OH.

U.S. EPA. 1982. Fate of priority pollutants in publicly owned treatment
   works. EPA/440/1-82/303. Washington, DC.

U.S. EPA. 1979. Process design manual for sludge treatment and
   disposal. EPA/625/1-79/011. Cincinnati, OH.

U.S. EPA. 1978. Treatment and  disposal of septic tank sludges: A
   status report. Distributed at the Seminar on Small Wastewater
   Facilities. Cincinnati, OH.
                                                         37

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                                             Chapter 5
                            Site Evaluation and Selection Process
5.1   General

The process of planning a sewage sludge land applica-
tion project begins with the collection and assessment
of basic data on sludge characteristics. The sludge char-
acteristics in  conjunction  with  estimated  application
rates can then be compared to applicable federal, state,
and local regulations for an  initial assessment of sewage
sludge suitability for any of the land application practices
discussed in Chapter 2. The public's perception and
acceptance of such a proposed project, as well as land
availability, transportation  modes, and climatic condi-
tions, must all be considered and evaluated to determine
the feasibility of the proposed program.

The careful identification, evaluation, and ultimate selec-
tion of land application sites can prevent future environ-
mental  problems,  reduce monitoring  requirements,
minimize overall program costs, and moderate or elimi-
nate adverse public reaction. Poor site selection and
management practices in the past have resulted in en-
vironmental problems and public resistance.

Section 5.2 gives an overview of key requirements in the
Part 503 regulation  that affect site selection for land
application of sewage sludge. Figure 5-1  provides an
overview of a six-step process for identifying the best
sewage sludge land application  practice and the best
site(s) for land application  of sewage sludge. Sections
5.4 though 5.8 describe  each of the six steps in more
detail, and Section 5.9 provides an example of the site
selection procedures that  can be used for  a  typical
medium-sized community.


5.2   Part 503 Requirements

The Part 503 rule contains  several provisions that must
be considered during site selection for land application
of sewage sludge.  These provisions are discussed
briefly below and are explained  further in Chapter 3.
Some state and local governments have developed ad-
ditional or more  stringent  regulations; therefore, it is
important to check with state and local regulatory and
permitting agencies  where the proposed project is lo-
cated  to determine what requirements apply.
5.2.1  Protection of Surface Water and
       Wetlands

Part 503 specifies that sewage sludge cannot be applied
to flooded, frozen, or snow-covered agricultural land,
forests, public contact sites, or reclamation sites in such
a way that it enters  a wetland or other waters of the
United States, except as provided in a Section 402
(NPDES)  or Section 404 (dredge and fill) permit. In
addition, sewage sludge cannot be applied to agricul-
tural land, forests, or reclamation sites that are 10 me-
ters or less from waters of the United States,  unless
otherwise  specified by the permitting authority.

Other federal regulations also may  apply  to sewage
sludge application in wetlands. These  include:

• Sections 401, 402, and 404 of the Clean Water Act

• The Rivers and Harbors Act of 1989

• Executive Order 11990, Protection of Wetlands

• The National Environmental Policy Act

• The Migratory Bird Conservation Act

• The Fish and Wildlife Coordination Act

• The Coastal Zone  Management Act

• The Wild and Scenic Rivers Act

• The National Historic Preservation Act

Additional published information that may be useful in-
cludes USGS topographic maps, National Wetland In-
ventory  maps, Soil Conservation Service  (SCS) soil
maps, and wetland  inventory maps prepared  locally.
Some of the local U.S. Army Corps of Engineers  District
Offices can provide  a wetland delineation  to indicate
whether all or some portion of a potential or actual land
application site is in a wetland. The state agency regu-
lating activities  in wetlands should also be asked to
inspect the area in question. The definition of a wetland
and the regulatory requirements for activities in wet-
lands may be different at the state level.
                                                  39

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                  Determine Sewage Sludge Characteristics (Chemical,
                  Biological, and Physical, Chapter 4)
                  Preliminary Planning (Section 5.4)
                                            Review Applicable Federal, State, and Local
                                            Regulations and Guidelines for Land Application of
                                            Sewage Sludge (Section 5.4.1)
                                            Public Participation (Section 5.4.2)
                                            Estimate Land Area Required for Sewage Sludge
                                            Application, and Availability of Land Area Neccessary
                                            (Section 5.4.3)
                                            Assess Sewage Sludge Transport Modes and Their
                                            Feasibility (Section 5.4.4)
                   Phase I Site Evaluation and Site Screening (Section 5.5)   I
                                             Existing Information Sources (Section 5.5.1)
                                            Land Use (Section 5.5.2)
                                             Site Physical Characteristics (Section 5.5.3)
                                             Site Screening (Section 5.5.4)
                   Phase II Site Evaluation (Section 5.6 and Chapter 6)
                   Selection of Land Application Practice (Section 5.7)
                   Final Site Selection (Section 5.8)

Figure 5-1.  Simplified planning steps for a sewage sludge land application system.
5.2.2  Protection of Threatened and
        Endangered Species

Under Part 503, sewage sludge may not be applied to
land  if  it  is likely to adversely affect  a threatened  or
endangered species listed under Section 4 of the En-
dangered Species Act or the designated critical habitat
of such a species.  The Threatened and Endangered
Species List can be obtained from the U.S. Fish and
Wildlife Service's (FWS's) Publications Office in Wash-
ington,  DC. Critical habitat is defined as any place where
a threatened  or endangered species  lives and grows
during any stage of its life cycle.

Any direct or  indirect action (or the result of any direct
or indirect action) in a critical habitat that diminishes the
likelihood of survival and recovery of a listed species is
considered destruction or adverse modification of a criti-
cal habitat. Individuals may contact the Endangered Spe-
cies Protection Program in Washington, DC. or Fish and
Wildlife Service Field Offices for more information about
threatened and endangered species considerations in
their area. State departments governing fish and game
also should be contacted for specific state requirements.

5.2.3   Site Restrictions

Restrictions for the harvesting of crops and turf, grazing
of animals, and public access (see Chapters) also must
be met when sewage  sludge that  meets the Part 503
Class B pathogen requirements is land applied.
                                                      40

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5.3   Planning and Selection Process

As shown in Figure 5-1, this manual suggests a phased,
six-step planning and site selection approach.

5.4   Preliminary Planning

Careful  preliminary planning will help minimize delays
and expenses later on in the process by identifying legal
constraints (Section 5.4.1) and obtaining public  input
early in  the process (Section 5.4.2). A preliminary esti-
mate of land area requirements for different land appli-
cation  practices  (Section 5.4.3)  and  a  preliminary
identification of feasible  sewage sludge transportation
options  (Section 5.4.4)  helps  focus the Phase I site
evaluation and site screening process (Section 5.5). The
transportation assessment is especially important for
defining the geographic  search area for potential land
application sites.

5.4.1   Institutional and Regulatory Framework

All current federal, state, county, and municipal regu-
lations and guidelines should be reviewed during the
preliminary planning process. Depending on local pro-
cedure,  permits may be required from both state and
local regulatory agencies. Figure 5-2 shows the agen-
cies that have jurisdiction over land application of sew-
age sludge. Federal requirements under the Part 503
rule are described in detail in Chapter 3 of this manual.

5.4.2   Public Participation

Public participation is critical  during the early stages of
planning a land application project.  Most involvement
should come at the beginning of the planning process
when public input has the greatest potential to shape the
final  plan. This  early involvement  helps determine the
limits to public and political acceptability of the project.
During this phase, the public plays a constructive, as
opposed to a reactive, role in decision-making.

Site selection generally involves a preliminary screening
of numerous potential sites after which several sites are
selected for more detailed investigation. These selected
sites should be subjected to intense public scrutiny. It is
at this point that public participation can play a particu-
larly  formative  role in determining the final site and
design and operation procedures.

Most  public interest and involvement—including the
most vocal and organized protests—occur during the
site selection stage. Therefore, the major thrust of the
public participation program should come during this
stage, with a particular emphasis on two-way communi-
cation using such avenues as public meetings, work-
shops, and radio talk shows.
Chapter 12  provides a detailed discussion  of how to
design and implement a public participation program for
a land application project.

5.4.3  Preliminary Land A rea Requirements

A precise estimate of the land area required for sewage
sludge application should be based on design calcula-
tions  provided in Chapters 7, 8,  and 9  for the land
application practice  under consideration. However, for
preliminary planning, a rough estimate of the land appli-
cation area which might be necessary can be obtained
from Table 5-1. (Note that different practices may not
necessarily involve repeated annual applications.)

As an example, assume that the project is intended to
land apply 1,000 t  (1,100 T),  dry weight, of sewage
sludge annually. Using the typical rates shown  in Ta-
ble 5-1, a very rough estimate of the area required
for agricultural land application would be 90 ha (220
ac), plus  additional area required, if any, for buff-
er zones, sludge storage, etc. For  a one-time  appli-
cation of 1,0001 of sewage sludge  at a land reclamation
site, the typical values shown in Table 5-1  indicate that
9 ha (22 ac)  would be required.

5.4.4  Sewage Sludge Transport A ssessment

Transport  can be a major cost of a land application
project, and  requires a thorough analysis. This section
is intended only to provide a brief summary of the alter-
natives that  may be considered during the preliminary
planning phase.

Sewage sludge can  be transported by truck, pipeline, or
rail. In certain instances,  combined transport methods
(e.g.,  pipeline-truck) are  also used. The  choice of a
transportation method depends on the type of land se-
lected, the volume and solids content of the sewage sludge,
and the distance to and number of destination points.

The first consideration is the  nature  of  the  sewage
sludge itself. As shown in Table 5-2,  sewage sludge is
classified for handling/transport purposes as either liq-
uid, sludge  cake, or dried,  depending on its solids
content. Only liquid  sludge can be pumped and trans-
ported by pipeline.  Pipeline transport can be  cost
effective for long-distance pumping of liquid sludge
(usually less than 8 percent solids) but has been used
for sludge up to 20  percent solids over very short dis-
tances. If liquid sludge is transported by truck or rail,
closed vessels must be  used, e.g., tank truck, rail-
road tank cars, etc. Sludge cake can  be  transported
in  watertight boxes, and dry sludge can  be trans-
ported in open boxes (e.g.,  dump trucks).

Trucks and  pipelines are the  most  common form of
transport.  Rail transport  also  is  used  in  the  United
States. An example  is rail  shipment of sludge from New
York to Texas.
                                                  41

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                                Agencies With Jurisdiction Over Land Application
              State
                             U.S. Environmental
                             Protection Agency

                             Office of Surface
                             Mining Reclamation
                             and Enforcement
                             (reclamation sites)
              Federal f	u.S. Fish and
                             Wildlife Service
                             (protection of
                             threatened and
                             endangered species)

                            XU.S. Army Corps of
                             Engineers (dredge-
                             and-fill permits)
                                                     National
                                      'Regional
                                                     Office of Science and Technology
                                                     (Part 503 regulation)

                                                     .Office of Wastewater Management
                                                     (permitting, state sludge programs,
                                                     beneficial use)

                                                      ffice of Enforcement and Compliance

                                                     ^Office of Solid Waste (sewage sludge
                                                     generated at industrial facilities)
 onstruction Grants
Review

 olid Waste Program
Review

Permitting and
Enforcement (Part 503
permits)
                                Wastewater Programs

                                Environmental Quality (surface water,
                                ground water, soils, etc).

                                Solid Waste Management

                                Public Health

                                Agriculture

                                Transportation
                                               Land Use

                                              • Conservation/ Environmental Quality

                                              • Public Health

                                              • Solid Waste Management

Figure 5-2.  Institutional framework (adapted from Deese et al., 1980).
Local
(Receiving
Community)
Truck transport allows greater flexibility than any other
transport method. Destinations can be  changed with
little advance notice, and the sludge can be distributed
to many different destinations. If trucks must be routed
along residential  or secondary streets,  public  concern
about congestion and the risk of sludge  spills  must be
considered.  Most land  application  systems  use truck
transport, either alone or after sludge transport  by pipe-
line  or  rail to an intermediate storage  facility. Liquid
sludge of up to 10 percent solids concentration (depend-
ing on its viscosity) can be transported in tank trucks.
Dewatered sludge with a greater than 10 percent solids
concentration can usually be transported in open trucks
with watertight seals if precautions are taken to prevent
                                            spillage.  Dried  and  composted sludge  with approxi-
                                            mately 50 percent or greater solids concentration can be
                                            transported without watertight seals or splash  guards
                                            (U.S. EPA, 1984).

                                            The desirable limit for a truck haul distance is about 25
                                            to 40 km (15  to 25 mi)  one way.  For  low  cost land
                                            application of liquid sludge, the  land must generally be
                                            within about a  16-km  (10-mi) radius of the  treatment
                                            plant. Mechanically dewatered sludge can generally be
                                            economically transported to a site up to about 22 km (20 mi).
                                            Air-dried sludges, which have solids concentrations in ex-
                                            cess of 55 to 60  percent, can be economically transported
                                            a greater distance. In  evaluating transportation costs,
                                                       42

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Table 5-1.  Preliminary Estimates of Sewage Sludge Applications (Dry Weight) for Different Types of Land

                                                              Reported Range of
                                                              Application Rates
                                                                       Typical Rate
                                                            t/ha
                                                                           T/ac
                                                                                           t/ha
                                                                                                          T/aca
Land Type
Time Period of Application
Agricultural Land
Forest Land
Land Reclamation Site
Annual or twice annually
Annually, or at 3-5 year intervals
One time
2-70
1 0-220
7-450
1-30
4-100
3-200
10
18
112
5
8
50
at = metric tonnes
T = English tons (short)
Table 5-2.  Sewage Sludge Solids Content and Handling
          Characteristics
Sludge Type Solids Content (%) Transport Methods
Liquid
Sludge cake ("wet"
solids)
Dried
1 to 10 Gravity flow, pump,
pipeline, tank transport
10 to 30 Conveyor, auger, truck
transport (watertight
box)
50 to 95 Conveyor, bucket,
truck transport (box)
the cost of dewatering must be weighed against the cost
savings that can result from transporting a drier sludge
(U.S. EPA, 1984).
Tables 5-3  and 5-4 present some practical considera-
tions for hauling sludge. Table 5-5 provides a rating of
transport modes  in terms of reliability,  staffing  needs,
energy requirements, and costs. For a detailed discus-
sion of sludge transport, see Chapter 14.
                                   5.5   Phase I Site Evaluation and Site
                                         Screening

                                   A Phase I site evaluation uses the information obtained
                                   during preliminary planning, namely the estimate of pre-
                                   liminary land area requirements (Section 5.4.3) and the
                                   results of the transportation assessment (Section 5.4.4),
                                   to identify potential land application sites. Existing infor-
                                   mation sources (Section 5.5.1)  are used to identify mul-
                                   tiple  sites  considering  land  use  (Section 5.5.2) and
                                   physical characteristics (Section 5.5.3) within the area
                                   that sewage sludge  can feasibly  be transported. Site
                                   screening allows elimination of unsuitable  areas due to
                                   physical,  environmental,  social,  or  political reasons
                                   (Section 5.5.4), and identification of sites for more detailed
                                   Phase II site evaluation (Section 5.6 and Chapters).

                                   5.5.1   Existing information Sources

                                   Sources of information on land characteristics, cropping
                                   patterns, and other  relevant data in  the geographic
                                   search area include:

                                   • U.S. Department of Agriculture - Consolidated Farm
                                     Service  Agency, Natural  Resources  Conservation
Table 5-3.  Transport Modes for Sewage Sludge

Sewage Sludge Type                Transportation Considerations
Liquid Sludge

Vehicles:
  Tank Truck
  Farm Tank Wagon and Tractor

Pipeline


Rail Tank Car

Semisolid or Dried Sludge

Truck


Farm Manure Spreader

Rail Hopper Car
          Capacity - up to maximum load allowed on road, usually 6,600 gal maximum. Can have gravity
          or pressurized discharge. Field trafficability can be improved by using flotation tires at the cost of
          rapid tire wear on highways.

          Capacity - 800 to 3,000 gal. Principal use would be for field application.

          Need minimum velocity of 1 fps to keep solids in suspension; friction decreases as pipe diameter
          increases (to the fifth power); buried pipeline suitable for year-round use. High capital costs.

          100-wet-ton (24,000-gal) capacity; suspended solids will settle while in transit.
          Commercial equipment available to unload and spread on ground; need to level sludge piles if
          dump truck is used. Spreading can be done by farm manure spreader and tractor.

          Appropriate for small systems where nearby farmlands are accessible by a manure spreader.

          May need special unloading site and equipment for field application, although in many cases can
          use conventional unloading equipment.
                                                       43

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Table 5-4. Auxiliary Facilities for Sewage Sludge Transport
(Gulp et al., 1980)
Transport Mode

Liquid

Loading storage

Loading equipment

Dispatch office

Dock and/or control
building

Railroad siding(s)

Unloading equipment
Unloading storage*
Dewatered
Loading storage
Loading equipment
Dispatch office

Dock and/or control
building
Railroad siding(s)

Unloading equipment
Unloading storage
* Storage required for
normal plant sludge
^ Not applicable.
Truck


No*

Yes

Yes

NA


NA

Yes
No

Yes*
Yes
Yes

NA

NA

Yes
No
one or two
storage.
Railroad


Yes

Yes

Yes

NA


Yes

Yes
Yes

Yes
Yes
Yes

NA

Yes

Yes
No
truckloads is
Barge


Yes

Yes

Yes

Yes


NA

Yes
Yes

NA
NA
NA

NA

NA

NA
NA
Pipeline


Yes

Yes

NA1"

Yes


NA

NA
Yes

NA
NA
NA

NA

NA

NA
NA
small compared with
Table 5-5. Evaluation of Sewage Sludge Transport Modes
(Gulp et al., 1980)
Transport Mode Alternatives
Characteristics Truck Pipeline Railroad
Reliability and 131
Complexity1

Staffing Skills2 1 3 2

Staff Attention (Time)3 3 2 1

Applicability and 1 3 2
Flexibility4

Energy Used5 862

Costs
Capital Investment Low High —
Operation, Fairly High Low —
Maintenance, and Labor
Overall6 — — Generally
High7
1 1 = most reliable, least complex; 2 = intermediate; 3 = least
reliable, most complex.
2 1 = least skills; 2 = intermediate; 3 = highest skills.
3 Attention time increases with magnitude of number.
4 1 = wide applicability (all types of sludge); 3 = limited applicability,
relatively flexible.
5 1 = lowest; 8 = highest.
6 Overall costs are a function of sludge quantities and properties
(percent solids), distance transported, and need for special
storage loading and unloading equipment.
7 Rail costs would generally be in the form of freight charges; costs
could be lower for large volumes of sludge, or if long-distance rail
is less expensive than truck transport.
  Storage assumed to be a part of another unit process.
** Elevated storage for ease of gravity transfer to trucks.
  Service, Forest Service,  and Cooperative State Re-
  search Education and Extension Service.

• U.S. Geological Survey.

• U.S. EPA.

• U.S. Army Corps of Engineers.

• Private photogrammetry and mapping companies.

• State agricultural  mining  and geologic agencies.

• State water resource agencies.

• State universities and local colleges.

• Local planning and health departments.

• Local water conservation districts.

• Ground water users  (municipalities, water compa-
  nies, individuals, etc.).

• State land grant universities and water resource centers.

Section 5.5.3.5 identifies major sources for climatic data.
5.5.2  Land Use and A vail ability

Prevailing or projected land use often exerts a signifi-
cant influence on site selection, as well as  on accep-
tance of a particular sewage sludge land application
practice.  It is necessary to  determine both current and
future land use in assessing the land area  potentially
suitable and/or available for sewage sludge application.
Important considerations include zoning  compliance,
aesthetics, and site acquisition.

5.5.2.1   Current Land Use

Current land use patterns will help identify areas where
land application of sewage sludge may be acceptable.
The local SCS and Agricultural Extension Service repre-
sentatives have knowledge of local farming, forestry, min-
ing, and other land use practices. The SCS will, in many
cases, have a comprehensive county soil survey with
aerial photo maps showing  the land area.

• Agricultural Lands.  To a great  extent,  prevailing
  farming practices dictate the acceptability of agricul-
  tural land application. Small land holdings in a non-
  agricultural community may limit application to this
  type of land. An area devoted  almost exclusively to
  production of human food crops restricts the periods
  when sewage sludge can be applied to land. Areas
                                                   44

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  with a mixture of row crops, small grains, hay crops, and
  pastures may allow sewage sludge application through-
  out much of the year, depending on farming cycles.

• Forest Lands. A consideration in sewage sludge ap-
  plication to forest lands is the potential need to control
  public access for a period of time after sludge appli-
  cation. Therefore, the most desirable sites are often
  those owned  by or leased to commercial growers,
  which already control public access. Publicly owned
  forest land has been used for sewage sludge appli-
  cation, but may require interagency negotiations and
  greater public education efforts than the use of pri-
  vately owned land.

• Reclamation  Sites. Potential reclamation sites are
  relatively easy to identify in a particular local  area.
  Sewage sludge land application design is influenced
  by the  potential future use of the  reclaimed land (i.e.,
  agriculture, silviculture, parks, greenbelts, etc.). The
  application of sewage sludge is often a one-time op-
  eration at reclamation sites  rather than a repetitive
  series of applications on the same site. It is therefore
  necessary that (1) the mining or other  operations will
  continue to generate disturbed land to which sludge
  can  be applied, or (2)  the  reclamation area  is  of
  sufficient size to allow a continuing sludge application
  program over the design  life  of the project. State and
  federal guidelines may dictate the criteria for sludge
  applications and subsequent  management.

• Public Contact Sites. Public contact sites such as
  parks,  golf courses, and cemeteries are good candi-
  dates for land application of sewage sludge. Because
  municipalities  often own these sites, a land applica-
  tion program may be easier to arrange at these sites
  than at privately owned sites. Bagged sewage sludge
  is  often used  at public contact sites having  a small
  land area.  Regulatory requirements and other con-
  siderations for the  use  of sewage sludge at public
  contact sites are explained in Chapter 10.

• Lawns and Home Gardens. Bagged sewage sludge
  can be used like other fertilizers for lawns and home
  gardens. Regulatory and other considerations for use
  of sewage sludge  on lawns and home gardens are
  discussed in  Chapter 10.

5.5.2.2   Future Land Use

Projected land use plans,  where they exist, should be
included when considering  sewage sludge land applica-
tion. Regional  planners and   planning  commissions
should be consulted  to determine the projected use  of
potential  land application sites and adjacent properties.
If the site is located in or near a densely populated area,
extensive control measures may be needed  to  over-
come concerns and minimize potential aesthetic prob-
lems  that may detract from  the  value  of adjacent
properties.  Master  plans  for  existing  communities
should be examined. The rate of industrial and/or mu-
nicipal expansion relative to prospective sites can sig-
nificantly affect long-term suitability.

5.5.2.3   Zoning Compliance

Zoning and  land use planning are closely related, and
zoning ordinances generally reflect future land use plan-
ning. Applicable  zoning  laws, if any, which  may affect
potential land application sites should be reviewed con-
currently with land use evaluations. Since it is unusual
that a  community will have  a specific area zoned for
sludge/waste storage, project proponents may need to
seek a zoning change for separate sewage sludge stor-
age facilities.

5.5.2.4   Aesthetics

Selection of a  land  application site  and/or sewage
sludge land application practice can be affected by com-
munity concern over aesthetics, such as noise, fugitive
dust,  and odors. In addition to application  site area
concerns, routes for sludge transport vehicles must be
carefully evaluated  to avoid  residential areas,  bridge
load limitations, etc. Disruption of the local scenic char-
acter and/or recreational activities, should they occur,
may  generate strong local opposition  to  a sewage
sludge management program. Every attempt must be
made to keep the application site  compatible with its
surroundings and, where possible, enhance the beauty
of the landscape. Buffer zones are usually required to
separate sewage sludge application sites from resi-
dences, water supplies, surface waters,  roads,  parks,
playgrounds, etc.

5.5.2.5   Access

The preliminary sewage  sludge transportation feasibility
assessment (Section 5.4.4) will  narrow the geographic
search area for potential sites by focusing attention on
areas that are adjacent  to or in the vicinity of existing
transportation corridors  (e.g., roads,  rail  lines) for the
selected sewage sludge transportation modes.  Areas
that are too  distant for economic transport, or to which
access is restricted for other reasons (such as physical
barriers), can be eliminated from further consideration.

5.5.2.6   Site Acquisition

Application of sewage sludge to agricultural land can
often be accomplished without direct purchase or lease
of the land.  Well-prepared educational and public par-
ticipation programs early in the planning stages often
identify numerous farmers willing to participate in a land
application program. This type of arrangement may be
more acceptable to the public in some cases than pur-
chasing land for  sewage sludge land application.
                                                   45

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Several different contractual arrangements  between
municipalities and landowners for agricultural land ap-
plication have been successfully employed, including:
• The  municipality transports and spreads the sludge
  at no expense to the landowner.
• The  municipality transports and spreads the sludge
  and pays the landowner for the use of his land.
• The  landowner pays a nominal fee for the sewage
  sludge  and  for  the municipality to transport  and
  spread the sludge. This is most common for agricul-
  tural sites where local demand for sewage sludge as
  a fertilizer or soil conditioner exists.
• The municipality hauls the sludge and the landowner
  spreads it.
• The landowner hauls and  spreads the sludge.
A written contract between the landowner and the sew-
age  sludge  preparer and/or applier is highly recom-
mended. In some instances, the preparer/applierwill be
the municipality; in  other cases, it will be  a private
preparer/applier who is transporting and spreading for
the municipality. The Part 503 rule contains require-
ments for both preparers and appliers (see Chapter 3).
The principal advantage of a written contract is to ensure
that  both  parties understand the agreement prior  to
applying the sewage sludge. Often, oral contracts are
entered with the best of intentions,  but the landowner
and preparer/applier  have differing notions of the rights
and obligations of each party. In some cases, the con-
tract may serve as evidence  in disputes concerning the
performance of either the preparer/applier or the land-
owner. Suggested provisions of contracts between the
applier and landowner are shown in Table 5-6.
The use of land without purchase or lease may also be
applicable for land application of sewage sludge to for-
ested lands  and reclamation  sites. Direct purchase  or
lease, however, may be necessary for large-scale sew-
age sludge management systems regardless of the type
of land at which sewage sludge is applied.  In these
instances, site acquisition represents a major cost in the
implementation of the land application program.

5.5.3  Physical Characteristics of Potential Sites
The physical characteristics of concern are:
• Topography
• Soil permeability, infiltration, and drainage  patterns
• Depth to ground water
• Proximity to  surface water
The  planner/designer should review federal  and state
regulations or guidelines that  place  limits  on  these
physical characteristics of application sites. Chapter 6
addresses site  physical characteristics in more detail.
This section focuses on information that can usually be
obtained from existing topographic and soil maps for the
purpose of identifying sites where more detailed inves-
tigations may be justified.

5.5.3.1   Topography

Topography  influences surface  and subsurface water
movement, which affects the amount of potential soil
erosion and surface water  runoff containing  applied
sewage sludge. These considerations have been fac-
tored into the pollutant limits established in the Part 503
regulation. Topography also can indicate the kinds of soil
to be found on a site.

Quadrangle maps published by the U.S. Geological Sur-
vey  may be useful during  preliminary  planning  and
screening to estimate slope, local depressions  or wet
areas,  rock  outcrops, regional drainage patterns, and
water table elevations. These maps, however, usually
are drawn to a scale that cannot be relied on for evalu-
ating small parcels  and do not  eliminate the  need for
field investigation of potential sewage sludge land appli-
cation sites. The use of regional and soil survey maps
can  help eliminate  potentially unsuitable areas. Table
5-7 summarizes important criteria; see Section 5.2.1 for
related Part 503 regulatory requirements.

Soils on ridge tops  and steep slopes are typically well
drained, well aerated, and usually shallow. But steep
slopes,  except  on very  permeable soils, increase the
possibility of surface runoff of sewage sludge. Soils on
concave land and broad flat lands frequently are poorly
drained and may be  waterlogged during part of the year.
Soils between  these two  extremes will usually have
intermediate properties with respect to  drainage  and
runoff.  Application to steep slopes (from 30 to over 50
percent) in forested  areas may be possible under spe-
cific conditions (e.g., properly buffered slopes with good
forest floor/understory  vegetation, depending on the
type of soil, vegetation, and sewage  sludge) if it can be
shown that the risk from runoff is low. Forest sites, which
generally have  a very permeable forest floor,  and new
technology  for  applying dewatered  sewage sludge  in
forests greatly  reduce the potential for overland flow.1

The steepness, length, and shape of slopes influence
the rate of runoff from a site. Rapid surface water runoff
accompanied by soil erosion  can erode sewage  sludge
soil  mixtures and transport  them to  surface waters.
Therefore, state regulations/guidelines often  stipulate
the maximum slopes allowable for sewage  sludge land
application  sites  under various conditions regarding
sludge physical characteristics,  application  techniques,
and  application rates.  Specific guidance  should  be
1 Henry, C. 1995. Personal communication, Dr. Charles Henry, Pack
 Forest Research Center, University of Washington, Eatonville, WA.
                                                   46

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Table 5-6.  Suggested Provisions of Contracts Between
          Sewage Sludge Preparer, Sludge Applier, and
          Private Landowners (Sagik et al., 1979)
Identification of the landowner, the preparer, and the applier
   spreading the sludge.

Location of land where application is to occur and boundaries of
   the application sites.

Entrance and exit points to application sites for use by spreading
   equipment.

Specification of the range of sludge quality permitted on the land.
   Parameters identified might include percent  of total solids;
   levels of trace elements and pathogens in the sludge, and
   vector attraction reduction, as regulated by Part 503; additional
   state and local parameters required. The contract would specify
   who is to pay for the analysis, and frequency of analysis.

Agreement on the timing of sludge application during the cropping
   season. Application rates and acceptable periods of application
   should be identified for growing crops, as well as periods when
   the soil is wet.

Agreements on the application rate (agronomic rate). This rate
   might vary through the year depending on the crop, the sludge
   analyses, and when and where application is occurring.

Restrictions on usage of land for growing root crops or fresh
   vegetables, or for grazing livestock.

Conditions under which either party may escape from provisions of
   the contract or be subject to indemnification or liability issues.
Table 5-7.  Potentially Unsuitable Areas for Sewage Sludge
          Application
Areas bordered by ponds, lakes, rivers, and streams without
   appropriate buffer areas.

Wetlands and marshes without a permit.

Steep areas with sharp relief.

Undesirable geology (karst, fractured bedrock) (if not covered by a
   sufficiently thick soil column).

Undesirable soil conditions (rocky, shallow).

Areas of historical or archeological significance.

Other environmentally sensitive areas such as floodplains or
   intermittent streams, ponds, etc., as specified in the Part 503
   regulation.
obtained  from appropriate regulatory agencies; for gen-
eral guidance, suggested limits are presented in Table
5-8.

5.5.3.2   Soils and Geology

Soil survey reports can be obtained  from  local  SCS
offices and are suitable for  preliminary planning. When
potential  sites are identified, field inspections and inves-
tigations  are  necessary to confirm expected conditions
(Section 5.4.2). The SCS mapping units cannot represent
areas smaller than 0.8 to 1.2 ha  (approximately 2 to 3
acres). Thus, there is  a possibility that small areas of
Table 5-8.  Recommended Slope Limitations for Land
          Application of Sewage Sludge

Slope       Comment

0-3%        Ideal; no concern for runoff or erosion of liquid or
            dewatered sludge.

3-6%        Acceptable for surface application of liquid or
            dewatered sludge; slight risk of erosion.

6-12%       Injection of liquid sludge required in most cases,
            except in closed drainage basin and/or areas with
            extensive runoff control.  Surface application of
            dewatered sludge is usually acceptable.

12-15%      No liquid sludge application without effective runoff
            control; surface application of dewatered sludge is
            acceptable, but immediate incorporation is
            recommended.

Over 15%    Slopes greater than 15% are  only suitable for sites
            with good permeability (e.g., forests), where the
            steep slope length is short (e.g., mine sites with a
            buffer zone downslope),  and/or the steep slope is a
            minor part of the total application area.
soils  with  significantly  different characteristics  may be
located within a mapping unit but not identified. SCS soil
surveys provide information on typical characteristics of
soil map units that are very  useful for identifying the
most favorable soils within a potential site and for com-
paring relative suitability of different possible sites. Sec-
tion 5.9.8 (Table 5-15) illustrates how relevant information
on soil types can be compiled.

The texture of the soil and parent geologic material is
one of the most important aspects of site selection
because it influences permeability, infiltration, and drain-
age.  It is  important  that a  qualified soil scientist  be
involved  in the assessment of soils at potential  land
application sites.

With  proper design and operation, sewage sludge can
be  successfully applied to virtually any soil. However,
highly permeable  soil (e.g., sand), highly impermeable
soil (e.g., clay;  although the addition of organic material
in sewage  sludge may help reduce impermeability), or
poorly drained soils may present special design require-
ments. Therefore, sites with such conditions should gen-
erally be given a lower priority during the preliminary site
selection process. Table 5-9 summarizes typical guide-
lines  for soil suitability. In some cases, the favorable
aspects (i.e., location,  municipal ownership,  etc.) may
outweigh the costs of mitigation measures.

Soil Permeability and Infiltration

Permeability  (a property determined by  soil  pore space,
size,  shape,  and  distribution)  refers  to the ease with
which water and air are transmitted through soil. Fine-
textured soils generally possess slow or very slow per-
meability, while the permeability of coarse-textured soils
ranges from moderately rapid to very rapid. A medium-
                                                         47

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Table 5-9.  Soil Limitations for Sewage Sludge Application to Agricultural Land at Nitrogen Fertilizer Rates in Wisconsin (Keeney
          et al., 1975)
                                                                    Degree of Soil Limitation
Soil Features Affecting Use
Available water capacity
Slight
                                                                    Moderate
                                                                                           Severe
Slope3
Depth to seasonal water table
Flooding and ponding
Depth to bedrock
Permeability of the most restricting layer
above a 1-m depth
Less than 6%
More than 1 .2 m
None
More than 1 .2 m
0.24 to 0.8 cm/hr
6 to 12%
0.6to 1.2 m
None
0.6 to 1.2 m
0.8 to 2.4 cm/hr
0.08 to 0.24 cm/hr
More than 12%
Less than 1 m
Occasional to frequentb
Less than 0.61 m
Less than 0.08 cm/hr
More than 2.4 cm/hr
                                              More than 2.4 cm
                                                                    1.2 to 2.4 cm
                                                                                           Less than 1.2 cm
3 Slope is an important factor in determining the runoff that is likely to occur. Most soils on 0 to 6% slopes will have slow to very slow runoff;
 soils on 6 to 12% slopes generally have medium runoff; and soils on steeper slopes generally have rapid to very rapid runoff.
b Land application may be difficult under extreme flooding or ponding conditions.
Metric conversions: 1 ft = 0.3048 m, 1 in =  2.54 cm.
textured soil, such as a loam or silt loam, tends to have
moderate to slow permeability.

Soil Drainage

Soils classified as (1)  very poorly drained, (2)  poorly
drained, or (3) somewhat poorly drained  by  the Soil
Conservation   Service  may  be  suitable  for  sewage
sludge  application if runoff control  is  provided. Soils
classified  as  (1)  moderately  well-drained,  (2)  well
drained, or (3) somewhat excessively drained  are gen-
erally suitable for sewage sludge application. Typically,
a well-drained  soil is at least moderately permeable.

5.5.3.3   Surface Hydrology, Including
         Floodplains and Wetlands

The number, size,  and nature of surface water bodies
on  or near a potential sewage  sludge land application
site are significant factors in site selection due to  poten-
tial contamination from site runoff and/or flood events.
Areas subject  to frequent flooding have severe  limita-
tions for sewage sludge application. Engineered flood
control  structures can be constructed to protect  a  land
application site against flooding, but such structures can
be  prohibitively expensive.

5.5.3.4   Ground Water

For preliminary screening of potential sites, it is recom-
mended that the following ground-water information for
the land application area be considered:

• Depth to  ground water (including historical highs and lows).

• An estimate of ground water flow patterns.

When a specific site or  sites  has  been  selected for
sewage sludge application, a detailed field investigation
may be necessary to determine the  above information.
During preliminary screening, however, published general
            resources may be located at local USGS or state water
            resource agencies.

            Generally, the greater the depth to the water table, the more
            desirable a site is for sewage sludge application.  Sewage
            sludge should not be placed where there is potential for
            direct contact with the ground-water table. The actual
            thickness of unconsolidated  material above a permanent
            water table constitutes the effective soil depth. The desired
            soil depth may vary according to sludge characteristics,
            soil texture, soil pH, method of sludge application, and
            sludge application rate.  Table 5-10 summarizes  recom-
            mended criteria for the various land application practices.

            The type and condition of consolidated material above the
            watertable is also of major importance forsites where high
            application  rates of sewage sludge are desirable.  Frac-
            tured rock may allow leachate to move rapidly. Unfractured
            bedrock at shallow depths will restrict water movement,
            with the potential for ground  water mounding, subsurface
            lateral flow, or poor  drainage. Limestone bedrock is of
            particular concern where sinkholes may exist. Sinkholes,
            like  fractured rock,  can accelerate  the  movement of
            leachate to ground water. Thus, potential sites with potable
            ground water in areas underlain by fractured bedrock, by

            Table 5-10.  Recommended Depth to Ground Water
            Type of Site      Drinking Water Aquifer3   Excluded Aquiferb
            Agricultural

            Forest

            Reclamation
1-2 m

2mc

1-2 m
0.5 m

0.7m

0.5 m
             States may have other depth-to-ground water requirements.
            b Clearances are to ensure trafficability of surface, not for ground
             water protection; excluded aquifers are not used as potable water
             supplies.
            c Seasonal (springtime) high water and/or perched water less than 1 m
             are not usually a concern.
            Metric conversion: 1 m = 3.28 ft.
                                                      48

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unfractured rock at shallow depths,  or with limestone
sinkholes should be avoided.
5.5.3.5   Climate


Analysis of climatological data is an important consid-
eration for the preliminary planning phase. Rainfall, tem-
perature,  evapotranspiration,   and  wind  may   be
important climatic factors affecting  land application of
sewage sludge, selection of land application practices,
site management, and costs. Table 5-11 highlights the
potential impacts of some climatic regions on the land
application of sewage sludge.

Meteorological data are available for most major cities
from three publications of the National  Oceanic and
Atmospheric Administration (NOAA):

• The Climatic Summary of the  United States.

• The Monthly Summary of Climatic Data, which pro-
  vides basic data, such  as total precipitation,  maxi-
  mum   and  minimum  temperatures,  and  relative
  humidity, for each day of the  month, and for every
  weatherstation in the area. Evaporation data are also
  given, where available.

• Local Climatological Data, which provides an  annual
  summary and comparative data for a relatively small
  number of major weather stations.

This information can be obtained by written request from
NOAA, 6010 Executive Boulevard, Rockville, Maryland
20852. Another excellent source is the National Climatic
Center in Asheville, North Carolina 28801. Weather data
may also  be  obtained from local airports, universities,
military  installations, agricultural and forestry extension
services and experiment stations, and agencies manag-
ing  large reservoirs.

Table 5-11.  Potential Impacts of Climatic Regions on Land
          Application of Sewage Sludge (Gulp et al.,  1980)
                          Climatic Region
Impact
               Warm/Arid
                            Warm/Humid  Cold/Humid
Operation Time
Operation Cost
Storage
Requirement
Salt Buildup
Potential
Leaching
Potential
Runoff Potential
Year-round
Lower
Less
High
Low
Low
Seasonal
Higher
More
Low
High
High
Seasonal
Higher
More
Moderate
Moderate
High
5.5.4   Site Screening

Site  screening  is an integral part of the Phase I  site
evaluation process. Initially, development of land area,
transportation  distance, topographic, soils, hydrologic
and  other site screening criteria helps focus efforts on
collecting relevant information. One practical screening
technique involves the  use of transparent (mylar) over-
lays  with concentric rings drawn around the wastewater
treatment facility. The distance represented by the initial
ring  will vary  depending  on  facility location,  sewage
sludge quantity, proximity of nearby communities, local
topography,  and the land application practices being
considered. A small community might start with an area 20
km (12.5 miles) in diameter, while a large system may initially
screen a much larger study area. Shaded areas repre-
senting unsuitable locations are marked on the map or the
transparency. If the  initial ring does not have suitable sites,
then  the next ring with a larger diameter should be consid-
ered. It should be remembered that areas that are unsuitable
in their existing state can often be modified to make them
acceptable for sewage sludge application. The necessary
modifications (e.g., extensive grading, drainage structures,
flood control, etc.) may be cost-effective if the site is other-
wise attractive in terms of location, low land cost, etc.

5.5.4.1   Contact  with Owners of Prospective Sites

When potential sites are identified, ownership should be
determined.  Often  the City Hall, County Courthouse, or
a real estate broker will have community or  areawide
maps indicating the tracts  of land, present owners,  and
property boundaries. The County Recorder  and title in-
surance companies are also useful sources of informa-
tion  on  property ownership, size of tracts, and related
information.  Contacting landowners prematurely without
adequate  preparation may result in an initial negative
reaction which is difficult to reverse. A public  information
program should be prepared (see Chapter 12), and local
political support secured.  The  individuals  involved in
making  the initial owner contacts should be knowledge-
able  about potential program benefits and constraints.

Initial contacts concerning the proposed project should
be made with the prospective landowners/site managers
through personal interviews. Initial contacts via telephone
are not recommended  to avoid misunderstandings re-
garding the  benefits of a land application program.

Ideally, the Phase  I site evaluation  and screening proc-
ess  will identify two or three sites that merit a more
detailed Phase II site evaluation, discussed  below.

5.6   Phase II Site Evaluation: Field
      Investigation

The  Phase II site evaluation step involves field investi-
gations  of one or more sites to  determine whether soil
survey and  other map  information  used  in the Phase  I
                                                   49

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site evaluation and screening process is accurate and
to obtain additional, more detailed information required for
final selection of the land application practice (Section 5.7)
and final site selection (Section 5.8). Chapter 6 covers
the following aspects of Phase II investigations:

• Preliminary field site surveys.

• Procedures for detailed site investigations.

• Special considerations  for detailed site evaluations
  for  different land application practices: agricultural,
  forest land, reclamation sites, and public contact sites.

5.7   Selection of Land Application
      Practice

When the most feasible land application  practices have
been  identified (e.g., application to agricultural land,
forests, reclamation sites,  public contact sites, or lawns
and home gardens),  preliminary estimates  of site  life
and costs (capital and O&M) for the individual practices
should be made (see Section 5.8.1). Potential social and
environmental impacts resulting from each practice also
should be assessed. Comparing these data  should  re-
veal the most suitable land application practice that  fits
both the needs of the wastewater treatment facility and
local conditions. The facility might also consider adopt-
ing more than one land application practice  (e.g., agri-
cultural  and forest land  application)  if  the  combined
practices  appear to be cost-effective. The  flow chart
shown in Figure 5-3 summarizes the procedure for se-
lecting a  land application  practice.

A checklist  of relevant design  features for  each land
application site is usually helpful for compiling informa-
tion and provides baseline data for cost estimates (Table
5-12). Individual practices can be compared and evalu-
ated based on both quantitative and qualitative factors:

• Estimated costs

• Reliability

• Flexibility

• Land area requirements and  availability

• Land use effects

• Public  acceptance

• Regulatory requirements (federal, state, and local)

A qualitative comparison of each land application practice
is based  on the experience and judgment of  the project
planners and designers. This is more difficult than a cost
comparison, because  the  level of each impact is more
ambiguous and subject to differences of opinion.

5.8   Final Site Selection

The final selection of the site(s) is often a  simple decision
based on the availability of the bestsite(s). This is frequently
the case  for small communities.  If,  however,  the  site
selection process is complex, involving many potential
sites and/or several sewage sludge use and/or disposal
practices, a weighted scoring system may be useful.

The use of a quantitative scoring system for site selection
is demonstrated in the Process Design Manual for Surface
Disposal of Sewage Sludge and Domestic Septage (U.S.
EPA, in preparation). While the criteria for selecting site(s)
for the land application practices discussed in this manual
differ somewhat from those provided in the surface  dis-
posal design manual, the weighting and scoring system
may be useful. Table 5-13 presents another example  of a
ranking system for forest sites, based on consideration of
topography,  soils  and  geology, vegetation, water re-
sources, climate, transportation, and forest access.

Several other considerations should be integrated  into
the decision-making process, including:

• Compatibility of sewage sludge quantity and quality
  with the specific land application practice selected.

• Public acceptance of both the practice(s) and site(s)
  selected.

• Anticipated design life,  based on assumed  applica-
  tion rate, land availability (capacity), projected heavy
  metal loading rates (if Part 503 cumulative pollutant
  loading  rates are being met, as defined in  Chapter
  3), and  soil properties.

5.8.1  Preliminary Cost Analysis

A preliminary estimate of relative costs should be made
as part of the  site selection process.  These estimates
are necessary  for comparing  alternative  sites and/or
land application practices.

Proximity of the sewage sludge land application site to
the wastewater treatment facility is very important in the
decision-making  process  because  of  transportation
costs. Further, the cost of sludge dewatering equipment
should be evaluated in  view of estimated  fuel savings
through decreased total loads and/or  shorter haul  dis-
tances.  For ease of comparison, all costs can be ex-
pressed in dollars per  dry weight of sewage sludge.
Capital costs should be estimated over the life of the
site, whereas operating costs should be estimated an-
nually.  Cost factors that are of prime importance  are
summarized in Table 5-14. These assessments should
be based on experience and best engineering judgment.
Chapter 16 discusses cost estimations in more detail.

5.8.2  Final Site Selection

The Phase I and Phase II site evaluation process should
result in detailed  information on two or more sites that
have been identified as suitable for the selected land
application practice. This information, combined with the
preliminary cost analysis (Section 5.8.1) should provide
                                                   50

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                               Technical Assessment and Preliminary Planning
                               (Chapter 5)
                               Factors for Consideration
                                 • Regulatory Requirements (federal/state/local)
                                 • Sludge Suitability
                                 • Public Acceptance
                                 • Land Area Requirement
                                 • Transport Feasibility
        ^~^\
        (   Practice   )
        \0nly      J
                                                      i
Site Evaluation and Selection (Chapters 5 and 6)

Factors for Consideration
  • Land Use (current and future)
  • Zoning Compliance
  • Aesthetics
  • Physical Characteristics of Site (soil
    characteristics, hydrogeology, etc.)
  • Site Acquisition
               /""T
               \Pr
                                                 Two or More
                                                 Practlces
         Goto
         Appropriate
         Process Design
         Chapter
         (Chapters 7
         through 10)

Factors for Consideration
  •  Cost Effectiveness
  •  Long-Term Environmental Impact
  •  Other Qualitative Impacts
      - Implementability
      - Reliability
      - Flexibility
      - Land-Use Effects
      - Public Acceptability
      - Legislation
Review the following chapters as necessary
  •  Process Design Chapters (Chapters 7
    through 10)
  •  Facility Design and Cost Guidance (Chapters 14
    and 16)
  •  Operation and Management (Chapter 15)
Look for
Other
Alternative
                             S  C
                             \o
                                                                Combination
                                                                of Practices
                                             Implement the Practice
                                             or the Combination
Figure 5-3.  Planning, site selection, and land application practice selection sequence.
                                                       51

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Table 5-12.   Example Design Features Checklist/Comparison of Candidate Land Application Practices

                                                                      Candidate Practice or Combination of Practices
Subject                                                      Agriculture                  Forest                 Reclamation

 1.  Distance and travel time from POTW to the
    candidate site
 2.  Distance and travel time from the storage
    facility to the candidate site
 3.  Distance from the nearest existing development,
    neighbors, etc., to the candidate site
 4.  Sludge modification requirements, e.g.,
    dewatering
 5.  Mode of sludge transportation
 6.  Land area required
 7.  Site preparation/construction needs:
    a. None
    b. Clearing and grading
    c. Access roads (on-site and off-site)
    d. Buildings, e.g., equipment storage
    e. Fences
    f. Sludge storage and transfer facilities
    g. On-site drainage control structures
    h. Off-site runoff diversion structures
    i. On-site runoff storage
    j. Flood  control structure
    k. Ground water pollution control structure,
      e.g., subsurface drain system
    I.Soil modification requirements,
      e.g., lime addition,  etc.
 8.  Equipment needs:
    a. Sludge transport vehicle
    b. Dredge
    c. Pumps
    d. Crawler tractor
    e. Subsurface injection unit
    f. Tillage tractor
    g. Sludge application  vehicle
    h. Nurse tanks or trucks
    i. Road sweeper
    j. Washing trucks
    k. Irrigation equipment
    I. Appurtenant equipment
 9.  Monitoring requirements:
    a. Soil
    b. Sludge analysis
10.  Operational needs
    a. Labor
    b. Management
    c. Energy
    d. Repair
                                                               52

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Table 5-13.  Relative Ranking for Forest Sites for Sewage
           Sludge Application3
Table 5-14.  Cost Factors To Be Considered During Site
           Selection
Factor
                                          Relative Rank
Topography

Slope
   less than 10%                            High
   10-20%                                 Acceptable
   20-30%                                 Low
   over 30%                                Low

Site continuity (somewhat subjective)
   no draws, streams, etc., to buffer            High
   1 or 2 requiring buffers                     Acceptable
   numerous discontinuities                   Low

Transportation

Distance                                   Low-High

Condition of the  roads                        Low-High

Travel through sensitive areas                  Low-High

Forest Access System

Percent of forest system  in  place               Low-High

Ease of new construction
   easy  (good soils, little slope,                High
   young trees)
   difficult                                  Low-Acceptable

Erosion hazard
   little (good soils, little  slope)                 High
   great                                   Low-Acceptable

Soil and Geology

Soil type
   sandy gravel (outwash, Soil Class I)          High
   sandy (alluvial,  Soil Class II)                High
   well graded loam (ablation till, Soil Class IV)   Acceptable
   silty (residual, Soil Class V)                 Acceptable
   clayey (lacustrine, Soil Class IV)             Low
   organic (bogs)                            Low

Depth of soil
   deeper than  10 ft                          High
   3-1 Oft                                  High
   1-3 ft                                   Acceptable
   less than 1 ft                            Low

Geology (subjective, dependent upon aquifer)
   sedimentary  bedrock                       Acceptable-High
   andesitic basalt                           Acceptable-High
   basal tills                                Low-Acceptable
   lacustrine                                Low

Vegetation

Tree species
   Hybrid cottonwood (highest N uptake rates)    High
   Douglas-fir                               High
   other conifers                            High
   other mixed hardwoods                     Acceptable
   red alder                                Low
a basis for selecting the most cost-effective site or sites.
The next section provides an example of the site evalu-
ation and selection process.

5.9   Site Selection  Example

Each  of the  process  design chapters  (Chapters  7
through 9) provides a detailed example of the design of
Capital Costs
•  Land acquisition—purchase, lease, or use of private land.
•  Site preparation—grading, roads, fences, drainage, flood
   control, and buildings (if needed).
•  Equipment—sludge transport and application.
•  Sludge storage facilities.
Operating Costs
•  Fuel for sludge transport  and application.
•  Labor (transport, application,  maintenance, sampling, etc.)
•  Equipment repair.
•  Utilities.
•  Monitoring, if required (laboratory analysis, sample containers,
   shipping).
•  Materials and  miscellaneous supplies.
a specific land application system for agricultural, forest,
and reclamation sites. This section provides a brief ex-
ample of the site selection procedure that could be used
for a typical medium-sized community.

5.9.1   City Characteristics

• Population-34,000.

• Wastewater volume-0.18 m3/s (4 mgd).

• Wastewater  treatment  facility  description-conven-
  tional  activated  sludge, with anaerobic digestion of
  primary and waste-activated sludges.

5.9.2   Sewage Sludge and Soil Characteristics

• Daily sludge generation-2.36 dry t/day (2.6 dry T/day).

• Average solids content-4 percent.

• Average chemical properties (dry weight basis):
  - Total  N-3 percent
  - NH4-N-1  percent
  - Total  P-2 percent
  - Total  K-0.5 percent

• Metal  regulated by Part 503 (in mg/kg):
  -As-10             - Hg-7
  - Cd-19            - Mo-12
  - Cr-800            - Ni-150
  - Cu-700           - Se-19
  - Pb-500           - Zn-2,000

• Soil is maintained at pH 6.5 or above when required
  for optimum crop production.

5.9.3   Regulations Considered

Assume that agricultural land application  is the only
practice being considered, and that special permits are not
required for sewage sludge application, provided that:
                                                        53

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1.  Annual sewage sludge applications do not exceed either
   the agronomic rate or the Part 503 limits for metals.

2.  Annual program for routine soil testing (N, P, K) and
   lime requirement (pH) is implemented.

3.  Wastewater treatment plant measures the chemical
   composition of sludge.

4.  Records  are  maintained  on the  location  and the
   amount of sludge applied.

5.  The  site is not  10  meters or less from waters
   classified as waters of the United States.

5.9.4  Public A cceptance

Assume that public acceptance of land application of
sewage sludge  is judged to be  very good. Several
nearby communities have previously established agri-
cultural land application programs with excellent results.
Sewage sludge characteristics from these communities
were similar, as were farm management and  cropping
patterns involving corn,  oats, wheat,  and  pastureland.
Several articles had appeared  in the local newspaper
indicating that escalating landfill costs were causing the city
to study various sewage sludge use and disposal alterna-
tives. No public opposition groups are known to exist.
               i                  i
               r  _	 ___ 	 _ _ _ _
Figure 5-4.  General area map with concentric rings.
 5.9.5  Preliminary Feasibility A ssessment

The above preliminary information was sufficiently en-
couraging to warrant further study of agricultural land
application.

5.9.6  Estimate Land Area Required

An application  rate of 22.4 t/ha/year (10 T/ac/year) was
used as a first  approximation (see Table 5-1). The acre-
age required for the city was estimated as follows:
            .   .  2.36t/dayx365days/yr
Acreage needed =	__  . ...  ,—-—— = 38.4 ha
     a                 22.4 t/ha/yr
Thus, assume 40 ha (100 ac) for the preliminary search.

5.9.7  Eliminate Unsuitable Areas

Figure 5-4 shows a general area map containing the city
and surrounding communities. Three concentric rings of
10, 20, and 30 km (6.2, 12.4, and  18.6 mi) were  drawn
around the wastewater treatment facility. Areas directly
south of the facility were immediately excluded because
of the city boundaries. Similarly, areas east and  south-
east were excluded because of the city's  projected
growth pattern, the encroachment  of a neighboring city,
and the municipal airport. Further investigations to iden-
tify potential land application sites were thus concen-
trated to the  west and northwest.
           LEGEND
                  DEEP,  HELL-DRAINED TO POORLY DRAINED,
                  MEDIUM TEXTURED AND MODERATELY FINE
                  TEXTURED, NEARLY LEVEL SOILS THAT
                  FORMED IN ALLUVIUM


                  DEEP.  SOMEWHAT POORLY DRAINED TO HELL
                  DRAINED, MEDIUM-TEXTURED, NEARLY LEVEL
                  TO STEEP SOILS THAT FORMED IN LGESS
                  AND THE UNDERLYING OUTWASH,  IN LOESS
                  AND THE UNDERLYING GLACIAL TILL OK
                  IN GLACIAL TILL


                  MODERATELY DEEP AND DEEP, WELL-DRAINED,
                  MEDIUM-TEXTURED.  GENTLY  SLOPING TO STEEP
                  SOILS  THAT FORMED IN  LOESS AND THE
                  UNDERLYING SANDSTONE  AND SHALE RESIDUUM
Figure 5-5.  General soil map showing area selected for sewage
          sludge land application.
                                                   54

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5.9.8  Identify Suitable Areas


Soil maps obtained from the local SCS office were exam-
ined within the three radii selected. Areas within the 10-km
(7-mi) ring were given first priority because of their prox-
imity  to the wastewater treatment facility. Sufficient  land
was located within this distance, and the areas contained
within the second and third radii were not investigated.

Table  5-15.  Ranking of Soil Types for Sewage Sludge Application

                                Depth to
Figure 5-5 is a general soil map showing one potential
area  available for sewage sludge land application. A
detailed soil map of the area is shown in Figure 5-6, and
the map legend is presented in Table 5-15.
Information  presented in the soil survey  report included:
slope, drainage, depth to seasonal water table, and depth to
bedrock. Cation exchange capacities (CEC) were estimated
Soil Type
AvA"
Ca"
CnB2**
CnC2
CnC3
Cn02
Cn03
Fe**
FoA"
FoB2
FoC3
Ge
Hh
La
MbA
MbB2
Md
NgA"
NgB2"
NnA
RnF
Ro"
Rp
RsB2
Sc
Sh"
Sm
Sz
We"
Wh"
Slope
Percent
0-2
0.2
2-6
6-12
6-12
12-18
12-18
0-2
0-2
2-4
6-12
0-2
0-2
0-2
0-2
2-6
0-2
0-2
2-6
0-2
0-2
0-2
0-2
2-6
0-2
0-2
0-2
0-2
0-2
0-2
Seasonal High Bedrock
Water Table (ft) (ft)
1-3 >15
>6 >15
>6 >15
>6 >15
>6 >15
>6 >15
>6 >15
3-6 >15
>6 >15
>6 >15
>6 >15
>6 >15
1-3 >10
>6 >15
>6 >15
>6 >15
3-6 >15
>6 >15
>6 >15
>6 >15
>6 >15
>6 >15
>6 >15
3-6 >15
0-1 >15
1-3 >15
1-3 >15
>6 >15
0-1 >15
1-3 >15
Texture*
sil
sil
sil
sil
sil
sil
sil
sil
I
I
I
I
sil
gsal
I
I
sicl
I
I
I
gi
sicl
sicl
sil
sicl
sil
I
sal
cl
I
Drainage
Class?
P
W
W
W
W
W
W
W
W
W
W
W
SP
W
W
W
MW
W
W
W
E
W
W
MW
VP
SP
SP
W
VP
SP
Approximate
CEC
10-15
10-15
10-15
10-15
10-15
10-15
10-15
10-15
10-15
10-15
10-15
10-15
10-15
>5
10-15
10-15
>15
10-15
10-15
10-15
>5
>15
>15
10-15
>15
10-15
10-15
5-10
>15
10-15
Relative
Ranking*
3
1
1
2
2
3
3
2
1
1
2
1
3
1
1
1
2
1
1
1
1
1
1
2
3
3
3
1
3
3
* I, loam; gsal, gravelly sandy loam; sil, silt, loam; sicl, silty clay loam; cl, clay loam; sal, sandy loam; gl, gravelly loam.
f E, excessively drained; W, well drained; MW, moderately well drained, SP, somewhat poorly drained; P, poorly drained; VP, very poorly drained.
* 1, 0-6 percent slope, >6 ft to water table and >15 to bedrock. 2, 6-12 percent slope or 3-6 ft to water table. 3,12-18 percent slope or 0-3 ft to water table.
"Soil types present on potential site (see Figure 5-6). Soil type information from SCS county soil survey.
                                                        55

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   Wfc
Figure 5-6.  Detailed soil survey map of potential site for sew-
           age sludge land application. (Areas not suitable for
           use are shaded; see Table 5-17 for ranking of soil
           types.)

from texture,  and a ranking  was developed to estimate
soil suitability for sewage sludge application.
Since the  detailed soil  map was  based on an  aerial
photo, farm buildings, houses, etc., were usually iden-
tifiable. Certain portions within this area were excluded,
including:
• Areas in close  proximity to houses, schools, and
  other inhabited buildings.
• Areas immediately adjacent to ponds, lakes, rivers,
  and streams.
The excluded areas were shaded  (Figure 5-6), using  a
mylar overlay. The  remaining unshaded areas, covering
about 930 ha (2,300 ac), were generally pastureland with
some fields of corn  and oats. Within this area was about
175 ha (432 ac) which ranked in Category 1 in Table 5-15.
The land in the site area was owned by three individuals.
Since the 175 ha (432 ac) was far in excess of the 40 ha
(100 ac) required, no further sites were investigated. Soils
present in  the area were generally silt loams. Repre-
sentative soil analysis was as follows:
• CEC  - 10 meq/100 g.
• Soil  pH - 6.0  (1:1 with water).
• Available P -  16.8 kg/ha (15 Ib/ac).
• Available K -  84  kg/ha (75 Ib/ac).
• Lime necessary to raise pH to 6.5 - 5.4 t/ha (2.4 T/ac).
The three  landowners were contacted  individually to
determine their willingness to participate. All expressed
considerable interest in participating in the  program.

5.9.9   Phase II Site Survey and Field
        Investigation
These efforts confirmed the suitability of  the site  se-
lected.  Agreements were thus made  with each land-
owner to land apply municipal sewage sludge.
5.9.10  Cost Analysis

No land  costs  were  incurred since the  landowners
agreed to accept the sewage  sludge. Capital costs in-
cluded:  transportation  vehicle,  application  vehicle,
sludge-loading apparatus with pumps, pipes, concrete
pad, electrical controls, and storage facilities. Annual
costs for this system were estimated to be $110/dry t
($98/dry T), as compared to $128/dry t ($116/dry T) for
landfilling the sludge at a site  25  km (15.5 m) from the
wastewater treatment facility.

5.9.11  Final Site Selection

The 175 ha (432 ac) of best quality land were distrib-
uted over seven  individual fields,  several of which
were not serviced  by all-weather roads. These fields
would  only  be used if complicating factors (e.g., field
or crop conditions) rendered the other fields unusable.
The contractual agreement with  the three  individuals
specified that sewage sludge would be land applied
to certain fields (to be determined at owner discretion)
at rates commensurate with crop  nitrogen require-
ments and  in compliance with the Part 503  pollutant
limits for metals and other Part 503, state, and local
regulatory requirements.

5.10  References

When  an NTIS number is cited in a reference, that
document is available  from:
    National Technical  Information Service
    5285 Port Royal Road
    Springfield, VA 22161
    703-487-4650
Gulp, G., J. Faisst, D. Hinricks, and B. Winsor. 1980. Evaluation of
   sludge management systems: Evaluation checklist and supporting
   commentary. EPA/430/9-80/001 (PB81108805). Cul/Wesner/Culp,
   El Dorado Hills, CA.
Deese,  P., J. Miyares, and S. Fogel. 1980. Institutional constraints
   and  public  acceptance barriers to utilization of municipal waste-
   water and sludge for land reclamation and biomass production: A
   report to the  president's council on environmental quality. (EPA
   430/9-81-013; July 1981).
Keeney, D., K.  Lee, and L. Walsh. 1975. Guidelines for the application
   of wastewater sludge to agricultural land in Wisconsin. Technical
   Bulletin 88, Wisconsin Department of Natural Resources, Madison, Wl.
Sagik, B., B.  Moore, and C. Forber. 1979.  Public health aspects
   related to the land application of municipal sewage effluents and
   sludges. In: Sopper, WE., and S.M.  Kerr, eds. Utilization of municipal
   sewage effluent and sludge on forest and disturbed land. Pennsyl-
   vania State University Press, University Park, PA. pp. 241-263.
U.S. EPA. 1995. Process design manual: Surface disposal of sewage
   sludge and domestic septage. EPA/625/R-95/002. Cincinnati, OH.
U.S. EPA. 1984. Environmental regulations and technology: Use and
   disposal of municipal wastewater sludge. EPA/625/10-84-003.
   Washington, DC.
                                                      56

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                                                 Chapter 6
                                        Phase II Site Evaluation
6.1    General

The  Phase I site evaluation and screening process de-
scribed in Chapter 5 will  usually identify a number of
candidate sites for land application of sewage sludge
that  require more detailed investigation before final site
selection. The extent and type of information gathered
in field investigations for a Phase II site evaluation will
vary depending on:

•  Land application practice being considered, e.g., ag-
   ricultural, forest,  or land reclamation.

•  Regulatory requirements.

•  Completeness and suitability of information on soils,
   topography,  and  hydrogeology  obtained from other
   sources (e.g., the  SCS, USGS, etc).

General  site  characteristics can  be obtained  from a
combination of soil  survey maps and site visits. The
principal soil chemical analyses required are soil tests
which are routinely conducted to develop recommenda-
tions for application of conventional fertilizer materials.
Table 6-1 provides  a summary of the site-specific infor-
mation required for different land application  practices.
This information is  of a general nature and can usually
be obtained from site visits without field sampling and
testing. Review of this information may eliminate some
potential sites from further consideration.

6.2    Preliminary Field Site Survey

A field site survey  should be conducted after potential
sites have been  identified in the map  study performed
during the Phase  I site  evaluation.  A drive or walk
through  the candidate areas should verify or  provide
additional information on:

•  Topography. Estimate of slope  both on prospective
   site and adjacent plots.

•  Drainage. Open  or closed drainage  patterns.

•  Distance to surface water.

•  Distance to water supply well(s).
Table 6-1.  Basic Site-Specific Information Needed for Land
          Application of Sewage Sludge

Property Ownership

Physical Dimensions of Site
   a. Overall boundaries
   b. Portion usable for sludge land application under constraints
     of topography, buffer zones, etc.

Current Land Use

Planned Future Land Use

If Agricultural Crops Are  To Be Grown:
   a. Cropping patterns
   b. Typical yields
   c. Methods and quantity of fertilizer application
   d. Methods of soil tillage
   e. Irrigation practices, if any
    f. Final use of crop grown (animal/human consumption,
     non-food chain, etc.)
   g. Vehicular access within site

If Forest Land:
   a. Age of trees
   b. Species of trees
   c. Commercial or recreational operation
   d. Current fertilizer application
   e. Irrigation practices
    f. Vehicular access within site

If Reclamation Site:
   a. Existing vegetation
   b. Historical causes of disturbance (e.g., strip mining of coal,
     dumping of mine tailings, etc.)
   c. Previous attempts at reclamation, if any
   d. Need for terrain modification

Surface/Ground Water Conditions
   a. Location and depth of wells, if any
   b. Location of surface water (occasional and permanent)
   c. History of flooding and drainage problems
   d. Seasonal fluctuation of ground water level
   e. Quality and users of ground water
• Available access roads. All-weather or temporary.

• Existing vegetation/cropping.

A field survey form similar to the one shown in Table 6-2
that records the current condition of all critical factors is
recommended.  The data collected  from various sites
can then be used to update the map overlay (see Chap-
ter  5). The appropriate additional information for differ-
ent land uses in Table 6-1  (agricultural crops, forest land,
reclamation sites) should also be gathered.
                                                      57

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Table 6-2.  Sample Form for Preliminary Field Site Survey


A.    PROPERTY LOCATION        PROPERTY OWNER
     TOPOGRAPHY
     1.  Relief (sharp, flat, etc.).
     2.  Slope Estimate	
     3.  Drainage Patterns
        - Open/Closed	
        - Drainage Class No.*
        -Any Underdrains	
     DISTANCE FROM SITE BOUNDARY TO:
     1.  Surface Water	
     2.  Water Supply Well	
     ESTIMATE OF SITE DIMENSIONS
     1.  Area
     2.  Natural Boundaries
     3.  Fences
E.
     AVAILABLE ACCESS
     1.  Road Types	
     2.  Other 	
G.
EXISTING VEGETATION/CROPS AND COMMONLY USED
CROP ROTATIONS
1.  On-Site	
2.  Neighboring Properties	

SOIL
1.  Texture	
2.  Variability	
•Refer to Soil Conservation Service drainage classes.

6.3   Site-Specific Field Investigations


This section focuses on basic field investigation meth-
ods applicable to agricultural and forest land application
sites, which  typically encompass areas of tens to hun-
dreds of hectares, but for which detailed maps (1:6,000
or less) generally are not available. In general, active
reclamation  sites often have detailed maps and exten-
sive  environmental data that have  been  prepared and
collected as part of the permitting process, so specific
additional information for determining sewage sludge
application rates may not be required. Section 6.5 dis-
cusses special considerations related to investigation of
reclamation  sites involving abandoned land.

Where land  application of bulk sewage sludge is being
considered for public contact sites, such as parks, de-
tailed site maps may be available that can be used for
the type  of  investigations described here. Otherwise,
field  investigation procedures described in this section
are applicable. Application of bagged sewage sludge on
public contact sites, lawns,  and home gardens will not
require site-specific field investigations.

6.3.1  Base Map Preparation

Major types of commonly available maps that contain
useful information for site field investigations include
(1)  U.S. Geological Survey (USGS)  7.5 minute topo-
graphic maps (scale 1:24,000), (2) published Soil Con-
servation Service (SCS) soil survey maps (which usually
range in scale from 1:15,000 to 1:20,000), (3) Federal
Emergency  Management Agency  (FEMA) floodplain
maps, and (4) U.S. Fish  and Wildlife Service National
Wetland Inventory Maps.

Site boundaries from a recent survey or County records
should be located as accurately as possible on all maps
that have  been collected for the site. The accuracy of
points on  a  USGS 7.5  minute quadrangle map (about
plus or  minus 50 feet)  is  generally  not sufficient for
detailed site evaluation for sewage sludge land applica-
tion, but the expense of preparing a larger scale topo-
graphic base map will usually not be justified. Enlarging
the area of a topographic map that includes the site of
interest  using a copy  machine is the simplest way to
obtain a  larger scale working map for  field investiga-
tions. The same can be done for a soil map of the area,
if available.  The original scale bars of the map should
be  included or enlarged  separately so  that the actual
scale of the  enlarged map can be determined. Informa-
tion from other maps,  such as flood  plain boundaries,
should also be transferred  to the working base  map.
Another way to obtain a larger scale  topographic base
map, if the computer equipment and software are avail-
able, is to obtain the appropriate USGS map in digital
format, which then can be used to print a base map of
the desired area and scale.

6.3.2  Field Checking of Surface Features and
       Marking Buffer Zones on the Base Map

Key point and linear surface features on the base map
that should  be added  or checked in  the field include:
(1)  location  of surface water  features (springs, inter-
mittent and  perennial surface streams, ponds and
streams);  (2) location of ground water wells, and (3)
location of  residences, other buildings, public roads,
fencelines and other man-made features. Accuracy of
surface  features  on the  enlarged base map can be
checked by first measuring distances between points on
the map that can be easily located in the field, and then
measuring the actual distance. For example, measuring
the distance of a site corner by a roadway from the point
that a stream crosses the site boundary at the road is
relatively easy to measure in the field by  pacing or using
a 100-ft tape measure. Any major features that are not
within about 10 feet of the  marked location  on the en-
larged topographic base map should  be redrawn.  Also,
                                                   58

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any significant surface features that are not on the base
map should be added.

The field-checked and revised base map allows reason-
ably accurate delineation  of  any  buffer zones where
sewage sludge should not be applied. The Part 503 rule
specifies  a minimum  buffer of 10 meters from surface
waters at a land application site unless otherwise speci-
fied by the  permitting authority.  Many states specify
larger buffers to surface waters and may specify buffers
to wells, dwellings, property lines, and  other features.
Any applicable setback distances should be marked  on
the field-checked  base map.

6.3.3  Identifying Topographic Limitations

Many state regulatory programs define slope grade lim-
its for land application of sewage sludge that may vary
according  to  the  type of  land  use (e.g.,  agricultural,
forest, or reclamation site) and  method of application
(Table 5-8). The appropriate regulatory authority should
be  contacted  to identify any slope limitations that might
apply to the site. An SCS soil survey (see Section 6.3.4)
is the easiest way to identify areas with similar slope
ranges because soil map units are usually differentiated
according to slope classes. Soil  map units with slopes
that exceed the applicable  limitations should be marked
as  potentially unsuitable  areas  before  going into the
field.  Depending  on  the  type  of soil  or  application
method (e.g.,  surface application, incorporation, or  in-
jection), different slopes may be appropriate. Areas with
differing slope limits should be  identified  on the same
map;  alternatively, separate maps may  be developed
that identify potentially unsuitable areas because of dif-
fering slope limitations.

The above map(s) needs  to be  taken  into the field  to
check the accuracy of the boundaries  separating suit-
able  and unsuitable  areas based on  slope. In most
situations, spot checking  of actual slope gradients using
a clinometer and  a surveyor's  rod  will be adequate
(Boulding, 1994 and U.S. EPA, 1991 describe this pro-
cedure in more detail). Such  field checking is likely to
result in slight to moderate adjustments to the bounda-
ries delineating areas with  unsuitable slopes. The field-
checked topographic boundaries should be marked on the
enlarged topographic base map described in Section 6.3.1.

6.3.4  Field Soil Survey

If available, a county soil survey published by the SCS
is the best single source  of  information about a site
because  it also  provides  an  indication  of subsurface
geologic and  hydrogeologic conditions and contains a
wealth of information on typical soil physical and chemi-
cal characteristics. If a soil survey is not available, check
to see if the current or previous  property owners have
worked with the local Soil and Water Conservation Dis-
trict. If so, an  unpublished farm survey may be on file in
the District SCS office. If an unpublished soil survey is
available, SCS soil series descriptions and  interpretation
sheets should be obtained for all soil series that have
been mapped in the area (see Table 6-3). Estimated soil
properties are typically given as  ranges or values for
different soil  horizons; direct field observation and sam-
pling are required for  more  accurate definition  of soil
properties. Even if a published soil survey is available,
Table 6-3.  Types of Data Available on SCS Soil Series
          Description and Interpretation Sheets

Soil Series Description Sheet

Taxonomic Class
Typical soil profile description
Range of characteristics
Competing series
Geographic setting
Geographically associated soils
Drainage and permeability
Use and vegetation
Distribution and extent
Location and year series was established
Remarks
Availability of additional data

Soil Survey Interpretation Sheet*

Estimated Soil Properties (major horizons)
   Texture c/ass(USDA, Unified, and AASHTO)
   Particle size distribution
   Liquid limit
   Plasticity index
   Moist  bulk density (g/cm3)
   Permeability (in/hr)
   Available water capacity (in/in)
   Soil reaction (pH)
   Salinity (mmhos/cm)
   Sodium absorbtion ratio
   Cation exchange capacity (Me/100g)
   Calcium carbonate (%)
   Gypsum (%)
   Organic matter (%)
   Shrink-swell potential
   Corrosivity (steel and concrete)
   Erosion factors (K, T)
   Wind erodability group
   Flooding (frequency, duration, months)
   High water table (depth, kind, months)
   Cemented pan (depth, hardness)
   Bedrock (depth, hardness)
   Subsidence (initial, total)
   Hydrologic group
   Potential frost action

Use/Suitability Ratings
   Sanitary facilities
   Source material
   Community development
   Water management
   Recreation
   Crop/pasture capability and predicted yields
   Woodland suitability
   Windbreaks (recommended species for planting)
   Wildlife habitat suitability
   Potential native plant community (rangeland or forest)

* Units indicated are those used by SCS.

 Note: Italicized entries are particularly useful for evaluating contami-
 nant transport.
                                                       59

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these sheets provide a convenient reference for charac-
teristics of soil series occurring within a site. The same
information on individual soil series can be found in the
text  portion of an SCS soil survey, but is scattered
through different sections and tables in the report.

Although published soil surveys provide much useful
information for preliminary site selection, they may not
be adequate for site-specific evaluation for land applica-
tion  of sewage sludge. For example,  areas of similar
soils that cover less than 4 or 5 acres are generally not
shown on published SCS county soil surveys. For site-
specific evaluation and design purposes, it is desirable
to identify areas of similar soil characteristics that are as
small as an acre. The SCS may be able to prepare a
more detailed soil survey of a site that has been selected
for land application of sewage sludge. If SCS  has a large
backlog of requests, however, obtaining a more detailed
soil  survey can take  months. A detailed soil survey
prepared by consulting soil scientists will be more ex-
pensive, but will usually involve less delay.  If a private
consultant conducts the soil survey, the person or per-
sons actually carrying  out the survey should be trained
in soil mapping and classification methods used by SCS
for the National Cooperative Soil  Survey.

Field checking of soil map unit boundaries and deline-
ation of smaller units omitted from an existing SCS soil
survey can be done using  an enlarged  soil  map, as
described for the topographic base map in Section 6.3.1.
Alternatively, revised soil map unit delineations or new
mapping can  be done directly on  the working topo-
graphic base map. An added benefit of more detailed
soil mapping at a site is that it will also provide additional
site-specific information for delineation  of  floodplains
and  wetlands  (Section 6.3.5), and for  hydrogeologic
interpretations where ground-water is relatively shallow
(Section  6.3.6). The soil survey will also be helpful  in
planning soil sampling for designing agronomic rates  of
sewage sludge application (Section 6.4).

6.3.5   Delineation of Floodplains and
        Wetlands

Some  state regulatory programs place  restrictions  or
limitations on land application of sewage sludge on  or
near floodplains and wetlands. State floodplain restric-
tions vary, ranging from prohibition of application on the
10-year or  100-year floodplain, to conditions on place-
ment within a floodplain (e.g., incorporation within 48
hours, use  of diversion dikes or other protective meas-
ures). Floodplains  can be easily  identified as low-lying
areas adjacent to streams on topographic maps and as
alluvial soils adjacent  to streams on soil maps. FEMA
maps should  be consulted to determine whether a site
includes a 100-year floodplain. Accurate delineation  of
floodplain boundaries requires detailed engineering and
hydrologic studies. The appropriate regulatory agency
should be consulted to determine whether such detailed
investigations are required, and, if so, to identify recom-
mended procedures.

Wetlands include swamps, marshes, bogs, and any ar-
eas that are inundated or saturated by ground water or
surface water at a frequency and duration to support a
dominant vegetation adapted to saturated  soil  condi-
tions. As with floodplains, an SCS soil survey will indi-
cate whether "hydric" soils are  present at a site (e.g.,
soils that are wet long enough to periodically produce
anaerobic conditions). If wetlands are present at a site,
the appropriate regulatory agency should be contacted
to determine whether their boundaries should be accu-
rately delineated.

Accurate wetland delineation typically requires assess-
ment by a qualified  and  experienced expert in soil sci-
ence and botany/biology to identify: (1) the limits of the
wetland boundary based on  hydrology, soil types,  and
plants types; (2) the type and  relative  abundance of
vegetation, including trees; and (3) rare, endangered, or
otherwise protected species and their habitats, if  pre-
sent. Many methods have been developed for assess-
ing wetlands. The main  guidance manuals for wetland
delineation for regulatory purposes are the Corps of
Engineers Wetlands Delineation Manual (U.S. Army
Corps of Engineers, 1987) and  the Federal Manual for
Identifying  and Delineating  Jurisdictional  Wetlands
(Federal  Interagency Committee for Wetland  Deline-
ation, 1989). The latter manual places greater emphasis
on  assessment of  the  functional value of wetlands,
along the lines  of earlier work by the U.S. Fish  and
Wildlife Service (U.S. Fish and Wildlife Service, 1984).

6.3.6  Site Hydrogeology

The Part 503 rule does  not explicitly require investiga-
tions to characterize ground-water hydrology at sewage
sludge land application sites but does require that sew-
age sludge be land applied at the agronomic rate for N
for the crop or vegetation being grown. As discussed in
Section 6.4.1 on agronomic rates, some knowledge of
depth to ground water is useful when selecting  appro-
priate sites. Tables 5-9 and 5-10 contain general guide-
lines for depth to ground water at land application sites.
Most states have established their own requirements for
minimum depths to ground  water for sewage  sludge
land application sites, which range from 1 ft to 6 ft. Also,
a number of states restrict application on highly perme-
able and/or very slowly permeable soils.

The field soil  survey described in  Section  6.3.4 will
provide the necessary information on  depth to ground
water for most sites. The published soil survey report or
soil  series  interpretation  sheet will  indicate  typical
depths to seasonal high  water table  and  also expected
ranges of permeability for each major soil horizon. If
significant areas of the site have relatively shallow water
                                                   60

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tables (<3 feet), it may be desirable to prepare a more
detailed depth-to-water-table map based on  soil mor-
phology, as described below. Soils with very high or very
slow permeability, as indicated by the soil survey, should
be eliminated as areas for land application of sewage
sludge, if possible. If elimination of such areas places
too great a restriction on suitable areas for land applica-
tion,  it may be necessary to conduct field infiltration and
permeability tests to determine whether areas of these
soils may be suitable.

6.4   Soil Sampling and Analysis to
      Determine Agronomic Rates

6.4.1  Part 503 Definition of Agronomic Rate

Designing the  agronomic rate for land application  of
sewage sludge is one of the key elements in the Part
503  rule for ensuring that  land application does  not
degrade ground water quality through  nitrate contami-
nation. The Part 503 rule defines agronomic rate as:

   the whole sludge application rate (dry weight
   basis) designed: (1) to provide the amount of
   nitrogen needed by the food crop, feed crop, fiber
   crop, cover crop, or vegetation grown on the land
   and (2) to minimize the amount of nitrogen in the
   sewage sludge that passes below the root zone of
   the crop or vegetation grown on the land to the
   ground water. (40 CFR 503.11 (b))

Designing the agronomic rate for a particular area re-
quires knowledge of (1) soil fertility, especially available
N and P; and (2) characteristics of the sewage sludge,
especially amount and forms of N (organic N, NH4, and
NO3). The complex interactions between these factors
and climatic variability (which affects soil-moisture re-
lated N transformations) make precise prediction of crop
N requirements difficult.

Nitrogen fertilizer recommendations have historically
been based primarily on experience from replicated
field trials of crop response on different soil types and
management practices.  Nitrogen fertilizer recommen-
dations based on such studies often vary regionally.
The high organic N content of sewage sludge, which
becomes available for plant uptake over a period of
years  as  it is  gradually  mineralized, requires  an
approximate mass balance that accounts for N needs
of the crop, availability of N in the sewage sludge and the
soil, and losses (such as volatilization and denitrification).

Chapter 7 and Chapter 8 address in detail mass balance
methods for designing agronomic rates at agricultural
and forest sites.

6.4.2  So/7 Sampling

Soil sampling and analysis will usually not be needed at
land  application sites  until  the site  has been selected
and it is time to calculate sewage sludge application
rates. Soil sample collection procedures are described
in Chapter 13. The types of analyses performed on soil
samples will vary somewhat depending on the crop and
state regulatory requirements.  Major constituents  that
may need to be tested include:

• NO3-N as an indicator of plant-available N in the soil.
  NO3 root zone profiles are widely used in  states west
  of the Missouri River where precipitation and leaching
  are relatively low (Keeney,  1982). The pre-sidedress
  nitrate test (PSNT), where  soil NO3-N is  sampled to
  a depth of 0.3 to  0.6 m prior to corn planting or in
  early June, has  been found to be a good  indicator of
  plant-available N  in  humid  areas (Magdoff et al.,
  1984; Sander et al., 1994). Where  applicable, these
  tests should be made for calculating initial  sewage
  sludge application  rates, and can  possibly be used
  in subsequent years  as a more accurate alternative
  to the equations in Chapters 7 and 8 for estimating
  N mineralization rates.  Chapter 13 discusses these
  tests in more detail.

• C:N ratio, which provides an  indication of the poten-
  tial for immobilization of N  in  sewage sludge as  a
  result of  decomposition of plant residues in the soil
  and at the soil surface. This is especially  relevant for
  forest land application sites, as discussed in Chapter 8.

• Plant-available P. Where sewage sludge is applied at
  rates to supply plant N needs, this test is  less critical.
  This test  is essential, however, if sewage sludge ap-
  plication  rates are to be based on plant P require-
  ments (see Chapter 7).

• Plant-available K. This is required to determine supple-
  mental K fertilization needs for optimum plant growth.

• Soil pH and pH  (e.g., lime) adjustments. A soil pH of
  approximately 6.5  maximizes the  availability of soil
  nutrients to plants  and immobilization of trace metals.
  Where soil pH is lower than  6.5, lime or other alkali
  amendments are often added to the soil  to bring pH
  to the desired level.

6.5   Special Considerations for
      Reclamation  Sites

At reclamation sites involving abandoned mined land,
field investigations to characterize ground-water distri-
bution and quality are usually required. The detailed site
investigation should determine the following:

• Depth to  ground water,  including seasonal variations

• Quality of existing ground water

• Present and potential future use of ground water

• Existence of perched water

• Direction  of ground water flow
                                                  61

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6.5.1   Sampling and Analysis of Disturbed Soils

Sampling and analysis of soils at reclamation sites are
necessary to:

• Establish sewage  sludge application rates (typically
  for a single or several  [e.g., three] application(s)  at
  reclamation sites).

• Determine amounts of supplemental  fertilizer,  lime,
  or other soil amendment required to obtain desired
  vegetative growth.

• Determine the infiltration and permeability charac-
  teristics  of the soil.

• Determine  background  soil pH,  metals,  nutrients,
  etc., prior to sewage sludge application.

Soil survey maps will usually provide only an idea of the
type of soil present prior to the disturbance. Often, the
only soil profile  present on  a surface-mined site is the
mixture of soil and geologic materials, and the physical
and chemical characteristics  of the  mixture can  vary
greatly over relatively short distances. A field inspection
will need to be  made to  determine the number and
location of samples necessary to characterize the ma-
terials. The specific analyses  needed may vary from
location to location based on state and local regulations
covering both the reclamation and sewage sludge land
application aspects. Chapter 13 describes disturbed soil
sampling procedures further.

Nitrogen and phosphorus  are generally deficient on
disturbed  lands, and phosphorus is often the  most
limiting fertility factor in plant  establishment on drasti-
cally disturbed land (Berg, 1978).  Soil tests used for
P analysis reflect the chemistry of soils, and thus are
more regionalized than tests for other major nutrients.
A number of soil tests have been developed for use
on  acid  soils  in the eastern  United States and on
neutral and  calcareous soils in  the west. Drastically
disturbed lands, however, do notalways reflect the local
soils. Thus,  if disturbed spoil material is going to be
analyzed for P, the local routine analysis procedure may
not be appropriate, and other P analyses might be re-
quired. Recommendations should be obtained from the
local agricultural experiment station. Testing for pH re-
quires sufficient sampling of surface  soils to charac-
terize variations in pH; coring may be required to identify
any subsurface distribution of toxicor acid-forming spoil
material.


6.6   References

Berg, W.A. 1978. Limitations in the use of soil tests on drastically
   disturbed lands. In: F.W. Schallerand P. Sutton, eds. Reclamation
   of drastically disturbed lands, American Society of Agronomy,
   Madison, Wl. pp. 563-664.

Boulding, J.R. 1994.  Description and sampling of contaminated soils:
   A field guide, 2nd ed. Chelsea, Ml: Lewis Publishers.

Federal Interagency Committee for Wetland Delineation. 1989. Fed-
   eral manual  for identifying and delineating jurisdictional wetlands.
   Cooperative Technical Publication, U.S. Army Corps of Engineers,
   U.S. Environmental Protection Agency, U.S. Fish and Wildlife
   Service, and U.S. Department of Agriculture Soil Conservation
   Service, Washington, DC.

Keeney, D.R. 1982.  Nitrogen-availability  indices. In: A.L. Page, ed.
   Methods of  soil analysis,  part 2, 2nd ed. American Society of
   Agronomy, Madison, Wl. pp. 711-733.

Magdoff, F.R., D. Ross, and J. Amadon. 1984. A soil test for nitrogen
   availability to corn. Soil Sci. Soc. Am. J. 48:1301-1304.

Sander, D.H., D.T. Walthers, and K.D. Frank. 1994. Nitrogen testing for
   optimum management. J. Soil and Water Conserv. 49(2):46-52.

U.S. Army Corps of Engineers. 1987. Wetlands delineation manual. Tech-
   nical Report Y-87-1. Waterways Experiment Station, Vicksburg, Ml.

U.S. EPA. 1991. Description and sampling of contaminated soils: A
   field pocket  guide. EPA/625/2-91/002. Cincinnati, OH.

U.S. Fish and Wildlife Service. 1984. An overview  of major wetland
   functions and values. FWS/OBS-84/18. Washington, DC.
                                                      62

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                                             Chapter 7
                 Process Design for Agricultural Land Application Sites
7.1   General

Agricultural land is the type of land most widely used for
the application of sewage sludge. This chapter presents
detailed design information for the application of sewage
sludge to agricultural land, placing primary emphasis on
the growing of crops such as corn,  soybeans, small
grains, cotton, sorghum, and forages. The design exam-
ple presented  at the end of this chapter assumes that
the designer has (1) selected agricultural land applica-
tion;  (2) completed  preliminary planning (see Chapter
5); and  (3) chosen  a transportation system to  convey
sewage sludge to the application site (see Chapter 14).

The design approach presented in this chapter is based
on the use of sewage sludge as a low-nutrient fertilizing
material that can partially replace commercial fertilizers.
The  goal of this approach  is to optimize  crop yields
through  applications of both sewage sludge and supple-
mental fertilizers, if needed. The sewage sludge appli-
cation rate  is typically designed for either the nitrogen
(N) or phosphorus (P) needs of the crop grown on a
particular soil.  In addition, the sewage sludge applica-
tion rate must be consistent with federal, state, and local
regulations relative to pathogens, metals, and organics
contained in the sewage sludge and  related require-
ments for vector attraction reduction.

The design  example presented at the end of this  chapter
also assumes that basic sewage sludge and crop  produc-
tion information has  been collected. The sewage sludge
composition data needed to meet regulatory requirements
and ensure good design are described in Chapter 4.

Other concerns regarding agricultural land application in-
clude the possibility of odors or potential exposure to
pathogens due to inadequate sewage sludge treatment or
poor site management. The design approach described in
this chapter assumes that the sludge has been properly
stabilized to meet pathogen and vector attraction reduction
requirements and reduce  odor potential.

Community acceptance of a land application project will
be more readily forthcoming if local participation is assured.
The initial task for obtaining public support  begins with
the selection of a project team whose members can offer
technical service and expertise (see Chapter 12).
Information must  also be available on the types of crops
to be grown, attainable yield level, and the relationship
between soil fertility tests and recommended fertilizer ap-
plication rates.  The overall goal is to develop a nutrient
management plan for the use of sewage sludge and fertil-
izer to meet the nutrient needs of the crop to be grown.

7.2   Regulatory Requirements and
      Other  Considerations

Chapter 3 presents the requirements specified by the
federal Part 503 regulation. When designing  a land
application system, check with state and local agencies
to learn about any other requirements that must be met.
Information on  other key design considerations, such as
nutrients, pH, and land application of sewage sludge on
arid lands, is discussed below.

7.2.1  Nitrogen and Other Nutrients

7.2.1.1   Nitrogen

Nitrogen is the  nutrient required in the largest amounts by
all crops. The addition of N to  soils in excess of crop needs
results in the potential for NOa-N contamination of ground
water because NO3-N is not  readily adsorbed  by  soil
particles and will move downward as water percolates
through the soil profile. Whether excess N  is applied by
sewage sludge or from excessive applications of animal
manures  or conventional  N fertilizer materials, an  in-
creased  risk of NO3-N loss to ground water may  occur,
depending on climate or crop production  practices. High
NO3-N levels in water supplies may result in health prob-
lems for both infants and livestock (Reed et al., 1994). The
maximum  allowable concentration of NO3-N in drinking
water has been established at 10 mg/L NCVN.
To prevent ground-water contamination by NO3-N,  the
Part 503  rule requires that bulk sewage sludge be ap-
plied to a site at  a rate that  is equal to or less than the
agronomic rate for N  at the  site. This is the rate that is
designed to provide the amount of N needed by the crop
while minimizing  the amount of N in the sewage sludge
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that will pass  below the root zone  of the crop to the
ground water.  The factors that must be considered  in
deriving the agronomic  application rate for a crop site
include, but are not limited to:

• The amount of N needed by the  crop or vegetation
  grown on the land.

• The amount of plant-available N remaining from pre-
  vious applications of N-containing materials (e.g., fertil-
  izers, irrigation water, animal manure, sewage sludge).

• The  amount of organic  N that  is mineralized and
  becomes available each year from previous applica-
  tions of N-containing materials (e.g., sewage sludge,
  animal manure).

• The  amount of N  left from  biological N fixation by
  leguminous  crops that is mineralized  and becomes
  available for crops to  use (i.e., legume credit).

• The  type of soil at the  site  and the amount of N
  mineralized from soil organic matter.

• Denitrification  losses  of  NO3-N and/or volatilization
  losses of ammonia.

• Any other identifiable  sources or losses of N.

The design example in Section 7.5 illustrates the  process
for calculating the agronomic rate.


7.2.1.2   Phosphorus

For most sewage sludge, applying sufficient sludge  to
meet all the crop's N needs will supply  more P than
needed (Jacobs  et al.,  1993).  Phosphorus  does not
usually present a ground-water pollution concern. Some
states limit sludge application to cropland based on P
loading to protect surface water quality. Section 7.4.4.2 and
7.5.3 discuss sewage sludge application rates limited by P.


7.2.1.3   Other Nutrients

Sewage sludge application can be a source of micronu-
trients that are important for plant growth, such as iron
(Fe), manganese (Mn), and  zinc (Zn). But because sew-
age sludge does not contain balanced amounts  of nutri-
ents, an understanding of agronomy and crop production
practices is important to prevent possible disruption of soil
fertility and plant nutrition  when sludge is applied to crops
(Jacobs etal., 1993). For example, at an agricultural site
in Virginia, addition of lime-treated sludge raised the soil
pH to 7.5,  resulting in manganese deficiency in soybeans.
The problem was corrected by application of Mn to foliage,
and the POTW eliminated lime conditioning to prevent ex-
cessive elevation  of soil pH caused by sewage sludge
applications (Jacobs et al., 1993).
7.2.2  So/7 pH and Requirements for pH
       Adjustment
Some states require that soils treated with sludge be
maintained at a pH  of 6.5 or above  to  minimize the
uptake of metals by crops based on previous EPA guid-
ance. The federal Part 503 regulation does not require
a minimum pH of soil because pH was factored into the
risk assessment on  which the regulation was based
(U.S. EPA, 1992). In addition, at least one review of the
literature on how soil pH influences the uptake of metals
suggests that the recommendation of pH 6.5 should be
reconsidered for food-chain agricultural soils, based on
reports that indicate adequate control of metals  uptake
at pH 6.0 (Sommers  et al.,  1987). As discussed above
(Section 7.2.1.3), proper management of soil pH also is
important for good  nutrient availability and crop growth.

Soil pH control has been practiced routinely in those
areas of the United  States where  leguminous crops
(e.g.,  clover, alfalfa,  peas, beans)  are grown. Fortu-
nately, limestone deposits are normally  abundant  in
these regions, resulting in minimal costs associated with
liming soils. Considerable cost, however, may be asso-
ciated with  liming  soils in  other areas of the  United
States (e.g., eastern and southeastern states). Soils in
these regions tend to be naturally acidic, and may re-
quire  relatively  large amounts of limestone (12 to 20
t/ha, or 5 to 8 tons/ac [T/ac]) to maintain  a proper soil
pH. In addition,  the trend toward  increased growth  of
cash grain crops (corn, small  grains)  has resulted  in
greater commercial fertilizer use, which generates acid-
ity that can decrease soil pH.

While maintaining soil pH between 6.5 and 7.0 often is
desirable for optimum availability of essential plant nu-
trients, liming soils is not always necessary to achieve
desired  crop growth. For example,  excellent yields  of
corn, soybeans, and wheat can be obtained at a soil pH
of 5.5 to  6.0. Many soils in most of the western United
States contain free calcium carbonate, which  naturally
maintains a pH of about 8.3. For these types of soils, trace
element deficiencies  rather than toxicities  are a major
concern.  Therefore, the best advice  is to  involve agro-
nomic expertise to  help manage soil pH at the  recom-
mended levels for soils and crops in your state or area.

Soil pH is  buffered by inorganic and  organic colloids.
Thus, it does not increase immediately after limestone
applications, nor does it  decrease soon  after sewage
sludge or N fertilizer additions. If soil pH is less than the
desired  level, a  lime requirement test can be used  to
estimate  the amount of agricultural  limestone required
to adjust the pH. Soil  pH monitoring is discussed further
in Chapter 13.
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7.2.3  Special Considerations for Arid Lands

7.2.3.1   Crop Land

In arid regions (all U.S. lands west of the 100th meridian,
with  less  than  20 inches  of rain annually), sewage
sludge additions can be a significant source of nutrients
and organic matter. Sludge application can often im-
prove soil  physical properties such  as water-holding
capacity,  infiltration,  and  aeration (Burkhardt et al.,
1993).  Sludge application can also increase the protein
content of crops such as winter wheat compared to sites
receiving commercial N fertilizer (Ippolito et al.,  1992).

In arid and semi-arid  climates, evapotranspiration ex-
ceeds  precipitation, minimizing downward migration of
NO3-N. In  low-rainfall and irrigated  areas, sewage
sludge constituents such as soluble salts and boron (B)
should also be considered when determining sludge
application rates. High concentrations of salt in the plow
layer can impair germination and early seedling growth
(Jacobs et al., 1993). Excessive salt can also cause soil
dispersion, reducing water infiltration  rates and soil
aeration and causing soil structure changes that make
tilling more difficult (Jacobs et al.,  1993).

Generally, additions of salts by sewage sludge applica-
tions at agronomic  rates will be low enough to avoid any
salt injury to  crops. In dry climates, however, sewage
sludge can be a source of additional salts to the soil-
plant system, as can other fertilizers, manures, etc. Salt
sources must be  properly managed if optimum crop
growth is to be achieved. Therefore, guidance from land
grant universities or other local sources of agronomic
information should be sought to  help  manage  soluble
salt levels in soils.

7.2.3.2   Rangeland

Application of sewage sludge to  rangeland  (open  land
with indigenous  vegetation) is considered agricultural
land application under the Part 503 regulation. Much of
the arid and  semiarid rangelands in  the western and
southwestern United States have been degraded by
overgrazing, fires,  wind erosion,  and single resource
management practices. Sewage sludge application to
these  lands  can  enhance the  soil  and  vegetation
(Aguilar et al.,  1994). Benefits can include  increased
rangeland  productivity;  improved  forage  quality;  in-
creased rainfall absorption and soil moisture; reduced
runoff;  increased germination and populations of favor-
able grasses; less competition from invading shrubs and
weeds; and decreased erosion  potential (Fresquez et
al., 1990; Pierce et al., 1992; Peterson and Madison,
1992).  In addition, the remote locations of most arid
rangeland sites minimizes public concerns about odors,
vectors, and traffic. Table 7-1 describes projects in which
sewage sludge was applied to arid rangelands.
As Table 7-1 shows, various studies concur that sewage
sludge application to rangelands can improve plant pro-
ductivity without adversely impacting the  environment.
The studies vary, however, regarding what  application
rates of sewage sludge are optimum to use. A study in
Fort Collins, Colorado, reported that an application rate
of 4.5  mg/ha (2 dry T/ac)  would enhance  vegetative
growth with minimum excess NO3-N concentrations in
soil (RDB and COM, 1994), and also indicated that N
levels in soil did not increase at a soil depth of 12 inches
as application rates increased (Gallier et al.,  1993). A
study in the Rio Puerco Watershed in New Mexico indi-
cated that  leaching from saturated  flow would not be
expected to occur below 1.5 m (5 ft) in similar soils in
this semiarid environment (Aguilar  and Aldon, 1991).
Another study in Wolcott, Colorado, reported  potential
NO3-N in surface water runoff at application rates above
20 mg/ha (9 dry T/ac),  while a study at  the  Sevilleta
National Wildlife Refuge in New Mexico reported a re-
duction in surface water runoff at an application rate of
45 mg/ha (20 dry T/ac), with  NO3-N, copper (Cu), and
cadmium (Cd) concentrations in the runoff below state
limits for ground water and for livestock and wildlife water-
ing areas (Aguilar and Aldon, 1991).

A key to successful sewage sludge application on arid
rangelands  is minimizing the disturbance of soil and
vegetation. Once the plant cover is disturbed, recovery
is very slow in the arid conditions, leaving the rangeland
vulnerable to erosion and weed invasion  (Burkhardt et
al., 1993). Section 7.3.1  below discusses  sludge appli-
cation  methods suitable for arid rangelands.

7.3    Application Methods and Scheduling

7.3.1  Application Methods

Methods of sewage sludge application chosen for agri-
cultural land depend on the  physical characteristics of
the sludge and soil, as well as the types of crops grown.
Liquid sewage sludge can be applied by surface spread-
ing or subsurface injection. Surface application methods
include spreading by farm tractors, tank wagons, special
applicator vehicles  equipped with  flotation  tires, tank
trucks, portable  or fixed  irrigation systems, and  ridge
and furrow irrigation.

Surface application  of liquid sludge  by tank  trucks and
applicator vehicles is the most common method used for
agricultural croplands, particularly  when  forage crops
are grown. Surface application of liquid sludge is nor-
mally limited to soils with less than  a 6 percent slope.
Afterthe sludge has been applied to the soil surface and
allowed to partially dry, it is commonly incorporated by
plowing or other tillage options prior to planting the crop
(i.e.,  corn,  soybeans,  small grains, cotton,  other row
crops), unless minimum or no-till systems are being  used.
Ridge and furrow irrigation systems can be designed to
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Table 7-1.  Summary of Research on Sewage Sludge Application to Rangeland (Adapted From U.S. EPA, 1993)


Geographic Location    Plant Community
                   Mean Precip.
                   (cm/yr)
Sludge Loading
(mg/ha, dry)      Significant Results of Study
Wolcott, CO
Meadow Springs Ranch,
Fort Collins, CO
Sevilleta National
Wildlife  Refuge, NM
Rio Puerco
Watershed, NM
western wheatgrass,
alkali bluegrass,
Indian ricegrass
                                         25
blue grama,
buffalo grass,
western wheatgrass,
fringed sage
blue grama,
hairy grama
blue grama,
snakeweed
                                         38
                                         20-25
                                         25
0, 4.5, 9, 13, 18,   Increase in species diversity with sewage
22, 27, 31, 36     sludge application.  Increase in nitrogen
                concentration in soil profile with increasing
                application rates, but did not penetrate below
                90 cm (about 3 ft).  Application rates above
                20 mg/ha (9 T/ac) pose a potential hazard for
                surface water contamination by nitrates (Gallier
                et al., 1993; Pierce, 1994).

0, 2.2, 4.5, 11,     Maximum vegetative growth was obtained at
22, 34           an application rate of 11 mg/ha (5 T/ac).  An
                application rate of 4.5 mg/ha (2 T/ac) of
                sewage sludge would increase vegetative
                growth and minimize excess nitrate
                concentrations in soil (RDB and COM, 1994).
                Nitrogen levels in soil ceased to increase
                below 1 ft  (Gallier et al., 1993).

45              Reduction  in runoff volumes due to increased
                water absorption and surface roughness
                resulting from sewage sludge application.
                Nitrate concentrations in runoff were well below
                recommended NM standard of 10 mg-N/l
                (Aguliar and Loftin, 1991; Aguilar et al, 1992).

0, 22.5, 45, 90     An increase of 2 to 3 fold in blue grama forage
                production  was found for sludge applications of
                45 and 90  mg/ha (20 and 40 T/ac). A decrease
                in snakeweed yield was found, allowing forage
                to increase (Fresquez et al., 1991). Sludge
                applications of 22.5 and 45 mg/ha (10 and 20
                T/ac) produced the most favorable vegetative
                growth responses, whereas applications of 90
                mg/ha (40  T/ac) did not significantly increase
                yield (Fresquez et al., 1990).
apply sewage sludge during the crop growing season.
Spray irrigation systems generally should not be used
to apply sludge to forages  or to row crops during  the
growing season, although a  light application to the stub-
ble of a forage  crop following a harvest is acceptable.
The adherence of sludge to plant vegetation can have
a detrimental effect on  crop yields by reducing  photo-
synthesis. In addition, spray irrigation tends to increase
the potential for odor problems and reduces the aesthet-
ics at the application site,  both of which can lead to
public acceptability problems.

Liquid sewage sludge can also be injected below the soil
surface, and injection generally is the preferred method
when gaining public acceptance. Available  equipment
includes  tractor-drawn   tank wagons  with  injection
shanks (originally developed for liquid animal manures)
and tank trucks fitted with  flotation tires and injection
shanks (developed for sludge application). Both types of
equipment minimize  odor problems and  reduce ammo-
nia volatilization by immediate mixing  of soil and sludge.
Sludge can be injected  into soils with up to  12 percent
slopes. Injection can be used either  before  planting or
after harvesting most crops  but is likely to be unaccept-
able for forages  and sod production. Some injection
                                    shanks can damage the sod or forage stand and leave
                                    deep ruts in the field. Equipment with specialized injec-
                                    tion shanks has been developed that will not damage
                                    the growth of forage and sod crops.

                                    Dewatered sewage sludge can be applied to cropland
                                    by equipment similar to that used for applying animal
                                    manures, but more sophisticated equipment has  been
                                    developed with  high flotation tires and improved appli-
                                    cation  design.  Typically, the dewatered  sludge will be
                                    surface-applied and then  incorporated  by plowing or
                                    another form of tillage.  Incorporation, however, is not
                                    used when dewatered sludge is applied to growing for-
                                    ages or  to  minimum- or  no-till land. Sewage sludge
                                    application  methods, some of which  can be used to
                                    meet Part 503  vector attraction reduction requirements
                                    (i.e.,  incorporation and  injection),  are  discussed in
                                    greater detail in Chapter 14.

                                    A number of agricultural land application programs using
                                    private farmland have found that soil compaction  is an
                                    important concern of farmers (Jacobs  et al., 1993).
                                    Therefore, care should be taken to manage the applica-
                                    tion equipment and methods (e.g.,  use  wide-flotation
                                    tires, deep till the staging area  following application) to
                                    prevent soil compaction  (Jacobs et al., 1993).
                                                      66

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Table 7-2.  General Guide to Months Available for Sewage Sludge Application for Different Crops in North Central States3

                                                                                            Small Grains'3

                                                       Cotton0
Month
                       Corn
                                      Soybeans
              Forages
                                                                                      Winter
Spring
January
February
March
April
May
June
July
August
September
October
November
December
Se
S
S/l
S/l
P, S/l
c
c
c
c
H, S/l
S/l
S
S
S
S/l
S/l
P, S/l
P, S/l
c
c
H, S/l
S/l
S/l
S
S/l
S/l
S/l
P, S/l
c
c
c
c
c
S/l
S/l
S/l
S
S
S
c
c
H, S
H, S
H, S
S
H, S
S
S
C
C
c
c
c
c
H, S/l
S/l
S/l
P, S/l
C
C
S
S
S/l
P, S/l
c
c
H, S/l
S/l
S/l
S/l
S/l
S
 Application may not be allowed due to frozen, flooded, or snow-covered soils.
b Wheat, barley, oats, or rye.
c Cotton, only grown south of southern Missouri.
d Established legumes (alfalfa, clover, trefoil, etc.), grass (orchard grass, timothy, brome, reed canary grass, etc.), or legume-grass mixture.
e S = surface application
 S/l = surface/incorporation application
 C = growing crop present; application would damage crop
 P = crop planted; land not available until after harvest
 H = after crop harvested, land is available again; for forages (e.g., legumes and grass), availability is limited and application must be light
     so regrowth is not suffocated
On arid rangelands, it is important to minimize the dis-
turbance of the soil surface and existing perennial plant
cover. Examples of sewage sludge  application to ran-
geland are shown in Table 7-1. Carlile et al. describe the
following application method as one that can be used for
arid rangelands:1
• Shred brush species with an agricultural shredder at a
  height that does not disturb underlying grass vegetation.
• Apply the sewage sludge uniformly over the soil surface
  with a tractor-drawn agricultural manure spreader.
• Pass over the land with  a range dyker and roller to
  make small pits and slits in the soil without  signifi-
  cantly disturbing the  grass cover.

7.3.2  Scheduling

The timing of sewage sludge land applications must be
scheduled around the tillage, planting, and harvesting
operations for the crops  grown  and also can be influ-
enced by  crop, climate,  and  soil  properties. Sewage
sludge cannot  be applied during periods of inclement
weather. Table 7-2 presents a general guide regarding
when surface and subsurface applications of sludge are
possible  for  crops in the North Central States.  Local
land-grant universities, extension personnel,  or others
 Carlile, B.L., R.E. Sosebee, B.B. Wester, and R. Zartman. Beneficial use
 of biosolids on arid and semi-arid rangeland. Draft report.
with agronomic expertise can provide similar information
for each state or locality.

Under the Part 503  regulation,  application of sewage
sludge  to agricultural land that is  flooded, frozen, or
snow-covered  is not  prohibited,  but the applier must
ensure that no sludge enters wetlands or surface waters
(except as allowed in a Clean Water Act Section 402 or
404 permit).  Soil moisture is  a major consideration af-
fecting the timing of sludge application.  Traffic on  wet
soils during or immediately following heavy rainfalls may
result in compaction and may leave deep ruts in the soil,
making  crop production  difficult and  reducing  crop
yields. Muddy soils also make vehicle operation difficult
and can create public nuisances by carrying mud out of
the field and  onto roadways.

Split applications of sewage sludge  may be required for
rates of liquid sludge in excess of 4 to 7 t/ha (2 to 3 dry
T/ac), depending on the percent solids content.  Split
application involves more than one  application, each at
a relatively low rate, to attain a higher total rate, when
the soil cannot receive the volume of the higher rate at
one time. For example, if a sludge contains 4 percent
solids, the volume of sludge applied at a rate of 11 t/ha
(5 dry  T/ac)  is  approximately  114,000  L/ha  (30,000
gal/ac, or about 1.1  acre inch [ac-in]). Application rates
much above 0.3 ac-in at  one time will likely result in
runoff or ponding, depending on soil conditions (e.g.,
infiltration  rate,  water-holding capacity) and  slopes.
                                                      67

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Thus, if rates such as 1.1 ac-in are desired, three or four
separate applications will probably be needed.

Subsurface injection will minimize runoff from all soils
and can be used on greater slopes. Injection application
rates in one pass, however, are not much greater than
rates with surface application. Injection should be made
perpendicular to slopes to avoid having liquid sludge run
downhill along the injection slits and pond at the bottom
of the slopes. As with surface application, the drier the
soil, the  more liquid it will be able to absorb, thereby
minimizing any movement downslope.

7.3.3   Storage

Storage facilities are required to hold sewage sludge
during  periods of inclement weather, equipment break-
down, frozen or snow-covered ground, or when land is
unavailable due to growth  of a  crop. Liquid  sewage
sludge can be stored in digesters, tanks, lagoons, or
drying  beds; dewatered  sewage sludge can be stock-
piled.  Volume  requirements will depend on individual
systems and  climate and  can be estimated  from the
following data:

• Sewage sludge volume and physical characteristics

• Climatic data

• Cropping data

Chapter 14 contains additional information on  evaluat-
ing sludge storage needs.

Some states specify climatic restrictions when sewage
sludge applications are prohibited  (e.g., on days when
more  than 2.5 mm  [0.1  in.]  of rainfall occurs).  For a
specific site, the average number of days in each month
with these or other weather conditions can be obtained
from the National Climatic Center,  NOAA,  Asheville,
North Carolina 28801, or from local sources.

Except for forages, sewage sludge application to crop-
land usually is limited to those months of the year when
a crop is not present. The application schedule shown
in Table 7-2 is a general guide for common crops in the
North Central  States; similar information can be ob-
tained  for other states, as discussed in Section  7.3.2.
The availability of sites used to grow several  different
crops will help facilitate the application of sewage sludge
throughout the year.  For example, a number  of fields
containing forages, corn, and winter wheat would allow
sludge application during nearly all months of the year.

7.4   Determining Sewage Sludge
      Application Rates for
      Agricultural Sites

Sewage  sludge application rates  are calculated  from
data on sludge composition, soil test information, N and
P fertilizer needs of the crop grown, and concentrations
of trace elements. In essence, this approach views sew-
age  sludge  as a substitute  for conventional  N or P
fertilizers in crop production.  The number of years that
sewage sludge application may be  limited, based on
Part 503 cumulative pollutant loading rate limits for met-
als, is discussed below in Section 7.4.4.3.

The  general approach for determining sewage sludge
application rates on agricultural cropland can be sum-
marized as follows:

• Nutrient requirements for the crop selected are based
  on yield level and soil test data. If sewage sludge has
  been applied in previous years,  fertilizer  recommen-
  dations  are corrected for carry-over of nutrients
  added by previous sludge  additions.

• Annual sewage sludge application rates  are calcu-
  lated based on N crop  needs, P crop needs, and Part
  503  annual pollutant loading rate limits, where appli-
  cable (bagged sludge).

• Supplemental fertilizer is determined from N, P, and
  K  needed by the  crop and amounts of N, P, and K
  provided by sewage sludge application.

• Sewage sludge applications are terminated  when a Part
  503 cumulative pollutant loading rate limit is reached if
  applicable  (see Section 7.4.4.3 and Chapter 3).

The  majority of sewage  sludge contains roughly equal
amounts of total N and P, while crop requirements for N
are generally two to five  times greater than  those for P.
A conservative approach  for determining annual sewage
sludge application rates would involve applying sewage
sludge to meet the P rather than N needs of the crop.
Some  states require this approach, particularly when
soil fertility test levels for  P are high. With this approach,
farmers would need to supplement sludge  N additions
with  N  fertilizer to achieve the expected crop yield.

7.4.1  Part 503 Agronomic Rate for N and
       Pollutant Limits for Metals

The  Part 503 rule requires that sewage sludge be land
applied at a  rate that is equal to or less than the agro-
nomic rate for N at the application site (i.e., the rate that
will provide the amount of N needed by  the  crop  or
vegetation while minimizing the amount of N  that passes
through the  root zone and enters the ground water).
Additional Part 503 requirements include:

• Sewage sludge cannot be land applied  unless the
  trace element (metal) concentrations in  the  sludge
  are below the Part 503 ceiling concentrations.

• The  sewage sludge must meet either (1) the pollutant
  concentration limits specified in Table 3 of Part 503 or
  (2) the  Part 503 cumulative  pollutant loading rate
  (CPLR) limits for bulk  sewage sludge or the annual
  pollutant loading rate (APLR) limits for bagged sewage
                                                  68

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  sludge (see Chapter 3). If the sewage sludge meets
  the pollutant concentration limits or APLR limits, Part
  503 does not require metal loadings to be tracked.

• The sewage sludge must also meet required Part 503
  pathogen reduction alternatives and vector attraction
  reduction options (see  Chapter 3).

Generally, the agronomic rate is the limiting factor re-
garding application rates for sewage sludge rather than
Part 503 pollutant limits. Only when a  CPLR limit is
being met and the cumulative loading rate at a site is
approaching the CPLR limit will the Part 503 pollutant
limits become the limiting factor for the sewage sludge
application  rate. Section 7.4.4.3 discusses how to cal-
culate sewage sludge application rates  based on the
CPLRs. Because the Part 503 rule requires that the
maximum annual application rates for bagged sewage
sludge,  based on APLRs, be clearly marked on each
bag, calculation of the APLR is not covered here.

The general  approach for  calculating sewage sludge
application  rates in this manual requires  developing as
accurate a  mass  balance for N in the sewage sludge
and soil-crop system as possible. Equations required for
calculating  a N  mass balance are  relatively simple;
choosing reasonable input values for calculations, how-
ever, is  more challenging. For initial calculations, "typi-
cal" and "suggested" values for all necessary parameters
are provided in tables throughout the manual. Site-specific
data or the  best judgement of individuals familiar with the
N  dynamics of the soil-crop system at the site should
always be used in preference to "typical" values. Particu-
larly for  large-scale  projects, laboratory  mineralization
studies should be considered (see Chapter 13),  using
samples of the actual  sewage sludge to be applied and
soil materials from the site, because application rate cal-
culations are quite sensitive to the assumed annual N
mineralization percentage  used.

7.4.2   Crop Selection and Nutrient
       Requirements

The crops grown in an area will influence the scheduling
and methods of sewage sludge application. Utilizing the
cropping systems already present will usually be advan-
tageous, since these  crops have  evolved because of
local soil, climatic, and economic conditions. Since sew-
age sludge applications typically are limited by the N
requirements of the  crop, high N-use crops, such as
forages, corn, and soybeans, will minimize the amount
of land  needed and the  costs associated  with sludge
transportation and  application.  However,  applying
sludge to meet N needs of crops will add  excess P, and
eventually  rates  may need to be reduced  to manage
sludge P additions. Therefore, not only is it good prac-
tice to use fields with a mixture of crops, but the prudent
manager of a land application program will continue to
identify additional land areas that can be held in reserve.
Fertilizer recommendations for crops are based on the
nutrients needed to achieve the desired yield of the crop
to be grown and the capacity of the soil to provide the
recommended plant-available nutrients. The amounts of
fertilizer N, P, and K required to attain a given crop yield
have been  determined experimentally for numerous
soils in each region of the United States. Crop response
to fertilizer nutrients added has been related to soil test
levels for P, K, Mg, and several  of the essential  trace
elements  (Zn, Cu, Fe,  Mn). Accurate measurement of
plant-available N  in soil is difficult and also dependent
on climate. As a result,  fertilizer N recommendations for
a particular locality are  usually developed using a com-
bination of (1) guidelines developed by State Agricultural
Experiment  Stations and the Cooperative Extension
Service, based on historical experience with crop yields
on different soil types using different management prac-
tices; (2) soil test data; and (3) estimates of residual N
carryover from previous applications of sewage sludge,
animal manures, or nitrogen-fixing crops, such as alfalfa
and soybeans.

As an illustration of the  general approach used to deter-
mine nutrient needs, typical relationships between yield
level, nitrogen required, soil test levels for plant-avail-
able P and K, and fertilizer requirements for P and  K are
shown in Tables 7-3 through 7-6 for various crops  in the
Midwest. The amounts of supplemental P and K needed
by crops increase as the yield level increases for a fixed
range of existing plant-available P  and K in the soil.
Conversely, fertilizer needs decrease at a specific yield
level as soil test levels  for P and K increase.

Data such as that presented in Table 7-7 can be used
to estimate the amount of plant-available N that will be
mineralized  from  sludge organic N applied initially and
from organic N estimated to be remaining from previous
sewage sludge applications. These estimates can then
be used to adjust the fertilizer N recommendations for
the crops to be grown. As has been discussed, however,
the amounts of residual organic N from previous sludge
applications that may be mineralized depend on  many
factors. Thus, guidance as to how to best estimate  these
quantities of mineralizable N, as well as information on
fertilizer recommendations, should be obtained from the
Agricultural Experiment Stations and Extension Service
of land-grant universities.

7.4.3   Calculating Residual N, P, and K

When sewage sludge is applied to soil each year, the N,
P, and  K added in previous years that are not taken up
by crops can  be  partially available  during  the current
cropping season. Sewage sludge applied  at a rate  to
meet the  N needs of a crop typically will  result  in in-
creased  soil P levels. Application of sewage sludge
containing high K levels could increase soil K, although
                                                   69

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Table 7-3. Representative
Fertilizer Recommendations for Corn and Grain Sorghum in the
Midwest

Fertilizer P (P2Os) and K (foO) Recommended for Soil
Yield
(Metric tons/ha)
6.7-7.4

7.4-8.4

8.4-10.1

10.1-11.8

11.8-13.4

Nitrogen To
Be Applied
(kg/ha)
134

157

190

224

258

Fertilizer

P (P205):
K (K20):
P (P205):
K (K20):
P (P205):
K (K20):
P (P205):
K (K20):
P (P205):
K (K20):
Very Low

49 (113)
93 (112)
54 (1 23)
112 (135)
59 (1 36)
1 40 (1 69)
64 (1 46)
1 67 (201 )
74 (1 69)
186(224)
Low
(kg/ha)
35 (80)
65 (78)
39 (90)
84 (101)
45 (103)
112(135)
49 (113)
130 (157)
59 (136)
Medium

25 (56)
47 (57)
29 (67)
56 (67)
29 (67)
65 (78)
35 (80)
84 (101)
39 (90)
149(179) 112(135)
High

1 5 (33)
28 (34)
1 5 (33)
28 (34)
20 (46)
37 (45)
25 (56)
56 (67)
25 (56)
74 (89)

Fertility* *
Very High

0
0
0
0
4(10)
0
4(10)
0
4(10)
0
* Soil fertility test levels are as follows:
Soil Test
Very low
Low
Medium
High
Very high
f Amounts of P2O5 and K2O
kg/P/ha
0 to 11
1 2 to 22
23 to 33
34 to 77
78+
are shown in






parentheses.
kg/K/ha
0 to 88
89 to 165
166 to 230
231 to 330
331 +





















1 kg/ha of fertilizer = 0.89 Ib/ac
1 metric ton/ha of crop yield = 15.3 bu/ac
Table 7-4. Representative
Yield
(Metric tons/ha)
2.0-2.7

2.7-3.4

3.4-4.0

4.0-4.7

>4.7

Fertilizer Recommendations for Soybeans in
Nitrogen To
Be Applied
(kg/ha)
157

196

235

274

336

Fertilizer

P (P205):
K (K2O):
P (P205):
K (K20):
P (P205):
K (K2O):
P (P205):
K (K20):
P (P205):
K (K2O):
Fertilizer
Very Low

29 (67)
99 (119)
39 (90)
112(135)
49(113)
140 (169)
59 (1 36)
167(201)
59 (1 36)
186 (224)
the Midwest



P (P2Os) and K (faO) Recommended for Soil Fertility* t
Low
(kg/ha)
25 (56)
74 (84)
35 (80)
84(101)
84(101)
112 (135)
49 (113)
1 40 (1 69)
49 (113)
158 (190)
Medium

20 (46)
47 (57)
25 (56)
56 (67)
35 (80)
84 (101)
39 (90)
112(135)
39 (90)
121 (146)
High

1 5 (33)
37 (45)
1 5 (33)
56 (67)
20 (46)
56 (67)
25 (56)
74 (89)
25 (56)
74 (89)
Very High

0
0
0
0
0
0
10 (23)
0
10 (23)
19 (23)
* See Table 7-3 for definition of soil fertility test levels.
f Amounts of P2O5 and K2O shown in parentheses.
 1 kg/ha of fertilizer = 0.89 Ib/ac
 1 metric ton/ha of crop yield = 15.3 bu/ac.
                                                                70

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Table 7-5.  Representative Fertilizer Recommendations for Small Grains in the Midwest

                                                            Fertilizer P (P2Os) and K (faO) Recommended for Soil Fertility*t
Yield
(Metric tons/ha)
Nitrogen To
Be Applied
(kg/ha)
Fertilizer
Very Low
Low
Medium
High
Very High
(kg/ha)
WR:1. 9-2.8*
WR:2.8-3.4
WR:3.4-4.0
WR:4.0-4.6
WR:>4.6
62
73
84
95
106
P (P.O.):
P (P.O.):
P (P.O.):
P (P.O.):
P (P.O.):
45 (1 03)
59 (1 36)
59 (1 36)
69 (1 59)
69 (1 59)
29 (67)
45 (103)
45 (103)
54(123)
54(123)
15(33)
29 (67)
29 (67)
45(103)
45(103)
1 0 (23)
1 5 (33)
1 5 (33)
29 (67)
29 (67)
1 0 (23)
10 (23)
10 (23)
10(23)
10(23)
* See Table 7-3 for definition of soil fertility test levels.
f Amounts of P2O5 and K2O are shown in parentheses.
# WR = Wheat and Rye.
1 kg/ha of fertilizer = 0.89 Ib/ac.
 1 metric ton/ha  of crop yield = 14.3 bu/ac for wheat and rye.
Table 7-6.  Representative Fertilizer Recommendations for Forages in the Midwest

                                                           Fertilizer P (P2Os) and K (foO) Recommended for Soil Fertility* t
Yield
(Metric tons/ha)
< 1.8

2.2-2.7

>2.7

Nitrogen To
Be Applied
(kg/ha)
112

224

390

Fertilizer

P (P.O.):
K (KO):
P (P.O.):
K (KO):
P (P.O.):
K (KO):
Very Low

49 (113)
224 (270)
59 (1 36)
336 (405)
69 (1 59)
448 (540)
Low
(kg/ha)
39 (90)
1 86 (224)
49 (113)
280 (337)
59(136)
392 (472)
Medium

25 (56)
140 (169)
35 (80)
224 (270)
45 (103)
336 (405)
High

15 (33)
74 (89)
25 (56)
1 68 (202)
35 (80)
280 (337)
Very High

10 (23)
0
20 (46)
112(135)
25 (56)
224 (270)
* See Table 7-3 for definition of soil fertility test levels.
f Amounts of P2O5 and K2O are shown in parentheses.
  1 kg/ha - 0.89 Ib/ac
 1 mt/ha - 0.45 T/ac
                                                             71

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Table 7-7. Estimated Mineralization Rates (Kmin) for Different Sewage Sludges (Adapted From Sommers et al, 1981)

                                         Fraction (Kmin)* of Organic N Mineralized From the Following Sludges:
Time After Sewage Sludge
Application (Years)
0-1
1-2
2-3
3-4
Unstabilized Primary
and Waste
0.40
0.20
0.10
0.05
Aerobically
Digested
0.30
0.15
0.08
0.04
Anaerobically
Digested
0.20
0.10
0.05
-
Composted
0.10
0.05
_t
-
* Fraction of the sludge organic N (Org-N) initially applied, or remaining in the soil, that will be mineralized during the time interval shown. K,™
 values are provided as examples only and may be quite different for different sewage sludges, soils, and climates. Therefore, site-specific
 data, or the  best judgement of individuals familiar with N dynamics in the soil-plant system, should always be used in preference to these
 suggested Kmin values.
t
 Once the mineralization rate becomes less than 3% (i.e., 0.03), no net gain of PAN above that normally obtained from the mineralization of
 soil organic matter is expected. Therefore, additional credits for residual sludge N do not need to be calculated.
agronomic rates (for N) of sewage sludge usually will
add K at levels less than crop needs.

The contribution of residual N carryover to plant-avail-
able  N  can  be significant when sewage sludge  is
applied  each year. Although the largest percentage  of
mineralizable organic N is converted to inorganic  N
during the year that the sludge is applied, the contin-
ued decomposition of organic N in succeeding years
can provide some additional plant-available N for crop
growth.   The  amount of  N mineralized  in  sludge-
treated  soils is dependent on the type of sludge treat-
ment processes used, the ratio of inorganic to organic
N in  the sludge, and the amount of organic N applied
in previous years.

The approach proposed for evaluating residual N, P, and
K from previous sewage sludge applications is as follows:

• P and K—Assume that 50 percent of the P and 100
  percent of the K applied are available for plant uptake
  in the year of application. These quantities of P and
  K can be credited against fertilizer recommendations.
  Any P and K in excess of plant needs will contribute
  to  soil fertility levels that can be regularly monitored
  and taken into account when  determining  fertilizer
  recommendations in succeeding years.

• N—Plant-available N (PAN) that may be mineralized
  from  residual sludge organic  N can sometimes be
  estimated by using soil tests (see Chapter 6). How-
  ever,  estimating PAN by using mineralization factors
  recommended  by  land-grant universities or  state
  regulatory  agencies is  more common. The largest
  portion  of organic N in sewage  sludge is converted
  to  inorganic N during the first year after application
  to  the soil. After the first year, the  amount of N min-
  eralization decreases each year until it stabilizes  at
  about 3 percent, a rate  often observed for stable
  organic N fractions  in soils. Once the 3 percent level
  has been reached,  any additional  quantities  of PAN
  will not be  significant  enough to credit  against the
  fertilizer N recommendation.
  Table 7-7 suggests a decay sequence where the
  amount of N mineralized decreases by about 50 per-
  cent each year until the 3 percent rate is reached.
  Using anaerobically digested sewage sludge as an
  example, if 20  percent of the organic N was miner-
  alized during the first year, the amounts released  in
  years 2 and 3  would be 10 and 5 percent, respec-
  tively, of the organic N  remaining (see Table 7-7).
  After year 3, the mineralization rate decreases to the
  background rate for soil  organic matter, so no  addi-
  tional credit for residual sludge organic N is calcu-
  lated. This decay sequence may or may not be the
  most appropriate one to use for your state or location,
  but it will be used to illustrate how mineralizable N can
  be calculated to estimate PAN credits.

7.4.4  Calculation of Annual Application Rates

Recommended annual rates of sewage sludge applica-
tion on cropland are based on the N  or P requirements
of the crop grown, the N and P levels in the sludge, and
the metal  concentrations in the sludge for which pollut-
ant limits  have been  set in the Part 503 rule.  As dis-
cussed in  the  previous   section,   the fertilizer  N
recommendation  for the crop and yield level  expected
should be corrected for  plant-available  N mineralized
from  prior sludge additions. The  basic approach for
determining annual application rates of sewage sludge
involves using data on sewage sludge composition  to
calculate maximum potential application rates based on
(1) crop N requirements, (2) crop P requirements, and
(3) Part 503 pollutant limits. In most cases, the actual
application rate will be selected from the following two
possibilities:

• The annual agronomic rate can be utilized to  provide
  recommended N needs until the Part 503 CPLR limits
  for  metals  are  reached,  unless the sewage sludge
  meets the pollutant concentration limits in Table 3  of
  Part 503, in which case cumulative metal loadings do
  not need to be tracked. (In some cases, this approach
  may result in the accumulation of excess P in the soil,
                                                    72

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  which  can increase the  potential  for  P entering
  streams and lakes through surface erosion).

• In some states, the annual rate may be  limited to a
  rate where sludge P is  equal to fertilizer P  recom-
  mendations or the P removed by the crop. Nitrogen
  may be applied at less than the  crop N need. This P
  rate could be followed as  long as it did  not exceed
  the agronomic N  rate or any Section 503 pollutant
  loading limits for metals.

Another possibility is that the  metals loadings at the site
are approaching a Part 503 CPLR limit, which may result
in an application rate that is less than the crop's N or P
needs (i.e., sewage sludges that do not meet the Part
503 pollutant concentration limits for metals). Reaching
a CPLR limit terminates CPLR sewage sludge applica-
tion to land,  in which case other options, such as incin-
eration or surface disposal, are likely to be more feasible.
Currently, however, a majority of sewage sludge in the
United States can meet Part 503's pollutant concentration
limits. Thus, the nutrient requirements of a crop will likely
be the limiting factor  rather than Part 503 pollutant limits.

The following section summarizes the basic calculations
used to  determine  sewage  sludge application rates
based on N (Section 7.4.4.1) and P (Section 7.4.4.2),
and the  estimated  project life based  on CPLR limits
(Section  7.4.4.3). The  design example  (Section 7.5)
provides additional illustrations of these calculations.

 7.4.4.1   Calculation Based on Nitrogen

As discussed previously, not all the N in sewage sludge
is immediately available to plants, since some is present
as organic N (Org-N), i.e., in microbial cell tissue and
other organic compounds.  Organic N must be decom-
posed into mineral,  or inorganic forms, such as NH4-N
and NO3-N,  before it can be used by plants. Therefore,
the availability of Org-N for plants depends on the mi-
crobial breakdown of organic materials (e.g., sewage
sludge, animal manure, crop residues, soil organic mat-
ter, etc.) in soils.

The proportion of sludge Org-N that is mineralized in a
soil depends on various factors which  influence immo-
bilization and  mineralization  of  organic  forms of  N
(Bartholomew, 1965; Harmsen and van Schreven, 1955;
Smith and  Peterson,  1982;  Sommers and Giordano,
1984).  Schemes for estimating  the  amount of miner-
alizable N from organic fertilizers, like animal manure
and sewage sludge, have been suggested (Pratt et al.,
1973; Powers, 1975; Smith and Peterson, 1982;  USDA,
1979; USEPA,  1975, 1983).

Estimates of mineralizable N using decay (decomposi-
tion) series are not precise, however, since the actual N
availability will depend  on  organic N composition, de-
gree of treatment  or stabilization of the sewage sludge
before land application, climate, soil conditions, and other
factors. Another approach to predicting N availability is
to model (mathematically)  the transformations of N in
the soil. However, modeling has not yet been found to
be accurate enough to give more than a general esti-
mate of N availability (Schepers and Fox, 1989). Never-
theless,  management  strategies   must   attempt  to
balance the addition  of plant-available N, provided  by
land application of organic materials like sewage sludge,
with the needs of the crop. Otherwise, excess NOa-N
can be leached into groundwater by precipitation or poor
management of irrigation water (Keeney, 1989).

The plant-available N, or  PAN,  provided  by  sewage
sludge is influenced  by several factors.  Initially, the
quantity of total N in the sludge and the concentrations
of NO3-N, NH4-N and Org-N (which  together make  up
the total N) must be determined. Commonly, the concen-
tration of Org-N is estimated by subtracting the concen-
tration  of NO3-N and NH4-N  from the  total N, i.e.,
Org-N =  total N - (NO3-N  + NH4-N). The  NH4-N and
NO3-N added by sludge is considered to be  as available
for plants to utilize as NH4-N  and NO3-N added by fertilizer
salts or other sources of these mineral forms of N.

The availability of sewage sludge Org-N will depend  on
the type of treatment or stabilization the sludge received.
Anaerobically digested sludge normally will have high
levels of NH4-N and very little NO3-N, while aerobically
digested  sludge will  have  higher levels  of NOa-N  by
comparison. Composting and anaerobic digestion ac-
complishes greater stabilization of organic carbon com-
pounds than aerobic digestion or waste activation. The
greater the  stabilization, the slower the rate of minerali-
zation of carbon compounds (containing Org-N from the
sewage sludge) and  the lower the amounts of  Org-N
released for plant uptake.

Differences  between  these various types of sewage
sludges can be seen in Table 7-7 which shows average
mineralization rates for the first through fourth year fol-
lowing  a sludge application (Sommers et al.,  1981).
These values, however, are averages only and can vary
significantly due to differences in the characteristics of
the sewage sludge, soil, and climate (i.e., temperature
and rainfall). For example, assuming adequate moisture
is available for microbial decomposition,  increases in
temperature will increase the activity of microorganisms.
Therefore, mineralization rates are typically higher in the
summer months than  in the winter months and higher in
the southern U.S. than in the northern states. Because
of these  differences,  calculating  the agronomic rate
should be done on  a site-specific basis. Using minerali-
zation factors recommended by state regulatory  agen-
cies and land-grant   universities  that are based  on
decomposition or N  mineralization studies, computer
simulations  that estimate  decomposition, or  docu-
mented field experience is  advised.
                                                  73

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The amount of PAN also will be affected by the amount
of NH4-N lost by volatilization of ammonia (NH3). Ammo-
nia volatilization losses, when animal manure orsewage
sludge is applied to land, have long been recognized
(Adriano et  al., 1974; Beauchamp et al., 1978, 1982;
Brunke  et al., 1988; Christensen,  1986;  Db'hler and
Wiechmann, 1988;  Hall and Ryden, 1986; Hoff et al.,
1981; Lauer et al., 1976; Rank et al., 1988; Reddy et al.,
1979; Terman, 1979; Vallis et al., 1982). Accurately es-
timating the  extent of this loss is difficult, however, given
the variability in weather conditions that largely dictate
how fast volatilization will occur.

In addition to weather conditions, the method of sewage
sludge application,  the length  of time sewage sludge
remains on  the soil surface  prior to incorporation, and
the pH (e.g., lime content) of the sewage sludge also will
influence the potential for volatilization losses. High pH
in sewage sludge or soil will encourage the conversion
of NH4-N to NH3, resulting in a N loss to the atmosphere.
The longer the sludge remains on the soil surface and
is subjected to drying conditions, the greater the risk of
NH3 volatilization losses.

With injection of liquid sewage  sludge, little NH3 should
be lost  to volatilization,  except  possibly on  coarsely
textured  (sandy) soils. Volatilization losses, however,
should be considered for surface-applied liquid sewage
sludge that is later incorporated and for surface-applied
dewatered sewage  sludge that is  later incorporated or
remains on the surface. This N  loss needs to be consid-
ered,  or the amount of PAN reported to the farmer as
being applied will be overestimated.

Volatilization losses of NH4-N from animal manure also
are  of interest in many states, and guidance  often is
provided by  state land-grant universities; thus,  applica-
tors of sewage sludge may want to seek similar guid-
ance to  estimate loss of NH4-N as  NH3 during sewage
sludge application. In addition,  several states (e.g., Vir-
ginia, Washington) have developed specific guidance on
NH3  volatilization from sewage sludge that takes into
account such  factors as lime  content of the sewage
sludge and the length of time  sewage sludge remains
on the soil surface before it is incorporated.

For these reasons, Table 7-8 can serve as guidance for
estimating NH4-N losses as NH3. As indicated earlier,
these volatilization factors may not be the most appro-
priate for a specific site, so values should  be  obtained
from state regulatory agencies or state land-grant uni-
versities that are more site-specific for a particular location.

The inability to accurately estimate volatilization losses,
combined with the difficulty of estimating the amount of
mineralizable N, means that regulators need to remain
flexible  regarding the methods used to estimate  the
amount of PAN per dry ton of sewage sludge.
Table 7-8.  Volatilization Losses of NH4-N as NH3
Sewage Sludge Type and
Application Method
NH3 Volatilization
   Factor, Kvo,
Liquid and surface applied

Liquid and injected into the soil

Dewatered and surface applied
     0.50

      1.0

     0.50
With these factors in mind, a number of steps can be used
to determine the agronomic  rate (i.e., based on  PAN).
These steps are summarized below and also are shown
on Worksheets 1 and 2 (see Figures 7-1 and 7-2):

1. Determine the fertilizer N recommendation for the
   crop and yield level anticipated on the soil that is to
   receive  the  sewage  sludge  application.   (Since
   legume  crops can fix their own N, they usually will
   not  have a  N fertilizer recommendation. Legume
   crops,  however,  will  utilize N  that  is applied  as
   fertilizer, manure, or sewage sludge, so  N crop
   removal values  can be used to estimate the  N
   requirement for these crops.)
2. Subtract anticipated N credits from the recommended
   fertilizer N rate, i.e., for other sources of N such as the
   following:

   a. Residual N  left by a previous legume  crop (leg-
     umes have the ability to fix  N from the  air, and
     varying levels  of N will be  left in  the  soil when
     legumes are replaced by another crop; land-grant
     universities  can provide  appropriate credits that
     should be used for a particular site).

   b. Any N that  has already  been applied  or will be
     applied during the growth of the crop by fertilizer,
     manure, or other sources that will be readily avail-
     able for plants  to use.
   c. Any N that is anticipated to be added by irriga-
     tion water that will be applied during the growth
     of the crop.

   d. Any residual Org-N remaining from previous sew-
     age sludge applications. As previously discussed,
     Table 7-7 lists  average mineralization  rates,  but
     more sewage sludge-specific and site-specific infor-
     mation should be used when available. Experience
     over  time has shown that when agronomic rates
     of sewage sludge are used,  no additional PAN
     above that  normally obtained from soil  organic
     matter turnover is expected after 3-4 years. There-
     fore,  calculating PAN credits for a sludge  applica-
     tion beyond the third year is not recommended,
     since these quantities are negligible. The chart in
     Worksheet 1  and the mineralization factors in Ta-
     ble 7-7 can be used to estimate the PAN for years
     2  and 3.  An example calculation  is included  in
     Worksheet 1.
                                                   74

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                                               Worksheet 1
                            Calculations for Determining PAN Mineralized From
                       Residual Organic N Applied as Sewage  Sludge in Previous Years
    Residual N from previously-applied sewage sludge that will be mineralized and released as plant-available
    N (PAN) must be accounted for as part of the overall budget for PAN, when determining the agronomic
    N rate for sewage sludge (i.e., Worksheet 2).  This residual N credit can be estimated for some sites using
    soil nitrate tests, but more commonly the PAN credit is estimated by multiplying a mineralization factor
    (K^) times the amount of sludge organic N (Org-N) still remaining in the  soil one and two years after
    sludge has been applied.

    Instructions: Complete a separate chart for each year that sewage sludge was previously-applied.  Studies
           and experience have shown that any residual sludge Org-N remaining 2-3 years after application
           will not contribute significantly to PAN normally mineralized from  soil organic matter
           decomposition. Therefore, calculating PAN credits beyond the third year is usually not necessary.
           To determine total mineralized Org-N released as PAN, sum the values under Mineralized Org-N
           (Column D) for the "Growing Season Year" for which you are planning a new sludge application
           to estimate the residual N credit for sludge applications the previous two years.
A. Year of
Growing Season1
0-1 (sludge
applied)
1-2 (one year
later)
2-3 (two years
later)
B. Starting Org-N2
(Ib/acre)



C. Mineralization
Rate3 (K,™)



D. Mineralized
Org-N4 or PAN
(Ib/acre)



E. Org-N
Remaining5
(Ib/acre)



      1 Begin with the growing season (i.e., year the crop will be grown) for which sewage sludge was applied
        and continue two more years (i.e., two more growing seasons).
      2 For the first year, this equals the percent Org-N in the sludge times the rate of application. For years
        1-2 and 2-3, this quantity equals the amount of Org-N remaining from the previous year (i.e., column
        E).
      3 The mineralization rate is the fraction of sludge Org-N expected to be released as PAN for the year
        being calculated.  Example mineralization rates can be found in Table 7-7.
      4 Multiply column C times column B and round to the nearest whole pound.
      5 Subtract column D from column B and round to the nearest whole pound.
Figure 7-1.  Determining mineralized PAN from previous sludge applications.
                                                   75

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                                        Worksheet 1 (continued)

                                               Example

   Assume that anaerobically digested sewage sludge with 2.5% Org-N (dry weight basis) was applied at a
   rate of 3 ton/acre for the 1996 growing season. For the 1997 growing season, 2 ton/acre of a sludge
   containing 3.0% Org-N was applied to the same site. For the 1998 growing season, calculate the amount
   of PAN that will be mineralized from the sludge Org-N applied in the previous 2 years.

       In 1996, the sludge Org-N applied  = 2.5 Ib Org-N x 3 ton sludge x 2000 Ib sludge  =  150 Ib Org-N/acre
                                               100 Ib  sludge     acre         ton sludge

       In 1997, the sludge Org-N applied  = 3.0 Ib Org-N x 2 ton sludge  x 2000 Ib sludge  = 120 Ib Org-N/acre
                                               100 Ib  sludge     acre         ton sludge

   Use Worksheet 1 to  calculate the PAN released during the  1998 growing season from the sludge applied
   in 1996 and 1997.
A. Year of
Growing Season
B. Starting Org-
N (Ib/acre)
C. Mineralization
Rate (K^)
D. Mineralized
Org-N (Ib/acre)
E. Org-N
Remaining
(Ib/acre)
1996 Sludge Application
0-1 (1996
Application)
1-2 (1997)
2-3 (1998)
150
120
108
0.20
0.10
0.05
30
12
5
120
108
103
1997 Sludge Application
0-1 (1997
Application)
1-2 (1998)
2-3 (1999)
120
96
86
0.20
0.10
0.05
24
10
4
96
86
82
  To determine the total amount of PAN mineralized in 1998 from sludge applied in 1996 and 1997, add the
  Mineralized Org-N (or PAN) value in the 1998 row under column D for each year's chart (i.e., 5 + 10 =
  15 Ib PAN/acre). Therefore, the total PAN, or mineralized Org-N, from previous sludge applications
  equals 15 Ib/acre.
Figure 7-1. Determining mineralized PAN from previous sludge applications (continued).
                                                     76

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                                                  Worksheet 2
                         Nitrogen Budget Sheet for Determining the Agronomic N Rate
                                         for Sewage Sludge Applications
                                        Symbols and Abbreviations Used

       Org-N = Organic N content of the sewage sludge obtained from analytical testing and determined by
            subtracting (NO3-N + NH4-N) from total N, usually given in percent (%); the resulting
            concentration should be converted to Ib/ton (dry weight basis).
       NH4-N = Ammonium N content of the sewage sludge obtained from analytical testing and usually
            given in percent (%); convert to Ib/ton (d,w. basis).
       NO3-N = Nitrate N content of the sewage sludge obtained from analytical testing and often given in
            mg/kg; convert to Ib/ton (d.w. basis).
       K^n = Mineralization rate for the sewage sludge expressed as a fraction of the sludge Org-N
            expected to be released as PAN  for the year being calculated; example mineralization rates for
            different sewage sludges can be found in Table 7-7.
       Ky,,, = Volatilization factor for estimating the amount of NH4-N remaining after loss to the
            atmosphere as ammonia and expressed as a fraction (e.g., if K^ =  1.0, 100% of the NH4-N is
            retained and contributes to  PAN; if K^  = 0.5, then 0.5 x NH4-N estimates the amount of NH4-N
            contributing to PAN).
       PAN = Plant-available N,  determined by calculating: NO3-N  + Kvol(NH4-N) + K^Org-N)

                                              Helpful Conversions

            mg/kg x 0.002 = Ib/ton        Ib/acrex  1.12 = kg/ha           Ib/ton H- 2 = kg/mt
            % x 20 = Ib/ton               ton/acre x 2.24 = mt/ha         (mt = metric ton = 1000 kg)
  1.  Total N requirement of crop to be grown (obtain information from Cooperative Extension                 	Ib/acre
     Service agricultural agents, USDA-Natural Resource Conservation Service, or other
     agronomy professionals).

  2.  Nitrogen provided from other N sources added or mineralized in the soil
     a.  N from a previous legume crop (legume credit) or green manure crop             	Ib/acre
     b.  N from supplemental fertilizers already, or expected to be, added                	Ib/acre
     c.  N that will be added by irrigation water                                     	Ib/acre
     d.  Estimate of available N from previous sludge applications (from Worksheet 1)       	Ib/acre
     e.  Estimate of available N from a previous manure application (obtain mineralization   	Ib/acre
        factors from land-grant university to calculate similarly as for previous sewage
        sludge applications').
     f.  Soil nitrate test of available N present in soil [this quantity can be substituted        	Ib/acre
        in place of (a + d + e) if lest is conducted properly; do not use this test value if
        estimates for a, d and e are used]

     Total N available from  existing, expected, and  planned sources of N (add a+b+c+d+e or b+c+f)         	Ib/acre

  3.  Loss of available N by  denitrification, immobilization, or NH4+ fixation (check with state regulatory         	Ib/acre
     agency for approval before using this site-specific factor).

  4.  Calculate the adjusted  fertilizer N requirement for the crop to be grown (subtract Total N for (2)          	Ib/acre
     from (1); amount for (3) can be added to this difference, only if (3) is approved for this additional adjustment).


Figure 7-2.  Determining agronomic N rate.
                                                         77

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                                                 Worksheet 2 (continued)

   5.  Determine the PAN/dry ton for the sludge that will be applied                                          ^^_^^ Ib/ton
       [i.e., NOj-N + K,., (NH4-N) + K^. (Org-N) = PAN]

   6.  Calculate the  agronomic N rate of sewage sludge (Divide (4) by (5))                                     	ton/acre

   7.  Convert the rate of sewage sludge in dry tons/acre into gallons/acre, cubic yards/acre, or wet tons/acre,
       since the sludge will be applied to land as a liquid or as a wet cake material.
Figure 7-2.  Determining agronomic N rate (continued).
                                                              78

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  e. Residual organic N remaining from any previous
     animal manure application should be estimated.
     Various decay schemes are used for manure ap-
     plications by land-grant universities, so residual
     N released  from a previous  manure application
     can be estimated in a similar  manner as for sew-
     age sludge  applications (i.e.,  step 2.d).

  f.  The combined residual N  already present in the
     soil or expected to be available  for  crops to use
     can sometimes  be estimated by the soil nitrate
     test (e.g., inorganic N left  from previous fertilizer,
     manure, sludge, etc. applications; or credits given
     for the mineralization of soil  organic matter and
     legume crop residues). The soil nitrate test can
     be used in some states to estimate  quantities of
     NO3-N that may be present from previous fertilizer
     N, manure,  and/or sewage sludge applied and/or
     from mineralization of N from legume crops and
     soil organic matter. But because NO3-N can be
     lost by leaching, the soil nitrate test must be used
     with  care in semi-humid and   humid climates.
     Therefore, guidance should be  obtained from a
     land-grant university for the proper credits to use.

     Note that if  a soil nitrate test  is used to  estimate
     residual N contributions, then estimates for steps
     2.a, 2.d, and 2.e should  not be included  in the
     summation done in step 2 on Worksheet 2.

3.  Add any anticipated N losses due to denitrification,
   immobilization, or  chemical fixation  of  NHJ  by
   micaceous (i.e., mica-containing) clay minerals (use
   only if approved by regulatory agency). Denitri-
   fication [i.e., the loss of NO3-N  as  nitrogen (N2) or
   nitrous oxide (N2O) gases] and  immobilization (i.e.,
   the  loss of NO3-N or NH4-N by incorporation  into
   organic compounds by the soil biology) can occur in
   soils.  For  soils  containing hydrous  mica  clay
   minerals, some NHJ may become fixed within the
   crystal lattices  of these minerals in  spaces  normally
   occupied by K+. If this occurs, NHJ is unavailable for
   plant uptake unless mineral weathering occurs to
   again release the  NHJ.

   The source  of the NO3-N and NH4-N  can be from
   fertilizer,  manure, etc.  as well  as sewage sludge
   applications. Note that if fertilizer recommendations
   are  used which account for  average losses due to
   biological denitrification and immobilization or chemical
   fixation of NHJ, a separate credit  for these processes
   should not be  used for this step. Therefore, adding
   these anticipated  N losses should not be done
   unless  justification  is  provided to the permitting
   authority and approval is received.

4.  Use Worksheet 2 to determine the  adjusted fertilizer
   N rate by subtracting "total N  available from existing,
   anticipated, and planned sources" (Worksheet step
   2) from "total N requirement of crop" (Worksheet step
   1). If a loss of available N by denitrification, immobil-
   ization or NHJ fixation is allowed (i.e., approved by
   the  state regulatory agency), this  anticipated loss
   can  be added to the  difference  obtained when
   subtracting the step 2 total from the step 1 amount
   to obtain a final adjusted fertilizer N rate.

5.  Determine the PAN/dry ton of sewage sludge for the
   first year of application using the following equation:
PAN = N03-N +

where:
                     i (NH4-N) + Kmin (Org-N)
   PAN   = plant-available N in Ib/dry ton sewage
            sludge
   NO3-N = content of nitrate N in sewage sludge
            in Ib/dry ton
   Kvoi    = volatilization factor, or fraction of NhU-N
            not lost as NHs  gas to the atmosphere
   NH4-N = content of ammonium N  in sewage
            sludge in  Ib/dry ton
   Kmin   = mineralization factor, or fraction of
            Org-N converted to PAN
   Org-N  = content of organic N in sewage sludge
            in Ib/dry ton,  estimated by Org. N =
            total N - (NOs-N + NhU-N)

     Example: Assume  liquid,  aerobically digested
     sewage sludge is to  be  incorporated into the soil
     by direct injection (i.e., K^, = 1 .0). The suggested
     mineralization rate in Table 7-7 is K^ = 0.30 for
     the first year. The chemical analysis  of the sludge
     shows N03-N = 1,100 mg/kg, NH4-N = 1.1% and
     total N = 3.4%, all on  a  dry weight  basis, and
     percent dry solids is  4.6%.

   a. First convert  concentrations to Ib/dry ton:

     for N03-N —  1 ,1 00 mg/kg x 0.002 = 2.2, or 2 Ib/ton
     (rounded to nearest whole Ib)

     for  NH4-N — 1 .1% x 20 = 22 Ib/ton

     for total N — 3.4% x 20 = 68  Ib/ton

     for  Org-N —  68 -  (2 + 22) = 44 Ib/ton

   b. Calculate PAN:

     PAN = 2  + 1 .0 (22 Ib/ton) + 0.3 (44 Ib/ton)  =
     2 + 22 + 13 = 37  Ib/ton

6.  Divide the adjusted fertilizer N rate (Ib N/acre from step
   4) by the PAN/dry ton sewage sludge (Ib N/ton from
   step 5) to obtain  the agronomic N rate in dry tons/acre.

     Example: Assume the adjusted  fertilizer N rate
     from step 4  is 130 Ib N/acre and the aerobically
     digested  sewage sludge from the example in step
                                                   79

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     5 above is used to provide crop N needs. What is
     the agronomic N rate?

     Agronomic N rate  = 130 Ib N/acre -^ 37 Ib N/ton
     = 3.5 dry tons/acre

7. This dry ton/acre  rate  can  be  converted  to  wet
   gallons/acre,  since this  is the  form in  which the
   sewage sludge will be applied:

     wet tons/acre = 3.5 dry ton/acre -^ 4.6 dry ton/100
     wet ton (i.e., 4.6% solids) = 76 wet ton/acre

This wet tonnage can then be converted to gallons/acre
by the following conversion:

     76 wet ton/acre x 2,000 Ib/wet ton x
     1 gallon/8.34 Ib = 18,200 gallons/acre

This rate would be equivalent to about 2/3 acre-inch  of
liquid (1 acre-inch = 27,150 gal), too much to apply  in
one application.  Probably 13,000-15,000 gal/acre  is a
maximum  amount that can normally be applied at one
time using injection.

7.4.4.2  Calculation Based on Phosphorus

The majority of P in sewage sludge  is  present as inor-
ganic compounds. While mineralization of organic forms
of P occurs during decomposition  of  sludge organic
matter, inorganic reactions of P are of greater impor-
tance when considering sludge P additions. Because  of
the predominance of inorganic P, therefore, the P con-
tained in sewage sludge is  considered to be about 50
percent as available for plant uptake as the P normally
applied to soils  in commercial fertilizers (e.g., triple su-
perphosphate, diammonium phosphate, etc.). As  pre-
viously discussed, the P fertilizer needs of the crop  to
be grown  are determined from the soil fertility test for
available P and the yield of the crop. The agronomic P
rate of sewage sludge for land application can be deter-
mined by the following equations:

   Agronomic P Rate =  Preq + Avail. P2Os/dry ton

   where:
    req
                    = the P fertilizer recommenda-
                      tion for the harvested crop, or
                      the quantity of P removed by
                      the crop,
   Avail. P2Os       = 0.5 (total P2Os/dry ton)
   Total P2O5/dry ton = %P in sludge x 20 x 2.3*

   *2.3  is the factor to convert Ib P to Ib P2Os (the ra-
   tio of the atomic weights of P2Os:P, i.e.,142:62).

For nearly all sewage sludge, supplemental N fertiliza-
tion will be needed to optimize crop yields (except for
N-fixing legumes) if application rates are based on a
crop's P needs.
                                                      7.4.4.3  Calculation Based on Pollutant
                                                              Limitations

                                                      The literature pertaining to trace element (metal) addi-
                                                      tions to the soil-plant system from sewage sludge ap-
                                                      plications is extensive, and several key references can
                                                      be a source  of more in-depth  discussions (Allaway,
                                                      1977; Berglund  et al.,  1984;  CAST,  1976,  1980;
                                                      Chaney, 1973, 1983a,  1983b, 1984; Chaney and Gior-
                                                      dano, 1977; Davis etal., 1983; L'Hermite and Dehandt-
                                                      schutter,  1981; Lindsay,  1973;  Logan and  Chaney,
                                                      1983; Melsted, 1973; Page et  al.,  1987; Ryan and
                                                      Chaney, 1993; Sommers and  Barbarick,  1986;  U.S.
                                                      EPA, 1974; Walsh et al., 1976).  Potential hazards as-
                                                      sociated with trace element additions have mostly per-
                                                      tained to their accumulation in soils which may (1) lead
                                                      to a  plant toxicity condition  or (2) result in increased
                                                      uptake of trace elements into the food chain.

                                                      As discussed in Chapter 3,  the  pollutant  limits  estab-
                                                      lished in the Part 503 regulation protect human health
                                                      and the  environment from reasonably anticipated ad-
                                                      verse effects of pollutants that may be present in sew-
                                                      age sludge.

                                                      Because most sewage sludges will likely contain pollut-
                                                      ant  concentrations that do  not  exceed the Part 503
                                                      "pollutant concentration limits" (see Chapter 3), pollut-
                                                      ant  loading limits will  not be  a  factor in  determining
                                                      annual sewage sludge application rates for these sew-
                                                      age sludges. For other sewage sludges that have pol-
                                                      lutant concentrations that exceed one or more of the
                                                      Part  503 "pollutant concentration limits," the Part 503
                                                      "cumulative pollutant loading rates" (CPLRs) discussed
                                                      in Chapter 3 and shown in  Table 7-9 must be  met;
                                                      CPLRs could eventually be the limiting factor for annual

                                                      Table 7-9.  Part 503 Cumulative Pollutant Loading Rate
                                                               (CLPR) Limits

                                                                                  Loading Limits
Pollutant
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
kg/ha
41
39
3,000a
1,500
300
17
a
420
100
2,800
Ib/acre
37
35
2,700
1,300
270
15
—
380
90
2,500
                                                       Chromium limits will most likely be deleted from Part 503. The CPLR
                                                       for Mo was deleted from Part 503 effective February 25,
                                                       1994. EPA will reconsider this limit at a later date.
                                                   80

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sewage sludge applications (rather than the agronomic
rate of application).

For sewage sludge meeting Part 503 CPLRs, two equa-
tions are helpful for managing pollutant loadings to soils.
The first equation can be used to estimate the maximum
total  quantity of sewage sludge permitted to be applied
to a soil, based on the CPLR and the pollutant concen-
tration in the sewage sludge being considered:

   Maximum sewage sludge allowed (dry tons/acre) =
   Ib/acre  (CPLR) + 0.002 (ppm pollutant)

   where:

   ppm pollutant = mg of pollutant per kg of dry sew-
   age sludge.

After making this calculation for each of the 10 pollutants
regulated by Part 503, the lowest "total sewage sludge"
value should be used as the maximum quantity of sew-
age sludge allowed to be applied for that particular site.
The  design example in  Section 7.5 shows how  this
equation is used.

A second equation,  also  illustrated in Section  7.5,  can
be used to determine the individual pollutant loading
added by each sewage sludge application rate:

   Ib of pollutant/acre = sludge rate (dry tons/acre) x
   0.002 (ppm pollutant)

A cumulative  record of individual applications is then
kept for each field receiving sewage sludge that is meet-
ing the CPLRs. When the cumulative amount of any one
regulated  pollutant  reaches  its  CPLR,  no additional
CPLR sewage sludge can be applied.

7.4.5   Calculation of Supplemental N, P, and
       K Fertilizer

Once the application rate of sewage sludge has been deter-
mined, the amounts of plant-available N, P, and K added by
the sludge should be  calculated and compared to the fertil-
izer recommendation  for the crop (and yield level) to be
grown. If the amount of one or more of these three nutrients
provided by the sewage sludge are less than the amount
recommended, then supplemental fertilizers will be needed
to achieve crop yields. Refer to the design example  in
Section 7.5 for an illustration of how this is determined.

7.4.6   Use of Computer Models To Assist in
       Determining Agronomic Rates

Computer modeling  often can be useful for site-specific
evaluation of sewage-sludge-climate-soil-plant N  dy-
namics at a particular location, generally with minimal
additional data collection.

Computer models that specifically model N budgets in
sewage sludge and soil-plant systems can provide site-
specific information on soil physical and hydrologic con-
ditions and climatic influences on N transformations.
The Nitrate Leaching and  Economic Analysis Package
(NLEAP)  developed  by Shaffer et al.  (1991) allows
monthly and event-by-event approaches throughout the
year to compute water and N budgets. The NLEAP
software  is included in the  purchase of Managing Nitro-
gen  for  Groundwater Quality and Farm Profitability
(Follet et al., 1991), which also serves  as an excellent
reference for information on  parameters required for N
budget calculations. Four regional soil and climatic da-
tabases (Upper Midwest, Southern,  Northeastern, and
Western) also are available on disk for use with NLEAP.
These materials can be obtained from:

   Soil Science Society of America
   Attn: Book Order Department
   677 S. Segoe Road
   Madison, Wl 53711
   608/273-2021; Book $36.00;
   Regional Databases $10.00 each.

Current updates of the NLEAP program can be obtained
by sending original diskettes to:

   Mary Brodahl
   USDA-ARS-GPSR
   BoxE
   Fort Collins,  CO 80522

The computer model  DECOMPOSITION (Gilmour and
Clark, 1988) is specifically designed to help predict sew-
age sludge N transformations based on sludge charac-
teristics as well as soil properties and climate  (organic
matter content, mean soil temperature, and water poten-
tial).  Additional  information on this model can be ob-
tained from:

   Mark D. Clark
   Predictive Modeling
   P.O. Box 610
   Fayetteville, AR 72702

Finally, the CREAMS (Chemicals, Runoff, and Erosion
from Agricultural Management Systems) and GLEAMS
(Groundwater Loading Effects of Agricultural Manage-
ment  Systems) models, developed by the U.S. Depart-
ment  of Agriculture (Beasley et al., 1991; Davis et al.,
1990; Knisel, 1980), are other potentially useful models
to assist  with site-specific  management of  sewage
sludge application programs.
                                                 81

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7.5   Design Example of Sewage Sludge
      Application Rate Calculations
The following detailed design example is for a midwest-
ern city with 20 dry ton/day (18 mt/day) of sewage
sludge requiring land application. The sewage sludge
has undergone anaerobic digestion and has the follow-
ing characteristics:
• Solids - 4.8 percent

• Total N - 3.9 percent

• NH4-N  - 1.2 percent

• N03-N  - 200 mg/kg

• Total P - 1.9 percent

• Total K - 0.5 percent

• As - 8  mg/kg

• Cd - 10 mg/kg
• Cr - 130 mg/kg

• Cu - 1,700 mg/kg

• Pb - 150 mg/kg

• Hg - 2 mg/kg

• Mo - 14 mg/kg

• Ni - 49 mg/kg

• Se - 15 mg/kg

• Zn -  1,200 mg/kg
Climatological data  were collected for the application
area as described in Chapter 5. Sewage sludge appli-
cation will be limited during periods of high rainfall and
high soil moisture conditions because of the potential for
surface runoff and the inability to use sludge application
equipment. In addition, sludge application will not occur
during  periods of extended subfreezing temperatures
due to  frozen soils, as indicated by Part 503.

For this site, assume that:

• Annual sewage sludge applications cannot exceed the N
  requirement for the crop grown, as required by Part 503.

• Soil pH will be maintained at levels recommended by
  land-grant universities for the crop to be grown (or
  as required by state regulatory agencies).

• If nutrient additions by the sewage sludge application
  are not sufficient,  supplemental fertilizer nutrients will
  be used to optimize crop production.

• Routine soil fertility testing will be done to establish
  fertilizer recommendations and lime requirements for
  optimum crop growth.

• The  sewage  treatment plant regularly  monitors
  chemical composition of the sludge as required  by
  Part  503 and state regulatory agencies.

• Records  are maintained  as required by Part 503 and
  state regulatory agencies.

Soils in the site  area are generally sandy loams. Soil
fertility  tests have been completed and soil pH is being
maintained as recommended. Crops grown in the area
include corn, soybeans, oats, wheat, and forages for hay
and pasture. For the 1995  growing season, one half of
the fields receiving  sludge will be cropped with wheat
                           requiring 90 Ib/ac (100 kg/ha) of available N per year,
                           and one half of  the fields will be cropped with corn
                           requiring 190 Ib/ac (210 kg/ha) of available N per year.
                           Crop fertilizer requirements were obtained from local
                           Cooperative Extension Service agents for anticipated yield
                           levels of 80 bu/ac for wheat and 160 bu/ac for corn grain.

                           The soil fertility tests indicated that available P levels in
                           the soil are medium, and that available K levels are low.
                            N
P205     K20
Crop
Corn
Wheat
Yield (bu/ac)
160
80
(Ih/ar/year)
190 60 140
90
80
125
Assume that this anaerobically-digested sewage sludge
was previously applied to the fields in  1993 and 1994,
as shown in the following chart:

                        Sewage Sludge  Rate
                         (% Org-N in sludge)
1995 Growing
Season
Corn
Wheat
1994
4.8 ton/acre
(2.8% Org-N)
None
1993
2.6 ton/acre
(2.5% Org-N)
4.6 ton/acre
(2.5% Org-N)
                           For the wheat field, sewage sludge will be applied in the
                           fall after soybeans are harvested and before the winter
                           wheat is planted in the fall of 1994. For the corn fields,
                           sewage sludge will be  applied in the spring of 1995
                           before corn is planted. No other source of N, except for
                           residual N from the 1994 and 1993 sludge applications,
                           are planned for the corn field. The wheat field will have
                           a 30 Ib/acre N credit from the preceding soybean crop
                           and a residual N credit for the 1993 sludge application.
                           No irrigation water will be used, and no manure applica-
                           tions have  been made to either field.

                           The liquid sewage sludge will be  surface applied after
                           soybean harvest before the soil is tilled, prior to the wheat
                           being planted. Incorporation of the sludge will be within 0-1
                           day, and experience with animal manure suggests that
                           30% of the NH4-N is typically lost by ammonia volatiliza-
                           tion. Therefore,  70% will be  conserved and available for
                           plants to use, so K^ = 0.7.  For the corn  field, the liquid
                           sludge will be injected  into the soil, so K^ = 1.0.

                           7.5.1   Calculation of Agronomic N Rate for
                                  Each Field

                           Mineralization of PAN from  the Org-N in this anaerobi-
                           cally digested sewage  sludge  is  assumed to be the
                                                  82

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same as the Kmin values in Table 7-7 suggest, i.e., 20%
the 1st year, 10% the 2nd, and 5% the 3rd. Since the
NO3-N content is negligible (< lib/ton), it is not included
for calculating the PAN for this sewage sludge.

   Total N = 3.9% x 20 = 78 Ib/ton
   NO3-N = 200/kg x 0.002 = 0.4  Ib/ton
   NH4-N = 1.2% x 20 = 24  Ib/ton
   Org-N = 78 - 24 =  54 Ib/ton

For the wheat field where sewage sludge is to be sur-
face applied:

   PAN   = Kvol (NH4-N) +  Kmin (Org-N) =
            0.7 (24 Ib/ton) + 0.20 (54 Ib/ton) =
            17 + 11  =
            28 Ib/ton

For the corn field where sludge is to be injected:
   PAN   = Kvol (NH4-N) +
            1.0 (24 Ib/ton)
            24  + 11 =
            35  Ib/ton
Kmin (Org-N) =
* 0.20  (54 Ib/ton)
To calculate the residual N mineralized from previous
sewage sludge applications, the Worksheet 1 chart is
completed for each field, as shown in Figure 7-3. As
indicated in Section 7.5 above, the wheat  field had
sewage sludge applied in  1993, and the corn field re-
ceived sludge applications in 1993 and 1994.

Forthe wheat field, Org-N originally applied in 1993 was:

   Org-N = 4.6 ton/acre x 20 (2.5% Org-N) =
   4.6 ton/acre x 50 Ib/ton = 230 Ib Org-N/acre

Forthe corn field, Org-N originally applied in  1993 and
1994 was:
   1993:  Org-N = 2.6 ton/acre x 20 (2.5% Org-N) =
          2.6 ton/acre x 50 Ib/ton =
          130 Ib Org-N/acre

   1994:  Org-N = 4.8 ton/acre x 20 (2.8% Org-N) =
          4.8 ton/acre x 56 Ib/ton =
          270 Ib Org-N/acre

Therefore, as the Worksheet 1 charts show (Figure 7-3),
the PAN credit to use in Worksheet 2 for the wheat field
due to previous sewage sludge application is 8  Ib N/acre.
The PAN credit to use in Worksheet 2 forthe corn field due
to previous sewage sludge applications is 27 Ib N/acre.

The agronomic N rate can now be calculated for the
wheat field using Worksheet 2,  as shown in Figure 7-4.
The  legume credit  of 30 Ib N/acre for the  previous
soybean crop  is shown on line 2.a, and the residual
sludge N credit is written on line 2.d. The total N credits
of 38  Ib/acre are subtracted from the fertilizer  N recom-
                           mendation to get the adjusted N requirement. This re-
                           maining N requirement is then divided by the PAN cal-
                           culated earlier in this section forthe wheat field, i.e., 28
                           Ib N/ton, to get an  agronomic N sludge rate of 1.9 dry
                           ton/acre. This rate will be equivalent to:
                               1 9 dry ton  100 wet ton (i.e., 4.8% solids )
                               	x	^—	 x
                                  acre              4.8 dry ton
                                  2,000 Ib
                                   wet ton   8.34 Ib
                                                   = 9,500 gallons/acre
A separate Worksheet 2 can be used to calculate the
agronomic rate forthe corn field, as shown in Figure 7-5.
The only N credit for this field is the residual sludge N
credit shown on line 2.d., which is subtracted from the
fertilizer N recommendation to get the adjusted N re-
quirement (i.e., 163 Ib N/acre). Dividing this requirement
by the PAN/ton calculated earlier forthe corn field, i.e.,
35 Ib  N/ton, will obtain the agronomic N sludge rate of
4.7 dry ton/acre. This  rate can be  converted to a wet
weight basis, as was done for the wheat field, which is
equivalent to 23,500 gallons/acre. This amount of liquid
cannot be injected in a single application, so two appli-
cations of ~12,000 gal/acre each will be needed.

7.5.2  Calculation of Long-Term Pollutant
       Loadings and Maximum Sewage
       Sludge Quantities

By comparing the pollutant concentrations in this design
example  to the Part 503  limits (see Chapter  3), the
reader will find that all trace element levels in the sew-
age sludge meet the "pollutant concentration limits" ex-
cept copper. Therefore, CPLR limits must be met for this
sewage sludge. Utilizing the "maximum sewage sludge
allowed" equation from Section 7.4.4.3 and the CPLRs
from Table 7-9, the total quantity of sludge that could be
applied before exceeding the CPLR limit for each pollu-
tant can be estimated:
                           Arsenic          Max. sludge = 37 Ib/acre -^
                                            0.002 (8 mg/kg) = -2,300 dry
                                            ton/acre
                           Cadmium        Max. sludge = 35 Ib/acre -^
                                            0.002 (10 mg/kg) = 1,750 dry
                                            ton/acre
                           Chromium        Pollutant limits will most likely be
                                            deleted from Part 503 rule
                           Copper          Max. sludge = 1,300  Ib/acre +
                                            0.002 (1,700 mg/kg) = 382 dry
                                            ton/acre
                           Lead             Max. sludge = 270 Ib/acre +
                                            0.002(150  mg/kg) = 900 dry
                                            ton/acre
                                                  83

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Mercury          Max. sludge = 15 Ib/acre  +
                 0.002 (2 mg/kg) = 3,750 dry
                 ton/acre
Molybdenum     Currently, no CPLR is required
                 for Mo.
Nickel            Max. sludge = 380 Ib/acre -^
                 0.002 (49  mg/kg) = -3,900 dry
                 ton/acre
Selenium         Max. sludge = 90 Ib/acre  -^
                 0.002 (15  mg/kg) = 3,000 dry
                 ton/acre
Zinc             Max. sludge = 2,500 Ib/acre -^
                 0.002 (1,200 mg/kg) = ~1,040 dry
                 ton/acre

Assuming this particular sewage sludge continued
to have the same concentrations overtime, Cu would
continue to be the limiting pollutant. The pollutant load-
ings for each individual sewage sludge application
must be determined and recorded to keep a  cumulative
summation of the total quantity of each pollutant that
has  been  added to each  field receiving this sewage
sludge. To calculate the  quantity of each pollutant
applied, the following equation from Section 7.4.4.3
can  be used:

   Sludge rate (dry ton/acre) x 0.002 (mg/kg pollu-
   tant) =  Ib pollutant/acre

For the two agronomic  N rates calculated  in  Section
7.5.1, the amounts of each pollutant added by the sew-
age sludge are shown in Table 7-10.

Table 7-10.  Amounts of Pollutants Added by Sewage Sludge
          in Design Example
Pollutant
Arsenic
Cadmium
Chromium3
Copper
Lead
Mercury
Molybdenuma
Nickel
Selenium
Zinc
Cone, in
Sludge
mg/kg
8
10
-
1,700
150
2
-
49
15
1,200
Wheat Field
(1.9 ton/acre)
Corn Field
(4.7 ton/acre)
Ib/acre
0.030
0.038
-
6.5
0.57
0.0076
-
0.19
0.057
4.6
0.075
0.094
-
16
1.4
0.019
-
0.46
0.14
11
1 Limits for chromium will most likely be deleted from Part 503. Currently,
 no calculation or recordkeeping for a CPLR is required for Mo.
These quantities would be added to the cumulative total
kept for each field receiving any sewage sludge that is
meeting CPLRs.

The approximate number of years that sewage sludge
(of the quality assumed in this design example) could be
applied before reaching the CPLR can be estimated. If
the pollutant  concentrations remain  the  same  and  an
average, annual application rate is assumed, the maxi-
mum  sludge  quantity calculated above for the most
limiting pollutant (i.e., Cu) can be used to estimate the
number of years a site could  be continuously utilized.
For this calculation, we will assume an average rate of
3.3 ton/acre/year, obtained by averaging the agronomic
N rates for the wheat field and the corn field [i.e., (1.9 +
4.7) -^ 2]. Using the following  equation, the number of
years can then be estimated:

   Max. sludge allowed  -^ average annual rate =
   number of years:

   382 dry ton/acre -^ 3.3 dry ton/acre/year = ~116 years

Thus, these  preliminary  calculations indicate that Part
503 CPLR limits will likely not constrain the application
of sewage sludge if its quality was similar to that used
in this design example.

If the concentration of Cu was reduced until it met the
Part 503 pollutant concentration limits and all other pol-
lutant concentrations  remained constant,  the  CPLRs
would no longer have to be recorded to comply with the
503 regulation (see Chapter 3).
                                                      7.5.3   Calculation of Agronomic P Rate for
                                                             Each Field
The equation from Section 7.4.4.2 can be used to cal-
culate the agronomic P rate for the wheat field and corn
field  used in this design example. For the anaerobic
sewage sludge containing 1.9% total P, plant available
P2O5 can be estimated:

   Total P2O5/dry ton = 1.9% x 20 x 2.3 =
   87 Ib P2Os/dry ton

   Avail. P2Os/dry ton = 0.5 (87 Ib total P2Os/dry ton) =
   -44 Ib P2Os/dry ton

For the wheat field, the agronomic P rate is calculated
as follows:
                                                  84

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    Wheat Field - 1995 Growing Season
A. Year of
Growing Season

0-1 (1993
Application)
1-2 (1994)
2-3 (1995)
B. Starting Org-
N (Ib/acre)
C. Mineralization
Rate (K,^)
1993 Sludge Appli

230
184
166
0.20
0.10
0.05
D. Mineralized
Org-N (Ib/acre)
E. Org-N
Remaining
(Ib/acre)
cation
46
18
8
184
166
158
   PAN credit for the 1993 sludge application during 1995 is 8 Ib N/acre.
    Corn Field - 1995 Growing Season
A. Year of
Growing Season

0-1 (1993
Application)
1-2 (1994)
2-3 (1995)

0-1 (1994
Application)
1-2 (1995)
2-3 (1996)
B. Starting Org-
N (Ib/acre)
C. Mineralization
Rate (K^)
1993 Sludge Apoli

130
104
94
0.20
0.10
0.05
1994 Sludge Appli

270
216
194
0.20
0.10
0.05
D. Mineralized
Org-N (Ib/acre)
E. Org-N
Remaining
(Ib/acre)
cation
26
10
5
104
94
89
cation
54
22
10
216
194
184
   PAN credit for the 1995 growing season on this field due to sewage sludge applications in 1993 and 1994
   is:  5 + 22 = 27 Ib N/acre.
Figure 7-3. Worksheet 1 calculations to determine residual N credits for previous sewage sludge applications.
                                                     85

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                                                      Worksheet 2
                             Nitrogen Budget Sheet for Determining the Agronomic N Rate
                                             for Sewage Sludge Applications
                                            Symbols and Abbreviations Used

           Org-N — Organic N content of the sewage sludge obtained from analytical testing and determined by
                subtracting (NO3-N + NH4-N) from total N, usually given in percent (%); the resulting
                concentration should be converted to Ib/ton (dry weight basis).
           NH4-N = Ammonium N content of the sewage sludge obtained from analytical testing and usually
                given in percent (%); then convert to Ib/ton (d.w. basis).
           NO3-N = Nitrate N content of the sewage sludge obtained from analytical testing and often given in
                mg/kg; then convert to Ib/ton  (d.w. basis).
                = Mineralization rate for the  sewage sludge expressed as a fraction of the sludge Org-N
                expected to be released as PAN for the year being calculated; example mineralization rates for
                different sewage sludges can be found in Table 7-7.
                = Volatilization factor for estimating the amount of NH4-N remaining after loss to the
                atmosphere as ammonia and expressed as a fraction  (e.g., if K,,^ = 1.0, 100% of the NH4-N is
                retained and contributes to PAN; if K^  = 05, then  (0.5 x NH4-N content) estimates the amount
                of NH4-N contributing to PAN).
           PAN =  Plant-available N which is  determined by calculating:  NO3-N + K^NH^N) + K^Org-N)

                                                  Helpful Conversions

                mg/kg x 0.002  = IbAon        Ib/acre x  1.12 = kg/ha           Ib/ton -=- 2 = kg/mt
                % x 20 = Ib/ton               ton/acre x 2.24 = mt/ha         (mt = metric ton =  1000 kg)

      1.  Total N requirement of crop to be grown (obtain information from Cooperative Extension                   90    Ib/acre
         Service agricultural agents, USDA-Natural Resource Conservation Service or other
         agronomy professionals).

      2.  Nitrogen provided from other N sources added or mineralized in the soil
         a.  N from a previous legume crop (legume credit) or green manure crop               30     Ib/acre
         b.  N from supplemental fertilizers already, or expected to be, added                  -     Ib/acre
         c.  N that will be added by irrigation water                                       --     Ib/acre
         d.  Estimate of available N from previous sludge applications (from Worksheet 1)         8     Ib/acre
         e.  Estimate of available N from a previous manure application (obtain mineralization     —     Ib/acre
            factors from land-grant university to calculate similarly as for previous sewage
            sludge applications).
         f.  Soil nitrate test of available N present in soil [this quantity can be substituted          -     Ib/acre
            in place of (a + d + e), if test is conducted property; do not use this test value if
            estimates for a, d and e are used]

         Total N available from existing, expected, and planned sources of N (add a+b+c+d+e orb+c+f)           38	Ib/acre

      3.  Loss of available N by denitrification, immobilization, or NH4* fixation (check with state regulatory            -	Ib/acre
         agency for approval, before using this site-specific factor).

      4.  Calculate  the adjusted fertilizer N requirement for the crop to be grown (subtract Total N for (2)            52	Ib/acre
         from (1); amount for (3) can be added to this difference, only if (3) is approved for this additional adjustment).


Figure 7-4.  Calculation of the agronomic N rate for the wheat field.
                                                           86

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                                                 Worksheet 2  (continued)
   5.  Determine the PAN/dry ton for the sludge that will be applied                                           28       Ib/ton
       [i.e., NO,-N + K^ (NH,-N) + K^. (Org-N) = PAN]

   6.  Calculate the agronomic N rate of sewage sludge (Divide (4) by (5))                                       1.9     ton/acre

   7.  Convert the rate of sewage sludge in dry tons/acre into gallons/acre, cubic yards/acre, or wet tons/acre,
       since the sludge will be applied to land as a liquid or as a wet cake material.
Figure 7-4.  Calculation of the agronomic N rate for the wheat field (continued).
                                                               87

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                                                     Worksheet 2
                           Nitrogen Budget Sheet for Determining the Agronomic N Rate
                                           for Sewage Sludge Applications
                                           Symbols and Abbreviations Used

         Org-N =  Organic N content of the sewage sludge obtained from analytical testing and determined by
               subtracting (NO3-N + NH4-N)  from total N, usually given in percent (%); the resulting
               concentration should be converted to Ib/ton (dry weight basis).
         NH4-N = Ammonium N content of the sewage sludge obtained from analytical testing and usually
               given in percent (%); then convert to Ib/ton (d.w. basis).
         NO3-N = Nitrate N content of the sewage sludge obtained from analytical testing and often given in
               mg/kg; then convert to Ib/ton (d.w. basis).
               = Mineralization rate for the sewage sludge expressed as a fraction of the sludge Org-N
               expected to be released as PAN for the year being calculated; example mineralization rates for
               different sewage sludges can be found in Table 7-7.
              = Volatilization factor for  estimating the amount of NH4-N remaining after loss to the
               atmosphere as ammonia and expressed as a fraction  (e.g., if K^j = 1.0, 100% of the NH4-N is
               retained and contributes to PAN; if K,,,,, = 0.5, then  (0.5 x NH4-N content) estimates the amount
               of NH4-N contributing to PAN).
         PAN = Plant-available N which is determined by calculating:  NO3-N +  K,,ol(NH4-N) + Kmin(Org-N)

                                                 Helpful Conversions

               mg/kg x 0.002  = Ib/ton         Ib/acrex 1.12 = kg/ha           Ib/ton + 2 = kg/mt
               % x 20 =  Ib/ton                ton/acre x 2.24 = mt/ha         (mt = metric ton =  1000 kg)

    1. Total N requirement of crop to be grown (obtain information from Cooperative Extension                   190    Ib/acre
       Service agricultural agents, USDA-Natural Resource Conservation Service or other
       agronomy professionals).

    2. Nitrogen provided from other N sources added or mineralized in the soil
       a.  N from a previous legume crop (legume credit) or green manure crop              -     Ib/acre
       b.  N from supplemental fertilizers already, or  expected to be, added                 --     Ib/acre
       c.  N that will be added by irrigation water                                       --     Ib/acre
       d.  Estimate of available N from previous sludge applications (from Worksheet 1)        27     Ib/acre
       e.  Estimate of available N from a previous manure application (obtain mineralization    --	Ib/acre
          factors from land-grant university to calculate similarly as for previous sewage
          sludge applications).
       f.  Soil  nitrate test of available N present in soil [this quantity can be substituted         --     Ib/acre
          in place of (a + d + e), if test is conducted properly; do not use this test value if
          estimates for a, d and e are used]

       Total N  available from existing, expected, and planned sources of N (add a+b+c+d+e or b+c+f)           27	Ib/acre

    3. Loss of available N by denitrification, immobilization, or NH4+ fixation (check with state regulatory            —	Ib/acre
       agency for approval, before using this site-specific factor).

    4. Calculate the adjusted fertilizer N requirement for the crop to be grown (subtract Total N for (2)            163	Ib/acre
       from (1); amount for (3) can be added to this difference, onfy if (3) is approved for this additional adjustment).

Figure 7-5.   Calculation of the agronomic N rate for the corn field.
                                                          88

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                                                   Worksheet 2 (continued)
     5.  Determine the PAN/dry ton for the sludge that will be applied                                            35	Ib/ton
        [i.e., NO3-N + K,., (NH4-N) + K^. (Org-N) = PAN]

     6.  Calculate  the agronomic N rate of sewage sludge (Divide (4) by (5))                                        4.7      ton/acre

     7.  Convert the rate of sewage sludge in dry tons/acre into gallons/acre, cubic yards/acre, or wet tons/acre,
        since the sludge will be applied to land as a liquid or as a wet cake material.
Figure 7-5.  Calculation of the agronomic N rate for the corn field (continued).
                                                               89

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   Preq = Fertilizer P2Os Recommendation =
   80 Ib P2Os/acre, so

   Agronomic P rate  =  Preq + Avail. P2Os/dry ton =
   80 Ib P2Os/acre ^ 44 Ib P2Os/dry ton =
   ~1.8 dry ton/acre

   For the corn field, the agronomic P rate would be:

   Preq = 60 Ib  P2Os/acre, so

   Agronomic P rate  =  60 Ib P2Os/acre +
   44 Ib P2Os/dry ton = ~1.4 dry ton/acre

Since  the  agronomic  P rate  for  each field is less
than the agronomic  N  rate, these  rates could be se-
lected  to use.  The consequence of utilizing  P rates
rather than N rates is that less sewage sludge per acre
will normally  be applied,  so more  land area will be
needed to apply the total sludge produced by the treat-
ment works.  For example, the design example treat-
ment works generates  7,300 dry ton/year (i.e., 20 dry
ton/day x 365 days/year). If sludge was applied at a rate
equal to the agronomic P rate for the corn field,  about
5,220  acres/year would  be  needed to apply all the
sludge produced (i.e.,  7,300  dry ton/year -^  1.4 dry
ton/acre). But if sludge was applied  at the agronomic N
rate for the corn field, only about  1,560 acres would be
needed to apply all the sludge produced (i.e., 7,300 dry
ton/year -^ 4.7 dry ton/acre).

Alternatively, continuously using the agronomic N rate
would result in excess P (beyond what the crop needs)
being applied. As was discussed in Section 7.4.4.2, soil
P fertility levels will likely be increased overtime. Unusu-
ally high soil P levels  can potentially increase the  risk of
nonpoint source pollution losses of P to surface waters
and contribute to undesirable water quality. A second
consequence is that supplemental N fertilizers  must be
added  to fulfill the remaining N needs of the crop not
supplied by the sewage sludge.  The quantity  of addi-
tional N can be calculated by returning to Worksheet  2
and multiplying the PAN/dry ton times the rate of sewage
sludge applied, and then subtracting  this PAN/acre
value from the adjusted fertilizer N requirement.

For example, using Figure 7-5 for the corn field and
assuming the agronomic P rate was used  (i.e., 1.4 dry
ton/acre), the supplemental N fertilizer needed is:

   35 Ib PAN/dry ton x 1.4 dry ton/acre =
   49 Ib PAN/acre
   163 Ib N/acre - 49 Ib N/acre = 114 Ib N/acre
7.5.4   Calculation of Supplemental K
        Fertilizer To Meet Crop Nutrient
        Requirements

Because K is a soluble nutrient, most of the K received
by a treatment works is discharged with effluents. Con-
sequently, sewage sludges will contain low concentra-
tions of this  major plant nutrient. Therefore,  fertilizer
potash (K2O) or other sources of K will be needed to
supplement the  quantities of K2O added by  sewage
sludge applications, particularly over the long-term.

The amount  of  sewage sludge  K2O  applied  can be
calculated from sludge analysis information in a similar
manner as is done for P2O5 (Section 7.4.4.2).  Since K
is readily soluble, however, all the K in sewage sludge
is assumed to be available for crop growth compared to
P, which is assumed to be about 50% available to plants.
As  with P, soil fertility testing can be  used to monitor
these  K2O additions and determine additional K2O that
is needed for crops.

The quantity of K2O that can be credited against the K2O
fertilizer recommendation is calculated  using the follow-
ing  equation:

   Sludge K2
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7.5.5   A dditional Considerations for Land
         Application Program Planning

To simplify the design example, only two fields with differ-
ent crops were  considered. For most land application
programs, however, sewage sludge will be applied to more
than two crops and to many individual fields. Application
rate calculations should be made for each field receiving
sewage sludge  as a detailed plan is developed. For this
design example, additional crops could be oats, soybeans,
and forages for hay and  pasture.  Crop  rotations  and
relative  acreages of each crop will  vary from one crop
producer to another. Also keep in mind that farms with
livestock will  be producing animal  manure nutrients in
addition to  the  sewage sludge nutrients  used  for sup-
plying plant nutrient requirements on the acreage avail-
able for growing crops.


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CAST. 1980. Effects of sewage sludge on  the  cadmium and zinc
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CAST. 1976. Application of sewage sludge to cropland: Appraisal of
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Chaney, R.L. 1984. Potential effects of sludge-born heavy metals and
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Chaney, R.L. 1983a. Plant uptake of inorganic waste constituents. In:
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Chaney, R.L. 1983b. Potential effects of waste constituents on the
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Chaney, R.L. 1973. Crop and food chain effects of toxic elements in
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Chaney, R.L., and P.M. Giordano. 1977. Microelements as related to
   plant deficiencies and toxicities. In: Elliott, L.F., and F.J. Stevenson,
   eds.  Soils for management of organic wastes and waste waters.
   American Society of Agronomy, Madison, Wl. p. 235-279.

Christensen, B.T 1986. Ammonia volatilization loss from surface ap-
   plied animal manure. In: Dam Kofoed, A.,  J.H. Williams, and P.
   L'Hermite, eds.  Efficient land use of sludge and manure. London:
   England: Science Publishers  Ltd. pp. 193-203.

Davis, R.D., G. Hucker, and P. L'Hermite. 1983. Environmental effects
   of organic and inorganic contaminants in sewage sludge. Dor-
   drecht, Holland: D.  Reidel Publishing Company, p. 257

Davis, F., W. Knisel, and R. Leonard. 1990.  GLEAMS user manual,
   Version 1.8.55. Lab.  Note SEWRL-030290FMD. Agricultural Re-
   search Service, U.S. Department of Agriculture, Tifton, GA.

Dbhler, H., and M. Wiechmann. 1988.  Ammonia volatilization from
   liquid manure  after application in the field. In: Welte, E.,  and  I.
   Szabolcs, eds. Agricultural waste management and environmental
   protection, Vol. 2. Groltze-Druck,  Goettingen, Federal Republic of
   Germany, pp. 305-313.

Follet, R., D. Keeney, and R. Cruse, eds. 1991.  Managing nitrogen for
   groundwater quality and farm profitability. Soil Science Society of
   America, Madison, Wl. p. 357.
                                                            91

-------
Fresquez, P., R. Aguilar, R. Francis, and E. Aldon. 1991. Heavy metal
   uptake by  blue  grama growing in a  degraded  semiarid soil
   amended with sewage sludge. The Netherlands: Kluwer Academic
   Publishers.

Fresquez, P., R. Francis, and  G. Dennis. 1990. Soil and vegetation
   responses to sewage  sludge on  a degraded  semiarid  broom
   snakeweed/blue  grama  plant  community.  J.  Range  Mgmt.
   43(4):325-331.

Gallier, W, B. Brobst, R. Aguilar, K. Barbarick, P. Hegeman, B. Jan-
   onis, D. Salahub, and S. Wilson. 1993. Rx for rangelands. Water
   Environ, and Tech. 5:10.

Gilmour, J., and M. Clark. 1988. Nitrogen release from wastewater
   sludge: A site specific  approach. J. Water  Pollut. Control  Fed.
   60:494-341.

Hall, J.E., and J.C. Ryden. 1986. Current UK research into ammonia
   losses from  sludges  and slurries. In:  Dam Kofoed, A.,  J.H. Wil-
   liams, and  P. L'Hermite, eds. Efficient  land use  of sludge and
   manure. London, England: Science  Publishers Ltd. pp. 180-192.

Harmsen, G.W, and D.A.  Van Schreven. 1955. Mineralization of organic
   nitrogen in soil. Adv. Agron. 7:299-398.

Hoff, J.D., D.W. Nelson, and A.L. Sutton. 1981. Ammonia volatilization
   from liquid swine manure applied to cropland. J. Environ. Quality
   10:90-95.

Ippolito, J., K. Barbarick,  D. Westfall, R. Follett, and R. Jepson. 1992.
   Application  of anaerobically digested  sewage sludge to dryland
   winter wheat. Technical Report TR92-5. Agricultural Experiment
   Station, Colorado State University.

Jacobs, L, S.  Carr,  S. Bohm, and J.  Stukenberg. 1993. Document
   long-term experience  of biosolids land application programs. Pro-
   ject 91-ISP-4. Water  Environment Research  Foundation. Alexan-
   dria, VA.

Keeney, D.R. 1989. Sources of nitrate to groundwater. In: R.F. Follett,
   ed. Nitrogen management and ground water protection. Amster-
   dam, the  Netherlands: Elsevier Science  Publishers, pp.  23-34.

Knisel, W, ed. 1980. CREAMS: A field-scale model for chemicals, runoff,
   and erosion from agricultural management systems. Conservation
   Research Report No. 26. U.S. Department of Agriculture, Washing-
   ton, DC. p. 643.

Lauer, D.A., D.R. Bouldin, and S.D. Klausner. 1976. Ammonia vola-
   tilization from dairy manure spread on the soil surface. J. Environ.
   Quality 5:134-141.

L'Hermite, P., and J. Dehandtschutter. 1981.  Copper in animal wastes
   and  sewage  sludge.  Dordrecht, Holland: D. Reidel  Publishing
   Company, p. 378.

Lindsay, WL. 1973. Inorganic reactions of sewage wastes with soils.
   In:  Proceedings  of  Joint  Conference  on Recycling  Municipal
   Sludges and  Effluents on Land,  Champaign, IL (July 9-13). Na-
   tional Asssociation of  State Universities and Land-Grant Colleges,
   Washington, DC. pp.  91-96.

Logan, T.J., and R.L. Chaney. 1983. Utilization of municipal waste-
   water and sludge on  land  -metals. In: Page, A.L.,  T.L.  Gleason,
   III, J.E. Smith, Jr., I.K.  Iskandar, and L.E. Sommers, eds. Utilization
   of municipal wastewater and sludge on land.  University of Califor-
   nia, Riverside, CA. pp. 235-326.

Melsted, S.W. 1973. Soil-plant relationships (some  practical consid-
   erations in waste management).  In:  Proceedings of Joint Confer-
   ence on  Recycling Municipal Sludges  and Effluents on  Land,
   Champaign,  IL (July 9-13).  National Asssociation of State Univer-
   sities and Land-Grant Colleges, Washington, DC. pp.  121-128.
Page, A.L., T.J. Logan, and J.A. Ryan, eds. 1987. Land application
   of sludge—food chain implications. Chelsea, Ml: Lewis Publishers,
   Inc. p. 168.

Peterson, R., and M. Madison. 1992. Benefits of transporting biosolids
   from a wet climate  to a dry climate. Presented at Water Environ-
   ment Federation  Specialty Conference, July 26-30.

Pierce, B., E. Redente, and  K. Barbarick. 1992.  Review of sewage
   sludge-amended  rangeland at Walcott, Colorado. Progress Report
   to Colorado Department of Health and U.S. EPA. Colorado State
   University, Fort Collins, CO.

Pierce, B. 1994. The  effect  of biosolids application  on a semiarid
   rangeland site  in Colorado. M.S. Thesis, Colorado State Univer-
   sity, Fort Collins,  CO.

Powers, W.L., G.W. Wallingford, and L.S. Murphy.  1975. Formulas for
   applying organic  wastes to land. J. Soil Water Conserv. 30:286-
   289.

Pratt, P.F.,  F.E. Broadbent,  and  J.P.  Martin.  1973.  Using organic
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                                                              93

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                                              Chapter 8
                     Process Design for Forest Land Application Sites
8.1   General

Sewage sludge application to forests can greatly  in-
crease forest productivity. Research at the University of
Washington showed that for some tree species, the use
of sewage sludge as a fertilizer resulted in excellent and
prolonged increases in height and diametergrowth com-
pared to controls (Henry et al., 1993). Sewage sludge
amends the soil by providing nutrients, especially nitro-
gen (N) and  phosphorus (P), that are frequently limited
in forest soils, and  by improving soil textural charac-
teristics. Sewage  sludge addition can improve  short-
term soil productivity because it provides an immediate
supply of virtually every nutrient needed for plant growth
in an  available form. In addition, the fine  particles and
organics in sewage sludge can immediately and perma-
nently enhance soil moisture and nutrient-holding char-
acteristics. In the long-term, sewage sludge provides a
continual slow release input of nutrients as the organics
decompose.

Forest soils  are in many ways well suited to sewage
sludge application. They have high rates of  infiltration
(which reduce runoff and ponding), large amounts of
organic material (which immobilize metals from the sew-
age sludge), and  perennial root systems (which  allow
year-round application in mild climates). Although forest
soils are frequently quite acidic, research has found no
problems with metal  leaching following sewage sludge
application (U.S. EPA, 1984).

One major advantage of forest application over agricul-
tural application is that forest products (e.g., wild edible
berries, mushrooms, game, and nuts) are an insignifi-
cant part of the human food chain. In  addition, in many
regions, forest land is extensive and provides  a reason-
able sewage sludge land application alternative to agri-
cultural cropland. The primary environmental and public
health concern associated with forest  application is pol-
lution  of water supplies. In  many areas,  particularly in
the western states, forest lands form crucial watersheds
and ground-water  recharge areas.  Contamination of
water supplies by nitrates can be prevented by limiting
sewage sludge application rates according to the nitro-
gen needs of the crop (as required  by the  Part 503
regulation), in this case trees (approximately 10 to 100
metric tons dry weight per hectare [t DW/ha] in a single
application every 3 to 5 years).

Application of sewage sludge to forest land is feasible
on commercial timber and fiber production lands, federal
and state  forests, and privately owned woodlots. Sew-
age sludge use in nurseries, green belt management,
and Christmas tree production also is possible.

This chapter discusses sewage sludge applications to
forest land for three common situations: (1)  recently
cleared forest land that has not been planted, (2) young
plantations (planted or coppice),  and (3)  established
forest stands. Each of these  cases presents different
design issues and  opportunities.  Public participation
considerations are a critical aspect of forest land appli-
cation systems, as discussed in Chapter 12.

8.2   Regulatory Requirements and Other
      Considerations

The federal Part  503  regulatory  requirements  associ-
ated with  land application of sewage sludge to forest
lands regarding  metals, pathogens, and  nitrogen are
discussed in Chapter 3. Issues particularly relevant to
land application at forest sites are  discussed below.

8.2.1  Pathogens

Organisms present in forest soils are responsible for the
relatively quick die off of pathogens following sewage
sludge application to a forest site.  Microorganisms pre-
sent in the sewage sludge are initially filtered out by the
soil and forest floor and then replaced by the native
organisms of the soil. The survival time for most micro-
organisms following land  application of sewage sludge
to forests typically is very short but depends on a variety
of soil and climatic conditions including temperature,
moisture content, and pH.1  For a  further discussion of
pathogen  die off, see Chapter 4.

Pathogen-related  concerns involving windborne con-
tamination may arise when spray application of liquid
1 Henry, Charles. Biosolids Utilization in Forest Lands. Draft report.
 University of Washington, Eatonville, WA.
                                                  95

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sewage sludge on forest lands is used. Precautions can
be taken to minimize exposure during and after spray
application, such as restricting public access from the
area downwind during the spray application  and  for
several  hours after spraying is completed, and consid-
ering wind velocity so that applications can be control-
led.  Generally, aerosols  will not  travel  far in  an
established, non-dormant forest because of interception
by the leaves and breakup of wind currents.

8.2.2   Nitrogen Dynamics

As with other types of land application  sites, nitrogen
needs at forest sites (i.e., N needed by trees and under-
story) are an essential component of the land application
system. Sewage sludge at a forest site must be applied
at a rate that is equal to or less than the agronomic rate
forN, as required by the Part 503 regulation. Key factors
regarding nitrogen levels at forest sites include nitrogen
uptake by plants;  mineralization of nitrogen; ammonia
volatilization; denitrification; soil immobilization rates; ni-
trogen leaching; and temperature-related effects. These
factors are discussed in Section 8.9  below, particularly
as they affect determination of sewage sludge applica-
tion rates at forest sites.

8.3   Effect of Sewage Sludge
      Applications on Tree Growth and
      Wood Properties

8.3.1   Seedling Survival

Seedlings of deciduous species and  many conifers, in-
cluding Douglas fir and Sitka spruce, have shown excel-
lent  tolerance  to  sewage sludge  in   demonstration
projects. At relatively light application rates (i.e. agro-
nomic loadings), seedling mortality is not a problem, and
planting should be possible soon after sludge application.

8.3.2   Growth Response

Growth response has been documented on a number of
stands of Douglas-fir in Washington (Henry etal., 1993).
Growth  responses can range from  2% to 100%  for
existing stands, and over 1,000% for trees planted  in
soils amended with  heavy  applications  of  sewage
sludge. The magnitude of this response depends on site
characteristics and tree stand ages.  Some of the main
site differences affecting growth response include:

• Site class. In both young Douglas-fir plantations and
  older  stands, greater growth responses have been
  found where the trees are doing poorly due to  lack
  of nutrients.

• Thinned versus unthinned stands  treated with sew-
  age sludge. There appears to  be  little difference  in
  total wood produced in unthinned versus thinned stands
  that have received sewage sludge applications. In thinned
  stands, however, growth is concentrated in trees with
  larger diameters.

• Response by species. Most tree species grow faster
  in soil treated with sewage sludge;  however, some
  species respond dramatically while others show only
  a slight  response.  Excellent  response has  been
  shown by black locust, European alder, hybrid poplar,
  Japanese larch, and catalpa (Sopper, 1993).

Greater growth  responses have been seen when trees
have been planted directly in soil already amended with
large amounts of sewage sludge, such as a  soil recla-
mation site. In this case, special management practices
are required. An excellent example of this type of appli-
cation is Christmas tree plantations.

Because sewage sludge application to forest sites is
relatively new and limited data have been collected, it is
difficult to estimate the value added to a forest site when
sewage sludge is land applied. A conservative estimate
of the value of sewage sludge could be based on the
value  of the  nitrogen fertilizer potential  alone,  which
would be approximately $30/dry ton of sewage sludge.
Preliminary studies, however,  have  shown  a  greater
growth response  to sewage sludge  than  to chemical
nitrogen fertilizer. Additionally, the effect appears to be
much  longer lasting, with some studies showing contin-
ued growth response 8 years after application.

8.3.3  Wood Quality

Accelerated tree growth  (200 to 300  percent) resulting
from sewage  sludge addition has  the  potential for
changing basic wood characteristics, including specific
gravity, shrinkage, fibril angle, and certain mechanical
properties.  Research indicates that both positive and
negative effects on wood quality occur in trees grown on
sewage sludge-amended soil.  In some studies, static
bending tests, which show combined effects,  have indi-
cated  no significant change when the strength proper-
ties of specimens cut  from trees grown on sewage
sludge-amended soils were compared  with specimens
of wood produced without sewage sludge. Other studies
have shown a 10 to 15 percent reduction in density and
in modulus  of rupture and elasticity.2

8.4   Effect of Sewage Sludge Application
      on  Forest Ecosystems

Although immediately after land application of sewage
sludge a site is greatly altered in appearance, within six
months understory growth often is much more vigorous
than before sewage sludge application. Increased un-
derstory also is typically higher  in nutrients and can
provide better habitat for wildlife. A number of wildlife
studies have found increased populations of animals on
• See footnote 1.
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sites receiving sewage sludge compared to nearby sites
that were not amended with sewage sludge (Henry and
Harrison, 1991).

8.5   Forest Application Opportunities

8.5.1   Forest Stand Types

The land application designer may have  the option of
selecting among the following types of forest sites for
sewage sludge addition:

• Sites recently cleared prior to replanting.

• Young  plantations of an age conducive to sewage
  sludge application over the tops of trees.

• Established forests.

The advantages and disadvantages associated with each
type of forest site are summarized in Tables 8-1 to 8-3.

8.5.1.1   Applications Prior to Planting

Clearcuts offer the  easiest,  most economical sites for
sewage  sludge  application. Because  application takes
place  prior to tree planting,  many agricultural sewage
sludge application methods can be used. Vehicles de-
livering sewage  sludge from the treatment plant can
discharge semi-solid sewage sludge (15% or more sol-
ids) directly on  the land, followed  by spreading by  a
dozer  and disking.  Ease of delivery depends  on  the
amount  of site  preparation  (stump removal, residual
debris  burning,  etc.),  slopes, soil  conditions,  and
weather.  Site  preparation and sewage sludge charac-
teristics are also major factors in application technique
(e.g., temporary spray irrigation systems;  injectors and
splash plates for liquid material; manure spreaders for
solid material).

While sewage sludge application is easier to perform on
clearcuts, these sites also may require additional man-
agement practices to control grasses and rodents such
as voles.  If application to a clearcut is planned, a pro-
gram of periodic disking and herbicides should be con-
ducted  to control grasses  and rodents.  Tree trunk
protection devices also are available to provide a barrier
against rodent girdling. Additionally, fencing  or bud cap-
ping may be required to prevent excessive deer brows-
ing. Sewage sludge injection into the soil may minimize
plantation establishment problems.
8.5.1.2   Applications to Young Stands

Application of sewage sludge to existing stands typically
is  made by a tanker/sprayer system, which can apply
sewage sludge with an 18% solids content over the tops
of the trees (canopy) 125 feet (40  m) into a plantation.
This method requires application trails at a maximum of
250 feet (80 m) intervals. King County Metro, Washing-
ton (including Seattle), has developed a throw spreader
that is capable of applying a dewatered sewage sludge
up to 70 m over a plantation. This method has greatly
reduced application costs and allows trail spacing of
greater distances (120 m with overlap for evenness of
applications). A good tree age or  size for this type of
application are trees over 5 years or over 4 to 5 feet high
because they minimize maintenance otherwise needed
in  clearcut areas. Timing of applications may be impor-
tant with over-the-canopy applications because sewage
sludge sticking on  new foliage could retard the current
year's growth during the active growth season.
Table 8-1.  Sewage Sludge Application to Recently Cleared Forest Sites
Advantages

    1. Better access for sludge application equipment. Also, optimal access can be established for additional sludge application in the
      future.

    2. Possible option of incorporating the sludge into the soil (versus a surface application) if the site is sufficiently cleared.

    3. Possible option of establishing a flooding or ridge and furrow sludge application system (versus spray application) if the site
      topography is favorable.

    4. Option to select tree species that show good growth and survival characteristics on sludge-amended sites.

    5. Often easier to control public access to the site because cleared areas are less attractive than wooded areas for typical forest
      recreational activities.

Disadvantages

    1. Seedlings have low nitrogen uptake rates. If nitrate contamination of an underlying potable aquifer is a potential problem, initial
      sludge applications must be small relative to the volume of sludge application to established forests.

    2. An intensive program of weed control is necessary since the weeds grow faster than the seedlings and compete for nutrients,
      space, light, etc. Use of herbicides and cultivation between tree rows usually is required for the first 3 to 4 years.

    3. Intensive browsing by deer and damage to young  trees by voles and other pest species may require special control measures,
      since these animals may selectively feed upon trees grown on sludge-amended sites due to their higher food value.
                                                      97

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Table 8-2.   Sewage Sludge Application to Young Forest Plantations (Over 2 Years Old)
Advantages

    1.  Seedlings are established and more tolerant of fresh sludge applications.

    2.  Weed control is less of a problem than with cleared sites because of established trees and vegetation.

    3.  Nitrogen uptake by the trees is rapidly increasing, and acceptable sludge application rates can be higher on these sites over
       aquifers than on recently cleared sites.

    4.  Access  for sludge application equipment usually is still good.

    5.  Rapid growth response from most deciduous and many coniferous tree seedlings can be expected.

Disadvantages

    1.  Sludge application by spraying over the canopy may be restricted to those periods when the trees are dormant, to avoid the
       problem of sludge clinging to foliage. Application during periods of the year when heavy rainfalls are common may potentially
       alleviate this problem. In addition, sewage sludge applied to broad leaf species quickly dries and flakes off the leaves.

    2.  Some weed control will probably be necessary.
Table 8-3.   Sewage Sludge Application to Closed Established Forest (Over 10 Years Old)


Advantages

    1.  Established forests are less susceptible to sludge-induced changes in vegetation (e.g., weed growth).

    2.  Excellent growth response can be expected to  result from the increased nutrients.

    3.  Sludge application by spraying can be done under the tree foliage, so it is not necessary for the trees to be dormant.

    4.  During precipitation, rapid runoff of storm water containing sludge constituents is unlikely because the forest canopy breaks up the
       rain and accumulated organic debris on the forest floor absorbs runoff.

    5.  Forest soils under established forests usually  have high C-to-N ratios resulting in excellent capability to immobilize (store)
       nitrogen for slow release in future years. Consequently, it often is feasible to make an initial  heavy application of sludge, e.g.,
       74 t/ha (33 T/ac), and achieve tree growth response for up to 5 years without subsequent sludge applications.

Disadvantages

    1.  Access by sludge application vehicles into a mature forest often  is difficult. The maximum range of sludge spray cannons is about
       40 m (120 ft). To obtain fairly uniform coverage, the spray application vehicle requires access into the site on a road grid, spaced
       at approximately 75-m  (250-ft) intervals. Most established forest sites do not have such grid-like roads. As a result, access roads
       must be cut through the forest,  or the selected sludge application area(s) are largely restricted to narrow 36-m (120-ft) strips on
       both sides of existing roads. Access into commercial forests is usually easier than into publicly owned forest lands.

    2.  In an established publicly owned forest, it may  not be advantageous to accelerate vegetation with sludge applications. In contrast,
       commercial forest operations desire faster growth of trees.

Notes:
t = metric tonnes
T = English tons (short)
Liquid sewage sludge also has been successfully applied
using a sprinkler irrigation system. Clogging of nozzles has
been the major drawback to this method. Manure spread-
ers are capable  of applying dewatered sewage  sludge
which cannot be  sprayed.  Depending  on the  range  of
sewage sludge trajectory, application trails may need to be
at closer intervals than with other methods.
tures are low and neither N  mineralization (transforma-
tion of organic N to NHjj) or nitrification (transformation
of MM} to NO§) occurs significantly. Thus nutrients are
effectively "stored" until the next growing season.
8.5.1.3   Applications to Mature Stands
It is recommended that sewage sludge applications take
place  during the time that tree growth  is reduced, but
uptake of  nutrients  also is  reduced  during this time.
When sewage  sludge  is first  applied to the  soil, the
available N is in the NHJ form, which does not  leach. In
addition,  in some  cases such  as in northern  cool cli-
mates, during the non-growing  season soil tempera-
Applications  to  older stands have the advantage that
sewage sludge  can  be applied year-round. Because
spraying takes place under the tree foliage, no  foliage
will be affected. Application methods are similarto those
described for young plantations. In many cases, how-
ever, stands are  not in rows, which may eliminate some
of the alternatives available for plantations.
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8.5.2   Christmas Tree Plantations

One clearcut application scenario that has worked well
in the state of Washington is the use of sewage sludge
application in Christmas  tree stands. Typically, a  high
level  of maintenance  is  common,  and weed estab-
lishment and  rodent  populations  are  minimized as
standard practice.

8.6   Equipment for Sewage Sludge
      Application at Forest Sites

8.6.1   Transfer Equipment

Sewage sludge usually  comes from the wastewater
treatment plant  (WWTP)  in an  over-the-road vehicle.
Once at the site it is often stored, at least temporarily,
before being transferred  to an application vehicle. Ex-
ceptions to  storage are when  a  multi-purpose  high-
way/application  vehicle is  used (generally by smaller
facilities) and when applications are close to the WWTP.
The  two basic  mechanisms for transferring  sewage
sludge from vehicles to storage facilities are (1) direct
dumping, and (2) pumping. The transfer method suitable
for a particular site depends on  how liquid the sewage
sludge is (i.e., how easy it is to  pump),  or the position
and  configuration of the storage vessel (i.e.,  whether
gravity is sufficient to transfer the sewage sludge).

Direct dumping of sewage sludge is the easiest method
for unloading a  trailer from a treatment plant. Gravity
dumping requires either using an in-ground storage fa-
cility or driving the truck onto a ramp above the storage
facility.  Additionally,  sewage  sludge must be  dilute
enough to flow from the trailer (<8% solids) or pressur-
ized tank (<15% solids), or the trailer bed must be tilted.

Pumping the sewage sludge can  work if the sewage
sludge is liquid enough. Below 10%  to 15% solids, most
sewage sludge flows as a semi-solid and can be fed through
a pump. Higher solids concentrations restrict or eliminate the
flow of sewage sludge to the pump. Centrifugal pumps can
                          be used for dilute sewage sludge (<10% to 13% solids),
                          or chopper-type centrifugal pumps may be able to pump
                          sewage sludge of up to 15% solids. If dewatered sewage
                          sludge (>15%) is brought to the site and a pump is to be
                          used to transfer the sludge,  water must be added  and
                          mixed with the sewage sludge before pumping is possible.


                          8.6.2  Application Equipment

                          There are four general types of methods for applying
                          sewage sludge to forests: (1) direct spreading; (2) spray
                          irrigation with either a set system or a traveling gun; (3)
                          spray application by an application vehicle with a spray
                          cannon; and (4) application by a manure-type  spreader.
                          The main criteria used in choosing a system is the liquid
                          content of the sewage sludge. Methods 1, 2, and 3 are
                          effective for liquid  sewage sludge (2% to  8%  solids);
                          Methods 1 and 2 can be used for semi-solid sewage
                          sludge (8% to 18% solids); and only Method 4  is accept-
                          able for solid sewage sludge (20% to 40% solids). Table
                          8-4 lists these  methods, their range of application, rela-
                          tive costs, and  advantages and disadvantages. The
                          method used by most municipalities  for forest applica-
                          tions is spray application  by  an application vehicle with
                          a mounted cannon,   although King  County  Metro in
                          Washington state  now applies a dewatered sewage
                          sludge with a throw spreader.

                          Many application vehicles have been developed for use in
                          agricultural applications.  Most of these can be readily
                          modified for forest use by mounting a spray nozzle and
                          pump on the tank. Application vehicles can also be custom
                          made. Depending on the site needs, a specially designed
                          all-terrain vehicle can  be  used. In some cases, a used
                          heavy-duty truck chassis with a rear-mounted tank has
                          been modified for forest use.  The application vehicle can
                          either be filled  by a traveling tanker, directly from on-site
                          storage, or can itself be  an over-the-road multi-purpose
                          (transport/application)  vehicle. Once full, the application
                          vehicle moves into the forest over the roads or trails and
Table 8-4. Comparison of Different Application Systems for Forest Sites (Henry, 1991)

System and Range              Relative Costs          Advantages
                                                 Disadvantages
Sludge spreading and
incorporation range = 10' (3 m)

Spray irrigation:
   Set irrigation systems
   range = 30' - 200'

   Traveling big gun
   range = 200'
Low capital and O&M


High capital, low O&M
Moderate capital, low
O&M
Simple to operate; any
solids

Simple to operate
Simple to operate on
appropriate sites
Need cleared site; difficult plantation
establishment with some species

Frequent clogging; use only low %
solids; brush interferes
Frequent clogging; use only low %
solids; brush interferes
Application vehicle with
mounted cannon range = 125'

Manure-type spreader
range = 50'-200'
Low-moderate capital,
high O&M

Low capital and O&M
Any terrain; sludge up to
18% solids

Only effective way to apply
high % solids sludge
May need special trails


Limited to high % solids; trails may
need to be close together
O&M = operation and maintenance costs.
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unloads the sewage sludge in uniform thin layers while
the vehicle is either moving or stationary.

Considerations for  on-site storage are  discussed in
Chapter 14.

8.7   Scheduling

Sewage sludge applications to forest sites can be made
either annually or once  every several years. Annual
applications are designed to  provide  N only for the
annual uptake  requirements of the trees, considering
volatilization and denitrification  losses and  mineraliza-
tion from current and prior years. An application one
year followed by a  number of years when no applica-
tions are made utilizes soil storage (immobilization) of
nitrogen to temporarily tie up excess nitrogen that will
become available in later years.

In a multiple-year (e.g., every 3 to 5 years) application
system, the forest  floor,  vegetation, and soil have a
prolonged period to  return to normal conditions, and the
public can use the site for recreation in the non-applied
years.  Application rates, however, are not simply an
annual rate multiplied by the number of years  before
reapplication, but rather need to be calculated so that
no NO§ leaching occurs.  If the sewage sludge is quite
liquid  (<5% solids), annual applications  may be  pre-
ferred, since the water included with heavier applications
at low percent solids may exceed the soil's infiltration rate.
In this case surface sealing may  occur, increasing the
potential for runoff as well  as anaerobic conditions, which
can cause odor problems or stress  the plants.

For liquid and  semi-liquid sewage sludge, if the  total
depth of an application is to  be greater than approxi-
mately one-quarter of an inch, it is recommended that a
series  of three or more  partial applications  (with the
number depending on the percent solids of the sludge)
be made rather than one heavy application. This prac-
tice allows more even applications to be made, provides
time for stabilization or drying of the sewage sludge to
occur, and is important for maintaining infiltration and con-
trolling runoff. The "rest" between applications will range
from 2 to 14 days depending on weather conditions.

Scheduling sewage sludge application  also requires a
consideration of climatic conditions and the age of the
forest. High rainfall  periods and/or freezing conditions
can limit sewage sludge applications in almost all situ-
ations. The  Part 503 regulation prohibits bulk sewage
sludge from being applied to forest land that is flooded,
frozen, or snow-covered  so  that the sewage sludge
enters a wetlands or other surface waters. In addition,
vehicle access  to steeper soils could potentially be too
difficult during the wet parts of the  year. As discussed in
Section 8.5.1.2, all applications to young  plantations
should be done when the trees are dormant (e.g., during
the late fall, winter, and early spring).
An application schedule for a 1-year period is shown in
Table 8-5 for a design in the Pacific Northwest. Using
such a schedule, it would be feasible to avoid the need
for storage, especially when alternative  management
schemes are available. On-site storage, however, may
also  be desirable.
Table 8-5.
         Monthly Application Schedule for a Design in the
         Pacific Northwest
               Glacial Soil
                                    Residual Soil
           Young      Established Young     Established
Month      Plantation   Forest     Plantation  Forest
January
February
March
April
May
June
July
August
September
October
November
December
Aa
A
A
NA
NA
NA
NA
NA
NA
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
LA
LA
LA
NA
NA
NA
NA
NA
NA
LA
LA
LA
LA
LA
LA
A
A
A
A
A
A
LA
LA
LA
 Abbreviations:
 A  =Site available, no limitations.
 NA = Not available, damage will be caused by sludge on growing
     foliage.
 LA = Limited availably, periods of extended rain are to be
     avoided due to vehicle access problems

8.8   Determining Sewage Sludge
      Application Rates for Forest Sites

8.8.1   General

As with agricultural lands, sewage sludge application
rates at forest sites usually are based on tree N require-
ments. As discussed  below, nitrogen dynamics of forest
systems are somewhat more complex than agricultural
systems because of recycling of nutrients in  decaying
litterfall, twigs and branches, and the immobilization of
the MM} contained in sludge as a result of decomposition
of these materials. As with agricultural applications, con-
centrations of trace elements (metals) in some sewage
sludges may limit the cumulative  amount of sewage
sludge that can be placed  on  a particular area (see
Chapter?, Section 7.4.4.3).

8.8.2   Nitrogen Uptake and Dynamics in
        Forests

In general, uptake and storage of nutrients by forests
can be as  large as that of agricultural crops if the system
is correctly managed  and  species are  selected that
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respond to sewage sludge. The trees and  understory
utilize the available N from sewage sludge, resulting in
an increase in growth. There  is a significant difference
between tree species in their uptake of available N. In
addition, there is a large difference between the N up-
take by seedlings, vigorously growing trees, and mature
trees. (One study found that in  young Douglas-fir, uptake
can be  up to 100 Ib-N/ac/yr when the trees fully occupy
the site, but as low as  25 Ib-N/ac/yr in  old Douglas-fir
stands  [Dyck et al., 1984]). Finally, the amount of vege-
tative understory on the  forest floor will affect the uptake
of N; dense understory vegetation markedly increases
N uptake.

Table 8-6 provides estimates of annual N uptake by the
overstory and understory vegetation of fully established
and vigorously growing forest ecosystems in selected re-

Table 8-6.  Estimated Annual  Nitrogen Removal
          by Forest Types
Forest Type
Tree Age    Average N Uptake

 (years)    (Ib/ac/yr)  (kg/ha/yr)
Eastern Forests
(Irrigated Wastewater)
Mixed Hardwoods              40-60
Red Pine                       25
Old Field with White              15
   Spruce Plantation
Pioneer Succession             5-15
Aspen Sprouts

Southern Forests
(Irrigated Wastewater)
Mixed Hardwoods              40-60
Southern Pine with No            20
   Understory
   (mainly Loblolly)
Southern Pine with               20
   Understory
   (mainly Loblolly)

Lake  States Forests
(Irrigated Wastewater)
Mixed Hardwoods                50
Hybrid Poplar3                   20

Western Forests
Irrigated Wastewater
   Hybrid Poplar               4-5
   Douglas Fir Plantation        15-25
Sludge Application
   Hybrid cottonwood              5
   Young Douglas-fir, 100%       7-15
   site occupied
   Older Douglas-fir             >40
   Understory, first
   application13
   Understory, reapplications
                      200
                      100
                      200

                      200
                      100
                      280
                      200


                      260
                      100
                      150
                      300
                      200
             250
             100

              45
             100
Sources: Stone  (1968)  for irrigated wastewater sites; Henry  (see
 footnote 1) for western sludge application.
a Short-term rotation with harvesting at 4 to 5 years; represents first
 growth cycle from planted seedlings.
b Adjust by  % site covered.
gions of the United States. The reported average annual
N  uptakes vary from 106 to 300 kg/ha/year (89 to 267
Ib/ac/year), depending on species, age, etc. Note that all
of the trees listed in the table are at least 5 years old, and
that during initial stages of growth, tree seedlings will have
relatively lower N uptake rates than shown.

Calculation of sewage sludge application rates to supply
plant N requirements is somewhat more complicated
than for agricultural crops because the following  nitro-
gen transformations need to be considered in addition
to N mineralization and  ammonia volatilization from the
sewage sludge: (1) denitrification, (2) uptake by under-
story, and (3)  soil immobilization for enhancement of
forest  soil organic-N  (ON)  pools.  Table 8-7  presents
ranges of values and suggested design values for nitro-
gen transformations and losses from  sewage sludge
applied to forest environments. The discussion below
focuses on major aspects of nitrogen dynamics in forest
ecosystems.

8.8.2.1    Nitrogen Mineralization

Mineralization  (transformation of organic  N to NHjj)  oc-
curs when the organics in sewage sludge decompose,
releasing  NHjf. Typical values for N mineralization for the
first year can  be quite  variable, ranging from 10% to
50% or more. A recent study conducted on a number of
sewage sludges from Oregon found that N mineralization

Table 8-7.  Ranges of Values and Suggested Design Values
          for Nitrogen Transformations and Losses From
          Sewage Sludge  Applied to Forest Environments
          (Henry,  1993)
Transformation/Loss Design Value
Range
Suggested
Nitrogen Mineralization

Anaerobically digested              20% - 65%
   short detention                                 40%
   long detention                                 20%

Lagooned                        10%-20%
   short detention                                 20%
   long detention                                 10%

Composted                       5% - 50%
   mixed or with short detention                     40%
   long detention, fully cured                        10%

Ammonia Volatilization             0% - 25%

Open stand                                      10%
Closed stand                                      0%

Denitrification

Moist soils much of year                            10%
Dry soils                                          0%

Soil Immobilization               0 -  1,000 Ib/ac

First application
   young stand                                 100 Ib/ac
   old stand                                    0 Ib/ac
Reapplications                                  0 Ib/ac

Plant Uptake  (see Table 8-6)
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ranged  from 20% to 65% for anaerobically digested
sewage sludge,  15%  to  19% for lagooned  sewage
sludge,  and 36% to 50% for short-detention composted
sewage sludge for the first year.3 Table 8-7 gives ranges
and typical values for mineralization of sewage sludge
applied  to forest sites. Because mineralization of differ-
ent sewage sludge varies so much, it  is recommended
that  mineralization studies be conducted  on  specific
sewage sludge.

8.8.2.2   Ammonia Volatilization

Volatilization losses (when  NHJ; escapes to the atmos-
phere) from sewage  sludge surface-applied to agricul-
tural soils have been  measured from 10% to 60% of the
initial NHjf, and a  typical design number is 50%. Forest
environments, however, probably lose considerably less
than this due to the  low pH of the forest floor, the low
wind speed in forest stands, and less radiation reaching
the forest floor. Measurements taken both in  western
and eastern Washington forests which were fairly open
range from 10% of the  initial NHJ; being lost with a light
liquid application (dry site) (Henry and Zabowski, 1990),
25% in a western Washington  forest with a closed can-
opy,  and  35%  lost in  an  open older forest stand in
western Washington.4 Current  work in  British Columbia
with  surface applications to hybrid poplar plantations
suggests losses ranging from 25% to 100% of the initial
MM}.5 Suggested  conservative values in Table 8-7 are
10% in  open stands and no ammonia volatilization in
closed stands.

8.8.2.3   Denitrification

Excess  MM} not taken up by the vegetation or  immobi-
lized by the soil will in most cases microbially transform
into nitrate. When there is little oxygen in the soil, some
of the NO§ can be lost to the atmosphere as N2 or N2O,
a process called denitrification. Depending on soil con-
ditions, denitrification losses up to 25 percent of the total
can occur (U.S. EPA, 1983). Measurements taken  in a
dry eastern Washington forest  showed no denitrification
(Henry  and Zabowski, 1990),  while in  a  well  drained
western forest about 10% denitrification was predicted
(Coles et al., 1992).  Table 8-7 contains  suggested val-
ues for denitrification.

8.8.2.4   Soil Immobilization  Rates

Immobilization is the transformation of NHJ; into organic-
N  by soil microbes.  Because forest  soils include an
organic layer containing decaying litterfall, twigs,  and
 Henry, C., A. Haub, and  R. Harrison.  Mineralization of sewage
 sludge nitrogen from six Oregon cities. Draft report.
4 See footnote 1.
5Van Ham, M., and C. Henry. 1995. Personal communication be-
 tween M. Van Ham and C. Henry, Pack Forest Research Center,
 University of Washington, Eatonville, WA.
branches, the soil may have  a lot of excess organic
carbon  both  in the  forest floor and  the  surface  soil
horizons. When this carbon decomposes, it uses some
of the available N. This immobilization represents long-
term soil storage of nitrogen that will be re-released (min-
eralized) at a very slow rate. Depending on the amount of
carbon and whether the site has been fertilized before,
immobilization can be up to 1,100 kg/ha (Henry,  1991). A
young stand with  a good forest floor, however,  probably
will  immobilize in the neighborhood of 220 kg/ha.

When sewage sludge is re-applied, little additional N will
be  immobilized  unless  the  previous  application was
made many years before. Table 8-7 contains suggested
values for immobilization.  Overestimation of N  immobi-
lization at forest sites can result in sewage sludge appli-
cation rates that significantly exceed tree N requirements.
Consequently, estimates of immobilization should either
be set very conservatively or based on sewage sludge
field studies that document the increase of soil  organic-
N from different horizons.

The carbon to nitrogen ratios (C:N) of the forest floor and
surface soil  horizons can serve as indicators of the
potential for soil immobilization  of N from sewage sludge
applied to forest sites (excluding large woody debris that
decompose slowly).  Generally, when  the  C:N ratio is
greater than 20-30:1, immobilization will occur. Woody
materials generally have much higher ratios (often ex-
ceeding 70:1).  When sewage sludge is  applied,  the
available N allows microbial  populations to expand rap-
idly and decomposes the soil organic matter, temporarily
locking  up the N  in microbial  biomass or  in long-term
stable  humic acids.  The  N  incorporated  into  the  cell
structure of the microorganisms can eventually be re-
leased gradually as they die off.
8.8.2.5   Nitrogen Leaching


Typically, N  is the limiting constituent for land applica-
tions  of sewage  sludge because when excess  N is
applied, it often results in nitrate leaching. The N avail-
able from sewage sludge addition can be microbially
transformed into NOs through a process known as nitri-
fication. Because NO§ is negatively  charged, it easily
leaches to the ground water with percolating rainfall. A
number of studies conducted at the University of Wash-
ington's Pack Forest Research Center confirmed that
heavy applications of N resulted in substantial increases
of NO§ in the ground water (Riekirk and Cole, 1976; Vogt
etal., 1980).6'7
 Henry, C., R. King, and R. Harrison. Distribution of nitrate leaching
 from application of municipal biosolids to Douglas-fir. Draft report.
7 Henry, C., and D.  Cole. Nitrate leaching from fertilization of three
 Douglas-fir stands with municipal biosolids. Draft report.
                                                   102

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8.8.2.6   Effects of Temperature on Nitrogen
         Dynamics
In northern climates where winter soil temperatures are
low, transformations caused by microbial action in soil
slow down considerably. For  instance,  when the soil
temperature decreases about  18°F, microbial action is
about half as fast. At about 40°F microbial action essen-
tially stops. Through much of the winter the average
temperature of the soil may be at or below 40°F under
forest stands in northern parts of the United States. This
means that mineralization, nitrification, and denitrifica-
tion essentially stop. Thus, the nutrients from land appli-
cation  of sewage sludge  made during  the winter will
essentially be  stored in the forest floor and soil layers
until temperatures increase. Thus, NO§ leaching will not
significantly occur from  winter  applications  because
NO§ will not be formed.

8.8.3  Calculation Based on Nitrogen for a
       Given Year
The calculation for the application  rate  at forest  sites
based on N for a given year involves determining site N
requirements and available N in the sewage sludge. A
site's net N needs are the sum of the N uptake by trees
and understory and soil immobilization of N:
   Nreq = Utr + UUs + SI
                                           (8-1)
   where:
   Nreq

   Utr
   Uus
   SI
          N requirements to be supplied by a given
          application of sewage sludge, kg/ha
          N uptake,  by trees,  kg/ha (Table 8-6)
          N uptake by understory, kg/ha (Table 8-6)
          N immobilization in soil from initial sew-
          age sludge application, kg/ha (Table 8-7)
The requirements for N are met by: 1) the N mineralized
from previous applications, and 2) the N supplied by the
current  application of sewage sludge (NHjf, NO§ and
mineralized  ON). Organic-N is converted to NHJ; rela-
tively rapidly during the first year. In future years, the
remaining organic matter becomes more and more re-
calcitrant (does not decompose as easily) and ON min-
eralization  is  much  reduced. Without  local data on
mineralization  rates, it is recommended that ON miner-
alization be  ignored beyond three years after applica-
tion. The  N supplied  from  previous  applications is
calculated as shown in equation 8-2.
N
  prev
where:
Nprev
            {(Si)(ONi)(1-Ko)(Ki)
            (S2)(ON2)(1-Ko)(1-Ki)(K2)
            (S3)(ON3)(1-Ko)(1-Ki)(1-K2)(K3)}1 ,000
                                           (8-2)
 Si,2,etc.   =  Sewage sludge application rate 1, 2,
             etc. years ago, t/ha
 ONi,2,etc. =  Percent N in sewage sludge 1, 2, etc.
             years ago, expressed as a fraction
 Ki,2,etc.   =  Mineralization  rate of ON 1, 2, etc.
             years after the year of application, ex-
             pressed as a fraction

The amount of N available the year of application from
a ton of the sewage sludge (PAN) is calculated  from
equation 8-3.

   PAN = {(AN)(1-V) + NN +  (ONo)(Ko)}(1-D)(10)  (8-3)

   where:
   PAN   = Total  plant available nitrogen, kg/ton
   AN    = Percent NH^-N in sewage sludge as ap-
            plied, %
   NN    = Percent NO§-N in sewage sludge as ap-
            plied, %
   ONo   = Percent ON in sewage sludge as applied, %
   Ko     = Mineralization rate of ON during the year
            of application, expressed  as a fraction
   V      = Loss  of ammonia by volatilization, ex-
            pressed as a fraction
   D      = Loss  of N  by denitrification, expressed
            as  a fraction

The sewage sludge application rate to supply a given
year's N requirement is then calculated  from the pre-
vious two equations:
   So = (Nreq - Nprev)/PAN
(8-4)
Table 8-8 provides some example calculations for a young
plantation and older stand of Douglas-fir.  In comparing

Table 8-8.   Example First-year Application Rate for Sewage
          Sludge Based on Available Nitrogen for Two
          Different Types of Douglas-fir Stands
            Total mineralized N from sewage sludge
            applications in previous years, kg/ha
Assumptions
Uptake by trees, Utr (kg/ha)
Uptake by understory, Uus (kg/ha)
Soil immobilization, SI (kg/ha)
N required, Nreq (kg/ha) (Eq. 8-1)
N mineralization, previous sewage sludge
app., Nprev (kg/ha) (Eq. 8-2; no
previous application)
Initial ammonia-N, AN (%)
Initial nitrate-N, NN (%)
Initial organic-N, ON (%)
Fraction of ON mineralized, Kg (g/g)
Fraction of ammonia volatilized, V (g/g)
Fraction of N lost to denitrification, D (g/g)
Plant available N, PAN (kg/t) (Eq. 8-3)
Sewage sludge application rate,
S0 (t/ha) (Eq. 8-4)
Young
Stand
112
101
224
437
0
1.0
0.0
4.0
.25
.25
.25
17.5
33.3
Older
Stand
50
28
56
134
0
1.0
0.0
4.0
.25
.10
.10
19.0
7.8
                                                   103

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these cases, note that total N requirements are higher
for the young stand than the older stand (390 Ib/ac vs
120 Ib/ac), and available N in the sewage sludge is lower
in the younger stand due to higher losses from volatili-
zation and denitrification (26.3 Ib/ac vs 34.2 Ib/ac for the
older stand). Consequently there is a large difference in
sewage sludge application rates to meet N requirements
in the two stands: 14.8 T/ac for the younger stand and
3.5 T/ac for the older stand.
8.8.4  Calculation of Sewage Sludge
       Application Rates for First and
       Subsequent Years

The sewage sludge application rate  in any given year
involves N budget calculations  using  procedures de-
scribed in Section 8.8.3 so  as  not  to exceed  site  N
uptake requirements. Although the basic approach is the
same for any year's application, special considerations
in performing the N budget analysis will vary somewhat
depending on  whether it is an initial application, and
whether subsequent applications are done annually  or
periodically (i.e., intervals exceeding one year).

A key consideration in the  N  budget for an initial appli-
cation is determination of the amount of N in the sewage
sludge that will be immobilized by the soil (SI in Equation
8-1). Sewage sludge additions will build up the soil N
pools to the point that an equilibrium will eventually exist
between soil N mineralization and immobilization. Thus,
for subsequent annual applications, it should be as-
sumed that  there  will  be  no additional  soil immobi-
lization. In fact, unless site-specific data documenting  its
existence is  available,  it is  prudent to assume no addi-
tional soil immobilization unless the last application was
made a considerable time in the  past (>5-10 years).

The main difference between periodic applications com-
pared to annual applications is that cumulative applica-
tions over the same time period  will be lower because
the N available from mineralization of previous sewage
sludge applications will generally be less than the po-
tential N  uptake by trees  in the years when sewage
sludge is not applied. This  means that more total forest
acreage will generally  be  required  for utilization  of a
given amount  of sewage sludge compared to annual
applications.


8.8.5  Calculation Based on Part 503
       Pollutant Limits for Metals

The same Part 503 pollutant limits for metals that pertain
to sewage sludge  application at agricultural  sites,  as
discussed in Chapter 7, also apply to forest sites  (see
Chapter 3 for a discussion  of pollutant limits).
8.9   Design Example of Sewage Sludge
      Application at Forest Sites

This design example was developed in part to demon-
strate the procedures  needed to ensure protection  of
drinking water aquifers during an annual sewage sludge
land application program. The criteria used for an annual
sewage sludge land application project at a forest site are:

1.  Nitrogen applications cannot exceed the ability of the
forest plants to utilize  the N applied, with appropriate
adjustments for losses.

2.  Cumulative metal loading limits  cannot exceed the
cumulative pollutant loading rates (CPLRs), if applicable
(see Chapter  3), in the Part 503 rule.

8.9.1  Sewage Sludge Quantity and Quality
       Assumptions

The sewage sludge generated by the hypothetical com-
munity in this design example is assumed to have the
following average  characteristics:

• Anaerobically digested  sewage sludge is generated
  on the average  of 18.2 t/day (20  T/day), dry weight,
  by an activated  sludge  sewage treatment plant.

• Liquid sewage sludge  averages 4 percent  solids  by
  weight; its volume is  445,600 L/day (117,600 gal/day).

• Average sewage sludge analysis on a dry weight basis
  is the same as the design example for agricultural ap-
  plications (see Chapter 7 for metals concentrations):
  -  Organic-N (ON) = 2.5 percent  by weight.
  -  Ammonia-N (AN)  = 1 percent by weight.
  -  Nitrate-N (NN) = none.

8.9.2  Site Selection

The  hypothetical community for this design example is
located  in the Pacific  Northwest. A large commercial
forest is located 24 km (15 mi) from the sewage treat-
ment plant. The site owner believes  that he can expect
a significant increase in tree growth rate resulting  from
the nutrients  in sewage sludge. Preliminary  investiga-
tions of the owner's property show that a total of 3,000  ha
(7,400 ac) are  available, of which 1,200 ha (3,000 ac) have
the following desirable characteristics:

• Convenient  vehicle  access  to  public and private
  roads, plus an   in-place  network of  logging roads
  within the area.

• No surface waters used for drinking or recreational
  purposes are located within  the  area. Intermittent
  stream locations are mapped, and 90-m (290-ft) (or
  greater)  buffer  zones  can be readily established
  around the  stream beds.
                                                 104

-------
• Ground water under one portion of the site has the
  potential to serve as a drinking water aquifer.

• Public access is limited by signs and fences adjacent
  to public roads.

• Topography is satisfactory,  in that the area consists
  largely of slopes less than 6 percent,  and slopes
  steeper than 30 percent can be readily excluded from
  the sewage sludge application program.

• There are  no  residential dwelling units within the area.

• The area  is roughly  equally divided between  young
  hybrid poplar that is harvested on  a  5-year rotation
  and an established stand of Douglas-fir. However, the
  1,200 ha  (3,000 ac)  area contains 200 ha (500 ac)
  that either contain tree species that are incompatible
  with sewage sludge applications  (e.g., they fix nitro-
  gen) or have slopes exceeding 30%. These areas are
  excluded.
                                                      Table 8-9.
Year
         N Requirements for Sewage Sludge Application to
         Hybrid Poplar and Established Douglas-fir
         Plantations
                 N,,
    kg/ha
N,,
                                     SI
                                              N
                                               req
Hybrid poplar
1995
1996
1997
1998
1999
Douglas-fir
1995
1996
1997
1998
1999

50
100
150
200
250

100
100
100
100
100

100
50
0
0
0

100
0
0
0
0

100
0
0
0
0

150
0
0
0
0

250
150
150
200
250

350
100
100
100
100
8.9.2.1   Soil and Hydrological Properties of the Site

The soils are of two types: glacial outwash, and residual
soil developed from andesitic bedrock. The glacial out-
wash is located largely on terraces with slopes less than
10 percent. Infiltration is rapid. The soil pH ranges be-
tween 5.5 and 6.0, and CEC is 14 meq/100 g. A2.5-cm
to 5.0-cm (1-in to 2-in) litter layer exists in the  estab-
lished forest. The ground water table is approximately 9 m
(30 ft) below the soil surface. Residual soil is found on
slopes ranging up to 40 percent. Slopes steeper than 30
percent were  eliminated from further consideration.

8.9.3  Determining the Sewage Sludge
       Application Rate Based on Nitrogen

For this  design  example,  assume  that  the  sewage
sludge is to be land applied on an annual basis, and that
the quantity of sewage sludge applied is limited by N.
The purpose of the calculation is to have the plant-available
N in the applied sewage sludge equal the N uptake of the
trees and understory, accounting for assumed  atmos-
pheric losses discussed in Section 8.8.3. This is  a con-
servative  approach  intended  to prevent  leaching  of
nitrate to the ground water aquifer.

Step 1. Calculate Net N  Requirements  for First 5
        Years

N requirements for the hybrid poplar and the Douglas-fir
stands are calculated separately for the  first 5 years
using Equation 8-1. Table 8-9 summarizes the assump-
tions used to calculate net N requirements.  For the
hybrid  poplar tree, N uptake is assumed to gradually
increase, from 50 kg N/ha in the first year to 250 kg N/ha
in the fifth year. Uptake of the understory is 100 kg N/ha
in the first year and 50 kg N/ha in the second year, and
is assumed to be negligible in subsequent years. The
amount of N immobilized as a result of decomposition
of soil organic carbon is assumed to be 100 kg/ha in the
first year and 0 in subsequent years. Table 8-9 shows a
high N need for the poplar of 250 kg/ha in the first year,
which drops to 100 kg/ha in the second year, and gradu-
ally increases back to 250 kg/ha by the fifth year.

Initial N required  for the Douglas-fir stand is higher than
for the hybrid poplar (350 kg/ha) because of higher initial
N uptake by trees (100 kg/ha)  and higher N immobi-
lization  (150 kg/ha) because of higher initial litter/soil
organic carbon content. Understory uptake in the first
year was assumed to be the same  as for the hybrid
poplar (100 kg/ha). In subsequent years, N uptake by
trees is assumed to  remain steady at  100 kg/ha,
whereas N  uptake by the understory and immobilization
is assumed to be negligible. The net effect of these
assumptions is that  the  N needs for the Douglas-fir
stand in the second through fifth years remain steady at
100 kg/ha,  as shown  in Table  8-9.

Step 2. Calculate  Initial  Available N  in  Sewage
         Sludge for Each Year

Available N in the sewage sludge needs to be calculated
for each forest stand type, and recalculated for any year
in which changing site conditions may affect N availabil-
ity. In the first two years surface application is made to
a very open stand where  both heat and wind  reach the
soil surface, thus volatilization can be high (assumed to
be 0.5), but since the soils are well drained, denitrifica-
tion is low (assumed  to be 0.1). Mineralization rate for
this first year is taken from Table 7-7 in Chapter 7 in the
column  for anaerobically treated sewage sludge. N
availability  from  sewage  sludge applied to the hybrid
poplar plantation for  the  first year is calculated using
Equation 8-3 as follows:
                                                  105

-------
PANi,2 =  {(AN)(1-V) + NN
       =  {(1.0)(1-0.5) + 0
       =  9.0 kg/t
                               (ONo)(K0)}(1-D)(10)
                               (2. 5)(0.20)}(1-0.1)(10)
                                                    Table 8-10.  Sewage Sludge Application Rates to Meet N
                                                               Requirements at Forest Sites
During the following years, the trees reduce both radia-
tion and wind reaching the soil surface, so ammonia
volatilization  is assumed to be reduced to 0.25, while
denitrification remains relatively constant at 0.1.
PANs-5=
                      NN
                      + 0
                               (ON0)(K0)}(1-D)(10)
                               (2.5)(0.20)}(1 -
          =  11.3 kg/t
Available N from sewage sludge applied to the Douglas-
fir stand will be 1 1 .3 kg/t for all 5 years because the wind
and heat reaching the forest floor are presumed to be very
similar to the third year conditions in the poplar stand.

Step 3. Calculate First-Year Sewage Sludge
       Application Rate

First-year sewage sludge application rates to forest sites
can be  substantially higher than  in subsequent  years
because of the  initial response of understory growth,
which increases N uptake, and immobilization of N,  as
discussed in Section 8.8.2; no mineralization of ON from
previous applications occurs. The  initial sewage sludge
application rate is calculated using Equation 8-4:

   SO     =  (Nreq - Nprev)/PAN
          =  (250 - 0)/9.0
          =  28 t/ha(for the hybrid poplar)

          =  (350 - 0)/11.3
          =  31  t/ha(for the Douglas-fir)

Step 4. Calculate Sewage Sludge Application Rates
       for Subsequent Years

Sewage sludge application rates for subsequent  years
must take into account mineralization of organic N from
previous sewage sludge applications. Table 8-10 shows
the results of mineralization calculations for the second
through fifth  years. In this example, the second-year
sewage sludge  application rate to supply N require-
ments of the  hybrid poplars drops from 27.8 t/ha to  12
Year
t/ha
Hybrid poplar
1995
1996
1997
1998
1999
Douglas-fir
1995
1996
1997
1998
1999
Nreq

250
150
150
200
250

350
100
100
100
100
N
i>"prev

0
42
32
35
33

0
46
23
27
15
PAN

9
9
11.3
11.3
11.3

11.3
11.3
11.3
11.3
11.3
S
S0 (cumulative)

27.8
12.0
10.4
14.6
19.2

31.0
4.7
6.8
6.4
7.5

28
40
50
65
84

31
36
43
49
56
                                                     Notes:
                                                      Nreq = N requirements to be supplied by a given application of
                                                      sewage sludge, kg/ha
                                                      Nprev  = Total mineralized N from sewage sludge applications in
                                                      previous years, kg/ha
                                                      PAN = Total plant nitrogen, kg/ton
                                                      SQ = Sewage sludge application rate for a given year
                                                      S = Sewage sludge application (cumulative)
                                                    t/ha and then gradually increases to 19.2 t/ha in the fifth
                                                    year. The Douglas-fir stand shows an even more dra-
                                                    matic drop from 31 t/ha in the first year to 4.7 t/ha in the
                                                    second year. The third year application rate for Douglas-fir
                                                    increases to 6.8 t/ha, with slight additional increases to 6.4
                                                    and 7.5 t/ha for the fourth and fifth years, respectively.

                                                    8.9.4  Site Capacity Based on Nitrogen

                                                    The design example site has  1,000 ha (2,471  ac) suit-
                                                    able for sewage  sludge  application, which is roughly
                                                    equally divided between established Douglas-fir forest
                                                    and the hybrid  poplar plantation (assume 500 ha [1,235
                                                    ac] of each). The quantity of sewage sludge that can be
                                                    applied during  the first  5  years is summarized in Table
                                                    8-11. Total application in the first year could be as high as
                                                    29,400 t. In the second year this drops to  8,400 t,  and
                                                    gradually increases to 13,3001 by the fifth year.
Table 8-11.  Maximum Annual Sewage Sludge Application Based on N Requirements
Year
1995
1996
1997
1998
1999
Area
(ha)
500
500
500
500
500
Hybrid
(t/ha)
27.8
12.0
10.4
14.6
19.2
Poplar
(t)
13,900
6,000
5,200
7,300
9,600

(t/ha)
31.0
4.7
6.8
6.4
7.5
Douglas Fir
(t)
15,500
2,400
3,400
3,200
3,700
Total
(t)
29,400
8,400
8,600
10,200
13,300
t = metric tonnes.
                                                    106

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Since the community generates 18.2 t/day (20 T/day),
dry weight  of sewage  sludge,  or 6,643 t/year (7,307
T/year), this would supply sewage sludge applied at the
first year design rate of only one-fourth of the site. This
scenario also requires less than the entire site for reap-
plication (at the lesser rates of years 2-5). Therefore, the
hypothetical site appears to be of quite sufficient area.
However, careful planning and record  keeping will  be
required to schedule the amount and location  of sewage
sludge applications to maintain  a good  program.
8.10  References
Coles, J., C. Henry, and R. Harrison. 1992. Gaseous nitrogen losses
   from  three Douglas-fir stands after reapplication of municipal
   sludge. Agron. Abstr. American Society of Agronomy, Madison, Wl.

Dyck, W., S. Gower, R. Chapman-King, and D. van der Wai, 1984.
   Accumulation in aboveground biomass of Douglas-fir treated with
   municipal sewage sludge. (Draft Report.)

Henry, C. 1991. Nitrogen dynamics of pulp and paper sludge to forest
   soils. Water Sci. Tech.  24(3/4):417-425.

Henry, C., D. Cole, T.  Hinckley, and R. Harrison. 1993.  The use of
   municipal and pulp and paper sludges to increase production in
   forestry. J. Sus. For. 1:41-55.
Henry, C., and R. Harrison. 1991. Literature reviews on environmental
   effects of sludge management:  Trace metals, effects on wildlife
   and domestic animals, incinerator emissions and ash,  nitrogen,
   pathogens, and trace synthetic organics. Regional Sludge Man-
   agement Committee. University of Washington, Eatonville, WA.

Henry, C., and D. Zabowski. 1990. Nitrogen fertilization of Ponderosa
   pine: I. Gaseous losses of nitrogen. Agron. Abstr., American So-
   ciety of Agronomy, Madison, Wl.

Riekirk, H., and D. Cole. 1976. Chemistry of soil and ground water
   solutions associated with sludge applications. In: Edmonds,  R.,
   and D. Cole, eds. Use of dewatered sludge, as an amendment
   for forest growth, Vol. I. Center for Ecosystem Studies, College of
   Forest Resources, University of Washington, Eatonville, WA.

Sopper, W.  1993. Municipal sludge use  in land  reclamation. Boca
   Raton, FL: Lewis Publishers.

Stone, E.L. 1968. Microelement nutrition of forest trees: A review. In:
   Forest  fertilization—Theory and practice.  Tennessee  Valley
   Authority,  Muscle Shoals, Al. pp. 132-175.

U.S. EPA. 1984. Environmental regulations and technology: Use and
   disposal  of municipal  wastewater  sludge. EPA/625/10-84/003.
   Washington, DC.

U.S. EPA. 1983. Process design manual: Land application of munici-
   pal sludge. EPA/625/1-83/016.

Vogt, K., R. Edmonds, and D. Vogt.  1980. Regulation of nitrate levels
   in sludge, soil and ground water. In: Edmonds, R., and D. Cole,
   eds. Use of dewatered sludge as an amendment for forest growth,
   Vol. III. Institute for Forest Resources, University Washington, Ea-
   tonville, WA.
                                                          107

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                                                Chapter 9
                Process Design for Land Application at Reclamation Sites
9.1    General

This chapter presents design information for application
of sewage sludge to reclamation sites.1 It  is  assumed
that the preliminary planning discussed in earlier chap-
ters has been done, that a sewage sludge transportation
system has been selected, and  that reclamation sites
are potentially available within  a reasonable distance
from the treatment works. Primary emphasis is on the
revegetation of the reclamation site with grasses and/or
trees.  If future land use for agricultural production  is
planned, the  reader should also refer to  Chapter  7,
"Process Design for Agricultural Land Application Sites."

Extensive areas of disturbed land that can benefit from
reclamation exist throughout the United States  as a
result of mining for clay, gravel, sand, stone, phosphate,
coal,  and other  minerals. Also  fairly widespread are
construction areas (e.g., roadway cuts, borrow pits) and
areas where dredge spoils or fly ash have been depos-
ited (Sopper and Kerr, 1982). Other areas needing rec-
lamation include clear-cut and burned  forests,  shifting
sand dunes,  landfills,  and sites devastated by toxic
fumes. Some disturbed mining sites may be designated
as "Superfund"  sites,  and applicable  regulations may
pertain.

Disturbed land can result from both  surface and under-
ground mining operations, as well as the deposition  of
ore processing wastes. The Soil Conservation Service
reported that as  of July 1, 1977, the minerals industry
had disturbed a total of 2.3 mil ha (5.7 mil ac), of which
about  50 percent was  associated with surface mining
(U.S. Soil Conservation Service, 1977). Only about one-
third of the disturbed areas was reported to have been
reclaimed. Table 9-1  presents the amount  of hectares
under permit for surface, underground, and other mining
operations during the  period 1977  to 1986.  Table 9-2
presents the  number  of hectares that have  been  re-
claimed with bonds released during 1977 to 1986—about
40 percent of the  land under permit (Sopper,  1993).

Most disturbed lands are difficult to revegetate. These
sites generally provide a  harsh  environment for seed
Table 9-1.  Hectares Under Permit for Surface, Underground,
          and Other Mining Operations From 1977 to 1986a
          (Sopper, 1993)
Year
                              Total Hectares
1978
1979
1980
1981
1982
1983
1984
1985
1986
Total
68,635
146,002
1 41 ,842
153,880
136,568
182,896
265,768
175,057
107,429
1 ,378,077
' States and Indian tribe lands included in above tabulations were Ala-
 bama, Alaska, Arkansas, Illinois, Indiana, Iowa,  Kansas, Kentucky,
 Louisiana, Maryland, Missouri, Montana, New Mexico, North Dakota,
 Ohio, Pennsylvania, Tennessee, Texas, Utah, Virginia, Washington,
 West Virginia, Wyoming, Crow Tribe, Hopi Tribe, Navajo Tribe.
Table 9-2.  Number of Hectares Reclaimed With Bonds Released
          During 1977 to 1986a (Sopper, 1993)
Year
                              Total Hectares
1978

1979

1980

1981

1982

1983

1984

1985

1986

Total
 19,078

 42,580

 51,401

 52,547

 80,351

 69,874

 96,910

 81,696

 68,280

562,717
 40 CFR Part 503 defines a reclamation site as drastically disturbed
 land that is reclaimed using sewage sludge (see Chapter 3).
 States and Indian tribe lands included in above tabulations were Ala-
 bama, Alaska, Arkansas, Illinois, Indiana, Iowa,  Kansas, Kentucky,
 Louisiana, Maryland, Missouri, Montana, New Mexico, North Dakota,
 Ohio, Pennsylvania, Tennessee, Texas, Utah, Virginia, Washington,
 West Virginia, Wyoming, Crow Tribe, Hopi Tribe, Navajo Tribe.
                                                     109

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germination  and subsequent  plant growth.  Major soil
problems may include a lack of nutrients and organic
matter, low pH, low water-holding capacity, low rates of
water infiltration and permeability, poor physical proper-
ties, and the presence of toxic levels of trace metals. To
correct these conditions, large applications of lime and
fertilizer may be required, and  organic soil amendments
and/or mulches also may be necessary.

Pilot- and full-scale demonstration projects have shown
that properly managed sewage sludge application is  a
feasible method  of reclaiming disturbed land and can
provide  a cost-effective option for sewage sludge use.
According to the 1990 NSSS, 65,800 dry metric tons per
year (1.2 percent of the sewage sludge used  or dis-
posed of annually) are used for land reclamation (58 FR
9257). Table 9-3 lists some of the more significant land
reclamation  projects  using sewage sludge during the
past 20 years.  Research  has shown that good  plant
cover can be established  on  many types of disturbed
lands using  sewage sludge, which is superior to inor-
ganic fertilizer for such uses  (Sopper, 1993). Sewage
sludge has been found to have a beneficial effect on the
establishment and growth of grass and legume species
on mine land (Sopper, 1993). In addition, the pH buffer-
ing  capacity  of sewage sludge makes it beneficial in the
reclamation of acidic sites  (Gschwind and Pietz, 1992).

At reclamation sites, sewage sludge application  usually
is performed once. The sewage sludge is not applied
again to the  same land area at periodic intervals in the
future, as is the case at agricultural  and forest sites.
Thus, most reclamation projects must have a continu-
ous supply of new disturbed land on which to apply
sewage sludge in future years. This additional disturbed
land may be created by ongoing mining or mineral proc-
essing operations or may  consist of presently existing
large  areas  of disturbed land which are gradually re-
claimed.  In either case,  an arrangement is  necessary
with the land owner to allow for future sewage sludge
land application throughout the life of the sewage sludge
land application project.

9.2  Consideration of Post-Sewage
      Sludge Application Land Use

If land application of sewage sludge is  used in the
reclamation  process,  it is important to consider federal
and state mining regulations  concerning  revegetation
(e.g., 30 CFR Parts 816  and 817)  and the federal Sur-
face Mining  Control and Reclamation Act (Public Law
95-87, Section 515) (U.S. Department of Interior, 1979;
Federal Register, 1982) and its amendments (54 FR 23).
Regulations  established  under this Act require that  a
diverse, effective, and permanent vegetative cover of
the  seasonal variety native to the affected land must be
established and  must be capable of  self-regeneration
and plant succession equal in coverage to the  natural
vegetation of the area (Federal Register, 1982). Before
beginning a  land  application  project  using  sewage
sludge at a reclamation site, the final use of the site after
it has  been  reclaimed must be considered regarding
compliance with these regulations. If the post-mining
land use is to be agricultural production or animal graz-
ing, agricultural land  application requirements for sew-
age sludge must be followed, such as the federal Part
503 regulation and any applicable state regulations. If
the site is to be vegetated primarily for erosion control,
a single large application of sewage sludge is desirable
for rapid establishment of the vegetative cover. Gener-
ally, Part 503 requirements for agricultural, forest, and
reclamation  sites are the same  (see Chapter 3). As
discussed in Section  9.3.1.1, the Part  503  regulation
specifies that for land  reclamation, the permitting author-
ity can  authorize a variance from the agronomic rate
requirement  for sewage sludge application.

In humid regions, a majority of the reclaimed mine areas
have been planted to forests. Some of these areas are
managed for lumber or pulp production, while others are
allowed to follow natural succession patterns. If the  re-
claimed area is to be turned into forest land, larger sewage
sludge application rates can  be considered than those
used for agricultural crops, since the products from the
forest are generally not a factor in the human food chain.
In all cases, post-mining land use must be considered prior
to the use of sewage sludge in land reclamation.

9.2.1   Mining Regulations

Prior to mining, a plan must be submitted to the appro-
priate agency stating the method of reclamation and
post-mining  land use. Amended regulations under the
Surface Mining Control and Reclamation Act issued in
1982 and 1988 set forth the following  requirements:

• The permanent vegetative  cover of  the area  must be
  at least equal in extent of cover to the natural vege-
  tation of the area and must achieve productivity levels
  comparable to unmined lands for the approved post-
  mining land use. Both native and introduced species
  may be used.

• The period of responsibility begins after the last year
  of augmented seeding, fertilization, irrigation, or other
  work that ensures  revegetation success.

• In areas of more than  26  inches of average annual
  precipitation, the period of extended responsibility will
  continue for not less than  5 years.  In areas with  26
  inches of precipitation or less, the period of respon-
  sibility will continue for  not less than 10 years.

• Normal husbandry  practices essential for plant estab-
  lishment would be  permitted  during the period of re-
  sponsibility  so  long as they can reasonably  be
  expected to continue after bond release.
                                                  110

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Table 9-3.  Recent Land Reclamation Projects With Municipal Sludge (Adapted From Sopper, 1993)




                                                        Sludge
Type of Disturbed Land
Acid strip mine spoil
Deep mine anthracite refuse
Acid strip mine spoil
Top-soil strip mine spoil (49 sites)

Zinc smelter site
Acid strip mine spoil
Abandoned Pyrite mine
Sandstone and siltstone mine soil
Non acid-forming overburden
Borrow pit
Acid strip mine spoil
Overburden minesoil

Iron ore tailings

Taconite tailings
Copper mine spoil
Copper mine
Borrow pit
Kaolin spoil
Marginal land
Acid stripmine spoil
Acid stripmine spoil


Reconstructed prime farmland
C and D canal dredge material


C and D canal dredge material

State
PA
PA
PA

PA
PA
VA
VA
VA
SC
WV
WV

Wl

Wl
CO
TN
GA
IL
KY


KY
MD


DE

Type3
Dig.-D + effluent
Dig.-D
Dig.-D, C

Dig.-D
Dig.-D, C/C
Dig.-D
Dig.-D
Dig.-D, C
Dig-D
Dig.-D, C
Dig.-D

Dig.-D

Dig.-D
Dig.-D
Dig.-D
Dig.-L
(Nl)


Dig.-D
Dig.-D


Dig.-D

Application Rates
(mg/ha)
5-20 cm
0, 40-150
134

47
120-134
82-260
22, 56, 112, 224
112
0, 17, 34, 68
Various (Nl)
0, 22.4, 44.8, 78.4

42-85

28-115
0, 30, 60
0, 34, 69, 275
0, 31-121
28-96


0, 22.4, 448
112


100

Plant/Animal Studied
Ryegrass
Hybrid poplar
1 0 tree spp.
5 Grass spp.
5 Legume spp.
Tall fescue
Orchard grass
Birdsfoot trefoil
Ryegrass
5 Grass species
5 Legume species
11 Tree species
Microorganisms
Tall fescue Lespedeza
Weeping lovegrass
Wheat, rye, oats
Tall fescue
Hay/pasture seed mix
Tall fescue
Sweetgum
Blueberries
Red clover
Tall fescue
Orchardgrass
Birdsfoot trefoil
5 Native prairie grasses
4 Prairie forbes
Foxtail
4 Grass-legume mixtures
Fourwing saltbush
Mountain big sagebrush
Pine species
Sweetgum
Tall fescue
Weeping lovegrass
European alder
Blacklocust
Cottonwood
Loblolly pine
Northern red oak
Grain sorgham
Corn
KY bluegrass
Tall fescue
Red fescue
Weeping lovegrass
Tall fescue
Red fescue
KY bluegrass
Parameters
Tested13
WA
GR
PA
SA
WA
GR
PA
SA
WA
GR
PA
SA
SO.SA
GR
PA
SA
WA
GR
SA.PA
SA
GR
PA
GR
PA
SA.PA
GR

GR

GR
GR.PA.SA
GR.SA
GR
WA
GR
PA
SA

GR
PA.SA
PA
SA
WA

PA
SA

                                                        111

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Table 9-3. (continued)
Type of Disturbed Land
                                                   Sludge
                             State
Type3
Application Rates
    (mg/ha)
                                                                         Plant/Animal Studied
                                                                                                 Parameters
                                                                                                  Tested13
Acid stripmine spoil              OH       Dig.-D


Degraded, Semiarid Grassland      NM       Dig.-D
                      11-716


                  0, 22.5, 45, 90
                   Tall fescue


                   Blue gamma
                   Galleta
                   Bottlebrush squirreltail
 GR.PA
 SA.WA

GR.PA.SA
Zn smelter surroundings


Lignite overburden
OK


TX
Dig.-L + effluent


Dig.-D
2.5-34 cm


56
10 grass spp.
1 legume

NA
GR
PA
SA
SA.WA
 Dig. = digested, L = liquid, D = dewatered, C = composted, C/C = dewatered cake and compost mix, Nl = no information.
b GR = growth responses, PA = plant tissue analysis, SA = soil analysis, WA = water analysis, SO = soil organisms, PO = pathogenic organisms,
 AH = animal health, NA = not applicable.
• In areas of more than 26 inches of precipitation, the
  vegetative cover and production of pasture, grazing
  land,  and cropland shall be equal to or exceed the
  success standard only during any 2 years except the
  first year. Areas approved for other uses shall equal
  or exceed success standards during the growing sea-
  son of the last  year of the responsibility period.  In
  areas with less  than 26 inches of precipitation, the
  vegetative cover must be equal to the success standard
  for at  least the last 2 years of the responsibility period.

• The ground cover, productivity, or tree stocking of the
  revegetated area shall  be considered equal to the
  success standards approved by the regulatory authority
  when  they are not less than 90 percent of the success
  standard with 90 percent statistical confidence.

Under the federal mining regulations, the potential post-
mining land use must be  of a level equal to or higher
than the pre-mining land use. Typical land uses include:

• Wilderness or unimproved use.

• Limited  agriculture  or recreation with  little develop-
  ment, such as forest land, grazing, hunting, and fishing.

• Developed agriculture or recreation, such  as crop
  land,  water sports,  and  vacation resorts.

• Suburban dwellings or light commercial and industry.

• Urban dwelling or heavy commercial and industry.

Many of these  land uses  are compatible with sewage
sludge application.

9.3  Nutrients, Soil pH, and Climate
      Considerations

9.3.1   Nutrients

During  mining  and regrading operations, the original
surface  layers are  usually  buried so deeply that the soil
nutrients present are  not available to plants in the dis-
                 turbed soil. Nitrogen and phosphorus are often deficient
                 on  disturbed lands, with phosphorus  often being the
                 most limiting fertility factor in plant establishment. Sew-
                 age sludge is generally an excellent source  of these
                 nutrients. The amount of sewage sludge applied at one
                 time during land reclamation can be relatively large  (7
                 to 450 dry t/ha or 3 to 200 T/ac) to ensure that sufficient
                 nutrients, as well as organic matter, are introduced into
                 the soil to support vegetation until a self-sustaining eco-
                 system is established. The local agricultural experiment
                 station or Cooperative  Extension Service can  provide
                 recommendations  for the additional quantities of N,  P,
                 and K required to support vegetation for the site.

                 9.3.1.1   Nitrogen

                 An  advantage of using sewage sludge for land reclama-
                 tion is that it is a slow-release source of organic nitrogen
                 fertilizer that will supply some nitrogen for 3 to 5 years.
                 Depending on the treatment process, much of the origi-
                 nal wastewater nitrogen is in the organic form and there-
                 fore not  immediately available for plant use until it is
                 converted to inorganic nitrogen by mineralization, mak-
                 ing it available to  plants. This process  is discussed  in
                 Chapters 4 and 7.

                 Under the  federal Part 503 regulation, the permitting
                 authority may authorize for reclamation sites a sewage
                 sludge application  rate greater than the agronomic rate
                 for  N. The person who applies the sewage sludge must
                 be able to show that N application in excess of crop and
                 vegetative  requirements would not contaminate ground
                 water or surface water. The permitting  authority may
                 allow a temporary impact on the reclamation site (e.g., may
                 allow one application only, at a higher application rate).

                 The amount of nitrogen needed to establish vegetation
                 on a reclamation site depends on the type of vegetation
                 to be grown and the amount of nitrogen available in the
                 soil. The designer  should have information on:
                                                   112

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• The  amount and  type  of nitrogen in the sewage
  sludge (organic N, ammonium, and nitrate).

• The  plant-available nitrogen content of the existing
  soil,  if available.

• The  fertilizer nitrogen requirements of the vegetation
  planned for the site.

This information is used to determine the sewage sludge
application rate so that sufficient nitrogen is applied for
the vegetation but is not in excessive amounts that could
cause  unacceptable  levels of nitrate  leaching into sur-
rounding ground water, as shown in Section 9-7.

The designer should also  consider the postreclamation
land use when determining the amount of nitrogen needed
to supply the vegetative needs. If the vegetation grown is
to be harvested and removed from the  site, supplemental
nitrogen applications may be needed periodically to  main-
tain adequate productivity. If the reclaimed area is refor-
ested or the vegetation grown  is not harvested, most of the
nitrogen will remain on the site and be recycled through
leaf fall and vegetation decomposition.

Sewage sludge applications on mine land usually increase
the total nitrogen concentration in the foliage of vegetation
(Sopper, 1993). It has been speculated that while exces-
sively high nitrogen concentrations in plants do not harm
the plants themselves, they could cause metabolic disrup-
tions in foraging animals. No published documentation of
this phenomenon exists, however (Sopper, 1993).

Drastically disturbed lands can be divided into two cate-
gories—those requiring topsoil enhancement and  those
without topsoil. On sites  with topsoil, an agricultural
application rate  might  be used, with relatively  small
quantities of sewage sludge  being applied annually (as
discussed in  Chapter 7). On abandoned  sites or sites
without topsoil replacement, however, a much larger
application of sewage sludge may be necessary to es-
tablish  vegetation and improve the physical status  of the
soil. Soil fertility  is also increased by the nitrogen and
phosphorus in sewage sludge as well as the many micro-
nutrients in sewage sludge  necessary for plant growth.

9.3.2   SoilpH andpHAdjustment

Most grasses and legumes, as well  as many shrubs
and deciduous trees, grow  best in the soil pH range
from 5.5 to 7.5, and pH adjustments may be necessary
at reclamation sites.

Several states have adopted regulations stating that where
sewage sludge is applied to land,  the soil pH must be
adjusted to 6.0 or greater during the  first year of initial
sewage sludge application and 6.5 during the second year
(Pennsylvania Department of Environmental Resources,
1988).  In addition,  the soil pH of 6.5  may need  to be
maintained for 2 years after the final sewage sludge appli-
cation.  This is recommended because trace metals are
more  soluble under  acidic conditions than neutral  or
alkaline conditions. If the soil pH is not maintained above
6.0 and is allowed to revert to more acidic levels, some
trace metals in the sludge may become soluble; once in
solution, the metals would be available for plant uptake.

Lime often is used for pH adjustment, but other agents
also are feasible.  Recommendations for pH adjustment
can usually be  obtained by sending soil samples  to a
qualified laboratory orthe agricultural experiment station
soil testing  lab at the nearest land grant  college  or
university.  Common  soil  tests  for lime requirements
often seriously  underestimate the lime requirement for
sulfide-containing disturbed lands. In addition, the appli-
cation of sewage sludge on disturbed lands may cause
further acidification. This must be taken into considera-
tion in calculating lime requirements.

9.3.3  Factors A ffecting Crop Yields at
       Reclamation Sites

Where sewage  sludge is applied at reclamation sites for
agricultural production, crop yields can be variable. Limit-
ing factors can  include climatic  conditions and shallow
rooting depths (Gschwind and Pietz, 1992). Peterson  et al.
(1982)  found that adequate moisture and essential ele-
ments for  crop needs were critical for corn yields grown
immediately  after  land leveling on  sewage  sludge-
amended soil at a strip mine reclamation site. Pietz et al.
(1982) found that important parameters were shallow root-
ing depth,  soluble salts, moisture stress,  and element
interactions in plant tissue, sewage sludge, and  soil.

9.3.4  Special Considerations for Arid Lands

When  sewage  sludge  is land applied to  reclamation
sites in arid climates, the concentration of soluble salts
in  the  sludge should be considered. Accumulation  of
salts can hinder revegetation of native grasses because
of competition from salt-tolerant, early successional plants
(Jacobs et al.,  1993). Other considerations for sewage
sludge application to arid lands are discussed in Chapter 7.

9.4  Vegetation  Selection

9.4.1  General

Many plant species have been successfully established
at reclamation  sites. Each site should be considered
unique, however, and plant species or seed mixtures to
be used should be carefully selected. Local authorities
should be consulted for recommendations of appropri-
ate species and  varieties of plants  as well  as  plant
establishment techniques.  Revegetation  suggestions
for various regions of the United States are presented
in  Tables 9-4 through 9-14. Table 9-15 presents some
successful plant species and species mixtures used in
                                                  113

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   Table 9-4.  Humid Eastern Region Vegetation

   Various grasses, legumes, trees, and shrubs have been evaluated for use on disturbed lands in the humid regions of the United
   States. Grass species that have shown promise for use on low pH soils in the eastern United States include weeping lovegrass,
   bermudagrass varieties, tall fescue, chewings fescue, switchgrass, red top, colonial bentgrass, creeping bentgrass, velvet bentgrass,
   deertongue, big bluestem, little bluestem, and brown sedge bluestem (Bennett et al.,  1978).
   Some of the more agriculturally important grass species adapted to better soil conditions on disturbed sites include bromegrass,
   timothy, orchardgrass, perinnial rye grass,  Italian ryegrass, Kentucky bluegrass, Canadian bluegrass, Reed canarygrass, Dallisgrass,
   bahiagrass, and in special situations, lawn grasses including Zoysia japonica Steud and Zoysia matrella. In addition to the common
   grasses, several of the cereal grains, such as rye, oats, wheat, and barley have been used, but mainly as companion crops (Bennett
   et al., 1978).
   Legume species tested on disturbed sites  in eastern United States include alfalfa, white clovers, crimson clover, birdsfoot trefoil,
   lespedezas, red clover, crownvetch, and hairy vetch. Other species that have been successfully tested include flat pea, kura clover,
   zigzag clover, sweet clover, and yellow sweet clover (Bennett et al., 1978).
   Several grass and legume mixtures have been used successfully in Pennsylvania to revegetate drastically disturbed  lands amended
   with municipal sludges. The primary mixture and seeding rate used for spring and summer seeding is:

   Species                               Amount kg/ha

   Kentucky-31  tall fescue                  22
   Orchardgrass                          22
   Birdsfoot trefoil                         11

   Total                                  55


   Metric conversion factor:
       1 kg/ha = 0.89 Ib/ac.
   For late summer and early fall seeding the following mixture has been used successfully:

   Species                               Amount kg/ha

   Kentucky-31  tall fescue                  11

   Orchardgrass                           5
   Winter rye (1 bu/ac)                     63

   Total                                  79


   Metric conversion factor:
   1 kg/ha = 0.89 Ib/ac.
   This mixture has usually been sufficient to establish a vegetative cover to protect the  site over the winter season. The following
   spring, an additional seed mixture, consisting of orchardgrass (11 kg/ha; 9.8 Ib/ac) and birdsfoot trefoil (11  kg/ha; 9.8 Ib/ac), is
   applied. Other seeding mixtures for spring, summer, and fall seeding are found in Rafaill and Vogel, 1978.
   Several tree and shrub species have been utilized on disturbed land areas in the eastern United States. However, in general, trees
   and shrubs have been planted either after the soil has been stabilized with herbaceous species, like grasses and legumes,  or has
   been  planted with them. On certain drastically disturbed areas, trees may be the only logical choice of vegetation where a future
   monetary return is expected. They do provide long-term cover and protection with little or no additional care and maintenance. The
   same precautions should be exercised in selecting tree species for use on disturbed land sites as in selecting grasses and legumes.
   The soil acidity, plant nutrient requirements, chemical and physical properties of the soil, site topographical influences, and other
   environmental factors should be considered.
   Common tree and shrub species grown successfully on disturbed land sites in the eastern  United States include black locust,
   European black alder, autumn olive, white pine, scotch pine, Virginia pine, short leaf pine, red pine, Norway spruce, European and
sewage sludge  reclamation projects.  Food crop selec-     If the  goal of the reclamation effort is to establish a
tion is discussed in Chapter 7.                                vegetative cover sufficient to prevent erosion, a peren-
                                                                 nial grass and legume mixture is a good crop selection.
Plant species to be used should  be  selected for their     It is important to select species that are not  only corn-
ability to grow under drought conditions and their toler-     patible, but also grow well when sewage sludge is used
ance for either acid or alkaline soil material.  Salt toler-     as the fertilizer. A combined  grass and legume seeding
ance is also desirable.                                         mixture allows the grass  species to germinate quickly
                                                            114

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Table 9-5.  Drier Mid-West and Western Region Vegetation

A large number of plant species have been tested on disturbed lands in the Intermountain Region of the United States (Berry, 1982).
Fewer species have been evaluated for reclamation use in the drier regions of the United States. The objective in many reclamation
plantings in the drier regions is to return the area to climax vegetation. In almost every instance, the soils are not the same as
before the disturbance occurred,  and it would seem in many cases that species lower in the successional stage may be better
adapted and more easily established on these sites. Whether a single species or a mixture is selected depends on several factors,
including the planned future use of the site, the desire to have the planting blend with the surrounding vegetation, and the
adaptability and compatibility of the species selected. The factors limiting the successful establishment of vegetation on disturbed
areas may be different on a site being  reclaimed than on adjacent undisturbed areas, where a plant species may be growing
together in what appears to be a stable community. Even after the species have been selected, the  proportionate amounts of
seeding are not easily determined. The successful  experiences of the past 40 years from seeding range mixtures and planting
critical areas appears to be the best guide to the opportunities for success of either single species or mixtures (Berg, 1978).
Table 9-6.  Western Great Lakes Region

This region includes Wisconsin, eastern Minnesota, and the western upper peninsula of Michigan. The common grasses, generally
used in  mixtures with a legume, are tall fescue, smooth  brome, and timothy. Kentucky bluegrass and orchardgrass are also well
adapted. "Garrison" creeping foxtail and reed canarygrass perform well on wet sites. The most commonly used legumes are
birdsfoot trefoil and crownvetch. Numerous species of woody plants can be used depending on specific site conditions. Siberian
crabapple, several  species of poplars, tatarian and Amur honeysuckles, silky dogwood, redosier dogwood, European black alder,
black cherry, and green ash perform well. Autumn  olive is adapted to the southern portion of this area.
Table 9-7.  Northern and Central Prairies

This is the region known as the Corn Belt. Grasses adapted to the area are Kentucky bluegrass, tall fescue, smooth brome, timothy,
and orchardgrass. Reed canarygrass is adapted to wet areas. Switchgrass, big bluestem, and Indiangrass are well adapted warm
season natives. Birdsfoot trefoil, crownvetch, and alfalfa are commonly used legumes.
Woody species that have been successful include autumnolive, European black alder, poplar species, tatarian honeysuckle, Amur
honeysuckle,  black cherry, eastern red cedar, pines, oaks, black walnut, green ash,  black locust, black haw, and osage-orange.
Table 9-8  Northern Great Plains

This region includes most of the Dakotas and Nebraska west to the foothills of the Rocky Mountains and includes northeastern
Colorado. The native wheatgrass (western, thickspike, bluebunch, streambank, and slender) are used extensively in seeding
mixtures. Western wheatgrass should be included in most mixtures, although for special purposes thickspike or streambank
wheatgrass are more appropriate. Green needlegrass is an  important component of mixtures except in the drier areas. On favorable
sites big  bluestem, little bluestem, and switchgrass provide opportunities for color or for a different season of use. Prairie sandreed is
adapted to sandy soils throughout the region. "Garrison" creeping foxtail and reed canarygrass are adapted to wet sites.
Crested wheatgrass has been used extensively and is long-lived in this climate. Intermediate and  pubescent wheatgrasses are
useful in  establishing pastures. The use of smooth brome and tass fescue is limited to the eastern portions of the Northern Great
Plains where the annual precipitation exceeds 50 cm (19.7 in). Alfalfa and white sweetclover are the only legumes used in most of
the area  for reclamation plantings.
Many native and introduced woody plants are adapted for conservation plantings. Fallowing to  provide additional moisture is required
for establishment of most woody  plants and cultivation must generally be continued for satisfactory performance of all but a few
native shrubs.  These practices may not be compatible with certain reclamation objectives, thereby limiting the  use of woody species
to areas with favorable  moisture situations. Some woody plants useful  in this area, if moisture and management are provided, are
Russian-olive,  green ash, skunkbush sumac, Siberian  crabapple, Manchurian crabapple, silver  buffaloberry, tatarian  honeysuckle,
chokecherry, Siberian peashrub, Rocky Mountain juniper,  and willow  species.
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Table 9-9.  Southern Great Plains

The Southern Great Plains are considered to be the area from southcentral Nebraska and southeastern Colorado to central Texas.
The most common native grasses of value in reclaiming drastically disturbed lands include big bluestem, little bluestem, Indiangrass,
switchgrass, buffalograss, blue grama, sideoats grama, and sand lovegrass.  Introduced bluestems such as yellow bluestem,
Caucasian bluestem, and introduced kleingrass, blue panicgrass, and buffelgrass are important in the southern and central portions
of this plant growth region. Alfalfa and white sweetclover are the most commonly used legumes. Russian-olive is a satisfactory
woody species in the northern portions and along  the foothills of the Rocky Mountains. Junipers, hackberry, and skunkbush sumac
are important native species. Osage-orange  is well adapted to the eastern part of this area. Desirable woody plants  require special
management for use on most drastically disturbed lands.
Table 9-10.  Southern Plains

This area is the Rio Grande Plains of south and southwest Texas. The characteristic grasses on sandy soils are seacoast bluestem,
two-flow trichloris, silver bluestem, big sandbur, and tanglehead. The dominant grasses on clay and clay loams are silver bluestem,
Arizona cottontop, buffalograss, curlymesquite, and grama grasses. Indiangrass, switchgrass, seacoast bluestem, and crinkleawn are
common in the oak savannahs.
Old World bluestems, such as yellow and Caucasian bluestems, are satisfactory only where additional moisture is made available.
Natalgrass and two-flower trichloris have shown promise in reclamation plantings.
Table 9-11.  Southern Plateaus

The area is made up of the 750- to 2,400-m (2,450- to 7,875-ft) altitude plateaus of western Texas, New Mexico, and Arizona. The
area includes a large variety of ecological conditions resulting in many plant associations.  Creosote-tarbush desert shrub, grama
grassland, yucca and juniper savannahs, pinyon pine,  oak, and some ponderosa pine associations occur. Little bluestem, sideoats
grama, green sprangletop, Arizona cottontop, bush muhly, plains bristlegrass, vine-mesquite, blue grama, black grama, and many
other species are common and are useful in reclamation plantings, depending on the site conditions and elevation.
Table 9-12.  Intermountain Desertic Basins

This region occupies the extensive intermountain basins from southern Nevada and Utah, north through Washington, and includes
the basin areas of Wyoming. The natural vegetation ranges from almost pure stands of short grasses to desert shrub. There are
extensive area dominated by big sagebrush or other sagebrush  species.
A wide variety of species of grasses  is available for this area. Among the most commonly used species are the introduced Siberian
wheatgrass, crested wheatgrass, intermediate wheatgrass, pubescent wheatgrass, tall  wheatgrass, and hard fescue. Native grasses
used include bluebunch wheatgrass,  beardless wheatgrass, big  bluegrass, Idaho fescue, and Indian ricegrass. Four-wing  and Nuttall
saltbush have performed well in planting trials. Available woody  species are limited, though junipers, Russian-olive, skunkbush
sumac, and other native and introduced woody plants are adapted to the climate where moisture is adequate.
Table 9-13.  Desert Southwest

This is the desert of southwestern Arizona, southern Nevada, and southern California. Creosotebush may occur in almost pure
stands or with tarbush. Triangle bur-sage, white bur-sage, rubber rabbitbrush, and ocotillo are prominent on some sites. Large
numbers of annual and perennial forbs are present. Saltbushes, winterfat, and spiny hopsage are common. The few grasses present
in the understory are largely big galleta, desert saltgrass, grama grasses, and species of threeawns.
Only minor success has been obtained in establishing vegetation on disturbed lands in the desert southwest.  Irrigation for
establishment may be essential in some areas, and the longevity of stands when irrigation is discontinued is not known. Big galleta
and bush muhly show promise. Native shrubs such as creosotebush, fourwing saltbush, and catclaw have also been established.
Reseeding annuals such as goldfields, California poppy, and Indianwheat have also shown promise.
                                                           116

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   Table 9-14.  California Valleys

   The climate of the central California Valleys is classified as semiarid to arid and warm and the moisture is deficient at all seasons.
   The largest area of grassland lies around the edge of the central valley and is dominated by annual species. The only areas
   remaining in grass in the valley are usually too alkaline for crop production. The grasses remaining in these sites are desert
   salt-grass and  alkali sacaton.
   Recommended for seeding in the area of more than 40 cm (15.8 in) annual precipitation is a  mixture of "Luna" pubescent
   wheatgrass,  "Palestine" orchardgrass, and rose clover. Crimson clover, California poppy, and "Blando" brome can be added.
   Inland in the 30 cm (12 in) precipitation areas, a mixture of "Blando" brome, Wimmera ryegrass, and "Lana" woolypod vetch is
   recommended. In the 15- to 30-cm (6 to 12 in) precipitation zone "Blando" brome (soft chess) and rose clover are generally used.
Table 9-15.  Some Sucessful Plant Species and Species Mixtures Used in Various Sludge Reclamation Projects (Sopper, 1993)
State
CO







IL

IL

IL








IL


IL


IL


MD

OH
Species
Slender wheatgrass3
Intermediate wheatgrass3
Pubescent wheatgrass3
Crested wheatgrass3
Smooth brome3
Meadow brome3
Timothy3
Orchardgrass3
Tall fescue
Weeping lovegrass
K-31 tall fescue
Weeping lovegrass
Common bermudagrass3
Sericea lespedeza3
Kobe lespedeza3
Perennial rye grass3
Potomac orchardgrass13
Sericea lespedezab
Kobe lespedezab
Potomac orchardgrass0
Penngift crownvetchc
Tall fescue
Perennial ryegrass
Western wheatgrass
Reed canarygrass
Tall fescue
Redtop
Alfalfa3
Bromegrass3
Tall fescue3
Tall fescue
Birdsfoot trefoil
Fall, balbo rye
Seeding Rate (kg/ha"1)
5.1
4.8
4.6
3.8
4.6
2.6
1.5
1.4
22
8
22
7.8
11
28
11
22
17
22
11
22
17
25
25
25
34
46
17
22.9
9.5
9.1
40
10
9.6 (bu/ha'1)
State




OK

PA








PA


PA



PA










Species
Spr., K-31 tall fescue3
Korean lespedeza3
Sweet clover3
Orchardgrass3
Switchgrass
Kleingrass
Reed canarygrass
Tall fescue
Orchardgrass
Birdsfoot trefoil
Crownvetch
Deertongue
Switchgrass
Alfalfa
Ladino clover
K-31 tall fescue3
Birdsfoot trefoil3
Rye grass3
Tall fescue3
Orchardgrass3
Birdsfoot trefoil3
Crownvetch3
Blackwell Switchgrass
Niagara big bluestem
Birdsfoot trefoil3
K-31 tall fescue3
Perennial ryegrassb
Lathco flatpeab
Oahe intermediate
Wheat grass
Tall fescuec
Orchardgrass0
Crownvetch0
Seeding Rate (kg/ha"1)
11
3.4
3.5
3.3
154
154
224
224
224
224
224
224
224
224
224
39
8
6
22
22
11
11
17
34
22
45
22
67

34
22
22
17
                                                             117

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Table 9-15.  (continued)
State
PA



VA






VA

Species
K-31 tall fescue3
Orchardgrass3
Birdsfoot trefoil3
Crownvetch3
Tall fescue3
Perennial ryegrass3
Annual ryegrass3
Tall fescueb
Perennial ryeb
Sericea lespedezab
Black locustb
K-31 tall fescue3
Redtop3
Seeding Rate (kg/ha"1)
22
22
11
11
8.4
8.4
8.4
22
22
22
0.8
67
5.6
State Species
Ladino clover3
VA Tall fescue
Weeping lovegrass
Korean lespedeza
VA Ky-31 tall fescue
Wl Canada bluegrass3
Red clover3
Smooth bromeb
Alfalfab
Western wheatgrassc
Alsike clover0
Barleyd
Japanese milletd
(added to above mixtures)d
Seeding Rate (kg/ha'1)
5.6
67.3
22
11.2
80
11
9.7
15.2
11
9.7
11
16.5
8.6
  Species with the same superscript letter represent a seeding mixture.

and provides a complete protective cover during the first
year, while also allowing time for the legume species to
become established and develop into the final vegeta-
tive cover. The grasses will also take up a large amount
of the nitrogen, preventing it from leaching  into the
ground water.  Since legume species can  fix  nitrogen
from the atmosphere, additional sewage sludge nitrogen
additions are often unnecessary.

If a site is to be reforested, it is still generally desirable to
seed it with a mixture of grasses and legumes. The initial
grass  and legume cover helps to  protect the site from
erosion and surface runoff and takes  up  the  nutrients
supplied  by the sewage sludge. Planting slow-growing
tree species is generally not recommended because of
the extreme competition from the fast-growing herba-
ceous vegetation. Fast-growing  hardwoods seem to
survive and grow well because they can usually compete
successfully. Suitable species might be black locust, hybrid
poplar, European alder, Catalpa, and European larch.

9.4.2  Seeding and Mulching

Herbaceous species can be seeded by direct drill or
broadcast, hydroseeding, or aerial seeding. Disturbed
sites,  however, often are too rocky and irregular for drill
seeding.  Broadcast seeding is generally more desirable
because the stand of vegetation produced is more natu-
ral in  appearance, with a more uniform and complete
cover, and is  effective in erosion prevention and site
stabilization. Broadcasting  also  achieves a  planting
depth that is better suited to the variety of different sized
seeds usually found in mixtures of species. Aerial broad-
cast seeding may also be useful  for large tracts. It is
generally not necessary to coverthe seed, since the first
rainfall will normally push  the seed into the loosened
surface spoil and result in adequate coverage.
On sites that have good topsoil, agricultural seeding
rates can be used. On abandoned sites, however, it may
be necessary to apply much larger amounts of seed
(Sopper and Seaker, 1983). Mulching is generally not
necessary except on specific sites.  Mulching involves
applying organic or inorganic materials to the soil sur-
face to protect  the seed,  reduce erosion, modify ex-
tremes  in  surface spoil  temperatures,  and  reduce
evaporation. Mulching is generally advisable on steep
slopes and on black anthracite refuse or fly ash banks
to protect germinating vegetation from high surface tem-
peratures, which may be lethal to most plants. Mulching
may also be required by some state regulatory agencies
for specific situations.  Materials used for mulching are
straw, hay, peanut hulls, corn cobs, bagasse, bark, saw-
dust, leaves, and wood chips.

9.5   Sewage Sludge Application Methods

9.5.1   Transportation
Chapter 14 discusses sewage sludge transport in detail.
A special consideration in transport of sewage sludge to
reclaimed  mined land is the potential to backhaul sew-
age sludge (i.e., use the same trucks, railcars, etc., that
transport the mined ore to the  city for transporting the
sewage sludge  from the city back to the mining area).
For example, in 1981-82, the city of Philadelphia back-
hauled about 54,432 t (60,000 T) of sewage sludge
annually in coal trucks a distance of 450 km (280 mi) to
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help reclaim strip mine sites in western Pennsylvania
(Sopperet al., 1981).

9.5.2  Site Preparation Prior to Sewage
       Sludge Application

Under federal and state mining regulations, disturbed
mine sites generally must be graded after mining to the
approximate original contour of the area. Abandoned
areas where no regrading has been done should also
be regraded to a relatively uniform slope of less than 15
percent prior to sewage sludge application.

9.5.2.1   Scarification

Prior to sewage  sludge  application, the soil surface
should be roughened or loosened to offset compaction
caused during the  leveling or grading operation. This will
help to improve surface water infiltration and permeability
and slow the  movement of any surface  runoff and ero-
sion. A heavy mining disk or  chisel plow is typically
necessary to  roughen the surface.  It is advisable that
this be done parallel to the site contours.

9.5.2.2   Debris Removal

Preparing a site for land reclamation may require the  re-
moval of debris from mining,  construction, or other opera-
tions previously conducted at the site. The extent to which
debris must be removed depends on  the post-reclamation
use. For example,  if agricultural activities are planned, the
top 60 cm (24 in)  should  be free of foreign material of
any significant size (Gschwind  and  Pietz, 1992). If the
site is to be revegetated for erosion control, debris should
be removed from the top 30 cm (12 in) of soil. If an irrigation
hose is used, extensive rock removal will prevent excessive
wear of the hose (Gschwind and Pietz, 1992).

9.5.2.3   Erosion and Surface Runoff Control
         Measures

Surface runoff and soil erosion from the reclamation site
should be controlled. These measures may include ero-
sion control blankets, filter fences, straw  bales, and
mulch. It  may  be  necessary to construct diversion ter-
races and/or  sedimentation ponds.  The local Natural
Resources Conservation Service (formerly the Soil Con-
servation Service) can be contacted for assistance in
designing erosion and surface runoff control plans. In
addition, see Chapter  13 of this manual.

9.5.3  Methods of Application

Methods  for land application of sewage sludge include
surface spreading, incorporation, spray irrigation, and
injection.  These methods are discussed in Chapter 14.
9.5.4  Storage

Sewage sludge storage will  probably be needed at a
reclamation site. The Part 503 regulation defines stor-
age as the placement of sewage sludge on  land  on
which the sewage sludge remains for two years or less.
Storage may occur at the treatment works and/or at the
land application  site. In general, when liquid  sewage
sludge is used, storage is provided at the treatment plant
in digesters, holding tanks, or lagoons. At land  applica-
tion sites where large quantities of liquid sewage sludge
are used, storage lagoons may be built at the site.

If dewatered sewage sludge is used, storage  may  be
more  advantageously located  at the land application
site. Small storage areas may also be desirable at the
treatment plant for times of inclement weather or equip-
ment breakdown.

At currently mined sites, it may be necessary to trans-
port and stockpile dewatered sewage sludge at the site
prior to land application while the area is being backfilled
and topsoiled. This would allow large quantities of sew-
age sludge to be applied in a relatively short period of
time and also  allows more efficient use  of  manpower
and equipment. Some states have specific regulations
concerning sewage sludge stockpiling onsite for short
periods of time. For example, in Pennsylvania, the sew-
age sludge storage area must be diked to prevent sur-
face water from running into or out of the storage area.

9.6   Scheduling

The timing of sewage sludge application depends on the
climate, soil conditions, and growing season. The Part
503 regulation  prohibits bulk sewage sludge application
to flooded, frozen, or snow-covered reclamation sites in
such a way that the sewage sludge enters a  wetland or
other  surface waters (except as  provided in a permit
issued under Section 402 or 404 of the Clean  Water
Act). Sewage sludge should not be applied during peri-
ods of heavy rainfall because this greatly increases the
chances of surface runoff. Sewage sludge also should
not be applied  in periods of prolonged extreme heat or
dry conditions, since considerable  amounts of  nitrogen
will be lost before the vegetation has a chance to estab-
lish itself. If sewage sludge is applied and allowed to dry
on the soil surface, from 20 to 70 percent of the NH4-N
will be volatilized and lost to the atmosphere  as NH3.
The exact amount of NH4-N lost will depend  on soil,
sewage sludge, and climate conditions (U.S. EPA,  1978).

Sewage sludge  applications should be  scheduled to
accommodate the growing season of the selected plant
species. If soil conditions are too wet when  sewage
sludge is applied, the soil structure may be damaged,
bulk density increased, and infiltration decreased due to
heavy vehicle traffic on the wet soil. This may increase
the possibility of soil erosion  and surface runoff. In ad-
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dition, the tractors or trucks may experience difficulty
driving on the wet soil.

If the area to receive sewage sludge is covered under
federal or state mining  regulations, the sewage sludge
application must be scheduled to comply with the revege-
tation regulations. For example, in Pennsylvania, mined
land can be seeded in the spring as soon as the ground is
workable, usually early in March, but seeding must termi-
nate by May 15. The late summer seeding season is from
August 1  until September 15. The designer should check
on requirements for his or her locale.

9.7  Determining Sewage Sludge
      Application Rates at  Reclamation
      Sites

9.7.1  General Information

Historically, land application of sewage sludge at recla-
mation sites generally has involved large applications of
sludge to sufficiently establish vegetation, with rates
sometimes exceeding 200 t/ha and no subsequent ap-
plications. Such high application rates almost invariably
exceed agronomic rates  for plant nitrogen needs, and can
result in temporary leaching of nitrate into ground water.

The Part 503 rule specifies that, in general, application
of sewage sludge should not exceed the agronomic rate
for  N, but that higher rates may be allowed at reclama-
tion sites if approved by the permitting authority. When
determining sewage sludge application rates, it is useful
to draw a general distinction between "reconstructed"
and "abandoned" reclamation sites:

• "Reconstructed"  reclamation sites generally  include
  coal mine reclamation  sites that have  been or are
  being reclaimed according to provisions of the 1977
  federal Surface Mining Reclamation and Control Act
  (SMCRA), and surface-mine reclamation sites involv-
  ing non-coal minerals (such as iron and copper) regu-
  lated by other federal or state programs that  require
  a measure of soil reconstruction after the mineral has
  been removed. SMCRA requires grading of spoils to
  reestablish the approximate original contour of the
  land, the saving and replacement of topsoil  on  all
  areas affected by mining,  and  additional soil recon-
  struction for prime farmlands. Grading of mine spoils
  and replacement of topsoil is also a routine practice at
  active surface mine sites involving non-coal minerals.

• "Abandoned" reclamation  sites are typically  aban-
  doned  coal mine  sites, especially  those  involving
  acid- or toxic-forming spoil or coal refuse, where dis-
  turbance occurred prior to enactment of SMCRA and
  natural revegetation  has been  sparse. Other mine
  sites where mining practices or unfavorable overbur-
  den chemistry have resulted in poor vegetation es-
  tablishment also can be considered "abandoned" rec-
  lamation sites.

Generally, application of sewage sludge at rates exceeding
plant N requirements is not justified at reconstructed rec-
lamation sites,  and procedures for determining sewage
sludge application rates should  be the same as those
described in Chapter 7 for agricultural crops or Chapter
8 for forest sites.  An exception might be where topsoil
was very thin or missing before  mining, such as forest
lands on steep slopes with weakly developed soil hori-
zons (Sopper,  1993).

Large, one-time sewage sludge applications  that ex-
ceed  the agronomic rate for N are most likely to  be
justified at  abandoned sites, such as abandoned acid
strip mine spoils, where ground-water quality is usually
already severely degraded. At such sites, the long-term
benefits of the large addition of organic matter in the
sewage sludge to the mine  spoils for establishing  an
improved vegetative cover exceed the short-term effects
of leaching of excess nitrate from the sludge. Section
9.7.2  below describes a procedure for determining ap-
plication  rates at  abandoned reclamation sites where
the agronomic rate may not be sufficient to reestablish
vegetation.


9.7.2  Approach for Determining a Single,
       Large Application of Sewage Sludge at
       a Reclamation Site

The approach for determining the maximum acceptable
one-time application of sewage sludge to a reclamation
site is based on evaluating the effect of N in excess of
plant  needs from a large application on soil-water  ni-
trate concentrations. The main steps in this procedure
involve:

   1)  Determine the maximum  allowable  application
      rate (Smax)  (e.g.,  based on the Part 503 CPLR
      limits, see Chapter 3).

   2)  Perform  N budget calculations to determine the
      available N  in excess of plant needs (using Smax,
      as described in Section 9.7.3).

   3)  Estimate the soil-water nitrate concentrations that
     will result from the excess N from a  one-time
      application at Smax.

   4)  If soil-water nitrate concentrations from applica-
     tion of Smax are not acceptable,  a lower application
      rate is set that will not exceed a defined accept-
      able soil-water nitrate  concentration.

Section 9.7.3 provides a design example that illustrates
this process.
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9.7.3  Design Example for a Single, Large
       Sewage Sludge Application at a
       Reclamation Site

A five-acre area of abandoned acidic mine spoils (pH
3.9) in Kentucky is to be reclaimed using a single large
application of sewage sludge to provide organic matter
and nutrients required to support establishment of a
mixture of grass and  legumes, with  a first-year N  re-
quirement of 300 kg/ha. Based on appropriate soil tests,
it was determined  that agricultural lime application  of
12.3 t/ha (5.5 T/ac) is sufficient to raise the soil pH  to
6.5. The spoils  are slowly permeable (0.2 cm/hr). Net
precipitation infiltrating into the ground is estimated  to
be 80 cm (31.5  in), of which 20 percent is estimated  to
be lost by evapotranspiration. Depth to ground water is
5 m(16ft).
The sewage sludge to be applied has undergone an-
aerobic digestion and  has the following characteristics:
• Solids  - 4.0 percent
• Organic N - 2.5  percent
• NH4-N -  1.0 percent
• NO3-N - 0 percent
• Total P - 2.0 percent
• Total K - 0.5 percent
• As - 10 mg/kg
• Cd  - 10 mg/kg
• Cr - 1,000 mg/kg
• Cu  - 3,750 mg/kg
• Pb - 150 mg/kg
• Hg  - 2 mg/kg
• Mo  - 8 mg/kg
• Ni - 100 mg/kg
• Se - 15 mg/kg
• Zn - 2,000 mg/kg

   Step 1. Calculate  Maximum Application Based
           on Metal Loading
The cumulative pollutant loading  rate for a particular
metal is calculated using the following equation:
   Smax = L/Cm (1,000 kg/t)

   where:
(9-1)
          = The total amount of sewage sludge, in
            t/ha, that would result in the cumulative
            pollutant loading rate limit, L.
   L      = The Part 503 cumulative pollutant load-
            ing rate limit (CPLR) for sewage sludge
            in kg/ha (see Chapter 3).
   Cm    = Concentration, in mg/kg, of the metal of
            concern in the sewage sludge being
            applied.

The limiting metal in this example is copper, with Smax =
400 t/ha. In reality, most sewage sludges contain lower
copper levels; this higher level is used here to illustrate
an application  rate higher than the agronomic rate.
Since sludge applications at 400 t/ha could result in a
high nitrogen impact on ground water during the first two
years of operation, a loading rate of 200 t/ha was se-
lected, which is sufficient for establishing vegetation.
Note  that if the copper concentration in the sewage
sludge in this example met Part 503's "pollutant concen-
tration limit"  (as do all the other  pollutants listed) rather
than the CPLR limit for copper,  cumulative metal load-
ings would not be required to be tracked (see Chapter
3), and application rates would not be limited by cumu-
lative  pollutant loadings (see Chapter 7, Section 7.4.4.3).

   Step 2. Determine Excess N Available for
          Leaching

Available  N  content of the revised  Smax (200 t/ha)  is
calculated using the following equation:

   Np =  S  [(NOs) + Kv (NH4) + F(year w) (No)] (10)   (9-2)

   where:

   Np     = Plant-available N (from this year's sew-
            age sludge application only), in kg/ha.
   S      = Sewage sludge application rate, in dry t/ha.
   NOs    = Percent nitrate-N in the sewage sludge,
            as percent.
   Kv     = Volatilization factor, usually set at 0.5
            for surface-applied liquid sewage
            sludge, or  1.0 for incorporated liquid
            sludge and dewatered sludge applied in
            any manner.
   NH4    = Percent ammonia-N in the sewage
            sludge, as percent (e.g., 1% = 1.0).
   FiyearO-i)= Mineralization factor for organic N in
            the sewage sludge in the first year, ex-
            pressed as a fraction  (e.g., 0.2).
   No     = Percent organic N  in the sewage
            sludge, as percent (e.g., 2.5% = 2.5).

Since the  sludge is to be surface applied, KV = 0.5.

   NP1 = 200 [(0.0) + (0.5)(1.0)  + (0.2)(2.5)] (10)
       = 2,000 kg/ha

Available N in the second year after the one-time appli-
cation is simply the amount mineralized from the initial
application, using the following equation:
                                                  121

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   Nm = (S) (Km) (N0)

   where:
                                (9-3)
Quantity of N0 mineralized in the year
under consideration, in kg/ha.
Sewage sludge application rate, in dry
t/ha.
Mineralization factor for the year under
consideration, expressed as a fraction.
Percent organic N originally present in
the sewage sludge, as percent (e.g.,
2.5% = 2.5).
   Nm

   S

   Km

   No
In this example, for illustrative purposes, K^ = 0.80 and
Km3 = 0.36 in the second and third years respectively for
anaerobic sludge. Thus:

   Nm2 = (200) (0.80) (2.5)
        = 400 kg/ha

   Nm3 = (200) (0.36) (2.5)
        = 180 kg/ha


A simplified N budget for the Smax sludge application for
the first three years after application  is as follows, with
Nr representing plant uptake (300 kg/ha):

   Year 1 : Nexcess = Npi - Nr = 2,000 -  300 = 1 ,700 kg/ha
   Year 2: Nexcess = Nm2  - Nr = 400 - 300 = 100 kg/ha
   Year 3: Nexcess = Nms - Nr =  100  - 300 = 0 kg/ha


In the  first year, available N  is more than 6 times the
plant uptake, and by the second year is slightly more
than plant uptake. In the third year, mineralized N is less
than potential plant uptake. Consequently, with a one-time
large application of sewage sludge, leaching  of nitrate
can be expected during the  first year,  with  minimal
leaching in the second year and no leaching in the third
year. These  N budget calculations have been simplified
for this illustrative example; the more  detailed  annual  N
budget calculations  contained in  the Worksheets  in
Chapter 7 can also be used.

   Step 3. Calculation of Potential  Nitrate
          Leaching into Ground Water


It is possible to make  a  conservative estimate of the
quantity of nitrates potentially  leaching into the ground
water by calculating the maximum potential concentra-
tion of excess nitrates percolating from the site into the
underlying aquifer. This is done by assuming that all  N
in excess of plant needs is converted to nitrates, and that
no dilution of percolate occurs in existing ground water.
   Assume annual net infiltration of precipitation, PI =
   80 cm.
   Assume evapotranspiration losses, ET = 20% =
   0.20.

If all of the excess  nitrogen in the sludge applied is
mobile (an unlikely and very conservative assumption),
the concentration of nitrate in the percolate is calculated
using the following equation:

Soil Water NO3,  mg/L =
                 kg/ha) (10s mg/kg) (1,000 cm3/L)
               (108 cm2/ha) (P,, cm) (1-ET)

          (1,700 kg/ha) (10s mg/kg) (1,000 cm3/L)
               (108 cnf/ha) (80 cm) (1-0.20)
                                                  = 266 mg/L
                                          Repeating  the calculation for the excess N  in  the
                                          second year indicates a maximum NO3 concentration
                                          of 16 mg/L. By the third year, the site would meet the
                                          nitrate drinking water MCL of 10 mg/L because no ex-
                                          cess N exists.

                                          If the potential  concentration of nitrate-N in the percolate
                                          that exceeds the MCL during the first two years  after
                                          sewage sludge application is unacceptable to the regu-
                                          latory agency,  even though by the third year leaching
                                          effects are  minimal,  and  if there  is no extraction of
                                          potable water  from the aquifer, maximum sludge appli-
                                          cation  rates can be  calculated based on  a maximum
                                          acceptable level of NO3 in percolating soil water.

                                          Additional information on the design of mine land recla-
                                          mation projects using municipal sewage sludge can be
                                          found in the Manual for the Revegetation of Mine Lands
                                          in Eastern  United  States Using Municipal Biosolids
                                          (Sopper,  1994).

                                          9.8    References

                                          When  an NTIS  number  is cited in a  reference, that
                                          document is available from:
                                             National Technical  Information Service
                                             5285 Port Royal Road
                                             Springfield,  VA 22161
                                             703-487-4650
                                          Bennett, O.L., E.L. Mathias, W.H. Arminger, and J.N. Jones, Jr. 1978.
                                             Plant materials and their requirements  for growth in humid re-
                                             gions. In: Schaller, F.W., and P. Sutton, eds. Reclamation of dras-
                                             tically disturbed lands. American  Society of Agronomy, Madison,
                                             Wl. pp.  285-306.
                                                   122

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Berg, W.A. 1978. Limitations in the use  of soil tests on drastically
   disturbed lands. In: Schaller,  F.W., and P. Sutton, eds. Reclamation
   of drastically disturbed lands.  American Society of Agronomy,
   Madison, Wl. pp. 653-664.

Berry, C.R. 1982. Sewage sludge aids reclamation of disturbed forest
   land in the southeast. In: Sopper,  W.E., E.M. Seaker, and R.K.
   Bastian, eds. Land reclamation  and  biomass production with mu-
   nicipal  wastewater and  sludge. Pennsylvania  State University
   Press,  University Park, PA. pp.  307-316.

Fed. Reg. 1982.  Surface coal  mining and reclamation permanent
   program regulations: revegetation. March 23.

Gschwind, J., and R. Pietz. 1992. Application  of municipal sewage
   sludge  to soil reclamation sites. In:  Lue-Hing, C., D. Zenz, and R.
   Kuchenrither, eds. Municipal sludge  management:  Processing,
   utilization, and disposal. Water  Quality Management Library, Vol.
   4. Lancaster, PA: Technomic Publishing Company, pp. 455-478.

Jacobs, L., S. Carr, S. Bohm, S., and J.  Stukenberg. 1993. Document
   long-term experience of biosolids land application programs. Pro-
   ject 91-ISP-4, Water Environment Research Foundation, Alexan-
   dria, VA.

Pennsylvania Department of Environmental Resources. 1988. Land
   application of sewage sludge. In: Rules in the Pennsylvania Code,
   Title 25, Chapter 275.

Peterson, J., C. Lue-Hing, J. Gschwind, R. Pietz, and D. Zenz. 1982.
   Metropolitan Chicago's Fulton County sludge utilization program.
   In: Sopper, W, E. Seaker, and R. Bastian, eds. Land reclamation
   and biomass product with municipal wastewater and sludge.  Uni-
   versity  Park,  PA:  Pennsylvania State  University  Press.  Cited  in
   Gschwind and Pietz, 1992.

Pietz, R.,  J. Peterson,  T. Hinesly, E. Ziegler,  K.  Redborg,  and C.
   Lue-Hing. 1982. Sewage sludge application to calcareous strip-
   mine spoil: I, Effect on corn  yields and N, P, Ca, and Mg compo-
   sitions. J. Environ. Quality  18:685-689.  Cited  in Gschwind  and
   Pietz, 1992.
Rafaill, B.L., and WG. Vogel.  1978. A guide for vegetating surface-
   mined lands for wildlife in  eastern Kentucky and  West Virginia.
   FWS/OBS-78-84. U.S. Fish and Wildlife Service, Washington, DC.

Sopper, W. 1994. Manual for the revegetation of mine lands in the
   eastern United States using municipal biosolids. Morgantown, WV:
   West Virginia  University, National Mine Land Reclamation Center.

Sopper, W. 1993. Municipal sludge use  in land reclamation.  Boca
   Raton, FL: Lewis Publishers.

Sopper, W, and S. Kerr. 1982. Mine land reclamation  with municipal
   sludge—Pennsylvania demonstration program. In:  Sopper, W.E.,
   E.M.  Seaker,  and  R.K. Bastian,  eds. Land  reclamation  and
   biomass product with municipal wastewater and sludge. University
   Park, PA: Pennsylvania  State University Press, pp. 55-74.

Sopper, W, S. Kerr, E. Seaker, W. Pounds, and D. Murray. 1981. The
   Pennsylvania  program for using municipal sludge for mine land
   reclamation. In: Proceedings of the Symposium on Surface Mining
   Hydrology, Sedimentology,  and Reclamation. University  of Ken-
   tucky, Lexington, KY. pp. 283-290.

Sopper, W., and  E. Seaker. 1983. A guide for revegetation of mined
   land in the eastern United States using municipal sludge. Univer-
   sity Park, PA:  Pennsylvania State University Institute for Research
   on Land and Water  Resources.

U.S. Department  of Interior.  1979.  Permanent regulatory program
   implementing  Section 501 (b) of the Surface Mining Control and
   Reclamation Act of 1977; Final Environmental Statement. OSM-
   EIS1. Washington, DC.

U.S. EPA. 1978. Sludge treatment and disposal, Vol. 2. Center for
   Environmental Research Information, Cincinnati, OH.  EPA/625/4-
   78/012 (NTIS PB-299593).

U.S. Soil Conservation Service. 1977. The status of land disturbed by
   surface mining in the United States. SCS-TP-158. Washington, DC.
                                                             123

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                                            Chapter 10
         Land Application at Public Contact Sites, Lawns, and Home Gardens
10.1  General

In addition to land application at agricultural, forest, and
reclamation sites, sewage sludge and domestic septage
can be land applied to lawns and home gardens as well
as "public contact sites." The Part 503 regulation defines
public contact sites as land with a high potential for
contact by the public, such as  parks, ball fields,  ceme-
teries, plant nurseries, turf farms, and golf courses. In
many cases, sewage sludge is  applied to these types of
sites from bags or other containers1 that are sold  or
given away (hereafter referred to as "bagged" sewage
sludge), although sewage sludge also can be land ap-
plied to these types of sites  in bulk form. Often the
sewage sludge used at these sites is  processed and
marketed by municipalities  or private firms as a  brand-
name fertilizer and/or soil conditioning product. Design-
ing  land  application programs geared  toward  public
contact sites, lawns, and home gardens may be particu-
larly useful for municipalities with limited land available
(e.g., highly populated areas with few agricultural, for-
est, or reclamation sites available for sewage sludge
application).

This chapter discusses  how the Part 503 requirements
pertain to land application of sewage sludge and domes-
tic septage at public contact  sites, lawns,  and home
gardens (Section 10.2). Important factors to consider in
designing a marketing program for sewage sludge to be
land applied at public contact  sites, lawns, and home
gardens are discussed in Section 10.3.

10.2 Part 503 Requirements

Many of the strictest requirements in  Part 503 must be
met for sewage sludge or domestic septage that  is land
applied to public contact sites, lawns,  and  home gar-
dens (e.g., Class A pathogen reduction; for metals, an-
nual pollutant  loading  rate  limits for bagged sewage
sludge or pollutant concentration limits for bulk sewage
sludge, see Chapter 3). Domestic septage applied  to
public contact sites, lawns, or home gardens must meet
the same requirements as bulk sewage sludge that is
land applied,  although less burdensome requirements
pertain to domestic septage applied to other types of
land (agricultural,  forest, or reclamation sites), as de-
scribed in Chapter 11. The stringent requirements are
specified for sewage sludge that is land applied to public
contact sites,  lawns, and home gardens because of the
high potential for human contact with sewage sludge at
these types of sites and because it is not feasible to
impose site restrictions when sewage sludge is sold or
given away in bags or other containers for application to
the land. The  sewage sludge used in this manner must
meet the requirements for metals, pathogens, vector
attraction reduction, management practices, and  other
requirements  specified in  Part 503  for application  to
these types of sites, as discussed in Chapter 3.

The effects of the Part 503 regulation on current sewage
sludge land application programs depends  on the qual-
ity of the sewage  sludge. If a sewage sludge meets
certain Part 503 requirements, the sewage sludge can
be considered "exceptional quality" (EQ), as discussed
in  Chapter  3. EQ  sewage sludge can be applied as
freely as any other fertilizer or soil amendment to any
type of land. If EQ sewage sludge requirements are met,
current land  application operations, including  those
with already successful marketing programs for sew-
age sludge (see Section 10.3), may continue with a
minimum of additional regulatory requirements. Forsew-
age sludge preparers2 who have difficulty meeting the Part
503 requirements for public contact sites, lawns, or home
gardens, operational  changes may need to be imple-
mented to further  reduce pathogen or metal levels for
land application at these types of sites. The types of
sewage sludge treatment and  preparation that can
achieve EQ-quality sewage sludge (e.g.,  heat drying)
are discussed in Chapter 3.

10.3 Marketing of Sewage Sludge

After processing to achieve Part 503 requirements, sew-
age sludge that is to be  land applied at public contact
1 The Part 503 regulation defines "other containers" as open or closed
 receptacles, such as buckets, boxes, carton, or vehicles, with a load
 capacity of 1 metric ton or less.
"The Part 503 regulation defines a person who prepares sewage
 sludge as either the person who generates sewage sludge during
 the treatment of domestic sewage in a treatment works or the person
 who derives a material from sewage sludge.
                                                 125

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sites, lawns, and  home gardens often is marketed to
distributors or end users (e.g., landscapers, home gar-
deners), frequently as bagged sewage sludge. Designing
a marketing program for sewage sludge has some simi-
larities to marketing any commercial product, including:

• Maintaining the  "high quality" of the product

• Ensuring the product is readily available

• Developing and maintaining product demand

• Offering competitive pricing

Two marketing factors particularly  relevant to sewage
sludge are:

• Maintaining good public relations

• Ensuring that the operations are acceptable  to the
  community

Having a diversified range of products may be useful. In
the case of sewage sludge, this might include producing
a Class B bulk sewage sludge for agricultural,  forest,
and  reclamation sites, and a Class A bagged sewage
sludge product, such as compost, for use by landscapers,
public works departments, and the public.

10.3.1   De veloping Product Demand

To create and maintain product demand, many munici-
palities or private  firms use a trade name to enhance
marketability, such as Milorganite, a heat-dried, bagged
sewage sludge produced by the city of Milwaukee, Wis-
consin, and  Philorganic, a composted sewage sludge
produced  by the  city of Philadelphia,  Pennsylvania.
Other cities that produce heat-dried sewage  sludge in-
clude Chicago, Houston, Atlanta, Tampa Bay, and New
York City. Municipalities that  produce composted sew-
age  sludge  include the District of Columbia,  Kittery
(Maine), Denver, Missoula (Montana), and Los Angeles.

Some municipalities  also conduct market surveys to
determine who would be interested in purchasing their
product; use agricultural professionals as sales agents;
advertise in professional journals and the mass media;
and contract with an intermediary for distribution.

The wastewater treatment plant or other preparer of
sewage sludge may be able to increase marketability by
offering the customer various  important "services," such
as (Warburton, 1992):

• Storing the user's purchased sewage sludge  at the
  wastewater treatment plant (in accordance with Part
  503 provisions).

• Providing the user with results of nutrient, pollutant,
  and any ground-water, surface water, or plant tissue
  sampling tests.

• Offering dependable transport to the land application
  site at times suitable for land application.
• Assisting in obtaining required permits.

• Performing reliable inventory management,  so that
  the "product" is always available when needed.

In many cases, marketing of sewage sludge can include
promoting the concept of reuse/recycling. For exam-
ple, the City of Los Angeles now reuses 100%  of its
300 dT/day of sludge through agricultural land applica-
tion (at various sites), as soil cover at a landfill, and
composting. Los Angeles has implemented several in-
novative sewage sludge marketing programs. One is the
"Full Cycle Recycle" composting  program, which in-
cludes public education for LA's "Topgro" soil  amend-
ment/compost product. Topgro is  produced  from city
wastes  (sewage sludge and/or yard trimmings),  proc-
essed locally, and marketed as "home grown"  to local
nurseries, retailers, and City agencies in bulk or bag at
competitive prices. Another LA sewage sludge market-
ing  program is a cooperative  composting project be-
tween  the city's Department  of Public Works  and
Department of Recreation and Parks,  in which sewage
sludge,  zoo manure, and plant wastes are  processed
and  used as compost  at city parks; the composting
facility also  serves  as  an  educational  center for the
public (Molyneux et al., 1992).

10.3.2   Marketing Cost Considerations

The costs of a sewage sludge  marketing program may
be high relative to costs of direct land application. Major
cost factors include:

• Dewatering the sewage sludge.

• Composting,  heat drying, or  other processes to
  achieve adequate pathogen reduction and vector
  attraction reduction.

• Market development.

• Transportation.

Dewatering and other processing can involve significant
capital  expenditures.  Some  generators/preparers of
sewage sludge may choose to contract out some proc-
essing technologies, which can be done through com-
petitive  bidding  between vendors that produce similar
products (e.g., a heat-dried product,  compost, certain
alkaline stabilization processes that meet  Part 503
Class A pathogen  reduction  requirements) to reduce
program costs (Warburton, 1992). The City of Los An-
geles has reduced its sludge management program
costs by an average of $3 per dry ton as a result
of improved management, decreased transportation
times, price rebates, volume discounts, and minimizing
truck loading times (Molyneux et al., 1992).

A marketing program for sewage sludge always should
include examination of the costs of transporting the sew-
age sludge. Transportation costs may include conveying
                                                 126

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the sludge from the wastewater treatment plant to the
processing  center, transport of bulking  materials  for
composting,  and  distribution of the finished  sewage
sludge product. Although  extending the geographical
marketing area would increase shipping costs, it may be
worthwhile if it is likely that potential buyers in the ex-
tended area are willing to pay a higher price for the
product.

Some municipalities charge the distributor or end user
for the use of a sewage sludge product, as shown  in
Table 10-1. The table indicates that from 38% to 60% of
POTWs sell their sludge at rates ranging from $4 to $6 per
cubic yard or $34 to $63  per ton. In some cases, the
municipality may not make  a "profit" from selling sewage
sludge,  but the sales can reduce operating  costs  for
overall sewage sludge management. In other cases, the
sewage sludge generator or preparer pays the land-
owner or person responsible for land applying sewage
sludge if payment results in lower sewage sludge man-
agement costs.

In some localities, demand  has exceeded supply  for
marketed sewage sludge. In other areas, marketed sew-
age  sludge programs have failed because of  poor  or
inconsistent product quality or operational practices un-
acceptable  to the community. Demand  for  sewage
sludge for land application tends to be seasonal, peak-
ing in the spring  and fall in areas with four-season
climates. In areas  with mild climates year-round, a con-
stant market can be developed.
Table 10-1.  Percent of POTWs Selling Sewage Sludge and
           Mean Price of Sewage Sludge Sold (Adapted
           From U.S. EPA, 1990)
Reported Flow
Rate Group3
1
2
3
4
% of POTWs
That Sellb
60.0%
71.4
42.1
37.5
Price Per
Ton0
$63
34
-
-
Price Per
Cubic Ydc
$5
6
4
6
3 Flow rate group 1=>100MGD;2 = >10-100MGD;3 = >1-10MGD;
 4 = 0-1 MGD.
b Percents based on a total of 46 POTWs.
c 50% of the POTWs who reported that they sold  sewage sludge
 provided  price data.

10.4  References
Molyneux, S., R. Fabrikant, and C. Peot. 1992. Waste to resource:
   The dynamics of a sludge management program. In: Proceedings
   of the future direction of municipal sludge (biosolids) manage-
   ment: Where we are and where we're going, Vol. I, Portland, OR.
   Water Environment Federation, Alexandria, VA.

U.S. EPA. 1990. National sewage sludge survey: Availability of infor-
   mation and data, and anticipated impacts on proposed regula-
   tions. Fed. Reg. 58:18.

Warburton, J. 1992. So, you're convinced sludge is a valuable re-
   source—Then market it like a perishable commodity. In: Proceed-
   ings  of the future direction of municipal sludge (biosolids)
   management: where we are and where we're going, Vol. 1, Port-
   land, OR. Water Environment Federation, Alexandria, VA.
                                                    127

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                                            Chapter 11
                           Land Application of Domestic Septage
11.1  General
Land application of domestic septage is an economical
and environmentally sound practice used by many rural
communities. Like land application programs for other
types of sewage sludge, a properly managed land ap-
plication program for domestic septage can benefit from
the reuse of the organic matter  and nutrients in the
domestic septage without adversely affecting public
health. Sometimes, however,  finding  suitable  sites,
overcoming local opposition, or meeting regulatory re-
quirements may be difficult. The Part 503 regulation
governing the use or disposal of sewage sludge, prom-
ulgated in February 1993, includes simplified require-
ments for the land application  of domestic septage
(compared to more extensive requirements  for other
types of  sewage sludge  generated  by  a wastewater
treatment plant). While the Part 503 rule provides  mini-
mum guidelines for state programs, individual state
regulations may be more stringent.
The Part 503 regulation includes minimum requirements
for the application of domestic septage to land  used
infrequently by the general public, such as agricultural
fields, forest  land, and reclamation sites.
For land application of domestic septage to land where
public exposure potential  is high, however (i.e., public
contact sites  or home lawns  and gardens), the same
Part 503  requirements as those for bulk sewage sludge
applied to the land must be met (i.e., general require-
ments, pollutant limits, pathogen  and vector attraction
reduction  requirements, management practices,  fre-
quency of monitoring requirements, and recordkeeping
and reporting requirements) (U.S. EPA,  1994a). See
Chapter 3 for a  discussion of each of these provisions
of the Part 503 rule.
The remainder of this chapter  focuses on the land ap-
plication  of domestic septage  to agricultural land, for-
ests, or reclamation sites. For additional information on
applications to these types of land, see Domestic Sep-
tage Regulatory Guidance: A Guide To Part 503 (U.S.
EPA, 1993).
11.1.1  Definition of Domestic Septage
Domestic septage is defined in the Part 503 regulation
as the liquid or solid material removed  from a  septic
tank, cesspool, portable toilet, Type III marine sanitation
device, or a similar system that receives only domestic
sewage (water and wastewater from humans  or house-
hold operations that is discharged to or otherwise enters
a treatment works).  Domestic sewage generally  in-
cludes wastes derived from the toilet, bath and shower,
sink, garbage disposal, dishwasher, and washing ma-
chine. Domestic septage may include household sep-
tage as well as septage  from establishments such  as
schools, restaurants,  and motels, as long as this sep-
tage does not contain other types of wastes than those
listed above.
Domestic septage characteristics are presented in Ta-
ble  11-1 (conventional wastewater parameters and nu-
trients)  and  Table  11-2  (metals and  organics) (U.S.
EPA, 1994a).
Table 11-1.  Characteristics of Domestic Septage:
          Conventional Parameters (U.S. EPA, 1994b)
Parameter
     Concentration (mg/L)

Average  Minimum   Maximum
Total solids
Total volatile solids
Total suspended solids
Volatile suspended solids
Biochemical oxygen demand
Chemical oxygen demand
Total Kjeldahl nitrogen
Ammonia nitrogen
Total phosphorus
Alkalinity
Grease
PH
34,106
23,100
12,862
9,027
6,480
31,900
588
97
210
970
5,600
—
1,132
353
310
95
440
1,500
66
3
20
522
208
1.5
130,475
71 ,402
93,378
51 ,500
78,600
703,000
1,060
116
760
4,190
23,368
12.6
                                                 129

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Table 11-2.  Characteristics of Domestic Septage: Metals and
          Organics (U.S. EPA, 1994b)

                         Concentration (mg/L)
Parameter
Average
Minimum
Maximum
Metals
Iron
Zinc
Manganese
Barium
Copper
Lead
Nickel
Chromium (total)
Cyanide
Cobalt
Arsenic
Silver
Cadmium
Tin
Mercury
39.3
9.97
6.09
5.76
4.84
1.21
0.526
0.49
0.469
0.406
0.141
0.099
0.097
0.076
0.005
0.2
< 0.001
0.55
0.002
0.01
< 0.025
0.01
0.01
0.001
< 0.003
0
< 0.003
0.005
< 0.015
0.0001
2740
444
17.1
202
261
118
37
34
1.53
3.45
3.5
5
8.1
1
0.742
Organics
Methyl alcohol
Isopropyl alcohol
Acetone
Methyl ethyl ketone
Toluene
Methylene chloride
Ethylbenzene
Benzene
Xylene
15.8
14.1
10.6
3.65
0.17
0.101
0.067
0.062
0.051
1
1
0
1
.005
0.005
0.005
0.005
0.005
396
391
210
240
1.95
2.2
1.7
3.1
0.72
11.1.2  Domestic Septage Versus
        Industrial/Commercial Septage

The specific definition of domestic septage in the Part 503
regulation does not include many materials that are  often
called septage by industry. Commercial and industrial sep-
tage  are not considered domestic septage. The factor that
differentiates commercial and industrial septage from domes-
tic septage is the type of waste being produced (a treatment
works, e.g., a septic tank, receiving domestic sewage), rather
than  the type of establishment generating the waste. For
example, sanitation waste and residues from food and nor-
mal dish cleaning from a restaurant are considered domestic
sewage, whereas grease trap wastes from a restaurant are
classified as commercial septage. If restaurant grease trap
wastes are included with domestic septage in a truckload,
then the whole truckload is not covered by the Part 503
regulation (U.S. EPA,  1993). Instead, commercial and
industrial septage and mixtures of these septages with
domestic septage are regulated under 40 CFR Part 257
if the septage is used ordisposed on land. Industrial and
commercial  septage  containing  toxic compounds  or
heavy metals require special handling, treatment, and
disposal  methods; a  discussion  of these methods is
beyond the scope of this manual.

11.2 Regulatory  Requirements for Land
      Application of Domestic Septage

11.2.1  Determining Annual Application Rates
        for Domestic Septage at Agricultural
        Land, Forests, or Reclamation Sites

Federal requirements that have been established under
Part 503 for land application of domestic septage  are
discussed in Chapter 3. According to the Part 503 regu-
lation, the maximum volume of domestic septage that
may be applied  to agricultural land,  forest land, or a
reclamation site during a 365-day period depends on the
amount of nitrogen required by the crop for the planned
crop yield. The maximum volume for domestic septage
is calculated by the following formula:
                                                                       AAR:
                                                                                N
                                                                              0.0026
                                                        Where:

                                                        AAR   =

                                                        N
            Annual application rate in gallons per
            acre per 365 day period.
            Amount of nitrogen in pounds per acre
            per 365 day period needed by the crop
            or vegetation grown on the land.
                                                     For example, if  100 pounds  of nitrogen  per acre  is
                                                     required to grow a 100 bushel per acre crop of corn, then
                                                     the AAR of domestic septage is 38,500 gallons per acre
                                                     (U.S. EPA, 1993):
AAR =
                        = 38,500 gal Ion ^ere/year
Application rate requirements pertain to each site where
domestic septage is applied and must be adjusted to the
nitrogen requirement for the crop being grown (U.S. EPA,
1 993). Nitrogen requirements of a crop depend on expected
yield, soil conditions, and other factors such as temperature,
rainfall, and length of growing seasons. Local agricultural
extension agents should  be contacted to determine the
appropriate  nitrogen requirements  for use in the above
equation for calculation of the application rate.

Table 11-3 outlines typical nitrogen requirements of vari-
ous crops and corresponding domestic septage applica-
tion rates (U.S. EPA, 1993). These values are listed as
general guidance only;  more specific information on the
                                                 130

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Table 11-3.  Typical Crop Nitrogen Requirements and
          Corresponding Domestic Septage Application
          Rates (U.S. EPA, 1993)

Corn
Oats
Barley
Grass & Hay
Sorghum
Peanuts
Wheat
Wheat
Soybeans
Cotton
Cotton
Expected
Yield
(bushel/acre/
year)
100
90
70
4 tons/acre
60
40
70
150
40
1 bale/acre
1 .5 bales/acre
Nitrogen
Requirement
(Ib N/acre/
year)1
100
60
60
200
60
30
105
250
30
50
90
Annual
Application
Rate
(gallons/acre/
year)
38,500
23,000
23,000
77,000
23,000
11,500
40,400
96,100
11,500
19,200
35,000
1 These figures are very general and are provided for illustration
 purposes. They should not be used to determine your actual appli-
 cation rate. Crop fertilization requirements vary greatly with soil type.
 Expected yields and climatic conditions are also important factors
 in determining the appropriate volume of domestic septage to apply
 to a particular field. Different amounts of nutrients can be required
 by the same crop grown in different parts of the country. To get more
 specific information on crop fertilization needs specific to your loca-
 tion, contact local agricultural extension agents.

amount of nitrogen required for the  expected  crop yield
under local soil  and climatic conditions should be ob-
tained from a qualified, knowledgeable person, such as
a local agricultural extension agent. The  crop nitrogen
requirement is then used in the annual application rate
formula to calculate the  gallons per acre of domestic sep-
tage that can be applied.

While not required by the Part 503  rule, it is  important
that the septic tank pumper inform the  landowner or
lease holder of the  land application  site regarding how
much of the crop's nitrogen requirement was  added by
the applied domestic septage. This information will allow
the land owner to determine how much additional nitro-
gen, if any, in the form  of chemical fertilizer will need to
be applied (U.S. EPA,  1993). The pumper should also
inform the landowner/leaser of any site restrictions.

11.2.1.1   Protection of Ground Water from
          Nitrogen Contamination

The primary reason  for  requiring the annual rate calcula-
tion is to prevent the over-application of nitrogen in excess
of crop needs and  the potential movement of nitrogen
through soil to ground water. The annual application rate
formula was  derived using  assumptions that facilitate
land application of domestic septage. For example, frac-
tional availability of nitrogen from land-applied domestic
septage was assumed over a 3-year period to obtain the
0.0026 factor in the application formula. Also, in deriving
the formula, domestic septage was assumed to contain
313 mg/l per year available  nitrogen (in year three and
thereafter) (U.S. EPA, 1992a).

Domestic septage from portable chemical toilet and type
III marine sanitation  device  wastes can contain 4 to 6
times more total nitrogen than was assumed to derive
the annual application rate formula, however (U.S.  EPA,
1993). While  not required  by the Part  503 regulation, it
is recommended  that land appliers consider reducing
the volume applied per acre of such high nitrogen-con-
taining domestic septage (U.S. EPA, 1993). For exam-
ple, if the land owner is expecting to grow a 100-bushel
per acre corn crop and the domestic septage contains
6 times more total nitrogen, the gallons applied should
be reduced 6-fold (from 38,500 to about 6,400 gallons).

For additional guidance on avoiding nitrogen contamina-
tion of ground water when land applying  domestic septage
with a high nitrogen content or dewatered domestic sep-
tage,  see Domestic  Septage  Regulatory  Guidance: A
Guide to the EPA 503 Rule (U.S. EPA, 1993).

11.2.2   Pathogen Reduction Requirements

Domestic septage must be managed so that pathogens
(disease-causing organisms) are appropriately reduced.
The Part 503 regulation offers two  alternatives to  meet
this requirement.  Pathogen  reduction  alternative  1 (no
treatment) and restrictions are presented in Figure 11-1
(U.S.  EPA, 1993); the requirements of pathogen reduc-
tion alternative 2 (with treatment)  are listed  in Figure
11-2 (U.S. EPA, 1993). Both of the pathogen reduction
alternatives impose  crop  harvesting  restrictions. Site
access controls and  grazing restrictions, however, are
also required when the domestic septage is not treated
(alternative 1  only). Certification that the Part 503 patho-
gen reduction requirement has been met is also required
of the domestic septage land applier,  as discussed  in
Section 11.2.4 below. Chapter 3 discusses the pathogen
reduction requirements of Part 503 in greater detail.

11.2.3   Vector Attraction Reduction
         Requirements

For application of domestic septage to  agricultural  land,
forests, or reclamation sites, the  Part 503 regulation  re-
quires that one of the following three options be imple-
mented to reduce  vector attraction (U.S. EPA, 1994b):

• Subsurface injection.

• Incorporation (surface application followed by plow-
  ing  within 6 hrs).

• Alkali stabilization.
                                                   131

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   Domestic septage is land applied without treatment, and the
   following restrictions must be observed:

   Crop Restrictions:
   • Food crops with harvested parts that touch the domestic
    septage/soil mixture and are totally above ground shall not
    be harvested for 14 months after application of domestic
    septage.
   • Food crops with harvested parts below the surface of the
    land shall not be harvested for either (1) 20 months after
    application if domestic septage remains on the land
    surface for 4 months or longer, or (2) 38 months after
    application if domestic septage remains on the land
    surface for less than 4 months, prior to incorporation into
    the soil.
   • Feed, fiber, and food crops shall not be harvested for 30
    days after application of the domestic septage.
   • Turf grown on land where domestic septage is applied
    shall not be  harvested for one year after application of the
    domestic septage when the harvested turf is placed on
    either a lawn or land with a high potential for public
    exposure, unless otherwise specified by the permitting
    authority.

   Grazing Restrictions:
   • Animals shall not be allowed to graze on the land for 30
    days after application of domestic septage.

   Site Restrictions:
   • Public access to land with a low potential for public
    exposure shall be restricted for 30 days after application of
    domestic septage.  Examples of restricted access include
    remoteness of site, posting with no trespassing signs,
    and/or simple fencing.
Figure 11-1.   Part 503 pathogen reduction Alternative 1 for do-
             mestic septage (without additional treatment) ap-
             plied to agricultural land, forests, or reclamation
             sites (U.S. EPA, 1993).

For  detailed  information on subsurface injection and
incorporation practices  at land application sites,  see
Chapter 14.

Alkali stabilization of domestic septage involves raising
its pH. Vector attraction is reduced if the pH is raised to
at least 12 through alkali addition and maintained at 12
or higher for 30 minutes without adding more alkali.
When  this option is used, every container of domestic
septage must be monitored to demonstrate that it meets
the requirement (U.S.  EPA, 1992b). When this is done,
the treatment component of alternative  1 for pathogen
reduction,  discussed above, also is met.  This vector
attraction reduction requirement is slightly less stringent
than the alkali addition method  required  by Part 503 for
othertypes of sewage sludge. This option addresses the
practicalities of using  or disposing domestic septage,
which is typically treated  by lime addition  to the domestic
septage hauling truck (see Section  11.3). The treated
septage is typically applied to the land shortly after lime
   The pH of the domestic septage is raised to 12 or higher by
   the addition of alkali material and, without adding more
   alkali, the pH remains at 12 or higher for 30 minutes prior to
   being land applied. In addition, the following restrictions
   must be observed.

   Crop Restrictions:
   • Food crops with harvested parts that touch the domestic
    septage/soil mixture and are totally above ground shall not
    be harvested for 14 months after application of domestic
    septage.
   • Food crops with harvested parts below the surface of the
    land shall not be harvested for either (1) 20 months after
    application if domestic septage remains on the land
    surface for 4 months or longer, or (2) 38 months after
    application if domestic septage remains on the land
    surface for less than 4 months, prior to incorporation into
    the soil.
   • Feed, fiber, and food crops shall not be harvested for 30
    days after application of the domestic septage.

   Grazing Restrictions:      None

   Site Restrictions:         None
Figure 11-2.   Part 503 pathogen reduction Alternative 2 for do-
             mestic septage (with pH treatment) applied to ag-
             ricultural land, forests, or reclamation sites (U.S.
             EPA 1993).

addition.  During this very short time interval, the pH  is
unlikely to fall to a level at which vector attraction could
occur (U.S. EPA, 1992b).

If a land applier of domestic septage chooses pathogen
reduction alternative 1 (see Figure 11-1), which involves
land application of domestic septage without additional
treatment, the Part 503 rule also  requires that one of the
first two vector attraction reduction options listed in Table
11-3 be met (U.S.  EPA, 1993). If a land applier chooses
pathogen  reduction  alternative 2 (pH treatment as de-
scribed in Figure 11-2), he or she must meet the require-
ments of  the  third  vector attraction  reduction option
shown in Figure 11-3 (U.S. EPA,  1993).

11.2.4   Certification Requirements for
         Pathogen and Vector Attraction
         Reduction

The land applier of domestic septage must sign a certi-
fication that the pathogen  and vector attraction reduction
requirements of the Part 503 regulation have been met.
The required  certification is shown in Figure 11-4. The
certification includes a statement by the land applier that
his or her employees, if any, are qualified and capable
of gathering the needed information and performing the
necessary tasks so that the required pathogen and vec-
tor attraction reduction requirements are met. A person
is  qualified if he or she has been sufficiently trained to
do their job correctly.
                                                       132

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   Vector Attraction Reduction Option 1:
   Injection

   Domestic septage shall be injected below the surface of the
   land, AND no significant amount of the domestic septage
   shall be present on the land surface within one hour after
   the domestic septage is injected;
   Vector Attraction Reduction Option 2:
   Incorporation

   Domestic septage applied to the land surface shall be
   incorporated into the soil surface plow layer within six (6)
   hours after application;

                         or

   Vector Attraction Reduction Option 3:
   pH Adjustment

   The pH of domestic septage shall be raised to 12 or higher
   by addition of alkali  material and, without the addition of
   more alkali material, shall remain at 12 or higher for 30
   minutes.
Figure 11-3.  Part 503 vector attraction reduction options for
            domestic septage applied to agricultural land, for-
            ests, or reclamation sites (U.S. EPA, 1993).

11.2.5  Restrictions on Crop Harvesting,
         Animal Grazing, and Site Access

As discussed above, the Part 503 regulation for domes-
tic septage application to agricultural land, forests, or
reclamation  sites includes various restrictions on the
crops harvested and animals grazed on the site, as well
as access to the site  by the public. The requirements
are less restrictive  if  the domestic septage has  been
alkali stabilized. Figures 11-1 and 11-2 summarize crop,
grazing, and public access  restrictions  for untreated
and  alkali-stabilized  domestic  septage,  respectively
(U.S. EPA, 1993). It is recommended that land appliers
of domestic septage inform the owner/operator of the
land where  the  domestic septage  has  been applied
about these crop harvesting and site access restriction
requirements.

For  more detailed  information,  see EPAs Domestic
Septage Regulatory Guidance (U.S.  EPA, 1993) and 40
CFR Part 503. It is  important to note that state regula-
tions may differ and  be more restrictive  than  the re-
quirements outlined in Figures 11-1  and 11-2.

11.2.6  Recordkeeping and Reporting

Records must be kept  by a land applier of domestic sep-
tage for five years after any application of domestic sep-
tage to a site, but Part  503 does not require land appliers
of domestic septage to report this information. These re-
quired  records might be requested for review at any time
by the  permitting  or enforcement authority (U.S.  EPA,
                    Certification3

   I certify under penalty of law that the  pathogen
   requirements  in [insert pathogen reduction alter-
   native 1 or 2] and the vector attraction  reduction
   requirements in [insert vector reduction alternative
   1,  2,  or 3] have/have not [circle one] been  met.
   This determination has been made under my di-
   rection and supervision  in accordance with the
   system designed to ensure that qualified person-
   nel properly gather  and evaluate the information
   used to determine that the pathogen requirements
   and the vector attraction reduction requirements
   have  been met. I am aware that there are signifi-
   cant penalties for false certification, including the
   possibility of fine and imprisonment.

          Signed:
          (to be signed by the person designated
          as responsible in the firm that applies
          domestic septage)
a EPA is proposing changes in the certification language.

Figure 11-4.  Certification of pathogen reduction and vector at-
            traction requirements (U.S. EPA, 1994b).
1993). The retained  records  must include the informa-
tion shown in Figure  11-5 and a written certification  (see
Figure 11-4).  EPAs Domestic Septage Regulatory Guid-
ance (U.S.  EPA, 1993)  contains  examples of ways  to
organize record keeping for sites where domestic sep-
tage is land applied.
    The location of the site where domestic septage is applied
    (either the street address, or the longitude and latitude of
    the site, available from U.S. Geological Survey maps).
    The number of acres to which domestic septage is applied
    at each site.
    The date and time of each domestic septage application.

    The nitrogen requirement for the crop or vegetation grown
    on each site during the year. Also, while not required,
    indicating the expected crop yield would help establish the
    nitrogen requirement.

    The rate  (in gallons per acre) at which domestic septage is
    applied to the site during the specified 365-day period.

    The certification shown in Figure 11-4.
    A description of how the pathogen requirements are met
    for each volume of domestic septage that is land applied.
    A description of how the vector attraction reduction
    requirement is met for each volume of domestic septage
    that is land applied.
Figure 11-5.  Part 503 5-year recordkeeping requirements (U.S.
            EPA, 1993).
                                                      133

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11.2.7  Part 503 Required Management
        Practices

Certain management practices for the land application
of all types of sewage sludge, including domestic sep-
tage, are included in Part 503. These management prac-
tices require that the land application of sewage sludge
and domestic septage does not adversely affect endan-
gered or threatened species; does not take place during
flooded, frozen or snow-covered conditions; and  does
not occur within  33 ft (10 m) of wetlands or  surface
waters (U.S. EPA, 1994b). For additional information on
these management practices, see Chapter 3.

11.2.8  State Requirements for Domestic
        Septage

The Part  503 regulation sets minimum requirements for
land application of domestic septage that must be met in
all states. States may, however, adopt (or continue to
use) regulations that are more stringent than the federal
rule.

State regulations for domestic septage use or disposal
vary widely. In most  cases, states require a hauler to
submit for approval use or disposal plans for domestic
septage. Most states also provide recommendations on
how  domestic septage should be land  applied  (U.S.
EPA,  1994b). In  addition, states usually issue hauler
licenses, although some states delegate this authority to
counties or other municipal agencies (U.S. EPA,  1994b).

Since promulgation of the Part 503 federal regulation,
many states  have  reviewed  their regulations  regard-
ing land application of sewage  sludge and domestic
septage. Those states that have regulations less  strin-
gent than the federal regulation will likely change  state
regulations to meet the minimum federal require-
ments (U.S. EPA, 1994b). For further assistance with
applicable state regulations, contact your state septage
coordinator.

11.3 Adjusting the pH of Domestic
      Septage

The  Part 503 regulation regarding land  application of
domestic septage is less burdensome if alkali stabiliza-
tion is practiced. Stabilization is a treatment  method
designed  to  reduce  levels of pathogenic  organisms,
lower the  potential  for putrefaction,  and reduce odors.
Stabilization methods for domestic septage are summa-
rized in Table 11-4 (U.S. EPA, 1994a). The simplest and
most economical technique for stabilization of domestic
septage is pH adjustment.  Usually,  lime  is added to
liquid domestic  septage in quantities sufficient to in-
crease the pH of the septage to at least 12.0 for 30
minutes (U.S. EPA, 1994b). If the lime is added before
or during  pumping of the septic tank, in many cases 30
minutes will elapse before the truck reaches the land
application  site.  Other stabilization options,  such as
aerobic digestion, are relatively simple but have higher
capital and operating  costs  (U.S. EPA, 1994b),  and
cannot be used  to meet Part  503 domestic septage
treatment requirements (for application  to agricultural
land, forests, or reclamation sites).

To raise the pH of domestic septage to  12 for 30  min-
utes, sufficient alkali (e.g., at  a  rate of 20 Ib to 25  Ib of
lime [as CaO  or quicklime] per  1,000 gal [2.4  kg to 3.6
kg per 1,000 L]) of domestic septage typically is needed,
although septage characteristics and lime requirements
vary widely (U.S.  EPA, 1994b). EPA recommends the
following approaches for alkali stabilization prior to  land
application (U.S. EPA,  1994b):

• Addition of alkali slurry to  the hauler's truck before
  the  domestic septage is pumped into  the truck,  with
  additional alkali added as necessary after pumping.

• Addition of alkali slurry to the domestic septage  as it
  is pumped from the septic tank into the hauler's truck.
  (Addition of dry alkali to a truck during pumping  with
  a vacuum pump system is  not recommended;  dry
  alkali will be pulled  through  the liquid and into  the
  vacuum pump, causing damage to the pump.)

• Addition of either alkali slurry  or dry alkali to a holding
  tank containing  domestic septage that has been dis-
  charged from a pumper truck.

Many states allow domestic septage  to  be alkali-stabi-
lized within the truck.  Some  states,  however, prohibit
alkali  stabilization in the hauler's truck  and require a
separate holding/mixing tank  where alkali addition  and
pH  can be easily monitored. A separate holding  and
mixing tank is preferred for alkali stabilization for the
following reasons  (U.S. EPA,  1994b):

• More rapid  and uniform mixing  can be achieved.

• A separate holding and mixing tank affords more  con-
  trol  over  conditions  for handling and metering  the
  proper quantity  of alkali.

• Monitoring of pH is easier,  and more  representative
  samples are likely to  be collected due to better mixing.

• Raw domestic septage can be visually inspected.

To  prevent damage to vacuum pumps and  promote
better mixing of the alkali and domestic  septage, alkali
should be added  as a  slurry (U.S. EPA, 1994b).  The
slurry can be added to the truck before pumping  the
tank, although the amount of alkali necessary to reach
pH  12 will vary from load to load.  Provisions should be
made to carry additional alkali slurry on board  the truck
to achieve the necessary dosage (U.S. EPA, 1994b).

Compressed air injection through a coarse-bubble dif-
fuser system is the recommended system for mixing the
contents of a domestic septage holding tank. Mechanical
                                                 134

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Table 11-4.  Summary of Domestic Septage Stabilization Options (U.S. EPA, 1994b)

Method               Description                      Advantages
                                                                Disadvantages
Alkali stabilization3
Aerobic digestion
Anaerobic digestion
Composting
                      Lime or other alkaline material
                      is added to liquid domestic
                      septage to raise pH to 12.0 for
                      minimum of 30 min.
Domestic septage is aerated for
15 d to 20 d in an open tank to
achieve biological reduction in
organic solids and odor
potential. (Time requirements
increase with lower
temperatures.)

Domestic septage is retained for
15 d to 30 d in an enclosed
vessel to achieve biological
reduction in organic solids.
Liquid domestic septage or
domestic septage solids are
mixed with bulking agent (e.g.,
wood chips, sawdust) and
aerated mechanically or by
turning. Biological activity
generates temperatures
sufficiently high to destroy
pathogens.
Very simple; minimal operator
attention.

Low capital and O&M costs.
Provides temporary reduction in
sulfide odors.

Meets EPA criteria for reduction
in vector attraction.

Reduces EPA site restriction
requirements for land application.

Relatively simple.

Can provide reduction in odors.
Generates methane gas, which
can be used for digester heating
or other purposes.
Final product is potentially
marketable and attractive to
users as soil amendment.
                                                                Increases mass of solids
                                                                requiring disposal.

                                                                Handling of lime may cause
                                                                dust problems.

                                                                Lime feed and mixing
                                                                equipment require regular
                                                                maintenance.
High power cost to operate
aeration system.

Large tanks or basins required.

Cold temperatures require much
longer digestion  periods.

Requires skilled  operator to
maintain  process control.

High maintenance requirements
for gas handling equipment.

High capital costs.

Generally not used except for
co-treatment with sewage
sludge.

Costly materials handling
requirement.

Requires skilled  operator
process control.

High odor potential.
High operating costs.
 Only alkali stabilization meets Part 503 domestic septage treatment requirements.
mixers  are not recommended because they often be-
come fouled with rags and  other debris present in the
septage (U.S.  EPA, 1994b).

Figure  11-6  presents a procedure for alkali-stabilizing
septage within  the pumper truck.  Methods   recom-
mended by  domestic septage servicing professionals
are presented in Domestic Septage Regulatory Guid-
ance (U.S. EPA, 1993),  along with associated cautions.

If pH adjustment is used for domestic septage, the Part
503 requirements apply to each truckload unless pH
adjustment was done  in  a  separate treatment device
(e.g., lagoon or tank) (U.S. EPA,  1993).

11.3.1   Sampling for pH

Land appliers of domestic septage should not automat-
ically assume that the lime or other alkali material added
to domestic septage and  the  method of mixing chosen
will adequately increase pH. The pH  must be tested.  A
representative sample should be taken from the body  of
                                     the truckload or tank of domestic septage for testing. For
                                     example, a sampling container could be attached to a rod
                                     or board and dipped into the domestic septage through
                                     the hatch on top of the truck or tank or through a sampling
                                     port (U.S. EPA, 1993). Alternatively, a sample could be
                                     taken from the  rear discharge valve at the bottom of the
                                     truck's tank. If the lime has settled to the bottom of the tank,
                                     however, and has not been properly mixed with the do-
                                     mestic septage, the sample will not be representative.

                                     Two  separate  samples should be taken 30 minutes
                                     apart, and both of the samples must test at pH 12 or
                                     greater  (with the pH reading converted to an equivalent
                                     value at 25°C to account for the influence of hot and cold
                                     weather on meter  readings). If the pH is not at 12 or
                                     greater  for a full 30 minutes,  additional alkali  can be
                                     added and mixed with the domestic septage. After mix-
                                     ing in the additional alkali, however, the domestic sep-
                                     tage must be at 12 or greater for a full 30 minutes to
                                     meet the pH requirement of the Part 503  regulation
                                     (U.S. EPA, 1993).
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Purpose      To raise the pH of domestic septage to 12 for a
             minimum of 30 min.
Approach     • Add lime slurry in sufficient quantity before
               pumping the tanks and add additional slurry as
               needed after pumping.
             • Add lime slurry in sufficient quantity during
               pumping of the tanks by vacuuming slurry
               through small suction line fitted to main suction
               hose.
Type of lime   • Pulverized quicklime (CaO).
             • Hydrated lime (Ca(OH)2).

             (Less quicklime is required than is hydrated lime
             to achieve the same pH, but quicklime is more
             corrosive and  difficult to handle.)
Dosage       Typically 20 Ib to 25 Ib quicklime per 1,000 gal of
             domestic septage (or about 26 Ib to 33 Ib of
             hydrated lime  per 1,000 gal).
Slurry        Approximately 80 Ib of pulverized quicklime or
             hydrated lime  in 50 gal of water. Mix mannually
             with paddle in a 55-gal drum or in a 200-gal
             polyethylene tank with electric mixer (preferred).
             CAUTION: Heat is liberated when quicklime is
             added to water. Wear rubber gloves, appropriate
             respirator (for  dust), and goggles. Add  lime slowly
             to partially full tank, an emergency eyewash
             station should be located nearby.
Application    Typically 12 to 15 gal quicklime slurry per 1,000
rate          gal of domestic septage (or 15 gal to 20 gal
             hydrated lime  slurry).
Monitoring    After lime slurry has been mixed with domestic
             septage, collect sample from top access hatch using
             a polyethylene  container fastened to a pole. Measure
             pH with pH meter at 25°C (or convert  reading to
             25°C). (pH paper can also be used, but it is more
             cumbersome and less accurate.) If the pH is less
             than 12, add more slurry. If pH 12 has been reached,
             record pH and  time. Sample again after 15 min. If the
             pH has dropped below 12, add more lime. The pH
             must remain at 12 for at least 30 min.  Sample and
             record pH prior to applying septage to the land.
Figure 11-6.  Procedure for  lime-stabilizing domestic septage
            within the pumper truck (U.S. EPA,  1994b).


11.4  Methods of Application

The most  common,  and usually  most  economical,
method for using or disposing domestic septage is land
application  (e.g.,  land spreading,  irrigation,  incorpora-
tion). Various options for land applying domestic sep-
tage are summarized in Table 11-5  (U.S. EPA,  1994b).

The simplest application method involves a hauler truck
applying domestic septage by opening a valve and driv-
ing across the land application  site. A splash  plate  or
spreader plate improves  domestic septage distribution
onto the soil surface. The domestic septage  should be
discharged  through a simple screen or basket located
on the truck between the outlet  pipe and the spreader
plate. This  screen  prevents nondegradable materials
such as  plastics  and other objectionable trash  from
being applied to the soil. A simple box screen can be
fabricated from expanded metal. Collected  trash should
be  lime-stabilized and sent to a sanitary landfill.  The
domestic septage must be lime-stabilized prior to  sur-
face application, injected below the surface, or plowed
into the soil within 6 hours of application to meet federal
Part 503 requirements for vector attraction  reduction
(U.S. EPA,  1994b).

While relatively easy, the application method described
above also  is the least flexible  and is difficult to control
from a management perspective.  In addition, soil  may
become compacted, and trucks  not designed for off-
road use may have difficulty driving  on the site. Small,
rural  land application  operations  where  little  environ-
mental or human health risk is  likely to occur, however,
may find this approach  acceptable. A transfer or storage
tank must be available when sites are inaccessible due
to soil, site, or crop conditions (U.S.  EPA, 1994b).

Another common approach is to use a manure spreader
or  a  special  liquid-waste application  vehicle that re-
moves screened domestic septage from a holding  tank
and spreads it on or injects it below  the soil surface. If
the domestic septage  is incorporated into the soil by
plowing  or is injected,  pH  adjustment may  not be
required to meet the Part 503 vector attraction reduc-
tion requirements (U.S. EPA, 1994b). If pH adjustment
is done, this also meets some  of the Part 503 require-
ments for pathogen reduction. Figure  11-7 illustrates
a subsurface injection  device that injects either a wide
band or several  narrow  bands of domestic septage
into a cavity 10-15 cm  (4 to 6 in) below the soil surface
(U.S. EPA,  1980).

A third  approach is to pretreat the  domestic septage
(with  a  minimum of screening) during discharge into a
holding/mixing tank by adding  lime and stabilizing  it to
pH  12 for 30  min, and  then to spray the domestic  sep-
tage onto the land surface using commercially available
application equipment.  Adjustment of pH reduces odors
and eliminates the  need to  incorporate  the domestic
septage into the soil (U.S. EPA, 1994b).
 Cross-Section/Sub-Surface
     Injection Process
Injector Shank
  and Hose
  initial Injection
    Cavity
                          Ultimate Dispersion
                          Area Alter Injection

Figure 11-7.  Subsurface soil  injection (Cooper and  Rezek,
            1980).
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Table 11-5.  Summary of Land Application Methods for Domestic Septage (U.S. EPA, 1994b)

Method             Description                     Advantages                     Disadvantages

Surface Application (for all surface application methods, domestic septage must be incorporated into soil within 6 hrs if the pH is
not adjusted and if the septage is applied to agricultural land, forest, or a reclamation site.)
Spray irrigation
Ridge and furrow
irrigation


Hauler truck
spreading
Farm tractor and
wagon spreading
Pretreated (e.g., screened)
domestic septage is pumped
through nozzles and sprayed
directly onto land.
Pretreated domestic septage is
applied directly to furrows.


Domestic septage is applied to
soil directly from hauler truck
using a splash plate to improve
distribution.
Domestic septage is transferred
to farm equipment for spreading.
Can be used on steep or rough
land.

Minimizes disturbance of soil by
trucks.
Lower power requirements and
odor potential than spray
irrigation.

Same truck can be used for
transport and disposal.
Increases opportunities for
application compared to hauler
truck spreading.
Large land area required.

High odor potential during application.

Storage tank or lagoon required during
periods of wet or frozen ground.

Potential for nozzle plugging.

Limited to 0.5% to 1.50% slopes.

Storage lagoon  required.

High odor potential during and
immediately after spreading.

Storage tank or lagoon required during wet
or freezing conditions.

Slope may limit  vehicle operation.

Hauler truck access limited by soil
moisture; truck weight causes soil
compaction.

High odor potential during and
immediately after spreading.

Storage tank or lagoon required.

Requires additional equipment (tractor and
wagon).
Subsurface Incorporation
Tank truck or
farm tractor with
plow and  furrow
cover
Subsurface
injection
Liquid domestic septage is
discharged from tank into furrow
ahead of single plow and is
covered by second plow.
Liquid domestic septage is
placed in narrow opening
created by tillage tool.
Minimal odor and vector
attraction potential compared
with surface application.

Satisfies EPA criteria for
reduction of vector attraction.

Minimal odor and vector
attraction potential compared
with surface application.

Satisfies EPA criteria for
reduction of vector attraction.
Slope may limit vehicle operation.

Storage tank or lagoon required during
periods of wet or frozen ground.
Slope may limit vehicle operation.

Specialized equipment and vehicle may be
costly to purchase, operate, and maintain.

Storage tank or lagoon required during wet
or frozen conditions.
11.5  Operation and Maintenance at Land
       Application Sites Using Domestic
       Septage

Key elements  of a successful operation and mainte-
nance program for a domestic septage land application
site include (U.S. EPA, 1994b):

• Provision  of receiving and  holding  facilities for the do-
  mestic septage to provide operational flexibility (optional).

• Proper domestic  septage  treatment  prior to applica-
  tion as required to meet federal and state regulations
  (need for treatment depends on requirements of ap-
  plication method).
                                          •  Control of  domestic septage  application  rates and
                                             conditions in accordance with federal and state rules.

                                          •  Proper operation and maintenance of the application
                                             equipment.

                                          •  Monitoring of domestic septage volumes and charac-
                                             teristics, as well as soil, plant, surface water and ground
                                             water as required by federal and state regulations.

                                          •  Odor control.

                                          •  Good  recordkeeping and retention of records  for at
                                             least 5 years.
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Odor problems should not arise at a site where domestic
septage is land applied if the requirements of Part 503
are followed. A well-managed operation that uses pH
adjustment and practices  subsurface injection or sur-
face application/incorporation  at or below  agronomic
rates (see Section  11.2.1.1) will create minimal odor
emissions.  Additional guidelines for minimizing odor
problems at land  application sites are presented  in
EPAs Guide to Septage Treatment and Disposal (U.S.
EPA, 1994b).

Operation and maintenance requirements for land appli-
cation  of domestic septage  vary widely depending on
the application technique and  the type of equipment used.

11.6  References

When  an  NTIS number  is  cited in a  reference, that
document is available from:
   National Technical Information Service
   5285 Port Royal Road
   Springfield, VA 22161
   703-487-4650
U.S. EPA. 1994a. A plain English guide to the Part 503 biosolids rule.
   EPA/832/R-93/003. Washington, DC.

U.S. EPA. 1994b. Guide to septage treatment and disposal. EPA/625/
   R-94/002. Cincinnati, OH.

U.S. EPA. 1993. Domestic septage regulatory guidance: A guide to
   the Part 503 rule. EPA/832/B-92/005. Washington, DC.

U.S. EPA. 1992a. Technical support document for land application of
   sewage sludge. EPA/822/R-93/001a (NTIS PB93110583). Wash-
   ington, DC.

U.S. EPA. 1992b. Environmental regulations and technology: Control
   of pathogens and vector attraction in sewage sludge. EPA/625/R-
   92/013. Washington, DC.

U.S. EPA. 1980. Septage management. EPA/600/8-80/032. (NTIS PB
   81142481). Washington, DC.
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                                            Chapter 12
                                       Public Participation
12.1  Introduction

A critical factor in establishing a sewage sludge  land
application program in most communities is the partici-
pation of local citizens from the beginning and at various
key stages of the project's development. If not given the
opportunity to discuss their concerns, whether based on
legitimate  issues  or misperceptions,  resistance from
members of the community can significantly complicate
a project and result in additional costs.  Moreover, if the
public's  viewpoint is ignored until late  in the planning
process, opposition  within the community may solidify
and be difficult to overcome. Thus,  public participation
is as important a factor as any technical  consideration
in establishing a sewage sludge land application system
(Lue-Hing et al., 1992). Public involvement in the deci-
sion-making process will  help to minimize opposition
and to identify the major barriers to local acceptance
(U.S. EPA, 1984).

A sewage sludge land application project has the best
chance  of gaining public acceptance  if  a public  out-
reach effort is organized to stress the demonstrated
value of sewage sludge as a resource.  Once accep-
tance has been achieved, it is most likely to be main-
tained through conscientious management of the site
during operations.

In general, the public's willingness to participate in—and
ultimately accept—the siting of a sewage sludge  land
application site will depend on:

• An understanding of the need for the project regard-
  ing its costs and benefits.

• A sense of confidence that the project will adequately
  protect public health and safeguard the environment.

• Encouragement of active public involvement in  pro-
  ject development so that local interests can be fac-
  tored  into the plan.

Planning for public participation in the siting of a sewage
sludge land  application site involves careful and early
evaluation of what should be communicated, to whom,
by whom, and when. This chapter summarizes the major
considerations for implementing a successful public par-
ticipation program, including the objectives and value of
a public participation, the design and timing of a pro-
gram, and topics generally of public concern regarding
the land application of sewage sludge.

12.2 Objectives

The objectives of a public participation program are:

• Promoting a full and accurate  public understanding
  of the advantages and  disadvantages of land  appli-
  cation of sewage sludge.

• Keeping the public well-informed about the status of
  the various planning, design, and operation aspects
  of the project.

• Soliciting  opinions,  perceptions,  and suggestions
  from concerned citizens involving the land application
  of sewage sludge.

The key to achieving these objectives  is to establish
continuous two-way communication between the public
and the land application site planners, engineers, and
eventual  operators (Canter,  1977).  Officials need  to
avoid the  common assumption that  educational and
other one-way communication techniques will promote
adequate dialogue. A public participation plan should
focus generally on moving people from the typical reac-
tive response to sewage sludge issues to an informed
response about sludge management  (Lue-Hing et al.,
1992).

To generate meaningful public participation in the deci-
sion-making process, the  public agency or engineering
firm directing the project needs to take particular steps
at each stage of project development (see Section 12.3).
The additional effort  involved  in soliciting  community
input for establishing a  land application site should be
considered when making an initial determination  about
the best approach for managing the community's sew-
age sludge.

12.3 Implementation of a Public
      Participation  Program

A program for soliciting  public participation in the siting
of a sewage sludge land application site  should be
tailored to fit the scale and costs of the particular project.
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Nonetheless, a  basic framework for a  program  that
would be applicable for most situations includes:

• The initial planning stage

• The site selection  stage

• The site design stage

• The site preparation and operation stage

These four stages are described below.  Beyond  this
basic framework, officials should use a common-sense
approach for determining the extent of the public partici-
pation program and the frequency at which public input
should  be solicited.  When time and  money are con-
straining  factors, officials will need to concentrate re-
sources on the most effective mechanisms for community
involvement (see Table 12-1). Regardless of its scope,
however, the public participation program will need to be
flexible enough to accommodate various issues that can
arise in the course of establishing a sewage sludge land
application site.

Table 12-1.  Relative Effectiveness of Public Participation
           Techniques
                       Communication Characteristics
Public Participation
Technique
Public hearings
Public meetings
Advisory Committee
meetings
Mailings
Contact persons
Newspaper articles
News releases
Audiovisual
presentations
Newspaper
advertisements
Posters, brochures,
displays
Workshops
Radio talk shows
Tours/field trips
Ombudsman
Task force
Telephone line
Level of
Public
Contact
Achieved
M
M
L
M
L
H
H
M
H
H
L
H
L
L
L
H
Ability to
Handle Degree of
Specific Two-Way
Interest Communication
L
L
H
M
H
L
L
L
L
L
H
M
H
H
H
M
L
M
H
L
H
L
L
L
L
L
H
H
H
H
H
M
L = low value
M = medium value
H = high value
12.3.1  Initial Planning Stage

12.3.1.1   Establishing an Advisory Committee

During the initial planning stage, the scope and scale of
the public  participation program is decided, and imple-
mentation  of the program is then initiated. To facilitate
and follow through with this effort, officials in charge of
the land application project should organize an advisory
committee made up of members of the community. The
committee should include, for example, representatives
of local government, community organizations, and area
businesses (Table 12-2). Since in rural communities the
acceptance of local farmers is particularly important for
a proposed land application program, this group should
also be represented on the  committee where appropri-
ate (see Section 12.4.1). The Soil Conservation Service,
county Extension Agents, and Farm Bureau can provide
vital links with the farming community (U.S. EPA, 1984).

The primary responsibility of the advisory committee
should  be  to organize the community's involvement in
project  planning. The  overall strategy for informing the
community about the land  application  project and re-
sponding to concerns  should be  put in writing. Addition-
ally, the committee  could be called upon to provide initial

Table 12-2.  Potential Advisory Committee Members (Canter,
           1977)

The following groups  and individuals should be contacted
about serving on the advisory committee:
• Local elected officials.
• State and local government agencies,  including planning
  commissions, councils of government, and individual agencies.
• State and local public works personnel.
• Conservation/environmental groups.
• Business and industrial groups, including chambers of commerce
  and selected trade and industrial associations.
• Property owners and users of proposed sites and neighboring
  areas.
• Service clubs and civic organizations, such as the League of
  Women Voters.
• The media, including newspapers, radio, and television.
The following groups  should also be contacted, where
appropriate:
• State elected officials.
• Federal agencies.
• Farm organizations.
• Educational institutions, including universities, high schools, and
  vocational schools.
• Professional groups and organizations.
• Other groups and organizations, such as urban groups, economic
  opportunity groups, political clubs and associations.
• Labor unions.
• Key individuals who do not express their preferences through, or
  participate in, any groups or organizations.
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feedback on various project proposals and to function
generally as a liaison between the project staff and the
community at  large.  In its role as liaison, an  advisory
committee would be  responsible for receiving  commu-
nity input and obtaining responses to questions. A useful
practice in this regard is to keep a log of requests for
information and responses given. For especially large
projects, it might be feasible to hire a public information
professional to assist in this capacity.

When making  its assessment about the appropriate ex-
tent of the public outreach effort, the advisory commit-
tee's planning should address when and  how often to
use particular mechanisms for encouraging participation
in the land application project. The two general types of
program mechanisms are:

• Educational. Those that allow project staff to present
  information to members of the community.

• Interactive. Those  that are intended to solicit input
  from members of the community.

Throughout the public participation program, the advi-
sory committee should be developing its mailing and
telephone lists. Such lists, which should be continually
updated and expanded by capturing the names  of citi-
zens who attend  public meetings or otherwise make
contact with the committee, can prove indispensable for
keeping the community involved in the land application
project. Contact by mail and telephone can be used to
alert the community to meetings and developments, or
to  provide followup information to citizens  who have
expressed particular concerns about the project.

12.3.1.2   Educating the  Community

After establishing an  advisory committee, the next step
in program implementation is to undertake  a public edu-
cation campaign, which typically is kicked  off at a well-
publicized public meeting or at a series  of meetings
targeted for specific groups within  the community.

The level of interest  in waste management issues  for
most people is fairly low. Thus, while members  of the
community at  large should be targeted by the  public
education campaign, it is particularly important to reach
members  of environmental groups, the  media, and
elected officials. The participation  of such members of
the community is  important because they are likely to
have broad  affiliations and the ability to  affect  public
opinion on a large scale (WEF,  1992).

At a public meeting  it is  important to present general
information about the land application project and to
encourage the community to take an active interest in
the project's development. Presenters at  this  meeting
might include project staff and engineering consultants.
The meeting is also a good opportunity to introduce the
members  of the  advisory committee—stressing the
breadth of representation from the various sectors of the
community—and explain the committee's role. Informa-
tion about the project presented at the community meet-
ing should cover:

• The  need for the land application program.

• The  reason for selecting  land application  over other
  approaches  for managing sewage sludge, such as
  surface disposal or incineration.

• The use of crops or other vegetation grown  on the site.

• The  general costs associated with design, construc-
  tion,  and operation of the program.

• The  potential economic incentives, such as job crea-
  tion and stimulation of the local economy.

• The program's general design and operation principles.

It may  be useful to supplement presentations given at
the meeting with handouts that provide, for instance, a
brief explanation of sewage sludge and how  it is gener-
ated; a nontechnical summary of the Part 503 rule; the
professional experience of engineers and others design-
ing the land application program; and a list project con-
tacts. Video support, if available,  might also be useful
for providing  additional  general  information  at  the
meeting.

A community's specific concerns, particularly about pro-
tecting  public health and safeguarding the environment,
can be enough to undermine  a technically strong plan
for establishing a  land application  operation. Thus, it is
advisable to make information available about how land
application programs operating over  long periods (e.g.,
10 years  or more) in other communities have  addressed
these concerns (Jacobs et al., 1993).

Once the sewage sludge land application project has
been introduced at a public meeting to interested mem-
bers of the community, informational outreach to the
general public can be  achieved primarily through the
local media. Since public meetings are ineffective infor-
mation outlets for certain segments of any community,
however, the outreach effort should include placing paid
advertisements, if feasible, as well as encouraging the
media contacts made at the public meeting to report on
the project. At some point after providing the  media with
general information about the proposed land application
site, it may be useful to develop a press kit for distribu-
tion. Providing project-specific information to the media
will increase the accuracy of information reported to the
public (Lue-Hing et al.,  1992).

The more types of media that are  used to promote the
project, the  greater the likelihood  of a successful  out-
reach effort. For example,  a variety of media could be
used as follows:
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• Newspapers reports. A series of articles on land ap-
  plication of sewage sludge could be timed to appear
  throughout the project to sustain public interest. Also,
  occasional news releases would keep the community
  informed about developments.
• Television reports. At a minimum, it should be possi-
  ble to arrange for coverage of milestone project de-
  velopments. It also might be possible to interest news
  producers in developing a series about the project.
• Newspaper, television,  and radio advertisements. In-
  formational advertisements can be  used to publicize
  critical information about the project. Although televi-
  sion advertising tends to be  expensive, it  can be
  particularly effective  for reaching a majority of the
  community. Radio advertising, especially if broadcast
  during the morning or afternoon commute,  can be
  equally effective while less expensive.

• Public service announcements and editorials. Radio
  and television stations are required to offer a limited
  amount of broadcast time for airing announcements
  or editorials of general  interest in the local area. Ca-
  ble television stations  may have specific program-
  ming devoted to local issues. Also,  newspapers may
  welcome an informed opinion piece for the op-ed page.
Posters,  brochures, and  displays also can  be highly
effective educational tools, especially when designed
creatively and placed in high-traffic areas or given wide
distribution.

12.3.1.3   Soliciting Community Input and
          Addressing Concerns

After the public has been generally informed about the
sewage sludge land application project,  the  advisory
committee should begin concentrating its efforts on so-
liciting community input on the  project plan. For this
phase of the public participation  program, various types
of forums can be useful for focusing on and responding
to the community's concerns about the project. Con-
cerns that are likely to surface include:
• Public safety and health. As noted  above, this issue
  can be of primary interest to the community.  Thus, it
  is  important to emphasize the extensive research on
  risk  assessment and  environmental impacts  that
  serves as the basis for the Part 503 rule. Also,  pro-
  ject-specific management systems should  be ex-
  plained. In particular, the community may need to be
  reassured that  a system has  been developed  for
  avoiding spills of sewage sludge during transport.

• Contamination of water supplies. The public generally
  has developed a heightened awareness about water
  quality issues. As  a  result, the public is better pre-
  pared to raise water quality  issues and to  consider
  measures taken to safeguard water supplies.  The
  community should be made aware that Part 503 spe-
  cifically addresses protection of ground water  and
  surface waters by, for instance, restricting runoff from
  application sites and limiting the potential for leaching
  of pollutants into ground water.

• Accumulation of heavy metals and toxics. The public
  may be inclined to assume that  sewage sludge  is
  associated  with   excessive  contaminants,  since
  "waste" is synonymous with "toxic" in many people's
  minds  (Lue-Hing et al., 1992). Thus, public informa-
  tion efforts should stress the proven beneficial char-
  acteristics  of sewage sludge   and  explain  the
  regulatory limits on the loadings of 10 heavy metals
  associated with sewage sludge.

• Regulatory compliance. The community is  likely to
  question whether the site will be monitored by public
  officials for regulatory compliance. This concern can
  be addressed by explaining the role of the permitting
  authority in enforcing the Part 503 rule and by review-
  ing the legal recourse available to officials (e.g., fines
  of up to $25,000 per day for a single violation).

• Odor, noise, dust, and traffic. Because odors are usu-
  ally the first cause of complaints when  a land appli-
  cation  site is sited near a residential area, sewage
  sludge at such sites should be injected or disked into
  the soil immediately following application (Jacobs et
  al., 1993). The site management plan should  specifi-
  cally cover such measures, as well  as  measures to
  control noise and dust from the operation of machin-
  ery and limit traffic in and out of the site.

• Land values. The community is likely to be concerned
  about the  impact of the land application  operation on
  real estate values.  This issue should be investigated
  and the community should be informed of any poten-
  tial for a drop in  values. Regarding this  and other
  concerns, it may be useful to cite the experience of
  other communities with a  land application program
  (Jacobs et al., 1993).

Both formal  and informal approaches can be effective
for soliciting and then responding to the  community's
concern about the land application project. Regardless
of the forum, however, it is essential that advantages as
well as disadvantages be addressed openly. When there
is a  void of information, it is likely to get  filled with
distorted  portrayals based on assumptions  and emotion.
It is  far better to fill that void with factual information
(Lue-Hing et al., 1992).

Forums that can  be effective for  public participation
include meetings and workshops, as well as site tours
that include  demonstrations. The appropriateness  of a
particular forum will depend on the stage of the project's
development.
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12.3.2   Site Selection Stage

The site selection process involves screening an array
of potential  locations for the land application facility,
followed  by detailed  field  investigations that include
water and soil sampling at a handful of candidate sites.
Once the  project staff has narrowed the choices  down
to a  few sites and  gathered  a  reasonable amount of
comparative data, the public should be brought into the
process.

Depending on the scope of the project and the location
of candidate sites  relative  to population  density,  the
appropriate forum for public participation at this  stage
would be a targeted meeting or a workshop gathering.
If a site close to a  residential area is being  seriously
considered,  neighboring residents will  have  a vested
interest in selection and want detailed information  about
such issues as public safety,  odor control, and impact
on land values.  Indeed, project staff may need to antici-
pate vocal, organized resistance to  the site. Meeting
with  interested  parties in  smaller groups  can  be an
effective  means of  diffusing such emotionally loaded
issues. Targeted meetings and workshops have particu-
lar characteristics that are advantageous at this stage of
project development:

• Targeted meetings. Meeting  with  members of  the
  community who have a particular interest in the pro-
  ject can be an efficient means of addressing site-spe-
  cific concerns.  A useful approach is to  give  the
  community an opportunity to  discuss issues directly
  with project engineers, the prospective site manager,
  and  members  of the  advisory committee. These
  smaller meetings  should  be less structured than  the
  initial, community-wide meeting so that dialogue can
  be  encouraged.  A sketchy outline should  be  used
  primarily to elicit a group's concerns, and the project
  staff should be fully prepared to respond to a range
  of issues.

• Workshops. When working  with a group that is par-
  ticularly interested in site-selection criteria, such as
  an environmental  group or the media,  a workshop is
  a useful forum for presenting and discussing informa-
  tion. A fairly structured agenda is  appropriate for a
  workshop, as long as sufficient time is scheduled for
  open discussion.  If a workshop is effective, partici-
  pants are  likely to disseminate the information  more
  broadly within the community.

To generate participation in these more focused gather-
ings, the advisory committee might want to use its tele-
phone and mailing lists to contact potentially interested
individuals. Otherwise, opposition to the site finally se-
lected could surface late in the process, when  it may be
less readily diffused. Forthe same reason, it is important
to keep the community involved through completion of
the selection  process.
When opposition to the developing plan does arise, it is
best to  meet it head  on. Recommended presentation
tactics (Lue-Hing et al., 1992) include:

• Answer all questions candidly and publicly.

• Avoid arguing over emotionally charged questions;
  emphasize generalities.

• Never reiterate incorrect information, either verbally
  or in print.

12.3.3  Site Design Stage

Because the relevant information at this stage of the
project is of a particularly technical  nature, community
interest  will be less broad-based. Nonetheless, it is im-
portant to maintain some degree of public participation.
This challenge is likely to fall to the advisory committee,
which should consider  various  and  innovative ap-
proaches for reaching the public with design informa-
tion. Suggested approaches include:

• Field  trips. A visit to a nearby operating land applica-
  tion site can be  a useful  means of informing special
  interest groups about design considerations. A project
  engineer should  accompany the group on the visit so
  that the host site can  be compared to the planned
  site.

• Video presentations. If available, a general video that
  explains site design in regard to eventual operation
  can be an effective means of involving the community
  in the project's  design stage. The video could be
  screened for small groups and followed by a question
  and answer period with project staff.

• Task forces. Assigning members of the community to
  design-related tasks that address specific public con-
  cerns can generate important input for design plan-
  ning.  To  be  most  effective, task  force members
  should have a technical orientation.

• Media campaign. Information (e.g., press releases)
  should be provided to the media  as  design mile-
  stones are reached. A guest appearance on a radio
  call-in program or a cable news program by a  project
  spokesperson might also be effective at this stage if
  it can be arranged.

Once the design for the land  application site is final, it
will need to  be formally presented to the community at
a public hearing. Such gatherings are often legally re-
quired, must be preceded by published notification to the
community, and follow a set agenda. Also, relevant ma-
terials might need to be made  available for public review
prior to  the  hearing.  The agenda for a public  hearing
usually  includes presentations by  project  staff, after
which the floor is opened for  comments from the com-
munity.  The effectiveness of the gathering  can  be en-
hanced  when an  elected official  or other prominent,
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informed figure in the community chairs the hearing or
at least participates.

12.3.4  Site Preparation and Operation Stage

While the selected land application site is  being pre-
pared  for operations, the advisory  committee should
monitor activity at the site and maintain contact with the
community. This is particularly important if buildings or
treatment structures  are  being constructed,  since the
delivery of materials and operation of heavy equipment
can  create nuisances, especially for local  residents.
Committee members should be prepared to  respond to
complaints as they arise, either on their own or with the
help of the project staff. If feasible, the project staff
should assign an ombudsman to resolve issues that
arise during  site preparation and to continue in this
capacity, at least initially, once operations are underway.

Once fully operational, the  site should continue to  be
monitored for its actual  or potential negative impacts on
the community. After an initial period of operation, the
advisory committee may want to conduct a limited tele-
phone survey to gauge how the public is feeling about
the site. The committee would then report results to the
operations staff and follow up to see that any necessary
modifications have  been made.  For example,  better
odor control practices may need to be adopted, or site
traffic may need to be restricted to specified hours.

After the advisory committee has determined that the
land application site has been generally accepted by the
community, it should provide followup information to the
media. This  is the appropriate point to  promote the
success  of the site and its advantages to the commu-
nity—not the least of which should be the beneficial use
of locally generated sewage sludge. For instance, the
community should be interested  in learning  about the
use of crops  grown on the site and whether local gar-
deners are land applying sewage sludge.

12.4 Special Considerations

12.4.1   Agricultural Sites

Implementation of an agricultural land application pro-
ject  for sewage sludge can  require acceptance and
approval by  local  officials,  farmers,  landowners, and
other affected parties. Public  resistance to agricultural
land application  of sewage  sludge can stem from fear
that the sludge may contain concentrations of organic or
inorganic substances that could  be toxic to plants or
accumulate in  animals or  humans consuming  crops
grown on sludge-treated lands.

The most critical aspect of a public participation program
in such cases is securing the involvement  of farmers
who will use the sludge. How this involvement  is to
be secured during the planning  process depends on
the individual communities involved; their past experi-
ences  with  land  application  systems; overall  public
acceptance  of the concept;  and the extent to  which
related or tangential environmental concerns are voiced
in the community.

Generally, a low-key approach  is most effective. The
various approaches can consist of one or more of the
following steps:

• Check with the wastewater treatment operator to see
  if any local farmers have requested sewage sludge
  in the past.

• Have the local Soil Conservation Service  or Agricul-
  tural Extension Service agent  poll various  individuals
  in the area.

• Describe the project in the local newspaper, asking
  interested parties to contact the extension agent.

• Personally visit the identified parties and solicit their
  participation. A telephone contact will elicit little sup-
  port  unless followed by a personal visit.

The use of demonstration plots is very effective in pro-
moting the land application of sewage sludge by farm-
ers. If farmers can compare crops grown on sludge-treated
soil with these grown with conventional fertilizer, their will-
ingness to  use sewage sludge will increase markedly
(Miller  et al., 1981). The following questions regarding
sewage sludge land application need to be discussed
with landowners:

• How long is the landowner willing to participate (e.g.,
  a trial period of 1 or more years; open-ended partici-
  pation; until  one  or both parties decide to quit; for a
  prescribed period of time)?

• What crops are traditionally planted, and what is the
  usual crop rotation?

• If the sewage sludge characteristics were such that
  a different crop is desirable, would the landowner be
  willing to plant that crop?

• Which fields would be included in the sewage sludge
  land application program?

• Under  what  conditions  would  the landowner accept
  the sewage sludge, what time of the year, and in what
  quantities?

• Is the landowner willing to pay a nominal  fee for the
  sewage sludge, accept it free  of charge, or must the
  municipality pay the landowner for accepting sludge?

• Is the landowner willing to engage in special proce-
  dures (e.g., maintaining soil pH at 6.5 or greater)?

The public participation program should emphasize both
the benefits and the potential problems of applying sew-
age sludge on  cropland.
                                                  144

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         Forest Sites
12.4.3  Reclamation Sites
To help  achieve acceptance,  a program for the land
application of sewage sludge  at a  forest site  should
satisfactorily address the following questions:

• How will public access be controlled in the application
  area for an  appropriate period (normally  12  to  18
  months) after sewage  sludge application?  Forested
  areas are often used for various recreational activities
  (e.g., picnicking, hiking, gathering of forest  products).
  Even privately owned forest land often is viewed  by
  the public as  accessible for these  purposes. The
  owner of the land, private or public, will have to agree
  to a method for controlling public access (e.g., fence,
  chain with signs). The public, through its representatives,
  must agree to  restrictions if the land  is publicly owned.

• Will public water supplies and recreational water re-
  sources be adequately protected against contamina-
  tion?  This concern should  be covered  by  proper
  siting,  system design,  and monitoring. Public health
  authorities and regulatory agencies must be satisfied
  and involved  in  the  public participation  program.
  Careful consideration must be given to municipal wa-
  tersheds  and/or drinking water recharge  areas  to
  avoid contamination.

• Will the applied sewage sludge cause adverse effects
  to the existing or future trees in the application area?
  Based on the available data  from research  and dem-
  onstration projects, many  tree species,  with few
  exceptions, respond  positively to sewage sludge
  application, provided the sludge  is not abnormally high
  in  detrimental constituents and proper management
  practices are followed.

• Unlike most agricultural applications, there is much
  less concern about  possible food chain transmission
  of contaminants to humans.  The consumption of wild
  animals by hunters  and their families  will occur, but
  there is little potential for contamination of meat from
  such animals through  contact with a  properly man-
  aged sludge application area.
Prior to the initiation of any reclamation project using
sewage sludge, it will likely be necessary to educate the
public to  gain public acceptability. The task may  be
difficult with lands disturbed by mining, because  local
opposition to mining activity  already exists  in  many
cases. This is particularly true if the mining activity has
already created some adverse environmental problems,
such as reduced local ground-water quality, acid  mine
drainage,  or serious  soil erosion and sedimentation of
local streams.

Citizens, regulatory agencies, and affected private busi-
ness entities need to  participate in the planning process
from the beginning. The most effective results are usu-
ally achieved when industry, citizens,  planners, elected
officials,  and  state and federal agencies  share  their
experience, knowledge,  and goals, and jointly create a
plan acceptable to all.


12.5  References

Canter, L. 1977.  Environmental impact assessment. New York, NY:
   McGraw-Hill, pp. 221, 222.

Jacobs, L.,  S. Carr, S. Bb'hm, and J. Stukenberg. 1993. Document
   long-term experience of biosolids land application programs. Pro-
   ject 91-ISP-4, Water Environment Research Foundation, Alexan-
   dria, VA.

Lue-Hing, C., D. Zenz, R. Kuchenrither, eds. 1992. Municipal sewage
   sludge management: Processing, utilization and disposal, Ch.  12.
   In: Water quality management library, Vol. 4. Lancaster, PA: Tech-
   nomic Publishing.

Miller, R., T.  Logan, D. Forester, and D. White. 1981. Factors contrib-
   uting to  the success of land application  programs for municipal
   sewage  sludge: The Ohio experience. Presented at the  Water
   Pollution Control Federation Annual Conference, Detroit, Ml.

U.S. EPA. 1984. Environmental regulations and technology:  Use and
   disposal  of municipal  wastewater sludge.  EPA/625/10-84/003.
   Washington, DC.

WEF. 1992.  Proceedings of the future direction of municipal sludge
   (biosolids) management: Where we are and where we're  going,
   Vol. 1, Portland, OR, July 26-30, 1992. Water Environment Fed-
   eration, Alexandria, VA. No. TT041.
                                                     145

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                                             Chapter 13
                                    Monitoring and Sampling
13.1  Overview

The Part 503 rule requires monitoring of sewage sludge
that is land applied for metal concentrations, pathogen
densities,  and vector attraction  reduction.  In addition,
soil testing for nutrients (N,  P, and K)  may be useful at
land application sites to help determine plant nutrient
needs. Additional monitoring (e.g., of water quality and
vegetation) is not required by Part 503 for land applica-
tion sites  because the rule protects  these resources
through pollutant limits, management  practices, patho-
gen reduction requirements, etc.

This chapter discusses Part 503 monitoring  require-
ments for  sewage sludge, including required analytical
methods, and specifies sampling procedures that might
be particularly useful for characterizing sewage sludge
(Section 13.2). Soil  monitoring and sampling methods
for  relevant parameters also are presented (Section
13.3). Brief discussions of surface water, ground-water,
and vegetation monitoring are included in Sections 13.4
and 13.5.  Monitoring and sampling concerns particular
to reclamation sites are discussed in Section 13.6.

State regulatory programs may have specific requirements
for monitoring sewage sludge land application sites. The
appropriate regulatory agencies should be contacted to
identify any applicable monitoring requirements.

13.2 Sewage Sludge Monitoring and
      Sampling

The  Part  503 requirements related to  monitoring for
sewage sludge that is land applied focus primarily on
sewage sludge characterization to determine pollutant
concentration, pathogen density, and vector attraction
reduction.  Required  monitoring includes:

• Monitoring of sewage sludge for 10  pollutants (As,
  Cd, Cr, Cu, Pb, Hg, Mo, Ni, Se, and Zn) to determine
  pollutant levels in sewage sludge, compared to Part
  503 pollutant limits (see Chapter 3).

• Monitoring to determine pathogen densities in sew-
  age sludge, as described in Chapter 3.

• Monitoring to ensure that  conditions for vector attrac-
  tion reduction are maintained.
Table 13-1 summarizes major considerations for moni-
toring metals, pathogens, and vector attraction reduc-
tion  in   sewage  sludge.  Another  EPA  document,
Environmental Regulations and  Technology: Control of
Pathogens and  Vector Attraction in Sewage  Sludge
(U.S. EPA, 1992), provides guidance for the monitoring,
sampling, and analysis of pathogens and vector attrac-
tion reduction efforts under Part 503 in detail and should
be consulted for further guidance. The remainder of this
section focuses on  sampling  and analysis of sewage
sludge for pollutants. For additional guidance on monitor-
ing of sewage sludge for land application, see EPAs Pre-
paring Sewage Sludge for Land Application or Surface
Disposal: A Guide forPreparers of Sewage Sludge on the
Monitoring, Record Keeping, and Reporting Requirements
of the Federal Standards for the Use or Disposal of Sew-
age Sludge, 40 CFR Part 503 (U.S. EPA, 1993).
13.2.1   Sampling Location


Sewage sludge samples must be representative of the
final sewage sludge that is land applied. To achieve this
goal, samples  must be  representative  of  the  entire
amount of sewage sludge being sampled, collected after
the last treatment process,  and taken from  the same,
correct  location  each time  monitoring is  performed.
Sampling locations should be as close as possible to the
stage  before  final  land  application.  Liquid  sewage
sludge can be sampled at the  wastewater treatment
plant from  pipelines, preflushed  pipeline ports,  or  la-
goons. Dewatered sewage sludge can be sampled at a
wastewater treatment plant from conveyors, front-end
loaders moving a pile of sewage sludge, or during truck
loading or unloading. At a land application site, dewa-
tered samples can  also be  taken on the ground after
unloading but preferably before application, or possibly
after spreading.1 Table 13-2 identifies recommended
sampling points for various types of sewage  sludge.
1 Sampling after spreading poses the risk of penalties if samples
 exceed Part 503 pollutant limits and pathogen densities or do not
 comply with the regulation's vector attraction  reduction require-
 ments. Sampling after spreading should only be done if parameters
 of concern do not vary greatly in concentration and are known to fall
 well below Part 503 limits.
                                                  147

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Table 13-1.  Monitoring Considerations for Part 503 Requirements

Parameter                         Validity of Analytical Data Over Time and When Sampling/Analysis Must Occur

                                                            Metals
Metals
                                   Data remain valid.
                                   Determine monitoring frequency in accordance with monitoring frequency requirements.
                                                     Pathogens Class A
Applies to All Class A Pathogen
Reduction Alternatives (PRA):
Fecal Coliform & Salmonella sp.
Because regrowth of fecal coliform and Salmonella sp. can occur, monitoring should be done:
(a) at the time of use or disposal,  or,
(b) when sewage sludge  is prepared for sale or give-away in a bag or other container for land
application, or
(c) when sewage sludge  is prepared to meet EQ requirements.
                                  Additional Information on Each Class A Pathogen Category
Class A PRA 1:
Thermal Treatment, Moisture,
Particle Size & Time Dependent

Class A PRA 2:
High pH, High Temperature

Class A PRA 3:
Enteric Virus & Viable Helminth
Ova to Establish Process


Class A PRA 4:
Enteric Virus & Viable Helminth
Ova for Unknown Process
Class A PRA 5:
PFRP

Class A PRA 6:
PFRP Equivalent
Data remain valid.
Time, temperature, and moisture content should be monitored continuously to ensure effectiveness
of treatment.

Monitor to ensure that pH 12 (at 25°C) is maintained for more than 72 hours for all sewage sludge.


Once reduced, enteric virus or viable helminth ova does not regrow. To establish a process,
determine with each  monitoring episode until the process is shown to consistently achieve this
status. Then continuously monitor process to ensure  it is operated as it was during the
demonstration.

Once reduced, enteric virus or viable helminth ova does not regrow. Monitor representative sample
of sewage sludge:
(a) at the time of use or disposal, or
(b) when prepared for sale or give-away  in a bag  or other container for land application, or
(c) when prepared to meet EQ requirements.

Monitor at sufficient frequency to show compliance with time and temperature or irradiation
requirements.

Monitor at sufficient frequency to show compliance with PFRP or equivalent process requirements.
                                                     Pathogens Class B
Class B PRA 1:
Fecal Coliform

Class B PRA 2:

Class B PRA 3:
Measure the geometric mean of 7 samples at the time the sewage sludge is used or disposed.


Monitor at sufficient frequency to show that the  PSRP requirements are met.

Monitor at sufficient frequency to show that the  equivalent PSRP requirements are met.
                                                 Vector Attraction Reduction
Vector Attraction Reduction (VAR) 1:
38% Volatile Solids
Reduction (VSR)

VAR 2:
for Anaerobic Digestion:
Lab Test

VAR 3:
for Aerobic Digestion:
Lab Test

VAR 4:
SOUR Test for
Aerobic Processes
Once achieved, no further attractiveness to vectors. Follow Part 503 frequency of monitoring
requirements.
Once achieved, no further attractiveness to vectors. Follow Part 503 frequency of monitoring
requirements.
VAR 5:
Aerobic >40°C
Monitor at sufficient frequency to show that sewage sludge is achieving the necessary temperatures
over time.
VAR 6:a
Adding Alkali
Determine pH over time. Data are valid as long as the pH does not drop such that putrefaction
begins prior to land application.
                                                            148

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Table 13-1.   (continued)
VAR 7:a
Moisture Reduction
No Unstabilized
Primary Solids

VAR 8:a
Moisture Reduction
Primary Unstabilized
Solids

VAR 9:b
Injection into Soil

VAR 10b:
Incorporation into Soil

VAR 11b:
Covered with Soil
(Surface Disposal Only)

VAR 12b:
Domestic Septage
pH Adjustment
   To be achieved only by the removal of water. VAR 7 has been achieved as long as the moisture
   level remains below 30%.
   To be achieved only by the removal of water. VAR 8 has been achieved as long as the moisture
   level remains below 10%.
   No significant amount of sewage sludge remains on soil surface within 1 hour after injection.


   Sewage sludge must be incorporated into soil within 6 hours after being placed on the soil surface.


   Surface disposed sewage sludge must be covered daily.
   Preparer must ensure that pH is 12 for more than 30 minutes for every container of domestic
   septage treated with alkali.
1 EPA is proposing that requirements for options 6, 7, and 8 be met at the time of use or disposal.
' Conditions for options 9-12 must be maintained at all times if one of these options is chosen to meet vector attraction reduction requirements.
13.2.2   Frequency of Monitoring

The  Part  503  regulation  establishes  minimum  fre-
quency of monitoring requirements for sewage sludge
that is land applied  based on the amount  of sewage
sludge applied at a site in  a year, as discussed in Chap-
ter 3 and shown in Table 3-15. The permitting authority
may require increased frequency of monitoring if certain
conditions  exist,  such as  if no previous sampling data
are available on the  sewage sludge to be land  applied
or if pollutant concentrations or pathogen densities vary

Table 13-2.  Sampling Points for Sewage Sludge
Sewage Sludge Type
                               significantly  between  measurements.  The  permitting
                               authority also may reduce the frequency of monitoring to
                               a minimum of once annually if certain conditions exist (i.e.,
                               after two years, the variability of pollutant concentrations
                               or pathogen density is low and compliance is demonstrated).

                               Permitting requirements regarding frequency of monitor-
                               ing may differ depending  on whether sewage sludge is
                               continuously land applied or is stored prior to land ap-
                               plication, to ensure collection of a representative sample
                               of the sewage sludge that is actually land applied.
                                     Sampling Point
Anaerobically Digested

Aerobically Digested
Thickened

Heat Treated
Dewatered, Dried, Composted


Dewatered by Belt Filter Press,
Centrifuge, Vacuum Filter Press

Dewatered by Sewage Sludge
Press, (plate and frame)

Dewatered by Drying Beds
Compost Piles
Collect sample from taps on the discharge side of positive displacement pumps.
Collect sample from taps on discharge lines from pumps. If batch digestion is used, collect sample
directly from the digester. Cautions:
1. If biosolids are aerated during sampling,  air entrains in the sample. Volatile organic compounds may
be purged with escaping air.
2. When aeration is shut off, solids may settle rapidly in well-digested sewage sludge.

Collect sample from taps on the discharge side of positive displacement pumps.
Collect sample from taps on the discharge side of positive displacement pumps after decanting. Be
careful when sampling heat-treated sewage sludge because of:
1. High tendency for solids separation.
2. High temperature of sample (temperature < 60°C as sampled) can cause problems with certain
sample containers due to cooling and subsequent contraction of entrained gases.

Collect sample from material collection conveyors and bulk containers. Collect sample from many
locations within the sewage sludge mass and at various depths.

Collect sample from sewage sludge discharge chute.


Collect sample from the  storage bin; select  four points within the storage  bin, collect equal amount of
sample from each point  and combine.

Divide bed into quarters, grab equal amounts of sample from the center of each quarter and combine  to
form a composite sample of the total bed. Each composite sample should include the entire depth of
the sewage sludge material (down to the sand).

Collect sample directly from front-end loader while sewage sludge is being transported or stockpiled
within  a few days of use.
                                                         149

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13.2.3  Sample Collection

Liquid sewage sludge from pipelines should be sampled
as far downstream as possible to take advantage of
maximum mixing, thus reflecting the most representative
sample of sewage sludge to  be  land applied. If liquid
sewage sludge must be sampled from a lagoon, floating,
suspended, and sediment layers should be included in
the sample.

For dewatered sewage sludge (10%  to 40% solids),
sampling is best done when the sewage sludge is being
moved to  maximize representativeness. A convenient
way to collect samples might be to sample haul truck
loads at a  frequency that obtains the minimum number
of samples needed,  as required  by the frequency of
monitoring specified  in the  Part 503  regulation. This
frequency  can be determined by dividing the annual
tonnage or cubic yards of sewage sludge by the calcu-
lated number of samples to determine  how often haul
trucks or spreaders should be sampled. For example, if
250 cubic yards of sewage sludge are hauled to the site
annually in haul  trucks with a 25-cubic-yard capacity,
and if 10 samples are required, then one composite grab
sample from every truck  load might suffice, or several
samples from each truckload might be needed to obtain
a representative sample. If half that amount was hauled
in a year, then two composite grab samples representing
the front and back half of each truck would be needed.
If the amount of sewage sludge requires more truck
loads than samples, then samples would be taken of the
required percentage  of loads to obtain the requisite
number of samples.

Other EPA documents (U.S.  EPA, 1989,  1993, 1994)
provide more detailed guidance on specific procedures
for collecting sewage  sludge samples.

Sample collection and handling procedures should be
clearly defined and consistently followed to minimize
sample errors attributable to the sampling process. This
can be accomplished with a written sampling protocol
that includes:

• Specification of personnel responsible for collecting
  samples, and training requirements to ensure that the
  sampling protocol is correctly followed.

• Specification of safety  precautions to prevent expo-
  sure of sampling personnel to pathogenic organisms,
  such as use of gloves when  handling or sampling
  untreated or treated sewage sludge and cleaning of
  sampling equipment, containers, protective clothing,
  and hands  before delivering samples to others.

• Identification of the appropriate type of sampling de-
  vice. For liquid sewage sludge, certain types of plas-
  tic (e.g., polyethylene) or glass (e.g.,  non-etched
  Pyrex) may be appropriate, depending on the type of
  sample (e.g., metals or pathogens); coliwasas can be
  used  for sampling liquid sewage sludge from  la-
  goons. For dewatered sewage sludge, soil sampling
  devices, such as scoops, trier samplers,  augers, or
  probes can be used. If steel devices are used, stain-
  less steel materials are best; chrome-plated samplers
  should be avoided.

• Description of sample mixing and subsampling pro-
  cedures when grab samples of sludge are compo-
  sited and only part of the composite sample is used
  for analysis.  This usually requires use of a mixing
  bowl or bucket (stainless steel or Teflon) or a dispos-
  able  plastic sheet on which samples can be  mixed
  and from which  a smaller sample can be  taken.

• Specification of the size and material of sample con-
  tainers. Table 13-3 identifies suitable containers and
  minimum volume requirements  for sludge sampling.
  Sample containers can  often be obtained from the
  person or laboratory responsible for doing the sample
  analysis.

• Specification of sample preservation procedures and
  sample holding times. Table 13-3 identifies these  re-
  quirements for  sludge   samples. The appropriate
  regulatory agency,  in coordination with the  testing
  laboratory, should be contacted to  identify any  re-
  quired sample preservation  procedures and holding
  times for all constituents being monitored.

• Specification  of sample  equipment  cleaning proce-
  dures to ensure  that cross-contamination of samples
  does not occur. ASTM D5088 (Standard Practice  for
  Decontamination of Field Equipment Used at Nonra-
  dioactive Waste  Sites) provides guidance on these
  procedures.

• Specification of types  and frequency of quality assur-
  ance/quality control (QA/QC) samples. Again, the ap-
  propriate regulatory agency should  be  contacted to
  determine which types  of QA/QC samples may  be
  required for the  site.

• Description of sample chain-of-custody procedures to
  ensure that the  integrity of samples is maintained
  during transport and analysis of samples.

13.2.4   Analytical Methods

Table 13-4 identifies analytical methods for pathogens,
inorganic pollutants, and other sewage sludge parame-
ters that are required by the Part 503 regulation. Specific
methods for sewage sludge sample preparation and
analysis  for metals of interest are contained  in Test
Methods for Evaluating Solid Waste (U.S.  EPA,  1986).

13.3  Soil Monitoring  and Sampling

Soil sampling and analysis for constituents affecting
plant growth (see Chapter 6) may  be needed to ensure
                                                 150

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Table 13-3.  Sewage Sludge Sample Containers, Preservation, and Storage
Parameter
Wide-Mouthed
Container
Preservative3
Minimum
Maximum Storage Time3 Volumeb
Metals
Solid and semi-solid        P, G
samples
Cool, 4°C
                                                                                  24 hours
                                                                                                                    300ml
Mercury (liquid)
All other liquid metals
R G
P, G
HN03topH<2 28 days
HNO3 to pH < 2 6 months
500ml
1,000 ml
Pathogen Density and Vector Attraction Reduction
Pathogens
G, P, B, SS
1 . Cool in ice and water to <10°C 6 hours
if analysis delayed >1 hr, or (bacteria)
1 -4 liters0
Vector attraction
reduction
                                              2. Cool promptly to < 4°C, or
                                              3. Freeze and store samples to
                                              be analyzed for viruses at 0°Cd

                                              Variesb
                                    24 hours (bacteria and viruses)
                                    1 month (helminth ova)

                                    2 weeks
                                    Varies13
1 -4 liters0
a Preservatives should be added to sampling containers prior to actual sampling episodes. Storage times commence upon addition of sample
 to sampling container. Shipping  of preserved samples to the laboratory may be, but  is generally  not,  regulated under Department  of
 Transportation hazardous materials regulations.
b Varies with analytical method. Consult 40 CFR Part 503. For  dry sewage sludge, convert to dry weight (DW). DW = wet -=- percent solids.
c Reduced at the laboratory to approx. 300 ml samples.
d Do not freeze bacterial or helminth ova samples.
P  =   Plastic (polyethylene, polypropylene, Teflon)
G  =   Glass (non-etched Pyrex)
B  =   Presterilized bags (for dewatered or free-flowing biosolids)
SS =   Stainless steel (not steel- or zinc-coated)
Table 13-4.  Analytical Methods for Sewage Sludge Sampling3

Sample Type                                   Method
Enteric Viruses
Fecal Coliform
Helminth Ova
Inorganic Pollutants
Salmonella sp. Bacteria
Specific Oxygen Uptake Rate
Total, Fixed, and Volatile Solids
Percent Volatile Solids Reduction Calculation
ASTM Designation: D 4994-89, Standard Practice for Recovery of Viruses from
Wastewater Sludges, Annual Book of ASTM Standards: Section 11. Water and
Environmental Technology, ASTM, Philadelphia, PA, 1992.

Part 9221 E or Part 922 D, Standard Methods for the Examination of Water and
Wastewater, 18th edition, American Public Health Association, Washington, DC, 1992.

Yanko, W.A., Occurrence of Pathogens in Distribution and Marketing  Municipal Sludges,
EPA/600/1-87/014, 1987. PB 88-154273/AS, National Technical Information Service,
Springfield, VA; (800) 553-6847.

Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, EPA Publication
SW-846, 3rd edition (1986) with Revision I. 2nd edition. PB 87-120291, National
Technical Information Service, Springfield, VA.  3rd edition Doc. No. 955-001-00000-1,
Superintendent of Documents, Government Printing Office, Washington, DC.

Part 9260 D, Standard Methods for Examination of Water and Wastewater, 18th edition,
American Public Health Association, Washington, DC, 1992; or, Kenner, B.A. and H.P.
Clark, Detection and Enumeration of Salmonella and Pseudomonas aeruginosa, J.
Water Pollution Control Federation, 46(9):2163-2171, 1974.

Part 2710 B, Standard Methods for the Examination of Water and Wastewater, 18th
edition, American Public Health Association, Washington, DC,  1992.

Part 2540 G, Standard Methods for the Examination of Water and Wastewater, 18th
edition, American Public Health Association, Washington, DC,  1992.

Environmental Regulations and Technology—Control of Pathogens and Vectors in
Sewage  Sludge, EPA/625/R-92/013, U.S. Environmental  Protection Agency, Cincinnati,
OH, 1992; (614) 292-6717.
'All of these analytical methods are required by the Part 503 rule, except the Percent Volatile Solids Reduction Calculation, which is provided
 as guidance in the Part 503 rule.
                                                             151

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vigorous crop production. Soil monitoring  is not a Part
503 requirement. As discussed in Chapter 6, soil sam-
pling  at sewage  sludge  land  application  sites is per-
formed  primarily to assist in determining soil chemical
parameters (N, P,  and K) for calculation of sewage
sludge and supplemental fertilizer application rates to
supply  plant  nutrient  requirements. Additional  site-
specific analyses may be needed to  monitor the status
of some land application systems. For example, soils
may need to  be analyzed for soluble  salts  and/or boron
in semiarid regions where irrigation  is planned. Table
13-5 summarizes potential surface and subsurface soil
parameters that may be useful to monitor prior to or after
sewage sludge land application. Advice should be ob-
tained from the local University Cooperative Extension
Service, County Agricultural Agents,  and/or others with
expertise in sampling and analysis of soils in the sewage
sludge land application site area.

Table 13-5.   Potential Soil Surface Layer and Subsurface
           Parameters of Interest
       Monitoring Prior to Sewage Sludge Application
Surface Layer
Particle size distribution
PH
Electrical conductivity
Cation exchange capacity (CEC)
Lime requirement (acid soils)
Plant available P and K

Soil N parameters
 N03-N
 NH4-N
 Organic matter
 Organic-N
 C:N ratio
 Soil microbial biomass C and N
 N mineralization potential
Subsurface Layers
Particle size distribution
PH
Electrical conductivity
Cation exchange capacity (CEC)
        Monitoring After Sewage Sludge Application
PH
Electrical conductivity
Lime requirement (acid soils)
Plant available P and K

Soil N parameters
 Organic matter
 Organic-N
PH
Electrical conductivity
13.3.1   Sampling Location and Frequency

Initially,  soil samples can  be collected from each field
where sewage sludge will  be land applied. Generally, if
a given  field exceeds  10 ha (25  ac), individual  soil
samples should be collected from each soil series within
the field. The number and location of samples necessary
to adequately characterize soils prior to sewage sludge
land application is  primarily  a function of the spatial
variability of the soils at the site. If the soil types occur
in simple  patterns, a composite sample of each major
type can provide an accurate picture of the soil charac-
teristics. The site soil map described in Chapter 6 will
identify major soil types that should be sampled.

Soil pH measurements can be done in the field at relatively
low cost. Thus, measuring the pH of soil samples taken on
a grid pattern (e.g., 30 m [100 ft] sections), can serve as a
useful indicator of the degree of spatial variability within soil
map units. If pH is variable, drawing contours of equal pH
will  identify subareas in a soil  type where separate com-
posite samples  should be collected.  Such a map also is
useful when the pH of soil needs to be adjusted.

Once initial  sampling and analysis of soil  samples is
completed, the frequency of  subsequent sampling will
depend on land use and any state regulatory soil moni-
toring requirements. For agricultural crops, pH, P, and K
soil tests are typically done every two years. Monitoring
of these parameters typically is not required  for forest
land application sites. As discussed in Section  13.6.3,
monitoring requirements at reclamation sites will typically
be more extensive than at agricultural and forest sites.

If sewage sludge is applied at agronomic rates to supply
plant N requirements (as is required by Part 503), peri-
odic monitoring of soil-available N  may be useful be-
cause   of the  difficulty in   accurately  predicting  N
mineralization rates of sewage sludge. Annual monitor-
ing  of soil N  is appropriate for irrigated crops, as well as
certain non-irrigated crops such as  corn. Annual moni-
toring is less critical at  forest sites  because crops are
not removed each year, but may be performed initially
to gain an understanding of  nitrogen dynamics at the
site. Section  13.3.4 further discusses test methods for
estimating N  availability.

13.3.2  Number of Samples

In some states, the state regulatory agency stipulates
the minimum number  of soil borings which must be
analyzed. New  Jersey, for  example,  historically  has
based  the minimum number of soil  borings required
based  on the proposed sewage sludge land application
site area, ranging from a minimum of 3 borings on small
sites (up to  4 ha [10 ac]) to  24 borings on large sites
(over 80 ha [200 ac]. Samples taken from similar soil
horizons are  usually composited for several borings lo-
cated near each other in homogeneous soil. The com-
posited samples are subsequently analyzed.

13.3.3  Sample Collection

The proper selection of tools for collection of soil samples
depends in part on the texture  and consistency of the soil,
the  presence or absence of rock fragments, the depth to
                                                   152

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be sampled, and the degree of allowable soil surface
disturbance. Soil samples are most accurately taken
from a freshly dug pit. Where field plots are to be sam-
pled periodically, however, preferable sampling tools are
those which disturb  the plot  the least. Cutaway  soil
sampling  tubes, closed  cylinder augers,  and  tiling
spades (sharp-shooters) may be used depending on the
size of the plot and allowable disturbance. The cutaway
soil sampling tube  creates the least disturbance, and
works well in the plow layer and the upper subsoil of moist,
stone-free,  friable soils. Each  sample collected should
represent the cross section of the soil layer being sampled.

In sampling subsurface soils,  care must  be taken to
remove loose particles of sewage sludge residue on the
soil surface around the hole prior to and  during sam-
pling. In  addition, any  surface soil/sludge residue at-
tached to the top and side of the core samples from
lower depths should be removed by slicing with a knife.
Where cores  extend  below the depth of the seasonal
high water table, it is recommended that the holes be
sealed by filling with bentonite pellets and  tap water. A
map showing sample points should be made.

The depth to which the soil profile is sampled and  the
extent to which each horizon is vertically subdivided
depend largely on the parameters to be analyzed,  the
vertical variations in soil character,  and the objectives
of the soil sampling  program. For  initial charac-
terization, samples are typically taken from each dis-
tinct soil  horizon down to a depth of 120 to 150 cm (4
to 5 ft). For example, samples  may be taken from four
soil depths (horizons) as follows: 0 to 15 cm  (0 to 6 in),
15 to 45 cm (6 to 18  in), 45 to 75 cm (18 to 30 in), and
75 to 120  cm (30  to 42 in).  Usually,  at  a  minimum,
samples are taken from the upper soil layer (e.g., 0
to 15cm [Oto6 in]) and a deeper soil horizon (e.g., 45
to 75 cm [18 to 30 in]).

Subsequent samples for pH, P, and K monitoring  are
usually confined to the surface layer at 0-15 or 0-30  cm,
depending  on the thickness of the soil A horizon. Rec-
ommended sampling depths for developing NOs profiles
generally vary from 0.6 to 1.2 m, depending on the crop
and state. These variations are  based on depths known
to represent the best  correlation between soil-NO3 and
crop yield in particular areas and with particular crops.
Advice should be obtained from the local  University
Cooperative  Extension  Service, County  Agricultural
Agents,  and/or others with expertise in sampling and
analysis of soils in the locality of the sewage sludge land
application site  concerning  recommended sampling
depths for NO3 profiles. Depths up to 60 cm can usually
be collected by hand  without much difficulty. Collection
of samples exceeding 60  cm usually requires use of
power-driven soil sampling equipment.
Estimation of N immobilization (see Chapter 8) associ-
ated with initial sewage sludge application at forest sites
involves sampling of forest litter to measure the amount
of C and N. Representative samples of twigs, leaves,
and partially decomposed litter on the forest floor can be
collected and weighed to determine the total amount of
litter in kg/ha. It may also be desirable to quantify the
macroorganic fraction of the soil surface (the sand-sized
fraction  of  soil organic  matter). Gregorich  and  Ellert
(1993) discuss methods for measuring this fraction.

Soil samples  should be air-dried (at temperatures less
than 40°C), ground, and passed through a 2-mm sieve
as soon as  possible after collection. Chemical analyses
are generally performed on air-dried samples, which do
not require special preservation for most parameters.
Samples collected for nitrate, ammonia, and pathogen
analyses, however, should be refrigerated under moist
field conditions and analyzed as soon as possible.


13.3.4   Analytical Methods

Major reference sources for standard methods for physi-
cal and chemical analysis of soil samples include: Carter
(1993),  Council on  Soil Testing and  Analysis (1992),
Klute (1986), Page et al. (1982), Soil Conservation Serv-
ice (1984), and Westerman (1990).


13.3.4.1   Nitrogen

Keeney (1982) provides a  summary of soil analysis
methods used in different states to  develop N fertilizer
recommendations. The  most commonly used methods
are: (1)  NO3  profiles, and (2) measurement of soil or-
ganic matter content in the surface soil. NO3 profiles are
most commonly used in western states where crops are
grown under irrigation, but Sander et al. (1994) note that
the pre-sidedress  nitrate test (PSNT) has  been demon-
strated to be a useful test for corn crops in more humid
climates. Measurement of  organic matter content is
used  by a  number of states in both the eastern and
western United States to directly or indirectly estimate
mineralizable N. Missouri has refined the use of organic
matter by basing N mineralization rate estimates on soil
texture (Keeney, 1982).

Measurements of the mineralization potential of soils
and of soils amended with sewage sludge usually are
accomplished using  laboratory  soil column biological
incubation methods. Keeney (1982)  and Campbell et al.
(1993) describe these methods. Most of the references
identified at the beginning of this section cover the wide
variety of methods that are available for determination
of organic and inorganic forms of N  in soils.
                                                  153

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13.3.4.2   Plant-Available Phosphorus and
          Potassium

The amount of plant-available P is determined by ana-
lyzing the amount of P removed from soil by a particular
extractant. The extractant used varies in  different re-
gions of the  United States, but typically is  a dilute acid
or a bicarbonate solution. Essentially, all P taken up by
crops is present in insoluble forms in soils rather than
being in  the soil solution.  In all  states,  it  has been
determined that there  is a  relationship  between  the
amount of extractable P in a soil and the amount of P
fertilizer needed for various yields of different crops.
Such information may be obtained from extension serv-
ices or universities.

As with P, an extractant is used to determine the plant-
available K in a soil.  Potassium available for plant up-
take is present in the soil solution, and also is retained
as an  exchangeable cation on the cation  exchange
complex of the soil. The amount of plant-available K is
then  used to determine  the K fertilizer rate for the crop
grown. Most sewage sludge usually is deficient in K,
relative to crop needs.

13.4 Surface-Water and Ground-Water
      Monitoring

The  risk-based pollutant limits and the management
practices for land application specified  in the federal
Part 503  rule are designed to be sufficiently protective
of surface water and ground water so that  onsite water
quality monitoring usually is not required at land appli-
cation  sites. Some  states  may require surface or
ground-water monitoring for special conditions at a land
application site, as discussed below.

13.4.1   Surface- Water Monitoring

Properly designed sewage sludge land application sites are
generally  located, constructed, and operated to minimize
the chance of surface-water runoff containing  sewage
sludge constituents. Surface-water monitoring  rarely is
required when sewage  sludge is applied at agronomic
rates. In some cases, a state agency may require moni-
toring for special situations.  In these cases, the state
usually will specify monitoring locations and procedures.

13.4.2   Ground-Water Monitoring

Sewage sludge land application at agronomic rates should
pose no greater threat of NO§ contamination of ground
water than does the use of conventional  N fertilizers.
Special conditions at a land application site  may result in
ground-water monitoring requirements by the state. In
such cases, monitoring locations and procedures typically
will be specified by the appropriate state agency.
13.5 Vegetation Monitoring

The federal Part 503 pollutant limits and management
practices for land application specified in the Part 503
rule are designed to be sufficiently protective of vegeta-
tion regarding uptake of heavy metals so that onsite
monitoring  of vegetation is  not  required. Vegetation
monitoring may be conducted for public relations pur-
poses, when it is desirable to assure private crop or tree
farm owners  that their crops are not being adversely
affected by the use of sewage sludge. Table  13-6 sum-
marizes sampling procedures for field crops and  pas-
tures.

13.6 Monitoring and Sampling at
      Reclamation Sites

13.6.1   General

If a land application program at a reclamation site complies
with applicable requirements, the sewage sludge will pose
little potential for adverse  effects on the environment, and
no monitoring is necessary beyond the Part 503 frequency
of monitoring requirements (see Chapter 3). Some states
require monitoring at a reclamation site after the sewage
sludge has been land applied.  Special monitoring and
sampling procedures may be needed for such  monitoring
because  of more complex site geochemistry compared
to undisturbed soils.

13.6.2   Disturbed Soil Sampling Procedures

Standard soil sampling procedures employed on agri-
cultural fields can often  be used  for reclamation sites
that have had topsoil replaced. For some unreclaimed
sites, more intensive sampling may  be necessary to
characterize site conditions. In heterogenous materials,
such as mine  spoils, an adequate determination of con-
ditions may require sampling on  a grid pattern of ap-
proximately 30 m (100 ft) over the entire site.

Although the disturbed surface  materials often are not
soil in the generic sense, soil tests on disturbed lands
have proven useful. Soil tests on drastically disturbed
sites, however, do have some limitations that should be
taken into consideration  during site evaluation. Guide-
lines vary widely on the number of samples to betaken.
Recommendations for sampling  heterogeneous strip
mine spoils in the eastern U.S.  range from 4 to 25
individual samples per ha (1.5 to 10 per ac).  It has also
been suggested that one composite sample made up
of a minimum of 10 subsamples for each 4 ha (10 ac)
area may be adequate  (Barnhisel,  1975).  Many dis-
turbed lands are not heterogeneous, however, and the
range and distribution of characteristics of the surface
material often is more important than the average com-
position. In general,  it is recommended that material
that is visibly different in color or composition should
                                                 154

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Table 13-6.  Suggested Procedures for Sampling Diagnostic Tissue of Crops (Walsh and Beaton, 1973)


Crop                        Stage of Growth3                Plant Part Sampled
                                                                      Number
                                                                      Plants/Sample
Corn
Soybeans and other beans
Small grains
Seedling
Prior to tasseling
From tasseling to silking


Seedling
Prior to or during early flowering


Seedling
Prior to heading
Hay, pasture or forage grasses    Prior to seed emergence

Alfalfa, clover and other legumes  Prior to or at 1/10 bloom
Sorghum-milo

Cotton


Potato

Head crops (e.g., cabbage)

Tomato

Beans


Root crops

Celery

Leaf crops

Peas

Melons
Prior to or at heading

Prior to or at 1st bloom, or at 1st
square

Prior to or during early bloom

Prior to heading

Prior to or during early bloom stage

Seedling
Prior to or during initial flowering

Prior to root or bulb enlargement

Mid-growth (12-15 in. tall)

Mid-growth (12-15 in. tall)

Prior to or during initial flowering

Prior to fruit set
All the aboveground portion.                  20-30
Entire leaf fully developed below whorl.         15-25
Entire leaf at the ear node (or immediately       15-25
above or below).

All the aboveground portion.                  20-30
Two or three fully developed leaves at top of     20-30
plant.

All the aboveground portion.                  50-100
The 4 uppermost leaves.                     50-100

The 4 uppermost leaf blades.                 40-50

Mature leaf blades taken about 1/3 of the way    40-50
down the plant.

Second leaf from top of plant.                 15-25

Youngest fully mature leaves on main stem.      30-40


3rd to 6th leaf from growing tip.                20-30

1st mature leaves from center of whorl.         10-20

3rd or 4th leaf from growth tip.                10-20

All the aboveground portion.                  20-30
2 or 3 fully developed leaves at the top of plant.  20-30

Center mature leaves.                       20-30

Petiole of youngest mature leaf.                15-30

Youngest mature leaf.                       35-55

Leaves from 3rd node down from top of plant.    30-60

Mature leaves at base of plant on  main stem.    20-30
1 Seedling stage signifies plants less than 12 in. tall.
be sampled as separate units (areas) if large enough
to be treated separately in the reclamation program.

13.6.3  Suggested Monitoring Program

13.6.3.1    Background Sampling (Prior to Sewage
           Sludge Application)

Composite sewage sludge  samples  can be  collected
and analyzed to provide data for use in designing load-
ing rates. Composite soil samples can be collected from
the site  to determine pH,  liming  requirements,  CEC,
available nutrients,  and trace  metals  prior to sewage
sludge addition.

13.6.3.2    Sampling During Sewage Sludge
           Application

When the sewage sludge is delivered, grab samples can
be taken and analyzed  for moisture content if there is
variation in the moisture content of the sewage sludge.
Composite sewage sludge samples also should be col-
                             lected to assist in documenting the actual amounts of
                             nutrients applied  to the site (and trace metal amounts
                             applied, if Part 503 CPLR pollutant limits are being met,
                             see Chapter 3).

                             13.6.3.3   Post-Sewage Sludge Application
                                        Monitoring

                             Monitoring of the sewage sludge application site  after
                             the sewage sludge has been applied can vary from none
                             to extensive, depending on  state and local regulations
                             and site-specific conditions. Generally, it is desirable to
                             analyze the soil  after 1 year for soil pH changes. In
                             addition, periodic surface and ground water analysis
                             may be useful to document any long-term changes in
                             water quality.

                             Some states have very specific requirements for moni-
                             toring, and the designer should consult the appropriate
                             regulatory agency. Monitoring requirements by the State
                             of Pennsylvania (Pennsylvania Department of Environ-
                             mental Resources, 1988) provide an example:
                                                      155

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    The Pennsylvania Department of Environmental
    Resources (DER) requires a ground-water
    monitoring system on mine land amended with
    sewage sludge. The system must consist of the
    following, at a minimum:  (1) at  least one
    monitoring well  at a  point hydraulically
    upgradient in the direction of increasing static
    head from the area in which sewage sludge has
    been applied; (2) at  least three  monitoring wells
    at points hydraulically downgradient in the
    direction of decreasing static head from the area
    treated with sewage sludge; and (3) in addition to
    the three wells, the DER may allow one or more
    springs for monitoring points if the springs are
    downgradient from the treated sewage sludge
    area. Surface water monitoring points may also
    be required by the DER if appropriate for the
    specific site.

    Ground-water samples must be  collected and
    analyzed at required frequencies for various
    parameters, including Kjeldahl nitrogen,
    ammonia-nitrogen, nitrate-nitrogen; certain metals,
    organics, and other water quality  indicators; and
    ground-water elevation in monitoring wells. The
    DER may also require soil-pore  water monitoring
    using lysimeters located in the unsaturated zone
    within 36 inches of the soil surface. Soil sampling
    for certain metals, pH, and phosphorus using
    DER procedures is required for  mine reclamation
    sites that may be used for agriculture. For crops
    grown for animal consumption, the DER may
    require a crop analysis,  usually for certain
    specified metals.

13.7  References

When an  NTIS number  is  cited  in a reference,  that
document is available from:
   National Technical Information Service
   5285 Port Royal Road
   Springfield, VA 22161
   703-487-4650
Barnhisel, R. 1975. Sampling surface-mined  coal spoils. Department
   of Agronomy Report AGR-41, University of Kentucky, Lexington, KY.
Campbell, C., B. Ellert, and Y. Jame. 1993.  Nitrogen mineralization
   potential in soils. In: Carter, M.R., ed. Soil sampling and methods
   of analysis. Lewis Publishers, Boca Raton, FL, pp. 341-349.
Carter, M., ed. 1993. Soil sampling and methods of analysis. Lewis
   Publishers, Boca Raton, FL.

Council on Soil Testing and Analysis.  1992. Reference methods for
   soil analysis. Georgia University Station, Athens, GA.

Gregorich, E. and B.  Ellert.  1993.  Light fraction and  macroorganic
   matter in  mineral soils. In: Carter, M., ed. Soil sampling and meth-
   ods of analysis. Lewis Publishers, Boca Raton, FL, pp. 397-407.

Keeney,  D.  1982. Nitrogen-availability indices. In:  Page, A.L., ed.
   Methods  of soil analysis,  part 2, 2nd ed.  American Society of
   Agronomy, Madison, Wl, pp.  711-733.

Klute, A., ed. 1986. Methods of soil analysis,  part 1: Physical and
   mineralogical methods, 2nd edition. Agronomy Monograph No. 9,
   American Society of Agronomy, Madison, Wl.

Page, A., R.  Miller, D.  Keeney, eds. 1982. Methods of soils analysis,
   part 2—Chemical and microbiological properties, 2nd edition. ASA
   Monograph 9, American Society of Agronomy, Madison, Wl.

Pennsylvania Department of Environmental Resources. 1988. Land
   application  of sewage sludge.  In:  Pennsylvania Code, Title 25,
   Chapter 275.

Sander,  D.,  D. Walthers, and K. Frank. 1994. Nitrogen testing for
   optimum  management. Journal  of Soil and Water Conservation
   49(2):46-52.

Soil Conservation Service (SCS). 1984. Procedures for collecting soil
   samples  and  methods of analysis for soil survey. Soil  Survey
   Investigations Report No. 1,  U.S. Government Printing Office.

U.S. EPA. 1994. A plain English  guide to the EPA Part 503 biosolids
   rule. EPA/832/R-93/003. Washington, DC.

U.S. EPA. 1993. Preparing sewage sludge for land application or
   surface disposal: A guide for preparers of sewage sludge on the
   monitoring, record keeping, and reporting requirements of the fed-
   eral standards for the use or  disposal of sewage sludge, 40 CFR
   Part 503. EPA/831/B-93/002a. Washington,  DC.

U.S. EPA. 1992. Environmental regulations and  technology: Control of
   pathogens and vector attraction in sewage sludge.  EPA/625/R-
   92/013. Washington, DC.

U.S. EPA. 1989. POTW sludge sampling and analysis guidance docu-
   ment. NTIS PB93227957. Washington, DC.

U.S. EPA. 1986. Test methods  for evaluating  solid waste,  3rd ed.
   EPA/530/SW-846 (NTIS PB88239223). Current edition and up-
   dates available on a subscription  basis from U.S.  Government
   Printing Office, Stock #955-001-00000-1.

Walsh, L. and J. Beaton, eds. 1973. Soil testing and plant analysis.
   Soil Science Society of America, Madison, Wl.

Westerman,  R., ed. 1990. Soil testing and plant analysis, 3rd edition.
   Soil Science Society of America, Madison, Wl.
                                                        156

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                                            Chapter 14
                                General Design Considerations
14.1  Introduction

This chapter provides guidance for designing the com-
ponents of a land application system, including:

• Sewage sludge transport systems
• Sewage sludge storage

• Land application  methods

• Site preparation

• Supporting facilities
The designer should take into consideration each com-
ponent's impact on overall  system efficiency, reliability,
and cost when selecting and designing each of these
individual components of a  land application system. For
example, the most economical sewage sludge transpor-
tation method may not result in the lowest overall system
cost because of associated high costs at the treatment
plant and/or land application site.

14.2  Transportation of Sewage Sludge

14.2.1  Transport Modes

Efficient transport of sewage sludge should be a key
design consideration. Potential modes of sewage  sludge
transportation include truck, pipeline, railroad, or various
combinations of these three  modes (Figure 14-1).

The method of transportation chosen and its costs de-
pend on a number of factors, including:
• Characteristics and quantity of the sewage sludge to
  be transported.

• Distance from the treatment works to the application
  site(s).

• Availability and proximity of the transportation mode(s)
  to both origin and destination (e.g., roads, proximity
  of railroad spurs).

• Degree  of flexibility  required in  the transportation
  method  chosen.

• Estimated useful  life of the land application site based
  on site  characteristics (e.g.,  topography, vegetative
  cover, soil type, area available).
• Environmental and public acceptance factors.

To minimize the danger of spills, liquid sewage sludge
should be transported in  closed tank systems. Stabi-
lized, dewatered sewage sludge can be transported in
open vessels, such as dump trucks and railroad gondo-
las  if equipped with  watertight seals and anti-splash
guards.

14.2.2  Vehicle Transport

14.2.2.1   Vehicle Types Available

Trucks are widely used for transporting both  liquid and
dewatered sewage sludge and are generally the most
flexible means of transportation. Terminal points and haul
routes can be readily changed with minimal cost. Trucks
can be used for hauling sewage sludge eitherto the final
application site(s) or to an intermediate transfer point
such as railroad yards. Access to sewage sludge within
a treatment plant is usually adequate for truck loading.

Many truck configurations are available, ranging from
standard tank and dump bodies to specialized equipment
for hauling and spreading sewage sludge. Depending on
the type of sewage sludge to be hauled, different types
of vehicles can be used, as described below.

Liquid Sewage Sludge

The following types of vehicles can be used to  haul liquid
sewage sludge (usually less than 10 percent solids, dry
weight):

• Farm tractor and tank wagon, such as those used for
  livestock manure. Normally used only for short hauls
  and  by small rural communities.

• Tank truck,  available in sizes from 2,000 to 24,000 L
  (500 to  6,000 gal).
  -  Tank  truck adapted for field application of sewage
     sludge in addition to  road hauling.
  -  Tank  truck used for road hauling to the land appli-
     cation site(s),  with sewage sludge  subsequently
     transferred to a field  application vehicle  or an irri-
     gation system. Such  tank trucks are often termed
     "nurse trucks."
                                                 157

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Figure 14-1.  Examples of sewage sludge transportation modes to land application sites.
Dewatered or Composted Sewage Sludge

The  following types of vehicles can be used to haul
dewatered  or composted sewage sludge (usually 20 to
60 percent  solids, dry weight):

• Dump truck, available in sizes from 6 to 23 m3 (8 to
  30 yd3).

• Hopper (bottom dump) truck, available in sizes from
  12 to 19  m3 (15 to 25 yd3).

• Either of the above types  of trucks can  be used  for
  hauling the sewage  sludge  to the land application
  site(s) and can also be  adapted to spread sewage
  sludge.

Figure 14-2 shows photographs of some of the types of
trucks listed above.

14.2.2.2  Vehicle Size and Number Required

To properly assess the size and  number of vehicles
needed for transporting sewage sludge from  the treat-
ment plant to the application site(s), the following factors
should be considered:
• Quantity of sewage sludge, both present and future.

• Type  of sewage sludge—liquid  or dewatered/com-
  posted.

• Distance from treatment  plant to application site(s)
  and travel time.

• Type and condition of roads to be traversed, including
  maximum axle load limits and bridge loading limits.

• Provisions for vehicle maintenance.

• Scheduling of sewage  sludge application. In many
  areas, significant seasonal variations exist (due to
  weather, cropping patterns, etc.) regarding the quan-
  tity of sewage sludge that can be applied. The trans-
  port system capacity should be designed to handle
  the maximum anticipated sewage sludge application
  period, taking into consideration any interim sewage
  sludge storage capacity available.

• Percent of time when the transport vehicles will  be in
  productive use. A study (U.S. EPA, 1977a) of trucks
  hauling sewage sludge at 24 small to medium size
Figure 14-2a.  A 6,500-gallon liquid sludge tank truck (courtesy
            of Brenner Tank Company).
Figure 14-2b.  A 3,300-gallon  liquid sludge tank truck  with
            2,000-gallon  pup  trailer (courtesy of  Brenner
            Tank Company).
                                                  158

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Figure 14-2c.  A 25-cubic-yard dewatered sludge  haul truck
            (courtesy of Converto Manufacturing Company).

  communities showed that trucks hauling liquid sewage
  sludge were in productive use an average of 48 percent
  of the  time (range of 7 to 90 percent) based on an
  8-hour day and 5-day week. Average use  for trucks
  hauling dewatered sewage sludge was reported at 29
  percent.

Tables 14-1  and 14-2 provide guidelines for estimating
the number of trucks needed for transporting  liquid and
dewatered sewage  sludge, respectively. While the ta-
bles provide a means for making preliminary comparisons,
they are only a starting point in the decisionmaking proc-
ess for a specific project. For example, the tables can
be used to quickly compare vehicle needs as  a function
of whether liquid sewage sludge at 5 percent solids or
an equivalent quantity of dewatered sewage  sludge at
25 percent solids will be transported. Assuming a liquid
sewage sludge quantity  of 57  million L/yr (15 Mgal/yr,
which corresponds to 58,000 metric tons/yr  or 64,000
Tons/yr) compared with an equivalent quantity of dewa-
tered sewage sludge of  11,470 m3/yr (15,000  yd3/yr,
which corresponds to 12,000 metric tons/yr  or 13,000
Tons/yr). Also assume a one-way distance of 32 km (20
mi) from the treatment  plant  to the application  site.
Tables 14-1  and 14-2 indicate  that for an  8 hr/day op-
eration, approximately six 9,450 L (2,500 gal) tank trucks
are necessary to transport the liquid sewage sludge, while
only one 11.5 m3 (15 yd3) truck is necessary to transport
the dewatered sewage sludge. The difference  in fuel
purchase would be 202,000 L/yr (53,500 gal/yr) for the
liquid sewage sludge versus 50,300 L/yr (13,300 gal/yr)
for the dewatered sewage sludge; driver time required
for  the  liquid sewage sludge  would be 15,500 hr/yr
versus 2,600 hr/yr for the dewatered sewage sludge.
The savings in transportation costs for dewatered sew-
age sludge versus liquid sewage sludge can then be
compared to the cost of dewatering the sewage sludge.

The reader should be aware that the above example is
highly simplified in  that it assumes that the sewage
sludge transport operation takes place 360 days a year,
allows an average of only 10  percent for  labor hours
beyond actual truck operating hours, provides for only 2
Figure 14-2d.  A 12-cubic-yard dewatered sludge spreader vehi-
            cle (courtesy of Ag-Chem Equipment Company).

hr/day for truck maintenance time, and gives no consid-
eration to effects of sewage sludge type on operating
costs at the application site(s).

14.2.2.3   Other Truck Hauling Considerations

The haul distance should be minimized to reduce costs,
travel time, and  the potential  for accidents on route to
the application site(s). Factors such as unfavorable topo-
graphic features, road  load limits, and population  pat-
terns may influence  routing  so that the shortest haul
distance may not be the most favorable.

Effective speed and travel time can be estimated from
the haul  distance, allowing for differences in speed for
various segments of the route and the anticipated traffic
conditions. Periods of heavy traffic should be avoided
from a safety standpoint, for efficiency of operation, and
for improved public acceptability.

The existing highway conditions must be considered in
the evaluation of truck transport.  Physical constraints,
such as weight, height, and speed limits,  may limit truck
transport and will influence vehicle and route selection.
Local traffic congestion and traffic controls will influence
routing and also should be considered in determining
the transport operation schedule. Public opinion on the
use of local roadways, particularly residential  streets,
may have a significant effect  on truck transport opera-
tions and routing.

Fuel availability and costs can have a profound impact
on the operation and economy of sewage sludge hauling
activities. Larger trucks tend  to be  more fuel efficient
than smaller ones. Also, short haul distances over flat
terrain will have  lower fuel  requirements than long haul
distances over hills.

Truck drivers  and mechanics  as  well as loading  and
unloading personnel  will be required for large sewage
sludge hauling operations. Small operations may com-
bine these roles  into  one  or two persons.  Manpower
requirements can  be determined from  the  operating
schedule.
                                                  159

-------

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Hauling Schedule

The operating schedule for sewage sludge hauling can
be simple or very complex. An  example of a simple
hauling operation would be a case where all the sewage
sludge generated each day is hauled to  a reclamation
site and discharged into a large capacity sewage sludge
storage facility. In such a simple case, the designer can
easily develop an operating schedule for sewage sludge
hauling  based on:

• Quantity of sewage sludge to be hauled.

• Average round-trip driving time required.

• Sewage sludge loading and unloading time required.
• Truck maintenance downtime.

• Estimated truck idle time and maintenance downtime.
• Haul truck capacity.

• Length of working shifts and number of laborers (e.g.,
  drivers).
• Safety factor for contingencies  (e.g., variations in
  sewage sludge quantity generated; impassible roads
  due to weather).

In contrast to  the  simple case described above, the
development of a  complex  sewage sludge hauling
schedule for an agricultural land application program
may involve many privately owned sites. Such  a  pro-
gram is complicated by the need to take into account the
following additional factors:

• The variation in distance (driving time) from the treat-
  ment  works  to the privately owned farms accepting
  the sewage sludge.

• Existence or absence of sewage sludge storage ca-
  pacity provided at the application sites.

• Weather, soil conditions, and  cropping patterns  that
  may significantly limit the number of days and loca-
  tions for sewage sludge application at  the sites.

An example of the  large variations in sewage sludge
hauling  schedules for a complex agricultural land appli-
cation program is shown in Table 14-3, which indicates
the projected monthly sewage sludge distribution  for the
Madison,  Wisconsin,  "Metrogro" project. Table 14-3
shows that  projected  utilization  is  highest during the
spring,  summer, and fall months (e.g.,  April through
October), whereas sludge is not  applied  during any of
the winter months (December through March). The de-
signer should provide for the necessary sewage sludge
transport,  application, equipment, and labor to handle
the maximum sewage sludge distribution months. This
heavy scheduling, however,  then  results in underutiliza-
tion of equipment during the  low demand distribution
months, as  well as the  potential  problem  of shifting
employees to other productive work. Some municipali-
Table 14-3.  Projected Monthly Sludge Distribution for
          Agricultural Sludge Utilization Program, Madison,
          Wisconsin (Taylor, 1994)
Month
January
February
March
April
May
June
July
August
September
October
November
December
% of Annual
0
0
0
10.2
19.7
5.2
5.9
14.1
17.2
18.6
9.1
0
Gal/Month
(x 1000)
0
0
0
2,950
5,700
1,500
1,700
4,100
5,000
5,400
2,650
0
Gal/Day*
0
0
0
147,600
285,000
75,000
85,000
205,000
250,000
270,000
132,000
0
*Based on 20-day/month operation
Metric conversion: 1 gal = 3.78 L
ties have  supplemented  their basic needs  with private
haulers during peak periods to help overcome this problem.

Contract Hauling Considerations

Many municipalities,  both large and small,  use private
contractors for hauling sewage sludge and sometimes
for application of sewage sludge as well. For example,
a contract operator transports, applies, and incorporates
dewatered sewage sludge from the Atlantic Wastewater
Treatment Plant in Virginia Beach, Virginia, to privately
owned farmland.  Incorporation is handled by the con-
tractor because the farmers were not incorporating the
sewage sludge promptly (Jacobs et al., 1993).

The economic feasibility of private contract hauling ver-
sus use of publicly owned vehicles and public employ-
ees should  be  analyzed for most new projects.  If a
private contractor is used, it is essential that a compre-
hensive contract be prepared that includes a total man-
agement  plan  and  avoids  municipality  liability  for
mistakes made by the contractor. At a minimum, the
contract should cover the following responsibilities:

• Liability and insurance for equipment and  employees.

• Safety and public  health protection  procedures and
  requirements.

• Estimated sewage sludge  quantities  and handling
  procedures.

• Responsibility and  methods for handling citizen com-
  plaints and other public relations.

• Procedures for  accidents,  spills, and violation notifi-
  cation and mitigation.
                                                  162

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• Monitoring procedures, record keeping, and reporting
  requirements (see Chapter 13 for monitoring  needs
  and Chapter 15 for recordkeeping and reporting re-
  quired by the Part 503 regulation).

• Responsibility for obtaining and maintaining permits,
  licenses, and regulatory agency approvals.

• Standard legal provisions for non-performance relief,
  termination,  etc.

In some instances, sewage sludge is hauled away from
the treatment works or other facility generating or pre-
paring sewage sludge  by the user (e.g., farmer, com-
mercial  forest  grower). Again, the  municipality should
obtain competent  legal council to avoid potential liability
due to negligence by the private user/hauler.

Additional Facilities Required for Hauling

Sewage sludge loading facilities at the  treatment works
or other sewage sludge facility should be placed in an
accessible location. Depending  on the type of sewage
sludge being hauled, hoppers, conveyor belts, or pipe-
lines will be needed to  load the  trucks. Vehicle storage
and a maintenance/repair shop might  be useful at the
plant site. Equipment washdown facilities and parking
should be nearby. Similar facilities for truck unloading
and related activities may be necessary at the sewage
sludge application site(s) and/or the  sewage  sludge
storage  facility.

14.2.3   Pipeline Transport

Generally, only liquid sewage sludge of 8 percent solids
or less can be transported by pipeline (U.S. EPA, 1978).
Sewage sludge with higher solids concentrations, how-
ever, have been pumped; for example, the city of Seat-
tle, Washington has reportedly pumped sewage sludge
containing up to 18 percent solids. Also, pipeline trans-
port is not usually feasible if there are multiple,  widely
separated land application sites. Other important factors
regarding pipeline transport include:

• Availability of land for sewage sludge application for
  projected long-term periods; if an application site has
  a short useful  life, pipelines are not  usually war-
  ranted.

• Sufficient sewage  sludge  volume to justify the  high
  capital costs of a pipeline, pump station(s), and ap-
  purtenances. Generally, municipal sewage treatment
  plants  sized below 19 million L/day (5 mgd) do not
  generate sufficient sewage sludge  volume to justify
  pipeline transport unless the distance to the land ap-
  plication site is  short, e.g., less than 3 km (2 mi).

• Existence of a  relatively undeveloped and flat pipe-
  line right-of-way alignment between the sewage treat-
  ment plant and the land application site. Constructing
  a new pipeline through developed  residential/com-
  mercial areas or through hilly terrain is expensive.

If factors such as those  listed above are favorable,
transport of sewage sludge by pipeline often can be less
expensive than truck transport per unit volume of sew-
age sludge.

14.2.3.1   Pipeline Design

The effect of solids concentration on sewage sludge flow
characteristics is  of  fundamental importance  in  eco-
nomically designing pipelines. Digested sewage sludge
has been observed to exhibit both newtonian and plastic
flow characteristics. Figure 14-3 shows the influence of
sludge solids concentrations on minimum velocities re-
quired for full turbulent flow  through  a  pipeline.  The
figure also indicates the frictional head  loss and the
range of velocities for economical transportation. Below
approximately 5  percent solids, sewage sludge  flow
exhibits newtonian flow characteristics, whereas at con-
centrations above 5 percent, the flow begins to exhibit
plastic flow characteristics. At a solids  concentration
below 5 percent, the economics of sewage sludge trans-
port will resemble water transport costs with respect to
frictional head loss and power requirements. The most
cost-effective pipeline design usually assumes opera-
tion just within the upper limits for newtonian flow (ap-
proximately 5.5 percent solids) (Haug et al., 1977). An
extensive discussion  of head  loss  calculations  and
equations for sewage sludge pipelines and pumping can
be found in Chapter 14 of the Process Design Manual
for Sludge Treatment and Disposal (U.S.  EPA, 1979).

Various pipeline materials are used fortransporting sew-
age sludge, including steel, cast iron, concrete,  fiber-
glass,  and  PVC. For long-distance,  high-pressure
sewage sludge pipelines, steel pipe is most commonly
used. Corrosion can be a severe problem unless  prop-
erly considered during design. External  corrosion is a
function of the pipe material and corrosion potential of
the soil,  and  can be  controlled by a suitable coating
and/or cathodic   protection system.  Laboratory  tests
simulating several digested sewage sludge lines have
indicated that with proper design, only moderate internal
corrosion rates should  be expected in  long-distance
pipelines conveying sewage sludge. If most of the grit
and other abrasive materials are removed from the di-
gested sewage sludge, wear due to friction  is not a
significant factor in pipeline design (U.S.  EPA, 1979).

14.2.3.2   Pipeline Appurtenance Design

Commonly used sewage sludge pipeline appurtenances
are discussed briefly  below. More  extensive discussion
can be found in Chapter 14 of the Process Design Manual
for Sludge Treatment and Disposal (U.S. EPA, 1979).
                                                  163

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                         10.0
                     111
                     111
                     u_
                     o
                     o
                     I-
                     UJ
                     111
                     LL
                     
                     o
                     UJ
                     I
                     z
                     o
                                  LEGEND
                                  MINIMUM VELOCITY FULLY
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                                  INCREASING
                                                                                10.0
                                         VELOCITY FEET/SECOND
                                            METRIC CONVERSIONS!

                                                    ONE FT/S£C.  = 0.3043 m/SEC.
Figure 14-3.  Hydraulic characteristics of sludge solids (U.S. EPA, 1977b).
Gauges

Pressure gauges are installed on the discharge side of
all pumps. They also may be installed  on the  suction
side of pumps for purposes of head determination. Pro-
tected,  chemical-type gauges are  generally used for
sewage sludge pumping.

Sampling Provisions

Generally, 2.5 to 3.8  cm (1 to 1-1/2 in) sampling cocks
with plug  valves are provided either on the sewage
sludge pump itself or in the pipe adjacent to the pump.

Cleanouts and Drains

Sewage sludge pipelines  should  include  separate
cleanouts and drains  for easy clearance of obstructions.
Blind flanges and cleanouts  should be  provided at all
changes of  direction of 45 degrees or  more.  Valved
drains should be included at all low points in the pipeline,
and pressure vacuum relief valves  should be provided
at all high  points  in the  pipeline. Minimum size at
cleanouts  is  10  cm  (4 in),  with  a 15 cm (6 in) size
preferred for access of tools.
Hose Gates

A liberal number of hose gates should be installed in the
piping, and an ample supply of flushing water under high
pressure should be available for clearing stoppages.

Measuring Sewage Sludge  Quantities

Pump running time totalizers provide a simple method
of approximating the  quantities  of sewage  sludge
pumped. For more sophisticated measurement, Venturi
meters, flow tubes,  or magnetic meters with flushing
provisions can be used. Sewage sludge meters should
have provision for bypassing.

14.2.3.3   Pump Station Design

Pump stations  used to pump sewage sludge through
long-distance pipelines should be carefully designed by
experienced engineers. This  section is not intended to
be a comprehensive guide to design of such stations,
but rather highlights  important  design considerations
and provides references for more extensive information.
Important factors  for designing  long-distance sewage
sludge pumping stations include:
                                                  164

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• Characteristics of the sewage sludge (e.g., type, sol-
  ids content, degree of stabilization, abrasive particle
  content, viscosity).

• The choice of variable versus constant speed pumps.

• Quantity of sewage sludge, and type and capacity of
  sewage sludge  storage ahead of the pumps and at
  the pipeline terminus.

• Pressure that the pumps must overcome,  including
  both  pipeline friction loss and static (elevation differ-
  ence) head.

• Anticipated pump station life.

• Need for future expansion of capacity (e.g.,  provision
  of space for future pumps, power supply, piping, etc.).

• Ease of operation and maintenance.

• Need for standby reliability (i.e., how long the pump
  station can be out of service for maintenance, power
  failure, etc., as  determined by available storage, al-
  ternate means of transport, etc.).

The  type of sewage sludge most easily  pumped over
long distances has the following characteristics: a solids
content below 6 percent; good stabilization (i.e., rela-
tively low in volatile solids); a low concentration of abra-
sive  grit; and the absence of large particles and stringy
material. Sewage  sludge possessing  other  charac-
teristics can be dealt with during design, but will normally
result in increased construction, operation, and/or main-
tenance costs.  In Arizona, a  high-speed centrifugal
pump is used to force  dewatered sewage sludge  (20
percent solids) and water into a pipe delivering the solids
to the field. The sewage sludge is then reliquified to a
solids content of 4 percent. The solids content of the
sludge  at this Arizona site can be adjusted by regulating
the amount of water injected into the pump. The sewage
sludge  is then pumped to the application site through a
system of fixed and movable pipes (Jacobs et al., 1993).

Maximum and minimum flow velocities are an important
consideration in pipeline design. A comparison of vari-
able versus constant speed pumps is important for de-
termining the flow through a pipeline. Variable speed
pumps allow for continuous operation and lower storage
requirements. Although  constant speed  pumping  will
require more storage, it is usually more energy efficient
for peak flow dampening by equalization. For sewage
sludge  transport, a flow rate of 1 m/s (3 ft/s) is a satis-
factory value; slower rates can promote solids settling
and decomposition, while higher rates can cause scour-
ing and increase head loss. Since pipelines represent a
significant investment and have long  service lives, they
should  be sized to permit efficient operation under ex-
isting conditions and also provide adequate capacity for
future growth.
The  quantity  of sewage sludge to be pumped deter-
mines the capacity of the pumps and the pump station.
Capacity is measured by the maximum sewage sludge
pumping rate required; therefore, it is desirable to pro-
vide  as constant an output pumping rate as possible
over long periods each day. Ideally, the pumps will with-
draw the sewage  sludge from a large volume storage
facility  (e.g., a digester) at  a steady rate.  If possible,
avoid using small storage tanks that require the pumps
to frequently start and stop. The storage facility supply-
ing the pump with sewage sludge should have a liquid
level higher than  the elevation of the  pump suction
intake.  Sewage sludge pumps work much  more effi-
ciently  and reliably if they have a positive suction head.

The  pressure that sewage  sludge  pumps  must over-
come is the  elevation  difference  between  the pump
station  and the highest point of the sewage  sludge
pipeline to the application site; also, friction loss exists
in the pipe and fittings at the maximum sewage sludge
pumping rate (when maximum pressure occurs). The
elevation difference (static head) is fixed by the topog-
raphy of the pipeline alignment. The head loss due to
friction,  however, will vary and can be expected to in-
crease with  time  due to gradual  deterioration of the
pipeline, buildup of internal  sewage  sludge  deposits,
and other factors.  The designer, therefore, should pro-
vide  a safety factor in calculating total pressure loss due
to friction in the pipe and fittings. An excellent discussion
of sewage sludge pipeline  head loss due to friction is
found in Chapter 14 of the  Process Design Manual for
Sludge Treatment and Disposal (U.S. EPA, 1979).

Type and Number of Pumps

Various types of  pumps are used to  pump sewage
sludge,  including  centrifugal, torque, plunger,  piston,
piston/hydraulic diaphragm, ejector, and air lift pumps.
Table 14-4 presents  a  matrix that provides guidance
regarding the suitability of each type of pump for  han-
dling different types of sewage  sludge.  Centrifugal
pumps are commonly selected for long-distance sew-
age  sludge pumping because they are more efficient
(i.e.,  use less energy) and can develop  high discharge
pressures. Centrifugal pumps are generally not used for
heavy,  primary sewage sludge, however, because they
cannot handle large or fibrous solids. See Chapter 14 in
the Process Design Manual for Sludge  Treatment and
Disposal (U.S. EPA, 1979) for a more detailed descrip-
tion of pump types.

The  number of pumps installed in a pump station will
depend largely on the station capacity and the range in
sewage sludge volumes to be pumped.  It is customary
to provide a total pumping  capacity equal to the maxi-
mum expected inflow with at least one of the pumping
units out of service. In stations handling small flows, two
pumps are usually installed, with each pump capable of
                                                  165

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166

-------
meeting the maximum inflow rate.  For larger stations,
the size and number of pumps should be selected so
that the range of inflow can be met without starting and
stopping pumps too frequently (Water Pollution Control
Federation, 1981).

Unless the designer is certain that future pump station
expansion will not be  necessary, space, fittings, etc.,
should be provided  in  the pump station for future addi-
tional pumping capacity.

The design should  assume that the pump station will
occasionally be inoperative due to maintenance,  power
failure, etc. Sufficient  storage capacity should be pro-
vided for sewage sludge, and/or standby power, to han-
dle at least two days of  pumping station shutdown.
Emergency tank truck  hauling by a private firm  is one
alternative that could be arranged in advance.

14.2.3.4   Decisionmaking Factors for Pipeline
          Transport

Major factors to consider in an initial evaluation of sew-
age sludge pipeline transport include:

• Lack of flexibility compared to truck transport. The
  pipeline has a fixed alignment and terminus. The land
  application site must have  a sufficient useful  life to
  justify the capital  expense of the pipeline and pump
  static n(s).

• Sufficient sewage sludge volume generation to justify
  the initial capital cost. If one or two tank trucks can
  do the job instead, truck transport will often be more
  cost-effective.

• Need to acquire  pipeline right-of-way. Pipeline align-
  ments  that avoid right-of-way easement  problems
  should be evaluated. Condemnation,  when  neces-
  sary,  is  expensive  and time-consuming  and may
  cause problems with community acceptance.

If pipeline transport is selected, the following  factors
should be considered when choosing pipeline routes.

Alternate Routes

Preliminary planning should be conducted to reduce the
number of potential pipeline routes. Generally,  one route
will be clearly favorable over the others;  however, due
to unknown conditions, a  certain amount of flexibility
should be  maintained  until the final design  is  deter-
mined. Crossings can add significantly to the cost of the
pipeline and complexity of construction. The shortest
distance with the least elevation difference and fewest
crossings should be the primary goal.

Pipeline Design

Pipeline friction losses should be minimized over the
route of the pipeline since they contribute significantly to
pumping requirements. Abrupt changes in slope and
direction should be minimized. Depending on the nature
of the sewage sludge and the characteristics of the soil,
corrosion control features should be incorporated in the
pipeline design. Frequently spaced isolation  valves
should be provided to allow shutdown during repair and
in case of pipe failure.

Pumping Facilities

More than one  pump  station  may  be needed if the
pipeline distance is long. The number of pump stations
should be balanced with the size and number of pumps
required to determine the most cost-effective combina-
tion. Pumps should be appropriate for the type  of sew-
age sludge to be pumped, and standby pumping units
must be provided.

Emergency Operation

Several days storage should be provided in case of
equipment failure. Digesters can be used for this pur-
pose, if available. Standby power should be provided if
only one independent source of electricity to the pump
stations is available. Additional storage  may be substi-
tuted for standby power  under certain conditions,  al-
though continuous operation is preferable.

Excavation Condition Verification

Field  tests should  be used to establish or  verify the
subsurface soil conditions. Borings should be taken  af-
ter the pipeline route has been established but prior to
final design. The field tests should be used  to isolate
areas where special design considerations are needed.
If highly unusual localized conditions exist, they should
be avoided, if possible, or additional field tests made.

Existing or planned underground utilities should be lo-
cated and  field-verified, if possible.  If exact locations
cannot be  established, the contractor should be held
responsible for locating them during construction.

Acquisition of Right-of-Way

Right-of-way easements must be acquired for pipelines
on private property. This process should be initiated in
the early stages of the  project. The preferable  method
is to obtain access rights on easements owned  or con-
trolled by  other utilities when  possible,  or to negotiate
with landowners. Acquisition is a lengthy, complex pro-
cedure which should be avoided if possible.

14.2.4  Other Transport Methods

Rail car and barge transport are other possible methods
for  transporting  sewage  sludge. These methods are
usually considered  only by large cities for long-distance
transport to land application sites. In Chicago, for exam-
ple, sewage sludge has been dried to over 50  percent
solids, barged,  and then  trucked to land application
sites (Jacobs et al., 1993). For a detailed discussion of
                                                  167

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rail and barge  transport, refer to Chapter  14 in  the
Process Design Manual for Sludge Treatment and Dis-
posal (U.S. EPA, 1979).

14.3 Storage of Sewage Sludge

It is important to note that in the Part 503 regulation, an
activity is considered storage if sewage sludge is placed
on land for 2 years or less. If sewage sludge remains on
land for longer than 2 years for final disposal, this land
area is considered an active sewage sludge unit and the
surface disposal requirements in Part 503 must be met,
unless the sewage sludge preparer can demonstrate
that the land on which the sewage sludge remains is not
an active  sewage  sludge unit,  as  discussed in  Part
503.20(b).

14.3.1  Storage Requirements

Sewage sludge storage is necessary to accommodate
fluctuations in sewage sludge production rates, break-
downs in equipment, agricultural cropping patterns, and
adverse weather conditions which prevent immediate
application of sewage  sludge to the land.  Storage can
potentially be provided at either the treatment plant, the
land application site(s), or both. Chapter 15 in the Proc-
ess Design Manual for Sludge Treatment and Disposal
(U.S. EPA, 1979) presents methods for estimating sew-
age sludge storage capacity and describes various stor-
age facilities.

14.3.2  Storage Capacity

Storage capacity associated with  land application sites
is based on the volume and characteristics of the sew-
age  sludge and on climate considerations. In a 1993
study of 10 POTWs, most had extensive sewage sludge
storage capacities or other systems in place (Jacobs et
al., 1993).  Forexample, a facility in Madison, Wisconsin,
has  a large storage lagoon system that will soon be
replaced with new storage tanks capable of storing 6
months (18 million gallons) of sewage sludge. In Denver,
Colorado,  the Metro Wastewater Reclamation District
(MWRD)  currently composts about 10 percent of the
sewage sludge  it produces; while composting  is more
expensive than direct land application, the MWRD main-
tains the composting facilities to enhance the flexibility
and reliability of the land application program (Jacobs et
al., 1993).

Many states have regulations  governing the provision of
storage capacity for sewage sludge at land application
sites, with requirements  varying from state  to state.
Indiana, for example, requires storage with a minimum
of 90-days capacity at land application sites; Michigan
requires that field storage be less than 7 days unless the
stored sludge is covered and a seepage barrier is pro-
vided; in Oklahoma, storage at a land application site is
not permitted (U.S. EPA, 1990).
14.3.2.1   Effect of Sewage Sludge Volume and
          Characteristics on Storage Capacity

Storage capacity is primarily dependent on the amount
of sewage sludge needed at the land  application site
and the volume of sludge received from the treatment
works. Storage capacity should be large enough to han-
dle the volume of sludge generated during the longest
projected time interval between applications (Elliott et
al., 1990) and may need to be larger depending on
climatic factors (see below).  For agricultural systems,
the time period between applications can range from 3
months to a year, whereas time spans between applica-
tions to  forest land may be greater than 1 year (Elliott
etal., 1990).

The characteristics of sewage sludge also affect storage
(e.g., liquid sludge might be stored in tanks, while sludge
solids may  be stockpiled).  Sewage  sludge  charac-
teristics vary with source, type of sewage sludge treat-
ment, and retention time. Data on typical quantities and
characteristics of sewage sludge produced from various
treatment processes are presented in Chapter 4.

14.3.2.2   Climate Considerations for Evaluating
         Sewage Sludge Storage

The designer of a land application system should con-
sider the following climatic factors:

• Historical precipitation and temperature records for
  the application site.

• Regulatory agency requirements pertinent to the land
  application  of sewage sludge on frozen, snow-cov-
  ered,  and/or wet soil.

• Ability of the sewage sludge  application equipment
  being used to operate on wet or frozen soil.

• Drainage characteristics of the application site and
  associated  effects on the time required after precipi-
  tation for the soil to dry sufficiently to accommodate
  equipment.

If left  uncovered, large volumes of sludge may be ex-
posed to the elements during  storage (Elliott et al.,
1990). Therefore, precipitation volume (minus evapora-
tion) must be added to the storage area  required for
sewage sludge. In addition, the Part 503 rule sets re-
strictions on  the land application of certain types of
sewage sludge to flooded, frozen, or snow-covered
lands (see Chapter 3). Many states also have seasonal
limits  on land application of sewage  sludge, which
greatly influence storage requirements at land application
sites. These limits generally forbid the application of sew-
age sludge to saturated ground, ice- or snow-covered
ground, or during rainfall (U.S. EPA, 1990).

The effect on wet soils of heavy vehicle  traffic transport-
ing sludge from storage to application areas also should
                                                  168

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be considered. The weight of vehicles may damage the
soil structure,  increase the  bulk density of soil, and
decrease  infiltration.  These  changes  in the physical
characteristics of soil  may increase the potential for soil
erosion and surface runoff (Lue-Hing et al., 1992).
The climatic considerations that affect sewage  sludge
storage capacity are  greatly influenced by site-specific
factors. A review of land application system designs in
the United States indicates that sewage sludge storage
capacity ranges from a minimum of 30 days in hot, dry
climates up to 200 days in cold, wet climates.
EPA conducted a  computer analysis  of approximate
storage requirements forwastewater-to-land application
systems  in the United States (Loehr et  al., 1979), as
shown in  Figure 14-4. This information is included in this
manual to show general regional variations in storage
requirements due to  climate. For most sewage sludge
land  application systems, the  actual storage  require-
ment will  usually exceed the days shown in Figure 14-4.
 BASED ON 0 *C (32 *F)
 MEAN TEMPERATURE
 1.25 CIB/d PRECIPITATION
 2.5 cm OF SNOWCOVER
SHADING DENOTES REGIONS WHERE
THE PRINCIPAL CLIMATIC CONSTRAINT
TO APPLICATION OF WASTEWATER
IS PROLONGED WET SPELLS
Figure 14-4.  Storage days required as estimated from the use
           of the EPA-1 computer program for wastewater-to-
           land systems. Estimated storage based  only on
           climatic factors.
14.3.2.3   Relationship Between Scheduling and
          Storage

The majority of existing land application systems in the
United States are applying sewage sludge to privately
owned land. This requires a flexible schedule to conform
with local farming practices. Scheduling limitations will
result from cropping patterns, and typically the designer
will find that  much of the agricultural land  can only
receive sewage sludge during a few months of the year.
Applications of sewage sludge should be scheduled to
accommodate the growing season of the selected plant
species (Lue-Hing et al., 1992). The Madison, Wiscon-
sin, program (Table 14-3), for example, applies over 80
percent of  its sewage sludge to farmland during  the
                             6-month  period  from May through  October (Taylor,
                             1994).

                             Land application to forest sites should be scheduled to
                             conform with tree  grower operations and  the annual
                             growth-dormant cycle of the tree species. Land applica-
                             tion at reclamation  sites must be scheduled to conform
                             with vegetative seeding and growth patterns and also
                             with private landowners' operational schedules. At all of
                             these types of sites, adequate storage capacity must be
                             provided to accommodate the variability in scheduling.

                             14.3.2.4   Calculation of Sewage  Sludge Storage
                                       Capacity Required

                             A simple method for estimating sewage sludge storage
                             capacity  required  involves estimating  the  maximum
                             number of days needed to store the volume of sewage
                             sludge generated. The estimate of the maximum num-
                             ber of days is based on climate and scheduling consid-
                             erations discussed  in the previous subsections, as well
                             as a  safety factor. Often, the responsible  regulatory
                             agency will stipulate the minimum  number of days of
                             sewage sludge storage that must be provided. Calcula-
                             tions for this simple approach are shown below:

                             Assume:

                             1 . Average rate  of dry sewage sludge generated  by
                               POTW is 589  kg/day (1 ,300 Ib/day).

                             2. Average sewage sludge contains 5 percent solids.

                             3. One hundred days storage to be  provided.

                             Solution:
1 . 589 kg/day _ ^
      u .uo
  sewage sludge.
                                                                           kg/day (26 OOQ |b/day) of |iquid
                             2. 1 1 ,780 kg/day = 1 1 ,780 L/day (3,116 gal/day) of liquid
                                sewage sludge produced.

                             3.11 ,788 L/day x 1 00 days = 1 .2 million L (31 2,000 gal)
                                of storage required.

                             A more sophisticated  method for calculating  sewage
                             sludge storage requirements is to prepare a mass flow
                             diagram of cumulative generation and projected cumu-
                             lative application of sewage sludge to the land  applica-
                             tion site, as shown in Figure 14-5. The figure shows that
                             the minimum sewage sludge storage requirement for
                             this site is approximately 1.2 x 106 gal (4.54 x 106 L),
                             which represents  84 days of sewage  sludge  storage
                             volume. The project designer should increase the mini-
                             mum storage requirement by a safety factor of 20 to 50
                             percent to cover years with unusual weather and other
                             contingencies.

                             Even  more accurate approaches can be used to calcu-
                             late required sewage sludge storage volume. For exam-
                             ple, if open lagoons are used for sewage sludge storage,
                                                  169

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                                                        TOTAL ANNUAL SLUDGE
                                                        VOLUME GENERATED
                                           LINE A
                                           CUMMULATIVE SLUDGE
                                           VOLUME GENERATED 'X
                                           BYTHEPOTW
                              SLUDGE
                              STORAGE
                              VOLUME
                              REQUIRED
                              1.2X106GAL
                                                      LINE C, SAME SLOPE
                                                      AS LINE A, LOCATE
                                                      TANGENT TO LINE B
                         J    F    M    A
              LINEB
              CUMMULATIVE SLUDGE
              VOLUME APPLIED TO
              THE SLUDGE APPLICATION
              SITE (S)
                       METRIC CONVERSION
                          1 GAL = 3.78 LITERS
Figure 14-5.  Example of mass flow diagram using cumulative generation and cumulative sludge application to estimate storage
           requirement.
the designer can calculate volume additions resulting
from  precipitation and  volume  subtractions resulting
from evaporation  from the storage lagoon surface.
  Minimize  the  number of times  the  sewage sludge
  must be handled (e.g., transferred, stored) because
  costs are incurred each time handling occurs.
14.3.3  Location of Storage

In general, the following  factors should  be considered
when siting sewage sludge storage facilities:

• Maximize the use of potential storage in the existing
  sewage treatment plant units. If the treatment plant
  has  aerobic or anaerobic digestion tanks, it is often
  possible to  obtain several weeks storage capacity
  by separating  the digester(s)  to  increase solids
  content and sewage sludge storage. In addition, older
  POTWs often have phased-out tanks, sewage sludge
  drying  beds,  and other  areas that  are  idle  and
  could be used for sewage sludge storage if properly
  modified.

• If possible, locate long-term sewage  sludge storage
  facilities at the  POTW  site to take advantage of the
  proximity of operating personnel, ease of vandalism
  control, and  the possibility of sewage sludge volume
  reduction, which will reduce  transportation costs.
 14.3.4  Storage Design

Storage capacity can be provided by:

• Stockpiles

• Lagoons

• Tanks, open top or enclosed

• Digesters

It is important to remember that if sewage sludge re-
mains on land (e.g., in stockpiles or lagoons) for longer
than 2 years, the surface disposal requirements  in the
Part 503 rule must  be met. Chapter  15 of the EPA
Process Design Manual for Sludge Treatment and Dis-
posal (U.S. EPA, 1979) contains a comprehensive dis-
cussion of sewage sludge storage design options and
applicable  detention times for each type of storage
structure (see Table 15-1 in that manual) and should be
consulted for more details. The different types of storage
systems are summarized below.
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14.3.4.1   Stockpiles
14.4 Land Application Methods
Stockpiling involves the temporary storage of sewage
sludge that has been stabilized and dewatered or dried
to a concentration (about 20 to 60 percent solids) suit-
able for mounding with bulldozers or loaders. The sew-
age sludge is mounded into stockpiles 2 to 5 m (6 to 15
ft) high, depending on the quantity of sewage sludge and
the  available land area. Periodic turning of the sewage
sludge helps to promote drying  and maintain aerobic
conditions. The process is most applicable in arid and
semiarid regions, unless the stockpiles are covered  to
protect  against rain. Enclosure  of stockpiles may be
necessary to control runoff.


14.3.4.2  Lagoons

Lagoons are often the least  expensive way to store
sewage sludge. With proper design, lagoon detention
also provides additional  stabilization  of the sewage
sludge and reduces pathogens.


14.3.4.3  Tanks

Various types  of tanks can be used to store sewage
sludge. In  most  cases, tanks are an  integral part  of
sewage sludge treatment processes at a POTW, and the
design for these  processes  usually includes storage
capabilities. A mobile storage tank (nurse tank) in the
field can serve as a buffer between the transportation
and application of sewage sludge, allowing the  opera-
tors to work somewhat independently of one another.
The Madison, Wisconsin, program uses such a system
and as a result has observed a 25 percent increase  in
its productivity (Jacobs et al., 1993). Liquid sewage
sludge is transported at the Madison site using  5,500-
gallon vacuum trucks that discharge the sewage  sludge
into a 12,000-gallon mobile storage tank located at the
application site. A 3,500-gallon application vehicle with-
draws sewage sludge from the storage tank and  injects
the  sludge 6 to 8 inches beneath the soil surface. Two
truckloads normally fill one storage tank and application
vehicle (Jacobs et al., 1993).
14.3.4.4   Treatment Plant Digester Capacity

Many sewage treatment plants do  not have separate
sewage sludge retention capacity, but rely on portions
of the digester volume for storage. When available, an
unheated sewage sludge digester may provide short-
term storage  capacity. In anticipation of periods when
sewage sludge cannot be applied to the land, digester
supernatant withdrawals can be accelerated to provide
storage of sewage sludge for several weeks.
14.4.1   Overview

The technique used to apply sewage sludge to the land
can be influenced by the means used to transport the
sludge from the treatment works to the land application
site. Commonly used  methods include:

• The same transport vehicle hauls the sewage sludge
  from the treatment  works to the application site and
  applies the  sewage sludge to land.

• One type of transport vehicle,  usually with  a  large
  volume capacity, hauls sewage sludge from the treat-
  ment works to the application site. At the application
  site, the haul vehicle transfers  the sewage sludge
  either to an application vehicle, into a storage facility,
  or both.

• Sewage sludge is pumped and transported by pipe-
  line from the treatment works to a storage facility  at
  the application site. Sewage sludge is subsequently
  transferred from the storage facility to an application
  vehicle.

Sewage sludge land application methods involve either
surface or subsurface application. Each has advantages
and disadvantages that are discussed in the following
subsections. With all  of the application techniques, the
sewage  sludge eventually become incorporated into the
soil, either immediately by mechanical means or over
time by natural means.

Sewage sludge is applied either in liquid or dewatered
form. The methods and equipment used are different for
land  application of these two types of sewage sludge,
and each has advantages and disadvantages that are
highlighted below.

Regardless of the type of application system chosen  at
a land application  site, attention must be paid to poten-
tial physical problems of the soil at the site. One  study
of sewage sludge land application programs determined
that farmers who participate in such programs are very
concerned about soil  compaction (Jacobs et al., 1993).
Programs in Wisconsin, Colorado, and Michigan  using
private farmland have found that  attention to potential
soil compaction as well as deep tilling the staging areas
when land application is completed is important. Long-
term working relationships with farmers have been en-
hanced in these programs by managing equipment and
field applications to avoid soil compaction (Jacobs et al.,
1993).

14.4.2  Application of Liquid Sewage Sludge

Application of sewage sludge to land  in liquid form  is
relatively simple.  Dewatering  processes  are  not re-
quired, and the liquid sewage sludge can  be readily
                                                 171

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pumped. Liquid sewage sludge application systems in-
clude:

• Vehicular surface application by:
  - Tank truck spreading, or
  - Tank wagon spreading

• Subsurface application by:
  - Subsurface injection, or
  - Plow furrow or disking methods

• Irrigation application by:
  - Spray application, or
  - Flood irrigation (gravity flooding)

14.4.2.1   Surface Application

Surface  application of liquid sewage  sludge involves
spreading  without subsequent  incorporation into the
soil. Surface application of sewage sludge  has  been
shown to reduce nutrient and soil loss on no-till cropland
that would otherwise occur through surface water runoff
using  other application methods. Surface application
may also have similar benefits on conventionally tilled
cropland (Elliott et al., 1990).

Vehicle  Types Available

Table 14-5 describes the methods, characteristics, and
limitations of applying liquid sewage sludge by surface
application. Liquid sewage sludge can be spread on the
soil surface using application vehicles equipped  with
splash plates,  spray bars, or nozzles. Uniform applica-
tion is the most important criterion in selecting which of
the three attachments are best suited to an individual
site. Figure 14-6  depicts a tank truck equipped with
splash plates.  Figure  14-7 depicts a tank truck with a
rear-mounted "T" pipe.  Forthesetwo methods, application
rates can be controlled either by valving the manifold or
Table 14-5.
Method
           Surface Application Methods for Liquid Sewage
           Sludge (Cunningham and Northouse, 1981)
            Characteristics
                                     Topographical and
                                     Seasonal
                                     Limitations
Tank truck    Capacity 500 to more than
            2,000 gallons; flotation tires
            desirable; can be used with
            temporary irrigation set-up;
            can achieve a uniform
            application rate with pump
            discharge.

Farm tank    Capacity 500 to 3,000
wagon       gallons; wagon flotation tires
            desirable; can be used with
            temporary irrigation set-up;
            can achieve a uniform
            application rate with pump
            discharge.
Tillable land; not
usable at all times
with row crops or
on very wet ground.
Tillable land; not
usable at all times
with row crops or
on very wet ground.
                    by varying the speed of the truck. A much heavier appli-
                    cation will be made from a full truck than from a nearly
                    empty truck or wagon unless the speed of the truck or
                    wagon advancing across the field is steadily decreased
                    to compensate for the steadily decreasing  hydraulic
                    head (U.S. EPA, 1977). Figure 14-8  depicts a  spray
                    nozzle mounted on a tank truck. By spraying  the liquid
                    sewage sludge under pressure, a  more uniform cover-
                    age  is obtained.

                    Hauling a full tank of sludge across the application site
                    compacts the soil  (Elliott et al., 1990). Conveyance of
                    Figure 14-6.  Splash plates on back of tanker truck (U.S. EPA,
                                1978).
                    Figure 14-7.  Slotted T-bar on back of tanker truck (U.S. EPA,
                                1978).

Metric conversion factor: 1 gal = 3.78 L
                    Figure 14-8.  Tank truck with side spray nozzle for liquid sludge
                                surface application (U.S. EPA, 1978).
                                                     172

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the tank can  be eliminated by using a travelling spray
gun connected directly to the  sludge delivery vehicle.
Distribution and drift problems can be reduced by using
a "traveling beam" with multiple sprinklers (Elliott et al.,
1990).

14.4.2.2  Subsurface Application

Subsurface application of liquid sewage sludge involves
either subsurface injection or subsurface incorporation
using plow furrow or disking methods. One study found
that the majority of 10 land application  programs ana-
lyzed use  subsurface injection or surface spreading fol-
lowed by incorporation because these procedures have
proven to be the most effective means of reducing odors
and improving public acceptability of the program (Ja-
cobs et al., 1993). Therefore, the study recommended
the incorporation of sewage sludge into the soil at land
application sites as soon as possible.

Subsurface injection or soil incorporation of liquid sew-
age sludge has a number of advantages over surface
application, including:

• Potential health and nuisance problems generally can
  be avoided. The vector attraction reduction require-
  ments of Part 503 can be met using these subsurface
  methods of land application when sewage  sludge or
  domestic septage is applied to certain types of land
  (see Chapter 3).

• Nitrogen is conserved  because ammonia  volatiliza-
  tion is minimized.

• Public acceptance  may be better.

Injection of sewage sludge beneath the soil places a
barrier of earth between the sewage sludge and vectors
such as flies or rodents that could transmit disease (U.S.
EPA,  1992).  In  addition, when sewage sludge is in-
jected, the soil quickly removes water from the sewage
sludge, which reduces its mobility and odor (U.S. EPA,
1992). As  a result, the requirements for vector attraction
reduction  in the Part 503  rule can be demonstrated for
certain  types of land  by  injecting the sewage sludge
below  the ground.  Under this option,  no  significant
amount of the sewage sludge can be present on the land
surface within 1 hour after injection, and, if the sewage
sludge is Class A with respect to pathogens, it must be
injected within 8 hours after discharge from the  patho-
gen-reduction process (see Chapters).

The requirements for vector attraction reduction under
the Part 503  rule also can be demonstrated for certain
types of land  by incorporating sewage sludge  applied to
the land within 6 hours after application (see Chapter 3).
If the sewage sludge is Class A with  respect to  patho-
gens, the time between processing and application must
not exceed 8 hours. After application, the sewage sludge
has to be incorporated into the soil within 6 hours. When
applied  at agronomic  rates, the loading of sewage
sludge solids typically is about 1/200th of the mass of
soil in the plow layer. If mixing is reasonably good, the
dilution of sewage sludge in the soil surface from incor-
poration is equivalent to that achieved with soil injection
(U.S. EPA, 1992).

The 6 hours allowed in the regulation to complete the
incorporation of sewage sludge into the soil should be
adequate to allow for proper incorporation. As a practical
matter, it may be wise to complete the incorporation in
a much shorter time. Clay soils tend to become unman-
ageably slippery and muddy if the liquid sewage sludge
is allowed to soak into the first inch  or two of topsoil
(U.S. EPA, 1992).

Some state requirements for the incorporation of sew-
age sludge once it is land applied may be more  stringent
than federal requirements. For example,  Kentucky re-
quires incorporation of sewage sludge within 2 hours of
application for odor control (U.S. EPA, 1990).

Subsurface injection or soil incorporation of liquid sew-
age sludge also has potential disadvantages, however,
compared  to  surface  application of  liquid  sewage
sludge, including:

• Potential difficulty in achieving even distribution of the
  sewage sludge.

• Higher fuel consumption costs.

Vehicle Types Available

Table 14-6 describes the methods, characteristics, and
limitations of applying liquid sewage sludge  by subsur-
face application. Figures 14-9 and 14-10 illustrate equip-
ment specifically designed for subsurface injection of
sewage sludge, which involves tank trucks with special
injection equipment attached. Tanks for the  trucks are
generally  available with 6,000, 7,500, and  11,000  L
(1,600, 2,000, and 3,000 gal) capacities.  Figure 14-11
shows anothertype of unit, atractorwith a rear-mounted
injector unit; sewage sludge  is pumped from a storage
facility to  the injector unit through a flexible  hose at-
tached to  the tractor. Discharge flow  capacities of 570
to  3,800 L/min  (150 to  1,000 gal/min) are  used.  The
tractor requires a power rating of 40 to 60 hp.

It is not usually  necessary to inject liquid sewage sludge
into the soil when the sludge is applied to existing pasture
or hay fields; however, injection systems are available that
can apply liquid sewage sludge to these  areas with a
minimum of crop and soil disturbance (see Figure 14-10).

Soil compaction problems still exist when using injec-
tors. The use of a heavy tank in the field can be avoided
by attaching injectors directly to a tractor tool bar. Sludge
can then be pumped to the injectors from a storage area
or nurse truck  using an umbilical hose (Elliott  et al.,
1990).
                                                  173

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Table 14-6.  Subsurface Application Methods for Liquid Sewage Sludge (Keeney et al., 1975)
Method
                          Characteristics
                                                                                            Topographic and
                                                                                            Seasonal Limitations
Flexible irrigation hose
with plow or disk cover

Tank truck with plow or
disk cover

Farm tank wagon with
plow or disk cover
Subsurface injection
Use with pipeline or tank truck with pressure discharge; hose connected
to manifold on plow or disc.

500-gallon commercial equipment available; sludge discharged in furrow
ahead of plow or disk mounted on rear on four-wheel-drive truck.

Sludge discharged into furrow ahead of plow mounted on tank trailer;
application of 170 to 225 wet Tons/acre; or sludge spread in narrow
band on ground surface and immediately plowed under; application of
50 to 120 wet Tons/acre.

Sludge discharged into channel opened by a chisel tool mounted on
tank truck or tool bar; application rate 25 to 50 wet Tons/acre; vehicles
should not traverse injected area for several days.
Tillable land; not usable on
very wet or frozen ground.

Tillable land; not usable on
very wet or frozen ground.

Tillable land; not usable on
very wet or frozen ground.
Tillable land; not usable on
very wet or frozen ground.
Metric conversion factors: 1 gal = 3.78 L, 1 Ton/acre = 2.24 metric tons/hectare


                                     —- a-"4t - * > -,»  ?-*-<'S

                                          *f?-^ ••!%•;
Figure 14-9.  Tank truck with liquid sludge tillage  injectors
            (courtesy of Rickel Manufacturing Company).
Figure 14-10.  Tank truck with liquid sludge grassland injectors
             (courtesy of Rickel Manufacturing Company).
                                                           Figure 14-11.  Tractor-pulled liquid sludge subsurface injection
                                                                        unit connected to delivery hose (courtesy of Bris-
                                                                        coe Maphis Company).
                                  An example of a land application program using injec-
                                  tion is the Madison, Wisconsin, program.  The sewage
                                  sludge  injection vehicles  used in  this  program have
                                  been  modified  by increasing  the number of injection
                                  shanks to 6 per vehicle and by adding a drag behind the
                                  injectors to smooth the disturbed  soil (Jacobs et al.,
                                  1993). Another example is an Arizona program in which
                                  sewage sludge is land applied with a tractor-mounted
                                  injector. The injectors are supplied with sludge through
                                  a hose connected to the pipe system. A second tractor
                                  pulls  the  hose  out of the  way as the  injecting  tractor
                                  traverses the application fields. Sewage  sludge is  in-
                                  jected in a triple Crosshatch pattern for uniform distribu-
                                  tion (Jacobs et  al., 1993).

                                  The plow or disk and cover method involves discharging
                                  the sewage sludge into a narrow furrow from a  wagon
                                  or flexible hose linked to  a storage facility through a
                                  manifold mounted on the plow or disk; the plow  or disk
                                  then  immediately covers the sewage sludge with soil.
                                  Figure  14-12 depicts a typical  tank wagon with an  at-
                                  tached  plow. These systems seem to be best suited  for
                                  high  loading rates, i.e., a minimum of 3.5 to 4.5 t/ha (8
                                  to 10  dry T/ac)  of 5 percent slurry.
                                                        174

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Figure 14-12a.  Tank wagon with sweep shovel injectors (Cun-
             ningham and Northouse, 1981).
Figure 14-12b.  Sweep shovel injectors with covering spoons
             mounted on tank wagon (Cunningham and Nort-
             house, 1981).
14.4.2.3   Irrigation Application

Irrigation application of liquid sewage sludge has been
accomplished using spray irrigation and flood irrigation.
Spray irrigation has been used primarily for forest land
applications; its usefulness for agricultural applications
may be limited by cropping schedules and public accep-
tance (see Chapter?). Flood irrigation of sewage sludge
generally has  not been successful and is  usually dis-
couraged by regulatory agencies.

Spray Irrigation

Spray irrigation has been used to disperse  liquid sew-
age sludge on clearcut openings and in forest stands.
Liquid sewage sludge is readily dispersed through spray
systems if properly designed equipment is used.  Solids
must be relatively small and uniformly distributed through-
out the sewage sludge to achieve uniform application and
to avoid  system clogging. A typical spray application
system consists of the use of a rotary sprayer (rain gun)
to disperse the liquid sewage sludge over the applica-
tion site.  The sludge, pressurized by a pump, is trans-
ferred from storage to the sprayer via a  pipe system.
Design of the system can be portable or permanent and
either mobile  or stationary.  Available spray irrigation
systems include (Loehr et al., 1979):

• Solid set, both buried  and  above ground

• Center pivot

• Side roll

• Continuous travel

• Towline laterals

• Stationary gun

• Traveling gun

The utility of these systems  within the application site
depends  on the application schedule and  management
scheme utilized. All the  systems listed, except for the
buried solid system, are designed to be portable. Main
lines  for systems  are   usually permanently  buried,
providing protection from freezing weather and heavy
vehicles.

The proper design of sewage sludge spray application
systems requires thorough knowledge of  the commer-
cial equipment available and  its  adaptation for use with
liquid  sewage sludge. It is beyond the scope of this
manual to present engineering  design  data  for these
systems, and  it is suggested that qualified irrigation
engineers and experienced irrigation system  manufac-
turers be consulted.

Figures 14-13, 14-14, and 14-15 illustrate some of the
spray systems listed above.

Flood Irrigation

In general, land application of sewage sludge by flood
irrigation, also known as gravity flooding,  has not been
successful where  attempted and  is discouraged  by
regulatory agencies and experienced designers. Prob-
lems arise from (1) difficulty  in achieving  uniform sew-
age sludge application rates; (2) clogging  of soil pores;
and (3) tendency of the sewage sludge to turn septic,
resulting  in odors.

14.4.3   Application of Dewatered Sewage
         Sludge

Dewatered sewage sludge is applied to land by surface
application techniques. The principal advantages of us-
ing dewatered sewage sludge are:

• Reduced sewage sludge hauling and storage costs.
                                                  175

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Figure 14-13.  Center pivot spray application system (courtesy
            of Valmont Industries Inc.).
                                                        Figure 14-14.  Traveling gun sludge sprayer (courtesy of Lind-
                                                                    say Manufacturing Company).
                       IRRIGATION

                      GUN & STAND
BOOSTER
 PUMP
3" BALL VALVE
                    4" PIPELINE
                                3" LEVER ACTION
                                   VALVE (2)
                                            PLASTIC LINER
Figure 14-15.  Diagram of liquid sludge spreading system in forest land utilizing temporary storage ponds (Water Pollution Control
            Federation, 1981).
• The ability to apply sewage sludge at higher applica-
  tion rates with one pass of the equipment.

Potential disadvantages of applying dewatered sewage
sludge are:

• Generally, substantial modification of conventional spread-
  ing equipment is necessary to apply dewatered sludge.

• More operation  and maintenance is  generally  in-
  curred in equipment repairs compared to many liquid
  sewage sludge application systems.

Table 14-7 describes methods and equipment for apply-
ing dewatered sewage sludge to the land.

Table 14-7.  Methods and Equipment for Application of
          Dewatered Semisolid and Solid Sludges

Method    Characteristics

Spreading  Truck-mounted or tractor-powered box spreader
          (commercially available); sludge spread evenly on
          ground; application rate controlled by PTD and/or
          over-trie-ground speed; can be incorporated by
          disking or plowing.
Piles       Normally hauled by dump truck; spreading and
          leveling by bulldozer or grader needed to give
          uniform application.
                     14.4.3.1   Vehicle Types Available

                     Spreading  of dewatered  sewage sludge is similar to
                     surface application of solid orsemisolid fertilizers, lime,
                     or animal manure. Dewatered sewage sludge cannot be
                     pumped or sprayed. Spreading is done by box spread-
                     ers, bulldozers, loaders, or graders, and the sludge is
                     then plowed or disked into the soil. The box spreader is
                     most commonly used,  with the other three  equipment
                     items generally being used only for sites with high sew-
                     age sludge application  rates.

                     Figures  14-16  and  14-17 illustrate the specially  de-
                     signed trucks used to spread dewatered sewage sludge.
                     For small quantities of dewatered sludge, conventional
                     tractor-drawn farm manure spreaders may be adequate
                     (Loehr et  al., 1979). Surface spreading of dewatered
                     sludge on tilled  land usually is followed by incorporation
                     of the sludge into the soil. It is not usually necessary to
                     incorporate dewatered  sludge into the soil  when  the
                     sludge is applied to existing pasture or hay fields. Stand-
                     ard agricultural disks or other tillage equipment pulled
                     by a tractor or bull dozer can incorporate the dewatered
                     sludge into the soil, such as the disk tiller, disk plow,  and
                     disk harrow (Figures 14-18 and 14-19).

                     In  Denver, Colorado, spreaders  were  custom-built to
                     provide a more even application  of dewatered  sewage
                                                    176

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       -16.  A 7.2-cubic-yard  dewatered  sludge spreader
            (courtesy of Big Wheels Inc.).
Figure 14-17.  Large dewatered sludge spreader (courtesy of BJ
            Manufacturing Company).
Figure 14-18.  Example of a disk tiller.
Figure 14-19.  Example of a disk plow.
sludge than commercially available spreaders (Jacobs
et al., 1993). The district's spreaders have a metering
screw and gauge  that allow the operator to achieve
relatively even applications.  In addition, the district in-
stalled a heating system on the spreader box, which
allowed the sewage sludge to be spread during the
winter months. Following surface application, the sew-
age sludge at the  Denver site is incorporated into the
soil by disking or plowing (Jacobs et al., 1993).

In Sparks, Nevada, dewatered sewage sludge is un-
loaded at the application site into a windrow at the edge
of the spreading  area.  The  sludge  unloading area
changes as the spreading area changes, thus avoiding
the development of "hot spots" with extremely high sew-
age sludge loadings (Jacobs  et al., 1993).  From the
windrow, a front-end loader places the sludge into a
side-slinger manure spreader, which spreads the sludge
onto the field. The  same person operates the front-end
loader and the spreader. Fields are spread in sections,
with the length of a section determined  by the distance
required to empty a spreader; a spreader swath usually
is approximately 80 feet wide by 200 feet long. The
tractor to  which  the spreader  is attached is  equipped
with  hydraulic drive to facilitate speed changes. The
side-slinger design enables the tractor and spreader to
travel on ground that has not yet received sludge appli-
cation, thus keeping the equipment clean. At the end of
each day,  the field is disked twice to completely cover
the sewage sludge with soil (Jacobs et al., 1993).

14.5  Site Preparation

14.5.1  General

For agricultural land application systems where sewage
sludge is applied to privately owned farms at low agro-
nomic application rates,  site  modifications are not typi-
cally cost-effective. At forested systems, usually there is
much more forest  land available within the local area
than is needed  for sewage sludge land application, so
unsuitable land can be avoided rather than modified. In
the case of land application of sewage sludge at recla-
mation sites, extensive site grading and soil preparation
often are necessary. These site preparation costs, how-
ever, are usually borne by the land owner (e.g.,  mining
company,  ore processor, etc.) and not by the municipal-
ity (see Chapter 9 for a discussion of land application of
sewage sludge at reclamation sites).

14.5.2  Protection of Ground Water and
        Surface Water Quality

One of the major environmental tasks  at a sewage
sludge land application site is the prevention of surface
and subsurface water contamination by constituents in sew-
age sludge. Nitrogen and phosphorus in surface waters and
nitrate in ground water are usually the constituents of most
                                                  177

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concern. The Part 503 pollutant limits and agronomic
rate requirement address these water quality concerns.
Good management practices, such as incorporating or
injecting sewage sludge, minimize the amount of sludge
that  can come into contact with rain, thus reducing
potential water contamination (Lue-Hing et al., 1992). If
runoff might occur from a land application site, the water
quality of the runoff should be  within acceptable limits,
or the water can be detained in a holding structure and
reapplied to land  or treated  (Lue-Hing  et al.,  1992).
Ways to reduce potential water contamination  include
grading and erosion control, as discussed below.

14.5.3  Grading

The purpose of establishing surface grades is to ensure
that  runoff  water and/or  liquid sewage sludge do  not
pond. Design plans should emphasize that depressions
can be filled with soil from adjoining ridges and mounds.
If an  excessive amount of filling is required for low areas,
or if  sufficient soil  is not readily available, field ditches
can be installed and the surfaces warped towards them.
In areas with little or no slope, grades can be established
or increased by grading between parallel ditches with
cuts  from the edge of one ditch and fills from the next.

Terraces may  be needed to protect lower  lands from
surface water  runoff that can  cause soil  erosion. Ter-
races generally are dug across a slope or at the toe of
a slope, with the borrow material diked on the lower side
for efficiency. Diversion terraces generally are graded
and grass-covered so that the collected water may be
delivered at non-erosive flows to a controlled discharge
point.

A number of states have requirements for the maximum
grade allowable at land application sites and for runoff
control (U.S. EPA, 1990). Requirements for runoff con-
trol  range  from  forbidding application  on  saturated
ground, as in Mississippi, to specifying designs for runoff
control  systems (e.g., capacity for a  10-year,  1-hour
storm), as in Texas.

14.5.4 Erosion Control

The measures used to prevent soil erosion include strip
cropping, terraces, grassed waterways, and  reduced
tillage  systems (e.g., chisel plowing,  no-till planting).
Strip cropping  involves planting alternating strips (e.g.,
hay and corn) so that when one crop is harvested, soil
erosion from the  harvested strips is contained  by  the
strips that remain vegetated. The strips are alternated
periodically. The  presence of vegetation  and/or crop
residues on the soil  surface  is effective  in reducing
runoff from steeply sloping soils. For many cropping
systems (e.g.,  corn,  soybeans, small grains),  liquid
sludge applied to the surface is  incorporated into the soil
by plowing  or disking prior to crop planting, further re-
ducing the  potential for loss of sludge constituents via
surface runoff. In essence, selection of the proper sludge
application method (surface or incorporation) in con-
junction with currently recommended practices for con-
trol of soil erosion will essentially eliminate the potential
contamination of surface waters or adjacent lands by
sewage sludge constituents.

Every land application site should be designed to mini-
mize soil erosion. The MWRD in Denver, Colorado, for
example,  performs soil management practices recom-
mended by the Department of Agriculture  Natural Re-
sources Conservation Service (NRCS) and the Consolidated
Farm Service Agency (formerly Agriculture  Stabilization
and Conservation Service) to help reduce the potential for
soil erosion. Information on  proper slopes, effective con-
servation tillage, and wind erosion techniques for agricul-
tural lands can be obtained from the NRCS.

14.6  Design  of Supporting  Facilities

The cost  of supporting facilities, such  as permanent
all-weather access  roads  and fences, can usually be
justified only for sites with high sewage sludge applica-
tion rates that will be used over a long project life. These
conditions  rarely apply to privately owned agricultural
land application sites.

14.6.1  Access Roads

A permanent road should  be provided from the public
road system to the land application site. For large sites,
the roadway should be 6.5 to 8 m  (20 to 24 ft) wide to
allow for two-way traffic; for smaller sites, a 5 m (15 ft)
wide road should suffice. To provide all-weather access,
the roadway,  at a minimum, should be gravel-surfaced,
preferably with asphalt pavement. Grades should  not
exceed equipment limitations. For loaded vehicles, up-
hill grades should be less than 7 percent.

14.6.2  Public Access: Site Fencing  and
         Security

Under the Part 503 rule, public access restrictions apply
to land application sites where sewage sludge meeting
Class B pathogen requirements is applied (see Chapter
3). Access to lands with a high potential for public expo-
sure, such as parks or ballfields, must be restricted for
1 year after sewage sludge application. Examples of
restricted  access include remoteness, posting with "no
trespassing" signs, and/or fencing. Access to  land with
a low potential for public exposure (e.g., private farm-
land) must be restricted for 30 days after sewage sludge
application.

Depending on the topography and vegetation of the site
and adjoining areas,  entrance gates may suffice to pre-
vent unauthorized vehicular access. At some sites, it will
be necessary to construct peripheral fences to restrict tres-
passers and animals. Fencing requirements are influenced
                                                  178

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by the relative isolation of the site. Sites close to resi-
dences will require fencing. Facilities that are in rela-
tively  isolated,   rural  areas  may  require  a  less
sophisticated type of fence or only fencing at the en-
trance and other select places  to keep unauthorized
vehicles out.

14.6.3  Equipment and Personnel Buildings

Application equipment and  staging areas should  be
managed at land application facilities in ways that avoid
compaction of soils receiving sewage sludge (Jacobs et
al., 1993). Avoidance of potential compaction problems
will enhance the long-term working  relationship between
a treatment works and crop producers.

At larger facilities, or where climates are extreme, build-
ings may be necessary for  office space, equipment, and
employees. Where land application sites are operated
throughout the year,  some  protection from the elements
for employees and equipment may be necessary. Sani-
tary facilities should  be provided for both site and haul-
ing  personnel. At  smaller  facilities  where buildings
cannot be justified, trailers may be warranted.

14.6.4  Lighting and Other Utilities

If land application operations occur at night, portable
lighting should be provided at the operating area. Lights
may be affixed to haul vehicles and on-site equipment.
These lights should  be situated  to provide illumination
to areas not covered  by the  regular headlights of the
vehicle.  If the facility has structures  (e.g.,  employee
facilities, office buildings, equipment repair or storage
sheds) or  if the access road  is in continuous use, per-
manent security lighting may  be  needed.

Larger sites may need electrical,  water, communication,
and sanitary services. Remote sites may have to extend
existing services or use acceptable substitutes. Portable
chemical toilets can  be used  to  avoid the  high cost  of
extending sewer lines; potable water may be trucked in;
and  an electrical  generator  may  be used instead  of
having power lines run on-site.

Water should  be available for drinking, dust  control,
washing mud from haul vehicles before entering public
roads, and employee sanitary facilities. Telephone  or
radio communications may  be  necessary since  acci-
dents or spills can occur that necessitate the ability  to
respond to calls for assistance.
14.7  References

Cunningham, J., and M. Northouse. 1981. Land application of liquid
   digested sewage sludge (METROGRO) at Madison, Wisconsin.
   In: Seminar proceedings, land application of sewage sludge. Vir-
   ginia Water Pollution Control Association, Inc., Richmond,  VA.
   pp. 111-145.

Elliott, H., B. Dempsey, D. Hamilton, and J. Wolfe. 1990. Land appli-
   cation of water treatment plant sludges: Impact and management.
   American Water Works Research Foundation, Denver, CO.

Ettlich, W 1976. What's best for sludge transport? Water Wastes
   Engin. 13(10):20-23.

Haug, R., L. Tortorici, and S.  Raksit.  1977. Sludge processing  and
   disposal. LA/OMA Project, Whittier, CA.

Jacobs, L.,  S. Carr,  S. Bohm, and J. Stakenberg. 1993.  Document
   long-term experience of sewage  sludge land  application  pro-
   grams. Water Environment  Research Foundation, Alexandria, VA.

Keeney, D., K. Lee, and L. Walsh. 1975. Guidelines for the application
   of wastewater sludge to agricultural land in Wisconsin. Technical
   Bulletin No. 88,  Wisconsin Department of Natural Resources,
   Madison, Wl.

Loehr, R., W. Jewell, J. Novak, W. Clarkson, and G. Friedman. 1979.
   Land application  of wastes, Vol. 2. New York, NY:  Van Nostrand
   Reinhold.

Lue-Hing, C., D. Zenz, and R.  Kuchenrither. 1992. Municipal sewage
   sludge  management: Processing, utilization, and  disposal. In:
   Water quality management library, Vol. 4.  Lancaster,  PA: Tech-
   nomic Publishing Co.

Taylor, D. June 1994. Revision, projected monthly sludge distribution
   for agricultural sludge utilization program, Madison, Wl.

U.S. EPA. 1992. Control of pathogens and vector attraction in sewage
   sludge. EPA/625/R-92/013. Washington, DC.

U.S. EPA. 1990. Guidance for writing case-by-case permit require-
   ments for  municipal sewage sludge.  EPA/505/8-90/001. Wash-
   ington, DC.

U.S. EPA. 1979. Process design manual for sludge treatment  and
   disposal. EPA/625/1-79/011. Washington, DC.

U.S. EPA.  1978. Sludge treatment and disposal, Vol.  2. EPA/625/4-
   78/012. Cincinnati, OH.

U.S. EPA. 1977a. Cost of land spreading and hauling sludge from
   municipal wastewater treatment plants—Case studies. EPA/30/
   SW-619. Washington, D.C.

U.S. EPA. 1977b. Transport of sewage sludge. EPA/600/2-77/216.
   Washington, DC.

Water Pollution Control Federation. 1981. Design of wastewater and
   stormwater pumping stations. In: Manual of practice FD-4. Wash-
   ington, DC.
                                                       179

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                                           Chapter 15
                        Management, Operational Considerations,
                             and Recordkeeping and Reporting
15.1  Sewage Sludge Management Plans

In accordance with the Clean Water Act of 1987, EPA
must include sludge requirements in NPDES permits to
protect public health and the environment. To determine
appropriate requirements for land  application, EPA re-
quests information from the applicant receiving a permit
on current sewage sludge handling and use practices,
and a 5-year sludge operating plan  that describes an
applicator's sludge marketing areas  and planning  pro-
cedures for new sites (U.S. EPA, 1993a). This Sludge
Management Plan must be included with the  permit
application. In addition, the Plan acts as a blueprint for
sludge activities (U.S. EPA, 1993a),  and fulfills the re-
quirement of 40 CFR Part 501 that  both  NPDES and
non-NPDES entities prepare a land application plan for
sewage sludge.  The  major elements of a Sludge Man-
agement Plan are  summarized in Figure 15-1.

EPA will discuss current practices and new site operat-
ing  procedures outlined  in a Sludge Management Plan
with personnel in  state environmental  programs  and
with the USDA Soil Conservation Service  and/or State
Extension Service in counties where sludge might be
marketed as part of the  permitting process (U.S. EPA,
1993a). Upon approval of a Sludge Management Plan by
EPA, the plan becomes an enforceable part of the  permit.

In addition to sludge  management  plans, all land appli-
cation operation managers should prepare an operation
program, with responsibility clearly  defined for its imple-
mentation. Essential elements of the operation program
include:

• Flexible scheduling of sludge transport,  storage, and
  application activities to accommodate  a  treatment
  works  need to  remove sludge, as well as design
  needs for land application of the sludge to the site(s).

• Design, management, operation, and maintenance of
  the sludge transport system to minimize  potential nui-
  sance and health  problems. The system should in-
  clude a procedure for rapid response to accidents,
  spills, and other emergency conditions that may arise
  during routine sludge transport operations.
• Design, management, operation, and maintenance of
  the sludge application site(s) and equipment to mini-
  mize potential nuisance and health problems. Where
  privately owned and operated land is involved (e.g.,
  farms,  commercial forest land,  mined lands), the
  owner/operator is a key participant in the overall ap-
  plication site management and operation program.
• Recordkeeping, including adequate documentation of
  program activities. See Section 15.6 for a discussion
  on recordkeeping at land application sites.
• Health and safety, including  necessary, routine pro-
  cedures for protecting the general public and opera-
  tions personnel.

15.2 Part 503 Requirements Affecting
      Land Application Site Operation
Under the Part 503 regulation,  Class B site restrictions
must be met at land application sites where  sewage
sludge  meeting Class B pathogen requirements is ap-
plied (U.S. EPA, 1994a). The Class B site restrictions in
Part 503  include restrictions for harvesting crops and
turf, grazing animals, and limiting public access  to these
sites. Figure  15-2 describes these restrictions,  while
Figure 15-3 includes examples of crops impacted by the
Class B site restrictions. Also, see Chapter 3 for  required
Part 503 management practices.

15.3 Nuisance Issues
Minimizing adverse aesthetic  impacts of a  sewage
sludge  land application system will aid in maintaining
public acceptance of the project. Conscientious house-
keeping can  help make the difference between public
perception of the operation  as a professional endeavor
and public disapproval of the project. The following fea-
tures reflect good housekeeping (Elliott et al., 1990):
• Well  maintained, clean vehicles.
• Application and storage  areas that  are well kept,
  clean, and fenced, if necessary.
• Satisfied land owners.
• Well  kept records.
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As part of the  NPDES permit application, submit to EPA a Sludge
Management Plan (Plan). The Plan includes current sludge
practices and a 5-year sludge operating plan as listed below.


 A.  A description of the  permittee's sludge production and any cur-
     rent and known future land application sites.
 B.  A list of the counties (and states if applicable) where the  permit-
     tee may want to market or distribute its sludge over the life of
     the permit (5 years minimum).  A copy of the plan must be sub-
     mitted to the respective State Health Department, and should
     be submitted to the  State Extension Service Office in the coun-
     ties where sludge may be marketed.
 C.  Site selection criteria to be used when identifying new land ap-
     plication sites.
 D.  Site management practices being followed relating to, at a mini-
     mum: floodplain, slope, depth to ground water, weather condi-
     tions, soil conditions (compaction, permeability, saturated,
     frozen, snow-covered), site access, and protection of surface
     waters, wetlands, endangered  species, and underground drink-
     ing water sources at current  sites; and operating procedures
     (e.g., qualified soils consultant, Soil Conservation Service,
     State Extension Service) for  annual adjustments and for set-
     ting  site management practices for future sites.
 E.  Buffer zones between sludge application sites and: surface wa-
     ters, drinking water wells, drainage ditches, property lines, resi-
     dences, schools, playgrounds, airports, public  roadways, and
     any  necessary site-specific buffer zones for current sites; and
     operating procedures (e.g., qualified soils consultant, Soil Con-
     servation Service, State Extension Service) for making annual
     adjustments and for setting buffer zones for future sites.
 F.  Storage provision for sludge  during periods when sludge can-
     not be land applied.
 G.  Either Part 503 pollutant concentration limits, or maximum ac-
     ceptable total cumulative application rates, expressed as kilo-
     grams per hectare (kg/ha) (or annual application rates for
     bagged sewage sludge, kg/ha/yr), for arsenic, cadmium, chro-
     mium, copper, lead, mercury,  molybdenum nickel, selenium, and
     zinc, and any other pollutants regulated by the Part 503 rule.
 H.  Maximum acceptable sludge application rate to assure that the
     amount of sludge applied does not exceed the nutrient require-
     ments of the particular crop grown on the application site (agro-
     nomic rates) for current year crops, and operating procedures
     (e.g., by qualified soils consultant, Soil Conservation Service,
     State Extension Service) for  making annual agronomic rate ad-
     justments and for setting agronomic rates for future sites.
  I.  A description of the  pathogen treatment, vector attraction con-
     trol,  record keeping, monitoring, certifications, and notifications
     as required by the 40 CFR Part 503 regulation.
 J.  Reference to applicable regulations (40 CFR Part 503) and
     procedures the permittee intends to use to ensure that the
     sludge practices and limits outlined are followed.
 K.  Information described in 40 CFR 501.15(2) (states may require
     additional information).
 L.  Public notice  procedures and procedures for advanced notice to
     EPA (at least 60 days) of proposed new land application sites.
 M.  Procedures, or copies of documents specifying procedures
     (e.g., contracts) that will be used to ensure compliance with
     this permit and applicable regulations if the permittee contracts
     with others for assistance to  select and/or manage the land ap-
     plication sites itself.
 N.  Contingency plans that describe sludge disposal options for
     any  sludge which does not meet the requirements for land ap-
     plication or exceeds storage  capacity.
 O.  A statement (e.g., city ordinance) that the permittee will comply
     with the Sludge Management Plan, as approved by EPA.
 P.  A statement that the Plan will be amended  to reflect any  appli-
     cable practices or limits EPA promulgates pursuant to Section
     405 of the Act.

Figure 15-1.   Sludge Management Plan (U.S. EPA,  1993a).
Restrictions for the harvesting of crops* and turf:
 1.   Food crops, feed  crops, and fiber crops shall not be harvested
     until 30 days after sewage sludge application.
 2.   Food crops with harvested parts that touch the sewage
     sludge/soil mixture and are totally above ground shall not be
     harvested until 14 months after application of sewage sludge.
 3.   Food crops with harvested parts below the land surface where
     sewage sludge remains on the land surface for 4 months or
     longer prior to incorporation into the soil shall not be harvested
     until 20 months after sewage sludge application.
 4.   Food crops with harvested parts below the land surface where
     sewage sludge remains on the land surface for less than  4
     months prior to incorporation shall not be harvested until 38
     months after sewage sludge application.
 5.   Turf grown on land where sewage sludge is applied shall  not
     be harvested until 1 year after application of the sewage
     sludge when the harvested turf is placed on either land with a
     high potential for public exposure or a lawn, unless otherwise
     specified by the permitting authority.
Restriction for the grazing of animals:
 1.   Animals shall not be grazed  on land until 30 days after  applica-
     tion of sewage  sludge to the land.
Restrictions for public contact:
 1.   Access to land with a high potential for public exposure, such
     as a park or ballfield, is restricted for 1 year after sewage
     sludge application. Examples of restricted access include post-
     ing with no trespassing signs, and fencing.
 2.   Access to land with a low potential  for public exposure  (e.g.,
     private farmland)  is restricted for 30 days after sewage  sludge
     application. An example of restricted access is remoteness.

'Examples of crops  impacted by Class B pathogen requirements are
 listed in Figure 15-3.
Figure 15-2.
Restrictions for the harvesting of crops and
turf, grazing of animals, and public access on
sites where Class B biosolids are applied.
                    Harvested Parts That:
Usually Do Not Touch
the Soil/Sewage         Usually Touch the     Are Below the
Sludge Mixture         Soil/Surface           Soil/Surface
Peaches
Apples
Oranges
Grapefruit
Corn
Wheat
Oats
Barley
Cotton
Soybeans
Figure 15-3.
Melons
Strawberries
Eggplant
Squash
Tomatoes
Cucumbers
Celery
Cabbage
Lettuce

Examples of crops impacted
Potatoes
Yams
Sweet Potatoes
Rutabaga
Peanuts
Onions
Leeks
Radishes
Turnips
Beets
by site restrictions
                                                                                for Class B sewage sludge (U.S. EPA, 1994a).
                                                              182

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Continuous efforts should be made to avoid or reduce
nuisance problems associated with sludge hauling, ap-
plication, and related operations. Potential nuisances of
concern include odor,  spillage, mud,  dust,  noise, road
deterioration, and increased local traffic, as discussed
below.


15.3.1   Odor

All sludge management systems must consider objec-
tionable  odor as a potential problem.  Objectionable
odors could result in an unfavorable public reaction and
reduced acceptance of land application practices.

It is important to note that when pathogen reduction and
vector attraction reduction is achieved according to re-
quirements specified in the  Part 503 rule (see Chapter
3 fora complete discussion of these requirements), odor
should not pose a problem at land application sites. For
example, injection of sewage sludge beneath the soil
(Option 9 for demonstrating  reduced vector attraction of
sewage sludge) places a barrier of earth between the
sewage sludge and vectors. The soil quickly removes
water from the sludge, which reduces the mobility and
odor of the sewage  sludge. Odor is  usually present at
the site during the injection process, but it quickly dissi-
pates when injection is completed (U.S. EPA, 1992).

Potential for odors also can be reduced or eliminated by:

• Incorporation of sludge as soon  as possible  after
  delivery and application to the site.

• Daily  cleaning  (or  more  frequently,  if needed)  of
  trucks, tanks, and other equipment.

• Avoiding sludge application to waterlogged soils or
  when other soil or  slope conditions would cause
  ponding or poor drainage of the applied sludge.

• Use of proper sludge application rates for application
  site conditions.

• Avoiding or limiting the   construction and  use  of
  sludge storage  facilities at the land application site,
  or designing and locating the sludge storage facilities
  in a way that prevents odor problems.  Experience
  has shown that sludge  storage facilities are a major
  cause of odor problems at land application sites.

• Isolation of the  sludge application site from residen-
  tial, commercial, and other public access areas.

Prevention of odor problems by using the recommenda-
tions listed above is important for public acceptance of
land application programs. If odor problems resulting in
citizen complaints do  occur, the project management
should have established procedures  for correcting the
problems and responding to complaints.
15.3.2   Spillage

All trucks involved  in  handling  sludge  on highways
should be designed to  prevent sludge spillage.  Liquid
sludge tankers generally do not present a problem. For
sludge slurries (10 to 18 percent solids), specially de-
signed haul vehicles with anti-spill baffles have been
effectively employed. Sludge spillage on-site can gener-
ally be best controlled using vacuum transfer systems.
If mechanical or human errors during transport or at the
application site do result in spillage of sludge, cleanup
procedures should be employed as soon  as possible.

Major spills  may result from traffic accidents, faulty or
poorly maintained equipment, or inadequate storage
facilities (Elliott et al., 1990). Major spills can be mini-
mized by properly training drivers and applicators; locat-
ing  application   sites  along  well maintained  roads;
providing adequate  storage for equipment  so that  it is
not exposed to bad weather conditions; properly design-
ing storage  facilities; and  regularly maintaining equip-
ment (Elliott et al., 1990).

Small, minor spills should also be avoided.  Minor spills
can occur as hoses are uncoupled  between a  nurse
truck and a  tank wagon, when equipment is overfilled,
when  the seal on a dumptruck tailgate wears out, and
numerous other  situations  (Elliott et al., 1990).  Minor
spills can be prevented with proper equipment mainte-
nance and careful material handling.

15.3.3   Mud

Tracking of mud from the field onto highways, as well as
field or access road  rutting by sludge transport or appli-
cator equipment  are nuisance concerns.  Mud can be a
particularly severe problem in areas with poor drainage,
but can occur at any site during periods of heavy rain or
spring thaws. Choose all-weather site access roads or
modify access roads with gravel  or other acceptable
weight-bearing material.  To minimize problems with
mud, the following management steps should be con-
sidered:

• Use vehicles with flotation tires.

• Use vehicles with smaller capacity, or temporarily re-
  duce volume of sludge being hauled.

• Remove mud tracked on roads.

• Wash down vehicles regularly when moving between
  sites to prevent tracking of mud on highways. This
  process also  improves  the public image of sludge
  hauling and handling systems and enhances contin-
  ued community acceptance.

15.3.4   Dust

Dust movement  off-site  increases with wind  or move-
ments of haul vehicles and equipment. To minimize dust
                                                  183

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generation, access roads may need to be  graveled,
paved, oiled, or watered.

15.3.5  Noise

Noise levels from use of heavy equipment (e.g., tractors,
subsurface injector vehicles)  at land application sites
may be a concern in some communities. In agricultural
areas, noise (and dust) should generally be  no worse
than  expected  from normal  farming  operations  and
should not create problems. In more populated areas,
use of buffer zones and vegetative screening (trees and
shrubs  around  the site)  may be needed to mitigate
public impact.

15.3.6  Road Maintenance

The breakup of roads by heavy sludge hauling vehicles
can be a problem, particularly in northern climates, and
can result  in public  complaints.  Project management
should have provisions to repair roads or a fund avail-
able to help finance cost  of road  repairs resulting from
project activity.

15.3.7  Selection of Haul Routes

Routes for sludge  haul trucks should avoid residential
areas to prevent nuisance caused by truck and air brake
noise, dangers to  children, and  complaints  regarding
frequency of hauling.

15.4 Safety Concerns

Managers of sewage sludge land application systems
have an obligation to maintain safe and secure working
conditions for all personnel  and residents, including in-
dividuals working directly with the sludge (e.g., POTW
personnel,  sludge  haulers,  farmers, heavy equipment
operators), as well  as persons living  or working  near an
application site or  visiting the site. It is  important that
safety rules are written, published, distributed to all em-
ployees, and enforced. A safety training  program, cov-
ering  all aspects of site safety and  proper equipment
operation, as required by OSHA, should be conducted
on a regular basis.

Safety features should be incorporated into every facet
of the land  application system design. Certain practices
should  be  followed  routinely to  assure safe working
conditions. The official operations  program should con-
tain specific safety guidelines for each operation and
feature of the system.

The operation of sludge hauling and application equip-
ment  presents the  greatest  potential  for accidents.
Regular equipment maintenance and operational safety
checks should be conducted.

The stability of the soil can present a potential safety
problem, particularly when  operating large equipment.
Vehicles should approach disturbed or regraded sites,
muddy  areas, or steep slopes cautiously to prevent
tipping or loss of control.

As with any construction activity, safety methods should
be implemented in accordance with Occupational Safety
and  Health Administration  (OSHA) guidelines.  In ac-
cordance with OSHA guidelines, the following precau-
tions and  procedures  should be employed for sludge
land application projects:

• A safety manual should be available for use by em-
  ployees, and all employees should  be  trained in all
  safety procedures.

• Appropriate personal safety devices, such as hard-
  hats, gloves, safety glasses, and  footwear, should be
  provided to employees.

• Appropriate safety devices, such as rollbars,  seat-
  belts, audible reverse warning devices, and fire ex-
  tinguishers, should be  provided  on equipment used
  to transport, spread, or incorporate sludge.

• Fire  extinguishers should be provided for equipment
  and  buildings.

• Communications equipment should be  available on-
  site for emergency situations.

• Work areas and access roads should be well marked
  to avoid on-site vehicle mishaps.

• Adequate  traffic control should be provided to  pro-
  mote an orderly traffic  pattern to and from  the land
  application site to maintain efficient operating  condi-
  tions  and avoid traffic jams on local  highways.

• Public access to the sludge application site should
  be controlled. The extent of the control necessary will
  depend  on  the  sludge  application practice  being
  used, the time interval since sludge was last applied,
  and  other  factors  (see applicable  process design
  chapters 7 through  9). In general, public access to
  application sites should be controlled during sludge
  application operations  and for an appropriate time
  period after the sludge is applied.

15.4.1   Training

It is important for land application facilities to employ well
trained personnel. Qualified personnel can be the differ-
ence between a well organized, efficient operation and
a poor operation. New employees should not only learn
the tasks  required for their  positions,  but also under-
stand the purposes and importance of the overall land
application  operation.  Equipment should  be operated
only by fully trained and qualified operators.

A training program should be conducted for site person-
nel by  the engineer who designed  the  land application
program or someone well acquainted with the operation.
                                                  184

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Training programs should incorporate the following (Elliott
etal., 1990):

• All aspects of operation, from sludge production to
  growth of crops, should be discussed.

• Equipment  operators should fulfill licensing require-
  ments.

• Applicators should be taught to calculate application
  rates and calibrate equipment.

• Good housekeeping should  be  stressed during all
  phases of training.

15.5 Health Concerns

15.5.1   General

A discussion  of  pathogens  and vectors that may be
associated with sewage sludge is contained in Chapters
3 and 4. Although bacteria, viruses, and parasites are
generally present in sewage sludge, the requirements in
Subpart D  of the Part 503  regulation protect  public
health and the environment through requirements de-
signed to reduce the density of organisms in sewage
sludge to below detectable levels, or, through a combi-
nation of organism reduction and site restrictions, allow
the environment  to further reduce  organisms to below
detectable levels (U.S. EPA, 1992).

In addition,  research by EPA and others has shown no
significant health problems for personnel  who  are in
contact  with  sewage  sludge on  a regular basis at
POTWs or  land  application sites  (Burge  and  Marsh,
1978; Clark et al., 1980). Furthermore, epidemiological
studies have  shown no significant  health problems for
people living  or  working close to  sites receiving land
applied sewage sludge or wastewater (U.S. EPA, 1985;
Kowal, 1983;  Pahren et al., 1979).

15.5.2  Personnel Health Safeguards

It is recommended that project management  include
health safeguards for  personnel involved  with sludge
transport and handling, including:

• Provide regular typhoid and tetanus inoculations and
  poliovirus and  adenovirus vaccinations.

• Limit direct  contact with aerosols  as much as possible
  where liquid sludge application techniques are used.

• Encourage  proper personal hygiene.

• Provide annual employee health checkups.

• Record reported employee  illnesses;  if a  pattern
  (trend) of illnesses potentially associated with sludge
  pathogens develops, investigate and take appropriate
  action.
15.6 Recordkeeping and Reporting
15.6.1   General

The Part 503 regulation requires that certain records be
kept by the person who prepares sewage sludge for land
application and the person who applies sewage sludge
to the land. The regulation defines the person who pre-
pares sewage sludge as "either the person who gener-
ates sewage sludge during  the treatment of domestic
sewage in a treatment works or the person who derives
a material from sewage sludge." This definition covers
two types of operations—those that  generate sewage
sludge and those that take sewage sludge after it has
been generated and change the quality of the sewage
sludge (e.g., blend or mix it with another material) prior
to use or disposal. Any time the sewage sludge quality
(e.g., pollutant concentrations, pathogens levels, orvec-
tor attraction  characteristics) is changed, the person
responsible for the change is defined as a person who
prepares sewage sludge. Recordkeeping  requirements
for preparers and appliers of sewage sludge are sum-
marized in  Table 15-1, and specific  requirements are
discussed in Sections 15.6.2 and  15.6.3. Dewatering
sewage sludge  is not considered to be  changing the
quality of the sewage sludge.

Preparers and appliers of sewage sludge should  be
aware that failure to keep adequate records is a violation
of the Part 503 regulation and subject to administrative,
civil, and/or criminal penalty under the Clean Water Act.


15.6.2   Part 503 Recordkeeping
         Requirements for Preparers of
         Sewage Sludge

Part 503 requires the person  who prepares sewage
sludge to evaluate sewage sludge quality, maintain  re-
cords, submit compliance reports (for some preparers),
and distribute sludge quality information to subsequent
preparers and appliers who need the information to
comply with the  other requirements  of the regulation.
With respect to pollutants, the  Part 503 regulation  re-
quires the preparerto maintain records documenting the
concentration of regulated  pollutants  in the sewage
sludge. With respect to pathogens and vector attraction,
the records must describe how the pathogen and vector
attraction reduction requirements were met (if one of the
vector attraction reduction options 1 through 8 was met,
see Chapter 3) and include a signed certification of their
achievement. The regulation specifies that records be
maintained for a period of at least 5 years.

U.S. EPA (1993b) presents a detailed discussion of the
recordkeeping responsibilities for preparers of sewage
sludge under Part 503.
                                                 185

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Table 15-1.  Part 503 Recordkeeping and Reporting Requirements (U.S. EPA, 1994a)
Type of Sewage
Sludge
                                 Records That Must Be Kept
                                                                          Person Responsible
                                                                          for Recordkeeping
                                                                         Preparer
Applier
Records That Must
  Be Reported3
EQ Sewage Sludge
                       Pollutant concentrations
                       Pathogen reduction certification and description
                       Vector attraction reduction certification and description
PC Sewage Sludge
CPLR Sewage Sludge
APLR Sewage Sludge
                       Pollutant concentrations                                 /
                       Management practice certification and description
                       Site restriction certification and description (where
                       Class B pathogen requirements are met)
                       Pathogen reduction certification and description              /
                       Vector attraction reduction certification and description         /

                       Pollutant concentrations                                 /
                       Management practice certification and description
                       Site restriction certification and description (if Class
                       B pathogen requirements are met)
                       Pathogen reduction certification and description              /
                       Vector attraction reduction certification and description         /
                       Other information:
                       -  Certification and description of information
                         gathered (information from the previous applier,
                         landowner, or permitting authority regarding the
                         existing cumulative pollutant load at the site from
                         previous sewage sludge applications)
                       -  Site location
                       -  Number of hectares
                       -  Amount of sewage sludge applied
                       -  Cumulative amount of pollutant applied (including
                         previous amounts)
                       -  Date of application

                       Pollutant concentrations                                 /
                       Management practice certification and description            /
                       Pathogen reduction certification and description              /
                       Vector attraction reduction certification and description         /
                       The AWSAR for the sewage sludge                        /
                                                                                        /b
                   /
                   /c

                   /
                   /c

                   /d
                                                                                                          /d

                                                                                                          /d
a Reporting responsibilities are only for treatment works with a design flow rate equal to or greater than 1  mgd, treatment works that
 serve a population of 10,000 or greater, and Class I treatment works.
3 The preparer certifies and describes vector attraction reduction methods other than injection and incorporation of sewage sludge into the soil.
 The applier certifies and describes injection or incorporation of sewage sludge into the soil.
: Records that certify and describe injection or incorporation of sewage sludge into the soil do not have to be reported.
^ Some of this information has to be reported when 90 percent or more of any of the CPLRs is reached at a site, if the applier is a Class I treatment
 works, a treatment works serving a population of 10,000 or more, or a treatment works with a 1 mgd or greater design flow.
15.6.2.1   Records of Pollutant Concentrations

The preparer is responsible for documenting the sam-
pling and analysis of pollutant concentrations in sewage
sludge; to demonstrate this, the records outlined in Fig-
ure 15-4 should be maintained.

When sewage sludge or material derived from sewage
sludge that is  destined  for land  application  does  not
meet the  pollutant  concentration limits  in  Chapter 3,
Table  3-4,  additional records  must  be kept to demon-
strate  compliance with  either the cumulative pollutant
loading rate limits or the annual  pollutant loading rate
limits outlined  in Table 3-4, as appropriate.

If the  preparer plans to  sell or give away the sewage
sludge in a bag or other container for application to the
land, he or she must develop and  retain the following
                                                            additional records (if the sewage sludge does not meet
                                                            "exceptional quality" criteria, as discussed in Chapter 3):

                                                            • Calculation  of an  annual  whole sludge application
                                                              rate (AWSAR) that will not exceed the annual pollut-
                                                              ant loading  rate limits in Chapter 3, Table 3-4.

                                                            • A copy of the label or information sheet provided to
                                                              persons who will land apply the sewage sludge.

                                                            15.6.2.2   Certification of Pathogen Reduction

                                                            The Part 503 regulation requires  the  maintenance of
                                                            records that include a certification  by the preparer that
                                                            the pathogen requirements were met and a description
                                                            of how compliance was achieved. The general certifica-
                                                            tion statement that must be used is provided in Figure
                                                            15-5. Usually, the description should explain the treat-
                                                            ment process for pathogen reduction and be supported
                                                        186

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by analytical results for pathogens and indicator organ-
isms and log books documenting operational parame-
ters for sludge treatment units. The following paragraphs
discuss the types of records used to demonstrate com-
pliance for each pathogen reduction alternative. A discus-
sion  of Class A and Class  B alternatives is provided in
Chapters.

Class  A Alternatives

Table 15-2 summarizes the  recordkeeping requirements
for each Class A alternative.

Alternative 1: Thermally Treated Sewage Sludge

This alternative requires that sludge treatment units be
operated to maintain the sludge at a specific tempera-
ture for a specific period  of time. To demonstrate com-
pliance with  the operational  parameters, the preparer
should  check the  temperature in the sludge treatment
unit(s) and record  it to demonstrate that the sludge was
   Parameters: Pollutant Concentrations (metals), Salmonella
   sp. or Fecal Coliform bacteria, Percent Solids, Enteric
   Viruses and Viable Helminth Ova (for certain  pathogen
   reduction alternatives)

   • Sampling Records. Date and time of sample collection,
    sampling location, sample type, sample volume, name of
    sampler, type of sample container, and methods of
    preservation, including cooling.
   • Analytical Records. Date and time of sample analysis,
    name of analyst, and analytical methods used.
   • Raw Data. Laboratory bench sheets indicating all raw data
    used in the analyses and the calculation of results (unless
    a contract laboratory performed the analyses for the
    preparer).
   • Name  of contract laboratory, if applicable.

   • QA/QC. Sampling and analytical quality assurance/quality
    control (QA/QC) procedures.

   • Analytical results expressed in dry weight.
Figure 15-4.  Required Records for Preparers of Sewage Sludge
            to Document Sampling and Analysis  (U.S. EPA,
            1993b).
held at a constant temperature for the required number
of days. If the temperature is not recorded continuously,
it should be checked and  recorded during each work
shift or at least twice a day. The objective is to  obtain
temperature readings that are representative of the tem-
perature maintained throughout the treatment process.

In addition, records should document the detention time
of the sludge in the treatment unit, the daily input  of
sludge, and the withdrawal of supernatant  and proc-
essed sludge from the treatment unit. The size (gallons)
of the unit(s) should also be documented.

This alternative also requires documentation of monitor-
ing for either Salmonella sp. bacteria or fecal coliform in
sewage  sludge at the  time  of  use.  To this end, the
preparer should keep the records outlined in Figure 15-4
documenting sampling and analysis.

Alternative 2: Sewage Sludge Treated in a High pH-
High Temperature Process

Alternative 2, like Alternative I, requires the analysis of
sludge quality and the evaluation of operating parame-
ters. As with Alternative 1, the sludge must be monitored
for either Salmonella sp. bacteria or fecal coliform.  Use
of this alternative requires  that operating logs be kept
that document  pH,  temperature,  residence  time,  and
percent total  solids.  The temperature  of the  sewage
sludge should be checked and recorded to document it
is above 52°C for 12 continuous  hours during the re-
quired 72-hour holding period. If the temperature is not
continuously  monitored, it  should  be checked  hourly
when feasible. At a  minimum, it should be recorded at
the beginning, middle,  and end of treatment.  Similarly,
the pH of the  sewage sludge should be  recorded at the
beginning, middle, and end of the required 72-hour hold-
ing period. The percent total solids also should be de-
termined for each batch. The preparer must keep the
records outlined in Figure 15-4 to document that sludge
was analyzed at the time of use or disposal for either
Salmonella sp.  bacteria or fecal  coliform  at  the fre-
quency specified in Chapter 3, Table 3-15.
   "I certify under penalty of law, that the [insert each of the following requirements that are met: Class A or Class B pathogen
   requirements, vector attraction reduction requirements, management practices, site restrictions, requirements to obtain information]'m
   [insert the appropriate section number/s in Part 503 for each requirement met] have/have not been met. This determination has been
   made under my direction and supervision in accordance with the system designed to ensure that qualified personnel properly gather
   and evaluate the information used to determine that the requirements have been met. I am aware that there are significant penalties
   for false certification, including the possibility of fine and imprisonment."
   Signature
                                                                         Date
   Note: The exact language of the certification should be tailored to accurately describe which requirements have been met and which
        have not been met, when applicable.
Figure 15-5.  Certification statement required for recordkeeping.
                                                     187

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Table 15-2.  Recordkeeping Recommendations for Class A Pathogen Reduction Alternatives (U.S. EPA, 1993b)
Alternative Al— Time and Temperature
• Analytical results for density of Salmonella sp. bacteria or fecal coliform (most probable number)
• Sludge temperature (either continuous chart or two readings per day, at least one per shift)
• Time (days, hours, minutes) temperature maintained
Alternative A2— Alkaline Treatment
• Analytical results for density of Salmonella sp. bacteria or fecal coliform (most probable number)
• Sludge pH (beginning, middle, and end of treatment)
• Time (hours) pH maintained above 12 (at least 72 hours)
• Sludge temperature (beginning, middle, and end of treatment and hourly to demonstrate 12 hours above 52°C)
• Percent solids in sludge after drying (at least 50 percent)
Alternative A3— Analysis and Operation
• Analytical results for density of Salmonella sp. bacteria or fecal coliform (most probable number)
• Analytical results for density of enteric viruses (pkque forming unit/4 grams total solids) prior to pathogen
reduction and, when appropriate, after treatment
• Analytical results for density of viable helminth ova (number/4 grams total solids) prior to pathogen reduction
and, when appropriate, after treatment
• Values or ranges of values for operating parameters to indicate consistent pathogen reduction treatment
Alternative A4— Analysis Only
• Analytical results for density of Salmonella sp. bacteria or fecal coliform (most probable number)
• Analytical results for density of enteric viruses (plaque forming unit/4 grams total solids)
• Analytical results for density of viable helminth ova (number /4 grams total solids)
Alternative AS— Processes to Further Reduce Pathogen
• Heat Drying
- Analytical results for density of Salmonella sp.
bacteria or fecal coliform (most probable number)
- Moisture content of dried sludge < 10 percent
- Logs documenting temperature of sludge particles
or wet bulb temperature of exit gas exceeding 80 °C
(either continuous chart or two readings per day, at
least one per shift)
• Thermophilic Aerobic Digestion
- Analytical results for density of Salmonella sp.
bacteria or fecal coh'form (most probable number)
- Logs documenting temperature maintained at 55-
60 C for 10 days (either continuous chart or two
readings per day, at least one per shift)
• Heat Treatment
- Analytical results for density of Salmonella sp.
bacteria or fecal coliform (most probable number)
- Logs documenting sludge heated to temperatures
greater than 180°C for 30 minutes (either
continuous chart or three readings at 15 minute
intervals)
• Pasteurization
- Analytical results for density of Salmonella sp.
bacteria or fecal coliform (most probable number)
- Temperature maintained at or above 70° C for at
least 30 minutes (either continuous chart or two
readings per day, at least one per shift)
s{PFRP)
• Composting
- Analytical results for density of Salmonella sp.
bacteria or fecal coliform (most probable number)
- Description of composting method
- Logs documenting temperature maintained at or
above 55 °C for 3 days if within vessel or static
aerated pile composting method (either continuous
chart or two readings per day, at least one per
shift)
- Logs documenting temperature maintained at or
above 55°C for 15 days if windrow compost
method (minimum of two readings per day, at least
one per shift)
- Logs documenting compost pile turned at least five
times per day, if windrow compost method
• Gamma Ray Irradiation
- Analytical results for density of Salmonella sp.
bacteria or fecal coliform (most probable number)
- Gamma ray isotope used
- Gamma ray dosage at least 1 .0 megarad
- Ambient room temperature log (either continuous
chart or two readings per day, at least one per
shift)
• Beta Ray Irradiation
- Analytical results for density of Salmonella sp.
bacteria or fecal coliform (most probable number)
- Beta ray dosage at least 1 .0 megarad
- Ambient room temperature log (either continuous
chart or two readings, at least one per shift)
Alternative A6— PFRP Equivalent
• Operating parameters or pathogen levels as necessary to demonstrate equivalency to the PFRP
• Analytical results for density of Salmonella sp. bacteria or fecal coh'form (most probable number)
                                                       188

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       Fecal Coliform/Safmone/te sp. Bacteria
                                    AND
                                                   Enteric Viruses
                                                                       AND
                                                                                   Viable Helminth Ova


Sample sludge after pathogen
reduction treatment and at the time
of use or disposal and analyze for
either fecal coliform OR Salmonella
sp. bacteria.
S
Fecal Coliform
analytical results
show density less
than 1,000 MPN"
per gram of total
solids (DW).


Sludge is Class A
_ for bacteria until
next monitoring
interval.
OR

^X


Salmonella sp.
Bacteria
analytical results
show density less
than 3 MPN per
four grams of total
solids.
|
Sludge is Class A
for bacteria until
next monitoring
interval.

                                              Sample sludge before pathogen
                                            reduction treatment and analyze for
                                                  enteric viruses.
                                                      OR
Analytical results
show density less
than 1 PFU+ per
4 grams of total
solids.

Analytical results
show density
greater than or
equal to 1 PFU
per 4 grams of
total solids.
                                                              E
Sludge is Class A
for enteric viruses
until next
monitoring
interval.



Begin pathogen
reduction «
treatment and
record operating
parameters.
                       Sample sludge before pathogen
                      reduction treatment and analyze for
                           viable helminth ova.
                                                                                         OR
Analytical results
show density less
than 1 per 4
grams of total
solids.

Analytical results
show density
greater than or
equal to 1 per 4
grams of total
solids.
                                        E
   * MPN = Most probable number
   t PFU = Plaque-forming unit
Sludge is Class A
for viable
helminth ova until
next monitoring
interval.





Begin pathogen
reduction
treatment and
record operating
parameters.
\





F
Monitor sludge
again after
pathogen
reduction
treatment.
                                                      After demonstration, enteric
                                                      viruses no longer need to be
                                                        monitored if records
                                                     demonstrate that the operating
                                                      parameters of the pathogen
                                                       reduction treatment are
                                                      consistent with parameters
                                                      used in the demonstration.
                                After demonstration, enteric
                                viruses no longer need to be
                                  monitored if records
                               demonstrate that the operating
                                parameters of the pathogen
                                 reduction treatment are
                                consistent with parameters
                                used in the demonstration.
Figure 15-6.  Pathogen reduction alternative 3—analysis and operation (U.S. EPA, 1993b).
Alternative 3: Sewage Sludge Treated in Other
Processes

Alternative 3, like the first two alternatives under Class
A, utilizes a combination of sludge quality analysis and
documentation of operating parameters. In addition to
monitoring for either fecal coliform  or Salmonella sp.
bacteria under this alternative, preparers must monitor
for enteric viruses  and  viable  helminth  ova.  If  the
preparer follows the steps outlined in Figure 15-6, he or
she can substitute documentation of operating parame-
ters for periodic  analysis of enteric  viruses and viable
helminth ova (U.S. EPA, 1993b). Regardless of how the
preparer demonstrates compliance with the enteric virus
and viable helminth  ova requirement, the final sludge
must  be sampled and  analyzed  at the time of use for
either fecal coliform or Salmonella sp. bacteria accord-
ing to the frequency specified  in Chapter 3, Table 3-15.

The preparer must maintain the records outlined in Fig-
ure 15-4  to  document sludge sampling  and analysis
before and after pathogen reduction treatment.  These
records also must define the values used for operating
parameters  between the before- and after-treatment
sludge analyses. If operating parameters are substituted
for periodic sludge monitoring, records must also docu-
ment that these values are maintained consistently. The
specific operating parameters that must be recorded to
demonstrate compliance  may  vary depending on  the
particular pathogen reduction process used (e.g., com-
posting, pasteurization).

Alternative 4: Sewage Sludge  Treated in Unknown
Processes

Alternative  4 relies solely on the analysis of sewage
sludge for pathogens (i.e., Salmonella sp. bacteria,  en-
teric viruses, and  viable  helminth ova) and indicator
organisms (i.e., fecal coliform) to demonstrate pathogen
reduction. Records  must document that these parame-
ters  were sampled  and analyzed at least  as often as
specified  in  the Part 503 regulation  (see  Chapter 3,
                                                      189

-------
Table 3-15). The preparer should keep the records out-
lined in Figure 15-4 for each sampling event.

Alternative 5:  Use of a Process to Further Reduce
Pathogens (PFRP)

This alternative requires a combination of sludge analy-
sis for either fecal coliform or Salmonella sp.  bacteria
and documentation of operating parameters. The spe-
cific operating parameters that must be evaluated are
defined by the particular PFRPs. Table 15-2 outlines the
seven  different PFRPs and the specific operating pa-
rameters for each. Records should include a descrip-
tion of the pathogen reduction process, documentation
of sampling and analysis of the sludge for fecal coliform
or Salmonella sp. bacteria  (see Figure 15-4),  and log
books documenting  proper operation of pathogen re-
duction processes.

Alternative 6: Use of a Process Equivalent to a PFRP

Alternative 6  requires a combination of sludge analysis
and documentation of operating parameters. As with the
other Class A alternatives, the sludge must be monitored
for either fecal coliform or Salmonella sp.  bacteria. Al-
ternative 6 requires sewage sludge to be treated in  a
process  equivalent to a PFRP, as determined by the
permitting authority. The permitting authority should in-
dicate appropriate information that has to be kept. The
records could include temperature in sludge treatment
units, retention time, pH, solids or moisture content, and
dissolved oxygen (DO) concentration.
Table 15-3.  Recordkeeping Requirements for Class B Pathogen Reduction Alternatives (U.S. EPA, 1993b)
    Alternative Bl—Fecal Coliform Count
       Number of samples collected during each monitoring event

       Analytical results for density of fecal coliform for each sample collected
   Alternative B2—Processes to Significantly Reduce Pathogens (PSRP)
   •  Aerobic Digestion
      -  Dissolved oxygen concentration
      -  Mean residence time of sludge in digester
      -  Logs showing temperature was maintained for sufficient period of time (ranging from 60 days at 15°C to
         40 days at 20°C) (continuous charts or two readings per day, at least one per shift)

   •  Air Drying
      -  Description of drying bed design
      -  Drying time in days
      -  Daily average ambient temperature


   •  Anaerobic Digestion
      -  Mean residence time of sludge in digester (between 15 days at 35"C to 55°C and 60 days at 20DC)
      -  Temperature logs of sludge in digester (continuous charts or two readings per day, at least one per shift)


   •   Composting
      -   Description of composting method
      -   Daily temperature logs documenting sludge maintained at 40° C for 5 days (either continuous chart or two
         readings per day, at least one per shift)
      -   Hourly readings showing temperature exceeded 55°C for 4 consecutive hours


   •   Lime Stabilization
      -   pH of sludge immediately and then 2 hours after addition of lime
  Alternative B3—PSRP Equmdent
  •  Operating parameters or pathogen levels as necessary to demonstrate equivalency to PSRP
                                                  190

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Class B Alternatives

Table 15-3 summarizes the recordkeeping requirements
for each Class B alternative.

Alternative 1: Monitoring of Fecal Conform

Alternative 1 requires the analysis of the sewage sludge
for fecal coliform. In addition to maintaining the records
outlined in Figure 15-4 to document compliance with the
fecal coliform  level, the  preparer should maintain the
calculation of the geometric mean of the seven samples
analyzed under this alternative (see Alternative  1 in
Chapter 3).

Alternative 2: Use of a Process to Significantly Reduce
Pathogens (PSRP)

This alternative  requires  a  combination of  sewage
sludge analysis and documentation of operating pa-
rameters. As with  the PFRP alternative, the  specific
operating parameters that  must be evaluated vary de-
pending on the sludge treatment process used, as listed
in Table 15-3.  Records should  include a description of
the  pathogen reduction process and log books docu-
menting regular and frequent evaluations of the operat-
ing  parameters.

Alternative 3: Use of a Process Equivalent to a PSRP

Alternative 3 requires sewage sludge to be treated in a
process equivalent to a  PSRP, as determined by the
permitting authority.  The  permitting authority  should
have specified the  appropriate records to demonstrate
compliance with this alternative. The records could in-
clude temperature  in sludge  treatment units, retention
time, pH, solids or moisture content, and DO concentra-
tion.

15.6.2.3   Records of Vector Attraction Reduction

When sewage sludge is  land  applied, the Part  503
regulation requires a certification (see Figure 15-5) that
the  vector attraction reduction  requirements were  met
and  a description  of how these requirements were
achieved. The description should be supported by docu-
mentation of process controls for treatment processes
that achieve vector attraction  reduction.  As with the
pollutant  and  pathogen  records,  this documentation
must be kept for 5 years.

There are 10 options to comply with the vector attraction
reduction requirements for land application. The  first
eight apply to the sewage sludge and are performed by
the  preparer (the final two are met at the land application
site). These eight options are referred to as the sludge
processing  options and involve sludge treatment to re-
duce  vector attraction characteristics. They are  per-
formed  by  preparers during  or  immediately  after
pathogen reduction. Each  of these processing options
is discussed in Chapter 3; the related records required
are described below.

Option 1: Reduction in Volatile Solids Content

Under this option the preparer must demonstrate that
the volatile solid concentrations in sewage sludge are
reduced by 38 percent between the raw sludge and the
sewage sludge that is used or disposed. The preparer
needs to maintain records on the volatile solids content
(mg/kg) of the raw sludge and the sewage sludge that
is used or disposed, and the calculation of volatile solids
reduction.  While  most  preparers  evaluate these  pa-
rameters regularly to document constant process opera-
tion, records must show that volatile solids reduction was
evaluated at least as frequently as specified in Table 3-15
in Chapter 3.

Option 2  and 3: Additional Digestion  of Anaerobi-
cally and  Aerobically Digested Sewage Sludge

Options 2 and 3 are methods to demonstrate that vector
attraction reduction is achieved even though 38 percent
volatile solids reduction was not attained (as required
under Option 1). The following records demonstrate that
options 2 and 3 are met:

• A  description  of the bench-scale  digester and its
  operation.

• The time (days) that the  previously digested  sludge
  sample  was  further digested in  the  bench-scale
  digester.

• The temperature (degrees Celsius) maintained in the
  bench-scale digester for the time (days) the sample
  was being further digested; the temperature  should
  either be recorded continuously  or  it should be
  checked and recorded during each work shift or dur-
  ing at least two well-spaced intervals during each day.

• Volatile solids concentration of the sewage sludge in
  mg/kg before and after bench-scale digestion.

Option 4: Specific Oxygen Uptake Rate (SOUR) for
Aerobically Digested Sewage Sludge

The  preparer should perform the SOUR test and record
the following information to demonstrate compliance un-
der this option:

• Dissolved Oxygen (DO) readings of the sludge taken
  at 1-minute intervals over a 15-minute period  or until
  the DO  is reduced to  1  mg/L, and the  average  DO
  value used in the SOUR  calculation.

• Calibration  records for the DO meter.

• Total solids determination for the sludge in g/L.

• Temperature (degrees Celsius)  taken  at the begin-
  ning and end of the procedure.
                                                  191

-------
• Temperature correction to 20°C, if other temperatures
  are used.

• Calculation of SOUR using the following equation:
SOUR =
              ,.     ,      .   ,  .DO mg/L
oxygen consumption rate per minute (	r-2—)

             total solids (g/L)
(60 min/hour)
While most preparers evaluate this parameter regularly
to document constant process operation, the records
must demonstrate that the SOUR was evaluated at least
as frequently as specified in Chapter 3, Table 3-15.

Option 5: Aerobic Processes at Greater Than 40°C

Under this option, the preparer should record the follow-
ing information to demonstrate compliance:

• Sludge residence time.

• Temperature (degrees Celsius) of the sewage sludge;
  the temperature should either be recorded continu-
  ously or checked and recorded at least once per work
  shift or at least twice a day over a 14 day period.

Option 6: Addition of Alkali Material

The preparer should maintain the  following records to
document alkaline treatment under this option:

• pH (standard units) recorded  at least at 0-, 2-, and
  24-hour intervals of treatment.

• Duration of time (hours) that pH is maintained at or
  above specified minimum levels.

• Amount (pounds or gallons) of alkali  material added.

• Amount of sludge treated (e.g., gallons, kilograms).

Options 7 and 8: Moisture Reduction

Under these options, the preparer should determine
percent total solids for each batch of sludge and keep
the following records to demonstrate compliance:

• Results  of solids analysis of sewage sludge prior to
  mixing with other material (as dry weight) expressed
  as percent of final sludge.

• Presence of unstabilized solids generated during  pri-
  mary treatment.

Records should demonstrate that  the  analysis of per-
cent total solids was performed at least  as frequently as
specified in Chapters, Table 3-15.

15.6.3 Part 503 Requirements for Appliers of
        Sewage Sludge

For  Part  503 requirements for appliers of sewage
sludge, see the Land Application of Sewage Sludge—
A Guide for Land Appliers on the Recordkeeping and
Reporting Requirements of the Federal Standards for
the Use and Disposal of Sewage Sludge Management
in 40 CFR Part 503 (U.S. EPA, 1994b).

15.6.4   Notification Requirements for Preparers
         and Appliers of Sewage Sludge

When sewage sludge is prepared for land application in
bulk form or sold or given away  in a bag or other
container for application to the land, the preparer must
inform the applier of the  sewage  sludge quality.  The
notification requirements are different  if the sludge is
sold or given away in a bag or other container rather
than being land applied in bulk, as described below. The
notice and necessary information requirement does not
apply when the sewage sludge or the material derived
from sewage sludge meets the "exceptional quality cri-
teria" discussed in Chapter 3.

15.6.4.1   Bulk Sewage Sludge

When bulk sewage sludge that is not "exceptional qual-
ity" is prepared for land application, both the preparer
and the land  applier have notification requirements. The
preparer must provide  the following sewage  sludge
quality information to the land applier:

• Pollutant concentrations.

• Nitrogen concentration  (TKN, ammonia,  and  nitrate
  nitrogen).

• Pathogen reduction level  achieved (Class A or Class B).

• Vector attraction reduction option used (Options 1-8).

• Required management practices and recordkeeping.

The land applier must have this information to  comply
with the Part 503 regulation when land  applying the
sewage sludge. If the pollutants do not  meet the pollut-
ant concentration limits in Chapter 3, Table 3-4, then the
land applier must track the cumulative pollutant loading
rates. If a Class B pathogen reduction  alternative  was
used, then the land  applier must ensure that the site
restrictions are met. If the  preparer did not perform one
of the sludge processing vector attraction reduction op-
tions (Options  1-8), then the land applier must perform
one of the sludge management vector attraction reduc-
tion options (Options 9-10).

The land applier is also responsible for providing the
land owner or  lease holder of the  land  notice and nec-
essary information to  comply with the Part 503 require-
ments. For example, if the sludge met Class B pathogen
reduction requirements, then the  land  owner or lease
holder must be informed of the associated site use and
access restrictions. If the land applier is tracking the
cumulative pollutant  loading rates  (see  above para-
graph), he or she should document and provide the  land
owner or lease holder with the following information:

• Location of land application site.
                                                 192

-------
 • Date  bulk sewage sludge  was applied.

 • Time  bulk sewage sludge was  applied if vector at-
   traction  reduction option 9 or 10 was used.
                                                              Number of hectares where the sewage sludge was
                                                              applied.

                                                              Amount of bulk sewage sludge applied.
    B.
    C.
                                 Part n-To Be Complete^ fay tAHPAPPLEERS of Sewage Sludge
                                                                                                                   J
    A.    If the pollutant levels in the sewage sludge do not meet the pollutant concentration limits in Table 3, then the land applier must
          record and retain the following information which should be given to the land owner.
          1.    Location of land application site.
          2.    Number of hectares where the sludge was applied.

          3.    Date and time bulk sewage sludge was applied	

          4.    Amount of bulk sludge applied	
          5.    Record the amount of each metal and nitrogen applied in pounds per acre or kilogram per hectare.
iwt*

Arunle

Ccdmitxft

Ghromtam

Coppn-

Ltui

Mttwty

Molybdenum

Nklttt

Selenium

Zinc

Ntootto

If a Class B pathogen reduction alternative was used (see Part I), then the following site restrictions must be met.  Please check the
boxes if any of the site restrictions apply.

1 .    Food crops that may touch the sewage sludge/soil mixture cannot be harvested before the end of the following waiting
      period:

      EH  a.  If harvested parts  are totally above the land, wait to harvest for 14 months after the application of sludge.

      EH  b.  If harvested parts  are below the land surface and the sludge sat on top of the soil for 4 months before the field
              was plowed, wait  to harvest for 20 months after the initial application of sludge.

      EH  c.  If harvested parts  are below the land surface and the sludge was incorporated into the soil within 4 months of
              being applied, wait to harvest for 38 months after the initial application.
          2.     EH  Feed crops cannot be harvested for 30 days after application of the sludge.

          3.     EH  Animals cannot graze on the land for 30 days after application of the sludge.

          4.     EH  If harvested turf is used for a lawn or other purpose where there is a high potential for public exposure, then the turf
                    cannot be harvested for 1 year after the application of the sludge to the land.
5.    EH  Public access to land with
                                                          (parks, playgrounds, golf courses) for public exposure will be restricted
           for 1 year after the application of the sludge.

6.    EH  Public access to land with a low potential (private property, remote or restricted public lands) for public exposure
           will be restricted for 30 days after the application of the sludge.

If the preparer did not perform vector attraction reduction options (see Part I), then either option 9 or 10 must be performed by the
land applier.  Please indicate if option 9 or 10 was performed. Check appropriate box.
                Option 9—Subsurface Injection
                                           Option 10—Incorporated (plowed) into the Soil
N/A
    D.   CERTIFICATION
           I certify under penalty of low that this document and all attachments were prepared under my direction or supervision in accordance with a system
           designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who
           manage the system or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and
           belief, true, accurate, and complete.  I am aware that mere are significant penalties for submitting false information, including the possibility of fine
           and imprisonment for knowing violations.
A. Name and Official Title (type or print)
C. Signature
B. Area Code and Telephone Number
D. Date Signed
Figure 15-7.  Notice and necessary information (U.S. EPA, 1993b)
                                                               193

-------
• Cumulative amount of each pollutant (i.e., kilograms)
  applied.

The land owner or tenant may request specific informa-
tion,  such as  analytical results on sludge quality or
documentation on how sludge  management practices
are met. In general, the form in Figure 15-7 may be used
to satisfy the notification requirements of both the
preparer and the land applier.

15.6.4.2   Sewage Sludge Sold or Given Away in
          a Bag or Other Container for
          Application to the Land

When sewage sludge that does not meet the  Part 503
pollutant concentration limits is  sold or given away in a
bag or other container for application to the land, it must
be accompanied by a label or instruction sheet.  The
label  or  instruction sheet must contain the following
information:

• Name  and address of the person who prepared the
  sewage sludge.

• Statement that land application is prohibited except
  in accordance with the  instructions.

• The annual  whole  sludge application rate  that en-
  sures that none of the annual pollutant loading rates
  in Chapter 3, Table 3-4, are exceeded.

15.6.5   Notice of Interstate Transport

When bulk sewage sludge that  does not meet the "ex-
ceptional quality" criteria is going to be applied to land
outside a state in which the sludge was prepared, the
preparer is required to provide written notice to the
permitting authority for the state in which the bulk sew-
age sludge is  proposed to be applied, prior to the initial
application of the sewage sludge to a site. The written
notice must include the following information:

• Location, by either street address or latitude and lon-
  gitude, of each land application site.

• Approximate time when bulk sewage  sludge will be
  applied to the site.

• Name, address, telephone number, and National Pol-
  lutant Discharge Elimination System (NPDES) permit
  number for the person who prepares the bulk sewage
  sludge.

• Name, address, telephone number, and NPDES per-
  mit  number  for the person who will apply  the  bulk
  sewage sludge.

15.6.6   Notification by Appliers

The person who applies bulk sewage sludge subject to
the  cumulative   pollutant  loading  rates   in  Part
503.13(b)(2) to the land must provide written  notice to
the permitting authority for the state in which the bulk
sewage sludge will be applied, including:

• The location, by either street address or latitude and
  longitude, of the  land application site.

• The name, address, telephone number, and NPDES
  permit number for the person who will apply the bulk
  sewage sludge.

15.6.7   Annual Reports

Most preparers are required by Part 503 to report annu-
ally to  the permitting  authority. Annual reports cover
information and data collected during the calendar year
(January 1 to December 31). Reports on sewage sludge
quality  must include the results of monitoring pollutant
concentrations and  pathogen levels,  a description of
operating parameters for pathogen reduction and vector
attraction reduction, and certifications that pathogen and
vector attraction reductions were achieved. Permits is-
sued by EPA or a state may contain additional reporting
requirements.

15.6.7.1   Persons Responsible for Submitting
          Reports Under Part 503

Persons  responsible for reporting  annually are  de-
scribed in  the Part 503 regulation as:

• Publicly owned treatment works (POTW) with an av-
  erage design influent flow rate equal to or greater
  than  1 million gallons per day.

• POTWs serving a population of 10,000 or more.

• Class I sludge management facilities.

Class I sludge management facilities include POTWs
required to have an approved pretreatment program or
that have elected to institute  local limits, and treatment
works processing domestic  sewage that  EPA or the
state have classified as Class I because of the potential
for the use of sewage sludge  to negatively affect public
health and the environment. Reports must be submitted
to the permitting authority (either EPA or a state with an
EPA-approved sludge management  program).

15.6.7.2   Information Required in Annual Reports

The  Part  503  regulation specifies  the  information
preparers  are required to  keep in their records. This
includes background information on the generation and
use of sludge; the results of sludge quality analysis; and
a description and certification for pathogen and vector
attraction reduction requirements (see Figure 15-5).

Specific information to be contained in annual reports
include the amount of sewage sludge generated, in
metric tons expressed as a dry weight (see Appendix D
for equations to convert sludge  volume to metric tons);
the name and address of the preparer who will receive
                                                 194

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the sludge next, if applicable; and the name and address
of the land applier if different from the generator.

The reporting requirements for pollutant limits include
submission of the analytical results from monitoring pol-
lutant concentrations in  the sewage sludge.  Reports
should  include  the  results of all  analyses  performed
during the reporting period using the prescribed analyti-
cal  method(s) (see Chapter 13). Analytical results must
be  reported as  milligrams per kilogram (dry  weight).
Reports should also  indicate which analytical methods
were used, how frequently sludge was  monitored, and
the types of samples collected.

Preparers also are required to submit a certification (see
Figure 15-5) and description of how the pathogen reduc-
tion requirements were met. Adetailed description of the
pathogen reduction treatment process  should  include
the type  of process  used, standard operating proce-
dures, a schematic diagram, and should identify specific
values for all operating parameters.

Finally, preparers are required to report information regard-
ing  vector attraction reduction when one  of the sludge
processing options (Option 1-8). The report must contain
a description and certification (see Figure 15-5) that the
vector attraction reduction requirements were met.

The general certification statement that must be used by
preparers  and  appliers  (Figure  15-5)  certifies  that,
among  other things,  the  preparer or applier  and his or
her employees  are qualified to gather information and
perform tasks as required by the Part 503 rule. A person
is qualified if he or she has been sufficiently trained. The
certifier should periodically check the performance of his
or her employees to verify  that the Part 503  require-
ments are being met. The preparer is required to keep
these records for 5 years for sewage sludge  meeting
Part 503 pollutant concentration limits or annual pollut-
ant loading rate limits, and the applier is required to keep
records for the  life of the site (indefinitely) for sewage
sludge  meeting  Part 503 cumulative pollutant  loading
rate limits. These required records may be requested for
review  at  any time by the  permitting or enforcement
authority.

15.6.7.3   Submitting Annual Reports

As  of 1994, annual reports required under Part 503 are
due February 19 every year.  Annual reports  must be
submitted to the Permitting Authority, which is the EPA
Regional  Water Compliance Branch Chief until  state
sludge  management programs  are delegated the  re-
sponsibilities of the federal program.


15.7  References

When  an NTIS  number is cited  in  a  reference, that
document is available from:
   National  Technical Information Service
   5285 Port Royal Road
   Springfield, VA 22161
   703-487-4650

Surge, W. and P. Marsh. 1978. Infections, disease, hazards of land
   spreading  sewage wastes.  Journal  of Environmental Quality.
   7(1):1-9.

Clark, C. et al. 1980. Occupational hazards associated with sludge
   handling. In: Bitton, G. etal., eds. Health risks of land application.
   Ann Arbor  Science, pp. 215-244.

Elliott et al. 1990. Land application of water treatment plant sludges:
   Impact and management. American Water Works Research Foun-
   dation, Denver, CO.

Kowal, N. 1983. An overview of public  health effects. Presented at
   Workshop  on the utilization of municipal wastewater and sludge
   on land,  Denver, CO.

Pahren, H. et  al. 1979. Health risks associated with land application
   of municipal sludge. Journal of Water Pollution Control Federation,
   Vol. 51, pp. 2588-2601.

U.S. EPA. 1994a. A plain English guide to the Part 503 biosolids rule.
   EPA/832/R-93/003. Washington, D.C.

U.S. EPA. 1994b. Land application of sewage sludge—A guide for land
   appliers on the  recordkeeping and reporting requirements of the
   federal standards for the use and disposal of sewage sludge man-
   agement in  40 CFR Part 503. EPA/831/B-93/002b. Washington,  DC.

U.S. EPA. 1993a. Biosolids management handbook for small to  me-
   dium size POTWs. U.S. EPA Regions 8 and 10. (September 3).

U.S. EPA. 1993b.  Preparing sewage sludge for land application or
   surface disposal: A guide for preparers of sewage sludge on the
   monitoring, record keeping, and reporting requirements of the  fed-
   eral standards for the use or disposal of sewage sludge, 40 CFR
   Part 503. EPA/831/B-93/002a. Washington, DC.

U.S. EPA. 1992. Control of pathogens and vector attraction in sewage
   sludge. EPA/625/R-92/013. Washington, DC.

U.S. EPA. 1985. Demonstration of acceptable systems for land  dis-
   posal of sewage sludge. Cincinnati, OH. EPA/600/2-85/062. (NTIS
   PB85-208874).
                                                     195

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                                            Chapter 16
                 Cost Estimate Guidance for Land Application Systems
16.1  Introduction

This chapter provides information on estimating costs for
sewage sludge land  application systems.  The cost algo-
rithms presented are taken from ERA'S Handbook: Estimat-
ing Sludge Management Costs (U.S. EPA, 1985) and are
updated using (1994) cost indexes. The costs presented in
this chapter can be updated to later years by the reader
using the appropriate cost indexes (discussed  below). The
algorithms cover both capital costs and  annual operating
and maintenance (O&M) costs for land  application at ag-
ricultural, forest, and land reclamation sites, as well as for
transportation (truck hauling  and pipeline transport)  of
sewage sludge to land application sites  and onsite.

Certain key sludge management costs are not included in
this chapter, such as costs of sludge  storage (e.g., la-
goons, tanks, piles) and sludge treatment (e.g., stabiliza-
tion, dewatering, composting). This information must be
added to land application costs if total sludge management
costs are to be accurately represented. The reader should
refer to ERA'S 1985 cost estimation handbook cited above
for sludge treatment and storage cost information.

The cost estimation  algorithms present a logical series
of calculations using site-specific, process design, and
cost data  for deriving base  capital and base annual
operation and maintenance costs. Default  values are
provided for many calculations. Most of the algorithms
can be hand-calculated in less than 20  minutes per trial.
Design parameters  presented are "typical  values" in-
tended to  guide the user; the more  accurate design
information to which a user has access, the more accu-
rate the resulting costs.

The cost algorithms generally cover a range up to
100 million  gallons of sludge per year, which  is ap-
proximately equivalent to  a wastewater treatment
plant  of at least 50 mgd. This range  was selected to
include plants where supplemental  cost information
might be most useful.

16.1.1  Information Needed Prior to Using
        Cost Algorithms

Before using the  cost algorithms in this chapter, the
reader must obtain certain data and perform  the prelimi-
nary steps described  below;  otherwise,  the  resulting
cost estimates may be over- or underestimated.

• Develop a  sludge management process chain that
  shows the sequence of processes to be used, start-
  ing  with the raw sludge and ending with final  land
  application  practice.

• Develop  a mass balance  of  sludge  volume  and
  sludge concentration entering and leaving each proc-
  ess. This  is necessary because many of the  cost
  algorithms  in this chapter require  as input data the
  volume  and the suspended solids  content  of the
  sludge entering the  process (which often is not the
  raw sludge solids concentration). Thus, an approxi-
  mate mass balance  must first be computed to obtain
  the  sludge  volume and sludge solids concentration
  entering and leaving each process (e.g., treatment).

The volume of raw sludge usually is not the same as the
volume of final treated  sludge leaving a treatment proc-
ess, because each successive treatment  process  gen-
erally  tends to reduce  the mass and  volume of sludge.
Therefore, the mass and volume of the final treated
sludge is typically only  a fraction of the initial raw sludge
volume.  Similarly,  the  sludge   solids  concentration
changes as the  sludge proceeds through a  series  of
treatment processes. The steps involved  in performing
a mass balance are described  in EPA's 1985 cost hand-
book (U.S. EPA,  1985).

After  completing  the  mass  balance procedure, the
reader may use  the cost algorithms in this chapter  to
estimate the  base capital cost and  base  annual O&M
cost for different  land application practices.

16.1.2  Economic Variables

16.1.2.1   Use of Indices for Inflation Adjustment

Numerous estimates of the costs of facility construction,
site preparation,  and equipment purchase were devel-
oped by the authors of EPA's 1985 cost handbook (U.S.
EPA,  1985). The base year for these costs,  however,
was 1984; hence it is necessary to  adjust  these  esti-
mates to reflect 1994  price levels and costs.  For con-
struction-related  costs, the standard  index used is the
                                                 197

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Engineering News  Record Construction  Cost  Index
(ENRCCI). The ratio of the 1994 to 1984 index number
is used  here to adjust construction-related  cost items.
For equipment purchase costs, the 1984 prices have been
inflated using the Marshall and Swift Equipment Cost In-
dex (MSECI). The ratio of the 1994 to 1984 index number
is used here to adjust equipment-related cost items.

Adjustment for inflation can be  made to the following
cost algorithms using:

• The ENRCCI for total base capital costs and total base
  annual O&M costs. The ENRCCI appears weekly in
  Engineering News Record, published  by McGraw Hill,
  Inc. (Base 1994 ENRCCI index is 5,445.83.)

• The MSECI to adjust equipment costs or combined
  costs  in which equipment is the major cost compo-
  nent. MSECI is available from Chemical Engineering
  magazine. (Base 1994  MSECI index is 990.8.)

16.1.2.2   Labor Rates

The 1985 EPA cost handbook assumed an hourly wage
of $13.00 for  operators of heavy equipment which re-
quires considerable skill and training. This rate has been
inflated to 1994  levels using the ENRCCI  index, and
adjusted using a factor of 1.3 to account for non-wage
benefits paid by the employer. The effective wage rate,
therefore, is $22.97 per hour.

16.1.2.3   Cost of Diesel Fuel

Diesel fuel costs are  assumed  to average  $1.09 per
gallon, based  on average end-user prices for 1994 ob-
tained from the September 12, 1994 edition of Oil and
Gas Journal.

16.1.3   Total Base Capital Cost Estimates

Total base capital costs (TBCC) for sewage sludge land
application systems in this chapter include sludge appli-
cation vehicles, lime addition, grading, brush clearance,
facilities, and  acreage required. Costs  for engineering
design, construction supervision, legal  and  administra-
tion expenses, interest during construction, and contin-
gencies  are not included. These  non-construction costs
must be estimated and  added  to the  process TBCC
costs derived  from the cost algorithms  to estimate the
total project construction  cost.

16.1.4   Total Annual  O&M Cost Estimates

The annual O&M  costs for sewage sludge land application
in this chapter do not include costs for administration and
laboratory sampling/analysis. These costs must be esti-
mated and added to the process O&M costs derived from
the cost algorithms to obtain the total estimated annual O&M
cost. Total annual O&M costs can be 30 percent higherthan
the costs derived from the  algorithms in this chapter.
The total estimated O&M cost calculations in this chapter
also do  not include revenues generated through the sale
and/or use of sludge, composting products, or sludge by-
products (i.e., methane produced in anaerobic digestion). If
the user has information available on revenues generated
through  usage or sale, O&M costs may be decreased by
subtracting any revenues generated on an  annual basis
from the fixed annual O&M cost for that process.

16.1.5  Calculating Cost Per Dry Ton

In sludge processing, it is often desirable to express costs
in terms of annual cost per dry ton. This cost is obtained
by summing the amortized capital cost and base annual
O&M costs and dividing by the annual dry sludge solids
processed  (TDSS, as presented in Calculation #1 for ag-
ricultural, forest, and reclamation sites later in this chapter)
and then performing the following calculation:

   CPDT = (ACC + COSTOM)/TDSS

   where:
   CPDT     =  Cost per dry ton, $/ton.
   ACC       =  Annual amortized capital cost, $/yr
   COSTOM  =  Base annual O&M cost, $/yr.
   TDSS     =  Dry solids applied to land, Tons/yr.

If information on salvage values and revenues gener-
ated from sludge usage is available, it can be subtracted
from the numerator in the above equation.

16.2  Agricultural Land Application

16.2.1  General Information and
        Assumptions Made

The cost algorithms for  agricultural land application of
sewage  sludge presented below assume that the sewage
sludge application vehicles at  the application site are not
the same vehicles which transported the sludge from the
treatment plant to the  application site. In many cases,
however, the same vehicle is used to both transport sew-
age sludge and apply it to the application site. If the same
vehicle is used for sludge transport and application,  then
a zero  value should be used for the cost of the onsite
sludge application vehicle (the COSTPV factor) since the
cost of  that vehicle  has already been included in the
previous sludge hauling process.

The cost algorithms for agricultural land application below
include calculations forthe costs of land, lime addition, and
site grading. At many agricultural land application sites,
however, all or some of these costs are not applicable
to the municipality, since these factors are either unnec-
essary or paid for by the farmer. If the latter applies, a
zero value should be used in the cost algorithms, where
appropriate.
                                                 198

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Operation and maintenance (O&M) costs include labor,
diesel for the operation  of vehicles,  vehicle mainte-
nance, and site maintenance.
If the farm(s) accepting sewage sludge for agricultural
land application are numerous and widespread, an ex-
pensive and complicated sludge  distribution system
may be required.

16.2.2   Process Design and Cost Calculations
(1) Calculate dry solids applied to land per year.

  TDSS = [(SV)(8.34)(SS)(SSG)(365)]/(2,000)(100)
  where:
  TDSS
  SV
  SS

  SSG
SSG =

where:
1.42

8.34
2,000
Dry solids applied to land, Tons/yr.
Daily sludge volume, gpd.
Sludge suspended solids concentra-
tion, percent.
Sludge specific gravity, unitless. If
an input value is not available, de-
fault value can  be calculated using
the following equation:

 - SS)/100) + (SS)/(1.42)(100)]
                Assumed sludge solids specific
                gravity, unitless.
                Density of water, Ib/gal.
                Conversion factor, Ib/Ton.
(2) Sludge application area required.

  SOAR = (TDSS)/(DSAR)
  where:
  SOAR

  TDSS

  DSAR
   Farm area required for sludge appli-
   cation,  ac.
   Dry solids applied to land, Tons/yr
   (see Calculation #1  above).
   Average dry solids  application
   rate, Tons of dry solids/ac/yr.
   This value normally ranges from
   3 to 10 for typical food chain crop
   growing sites depending on crop
   grown, soil conditions,  climate,
   and other factors. Default value =
   5 Tons/ac/yr.  (See Chapter 7.)
(3) Hourly sludge application rate.

  HSV =  (SV)(365)/(DPY)(HPD)

  where:
                                           SV       =  Daily sludge volume, gpd. (See Cal-
                                                        culation #1 above.)
                                           DRY      =  Annual sludge application period,
                                                        days/yr. This value normally ranges
                                                        from  100 to 140 days/yr depending
                                                        on climate, cropping patterns, and
                                                        other factors. See Table 16-1 for
                                                        typical values. Default value = 120
                                                        days/yr.
                                           HPD      =  Daily sludge application period,
                                                        hr/day. This value normally ranges
                                                        from  5 to 8 hr/day depending on
                                                        equipment used,  proximity of appli-
                                                        cation sites, and other factors. De-
                                                        fault value = 6 hr/day.
                                        Table 16-1.  Typical Days Per Year of Food Chain Crop
                                                   Sludge Application
                                                     Geographic Region
                                                                        Typical Days/Yr
                                                                      of Sludge Application
                                                      Northern U.S.

                                                      Central U.S.

                                                      Sunbelt States
                                                                             100

                                                                             120

                                                                             140
                                      (4) Capacity of onsite mobile sludge application vehicles.

                                      It is assumed that the sludge has already been trans-
                                      ported to the private farm land application site by a
                                      process  such as a large-haul vehicle,  etc. The onsite
                                      mobile application vehicles accept the sludge from the
                                      transport vehicle, pipeline, or onsite storage facility, and
                                      proceed  to the  sludge application  area to apply  the
                                      sludge. Typical onsite mobile sludge application vehi-
                                      cles at farm sites have capacities ranging from 1,600 to
                                      4,000  gal, in the following increments: 1,600,  2,200,
                                      3,200, and 4,000 gal.

                                      (4a) Capacity and number of onsite mobile sludge ap-
                                      plication  vehicles.

                                      The capacity and number of onsite mobile sludge appli-
                                      cation vehicles required is determined by comparing the
                                      hourly sludge volume, (HSV), with the vehicle sludge
                                      handling rate, (VHRCAP),  as shown in Table 16-2.

                                      Above 26,000 gal/hr, the number  of 4,000-gal capacity
                                      vehicles  required is calculated by:

                                        NOV = HSV/6,545 (round to the next highest integer)
                                           where:
                                           NOV

                                           HSV
   HSV
=  Hourly sludge application rate, gal/hr.
                                                  =   Number of onsite sludge application
                                                      vehicles.
                                                  =   Hourly sludge application rate,
                                                      gal/hr (see Calculation #3).
                                                  199

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Table 16-2.  Capacity and Number of Onsite Mobile Sludge
          Application Vehicles Required
                                         VHRCAP = [(CAP)(60)(0.9)]/(CT)
Hourly Sludge
Application
Rate (HSV)
HSV (gal/hr)
0-
3,456 -
4,243 -
5,574 -
6,545 -
8,500 -
11,200 -
13,100 -
19,600-
3,456
4,243
5,574
6,545
8,500
11,200
13,100
19,600
26,000
Vehicle Number of Each Capacity (NOV)
Capacity (CAP) (gal)
1,600 2,200 3,200 4,000
1 ...
1
1
1
2
2
2
3
4
(4b) Average  round trip onsite  cycle time for mobile
sludge application vehicles.

   CT = [(LT) + (ULT) + (TT)]/0.75
  where:
  CT
   LT

   ULT
   0.75
Average round trip onsite cycle
time for mobile sludge application
vehicle, min.
Load time, min, varies with vehicle
size (see Table 16-3).
Unload time, min, varies with vehi-
cle size (see Table 16-3).
Onsite travel time to and from
sludge loading facility to sludge ap-
plication  area, min (assumed val-
ues are shown in Table 16-3).
An efficiency factor.
Table 16-3.  Vehicle Load, Unload, and Onsite Travel Time
Vehicle





aLT
ULT
TT
CT
Capacity (CAP) LTa
(gal) (min)
1 ,600 6
2,200 7
3,200 8
4,000 9
= Loading time.
= Unloading time.
= Onsite travel time.
= Average round-trip onsite
ULTa
(min)
8
9
10
11



cycle time.
TTa
(min)
5
5
5
5




CTa
(min)
25
28
31
33




(4c) Single vehicle sludge handling rate.

The actual hourly sludge throughput rates for an on-
site mobile sludge application vehicle is dependent on
the vehicle tank capacity, the cycle time, and an effi-
ciency factor.
                                                         where:
                                                         VHRCAP  =  Single vehicle sludge handling rate,
                                                                       gal/hr.
                                                         CAP       =  Vehicle tank capacity, gal.
                                                         0.9        =  Efficiency factor.

                                                       Table 16-4 shows VHRCAP values for typical size vehicles.

                                                       Table 16-4.  Vehicle Sludge Handling Capacity
                                                       Vehicle Capacity (CAP) (gal)           VHRCAP3 (gal/hr)
                                                                1,600

                                                                2,200

                                                                3,200

                                                                4,000
                                                                            3,456

                                                                            4,243

                                                                            5,574

                                                                            6,545
 VHRCAP = Single vehicle sludge handling rate.

(5) Total land area required.

For virtually all sludge-to-cropland applications, a larger
land area is required than that needed only for sludge
application (SOAR). The  additional area may be re-
quired for changes in cropping patterns, buffer zones,
onsite storage, wasted  land due to unsuitable soil or
terrain, and/or land available in the event of unforeseen
future circumstances. The additional land area required
is site-specific and varies significantly (e.g., from 10 to
100 percent of the SOAR).

  TLAR = (1 + FWWAB)(SDAR)

  where:
  TLAR     = Total land area required for agricul-
                tural land application site, ac.
  FWWAB   = Fraction  of farmland area needed in
                addition to actual sludge application
                area, e.g., buffer zones, unsuitable
                soil or terrain, changes in cropping
                patterns, etc. Default value  = 0.4.
  SOAR     = Farm area required for sludge appli-
                cation, ac (see Calculation #2.)

(6) Lime addition required  for soil pH  adjustment to a
value of at least 6.5.

  TLAPH = (FRPH)(SDAR)

  where:

  TLAPH    = Total land area requiring lime addi-
                tion, ac.
  FRPH     = Fraction of crop growing  area re-
                quiring lime addition to raise pH
                to 6.5. Depending on the  natural
                                                   200

-------
  SOAR
   pH of local soils, this fraction can
   vary from 0 to 1. Default value = 0.5.
=  Farm  area required for sludge appli-
   cation, ac (see Calculation #2.)
                                                    Table 16-5. Gallons of Fuel Per Hour for Various Capacity
                                                              Sludge Application Vehicles
(7) Total land area requiring light grading.

Typical agricultural land used for growing crops is usually
already graded to even slopes. However, when sewage
sludge is added to the soil, additional light grading may be
necessary to improve drainage control and minimize runoff
of sludge solids. This need is site-specific.

  TLARLG = (FRLG)(SDAR)
  where:
  TLARLG

  FRLG
  SOAR
   Total land area requiring light grad-
   ing, ac.
   Fraction of crop-growing area requir-
   ing light grading for drainage con-
   trol. Depending on  local conditions
   at the sludge application sites this
   fraction can vary from 0 to 1. De-
   fault value = 0.3.
   Farm area required for sludge appli-
   cation, ac (see Calculation #2.)
(8) Annual operation labor requirement.

  L = 8 (NOV)(DPY)/0.7
  where:
  L

  NOV

  DRY

  8
  0.7
   Annual operation labor require-
   ment, hr/yr.
   Number of onsite sludge application
   vehicles (see Calculation #4).
   Annual sludge application period,
   days/yr (see Calculation #3).
   Hr/day assumed.
   Efficiency factor.
(9)  Annual diesel fuel  requirement for onsite mobile
sludge application vehicles.

  FU = (HSV)(HPD)(DPY)(DFRCAP)/(VHRCAP)
  where:
  FU
  HSV

  HPD

  DPY

  DFRCAP  =


  VHRCAP  =
   Annual diesel fuel usage, gal/yr.
   Hourly sludge application rate,
   gal/hr (see Calculation #3).
   Daily sludge application period,
   hr/day (see Calculation #3).
   Annual sludge application period,
   days/yr (see Calculation  #3).
   Diesel fuel consumption  rate
   (gal/hr); for specific capacity vehi-
   cle, see Table 16-5.
   Vehicle sludge handling rate (see
   Calculation  #4).
Vehicle Capacity (CAP) (gal)
                  DFRCAP3 (gal/hr)
1,600
2,200
3,200
4,000
3.5
4
5
6
                                        ' DFRCAP = Diesel fuel consumption rate.
                                        (10) Cost of land.

                                          COSTLAND = (TLAR)(LANDCST)
  where:
  COSTLAND=
  TLAR
                                                       LANDCST =
Cost of land, $.
Total land area required for agricul-
tural land application site, ac (see
Calculation  #5).
Cost of land, $/ac. Default value =
0. It is assumed that application
of sludge is to privately owned
farm land.
(11) Cost of lime addition to adjust pH of soil.

  COSTPHT = (TLAPH)(PHCST)
  where:
  COSTPHT =
  TLAPH

  PHCST
Cost of lime addition, $.
Total land area requiring lime addi-
tion, ac (see Calculation #6)
Cost of lime addition, $/ac.  Default
value = $82/acre (ENRCCI/5,445.83);
assumes 2 Tons of lime/ac requirement.
(12) Cost of light grading earthwork.

  COSTEW = (TLARLG)(LGEWCST)

  where:
  COSTEW  = Cost of earthwork grading, $.
  TLARLG   = Total land area requiring light grad-
               ing, ac (see Calculation #7)
  LGEWCST= Cost of light grading earthwork,
               $/ac. Default value = $1,359/ac.
               (ENRCCI/5,445.83).

(13) Cost of onsite mobile sludge application vehicles.

Note: If same vehicle is used both to transport sludge to the
site and to apply sludge to the land, then COSTMAV = 0.
  COSTMAV = (NOV)(COSTPV)
               MSECI
                990.8
  where:
  COSTMAV =  Cost of onsite mobile sludge appli-
                cation vehicles, $.
                                                 201

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   NOV      =  Number of onsite sludge application
                vehicles (see Calculation #4).
   COSTPV  =  Cost of onsite mobile  sludge ap-
                plication vehicle, obtained from
                Table 16-6.
   MSECI    =  Current Marshall and Swift Equip-
                ment Cost Index at time analysis is
                made.
Table 16-6.  Cost of Onsite Mobile Sludge Application
          Vehicles
Vehicle Capacity (CAP) (gal)
                  Cost Per Vehicle
                 (COSTPV) (1994 $)a
1,600
2,200
3,200
4,000
112,000
125,000
158,000
185,000
 Costs were taken from EPA's 1985 Cost Estimation Handbook (U.S.
 EPA, 1985) and inflated to 1994 price levels using the MSECI.
(14) Annual cost of operation labor.

  COSTLB = (L)(COSTL)
  where:
  COSTLB
  L
  COSTL
Annual cost of operation labor, $/yr.
Annual operation labor required, hr/yr.
Cost of operation labor, $/hr. De-
fault value = $22.97/hr.
(ENRCCI/5,445.83).
(15) Annual cost of diesel fuel.

  COSTDSL = (FU)(COSTDF)
  where:
  COSTDSL =
  FU
  COSTDF  =
Annual cost of diesel fuel, $/yr.
Annual diesel fuel usage, gal/yr.
Cost of diesel fuel, $/gal. Default
value = $1.09/gal.
(ENRCCI/5,445.83).
(16)  Annual cost of maintenance for onsite  mobile
sludge application vehicles.
  VMC =
  [(HSV)(HPD)(DPY)(MCSTCAP)/(VHRCAP)]
                          MSECI
                          990.8
  where:

  VMC

  HSV

  HPD
Annual cost of vehicle mainte-
nance, $/yr.
Hourly sludge application rate,
gal/hr (see Calculation #3).
Daily sludge application  period,
hr/day (see Calculation #3).
                                        DPY      =  Annual sludge application period,
                                                     days/yr (see Calculation #3).
                                        MCSTCAP =  Maintenance cost, $/hr of opera-
                                                     tion; for specific capacity of vehicle,
                                                     see Table 16-7.
                                        VHRCAP  =  Vehicle sludge handling rate (see
                                                     Calculation #4).
                                        MSECI    =  Current Marshall and Swift Equipment
                                                     Cost Index at time analysis is made.

                                     Table 16-7.  Hourly Maintenance Cost for Various Capacities
                                               of Sludge Application Vehicles
                                                       Vehicle Capacity (CAP)
                                                              (gal)
                                                              Maintenance Cost (MCSTCAP)
                                                                     ($/hr, 1994 $)a
                                                              1,600

                                                              2,200

                                                              3,200

                                                              4,000
                                                                         6.40

                                                                         7.01

                                                                         7.86

                                                                         9.45
                                      Costs were taken from EPA's 1985 Cost Estimation Handbook (U.S.
                                      EPA, 1985) and inflated to 1994 price levels using the MSECI.

                                     (17) Annual cost of maintenance for land application site
                                     (other than vehicles) including monitoring, recordkeep-
                                     ing, etc.
  SMC = [(TLAR)(16)]
      ENRCCI
      5,445.83
  where:
  SMC

  TLAR
                                        16
                                        ENRCCI
Annual cost of maintenance (other
than vehicles), $/yr.
Total land area  required for land
application site, ac (see Calculation
#5).
Annual maintenance cost, $/ac.
Current Engineering News Record
Construction Cost Index at time
analysis is made.
(18) Total base capital cost.

  TBCC = COSTLAND + COSTPHT + COSTEW
  + COSTMAV

  where:
  TBCC     =  Total base capital cost of agricul-
                tural land application program using
                onsite mobile sludge application
                vehicles, $.
  COSTLAND =  Cost of land for sludge application
                site, $ (see Calculation #10).
  COSTPHT =  Cost of lime addition, $ (see Calcu-
                lation #11).
  COSTEW  =  Cost of light grading earthwork, $
                (see Calculation #12) .
  COSTMAV =  Cost of onsite mobile sludge applica-
                tion vehicles, $ (see Calculation #13).
                                                 202

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(19) Total annual operation and maintenance cost.

   COSTOM = COSTLB + COSTDSL + VMC  + SMC
  where:
  COSTOM
   COSTLB

   COSTDSL

   VMC

   SMC
Total annual operation and mainte-
nance cost for agricultural land ap-
plication program using onsite mobile
sludge application vehicles, $/yr.
Annual cost of operation labor, $/yr
(see Calculation #14).
Annual cost of diesel fuel, $/yr (see
Calculation #15).
Annual cost of vehicle mainte-
nance, $/yr (see Calculation #16).
Annual cost of site maintenance,
$/yr (see Calculation #17).
16.3 Application to Forest Lands

16.3.1   General Information and
         Assumptions Made

The  cost algorithms presented below  for forest land
application estimate only the cost of sewage sludge
application at the forest site using specially designed
onsite liquid sludge application vehicles. It is assumed
that the sludge is transported to the site by one of the
transportation processes discussed in Section 16.5.
Typically, the onsite liquid sludge application vehicles will
obtain sludge from a large "nurse" truck,  or an on-site
sludge storage facility.  These cost algorithms assume
that liquid sludge is applied by means of specially de-
signed tanker trucks equipped  with a spray "cannon"
having a range of approximately 100 ft.

Unlike  agricultural land application  which  usually in-
volves  annual sewage sludge application, forest land
application to a specific site is often done at multi-year
intervals, e.g., every 5 years, which will influence costs.
In addition, forest land sites are  usually  less accessible
to sludge application vehicles than cropland, and on-site
clearing and grading of access roads is often an initial
capital  cost. Provisions for estimating the  cost of clear-
ing brush and trees and grading rough access  roads,
which are often paid by the land owner,  are included in
these cost algorithms.

While provision is made in the  cost algorithms  for in-
cluding  land costs, the municipality generally will not
purchase or lease the application site, and land cost will
be zero.

Base capital costs include (where appropriate) the cost
of land, clearing brush  and trees, grading, and mobile
sludge application vehicles.  Base annual O&M costs
include  labor, diesel fuel for vehicles, vehicle mainte-
nance, and site maintenance.
16.3.2   Process Design and Cost Calculations

(1) Calculate dry solids applied to land per year.

  TDSS = [(SV)(8.34)(SS)(SSG)(365)]/(2,000)(100)

Same as Calculation #1 for agricultural land application
(see Section 16.2 above).

(2) Sludge application  area required.

  SOAR = (TDSS)(FR)/(DSAR)
  where:
  SOAR

  TDSS

  FR
             =  Site area required for sludge appli-
                cation, ac.
             =  Dry solids applied to land, Tons/yr
                (from  Calculation #1).
             =  Frequency of sludge application to for-
                est land at dry solids application rate
                (DSAR) (i.e., period between applica-
                tion of sludge to some forest land
                area),  yr. This value varies depending
                on tree species, tree maturity, whether
                trees are grown for commercial pur-
                poses, and other factors. Default
                value  = 5 yr.
  DSAR     =  Average dry solids application rate,
                Tons of dry solids/ac. This value nor-
                mally  ranges from 20 to 40 for typical
                forest  land sites depending on tree
                species, tree maturity, soil conditions,
                and other factors. Default value = 20
                Tons/ac/yr. (See Chapter 8.)

(3) Hourly sludge volume which  must be applied.

  HSV =  (SV)(365)/(DPY)(HPD)
                                        where:
                                        HSV

                                        SV

                                        DPY
             =  Hourly sludge volume during appli-
                cation period, gal/hr.
             =  Daily sludge volume, gpd. (See Cal-
                culation #1.)
             =  Annual sludge application period,
                days/yr. This value normally ranges
                from 130 to 180 days/yr for forest
                land sites depending on climate,
                soil conditions, and other factors.
                Default value = 150 days/yr.
  HPD      =  Daily sludge application period,
                hr/day. This value normally ranges
                from 5 to 8 hr/day depending on
                equipment used, site size, and other
                factors. Default value = 7 hr/day.

(4) Capacity of onsite mobile sludge application vehicles.
It is assumed that the sludge  has already been trans-
ported to the forest  land application site by a transport
                                                  203

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process such as truck hauling. The onsite mobile ap-
plication vehicles accept the sludge from a large nurse
truck, on-site storage facility, etc., and proceed to the
sludge application area to apply the sludge. Typical
onsite mobile sludge application vehicles  at forest
land sites are specially modified tank trucks  equipped
with a sludge cannon to spray the sludge  at least 100
ft through a 240-degree horizontal arc. The applica-
tion vehicle is modified to handle steep slopes, sharp
turn radius, and doze through small trees and brush.
Such vehicles  can negotiate much rougher terrain,
e.g.,  logging roads,  than conventional road tanker
trucks. Because of the special conditions encountered
in forest land sludge application, it is assumed that the
largest onsite sludge application vehicle feasible has
a capacity of 2,200 gal of sludge. Only two capacity
increments are included  in this  program, i.e., 1,000
gal and 2,200 gal.

(4a) Capacity and number of onsite mobile sludge ap-
plication vehicles.

The capacity and  number of onsite mobile sludge appli-
cation vehicles required is determined by comparing the
hourly sludge  volume,  HSV, with the  vehicle sludge
handling rate, VHRCAP, as shown in Table 16-8.

Above 7,584  gal/hr, the number of 2,200-gal capacity
vehicles required  is calculated by:

   NOV =  HSV/2,528 (round to the next highest integer)
  where:
  NOV

  HSV
Number of onsite mobile sludge ap-
plication vehicles.
Hourly sludge volume during appli-
cation  period, gal/hr (see Calcula-
tion #3).
Table 16-8.  Capacity and Number of Onsite Mobile Sludge
          Application Vehicles Required

                      Vehicle Number of Each Capacity
                         (NOV) Capacity (CAP) (gal)
HSVa (gal/hr)
0 - 1,317
1,317 - 2,528
2,528 - 5,056
5,056 - 7,584
1,000 2,200
1
1
2
3
 Hourly sludge volume during application period.


(4b) Average round trip on-site  cycle time for mobile
sludge application vehicles.
                                        CT = [(LT) + (ULT) + (TT)]/0.75
                                        where:
                                        CT
                                         LT

                                         ULT
                                        0.75
                Average round trip on-site cycle
                time for mobile sludge application
                vehicle, min.
                Load time, min, varies with vehicle
                size (see Table 16-9).
                Unload time, min, varies with vehi-
                cle size (see Table 16-9).
                On-site travel time to and from
                sludge loading facility to sludge ap-
                plication area, min (assumed val-
                ues are shown in Table 16-9).
                An efficiency factor.
                                      (4c) Single vehicle sludge handling rate.
                                      Table 16-9.  Vehicle Load, Unload, and Onsite Travel Time3
Vehicle Capacity, LT ULT TT
CAP (gal) (min) (min) (min)


al_T
ULT
TT
CT
1,000
2,200
=
6810
7 9 10
Loading time.
Unloading time.
Onsite travel time.
Average round-trip onsite cycle time.
CT
(min)
32
35

The actual hourly sludge throughput rates for an onsite
mobile sludge application vehicle is dependent on the
vehicle tank capacity, the cycle time, and an efficiency
factor.

  VHRCAP = [(CAP)(60)(0.9)]/(CT)
                                        where:
                                        VHRCAP

                                        CAP

                                        0.9
                Single vehicle sludge handling rate,
                gal/hr.
                Capacity of onsite mobile sludge ap-
                plication vehicle, gal.
                Efficiency factor.
                                                      Table 16-10  shows  VHRCAP values for typical  size
                                                      vehicles.

                                                      Table 16-10.  Vehicle Sludge Handling Capacity

                                                      Vehicle Capacity, (CAP) (gal)       VHRCAP3 (gal/hr)
                                                1,000

                                                2,200
                                   1,317

                                   2,528
                                       VHRCAP = Single vehicle sludge handling rate.
                                                  204

-------
(5) Total land area required.

For virtually all forest land  sites,  a  larger land area
is required  than  that needed only for sludge appli-
cation (SOAR). The additional area  may be required
for  buffer zones,  on-site  roads, on-site storage,
wasted land due to  unsuitable soil or terrain,  etc.
The  additional land  area  required  is site-specific
and varies significantly, e.g., from 10 to  50 percent
of the SOAR.

  TLAR = (1 + FWWAB)(SDAR)
  where:
  TLAR

  FWWAB   =
   SOAR
Total land area required for forest
land site, ac.
Fraction of forest land site area
used for purposes other than
sludge application, e.g., buffer
zone, internal roads, sludge  stor-
age, waste land, etc. Varies  signifi-
cantly depending on site-specific
conditions. Default value = 0.2 for
forest land sites.
Site area required for sludge appli-
cation, ac (see Calculation #2).
(6) Clearing of brush and trees required.

Often a forest land site will require clearing brush and
trees in access road areas to allow access by the sludge
application vehicle.

  TLAWB = (FWB)(TLAR)
  where:
  TLAWB

  FWB
  TLAR
Total land area with brush and
trees to be cleared, ac.
Fraction of forest land site area re-
quiring clearing of brush and trees
to allow access by application vehi-
cle. Varies significantly depending
on site-specific conditions. Default
value = 0.05 for  forest land sites.
Total land area required for forest
land site, ac (see Calculation #5).
(7) Earthwork required.

Often a forest land application site will require grading
of access roads for the sludge application vehicles, to
provide drainage control,  etc. The extent of grading
required is site-specific.

  TLARG = (FRG)(TLAR)
                                        where:
                                        TLARG
                                        FRG
                                        TLAR
                Total land area requiring grading, ac.
                Fraction of land area requiring
                grading of access roads to allow
                travel by  sludge application vehi-
                cle, etc. Varies significantly de-
                pending on site-specific
                conditions. Default value = 0.05
                for forest land sites.
                Total land area required for forest
                land site, ac (see Calculation #5).
(8) Annual operation labor requirement.

  L = 8 (NOV)(DPY)/0.7
  where:
  L

  8
  NOV

  DRY

  0.7
Annual operation labor requirement,
hr/yr.
Hr/day assumed.
Number of onsite sludge application
vehicles (see Calculation #4).
Annual sludge application period,
days/yr (see Calculation #3).
Efficiency factor.
                                      (9) Annual diesel fuel  requirement for onsite mobile
                                      sludge application vehicles.

                                        FU =  (HSV)(HPD)(DPY)(DFRCAP)/(VHRCAP)
                                        where:
                                        FU
                                        HSV
             =  Annual diesel fuel usage, gal/yr.
             =  Hourly sludge application rate,
                gal/hr (see Calculation #3).
  HPD      =  Daily sludge application  period,
                hr/day (see Calculation #3).
  DPY      =  Annual sludge application  period,
                days/yr (see Calculation #3 above).
  DFRCAP  =  Diesel fuel consumption rate
                (gal/hr); for specific capacity vehicle
                (see Table 16-11).
  VHRCAP  =  Vehicle sludge handling  rate (see
                Calculation #4).
                                      Table 16-11.  Gallons of Fuel Per Hour for Various Capacity
                                                 Sludge Application Vehicles
                                       Vehicle Capacity, (CAP) (gal)
                                  DFRCAP3 (gal/hr)
                                                1,000

                                                2,200
                                       DFRCAP = Diesel fuel consumption rate.
                                                  205

-------
(10) Cost of land for forest land application site.

  COSTLAND = (TLAR)(LANDCST)
  where:
  COSTLAND =
  TLAR

  LANDCST =
               Cost of land for forest land site, $.
               Total land area required for forest
               land site, ac. (see Calculation #5)
               Cost of land, $/ac. Usually the for-
               est land is not purchased by the
               municipality. Default value = 0.
(11) Cost of clearing brush and trees.

  COSTCBT = (TLAWB)(BCLRCST)
  where:
  COSTCBT =
  TLAWB   =
  BCLRCST =
               Cost of clearing brush and trees, $.
               Total land area with brush and
               trees to be cleared, ac (see Calcula-
               tion #6).
               Cost of clearing brush and trees,
               $/ac. Default value = $1,359/acre
               (ENRCCI/5,445.83).
(12) Cost of grading earthwork.

  COSTEW = (TLARG)(GEWCST)
  where:
  COSTEW
  TLARG
               Cost of earthwork grading, $.
               Total land area requiring grading,
               ac (see Calculation #7).
  GEWCST =  Cost of grading earthwork, $/ac. De-
               fault value = $2,039/acre
               (ENRCCI/5,445.83).

(13) Cost of onsite mobile sludge application vehicles.

                                MSECI
  COSTMAV = [(NOV)(COSTPV)]
                                990.8
  where:
  COSTMAV=

  NOV

  COSTPV  =

  MSECI
               Cost of onsite mobile sludge appli-
               cation vehicles, $.
               Number of onsite sludge application
               vehicles (see Calculation #4).
               Cost/vehicle, obtained from Table
               16-12.
               Current Marshall and Swift Equip-
               ment Cost Index at time analysis is
               made.
                                                    Table 16-12. Cost of On-Site Mobile Sludge Application
                                                              Vehicles (1994)
                                                    Vehicle Capacity, (CAP) (gal)
                                COSTPV (1994 $)a
                                                             1,000

                                                             2,200
                                    158,000

                                    198,000
 Costs were taken from EPA's 1985 Cost Estimation Handbook (U.S.
 EPA, 1985) and inflated to 1994 price levels using the MSECI.

(14 ) Annual cost of operation labor.

   COSTLB = (L)(COSTL)
   where:
   COSTLB  =  Annual cost of operation labor, $/yr.
   L         =  Annual operation labor requirement,
                hr/yr (see Calculation #8).
   COSTL   =  Cost of operational labor,  $/hr. De-
                fault value = $22.97/hr
                (ENRCCI/5,445.83).
(15) Annual cost of diesel fuel.

  COSTDSL = (FU)(COSTDF)
                                                      where:
                                                      COSTDSL =
                                                      FU
               Annual cost of diesel fuel, $/yr.
               Annual diesel fuel usage, gal/yr
               (see Calculation #9).
  COSTDF   = Cost of diesel fuel, $/gal. Default
               value = $1.09/gal (ENRCCI/5,445.83).

(16) Annual cost of maintenance of onsite mobile sludge
application vehicles.
                                                      VMC =
                                                      [(HSV)(HPD)(DPY)(MCSTCAP)/(VHRCAP)]
                                        MSECI
                                        990.8
  where:
  VMC

  HSV

  HPD

  DPY

  MCSTCAP =
  MSECI
Annual cost of vehicle mainte-
nance, $/yr.
Hourly sludge application rate,
gal/hr (see Calculation #3).
Daily sludge application period,
hr/day (see Calculation #3).
Annual sludge application period,
days/yr (see Calculation #3).
Maintenance cost, $/hr of operation
for specific capacity of vehicle; see
Table  16-13.
Current Marshall and  Swift Equip-
ment Cost Index at time analysis is
made.
                                                206

-------
Table 16-13.  Hourly Maintenance Cost for Various Capacities
           of Forest Land Sludge Application Vehicles
Vehicle Capacity, (CAP) (gal)
                             MSCTCAP3 ($/hr, 1994)b
         1,000

         2,200
                                     8.05

                                     9.63
 MSCTCAP = Maintenance cost.
' Costs were taken from EPA's 1985 Cost Estimation Handbook (U.S.
 EPA, 1985) and inflated to 1994 price levels using the MSECI.
(17) Annual cost of maintenance for forest land site
(other  than vehicles)  including monitoring,  record-
keeping, etc.
  SMC = [(TLAR)(16)]
  where:
  SMC
                      ENRCCI
                      5,445.83
             =  Annual cost of forest land site main-
                tenance (other than vehicles), $/yr.
  TLAR      =  Total land area required for forest
                land site, ac (see Calculation #5).
  16         =  Annual maintenance cost, $/ac.
  ENRCCI   =  Current Engineering News Record
                Construction Cost Index at time
                analysis is made.

(18) Total base capital cost.

  TBCC  = COSTLAND + COSTCBT + COSTEW +
  COSTMAV
  where:
  TBCC
  COSTLAND =
  COSTCBT =
  COSTEW  =
  COSTMAV=
                Total base capital cost of forest land
                application site using onsite mobile
                sludge application vehicles, $.
                Cost of land for forest land site, $
                (see Calculation #10).
                Cost of clearing brush and trees, $
                (see Calculation #11).
                Cost of earthwork grading, $ (see
                Calculation #12).
                Cost of onsite mobile sludge applica-
                tion vehicles, $ (see Calculation #13).
(19) Total annual operation and maintenance cost.
  COSTOM = COSTLB + COSTDSL + VMC + SMC
  where:
  COSTOM  =
  COSTLB   =

  COSTDSL =

  VMC
                Total annual operation and mainte-
                nance cost for forest land applica-
                tion site using onsite mobile sludge
                application vehicles, $/yr.
                Annual cost of operation labor, $/yr
                (see Calculation #14).
                Annual cost of diesel  fuel, $/yr (see
                Calculation #15).
                Annual cost of vehicle mainte-
                nance, $/yr (see Calculation #16).
   SMC      =  Annual cost of forest land site main-
                tenance (other than  vehicles), $/yr
                (see Calculation #17).

16.4 Land Application at Reclamation Sites

16.4.1   General Information and
         Assumptions Made

The  cost algorithms for land application  of  sewage
sludge at reclamation sites presented below do  not
generate the total land area required, as do the other
land application cost algorithms  in this chapter, but in-
stead generate the annual land area  required. This is
because sewage sludge application for land reclamation
is usually a one-time application  (i.e., sewage sludge is
not applied  again to the same  land  area  at  periodic
intervals  in the future), and the  project must therefore
have a continuous supply  of new disturbed  land on
which to apply sewage sludge in future years throughout
the life of the sludge application  project.

The  cost algorithms presented for land application at
reclamation  sites estimate only the  cost  of  sewage
sludge application at the site using onsite sludge appli-
cation vehicles. It is assumed that the sewage sludge
is transported  to the  site by one of the transportation
processes discussed in Section  16.5.  Typically, the  on-
site sludge application vehicles will obtain sludge from
a large "nurse" truck, or an interim on-site sludge stor-
age facility. However, if the same truck is used to both
haul and  apply the sludge, do not add  the cost of onsite
application trucks (i.e.,  COSTMAV in the  algorithms
would equal zero).

Disturbed or marginal lands  often require extensive
grading, soil pH adjustment by lime addition, scarifying,
and vegetation seeding. Usually,  the landowner pays for
the cost of these operations. However, there are provi-
sions for  including these  costs in the cost algorithms, if
desired.

16.4.2   Process Design and Cost Calculations

(1) Calculate dry solids applied to land per year.

   TDSS  = [(SV)(8.34)(SS)(SSG)(365)]/(2,000)(100)

Same as  Calculation #1 for agricultural land application
(see Section 16.2).

(2) Sludge application area required.

   SOAR  = (TDSS)/(DSAR)
  where:
  SOAR
=  Land area required for sludge applica-
   tion, ac/yr. Since sludge is typically
   applied only once to reclamation
                                                 207

-------
                sites, the sludge application area re-
                quired represents the annual new
                land area which must be located
                each year.
  TDSS     =  Dry solids applied to land, Tons/yr
                (see Calculation #1).
  DSAR     =  Average dry solids application rate,
                Tons of dry solids/ac/yr. This value
                normally ranges from 10 to 100 for
                typical land reclamation sites depend-
                ing on sludge quality, soil conditions,
                and other factors. Default value = 25
                Tons/ac. (See Chapter 9.)

(3) Hourly sludge application rate.

  HSV =  (SV)(365)/(DPY)(HPD)
  where:
  HSV
  SV

  DRY
             =  Hourly sludge application rate, gal/hr.
             =  Daily sludge volume, gpd. (See Cal-
                culation #1.)
             =  Annual sludge application period,
                days/yr. This value normally ranges
                from 100 to 180 days/yr for land
                reclamation sites depending on cli-
                mate,  soil conditions, planting sea-
                sons, and other factors.  Default
                value = 140 days/yr.
   HPD      =  Daily sludge application  period,
                hr/day. This value normally ranges
                from 5 to 8 hr/day depending on
                equipment  used, site size, and other
                factors. Default value = 8 hr/day.

(4) Capacity of onsite mobile sludge application vehicles.

Same as Calculations #4a, b, and c in Section 16.2.2 for
agricultural land application sites.

(5) Total land area required per year.

For virtually all land reclamation sites, a larger land area is
required than that needed  only for sludge  application
(SOAR). The additional area may  be required for buffer
zones, on-site roads,  on-site storage, wasted land  due to
unsuitable terrain, etc. The additional land area required
for land reclamation sites is usually not significant, since
these sites are typically located far from population centers.

   TLAR = (1 + FWWAB)(SDAR)
  where:
  TLAR

  FWWAB   =
                Total land area required for land rec-
                lamation sites, ac/yr.
                Fraction of land  reclamation site
                area used for purposes other than
                sludge application, e.g., buffer zone,
                internal roads, sludge storage, waste
                                                         SOAR
                land,  etc. Varies significantly de-
                pending  on site-specific conditions.
                Default value = 0.3 for land recla-
                mation sites.
                Site area required for sludge appli-
                cation, ac/yr (see Calculation #2).
                                                      (6) Lime addition required for soil pH  adjustment to a
                                                      value of pH = 6.5.

                                                         TLAPH  = (FRPH)(SDAR)
                                                         where:
                                                         TLAPH

                                                         FRPH
   SOAR
Total land  area which must have
lime applied for pH control, ac/yr.
Fraction of  land reclamation site area
requiring addition of lime for adjust-
ment of soil pH to a value of 6.5.
Typically, strip mining spoils have a
low soil pH, and substantial lime addi-
tion may be required. Default value =
1.0 for land reclamation sites.
Site area required for sludge appli-
cation, ac/yr (see Calculation #2).
(7) Earthwork required.

Usually a potential land reclamation site will require
extensive grading to smooth out contours, provide drain-
age control, etc. The extent of grading required is very
site-specific,  and can  represent a significant portion of
the total site preparation cost when the terrain is rough.

  TLARLG  =   (FRLG)(TLAR)
  TLARMG  =   (FRMG)(TLAR)
  TLAREG  =   (FREG)(TLAR)

  where:
  TLARLG   =   Total land area requiring light grad-
                 ing,  ac/yr.
  TLARMG  =   Total land area requiring medium
                 grading, ac/yr.
  TLAREG  =   Total land area requiring extensive
                 grading, ac/yr.
  FRLG     =   Fraction of land area requiring  light
                 grading. Varies significantly depend-
                 ing on site-specific conditions. De-
                 fault value =  0.1.
  FRMG    =   Fraction of land area requiring  me-
                 dium grading. Varies significantly de-
                 pending on site-specific conditions.
                 Default value = 0.3.
  FREG     =   Fraction of land area requiring  ex-
                 tensive grading. Varies significantly
                 depending on site-specific condi-
                 tions. Typically, a land  reclamation
                 site  requires significant heavy grad-
                 ing.  Default value  = 0.6.
                                                   208

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  TLAR     =  Total land area required per year
                (TLAR) (see Calculation #5).

(8) Possible number of monitoring wells needed.

Many state regulatory agencies require that ground-water
quality monitoring wells be installed as a condition of land
reclamation site permitting. The permitting authority may
also  require ground-water monitoring if he or she  has
approved land application in excess of agronomic rates at
a reclamation site, as  allowed  by the federal Part  503
regulation. The number and depth of monitoring wells re-
quired varies as a function of site size, ground-water condi-
tions, and  regulatory  agency  requirements. In  this
algorithm, it is assumed that even the smallest land recla-
mation  site  must have one downgradient  ground-water
quality monitoring well, and one additional monitoring well
for each 200 ac/yr of total site area (TLAR) above 50 ac/yr.
In some cases, at least one upgradient well is also re-
quired.

  NOMWR = 1 + [(TLAR) - 50]/200 (increase to
  next highest integer)

  where:
  NOMWR  =  Number of monitoring wells re-
                quired/yr.
  TLAR     =  Total land area required per year
                (see  Calculation #5).

(9) Operation labor requirement.

  L  = 8 (NOV)(DPY)/0.7
  where:
  L
  8
  NOV
   DPY

   0.7
=  Operation labor requirement,  hr/yr.
=  Hr/day assumed, hr.
=  Number of onsite sludge application
   vehicles (see Calculation #4).

=  Annual sludge application period,
   days/yr (see Calculation #3).
=  Efficiency factor.
(10) Diesel fuel requirements for onsite mobile sludge
application vehicles.

   FU = (HSV)(HPD)(DPY)(DFRCAP)/(VHRCAP)
  where:
  FU
  HSV

  HPD

  DPY

  DFRCAP
   Diesel fuel usage, gal/yr.
   Hourly sludge application rate,
   gal/hr (see Calculation #3).
   Daily sludge application period,
   hr/day (see Calculation #3).
   Annual sludge application period,
   days/yr (see Calculation #3).
   Diesel fuel consumption rate for certain
   capacity vehicle, gal/hr, see Table 16-5.
                                          VHRCAP  =  Vehicle sludge handling rate (see
                                                       Calculation #4).

                                        (11) Annual cost of land.

                                          COSTLAND = (TLAR) (LAN DCST)
                                          where:
                                          COSTLAND =

                                          TLAR
                                          LANDCST =
               Annual cost of land for land recla-
               mation site, $/yr.
               Total land area required for land
               reclamation sites,  ac/yr (see Calcu-
               lation #5).
               Cost of land, $/ac. Typically, the
               land used for reclamation is not pur-
               chased by the municipality. Default
               value = 0.
(12) Annual cost of lime addition to adjust pH of the soil.

  COSTPHT = (TLAPH)(PHCST)

  where:
  COSTPHT = Annual cost of lime addition for pH
               adjustment, $/yr.
  TLAPH     = Total land area which must have
               lime applied for pH control, ac/yr
               (see Calculation  #6).
  PHCST    = Cost of lime addition, $/ac. Default
               value = $163/ac.
               (ENRCCI/5,445.83), based on  4
               Tons of lime/ac (in some cases up
               to 10 Tons/ac may be required for
               extreme  pH conditions).

(13) Annual cost of grading earthwork.

  COSTEW = (TLARLG)(LGEWCST) +  (TLARMG)
  (MGEWCST) +  (TLAREG)(EGEWCST)

  where:
  COSTEW  = Cost of earthwork grading, $/yr.
  TLARLG   = Total land area requiring light grad-
               ing, ac/yr (see Calculation #7).
  LGEWCST= Cost of light grading earthwork,
               $/ac. Default value = $1,359/ac.
               (ENRCCI/5,445.83).
  TLARMG  = Total land area requiring medium
               grading,  ac/yr (see Calculation #7).
  MGEWCST= Cost of medium grading earthwork,
               $/ac. Default value = $2,719/ac.
               (ENRCCI/5,445.83).
  TLAREG   = Total land area requiring extensive
               grading, ac/yr (see Calculation
               #7).
  EGEWCST= Cost of extensive grading earth-
               work, $/ac. Default value =
               $6,797/ac. (ENRCCI/5,445.83).
                                                 209

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(14) Annual cost of monitoring wells.

  COSTMW = ( NOMWR)(MWCST)
  where:
  COSTMW =
  NOMWR  =

  MWCST  =
   Cost of monitoring wells, $/yr.
   Number of monitoring wells re-
   quired/yr (see Calculation #8).
   Cost of monitoring well, $/well. De-
   fault value = $6,797/well
   (ENRCCI/5,445.83).
(15) Cost of onsite mobile sludge application vehicles.

                               MSECI
  COSTMAV = [(NOV)(COSTPV)]
                                990.8
  where:
  COSTMAV=

  NOV

  COSTPV  =

  MSECI
   Cost of onsite mobile sludge appli-
   cation vehicles, $.
   Number of onsite sludge application
   vehicles (see Calculation #4).
   Cost/vehicle, $, obtained from
   Table 16-6.
   Current  Marshall and Swift Equip-
   ment Cost Index at time analysis
   is made.
(16) Annual cost of operation labor.

  COSTLB = (L)(COSTL)
  where:
  COSTLB
  L
  COSTL
   Annual cost of operation labor, $/yr.
   Annual operation labor required, hr/yr.
   Cost of operational labor, $/hr. De-
   fault value = $22.97/hr.
   (ENRCCI/5,445.83).
(17) Annual cost of diesel fuel.

  COSTDSL = (FU)(COSTDF)
  where:

  COSTDSL =  Annual cost of diesel fuel, $/yr.
  FU       =  Annual diesel fuel usage, gal/yr.
  COSTDF  =  Cost of diesel fuel, $/gal. Default
               value = $1.09/gal
               (ENRCCI/5,445.83).

(18) Annual cost of maintenance of onsite mobile sludge
application vehicles.
  VMC =
  [(HSV)(HPD)(DPY)(MCSTCAP)/(VHRCAP)]
                             MSECI
                              990.8
  where:
  VMC
=  Annual cost of vehicle mainte-
   nance, $/yr.
  HSV      =  Hourly sludge application rate,
               gal/hr (see Calculation #3).
  HPD      =  Daily sludge application period,
               hr/day (see Calculation #3).
  DPY      =  Annual sludge application  period,
               days/yr (see Calculation #3).
  MCSTCAP =  Maintenance cost, $/hr of  opera-
               tion; for specific capacity of vehicle
               see Table 16-7.
  VHRCAP  =  Vehicle sludge handling rate (see
               Calculation #4)
  MSECI    =  Current Marshall  and Swift Equipment
               Cost Index at time analysis  is made.
(19) Annual cost of maintenance of land reclamation site
(other than vehicles) for monitoring, recordkeeping, etc.
  SMC = [(TLAR)(16)]
      ENRCCI
      5,445.83
  where:
  SMC

  TLAR

  16
  ENRCCI
Annual cost of land reclamation site
maintenance (other than vehicles), $/yr.
Total land area required, ac (see
Calculation #5).
Annual maintenance cost, $/ac.
Current Engineering News Record
Construction Cost Index at time
analysis is made.
(20) Total base capital cost.

  TBCC = COSTMAV

  where:
  TBCC     = Total base capital cost of land recla-
               mation site using onsite mobile
               sludge application vehicles, $.
  COSTMAV = Cost of onsite mobile sludge applica-
               tion vehicles, $ (see Calculation #15).

(21) Total  annual  operation,  maintenance, land, and
earthwork cost.

  COSTOM = COSTLB + COSTDSL + VMC + SMC +
  COSTLAND  + COSTPHT + COSTEW + COSTMW
                                         where:
                                         COSTOM  =
  COSTLB  =

  COSTDSL =

  VMC
Total annual operation, mainte-
nance, land, and earthwork cost for
land reclamation site using onsite mo-
bile sludge application vehicles, $/yr.
Annual cost of operation  labor, $/yr
(see Calculation #16).
Annual cost of diesel fuel, $/yr (see
Calculation #17).
Annual cost of vehicle mainte-
nance, $/yr (see Calculation #18).
                                                210

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   SMC      =  Annual cost of site maintenance,
                $/yr (see Calculation #19).
   COSTLAND =  Annual cost of land for reclamation
                site, $/yr (see Calculation #11).
   COSTPHT =  Annual cost of lime addition for pH
                adjustment,$/yr (see Calculation #12).
   COSTEW  =  Annual cost of grading  earthwork,
                $/yr (see Calculation #13).
   COSTMW =  Annual cost of monitoring wells,
                $/yr (see Calculation #14).

16.5 Transportation of Sewage Sludge

This section covers the two primary modes of sewage
sludge transport, truck hauling  (for both liquid and de-
watered sludge) and pipeline transport of liquid sludge.
For cost estimate  information  regarding rail  or  barge
transport of sewage sludge, see EPAs Handbook: Esti-
mating Sludge Management Costs (U.S. EPA, 1985).
Generally, truck hauling  is more economical than rail-
road or pipeline when transporting sewage sludge less
than 150 miles. Diesel-equipped  vehicles are an eco-
nomic choice for larger trucks and trucks with high an-
nual mileage operation. Pipelines have been successfully
used for transporting liquid sludge (i.e., usually less than
10 percent solids by weight) from very short distances
up to distances of 10 miles or  more. Liquid sludge
pumping through  pipelines is  generally best accom-
plished with sludge containing 3 percent solids or less.

16.5.1   Truck Hauling of Liquid Sewage Sludge

16.5.1.1   General Information and
          Assumptions Made

For the cost algorithms presented below for truck haul-
ing of liquid sewage sludge, capital costs include pur-
chase  of specially designed tank  trucks,  as well  as
construction of sludge loading facilities at the treatment
plant. The loading facility consists of a concrete slab and
appropriate piping and valving set at a height of 12 ft to
load the tanker from the top. Base annual O&M costs
include driver labor, operational labor, fuel, vehicle main-
tenance, and loading facility maintenance.

16.5.1.2   Process Design and Cost Calculations

(1) Number and capacity of sludge haul trucks.

Liquid sludge is hauled in tanker trucks with capacities
between 1,600 and 6,000 gal. The capacity of the tank
trucks utilized is a function of the volume of sludge to  be
hauled per day and the  round trip haul time. Special
tanker capacities  available are 1,600, 2,000, 2,500,
3,000, 4,000, and 6,000 gal.
(1a) Total volume hauled per trip.

   FACTOR = [SV (LT + ULT + RTHT)(365)]/(HPD)(DPY)
  where:
  FACTOR

  SV
  LT

  ULT
   RTHT
   Urban travel:
   RTHT =
Gallons hauled per trip if only one
truck were utilized.
Daily sludge volume, gpd.
Truck loading time at treatment
plant, hr. Default value = 0.4 hr.
Truck unloading time at application
site, hr. Default value =  1.0 hr. See
Table  16-14 for guidance.
Round trip haul time from treatment
plant to application site, hr. If a
value  is not available, this  value
can be estimated using  an average
mph for truck hauling, as follows:


   RTHD
          25 miles/hr average speed
   Rural travel:

   RTHT =
    RTHD
          35 miles/hr average speed
   Highway travel:
   RTHT =
  where:
  RTHD
                   RTHD
   HPD

   DPY
          45 miles/hr average speed
Round trip haul distance from treatment
plant to application site, miles. If several
sludge application sites are planned
(e.g., private farm agricultural utilization),
use average distance to sites.
Work schedule  for hauling, hr/day.
Default value = 7  hr/day.
Number of days/yr sludge  is hauled,
days/yr. Default  value = 120 days/yr.
See Table 16-15 for guidance.
Table 16-14.  Typical Truck Unloading Time as a Function of
           Type of Land Application Used
Type of Land Application
                  Typical Unloading
                     Time (Hr)
Agricultural

Forest land

Land  reclamation
                        1.0

                        1.5

                        1.0
                                                  211

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Table 16-15.  Typical Days Per Year of Sludge Hauling as a
           Function of Types of Application Used and
           Geographical Region
Type of Application
Agricultural or land
reclamation utilization
Forest land utilization
Geographical
Region
Northern U.S.
Central U.S.
Sunbelt States
Northern U.S.
Central U.S.
Sunbelt States
Typical Days/Yr
of Sludge Hauling
100
120
140
160
180
200
(1b) Number of vehicles and capacity of each truck.

The number of vehicles is calculated using FACTOR
and Table 16-16.

If  FACTOR exceeds  12,000, NTR  =  Factor/6,000
(Round to next highest integer.)
  where:
  NTR
=  Number of trucks  required, from
   Table 16-16.
Table 16-16.  Number of Vehicles and Capacity of Each Truck


FACTOR, (gal)
         Number (NTR) and Capacity (CAP)
             of Tanker Trucks, (gal)a
<1,600

>1,600 but <2,500

>2,500 but <4,000

>4,000 but <8,000

>8,000 but <12,000

>12,000
                   1 at 1,600

                   1 at 2,500

                   1 at 4,000

                   2 at 4,000

                   2 at 6,000

                   All 6,000
 FACTOR =  Gallons hauled per trip if only one truck is used.
 CAP    =  Capacity of tanker trucks required, gal.
 NTR    =  Number of trucks required.
(2) Number of round trips/yr.

  NRT = SV (365)/CAP
  where:
  NRT
  SV

  CAP
=  Number of round trips/yr.
=  Daily sludge volume, gpd (see Cal-
   culation #1).
=  Capacity of tanker trucks required,
   gal (see Table 16-16).
(3) Driver labor requirement.

  DT = (LT + ULT + RTHT) NRT
  where:
  DT
  LT
=  Driver labor requirement, hr/yr.
=  Truck loading time at treatment
   plant, hr (see Calculation #1).
                                            ULT       =  Truck unloading time at application
                                                         site, hr (see Calculation #1).
                                            RTHT     =  Round trip haul time from treatment
                                                         plant to application site, hr (see Cal-
                                                         culation #1).
                                            NRT      =  Number of round trips/yr (see Calcu-
                                                         lation #2).

                                         (4) Annual fuel requirement.

                                         Vehicle fuel usage is a function of truck size. Table 16-17
                                         lists typical fuel usage values for different capacity trucks.

                                            FU = (RTHD)(NRT)/FC
                                           where:
                                           FU
                                           RTHD
                                            NRT
                                                         FC
                Annual fuel requirement, gal/yr.
                Round trip haul distance from treat-
                ment plant to application site,  miles
                (see Calculation #1).
                Number of round trips/yr (see Calcula-
                tion #2).
                Fuel consumption rate, mpg,  see
                Table 16-17.
Table 16-17.  Fuel Use Capacities for Different Sized Trucks

 Truck Capacity (CAP) (gal)      Fuel Consumption (FC) (mpg)
         1,600

         2,500

         4,000

         6,000
                                         (5) Cost of sludge tanker trucks.

                                           TTCOST  = (NTR)(COSTSTT)
                               MSECI
                                990.8
  where:
  TTCOST  =
  NRT

  COSTSTT =

  MSECI
Total cost of all sludge tanker trucks, $.
Number of round trips/yr (see Calcu-
lation #2).
Cost per sludge tanker truck, ob-
tained from Table 16-18.
Current Marshall and Swift Equip-
ment Cost Index at time cost analy-
sis is made.
                                                      Table 16-18.  Cost of Tanker Truck
                                          Tanker Capacity (CAP) (gal)
                                   Cost of Truck
                                (COSTSTT) (1994 $)
1,600
2,500
4,000
6,000
79,000
106,000
132,000
158,000
                                                  212

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(6) Cost of vehicle loading area facilities.
The  tanker truck loading facilities are assumed to
consist of a concrete  slab, appropriate piping  and
valving to a height of  12 ft to  load the tanker from
the top. Cost of the loading area facilities  are
assumed to be a function  of sludge volume, (SV in
Calculation #1), in gal/yr. The relationship of SVto load-
ing area facilities cost is  graduated in a stepped manner.
   COSTLA = (COSTLAB)
         ENRCCI
         5,445.83
  where:
  COSTLA  =

  COSTLAB =
   ENRCCI   =
Total capital cost of loading area
facilities, $.
Base cost of loading area facilities,
$. This is a function of the annual
volume  of sludge hauled,  SV,  in
gal/yr, and can be obtained from
Table 16-19.
Current  Engineering News Record
Construction Cost Index at time
cost analysis is made.
Table 16-19.  Loading Area Costs Based on Sludge Volume
Annual Volume of Sludge
Hauled (SV x 365) (gal/yr)
           Base Cost of Loading Area
          Facilities (COSTLAB) (1994 $)
100,000to 500,000
500,000 to 1 ,000,000
1 ,000,000 to 2,000,000
2,000,000 to 4,000,000
4,000,000 to 8,000,000
8,000,000(0 12,000,000
12,000,000(0 16,000,000
16,000,000(020,000,000
20,000,000 and over
27,000
41 ,000
54,000
68,000
82,000
95,000
109,000
122,000
136,000
(7) Annual vehicle maintenance cost.
Maintenance cost per vehicle mile traveled is a function
of truck capacity and  initial cost of truck. The factors
listed in Table 16-20 are used to calculate vehicle main-
tenance costs.
  VMC = (RTHD)(NRT)(MCM)
             MSECI
              990.8
  where:
  VMC
  RTHD
   NRT
Annual vehicle maintenance cost, $.
Round trip haul distance from treat-
ment plant to application site,  miles
(see Calculation #1).
Number of round trips/yr (see  Calcu-
lation #2).
                                        MCM      =  Maintenance cost per mile traveled,
                                                     $/mile from Table  16-20.
                                        MSECI    =  Current Marshall and Swift Equip-
                                                     ment Cost Index at time cost analy-
                                                     sis is made.

                                     Table 16-20.  Vehicle Maintenance Cost Factors
                                      Truck Capacity
                                        (CAP) (gal)
                            Maintenance Cost (MCM)
                            $/mile Traveled, (1994 $)
     1,600

     2,500

     4,000

     6,000
                                  0.37

                                  0.42

                                  0.47

                                  0.53
(8) Loading area facility annual maintenance cost.

For the purposes of this  program,  it  is assumed that
loading  area  facilities annual maintenance cost is a
function of loading area facility capital  cost.

  MCOSTLA = (COSTLA)(0.05)

  where:
  MCOSTLA =  Annual maintenance cost  for load-
                ing facilities, $/yr.
  COSTLA  =  Total capital cost of loading area fa-
                cilities, $ (see Calculation  #6).
  0.05       =  Assumed annual maintenance cost
                factor as a function of total loading
                area facility capital cost.

(9) Annual cost of operation labor.

  COSTLB = (DT)(COSTL)(1.2)
                                       where:
                                       COSTLB   =
                                       DT

                                       COSTL

                                       1.2
                Annual cost of operation labor, $/yr.
                Driver labor requirement, hr/yr (see
                Calculation #3).
                Cost of labor, COSTL, $/hr. Default
                value = $22.97/hr. (ENRCCI/5,445.83).
                A factor to account for additional la-
                bor required  at the loading facility.
(10) Annual cost of diesel fuel.

  COSTDSL = (FU)(COSTDF)
  where:
  COSTDSL =
  FU
             Annual cost of diesel fuel, $/yr.
             Annual fuel requirement, gal/yr (see
             Calculation #4).
COSTDF  =  Cost of diesel fuel, $/gal. Default
             value = $1.09. (ENRCCI/5,445.83).
                                                 213

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(11) Total base capital cost.

  TBCC = TTCOST + COSTLA
                                       SVCY = (SV)(365)/202
  where:
  TBCC
  TTCOST   =

  COSTLA   =
Total base capital cost, $.
Total cost of all sludge tanker
trucks, $ (see Calculation #5).
Total capital  cost of loading area fa-
cilities, $ (see Calculation #6).
(12) Annual operation and maintenance cost.

  COSTOM = (VMC) + (MCOSTLA) + (COSTLB) +
  (COSTDSL)

  where:
  COSTOM  =  Total annual operation and mainte-
                nance cost, $/yr.
  VMC      =  Annual vehicle maintenance cost, $
                (see Calculation #7).
  MCOSTLA =  Annual maintenance cost for loading
                facilities,  $/yr (see Calculation #8).
  COSTLB   =  Annual cost of operation labor, $/yr
                (see Calculation #9).
  COSTDSL =  Annual cost of diesel fuel, $/yr (see
                Calculation #10).

16.5.2   Truck Hauling of Dewatered
         Sewage Sludge

16.5.2.1   General Information and
          Assumptions Made

Capital costs in the cost algorithms presented below for
dewatered sewage sludge transport include construc-
tion of a truck loading facility designed to accommodate
the sludge volume within the operating schedule. Costs
include  construction of a  concrete  loading slab,  and
purchase of skip loaders and trucks. Annual O&M costs
include vehicle and loading facility maintenance, driver
and operational labor, and diesel fuel for vehicles.

16.5.2.2   Process Design and Cost Calculations

Same as Calculation #1 for truck hauling of liquid sew-
age sludge, shown in Section 16.5.1 above.

(1) Annual sludge volume  hauled, cu yd/yr.

Trucks which haul dewatered sludge are sized in terms
of yd3 of capacity. Therefore, it is necessary to convert
gal of dewatered sludge to yd3 of dewatered sludge.
  where:
  SVCY
  SV
  202
=  Sludge volume hauled, cu yd/yr.
=  Daily sludge volume, gpd.
=  Conversion factor, gal/cu yd.
(2) Number and capacity of sludge haul trucks.

Dewatered sludge is hauled in trucks with capacities
between  7 and 36 cu yd. The capacity of the trucks
utilized is a function of the volume of sludge to be
hauled per day and the round trip hauling time. Typical
capacities available are 7, 10,15, 25, and 36 cu yd.

(2a) Total sludge volume hauled per day.

  FACTOR =  SVCY(LT + ULT + RTHT)/(HPD)(DPY)
                                       where:
                                       FACTOR

                                       SVCY

                                       LT


                                       ULT


                                       RTHT
                Cu yd which would have to be hauled
                per trip if only one truck were utilized.
                Sludge volume hauled, cu yd/yr
                (see Calculation #1).
                Truck loading time at treatment
                plant, hr (see Calculation #1 for liq-
                uid sludge, section 16.5.1.2).
                Truck unloading time at application
                site, hr (see Calculation #1  for liq-
                uid sludge, Section 16.5.1.2).
                Round trip haul time from treatment
                plant to application site, hr (see Calcula-
                tion #1 for liquid sludge, Section 16.5.1.2).
                                     (2b) Capacity and number of haul vehicles.

                                     Capacity and number of haul vehicles are calculated
                                     using FACTOR and Table 16-21.
                                     Table 16-21. Capacity and Number of Haul Vehicles


                                     FACTOR (cu yd)
                         Number (NTR) and Capacity3
                           of Trucks (CAP) (cu yd)
                                     <7

                                      7 to 10

                                     10 to 15

                                     15 to 25

                                     25 to 36

                                     36 to 50

                                     50 to 72
                                  1 at 7

                                  1 at 10

                                  1 at 15

                                  1 at 25

                                  1 at 36

                                  2 at 25

                                  2 at 36
                                     ' NTR = Number of trucks required.
                                                 214

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If FACTOR exceeds 72, use:
                                        (6) Cost of sludge haul trucks.
   NTR =
         FACTOR
            36
  CAP = 36 cu yd.
      (Round to next highest integer).
  where:
  NTR
  CAP

(3) Number of round trips/yr.

  NRT = (SVCY)/(CAP)
=  Number of trucks required. Calcu-
   lated from Table 16-21.
=  Capacity of truck required, cu yd.
  where:
  NRT

  SVCY

  CAP


(4) Driver time.
   Number of round trips/yr (round to
   next highest integer).
   Annual sludge volume hauled, cu
   yd/yr (see Calculation #1).
   Capacity of truck,  cu yd (see Calcu-
   lation #2).
Same as Calculation #3 for truck hauling of liquid sew-
age sludge in Section 16.5.1.2.

(5) Annual fuel requirement.

Vehicle fuel usage is a function  of truck size. Table
16-22 lists typical fuel usage values  for different ca-
pacity trucks.

  FU = (RTHD)(NRT)/(FC)
  where:
  FU
  RTHD
   NRT

   FC
   Annual fuel requirement, gal/yr.
   Round trip haul distance from
   treatment plant to application site,
   miles (see Calculation #1 for liq-
   uid sludge in Section 16.5.1.2).
   Number of round trips/yr (see Calcu-
   lation #3).
   Fuel consumption rate, miles/gal,
   see Table 16-22.
Table 16-22.  Fuel Usage Values for Different Sized Trucks


 Truck Capacity (CAP) (cu yd)
                Fuel Consumption (FC)
                     (miles/gal)
            7

           10

           15

           25

           36
                                                       TCOSTTRK = (NTR)(COSTTRK)
                                                                         MSECI
                                                                          990.8
  where:
  TCOSTTRK=  Total cost of dewatered sludge haul
                trucks, $.
  NTR       =  Number of trucks required (see Cal-
                culation #2).
  COSTTRK =  Cost per truck, obtained from Table
                16-23.
  MSECI     =  Current Marshall and Swift Equip-
                ment Cost Index at time cost analy-
                sis is made.

Table 16-23.  Costs for Different Sized Trucks
Truck Capacity (CAP) yd3
                   Cost of Truck
                (COSTTRK) (1994 $)
7
10
15
25
36
86,000
129,000
172,000
226,000
282,000
                                        (7) Cost of vehicle loading facilities.
                                        Truck loading facilities are assumed to consist of a con-
                                        crete slab, one or more skip loaders to load the trucks, and
                                        miscellaneous improvements such as drainage,  lighting,
                                        etc. Cost of the truck loading facilities are assumed to be
                                        a function of sludge volume in yd3/yr (SVCY in Calculation
                                        #1). The relationship of SVCY to loading area facilities cost
                                        is graduated in a stepped  manner and depends on the
                                        number of loading vehicles required.
  COSTLA = (COSTLAB)
         ENRCCI
         5,445.83
  where:
  COSTLA  =

  COSTLAB =
                                          ENRCCI    =
Total capital cost of loading area fa-
cilities, $.
Base cost of loading area facilities, $.
This is a function of the annual vol-
ume of sludge hauled (SVCY in Calcu-
lation #1) and can be obtained  from
Table 16-24.
Current Engineering News Record
Construction Cost Index at time cost
analysis is made.
                                                 215

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Table 16-24.  Loading Area Costs
 Annual Volume of Sludge
   Hauled (SVCY) (yd3)
           Base Cost of Loading Area
          Facilities (COSTLAB) (1994 $)
500 to 2,500
2,500 to 5,000
5,000to 10,000
10,000(020,000
20,000 to 40,000
40,000 to 60,000
60,000 to 80,000
80,000to 100,000
100,000 and over
54,000
61 ,000
68,000
109,000
122,000
136,000
204,000
251 ,000
299,000
(8) Annual vehicle maintenance cost.
Maintenance cost per vehicle mile traveled is a function of
truck capacity and initial cost of the truck.The factors out-
lined in Table 16-25 are used to calculate vehicle mainte-
nance costs.
  VMC = (RTHD)(NRT)(MCM)
            MSECI
             990.8
  where:
  VMC
  RTHD
   NRT

   MCM

   MSECI
Annual maintenance cost, $/yr.
Round trip haul distance from treat-
ment plant to application site, miles
(see Calculation #1  for truck hauling
of liquid sewage sludge).
Number of round trips/yr (see Calculation
#3).
Maintenance cost/mile travelled, $/mile
from Table 16-25.
Current Marshall and Swift Equipment
Cost Index at time cost analysis is made.
Table 16-25.  Vehicle Maintenance Cost Factors
 Truck Capacity (CAP) yd3
              Maintenance Cost (MCM)
              $/mile Traveled (1994 $)
7
10
15
25
36
0.34
0.42
0.49
0.59
0.70
(9) Annual maintenance cost for loading area facilities.

For the purposes of this program, it is assumed that loading
area facilities annual  maintenance  cost is a function  of
loading area facilities capital cost.

   MCOSTLA = (COSTLA)(0.05)
  where:
  MCOSTLA =

  COSTLA   =

  0.05
                Annual maintenance cost for loading
                area facilities, $/yr.
                Total capital cost of loading area facili-
                ties, $ (see Calculation #7).
                Assumed annual maintenance cost
                factor as a  function of total loading
                area facilities capital  cost.
                                                      (10) Annual cost of operational labor.

                                                        COSTLB = (DT)(COSTL)(1.2)
                                                        where:
                                                        COSTLB
                                                        DT
                                        COSTL
                                        1.2
                Annual cost of operational labor, $/yr.
                Driver labor requirement, hr/yr (see
                Calculation #3 for truck hauling of
                liquid sludge, Section  16.5.1.2).
                Cost of labor, $/hr. Default value =
                $22.97/hr. (ENRCCI/5,445.83).
                A factor to account for additional la-
                bor required at loading facility.
(11) Annual cost of diesel fuel.

  COSTDSL = (FU)(COSTDF)
  where:
  COSTDSL =
  FU
                Annual cost of diesel fuel, $/yr.
                Annual fuel requirement, gal/yr (see
                Calculation #5).
  COSTDF  =  Cost of diesel fuel, $/gal. Default
                value = $1.09/gal. (ENRCCI/5,445.83).

(12) Total base capital cost.

  TBCC = TCOSTTRK + COSTLA
                                        where:
                                        TBCC
                                        TCOSTTRK =
                Total base capital cost, $.
                Total cost of dewatered sludge haul
                trucks, $ (see Calculation #6).
  COSTLA   =  Total capital cost of loading area fa-
                cilities, $.
(13) Annual operation and maintenance cost.

  COSTOM = (VMC) + (MCOSTLA) + (COSTLB) +
  (COSTDSL)

  where:
  COSTOM  =  Total annual operation and mainte-
                nance cost, $/yr.
  VMC      =  Annual vehicle maintenance cost,
                $/yr (see Calculation #8).
  MCOSTLA =  Annual loading facility maintenance
                cost, $/yr (see Calculation #9).
  COSTLB   =  Annual cost of operation labor, $/yr
                (see Calculation #10).
                                                  216

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   COSTDSL =  Annual cost of diesel fuel, $/yr (see
                Calculation #11).

16.5.3   Long-Distance Pipeline Transport of
         Liquid Sewage Sludge

16.5.3.1   General  Information and
          Assumptions Made
Friction losses associated with sludge pipelines have been
taken into account in the cost algorithms presented below
by applying a "K" factorto an otherwise unmodified Hazen-
Williams formula. This "K" factor, which is a function of both
sludge solids content and sludge type, is discussed in
more detail in Calculation #2 below. Pipelines with coated
interiors (e.g., glass or cement mortar linings) are often
used as a means of reducing friction loss. Because dried
sludge can "cake" on interior pipe walls, flushing pipelines
with  clean water or treated  effluent is also commonly
practiced as a means of reducing friction loss due to such
"caking."  In addition, flushing has been  used as a means
for preventing sludge solids from  settling and hardening in
dormant pipelines.
Cost considerations for these algorithms include: pipe-
line and  pumping station construction costs and O&M
labor, materials,  and energy requirements. Large vari-
ations in  construction costs are  associated with certain
route-specific variables, such as  the number of river
crossings or the fraction of pipeline length requiring
excavation of rock. To obtain the best results, the user
is encouraged to obtain or plot a viable pipeline route on
a suitable scale map and input the most accurate design
parameter values possible. Cost of right-of-way acquisi-
tion is not included in these algorithms.

16.5.3.2   Process Design and Cost Calculations
(1) Pipeline diameter.

   PD =  12 [SV/(63,448)(HPD)]° 5
(Round to next highest even integer.)
  where:
  PD
  SV
  63,488
   HPD
Pipeline diameter, inches.
Daily sludge volume, gpd.
Conversion factor = (3.1416/4)[(3
ft/sec)(7.48 gal/cu ft)(86,400
sec/day)/(24 hr/day)]
Hours per day of pumping, HPD, hr.
Note: Pipeline is assumed to be flowing full.

(2) Head loss due to pipeline friction.

  PFL = K [(SV)/(HPD)(PD)263(C)(16.892)]1 852
                                        where:
                                        PFL
                                         K
                                        2.63
                                        C
                Head loss due to pipe friction, ft/ft. Is
                function of pipe diameter, velocity,
                and "C" value selected.
                Coefficient to adjust for increased
                head loss due  to sludge solids con-
                tent. No default value. Pipeline fric-
                tion losses may be much higher for
                transporting sewage sludge than for
                transporting water, depending  on
                such factors as the sludge  concentra-
                tion (percent solids by weight) and
                the type of sludge (raw primary, di-
                gested, etc.). The user is cautioned
                that the K factors provided  in Table
                16-26 are highly simplified  and may
                give inaccurate results for pipeline
                friction loss. An elaborate method for
                design engineering calculations is
                provided in U.S. EPA, 1979.
                Hazen-Williams constant.
                Hazen-Williams friction coefficient.
                Default value = 90.
                                                                                    2.63
                                         16.892    =  (646,000 gpd/cfs)/(24)(2.31)(12)
                                      Table 16-26.  Factors for Various Sludge Concentrations and
                                                 Two Types of Sludge

                                                                        K Factor
Solids Concentration
Percent by Weight
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Digested
Sludge
1.05
1.10
1.25
1.45
1.65
1.85
2.10
2.60
Untreated
Primary Sludge
1.20
1.60
2.10
2.70
3.40
4.30
5.70
7.20
(3) Head required due to elevation difference.

  HELEV = ELEVMX - PSELEV

  where:
  HELEV    =  Head required due to elevation
                difference, ft.
  ELEVMX  =  Maximum elevation in the pipeline, ft.
  PSELEV  =  Elevation at the start of the pipe-
                line, ft.
                                                   217

-------
(4) Total pumping head required.

  H = [(PL)(PFL) + HELEV]
                                     (7) Horsepower required per pump station.

                                       HPS = HP/NOPS
  where:
  H
  PL
  PFL

  HELEV
Total pumping head required, ft.
Pipeline length,  ft.
Head loss due to pipe friction, ft/ft
(see Calculation #2).
Head required  due to elevation
difference, ft (see Calculation #3).
(5) Number of pumping stations.

  NOPS = H/HAVAIL

If the decimal ending for the MOPS resultant is greater than
or equal to 0.25, then round up to the next higher integer. If
it is less than 0.25, round down. Thus, if MOPS is 2.35, use
3 pump stations. If MOPS = 2.10, use 2 pump stations.
  where:
  NOPS
  H
  H AVAIL
Number of pumping stations.
Total pumping head required, ft.
Head available from each pumping sta-
tion, ft. This is a function of the type of
pump, sludge flow rate, and whether
or not pumps are placed in series. Ob-
tain this value from Table 16-27.
Table 16-27.  Head Available from Each Pumping Station
Pipe Diameter (PD)
(inches)
4& 6
8
10& 12
14& 16
18&20
Head Available
(HAVAIL) (ft)
450
260
230
210
200
(6) Total horsepower required for pump stations.

  HP = (H)(SV)(8.34)/(HPD)(60)(0.50)(33,000)

  where:
  HP        =  Total pumping horsepower required, hp.
  H         =  Total  pumping head required, ft
                (see Calculation #5).
  SV        =  Daily sludge volume, gpd (see Cal-
                culation #1).
  HPD      =  Hours per day of pumping, HPD, hr
                (see Calculation #1).
  33,000     =  Conversion  factor, hp to ft-lb/min.
  60         =  Conversion  factor, min/hr.
  0.50       =  Assumed pump  efficiency.
  8.34       =  Density of water, Ib/gal.
  where:
  HPS

  HP

  NOPS
Horsepower required per pump
station,  hp.
Total pumping horsepower required,
hp (see  Calculation #6).
Number of pumping stations (see
Calculation #5).
                                     (8) Electrical energy requirement.

                                       E = [(0.0003766)(1 -2)(H)/(0.5)(0.9)](SV)
                                       (365)(8.34)/1,000
                                       where:
                                       E
             =  Electrical energy, kWhr/yr.
  0.0003766 =  Conversion factor, kWhr/1,000
                ft-lb.
  8.34       =  Density of water, Ib/gal.
  1.2        =  Assumed specific gravity of sludge.
  0.5        =  Assumed pump efficiency.
  0.9        =  Assumed motor efficiency.

(9) Operation and maintenance labor requirement.

  L = (NOPS)(LPS) + (PL)(0.02)
                                                       where:
                                                       L

                                                       NOPS

                                                       LPS
                                                       PL
                                                       0.02
                                                     Annual operation and maintenance
                                                     labor, hr/yr.
                                                     Number of pumping stations (see
                                                     Calculation #5).
                                                     Annual labor per pump station, hr/yr.
                                                     This is a function of pump station horse
                                                     power, HPS, as shown in Table 16-28.
                                                     Pipeline length,  ft (see Calculation #4).
                                                     Assumed maintenance hr/yr per ft
                                                     of pipeline, hr/ft.
                                     Table 16-28.  Annual Labor Per Pump Station
                                        Pump Station
                                      Horsepower (HPS)
                                 Annual O&M Labor
                                     (LPS) (hr)
25
50
75
100
150
200
250
300
350
700
720
780
820
840
870
910
940
980
                                                 218

-------
(10) Cost of installed pipeline.

  COSTPL = (1 + 0.7 ROCK)(1 + 0.15 DEPTH)
  PL (COSTP,

  where:
  COSTPL   =
  0.7        =

  ROCK     =

  0.15       =


  DEPTH    =
  PL       =
  COSTP   =

  ENRCCI  =
               Cost of installed pipeline, $.
               Assumed fraction of pipeline length
               that requires rock excavation.
               Fraction of pipeline length that re-
               quires  rock excavation.
               Assumed fraction of pipeline length
               that does not require rock excava-
               tion, but is greater than 6 ft deep.
               Fraction of pipeline length that does
               not involve rock excavation, but is
               greater than 6 ft deep.
               Pipeline length, ft (see Calculation #4).
               Pipeline cost per unit length, $/ft. This
               cost is  obtained from Table 16-29.
               Current Engineering News Record
               Construction Cost Index at time
               analysis is made.
Table 16-29.  Pipeline Cost

 Pipeline Diameter (PD)
       (inches)
                             Installed Cost (COSTP)
                                 ($/ft, 1994 $)a
4
6
8
10
12
14
16
18
20
28.68
30.99
34.39
37.93
41.33
48.26
52.88
58.59
68.92
 Costs were taken from EPA's 1985 Cost Estimation Handbook (U.S.
 EPA, 1985) and inflated to 1994 price levels using the MSECI.
(11) Cost of pipeline crossings.
  COSTPC = [NOH($26,000) + NODH($52,000) +
  NRC($19,000) + NOSR($116,000) +
  NOLR($462,000)] ENRCCI
  where:
  COSTPC
  NOH

  NODH
                   5445.83

               Cost of pipe crossings, $.
               Number of 2- or 4-lane highway
               crossings. Default value = 1.
               Number of divided highway cross-
               ings, NODH. Default value =  0.
  NRC      =  Number of railroad tracks (2
               rails/track) crossed. Default value = 2.
  NOSR    =  Number of small rivers crossed. De-
               fault value = 0.
  NOLR    =  Number of large rivers crossed. De-
               fault value = 0.
  ENRCCI  =  Current Engineering News Record
               Construction Cost Index at time
               analysis is made.

(12) Cost of pump stations.


  COSTPS = NOPS [$218,000 +
  $3,600 (HPS-25)]

  where:
  COSTPS
  NOPS

  HPS

  MSECI
               Construction cost of all pump stations.
               Number of pumping stations (see
               Calculation #5).
               Horsepower required per pump sta-
               tion, hp (see Calculation #7).
               Current Marshall and Swift Equip-
               ment Cost  Index at time analysis is
               made.
Note: If HPS is less than 25 hp, then, for this calculation,
let HPS = 25 hp.

(13) Annual cost of electrical energy.

  COSTEL = (E)(COSTE)
                                                      where:
                                                      COSTEL  =
                                                      E
                                                      COSTE
                                                                   Total annual cost of electricity, $/yr.
                                                                   Electrical energy requirement, kWhr/yr.
                                                                   Unit cost of electricity, $/kWhr. De-
                                                                   fault value = $0.121/kWhr
                                                                   (ENRCCI/5445.83).
                                                    (14) Annual cost of operation and maintenance labor.

                                                      COSTLB = (L)(COSTL)
                                                      where:
                                                      COSTLB

                                                      L

                                                      COSTL
               Annual cost of operation and main-
               tenance labor, $/yr.
               Operation and maintenance labor
               requirement, hr/yr.
               Unit cost of labor, $/hr. Default
               value = $22.97/hr
               (ENRCCI/5445.83).
(15)  Cost  of pumping station  replacement parts and
materials.
                                                      COSTPM = NOPS (PS)
                        MSECI
                         990.8
                                                219

-------
  where:
  COSTPM

  PS
   MSECI
Annual cost of pumping station re-
placement parts and materials, $/yr.
Annual cost of parts and supplies for
a single pumping station, $/yr. This
cost is a function of pumping station
horse power as shown in Table 16-30.
Current Marshall and Swift Equipment
Cost Index at time analysis is made.
Table 16-30.  Annual Cost of Pumping Station Parts and
           Supplies
    Pump Station
  Horsepower (HPS)
           Annual Parts and Supplies3
             Cost (PS) ($/Yr, 1994 $)
         25

         50

         75

        100

        150

        200

        250

        300

        350
                    1,420

                    1,490

                    1,680

                    1,820

                    1,980

                    2,100

                    3,750

                    3,910

                    4,100
 Costs were taken from EPA's 1985 Cost Estimation Handbook (U.S.
 EPA, 1985) and inflated to 1994 price levels using the MSECI.

(16) Total base capital cost.

  TBCC = COSTPL + COSTPC + COSTPS
  where:
  TBCC
  COSTPL
  COSTPC
  COSTPS
Total base capital cost, $.
Cost of installed pipeline, $.
Cost of pipeline crossings,  $.
Cost of pump stations, $.
(17) Total annual operation and maintenance cost.

  COSTOM = COSTEL + COSTLB + COSTPM

  where:
  COSTOM  = Total annual operation and mainte-
               nance cost, $/yr.
  COSTEL   = Annual cost of electrical energy, $/yr.
  COSTLB   = Annual cost of operation and main-
               tenance labor, $/yr.
  COSTPM  = Cost of pumping station replace-
               ment parts and materials, $/yr.

16.6  Example of Preliminary Cost
      Estimation for Agricultural Land
      Application to Cropland

The following preliminary cost estimation for land applica-
tion of sewage sludge to cropland is for a midwestern
citygeneratingadailysludgevolumeofl 31 ,894gpd(20
dry t/day,  22 T/day).1 The sludge has a suspended
solids concentration of 4 percent and the appropriate
application rate for growing corn at this site was de-
termined to be 4 T/ac/yr (9 t/ha/yr).

16.6. 1  Process Design and Cost Calculations

(1) Calculate dry solids applied to land per year.

  TDSS = [(SV)(8.34)(SS)(SSG)(365)]/(2,000)(100)
=  Dry solids applied to land, Tons/yr.
=  131,894gpd.
=4 percent.
=  Calculate using the following equations:
   - SS)/100) + (SS)/(1.42)(100)]

   - 4)/100)
  where:
  TDSS
  SV
  SS
  SSG

  SSG  =

  SSG  =

  SSG  = 1.01

  TDSS = [(131,894)(8.34)(4)(1.01)(365)]/(2,000)(100)

  TDSS = 8,126 Tons/year

(2) Sludge application area required.

  SOAR = (TDSS)/(DSAR)
  where:
  SOAR

  TDSS
  DSAR
=  Farm area required for sludge appli-
   cation,  ac.
=  8,126 Tons/yr.
=  4 Tons/ac/yr.
                                       SOAR = (8,126)/(4)

                                       SOAR = 2,302 ac.

                                     (3) Hourly sludge application rate.

                                       HSV = (SV)(365)/(DPY)(HPD)

                                       where:
                                       HSV      =  Hourly sludge application rate, gal/hr.
                                       SV        =  131,894gpd.
                                       DPY      =  120 days/yr from Table 16-1.
                                       HPD      =  8 hr/day.

                                       HSV= (131,894)(365)/(120)(8)

                                       HSV= 50,147 gal/hr.
                                    1 See Appendix D for equations for converting sludge volume to dry
                                    metric tons.
                                                220

-------
(4) Capacity of onsite mobile sludge application vehicles.
It is assumed that the sludge has already been transported
to the private  farm land application site by a large-haul
vehicle. The onsite mobile application vehicles accept the
sludge from the transport vehicle and proceed to the
sludge application area to apply the sludge.
(4a) Capacity and number of onsite mobile sludge ap-
plication vehicles.
The capacity and number of onsite mobile sludge appli-
cation vehicles required is determined  by comparing the
hourly sludge volume, (HSV), with the vehicle sludge
handling rate, (VHRCAP), as shown in Table 16-2.
Since the HSV is 50,147 gal/hr, the number of 4,000-gal
capacity vehicles required is calculated by:

  NOV = HSV/6,545 (round to the next highest integer)
                                          FRPH
                                          SOAR
             =  0.5.
             =  2,032 ac.
  where:
  NOV
=  Number of onsite sludge application
   vehicles.
=  50,147 gal/hr.
   HSV

   NOV = 50,147/6,545

   NOV = 8

(4b) The average round trip onsite cycle time (CT) for
mobile sludge  application vehicles with  a  capacity of
4,000 gal. is 33 from Table 16-3.
(4c) The VHRCAP for a single vehicle  is  6,545 from
Table  16-4.
(5) Total land area required.

   TLAR = (1 + FWWAB)(SDAR)
  where:
  TLAR

  FWWAB
  SOAR
   Total land area required for agricul-
   tural land application site, ac.
   0.4.
   2,032 ac.
  TLAR = (1  + 0.4)(2,032)

  TLAR = 2,845 ac.
(6) Lime addition required for soil pH adjustment to a
value of at least 6.5.
  TLAPH = (FRPH)(SDAR)

  where:
  TLAPH    = Total land area requiring lime addi-
               tion, ac.
  TLAPH = (0.5)(2,032)

  TLAPH = 1,016 ac.

(7) Total land area requiring light grading.

  TLARLG = (FRLG)(SDAR)

  where:
  TLARLG  =  Total land area requiring light
               grading, ac.
  FRLG    =  0.3.
  SOAR    =  2,032 ac.

  TLARLG = (0.3)(2,032)

  TLARLG = 610 ac.
(8) Annual operation labor requirement.

  L = 8 (NOV)(DPY)/0.7
                                          where:
                                          L

                                          NOV
                                          DPY
                                          8
                                          0.7
               Annual operation labor requirement,
               hr/yr.
               8
               120 days/yr.
               Hr/day assumed.
               Efficiency factor.
  L = 8 (8)(120)/0.7

  L = 10,971 hr/yr.

(9) Annual  diesel fuel requirement for onsite  mobile
sludge application vehicles.

  FU = (HSV)(HPD)(DPY)(DFRCAP)/(VHRCAP)
  where:
  FU
  HSV
  HPD
  DPY
  DFRCAP
  VHRCAP
Annual diesel fuel usage, gal/yr.
50,147 gal/hr.
8 hr/day.
120 days/yr.
6 gal/hr from Table 16-5.
6,545 gal/hr.
                                          FU = (50,147)(8)(120)(6)/(6,545)

                                          FU = 44,132 gal/yr.

                                       (10) Cost of land (COSTLAND) is zero because it is
                                       assumed that the application of sewage sludge is on
                                       privately owned farm land.
                                                221

-------
(11) Cost of lime addition to adjust pH of soil.

  COSTPHT = (TLAPH)(COSTPHT)

  where:
  COSTPHT =  Cost of lime addition,  $.
  TLAPH    =  1,016ac.
  PHCST    =  $82/ac., this value assumes 2 Tons
               of lime/ac requirement.

  COSTPHT = (1,016)($82)

  COSTPHT = $83,312
(12) Cost of light grading earthwork.

  COSTEW = (TLARLG)(LGEWCST)

  where:
  COSTEW  =  Cost of earthwork grading, $.
  TLARLG  =  610ac.
  LGEWCST=  $1,359/ac.

  COSTEW = (610)($1,359)

  COSTEW = $828,990
(13) Cost of onsite mobile sludge application vehicles.
                             MSECI
  COSTMAV = (NOV)(COSTPV)
                              990.8
  where:
  COSTMAV =  Cost of onsite mobile sludge appli-
               cation vehicles, $.
  NOV      =  8.
  COSTPV  =  $185,000 from Table 16-6.
  MSECI    =  Current  Marshall and Swift Equipment
               Cost Index at time of analysis is 990.8.
  COSTMAV = (8)($1 85,000)
  COSTMAV = $1 ,480,000
(14) Annual cost of operation labor.

  COSTLB = (L)(COSTL)

  where:
  COSTLB  = Annual cost of operation labor, $/yr.
  L         = 10,971 hr/yr.
  COSTL    = Cost of operation labor, $22.97/hr.

  COSTLB = (1 0,971 )($22.97)

  COSTLB = $252,004
(15) Annual cost of diesel fuel.

  COSTDSL = (FU)(COSTDF)
  where:
  COSTDSL =  Annual cost of diesel fuel, $/yr.
  FU       =  44,132 gal/yr.
  COSTDF  =  Cost of diesel fuel, $1.09/gal.

  COSTDSL = (44,132)($1.09)

  COSTDSL = $48,104
(16)  Annual  cost of maintenance for onsite mobile
sludge application vehicles.
  VMC = [(HSV)(HPD)(DPY)

  (MCSTCAP)/(VHRCAP)]
where:
VMC      =

HSV      =
HPD      =
DPY      =
MCSTCAP =
VHRCAP  =
MSECI    =
               Annual cost of vehicle mainte-
               nance, $/yr.
               50,147 gal/hr.
               8 hr/day.
               120 days/yr.
               $9.45/hr from Table 1 6-7.
               6,545 gal/hr.
               Current Marshall and Swift Equip-
               ment Cost  Index at time of analysis
               is 990.8.
  VMC = [(50,147)(8)(120)($9.45)/(6,545)]

  VMC = $69,509
                                   990.8
                                   990.8
(17) Annual cost of maintenance for land application site
(other than vehicles) including monitoring, recordkeep-
ing, etc.
                                                    SMC = [(TLAR)(16)]
                    ENRCCI
                    5,445.83
  where:
  SMC

  TLAR
  16
  ENRCCI
            Annual cost of maintenance (other
            than vehicles), $/yr.
            2,845 ac.
            Annual maintenance cost, $/ac.
            Current Engineering News Record
            Construction Cost Index at time of
            analysis is 5445.83.
  SMC = [(2,845)(16)]

  SMC = $45,520
                  5,445.83
                  5,445.83
                                              222

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(18) Total base capital cost.

  TBCC = COSTLAND + COSTPHT + COSTEW
  + COSTMAV

  where:
  TBCC     =  Total base capital cost of agricultural
                land application program using onsite
                mobile sludge application vehicles, $.
  COSTLAND =  $0.
  COSTPHT =  $83,312.
  COSTEW  =  $828,990.
  COSTMAV =  $1,480,000.

  TBCC = $0 + $83,312 + $828,990 + $1,480,000

  TBCC = $2,392,302

(19) Total annual operation and maintenance cost.

  COSTOM = COSTLB + COSTDSL + VMC + SMC

  where:
  COSTOM  =  Total annual operation and mainte-
                nance cost for agricultural land
                application program using onsite
                mobile sludge application vehicles, $/yr.
  COSTLB   =  $252,004/yr.
  COSTDSL =  $48,104/yr.
  VMC      =  $69,509/yr.
  SMC      =  $45,520/yr.

  COSTOM = $252,004 + $48,104 + $69,509 + $45,520

  COSTOM = $415,137/yr.
16.7 References

Chemical engineering. In: Marshall and Swift equipment cost index.
  September 1994. 101(9).

Engineering news record. In:  ENR construction cost index. Septem-
  ber 5, 1994. p. 96.

Oil and Gas Journal. September 12, 1994. p. 109.

U.S. EPA. 1985. Handbook:  Estimating sludge management costs.
  EPA/625/6-85/010. Cincinnati,  OH.

U.S. EPA. 1979. Process design manual for sludge treatment and
  disposal. EPA/625/1-79/011. Cincinnati, OH.
                                                 223

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                                           Appendix A
                                          Case Studies
This appendix presents four cases studies illustrating land application at agricultural, forest, and reclamation sites.
The case studies include:

• Madison Metropolitan Sewerage District (MMSD), Madison, Wisconsin. The MMSD applies approximately 20
  dry  tons of sewage sludge per day to  private farmland. Reprinted from Document Long-Term Experience of
  Biosolids Land Application Programs, Water Environment Research Foundation, 1993.

• Metro Wastewater Reclamation District (MWRD), Denver, Colorado. The MWRD produces 70 dry tons of sewage
  sludge per day, which are either applied  to agricultural land or composted and sold to the public. Reprinted from
  Document Long-Term Experience of Biosolids Land Application Programs, Water Environment Research Foun-
  dation, 1993.

• The  Municipality of Metropolitan Seattle (Metro), Seattle, Washington. Metro has applied sewage sludge to
  private forest land, with 19,000 dry tons applied to date. Reprinted from The Future Direction of Municipal Sludge
  (Biosolids) Management: Where We Are and Where We're Going, Proceedings, Volume 1, Water Environment
  Research Foundation, 1992.

• Venango County, Pennsylvania, Abandoned Mine Land Reclamation. Sewage sludge was  applied in a single
  application at a rate of 184 mg/ha.

These case studies provide valuable insights into design, operation, monitoring, public relations, and other aspects
of programs representing a  range of sizes and geographical locations. It should be noted that, in some cases, these
programs will need to make minor operational changes to achieve compliance with the Part 503 regulation.
                                                225

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 MADISON METROPOLITAN SEWERAGE DISTRICT,  MADISON, WI

 Contact Person:      David S. Taylor
                    Madison Metropolitan Sewerage District
                    1610 Moorland Road
                    Madison, WI  58713
 Phone Number:      (608) 222-1201
 Average flow:                37 mgd
 Design capacity of WWTP:      50 mgd
 Dry tons of biosolids/day:       20
 Type of biosolids:             anaerobically digested
 Biosolids management options:   land application
 Application method:            injection
 Started application:            1974

 5.1          Program Overview

 Wastewater treatment at the Nine Springs WWTP started in 1933.  Until 1942, anaerobically
 digested biosolids was air dried and applied to farmland as a fertilizer/soil conditioner. Because
of the manpower shortage during World War II, the system was abandoned in favor of a lagoon
storage system.   In 1974, after evaluating  several alternatives,  the  Madison Metropolitan
Sewerage District (MMSD) decided to begin land applying the  biosolids to private farmland.

Currently all biosolids produced at the Nine Springs Wastewater Treatment Plant (WWTP) are
land applied. The design capacity of this activated biosolids treatment plant is 50 mgd.  Current
flow is around 37 mgd.  About 15% of the wastewater comes from industrial sources. The raw
sludge is  stabilized by anaerobic digestion, and the resulting biosolids are marketed to farmers
                                         226

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 through the Metrogro™ Program. Current biosolids production is approximately 20 dry tons per
 day.  The MMSD is also removing biosolids from the lagoons, resulting in a 50 percent increase
 In the quantity ot biosolids land applied.

 Biosolids are thickened by gravity  belt thickeners to  approximately 6% total solids.   The
 thickened solids  are transported directly to land application, to off-site storage  lagoons, or to
 storage lagoons located adjacent to the treatment plant. Prior to off-site transport, the thickened
 or dredged biosolids are pumped to a 100,000 gallon holding basin at the truck loading station.
 The biosolids dredged from  the lagoons  have a total solids concentration between 4 and  5
 percent. From the holding basin the  biosolids are pumped to a 50,000-gallon elevated loading
 well from which biosolids can be pumped to the transport trucks.  After a truck is  loaded  any
 spilt biosolids are washed off using the on-site washing facilities that are available at  the loading
 site.  The MMSD owns six transport trucks, three mobile storage tanks,  and four  application
 vehicles.

 Liquid biosolids  are transported to the land application site using 5,500-gallon vacuum trucks
that are compatible with the weight limits on the local roads.  The trucks discharge the biosolids
into a 12,000-gallon  mobile storage tank  located at the  application site.  A 3,500-gallon
application vehicle withdraws biosolids  from the storage tank, and injects them 6 to 8 inches
beneath the soil surface. Figure 5-1 shows  a typical storage tank and application vehicle.

Two trucks normally supply one storage tank and application vehicle. The use of the storage tank
has resulted in a 25%  increase in productivity.   Usually the storage tank stays in one place
during the application to minimize the size of the staging area.  After the application is complete,
the staging area is  tilled  to counteract the compaction caused by  the truck  traffic.   One
application vehicle is  capable of spreading biosolids over  8 to 10 acres during  a 10-hour
operating period. The biosolids  injection vehicles have been modified by increasing the number
of injection shanks to  6 per vehicle,  and by adding a drag behind the injectors to smooth the
disturbed soil as shown in  Figure 5-2.  During the application season the vehicles return to the
treatment plant only for major repairs.
                                            227

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Figure 5-1.  Storage tank and application vehicle.
Figure 5-2.  Application vehicle.
                                         228

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The MMSD has permits for 250 to 300 farms to apply biosolids or approximately 30,000 acres
of permitted land with 3,000 to 4,000 acres used annually.  Biosolids are applied at agronomic
rates ranging  from 3 to 5 dry tons per acre per year depending on the crop.  The biosolids
cumulative loading on the field included in this study (site 22, Field 2) is approximately 80 dry
tons per acre.  Field corn is the primary crop, but other crops include sweet corn, soybeans,  and
alfalfa (at seedbed preparation).  No minimum size has been established for fields; however the
MMSD prefers to use large fields to help reduce operating costs. The average transport distance
is about 13  miles,  while the maximum distance is 22 miles.

During peak application periods, i.e. spring and fall, biosolids are applied 10 to 12 hours per day,
6 days per  week.   Contract operators,  under MMSD supervision, are employed to assist the
MMSD, and truck  traffic becomes heavy with as many as 100 truckloads hauled every day. This
truck traffic can generate numerous complaints from  the public.   Participating farmers have
expressed concern over the use of contractors during the  peak application  season.   Most
contractors  use five-wheeled application vehicles, which the farmers feel cause more soil
compaction  than the MMSD's four-wheeled application vehicles.

The MMSD is closing both the on-site and off-site storage lagoons, except for a portion of the
on-site lagoons which will be retained for emergency storage. Concurrently with  the lagoon
closure plan, the MMSD is constructing tank storage facilities for 18 million gallons of biosolids
or for  180 days at  maximum monthly design  flow.

The MMSD uses  a computerized  recordkeeping and tracking system  for all aspects of its
Metrogro  Program.  The MMSD works closely with the  Wisconsin Department  of Natural
Resources (WDNR) to ensure that reports are formatted to ensure a fast and efficient transfer of
information  to the  regulating agency.
                                          229

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5.2           Monitoring

As shown in Table 5-1, the monitoring program includes sampling and analyses of biosolids,
soil, crop/tissue/grain, and groundwater. Samples of biosolids are collected from each truck and
combined into a daily composite sample. The daily composite is analyzed for total solids, total
kjeldahl nitrogen and ammonia nitrogen. Weekly and monthly composite samples are made from
the daily composites. The monthly samples are analyzed for the parameters in Table 5-1. A full
priority pollutant analysis is conducted once each year.

Surface soil samples (0 to 6 inch depth) are collected from each field when the site is initially
permitted with the WDNR.  Active application sites are resampled every three years.  The surface
soil samples are used to determine crop nutrient requirements, as well as the soil cation exchange
capacity (CEC) and soil pH. Where necessary, the MMSD requires that farmers lime fields to
meet the minimum soil pH  requirement of 6.5 that is  specified by the WDNR.

Deep core (4 feet) soil  samples and plant tissue samples are collected from representative soil
types encountered in the Metrogro program. These samples are analyzed for the parameters listed
in Table 5-1.  Deep core samples are collected from these soil types prior to the initial biosolids
application, and every three  years thereafter. These samples are used to evaluate whether metals
are moving from the zone of incorporation.  Plant tissue samples are collected from these sites
every three years, and the metal concentrations are compared to available risk-based criteria.

Groundwater samples  are  collected from private wells  located near land application sites.
Approximately 750 private wells are sampled each year.  The samples are analyzed for nitrate,
chloride, sulfate, coliform bacteria, and zinc.  Results of the groundwater analyses are provided
to the well owner.
                                            230

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                         Table 5-1
Parameters Monitored by Madison Metropolitan Sewerage District
Parameter
Total Solids
Total Volatile Solids
PH
Cation Exchange Capacity (CEC)
Total Kjeldahl Nitrogen (TKN)
Ammonium-Nitrogen
Nitrate-Nitrogen
Phosphorus
Potassium
Cadmium
Chloride
Chromium
Copper
Nickel
Lead
Zinc
PCB (lagoon)
Arsenic
Molybdenum (lagoon)
Selenium (lagoon)
Pesticides
Phenol
Tetrachloroethylene
Trichloroethylene
Vinyl Chloride
Ascaris
Coliform
Salmonella
Biosolids Soil Crops Groundwater
X
X
X X
X
X
X
X X
X X
X X
XXX
X
XX X
XXX
XXX
XXX
XXX X
X
X
X
X
X
X
X
X
X
X
X X
X
                            231

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                                       Table 5-2
                  Average Concentrations in MMSD Digested Biosolids
Parameter
pH
Total Solids
TKN
Ammonium-Nitrogen
Phosphorus
Potassium


Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
1989
7.4
2.2
10.6
5.5
2.8
1.0


4.1
15.0
96.6
683
145
6.7
18.4
46.2
2.9
1,200
1990
7.5
4.8
8.2
3.2
2.5
0.7
.

6.9
13.1
107
671
152
8.1
18.9
46.7
5.3
1,250
1991
7.5
5.5
7.5
2.1
2.6
0.6


4.7
11.2
71.5
634
133
5.9
15.3
45.4
8.2
1,060
1992
7.6
5.7
7.4
2.0
2.6
0.7


3.7
13.7
81.6
609
134
4.8
12.2
42.9
6.3
1,040
The deep core soil, plant tissue, and groundwater monitoring programs are not required by the
WDNR.  They are conducted on a voluntary basis by the MMSD in an effort to increase both
farmer and the general public's confidence in the Metrogro program. Soil and plant samples have
also been collected from a number of test sites, with controlled, replicated biosolids applications.

5.3           Results

Table 5-2 lists the average digested biosolids quality.  The values for the lagooned biosolids are
similar.  Of the organics tested, only bis-(2-ethylhexyl) phthalate was above the detection limit
and measured 6.3 mg/kg.   Although  bis-(Z-ethylhexyl)  phthalate is  a common laboratory
contaminant and was found in some of the blanks, it is commonly found in biosolids. Parameter
                                          232

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 concentrations in biosolids are currently below the Pollutant Concentration limits of 40 CFR
 Part 503.

 Figures 5-3 through 5-5 show the soil concentrations for cadmium, nickel, and lead, at different
 soil depths on site 22, Field 2. The metal concentrations in the soil do not appear to be well
 correlated  with  the  loading.   Nickel  concentrations  in  the  soil  are  declining;  cadmium
 concentrations stay fairly constant in the surface soil, but are declining in the subsoil; and lead
 concentrations in the surface soil increased much faster than would be expected from the loading
 but show little change in the lower soil layers.

 The plant uptake of metals was investigated by the MMSD through a field experiment with three
 replications.  Fertilizer, biosolids at agronomic rates, and biosolids at twice the agronomic rates
 were  applied to the field.  Table 5-3 shows the cumulative metals loadings for the three test
 fields and the soil concentrations at the conclusion of the study in 1987.  Corn was grown,  and
 samples were taken from ear leaf and grain tissues. Results from the ear leaf analyses are shown
 in Table 5-4.  Significant increases  in the zinc and cadmium and decreases in the  copper
 concentrations could be detected in the ear leaf tissues.  Grain tissue concentrations were always
 significantly lower than ear leaf concentrations.

 The groundwater monitoring results have shown a trend  for  increasing nitrate and chloride
 concentrations over time.  The lack of background data for coliform bacteria in many wells made
 it  difficult to  evaluate changes in  water quality  relative  to  this  parameter.  A  long-term
 groundwater monitoring study was  initiated  by  the MMSD in  1982 to compare  groundwater
 quality trends at Metrogro application sites  to sites where commercial fertilizers and  animal
 manures were used.  The  study found no significant difference in groundwater quality trends
 between sites where Metrogro was used and sites where commercial fertilizers/animal manures
were used.  Thus, while the farming  practices seem  to impact the groundwater, the impact from
Metrogro applications seems to be no different than the impact of traditional farming practices.
                                            233

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        2.5n
          77  78  79  80 81   82  83  84  85  86  87  88
                                Year
Figure 5-3.  Cadmium concentrations in the soil on site 22, Field 2.
                                                               -*• 0-10 inch
                                                               -'-10-24 inch
                                                               -*- 24 - 48 inch
                                                               -*- 0-10 inch
                                                               -1-10-24 inch
                                                               -*- 24 - 48 inch
          77  78  79  80  81  82  83  84  85  86  87  88
                                Year
Figure 5-4. Nickel concentrations in the soil on site 22, Field 2.
                                       234

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                                                           -*- 0-10 inch
                                                           -i-10 -24 inch
                                                           -*- 24 - 48 inch
             77 78  79  80 81  82 83  84  85 86  87  88
                                Year
     Figure 5-5.  Lead concentrations in the soil on site 22, Field 2.
                                   Table 5-3
 Cumulative Metals Loadings and Soil Test Levels for Plant Uptake Study
Treatment

Fertilizer
Biosolids
Biosolids 2X

Fertilizer
Biosolids
Biosolids 2X
Cd

0
1.31
2.62

0.27
0.63
0.81
Cr

N/A*
N/A
N/A

17.2
19.2
24.1
Cu
Cumulative Loading fib/acre)
0
30.6
61.2
1987 Soil Test (mg/kg)
16.8
23.9
29.4
Ni

0
3.0
6.0

13.8
14.2
15.7
Pb

0
12.5
23.9

23.7
25.9
28.1
Zn

0
97.1
194

95
113
134
f Data not available.
                                       235

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                 Table 5-4
Metal Concentrations in Corn Ear Leaf Tissue
Year



.78
79
80
81
82
83
84
85
86
87

78
79
80
81
82
83
84
85
86
87

78
79
80
81
82
83
84
85
86
87
Cd



0.13
0.22
0.14
0.15
0.22
0.18
0.18
0.10
0.19
0.06

0.17
0.28
0.41
0.31
0.43
0.27
0.30
0.17
0.27
0.09

0.20
0.48
0.70
0.41
0.52
0.36
0.33
0.23
0.31
0.14
Cr



0.51
0.63
0.39
0.44
0.51
6.48
3.60
2.03
1.72
1.02

0.62
0.68
0.41
0.56
0.67
6.41
3.91
2.00
1.81
1.42

0.54
0.51
0.44
0.52
0.66
4.78
6.33
2.00
1.86
2.13
Cu Ni
- mg/kg (dry weight)
Fertilizer
13.8
12.4
14.7
13.0
16.8
10.2
12.4
10.8
11.0
7.6
Biosolids
13.1
11.8
14.0
12.3
14.2
10.0
11.4
9.6
11.2
8.0
Biosolids 2x
13.8
12.5
14.7
12.3
14.6
9.3
11.5
10.2
11.8
8.2




0.87
1.00
0.75
1.08
1.31
5.27
3.24
1.75
1.13
0.93

0.64
0.85
0.67
0.97
1.35
5.76
3.45
1.69
1.18
1.05

0.57
0.72
0.68
0.88
1.36
4.45
5.27
1.68
1.27
1.55
Pb



0.86
0.93
0.63
0.82
1.74
0.78
0.66
0.53
0.20
0.24

0.94
1.06
0.76
0.79
1.98
0.69
0.57
0.69
0.20
0.20

0.91
0.91
0.62
0.77
1.94
0.50
0.50
0.59
0.22
0.23
Zn



67.5
79.5
80.0
88.8
125.5
66.0
50.0
54.0
47.0
39.8

68.7
79.0
79.5
132.
152
57.5
49.0
59.5
46.5
47.8

65.5
91.0
105.5
172.5
167.0
66.0
47.5
65.8
57.5
60.3
                   236

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 5.4           Public Relations

 Public relations and education are critical to the success of the MMSD's Metrogro program. The
 MMSD has sought to include the public in the planning and design of the Metrogro system.
 Questionnaires were distributed to farmers to determine their  interests,  concerns, and farming
 practices.  Equipment  demonstrations were held, and feedback was sought from farmers, local
 officials, and the public.  Farmers were interested in having equipment  that would incorporate
 residuals  into the  soil,  and they preferred high  flotation  tires that would help reduce soil
 compaction.   Local officials were concerned about road damage from heavy truck traffic.  The
 cleanliness of the applications was of concern to both homeowners and  farmers.

 One of the first steps taken in the Metrogro public education effort was  to avoid the use of the
 term "sewage sludge" because of its negative connotations.  A contest was held to  select an
 alternative term. The reus    ogram became known as the "Metrogro Program" and the biosolids
 were referred to as  "Metrogro".  A logo was developed to help identify the "Metrogro Program".

 The MMSD  attends town  meetings  and sponsors farmer meetings to explain the benefits and
 limitations of the environmental monitoring program, the wastewater treatment processes, and the
 land application program.  Tours of the treatment plant are  given to interested parties.  Public
 demonstration plots comparing Metrogro and commercial fertilizer treatments were established
 and maintained.

 The local news media are kept informed about the project and its activities. The relationship with
 the media continues to  be favorable. Articles in local newspapers and farm publications generally
 promote the Metrogro program.

The perception that Metrogro is a resource rather than a waste product was  fostered  by
establishing a fee for the biosolids application.  Over the years increases in the fees have been
made.  The fee is currently $7.50 per acre. The fertilizer N-P2O5-K2O value of the biosolids is
                                            237

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around $35 in fertilizer savings.  This value was calculated for 64, 120, and 14 pounds of N,
P2O5, and K2O/ton using $0.20, $0,23, and $0.12 for N, P2O5, and K2O respectively.

Other activities  and publications the MMSD has developed to educate the  public and farm
community include the following:

       +      Informational brochures.
       $      Letters to farmers  once or twice  a year,
       *      A slide show for public meetings and school demonstrations.
       4      Periodic farmer meetings.

The private groundwater testing program has also become a part of the outreach program.  A
representative of the treatment plant contacts the landowners on a regular basis. Complaints and
concerns about the  program are likely to be discussed with the representative and can be dealt
with in a constructive manner.

Farmer acceptance  of the Metrogro program seems to rest on the following factors:

       $      Keeping the application equipment clean and neat to project a professional image.
       $      Trying to minimize the compaction of soil by keeping the staging area in the field
              as small as possible.
       $      Using a storage tank  in the field to provide a buffer between the trucking and
              application of biosolids, increasing the efficiency of the operation.
       $      Employing experienced operators, who can minimize mistakes during the land
              application.
       4      Being willing to do a  little extra  work to leave the field in a  condition that helps
              the farmer with his operation.
       $      Maintaining a  constant  presence  in the  community,  so that  the  program is
              associated with the activities of the city, like garbage pickup or street cleaning.
                                           238

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 5.5           Summary

 The MMSD has been applying biosolids  from its Nine Springs WWTP on privately  owned
 farmland since 1974. The Nine Springs WWTP produces approximately 20 dry tons of biosolids
 per day. An existing lagoon storage system allows the MMSD to store biosolids during periods
 when inclement weather and agricultural practices prevent land application. New storage tanks
 are being constructed, and  a portion of the existing  lagoons  is being closed.  The new tank
 facilities should provide storage capacity  for 180 days of biosolids production at maximum
 monthly flows.

 Anaerobically  digested  biosolids  are thickened to  approximately  6 percent prior to  land
 application.  The MMSD uses its own equipment to transport  and apply biosolids on a regular
 basis; however, contractors are used to supplement the MMSD's operations during peak periods.
 Biosolids are injected at  agronomic rates that typically range from 3 to 5 dry tons per acre per
 year.  Total cumulative biosolids loading on the site evaluated  is approximately 80 dry tons per
 acre, equivalent to 16 to 27 years of consecutive agronomic applications.

 One of the unique aspects of this program  is the use of a storage tank in the field to decouple
 the transport and application of biosolids.  Using storage tanks in the field has increased the
 MMSD's productivity by about 25%.

A comparison of soil metal loadings and soil metal test values show that the two parameters are
not well correlated.  For example, lead concentrations in the surface soil increased faster than
would be expected from  the loading.

Field experiments were conducted by the MMSD to evaluate plant uptake of metals.  Under the
controlled conditions, significant increases in zinc and cadmium  concentrations could be detected
in corn ear leaf tissue.
                                           239

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The MMSD's groundwater monitoring program has shown a trend for  increasing nitrate and
chloride concentrations over time.   However, a study comparing the groundwater quality at
Metrogro sites  to sites where commercial fertilizers and animal manures arc used showed that
the impacts  from Metrogro applications appear to be no  different than the impacts  from
traditional farming practices.

The MMSD credits its extensive public relations efforts and willingness to work with farmers for
the success of the program. The public is not only regularly informed about the program's status
through the news media and public  meetings, but  the MMSD also involves the public in the
planning and design of the program.  For example, the public was actively involved  in the
selection of equipment and the Metrogro logo.  The perception that biosolids are a resource rather
than a waste is fostered by charging  a fee for the biosolids application.
                                           240

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  METRO WASTEWATER RECLAMATION DISTRICT, DENVER CO

 Contact Person:      William J. Martin
                     Metropolitan Denver Sewage Disposal Dist. No. 1
                     6450 York Street
                     Denver, CO   80229
 Phone Number:      (303) 289-5941
 Average flow                 150 mgd
 Design capacity               185 mgd
 Dry tons of biosolids/day        70
 Type of biosolids              anaerobically digested
 Biosolids management options    land application and composting
 Application method            injection/surface application followed by incorporation
 Started application             1979

 6.1           Program Overview

 The Metro Wastewater Reclamation District (MWRD) began processing wastewater at the Central
 Plant in 1966. The agricultural land application program was established in 1979. The MWRD
 currently processes 150 mgd at its Central Plant, which has a design capacity of 185 mgd. The
 plant provides primary and secondary treatment using the activated sludge process to provide
 nitrification-denitrification.  Primary and secondary  sludges are combined  and stabilized by
 anaerobic digestion.   The treatment plant produces  about 70 dry tons  per day of digested
 biosolids. The digested  biosolids are thickened or dewatered using centrifuges. The dewatered
biosolids are either applied to  agricultural land or  composted and sold to the public under the
name METROGRO™. The charges for the METROGRO™ products at the time of this study
are:
                                           241

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        4      $1.75 per 1.25 cubic foot bag of fine-screened compost.
        4      $19.00 per ton for fine-screened compost.
        4      $13.00 per ton for coarse-screened compost.
        4      $3.00 per acre for thickened or dewatered biosolids.

 About 10% of the biosolids produced is currently composted, and the remaining 90%  is applied
 to land. While composting is more expensive  than land application, the MWRD maintains the
 composting facilities to enhance the  flexibility and reliability of the program.   During the
 preparation of this report, the MWRD purchased approximately 10,000 acres of land. Use of this
 site will reduce the need to obtain permits from local jurisdictions for privately-owned farmland
 and allow  MWRD to manage the entire agricultural program.

 The MWRD began applying biosolids  to privately-owned farmland in 1979.  The biosolids are
 thickened to approximately 8 to 9 percent total solids prior to being transported to the application
 site in 7,000-gallon tank trucks.  The MWRD owns eight tank trucks like  the one  shown in
 Figure 6-1.  The  biosolids are injected 6 to 12 inches beneath the soil surface by one of three
 injection vehicles. Two of the injection units have a capacity of 7,200 gallons and the third one,
 4,000 gallons.

 Later,  the  MWRD  began  surface  application  of dewatered biosolids to improve  the cost-
 effectiveness and  flexibility of the program.  Dewatered biosolids can be applied during the
 winter months when subsurface injection is impossible.  The dewatered biosolids are transported
to the application site in 45  cubic  yard tractor/trailer trucks and discharged into a temporary
holding area at the application site.  The holding area is a  three  sided earthen pit (similar to a
bunker silage pit), that will be restored  when the application has been completed. A front-end-
loader is used to load the biosolids into  one  of three 22-cubic yard,  custom-built surface
spreaders.  The biosolids are usually not stockpiled overnight at  the application site because of
the  odor potential.  However, if they must remain in the loading pit overnight, soil is used to
cover the biosolids.
                                            242

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Figure 6-1.  Biosolids tanker truck.
                                       243

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Spreaders were custom built to provide a more even application of biosolids than commercially
available spreaders. The MWRD's spreaders have a metering screw and gauge that allow the
operator to obtain a more even application than could be obtained with commercial equipment
and the MWRD's biosolids.  In addition, the MWRD installed a heating system on the spreader
box, which allows  for spreading of biosolids during the winter months.

Following surface application, the solids are incorporated into the soil by disking and plowing,
as shown in Figure 6-2. The MWRD supplies the labor and tillage equipment. In some cases,
minimum tillage  (para-tilling)  is  required  by  the  U.S. Department  of Agriculture Soil
Conservation Service (SCS) to minimize erosion potential. The Agriculture Stabilization and
Conservation Service  (ASCS)  and SCS are  also beginning, through  contingencies on farm
subsidies, to encourage certain  tillage practices.  To facilitate application during the  winter,
sufficient land  is prepared to allow application of 90 days' biosolids production.  Construction
plows pulled  by a tracked  tractor are  used  to  incorporate the  biosolids  during the  winter.
Although the MWRD prefers to surface apply dewatered biosolids, it continues to use subsurface
injection on sites in developed areas to avoid odor complaints.

Biosolids application rates are based on the recommended nitrogen loadings for the intended crop,
and the plant available metal concentration in the soil.  The most common  crops  grown  on
biosolids-amended soils are dryland wheat and irrigated corn.  In 1992, the MWRD had permits
for approximately 18,000 acres of dryland wheat, and 5,000 acres of irrigated corn land. Average
winter wheat yields have increased from 40 bushels per acre without biosolids to 65 bushels per
acre after biosolids application.  Corn is grown for both silage and grain. Annual application
rates range from 1 to  3 dry tons per acre (50 to 75 pounds of nitrogen per acre) for dryland
wheat, and from 5 to  10 dry tons per acre (about 300 pounds of nitrogen per acre) for corn.
Based on these rates, biosolids are applied to 1,900 to 19,000 acres annually. The  exact acreage
depends on the mix between dryland and irrigated fields used.  Other crops that have been grown
on biosolids-amended soils  include milo, oats and barley.
                                           244

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  . -„-•-% 7  . .^--;?*r?T  :^:*  •'•*•
                                                         -*
Figure 6-2.   A field after biosolids application and incorpor-
             ation.
                            245

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The MWRD had approximately 150 permitted sites at the time of this study. Transport distances
vary widely from approximately 30 miles to as much as 150 miles one-way.  Of the 150 sites,
24 are at least 90 miles away. One of the primary reasons for the long transport distances is the
difficulty in obtaining permits from local jurisdictions.

In selecting application sites,  the MWRD follows the criteria established by  the  Colorado
Department of Health. In addition to the state permits, the MWRD is required to  obtain county
permits for sites in Adams and Wells Counties.  More than 50 percent of the MWRD's permitted
sites are located within Adams County. Approval of a site in Adams County is  contingent on
SCS approval. A number of sites used in the past have been denied renewed permits because
the SCS had concerns about the suitability  of sandy soils for application. The primary concern
is that sandy soils could pose an  increased risk for leaching of nitrate and other constituents.

Permitting fees are charged by  the state and the county.  The state currently charges $2.40 per
dry ton of biosolids applied, while the County  fees are approximately $0.50 per dry ton.  In
addition to  the  permit fees, local jurisdictions  often  require a 24  to 48-hour  notice before
biosolids can be applied to specific sites.

6.2           Monitoring

Soil samples are taken from each site prior to the application of biosolids and tested for nutrients
using Colorado  State University  tests.  Both  total and extractable metal  concentrations are
determined. DTPA extraction is used to measure available metals in the soil.  Soil samples are
stored for one year.  Crop samples are collected at harvest.  Biosolids are sampled from the
loading area during the land application.  The District  works with the  U.S.  Geological Survey
(USGS) to monitor the groundwater at a selected site, which is assumed to be representative of
all of the application  sites.  The parameters monitored  are summarized in Table 6-1.
                                           246

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                        Table 6-1
Parameters Monitored by Metro Wastewater Reclamation District
Parameter
pH
Electrical Conductivity (EC)
Cation Exchange Capacity (CEC)
Organic Matter (OM)
Total Volatile Solids
Total Kjeldahl Nitrogen (TKN)
Nitrate-Nitrogen (NO3-N)
Ammonium-Nitrogen
Phosphorus
Available Phosphorus
Potassium
Available Potassium
Aluminum
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Iron
Lead
Mercury
Manganese
Molybdenum
Nickel
Selenium
Silver
Zinc
Available Cadmium
Available Copper
Available Iron
Available Lead
Available Nickel
Available Zinc
Polychlorinated Biphenyls (PCB)
Asbestos
Fecal Coliforms
Soil
X

X
X


X
X
X
X

X




X

X
X
X



X


X
X
X
X
X
X
X



Biosolids Crops
X


X
X X
X X
X
X
X

X

X
X
X

X X
X
X X
X X
X X
X

X
X X
X
X
X X






X
X

Groundwater
X
X


X

X
X
X







X
X
X
X
X

X

X


X








X
                           247

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6.3           Results

Table 6-2 shows the composition of the thickened digested biosolids. The concentrations of
most metals and nutrients have been fairly constant during the past 10 years.  Lead concentrations
show a downward trend over the last decade, while zinc, nickel, and cadmium remain unchanged
as shown in Figure 6-3. The biosolids have concentrations less than the Pollutant Concentration
limits of the 40 CFR Part 503 regulations  for  all  elements  except molybdenum; but the
molybdenum concentration is well below the  Ceiling Concentration of 75 mg/kg.

Table 6-3 and Table  6-4 show the soil analysis  from two sandy loam fields.  Field 88 had
received 53 dry tons of biosolids per acre over an 8-year period, while Field 89 had received 42
dry tons per acre.  Tables 6-5 and 6-6 show  the amount of biosolids and the concurrent metal
loadings applied to these two fields.

The  usable site-life of these  fields  is going to be limited by  zinc  or copper.  On the sites
examined, the concentration of organic matter  has doubled since the biosolids application began.
This should enable farmers to reduce the application of water to amended  fields, although no
water use data are available to  verify  this. The increase in organic matter might account for the
higher yields on the biosolids-amended soils.

The total and available phosphorus levels in the soils at Fields 88 and  89 increased significantly
during the  study period, as shown on Tables 6-3 and 6-4.  For example,  on Field 88 the total
phosphorus level increased from 210 to 505 mg/kg,  and the available phosphorus level increased
from 19 to  100 mg/kg. This increase  is in response to the application of about 2,900 pounds per
acre  phosphorus over a 10 year period. Only  about one-fifth of the applied phosphorus can be
detected in the soil, but a TKN digestion is used to determine total phosphorus content. This type
of digestion does not solubilize all of the phosphorus in the system.
                                           248

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                                       Table 6-2
         Average Concentrations in the Metro Wastewater Reclamation District
                                   Digested Biosolids
Parameter
PH
EC («raho/cm)
OM
TKN
NH4-N
NOj-N
Phosphorus
Potassium


Aluminum
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Mercury
Molybdenum
Nickel
Selenium
Silver
Zinc
PCB
1983
7.4
6,980
N/Af
8.33
2.83
0.08
2.35
0.49


6,950
0.09
24.9
276
675
30,400
344
9.9
18
98
<0.01
110
1,500
N/A
1984
7.3
12,600
N/A
8.28
4.48
0.02
3.13
0.50


9,080
1.55
28.0
N/A
826
18,000
445
10.5
67
124
0.09
N/A
1,500
<1.0
1985
7.7
4,130
N/A
7.5
2.24
<0.01
2.7
0.42


20,000
0.29
18.0
212
670
19,900
270
5.2
36
76
<0.08
92
1,400
<1.0
1986
8.0
9,960
32
7.0
3.00
0.01
2.12
0.30


6,890
3.0
12.1
123
535
14,900
203
3.0
8.5
69
3
53
1,220
<1.0
1987
7.8
6,900
N/A
4.9
1.08
<0.01
3.4
N/A


7,350
4.2
7.2
86.9
1,130
18,200
189
4.1
10
135
5.1
57
1,040
<1.0
1988
7.4
6,900
or..
N/A
6.2
2.38
<0.0l
2.35
0.30
n.
nig/kg - — •
11,000
0.0
9.1
137
566
18,200
180
3.8
19
64
10
115
1,130
<1.0
1989
7.8
15,300
62.1
9.4
2.87
<0.01
2.23
0.33


10,900
9.2
9.5
165
829
31,000
210
4.2
28.3
114
3.3
86
1,450
<1.0
1990
7.8
15.300
64.1
9.5
2.87
<0.01
2.23
0.33


10,900
9.2
9.5
165
829
31,000
210
4.2
28.3
114
3.3
86
1,450
<1.0
1991
7.8
15,300
64.1
9.5
2.87
<0.01
Z23
0.33


10,900
9.2
9.5
165
829
31,000
210
4.2
28.3
114
3.3
86
1,450
<1.0
1992
7.9
11,800
67.7
7.7
3.13
0.01
2.32
0.39


8,920
6.0
12.0
114
622
26,600
165
3.0
30
54
7
95
1,010
<1.0
* Data not available.
                                          249

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     10,000
                                                                   Cadmium
                                                                -*- Nickel
                                                                -*-Zinc
           83  84  85  86   87   88   89   90   91   92
                                 Year
Figure 6-3.  Pollutant concentration trends (1983-1992).
                                     250

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                                      Table 6-3
Soil Analysis for Field 88
Parameter
PH
CEC (meq/lOOg)
OM (%)
EC Cumoh/cra)
1982
7.4
6.5
0.60
380
1983
7.8
6.1
0.60
329
1984
6.6
8.7
0.80
420
1985
6.5
9.4
0.83
295
1986
6.6
7.0
0.80
368
1987
6.6
7.0
1.01
568
1988
6.5
6.0
0.62
426
1989
7.7
14.6
1.28
520
1990
7.1
12.9
1.60
468
1992
7.0
13.8
1.24
516
Total Concentrations frac/ke}
Phosphorus
Cadmium
Copper
Iron
Lead
Nickel
Zinc
210
N/A
5.0
N/Af
N/A
N/A
27
210
0.08
3.5
6,500
7.5
4.0
24
290
0.20
8.5
10,600
10.0
8.0
42
325
1.32
4.8
6,920
13.9
4.4
27
446
1.40
9.4
8,380
20.0
6.8
40
490
0.80
9.0

20.0
5.9
44
610
0.30
6.7
7,960
20.0
5.3
38
560
0.20
9.0
10,200
40.0
7.8
55
580
0.20
10.0
9,760
24.0
6.1
56
505
0.49
7.0
7,770
27.0
4.2
47
Available Concentration fmeAg)
NO,-N
NH,-N
Phosphorus
Cadmium
Copper
Iron
Lead
Nickel
Zinc
7.4
N/A
19.0
0.05
0.52
N/A
0.94
0.26
1.2
14.2
N/A
28.2
0.08
0.86
16
0.94
0.24
1.5
8.9
N/A
57.2
0.12
2.78
24.8
1.6
0.64
3.98
4.0
N/A
50.8
0.15
2.77
30.6
1.18
0.92
4.34
3.8
N/A
59.8
0.16
3.49
30.2
1.32
0.59
5.39
23.0
3.6
81.0
0.17
4.92
35.8
1.31
0.9
6.91
6.3
2.2
67.0
0.74
4.02
37.2
1.4
0.66
5.18
19.5
3.0
108
N/A
N/A
N/A
N/A
N/A
N/A
20.0
4.7
101
N/A
N/A
N/A
N/A
N/A
N/A
9.6
2.9
52.4
N/A
N/A
N/A
N/A
N/A
N/A
'  Data not available.
                                          251

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                                   Table 6-4
                           Soil Analysis for Field 89
Parameter
pH
CEC meq/lOOg
O.M. %
NOj-N rag/kg
NH.-N mg/kg
EC moh/cm
1982
6.5
12.6
0.43
10.4
N/A*
N/A
1983
7.4
8.3
0.82
1.2
N/A
N/A
1984
1986
7.0 6.5
7.4 6.7
0.62 0.73
11.6
N/A
N/A
4.6
N/A
N/A
1987
6.9
6.3
0.85
11.6
28.6
465
1988
6.5
5.0
0.57
2
2.2
197
1989
7.4
14.3
1.21
10.6
1
198
1990
7.4
6.1
0.63
Z4
1.38
224
1991
6.5
10.1
1.24
7.4
2.10
251
Total Concentrations (mg/kg)
P
Cd
Cu
Pb
Ni
Zn
Fe
230
N/A
7.6
N/A
N/A
42
N/A
330
0.2
6.5
6.2
5.8
34
8,000
310
0.2
12
12
6.5
42
9,250
567
1.93
6.7
20
5.8
33
6,970
400
0.5
7.0
20
5.3
31
6,320
620
0.6
6.2
17
4.8
31
490
1.5
12
27
9.3
56
6,790 10,915
340
0
3.0
10
ZO
20
7,030
486
0.5
15
22
4.7
47
8,760
Available Concentrations (mg/kg)
P
Cd
Cu
Pb
Ni
Zn
Fe
20
0.92
1.1
1.4
0.68
0.56
N/A
21
0.09
1.3
1.0
0.46
2.56
22
59
0.10
2.52
1.42
0.62
3.56
24
64
0.12
2.66
1.03
0.66
3.46
31
69
0.12
4.12
0.99
0.77
5.15
32
55
0.12
3.2
1.2
0.60
3.90
34
120
N/A
N/A
N/A
N/A
N/A
N/A
56
N/A
N/A
N/A
N/A
N/A
N/A
61
N/A
N/A
N/A
N/A
N/A
N/A
*  Data not available.
                                       252

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                                      Table 6-5
                              Annual Loading to Field 88
Year

1983
1984
1985
1986
1987
1988
1989
1990
Total
Biosolids

9.0
6.4
6.0
8.4
7.3
11.5
5.2
4.6
58.4
Cd

0.38
0.26
0.21
0.21 /
0.13
0.23
0.08
0.08
1.5
Cu

13.7
8.02
7.07
9.86
2.66
12.7
5.61
4.4
64.0
Pb

5.94
3.65
3.24
3.59
0.96
4.13
1.63
1.43
24.6
Ni

1.88
1.16
0.69
1.13
0.44
1.65
0.74
0.39
8.08
Zn

25.6
18.2
15.6
19.9
6.9
24.6
10.8
8.7
130
P

421
401
323
356
496
551
195
181
2924
                                      Table 6-6
                              Annual Loading to Field 89
Year

1983
1984
1986
1988
1990
Biosolids

9
5
7
18
7
Cd

0.38
0.24
0.19
0.43
0.13
Cu

15.8
5.32
8.23
17.3
6.99
Pb

7.42
2.56
3.21
6.05
2.28
Ni

1.81
0.85
1.19
2.27
0.63
Zn

28
11.7
16.7
36.5
13.9
P

381
275
242
201
290
Total
46
1.37
53.6
21.5
6.75
107
1,389
                                      253

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With the exception of lead, only a relatively small portion of the added metals could be detected
in the soil.  For the two fields studied, an average of 25 percent of the cadmium, 8.7 percent of
the copper,  81 percent of the lead, 2 percent of the nickel, and 11 percent of the zinc was found
in the soil.   Metal concentrations in the corn tissue on  Field 88, as shown in Table  6-7, are
variable.  The concentrations are similar to those in diagnostic corn tissue  grown on soils not
treated with biosolids.

The MWRD, jointly with the USGS, recently completed a five year groundwater monitoring
program.  The site used in  the study was selected because of its  sandy soils and relatively
shallow depth to  groundwater.  The  program was  to  determine whether the  land application
practices resulted in contamination of the groundwater with nitrates.  Elevated concentrations of
nitrates and higher specific conductance were observed beneath the site; however, the source of
the contamination could not be identified. The use of commercial fertilizers, animal manure, and
biosolids were all considered to be potential sources. Because of the inconclusive results of the
groundwater monitoring  program,  the  MWRD is  beginning a new groundwater monitoring
program at a controlled site where the MWRD will control not only the application of biosolids,
but also the agricultural management of the site.
                                       Table 6-7
                Metal Concentration in Corn Ear Leaf Tissue on Field 88

Year

1984
1986
1987
1988
1989
Cu


3.8
3.6
nd
4
2.6
Ni


10.2
0.2
5.3
2
nd
Zn


19
22
45
60
31
Pb

g/Kg -
<0.2
nd'
6.0
2
nd
Cd


<0.1
0.1
nd
nd
nd
TKN


13,000
13,800
16,300
13,000
12,000
f  Parameter not detectable by the method of analysis.
                                           254

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 6.4           Public Relations

 The MWRD strives to  maintain positive relationships not only with the farmers providing the
 land, but also with the general public. The MWRD works with the farmer to schedule biosolids
 application and tilling operations to meet the farmer's needs and to ensure that the tillage method
 complies with SCS requirements.   Farmers are charged  $3.00 per acre for the biosolids
 application.   The MWRD  has  estimated  that the total value  of this service  to  the farmer,
 including the nutrients  and  tillage, is between $30 and $60 per acre.  In addition, the MWRD
 maintains the roads during application at the farm site.

 MWRD personnel participate in public hearings, respond to  citizen complaints,  and assist with
 the repair of roads damaged by the biosolids trucks. Some counties require a public hearing for
 each permitted site. MWRD personnel respond to odor complaints by going to the source of the
 complaint  and taking  scentometer readings.  The readings are recorded, and any  possible
 mitigation  measures are implemented.   The  number of complaints  in recent  years has not
 exceeded four per year.

 The METROGRO™ name was chosen for the biosolids and the composted biosolids to provide
 a name free of the negative  connotations associated with "sludge".

 6.5           Summary

The land application program, which has been in operation since  1979, is  the primary method
of biosolids utilization by the MWRD.  While a portion of the biosolids produced are handled
through a composting and distribution program, land  application  remains  the primary method
because of its cost-effectiveness. Recently, the MWRD has encountered difficulties in permitting
sites in nearby townships and counties and has been forced to transport biosolids to sites  as far
as 150 miles away.  The MWRD has recently purchased land for a biosolids application site
because of these problems.
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Biosolids are either injected or surface applied and incorporated in the soil.  Typical application
rates are between 3 and 8 dry tons per acre.  Cumulative biosolids applications after eight years
are currently between 30 and 60 dry tons per acre. Review of available biosolids quality data
shows that most metal  and nutrient concentrations over the last eight years have remained
relatively constant.  Cadmium, lead, and nickel concentrations have decreased, probably as a
result of industrial  pretreatment.

Concentrations of extractable metals in the soil remained constant through the last 10 years.  One
exception was  lead, which showed a slightly increasing trend. Total and available phosphorus
increased,  and the  organic matter content of the  sandy  loam soil  doubled.  The increase in
organic matter could  be  expected to reduce the demand for irrigation water. Plant tissue data
showed no increase in the plant uptake of metals.

The  results of past  groundwater monitoring at the District's test site were inconclusive because
the District was unable to control  the  management of the privately-owned site.  Although
elevated nitrate levels were observed, commercial fertilizers, animal manures, and biosolids were
all believed to have contributed to the contamination.
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                      FERTILIZING FORESTS WITH BIOSOLIDS:
          HOW TO PLAN, OPERATE, AND MAINTAIN A LONG-TERM PROGRAM
                                      Peggy Leonard
                                   Forestland Coordinator

                                       Roberta King
                            Research and Monitoring Coordinator

                                        Mark Lucas
                            Senior Land Reclamation Coordinator

                                Sludge Management Program
                             Municipality of Metropolitan Seattle
                              821 Second Avenue, Mail Stop 81
                                    Seattle, WA  98104
INTRODUCTION/PROGRAM HISTORY

The Municipality of Metropolitan Seattle (Metro) has a program of beneficial use of its biosolids in
composting, agriculture and forest fertilization projects.  Metro's land application program began in
the early 1970s, with a proposal from the University of Washington to study the potential benefits of
wastewater sludge as a fertilizer of commercial forests of the Puget Sound area. The first ten years of
research by the University focused on application technology, environmental effects, and growth
response. After determining that sludge greatly increased tree growth on nutrient-poor soils and
could be applied safely with no detrimental public health or environmental effects, the University and
Metro moved on to larger-scale demonstrations.

In 1985, Metro conducted operational-scale applications on some of its own forestland in the county.
After that, two timber-growing companies and the state department of natural resources signed
agreements with Metro for applications on their own lands. The most suitable sites for sludge
application, both from a technical and public access standpoint, were found on one of the companies'
lands. Metro staff concentrated their efforts on developing a project with that landowner, the
Weyerhaeuser Company.

Metro is now in its sixth year of operations on Weyerhaeuser lands with over  19,000 dry tons of
biosolids applied. The program has been'Successful for both biosolids generator and landowner, but,
as with any ongoing program, has had its share of the unexpected.  As Metro now begins working
with farmers in agricultural uses of biosolids, we are using many of the "lessons learned" from
forestry in how to work with the landowner and the public, and how to manage operations and
maintain quality control.

In this paper, the authors will describe how Metro has developed its program  with this landowner,
how application sites are designed and operated, and the standards of performance that we feel are
necessary for successful long-term operations.
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WHY FOREST APPLICATION?

Technical Reasons
(1) The soils need nitrogen and organic matter.
The soils in the Puget Sound area are glacially derived, composed of deep layers of gravel and sand
deposited by glaciers that moved into Washington from the north. They are young on a geological
timescale, and so lack the reserves of organic matter and minerals found in older, more developed
soils.  Forest soils of the entire region are generally deficient in nitrogen.

(2) Forest fertilization with nitrogen is a well-known industrial practice.
Some of the large industrial landowners have established programs of fertilizing both natural stands
and plantations with chemical nitrogen fertilizer in the form of urea. Thus, the concept of routine
fertilizing to produce faster growth in trees is not new in the Northwest.

(3) The most important commercial  tree species grows faster with biosolids.
Early research with a variety of Northwest tree species demonstrated that Douglas-fir trees had the
best growth response to sludge.  Douglas-fir  is the most important commercial tree in the Pacific
Northwest.  Most private timberland owners  in our region grow Douglas-fir on a cycle of 45 to 50
years, replanting and managing it in single-species plantations.  Since the 1960s, Douglas-fir has been
fertilized with nitrogen. But research showed that growth response to biosolids exceeded the
response  from urea.

(4) The climate and terrain near Seattle allow nearly year-round operations.
The maritime climate is characterized by mild, wet winters and cool, dry summers.  In the lowland
forests east of the city, precipitation averages about 60 inches per year, with average daily
temperatures of 40 degrees in the winter and 60 degrees in the summer. Light snow may occur
December through February, with accumulations averaging less than 6 inches. The gravelly forest
soils are well-drained and can withstand the impact of ground equipment, even during the wet
winters.

Location and Land Use/Ownership Patterns
Other cities may find, like Seattle, that  if large tracts of foresdand are close to the city, they are a
logical and feasible choice for biosolids management.

The population centers of western Washington are located along Puget Sound. East of the cities is the
broad, rolling to level plain occupied by commercial forests and rural communities, but with
encroaching suburban development. Further east, about 75 miles from Seattle, are the foothills and
mountains of the Cascade Range. Most of the state's agricultural areas (grains and fruit) are located
over the mountain passes on  the eastern side  of the Cascades, where the climate is much drier.

Several forest products companies have large timber holdings in the glacial plains immediately east
and within 30 miles of the Puget Sound cities (Seattle, Tacoma, Oiympia). Although these forests are
open to the public for hunting, they are "Working" forests with a great deal of harvesting activity and
log truck traffic.  These large contiguous tracts have a well developed network of gravel roads and
access that is controlled through a few main gates. These characteristics, plus the remoteness from
residences, make these areas well suited for use of biosolids.

Transportation Cost
The close-in location reduces the cost of hauling biosolids from the treatment plants. Metro's hauling
costs are from $9  to $10 per wet ton (23% solids) for forest sites, while agricultural sites are generally
about 200 miles from the treatment plants and average $25 per ton for hauling. As seen in Figure  1,
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 however, total haul and application costs for the two uses are comparable due to the ease of
 application in agricultural fields.


 OPERATIONS ON THE SNOQUALMDE TREE FARM

 In 1985, Metro and the Weyerhaeuser Company signed a 2-year agreement for the utilization of
 Metro's biosolids — trademarked Silvigrow — on the company's Snoqualmie Tree Farm,
 approximately 30 miles east of Seattle.  The tree farm encompasses 170,000 acres, most of it in one
 large contiguous block. The application of Silvigrow to selected areas would supplement the
 company's urea fertilization program. The first Silvigrow project, 160 acres of 5-year-old trees, was
 begun and successfully completed in 1987.  After two years of projects, the agreement was renewed
 for another two years and then in early 1991, a ten-year agreement was signed.

 Metro has the responsibility for site selection, design, permitting, operation and monitoring. Site
 design and operating plans are subject to company approval, particularly with respect to haul and
 transfer routes within the private road system of the tree farm.  Weyerhaeuser retains the responsi-
 bility for managing the timber to meet its corporate objectives. What follows is a discussion of how
 Metro plans and operates its fertilization projects on this tree farm.

 Site Selection
 Careful site selection is essential for producing the best growth response.  Listed below are the most
 important factors that we consider when choosing candidate sites.  Initial screening is done in Metro's
 office with topographic maps, soil maps, recent aerial photos and the landowner's inventory records.
 A careful walk-through of each potential site is necessary to confirm the suitability of the soils and
 terrain. See Figure 2 for the checklist that we develop for each site that is inspected in the field.

 • Terrain - gentle
 For ground application, equipment is limited to slopes of 30%, and ideally, slopes of 15% or less.
 Federal and state guidelines recommend rolling to level sites, with only short stretches of slopes at
 30%. We've found that sites with a slight tilt or those with some variable topography are preferable
 to those "flat-as-a-pancake" sites, where drainage problems can develop.

 Slope allowances for forestry sites are considerably higher than those  allowed in agriculture. This is
 due to the excellent infiltration capacity of the forest floor and, in young stands, the amount of herbs
 and shrubs in the understory whose foliage intercepts the biosolids and aids in stabilizing and drying.

 • Soils - well drained
We target soils that have a high content of gravel and sand and minimal amounts of clay. These soils
work best for two reasons: (1)  they can withstand the impact of the loaded applicator vehicles, even
during wet winter weather.  To apply a full prescription of biosolids usually requires many passes. If
the soils are too fine-textured, the applicator vehicles can create deep ruts and mud. In our
experience, trail rutting is one of the "hot buttons" for the timberland owner. The owner wishes to
preserve and enhance the long-term productivity of his lands, and rutting destroys the fertile upper
horizons of the soil.  (2) coarse textured soils are low in nutrients and need extra nitrogen and organic
matter. The best growth response to biosolids are on sites of this medium to poor quality.

• Vegetation -  well stocked and the right height
Height of the trees  is a critical factor.  Early research by the University of Washington demonstrated
that when biosolids is applied to very young  plantations, there are several undesirable results: (1) if
not controlled  by herbicides, understory plants will respond rapidly and compete with the tree
seedlings for water, nutrients, and light;  (2) the heavy herbaceous growth leads to population growth
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 of small rodents who will chew on and girdle the tree seedlings; (3) the amount of damage to the
 seedlings from browsing deer increases, as the deer will preferentially browse on fertilized seedlings
 that are at or below their "browse height" of 4 to 5 feet. To avoid these problems, we apply only to
 plantations that are at least five feet tall and that have a minimum of brushy, unstocked "holes" in the
 plantation.

 • Surface waters - as few as possible
 Sites with many draws, streams and wetlands may require a large proportion of the area in setbacks or
 buffers, thus reducing the net usable area for application. Generally, sites with well drained soils will
 have 30% or less of the area lost to buffers.

 • Road system - suitable width and grade
 Although the tree farm includes plateau, foothills, and mountainous areas from 700 to over 3500 feet
 in elevation, our operations are limited to the lower elevations by  the inability of the  biosolids
 delivery trucks to haul steep grades on gravel roads. Grades cannot exceed 10% for long distances
 and the roads must have frequent turnouts or be wide enough to allow  two  trucks  to pass each other.

 • Seasonal restrictions - no slurry on the foliage in dry season
 Liquid or rewatered Silvigrow at 7 to 15% solids cannot be applied over the foliage of trees during
 the growing season, since the summers in the Pacific Northwest are relatively dry. There is no rain to
 wash the foliage, and the biosolids become cemented onto the foliage. (Metro is currently testing
 equipment that applies biosolids as dewatered cake.  This type of application may minimize the
 amount of biosolids clinging to the foliage and so may be suitable for summer use. More on this later
 in the paper.)

 • Project size
 The minimum parcel size that allows continuous operations is dependent upon the time required for a
 layer or lift of Silvigrow to stabilize. A typical rate of 10 DT/ac is applied  in three separate lifts with
 drying time after each application. During the wet season, a lift requires three to four weeks to
 stabilize. If Silvigrow can be applied at the rate of 40 acres per week, then  160 acres of working area
 is required to keep operations continuous for 4 weeks. By that time the first areas to be applied would
 be stabilized and ready for the second lift. The entire 160 acres would be completed in 12 weeks.

 Design Factors
 The first steps in confirming the initial assessment of a site are a soil evaluation and an assessment of
 the ground water conditions.  These tasks are performed by University soil scientists and
 hydrogeology consultants, respectively.  See Figure 3 for the sequence of steps in designing and
 permitting a site.

 To design each project, Metro employs contract foresters who are  knowledgeable  in the best
 management practices of biosolids application. During a thorough examination of each proposed
 unit, they eliminate areas that are too steep, too wet or that might be pathways for water movement
 during rainstorms. Boundaries of the usable area are marked in the field with fluorescent pink
 flagging. Then they design a trail system of parallel, looping or dead ended trails which will allow
 the applicator vehicle to completely reach all the usable areas. We achieve  slightly overlapping, even
 coverage by applying into a compartment from trails on either side.  The spacing between trails varies
 from 185 to 200 feet, depending on the height and density of the trees.   See Figure 4 for an example
of a trail system that covers a 98-acre site.

 Streams in or adjacent to the application area are buffered by non-application strips of varying widths.
We use the following guidelines: 200 feet from large, continuously flowing streams,  100 feet  from
small tributary streams, and 50 feet from ephemeral drainage ways. The purpose of the buffer is to
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 provide a safety margin if an operator were to overshoot the boundaries or if Silvigrow were to move
 during a rainstorm. The width of these buffers is far greater than actually needed.  Since beginning
 operations on this tree farm, we have had no significant movement of Silvigrow away from an
 application area, primarily for two reasons: sites are heavily covered with vegetation, and the
 practice of applying in thin layers works well to stabilize the Silvigrow.

 The development of an appropriate application rate is an essential part of the design process.
 Researchers from the University of Washington inspect all proposed forest sites and recommend an
 agronomic rate.  The variables in this calculation are: estimated annual uptake of nitrogen for tree and
 understory species, mineralization rate for the organic nitrogen in the biosolids, soil storage capacity,
 and estimates for volatilization and denitrification.  With the total nitrogen in our biosolids averaging
 about 5%, a typical application rate for a 10-year-old plantation is around  9 dry tons per acre. Our
 current plans are for a 4 to 5-year cycle of reapplication.

 Because Metro's biosolids are treated by a PSRP (Process to Significantly Reduce Pathogens) rather
 than a PFRP (Process to Further Reduce Pathogens), site access is restricted for 12 months after
 application.  Yellow plastic signs are posted around the site boundaries every 100 to 200 feet:
                                Municipality of Metropolitan Seattle
                                    & Weyerhaeuser Company
                          SILVIGROW APPLICATION BOUNDARY
                       Trees in this area are being fertilized with Silvigrow - biosolids from
                       Metro wastewater treatment plants. Any health risk to humans is
                       from eating soil during the first year after Silvigrow application.
                       Therefore, federal regulations restrict public access for one year.

                         Access Limited Until	
                              For morv infortnition, call Metro Witor Ouality Communications
                                            91684.1138.               .
                                                                     -tm A
Permitting Process
In the state of Washington, the state Department of Ecology has delegated permitting authority for
biosolids to local health districts. For this particular project, the Seattle-King County Department of
Public Health is the regulator and permitting authority. We are fortunate to have local regulators who
are knowledgeable about biosolids practices and research as well as the draft federal regulations.
Permitting of new areas on the tree farm has gone smoothly because of the projects' remoteness, low
public profile, and good monitoring results.

Following the submission of the permit application package (which includes description of soil
profiles, analyses of soils for metals and nutrients, chemical analyses of biosolids, topographic maps
of application areas, hydrogeology study, monitoring plan, calculation of application rates, and
proposed trail layout), the regulator makes a field visit with the project manager and field designer for
the project.  Representatives from the state Department of Ecology attend whenever possible. The
field inspection usually focuses on the buffering and protection of water bodies and other sensitive
areas as well as any downstream water users.  The entire permitting process can usually be completed
in 45 days, the minimum review period required by county regulations.
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 Operations Tracking
 Metro's current forest operations involve the addition of water to dewatered cake biosolids to produce
 a slurry of 7 to 15% solids which is then sprayed onto the trees. The mixing/delivery station at the
 tree farm is located in a large gravel pit. Here the haul trucks unload biosolids (at 18 to 27% solids)
 into an in-ground mixing tank to which dilution water is added. The diluted biosolids, called
 Silvigrow, are then pumped into adjacent storage tanks for the day's application. Usually 4 to 5
 truckloads of 30 wet tons each can be processed and applied in a day.

 The application units are usually located in a 3-mile radius from the mix station, so transfer tanker
 trucks are used to shuttle Silvigrow from the mix station out to the working applicator vehicles. The
 applicator vehicle is a rubber-tired, articulated, four-wheel drive chassis with a 2200-gallon tank
 mounted over the rear axle. The tanks contain an internal pumping system driven by the power take-
 off connected to a one-inch diameter nozzle mounted on top of the vehicle.  The loaded applicator
 vehicles travel into the forest on the trail system; they are stationary as the operator applies the
 material, controlling the direction  and trajectory of the spray from a joystick inside the vehicle cab.

 Each operator has a clipboard with a map of the application unit and a logbook (see Figure 5). Each
 application unit is divided into compartments of 1 to 6 acres which are used to keep track of the
 actual amount of Silvigrow applied. For example the application rate for Unit 24-08-02 is 8.5
 DT/acre.  Compartment 22 in this unit is 1.1 acres,  which would require 1.1 X 8.5 = 9.3 DT to
 complete.  Each applicator applies 1 DT per load, so 9 loads total would be needed for this
 compartment. Applying this amount in three separate lifts means that 1 complete lift consists of 3
 loads. The logbook is marked to show when each lift is completed.

 At the end of each day, the site supervisor checks the condition of trails and the buffers for all the
 compartments that were applied that day. Records of these checks (see Figure 6) are kept at the field
 trailer at the mixing station for the Metro site manager's inspection.

 Contingency Plans
 Metro and the application contractor have developed a set of procedures for responding to any
 incidents on the site.  An "incident" may be a spill, surface runoff, traffic accident, work site accident,
 misapplication of biosolids or any other site  problem. The operations plan includes a contingency
 plan, which outlines the individuals to be contacted  in case of a large-scale incident.  The plan also
 includes a list of local contractors and their equipment (dump trucks, loaders, vacuum trucks, tow
 trucks, and cranes) that could be called for assistance. Small spills or misapplications are corrected
 immediately, and an Incident Report form (developed by Metro) is filed. We have had some trucking
 incidents but no large spills in the 6 years of operation.

 Monitoring
 Water Quality - To evaluate the water quality of streams near Silvigrow sites, Metro establishes test
 sampling stations downstream from project areas and control stations upstream.  Two types of
 monitoring are conducted:  (1) Routine or ambient - conducted on a quarterly basis before, during,
 and for three years following applications; and (2) Storm - occurs during two to three rainstorms in
 the wet season following application. Storm sampling is conducted to ensure that Silvigrow is not
 being carried offsite by surface runoff.  All samples  are grab samples, collected by water quality
 specialists with Metro's Environmental Laboratories. Samples are analyzed for ammonia nitrogen,
 nitrate-nitrite nitrogen, fecal coliforms, and enterococcus. Six years of sampling have shown little to
 no significant changes in the excellent water quality in these streams.

There are no drinking water wells within a mile of any site, and most of the sites do not overlie
aquifers of any significant size.  For these reasons, we do not use ground water wells in our
monitoring program. Two of our sites, however, have installations of tube lysimeters. Nitrate data
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 collected from the lysimeters is used by the University of Washington to fine-tune their model and
 assumptions of nitrogen uptake in Douglas-fir stands.

 Tree Growth - Many of the application areas at the tree farm contain growth plots. To maintain
 consistency in data collection, all growth plots are installed and measured by field crews from the
 Stand Management Cooperative (SMC). (The SMC is a cooperative of universities and landowners
 that sponsors integrated research in forest nutrition, silviculture, and wood quality.) Not all areas
 have these plots; we install them whenever there is an opportunity to gather data from different soil
 types or age classes of timber. The standard installation consists of three tenth-acre square plots
 treated with biosolids and three control (no biosolids) plots in the same stand. All trees are numbered
 and tagged; height and diameter are measured annually. Results from  the first three years of
 operations in young stands indicate increases in annual height increment can range from 20 to 75%
 over controls.

 Partnership with the University
 Metro has continued its contract relationship  with the University of Washington College of Forest
 Resources since 1973, not only for research but for design assistance on operational sites.  As
 described in previous sections of this paper, researchers from the U.W. are an essential part of site
 design. They make a field visit to each proposed application area to evaluate the suitability of the soil
 to receive biosolids and to sustain traffic. They estimate the nutrient needs of the site and prescribe
 the appropriate application rate. They propose research to fill in the knowledge gaps, monitor the
 growth response, and assist us when something goes wrong.  We know that their role is one of the
 critical factors in the long term success of this project.

 Other municipalities have developed this kind of partnership with research institutions. Some
 examples are Greater Vancouver Regional District with the University of British Columbia, City of
 Spokane with Washington State University, Massachusetts Water Resources Authority with the
 University of Massachusetts,  and Vail, Colorado with Colorado State University.

 Performance Standards
 Many of the operating practices that have been developed over the past six years of operations at the
 Snoqualmie Tree Farm have been formalized and incorporated into a set of standards that is now
 applied to all other kinds of biosolids projects. In any given month, Metro may deliver biosolids to
 two or three kinds of projects.  Each site may be operated by a different contractor, and even
 permitted by different counties. Last year when one of the contractor-managed soil improvement
 sites came under public scrutiny for failing to closely follow the operations plan, the sludge program
 staff developed common performance standards to which  all projects would conform.  These
 standards would ensure that all projects receiving Metro biosolids would operate with the same
 attention to detail, regardless of the local requirements. The new standards gave Metro a visible and
 active role during the permitting and operating of the project. Listed below are some of the key
 requirements that have worked well on forestry sites and are now required of all other projects as
 well:
 • Operations plan with detailed site maps;
 • Haul route approved by Metro;
 • Agronomic application rates reviewed by university or other independent specialists;
 • Buffers and boundaries clearly marked in the field;
 • Good housekeeping measures at the site with daily inspections of boundaries and buffers;
 .• Pre- and post-application monitoring of soils, surface water, and, if appropriate, ground water and
crops.
 • Public information plan with early and ongoing public involvement opportunities;
 • Contingency plan for any incidents;
• Quarterly and annual reports to be produced and available for any  interested parties.
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WHEN SOMETHING GOES WRONG

Despite careful planning and site management, Murphy sometimes visits our projects. For the first
two years the Metro/Weyerhaeuser projects went smoothly; a total of 1200 acres had been permitted
and completed. Then scattered trees began to yellow and droop on one of the fertilized areas.
Scientists from the University of Washington College of Forest Resources began an investigation into
the source of the problem, which was obviously related to the biosolids application as adjacent
unfertilized areas were unaffected. Over the next few months, the clumps of dying trees totaled about
40 acres.

The research team concluded that the trees weakened because of inadequate soil aeration. This lack
of oxygen was caused by a combination of site conditions and the slow drying characteristics of
secondary biosolids under these conditions. The very flat terrain and shallow soils restricted winter
drainage,  while the dense tree canopy kept the ground cool and shaded so that the biosolids did not
dry. Under these conditions, the biosolids sealed the soil surface, reducing the movement of oxygen
into the soil.

Weyerhaeuser forest scientists were consulted and involved in the investigation at every step, so there
was consensus among Metro, the University and the landowner that we had a developed a problem
that could be easily avoided in the future by focusing on young, open stands. The affected areas were
harvested prematurely and Metro paid Weyerhaeuser for the value of the lost growth. Applications
resumed the next year and are continuing.


CRITERIA FOR SUCCESS

• Find your niche in the landowner's overall management plan.
Niche, from the science of plant ecology, is defined as "the ultimate unit of the habitat, i.e. the
specific spot occupied by an individual; the more or less specialized relationship existing between an
individual and its environment." Forest landowners in Washington state have a multitude of laws,
restrictions and regulatory agencies to deal with.  We want the use of biosolids to be an easy practice
to implement on their tree farm and one that requires minimal investment of staff time for them.
Metro staff handle all the site development and permitting for Silvigrow projects and work hard to
minimize  any "hassle factor" for the landowner.

We also have found a place in the landowner's current management regime. Weyerhaeuser presently
begins urea fertilization around age 17 and continues on 7 year intervals through the entire rotation of
45 to 50 years.  Silvigrow fertilization begins around age 5 and is reapplied on 5 year intervals.  This
provides a real boost to developing plantations and allows the trees on these poorer-quality sites to
grow at a rate typical of much more productive sites.

•  Hold your projects to the highest standards. There are many obvious reasons to run a clean, well-
managed operation. But it's essential if you're counting on a long-term relationship with a particular
land owner and his  community.

•  Be actively involved and visible to the public and the landowner. As the biosolids generator, you
will find it to your benefit to be visible, accountable, and responsive to your "customers". It
eliminates confusion about who is responsible for the quality of the application and any perceived
liability. Other types of projects with Metro's biosolids have been permitted and managed by private
vendors/contractors. Whenever issues or problems arise, the public usually looks beyond the vendor
to the generator for explanations or satisfaction of their complaint.
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 • Make projects a team effort with the landowner, contractor, scientists and community. There is no
 substitute for the support of your local research institution and the local newspaper editor/writer. The
 researchers will provide a check and balance for your operation plans, keep your projects on sound
 technical footing, and help with the problems that will surface.  We found that working with and
 establishing an open relationship with the local editor from the very outset of the Snoqualmie project
 ensured that we had more reasonable and informed coverage when problems did arise.

 • Monitor and publish results, both water quality and crop response.
 Let the world know what a good job you're doing — talk, talk to community groups and professional
 organizations. Presentations to the local SAP (Society of American Foresters) chapter or other
 industry group will go a long way toward informing the forestry community in your locale about the
 opportunities with biosolids.


 PLANNING FOR THE NEXT DECADE

 New Products. New Equipment
 1992 is a year of transition and testing for Metro's forestry program. In addition to the current
 rewatered applications, this year we will be testing the feasibility of dewatered cake applications. In
 April and May we pilot-tested a side-cast spreader unit that flings dewatered material 200 feet out
 into the plantation. This type of application could extend operations into the summer and allow us to
 access areas of the tree farm that are only operable during the dry season. Such an operation would
 also reduce costs by eliminating the need for dilution water and reducing crew size from five to two.

 Later this year Metro's first dried biosolids product will become available through a contract for
 biosolids drying with PCL/SMI. Metro  will be testing some of this material in its existing forestry
 and irrigated agriculture projects.

 More Efficient Planning and Permitting
 During the first two years of operations on the Snoqualmie Tree Farm, we concentrated on choosing
 suitable sites for the upcoming year, doing a good job with operations, and following up carefully and
 accurately with monitoring results and reports. Now with a new ten-year contract, plus two new
 forms of biosolids product becoming available to us this year, we face the challenge of a more long-
 term planning approach.

 Our goals are to:
 • predict number of acres and locations that will be available each year over the next decade;
 • reduce amount and redundancy of staff and consultant work.

 To accomplish the  first goal, Metro staff are currently working on a screening process for the entire
 tree farm. We are making field visits to  all areas that have the potential to use liquid, cake, or dried
 biosolids. Using the information gathered with the checklist in Figure 2, we will be developing a
 database of stands that can be sorted by a number of variables: location, tree age, soil type, season
 of application, and type of fertilizer product.

 Permitting and environmental reviews to date have been somewhat piecemeal. Each project area of
 160-200 acres has been evaluated and permitted separately, with separate operations plans and
 individual reports of soils and ground water.  To bring some continuity to the program and to
 streamline our permitting efforts, this year we are developing two documents (in  three-ring binders)
 that can be  used for all projects: (1) an operations plan for the entire tree farm, with site maps and
 specific permit conditions located in appendices; and (2) a hydrogeology study for the tree farm,
again with site-specific studies added as needed.
                                             265

-------
 Research Needs
 For the next couple of years, Metro and the University of Washington will be focusing on: further
 fine-tuning of application rates, including the effects of residual nitrogen and multiple applications;
 expansion of operations to other forest types such as hybrid cottonwood plantations and mixed
 conifers in eastern Washington; and research on the fate of nutrients other than nitrogen.

 One of the most exciting developments of the 1990s is the startup of similar forestry programs in
 other parts of the US and the world. We're watching with great interest what's happening in
 Vancouver, British Columbia; Christchurch, New Zealand; eastern Massachusetts, eastern Australia
 and elsewhere.

 For the biosolids generator, forest application can provide a type of reuse that has a reasonable cost,
 is non food-chain, remote from homes, and provides economic benefits for the user. For the land-
 owner, the use of biosolids can result in faster-growing trees,  greater timber volumes, and long-term
 improvements in productivity. With the information and operational experience gained by Metro and
 other forest fertilization programs, more POTWs may find that forest fertilization is the right option
 for their biosolids.

 Acknowledgements
 Although there have been many people who have helped shape the Silvigrow program, the authors
 want to recognize three who "made it happen":  Steve Anderson, area forester for the Weyerhaeuser
 Snoqualmie Tree Farm; Charles Nichols, who designed the Silvigrow application/transfer equipment
 and is now with the Sanitary District of Orange County,  California; and Suzanne Schweitzer, who
 developed the framework for designing and managing these projects and is now with East Bay
 Municipal Utility District.

Any correspondence or questions can be addressed to: Peggy Leonard, Municipality of Metropolitan
 Seattle, 821 Second Avenue, Mail Stop 81, Seattle, WA  98104-1598.
                                            266

-------
                                                  m HAUL
APPLICATION
           45  -T-
           35  —
           30  --
       rj  20 -p
       o
           15
           10  -r
            5  —
                      COMPOST
                                         FORESTRY
                                                           AGRICULTURE
                                                            (Yakima)
         AGRICULTURE
           (Adams)
AGRICULTURE
 (Douglas)
Figure 1. Approximate haul and application costs for compost, forest, and agriculture projects (by wet tons averaging 23% solids).
                                                        267

-------
                                          FIELD CHECKLIST
       DATE OF FIELD CHECK:
       FIELD EXAMINER: 	
       LOCATION: (Section, Township, Range)
         Attach map with boundaries marked.
       SOILS
         Information Source:.
         Soil Series:	
            PROPERTY OWNER:.
            ELEVATION:	
                                                     NUMBER OF ACRES:.
                                                     NEARBY SITES:	
         Parent Material:.
         Approx. Depth:_
           .Does soil appear suitable?.
       TOPOGRAPHY
        Slope:	
        Presence of draws (mark on map):	
        Areas where slope may be critical factor (mark on map):.
       SURFACE WATERS
        Water body type and location (mark on map):.
        Areas of poor drainage (standing water, wet-site indicators);
        Buffers required (mark on map):.
       VEGETATION
        Tree species:.
        Stocking levels:_
        Understory:
       .Average stand height:.
                         Species
Average Height
Average Cover (nearest 10%)
      ACCESS
        Main Roads:  Grade:.
                    Width:
     Overall Condition:
        Any Limitations for Application Trails:.
      COMMENTS/RECOMMENDATIONS:
      ESTIMATE OF USABLE ACRES:	
      RECOMMENDED SEASON OF APPLICATION:,
Figure 2.  Field checklist for evaluation of potential Silvigrow sites.
                                               268

-------
        Site Design
          and Permitting
            for Silvigrow Sites
  Select Sites
                                            Collect and Analyze
                                              Soil Samples
                Hydrogeology
                Assessment
                                     Design and
                                        Mark
                                     Trail System
   Prescribe
Application Rates
  (Univ. of WA)
  Begin Background
Water Quality Monitoring
                                                             Operations
                                                                Plan
                                                            Environmental
                                                               Review
                                 Prepare and Submit
                                 Permit Application
                         Review of Application by
                       County Health Department and
                         State Dept. of Ecology
                              Site Visit
                                                                Construct Trails
                                                                    Survey Trails for
                                                                  Compartment Acreage
                                                                      Prepare As-Built Maps;
                                                                  Calculate Compartment Loadings
                                                                            Hang Boundary and
                                                                            Compartment Signs
         Municipality of Metropolitan Seattle
                                4/92
                                                                                  Begin Operations
Figure 3.  Steps in the design and permitting of forest application sites.
                                                   269

-------
                         Unit 24-08-02
               Weyerhaeuser Snoqualmie Tree Farm
                LEGEND
          Erftflng Roacfe     133O
          and Road Numtwn
          Slop* Bufl*r
          (A/rows point downstofw)
                    400'
                                                                                         To mix station
Figure 4.  Trail map of typical Silvigrow unit. Units are named for the township, range, and section in which they are located—Unit
         24-08-02 is located in T24N R8E, Section 2. This particular unit comprises 98 acres.
                                                       270

-------
                                              Application Log
 I   = IME
 A  = Ag Chem
-~~ = End Lift
/*"















/
I
F
Load
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Date
Y/^Y
Jlu
4ju






f^AJf)_






17
18
19
20
21
22
23
24
25
26
27
28
29 1
30
31
32






Time
/.or
//••
-------
                      DAILY BOUNDARY AND BUFFER CHECK
         Inspector
Date
         UNITS WORKED TODAY
Unit/
Compartment





























# Passes Tire Depressions Standing
per Day 0-6" 6-12" 12-18" Stuck Water








Trails (General conditions, incl. any Silvigrow on trails)






Buffers (Note any oversprays, spills, etc.)






Compartments (Application uniformity)






Figure 6.  Field sheet for daily boundary and buffer checks by the site supervisor.
                                        272

-------
                       LONG-TERM  EFFECTS OF A SINGLE APPLICATION OF MUNICIPAL SLUDGE
                                         ON ABANDONED MINE LAND1

                                                    BY

                                 William E. Sopper and Eileen M. Seaker2
                           Abstract.  In 1977, digested and dewatered municipal sludge
                       was applied and incorporated in spoil material at a rate of 184
                       Mg/ha on a 0.4 ha experimental plot on an abandoned strip mine
                       site in Pennsylvania.  Data were collected for a five-year
                       period (1977-1981) to determine the effects of the sludge
                       application on the quality and growth of the herbaceous
                       vegetation, the chemical properties of the soil, and the
                       chemical quality of groundwater.  In 1989, 12 years after
                       sludge application, the site was again resampled to determine
                       the long-term residual effects of the sludge application.
                       Results of the re-evaluation indicated that the single high
                       application of sludge facilitated the rapid development of a
                       vegetative cover which has persisted over the 12 years with no
                       apparent adverse effects on vegetation,  soil, or groundwater.

                           Additional key words:   Reclamation,  trace metals,  sludge
                       utilization,  revegetation, groundwater quality.
                     Introduction

     It is estimated that more than 7.7 million dry
 metric tons of municipal sludge are currently
 produced each year by the 15,300 public-owned
 treatment works in the United States.
 Approximately 25% of this is being land-applied for
 its  fertilizer and organic matter value (Federal
 Register 1989).   One of the most efficient  uses for
 sludge is the reclamation of disturbed lands,  such
 as those abandoned after coal mining which  are
 acidic,  droughty,  and devoid of organic matter.
 Sludge has  been  shown to improve  spoil structure,
 water  holding capacity,  and bulk  density in
 addition to adding N,  P,  K,  and other  plant
 nutrients (Sopper  et  al.  1982;  Sopper  and Seaker
 1983).

    Approximately  121,000 hectares of  land  in
 Pennsylvania,  strip mined prior to the  federal
 Surface Mining Control and Reclamation Act of  1977,
were abandoned after  the coal was removed,  leaving
vast areas of barren spoil (USDA 1980).  These
sites have remained barren for years due to the
difficulty of establishing and maintaining
vegetation on the highly acidic material.

    In 1977, a project was initiated in
Pennsylvania that introduced the concept of using
municipal sludge for revegetation of mined land to
the general public in order to gain public
acceptance and support.   The specific objective of
the project was to demonstrate that municipal
sludge could be used, to reclaim strip mined land
and return it to potential agricultural use or to a
wildlife habitat in an environmentally acceptable
manner, without adverse effects on the quality of
the vegetation, soil,  or water.  Vegetation,  soil,
and groundwater samples were collected over a five-
year period (1977-1981)  and results of these
studies have been reported by Seaker and Sopper
(1984) .
                   Paper presented at the 1990 Mining and Reclamation Conference and
                   Exhibition, Charleston, West Virginia, April 23-26,  1990.   The
                   research described in this article has been partially funded by the
                   U.S. Environmental Protection Agency through Grant No.  S-804511-020
                   and CR807408010.
                  2
                   William E.  Sopper is Professor of Forest Hydrology,  School  of Forest
                   Resources,  The Pennsylvania State University,  University Park,  PA
                   16802 and Eileen M.  Seaker is Environmental Consultant, 1917 E.
                   Branch Road,  State College,  PA 16801.
                                                    273

-------
     The issue of the long-term effect of applying
 single, large amounts of sludge in order to
 revegetate mine land often arises.  What happens
 after all the sludge has been mineralized and all
 the nutrients and trace metals have been released
 to the soil and are potentially available for plant
 uptake and leaching?  Will the vegetative cover
 persist or deteriorate?

     One of the sites used in the 1977 project was
 an abandoned strip nine bank located in Venango
 County that had been backfilled and recontoured
 after mining without top soil replacement.   Several
 revegetation attempts were unsuccessful.   Dewatered
 digested sludge was applied in May 1977 to a 0.2-ha
 plot.   In August,  1989, 12 years after sludge
 application,  the site was revisited and samples of
 vegetation,  soils,  and groundwater were collected
 to evaluate the long-term effects.   The project was
 originally designed as a demonstration to the
 public,  rather than an experiment.   Subsampling was
 employed,  but statistical analyses could not be
 performed on the data.   Instead,  general trends are
 discussed.
                Materials and Methods

 Sludge Application

     The surface soil was compacted,  stony,  and
 extremely acid (pH 3.8).  The 0.2 ha plot was
 scarified with a chisel plow to loosen the  surface
 spoil  material and agricultural lime was  applied at
 12.3  Mg/ha to raise the spoil pH to 7.0.   Sludge
 for the project was obtained from three local
 wastewater treatment plants.   The sludge  was
 applied at 184 Mg/ha with a manure spreader.  The
 average concentrations  of nutrients  and trace
 metals and amounts  applied in the sludge  are given
 in Table 1.   The amounts of nutrients applied were
 equivalent to applying an 11 (N)  -9  (F205)  -0 (K20)
 chemical fertilizer at 22,400 kg/ha.


 Table  1.   Chemical  analysis of dewatered  sludge
           applied  and amounts of  elements applied
           at  184 Mg/ha  rate (Dwt  Basis)
Constituent

Total P
Total N
K
Ca
Mg
Zn
Cu
Pb
Ni
Cd
Average
Concentration
mg/kg
4624
12188
93
9970
2082
811
661
349
69
3.2
Amount
Applied
kg/ha
918
2388
18
1834
383
147
129
55
12
0.6
                        7.9
    The amounts of trace metals applied are given
in Table 2 along with the U.S. Environmental
Protection Agency (EPA) and Pennsylvania Department
of Environmental Resources (PDER) interim guideline
recommendations (United States Environmental
Protection Agency 1977; Pennsylvania Department of
Environmental Resources 1977).  It is quite obvious
 that the amounts of trace metals applied were well
 below the recommended lifetime limits except for
 copper, which slightly exceeded the Pennsylvania
 guidelines.

     Immediately after  sludge application and
 incorporation,  the  site  was  broadcast seeded with a
 mixture of two  grasses  (Kentucky-31 tall fescue,  .
 Festuea arundinacea Schreb., 22  kg/ha,  Pennlate
 orchardgrass, Dactvlis  glomerata L.,  22 kg/ha)  and
 two legumes  (Penngift  crownvetch,  Coronilla varia
 L. ,  11  kg/ha, and Empire  birdsfoot trefoil,  Lotus
 corniculatus L.,  11 kg/ha).   Then  the  site  was
 mulched with straw  and hay at the  rate  of 3.8
 Mg/ha.

 Sampling and Analyses

     A complete monitoring system was  installed  on
 the  plot to  evaluate the  effects of the  sludge
 applications on water quality, vegetation, and
 soil.  Two groundwater wells were  drilled  (up-
 gradient and down-gradient)  to sample the effects
 of  the sludge application on groundwater quality.
 After sludge application,  groundwater samples were
 collected bi-weekly for the  first  two months  and
 monthly  thereafter.   Samples were  analyzed for pH,
 nitrate-N by ion-selective electrode  (Ellis  1976),
 dissolved Cu, Zn, Cr, Pb,  Co, Cd, and Ni by  atomic
 absorption spectrophotometry (EPA Methods of
 Chemical  Analysis 1974).

     Minesoil samples were  collected at the 0  to IS,
 and  15 to 30 cm depth,  passed through a 2 mm  sieve,
 and  analyzed for pH, Kjeldahl-N,  Bray-P,
 exchangeable K,  Ca,  and Mg by ammonium acetate
 extraction, and dilute hydrochloric acid
 extractable Cu,  Zn,  Cr, Pb,  Cd, and Ni (Jackson,
 1958).    Exchangeable cation  and extractable metal
 concentrations were  determined by atomic
 absorption.

    At the end of each growing season vegetation
 growth responses were determined by measurements of
 percentage areal cover,  and dry matter production.
 No crops were harvested over  the  12-year period.
 Individual samples of tall fescue,  orchardgrass,
 crownvetch, and birdsfoot trefoil from each plot
were collected for foliar analyses.  Plant samples
were analyzed for Kjeldahl-N; P,  K, Ca,  Mg,  by
plasma emission spectrometry  (Baker et al.  1964),
 and Cu,  Zn, Cr,  Pb,  Co,  Cd, and Ni by atomic
absorption (Jackson  1958) , after  dry ashing and
digestion.
                                                                        Results and Discussion
                                                          Vegetation
                                                              The  site was  completely  vegetated  by  August
                                                          1977,  three  months  after  sludge  application,  which
                                                          has  persisted .throughout  the 12-year period.
                                                          Average  annual  dry  matter production for  the  first
                                                          five years and  in 1989 was as follows:
Year
1977
1978
1979
1980
1981
1989
AHY
Yield
Mg/ha
6.0
9.3
11.3
31.2
22.6
15.5
4.0
                                                     274

-------
                             Table  2.   Trace  metal  loadings  of  Che sludge application
                                       and  lifetime loadings  recommended by the EPA
                                       and  PDER.
Constituent






1
2
Cu
Zn
Cr
Pb
Ni
Cd
Hg
Average CEC
Sludge
Application
184 Mg/ha

129
147
74
55
12
0.6
0.09
of site ranged
No recommendation given by
EPA1
(CEC 5-15)

280
560
NR2
800
280
NR2
from 11.6 to 15.
EPA
PDER

112
224
112
112
22
3
0.6
.2 meq/lOOg

     Dry matter production increased during the
 first four years,  leveling off in 1981.   In 1989  it
 was  slightly lower but still well above  the average
 hay  yield (AHY)  for undisturbed farmland soils in
 the  county.   During the first two years  the two
 grass species dominated the site, but by the third
 growing season,  the two legume species predominated
 and  persisted through the fifth year (1981) .
 However,  by 1989  the birdsfoot trefoil had almost
 disappeared and now the dominating vegetative cover
 consists  mostly of crownvetch and orchardgrass.

     For brevity,  only the foliar analyses  for
 crownvetch and orchardgrass will be discussed.
 Foliar  concentrations of macronutrients  are  given
 in Table  3.   Nutrients (N and P) were all  generally
 higher  in the sludge-grown plants.   Potassium and
 Ca were higher in  the sludge-grown orchardgrass
 than in control plants.   Potassium and Ca  were only
 slightly  lower in  the sludge-grown birdsfoot
 trefoil plants than in the control plants.   Foliar
 Mg concentrations  were similar in both sludge-grown
 and  control  plants.   Nutrient levels  in  the  sludge-
 grown plants  in 1989 were about the same level as
 the  first year when sludge was applied.  There
 appears to be little depletion of nutrients  from
 the  site  over the  12-year period.   Birdsfoot
 trefoil data  are given in Table 3 because  no
 crownvetch plants  were present on the control  plot
 for  comparison.  Macronutrient concentrations  in
 crownvetch on the  sludge-amended plot are  given in
 Table 4.   Concentrations  were  quite  similar  to
 those of  birdsfoot  trefoil.

     Foliar concentrations  of  Zn,  Cu,  Pb, Ni,  and Cd
 in orchardgrass and  crownvetch are  shown in Figures
 1 to  5.   Concentrations of Zn  (Fig.  1), and Ni
 (Fig. 4)  tended to be  higher  in crownvetch than in
 orchardgrass;  whereas,  concentrations  of Cu  (Fig.
 2) tended  to  be higher in  orchardgrass.
 Concentration of Pb  (Fig.  3)  and Cd  (Fig.  5) were
variable  and  showed  no  distinct  trends.  In
 general,  trace metal  foliar concentrations tended
to be highest  the first year and  then decrease over
time.   Except  for Ni,  foliar concentrations of
trace metals  in the  sludge-grown  orchardgrass
plants were higher than in control plants.   The
1989  values for Cu (Fig. 2) and Cd  (Fig.  5) were
quite similar  to those of  1981.   Foliar
concentrations of Zn, Ni,  and Pb  showed a slight
increase from 1981 to  1989.  Although sludge
 application appeared to increase some trace metal
 concentrations  in the foliage,  these increases were
 minimal and well  below the suggested tolerance
 levels  for agronomic crops (Melsted 1973).   No
 phytotoxicity symptoms were observed during the
 study.   The suggested tolerance levels are  not
 phytotoxic levels but suggest foliar concentration
 levels  at which decreases  in growth may be
 expected.

 Spoil Chemical  Status

     Changes in  spoil pH over time  are shown in
 Table 5.   Spoil pH tended  to increase from  1977 to
 1979 and declined thereafter.   This  may explain why
 some of the foliar trace metal  concentrations
 showed  an increase in 1989.   The nutrient status of
 the  spoil  seemed  to  show a general  increase in
 concentrations  of Kjeldahl-N up to  1981 and up to
 1984 for Bray-phosphorus,  K and Ca  (Table 6).   The
 application of  lime  and sludge  initially resulted
 in a decrease in  the  concentration  of Mg; however,
 since 1978  there  has  been  a steady  increase.   The
 1989 values  are lower but  still quite adequate to
 support  plant growth.

    Concentrations of extractable trace  metals in
 the 0 to  15  cm  spoil  depth are  given  in  Table  7  and
 for the  15  to 30  cm  spoil  depth in Table 8.
 Concentrations  of  Cu,  Zn,  Cr, Pb, Cd,  and Ni all
 show a steady increase  for the  first  five years
 (1977-81).   By  this  time,  most  of the  sludge
 organic matter was probably mineralized  and most  oi
 the trace metals released  to the surface spoil.
 Results of  spoil analyses  in 1984 and  1989 showed a
 gradual decrease in concentrations of  all trace
 metals.   Although  the  sludge application seemed  to
 increase the concentrations of  extractable trace
 metals in the 0 to 15  cm spoil  depth,  these higher
 concentrations are still within the normal ranges
 for these elements in U. S. soils (Allaway 1968).

    It appears that there  is some leaching of  trace
metals through the spoil profile.  Concentrations
of trace metals  in the 15 to 30 cm spoil depth show
a general increasing trend from 1977 to 1989.

Groundwater Quality

    Results of the analyses of groundwater well
samples  are given  in Table 9.  The values for Well
                                                    275

-------
                   Table  3.   Mean foliar concentrations of macronutrient  elements  in
                             orchardgrass and birdsfoot trefoil  collected from  the
                             control and sludge-amended plots.
                   Sludge
                   application
                              Year
Orchardgrass
                                                                        Birdsfoot trefoil
                                                         Ca
                  Mg
                                                                                 K
                                                                                       Ca
Mg
                  Mg/ha
0 1977
1978
1979
1980
1981
1989
184 1977
1978
1979
1980
1981
1989

0
1
1.
1
1.
2.
1.
1.
1.
2.
2.
-L
.92
.17
.11
.22
.67
.62
26
33
70
57
36

0.18
0.22
0.24
0.18
0.17
0.40
0.37
0.51
0.42
0.37
0.37

1.51
2.41
1.86
1.62
1.82
2.84
2.01
2.53
2.65
2.38
2.24

0.36
0.30
0.32
0.68
0.42
0.84
0.49
0.47
0.45
0.53
0.45

0.23
0.22
0.20
0.22
0.30
0.31
0.28
0.23
0.23
0.26
0.22

1.03
2.59
2.11
3.32
2.31
3.64
1.27
3.57
2.93
4.03
2.38

0.24
0.14
0.17
0.17
0.17
0.27
0.36
0.25
0.25
0.26
0.16

1.93
1.74
1.92
1.89
1.71
1.46
2.30
1.56
1.62
1.69
1.01

0
1
1
1
0
1
0,
0.
1
1.
0.

.61
.82
.02
.52
.92
.99
.59
.54
.27
.14
.65

0.26
0.40
0.23
0.29
0.22
0.28
0.25
0.20
0.18
0.23
0.23
                   No plants available for sampling
                      Table 4.  Mean  foliar concentrations of macronutrient elements in
                                crownvetch on  the sludge-amended plot.
                      Year
                                                          Crownvetch
                                                           K
                                                                       Ca
                                                                                   Mg
1977
1978
1979
1980
1981
1989
3.36
2.35
3.35
3.00
3.78
2.62
0.34
0.37
0.22
0.27
0.31
0.21
1.64
3.14
1.29
1.89
1.89
2.20
2.63
0.96
1.68
1.72
1.25
0.91
0.42
0.45
0.25
0.29
0.23
0.26
                      Table 5.  Changes in Spoil pH over the thirteen year period
                      Depth
                                                           Soil pH


cm
0-15
15-30
May
19771

3.8
3.8
Sept
1977

6.2
4.2
Nov
1978

6.7
4.6
Oct
1979

7.3
5.1
May
1981

5.8
3.4
Aug
1989

5.4
5.6
                       Pre-treatment samples
1 (control) reflect quality of groundwater for the
disturbed mine site.  Well 2 reflects the effects
of the sludge application on water quality.  Depth
to the water table was 4.9 m in Well 1 and 3.0 in
Well 2 in 1989.  During the first five years (1977
to 1981) the water table fluctuated between 4.4 to
5.3 m in Well 1 and between 2.5 and 3.4 ra in Well
2.  Results indicate that the sludge application
did not appear to have any significant effect on
groundwater concentrations of nitrate-N.  Average
monthly concentrations of NC>3-N were below 10 mg/1
             (maximum concentration for potable water) for all
             months sampled during the five-year period (1977-
             81).   The highest monthly values were 3.0 mg/1 for
             the control well and 2.4 mg/1 for Well 2.

                 Application of lime and sludge and subsequent
             revegetation appears to have had a positive effect
             on groundwater pH (Table 9) .   Groundwater pH
             increased from 4.6 (1977) to 6.0 by 1981.  Results
             of the 1989 sampling indicated a pH of 6.6.   There
             has also been a gradual increase in pH in the
                                                   276

-------
                     Table 6.   Changes  in  concentrations  of  Kjeldahl-nicrogen,  Bray-
                               phosphorus  and exchangeable cations  in the  spoil collected
                               at  the 0-15  cm depth
Year

Kjeldahl
Nitrogen
Bray
Phosphorus
K
Ca
Mg
.

May
Sept





1 Pre
19771
1977
1978
1979
1981
1984
1989
-sludge
0.04
0.05
0.09
0.16
0.34
—
0.12
samples
2
11
9
38
79
91
83

12
19
23
46
45
74
30

541
1222
2600
3873
1298
1440
733

452
32
40
53
99
108
84

                   Table 7.  Changes in concentrations of extractable trace metals from
                             spoil collected at the 0-15 cm depth following sludge
                             application.
Sampling
Date

May
Sept





Normal
for U.

19771
1977
1978
1979
1981
1984
1989
Range
S. Soils
Cu


2.5
10.8
8.8
58.7
87.3
57.6
51.9
2-
100
Zn


2
7
7
56
74.
59.
37.
10-
300



.9
.7
. 7
.9
.6
6
8


Cr2


0.2
0.4
0.2
1.7
3.5
...
---
5-
3000
Pb
•gAg -•
0.
3.
2.
13.
22.
14.
13.
2-
200
Cd


5
5
3
0
7
8
5




0
0
0.
0.
0.
0.
0.
0.
7.


.02
.04
.02
.27
95
56
42
01
00
Ni


1
0
1.
1.
2.
2.
2.
5-


.1
.9
.2
.5
8
8
0

500
                    May 1977 values represen
                    Values for Cr are total concentrations.
   conditions
control well from pH 4.4  to pH 5.8.  Since 1980,
attempts have been made to reclaim the control area
by conventional methods using lime and fertilizer.
The amounts of lime and fertilizer applied and
frequency of application  are not known as the coal
company is no longer in business.  However, these
applications and vegetation growth probably
contributed to the increase in groundwater pH in
the control well.

    There appears to be no significant increase in
any of the trace metal concentrations over the
initial five-year period  (1977-1981)  in the
groundwater samples from Well 2 compared to the
control well (Table 9).  From 1977 to 1981 most of
the monthly concentrations were within the U.S.
Environmental Protection Agency drinking water
standards.   The only exception was Pb which
exceeded the limit of 0.05 mg/1 for both the
 control  well  and Well  2,  probably  resulting from
 solubilization upon  weathering  after  mining.   The
 highest  monthly Pb values were  0.28 mg/1  in the
 control  well  and 0.33  mg/1 in Well 2  in 1978,  and
 the  mean annual Pb concentrations  were  0.19 and
 0.20 rag/1 for control  well and  Well 2,
 respectively.   By 1981, however, the  mean annual Pb
 concentrations had decreased to 0.04  and  0.05  mg/1

for the two wells.   Results of  analyses of the
groundwater samples  collected in 1989  had extremely
low concentrations of all trace metals in both
wells in comparison  to values for the  initial five
years (1977-81).

                    Conclusions

    Re-evaluation of an abandoned strip mine spoil
bank 12 years after  being amended with 184 Mg/ha of
                                                    277

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                        Table 8.   Changes  in concentrations of extractable trace metals from
                                  spoil  collected  at  the  15-30 cm depth following sludge
                                  application.
Sampling
Date

May
Sept





19771
1977
1978
1979
1981
1989
Cu


3
4
2
9
2
13.



.0
.0
.5
.2
.4
,8
Zn


2.4
2.0
1.7
8.7
2.8
10.2
Cr


0
0
<0
0.
0.
0.


.10
.10
.01
,28
05
43
Pb
mg/1
0
1
1,
2.
0.
3.

iCg - -
.6
.3
.3
.4
5
8
Cd


0
0
0.
0.
0.
0.


.020
.010
,007
,026
014
122
Ni


1.0
0.4
0.7
0.2
0.4
1.9
                        May 1977 values represent pretreatment conditions
                        Values for Cr are total concentrations

                   Table 9.   Mean annual concentrations  of nitrate  -  N  and  trace metals  in
                             groundwater
                   Site
Year1    pH     N03-N   Cu
                                                           Zn
                                                                  Cr
                                                                          Pb
                                                                                  Cd
                                                                                          Ni
Well 1
1977
(control) 1978




Well 2
(sludge)




1979
1980
1981
19892
1977
1978
1979
1980
1981
19892
4.4
4.3
4.6
5.5
5.7
5.8
4.6
4.5
4.4
5.7
6.0
6.6
EPA drinking
1.4
<0.5
<0.5
0.6
0.7
0.02
1.1
<0.5
<0.5
0.6
0.6
0.06
10
0.22
0.23
0.17
0.05
0.06
0.01
0.10
0.14
0,18
0.05
0.05
0.01
1
4.13
2.02
1.48
0.89
0.83
0.09
3.39
3.29
1.49
1.05
0.57
0.07
5
0
0
0
0,
0

0.
0.
0.
0.
0.
<0.
0.
- Ul£/
.02
.01
.03
.05
.03
,001
03
01
03
04
02
001
05
0.14
0.19
0.13
0.09
0.04
0.01
0.09
0.20
0.13
0.11
0.05
0.01
0.05
0
0
0
0
0
0
0
o.
0
0,
0,
0
0.
.006
.002
.001
.001
.003
.001
.001
.002
.001
.001
.001
.001
010
3.67
0.98
0.50
0.50
0.31
0.06
2.67
1.26
0.97
0.76
0.31
0.04
- . .
water standard
Values
Average
are annual means of monthly
of three
samples collected
samples.
in August






1989.
 municipal sludge indicates that a single large
 application of sludge can be used successfully to
 revegetate mine lands with no apparent adverse
 effects on vegetation, spoil, or groundwater
 quality.

                  Literature  Cited
Allaway, W. H.  1968.  Agronomic controls over the
    environmental cycling of trace metals.  Adv.  In
    Agron. 20:235-271.

Baker, D. E.,  G. W. Gorsline, C. B. Smith, W. I.
    Thomas, W. E. Grube, and R. L. Ragland.  1964.
    Technique  of rapid analyses of corn leaves for
                                  eleven  elements.  Agron. J. 56:133-136.

                               Ellis, B. G.   1976.  Analyses and their
                                  interpretation for wastewater application on
                                  agricultural  land.  North Central Regional
                                  Research Publication 235-Sec. 6.

                               Federal Register.  1989.  Standards for the
                                  Disposal of Sewage Sludge.  Proposed Rule  Vol.
                                  54(23), Feb.  6, 1989, Part II, 40CFR parts 257
                                  and 503, p. 5746-5902.

                               Jackson, M. L.  1958.  Soil Chemical Analysis.
                                  Prentice-Hall, Inc., Englewood Cliffs, NJ.
                                                    278

-------
 Joost,  R.  E.,  J.  H.  Jones,  and F.  J.  Olsen.   1981.
     Physical  and  chemical  properties  of coal  refuse
     as  affected by  deep  incorporation of sewage
     sludge  and/or limestone,  p.  307-312.   In:
     Proc.  Symp. on  Surface  Mining  Hydrol.,
     Sedimentol.,  and Reclamation.   (Univ.  of
     Kentucky,  Lexington, KY,  7-11  Dec.  1981).

Melsted, S. W.  1973.  Soil-plant  relationships.
     p.  121-128.   Jn:  Recycling Municipal  Sludges
     and Effluents on Land,  Nat. Assoc.  of  State
    Universities  and Land Grant Colleges,
    Washington, DC.

Pennsylvania Department of  Environmental Resources.
    1977.   Interim guidelines for  sewage sludge use
    for land reclamation.   In:  The Rules and
    Regulations of the Department of Environmental
    Resources, Commonwealth of Pennsylvania, Chapt.
    75,  Subchapt.  C, Sec. 75.32.

Seaker,  E.  M.  and W. E Sopper.  1984.   Relcamation
    of bituminous  strip mine spoil banks with
    municipal  sewage sludge.  Reclam.  Reveg. Res.,
    3:87-100.
Sopper, W. E., E. M. Seaker, and R. K. Bastian
    (Editors).  1982.  Land Reclamation and Biomass
    Production with Municipal Wastewater and
    Sludge.  The Pennsylvania State Unviersity
    Press, University Park, PA  16802.

Sopper, H. E. and E. M. Seaker.  1983.  A guids for
    revegetation of mined land in eastern United
    States using municipal sludge.  Institute for
    Research on Land and Water Resources, The
    Pennsylvania State University, Universit Park,
    PA.,  93 pp.

United States Department of Agriculture  1980.
    Soil and Water Resource Conservation Act:
    Appraisal 80.  USDA, Washington, D. C.

United States Environmental Protection Agency
    1974.  Methods for Chemical Analysis of Water
    and Wastes.  Washington, D. C.

United States Environmental Protection Agency.
    1977.  Municipal Sludge Management:
    Environmental Factors.  Tech. Bull. EPA 430/9-
    76-004, MCD-28.
                         300



                          <
                         120

                         110

                         100

                          90

                          80

                         70

                         60

                         50

                         40

                         30

                         20

                         10
                             SUGGESTED TOLERANCE LEVEL
•——GOG- 184 Mg/ha
•     OG-   0 Mg/ha
Q—O cv" 184 Mg/ha
O
                              1977      1978     1979      1980
                                                                 1981
                                                                              1989
                        Figure 1.  Mean foliar concentration of Zn in orchardgrass
                                   and crownvetch collected from the control and
                                   sludge-amended plots.
                                                    279

-------
       SUGGESTED TOLERANCE LEVEL
                                  9  9 OG"  184 M§/ha
                                  •    OG-   0 Mg ha
                                  O—O CV-  184 Mgrtia
        1977
                 1978
                         1979
                                 1980
                                         1981
                                                      1989
     Figure 2.   Mean foliar concentration of  Ca  in
                 orchardgrass  and  crownvetch collected
                 from the control  and sludge-amended
                 plots.
  10
     SUGGESTED TOLERANCE LEVEL
   8

   7

I 6
Q)

£  5
e
S  4
O
u.
   3 -

   2 -
                                       •OG-  184 Mfl/ha
                                         OG-   0 Mg'tia
                                       O CV-  184 Mg/ha
      1977
               1978
                       1979
                               1i80
                                       1981
  Figure 3.   Mean foliar  concentration of  Pb  in
              orchardgrass  and crownvetch collected
              from the control and sludge-amended
              plots.
                          280

-------
        SUGGESTED TOLERANCE LEVEL
                                  •	0OG- 194 Mg/ha
                                  •     OG-   0 Mg/ha
                                  O--O cv" 184 Mg/ha
         1977
                 1978
                         1979
     Figure 4.  Mean  foliar  concentration of Ni in
                orchardgrass and  crownvetch collected
                from  the  control  and sludge-amended
                plots.
     SUGGESTED TOLERANCE LEVEL
                                     •    > OG-  184 Mg/ha
                                     •      OG-    0 Mg/ha
                                     O	Q CV-  184 Mg/ha
      1977
               1978
                        1979
Figure 5.  Mean  foliar concentration of Cd in orchardgrass
           and crownvetch collected from the control  and
           sludge-amended plots.
                         281

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Citation for this Publication:

Sopper, W.E. and Eileen M. Seaker.  1990.  Long-Term Effects of
     a Single Application of Municipal Sludge on Abandoned Mine
     Land.  Proc. of The 1990 Mining and Reclamation Conference
     and Exhibit, J. Skousen et al. (eds.), Vol. II:  579-587,
     West Virginia University, Morgantown, WV.
                              282

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                                                 Appendix B
                                  Federal Sewage Sludge Contacts
Table B-1.  EPA Regional Sewage Sludge Contacts
REGION 1
Thelma Hamilton (WMT-ZIN)
JFK Federal Bldg.
One Congress St.
Boston, MA 02203
(617) 565-3569
Fax (617) 565-4940

REGION 2
Alia Roufaeal
Water Management Division
26 Federal Plaza
New York, NY 10278
(212) 264-8663
Fax (212) 264-9597

REGION 3
Ann Carkhuff (3WM55)
841 Chesnut St.
Philadelphia, PA 19107
(215) 597-9406
Fax (215) 597-3359

REGION 4
Vince Miller
Water Division
345 Courtland St.,  NE.
Atlanta, GA 30365
(404)347-3012 (ext. 2953)
Fax (404) 347-1739

REGION 5
Ash Sajjad (5WQP-16J)
Water Division
77 W Jackson Blvd.
Chicago, IL 60604-3590
(312)886-6112
Fax (312) 886-7804
REGION 6
Stephanie Kordzi (6-WPM)
Water Management Division
1445 Ross Ave., #1200
Dallas, TX 75202-2733
(214)665-7520
Fax (214) 655-6490

REGION 7
John Dunn
Water Management Division
726 Minnesota Ave.
Kansas City, KS 66101
(913) 551-7594
Fax (913) 551-7765

REGION 8
Bob Brobst (8WM-C)
Water Management Division
999 18th St., Suite 500
Denver, CO 80202-2405
(303) 293-1627
Fax (303) 294-1386

REGION 9
Lauren Fondahl
Permits Section
75 Hawthorne St. (W-5-2)
San Francisco, CA 94105
(415) 744-1909
Fax (415) 744-1235

REGION 10
Dick Hetherington (WD-184)
Water Management Division
1200 Sixth Ave.
Seattle, WA98101
(206) 553-1941
Fax (206) 553-1775
                                                       283

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                                        U.S. EPA Regions
       Region—State
        4—Alabama
       10—Alaska
        9—Arizona
        6—Arkansas
        9—California
        8—Colorado
        1—Connecticut
        3—Delaware
        3—Washington, DC
        4—Florida
        4—Georgia
        9—Hawaii
       10—Idaho
        5—Illinois
        5—Indiana
        7—Iowa
        7—Kansas
        4—Kentucky
        6—Louisiana
Region—State
 1—Maine
 3—Maryland
 1—Massachusetts
 5—Michigan
 5—Minnesota
 4—Mississippi
 7—Missouri
 8—Montana
 7—Nebraska
 9—Nevada
 1—New Hampshire
 2—New Jersey
 6—New Mexico
 2—New York
 4—North Carolina
 8—North Dakota
 5—Ohio
 6—Oklahoma
10—Oregon
Region—State
 3—Pennsylvania
 1—Rhode Island
 4—South Carolina
 8—South Dakota
 4—Tennessee
 6—Texas
 8—Utah
 1—Vermont
 3—Virginia
10—Washington
 3—West Virginia
 5—Wisconsin
 8—Wyoming
 9—:American Samoa
 9—Guam
 2—Puerto Rico
 2—Virgin Islands
Figure B-1. Map of U.S. EPA regions.
                                                  284

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                                           Appendix C
                              Permit Application Requirements
Permits that are issued to publicly owned treatment
works (POTWs) must include standards for sewage
sludge use or disposal. In addition, EPA may issue
sewage sludge  permits to  other  "treatment works
treating domestic sewage" (TWTDS) (i.e., treatment
works that generate, change the quality of, or dispose
of sewage sludge).

The EPA's sewage sludge permit program regulations
establish a framework for permitting sewage sludge use
or disposal. The regulations  require submission  of a
permit application that provides the permitting authority
with sufficient information to issue an appropriate permit.
A permit application must include information on the
treatment work's identity, location, and regulatory status,
as well as information on the  quality, quantity, and ulti-
mate use or disposal of the sewage sludge managed at
the treatment works.

Because the sewage sludge permitting regulations were
promulgated several years before the Part 503 stand-
ards, they describe the required application information
in broad, almost generic terms. Currently, EPA is devel-
oping application forms and the Agency is planning  to
revise the permit application regulations to reflect  spe-
cifically the Part 503 standards  and to enable permit
writers to tailor permit requirements to facilities' specific
use or disposal practices.

The deadlines  for submitting  permit applications were
revised in 1993 and are as follows:

• Applicants requiring site-specific pollutant limits  in
  their permits (e.g., sewage sludge incinerators) and
  facilities requesting  site-specific  limits  (e.g., some
  surface disposal sites) were required to submit appli-
  cations by August 18, 1993.

• All other applicants with National Pollutant Discharge
  Elimination System (NPDES) permits are required  to
  submit sewage sludge permit applications at the  time
  of their next  NPDES permit renewals.
• So-called sewage sludge-only  (non-NPDES)  treat-
  ment works that are not applying for site-specific lim-
  its, and are not otherwise  required to submit a full
  permit  application,  only  need  to submit  limited
  screening  information  and  must have  done so by
  February 19, 1994.
The permit application information that must be submit-
ted depends upon the type of treatment works and which
sewage sludge  management practices the treatment
works employs. Questions on permit applications should
be directed to the appropriate State and EPA Regional
Sewage Sludge Coordinators  listed in Appendix B.

Sludge-Only Treatment Works
The limited screening information submitted by a sew-
age sludge-only treatment works typically will include
the following:
• Name  of treatment works, contact person, mailing
  address, phone  number, and location.
• Name and address of owner and/or operator.
• An indication of whether  the treatment works  is
  a POTW, privately  owned treatment  works,  fed-
  erally owned treatment  works, blending or treat-
  ment operation, surface disposal site, or sewage
  sludge incinerator.
• The amount of sewage sludge generated (and/or re-
  ceived  from another treatment works),  treated, and
  used or disposed.
• Available data on pollutant concentrations in the sew-
  age sludge.
• Treatment to reduce pathogens and vector attraction
  properties of the sewage sludge.
• Identification of other facilities receiving the sewage
  sludge  for further processing or for use  or disposal.
• Information on sites where the sewage sludge is used
  or disposed.
                                                285

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Facilities Submitting Full Permit Applications

A full  permit application is much more comprehensive
than the limited screening information described above
for sewage sludge-only facilities. A full permit application
typically will include the following information:

General Information

• Name of treatment  works, contact person,  mailing
  address, phone number, and  location.

• Name and address of owner  and/or operator.

• An indication of whether the treatment works is a POTW,
  privately owned treatment works, federally owned treat-
  ment works,  blending or treatment operation,  surface
  disposal site, or sewage sludge incinerator.

• Whether the treatment works is a Class I sludge man-
  agement facility (i.e.,  a pretreatment POTW or another
  facility designated Class I by the permitting authority).

• The NPDES permit number (if any) and the number
  and type of any relevant Federal, State, or local en-
  vironmental permits or construction approvals applied
  for or received.

• Whether any sewage sludge management occurs on
  Native American lands.

• A topographic map showing sewage sludge manage-
  ment facilities and water bodies 1 mile beyond the
  property boundary and drinking water wells 1/4 mile
  beyond  the property boundary.

• Results  of hazardous waste testing for the sewage
  sludge,  if any.

• Data on  pollutant concentrations in the sewage sludge.
Information on Generation of Sewage Sludge or
Preparation of a Material From Sewage Sludge

• The amount  of sewage sludge generated.

• If sewage sludge is received from off site, the amount
  received, the name and address of the offsite facility,
  and any treatment the sewage sludge has received.
• Description of any treatment at the applicant's facility
  to reduce pathogens and vector attraction properties
  of the sewage sludge.

• Description of any bagging and distribution activities
  for the sewage sludge.

• If sewage sludge is provided to  another facility for
  further treatment, the amount provided, the name and
  address of the receiving facility, and any treatment
  occurring at the receiving facility.

Information on Land Application of Sewage
Sludge

• The amount of bulk sewage sludge applied to the land.

• The nitrogen content of bulk sewage sludge  applied
  to the land.

• The name and location of land application sites, and
  a copy of the land application plan if all sites  have
  not been identified.

• The name and address of the owner and the person
  who applies bulk sewage sludge to  each site.

• The site type and the type of crop or other vegeta-
  tion grown.

• Description of any processes at each land application
  site to reduce vector attraction properties of the  sewage
  sludge.

• Ground-water monitoring data, if available.

• If bulk sewage sludge is subject to cumulative pollut-
  ant loading rates, information on how the necessary
  tracking and notification requirements will be met.

• If bulk sewage  sludge  is applied to the land in a
  different state, information  on how the  permitting
  authority in the receiving state will be notified.

All permit applications must be signed and certified. The
permitting authority may request additional information
to assess sewage  sludge  use or disposal practices,
determine whether  to issue a permit, or identify appro-
priate permit requirements.
                                                 286

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                                      Appendix D
                                  Conversion Factors
Table D-1. Conversion Factors (Metric to U.S. Customary)
Metric
Name
Centimeter(s)
Cubic Meter

Cubic Meters Per Day
Cubic Meters Per Hectare
Degrees Celsius
Gram(s)
Hectare
Kilogram(s)
Kilograms Per Hectare
Kilograms Per Hectare Per Day
Kilograms Per Square Centimeter
Kilometer
Kilowatt
Liter

Liters Per Second
Metric Tonne
Metric Tonnes Per Hectare
Meter(s)
Meters Per Second
Micrograms Per Liter
Milligrams Per Liter
Square Centimeter
Square Kilometer

Abbreviation
cm
m3

m3/d
m3/ha
°C
g
ha
kg
kg/ha
kg/ha/d
kg/cm2
km
kW
L

L/s
t
t/ha
m
m/s
|ig/L
mg/L
cm2
km2
Multiplier
0.3937
8.1071 x 10'4
35.3147
264.25
2.641 7 x 10'4
1 .069 x 1 0'4
1 .8 (°C) + 32
0.0022
0.24711
0.004
2.205
0.0004
0.893
14.49
0.6214
1.34
0.0353
0.264
0.035
22.826
15.85
0.023
1.10
0.446
3.2808
2.237
1.0
1.0
0.155
0.386
U.S.
Abbreviation
in
acre-ft
ft3
Mgal
Mgal/d or MGD
Mgal/acre
°F
Ib
acre
mi2
Ib
T/ac
Ib/ac/d
Ib/in2
mi
hp
ft3
gal
ft3/s
gal/d
gal/min
Mgal/d
T
T/ac
ft
mi/h
ppb
ppm
in2
mi2
Customary Unit
Name
inches
a ere -foot
cubic foot
million gallons
million gallons per day
million gallons per acre
degrees Fahrenheit
pound(s)
acre
square miles
pound(s)
tons per acre
pounds per acre per day
pounds per square inch
mile
horsepower
cubic foot
gallons
cubic feet per second
gallons per day
gallons per minute
million gallons per day
ton (short)
tons per acre
foot (feet)
miles per hour
parts per billion
parts per million
square inch
square mile
                                           287

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Table D-2. Dry Weight Basis
                          BIOSOLIDS  FACT   SHEET
   EPA REGION* Vm—M>DES Branch-Permts Program
   999 ISA Street. Suite 500, Denver. Colorado 80202
   Mr, Robert Brobsi
                              EPA REGION X—NPDES Branch-Permits Program
                              1200 6ih Avenue, Seattie, Washington 9S101
                              Mr. Richard Hecaherington
   3.3
   DRY WEIGHT
   BASIS (FS/793/03/1)
Laboratory results for sludge are typically reported in one of two forms,
wet weight (i.e., mg/L) or a dry weight (i.e., mg/kg).  You should
request your laboratory to provide the results on a dry weight basis.  In
the event that the laboratory results are reported  on a wet weight basis
(i.e.,  in mg/L), the results for each pollutant in each sample must be
recalculated to determine the dry weight concentration.  To accomplish
this conversion, the percent total solids in the sludge sample must be
known.

The following equation can be used to determine the dry weight
concentration because the equation uses the assumption that the specific
gravity of water and sewage sludge are both equal to one.  However, this
assumption holds true only when the solids concentration in the sludge is
low.  The calculated dry weight concentration may vary slightly from the
actual  concentration as the solids content increases because the density of
the sewage sludge may  no longer be equal to that of water.  Typically,
this concern is unrealized as the solids content of sludge is usually low.
EPA is aware of this  potential problem and may  make a determination
regarding this matter  at a later date.
                            Determine the pollutant concentration on a dry weight basis using the
                            following abbreviated conversion:1

                                   PC(dry»mg/kg) =  /POwet.  mg/L)\
                                                          \ % total solids  /
                            where  PC = Pollutant Concentration

                            A unit conversion is incorporated into the equation.
     lAnalytical Methods Used in the National Sewage Sludge Survey.  August !988.  U.S. EPA Office of Water Regulations and
  Standards (WH-552), Industrial Technology Division, Washington, DC.
                                                  288

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Table D-2. (continued)
                                        FS/793/03/1

                                     Dry Weight Basis
  Determine the pollutant concentration on a dry Weight basis using the following conversion:

         PC(dry,mg/kg) =  /PCfwet. mg/L)|
                             I % total solids  I
  Example #1: Determine the dry weight concentrations of the pollutants.

      The laboratory analysis of your sludge yielded the following results:

  As - 6.6 mg/L  Cd - 5.5 mg/L   Cr - 192.5 mg/L Cu - 374 mg/L
  Pb - 44  mg/L  Hg - 0.22 mg/L  Mo - 0.88 mg/L  Ni - 44 mg/L
  Se-2.2 mg/L  Zn - 330 mg/L

      The percent solids was determined to be 22%.

  Therefore, using the given equation, the dry weight concentration of As can be determined as follows:

  6.6 mg/L (As.wet)  =  6.6 mg/L   =    30 mg/kg    As, dry weight
           22 %             0.22

  Remember to convert the percent total solids to a decimal by multiplying by 100.

  The remainder of the converted results are:

  Cd=25mg/kg, Cr=875mg/kg, Cu=l,700mg/kg, Pb=200mg/kg, Hg=lmg/kg, Mo=4mg/kg,
  Ni=200mg/kg, Se=10mg/kg,   Zn=l,500mg/kg
   (    )mg/L   =  (    )mg/L  =  (      )mg/kg dry weight
   (      ) %         0.
                                            289

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Table D-3.  Conversion of Sludge Volume to Dry Metric Tons.
                                _    ,                     ~,,   -                   ,
                             SOR COIWIRIING $UJD6fe^OL|fll TO:DR^ METRIC TOMST
    Applicability;

    The amount of sewage sludge used or disposed must be reported as metric tons, dry weight.

    Procedure:

    Step 1: Convert the common measure (e.g., cubic yards or gallons) to the English System or short tons, dry
           weight.
                   Dry short tons = gallons of sewage sludge x —	x 	x Percent Solids
                                                               gallon    2000 Ib

             8.34 Ib/gal is the density of water.   This equation is therefore applicable to liquid sludges (less
             than 5 percent solids). Site-specific densities may be determined and substituted in this equation
             for a more accurate result.
             Dry short tons = cubic yards (wet) of sewage sludge x	 x 	x Percent Solids
                                                                 cubic yard    2000 Ib

             Y Ib/cubic yard is the site-specific bulk density of the sewage sludge. It must be determined for
             each type of sludge prepared and substituted in the equation for accurate results.	
   Step 2: If you are starting with the English System or short tons, convert them to dry weight.

                                      Dry tons = Wet tons x Percent Solids



   Step 3: Convert the English System or short tons to metric tons.

                                    Dry  metric tons  = Dry short tons x .907
   Source: U.S. EPA. 1993. Preparing sewage sludge for land application or surface disposal. EPA/831/B-93/002a.
   Washington, DC.
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