EPA-625/1-78-010
SW-705
                        PROCESS DESIGN MANUAL

                      MUNICIPAL SLUDGE LANDFILLS
                 U.S.  ENVIRONMENTAL PROTECTION  AGENCY

               Environmental  Research Information  Center
                          Technology Transfer

                         Office of Solid Waste
                             October 1978

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           NOTICE
The  mention  of  trade  names  of
commercial products in this pub-
lication   is   for  illustration
purposes and does not constitute
endorsement  or   recommendation
for  use  by  the  U.S.   Environ-
mental Protection Agency.

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                UNITED STATES  ENVIRONMENTAL PROTECTION  AGENCY
   Municipal sludge management is perhaps one of the most visible and
   complex problems facing wastewater treatment authorities today.   The
   combination of greatly increased sludge volumes and the narrowing of
   formerly used disposal options (such as ocean dumping)  compounds this
   problem.   Congress,  in enacting the Resource Conservation and Recovery
   Act,  and the Clean Water Act,  acknowledged its concern over the
   disposal of residuals resulting from the cleanup of our environment.
   A common goal of these two acts is the conservation of natural
   resources and energy through reuse waste materials.

   EPA is committed to a residuals management program that will not only
   protect public health and the  environment but will maximize the use
   of waste materials in beneficial ways.   Specifically,  management
   technologies which recycle or  reuse municipal sludges and thereby
   contribute to energy and resource conservation are actively encouraged.

   Unfortunately, beneficial utilization of sludge is not always
   practicable or economical.  Therefore, sanitary landfilling of
   municipal sludge will continue as a .major disposal option.   It is
   the purpose of this manual to  provide the engineering community,
   related industry, and local government with a new source of information
   for the planning, design and operation of municipal sludge landfills.
   It has been written to provide design and operational guidance to
   sanitary landfill operators and information to assist in the
   preparation of sewage treatment plant construction grant applications.

   The usefulness of this manual  will be further enhanced with the
   promulgation of sludge utilization and disposal guidelines that are
   now being developed under the  authority of Section 405 of the Clean
   Water Act.  The manual will provide publicly owned treatment works
   with the detailed technical information needed to comply with the
   landfilling portions of those  guidelines.
S
    teffen Plehn
/  Deputy Assistant Administrator
   for Solid Waste
'John T. Rhett
Deputy Assistant Administrator
for Water Program Operations
   Samuel Rondberg
   Acting pirector
   Office of Research
   Program Management

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                             ACKNOWLEDGEMENTS


There  were three groups  of participants  involved  in the  preparation  of
this  manual:   (1) the  contractor-authors,  (2) the contract  supervisors,
and  (3)  the  review  committee.   The  manual  was written by  personnel  from
SCS  Engineers.   Contract supervision  was  provided by U.S.  Environmental
Protection  Agency  (EPA)  personnel  from  the  Office  of  Solid  Waste  in
Washington,  D.C., and  from  the Environmental   Research Information  Center
in  Cincinnati,  Ohio.   The  review committee  was  comprised of  potential
manual   users  including   regulatory  officials,  public  and   private
operators,  and  consultants.   The Technical   Practice Committee  of  the
Water  Pollution  Control   Federation  also  reviewed   the  manual.     The
membership of each group  is  listed below.

CONTRACTOR-AUTHORS:  SCS  Engineers

Direction:   E. T. Conrad  and R. Stearns,  Principals

Senior Author:  J. Walsh, Project  Manager

Staff Authors:  J. Atcheson, E. Bowring, W. Coppel, R. Lofy,
                R. Morrison, D. Pearson,  T. Phung,  and D.  Ross

Production Staff:  L.  Fauvie and C.  Heglar

CONTRACT SUPERVISORS:   U.S.  Environmental  Protection  Agency

Project  Officer:  J. Perry,  EPA Office of  Solid  Waste

Reviewers: J. E. Smith, Jr.  and D.  J.  Lussier, EPA  Environmental
           Research  Information Center

REVIEW COMMITTEE

M. Adams and M. Derdeyn,  Browning-Ferris  Industries
R. Bardwell, Gellman Research  Associates
R. Bastian,  EPA Office  of Water Program Operations
D. Blackman, State of  New York
W. Bucciarelli, State  of  Pennsylvania
A. Day,  State of Maine
R. Domenowske, Municipality  of Metropolitan Seattle
P. Dunlap, SCA Services
B. Fowler, Waste Management, Inc.
A. Geswein, EPA Office  of Solid Waste
E. Higgins, EPA Office  of Solid Waste
G. Lukasik, North Shore Sanitary District
R. Van Heuit, Los Angeles County Sanitation District
R. Williams, State of  Georgia

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                               CONTENTS


Chapter                                                        Page


                ACKNOWLEDGEMENTS                               in

                CONTENTS                                         v

                LIST OF TABLES                                viii

                LIST OF FIGURES                                  x

                FOREWORD                                      xiii

  1             INTRODUCTION

                1.1  Sludge Disposal Alternatives               1-1
                1.2  Sludge Landfills and Solid Waste
                     Disposal  Facility Classification
                     Criteria                                    1-2
                1.3  Objectives of Manual                       1-3
                1.4  Scope of  Manual                            1-3
                1.5  Use of Manual                              1-4
                1.6  References                                 1-6

  2             PUBLIC PARTICIPATION PROGRAM

                2.1  Introduction                               2-1
                2.2  Objectives of a Public Participation
                     Program                                    2-1
                2.3  Advantages and Disadvantages of a PPP      2-2
                2.4  PPP Participants                           2-3
                2.5  Design of a PPP                            2-4
                2.6  Timing of Public Participation             2-9
                2.7  Potential Areas of Public Concern          2-10
                2.8  Conclusion                                 2-12
                2.9  References                                 2-1?

  3             SLUDGE CHARACTERISTICS AND LANDFILLING METHODS

                3.1  Purpose and Scope                          3-1
                3.2  Sludge Sources                             3-1
                3.3  Sludge Treatment                           3-3
                3.4  Sludge Characteristics                     3-10
                3.5  Suitability of Sludge for Landfill ing      3-14
                3.6  Sludge Landfill ing Methods                 3-15
                3.7  References                                 3-32

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                         CONTENTS (Continued)


Chapter                                                        Page

  4             SITE SELECTION

                4,1  Purpose and Scope                          4-1
                4.2  Site Considerations                        4-1
                4.3  Site Selection Methodology                 4-14
                4.4  Example of Methodology                     4-19
                4.5  References                                 4-28

  5             DESIGN

                5,1  Purpose and Scope                          5-1
                5,j2  Regulations and Permits                    5-1
                5.3  Design Methodology and Data Compilation    5-5
                5.4  Selection of Landfilling Method            5-10
                5.5  Sludge-Only Trench Designs                 5-12
                5.6  Sludge-Only Area Fill Design               5-20
                5.7  Codisposal Designs                         5-24
                5.8  Environmental Safeguards                   5-26
                5r9  Storm Water Management                     5-42
                5.10 Access Roads    "                           5-44
                5.11 Other Design Features                      5-45
                5.12 References                                 5-48

  6             OPERATION

                6.1  Purpose and Scope                          6-1
                6.2  Method-Specific Operational Procedures     6-1
                6.3  General Operational Procedures             6-18
                6.4  Equipment and Personnel                    6-27
                6.5  Reference                                  6-32

  7             MONITORING

                7T1  Introduction                               7-1
                7.2  Groundwater Monitoring                     7-1
                7.3  Surface Water Monitoring                   7-13
                7.4  Gas Monitoring                             7-16
                7.5  References                                 7-17

  8             COMPLETED SITE

                8.1  Introduction                               8-1
                8.2  Procedures for Site Closure                8-2
                8,3  Characteristics of Completed Site          8-3
                8.4  Completed Site Use                         8-6
                8.5  References                                 8-8
                                   VI

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                         CONTENTS  (Continued)


Chapter                                                        Page

  9             MANAGEMENT AND COSTS

                9.1   Introduction                                9-1
                9.2   Management Responsibility                   9-1
                9.3   Equipment Management and Documentation      9-3
                9.4   Personnel Management and Recordkeeping      9-5
                9.5   General  Management  and  Recordkeeping        9-8
                9.6   Cost Recordkeeping                          9-13
                9.7   Financing                                  9-16
                9.8   Typical  Costs                               9-19
                9.9   References                                 9-29

 10             DESIGN EXAMPLES

                10.1  Introduction                                10-1
                10.2  Design Example No.  1                        10-1
                10.3  Design Example No.  2                       10-15
                10.4  Design Example No.  3                       10-27

 11             CASE  STUDIES

                11.1  Introduction                                11-1
                11.2  Case Study Summaries                       11-1
                11.3  Montgomery County,  Maryland                 11-6
                11.4Waukegan, Illinois                          11-18
                11.5  Colorado Springs, Colorado                  11-36
                11.6  Denver,  Colorado                            11-45
                11.7  Lorton,  Virginia                            11-53
                                 vn

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                                TABLES
No.                                                                Page

2-1        Suggested Timing of Public Participation
           Activities for Sample 15-Month Project                   2-10
2-2        Capabilities of Public Participation Techniques          2-11
2-3        Public Concerns                                          2-11
3-1        Conversion Processes                                     3-8
3-2        Composition of Various Ashes                             3-9
3-3        Typical Composition of Raw and Anaerobically
           Digested Primary Sludges                                 3-11
3-4        Typical Quantities of Sludge Produced by Different
           Treatment Processes                                      3-13
3-5        Chemical Composition of Municipal Wastewater Sludges     3-14
3-6        Suitability of Sludges for Landfilling                   3-16
3-7        Sludge and Site Conditions                               3-32
3-8        Design Criteria                                          3-33
4-1        Permeability Classes for Saturated Soil                  4-6
4-2        Typical Ranges of Cation Exchange Capacity of
           Various Types of Soils                                   4-7
4-3        Subsurface Logging Information Obtained by Various
           Methods                                                  4-11
4-4        Preliminary Investigations for Intitial Assessment       4-22
4-5        Investigation of Candidate Sites for Screening           4-24
4-6        Rating of Sites for Screening Using Scoring System       4-25
4-7        Operating Cost Estimates                                 4-26
4-8        Capital Cost Estimates                                   4-27
4-9        Final Site Selection                                     4-28
5-1        Analysis of Federal Criteria vs. State Regulations       5-4
5-2        Sludge Landfill Design Checklist                         5-6
5-3        Sources of Existing Information                          5-8
5-4        Field Investigations for New Information                 5-9
5-5        Design Considerations for Sludge-Only Trenches           5-13
5-6        Alternate Design Scenarios                               5-16
5-7        Design Considerations for Sludge-Only Area Fills         5-20
5-8        Design Considerations for Codisposal Operations          5-25
5-9        Range of Constituent Concentrations in Leachate
           from Sludge Landfills                                    5-27
5-10       Attenuation and Permeability Properties of Clays         5-30
5-11       Attenuation Properties of Representative Soil Series     5-31
5-12       Liners for Sludge Landfills                              5-34
5-13       Estimated Costs for Landfill Liners                      5-35
5-14       Expected Efficiencies of Organic Removal from Leachate   5-38
5-15       Gas Concentrations at Selected Sludge Landfills          5-40
6-1        Environmental Control Practices                          6-22
6-2        Inclement Weather Problems and Solutions                 6-26
6-3        Equipment Performance Characteristics                    6-28
6-4        Typical Equipment Selection Schemes                      6-29
                                  vm

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                            TABLES (Continued)
 No.                                                                Page

 7-1        Well Construction Details,  Water Levels  and Water
            Quality (Physical)                                       7-7
 7-2        Relative Abundance of Dissolved  Solids  in  Potable
            Water                                                    7-12
 7-3        Sample Size and Sample Preservation                      7-14
 8-1        Procedures for Site Closure                              8-2
 9-1        Cost Scenarios for Alternative Landfilling Methods        9-26
10-1        Estimate of Total Site Capital Costs  for Example No.  1   10-14
10-2        Estimate of Annual Operating Costs  for Example No.  1     10-14
10-3        Design Considerations for Example No.  2                  10-20
10-4        Estimate of Total Site Capital Costs  for Example
            No.  2 - Wide Trench                                     10-25
10-5        Estimate of Annual Site Operating Costs  for Example
            No.  2 - Wide Trench                                     10-25
10-6        Estimate of Total Site Capital Cost for  Example
            No.  2 - Area Fill Mound                                 10-26
10-7        Estimate of Annual Site Operating Costs  for Example
            No.  2 - Area Fill Mound                                 10-26
10-8        Estimate of Total Annual  Costs for  Example No. 3        10-32
11-1        Site Identification and Sludge Description              11-3
11-2        Site Design and Operation                               11-4
11-3        Hauling and Site Costs                                  11-5
11-4        Regulatory Requirements Relative to Site Selection
            at Montgomery County, Maryland                          11-8
11-5        Sampling and Analytical Program  at  Montgomery  County,
            MD                                                      11-17
11-6        Details on Sludge Transported from  Originating Plant
            to Sludge Processing Unit at Waukegan,  IL                11-18
11-7        Summary of Groundwater and  Gas Wells  and Surface
            Water Stations at Waukegan, IL                          11-33
11-8        Sampling and Analytical Program  at  Waukegan, IL          11-34
11-9        Summary of Sludge Generation and Transport to  Lorton,
            VA                                                      11-53
11-10       Sampling and Analytical Program  at  Lorton, VA            11-63

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                             FIGURES
No.                                                               Page

1-1       Suggested Timing of Planning, Design, and Operation
          Activities for Sample Landfill with Five Year Life       1-5
4-1       Sample Calculation:  Area Required                       4-3
4-2       Sample Calculation:  Site Life Available                 4-3
4-3       Soil Textural Classes and General Terminology Used
          in Soil Descriptions                                     4-5
4-4       Soil Permeabilities and Sorbtive Properties of Selected
          Soils                                                    4-6
4-5       Unified Soil Classification System and Characteristics
          Pertinent to Sludge Landfills                            4-8
4-6       Hydrogeological Cycle                                    4-9
4-7       Site Selection Methodology                               4-15
4-8       Initial Assessment with Overlays                         4-20
5-1       Typical Site Preparation Plan                            5-11
5-2       Trench Sidewall Variations                               5-15
5-3       Cross-Section of Typical Marrow Trench Operation         5-17
5-4       Narrow Trench Operation                                  5-17
5-5       Wide Trench Operation                                    5-18
5-6       Cross-Section of Typical Wide Trench Operation           5-19
5-7       Cross-Section of Wide Trench with Dikes                  5-19
5-8       Cross-Section of Typical Area Fill Mound Operation       5-22
5-9       Area Fill Mound Operation                                5-22
5-10      Cross-Section of Typical Area Fill Layer Operation       5-23
5-11      Cross-Section of Typical Diked Containment Operation     5-24
5-12      Water Balance at Sludge Landfill                         5-28
5-13      Underdrain for Leachate Collection                       5-37
5-14      Upgrading Groundwater Interceptor Trench                 5-37
5-15      Permeable Method of Gas Migration Control                5-41
5-16      Earthen Drainage Channel                                 5-43
5-17      CMP Drainage Channel                                     5-43
5-18      Stone Drainage Channels                                  5-44
5-19      Special Working Area                                     5-46
6-1       Narrow Trench Operation                                  6-5
6-2       Wide Trench Operation at Refuse Landfill                 6-6
6-3       Wide Trench Operation with Dragline                      6-7
6-4       Wide Trench Operation with Interior Dikes                6-8
6-5       Area Fill Mound Operation                                6-13
6-6       Area Fill Layer Operation                                6-14
6-7       Area Fill Layer Operation Inside                         6-15
6-8       Diked Containment Operation                              6-16
6-9       Sludge/Refuse Mixture Operation                          6-19
6-10      Sludge/Refuse Mixture with Dikes                         6-20
6-11      Sludge/Soil Mixture                                      6-21
6-12      Scraper                                                  6-30

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                         FIGURES  (Continued)
 No.                                                                Page

 6-13      Backhoe with Loader                                      6-30
 6-14      Load Lugger                                              6-31
 6-15      Trenching Machine                                        6-31
 7-1        Landfill Water Balance Simplified                         7-2
 7-2        Water Table and Land  Surface  Contour  Map  with  Test
           Well Locations                                           7-6
 7-3        Typical Monitoring Well  Screened Over a Single
           Vertical Interval                                        7-8
 7-4        Typical Well Cluster  Configurations                       7-9
 8-1        Infiltration Rates for Various  Crops                      8-7
 9-1        Equipment Inspection  Form                                9-6
 9-2        Landfill Safety Checklist                                9-9
 9-3        Daily Waste Receipt Form                                 9-11
 9-4        Monthly Activity Form                                    9-12
 9-5        Capital Cost Form                                        9-15
 9-6        Operating Cost Form                                      9-16
 9-7        Typical Hauling Costs                                    9-20
 9-8        Typical Site Capital  Costs  for  Sludge Landfilling         9-23
 9-9        Typical Site Operating Costs  for Sludge Landfilling       9-24
 9-10      Typical Total  Site Costs for  Sludge Landfilling           9-25
10-1        Site Base Map for Example No.  1                          10-5
10-2        Site Development Map  for Example No.  1                   10-9
10-3        Operational Procedures for  Example No.  1                 10-12
10-4        Site Base Map for Example No.  2                         10-18
10-5        Site Development Plan for Example No. 2 - Wide Trench    10-21
10-6        Site Development Plan for Example No. 2 - Area Fill
           Mound                                                   10-22
11-1        Location of Case Study Sites                             11-2
11-2        Blue Plains Treatment Plant Flow Diagram                 11-6
11-3        Site Layout Plan - Montgomery County, MD                 11-11
11-4        Narrow Trench Operation - Montgomery  County, MD          11-13
11-5        Narrow Trench - Montgomery  County, MD                   11-14
11-6        Sludge Being Pumped Into Narrow Trench -  Montgomery
           County, MD                                              11-14
11-7        Application of Cover  and Excavation of New Trench  -
           Montgomery County, MD                                   11-15
11-8        Sludge Processing at  Originating Plant for North
           Shore Sanitary District                                 11-19
11-9        Flow Diagram:   Sludge Processing Unit at  Waukegan, IL    11-20
11-10      Comparative Costs of  Sludge Disposal  Without Phosphorus
           Removal at Waukegan,  IL                                 11-22
11-11      Site Layout Plan - Wuakegan,  IL                         11-26
11-12      Wide Trench Operation - Waukegan, IL                     11-28
11-13      Stockpiling Soil - Waukegan,  IL                         11-31
11-14      Unloading Sludge into Wide  Trenches - Waukegan, IL       11-31
11-15      Placing Interim Cover - Waukegan, IL                     11-32
11-16      Placing Final  Cover - Waukegan, IL                       11-32

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                      FIGURES  (Continued)
No.                                                                Page

11-17      Schematic of Operating  Practices at Colorado
           Springs,  CO                                            11-38
11-18      Wide Trench Operation - Colorado Springs, CO            11-39
11-19      Wide Trench - Colorado  Springs, CO                      11-42
11-20      Applying  Cover to Sludge Deposits - Colorado Springs,
           CO                                                     11-42
11-21      Site Layout Plan  at  Colorado  Springs, CO                11-43
11-22      Wastewater Treatment Flow Diagram for Denver, CO
           Metro Plant                                            11-45
11-23      Area Fill Layer Operation - Denver, CO                  11-49
11-24      Haul Vehicles - Denver, CO                             11-50
11-25      Sludge Mixing Equipment - Denver, CO                    11-50
11-26      Site Plan Layout  at  Lorton, VA                          11-56
11-27      Spreading Sludge  over Refuse  -  Lorton, VA               11-59
11-28      Sludge at Working Face  - Lorton, VA                     11-59
11-29      Covering  Sludge/Refuse  Mixture  - Lorton, VA             11-60
11-30      Graded Site -- Lorton, VA                               11-60
11-31      Codisposal Operation -  Lorton,  VA                       11-61
                                     xn

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                                 FOREWORD
The formation of the United States Environmental Protection Agency marked
a new era of environmental awareness in America.  This Agency's  goals  are
national in scope and  encompass  broad  responsibility in  the areas of  air
and water  pollution,  solid wastes,  pesticides, and  radiation.   A vital
part  of  EPA's  national   pollution   control   effort  is  the  constant
development and dissemination of new technology.

It  is  now clear  that  only the  most  effective design and  operation  of
pollution control facilities, using the latest  available techniques, will
be adequate to ensure continued  protection of the Nation's  resources.   It
is  essential  that   this  new  technology  be  incorporated    into   the
contemporary design  of pollution  control  facilities  to  achieve maximum
benefit of our pollution  control  expenditures.

The purpose  of  this  manual is to  provide the  engineering  community  and
related industry a new source  of information to be used  in the  planning,
design  and  operation  of  municipal  sludge  landfills.  It  is recognized
that there are a number of design  manuals,  manuals of standard  practice,
and design  guidelines currently available.    It is  the  intent  of this
manual to supplement this  existing body of knowledge.

Two major information  sources  were  used  to  compile data  for inclusion  in
this  manual.    The  first  was   a  comprehensive  literature  review that
included  publications, conference  proceedings,  unpublished   information
from   research   projects,  and   product   literature   from    equipment
manufacturers.   The  second  was case study  site  investigations  which
included  a  thorough   inspection  of   on-site   operating  procedures   and
interviews with landfill   operating and management personnel.

A committee of experts  in the planning, design,  and operation  of sludge
landfills  was  convened to review  and finalize  the manual  outline;   to
identify the needs of the  potential users; and  to discuss the  material  to
be  included  in  the  manual.   Interim  manual  drafts  were  reviewed  by  EPA
personnel and the above-mentioned committee.

This  manual  is  one of   several   available   from  Technology  Transfer   to
describe  technological  advances  and   new  information.    Future  editions
will be  issued as warranted by advancing state-of-the-art to  include  new
data  as  they  become  available,  and  to  revise   design  criteria   as
additional full-scale operational information is generated.

Companion  publications   describing   alternative  sludge   treatment   and
disposal methods are available in the  form of Technology Transfer Seminar
Handouts.  They may be obtained  by writing:

                                 U. S.  EPA
                                 ERIC
                                 26 W.  St. Clair
                                 Cincinnati,  Ohio  45268
                                  xi ii

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                                CHAPTER  1

                               INTRODUCTION


1,1  Sludge Disposal Alternatives


Wastewater  authorities  today are  faced with  a  dilemma.    As  improved
treatment  technologies,  more  stringent   regulatory   requirements,   and
increasing  flows  all   produce  greater quantities  of  sludge,   phased
prohibition of ocean dumping,  other  regulatory constraints,  and  spiral ing
costs  are  combining to  limit sludge disposal  alternatives.   Wastewater
authorities are effectively limited  to two  methods of disposal:


     1.  Conversion processes  (incineration,  pyrolysis, and  composting)

     2.  Land disposal  (landspreading and landfill ing)


Many  communities  have  found   conversion processes  to  be  quite costly.
Specifically, incineration is  becoming more costly because of energy cost
escalations  and  stringent  air  emission  regulations.    Whereas   sludge
incineration  appeared  quite  attractive  when  capital  costs  were  financed
with Federal  and State  funds,  operating  expenses are now a burden for  the
local  taxpayer.    For  this   reason  some communities  have  closed  their
incinerators  and implemented  other disposal  alternatives.
Composting, of  course,  produces  a beneficial  substance which can be  used
as  a  soil  conditioner  by  farmers,  homeowners,  highway  departments, and
park  authorities.   Initial  pilot and  plant  scale operations with sludge
composting have been  favorable.   However, composting  is  labor  intensive
and the  cost-effectiveness  of the  operation  is keyed to  the  market for
the resulting soil conditioner.
As noted above, landspreading and landfill ing are generally recognized as
the  two  types  of  land  disposal   for  sludge.    Landspreading  is  a
land-intensive disposal option and  its  use  may  be limited by the lack of
available open  land  areas in many  developed  areas.   Also  some sludges,
because  of  their   chemical  constituents,  may  not   be  suitable  for
landspreading.  For  these reasons,  landfilling  of  sludges  will  continue
to be a viable disposal alternative.
                                    1-1

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1.2   Sludge Landfills and  Solid  Waste Disposal  Facility Classification
      Criteria
Sludge  landfill ing  generally can  be defined  as  the  burying  of sludge;
i.e., the application  of  sludge to the  land  and  subsequent interment by
applying a layer of cover soil atop the  sludge.  To be defined as a land-
fill, the thickness of  the  soil  cover must be  greater  than the  depth of
the  plow  zone.   For  this  reason,  subsurface  injection  of sludge  is a
landspreading, not a landfill ing operation.
Classification Criteria for Solid Waste Disposal Facilities     are being
promulgated  by  EPA.    These  criteria  establish the  minimum performance
standards that solid  waste  land disposal  facilities  shall  meet  so as to
be classified as  posing no reasonable probability  of adverse affects on
health or the environment.  For all  solid waste disposal facilities, the
following areas are included:
    1.  Environmentally sensitive areas

        a.  Wetlands
        b.  Floodplains
        c.  Permafrost areas
        d.  Critical habitats of endangered  species
        e.  Recharge zones of sole source aquifers

    2.  Surface water

    3.  Groundwater

    4.  Air

    5.  Application on land used for the production of  food chain  crops

    6.  Disease vectors

    7.  Safety

        a.  Explosive gases
        b.  Toxic or asphyxiating gases
        c.  Fires
        d.  Bird hazards to aircraft
        e.  Uncontrolled access
                                    1-2

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Many of  the  topics considered in the  proposed  Criteria are addressed  by
State  and  local  regulations.   In some  cases  State and  local  regulations
will  address concerns  that  are  not covered  by  the  Criteria.   In  all
cases, the State and  local  requirements  should  be  consulted.
1.3  Objectives of Manual

The primary objective of this manual  is to  provide  general  guidance  and  a
source of  information  to  be used  in  the  planning,  design, and  operation
of  a   landfill  receiving  municipal   wastewater  treatment  plant  sludge.
Accordingly, typical procedures, case studies, and  examples are  presented
which  are  intended to serve  as aids to the  user.
Major   alternative  sludge   landfilling   methods   are   identified   and
described.  Guidance  is  given on the  selection  of the landfilling  method
which  is  best suited for  a given  combination  of sludge  characteristics
and site conditions.  For each  landfilling method, the following  features
are  addressed:    public participation  program,  site  selection,  design,
operation, monitoring,  completed site, management, and costs.
1.4  Scope of Manual


The manual represents  the  current  state-of-the-art with respect to  muni-
cipal  sludge  landfills.   Available  sources of  information  (both in  the
literature and  in  operating  practice)  were investigated and  incorporated
into the manual.   Where  specific  design criteria may seem lacking,  it  is
due to the limited  research  effort  which  has been  performed  on sludge
landfills, in comparison to other disposal  options  (e.g.,  landspreading).
The  variability   of   regulatory  requirements  from  state-to-state   and
year-to-year would have made  such  design  criteria  difficult  to  compile
and  easily  outdated.     Accordingly,   design   criteria and  operational
procedures for  existing  sludge landfills were  sometimes included  in  lieu
of prescribing  these criteria  and  procedures  for new sites.  This manual
is  not  intended   to  serve  as a  textbook  or  to  supplant  engineering
judgement.  On  an  actual  site  design,  sound engineering judgement should
be exercised either  to  verify  the  design criteria (if these are  included
in this  manual) or  initially  determine the criteria  (if  these  are  not
included).
Although  this  manual  is  in general  accordance with  the Classification
Criteria for Solid Waste Disposal Facilties, it  is not  intended to  define
policy  on  municipal  sludge landfills.   Further,  following  the  design
criteria  and  operating  procedures  of this  manual   will not  guarantee
compliance with the  Criteria.  However, the manual is intended to present
state-of-the-art  technology and adherence  of   a  sludge  landfill  to the
                                    1-3

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principles  presented  in  this  manual   will  probably  result  in   general
compliance with the  Criteria.  However, each landfill has a  unique  set  of
site conditions that must be addressed  individually.


This manual is directed at the disposal of sludges generated by municipal
wastewater treatment plants.   Sludges  generated by industrial  wastewater
treatment  plants  are  not  necessarily within  the  scope  of  this   manual.
However, many  industrial  sludges  are similar in composition to municipal
sludges  and  may be  handled  similarly.  Under  these  circumstances,  this
manual may be equally  useful for  industrial  sludge landfills.  Generally,
however,  if  industrial   sludges  contain  significant  concentrations  of
hazardous  constituents,  outside references,  and advice  should be  sought
for procedures specific to the handling of such hazardous wastes.
The manual  has been  confined  to identifying  and  describing three major
operational methods.   The sludge-only  landfill ing  methods  of trench  and
area  fill   are  given  emphasis.    Codisposal   landfill ing  of  sludge   and
refuse is also addressed.
1.5  Use of Manual
The information contained  in the manual  is  intended  for  use  by wastewater
authorities,  public  and  private  operators, environmental  planners,  and
consulting  engineers.    Because  of the  variety of  user backgrounds  and
needs, the manual has been organized  to  allow the  user to  locate  particu-
lar information as easily  as possible.
Most  users  have  information  needs  in  one  particular  phase  of  sludge
landfill ing.  Accordingly,  most  of the chapters of this manual  have  been
established  to  trace  the  chronological  development of a landfill.  Other
chapters are for  general  information  purposes.   As shown in   Figure  1-1,
many of the  tasks outlined  are concurrent.  While every attempt  has  been
made to make each chapter self-contained,  the manual  is best  used  in  its
entirety.


The following brief  chapter descriptions are provided as an  introduction
to the organization of  the  manual.
Chapter 2 - Public Participation  Program
The  objectives  of a public  participation program as  well  as  its  advan-
tages  and  disadvantages   are  discussed.    The  design  of   a   public
                                    1-4

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                               FIGURE  1-1

            SUGGESTED TIMING OF PLANNING,  DESIGN,  AND OPERATION
            ACTIVITIES FOR  SAMPLE  LANDFILL WITH  FIVE  YEAR LIFE

Activity
Public Participation Program
Landfilling Method Selection
Site Selection
Design
Construction
Operation
Monitoring

Year
1



	




2


•

-
«•



3









4









5









6









7









8








9








10








11








12








participation  program including  a  schedule of  activities  and a  list  of
target  groups  for  a  public  participation  programs  is  included.
Chapter 3 - Sludge Characteristics  and  Landfill ing  Methods
General  information  on  the  sources,  treatment, and  characteristics  of
municipal  sludge  is  presented.    Major  alternative  sludge  landfill ing
methods  (and  sub-methods)  are  defined and described. Guidance  is  given  on
the  selection of the landfill ing method  best  suited for  a  given set  of
sludge characteristics and  site  conditions.
£hajyte_r_ 4 - Site Selection
Major  criteria  that  affect  the selection  of  a  landfill  site are  identi-
fied.    A  general   procedure  for  applying  these  criteria to   a   site
selection  is  outlined.  A specific example  of  a  site  selection  process
using  a scoring system  is introduced.
Chapter 5 - Design
Sourcesofinformation  needed  for  designing   a  sludge   landfill  are
detailed.   Methodologies  for  performing  designs and  submitting design
documents are  outlined.   Design features for each landfill ing method are
discussed.   Environmental  factors are described  and appropriate control
mechanisms are detailed, including control of leachate and gas.
Chapter 6 - Operation
Operational  procedures  for  each  landfill ing  method are  described,  in-
cluding equipment  and personnel  requirements.    Illustrations  and brief
descriptions of specific  landfills  demonstrating alternative landfill ing
methods are included.
                                    1-5

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Chapter 7 - Monitoring
inapier / - Monitoring
Concepts for  conducting  groundwater,  surface  water,  and  gas  monitoring
are  presented.    Sample   point  location,  well  construction,  sampling
techniques, analytical methods, and data interpretation are discussed.


Chapter 8 - Completed Site
Procedures for site closure are outlined.  Characteristics of a completed
sludge landfill and uses of completed sites are discussed.
Chapter 9 - Management and Costs
Management functions  are  discussed.   Typical  costs  for  existing  sludge
landfills  are  presented.    A  comparison  of  costs  for  the  various
landfill ing methods is shown.
Chapter 10 - Design Examples
Using given  sludge  characteristics  and site  conditions,  design  features
are  outlined and  operational   procedures  established  for  three  sludge
landfills.   These three  examples  cover the full range  of  large  to small
treatment facilities.

Chapter 11 - Case Studies
Detailed descriptions of the site selection, public participation,design,
operation,  and  monitoring  programs  at five landfills  are  presented.   In
addition,  costs for  the  operations   are  discussed.  Summary tables  of
design, operation, and cost data for 22 sites are presented.
                                    1-6

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                                CHAPTER  2

                      PUBLIC  PARTICIPATION  PROGRAM
2.1  Introduction
Traditionally,  little  effort  has been made to  involve the public  in  en-
gineering  projects.    Where  exceptions  exist,  the emphasis  has been  on
developing  public  acceptance  programs.   The  term "acceptance",  however,
precisely  conveys  the kind of  role the  public  was  expected  to play  in
these  programs—that  of  a passive recipient of information geared  to  win
general  approval  so  that the engineer could  proceed  with  the  best  pos-
sible  technical design.   But  this type  of  approach  will  no longer  work.
The  public expects  to  play  an  active  part  in  environmental  decision-
making as  both  the  Clean Water  Act of 1977  (PL  95-217) and the  Resource
Conservation and Recovery Act of  1976  (PL 94-580)  mandate  public involve-
ment  mechanisms  and  activities.   Therefore,  the  purpose of  a  public
participation program  (PPP)  in  the establishment  of  sludge landfills  is
to give  the  public  a  participatory role throughout planning,  design,  and
operation.  This chapter  details  the objectives of a public participation
program,  its  advantages  and  disadvantages, PPP  participants,  the  design
of a  program,  timing  of public  participation  activities, and  areas  of
public concern  in sludge  landfill ing.


2.2  Objectives of a Public Participation Program


The objectives  of a public participation  program  are:

    1.   Promoting  full   public  understanding  of  the  need  for  a  sludge
         landfill and the  principles of its  operation

    2.   Keeping the  public  well-informed on the  status of various  plan-
         ning, design, and operation activities

    3.   Soliciting  from  concerned  citizens  their relevant  opinions  and
         perceptions involving sludge landfill development

The key  to achieving these objectives is  the  maintenance  of continuous
two-way  communication  between  sludge  landfill  planners/designers/opera-
tors and the public.  A common  problem for engineers and public  officials
is the  assumption  that   educational,  informational,  and   other one-way
communication techniques provide  for  an  adequate dialogue.    When  de-
signing  a public  participation  program,  sufficient   mechanisms  must  be
provided  for meaningful  public  input  into  the  decision process   (see
Section  2.5,  Design  of a PPP).   It must  be  emphasized that  a  PPP will
increase  the lead  time  required  to  select,  design,  and construct  a
landfill.   This fact must be  considered when  initially  determining  the
need  for a new  site.
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2.3  Advantages and Disadvantages of a PPP
The utility  of  a public participation  program  is not universally  recog-
nized.    Admittedly,  there  are  disadvantages  as   well   as   advantages
associated with  public  participation  in sludge landfill decision-making.
The advantages of a PPP include  [1]:


     1.  An  increased likelihood of public approval  for the  final  plans

     2.  A method  of  providing  useful  information  to decision-makers,
         especially where  values or factors that  are not  easily  quanti-
         fied are concerned

     3.  Assurance that all issues are  fully and  carefully  considered

     4.  A safety valve  in  providing  a forum whereby suppressed  feelings
         can be  aired

     5.  Increased accountability by decision-makers

     6.  An  effective mechanism  to force decision-makers to  be  responsive
         to  issues beyond those  of the  immediate  project


The disadvantages of a PPP  include [1]:
     1.  A potential  for  confusion  of the issues since many new  perspec-
         tives may be introduced

     2.  A possibility  that  erroneous  information will  be disseminated
         from unknowledgeable participants

     3.  An added cost to the project due to  public involvement

     4.  Possible delays  in the project due to  public  involvement

     5.  A possibility  that  the effort will  not  involve the  appropriate
         people  or  that  citizens will  not  develop  an  interest  in  the
         project until it is too  late for changes to be  initiated

     6.  Public  resistance  to   sludge  landfill ing  may  still   be   high
         despite the  best efforts of  a PPP
Despite these  disadvantages,  a PPP  is well worth  the  extra cost as  more
expensive  project  delays   are probable  if  an  irate  populace becomes
involved late  in  the  process.  The benefits derived  from a PPP will,  in
the  long-run,  contribute  to  an  effective  decision-making  process  and
outweigh the disadvantages.
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2.4  PPP  Participants


When designing  a PPP,  it  is  imperative  to  organize  an  effective publicity
campaign  that  will  reach  the  appropriate  people  at the  proper  times
throughout  the  planning  process.  Special efforts  should be made to  in-
volve  groups  and individuals  who,  from  past  experience, have demonstrated
an  interest in  environmental  affairs or  those who  are  likely to be  di-
rectly affected by the proposed sludge landfill development.   Developing
a  list of  interested  persons and organizations  for formal   and  informal
notifications and  contacts  is a good way to ensure  public  participation.
Contacting  the  following  groups  and  individuals  should  be part  of any  PPP
[1]:

     1.   Local  elected officials

     2.   State  and  local  government  agencies,  including  planning  commis-
          sions, councils  of government, and  individual  agencies

     3.   State  and local  public works personnel

     4.   Conservation/environmental  groups

     5.   Business  and  industrial  groups,  including  Chambers of  Commerce
          and selected trade and  industrial associations

     6.   Property  owners and users  of proposed  sites  and  neighboring
          areas

     7.   Service clubs  and  civic organizations,  including  the League  of
          Women  Voters, etc.

     8.   Media,  including newspapers, radio, television,  etc.


Depending upon  the  particular circumstances in  each  area,  the following
groups can also  be contacted, where  appropriate:


     1.   State  elected officials

     2.  Federal agencies

     3.  Farm organizations

     4.  Educational institutions,  including universities,  high  schools,
         and vocational schools

     5.  Professional groups  and organizations

     6.  Other groups and organizations, possibly including various urban
         groups, economic opportunity  groups,  political  clubs  and asso-
         ciations,  etc.


                                   2-3

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     7.  Labor unions

     8.  Key individuals who do not express their  preferences  through,  or
         participate in, any groups or  organizations


Identifying and contacting these  groups is only a first step.  A  special
effort  must  be made  to ensure  that  the  particularly important  people,
(such  as  influential  individuals, people who  are  most  likely  to  have
strong feelings about the site, and the media)  are not  only  informed, but
convinced of the  validity of the  sludge landfill project.   It  is  crucial
that as many of these key  groups  as possible support the  sludge  landfill
and speak out in  favor  of it during the public  participation program.


It is  important that  local  officials are  notified  about the  project  be-
fore the issue enters the  field of public debate.   Again,  this  approach
will  allow officials to form a more  objective  opinion about  the  project
and will prepare  them for inquiries from the  public.
Identifying  specific  groups  and  individuals  as  targets  for  public  in-
volvement  efforts  helps  to  focus  time  and  money  on  the  most  likely
participants, to  focus  the objectives  of the PPP,  and  to interpret  how
well the various  involvement  mechanisms are  working.
2.5  Design of a PPP
The PPP should  be  tailored  to each particular situation in terms  of  cost
and scale.   A certain minimum  effort  should be  put  into every  partici-
pation program,  but  within  a basic framework, appropriateness and  flexi-
bility are  the  keys.  For  example,  it makes little  sense  to expend  the
same amount of  time  and dollars  for  a  program involving  a  sludge  landfill
site on  a  totally unused  piece of  land  25  mi   (40  km)  from the  nearest
neighbor as  compared with a  site  in a densely  populated  urban  area.   A
common sense  approach in determining  the  number and frequency of  public
involvement mechanisms is recommended.


There are various  stages  in  the  sludge  landfill  development  process where
public  participation is  critical.   In  order  to  be most  effective,  a
majority of this involvement  should  come  in  the  beginning  of  the  planning
process  when public  input   has  the greatest potential   for  shaping  the
final  plan.   It  is important to determine the limits to public and poli-
tical  acceptability.  By  doing  so  early,  the public  plays  a  constructive,
as  opposed  to  a reactive,  role  in  decision-making.   This  section  will
discuss  the  critical planning  stages  where  public input is  particularly
important  and  the appropriate  public  participation mechanisms  at  each
stage.
                                    2-4

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     2,5.1  Initial Planning Stage


During the initial planning  stage,  the  scope  and scale of the entire PPP
should be  established.   In  addition, the  organization of PPP components
and the use of  PPP mechanisms should be  determined.   This determination
should recognize  the  existence  of  two  general  types  of  PPP mechanisms:
(1)  interaction  techniques  which  promote  two-way  communication  and (2)
educational/informational  activities  which represent  one-way communica-
tion  from officials  to the public.   Officials  at   this  point  may be
operating  authorities,   elected  officials,  engineering  consultants,  or
even public relations firms.


Initially, the major  activities  of this stage are  mostly informational/
educational.  The  public should be  informed  of the purpose  of  a  sludge
landfill,  the  need for  one  in their community, the  general  design and
operation  principles,  the  projected  final    land  use,  potential  for
creation  of  new jobs,  etc.    In addition, the rationale  for selecting
sludge landfilling over  alternative  methods such as sludge incineration,
landspreading, or  composting  should  be explained  to  the public  at the
outset.   As  initial  site  investigations get  underway,   two-way  public
involvement activities become important.  The  following mechanisms  should
be organized during this stage [2]:
         Public Officials  Workshop.   The  purpose  of this  meeting  is to
         aquaint  the  concerned officials  with the  technical  considera-
         tions  relevant  to  landfilling  and to  obtain  input  from  local
         officials  on appropriate  timing  of  activities  and  areas  of
         potential public concern.

        Advisory Committee.  The  role of this  group  is  to help organize
        citizen support for the proposed plan, to act as a sounding board
        in providing  citizen reactions  to  various  proposals,  and  to take
        an active part  in  decision-making.   The  group  should  include
        representatives  of   local    government   departments,   community
        organizations, private industry, and others.  Consultant progress
        reports  can  be  presented   during   these   meetings   and  later
        pub!icized.

        Mailing list.  Comprehensive  mailing  lists  are  the foundation of
        an information output  program.   They  must  be representative of a
        a broad cross-section  of groups  and  individuals  and  a constant
        effort is  required to  expand  and update them if they  are  to be
        effective.

        Liaison/contact  persons.   These  positions  should  be  held  by
        personswfioare  actively  involved  in the  landfill  decision-
        making  process;   e.g.,  a  consulting   engineer,   public  works
        official,   or  other  comparably   informed  individual.    In  large
        municipalities it may  be  advantageous  to  hire  an  individual  to
                                     2-5

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    handle  public  relations.  These  people  are   indispensable  for
    receiving  input,  answering  questions,  expanding  mailing lists,
    and generally being responsive.   They ensure  that logs are kept
    of all questions and that issues of general concern are directed
    to the appropriate people for consideration.

5.  Media program.  This  involves  organizing  an effective publicity
    campaign through the  use of  various  media.  The media should be
    contacted as  early  as possible and every  effort  should  be made
    to convince them of both the  need  for a sludge landfill  as well
    as the effectiveness  of  such  landfills before the topic  becomes
    an emotional  issue.   In this way,  objective  treatment  of  the
    issue by the  media  is more likely.   Again,  the  extent  of this
    program depends upon the particular situation.  Various channels
    include:

    a.  Newspapers.   A  series  of  informative  articles   on  sludge
        landfiITing can be timed to appear throughout the  project to
        sustain public  interest  and  serve as  an educational  tool.
        Each article  or  news  release can  also  transmit  hard  news
        such as notices  of public meetings,  or articles   describing
        events  at  public meetings.

    b.  Television.  This method can be very expensive, but can also
        T5everyuseful  in  transmitting  information.    However,
        through careful planning,  some free coverage  of the  project
        can  probably  be   arranged  through  news   programs,  public
        service announcements, or station  editorials.

    c.  Advertisements.  Full-page newspaper advertisements could be
        used to relate  complex  information.  They can incorporate  a
        mailback  feature  to  highlight  citizen concerns, and  solicit
        participation of  interested individuals.

    d.  Posters,  brochures,  or  displays.   These  can be  highly  ef-
        fectiveeducationaltools,especially  when  particularly
        creative and put  in high traffic  areas  or given wide distri-
        bution.

    e.  Radio advertisements or  informational  talks.   The radio can
        be used to  advertise events  or information in much the same
        way that newspapers are used.

6.  Classroom educational  materials.   This can be  an effective way
    of educating school children and their  parents.  A more economi-
    cal approach  than  presentations  in each individual  school  is to
    design special  newsletters  and brochures  that  can  also  be dis-
    tributed to other audiences.
                              2-6

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     2.5.2  Site Selection Stage
The  major  activities   of  the  initial  planning  stage  are   preparatory
mechanisms  for the  site selection stage.   The  procedure for  site  selec-
tion  generally  involves  a preliminary  screening of  numerous  potential
sites after  which  several  sites  are  selected  for more detailed  investi-
gation.   These  selected  sites  should  be  subjected  to  intense  public
scrutiny.    It  is  at  this point  that public  participation   can  play  a
particularly  formative  role  in  determing  the   final  site,   design  and
operation procedures, etc.


The majority of  public  interest  and   involvement  occurs  during the  site
selection stage.   It  is  important to remember  that  the most vocal  and
organized protests also  occur  during  the  site selection process.   There-
fore, the  major  thrust  of the PPP  should  come during this  stage,  es-
pecially  in the form  of  two-way communication  techniques.    Major  PPP
activities to be emphasized during this stage include:
     1.  Public meetings.  These are an excellent mechanism for  providing
         public  information,  receiving  input,  and  achieving one-to-one
         contact  between  consultants, local  officials, and  the public.
         They  are  normally  less  structured  than   public  hearings  and
         therefore,  more  likely  to  result  in  dialogue.   Generally,  a
         series of  such  meetings are held  in different locations within
         the planning area to provide  maximum opportunity for attendance
         by the public.   It  is  a good arena  for  the use of  audio-visual
         presentations.   These  meetings  work especially  well  when there
         are concrete  issues to be  discussed,  and  should   be  timed to
         coincide with  particularly criticial  periods in  the  decision-
         making process.  For example, the public at these meetings could
         screen the  site  selection criteria  or  even  rate  the  candidate
         sites   against  those  selected criteria.    The more successful
         meetings are usually a result of heavy advance work.   Overcoming
         public apathy can be  difficult,  but is  critically  important in
         these   early  planning  stages.     Consultant  contracts  should
         clearly specify the  number of public meetings to be  held because
         it is  often costly and time-consuming to prepare for them.

     2.  Workshops.   Generally,  these have positive results although they
         are not widely used  because of low turnout.  Such groups usually
         involve citizens  being  given courses  of  instruction  by agency
         staff, and  then addressing specific work efforts on the basis of
         such instruction.  Basically  workshops  are an  educational  tool
         with interaction features.

     3.  Radio  talk-shows.  Many communities  have local  radio talk shows
         where  residents can  call in and  voice their opinions.  The con-
         sultant and/or a local  official   could give a  short  presentation
         on the landfill  plan  and then field callers' questions.  This is
         a  good opportunity  to  dispel some  misinformation  but  views  of
         the callers are  not necessarily  representative of those  of  the
         general  public.

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     2.5.3  Selected Site and Design Stage
In this  stage, the  landfill  site  is  selected and  detailed  site  design
begins.  Generally,  the  number of  participants  involved  may  drop  off  in
this  stage,  but the  level  of activity  may substantially  increase.    No
matter how active the  public  has  been  up to this point,  nearby  residents
of  the  site  are   not  going  to  be  happy with   the  siting   decision.
Participation  efforts should  shift to  focus  on this  particular  group.
Giving these  people  a role in site design  will  alleviate some  hostility
and,  in  the   long-run,  improve  the  public's opinion  of the   proposed
operation.  Appropriate activities  in  this  stage are:


     1.  Tours/field  trips.   These  are useful  activities  for  special
         interest  groups,   such  as  residents  near  the  selected  sludge
         landfill site,  and the  press.   Before  the proposed  landfill  is
         opened, a tour of  an existing operational  sludge  landfill  should
         be made.  This can be far  more  effective than countless  abstract
         discussions.  After  the proposed  landfill  is  opened,  tours  can
         be  offered  of   this  site  to   educational  and other   groups.
         Arranging  for aerial views  of  proposed and existing  sites  for
         small  groups  by chartering a  plane can  be  especially effective.

     2.  Audio-visual  presentations.   These can  be  quite  useful  at  public
         information  meetings to  reach people  missed by the field  trips.
         The  effectiveness  of this tool depends  on the  quality of  the
         script  and  visuals, but  again,  can  do  a great  deal   towards
         dispelling  much of  the  misinformation  about  sludge   landfills
         based  on past experience with improperly run sites.

     3.  Task  forces.  The  purpose  of  these groups  is to  recommend  design
         procedures  in areas  of  particular  concern  for the public.   This
         group  could  be  a  sub-group of  the Advisory Committee  or  a  com-
         mittee  made up  of  residents  near the  site.   The  group  should
         have  a  technical  orientation  in order to be most effective,  but
         should  still  represent the various interest groups.

     4.  Formal  public  hearings.    Although  at  least  one  is  usually
         required by law,  a  public  hearing is usually only a formality.
         They  tend to  be structured procedures,  involving  prior  notifica-
         tion,  placing of  materials  in   depositories  for citizen  review
         prior  to the  hearing,  and a formal hearing agenda.  The  hearing
         itself  usually  takes the  form  of  a  presentation by the  consul-
         tants,  followed  by statements  from the  citizens in attendance.
         Questions are normally allowed, but argumentative discussion and
         "debates" are discouraged  because  of  time  limitations.   Sponsors
         tend  to prefer  to  adopt  a  "listening"  posture and  allow  the
         public  to  express itself  without  challenge.   This  kind  of  de-
         tached  attitude  tends to  generate a  great deal  of hostility  in
         the  public.   It conveys the message that the public  is  powerless
         to  change  engineering decisions and  this  is  precisely the  type
                                   2-8

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          of  message that a  PPP  is .supposed to  dissipate.   Since  public
          hearings  are usually  held in  the  site  selection  stage  before
          adoption  of  the final  design plan, they  provide an  insufficient
          means  of legitimate  citizen  involvement  in  the complete  plan-
          ning,  design,   and  operation   decision-making  process.     The
          responsiveness  of  a  public hearing  can  be  enhanced  by  having
          elected  officials  chairing  or at   least  particiating  in  the
          process.   Nevertheless,   public  hearings  perform  their  proper
          legal  and  review functions only as  part  of a  total  PPP.
     2.5.4   Construction  and  Operation  Stage
The  role  of  the  public  in  this  stage  is  limited,  but  the  actions  of engi-
neers  and sludge landfill  operators  are extremely important.   It  is  in
this stage that  the  sludge landfill  developers must  "make  good"  on their
assurances  of  running  a  well-operated, well-maintained   site.    Public
confidence   in  local   officials  can  be  reinforced  through  the  proper
handling  of  sludge landfill  development.  Otherwise,  it will  be extremely
difficult  to  establish public  support   for  this  or any  future  sludge
landfill.
Public  involvement  at  this  stage will  most likely mainly consist  of  com-
plaints  related  to  construction and operation activities.  Mechanisms  to
handle  this  interaction  include:
     1.  Telephone  line.   This  is a good tool to register complaints  and
         concerns  and to  answer  questions.   It is  important  that  each
         call is followed  up with a  response  addressing  the  actions  taken
         to  alleviate the  problem.

     2.  Ombudsman  or representative.   This is an individual who has  the
         ear  of  the landfilloperators and can mediate  difficulties  that
         may  arise  which  the  citizens  feel  are not  being  handled  ade-
         quately.
2.6  Timing of Public Participation Activities


Correct  timing  of the  public  participation activities  is  critical.   In
order  to be effective,  the program  must  be diversified  and  sustained.
Table 2-1 lists  suggested  timing  of  PPP mechanisms for a sample  15-month
landfill project.  Public  hearings are  formalities and, as such,  occur  at
the  beginning   and  end  of  the  planning  process.    Advisory Committee
meetings have the function of  providing a  forum for progress  reports and
regular  input  and,  therefore,  are scheduled to  occur from  every 2 to 3
months.    Public meetings  are  held  jointly  with   Advisory Committee
meetings  and  are timed  to obtain  input during  the   critical  points  in
decision-making.  Sufficient time is  allowed after each public  meeting  to
give  decision-  makers  time   to  react  to  comments  and   incorporate

                                   2-9

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suggestions  before final  determinations  are  made.   The  various  other
informational/educational  activities  are scheduled around the  public  and
advisory committee  meetings in order  to arouse  public interest  at  times
when input will be the most  valuable.
                               TABLE  2-1

           SUGGESTED TIMING OF PUBLIC  PARTICIPATION  ACTIVITIES
                       FOR SAMPLE  15-MONTH  PROJECT
PPP activities and mechanisms
Publ ic hearings
Publ ic meetings
Advisory Committee meetings
Mailing list development and
mai 1 i ngs
Availability of contact people
Newspaper articles
New releases
Audio-visual presentations
Newspaper advertisements
Posters, brochures, and
displays
Workshops
Radio talk-shows
Tours/field trips
Ombudsman
Task force
Telephone line
Decision stage
Initial
pi anni ng
Site selection
Design
Con-
struction
Operation
Month
T~





X









2
qp
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®


X
X
X







3





X


X

X




4


X












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X
X








6







X







/








X


X



8


X


X
X



X

X


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00




X







10








X


X



11


X



X





X



12
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14





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17











X


       joint meeting
As  stated  before,  a great deal of time  and  effort  is involved  in  a PPP.
When  budget  or time  restrictions prohibit  development  of an  ideal  pro-
gram,  it  is more  important  to  apply participation  techniques that  are
highly  effective.   Table 2-2  indicates  the relative capabilities  of the
suggested PPP activities.
2.7  Potential Areas  of  Public  Concern
A PPP should  serve  to dispel  any myths and misinformation  the  public may
have  concerning sludge  landfills.   It should  also address  the  irrever-
sible impacts  of  all  landfill  developments  and  other issues of concern in
the  environmental  impact  report  (see Chapter  4).   The  most  effective
participation  activities for  handling these issues are the  interaction
techniques  (i.e.,  public meetings,  tours/field  trips, and  displays  that
are manned  by  personnel  to  answer questions).   Some of  the concerns  most
likely  to  arise during  sludge landfill  development are listed  in  Table
2-3 along with  the  chapters that  address  these  issues  in the manual.
                                    2-10

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                           TABLE  2-2
  CAPABILITIES OF  PUBLIC  PARTICIPATION  TECHNIQUES
                                      Communication characteristics



Public participation technique
Public hearings
Publ ic meetings
Advisory Committee meetings
Mail ings
Contact persons
Newspaper articles
News releases
Audio-visual presentations
Newspaper advertisements
Posters, brochures, displays
Workshops
Radio talk shows
Tours/field trips
Onbudsman
Task force
Telephone line
L - low
M = medium
H = high
Level of
publ ic
contact
achi eved
M
M
L
M
L
H
H
M
H
H
L
H
L
L
L
H



Abil ity to
handle
specific
interest
L
L
H
M
H
L
L
L
L
L
H
M
H
H
H
M




Degree of
two-way
communication
L
M
H
L
H
L
L
L
L
M
H
H
H
H
H
M



                           TABLE  2-3
                        PUBLIC  CONCERNS
             Public concern
                                              Manual chapter
Pre-development  land uses and  subsequent
  environmental  impacts
Zoning problems/conflicting land uses
Groundwater pollution  and leachate
Gas migration
Vectors
Noise
Odor
Aesthetics -  including site visibility
Safety and health
Traffic
Spillage
Sedimentation  and erosion
Final land use
4 - Site Selection
4 - Site Selection
5 - Design
5 - De si g n
6 - Operation
6 - Operation
6 - Operation
6 - Operation
6 - Operation
6 - Operation
6 - Operation
6 - Operation
8 - Completed Site
                               2-11

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Local officials  should  be prepared to  handle  questions  concerning these
issues.  Obviously a majority  of  these  problems simply do not arise with
a well-operated,  efficiently-run  site,  and  this  fact should  be heavily
emphasized.   Also, since  each situation  is  unique,  mechanisms  to ease
these concerns have to  be tailored to  the  characteristics  of each site.
Local residents  and officials  should  be creative  in solving any problems
that  may  arise.   Above  all,  the attitude  of  local  officials   during
interactions with  citizens  is  extremely important  and must  at all times
be open and responsive.
2.8  Conclusion
Even the best program  to  involve the public in sludge landfill decision-
making may  not  alleviate  citizen dissatisfaction  or  anger.   This criti-
cism has  often  been cited  to justify only minimal  public participation
efforts.  However,  active public involvement  will  positively contribute
to the long-term political and public acceptability of any plan,  increase
public confidence  in local  officials,  and give citizens  a  ready oppor-
tunity to take  part  in  the land  management decisions of their community,
A PPP is a necessary part of  any sludge landfill program.
2.9  References

1.  Canter, L.   Environmental  Impact Assessment.  McGraw- Hill Book  Co.,
    New York, New York.  1977.  pp.  221, 222.

2.  CH2M  Hill,  Donahue  and  Associates,   et   al.     Preliminary   Draft:
    Community  Involvement  Program,  Metropolitan Sewerage District  of  the
    County  of Milwaukee,  Water Pollution  Abatement  Program.   December
    1977.  pp. A-l-A-8.
                                   2-12

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                                CHAPTER 3

             SLUDGE CHARACTERISTICS AND LANDFILLING METHODS
3.1  Purpose and Scope


The  purpose   of   this  chapter  is  to   present   pertinent  background
information  on municipal   wastewater   treatment   sludge  and  to  define
alternative sludge  landfill ing  methods.   Subsequently,  each landfill ing
method is described  in terms of the sludge  and  site conditions peculiar
to that method.  For a given combination of sludge and site conditions, a
single landfilling method  can be  selected.   Thus,  the landfilling method
selection (and  ultimately  the  design)   requires an  accurate  inventory of
the sludge characteristics.   Sections  3.2, 3.3, and  3.4  in  this chapter
discuss  sludge sources,  sludge treatment,  and sludge  characteristics,
respectively.    Section  3.5  defines  the  suitability  of  sludge  for
landfilling  and Section  3.6  discusses  alternative sludge  landfilling
methods  and  relates  them  to  suitable  sludge  characteristics  and  site
conditions.
It  should  be  noted  that  the  background  discussion  on  sludge  in  this
chapter has been kept brief.  For further information it may be advisable
to consult more detailed references on the subject.  Excellent references
include   "Sludge   Processing,   Transportation,   and   Disposal/Resource
Recovery:  A Planning Perspective" [1], "Process Design Manual for Sludge
Treatment  and  Disposal"  [2], and  "Seminar  Handout for  Sludge Treatment
and Disposal" [3],
3.2  SIudge Sources


In  the process  of  treating  wastewater,  solids  are  produced.   Various
treatment processes are designed to remove specific types of solids.


     3.2.1  Primary Treatment


Solids removed in primary treatment may include:


    1.  Screenings
    2.  Grit
    3.  Skimmings
    4.  Sludge
                                   3-1

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          3.2.1.1  Screenings
Screenings are  solids  such  as  rags, sticks, and  trash  in the raw waste-
water that are  removed on racks  or  bar  screens  placed at the head of the
treatment  plant.   The  quantity of  screenings  captured  in  a wastewater
treatment  plant will  vary depending upon the size  of the rack or screen
openings.  Screenings may be disposed  of separately or ground by hammer-
mills  or  shredders  and   added  to   the  wastewater  for  later  removal   in
sedimentation basins.  Screenings typically have  a  moisture  content of 85
to 95% and an organic content of 50 to 80% [1],
          3.2.1.2  Grit

Heavy inert material or  grit  such  as sand, silt, gravel, ashes, and  cof-
fee grounds are  selectively  removed  at  the head of the wastewater treat-
ment  plant,  either  by  velocity   control   in   simple   gravity  settling
chambers or by  buoyant  induction in air  flotation  tanks.   Grit is often
washed after collection  to reduce the concentration of organics which may
be  as  high  as   50%  of  the  total  grit  solids.   The high  organics  are
largely responsible for  the odors associated with  grit.
          3.2.1.3  Skimmings


Skimmings  consist  of  floatable  materials  collected  from  sedimentation
basins.  Skimmings may be subsequently digested, dewatered,  incinerated,
and/or landfilled.  When  skimmings are  unstabilized, cover may have  to  be
applied  immediately at  landfills  to  control odor.  Treatment  of  skimmings
in  digesters  is common,  however, particularly  with  mixed units.  Vacuum
filtration  dewatering  normally requires  prior mixing  with  more  readily
dewaterable materials  or  the  use  of  a  sludge  precoat on  the  filter.
          3.2.1.4  Sludge


Sludge  which accumulates  in  the  primary  clarifier  varies from  2 to  8%
solids  depending  on  the  operating  efficiency  of  the  clarifier  and  on
whether thickening is  used.   The  solids mass will  increase if there  is  a
substantial  amount  of  ground  garbage.    Primary  sludge  has  a  larger
particle  size  than that for  secondary  sludges.   Anaerobic digestion  and
the  various  dewatering techniques are  more  easily  applied to the  sludge
from  primary  clarifiers.    Nevertheless,  primary  sludge  is frequently
mixed with secondary  sludge  prior to  treatment.
                                    3-2

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     3.2.2  Secondary Treatment


The solids from trickling  filters  thicken  in the final  clarifier to 1 to
3% by weight,  the  denser solids resulting  from  low-loaded filters.  The
quantity  and  physical  characteristics  of  the solids from rotating bio-
logical  contactors are comparable  to those  from  trickling  filters.
Activated sludge  processes  use  a  suspension of aerobic microorganisms to
remove soluble and colloidal organic matter.  These organisms can vary in
type, concentration,  and  degree  of agglomeration depending upon the  phy-
sical features of the plant, types of pollutants, and degree of pollutant
level.   Sludges  from these  processes  range  from  about  0.5%  up  to 5%
solids  depending  on  the  operating  efficiency of  the clarifier  and on
whether the waste activated sludge is thickened.
Chemical addition to  primary  and  secondary treatment processes  increases
sludge  mass  (and usually  volume)  with the  additional  settled  colloidal
matter  and suspended  solids from the wastewater and  the settled  chemicals
themselves.   In  some instances,  however,  sludge   volumes  may actually
decrease  as  a  result of  increased  sludge  density.   Aluminum  and  iron
salts,  lime, and  organic  polymers  are  frequently employed to enhance the
removal  of  colloidal  material,   suspended   solids, and  phosphorus  in
primary, secondary, and tertiary processes.
     3.2.3  Industrial Sources
In extreme  cases,  industrial  influent to  municipal  wastewater treatment
plants can  have  three  harmful  effects.  They  may (1)  "upset" biological
treatment processes, (2) make sludge treatment and disposal difficult, or
(3)  creatf:  a   "pass-through"  effect  allowing  contaminants  to  reach
drinking  water  sources.  Usually,  the effects are  somewhat  less severe
and may  be  limited  to   (1)  increases  in  heavy  metal, refractory  organic,
or  salt  concentrations,  (2)   the  addition  of  slime,   or   (3)  higher
concentrations  of  granular  or  fibrous  material.   Viral   and bacterial
contamination  from  human  waste  does  not  change  significantly  with
increases in  industrial waste  fractions.    Pretreatment  regulations  [4]
now being promulgated  by EPA should reduce  or cease the harmful  effects
which industrial influents can have on municipal   plants.
3.3  Sludge Treatment


The  basic  sludge  treatment  processes  and  their  function  are  outlined
below [2].   Thereafter,  brief descriptions  of  the basic  processes are
presented.
                                    3-3

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     Unit Processes

     Thickening
     Stabilization
     Conditioning
     Dewatering
     Heat Drying and Conversion
Functions

Water removal
Volume reduction
Post process efficiencies
Blending

Pathogen destruction
Volume and weight reduction
Odor control
Putrescibil ity control
Gas production
Conversion

Improved dewatering or thickening
  rate
Improved solids capture
Improved compactability
Stabilization

Water removal
Volume and weight reduction
Improve ease of handling by con-
  version of liquid sludge to
  damp cake
Reduced fuel requirements for
  i nc i nerat i on/dryi ng

Destruction of sol ids/pathogens
Conversion
Recovery of dried sludge for use
  as soil conditioner
Stabilization
     3.3.1  Thickening
In sludge thickening  processes,  water  is extracted from the sludge, thus
increasing the  sludge solids content  and decreasing  the  sludge volume.
The most common methods for thickening are by gravity, air flotation, and
centrifugation.  If the sludge is to be  disposed via sludge-only landfil-
ling,  subsequent  dewatering  will  be  required.   Sludge  thickening may
provide a blending function in combining  and mixing primary and  secondary
sludges.  Sludge  thickeners  are  also used as  flow equalization tanks to
minimize the effect of  sludge quantity  fluctuations on subsequent treat-
ment processes.
                                    3-4

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     3.3.2  Stabilization


          3.3.2.1  Anaerobic Digestion
Anaerobic digestion is the decomposition of organic matter  in the  absence
of free oxygen.   This decomposition is  accompanied  by gasification  and
liquifaction  which  in  turn  lead  to stabilization,  colloidal   ^tract'i v
breakdown,  and  release   of  moisture  [5],  Depending  upon  the  initial
volatile solids  content  of the  sludge  to be treated, anaerobic  digestion
can  achieve a  50 to  70% reduction in  volatile  solids.    The  prim?.  '
purposes of anaerobic digestion [5]  are  to:
     1.  Prevent nuisances by decomposing organic  solids to a more  stable
         form.

     2.  Reduce  sludge mass by  converting  organic  solids to  gases  and
         1iquids.

     3.  Reduce pathogenic organisms.
Other possible uses that anaerogic digesters have performed are:

     1.  Reduction of volume by concentrating the remaining solids  into a
         denser sludge.

     2.  Storage  of  sludge  to  accommodate  fluctuations  in  wastewattt
         flows  and   to  permit   flexibility   in  subsequent  dcwatering
         operations.

     3.  Homogenization  of   sludge   solids  to   facilitate  subsequent-
         handling procedures.
          3.3.2.2  Aerobic Digestion


Aerobic  digestion,  which  takes  place  in  the  presence  of  free  oxygen
produces  a  final  material  consisting  of  inorganics  and  volatile  solids
that resist further biological degradation [1].


     3.3.3  Conditioning
Sludge conditioning improves the dewaterability of the sludge by changing
its chemical and physical characteristics.
                                   3-5

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     3.3.3.1  Sludge Conditioners

The  use  of  additives  for  sludge  conditioning  is   widely  applied  to
increase the  productivity  of mechanical  dewatering equipment  and obtain
greater   flexibility   in   subsequent   sludge  treatment   and   disposal
processes.   Conditioning  additives such as ferric  chloride,  lime, alum,
chlorine,  organic polymers,  and  ash  are  used  for  coagulation  of  the
sludge solids and release of bound water [1],  Generally, polymer treated
sludges tend  to  be  sticky,  slick,  and  less  workable  than  other sludges
and  frequently   require   special   operational   considerations   at  the
landfill.  Moreover, some conditioned sludges are corrosive.


          3.3.3.2  Elutriation

Elutriation,  which  involves  mixing  of  digested sludge  with water  and
resettling,  improves  the  dewatering characteristics  of the  sludge.   It
also  reduces the chemical  conditioning  requirements  by  reducing  the
alkalinity of the sludge,  thereby  reducing the amount of ferric chloride
and  lime  required  if  inorganic  conditioning  is  elected.    Elutriation
should, however,  be  used  in conjunction with polyelectrolytes  to settle
the fine solids and reduce recirculation.
          3.3.3.3  Heat Treatment
Heat treatment is a conditioning process that involves heating the sludge
for  short  periods of  time under  pressure.   Heat  treatment  results  in
coagulation of the  sludge solids,  breakdown of  the  gel  structure of the
sludge, and reduction  of  the  water  affinity of the  sludge solids.  Thus,
the  sludge  is sterilized,  and generally  readily dewatered  without  the
addition  of  conditioning  chemicals  [1].    However,  heat  treatment   will
solubilize organics  and  produce a liquid  sidestream  which may sometimes
cause problems.   Further,  although  the sludge produced by heat treatment
is practically deodorized, the  process itself can be quite malodorous.


     3.3.4  Dewatering
There  are  several  methods  available  for dewatering  sludges  at  present.
They  include  vacuum  filters, centrifuges,  filter  presses,  belt  presses,
lagoons,  and  sand drying  beds.   Sludge dewatering  processes  achieve a
degree  of  water  removal  immediately  between  those  of thickening   and
drying.   Dewatered sludge  solids  of 15 to  40% are  common  with organic
sludges,  and  values  of 45%  or  more  can be  achieved  with some  inorganic
sludges [6][7].
                                    3-6

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          3.3.4.1  Vacuum  Filtration
Vacuum  filtration  is  the most commonly used mechanical dewatering  method
in the  United States.  With chemical  conditioning,  the  solids  capture  can
produce a filter cake that ranges from  15 to 25%.
          3.3.4.2  Centrifugation
Centrifugation  is  used in both thickening  and  dewatering operations  and
usually  in  conjunction with  chemical  conditioning.   Centrifugation  can
prpduce  dewatered  cakes  generally comparable to those obtained by  vacuum
filtration  [6].    Centrifugation  has  several   advantages   over   vacuum
filtration; it  is  simple, compact,  and totally  enclosed  (thereby reducing
odor  problems  in  the  solids  handling  facilities)   [5].    Typically,
Centrifugation  cake  solids  contents range from  10 to 30%, with values  of
40% or more possible [7].  When Centrifugation  is  not done in  conjunction
with chemical  conditioning, solids  capture  can  be  a  problem.
          3.3.4.3  Pressure Filtration

Sludge  dewatering by  means  of a  filter  press  is  a  batch  operation.
Sludge  is pumped  into  the  press and passes  through  feed holes along the
length  of  the filter.   As the  press  is  closed by  either  electrical   or
hydraulic means,  water  is  pressed out  of the  feed  sludge and  is dis-
charged through filtrate drain  holes.   Solids of 30  to  50% are  reported
in the  literature; however this  figure may  be misleading since solids may
be  substantially  increased  through the  addition  of  conditioner  solids
          3.3.4.4  Belt Presses
Belt  presses,  a relatively  recent  innovation,  produce a  broad  range of
solids, depending on the design  of  the  press  and  the nature of the feed.
Solids ranging from 15 to 40% may be achieved with this process [3].
          3.3.4.5  Lagoons and Drying Beds


Lagoons  and  sand  drying beds  can  be  used  to  both  store  and  dewater
sludge, although some stabilization usually occurs.  With suitable lagoon
depths,  retention  times, and climates,  sludge  can be  thickened  to  over
10% solids.  Sludge solids up to 40% have been reported in the literature
for long detention times [1].
                                    3-7

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      3.3.5  Drying and  Conversion
Sludge  conversion   processes  are  generally  thermal   techniques  and  are
intended to  reduce the  solids required  for final  disposal  or to recover a
resource.    Table   3-1  indicates  the  sludge   conversion  and   resource
recovery processes.   Obviously,  the  prevailing  air  pollution  regulations
and  fuel  costs   should  be  taken  into  account.    Thus,   high  costs  for
auxilliary fuels and  air pollution controls may  be  incurred.
                                  TABLE3-1

                           CONVERSION PROCESSES [2]
          Conversion Process
                              Pretreatment Required
                       Additional Processing
                      	Requirements	
          Established Processes

            Incineration
            Wet air oxidation


            Heat drying


          Experimental Processes

            Pyrolysis
            Incineration/
             chemical  recovery
Thickening and dewatering
Thickening


Thickening and dewatering
Thickening and dewatering
Thickening and dewatering
Landfill ash

Treat cooking liquor,
 landfill  ash

Use dried si udge as
 soil conditioner
Utilize by-products of
 gas, carbon, steam.
 Dispose of residue

Landfill ash. Recover
 lime fron recalcina-
 tion or heat in power
 boilers
           3.3.5.1    Incineration
Combustion  by  incineration  serves  as  a means of  reducing  total  sludge
volume.   End  products  of  combustion  are  usually water, carbon  dioxide,
sulfur  dioxide,  and  inert  ash  [6].    The  characteristics  of  ash  vary
according to  the sludge incinerated.  Table 3-2 summarizes  the content of
ash  from four treatment plants.   A  significant portion of  the ash  can be
used as a  sludge  conditioner.   The remaining  ash may  be landfilled,  but
it  should  be  noted  that  the  heavy metal  content  is,   of  course,  higher
than sludges  and consequently a  lower loading  rate  is  advisable.
                                        3-8

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                                TABLE  3-2

                  COMPOSITION  OF  VARIOUS  ASHES (%) [8]
             Element
                        Mi 11 creek
                                  Beckjord
                                            Tahoe
Kansas City
Zinc
Cadmium
Arsenic
Boron
Phosphorus
Iron
Molybdenum
Manganese
Aluminum
Beryl 1 lum
Copper
Silver
Nickel
Cobalt
Lead
Chromium
Vanadium
Barium
Strontium
Calcium
Silicon
Magnesium
Other
0.56
0.07
0.33
0,26
0.33
3.33
0.13
0.03
6.99
0.001
0.03
0.01
0.07
0.07
0.13
0.23
0.13
0.26
0.01
8.46
22.00
1.00
55.57
0.10
0.10
0.50
0.05
0.50
5.30
0.20
0.05
9.40
0.001
0.07
0.01
0.10
0.10
0.20
0.05
0.20
0.01
0.01
1.5
19.17
0.45
61.93
0.11
0.10
0.50
0.05
2.70
0.97
0.20
0.05
0.29
0.001
0.05
0.01
0.10
0.10
0.20
0.14
0.20
0.03
0.01
21.13
11.15
1.30
60.61
0.13
0.10
0.50
0.18
0.50
2.65
0.20
0.05
4.6
0.001
0.05
0.01
0.10
0.10
0.20
0.10
0.20
0.08
0.01
6.18
26.96
0.51
56.59
          3.3.5.2  Wet  Air  Oxidation

Wet air  oxidation  involves burning  of organic  matter  in the  absence of
flame and in the presence of  liquid  water.   Temperatures and pressures on
the order  of 400 to 600°F  (150 to 225°C)  and  1200  to  1800 psig  (8.3 x
lO^ to  1.2  x 10^  N/cm^)  are  used  for  complete  oxidation of  organics
[6].  Because it is  not  necessary  to  supply energy for  the latent heat of
vaporization  of  water,  wet air  oxidation  is particularly  applicable for
materials  like  organic  sludges  which  are  combustible  but  cannot  be
readily separated from  water.   A problem with  ash disposal  in the wet air
oxidation process is that  the ash  is conveyed  in  a  significant volume of
water.
          3.3.5.3  Heat  Drying
Heat  (flash)  drying  is  the instantaneous removal  of  moisture  from sludge
solids  by  introducing  them  into a  hot gas  stream.    Wet  sludge  from  a
dewatering process is mixed with  previously dried  sludge, pulverized, and
introduced into  the  dryer.  Drying by  the  hot  gases  from  the  furnace is
essentially complete, with the  sludge  having solids contents  in excess of
90%.   Initially,  dried sludge  is  separated from the spent  gases  in  a
cyclone.   Subsequently,  it  may  be  (1) mixed  with  wet  sludge from  the
dewatering process,  (2)  stored  for  use as  soil  conditioner,  (3)  incin-
erated, or (4) handled  in  other  ways.
                                    3-9

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          3.3.5.4  Pyrolysis
Pyrolysis  is  defined  as  the  gasification  and/or  liquefaction  of  the
combustible elements  in  sludge by heat  in  the total  absence  of  oxygen.
Most of  the combustion  process  is carried  out  within  a  closed  reactor
chamber,  normally  at  temperatures  lower  than  in  incinerators.   End
products of the process are gases, pyroligneous acids and tars,  and char.
Generally, part of the solids may  be used as  a fuel  and part can  be used
as a filter aid.  The  remaining  solids  must  be disposed.  Most  so-called
pyrolysis systems on-line today are actually partial pyrolysis or  starved
air combustion.   Partial  pyrolysis uses less than the stoichiometric air
requirements but does allow some oxygen to enter the system.
          3.3.5.5  Lime Recalcination
The  process  of  recalcining  involves  incinerating the  dewatered sludge
containing calcium  which  drives off water,  organics,  and  carbon dioxide
and leaves calcium oxide (quicklime).  After coagulating raw wastewaters,
the inert solid  fraction can be removed  before recalcination using a wet
centrifugation  classification   system.    This  inert  solid  removal  must
occur to prevent solids buildup within the wastewater treatment  process.
3.4  Sludge Characteristics


The following characteristics of sludge are discussed  in this section:


    1.  Sol ids content
    2.  Solids characteristics
    3.  Pathogens
    4.  Heavy metals
    5.  Nitrogen


     3.4.1  Solids Content
The  solids  content  of  sludge  is  dependent on  its  respective treatment
source  (i.e.,  primary,  secondary,  etc.)  and on the various sludge treat-
ment  processes  (stabilization, dewatering,  etc.).    The  efficiency  of
various  dewatering  processes  for   increasing  the   solids  content   is
critical.   For example, if a vacuum  filtration  unit  designed to produce
sludge  with 25%  solids,  instead  produced  sludge with  a solids content
ranging  from  15 to 20%,  severe operational problems  could  occur at  the
                                    3-10

-------
landfill
landfill
occur.
   Only  by  incorporating  flexibility  into  the  design of  the
can a  site handle  the variations  in sludge  that may  commonly
     3.4.2  Solids  Characteristics
The reaction  of  the  macroscopic and microscopic  particles in sludge  is  a
function  of  (1)  particle  size  and distribution,  (2)  particle  configura-
tion,  (3)  density and  (4) other  factors  such  as  the  microorganisms  or
free radicals  present.   Particle  size  and  distribution and configuration
of  individual  particles  are  dependent   upon  the  sources  of  sludge.
Particles  may take  on  a  fibrous, spherical,  helical, planar, or  cubic
configuration.   Particle  characteristics  impact  on  sludge stability  and
consistency.


Solids may be further classified  as  volatile or  non-volatile.   Volatile
solids are a measure  of  the  amount of  organic matter  present  in the  solid
fraction of sludge.   The organic matter may  be  ultimately broken  down  by
bacteria,  producing  methane  gas  via  anaerobic   digestion   or   other
chemical,  physical,  or  biological  processes.  Table 3-3 outlines  typical
values  for volatile  solids  content  and  other  parameters  for  raw  and
anaerobically  digested  primary  sludge.
                                TABLE 3-3

          TYPICAL COMPOSITION  OF  RAW AND ANAEROBICALLY DIGESTED
                           PRIMARY SLUDGES [9]
Item
Total dry solids (TS), %
Volatile sol ids (% of TS)
Grease of fats (ether soluble,
% of TS)
Protein (X of TS)
Nitrogen (N, % of TS)
Phosphorus (PjOB, % of TS)
Potash (K2o, % of TS)
Cellulose (% of TS)
Iron (not as sulfide)
Silica (SlOo, % of TS)
pH
Alkalinity (mg/1 as CaCOj)
Organic acids (mg/1 as HAc)
Thermal content (BTU/lb)
Raw Primary
Range
2-7
60-80
6-30

20-30
K5-4
0.8-2.8
0-1
8-15
2-4
15-20
5-8
500-1,500
200-2,000
6,800-10,000
Sludge
Typical
4
65
—

25
2.5
1.6
0.4
10
2.5
—
6
600
500
7,600a
Anaerobical ly
Digested
Primary Sludge
Range Typical
6-20 10
30-60 40
5-20

15-20 18
1.6-6 3
1.5-4 2.5
0-3 1
8-15 10
3-8 4
10-20
6.7-7.5 7
2,000-3,500 3,000
100-600 200
2,700-6,800 4,000°
         Note: — means data not shown in reference cited.

                1 BTU/lb = 0.556 cal/kg

         a  Based  on 65% volatile matter

         b  Based  on 40X volatile matter
                                    3-11

-------
The volume of  sludge  produced at a treatment  facility is dependent upon
the influent wastewater  characteristics,  the  efficiency of the processes
to  reduce  pollutants, and  the type  of sludge  treatment process.   For
example, dewatering  processes reduce  sludge  volumes  by  removing water,
thus reducing  the overall  weight  of the sludge.   Table 3-4  outlines the
quantities of  sludge produced  from  various treatment processes.


The addition of  polymers to sludges will  create  a more viscous, sticky,
slippery material that can cause handling  difficulties.   If polymers have
been added  to  the sludge,  a higher solids content  may  be  required for
a specific landfill ing method.
     3.4.3  Pathogens
Most sludge treatment processes significantly reduce the number of patho-
gens  and  decrease  the  chances  for  pathogenic  contamination.   Current
research indicates that undigested  sludge stabilized with lime to a  final
pH between 10 and 11 disposed in narrow trenches is not thought to pose  a
serious hazard  [9][10],    Earlier  works  produced  similar  results;   fecal
coliforms and pathogenic  salmonella bacteria  were  not  detected more than
a  few in.  (cm)  into  soils outside  of  entrenched  sludges at  any time
during a two-year period  following  entrenchment [11].
     3.4.4  Heavy Metals


One  of  the  largest  contributors of  heavy  metals to municipal wastewater
treatment plants has  been  industry.   Most  heavy metals in wastewater  are
removed  by  conventional   treatment  processes  and  concentrated  in   the
sludge.   Treatment  plants should  analyze  their sludges to determine  the
concentrations  of  heavy metals.  Typical  concentrations  of  heavy metals
and  other constituents in raw and digested  municipal  wastewater sludge
are  listed in Table 3-5.
The  movement of  heavy metals  through the  soil   is  enhanced  by  acidic
conditions.   For  this  reason, lime  (CaO) is  added  to  sludge  prior  to
dewatering  to  raise pH levels to  10  or 11 [12].   Generally,  metals  did
not  leach  from  entrenched sludge  into  soils  as long as  the pH  remained
near  neutral  [9][10].    On  the  other  hand,  for  entrenched,   unlimed
sludges,  the soil  and  sludge became  acidic  due  to  the  formation  of
nitrates  and sulfates, and the extent  of heavy metal movement increased
C113C13].
                                    3-12

-------
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-------
                                 TABLE  3-5

      CHEMICAL COMPOSITION  OF MUNICIPAL WASTEWATER SLUDGES3 [14]
Component Units
Total N tb
NH4-N
NO,-N
P J
K
Cd
Mg
Fe
Mn mg/kgb
B
Hg
Cu
Zn
Nl
Pb
Cd
Number ot
samples Range
191
103
45
189
192
193
189
165
143
109
78
205
208
165
189
189
0.1-17.6
0.1- 6.8
0.1- 0.5
0.1-14.3
0.1- 2.6
0.1-25.0
0.1- 2.0
0.1-15.3
18-7,100
4-760
0.5-10,600
84-10,400
101-27,800
2- 3,520
13-19,700
3- 3,410
Median
3.3
0.1
0.1
2.3
0.3
3.9
0.5
1.1
260
33
5
850
1,740
82
500
16
Coefficient of
Mean variability, %c
3.9
0.7
0.1
2.5
0.4
4.9
0.5
1.3
380
77
733
1,210
2,790
320
1,360
110
85
171
158
61
99
87
75
148
209
162
232
138
134
162
177
157
          a Data are from numerous types of sludges (anaerobic, aerobic, activated, lagoon,
              etc.) in seven states:  Wisconsin, Michigan, New Hampshire, New Jersey, Illinois,
              Minnesota, Ohio

          b Percent or mg/kg oven-dry solids basis.

          c Standard deviation as a percentage of mean. Number of samples on which this is
              based may not be the same as for other columns.
      3.4.5  Nitrogen
The  nitrogen  species   in   sludge  represents   a  source  of  groundwater
pollution    [11].   Due  to  the  many  mechanisms  associated  with  nitrogen
movement,   it  is  difficult  to   predict  the  risk  of  pollution.     The
potential   for  groundwater  pollution is  significantly  affected  by  the
total  quantity  of  nitrogen   present   and   the  species,  which  include
nitrogen,   ammonia,  nitrate,  and  nitrite.    Generally,  nitrate  is  the
principal  species  of concern and  is  relatively  mobile in most soil  types.
Aerobic  conditions  facilitate  microbial  conversion   of  other  nitrogen
species  to  nitrate,  and  thus,  increase  the  possibility   for  nitrogen
movement.    Therefore,  disposal   methods  providing  anaerobic  conditions
inhibit  nitrogen movement  and  allow  microbial   destruction  of  pathogens
[11].
3.5   Suitability  of  Sludge for Landfill ing
In  determining the  suitability  of  sludge for  landfill ing, a determination
should  be made of the sludge sources and treatment.  Analyses  should also
                                      3-14

-------
be  performed  on the sludge  to  determine  relevant characteristics.   This
information is  needed  in  order  that  a full  assessment can be made of  its
suitability for landfill ing.   Not  all  wastewater  treatment  sludges  are
suitable for  landfill ing  due to either  odor or operational problems.  An
assessment of the  suitability of various  sludge  types has been  included
as  Table 3-6.


As  shown,  only  dewatered  sludges (having  solids contents  greater than or
equal  to  15%)  are  suitable  for   disposal   in   sludge-only   landfills.
Sludges  having  solids  contents  less than  15% usually  will  not support
cover material.  Obviously,  the addition of  soil  to a low-solids sludge
may act as a  bulking agent  and  produce  a  sludge suitable  for disposal at
sludge-only landfills.   However, soil  bulking operations are  generally
not  cost-effective  on  sludges with  solids  less  than  15%.    Further
dewatering  should  be  performed at  the   treatment  plant  if  sludge-only
landfilling is  the  disposal  option   selected.   Low-solids sludge (having
solids contents  as  low as  3%)  are   suitable  for  codisposal  landfilling.
However,  sludge moisture should  not exceed  the  absorptive  capacity of
refuse at  a  codisposal  landfill.  Accordingly,  low-solids sludge should
be  received at  such sites only  if  it constitutes  a  small percentage of
the total waste landfilled.
Generally,  only  stabilized  sludges  are  recommended  for  landfilling and
some degree of stabilization should  occur  if landfilling is the  selected
disposal  option.   However,  since stabilization  is not  required in all
states, suggested procedures  for  landfilling such sludges are described.


The  following section  describes  handling  and  operating  practices for
typical sludges.  Sludge  ash as  well  as  other wastewater treatment  plant
solids  such as  screenings, grit, and  skimmings  are disposed essentially
in the  same manner.   Specific handling  of  these wastes  is described  in
Chapter 6, Operation.
3.6  Sludge Landfilling Methods
The purpose of this  section  is  to  identify and describe several alterna-
tive methods and sub-methods for sludge landfilling.  These include:

     1.  Sludge-only trench

         a. Narrow trench
         b. Wide trench

     2.  Sludge-only area fill

         a. Area fill mound
         b. Area fill layer
         c. Diked containment

                                   3-15

-------
                                 TABLE  3-6

              SUITABILITY  OF  SLUDGES FOR  LANDFILLING
Process
Thickening
Gravity
Flotation
Treatment
Aerobic
digestion
Anaerobic
digestion
Incineration
Wet oxidation
Heat
Lime
stabil ization
Dewatering
Drying beds
Vacuum filter
Pressure
filtration
Centrifugation
Heat drying
Feed

Primary
WAS
Primary and WAS
Digested primary
Digested primary and WAS
Primary and WAS
WAS with chemical s
WAS without chemicals

Primary, thickened
Primary and WAS, thickened
Primary, thickened
Primary and WAS thickened
Primary, dewatered
Primary and WAS, dewatered
Primary or primary and WAS
Any, thickened
Primary, thickened
Primary and WAS, thickened

Any, digested
Any, lime stabilization
Primary, lime conditioned
Digested, lime conditioned
Digested, lime conditioned
Digested
Digested, lime conditioned
Digested
SI udge-only
landf illing
Suitability Reason

NS
NS
NS
NS
NS
NS
NS
NS

NS
NS
NS
NS
S
S
NS
NS
NS
NS

S
S
S
S
s
s
s
s

OD, OP
OD, OP
OD, OP
OP
OP
OD, OP
OP
OD, OP

OP
OP
OP
OP
—
00, OP
OD.OP
OP
OP

—
--
--
—
—
Codisposal
landf il 1 ing
Suitability Reason

NS
NS
NS
MS
MS
NS
NS
NS

MS
MS
MS
MS
S
S
MS
MS
MS
MS

S
S
s
s
s
s
s
s

OD,
OD,
OD,
OP
OP
OD,
OD,
OD,

OP
OP
OP
OP
--
OD,
OD,
OP
OP

--
—
--
--
__

OP
OP
OP
OP
OP
OP




OP
OP







WAS = Waste Activated Sludge
NS  = Not Suitable
MS  = Marginally Suitable
S  - Suitable
OD  = Odor Problems
OP  = Operational Problems
                                       3-16

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      3.   Codisposal

          a.  SIudge/refuse  mixture
          b.  SIudge/soil  mixture


The  above-listed  alternatives  were  found  to  be an  appropriate classifica-
tion  of  major  sludge landfill ing methods.  Other  methods  were  considered
and  some do  exist in practice.  However,  these other methods  either  (1)
did  not   afford  sufficient protection  of  the  environment,  (2) were  not
practical,  or  (3)  were  similar in many  aspects  to  the  methods  listed
above.
 In  this section,  each method  is  defined and  subsequently described  in
 terms  of  sludge  and  site   conditions   specific  to  that  method.    In
 addition,  design  criteria are identified  for  each method.  The  criteria
 suggested  for each  method are  based  on  experiences  at  numerous  sludge
 landfills  which  embrace  a broad  range  of  sludge  and  site  conditions.
 These  criteria  should  be valid  for  the majority  of  sludge  landfill
 applications.   However,  design criteria should  be qualified  as  being
 "typical"  or  "recommended".    Variations   are  employed  and  may   be
 appropriate  in some  cases.    For example,  the  range   of  sludge  solids
 contents  recommended  for  each  method  in  this  section  may vary  somewhat
 depending   on  the   sludge   source,  treatment,   and  characteristics.
 Specifically,  a  sludge treated  with polymers  is  more  slippery  and  less
 stable;  consequently  it  will   require  a higher  solids  content  to  be
 landfilled  in the  same manner  as  a  sludge  not  treated  with  polymers.
 Nevertheless,  the  criteria   suggested  by this  section can   serve  as  a
 starting  point.    It   is  recommended  that  field  tests  be  performed  to
 ensure  that   an  operation based  on  the  criteria  in  this  section  will
 function properly  for  a  given  sludge and  site.


     3.6.1  Sludge-Only  Trench


 For  sludge-only  trenches, subsurface excavation  is  required  so  that
 sludge can be placed  entirely below  the original ground surface.   Trench
 applications  require that  groundwater  and  bedrock  be sufficiently deep  so
 as to allow excavation  and still maintain  sufficient buffer soils between
 the bottom of  sludge deposits  and the  top  of groundwater or bedrock.


 In trench applications, soil   is  used only for  cover and  is not used  as  a
 sludge  bulking agent.    The  sludge   is  usually dumped directly into the
trench from haul  vehicles.  On-site  equipment  is  normally used only for
trench excavation and cover application;  it is  not  normally used  to  haul,
 push, layer, mound, or otherwise come  into contact with  the sludge.
                                   3-17

-------
Although in some  cases  cover application may be  less  frequent, cover  is
normally applied  over sludge  the  same day that it  is  received.  Because
of the frequency  of cover, odor control  is optimized; therefore, trenches
are  more appropriate  for unstabilized  or  low-stabilized  sludges  than
other landfill ing methods.  The soil excavated during trench construction
provides  quantities  which   are   almost  always   sufficient  for  cover
applications.  Accordingly, soil importation is seldom required in trench
applications.
Two  sub-methods  have been  identified  under trench applications.   These
include  (1)  narrow  trench and  (Z)  wide  trench.   Narrow  trenches  are
defined  as  having  widths  less  than  10  ft (3.0  m);  wide  trenches  are
defined  as  having widths  greater than  10 ft  (3.0 m).   The  depth  and
length of both narrow and wide trenches are variable and dependent upon a
number  of  factors.    Trench  depth   is   a function  of  (1)  depth  to
groundwater  and  bedrock,   (2)   sidewall   stability,   and  (3)  equipment
limitations.    Trench  length  is virtually   unlimited,  but   inevitably
dependent  upon  property  boundaries   and  other   site conditions.    In
addition, trench  length may  be  limited  by the  need  to  discontinue  the
trench for a short distance or  place  a  dike within the trench to contain
a low-solids sludge and prevent  it from flowing throughout the trench.


          3.6.1.1  Narrow Trench
As stated previously, a narrow trench has a width of less than 10 ft  (3.0
m).   Sludge  is  usually disposed  in  a  single  application  and  a single
layer  of  cover soil  is  applied  atop this  sludge.   Narrow  trenches are
usually  excavated  by  equipment  based  on solid  ground adjacent  to the
trench  and  equipment  does  not  enter  the  excavation.    Accordingly,
backhoes, excavators,  and  trenching machines are  particularly useful  in
narrow  trench operations.    Excavated  material  is usually   immediately
applied  as  cover  over  an  adjacent   sludge-filled   trench.    However,
occasionally,  it  is  stockpiled  alongside the  trench  from which  it was
excavated for  subsequent  application  as cover over that  trench.     Cover
material is then applied  by equipment  also  based on solid ground outside
of the  trench.  Relevant  sludge and site  conditions  as well  as design
criteria are presented  in the following tabulation.
     Sludge and Site Conditions


        Sludge solids content   - 15-20% for 2-3 ft  (0.6-0.9 m) widths
                                - 20-28% for 3-10 ft  (0.9-3.0 m) widths

        Sludge characteristics  - unstabilized or stabilized

        Hydrogeology            - deep groundwater and bedrock

        Ground slopes           - <20%

                                    3-18

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     Design Criteria


        Trench  width             -  2-10  ft  (0.6-3.0 m)

        Bulking  required         -  no

        Cover soil  required      -  yes

        Cover soil  thickness     -  3-4 ft  (0.9-1.2 m)

        Imported  soil  required   -  no

        Sludge  application       -  1,200-5,600 yd3/acre
          rate                       (2,300-10,600 rrrYha)

        Equipment                -  backhoe  with  loader,  excavator,
                                    trenching machine
The  main  advantage of  a narrow trench  is  its ability  to handle  sludge
with  a  relatively  low solids content.  As shown  above,  a  2 to 3 ft  (0.6
to 0.9  m)  width  is required for sludge with  a solids content between  15
and 20%.   Normally, soil  applied  as cover over sludge of  such low  solids
would sink to the  bottom of the sludge.  However, because  of  the  narrow-
ness  of the trench,  the soil   cover  bridges  over  the sludge,  receiving
support from  solid ground on either side of  the  trench.    In  this  opera-
tion  cover is usually applied  in a  2 to 3 ft  (0.6 to  0.9 m) thickness.


A  3  to  10 ft (0.9  to 3.0  m)  width is more  appropriate  for   sludge  with
solids  contents  from  20 to  28%.   At  this width, the bridging effect  of
the  never soil   is non-existent.    However,   the  solids content  is  high
enough  to  support  cover.   In this  operation, cover is usually applied  in
a 3 to  n  ft (0.9 to 1.2  m)  thickness and dropped  from a minimum  height  to
minimize  the amount of  soil  that sinks  into  sludge deposits.


The  main  disadvantage  of  narrow  trench operations  is that  it  is  rela-
tively  land-intensive.   As  shown  above, typical  sludge application  rates
in actual  fill  areas  (including inter-trench  areas)  range from 1,200  to
5,600 yd3/acre  (2,300  to  10,600  m3/ha).    Generally,  application  rates
for  narrow trenches are less  than  for other  methods.   Another drawback
with  narrow trench  operations  is that  liners  are  impractical to  install.
          3.6.1.2  Wide Trench
As  stated  previously,  a wide  trench has a  width  of greater  than  10 ft
(3.0  m).    Wide  trenches  are  usually  excavated by  equipment operating
                                   3-19

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inside the trench.  Accordingly,  track  loaders,  draglines, scrapers, and
track  dozers   are   particularly  useful   in  wide   trench  operations.
Excavated material is usually  stockpiled  on  solid  ground adjacent to the
trench from  which it was  excavated  for subsequent  application  as cover
over  that  trench.   However,  occasionally it  is immediately  applied  as
cover over  an  adjacent  si udge-filled trench.   Relevant  sludge  and site
conditions  as  well   as  design criteria  are  presented  in  the  following
tabulation.
     Sludge and Site Conditions


        Sludge solids content    - 20-28% for land-based equipment
                                 - >28% for sludge-based equipment

        Sludge characteristics   - unstabilized or stabilized

        Hydrogeology             - deep groundwater and bedrock

        Ground slopes            - <10%


     Design Criteria


        Trench width             - >10 ft (3.0 m)

        Bulking required         - no

        Cover soil required      - yes

        Cover soil thickness     - 3-4 ft (0.9-1.2 m) for land-based
                                     equipment
                                 - 4-5 ft (1.2-1.5 m) for sludge-based
                                     equipment

        Imported soil required   - no

        Sludge application       - 3,200-14,500 yd3/acre
                                     (6,000-27,400 irrYha)

        Equipment                - track loader, dragline, scraper,
                                     track dozer
As shown above, cover material  may  be  applied  to wide trenches in either
of two  different  ways.   If its  solids  content is  from  20 to  28%,  the
sludge  in  the trench is  incapable  of supporting  equipment.   Therefore,
cover  should  be  applied  in a  3 to  4 ft  (0.9 to  1.2  m)  thickness  by
equipment based on  solid  undisturbed ground adjacent to  the  trench.   In
                                   3-20

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this way,  a wide trench  may  be  only  slightly  more  than  10  ft  (3.0  m)  wide
(if a  front-end loader  is  used  to  apply  cover)  or  up  to  50 ft  (15  m)  wide
(if a  dragline is  used  to  apply  cover).   Alternatively,  if its  solids
content  is 28%  or  more  covered  sludge  in  the   trench   is  capable  of
supporting  equipment.    Therefore,  cover should be  applied by  equipment
which  proceeds  out  over the  sludge  pushing  a 4  to 5 ft  (1.2  to  1.5  rr<)
thickness  of cover  before  it.   Track dozers  are the most  useful  piece  of
equipment  in this application.


As for  narrow  trenches,  wide trenches should be oriented  parallel  to  one
another  to minimize  inter-trench   areas.    Distances   between   trenches
should  be  only  large enough  so as to  provide sidewall  stability  as  well
as  adequate space  for  soil  stockpiles,  operating equipment,  and  haul
vehicles.
One  advantage of a  wide  trench is  that  it is  less  land-intensive  than
narrow  trenches.   Typical  sludge  application rates  range  from 3,200 to
14,500  yd3/acre  (6,000 to  27,400  nr/ha).   Another  advantage  of  a  wide
trench  is  that liners  can  be  installed  to contain  sludge  moisture  and
protect  the   groundwater.   Therefore,  excavation  may  proceed  closer to
bedrock  or  groundwater  in  wide  trenches  with   liners  than  in   narrow
trenches without such  protection.
One disadvantage  of  a wide trench is a  need  for  a higher solids  sludge,
with  solids  contents  at  20% and above.    It  should be noted that  sludges
with  a  solids content of  32% or  more  will   not  spread out  evenly in  a
trench when  dumped  from  atop the trench  sidewall.   If wide trenches  are
used  for  such  high  solids  sludge, haul  vehicles  should enter the  trench
and dump  the  sludge  directly onto the trench floor.  Another  disavantage
of  a  wide trench  is  its  need  for  flatter   terrain  than that  used  for
narrow trenches.  For wide trench applications  with sludge less than  32%
solids,  sludge  is dumped  from above and  spreads out  evenly  within  the
trench.   Accordingly,  the  trench floor  should  be nearly level, and this
can be more easily effected  when  located  in low relief  areas.


     3.6.2  Sludge-Only Area  Fill
For  sludge-only  area  fills, sludge  is  usually  placed above the  original
ground  surface.   Because  excavation is not  required and  sludge is  not
placed  below the  surface,  area  fill  applications are particularly useful
in  areas  with shallow  groundwater  or  bedrock.   The solids  content of
sludge  as  received  is  not  necessarily limited.   However,  because  the
sidewall containment  (available  in  a trench)  is lacking  and equipment
must be  supported  atop  the  sludge  in most area  fills,  sludge stability
and  bearing  capacity  must  be relatively  good.    To  achieve these quali-
ties, soil   is  usually mixed with the  sludge  as a bulking  agent.  Since
                                    3-21

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excavation  is  not usually  performed  in the  landfill ing  area, and  since
shallow groundwater  or  bedrock  may prevail, the large quantities  of  soil
required  usually must  be  imported  from  off-site  or hauled  from  other
locations on-site.
Because  filling  proceeds  above  the ground  surface, liners  can  be  more
readily installed at  area  fill  operations than at trench operations.   Of
course, because of the  likely proximity of groundwater or bedrock  to  the
ground  surface,  the   installation  of  a  liner  will   often  be required  at
area fills.  With or  without  liners,  surface runoff of moisture  from  the
sludge  and  contaminated rainwater should  be  expected  in greater  quanti-
ties at  area  fills,  and appropriate  surface  drainage  control  facilities
should be considered.
In area fills, the  landfill ing  area usually consists of several  consecu-
tive lifts or applications of sludge/soil mixture  and cover  soil.   As  for
any landfill, cover should be applied atop  all  sludge applications.   How-
ever, this cover  often  is applied  as necessary to provide  stability  for
additional lifts.  Because some time may  lapse  between  consecutive  sludge
applications, daily cover is  usually not provided and  stabilized  sludges
are better suited for area filling  than are  unstabilized sludges.
Three  sub-methods  have  been  identified  under  area  fill   applications.
These  include  (1) area  fill  mound, (2)  area  fill  layer,  and  (3)  diked
containment.    Each  of  these  three  sub-methods  are  described  subse-
quently.
          3.6.2.1  Area Fill Mound
In area fill  mound  applications, it  is  recommended  that the  solids  con-
tent  of  sludge received  at  the site  be no  lower  than 20%.   Sludge  is
mixed with a  soil bulking  agent  to  produce  a  mixture which  is  more  stable
and  has  greater bearing  capacity.   As  shown below,  appropriate bulking
ratios may  vary between  0.5  and 2  parts  soil  for each  part  of sludge.
The exact ratio employed  will  depend on the  solids content of the  sludge
as received  and the  need  for mound  stability and bearing capacity  (as
dictated by the number of  lifts  and  equipment weight).


The  sludge/soil  mixing  process  is  usually  performed  at one location  and
the mixture hauled to the  filling area.  At the filling  area,  the sludge/
soil   mixture  is stacked  into mounds  approximately 6  ft  (1.8  m)   high.
Cover material  is then  applied atop these mounds  in  a  minimum 3 ft  (0.9
m) thick application.  This cover thickness may be  increased to 5 ft  (1.5
m) if additional mounds are applied  atop the  first lift.  Relevant  sludge
and  site  conditions  as   well  as design  criteria  are  presented  in  the
following tabulation.
                                    3-22

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      Sludge  and  Site Conditions


         Sludge  solids content     - X?0%

         Sludge  characteristics   - stabilized

         Hydrogeology             - shallow groundwater or bedrock
                                      possible

         Ground  slopes            - suitable for steep terrain as long as
                                      an area is prepared  for mounding


      Design  Criteria


         Bulking  required          -yes

         Bulking  agent            - soil

         Bulking  ratio            - 0.5-2  soil:l  sludge

         Cover soil  required       - yes

         Cover soil  thickness      - 3  ft  (0.9 m)  of  interim
                                  - 1  ft  (0.3 m)  of  final

         Imported  soil  required    - yes

         Sludge application        - 3,000-14,000 yd3/acre
                                      (5,700-34,600  m3/ha)

         Equipment                 - track  loader,  backhoe  with  loader,
                                      track  dozer

Because  equiment  may pass atop  the sludge  in performing mixing,  mounding,
and  covering operations,  lightweight equipment with  swamp  pad  tracks  is
generally  recommended for area fill  mound  operations.  However,  heavier
wheel equipment  may be more  appropriate in  transporting bulking  material
to and from  soil  stockpiles.


An advantage of  the area  fill  mound  operation  is its good  land  utiliza-
tion.  Sludge application rates  are  relatively  high  at  3,000 to  14,000
yd3/acre  (5,700  to  26,400  m^/ha).    A  disadvantage  is   the   constant
need  to  push  and  stack  slumping  mounds.    For  this reason,  area  fill
mounds  often have   higher manpower  and  equipment  requirements.    Some
slumping  is  inevitable and  occurs particularly  in  high  rainfall areas
due  to   moisture  additions  to  the sludge.   Slumping can  sometimes  be
                                   3-23

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minimized by providing earthen containment of mounds where  possible.   For
example, area fill mound operations are usually conducted on  level  ground
to prevent mounds  from  flowing downhill.  However,  if a steeply sloping
site is selected,  a  level  mounding  area  could be prepared  into the  slope
and a sidewall created for containment of mounds on one  side.
          3.6.2.2  Area Fill Layer


In area  fill  layer applications, sludge  received  at the  site  may be  as
low as 15% solids.  Sludge  is  mixed  with  a soil  bulking agent to  produce
a mixture which is more stable and has greater bearing capacity.   Typical
bulking  ratios  range  from  0.25 to 1  part soil for  each  part sludge.   As
for area fill mounds, the  ratio  will  depend on the solids content of the
sludge as received and  the  need  for  layer stability and bearing capacity
(as dictated by the number  of  layers and  the  equipment weight).


This  mixing  process  may occur either at  a  separate  sludge dumping and
mixing area  or  in  the filling  area.   After  mixing  the sludge with  soil,
the mixture  is  spread evenly in  layers from 0.5 to 3  ft  (0.15  to 0.9  m)
thick.   This layering  usually  continues  for a  number  of  applications.
Interim  cover between consecutive layers may  be  applied  in  0.5  to  1  ft
(0.15 to 0.3 m)  thick applications.  Final  cover should  be from 2  to 4  ft
(0.6  to  1.2 m)  thick.   Relevant sludge  and site  conditions as  well  as
design criteria are presented  in  the following tabulation.
     Sludge and Site Conditions


        Sludge solids content    - XI5%

        Sludge characteristics   - stabilized

        Hydrogeology             - shallow  groundwater  or  bedrock
                                     possible

        Ground slopes            - suitable for medium  slopes  but  level
                                     ground preferred


     Design Criteria


        Bulking required         -yes

        Bulking agent            - soil

        Bulking ratio            - 0.25-1 soilrl  sludge
                                     3-24

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        Cover soil required       - yes

        Cover soil thickness      - 0.5-1  ft  (0.15-0.3  m)  of  interim
                                  - 2-4 ft  (0.6-1.2  m)

        Imported  soil required    - yes

        Sludge application        - 2,000-9,000 yd3/acre
                                      (3,800-17,000  mj/ha)

        Equipment                 - track  dozer,  grader,  track  loader


As  for mounding  operations,  equipment   will  also  pass atop  sludge  in
performing  mixing,  layering,  and   covering  functions.    Accordingly,
lightweight equipment with  swamp  pad tracks is generally recommended  for
area  fill  layer  operations.    However,   heavier  wheel  equipment  may  be
appropriate  for  hauling  soil.    Slopes  in  layering  areas   should   be
relatively flat to prevent the sludge from  flowing  downhill.   However,  if
the sludge solids content is high and/or  sufficient  bulking  soil  is used,
this  effect  can  be  prevented  and  layering performed  on  mildly  sloping
terrain.
An advantage of an area fill layer operation  is that  completed  fill  areas
are relatively  stable.  As a result, the  maintenance required is not  as
extensive  as  for  area fill mounds.   Accordingly,  manpower and equipment
requirements  are  less.    A  disadvantage  is  poor   land  utilization with
application  rates   from   2,000   to   9,000  yd^/acre  (3,780  to  17,000
irrYha).
          3.6.2.3  Diked Containment
In diked  containment applications,  sludge  is placed  entirely  above the
original  ground  surface.   Dikes  are constructed  on  level  ground  around
all  four  sides of  a containment  area.   Alternatively,  the containment
area may  be  placed  at the  toe of  a hill  so  that  the  steep slope can  be
utilized  as  containment  on  one   or  two  sides.   Dikes  would  then  be
constructed around the remaining sides.


Access  is provided to the top of the dikes so that haul vehicles  can  dump
sludge  directly  into the containment.   Interim  cover may  be  applied  at
certain points during the filling,  and final  cover should be applied  when
filling is discontinued.  Relevant sludge  and site conditions  as well  as
design criteria are  presented in the following tabulation.
                                    3-25

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     Sludge and Site Conditions
        Sludge sol ids content


        Sludge characteristics

        Hydrogeology


        Ground slopes
- 20-28% for land-based equipment
- >28% for sludge-based equipment

- unstabilized or stabilized

- shallow groundwater or bedrock
    possible

- suitable for steep terrain as long as
    a level area is prepared inside
    dikes
     Design Criteria
        Bulking required

        Bulking agent

        Bulking ratio

        Cover soil required

        Cover soil thickness
        Imported soil required

        Sludge application


        Equipment
- no, but sometimes used

- soil

- 0.25-1 soil :1 sludge

- yes

- 1-2 ft (0.3-0.6 m) of interim with
    land-based equipment
- 2-3 ft (0.6-0.9 m) of interim with
    sludge-based equipment
- 3-4 ft (0.9-1.2 m) of final with
    land-based equipment
- 4-5 ft (1.2-1.5 m) of final with
    sludge-based equipment

- yes

- 4,800-15,000 yd3/acre
    (9,100-28,400 rrrYha)

- dragline, track dozer, scraper
As shown above,  the  solids content of  sludge  received  at diked contain-
ments  should  be  a minimum  of 20%.    For  sludges with  solids contents
between 20 and  28%,  cover material should  be  applied  by equipment based
on solid ground atop the dikes.   For  this situation, a  dragline  is the
best equipment  for cover  application due to its long reach.  Thicknesses
should be 1 to  2 ft  (0.3 to 0.6 m) for  interim cover  and 3 to  4 ft  (0.9
to 1.2 m) for final cover.
                                    3-26

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For sludges  with  solids contents of 28% and above, cover  material  should
be applied by equipment  which  pushes  and  spreads  cover  soil  into  place as
it proceeds  put over the  sludge.   For this situation,  a  track dozer  is
the best  equipment  for  cover application.   Thicknesses  should be 2 to  3
ft (0.6  to 0.9 m)  for   interim  cover and 4 to  5 ft (1.2  to 1.5 m)  for
final cover.
Usually  diked  containment operations are  conducted  without the  addition
of  soil  bulking agents.   Occasionally, however,  soil  bulking  is  added.
Under  these circumstances,  soil  may  be  added  to   increase  the  solids
content  and allow the  operations described  above.
An  advantage of  this  method  is  that individual  diked  containments  are
relatively  large with typical  dimensions  of 50  to  100  ft  (15  to 30  m)
wide, 100 to 200 ft  (30 to 60  ft)  long,  and  10  to 30 ft  (3 to 9  m)  deep.
Accordingly,  efficient land  use  is .realized  with  sludge  loadjng  rates
varying  between  4,800 and  15,000  yd^/acre  (9,100  to 28,400  nf/ha).    A
disadvantage  of  diked  containment  is that the  depth  of  the fill  in con-
junction with the weight  of  interim  and  final cover,  places  a  significant
surcharge  on the sludge.   As a  result,  much of  the sludge moisture  is
squeezed  into surrounding dikes  and into the  floor  of  the containment.
Accordingly,  liners   and  other   leachate   controls   may   be  especially
appropriate  with diked containments  to collect  leachate  emissions.
     3.6.3  Codisposal
A codisposal  operation is defined as  the  receipt of  sludge  at a  refuse
landfill.   Two  sub-methods have been  identified  under codisposal  opera-
tions.   These  include  (1)   sludge/refuse  mixture  and  (2)   sludge/soil
mixture.
          3.6.3.1  Sludge/Refuse Mixture
In a sludge/refuse mixture  operation,  sludge is deposited at the working
face of the landfill  and  applied  atop  refuse.   The sludge and refuse are
then mixed as thoroughly  as  possible.   This  mixture is then spread, com-
pacted, and covered  in  the  usual  manner at  a  refuse  landfill.  Relevant
sludge and  site  conditions  as well  as design  criteria  are  presented  in
the following tabulation.
                                    3-27

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     Sludge and Site Conditions
        Sludge solids content

        Sludge characteristics

        Hydrogeology


        Ground slopes
- unstabilized or stabilized

- deep or shallow groundwater or
    bedrock

- <30%
     Design Criteria
        Bulking required

        Bulking agent

        Bulking ratio

        Cover soil required

        Cover soil thickness


        Imported  soil required

        Sludge application


        Equipment
- yes

- refuse

- 4-7 tons refuse:!  wet ton sludge

- yes

- 0.5-1 ft (0.15-0.3 m) of interim
- 2 ft (0.6 m) of final

- no

- 500-4,200 ydVacre
    (900-7,900 m3/ha)

- track dozer, track loader
As shown above, sludge with  solids  contents  as  low as 3% may be received
in such  operations.   Usually, such  sludge  is spray  applied  from  a tank
truck to a layer of refuse at the working  face.   The bulking ratio for a
3% solids  sludge should be  at  least 7  tons of refuse  to  1 wet  ton of
sludge  (7  Mg  of refuse  to  1 wet Mg  of sludge).   Usually,  only sludges
with  solids  contents  of  20% or  more  are   mixed  with  refuse  in  such
operations  and  fewer  operational   and environmental   problems  may  be
expected than  when  a  3% solids  sludge  is  received.   Also,  less bulking
agent is required and  ratios as  low as 4 tons of  refuse  to  1  wet ton of
sludge  (4 Mg of refuse to 1  Mg of sludge) are successfully practiced.


Also as  shown  above,  sludge  application rates for sludge/refuse mixtures
compare  favorably with other methods, despite the  fact that  sludge is  not
the only waste  being  disposed on the  land.   Application rates generally
range  from 500  to  4,200  yd3 of  sludge per  acre  (900  to  7,900  m6 of
sludge  per ha).
                                    3-28

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          3.6.3.2   Sludge/Soil  Mixture
In a  sludge/soil mixture  operation,  sludge  is  mixed  with  soil  and applied
as interim  or final cover  over completed  areas  of  the  refuse  landfill.
This  is not strictly  a  sludge landfill ing method since the  sludge  is  not
buried.  However,  it  is  a viable option for disposal of  sludge  at  refuse
landfills  which has  been performed  and  should  be  used  in many  cases.
Relevant  sludge  and  site  conditions  as  well   as  design  criteria  are
presented in  the following  tabulation.
     Sludge and Site Conditions
        Sludge  solids  content

        Sludge  characteristics

        Hydrogeology


        Ground  slopes


     Design Criteria
- >_ 20%

- stabilized

- deep or shallow groundwater or
    bedrock

- < 5%
        Bulking required

        Bulking agent

        Bulking ratio

        Cover soil required

        Imported  soil  required

        Sludge application

        Equi pment
- yes

- soil

- 1  soil :1 si udge

- no

- no

- 1,600 yd3/acre (3,000 m3/ha)

- tractor with disc
One advantage  of employing the siudge/soil  mixture  operation is that  it
removes sludge  from  the  working  face of the  landfill  where it may  cause
operational problems.  Other  advantages  are that the mixture can be used
to promote  vegetation  over completed fill  areas; a savings  in fertilizer
can be realized; and siltation and erosion  problems can  be  minimized.


One disadvantage of employing the sludge/soil mixture  is that  it  general-
ly has greater manpower and equipment requirements than  would  be  incurred
                                    3-29

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by  landfill ing  the same  sludge  quantity  at  the working  face.   Another
disadvantage is that since the sludge  is  not  completely  buried,  odors  may
be  more  severe  than for  sludge/refuse mixtures.   For  this reason, only
well  stabilized  sludges are  recommended  for use  in  sludge/soil mixture
operations.


     3.6.4  Sludge-Only or Codisposal


For a  variety of  reasons, consideration  should  be  given to using  codis-
posal   methods for  sludge  disposal  in  lieu of sludge-only  methods.   The
advantages of using an  existing  refuse landfill  instead of a  new sludge-
only landfill include:
     1.  Shorter time delay.   Processing of permits to dispose sludge  at
         an existing refuse  landfill  will  probably be quicker than  proc-
         essing permits for  a  new sludge-only site.  Also, since most  or
         all of the  site  preparation required  for sludge disposal   is  in
         place, delays for construction  may not occur.

     2.  Less  environmental  impact.    The  environmental  impact  (odors,
         traffic, aesthetics, water)  of  one codisposal site will  probably
         be less than the combined  impacts  from two separate  sites.

     3.  Less public opposition.   The public  is less  likely to resist  an
         expansion in the operations  of  one site than  it  is to  resist  the
         operation of a new  site.

     4.  Less cost.   Due  to economies  of  scale,   the  cost  of one  codis-
         posal  site will  probably be  less  than the combined costs  of  two
         separate sites.


Obviously, there are several  disadvantages  for refuse landfill operators
to consider when contemplating the  receipt  of  sludge.  These  include:

     1.  Odors may  increase  somewhat  depending upon  the  degree to  which
         the sludge is stabilized.

     2.  Leachate may  be  generated sooner  (if not already  existing)  or
         leachate quantities may  increase (if  already  existing).

     3.  Operational problems may  develop including equipment  slipping  or
         becoming  stuck  in  sludge, or  sludge  being   tracked  around  the
         site by equipment and haul vehicles.


Several  other  items  should  be  considered  by  a   refuse  landfill  before
receiving sludge.  These  include:
                                    3-30

-------
      1.   Pertinent   regulatory   authorities  should   be  consulted   to
          ascertain  whether sludge receipt is permissible.

      2.   Leachate   collection  and  treatment  systems  may  have  to  be
          enlarged  (if existing) or  installed  (if  not  existing)  to handle
          any increased  leachate quantities.

      3.   Leachate  treatment systems may have to  be upgraded to handle any
          change in  leachate quality.

      4.   A sufficient  volume of refuse should be delivered to the site so
          that  sufficient  absorption of sludge moisture can occur.

      5.   Ideally,  delivery  of sludge  and  refuse  should  occur  simulta-
          neously.   If not,  storage capacity must be  provided  for either
          sludge or refuse  so that  the  sludge can  be mixed with  refuse
          when  landfilled.

      6.   Controlled  dumping   of   refuse  should  occur  to  maximize  its
          absorptive  capacity  with  sludge.    Such  control  may  not  be
          attainable  when  the public  is  allowed  access  to  the  working
          face.
     3.6.5   Conclusion
 In  Section 3.6, an  attempt  has been  made to  identify  and describe  the
 major  sludge  landfilling  methods.   Sludge and  site conditions  as  well  as
 design  criteria have  been presented  for each  method.    Chapter  4  will
 discuss  the  considerations  and methodologies  employed  during the  site
 selection  process.
In practice, the  selection  of  a  landfilling  method  is  an  integral  part  of
the  site  selection  process.   Indeed,  it  is  imperative that the  landfil-
ling  method  be  known  prior  to  the  final  site  selection   since the
acceptability  of  a  given site is  contingent upon the  landfilling  method
to  be  employed.    By  the  same  token,  the  acceptability  of  a  given
landfilling  method  is  contingent upon  the  site  on  which  it  is  to  be
employed.   And, of  course,  the  acceptability of  a  given combination  of
landfilling method  and  site are  in turn contingent upon  the characteris-
tics of the sludge  received.   Obviously then, a  thorough  investigation  of
sludge  characteristics   should   be   performed   first,  with   concurrent
investigations  of sites  and  landfilling methods  to follow.


Tables 3-7  and  3-8  are compilations of the  conditions and criteria  pre-
sented previously for each  landfilling method.   They are  provided  to  give
guidance  during the investigation  of  alternative  sites  and  landfilling
methods.   It  is important  to  note  that  there may be  no  one best  method
                                    3-31

-------
for a  given  sludge or site.   Rather, these  considerations  and criteria
merely suggest  sites  and amenable landfill ing methods  that  can simplify
and  improve  the  design   and   operation  procedures  required  for  an
environmentally safe and cost-effective sludge landfill.
                               TABLE 3-7
                       SLUDGE AND SITE CONDITIONS
Method
Narrow trench
Wide trench
Area fill mound
Area fill layer
Diked containment
SI udge/ refuse mixture
Sludge/soil mixture
SI udge sol ids
content Sludge characteristics
15-28% Unstaoilized or
stabi 1 i zed
>20% Unstabilized or
stabil ized
>20% Stabilized
>lb% Unstabilized or
stabil ized
>20% Stabilized
>3% Unstabil ized or
stabi 1 i zed
>2(K Stabilized
Hydrogeol ogy
Deep groundwater
and bedrock
Deep groundwater
and bedrock
Shallow groundwater
or beorock
Shallow groundwater
or bedrock
Shallow groundwater
or bedrock
Deep or shallow
groundwater or
bedrock
Deep or shallow
groundwater or
bedrock
Ground
slope
<20%
<10l
Suitable for steep terrain
long as level area is pn
pared for mounding
Suitable for medium slopes
level ground preferred
Suitable for steep terrain
long as a level area is
prepared inside dikes
<30%
<5%



6S
bjt
as


3.7  References
1.   Wyatt, M.  J.  and  P. E.  White,  Jr.   Sludge  Processing, Transporta-
     tion,  and  Disposal/Resource Recovery:    A  Planning  Perspective.
     Report No.  EPA-WA-75-R024.  December 1975.

2.   Process Design Manual Sludge Treatment and Disposal.  U.S.  Environ-
     mental  Protection   Agency.     Technology  Transfer.     Report  No.
     EPA-625/1-74-006.   October 1974.

3.   Sludge  Treatment  and  Disposal, Part  I.    Introduction  and  Sludge
     Processing.   U.S.   Environmental  Protection  Agency.   Environmental
     Research  Information Center, Cincinnati, OH.   Seminar Handout.   May
     1978.

4.   General  Pretreatment Regulations  for Existing  and New  Sources of
     Pollution.  U.S. Environmental   Protection Agency.   Federal Register.
     June 26,  1978.  Part IV.

5.   Burd, R.  S.  A Study of  Sludge  Handling and Disposal.  U.S.  Depart-
     ment of the Interior.  FWPCA.   WP-20-4.  May 1968.
                                    3-32

-------
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                                                                        3-33

-------
6.   Weber, W.  J.   Physicochemical  Processes  for  Water Quality Control.
     Wiley-Interscience, New York, NY.  1972.

7.   SCS Engineers.   Review of Techniques  tor Treatment arid Disposal  of
     Phosphorous-Laden  Chemical  Sludges.    U.S.  Environmental  Protection
     Agency, Contract No. 68-03-2432.  1978.

8.   Smith, J.  E. Jr., et al.  Sludge Conoitioning with  Incineration  Ash.
     Presented  at the 27th  Purdue  Industrial  Waste Conference.  May  2-4,
     1972.

9.   Wastewater Engineering.  Metcalf & Eddy,  Inc.  McGraw-Hill  Book  Co.,
     New York,  NY.  1972.

10.  Walker, J. M., L. Ely, et al.  Sewage  Sludge  Entrenchment  System for
     Use by Small  Municipalities.   U.S.  Environmental Protection  Agency,
     National Environmental Research  Center,  Cincinnati,  OH.   1976.

11.  Walker,  J. M.,  W.  D.  Burge,  R.  L.  Chaney,  E.  Epstein,  and J.  D.
     Menzies.     Trench   Incorporation   of   Sewage  Sludge   in  Marginal
     Agricultural Land.  Report No. EPA-600/2-75-034.   September 1975.

12.  Report to  the  National Commission on  Water Quality on  the Environ-
     mental  Impact  of  the  Disposal   of  Wastewater Residuals.   Environ-
     mental Quality Systems, Inc., Rockville,  MD.  March  1976.


13.  Burge, W.  D. and  W.  N.  Cromer.   Virus  Survival  and  Movement  from
     Entrenched Sludge.  In:  Report  on Cooperative Research  Dealing  with
     Safe Utilization of Sludges (unpublished).  March  1977.   pp.  36.

14.  Sieger,  R.  B.  and  P.  M.  Mahoney.   Sludge  Transport  and  Disposal,
     Part  II.   Sludge  Disposal.   U.S.  Environmental  Protection  Agency.
     Environmental Research Information  Center,  Cincinnati, OH.   Seminar
     Handout.   May 1978.
                                    3-34

-------
                                CHAPTER 4

                             SITE SELECTION
4.1  Purpose and Scope
The  purpose  of  this  chapter is  to present  the technical  and economic
considerations relevant to  site  selection  and describe the methodologies
for  applying  these considerations  to  the  site  selection  process.   The
major divisions  of this chapter are:
    1.  Site Considerations

        a.  technical
        b.  economic

    2.  Selection Methodology

    3.  Example of Methodology
The first part of  this  chapter  is  directed at those considerations which
determine  the  suitability  of  a   site   for   sludge  landfill ing.    The
landfill ing method selected affects the suitability of a site  and this is
described in  Chapter  3, Sludge Characteristics  and  Landfill ing Methods.
Public  acceptance  also affects  the suitability  of  a  site  and  this  is
described in Chapter 2, Public Participation Program.  The second part of
this chapter  presents  a methodology for site  selection.   The  third part
of this  chapter  includes  an example  of  the methodology which will help
the  user  to   understand  a  general  procedure  for   selecting a   sludge
landfill site.
It is  important  to emphasize the  lead  time necessary to  select  a site.
The  permitting   process,   evaluation,  public   review,   purchase,  and
development  of  a  landfill  site  may  take a  year  or  more.    If  the
municipality does  not correctly anticipate the time requirements, overuse
and  abuse  of the  existing landfill  may  result; at  the  very  least  the
municipality will  be  forced into expensive storage or  transportation of
sludge.
4.2  Site Considerations
The technical considerations involved in selecting a sludge landfill site
span many  disciplines:    land  use  planning, economics,  engineering,  and


                                   4-1

-------
social  and  political
must be considered in
              fields.   Among  the  technical
              the evaluation process are:
                           considerations that
    1.  Site life and size
    2.  Topography
    3.  Surface water
    4.  Soils and geology
    5.  Groundwater
    6.  Vegetation
    7.  Site access
                                  8.  Land Use
                                  9.  Archaeological or
                                      historical significance
                                 10.  Environmentally sensitive
                                      areas
                                 11.  Costs
     4.2.1  Site Life and Size
The  site  life is determined  by the size  of the site,  the  quantity and
characteristics  of   the   sludge,   and  the   landfill ing  method.     In
determining the required size, one must realize that not all  the site can
be filled.  Thus, a site should be viewed  in the following terms:
    1.

    2.
Gross area.  The total area within the property boundaries.
Usable fill area,
        soil  stockpiles.
        to 70% of the gross
  Excludes  areas  for  buffers,  access  roads,  and
Typically the  usable fill  area can  consume 50
  area
Figure 4-1 demonstrates  calculations  used  to determine the required site
size  given   the   site  life,  landfill ing  method,   and   daily  sludge
generation.  Figure 4-2  on the other hand, calculates  the  site life given
the  usable  area,  sludge  quantity,  and landfill ing method.   Although  in
practice a municipality  will  usually  not  define the site  life initially,
a  minimum  acceptable  life  should be  established,  since
become less significant over an extended period.
                                                   start  up costs
The  landfill ing  method also  has  an impact  on  site life and  size.   For
example,  a  wide trench  method  uses   less  land  than  a  narrow trench
operation, and thus  provides  a  longer  site life, all  other factors being
equal.
     4.2.2  Topography
Since  a  relatively flat site  could  pond, and  an  excessively steep  site
could  erode  and create  operational  difficulties,  sludge  landfilling  is
                                    4-2

-------
                        FIGURE  4-1


        SAMPLE  CALCULATION:  AREA REQUIRED

 Given:

 1.   Waste volume = 60 yuj/day, 7 days/week, 29% so1 >-i sludge
 2.   Trench 1 ife - 10 yr3
 3.   Trench dimensions = 45 ft wide x  10 ft deep x  2UO ft long
 4.   Trench spacing = 10 ft of solid ground between  trenches
 5.   Buffer = 100 ft  minimum, froir ">able filling area to areperty  lire

 Solutions:

 !.   Trench volume needed:

     (60 yd3/day)x(365 days/yr)x(10 yrb) = 219,000 yd3

 2.   Number of trenches needed:

     (219,000 yd3)x(27 ft3/yd3)
     (45 ft x 10 ft x 200 ft)         = 65.7 trenches

 3.   Usable acreage needed:

     45 ft wide x 200 ft long trenches plus 10 ft between trenches
       = 55 ft x 210 ft grojs space for each trench

     (65.7 trencbes)x(55 ft x 210 ft trench) = T&  335 ft2
     (758 835 ft2)
     (43,560 ft^/acre  -= 17.4 acres

 4.   Minimum Gross Acreage Required:

     17.4 acres = 870 ft x 870 ft
     Minimum site size = (1,070 ft x 1,070 ft) + 25% for access
       roads, dumping pad, and miscellaneous uses =  33 acres
 1  ft =   0.305 m
 1  yd =   1.609 m
 1  acre = 0.405 ha
                        FIGURE  4-2


SAMPLE  CALCULATION:    SITE  LIFE  AVAILABLE

  Given:

  1.   Waste Volume =  45 yd3/day,  7  days/week,  22%  solids sludge
  2.   Usable fill  area = 6 acres
  3.   Trench dimensions = 10 ft  wide  x 5 ft  deep x 120 ft long
  4.   Trench spacing  = 5 ft of solid  ground  between trenches

  Calculations:

  1.   Number of  available trenches:

      Each trench will have area = 15 ft x  125 ft = 1,875 ft?

      Total acreage  = 6 acres =  261,360 ft2

      Number of trenches = 261,360 ft2'
                            1,875 ft'
                                       = 139  trenches
  2.  Trench volume  available:

     (139 trenches)x(]0 ft x 5 ft  x  120 ft)       1 vd3             ,
                   	___h	x   27ft3   • 30,089 yd3
  3.   Site life:

      30,889 yd3
      45 ydVday  =  686 days =  1.9 yrs
  1  ft =   0.305 m
  1  yd =   1.609 m
  1  acre = 0.405 ha
                             4-3

-------
usually limited to areas  that  have slopes greater
20%.    Again,  the  landfill ing  method  determines
operations are amenable to  a given topography.
than 1%  and  less  than
 to   some extent  what
     4.2.3  Surface Water
The  amount  and  nature  of surface  water -bodies  on  a  landfill   are  a
significant factor  in site  selection.    The  existing bodies  of surface
water and drainage  on  or near proposed  sites should  be  mapped and their
current and future  use considered.   Certain  areas such  as  wetlands and
flood  plains   should   be  avoided  if  at  all   possible   since  they  are
environmentally sensitive  areas [1].  Where it  is  necessary to use  either
wetlands or floodplains  the owner should be prepared to perform extensive
designs, provide operational controls of runoff and infiltration, prepare
environmental  reports, and spend additional time obtaining approvals from
regulatory agencies.
In addition, the  Clean  Water Act of 1977  requires  that  all  point source
discharges  of  pollutants (e.g.,  surface  leachate  or  leachate treatment
effluent) must comply with  NPDES  permits  issued for the facility.  Thus,
selection  of  a   site   with  surface   water  can  compound  design  and
operational  difficulties  and  increase  the  difficulty   in   securing  a
permit.  This should be  considered during the  selection process.


     4.2.4  Soils  and Geology

The  role of  soil  in  sludge  landfills  is  to provide  cover, attenuate
potential  contaminants, control  runoff  and  leachates,  and  serve  as  a
bulking  agent  (if the  sludge  characteristics  and   landfilling  method
warrant).   The  chemical  and  physical/hydraulic   properties  of  a   soil
determine   how   effective   it   will   be   in   performing   these  roles.
Accordingly,  relevant  soil   properties  that should  be noted  during the
selection process  are:
    1.  Physical/hydraulic  properties

          a.  Texture
          b.  Structure
          c.  Soil depth and  quantity
          d.  Permeabil ity/transmissivity

    2.  Chemical  properties

          a.  pH
          b.  Cation exchange capacity  (CEC)
                                    4-4

-------
In general,  a desirable  geology  will have  some combination  of deep and
fine-textured  soils.   The finer the  soil,  the less  depth  needed.  Sites
operating  on clay and  clay loams,  for  instance,  have  operated  success-
fully  with as  little  as  2  to 5  ft  (0.6  to 1.5  m) of  soil   separating
sludge  deposits from  the highest  groundwater  elevations.    Other soils
require a  considerably greater thickness.    The  amount  and  type  of soil
needed  depends on  the landfill ing  method  and the  characteristics of the
sludge  disposed  [2].   Figure 4-3 gives  the  textural  classifications used
by the U.S.  Department of Agriculture, Soil  Conservation Service  (SCS).
                                  FIGURE  4-3

              SOIL TEXTURAL  CLASSES  AND  GENERAL TERMINOLOGY
                        USED  IN  SOIL  DESCRIPTIONS
                   U S. STANDARD SIEVE NUMBERS
                    10  20  40  60    200
1 1 I I i i I Tl 1 1 1 1
i


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                    i   I    i   i	.1	I	I	1	L	L	J
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                                GRAIN SIZE, mm    O  o  O
                                     4-5

-------
Permeability  is  dependent  on  the  soil  texture  and  structure.    Again,
fine-grained,  poorly  structured  soils  have  the  lowest  permeabilities.
Table  4-1  and Figure 4-4  give  qualitative  ranges  for  classifying  soil
permeabilities.   Depending  on  the sludge characteristics,  a moderately
low  to low permeability  soil  is  desirable  for a  sludge  landfill  site,
although  proper  landfilling  has  been  observed in  relatively  permeable
soils.   As with texture, there  is  an  inverse  relationship  between  the
required  soil thickness  and  soil  permeability.
                                   TABLE  4-1

                          PERMEABILITY  CLASSES FOR
                             SATURATED  SOIL [3]
Soil  permeability (cm/s)
                                                      Class
               <4.2 x 10-5

               4.2 x 10-5 to 1.4 x 10-4

               1.4 x 10-4 to 4.2 x 10-4

               4.2 x 10-4 to 1.4 x 10-3

               1.4 x 10-3 to 4.2 x 10-3

               4.2 x 10-3 to 1.4 x ID"2

               >1.4 x 10-2
                             Very slow

                             Slow

                             Moderately slow

                             Moderate

                             Moderately rapid

                             Rapid

                             Very rapid
                                FIGURE 4-4

                      SOIL PERMEABILITIES AND  SORPTIVE
                        PROPERTIES  OF SELECTED SOILS
                INCREASING
                SORPTION
                CAPACITY
             PERMEABILITY
                        10    10    10   10   10    10   10   10    I    10
           TYPICAL SOIL TYPES
                                              I SANDS, SANDY GRAVELS
               I SILTS, SLTY SANDS,
                SILTY SANDY GRAVELS
I CLEAN I
6RAVELS
                                       4-6

-------
The  climate  also  influences the soil  requirements of a specific  site.   In
an area  with high rainfalls, for  example,  soils with permeabilities that
are  lower than the  sludge permeabilities  could result  in the  so-called
"bathtub"  effect:   a  situation  in which water  accumulates in the  trench
areas  and cannot  drain.    If  impermeable soils  are  to be  used  in  these
areas, it  may  be  necessary to install  leachate collection  systems.
The  pH  and  cation exchange capacity  (CEC)  influence the ability of  soils
to  attenuate cations  [3],   Heavy  metals  are  frequently  held  by alkali
soils.   The CEC  is  determined to a  large  extent by  the  clay content  of
the  soil  but   it  increases  in  direct  proportion  to  the  pH  dependent
charged  particles (hydrous metal oxides  and  organic matter)  in the  soil.
Table 4-2  shows typical  ranges for CEC  values  in  various  soils.    Soils
with  higher CEC  values  are more  efficient  at  removing cations  and  are
therefore  desirable at  a sludge landfill  site.  Other significant  con-
siderations  concerning  soils   are  compaction characteristics,  drainage,
and  slope stability.   These are summarized  in Figure 4-5.
                                  TABLE 4-2

                     TYPICAL RANGES OF CATION EXCHANGE
                  CAPACITY OF VARIOUS TYPES OF SOILS [3]
                                              Range of CEC,
                         Soil type	meg/100 g
                   Sandy soils                      1 to 10

                   Silt loams                       12 to 20

                   Clay and organic soils                Over 20
The structural and  mineralogical  characteristics of the aquifer should be
delineated  so that  the  potential  for  contamination  can  be  accurately
assessed.   Faults,  major  fractures,  and joint  sets  should  be identified
for candidate  sites.   Where these features  are  in  hydraulic contact with
an aquifer,  contamination  could  occur.    Karst  terrains  and  other solu-
tional  formations  should  be  avoided.   In  general,  limestone,  dolomite,
                                    4-7

-------
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FIGURE 4-5
UNIFIED SOIL CLASSIFICATION SYSTEM AND CHARACTERISTICS
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-------
and heavily  fractured crystalline  rock  are less desirable  than sedimen-
tary and consolidated  alluvial  bedrock.


     4.2.5  Groundwater
Groundwater  can  generally be  classified  into two components.   The first
is that groundwater  located  within the zone of saturation.  The second  is
known as  interstitial  water and includes  groundwater  located  in the zone
of aeration.   For the  purposes of  this  section, discussions  of ground-
water are directed toward  water within the zone of saturation.
In assessing the  suitability of a site for sludge landfill ing, collection
and evaluation  of data on  local  aquifers is essential.   The information
should  include  depth  to  groundwater  (including   historical  highs  and
lows),  the  hydraulic gradient,  the  quality of the  groundwater,  its cur-
rent  and projected   use,  and  the  location  of  primary  recharge  zones.
Figure  4-6, a  schematic  representation  of the hydrogeological  cycle,
illustrates these  principles.
                                 FIGURE 4-6


                         HYDROGEOLOGICAL CYCLE [4]


                         PRECIPITATION
                                                     SURFACE
                                                     '  RUNOFF
                                                             DISCHARGE
                                                              AREA
ZONE
 OF
ARBATJON
         till
                SUBSURFACE MOVEMENT
                       LIMESTONE SOLUTION WIDENED JOINTS
                               CTmiii—I—r
        PERMEABLE  SANDSTONE
                               AQUICLUDE
                                    4-9

-------
Sludge should not be placed where there is a potential for direct contact
with  the  groundwater   table.    Also,  major  recharge  zones   should  be
eliminated  from consideration,  particularly sole  source aquifers.   As
much distance as possible  should  be  maintained  between the bottom of the
fill and the highest known level of groundwater.
Sources  of data  on  groundwater  quality  and movement  include  the U.S
Geological Survey (USGS) "Groundwater Data Network", local well drillers,
State   geological   surveys,  State   health   departments,   other   State
environmental  and  regulatory agencies,  and samplings  from  nearby wells.
The USGS  also publishes  an  annual  report entitled "Groundwater Levels in
the United States"  in  the  Water-Supply  Paper Series.   The  data for this
paper  is  derived from  some 3,500  observation  wells  located  across the
nation.
If  necessary,  further  background information  on groundwater  should be
collected by  performing on-site drilling.   The  following  information is
relevant to evaluating  a site:
    1.  Groundwater elevations and fluctuations
    2.  Hydraulic gradient
    3.  Groundwater quality


The  hydraulic gradient  is equivalent  to the  slope of  the groundwater
table (or the  slope of  the piezometric surface for an artesian aquifer).
Determining  the  hydraulic  gradient  of the  site is  important  in  ascer*-
taining the  rate and  amount  of  groundwater  movement and  whether or  not
hydraulic connections  to  surrounding  aquifers  exist.  The  direction  of
groundwater  flow (and  thus the hydraulic  gradient)  can  be determined  by
noting  the  depth to groundwater  in  nearby wells or borings, calculating
the elevation  of the  groundwater, and drawing contour lines that  connect
wells of equal groundwater elevations.


At  least  three  wells—and normally  more—are  needed  to  determine  the
direction of groundwater flow.   Usually  large  sites, sites with  complex
hydrogeology,  and/or  relatively  flat  sites require  more  borings  than
small  sites.  An  experienced hydrogeologist  should participate  in  the
research  and  exploratory  drilling  to  interpret  field   data.    He  can
recommend  the number,  location,  and  type of exploratory wells  needed.
Table 4-3 summarizes  log  tests and the  information  available from  them.
     4.2.6  Vegetation
The  amount  and type of  vegetation  on a  prospective  site  should be  con-
sidered  in the  selection  process.   Vegetation  can  serve  as a  buffer  and
                                    4-10

-------
                                          TABLE 4-3

                           SUBSURFACE  LOGGING  INFORMAflON
                           OBTAINED BY VARIOUS  METHODS  [3]
                 Method
               Drillers' log




               Drilling-time log

               Resistivity log
                                    Operation
                                                        Information
               Potential  log



               Temperature log

               Cal(per log


               Current log


               Radioactive log
Observe well cuttings
during drill ing
Rock contacts, thickness,
description, or type texture.
Samples for laboratory tests.
Common method.
Observe drilling time    Rock texture, porosity.
Measure electrical
resistivity of media
surrounding encased
hole
Measure natural
electric potential,  or
self-potential

Measure temperature

Measure hole diameter


Measure current
Measure attenuation of
gamma and neutron rays
Specific resistivity of rocks
porosity, packing, water
resistivity, moisture content,
temperture, groundwater
quality.  Correlate with
samples for best results.
Common method.

Permeable or impermeable,
groundwater quality.  Common
method.

Groundwater circulation, leakage.

Hole diameter, rock consolidation,
cavimj zones, casing location.

Groundwater flow velocity, circu-
lation, leakage.

Consolidation, porosity, moisture
content.  Common in soil studies,
clay or nonclay materials.
reduce   dust,  noise,  odor   and   visibility.     However,  where   extensive
logging and/or clearing  of vegetation  is  necessary,  it  can  increase  costs
prohibitively.
      4.2.7   Site  Access
The haul  routes to the prospective sites  should  utilize  major  highways  to
the  maximum  extent   possible.     Potential   routes   should  be  driven   and
studied to  determine  the  physical  adequacy of roadways for truck traffic;
the  approximate  number  of  residences,   parks,  and   schools   fronting   the
roads;  and  the  probable  impact  on  traffic  congestion.
                                             4-11

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     4.2.8  Land Use
The zoning  of  each prospective  site  should be considered  from the  per-
spective of both current and future standards.  The appropriate county  or
municipal zoning authority should be contacted to determine zoning  status
or restrictions as they pertain  to  each  site.   Completed site use  of the
sludge landfill  should  be  considered early  in  the  selection  process and
evaluated relative to future zoning (see Chapter 8, Completed Site).
Regional  development  should  also  be considered  in site  selection,  and
existing master  plans  for the area  should  be  consulted.   The evaluation
of current and future  development  may present  the opportunity for a more
strategically centralized location of the sludge  landfill.  Moreover,  the
projected  rate  of  industrial  and/or  municipal  development  and   its
location  affect  the site size which  will  be  needed  to  meet  projected
demands.
     4.2.9  Archaeological or Historical Significance
The  archaeological  or historical  significance of  the  land involved  in  a
potential site  should  be  ascertained.   The determination  of the  histori-
cal  status  of  a potential site is  usually addressed in an environmental
impact  report   and  should  be  performed   by  a  qualified  archaeologist/
anthropologist.   Due  to  the  expense  involved  in  such studies,  archae-
ological  and  historical  investigations  should  be limited  to  the  top
ranking  candidates.    Any  finds   of  significance  in  relation  to  the
archaeology  or  history of the site must  be accommodated  before  the  site
can  be approved and construction can begin.
     4.2.10  Environmentally  Sensitive  Areas


The Classification  Criteria  for Solid  Waste  Disposal  Facilities [1]  now
being promulgated  by EPA identify  five environmentally sensitive  areas.
These include:
    1.  Wetlands
    2.  Flood  plains
    3.  Permafrost  areas
    4.  Critical  habitats  of  endangered  species
    5.  Recharge  zones  of  sole  source  aquifers
                                    4-12

-------
In general,  sludge landfills  should not  be located  in environmentally
sensitive areas when feasible alternatives exist  since both  the  technical
and administrative  measures  required will  probably  be more  complex.   In
addition, permits  may  be required  for  sludge landfill ing  in  such  areas
(including wetlands and critical habitats).


     4.2.11  Costs
Early in the  selection  process  an economic  screening  of  sites should  be
performed to  determine  relative costs.  In  order  to obtain a meaningful
figure that  can  be  used  to compare  sites,  capital  and  operating  costs
should be estimated.  This  estimate may be computed  as  shown below.   This
discussion does not  account for the time value of money.  For  most sites,
particularly  long-lived  sites,  this  will  tend to  favor the selection  of
sites with high capital costs over sites with relatively higher operating
costs.  In some cases,  it may be  necessary  to  compute amortized capital
costs.  However, the  process described below is  less complex  and will  be
accurate in the vast majority of cases.


     1.  Determine the capital  costs  (C)  in  dollars over  the  life of the
         site.  This should include primarily:

         a.  Land aquisition
         b.  Site preparation
         c.  Equipment purchase

     2.  Determine site life (L) in years.

     3.  Compute  unit  capital  cost   (P-|)   in   dollars/yd^  of  sludge
         based on proposed  annual  sludge quantity (Q)  in yd-Vyr.

                                   r
                            P. =
                             1      LQ


         Determine total  operating cost  (0)  in  dollars  over  one year.

         This should include primarily:

         a.  Labor
         b.  Equipment fuel, maintenance, and parts
         c.  Utilities
         d.  Laboratory analysis of water samples
         e.  Supplies and materials
         f.  Miscellaneous and other
                                    4-13

-------
     5.  Compute  unit  operating  cost   (P£)   in  dollars/yd3  of  sludge
         based on proposed annual sludge quantity (Q) in yd /yr.
                              P
                              P2
     6.  Determine total hauling cost (H) in dollars over one year.

     7.  Compute  unit  haul  cost  (Pg)   in  dollars/yd   of  sludge  based
         on proposed  annual sludge quantity (Q) in yd3/yr.


                              p   =   H
                               3      Q
                                                    o
     8.  Compute total annual cost  (T)  in dollars/yd  of sludge,

                         T = P, + Po +  P,
                              j.     C-    O


4.3  Site Selection Methodology


A site selection process may consist of the following stages:
    1.  Initial assessment of sites
    2.  Screening of candidate sites
    3.  Final  site selection
Sections 4.3.1,  4.3.2,  and 4.3.3 outline  a  selection procedure that  has
been  used.   This procedure is  summarized  in Figure  4-7.   Smaller  sites
may  not  require  a  selection  process  as  detailed  as the  one  presented
below.
     4.3.1   Initial Assessment of  Sites
Step 1-1:  Determine regulatory constraints  (Federal, State,  local)  based
           on:


         1.  Physical limitations  (groundwater  depth, maximum  slope)

         2.  Demographical  limitations  (distance  to  nearest  residence,
            land-use factors)

         3.  Political   limitations   (public  reaction,   special   interest
            groups, budget management)

                                    4-14

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                       4-15

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Step 1-2:  Establish suitable study areas:
        1.  Determine  maximum  radius  of   study   area   based   on  haul
            distance(s)   from  wastewater   treatment   plant(s)   and/or
            centroid of potential  service area.

        2.  Use  transparent   (mylar)  overlays  to  designate  areas  which
            have:

             a. inappropriate slope
             b. dense population
             c. undesirable geology (karst, fractured bedrock
                formations, faults)
             d. undesirable   soil   (shallow,  high  organics,  permafrost
                areas)
             e. unsuitable  surface   or   groundwater  conditions  (flood
                plains, bogs,  areas  of ponding, marshes,  recharge zones
                of aquifers)

         3.  Place shaded mylars of these  low  suitability areas  on study
             area  map.   The  unshaded area  may  be  considered  generally
             suitable for landfill ing.
Step 1-3:  Identify potential candidate sites:


        1.  Inform local realtors

        2.  Investigate past site inventories

        3.  Study maps or aerial photographs

        4.  Traverse  roads  in  high  probability  areas  for  "For  Sale" or
            "For Lease" signs


Step  1-4:  Assess  economic  feasibility  (ballpark  estimate  based  on
           experience, rule  of thumb, judgement) including:


        1.  Haul distances

        2.  Rough estimate of site development cost

        3.  Quantity  of siudge

        4.  Operating hours  per week for equipment and personnel
                                    4-16

-------
Step   1-5:   Perform   preliminary  site   investigations   using  existing
           information  (see  Chapter  5,  Design)  and tabulate  information.
           Pertinent information includes:
        1.  Location (drainage basin)

        2.  Land use(on and near site)

        3.  Haul distance and routes

        4.  Topography

        5.  Soil characteristics

        6.  Area of site
Step  1-6:  Eliminate  less  desirable  sites  based  on  regulatory  and
           economic constraints and technical considerations.
Step 1-7:  Obtain public  input  via  the public participation program  (see
           Chapter 2).    For  example,  a  kick-off  meeting  would  help to
           determine the  attitude of the  citizenry early in the process.
           Area  residents  also  may  assist  in  identifying  candidate
           sites.
     4.3.2  Screening of Candidate Sites


Step 2-1:  Determine methodology  for screening candidate  sites  in terms
           of the  considerations  listed  below.  Designate  the  degree of
           detail required to fulfill regulatory requirements.  Designate
           a screening committee of qualified personnel.  The methodology
           may include scoring systems and other subjective analyses [5],
           Again,  the  evaluation  presented  below  may be  more  extensive
           than necessary for small  sludge landfills.


        1.  Technical considerations

           a. haul  distance
           b. site  life and size
           c. topography
           d. surface water
           e. soils and geology
           f. groundwater
           g. soil  quantity and suitability
           h. vegetation
                                   4-17

-------
           i. environmentally sensitive areas
           j. archaeological or historical significance
           k,. site access
           1. land use

        2.  Economic considerations

        3.  Public acceptance considerations


Step 2-2:  Investigate 4 to 6 candidate  sites and identify site specific
           problems.  Field investigations (see Chapter 5, Design) may be
           appropriate to  supplement  information  from  existing sources.
           However, the  degree  of detail  and  intensity of investigation
           will  vary from site to site.


Step 2-3:  Evaluate sites.   The sites may  be evaluated  in terms  of the
           potential adverse impact on the environment.  A scoring system
           similar to the  one  described  in Section 4.4 may  be useful in
           quantitatively evaluating the candidate sites.
Step 2-4:  Rate sites.  The rating is based on technical considerations.


Step  2-5:  Input  site   selection   findings   of  top  site(s)  into  an
           environmental  impact report  (if required).


Step 2-6:  Obtain public  input.


     4.3.3  Final Site Selection


Step  3-1:   Prior to  final  site  selection,   the  landfill ing  method  and
           preliminary design should be ascertained for each site.   These
           designs should be compatible with  sludge and site characteris-
           tics  (see Section  3.6).    Preliminary drawings  are prepared
           in this phase.
Step 3-2:  Evaluate alternative completed  site uses and determine  use  for
           each candidate site.
                                    4-18

-------
Step 3-3:  Evaluate economics in detail


         1 .  Site capital cost

         2.  Site operating cost

         3.  Haul ing cost


Step 3-4:  Evaluate local government policies and obtain public input.  A
           public hearing may be scheduled to receive final comments from
           local government officials  and the public.


Step 3-5:  Select site and list alternative sites.


Step 3-6:  Acquire site.  The following options are available:


        1.  Option  to  purchase  and   subsequent  execution   (await  site
            approval )

        2.  Outright  purchase  (after  site approval  by  regulatory agency
            and local jurisdiction)

        3.  Lease

        4.  Condemnation and/or other  court action

        5.  Land dedication


4.4  Example of Methodology
This section  presents  an example  of  a methodology used  for  selecting a
landfill site.  This example  includes initial  assessment, screening, and
final  selection  procedures.    The  procedures  in this  example  employ
numerical  scoring  systems.    However,  in  some  cases  it  may be  more
appropriate  to use  a  qualitative  system  (e.g.,  using  terms such  as
suitable,  marginally  suitable,   not   suitable   in   lieu  of  numerical
ratings).   In this  example,  the  study  area  was  a  large county  in the
mid-Atlantic region.
                                   4-19

-------
     4.4.1   Initial  Assessment of Sites
The  initial  step was  to use  overlays to  narrow the  study area  to  that
portion  of  the county  where  technically  suitable sites were  most likely
to be found.
    1.  Overlay  No.  1.    Shaded  areas  having  questionable  soils.   The
        soils  were evaluated  in  terms  of  soil   permeability and  runoff
        characteristics.   The  SCS  District Manager  and the  Cooperative
        Extension  Service were sources for  this  information.

    2.  Overlay  No. 2.   Shaded  areas containing possible  topographical
        limitations.   These included  flood plains  and a small  watershed
        which  drained  to  a vital drinking water  supply.

    3.  Overlay  No. 3.  Shaded  areas  having questionable geology.   State
        geologists were consulted  to  determine  areas  where  shallow soil
        which  covers  fractured bedrock existed.
The overlays  were placed  over a county  map and  the unshaded  areas  were
considered  generally suitable for sludge landfill ing (see Figure 4-8).
                               FIGURE 4-8

                     INITIAL ASSESSMENT WITH OVERLAYS
               LEGEND

            UNSUITABLE SOILS

            TOPOGRAPHIC LIMITATIONS

            UNSUITABLE GEOLOGY

        S-l •  CANDIDATE SITE
                                     4-20

-------
After  identifying  all  feasible  sites (13  in  this case),  a preliminary
investigation  of  technical  data  was  performed.    The  results  were
tabulated in Table 4-4.  Based  on  the information compiled in Table 4-4,
these  13  sites  were then  evaluated  relative  to  the criteria  listed  in
Step 1-5 of Section 4.3.1.  Based on  this evaluation, 9 of the sites were
eliminated  from futher  considerations.    The  4  remaining  sites  were
identified as S-5,  S-10, S-ll, and S-13.
     4.4.2  Screening of Candidate Sites

The screening process began with the collection of more detailed informa-
tion on  the  remaining 4 sites.  This  data  is compiled in  Table  4-5.   A
scoring system was then applied as shown in Table 4-6 using the following
considerations.
    1.  Principal objectives  of sludge landfills.   The  etablishment and
        use of the site was  based  on  certain objective.   Objectives were
        developed  so  that  they  were  attainable,   and  the  degree  of
        attainment was measurable.  The scoring system employed contained
        five principal objectives.

    2.  Rating of objectives by order of importance.  The objectives were
        listed in order of importance, and a value  was  assigned  to each
        objective to reflect  its  relative  importance.    Once this  was
        accomplished,  experience  showed  that  many of  the  originally
        listed  objectives  appeared  insignificant  and  were  therefore
        discarded.

    3.  Criteria.  Having  listed the  objectives,  criteria  which measured
        the  ability  of  a  site  to  attain  that  objective  was  then
        developed.

    4.  Relative ability of  criteria  to  fulfill  objective.   The criteria
        for  each objective   then  was   assigned  numerical  values  that
        reflected their  relative  ability to  measure most  exactly  the
        attainment   of  the   objective,   rather   than  their  individual
        significance.

    5.  Maximum  score.   Based  on  values  in  columns (2)  and (4),  the
        maximum score was  calculated for each criterion.  For example the
        objective of  public  health  has a rating  of  1,000.   The criteria
        of a groundwater pollution hazard  rates  10  out of a  total  of 34
        total   points  for   all  public   health   criteria.     Therefore,
        (10/34)x(l,000) =  a maximum score of 244 points

    6.  Prospective  landfill  sites.   All  sites  were  compared relative to
        one  criterionByassigning   a  numerical   value  (rating)  that
        reflected the site's  ability  to  satisfy   the  criterion  being
        examined.    (If  a  site could not    meet   the  objective  being
                                    4-21

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         examined,  it was  eliminated from  further consideration).   Various
         specialists  scored the  sites  under  criteria  involving  their  area
         of  expertise.    For  example,  planners  were  used  to  score  those
         criteria related  to land  use.
The  scoring  was  found to  be more effective  when  all  sites were  evaluated
relative  to  one  criterion  before   other  criteria were  examined.    Each
criterion  was  given  a   score  ranging  from  1  to  10,   the  higher   score
represented  the  desirable  direction.    Thus,  a  site  with  no  "potential
groundwater  pollution hazard", for  instance, received  a score  of 10.   The
rating was  then  assigned a  pro-rated score.   For  example, the  potential
groundwater   pollution  hazard  rating  for   S-5  was   7;  therefore,   the
pro-rated score =  (7/34)x(1,000)  =  206
      4.4.3   Final  Site Selection
Following  the scoring system, an  economic  evaluation  of the top sites  was
performed  and  documented  in  Tables  4-7  and  4-8.    The  total  cost  was
calculated   using  the  following   formulas   to  determine  pro-rated  cost
(S/yd-3)  over  the   life  of   the  site  based   on  the   projected  sludge
volumes.
                                    TABLE 4-7

                           OPERATING  COST  ESTIMATES
                                                     Site no.
              Description	S-5	S-10     S-11    S-13

              One Full-Time Equipment Operator
                Cost Includes an Allowance of
                30% for Fringe Benefits       $ 15,000   $ 15,000  $ 15,000  $ 15,000

              Equipment Operation and
                Maintenance                 15,000    15,000   15,000   15,000

              Site Operation and Maintenance     5,000     5,000    3,000    4,000

              Leachate Haul Costs            1,000      —     1,000

              Cover Material Purchase          25,000      —    40,000

              Temporary Road Surfacing,
                Access and Highway Cleaning     20,000    15,000   15,000    8,000

              Groundwater Monitoring Samples     3,000     2.000    2,000    2.000

              Subtotal of Site Costs        $ 84,000   $ 52,000  $ 91,000  $ 44,000

              Sludge Hauling Cost            15.000   150,000   25,000   75,000

              Total Operating Cost/yr         $99,000   $202,000  $116,000  $119,000

              Unit Cost ($/yd3) based
                on 18,000 yd3/yr             $5.50    $11.22    $6.44    $6.61
              1 yd3 = 0.7646 m3
                                        4-26

-------
                                        TABLE  4-8
                               CAPITAL COST  ESTIMATES
               Description
                                                         Site no.
                                            S-i.
Land Acquisition
  Number of Acres                 20
  Cost per Acre                 3,300
  Purchase Price               66,000

Site Development Costs
  Initial Site Preparation       50,000
  Clearing and Grubbing          120,000
  Fence and Gate               10,000
  Access Roadway (On-Site)        8,000
  Leachate Collection System      20,000
  Storm Water Managanent         15,000
  Reconstruct Primary Access
   Roadway
  Equipment Storage Shed
  Utl 1 Hies
  Mom toriruj

Subtotal
Engineering Surveying
  Subsurface Exploration
  and  Penmts (2051)
Contingency (10%) of Land        31,000
  Acquisition and Site
  Development Costs
Equipment
  Backhoe Loader
Total  Capital  Cost
Estimated Site Life (yrs)
Unit Cost ($/yd3) based on
  18,000 yd3/yr                2.30
                                                   30,000
                                                    2,000
                                                   12,000
                                                   16,000

                                                   20,000
30,000
 3,000
10,000
 3,000
25,000
15,000
                                                   2.76
                                                                   S-13
                                                      37       25      30
                                                    8,000    2,000    8,300
                                                  296,000   500,006  249,000
                                           15,000    15,000
                                           2,000     3,000
                                           4,000     4.000

                                          310,800   398,000   157,000  461,000
                                           62,000    79,600   31,400   92,200
                                                   39,800   15,700   46,100
                                                   80,000   120,000   30,000
                                                  597,400   324,100  674,300
                                                    12      10       12
                                                                  3.12
               1  yd-*
                     0.7646
               1  ac <=  0.4047 ha
A  compilation  of data  impacting  on  the  final   site  selection  was  then
assembled  in Table  4-9.    As  shown,  the  technical  prioritization  of  the
sites  was  S-ll,   S-13,  S-5,  and  lastly  S-10;  the  cost  prioritization  was
S-5,   S-ll ,  S-13,  and  S-10;  and  the  public  acceptance  prioritization  was
S-13,  S-5,  S-ll,  and  S-10.    In  this  example,  Site  S-13 was  selected  on
the  basis of its  (1)  top public  acceptance  ranking,  (2)  longer  life,  and
(3)   completed  site  use  as  a   needed   park.    Although   S-13  was   not  the
top-ranked  site   technically,  it  was determined to  be  acceptable.   Also,
the  cost  of S-13  was  relatively  high;  however, the  operating  agency  was
forced  to absorb these costs due  to the obvious site  benefits.
                                           4-27

-------
                                 TABLE 4-9

                          FINAL  SITE SELECTION
Map
ref.
S-5
S-10
s-n
S-13
Site name/
location
Alton Street
Site
Hunter Road
Site
Harringon
Blvd. Site
Gilford
Road Site
Scoring
system
value
1,773
1,538
2,534
2.230
Landfill ing
' method
Area fill
mound
Wide trench
Area fill
mound
Wide trench
Proposed
final site
use
Open space
Return to
natural state
Pasture
Park
Site
life
10 yrs
12 yrs
10 yrs
12 yrs
Total annual
cost
($/yd3)a
7.80
13.98
8.24
9.73
Public
acceptance
ranking
3
2
4
1
a Sum of capital and operating costs

° Provided from attitude survey taken at public meetings.
 Lower numbers represent less opposition

1 yd3 = 0.7646 m3
4.5  References

1.   Proposed Classification  Criteria  for Solid Waste Disposal  Facilities.
     U.S.  Environmental Protection Agency. Federal  Register.   February  6,
     1978.

2.   Weaver,  D.E.,  C.J.   Schmidt,  and  J.P.  Woodyard.    Data  Base  for
     Standards/Regulations  Development   for  Land   Disposal   of  Flue  Gas
     Cleaning Sludges.  U.S.  Environmental Protection Agency,  Cincinnati,
     OH.   Report No. EPA-600/7-77-118.  December 1977.  pp.  146-148.

3.   Process  Design Manual  for  Land  Treatment  of  Municipal  Wastewater.
     U.S.  Environmental  Protection Agency.   Technology  Transfer.   Report
     No.  EPA-625/1-77-008.  October 1977.  pp. C-13-C-19.

4.   Brunner,  D.R.  and Keller,  D.J.   Sanitary Landfill  Design and  Opera-
     tion.   U.S.  Environmental Protection  Agency.  Washington,  DC.   Report
     No.  SW65ts.   1972.   pp.  17.

5.   Sexsmith,  D.P.   et  al.   Selection  Criteria,  Methods,  and  Scoring
     System  for Sanitary Landfill  Site Selection.   J_n:    Proceedings  of
     Canadian  Conference  on Solid Waste.  1976.  pp.  301-317.
                                     4-28

-------
                                CHAPTER 5

                                 DESIGN


5.1  Purpose and Scope


The  objective  of  a  sludge landfill  design is  to  direct  and  guide the
construction  and  on-going  operation  of the  landfill.    A  design  should
ensure  (1)  compliance with  pertinent regulatory requirements,  (2)  ade-
quate  protection  of  the environment, and  (3)  cost-efficient utilization
of site manpower,  equipment,  storage  volume,  and soil.   A  design  package
(consisting  of all  design documents)  should  be  prepared   to  provide  a
record of the  landfill  design.   These may  consist  of drawings, specifi-
cations, and reports.


The  purpose  of this  chapter  is to provide  guidance  on  the  design of  a
sludge landfill.  Specific topics addressed include:


     1.  Typical   permitting   procedures   and   regulatory    requirements
         (Section 5.2)

     2.  Design methodology (Section 5.3)

     3.  Relevant data and sources of information (Section  5.3)

     4.  Contents of the design package (Section 5.3)

     5.  Information on specific landfill ing method designs  (Sections 5.4
         through 5.6)

     6.  Information on other designs (Sections 5.7 through  5.16)


5.2  Regulations and Permits


Many regulatory  and  approving  agencies  require  permits  before  a  sludge
landfill can be constructed  or  operated.  The sludge landfill  design is
generally an  integral  part  of  the  application  for  such  permits.   Ac-
cordingly, all  pertinent agencies should be contacted early  in the  design
phase  to  (1)   identify  regulations  impacting  on the  prospective  sludge
landfill, (2)  determine the  extent,  detail,  and format  of the applica-
tion, and (3) obtain any permit application forms.  Once  this information
has  been  collected,  the design  can  proceed in  a more  efficient   manner
toward the goal of receiving the necessary permits.
                                    5-1

-------
Requirements and permits  relevant  to  sludge landfills are found to exist
on  the  State,  and  local  levels.    One program  of  concern  is  the   EPA
Construction Grants Program  administered by the  Office  of Water Program
Operations.  Grants can  be  received  from this source  to  cover  up to 75%
of the capital  costs (including land acquisition, equipment purchase,  and
site  preparation)  for  the entire  sludge management  system.   Since this
system  includes  both  in-plant  sludge  treatment facilities  as  well  as
disposal  facilities,  the  application  must  address  the  sludge landfill
operation  as  well.   Accordingly,  it  is   important  to  proceed with a
landfill  design  which  is  in accordance with  EPA  grant  requirements  if
grants  are desired.    Other  Federal   requirements  relevant   to  sludge
landfills  are contained  in  the Criteria for  the Classification of Solid
Waste Disposal  Facilities  [1],    These Criteria  address  the   following
topic areas:
     1.  Environmentally sensitive areas
     2.  Surface water
     3.  Groundwater
     4.  Air
     5.  Application on land used for the production of food chain crops
     6.  Disease vectors
     7.  Safety


Environmentally  sensitive  areas  are more specifically  identified as  (1)
wetlands, (2)  flood  plains, (3) permafrost  areas,  (4)  critical  habitats
of endangered  species,  and (5)  recharge  zones  for  sole source  aquifers.
As stated in  the Criteria, disposal facilities  should  not be  located  in
environmentally  sensitive  areas  when  feasible alternatives exist, unless
it can be clearly  demonstrated that there  will  be  no significant impact
on the ecosystem or human  health from the operation of  a facility in  such
an area [1],


Safety concerns  are more  specifically  identified as (1) explosive gases,
(2) toxic or asphyxiating  gases, (3) fires,  (4)  bird hazards to aircraft,
and  (5)  access.   As  stated  in the Criteria,  disposal  facilities should
not pose a safety hazard to facility employees,  users,  or  the  public  with
respect to any of the above features.  Requirements also exist  in each  of
the  remaining  topic  areas and  the  Criteria should  be consulted  for  a
complete  description.   Many  of the  requirements  in  the  Criteria  are
already addressed in  State  regulations.   Table 5-1 provides  an  analysis
of the Criteria  topic areas included in State regulations.


Several permits  relevant  to  sludge  landfills are identified and  mandated
by these Criteria.  Generally  these include:
                                    5-2

-------
     1.  NPDES  permit  required  for  location  of  a  sludge  landfill   in
                     It  is also required  for  any point source discharges
wetlands.
at sludge
                   landfill s.
     2.  Army Corps  of  Engineers  permit  required for the construction
         any  levee,  dike, or  other  type of containment  structure to
         placed  in the  water at a sludge landfill located in wetlands.
                                                              of
                                                              be
     3.  Office  of Endangered Species  permit may
         Fish  and"Wildl ife  Service,  Department
         location  of a sludge landfill  in critical
         species.
                                           be required  from the
                                           of the   Interior  for
                                           habitats  of endangered
State  and  local  regulations  and  permits  are  highly  variable  from
jurisdiction to jurisdiction.  Depending on the jurisdiction, one or more
permits may  be  required for a sludge  landfill.   Typical  permits  on the
State and local  levels  include:
     1.  Solid waste management permit
     2.  Special use permit
     3.  Zone change certification  for a change  to  a zoning appropriate
         for a sludge landfill
     4.  Sedimentation  control  permit  for   surface   runoff  into  water
         courses
     5.  Highway  department  permit  for  entrances  on  public  roads  and
         increased traffic  volumes
     6.  Construction permit  for landfill site preparation
     7.  Operation permit for on-going landfill operation
     8.  Mining permit for  excavations
     9.  Fugitive dust permit
    10.  Business permit for  charging fees
    11.  Closure permit
    12.  Building permit to construct buildings on the landfill  site
Depending on  local  procedures, permits  may be required  from  both state
and local regulatory  agencies.  State regulatory  agencies  which require
such submittal s may include:
     1.  Solid waste management agencies
     2.  Water quality control agencies
     3.  Health departments
     4.  Building departments
                                    5-3

-------
                                    TABLE  5-1



          ANALYSIS OF  FEDERAL CRITERIA VS.  STATE REGULATIONS  [2]









State
Alabama
Alaska
Ari zona
Arkansas
Cal ifornia
Colorado
Connecticut
Delaware
Florida
Georgia
Hawai i
Idaho
[1 1 inois
I nd i a na
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryl and
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hamsphire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Okl ahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Total
% of Total
Environmentally Sensitive Areas




V>


Z
3




X


X

X








X
X
X

X





X
X
















X

X

11/50
22%


c:

r-


?
o
£



X
X
X
X

X

X



X

X


X
X

X
X
X
X
X

X



X



X
X


X
X
X



X



23/50
45%




o
I-

E
11

X
















































1/50
2%




f_ ^

O T3
t^ .0
(-> 31




X













































1/50
2%


11

t-


l t-
"o cr

O)

OJ
s
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
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
50/50
100%
Safety
11
V)
m

tu

l/l
o
ex
X
LJ




X

X
X
X




X





X


X

X



X
X








X



X



X



14/50
28%







V
t-
u.
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
X

X
X
X
X

X
X

X
X
41/50
82%


l/l
Ol

o

"
0




X

X

X




X





X


X

X



X
X








X



X



X



13/50
26%


•a

n3


•£
CL3




X



X













X






X












X







5/50
10%






V>
OJ
u


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
X
X
X
X
X
X

X

X

X
X
42/50
84%








% of
Total3
50%
60%
50%
70%
100%
60%
70%
60%
100%
70%
40%
60%
60%
80%
60%
40%
70%
20%
50%
90%
60%
70%
100%
50%
90%
60%
70%
60%
90%
90%
50%
50%
70%
30%
50%
50%
70%
70%
80%
50%
70%
70%
100%
40%
40%
50%
90%
40%
90%
60%


Environmentally sensitive areas counted as one criterion for row totals.
                                          5-4

-------
Local  regulatory  agencies  may  include:
      1.  Health  departments
      2.  Planning  and/or  zoning  commissions
      3.  Board of  county  commissioners
In  many jurisdictions more than  one  of the State  or local agencies  has
authority over  a  disposal  site.  Also, in some jurisdictions,  one  agency
has  control  over sludge-only landfills while  another agency has control
over refuse  landfills.
The  reviewing  agency may  require the  submittal  of  information  on  standard
forms  or  in  a  prescribed  format  in  order  to  facilitate  the  review
process.   In any event,  applicants  are  responsible for the completeness
and  accuracy  of the  application   package.    The  completed  application
package  is  then  reviewed  by  the   regulatory  agency.   The time of  the
review  period will  vary  depending  upon  the  regulatory  agency,   their
attention  to  detail, the  number of applications preceding it, etc.   From
experience,  this  process  has been  found to  take  at  least  one month  and
usually 6  to 12  months or  longer.   After  a permit  is  issued, it can  be
valid  for  various  durations,   depending  largely  upon  the  submittal  of
inspection/  performance reports and the outcome  of on-site  inspections.


5.3  Design  Methodology and Data Compilation
Adherence  to a  carefully planned  sequence of  activities to  develop  a
sludge  landfill  design  minimizes project  delays  and  expenditures.    A
checklist  of  design  activities  is  presented   in  Table 5-2.    These
activities are  listed  somewhat in their  order  of performance.  However,
in many cases separate tasks  can  and should be performed  concurrently or
even out of the order shown.
As  shown  in  Table  5-2,  initial  tasks  consist  of  compiling  existing
information and generating new information on sludge and site conditions.
Obviously, some of this  information  would  have already been collected in
the  site  selection   phase.    Generally  however,   additional  and  more
detailed information will have to be collected in the design phase.


Information utilized during both the site selection  and design phases can
be  derived either  from  existing  sources  or new  sources  (i.e.,  field
investigation).   A  listing  of possible existing  information  sources has
been  included  as  Table  5-3.    A  listing  of  possible new  information
sources has been  included in Table 5-4.
                                   5-5

-------
                                         TABLE  5-2

                      SLUDGE  LANDFILL   DESIGN  CHECKLIST
Step                               Task

 1         Determine  sludge  volumes and characteristics

           a.   Existing
           b.   Projected

 2         Compile existing  and generate new site information.

          a.   Perform  boundary and topographic survey
          b.   Prepare  base  map of existing conditions on-site  and  near-site

              (1)  Property boundaries
              (2)  Topography and slopes
              (3)  Surface  water
              (4)  Utilities
              (5)  Roads
              (6)  Structures
              (7)  Land use

          c.   Compile  hydrogeological  information and prepare  location map

              (1)  Soils  (depth, texture, structure,  bulk  density,  porosity, permeability,
                   moisture, ease of excavation, stability,  pH,  and cation exchange
                   capacity)
              (2)  Bedrock  (depth, type, presence of fractures,  location of surface
                   outcrops)
              (3)  Groundwater (average depth, seasonal  fluctuations, hydraulic gradient and
                   direction of flow,  rate of flow, quality,  uses)

          d.   Compile  climatological data

              (1)  Precipitation
              (2)  Evaporation
              (3)  Temperature
              (4)  No. of freezing days
              (5)  Wind direction

          e.   Identify regulations (Federal, State, and  local) and  design standards

              (1)  Requirements for  sludge stabilization
              (2)  Sludge loading rates
              (3)  Frequency of cover
              (4)  Distances to residences, roads, and surface water
              (5J  Monitoring
              (6)  Roads
              (7)  Building codes
              (8)  Contents of application for permit

 3        Design filling  area

          a.   Select landfill ing method  based on:

               1)  Sludge characteristics
               2)  Site topography  and slopes
              (3)  Site soils
              (4)  Site bedrock
              (5)  Site groundwater

          b.  Specify design dimensions

              (1)  Trench width
              (2)  Trench depth
              (3)  Trench length
              (4)  Trench spacing
              (5)  Sludge fill depth
              (6)  Interim cover  soil  thickness
              (7)  Final  cover  soil  thickness
                                             5-6

-------
            TABLE  5-2   (Continued)
c.  Specify operational  features

    (1)  Use of bulking  agent
    (2)  Type of bulking agent
    (3)  Bulking ratio
    (4)  Use of cover soil
    (5)  Method of cover application
     6)  Need for imported  soil
     7)  Equipment requirements
    (8)  Personnel requirements

d.  Compute sludge and soil  uses

    (1)  Sludge application  rate
    (2)  Soil   requirements

Design facilities

a.  Leachate controls
b.  Gas controls
c.  Surface water controls
d.  Access roads
e.  Special working areas
f.  Structures
g.  Utilities
h.  Fencing
i.  Lighting
j.  Wasnracks
k.  Monitoring wells
1.  Landscaping

Prepare design package

a.  Develop preliminary  location plan  of fill  areas
b.  Develop landfill  contour plans

    (1)  Excavation plans
    (2)  Completed fill  plans

c.  Compute sludge storage  volume,  soil  requirement  volumes,  and  site  life
d.  Develop final  location  plan  showing:

    (1)  Normal fill  areas
     2)  Special working areas
     3)  Leachate controls
    (4)  Gas controls
    (5)  Surface water controls
    (6)  Access roads
    (7)  Structures
    (8)  Utilities
    (9)  Fencing
    (10) Lighting
    (11) Washracks
    (12) Monitoring wells
    (13) Landscaping

e.  Prepare elevation plans  with cross-sections  of:

    (1)  Excavated fill
    (2)  Completed fill
    (3)  Phased development  of  fill  at  interim points

f.  Prepare construction details

    (1)  Leachate controls
    (2)  Gas control s
    (3)  Surface water controls
     4)  Access roads
     5)  Structures
    (6)  Monitoring wells

g.  Prepare cost estimate
h.  Prepare design report
i.  Submit application and  obtain  required  permits
j.  Prepare operator's manual
                           5-7

-------
                                      TABLE   5-3

                    SOURCES  OF  EXISTING  INFORMATION
General Information
Specific Information
                                                                         Source
Base Map
General
Soils
Bedrock
Groundwater
Topography and Slopes


Land Use


Vegetation



General





General




General
Climatology
                            General
•  County  road  department
•  City,  county,  or  regional planning
   department
t  U.S.  Geological Survey (USGS)
   office  or outlets for USGS map
   sales  (such  as  engineering supply
   stores  and  sporting goods stores)
*  U.S.  Department of Agriculture
   (USDA),  Agricultural Stabilization
   and Conservation  Service (ASCS)
•  Local  office of USGS
•  County  Department of Agriculture,
   Soil  Conservation Service (SCS)
•  Surveyors and  aerial photographers
   in the  area

t  USGS  topographic  maps
t  USDA,  ARS,  SCS  aerial photos

t  City,  county,  or  regional planning
   agency

•  County  agricultural department
»  Agriculture  department at local
   university

•  USDA,  Soil  Conservation Service
   (SCS),  District Managers, Local
   Extension Service
•  USGS  reports
•  Geology or  Agriculture Department
   of local  university

i  USGS  reports
•  State Geological  Survey reports
•  Professional geologists in the area
•  Geology Department of local
   university

•  Water Supply Department
•  USGS  water  supply papers
»  State or regional water quality
   agencies
*  USDA,  SCS
•  State or Federal  water resources
   agencies
•  Local  health department

•  National  Oceanic  and Atmospheric
   Administration (NOAA)
•  Nearby  airports
                                            5-8

-------
        Bedrock
        Groundwater
        Climatology
                                    TABLE  5-4

                   FIELD  INVESTIGATIONS  FOR NEW  INFORMATION
General
Information
Base Map







Soils















Specific Information
Property boundaries
Topography and slopes
Surface water
Utilities
Roads
Structures
Land use
Vegetation
Depth
Texture

Structure
Bulk density

Porosity

Permeabil ity

Moisture
Ease of excavation
Stability

pH
Cation exchange capacity
Method and Equipment
Field survey via transit
Field survey via al idade
Field survey via alidade
Field survey via alidade
Field survey via alidade
Field survey via alidade
Field survey via alidade
Field survey via alidade
Soil boring and compilation of boring log
Soil sampling and testing via sedimentation
methods (e.g., sieves)
Soil sampling and inspection
Soil sampling and testing via gravimetric,
gamma ray detection
Calculation using volume of voids and total
vol ume
Soil sampling and testing via piezometers and
lysimeters
Soil sampling and testing via oven drying
Test excavation with heavy equipment
Test excavation of trench and loading of
sidewall or Hueem stabilometer
Soil sampling and testing via pH meter
Soil sampling and testing
Depth
Type
Fractures
Surface outcrops

Depth
Seasonal fluctuations
Hydraulic gradient

Rate of flow

Quality
Uses

Precipitation
Evaporation
Temperature
No. of freezing days
Wind direction
Boring and compilation of boring log
Sampling and inspection
Field survey via alidade or Brunton
Field survey via alidade or Brunton

Well installation and initial readings
Well installation and year-round readings
Multiple well installation and comparison
 of readings
Calculation based on permeability and
 hydraulK gradient
Groundwater sampling and testing
Field survey via inspection

Rain gauge
Class A Evaporation Pan
Standard thermometer
Minimum-maximum temperature thermometer
Wind arrow
Before  proceeding   to  the  final   design   it   is  advisable  to   recontact
regulatory  agencies who were  contacted during  the site selection  process
and  others  to  try  to  determine  all  of their  requirements  and procedures
for  permit  application  submittals.   This  will  also  provide  an opportunity
to  discuss   design   concepts,  get  questions  answered,  and  determine  any
special or  new requirements.  Maintenance of  close  liaison  with  State and
local   regulatory   officials   throughout  the   design  effort   is   normally
helpful in  securing a permit  without  excessive redesigns.
A  complete  design  package  may  include  plans,  specifications,  a  design
report,  cost   estimate,  and  operator's  manual.    Generally,   the
estimate  and  operator's manual   are prepared  strictly  for
while  plans,   specifications,   and   design  reports   are
regulatory agencies  in  the  permit  application.   Plans  and  specifications
typically  include:
                                                           cost
                                               in-house  uses,
                                                 submitted   to
                                         5-9

-------
     1.  Base map showing existing site conditions.  The map should be of
         sufficient detail, with  contour  intervals of no more  than  5 ft
         (1.5 m) and a scale not to exceed 1 in. = 200 ft (1 cm = 24 m).

     2.  Site preparation  plan locating  sludge  fill  and  soil  stockpile
         areas as well  as  site facilities.   A small-scale  version  of a
         site preparation plan has been included as Figure 5-1.

     3.  Development plan  showing  initial excavated  and  final  completed
         contours in sludge filling areas.

     4.  Elevations   showing   cross-sections   to   illustrate   phased
         development of sludge landfill at several interim points.

     5.  Construction details  illustrating  detailed construction  of site
         facilities.

     6.  Completed  site plan  including   final  site  landscaping,  appur-
         tenances, and other improvements.


A design report typically includes:


     1.  Site description  including existing  site size,  topography  and
         slopes, surface water,  utilities, roads,  structures,  land  use,
         soils, groundwater, bedrock, and climatology.

     2.  Design criteria including sludge types and volumes and fill  area
         design dimensions.

     3.  Operational   procedures   including   site  preparation,   sludge
         unloading,sludge handling,  and  sludge  covering as  well  as
         equipment and  personnel requirements.

     4.  Environmental  safeguards  including control of  leachate, surface
         water, gas, odor, flies, etc.

5.4  Selection of Landfill ing Method


Several  alternative  methods  and sub-methods for  sludge  landfill ing  were
identified  and  described  in  Chapter  3,  Sludge  Characteristics  and
Landfill ing Methods. These include:
     1.  Sludge-only trench

         a. narrow trench
         b. wide trench
                                    5-10

-------
                              FIGURE 5-1


                   TYPICAL  SITE  PREPARATION  PLAN
— T
   LEGEND


 -- EXISTING CONTOURS

	 PROPERTY BOUNDARY

= ROADS


-M- RAILROAD


—  TRANSMISSION LINE

—• STREAM


^  POND


|    DWELLINGS


I    PUBLIC BUILDINGS

    WELL
         WOODS

	DISPOSAL AREA BOUNDARY

   ©    GROUNDWATER MONITORING
           POINT

   (S)    SURFACE  WATER  MONITORING
           POINT

	SURFACE  WATER  DRAINAGE
  	     SYSTEM

  l_Bj   SILTATION BASIN


Miiiiiiimn  GAS CONTROL/VENTING
           TRENCHES

  [23   OPERATIONAL FACILITIES


     *u  DISPOSAL TRENCHES



      5-11

-------
     2.  Sludge-only area fill

         a. area fill mound
         b. area fill layer
         c. diked containment

     3.  Codisposal

         a. sludge/refuse mixture
         b. sludge/soil  mixture
As  shown  in Table  3-7,  the  most  significant features  affecting method
selection are:
     1.  Sludge percent solids
     2.  Sludge characteristics (stabilized or unstabilized)
     3.  Hydrogeology (deep or shallow groundwater and bedrock)
     4.  Ground slopes
Having chosen  a site  (Chapter  4)  and  a  landfill ing method  (Chapter 3)
appropriate  to  that  site,  a  suitable  design  must  be  established.
Sections 5.5,  5.6,  and 5.7  discuss  considerations that  are  relevant to
trench, area  fill,  and codisposal  landfills  respectively.   In addition,
Chapter  10,   Design   Examples,  provides  an  illustration   of   how  a
landfill ing method is selected  for a given site.
5.5  Sludge-Only Trench Designs


In  a  sludge-only trench  operation,  sludge is placed  entirely below the
original ground surface.  Sludge is usually dumped directly into trenches
from haul vehicles.  On-site  equipment  is  used only to excavate trenches
and apply cover;  equipment  does not  usually  come into  contact  with the
sludge.
Sludge-only  trenches  have been  further classified  into  narrow trenches
and  wide  trenches.     If  one  of  these  landfill ing  methods  has  been
selected,  design  of  the filling  area  consists  primarily  of determining
the following parameters:
     1.  Excavation depth
     2.  Spacing
     3.  Width
     4.  Length
     5.  Orientation
     6.  SI udge fill depth
     7.  Cover thickness

                                    5-12

-------
A  methodology  for  determining  these  parameters  is  included  below  in  Table
5-5.

                                                TABLE  5-5

                    DESIGN  CONSIDERATIONS  FOR  SLUDGE-ONLY  TRENCHES
 Design  Parameter
 Determining  Factor
                                                                       Consideration
 Excavation  Depth
  Spacing
  Width
  Length
  Orientation
Depth to groundwater
Depth to bedrock
Soil  permeability
Cation exchange capacity
  of  soil

Equipment  limitations
                        Sidewall  stability
 Sidewall  stability
                         Soil  stockpiles
                         Vehicle  access
                         Sludge solids  content
                         Equipment limitations
                         Equipment efficiencies
 Sludge solids content
 Ground slopes
 Land availability

 Ground slopes
Sufficient  thickness of soil  must  be  maintained between trench
bottom and  groundwater or bedrock.  Required minimum separation
varies from 2 to 5 ft.  Larger separations may be required for
higher than normal soil permeabilities  or  sludge loading rates.
Normal  excavating equipment can excavate  efficiently to depths
of 10 ft.   Depths from 10 to 20 ft  are  less efficient opera-
tions for  normal equipment; larger  equipment may be required.
Depths  over 20 ft are not usually  possible.

Sidewal  1  st bility determines maximum  depth of trench.  If haul
 vehicles  are to dump sludge into  trench  from above, straight
 sidewall  should be employed.  Tests  should be performed at site
 with a  loaded haul  vehicle to ensure that sidewall height  as
 designed  will not collapse under  operating conditions.

 Trench  spacing is determined by sidewall  stability.  Greater
 trench  spacing will be required when additional sidewall
 stability is required.  As a general rule, 1.0 to 1.5 ft  of
 spacing should be allowed between  trenches for every 1 ft  of
 trench  depth.

 Sufficient space should be maintained  between trenches for
 placement of trench spoil stockpiled for  cover as well as  to
 allow  access and free movement by  haul vehicles and operating
 equipment.

 Widths  of 2 to 3 ft for typical sludge with solids content from
 15 to 20%.  Widths  of more than 3  ft for  typical sludge wit*i
 solids  content more than 201.  Certain sludge (e.g., polymer
 treated)  may require higher solids contents before these
 widths  can apply.

 Widths  up to 10 ft for typical equipment  (such as front end
 loader) based on solid ground alongside  trench.  Widths up
 to 40 ft  for some equipment (such  as a dragline) based on
 solid  ground.  Unlimited widths for  cover applied by equipment
 (such as  bulldozers) which proceed out over sludge.
                                                    Trenching machine
                                                    Backhoe
                                                    Excavator
                                                    Track dozer
                                                    Track loader
                                                    Dragline
                                                    Scraper
                                                      Typical  Widths

                                                          2 ft
                                                          2-6  ft
                                                          4-22 ft
                                                          _>10  ft
                                                          MO  ft
                                                          _>40  ft
                                                          >20  ft
 If sludge  solids are low and/or trench  bottoms not level,
 trench  should be discontinued or dikes  placed inside trench to
 contain sludge  in  one area and prevent  it  from flowing over
 large area.

 Trenches should be parallel to optimize land  utilization.

 For low solids  sludge, axis of each  trench  should be parallel
 to topographic  contours to maintain  constant  bottom elevation
 within  each  trench and prevent sludge  from  flowing.  With
 higher  solids sludge, this requirement  is  not necessary.
                                                       5-13

-------
                          TABLE 5-5  (Continued)
Design Parameter
Sludge fill depth
Cover thickness
Determining Factor
Trench width
Cover application method
Trench width
Cover application method

Trench width
2-3 ft
> 3 ft
TlO ft
Trench width
2-3 ft
> 3 ft
TlO ft
Consideration
Cover appl ication
method
Land-based equipment
Land-based equipment
Sludge-based equipment
Cover appl ication
method
Land-based equipment
Land-based equipment
Sludge-based equipment

Minimum distance
from top
1-2 ft
3 ft
4 ft
Cover
thickness
2-3 ft
3-4 ft
4-5 ft
1  ft = 0.305 m
Trench  spacing  is  perhaps  the most  important  and  yet  most  difficult
design parameter to  determine.    Trench  spacing  is  defined as  the  width
of  solid  undisturbed   ground   which  is  maintained  between   adjacent
trenches.  Generally,  trench spacing  should  be as small  as  possible  to
optimize  land  utilization  rates.   However,  the trench  spacing must  be
sufficient to  resist  sidewall  cave-in.   Failure of the trench  sidewalls
is  a  safety  hazard  and  reduces the  volume  of the trench available  for
disposal.   Factors  to  consider in  determining trench  spacing  include:
(1) the weight  of  the excavating machinery,  (2)  the  bearing  capacity  of
the soil  (which  is  a factor of  soil  cohesion, density, and  compaction),
(3) saturation  level  of the soil  (which  may be significantly influenced
by  the moisture  content of the  sludge deposited),  (4)  the depth of  the
trench, and (5)  soil stockpiling and  cover placement  procedure.
A  test  which  is  used primarily  to determine  the adequacy  of  soils  in
highway construction  provides  general  guidance  in  determining trench  con-
figurations  (spacing  and depth).  This test  determines  the  stability  of a
soil  by means  of the Hveem  stabilometer,  which measures the transmitted
horizontal pressure due  to  a vertical  load.  The  stability,  expressed  as
the resistance  value  (R),  represents the shear resistance  to plastic de-
formation  of a  saturated  soil at  a  given  density  [3].    This  test  is
described  under  AASHO  TUB   (American  Association  of   State   Highway
Officials).

A  general   rule  of thumb  to  follow in establishing trench spacing  is  that
for every  1  ft  (0.3 m) of trench  depth,  there should be 1  to 1.5  ft  (0.3
to 0.5  m)  of space between  trenches.   If  large  inter-trench spaces are
not  practical,  the problem  of sidewall  instability may  be  relieved  by
utilizing  one of the  four trench  sidewall variations  shown  in Figure  5-2.
In  any  event,  test  cell   trenches  should  be  used  to   determine  the
operational  feasibility  of  any  trench  design.    Such tests should  be
                                    5-14

-------
                              FIGURE 5-2

                       TRENCH SIDEWALL VARIATIONS
    TYPE I
                       TYPE 2
                                          TYPE 3
                                                                 TYPE 4
performed by excavating  adjacent  trenches  to the specified depth, width,
and spacing.  A haul vehicle fully loaded with sludge  should  then  back  up
to the trench to determine if the sidewall stability is sufficient.
Using the considerations  included  in  Table 5-5, design parameters can  be
determined for a variety of sludge and site conditions.  These considera-
tions have been employed to develop some alternative design  scenarios  for
trenches shown in  Table 5-6.   In some cases,  sludge  and site conditions
may indicate that  it  is  wholly appropriate to  utilize  all  of the design
parameters shown  in  one  of these  trench  scenarios for  application  to  a
real world situation.   However, because  of the  great  variety of sludge
and  site  conditions and  their combinations,  some adaptation of one  of
these scenarios will  be  necessary in m ost   ases.  In  any event, design
 parameters should  not  be merely extracted from  these  tables; parameters
 should   always    be   well-considered   and   tested    before   full-scale
 application.  An  example  of  a trench design  (which utilizes these tables
 initially, followed  by  engineering  investigation  and  field testing)  has
 been included in Chapter  10,  Design Examples.
      5.5.1  Narrow Trench
 Narrow trenches have  widths  less  than 10 ft  (3.0  m)  and usually  receive
 low solids  sludge with  solids  contents  as  low  as 15%.   Excavation  and
 cover application  in  narrow trench operations is  via  equipment based on
 solid  ground alongside  the  trench.    Illustrations  of  typical   narrow
 trench operations are included as Figures 5-3 and  5-4.


 The method of sludge  placement  in a narrow  trench is  dependent upon  the
 type of haul vehicle  and  upon  trench  sidewall  stability.  Usually  trench
 sidewalls are sufficiently  stable  and  sludge may be dumped from the  haul
                                    5-15

-------
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                                                   5-16

-------
                  FIGURE  5-3



CROSS-SECTION OF TYPICAL  NARROW TRENCH  OPERATION
                  FIGURE  5-4




             NARROW  TRENCH  OPERATION
                    5-17

-------
vehicle  directly   into   trenches.     However,   if   sidewalls   are  not
sufficiently  stable,  the  sludge may  be delivered  to  the  trench  in  a
chute-extension similar to that found on concrete trucks or pumped  in via
portable pumps.   In some cases  (particularly  in wet weather)  it  may be
necessary to  dump the sludge  on solid  ground  near  the trench  and have
on-site equipment push the sludge into the trench.
     5.5.2  Wide Trench
Wide trenches have widths  greater  than  10  ft (3.0 m) and usually receive
higher solids sludge with  solids contents  of 20%  and more.  Excavation  of
wide trenches  is usually  via  equipment which  enters  the trench itself.
Cover application may be by equipment based on  solid ground alongside the
trench, but  is  usually accomplished by  equipment that  proceeds out over
the sludge spreading a  layer  of cover  soil  before  it.    Illustrations  of
typical wide trench operations are included as  Figures 5-5 and 5-6.
                              FIGURE 5-5

                          WIDE TRENCH OPERATION
                                     5-18

-------
                               FIGURE  5-6

             CROSS-SECTION  OF  TYPICAL  WIDE  TRENCH OPERATION
       EXCAVATED
         DEPTH
          6'
The method  of sludge placement  in  wide trenches  may  be either  (1)  from
haul vehicles  directly  entering the trench  and  dumping sludge in  3  to 4
ft  (0.9 to  1.2 m)  high  piles  or (2) from haul vehicles  parked  at the top
of  trench sidewalls  and dumping  sludge  into  the  trench.  For the  first of
these  two  cases sludge  should  have a  solids content  of  32% or  more  to
ensure  that the sludge will  not slump  and  can  be  maintained in  piles.
For the second  of  these cases, sludge  should have a solids  content  less
than 32% to ensure that it will  flow evenly  throughout  the trench and not
accumulate  at the dumping  location.   Of course, when  sludge  is  free-
flowing, some means  will  be needed  to  confine  the  sludge to  specific
areas  in a  continuous trench.  Dikes are  often  used for  this  purpose as
illustrated in Figure 5-7.
                              FIGURE  5-7

                 CROSS-SECTION OF WIDE TRENCH  WITH  DIKES
       DEPTH
                                    5-19

-------
5.6  Sludge-Only Area Fill Design
In  a  sludge-only  area  fill operation,  sludge  is  usually placed  entirely
above  the original  ground  surface.   The sludge  as  received is  usually
mixed  with  soil to  increase  its  effective solids  content and  stability.
Several  consecutive  lifts of  this  sludge/soil  mixture  are   usually  then
applied  to  the filling  area.   Soil  may  be  applied for  interim  cover  in
addition  to  its  usual   application  for final  cover.    On-site  equipment
usually  does  come into  contact  with  the sludge while  performing  functions
of  mixing the  sludge with  soil; transporting  this  mixture  to  the  fill
area;  mounding or layering  this mixture; and  spreading  cover  over  the
mixture.
Sludge-only  area  fills  have  been   further  classified  into  area  fill
mounds,  area  fill  layers,  and   diked  containments.    If  one  of  these
landfill ing  methods  has been  selected,  design  of  the  filling area  may
consist  primarily of determining  the  following parameters:
     1.   Bulking ratio
     2.   Cover application procedure
     3.   Width (of diked containment)
     4.   Depth of each lift
     5.   Interim cover thickness
     6.   Number of lifts
     7.   Depth of total fill  (of  diked containment before  final  cover)
     8.   Final  cover thickness
A  methodology  for  determining  these factors  is  included  below  in  Table
5-7.

                                 TABLE 5-7

             DESIGN CONSIDERATIONS  FOR SLUDGE-ONLY AREA  FILLS
Design Parameter


Bulking ratio










Consideration

Method Solids Content
Area fill mound 20-28%
28-32%
> 32%
Area fill layer TS-20%
20-28%
28-32%
> 32%
Diked 70-28%
containment 28-32%
J> 32%
Method Solids Content

Bui king
Ratio
2 soil 1 si udge
1 soil 1 sludge
0.5 so 1 :1 slue*""
1 soil 1 sludge
0.5 soil :1 si udge
0.25 soil :1 sludge
Not required
0.5 soil :1 sludge
0.25 soil :1 si udge
Not required
Cover Application Procedure
       Cover application
        procedure
Area fill mound  ^ 20%
Area fill layer  ]> 15%
Diked         20-28%
 containment    > 28%
Sludge-based equipment
Sludge-based equipment
Land-based equipment
Sludge-based equipment
                                     5-20

-------
                                  TABLE  5-7  (Continued)
         Design Parameter
                                               Consideration
         Width (of diked
          containment)
                          Cover Application Procedure   Equipment Used     Width
    Land-based equipment
    Sludge-based equipment
     Dragline
     Track  dozer
 £ 40 ft
Not limited
                                  Method
         Depth  of each 1 ift
         Interim cover
         thickness
         Number of 1ifts
    Area fill mound
    Area fill layer

    Diked containment
      Method	

    Area fill mound
    Area fi11 1ayer
    Diked containment
  Sludge Solids

    > 20%
   15~-20%
    >_ 20%
   20-28%
    >_ 28%

  Cover Application
 	Procedure

Sludge-based  equipment
Sludge-based  equipment
Land-based equipment
Sludge-based  equipment
Lift Depth

   6 ft
   1 ft
 2-3 ft
 4-6 ft
 6-10 ft

  Interim Cover
   Thickness

     3 ft
   0.5-1 ft
     1-2 ft
     2-3 ft
Method
Area fill mound
Area fill layer
Diked containment
Sludge Solids
Content
20-28%
> 28%
T 15%
> 20%
                                 No. of Lifts

                                   1 maximum
                                   3 maximum
                                 1-3 typical
                                 1-3 typical
         Depth  of total
          fill (of diked
          containment before
          final cover)
         Final  cover
          thickness
 Cover Application Procedure

    Land-based equipment

    Sludge-based equipment



	Method	

   Area fill mound
   Area fill layer
   Diked containment
      Depth of Total Fill

    No higher than 3 ft
      below top of dikes
    No higher than 4 ft
      below top of dikes
                                                     Cover  Application
                                                       Procedure
                      Final Cover
                       Thickness
    Sludge-based equipment    1  ft
    Sludge-based equipment    1  ft
    Land-based equipment     3-4  ft
    Sludge-based equipment   4-5 ft
         1 ft = 0.305 ft
Using  the considerations  included  in Table 5-7,  the  design  parameters can
be  determined  for   a   variety  of  sludge  and  site   conditions.      These
considerations  have  been  employed   to  develop   some   alternative  design
scenarios for  area  fills  which  were  included  earlier  in  Table 5-6.   An
example  of  an  area   fill  design  (which  utilizes  these tables  initially,
followed  by investigation  and  testing)  has  been  included   in  Chapter  10,
Design Examples.
                                             5-21

-------
     5.6.1   Area Fill  Mound
At  area  fill   mound  operations,  sludge/soil   mixtures  are  stacked  into
mounds  approximately  6  ft (1.8  m)  high.  Cover soil  is  applied  atop each
lift  of mounds  in  a 3 ft  (0.9 m) thickness.   The cover  thickness  may  be
increased to 5 ft  (1.5  m) if additional  mounds are  applied atop  the first
lift.   Illustrations  of typical  mound operations are  included as  Figures
5-8 and 5-9.
                                FIGURE  5-8

            CROSS-SECTION  OF TYPICAL AREA FILL MOUND  OPERATION
                                        REMOVE FOR USE
                                        AS SLUDGE BULKING
                                        AGENT
                        FINAL COVER
                 FUTURE
                 DRAINAGE
                 DITCH
            INTERMEDIATE COVER
                (31 THICK)
                      LEACHATE CONTROL
SLUDGE/SOIL
 MIXTURE
                                FIGURE  5-9

                         AREA FILL MOUND OPERATION
                                      5-22

-------
Sludge  as  received at the landfill  is  usually mixed with a bulking  agent.
The  bulking agent  absorbs excess moisture  from the  sludge and  increases
its  workability.   The amount  of soil  needed to  serve as  an additional
bulking  agent  depends  upon  the solids  content of  the  sludge.   Generally
the  soil  requirements shown  in  Table  5-7 may  serve as  a guideline.   Fine
sand  appears to  be  the most suitable  bulking  agent because  it  can  most
easily  absorb  the excess moisture from  the  sludge.
      5.6.2   Area Fill Layer
At  area  fill  layer operations,  sludge/soil mixtures  are spread evenly  in
layers  from 0.5 to  3 ft  (0.15  to  0.9 m) thick.   This  layering  usually
continues   for  a  number  of  applications.     Interim   cover   between
consecutive layers may  be applied  in 0.5 to  1 ft  (0.5 to  0.3 m)  thick
applications.   Final  cover should  be at  least  1  ft  (0.3 m)  thick.   An
illustration  of a  typical  area fill layer operation  is included as Figure
5-10.
                               FIGURE  5-10

            CROSS-SECTION OF TYPICAL AREA FILL  LAYER OPERATION
                                           REMOVE FOR USE
                                           AS SLUDGE BULKING
                                           AGENT •
                             INTERIM COVER
                             (0.5-1 THICK).
              LEACHATE COLLECTION
                                                      FUTURE
                                                      DRAINAGE
                                                      DITCH
SLUDGE/SOIL MIXTURE
   (3' THICK)
     5.6.3   Diked Containment
At diked  containment operations,  earthen dikes are constructed  to form a
containment  area  above the  original  ground  surface.   Dikes  can  be of
various  heights,  but  require side  slopes  of  at  least  2:1  and  possibly
3:1. A 15 ft  (4.6  m) wide road, covered  with gravel  should be constructed
atop the  dikes.
                                     5-23

-------
Sludge may  be  either (1)  mixed with soil bulking  for  subsequent transport
and dumping  into the containment  area  by on-site equipment  or (2) dumped
directly  into  the  containment area by haul  vehicles without  bulking soil.
Large quantities of imported  soil  may be  required  to meet  soil  require-
ments  for  dike  construction  and  bulking  since  diked  containments  are
often constructed  in high groundwater areas.


Sludge is dumped into diked containments in lifts before  the application
of  interim  cover.    Often  this   interim   cover  is  a  highly  permeable
drainage  blanket which  acts  as  a leachate  collection system  for sludge
moisture  released  from the sludge lift above.  Final  cover should be of a
less  permeable  nature and  should  be  graded  even with  the  top  of  the
dikes.    An  illustration of  a  typical  diked  containment  operation  is
included  as  Figure  5-11.
                               FIGURE 5-11

          CROSS-SECTION OF TYPICAL DIKED CONTAINMENT  OPERATION
             MIN. OF 15' OR AS REQUIRED
             FOR CONSTRUCTION EQUIPMENT
      EXTEND TO PREVENT
      DISCHARGE ON SLOPE
      FACE
                  3
                                                     UPPER SLUDGE LAYER
                                                    MIDDLE DRAINAGE BLANKET
5.7  Codisposal  Designs
Codisposal  is  defined  as the receipt of sludge  at  a  conventional  landfill
receiving municipal  refuse.  Two  methods  of codisposal  have  been identi-
fied:   (1)  sludge/refuse  mixture and  (2)  sludge/soil  mixture.   Design
considerations  for  codisposal  landfills have been  included  in Table 5-8.
                                    5-24

-------
                                TABLE 5-8

              DESIGN CONSIDERATIONS FOR CODISPOSAL OPERATIONS
     Design Parameter
                                  Consideration
                     Method
Bui king
 Agent
                                     Sludge Sol ids
                                      Content
Bui king
 Ratio
Bui king Ratio





Sludge/refuse Refuse
mixture


Sludge/ soil Soil
mixture
3-101
10-17%
17-20%
> 20%
> 20%

7 tons refuse:! wet ton sludge
6 tons refuse:! wet ton sludge
5 tons refuse:! wet ton sludge
4 tons refuse.! wet ton sludge
I soil :1 sludge

    1 ton = 0.907 Mg
This  manual   does  not  provide  all  details  on  the design  of  a  refuse
landfill  receiving  sludge.    Rather,   only  those  design  features which
distinguish  refuse  landfills  receiving  sludge  from those  not  receiving
sludge  are addressed.   The EPA  document,  "Sanitary Landfill  Design  and
Operation" [4]  should  be consulted for information  relating to design  and
operation  of  a  refuse  landfill.
     5.7.1   Sludge/Refuse Mixture
In  a  siudge/refuse mixture operation,  sludge  is  delivered to the working
face  of the landfill  where it is mixed and  buried  with  the refuse.  Most
of  the  considerations  relative  to  the  receipt   of  sludge  at  refuse
landfills  are  operational.  These problems and solutions are  described  in
Chapter 6,  Operation.   Nevertheless,  some of  the  considerations require
planning and design  solutions.   These  are described in this section.


The  first  problem encountered  at   codisposal  sites  is  sludge handling
difficulty  due  to  the  liquid  nature  of sludge relative  to  refuse.
Difficulties  include  (1)  the   sludge  is  difficult  to  confine at  the
working  face  since  it will  readily flow,  and  (2)  equipment  slips  and
sometimes  becomes stuck  in  the sludge  while operating  at  the working
face.  These difficulties  can be minimized if  proper planning is employed
to control the quantity  of sludge received at  the refuse landfill.  Every
effort  should be made  not  to  exceed  the  absorptive  capacity of  the
refuse.    Obviously,   the  maximum  allowable  sludge  quantity  will  vary
depending  largely on the  quantity of  refuse  received  and  the  solids
content of  the sludge.   Some suggested bulking  ratios  for si udge/refuse
mixtures at  various   sludge  solids  contents were included  previously   in
Table 5-8.  In any event determinations should be  made  on a  site-by-site
basis using test  operations.
                                    5-25

-------
A  second planning  and  design consideration  for  sludge/refuse  mixture
operations  concerns  leachate control.   The impact  of  sludge receipt on
leachate  is   highly  site-specific.     Generally,  increased  leachate
quantities  should be  expected.  Leachate control  systems  may have to be
designed or modified accordingly.


A third  planning  and  design consideration is storage for  sludge received
in  off-hours.    In   many cases  sludge  is  delivered  around  the  clock,
whereas, refuse  delivery is  confined  to certain  hours.   Sludge storage
facilities may have  to be installed to  contain  sludge  overnight or  over
weekends until  sufficient refuse bulking  is delivered.
     5.7.2  Sludge/Soil Mixture
In a sludge/soil mixture operation, sludge  is mixed with  soil  and  applied
as cover  over  completed refuse  fill  areas.  Most  of the considerations
associated  with  these operations  are  also of  an  operational  nature  and
are  addressed  in Chapter  6, Operation.    However,  at the  planning  and
design stage, an area must be reserved for  sludge/soil mixing.  This  area
must be sufficiently sized  and  have sufficient  soil  available for sludge
bulking.  Information on  a suggested  bulking  ratio was included in  Table
5-8.   The  soils  in  this  area  must  also  be   adequate  to  protect  the
groundwater.


5.8  Environmental Safeguards
Groundwater  protection is  the most  difficult  and  costly  environmental
control  measure  required  at  many  sludge   landfills.     Additionally,
contamination of  surface  water must not be allowed.  Other  environmental
considerations  are  methane  gas  migration  and  accumulation  in   nearby
structures, odors, dust,  vectors, and/or aesthetics.  Presented  below  are
design  concepts  that  minimize  or  prevent  adverse  environmental  impacts
from   leachate   generation  and  methane   gas   migration.     The   other
environmental  controls are discussed  in   Chapter  6,  Operations,  since
their  control is  more  a function  of operation  than  design.


     5.8.1  Leachate Controls
Leachate can  be  generated simply from the  excess  moisture in the  sludge
as  received  at  the landfill.   Rainfall  on the surface  of the fill  area
can add  a  limited  amount  of water to the  interred  sludge.  However, the
surface  of the  landfill  should  be  sloped enough  to  cause most  of the
                                   5-26

-------
rainfall to drain.   Other  storm water runoff must be diverted around  the
landfill,  and  the  landfill  must  be  located  above  historically high
groundwater  elevations.    These  positive  controls will   minimize   the
quantity  of leachate to be generated.   In  dry areas  where the rate  of
evaporation  is  much higher than  the  precipitation,  zero infilration  can
result, thereby  limiting the  amount of leachate generated by the sludge.
Table 5-9  details  the  range of constituent concentrations in leachate  at
sludge  landfills.   It  should be  emphasized  that  the leachate depends  on
the  nature of  the  sludge interred.   Moreover,  if the  site  has been
properly  designed, these  constituents  can be  effectively  attenuated  by
soils or collected  and  subsequently treated.

                                TABLE  5-9

                    RANGE OF CONSTITUENT CONCENTRATIONS
                   IN LEACHATE FROM  SLUDGE  LANDFILLS  [5]
                   (in mg/1  unless otherwise indicated)
Constituent
Concentration
Constituent
Concentration
cl/l
so4
TOC
COD
Ca
Cd
Cr
Zn

20-600
1-430
100-15,000
100-24,000
10-2,100
0.001-0.2
0.01-50
0.01-36

Hg
Cu
Fe
Pb
TKN
Fecal
Col iform
Fecal
Streptococcus
0.0011-0.0002
0.02-37
10-350
0.1-10
100-3,600
2,400-24,000
MPN/100 ml
2,100-240,000
MPN/100 ml
Leachate  may  enter  into  the  water  system  through  essentially  two
pathways:


    1.  Percolation  of  the  leachate, laterally  or  vertically,  through
        soil into the groundwater aquifers (Figure 5-12)

    2.  Runoff of leachate outcroppings into surface waters


Careful site selection and attention to design considerations can prevent
or minimize leachate contamination of groundwater and surface water.  The
control of leachate may be accomplished through:
                                    5-27

-------
                               FIGURE  5-12

                     WATER BALANCE  AT  SLUDGE LANDFILL


                                    I PRECIPITATION
                                    I
                                            EVAPOTRANSPIRATION
              SURFACE
              RUNOFF
                         'POSSIBLE GROUNDWATER CONTOURS
    1.   Natural  conditions and attenuation

    2.   Imported soils or soil amendments  used as liners and/or  cover

    3.   Membrane liners

    4.   Collection and treatment


          5.8.1.1   Natural Conditions  and  Attenuation
Leachate  may  be contained  on-site  due  to  natural   hydrogeological   and
topographic  conditions  or through  use  of man-made  facilities.    Hydro-
geological characteristics of the site  affecting leachate containment  are
primarily  the  hydraulic conductivity of  the underlying  strata  and  the
depth to usable groundwater.
                                     5-28

-------
Contaminants  in  leachate  can be attenuated when passing through  soils  by
physical-chemical ,   mechanical ,   and/or   biological   processes.     The
mechanisms by which these  processes  are performed  include:
    1.  Filtration                     4.  Chemical  precipitation

    2.  Ion exchange                   5.  Biodegradation

    3.  Adsorption                     6.  Complexation


The properties of the  soil  environment that  influence  the  extent to  which
these mechanisms are operative  [6][7] include:


    1.  Soil grain  size                5.  Eh

    2.  Organic content                6.  Hydrous  oxides

    3.  Cation exchange capacity       7.  Fill  lime content

    4.  pH


The  relative  importance  of  one  property   over  another  is   not  well
documented.   It  is  likely  to vary  from  one situation to  the  next [?].
For  example,  some  studies   indicate  that the  cation  exchange capacity
(CEC)  of clay  minerals  are the  dominant  removal  mechanisms  for some
substances  (K,  Nfy, Mg,  Si, and  Fe),  while  precipitation was observed
to  be  the  principal attenuative mechanism for  other substances (Pb,  Cd,
Hg, and  Zn)  [9],    Other  studies  have indicated  that  the   following soil
properties are most useful  in attenuating pollutants from  soils [9]:


    1.  Clay content

    2.  Content of  hydrous oxides, primarily iron oxides

    3.  pH and content of free lime

    4.  Surface area per unit weight of soil


In another study [10],  clay minerals were ranked  according to  their  at-
tenuating capacity.   It  was  observed  that montmorillonite  attenuated
pollutants  four  times  better  than  illite  and  five  times  better  than
kaolinite.  These ratios are  nearly  identical  with  the CEC for the three
clays (Table 5-10)  [6].
                                   5-29

-------
                               TABLE 5-10

          ATTENUATION  AND  PERMEABILITY PROPERTIES OF CLAYS  [6]
1

0
2
4
8
16
32
64
100
2
4
8
16
16
32
64
100
4
16
8

8

8


Material

Montmorillonite
Monttnorillonite
Montmorillonite
Montmorillonite
Montmorillonite
Montmoril lonite
Montmorillonite
Montmoril lonite
Kaol inite
Kaol mite
Kaol inite
Kaol inite
Kaolinite
Kaol inite
Kaolinite
Kaol inite
Illite
IlUte
Montmorillonite
+ 8 Kaolinite
Kaol inite
+ 8 lllite
Kaolinite
+ 8 Illite
+ 8 Montmoril lonite
Cation
exchange
capacity
meq/lOOg
0.0
1.7
3.3
6.8
13.3
27.3
50.7
79.5
0.2
0.5
1.0
2.2
.
4.3
8.2
15.1
0.7
2.7

7.6

2.8


9.2
Bulk
density
g/cm^
1.71
1.71
1.77
1.79
1.87
1.55
1.23
0.84
1.68
1.76
1.80
1.87
1.94
1.66
1.22
0.90
1.80
1.83

1.95

1.95


1.64
Initial
hydraulic .
conductivity
cm/sec
1.27E-03
9.45F-04
4.34E-04
4.70E-04
1.22E-05
1.27E-06
3.05E-07
7.26E-07
7.44E-04
4.78E-05
9.90E-04
2.86E-05
1.09E-Q6
2.40E-06
5.45E-07
2.98E-07
8.17E-04
2.68E-05

5.35E-07

1.48F-06


8.08F-06
                 Quartz sand added to make 100%
                 Exponential notation:  E-03 means x
The  individual  chemical  constituents  of the  leachate examined  in  this
study were  ranked according to  their degree of  attenuation by the  three
clays as follows:
         Cl < COD  <  Na  <  NH4 < K < Mg < Si < Cd < Zn < Pb  < Hg
In one  of  the  previously mentioned  studies  [6], physical characteristics
of representative whole soils  from the  major soil  series  in the  United
States  were determined  (Table 5-11).  These data were correlated  with  the
attenuative capacity of each  soil.  Results  from  these studies  indicate
that the clay  content  of a soil  and the surface area per unit  weight were
by  far the  best  single predictors  of  a  soil's  attenuation  properties
[9].  The  relative rate  of movement through the soil is  also  important in
site design.   Again, clay soils exhibit the slowest  movement.   In studies
in Omaha,  Nebraska, leachates  travelled only  160  ft (50 m)  in  58 years
[5] through a  clay soil.
                                     5-30

-------
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                                  5-31

-------
Although the capacity  of  soils  to attenuate leachate is a  site  selection
and design consideration,  the  long term effectiveness of the  contaminant
removal  processes  is not  verified.   A  soil  that  offers  moderately  low
permeability,  a high  clay  content,  high  CEC,  and  relatively  high  pH
(>6.0),  is preferred over  soils composed of coarse-grained  particles  with
high permeabilities and low CEC values.

Information on  soil  properties  can be obtained from  several  sources,  but
the Soil Conservation  Service  (SCS)  soil  surveys are the primary  source.
Well  logs  can  also  offer additional  data  on  soils  and geology.    Soil
surveys  will  normally provide  soil  maps delineating the  apparent boun-
daries of soil  series  with their  surface texture.  A written  description
of each  soil  series  provides  limited  information on  chemical  properties,
engineering   applications,  interpretive   and   management   information,
slopes,  drainage,  erosion potentials,  and  general  suitability  for  most
kinds of crops  grown  in the particular  area.   Additional   information  on
soil characteristics  and  information  regarding  the  availability of  soil
surveys  can  be obtained  directly from the SCS.   The SCS  serves  as  the
coordinating  agency for  the  National  Cooperative  Soil  Survey,  and  as
such, cooperates with  other  government  agencies, universities, and agri-
cultural extension services  in  obtaining  and  distributing  soil   survey
information  [11].     For  insufficient  data   and/or for   site  specific
verification,  tests should  be  performed   on   site  by  experienced  soil
scientists.
The  methods of  determining some  of these  various  soil  properties  are
presented  in  Table 5-4.   Others may be  ascertained from  any number  of
texts [12][13][14],
          5.8.1.2  Imported Soils  and Soil Amendments
If clayey  soil  exists only on  a  part of the  site  or at certain  depths,
these suitable  soils can be  selectively excavated and  used  to line  the
sludge  landfill.    It  is highly  desirable to  use  on-site soils  to  the
maximum extent  possible  to  save the cost of purchasing  and hauling  soils
to the  site.   However,  if  on-site  soils  and other  conditions  are  not
adequate  to contain  leachate  or  attenuation  is   inadequate  to  protect
groundwater,  soil   permeabilities  can   be  lowered  by  the  addition  of
imported clays  or  polymeric  materials.   Clay minerals such as  montmoril-
lonite  or  bentonite  and  artificial  soil  amendments are  available  commer-
cially  if  sufficient  quantities of  natural  clay are not present on  site.
In areas of high  rainfall,  it  will  be  necessary to incorporate leachate
collection  systems  into  the design  to prevent  water from ponding.
                                    5-32

-------
The   basic  procedure   for   incorporating   permeability-reducing   soil
additives  follows [15]:
     1.  Select  the most  cost-effective  soil  additive.   Determine  the
         rate  of application  of the  additive.    This  rate  is based  on
         characteristics  of the existing  soil  (e.g.,  soil particle  size
         and void space).   The  amount  of additive should  be such that  the
         amended  soil  has   a   permeability   of   10~6   to  10"?  cm/sec.
         Usually  it  is  advisable to have  an  independent  soil  testing  lab
         identify the most  cost  effective soil  amendment  and  mix,  but  the
         proper  mix  can  be determined empirically by taking  core  samples
         and adding  various  mixes  of soil amendments.  The data may  then
         be  plotted  on a  graph and  the mixes required  for  the  desired
         permeability established.   It  is often  useful  to determine  the
         plasticity  of the mix  in addition to the permeability.

     2.  Prepare  and grade  the  site.    Remove  all  tree  roots,  branches,
         rocks or other  items that  may  penetrate the amended  soil  layer.
         The bottom  of  the  site  should  be graded  to  allow  the leachate
         to drain to a centralized  collection point.

     3.  Apply the additive  and  disc  it  into  the  existing soil  to  a depth
         of  approximately  12  in.   (30  cm).    The  depth  of  artificially
         applied  or  amended  soil  liners  is best  determined on  a case-by-
         case basis  to obtain  a  safe yet cost-effective  design.

     4.  Compact the soil-additive  mixture to assure a  watertight  barrier
         through differential  settlement.

     5.  Flood the  area  with  water to  completely saturate  the  amended
         soil.   Clayey  materials are  very impermeable  to water movement
         when moist  but  can develop cracks when  dry.   Thus,  clay  liners
         must  be  kept  moist   prior  to  depositing   sludge  to   ensure
         integrity.

     6.  Cover the clay liner  with  a  12  in.  (30 cm) layer of  native  soil
         to protect  it during  the landfill ing operation.
         5.8.1.3  Membrane Liners
The  use of  membrane  liners for  containment  of leachate  has  received
attention  in  the literature  [16][17][18][19][20],  and  may  be  practical
for application  at  area  fill and wide  trench  operations.  Liners  should
be  used when  soil  permeabilities  or  soil  depths  are   not  adequate  to
protect the  groundwater  or  when  required by  State  regulations.   It  is
                                     5-33

-------
preferable  to   use  Jji   situ   soils   whenever   possible.    However,   when
available site  conditions  or  laws dictate that  a liner must be  used,  many
types of  membrane  and other thin layer liners  are currently available, as
indicated in  Table  5-12.
                                    TABLE  5-12


                        LINERS FOR SLUDGE LANDFILLS [16]



                     Asphalt compositions

                          - Asphaltic concrete
                          - Hydraulic asphaltic concrete
                          - Preformed asphaltic panels laid on concrete surfaces
                          - Catalytically blown asphalt sprayed on soil
                          - Emulsified asphalt sprayed on  soil or on fabric matting
                          - Soil asphalt mixtures
                          - Asphalt  seals

                     Portland cement compositions

                          - Concrete with asphalt seals
                          - Soil cement with asphalt seals

                     Soil sealants

                          - Chemical (soil  amendments)
                          - Lime
                          - Rubber and plastic latexes
                          - Penetrating polymeric emulsions

                     Liquid rubbers sprayed

                          - Rubber  and plastic latexes
                          - Polyurethanes

                     Synthetic polymeric membranes

                          - Butyl rubber
                          - Ethylene propylene rubber (EPDM)
                          - Chlorosulfonated polyethylene  (Hypalon)
                          - Chlorinated polyethylene (CPE)
                          - Polyvinylchloride (PVC)
                          - Polyethylene (PE)
 Synthetic  polymeric  and  asphaltic materials  are the most  common  membrane
 liners  used  for  landfills.    Factors  to   consider  in  selecting  a  liner
 are:
     1.   Effectiveness  (It  appears that  some  materials may not be  accept-
          able for use  with  certain wastes [21].   Before  selecting  a liner,
          pretesting or literature  review should  be performed.)

     2.   Cost,  both acquisition  and  installation  (Table  5-13)

     3.   Installation  time

     4.   Durability
                                           5-34

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                                     TABLE  5-13

                    ESTIMATED COSTS  FOR  LANDFILL  LINERS  [16]
                    (Note:   Figures  presented are  1973 costs)
Item
Butyl rubber
Chlorinated polyethylene
(CPE)
Chlorosul fonated
polyethylene
Ethyl ene propylene
rubber (EPDM)
Neoprene
Polyethylene film
Polyvinyl chloride
Thickness ,
mils
31.3 (1/32")
20
20
46.9 (3/64")
62.5 (1/16")
10
20
Price of
roll goods
($/ydz)
$2.25
1.58
1.66
2.42
2.97
0.36
0.90
Installed
costa
($/yd2)
$3.25-$4.00
$2.43- 3.24
2.88- 3.06
2.65- 3.42
4.41- 5.40
0.90- 1.44
1.17- 2.16
               Soil + Bentonite
               9 Ib/yd^ (1  psf)
               Soil cement
               6 in. thick  + sealer  (2 coats--each
               0.25 gal/yd^)
               Soil asphalt
               6 in. thick  + sealer  (2 coats--each
               0.25 gal/yd^)
               Asphalt concrete--Dense-graded paving
               with sealer  coat  (Hot mix--4-in. thick)
               Asphalt concrete-Hydraulic-
               (Hot mix—4-in. thick)
               Bituminous seal
               (catalytically blown  asphalt)
               1  gal/yd^

               Asphalt emulsion on mat
               (Polypropylene mat sprayed with asphalt
               emulsion)
                                               $0.72


                                               1.25


                                               1.25

                                            2.35- 3.25

                                            3.00- 4.20
                                            1.50- 2.00
                                            (with earth cover)
                                            1.26- 1.87
               a Soil cover not included; membranes require some soil  cover, cost of which can
                range from $0.10 to $0.50/ycr per ft of depth
               b Hypalon, with nylon scrim
 0.454 kg
= 0.7646
               1 Ib
               1 ydj
               1 gal = 3.785 L
               1 in. = 2.54 cm
               1 yd' = 0.8361 n
Since  most  area  fill  landfills   extend  over  a  relatively   large
membrane  liners usually must be  spliced  during  field  installation.
seam  durability  and  the   amount   of  overlap  should   be
membrane  design.    Design  of  a  membrane/liner follows
procedures  identified  for  clay barriers:
                                                                  area,
                                                                  Thus,
                                                       considered  in
                                                   roughly  the  same
                                            5-35

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     1.  Select  a  membrane  based   on  the  above  noted  considerations
         (effectiveness, cost, installation time, and durability)

     2.  Prepare and grade the soil  surface

     3.  Compact the soil surface

     4.  Install the liner

     5.  Cover the liner with at least 12 in. (30 cm) of porous soil.  If
         equipment  is  to   be operated  over  the  sludge   or  refuse  is
         disposed, more cover may be required


It should be noted that liners have potential disadvantages, including:
    1.  The expected  life of  liners  has  not  been established.   Liners
        have been used at  landfills over a relatively short period (less
        than  10  yrs), whereas  effectiveness  must be  assured  for  many
        decades.

    2.  Sludge disposal  operations  can  tear the  liner,  causing leachate
        seepage.

    3.  Changes  in  the  hydraulic  conductivity of  the  underlying or sur-
        rounding soil cause the groundwater  to rise,  which exerts upward
        pressure on the liner.

    4.  Once  the liner  is in  place  and  sludge   is  deposited, membrane
        failure cannot be easily detected or readily repaired.
Changes in hydraulic conductivity and evaporation result when the area is
excavated  and  the overburden  removed.    The  problems  associated  with a
rising  water  table  can  be  mitigated  by  placing  a  leachate  collection
system beneath liners.  Although expensive, this will relieve pressure on
the liners and,  if properly  placed,  enable the presence and locations of
leaks to be identified.
          5.8.1.4  Collection and Treatment
If  the  site  design  includes  provisions  for  leachate  containment,  a
leachate collection system must  be  installed.   The collection system may
consist of a sump into which leachate collects and is subsequently pumped
to a  holding  tank or pond.  Leachate  may also be collected  by  a series
of drain pipes  or tiles  which  intercept and channel  the  leachate to the
                                   5-36

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surface or  to  a  sump.    Figure  5-13  depicts  representative  collection
systems.  Groundwater interceptor trenches may  be  used to  lower the water
table  in the vicinity of the fill area  (Figure  5-14).
                                 FIGURE  5-13

                     UNDERDRAIN FOR LEACHATE COLLECTION
                       tf' CLAY
                                     SLUDGE
                                         6-l2"ORAVEL OR
                                        ,CRUSHED STONE
                                             PERFORATED
                                             PLASTIC PIPE
                                  FIGURE  5-14

                  UPGRADIENT GROUNDWATER INTERCEPTOR TRENCH
                     NATURAL SOIL
                      MATERIAL
                                          ORIGINAL
                                          GROUNDWATER LEVEL
                              CUTOFF TRENCH
                                                 GROUNDWATER
                                       5-37

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 Collected  leachate  may  be treated  by  one  or  more  of  the  following
 methods:


     1.  Discharge  to  a  wastewater  collection system  or  haul  directly to  a
        treatment  plant

        a.  biological  treatment
        b.  physical-chemical  treatment

     2.  Recycle through  the landfill

     3.  Evaporation of  leachate  in  collection  ponds

     4.  On-site treatment


Depending on the leachate characteristics, volume, and  local  regulations,
 it may be possible to discharge  collected leachate to  an existing  waste-
water system  for  subsequent treatment with  municipal  wastewater.   Local
wastewater  treatment  plant  personnel  should  be  consulted  for  leachate
acceptability  to   determine special  requirements for  discharge  to the
treatment plant;  e.g.,   large  slugs of highly  contaminated  leachate may
have to be mixed with municipal wastewater to  prevent plant  upsets.


Leachate  collected from relatively  new  landfills  is  best  treated by
biological  processes   (Table  5-14)  [22],    Physical-chemical  treatment
processes  are  most  effective   in  treating  leachate  from  landfills
containing  stabilized  sludge or in  removing organic matter from  sludge
from biological treatment  units.   Activated carbon and  reverse osmosis
show promise for removing organic  matter, but their viability on a  large
scale over extended periods  has not been  verified.


                              TABLE 5-14

       EXPECTED EFFICIENCIES OF ORGANIC REMOVAL FROM LEACHATE [22]
Character of


COD/
TOC
(mg/I)
>2.8

2.0-2.3

<2.0



BOO/
COD
(mg/1)
>0.5

0.1-0.5

<0.1

Leachate


Age of
fill

Young
(<5yr)
Med i urn
(5-10 yr)
Old
(<10yr)
Effectiveness of Treatment Processes



COD
(mg/1)
>10,000

500-10,000

<500



Biological
treatment

Good

Fair

Poor

Chemical
precipitation
(mass lime
dose)

Poor

Fair

Poor


Chemical
oxidation
Ca (CIO),

Poor

Fair

Fair




°7

Poor

Fair

Fair

                                   5-38

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If discharge to the wastewater system  is  not  practical  or  if  the  leachate
is   potentially   disruptive  to  treatment   plant  operations,   on~site
treatment  or  transportation to a chemical waste  disposal  site will  have
to be utilized.
On-site treatment may consist of  recycling the  leachate through  the  land-
fill,  placing  the  leachate  in  a  shallow  basin  to  allow it to evaporate,
or installing  a  small  (specially  designed)  treatment plant on site.   The
latter alternative  should  be  avoided if  at  all  possible  due  to  its  high
cost and the unproven reliability of such small  plants.


Leachate recycling  has been shown to  be useful  because  it  [23]:


    1.  Promotes  rapid   development   of   anaerobic  decomposition  in  the
        wastes

    2.  Increases  the  rate and  predictability  of  biological  stabiliza-
        tion

    3.  Reduces  the volume of  leachate  to  be  handled  by evaporation  of
        the water during dry periods
However,  leachate  recycling  systems  are  not  feasible  at  most   sites;
specifically,  areas  with high  rainfalls  and high  application  rates  are
not suitable.  Its primary application should be  restricted to  codisposal
sites  in  climates  where  the  evaporation  rate  exceeds  rainfall  to  a
significant extent.


It  may  be valuable  to  have  contingency   plans  designed to  intercept  a
downgradient leachate  plume.   Essentially this  would consist of a  number
of  downgradient  wells  which  could be  pumped, thus  containing  the  plume.
The extracted water may  be treated and discharged.


     5.8.2  Gas Controls
Gas  is  produced  by the decomposition  of  organic matter  in  sludge.  The
primary  gases  of  decomposition are  methane and  carbon dioxide.    Some
nitrogen  and  oxygen  is  found.   Traces   of ammonia,  hydrogen  sulfide,
hydrogen, and volatile  organic  species are sometimes found in  landfills.
The amount and composition  of  gases  produced depends on the quantity and
characteristics of  sludge deposited,  the  amount of moisture present, and
other factors.   Ranges of  gas concentrations  that  may  be  expected are
shown in Table 5-15 [5].
                                    5-39

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                               TABLE  5-15

           GAS CONCENTRATIONS AT  SELECTED  SLUDGE  LANDFILLS [5]
                              (%  of sample)a
                            Sludge-Only   	Codisposal

CH4
co2
°2
N,

1
55
41
1
3

2
56
39
1
3

3
48
20
7
24

4
50
37
2
10

5
43
50
1
6

6
59
40
-
1

7
54
32
3
10

                      Totals may not add to 100 due to rounding.
The  rate  and  types  of  gas  generated depends  on the  type of  microbial
(biological)  decomposition occuring.   The amount of gas  generated  from
sludge  decomposition can  be  expected to  range  from 16  to 18  ft3/lb  (1
to  1.1  mS/kg) of  volatile matter  reduced  [24].  Five  to 8  ft3/lb  (0.3
to  0.5  m3/kg)  of  gas  is  generated  from  deposited  municipal  solid
waste).    Raw  sludges  probably  generate  somewhere between  8  and  16
ft^/lb  of  dry solids.   Digested  sludges  would  be  expected  to generate
considerably  less  gas since  most  of this  gas  quantity was  generated  in
the  digestors.   Of course, for  all  the  rates noted   above  (for  refuse  as
well  as raw  and  digested sludges)  it  should  be noted  that  the  gas  is
generated over an  extended period  that  may exceed fifty years.


Methane, like  carbon dioxide, is odorless; unlike carbon dioxide, methane
is  relatively insoluble in water.   However, when methane  is present  in
air  at  between 5 and 15%  concentrations,  and is  confined  in  an enclosed
area,  it  may  be  explosive.    Methane  can  move  by diffusion  through the
sludge  into  the atmosphere where  it is harmlessly  dissipated.   The gas
can  also  move  laterally  from  the  landfill    into  surrounding  soils,
especially  if the cover  material   is  relatively impermeable.    Through
lateral movement,  methane could seep into  nearby buildings or  utilities.
A  build-up  of methane to  a  concentration  within  the  explosive  limits  is
hazardous.  Migrating gas  can also damage  vegetation surrounding a sludge
landfill by excluding oxygen  from the root zone [25][26].  The  cover soil
can  be  used  to control  gas migration  and  odor  from  the  sludge.  Chapter
6  (Operation)  and  Chapter  8  (Completed Site) discuss in detail  the proper
placement of  cover soil.


Installation  of gas  control  facilities  is  not  necessary  if  the  site  is
isolated  and  will  remain  isolated  from inhabited structures.   However,
when inhabited  structures are  near the  landfill,  and  monitoring  wells
indicate  that  a  structure   is  threatened,  gas  migration controls  are
                                    5-40

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required.  Migration can be controlled by installing barriers to gas flow
and/or  by  collecting and  venting  the gas.   Gas  control  techniques can
generally be classified into permeable and impermeable methods.
          5.8.2.1  Permeable Methods
Permeable methods (Figure 5-15) usually entail  installing a gravel-filled
trench outside the  filled  area.   The trench intercepts migrating gas  and
vents  it  into the  atmosphere.    A  forced  vacuum extraction  system  in
trenches or in wells is sometimes appropriate.
                              FIGURE 5-15

                PERMEABLE METHOD OF GAS MIGRATION CONTROL
                                      _- SLOPE,
         5.8.2.2  Impermeable Methods
Placing a barrier  of  very low permeability material  around the  perimeter
of  the landfill  minimizes lateral  gas migration.  The movement  of  gas
through  soils  can  be  controlled  by  using  materials   that   are  more
impermeable than the surrounding soil.


The most  common material   used  for construction of  gas  barriers is com-
pacted clay.  A clay  layer approximately 2 ft  (0.6  m)  thick is probably
adequate (if it can be  constructed that  thin).   Often a thicker layer  is
required  in  order  to    ensure  an  adequate  seal   if  the  sides!ope exceeds
                                   5-41

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2H:1V.  To be effective, the  clay  layer  must be continuous; it cannot  be
penetrated.  The clay liner should be constructed as the fill  progresses,
because  prolonged  exposure  to air  will  dry  the clay  and cause  it  to
crack.    Synthetic  membranes  may  be   considered   for  the   control   of
migrating  gas  but  their effectiveness  has  not  been  established.  PVC  is
thought to be the most effective.
          5.8.2.3  Gas Extraction Systems


An  effective method  of  gas  control  in  refuse  landfills  involves  the
placement of an impermeable barrier combined with a gas extraction  system
via  strategically  located forced exhaust  vents.   However,  such systems
are  not  suitable  for sludge landfills  because  the  high moisture content
typically found  in sludge does  not permit  gas movement  and  sludge can
enter and clog the evacuation pipes.
A few gas recovery  systems  have been installed at large refuse landfills
to recover  methane  gas.  Gas  recovery  has not been  attempted  at  sludge
landfills and  is  probably not  feasible  at  this time; to  be viable, the
landfill must  be  very  large;  e.g.,  more than 5,000,000 tons  (450,000,000
Mg) for  a  refuse  landfill.   Sludge landfills  are  normally much smaller
than this.
5.9  Storm Water Management
All upland drainage should be collected and directed around the  landfill.
Drainage may be  channeled  through  the landfill  via an enclosed  pipe,  but
only  if  absolutely necessary.   The  drainage  channels  may be constructed
of  earth  (Figure  5-16),  corrugated  metal  pipe  (CMP)   (Figure  5-17),
gunite-lined  earthen  ditches,   or  stone-lined   ditches   (Figure  5-18).
If  the  access  or  on-site  roads of  the  landfill  are  paved,  they  may  be
used to channel  drainage across a  landfill.   It is  important  to  note  that
the  dimensions  shown  are  representative.    Actual  dimensions  for   con-
structing  drainage  structures  should be based on on-site investigations
of  runoff potential.
On  the sludge  landfill   itself,  all  active  and  completed  site  working
areas  should  be properly  graded.   The  surface grade  should  be  greater
than 2% to  promote  runoff and inhibit ponding of  precipitation, but  less
than  5%  to  reduce  flow velocities  and  minimize  soil   erosion.     If
necessary,  siltation ponds  should  be constructed to  settle  the solids
contained   in  the  runoff  from  the  site.    Straw  bales,   berms,   and
vegetation  may  supplement ponds or  be  used  in  conjunction  with them  to
                                    5-42

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            FIGURE 5-16

      EARTHEN  DRAINAGE CHANNEL
           VARIES
           2M MAX
NATURAL
GROUND
                                                   1/2 OR 2
                                                   SLOPE
                                           VARIES
                                            l' MIN.
              FIGURE  5-17

        CMP  DRAINAGE  CHANNEL
                    VARIES
                    18" MIN.
                           ^ CMP CHANNEL
NATURAL GROUND
                 5-43

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                               FIGURE  5-18

                         STONE  DRAINAGE  CHANNELS
                                              SOD ENTIRE WIDTH
                                SODDED WATERWAY
                                    W
                                                    4-12 STONE
                              WATERWAY WITH STONE
                                  CENTER DRAIN
control  runoff and  siltation  on the  site.   Since  the  location  of  fil]
areas  is  constantly changing,  portable drainage  structures may  be  more
economical than permanent  facilities.
5.10  Access Roads
As a  minimum,  a permanent  road should  be  provided from  the  public  road
system to the  site.   For  larger landfills, the roadway should be 20 to 24
ft (6 to 7  m)  wide for two-way traffic.  For smaller  operations  a 15 ft
(5 m) wide  road  can  suffice.   As a minimum, the roadway should be  gravel-
surfaced  in order  to provide  access  regardless  of  weather  conditions.
Grades  should  not  exceed equipment  limitations.   For  loaded  vehicles,
most  uphill  grades  should be  less  than 7% and downhill  grades  less  than
10%.
                                    5-44

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Temporary  roads are used to deliver  the  sludge to the working  area from
the  permanent  road  system.    Temporary  roads  may  be  constructed  by
compacting  the natural  soil  present and  by  controlling  drainage,  or  by
topping  them  with  a  layer of  gravel,  crushed  stone,  cinders,  crushed
concrete,  mortar,  bricks,  lime,  cement,   or  asphalt  binders to  make the
roads more  serviceable.
5.11   Other  Design  Features


     5.11.1   Soil Availability


The  quantity and  adequacy of on-site soil  for use as  a  bulking  agent and
for  covering sludge will  have  been  determined during the  site  selection
process.   However,  the  logistics of soil  excavation,  stockpiling,  and
consumption  are  more thoroughly evaluated during design.   Excavation and
stockpiling  of soil must be closely  coordinated with  soil  use  for the
following  reasons:
    1.  Soil  determined  to be suitable for use  and  readily  excavated may
        be  located  in selected  areas  of the  site.   The  excavation  plan
        should  designate  that  these  areas  be  excavated  before filling has
        proceeded atop them.

    2.  Accelerated  excavating  programs  may be  desirable  during  warm
        weather  to  prevent the  need  to  excavate frozen soil  during  cold
        weather.

    3.  Soil  stockpiles   should  be  located  so  that runoff  will   not  be
        directed  into  future  adjacent  excavations  and/or sludge  filling
        areas and to minimize  erosion.
     5.11.2  Special  Working Areas


Special working areas  should be  designated  on  the  site  plan  for inclement
weather  or other  contingency  situations.   Access  roads  to these  areas
should  be of  all-weather  construction  and  the  area  kept  grubbed  and
graded.  Arrangements  for  special working areas  may  include  locating such
areas closer to the  landfill entrance  gate  (see  Figure  5-19).
     5.11.3  Buildings and Structures


At  larger sludge  landfills or  where climates  are  extreme,  a  building
should  be provided  for  office  space  and  employee  facilities.    Since
                                   5-45

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                              FIGURE  5-19

                          SPECIAL  WORKING AREA
                               V
                                   DRY WEATHER OPERATIONAL
                                         AREA
                        PUBLIC  ROAD
sludge  landfills  operate   year  round,  regardless  of  weather,   some
protection  from  the   elements   should  be  provided  for  the  employees.
Sanitary  facilities  should  be  provided  for  both  landfill  and  hauling
personnel.   At  a few of  the  largest  landfills,  a building  might  be
provided  for  equipment storage  and  maintenance.   At smaller  landfills,
buildings cannot be justified,  but trailers  may be warranted.
Buildings  on  sites  that  will
temporary, mobile  structures.
should  consider  gas  movement
decomposing  sludge.
be  used  for  less  than  10 years  can  be
The design and  location  of all  structures
 and  differential   settlement  caused  by
Scales  are  seldom used  at  sludge  landfills.    Normally,  a  relatively
accurate  estimate of  fill  quantities  is available  from  the  wastewater
treatment  plant(s) that  generate the sludge.
                                    5-46

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     5.11.4  Utilities
Larger  landfills  should  have  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 electric generator may  be  used  instead of  having  power
lines run into the site.
Water  should  be available  for  drinking, dust  control,  washing mud  from
haul  vehicles before  entering  the  public  road,  and  employee  sanitary
facilities.  A sewer line may be desirable,  especially at  large sites  and
at  those  where  leachate  is collected  and  treated  with  domestic  waste-
water.    Telephone  or  radio  communications  may  be  necessary   since
accidents or  spills can  occur that  necessitate the ability to  respond  to
call s for assistance.
     5.11.5  Fencing
Access to landfills  should  be limited to one  or  two entrances that  have
gates that can  be  locked  when the site  is  unattended.   Depending on  the
topography and  vegetation on  the  site and adjoining  areas,  entrance  gates
may suffice to  prevent  unauthorized vehicular access.   At  some sites  it
is desirable  to construct  periphery fences to keep out any  trespassers
and animals, which is an especially  important  consideration.
Fencing requirements will be greatly  influenced by the  relative  isolation
of the  site.   Sites  close  to  housing  developments  may  require  fencing
to keep  out  children  and to  provide a  visual  screen  for  the  landfill.
Landfills that are  in  relatively  isolated  rural  areas may require  a  less
sophisticated type  of  fencing  or  only fencing at  the entrance  and other
places to keep out  unauthorized vehicles.
If vandalism  and  trespassing  are to be  discouraged,  a 6-ft  (1.8-m)  high
chain link fence  topped  with  a  barbed wire  guard is desirable  (although
expensive).  A wood fence or  a  hedge may be  used to screen the  operation
from  view.   A 4-ft  (1.2-m)  high barbed  wire fence will  keep cattle  or
sheep off the site.  Keeping trespassers and  ajiimals off  sludge  landfills
is more important than for refuse landfills because the sludge may  not  be
sufficiently stable to support their weight.


If the sludge is being disposed  of  at  a  refuse landfill the  fencing  will
also contain litter to some degree.
                                    5-47

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     5.11.6  Lighting


If  dumping  operations  occur  at  night,   portable  lighting   should   be
prpvided at the operating  area.   Alternatively, 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  landfill  has structures  (employee  facilities, administrative  of-
fices, equipment repair or storage sheds,  etc.), or  if there  is  an  access
road in continuous  use, permanent security lighting  might  be  desirable.


     5.11.7  Wash Rack
For landfills  where  operational  procedures call  for  frequent contact  of
equipment  with the  sludge,  a  cleaning  program  should  be  implemented.
Portable steam cleaning  units  or high  pressure  washers may  be  used.  A
curbed wash  pad and  collection  basin  may be  constructed  to collect  and
contain  contaminated  wash water.   The contaminated  water  may be  either
pumped to  a  septic  tank/soil   absorption system  or dispersed  with  the
sludge.   The  washing  facility  should be  used  to  clean  mud  from  haul
vehicles, to keep sludge  and mud off the  highway.
5.12  References

1.  Proposed Classification Criteria for Solid Waste Disposal  Facilities.
    Part  II.   U.S. Environmental  Protection Agency.   Federal Register.
    February 6, 1978.

2.  Draft  Environmental  Impact  Statement,  Appendices,  Proposed  Regula-
    tion, Criteria for Classification of Solid Waste Disposal  Facilities.
    Office of  Solid  Waste, U.S. Environmental Protection  Agency.   April
    1978.

3.  Portland  Cement  Association.    PCA Soil  Primer.    Portland   Cement
    Association, Chicago,  IL.   1962.

4.  Brunner, D. R. and D. J. Keller.  Sanitary Landfill Design and  Opera-
    tion.   U.S.  Environmental  Protection  Agency.  Report  No. SW-65ts.
    1972.

5.  SCS Engineers.  Selection  and Monitoring  of  Sewage Sludge  Burial  Case
    Study Sites.
                                    5-48

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6.  Fuller,  W.  H.  and  N.  Korte.   Attenuation  Mechanisms  of Pollutants
    Through  Soils.    In:    Gas and  Leachate from  Landfills, Formation,
    Collection, and Treatment.  Report No. EPA 600/9-76-004.   1976.

7.  Farquhar,  G.  J. and F.  A. Rovers.   Leachate  Attenuation in Undis-
    turbed  and  Remolded Soils.    In:   Gas  and  Leachate  from Landfills
    Formation,  Collection,  and Treatment.   Report  No.  EPA 600/9-76-004.
    1976.

8.  Farquhar, G. J.  Leachate  Treatment  by Soil  Methods.  J_n:  Management
    of Gas  and  Leachate in  Landfills.   Proceedings  of  the Third Annual
    Municipal  Solid Waste  Research  Symposium.    Municipal  Environmental
    Research  Laboratory,  U.S.  Environmental  Protection Agency.   Report
    No. EPA 600/9-77-026.  September  1977.

9.  Roulier,  M.  H.   Attenuation  of  Leachate  Pollutants by  Soils.    In:
    Management  of  Gas  and   Leachate  in  Landfills.   Proceedings  of  the
    Third  Annual  Municipal   Solid Waste  Research  Symposium.   Municipal
    Environmental   Research  Laboratory,  U.S.   Environmental  Protection
    Agency.  Report No. EPA  600/9-77-026.  September  1977.

10. Griffin, R. A.  and  N. F. Shimp.   Leachate Migration Through  Selected
    Clays.   In:   Gas  and  Leachate from Landfills,  Formation,  Collection,
    and Treatment.  Report No.  EPA 600/9-76-004.  1976.

11. Process  Design  Manual  for  Land  Treatment  of Wastewater.   U.S.    En-
    vironmental Protection  Agency.   Technology  Transfer.  Report No.  EPA
    625/1-77-008.   1977.

12. Block,  C.  A.  (ed.)   Methods  of  Soil  Analysis.   American Society of
    Agronomy, Madison,  WI.   1965.


13. Soil   Conservation  Service.    Soil   Survey   Laboratory  Methods   and
    Procedures  for  Collecting  Soil  Samples.   Soil  Survey  Investigations
    Report  1   (Revised).    Washington,   D.C.    U.S.  Government   Printing
    Office.  1965.

14. Walsh,  L. M. and J. D. Beaton (eds.)   Soil Testing and  Plant  Analysis
    (Revised).  Soil Science Society  of America, Madison, WI.  1973.

15. American  Colloid  Company.   Use  of  Bentonite  as  a  Soil  Sealant  for
    Leachate Control in Sanitary  Landfills,  Skokie, IL.  1975.

16. Haxo, H.E., Jr.  Assessing Synthetic  and Admixed Materials for Lining
    Landfills:   Formation,  Collection,   and Treatment.    In:    Gas   and
    Leachate from Landfills.  Report  No.  EPA 600/9-76-004.  1976.

17. Haxo,   H.E.,  Jr.    Evaluation  of Selected  Liners  When   Exposed  to
    Hazardous  Wastes.    In:     Proceedings  of  Hazardous Waste  Research
    Symposium, Tuscon, AZ.   Report No. EPA 600/9-76-015.  1976.
                                   5-49

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18. Geswein, A.J.  Liners for Land  Disposal  Sites  -  An Assessment.  U.S.
    Environmental Protection Agency.  Report No. SW-137.  1975.

19. Gulf  South   Research   Institute.     Preventing   Landfill   Leachate
    Contamination  of  Water.    U.S.  Environmental   Protection  Agency.
    Report No. EPA 670/2-73-021.  1973.

20. Haxo,  H.E.,   Jr.    Compatibility  of  Liners  with  Leachates.    In:
    Management of  Gas  and Leachate  from Landfills.    Proceedings  of ~th~e
    Third Annual  Municipal   Solid  Waste  Research  Symposium.   Municipal
    Environmental  Research  Laboratory,  U.S.  Environmental  Protection
    Agency.   Report No. EPA 600/9-77-026.

21. Haxo, H.E., Jr., R.S. Haxo,  and  R.M. White.  Liner Materials Exposed
    to  Hazardous  and  Toxic  Sludges,  First  Interim  Report.   Municipal
    Environmental  Research  Laboratory,  U.S.  Environmental  Protection
    Agency.   Report No. EPA 600/2-77-081.  June 1977.

22. Chi an, E.S.K. and  F.  DeWalle.   Sanitary Landfill  Leachates and Their
    Treatment.    Journal   of  the  Environmental  Engineering  Division.
    Volume 102, No. EE2.  April  1976.

23. Pohland,  F.G.     Landfill   Management   with   Leachate   Recycle  and
    Treatment:   An  Overview.    In:    Gas  and  Leachate  from  Landfills.
    Report No. EPA 600/9-76-004.  1976.

24. Clark, J.W. and W. Viessman, Jr.  Water Supply and Pollution Control.
    International Textbook Co.,  Scranton, PA.   1965.

25. Flower,  F.B.   Case History  of  Landfill Gas Movement  Through Soils.
    In:  Gas  and  Leachate From  Landfills.   Report No. EPA 600/9-76-004.
    T976.

26. Flower,  F.B.,  E.A.  Leone,  E.F.  Gilman,  and J.J.  Arthur.   Vegetation
    Kills in Landfill  Environs.   In:   Management of  Gas  and  Leachate in
    Landfills.   Proceedings of  tn~e Third  Annual  Municipal  Solid  Waste
    Research  Symposium.    Municipal  Environmental   Protection  Agency.
    Report No. EPA 600/9-77-026.  September 1977.
                                    5-50

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                                CHAPTER  6

                                OPERATION
6.1  Purpose and Scope


The purpose of  this  chapter is to introduce an approach  for  implementing
the design plans into an  effective sludge  landfill  operation.   The  opera-
tion of  a  sludge  landfill can be viewed  as  an ongoing construction  pro-
ject.   As  with any  construction project,  it  must  proceed  according  to
detailed plans.  Unlike conventional construction,  however, the operating
parameters  of  a   sludge  landfill  are  often  changing  and  may require
innovative  alterations  and  contingency  plans.  An  effective  operation
requires a detailed  operational  plan and  a choice  of  equipment  compatible
with the sludge characteristics,  the site  conditions,  and  the  landfill ing
method.
For the purposes of this  chapter, the  site  operation  may  be  viewed  in  two
parts:  the  first  part concerns operational procedures that  are  specific
to the  landfill ing method; the  second  part concerns  general  operational
procedures that are independent  of the  landfill ing method.
6.2 Method-Specific Operational Procedures


Procedures dependent on the  landfill ing method  include:
    1.  Site preparation
    2.  Sludge unloading
    3.  Sludge handling and covering


Because these  procedures  vary for each  landfill ing  method,  they will  be
discussed  as  functions  of the landfill ing  methods  introduced in Chapter
3.

      6.2.1  Sludge-Only Trench


For  sludge-only  trenches,  subsurface  excavation  is  required   so   that
sludge  can be placed  entirely below  the  original  ground  surface.    In
trench  applications, the  sludge  is   usually  dumped  directly  into  the
trench from haul  vehicles.  Soil  is  not  used  as  a  sludge bulking agent.
Soil  is used as cover, usually in a single, final application.
                                   6-1

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Two  kinds  of  sludge-only trenches  have  been  identified  including  (1)
narrow trench and  (2) wide trench.  Narrow trenches  have widths less than
10 ft  (3.0  m).   Wide  trenches have  widths greater  than  10  ft  (3.0  m).
Chapter 3 (Sludge Characteristics and Landfill ing Methods) and Chapter 5
(Design) should be consulted  for  specific  design criteria.
         6.2.1.1  Site Preparation

Site  preparation  includes  all  tasks  which  are  required  prior  to  the
receipt  of sludge.   Tasks  include  clearing  and  grubbing, grading  the
site, constructing access roads,  and  excavating  trenches.
The  location of  access  roads  depends  on  the  topography  and  the  land
utilization  rate.   Narrow trenches  use  land  rapidly  and require  more
extensive  road  construction.    Wider  and/or  longer  trenches may  require
vehicle access roads along  both  sides  of the  trench.


Prior to grading, the  area  should  be  cleared  and  grubbed.  Grading should
be done on the site  (1)  to  control runoff and  (2) to  provide  grades com-
patible with equipment  to be  used. For  example,  drag  lines and  trenching
machines operate  more  efficiently  on  level  surfaces.   Narrow trenches may
require less grading due  to their  applicability to hilly terrain.
Progressive  trench construction  is the  most  efficient  procedure  for  a
narrow trench  operation.   The initial  trench  is  constructed  using appro-
ri m n -»4-^s j-i A-. I i 4 r^m f\**+  -\ »^^l  4- L%v\ r«rt 4 1  ^N^^k<"»i/«  ill r% 4 1 r\s4  -»T ^\ w»rt  -^Irtrt 1 Onfl "^ h  Ol  t M O
                                                              ;d  to ground
	  ...    _  	  ,..._.  ...  ..._ ......... 	 ..  ....  	   and  used to
prevent  runoff  from  entering  the  trench.    Succeeding  trenches  are
constructed  parallel  to the  initial  trench.   The trench  dimensions  and
the distance between the trenches  should  follow design  specificiations.
narrow trench  operation.   The initial  trench  is  constructed  us
priate equipment  and the soil either  (1)  piled  along  the leng
trench, or  (2)  stockpiled  in a designated  area,  or (3)  graded
level.  Soil is often piled  on the uphill  side of the  trench  ai
nrp\/pnt  rimn-ff  fVnm  pntprinn  thp  tremrh.    ^nrrppHinn  trp
Trenches may  require  dikes positioned intermittently  across  the  width of
the trench, especially  if  such  trenches  are long.  The dikes should be of
sufficient  height  to  contain the  sludge and attendant  liquids  and allow
proper  trench filling and  covering.   Equipment  may be used  inside wide
trenches to construct dikes.
On-going site  preparation  is  critical  for proper execution of a trenching
operation.   Depending  on  the quantity  of  sludge received,  a  designated
trench  volume  should   always  be  maintained   in   advance   of  filling
operations.  Ideally, trenches should  be prepared at least one week ahead
of the current landfill ing  operation.
                                    6-2

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         6.2.1.2  Sludge Unloading


Signs  should  be  placed to designate which  trench is in  use.   Sludge  is
usually  unloaded  from haul  vehicles via  direct  dumping.   However, metal
extension chutes  or  pumping  may  also be  employed.   If  direct dumping  is
employed, an  appropriately  sized area  should  be prepared at  the lip  of
the trench  so that  transport vehicles  can  safely back up to the trench
edge for unloading.  Sludge  unloading can occur  along the length of  both
sides  of the  trench  if necessary.   The  entire  unloading  area should  be
kept clear  of discharged  sludge and periodically regraded  to facilitate
safe unloading operations.
         6.2.1.3  Sludge Handling and Covering
Sludge should be uniformly distributed throughout the trench.  Otherwise,
depressions  that  could cause  ponding are  likely to  occur as  the fill
settles.  Narrow and wide trenches should be filled only to a level where
a  sludge  overflow will  not  occur  due  to  displacement  during  cover
application.  Markers  on  trench  sidewalls can  be  used  for this purpose.
The  appropriate  level  for  sludge  filling  can  best  be  established  via
experimentation using test loads.
Concurrent excavation, filling,  and  covering  of trenches is a sequential
operation that  requires  a coordination of  effort.   When  the  sludge has
filled  the  trench  to the  designated  level,  cover  material   should  be
applied  using  either soil  freshly excavated  from  a  parallel  trench  or
soil  stockpiled during excavation  of the  trench being  filled.  Depending
upon the solids content of the  sludge  and  the width of the trench, cover
application should proceed as follows:


     1.  If the sludge has a solids  content from  15 to 20%, the width of
         the trench  should be 2  or 3 ft (0.6  to 0.9 m).   Cover applica-
         tion should  be  via  equipment based  on  solid  ground  adjacent to
         the  trench.   Covering  equipment  may  include  a backhoe  with
         loader, excavator, or trenching machine.

     2.  If the sludge has a solids  content from  20 to 28%, the width of
         the trench  is technically unlimited.   However,  it is limited by
         the  requirement  that  cover be  applied  by  equipment  based  on
         solid  ground.   Covering  equipment  may  include a backhoe  with
         loader, excavator, track  loader, or dragline.
                                    6-3

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     3.  If the sludge has a solids content of 28% or above, the width of
         the trench is unlimited.  Cover application can be via equipment
         which  proceeds  out  over  the  trench  pushing  cover over  the
         sludge.  Covering equipment usually is a track dozer.


In  all  cases,  initial  layers  of  cover should  be carefully  applied to
minimize sludge displacement.   The final  cover should  extend  at  least 1
ft  (0.3 m)  above  the  ground  surface (and preferably more).   As settling
occurs,  additional  soil  cover  may   have  to  be  applied   to  prevent
depressions  and  ponding.    Experience has  shown  that  the majority of
settlement occurs within 6 to 9 months.  After it has settled, the entire
trenched  area  should  be  graded.   The  trench  areas  should be sloped to
minimize  infiltration and  prevent  ponding.   If practical, an  impermeable
cover  (clay,  etc.)  should  be  applied  to  reduce  infiltration.    Final
covers  may  include 1  to 2  ft  (0.3 to 0.6 m)  of topsoil  and suitable
vegetation such as grasses.  A  sludge  soil  mixture of  2 to 10 parts  soil
to  1 part sludge  can be  used to enrich  the  soil if necessary.
         6.2.1.4  Operational Schematics


The  preceding  information  has  been included  to generally  describe the
operation  of trenches.    Figures  6-1  through  6-4  illustrate   specific
trench operations.


     6.2.2  Sludge-Only Area Fill


For  sludge-only  area  fills, sludge  is  usually placed above the  original
ground surface.   In area  fill  applications,  soil  is  usually mixed with
the  sludge  as  a bulking  agent.   Cover  may  be used  in  both interim and
final applications.


Three  kinds of  sludge-only area fills  have  been  defined  including (1)
area fill mound, (2) area  fill layer, and  (3)  diked containment.   In area
fill  mound  operations,  sludge/soil  mixtures  are  usually  stacked into
piles  approximately 6  ft  (1.8 m)  high.    In  area  fill  layer operations,
sludge/soil mixtures are spread  evenly  in  layers 0.5 to 3 ft  (0.15  to 0.9
m)  thick.    In  diked  containment  operations,  sludge  (with  or  without
bulking  soil)  is dumped  into  pits contained  by  dikes  constructed  above
the  ground  surface.  Chapters 3  and  5  should  be  consulted  for  specific
design criteria.
                                    6-4

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                             FIGURE 6-1

                       NARROW TRENCH OPERATION
A  sludge  landfill  in Paris, Maine  receives  55 wet tons  (50  Mg) per
day of  stabilized  14%  solids  sludge.   Trenches at  the  site are 6 ft
(1.8 m) wide and 6 to 8 ft  (1.8 to 2.4 m) deep.  From 4 to  10 ft  (1.2
to  3.0 m)  of  undisturbed  ground  is  maintained   between  trenches.
Sludge  is  off-loaded directly into trenches  from  load-lugger  trucks
with arm-extended  dump  buckets.   Unloading  occurs  either at  the end
of the trench or along  its  length.  The  sludge is  filled to within 2
ft  (0.6  m) of  the  surface and  allowed  to  settle for  several  days
before  the trench is  covered.    This  is  necessary because  the low
solids sludge will not  support cover  initially.   Since the sludge is
stabilized, odor is  not a serious  problem.   In warm weather, lime is
applied over the surface of the sludge layer.
While  the  sludge  unloading  is  occurring  in  one  location,  trench
excavation  and  sludge covering  are  being conducted  in  other areas.
Sludge-filled  trenches  are  covered  with  soil  taken  from  newly
excavated trenches.  The sludge-filled trench is covered carefully  in
order  to  prevent  the  displacement  of   sludge  by  the  soil  cover.
Covering  the si udge-filled  trench  in  this  manner  produces  rugged
mounds  5 to  6  ft  (1.5  to  1.8 m)  high  throughout  the area.   The
trenches  are then allowed  to  settle  for several  months  before  the
area is  regraded to a smooth surface.
                                 6-5

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                             FIGURE 6-2

              WIDE TRENCH OPERATION AT REFUSE LANDFILL
This trench  operation  is located on  a  100-acre (40-ha) refuse  land-
fill site near Greenville, Michigan.  A  single  wide  trench 300 ft  (90
m)  long, 30 ft (9 m) wide, and 15 ft  (4.6 m) deep  is  employed to dis-
pose  of  approximately   25  yd3  (19  m3)  of anaerobically  digested
and dewatered sludge each  day.   The  trench  is  constructed using  one
excavator equipped  with  a  36 in. (91  cm)  wide  bucket.   Dump trucks
unload the 15% solids sludge at  the  edge  of the trench, starting  at
one end and moving forward as the trench is  filled.
The trench  filling operation takes  approximately 6 to  8 months,  in
which time the  sludge  dewaters  through the  sandy  soil.   By the  time
the trench is totally  filled, the old  sludge at one  end  of  the  trench
is  dry  enough to  be  removed by  an  excavator, mixed  with  soil,  and
applied as cover  on the  refuse  landfill.   This progression of  sludge
filling and  subsequent removal  enables the trenching operation to  be
confined  to  a  small   area.   The  sludge/soil  mixture  increases  the
organic  content  of  the  soil   and   enhances  vegetative  growth  on
completed fill  areas  at  the refuse landfill.  The sandy soil   at  the
site drains  well  and  hence the  operation  is effective even with  the
relatively high rainfall common  in the  area.
                                  6-6

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                             FIGURE  6-3

                 WIDE TRENCH OPERATION WITH  DRAGLINE
A privately  operated  site  near Cleveland, Ohio receives 450 wet  tons
(408 Mg)  of  sludge daily  from  four  sources.  Most  of  the sludge  is
digested  and/or  chemically treated,  and averages 20% solids.   Sludge
is  unloaded  from haul  vehicles  directly into trenches.   Because  of
its  consistency,  the  sludge flows throughout  the  trench and  spreads
out  evenly.
The trenches are excavated by a dragline with  a 50 ft  (15 m)  boom  and
4.5 yd3  (3.4  m3)  bucket.  They  are 40 ft  (12 m) wide,  700 ft (210
m) long, and 5 to 6 ft (1.5 to 1.8 m) deep.  Sludge  is deposited to  a
depth of 3 ft (0.9 m) and  is then  covered  with 5 ft  (1.5 m)  of  soil,
resulting in a mound that  ranges from 2 to  3  ft  (0.6 to 0.9  m)  above
grade.    Cover  for  sludge  filled  trenches  is  supplied   by  spoil
material generated  from  excavation of the  parallel  trench.   Because
of the low solids content, the cover  is  applied  by the dragline with
the  bucket  initially  at  a  minimum  height.    This  ensures  minimum
displacement of the  sludge by  cover material.   After the first  layer
of cover is applied, the  dragline  applies  the remaining cover from  a
greater  height.    The  trenches   are  allowed  to   settle   before  a
bulldozer is  used  to final grade  the area.   Initial  designs called
for a wider  trench  but experience  indicated  that  the dragline  would
have to be moved excessively.  Accordingly, the  width was  reduced to
40 ft (12 m).
                                 6-7

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                             FIGURE 6-4

              WIDE TRENCH OPERATION WITH  INTERIOR DIKES
A privately  operated  sludge landfill  in Cleveland, Ohio receives  250
wet tons  (226 Mg)  of  sludge daily from  several  sources.  The  sludge
is  digested  and/or  chemically  treated  and  has  an  average  solids
content  of 20%.   Trenches  are 40  ft  (12 rn)  deep  and  700  ft  (213  m)
long.  Dikes are placed  at intervals  within the trench  to facilitate
phased filling and covering.   The  dikes are placed at  intervals  that
ensure frequent cover applications.   Sludge  is  unloaded  directly  into
trenches  and  spreads  out  evenly throughout  the contained  area.   Two
to  3  ft   (0.6  to  0.9 m)  of cover  material   is  applied by  front-end
loaders  and  excavators  excavating  a parallel  trench. Completed  areas
are  regraded  from  6  to  9  months  after  cover  is  applied  and  subse-
quently  reseeded with grass.
                                  6-8

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         6.2.2.1  Area  Fill  Mounds
Area  fill  mounds  may be employed  in  a  variety of topographies.   Usually
such  operations  are conducted on level  ground.   However,  mound landfills
are also well  suited  to  construction  against  a hillside which can provide
containment  on one  or more  sides.
              6.2.2.1.1   Site  Preparation
The first  step  is  to  prepare the subgrade.  Depending  on  design specifi-
cations  this  may include underdrains  and/or liners for leachate  collec-
tion.  Due to the  large amount  of  soil  required for proper  operation  of
area  fill  mounds,  emphasis  should  be  placed on  securing  sufficient  soil
material.   Accordingly,  the fill should  be  confined  to a  small  area  and
proceed  vertically  to  the  maximum extent possible.  This  will  reduce  the
areal  extent  of the  landfill  and  consequently  reduce  erosion  and  silt-
laden  runoff  from  denuded  areas,  provided the  slope does  not  become
excessive.
The  excavation  can be  carried  out  in  phases  to  take  advantage of  soil
differences.   Any  soil  that has  to be  stockpiled  for  use  as  a  sludge
bulking  agent should  be placed  in compacted, sloping piles.   To  keep the
soil dry, piles may be  covered  with  tarpaulins  and the  tarpaulins secured
using  old  rubber tires.   Wet  soils,  because  they  are  not  suitable  for
sludge bulking, should  not  be stockpiled.   Soil  that is  stockpiled  should
be  placed  as  close as  possible to points of eventual  use and access  to
stockpiles provided.
              6.2.2.1.2  Sludge Unloading
The  sludge  may be unloaded  either  in the filling  area  or in  the  desig-
nated  unloading  and  mixing  area  near the bulking  agent stockpile.   The
unloading area should  be clean and  relatively  level  for safe  passage  of
trucks.   Haul vehicles  should not  drive over  completed sludge  filling
areas.
              6.2.2.1.3  Sludge Handling  and  Covering


Operational procedures should be  provided to  specify what  soils  are  to  be
mixed with sludge, where they are  to  be obtained, and  how they  are  to  be
mixed and/or placed over the sludge.  The amount  of material  required  for
each function is determined by site design  specifications  which  take into
account  soil  and  sludge  characteristics.   Preliminary trial  and  error
tests to determine sludge/soil  ratios  that  produce  sludge  with  appro-
priate consistencies should be attempted during  initial  operations.


                                   6-9

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Construction of area fill mounds requires that the  sludge/soil  mixture  be
relatively stable.   Sludge/soil  mounds are  generally applied in a  series
of lifts with each lift  containing  one level  of mounds.  When  completed,
the  lift  should be  covered with  a layer  of  soil   sufficient  to  safely
support on-site operating equipment.
Once the area  is  filled  to  the designated contours, the entire  fill  area
should  be  covered  with  3  to  5  ft  (0.9  to  1.5  m)  of  soil  material
(preferably impermeable  soil  such  as  clay if it is available).  The  fill
area should  then be  final  graded to  account for  future  settlement  and
promote drainage.  A  layer  of topsoil  up to  2 ft  (0.6  m)  may be used  as
final dressing and the area seeded with  grass to  prevent erosion.
         6.2.2.2  Area Fill Layer
Area  fill  layers  may also  be employed
Layer operations  consist  of a  series  of
final cover applications.
in  a  variety
sludge layers
of  topographies.
with interim  and
              6.2.2.2.1  Site Preparation
As  with  area  fill  mounds, the  first step  is  to  prepare  the  subgrade.
Again,  liners  and/or  subdrain   systems  may  be  utilized  depending  on
hydrogeological  conditions.   Fill  areas  for layer  operations  should  be
nearly level.  Although the soil  requirements of  such  operations are  less
than those  of area  fill  mounds, it may be  necessary to import  soil.   In
any case, soil stockpiles  should  be established,  both  for  use  as bulking
agents and  cover soils.  Areas  should  be  excavated  only as  they  are  used,
to  the maximum extent possible.  This will  reduce  the amount of  denuded
area subject  to erosion.
              6.2.2.2.2  Sludge  Unloading
Specific  unloading  and  sludge/soil   mixing  areas  may  be  maintained  or
sludge can  be  placed directly in the fill  area.   An effective method  in
layer operations  is  to  maintain soil  stockpiles on the  fill  area  itself.
Bulldozers  then  mix and  layer  the  sludge  in one  operation.    Again,
storage areas  should be  located  away  from traffic.
                                    6-10

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              6.2.2.2.3  Sludge  Handling  and  Covering


In  general,  design  specifications  based on  sludge characteristics  will
give  some  indication  of  the  required  amounts  of  bulking  agent.   Neverthe-
less,  it is always advisable to  conduct  preliminary trial  and error  tests
to  determine  bulking  ratios  appropriate for supporting  equipment.    The
depth  of interim  and final  cover can  also  be determined  in this  manner.
Again, when the  area has been filled  to  the  contours established in  the
design, a  final  cover of 2 to 4 ft  (0.6  to  1.2  m)  should be applied  and
the  area seeded.   It  will  be  necessary  to  regrade the  site  in 6 to  12
months, and possibly  thereafter  as the fill area  settles  and compacts.


         6.2.2.3  Diked  Containment
Diked  containments  are  essentially  aboveground wide  trenches  and,   as
such,  use  similar  procedures  and equipment.  The design and  construction
of dikes,  however, is more complex and  is  usually not warranted.  Only  in
cases  where  high  groundwater  tables,  bedrock and/or low solids,  rule out
more conventional methods is  their expense  justified.
              6.2.2.3.1  Site Preparation


The first step  in  preparing  the  site  for diked containment is to  provide
a  suitable  subgrade  or a  liner,  if  necessary.    Next,  soil  should  be
imported  from  other  areas  if needed.   This  soil  should  be relatively
impermeable.    The dike  base  is  then  constructed   maintaining  design
dimensions  and  slopes  (generally from  2H:1V  to  3H:1V  for  sideslopes).
Succeeding  layers  are then  applied  and each  layer  compacted by  passing
equipment   over   it.     Alternatively,  the   containment   area   may   be
constructed  against  one  or more  steep sideslopes.   A ramp  should  be
provided for unloading vehicles.
              6.2.2.3.2  Sludge Unloading


Sludge may be unloaded from the top  of  the  dike or in an area designated
for  sludge/soil  mixing.   Slopes  and  grades of  access  roads  should be
maintained to design  specifications.    Provisions  should  be  made  for
inclement weather (e.g., stockpiled  soil  kept dry).
                                   6-11

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              6.2.2.3.2  Sludge Handling and Covering
The  containment  area  is  filled  with   sludge  in  layers,  usually with
interim  soil   or  gravel   cover  provided   at   predetermined  heights.
Draglines  are  frequently  used  to apply  interim  and  final  cover.   The
final cover  should be 3 to  5 ft  (0.9  to 1.5  m)  thick.   Ideally, this
could consist of  a relatively impermeable layer of clay  about  1  to 3 ft
(0.3 to 0.9  m)  thick, followed  by 2  ft  (0.6 m)  of topsoil  [1].   It is
usually necessary  to reapply the  final  cover  after  initial settlement has
occurred.   If  additional  settlement  causes  depressions, the  site will
have  to  be   regraded.    The  area  should  be  seeded  with  a  suitable
vegetative cover.


         6.2.2.4   Operational Schematics
The  preceding  information  has  been included  to generally  describe the
operation of sludge-only  area  fills.   Figures 6-5 through 6-8 illustrate
specific area fill operations.
     6.2.3  Codisposal
In  codisposal  operations,  sludge is  received  at  a  landfill  receiving
typical municipal  refuse.   Two kinds  of  codisposal  operations have  been
identified  including  (1)  sludge/refuse  mixture  and   (2)   sludge/soil
mixture.   For  sludge/refuse  mixtures,   sludge  is  mixed  directly  with
refuse  and  landfilled at  the working  face.   For  sludge/soil mixtures,
sludge  is mixed  with soil  and used  as cover  over  completed  refuse  fill
areas.    Chapters  3 and  5  should  be  consulted  for   specific   design
criteria.

         6.2.3.1  Sludge/Refuse Mixture
Once sludge  receipt  has  begun,  every effort should  be  made to take  full
advantage  of the absorptive  capacity  of the  refuse.   Consequently,  the
sludge  should  be mixed with  the  refuse  as thoroughly  as  possible.   One
procedure  employed  calls for refuse  to  be dumped  at  the  bottom  of  the
working face, and subsequently  pushed, spread,  and compacted  by equipment
working up  the  working face.   Under these circumstances,  sludge  can  be
handled in two alternative ways.  The first way includes:
     1.  Dump the refuse at the bottom of the working  face
     2.  Dump the sludge atop the  refuse pile
     3.  Thoroughly mix the sludge and refuse
     4.  Push,  spread,  and  compact  the  sludge/refuse  mixture  up  the
         working face
                                   6-12

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                             FIGURE 6-5

                      AREA FILL MOUND OPERATION
A site in Lewiston-Auburn, Maine  receives 40 wet  tons  (36  Mg)  per  day
of  chemically treated  sludge.    The disposal  site is  an  abandoned
gravel pit with a clay liner and  underdrains for  leachate  collection.
Leachate collected at the site  is conveyed to  the treatment  plant  via
a nearby sewer interceptor.
The  sludge is unloaded  onto a  receiving  and mixing  pad  constructed
with  gravel and  crushed  stone.   A  large  covered  pile of borrowed sand
is  located near this  receiving area.   Each  10  yd^  (8  ITH)  load  of
sludge  is thoroughly  mixed with  6  yd3  (4.6 m3)  of  fine  sand.    A
loader  then  transports  the  sludge/sand  material   into the  fill  area
and  pushes and piles the material  into 6 to 8 ft  (1.8  to  2.4  m)  high
mounds.    During wet  weather,  the  mounds  slump  and they must  be
continuously  piled  and pushed by  small  track  dozer.  The  8  ft  (2.4
m) high mounds form a  lift  that  must  be  covered by  1  to 2  ft  (0.3  to
0.6  m)  of gravel  to   support  equipment.   Lifts   are  produced  to
complete  the  site,  filling  it  to its  original  grade.  The  entire fill
area  will  ultimately be  covered  with  an  impermeable layer  of clay and
graded  to  ensure proper  drainage.
                                 6-13

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                             FIGURE 6-6

                      AREA FILL LAYER OPERATION
This area fill layer operatjon  is
proximately  40 yd3  (30  m3)  of
brought to the site daily.  The
lime applied  to  it  and  is
dewatering.  A track loader
sludge ratio)  obtained  from
10 ft  (3  m)  wide, 3
layer  receives  6  in
             located  on  150  acres  (61  ha).  Ap-
             digested  and  dewatered   sludge  is
           25% solids sludge has a thin layer of
       then  left  uncovered  to  promote  further
       mixes the sludge with soil (a 3:1  soil  to
       a  stockpile,  and  applies the material  in
ft  (0.9 m)  thick layers against a  slope.   Each
 (15 cm)  of interim  cover.   A  progressive 3:1
slope is constructed from the layering operation,
In wet weather, the track dozer loses traction  and  is  unable  to  layer
the sludge  on the  slope.   For this  reason, a  separate  wet weather
area is maintained  on relatively level ground near  the entrance.  The
ground beneath the  working  face  is sloped so that
to  one  end  of the  area.    From   here  the  runoff
holding pond.  A  final  soil  cover  of 3 ft  (0.9  m)
completed  slope  and the  area is  seeded.   If   necessary,  sludge  is
disced into the soil cover to enrich the  soil prior to seeding.
                              runoff is directed
                               is  directed  to  a
                               is  applied  on the
                                  6-14

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                             FIGURE 6-7

               AREA FILL LAYER OPERATION INSIDE TRENCH
A  landfill  at  Frederick, Maryland  receives  30 wet  tons  (27 Mg)  per
day of  23%  solids sludge.  Trenches  45  ft (14 m)  wide,  20 ft  (6  m)
deep, and 200 ft  (60 m)  long are constructed with  a  scraper  and  track
dozer.  A minimum of 20 ft  (6 m) of  solid ground  is maintained  bet-
ween trenches.   Excavated material  is stockpiled  along one  length  of
the trench,  but  set  back  at  least 20 ft  (6  m)  from the  excavation
edge.
Sludge  is  unloaded  along alternate  sides  of the trench depending  on
weather.   When  wet  conditions prevail,  the  sludge is unloaded  adja-
cent  to  the stockpile.   When the weather  is dry  and  operations  of
unloading  vehicles   and   equipment  are  not  hindered,the   sludge  is
unloaded  on the  other  side.  After two  loads  have been  dumped,  a
wheel loader mixes soil  from  the  stockpile with  the sludge at 1  or  2
parts soil  to 1  part  sludge.   The sludge/soil mixture is then  pushed
downslope  toward  the center  of  the  trench.   The  operation  proceeds
alternatively on  each side of the trench.  The sludge/soil  mixture  is
covered daily with  a thin Iyer of 2  to 4
                                2  ft  (0.6
                                 (15 to  30
                                (0.6 m)  of
The trench  is  filled to within
lowed to  settle.   A  6 to 12 in
applied,  followed  by  about 2 ft
stockpiled  separately on-site  as  the trenches  are
design originally  called for  a  narrower  30  ft (9 m)
in. (5 to
m) of the
cm)  layer
top soil.
 10  cm) of soil.
 surface and al-
 of  clay is then
 The top soil  is
excavated.   The
wide trench, but
experience  indicated that  the
terms of land use and costs.
                                wider  trench  was  more  efficient  in
                                 6-15

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                             FIGURE  6-8

                     DIKED CONTAINMENT OPERATION
This  landfill  operation uses  a
disposal.
methods but
groundwater
the  sludge.
 The  municipality
 decided  to use  a diked
and bedrock in the  area
  Containment  areas  are
material   is generated  in
diked  containment design  for sludge
had  investigated  other  landfill ing
     containment  due to  the shallow
     and  the  relatively  low solids of
     constructed  into  the  side  of a
     part  by excavating the contain-
hill.  Soil
ment area with a scraper  and  a  track  dozer.   This  material  is mounded
and compacted by the dozer.   Additional  soil  is  imported as necessary
from other  areas  for  completing the  dikes  and for cover  soil  stock-
piles.  When completed, individual  diked  containment  areas are 100 ft
(30 m)  long,  40  ft (12 m)  wide, and 30  ft   (9 m)  high.   A  leachate
control  system  consisting  of a clay liner  and  leachate  collection
pipes  is then installed on  the  floor  of  the  diked  containment area.
       SOIL STOCKPILE
                                                              SOIL STOCKPILE
Each  day 200  wet  tons  (181  Mg)  of  digested,  dewatered  sludge  is
hauled  to  the site  in  large  open-top  dump trucks.   The  20%  solids
sludge  is  dumped directly  into  the diked  containment  area.   Due  to
its  liquid   nature,  individual  sludge  piles  slump considerably  and
spread  out  in  the diked  containment  area.   After the sludge reaches a
height  of  5  ft  (1.5 m),  2 ft  (6 m)  of   interim  cover material  is
applied  atop the sludge by  a  dragline.  Additional interim  cover  is
applied  over the second lift  when the  sludge reaches  a  height  of  12
ft  (3.7 m).   A  final  5 ft  (1.5 m)  layer  of final cover  is applied
over  the siudge  when  it  accumulates  to  within 3 ft  (0.9 m)  of grade.
                                  6-16

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The second method can be  accomplished  in the  following  way:
     1.  Dump the  refuse  at the  bottom  of  the  working  face
     2.  Push,  spread,  and compact  the  refuse  up  the working  face
     3.  Dump the  sludge  at the  top of  the working  face
     4.  Push  the  sludge down  the  working   face,  spreading  it   evenly
         across the  refuse
If  small  quantities  of sludge  are  received at  refuse  landfills  (i.e.,
less than 5%) it may  be desirable to confine  sludge dumping  to  a  selected
location on the working  face.   This  approach is useful  in landfills  that
are   sufficiently  large   to   ensure   that   refuse   dumping   proceeds
simultaneously along  a wide working face.
Precautions should  be  taken  to  contain  any sludge which escapes from  the
working  face.   This may be  particularly  needed for a  sludge  with a  low
solids  content.   Containment can  be achieved  either  by (1)  landfill ing
the  sludge  in a  small  depression  or (2)  constructing a  refuse  or  soil
berm at the bottom  of  the working  face.


Other  factors to  be  considered  for refuse  landfills  receiving   sludge
include  increased  odors and  the  possibility  of  a  small   increase  in
leachate generation.    Appropriate  steps  can be taken  to  control odors
including more frequent  application  of cover  and  spot  addition of  lime.


         6.2.3.2  Sludge/Soil Mixture

Another  option  for  handling sludge  at  refuse  landfills  is  mixing   the
sludge  with  soil  and  then  applying  the  mixture as cover  material  over
refuse-filled   areas.     Although  this   technically  is   not    sludge
landfill ing,  it  is a  viable  alternative,  is  particularly  useful   in
promoting vegetative growth  in  completed  fill areas,  and is performed  at
numerous refuse landfills.
The application of this sludge/soil operation may proceed follows:
     1.  Spread sludge as received uniformly over the ground surface  in a
         3 to 6 in. (8 to 15 cm) thickness in an area designated for  this
         purpose.

     2.  Disc the sludge into the soil.
                                   6-17

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     3.  Spread  lime  or masking  agent  over the  sludge/soil  mixture  for
         odor control  if necessary.

     4.  After  a period ranging  from 1  to 8  weeks time  (depending  on
         rainfall  and  climate)  scrape  up the  sludge/soil   mixture  and
         spread  it over completed  fill  areas  where vegetative growth  has
         been slow to take root.
         6.2.3.3  Operational Schematics
The  preceding  information  has  been included  to generally  describe  the
operation  of codisposal  sites.    Figures  6-9  through  6-11   illustrate
specific codisposal operations.
6.3  General Operational Procedures
Operational  factors   that   are  generally   applicable   to  all   sludge
landfill ing methods include:
     1.  Environmental control practices
     2.  Inclement weather practices
     3.  Hours of operation
     4.  Special wastes
     6.3.1  Environmental Control Practices
In many cases, environmental controls must  be  designed  and  constructed  to
lessen the  environmental  effects  of sludge landfills.  Maintaining  these
controls  is necessary to  the  landfill  operation.   Common sense  control
practices will also  help ensure an environmentally sound disposal  opera-
tion.  These environmental control  practices are  described  in  the  follow-
ing sections and outlined  in Table  6-1.
         6.3.1.1  Spillage
Enroute and on-site spillage  of  sludge must  be  cleaned  up  as  soon  as  pos-
sible.   Haul  vehicles  enroute  to  the  disposal  site  should  report  even
small spills to the operation supervisor,  so emergency  clean-up  crews can
take prompt action.   On-site  spills should be controlled  as  much  as  pos-
sible.   It  is  a  good  policy  to  have  lime  on hand at all  sludge  disposal
operations  for  spot  application  to  spills if  prompt clean-up  is  not
                                    6-18

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                              FIGURE  6-9

                    SLUDGE/REFUSE  MIXTURE  OPERATION
A  site  near Pittsburgh,  Pennsylvania receives  100  wet tons  (91  Mg)
per  day of 22%  solids sludge.   Two or three  confined areas  at  the
operating  face are  designated  for sludge disposal.   A layer of refuse
is spread  on the  ground  at  the toe of the  working face and the driver
of the  sludge  haul  vehicle  directed to  unload  the  sludge on  top  of
the  refuse  so that  the sludge is absorbed by the  refuse.   Generally,
a  few hours are  allowed  to  permit the  sludge  to  be absorbed  by  the
refuse.   More  refuse  is then piled  on  the sludge  and   a  bulldozer
mixes the  sludge with  the  refuse  at a ratio  of approximately  four
parts refuse to  one part sludge.   Any  ratio less than this  has  been
found to  cause soft  spots  in  the fill  area  and create  operational
problems.   The   mixture  is  then  pushed  up the  working  face  with
bulldozers  and  compacted.  An interim soil  cover  is applied  at  the
end  of  each working day.
The  timing of  sludge  deliveries  is  critical  since  there  must  be
sufficient refuse  available  for  operations to proceed.  Accordingly,
sludge deliveries  are timed to coincide with  refuse  deliveries,  which
occur in the morning  and  early afternoon.  The  site encounters  prob-
lems  in  wet  weather.   The 4:1  refuse  mixture is  found  to be  inade-
quate when  the  refuse  is  wet.   The  usual  solution has  been to  in-
crease refuse quantities.   During  warm weather  the site  experiences
some  odor  problems.   Masking  agents are  used  when odors are a  prob-
lem.
                                 6-19

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                             FIGURE 6-10

                  SLUDGE/REFUSE MIXTURE WITH DIKES
A  codisposal  site  at  Stafford, New  Jersey,  receives  about  TOO wet
tons (91 Mg)  of  17% solids sludge per  day at specified locations  on
the working  face.   The sludge  is  deposited at the  top of the
and allowed  to  flow down  the face into  a refuse berm
structed at  the  toe of the face.   The ratio of  refuse
generally about 4 to 5  parts  refuse to one part  sludge.
of the  day,  the  refuse  is mixed  with  the sludge and  pushed up the
working  face.    Subsequently the  mixture  is  compacted   and   cover
applied.   At times the  operation  has  had difficulty  containing the
sludge during mixing operations, but  by maintaining  suitable ratios,
the problem  has been alleviated.
        slope
that is  con-
to  sludge  is
  At the  end
This  technique enables operators  to store  refuse,  which arrives  at
the  site  in the  morning  and early  afternoon, and  coordinate  mixing
operations  with  the  sludge, which  arrives  continuously during  the
working day.   Vegetation  has  been  slow  to  take root  in completed fill
areas  because  the soil  is  sandy and  has a low  organic  content.   As  a
result  plans  are  now underway to disc  sludge into the soil
applying  final  cover.
     prior to
The  site  is  on  a coastal  plain and consequently  has  a  milder climate
than  areas  in similar latitudes.  As  a  result, the site  has  not  had
problems  with winter  operations.   However,  during  heavy rains  the
refuse  dikes can  become  water logged,  thus  reducing  the  absorptive
capacity  of  refuse.	
                                 6-20

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                              FIGURE  6-11

                         SLUDGE/SOIL  MIXTURE
A codisposal  site  near  Washington,  D.C.  uses  a  sludge/soil  mixture as
final  cover for completed  fill  areas.   The  site receives  digested,
dewatered   sludge  averaging  22%  solids  from   4 treatment  plants.
Sludge  makes  up about  10%  of  the  total  waste  received  at  the  site.
The  sludge  is dumped  in designated  areas,  spread  evenly  over the area
in a thin  layer,  and thoroughly mixed with  the soil  using  a  discing
apparatus.  Approximately one  week later, the  sludge-soil  mixture  is
scraped  up  and  a  masking agent added.   It  is then applied  over com-
pleted  areas  as a  soil  enrichener.   The mixture is  generally  1  part
sludge to 1 part soil.   It  was found that the mixture worked  well  in
enhancing vegetative  growth.
The  site  encounters some  problems,  with  the  operation  particularly
during  winter  operations  when  the  soil  is  frozen  and  discing  is
difficult.   At these  times  an  alternative  procedure,  sludge/refuse
codisposal,  is generally  used.    Other problems  that  the  site  has
encountered  are mild  odor problems.   This  is handled  by  applying
masking agents.
A stream  bisects  the site and  consequently  runoff is carefully  con-
trolled.  The stream is culverted and runoff is directed to  siltation
ponds so that discharge to the  stream can be controlled.
                                 6-21

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TABLE 6-1
ENVIRONMENTAL CONTROL PRACTICE
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6-22

-------
feasible.   The use of  haul  vehicles with baffles  on  them has  been  used
effectively to  limit  spills.
         6.3.1.2  Siltation  and  Erosion
The  presence  of silt-laden runoff  from  the site  is  often the  result  of
improper grading.   Grades  of  2 to 5% should be maintained  where feasible
to  promote  overland surface drainage, while minimizing  flow  velocities.
Denuded  areas  should be  kept  to a  minimum during  site  operation.   On-
going  construction  and  maintenance  of  sediment  control  devices  (e.g.,
grass  waterways,  diversion ditches, rip-rap, sediment basins)  are  criti-
cal  for an  environmentally sound  operation.   During  site  completion,
proper final grading, dressing,  and  seeding  prevent  long-term  erosion  and
siltation problems.
         6.3.1.3  Mud
Mud  is  usually caused by  improper  drainage but can  be  a problem at  any
site during  heavy  rains  or spring thaws.   To  minimize the effect of  mud
on operations, access  roads  should  be constructed of  gravel.   If  practi-
cal, a  wash  pad  should  be  located  near the exit  gate to clean mud  from
transport vehicles.
         6.3.1.4  Dust
Dust  is  usually  caused  by wind  or the  movements  of  haul  vehicles  and
equipment.   To minimize  dust,  access  roads  should be  graveled.    Also,
areas  that  are   covered  with  interim  or  final  soil  cover  should  be
vegetated as soon after their completion  as possible.   As  an  alternative,
water can be applied to dusty roads.
         6.3.1.5  Vectors
Vectors at  sludge  landfills include  flies  and mosquitos.   Flies can  be
best controlled by placing  adequate compacted  cover  soil  as  frequently  as
possible.  Studies have shown that a  daily cover  consisting  of  6  in.  (1.3
cm) of compacted low-clay  content  soil  will  prevent fly  emergence.   How-
ever, even under the  best  of  conditions,  a sludge landfill  should have  a
regular  inspection  and  fly control  program.    Local  controls can   best
dictate the  specifics of  any such  program.    Mosquito   control  is   best
                                   6-23

-------
obtained by  preventing  development of stagnant  water  bodies anywhere  on
the site.  Continuous grading to fill low spots  is essential.
         6.3.1.6  Odors
Odors can  be a  serious  problem at  a sludge  landfill  unless preventive
steps are taken.  The sludge should be covered as frequently  as necessary
to minimize  odor problems.   Lime  or  chemical  masking  agents  can be  ap-
plied to reduce  odor  problems.   An effective  means  of reducing  odors  is
to limit  storage of  the  sludge.    Ideally,  storage  of  sludge  should  be
accomplished at  the wastewater treatment  plant.
         6.3.1.7  Noise
Noise  sources  at sludge  landfills  include operating  equipment  and  haul
vehicles.  Generally, the noise  is similar to that  generated  by  any  heavy
construction activity,  and  is  confined to the  site and the  streets  used
to bring sludge to the  site.  To minimize the effect,  every effort  should
be made to route traffic  through the  least populated areas.   Further,  the
site can be  isolated  so that the noise  cannot  carry to nearby  neighbor-
hoods.  The use of earthen  berms and  trees  as noise barriers can be  very
effective.  On the site,  noise  protection for employees will be  governed
by existing Occupational  Safety  and Health Act  (OSHA)  standards.
         6.3.1.8  Aesthetics
To make the  sludge landfill  acceptable,  every  attempt  should be made  to
keep the site compatible with  its  surroundings.   During  site  preparation,
it  is  important  to  leave as  many  trees  as possible  to  form  a  visual
barrier.  Earthen  berms  can  be similarly used.   The use  of architectural
effects at the  receiving area, the  planting  of trees  along  the  property
line, and confining dumping  to  designated  areas  will assist in the  devel-
opment of a  sound  operation.  Additionally, every attempt should be  made
to minimize  the size of  the  working  area.
         6.3.1.9  Health
Although there  is  a  possibility  that  pathogens  will  be  present  in  sludge,
particularly  if  undigested,  no health  problems  have  been  reported  by site
operators.  Nevertheless,  personnel  should  use  caution  when  transporting,
handling,  and covering sludge.  Washing  facilities  should be  located  on
or near the disposal  site  for  use  in  case of  bodily  contact  with  sludge.
                                    6-24

-------
              6.3.1.10  Safety


As with  any  construction  activity,  safety methods must be implemented  in
accordance with  OSHA guidelines.   Work  areas  and access roads  must  be
well marked  to avoid on-site vehicle mishaps.
     6.3.2  Inclement Weather Practices
Prolonged  periods  of rainy  weather  or freezing  temperatures  can  impede
routine  operation  of a  sludge landfill.   Anticipating  the  operational
problems and addressing contingency operations  in the operation plan will
promote  efficient  operations.   A listing  of  potential  inclement weather
problems and solutions has been included in Table 6-2.


     6.3.3  Hours of Operation


Hours of operation should coincide with hours of  sludge receipt.  In this
way, personnel  and equipment are available to direct trucks to the  proper
unloading  location;  assist  if trucks become  mired in  sludge  or mud;
and/or cover the sludge quickly to minimize odors.   If the operation plan
calls for daily covering of  sludge, hours of operation should  continue at
least  1/2  hr  past  the  hours  of  sludge  receipt  to  allow  for  cleanup
activities.   Sludge  deliveries after  hours  at  the landfill  should  be
discouraged.
     6.3.4  Special Wastes
Municipal  sludge  landfills  will  generally  receive  grit,  skimmings,
screenings,  and   ash   periodically.     In  most   cases,   handling  and
landfill ing  procedures  are  similar to  those  employed  for  sludge,  but
there  are  some important exceptions.   Grit,  screenings,  and skimmings,
because  of  their  high  organic  content,  are frequently  sources  of odor.
Consequently,  landfills may  charge a  higher  fee  and  will  usually  not
stockpile  these  wastes.   Delivery  of  grit,  screenings,  and  skimmings
should be coordinated with active operating hours to assure that they can
be processed.  Ash,  on  the  other hand, can be stored  but  should  be kept
dry if possible.   If ash  composition a  significant  portion of  the waste
disposed,  then  application  rates   should  be  lowered  because  of  the
relatively higher  heavy metal  concentrations.   A  further  discussion  of
the characteristics  and  comparison of  ash  is  presented   in Chapter  3,
Sludge Characteristics and Landfill ing Methods.
                                    6-25

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                  TABLE 6-2
INCLEMENT WEATHER PROBLEMS AND SOLUTIONS
Inclement
Weather Sludge Loading
Conditions and Transport
Wet Problem: If hauling
great distances, wet
weather conditions
may increase liquid
content of sludge.

Solution: Cover
transport vehicle.



















Cold Problem: Sludge
freezes in haul
vehicles.

Solution: Line
trucks with salt
water, straw, sand
or oil . Do not
allow prolonged
exposure to cold
(park in garage).
Use exhaust to
heat the trailer.








Site Preparation
Problem: Maneuvera-
bility of equipment
hindered in mud.

Solution: Plan to move
operation to an acces-
sible working area.

Problem: Depressions
accumulate water, may
draw flies, mosquitos.

Solution: Grade area
to promote surface
runoff. Use insecti-
cides only when neces-
sary.










Problem: Deep pene-
tration of frost in
trench areas.

Solution:
- Construct trenches
during good weather
and save for cold
months.
- Do not remove snow
(acts as insulator)
or allow vehicles
to ride on trench-
ing areas (causes
frost to penetrate
deeper into the
ground) .
- Hydraulic rippers
or jackhammers are
to be used as a last
resort.



Sludge Unloading
Problem: Maneuvera-
bility of transport
vehicles hindered in
mud.

Solution: Place sand
or gravel in areas to
improve traction. In-
crease depth of road
material.

Problem: Instability
of trench walls may
cause collapse while
unloading.

Solution: Have trans-
port vehicle dump at
trench 1 ip and push
sludge into trench
with equipment.
Problem: Mud and sludge
accumulates on haul
vehicles and equipment.
Solution: A washing pad
at the receiving area
will clean vehicles.
Problem: Tailgates
freeze.

Solution: (1) Spray
ethylene glycol on
frozen parts. (2) use
exhaust to heat frozen
parts.
Problem: Previously
(f al 1 season) muddy
roads form severe ruts
and chuck holes.
Solution: Regrade and
build before winter
reeze.







Sludge Handling
and Covering
Problem: When
mixing sludge
with refuse or
soil , need more
mixing material .

Solution: Ensure
sufficient supply
of refuse or soil
material .

Problem: Ponded
water collecting
in trenches.

Solution: Use
potable pump
to remove
excess water.








Problem: Deep
penetration of
frost in cover
supply areas.

Solution: Accum-
ulate stockpile
in good weather.
Ensure supply of
cover material ;
insulate piles
with tarpaulin or
hay.
Problem: Equlp-
ment freeze-up.

Solution: Trucks
or crawlers should
be well cleaned
of sludge and
soil.
                    6-26

-------
Another  factor  that should be  anticipated  is the fluctuations  in  treat-
ment  plant operations  and  the consequent  variation  in  the  characteristics
of  the sludge  delivered.   Occasionally,  excessively  wet  or  malodorous
loads  may  be  received.  Operational  procedures should  be  established  for
these  loads.   Typically,  procedures  range from  outright  refusal   of  the
load  to  maintenance  of  special  areas  or  soil  stockpiles  to   handle
substandard loads.

6.4   Equipment and  Personnel


A wide  variety  of equipment is  utilized  at  sludge landfills.   Equipment
selected depends  largely on (1) landfill ing  method and design  dimensions
employed and  (2)  quantity  of sludge received.


Since  equipment  represents a  large capital  investment  and accounts  for  a
large  portion of  the  operating  cost,  equipment selection should be based
on a  careful evaluation  of the  functions  to be  performed and  the cost  and
ability  of  various  machines to  meet these  needs.  Contingency  equipment
for downtime and  maintenance may be necessary at  larger sites.   These  may
be rented or borrowed  from other municipal functions.


Table  6-3  provides  guidance on the  suitability  of  equipment to perform
selected sludge  landfill ing tasks.  Table 6-4 provides typical  equipment
selections for  seven  operational  schemes.   These matrices  are meant to
give  general  guidance on  the  selection  of  sludge  landfill  equipment.
However,  it  should   be noted  that  general  recommendations  on  equipment
selection  can  be misleading.   In  all  cases, final   selection  should be
based  on  site-specific   considerations.     Figures   6-12  through 6-15
illustrate typical  equipment used  at sludge landfills.
The  importance  of employing  qualified
sludge  landfills  cannot be overstated.
the difference  between  a well-organized,
operation.
and  well-trained  personnel   at
Qualified  personnel  often make
efficient  operation  and a poor
Typical positions required at sludge landfills  include the following:


     1.  Equipment Operator.  At many sludge landfills, these will be the
         only personnelrequired.   Tasks  performed  are mostly  those of
         equipment  operation.   However,  other  tasks  include  routine
         equipment    maintenance    and    directing    sludge   unloading
         operations.
                                   6-27

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                                     6-29

-------
       FIGURE  6-12

         SCRAPER
     FIGURE 6-13

BACKHOE WITH LOADER
                     •"**•», "
                  •.'•:\. #,?-
          6-30

-------
   FIGURE 6-14
   LOAD LUGGER
   FIGURE 6-15
TRENCHING MACHINE
      6-31

-------
     2.   Superintendent/Foreman/Supervisor.     This   position   involves
         overseeingallaspectsofthe  landfill  operation,  including
         keeping  cost  records,  processing  personnel  grievances,  and
         managing the  operation.   Also,  this  person   often  serves  other
         functions, such as operating equipment.

     3.   Mechanic.  Major  equipment  maintenance and repair  is  performed
         by qualified  mechanics.  Mechanics  or maintenance  teams  seldom
         are  needed  full-time  on  site.  They  may  come  to  the site  as
         repairs are required.

     4.   Laborer.  Larger  sites may need  one  person to  maintain control
         devices for leachate collection and treatment, odor control, and
         mud  and  dust  control.  He  also  can ensure  that fencing  and
         access roads are properly maintained.
6.5  Reference

1.  Leadbetter,  R.  H.   Design  Considerations  for  Pulp  and  Paper-Mil 1
    Sludge Landfills.   U.S. Environmental  Protection  Agency.    EPA 600/
    3-786-111, December 1976.
                                    6-32

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                                CHAPTER 7

                               MONITORING
7.1  Introduction
Environmental  and  legal  sensitivity  to  potential  water  contamination
necessitates  the  monitoring  of  sludge  landfills.    The  purpose  of
monitoring may  include establishing baseline  data,  detecting contamina-
tion, satisfying regulatory constraints, securing data for use in litiga-
tion, or  conducting  research  projects. Despite  the  particular objective
of any monitoring network, site monitoring will continue to constitute an
increasingly integral component of any sludge landfill  operation.  Ideal-
ly, monitoring  should  be used to confirm  the  predictions  and judgements
made  during  the  project development  and  design  stage  with  respect  to
protecting  the  ecosystem.    Monitoring  at  a  sludge  landfill  usually
addresses  groundwater  and/or  surface  water  and occasionally  gas migra-
tion.  Monitoring  of surface  water and  gases  are not required  if there
are no surface water bodies or structures nearby.


7.2  Groundwater Monitoring
A  series  of  evaluations  are  usually  made prior  to  implementation  of
groundwater monitoring.  The items to be evaluated include:
    1.  Pertinent conditions of the hydrologic framework

    2.  Characteristics of the sludge received

    3.  Man-induced  and  geologic  features   affecting  the  movement  of
        leachate.

    4.  Groundwater use


      7.2.1  Hydrologic Conditions


In  a  preliminary  form,  the  following  items  require  determination  for
hydrologic characterization at a site:


    1.  Climatological  setting

    2.  Groundwater delineation  such as  depth,  flow  patterns,  fluctu-
        ations, etc.

                                   7-1

-------
                              FIGURE  7-1

                    LANDFILL WATER BALANCE  SIMPLIFIED
(PREC
+ IRR
"s
PIT*
GAT
\/
moN
ON)
/ (EVAPQTRA
\
ASPIRATION)
                                                        (SWFflCE RUNOfT)
                                    GROUND-WATER FUDW
Figure 7-1 is a simplified  hydrologic  cycle  illustrating these factors.
Examination of these  hydrologic  components  should be conducted to a level
of detail commensurate with the  goals  of  the  proposed monitoring system.
          7.2.1.1  Climate


Information of interest  includes:


    1.  Historical rainfall  intensity  data for a 24-hr period

    2.  Maximum monthly  and  yearly  precipitation data

    3.  Temperature,  evapo-transpiration,  and wind information


These records can  usually be obtained from  a nearby National  Oceanic and
Atmospheric  Administration  (NOAA)  weather  station.   Estimates  of  such
data may be necessary if sources  for existing data are unavailable.
                                     7-2

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          7.2.1.2  Groundwater  Conditions


An examination  of the  groundwater  system  includes  the  following:


    1.  Groundwater  streamline  patterns

    2.  Depth of groundwater

    3.  Groundwater  quality and  uses

    4.  Seasonal fluctuations in depth
Prior  to  any field investigation  a  number of information sources  should
be  contacted to define  the  regional  and  local  hydrologic  regime.   Re-
gional  sources  include  federal,  state, and  private  publications, maps,
aerial  photographs, and  remote  sensing  imagery.  Useful  local  information
can be  obtained from consultants,  well  drillers, city or  county  agencies,
nearby  universities,   and  adjacent  land  owners.    These  other  sources
usually provide data for both regional  and  site specific  conditions.


If  existing  background  data  does  not  provide  sufficient information  on
groundwater  conditions,  a relatively  inexpensive  method utilizing three
wells  can  be used to  supplement  this  knowledge.    The  usual  process  in-
volves  installing three well   points  below  the  groundwater table in  a
triangular arrangement surrounding sludge  landfills.  Absolute elevations
of  each well are  surveyed and  recorded.    Water   level  measurements  in
these  wells  are made  periodically,  and water  level  contours developed.
This  provides  information on  streamline  (flow)   patterns,  groundwater
depths, and,  if monitored  throughout the course of a year,  data on  sea-
sonal  groundwater fluctuations.   Background groundwater  quality  levels
should  also  be  identified, either by  reviewing  available information  or
by  analyzing water samples  from  nearby  wells  upstream  from  the  sludge
landfill.
     7.2.2  Sludge Characteristics
Ideally, the  sludge  should  be thoroughly characterized prior to  landfil-
ling.  The  viability  of  its  chemical  and physical  properties should  also
be determined.   Characteristics of primary  interest  are  the solids  con-
tent,  heavy metals  (e.g.,  lead,  zinc,  cadmium),  pH, and  nitrates.  In
addition, organics and cyanides are important constituents that should  be
identified.   Constituents that are present at relatively high concentra-
tions  and/or  are  highly soluble  in  water  should  be  included   in  the
groundwater analysis  since  it  is  likely  that these constituents would  be
present in the leachate.
                                    7-3

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     7.2.3  Man-Induced and Geologic Features


Other  factors  which  can influence the  groundwater  flow patterns or  con-
tamination levels are wells, subsurface barriers, geologic conditions,  or
nearby possible  waste  point sources. These  factors  could  manifest them-
selves  in  a  variety of  features such  as  fractured  bedrock,  abandoned
wells, highly  porous soil  horizons,  septic tanks,  etc.   Depending  upon
the intensity  of  the monitoring,  either a background geologic report  (if
available) or  an on-site investigation  is  needed. Field geologic examina-
tions  should  include all  geologic  formations down  to  and  including  the
aquifer.
     7.2.4  Field Installations
Proper location  and  installation of monitoring  wells  are essential  to  a
monitoring program.  A  number of excellent references should be  reviewed
for  determining  which  combinations  best  suit  a  particular monitoring
program  [1][2][3][4][5][6][7].    Generally,  once  the  hydrogeological
setting  and  the  waste  characteristics have  been defined, it is  possible
to develop a site specific monitoring plan [1][8][9].
In field installations, particular attention  should  be  given  to  two major
items to  ensure optimum benefit  from  each sampling  point.   These items
are  proper  vertical  and horizontal  placement  and  the selection of samp-
ling devices best suited to the  particular  goals of  the  study.   The loca-
tions  and  depths at  which the  monitoring wells  or devices  are placed
should  be  based on the information obtained  during the site  investiga-
tion.   Monitoring  wells   should  be placed  in those  areas  representing
optimum  pathways for  contaminants  migrating  from  the  sludge  landfill.
Wells  should  be installed  10  ft  (3 m)  or deeper  into the  groundwater.
Knowing (1) the age of the sludge landfill, (2) approximate  permeability
values  in  the  zone  of aeration,  and   (3)  directions  and  velocities  of
groundwater flow, rough estimates  can  be  derived as  to  the  maximum aerial
extent  of  contaminant  migration.  This  approximation can provide a  zone
of highest  probability  for  leachate  detection.
          7.2.4.1  Characteristics of the  Aquifer
Some  of  the  site-specific  characteristics that will influence the  place-
ment  of  monitoring wells are:
    1.  Geologic  nature  of  the  aquifer

    2.  Characteristics  of  the  potential  leachate

    3.  Groundwater  flow rates

                                    7-4

-------
For  the  purposes of  monitoring,  it  is  useful  to  categorize an  aquifer
according  to the  nature of  its  porosity.   Porosity,  in  lurn,  may  be
intergranular,  fracture  induced,  or solutional.   Unconsolidated  alluvium
and  consolidated  sedimentary  rock usually exhibit flow via  intergranular
porosities;   crystalline  rocks   exhibit   movement   via   fractures,   and
limestone,   marble,   and  other  soluble   rocks   exhibit  movement   via
solutional channels.
The  rate  of groundwater flow through  some sedimentary or alluvial  aqui-
fers  may  be  much  slower  (typically  4.9 ft/yr  (1.5  m/yr))  in  clay  or
compacted  shales   than  in solutional  or fractured  aquifers  (up  to  16
ft/day  (5 m/day)).   The distance at  which monitoring stations should  be
located is  determined  in part by the  rate  of groundwater  flow:  a  greater
down-gradient  distance is  required  for  rapid  flows,  a  shorter distance
for  slower  rates.
The  movement of  groundwater through  sedimentary  aquifers  is  generally
isotropic, determined chiefly by the gradient.   Flow through  fractured  or
solutional  rock,  on  the  other hand,  exhibits  preferential  channels  of
movement.   Again, the  placement  of monitoring  wells  should  accommodate
these differences  by locating monitoring wells  along  major fractures  or
solution channels where appropriate.
The depth to which  a  well  should  penetrate the aquifer is partly  a  func-
tion  of  the  leachate.   Since  groundwater exhibits  laminar  flow  in most
aquifers,  it  does  not  generally  disperse  itself through  the aquifer,
rather  it  moves in a cohesive plume.   This plume may  "float" atop  the
water table or  "sink"  to the bottom,  depending  on  the  specific  gravity of
the  leachate.    Knowing the  nature  of  the potential  contaminants will
enable  landfill  operators to  predict  the movement  of  the  plume  and
consequently the extent  of penetration required for monitoring  wells.
Other characteristics  of the aquifer that  should  be ascertained are  the
presence of artesian pressure, presence of multiple  aquifers  separated  by
aquitards or  aquicludes, and the location  and  orientation of faults  and
major fractures through  the  aquifer.  Perched water  tables  should also  be
located and their relationship to the primary aquifer ascertained.


          7.2.4.2  Sampling  and Monitoring Program


                        lired  at  the  sludge disposal  site is  highly  site-
                        i i ^t  Qhnnlri  hp rnnQiiltpH to  accict  in Hotormininn
The number of wells  required  at  the  sludge dispo:
specific.  A  hydrogeologist  should  be consulted •
the number of wells  required  and their locations.
to assist in determining
                                   7-5

-------
Generally the following  types  of  wells  are needed:
     t  Background wells -  located  upstream,  not affected or contaminated
        by landfill  leachate

     •  Downstream wells -  Located  a  few hundred feet downstream from the
        landfill,  used  to  detect  leachate  migration;  others  located
        immediately  downstream of  the  fill  area  in  the zone  of maximum
        leachate concentration
Care must  be taken to  ensure that  exterior  sources or  seasonal  fluctu-
ations of the streamlines  do  not  interfere with any of these wells.


Often these  monitoring  wells  or at  least  several  of the  wells  will  have
been installed  during  the  site selection and/or  design  investigations.
In fact, it  is desirable to start  monitoring  the wells 6 months to a year
before  any  sludge  filling to  establish  background groundwater  quality
including any seasonal  fluctuations, to determine  positively  whether the
landfill is  affecting the  water quality.
An  actual  monitoring  network,  established to  monitor an  existing  land-
fill,  is  presented  in  Figure 7-2.   A  hydrogeologist was  consulted  and
assisted  in  locating the wells.   After  a visual inspection  of  the  site,
the  hydrogeologist  recommended  that  resistivity  surveys  be  conducted.
                               FIGURE  7-2
                WATER  TABLE  AND  LAND SURFACE CONTOUR MAP
                         WITH TEST WELL LOCATIONS
      LEGEND

      • 3 TEST WELL

    — 8— WATER LEVEL CONTOUR

    	50-- GROUND CONTOUR

-------
Based on  the  results of this  and  on analysis of  surface  water from  the
marsh, the extent  of potential  pollution was predicted and locations  for
monitoring wells determined.   Table  7-1  presents  the wells  that were
constructed.
                               TABLE  7-1

               WELL CONSTRUCTION DETAILS, WATER  LEVELS AND
                        WATER QUALITY  (PHYSICAL)
           (all wells equipped with 2-ft screen  or well  point)
Well
1
2
3
4
5
1 in
1 ft
rc
Well
diameter
(in.)
2.5
1.5
2.5
1.5
2.5
. = 2.54 cm
= 0.305 m
= 5/9 (F-32)
Well
depth
(ft)
60
60
50
45
40

Depth to
water
(ft)
46
44
33
36
27

Specific
conductance
(uMOHS/cm)
210
220
210
270
240

Temperature
(°F)
65
65
65
65
67

Accountability  and  documentation should be  emphasized  in any  monitoring
program.   Logs  should  be kept that  indicate  the date,  time, method,  and
other  pertinent  conditions  existing  at  the  time  of  sampling.    Wells
should  be kept  locked  and  samples  should  be  handled   as  indicated  in
"Procedures  Manual  for  Monitoring  Solid Waste  Disposal  Sites" [7].   In
addition,  where  litigation  is  anticipated,  it is  valuable  to  use  an
independent  lab for sample analysis.


    7.2.5  Sample Collection


           7.2.5.1  Materials and Equipment


The type of  sampling device chosen  for  groundwater monitoring will  depend
upon the  sludge  landfill's  physical  setting  and funding.  Figure 7-3  is
an example of  a typical  monitoring  well.   Important features  include  an
impermeable  backfill,  PVC  piping and well  screen, and gravel fill  around
the well screen.  Figure 7-4 illustrates the  install ion of well  points  to
collect samples from several depths.
                                    7-7

-------
               FIGURE  7-3

  TYPICAL MONITORING  WELL SCREENED
    OVER  A SINGLE  VERTICAL INTERVAL
LAND SURFACE
SLOPED AWAY
FROM WELL
BOREHOLE
SCHEDULE 40 PVC
CASING
SLOTTED SCHEDULE
40 PVC SCREEN
                                    LOW PERMEABILITY
                                    BACKFILL
                                    GRAVEL PACK
                                       WATER TABLE
                     7-8

-------
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                                                 aovjyns QNVI MOIBB Hid3a
                                   7-9

-------
The  composition  of  the materials  selected  for groundwater  monitoring
should be examined  for possible contamination and  interference  with the
chemical  analysis.   For example, galvanized  pipe should  not be used when
testing for trace metals.   Inert materials  such  as  ABS  or PVC reduce the
possibility  of  erroneous   readings,   although   the  glues  used  on  the
fittings can  contaminate  samplings.   Disinfection of  wells, equipment,
and   containers   by   chlorination   or  other   means   is   required  if
bacteriological  examination  is  included.    Several  excellent documents
outlining containers  and  preservation techniques  for  individual  species
are available [1][10][11][12].
          7.2.5.2  Collection Techniques
Well sample collection  techniques  deserve careful  analyses.   Whether the
bail, air lift, or vacuum method is used, the interaction of these proce-
dures with the  prescribed  analyses requires  consideration [13][14].   The
means of obtaining the  sample  depends  upon  the  analyses to be performed.
For  example,  sampling of groundwater  for reduced species  (e.g.,  H£ and
redox measurements)  should  exclude the possibility  of air contamination
or  °?  injection  into  the  sample.    Systems  utilizing  pumping  or air
injection would interfere with  true  j_n  situ  measurements.   Collection
techniques  should  remain  consistent   throughout  the duration   of the
monitoring.   Pumping  a  well  for a  certain  period  of  time  prior to
obtaining  a  sample  is  recommended.   At  a  minimum,  the volume  of the
standing  water  should  be removed.    If  time  and  the  recovery  of the
aquifer  permit, 2 to 3  volumes  should  be  removed  prior  to sampling.
Similarily, collection equipment (air  lift versus  bail) should remain the
same.   In  this  way,  the  results  of the program will  not be  compromised
due  to collection variations.
          7.2.5.3  Sampling Frequency


The frequency of sample  collection  is  dependent upon the goals of a  par-
ticular  program (i.e.,  whether it  is long  or short  term)   and  on the
specific  characteristics of the site  (i.e.,  soils,  climate).   The  esti-
mated  rate  of  travel  of  pollutants  in a  given  hydrogeological   setting
will suggest intervals of  time  which will show  a change  in water quality.
Analyses  of the initial  and second  samplings  may suggest  an adjustment  of
the sampling  frequency.   Studies indicate  that leachates frequently are
released  in slugs, or high concentrations,  at periodic  intervals that are
seasonally or climatically influenced  [6].   This may dictate  intensified
sampling  efforts  at  certain  times.   Regulatory agencies  often   require
quarterly sampling.   Sampling  frequency should reflect the requirements
of  the  appropriate   regulatory agencies  as a minimum.   However, the
required  sampling frequency is  site specific  and hence  should  be adjusted
if experience indicates  that  more frequent  samplings are  necessary.
                                    7-10

-------
     7.2.6  Analytical Parameters


The  parameters  or constituents  included  in the  analysis  of groundwater
samples depend  on such factors as monitoring  goals  and levels, funding,
waste composition, uses of groundwater, regulatory requirements, etc.   If
the groundwater is potable, parameters for which drinking water standards
have been established  should be measured [15].  If high concentrations  of
certain heavy  metals, or  toxic  chemicals,  are detected  in  the   sludge,
they should be  included  on  the groundwater monitoring  list.   No   list  of
parameters applies to  all cases.   However, a recent study indicates that
lead,  iron  and  TOC  are  the  constituents most  frequently  observed   in
leachate from sludge landfills and consequently may be  considered  as good
indicator parameters.  Based on sludge characteristics  and a  recent study
[6],  it  is  recommended  that  the  following   parameters   be  analyzed
regardless of uses:
      1.   pH
      2.   Electrical  conductivity or total  dissolved solids (TDS)
      3.   Iron
      4.   Nitrate
      5.   Chlorides
      6.   Total  organic  carbon (TOC)  (if not feasible,  COD)
      7.   Heavy  metals (expecially lead)
      8.   Methylene blue-active substances  (optional, depending on
          sludge).


 The  water temperature and depth at the time of  sampling  should  be noted.
 The  results  from the  downstream and  on-site wells  should  be  compared  with
 those from the  background well and the drinking water  standards or other
 pertinent regulations [15].   Seasonal  variations  in contaminant  concen-
 trations  should be  noted.    Typical  quantities of  dissolved solids  are
 presented in  Table 7-2.
                                    7-11

-------
                                     TABLE  7-2


RELATIVE  ABUNDANCE  OF  DISSOLVED SOLIDS  IN  POTABLE  WATER  [16]






                       Major Constituents (1.0 to 1,000 mg/1)

                       Sodium                 Bicarbonate
                       Calcium                Sulfate
                       Magnesium               Chloride
                                      Silica

                       Secondary  Constituents (0.01  to 10.0 mg/1)

                       Iron                   Carbonate
                       Strontium               Nitrate
                       Potassium               Fluoride
                                      Boron

                       Minor Constituents (0.001 to 0.1 mg/1)

                       Antimony               Lead
                       Aluminum               Lithium
                       Arsenic                Manganese
                       Barium                 Molybdenum
                       Bromide                Nickel
                       Cadmium                Phosphate
                       Chromium               Rubidium
                       Cobalt                 Selenium
                       Copper                 Titanium
                       Germanium               Uranium
                       Iodide                 Vanadium
                                      Zinc

                       Trace Constituents (generally less than 0.001 mg/1)

                       Beryllium               Silver
                       Bismuth                Thallium
                       Cesium                 Thorium
                       Gallium                Tin
                       Gold                   Tungsten
                       Indium                 Zirconium
                       Lanthanum               Platinum
                                           7-12

-------
     7.2.7  Analytical Methods


          7.2.7.1  Sample Size and Preservation


Table 7-3 is a brief description of  sampling methods  recommended  by  Chi an
and  DeWalle  for the  sampling  of concentrated  leachate,  as presented  in
"Procedures  Manual  for  Groundwater Monitoring  of Solid  Waste  Disposal
Facilities" [1].  Information and methods  of minimizing  interferences  are
included  in  this table  as  well  as recommendations  concerning  sampling
containers  and  volumes  required.    This  document  also  provides   an
excellent discussion of  analytical methods for  leachate  analysis.


          7.2.7.2  Field Testing Versus  Testing  in  the Laboratory
The majority  of  tests  performed  on leachate samples  are  run in the  ana-
lytical laboratory  on  samples  which have been preserved by  refrigeration
or chemical means.  A  limited  number  of tests, however, can be  performed
at the  sampling  site  on a  freshly drawn sample.  There  are a  number  of
advantages  in field testing in  which sample  degradation  is  practically
eliminated, along with  the  need  for sample preservation,  transportation,
and handling.  An  added  advantage is  the  ability to  re-sample and  re-
analyze immediately, on site,  if it is  suspected that  a particular  sample
is not  representative or valid.  There  are  also disadvantages  encountered
in  field  testing  and  these  usually  relate  to the   reliability  of  the
particular method and equipment used  for the test.


Some tests  can  be run  in the  field with the  same  methods and  equipment
which  would  be  used in  the laboratory  and yield  the same reliability.
Among  such  tests  are  those involving the  measurements of pH, oxidation,
and specific  ions by means  of specific  ion  electrodes.   The  equipment
used in these tests is available  in  portable models  which  are  of  equal
applicability in the field and laboratory.


Other  tests  are  sometimes  performed  exclusively  in  the  field   using
methods and equipment  specifically designed for field  use.   A  number  of
commercial kits are available  for  such  purposes.  While offering distinct
advantages, there  are  also  disadvantages  inherent  in the  use  of  field
kits.   An evaluation of  field kit usage  is  presented  in "Handbook  for
Monitoring Industrial  Wastewater"  [17].


7.3  Surface  Water Monitoring


Surface water monitoring is usually implemented as a  routine component  of
a total network.  The proximity of  a  sludge landfill  to surface  water  and
drainage  patterns will  determine  whether  surface  water monitoring   is
necessary.

                                   7-13

-------
      TABLE 7-3

  SAMPLE SIZE AND
SAMPLE PRESERVATION9
Measurement
Acidity
Alkalinity
Arsenic
BOD
Branide
COD
Chloride
Chlorine Req.
Color
Cyanides

Dissolved
Oxygen
Probe
Winkler
Fluoride
Hardness
Iodine
NBAS
Metals
Dissolved

Suspended
Total
Mercury
Dissolved




Total



Nitrogen
Ammonia

Kjeldahl
Nitrate
Nitrite
NTA
Oil S Grease

Organic Carbon

pH

Phenol ics

Vol.
reg.
(ml)
100
100
100
1,000
100
50
50
50
50
500



300
300
300
100
100
250

200


100

100




100




400

500
100
50
50
1,000

25

25

500

Container
P,Gb
P,G
P,G
P,G
P,G
P,G
P.G.
P,G
P.G
P,G



G only
G only
P.G
P,G
P.G
P,G

P,G




P.G




P,G




P,G

P,G
P.G
P.G
P,G
G only

P,G

P,G

G only

Preservation
Cool , 4°C
Cool, 4°C
HN03 to pH < 2
Cool , 4°C
Cool , 4°C
H2S04 to pH < 2
None Req.
Cool , 4°C
Cool, 4°C
Cool , 4°C
NaOH to pH 12


Det. on site
Fix. on site
Cool, 4°C
Cool , 4°C
Cool , 4°C
Cool , 4°C

Filter on site
HNO, to pH < 2
Filter on site
HN03 to pH < 2

Filter
HN03 to pH < 2



HN03 to pH < 2




Cool , 4°C
HoSOa to pH < 2
Cool , 4°C
HjSOd to pH < 2
Cool , 4°C
H2S04 to pH < 2
Cool , 4°C
Cool , 4°C
Cool , 4°C
H2S04 to pH < 2
Cool , 4°C
H2S04 to pH < 2
Cool , 4°C
Det. on site
Cool , 4°C
H3P04 to pH < 4
1.0 g CuS04/l-
Standard
Holding Method
timef NumberS
24 hrs
24 hrs
6 raos
6 hrsc
24 hrs
7 days
7 days
24 hrs
24 hrs
24 hrs



None
None
7 days
7 days
24 hrs
24 hrs

6 months

6 months


38 days
(glass)
13 days
(hard
plastic)
38 days
(glass)
13 days
(hard
plastic)

24 hrsd

24 hrsd
24 hrsd
24 hrsd
24 hrs
24 hrs

24 hrs

6 hrsc

24 hrs

402
403
404
507
406
508
408
412
204
413

402



414
309
416
512
301




315









417
418

421
419
420
—
502

505

424

574

          7-U

-------
                          TABLE 7-3
                         (continued)
Measurement
Phosphorus
Ortho-
phosphate,
dissolved
Hydrolyzable

Total
Total .
dissolved

Residue
Filterable
Non-filterable
Total
Volatile
Settleable
matter 1
Selenium
Silica
Specific
conductance
Sulfate
Sulfide

Sulfite
Temperature 1
Threshold
odor
Tu rb i d i ty
Vol.
rey.
(ml)


50

50

50

50


100
100
100
100

,000
50
50

100
50
50

50
,000

200
100
Container


P.G

P,G

P.G

P.G


P.G
P,G
P.G
P.G

P,G
P.G
P only

P.G
P.G
P.G

P.G
P.G

G only
P.G
	 Preservation


Filter on site
Cool, 4°C
Cool , 4°C
H2S04 to pH < 2
Cool, 4°C

Filter on site
Cool , 4°C

Cool , 4°C
Cool, 4°C
Cool, 4°C
Cool , 4°C

None Req.
HN03 to pH < 2
Cool, 4°C

Cool , 4°C
Cool, 4°C
2 ml zinc
acetate
Cool, 4°C
Det. on site

Cool , 4°C
Cool, 4°C
Holding
time'


24 hrsd

24 hrsd

24 hrsd

24 hrsd


7 days
7 days
7 days
7 days

24 hrs
6 months
7 days

24 hrse
7 days
24 hrs

24 hrs
None

24 hrs
7 days
Standard
Method
NumberS


4E5








208




208
318
426

205
427
428

429
212

206
214
a  More specific instructions for |>rusurv,ition and  vimpl Iny aru  found  with
     ej^ft procedure as detailed  in the  literature [1].  A general  discussion
     on sampling water and industrial  wastewater  may be found  in  ASTM,  Part
     23, p. 72-91  (1973).

b  Plastic or glass

c  If  samples cannot  be returned  to  the  laboratory  in less than 6 hrs  and
     holding time  exceeds this  limit,  the  final  reported  data  should  indi-
     cate the actual  holding  time.

d  Mercuric chloride may be used as an alternate  preservation  at  a  concen-
     tration of 40 mg/1,  especially  if a longer holding  time  is  required.
     However, the  use of mercuris  chloride  is  discouraged  whenever  pos-
     sible.

e  If the sample is stabilized by cooling,  it should  be  warmed to 25°C  for
     reading or temperature correction  made and results reported at 25°C.

f  It  has  been  shown  that  samples  properly  preserved  may  be  held   for
     extended periods beyond  the recommended holding time.

9  The  numbers  in  this  column  refer  to  the  appropriate parts  of the
     "standard Methods  for  the  Examination of  Water and  Wastewater,  14th
     edition. APHA-AWWA-WPCF,  1975.
                                7-15

-------
Selection of  surface  water sampling  stations,  equipment, and  procedures
should  follow  a  methodical   approach  similar  to   that described   for
groundwater monitoring.    Each  surface water  monitoring  item  should be
evaluated in  terms of compatabil ity  or possible  contamination with  the
constituents to be analyzed.
Surface sampling  stations  should  be located in areas which represent  the
greatest  potential  for contamination.   These  points can  be determined
after examining  the  pathways available for  leachates to enter a surface
water body.   Consideration  should also  be given  to selecting  stations
which can  provide consistent samples throughout  the monitoring  program.
Flow  patterns  and seasonal  variations  should  be  addressed  when appli-
cable.
Surface  water sampling  equipment should  be  suited  to  the  goals  of  a
particular  program.    Sampling  equipment and  procedures can  range  from
continuous  or intermediate  automated samplers  to manual  collection  by
filling a container by hand.  Manual  sampling  is  almost  always considered
to be adequate.
Indicator  parameters  and  analytical   methods  used   for   surface  water
samples  should  be  consistent with  selected  procedures  for  groundwater
sample  testing.   The  effects of  surface water  mixing  and  interference
with contaminants should  be considered.
7.4.  Gas Monitoring
More  often than  not, sludge  landfills  are  located  quite  distant  from
structures and gas monitoring  may  not  be required.  When  it  is  required,
the  gas  of major concern  is  methane.   Methane  gas  in concentrations  in
excess  of 5% is  explosive.    If there  are structures  near  the  landfill
(e.g.,  a  wastewater  treatment  plant,  residences,  etc.)  a  methane  gas
control  system  should be  installed and  a monitoring  program should  be
carried  out.
The  sampling  devices should be  located  in  whatever direction  structures
exist.   Typically,  sampling  devices  may  be  located  near  the  property
boundary and  off-site on the landfill  side  of  structures  in  pathways  most
susceptible to gas migration [18][19].


Gas  sampling  devices usually  consist  of  simple, inexpensive gas  probes.
The  probe  is  usually  polyethylene, copper,  or  stainless  steel  tubing.
Due  to the small  diameter of probes  (
-------
The  sample  collection technique depends  upon  the type of sampling  probe
installed.   Most methods  require  some form  of  evacuation,  although  the
specific  type  may  vary.    The  sampling  frequency  depends  upon  the
particular monitoring  program.   The  estimated rate of movement  of  gas  in
a  particular soil may  be useful for  developing  optimum periods.   As  a
minimum,  if  gas monitoring  is  required,  samples  should  be  taken at  the
same time that  water  samples  are taken.   Most  frequently  a portable  meter
is used to monitor methane gas.  This  instrument  indicates the percentage
of methane gas  up to  the  lower  explosive  limit of 5%  methane.
7.5  References

1.  Procedures Manual  for  Groundwater Monitoring at Solid Waste  Disposal
    Facilities.   U.S.  Environmental  Protection  Agency.    EPA-530/SW-611.
    August 1977.

2.  Manual  of Water  Well   Construction Practices.    U.S.   Environmental
    Protection Agency.  EPA-570/9-75-001.  September 1975.

3.  Campbell,  M.D.  and J.H.  Lehr.   Water Well  Technology.   McGraw-Hill
    Book Company.  1974.

4.  Evertte,  L.G.,  et  al.   Monitoring  Groundwater Quality:   Costs and
    Methods.   Environmental  Protection  Agency.   EPA  600/4-76-023.   May
    1976.

5.  McMillon,  L.G.  and  J.W.  Keeley.   Sampling  Equipment  for Groundwater
    Investigations.  Groundwater.  8(3):10-15, 1970.

6.  SCS  Engineers.    Investigation   of Groundwater   Contamination  from
    Subsurface Sewage  Sludge  Disosal.   Vol.  1:   Project Descriptions and
    Findings.   Final  Report  submitted to U.S.  Environmental  Protection
    Agency, Washington, D.C.  Contract  No. 68-01-4166.  May  1978.

7.  Wehran  Engineering  Corporation.    Procedures  Manual   for  Monitoring
    Solid Waste Disposal Sites.  Environmental Protection Agency.  Office
    of Solid Waste Management Programs.  1976.

8.  Parizek,  R.R.   Site  Selection  Criteria for Wastewater Disposal-Soils
    and  Hydrogeologic  Considerations.    In:    Recycling   of  Treatment
    Municipal Wastewater and Sludge through Forest and Cropland.  Sopper,
    W.E.   and L.T. Kardos  (ed.).   EPA-660/2-74-003.   March 1974.   pp.
    95-130.

9.  Tinlin,  R.M.  (ed.).    Monitoring  Groundwater Quality:   Illustrative
    Examples.  Environmental  Protection Agency.   EPA 600/4-76-036.   July
    1976.

10. Battelle Pacific  Northwest  Laboratories.   Geothermal  Water  and Gas-
    collected Methods for Sampling and Analysis.  August 1976.
                                   7-17

-------
11. Methods for Chemical  Analysis of Waste and Water.  U.S.  Environmental
    Protection Agency.  EPA-625/6-74-003.  June 1974.

12. American Public  Health  Association.   Standard  Methods  for  the  Exa-
    mination of Waste and Wastewater.  14th Edition, 1975.

13. Sommerfeldt,  T.G.  and  D.E.  Campbell.   A  Pneumatic  System  to  Pump
    Water from Piezometers.   Groundwater.  13(3):293, 1975.

14. Trescott,  P.C.  and   G.F.  Pinder.    Air  Pump  for  Small-Diameter
    Piezometers.  Groundwater 8(3):10-15, 1970.

15. Quality  Criteria  for Water.   U.S.  Environmental  Protection Agency.
    EPA 440/9-76-023.  July 1976.

16. David, F.N. and  R.J.M.  DeWiest.   Hydrogeology.   John Wiley & Sons,
    New York.  1966.

17. Handbook for  Monitoring  Industrial  Wastewater.    U.S.  Environmental
    Protection    Agency.       Technology    Transfer.       Report    No.
    EPA-625/6-73-002.  August 1973.  pp. 5-14.

18. Engineering-Science,   Inc.   J_n  Situ Investigation  of  Movements  of
    Gases Produced from  Decompositing  Refuse.  APWA Special  Report,  No.
    29, February  1964.

19. Esmaili, H.  Control  of Gas Flow from Sanitary Landfills.   Journal of
    the Environmental Engineering Division, Proceedings of the Amer. Soc.
    Civil Enginerers.  August 1975.  pp. 555-566.

20. Anderson*  D.R.  and J.P.  Callinan.   Gas  Generation and  Movement in
    Landfills.  Loyola University of Los Angeles.
                                  7-18

-------
                                 CHAPTER 8

                              COMPLETED SITE
8.1   Introduction
The  purpose  of this chapter is  to  provide guidance in  developing  a com-
pleted  site  plan.   This plan  should  be first considered  during  the site
selection  process  and  finalized  during the design process.  Objectives of
a completed  site plan  include:
    1.  Designate  the  operational  procedures for site closure

    2.  Establish  the  criteria  that  must  be addressed before planning the
        final  site use

    3.  Determine  the  components of  final  site use that  will  ultimately
        lead  to  the selection of a  site  use that  is  publicly acceptable
        as well  as technically  practical


A plan for the final use  of  the  landfill  is a step toward acceptance of a
proposed  site.   This  is  particularly true  where  there  is  active  public
participation  in the site selection  process.  The  local  landfill  should
be  shown  to  represent  an immediate  and  future benefit to  the community.
On  the other hand,  projected   site  uses  should  be  realistic  both  in
concept and  in the method portrayed.


Final  site uses  may have a  longer life  than the  original  filling  opera-
tion.  Because of  the long-term nature  of  the  final  use,  the  completed
site plan should be prepared at  the  same time that  the landfill  is  being
designed,  since  decisions   regarding  one  can  substantially  affect  the
other.    Each  step  of the  landfill  process—initial  site  preparation,
installations  of screening  and  buffers,  placement of the  final  landfill
cover, and  revegetation--should  be  seen  as steps  toward  achieving  the
final  use [1].
By  integrating the  final   site  plans  into  the  preliminary design,  the
ultimate  value  and cost of developing  the  final  site  can be  enhanced.
Leaving  islands  of undisturbed  soil  in strategic  areas  will  enable  the
site to be developed and increase the  overall  value of  the  site.  Setting
aside part of  the  operating fees for  final  site development can  provide
the capital  needed for  site  closure.   If  the  land  is to  be   sold,  the
question  of  liability  and responsibility  for  regrading  and monitoring
                                   8-1

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should  be  considered.    In  New York,   for  instance,  the  landfill  operator
is  responsible  for  monitoring   and  maintenance  for   5  years   after  site
closure   regardless   of   whether  he   has   sold  the   property  or  not  [2].
However,  in  California  the  current  property owner   is  usually  held  liable
in court  cases.
8.2   Procedures for  Site Closure
The  following   operational   procedures   for   closing   a   site  are   to   be
performed  when  either  the  entire   sludge  landfill   or   a  segment  of   the
landfill  has  been  filled  to  capacity.   These  procedures can  be  conducted
concurrent  with  on-going  site  operation.     Procedures  for  proper  site
closure  are  outlined  in  Table  8-1.
                                         TABLE  8-1

                              PROCEDURES  FOR SITE  CLOSURE
                  •  No sludge should be  left  exposed.  Trenches  and lifts should be
                     sufficiently covered.  If  trenches and  lifts are unstable, they
                     should be well  marked using drums  or wooden barricades.

                  i  Although  the rate of  settling varies,  maximum settlement will
                     occur within the first year of  landfill ing.  Accordingly,  suffi-
                     cient time should be allowed for  the  area to settle.  As  neces-
                     sary, the area should be regraded  to account for settlement.

                  •  After maximum  settlement  has  occurred,  the  area should be re-
                     graded to ensure proper drainage.   Depressions  and cracks  should
                     be  filled  using on-site  or borrowed soil.   Bulldozers  and/or
                     graders are normally used  for spreading  and grading the soil.

                  •  One to 3 ft (0.3 to  0.9 m)  of final cover may be applied.  This
                     cover may consist of top  soil which was stripped and stockpiled
                     prior to  commencing  the  landfill ing  operation.   Soil  that  is
                     deficient in organics (e.g., sandy soil)  may require a mixture of
                     sludge at a ratio of  5:1 to 10:1.

                  •  Check sediment  and erosion  controls and modify according to any
                     change in grade.

                  *  Construction of small structures (picnic tables  shelters, etc.)
                     may be undertaken in accordance with specifications  in the final
                     site use plan.

                  •  Disassemble temporary structures and receiving areas not required
                     for final site use.

                  •  Hydroseed denuded areas with the appropriate  mixture of grasses.
                     Climate and final  site use are  a major  factor in determining the
                     type of grass and vegetation selected.

                  »  Outline a timetable to ensure that the following features are in-
                     spected at regular intervals:

                     1.  Settlement, cover soil  integrity,  and need for grading
                     2.  Buffers and vegetation
                     3.  Sediment and erosion control facilities
                     4.  Fencing
                     5.  Leachate and gas controls
                     6.  Integrity of final  site use facility
                     7.  Vandalism
                     8.  Monitoring
                                               8-2

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For  several years  after  filling  is  completed  the  site  should  be  inspected
at monthly to quarterly  intervals,  as  outlined  in  Table 8-1.   Thereafter,
inspection should  be  conducted at least  annually.   Additionally,  sediment
and  erosion  controls   should   be   inspected  during  rainy   periods   to
determine their  effectiveness.
Upon  completion  of the  site,  a  plan  detailing  the  site  development,
operation,  and  controls should  be  prepared  and  recorded with the  county
records.   The description should  include  general  types and  locations  of
wastes,  depth of  fill,  and  other  information of  interest to  potential
landowners  [1].
8.3  Characteristics  of Completed Site
When planning  a  final  site  use, critical  factors that must  be  considered
are  settlement,  bearing capacity,  final  grade, and  control  of  leachate
and  gas, and vegetation [3].
     8.3.1  Settlement
Settlement due  to  the volume reduction of  sludge  creates cracks or  fis-
sures  in  the  cover material.   It  can  contribute to substantial  movement
in  the  verticial  and/or  the  horizontal  direction,  with  displacements
ranging from 6  in. (15 cm) to 3  ft  (0.9 m).  Settlement can occur within
 a  few days  of  filling  or can  extend  over many years.   Experience  has
indicated  that  the site may  have  to  be regraded up to 3,  4,  or 5 years
after  closure.   Research  has  been  conducted  in  the   laboratory on  the
settlement of  landfilled paper mill sludges  [4][5],  but  additional   work
is  needed in  order   to  predict the  settlement of  landfilled  municipal
sludges.
The rate and extent  of  settlement  are  controlled by the interaction of  a
number of variables, including:
    1.  Sludge characteristics

    2.  Landfill ing method

    3.  Soil characteristics


Of these, the characteristics of the sludge have the greatest  impact
                                   8-3

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          8.3.1.1  Sludge Characteristics


Relevant sludge charcteristics include:


    1.  Sol ids content

    2.  Volatile solids content

    3.  Particle size and configuration


A detailed discussion  of treatment processes  and  resulting  sludge types
has been included  previously.   Sludge with  a  low  solids content  (15-20%
solids) can be expected  to  settle more than sludge  with a higher solids
content (>28% solids).  Sludge may dewater through evaporation,  infiltra-
tion  (into  porous soils)  or separation;  but  in  any  case,  as  it loses
moisture, the pore spaces  increase.   The result is  a  loss  of volume and
consequent settling.


Other factors that influence the  stability of  the  completed  site  are the
volatile solids  content and  the  size  and configuration of  sludge  par-
ticles.  In general, the higher the  volatile solids content, the  greater
the degree  of settlement.    Sludges  with  large, poorly sorted  particles
will also settle to a greater extent.


         8.3.1.2  Landfill ing Method
The landfill ing method influences the potential for settlement.  Landfil-
ling  methods  that  call  for the  mixture of  sludge  with soil  or refuse
settle in a different fashion than a method using only sludge.


Sludge with a lower solids content disposed in trenches may stratify  into
liquid and  solid  phases.   The solids  may settle to  the bottom  of the
trench, resulting in a liquid  layer  forming  at the  top.   If this separa-
tion occurs, rapid  settlement of the solid fraction results.  Conversely,
stratification may  occur where  solids  rise to the surface.   This buoyant
effect  is  caused  by  gases  of  decomposition  which   adhere   to  sludge
solids.
Area  fill  landfills (where  the  sludge is  not  contained)  may experience
horizontal  movement  or  creeping.    Area  fill  methods  are also  more
susceptible to  variable climatic conditions, which  also affect  landfill
stability.
                                    8-4

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         8.3.1.3   Soil  Characteristics


The  amount  of interim and final  cover  affects the degree  of  settlement.
Often termed  surcharge,  the  cover enhances  percolation  of  liquid  into  the
surrounding soil  by  applying pressure on the sludge.  The  ability  of  the
cover  material  to bear  weight,  inhibit   water  infiltration,  and hold
vegetation  is  important  when predicting  sludge settlement.   Soil  used  for
sludge bulking  also  affects  the  settling potential.


     8.3.2  Bearing Capacity
The bearing capacity  of  a completed landfill  is the measure of  its  abil-
ity to  support  foundations.   The bearing capacity of the  sludge  landfill
is dependent on the following:
    1.  Sludge characteristics

    2.  Landfill ing method

    3.  Soil characteristics  (bulking  and cover)

    4.  Vegetation


Currently,  limited  information is  available  on the  bearing  capacity of
sludge  landfills.   Although  laboratory  scale sludge  bearing  tests  have
been  conducted  on industrial  wastewater  sludges and  solid  waste, it is
questionable whether  these  tests  are valid  on a  large-scale municipal
wastewater  sludge  landfill  over long  periods  of time.  Although  natural
soils  produce  bearing test  values  that  fall   within  a predictable range
and  are reproducible,  it  is not  known  whether  tests  on  sludge  will
produce similar results.  Therefore,  it is suggested  that construction of
structures  on  a  sludge  landfill   site   be  restricted  to  areas  of
undisturbed soils where landfill ing of sludge  has not  occurred.

     8.3.3  Final  Grade
The final  slopes in the  landfill  should generally  range  from  2  to 5%.
Factors that influence the final grade are:
     1.  Climate

     2.  Vegetation

     3.  Soil  characteristics




                                    8-5

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In  relatively  dry climates  with suitable  vegetative cover,  slopes may
safely exceed 5%.  On the other hand, in areas with high rainfalls it may
be  necessary  to  use  extensive erosion  and  drainage  control  for slopes
above 5%.
     8.3.4  Leachate and Gas
Leachate and gas from  sludge  landfills  will  continue to be produced long
after the fill  is completed.  If not properly controlled, gas can accumu-
late  in  enclosed areas or  structures.   Also,  at  certain concentrations
gas can  stunt  or kill  vegetation.  Leachate  can  cause serious pollution
of groundwater and surface water if not properly controlled.


An  impermeable  cap placed  over  a sludge  landfill  after  completion will
decrease the potential  for leachate by decreasing  the amount of surface
water infiltration.  Gas  and  leachate  controls must be incorporated into
the design (see  Chapter 5, Design).
     8.3.5  Vegetation
In  most  instances,  a  completed  site  will   require   some  vegetation.
Through careful  selection,  plants can  enhance the attenuative  properties
of the soil as well  as perform the traditional  functions of erosion  con-
trol, infiltration management  (see  Figure 8-1), and visual enhancement.
Winter rye  has  been  found  to be effective  in  enhancing the fertility  of
the  soil.   It  has  the advantage  of  quick growth and  hence can  provide
effective early erosion control.   If  planted  with  bermuda  grass it  can
serve  to  stabilize  slopes  and  reduce  runoff.   Bunch  grasses,  such  as
canary grass, and  sod  grasses  generally provide good cover  and grow  well
in  conditions  found  in  landfills.   Where stabilized sludge  has   been
landfilled, trees can be planted and will  generally  do  well.   Information
concerning  suitable  cover  crops  is available from the  U.S.  Department  of
Agriculture,  Soil Conservation Service.   In  addition,  local  agencies  such
as county extension  services and local  universities are valuable  sources
of data.
8.4  Completed Site Use


The  selection  and design  of final  land  uses  should be  the  result of  a
comprehensive  land  planning  study that considers all aspects of  proposed
filling  operations  as well  as  final   uses.   The objectives  of the  land
planning  study should  be to  identify  uses  that  will:
                                    8-6

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                                 FIGURE  8-1

                    INFILTRATION RATES  FOR  VARIOUS CROPS
             2.8
              0.0
OLD PERMANENT
PASTURE OR HEAVY
MULCH
                                                             4-8 YEAR OLD
                                                             PERMANENT PASTURE
                                                             3-4 YEAR OLD
                                                             PERMANENT PASTURE
                                                             LIGHTLY GRAZED
                                                            PERMANENT PASTURE
                                                            MODERATELY GRAZED

                                                            HAYS
                                                             PERMANENT PASTURE
                                                             HEAVILY GRAZED

                                                             STRIP CROPPED OR
                                                             MIXED COVER

                                                             WEEDS  OR GRAIN
                                                            CLEAN TILLED
                                                            BARE GROUND
                                                            CRUSTED
                        10
                               ZO      30
                                  TIME, mln.
                                             40
                                                    50
                                                           60
      1.  Take  advantage of  the  opportunity  for permanent  improvements  to
          the landfill  that are available after filling is completed

      2.  Eliminate  or  minimize potential  off-site  conflicts with  existing
          or  future development  through the  careful  siting of  the  fill,
          maintenance   of  an  open  space  separation,   and   utilization  of
          natural  screening and buffers

      3.  Be compatible with  and  complementary  to existing  natural condi-
          tions and  activities and  help meet  the  future  needs  of  the  com-
          munity


The land  planning process  should be integrated  with site  selection and  be
carefully organized to  seek  out  relevant  information  relating  to  the
site.   Four  important  steps  to follow  are:
                                     8-7

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    1.  Perform  site  inventory.  The  existing  land  use  must  be  identified
        and  the  impact  of curtailment of current land  use (whether  it  be
        recreation, open  space,  etc.) must be determined.   The  inventory
        might  include topography,  vegetation,  water bodies,  public  faci-
        lities,  etc.    Information can  be obtained  from  aerial  photos,
        site visits,  and  review  of public  records.

    2.  Evaluate of  Needs.    To assess future  needs,  an  evaluation  of
        localplansforpopulation, utility,  and  highway projections
        should be  attempted.   Local planning offices should be  contacted
        to   determine  current  land  use   policies   for   the   area   of
        consideration.

    3.  Identify alternatives and  select  completed  site use.   Using  the
        information  obtained  above,  an  evaluation  should  be   conducted
        noting  advantages and disadvantages  of  each potential   use.   If
        site   characteristics and constraints   are  known, alternative
        ultimate land  uses  can  be  evaluated   in  terms   of   technical
        feasibility   and   costs.    The  optimum  site  use   can  then  be
        selected.

    4.  Select,  design,  and  implement  completed site  use.   After  se-
        lecting  completed site  use,  a  master  plan  should  be  prepared.
        It  should  designate  the  scheme  for  cover  soil  stockpiling,
        maintaining  positive drainage  by  regrading,  revegetation,  sedi-
        ment  control,  leachate  control,  ground  or  surface water  moni-
        toring,  and  maintaining acceptable environmental  and   aesthetic
        conditions.
8.5  References

1.  Sanitary  Landfill  Manual  of  Practice,  No. 39.   American Society of
    Civil  Engineers,  Environmental   Engineering   Division,   Solid  Waste
    Management Committee.  1976.

2.  New  York  State  Compilation  of 'Rules and Regulations, Part 360, Solid
    Waste Management Facilities.

3.  Brunner,  D.   R.  and  D.  J.  Keller.   Sanitary  Landfill  Design   and
    Operation.    U.S.  Environmental   Protection  Agency.     Report   No.
    SW-65ts.  1972.

4.  Noble, G.  Designing  for  Final  Use of the  Landfill.   (Presented  for
    Course in Sanitary  Landfill  Site Selection, Design  and  Operation at
    the University of Wisconsin -  Extension,  Department  of Engineering).
    April 1977.   pp. 4.

5.  Leadbetter,   R.  H.    Design  Considerations for  Pulp and  Paper  mill
    Sludge Landfills,  U.S. Army Corps of Engineers, Waterways Experiment
    Station.  (Prepared for Municipal  Environmental  Research  Laboratory,
    Cincinnati,  OH).  December 1976.  pp. 136.

6.  Process  Design  Manual  for  Land  Treatment of  Municipal   Wastewater.
    U.S.  Environmental  Protection Agency,  Technology Transfer.   Report
    No. EPA 625/1-77-008.   October 1977.  pp. 5-81.
                                    8-8

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                                CHAPTER 9

                          MANAGEMENT AND COSTS
9.1  Introduction


The operation of a  sludge  landfill  is  dependent upon a number of  factors
including the volume and type of sludge  received  and  site  conditions.   It
is the intent of good landfill administration  to  efficiently manage these
factors in a way which  adequately  protect the environment.  However, due
to  more  stringent  regulations  and  spiral ing  construction   costs,  the
operation of a sludge landfill is becoming increasingly costly.


Management of a sludge  landfill involves  a wide range of responsibilities
and requires a  number   of  specialties.   The  landfill  manager  has opera-
tional   responsibilities  (conformance  to the design  and  regulations,
day-to-day operation,   security, and  equipment maintenance  and   replace-
ment);   social  responsibilities (public  relations  and  personnel   hiring,
training,  and   safety);   and  fiscal   responsiblities    (equipment  and
personnel   recordkeeping,   operational    recordkeeping,    budgets,   and
financing).  Managers  of sludge landfills should become   involved in the
project  early  in   its  planning  stage.    Continuity  of   management   is
desirable throughout the operating life  of the  landfill.
9.2  Management Responsibility


Operation of  sludge  landfills  may be under public or private management.
A description  of  typical  alternative managing  organizations is detailed
below.


     9.2.1  Municipal Operations
Most sludge  landfills  are  municipal  operations.  Authority for operating
and  managing such  landfills is  usually entrusted  either to  the  sewer
department or to the department of public works.  Sewer departments  often
manage sludge landfills since wastes received at that sites are generated
by treatment plants owned by sewer departments.  Disposal  of  residuals  is
part of the wastewater treatment process at large, and costs  incurred are
usually financed through sewer  fees.   Also,  vehicles used to haul sludge
are  often  owned and  operated   by  the  sewer  department.    Finally,  many
sludge landfills  are  located  at  or  near  the  treatment   plant,  and the
property is owned by the sewer  department.
                                   9-1

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However, management  of  sludge  landfills  is increasingly being assumed by
public  works  departments.   This may  be  more  appropriate,  particularly
when  landfills  are  not located  on the  treatment  plant  property since
operation of  a  sludge  landfill  is  a construction  activity that is well-
suited to the experience and resources of  public works departments.


     9.2.2  County Operations
Management  of  sludge landfills  by  county governments  is  less prevalent
than that of municipal governments.  As with municipal  operations, county
landfills  are  often  managed  either by  the sewer  department or  by the
public works department.   However,  County landfills usually serve larger
populations  and  geographic  regions  than  municipal   landfills   and  the
attendant  economies  of scale  and  the  greater land  areas  available may
make  such  operations more  desirable  than   municipally-managed  sludge
landfills.   The  choice   of  county  or  municipal  management  usually  is
determined  by  whether  the   sewer   department  is  administered   by  the
municipality  or  the  county.     Nevertheless,  due   to  the  potential
advantages  of  county-wide  sludge  landfills  management, this  should  be
considered even when sewage is treated by several municipalities.
     9.2.3  Sanitary District Operations


Sanitary districts  are  more  likely to be responsible for managing sludge
landfills than are  their municipal counterparts  (sewer departments)  since
no  alternative  authority is  available.   Financing  for  sludge landfills
managed  by  sanitary districts is  often  easier to  secure  since they may
have  provisions  for levying  special  taxes.   Also,  these  districts  gen-
erally  service  greater  populations and may  serve several  jurisdictions.
As  a  result,  sanitary  districts  are generally better financed  and equip-
ped to  operate sludge landfills due to the  economies of  scale.


     9.2.4  Private Operations


Next  to municipal  operations, privately-managed  operations  are the  most
prevalent  type  of  sludge landfill.   Sludge  landfills  may  be operated
under  contract,  franchise,  or  permit arrangement.   In  contract  opera-
tions,  the  presiding  government  agency contracts with the private opera-
tor to  dispose  of  sludge for a  fixed lump sum  fee  or  for a unit charge
per ton, cubic yard, or  truck load.   If a  unit charge is the  basis of the
contractual  arrangement,  the  government   agency  usually  guarantees  a
specified  minimum  dollar amount  to  the  contractor.   Franchises  usually
grant the  operator  permission to  dispose  of  sludge from specified  areas
and charge  regulated  fees.   Permits  allow  the operator  to accept sludge
for disposal without regard  to source.
                                    9-2

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Private  operations may  benefit  government  agencies  that  have  limited
capita"!  available for  construction and  initial   operation  of  a  sludge
landfill.   Also,  private  operators may  be  able  to  operate  at  a  lower
cost.    However,   precautions  should  be taken  to  ensure  that  private
operators  will   provide  adequate  environmental   safeguards.    For this
reason, contract  arrangements are usually the best choice  since  operating
and performance standards can be written  into the  contract.
9.3  Equipment Management and Documentation
Equipment cost is the largest single expense incurred  in the  operation  of
most  sludge  landfills,  exceeding even the  labor  cost.  Accordingly, the
proper selection, purchase,  operation, and maintenance of equipment will
contribute substantially to the  cost efficiency of a landfill.  Following
are  some  important facets  to  consider  in  managing equipment  at sludge
landfil 1 s.
     9.3.1  Selection and Purchase
A determination  of  the type and  number  of machines  needed  to operate a
sludge landfill  is a function of  production  (speed  at which  the equipment
can accomplish an assigned task when operated appropriately),  size of  the
site, quantity of sludge  handled, landfilling  method, types of soil,  and
availability of  parts  and service.   Guidance  was  provided  in Chapter 6
(Operation) on the  selection of  equipment  under  various  conditions.   It
should be  remembered,  however, that  a determination of  equipment  needs
for an actual  sludge landfill should be made on a case-by-case basis.


Having chosen appropriate equipment, the following  cost categories should
be considered prior to purchasing:


    1.  Owning cost.   This  consists of  the price  of the  equipment,  the
        interest charges, the taxes, and the insurance premium.

    2.  Operating cost.   This  includes  costs  for  maintenance  and  fuel.
        Maintenance costs  must include  not only  repairs,   but  also  the
        price of oil, grease, and labor for  preventive maintenance.

    3.  Downtime cost.  Every effort must  be made  to keep  this cost to a
        minimum.  Standby equipment cost  must  also  be  considered  here.
        Since the operation must  continue when a machine is  down, back-up
        equipment will be needed.   Equipment rentals may be appropriate.
                                    9-3

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    4.  Resale value.  This includes the depreciation rate on the machine
        and what its  potential  market  value  may be when the equipment  is
        no longer needed.
Consideration  of  all  of the  above  cost  factors will  enable managers of
sludge landfills to get  a  complete  picture of the actual total equipment
cost.   In  addition to  the purchase  cost, operating  and  downtime costs
must be included in any cost  analysis.  These can amount to  a  substantial
percentage of  the  owning  cost over  the life of  the  sludge  landfill.   Of
course, the landfill  manager  can  recoup  some costs  through  resale of the
equipment.
     9.3.2  Operation


The  nucleus  of  the  sludge landfill  operation  is  the  equipment.   To
maximize  efficiency,  prevent equipment  damage and  personal  injury, and
ensure  an  environmentally  sound   and   economical   operation,  equipment
should  only be  operated  by  competent   and   qualified  personnel.   Ac-
cordingly,  operators  should  have  extensive experience  in  equipment
operation.  If new equipment operators are trained at  sludge  landfills,  a
qualified  operator  should  ride  along  until  the  employee  is thoroughly
competent  on  the  machine  and  the  new  operator   should  be  checked and
tested by  the supervisor  before  a  machine assignment is made.  Operators
should work cautiously at  sludge landfills,  since the unstable nature of
sludge  can  cause  equipment  operated   by  even  the  most  experienced
personnel  to  become  mired  in sludge.   After  some  experience,  however,
operators  can   learn  to  use  their equipment more  efficiently  in the
landfill  environment.
     9.3.3  Maintenance


Often equipment  maintenance is more expensive  than  the amortized annual
cost of  equipment  purchase.  Thus,  equipment  maintenance  is a  high-cost
item  and constitutes  a  substantial   part  of  the  on-going operational
expense  of sludge  landfills.


Initially,  a  sludge  landfill  manager  should  outline a   comprehensive
preventive maintenance program.   If preventive maintenance is  performed
daily, the  manager  has  taken a  major step toward  lowering maintenance
costs.   Normally,  the equipment  operator performs  routine maintenance
each  day on  his  machine;  e.g.,  checking water  and  oil, lubrication,
keeping  tracks clean,  blowing  out radiators with an air compressor, etc.
It  is critical that  these maintenance tasks be performed  daily, and  the
                                    9-4

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supervisor  should  be  personally  responsible  for ensuring  that  these tasks
are  performed.    In  some  larger  landfill   operations,  a  full-time  or
part-time mechanic  is assigned to perform maintenance and  repairs  of all
of the  landfill  equipment.


Sludge  landfill  managers should make  sure  that the operation  manual  for
each  piece  of equipment  is  readily  available.  Machine  operators  should
consult the manuals  in  order to  be familiar with the  daily  service needs
of their equipment.   These  manuals should also  be  available to mechanics
to ascertain  the specific service requirements for each piece  of  equip-
ment.
Equipment with  a maintenance  warranty  will  provide  guidelines  for mainte-
nance  that  should  be strictly followed  to  preserve the warranty  for  the
designated  period.   Failure to adhere to these  guidelines  could  increase
maintenance costs.
     9.3.4  Recordkeeping
A daily report should  be completed  by  the  operator  for  the  equipment  that
he  has  operated  that  day.   Sludge landfill  managers  should ensure  that
these records  are  complete,  up to date, and  accessible. The  objective  is
both to ensure more complete maintenance and to lower  maintenance  costs.
A sample  form  to  be completed for  this  task  has  been   included  as  Figure
9-1.
9.4  Personnel Management  and Recordkeeping
Next  to  equipment,  personnel  is  usually  the largest  single expense  in
a  sludge  landfill  operation.  Careful  screening  and hiring  of  employees
and subsequent  training  of personnel  develops an efficient operation.   A
safety program  should be  instituted as  part  of initial  personnel  training
and conducted thereafter  on  an on-going basis.  A detailed  description  of
personnel management practices is  included below.


     9.4.1  Personnel Requirements and  Hiring Practices


A description of  personnel  positions  at sludge landfills and an  overview
of personnel requirements was described earlier in  Chapter  6  (Operation).
The most  prevalent  position at  sludge landfills  is  that  of  equipment
operator.   For  most sites,  the  number  of  personnel will be  equal  to  or
less  than  the  number  of  machines.    Often   one  person  can  be  used  to
                                    9-5

-------
                                  FIGURE  9-1

                         EQUIPMENT INSPECTION  FORM  [1]
                   Site:
                   Machine:

                   Date:
                   Completed By:
                   Hour Meter Reading:
                    BEFORE STARTING CHECK
                      WATER  Q  	
                      F.NG. OIL D  	
                      TRANS.  Q  	
                      PU£L  g  	

                      WATES ADDED MONT   Q
                      ENG.OIL ADDED FRONT Q
                      TRANS.OIL ADDED FRONT Q
                      HYDRAULIC OIL ADDED  t-i
                       FRONT         U
                    AFTER STARTING LEVEL MACHINE AND CHECK
            WATER ADDED REAR   O
           " ENG.OIL ADDED REAR  O
           " T«AN5.OIL ADDED REAR Q
            FINAL DRIVE OIL    r]
ENGINE OIL
TRANS.
HYDRAULIC OIL
ANY LEAKS
BRAKES
STEERING
TRANSMISSION
PRESSURE
GAUGES
SHIFTING
ENGINE
TEMP.
OIL PRESSURE
WATER TEMP.
UNDERCARRIAGE
TRACK ADJUST.
ROLLER WEAR
TIRES
BLADE
CUTTING EDGES
TRUNNIONS
HYDRAULICS
PUMP
JACKS
OTHER
AIR CLEANERS
RAD. CLEAN
TRACK CLEAN
TIRES FREE OF MU
Q
D
n
D
n
n
Q
a
n
Q
a
a
n

o
a
n
Q
a
n
Q
D
i~l
a
a
n
n

ID ^
operate two  or more machines  (since  100%  utilization of all  equipment is
often not  required).   For the larger sites, especially codisposal  sites,
the  number  of personnel  may exceed the  number  of equipment  pieces.   These
surplus  personnel   may  be on-site  superintendents,  equipment  mechanics,
laborers, or check  station
         superintendents,
attendants.
                                         9-6

-------
Hiring should be done in compliance with equal employment opportunity  and
nondiscrimination-in-hiring practices.  When considering an applicant  for
a position, these procedures should be followed:


     1.  The applicant should complete an employment application form.

     2.  Supervisors  should personally  interview  each  applicant.    The
         applicant  should  be  questioned  closely  on  past  work experience
         to determine  qualifications.   The importance of  the job  should
         be  explained  fully  with  emphasis  on  the need  to  maintain a
         sanitary condition and to  prevent environmental  degradation.

     3.  The applicant's  past  employers and  character references  should
         be  checked  and   the  applicant's  reliability  and   work   record
         determined.   The  applicant's  statements  concerning experience
         and qualifications should  be verified.  Tests  to  determine  the
         applicant's ability to perform the work  are highly desirable.

     4.  If a decision  is  made to  hire, arrangements  should  be made  for
         the applicant to  be given  a thorough physical examination.


These  hiring  practices  will   help  achieve   a   high  standard  for   new
employees.


     9.4.2  Training
New employees  should  not only  learn  the tasks  required  for their  posi-
tions,  but  also  understand  the  purposes and  importance of  the  sludge
landfill ing operation.   Except  for  the largest operations,  comprehensive
training programs are  not likely  to  be designed or conducted by  landfill
management.  Training Programs  have been  prepared for refuse landfills by
the  U.S.  Environmental  Protection  Agency,   the  American  Public   Works
Association, and  various educational  institutions  [1][2][3].  Since many
of the  procedures employed  at  refuse  landfills  are  similar  or identical
to those  employed  at  sludge  landfills, these  programs   can  be  useful.
Programs may take the  form of  classes  conducted by these  agencies  or the
provision of guideline  information  for training activities conducted for
the employees.   Equipment manufacturers  are  another valuable  source of
information on training procedures.
     9.4.3  Safety


Managers  of  sludge landfill  operations have  an  obligation  to maintain
safe and secure working conditions for all landfill personnel and also to
                                   9-7

-------
see to  it that  safety  rules are  written,  published, and  given  to  each
employee.


The  landfill  manager  should  establish  a  safety  training  program  and
should express,  by  example, a commitment to  that  program.   Ideally,  one
man  should  be  assigned   the  task  of  conducting  the  program   and  in
assessing  the  compliance  and efficacy  of the program.   A supervisor  or
foreman, because of  his proximity to the operation is the  logical  choice
for this position.


A  safety  checklist  prepared  by the  National   Solid  Waste  Management
Association has  been included as  Figure 9-2.  Although this checklist was
prepared  for municipal  refuse landfills, most of  the items  are  relevant
to sludge  landfill operations.


Privately  operated   landfills  are required  by  Federal   law  to  maintain
up-to-date Occupational Safety  and Health Act (OSHA)  form  records  and  to
post the  current OSHA  employment  poster.  When  an  inspection  is made  of
the landfill, the  inspector will  request to  see  all  of the  OSHA  record-
keeping  forms.   If  they are not  up  to date,  it  can result in  a  citation
and fines.  Any  records on  safety meetings and preventive maintenance,  as
well as  posters  and  brochures,  will  be  considered  by an  inspector  as  an
act  of  good faith  and will  indicate that  an  effort is  being  made  to
comply.
9.5  General Management  and  Recordkeeping
In  addition  to direction  of  equipment  and   personnel,  a  manager  has
numerous  other  responsibilities which must be  performed to  ensure  a safe
and  efficient  operation.    These   include  the  completion  of  activity
records,  the  evaluation  of  operational  performance, on-site  supervision,
public relations,  and  security.   More details  on  these  tasks are  outlined
below.
     9.5.1  Activity  Records
Complete  records  of  the  activity  at  sludge  landfills  may be needed  either
(1) to compile  waste receipt records for billing purposes;  (2)  to  assess
the rate  of  cover utilization  for future  stockpiling  needs; and/or  (3) to
gauge  the overall efficiency  of  the landfill.   Figure  9-3  is a  sample
form which  could  be  used to record  the  quantity of  sludge  received  from
each  incoming  truck  on  a  single  day.   If  this  information  is  available
from  the  wastewater  treatment  plant, that  data  may  be  used.   The  daily
sludge  quantity  can be  totaled   at  the  bottom of  the  daily  form  and
                                    9-8

-------
         FIGURE 9-2
LANDFILL SAFETY CHECKLIST [2]







c






























- —























1.
2.
3.
4.
5.
6.
BUILDING EXITS (OSHA 1910.35 - 1910.37)
Doors swing with exit travel
Marked with lighted signi
Not locked so that they may be used From the inside at all times
Keep free of obstructions
Non-exit doors which can be mistaken as an exit as an exit are marked "No Exit"
Single exits are allowed for rooms containing less than 25 people


ombustible, Oxidizing, and Flammable Agents, When Using (OSHA 1910. 101 -1910. 1 16)
7.
8.
9.
10.
11.
12.

13.
U.
15.
16.
17.
18.
Electrical installation and static electricity are controlled or maintained
Heating appliances are controlled or maintained in a safe manner
"Hot" work (welding) controlled or maintained in a safe manner
At least one 20 pound Gloss B fire extinguisher is within 25 fe«t of a storage area
ICC approved metal drums are used for storage from 5-60 gallons
Not more than required for one do/ or shift stored outside storage cabinet
COMPRESSED AND LIQUIFIE& GASES (OSHA 1916.101-1910. 1 16)
Charged and empty cylinders ore separated
Cylinders are grouped by type and stored in vertical positions
Cylinders ore not stored near other combustible material
Cylinders are supported so that they cannot be tipped over
Cylinder caps are in place on all cylinders which are not in use
Oxygen cylinders are not stored within 20 feet of other types of gases



DRAINAGE
19.
20.

21.
22.
23.
24.
25.
26.
27.

28.
29.
Drains are vented to prevent collection of combustible gases
Grease and oil prevented from entering public sewage systems
ELE^TftiCAI. EQUIPMENT (OSHA 1*10.308-1*10. 3<») '
All outlet and junction boxes are properly covered
All portable electrical tools and appliances are properly grounded
Records maintained for inspection or portable electrical tools and appliances
Electrical cabinet doors with exposed conductors of 50 volts or more are securely fastened
Enclosures around high voltage electrical equipment ore marked
Frayed cords, cobles, and loose wires regularly removed from service
Switch boxes ore identified as to equipment they control
EMERGENCY LIGHTING
Exit signs are illuminated to at least 5 foot candles





FIRE EXTINGUISHER EQUIPMENT (OSHA 1910.157)
30.
31.
32.
33.
34.
35.
36.

37.
38.
39.

40.
41.
42.
43.
44.

45.
46.
47.
48.
49.

50.
51.
5?

	
—

—












33.
54.
55.
56.
57.

58.
59.
60.
61.
62.
63.
64.
65.
66.

67.
68.
69.
70.
71.
Extinguishers are inspected monthly for physical damage
Inspection records ore kept indicating inspector
Maintenance performed yearly; hydrotested every 5 years, if required
Inspection togs marked by month and year
Extinguishers conspicuously installed and properly marked for use by type of Fire (A,B,CorD)
The top of portable extinguishers (less than 40 Ibs) mounted no more than 5* above the floor
The top of portable extinguishers (40 Ibs or more) mounted no more than 3-1/2' above the floor
FIRST AID (OSHA 1910.151)

An approved first aid kit is available
Emergency numbers of company-approved doctors and hospitals posted in appropriate locations
Trained personnel available
HAND AND PORTABLE TOOLS (OSHA 1910.241-1910.247)
All useable tools have guards properly installed
All portable electrical tools are tested monthly for ground
Records kept of inspection (item 41)
Atl tools in safe operating condition are free from worn or defective parts
Jocks and hoists are legibly marked with the load rating
HOUSEKEEPING
Material on walls/shelves stored in a safe and orderly manner
Facility is in a clean, orderly, and sanitary condition
Hoses, welding leads, drop lights, etc. ore rolled and properly stored
Permanent aisles and passageways are Free of obstructions
Permanent aisles and passageways are permanently marked
ILLUMINATION
Sufficient quantity (20 foot candles or greater)
Uniform distribution
W.I! H;r»<-t«d
INDUSTRIAL SANITATION (OSHA 1910.14]']
Clean, available drinking fountains
Facilities ore maintained in o clean and stocked condition
Hot water available
Individual towels and drinking cups available
Toilet facilities ore within 200 feet of working area for each sex
INDUSTRIAL TRUCK- FORKLIFT (OSHA 1910.178)
Brakes in good operating condition
Guord behind fork is in place (to guard from load falling to the rear)
Load capacity of truck marked
No one except operator permitted to ride
No one stands or walks under raised Forks
Overhead guard to protect against foiling objects
Recharging/reFueling done in a "No Smoking" isolated area
Training program for operators
Warning devices (horn) working
LADDERS (OSHA 1910.25-1910.28)
Anti-slip safety steps used on portable ladders
Caution exercised when metal ladders used in electric current areas
Caution exercised when metal ladders used with portable electric tools
Ladders inspected monthly with inspection records kept
Straight ladders properly secured












              9-9

-------
                  FIGURE   9-2   (Continued)
                  UQU!D PETROL£UM~
	LKjJUMJI  rEIKULCU/V OAaE^fOSHA 191IX I 10)	
 72.   Bulk  storage (126 to 500 gallons) at least  10 feet from building
 73.   Bulk  storage (501 to 2,000 gallons) at least  25 feet from building
 74.   Bulk  storage (251 to 2,000 gallons) at least  three feet separation between  tanks
 75.   Containers  labeled by size (in  pounds or gallon^
 76.   Containers  labeled with pressure in "gauge psi"
 77.   Containers  labeled by type of  L.P.G.
 78.   Containers  have safety relief and shut-off  valves
 79.   Containers  stored away  from exits
 80.   Distance  between C.P.G. containers and  flammable liquid containers  is 20  feet
 81.   No  containers are stacked  one above the other
 82.   Container!  ore  stored in a  "No Smoking"  area
               MACHINE  GUARDING (OSHA 1910.211-1910.222)
 83 ~Abrasive  wheels in  accordance with type  of  work
 84.   Abrasive  wheels In  good condition
 85.   Abrasive  wheels labeled and  in accordance with rpm ratings
 86.   Abrasive  wheels uniform In diameters
 8~.   Air  nozzles used  for cleaning meet 30 psl  limit
 88.   AH rotating, cutting shearing, screw and worm,  blending, and forming motions guarded
 89.   Safety  precautions understood and  used  by  shop employees
 90.   Steady rests on grinders meet^l/8"  adjustment  to wheel  requirement	
    PERSONAL PROTECTIVE EQUIPMENT  (OSHA  1910.95,  1910.132-1910.140)
 91.   All  protective equipment maintained in safe  working condition
 92.   Ear  protection worn  when noise dBA greater  than 90 for 8 hours
 93.   Ear  protection worn  when noise dBA greater  than 95 for 4 hours
 94.   Ear  protection worn  when noise dBA greater  than  100 for 2  hours
 95.   Ear  protection worn  when noise dBA greater  than  105 far 1  hour
 96.   Ear  protection worn  when noise dBA greater  than  110 for 1/2 hour
 97.   Ear  protection worn  when noise dBA greater  than  115 for 1/4 hour
 98.   Eye ond  face protection provided where  reasonable probability of injury  exists
 99.   Respiratory protective equipment worn when  air It contaminated  (dust,  gases,  etc.)
 1 DO.   Safety  shoes, caps,  gloves worn when necessary	
                        STAIRS (OSHA 1910.21-1910.24)
       Angle  of rise is between 30 to 50  degrees
       Fixed stairs have at least a 22" width
       Fixed stairs have at least a 1000  fbs.  load strength
       Non-slip treads are  present
       Stair railings are 30-34" from top  rail surface  to forward edge of step
       Stairways less  than  44"  wide (both sides enclosed)  have at  least one  handrail
       Stairways less  than  44"  wide 'one side  open) have at least one  stair  railing on open side
       Stairways over  44"  wide (both  sides open)  have two  railings
       Standard  railings  are 42"  nominally from top surface of floor
       Wood railing posts  at least 2"  x 4" stock  spaced  not  to exceed 6 feet
       Pipe railings and posts at least 1-1/2"  nominal diameter
       Pipe railing posts spaced not to exceed 8  feet
       Structural steet railings end posts  at 'east  2" x 2"
       Structural steel railing posts  spaced not^o exceed  8 feet	j	
                         VENTILATION  (OS'HA  1910.94)              	
 115.  Exhouit system  fo^ removal oF  toxic fumes  and dust  from work area
           WALKING, WORKING  SURFACES (OSHA  1910.21-1910.32)
 116.  Aisles ond passageways unobstructed
 117.  Permanent  walkways marked
 118.  Floor hole openings guarded  and marked
 119.  Floor surfaces in good condition and uncluttered
    WELDING, CUTTING,  HEATING  OR  BRAZING  (OSHA 1910.251-1910.254)	
 120.  Acetylene  not  used  at pressures greater  than  15'p$Tg
 121.  Eye profecfion worn, where  required by extant of hazard
 122.  During welding operations,  oporeclable  combustibles more than 35 feet away
 123.  During welding operations,  floor swept clean of combustibles within 35 feet
 124.  Fire watch practiced,  where necessary
 125.  Frame cf electric welding machine grounded
                  HEAVY  EQUIPMENT SAFETY REQUIREMENTS
       Each piece of  equipment has roll-over protection (see  Section  X-"Rotl Over Protection
       Schedule")
       Each p'ece of  equipment has fire extinguisher (20 Ibs. ABC Minimum)
       All  heavy  equipment is  equipped  with backup alarm
       All  machines operating at night equipped  with  headlights
       Seat belts  ore  onfall equipment with  roll-over  protection
126.

127.
128.
129.
130.
                            MEDICAL AND FIRST AID
~T3~T.   MedTcol persofinet  available for  advice  and consultation
  132.   Suitable place to render  first aid
                        _ ROADS
  133.   Adjacent road  (City,  State, etc.Hs clear of debris and mud
  134.   Where possible,  warning  sign or light, "TRUCK ENTRANCE"
  135.   Landfill  rood crowned and  proper drainage
  136.   Landfill  road  kept properly cleaned of debris
  137.   Landfill  rood  has proper  dust control by means of a water wagon or water truck
  138.   Traffic  Control  Signs  (Landfill)  - Stop  sign (For vehicle leaving landfill  before
        entering public street)
  139.   Traffic  Control  Signs  (Landfill)  - Speed limit  signs
  140.   Traffic  Control  Signs  /Landfill)  - No  parking  signs  _ _
                                  LANDFILL SITE
        All u nd erg round cables, p"ip es , etc., a re ~ clearl y
                                                        rk ec( a^id  rdentTfi ed~
                            fficient height to  allow  clearance  for all  equipment
  141 .
  142.
       Utility wires are of
       landfill
       Security  fences  and landfill  s[te
                                          kept  free as -possible of blowing paper and debris
                                        9-10

-------
                                FIGURE 9-3

                          DAILY  WASTE RECEIPT  FORM
Truck
Ident.
























Totals
Time*

























Sludge
Sourcet

























Type-t

























SI udge
Weight
or
Volume

























                    Instructions:
                              To be completed for each truck, each
                              time it makes a delivery.
                      Only record time at 15-minute intervals
                      Sources:  Code for Contributing Treatment Plant
                      Types: G = grit; DI = digested; CT = chemically
                           treated
transferred to the  monthly  summary included  as Figure  9-4.
summary  can be  used to  record the  sludge  quantity  received
cover  soil  utilization,  personnel  and machine hours,  and
expenses.
  The monthly
   as  well  as
miscellaneous
      9.5.2  Performance  Evaluation
Generally,  a state  or local  regulatory agency  determines  if  the landfill
operation  is  being  conducted  in  a  manner  that adequately  protects the
environment.  The concern  of the landfill  management, whether publicly  or
privately   operated,   helps  guarantee  an  effective  operation.     The
management  of the organization operating  the landfill should  periodically
evaluate  the operation.   The operating  and supervisory personnel  should
be  aware that  these  evaluations  will  be  made,  but the  specific   dates
should  not  be made  known  in advance.
                                      9-11

-------
                                FIGURE 9-4

                            MONTHLY  ACTIVITY FORM
            Site:

            Month:
            Completed By:
Day
1
2
3
4
5
6
7
e
9
10
11
12
13
U
15
16
"
c
Sludge
Loads


















,9
20
21
22
23
24
23
26
27
28








29
3C
31
Totals

Tom!
































Cover material
Begin
































Rec'd
































Us*d
































Remain
































Man
hn.
































Machine
hrs.
Use
































Dawn
































Exoe-*e
S (TVoe
































































Site
hn.







1
























             1 ton = 0.907 Mg
     9.5.3   On-Site Supervision
For  safety  reasons, it is desirable  to have two  or more persons  working
at sludge landfills.   This can easily  be  accomplished at large  landfills
where more  than  one person is needed  for daily operation.  On  small  sites
requiring only  one  operator, a second  person  should visit the site  daily
or the  single  operator should phone  or check  in at  the  end  of  each  day.
At a  large  site a  foreman may be  required with  appropriate echelons  of
subordinate   supervisors.     A   multishift   operation  would    require
                                    9-12

-------
supervisors  for each  of  the shifts as  well  as an  overall  manager.   No
matter  what  the size of the  operation,  one person should be  responsible
for  safety  during operating  hours  and  be familiar with  OSHA  regulations
and  procedures.
     9.5.4  Public  Relations


As  noted  in Chapter  4  (Public Participation  Program), sludge  landfills
can  be  an emotional  issue  among  the citizenry, especially those  persons
living  in the vicinity  of  the  site.   Good  housekeeping  practices,  such  as
control  of  odors  (via  prompt  application  of  cover  to  sludge  and  spot
application of  lime to  sludge  spills)  as well  as  other  efforts to  protect
the   environment,   are   important   in    gaining   public    acceptance.


Other public  relation techniques that  may  be employed  are periodic  news
releases  concerning the progress  of the  fill,  citizen participation  in
the  completed   site design, encouraging public  visits  to  the site, and
establishing a  mechanism for handling  complaints  from the  public.


9.6  Cost Recordkeeping
A  primary  duty of sludge  landfill  management  is to  control  costs.   Ef-
fective  cost  control  requires timely  recognition  of excessive costs  and
the  identification  of the reason  for  such  cost overruns. The  increasing
costs  and  complexities  of sludge  landfill  operations require the  use  of
more  sophisticated  cost control  tools  than have been  used  in the  past.
Use of cost  accounting  systems at  landfills are recommended  in order  for
management to control costs.
Because user fees are generally not charged at  sludge  landfills  (reducing
the  need  for accountability)  and  sludge landfills  are  usually  adminis-
tered by sewer departments  and as  such  are  not   separate enterprises,  but
merely  a  secondary  facet  of a  larger  operation,  cost  records  at most
sludge landfills are either  non-existent or poorly maintained.
The  installation  of a  cost  accounting system  has  several  benefits,  in-
cluding [4]:
        The  system facilitates  orderly  and  efficient  accumulation  and
        transmission  of  relevant  data.  Much  of  the recommended data  is
        already being  collected  or should be.  Hence,  the added cost  of
        installing the system is minimal.
                                   9-13

-------
    2.  The data  can  be grouped in  standard  accounting classifications.
        This  simplifies interpretation  of results  and  comparison  with
        data from previous years or other operations, and in turn, allows
        analysis of relative performance and operational changes.

    3.  The system can account for all relevant costs of construction and
        operation.

    4.  Accumulated data from the system can, over a period of time, lead
        to  standards  of performance  and  efficiency  that can  be  used to
        control costs by indicating  which  costs  are  high and the reasons
        for these  costs.   The  supervisor of  operations may  then  take
        corrective action.

    5.  The  system  includes   automatic  provisions  for  accountability.
        Cost control  becomes  more  effective when  the  individual  respon-
        sible for cost  increases can  be ascertained.

    6.  Use of the collected  data  aids  in short- and  long-range fore-
        casting of  capital  and  operating  budgets.   Future requirements
        for equipment, manpower, cash, etc., can be accurately estimated.
        This,  in  turn,  aids planning  at  all  levels of  management.   The
        data is also available for later evaluation and analysis.

    7.  The system  can  be  flexible  enough to meet  the  varying require-
        ments  of  sludge  landfills,   of  different  sludge  quantities  and
        types, site conditions, and landfill ing methods.


Generally  landfill  costs   can  be  categorized  into  capital  costs  and
operating costs.   For the  purposes  of the accounting  system recommended
herein,  capital  costs are  meant  to   include  all  non-recoverable initial
expenses  required  prior  to the  start-up   of  operation.    Capital  costs
usually  include:


    1.   Land
    2.   Planning and design
    3.   Site preparation (i.e., clearing and  grubbing, road  construction,
         surface water/1eachate controls, soil  stockpiles, monitoring)
    4.   Facilities (i.e., offices, personnel  shelters, garages, etc.)
    5.   Equipment purchase


Operating costs  are  expenses  incurred during the on-going  operation of
the landfill and usually include:
    1.  Equipment fuel
    2.  Equipment maintenance  and  parts
                                    9-14

-------
     3.   Office/trailer  rental
     4.   Supplies  and materials
     5.   Utilities   (i.e.,  electricity,  heating   oil,  water,  sewer,  gas,
          telephone,  etc.)
     6.   Laboratory  analyses
     7.   On-going  inspection  and engineering


Costs  may  be  computed  on  the  basis  of  wet  tons,   dry  tons,   and  cubic
yards.   Forms  for  compiling  total  and  unit  capital  and  operating  costs
based  on wet  tons have  been  included  as  Figures 9-5  and  9-6.
                                    FIGURE 9-5

                                 CAPITAL  COST  FORM
                 (Area  Fill  Mound  Receiving  500 wet tons/day)
                                      Quantity
                                                 Unit Cost
                                                              Total Cost
             Land

             Site Preparation
               Clearing and grubbing
               Sodded diversion ditch
               Sodded runoff ditch
               Pond
               Mom tori ng wel 1 s
               Soil stockpiles
               Garage (40 x 80)
               Gravel Roads
               Asphalt Roads
               Miscellaneous
                                        200 ac
    100 ac
   6,261 ft
   6,261 ft
      7
      4
1,247,083 yd3
   3,200 ft2
   4,500 ft
    750 ft
               15T

              2,500/ac
 705/ac
 2.50/LF
 2.50/LF
7,500/ea
 300/ea
 2.55/yd3
15.00/ft2
 1.85/LF
 3.35/LF
                1JT

              500,000
 70,500
 15,652
 15,652
 52,500
  1 ,200
,180,062
 48,000
  8,325
  2,512
Equipment
Cat D-4 dozer
Cat D-6 dozer
Cat 941 track loader
Cat 955 track loader
Cat 930 wheel loader
Cat 621 scraper
Cat 930 backhoe
Subtotal
Engineering & 61,
TOTAL
Amortized @ 7% for 5 years

1 41,760
1 60,020
1 39,680
1 52,730
1 36,972
1 144,250
1 46,955



41 ,760
60,620
39,680
52,730
36,972
144,250
46,955
4,317,370
259,042
4,576,412
1,116,141
             Total Annualized Cost
                                         $1,116,141 t 182,500 tons = $6.12/wet ton
             1  ton = 0.907 Mg
             1  ac = 0.405 ha
                                          9-15

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                                  FIGURE  9-6

                              OPERATING  COST FORM
                (Area Fill  Mound Receiving 500 wet tons/day)
                                    quantity
                                    (per year)
                             Unit Cost
                                         Total Cost
                                                             TIT
             Labor (10 men)

             Equipment Fuel, Maintenance
              4 Parts
              1 - Cat D-4 dozer
              1 - Cat D-6 dozer
              t - Cat 941 track loader
              1 - Cat 955 track loader
              1 - Cat 930 wheel loader
              1 - Cat 621 scraper
              1 - Cat 930 backhoe

             Office Trailer Rental

             Utilities

             Lab Analyses

             Supplles 4 Materials

             Engineering

             Mi seellaneous
                  29,200 M-H
                  2,920 hrs
                  1,460 hrs
                  2,190 hrs
                  2,920 hrs
                  2,190 hrs
                  1,460 hrs
                  2,920 hrs

                     3 ea
 3.00/hr
 4.50/hr
 8.37/hr
 5.45/hr
 8.98/hr
 7.35/hr
21.88/hr
 8.15/hr

3,720/ea
233,600
 13,140
 12,220
 11 ,935
 26,222
 16,096
 31 ,945
 23,798

 11 ,160

 15,000

  6,000

 50,000
                                                             20,000
             TOTAL
                                       $471,116 t 182,500 tons = $2.58/wet ton
             1 ton = 0.907 Mg
      9.7  Financing
The  management  of  a  sludge landfill  involves two
sions:   (1)  How  should the  capital  requirements  be
should  the  operating  costs  be financed?   These
                                        basic  financial  deci-
                                        financed?  and  (2) How
                                     decisions  are influenced
largely  by  whether  the   landfill
Certain  methods  of  financing  are
general  funds,  general  obligation
increases  or   special  assessments
methods of  financing  are available
                       is  a  public  or  private  operation.
                      available  only  to  public  operations:
                      borrowing,  revenue  bonds,  sewer  rate
                     ,  and  grants  and   subsidies.     Other
                      to both  public  and private operations:
loans and  user
follows below.
fees.   A  description  of each of  these  financing  methods
      9.7.1   General  Funds
The  general  fund  is  derived  from  taxes.   Although  it  normally  cannot
provide enough money  to  meet  capital  costs,  it  is  often  used  to  pay for
                                        9-16

-------
operating  expenses  [3],   There are  advantages  to using the  general  fund
for  this  purpose.    The  administrative  procedures  and  extra  cost  of
billing  and collecting fees  from  contributing treatment plant authorities
are eliminated.   Using  general  funds for  sludge  landfills  does,  however,
have disadvantages.   Cost  accounting and other administrative  procedures
may be  so  relaxed that  disposal   costs  may be  difficult or  impossible  to
determine.    It   may  also  be extremely  difficult  for  sludge  landfill
operations to get money from  the  general  fund because  of the low  priority
often assigned to them.


     9.7.2  General Obligation Borrowing


General  obligation  borrowing  is one  method  of financing the  capital  costs
of a sludge landfill.  This  type  of  bond  generally carries  a low  interest
rate but is easily  marketed  because it  is  secured  by  the  pledge  of  real
estate  taxes   and  because  all  of  the  real  estate  within  the  taxing
district  serves   as  security  for the  borrowed  funds.   State  statutes
usually  limit the amount  of  debt  a  community can  incur.  If the  debt  is
already  substantial,  this  method  may  not be available.   In some  cases,
general  obligation bonds  are  retired  with revenues   generated  by  the
sludge  landfill;  this minimizes   the ad  valorem taxes   necessary  for  bond
retirement.
     9.7.3  Revenue Bonds
Revenue  bonds differ  from  general  obligation  bonds  in that  they  are
secured  only  by the  ability of  the  project  to  earn enough  to pay  the
interest and  principals.   In  this case,  fees must be charged  to  users  of
the  sludge  landfill   in   amounts necessary to  cover  all   capital   and
operating expenses.   Fees should be high  enough  to accumulate  a  surplus
over and above debt  service needs in order  to make the  bonds  attractive
to  prospective  purchasers.   This method of  financing  requires that  the
administering  agency  follow good  cost  accounting  procedures,  and  it
allows the  agency  to  be the  sole beneficiary of  cost saving  procedures.
In  addition,  sewer authorities  contributing sludge to  the  landfill  are
forced to pay the true cost of its disposal.


     9.7.4  Sewer Rate Increases  or Special  Assessments
When the  sludge  landfill  is  owned  and operated  by  the sewer  authority,
sewer  rate  increases  or  special  assessments  are  the usual  method  of
financing  both  the  capital   and  operating costs  of  the  facility.    If
strong opposition  at a local  level  arises due  to  proposed   increases  in
sewer  rates  or  special  assessments, a  public  education program might  be
in order to gain support for  the additional charge.
                                    9-17

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     9.7.5  Grants or Subsidies
Sludge management  systems  may be eligible for various Federal,  state,  or
local funding.   Sludge landfills are often  eligible  for grants from  the
EPA  Construction  Grants  Program  administered  by the  Office  of  Water
Program Operations.   These  grants  may cover a significant portion  (up  to
75%)  of  the  capital   fundings  for the  entire  sludge  management  system
including land  acquisition,  equipment  purchase, and site preparation  [5].
In  codisposal   sites,  or  in  sites that  handle  industrial  sludges,  the
amount of funding  will  be  prorated based  on what percentage of  the  total
waste processed  at  the site is  municipal  sludge. The funding  received  in
grants or subsidies is  generally for  the  entire  sludge management  system,
including  sludge processing  systems  at  the  treatment   plant  as well  as
disposal   systems.   All  of  the  operating  costs  and some  of the  capital
costs must be  financed from other  sources.  Despite the large  percentage
of  the total  cost  which may  remain  after grants  or  subsidies  have  been
exhausted,  this  contribution   may  be   essential   in   enabling   local
governments to  finance  such systems as  they  become  even  more costly.
     9.7.6  Loans
Loans  from  commercial  institutions are often used to finance  the  capital
costs  of constructing  sludge landfills.   Thereafter,  user  fees  can  be
used  to  accommodate operating  costs  and  to  gradually  pay  off the  debt
incurred  in   construction.     Accordingly,  user  fees  should   be   set
sufficiently  high  to  pay operating  costs  and  to  repay  the  loan.    In
addition,  a portion of user  fees  should  be  set  aside to  help  finance
the  ultimate   use  of the  site  and also  capital  construction of  future
sludge landfill  sites.
     9.7.7  User  Fees
When  the  sludge landfill  is  privately  owned  and operated, user  fees  are
the  normal  financing method.   The  private operation charges the  contri-
buting  sewer authority for  disposing sludge.   Alternatively,  user  fees
might be  employed  by a  publicly owned and operated  landfill  if more  than
one  sewer  authority  contributes  sludge.    Sometimes,  user   fees   are
employed  when the  landfill   is  publicly  owned  and  receives  sludge  from
only  one   sewer   authority.   For   example,   a  public   works  department
operating  a  sludge  landfill  may  choose  to  finance   its  operation  by
charging  the  sewer department for the sludge  disposed.
User  fees  are  primarily  a  source  of operating  revenue,  but  a municipality
might   also   employ   them   to   generate   funds   for   future   capital
                                    9-18

-------
expenditures  such  as preparing  the  final  site  and/or purchasing  future
sites.  However, it  should  be  noted  that fees do not  usually  provide  the
capital outlay needed to start a sludge  landfill.
Although  fees  necessitate  a  greater management  expense due  to  the  in-
creased  recordkeeping  required, these  records provide  a  basis  for  cost
conscious management and  operation  of the  landfill.
9.8  Typical Costs
This  section  presents  typical  costs for  sludge  hauling and  landfilling.
Cost  curves  are  presented  in  terms  of  cost  per  wet  ton  vs.   sludge
quantity  received.   Typical  costs  are  presented  for (1) sludge hauling,
(2)  annualized  site  capital  costs,  (3)   site  operating costs,  and  (4)
total site  costs (combined annual ized capital  and  operating).


These  curves can  be  useful   in   the  early  stages  of  sludge  landfill
planning.   However,  typical  costs  should be  used only  in  preliminary
work.   Actual  costs  vary considerably  with  specific sludge  and  site
conditions.   Therefore,   use  of  these  curves  for computing  specific
project  costs  is  not  recommended.   Site-specific  cost   investigations
should be made  in each case.
     9.8.1  Hauling Costs
Typical  costs  for hauling  wastewater  treatment sludge  are  presented  in
Figure  9-7.    As  shown,  costs  are  given in  dollars per  wet ton  as  a
function of the wet tons of sludge delivered to the  site  each  day.   Costs
are presented  for alternative distances  of 5,  10, 20, 30,  40, and  50  mi
(8.0,  16.1, 32.2, 48.3, 64.4, and 80.4 km) hauls.


"Principals and  Design Criteria  for  Sewage  Sludge  Application  on  Land"
[6] and "Transport  of  Sewage Sludge"  [7] were  the  primary  sources  of
information for  data  and  procedures  in  developing  these hauling costs.
Other  references  [8][9][10] are  available and  were  also  consulted  and
utilized.   Sludge hauling  costs  were  originally prepared  for  the year
1975 but were  updated to reflect  1978 costs.
                                   9-19

-------
                            FIGURE  9-7

                      TYPICAL  HAULING  COSTS
  SOOOr

  4000-
  3000
S  1500 -
0  1000
^OMILE HAUL
    !E HAUL
   ILE HAUL
    £ HAUL
to MIL"E HAUL
   ~E HAUL
                              SLUDGE QUANTITY RECEIVED
                                 (WET TONS/OAY)
                                      9-20

-------
The  hauling costs  shown  in  Figure  9-7 reflect  not only  transportation
costs, but  also the cost  of  sludge loading  and  unloading  facilities.   For
a  plant  producing  approximately  10  wet tons  (9.1  Mg)  per  day  of a  de-
watered  sludge and  a 5-mi  (8.0-km)  haul, sludge  loading and  unloading
facilities  were found  to  contribute  60% of the total hauling costs.   For
a  plant  producing  approximately 250  wet  tons  (227  Mg)  per  day   of
dewatered  sludge  and  a  40   mi  (64.4  km)  haul,  loading  and   unloading
facilities  contributed less  than  10%  of the total  hauling  costs.
Because of the differing bases  for cost  computations,  certain  assumptions
on  sludge  volumes and  unit  costs were  utilized to  produce  the  hauling
cost curve.  These assumptions  include:


     1.  The   sludge  was   dewatered   and   had  a   solids   content   of
         approximately  20%.     It  was  hauled  by  a  15  yd3   (11.5  m3),
         3-axle dump truck.

     2.  Hauling was performed 8 hrs per day, 7  days  per  week.


     3.  Fuel cost was $0.60 per gal ($0.16 per  1).

     4.  Labor (primarily truck driving) cost were $8.00  per hr  including
         fringe benefits.

     5.  Overhead  and   administrative  costs  were  25%  of the  operating
         cost.

     6.  Capital  costs  were  annual ized.  A rate of 7% over 6 years was
         used for  the  trucks  with  a salvage value of  15%.   A  rate of  7%
         over 25 years was used for loading and  unloading  facilities with
         no salvage  value.


If  conditions  other  than the above-stated  conditions  prevail  at  a given
site,  the   hauling  costs  in  Figure   9-7  should  be  revised   upward   or
downward  appropriately.   As  an  example,  if   10  yd3  (7.6   nr)  2-axle
dump trucks are used,  costs should  be  higher  by factors ranging from 1.3
for a plant generating 250 wet tons (227 Mg)  per day with  a 50-mi  (80 km)
haul to  1.0  for  a plant generating  10 wet  tons (9.1  Mg)  per  day with a
5-mi (8.0  km)  haul.   Alternatively,  if  a  30  yd3  (23.9  m3)  dump truck
is used, costs should be lower by factors ranging from 0.6 to  1.0  for the
aforementioned sludge quantities and haul distances.
                                    9-21

-------
     9.8.2  Site Costs
Typical  site  costs  for  landfill ing  wastewater  treatment  sludges   are
presented  in  Figure  9-8, 9-9,  and  9-10.   As shown, costs  are given  in
dollars per wet  ton  of sludge received as a  function of the wet tons  of
sludge delivered  to  the  site each day.  Costs  are presented for each  of
the  alternative  landfill ing methods.   Scenarios  using  average  design
dimensions and  application  rates were devised  for the  purposes  of these
cos}:  calculations.   These  scenarios  are  summarized  in Table  9-1.   The
cqst  curve  for each method  was plotted from computations which assumed
alternative quantities of 10,  100,  and 500 wet  tons  (9.1, 90.7, and  453
Mg) of sludge for each scenario.


Capital  costs  are  summarized   in   Figure   9-8.    Capital  cost  items
included:
     1.  Land

     2.  Site  preparation  (clearing and  grubbing,  surface water  control
         ditches and ponds, monitoring wells,  soil  stockpiles,  roads,  and
         facil Hies)

     3.  Equipment  purchase

     4.  Engineering


Capital costs  were  then  annualized  at  7% interest over 5 years  (the  life
of the site)  and divided  by  the sludge quantity delivered to the  site  in
one year.
                                    9-22

-------
                                        FIGURE 9-8


                             TYPICAL  SITE  CAPITAL  COSTS
                                FOR SLUDGE  LANDFILLING
  5000



  4000




  30.00






  20.00
f?  1500
o>

a:
o
8
   10.00
5.00



4.00




3.00






2.00
    1.00
      10
                    20
                            30
                                  40   50
                                                  OO
                                    SLUDGE QUANTITY RECEIVED
                                          (WET TONS/DAY)
                                                                             CODISPOSAL WITH

                                                                                REFUSE
                                                                                   I
                                                                   200
                                                                           300   400  500
                                            9-23

-------
          FIGURE 9-9

TYPICAL SITE  OPERATING  COSTS
   FOR SLUDGE  LANDFILLING
        50
100
                                  200
300  400  500
      SLUDGE QUANTITY RECEIVED
          (WET TONS/DAY)
             9-24

-------
                                      FIGURE 9-10
                  TYPICAL TOTAL  SITE COSTS FOR SLUDGE  LANDFILLING
                       (COMBINED   CAPITAL AND OPERATING COSTS)
o
u.
o  10.00
tu
•in-
    1.00
                                                             zoo
                                                                     300   400 500
                                 SLUDGE QUANTITY RECEIVED
                                     (WET TONS/DAY)
                                        9-25

-------










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9-26

-------
Operating  costs  are  summarized  in  Figure  9-9.    Operating  cost   items
included:
     1.  Labor

     2.  Equipment fuel, maintenance and parts

     3.  Utilities

     4.  Laboratory analysis of water samples

     5.  Supplies and materials

     6.  Miscellaneous and other
Operating costs  (see  Figure 9-9) for  one  year were  then  divided by  the
annual sludge quantity delivered to the site.
The costs shown, which  were,  derived  from a variety of published  informa-
tion  sources  [11][12][13]  and   case   study   investigations,   have  been
revised upward to reflect  1978 prices.   Several assumptions were  employed
in producing these cost curves.  These  assumptions  include:

     1.  Life of the landfill site was  5 years

     2.  Land cost was $2,500 per acre  ($6,177 per  ha)

     3.  Actual fill  areas (including  inter-trench  spaces)  consumed 50%
         of the total site area

     4.  Engineering was 6% of the total capital cost

     5.  Operating labor cost $8.00  per hour  including fringe, overhead,
         and administration
                                    9-27

-------
It should  be noted that  the  site costs  shown  for codisposal  operations
were  derived  by  dividing  the  additional   annualized  capital  cost  and
additional operating  cost by the  sludge  quantity received.  Actual  unit
costs for  typical  refuse landfills  not  receiving sludge may  be  expected
to be less.
     9.8.3  Cost Analysis


As  stated  previously,   these  cost  curves  should  not   be   used   for
site-specific  cost  compilations performed during  design.    However,  they
can be  useful  in the  preliminary  planning  stages of  a specific  sludge
landfill.    In addition,  they  are  useful   in  developing  some  general
conclusions  about   sludge  landfill  costs.    For  instance,  cost  ranges
included:

     1.  Hauling costs ranged  from  $8.80  per wet ton  ($9.70  per Mg)  for a
         5-mi  (8.1-km)  haul  of 500  wet  tons  (453 Mg)  per  day  to  $34.00
         per wet ton ($37.49 per  Mg)  for  a 50-mi  (80.4-km)  haul  of 10 wet
         tons  (9.1  Mg) per day.

     2.  Annual ized site capital  costs  ranged  from  $2.20  per wet  ton
         ($2.43  per   Mg~)for   a   sTudge/ refuse  codisposal   operation
         receiving  500  wet  tons  (453  Mg)  per day to  $10.10 per  wet  ton
         ($11.11  per  Mg)  for  a diked  containment  operation  receiving  10
         wet tons (9.1 Mg) per day.

     3.  Site  operating  costs  ranged  from $1.20  per  wet  ton  ($1.32  per
         Mg]for  a  siudge/refuse codisposal   operation receiving  500  wet
         tons  (453  Mg) per day to $36.10 per  wet  ton  ($39.80 per Mg)  for
         an area fill mound  operation receiving 10 wet tons  (9.1  Mg)  per
         day.

     4.  Combined site costs ranged  from  $3.40 per wet ton  ($3.75 per Mg)
         for a sludge/refuse  codisposal  operation receiving 500  wet  tons
         (453  Mg)  per  day to  $46.20 per wet  ton  ($50.94  per Mg)  for  an
         area  fill  mound operation receiving  10  wet tons  (9.1  Mg)  per
         day.
Also,  an  assessment  can  be  made  of  the  relative  costs  of  alternative
landfilling methods.   A prioritized list of  landfilling methods  is  based
on  total  site  costs  (see  Figure  9-10)  with  lowest  costs  first  is  as
fol1ows :
     1.  Codisposal with  sludge/refuse  mixture
     2.  Wide trench
     3.  Codisposal with  siudge/soil  mixture
                                     9-28

-------
     4.  Narrow trench
     5.  Diked containment
     6.  Area fill layer
     7.  Area fill mound
The cost  of  a  landfill ing  method is determined  by  the efficiency of  the
operation in terms  of  manpower,  equipment,  and land use.  Other  factors,
such as haul distances  play a role in the  cost  effectiveness of a  given
site but  are the same for the various methods.
As  indicated,  codisposal  and  wide trench  methods tend  to  be  the  most
economical landfill ing  methods.   Codisposal  operations tend to be  larger
and benefit  from  the  economies of scale.   In addition, the  availability
of  "free"  bulking material  in  the form  of  refuse  reduces labor  costs.
Wide  trenches  have  high  application  rates  and  are  land  and   labor
efficient.   It  should  be noted however,  that the relatively high  solids
content required  for effective utilization  of wide trenches will  increase
the cost of  sludge handling at the treatment  plant.


Narrow  trenches  have relatively  higher  labor requirements  and  are  land
intensive, contributing  to  high  capital  and operating costs.  Area   fill
mounds, and  layers are  labor and  equipment  intensive.
Diked containment requires a relatively large operation  before  it becomes
a cost-effective means of  landfill ing.  This  is a result of high initial
labor and  equipment  requirements.   Once  established, however, diked  con-
tainments  are efficient  in terms of operation and  land use.
9.9  References

1.  Sanitary  Landfill,  Manual  of  Practice  No. 39.   American Society  of
    Civil   Engineers,   Environmental   Engineering  Division,  Management
    Committee.  1976.

2.  Refuse  Handling  Operations  Safety  Checklist,   Technical   Bulletin,
    National Solid Waste Management Association,  Vol. 4,  No.  8,  September
    1973.

3.  Brunner,  D.  R.  and D.  J.  Keller.   Sanitary  Landfill   Design  and
    Operation.  U.S. Environmental Protection  Agency.  1972.

4.  Zavsner,  E.  R.   An Accounting  System  for  Solid  Waste  Collection.
    U.S.  Department  of  Health,  Education,  and  Welfare,  Public  Health
    Service; Bureau of Solid Waste Management.  1970.

5.  R.   Bastian.   Municipal Sludge Management:   EPA  Construction  Grants
    Program.  U.S.  Environmental Protection Agency.  430/9-76-009.   April
    1976.
                                   9-29

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6.  Sommers,  L.  E., R.  C.  Fehrmann,  H.  L. Selznick,  and C.  E.  Pound.
    Principals and Design Criteria for Sewage Sludge Application on Land.
    Sludge  Treatment  and Disposal Seminar  Handout.   U.S. Environmental
    Protection Agency Technology Transfer.  May 1978.

7.  Clean  Water  Consultants,  Inc.    Transport  of  Sewage Sludge.   U.S.
    Environmental  Protection  AGency.    Cincinnati,  OH.    Contract  No.
    68-03-2186.  February 1976.

8.  Pound,  C.  E.,  R. W.  Crites,  and  D. A.  Griffes.   Costs of Wastewater
    Treatment  by Land Application.  Technical Report.  U.S. Environmental
    Protection Agency.  Washington, DC.  EPA-430-9-75-003.  June 1975.

9.  Los Agneles/Orange  County  Metropolitan  Area.   Sludge Processing and
    Disposal.   A  State-of-the-Art  Review.   Regional  Wastewater  Solids
    Management Program.  April  1977.

10. Spray   Waste,    Inc.      The  Agricultural    Economics   of   Sludge
    Fertilization.   East  Bay Municipal Utility  District  Soil Enrichment
    Study.  Davis, CA.  1974.

11. Equipment  Guide Book Company.  Green Guide, Volume I;  The Handbook of
    New and Used Construction Equipment Values.  1977.

12. Equipment  Guide Book Company.  Rental Rate Blue Book  for  Construction
    Equipment.  1976.

13. Robert  Snow  Means  Company,  Inc.   Building  Construction  Cost  Data
    1978.   1978.
                                     9-30

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                               CHAPTER 10

                             DESIGN EXAMPLES

10.1   Introduction
The  design  of  a  sludge landfill  is highly  dependent upon  many  sludge
characteristics  and site  conditions,  such  as percent  solids,  climate,
soil,  topography,  and  others.   Consequently,  no design  example can be
universal.    However,  examples  can  be  illustrative  of  the  design and
operating  procedures  which  have   been  recommended  in  the  preceding
chapters.


This  chapter  contains three  design  examples.   The  approach  in  each of
these  examples  is  to present sludge characteristics  and  site  conditions
as given  design  data.   The first example is  for  a large sludge  landfill
receiving 19%  solids sludge from a  municipal  wastewater  treatment  plant
serving  a  population  equivalent  of  200,000.    In  this  example,  the
landfill ing  method  is  selected  early  in  the design process,  and the
design  proceeds to  (1)  determine  design  dimensions, (2)  prepare  site
development  plans, (3) determine  equipment  and  personnel   requirements,
(4)  develop  operational  procedures,  and  (5)  estimate  costs.  The  second
example is for a sludge landfill receiving 29% solids  sludge  from  a  plant
serving  a  population  equivalent  of   50,000.    In   this   example,  two
alternative  landfill ing methods appear  to be  equally  suitable at  first.
Alternate designs  are performed  for  each  before one method is  selected on
the  basis of  costs.   The third  design  example  is  for  a  small   plant
serving a population equivalent  of only 5,000.  Plant  management  is  faced
with  a  choice  between  landfill ing their  34%   solids   sludge   at  the
treatment plant site or disposing it at an existing refuse landfill.
It should be  noted  that  the  scope of this chapter  is  confined to design
only;  i.e.,  it  is  assumed that  the  sites  in  the design  examples  have
already  been  selected.   An  example  of the  site  selection  process  was
given  in  Chapter 4, Site  Selection.    It  should  also  be  noted  that  the
design described  in  this chapter  is  somewhat preliminary  in  nature.   A
final  designs  should   contain  more  detail  and  address  other  design
considerations  (such  as  sediment  and  erosion controls,  roads,  leachate
controls, etc.) which are not fully addressed herein.
10.2  Design Example No. 1


     10.2.1  Statement of Problem
The  problem  was  to design  a  sludge-only landfill  at  the  location  of a
pre-selected  site.   As  stated  previously,  the  landfill  was  to receive
                                   10-1

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a 19% solids sludge from an existing municipal wastewater treatment plant
serving a  population  equivalent  of 200,000.   The  recommended  design had
to be  (1)  in compliance with  pertinent  regulations,  (2) environmentally
safe, and  (3) cost-effective.
     10.2.2  Design Data


The following information is included as given design data and was useful
in executing the subsequent design.


          10.2.2.1  Treatment Plant Description


The  wastewater  treatment  plant   was   a   secondary  treatment  facility.
Further information on the facility is  as  follows:


     1.  Service population equivalent  = 200,000
     2.  Average flow = 20 Mgal/d  (0.86 nvVsec)
     3.  Industrial inflow = 10% of total  inflow
     4.  Wastewater treatment processes:

         a.  bar screen separation
         b.  aerated grit tanks
         c.  primary settling tanks
         d.  secondary aeration tanks
         e.  secondary settling tanks


          10.2.2.2  Sludge Description


Sludge  was  generated  primarily by  two  sources  (primary  and  secondary
settling  tanks).   The  sludge  was  stabilized and  dewatered.    A  more
complete description is as follows:


     1.  Sludge  sources

         a.  primary settling tanks
         b.  secondary settling tnks

     2.  Sludge  treatment

         a.  gravity thickening
         b.  mixing
         c.  anaerobic digestion
         d.  vacuum filtration
                                   10-2

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     3.  Sludge characteristics (based on testing, review of records, and
         calculations)

         a.  Solids content = 19%
         b.  Quantity on a dry weight basis = 13.0 dry tons/day
                                              (11.8 Mg/day)

         c.  Quantity on a wet weight basis =  68.4 wet tons/day
                                               (62.0 Mg/day)

         d.  Density = 1,700 Ibs/yd3 (1,009 kg/m3)

         e.  Quantity on a wet volume basis = 80.5 ydVday
                                              (61.6 m3/day)
          10.2.2.3  Climate
Significant cl imatological factors having an impact on sludge landfill ing
are listed below:


     1.  Precipitation = 32 in./yr (81 cm/yr)
     2.  Evaporation = 28 in./yr (71  cm/yr)
     3.  Number of days minimum temperature 32°F (0°C) and below
                  = 60 days/yr
As  shown,  the  climate  was  relatively  mild  with  cold  temperatures
prevailing  approximately two  months  per  year.    Precipitation  exceeds
evaporation by 4 in./yr  (10 cm/yr).
          10.2.2.4  General Site Description
Preliminary data was collected during  the  site  selection  process.  It is
summarized below:


     1.  Size of property = 375 acre (152 ha)
     2.  Property line frontage:

         a.  5,200 ft (1,580 m) along county road
         b.  4,700 ft (1,430 m) along residences
         c.  4,600 ft (1,400 m) along grazing land
         d.  1,200 ft (370 m) along woodland
                                   10-3

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     3.  Slopes:  Uniform  slope of approximately  5%
     4.  Vegetation:

         a.  225 acres (91 ha) of woodland
         b.  150 acres (60 ha) of grassland

     5.  Surface water:  None on site
A plan view of the site  is  presented  in  Figure 10-1.  As shown, the  site
had  good  access  along  a  county  road.   The  site  was  located  in  a
moderately    developed    residential     area    and    abuts    residences.
Approximately 60% of the site  was  covered with woodland.  The  balance  of
the property had been used  for grazing and  remained  grass-covered.
          10.2.2.5  Hydrogeology


Eight  test  borings were  performed on  the site  to  determine  subsurface
conditions.   These were  located  as  shown in  Figure  10-1.    Subsurface
conditions  generally  were  similar at  all boring  locations  and  can  be
summarized as follows:
          Depth                            Description

        0-12 ft  (0-3.7 m)                  Silt  loam
       12-15 ft  (3.7-4.6 m)                Saturated  silt  loam
       >15 ft  (>4.6 m)                     Fractured  crystalline  rock


As can be  seen above, groundwater was determined to  be  at a depth of  12
ft (3.7 m)  and bedrock was at a depth of  15  ft  (4.6  m).  Samples of  the
silt  loam  were  collected  for analysis and  the  following determinations
made:

     1.  Texture = medium
     2.  Permeability = 2  x  10~4 cm/sec
     3.  Permeability class  = moderately  slow
     4.  pH =  6.5
     5.  Cation  exchange capacity  (CEC) =  18  meq/100  g
     10.2.3   Design


          10.2.3.1   Landfill ing  Method


Table  3-7  in Chapter 3  (Sludge  Characteristics and Landfill ing  Methods)
should be consulted  as  a reference.  Since  the sludge to be  received  is
                                   10-4

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           FIGURE 10-1
SITE  BASE MAP  FOR EXAMPLE NO.  1
                                         250 500 760 1000
                                         SCALE IN FEET
                   PASTURE
         LEGEND
	 PROPERTY BOUNDARY
=====  ROAD
    8     DWELLING
  -.f*$VV;  WOODS
200	 CONTOURS
                          BORING
                  10-5

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stabilized, it can be received by any of the five sludge-only landfill ing
methods shown in this table.   Also,  since  the  ground slope is  relatively
flat at 5%, any  of  these five methods are  suitable.   However, since  the
sludge has  a  solids content of  19%,  only  narrow trenches  and  area  fill
layers are  suitable operations.   Lastly,  since  groundwater  and bedrock
are relatively deep  (at 12 and  15 ft  (3.7 and 4.6  m),  respectively),  a
narrow trench operation should be employed.   Because the solids content
of  the  sludge is  between  15  and  20%, cover  application should  be  via
land-based  equipment  as  shown  in  Table  3-8.    Soil   should be   used
primarily for cover and  is  not required for bulking.


          10.2.3.2  Design  Dimensions


Table 5-5 in  Chapter 5  (Design)  should be consulted  as  a reference.  As
shown  in  this table,   the  design  dimensions  to be  determined  for  any
trench operation include the following:


     1.  Excavation depth              5.  Orientation
     2.  Spacing                       6.  Sludge fill depth
     3.  Width                         7.  Cover thickness
     4.  Length
The excavation  depth  is  determined initially by the depth to  groundwater
or bedrock.  A minimum separation  of 2 to  5  ft  (0.6 to 1.5 m)  is  usually
provided  between  sludge  deposits  and the  top  of bedrock or  groundwater.
In this case, a separation of 4  ft (1.2  m) was  selected.  The  soil  pH  of
6.5  means a  slightly higher  than  average  opportunity  for  contaminant
movement  since  contaminants move somewhat  more  readily  in an  acidic  soil.
However,  the permeability was classified as  "moderately slow"  and  the  CEC
was relatively  high  at  18 meq/100  g.   Thus, containment and  attenuation
were  seen  as  sufficient  with  a  4   ft   (1.2 m)  separation.     Since
groundwater is  at a depth of 12  ft (3.7 m) and  is  shallower  than bedrock,
a 4 ft (1.2 m)  separation dictates an excavation to 8 ft  (2.4  m).  Trench
spacing is determined chiefly  by sidewall  stability.   As a  general  rule,
1.0 to 1.5 ft (0.30 to 0.46 m)  of  spacing  provided  for  every 1  ft  (0.3  m)
of trench depth.  Since  the  soil type  was  found to be  relatively  stable,
1.0  ft  (0.3  m)  of  spacing  for  every  1   ft   (0.3 m)  of  trench  depth
was  suspected  to be  adequate  and   a total  spacing of  8 ft  (2.4  m) was
held.
Trench  width  is determined  by sludge solids  content  and equipment  con-
siderations.   Since the sludge  is  only  19% solids, a  2  to  3 ft  (0.6  to
0.9 m) width  should  be  used.'  Normally, when the  sludge solids  content  is
less  than  20%,  cover applied  atop  the  sludge would  sink to the  bottom.
However, at a width  of  2 to  3  ft  (0.6 to  0.9 m)  the cover soil  creates  a
bridging effect over the sludge  receiving  its support from  solid  ground
on  either   side of  the trench.    A backhoe  was  selected  as  the  most
                                   10-6

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efficient  piece  of equipment for  excavations  to an 8  ft (2.4 m)  depth.
Subsequently,  a  2  ft  (0.6 m) width  was  specified based  on  the  equipment
efficiency  of the backhoe.   The  length  for  narrow  trenches is  limited
only  by  the  need  to  place  containment  within the  trench  to  prevent
low-solids  sludge  from  flowing  to  one  end  of a trench.   Trench length  was
set  at 200 ft  (61 m).   Thus,  at every  200  ft  (61  m)  the trench  was
discontinued  for 5 ft  (1.5  m)  to  provide containment.   With regard  to
trench  orientation,  trenches should  be  kept  parallel  to one another  to
optimize  land utilization.  Because  of the relatively flat  slopes  at  the
site,  it  was  not found  necessary  to  orient  the  trenches  parallel   to
topographic contours.


As shown  in Table  5-5,  for trench  widths  between 2  and 3 ft  (0.6  and  0.9
m), the sludge fill depth should be  to within  1  to 2  ft  (0.3 to 0.6 m)  of
the ground  surface.   Because the  excavation  depth  is greater than  usual
for a  trench  of  this  width, it was  decided  that  sludge filling  should
proceed no  closer  than 2  ft  (0.6 m)  from the top.  Cover application  for
a 2 ft  (0.6 m) wide trench should  be from  2  to 3  ft  (0.6  to  0.9 m)  thick.
This thickness  was held  at  3 ft  (0.9 m) due to the  large  sludge fill
depth.
In  order  to  test  the  practicality   of   these   design   dimensions,   a
full-scale test was performed  at the  site.   Initially,  a backhoe  was  used
to  excavate two  parallel  trenches  at  the  previously-specified  depth,
width,  and  spacing.    A 10  yd3  (7.6   m3)  dump  truck (to  be  used  in
sludge  hauling) was  then fully  loaded  with  sludge and backed  up to  the
trench.   Since the  trench sidewall  withstood the  load,  the  prescribed
trench  depth, width,  and spacing were  found  to be sound.   Subsequently,
the sludge load was dumped  into  the  trench,  filling it to  a 6 ft  (1.8  m)
depth.  Three ft (0.9 m)  of cover was then gently  applied  over  the sludge
by the  backhoe.   The cover was  found to be  adequately supported at  the
time.   At  an  inspection  of   the  test   trenches  several   weeks  later  no
sludge  had emerged.  However,  the  cover had  settled almost 1 ft  (0.3  m).
Since  this  settlement  could  cause  ponding  of  rainwater  over   settled
trenches in  the future,  the cover  application thickness was increased  to
a total of 4 ft  (1.2  m)  or to 2 ft  (0.6 m)  above  grade.   The design  was
then able to proceed based  on  the following  design  dimensions:


     1.  Excavation depth = 8  ft (2.4 m)
     2.  Spacing = 8 ft  (2.4 m)
     3.  Width = 2 ft (0.6 m)
     4.  Length = 200 ft  (61 m)
     5.  Orientation = trenches parallel  to  each other  but  not
           necessarily parallel to contours
     6.  Sludge fill  depth = 6 ft (1.8 m)
     7.  Cover thickness = 4 ft (1.2 m)
                                    10-7

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          10.2.3.3  Site Development


Site development  was  in accordance  with  the plan  shown  in Figure  10-2.
Features of this plan included the following:


     1.  A 300 ft  (91 m)  wooded  buffer was maintained between the  sludge
         fill area and  residences.   A  200 ft  (61 m)  buffer  was maintained
         around the balance of the property.

     2.  Trenches  were   installed   along  the  downhill   (southeastern)
         property  line  to collect storm  water runoff.   A  sedimentation
         pond  was  constructed  to   receive  runoff  collected   by   these
         trenches

     3.  In accordance  with  State  regulations and  engineering judgement,
         one groundwater  monitoring  well  was located upgradient from  the
         fill area and  three  monitoring wells were  located  down-gradient
         from the fill  area.

     4.  The site was divided  into nine fill  areas  so that  the site could
         be  cleared   in phases.   In  this  way,  clearing  could proceed
         approximately  once  each  year  in  advance  of  sludge filling
         operations.

     5.  The  fill  area   located   nearest  to  the  site   entrance   was
         designated for wet  weather  operations.  The access road to  this
         area was paved with  asphalt.

     6.  The remaining  access  roads  were  covered with gravel.

     7.  After providing  area  for buffers,  access  roads,  facilities,  etc.
         approximately  156 acres  (63 ha)  remained  as usable fill area  out
         of the entire  375 acres  (152  ha)  on  the site.
          10.2.3.4  Calculations
Based  on  the design data  and  dimensions stated previously,  calculations
can  then  be  made  of  the  (1)  trench  utilization  rate,   (2)   sludge
application  rate,  (3)  land  utilization  rate,  and  (4)  site  life.
                                   10-8

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                  FIGURE 10-2
  SITE DEVELOPMENT  PLAN FOR EXAMPLE NO. 1
                                          PASTURE

                                          CHECK STATION
                                                         PASTURE
                          PASTURE
 LEGEND
— PROPERTY BOUNDARY
= ROAD
  DWELLING
  WOODS
       • ASPHALT PAVED ACCESS ROAD
	GRAVEL  ACCESS ROAD
       ) SEDIMENTATION POND
       MONITORING WELL
   ©  SLUDGE FILL AREA
                       10-9

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               .   -,   ,  ,  , .       .           sludge volume per day
               1.  Trench utilization rate •	a	;	r—-—=*—.—
                                        cross-sectional area of sludge
                                                in trench

                                     _   	sludge volume per day	
                                        Ttrench fill depth)x(trench widthT"

                                     _  (60.5 yd3/day)x(27 ft3/yd3)
                                              (6 ft) x (2 ft)

                                        181 ft/day  (55.2 m/day)
               2.  Sludge application rate = cross-sectional area of sludge in trench
                                            width of trench + spacing

                                      (6 ft)x(2 ft)   12 ft2 _ 12 ft3
                                     = (2 ft)+f8~Tt7   10 ft " TOTE?

                                     =     (12 ft3)(l yd3/27 ft3)
                                      (10 ft2)(l acre/43,560 ft2)

                                     = 1,936 yd3/acre (3,659 m3/ha)
                     .  . .,   . .     .     sludge volume per
               3.  Land utilization rate -  . ,  '	fTprat —


                                      80.5 yd3/day
                                      1,936 yd3/acre

                                   =  0.0416 acres/day (0.0168 ha/day)
               4.  Site life  =   usable fl11 area
                             land utilization rate

                                156 acres     =   3,750 days
                             0.0416 acres/day    365 days/year

                           =  10.3 years
             10.2.3.5  Equipment  and  Personnel


Table  6-4 in Chapter  6  (Operation)  should  be  consulted  as  a  reference.
As  shown,  for  a  narrow  trench  operation  receiving  between 50 and  100 wet
tons  per   day  (45  and  91  Mg  per  day)  the  following   equipment  might  be
selected:


      Description                              Quantity             Hours  per Week

       Track backhoe with  loader                 1                         49
      Track dozer                                   1                         !i

       Total                                          2                         64
                                            10-10

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The  use of  a  backhoe was  already  established  during  the  selection  of
design   dimensions.     Therefore,   the   above   suggested   scheme   was
implemented.  The duties  and  number  of  personnel  were  also  established at
this stage and  included:


     Description                        Quantity           Hours  per Week

     Backhoe operator                      1                      40
     Backhoe and dozer operator            1                      40_

     Total                                 2                      80
Operations  are  conducted  at  the site 8 hours  per  day and seven  days  per
week  to  coincide  with  sludge  deliveries  and  avoid  the  added  cost  and
odors  often encountered with sludge  storage  facilities.  The backhoe  is
operated seven  hours  per  day (plus one hour downtime per  day  for  routine
maintenance and cleanup)  and seven days per week.  The  dozer  is  operated
three  hours  per  day  (plus  one  hour  downtime  per   day   for   routine
maintenance and cleanup)  and five days per week.  One  full-time  operator
works  8  hours  per day Monday through Friday.   He is  responsible  for
operating  and  maintaining  the backhoe during  these hours.   The  other
operator  works  8  hours  per  day  Wednesday  through   Sunday;   he   is
responsible for (1) operating and  maintaining  the  backhoe  for  eight hours
each day on Saturday  and  Sunday,  (2) operating  and maintaining the dozer
for  four  hours each  day on Monday  through  Friday, and  (3)  performing
miscellaneous functions such as check  station  attendant, compiling  site
records, etc.
          10.2.3.6  Operational Procedures


Site preparation consisted of the following  procedures:


     1.  Initially, fill  area  no. 1 and  the inclement weather area  were
         cleared and grubbed.  Roads providing  access  to  these  areas  were
         paved with asphalt or gravel  (as shown  in  Figure  10-2).   Several
         trenches  were  excavated  in the  inclement weather  area  and  the
         spoil  stockpiled  alongside each  trench.   Runoff,  erosion,  and
         sedimentation  controls   as  well   as   monitoring   wells   were
         installed.

     2.  At least  one month  (but  never more than four months)  in  advance
         of  the  fill   operation,   each   new fill  area  is   cleared   and
         grubbed.  Usually these  operations occur once each year  and  are
         timed to  avoid cold temperatures  and  frozen ground conditions.
         The  work  is performed  by  equipment  and  personnel  brought  in
         specifically for  this  task.   Debris is  disposed  of on-site  by
         burial and/or  by producing wood  chips.
                                   10-11

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On-going operations consist of the  following:
     1.  Trenching  begins  in  the   corner  of  each  fill  area  furthest
         removed  from  the access road  and  proceeds generally  toward  the
         road as  it is completed.

     2.  Approximately  200 ft  (61   m)  of  trench  length  is prepared  in
         advance  of the  filling operation.    This  provides  contingency
         capacity for slightly  more  than  one  day's  sludge receipt.

     3.  Trenches are excavated to design dimensions  by the track backhoe
         as it straddles  the  excavation (see  Figure  10-3).

                              FIGURE 10-3

                OPERATIONAL PROCEDURES  FOR  EXAMPLE  NO.  1
                                                SLUDGE

                                                COVER SOIL
                                    10-12

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         Haul  vehicles back-up  to the  previously  excavated  trench  and
         dump  sludge  loads directly into the  trench.   Filling  proceeds to
         approximately 2 ft  (0.6 m) below the top  of the  trench.   Because
         of  its  low  solids  content,  sludge flows  evenly throughout  the
         trench  and accumulations  at  one location  are minimized.

         Within  one  hour   after  siudge-filling   has  occurred   in   one
         location,  the  track backhoe excavates  a  new trench adjacent  to
         the  filled trench.    Excavated  material  from  the  new trench  is
         applied  as cover over  the  adjacent sludge-filled  trench.    The
         cover   is  applied  carefully  from  a   low  height  at  first   to
         minimize  the  amount of  cover  sinking  into  sludge  deposits.
         Subsequently, cover is  applied less carefully.   Ultimately  the
         cover extends to 2  ft (0.6 m) above  grade.
Site completion consists of the following  procedures:


     1.  Approximately  one-month  after completion  of  each 1-acre  (0.405
         ha)  portion  of the  landfill,  the bulldozer  is  used to  regrade
         the area to a  smooth ground  surface.

     2.  Immediately thereafter the site  is hydroseeded  (assuming  weather
         conditions permit) and grasses soon take  root.
          10.2.3.7  Cost Estimates
Based  on  the  site design,  cost  estimates were  prepared  for capital  and
operating  costs  in Tables  10-1  and  10-2,  respectively.    As  shown,  the
total  capital  cost of the  site was  estimated  at  $1,186,421.  If  this  cost
is amortized  at  7% interest over  10  years (the  approximate  life of  the
site),  the annual  cost is  $168,923.   Considering  a  site  capacity  of
260,000 wet tons (236,000  Mg) of  sludge,  the capital  cost  is  $0.65  per
wet ton ($0.72 per Mg).


As  shown   in  Table  10-2,  the  annual  operating cost  was  estimated  at
$89,413.  Considering an annual receipt of 25,000 wet tons  (22,700 Mg)  of
sludge, the  unit  operating  cost   is  $3.58 per  wet  ton  ($3.95  per  Mg).
Combined capital  and operating costs  were estimated at  $4.23 per wet  ton
($4.67 per Mg).
                                   10-13

-------
                             TABLE  10-1

ESTIMATE  OF  TOTAL SITE  CAPITAL COSTS  FOR EXAMPLE  NO.  1
    I tern
                         _  Quantity

                            375 acres
                                         Unit Cost
    Land                    375 acres     $ 2.500/acre

    Site Preparation
      Clearing and Grubbing     45 acres     $  705/acre
      Sodded Runoff Ditch     4000 ft       $ 2.50/acre
      Pond                    1 ea       $15,000/ea
      Monitoring Wells          4 ea       $  300/ea
      Garage                1600 ft*      $   15/ft/
      Gravel Roads           1500 ft       $ 1.85/ft
      Asphalt Roads          1000 ft       $ 3.35/ft
      Miscellaneous             —           —
                           Total Cost _

                           $   937,500
                               31,725
                               10,000
                               15,000
                                1,200
                               24,000
                                2,775
                                3,350
                                5,000
Equipment
Backhoe
Dozer
Subtotal
Engineering @ 6%

1 ea $46,955
1 ea $41,760
	 	
— —

$
$
$
$

46,955
41,760
1,119,265
67,156
     Total
                                                         $ 1,186,241
     1 acre =  0.405 ha
     1 ft   =  0.305 m
                             TABLE  10-2

 ESTIMATE  OF ANNUAL  OPERATING  COSTS  FOR  EXAMPLE NO.  1
    Item
                             Quantity
                                            Unit Cost
                                                         Total  Cost
    Labor
     Backhoe Operator
     Backhoe/Dozer Operator

    Equipment Fuel, Maintenance
        and Parts
2,080 hrs
2,080 hrs
$ 8.00/hr
$ 8.00/hr
$16,640
$16,640
Backhoe
Dozer
Clearing and Grubbing
Gravel Roads
Officer Trailer Rental
Utilities
Laboratory Analyses
Supplies and Materials
Miscellaneous
2,555 hrs
780 hrs
10 acres
1,500 ft
1 ea
--
--
--
~~
$ 6.88/hr
$ 4.50/hr
$ 705/acre
$ 1.85/ft
$3,720/ea
--
--
—
~~
$17,578
$ 3,510
$ 7,050
$ 2,775
$ 3,720
$ 2,000
$ 2,500
$12,000
$ 5,000
    Total
                            $89,413
    1  acre =  0.405 ha
    1  ft   =  0.305 m
                                 10-14

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10.3  Design Example No. 2


     10.3.1  Statement of Problem
The  problem  was to  design  a sludge-only  landfill  at  the  location  of a
pre-selected  site.   As  stated previously, the  landfill  was to receive a
29%  solids  sludge from  a  proposed municipal wastewater treatment plant
serving a population equivalent of 50,000.  The  recommended design had to
be  (1)  in  compliance  with  pertinent  regulations,  (2) environmentally
safe,  and (3) cost-effective.
     10.3.2  Design Data


The following information is included as given design data and was useful
in executing the subsequent design.


          10.3.2.1  Treatment Plant Description
The  proposed municipal  wastewater treatment  plant was  to be  a modern
secondary treatment  facility.   Further  information on the facility is as
follows:
     1.  Service population equivalent = 50,000
     2.  Average flow = 5.0 Mgal/d (0.22 nwsec)
     3.  Industrial inflow = 0% of total inflow
     4.  Wastewater treatment processes:

         a.  bar screen separation
         b.  primary clarifier
         c.  secondary clarifier
         d.  sand filters
         e.  chlorine contact tanks
          10.3.2.2 Sludge Description


Sludge  was   to  be  generated  primarily  from  two  sources   (primary  and
secondary clarifiers).   The sludge was to  be  anaerobically digested  and
dewatered.  A more complete description is as follows:
                                  10-15

-------
     1.  SI udge sources:

         a.   primary clarifiers
         b.   secondary clarifiers

     2.  Sludge treatment:

         a.   gravity thickening
         b.   mixing
         c.   anaerobic digestion
         d.   dewatering via belt presses

     3.  Sludge characteristics (based on treatment plant design report)

         a.   solids content = 29%
         b.   quantity on a dry weight basis = 3.25 dry tons/day
                                           (2.95 Mg/day)

         c.   quantity on a wet weight basis = 11.2 wet tons/day
                                              (10.2 Mg/day)

         d.   density = 1,750 lbs/yd3 (1,039 kg/m3)

         e.   quantity on a wet volume basis

                     (11.2 tons/day)x(2,OQO Ibs/ton)
                            (1,700 lbs/yd3)

                  =  13.2 yd3/day (10.1  m3/day)
          10.3.2.3  Climate
Significant climatological factors having an impact on sludge landfill ing
are listed below:


     1.  Precipitation = 48 in./yr (122 cm/yr)
     2.  Evaporation = 30 in./yr (76 cm/yr)
     3.  Number of days minimum temperature 32°F (0°C) and below
                  =  125 days/yr
As shown, the climate is quite cold with freezing temperatures prevailing
much  of  the  year.     Precipitation   is   high  and  evaporation  exceeds
precipitation by 18 in./yr (46 cm/yr).
                                  10-16

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          10.3.2.4  General Site  Description
Site  data was  collected  from  existing  information  sources  as  well  as
field  investigations  performed  during  the  site  selection process.   This
data  is summarized  below:
     1.  Size  of  property =  12 acres

     2.  Property  line  frontage:

         a.  1,750 ft (533 m) along woodland
         b.  500 ft  (152 m)  along  crop  land
         c.  850  ft  (259 m)  along a  county  road  with  woodland  on  the
             other side

     3.  Slopes =  relatively flat  with  slopes  at  approximately 2%

     4.  Vegetation:

         a.  6.5 acres  (2.6 ha)  of woodland
         b.  5.5  acres   (2.2  ha)  of   open  space  sparsely  covered  with
             grasses

     5.  Surface  water  =  none   on site; drainage  on  site  via overland
         sheet flow  into roadside  ditch
A plan view of the site  is  presented  in Figure 10-4.  As  shown,  the  site
has  good  access  from  a two-lane  county  road  adjoining  the  property.
Approximately, one-half  of  the  site  is wooded; the balance  is  open  space
with  some  grasses.   Cropland  adjoins the  property  to the  east.   Other
adjoining  properties  are undeveloped  and wooded.
          10.3.2.5  Hydrogeology
During the  site  selection phase,  soil  maps for  the  area were  reviewed.
In addition,  logs  of soil borings  and  wells drilled  near  the  site  were
examined.   Historical  records  compiled on  nearby drinking  water  wells
were reviewed for groundwater levels and seasonal  fluctuations.
Subsequent to the site selection, four soil borings were  performed  at  the
site to verify subsurface conditions.  These borings  are  located  as  shown
in  Figure  10-4.    Subsurface  conditions  were  found  to   be   somewhat
consistent at all boring locations and can be  summarized  as  follows:
                                   10-17

-------
                                    FIGURE  10-4

                          SITE BASE MAP FOR  EXAMPLE NO. 2
                                                              100    200

                                                              SCALE IN FEET
300
        LEGEND

       - PROPERTY BOUNDARY
       = COUNTY ROAD
                                                               CROP LAND
 £&<£#; WOODS
200      CONTOURS
 S       BORING
                                    10-18

-------
     Depth                        Description

    0-10 ft  (0-3.0  m)          Coarse  sand  with  silty sand
    >10 ft  (>3.0  m)            Saturated  coarse  sand


As  shown  above,  the soil  was  primarily  a  coarse sand; however,  the  sand
had  some  layers  of silty  sand interspersed throughout.  Groundwater  was
at  a  10 ft  (3.0  m) depth.   Due to  the site's  location  on the  coastal
plain,  bedrock  is deep.   Samples of  the  coarse  sand were  collected  for
analysis and  the  following  determinations  were  made.


     1.  Texture  =  coarse
     2.  Permeability = 8  x 10~4  cm/sec
     3.  Permeability class =  moderately rapid
     4.  pH = 6.0
     5.  Cation exchange capacity (CEC)  =  8 meq/100  g
     10.3.3  Design


          10.3.3.1   Landfill ing  Method


Table  3-7  in Chapter 3  (Sludge  Characteristics and Landfill ing  Methods)
should  be consulted  as  a reference.  Since  the sludge is stabilized  and
has  a  solids content of 29%,  this  sludge can  be  disposed  in  any of  the
five  sludge-only methods shown.   Also,  none  of  these  five methods  are
disqualified on  the  basis  of  slopes,  since the  site  is relatively  flat
(2%  slopes).
Because the site was  relatively  small  and  a  longer  site  life  was  desired,
it was obvious early  in the design  process that  a high  sludge application
rate was required.  As shown  in  Table  3-8, the highest  sludge application
rates  are  attained  with  wide  trenches, area  fill  mounds,  and  diked
containments.  Diked  containment was ruled out because  the high  applica-
tion  rates sometimes  achieved  with  this method  are  only  possible  for
large diked containments  (with high dikes) receiving large quantities  of
sludge.  Wide  trenches  were  intially  selected based on the  cost-  effec-
tiveness of this  operation  versus area fill  mounds.  However,  subsurface
application of sludge at this site  was marginal.  Normally,  a  10 ft  (3.0
m) depth to groundwater would be sufficient to allow excavation and  still
provide  sufficient  buffer  soils.   However,  the soil's  coarse  texture,
moderately rapid permeability, low  pH, and low CEC  all  indicated  a  strong
potential  for  contaminant  movement  with  insufficient  attenuation.    Al-
though minimum soil bufgfers  of  2 to 5 ft  (0.6 to  1.5 m) are adequate  in
many cases, the State mandated an 8 ft (2.4 m) soil  buffer between  sludge
deposits and  groundwater.    Therefore, it became   apparent  that   surface
landfilling of sludge in area fill  mounds might  be the  only  alternative.
                                  10-19

-------
However, area  fill  mounds have disadvantages  in  high  precipitation areas
such as at this  site.   Therefore,  subsurface placement of sludge in lined
wide trenches  was  introduced  into  consideration.
          10.3.3.2   Design  Dimensions
Preliminary  designs were  performed  for each  of the  landfill ing methods
still under  consideration.   The purpose of these designs was to  provide a
basis  for the  site  life  and  cost  for  each  method.    Subsequently,  a
selection  of - the method  could  be made using  the  life and  cost  of each.
Using Tables 5-5 and 5-7  in Chapter  5 (Design), design  dimensions were
computed  for each method  as shown in Table 10-3.
                               TABLE 10-3

                  DESIGN  CONSIDERATIONS FOR EXAMPLE NO. 2
              Design Consideration
Wide Trench
                                                 Area Fill Mound
Width
Depth
Length
Spacing
Bulking performed
Bulking agent
Bulking ratio
Sludge depth per lift
No. of lifts
Cover applied
Location of equipment
Interim cover thickness
Final cover thickness
Imported soil required
50 ft
8 ft
200 ft
20 ft
no
--
—
4 ft
1
yes
sludqe-based
--
4 ft
no
„
--
--
--
yes
soil
1 soil: 1 sludge
6 ft
1
yes
sludge-based
--
3 ft
yes
               1 ft = 0.305 m
          10.3.3.3  Site Development
Site  development  was  planned in accordance with Figures 10-5 and  10-6 for
wide  trench  and   area  fill  mound  operations,  respectively.     Features
included  in  both  plans  are as follows:
          A buffer was maintained to all adjoining property.  Where  wooded
          areas  existed  along property  frontages, a  100 ft  (30 m)  wide
          strip  was maintained  in  its  natural  state.   Where grassy  open
          space  areas  existed along property  frontages, a  150  ft  (46  m)
          wide strip was undisturbed.

          A sodded diversion  ditch  was included  along  the  uphill side  of
          the site to  intercept  upland drainage.   Intercepted  runoff  was
          directed to  existing roadside ditches.
                                   10-20

-------
                      FIGURE  10-5
SITE  DEVELOPMENT  PLAN FOR EXAMPLE NO.  2 WIDE  TRENCH
                                                  100     200
                                                  1       F"
                                                  SCALE IN FEET
                                                               300
                                                     CROP LAND
LEGEND
-PROPERTY BOUNDARY
 COUNTY ROAD
'WOODS
 ASPHALT PAVEMENT
                        MOUND AREA
                       • DIVERSION DITCH
                        COLLECTION DITCH
                        SEDIMENTATION POND
                       10-21

-------
                                  FIGURE 10-6
          SITE DEVELOPMENT PLAN FOR  EXAMPLE NO.  2 AREA  FILL MOUND
                                                              100     ZOO
                                                                     H—
                                                               SCALE IN FEET
                                       300
                                                                   CROP LAND
                                                                  CROP LAND
         LEGEND
---- PROPERTY BOUNDARY
...... COUNTY ROAD
        WOODS
---- GRAVEL  ROAD
TRENCH
DIVERSION DITCH
COLLECTION  DITCH
SEDIMENTATION POND
                                     10-22

-------
     3.  A  sodded  collection ditch was  included  along  the downhill  side
         of  the  site to intercept on-site  drainage.   Intercepted  runoff
         was directed to a  new  sedimentation  pond.


Features  specific  to  the  wide  trench  operation  shown  in  Figure  10-4
included the following:
     1.  Trenches  were  laid  out  in accordance with design dimensions  and
         made optimal use  of  available  land.

     2.  Gravel  roads were constructed  as  shown to  provide access  from
         the site  entrance to  individual trenches.

     3.  Sheets of 20 mil  (0.05 cm) Hypalon were  selected  for  application
         to the floor and  sidewalls (2:1 slope)  of  all trenches.
Features specific  to  the area fill mound  operation  shown in Figure  10-5
included the following:
     1.  An  asphalt-paved   dumping/mixing   pad   and  access  road  were
         specified.

     2.  A  soil  stockpile area was located  near  the dumping/mixing pad.
         Soil for this stockpile was  imported once  each year  from  another
         location incurring  a 3-mile  haul.
     3.  Most  of  the  remaining  site  area  was  designated  for  sludge
         mounding  operations.
         10.3.3.4  Calculations
Based on  the  design data and  dimensions  stated previously, calculations
were   performed   for   each   of  the   proposed   landfill ing   methods.
Determinations made on the wide trench application  include:


     1.  Trench capacity = 1,481 yd3/trench (1,132 m3/trench)
     2.  Number of trenches =  12
     3.  Site capacity = 17,772 yd3 (13,588 m3)
     4.  Sludge volume received = 13.2 yd3/day  (10.1 m3/day)
     5.  Site life = 3.7 years
                                   10-23

-------
Determinations made on the area fill mound application include:


     1.  Sludge application rate = 9,680 yd3/acre (18,295 m3/ha)
     2.  Size of mounding area = 3 acres (1.22 ha)
     3.  Site capacity = 29,040 yd3 (22,204 m3)
     4.  Sludge volume received = 13.2 yd3/day (10.1 nr/day)
     5.  Site life = 6.0 years
         10.3.3.5  Equipment and Personnel


Using Table 6-4  in Chapter 6  (Operation) as a  reference,  the following
equipment  and  personnel   were  selected  for  use   at   the  wide  trench
operation:


     Description                Quantity            Hours per Week

     Track dozer                    1                      10
     Track dozer operator           1                      15
The following  equipment  and  personnel  were selected  for  use at the area
fill mound operation:

     Description                Quantity            Hours  per Week

     Track loader                   1                       15
     Track loader operator          1                       20
         10.3.3.6  Cost Estimates
Cost  estimates  were  computed  for  each  of  the   proposed   landfill ing
methods.   These  estimates  have been  included  as  Tables  10-4 through
'10-7.  As  shown,  the  annual  operating cost of the wide trench  operations
was  calculated at  $30,195.    The  total   capital  cost was  calculated  at
$95,552.   This amount  was  amortized  at  7%  interest  over 4  years  (the
approximate  life  of the  wide  trench operation).   The amortized capital
cost derived was $28,209.


The  annual operating cost  of the area fill  mound  operation  was  calculated
at  $44,624.    The  total  capital  cost was calculated  at  $107,325.    This
amount  was  amortized  over  6  years  (the  life  of  the   area  fill   mound
operation).  The  amortized capital  cost derived was  $22,517.
                                   10-24

-------
                       TABLE  10-4-

 ESTIMATE  OF  TOTAL  SITE  CAPITAL  COSTS FOR EXAMPLE NO. 2
                       WIDE  TRENCH
Item
Land
Site Preparation
Clearing and Grubbing
Sodded Division Ditch
Sodded Collection Ditch
Pond
Monitoring Wells
Gravel Roads
Miscellaneous
Equipment
Track Dozer
Subtotal
Engineering @ 6%
Total
1 acre = 0.405 ha
1 ft = 0.305 m
Quantity
12

6
1,750
850
1
3
950


1





acres

acres
ft
acres
ea
ea
ft
--

ea
„
--
--


Unit Cost
$ 2

$
$
$
$ 3
$
$


$41





,500/acre

705/acre
2.50/ft
2.50/ft
,000/ea
300/ea
1.85/ft
--

,760/ea
__
--
--


Total Cost
$30.000

$ 4.230
$ 4,375
$ 2,125
$ 3,000
$ 900
$ 1,757
$ 2,000

$41,760
$90,147
$ 5,405
$95,552


                      TABLE 10-5

ESTIMATE OF ANNUAL SITE OPERATING COSTS FOR EXAMPLE  NO.  2
                       WIDE TRENCH
Item
Labor
Dozer Operator
Equipment Fuel, Maintenance
and Parts
Track Dozer
Hypalon Liner (installed)
Laboratory Analysis
Other Supplies and Materials
Mi seel laneous
Total
Quantity
780 hrs
520 hrs
2,700 ft2
--
Unit Cost
$8.00/hr
$4.50/hr
$0.45/ft2
--
Total Cost
$ 6,240
$ 2,340
$ 1,215
$ 2,500
$ 5,000
$ 2,000
$30,195
1 ft2 = 0.093 m?
                        10-25

-------
                           TABLE  10-6

 ESTIMATE OF  TOTAL  SITE  CAPITAL  COSTS FOR EXAMPLE  NO.  2
                          AREA FILL MOUND
Item
Land
Site Preparation
Clearing and Grubbing
Sodded Division Ditch
Sodded Collection Ditch
Pond
Monitoring Wells
Asphalt Paving
Miscellaneous
Equipment
Track Loader
Subtotal
Engineering 1? 6?
Total
Quantity
12
6
1,750
850
1
3
4,200
1
-
-
acres
acres
ft
ft
ea
ea
ft2
ea
-
-
Unit Cost
$ 2
$
$
$
$ 3
$
$ 0
$52


,500/acre
705/acre
2.50/ft
2.50/ft
,000/ea
300 /ea
.45/ft2
,730/ea
--
-
Total
$ 30,
$ 4,
$ 4,
$ 2,
$ 3,
$
$ 1,
$ 2,
$ 52,
$101,
$ 6,
$107,
Cost
000
230
375
125
000
900
890
000
730
250
075
325
1 acre = 0.405 ha
1 ft = 0.305 m
1 ft2 = 0.093 m2
                             TABLE 10-7

ESTIMATE OF  ANNUAL  SITE OPERATING  COSTS  FOR  EXAMPLE  NO.  2
                          AREA FILL  MOUND
    Item
                            Quantity
           Unit Cost
                                                      Total Cost
    Labor
     Loader Operators

    Equipment Fuel, Maintenance,
       and Parts
     Track Loader

    Laboratory Analysis
    Supplies and Materials
    Miscellaneous

    Total
1,040 hrs
  780 hrs
$ 8.00/hr
           $ 8.98/hr
$ 8,320
             $ 7,004

             $ 2,500
             $ 5,000
             $ 2,000


             $24,824
                            10-26

-------
Unit  costs  for  each  operation  were  compiled  and  are  summarized  below:
Wide trench

Area fill mound
  Amortized
 Capital Cost

$6.90/wet ton
($7.61/Mg)
$5.51/wet ton
($6.07/Mg)
 Operating
   Cost

$7.39/wet ton
 ($8.15/Mg)
$9.26/wet ton
 ($10.21/Mg)
   Total
    Cost

$14.29/wet ton
  ($15.76/Mg)
$14.77/wet ton
  ($16.28/Mg)
         10.3.3.7  Conclusion
An  area fill  mound  operation  was  subsequently selected  and  utilized.
Although the mound  operation  actually  cost more  than  the  wide  trench,  the
cost  difference was  not that  substantial   and  the  mounding   operations
longer  life made it the  clear-cut  choice.
10.4  Design Example No. 3
     10.4.1  Statement of  Problem
The  problem was  to  design  a  sludge-only  landfill   on  the  site  of  a
wastewater treatment  plant  serving  a  population  equivalent  of  5,000.   The
plant had been  disposing  of their 34% solids sludge at a refuse  landfill
8 miles  (13  km) distant.   However,  landfill  operators were now  charging
$8.00  per  wet  ton  ($8.82  per  Mg)  for  the  sludge;  treatment   plant
operators sought  the cost-savings that might  be realized   by  landfill ing
the  sludge  themselves.    The  recommended  design  had  to   be   (1)   in
compliance with  pertinent  regulations,  (2)  environmentally safe, and  (3)
cost-effective.
     10.4.2  Design Data
The following information  is included as given design  data  and  was  useful
in executing the subsequent design.
         10.4.2.1  Treatment Plant Description
Ther existing wastewater treatment facility was a package plant.  Further
information on the facility is as follows:
                                   10-27

-------
     1.  Service population equivalent = 5,000
     2.  Average flow = 0.5 Mgal/d (0.022 rrvVsec)
     3.  Industrial inflow = 0% of total inflow
     4.  Wastewater treatment processes:

         a.  bar screen separation
         b.  primary clarifier
         c.  aeration tanks
         d.  secondary clarifier


         10.4.2.2  Sludge Description


Sludge  from the  secondary  clarifier was  recirculated  to  the  primary
clarifier.   The sludge was  stabilized  and dewatered.   A more  complete
description is  as follows:
     1.  Sludge sources - sludge from secondary clarifier recirculated to
         primary clarifier and withdrawn as mixture with primary sludge

     2.  Sludge treatment:

         a.  aerobic digestion
         b.  dewatering via sand drying beds

     3.  Sludge characteristics (based on testing, review of records, and
         calculations)

         a.  solids content = 34%
         b.  quantity on a dry weight basis = 0.33 dry tons/day
                                              (0.30 Mg/day)

         c.  quantity on a wet weight basis = 0.96 wet tons/day
                                              (0.87 Mg/day)

         d.  density = 1,850 lbs/yd3 (1,098 kg/m3)
         e.  quantity on a wet volume basis = 1.03 yd^/day
                                              (0.79 m3/day)
         10.4.2.3  Climate
Significant climatological factors having  an  impact on sludge landfill ing
are  listed below:
                                   10-28

-------
     1.  Precipitation = 32 in./yr (81.3 cm/yr)
     2.  Evaporation = 34 in./yr  (86.4 cm/yr)
     3.  Number of days minimum temperature 32°F (0°C) and below
                  = 40 days/yr
As shown the  climate  is marked by mild  temperatures.   Precipitation and
moderate and  is exceeded slightly by evaporation.
         10.4.2.4  General Site Description


The  area  to be used  for sludge landfill ing  occupied  a 3-acre  (1.2 ha)
portion of the 8-acre  (3.2 ha)  treatment  plant  property.  It was located
immediately  adjacent  to  the   plant's  sand  drying  beds.   Other  data
concerning this 3-acre tract is summarized below:


     1.  Adjoining properties and facilities:

         a.  700 ft (210 m) abuts woodland which is privately owned
         b.  700 ft (210 m) abuts treatment plant facilities

     2.  Slopes = evenly sloped at about 6%

     3.   Vegetation  = all  3 acres  (1.2 ha)   had  been  previously cleared
          and  are  covered with  grasses

     4.   Surface  water =  none  of  the  3-acre  (1.2  ha)  tract.   A stream
          which receives  effluent  from the  treatment   is  located 500  ft
          (150 m)  away.
         10.4.2.5  Hydrogeology


Site  hydrogeological   data   was  collected   largely  from  information
contained  in  the treatment  plant  report and  drawings.   Some additional
information  on  soils,  bedrock,  and  groundwater was  obtained  from  the
sources listed in Table 5-3 of Chapter 5  (Design).


Subsurface conditions are summarized as  follows:


     Depth                            Description

     0-10 ft (0.3.0 m)             Silty clay with some clay lenses
                                     interspersed throughout
    10-12 ft (3.0-3.7 m)           Saturated silty clay
    12-15 ft (3.7-4.6 m)           Clay
    15-26 ft (4.6-7.9 m)           Saturated silty clay
    >26 ft (7.9 m)                 Bedrock

                                   10-29

-------
As shown, the  upper  10  ft (3.0 m) of soil was  a  dry silty clay; ground-
water was encountered  at a 10 ft  (3.0  m) depth.   A 3 ft  (0.9 m)   thick
tight clay seam  protects  the  groundwater located  below it.  Using Tables
4-1 and 4-2 and  Figure  4-4  and 4-5 from  Chapter  4  (Site  Selection), the
following determinations  were made:
     1.  Texture = fine
     2.  Permeability = approximately 10"^ cm/sec
     3.  Permeability class =  very slow
     4.  Cation exchange capacity (CEC) = over 20 meq/100 g
     10.4.3  Design


         10.4.3.1  Landfill ing Method
Table 3-7 should be consulted  as a  reference.  This  site was  conducive  to
subsurface  placement  of  sludge since  (1)  groundwater  and  bedrock are
relatively  deep  (at 10  and 26 ft (3.0 and  7.9  m),  respectively) and (2)
the  soils are  tight  enough to afford sufficient environmental  protection
even when  sludge is placed  relatively  close to the groundwater.   Since
area  fills  are  generally more  manpower  and   equipment-intensive  then
trenches,  trenches should be  selected   in almost  all   instances   where
hydrogeologic  conditions   allow.   In addition,  wide  trenches  should  be
selected over  narrow trenches  for  sludge  with  a solids content  of  34%  as
shown  in  Table  3-8.     Cover application  should  be  via  sludge-based
equipment.   All  of these  considerations  were established and utilized  in
the  preliminary  design.
         10.4.3.2  Design Dimensions


Using Table 5-5, the .following  design dimensions were  established:
     1.  Width =  20 ft  (6.1 m)
     2.  Depth =  8 ft  (2.4 m)
     3.  Length = 100 ft  (30 m)
     4.  Spacing  = 30 ft  (9.1 m)
     5.  Sludge fill depth = 5 ft  (1.5  m)
     6.  Cover thickness  = 4 ft  (1.2 m)
Test  trenches  were then constructed on  the  site and operated  under  pro-
posed  conditions  to  ensure  their  effectiveness  and  practicality  in  a
full-scale  operation.   The test  was  successful  and the design  proceeded
based  on  the above dimensions.
                                  10-30

-------
         10.4.3.3  Calculations
Based on  the  design data and  dimensions  stated previously, calculations
were performed  for  each  of  the proposed landfill ing methods.  Determina-
tions made on the operation included:


     1.  Trench capacity = 375 yd3  (287 m3)
     2.  Number of trenches =20
     3.  Site capacity = 7,500 ydj  (5,734 nr)
     4.  Sludge volume received = 1.03 yd3/day  (0.79 m3/day)
     5.  Site life = 20 years
         10.4.3.4  Operational Procedures


Site preparation, on-going operations, and site completion consist of the
following procedures:
     1.  Twice each year  a  contractor  is  employed to excavate sufficient
         trench capacity  for  a 6 month sludge  quantity.   The contractor
         uses a single  front-end loader to  excavate each 20  ft  (6.1 m)
         wide trench  to  a  depth of 8  ft  (2.4 m).   Excavated  soil  is
         stockpiled above and along both sides  of the trench.

     2.  Immediately  after  the trench  is  excavated, 6  months accumula-
         tion of sludge is  removed  from sand drying beds with pitchforks
         and loaded on a dump truck owned by the treatment plant.

     3.  The sludge  is  hauled the short distance  to the trenching area.
         At that  location,  dump trucks back into the trenches  from the
         open end of the trench  and deposit  the sludge  in 3  to 4 ft  (0.9
         to 1.2 m) high piles.

     4.  A bulldozer  enters the  trench  intermittently to push the sludge
         into a 5 ft  (1.5 m) high accumulation.

     5.  After each  trench  is  filled  to  completion,  the  bulldozer is
         employed to spread cover over the 20 ft (6.1 m)  wide trench from
         the soil  stockpiles located on either  side.  The cover is spread
         in a  4  ft  (1.2 m)  thick application to  1  ft  (0.3 m)  above
         grade.

     6.  The completed  trench is  then  seeded  to  promote the  growth of
         grasses.
                                   10-31

-------
     7.  Usually settlement of the  trenches  is  not too severe due to  the
         high  solids content  of  the  sludge  and  the  cover thickness.
         However, once  each  year the bulldozer  employed for  landfilling
         operations  is   used   to  regrade completed   trenches  from   the
         previous year.   These trenches are then reseeded.
         10.4.3.5  Cost Estimates


The cost estimate prepared for this operation  is  presented  in  Table  10-8.
As shown, the total cost  was  computed  at $1,109 per year.   Considering  a
sludge quantity of 379 wet tons  per year (344 Mg per year), this  equates
to $2.93 per wet ton  ($3.23 per  Mg).   This represents a savings of  $5.07
per wet ton ($5.59 per Mg) when  compared to the fee being  charged by  the
local  landfill.   Accordingly,  plant  operators  initiated  the  previously
described operation.
                               TABLE  10-8

             ESTIMATE OF  TOTAL ANNUAL COST  FOR  EXAMPLE  NO.  3
Item
Mob Ui zation
Loader
Dozer
Trench Excavation
Covering
Regrading
Seeding
Total
Quantity

2 ea
2 ea
600 yd3
230 yd2
230 yd2
450 yd2

Unit Cost

$50/ea
$50/ea
$0.90/yd3
$0.60 /yd2
$0.30/yd2
$0.36/yd2

Total

$
$
$
$
$
$
$ 1,
Cost

100
100
540
138
69
162
109
               1 yd3 = 0.765 m3
               1 yd2 = 0.836 m2

 It  should  be noted  that  costs as low as $2.93 per  wet  ton  ($3.23 per Mg)
 cannot  be achieved  by most  treatment  plants of this  size.   One  of the
 reasons  the  cost  was low  was  that  this  plant  was able  to  landfill  6
 months  sludge  in  one or  two  days.    Under these circumstances,  this
 facility  was  able  to achieve economies-of-scale  usually  found  only  at
 very large sludge landfills.
                                    10-32

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                               CHAPTER 11

                              CASE STUDIES
11.1   Introduction
Five case studies are presented  in this chapter to  illustrate  the  variety
of  existing  landfill ing methods.   Of the  five,  one is  a  narrow trench
operation,  two  are wide  trench operations,  one  is  an  area  fill  layer
operation,  and  one is  a codisposal  operation.   The  five  case  studies
included in the manual  were  selected  from a total of 22  sludge  landfills
that were studied in detail.
11.2  Case Study Summaries


The twenty-two sludge  landfills  were studied to identify site  selection,
design, and operation  procedures that are relevant to  sludge  landfill ing.
In  addition,   public   participation,  monitoring,  costs, equipment,  and
personnel for each site were examined.  The  data was accumulated  via  site
visits and interviews  with site  operators, planners, and designers.


A  summary  of the  above-described  information  has  been compiled on the
next four pages.  Figure  11-1  shows  the  locations  of the sites and Table
11-1 summarizes  the  treatment  processes and  resulting sludge  quantities
for each site.   Design and  operational  features are  presented  in Table
11-2.    Hauling  and  site  costs  are  detailed  in Table  11-3.   The  data
contained  in  these  compilations  was  useful  in   observing   trends  and
establishing design criteria.   As a  result, this data  formed the basis
for much of  the information  presented  in this  manual.   The reader may
find it  equally useful  to  peruse this  data  in determining  trends and
criteria relevant to a specific  operation.
                                   11-1

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                               TABLE 11-3



                          HAULING  AND SITE  COSTS
Hauling Costs ($)
Site
No.
1
2
3
4
5
6
7
8
9
10A
10B
11
12
13
14
15
16
17
18
19
20
21
22
Pec
yd3

—
__
__
—
—
__
1.57
15.92
4.00
1.42
—
—
4.93
—
__
—
—
__
0.17
—
—

Per
wet ton

—
__
__
—
—
__
1.80
17.90
4.40
1.64
—
—
5.50
—
—
--
—
__
0.22
—
--

Per
dry ton

—
—
__
—
—
—
14.40
83.25
20.00
54.67
—
_.
25.00
—
_.
—
—
__
1.57
—
—

Pec
yd3
0.50
0.91*
2.35
3.03
4.45
2.12
4.16
1.05
28.14
1.06
0.57
1.96*
—
5.83
4.91
_-
1.92
2.37*
1.64
1.03
1.03
__
2.93
Site Costs ($)
Per
wet ton
0.55
1.01*
2.59
3.41
4.98
2.50
4.46
1.21
31.64
1.17
0.66
2.14*
—
6.50
5.35
_-
2.19
2.69*
1.84
1.33
1.17
_-
3.31
Per
dry ton
1.96
4.59
9.25
17.05
22.64
62.50
12.05
10.08
143.82
5.32
22.00
7.13*
__
25.00
16.71
__
10.43
18.17*
9.20
9.50
6.15
__
10.61
* Operating costs only.  Does not  include site capital costs.
                                    11-5

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11.3  Montgomery County, Maryland
     11.3.1  Background and History
Site 216 was  located  in Montgomery County,  Maryland  about 25 mi  (40  km)
east of Washington, DC.  It received about  half  of the total sludge from
the  Blue  Plains  Treatment  Plant  which  serves Washington  DC. The  plant
uses a  step  aeration  activated  sludge  process to  treat  a  flow of  309
Mgal/d  (13.5  nr/s) with less  than  a  10%  contribution  from  industrial
sources (Figure  11-2).   From  this flow the  site  received about  106,000
wet tons (96,152  Mg)  of primary and secondary  sludge  per  year containing
about 20 to 23%   solids.   The sludge is  dewatered using gravity  thick-
ening and  vacuum filtration.   Lime  is  used  in the treatment process  to
control   pH,  stabilize  biological  activity,  and  provide  odor  control.
This contributed  another 7,300  dry tons  (6,621  Mg)  of  waste  per year.   An
additional   2,700  dry  tons  (2,450  Mg)  of  ferric  chloride   and  polymers
from the treatment process  was produced  each year.   The  site opened  in
February of  1976  and  closed  in  February 1978.    Narrow trenches  were
selected as the landfill ing method.
                              FIGURE  11-2

                BLUE PLAINS TREATMENT PLANT  FLOW  DIAGRAM
          INFLUENT
PRIMARY
kBASINS/J

f
AERATION
BASINS


FINAL
CLARIFIERS
                                                       EFFLUENT
                                                       15/25%
                                                        FILTER
                                                        CAKE
     11.3.2  Site Description
The  site  occupied  719  acres  (290  ha)  of  gently sloping  terrain.   The
highest elevations, 540 ft  (165  m)  mean sea level (MSL), were  located in
the  eastern  portion  of  the site and the lowest  elevations,  approximately
                                   11-6

-------
 400  ft  (122  m)  MSL  were  found  in  the western  portion.    Site 216  was
 underlain  by the  Wissahickon  Schist with  a  saprolite thickness  varying
 between  20  to 50 or more ft (6 to  15  m)  throughout the property.   Other
 relevant site characteristics  are detailed  below.
t  Topography

•  Soil type
   Depth to groundwater
   Groundwater use
   Freezing days
   Precipitation
   Evaporation
                                          gently sloping;  drains to
                                          Anacostia River
                                          silty loam;  moderately
                                          permeable
                                          6 to  36 ft (1.8  to 11  m)
                                          aquifer provides potable  water
                                          90 days/yr
                                          40 in./yr (102 cm/yr)
                                          47 in./yr (119 cm/yr)
           11.3.3   Site  Selection
 In  general,  the  site selection process established  physiographic,  econo-
 mic  and  other technical  parameters inherent in  a  desirable  disposal  site
 and  then  identified  suitable  areas.   The  initial  parameters  included:
•  Soils
•  Topography
•  Geology
•  Surface and
                     groundwater  conditions
The  first  step  in the selection  process  was  to delineate  suitable  areas
of the county based  on these  considerations.  Acetate  overlays  indicating
unsuitable  areas  were made for each of these  criteria and placed over  a
county map.  The  areas remaining  were  characterized  as "High  Priority".


The  County  used  this process to  find  areas  that were  generally  suitable
for  sludge disposal.   Some  specific  sites  within the  "High Priority"
areas had  poor  drainage,  inadequate  soil cover,  or other disqualifying
characteristics;  conversely,  there were  sites  outside the area that  met
the  geomorphic requirements of a  sludge disposal site.
Using  newspaper  advertisements,  real  estate agents,  past  site  inven-
tories, and site  visits the county identified 20 potential  sites  in  these
areas.  These  sites  were  in turn screened,  and  those that required  ela-
borate  modification  such  as  tree cutting  or extensive  excavation  were
eliminated.
A total of 8 potential sites emerged from this process and were subjected
to an in-depth screening based on the following criteria:
                                    11-7

-------
       t   Site  physiography

           -  expected life of the
           -  soils and geology
           -  topography and slope
           -  screening and buffer
           -  groundwater
           -  surface  water
         site
       •  Other  technical  considerations

          -  zoning and land use
          -  site  availability
          -  haul  route

       •  Site costs

          -  haul  distance
          -  site  acquisition costs
          -  site  preparation costs

The  current  site (Site 216) was judged to  be the best,  based  on  the  above
criteria and on  state and county  policies  outlined  in Table  11-4.   Figure
11-3  is  a  map of the  site selected.   It was purchased rather  than  leased,
and   realtors  were  notified  of  the   purchase.    In  addition,   several  ads
were  placed  in  local  newspapers   so  that  the  public  was  aware   of  the
action.

                                      TABLE  11-4
             REGULATORY REQUIREMENTS
                          AT  MONTGOMERY
                              Jurisdiction
                                 Code
             RELATIVE  TO  SITE  SELECTION
             COUNTY,  MARYLAND

            	Description of Constraint/Directive
           1.  Geoloay
           2.  Soils
           3.  Topography
           4.  Groundwater
           5.  Surface Water
SCS, MSH



SCS, MSH



MSH



MES


SCS, MSH



WRA
           6.  Buffer and         MC
               Screening
Restrict site selection where shallow
soil cover over bed rock,  and where
sand and gravel is present.

Set site selection criteria according
to  permeability, infiltration rate,
runoff  and susceptability  to flooding.

Site selection - site m Patuxent
watershed, classified as "secondary" or
low priority.

12 percent maximum slope (operation
limitation).

Buffer  of 3 ft between the bottom of
the trenches and the highest expected
groundwater table level.

Eliminate sites that drain into
Tridelphia and Rocky Gorge Water supply
reservoirs.  Buffer of 100 ft between
streams and trenching operations.

500 ft  buffer between trenching
operations and residences  or schools.
           MC =  Montgomery County Department of Environmental Protection
           MSH = Maryland State Health
           WRA = Maryland Water Resources Administration
           SCS = Soil Conservation Service
                                            11-8

-------
There  were  approximately 719  acres  (290 ha)  and  the land was  privately
owned.  About 41%  of the area was wooded; the  remaining  area  was  largely
agricultural.
     11.3.4  Design


The county employed  a  narrow  trench  that  was  2  ft  (0.6 m)  wide, 3 ft  (0.9
m)  deep and  varied  lengths.   The intertrench  distance  was  2 ft  (0.6  m)
and cover was mounded  3 ft  (0.9  m)  over the  sludge deposits.


The design and  operation  insured that the sludge wsa  exposed  for a mini-
mum time and thus  reduced  odors,  ponding  from rainfall,  and other  un-
desirable events.  Usable areas  were defined  and mapped  during the design
process  based on soil  thickness  and  depth to  groundwater.
     11.3.5  Public Participation


          11.3.5.1  Public  Interaction  During  the  Selection  Process


Recognizing  the  sensitivity  of  residents  to  sludge  disposal   sites,
Montgomery County  attempted to use education and  communication  to  defuse
this volatile  issue.
After  site  selection was  performed  by  a  consultant, the  county held  a
public  hearing  in Rockville, Maryland.   Maryland Environmental  Services
(MES)  made  a formal  presentation on  the proposed  site, its  operation,
and  impact.   They  encountered  opposition  from well-organized  community
groups  based on  the  fears that  the  site  would  generate  and  release
pathogens into local air  and water;  that the site would  be the  source  of
objectionable odors,  that deliveries would  cause  increases  in  noise  and
traffic; and  that the  site would lower  property  values.   The site  had
previously been considered  for  a  sanitary landfill and the groups  invol-
ved  in  protesting the selection were  largely  an extension of  opposition
organizations that had formed previously.


The  county   responded  by  organizing field  trips  to the  nearby  Prince
Georges County trenching  site.  Transportation  was  provided by  the  county
to  all  interested  residents.    Despite  these  efforts  the   neighborhood
groups  filed  two suits  against the  operating  agency.   Ultimately,  the
operation was commenced on  schedule  in  February 1976.
                                   11-9

-------
          11.3.5.2  On-going Public Relations


After commencing  operations,  a mechanism to  provide  for continuous  com-
munication  between  MES  and the  neighborhood  group  representatives  was
established.  Also, Montgomery County designated  one  person to  personally
handle any complaints from  neighbors and other  county  residents.


     11.3.6  Operation


The site  operated  from 7  a.m.  to 6 p.m.  with the last  half hour  being
used for cleanup only.  Following  is a discussion  of  the  site preparation
and sludge handling  procedures  during  the  transfer and on-site phases  of
the operation.


          11.3.6.1  Site Preparation
The site  did  not require extensive  excavation,  but control of  drainage,
as  in  most cases,  was critical.    Grass  diversion  ditches,  berms,  and
swales directed  runoff into sediment  control  ponds.   All  the  ponds  had
risers and were  constructed  to contain a flood equivalent  to  the  largest
5-yr  flood anticipated;  two  of  the  five  ponds  had  bentonite  liners.
Provisions were  made  to  spray  irrigate  excess   pond  water as  necessary
over completed fill areas.


Based on  soil  cover  and  depth  to groundwater, usable  areas were defined.
Of the total  719 acres (290 ha),  142  acres  (57.5 ha) were estabished  as
usable  and  these  were   scattered  throughout  the  site.    Two  factors
contributed  to  this  relatively  low ratio  of  usable  to  total acreage.
First, narrow trench  operations  are land intensive  and  second, much  of
the land  was  eliminated  because  the soil  cover  was  not  thick  enough  to
provide the 3 ft (0.9 m)  buffer  between  trench  bottoms and  groundwater
required  by the  State. Access  roads  to the usable  sites were  built  to  be
temporary, with  a  design  life  of about one  year.   As areas were  filled,
the roads were  removed  and  the material  was  reused  to  make new  access
roads.   Figure 11-3 shows the  network of roads  used  during  the life  of
the site.
The  entire  site was surrounded  with a 5  ft  (1.5 m)  farm fence and  the
holding  ponds  were  enclosed within a 6 ft  (2 m)  fence equipped with  a  1
ft  (0.3  m)  barbed extension.   There were two wash  pads  for the trucks.
The  washing  area was  contained  and  runoff  was  directed  to the holding
pond.   In addition, the  facility  was  equipped  with  3 trailers housing
administrative  offices, showers  and restrooms.
                                   11-10

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     FIGURE  11-3


  SITE LAYOUT  PLAN
MONTGOMERY COUNTY,  MD
                                         8
                                         •
                      •  MONITORING  WELL

                     !   USABLE AREA
         11-11

-------
The design  incorporated  an  extensive odor control system that,  in  retro-
spect, did  not function  adequately.   Four  in.  (10  cm)  perforated  PVC  pipe
was installed  along  the perimeter of the  site and  in the  original  plan
would have  sprayed masking  agents when  necessary.  In  practice,  site  per-
sonnel found  spray trucks equipped  with  "Chemscreen"  and "Arrest" which
sprayed masking agents directly  on the  sludge  to  be  more  effective.
It is projected that the  final  land use will be agricultural.  The  site,
which closed  in February  1978,  will remain abandoned and monitored  for  5
to 7 yrs.
          11.3.6.2  Sludge Loading  and Transport


The sludge was  loaded  on  hopper trucks  from a railroad car  equipped  with
three augers.   The  trucks had a capacity of 72,500  Ib (32,915 kg) or  31
yd^  (24  nr)  per  truck  and  included  three  compartments.    The   haul
distance was 37 mi  (60 km)  and  the  total  average number of  trips  per day
was 30.  Prior  to reaching the disposal site,  the trucks radioed  ahead  to
alert  crews  at the disposal area  that  was  currently being  used.    The
operation maintained two  disposal areas at  all times  and used  them simul-
taneously.
          11.3.6.3  Operational Procedures
A  hose  was  attached  to the  top of  a hopper  truck  and  the  sludge  was
forced  via  compressed  air applied  at  a  pressure  of  20  Ibs/in.Z  (1.4
kg/cm2) through  a hose from  the  bottom of the truck  into the hopper  of
a high-powered concrete pump.  This  pump then  forced the sludge through a
200 ft  (60 m)  long, 5  in.  (2.7  cm)  diameter flexible hose.  The  hose,  in
turn, was  guided  over the 2  ft  (0.6 m)   wide trench  with  a front-end
loader.


Simultaneously,  the  adjoining trench  was  excavated by  a trencher.   The
machine applied  soil  from the  new trench  over the trench receiving  the
sludge,    thus  minimizing the time  that  the  sludge  was exposed to  the
air (see Figure  11-4).  The receiving  trench  was  mounded to  approximately
3  ft  (0.9  m).    The  last trench  was  covered  with  soil  from   another
source.  Figure  11-5 through  11-7  illustrate  the  operation.


The access  roads  were  placed in  such a  way  as to  maximize  the  usable
areas.   In  general,  the areas  were  surrounded with two roads joined  at
the end and  separated  by about 215 ft  (66  m)  of usable  area.  Completed
areas were hydroseeded  or  hand  seeded  with  bluegrass.
                                   11-12

-------
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                                               11-13

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             FIGURE 11-5

            NARROW TRENCH
         MONTGOMERY COUNTY,  MD
              FIGURE 11-6

SLUDGE BEING PUMPED INTO NARROW TRENCH
        MONTGOMERY COUNTY,  MD
               11-14

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                               FIGURE  11-7

            APPLICATION OF COVER AND EXCAVATION OF NEW TRENCH
                          MONTGOMERY COUNTY, MD
Relevant operational procedures are summarized  below:
        Sludge to groundwater      -  3 ft  (0.9 m)
        Soil cover thickness       -  3 ft  (0.9 m)
        Sludge application         -  1,275 yd^/acre  (2,400 nrYha)
                                      (usable area)
        Trench depth               -  3 ft  (0.9 m)
        Sludge time of exposure    -  <1 day
        Total soil usage
          (sludge:soil)            -  1:1
The following equipment was used at the facility:


           No.                        Machine
           2            Rotary trenching machines
           2            Track type front end loaders
           2            Pumps and air compressors
           9            Tractors
          24            Trailers


                                   11-15

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Following is an outline of problems, together with solutions, encountered
in the operation:


     •  Frozen ground

        - top 3 ft (0.9 m) of soil was removed and stockpiled

     •  Possible odors near site

        - lime was placed  on  spills  and  masking agents were sprayed  from
          trucks

     t  Mud and dust

        -  mud wash pad at receiving sites used during  inclement weather.
           Water  and  liquid  asphalt sprayed  on access  roads  during  dry
           periods.


     11.3.7  Monitoring
The county  monitors  all  wells  and  surface water  within  the vicinity  of
the site for  organic  and  inorganic  pollutants.  Sampling for the  consti-
tuents found  in  Table 11-5 is conducted  at  a frequency varying from  one
month to three months depending  on  the constituents.   To date no  conta-
mination of surface  or groundwater  has been  noted.   The location  of  the
wells is detailed in  Figure 11-3.
     11.3.8  Costs


The site cost for each  wet  ton of sludge was $31.64  ($34.88/Mg)  and  each
dry ton  cost  $143.82   ($158.57/Mg).   Total  disposal  costs  were  $49.54
($54.62/Mg) per wet ton  of  sludge or $227.07 per dry ton  ($254.00/Mg)  of
sludge.    This  relatively  high  figure   reflects  the  elaborate  on-site
safeguards  and  monitoring,  the  thorough  selection  process,   and   the
relatively  long  haul  distance.   Another  factor that contributed  to  this
cost was  the high  price  of land  in  Montgomery County.   A breakdown  of
on-site and hauling costs is provided below:


                                    Yd3       Dry ton      Wet ton

          Hauling costs              $15.92       $83.25      $17.90

          On-Site costs              $28.14      $143.82      $31.64

          Total                      $44.06      $227.07      $49.54
                                    11-16

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            TABLE 11-5

SAMPLING  AND  ANALYTICAL  PROGRAM
    AT  MONTGOMERY  COUNTY,  MD
Monitoring
Type
Groundwater
and surface
water
Well/Station
No.
All wells,
domestic,
on-site
area stream
station
Sample Collection
Technique
Have made a sampl ing
device
Analyses
Parameter(s) Frequency
N03, Cd, Cu, Pb, 1 month
Ni, Cl, Zn, Ca,
Total P, Specific
Conductants, TDS,
TOC
                             Fecal Coliform,     1/3 month
                             Chlor HC,  Alk, TKN,
                             N02, N03,  N, S04,
                             Mn, Fe, Zn, Cd, Ni,
                             Cu, Pb, Hg, K, Mg,
                             Cr, TOC, NH3-N,
                             Hardness,  Cl, pH,
                             Ts, BOD, COD, P04,
                             Ca, Na, Specific
                             Conductance
                11-17

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11.4  Waukegan,  Illinois
     11.4.1  Background  and  History
The Newport  Township landfill, located  near  Waukegan, Illinois,  receives
sludge  generated by four  treatment  plants that  serve a domestic  popula-
tion of 232  000  with an  additional  industrial inflow  equivalent  to 28  000
residents.   The  industrial  inflow originates primarily from  a  naval  base,
a pharmaceutical  company and a variety  of metal  finishing plants.   There
                                 plants  and  one   pretreatment  wastewater
                                 Sanitary  District.   The  three   advanced
                                sludge,  followed  by biological  denitrifi-
                                 the   pretreatment  plant  uses   trickling
filters.   Figure 11-8 and  Table 11-6  outlines sludge  processing  at  the
wastewater  treatment plant.   After  initial  processing,  sludge  from  the
four  plants  is  taken  to  a processing  plant  in Waukegan  where  it  is
elutriated  and conditioned  with  lime  and ferric  chloride.    It  is  then
dewatered to  about  22%  solids by vacuum filtration (Figure 11-9)  prior to
landfill ing.   The  site  commenced operations on July 8, 1974.
are  three  advanced  wastewater
plant  within  the  North  Shore
treatment  plants  use activated
cation  and  sand  filtration;
                               TABLE 11-6

          DETAILS  ON  SLUDGE TRANSPORTED FROM ORIGINATING  PLANT
                 TO SLUDGE  PROCESSING UNIT AT WAUKEGAN,  IL
      TOTAL
                                 Sludqe Generation Rate
Plant Plant
No. Name
1 Waukeqan


2 Clavey
Road
3 Gurnee
4 North
Chicago
Sludge
Source
Primary
Waste
Activated
Imhoff
Settling
(all)
(all)
(all)
Ibs per
day (dry
solids
weiqht)
13,530
15,409
13,530
11,968
22,965
1.420
qallons
ner day
(wet
volume)
32,446
25,177
27.038
48,643
55,071
3,405
Transport to Processing Unit
days
per
week
5
5
5
5
5
5
mode
8 in. diameter
pipeline
8 in. diameter
pipe! i ne
8 in. diameter
pi pel ine
5,500 gal tank
trucks
8 in. diameter
pi pel ine
5.500 qal tank
trucks
transport
distance
(miles)
<1
<1
<1
22
7.5
5
                               78,822
                                        191,780
     1  Ib = 0.454 kg
     1  gal/d = 3.785 L/d
     1  in. = 2.54 cm
     1  mi = 1.609 km
                                    11-18

-------
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                                                        11-20

-------
     11.4.2  Site Description


The  site  has  an  area of 282.8 acres  (114 ha),  with  200  acres (81  ha)  to
be filled.  Soils consist  of 2 ft  (0.6 m) of  topsoil,  then  20 to  25 ft  (6
to 8 m)  of silty clays, followed by  6 to 15  ft  (2  to  5  m)  of tight  blue
clay.  The southwestern  part of  the site is a flood plain  with slopes  of
less than  1%.  The  flood  plain is  not being used  for filling  operations.


     •  Topography           - slopes average 4%; vegetation  sparse;
                               flood  plain  on west  end has  1% slopes
        Soil type            - silty  clay
        Depth to groundwater - 31  to  40  ft  (10 to 12 m);  perched
                               table  at  25 ft (8 m)
        Groundwater  use      - aquifer provides potable water
        Freezing days        - 140  days  per year
        Precipitation        - 32  in. per year  (81  cm/yr)
        Evaporation          - 39  in. per year  (99  cm/yr)
     11.4.3  Site Selection


The  first  step  in  the selection  process was  to  identify  the  disposal
alternatives.  The options included:


    1.  Incineration of dewatered  raw and digested  sludges

    2.  Disposal of  digested,  dewatered  sludge on cropland by discing  or
        plowing  into the soil

    3.  Disposal of  digested liquid  sludge on  cropland  by  irrigation

    4.  Landfill ing  of dewatered raw and digested sludges


Figure 11-10 illustrates the estimated costs of treatment, transportation
and  disposal  for each alternative.   On the  basis  of  these  cost  evalu-
ations and  a  maximum distance of  25 mi  (40  km)  to the landfill,  it was
determined that  sludge landfill ing would provide the  most cost  effective
alternative for  ultimate disposal.


Following  selection  of the  disposal alternative,  eight  potential sites
were  chosen  based on  available data  on soils,  geology  and  topography.
Ultimately the Newport Township  site was selected for  intensive  investi-
gation, based on the following considerations:
                                   11-21

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                               FIGURE 11-10

                   COMPARATIVE COSTS OF SLUDGE  DISPOSAL
                         WITHOUT PHOSPHORUS  REMOVAL
                               AT WAUKEGAN,  IL
                       170
                  LL. f
                  O<
                       160
                   UJ
                  3s
                  Q o
                    _i
                  UJ O
                  O CO
                  t/5 Q
                                          QUnNTtTIES FIOM NSSD
                                          PLiiNNING AREA WITHOUT
                                          PHOSPHATE REMOVAL.
                               25
                                           75
                                                  100
                                                        125
                                MILES  TO DISPOSAL SITE
                                 FROM WAUKEGAN STP
                                     (ONE WAY)
     •   Short haul  distance  (10  mi  or 16 km)

     t   Availability of the  land for purchase

     t   A  large negative reaction from the public was not  anticipated


Accordingly,  an option to  purchase  the  land was  acquired  for this  site,
and  hydrogeological  investigations   were  begun  to  determine its  environ-
mental acceptability.  After discussions with the Illinois  Sanitary Water
Board  and  the  Illinois  State  Geological  Survey  regarding  the  data  re-
quired to  obtain preliminary approval of  the  landfill  site, the  District
proceeded  with  the  necessary soil  borings and  laboratory tests.   A total
of nine  borings to a  depth  of up  to 52  ft  (16 m) were  performed  at  the
site.
                                    11-22

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By the  end  of 1970 the District contracted to  have  topographic  maps  made
of the  property.   The  maps  of the 450 acre area were  prepared at  a  scale
of 1  in.  =  1  000 ft (1  cm  = 120 m)  and  2  ft  (0.6  m)  contour  intervals.
These  maps  were  provided   to  a  consulting   engineering  firm  that  the
District  had  contracted  to  prepare  design and operation  plans  for  the
site.
      11.4.4  Design
The design  had  to  accomodate  the  following  regulatory requirements  of the
Illinois  State  Environmental  Protection  Agency.
     t   It  had  to follow the  "Rules  and Regulations for  Refuse  Disposal
         Sites  and  Facilities"  (general  operational  requirements  -  no
         large impacts).

     •   It  was  required that  a  150 ft  (46  m) buffer  be placed  between
         sludge  deposits  and the property line of any residences  and  the
         center  line  of any  county  roads.

     •   The  site  could accept  only filter  cake  sludge  conditioned  with
         ferric  chloride and  lime.

     •   It was  required that groundwater monitoring  wells  be  installed at
         state-approved  locations.    Monitoring  for  22  contaminants  was
         required  annually;  5 parameters  quarterly.

     •   It  was   required  that  gas  monitoring  wells  at  state-approved
         locations be  monitored  for methane,  carbon dioxide,   nitrogen  and
         oxygen.


Based on information  obtained from  borings, excavations were  limited  to  a
15 to 20 ft  (5  to 36 m)  depth.  At this depth,  at  least  20  ft (6 m)  of
silty clay  with  a  low  permeability would separate  sludge deposits  from
groundwater.


Other design considerations  included:


     •   Relatively low solids sludge (22%)

     •   Deep, well protected aquifer

     0   Stable soil  for trench sidewalls

     •  Maximum site  usage.
                                   11-23

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As  a  result of  these considerations  and  the  site  characteristics, the
District chose wide trenches as the disposal method.


In  order  to determine the  stability  and  seepage  characteristics of the
soil,  the District excavated two test pits on  February 9 and  10,  1972.


Each pit was 24 ft by 50 ft (7 m by 15 m)  at  ground  level.   The  slope  of
three  sides was  approximately  1:1,  the  fourth  was  1  horizontal  to  2
vertical, with a  depth of  12  ft (4 m).  All  observations indicated  that
groundwater  seepage  was  not  excessive,  and  that  the cuts  were stable
since no sloughing or caving of the banks  was observed.
An application  for  a  permit to  install  and  operate  a sanitary  landfill,
together  with  a  detailed  installation  and  operating  plan,  was   then
submitted  to  the Illinois  State Environmental  Protection Agency.    The
permit was  issued  on  March 2,  1972.   In September  1973,  a contract  was
awarded  by  the  District for  preparation  of the  site  in accordance  with
plans and specifications prepared by the consultant.
     11.4.5  Public Participation


          11.4.5.1  Public Interaction During Site Approval


Although when  the District initially selected  the  site they  anticipated
little  public  resistance, protests  began  following  reports  of the  pro-
posed  landfill  operation  in  the media.   However, the District  performed
detailed environmental  impact  investigations  and prepared an  operational
plan  designed  to  minimize impacts.   The  District  worked  closely  with
various regulatory authorities  including:


     •  Illinois  State  Environmental Protection  Agency

     •  U.S. Department of Agriculture, Soil Conservation  Service

     •  Lake County Illinois Soil and Water Conservation District
These  authorities  reviewed and provided  input  to  site plans and  reports
throughout  the process  and  as a  result of  their  support,   the  public
reaction became less negative.
                                   11-24

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          11.4.5.2  On-going Public Relations


Operational  features designed  to minimize  public  resistance  were:
     •  Application  of  cover  over  sludge  throughout  the  day  in  warm
        weather to minimize odors.

     0  Application of  lime over  sludge in haul  vehicles at all  times  to
        minimize odors.
As a result, the only  complaints  received  to date have been from  a  resi-
dent  whose  property  is  literally  surrounded  by  the  landfill.    The
resident's  complaints  are generally  justified,  and they  have been  con-
structive  in nature.   In general, they have centered on odors  and  noise;
consequently,  dumping  and operating  procedures  have  been  restricted  and
currently  run  from 7 a.m.  to 4 p.m.
     11.4.6  Operation
Site  preparation,  sludge  loading  and  transport,  and  the   operating
practices  employed are  discussed  in  sections  11.4.6.1,  11.4.6.2,  and
11.4.6.3,  respectively.   Operational  considerations are presented  below:


        Sludge to groundwater     - >10 ft  (>3m)
        Soil cover thickness      - 5 ft  (1.5 m)
        Sludge application        - 9,100 yd3/acre  (17,200 nr/ha)
        Fill depth                - 14 ft (4 m)
        Sludge exposure           - <1 day
        Total soil usage
        (sludge:soil)               - 1:0.6
          11.4.6.1  Site Preparation
The existing on-site barn, silo, and minor out-buildings were demolished.
The remaining  farmhouse  was  used  as  an office.   Structures for  storing
sludge  and  on-site  equipment  were  constructed.    A paved,  all   weather
access  road  was  constructed  to  within  several  hundred feet  of the dis-
posal  area. Approaches to  the  disposal  areas were  covered  with sand  and
gravel.   A  6 ft  (2  m)  'fence  was  provided for the area south  of Ninth
Street  (Figure 11-11).   Lighting was  installed  around on-site structures
and sewer, water, and telephone  services were in place at the farmhouse.


Prior to  excavating  a  trench the  top 3 ft (0.9 m)  of  soil  was stripped
and stockpiled.


                                   11-25

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                                       11-26

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           11.4.6.2   Sludge Loading and Transport


Sludge  from  the vacuum filter  at  the Waukegan  sludge  processing  unit is
transported  via a conveyor  belt  that moves from  end  to  end of a  30 yd^
(23  nr)  open dump truck.   Thus, sludge  is  spread evenly over  the  bed of
the  truck.  There are  five open-top  dump  trucks with sealed  tailgates,
and  each  makes  about 5  trips to the landfill each day.   The one-way haul
distance  is  10  mi   (16 km)  and  the  haul  roads  are  suitable for  truck
traffic.
           11.4.6.3  Operational  Procedures


Individual trenches 20 ft  deep,  70  ft  long and 22 ft wide (6 m deep, 21  m
long,  and  7  m wide)  at the top  are excavated by  a  large backhoe/excava-
tor.   Sidewalls  are straight  on  all  but  one side; the 70 ft (21  m)  length
on the  side  where dumping  is  done  has  a  6  ft (2 m) wide step halfway down
for added  sidewall stability.   Thus, the bottom  trench  width  is  16  ft (5
m).   Consecutive trenches  are constructed  with  the 70  ft (21   m)  sides
parallel.    Twenty ft  (6  m)  of solid  ground  is  maintained  between  the
parallel  trenches  and consecutive  trenches proceed  in  a line to  form  a
single  row (Figure 11-11).  After  completion  of one line  of  trenches,  a
second  line  is begun  (as  shown in  Figure 11-12)  to  the  side of  the  first
line.   Five ft  (2  m)  of solid  ground is  maintained  between  adjacent
rows.   The trenches  are  graded so  that  leachate can be  collected  at  one
end of  the trench and  returned to  the  Waukegan plant for treatment.   Haul
vehicles  back up on  prepared sand  and  gravel access  roads to  the  long
sides  of  each trench,  and sludge is dumped by the  trucks  in  progression
from one end  of  the 70 ft  (21  m) length  to  the other.


Usually the  consistency of the  sludge  is  such that  it  flows out  to  an
even   grade  inside   each   trench.     However,  the   bucket   of   the
backhoe/excavator is  used  to  spread the sludge  evenly at the end of  the
day.   One  day's  sludge usually accumulates  to  a 2 ft  (0.6  m)  thickness.
Filling proceeds to within 2  ft  (0.6 m)  of  the  surface  before proceeding
to a new eel 1.
At the end of each day, a 6 to 8  in.  (15 to 20 cm) soil cover  is  applied
over the  sludge.   After filling  has proceeded to  within  2 ft  (0.6  m)  of
the subsurface  (usually at  the end of a week), a  5 ft  (2  m) cap  of top-
soil cover (previously  stockpiled)  is  applied  to 3 ft  (0.9 m)  above  grade
by the backhoe.  After  initial  settlement the trench is final  graded  and
compacted with  small  bulldozers  (including  a  D-3  and a D-5).  Additional
operational  characteristics are detailed  below:
                                   11-27

-------
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                                                     11-28

-------
The equipment and personnel at the site are as follows
        Equipment

        1 - Backhoe/Excavator  (Northwest with 1.5 yd3
            bucket)
        1 - Front-end Loader (Hough with 2 yd^ bucket)
        1 - Bulldozer (Caterpillar D-3)
        1 - Bulldozer (Caterpillar D-5)

        Personnel

        1 - Superintendent
        3 - Equipment Operators
        1 - Laborer
Problems encountered during  the  operation  of the landfill, together with
controls are detailed below:
        Problem:   Freezing  temperatures  make  excavation  of  cells  and
        placement  of  stockpiled cover  impossible.   Snow and  rain make
        access to  cells by  haul  vehicles and site operation by equipment
        difficult.

          Control:  During  inclement  weather, soil  is  stockpiled  on the
          site  inside  a  sludge storage building  accessible  via  paved
          roads.  This building is a steel frame structure 50 ft by 50 ft
          by 30 ft (15 m  by 15 m by 9  m) high.   It  is  constructed on a
          concrete slab with  concrete  s-idewalls  extending  3 ft  (0.9 m)
          high.  A trench drain is located  in the  middle of this slab to
          collect  sludge  moisture.   This   leachate  is  directed   to  an
          underground 10,000  gal  (37,850 1)  storage tank.    Leachate is
          pumped  out  of  the tank as  necessary  and  transported via tank
          truck to the  Waukegan Plant  for  treatment.   In  poor weather,
          all   sludge  delivered to  the  site  is  dumped
          which prevents the addition of moisture  from
          controls odors.   When weather  improves, the
          back into dump trucks with  front-end  loaders
          cells.
into the  building
precipitation  and
 sludge is  loaded
and hauled  to  the
        Problem:  Soil  runoff from denuded fill areas.

          Control:   Fill  areas are  seeded  with grasses  soon  after com-
          pletion.   All  on-site  drainage is  channeled  through sod-lined
          ditches to a collection pond.
                                   11-29

-------
        .	   Odors  from  sludge  during  transport,  from  uncovered
        sludge in cells during warm weather, from sludge spills, and from
Problem:
sludge i..
equipment
          Control:   Initially sludge transport  was  to be  in  dump truck
          trailers covered  with  tarpaulins  for  odor  control.   However,
          this  caused  operational   difficulties  and  transport   is  now
          accomplished  in open-top  trucks.  However,  after loading, the
          sludge  is covered  with  a  layer of lime  for  odor control while
          in transit.   In  warm weather,  sludge  in the cells  is  covered
          during  the  day as  well  as at  the end  of the  day.    Lime is
          sprinkled over  any sludge spills.   The backhoe  bucket (which
          comes into contact with sludge)  is buried in soil at the end of
          the day to minimize odors.

     •  Problem:   Mud  from  site  is tracked onto adjoining  roadways by
        haul vehicles.

          Control:   A washrack is  located at the Waukegan Sludge Proc-
          essing  Unit.   It  is  used  to  clean  haul  vehicles   in  wet
          weather.

     •  Problem:   Noise of  haul  vehicles and on-site  equipment  bothers
        near-site residents.

          Control:   Per  agreement   with   nearby  residents, hauling  and
          operation is confined to between 7 a.m. and 4 p.m.
Figures  11-13  through 11-16  illustrate  equipment and  operations  at the
Waukegan site.
     11.4.7  Monitoring


Background  samples  were  taken from all  wells  prior to initiating opera-
tions  so  that   baseline  conditions   could  be  established.  Subsequent
monitoring  has  not  detected any contamination of  groundwater  in on-site
wells  nor  has   water  from the  collection  pond   and drainage  ditches
contaminated  surface  waters.    Establishing  initial   conditions  proved
valuable  since  one  of  the  local potable wells showed contamination that
could have  been attributed to  sludge  disposal  but was  known  to precede
disposal operations as a result of initial tests.


The  number, location,  and  function  of  the  monitoring wells  was estab-
lished  in  conjunction  with  the Illinois  State  Environmental  Protection
Agency.   Figure 11-11  illustrates the  location  of the  wells  and Tables
11-7, and 11-8 detail the wells and monitoring parameters.
                                   11-30

-------
           FIGURE 11-13

         STOCKPILING SOIL
           WAUKEGAN, IL
           FIGURE 11-14

UNLOADING SLUDGE INTO WIDE  TRENCHES
              WAUKEGAN, IL
                11-31

-------
    FIGURE 11-15

PLACING INTERIM COVER
     WAUKEGAN, IL
     FIGURE 11-16

 PLACING FINAL COVER
    WAUKEGAN, IL
         11-32

-------
                             TABLE  11-7

   SUMMARY OF GROUNDWATER  AND GAS  WELLS AND SURFACE WATER STATIONS
                            AT WAUKEGAN, IL
Relation to Fill Well
Monitoring
type
Groundwater











Gas
Leachate




Surface
Water

Well /station
no.
OW-1
OW-2
OW-3
OW-4
OW-5
OW-6
OW-7
OW-8
OW-9
OW-10
5 Potable
Wells
Gas Well 1
Sludge cell
Tank under
sludge
storage
building
Runoff pond
Drainage
ditches
Location
(up- or down-
gradient)
Down-gradient
Down-gradient
Up-gradient
Up-gradient
Up-gradient
Up-gradient
Up-gradient
Down-gradient
Down-gradient
Down-gradient
Down-gradient

In-sludge

—




~

Specifications
Total Depth below
Distance depth groundwater Drill rig
(ft) (ft) (ft) used
200 30
100 30
100 30
20 30
100 30
100 30
100 30
100 30
100 30
100 30

-------













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-------
      11.4.8  Costs


A  breakdown  of  the  on-site  costs  reveals  that  the  cost  per  dry ton  of
sludge  was  $10.61   ($11.70/Mg).     The   costs   were  calculated   in  the
following  manner:    first  capital  expenditures  were divided  by the  total
amount of  sludge received  over  the life  of the  site;  next  operating  costs
were divided by  the  amount  of  sludge  received  for the  period  considered
(6 months  in this  case);  finally the  figures were  added  to arrive at  the
total  cost per  unit  of sludge  (excluding hauling  costs).   The intensive
use  of  the  available   land  contributed  to  this   relatively  low  figure.
The  following   tabulation  is   a  breakdown  of   the  costs by  category.
Hauling costs have not  been included in  the total cost.
                                              Total Cost     Unit Cost
                                                 (T)($/dry ton sludge)

                Site Capital Costs

                Land                            $ 450,000      $2.25
                Monitoring Wells                      12,000       0.06
                Site Preparation	          328.000       1.64

                Total Capital Cost                  $ 790,000      $3.95


                Site Operating Cost (October 1977 through March 1978)

                Labor                           $  18,200      $3.64
                Equipment Depreciation                  16,450       3.29
                Administration                        7,300       1.46
                Maintenance                          6,850       1.37
                Laboratory                           1,450       0.29
                Fuel                                1,250       0.25
                Operating Materials & Supplies               900       0.18
                Miscellaneous	             650       0.13

                Total Site Operating Cost             $  53,050     $10.61
                                      11-35

-------
11.5  Colorado Springs, Colorado


     11.5.1  Background and History
The  Colorado  Springs landfill  is  located on  Drennan  Road near Peterson
Field.   The  operation uses  two  landfill ing  methods:   narrow trench  and
wide  trench.   The  focus  of  this  study  will  be restricted  to  the wide
trench operation.   The  current flow of the  treatment  plant is 24  Mgal/d
(1.1  nr/s)  and the  plant is  designed to  handle up  to  30  Mgal/d  (1.2
nr/s)  from a  population  of  230,000.    Industrial  impact  is presently
being  studied, but  Colorado  Springs  does  not  require  pretreatment  of
industrial effluents at  present.    In  general,  the  sludge  has  a  lower
heavy metals content  than typical  municipal  sludge.   The  treatment  plant
has bar  screen separation, primary clarifiers, and waste  activated  sludge
treatment.  Using  gravity thickening and  vacuum filtration the sludge  is
dewatered to about 20 to  25% solids.  Although the site  began operations
in  1970,  wide  trench disposal  did  not begin at  the  site until July  1976
and terminated on December 19, 1977.
     11.5.2  Site Description
        Topography            - rolling  hills  <8 % slopes
        Groundwater use       - windmill  aquifer - provides  drinking
                                water
        Soil type             - silt and  clay
        Depth to groundwater  - >10 ft  (>3 m)
        Freezing days         - 120/yr
        Precipitation         - 13 in./yr (51  cm/yr, mostly  snow)
        Evaporation           - 60 in./yr (152 cm/yr)
     11.5.3  Site Selection
The Peterson  Field site was selected  because  it offered significant  ad-
vantages:
     •  Extended site life
     •  Land was owned by the city
     t  Short haul distance
     •  Site was fenced and area was  sparsely  populated
After  the  selection was  made  operations were  begun  immediately.   There
were  no further  selection  criteria  considered  and  no  preparation  of
design  or  operation reports.   Interaction  with local, state and  federal
government  was limited.   Although  not  employed as  selection  criteria,
both the amount  of  soil  available  and  the  topography were favorable  for
landfill ing.

                                    11-36

-------
           11.5.4   Design


There  were no  design  plans  or site  alterations made prior to initation of
operations since  the  site  was  relatively flat  and  required  no  altera-
tions.   Wide trench operations  were  restricted to upland areas  and  sur-
face  runoff was controlled by  the  orientation  of trench and  fill  (out-
lined  in  more  detail  in Operation 11.5.6).
      11.5.5  Public  Participation
Public  interaction  did  not begin until a  few years after the  opening  of
the  site,  when a housing  development  was  built  near  the site  and  along
the  haul  route.    The   residents  complained  of  odors  from  accumulated
sludge  piles.   Following those complaints city  officials  instructed  site
personnel  to  cover  sludge  as  it  was received.    However,  complaints
continued  from  both  nearby residents  and airport officials.   Accordingly,
city officials  decided  to  relocate  the site  in December  1977,  despite the
fact that  a  considerable amount  of  usable  area remained.
     11.5.6  Operation


The  site  operated 7  days  a  week  from  6  a.m.  till  10  p.m.   The  wide trench
operation  received a total  of 6,200 dry tons (5,624 Mg)  of  sludge with  a
solids  content  of 22%  over the 17-month  life  of the  operation.     Site
preparation,  sludge  transport  and  disposal  operations  are discussed  in
the  following sections.
          11.5.6.1  Site Preparation
Fencing  and  other  facilities  were in place  at  the inception of  the  dis-
posal  operation.   The site's  topography was compatible with  the  disposal
method  and  vegetation was  sparse; consequently  excavating  and  grubbing
were  not necessary.   Preparation consisted  mainly of  digging  the  wide
trenches.   Contractors did the excavations  which were 60  to 80 ft  wide
(18 to 24 m); 600 to  800 ft (183  to 244  m)  long;  and 6 to 8  ft  (2 to  2.5
m) deep.  The trenches were located on  upland  areas  with  the  long axis of
the  trench  perpendicular to  the  slope.  The  location of  these pits  on
high ground, and the  soil stockpiles on  the  uphill side  prevented accumu-
lation of water.  Between 20  and  25 ft  (6 to 8  m)  of ground  separated  the
trenches.
          11.5.6.2  Sludge Loading  and Transport


The one-way haul distance was 7  mi  (11  km)  and the roads were  compatible
with heavy truck traffic.   In  addition,  the route traversed a  rural  area
                                   11-37

-------
and  minimized  the  impact  of  transport  on  residents.    The  sludge was
placed  into  uncovered  dump  trucks  with sealed  tailgates  and  varying
capacities  directly from the  vacuum  filters.   The three  vehicles  made a
total of ten  trips  per day.
          11.5.6.3   Operating Procedures
Dump  trucks hauling  sludge  entered the  trenches  through the  ramps and
deposited  sludge  at  the opposite end  as shown in Figure  11-17  and 11-18.
Dumping  took  about 2 or 3  minutes  maximum for  each load.   Each load was
dumped  on  fresh  ground.    That  is,  sludge  loads  were  not dumped  atop
previous  loads.   Typical  pile heights were 4  ft  (1  m).
                              FIGURE 11-17

                     SCHEMATIC OF OPERATING  PRACTICES
                          AT COLORADO SPRINGS,  CO
                                               DUMP TRUCK
                                               ACCESS RAMP
                   COVER SOL
                   STOCKPILE
                BULLDOZER
                COVERING SLUDGE
                                    PLAN VIEW
                   COVER SOIL
                   STOCKPILE
                                      SLUDGE
                                     SECTION A-A
Two bulldozers  applied daily  cover  over sludge piles.   Usually one dozer
pushed the  cover soil  stockpiled  on  one long side of  the  trench out over
the 4 ft  (1  m)  high sludge  piles, while the other dozer pushed the cover
soil from the  other long side.  Cover was  usually graded 4 ft  (1 m) thick
(see Figure 11-17 and 11-18).
                                    11-38

-------
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                                            11-39

-------
It was found  that this  thickness  was  required  before  the  soil   could
safely support equipment.
Additional operating characteristics  are detailed  below.
        SIudge to groundwater        -  >5 ft  (2 m)
        Soil cover thickness         -  4 ft  (1 m)
        Sludge application           -  4,700 yd3/acre  (8,883  m3/ha)
        Fill depth                   _  4 ft  (1 m)
        Sludge exposure  (days)       -  <1 day
        Total soil used
        (waste:soil)                 -1:1
The information  below outlines the  equipment and  personnel  required  to
operate the site.
         Equipment              Time	       Personnel

     Caterpillar D-6        1/2  (20 hrs/wk)           1/2
     Caterpillar D-8        1/2                       1/2
     Scraper	        1/4  (10 hrs/wk)           1/4

        TOTAL               1-1/4  (50 hrs/w)        1-1/4


The equipment used  was  not  specifically selected for this operation,  but
was chosen from available equipment already  owned by  the  municipality  and
was used for  both  narrow  and  wide  trenching  and  occasionally,  other
operations.
The only facilities  located  on  the  structure  were  a  camper  shell  and
chemical toilet.


Following  is  an  outline  of problems associated with the  operation  of the
site and the  controls  used:

     o  Problem:   Wet  and  snowy  weather  causes access  problems  for haul
        vehicles.   Access  roads  on  the  site  are  dirt  (not  paved)  and
        become slippery  or muddy  (in  snowy  or wet weather,  respectively).
        Driving  loaded trucks on public  paved roads  in such weather  is
        also  hazardous.   This has resulted in  several  small  accidents  in
        the past.

           Control:   Hauling   is  discontinued  and   site closes  down  in
           severe  weather.  This  happens  for  an average of 10 days each
           year.   The  treatment   plant  has  about 30 to  40 days  storage
                                  11-40

-------
         capacity  for sludge  when the  site  is  closed.
         tractors can  be  used  and have been used to  haul
         sludge when  site  operations  resume.
                                            Further,  con-
                                           the backlog  of
    •  Problem:   Despite  daily cover, because sludge  is  not  digested or
       otherwise  stabilized,  odor can be  a  problem in warm  weather  and
       complaints are  received  from  nearby residents.

         Control:   Cover  was  applied several times during  the  course of
         the day  in  warm  weather.

    •  Problem:   Rainfall  which collects  in  the  pits  caused  problems
       with haul  vehicles  becoming stuck  in  the  mud.   Dust  was  a problem
       in dry weather  and  nearby residents complained  regularly.

         Control:  A layer of  fresh  dry soil was applied in  the pits to
         improve  maneuverability by  haul  vehicles  in wet  weather.    A
         water  tank  truck with  a spray  bar was  used  to  apply  water to
         on-site  dirt  roads in  dry weather.

    •  Problem:   Strongest complaints  from  nearby residents  concerning
       the  subject  site were  directed  at  noise  from  equipment  and  from
       haul  vehicles  on   the   site,  and  increased  traffic  from  haul
       vehicles on  public  roads.

         Control:   None practiced to date.   Public officials  attempted
         to placate  nearby residents by assuring them that the  disposal
         operation were soon to be dis con inued at the  site.

     t  Problem:   Flies  were  attracted  to  and  breed in  sludge at  the
        site.     Nearby   residents   complained,  particularly   in   warm
        weather.

          Control:   Sludge was  sprayed  with a disinfectant  in  the summer
          to keep the  flies down.  This disinfectant  is the type normally
          used  on livestock to  protect them  from flies.
Figures  11-19
site.
and  11-20  illustrate  the operational  procedures  at the
     11.5.7  Monitoring


Several months  after  the  site was established, the city  began  to  monitor
existing on-site  wells to determine the  impact of the  site, if  any   nn
                                                        on
       +j   ----------  - -   ___.   ._  _.._
the Windmill Aquifer.  This was motivated  by  a  desire  on  the  part  of city
officials to allay public concern  and  hence extend  the site  life.   Figure
11-21 shows the location of the monitoring wells.
                                  11-41

-------
             FIGURE  11-19

             WIDE TRENCH
         COLORADO SPRINGS, CO
          FIGURE 11-20

APPLYING COVER TO SLUDGE DEPOSITS
       COLORADO SPRINGS, CO
               11-42

-------
                             FIGURE  11-21

                            SITE LAYOUT PLAN
                         AT COLORADO SPRINGS,  CO
                                 DRENNAN ROAD
                                               LEGEND

                                              '0 MONITORING WELL
     11.5.8  Costs


The total  cost  per dry ton  of  sludge including  hauling  costs was $25.32
($27.92/Mg).  The costs were derived by dividing  the quantity of sludge
received  in  a year  by  the annual haul  and  operating costs.   Site  costs
were significantly reduced  since  the land was  owned  by the  municipality
initially.   Also,  investigations indicated  that extensive environmental
controls  were not necessary.  Together with the  short haul distance  these
factors contributed to  the low handling costs outlined below.
                                   11-43

-------
                                             Total Cost   Unit Cost
                                               [T](J/dry ton)

                   Haul Cost                    $ 87,600    $20.00

                   Site Capital Costs (None since land was free)

                   Site Operating Cost

                     Equipment and Personnel
                      for Trench Excavations       $  7,700    $  1.76

                     Equipment and Personnel
                      for Covering Pits           $ 15,600    $  3.56


                     Total Site Operating Cost      $ 23,300    $  5.32


                   Total Cost                   $110,900    $25.32
The costs  presented are based  on  the  operating cost  of the  landfill  for  a
single  year  and  the   total   amount  of  sludge   received   (4,380  dry  tons
(3,970  Mg))  for a  one  year period.
                                            11-44

-------
  11.6   Denver, Colorado
       11.6.1   Background and History

 The  Denver  disposal  site  is  located  26.2  mi   (42  km)  southeast  of  the
 Metro  treatment plant  off state  highway 30  in the  Lowery Bombing  Range
 (LBR).    The  plant  processes  approximately 100  Mgal/d  (4.4  irr/s)  and
 serves  a  population  of  1,100,000.   About  15%  of  the  inflow  is  from
 industries,   including  slaughter  houses,  plating   industries,  chemical
 manufacturers, and office  buildings.  The  plant produces  thickened  waste
 activated  sludge  (WAS) and  the  Denver  Northside  (DNS)  treatment  plant
 contributes  primary digested  sludge.  This mix  is pumped  to a  processing
 building  where  lime,  ferric  chloride  and/or  polymers  are  added  to  aid
 vacuum  filtration.   The sludge has a  15%  solids  content  and  the  plants
 contribute  100 dry tons (90 Mg) per day  with the following constituents:
          Raw primary
          Anaerobic, digested
          WAS,  digested
          Fed 3
          Lime
40%
15%
45%
8-12% dry weight
20-30% dry weight
 Figure  11-22 outlines the  treatment processes  and  sludge characteristics
 of contributing plants.  The  site uses two  disposal  methods; the  primary
 disposal  method is an application technique that  incorporates the  sludge
 into  the  soil  by  cultivation.   The  alternate method,  area  fill  using
 layering,  is employed in  cold weather.   This  technique  was initiated  in
 1973 and  will  be the focus of  this  case  study.

                               FIGURE  11-22

                      WASTEWATER TREATMENT  FLOW  DIAGRAM
                         FOR DENVER,  CO  METRO  PLANT
                             To
                        Sludge Treatment
                         and Beneficial
                           Reuse or
                           Disposal
                DNS Digested
                Primary Sludge

                Primary Sludge
Influent
Wastewater
                               Waste Activated
                                 Sludge
                        Effluent
South Platte
River
                         Return Activated

                           Sludge
                                      11-45

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     VI .6.2  Site Description

The site has a total area of 1,450 acres  (587  ha)  and 650 acres (263 ha)
are being  used  for the  area  fill  operation.   The climatic  and physio-
graphic characteristics at the site are detailed below.


        Topography               - gently rolling hills;  low relief
        Soil type                - clay, sand and gravel
        Depth to groundwater     - 10 to 140 ft (3 to 43 m)
        Groundwater Use          - aquifer provides potable water
        Freezing days            - 240/yr
        Precipitation            - 14 in./yr (36 cm/yr)
        Evaporation              - 60 in./yr (152 cm/yr)
          11.6.2.1  Soils and Geology


The surficial  geology  of  the  area consists of  two  principal  units:    (1)
alluvium  consisting  of unconsolidated,  poor- to  moderately well-sorted
clay,  silt,  sand,  and gravel  of Pleistocene  and  Holocene  age  with a
maximum thickness  of  about  25  ft  (7.6 m); and  (2)  the undifferentiated
Denver  and  Dawson Formations  consisting  of  brown,   dusky-yellow,   and
blue-gray mudstone with  thin, lenticular beds  of  lignite  and gray sand-
stone.
The dominant  soils at the LBR  are  the  Fondis and Renohill  series.   The
Fondis  soils  are  deep well-drained soils  located  on  uplands, and formed
from  loessol  deposits overlying the Dawson  formation  (Pleistocene Age).
The Fondis  surface soil  is  about  10 cm  thick,  free of  lime,  very dark
grayish-brown and  silt  loam  or  silty clay loam  in texture.   The  subsoil
is  41  to 46  in.  (102  to  114  cm)  thick, contains  free lime,  is  dark
yellowish brown  in color and silt  loam  to clay in texture.   The Fondis
soils  have  a moderately  slow  permeability,  slow internal  drainage and
high  available  water holding  capacity.    The Renohill   series  which has
developed on the Dawson formation is a moderately deep well-drained soil.
The surface layer  is  about 4 in. (10 cm) thick,  free of lime, and  is dark
brown  loam.   The  subsurface  soil  is approximately 25  in. (63 cm) thick,
contains  free lime,  dark  brown to  dark  yellowish  brown in  color, and
ranges  from  a loam to  silty clay  loam  in texture.   Renohill  soils have
medium  internal   drainage,  moderately   slow  to  slow  permeability  and
moderate water holding  capacity.
     11.6.3  Site Selection
No site selection process was employed.  The city of Denver  purchased  the
land  in the  1950's  from  the Federal  government for the expressed  purpose
of solid waste disposal.   In  1969,  Metro acquired disposal  rights to  the
                                   11-46

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 land  from the city and county of  Denver.   As a  result,  no  pre-selection
 investigations  were  conducted.
      11.6.4  Design


There  was  no design  process,  but through trial  and error two  operating
methods  were established.   The first  was  a  land application  method,  the
second  an  area  fill  procedure  used  only  in  inclement  weather.    The
topography of the  site  was  conducive to  both  disposal  and  application.


      11.6.5  Public  Participation
Due  to the  remoteness  of  the  site there  was no  interaction with  the
public  during the  site  approval  phase.   Beginning  in 1972,  complaints
were  registered  by  residents  who lived  near  LBR.
As a  result, the  Arapahoe  County  commissioners  conducted  a public  hearing
and  invited  Metro to  attend.   The  complaints  centered  on  objectionable
odors  associated  with  the  site.   These  were  a consequence of unauthorized
operational  changes  in disposal  practices.   Metro  proposed the  current
method  of  disposal  at the  meeting  and  it was  approved.    Implementation
began  immediately.
     11.6.6  Operation
Sludge  disposal  began  in  1969  and  is  expected  to  continue  until  1980
giving  the  site  an 11  year life.  The  site  is  open 24 hours a day.   The
area  fill   operation  takes place  in  locations  where  the  topography  is
charcterized  by  rolling hills.  Operational  considerations are  outlined
below.
        Sludge to groundwater        -  10 to  140 ft  (3 to 43 m)
        Soil cover thickness         -  N/A
        Sludge application           -  9,000 ydj/acre  (17,010  nr/ha)
        Fill depth                   -  17.5 ft  (5 m)
        Sludge exposure              -  <1 day
        Total soil usage
        (sludge:soil)                -1:5


          11.6.6.1   Site Preparation


Large  earthen  berms  are  constructed  from  soil  excavated  onsite.   The
excavation occurs on the  top of hills,  thus  lowering  the overall eleva-

                                  11-47

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tion.    These   berms  are  constructed  in  an  Intersecting  orientation,
similar to a "tic-tac-toe" configuration.   The  berms  are  approximately  20
ft (6 m)  in  height,  several  hundred  feet in length,  and  approximately  15
to 20 ft  (4.6  to 6 m)  in  width at  the  top and  are  slanted slightly  to
allow for runoff of water.   The berms are constructed in the summer  when
conditions permit.


          11.6.6.2  Sludge Transport


The  distance  from the  sludge  source to  the  disposal site  is  26 mi  (46
km), one-way.  There are 27  to  30 loads  delivered daily.  Three  1978  Mack
Road Tractors  and  one  1975  IHC Road  Tractor  are  used to haul  the  sludge
and  smaller  dump trucks ha/idle the   sludge  on-site.   The  haul   vehicles
have Ji  capacity  of  40  yd1-5  (30  nr)  and  the  dump  trucks  hold  13  yd1-5
(10 m3}.


The  haul  vehicles  deposit  the   sludge into  sludge  storage hoppers at the
site.   It is then loaded into  the  smaller dump  trucks  and  delivered  to
the  sludge disposal area.
          11.6.6.3  Operational Procedures
The dump truck drives down  one  berm,  turns  around, and backs up down  the
other berm.   The  configuration  or orientation of  the  berms is such that
it cuts  down  on the  length and amount  of  time needed  for backup.   The
distance that the  drivers  have  to back up  is  also reduced, which  can  be
important at  night and/or when there  is  inclement  weather.
Sludge  is  dumped  from  the trucks  positioned at  the  edge of  the  berm.
The dozers  located below begin to mix the  sludge  back and forth  between
them with the soil  from  the berm  (Figure 17-23).   The  sludge  soil  mixture
is  generally one  part  sludge  to five or  six parts  soil.   As  the  berm
becomes shorter  and eventually meets  one of the intersecting berms,  this
intersecting berm  then becomes  the unloading-working area  (Figure  11-23),
thus  keeping the  backup distance to  a  minimum at  all  times.    Figures
11-24 and 11-25  illustrate equipment used at  the landfill.


Once an area  has been worked during the  winter  operation, the following
winter's operation occurs on top of  that,  thus,  in  effect,  burying the
sludge-soil  mixture  of  that   previous   year with  the   current  years'
sludge-soil  mixture.  This  layering  of each year's mixture combined  with
excavation  of the  soil   from  hilltops has  the effect  of  lowering the
hills, filling  in  low areas, and generally  creating  a flatter land  than
was originally present.
                                   11-48

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ro   LU
CM   Q-
 I    O O
UJ   >- C£.
OZ   
-------
      FIGURE 11-24

      HAUL VEHICLES
       DENVER, CO
     FIGURE 11-25

SLUDGE MIXING EQUIPMENT
      DENVER, CO
        11-50

-------
 The  following  equipment  and manpower  is used  primarily for  the  sludge
 landfill  operation.   However,  some of this equipment is also used for the
 sludge land  application that occurs during favorable weather conditions.
      Quantity

          1
          1
          1
          1
          1
          1
          1
          1
          1
          1
          3
          3
          5
               Description
        21
  1977 Dozer,  Fiat All is  w/ripper,  21C
  1977 Dozer,  Fiat All is,  21C
  1977 Grader, Huber,  850
  1972 Scraper, Michigan,  210
  1977 Front End Loader,  Case,  W24B
  1974 Office  Trailer,  Elder, 12E797551
  1975 Pickup, Dodge,  12E898962
  1975 Station Wagon,  Plymouth,  12E898961
  1977 Pickup, Dodge 4x4,  12M84227
  1975 Road Tractor,  IHC,  12E900075
  1978 Road Tractor, Mach,  12M103279-81
  1977 Dump Truck, IHC, 12M102631-33
  1973 Dump Trailer, Steco,  S3270

                     TOTAL
Purchase Price

$ 132,217
  119,403
   17,600
   40,000
   42,985
    4,455
    3,286
    4,830
    4,830
   25,950
   32,656/unit
   26,860/unit
    6,500/unit

$ 606,604
Personnel:
         1        Director
         1        Environmental  Agronomist
         1        Field  Supervisor
         1        Mechanic
        10        Field  Operators
         0.5      Secretary	

        14.5               TOTAL
     11.6.7  Monitoring
In  1974  to 1975,  approximately 5 years  after  disposal  began,  extensive
monitoring of soils, surface and  groundwater was  initiated  in  cooperation
lif 1 ^ n 4* M ^ MC^Q   C ^tYi rt T 4 « ^"i *•  ^v\f\ ^i/\irt/\ f* f\m 4  ^v^v^ii^llt/  £ r\ v*  r\ ^» r* \r\
     "t" rlpi
Samplings are done semi-annually for each.
Two wells are located  immediately down  slope  of  the  burial  areas.   Leachate
from the  sludge appears  to  be affecting  the water  quality  near  the  two
wells since  both  exhibit significant  deviations  from  background  wells,
particularly  with  regard  to  nitrates,  chloride, ammonia,  and magnesium.
Moreover, sulfate  and manganese concentrations  exceeded EPA's  recommended
drinking water  standards.
                                   11-51

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      11.6.8   Costs


The  major costs  associated with  this site  are outlined below.
                      item	    Total Cost      Unit Cost
                                      (I)        ($/dry tons)

                Hauling Cost                   (Unknown)

                Site Capital Costs   (Annual 1 zed and budgeted for 1978)

                Land                 60,000	      1.93

                Total Capital Cost        60,000          1.92

                Site Operating Costs    (Budgeted for 1978)

                Regular wages          349,361          11.19
                Overtime wages          19,707          0.63
                Materials              45,200          1.45
                Fuel, oil 4 gasoline      60,176          1.93
                Outside services         82,410          2.64
                Chemicals              4,200          0.13
                Electricity             6.420          0.20

                Total Site Operating Cost  567,474          18.17

                Total Cost            627,474          20.09
The  above costs represent the  annual  combined costs  of operating both  the
landfill and  land application  operation.   Separate  cost accounting  is  not
maintained  for the  two operations  and  therefore accurate cost  figures  on
the  landfill  operation alone  are not  available.  However, site  operators
report that  the total  annual  cost  of the  landfill  operation is  the  same
as the  total   annual cost of  the  land  application  operation despite  the
fact that  the  landfill  is  used  an  average  of  only  two months  (in  the
winter) each  year.  At 100 tons  per day the site receives 31,285 tons  per
year (100 t/d x 6d/7d  x 365  = 31,285).  Assuming  then,  that half of  the
total  site  cost   is  used  for  the  landfill   ($313,737)  and  that   only
one-sixth  of  the  total  sludge received is  attributable  to  the  landfill
(5,200 dry  tons (4,720 Mg)), the  cost of sludge  landfilling  is  $60.33  per
dry  ton ($66.51/Mg).
                                      11-52

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 11.7  Lorton, Virginia
      11.7.1  Background and History
 Located  off  of  Interstate  1-95,  south  of Washington,  D.C., the  Lorton
 site  is  a codisposal  facility  that  serves  5  treatment  plants  (from  4
 municipalities)  and provides  wastewater  treatment  for  approximately  2
 million people.  The industrial  inflow  is  relatively  small  since  the area
 is not industrialized.   The site  handles  58,630  wet  tons  (53,177  Mg)  of
 sludge per  year with  an average  solids  content  of  22%.    In addition,
 another 490,000 tons  (441,430  Mg)  of refuse  are  dumped  each year  at  the
 site.   Table  11-9  outlines  the  treatment  plants and  resulting  sludge
 types that are  processed  at the site.   Although  no regulations  exist  in
 Virginia  that  apply  directly  to  sludge  disposal,  the  facility  had  to
 receive authorization  from  the Virginia State  Bureau  of Solid Waste  and
 Vector Control  and  the Virginia  State Water Control Board  before  starting
 operations.  Ultimately,  permission was granted  to dispose  of up  to  300
 tons  (272.1  Mg)  of sludge  per day  at  the Lorton  site.   The  Washington
 D.C. federal  prison complex  is  located  on  the site.  Operations  began  in
 1972.
                                TABLE 11-9

         SUMMARY OF SLUDGE GENERATION AND TRANSPORT  TO  LORTON,  VA
Source
Washington
(Blue Plains)
Alexandria
Fairfax
County
Arlington
County
Sludge Generation
Sludge
Treatment
Anaerobic Digestion,
Dewatering
Anaerobic Digestion,
Dewatering
Anaerobic Digestion,
Lime and Fed
Addition,
Dewatering
Incineration
Percent
Solids
20%
20%
20%
95%
Quantity
(wet tons per
year)
12,313
10,554
34,006
1,759
Sludge
Vehicle
Tractor trailers with
sealed tailgates
Tandem-axle dump-
trucks with sealed
tailgates
Roll-off containers
on small trucks
Tandem-axle dump-
trucks with sealed
tailgates
ransport
Capacity
Each
(tons)
15
7-8
5
7-10

Average
Trips
Per Pay
4 or 5
7 to 10
25
1 or 2

Haul
Distance
Miles
20
12
8
18
1 ton = .907 Mg
1 mi  = 1.609 km
      11.7.2  Site Description


 The site  was  located at the top  of a topographic  divide and the  slopes
 were variable.   In  general, slopes  within the  actual  disposal  area  did
                                   11-53

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not exceed a 25%  grade.   The  usable area, located near the Lorton  prison
complex, was free of trees.
Soils  in  the  area had  a  medium permeability  and  consisted primarily  of
fine sands, silt, clay  and gravel.  The bed rock outcropped frequently  in
the area of the landfill.
A stream bisected the usable area and cut  a  valley with  a 25%  slope.   The
disposal operations  are conducted along the  sides  of the stream  valley.
The groundwater  varied  in  depth  from 40 to 0  (springs)  ft  (12.2 to 0 m)
below the  surface.   Springs and  streams were protected and culverted in
the disposal area.
     •  Topography
        Soil
        Depth to groundwater
        Groundwater use

        Freezing days
        Precipitation (in.)
        Evaporation (in.)
        Surface water
- upland with slopes no greater than
  25%
- sand, silt, and clay
- 0 to 40 ft (12.2 to 0 m)
 - the  aquifer  is not currently used
  as a source of drinking water
- 85 days/yr
- 41 in./yr (104 cm/yr)
- 47 in./yr (120 cm/yr)
- stream roughly bisects site
     11.7.3  Site Selection


The following factors were important in the site selection process:


     •  The land was already owned by Wasington, D.C.

     t  The site size allowed a life of approximately 20 years

     •  The haul route  used  interstate  roads  and other major arteries to
        within a few miles of the facility.


Since the  land  was owned  by Washington, D.C.,  the  3,000 ac  (1,215 ha)
Lorton  site  was  the logical  choice  for  a  landfill.   Consequently, the
selection process consisted largely of evaluating the location.  This was
an  extremely  comprehensive  investigation  and  relevant  impacts  were
thoroughly examined.
Evaluation  of  the facility  showed  that nearly  all  aspects  of  the  site
were conducive to landfill operations.  The factors evaluated included:
                                  11-54

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     •  Topography
     •  Soils
     •  Geology
     •  Surface and groundwater


As a result of the investigation, 800 ac  (324 ha) were made  available  for
"resource recovery, land  reclamation,  an d re reation".   Of this 290  acre
 (117 ha) were allocated for land reclamation via sanitary landfilling.


      11.7.4  Design


 The design criteria  employed  called  for a site life  of  18  years.   Other
 design considerations included:


      •   Adequate Slopes  -  the slopes had to  be  steep  enough to  promote
          drainage but not so steep that erosion would occur.

      •   Screening and  Buffers  -   small  buffers  had  to  be maintained
          between the landfill  and the prison complex and between the  site
          and roads and residences adjacent to  it.

      t   Groundwater  -  as  a   result  of  investigations  conducted  by  a
          consulting  geologist,  it  was  decided  that  2  ft  (0.6   m)  of
          natural   soil   would   provide   a   sufficient   buffer    between
          sludge/refuse deposits  and the  groundwater  table.   The decision
          was based on the attenuative properties on the in  situ soil.

      t   Surface Water  - upland drainage was  diverted  around  the  fill
          area and on-site streams were  protected  by  installing culverts.
          Siltation ponds were  constructed to contain runoff.


 The design identified 20  fill  areas  that were to be  used  successively.
 Clearing and grubbing was performed on  the  areas  only as they were used.
 In general, the excavation was restricted to the amount needed to  provide
 cover for each segment of the  disposal  operation.  Two phases were estab-
 lished, the first to consist  of filling  operations  along  both  sides of
 Mills Branch Creek,  the  second to be done over the creek's stream  valley.
 Figure 11-26 is a map of the usable areas.


 In  assessing   the  amount  of  soil   needed,  the  design  assumed  a  20%
 shrinkage,  and a  final  soil/sludge  refuse mix with a 3:1  ratio.
 The Lorton facility  required both an  interim landfill  operating  permit
 and a full-scale landfill  operating permit.  Accordingly, several  reports
 and design plans  had to  be submitted  to  the Virginia  State  Bureau  of
 Solid Waste.   These included:


                                    11-55

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   FIGURE  11-26
SITE PLAN  LAYOUT
 AT LORTON, VA
                                            SCALE \ = 1000
                                   LEGEND
                               SURFACE WATER COURSES
                               ACCESS ROAD
                           -—PROPERTY BOUNDARY
                           	LIMITS OF LANDFILLING OPERATIONS
                               ACTIVE FILL AREAS
                               WOODED AREAS

                               SITE  MONITORING WELL
                               PROJECT MONITORING WELL
                          o
SITE SURFACE WATER
MONITORING STATION
       11-56

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        A geologic  report
        A design  report
        A site  preparation  plan
        A phased  fill  and covering  plan
        An  operational  procedures  report
     11.7.5  Public  Particiption


          11.7.5.1   Public  Interaction  During  Site  Approval


Considering  the size  of  the  landfill,  the  amount  of  refuse and  sludge
handled, and the fact  that  much of  it  comes  from  outside  the  jurisdiction
of Lorton,  public  reaction  was  mild.   One  explanation  for this was  that
the  public  was  somewhat  more  preoccupied with the  District's  penal  faci-
lity, also  located at  the Lorton  site.


The  greatest concern demonstrated by the public was criticism of  traffic
noise and spilled waste on  Furnace  Road.  There are 5 residences  fronting
this road  on the 3  mi  (4.8 km)  section connecting  1-95  to the  disposal
site.   Noise  level   investigations  were conducted to prove  that  noise
levels were  tolerable, but  public criticism continued until ultimately  a
new  3 mi  (4.8  km)  stretch of road  was  constructed  for the haul  vehicles
parallel to  Furnace  Road.


          11.7.5.2   On-going Public  Relations


Public  criticism of the  landfill  has  been  continuous,   with  most  com-
plaints centering  on  odor  and  spilled  refuse.   On-site operators  have
taken steps to  accommodate  complaints from area residents.


To reduce odors,  operators  cover the sludge  at  the operating face  daily
whenever possible.   When  sludge  is  stockpiled over the weekend,  masking
agents  are   used.    Complaints  concerning  spilled  refuse  are   handled
immediately  by  on-site crew men.   Upon  receiving  a complaint  a  crew  is
dispatched to handle it.  It is hoped that this cooperative approach  will
help to. develop a sense of goodwill  between  the area  residents  and the
landfill operation.


     11.7.6  Operation
The site  operates  5 days a week  from  5 a.m.  to  8 p.m.   Following is  a
discussion of the site preparation, hauling, and disposal  procedures.
                                   11-57

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     •  Sludge to groundwater      - 2 ft  (0.6 m)
     •  Soil cover thickness       - 0.5 to 2 ft  (0.2 to 0.6  m)
     •  Sludge exposure            - <1 day
     •  Total soil usage
        (waste:soil)               - 1:0.33
          11.7.6.1  Site Preparation
Since  the  landfill  occupies  the  top of  a topographic  divide no  upland
drainage flows  into  the site.  All  springs and streams  on  the site  are
protected by culverts and runoff  is  collected  in on-site  basins.


The entire  area was  surrounded  by  a  chain link  fence,  electricity  was
provided for lights on the access  roads and operating  face;  sewer  hookups
were provided for the weigh station  and office.


          11.7.6.2  Sludge Transport


The sludge was  hauled on  interstate 1-95  to within 3  mi  (4.8 km)   of  the
disposal site.   The  road was  designed  to handle  heavy  trucks and  could
easily  accommodate  the impact  of increased traffic.   A separate  access
road was  constructed  to handle  traffic  from 1-95  to  the  site.    The
distance from the various treatment plants are summarized in  Table 11-9.
All roads  on-site  were paved  with  asphalt and approached  within   1/4  mi
(0.4 km) of the operating face.


          11.7.6.4  Operational Procedures


Approximately a year  before a  fill  area is  to  be used  it  is  excavated  and
grubbed.  The operation  is  basically an  area  fill  and occurs  on  slopes.
Successive  sludge/refuse  mixtures  are  layered on the  face  of the  slope
and covered  with an  interim  soil  cover.   Figures  11-27  through  11-30
illustrate the  operational procedures described below.


The process  starts  with  refuse being  dumped  at  the  toe of  a lift  and
worked  uphill.  Sludge  is  then dumped on top  of  the  slope and is  worked
downhill.  The  two  are  then  thoroughly  mixed   (see Figure 11-31).   Before
closing down for the  day  6 in. (15.2 cm)  of soil  is  applied.   An  interim
cover  of 12 in. (30.4 cm)  of soil  is placed when  the lift  is  completed.
At the  conclusion of  phase I  filling operations a final  24 in. (60.9  cm)
soil cover will  be applied.


Originally  sludge  was  not  disposed of  on the  operating face,  but  was
disced  into the soil  in  order to  enrich the relatively infertile  in situ


                                  11-58

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        FIGURE 11-27

SPREADING SLUDGE OVER REFUSE
          LORTON, VA
                    i
        FIGURE 11-28

   SLUDGE AT WORKING FACE
        LORTON, VA
              11-59

-------
          FIGURE 11-29

COVERING SLUDGE/REFUSE MIXTURE
          LORTON, VA
        FIGURE H-30

        GRADED SITE
        LORTON, VA
             11-60

-------
ro
UJ
     D-  «

     O Z
        O
CJ3   O
>—i   Q.
     O
     o
     o
                                         11-61

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soil.   However, this  practice is  not used  as frequently  since frozen
ground  and/or unsuitable  topography  often  prevent  discing  operations.
Additional operational features are presented below.


The equipment used in the operation is as follows:


        	Equipment Type	          No.

        Landfill Compactor                      1
        Tracked Bulldozer                       5
        Scrapers                                3
        Rubber-tired Front End Loaders          2
        Grader                                  1
        Miscellaneous                           5
                TOTAL                          17
Personnel requirements are as follows:
     Quantity      	Job Title	

        8         Supervisor
        13        Equipment & Truck Operators
        18        Laborers
        4         Weigh Station Operators
        4         Other
        47                  TOTAL


     11.7.7  Monitoring


Monitoring of both  surface  and  groundwater is being conducted at 2 month
intervals.  Table 11-10 indicates the monitoring parameters used.  Figure
11-26 shows the location of gauging stations  and test wells.


Surface water  monitoring has  not  detected  any  additional  contamination
from the  landfill.   Readings  from  the  upstream  and downstream stations
have been consistent.  On the other hand,  groundwater monitoring revealed
that detectable  but small  amounts of contaminants  are  leaching from the
fill.   Lead  and  iron  are  the  main  contaminants  monitored  in  the wells
down gradient.  Three  types of  wells  are used to monitor groundwater and
gas simultaneously.
                                   11-62

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                                  TABLE   11-10

                SAMPLING  AND ANALYTICAL PROGRAM  AT LORTON,  VA
                                                           Analyses__	
 Monitoring    Well/Station     Sample Collection    -----   -         TotaTTimes
   Type	  No.            Technique           Parameter (s) _    	to Date	F requency
 Groundwater     BG        PVC bail sampler      Cd, Cr, Cu, Fe, Hg, Ni,       9       every 2 ir.onths
            US-1                         Pb, Zn, Cl , S04, TOC
 Leachate       IR
 Gas          IR         glass burettes       CH^ , COj, N;>, Oj            2       every 6 months
 Surface       UC-1        glass bail sampler     Total solids, DO, BOD,      150       2 times per nc-th
 Water       DC-3                        Cl ,  Hardness, Fecal
                                       coliform
 Groundwater    OW-1
      11.7.8  Completed Site
As  areas are  completed  they will  be  maintained  as open  space.   The  com-
pleted  landfill  will  be integrated  into  the  surrounding  park  land  and
used  for recreation.
According to  site operators, there has  been no  appreciable  subsidence to
date.   However, erosion has  been  a problem and  completed  areas  are  re-
graded  and  seeded as  needed.    The current  slopes  are approximately  25%
and  it  is anticipated that  after Phase II is completed the  gentler  slopes
will  alleviate  the problem  of  erosion.
                        *

      11.7.9  Costs
Hauling costs  are  absorbed  by the  municipalities contributing  sludge  to
the  site.  The  units are  in  dollars  per wet ton  of total  solid waste.   As
shown,  total site cost is  $4.98 per wet ton  of total  solid  waste.  Total
site  cost per dry ton of  sludge  is  $22.64.   Other  expenses  are presented
below.


Capital  and operating costs, and total  costs are  presented  below:
                           " •        11-63

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                                             Total Cost
                                                 (V)

                Site Capital  Costs -(through FY 1978)

                   Planning  and Design           $   190,931        $0.06
                   Road Construction              1,887,495        0.61
                   Clearing  and Grubbing             92,572        0.03
                   Excavations & Stockpiles        1,169,278        0.38
                   Truck Weigh Station              684,455        0.21
                   Equipment                     440,446        0.14
                   Erosion Control 4 Regrad.          118,141        0.04
                   Miscellaneous	      237,271        0.08

                   Total Capital Cost To Date      $ 4,820,589        $1.55

                Site Operating Costs (for FY 1978)

                   Personnel             '      $   826,992        $1.61
                   Equipment Rental                 614,488        1.20
                   Equipment Purchase                 8,000        0.02
                   Equip. Fuel, Parts, Tires           44,000        0.08
                   Supplies  and Materials            176,000        0.34
                   Utilities                      35,600        0.07
                   Water Testing                   10,000        0.02
                   Miscellaneous	       47,000        0.09

                   Total Site Operating Cost      $ 1,762,080        $3.43

                Total Cost (less hauling)               —        $4.98
The unit cost for capital  expenditures was determined  by establishing the
total  costs  to  date and dividing  it  by the  total  waste  received  to  date
(3,110,000 wet  tons (2,820,000  Mg)).   Similarly, the  operating  costs for
FY78  were  derived  by  estimating  the  annual  operating  expenditures  and
dividing these  costs  by  the  amount  of waste  anticipated (513,720 wet  tons
(466,000   Mg)).     Operating   costs   for  FY77,   for   comparison,   were
$1,508,118.83  and  the  total  tonnage  received  was  528,207  (480,000  Mg);
resulting  in a  unit  cost of  $2.86.
                                            11-64                *U"S GOVERNMENTPI"NTINGOfFICE 1978—760-2V6/1

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