oEPA
        United States
        Environmental Protection
        Agency
         Industrial Environmental Research
         Laboratory
         Research Triangle Park NC 27711
EPA-600/7-80-012e
March 1980
Waste and Water
Management for
Conventional Coal
Combustion: Assessment
Report - 1979
Volume V.
Disposal of FGC Wastes

Interagency
Energy/Environment
R&D Program Report

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                  RESEARCH REPORTING  SERIES


Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was  consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:

    1. Environmental Health Effects Research

    2. Environmental Protection Technology

    3. Ecological Research

    4. Environmental Monitoring

    5. Socioeconomic Environmental Studies

    6. Scientific and Technical Assessment Reports (STAR)

    7. Interagency Energy-Environment Research and Development

    8. "Special" Reports

    9. Miscellaneous Reports

This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports m this series result from the
effort funded  under the  17-agency  Federal  Energy/Environment Research and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the  rapid development  of domestic
energy  supplies in an environmentally-compatible manner by providing the nec-
essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants  and their health and ecological
effects; assessments  of,  and development of, control technologies for  energy
systems; and integrated assessments of a wide'range of energy-related environ-
mental  issues.
                        EPA REVIEW NOTICE
This report has been reviewed by the participating Federal Agencies, and approved
for  publication. Approval does not signify that the contents necessarily reflect
the  views and policies of the Government, nor does mention of trade names or
commercial products constitute endorsement or recommendation  for use.

This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                 EPA-600/7-80-012e

                                         March 1980
   Waste  and Water  Management
for Conventional Coal  Combustion
     Assessment Report - 1979
Volume V. Disposal  of  FGC Wastes
                        by

             CJ. Santhanam, R.R. Lunt, C.B. Cooper,
          D.E. Klimschmidt, I. Bodek, and W.A. Tucker (ADL);
             and C.R. Ullrich (University of Louisville)

                   Arthur D. Little, Inc.
                     20 Acorn Park
               Cambridge, Massachusetts 02140
                 Contract No. 68-02-2654
                Program Element No. EHE624A
              EPA Project Officer: Julian W. Jones

            Industrial Environmental Research Laboratory
          Office of Environmental Engineering and Technology
               Research Triangle Park, NC 27711
                     Prepared for

            U.S. ENVIRONMENTAL PROTECTION AGENCY
              Office of Research and Development
                  Washington, DC 20460

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                       PARTICIPANTS IN THIS  STUDY


     This First Annual R&D Report is submitted by Arthur D.  Little,  Inc.

to the U. S. Environmental Protection Agency (EPA) under Contract No.

68-02-2654.  The Report reflects the work of many members of the

Arthur D. Little staff, subcontractors and consultants.   Those partici-

pating in the study are listed below.

Principal Investigators

     Chakra J.  Santhanam
     Richard R. Lunt
     Charles B. Cooper
     David E. Kleinschmidt
     Itamar Bodek
     William A. Tucker

Contributing Staff

     Armand A.  Balasco                        Warren J.  Lyman
     James D. Birkett                         Shashank S. Nadgauda
     Sara E. Bysshe                           James E. Oberholtzer
     Diane E. Gilbert                         James I. Stevens
     Sandra L.  Johnson                        James R. Valentine

Subcontractors
     D. Joseph Hagerty                        University of Louisville
     C. Robert Ullrich                        University of Louisville

     We would like to note the helpful views offered by and discussions

with Michael Osborne of EPA-IERL in Research Triangle Park, N. C. , and

John Lum of EPA-Effluent Guidelines Division in Washington, D. C.

     Above all, we thank Julian W. Jones, the EPA Project Officer, for

his guidance throughout the course of this work and in the preparation

of this report.
                                    ii

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                            ACKNOWLEDGEMENTS

     Many other individuals and organizations helped by discussions with
the principal investigators.  In particular, grateful appreciation is
expressed to:
     Aerospace Corporation - Paul Leo, Jero*ne Rossoff
     Auburn University - Ray Tarrer and others
     Department of Energy - Val E. Weaver
     Dravo Corporation - Carl Gilbert, Carl Labovitz, Earl Rothfuss
          and others
     Electric Power Research Institute (EPRI) - John Maulbetsch,
          Thomas Moraski and Dean Golden
     Environmental Protection Agency,  Municipal Environmental Research
          Laboratory - Robert Landreth, Michael Roulier, and Don Banning
     Federal Highway Authority - W.  Clayton Onnsby
     IU Conversion Systems (IUCS)  - Ron Bacskai, Hugh Mullen
          Beverly Roberts, and others
     Louisville Gas and Electric Company - Robert P.  Van Ness
     National Ash Association - John Faber
     National Bureau of Standards  - Paul Brown
     Southern Services - Reed Edwards, Lament Larrimore, and Randall Rush
     Tennessee Valley Authority (TVA)  - James Crowe,  T-Y.  J.  Chu,
          H.  William Elder, Hollis B.  Flora, R. James Ruane,
          Steven K. Seale, and others
                                  iii

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                            CONVERSION FACTORS
     English/American Units
Length:
     1 inch
     1 foot
     1 fathom
     1 mile (statute) :
     1 mile (nautical)
Area:
     1 square foot
     1 acre
Volume:
     1 cubic foot
     1 cubic yard
     1 gallon
     1 barrel (42 gals)
Weight/Mass:
     1 pound
     1 ton  (short)
Pressure:
     1 atmosphere (Normal)
     1 pound per square inch
     1 pound per square inch
Concentration:
     1 part per million (weight)
Speed:
     1 knot
Energy/Power:
     1 British Thermal Unit
     1 megawatt
     1 kilowatt hour
Temperature:
     1 degree Fahrenheit
     Metric  Equivalent

  2.540  centimeters
              •
  0.3048 meters
  1.829  meters
  1.609  kilometers
  1.852  kilometers

  0.0929 square  meters
  4,047  square meters

 28.316  liters
  0.7641 cubic meters
  3.785  liters
  0.1589 cu.  meters

  0.4536 kilograms
  0.9072 metric  tons

101,325  pascal
  0.07031 kilograms per square centimeter
    6894 pascal

  1 milligram per liter

  1.853 kilometers per hour
  1,054.8 joules
  3.600 x 109 joules per hour
  3.60 x 106 joules
  5/9 degree Centigrade

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                           GLOSSARY
Cement!tious:  A chemically precipitated binding of particles
resulting in the formation of a solid mass.

Fixation:  The process of putting into a stable or unalterable
form.

Impoundment:  Reservoir, pond, or area used to retain, confine,
or accumulate a fluid material.

Leachate:  Soluble constituents removed from a substance by the
action of a percolating liquid.

Leaching Agent;  A material used to percolate through something
that results in the leaching of soluble constituents.

Pozzolan;  A siliceous or aluminosiliceous material that in
itself possess little or no cementitious value but that in
finely divided form and in the presence of moisture will react
with alkali or alkaline earth hydroxide to form compounds possessing
cementitious properties.

Pozzolanic Reaction;   A reaction producing a pozzolanic product.

Stabilization:   Making stable by physical or chemical treatment.

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                   ABBREVIATIONS
BOD
Btu
cc
cm
COD
°C
°F
ESP
FGC
FGD
ft
g
gal
 gpm
 hp
 hr
 in.
 j
 j/s
 k
 kg
 kCal
 km
 kw
 kwh
 £ or lit
 Ib
 M
mg
MGD
MW
MWe
MWH
Hg
mil
min
ppm
psi
psia
scf/m
sec
IDS
TOS
TSS
tpy
yr
biochemical oxygen  demand
British  thermal unit
cubic  centimeter
centimeter
chemical  oxygen demand
degrees  Centigrade  (Celcius)
degrees  Fahrenheit
electrostatic precipitator
flue gas  cleaning
flue gas  desulfurization
feet
gram
gallon
gallons  per day
gallons  per minute
horsepower
hour
inch
joule
joule  per second
thousand
kilogram
kilocalorie
kilometer
kilowatt
kilowatthour
liter
pound
million
square meter
cubic meter
milligram
million gallons per day
megawatt
megawatt  electric
megawatt  hour
microgram
milliliter
minute
parts per million
pounds per square inch
pounds per square inch absolute
standard cubic feet per minute
second
total dissolved solids
total oxidizable sulfur
total suspended solids
tons per year
year
                       vi

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                          TABLE OF CONTENTS
                                                              Page
ACKNOWLEDGEMENTS                                                ill
CONVERSION FACTORS                                               iv
GLOSSARY                                                          v
ABBREVIATIONS                                                    vi
LIST OF TABLES
                                                                 X.J_
LIST OF FIGURES                                                xiii
 1.0  INTRODUCTION                                              1-1
      1.1   Purpose and  Content                                   1-1
      1.2   Report  Organization                                   1-4
 2.0  DISPOSAL OF  FGC WASTES                                     2-1
      2.1   Disposal Options                                      2-1
           2.1.1   Overview on Technology  & Waste Properties      2-1
           2.1.2   Matrix  of Disposal  Options                     2-9
           2.1.3   Current Disposal Practices                     2-9
           2.1.4   Current Field  Studies                          2-20
      2.2   Disposal on  Land                                      2-23
           2.2.1   Wet Ponding                                    2-24
           2.2.2   Dry Disposal Methods                           2-41
           2.2.3   Surface Mine Disposal                          2-59
           2.2.4   Underground Mine Disposal                      2-66
      2.3   Disposal in  the Ocean                                2-72
           2.3.1   Overview                                      2-72
           2.3.2   Disposal Technology                           2-73
           2.3.3   Current Studies                                2-76
      2.4   Disposal Options vs Potential  Impact  Issues           2-78
           2.4.1   Overview on Impact  Issues                      2-78
           2.4.2   Mechanism of Impact                           2-82
           2.4.3   Issue Definition Process                       2-99
      2.5   Site Selection, Design and Practice of  FGC           2-103
           Waste Disposal
           2.5.1   Land  Disposal                                  2-103
           2.5.2   Ocean Disposal                                2-113
 3.0  REGULATORY CONSIDERATIONS                                  3-1
      3.1   Regulatory Framework  Overview                         3-1
      3.2   Groundwater  Related                                   3-8
           3.2.1   Resource Conservation & Recovery Act           3-8
           3.2.2   Safe  Drinking  Water Act/Underground
                  Inspection  Control  Program                     3-20
           3.2.3   Surface Mining Control  and Reclamation Act     3-21
           3.2.4   State Regulations                               3-23
                                  vii

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                     VOLUME 5:  TABLE OF CONTENTS
                              (Continued)
                                                               Page
     3.3  Surface Related                                       3-24

          3.3.1  Introduction                                   3-24
          3.3.2  Surface Water Quality Offgas from
                 Point Source Discharges                        3-25

     3.4  State Requirements and Plants                         3-39

          3.4.1  Present Status                                 3-39
          3.4.2  Responses to Proposal Regulations
                 under RCRA                                     3-52

     3.5  Ocean Disposal Related                                3-56

          3.5.1  Statutory Base                                 3-56
          3.5.2  Administration Regulations                     3-58
          3.5.3  Consideration of Alternatives                  3-58
          3.5.4  Prohibited Materials                           3-59
          3.5.5  Other Factors Limiting Permissible
                 Concentrations                                 3-60
          3.5.6  Monitoring Requirements                        3-60

     3.6  Stability Related                                     3-62

          3.6.1  Resource Conservation & Recovery Act of 1976   3-62
          3.6.2  Surface Mining Control & Reclamation
                 Act of 1977                                    3-64
          3.6.3  Federal Coal Mine Health & Safety Act
                 if 1969                                        3-66
          3.6.4  Occupational Safety & Health Act of 1970       3-67
          3.6.5  Dam Inspection Act of 1972                     3-67
     3.7  Land Use Related                                      3-69

          3.7.1  Overview                                       3-69
          3.7.2  RCRA                                           3-69
          3.7.3  Surface Mining Control & Reclamation
                 Act of 1972                                    3-74
          3.7.4  Land Use Consideration Under State
                 Regulations                                    3-81

     3.8  Air Related                                           3-86
     3.9  National Energy Act of 1978                           3-90

4.0  ENVIRONMENTAL IMPACT CONSIDERATION                         4-1

     4.1  Introduction                                          4-1
     4.2  Land Disposal                                         4-2
                              viii

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                           TABLE OF CONTENTS
                              (Continued)
          4.2.1  Physical  Stability  Overview
          4.2.2  Public  Policy and Land Use
          4.2.3  Wet  Ponding
          4.2.4  Dry  Disposal
          4.2.5  Mine Disposal
     4.3  Ocean Disposal                                       4-36

          4.3.1  Overview                                       4-36
          4.3.2  Impact  Assessment                              4-36
     4.4  Assessment  of  Present Control Technology              4-41
          4.4.1  Introduction                                   4-41
          4.4.2  Site Selection                                4-42
          4.4.3  Waste Processing Options                       4-43
          4.4.4  Use  of  Liners                                 4-45
          4.4.5  Codisposal                                    4-45
     4.5  Summary of  Data  Gaps and Future  Research  Needs        4-45
5.0  REVIEW OF MONITORING  CONSIDERATIONS                        5-1
     5.1  Regulatory  Requirements for Disposal                  5-1

          5.1.1  Land Disposal Monitoring                       5-1
          5.1.2  Ocean Disposal Monitoring                     5-3
     5.2  Screening Tests  for  Solid  Wastes                     5-4

          5.2.1  Sample  Pretreatment                           5-5
          5.2.2  Extraction Procedure                          5-5
          5.2.3  Testing of Extracts                           5-6
     5.3  Water Monitoring Methods                              5-7
          5.3.1  Methods for Freshwater                         5-7
          5.3.2  Methods for Ocean Monitoring                  5-8

     5.4  Fugitive Emissions Monitoring                         5-9
     5.5  Biological  Monitoring                                5-9

          5.5.1  Introduction                                   5-9
          5.5.2  Predisposal Baseline Surveys                  5-10
          5.5.3  Predisposal Bioassay Testing                  5-11
          5.5.4  Biological Monitoring for Disposal
                 Operation Compliance                          5-13
     5.6  Monitoring  of  Physical Properties                     5-15
     5.7  Post-operational Monitoring                          5-16
     5.8  Data Gaps and  Future Research Needs                  5-17
                                ix

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                            TABLE OF  CONTENTS
                               (Continued)

                                                                 Page
6.0  REVIEW OF ECONOMICS OF DISPOSAL                             6-1
     6.1  Introduction                                           6-1
     6.2  Generalized Waste Disposal Cost Studies                6-1
          6.2.1  Description of Studies                          6-1
          6.2.2  Disposal Cost Estimates for FGC Wastes          6-9
     6.3  Economic (Cost) Impact Stdies                          6-22
          6.3.1  Radian Study                                    6-22
          6.3.2  SCS Study                                       6-25
     6.4  Economic Uncertainties                                 6-26
     6.5  Data Gaps                                              6-29
REFERENCES

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                            LIST OF TABLES
Table No .                                                      Page

  2.1   Potential Disposal Options                             2-10
  2.2   Fly Ash Collection - Disposal Practices                2-12

  2.3   Fly Ash Disposal Practices by Quantity of Ash          2-13

  2.4   Bottom Ash Collection and Disposal Practices            2-14

  2.5   Bottom Ash Disposal Practices by Quantity of  Ash       2-15

  2.6   Nonrecovery FGC System is Commercial Operation
        on Utility Boilers                                     2-17
  2.7   Nonrecovery FGD Systems in Commercial Operation on
        Industrial Boilers              '                       2-18
  2.8   Summary of Disposal Practices for Operational
        FGC Systems on Utility Boilers as of
        November 1978                                          2-19
  2.9   Summary of Current Field Testing Programs
        for FGC Waste Disposal                                 2-22
  2.10  Summary of Land Disposal of FGC Wastes                 2-24
  2.11  Typical FGC Waste Disposal Operations -
        Wet Disposal                                           2-25
  2.12  Potential FGC Waste Disposal Impact Issues             2-79

  2.13  Disposal Options VS Potential Environmental
        Impact Issues for FGC Wastes                           2-80
  2.14  Relative Potential for Water-Related Impacts
        From Different FGC Waste Disposal Options              2-92

  2.15  Status of Issue Definition by Regulations
        Governing Disposal of FGC Wastes                       2-101
  2.16  FGC Waste Disposal Site Evaluation Parameters          2-105

  3.1   Regulatory Framework for Coal Ash and FGD Sludge
        Disposal/Utilization                                   3-9
  3.2   Effluent Parameters Subject to Effluent Guidelines
        Limitations for the Steam Electric Power Generation
        Category                                               3-26

  3.3   Comparison of FGC Waste Liquors with Water Criteria    3-28
  3.4   Discharge  Criteria in New York and Missouri            3-29

  3.5   Management and Disposal of Solid Wastes In States       3-40
  3.6   PSD Limits on Increases in Pollutant Levels             3-88
                                xi

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                            LIST OF TABLES
                             (Continued)
Table No.                                                      Page
  4.1    Cumulative Land Requirements for Disposal
         of FGC Wastes                                         4-38
  4.2    Observations of Mounds of FGC Wastes Created
         in Shallow Water Environment                          ,  _q
  6.1    Summary of General Conceptualized Cost
         Studies - FGC Wastes                                  6-2
  6.2    Summary of Basic Assumptions for General
         Cost Studies - FGD Wastes                             6-4
  6.3    Summary of TVA Cost  Estimates  for Wet  Ponding          6-11
  6.4    Comparison of  Generalized  Costs  for Wet Ponding
         Unstabilized FGC Wastes                                6-13
  6.5    Summary of TVA Estimates  for Dry Impoundment           6-16
         Disposal Systems
  6.6    Summary of Mine Disposal  of FGC Wastes                 6-19
  6.7    Summary of Preliminary Cost Estimates  for Ocean        6-20
         Disposal of FGC Wastes
  6.8    Summary of Estimated Cost  of Compliance                6-28
  6.9    Summary of Regulatory Impacts  to Consumers             6-27
         in Mills/kWh
                                  xii

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                           LIST  OF FIGURES
Figure No .
   2.1   Waste Handling Colstrip Plant  Montana
         Power Company                                           2-26
   2.2   Handling LaCygne Station,  Kansas  City
         Power & Light Company                                   2-27
   2.3   Waste Handling St.  Clair Plant -  Detroit
         Edison Company                                          2-28
   2.4   Waste Handling Sherburne Plant -
         Northern States Power Company                            2-29
   2.5   Waste Handling - Bruce Mansfield  Plants -
         Pennsylvania Power  Company                              2-30
   2.6   Pond Designs                                            2-34
   2.7   Proposed Gypsum Pond Water Seepage Control
         System Using a Collection  Ditch Around the
         Perimeter (EPA Effluent Guidelines Document)             2-37
   2.8   Typical Landfill Scheme for Sulfate-Rich or
         Gypsum Wastes                                           2-45
   2.9   Untreated Waste Fly Ash Blending                         2-46
   2.10  FGC Waste Disposal  Using a Stabilization Process        2-49
   2.11  Schematic of IUCS "Stabilization" Process at
         Conesville                                              2-51
   2.12  General Landfill Designs                                2-57
   2.13  Area Strip Mining with Concurrent Reclamation           2-61
   2.14  FGC Disposal Site Selection Process Logic Diagram       2-104
   3.1   FGC Wastes - Federal Regulatory Chart                   3-5
   3.2   Regulatory Requirements - RCRA                          3-14
   4.1   Oxygen Depletion Rates in Well-Agitated Slurries
         of FGC Wastes                                           4-38
   4.2   Observations of Mound of FGC Wastes Created
         in Shallow Water Environment                            3-39
                                 xiii

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1.0  INTRODUCTION
1.1  Purpose and Content

     As coal utilization in utilities and large industrial boilers
increases, the quantity of flue gas cleaning (FGC) wastes, particularly
those associated with flue gas desulfurization (FGD), will increase dramati-
cally.  The preponderant part of these FGC wastes will be sent for disposal.
Over the long term, utilization is expected to grow but at a slower rate
than that of FGC waste generation.  Projections of coal ash and FGD
wastes through 2000 were provided in Volume 3.
     In the past, utilities operating FGC systems have typically disposed
of wastes by storage in ponds, often without provision for control of over-
flows or seepage into groundwater.  However, several factors will dra-
matically influence disposal options in the coming years.
     a.  An increase in coal-fired capacity in the United States.
         In 1976 the total U.S. coal-fired electric utility generating
         capacity was estimated at over 191,000 MW in 399 plants  [1].
         The estimated capacity is expected to increase by 1986 to over
         326,000 MW  [2].  Use of coal in large industrial boilers  (+25 MW
         equivalent or larger) is likely to further increase the  total
         coal-fired capacity [3,4].
     b.  A major increase in the application of scrubber  technology
         by utilities and a consequent increase in FGD waste genera-
         tion.  At present,over 16,000 MW of generating capacity  at
         some thirty plants utilize FGD systems.  As of September
         1978, over 59,000 MW of capacity have been committed[5].
         Future increases are likely to be even more dramatic.
     c.  Advances in stabilization technology for FGD wastes which
         permit landfill disposal of partially dewatered  solids
         instead of ponding of difficult to handle sludges.  In the
         future, disposal of wastes in managed fills is likely to
         be encouraged.  In many cases this will  require  stabilization
         prior  to disposal.
                                      1-1

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     d.  Regulatory developments including the Clean Air Act of 1977
         and the Resource Conversation & Recovery Act of 1976 (RCRA).
         The recent issuance of proposed guidelines provides impetus to
         environmentally sound disposal of FGC wastes [6].   New Source
         Performance Standards (NSPS) for criteria pollutants are now
         under review by the EPA and may be significantly tightened.
Thus, disposal of FGC wastes will require major and continuing focus on
potential environmental impacts.
     This is the fifth in a five-volume report assessing technology
for the control of waste and water pollution from combustion sources.
This volume reports on the status of FGC waste disposal including both
current commercial practice and ongoing R&D programs.  The focus of this
volume includes the technical, economic,  regulatory and environmental
aspects of ongoing technology development and commercialization of FGC
waste disposal.  FGC wastes considered in this report include FGD wastes
primarily from non-recovery systems.
     The primary focus of this report is on coal-fired power plants;
however, many of the characteristics discussed would also apply to wastes
from oil-fired boilers.  Coal-fired power plants generate the maximum
range of waste types and usually the greatest quantity.  Thus, they can
serve as the logical focus for assessing environmental and technological
problems relating to the disposal and utilization of waste materials.
     A coal-fired power plant produces two broad categories of coal-
related wastes:
     •  Coal ash, which includes both fly ash and bottom ash (or boiler
        slag),  and
     •  Flue gas desulfurization (FGD) wastes from the control of sulfur
        dioxide emissions.
Together, fly ash and FGD wastes are generally referred to as flue gas
cleaning (FGC)  wastes.  In many cases, fly ash and S0~ emissions are
separately controlled and represent separate waste streams.  In other
cases, fly ash and FGD wastes are combined in a single stream, either

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through admixture of these wastes or through simultaneous collection of
fly ash and SO--  This review of FGC waste includes coal ash,  FGD wastes,
and their combination both as produced directly from FGC systems as well
as wastes processed for disposal.
     The review and assessment has involved two separate efforts as
described below:
     1.  Review of the data and information available as of February 1979
         on the disposal of FGC wastes.  The review is based upon
         published reports and documents as well as contacts with private
         companies and other organizations engaged in FGC technology
         development or involved in the design and operation of FGC
         systems and waste disposal facilities.  Much of the information
         has been drawn from the waste disposal and characterization
         studies and technology development/demonstration programs
         sponsored by the Environmental Protection Agency (EPA) and
         the Electric Power Research Institute (EPRI).
     2.  Based upon the review of the data and assessment of ongoing
         work in waste disposal, identification of data and
         information gaps relating to waste properties and the develop-
         ment of recommendations for potential EPA initiatives to assist
         in covering these gaps.  The principal purpose of this effort
         is to ensure that, ultimately, adequate data will be available
         to permit reasonable assessment of the impacts associated with
         the disposal and/or utilization of FGC wastes.
Throughout this work, emphasis has been placed upon wastes produced by
commercially demonstrated technologies and, where data are available, by
technologies in advanced stages of development that are likely to achieve
commercialization in the United States in the near future.  In terms of
FGD wastes, consideration is limited to non-recovery  FGD systems with
focus  on those producing solid wastes  (rather  than liquid wastes).  There
are very few recovery systems in operation or under construction  in the
United States, and these generally produce a small quantity of waste in
comparison to non-recovery systems.
                                   1-3

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1.2  Report Organization
     Complete assessment of FGC waste disposal is site- and system-specific.
With that understanding, this volume presents a broad overview on the
following subjects to provide a generic baseline for environmental
assessment:
     •  Description of disposal options studied or practiced today,
     •  Definition of potential impact issues,
     •  Assessment of environmental impacts,
     •  Review of monitoring considerations, and
     •  Review of FGC waste disposal economics.
                                  1-4

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2.0  DISPOSAL OF FGC WASTES
2.1  Disposal Options
2.1.1  Overview on FGC Technology and Waste Properties
     Coal-fired industrial and utility boilers generate two types of
combustion-related wastes:
     •  Coal ash, including fly ash and bottom ash
        (or boiler slag), and
     •  FGD wastes from the control of SC^ emissions.
     The technology of ash collection and flue gas desulfurization (FGD),
the characteristics of the wastes produced, and projections on waste
generation were discussed in Volume 3.  This chapter provides a review
of disposal options both current and potential.  Emphasis is placed on
fly ash and nonrecovery FGD process wastes since these will be the
principal products in the next few years.
     Detailed physical and chemical characterization of FGC wastes is
provided in Volume 3.  Some aspects of FGC wastes will be considered
here to place disposal options in perspective.
2.1.1.1  Coal Ash
     The total amount of coal ash produced is a function of the ash
content of the coal.  The partitioning of coal ash between fly ash and
bottom ash (or boiler slag) is dependent on the type of boiler and its
general operating condition.  Standard pulverized-coal-fired boilers
typically produce about 80-90% of the ash as fly ash.  In cyclone-fired
boilers, frequently used to burn lignite, the fly ash fraction is usually
less; in some cases, bottom ash constitutes the majority of the total
ash generated.
     Collection of bottom ash  (or boiler slag) does not involve systems
outside the boiler itself.  The key technology issue is the handling of
bottom ash.  Fly ash, however, is a major source of particulate emissions
and, with regulatory requirements, has required major collection  systems.
Control of particulate emissions from pulverized-coal-fired steam gener-
ators is rapidly becoming a significant  factor in the siting and  public
                                   2-1

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acceptability of coal-burning power plants.  The particulate emissions
limit under current NSPS set by the EPA for large, new coal-fired boilers
is 0.043 grams/106 joules (0.1 lb/106 Btu).  Some states have requirements
more restrictive than this.  Furthermore,  the NSPS are now under review
and are expected to be tightened significantly.  Tightening regulatory
posture indicates the following:
     •  For reliable service in new large  systems, fly ash will be
        collected separately from wet scrubbing-based FGD systems.
        In the past, simultaneous collection of both fly ash and
        SOX has been practiced.  If dry sorbent FGD systems are
        used, simultaneous collection will be practiced.
     •  Fly ash collection will be based primarily on electrostatic
        precipitators (ESP's) or fabric filters.  Mechanical collection
        may be employed only to supplement the above two types of
        particulate collectors.
     The chemical composition of coal ash  (bottom ash, fly ash, and slag)
varies widely in concentrations of both major and minor constituents.  The
principal factor affecting the variation in the composition is the vari-
ability in the mineralogy of the coal.  However, differences in composi-
tion can exist between fly ash and bottom ash (or boiler slag) generated
from the same coal because of differences in the degree of pulverization of
the coal prior to firing, the type of boiler in which the coal is fired,
and the boiler operating parameters and combustion efficiency.  Regard-
less of the type of ash (either fly ash or bottom ash), more than 80% of
the total weight of the ash is usually made up of silica, alumina, iron
oxide, and calcium oxide.  It should be noted that the compositional
breakdown usually shown in the literature  (including Volume 3) reflects
only the elemental breakdown of the constituents reported as their oxides
and not necessarily the actual compounds present.
     While the major constituents of bottom ash and fly ash are generally
similar, there is usually an enrichment of trace elements in the fly ash
as compared with the bottom ash based upon the total quantity of trace
elements in the coal fired.   A few of the elements originally present in
                                  2-2

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the coal (notably sulfur, mercury, and chlorine) are almost completely
volatilized and leave the boiler as gaseous species which are not col-
lected downstream in dry ash collection equipment.  However, these can
be collected in wet scrubber systems.
     Up to 10% of fly ash can be water-soluble, so the potential exists
for release of contaminants through leaching.  The principal soluble
species are usually calcium, magnesium, sodium, potassium, sulfate, and
chloride.  Leachates resulting from ash are usually alkaline due to the
presence of calcium oxide and other alkaline species, although some ashes
have been found to be inherently neutral or even acidic.
     The physical properties of fly ash vary with the type of coal fired,
the boiler operating conditions, and the type of fly ash collector employed.
A mechanical collector, which generally removes only the heaviest fly ash
fraction, produces a relatively coarse material with the consistency of a
fine sand.  In contrast, the ash removed in an electrostatic precipitator
is usually finer, with a silt-like grading.  The range of  specific gravi-
ties of fly ash depends upon particle size distribution and fly  ash com-
position; however, specific gravities typically range from approximately
1.9 to 2.7.  Usually a small portion of the fly ash consists of  cenospheres
(hollow spheres) which have an apparent density less than  water.  Bulk
densities of fly ash, because of the variations in specific gravity and
particle size distribution, vary greatly; although, a typical range for
                                                             3
fly ash compacted at optimum dry density would be 1.1-1.79/cm   (70-105
lb/ft3).
     An important property of coal fly ash is  its pozzolanic activity.
Pozzolanic activity refers to the ability of fly ash to aggregate and
harden when moistened and compacted  due to reactions with  lime  either
present in the ash or admixed with the ash.  Because the degree  of
pozzolanic activity can vary greatly, there can be considerable  variation
in the engineering and structural properties of fly ash.   Ashes  from most
lignite and some subbituminous coals, for example, have relatively high
calcium levels  (>10% measured as calcium oxide) and, as such, usually
exhibit significant self-hardening properties.  However,  in  general,
                                   2-3

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unstabilized fly ash (that to which lime has not been added intentionally)
usually exhibits engineering properties similar to soils of equivalent
particle size distributions.  Permeabilities of compacted fly ash samples
generally range from 5 x 10~^ cm/sec to 5 x 10~5 cm/sec.  (See Volume 3,
Reference 70,82,83.) Stabilization of pozzolanic fly ashes with lime can
result in significant increases in compressive strength and decreases in
permeability (depending upon the amount of lime, the water content, curing
time, and degree of compaction).
     Bottom ash can be collected either dry or in a molten state, in
which case it is generally referred to as boiler slag.  Dry-collected
bottom ash is heavier than fly ash, with a larger particle size distribu-
tion.  Since it has a similar chemical composition to that of fly ash,
it behaves similarly, although pozzolanic activity is usually somewhat
less in bottom ash.
     Boiler slag is a black, glassy substance created by water quenching
of the molten ash.  It is composed chiefly of angular or rod-like particles,
with a particle size distribution ranging from fine gravel to sand.  Boiler
slag is porous, although not of so great a porosity as dry bottom ash.  It
is generally less reactive in terms of its pozzolanic properties than either
dry bottom ash or fly ash.  Because of the similarities between bottom and
fly ashes, they are generally grouped together for environmental impact
assessments.
2.1.1.2  FGD Wastes
     FGD systems are generally categorized into two groups:
     •  Nonrecovery or throwaway systems which produce a solid or
        liquid waste with little market value at present, and
     •  Recovery systems that produce elemental sulfur or sulfuric
        acid as a byproduct for sale.
At present, the overwhelming majority of FGD systems for controlling
emissions from industrial and utility boilers utilize some form of non-
recovery system.  Over 90% of the 59,000 MW committed to FGD systems
involve nonrecovery processes [5].  This dominance of nonrecovery pro-
cesses is expected to continue over the next ten years.
                                 2-4

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     Commercially available nonrecovery processes can be conveniently
subdivided into two groups according to the form of the waste materials
produced—those which convert the 862 into a solid waste and those which
produce a liquid waste.  Nonrecovery systems can also be classified
according to the manner in which the flue gas is contacted with the
S02 sorbent—i.e., wet scrubbing processes versus dry processes.
     All nonrecovery systems now in commercial operation on utility and
industrial boilers are wet processes involving contact of the gases with
aqueous slurries or solutions of absorbents.  Although most nonrecovery
systems can withstand relatively high levels of particulate and trace
contaminants and many in the past have been designed for simultaneous
S02 and particulate control, most systems being installed today on utility
boilers are downstream from high efficiency electrostatic precipitators
in order to ensure more reliable service.  The notable exceptions are
systems designed to utilize alkalinity in the fly ash for all or part
of the SC>2 removal.  These frequently incorporate simultaneous  fly ash
and S02 control.
     Dry processes have not yet been demonstrated commercially  on a
utility scale in the United States.  However, a number of different
approaches have been investigated, including dry injection of sorbents
into the boiler and flue gas and the use of spray dryers.  All  of these
involve simultaneous 862 and particulate control, and all produce a dry
waste material.  The most promising approach at present employs spray
dryers for contacting the flue gas with slurries (or solutions) of
calcium hydroxide or sodium carbonate/bicarbonate.  Three such  systems
have been contracted for application to utility-scale boilers.
Solid Wastes
     The  four basic types of nonrecovery systems producing solid wastes
are:
     •  Direct  lime scrubbing,
     •  Direct  limestone scrubbing,
     •  Alkaline  fly ash scrubbing,  and
     •  Double  (dual)  alkali.
                                 2-5

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     The first three of these utilize slurries of lime, limestone, or
ash to contact the flue gases and produce slurries containing 5-20 wt%
solids which are either discharged directly or partially dewatered and
possibly further processed prior to discharge.  All three of these are
commercially demonstrated technologies.  The fourth, the double alkali
process, is a second generation technology which has been applied success-
fully to industrial-scale boilers but is only now reaching commercial
demonstration on utility boilers.  Double alkali processes utilize
solutions of sodium salts for SOo removal, which are then regenerated
using lime to produce a waste solid that is discharged as a filter cake.
     In addition, dry sorbent based FGD systems are also likely to be
in commercial use by the early 1980's.  These will be based on lime,
sodium salts or other sorbent and will produce dry solid wastes.  To
date, the extent of focus on utilization of such dry sorbent wastes
has been minimal.
     The quantity and composition of ash-free FGD wastes are dependent
upon a number of factors including:  coal characteristics (most impor-
tantly, its sulfur content and heating value); SO™ emissions regulations;
the type of boiler and its operating conditions; and the type of FGD
system and its operating conditions.  In general, the quantity of dry,
ash-free FGD waste produced varies from about 2.0 to about 3.5 times the
quantity of S02 removed from the flue gas.  Hence, a typical utility
boiler operating at a 70% load factor could produce anywhere from 50 to
500 tons of dry, ash-free solids annually per megawatt of boiler capacity.
     The principal substances making up the solid phase of FGD wastes are
calcium-sulfur salts (ralciuii. sulfite and/or calcium sulfate) along with
varying amounts of calcium carbonate, unreacted lime, inerts and/or fly
ash.  In wet processes the ratio of calcium sulfite to calcium sulfate
is a key design and operating parameter, especially for direct scrubbing
systems since it can affect not only the scale potential of the system
but also the waste solids properties.  The relative amounts of calcium
sulfite and sulfate present depend principally upon the extent to which
oxidation occurs within the system.  Oxi '.ation is generally highest in
                                 2-6

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systems installed on boilers burning low sulfur coal or in systems where
oxidation is intentionally promoted.  In most medium to high sulfur coal
applications, oxidation of sulfite to sulfate in the scrubber system
amounts to only 10-30%, and calcium sulfite is the predominant material
in the waste.  When the sulfate content of the waste solids is low,
calcium sulfate usually is present as the hemihydrate salt (CaSO,  •
1/2H20).   At higher calcium sulfate levels, gypsum (CaSO,  • 2H 0)
becomes the predominant form of calcium sulfate.   At very high levels
of oxidation (greater than 90% oxidation of the SO,, removed) all of the
calcium sulfate will usually be present as gypsum.
     Because the differences in the crystalline morphology of hemihydrate
and dihydrate solids not only reflect the chemical composition but also
can affect the physical and engineering properties, it is convenient to
classify FGC wastes on the basis of the ratio of calcium sulfate to
total calcium-sulfur salts.  The three categories are as follows:
     •  Sulfate rich (CaSO./CaSO  > 0.90),
                          4     X
     •  Mixed (0.25 < CaSO./CaSO  < 0.90), and
                          T1     X
     •  Sulfite rich (CaSO,/CaSO  < 0.25),
                          4     X
where CaSO  is the total calcium-sulfur salts.
          X
     Calcium sulfite wastes present a problem because of the difficulty
of dewatering.   The slurry can be dewatered only to about 50-60% solids,
producing an unstable, thixotropic material.  However, calcium sulfite
wastes can be oxidized to calcium sulfate, either intentionally in the
scrubber or in an external oxidation reactor.  From the viewpoint  of
utilization, calcium sulfate is the desirable FGD byproduct.
     EPA studies at the Industrial Environmental Research Laboratory
(Research Triangle Park, North Carolina) have shown that calcium sulfite
can be readily oxidized to gypsum by simple air/slurry contact in  the hold
tank of the  scrubber recirculation loop.   Although  the rate of oxidation
reaches a maximum at a pH of 4.5 and then  declines  at higher  pH, it was
found that oxidation could be accomplished at a practical  rate up  to a pH
of about 6.0  [38].
                                 2-7

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     In Japan, where natural gypsum is not available, forced oxidation
in scrubber systems has been employed extensively to produce a high-
quality gypsum raw material for the cement and wallboard industries.
In the United States, scrubber gypsum may be unable to compete exten-
sively with the widely available natural gypsum.  Thus, the incentive
in the United States has been to develop simplified forced oxidation
procedures directed only toward improving waste solids handling and
disposal properties.  As a disposal material, the gypsum waste can
have high fly ash content; moreover, the oxidation reaction need be
carried only to about 95% completion.
     There is little information currently available on the composition
of wastes from dry scrubbing systems utilizing spray dryers.  However,
while all of these would contain fly ash, the fraction of the waste
resulting from S02 control would be expected to be similar in chemical
composition to those produced by wet processes using the same sorbents.
For lime-based dry scrubbing, the FGD wastes should consist primarily of
a mixture of calcium sulfite, sulfate, and unreacted lime.  The quantity
of unreacted lime, however, may be somewhat higher than in wet scrubbing
wastes owing to the higher stoichiometries that would probably be
required.   The mix of calcium sulfate and sulfite solids may also be
somewhat different, both in terms of their relative quantities as well
as the crystalline forms present.
     For dry systems utilizing alkaline sodium salts (e.g., nahcolite
or sodium bicarbonate)  the waste solids would be expected to contain in
addition to fly ash a mixture principally of sodium sulfate, sulfite,
chloride,  and unreacted carbonate.   These would be similar, then, in
composition to the wastes produced from once-through sodium solution
scrubbing except that the solids would be discharged as a dry material
rather than'as a liquid.
Liquid Wastes
     There are two different liquid waste-producing FGD processes that
are in commercial operation on combustion boilers—(1) once-through scrub-
bing using solutions of alkaline sodium salts, and (2) scrubbing with
ammonia-laden water.  Of the two, once-through sodium scrubbing has achieved

                                 2-8

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the widest acceptance, having been applied to many industrial steam
plants and a few utility boilers.  Once-through sodium scrubbing pro-
duces a waste liquor containing primarily sodium sulfate, sulfite, and
chloride at total dissolved solids concentrations generally in the range
of 15-30 wt%.  Most of these waste liquors also contain significant partic-
ulate levels since the systems are used ^or combined particulate and SO
control.  Frequently, the waste liquors are air-sparged to oxidize any
residual sulfite to sulfate, especially where wastes are discharged for
disposal.
2.1.2  Matrix of Disposal Options
     Numerous methods are potentially available for the disposal of FGC
wastes, the ultimate recipient being land or the ocean.  The feasibility
of disposal options can be categorized broadly on the basis of the nature
of the wastes and the manner (type) of disposal.
     Table 2.1 lists potential disposal options for the various types
of FGC wastes which can be generated.  An indication is given as to
which options are being practiced on a commercial scale and which
remain as reasonable potential.  Sulfur is included in this table
since long-term storage or even disposal of sulfur may be necessary
in some applications of recovery systems.  However, it is unlikely
that many sulfur producing recovery processes would be installed
without well-defined plans for sulfur utilization or marketing.
2.1.3  Current Disposal Practices
2.1.3.1  Current Fly Ash Disposal Practices
     Disposal of fly ash or bottom ash is currently practiced at some
390 plants in the United States where coal is utilized at least as a
part of the boiler fuel  [6].  A  complete survey of disposal practices
is not available, although some  general indications are available in
FPC Form 67 data  [6].  Such data,  though, are sketchy  and do not include
handling information.
     Radian  [7], in a recent study, undertook a survey of 64 plants with
a  total capacity of 50,900 MW  to develop some baseline information on
ash disposal practices.  Most  of the plants contacted  began  operation

                                 2-9

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                               Table 2.1
                        Potential Disposal Options
                                      Ash   FGD Waste   Codisposal   Sulfur
Land Disposal
   Wet Pond - Conventional
              Stacking (Gypsum)
   Dry Impoundment
   Surface Mine
   Underground Mine
C
C
P
C
P
C
P
P
C
P
C
C
P
P
P
P
Ocean Disposal
   Shallow - Outfall
             Concentrated (con-
             ventional) Dump
             Dispersed Dump
             Reef Construction
             (Stabilized)
   Deep - Concentrated (con-
          ventional) Dump
          Dispersed Dump
P
P
P
P
P
P
P
P
P
P
P
P
C - commercial practice
P - reasonable potential
                                     2-10

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in 1970-1978 and hence were relatively new.   The data were characterized
according to the disposal method used for each type of solid waste,  the
total coal-fired generating capacity of the  plant,  the solid wastes
collection equipment and the type of FGD systems used.  The data obtained
are summarized in Tables 2.2 and 2.3.  Provided the survey sampling  is
statistically representative of the industry (or, at least, the newer
fraction of total capacity), it appears that:
     •  While a greater number of plants use ponding of fly ash,
        the greatest quantity of material is disposed by landfill.
        Radian reports that, of the 45 plants providing detailed
        information (representing about 36,000 MW), none sold their
        fly ash, but some of the paid disposal includes material
        that was eventually sold.
     •  The majority of plants use ESP to collect dry fly ash but
        dispose of the ash by ponding; only 30% of the plants have
        dry fly ash handling and disposal.
     •  Nearly 17% of the plants pay another company to dispose of
        or otherwise haul away the ash and 5% sell the ash directly
        to some company.  In addition, a significant amount of the
        fly ash removed by paid disposal may be sold and utilized.
        Thus, the total amount of ash utilized is difficult to
        determine from the disposal data.
     Considering the emergence of bag filters for fly ash collection and
regulatory developments, the disposal of fly ash in managed fills in a
relatively dry state (with water for fugitive emissions control only) is
likely to be a major option.
2.1.3.2  Current Bottom Ash Disposal
     The above-mentioned Radian survey  [7] also included data on bottom
ash disposal which is summarized in  Tables 2.4 and 2.5.  Providing the
data are statistically representative of  the  industry, it  appears that:
     •  On a plant basis,  the vast majority wet  sluice bottom ash
        but less than half  of these  plants use ponding for dis-
        posal.  It is not  known why  this  discrepancy  exists.
                                  2-11

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                                 Table 2.2
                Fly Ash Collection and Disposal Practices
      Basis:  Radian Corporation Survey in 1978 for EPA
                                       Number of Plants    Percent of Plants
          Method                       Reporting Method    Reporting Method
 I.  Collection
     Dry Electrostatic Precipitator .          39                 61
     Mechanical (Baghouse, etc.)               8                 13
     Wet Electrostatic Precipitator            4                  6
     Particulate Scrubber                      2                  3
     Other                                    11                 17_
                         Total                64                100
II.   Disposal
     Ash Pond                                 26                 40
     Conveyed to Landfill (Dry)               19                 30
     Paid Disposal                            11                 17
     Sale of Fly Ash                           3                  5
     Intermediate Ponding followed
       by Landfill                             3                  5
     Other                                    _2_                	3
                         Total                64                100
 Source:   [7]
                                    2-12

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                               Table 2.3
             Fly Ash Disposal Practices by Quantity of Ash
     Basis:  Radian Corporation Survey in 1978 for EPA
                                      Amouut                      Percent
Disposal Method               (10  metric tons/yr)                of Total
Ponded                                3,148                         34
Landfill                              4,763                         51
Paid Disposal                         1,415                         15
Sold
Other                                 	3                         ^
                    Total             9,329                        100
Source:  [7]
                                    2-13

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                                Table 2.4
               Bottom Ash Collection and Disposal Practices
      Basis:   Radian Corporation Survey in 1978 for EPA
           Method
 I.   Collection
     Wet Sluiced
     Dry Conveyor
     Other
                        Total
Number of Plants
Reporting Method
       52
       11
       _±
       64
Percent of Plants
Reporting Method
       81
       17
        2
      100
II.   Disposal
     Ash Pond
     Conveyed to Landfill (Dry)
     Paid Disposal
     Sale of Bottom Ash
     Intermediate Ponding Followed
       by Landfill
     Other
       24
       17
        8
        6
                        Total
       64
       38
       27
       12
        9

        9
      	5
      100
Source:  [7]
                                     2-14

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                               Table 2.5
            Bottom Ash Disposal Practices by Quantity of Ash
Basis:  Radian Corporation Survey in 1978 for EPA
                                      Amount                      Percent
Disposal Method               (10  metric tons/yr)                of Total
Ponded                                1,763                         44
Landfill                              1,138                         29
Paid Disposal                           671                         16
Sold                                    444                         11
                    Total             4,016                        100
Source:  [7]
                                     2-15

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        Mechanical dewatering and dry disposal of bottom ash
        do. not appear to be common practice.
     •  On a quantity basis, the most common disposal method
        is ponding.
However, it is well to note that regulatory developments and economics
may tend to encourage disposal of dewatered wastes in managed fills
in the future.
2.1.3.3  Current FGD Waste Disposal
     As of the end of 1978, nonrecovery FGD systems were in operation at
28 power stations and more than 40 industrial steam plants throughout
the United States.  Another eleven wet particulate scrubbing systems
were also in operation at utility power plants.  Although SC>2 control
was not the primary function of these latter systems, they did achieve
some degree of 862 removal, producing a waste containing a significant
fraction of S02~related wastes.  Including wet particulate scrubbing on
utility boilers, the total FGD capacity amounted to an equivalent of
about 21,000 MW.
     Tables 2.6 and 2.7 summarize the operational FGD systems on utility
and industrial applications at the end of 1978.  The data shown in these
tables were obtained from PEDCo reports [4, 5 ] and utility and indus-
trial plant contacts.
     Of the operational utility FGD systems listed in Table 2.6, all but
that at Nevada Power Company's Reid Gardner Station produce a solid waste
of calcium-sulfur salts.  In contrast, the overwhelming majority of FGD
systems on industrial boilers convert the S02 removed to a liquid waste
of soluble sodium salts.  Thus, while there are no definitive data on
waste generation rates, it is clearly evident that most of the wastes
being produced are solid wastes, and that essentially all of it is being
generated by utility FGD systems.  This is a trend which is expected to
continue at least over the next ten years.
     In order to gain a better perspective of waste generation and disposal
in utility FGD systems, the information provided in Table 2.6 has been
compiled in Table 2.8 according to waste type, disposal mode and general
plant location.  This compilation points out some interesting trends
in current utility waste generation and disposal practices.
                                  2-16

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                                                                                                    Table   2.6

                                                 Nonrecovery  FGC  Systems  in Commercial  Operation  on Utility  Boilersc
t-o
 i
                         SOj camoL SYSTEMS.

                     Alabena Electric Coop
                     Arlaoaa Electric Power Coop
                     Arlaona Public Service
                     Central Illlnola Light
                     City Utllltle. of Springfield
                     Coluabua ft Southern Ohio
                     Hueueane Light

                     Indlanapolle Power • Light
                     Kenaae  City Power 6 Ll(ht

                     (aneee  Poor 6 Light

                     Kentucky Utllltle.
                     Lo.lKllle Can 1 Electric
mnnkota Power
Nontene Pont
Northern. State* Power
PanBtaylven.la Power
Southern Carolina Public Service
toutken Mleele.lnpl Electric
T.IM1..... Valley Authority
Temaa Utllltla.

Otoh Power 4 Light

    PAHTICULATE CONTtOL STSTOg
    - »TT SCHUlaO:

Arleoae Public Servlcee
CiiJiiilnialth Edlaon
Detroit tdleon
Ulnneoot. Power 4 Light

Nentnae - Denote Dtllltlee
Nevada Power
Pacific Power 4 Light
Publle Service Cowpaav of Colorado
                    Southweet Public S«r»lcc»
To-hlghea dolt 2)
Ap'cha  (Unl: 2)
CholU  (Unl:. U2)
Duck Cr.ek  Unit 1)
Southv.it (l.nlt 1)
ConcayllU 'Unit. }to)
ClriM  (U«ln 1-*)
Phillip. (Urlt. 1-6)
Pet.raburg (Unit 3)
taothonw (iinlca U<)
UCyn«  (Unit 1)
J.fferoy (Unit 1)
Lovrenc. (Urlt. 4iS)
Cr«n ll»r (Unit* 1-3)
Can. Hut (Utlta 445)
Hill Creek (Unit 3)
Peday'e tun (Unit 6)
Hilton  I. YOiUl (Unit 2)
Col.trip (Unite 142)
Shetbume (U.ilte 142)
truce HeaefleU (Unit. 142)
Hlnyeh  (Unit 2)
I.D. Norton (Uo.lt 1)
Uldou'a Creek (Ue.lt I)
Martin Lake ;Unlt. 142)
hontlcrllo (»elt ))
Huntlngtoe (lalt 1)
                                                     Pour Comer. (Unit. 1-3)
                                                     Hill County (Unit 1)
                                                     St.  Clelr (Cult e)
                                                     Aurora (Ualt. 1(2)
                                                     Clay joeu.ll (Unit 3)
                                                     Loul. 4 Clerk (Unit 1)
                                                     laid Caraner (Unit. 1-1)
                                                     Hac
350
Coal Sulfur
Content (I)

0.5-1.0
0.5
2.5-3.0
3.5
4.5-5
2.0
2.0
3-3.5
0.5-1
5.0
0.5
0.5
4.0
3.5-4.0
3.5-4.0
3.5-4.0
0.7
O.S
O.S
4.0-5.0
1.0
1.0
3.0-4.0
1.0
1.5
0.5
O.S
<1.0
0.3
1.0
1.0
0.7
0.5
0.5
0.6-1.0
0.6
0.7
0.5
Scrubbing Syateat
Mode
SOj
SO,
SOj + Aah
SO,
so,
S02
SO, + Aah
SO, * Aah
SO,
SO, + Aah
SO, + Aah
SO,
SO, + Aah
SO, + Aah
SO,
SOj
SO,
SO,
SO, + Aah
SO, + Aah
SO, + Aah
SO,
SO,
so,
S02
so.
S02
Aah
Aah
Aah
Aah
Aeh
Aeh
Aah
Aeh
Aeh
Aah
Aah
Aah
Alk.ll
Llneatone
Llneetone
Lleeetooe
Llneetone
Llneatone
Line (Thloeorblc)
Line (Thloaorblc)
Line (Thloeorblc)
Llneatone
Line
Llneatone
Llneatone
Llneatone
Line
Line (Carbide)
Line (Carbide)
Line (Carbide)
Aah (+ Line)
Aah (+ Line)
Llneatone
Line (Thloaorblc)
Llneatone
Llajcatone
Lleeetone
Lleeatone
Llneetone
Line
Source
Thickener
Scrubber
Scrubber
Thickener
Fllte
Fllte
Fllte
Fllte
Fllte
Thickener
Scrubber
Scrubber
Thickener
Scrubber
Thickener
Thickener
Filter
Filter
Settling Pond
Thickener
Thickener
Thickener
Filter
Scrubber
Filter
Scrubber
Filter
(Line) Thickener/Settling Pond
(Llneetone)
none
None
None
(Llaetetone)
(Soda Aah)
(Line)
None
Thickener
Scrubber
Scrubber
Thickener
Scrubber
Scrubber
Settling Pond
Settling Pond
None Thickener/Settling Prod
None
(Llneatone)
Settling Pond
Thickener
Unate For.
Proceaaloa.
Nona
None
None
Aah Added
Nonproprletary Stab. (Aah + Line)
Connerclal Stab. (IUCS)
r-i irclal Stab. (IUCS)
Coaejerclal Stab. (IUCS)
Connerclal Stab. (IUCS)
None
Nona
Aah Added
None
Nona
Nona
Nona (Codlapoaal la Aah Pond)
None (Codlapoaal In Aah Pit)
None
None
(Forced Oxidation)
Coneerclal Stab. (Dravo)
Nona
Nona
Aah Added
Aah Added
None (Codlepoeal In Aah Pond)
'Aah Added
None
Nonproprletary Stab. (Aah * Line)
None
Nona
None
None
Nona
None
Line Added
Line Added
Lleeetooe Added
None

Final Olapoaal
Uet Pond (L)
Uet Pond (u)
wet Pond (u)
wet Pond (u)
Dry Fill
Dry Fill
Dry Fill
Dry Fill
Dry Fill
Uet Pond (u)
Uet Pond (u)
Uet Pood (L)
Uet Pond (u)
wit Pond (u)
Uet Pond (u)b
Uet Pond (u)»
Dry Fill
Dry Pill (Mine)
Uet Pond (u)
Uet Pond (L)
U*t Pond (u)
Uet Pond (u)
Dry Pill
net Pond (u)
Dry Fill (Mine)
UetOlbd (u)
Dry Fill
Dry Fill (Mine)
Dry Fill
U. Pond (L)
Ue Pond (u)
Ue Pond (u)
Ue Pond (L)
We Pond (u)
Dry Pill
Dry Pill
Dry Pill
Dry Fill
Hat Pond (u)
                    'tnela:  Nmmber 1*71
                    kMapoeal operation. Kill be converted la 1»7» to err

                         alf of boiler capacity la acrubbed
                                                         t with etabllliatlon.
      Source:    Arthur  D.   Little,   Inc.

-------
                                                                             Table  2.7

                                    Nonrecovery  FGD  Systems  in  Commercial Operation  on Utility  Boilers0
to

h-1
CO
                        Company
                   SOLID HASTE;

               Araco Steel
               Caterpillar Tractor
Firestone Tire  & Rubber
General Motors
Rickenbacker Air Force Base

     LIQUID HASTE!

Alyeska Pipeline Service
American Thread
Beldrldge Oil

Canton Textiles
Chevron U.S.A.
FMC
General Motors
               Georgia Pacific
               Getty Oil
               Great Southern Paper
               Great Western Sugar
               ITT Eayonler
               Xerr-McGee Chemical
               Minn-Dak Farmer's Coop
               Mobil Oil
               Sheller Globe
               St. Regis Paper
               Texaco
               Texas Gulf


Plant
Middle tovn, OH
East Peoria, IL
Jollet, IL
Morton. IL
Mosavllla. IL
Pottstovn , PA
Parma, OH
Columbus, OB
Valdez, AK
Marlon, NC
McKit trick, CA
McKlttrick, CA
Canton, GA
Bakersfield, CA
Green River, HT
Dayton, OB
Pont lac, MI
St. Louis, MO
Tonavanda, HT
Croaset, AR
Bakeirsfleld, CA
Cedar Springs, GA
Billings, MI
Flndlay. OB
Fort Morgan, CO
Caring, HE
Greeley, CO
Loveland, CO
Scott* Bluff, HE
Femandlna Beach, FL
Trona, CA
Hahpeton, ND
San Ardo, CA
Norfolk. VA
Cantonment, FL
San Ardo, CA
Granger. HT
Flue Gas
Handled
(SCFM)
84.000
210,000
67,000
40,000
140,000
8,000
128,000
50,000
50,000
18.000
12,000
12,000
25,000
248,000
446,000
36,000
107,000
64,000
92,000
220,000
72,000
420,000
60,000
65,000
65,000
110,000
25,000
122,000
65,000
201,000
500,000
105,000
182,000
8,000
115,000
366,000
140,000
Haste Diaposa^
# &

Fuel
LS Coal
HS Coal
US Coal
HS Coal
HS Coal
HS Coal
HS Coal
HS Coal
LS Oil
LS Coal
MS Oil
HS Oil
LS Coal
HS Oil
LS Coal
LS Coal
LS Coal
HS Coal
LS Coal
Bark/Oll/Coal
LS Coal
Bark/Oll/Coal
LS Coal
LS Coal
LS Coal
LS Coal
LS Coal
LS Coal
LS Coal
Bark/Oil
Coal/Cake/Oil
LS Coal
HS Oil
LS Coal
Bark/Gas/Oil
MS Oil
HS Oil
Scrubber
Type
Direct Lime
Dual Alkali
Dual Alkali
Dual Alkali
Dual Alkali
Dual Alkali
Dual Alkali
Direct Limestone
Sodium Hydroxide
Haste Caustic
Sodium Hydroxide
Sodium Hydroxide
Haste Caustic
Soda Aah
Soda Ash
Sodium Hydroxide
Sodium Hydroxide
Sodium Hydroxide
Sodium Hydroxide
Haste Caustic
Soda Aah
Haste Caustic
Ammonia Hater
Soda Ash
Ammonia Hater
Ammonia Hater
Ammonia Hater
Ammonia Hater
Ammonia Hater
Sodium Hydroxide
Caustic Brine
Ammonia
Sodium Hydroxide
Sodium Hydroxide
Sodium Hydroxide
Sodium Hydroxide
Soda Ash
System
Mode
SO} + Aah
SO, + Ash
SO, + Ash
SO} + Ash
SO, + Ash
S02 + Ash
SO} + Ash
SO} + Ash
SO} (+ Ash)
SO} + Ash
SO,
SO,
SO} + Ash
SO} (+ Ash)
S02
SO} + Ash '
Alh (+ SO,)
SO}
SO} + Ash
SO} + Ash
SO}
SO} + Ash
SO}
SO} -I- Ash
SO} + Aah
SO} + Ash
SO} + Ash
SO} + Ash
SO} + Ash
SO} + Ash
SO}
SO} + Ash
SO}
SO} -1- Ash •
SO} + Ash
.SO, + Aah
soj

Haste Form
Slurry
Filter Cake
Filter Cake
Filter Cake
Filter Cake
Filter Cake
Filter Cake
Thickened Slurry
Slurry
Slurry
Solution
Solution
Slurry
Slurry
Solution
Slurry
Slurry
Solution
Slurry
Slurry
Solution
Slurry
Solution
Slurry
Slurry
Slurry
Slurry
Slurry
Slurry
Slurry
Solution
Slurry
Solution
Slurry
Slurry
Slurry
Solution
v£
W'tf
X
X
X
X
X
X
X
X

X


X
X
X

(X)



X
X


X
X
X
X
X
X
X

X
X



' *47
if V








X

X
X
(X)


X
X
X
X
X


X
X
X
X
X
X
X
X
X
X

X
X
X
X
                    'Systems producing sulfur or where scrubber liquors are returned to process  for use are not included.

                    Rotations  for both vastewater treatment and ponding (or dry filling) Indicate operation* where solids are removed via settling
                    (or filtration) and waste liquor is treated and discharge.
          Source:   Arthur D.  Little,  Inc.

-------
                                                   Table  2.8

                           Summary of Disposal Practices  for Operational FGC Systems
                                    on Utility Boilers as  of November 1978
                                                               Number of Plant/Plant Capacity
Waste Forn System Type
FGD Waste Only Lime-Based
Limestone-Based
Total
Codisposal Lime-Based
N> Limestone-Based
jL Wet Particulate Scrubbing
vO Total
Stabilized FGD Waste Lime-Based
Limestone-Based
Wet Particulate Scrubbing
Total
TOTALS

Wet Pond
Dry Fill
0/0
2/865
1/1585
5/1685
8/4135
—
0/0
8/4135
Lined
oTo
2/2040
1/50
3/2090
—
0/0
3/2090
Unlined
1/200
1/200
2/960
4/2460
4/1195
10/4615
—
0/0
11/4815
Total
0/0
1/200
1/200
4/1825
7/6085
10/2930
21/10840
0/0
0/0
0/0
0/0
22/11040
Dry Fill
o~7o
1/65
1/180
27245
3/1720
2/730
1/165
6/2615
8/2860

Wet Pond
Lined
1/225
1/225
1/165
T7165
~
0/0
2/390
Unlined
1/140
1/140
3/850
2/950
5/1800
1/1650
1/1650
7/3590
Total
0/0
2/365
2/365
4/915
3/1130
1/165
8/i210
4/3370
2/730
1/165
7/4265
17/6840
TOTALS
0/0.
3/565
3/565
8/2740
10/7215
11/3095
29/13050
4/3370
2/730
1/165
7/4265
39/17880
Source:  Arthur D. Little,  Inc.

-------
     •  Of the total number of FGD plant installations and FGD
        plant capacity, 60% (23 plants and about 10,900 MW)
        utilize wet ponding for ultimate disposal while 40%
        (16 plants and about 7,000 MW) use some form of dry
        fill.
     •  Of the FGD systems utilizing ponding, approximately
        three-quarters involve unlined ponds, and only about
        one-quarter involve lined ponds.  (The majority of
        systems also prethicken wastes prior to pumping to
        the disposal ponds.)
     •  Of those systems utilizing dry fill, the overwhelming
        majority of plants (about 80%) operate dry landfill-type
        impoundments, although three plants  (20%) are currently
        disposing of wastes in surface mines.
     •  Over 90% of the plants and FGD capacity utilize codisposal
        (with or without stabilization).
     •  There are no operating utility systems involving dry fill
        of ash-free FGD wastes (nor is there any industrial-scale
        dry fill of ash-free wastes).
     •  There is no stabilization of FGD wastes in Western plants.
     While about 40% of the utility FGD systems currently
utilize some form of dry impoundment, the trend toward dry impoundment
is expected to grow over the near future.  In 1979, an additional
7,500 MW of nonrecovery FGD capacity is due to come on line, all of
which will involve S02 control only.  Of this total, 6,700 MW will
produce solid wastes, approximately 85% of which involve some form of
dry impoundment.   Thus, by the end of 1979,  the capacity of nonrecovery
FGD systems involving dry impoundment will grow to 50% of the total
utility FGD capacity.
2.1.4  Field Studies of FGC Waste Disposal
     There are now underway eight field-scale test and monitoring programs
of FGC waste disposal.  Five more programs are in planning and are
scheduled to begin sometime in 1979, and another is being proposed.
                                 2-20

-------
   Table 2.9 lists these field testing programs along with the sponsors,
   contractors and the range of waste and disposal modes tested.
        It is interesting to note that these programs encompass all  types
   of FGD wastes as well as all of the basic disposal modes available.   Of
   particular importance are the full-scale and prototype studies.   Most
   of these focus on one type of waste or disposal mode.
        An upcoming program of significance is the multiple-site  test
   program planned by EPA.  It will involve monitoring more than  a dozen
   FGC waste disposal sites including a variety of different  types of wastes
   and disposal modes.  This two-year effort is scheduled to  begin in late  1979,
        The scope of each of the programs listed in Table 2.9 is  discussed
   briefly below.  These studies will be referenced and highlighted  through-
   out the remainder of this report as they apply to specific issues.
•Of taMr <•*•!•)
                       «o, felr
                       M^ tely
                       •0,01, U_
                 o/iWB.   n,feir u»
                                           *•• Q*» XMAtUW* I
                                           •**>~Hl
tm^m^ OBi
                                     2-21

-------
                                                                                   Table  2.9

                                        Summary of  Current  Field Testing Programs  for  FGC  Waste  Disposal
N3
 I
ro
•alia: Statua aa of atonal
Location Utliltr (Plant)*
LAMP DISPOSAL;
Hlnnlot. Pover (H.I. To«|)
Culf Poucc (Seholi)
Coif Povar (Ickolt)
— Vn-— A >. oalo
(CroasvllU)
Loulavllla Gaa t Uactrlc
Louisville Caa t Uoctrlc
TVA (T>»»nf)


OCEM DISPOSAL:
D*—.. i Mir
EPA ci/ua/in. 90, o»ir
CPA lacktal SOj 0»lj
CPA/TTA TVA/iodiCal ID. A
/Aaroapac. foi » Aafc
•Oj oair
.

uOC/IPA/EPIV/ OBI/IUCS fO, t Aak
nntDA/pAsn
DA aVA/ADL §0j t
ID, t Aak
p*ar (ram
TIM Trv*
AlUllaa Art lallata-llch
LteastoM Crcaaai
a»al Alkali fwlflU-Uek
LXaa (TUloaorttc) Inlflta-Uck
U*a (CarkUo) talflto-Uck
Baal Alkali lalflta-tlck
Uaa A 1 ta»ar»»a aaaflto-Uck
Llaastoaa (Porcad Cypaiai
(Xlaatloa)

Uaa (nioa.rt.lc) talflto-Uck

•-T "-T

Haata Ckaractarlaclca
rm Umiil Maoa
•art aea Hlaa
rilur Caa* (aaMaklliiW) atacklaf
mic.aail Uarrr (UaataklllsaO *» *•> ""•••••'
Plltar Oka (ItaalllaW A ""--*•*" — •*) *^ Ia»»«a«a«a«
"U" £** (**ili-<> .,, 1,1 i t
riltar Oka (Itaklllaas' A IkMtaklllaaO l»a»aaaaa«
nitar Caka (MaklllaW) fc( « ia. In inlailll
(Pllt.r Caka )
{Coatrlf«ta Caka Ustablllaa* A laata*lllaa<) Irr la»*»aa>B»t
(iklckaavl llarrr)
Plltar Caka


•aox CMkaftractloD
riltar Caka (ItakllliW)
fn«ea»tratoa Daap
>A-r


TMC Araa
Uctloa of Hlaa
^1-Acra Ana
1-Acra Pit
SO-Acra Uta
aaall Plta/Poaoa
J
I * Pita (<.l acra)
4 Pita/Araa



Ml. 2 Acca
1/2-Acra Poad


                   •ADL  - Artkw D. lattl.
                    CE   - Co*u.tlOB
                    CIA  -
                    CIC  -
                    DOR  - DDparCMBt of barer
                    EPA  - U.S. bviroMMtal Protftcclon Afar
                    EPtI - llKtilc POVEC Inured lutltet*
                    1UCS - IU Comraloa
                    LCI  - U>ul««lll« Cu _d Uwtrlc
                Aoaarliai
       lav Toik Stata aaortr aaaaarca A Bnalof»jaW Aittborlty
PAtBT  - Po»n AMkorlcr of tka Stata of lav lot* •
tan   - ttata omliaraltr of law tort
TfA    - Til	 Tailor AMkocltr
UL     - Oalmriatr of L««1«»11U
•D    - Oklviraltr of fcrtb Dakota

-------
2.2  Disposal on Land
     At present, all FGC wastes are disposed of on land.   There are five
basic modes of land disposal, as noted in Table 2.1, which are considered
as potential options for large-scale disposal operations:
a.  Wet ponding
    •  Conventional wet ponding of coa]  ash, FGD wastes and
       stabilized FGD wastes as now commonly practiced.
    •  Gypsum stacking which is not now practiced but which
       is being investigated for FGD gypsum.
b.  Impoundment of dry or dewatered wastes in managed fills including:
    direct impoundment of ash, FGD wastes, combined ash and FGD wastes
    (codisposal), and stabilized wastes; and excavation and landfilling
    of wastes from interim ponds.
c.  Mine disposal
    •  Surface mine disposal including pit bottom and spoil bank
       placement of wastes.
    •  Underground mine disposal.
Of these five basic options, only three are now being commercially
practiced.  There are no stacking or underground mine disposal opera-
tions at present.  However, all of these are expected to be practiced
in some form or other in the near future.  Table 2.10 summarizes the
five modes and principal variations in terms of commercial practice.
2.2.1  Wet Ponding
2.2.1.1  Conventional Practice
     Wet ponding is presently more widely employed  than any other method
but is expected to be less widely used in the  future.  A number of engi-
neering variations are possible in a ponding system.  To provide a back-
ground on some pond operations, a brief summary of  five ponding operations
is presented in Table 2.11.   Schematic diagrams of  each of the five ponding
schemes are presented in Figures 2.1 to 2.5.
     The implementation of a  pond disposal  system depends  upon the type
of wastes being generated and  the manner  in which it  is handled.   In the
case of dry fly ash collection  systems, the ash can be either  directly
sluiced using a hydrovac system and pumped  to  the pond, or pneumatically
conveyed to a transfer system where the ash is mixed  with  sluice water
and pumped  to the  pond.  Bottom ash is  usually removed from  the bottom

                                 2-23

-------
hO
-e-
Wet Ponding
   Conventional

   Stacking

Dry Impoundment

Mine Disposal
   Surface

   Underground
                                                    Table 2-10
                                       Summary of Land Disposal of FGC Wastes
                              Variation

                              Lined
                              Unlined
                              Pit Bottom
                              Spoil  Bank
                              Wet Waste
                              Dry Waste
                                                                          Type of Waste
Ash
X
X
X
X
X
FGD Only Codisposal Stabilized FGC
X X
XX X
X X
X
X
        X - Indicates being commercially practiced.

-------
                                                         Table  2.11

                            Typical FGD  Waste  Disposal  Operations  - Wet  Disposal
Ho.
1
2.
3.
4.
5.
6.
Detail
Company and Location
Plant Size MW
Fuel (average values)
FGC System
Scrubber Reagent
Waste Disposal
Colstrip Plant
Montana Power,
Colstrip, Montana
716
Ash-8.6Z; S-0.77Z
CEA Venturi Scrubber
& Koch Tray + Ab-
sorber Tray.
Alkaline Fly Ash and
Lime.
Settling Pond + Evap-
                                                    LaCygne Plant
                                                                             St.Clair Plant
                                                                                                  Sherburne Plant
Reference
                       oration Pood
[5.9]
                                               Kansas City Power & Light   Detroit Edison         Northern State Power
                                               Linn County, Kansas         Belle River, Michigan  Becker, Minnesota
      874

Ash-24-25Z;  S-5.6I

B&H Venturi  + 2-stage
Perforated Tray Absorber


Limestone


Ponding



[10]
                                                                               325

                                                                          Ash-4.25Z; S-0.75X
                                                                            1500

                                                                        Ash-9Z; S-0.8Z
                                                                          Peabody-Lurgi Venturi CE Venturi -t- Marble
                                                                          Scrubber              Bed Scrubber
                                                                          Limestone
                                                                          Clay-lined Pond
                                                                          [11]
                                                                        Alakaline Fly Ash and
                                                                        Limestone.

                                                                        Thickening and Perman-
                                                                        ent Disposal Pond
[5,9]
                       Bruce Mansfield Plant

                       Pennsylvania Power
                       Shipping Port, Penn.

                            1620

                       Ash-12.5%;  S-4.3Z

                       Chemico Scrubber &
                       Absorber System


                       Lime
Dravo Process Stabili-
zation and Permanent
Disposal Pond

[12,13]

-------
    RECYCLE STREAM
      SCRUBBER
                       BLEED
                   n
                      EFFLUENT
                       TANK
                                                   FLYASHPOMD
                                            DREDGE
                                                 SUPERNATANT
                                           FLVASH CLEAR
                                           WATER POND
                                                                                  SLURRY
                                                                                                  SUPERNATANT
                                                                                                 SMI
                                                                                       EVAPORATION POND
Source:   [9]
                       Figure  2.1  Waste Handling Colstrip Plant
                                     Montana  Power  Company

-------
                           RECYCLE STREAM
tsj
N>
                             SCRUBBER
                              PLANT
                                                                  BLEED
 SETTLING
  AND
PERMANENT
 DISPOSAL
  POND
                                                          SUPERNATANT RETURN
                Source:   [9]
                                              Figure 2.2  Waste Handling LaCygne Station
                                                           Kansas City  Power & Light Company

-------
            TO
         SCRUBBER
              FROM SCRUBBER
              AND SPRAY TOWER
LIMESTONE
1



1 SPENT SCRUBBING
(SOLUTIONS
RECIRCULATION
TANK


SLURRY
TANK


1
f
MIX
TANK
POND
WATER
                                      OVERFLOW
                                        SUMP
     -\	W
        \=^
WASTE DISPOSAL
      POND
Source:   [11]
               Figure 2.3  Waste Handling St. Clair Plant
                           Detroit Edison Company
                                 2-28

-------
                           RECYCLE STREAM
                                SCRUBBER
                                 PLANT
to
I
NJ
                                                            BLEED
                                                                           THICKENER
                                                               OVERFLOW
                                                                                        UNDERFLOW
                                                                                                            SETTLING
                                                                                                             AND
                                                                                                           PERMANENT
                                                                                                            DISPOSAL
                                                                                                             POND
                                                              SUPERNATANT
                  Source:   [9]
                                           Figure 2.4   Waste Handling Sherburne Plant
                                                         Northern States Power Company

-------
CALCILOX
ADDITIVE
THICKENED
WASTE FROM
FGD SYSTEM
                          SLURRY
                          PUMPS
                           MANIFOLD
                                    MANIFOLD
                                              PIPING
                                              SYSTEM
                                              (7.3 MILES)
                                                                      SUPERNANT
                                                                     -, RETURN
                                                                      I
                                                 \=_ RESERVOIR  ^:
  Source:   [12]
                    Figure 2.5  Waste Handling - Bruce Mansfield Plants -
                                Pennsylvania Power Company

-------
of the boiler using a sluicing system and pumped separately to a disposal
pond (sometimes a separate pond from that used for fly ash).  In the case
of wet scrubbers, wastes from particulate control, SC>2 control, or combined
particulate and 862 control systems, there are two basic approaches.  The
wastes can be pumped directly from the scrubber to the disposal pond, or
the wastes can be dewatered first via thickening/clarification prior to
being pumped to the pond.  In some wet scrubber systems for S02 control,
the wastes (thickened or unthickened) are first mixed with sluiced ash
or combined with additives for stabilization.
     In almost all cases, provision is made for returning supernate to
the process.  This is particularly true for ash ponding systems and FGD
systems discharging unthickened wastes directly to ponds.  Here, water
management and conservation dictate water reuse.  However, not all ponding
systems incorporate water recycle and many which  do  include this  feature
practice  only partial recycle.  For new systems constructed in the  future,
recycle and optimum water management are  anticipated to be mandatory.
     Wet  ponding may be technically employable for a variety of FGC
wastes including stabilized FGD wastes only if two conditions  are met:
     •  A site is available that can be converted into a reservoir
        with minimum construction of dams or  dikes or excavations.
        Otherwise, costs rise rapidly.
     •  The additive for wet stabilization is available at reasonable
        cost.  Lime-fly ash stabilization processes  cannot be  applied
        to slurries  (only to dewatered FGC wastes).   Dravo's process
        using Calcilox® additive is  the only  stabilization
        process  commercially available for stabilizing slurried
        FGC wastes.  Such specialized additives may  be manufac-
        tured at one or few locations.  Transportation costs  for
        the additives beyond a certain distance from point  of
        manufacture  may be high and  preclude  such stabilization
        processes.
Nevertheless, under  site  specific  conditions, these  processes  can be
applied.   In addition to  Bruce Mansfield, Allegheny  Power System's
                                 2-31

-------
Point  Pleasant Plant will employ an analogous Dravo system.  This is
likely to be operational in 1979 [14].
     An  important consideration in pond design is control of leachate
movement.  The conventioanl approach is to site ponds in areas where the
underlying soil has low permeability.  Dams are constructed of borrow
material of low permeability to minimize seepage.  If the wastes were
hazardous and were to be regulated under Section 3004 (which does not
apply  to FGC wastes), earthen dikes would be required to be formed of
relatively impervious soil.  If the permeability of the wastes and the
underlying soils are not sufficiently low to control seepage to desired
levels,  artificial liners or sealants can be employed.  This is not common
practice for FGC waste disposal by ponding and may not be required for
stabilized FGD wastes.  Where needed, the potential options for liners are;
     •  Clay sealants like bentonite mixed with granular soils.  They
         offer superior linings for landfills and ponds because they
         provide acceptably low permeabilities and can be expected to
         self-seal in the event of a rupture.  Their main drawback,
         however, is a high transport cost when not available locally.
     •   Chemical sealants—These are sprayed into the soil in a
         landfill or pond in order to plug the interstices.  They can
         be difficult to apply, but are less expensive than clay
         sealants in areas where swelling clays are unavailable.
         However, chemical sealant liners are more permeable than
         those of clay.
     •   Synthetic liners—Synthetic liners are the most effective
         type available.  They can be effective and are easy to install
         but puctures can seriously nullify their effectiveness.
         Field experience with such liners in large ponds is limited.
     •   Stabilized FGD wastes, themselves, can be employed as liners.
     Two important elements in a ponding system are:
     •   Design of the pond itself,  and
     •   Design of the pipeline system including interfacing.
These are discussed below.
                                  2-32

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Pond Design
     Pond design is based on construction of dams or dikes and, in a
few cases, based on excavations in the ground.   Ponds can be built
on slopes.  Some potential pond designs are illustrated in
Figure 2.6.  However, the construction of dikes or other means of
containment for ponds is usually expensive.  In the future, particu-
larly if stabilization of FGD wastes is widely practiced, ponding will
probably be limited to those sites that can be converted to a pond with
minimal construction of dams or dikes.
Pipeline Systems
     The four principal factors most important to the design of pipeline
systems are:
     •  Solids settling,
     •  Erosion/abrasion potential,
     •  Corrosion potential, and
     •  Freeze protection.
Of these, avoidance of solids settling in pipelines is usually the
overriding factor in design.  Usually, an FGC waste can be conveyed
hydraulically.  To prevent settling, conveying velocities  usually
range between 1.5 meters and 3.7 meters per second  (5-12  ft/sec),
depending on material density, particle size and  conveyor  pipe con-
figuration  [16].  For coarser materials, such as  bottom  ash and mill
rejects,  conveying velocities will be  in the higher range, particularly
in vertical pipes such as may be encountered when pumping  to elevated
dewatering bins.  In long pipelines handling coarse materials, velocities
must be increased  above those  used for shorter lines.   In addition,  some
device  to create turbulence must  be introduced to maintain homogeneous
slurry  mix,  particularly when  conveying bottom ash or  mill rejects.   Fly
ash slurries with  finer particles can be pumped at the lower  range of
velocities as can  be FGD wastes.
      A  key parameter in pipeline  system design is the  percentage of
solids  in the slurry.   This is determined by the three fundamental
                                  2-33

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                                                          Side  Hill  pond
                                                        Diked Pond
                                                       Incised Pond
Source:  [14]
                        Figure 2.6  Pond designs

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physical properties:  crystal morphology, particle size, and density of
the waste.  System design should emphasize reliability of service and
avoidance of maintenance problems like settling, plugging or solids
buildup in critical parts.  FGD wastes and fly ash are often conveyed
at 10% to 25% solids while higher loadings are possible for bottom ash.
The bulk density of the conveyed slurry is usually well below 1.2 gm/cc.
     It is also noted that pipeline optimization is only important if
the line exceeds about 1,200 meters (4,000 feet) in length.  The usual
practice in short pipelines is to convey the waste as a dilute slurry
and provide adequate redundancy to ensure reliability of service.
     Radian [7] reports on distance to disposal site for 54 plants and
concluded that:
     •  Nearly 93% of all bottom ash and fly ash from the
        representative 54 plants is transported less than
        8 kilometers (five miles) from the generating plant
        to the ultimate disposal site.  This is a strong
        indication that the cost of transporting large volume
        wastes over long distances is generally avoided,
     •  The mean distance from the plant to disposal sites
        was 4.8 kilometers (three miles) for this representa-
        tive group of 54 plants and is considered realistic
        for the industry as a whole.
2.2.1.2  Gypsum Stacking
     FGD processes can produce gypsum either by intentional  forced
oxidation or in cases when the sulfur content of the coal  is low.   In
either case, the special  case of wet ponding called "gypsum  stacking"
may be applicable even  though it is not  practiced now.   EPRI is
sponsoring a study  of gypsum stacking at the Scholz plant  of
Gulf Power Company  in conjunction with the  testing of  the  prototype
Chiyoda 121 FGD process.
     It should be noted that gypsum stacking is common practice  in the
phos-acid industry.  A brief description of gypsum stacking  as  it is
practiced in the phos-acid industry  [17] is given below to provide
                                  2-35

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some insight on how it may be applied to FGD gypsum.  However, data
are not available to indicate that phos-gypsum and FGD gypsum are
fully analogous in terms of physical and chemical characteristics.
For example, occluded waste liquor in phos-gypsum is quite acidic
(pH of 2 to 3).  FGD gypsum liquor, on the other hand, has a signifi-
cantly higher pH.  This factor alone may cause differences in physical
stability of the gypsum in the stacking operation.
     The phos-gypsum waste is usually transported as a waste by pipeline
to a pond created by construction of starter dams usually from local
borrow materials.  Phos-gypsum as a slurry is discharged by spigotting
into the pond.  Gypsum settles rapidly and supernate is piped back to
the process plant and used as makeup water.  As the quantity of gypsum
builds up in the pond, the freeboard between pond level and dike top
decreases.  When the freeboard between pond level and dike top needs
to be increased, the dike is raised by borrowing material from the
dried surface of the previously deposited gypsum, and the cycle is
repeated.  Dredging and dozing are the usual means of achieving the
buildup of the dike.  The operation is usually conducted in such a
way that deep trenches are not left along inside edges of embankments.
With this method, each successive dike moves further upstream and is
underlain by the previously deposited gypsum.  In some cases, these
dikes permit seepage of contaminated water through them.  It is neces-
sary to collect and reimpound seepage, primarily because of the fluoride
present in it.  Seepage collection and reimpoundment are facilitated by
construction of a seepage collection ditch around the perimeter of the
gypsum pond, as depicted in Figure 2.7, along with a pump station at the
collection point of the seepage ditch to move the collected seepage water
back into the gypsum pond [18].   Permeability of the dams or dikes can
be minimized by segregation of phos-gypsum fines if needed [19].  Seepage
collection may not be required for FGD gypsum except in site specific cases,
     Preliminary indications from EPRl's test program on FGD gypsum
stacking are favorable.   Tests are continuing and are expected to be
completed by late 1979 [15].
                                 2-36

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                          SEEPAGE  DITCH RETURN
                          TO GYPSUM POND  SY PUMP
                                              .OUTSIDE  or
                                       APPROXIMATELY
                                       10 FT  WIDE »Y
                                       ABOUT 3 FT DEEP
                                        SURFACE DRAINAGE DITCH EXTERNAL

                                      SEEPAGE    T° ™l
                        SEEPAGE DITCH
Source:   [18]
       Figure 2.7   Proposed Gypsum Pond Water Seepage Control
                     System  Using a  Collection Ditch  Around the
                     Perimeter (EPA  Effluent  Guidelines Document)
                                    2-37

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2.2.1.3  Research Efforts in Ponding
     Recent study efforts in this means of disposal have centered on
two issues:
     •  Most effective means of containing pollutants within the
        disposal area; i.e., study of potential liner material, and
     •  Better definition of leaching from lined and unlined ponds.
Liners for Ponds
     Unlined disposal ponds are usually the least expensive method of
waste disposal.  This technique, however, has been subject to criticism,
primarily due to the potential for waste contaminants to enter the ground-
water.  Nonetheless, many FGD waste disposal systems in operation use
unlined ponding for either intermediate clarifying or ultimate disposal.
The use of unlined ponds for waste  disposal is expected to decrease
in the future.
     Liners can be of any material including site soils (properly treated)
or materials not native to the site and are used to reduce permeation.
Liners potentially can reduce pollutant mobility and can conserve water
for recycle.  At present, the major problem with liners has been high
cost and lack of real time experience under field conditions (i.e.,
questionable longevity).
     In principle, the criteria that are important for a liner material
are [20]:
     •  High strength and elasticity,
     •  Good weatherability and long life  expectancy,
     •  Resistance to bacterial and fungal attack, and
     •  Ease of repair.
In addition, the pond design may  include a leakage detection system.   One
such system consists of underbed  drainage  channels which collect  the  leak-
age in a visible sump for periodic observation.  Other methods of visible
detection include standpipes and  wells.  Techniques  of measuring  ground
resistivity have been Developed and may also be applicable.
                                2-T

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     No reliable data are available on the long-term effects of FGC wastes
leachate on disposal site liner materials.  The permeability of plastic
liners is claimed to be zero but the durability of such liners in a dis-
posal site for FGC wastes has not been demonstrated.  Clay liners would
have more strength, ductility and durability than synthetic liner materials
because of inherent plasticity and buffering capacity, but clays possess
finite permeability.  Coefficients of permeability for clay soils usually
range from 10   cm/sec to  10"^  cm/sec, for homogeneous unweathered masses
of normally consolidated clay.  Preloading (with formation of cracks),
weathering or inclusion of coarser soil zones (silt lenses, for example)
can produce higher permeabilities in clay masses.  FGC wastes tend to be
more permeable than clay soils, but the long-term permeability of fixed
wastes may be as low as that of some clays.  Tests on unfixed wastes have
not been reliable in that sample preparation has not been appropriate in
some studies, while in other studies inappropriate testing methods have
                                                         — "^             —ft
been used.  Permeability test results have varied from 10   cm/sec to 10
cm/sec or lower (10   cm/sec is slightly more than one foot per year) .
Reliable data on wastes permeability are needed.
     At present, two important studies are  ongoing and may yield useful
results:
      a.  The U.S. Army Corps of Engineers Waterways Experiment Station
          (WES) is conducting a program to:  (1) determine the compati-
          bility of 18 liner materials with flue gas cleaning  (FGC) wastes
          and associated liquors and leachates;  (2) estimate the length of
          life for the liners; and  (3) assess the economics involved with
          purchase and placement (including disposal area construction)
          of various liner materials.  The liners that WES is  testing
          include:
          •  Admixture types  (cement,  lime, fly  ash),
          •  Prefabricated  liner membranes  (polymer, neoprene
             coated, etc.),  and
          •  Spray-on  types  (polyvinyl acetate,  latex, asphalt,
             cement, etc.).
          Results  of this  investigation  are  likely  to  be  available in 1979.
                                   2-39

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      b.  In 1978 EPRI initiated a program to evaluate leachate control
          and monitoring systems for solid waste disposal facilities.
          The objective is to evaluate liner materials for utility solid
          wastes.  This 36-month program which will be underway in 1979
          may yield substantial technical data on a number of liner
          materials.
Leaching from Ponds
     The extent of leaching of pollutants from disposal ponds is dependent
on several factors:  the hydrostatic head in the pond, which forces per-
colation through the pond bottom; the nature of the waste—primarily the
permeability and the solubility of contaminants it contains; and finally,
the characteristics of the soil beneath the pond.  At present, monitoring
wells exist in some of the FGC waste disposal ponds including large ones
like Bruce Mansfield.  However, for the better designed systems, adequate
time has not elapsed for meaningful data to be available at present.
Efforts are continuing in this field, and additional insight on field
site leaching is likely to be available in the future.
     EPA recently announced [21] that a major project of characterization
and environmental monitoring of full-scale utility disposal sites for
regulation development will be undertaken.  This effort will cover
monitoring of about 16 sites to obtain background data and information
to promulgate guidelines or regulations for management of FGC wastes
from coal-fired plants.  This 24-month project is expected to be underway
later in 1979.
     EPRI is sponsoring a program of monitoring the waste disposal site
at the Conesville plant of Columbus & Southern Ohio Power Company.  This
study, which will be underway by late 1979, will be conducted by Michael
Baker, Inc. and Battelle Columbus Laboratories.
     The above two studies are expected to provide substantial data on
leaching from ponds and other modes of FGC waste disposal.  Proposed
RCRA guidelines  [8] provide some guidelines on appropriate impoundment
design.
                                   2-40

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2.2.2  Dry Disposal
2.2.2.1  Description of Practice
     Dry disposal methods may involve any one of the following modes:
     •  Dry collection and direct disposal of coal ash and,
        in the future, dry sorbent FGD wastes,
     •  Interim ponding followed by excavation and landfilling,
     •  Mechanical dewatering and direct landfilling of FGC wastes,
     •  Blending with fly ash and direct landfilling of FGD wastes,  and
     •  Stabilization through the use of additives (non-proprietary  or
        otherwise) prior to landfilling.
     Operation of a dry disposal system usually involves up to four
basic steps:
     •  Collection/storage,
     •  Processing (dewatering, ash blending, stabilization, etc.),
     •  Transfer/storage/transport, and
     •  Placement and compaction.
The exact nature of a particular operation will depend primarily upon
the type of waste and the location of the disposal site.  Where disposal
sites are at some distance from the power plant (or waste processing
plant), transport of dry, dewatered, or processed waste is usually
accomplished by open, rear-dump trucks although in at least one case,
a dedicated rail-haul system is being used.   Interfacing a trucking
operation with waste production and disposal  frequently requires waste
transfer/storage systems, especially at the power plant (or processing
plant).   In the simplest  cases, this can  involve directly  filling of
trucks with discharged wastes via feeder  chutes or hopper bins  (although
provisions for emergency  waste  storage  areas  would be required).  This
approach  frequently is used  in  dry ash  disposal and some codisposal
operations.   In some  cases,  though, particularly  for FGD/ash  codisposal
and disposal  of stabilized wastes, it is  necessary to provide  interim
storage piles from which  the trucks are  loaded with front-end  loaders.
This  usually  requires  use of stacking conveyors.
                                 2-41

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     Where the disposal site is adjacent  to  the power plant,  the  trucking
of  the wastes can be minimized or possibly eliminated by  locating the  FGC
waste dewatering or processing plant at the  disposal site.  Stacking con-
veyors can then be used to move the wastes into the disposal  areas and
dozers and earth-moving equipment used to spread  and compact  the  wastes.
This is usually practical only for relatively  small disposal  operations.
     In general, operations at the landfill  area  involve  dumping,  spreading
and compaction.  Usually, only small sections  are worked  at any one time.
The wastes are layered in one- to three-foot  lifts with  spreading  and
compaction most commonly accomplished using  dozers.  In some  cases, fly
ash (and bottom ash) and FGD waste can be codisposed without  prior
blending.  In such operations, the ash and FGD wastes would be placed
in alternate layers.
Dry Disposal of Ash
     Coal ash (fly ash and, if necessary, bottom  ash although the latter
practice is not common) can be handled in a  dry state.  In such cases,
the ash is conveyed pneumatically from the electrostatic  precipitator
or bag filter to storage silos for intermittent transfer  for  disposal.
     Storage silos may be of carbon steel or hollow concrete  stave
construction.  Flat bottom silos are equipped  with aeration stones or
slides to fluidize dust and induce flow to the discharge  outlets.   Motor
driven blowers supply the fluidizing air.  Heaters may  be required to
prevent moisture from forming in the silo.   Silos are provided with bag
vent filters to prevent the discharge of  dust  along with  displaced air
as the silo is being filled.  Alternately, venting can  be provided by
a duct from the silo roof back to the precipitator inlet.  In some
cases, it may be necessary to install a low  pressure blower in the
vent duct to overcome losses which might  prevent  proper release of
air and cause pressure buildup  in the silo  or dropout  of fly ash  in
the duct.
     Fly ash normally is deposited in trucks or railroad  cars for
transport to a dump area.   In such esses, it is necessary to wet  the
dust to prevent it from blowing off conveyances during  transportation.
                                 2-42

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This is accomplished by means of conditioners which may be
horizontal or vertical rotary pug-mills.  These units require water under
pressures of about 80 psi.  Alternately, if ash is deposited close to the
plant area, it may be mixed with water at the vacuum producer part of the
handling system.
     The wetted coal ash  is deposited in the fill site and spread by
dozers in small lifts 0.3 to 1 meter  (about 3 feet) and compacted by
wide track dozers or heavy rollers.  When and where needed, water
trucks are employed during disposal operations at the site to control
fugitive dust.  The lifts are built up  to a total ultimate fill height
which will be site specific but which may range from 9 meters (about
30 feet) to over 25 meters (over 82 feet).
     In the future, disposal of dry sorbent FGD wastes is expected to
follow analogous operations.  Dry sorbent wastes are expected to be
fine, dry solids similar  to fly ash (dry sorbent wastes may  contain  FGD
wastes and fly ash for simultaneous removal will be practiced).
Interim Ponding
     In this approach, the FGC waste  is settled in storage ponds and
the supernate is recycled to process  or otherwise lost through evapor-
ation.  The pond may be reclaimed or, when the material is a moist solid,
may be excavated and landfilled in a  permanent site.  This method has been
used for disposal of sluiced ash from dry collectors and  in  at least some
cases for disposal of wastes from wet particulate scrubbing  systems  [6],
The interim ponding/excavation method is most applicable  in  arid regions;
it will  find  only limited use  for FGC waste  disposal in the  future.
Examples of interim ponding of FGC wastes are at  the Colstrip plant  of
Montana  Power and the  Cholla plant of Arizona Public Service.  The Four
Corners  plant of Arizona  Public  Services employs  interim  ponding  for
coal ash.
                                    i
Mechanical Dewatering  and Landfilling
     Mechanical dewatering methods, including vacuum filtration or
 centrifugation, may remove  enough  water from FGC wastes to allow
 direct  landfill disposal without additional processing (e.g., ash
                                2-43

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blending or stabilization.  This method of disposal is  applicable
to:
     •  Sluiced fly ash from dry collection systems where  the ash
        is dewatered in settling/decantation bins,
     •  FGD wastes from systems producing sulfate-rich  wastes,
     •  FGD wastes from systems employing forced oxidation to
        produce gypsum, and
     •  FGD wastes from dual alkali systems, especially those
        employing simultaneous fly ash and SC>2 control  (these
        wastes are sometimes more readily dewatered than sulfite-
        rich wastes from conventional direct lime or  limestone
        scrubbing systems)  [22].
An example of such a system is installed at the Caterpillar Engine
Plant at Mossville, Illinois [9].  In this 56 MW unit burning 2-1/2% S
coal, an FMC dual alkali system employing sodium carbonate/hydrated
lime produces a cake of 50-70% solids in vacuum filters; the cake is
placed directly in a landfill.
     Improvements in dewatering behavior and crystal morphology through
control of scrubber operation may make this method more applicable,  A
typical generic flowsheet for sulfate-rich (or gypsum)  waste is shown
in Figure 2.8.
Blending with Fly Ash
     Usually it is difficult and expensive to dewater FGD wastes,
particularly sulfite-rich or mixed sulfate/sulfite wastes.  An alter-
native to produce a moist cake suitable for landfilling is to dewater
to some extent and then mix the dewatered waste with fly ash[22,23] or
soil [24] to produce a mixture with lower moisture content than the
dewatered waste alone and which can be more readily handled.  A typical
flowsheet of such a blending scheme is shown in Figure  2.9.  Care is
required in designing the system, because the addition  of fly ash in the
dry form may lower the moisture content below that needed for optimum
compaction in the landfill.  The reactivity of the ash  also needs to
be considered in system design.
                                2-44

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NJ
            TO
         LIMESTONE
         GRINDING
         AND  S02
        ABSORPTION
          AREAS
         FROM S02
        ABSORPTION —-»
          AREAS
                         PUMP
                                     THICKENER
                                     OVERFLOW
                                       TANK
                                                          PUMP
                                                                          VACUUM
                                                                          PUMP
                                                                                       CONVEYOR  LQADING p|LE
                                                                                  FILTRATE
                                                                                  RECEIVER
                                                                       PUMP
         Source:   [23]
                             Figure 2.8  Typical Landfill  Scheme for Sulfate-Rich or Gypsum Wastes

-------
ro
•c-
           TO  LIMESTONE
           GRINIDNG AND
           S02 ABSORPTION
               AREAS
             FROM SO?
         ABSORPTION AREAS
                   PUMP
                               THICKENER
                               OVERFLOW
                                 TANK
                                               BLOWER
                                                         RHEUMATIC
                                                         CONVEYOR
     LIME
    STORAGE
     SILO
RAKE
                                                   PUMP
                                                                                                       LOADING PILE
                                                                 PUMP
          Source:   [23]
                                        Figure 2.9  Untreated Waste Fly Ash Blending

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Some scrubber vendors like Combustion Engineering [25], Research
Cottrell [26], and others are offering assistance in such design and
construction.
     Among the systems employing blending with fly ash is the Martins
Lake Station of Texas Utilities (two 795-MW lignite-fired boilers).
In this system, dewatering of the thickener underflow is accomplished
in centrifuges followed by blending with dry fly ash to produce a mixture
that can be handled for disposal.   The solids content of the mixture is
85% and permeability is reported to be 10   to 10~° cm/sec.  The wastes
are returned via a dedicated rail-haul system to the surface mine for
disposal.  At the mine, the wastes are dumped directly from the rail cars
and compacted.  As disposal progresses, the rail tracks are moved to
new areas of the mine.
Co-Disposal of Ash and FGD Wastes
     In an engineering context, the advantages of co-disposal seem  to
outweigh the disadvantages.  It may be easier to handle the sludge-ash
mix than to handle (transport, place, compact, etc.) waste or ash alone.
Fill construction would be easier using one material rather than two at
the same site  (mixed wastes versus layers of waste between ash) and
using one material in one fill rather than two separate fills,  at the
same site or at separate sites.  The mix of ash and wastes  (sludge)
should be less compressible and stronger than wastes alone, and less
subject to erosion than ash alone.  The mix of ash and wastes may be
self-hardening or it may require less fixative in a mixed  fill  than in
separate fills.
     A possible disadvantage could be an increase in permeability  (ash-
waste mix versus waste alone) with potential  for more  infiltration  and
leaching.  Another disadvantage is that the mix  could  be more difficult
to  transport  than is ash alone  (but easier than waste  alone,  at the
same solids  content).
Stabilization  Additives
     In  this method  of dry disposal,  lime  and fly  ash  or  other
stabilization  additives  are  added  to  dewatered wastes  prior to
                                  2-47

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disposal.  A generic flowsheet of this scheme is shown in Figure 2.10
based on descriptions of the IUCS stabilization process.
     In a stabilization process, cementitious additives produce pozzolanic
reactions that result in increased structural integrity in the wastes.
This chemical process continues after placement.  Typically, for dry
impoundment type of disposal, the wastes are thickened and dewatered
to a high solids content and blended with fly ash and lime, thus forming
a material with cementitious properties.  This material is transported
to the disposal site where it is spread on the ground in 0.3 to 1 meter
(1 foot to 3 foot) lifts and compacted by wide track dozers, heavy
rollers or other equipment.  Layering proceeds in 0.3 to 1 meter
lifts in segments of the site.  The ultimate height of a disposal fill
is site specific but may be as high as 25 meters (82 feet) or more.
A properly designed and operated dry impoundment system employing
stabilized wastes may enhance the value of the disposal site after
termination or at least permit post operational use.
     An example of the application of waste stabilization and dry
impoundment is the system at the Conesville Station of Columbus & Southern
Ohio.  The Conesville generating station is a mine-mouth power plant
located on the Muskingum River near Coshocton, Ohio.  The power plant
consists of six high sulfur, coal-fired boilers with high efficiency
electrostatic precipitators for particulate control, totaling about
2,000 MW of generating capacity.  Two boilers (Units 5 and 6), each with
capacity of about 400 MW, are equipped with direct lime scrubbing systems
for SO  control.  The FGD systems (by the Mr Correction Division of UOP)
for each boiler consist of two 200-MW TCA (turbulent contact absorber)
scrubbing modules which utilize thiosorbic lime as the scrubbing alkali.
Each pair of scrubber modules has a separate thickener for initial
dewatering of the waste solids.  The waste calcium-sulfur salts
thickened to 25-35% solids (35% solids design) are pumped to the
waste processing plant designed by IUCS for further dewatering and
stabilization by admixture with fly ash and lime.  The stabilized
wastes are then disposed of in a section of the existing ash pond
                                 2-48

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K>
I
.e-
          TO LIMESTONE
          GRINIDNG AND

         S02 ABSORPTION
             AREAS
           FROM SOa
        ABSORPTION AREAS
                 PUMP
                                                                                                   LOADING PILE
                                                             PUMP
       Source:   Description of the IUCS  Stabilization Process [26]

                               Figure 2.10   FGC  Waste Disposal Using a Stabilization Process*

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 adjacent  to  the  plant.   The  disposal  operation  is  essentially a dry
 impoundment  using  standard earth-moving equipment.  Figure 2.11 shows
 an  outline of  the  process.   It  should be noted  that this system incor-
 porates essentially  100% redundancy of all major equipment which would
 not normally be  required for most systems.
 2.2.2.2   Engineering Considerations in Dry Disposal
     Detailed  design of  FGC waste treatment and dry disposal operations
 is  site and  system specific.  However, some broad  engineering considera-
 tions are discussed  below to aid in defining environmental impact issues.
 These considerations are also broadly valid for mine disposal.
 Physical  Stability
     Physical  instability is a  potential problem for all FGC wastes,
 including stabilized wastes.  Geometric factors such as height and slope
 angle in a waste/ash fill are interrelated; stability depends on the
 combination  of fill height, slope angle, wastes density, degree of
 saturation,  effective cohesion, effective angle of shearing resistance,
 and behavior during shearing (dilatant versus densifying).  For a given
 material, safe fill height decreases with increasing slope angle.  For
 proper design, data are  required in which maximum safe fill height is
 related to slope angle and soil shearing behavior.  Such relationships
 have not been developed  yet for FGC wastes because adequate data from
 proper tests (triaxial compression tests on consolidated samples with
 measurement  of porewater  pressures) have not been available.
     Underlying materials may lead to instability of a waste deposit if
 the stresses in those matirials exceed the strength of the materials
 under those  loading conditions; i.e. , failure may occur because of the
weakness of  the underlying strata (a. basal failure in geotechnical
 terminology).  Weak compressible soils would be potential problem
materials in this context (e.g., normally consolidated clays).
     Erosion of cover materials could be important.  If a relatively
 tight (low permeability) cover soil or seal layer were removed through
erosion and if more pervious wastes we exposed by this erosion, infil-
tration of precipitation or surface runoii into the wastes deposit could
                                  2-50

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            50TPH   PNEUMATIC
Ni
I
TO POND


TO SCRUBBER
                       FILTERS
f
TER

*
FILTER


               TO
              POND
                                                                     800GPM
                            FILTRATE
                                                                                       800-
                                                                                       8000
                                                                                       PPH
                  LIME TRUCK
                  UNLOADING
                  STATION
                                                                                                     KEY

                                                                                                    — CONVEYOR
                                                                                                    — PIPE
                                                                                                    • SCREW FEEDER
                                                                                                    G-GALLON
                                                                                                    T-SHORT TON
                                              TO STACKERS


              Source:   Arthur D. Little,  Inc.


                                      Figure 2.11   Schematic of IUCS "Stabilization" Process at Conesville

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be  increased.   Increased infiltration  could  lead to saturation of wastes
previously unsaturated and could cause generation of significant porewater
pressures.   Saturation would  increase  the weight of the wastes and pore-
water pressure  generation would decrease effective stress thus decreasing
the strength of the wastes deposit.  Both factors tend to lead to sliding/
slumping.  In any case, erosion of cover materials has been studied
extensively  and is a function of material credibility, which depends
principally  on particle sizes, particle shape and interparticle cohesion.
     On the  other hand, placement of cover material over a wastes deposit
may cause a  mass failure if the added load (surcharge) exceeds the bearing
capacity of  the filled material.  This could occur with surcharge on a
wastes slope or with concentrated loads due to inequalities in surcharge
loading.
Compaction
     Instability problems may be ameliorated by compaction since compaction
may produce  several changes:   voids may be eliminated (between chunks, not
between individual particles); wastes density may be increased; particles
moved closer together may be bonded more effectively in stabilization
reactions; and effective stress and residual total stress levels may be
increased.   If the wastes resemble sandy soils, an increase in density
during compaction may create an important increase in angle of shearing
resistance.  Compressibility also would be decreased by an increase in
density.  Compaction of natural soils tends to create suction in the water
between soil particles if the soil is unsaturated and tends to swell after
removal of the compaction pressure.  This effect probably would not be as
important for sand-like wastes (e.g., some sulfate-rich wastes) as for
more fine-grained platy-particle wastes.   The increase in density would
probably yield greater strength since the fine-grained wastes would be
changed in shearing behavior to more dilatant behavior.   Saturation of
unsaturated  compacted wastes  would eliminate the beneficial suction in
the porewater and decrease the strength of the wastes,  but the benefit
of increased density could be significant.
                                 2-52

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     Physical factors such as compaction effects also may alter with time.
If the wastes are saturated, with low solids content, consolidation may
occur with significant increase in solids content, stiffness and strength;
this may be significant for thickener underflow consistencies.  Increase
in density (and consequent increase in strength) created by compaction
should not disappear, but long-term saturation can potentially dissipate
suction effects (and consequent increase in strength) created during com-
paction.  Dissipation of suction effects would have most effect near the
surface of a waste deposit because, at depth, overburden pressures could
create interparticle stresses equal to the interparticle stresses created
by suction in the porewater.
     The stability of settled sulfite wastes  under compaction equipment
will vary with the solids content of the wastes (assuming no chemical
stabilization of wastes) and probably with the type of compaction equip-
ment (static, rubber-tired, steel roller, sheepsfoot, vibratory, etc.).
Experience at the Scholz plant indicated it was necessary to dewater
waste to 70-75% solids content before compaction could be accomplished.
Sulfite wastes tested to date may be incapable of supporting compaction
equipment of any kind unless such high solids contents are achieved first.
Liquefaction may be a more serious threat in sulfate wastes, especially
under vibratory loading.  Field tests are required for an answer to
this question.
2.2.2.3  Climate
     Climate could affect the stability of a wastes deposit in several
ways.  The total amount of rainfall and the intensity of rainfall both
affect surface erosion, but these factors influence the rate of erosion;
i.e., erodible materials will erode if wind and rain :act on them but in-
crease in amount/duration and intensity of wind and rain will increase
the  rate of  surface  erosion.  Of  course, as mentioned above,  infiltration
of water into wastes deposits can lead  to saturation, decrease  in  apparent
strength, and, possibly,  to  failure.  This would  be most likely to occur
with wastes  of highest  permeability  in  an unsaturated condition, but  it
could occur  in any improperly designed  FGC waste  deposit.
                                  2-53

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     Freeze-thaw  cycles  could have  several effects.   Stabilization reactions
 could be  retarded,  disrupted or destroyed by  an episode of  freezing soon
 after mixing and  placement.  Freezing  could produce cracks  in the near-
 surface layers  of a wastes deposit  (frost polygon behavior).  Cracks in
 the wastes deposit  could yield greater mass permeability and infiltration
 rate even though  waste blocks between  cracks  had been compressed and even
 dewatered.  In  a  fill created in  layers over  a number of years, freeze-
 thaw effects on temporarily exposed faces and surfaces could produce
 horizontal layers through the finished deposit, with high "crack" per-
 meability in such layers (this type of structure is common  in masses of
 alluvium  along  large rivers).  Increased permeability could lead to more
 formation of leachate.   On the other hand, freeze-thaw cycles, may be
 effective at some sites  in dewatering  surface layers.  The problems of
 crack formation could be ameliorated by compaction of the thawed material
 after maximum possible evaporative  dewatering and before placement of
 additional thickness of  wastes.  Freeze-thaw  effects require investigation.
 2.2.2.4   System Design and Post-closure Land  Use
     Often it is  difficult to specify  the ultimate use of the land on
which FGC waste disposal is planned or practiced.  However, it is impor-
 tant to recognize engineering constraints on  post-closure land use.  Post-
 closure land use would tend to be limited by  nature of the loads created
 or by the sensitive nature of the structures  or facilities built on the
wastes fill.  For example,  placement of some  sort of fill in a uniform
 layer over the entire waste deposit  should be feasible, but imposition
 of concentrated loads (e.g., footings  in a building) may cause bearing
 failure with rapid plunging of the  loaded element into the wastes.   Vibra-
 tory loads as from machinery foundations could have disastrous effects on
unfixed wastes.   The rate of application of load also is extremely impor-
tant—loads applied slowly  may allow consolidation of the wastes during
loading, yielding higher strength than for material loaded rapidly.
Rapid application of load increases shearing stresses and may decrease
shearing resistance if the  structure of -the wastes is disturbed (collapse
or remolding).
                                 2-54

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     The nature of the supported use also is important.   A park built  on
cover soil over FGC wastes would not be affected seriously by wastes
settlement.  A low, flexible structure like a warehouse  would e:;ert low
loads and could tolerate greater total and differential  settlements than
could a structure like a boiler-turbine-generator complex.
     Uses of adjacent land could be restricted by access or geometry
limitations (e.g., difficulty in building access roads across wastes
deposits) or by consideration of possible failure of wastes retention
structure, or by pollution effects (losing the use of groundwater through
pollution by leachate from FGC wastes).

     In the choice of a site for disposal, it is well to note that any
land could be used for wastes disposal, with proper engineering design,
but the choice to dispose of FGC wastes at a given site might be based
on the concept of "best and highest sequential use" with all technical,
economic and environmental factors considered.  Obviously, waste land
areas with irregular topography (for ease of containment and a source of
cover soil) and highly impervious subsoils would be ideal.  Valuable,
flat or uniformly sloping areas with highly pervious soils and scarce,
pure (thus valuable) groundwater would be poor locations  for disposal
sites.   Wetlands would be a poor choice.
Runoff-Related Considerations
     To limit water losses by runoff from a wastes deposit, grading and
drainage during construction could be employed as in any other construc-
tion activity.  After completion of the deposit, a cover  soil  is chosen
to limit infiltration; a soil consisting of a mixture of  clay, silt and
sand fractions is better for this purpose than a material  of uniform
grain size, no matter what  the  average  grain size.  Water  recycle  could
certainly  be employed; surface  runoff  caught in  temporary retention basins
could be piped back  to the  FGC  system.
     To  limit water  losses  by leachate, water  infiltration into  the  fill
is minimized by  the  techniques  mentioned  above,  the water content  of  the
wastes  is  minimized  by dewatering  prior to  placement  and a seal layer is
prepared  in the  bottom of  the fill area prior  to wastes placement.  Below
                                2-55

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the bottom seal, a pervious drainage layer could be constructed to surround
the wastes deposit; this pervious layer would collect leachate and carry
it to a central sump.  From the sump, the leachate could be recycled to
the scrubber (if feasible) or it could be sprayed on the surface of the
fill to utilize evaporation as a means to decrease leachate quantity, or
it could be piped to a treatment plant.  If the natural subsoils at the
disposal site were very pervious, a seal layer could be required below the
drainage layer.
2.2.2.5  Design of Landfill
     Landfill design can be based on many configurations.   Three broad
generic configurations are shown in Figure 2.12.  Some pertinent comments
are:
     •  The structurally simplest form of landfill which may be
        utilized with level terrain is the heaped landfill.  Even
        though this design is simplest in terms of site preparation
        and may offer advantages in terms of slope stability and
        groundwater pollution, it is often aesthetically undesirable.
     •  Side hill design is advantageous and often utilized in
        areas of hilly terrain where the natural slope of one
        side of a hill or valley may provide containment.   The
        side hill landfill must be prepared properly to ensure
        stability.
     •  The valley fill design, which is the most common type of
        landfill used, is often the most complex in terms  of
        original site preparation.   Natural valleys or ravines
        are often sources of surface water runoff and may  have
        springs along side slopes.   In such cases, surface water
        and groundwater control is  usually necessary to avoid
        accumulation of water and the development of a leachate
        problem.  Drainage must be  provided and, in some cases,
        hydrologic modifications to divert water flow around
        the landfill are necessary.
                                2-56

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                                                  Side Hill Landfill
                                                   Heaped Lardfill
                                                   Configuration
                                             ^^^^
                                                    Valley Fill
                                                    Disposal
                                                    Configuration
                                             .v«.<<*W«.&J3 'i&ISETOTSS?
Source:   [7]
                   Figure 2.12  General Landfill Designs
                                    2-57

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     Design of a managed operation like a landfill requires adequate
data on the engineering properties of the waste and of the soils at
the site.  Laboratory tests give indications of the shearing behavior,
strength and compressibility of wastes.  To maximize stability, the
factor of safety is normally set between 1.0 and 3.0, with the value
chosen depending on the consequences of failure.  Then, using appro-
priate values of shear strength parameters obtained in laboratory tests,
the designer would obtain combinations of fill height and slope angle
corresponding to the selected factor of safety.  The steeper the slope
angle, the lower the maximum safe fill height.  No absolute maxima or -
minima exist.  Also, underlying strata properties and topography influence
this analysis.  Disposal techniques influence stresses, porewater pressures
and shear strength parameters.  A proper design is necessarily site specific
Proper landfill design requires control of both leachate movement and run-
off.  Stabilization processes reduce permeability of the waste.  To achieve
full environmental benefits from such processing and compaction of the
wastes, proper design of the landfill to control runoff is necessary.
Conventional runoff control practice in the construction industry con-
sists of retaining runoff in temporary retention basins to settle sus-
pended solids prior to discharge or other use.
     For a brief overview of the data base on land disposal of FGC
wastes, the reader is referred to [28],
                                 2-58

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2.2.3  Mine Disposal of FGC Wastes
2.2.3.1  Introduction
     While mines have been used for the disposal of coal ash and mine
tailings for many years, they are only now being seriously considered for
the disposal of FGC wastes.  There are currently over 15,000 mines through-
out the United States which together produce over 0.5 billion tons of
coal and 2.5 billion tons of metallic and nonmetallic minerals each year.
About one-third of the mines individually produce over 100,000 tons
annually, mines large enough to handle the quantity of FGC wastes pro-
duced by a normal utility boiler.  Such mines represent an enormous
capacity for the disposal of these wastes.
     However, much of the  capacity is clearly not suitable  for FGC waste
disposal.  The method of mining, for example, can preclude practical waste
disposal operations.  Underground mining which employs caving or cut-and-
fill techniques leave little available void for waste disposal.  In open-pit
mining, overburden is often removed from the mine area, and the mineral  is
mined downward  from  the surface  in benches, or the mining operation may
follow the ore  strata downdip  from its surface outcrop, which requires
that the area mined  be  left open for access of haulage vehicles.
     The  four different categories of mines which  appear  to provide  the
greatest potential  for  the disposal of  large quantities of  FGC  waste,  at
least with  regard  to the  overall technical feasibility  are  [29]:
     •   Surface coal mines,
     •   Underground room-and-pillar  coal  mines,
     •   Underground room-and-pillar  limestone mines, and
     •   Underground room-and-pillar  lead/zinc mines.
     Of  the four  categories of mines  noted above,  coal  mines,  and in
particular  interior and western surface area coal  mines,  are  the most
likely  candidates  for waste disposal.   Coal mines  offer the greatest
capacity for disposal,  and they are  frequently  tied directly to power
plants.   In fact,  many new coal-fired power plants are  "mine-mouth"
 (located adj.acent  to the  mine  within  a few miles)  and the mine provides
a dedicated coal  supply.   Since the  quantity (volume)  of  FGC wastes  pro-
duced  is considerably less than the  amount of  coal burned,  such mines
                                    2-59

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 usually would have  the capacity for disposal throughout  the  life  of  the
 power plant.
 2.2.3.2  Surface Coal Mines
 Description of Mining Operations
      The conventional method for surface  mining of  coal  is called "strip
 mining."  Mining practice in strip  coal mines mostly  involves  the use  of
 draglines and shovels for overburden removal, smaller shovels  and front-end
 loaders for coal digging, and trucks for  coal hauling.  In a few cases,
 scrapers and  bucket wheel excavators are  used in softer  overburdens.
 However, in strip coal mines where  the overburden is  relatively soft or
 can be loosened somewhat by gentle  blasting, the dragline is the pre~
 ferred machine to use for digging and casting the overburden.   If the
 formations over the coal seam are hard and compact, and  tend to break
 into blocky or hard-to-handle aggregates  of blocky  chunks, then large
 shovels are preferred.   Now, more than half the surface  mining of coal in
 the United States involves draglines rather than shovels.
      There are basically two different types of strip mining.   For
 relatively flat or level areas, coal is mined by "area stripping."  Area
 stripping is  commonplace in the Western and Interior  coal mining regions.
 On steep slopes, the method used is called "contour stripping."  Such steep
 slope conditions prevail in the Eastern coal region.
      A typical area strip  mining operation  involving  the use of a shovel
 for  removal of the  overburden  is  shown in Figure  2.13.  In a typical case
 the  shovel, sitting on  the floor of  the pit  on  top  of the unmined coal
 removes  the overburden  and dumps  it  to the  side in  the previous cut  from
 which the  coal has  been extracted,  forming what is  called a "spoil bank."
 The  coal extraction operation  then advances  behind  the shovel.  This
 may  involve blasting prior to  digging and loading the coal onto trucks
 using smaller  shovels and/or front-end loaders.
      The area  of  the spoil banks  is  reclaimed using dozers,  graders, and
 standard earth-moving equipment.  Reclamation usually involves flattening
 of the spoil banks  followed by covering with  a layer  of topsoil and
 seeding.  The  reclamation  process usually progresses  concurrent with the
mining operation, but at two or  three spoil banks removed from the exposed

                                  2-60

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NJ
1
CTv
                                                                                                 ,  f
                                                                                    Reclaimed
                                                                                      Area
                                                   Stripping Bench	-—
           Source:  [29]
                                  Figure 2.13  Area Strip Mining With Concurrent Reclamation

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pit to ensure stability  of the spoil banks adjacent to the working areas.
The topsoil used in the reclamation process can either be that originally
present or soil imported from nearby areas (or a combination of both).
The process of removing or obtaining topsoil and storing it adds another
step to the mining operation and must be coordinated with the other
activities.  To provide some perspective on strip mines in various
regions, one may note  [291:

     •  Interior surface mines produce 1.5 to 2.0 million tons of
        coal annually  and  seams vary from 0.8 to 2.1 meters  (2-1/2
        to 7 ft) thick.  Width of  the pit is often 15  to 30 meters
        (50 to 100 ft) while a typical length is 0.6 to 1.2 kilo-
        meters (1-2 miles).
     •  Western surface mines are  usually larger.  Seams may be
        up to 30 meters (100 ft) thick.

     Contour strip mining  is practiced almost exclusively in the Eastern
region  (particularly Appalachia).  In conventional contour stripping,
spoil or waste is stripped and dumped downhill from the cut.  This
frequently causes water runoff erosion problems with damage to property
holders below.  Reclaiming can then be more difficult  since waste has
to be moved back up-hill again.  A variation in this conventional
approach, known as the "block" ("haulback") method of mining, solves
many of these problems.  In the haulback method, spoil is moved
horizontally from the working area to the mined-out cut.  This requires
mobile equipment such as bulldozers, scrapers, front-end loaders, and
trucks.  The production from individual eastern mines is considerably
less.  Eastern surface contour mine production ranges from 0.01 to
1.5 million tons per year.  Coal seam thicknesses vary from 0.8 to about
2.1 meters (about 2-1/2 to 7 ft) and are usually horizontal.  Contour
stripping method of mining is less amenable to FGC waste disposal than
area stripping method described earlier.
                                 2-62

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FGC Waste Placement
     In general, inactive surface mines may be less promising
than active mines for FGC waste disposal.  Unreclaimed surface mines can
be used for disposal of wastes between remaining spoil banks, and these
may offer suitable sites for disposal.  However, because of recent surface
mine reclamation legislation, the number of sites and total capacity
for wastes available in the future may be limited.
     In active surface mines, there are basically three options for the
placement of FGC wastes:
     •  In the working pit, following coal extraction and prior to return
        of overburden,
     •  In the spoil banks, often return of overburden but prior to
        reclamation, and
     •  Mixed with or sandwiched between layers of overburden.
     In any disposal operation in an active mine, though, the general over-
riding consideration is that disposal should cause minimal disruption of
mining or reclamation activities.  This provides a number of constraints
on the disposal system.
     First, the amount (volume) of FGC waste disposed of in any surface mine
 should not exceed the amount of coal removed.   The objectives of strip
 mine reclamation include returning the mined terrain to topographic con-
 figurations similar to original terrains, and returning significantly more
 waste to a mine than the coal extracted could slow down the mining and
 reclamation activities.  In most cases, this does not really represent
 a constraint, since the wastes returned to the mine will be only those
 resulting from the coal removed.  The amount of FGC waste generated from
 the combustion of coal will be considerably less than the quantity (weight
 or volume) of coal removed.  Depending upon the type of coal, FGC system,
 and emission standards to be met, the volume of total waste  (ash plus
 calcium-sulfur solids) will vary from less than 10% of the coal burned to
 slightly over 50%.  With Western coals, which are relatively  low in sulfur,
 less than 20% is the  rule.  With higher sulfur Eastern and Interior coals,
 the total amount of wastes will typically run  30% or more.
                                  2-63

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    Second, the physical condition (consistency) of the wastes must be
amenable to ease of handling, transport, and placement using earth-moving
equipment with minimal potential impact of the mining operations.  For
pit-bottom disposal this means that the wastes at the time of placement
or immediately thereafter should have as a minimum the consistency of
a soil-like material with little or no liquefaction potential.  A slurry-
like material or a waste with a tendency to flow either when placed or
when overburden is dumped on top could present significant operational
problems or unacceptably high costs for containment measures.  A little
more leeway exists for disposal in V-notches (between spoil banks); however,
here again, soil-like materials or relatively cohesive materials that are
relatively easily handled and transported will result in the least cost
and minimal disruption of reclamation activites.  At the least, the wastes
must be well filtered (55% solids or higher), admixed with dry fly ash,
or treated.
    Finally, minimal use should be made  of existing mine equipment  for
transport and placement of the wastes at the mine.  Dedicated  equipment
is preferred and, in most cases, mandatory.  In almost all scenarios, waste
is most easily placed by truck dumping.  The use of coal trucks  for  this
purpose could lead to unacceptable delays in coal mining operations  due
to the additional time for waste loading and discharging (and  possibly
cleaning operations).  Furthermore, most large mines use large bottom-dump
trucks for coal haulage.  These are designed to carry as much  as 150 tons
of coal and are usually constructed of aluminum.  Not only might some types  of
FGC waste corrode the aluminum, but the bottom dumping of wastes would be im-
practical.  These trucks are not designed for ease of maneuvering, and operati
them (or any other equipment) on a freshly dumped layer of waste would be diffi
cult at best.  The type of truck used for transport and placement will
greatly affect the quantity of waste that can easily be disposed of.
    At present there are only two commercial operations involving mine
disposal of FGC wastes in surface coal mines—one at Texas Utilities
Martin Lake Station and the other at Square Butte's Milton R.  Young
Station (North Dakota).  Both stations fire lignite and involve returning
combined fly ash and calcium-sulfur solids from SC^ removal  to the  respective
                                  2-64

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mines.  The operation at the Milton R.  Young Power Station is currently
an EPA mine disposal demonstration project.   At this Baukol-Noonan
mine, both pit-bottom and spoil bank disposal are being practiced.
Pit-Bottom Disposal
     Pit-bottom dumping is probably uhe simplest, least disruptive
method of surface mine disposal.  Transpoi •  and placement of the wastes
is most easily accomplished using rear-dump  trucks.  Access to the pit
floors is usually good, since roads are maintained in relatively good
condition for coal mining and hauling equipment.  There is also usually
adequate time for waste placement between coal removal and overburden
replacement.
      Major  potential problems are  interference with coal removal  in
the working pit due to instability of adjacent spoil banks caused by the
underlying wastes, and the possible congestion in the working pit due to
the two-truck transport systems (one for coal and one for wastes).  Most
of these problems are avoidable by control of waste properties and
placement,  and proper scheduling of mining and disposal activities.
In some cases, it may be advisable to concentrate the waste dumping on
the side of the pit farthest from  the highwall  (against the newly created
spoil bank).  This will provide an open "buffer" region where no waste
exists when the next cut is taken  and the overburden dumped on the waste.
V-Notch or  Spoil Bank Disposal
      V-notch or spoil bank disposal, as with pit-bottom disposal, would
involve truck dumping and many  of  the same constraints with regard to
waste characteristics and disposal operations apply.  It involves somewhat
more  effort than pit-bottom disposal, since roads must be  cut into the
spoil banks at the base of the  vees to allow access by waste trucks.  This
can be relatively easily accomplished in  most cases with  standard dozers
and road grading equipment.
      While  it requires more effort, it may also offer  some advantages  in
that  the disposal is less likely  to directly impact the  coal  removal  operation.
There is less pit congestion,  less potential of creating spoil  bank  insta-
bility,  and generally  less  stringent scheduling requirements.   For  these
reasons, spoil bank  disposal may  often be preferred to pit-bottom disposal.
                                   2-65

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Mixing with Overburden
     Waste disposal operations can be adapted to allow mixing of the
waste and overburden.  This can be accomplished readily in contour strip
mines where haulback methods are used and in some Western mines where
overburden is handled by truck.  However, in many strip mines, mixing
waste and. overburden or sandwiching waste between layers of overburden
may require too much additional handling of materials as well as added
constraints on the dragline or shovel operation.  Thus, in most mines
this type of operation is not expected to be practical.
Overall Disposal System Implementation
     There are many possible disposal system configurations depending
upon the type of waste (filtered waste admixed with fly ash or treated),
distance between the power plant and mine, and the type of placement.
In general, though, the distance between the mine and power plant is the
overriding factor which dictates the amount of handling and the types of
transfer facilities required.
     For onsite (mine-mouth) disposal operations, truck transport of
wastes would probably be preferred.  In many cases it would be advanta-
geous for the fly ash/filter cake mixing system or waste treatment
operation to be tied directly to the truck transport system to minimize
double handling of material and minimal storage capacity for the wastes.
For offslte mine disposal where the mine is more than a few miles from
the power plant, rail haul of the wastes is a practical and economical
alternative.  Either the same train used to carry the coal or a dedicated
smaller train can be used to carry the waste to the mine.  If the coal
train is used or if the distance between the power plant and the mine is
such that the turn-around tim^. on a dedicated train is long, then waste
transfer/storage areas at both the mine and the power plant would
probably be required.
2.2.4    Underground Mine Disposal
     Underground mine disposal of FGC wastes is not currently practiced.
However, there have been a number of studies evaluating the potential for
underground mine disposal including work by Radian [75] for the U.S. Bureau
                                 2-66

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of Mines, a study by Arthur D.  Little [29]  for the U.S.  EPA (IERL),  and
a study by Michael Baker Jr., Inc.  [76]  for the U.S.  EPA (MERL).   These
indicate that such disposal operations are technically feasible  and can
be economically viable as well as environmentally acceptable.   In fact,
underground mine disposal may offer potential benefits in terms  of sub-
sidence control, fire prevention, and prevention of acid mine drainage.
Description of Mining Operations
     There are two basic underground coal mining methods:  room and pillar,
and longwall.  Underground coal mines are also often classified as slope,
drift, or shaft mines, depending upon the method of access rather than
the mining method used.
     Room and pillar mining involves removal of the coal in "rooms"
leaving "pillars" to support the roof.  Room and pillar coal extraction
can be "conventional" wherein the coal is extracted in a series of dis-
crete steps  (undercutting the coal, drilling, blasting, loading, and
shuttle car haulage to main haulage belts or rails) or "continuous"
where continuous mining machine cuts the coal, loads and delivers it to
shuttle cars (which really makes the system only semi-continuous) or to
conveyor belts for removal from the mine.  In most room and pillar systems
another important step is to place roof bolts for supports as the mining
proceeds.
     If the pillars are not robbed, the coal extraction is on the order
of 50%.  If geologic and roof conditions permit and if surface caving
can be allowed, the pillars can be robbed  (removed) as one retreats back
to the access opening, which can increase  extraction to 70-80%.   Complete
extraction through pillar robbing is not technically feasible.
     Longwall mining systems rely on  the controlled caving of the roof.
The system consists of a coal cutting machine, chain conveyor system,
and hydraulic movable roof support.  The operation of longwall coal
systems  is more nearly continuous  (when  they operate successfully)  than
room and pillar mining, with coal cutting, removal, and prop  advance
going on steadily.  When the props are advanced,  the unsupported roof
caves and leaves what  is known  as gob area.
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     Most U.S. coal mines using longwall techniques also produce coal
by room and pillar methods; hence, coal production from any mine is
rarely all from the longwall mining operation itself. Longwall mining
methods (including shortwall mining) cannot be used in all underground
coal mines in the United States.  Application of longwall operations
are limited to areas where the surface above can be disturbed and where
the coal to be mined occurs in configurations amenable to the longwall
layout.
FGC Waste Placement
     In general, old, inactive underground coal mines offer less promise
than active underground coal mines for FGC waste disposal.  Abandoned
mines are often caved and filled with groundwater of unknown flow patterns
caused by the hydrogeologic changes created by mining.  The voids are
difficult to find because of prior roof collapse as pillars deteriorate
and fail.  Even the initial open cavities prior to roof collapse are
difficult to delineate, as underground mining plans for abandoned mines
are generally not available.  Only in a few isolated instances, where
mine conditions are fairly well defined and where disposal of FGC wastes
can be justified as a method for limiting acid mine drainage formation
and/or to prevent further surface subsidence damage does disposal in
abandoned mines appear promising.
     Active underground coal mines (disposal in mined-out sections of
active mines), show considerably more technical promise.  However, waste
placement would still add complication and additional maneuvering to the
already difficult working conditions.  Also, many of the underground mines
utilizing a combination of both conventional room-and-pillar mining with
pillar robbing and/or longwall mining may limit the available capacity
for waste disposal or may require more than one disposal placement technique.
     There are basically three approaches that can be or have been employed:
pneumatic backfilling, hydraulic backfilling (or flushing), and mechanical
stowing.  These have been demonstrated or practiced in both the United
States and Europe for disposal of mine tailings or placement of fill
materials in underground mines.
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Pneumatic Backfilling
     Pneumatic backfilling simply involves blowing the material into the
mine void through a pipeline either from the surface, which enters the
void through boreholes in the roof, or from an underground station mounted
at the entrance to a voided area.  Practically speaking, pneumatic back-
filling would have to be done by blind injection,  that is, without the
aid of men underground during the backfill operation to direct the flow
of material and control the distribution.
    Pneumatic backfilling has been successfully used  for  the disposal of
fly ash  in  coal mines,  indicating that it may be feasible for  use with FGC
wastes.   In fact, pneumatic backfilling (stowing) may be  the only feasible
method for  waste  disposal in conjunction with longwall  mining  operations.
The obvious limitation  with regard to FGC waste disposal, though, is  that
the material must be dry and free-flowing.  Because of  the limited  experience
                                                      0
with pneumatic stowing  and the  limitations it places  on the form of the
waste material, it  is not anticipated that pneumatic  stowing will gain wide-
spread use  for waste disposal.
Hydraulic Backfilling
     There has been considerably more experience with hydraulic back-
filling both in the United States and Europe than with pneumatic stowing.
This method has been successfully used to return coarse mine tailings
from both .coal and metal mines to mine voids.
    In contrast to  pneumatic backfilling, hydraulic  backfilling can be
practically accomplished either  by controlled or blind  injection.   The
distribution of material achieved  depends upon the pressure head at the
pipeline, the solids  content of  the  slurry, the arrangement of the  dis-
charge piping, and  the  characteristics of the mine void (mine  layout, coal
bed slope,  etc.).   In some cases where there is sufficient slope of the
area being  filled,  it may not be necessary to install bulkheads to  block
out the  disposal  area to prevent flowing of the material  to the active
areas of the mine.   However, in  most operations utilizing mined-out portions
of an active mine it would have  to be assumed that  the  bulkheading  would  be
required, particularly  where the waste is introduced through  the boreholes
in the mine roof.
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     In hydraulic backfilling of FGC wastes the solids content of the waste
slurry will vary with the type of waste material.  In most cases it is
reasonable to assume that a slurry containing a minimum of 25-30% solids
could be piped into the mine void.  With this slurry concentration,
settling in the mine void can be expected, and provisions may need to be
made to pump out water/liquor runoff.  If dry wastes are slurried for
hydraulic backfilling (or thickened waste is diluted), then the collected
drainage could be recycled for slurrying the wastes.
     A wide variety of wastes can be handled, ranging from simple,
untreated calcium-sulfur solids generated from the removal of SCL to
mixtures of ash and calcium-sulfur wastes or even treated slurried material.
Treated material may offer some advantages in that once stored, in the
mine it will cure and harden, resulting in a relatively hard, monolithic
mass which would be resistent to flow and may also provide a small amount
of subsidence control.
Mechanical Stowing
     Mechanical stowing of wastes can be accomplished in active mines
using existing transport/conveyance equipment or equipment that can be
readily adapted for use in the mine.  Such operations would generally
not be economically attractive in comparison to hydraulic backfilling;
however, it may be appropriate for use in certain types of mines such
as underground limestone mines where there is ready access to mining
areas.  In fact, in limestone mines it may be possible to place wastes
via truckload delivery, since these mines have large, open rooms accessi-
ble from the surface.
Overall System Implementation
     Hydraulic backfilling of underground mines is most easily accomplished
at mine-mouth power plants or where the distance between the power plant
and mine is a few miles or less.  In such cases, wastes can be piped directly
to the mine and pumped down the mine borehole.   Piping of wastes for long
distances, though, can be a problem, particularly if stabilized wastes
are to be used.   Thus,  this may involve dewatering of the wastes, transport
and reslurrying prior to disposal, all of which would require considerable
rehandling and extra cost.
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     Where the power plant is located adjacent to the mine, the wastes
from the scrubber system can be first thickened to 20-35% solids and then
pumped to the mine and down the boreholes.   At the mine, drilling of
boreholes and construction of bulkheads across mine voids would be an
ongoing operation to provide new sites for the waste disposal.  An interim
storage tank may also be required for the wastes to handle periods of
disposal system interruptions.  As the waste materials settle, it will
probably be necessary to also pump out the decanted liquor and return
this to the scrubber system.
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2.3  Ocean Disposal
2.3.1  Overview
     Ocean disposal of FGC wastes is not practiced today.  However, if it
could be practiced under environmentally satisfactory conditions, it could
represent an important option, particularly in the Northeast where land
for disposal is limited.  For this and other reasons, EPA has been study-
ing the disposal of FGC wastes in the ocean [29],  At present, regulation
of dispersed ocean dumping of treated and untreated FGC waste falls under
the Marine Protection Research and Sanctuaries Act and is administered by
the Environmental Protection Agency.  The dumping would be required to
occur at EPA prescribed dumpsites under the following conditions:
     •  Mercury, cadmium content of the dumped materials would
        be no higher than 50% above that of background sediments
        at the dumpsite,
     •  Concentrates of the dumped material in the water column
        four hours after release would not exceed 1% of the 96-
        hour LC,-Q of the material to local sensitive species, and
     •  No feasible alternatives to ocean disposal are available.
     Stabilized, brick-like FGC waste may potentially be used to create
artificial fishing reefs with EPA concurrence.  Artificial fishing reefs
are not subject to ocean disposal criteria but FGC waste disposal may be
a special case.  At any rate, the issue has not been finally decided upon.
While ocean disposal of FGC waste is an option that is perhaps available
to throwaway system users with economic access to the ocean, new ocean dis-
posal initiatives are now discouraged by the regulatory agencies.  If cur-
rent studies on ocean disposal of FGC wastes indicate that environmentally
sound disposal is feasible, then the regulatory posture could change.
     There are two types of ocean environments for FGC waste disposal:
     •  Shallow ocean (on the continental shelf), and
     •  Deep ocean (off shelf).
Each area has a different ecology and may therefore be subject to differ-
ent considerations when evaluating environmental  impact.   That subject is
discussed further in Section 4.3 of this volume.
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2.3.2  Disposal Technology
     Technology for disposal of FGC wastes  in the ocean can  be  broadly
subdivided into:
     •  Transportation,  and
     •  Surveillance and monitoring.
The former is discussed  here, the latter i.  Section 5.3.2  of this  volume.
     Methods for ocean dumping are determined principally  by the nature
and form of the waste to be disposed of, and the disposal  site  in  relation
to the site of origin.  Consequently, the nature and form  of a  new waste,
unsuitable for an existing transport system might have to  be changed to
make it acceptable for use with the given transport system.
     There are currently a number of viable techniques for transporting
waste mixtures to offshore disposal sites.   Existing practical  technolo-
gies allow either (a) controlled dispersal of the sludge over a great
expanse of water or a sudden total dump; or (b) a continuous pipeline dis-
charge of the sludge.  These techniques would fall into the following
categories:
     •  Self-propelled hopper ship with throttled discharged dis-
        posal or with a sudden dump capability,
     •  Tow-barge transportation and controlled dispersal  over a
        great expanse of water or a sudden total bottom dump, and
     •  Submarine pipeline transportation and dispersal at a pre-
        selected offshore disposal site.
     All these  approaches are technically feasible systems which have been
utilized on  a full scale for other wastes.  Selection among them depends
upon both the characteristics of the waste to be dumped and any environ-
mental conditions and/or constraints that might exist.
Pipeline Transport
     For pumpable wastes, this method is mechanically simple.  Using an
ocean outfall,  FGC waste may be piped many miles to be  discharged  (usually)
through a section of  diffuser  conduit several  feet  above  the bottom.   Typ-
ical operation  is  fairly simple, consisting  of monitoring and  maintenance
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of the pump, pipeline, and diffuser.  Depending on operation of the solids
removal process and resulting effluent concentration, active regulation
of pump rate may be necessary.  When waste production is small enough to
permit intermittent operation, the outfall may require flushing with
fresh or reclaimed water after each discharge period to prevent sedimen-
tation and possible clogging of the diffuser.  Underwater pipeline construc-
tion can be done by bottom pull, floating pipe, and lay barge pipeline
positioning.  Lay barge techniques have been used to install underwater
pipelines of 30-inch diameter for distances over 100 miles.  In practice,
for design purposes, physical model experiments may be required to deter-
mine critical velocities or appropriate dilutions of the particular sludge.
     The costs of offshore pipelines generally vary with length of the
line, depth, pipe size, ocean terrain, and materials to be transported.
The greatest single cost factor in such pipelines is the installation cost,
which generally runs more than 50% of the total investment.  Maintenance
is usually the biggest cost factor in the operation of such pipelines.
Surface Craft Transport
     The generalized alternative to pipelines lies in carriage of the
material in batches by surface craft to a selected dumpsite.  A prerequi-
site for surface release is that the material have a density greater than
water—or in the case of inert or harmless materials, that it be soluble
with a rapid natural rate of dispersion.  The vehicle, i.e., the container
for this transport of the material, may be a barge or a self-propelled
craft.  The material itself may be in any one of many forms.  In general,
economics demand that the material be carried in as concentrated form as
possible and that the transport of large tonnages of water be avoided.
     Surface craft adequate fv r offshore disposal purposes exist and are
in use today.  Self-propelled hopper-type ships are also currently in use
for waste disposal.  The basic configuration of these types of vessels
would resemble the hopper-type dredges owned and operated by the U.S. Army
Corps of Engineers.  The capacity of these hopper dredges varies from a
low of 720 cubic yards to a high of 8,277 cubic yards; however, European
dredges are even larger.  Better (specially designed) equipment is feasi-
ble.   Newer designs may be required to control the rate of release of sludge

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particularly where high dilution factors are required.   However,  under
almost all conditions,  disposal of slurried FGC waste would be economically
impractical.  The cost  of transporting FGC slurries would be unattractive,
and reslurry of dry or  thickened sludge on board large  disposal vessels
could require impractically large pumping capacities.  A major cost con-
sideration for surface  craft involves the necessity to  employ two or three
crew shifts if the dumpsite is located outside a round trip range which
can be covered in eight hours or less.
     Surface craft can practice one of the following types of dumping:
     •  Direct release under gravity through the bottom of cargo craft.
     •  In recent years a new dump concept has appeared in the form of
        the clam-shell barge.  A. hopper barge is split along a vertical
        longitudinal plane and the two symmetrical halves are hinged  at
        deck level.  Buoyancy compartments are arranged so that when  the
        barge  is  loaded, control exists to open the  joint; when the hopper
        is  empty, controls can snap the two halves shut.
     •  In  cases  where the material is unsuitable or where operating  con-
        ditions mitigate against the use  of large hull openings and joints,
        the material must be lifted over  the side of the  craft and dumped
        into the  sea.  If a deck barge with bulwarks is used,  the material
        can be shoved  overboard through an opening in the bulwarks by
        some form of small bulldozer.  From a hopper, methods  as crude as
        the use of a crane and bucket  are employed.  The  latter requires
        expenditure of considerable power, use  of manpower,  and is unsuit-
        able in any sort of seaway.   Less power and  less  attendance is
        required  for pumping the material overboard, but  in this case the
        material  must  be liquefied to  the extent  that  a slurry is  formed.
      Scheduling  of ocean disposal  can also  affect  the  direction in which
 waste materials  are being transported,  and, hence,  environmental  impacts.
 If the  ocean disposal  occurs only on  the ebb or flood  tide,  dispersion of
 the waste  is  somewhat restricted  to  one direction.   Generally,  one would
 try to  maximize  seaward  dispersion.
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     To limit  the  impacts of sludge disposal, the location of dumping has
to be controlled.  There are two aspects to such control.  The first deals
with navigational  accuracy available (or the ability to find any speci-
fied dumpsite with precision).  The second deals with policing the opera-
tion to make certain that dumping takes place at the specified location
(within the accuracy limits of the available navigation systems).
     Adequate means of navigation are currently available to allow fixing
the location of any particular dump to well within one mile with visual con-
trol and within 0.8 to 5 km (0.5 to 3.0 miles) using navigation aids [29].
2.3.3  Current Studies

     At present, the major studies under EPA sponsorship or participation
relating to the ocean disposal of FGD wastes are:
     a.  The Arthur D. Little/New England Aquarium study [29, 31]
         for EPA on the technical, economic and environmental
         feasibility of the ocean disposal of stabilized and
         unstabilized FGC wastes.  This study includes both lab-
         oratory and small-scale field testing relating to impact
         issues.
     b.  The State University of New York (SUNY) [32] with funding
         provided from Power Authority of the State of New York,
         New York ERDA, DOE, EPRI, and EPA, is studying the use of
         stabilized brick-like FGC wastes (using IU Conversion
         Systems process)  to create artificial reefs for marine
         habitats.   This study is expected to continue for 2 to 5
         years.
     The preliminary conclusions from the Arthur D.  Little/New England
Aquarium study for the EPA are [31]:
     •  A case-by-case approach to the analysis of the environmental
        feasibility of ocean disposal of specific FGC sludges is
        needed.  The emphasis in each analysis should focus on the
        type of sludge and the disposal site environmental condi-
        tions.
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Unless further work contradicts observed and anticipated
benthic sedimentation impacts, including mudflows,  it
would appear that the disposal of untreated or treated
FGC sludges with soil-like physical properties by bottom-
dump barge or outfall on the continental shelf is environ-
mentally unacceptable.
The problems of disposal of sulfite-rich FGC sludges,
both on and off the continental shelf, appear to be much
greater than those associated with other FGC materials.
There appear to be special grounds for concern over the
potential for oxygen depletion in the vicinity of sulfite-
rich sludge masses.  However, sulfite toxicity may be a
relatively minor problem because of the significant rate
of the oxidation reaction.
Disposal options which still appear promising and are
recommended for further research include:
-  dispersed disposal of untreated, sulfate-rich FGC
   sludges on the continental shelf;
-  concentrated disposal of treated, brick-like FGC
   sludge on the continental shelf;
   dispersed disposal of treated, brick-like FGC sludge
   on the continental shelf;
   dispersed disposal of untreated, sulfate-rich FGC
   sludges in the deep ocean; and
   concentrated disposal of both untreated  and treated
   sulfate-rich FGC  sludges  in the  deep ocean.
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 2.4  Disposal Options  vs.  Potential  Environmental  Impact  Issues
 2.4.1  Overview
      Environmental  impact  issues  associated with FGC waste disposal
 are determined by a mix of four factors:
      •   Waste characteristics,
      •   Disposal mode,
      •   Site,  and
      •   Control measures employed.
      The range of options  in  terms of  control measures is sufficiently-
 broad that on balance,  technology exists for environmental sound disposal
 of  FGC wastes.
     The environmental  impact issues requiring consideration in handling
 and disposal  of FGC wastes are:
     •   Land-related,
     •   Water-related,
     •   Air-related, and
     •   Biological  impacts both in the site and adjacent areas and
         consequential effects.
     Table 2.1  discussed earlier  listed all potential disposal options
 for  FGC wastes.  Table 2.12 lists the issues and mechanisms or factors
 causing  the impacts.  Potential impact issues are highly site- and system-
 specific.  With that understanding, Table 2.13  illustrates the major  types
 of  impact issues associated with various disposal options.  As the matrix
 illustrates, the range of waste types and possible disposal conditions
 is  sufficiently broad to eliminate the potential for "generally significant"
 issues to be associated with any of the disposal options.   Further, site-
 specific application of  appropriate control technology can be employed to
mitigate adverse impacts.   In other words,  issues of potential significance
 in FGD waste disposal  can best be defined in terms of specific waste types
disposal practices,  and disposal environments.   The significance of many
potential impact issues needs to be better  quantified by additional field-
scale operating experience  (and environmental monitoring)  with FGC waste
                                  2-78

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                                   Table 2.12
                    Potential FGC Waste Disposal Impact Issues
 Impact Area

Air Quality
        Impact Issues
Fugitive Particulate Emissions
Gaseous Emissions
  (e.g., HS, S0)
     Mechanisms/Factors
Handling, Transport, Erosion
Biologic Interactions,
  Acid Leaching
Water Quality
Groundwater Contamination
Surface Water Contamination
Leaching
Runoff, Overflows, Leaching
Land Use
Physical Disruption
Land Reclamation/Reuse
Stability
Disposal Mode, Stability
Biota
Habitat Displacement
Bioaccumulat ion/Transfer
Disposal Mode
Water Quality, Direct Uptake
                                         2-79

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                                          Table 2.13
         Disposal Options Versus Potential Environmental Impact Issues for FGC Wastes

                                                 Potential Environmental Impact Issues




N>
00
O
Disposal Options
Wet Ponding
Dry Disposal
Surface Mine Disposal
Underground Mine Disposal
Shallow Ocean Dumping
Deep Ocean Dumping
Land Use
2
2
2
3
3
3
Surface Water
Quality
2*
2*
2*
3
2*
2*
Groundwater
Duality
2*
2*
2*
2*
3
3
Air
Quality
3
2*
2*
3
3
3
Biological
Impact
2*
2*
2*
2*
2*
2*
 X
   Significance highly uncertain due to data gaps.
 Key:   1 = Issue of potential general significance for all FGC wastes at all disposal sites.
       2 = Issue of potential significance for specific types of FGC wastes and/or specific
          disposal sites.
       3 = Issue of minor or no potential significance.
Source:   Arthur D.  Little,  Inc.

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disposal.  As indicated in the matrix, this is particularly needed for
defining potential issues in the categories of water quality and
biological impacts.
     The remainder of this section provides introductory information on
the general mechanisms of potential environmental impact in each of the
issue categories shown in Table 2.13.   The section concludes with a dis-
cussion of the means by which broadly defined issues become specific and
subject to more thorough quantitative and qualitative evaluation for
various FGC waste types, disposal practices, and disposal environments.
Section 4.0 presents results of such evaluations reported as of late 1978.
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2.4.2  Mechanisms of Environmental Impact for FGC Waste Disposal
     The chemical and physical properties of FGC wastes (discussed in
detail in Volume 3 of this report) create several mechanisms of poten-
tial impact in each environmental medium (air, water, etc.).  These
mechanisms are discussed below under headings corresponding to the various
impact media.  This discussion is intended to provide perspective as a
precursor  to subsequent sections dealing with specific research programs
and their findings.
2.4.2.1  Land-Related Mechanisms of Impact
     This section is divided into two parts, focusing respectively on the
technical (i.e., physical) nature and the public-policy implications of
the impact mechanisms associated with the use of land for FGC waste dis-
posal.
2.4.2.1.1  Technical Nature of Land-Related Impact Mechanisms
     The stability of FGC wastes after disposal is a major influcence
on the impact potential of the various disposal options.  This is because
physical instability can have adverse impacts on disposal site reuse,
and chemical instability can be a mechanism of contaminant mobilization
in the disposal environment.
     Physical instability is a potential problem for all FGC wastes, in-
cluding treated wastes.  As discussed in Section  2.2,  significant data
gaps exist in engineering information.  Three processes that have important
effects on the physical stability of FGC waste material are consolidation,
subsidence,  and liquefaction.  Secondary considerations (but also
important) are durability and permeability.
     •  Consolidation is the change in volume of the material caused
        by flow of liquid out of pores between solid particles under
        a hydraulic gradient created by the weight of the material
        itself or by the application of external loads.  In fine-
        grained materials such volume change and consequent surface
        settlement may require months or years to reach completion.
     •  Subsidence  (surface settlement) may be caused by consolida-
        tion of waste materials or by loss of basement support (as
        might happen in a mine disposal situation).  Subsidence may
        occur episodically from loss of basement support, but usually
        occurs over relatively long time periods (months to years).

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        This is in contrast to liquefaction, which can take place
        suddenly and without warning.
     •  Liquefaction  can occur in a saturated waste which, like fine-
        grained, relatively cohesionless soils, under loading cannot
        drain freely; the pore water pressures may increase until the
        intergranular stresses are eliminated.  The shear resistance is,
        therefore, nullified, and the material flows like a liquid.
         Such  loading may  be  caused by  the  vibration  of heavy  machinery,
         including bulldozers, blasting,  pile drivers, or earthquakes.
     A mass of liquefied FGC wastes  would flow very rapidly, possibly at
speeds of tens of feet per second near a failing wastes deposit.  Speed
of flow would approach that of water at very low sludge (or mix) solids
contents.   Speed would decrease with distance from the failing mass and
with increasing solids content.
      Vibrations  can also  cause excessive subsidence  in fine-grained
 cohesionless  materials  (which includes most FGC waste).   The  frequency of
 the  vibration is a key  determinant  in  the  degree  of  subsidence.   If the
 vibration frequency approaches the  critical frequency, subsidence may  be
 20 to  40  times  as great as  that  caused by  an equivalent  static  load.
 The  greatest  amounts of consolidation  occur from frequencies  in the 10
 to 30  Hz  impulses  per minute range.   The problems of susceptibility to
 vibrations are limited by two circumstances.  The influence of a point
 source of vibrations  diminishes  geometrically with distance.   In addi-
 tion, properly compacted materials  (e.g.,  compacted with vibratory
 rollers at proper moisture content) are not vulnerable to subsequent
 vibrations.
      The durability of the materials within a filled area is critical
 as it relates to the  maintenance of structural integrity.  Freezing has
 been observed to cause fracturing of sludges and subsequent subsidence
 due  to loss of compressive strength.  Freeze-thaw cycles could have
 several effects.  Fixation reactions could be retarded, disrupted, or
 destroyed by an episode of freezing soon after mixing and placement.
 Freezing could produce cracks in the near surface layers of a waste
 deposit (frost polygon behavior).  Cracks in the wastes deposit could
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yield  greater mass permeability  and infiltration rate even though
waste  blocks between  cracks had  been  compressed and even dewatered.
     Durability  is a  waste- and  site-specific property which can best
be  determined in the  field over  a  length of years through many lab anal-
yses of aged field samples.  Mass  permeability and infiltration are
important in that increases and  decreases in the water content of unsat-
urated materials will alter their  properties and thereby alter the
stability of the materials.  Thus, the grading of a filled area
(and hence, the  extent of infiltration of precipitation) may be critical
to  its stability.  Increased infiltration could lead to saturation of
wastes previously unsaturated and  could cause generation of significant
porewater pressures.  Saturation would increase the weight of the wastes,
and porewater pressure generation  would decrease effective stress, thus
decreasing the strength of the wastes deposit.  Both factors tend to
lead to sliding/slumping.  This  would be most likely to occur with wastes
of  highest permeability in an unsaturated condition, but it could occur
in  any FGC waste deposit.
     There are various processes which can be used to alter both index
and mechanical properties of FGC wastes.   (See Volume 3.)  Addition  of
chemicals such as lime, silicates, and aluminates can cause a pozzolanic
reaction to occur in  fine FGC wastes  in the presence of water.  Like con-
crete, these pozzolanic materials  require a curing period.  Other commer-
cial processes have been developed which produce soil-like rather than
concrete-like substances from FGC  wastes.  The pozzolanic materials, when
properly cured,  can be stronger  than  underlying soils.  Soil-like treated
wastes are generally denser, stronger, less compressible,  and less per-
meable than many untreated FGC wastes.  Thus, the placement of treated
waste  is not as  environmentally  important as that of untreated waste
from a stability standpoint.
     Data is lacking on "lifetimes" of fixed wastes.   Chemical species
created during fixation may  propagate in the field during completion of
initiated reactions;  they may be altered or they may be removed.   If the
bonding between particles, which was created during fixation, is weakened
or eliminated,  instability may result.  This is a complex question,  e.g.
Portland cement concrete increases in hardness,  stiffness,  and strength
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for years after mixing and placement if weather and other factors (e.g.,
sulfates in the groundwater) do not cause deterioration.
     Physical factors such as compaction effects also may alter with
time.  If the wastes are saturated with low solids content, consolidation
may occur with significant increase In solids content, stiffness, and
strength; this may be significant for thickener underflow consistencies.
Increase in density (and consequent increa 2 in "trength) created by
compaction should not disappear, but long-term saturation may dissipate
suction effects (and the increase in strength ilue to suction) croated
during compaction.  Dissipation of suction effects would have* most effect
near the surface of a waste deposit because, at depth, overburden pres-
sures continue to create interparticle stresses equal to the interparticle
stresses previously created by suction in the porewater.
     Co-disposal of mixtures of ash and sludge  (see  Section  8.2.2)  exhi-
bits impact potentials different  than those  of  independent disposal.   It
may be easier to handle the sludge-ash mix than to handle  (transport,
place, compact, etc.) sludge or ash alone.   The potential  air  emission
problems of dry ash handling would be eliminated.  Fill  construction
would be easier using one material rather than  two at the  same site.   The
mix of ash and sludge should be less compressible and stronger than sludge
alone and less subject to erosion than ash alone.  The mix of  ash and
sludge may be self-hardening or it may require  less  fixative in a mixed
fill than the materials would  in  separate fills.  A  possible disadvantage
could be an increase in permeability (ash-sludge mix vs. sludge alone)
with potential for more infiltration and leaching.
2.4.2.1.2  Land Use Policy  Implications  of  FGC Disposal
      Land  use impact issues, viewed from the "Public Policy" standpoint,
 are focused  on three aspects of FGC waste land disposal options:
      •  Site location,
      •  Post-closure land use  of  a disposal site,  and
      •  Impact potential  of disposal on adjacent  lands.
      As the  above list indicates, the  significance of these issues is
 highly site  specific.   However, they are dealt with in the generic sense
 in the discussion below.
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 Site Location
      The mechanism of impact on public policy in this instance is simi-
 lar for FGC wastes and most, if not all, other solid wastes.   At the
 local level, fulfilling land requirements for solid waste disposal has
 become problematic in many areas;  either because of a lack of suitable
 available land, and/or because of local public resistance to  sites
 chosen for waste disposal.  This situation is reflected in regulations
 being  developed at both the federal and state levels.   A recent  draft  of
guidelines, generated  under the Resource Conservation and Recovery Act
 (RCRA)  for the  development of  state solid waste  management  programs  [33]  for
 non-hazardous wastes,  requires  that  state plans include  provisions for
 adequate  disposal  facilities as well as identifying  or  obtaining the plan
 implementation  authority.   Similar  wording can be  found in  some  existing
 state  solid  waste  management regulations for  approval of county  or muni-
 cipal  solid  waste  programs.  (See Section 3 of this  volume.)   It is empha-
 sized  that problems in  initial  site location, when they exist, would be
 location-specific  rather than  generic  to FGC  waste types or disposal
 practices.
     The  potential designation  of FGC  wastes  as  hazardous or  "special" under RPRA
 could  exacerbate problems  with  site location  due to  public sentiment.
Again,  these would be location-specific issues.  Some current  state
regulatory programs address  this  issue.   Under existing California regu-
lation, FGC  wastes would apparently be included  among "Group I" wastes
requiring disposal in sites  that  provide maximum protection from  leaching
and surface  runoff [34]. Oregon's regulations illustrate  a different issue-
in that state, hazardous waste  facilities must be state owned.
     Waste land areai, with irregular topography  (for ease of containment
and a source of cover  soil) and highly impervious subsoils, would.be ideal
sites for FGC waste disposal.  Valuable, flat or uniformly sloping areas
with highly pervious soils and scarce, pure (thus valuable)  groundwater
would be poor locations for disposal sites.
     The above discussion assumes that open land would have to be found
for a disposal site.  Disposal of FGC wastes in operating surface or
underground mines or at abandoned mine sites would not require "new"
land.   The regulation  of non-coal waste disposal at active mine sites is
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(as of early 1979), still under consideration by the Office of Surface
Mining due to the Surface Mining Control and Reclamation Act.   (See
Section 3.)  The use of FGC wastes in abandoned mine reclamation is
discussed further below.
Post-Closure Land Use of Disposal Sites
     The present regulatory climate, defined by existing and emerging
regulations, establish post-closure land use of disposal sites as an
impact issue that must be considered:

     •  Under Federal standards for hazardous waste disposal facilities
         [3], land at a closed site must be "amenable to some productive
        use."  Where wastes remain at a disposal site, certain land
        uses are precluded  (residential and agricultural, for example).
     •  Some state solid waste programs already include bonding require-
        ments for either solid waste or hazardous waste site operations
        to  cover site reclamation and even "perpetual care" of sites
        where considered necessary.  (Examples include:  Kansas, 1978;
        and Tennessee draft regulations, 1978.)  The Kansas Solid Waste
        Management Act even includes requirements for a site post-
         closure land use plan  to  accompany  the permit application  for
        non-hazardous wastes.   Restrictive  covenants can be established,
        where deemed necessary,  to  limit land  use or describe mitigating
         requirements for closed disposal sites.
      •  The Surface Mining Reclamation and  Control  Act  requires  recla-
         mation  of  mined land,  in most  situations,to be  capable  of  sup-
         porting its pre-mining uses.   It also establishes  a fund,  for
         use by  states,  for abandoned mine  reclamation.
      Post-closure  land use would tend  to be limited by  the nature of the
 loads created or by the sensitive nature of the structures or facilities
 built on the waste fill.   For example, placement of some sort of fill in
 a uniform layer over the entire waste  deposit should  be feasible,  but
 imposition of concentrated loads (e.g., footings in a building) may
 cause bearing failure with rapid plunging  of the loaded element into the
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wastes.  Vibratory loads as from machinery foundations could have
adverse effects on unfixed wastes.  The rate of application of load also
is extremely important—loads applied slowly may allow consolidation of
the wastes during loading, yielding higher strength than for material
loaded rapidly.  Rapid application of load increases shearing stresses
and may decrease shearing resistance if the structure of the wastes is
disturbed (collapse or remolding).
     The nature of the supported use also is important.  A park built
on cover soil over FGC wastes would not be affected seriously by wastes
settlement.  A low, flexible structure like a warehouse would exert low
loads and could tolerate greater total and differential settlements than
could a structure like a boiler-turbine-generator complex.
     The various disposal options for FGC wastes present somewhat dif-
ferent potential impact issues relevant to post-closure land use.  These
issues are discussed separately below for the various land disposal
options, noting that this is a general, not site-specific discussion.
Dewatered Impoundments and Dry Disposal
     For a discussion of post-closure land use impacts, it is assumed
that the final closure procedure for these options would include some
type of soil cover once drying or setting is complete.  In addition to
the overall stability of the closed disposal area (discussed in 2.4.2.1.1
above), suitability for post-closure uses could be determined by the
revegetation which may be accomplished, and the extent to which migration
of waste-related contaminants could occur.  The latter issue includes
the degree to which the underlying material could reduce vegetation
growth rates and/or result in significant vegetative uptake of trace ele-
ments.  Thus, the attentuation capacity of surface and underlying materials
climate regime of the disposal site, as well as the physical and chemical
characteristics of the disposed material are important contributors to
determination of site reuse capabilities.  Another question concerning
reuse potential is whether or not there are ameliorative properties of
FGC wastes (or waste components)  for certain soil types that would
justify this type of land application.   A corollary question is whether
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or not a final soil cover would have to be used to eliminate some trace
contaminant impact potential if food-chain vegetation were to be grown on
a waste/soil mixture.
Mine Disposal
     The use of FGC waste in the reclamation of surface or underground mines
would appear to be a potentially satisfacf-ory disposal practice, especially
where used to limit acid mine drainage.  Howevtr, disposal in surface mines,
while feasible, is space limited (and hence, time limited) due to the
reclamation requirements of the Surface Mining Control and Reclamation
Act.  Disposal in abandoned underground mines appears likely to be
limited in many cases by abandoned mine conditions.
     Long-term land use impact issues associated with FGC waste disposal
in surface mines  are similar to those associated with landfills, although
the significance of impact may vary due to variations in the depth of
placement of disposal material and disposal techniques.  Given SMCRA
reclamation requirements, it is important to address the degree to which
the physical or chemical characteristics of the waste material could
affect post mining reclamation efforts (e.g., the stability and contam-
inant migration issues discussed above).  The potential for migration of
contaminants into surface soils would be an issue of greatest concern
for surface mines located in areas of prime farmland.
     The existence of an underground mine would appear to be a more
significant issue in limiting post mining surface land use  in most cases
than would  the additional disposal of FGC waste in  the mine.  Two notable
exceptions must be considered:  (1) the long-term potential (if any)  for
S07 emissions in acid mine  areas; and  (2) future surface  stability.
2.4.2.1.3    Impact  Potential of Disposal on Adjacent :Land
     Mechanisms of offsite  land use impacts are essentially similar  for
all land-based FGC waste disposal options.  Uses of adjacent land  could
be  restricted by access or  geometry limitations  (e.g., difficulty  in
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 building  access  roads  across waste  deposits)  or by consideration of
 possible  failure of wastes  retention   structure,  or by pollution effects
 (losing the  use  of groundwater  through pollution  by leachate  from FGC
 wastes).   The  impact mechanisms  of  principal  concern are  the  potentials
 for  leachate to  enter  groundwater systems and for contaminants to enter
 surface water.   These  issues are both  discussed in the following section.
 These are only indirectly land  use  issues--insofar as water issues do
 have an impact on users  (well water contamination, for example).  Varia-
 tions in  the significance of impact would occur for different waste
 types, site-specific climatic and hydrogeologic conditions, and disposal
 techniques.
      The  case of  very  large impoundments built by construction of a dam
 may  pose  an  additional issue.  This would include the extent  to which a
 valley watershed  serves  downstream  users and  the  degree to which the dis-
 posal site would  affect  long-term alterations  in  surface water conditions
 (i.e., quantities and  quality).
      It is also  possible that the nature of adjacent land use could affect
 the  suitability  of some  locations for  use as  FGC  waste disposal sites.  For
 example,  if  a prospective FGC waste disposal  site was immediately down-
 gradient  of  a mining or  logging  area,  removal of  vegetation on the adjacent
 area  could affect erosion rates  (and stability of the downgradient FGC
waste site.
 2.4.2.2  Water-Related Impact Mechanisms
      For many disposal options,  the potential for water contamination can
be among  the more serious environmental impact issues pertaining to the
disposal of  FGC wastes.  As .'s true for other potential impact mechanisms
 the potential for water  contamJnation  as a result of FGC waste disposal
 is highly site specific  and sometin-is waste specific:   control measures
required at one site may be unnecessary at another; practices useful in
controlling or preventing water contamination at  one site may not be
efficacious at others.   Understanding of the mechanisms of surface and/or
groundwater contamination by FGC waste disposal has been limited by the
lack of field-scale disposal and monitoring experience.   This constraint
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is still effective today, but increasing requirements for the protection
of water resources have led to a substantial recent expansion in research
efforts.  The recent announcement of a large EPA Program [21] and EPRI
Program [15] are expected to fill this gap.  This is discussed in Sections
4.2, 4.3 and 4.4 below.
     Table 2.14, outlining potential water impact issues, indicates that
some potential for water contamination exists for ocean disposal and
all land-based disposal options, including transportation.   However,
as indicated, the probablility of water contamination during transport
is quite low, and no research or regulation of transport of FGC wastes,
with specific emphasis on water, is anticipated.
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                                                    Table 2.14

             Relative Potential for Water-Related Impacts from Different FGC Waste Disposal Options
                                                                  Disposal Option
NJ
I
NJ
Waste Type
1 Ash
2. Sulfite Rock
3. Mixed Sulfite/Sulfate
4. Sulfate Rock
5. Stratified Waste

6. Sulfur

Transportation
Low
Low
Low
Low
Low

Low

Ponding
High
High
High
High
Moderate
or NA
NA

Dry Disposal
High to
Moderate
n
n
Moderate
Moderate

Low to
Moderate
Surface
Mine Disposal
High to
Moderate
"
n
"
"

Low to
Moderate
Underground
Mine Disposal
High to
Moderate
"
"
n
"

n

Ocean Disposal
High
"
"
Moderate
Moderate

Moderate

    NA • Not applicable
         Actual adverse  impact potential  is mitigated  for  all  options by available
         control technology and regulatory requirements for  the protection of water
         quality.

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     It is important to remember that this table and discussion are on a
relative basis among disposal options.   The potential for negative
impact is compared on a disposal option vs. waste type basis.  When con-
sidering the actual characteristics of a disposal operation, that is,
disposal option x waste x site x coi.trol measures implemented, it may be
feasible to reduce or eliminate the actual impact even for option x waste
combinations which have a high generic prcjability of impact.
     Unstabilized sulfite-rich sludges are identified as having a high
generic potential for water impact for all disposal options except dry
disposal, which is not considered feasible for such a sludge.  Features
of unstabilized sulfite-rich sludges which lead to their relatively high
generic impact potential are:
     (a) Their high water content which, through a variety of mechanisms
         including physical instability, increases the likelihood of
         interaction between the waste and ambient water [35,36],
         [37]; and
     (b) The relatively high COD of sulfite-rich sludges which can lead
         to initial depletion of dissolved oxygen in ambient water when-
         ever it interacts with the waste  in an agitated medium
         [38,39].
     Other unstabilized sludge has only slightly lower generic potential
for water impacts than sulfite-rich sludge.  Unstabilized sludges by
definition have poorer physical stability, and disposal site management
for control of runoff and leachate is  consequently more difficult.  Such
practices, as grading to promote runoff and eliminate standing water,  thus
reducing leachate generating, are reportedly infeasible for most untreated
FGC sludge  [35,36].  Leachates from untreated sludges  can exhibit
concentrations of various parameters,  including IDS, SO  , Chloride,  As,
Se, and Hg,  in excess  of EPA drinking  water standards, defining  leaching
as  an  impact mechanism of  considerable interest  [39.40J,
     Several investigators  have concluded that  stabilization of  FGD
sludges by  addition of such pozzolanic substances  as  fly  ash, fly ash
and lime,  or  Calcilox®, will reduce  permeability  and leachate concen-
trations  of TDS  and certain major  dissolved constituents  [35,36].
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Thus,  stabilization  affects  the  probability of water contamination  as a
result of disposal of FGC wastes.  However, some studies report that not
all parameters are reduced in  leachate  from stabilized FGC materials;
some exhibited increased concentrations [41].   The magnitude of the
reduction in mass of pollutants  released, estimated by one report at
1/20 of the pollutant potential  of untreated sludge  [9]  is not so
great  as to entirely obviate the potential for water contamination.
Furthermore, as is true for other proposed control measures, evidence
of the effect of stabilization [9]  on water impact in field tests
is unavailable at this time.   Accordingly, the potential for water con-
tamination by disposal of stabilized sludges is still considered a
realistic mechanism of impact.
     Fly ash disposal also presents a significant potential for water
contamination because of the relatively high concentrations of trace
elements sometime found in fly ash leachate.  Theis  [42] reported
cadmium, lead, and arsenic concentrations in excess  (4 to 25X) of EPA
Interim Primary Drinking Water Standards in fly ash and leachate.
     Ocean disposal, ponding,  and disposal in the surface mine pit
present high generic potential for water contamination because in
each case the waste is likely  to be in intimate contact with surface
water  and/or groundwater in the saturated zone.  The maintenance of water
head in a pond causes percolation into the soil and eventually can
result in elevation of the water table beneath the pond.  Lining the
pond is a way to retard or prevent this sequence, but available liners
are generally not perfectly impermeable and are subject to leaking
[43,44].
     FGC waste disposal in the working pit of a surface mine followed
by covering with overburden creates a mechanism of potential groundwater
impact because the pit floor is often below the water table.  Disposal
in the spoil banks,  just prior to reclamation, would generally result in
wastes being placed above the water table with less opportunity for inter-
action with groundwater aquifers.  However, infiltration of precipitation
and leachate generation may still lead to water contamination with this
practice.   The generic significance of this impact mechanism is considered
similar to that associated with other dry disposal operations.

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     Impoundment without maintenance of water cover is considered inter-
mediate in potential for water contamination between ponding and dry
disposal for all stabilized FGC wastes.  This reflects the greater initial
water content of the wastes, which are pumped or sluiced to the impound-
ment, in contrast to dry disposal techniques.  This greater water content
increases the potential for interaction between ambient surface and ground-
water and the waste.  As discussed further in Section 4.2.4, leachate
generation and discharge can be reduced more effectively with dry handling
techniques via disposal site management practices  [6,23,24].
     Disposal of FGC wastes in underground mines provides mechanisms of
potential positive and negative water impacts [19].  Because they are
often neutral to basic in pH, FGC wastes may serve to mitigate some
instances of acid mine drainage.  However, it appears that mechanisms of
potential negative impacts discussed for other disposal options would
also be operative in underground mine disposal.  Specifically, leachate
from within the mine, and runoff and/or leachate from any waste-related
waters collected and pumped out of the mine would  be mechanisms of
interest.
2.4.2.3  Air-Related Mechanisms of Impact
ponding
     Wet ponding involves the disposal of  slurries of FGC wastes  in ex-
cavated or diked areas.  Because  the waste is always  covered by water,
the only emissions  to the ambient air  are  a  result of short-haul  trucking,
when it occurs  if the material  is dry; often wet material  is transported.
Most of the dust emissions  of native soil  from  such  trucking would  consist
of  large particles  that  settle  out near  the roadside.   According to the
Clean  Air Act as amended,  "fugitive dust  emissions"  of  native  soil  from
this type of activity are not  subject  to  Prevention  of  Significant  Deteri-
oration permit  review.   Revegetation or  other activities on the pond after
it  is  filled with waste and water removed (i.e.,  possible operational
phase) may be  subject  to fugitive dust.   Proper planning can minimize
 this impact.
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 Dry Disposal
      An alternative  impoundment procedure  is dry disposal wherein the
 FGC waste  is dewatered  to  a  product having the  consistency of moist soil.
 Where dewatering occurs at the FGC system  site, short-haul trucking and
 the use of conveyors are likely means of transport.  The waste material
 is  layered in the disposal basin  in six-inch to one-foot lifts and com-
 pacted  using standard earth  moving equipment.   Compaction serves the
 purpose of preparing a  waste surface that  is very resistent to weathering
 (wind  or rain erosion).  While the wastes  retain at least 5 to 10% mois-
 ture,  this type of operation does not result in any long-term air quality
 impact  potential.  It is possible that the dewatered and deposited wastes
 after  drying may be  subject  to wind erosion at  the surface unless control
 practices prevent it.
 Mine Disposal
     As  described earlier  in Section 2.2.3, in surface mines there are
 basically three options for  the placement  of wastes:  (1) in the working
 pit, following coal extraction and prior to return of overburden; (2)
 in  the  spoil banks, after  return to the overburden but prior to final
 reclamation of the land; and  (3) mixed with or sandwiched between layers
 of overburden.  With the exception of option three, each case has the
 potential to impact air quality adversely  after the waste drier.  The
 extent of actual emission will depend on whether the wind velocity is
 sufficient to transport the  particles (generally more than 16 kph or
 10 mph) even after the surface is dry and  can be subject to wind erosion.
     The air quality impact mechanism associated with underground mine
disposal consists mainly of  the potential  reaction of mine acid drainage
with calcium sulfite in the waste, producing sulfur dioxide gas.  This
reaction is expected to occur only in the initial period following dis-
posal because the buffering capacity of the waste would eventually raise
the pH of the mine drainage in immediate contact with it.  An additional
possible source of gaseous emissions,  over the long term, is microbial
oxidation.
     Atmospheric emission of these gases could correspond to drops in
atmospheric pressure, causing the mines to belch gas.   This type of
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emission source would be intermittent and of duration only long enough
to allow atmospheric pressure equilibration.
Ocean Pumping
     The only adverse air quality impacts associated with this alterna-
tive are due to native soil "shake-up" caused by truck haulage over
dirt roads and/or wind erosion of a dry FGC waste while being transported.
In the former case, regulations exempt the emissions.  In the latter,
covering and/or transporting moist material would minimize emissions.
2.4.2.4  Potential Mechanisms of Biological Impact
     Mechanisms of potential biological impacts from FGC waste disposal
are derived from disposal and material characteristics discussed above
as mechanisms of potential land-, water-, and air-related impacts.  In
other words, if one considers land, water, and air impacts as "primary"
impacts of disposal, then resulting biological impacts might be termed
"secondary."  The importance of this concept can be better illustrated
 in subsequent sections of the report because it implies that control
 technologies applied to mitigate land, water, and air impacts have
 the effect of mitigating biological impacts as well.
     Mechanisms  of  potential  impact  derived from  the land  impacts  of
FGC waste  disposal  can  be  described  by the  phrase "direct  habitat  modi-
fication."  For  each  of the  land-based disposal options  discussed  in this
report, varying  amounts of habitat could  be directly modified by  the
placement  of wastes in  ares  previously occupied by vegetation and  wild-
life.   Underground  mine disposal  has minimal implications  from  this
standpoint,  mostly  relating  to  the transport and  interim storage  of  the
wastes.  Disposal in  surface mines has this type  of impact potential
only  insofar as  FGC waste  substrates might  be more or. less supportive of
future revegetation and reoccupation by wildlife  than other  possible
reclamation substrates. Wet or dry  impoundments  and landfills  create
the most  potential for  direct terrestrial habitat modification by the
mechanism of devotion of previously  undisturbed  land to FGC  waste dis-
posal. The degree of significance of this  type of impact mechanism is,
by definition, highly site  specific,  since,  for example, some of the
devoted land may, in fact, have been greatly disturbed by other activi-
 ties  prior to its use for  FGC waste  disposal.  (This is true for many
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 "captive"  sites on utility property.)   Over  the  long  term,  some  land-
 based  disposal options,  upon completion,  represent  a  potentially positive
 mechanism  of  habitat modification  impact.  This  is  because  revegetation of
 these  areas can create new habitats  that  (for  a  time) add diversity  to
 their  surroundings (e.g.,  a grassland  or  early succesional  shrub com-
 munity within a forest environment).
     Conventional; disposal of unstabilized FGC wastes in the  ocean has
 the  potential to substantially modify  the suitability of substrates  as
 habitat  for benthic organisms[31].   The  mechanism  of potential  impact in
 this instance is replacement of  coarse, relatively  stable natural sub-
 strates with  a fine, relatively  unstable  one.  It has been  suggested that
 certain  types of stabilized FGC  wastes may create desirable new  habitats
 (i.e., artificial reefs) when placed in the  ocean[32].
     Some of  the mechanisms  of potential biological impact  derived from
water-related  FGC waste disposal impacts can be referred to as examples
of "indirect  habitat modification."  Examples  include the potential
 impacts of increased volumes  of dissolved, suspended  (and/or settleable)
 solids on aquatic biota downstream of supernatant discharges from FGC
waste disposal ponds (wet  impoundments).  The  potential impact mechanism
of sulfite-related  oxygen  depletion  (discussed above  in 2.4.2.2) would
have direct and  indirect biological impact implications in  both  ocean
and  fresh-water  systems.   Localized dissolved  oxygen  reductions  in these
systems could  directly impact  aquatic biota requiring oxygen for respira-
tion and indirectly affect  these and other organisms by affecting the
toxicity of other substances  in the environment.  The release and trans-
port of trace  constituents of  FGC wastes  (especially metals) in  aquatic
systems creates  two potential  impact mechanisms of interest:  (1) direct
toxicity to exposed organism^,; and (2) accumulation by exposed organisms
leading to subsequent toxicity elsewhere in the food web.   In fresh
waters, leachate  and runoff from disposal areas are the precursors to
these potential  impact mechanisms.  In the ocean, direct discharge would
take place, followed by long-term leaching opportunities.
     Mechanisms  of potential biological impact derived from air-related
FGC waste disposal impacts appear to be relatively minor in extent.

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In theory, the mechanisms described above (Section 2,4,2.3) could create
small zones of increased exposure to particulate and/or gaseous emis-
sions.  However, the opportunities for significant increases in exposure
risk seem to be severely limited by the combination of disposal locations
(e.g., deep mines) and contaminants of interest (fugitive particulates),
2.4.3  Issue Definition Process
2.4.3.1  Introduction
     In the broadest, most general sense, the environmental issues associ-
ated with FGC waste disposal are defined by the characteristics of the
wastes and the disposal options.  This level of issue definition is re-
flected in the general discussion of potential impact mechanisms in
Section 2.4.2 above.  Further issue definition (i.e., better identification
of impact potential) is important in the development of a reasonable
strategy for environmental management of these wastes.  That is the focus
of the R&D efforts described later in this report (4.0).  Specific issues
are defined by the regulations governing FGC waste disposal, usually in
the forms of disposal restrictions, performance criteria, and monitoring
requirements.  Therefore, the remainder of this section (2.4.3) provides:
(1) a status summary of the regulatory framework relevent to issues
associated with FGC waste disposal (and discussed in much greater detail
in Section 3 of this volume); and  (2) a discussion of a process by which
issues may be prioritized in the evaluation of the results of environmental
assessment studies.
2.4.3.2  Status of Issue Definition by Regulations
     A detailed discussion of the  status of regulations pertinent to FGC
waste disposal  is presented in  Section 3 of this volume.   This section
is intended to  serve as a means of linking the information presented in
Section 3 to the  environmental  issues discussed throughout  Section   2.4.
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      Table 2.14 summarizes the present status of issue definition by
 regulation of FGC waste disposal.   The major  point  illustrated  by the
 table is that virtually no specific regulations  exist  for  the sole pur-
 pose of governing the disposal of  FGC wastes.  Such regulations are
 either pending development (e.g.,  under RCRA  and the Surface Mining
 Reclamation and Control Act)  or exist only  in the form of  more  general
 restrictions  applicable to a  variety of waste types.   Because of pending
 decisions in  several areas, the degree to which  FGC waste  disposal impact
 issues are specifically defined by regulations is in a particularly
 important state of flux.   Pending  decisions about the  classification of
 these wastes  under RCRA, and  about the procedures for  regulating "priority"
 or  "toxic" pollutants  under the Federal Water Pollution Control Act will
 help to crystallize the issue definition process  when  they are  made.
      In spite of  the uncertainties created by the present  state of flux
 in  the regulatory process, another significant point illustrated by
 Table 2.14 is that all of  the potential environmental  impact issues
 associated with FGC waste  disposal are  subject to some  form of  present
 or  future Federal regulatory  attention.  Thus, the  environmental assess-
 ment and other  R&D efforts reviewed in  this report  can  be  integrated as
 appropriate into  the regulatory framework, rather than  existing as  "paper
 studies"  in a vacuum.

2.4.3.3   Prioritization of Impact  Issues

      Given the  pending  state  of regulatory development described above
 the  authors of  this  report have had  to  create certain guidelines for
 prioritorization  of  efforts to report evaluations of potential  impact
 issues.   In general, an effort has been made to give highest priority to
 evaluations of  potential impact issues associated with well-designed,
well-run  FGC waste  disposal operations.  In other words, wherever possible
attempts  have been made to identify separately these types of impacts and
 those  that might be  characteristic of poorly designed and/or poorly run
operations.  A  third category, consisting of impacts associated  with
abnormal  events, has also been identified.
                                  2-100

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                                                    Table  2.15

            Status  of Issue  Definition by  Regulations Governing Disposal of  FGC  Wastes
                   Res.  Cons.   Fed. Water     Clean  Surf. Min.     Dam  OSHA    Marine Prot.,    Safe Drink.   Coal Mine
                     & Rec.    Poll. Control    Air   Rec. & Con.   Safety         Res., Sanct.     Water Act  Health/Safety
                      Act         Act

 Physical Stability    P

 Land Use Policy       P

 Water Quality         P          G,P

 Air Quality

 Biological Impact     P          G,P



 Potentially Appli-
 cable Disposal        1,2       1,2,3,4      1,2,3,4      3,4          1 1,2,3,         5             4           3,4
 Options                                                                 4,5



 Key to Descriptions of Status:  S » Specific regulations exist for FGC  waste disposal.
                               G - General regulations exist for waste disposal.
                               P • Further regulations authorized but  pending.



Key to Potentially Applicable Disposal Options:   1 - Impoundment
                                                2 - Landfill
                                                3 - Surface Mine
                                                4 - Underground Mine
                                                5 » Ocean Dumping
Vet
G
G
-
G
G
Act Act
G,P G G
G,P
G,P
G
G,P
Act
G
-
G
-
G
Act
G
-
P
G
-

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     In the absence of specific regulations, "good design" and "good
practice" are more difficult to characterize, since both are often
practically defined on a site-specific basis by the amount a disposer
needs to  (or is willing to) pay.  Accordingly, many of the early
environmental assessment studies of FGC waste disposal have failed to
characterize the design or operational efficiency of the operations under
investigation.  This introduces many caveats into the review of such
studies presented below in Sections 4.2 and 4.3.  Additionally, it
requires that some of the discussion of potential impacts of well-designed
well-run disposal operations appears in Section 4.4, where possible
mitigative control technology for disposal operations is assessed.
                                 2-102

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2.5  Site Selection,  Design and Practice
     Increasingly stringent environmental and economic constraints place
increased emphasis on three aspects of FGC waste disposal:
     •  Site selection,
     •  Design, and
     •  Operational practice.
For new facilities full optimization of each of these is essential.  In
this subsection some of the important considerations in each of the
above will be discussed.
2.5.1.  Land Disposal
2.5.1.1  Site Selection
     Siting of major solid waste disposal facilities like FGC wastes
is drawing substantial regulatory interest.  Environmental impact, as
well as engineering/economic factors, must now be assessed.  In essence,
the balance between potential  environmental  impact and costs must be
part of the decision-making process  in  the selection of an FGC waste
disposal site.  Further, the requirements under RCRA and state regu-
lations are baselines  that define acceptable environmental standards.
The identification and evaluation of  FGC waste disposal facilities is
becoming a major  factor in siting new coal-fired utility plants.  Many
of the environmental and engineering/economic evaluations conducted in
power plant site  selection endeavors are  equally applicable to the
siting of FGC waste disposal facilities.  Also, much of the technical
and environmental expertise  required in power plant siting is also
required to identify and assess  solid waste  disposal  sites.  Figure 2.14
presents a  logic  diagram of  an FGC waste  site  selection process.
      The  three  basic categories  of parameters  to consider  in disposal
and  land  reclamation site  evaluations are regulations,  engineering/
economics and  environmental.   Table 2.16 presents  a partial listing of
the  categories  and their respective  parameters.  The environmental
evaluation  process generically covers the methodology to  be  employed
to tabulate environmental  impacts.   In general,  the importance of
                                  2-103

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STEP1
PROBLEM
DEFINITION
t
w
STEP 2
SITE IDENTIFICATION
fc
w
STEP 3
SUCCESSIVE
SCREENING
^
w
STEP 4
COMPARATIVE
EVALUATION
             waste quantities
             and composition
•  storage volume
   available
•  environmental
   screens
   differential costs
          •  limits of disposal
             site search
•  minimum acceptance
   criteria
•  engineering/economic
   screens
•  environmental
   evaluation process
             base operating
             conditions
   identify a number of
   sites
   reduce sites to a
   few best
I
h-«
o
   select site
   exhibiting best
   balance of cost
   and environmental
   compatibility and
   meeting all regula-
   tory requirements
              regulatory
              requirements
                   MACRO SCALE
                   CRITERIA
                                                               MACRO SCALE
                                                               CRITERIA
                                                  INCREASING DATA BASE
          Source:   [100]
                                              Figure 2.14
                    FGC Disposal Site Selection
                    Process  Logic Diagram

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                                                       Table 2.16
                                    FGC Waste Disposal  Site  Evaluation Parameters
N3
I
           Environmental

 Air Quality
  -  dust  nuisance
 Aesthetics
  -  visual  sensitivity
  -  natural screening available
 Aquatic  Ecology/Water Quality
  -  impact  on  surface water
  -  impact  on  ground water
  -  sensitivity
  -  chemical releases via leachate
 Land Use
  -  present
  -  projected
  -  proximate
  -  ultimate
 Noise
  -  sensitive  receptors
  -  natural shielding
  -  transportation and operation
 Public Health and Safety
  -  fill  stability
  -  transportation disruptions
 Socio-Economic
  -  loss  of land productivity
  -  people  affected
  -  increased  value of reclaimed
    spoil lands
Terrestrial Ecology
 - critical habitat
 - threatened or endangered species
 - sensitivity of vegetation
     Engineering/Economic

Hydrology
 - flooding potential
 - surface water protection
 - ground water protection
Site Development
 - surface and subsurface
   drainage
 - capacity and topography
 - fill design
Transportation and Access
 - barge
 - railroad
 - truck
 - conveyor (belt or
   pneumatic
 - pipe
 - hauling distance
Geology
 - depth of overburden
 - ground water depth
 - soil types,  physical/
   chemical characteristics
 - need for impermeable liner
Treatment Equipment
 - compaction/grading
 - leachate
 - impermeable  liners
Land Availability and Cost
                                                                                                  Regulatory

                                                                                               Federal
                                                                                               See Figure  3.1
                                                                                               State
                                                                                               As Applicable
                                                                                             .  Local
                                                                                               As  applicable
      Note:
 This is a partial  listing   and  for  illustrative purposes only.

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environmental parameters relative to each other and the magnitude of the
potential impacts need to be assessed.  The Environmental Evaluation
Matrix (EEM) developed by Leopold et al.[101] is one example.
2.5.1.2  Rationale for Good Design/Good Practice
     Increasingly severe environmental and economic constraints place
enormous emphasis on planning the operation taking into account all the
constraints.  For optimum design/practice of FGC waste disposal,
important considerations are:
     a.  What environmental impacts could occur and must be mitigated
         if possible by design/practice?  The principal issues may
         include:
         •  Water-groundwater pollution by leachate; surface water
            pollution by runoff and/or leachate; increased water use;
            water pollution caused by dike failure or severe flooding.
         •  Air - fugitive emissions from exposed surfaces of ash
            or dry sludge; emission of gases.
         •  Land - constraint on future land uses; instability
            during operation.
         •  Other - hazards to personnel and equipment.
         Impact issues are discussed further in Section 2.4.8 and
         Section 4.0.  The only emphasis in this subsection is their
         importance on design of facilities.
     b.  Technical/economic consideration to optimize economics and
         maximize safety.   Basic approach may include:
         •  Maximization of density - compaction,
         •  Minimization of 1 indling - co-disposal of ash and sludge,
         •  Increase of density (solids content) to increase
            strength/stability and decrease compressibility,
         •  Increase of solids content to improve handling properties, and
         •  Stabilization of mixed wastes with additives to form dikes
            and consideration of a lining system, if needed, to contain
            wastes and prevent leaching and migration of pollutants.
                                   2-106

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     The overall objectives of  good design/practice are:
     •  Containment  of the wastes,  including leachate as  much as
        practicable.   Long term stability of the waste places in
        the disposal site is essential.
     •  Maximization of the amount  of wastes/unit volume.
     •  Minimization of handling problems.
     •  Facilitation of water recycle as much as practicable.
     •  Minimization of fugitive emissions.
     •  Prevention/elimination of operator/equipment hazards.
     Several researchers and designers have considered all these in
developing broad approaches.  FGD wastes can be broadly categorized into
three types reflecting differences in chemical and engineering proper-
ties.   (This is discussed in more detail in Volume 3.)  The basic
categories of FGD wastes are:
     •   Sulfite-rich wastes.  The particles are needles, platelets or
         agglomerates.
     •   Mixed sulfate/sulfite wastes.  The particles are needles,
         platelets or cleavage fragments.
     •   Sulfate-rich wastes which are needles or cleavage fragments.
     Coal ash (fly ash and bottom ash) does exhibit varying  character-
istics  but not in a manner as to permit analogous characterization.  Dry
disposal of ash, co-disposal of ash,  and FGD wastes  and  stabilization
processes for FGD wastes  (which usually employs  fly  ash  and  lime) are
likely  to be widely processed in future.  For  each of  the above  cate-
gories, a number of design/practice  choices  are  available.   Typical
questions defining the options  are:
      •  Pond wastes or compact  in  landfill?
      •  Dewater  or mix dry ash  with  FGD waste  for landfilling?
      •  For  dry  disposal,  lift  thickness  for compaction?
      •   Slope  angle vs.  slope height for dikes/fills?
      •  Use  of  stabilization of FGD wastes  for containment  dikes?
      •  Material for  liner if  needed; stabilized wastes, clay,  synthetic?
      •   Thickness  of  the liner?
      •  Monitoring methods and degree?
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     Some general comments on good design/good practice taking into
account the three categories of FGD wastes and the options defined
above are offered in the remainder of this subsection.  These are
broadly applicable but need to be modified in light of site-specific
considerations.

2.5.1.3  Sulfite-Rich Wastes
     For sulfite-rich wastes, if co-disposal is indicated, it would
appear to be advisable to convey low-solids sludge to a disposal site
and mix it there with dry fly ash, for a new plant without wet fly ash
transfer facilities.  It is not likely that sulfite-rich wastes would
be suitable for landfill except with stabilization; sulfite-rich wastes
are weak, compressible and susceptible to liquefaction under dynamic
loading.  Sulfite-rich wastes most likely would be ponded, injected
into deep mines, placed in surface mine pits and spoil banks particu-
larly with stabilization.  In the future, placement of FGC wastes in
managed fills is likely to be encouraged.  This may require stabilization
of sulfite-rich wastes in many cases.
     In any event, sulfite-rich wastes must be contained.  In ponds,
this would require use of soil or stabilized wastes in containment
dikes.  Use of soil to construct dikes is a common practice and requires
no innovation.  Use of FGD waste, FGD waste plus ash or stabilized
waste to construct dikes would require determination of FGD waste and
ash properties (shear strength parameters, compressibility, and permea-
bility as well as compaction behavior).   Good design would include
specification of slope angle as a function of proposed slope height
for containment dikes, with the function determined on the basis of
previous laboratory tests.  Containment dikes would be constructed in
lifts (layers), with compaction of the lifts to a density specified on
the basis of compaction tests.  The dikes would be used to support
deposited wastes but may require a lining to prevent passage of leachate.
Even an embankment built of stabilized sludge would contain cracks and
fissures, so a lining may be required or desirable.  The least expensive
lining would be a layer of plastic clay at least 24 inches thick
                                  2-108

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compacted at a moisture content well above optimum moisture content as
determined by Standard Proctor test (see Volume 3 for test references).
Placement of the clay on the inside of the dike would ensure that
seeping liquid would carry the clay into any cracks in the dike and
create a seal.  Compaction of the wastes themselves would not be possible
unless the sludge (or mix) were dewatered to a solids content of at
least 70% (indicated by tests in 1977-78 at Plant Scholz).  This does
not seem to be economically viable for most situations at the present
time.  Compaction would be advisable at a plant site if this operation
improved the waste behavior sufficiently to minimize environmental
impacts and/or permit a future use of the site which would return
revenues adequate to defray compaction costs, and the costs of prepa-
ratory dewatering.  It is doubtful that increase in density associated
with compaction in and of itself would be cost effective (through
increase in amount of waste placed on each unit of area).
     An important design consideration is to insure that FGC wastes
disposed of on land will remain ultimately stable even if inundated by
flooding or other conditions of sustained hydraulic discharge.  This is
particularly important if stabilized FGC wastes are employed as diking
or liner materials at the disposal site.  Regulations under RCRA on
this issue are under review.
     Good.design would include provisions for monitoring groundwater
quality and surface water quality.  Current EPA Guidelines [8] on this
issue were relaxed recently and would apply to FGC wastes [8].  Moni-
toring wells could be installed in such a way that if a leak were dis-
covered, the monitor well could be pumped to remove contaminated water.
The area of the disposal site could be graded to cause water  to flow  to
the locations of  the monitor wells.  The annular space between  the well
casing  (perforated) and the natural soil could be filled with sand-
gravel when the temporary hole casing  is in place so  that a  collection
zone was  formed around  the well pipe.  A layer of sand-gravel on  the
surface,  around  the well  pipe, could  channel  leachate to the well;  the
site  lining would then  be placed  over  the  sand-gravel collection zone.
If needed,  surface waters could be collected  within the disposal site;
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i.e., precipitation falling on the site could be collected by standard
temporary drainage control techniques employed at large-area construction
projects.  All contaminated waters would be retained for recycle and/or
treatment.
     To  facilitate uniform placement of wastes and recycle of super-
natent,  a floating boom could be employed.  The boom would be moved
daily  (or sooner) in a pattern devised prior to construction, to prevent
formation of large delta features.  At the present time, it appears
advisable to spread the wastes as thinly as possible to maximize de-
watering by evaporation and/or freezing-thawing cycles.  Consideration
should be given to depositing FGD sludge in thin layers between layers
of fly ash; the more pervious fly ash layers would serve as drainage
zones  to accelerate dewatering and consolidation of the sludge.  Layering
of ash between sludge also may increase the overall stability of the
wastes deposit, but detailed technical and economic evaluation would
be required prior to use of such a technique.
     Good design of a waste disposal facility would include planning of
temporary haul roads, usually included via the containment dikes, to
permit equipment access to all reaches of the disposal site.
     Also, provisions could be made to use some of the supernatent for
dust control in dry climates where spreading wastes in thin layers over
large areas could lead to fugitive emissions; a moisture content of
only 15-20% should be adequate for dust control.  If wastes are placed
in alternating layers (sludge, ash, sludge, ash...) the disposal opera-
tion should be designed so that sludge is placed over ash as soon as
possible; i.e., the time of exposure of unmixed ash should be minimized.
     During design of a disposal site, consideration should be given
to designing the placement stquence to meet site-specific needs:
placement on a small area to full depth within a short time to free
that area for another use; or placement of wastes first in those parts
of the disposal site farthest from the plant (source) to reduce the
burden (length of pipelines, pumping pressure, etc.) on aging transport
equipment; or use of land of least value first in hopes that technology
will change (no more scrubbing or sludge of better behavior or dry
wastes...) and more valuable land can be better used; etc.
                                 2-110

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     Hazards to personnel and equipment would be minimized by placement
of sludge in thin layers, compared to ponding to great depth very rapidly.
     Because of the nature of sulfite-rich wastes (weak,  compressible,
unstable), a general rule in design would be to use soil, stabilized
wastes or a mix of materials to contain unfixed materials and to rely
on the unfixed wastes to carry no load but rather to impose loads on
containment facilities.

2.5.1.4  Mixed Sulfite/Sulfate Wastes
     For mixtures of sulfite/sulfate wastes, it is anticipated that the
sulfite-rich materials will predominate or govern the behavior of the
mixtures in much the same way that silt-sized particles greatly influence
the behavior of silty sands.  Obviously, the degree to which the sulfite-
rich wastes influence the behavior of  the mixture depends on the sulfite/
sulfate ratio, but a minor fraction  (15-20%) of sulfite-rich wastes in
a mixture may virtually  govern the permeability, shear strength and
compaction behavior of the mixture  (these comments assume that the
sulfate-rich wastes will tend to  consist of  larger particles of more
equal dimensions as compared to sulfite platelets or  needles; if these
assumptions are at variance with  the actual  conditions at a given site,
the behavior of the wastes at that  site may  differ drastically from
that suggested here).  In a mixture, the smaller and/or weaker particles
will tend to govern behavior.  Mixtures of  sulfite-sulfate wastes
 (assuming the  sulfite  to be  smaller and weaker  particles) may closely
resemble  pure  sulfite-rich wastes in hydraulic  properties  (dewatering
and permeability)  and  may be much weaker and more  compressible  than
pure sulfate-rich  wastes.
     For  these reasons,  disposal  of mixtures of sulfite/sulfate wastes
may be  just as difficult as  disposal of  sulfite-rich wastes alone.
 2.5.1.5  Sulfate-Rich  Wastes
      Sulfate-rich wastes are usually larger in particle size,  with
 bulkier,  less  deformable crystals.   Such wastes should dewater suffi-
 ciently by  gravity drainage,  filtration,  and/or mixing with dry fly ash
                                  2-111

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to permit compaction of the material in self-supporting landfill
configurations.  Nevertheless, it may still be necessary to contain
leachate in site-specific instances.  Provisions for lining disposal
sites, collecting surface waters on-site, monitoring groundwater quality
and monitoring surface water quality should be considered in an analogous
manner to those employed for disposal of sulfite-rich wastes.
     In general, mixing FGD waste with ash may be beneficial for sulfite-
rich materials or mixtures of sulfite/sulfate wastes, but mixing ash
with sulfate-rich wastes may not be advisable unless site-specific
benefits of co-disposal justify such a practice.  It may be noted that
ash usually has higher levels of trace metals and hence an environmental
trade-off is involved in co-disposal.  That is, the leachate from co-
disposal would often be richer in heavy metals than FGD wastes alone.
2.5.1.6  RCRA and Planning FGC Waste Disposal
     The Resource Conservation & Recovery Act of 1976 (RCRA) is the
principal federal legislative framework impacting solid waste disposal
on land.  RCRA and other pertinent regulatory framework are discussed
in Section 3.   However, some comments on RCRA and FGC waste disposal
design/practice may be pertinent here.
     Proposed  regulations under the RCRA were issued on December 18,
     1978 [8],  and are under review.  Potentially, these could
     undergo significant modifications  prior to scheduled promulga-
     tion in December 1979.   The criteria for identifying hazard-
     ous wastes include characteristics such as ignitability,
     corrosiveness,  reactivity (e.g., strong oxidizing agents), and
     certain aspects of toxicity.   The  protocol for toxicity (which
     is the most pertinent to FGC wastes)  includes subjecting the
     waste to  an extraction procedure (EP), followed by chemical
     tests for metals and pesticides.
     Based on  RCRA guidelines published in December 1978, the steps
     to determine RCRA related requirements for FGC waste disposal
     are:
                                 2-112

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     a.   The  proposed  Extraction  Procedure  (EP)  specified  in  Section
         3001 protocol will be employed  on  each  FGC waste  to  deter-
         mine if  it  passes or fails  the  protocol.
     b.   If a waste  passes the tests,  there will be no  federal
         requirements  governing waste  disposal under  RCRA.  However,
         guidelines  are  offered under  Section 4004.   Individual
         states are  required to adopt  and enforce  Section  4004 to
         regulate FGC  waste disposal if  they  wish  to  receive  federal
         financial aid under Subtitle  D  of  RCRA.
     c.   If an FGC waste fails the tests, it  will  be  considered a
         special  waste.   Then, only site-selection, monitoring, and
         record-keeping  standards of Section  3004  (hazardous  wastes
         disposal) will  apply.  Design standards under  Section 3004
         as currently  proposed are not required  in any  case for FGC
         waste disposal.

2.5.2  Ocean  Disposal
     Ocean disposal  of FGC wastes is not now practiced.  Ongoing studies
and assessment are discussed  in  Section 2.3.   If at a future date ocean
disposal of FGC wastes is practiced, site selection,  design and practice
of the waste disposal  operation would  require considerations analogous
to those discussed for land disposal.   Engineering or design approaches
for ocean disposal require further study.
                                   2-113

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3.0  REGULATORY CONSIDERATIONS
3.1  Regulatory Framework Overview
     FGC wastes are generated when stack gas scrubbing is employed to meet
the requirements of the Clean Air Act as amended in 1977.  Once generated,
their transportation, handling, and ultimate disposal may be regulated
under a complex framework of environmental laws and regulations which are
implemented by different offices within an assortment of federal, state,
and local agencies.  The implication of the myriad regulations governing
FGC wastes is that removing contaminants from flue gas is not the ultimate
resolution of an environmental problem.  Rather, it is the transformation
of the problem into another form which, it is hoped, will be more manageable.
     The quantities of FGC wastes which will be generated in the future
depend critically on the implementation of two recent federal laws, the
Clean Air Act of 1977 and the National Energy Act.  The National Energy
Act is composed of five separate bills, of which the most significant in
relation to FGC waste generation are the Power Plant and Industrial Fuel
Use Act of 1978 and the Natural Gas Policy Act of 1978.
     Implementation and enforcement of the Clean Air Act is expected to
increase the quantities of FGC waste generated by reducing allowable
emissions of particulates and SO  for new power plants.  The solid waste
impacts of alternative levels of S0_ and control have been considered by
Leo & Rossoff [61].  Existing plants may also be affected by state
implementation plans for TSP and S02.  Additional generation of FGC
wastes bv tightening environmental regulations is thus likely.   Moreover.
low sulfur coal that now does not require desulfurization may require FGD
systems in the future.  Regulations under the Clean Air Act are expected
in mid-1979.
     The Power Plant and Industrial Fuel Use Act is expected to increase
the amounts of FGC waste generated by its prohibition of the burning of
oil and gas in new power plants, and by requiring some existing plants
to convert to coal from oil and gas.  The Natural Gas Policy Act will tend
to encourage the use of coal and oil by industrial users, by forcing the
greatest burden of natural gas price increases on industrial and utility
users, and by classifying them as lower priority than residential and

                                   3-1

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 agricultural  users  In the  event  of natural gas curtailments.  Some users
 may convert to  alternative fuels in  the face of high priced gas with an
 uncertain supply.  The implementation of NEA has barely begun, and any
 assessment of its impact on FGC waste generation is premature at this
 time.  The provisions of NEA are discussed in Power, October, 1978, pages
 68-70.  NEA strengthens the coal-conversion-forcing provisions of the
 Energy Supply and Environmental  Coordination Act of 1974 by transferring
 the burden of proof in any coal  conversion dispute from government to
 industry.  Under NEA, a utility must convert to coal unless it can demon-
 strate infeasibility.  Infeasibility may be based on fuel availability,
 site limitations, environmental  requirements, state and local requirements
 (e.g., building codes), etc.
     Most federal environmental  law enacted in this decade is implemented
 and enforced by the Environmental Protection Agency (EPA).  The EPA now
 has broad control over all "phases" of the environment:  air, water, and
 solid wastes.   It has been observed, since the passage of the Safe Drink-
 ing Water Act, and the Resource Conservation & Recovery Act, that EPA has
 authority to protect all phases of the environment in a balanced program
 via coordination of regulatory activity affecting several interacting media.
 Other branches of government,  particularly the Army Corps of Engineers,
 the Department of Labor, the Department of Transportation, the Department
 of the Interior, state and local governments maintain jurisdiction over
many activities which significantly affect the environment and FGC waste
 disposal.  In many instances,  these separate agencies attempt to coordi-
nate policies and regulations  affecting the environment, but organizational
mechanisms for effecting such coordination are absent or poorly defined.
     An emerging issue for environmental regulators is the total impact
 across all environmental media (air, water, land), and the human environ-
ment—including availability of energy and water,  and the social infra-
 structure—of regulatory action which specifically addresses a problem
 in one environmental "box."  For example,  does the treatment of water
effluents entail an energy cost,  with required generation of that energy
leading to more serious environmental and  economic problems?  Is S09 in
the air more detrimental to health than FGD sludge leachate and other
scrubber-related effluent streams?  Much environmental science, engineering

                                  3-2

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and regulation has been developed with an eye to a single environmental
compartment, for numerous reasons,  including the maturine of the environ-
mental sciences from media or discipline oriented specialties,  and the
topical nature of environmental problems.
     Recent environmental laws have different requirements for consideration
of cross-media and environmental impacts with the Clean Air Act having the
least requirements for such considerations.   Nonetheless, the laws implicitly,
and in some cases, require consideration of  economics, and several provide
mechanisms for consideration of related environmental impacts.   A coordina-
ted approach aimed at maximizing the total environmental benefits of a reg-
ulatory program will face technical, institutional, and budgetary constraints.
The technical and budgetary constraints are  closely related:  it is extremely
difficult to predict the gamut of environmental consequences of a specific
action; consequently, the cost of such an assessment is high.  In some
cases, the state of the art is not adequate  to predict the consequences,
regardless of cost and of available resources.

     Institutional constraints on a cross-media or "global" approach arise
where different departments, agencies, and offices are responsible for
specific environmental "boxes:"  air, water, solid waste, mines, waterways,
etc.  Since EPA has statutory authority in each of the major "boxes"—
air, water, solid waste—this agency has the greatest opportunity for a
"global" approach, but the establishment of interaction between offices
responsible for the separate media has been reported by some observers to
be a significant bureaucratic problem (Walsh, 1978, Science, V. 202,
p. 600).  The research arm of EPA (Office of Research & Development) has
adopted a "global" approach in evaluating total environmental impact on
an industry-by-industry basis with a goal of evaluating  the total impact
of specific actions, controls, etc.  This base of  information has expanded
over the last five years and is  gradually being reflected  in regulatory
policy.  Official mechanisms for incorporating a broad base of  cross-media
information to bear on the regulatory process have been  slow to develop,
and it  is likely  that  individual initiatives  continue to be the most
effective mechanism  for  coordinating regulatory  policy  to  the  end of
minimizing  total  cross-media environmental  impacts.
                                    3-3

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      Some exemplary provisions  of recent  environmental  legislation which
 force a cross-media approach include:
      •  The requirements of Sections  304  and 306  of  the Clean
         Water Act  (FWPCA)  that  EPA consider  "non-water  quality
         environmental impact (including energy  requirements)"
         in the establishing of  effluent limitations  and new
         source performance standards ,
      •  The requirement  of Section 1008 of the  Resource Conserva-
         tion and Recovery  Act that solid  waste  management guide-
         lines provide for  the protection  of  ground and  surface
         waters and  ambient air,  and
      •  The provision of TSCA which directs  the Office  of Toxic
         Substances  to consult with other  offices within the
         agency before formulating  regulatory strategy.
      It  is  recognized that in the  case of RCRA, the  Office of Solid Waste
 (OSW), has  responsibility  for all  media - a possible result is that OSW's
 air and  surface water related standards for disposal sites could be
 different  from other  federal or state standards for  the prevention of air/
 water  pollution from  types of facilities.   In some instances, this could
 potentially create jurisdictional  impediments in individual permitting
 actions.
     Figure 3.1 provides a "cradle-to-grave" schematic  of FGC waste gen-
 eration, handling, and disposal identifying federal  regulatory agencies
with jurisdiction over step processes which involve  changes in physical/
 chemical properties or location.   The right side of  the figure presents
 the federal regulatory authority with jurisdiction over that process.
     Ash and S0» removed from s. Lack gases  are not destroyed, but simply
collected and  transformed.  Based  on authority  derived  from the Clean Air
Act as amended  in 1977, EPA is requiring higher levels  of control of
particulates and SO-.  Based on authority derived from  the Federal Water
Pollution Control Act, also administered by EPA, some derivatives of these
wastes may not be discharged in appreciable quantities  to navigable surface
waters.  Recognizing  that only a small fraction of such wastes is put to
beneficial use  in the United States, land-based disposal is, indirectly,
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                    PROCESSES
        Waste Generation
         at  Power Plant
                           Waste Treatment
                             (Optional )
                            Waste  Storage
                             (Optional )
                           Onsite  Disposal
        Transportation  to
        Offsite  Disposal
                     Storage at  Site
                        (Optional)
                    Landfi11
                             M i n f;  Disposal
                                         n
ACE  - Army Corps of Engineers
DOI  - Department of Interior               '	
DOT  -^ Department of Transportation
EPA  - Environmental Protection Agency
MESA - Mine Enforcement &  Safety Administration
OSHA - Occupational Safety & Health Administration
 Ocean
Di sposal
             REGULATORY
             AUTHORITY

           EPA, OSHA
           EPA,  OSHA



           EPA,  OSHA, ACE



           EPA,  OSHA, ACE


           EPA,  OSHA, DOT



           EPA,  OSHA, ACE
EPA


EPA


EPA, MESA,  DOI


EPA, OSHA, DOT
                  Figure 3.1  FGC Wastes - Federal Regulatory Chart
                                      3-5

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 required  by  the laws mentioned  above  and administered by EPA  (OSHA also has
 regulatory authority over  issues  pertaining  to  the  safety and health of
 workers at the  generation  site, but this authority  is tangential to the
 issues highlighted here).
      Once generated, the wastes may be  treated  and/or temporarily stored.
 FGC  waste treatment is not directly regulated or required by law, although
 constraints  on  disposal of sludge encourage, and establish technical stan-
 dards for, waste treatment.   These constraints  on sludge disposal derive
 from existing regulations,  and  speculatively, from  anticipated waste dis-
 posal regulation.
      Temporary  storage, whether at the  point of generation, disposal or during
 interim transport, is regulated in much the  same way as disposal discussed below.
      Authority  to regulate the  transportation of wastes rests with the
 Department of Transportation, OSHA, and EPA  under a variety of laws, and there
 is little experience to indicate  how  presumptions of overlapping authority
 might be  resolved.  One relevant  example is  in  the  management of spills of
 hazardous materials in the nation's waterways where both EPA and the U. S.
 Coast Guard  (DOT) have statutory  authority:  EPA concentrates on identifica-
 tion of sources  and subsequent legal  action, while  the Coast Guard performs
 emergency response and clean  up.
      Most viable disposal  options  are land-based and there are numerous regula-
 tory bodies with authority over some  phase of land-based disposal.  The broad-
 est-based authority rests  with EPA and  particularly with the Office of Solid
 Waste which administers the Resource  Conservation and Recovery Act of 1976.
 The  Office of Solid Waste  Is  responsible for setting guidelines for state solid
 waste management plans, efficiency criteria for disposal of non-hazardous waste
 and minimum national standards for the handling of hazardous wastes.   It is also
 responsible for  deciding what constitutes a hazardous waste.  This decision is
 pertinent to the level of  control  required and the ultimate regulatory authority
 over  a given waste material:  the  states are the ultimate authority for the
 handling  of non-hazardous wastes, while OSW has much more direct control over
 hazardous waste  management.
      EPA also administers  the Safe Drinking Water Act (Office of Water  Supply)
 and the Federal Water Pollution Control Act (Office of Water Programs) which
 are significant  to land-based disposal of FGC wastes.  OWS sets national drinking
water standards and regulates the underground injection of fluids in wells.  The
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Office of Water Programs administers the national permitting authority
for point source waste discharges to navigable waters.   RCRA authority is
superceded by the Marine Protection Research & Sanctuaries Act,  the Hazard-
out Material Transportation Act,  FWPCA,  and SDWA for all activities and
substances covered by those acts.
     It should further be emphasized that the separate states all maintain
varying degrees of authority under all the federal environmental legisla-
tion highlighted above.  The states may administer state plans with relative
autonomy (e.g., non-hazardous solid waste management criteria where OSW defines
and prohibits open dumping, writes suggested guidelines and controls allocation
of funds to the states) or, at the other extreme, may administer a state pro-
gram which must be consistent with or more stringent than national standards
set by EPA.  Under all the important federal environmental statutes, EPA can
assume certain regulatory authority if the state neglects to implement and
enforce a plan or if the state's actions are inconsistent with the objectives
of the act, as interpreted by EPA.
     Other important federal statues which may be used to regulate disposal
of FGC wastes are the Surface Mine Control & Reclamation Act (administered
by the Office of Surface Mining, Department of Interior), the Dam Inspection
Act  (administered by the U. S. Army Corps of Engineers), the Federal Coal
Mine Health & Safety Act (Mining Enforcement Safety Administration), the
Occupational Safety & Health Act  (Occupational Safety & Health Administration),
and  the Hazardous Materials Transportation Act  (Department of Transportation).
     Of these the Surface Mine Control  & Reclamation Act is likely  to be
significant, based on  the  potential for diposal  of  sludge and ash generated
at mine-mouth power plants, during  the  reclamation  of surface mines.  The
authority of the Office  of  Surface Mining  is comprehensive, and  the proposed
regulations which have been generated to date  are similarly comprehensive.
The  OSM/DOI proposed regulations are different  from the OSW/EPA  regulations
in terms of definitions  and regulatory  strategy.  For example, definition of
"waste" and "toxic"  in the OSM/DOI  regulations  are  not  equivalent  to  those in
the  OSW/EPA regulations.   While  OSW/EPA regulations protect  "usable aquifers"
from "endangerment"  the  surface  mining  regulations  require  the protection of
"groundwater  systems"  from changes  in flow or  quality.   SMCRA does not super-
cede FWPCA, or the  Clean Air  Act.   Its  relationship to  RCRA is not spelled
out  in either  law,  although coal wastes are regulated  under MSCRA.
 An ultimate or joint authority over FGC waste disposal in surface mines has
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 not  been  fully  established at  this writing, making it difficult to assess
 the  regulatory  environment under which waste disposal in surface mines will
 occur.
     The  basis  for  the discussion to  follow is the existing and antici-
 pated  regulatory  environment governing the disposal of flyash and FGD
 sludges.  However,  the discussion of:  "Possible future regulations:  A
 focus  on  priority pollutants?" suggests a future solid waste disposal
 problem.  If removal of priority pollutants from waste water streams is
 required  in future  regulations pursuant to the settlement agreement and
 the  Clean Water Act of 1977, a number of potentially toxic metals initially
 cleaned from flue gas will be collected in solid form from wastewater "
 streams.  Disposal of these wastes would be regulated under RCRA, possibly
 under  the hazardous waste restriction of Subtitle C.  As is the case for
 other  constituents of flue gas, ultimate isolation of these chemicals
 from the  biosphere can only be accomplished through diligent controls and
 progressive immobilization.  All future initiatives to require more
 stringent control of air and water effluents must be considered in rela-
 tion to the solid waste impacts.
     The  discussion to follow is organized according to impact issues
 as listed in Table 3.1, which includes legislation directly relevant to
 the  various impact issues.
 3.2  Groundwater Related
     The most important federal laws  pertaining to potential groundwater
 contamination attendant to the disposal of FGC wastes are the Resource
 Conservation and Recovery Act of 1976 (RCRA), the Safe Drinking Water
Act  of 1974 (SDWA), the Surface Mining Control and Reclamation Act of
 1977 (SMCRA), and the Federal Water Pollution Control Act as amended in
 1977,  (FWPCA).
 3.2.1  Resource Conservation & Recovery Act and Anticipated Regulations
 3.2.1.1  Overview
     RCRA (PL 94-580)  provides for the regulation of the disposal of
solid and hazardous wastes.  The regulatory framework governing the dis-
posal of FGC wastes will depend on the classification of these wastes as
"hazardous" or merely "solid" (non-hazardous)  wastes.   Federal regulatory
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                              Table 3.1
                Regulatory Framework for Coal Ash and
                   FGD Sludge Disposal/Utilization
Impact Issue

Groundwater
  Contamination
         Legislation

   Resource Conservation
     and Recovery Act of
     1976
         Administrator

   Environmental Protection
     Agency, Office of
     Solid Waste
Surface Water
  Contamination
Physical
  Stability
                   •  Safe Drinking Water
                        Act of 1974
•  Clean Water Act
•  Marine Protection Research
     and Sanctuaries Act

•  Resource Conservation &
     Recovery Act of 1976

•  Surface Mining Control
     and Reclamation Act of
     1977
                      Dam Safety Act of 1972
                   •  Federal Coal Mine Health
                        and Safety Act of 1969
                      Occupational Safety and
                        Health Act of 1970
                      Hazardous Materials
                        Transportation Act of
                        1975
•  Environmental Protection
     Agency, Office of
     Water Supply

•  Environmental Protection
     Agency, Office of
     Water Programs

•  Environmental Protection
     Agency, Office of
     Marine Protection

•  Environmental Protection
   Agency, Office of Solid Waste

•  Office of Surface
     Mining Reclamation
     and Enforcement,
     Department of Interior

•  Army Corps of Engineers,
     Department of Defense

•  Mining Enforcement
     Safety Administration,
     Bureau of Mines,
     Department of Interior

•  Occupational Safety
     Health Administration,
     Department of Labor

•  Department  of  Transpor-
     tation
 Fugitive Air
   Emissions
   Clean Air Act of  1970
      and its Amendments of
      1977
 •  Environmental Protection
      Agency, Office of Air
      Programs
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                               Table  3.1   (Continued)

                Regulatory  Framework for  Coal Ash and
                   FGD  Sludge  Disposal/Utilization
Impact Issue

Fugitive Air
  Emissions
  cont'd
Marketing and
  Utilization
        Legislation

   Federal Coal Mine Health
     and Safety Act of 1969
                   •  Resource Conservation and
                        Recovery Act of 1976

                   •  Occupational Safety and
                        Health Act of 1970
•  Toxic Substances Control
     Act of 1977
    Administrator

Mining Enforcement
  Safety Administration,
  Department of Labor

EPA, OSW
Occupational Safety and
  Health Administration,
  Department of Labor

Environmental Protection
  Agency, Office of
  Toxic Substances
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authority is more comprehensive for the former:   standards for generators,
transporters, and operators of disposal facilities will be more stringent;
and disposal of hazardous wastes is expected to  be substantially more costly [45]
     RCRA is intended to ensure a broad multi-media approach.   The overall  in-
tent is to integrate  to the maximum extent practicable all provisions of RCRA
with appropriate provisions of the other Acts of Congress which give EPA
regulatory authority.  One of the ways EPA has chosen to integrate RCRA with
the Safe Drinking Water Act (SDWA), the Clean Air Act (CAA), and the Clean
Water Act (CWA) is through the use of Human Health and Environmental Standards.
Each of them -  the groundwater, surface water, and air standards - establishes
an overriding standard for treatment, storage, and disposal facilities by in-
corporating relevant limitations established under those acts.

      Solid  wastes  are defined  in  Section  1004 of  the  act  as "any  garbage,
 refuse,  sludge  from  a waste  treatment  plant, water  supply treatment  plant,
 or air pollution  control  facility and  other discarded material resulting
 from industrial... operations...  but  does not include...  industrial  dis-
 charges which  are  point  sources  subject  to permits  under  Section  402 of
 Federal Water  Pollution  Control Act  as amended..."
      Hazardous  waste is  defined  in the same section as "a solid waste,  or
 combination of  solid wastes, which because of its quality, concentration,
 or physical,  chemical,  or infectious characteristics may:
      a.  Cause, or significantly contribute to  an increase in
          mortality or  an increase in serious irreversible, or
          incapitating reversible, illness; or
      b.  Pose a substantial present or potential hazard to human
          health or the environment when improperly treated,
          stored,  transported or disposed of, or otherwise managed."
      Subtitle C of the Act - Hazardous Waste Management - requires the
 EPA to promulgate regulations identifying the characteristics of hazar-
 dous waste and to list specific hazardous wastes "taking into account
 toxicity, persistence, and degradability in nature, potential for accumu-
 lation in tissue, and other related factors such as  flammability, corros-
 iveness, and other hazardous characteristics," (Section  3001  (a)).

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     Regulations attendant to Subtitle C were proposed on December 18,
 1978.  These are proposed regulations and may be modified prior to prom-
 ulgation by December 1979.  There are two separate, but related, issues
 involved in determining whether a waste will be regulated, under Sub-
 title C, as hazardous:
     •  Identifying the characteristics of hazardous wastes, and
     •  Listing specific wastes as hazardous.
     According to the December 18, 1978 [8] draft, the Office of Solid
 Waste will regulate on the basis of both the list of hazardous wastes and
 the characteristics.  If a waste is listed, it is presumed to be hazardous.
 If a generator believes that his listed waste is not hazardous, the burden
 of proof falls on him to demonstrate that it is not hazardous according to
 its characteristics.  On the other hand,  if a waste is not listed but the
generator has reason to believe his wastes are hazardous,  he is required
 to test these wastes for the suspected failing characteristics.   It is
anticipated by the EPA that many utilities will test their wastes to
determine whether or not they can be considered hazardous  under the
regulations.
     FGC wastes are not listed as hazardous in the December 18, 1978,
 proposal.  However, in the section entitled "Standards for Owners and
Operators of Hazardous Waste Treatment,  Storage, and Disposal Facilities,1?
 section 250.  46-2 defines a limited subset of these regulations which are
applicable to "any utility waste* which  is defined as a hazardous waste
under Subpart A" where Subpart A is the proposed regulations pertaining to
identification and listing of hazardous wastes.  This subset of regulations
will be discussed in more detail below.   The key issue here is whether this
 specification of utility wastes as a special waste in the hazardous waste
regulations is sufficient grounds to say that generators of these wastes
 (utilities) "know or have reason to believe" that their waste may be
hazardous.  In that case, utilities would be required to test their waste
and report these tests to EPA.  Otherwise, FGC wastes would effectively be
 exempted from hazardous waste regulation under Subtitle C.
* Utility waste is defined as fly ash, bottom ash, and flue gas
  desulfurization sludges.
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     The December 18,  1978,  proposal for identifying the characteristics
of hazardous waste defined a number of standard protocols.   The most
important one for FGC wastes is the Extraction Procedure (EP)  for obtain-
ing a leachate elutriate.   If the elutriate contains any substance for which
a. threshold has been established, then the waste is hazardous.   Interim
threshold standards have been set for As, Ba, Cd, Cr, Pb, Hg,  Se, Ag and
several pesticides based on the National Interim Primary Drinking Water
Standards.  It is expected that in the future, thresholds will be established
for other contaminants.  Test programs have been ongoing at Oak Ridge
National Laboratory [46].   It appears [42] that preliminary tests on some
TVA Shawnee ash samples indicate that these samples can potentially pass
these tests.  The proposal also indicates that other water quality criteria
(e.g., those for protection of aquatic organisms) are being considered for
future use in conjunction with the EP.  Figure 3.2 outlines the schematic
as regards FGC wastes in terms of regulatory requirements under RCRA.  Under
the special waste provision, engineering standards for  disposal of hazardous
wastes under Section 3004 as currently proposed would not apply to FGC
wastes until such time as specific standards are promulgated for  those wastes.
     One possible course of event  in response to these regulations is that
individual utilities around the country would test their wastes according
to the EP, and some of these tests would indicate that  the wastes have the
characteristics of a hazardous waste.  If a substantial portion of a particular
waste is defined by EPA as hazardous, it would be expected that EPA would
then list that waste as hazardous, and all such wastes would have to comply
with the limited set of regulations  identified in 250.46-2, and the complete
set of regulations when they are ultimately promulgated  (unless a generator
demonstrates that his particular waste is not hazardous).
      EPA is also charged with establishing legally  enforceable standards
applicable to generators and transporters of hazardous waste and  to
hazardous waste management  facilities.   Facilities which treat,  store,  or
dispose of hazardous waste  must  have permits,  either from EPA  or  a  state
hazardous waste program authorized by EPA.
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                       FGC WASTES
                      TESTS UNDER
                        SEC. 3001
                       PROTOCOL
 NOTE: TOXICITY TESTS ARE
      MOST IMPORTANT
   SEC. 4004
 REQUIREMENTS
   SEC. 30O4
    SPECIAL
    WASTES
(STATE IMPLEMENTATION
 OF FEDERAL STANDARDS)
     CATEGORY
(FEDERAL STANDARDS)
            Figure 3.2  Regulatory Requirements - RCRA
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3.2.1.2  The Act
     It is the intent of the act to establish national standards  and
criteria, but that the individual states  would implement and  enforce  the
regulatory program.  However, in the event a state does not become authorized
to conduct the hazardous waste program in that state,  EPA will conduct the
hazardous program in that state.  Wastes  which are identified as  hazardous
are to be regulated more stringently at the federal level than non-hazardous
solid wastes.  Where RCRA calls for EPA to establish legally  enforceable
standards for the management and disposal of hazardous wastes, non-hazardous
waste management and disposal is to be regulated by criteria, which are not
federally enforceable at least by mechanisms clarified at present.  State
programs for the management of hazardous waste must be equivalent to the
federal program, consistent with federal or state programs in other states,
and must provide for adequate enforcement.  On the other hand, state plans
for solid waste management must meet only certain minimum requirements,
including prohibition of open dumps, as defined by EPA and implementation
of the federal Management and Disposal criteria, and the establishment of
necessary state regulatory powers.
     The most important requirement in the area of non-hazardous solid
wastes, as it pertains to groundwater contamination from the  disposal of
FGC wastes,  is  the prohibition  of open dumps.
     An open dump  is defined in the act by exclusion, as any  site where
solid waste  Is  disposed of which  is neither  a sanitary  landfill nor a
facility for disposal of hazardous waste.  A facility qualifies as a
sanitary landfill  if there  is no  reasonable  probability of adverse effects
on health or the environment from disposal of solid waste at  the  facility.
The only action which can be taken by the federal  government  to  encourage
state  participation  and  compliance with  non-hazardous waste  regulations  is
in  the distribution  of  funds to the states.   $11.2 million are appropriated
for  state  solid waste plans for fiscal 1979.
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3.2.1.3  RCRA Regulations
     The Act is to be administered by the Office of Solid Waste (OSW) of
the EPA, and that office is in the process of developing regulations
required under the Act.  On February 6, 1978, OSW published in the
Federal Register proposed rules containing criteria for determining
which solid waste disposal facilities shall be classified as sanitary
landfills, as defined in the Act.  It can be expected that these rules
represent the minimum level of control considered acceptable by EPA for
FGC waste disposal.

     EPA points out the potential for confusion in the use of the term
sanitary landfill, which traditionally refers to a practice for the con-
trolled burial of solid wastes, especially municipal wastes, whose primary
purpose was disease vector control and for aesthetic value.  The defini-
tion contained in the Act is much broader, not only in its definition
of solid wastes but also in the environmental performance requirements of
a sanitary landfill.  This is to be accomplished under the proposed rules,
by requiring that usable aquifers* not be endangered beyond the property
boundaries.   Endangerment is defined as the introduction of any physical,
chemical, biological, or radiological substance or matter into groundwater
in such a concentration that:    (1) makes it necessary for a groundwater
user to increase treatment of the water (including treatment to meet any
maximum contaminant level set forth in any promulgated National Primary
* an aquifer is "a formation... that contains sufficient saturated permeable
material to yield or be capable of yielding significant quantities of water
to wells or springs" and is usable as a drinking water source  if  it contains
less than 10,000 mg/1 IDS  (al.lough states may reclassify aquifers as usable
or unusable) defined in proposed regulations for the state underground  in-
jection control program, Federal Register, August 31, 1976, by the Office of
Water Supply, Use of this  definition by the OSW in  the administration of RCRA
is a good example of coordination of regulatory strategy within EPA.
                                  3-16

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Drinking Water Standard under the Safe Drinking Water Act),  (2)  makes it
necessary for a future user of the groundwater to use more extensive
treatment of the water than would otherwise have been necessary  (based
on current technology), or (3) otherwise makes the water unfit for human
consumption.  To assure that usable aquifers are not endangered  the pro-
posed criteria specify that one of the two following procedures  should
be followed:
     a.  Collection of leachate through artificial liners with subsequent
         removal, recirculation or treatment; or
     b.  Control of the migration of leachate by utilizing natural hydro-
         geologic conditions, or soil attentuation mechanisms.  Whe^e
         appropriate, infiltration of water into the solid waste shall be
         prevented or minimized.
Furthermore the rules call for monitoring of groundwater, and prediction
of leachate migration for as long as leachate may endanger groundwater.
     Solid waste disposal facilities shall not be located in the recharge
zone of aquifers which are the sole or principal source of drinking water
in the area unless no other sites are technologically or economically
feasible and the facility is located, designed, constructed, operated,
maintained, and monitored to prevent endangerment of the aquifer.
These  proposed criteria for  the  classification  of solid waste disposal
facilities  are currently  under review by  OSW  pending final promulgation.

Hazardous Waste
     The Office  of Solid  Waste is currently considering key regulations
applicable  to owners  and  operators of hazardous waste management  facili-
ties and regarding the criteria  for  identification  of the characteristics
of hazardous wastes  and the  listing  of  specific hazardous wastes.
     There  are several key  provisions relevant  to  FGC waste disposal.
Under  Section  3001 of RCRA,  EPA-OSW  will  define hazardous wastes  by two
methods:
     • Identifying  the characteristics of a  hazardous  waste, and
     • Listing  specific  wastes  as hazardous.
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      For all practical purposes, listed wastes are presumed hazardous
 unless proven non-hazardous by the generator, while unlisted wastes have
 to be tested by the generator if he has reason to believe that the waste
 is hazardous.  However, it is difficult to establish what someone "knows
 or has reason to believe" and this section may be difficult to enforce.
      The characteristics of a hazardous waste identified  by EPA for
 immediate regulatory control are ignitability,  corrosivity,  reactivity,
 or toxicity of these,  the toxicity test is the most critical one with
 respect to FGC wastes [48].   The toxicity test begins with the Extraction
 Procedure (EP) which is described in greater  detail in Volume 3,  and  which
 consists of:
      •   Filtration or centrifugation,  save liquid.
      •   Grind or hammer* solid residue.
      •   Extract in water of  pH 5  (but,  using  no more  than 4  ml of
         .5N acetic acid per  gram  of  solid).
      •   Recombine extract with liquid  from Step 1.
      A joint  ASTM/DOE  collaborative  test program  is also  being designed
 to evaluate leaching procedures.
      The waste would be considered hazardous  if the extract contains
 concentrations of any  substance in excess of  an established threshold.
 Thresholds have been established  for As, Ba,  Ca, Cr, Pb,  Mg, Se, Ag and
 certain pesticides based on EPA National Interim Primary Drinking
Water Standards.  The  thresholds have been set at 10 times the drinking
water standards.  Some tests on FGC wastes using the Extraction Procedure
 (EP) has been conducted for the EPA by the Oak Ridge National Laboratories
 (ORNL) [115].  Tests appear to indicate that EP is effective in removing
inorganic species but not effective for organics.   At least one sample
of fly ash seems to pass EP tests [42],  Thus, it is likely that some
FGC wastes would be considered hazardous by this criterion.
 *This requirement would have some bearing on  the acceptability of
 treated FGC wastes, where the most beneficial effect of  treatment may
 be the reduction in permeability.  If the waste was structurally weak
 and  thus vulnerable to the hammer test, this benefit would be discounted
 in the evaluation of hazardous characteristics.

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     Because many FGC wastes have not yet been fully tested and are
temporarily considered "special wastes?" it is impossible to ascertain
whether such wastes will be regulated as hazardous or non-hazardous.   If
found non-hazardous, the wastes would be regulated under Sections 1008
and 4004 of RCRA.  However, if specific wastes are tested and found to
have the characteristics of a hazardous waste as stated earlier, a limited
subset of disposal procedures will be required as specified in Section 250.46-2
(Utility wastes) of the regulations.   (See Figure 3.2.)  Utility wastes means
fly ash, bottom ash, and FGD sludges generated from steam electric power plants.
     All storage and disposal facility operators must provide detailed
physical and chemical analysis of each waste stream handled which identifies
the hazardous characteristics of the waste, once, when the facility starts
handling the waste and periodically thereafter.
     New facilities shall not be located in:
     •  An active fault zone,
     •  A regulatory floodway (as designated by the Federal
        Insurance Administration),
     •  A coastal high hazard area (unless the facility is built
        so as to be safe from hurricane and tsunami waves),
     •  a 500 year flood plain  (unless built such that the facility
        will not be inundated by a 500-year flood) ,
     •  Wetlands (unless the facility obtains a NPDES permit and
        a Section 404 permit for dredging or filling) ,
     •  A Critical Habitat Area under the Endangered Species Act
        of 1973  (unless it can be demonstrated that  the facility will
        not jeopardize  the continued existence of the endangered and
        threatened  species), and                       :
     •  The recharge  zone of a  sole  source aquifer  (unless located,
        designed, constructed,  operated, and maintained  to prevent
        endangerment  of the aquifer).
Security provisions also exist  for such  sites, including  a  6-foot  fence
surrounding  the active  disposal areas,  and  a  200-foot  buffer zone
requirement.
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      Generators, transporters, and disposers of hazardous wastes  are
 required to keep a manifest and recordkeeping system.
      Post closure care of a hazardous waste facility shall be continued
 for a maximum of 20 years (less if the owner or operator can demonstrate
 that such care is not needed).  The most significant requirements for  post
 closure care are monitoring for migration of waste constituents and the
 uncertain financial liabilities associated with potential ultimate disposal
 requirements.
      A groundwater monitoring system of four wells is  required (less if
 there is no potential for discharge to a usable aquifer).   One of these-
 wells must be upgradient of the site.   Baseline monitoring must be per-
 formed for at least 3 months prior to startup of any new facility.  The
 frequency of analysis of groundwater samples varies from one to four
 times per year depending on groundwater flow rates.  A depth of about
 1.5 meters (5 feet) from liner bottom to groundwater is required.
      If the monitoring indicates that significant contamination has
 occurred,  the operator must notify the EPA,  determine  the cause and extent
 of  contamination,  and discontinue operation until the  problem is  corrected.
 Removal of waste,  redesign of liner or other engineering and operational
 corrective actions may be required.
 3.2.2   Safe Drinking Water Act/Underground  Inspection Control Program
     This discussion of  the  Safe  Drinking Water Act  is  limited to the
 underground injection  control program  because this is a potential disposal
method  for FGC wastes.   The  Office of  Water  Supply  (OWS) of EPA is to develop
 regulations for state  programs covering  the  underground injection of wastes
via wells for the purpose of protecting  groundwater sources of drinking water
 EPA has interpreted well  mjec ion  to  include "subsurface emplacement
 through a bored, drilled, or driven well or  through a dug well where the
depth is greater than  the largest su.face dimension, whenever a principal
function of the well is  the  subsurface emplacement of fluids." (September 23
1977, draft of proposed regulations).  EPA must decide which states require
an underground injection control program, and has decided to concentrate
initially on states in which underground injection is commonplace and
groundwater drinking supplies may be endangered, .with subsequent regulation
nationwide.  State programs:

                                  3-20

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     •  May authorize underground injection either by permit or rule,
     •  Must provide for the protection of drinking water sources,  and
     •  Must provide for inspection,  monitoring,  record keeping, and re-
        porting requirements.

     The states have primary authority for enforcement, but if the EPA
finds that the state is not enforcing the regulations, EPA assumes en-
forcement responsibility.  Draft proposed regulations (September 23, 1977),
define and prohibit endangerment of usable aquifers and require plugging
of wells within a radius of endangering influence from the injection well,
and generally require procedures to insure that injected wastes will not
migrate from the level of injection upward into a usable aquifer.  The
regulations will not substantially restrain the underground injection
of wastes in new wells since they reflect present day best operating
practices.
     Based on discussions with EPA, Office of Water Supply, and related
proposed regulations under SMCRA and RCRA, it appears unlikely  that State
Underground Injection Control Programs under SDWA will be used  to regu-
late mine disposal of FGC wastes.  The Office of Surface Mining apparently
intends to regulate these activities under SMCRA, while the RCRA defini-
tion of disposal includes injection of wastes.  Thus, there are several
federal laws which may be interpreted to  regulate the injection of FGC
wastes in mines, i The Office of Water Supply has indicated  that it does
not intend to regulate this activity under SDWA, and apparently OSM or
OSW will regulate this disposal option.
3.2.3  Surface Mining Control and Reclamation Act
     The Surface Mining  Control and Reclamation Act of  1977 is  discussed
more extensively below.  Only its pertinence to groundwater contamination
resulting from FGC waste disposal is discussed here.   Among the expressed
purposes of SMCRA is  to  "assure  that surface coal mining  operations are
so conducted  as to protect  the environment".  Throughout  the  Act,  ground-
water  is specifically identified  for protection via permit and reclamation
programs.
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     Reclamation plans must:
     •  Show consistency with local physical environmental and climatolo-
        gical conditions,
     •  Contain the results of test borings or other equivalent information
        showing the location of subsurface water, and
     •  Contain a detailed description of measures to be taken during
        the mining and reclamation process to assure the protection of:
        - the quality and quantity of surface and groundwater systems, and
        - rights of present users to such water.
     Reclamation operations must be conducted to prevent long term adverse
changes in the hydrologic balance.  Specifically, this would include
changes in water quality and quantity, depth to ground water and changes
in the location of surface water during leaching.  Applicable state and
federal regulations have to be met as well.  It is suggested in this
standard that water pollution treatment methods can be used but this has
to be secondary to reclamation practices that prevent any of the above
adverse affects.   There is a minimal list of such practices, some of
which include lining drainage channels, revegetating, burying and sealing
acid-forming, toxic-forming material, etc.   The major issue is whether
or not using sludge material as fill would prevent meeting these specific
requirements of this standard.
     Specific detailed requirements  are given for sedimentation ponds
which must  be used  to collect  all surface  drainage  from distributed  areas
due  to mining or reclamation until  drainage  from the disturbed  area  has
met  the applicable water  quality  requirements.   The  effluent  limitations
listed in these regulations include maximum  allowable  and  daily average
values for  iron, manganese, total suspended  solids,  and pH.   These are
minimum standards and it  is not clear what additional  ones might be  used  or
how  the Office of Surface Mining  might view  such  standards in terms  of
disposal of waste  materials as fill.  It  is noted that state and federal
regulations  also apply.
                                  3-22

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     Any acid or toxic materials must be buried and treated when necessary.
Further, water must be removed from contact with such materials.  Surface
water monitoring is required after reclamation, with the regulatory
authority determining the scope and frequency and length of data collection.
Backfill materials have to be placed so that adverse affects on ground
water flow and quality are minimized.  It appears that offsite effects
are the ones of concern, although there is no indication of the classi-
fication of ground water systems in these regulations as was found in
RCRA regulations.  Monitoring of ground water levels and infiltration rates
is required.  Additional standards are included for alluvial valley floors,
roads, and permanent impoundments.

     Mining operations west of 100° west longitude must not materially
damage the quantity or quality of surface and underground water systems in
alluvial valley floors.  It is not clear whether FGC waste disposal in
surface and underground mines will be regulated under SMCRA, RCRA or
both.
     Another unresolved issue is  the potential  inconsistency in ground-
water protection between SMCRA and SDWA.  Regulations promulgated by  the
Offices of Water Supply and Solid Waste of  EPA under  SDWA  and  RCRA have
adopted the philosophy of protecting only usable aquifers  from "endanger-
ment"  (as defined  on page 4).  The Office of Surface  Mining, on the
other hand, has written regulations which protect  "groundwater systems"
from changes  in  flow and quality,  apparently including  both usable and
unusable aquifers.  Resolution of these  issues pends  further action by
the  Office  of  Surface Mining.
3.2.4   State  Regulations                              .
      The separate  States have administrative power over state programs
required under RCRA and SDWA,  so long  as  they meet minimum requirements
established by EPA.   Since  it is the intent of OWS not  to regulate FGC
wastes  under this  program,  the state programs were not  reviewed for this
study.  However,  an earlier review revealed that most state programs are
inconsistent with the proposed federal program and are understaffed  for
 enforcement.   To our knowledge,  none of these state programs have con-
sidered the regulation of FGC wastes via underground injection.

                                   3-23

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      State  solid  waste programs  are reviewed  in  greater detail below
 where the emphasis  is on surface water  related issues.  It  is of  interest
 then,  to  note  that  all state  solid  waste  programs  reviewed  apply  equally
 to  surface  and groundwaters,  via definitions  that  "waters of the  state"
 include surface and groundwaters.
 3.3  Surface Water  Related
 3.3.1 Introduction
      Several unresolved issues dominate the present  status  of surface-
 water-related  regulations potentially applicable to  land-based FGC waste
 disposal.   This is  not true for  ocean disposal,  where relatively  well-
 defined regulations exist for dumping from vessels (under the .Marine
 Protection  Research and Sanctuaries Act)  for  outfall disposal (under  the
 Federal Water  Pollution Control  Act Amendments of  1972 and  1977), and for
 artificial  reef construction  (discussed below).  Principal  unresolved
 issues for  land disposal  are:
      •  Distinctions between  definitions  of "point"  versus  "non-point"
        sources of  water  pollution;
      •  Establishment  of  a clear hierarchy of regulation integrating  the
        requirements of RCRA, FWPCA, and  SMCRA;  and
      •  Response  to the remand of EPA's proposed Effluent Guidelines  for
        the utility industry.
      The importance of  these  issues may be made  apparent by the following
 illustrative questions, none  of  which can  be definitively answered at
 this  time.
     1.  What surface water discharge criteria apply to a landfill of
         FGC waste on utility plant site?
     2.  What surface water discharge criteria apply to an impoundment
         of FGC waste at a location remote from a utility plant?
     3.  What surface water discharge criteria apply to FGC waste disposal
         in a surface mine?
     If FWPCA considerations for disposal at remote  (off-plant)  locations
requires  the development of new types of National Pollutant Discharge
                                 3-24

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Elimination System (NPDES) permits, the manner in which such permits
will be defined for various FGC waste disposal options will be signifi-
cant.  It is not clear which disposal options would be considered "point
sources" subject to such permitting, and which, if any, would be consid-
ered exempt as "non-point sources".  The same issue is further complicated
for disposal in surface mines, which, if allowed, might involve independ-
ent regulation of drainage from "non-point source" disposal areas by
OSM, as well as or in place of "point source" regulation by EPA.
     This background of emerging and shifting policies and responsibili-
ties needs to be kept in mind when reviewing the detailed discussions of
individual regulations below.
3.3.2  Surface Water Quality Issues from Point Source Discharges
3.3.2.1  Federal Water Pollution Control Act.
     The Federal Water Pollution Control Act established the NPDES permit
program.  States may administer their own NPDES program based on EPA
determination that the program  (a) will ensure compliance with  the Act,
(b)  is authorized under state laws, and  (c) provides  for adequate enforce-
ment.  An NPDES permit is required  for any point  source discharge into
navigable waters.  The permit sets maximum permissible effluent levels
for  specific pollutants which are  established  on  a  case-by-case basis
(in  some cases, however, national  Effluent Guidelines apply  to  various
aspects of  the NPDES permit).   The permittee  submits  monthly reports of
waste water analyses.
     Promulgated EPA guidelines covered  effluent  discharges  from various
sources within a power plant,  including  fly ash  transport water and
cooling  tower blowdown, but  effluents  from FGD systems were  not regulated
separately.  A summary of  the regulated  parameters  is given  in  Table 3.2.
It is  important  to remember  that  certain aspects  of these  guidelines were
challenged  in  litigation  and are  presently on remand, with revisions
reportedly  expected  in early 1979.  This is  discussed more fully in
 Section 4.1.4  of Volume  2.
                                   3-25

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                                  Table  3.2
   Effluent Parameters Subject  to  Effluent Guidelines  Limitations  for  the
                 Steam Electric Power Generation  Category
                                  Maximum Daily           30-day Average
BAT
TSS                                  100                         30
Oil and Grease                        20                         15
Copper                                 1                          1
Iron                                   1                          1
Free Chlorine                          0.5                        0.2

BAT
As above plus
Phosphorous                            5                          5
(TSS in rainfall run-off to be limited to a maximum daily of 50 mg/Ji.)

 Not all effluent sources subject to all the parameter limitations.
 See discussion of remand decision in Section 4.1.4 of Volume 2.
 Source:   [49]
                                   3-26

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     Copper and iron levels from boiler blowdown were covered but metals
in ash transport water were not regulated.   BAT regulations,  which must
be met for all power plants during the period 1984-1987,  and  New Source
Performance Standards, were similar to current BPT regulations, but with
the addition of regulation of phosphorous levels.  In addition, the reg-
ulations limited run-off from material storage and construction to maxi-
mum daily TSS of 50 mg/£.   Other provisions of FWPCA pertinent to power
plants are discussed in Section 4 of Volume 2.
Pollutants Potentially Regulated by Drinking Water Criteria
     Data from ten samples of unstabilized FGC waste from eastern and
western coal are given in Table 3.3.  It shows the constituents obtained
from the initial leachate from the base of the pile compared to the
corresponding drinking water criteria.  All of the elements analyzed and
TSS exceeded the drinking water criteria but not by more than a factor
of 10, with the exception of TSS.  Two samples exceeded the range 5-9
for pH.  Limited data showed that barium exceeded the drinking water
criterion by a factor of 5, nitrate was at the criteria level and silver
was 0.5 times the criteria level.  COD in fresh sludge ranged from 40-
140 mg/jt.  It was high for sulfite sludge but this sludge also showed more
rapid oxidation, and  after one pore volume displacement had a COD of 10 mg/&
or less.
Pollutants  Not Presently  Regulated

     The major potential pollutants typical of FGC waste effluents and
not presently regulated by effluent guidelines include dissolved solids,
(e.g., Ca and SO,) and trace metals, which can exceed water quality
criteria prior to mixing.
Non-Point Source Discharges
     Potential environmental problems associated with disposal of FGC
wastes by landfill include groundwater and surface water contamination
from leaching of dissolved solids  and trace metals.  Most state  regula-
tory authorities are  authorized  to protect sub-surface waters  but  only
a few states have  specific criteria for  groundwater  protection.   Appli-
cable criteria  for Missouri  and  New York are  shown  in  Tables 3.4A and B.  The
criteria  for TDS are  lower than  reported concentrations  of  dissolved solids
in leachate from unstabilized  FGC  waste  piles.
                                 3-27

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oJ

 O
                                                       Table 3.3

                                     Comparison of FGC Waste Liquids with Water Criteria
Drinking
Water
Criteria
mg/Jl
As 0.05
Cd 0.01
Cr 0.05
Pb 0.05
Hg 0.002
Se 0.01
F 2
TDSb
pH (actual
i \ C
vt lues)1-
Range of
All
Samples A
<0.8-2.8 0.6
0.4-11 5.0
0.22-5 5.0
0.2-6.6 0.8
0.03-2.5 2.5
0.28-63 10.0
<0.5-5
6.L-48.5 36
6.7-12.2 6.7

Concentration - Criteria (Nondimensional)
Sample3
B C
0.4 2.0
1.2 0.4
0.8 1.8
3.0 4.6
—
3.3 10.0
0.5 3.3
6.6 30.0
6.8 8.0

D B
0.04 0.4
11
0.6
<0.2 6.6
<0.1 <0.5
4.2 <2
1.7
13.4 18.8
12.2 8.7

F G H
1.2 2.8 0.1
1.3
0.2
0.2 <0.2 <0.2
<0.001 <0.1 <0.1
7.8 63 14
1
20.5 28 18.4
8.0 7.8 7.3

I J
0.8 0.2
5 2.5
1.1
0.8 <0.1
0.1 0.03
2.8 0.3
5 <0.5
8.4 48.5
10.7 8.9

a
Sample data are as follows:
Sample
A
B
C
D
E
F
G
H
I
J
Station
Mohave
Cholla
Shawnee
Shawnee
Shawnee
Shawnee
Shawnee
Shawnee
Duquesne Phillips
LGE Paddy's Run
Absorbent
Limestone
Limestone
Limestone
Limestone
Lime
Lime
Lime
Gypsum
Lime
Carbide Lime
% Ash
3
59
40
6
40
6
6
6
60
12
Sampling Data
Mar 1973
Nov 1974
Jun 1974
Jan 1977
Jun 1974
Sep 1976
Oct 1976
Aug 1977
Jun 1974
Jul 1.976











          Assumed 500.
         cPrlmary water supply criteria for most states are in ranges of 6.5 to 8.5 or 5 to 9.
        Source:   [50]

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U)
 I
ho
                                                                            Table  3.4a

                                                     Discharge  Criteria  in New  York and  Missouri
                                               State of New York*
                                        Groundwater Contaminant Limits
             State of Missouri
       Groundwater Contaminant Limits
Concentration in mg/i
Substance
Alkyl benzene sulfonate (ABS)
Arsenic (As)
Barium (Ba)
Cadmium (Cd)
Carbon chloroform extract
residue (CCE)

Chloride (Cl)
Chromium (hexavalent) (Cr-rt)
Copper (Cu)
Cyanide (CN)
Fluoride (F)
Iron (Fe)
Lead (Pb)
Manganese (Mn)
Nitrate (N)
Phenols
Selenium (Se)
Silver (Ag)
Sulfate (SOA)
Total dissolved solids
Zinc
pH**
Schedule I
1.5
0.1
2.0
0.02

0.4

500
0.10
0.4
0.4
3.0
0.6
0.10
0.6
20.0
0.002
0.02
0.10
500
1000
0.6
6.5-8.5
*New York State Groundwater Classifications
Standards (Part 703).
A A **U A..* »-l A A
Schedule II
1.0
0.05
1.0
0.01

0.2

250
0.05
0.2
0.2
1.50
0.3
0.05
0.3
10.0
0.001
0.01
0.05
250
500
0.3
6.5-8.5
and
* A£
Contaminant
Arsenic
Barium
Cadmium
Chromium (Total)
Copper

Cyanide
Fluoride
Lead
Nickel
Phenols
Selenium
Silver
Zinc
COD
Threshold Odor Number (TON)
Linear Alkylate Sulfonates
Chlorides
Sulfates
Total Dissolved Solids
Nitrate as (N03)

Heavy Metal Ratio shall not

Cu Zn . Pb Cr
20 100 50 500
Maximum Value
Allowed
50 ug/£
1,000 Mg/1
30 wg/*
500 vg/fc
20 MgM

10 ug/Jl
1,200 ug/i
50 ug/i
800 ug/l
5 ug/*
10 ug/i
50 vg/i
100 wg/i
10 ug/1
3
1.0 mg/t
250 mg/1
250 mg/l
500 mg/1
10 mg/1

exceed 1.00:

"30" + 800 " 1'°l
                           range indicated  above, the natural pH may be one
                           extreme of the allowable range.
Where the  abbreviation for the metal In the fraction
is the measured concentration in the effluent in
micrograms per liter (yg/Z.).
                                                                                         •Missouri Groundwater Recharge and Irrigation
                                                                                          Return Water  (Appendix: III).

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                    Table 3.4B

National Interim Primary Drinking Water Regulations

Maximum Contaminant Levels for  Inorganic Chemicals*
                                         Level
     Contaminant                         (mg/Jl)
     Arsenic                              0.05

     Barium                               1

     Cadmium                              0.010

     Chromium                             0.05

     Fluoride                              **

     Lead                                 0.05

     Mercury                              0.002

     Nitrate (as N)                      10.

     Selenium                             0.01

     Silver                               0.05
  Federal Register, p 59570, December 24, 1975.
**
  Fluoride is regulated as a function of average
  daily maximum air temperature:

     Air Temperature            Fluoride Level
          12.0                       2.4
       12.1-14.6                     2.2
       14.7-17.6                     2.0
       17.7-21.4                     1.8
       21.5-26.2                     1.6
       26.3-32.5                     1.4
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3.3.2.2  Surface Mining Control and Reclamation Act Promulgated
Interim Enforcement Provisions
     The "Surface Mining Control and Reclamation Act" was passed  in August
of 1977.  Resultant interim regulations have been in effect since December
1977.  The proposed permanent regulacory program was published in September
1978, with final regulations expected in 1979.
     The interim standards issued for reclamation requirements as a
result of SMCRA include protection of surface water.  It is at present
unclear how these performance standards will be applied to a  situation
where FGC waste material is disposed of in a mine.  The Office of Surface
Mining in the Department of Interior has indicated  that it will  develop
a position on this issue during 1979.  For the present, it is assumed
that requirements of  standards for reclamation would have to  be  met  if
FGC wastes were disposed of in mines.
     The interim regulatory program requires that all surface drainage be
passed through one or more sedimentation ponds.  This would produce  a
point source discharge.  The regulations require that such discharges
meet applicable state and federal laws, but at a minimum must meet  the
following effluent limitations-'-:
                                                      Average of Daily Values for
Effluent Characteristic       Maximum Allowable       30 Consecutive Discharge Day
  Iron,  total                   7.0 mg/S-                      3.5 rog/X,
  Manganese,  total              4.0 mg/£                      2.0 rag/*.
 -Total suspended solids       70.0 mg/£                      35.0 mg/fc
  pH                         within the range
                              of 6.0 to 9.0

      Treatment must  be used if limitations are not met  (although sedimen-
 tation ponds can be  a form of treatment).  For a number of the  mountain and
 western states, total suspended solids will be determined on a  case-by-case
 basis, and  the limitations for this  parameter are  somewhat more restrictive.
  Adapted from "Surface Mining, Reclamation and Enforcement Provisions,"
  Dept. of the Interior, Office of Surface Mining Reclamation and
  Enforcement, Dec. 13, 1977.
                                   3-31

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     The commentary process on these regulations indicated that EPA may
have more stringent limitations under FWPCA, which would have to be met.
In addition, the limitation for manganese in the interim program is appli-
cable only to acid drainage [51].   This change was based on the fact that
there was reported to be insufficient data to justify limitations on man-
ganese in alkaline waters.
     For underground operations, similar effluent limitations apply to discharge
from sedimentation ponds.  In addition, any discharge from areas disturbed
by underground or surface mining, must meet state and federal regulations
and  the effluent limitations established in these standards.  It is not
clear how disposal of FGC wastes in deep mines will be viewed as this issue
is not explicitly covered by the interim regulations.  For the present, it is
assumed by the authors that such disposal would be permitted provided all re
ulatory standards for water, etc. could be met.  In particular, the regulati
establish particular measures to prevent water pollution from mine drainage,
which include:
     •  Diverting water from underground workings»
     •  Preventing water contact with toxic-forming materials and
        minimizing contact time with waste  (as defined by SMCRA
        regulations), and
     •  Maintaining barriers to enhance post-mining inundation
        and sealing .

It would appear that these measures, at least the first two, would make dis-
posal of non-mining wastes more acceptable.

Proposed Permanent Regulatory Program
     The proposed regulation,  promulgated on September 18, 1978 for the perma-
nent regulatory program under the Surface Mining Control and Reclamation
Act have several important changes over the draft form of these regulations
that were circulated in July 1978.  One key difference concerns the
"discharge water into underground mines."  Under the draft regulations, the
following requirements were stipulated:
                                 3-32

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    "The regulatory authority may approve the discharge of water into
      abandoned mine voids when the water is used as an integral com-
      ponent of any operation conducted for the purpose of water dis-
      posal, fire extinguishment, or subsidence control, and provided
      that
     (1)  the hydrology of the ground or surface water approximate
         to the disposal area is not affected,
     (2)  the mine water pool remains essentially static,
     (3)  such water is treated for any and all pollutants if  it is
         discharged on the  surface, and
     (4)  introduction of water into the voids is acceptable when
         all other geologic factors have been considered.
     The  source of water shall be designated prior  to its mixture and
     injection, and any and  all affects on the hydrology and geology
     of the subjacent as well as superjacent strata shall be specified."
     This section  changed  substantially in  the  September 18th  publication.
     "Surface water shall not be diverted into  underground mine workings
      unless the person who  conducts  the surface  mining activities
      demonstrates  to  the  satisfaction  of the  regulatory authority
      that  the  diversion will—
     (a)   abate water  pollution or  otherwise eliminate  public
          hazards  resulting  from underground mining; and
     (b)   be discharged as  a controlled flow meeting the water
          quality  requirements of  Section  816.52  for pH and
          total  suspended  solids  except that  the  total  suspended
          solid  concentration  may  be exceeded  only if the sus-
          pended material  is approved by the  regulatory authority
          or is  limited  to—
         (2)  fly ash from  a coal-fired facility;
         (4)  flue gas desulfurization sludge;
     (c)  the discharge will not cause, result in,  or contribute
         to a violation of  applicable water quality standards;
     (d)  minimize disturbance to the hydrologic  balance."
(Section  816.55, Surface Mining and Reclamation Operations, proposed  rules
for permanent regulatory program.)
                                    3-33

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      This  is  one means  by  which  the Office  of  Surface Mining could control
 underground injection of materials  into  underground mines in lieu of EPA
 regulations of  similar  types  of  land disposal.

      The discussion  accompanying these proposed  rules is interesting in that
comments are made on the development of  the water quality  standards of  the
Surface Mining Control and Reclamation Act.   The  following are  quotes  from
this discussion (Federal Register, Volume 43, No. 181, pages 41744-41745) :
     "In developing these standards, an  alternative considered  by the
      drafters in response to  public comment was  to do no more  than
      incorporate by the reference EPA's  Effluent Guidelines and
      Standards  for the  Coal Mining Point Source  Category  under the
      National Pollution Discharge Elimination  System Permits Program.
      This  alternative was  analyzed  and rejected  for several reasons.

     "First,  the proposed  effluent limitations  would be  applied through-
      out the  entire  phase  of  surface coal mining and reclamation
      operations,  as  required  for the protection  for the hydrologic
      balance  .  .  . whereas EPA's effluent limitations regulations
      apply only to the  active phase of mining  operations  . . .

     "A second reason why this alternative is not being  adopted is
      that  U.S.  EPA's regulations apply only to existing point
      source discharges  of  water  from mining operations  and do  not
      apply to non-point source discharges .  .  .

     "The third  reason why  the use of EPA's  regulations  alone is
      believed to be  insufficient is that these regulations do  not
      apply at all to discharges  of  ground water."
                                  3-34

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3.3.2.3  Surface Water Quality Issues Related to Runoff:  Issues Defined
         By Existing and Emerging Regulations
RCRA
     Regulations under Section 3004, concerning standards applicable to
owners and operators of hazardous waste treatment storage and disposal
facilitites have been proposed by EPA (December 18, 1978).  Priority
issues relating to surface water contamination by runoff from hazardous
waste treatment, storage, and disposal facilities (which are addressed
by the standards) include site selection, design, monitoring, and closure
of such facilities.
     The legislation requires the integration of RCRA with existing regula-
tions to the maximum extent practicable.  Hence, it is expected that the
performance standards established by the regulations under Section 3004
will interface with the point source permitting authority NPDES established
under the Federal Water Pollution Control Act (FWPCA) (PL 92-500).
     An important consideration with respect to the regulations under
this section concerns discharges to surface waters other  than navigable
waters.  Proposed regulations under RCRA reference the NPDES  (permit)
regulations under FWPCA which are applicable only  to  point  source dis-
charges to navigable waters, which  is  not  a  restriction on  RCRA juris-
diction.  Controversy may arise  over any expansion of the NPDES permit
program beyond  the  jurisdiction  of  FWPCA.  A related  area of concern may
be  the integration  of RCRA with  existing federal  legislation emphasizing
other water quality considerations  (e.g.,  the  Safe Drinking Water Act).
      It appears likely  the facility siting  considerations will be given an
 emphasis under the regulations for Section  3004.  Such siting consider-^
 ations may be viewed primarily in terms of  land use  (I.e., location with
 respect to residences,  roads, etc.) and safety (location with respect
 to active faults).  However, there may also be consideration of  issues
 critical to surface run off in the site selection criteria.  In  par*-
 ticular, the location  and  design of facilities which may be  subject to
 "worst case" run off situations (i.e., flood conditions) may be  of  par-
 ticular concern with respect to the treatment, storage,  and disposal  of
 hazardous wastes.
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      Without proper maintenance or monitoring,  surface  runoff  and  other
 discharges from closed facilities may continue  to  affect  water quality
 long after the operations  of such facilities  have  ceased.   The proposed
 RCRA regulations address this problem within  the context  of Section  3004.
 The  Legislative requirements for continuity of  ownership  and financial
 responsibility may be utilized to require owners to  make  provision for
 monitoring and maintenance of closed  facilities, as  well  as insuring that
 such facilities are closed in a safe  manner consistent  with the public
 helath  and environmental safety.
      Specific requirements for monitoring of  surface waters, emphasizing
 waters  on  site,  are required with respect to  the determination of  contam-
 ination.   Visual inspections are also likely  to be required, to insure
 that maintenance operations are effective in  the prevention of unantici-
 pated hazards or discharges.
      The December  18,  1978,  proposed  regulations [8]  pursuant  to Section 3004
 temporarily exempt FGC wastes from hazardous  waste disposal procedure
 standards,  including  those which address  the  control of runoff and leach-
 ate.  The  regulations classify FGC wastes as  "special"  to be subject to
 further rulemaking at some point  in the future.  The regulations imply
 that  some,  but not all, FGC wastes may be subject  to the  disposal  require-
 ments for  hazardous wastes  on a case-by-case  basis if tests do warrant.
 Effluent Related Issues of  Proposed Federal Regulations
     Effluent related  issues  considered within  the context  of  RCRA may be
 viewed in  terms of the classification of  material  as having either a
 hazardous  or non-hazardous  nature.  Hazardous materials will fall  under
 the jurisdiction of Federal  regulations.   Certain  components of a  waste
 which are  considered particularly  hazardous may  receive special attention
 in regulations.  Such  components include boron,  molybdenum, selenium,
which are often present inf FGC waste, but which are likely to  be  pro-
hibited for disposal via landfarming when present  in waste material.
Other components which could  receive  special attention  in the  regulation
with reference to  landfill as a disposal option  include cyanide, arsenic
chromium, and other heavy metals.
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     Effluent from the treatment or processing of wastes,  particularly
hazardous wastes, could be classified as constituting a hazard to health
and the environment, and therefore, controlled under the regulatory pro-
visions for the various disposal options under Section 3004 (subject, of
course, to the criteria established for the determination of hazardous
waste under Section 3001).
State Programs Under RCRA
     Subtitle D of RCRA is entitled "State or Regional Solid Waste Plans."
Among the objectives of the subtitle are to provide for federal guidelines
for state solid waste disposal plans;  establish procedures for develop-
ment and implementation for such plans; and provide for federal assistance
to the states for activities such as facilities studies, technology
assessments, legal expenses, etc., in connection with  the planning effort
and the implementation of programs.
     The criteria for determining which solid waste disposal  facilities
pose no reasonable probability of adverse effects on health or  the envir-
onment (Federal  Register, February 6, 1978) through degradation of surface
waters include the compliance of point  source discharges  (including
collected surface runoff) with the National Pollutant  Discharge Elimina-
tion System  (NPDES) permits issued under  Section  402 of  the FWPCA amend-
ments.  Additional  criteria include  the control  of  non-point  source  dis-
charges  (including  surface runoff) to prevent or  minimize  such  discharges
into any off-site surface water.
     The objectives of  the RCRA "non-hazardous"  waste  landfill  surface
water  criteria are  to assist  in  attaining the objectives  of the FWPCA.
The permit  requirements  under Section  402 of  that Act  provide the method
for  the  regulation  of point  source discharges which may have  adverse
affects  on  surface  waters.   The criteria  provide for additional controls
on non-point source discharges,  to the extent that such discharges be
 "prevented  or minimized."  To comply with these requirements, non-point
 source discharges can be collected,  by channeling into a ditch or trench,
 and  regulated as point-source discharges.  Collection of non-point sources
 (i.e., surface leachate, leachate seepage, and including surface runoff)
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creates a point source, which is required to comply with the NPDES permit
if discharged to off-site surface waters.  These criteria under RCRA
thus deal with both point and non-point source discharges from solid
waste disposal facilities by deferring to the FWPCA with respect to the
former; and by establishing criteria for the states to use in regulating
the latter, which, in effect, require that the discharges, including
surface runoff, be considered as a point source.  Thus, most discharges
from solid waste disposal facilities can be subject to the requirements
of the NPDES permit.
     In total, the proposed criteria are interpreted to comply with the
requirements of Section 1008 (a) (3), which authorize guidelines "	
to provide minimum criteria to be used by the states to define those
solid waste management practices which constitute the open dumping of
solid waste or hazardous waste	"  The criteria in addition suggest
guidelines under Section 1008 (a) (2c~), providing for the "	protection
of surface waters from runoff through compliance with effluent limitations
under the FWPCA, as amended	"
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3.4  State Requirements and Plans
3.A.I  Present Status
     The states are at various stages in regulating and planning for the
management and disposal of solid wastes.  Presented are brief descriptions
of the legislative and regulatory requirements of selected states which
have been suggested by EPA staff at regional and national levels to be
relatively advanced on the issues of solid waste management and disposal.
Table 3.5 lists the states whose solid waste regulations are discussed
in the subsequent pages of this report.
Region I:  Maine
     Solid waste management regulations were promulgated under Title 38,
Maine revised statutes, Section 1304, and became effective in February
1976.  Chapter IV of the regulations addresses land disposal options.
Section 406.1 specifies that a solid waste disposal site boundary shall
not lie closer than 300 feet to a classified body of water, nor closer
than 1,000 feet to a potable water supuly.  The Department of Environmental
Protection deems these buffer zones to be sufficient to protect surface
water.  Other requirements to protect surface water include moderate
slope  (i.e.. less than 15%) and "good design and operation."  Sites not
meeting the site characteristics criteria may be approved  if  "... good
design and operation can be shown  to provide adequate  protection  to
surface  ... water resources."
     One  element of design which the Department will review  is  the
diversion of surface waters away from  the proposed  disposal  site.
Drainage  systems will  also be reviewed  before any  plan is  approved.
     The  determination of whether  or not  a  waste is hazardous will  be
made by  the Department on  request.   The state apparently  does not have
a hazardous waste management  program at present.   The  requirements  of
RCRA are  expected  to  be  incorporated into  the solid waste management
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                    Table 3.5
Management and Disposal of Solid Wastes in States
                              State  Whose
                              Regulations
Federal Region                are Discussed
    I                          Maine
    II                         New Jersey
    III                        Pennsylvania
    IV                         Tennessee
    V                          Illinois
    VI                         Texas
    VII                        Kansas
    VIII                       California
    IX                         Oregon
 The states listed were chosen for illustrative
 purposes.  All 150 States are at various stages
 of planning or implementing management of solid
 waste disposal operations.
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plan now being drafted; and are expected to substantiate and reinforce
the states existing regulations.   Hazardous wastes in the state are
likely to be more stringently controlled in the state as RCRA
Subtitle C regulations are promulgated an^ become effective.

Region  II:  New Jersey,
     The New Jersey Solid Waste Management Act was passed in 1970; important
amendments to the Act were passed subsequently,  including Chapter  326,
passed  in 1975.  The Act and its amendments address solid waste manage-
ment planning in the state and issues concerning collection and dis-
posal of solid waste.

     For planning purposes, each of the 21 counties in  the  state and  the
Hackensack Meadowlands District was designated" a solid  waste management
district.  Two  groups  of  districts are  required  to have plans  completed
by early  1979;  the  third  group of districts must complete plans by mid
1979.   Plans  are required to  cover a  ten  year period  and are to be
updated every two years.

     With respect to hazardous wastes,  the legislation  requires monitoring
wells to be installed at any site accepting hazardous or chemical
wastes, bulk liquids or  pesticides.   Discontinued acceptance of the
waste and implementation of "an acceptable system of interception,
 collection,  and treatment" is required if analyses indicate a hazard
 or potential threat to water quality.  The legislation also requires
 interception, collection, and treatment of all  leachate generated at
 a solid waste facility.   The effective date of  the regulation is  set
 at 1980.

      The regulations prohibit any new sanitary  landfill to be constructed where
 solid waste is or would be in contact with surface or  groundwaters. A
 similar provision applies to existing landfills.  The  impairment  or
 further degradation of surface or groundwaters  as a result of solid
 waste disposal activity or leachlate generation is prohibited.  Ground
 water  monitoring is required of new  facilities.
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     The only specific mention of by-products resulting from air pollution
control devices was in the context of  the disposal of incinerator
residues.

     The New Jersey definition of hazardous waste is broad and bears
similarity to the legislative definition in RCRA.  There is citation
of the definitions of toxicity determined under the Occupational Safety
and Health Act, and hazardous materials classification of the Department  of
Transportation.  RCRA., however,  post-dated  the  legislation and  is  not  cited.

     The New Jersey legislation  is considered to have anticipated  the  require-
ments of RCRA in some respects,  including the designation of planning
districts and the development of solid waste management plans.  New
Jersey also requires a manifest  system for tracking of hazardous
wastes.  Reduced incidence of ocean  dumping is  expected  to result  in
increased emphasis on land-based disposal in  this densely populated
state.

Region III;  Pennsylvania
     The Commonwealth is in the  process of revising the state solid waste
management plan.  The Solid Waste Management Act was passed in 1968
as Act 241.   Regulations under the Act are found in Chapter 75 (Solid
Waste Management Rules and Regulations).

     The planning process is addressed in Subchapter B of Chapter  75.  Solid
waste management planning in the Commonwealth is initiated at the level
of the municipalities.   Subchapter C addresses permit and standards
for disposal facilities.   The design criteria for sanitary landfills
address the issue of surface water contamination through set-back
requirements (25 feet) and requirement for the management of surface
water.  In addition, "the site shall be designed and operated in a
manner which will prevent surface water percolation into the solid
waste material deposits." Section 75.37(e) addresses surface water
management techniques for the standards for fly ash f bottom ash  or
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slag disposal areas.  The provision may be appropriate to FGG wastes
as  they may include fly ash.  Surface runoff from "adjacent areas should
be  diverted avay from flyash on slag disposal piles (s)...(and)
run-off shall not be allowed to discharge freely onto the slopes of
the fill."  In addition to these requirements for control of runofT,
it may be necessary to provide "contingency plans for treatment of
run-off from the fill..."

     Section  75.38  addresses  general  standards  for  industrial  and
hazardous waste disposal sites.  The definition of hazardous waste
in the context of these regulations is similar to that set forth
in RCRA.  To date,  the Department of Environmental Resources has
reportedly not had adverse reactions to its enforcement of the regula-
tion with respect to hazardous waste.  Specific reference to possible
surface water contamination by  runoff  with the context of the design
and operating requirements of this section are limited.

     Region IV:  Tennessee
     This  state only recently passed  solid waste management  legislation,  but
is reported by EPA staff to be further along than other states in the region.
The legislation incorporates elements similar to those specified in RCRA,
including a manifest system for hazardous wastes and an inventory of
open dumps.  Regulations under the law may be delayed until critical
issues are resolved at the federal level, including the determination
of what constitutes a hazardous waste.  As the regulatory process
proceeds, problems with respect to on-site disposal options and regula-
tion of hazardous wastes are considered possible.  Hazardous waste
criteria and a listing of hazardous wastes are required by the
legislation.

     The criteria under consideration for determining whether a waste is
  hazardous are very similar  to the criteria under  consideration by
  EPA,  as  authorized by  Section 3001  of RCRA.   It is expected that the
  Tennessee regulations  will  closely  parallel  the federal regulations
  under that  section for most classifications  (e.g., reactivity,
  toxicity).
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      Detailed studies of disposal site hydrologic characteristics may be
 required under the state regulations,  prior to the approval of  a
 disposal site.  Issues to be examined  with respect to surface water
 in location and design studies include:  site location and drainage
 relationships with contiguous areas; proximity to surface streams
 and potential for flooding;  and seasonal variation in water quality,
 evaluated for a number of parameters.   Site specific criteria under
 consideration for the evaluation of disposal sites address issues
 related to surface runoff.  Surface runoff from contiguous areas
 is expected to be controlled and not allowed to enter a
 disposal or a landfarm site.  Moreover, location and design of  a
 site is unlikely to be approved if the possibility of degradation
 of surface waters attributable to the  site exists.  Special precautions
 are likely to be instituted  to prevent exposure of a site to flood
 waters.  Federal regulations under RCRA Section 3004 may also be
 utilized in the evaluation of disposal and landfann sites.  The
 performance standards under  that section may also be applied by the
 State of Tennessee to hazardous waste  storage,  treatment, and
 disposal facilities.   Other  criteria and standards may also be  -used
 if demonstrated to be equivalent to the federal standards.

  Region V;  Illinois
      The  Illinois  Environmental Protection Act  (Illinois  revised statutes,
Chapter  111 1/2,   1001-1051) establishes  the authority of the  Illinois
Pollution Control  Board  (the Board)  to  adopt regulations  which  are, in
effect,  consistent with  the purposes of the RCRA  (e.g., the  prohibition
against and/or regulatory  control of open  dumping).  Under Title  V,
Sections 21 and 22, the Board  as authority  to set  design  and performance
standards for  "refuse collection ard disposal sites  and facilities," where
refuse  is broadly  defined  to includr garbage and other discarded  materials.
In addition, the Board has autnority to  set standards  for handling, storing,
processing, transporting and disposal of hazardous refuse.   Hazardous
refuse, in the context of  the Illinois  legislation,  is defined  as  "refuse
with inherent properties whicl.  make such refuse difficult  or  dangerous  to
manage by normal means,  including chemicals, explosives,  pathological wastes

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and wastes likely to cause fire."  Significantly, the definition of hazardous
waste in this section of the Illinois legislation emphasizes primarily the
inherent difficulty in management as the fundamental criterion for the
determination of hazard, rather than the danger posed to the health of
those exposed to the waste.

     Title III, Sections 11 and 12 of the Illinois Environmental Protection Act
address issues of water pollution in the state.  Section 12(a) prohibits
"the discharge of any contaminants into the environment in any state so as
to cause or tend to cause water pollution in Illinois"; while Section 12(d)
proscribes the "deposit (of) any contaminants upon the land in such manner
so as to create a water pollution hazard...."  Taken together, these para-
graphs may be interpreted to prohibit the disposal of any "contaminants"
on the land if such disposal endangers surface or ground waters, and nay
also be interpreted to prohibit unregulated surface runoff from a waste
disposal site, if such runoff could result in the contamination of surface
or ground waters.

     In fact, the Illinois Pollution Control Board regulations  state  "no  person
shall cause or allow the development or  operation of  a  sanitary landfill  unless
the applicant proves to  the satisfaction of  the  agency  that  no  danger  or  hazard
will result to the waters of the  state because of the  development  and  operation
of  the sanitary  landfill."  While the  rule does  not specifically address  the
issue of  surface runoff  from a landfill  site, runoff  which dees constitute
 a hazard to surface or ground  waters could be interpreted to violate the
 intent of the rule.   Rule 313  prohibits the discharge of contaminants into
 the environment so as to cause, or tend to cause, water pollution, placing
 regulatory authority behind the legislative intent of Title III, Section 12(a)
 (see above).

     Hazardous  or  liquid wastes and sludges  may  be  accepted at a sanitary landfill,
  if authorized by permit, under rule  310, which  regulates  disposal of
  Chapter  7, Part III,  "special wastes."  Thus, the  possibility of  FGC wastes
  being disposed  of at  sanitary landfill  sites  in Illinois  exists,  with such
  disposal being  regulated within the  context of  Chapter 7.
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     Regulations addressing the transportation of special wastes  are expected to
be proposed by the Board.   The primary focus of the regulations  is  anticipated
to be on the issuance of permits to special waste haulers;  to  provide pro-
cedures for the inspection of numbering of vehicles,  tanks  and drums;  and  to
require the legal hauling of special wastes to approved disposal,  storage,
and treatment sites.  It is significant that pollution control residuals
may be considered a sub-classification of special wastes but any person
hauling only coal combustion fly ash may be exempted from the  permit require-
ments of the regulations.   The wording of this possible exemption may be
critical, since admixtures of FGC sludge with fly ash may not  meet the
criteria for the permit exemption.

     It is  of interest to  note that the maintenance and submittal of operatine
 records  required  by Rule  317  apparently include  the  submittal, four times per
 year,  of water  monitoring data  (e.g.,  comprehensive  analysis  of water  samples
 from on  site  and  nearby wells and  surface waters).   Thus,  the Board is  able
 to monitor whether  water  quality standards  have  been violated by operation
 of landfill.  It  is  also  of  interest  to note  that  a  hazardous waste  disposal
 site  in  the state was  ordered closed  by a circuit  court  judge in 1978,  due
 to possible ground  water  contamination.  The  order  to  close,  which  also
 required removal  of wastes and  contaminated soil, was  termed  "landmark"
 by the state's  Attorney General's  Office.

 Region VI:  Texas
       Solid waste regulations for  the state of Texas were promulgated under th
 Texas  Solid Waste Disposal Act  of  1969,  as  amended.  The Texas Departments
 of Health and Water Resources are  jointly responsible  for  implementation
 and  enforcement of  regulations  authorized by  the act.  The  Office of Solid
 Waste Management  of the Department  of Health  is  primarily  responsible  for
 the  management  of municipal  solid wastes; industrial solid  wastes fall  within
 the  jurisdiction  of the Department  of Water Resources.   The protection  of
 surface waters  are  among  the  criteria considered in  site selection  and
 facility design.  In particular, the  criteria stipulate  the control  of
 surface drainage on a  land disposal site to "minimize  surface water  runoff
 onto, within, and off  the working  area."  This control is  to  be affected
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by "dikes, embankments,  drainage structures and diversion channels of adequate
size and grade...to control surface water."  Special requirements are also
in effect with respect to protection of a site from 50- and 100-year frequency
floods.

      Operational requirements for most conventinal  landfill sites  include  the
following:
    "1.   Solid waste shall not be placed in unconfined waters which
         are subject to free movement on the surface....
     2.   The site shall be protected from flooding by any nearby streams
         with suitable levels....
     3.   Suitable water diversion methods shall be provided to divert
         the flow of uncontaminated runoff or other surface water away
         from the active disposal area.
     4.   Rainfall runoff within the landfill area that has been contaminated
         by solid waste on other polluted waters  shall not be discharged
         from the site unless the site operation...is authorized by  the
         Texas Water Quality Board."

      There is  a provision in the regulations for the disposal of other sludges
"only if special provisions  are made and approved by  the Department."  No
definitions or examples of "other  sludges"  are  provided, and  it  is  unclear
what  the  term "other  sludges" may  include.   Department  approval  is  also
required  for disposal of  hazardous waste.
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 Region VII:  Kansas
      The Kansas  Solid  Waste  Management Act  addresses  first the organization and
 planning of  solid waste management  in the state.  The act also focuses on
 permit requirements  for the  construction, alteration  or operation of a
 solid or hazardous waste  processing facility on disposal areas.  The conditions
 of the permit  are authorized to  be  designed so as to  "protect human health and
 the environment  and  to conserve  (the disposal or processing) site."  The
 Secretary of the Department  of Health and Environment has statutory authority
 to approve the types and  quantities  of solid waste allowable for processing
 or disposal  at a permitted authority.

     "Dumping or  disposal  of  any  solid or hazardous waste onto the surface of the
 ground,  or into  the waters of the state" is deemed unlawful without having
 obtained a permit.  A  condition  for  issuance of a permit includes departmental
 approval for the installation and operation of environmental quality monitoring
 systems, including monitoring wells.

      The standards for disposal  sites addressed in the revisions of the regula-
 tions are expected to  require that  "surface runoff and leachate seeps
 shall be controlled so as to minimize non-point source discharges into surface
 waters."  Specifications  for such control are not detailed in the revisions
 to the regulations.

      Hazardous wastes  are defined in Section 64-3402  (Kansas Solid Waste Managment
 Act)  as  solid  wastes which,  because of quantity, concentration, or physical,
 chemical or  infectious characteristics, pose a hazard to the environment or
 are dangerous  to human health if improperly managed.  As in the Illinois
 statutes,  the  technique of management, in addition to inherent characteristics
 of the waste,  is considered t   contribute  to a substantial present or
 potential  hazard.  Significantly, the revisions to the standards for manage-
 ment  of  solid  waste are application LJ (a)  waste which consists of or contain
 hazardous  wastes; and  (b) any mixture formed by combining any waste or substance
 with  a hazardous waste (emphasis added).  The regulations might thus be
 interpreted as applicable to  FGC wastes,  which include trace metal species
which may be viewed as hazardous.  The burden of proof as to whether
a waste  containing components with hazardous properties listed by
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the Department,  but the criteria are still being developed.

     Industrial  wastes, i.e.,  those wastes not suitable for  discharge to a
sanitary sewer and treatment plant, may not be disposed of without a
disposal authorization by the department.

     Location, design and operation guidelines will be developed by the department.
The standards for hazardous waste disposal area (facility closure) require
the covering of cells with an impervious layer to minimize leachate and
contaminated runoff.   Maintenance of land disposal areas after closure will
include treatment of contaminated runoff.

     The Kansas  regulations incorporate many of the requirements of RCRA, including
the local solid waste management plans; manifests, and reporting requirements;
and standards applicable to generators, treatment and disposal facility
operators and transporters.  The regulations discussed here will be implemented
on a temporary basis pending legislative review in 1979.
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 Region VIII:   California
      The  California  Solid  Waste  Managment  and  Resource  Recovery Act of  1972
 and  the Hazardous Waste Control  Act are the two fundamental statutes
 relevant  to the disposal of solid and hazardous wastes  in the state.  The
 Solid  Waste Management Board  (Board) and Department of  Public Health
 (Department) are the two state agencies with primary responsibility for,
 respectively,  solid and hazardous wastes.

      The  Board has authority  in  the legislation to formulate and adopt  minimum
 standards  for  solid waste  management to protect air, water and land from
 pollution.  Standards addressed  include the location, design, operation,
 maintenance and ultimate reuse of solid waste processing and disposal
 facilities.  The Board must also review compliance of local solid waste
 management plants with state policy (plans are to be reviewed every three
 years).

      The  Board also retains permitting authority for the operation of solid
 waste  facilities.  The operation of such facilities without a permit is
 prohibited.

      The  conditions of the permit are not specified in  the legislation.
 Determination  of whether FGC wastes would be permitted  for disposal at a
 solid waste disposal site has not been made by the Board, and would depend
 on an analysis of the physical and chemical characteristics of the waste.
 A finding that the waste is hazardous would place its disposal within the
 jurisdiction of the Department of Public Health.   The Department is authorized
 by legislation to make a listing of hazardous wastes, and regulation criteria
 and guidelines for the identification of hazardous and extremely hazardous
wastes.  The Department also sets minimum standards for operating pro-
 cedures, including handling, processing, use,  storage and disposal of hazardous
wastes.  In addition, the Department sets standards for the use and operation
of hazardous waste facilities.

      The  legislation is specifically concerned with the protection of public
 health and safety and that of domestic and wild life.   To this extent,  though
 not  explicitly, the legislation  addresses the degradation of surface water
 quality by runoff.
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 Region IX;   Oregon
     Solid waste regulations for the State of Oregon were authorised under
Chapter 459 and subsequent amendments.   Hazardous wastes are specifically
addressed in Section 459.410-690 of the statute.   The regulations contained
in the Oregon administrative rules pertaining to  solid waste management
are likely to be revised and expanded during 1978.  The new rules, however,
have not been proposed by the Department of Environmental Quality (DEQ) at
the time of this writing.  Hence, the discussion  will focus on the old rules
presently in force.   In addition, current rules pertaining to the management
of environmentally hazardous wastes are expected  to be completely revised
during early 1979.  It should be recognized that  the regulatory requirements
in the State of Oregon with respect to the management of solid and environ-
mentally hazardous wastes may be significantly altered before 1980.  How
the revised regulations will be influenced by the developing regulatory
framework authorized at the federal level under RCRA is yet undetermined.
In certain respects, Oregon is considered to have progressed quite far in
the management of environmentally hazardous waste.  The state reportedly
has the only licensed and regulated hazardous waste disposal site in operation
west of the rockies.  Environmentally hazardous waste disposal sites are
licensed and regulated under Chapter 340, Section 6, Subdivisions 2 and 3
of the Ohio administrative rules.  Subdivision 2  specifies  the procedures  for
issuance, denial, modification and revocation of  licenses  for the disposal
of environmentally hazardous wastes.  Subdivision 3 establishes  "requirements
for environmentally hazardous waste management from the point of waste
generation to  the point of ultimate disposition..." and addresses the classi-
 fication and declassification of  environmental hazardous wastes.  The general
requirements of  the subdivision  bear similarity  to certain requirements of
RCRA,  such as  the maintenance and reporting  of records.  Waste classified
 as environmentally hazardous include pesticide and radioactive wastes  (no
 disposal sites for radioactive wastes can be established,  operated, or  licensed
 in the state).   The statutes make specific provision  for the establishment
 of a  chemical  waste disposal site in  the state,  and  provide for  its  regulation
 by DEQ (see  above).
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 3.4.2   State  Responses  to  December  18,  1978,  Proposed Regulations
        Under  RCRA
     In December,  1978,  EPA published proposed  regulations under Subtitle
 C  of the Resource Conservation  and  Recovery Act (RCRA).  The specific
 proposals concerned:  "(1)  the  criteria for identifying and listing
 hazardous wastes,  identification methods and  a  hazardous waste list;
 (2) standards applicable to generators  of such  waste for record keeping,
 labeling,  containerizing and using  a transport  manifest; and (3) performance
 standards for hazardous  waste management facilities."  The proposed criteria
 and standards are likely to effect  pre-existing state-level hazardous
 waste management  regulations and programs, and  to influence the form of"
 such regulations  and programs in those  states which have not yet enacted
 hazardous waste legislation comparable  to RCRA.
 Tennessee
     State hazardous waste  regulations  are still in draft form,
 incorporating  changes based  on  recent public hearings.  Latest draft is dated
 November,  1978.  After consideration of  all public comments, further
 changes may be made before  regulations  are finalized.
     The  November draft  is   reported to  be similar to EPA's proposed
 regulations for hazardous waste.  With  respect  to fly ash  bottom ash, and
 other air  pollution control wastes, the  likelihood is that these wastes
 will be considered as special cases.  Such wastes are deemed to be of
 relatively low hazard, but will be  generated in sufficiently high volume
 to merit  special consideration.  The state is trying to recognize these
 kinds of wastes.  "Utility wastes"  are not defined in the Tennessee list
 of hazardous wastes, as  they are in the  proposed federal regulations
 pursuant  to RCRA.   However, fly ash, bottom ash, and scrubber sludges are
 specifically identified  as POL aitially hazardous.
     The state intends to pursue federal  funding although the test will
be whether the regulations as promulgated will be sufficiently stringent
 to qualify.
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Pennsylvania
     The State Department of Environmental Resources,  Office of Solid
Wastes (OSW) anticipates that some changes will be forthcoming in the
Pennsylvania solid waste management regulations as a result of EPA's
proposed Subtitle C regulations.   However, the changes in the Pennsylvania
regulations are as yet undeveloped, and it is too early to say what form
those changes may take.
     The Pennsylvania solid waste program is not yet completely approved
for acceptance as a state solid waste management program.  The OSW will
most likely pursue federal approval and funding.  The recommendations of
the OSW in this matter have apparently not yet been acted on by the
Secretary of the Department or the Governor.  The response to the Subtitle
C proposed regulations may have some bearing on the decision to pursue,
and timing for obtaining federal approval.
     Utility wastes are now categorized as a solid  (not hazardous) waste,
and are disposed at approved sites.  Perhaps because of the existence of
apparently effective regulations and disposal sites, wastes generated by
coal-fired electric utilities are not now considered to be a problem in
the state.
Florida.
     Existing environmental legislation in the  state has  designated an
Office of Hazardous Waste  (OHW) under the Department of Environmental
Regulation.  The present hazardous waste  program  is based on  the case-by-
case determination of  the hazardous nature of waste material.   If a waste
is  found to be hazardous,  the legislation requires  that the waste be
rendered innocuous and/or  disposed of in  a manner approved by  the
Department.
     The OHW  and Department are proposing comprehensive hazardous waste
legislation in  the next legislative  session.   Similar  legislation was
proposed by the Department in  the previous  session,  but was  not acted  on
by the  legislature.   To date,  the proposed  legislation has  no sponsor,
and it  appears  premature to  estimate chances for, or timing of, enactment.
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      In  its present  form, OHW staff perceive  the proposed legislation to
be comparable  to RCRA definitions of, and criteria for, hazardous wastes.
It appears to  be the intent of  the Department to be independent, in the
sense of formulating legislation and regulations which address problems
peculiar to Florida.  However,  it appears likely, if the proposed program
is adopted, that the state will attempt to respond to federal guidelines
for hazardous  waste  under the solid waste management progam and hence
pursue federal funding.
     It also appears likely that the state will adopt a position similar
to EPA, in the matter of special case wastes, e.g., utility (and in
Florida, gypsum) wastes.  In its proposed form, the Florida Act is broad
enough to provide for interim,  or special case, status for such wastes.
North Dakota
     The basic plan  of the state at this time is to assume administrative
responsibility of the Federal Hazardous Waste Program in North Dakota.
Enabling legislation has been passed, but the state presently has no
program.  The  legislation is vague, and there is no provision for civil
penalties.   Utility wastes are now handled on a case-by-case basis.
There are five or six major power plants in the state; hence, utility
wastes are and will be a malor concern.  The solid waste office is work-
ing with the state geological survey in studying disposal options and
also formulating responses to the federal proposal.  The state solid
waste office does not anticipate a significant problem from the disposal
of fly ash and bottom ash, but does anticipate a potential problem in the
disposal of scrubber sludges.
     Site specific criteria are and will be an important factor in
authorized disposal of these wastes.
     North Dakota will pursue federal funding of its program, if in fact
the federal program is adopted.   Adoption and implementation could take
one to two  years, depending oh when the federal program is finalized.
Illinois
     The proposed EPA regulations were considered by the Division of Land
and Noise (the state agency with solid waste management responsibility)
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to be more stringent than existing Illinois regulations.  A specific
example of this federal stringency was noted with respect to the
heavy metals.  Thus, for the hazardous waste criteria, there is a like-
lihood that the state will incorporate elements of the federal program.
Changes may also be forthcoming with respect to state standards for
hazardous waste generators and management facilities.
     The position of the state regarding control of special wastes, (i.e.,
utility wastes) is apparently still unclear because of a question of
whether such wastes are, in fact, hazardous.  Illinois regulations are
now compatible with certain requirements of the special waste standards
(i.e., the manifest system).  Enabling legislation under which other
requirements could be met is on the books.
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 3.5  Ocean Disposal Related
 3.5.1  Statutory Base
     The Marine Protection Research and Sanctuaries Act of 1972 (PL92-532)
 is the basis for all domestic regulation of ocean dumping from vessels.
 Several major provisions of this legislation are discussed below.  Dis-
 posal in the ocean via outfalls is regulated as a point source under the
 NPDES permit program under the FWPCA.
 Policy
     Section 2(b) of the Act states,
     "The Congress declares that it is the policy of the United States
     to regulate the dumping of all types of materials into ocean
     waters and to prevent or strictly limit the dumping into ocean
     waters of any material that would adversely affect human health,
     welfare, or amenities, or the marine environment, ecological
     systems, or economic potentialities."
Mandatory Considerations in the Issuance of Permits
     The Act states that no dumping may take place without a permit from
the Administrator of the EPA.   Section 102(a) conditions the issuance of
such permits upon determination by the Administrator that, "...such
dumping will not unreasonably degrade or endanger human health, welfare,
or amenities, or the marine environment, ecological systems, or economic
potentialities."  The specific review criteria to be used in reaching
these determinations are prescribed as follows:
     "(A)  The need for the proposed dumping.
      (B)  The effect of such Jumping on human health and welfare,
          including economic,  aesthetic, and recreational values.
      (C)  The effect of such dumping on fisheries resources, plankton,
          fish,  shellfish, wildlife,  shore lines and beaches.
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      (D) The effect of such dumping on marine ecosystems, particularly
         with respect to -
         (i)   the transfer, concentration, and dispersion of such
               material and its byproducts through biological,
               physical and chemical processes,
         (ii)  potential changes in marine ecosystem diversity,
               productivity, and stability, and
         (iii) species and community population dynamics.
      (E) The persistence and permanence of the effects of the dumping.
      (F) The effect of dumping particular volumes and concentrations
         of such materials.
      (G) Appropriate  locations and methods of  disposal or recycling,
         including  land-based alternatives and the  probable  impact  of
         requiring  use of  such alternative locations  or  methods upon
         considerations  affecting  the  public  interest.
      (H) The  effect on alternate uses  of  oceans,  such as scientific
         study,  fishing,  and  other  living resource  exploitation, and
         nonliving  resource  exploitation.
      (I) In designating  recommended sites,  the Administrator shall
         utilize wherever feasible locations  beyond the  edge of the
         Continental  Shelf."
Penalties
     Section 105 of  the Act provides for civil penalties  of  up to $50,000
for each violation of  the Act.  It  further provides for criminal penalties
of not more than one year imprisonment, $50,000 fine,  or  both.  Both the
government  and private citizens are provided the opportunity to obtain
injunctive relief by Section 105 of the Act.
Preemption of Other Jurisdictions
      Section 106(d) of the Act precludes state, interstate, or  regional
authorities from adopting or enforcing any rules or regulations relating
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 to ocean dumping.   States may propose ocean dumping criteria to  the  EPA
 Administrator who  may adopt them if he wishes.   Thus,  unlike the regula-
 tory climate surrounding land disposal alternatives,  ocean  disposal  of
 FGC wastes by vessels is the direct responsibility of  only  one agency,
 the Federal EPA.
 Establishment of Regulations
      Section 108 of the  Act gives the Administrator the  authority to
 establish such regulations as he deems appropriate.  The existing and
 possible future regulations are  discussed  below.
 3.5.2  Administrative Regulations
      Ocean dumping regulations were first  promulgated  by the EPA in
 October 1973 to become 40 CFR 220-227.   Subsequent amendments were adopted
 during  1974 and 1977.  Two sections of  the ocean dumping regulations are
 particularly relevant  to the subject of this report.   These are  sections  227
 and  228  which,  respectively,  cover  the  criteria  for the  evaluation of permit
 applications for ocean dumping and  the  need for ocean  dumping (227)  and
 the  criteria for the management  of  disposal sites  for  ocean dumping  (220).
 Part 228 was added  to  the regulations  in 1977, and major changes to
 Part 227 took place during this  same time  frame.   Changes in the following
 aspects of  the  regulations are discussed below:
      •  Alternatives;
      •  Prohibited materials;
      •  Other factors  limiting permissible  concentrations;
      •  Monitoring requirements;
      •  Outfalls; and
      •  Artificial reefs.
 3.5.3  Consideration of Alternatives
     As of  the  1977 amendments of the regulations,  ocean dumping permit
applicants must demonstrate that there is no feasible alternative  to
dumping.  The following factors are included in determinations of  the
need for ocean dumping versus available options:
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need for ocean dumping versus available options:
     •  degree of available treatment of the waste;
     •  available raw material and process changes;
     •  relative environmental impact and cost of ocean dumping and
        other alternatives, including but not limited to landfill, well
        injection, recycling, additional treatment,  and storage; and
     •  irreversible or irretrievable consequences of the use of
        alternatives to ocean disposal.
Determinations of the cost feasibility of available alternatives to ocean
disposal do not require that costs be competitive and  take  into account
environmental benefits as well.
3.5.4  Prohibited Materials
     Under regulations in existence prior to 1977, eastern FGC wastes
could have been precluded from ocean disposal entirely on the basis of
the cadmium content of the solid phase of many of the materials containing
fly ash.  This is because absolute limits existed on cadmium and mercury
concentrations in both the solid and liquid phases of all materials.  These
limits were,  for mercury, 1.5 ppm in the  liquid  phase of the waste and
0.75 ppm in the  solid phase; and for cadmium, 3.0 ppm in the liquid
phase and 0.6 ppm in  the solid phase.
     Mercury  and cadmium are no longer  listed as prohibited materials  in
the new regulations.  This is perhaps  the single most  important change  in
the regulations  with  respect to FGC  wastes.   These substances  are  now
listed as constituents prohibited as other  than  "trace  contaminants",
with a new  set  of interim  and anticipated ultimate means of determining
whether the "trace  contaminant" definition applies.  The current  criterion
for mercury in  the  liquid  phase of  the wastes to be  dumped  in  the ocean
is as  follows:
      "...mercury concentrations in  the disposal  site,  after allowance
      for  initial mixing, may exceed the average  normal ambient concen-
      trations of mercury  in  ocean waters at or near  the dumping site
      which would be present  in the  absence of dumping, by not more than
      50%..."

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     A complementary criterion to be applied to all wastes, including
FGC wastes, is a series of bioassay tests.  The object of these tests is
the identification of both acute and chronic toxicological impact poten-
tials of the waste and the potential for bioaccumulation of toxicants in
marine organisms as the result of exposure to the waste.  The regulations
indicate that bioassay procedures for suspended particulate and solid
phases of waste materials are not sufficiently well developed to mandate
the use of such tests as a prerequisite for permit approval.  Thus, in
the interim, while such procedures are being developed, the EPA personnel
responsible for the administration of ocean disposal programs (usually at
the regional level) are given a number of options for application review.
With respect to mercury and cadmium in the suspended particulate and
solid phases of wastes, the interim guidance is as follows.
     Mercury and its compounds may be present in the solid phase of a
material in concentrations less than 0.75 mg/kg or less than 50% greater
than the average total mercury content in natural sediments of similar
characteristics at the disposal site.  Cadmium and its compounds in solid
phase may be present in concentrations less than 0.6 mg/kg or, as with
mercury, less than 50% greater than the total cadmium content of the
natural sediments of similar characteristics at the disposal site.  While
these numerical limits are identical to those in the previous regulation,
the wide range in "natural" sediment concentrations of mercury and cadmium
at disposal sites would ensure considerably greater flexibility than the
previous regulations.
3.5.5  Other Factors Limiting Permissible Concentrations
     The 1977 amendments to the regulation changed the "mixing zone"
concept of previous regulatu is defining a "release zone" as a cylinder
whose outline is 100 meters from the perimeter of the conveyance engaged
in dumping.
     In the mixing zone, no parameter may exceed .01 of a concentration
shown to be toxic to appropriate sensitive marine organisms over a 4-hour
period.   Field data, mathematical modeling, or theoretical turbulent diffu-
sion relationships may be employed to determine the limits of the area of
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said toxicity.   When no other means are feasible,  it may be assumed for
purposes of calculation that the waste is evenly distributed through the
release zone over the upper 20 meters.  These amendments all provide
greater flexibility in the permit process.
3.5.6  Monitoring Requirements
     The new regulations contain a section 228 devoted to disposal site
management, including monitoring requirements and requirements for the
evaluation of the environmental impacts of disposal activity.  A major
change in agency philosophy is reflected in these requirements.  Pre-
viously, it appeared that permit applicants might be responsible for
baseline and trend assessment monitoring at disposal sites.  However,
Part 228 clearly spells out that these responsibilities belong to the
federal government.  Applicants' responsibilities are now confined to
special monitoring programs designed case by case to determine short-term
impacts of disposal activities.
     Another important part of the regulation is the establishment of
criteria for the evaluation of disposal  impacts.  In summary,  these
criteria establish a category of impacts  (Category  I) which,  if identi-
fied at a disposal site, requires  the EPA management authority to place
limitations on use of  the  site to  reduce  impacts to acceptable levels.
These Category I impacts include:
     •  statistically  significant  decrease in populations  of  valuable
        commercial or  recreational species or species essential to  the
        propagation  of valuable  commercial or recreational  species;
     •  significant  impairment of  major  uses of the site or adjacent
        areas due  to accumulations of solid waste material;
     •  adverse  effects  on taste or odor of  valuable commercial  or
        recreational species as  a result of  disposal activities;  or
     •  identification on  a consistent basis of toxic concentrations
        of any  toxic waste,  waste constituent  or byproduct at levels
        above normal ambient values outside  the disposal site more
         than four  hours after disposal.
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     These criteria leave open  the possibility for accumulations of toxic
contaminants within the disposal site to a sufficient degree to impair
later harvest of transient  (e.g., pelagic) species passing through the
site and becoming subsequently  available through the food chain to man.
Because of the nature of finfish movements and, to a lesser extent, the
movements of other valued species (e.g., lobsters), there is a strong
likelihood that it would be impossible to detect consistently a direct
link between toxic accumulations in a disposal site and organisms
passing through that site, as required by the criteria.
3.6  Stability Related
3.6.1  Resource Conservation and Recovery Act of 1976  (PL94-580)
     As discussed throughout this report, a key consideration under RCRA
is the identification of a waste as hazardous by EPA, Office of Solid
Waste.  To date, FGC wastes have not been identified as hazardous, and
OSW has announced its intent to place whatever portion of these wastes
is declared to be hazardous in a special category subject to a limited
set of hazardous waste requirements.  With respect to physical stability,
FGC wastes may constitute a potential hazard to personnel during disposal
operations due to liquefaction and loss of structural strength.  As such,
this would be a concern of the Occupational Safety and Health Administra-
tion although they may work closely with EPA to establish protective
measures, which may include treatment, moisture content control, and
control of waste disposition within the landfill.
     Other considerations for the stability of FGC wastes are stated in
two regulations published in the Solid Waste Disposal Regulations and
Guidelines (40 CFR 241); for completed sanitary landfills (§241.203-2(c) :
(1) that the integrity of the final cover shall not be disturbed by agri-
cultural cultivation,  and (2) the recommendation that major structures
are not constructed on the site.  Major structures built near a completed
land disposal site require design approval by a professional engineer.
(This regulation was written in response to the problem of gas production
from municipal and domestic wastes,  not physical stability of FGC wastes.
However, it may be applied to the latter as well.)  The possibilities of
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liquefaction and slumping of FGD sludges placed in fills are significant,
and either one could cause a threat to personnel safety or land quality.
     The owner or operator of a landfill may screen the wastes to be used
in the fill by their exclusion in the permit.   The criteria used in deter-
mining the acceptability of the waste are the hydrogeology, the chemical
and biological nature of the wastes, environmental and health effects,
and personnel safety (i241.201-1).
     Specific approval by the responsible state authority for sludges
with a free moisture content is required because they are a "special
waste" (§241.201-2).  Because complete dewatering of FGC wastes may not
be feasible, this approval implies that states will review most landfill
permits for sites planning to dispose of FGC wastes.  The guidelines state
that the surface and side slopes of all landfills are to be specified in
the permit procedure to promote runoff without erosion and to minimize
infiltration (§241.204-3(a)).  All fill material is to be compacted to
the smallest practicable volume  (§241.210-1).  Inclusion of FGC wastes,
which may settle, slump or liquefy, may very well cause alterations in
completed surface contour, slopes and runoff and drainage  patterns.
Compaction of wastes may induce  liquefaction of sludges,  thereby
endangering personnel during disposal operations.
     In a brief  survey of  the  solid waste disposal regulations  of  several
states, the following criteria  emerged.  In Pennsylvania,  FGD sludges may
be included with fly and bottom ash and  slag in landfills  if  approved by
the Department  of Environmental Resources  (§75.37).   This  state requires
maintenance as  long as necessary after  completion  of  the  landfill  to
prevent health  or pollution  hazards or  nuisances,  to  repair  cracks,
fissures,  slumps and slides,  etc.   In Illinois, the owner/operator shall
monitor and abate gas, water or settling problems  within  three years  of
closure of  the  landfill.   Most of  the state regulations surveyed do not
mention FGC wastes  by name,  nor do  they specify maintenance of final
contour of  the  landfill  following  completion.
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3.6.2  Surface Mining Control and Reclamation Act of 1977 (PL95-87)
     The main objective of this statute is to protect the health and
safety of the public and to minimize damage to the environment.  Section
515 establishes Environmental Performance Standards which set the "approx-
imate original contour" as a goal to aid in restoration of land quality.
Regulations promulgated as of this writing include the interim program
published in the Federal Register on December 13, 1977, and a permanent
regulatory program proposed September 18, 1978 (Federal Register).  Key
issues which are as yet unresolved:  Can FGC wastes be incorporated as
backfill material during reclamation operations at surface mines?  If -
so, will they be classified as a "toxic-forming waste" (or hazardous
material) or as an "acid-forming material" if high in sulfur compounds.
     Backfill materials referred to in the regulations are limited to
spoil, overburden and coal processing wastes.  In §715.14(3) the use of
wastes from other activities outside the permit area is covered but the
wording is unspecific as to the types of wastes that would be permissible;
§817.20(c), which deals with coal processing wastes, defines "materials
from other operations" to exclude non-mining activities.
     If future regulations are promulgated which allow the incorporation
of FGC wastes in backfilled areas of reclaimed surface mines, interim
regulations contain provisions which would have a direct bearing on
physical stability, especially those which deal with achievement of
land quality functions; specifically:
     §784.19      Subsidence Control Plans which "shall describe the
                  subsidence control to be used to achieve compliance
                  with the requirements of subchapter K (Environmental
                  Performance standards)."
     §715.14(J)    "Before waste materials...from other activities outside
        (3)
                  the permit area...are used for fill material, it must
                  be demonstrated to the regulatory authority by hydro-
                  geologic means and chemical and physical analyses that
                  use of these materials will not... cause instability in
                  the backfilled area.
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     §715.14(b)   Deals with the situation where modification of the
                 original slope has been approved by the regulatory
                 authority.  "The permittee shall...be required to
                 (ii) backfill and grade to the most moderate slope...
                 as is necessary to insure stability."
     §715.17(J)   Covers mining in alluvial valley floors west of the
                 hundredth meridian west longitude.  "Surface coal
                 mining operations conducted in or adjacent to all
                 valley floors shall...preserve the essential hydro-
                 logic functions... The characteristics...to be con-
                 sidered include:  (v) configuration and  stability of
                 the  land surface in  the flood plain and  adjacent low
                 terraces in alluvial valley floors as  they allow or
                 facilitate irrigation of  the  flood waters or  subirri-
                 gation and maintaining erosional  equilibrium;
                  (vi) moisture holding capacity  of the  soils within
                 the  alluvial valley  floors and  physical and chemical
                 characteristics  of the subsoils which  provide for
                 sustained  growth or  cover through dry  months."
     The case of acid- or  toxic-forming waste materials  as defined  in
§710.5 is dealt with in  §715.14(j)(1) :
                  "Any acid-forming,  toxic-forming  or combustible
                 materials identified by  the  regulatory authority  that
                  are exposed,  used  or produced during mining  shall be
                  covered with a minimum of four feet of non-toxic  and
                  noncombustible materials...(2)  Backfill materials shall
                  be selectively placed and compacted wherever necessary...
                  to ensure the stability of the backfill materials."
This requirement also applies in §717.14,  the backfilling and grading of
road cuts, mine entry area cuts, and other surface work areas.
     Section  716.7(e)(4)  covers the case of reclamation of prime
agricultural land which is under the jurisdiction of the Department of
Agriculture.   Given the present uncertain status of FGC wastes with
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regard to their hazardous nature, it is probable that the Department of
Agriculture would prohibit the use of such materials in any manner in
such designated areas  (SCS Engineers, 1977).
     An additional stability consideration is stated in §784.15, Dams
and Impoundments, subsection (b)(x):  "Slope stability analyses will be
required for existing and proposed embankment slopes for construction
and long-term conditions... Consideration must be given to the possibi-
lity of landslides into the impoundment..."  Another regulation which
deals with impoundments, which are often used to contain FGC sludges,
is §715.18(a):  "No waste material shall be used in or impounded by
existing or new dams without the approval of the regulatory authority."
This regulation is followed by extensive construction requirements
which include periodic inspections of dams and impoundments.
     If FGC wastes are determined to be legitimate backfill materials,
then the major restrictions in their use will be compliance with the
above-mentioned regulations and also with performance standards aimed
at achieving the "approximate original contour."  Subsidence, whether
through liquefaction or consolidation, may cause violations of the
contour requirement over time, and the threat of landslides may be
realized if proper restrictions and guidelines are not developed.  At
present, the regulatory program does not address this issue although
the foundation has been laid to implement the use of FGC wastes in
mine reclamation.
3.6.3  Federal Coal Mine Health and Safety Act of 1969 (PL91-173)
     This statute  focuses primarily on miner safety while on the mine
property, with respect to disease and safety.  Accident prevention is
stressed; for example, storage of materials, usage of equipment, mining
engineering, and air quality.   The latter include such accidents as gas
build-up, explosions and the cumulative health effects of inhalation of
fugitive dust and  other particulates (e.g., black lung).
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     The disposal scenarios described in Section 2 involve disposal in
an abandoned portion of an underground mine behind an engineered bulk-
head.  Therefore underground mining disposal of FGC wastes is not an
occupational safety issue for miners if performed correctly.
3.6.4  Occupational Safety and Health Act of 1970 (PL91-596)
     The prime responsibility of OSHA covers worker safety, as does
the CMHSA.  In 1974, a memorandum of understanding was published between
MESA and OSHA (Federal Register, July 26, 1974) which established the
exclusive authority of the former on mine property.  OSHA jurisdiction
extends to the storage and handling of materials at power plant sites
and at landfills.  There are safety problems in these circumstances
where FGC wastes are used to support a load (e.g., in a landfill cell)
which could endanger personnel if loss of structural strength occurred.
Liquefaction during materials storage is not dangerous unless the
regaining wall (embankment or container) fails and personnel may be
flooded.  Because liquefied sludges may flow almost as fast as water,
this could be a hazard.  During transportation, vibrations may cause
liquefaction and generate noticeable volumes of interstitial waters.
The OSHA regulation 29CFR 1910.176(d) calls for the provision of
"proper drainage" during storage and handling but not during transporta-
tion.  OSHA would have authority over the  reclamation of  abandoned
mines because no mining activities  are  taking place, therefore,  the
workers would not be subject  to MESA authority.
3.6.5  Dam Inspection Act of  1972  (PL92-367)
     This statute calls for the inspection of  all non-federal dams
over 25 feet in  height, and impounding,  at maximum water  storage eleva-
tions, at least  50  acre-feet.  A national  inventory,  conducted  by  the
Corps, of Engineers  [52],  included "approximately  49,000  dams,  most of
which were privately  owned.   Of these,  approximately  9,000 were identified
as high-hazard,  meaning  in the event  of a  failure,  there  would be  sub-
stantial  loss  of life and property".   An announcement of  the Federal
Program for  Inspection of Non-Federal  Dams was announced  by the White
House  in  December 1977,  and funds  were appropriated for the inspection
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of the 9,000 high-hazard dams.  Findings of each inspection are written
up and the report is sent to the owner/operator of the dam or impound-
ment and to the governor of the state with recommendations as to the
safety of the dam.  It appears that any impoundment meeting the height
and capacity criteria, which is located in a high-hazard area, as
defined above, would be inspected regardless of the material it con-
tained.
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3.7  Land Use Related
3.7.1  Overview
     From the broadest perspective,  the key impact issues concerning land
use are those directly related to the regulation of the location, oper-
ation and final disposition of land-based disposal sites.  The Resource
Conservation and Recovery Act of 1976 is the principal legislation govern-
ing land disposal of waste material.

     The classification of FGC wastes remains a focal issue because of the
implications this classification poses for site selection, operation and
closure,  Furthermore, while speculative at this time, the designation
of two types of solid wastes by RCRA may ultimately alter the manner in
which some local governments control the location of waste disposal sites
within their jurisdiction.  These issues will be addressed in the specific
discussion of RCRA-related regulation.

     The Surface Mining Control and Reclamation Act of 1977  is  important
because coal mines represent a disposal option.  Further, this  legislation
was designed to regulate  certain types of  land use.  As  discussed below,
the degree to which specific regulation promulgated as a result of  this
Act apply to FGC waste disposal, is not  totally  clear.

     From conversations with OSM and background materials included  with
various regulations,  it seems likely   that EPA and OSM may attempt  coordina-
tion of efforts on land disposal of waste  material.   The draft  and/or
untried nature  of most regulatory programs that  can be directed at  solid
waste  disposal  confuses a number of issues,  as noted  below.

 3.7.2   "Resource Conservation and Recovery Act  of 1976", Associated
        Proposed Regulations, and State and Local Regulations
     As discussed  in 6.2.2,  the key regulatory  issue  surrounding the land
 disposal* of FGC wastes  due to the Resource Conservation and Recovery
 *"Disposal"  as defined in RCRA includes:  "...the discharge,  deposit, in-
 jection dumping,  spilling, or placing of any solid waste into or on any
 land or water so that such solid waste or hazardous waste or any constituent
 thereof may enter  the environment  or be emitted into the air or discharged
 into any waters,  including groundwaters."
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Act is the ultimate designation of these sludges as "hazardous" or "non-
hazardous."  The discussion below ignores this issue other than to address
the requirements for disposal under either designation.
3.7.1.1 "Standards Applicable to Owners and Operators of Hazardous
        Waste Treatment and Disposal Facilities" (Proposed December 18. 19781)
     RCRA provides ultimate federal regulatory authority over hazardous
waste disposal, although states may administer federally approved programs.
Key land use issues indicated by the proposed standards were derived from
discussions of:
     •  General site selection*
     •  Technical requirements for closure and long-term care ,
     •  Landfills»
     •  Surface impoundments >
     •  Basins, and
     •  Landfarms•
     Overall, there are significant financial liability provisions and
closure costs to ensure environmentally sound disposal of wastes.  Key
elements of the issues listed above are:
     General Site Selection - Most of  the mandatory standards are con-
cerned with removal from and avoidance  of public areas  and environmentally
sensitive areas.  These latter include  wetlands, permafrost areas, critical
habitats, etc. with some excepted cases.

     Closure and Long Term Care - This  section makes mandatory  the require-
ment that the closed site land is "amenable to some productive  use."
Closure procedures must insure that waste cannot be contacted by  human
or animal life and that discharges of waste harmful to  health or  the
environment do not occur.  The type of  cover  (e.g., one that minimizes
or eliminates infiltration of water, supports vegetation, prevent sub-
limation, etc.) is one such requirement.  For landfills or other  sites
where waste remain, future use cannot include residential, agricultural,
or other use which could disturb the "integrity" of the closed  site.

     Landfills. Surface Impoundments, and Basins - These must be  located
and operated to prevent direct contact with surface water, and  the borders

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of the site must be at least 150 meters from a water supply.   The landfill
must be at least 1.5 meters above the historically high water table.  These
requirements place constraints on location of sites and thus  may be con-
sidered land use issues.

     This discussion has only highlighted specific requirements of the
standards for disposal of hazardous materials.  Should some FGC wastes be
designated hazardous, the main land use issue appears to be whether or
not sufficient facilities can be found for the traditional disposal of the
volumes  anticipated.  One question  is  how  the designation  "hazardous"
will affect the location of sites.  In some parts of the country, there
is difficulty in locating sites even for the disposal of municipal refuse.
In more highly congested areas, traditional dumps have often been located
at or near less desirable development  land (e.g., wetlands).  There is
also the economic question of what  increase in cost  the specific new
requirements represent, and how much of an impact  that would have on
operators, especially those in the  private sector.   It would seen that
this would compound  the site location  difficulties and problems of waste
volume.  These are in addition to specific issues  raised by  the legal
requirements listed  above.

 3.7.2.2  "Criteria for Classification of Solid Waste Disposal facilities"
      (Proposed  February 6^  1978)
     Proposed "Criteria for Classification of Solid  Waste  Disposal  Facilities"
were published  in  February  1978 while  the  final criteria have  not been
published  to date.   The criteria  listed must  be  followed  for the  location,
design,  construction,  operation,  completion,  and  maintenance of disposal
facilities if they are to  be  classified  as posing "..*  no  reasonable pro-
bability of adverse effects on health, safety, or the environment."

      Key land use issues covered  by these criteria include protection of
 environmentally sensitive areas,  such as wetlands, critical habitats,
 permafrost regions,  and sole  source aquifers.  Restrictions relevant to land
 applications of waste material prevent spread of disease and contamination
 and ensure safety.  The major issue for  the disposal of non-hazardous
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materials  is  the  eventual  adoption by all  the states of these or similarly
protective criteria.   In Section  3.3 state existing regulatory programs
are reviewed,  all of  which were developed  prior  to RCRA criteria or
guidelines.

3.7.2.3  Title 40.  Part 256  -  "Guidelines  for Development  and Imple-
         mentation of State  Solid Waste Management Plans"
      The guidelines for approval  of state  plans are still  in draft form,
thus  a number  of  changes could occur before the final guidelines are pub-
lished.  A key issue  can be  identified from these draft guidelines and
the discussion of  EPA's interpretation of  their intent (included as back-
ground with the draft).  First of all, it  is noted that while it is not
the intent of  the  guidelines to supplant private sector initiatives in
solid waste disposal,  some state  initiatives may also be needed.  This
appears, in part, as  a recognition of the  difficulty in locating disposal
sites in some  regions.  The  EPA (in the discussion preceeding the guide-
lines) recognizes  the  local  or regional role in site selction and/or
acquisition.   However, it is an explicit intent that states explore options
for more direct control over siting and facility development.  Of particular
interest is the following quotation (page  23 of the draft):

     "EPA invites comment on methods for the state to obtain greater
     control over facility acquisition.  Such methods could include
     obtaining  the authority to override local zoning laws or to
     contract  directly for facilities and  services requiring facility
     permits to conform to regional plans  developed under  the state
     plan,  or  instituting a public utility agency to regulate the
     supply of services."

     It is difficult to predict the outcome of such suggested control.
While sufficient sites for disposal remains a very important issue, it
does not appear that it can be dealt with other than to recognize its
significance and to follow the progress of state plan development.

     An additional issue was noted in EPA's interpretation of the intent
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of these guidelines.  It suggests coordination with the Department of
the Interior for an inventory of mining wastes which would include aban-
doned lands.  It is suggested that this coordination might also increase
the use of sludges (unspecified) in reclamation of abandoned mining lands,
noting that DOI will provide states with funding for reclamation once they
have approved enforcement programs for activating sites.  It appears
that OSW and the DOI are considering abandoned locations for the disposal
of sludge (with possible financial support).

3.7.2.4  State and Local Issues
      It  is  evident that state solid waste plans will probably
undergo  at  least  some modification in those states  applying for
EPA approval in light to the final guidelines established by RCRA.
The degree  of modification will depend on the differences between
existing state plans and interpretation of  the requirements estab-
lished by  federal criteria  and  guidelines  (and yet  to  be finalized).

     Location of  land disposal  sites,  as a  land use issue,  is  typically a
decision left to  local prerogatives.   Where zoning  exists,  landfills  can
be  included as "conditional  uses"  making them subject  to  review  by some
municipal authority, while,  in  some cases,  "garbage dumping" or  even
open dumping is prohibited.  Many  local communities also  have  performance
standards:  usually a general list prohibiting uses that  produce noxious
odors, noise, air pollution, water pollution,  etc., (sometimes at a
specific level) with the determination of compliance left to some muni-
cipal  authority.   Where sanitary landfills  are included as  a conditional
use,  local  requirements concerning buffer zones  and access, as well as
final cover and reclamation may also  be listed.   These can  be  in addition
to  existing state permitting requirements or regulations where the latter
exist.

      As  with other levels  of disposal regulation, the  major issue surround-
  ing local  regulation of landfall  sites is  the local availability of  sufficient
 sites for the land disposal of  FGC Wastes.   With site  designation left
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 under local  control,  local  citizen pressure,  competition  from  other more
 lucrative  land  uses,  historical  precedent  or  practices, and  land  availa-
 bility could all  be  important.   Evolving state authority  over  the loca-
 tion  of sufficient disposal capacity  for the  state,  if implemented, could
 alter the  significance  of this issue  somewhat, but  this would  represent
 a  new role for  state  government.   Furthermore, it would appear that
 designation  of  FGC wastes as hazardous would  compound the problem from
 the standpoint  of local acceptance as well as the earlier mentioned eco-
 nomic standpoint.

 3.7.3  Surface Mining Control and Reclamation Act of 1977 and Associated
      Regulations
      The Surface  Mining Control  and Reclamation Act  is relevant because
 surface and  underground mines are  being considered  as options  for FGC
 waste disposal.  SMCRA  can  be viewed  as a  land use  law — in essence,  it
 is directed  toward preventing practices that  (in addition to posing a
 threat  to  human health)  degrade  environmental quality.  It establishes,
 for most situations,  requirements  for reclamation of mined land to its
 pre-mining capabilities.  The Act  itself does not prohibit or  allow for
 the disposal of wastes  generated by other  than mining practices.  For the
 purpose of identifying  land use  impact issues related to  this  law, it  is
                                                                •
 assumed by the  authors  of this report that disposal of sludge wastes  in
 surface or underground  mines would have  to meet  the objectives of the Act
 and  the requirements of specific regulations.

      The Act  includes performance  standards which provide the  framework
 for promulgation  of a minimum set  of  regulations.   Interim regulations
 are presently in  effect  and the  permanent  regulatory program was  proposed
 on September  18,  1978,  Federal Register.   The standards include operational
 procedures that are directed toward the protecton of surface and  ground-
water quality and quantity,  and  control of erosion and air pollution.
 They  are also directed at reclamation procedures that, in addition to
providing  the above protection and/or control, are aimed  at  returning
mined land to a condition capable  of  supporting the pre-mining  or "better"
use.
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     The term "wastes," without modifiers,  is not defined in the Act.
There are a number of performance standards that could,  if interpreted
literally, be applied directly to a number  of disposal options for FGC
sludges in or at the site of surface or underground mines.  These include:

     •  The stabilization of all surface areas affected by reclamation
        to effectively control erosion, and air and water pollution;
     •  The treatment, burial, and compaction or other form of disposal
        of other debris, acid forming materials and toxic materials* in
        a manner that would prevent contamination of ground or surface
        waters; and
     •  The surface disposal of wastes in waste areas (other than
        excavations) only when they can and will be stabilized and
        revegetated.

     If the feasibility of sludge disposal in surface or  underground mines
is assumed, the implications of  the following standards  (reflecting
objectives) should be  considered:

      •   The approximate original contour of the disturbed  land must be
          restored  (with exceptions) and stability  ensured.
      •   The reclaimed area must be revegetated with  a  diverse  permanent
          vegetative  cover of  the same  seasonal  variety  native to  the  area
          (there are  alternate use  exceptions).
 *Two definitions  of  toxic  materials  are  found  in the Surface Mining En-
 forcement  Provisions.
 "Toxic-forming materials means  earth materials or wastes which,  if acted
 upon by  air,  water,  weathering,  or microbiological processes, are likely
 to produce chemical  or physical conditions in  soils or water that are
 detrimental to biota or uses  of water."
 "Toxic-mine drainage means water that is discharged from active or aban-
 doned mines and other areas affected by  coal mining operations and which
 contains a substance which through chemical action or physical effects
 is likely to kill,  injure, or impair biota commonly present in the area
 that might be exposed to  it."
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      •  For "prime agricultural" lands, if replaced top soil horizons are
        altered,  they must be equally or more favorable for plant growth/
        productivity  (compared to local "reference" areas).  There are also
        special restrictions for mining (and reclamation) in alluvial valley fl
      •  Acid or other toxic drainage to surface or  groundwater systems must
        be avoided by treatment of drainage or of preventing contact with
        toxic materials.
      Interestingly, it appears that the standards for permanent water
impoundments, if  interpreted literally, could include the ponding type
disposal option for FGC wastes.

      As part of the permitting requirements, mining operators must prepare
mining and reclamation plans that outline procedures to be taken for com-
pliance with this law.  In addition, a performance bond must be posted as
insurance against non-compliance.  The implications of sludge waste disposal
in adding risks (if any) to the operator, especially where acid mine
drainage is not a problem, are not clear.  It would appear that problems
arising from this additional liability could range from simple procedural
ones, to rejection of sludge disposal by the operator.  Discussion with
the OSM has indicated that they believe the operator would remain liable although
positions on waste disposal in general have not yet been established.

3.7.3.1  Interim Regulations - Final Form
     The interim regulatory program defines "wastes" restricting that
term to "earth materials" associated with the coal mining/cleaning pro-
cess.   This would, therefore,  not include FGC material.  However, a
single overall statement does  encompass disposal of materials other than
the defined wastes,  this would allow for the use of FGC wastes as fill
under the following provision:

     that it "...must be demonstrated to the regulatory authority by
     hydrogeological  means and chemical and physical analyses that use
     of these materials will not adversely affect water quality, water
     flow and vegetation;  will not  present hazards to public health and
     safety and will  not cause instability in the backfilled area."
     (715.14(J))
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     In conversation with OSM,  it was indicated that the above quoted
overall statement was included  as an "umbrella" to cover contingencies
not yet fully considered.  The  indication was that a series of "position
papers" would follow after the  full regulatory program is in effect.

     The interim enforcement provisions, now in effect, provide perfor-
mance standards for both mining operations and reclamation.  Below is
a brief outline of reclamation  performance standards which would appear
to be most directly applicable to disposal of sludge material in surface
or underground mines.  It must  be emphasized that OSM apparently intends
to evaluate, establish, and clarify their position on requirements related
to such disposal at a later date.  Thus, the applicability of some stand-
ards remains unclear.

     1.  Post-Mining Use of Land.  Disturbed areas must be restored  to a
condition capable of supporting pre-mining use; or  "higher or better" uses
where the proposed alternative, among other requirements,  is  designed
to conform with applicable standards for adequate stability,  drainage,
vegetative cover, and will not pose any actual  or probable threat  to
waterflow reduction or pollution.  The main issue here  is whether  or not
disposal of FGC wastes would have  an affect on  the  standards.

     2.  Backfilling and Grading.  All  spoil material  must be backfilled
and  compacted  where  it  is necessary  to  ensure  stability,  or  to  prevent
leaching of  toxic material,  and  then graded.   There are also specific
requirements for  grading of  slopes (with  exceptions for high and low over-
burden ratios.  The latter  may need to be considered for FGC waste disposal)
Several additional  standards are included in this section:

     (a)  Permanent Impoundments.  Impoundments may not be constructed
          on top of areas where excess materials  are disposed.  It is
          yet unclear whether or not this would include "sludge  as fill"
          material, although later in this section  it requires that  all
          toxic materials have to  be covered so that there is no leaching,
          etc.
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    (b)  Covering Coal and Acid-Forming, Toxic-Forming, CombustibleT and
         Other Waste Materials.  All material remaining after mining that
         might be toxic-forming, etc., must be covered by a minimum of
         four feet of non-toxic, non-combustible material.  It necessary
         such material has to be treated to neutralize the toxicity in
         order to prevent water pollution or to minimize adverse affects
         on plant growth, land use, etc.  In addition, the standards
         require the toxic forming material shall not be buried or stored
         near a drainage course so that it would pose a threat of water
         pollution.

     (c)  Stabilization.  Backfilled materials have to be either placed or
         compacted  (if necessary) to prevent the leaching of toxic-forming
         materials into surface or ground waters.

    (d)  Use of Waste Materials as Fill.  This paragraph was cited in the
         discussion above as being the statement that covered the use of
         wastes other than mining wastes as fill, provided it could be
         demonstrated that no adverse affects would occur.  It is this
         overall statement  that  is pending  further definition by  the
         Office of  Surface Mining.

     3.  Disposal of Spoil and Waste Materials in Areas Other than Mine
Workings or Excavations.  There are specific requirements for how spoil
materials or waste materials are to be disposed of.  However-, it is not
clear that these could apply to wastes other than mining wastes.  These
requirements are specifically ones for ensuring stability and prevention
of leachate to subsurface waters, etc.  Evidently, additional standards
for this type of waste disposal are included in the draft regulations that
have not yet been received in-house.

     4.  Revegetation.  The major requirement of this section is that
vegetative cover will be able to stabilize surfaces and prevent erosion.
In addition, revegative cover must be diverse, permanent, and of species
native to the area.  These standards are general with special ones applied

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to prime agricultural land.   In the latter case,  there are very specific
requirements for top soil handling, etc.

     There is an entire section of special performance standards for such
situations as prime farmland, mountain top removal,  etc.   Most of these
are operational requirements and as they are special situations, it is
not clear how much, if at all, they would apply to FGC waste disposal.  It
is questioned whether prime farmlands cou?d be considered at all.

     There is also a section of underground mining performance standards.
A review of this section indicates that standards are very similar to
those listed above for surface mining.  These standards are directed at
surface operations for underground mines, and additional standards are
forthcoming.  The standards do include covering of toxic-forming materials
and backfilling and grading, protection with hydraulic systems,  etc.

     In summary, two major  land use  issues  can be derived  from this dis-
cussion of  the Surface Mining  Control and Reclamation Act  and  subsequent
regulations.  The  first  is  the degree to which the requirements  of  the  Act
and regulations apply  to FGC waste disposal at a  mining  site.   As  that
issue has not yet  been resolved by the Office of  Surface Mining,  the
second  issue is the degree  to  which disposal of sludges  in mined areas
would prevent compliance with  the existing  performance standards for
reclamation.

3.7.3.2   Permanent Regulatory  Program
      The interim  regulations that are presently  in effect can be administered
by states under their existing permit programs.   Once, the full regulatory
program is  in effect,  however, states will have  to,  in many cases, revise
 their surface mining rules and regulations to comply with the requirements
of the complete federal regulatory program in order to be approved.

      Additional land use related requirements that might affect disposal
 of FGC wastes are not specifically included (although there are additional
 air and water requirements that will be dealt with elsewhere).  Certain
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requirements of the final regulatory program are worth noting, however
mostly because they do pertain to either special regulations for certain
mining sites or indirectly to economic requirements of mining operators.

     Extensive requirements will exist for operators before a permit will
be granted.  The most pertinent ones surround the requirement for a re-
clamation plan.  Such requirements include the plan for controlling the
surface and groundwater drainage, plan for treatment  where it is
required, a plan for restoration of water recharge capacity where
required, a plan for collection and reporting of ground and surface
water quality and quantity data, a plan for a description of measures
that will be taken to ensure that debris, acid-forming and toxic-forming
materials will be disposed of in accordance with the Act, and finally,
an estimate of the cost of reclamation.  This latter requirement is im-
portant because a bond has to be posted to cover liability for the area of
land affected by surface coal mining and reclamation operations under the
permit (bonds are posted in one-year increments).  These requirements would
appear to make it essential to understand the implications of waste dis-
posal in terms of operator liability.

     In the section,  "Disposal of Non-Coal Wastes", of the discussion report
of the proposed permanent rules (43FR41767),  the following quotation is
relevant:

     "Another alternative which was reviewed concerned the utilization
      of surface mines for approved, centrally located sites for dis-
      posal of non-coal wastes by other mines, other industries, and
      even municipalities, in are?s where suitable, physiographic and
      hydrologic conditions did not provide sufficient alternative
      disposal sites.  The proposed regulations do not specifically
      address this issue, and public comment is solicited on the
      appropriateness of opening mine sites to outsiders for dumping."
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     A similar approach is suggested for the use of deep mines as disposal
sites with the comment added that OSM is soliciting suggestions on the
appropriateness of underground mines for disposal, as well as any dif-
ferences which should be considered between underground and surface mine
workings.

3.7.4  Land Use Considerations under State  Solid Waste Management
       Regulations
     A telephone survey of the ten EPA regions resulted in the selection
of eight state solid waste regulations for review.  As surface water,
groundwater and stability  considerations  have  been dealt  with in Sections
3.2,  3.3 and  3.4,  this  review will  focus  only  on  land use considerations.

     The following review  focuses on three  types  of land  use  considerations:

     •  The types of regulatory control,
     •  The disposal site  location  requirements,  and
     •   Closure and post-closure requirements.

     While specific examples  of  types  of  regulation from  specific states
are  cited, they are intended  to  be  exemplary only.  In other  words,  such
examples are  not  intended  to  represent the  best approaches, or the only
approaches to these various land use-related considerations.   However,  on the
whole,  examples were  chosen to  illustrate the  more restrictive requirements.

      1.  Types of Regulatory  Control.   Review  of  selected state  solid
waste management  legislation  indicates that for non-hazardous waste
material criteria or  standards  for  the handling,  disposal,  etc., are
established at the state level.  However, solid waste management plans
are  typically developed at a  more  local level  (regional,  county, etc.)
with variable state  involvement.   Several approaches are illustrative.

      •   Under the Texas Solid Waste Disposal Act   (Ch. 405, Art 4477-7
         1969  as amended) every county in the state has solid waste manage-
         ment  powers  and may develop county solid waste plans.  Under the
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   Texas Municipal Solid Waste Management Regulations  (1975. amended
   1977),  the Department of Health Resources policy on land use is
   given,  "...regulations shall be prepared incorporating statements
   which will guide applicants for solid waste permits toward the
   selection of sites remote  from public concern and encourage in-
   novative management procedures such as recycling, land improvement
   and the generation of energy.  Further, the intention of the
   applicant shall be directed to the absolute necessity for land use
   compatibility of solid waste facilities with other land uses
   within  the impact area of  the proposed site." (Section A-5.)  There
   is a note that the Department supports the decision that land
   use matters be managed by  local government.

•  Under Chapter 75 of the Solid Waste Management Rules and Regulations
   (Title  2, Ch. 75, 1977),  of the State of Pennsylvania, municipa-
   lities are to submit plans to the Department of Environmental Re-
   sources, including (a) resolution drafts and drafts of ordinances
   contracts, and agreements  that indicate the plan can be implemented
   and (b) a summary of solid waste problems including future con-
   straints expected to influence either solid waste systems such as
   available land, physical limitations, transport facilities, pol-
   lution regulations, or land use regulations, etc.

•  The New Jersey Solid Waste Laws (Ch. 39, 1970 as amended), esta-
   blish within the State Department of Environmental Protection, the
   authority to formulate and promulgate rules and regulations con-
   cerning solid waste collection and disposal.  All the counties
   and the 14 community Hackensack Meadowlands District in New
   Jersey are designated solid waste management districts and
   develop their own waste management plans.   Significantly, in
   cases where a district has established that there are insuffi-
   cient existing or available sites for solid waste facilities
   and that there are difficulties in finding available space,
   state level authority for intervention in disposal site loca-
   tion is authorized by this act.
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     As with federal regulations,  state level control over hazardous waste
disposal is far more stringent than for non-hazardous waste.   The degree
of state level control varied among the state regulations reviewed, as
illustrated in the two examples below.   The second example  appears to
be a far more typical approach.

     •  In the State of Oregon, environmentally hazardous waste cannot be
        disposed of on any land other than real property owned by- the State
        of Oregon, and designated as a disposal site.  Under the Oregon
        Solid Waste Control Law (Ch. 409, 1969, as amended, Section
        459.580) the licensee of a hazardous waste disposal site must
        deed to the state (for reimbursement) the portion of the site in
        or upon which hazardous wastes have been disposed of as a  con-
        dition of the issuance of a license.

     •  Under Texas Solid Waste Disposal Act  (op  cit);   The State  Solid Waste
        Agency has  the responsibility  to control  all aspects of  industrial
        solid waste collection, handling,  storage, and  disposal.   Where
        both municipal and industrial  solid wastes are  involved,  then the
        agency has  jurisdiction over the activity.

      2.   Disposal Location Requirements.   Review of selected  state
 solid  waste management legislation and regulations  indicates  that  criteria
 and/or standards  (especially for  hazardous material) are established at
 state level,  but  approaches  vary.  Two approaches are illustrated below:

      •  The State of  California has published a manual  for disposal site
         design.*   Essentially, this manual establishes  classifications of
         wastes by impact potential and classification of disposal sites
         by their  ability to  attenuate such impacts.   If FGC wastes were
         classified as "Group I"  wastes, their disposal would have  to be  at
         "Class I" sites:  those that provide maximum protection from leaching
 *Waste Discharge Requirements for Non-sewerable Waste Disposal  to Land,
 California State Water Resources Control Board, January  1978.
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         and certain forms of runoff problems through occurring geological
         conditions.

      •  In a draft  of Tennessee's  Hazardous  Waste  Management Regulations
         (August,  1978),  site permit applications are very  specific.   Such
         requirements  include contour maps  that  show  land use patterns and
         zoning within 2,000  feet of the  facility,  a  preliminary geologic
         and hydrologic review of the area  within 5,000  feet of the site
         the life  of the facility,  the  chemical  and physical characteristics
         of the waste  to be disposed of as  well  as  transformations and/or
         residuals,  and an outline  indicating the plan of construction
         sequence  for  the proposed  site,  and  closure  plan.

      The "hazardous"  site requirements or  permit requirements  are used
 as  examples as they are,  in  general, far more specific  than those for
 non-hazardous  waste disposal facilities.   The latter, would typically be
 regulated by local  codes,  which generally  contain  "nuisance regulations,"
 but  in some cases include environmental  performance  criteria borrowed
 from state guidelines.

      3.   Closure/Post-Closure  Requirements.  Minimum standards  for site
 closure  are typically included in  the  selected  regulations reviewed.   These
 include  final  slope or stabilization requiiements, cover and revegetation
 requirements for all  types of  sites.   Monitoring,  treatment of  runoff or
 its  accommodation by  surface drainage, maintenance of liners,  and require-
 ments  for  underground drainage, exemplify  requirements  for hazardous  waste
 disposal sites  found  in  a number of state  regulatory programs.   A number
 of states  have  also established bond requirements  as insurance  that clos
 requirements are met  and  long-term maintenance  can be required  in some
 states for certain types  of  disposal situations.

     Of  the regulations reviewed,  only one state,  Kansas, established post-
 closure  requirements  for  site  land  use planning, and even here  this was fn
                                                                          "'•
hazardous  solid waste disposal sites only.  The Kansas regulatory program
 (Article 29) establishes requirements whereby restrictive convenants  may
be made of the facility after closure,  specify the period for which
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restrictive covenants apply,  or describe modifications that could be
Initiated by property owners  so that other land uses could be established.
It is possible that understanding of the characteristics (i.e., risk-
potential) of re-use of hazardous waste disposal sites would make such
requirements infeasible for hazardous waste facilities.  In fact, similar
language is not used in the hazardous waste regulations for Kansas.
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3.8  Air Related
     Activities associated with the handling and transport of FGC wastes
accelerate drying  (solids content ranges from less than 10% to 60%) and
increase the probability for the creation of fugitive air emissions, i.e.
suspended particulates which are not emitted through a stack.  It is these
emissions which have become a concern of regulatory agencies.
     As discussed  throughout this section under RCRA, FGC wastes are
provsionally considered "special wastes".  However, it appears likely
that they will not all be subject to the full set of hazardous waste
regulations, particularly the design standards of Section 3004.
     Section 1006 of RCRA directs EPA to integrate to the maximum extent
practicable all provisions of RCRA with appropriate provisions of the
other Acts of Congress which give EPA regulatory authority.  One of the
ways EPA has chosen to integrate RCRA with the Safe Drinking Water
Act (SDWA), the Clean Air Act (CAA), and the Clean Water Act (CWA) is
through the use of Human Health and Environmental Standards.  Each of
them - the groundwater, surface water, and air standard - establishes an
overriding standard for treatment, storage, and disposal facilities by
incorporating relevant limitations established under those acts.
Since the primary pollutant generated by FGC wastes is suspended particu-
lates,  the Clean Air Act as amended (CAA) would apply.
      Prior to  1978,  all dust generated in earth-moving and materials
  handling during FGC waste disposal would have been considered fugitive
  dust  emissions.   However,  the prevention of significant deterioration
  (PSD)  regulations established in 1978 by EPA under the Clean Air Act of
  1977  clearly  defines fugitive dust as consisting of "particles of native
  soil  which is uncontaminated by pollutants resulting from industrial
  activity." Particles so defined are not subject to PSD regulations in
  FGC disposal  activity.  This implies that only the fugitive emissions of
  FGC wastes, per se, and any dust generated in the handling of aggregates
  used  in FGC waste treatment,will be considered in PSD increment deter-
  mination for  new waste handling, treatment, and disposal facilities.
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However, if these activities occur on the utility site,  they may be
reviewed in the larger context inclusive of  stack emission from the plant
itself.  The (PSD) regulation applies only to particulate and sulfur
dioxide pollutants at this time and establishes the area classifications
and limits for increases (increments) in concentrations  of these pollutants
above existing levels as shown in Table 3.6.
      Class II PSD provisions  of  the Clean *\ir Act  Amendments apply to
 most areas of the country designated by states as  being in attainment
 of National Ambient  Air Quality  Standards,  except  for areas initially
 designated Class I.   Numerous permit requirements  are now mandated
 by law for certain modified stationary sources (greater than 100 tons
 per year (tpy) potential uncontrolled emission rate).

      Permit review needs are  considered according to  the level of
 technical review needed; PSD  regulations allow for three levels of
 permit evaluation.  Level I permit applications are sources which are
 not subject to non-attainment or PSD review because the emission rate
 is below the statutory cutoffs or reductions in emissions are expected.
 Applicants are subject to State Implementation Plan (SIP) and/or New
 Source Performance Standards (NSPS) review.  New source applicants
 deemed subject to non-attainment or PSD review are made aware of
 measures that would eliminate non-attainment or PSD review.  Such
 measures could include site relocation, sulfur restrictions in fuel,
 emission standards tighter than the SIP or NSPS and process equipment
 changes that are less polluting, among others.

      Finally, Level  III permit applications, where predicted ambient air
 concentrations are significant after Level II screening, are referred for
 review  by  dispersion modeling.  If  the modeling indicates  that particulate
 emissions,  for  example, will  cause  or  contribute  to ambient air  concen-
 trations  which  exceed  the maximum allowable  increases  for Class  I areas,
 the  state may still  issue a  permit.   However,  the emitting facility must
 give assurances that  its  emissions  together  with  all other sources will
 not  exceed the  maximum allowable  increases over baseline concentrations
 stipulated for  Class II areas for  particulates.
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                                 Table 3.6

                PSD Limits on Increases-in Pollutant Levels
                                  (yg/m )

Basis:  All numbers in microgram per cubic meters
so2


TSP


Annual
24-Hour
3-Hour

Annual
24-Hour
Fe
Class I
2
5
25

5
10
rmitted Incre
Class 11
20
91
512

19
37
ments
NAAQS
	 	 	 T*—
Class III NAAOS
40
182
700

37
75
80
365
1300(s)

75 60(s)
260 150(s)
  Note:   All  24-  and  3-hour  values  may be  exceeded
         once per year.

         NAAQS:   National  Ambient Air  Quality Standard
                 (Primary)
 Source:   [53]
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     In absence of a definitive precedent,  it is difficult to assess
the specific regulations applicable to FGC  disposal facilities.   For
example, if the disposal site and operations are considered part of a
fossil-fuel fired steam electric plant, the emission cutoff rate for
PSD review is 100 tpy,  otherwise it is 250  tpy.  Further, if the disposal
facility is considered part of the fossil-fuel fired utility, and the
utility has "converted (to coal) from the use of petroleum products,
or natural gas, or both," then "for purposes of determining compliance
with the maximum allowable increases in ambient concentrations" of
particulates, the particulate emissions are not taken into account.
     The question as to whether or not the FGC disposal facility and
activities are to be considered one of the 28 major emitting facilities
is critical to an understanding of which federal and/or state SIP
regulations are applicable.
     In "non-attainment" areas, i.e.,  those areas where Federal A.mbient
Air Quality Standards have not been attained, new FGC waste  disposal
activities could be subject to a review procedure including  "emissions
offset" considerations.  These considerations,  if applied  by the responsi-
ble permitting agency, would involve  the implementation of equal or
greater reductions of existing emissions of  the pollutant  of concern as
a  tradeoff to allow the emissions  increment  associated with  the proposed
disposal activity.
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3.9  National Energy Act of  1978
     In 1978 the National Energy Act  (NEA) was passed by Congress and
encompassed five separate bills:

     •  National Energy Conservation  Policy Act of 1978
     •  Powerplant & Industrial Free  Use Act of 1978
     •  Public Utilities Regulatory Policy Act
     •  National Gas Policy Act of 1978
     •  Energy Tax Act of 1978

     At present, detailed regulations to implement the overall frame-
work of NEA are being worked out by the Department of Energy (DOE).
The regulations would promote the use of coal, renewable energy
sources, and other alternative fules  over oil and natural gas wherever
possible.  While the full impact of NEA on utility and industrial
power plants needs further definition, the following appear to be
indicated:

    a-  All new boilers, gas turbine and combined cycle units
        with a capacity larger than 10 MW will be prohibited
        from using oil or natural gas unless specifically exempted
        by DOE.
    b.  Existing facilities that are coal capable but not using
        coal now may be required to switch to coal or an alternative
        fuel.   Financial capability to use coal or alternate fuels
        will be considered by DOE.  DOE will consider exempting an exist-
        ing boiler without the furnace configuration and tube spacing
        to burn coal.   However,  addition of particulate and FGD
        systems  may not be  considered substantial modification
        preventing a switch to coal.   Furthermore, derating  of
        less than 25% by switching to coal will not  be considered
        substantial.   These regulations will apply to single units
        of 100 MMBtu/hr or  more  or multiple units in one site which
        is aggregated by design  capable of a fuel input rate of
        250 MMBtu/hr or more.
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     It is anticipated that NEA will encourage use of coal over the
next twenty years.  Additional solid wastes and wastewater will be
generated by a switch to coal.  Focus on these incremental problems
is under RCRA.  As regulations under NEA and RCRA develop further,
proper meshing of these to meet the overall objectives of a national
switch to coal and environmentally sound disposal of coal-related
wastes is essential.
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4.0  ENVIRONMENTAL IMPACT CONSIDERATIONS
4.1  Introduction
     This section consists of an evaluation of  the results  of  previous
and ongoing assessments of the environmental impacts of FGC waste dis-
posal.  As summarized in Table 2.5,  there are some ongoing  field-scale
environmental studies of FGC waste disposal.  As may have been seen
throughout the text below, there are very few published results of
completed field-scale studies of this subject.   Thus, much  of  what
appears in this report is evaluation arrived at by combining the knowledge
gained from FGC waste characterization studies (Volume 3) with the
emerging results of ongoing field-scale studies.
     The focus of this evaluation is the set of potential impact issues
identified in Section 2.4 above.  In addition to attempting to
prioritize this evaluation for each disposal option as described in 2.4
attempts have been made to point out, wherever possible, the degree to
which the potential importance of various  issues remains unresolved in
light of the assessments  to date.  Further, attempts are made  to
characterize the degree to which planned research may  be expected  to
resolve  these issues.  Finally, remaining  unresolved issues are  linked
to future research needs  on  the basis of the apparent  magnitude  and
uncertainty of their  impact  potential.
     As  an overview of all  the  text  that follows,  it is most  important
to remember that  there are  no universally  significant  environmental issues
for  all  FGC waste  disposal  options at all  disposal sites.   The significance
of each  issue  for  any given disposal operation tends to  be a  site-specific
function of  three  variables:
      •   Waste  characteristics,
      •   Disposal  practice,  and
      •   Nature of  the receiving environment.
  Thus, impacts are site-specific and cannot be  easily  generalized  over  a
  region.   Furthermore, the  existing  regulatory  framework,  if  successfully
  implemented,  could  prevent or minimize significant adverse  impacts.
  Against this  background, some  broad generalizations on the potential
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environmental issues can be made on a regional or national basis.  Poten-
tial impacts are assessed on the disposal by the major potential disposal
option of ash and FGD waste.
4.2  Land Disposal
4.2.1  Physical Stability Overview
     Stability of a given disposal option can be viewed from the perspec-
tive of normal versus abnormal impacts.  Normal impacts are deterministic,
that is, they can be expected to occur under usual conditions.   Abnormal
events, however, are probabilistic.  Such events are defined as those
which are not part of planned occurrences associated with the operation
or post-closure activities at the disposal site.
     In the present case, abnormal events which may affect site/sludge
stability involve vibration, liquefaction and inundation of the site.
These events include earthquakes, presence of heavy machinery,  high local
traffic volumes, flooding, and altered runoff or groundwater flow patterns.
Good design and proper operation practices can reduce the probability of
these events occurring and while it is impossible to reduce it  to prac-
tically zero, it must be emphasized that with good engineering practices,
the state of the art is such that the impacts which will occur  under
normal circumstances are minimal.  Good engineering and operations will
be considered separately for each of the three land disposal options.

Wet Ponding
     In the normal course of events, FGC wastes disposed of by  ponding
will be exposed to the effects of weather:  freezing, thawing,  evapora-
tion, precipitation and runoff.   The resulting impacts upon stability of
the waste are also determined by operational procedures in effect at the
particular site.  Thus, the soundness of engineering decisions  on site
operations determine the extent of impacts.  The question of post-closure
use of the site will weigh heavily in engineering decisions, along with
economic considerations (which are dealt with in Section 6). This
issue becomes in reality,  a public policy issue, considered under "land
use" in this section.
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     Good engineering begins with an understanding of  the  processes work-
ing in and upon the medium at hand and then in taking  advantage  of  them
to obtain the desired results.  The ponding disposal option involves  two
sets of processes—bulk physical properties of FGC sludges and grain
properties, both physical and chemical.  The potential  physical impact
issues for FGC wastes are settling, liquefaction and dewatering.   The
grain properties of interest are bonding of the weaker and the pozzolanic
types and those resulting from grain morphology (size  and  shape).
     While it is broadly true that crystal morphology  and  the sulfate/sulfite
ratio in FGC wastes do impact on physical properties,  no direct relation-
ship has been demonstrated.  In the wastes tested and  reported in the
literature, sulfite wastes have tended to consist of platy particles  of
smaller size than rounder sulfate particles.  Because  of these differences
in particle size and morphology, sulfite wastes have tended to be more
compressible, weaker, harder to dewater but less susceptible  to liquefac-
tion failures than sulfate wastes.  If sulfite particle size  and shape
were altered to resemble sulfate particles, less differences  in behavior
may be observed.  In the field, with possible interactions and alterations
in both sulfite and sulfate particles, the situation would be much more
complex.  At present, only indirect indications of behavior as a function
of sulfite/sulfate ratio have been  developed.
     Consideration of the  abnormal  event  leads  to  cost/benefit considera-
tions.  While it may be less  expensive to merely build a  retaining wall
to  contain  raw,  undrained  sludge,  than  to obtain  maximum  strength and
stability by  dewatering (which  also involves  wall  construction), the
latter poses  much  less  threat to life and property if the wall  fails.
 In  the former case,  a wall failure due  to earthquakes would most  likely
 cause an immediate liquefaction of the  sludge and a flow  of such veloci-
 ties that would be expected to endanger life and  property if they  were in
 the flow path.   Liquefied sludges may flow as fast as water and have a
 larger momentum.  They are potentially  as dangerous as mud flows which
 have caused significant damage in the Pacific Northwest and elsewhere.
      It should be  stressed that with good engineering, abnormal events
 will have a minimal or reduced impact,  while in the absence of proper
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planning and  data,  the  impacts could be  severe.  However, it may be noted
that while  structural engineers can devise a safe foundation for just about
any site,  the costs would probably outstrip the potential benefits of such
structures  on the project involved.
     In a study of  six  sludges including lime, dual alkali and dilute
acid wet scrubbing  processes at the University of Louisville [22]   it
was found that the  silt-sized particles of sulfite sludges will settle to
30-35% solids while the sand-sized sulfate sludge particles will attain
60-65% solid  content.  When dewatered, these sludges can be reduced to
50 and 80-85%  solids content, respectively.  Researchers at Ontario Hydro
noted that  studies  by others obtained a maximum of 50% solids following
clarification  of sludge in a lagoon [44]  .
     Research at the University of Louisville [54] has verified that both
sulfite and sulfate sludges lose strength when agitated.  Sulfite sludges
will build up strength over time, but this strength will disappear upon
vibration.  Sulfate sludge is nonplastic and although it is more sensi-
tive to changes in moisture content, it will also lose strength when
agitated due to liquefaction.  Because liquefaction has the effect of re-
moving interstitial waters by packing the grains closer together, it is a
process which may be employed to increase the strength of a settling or
settled sludge.  Induction of liquefaction in the sludge by applied
vibrations followed by pumping or draining the expelled water leaves a
denser,  drier sludge mass.   Until a sludge has undergone liquefaction, it
can bo classified as potentially unstable, therefore, liquefaction has
always been regarded as a process to be feared.  Controlled liquefaction
can be a definite advantage.
     Because it is known that at an optimum moisture content compacted
soils exhibit a maximum strength, dewatering to reach that moisture
content is a useful engineering technique.  Water content can be reduced
by centrifuging, vacuum filtration and solids (normally fly ash but some-
times local soils) addition.  The material may then be trucked or pumped
to the disposal site.  Physical stability of the waste may be of great
importance to the possibility of reclaiming these sites.  The fact that
dewatering of sulfite sludges is slow while that of sulfate sludges is
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more rapid has been clarified by ongoing research at the TVA's Shawnee
Test Facility [55]   Current efforts at Shawnee have focused on the
morphology of sludge particles as affected by the type of absorbent used
in the scrubber.  They verified the difficulty in dewatering sulfite
sludges but specified that lime sulfite sludge because it entraps water
between its aggregate crystals is more difficult to dewater than lime-
stone sludges.  The results of dewatering as noted by Hagerty et al [54]
are a decrease in compressibility and an increase in structural strength
of the material.  The addition of sand has been observed to achieve these
properties.
     The grain properties of FGD sludges vary with their chemistry.
Sludges have been characterized (see Volume 3) as sulfite-rich, sulfate-
rich,  or mixed,  the latter containing significant fractions of sulfite and
sulfate.  The characterization of sludges performed at the University of
Louisville has concluded that sulfite sludges are highly compressible,
even after compaction, have low strength and are impervious to semi-
impervious.  Sulfate sludges are of low-to-medium compressibility, and
have similar permeability characteristics when compacted.  Sulfate sludges
may collapse unpredictably due to liquefaction when saturated.  In analyzing
research and studies performed by others, SCS Engineers [28]  have reported
that light compaction of dewatered sludge will result only in  a small improve-
ment of structural strength.  Another researcher  [56] has found, however, that
the dewatering  and compaction, especially of  sulfite  sludges has reduced  the
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compressibility significantly.  A mixed sulfite/sulfate/sludge with 35%
water content was subject to liquefaction after 30 days in a 30-cm
layer [22].  Studies of dewatered sludge behavior under loading have pro-
duced varying results.  SCS Engineers  [28] have reported that other re-
searchers have found that settlement is unavoidable even after heavy com-
paction, although it may be less than the settlement of most common soils
under the same circumstances.  Deposits of unstabilized sulfite sludge
filter cake might be highly compressible, even for light structures [22],
The same authors have reported that the compressibility of sulfite sludge is
within acceptable engineering limits for light to medium weight struc-
tures.  Investigations of uncompacted sludge have determined that under
low confining pressures, sludges may lose their shear strength under
dynamic loading.  Sulfate sludges not only consolidate less but undergo
consolidation much quicker than sulfite sludges.  For example, an uncom-
pacted sulfite sludge has been observed to consolidate by 10% of its
original height of 20 feet in two months, while an identical sulfate sludge
layer completed its lesser consolidation in two weeks.
      Physical blinding  has been observed between FGC  sludge and soil
layers  in contact which has  implications for  leaching at  some disposal
sites.  These sludges have insignificant effective cohesion, however,
which places an upper bound  on the  load  they  can withstand.  Field values
have  been observed  to be lower for  all physical characteristics including
permeability, maximum dry density and  compressive strength.  Pozzolanic
activity may produce a  partly cemented material which is  brittle and
friable, rather than cohesive  [57].  In an ongoing study  of waste products
from certain western coals (lignite) the fly ash was found to be highly
alkaline and has been successfully  substituted  for lime/limestone in
scrubber systems.   This system (used at Milton Young  Station in North
Dakota) produces an alkaline gypsum sludge in which pozzolanic activity
has been observed.  The physical properties of  this sludge are within
the ranges  for most lime/limestone  sludges [58].  The moisture content
of this sludge, which is approximately 30%, makes it a good candidate for
ponding.
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     Field behavior of dewatered sludges has been studied by three research
groups:  University of Louisville [22,56],  Sikes and Kolbeck [57], and
Aerospace, Inc. [37].  The former have observed that freezing of sludges
may cause dewatering or layering.  The Aerospace study [37] reported that
dumped piles of partially saturated gypsum sludge slumped when wetted by
rainfall.  In all likelihood, this precipitation destroyed capillary suction.
Properly compacted gypsum wastes would not be subject to loss of stability
upon saturation.   Such deposits will form £i impervious surface layer
 (due to pozzolanic action) which has been observed  to crack  during  freeze/
 thaw conditions.  This presents the possibility of  new opportunities  for
 leachate  formation and may imply that gypsum sludge disposal sites  be
 maintained regularly  as a function of weather  conditions.  The  latter
 group  performed a study comparing field  and lab  tests of two types  of fly-
 ash sludge deposits.  The inplace dry density  of  the two sludges  were 85%
 and 99%  of the laboratory value; inplace moisture contents were 69% and 58%
 of lab optima.  The  field compactions achieved were 85%  and  99% of  the
 theoretical  optima.   The waste which performed best in  the field had a
 finer  range  of grain  sizes,  a lower optimum moisture content and higher
 wet and  dry  densities and was chemically less  complex.
     Many of the major physical  properties  of  FGC wastes have been
 investigated to some degree.  A particular  lack of information exists
 for the  compressibility  of dewatered  fly ash wastes.  Further research is
 needed in correlation of  field  performance  with laboratory tests.  The
 conditions which will induce liquefaction require greater definition.
 4.-2.2   Public Policy and Land  Use
      The focus of  this review  centers around three aspects of FGC waste
 disposal by  impoundment:
      •  Site location,
      •  Post-closure land use,  and
      •  Impact potential of  disposal on adjacent lands.
 It should be noted that for  public policy considerations, in particular,
 issues identification is somewhat speculative based on  existing  (but
 changing) regulatory framework and projected incremental  land  require-
 ments due to projected increases in the use of  flue gas cleaning systems
 well  in the future.
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Site Location
     The site location issue may be viewed from two perspectives:  (1)
space requirements for disposal of the cumulative, increasing generation
of FGC wastes and (2) the location of a specific FGC disposal site.
     A typical 1000-MW plant will require 160 to 280 hectares (400 to 700
acres) for disposal of ash and FGD sludges over a lifetime of 30 years
depending upon the type of coal to be used and the region in which it is
located.  The 160 to 280 hectares (400 to 700 acres) include only the ex-
cavated area (dry disposal or ponding); the actual disposal area required
may be much larger since land would be required for access roads, truck
parking and unloading areas, and buffer zones to screen off the disposal
area.  It is anticipated that in the future public pressures will result
in greater attention to buffer zones in populated or recreational areas
to minimize the adverse aesthetic impacts of disposal areas.
    The area of land required for disposal of FGC wastes from a  typical
100-MW industrial boiler may be more than 10% of that required for a
1000-MW utility boiler discussed above if the FGD svstems are identical
nonrecovery units.  The height of a managed fill for an industrial boiler
is likely to be less and, hence, proportionately more area would be
required (although the volume of wastes for a 100-MW boiler will  be 10%
of that for a 1000-MW  boiler.  Cumulative vastes generated by an industrial
boiler during its lifetime will require from 16 to 26 hectares (40 to 65
acres) for the disposal area along with perhaps an additional 20 hectares
(50 acres) required for unloading areas, vehicular movement and buffer
zones.  It should be emphasized that many industrial units may employ
sodium based FGD processes and produce liquid wastes.  In many cases, the
latter may be integrated into the water and waste management plans of the
whole industrial plant (rather than treated or disposed of as FGC wastes.

     Based on the data concerning the cumulative generation of coal ash
and FGD wastes presented in Section 2, the same order of magnitude esti-
mates on land requirements for disposal are summarized in Table 4.1.
These are for illustrative purposes only and not intended as estimates on
land use.
     It appears that the following conclusions on land use are valid:
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                               Table 4.1

                      Cumulative Land Requirements
                       for Disposal of FGC Wastes
Basis:    1.  Pre National Energy Act of 1978 estimates on
              coal utilization.

          2.  All FGC wastes disposed on land as moist
              material in lifts of 10 meters (32.8 feet).

          3.  Only excavated disposal area mentioned.
              Actual land required including buffer zones
              and access roads may be 2 to 3 times the
              listed amount.
No.

 1.

 2.

 3.
Coal Ash Alone

FGD Waste Alone

Total FGC Wastes
  By 1985
Sq km   (Acres)

 39.6   (9750)

 16.2   (4000)

 55.8   (13,750)
  By 2000
Sq km  (Acres)

 130   (32,100)

  65   (16,050)

 195   (48,150)
Source:  Arthur D. Little, Inc.
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     •  From a regional or state land use perspective, these land require-
        ments are not large.
     •  Federal Regions 5, A, 6, and 3 (in that order) are projected to
        require maximum total land and maximum incremental land.  While
        individual disposals would result in a loss of land for other
        purposes, the impact when considered on a regional or national
        scale is not very large.
     •  Much of the land area required for disposal between 1985 and 2000
        would result from the establishment of new utility plants and in-
        dustrial boilers.   It is anticipated that these "energy centers"
        will require a larger land area  than previous facilities and hence
        be sited in relatively  rural areas.  Political and economic fac-
        tors are expected to increase land use planning for such uses and
        place additional regulatory constraints on utilities and industry.
        Potentially, demand could arise  to combine utility plant and dis-
        posal area into one site, reducing requirements for off-site dis-
        posal.
While land requirements for FGC waste disposal are not large on the
national or regional scale, at  the local level land use could become an
issue on a site-specific basis.  FGC waste disposal areas are usually
zoned for industrial use.  This land use may not be compatible with other
uses such as residential, commercial, and recreational.
     One of the largest operating FGC waste systems utilizes a 560-hectare
(1400-acre) impoundment for the disposal of treated sludges from a two
unit 1650-MW power plant.  While a third unit is under construction, the
impoundment was designed for 30-year use, assuming a filled depth of 400
feet of waste [59].   This example may be exceptional because of the large
operation size combined with impoundment disposal planned for one site.
Future location problems for such large impoundments could exist, although
they are expected to be location specific.  A "hazardous" or "non-hazardous"
designation for FGC wastes would not alter land requirements for disposal
but could potentially increase location-specific problems with siting.
     The aesthetics of a disposal operation can have an effect on site
location due to local public reaction.   Such problems, where they occur
are not  expected  to  be significantly different from location problems for
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other types of waste disposal areas.   If  anything,  they may  be less  because
of the uniform appearance and relative absence of odor with  FGC wastes.
Post-Closure Land Use of Impoundments
     Considering the amounts of land area that could be required for FGC
waste disposal on a site-specific basis,  the issue of post-closure land
use is an important one.  Constraints on post-closure land use are related
to the site, type of waste, method of disposal and climate.   Many of the
specific issues in question concern waste characterization and its relation-
ship to long-term disposal physical stability and chemical stability.
Research in these areas is discussed in greater detail under each of those
headings, with  the issues addressed here only as they relate  to disposal
site post-closure land uses.
      For wet impoundments that are drained following disposal operations,
 the major issues are those discussed below for dry impoundments.  Where
 water cover is intended to be left over the disposal impoundment, several
 additional issues exist:
      •  The water quality of the supernatant water,
      •  The impact potential of the supernatant water on terrestrial and
         aquatic species, and
      •  The impact potential of released water on downstream users.
 4.2.3  Wet Ponding
      Some of the generic environmental issues pertaining to  any method of
 FGC waste disposal on land were discussed above.   In  this  subsection,  the
 focus will be  on wet ponding.
 Physical Stability Issues
      The issues concern  liquefaction  and other  abnormal events.  There
 are several aspects to  this issue:                     :
      •  Development of  appropriate  engineering  basis  for the particular
         waste  involved,
      •  Design safety  factors  to  be adequate  for  the  specific site taking
         into account the potential  impact of  abnormal events, and
      •  Adequate monitoring of the  site including embankments, dikes  or
         dams.
      Physical  stability impact issues can in principle be  minimized with
  proper  engineering design and operation.

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 Water  Quality  Considerations
     Many,  if  not  all,  FGC waste  disposal water-related impacts arise
 from the  migration of leachate  and/or  runoff.   Consequently, labora-
 tory tests  of  leaching  characteristics of FGC wastes are of general
 relevance to all land-based disposal options.   Impoundment of FGC
 wastes with water  cover can present a  significant potential for
 related impacts because the head  of water promotes percolation of
 water  through  the  wastes and would  (theoretically) eventually cause
 the water table to rise to pond level,  maintaining an intimate contact
 between waste  and  groundwater.  This process can be avoided by:
     • Wet stabilization process, wherein  the  settled wastes undergo
        pozzolanic reaction to  produce a layer  of very low permeability.
        The Dravo  wet process is  an example.
     • The use of an impermeable liner under the pond to contain the
        leachate.   Liners are not fully proven  at present; research
        efforts now underway should produce useful data on their applic-
        ability in the  immediate  future.  For practical purposes, contain-
        ment may be considered  effective if the leakage is adequately
        delayed and/or  maintained at a low  rate.  Thus, the effectiveness
        of  liners  and their rates of deterioration in contact with FGC
        wastes in  various environmental settings is an important considera-
        tion in assessment of environmental impact of FGC waste disposal
        in  impoundments  with a  maintained water cover.
     Of primary importance to water impacts is  the rate of pollutant mass
 release (mass/time)  to  the surrounding  ambient water via leachate.  This
 quantity may be estimated by the  product of leachate quality (mass/pore
water volume) and waste  permeability/length/time by disposal area.  The
 actual pollutant release rate cannot exceed this amount, although in dry
seasons the actual  rate  of leachate generation may be far less than in-
dicated by the product of permeability and area.  Setting aside the very
important site-specific  considerations such as leaching solution charac-
teristics (water quantity, quality,  and flow pattern), surrounding soil
permeability,  and disposal site area,  an intrinsic waste property of
particular significance  to water contamination is pollutant flux (mass/
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area/time)  which is the product of each pollutant's  equilibrium leachate
concentration and the permeability of the waste.   This waste property
could be established by standardized leaching and permeability tests.
At this time, the development of standard leaching tests continues.   No
procedure has been generally recognized, nor have general interpretive
rules been established to relate these intrinsic leaching properties of
wastes to field environments.  Nonetheless, comparisons of intrinsic
pollutant flux for various FGC wastes have been reported indicating that
the intrinsic flux from chemically stabilized FGC wastes would be one or
two orders of magnitude less than from unstabilized FGC wastes.  However,
precise estimates on the total impact of chemical stabilization should
include:
     •  Impact of surface runoff, and
     •  Impact of permeation on a site-specific basis.
     A number of R&D programs on leachates have produced data  on leaching
behavior as  described in detail in Volume  3.
     Once a  waste is placed in any type of land disposal site,  its  initial
contact with water would tend to flush out interstitial waste  liquors:
initial leachate quality could be similar  to  that of  the occluded liquor.
The initial  volume of water within the waste  is equal to the pore volume
 (porosity times  the  total volume of waste).   After  several  pore volumes
of water have passed  through the waste  deposit  (PVD = pore  volume displace-
ments), most of  the  occluded water will have  been flushed and  the leachate
 concentration of major  ions  is  expected to approach steady  state corres-
ponding to the  solubility of the  major  constituents in the  solid phases
 of  the waste.   These solubilities  are often pH  and  temperature dependent,
 and thus  the long  term leachate  quality will also depend on pH and  tem-
 perature.  In  theorv,  trace  metals  also approach  an equilibrium value.
 However, Rossoff, et  al.[37]  investigated nine trace metals  and could find
 no  evidence  that solubilities  of metallic compounds (oxides, hydroxides)
 controlled the  equilibrium concentration.
      Leo and Rossoff  [60] have  investigated the first  flush effect for five
 specific disposal scenarios and find that the first flush of occluded
 waste liquors  may affect leachate quality for as little as ten years
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(for ponding) or as long as 1300 years for a managed landfill of stabi-
lized sludge.  Water quality impacts of ponding are consequently likely
to be controlled by the long term equilibrium mass release rate of pollu-
tants and the nature of receiving waters on a site-specific basis.  The
long term mass release rate of pollutants is controlled by equilibrium
leachate quality and the rate of leachate and runoff generation.  The
rates of leachate and runoff generation are affected by many variables
including meteorology, hydrology, site management, and waste permeability.
Laboratory Tests of FGC Waste Leachates
     Laboratory tests of leachate quality are indicative of relative
differences between wastes but are less than fully relevant to assessment
of disposal impacts because certain environmental conditions cannot be
reproduced in the lab.  Further discussion of FGC waste leachate quality
may be found in Volume 3.
     It was reported [37,60] that equilibrium (40-50 PVD's) leachate con-
centrations were not significantly dependent on pH.  TDS and sulfate
levels tended to similar values of approximately 2000 ppm and 1200 ppm,
respectively, regardless of waste type.  It was indicated that these con-
centrations are probably controlled by the solubility of the CaSO, component
of the sludge.  The only exception was a sulfite-rich sludge whose equilib-
rium TDS and S0~  concentrations were much lower than the others, indicat-
ing that CaSO, solubility was not dominant for this sludge.  These leaching
tests were conducted under aerobic conditions, while field conditions for
leaching of sulfite-rich sludge are more likely to be anaerobic  (although
oxidation of the sulfite also probably occurs in the field).  Thus, it is
reasonable to expect that under field conditions, sulfite-rich FGC wastes
even those containing greater than 5% CaSO,, will yield leachate whose
equilibrium TDS and SO, concentrations will be significantly less than in-
dicated by CaSO, solubility.  However, the leachate concentrations of
major species in mixed and sulfate-rich sludges are expected to be con-
trolled by CaSO, solubility.
     Sulfite-rich sludges in anaerobic conditions are expected to generate
leachate having a high chemical oxygen demand (COD) present as total oxi-
dizable sulfur (TOS).  Without relevant field testing and experience, it
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is difficult to assess the importance  of  this  TOS  content  to  water quality.
Groundwater in the saturated (water table)  zone is deoxygenated by micro-
bial activity.  When drawn to the surface in wells, it is  well aerated
during the pumping or sampling process.   Only  where surface water bodies
receive leachate or runoff-related flows  is the oxygen demand expected to
pose any potential environmental problem, and  the  extent of this problem
would be extremely site-specific.
     The results of leaching tests conducted to date tend to  indicate that
the degree of oxidation of the waste can lead  to significant  differences
in leachate quality, with sulfite-rich sludges expected to yield leachate
with lower TDS and SO^ concentrations, but with a greater COD  (Lunt, et al.)
     As reported in  Volume  3,  there is some evidence to suggest that
sludges containing  fly ash  yield leachate  containing significantly higher
levels of some trace metals  (e.g., arsenic) than ash-free sludge  (Radian,
Rossoff ,et al. , Final Report  68-02-1010).   However, Leo and Rossoff [61]  con-
clude  that  the differences in leachate quality are not  dramatic  and  that
flyash removal upstream of the scrubber will not  significantly improve
the trace element  leachate quality in relation to  the pollutant  hazard.
Unfortunately, so  few  tests  have been conducted with ash-free FGC wastes
that this question is  not clearly  resolved.
     Equilibrium leachate concentrations of major constituents show no
dependence  on scrubber absorbent  (lime,  limestone,  double alkali) but
trace  element leachate quality  is  observed to  depend on absorbent and
type of  coal  [62].
     The  quality of leachate depends  not only  on  the type of waste,  but
also on  the nature of the leaching solution.   Leaching  may occur in
several  ways, including surface leaching of impermeable materials, with
subsequent  runoff which may eventually enter  surface or groundwater; by
 rainwater percolating downward through permeable  wastes;  or  by groundwater
 flowing horizontally through the waste mass.   Rainwater,  the leaching
 solution in the first case, will be well aerated, and of variable pH (4-7)
 in the U.S.  (more acidic in the NE, more basic in the west and south).
 Percolating rainwater and groundwater quality will change as it interacts
 with the waste, and is likely to be reduced in dissolved oxygen by mixed
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and sulfite-rich sludges.  Most FGC wastes are neutral or alkaline and
thus  the  leaching solution, even if initially acidic, will tend to become
more  basic.
      Preliminary results  from column leaching tests at WES [62] indicate
no significant variations of leachate quality with pH of leaching solution.
These results are corraborated by the study of Duvel, Rappand  Atwood  [63]
comparing leachate: quality for two different leaching solutions:  dis-
tilled water and a synthetic solution analogous to acid mine drainage.
Certain trace metals were leached only slightly more effectively at low
pH, but a precipitate of  iron sulfide was formed.  Leo and Rossoff  [61]
found that the trace metals  Pb and Zn  are leached more readily by acid
leachate  while only Pb, of the trace metals analyzed, showed a' significant
difference in aerobic/anaerobic comparisons (higher for anaerobic).  Data
on leaching from stabilized FGC wastes is not fully conclusive data although
reduction in trace elements is reported  [60].
      Besides leachate quality, FGC waste permeability is an important
disposal  parameter amenable to laboratory testing.  However, as discussed
in  Volume 3,  laboratory  tests of permeability may not be relevant to
permeability in the field.  Sample disturbance; passage of water around,
rather than through, the  sample; and stratification of field deposits are
common causes of unrepresentative laboratory results, while weathering,
particularly freeze/thaw  cycles, are expected to change in situ permeabili-
ties  over time.
      Unstabilized sludges consistently exhibit permeabilities of 10   to
  -4
10    cm/sec while stabilized sludges show permeabilities one to two orders
of magnitude lower.   Sulfite-rich FGC wastes are generally less permeable
than  sulfate-rich ones because of their "flat" crystalline morphology.
Addition  of fly ash,  fly ash and lime,  fly ash and cement,  or the proprietary
additive  Calcilox will reduce permeabilities by about an order of magni-
tude  although the reported effectiveness of treatment in permeability
reduction  is quite variable [37,60,64].
      To close this discussion of laboratory tests pertinent to wet impound-
ments  and  all other land-based disposal options, soil attenuation of
leachate  constituents must be considered.  Because of the great variety
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of soils and wastes,  this  again will  be  a highly,  site-specific  considera-
tion, but laboratory  results  should provide some guidance on the question
of whether the soils  surrounding  a disposal site will be capable of retain-
ing potentially problematic ions  associated with leachate.   Two  studies
that may offer guidance in this regard are:
     •  Radian study for EPRI [40].   This  study  entailed not  only
        laboratory measurements of leachate/soil interactions,  but also
        the development of an analytical model which permits scale-up of
        their laboratory results  to facilitate field-scale estimates of
        soil retention.  Anionic  forms were not retained by the bulk of
        solids.  Radian tests involved synthetic mixtures of soils (with-
        out organics) and field samples.   Since trace element levels were
        low, Radian increased concentration to study effects.
     •  U.S. Army Materiel Command, Dugway Proving Ground is also  perform-
        ing soil attenuation studies, the  results of which  had not been
        published as of early 1979.  However, preliminary results  are
        broadly consistent with the Radian findings.
Field-Scale Research
     Pilot scale tests of pond disposal  of FGC wastes have  been undertaken
at  TVA's  Shawnee facility and by Louisville Gas  & Electric  Co.  (Paddy's
Run) while  full scale pond disposal is being  monitored  for  potential well
contamination at the Bruce Mansfield  disposal reservoir by  Pennsylvania
Power  & Light.  Preliminary  results  at  Shawnee  and  Bruce Mansfield indi-
cate no significant  contamination of  groundwater to date [60,65].   How-
ever,  these results  may not  be significant because  the  disposal ponds
have been in operation for less  than five years and there is no reason to
expect that pollutants would have migrated from the site via groundwater
                              •
 in such a short time.   This  points out a fundamental problem in ground-
water protection:   field  verification and experience is gained very slowly.
 Laboratory analyses  of supernatant,  leachate, and permeability of samples
 from field disposal sites provide valuable information relevant to actual
 disposal conditions:
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     •   It  was reported  that  compaction at  the bottom of these relatively
        shallow ponds can reduce the waste permeability by a factor of
        2 to 5.  Aerospace [61]  concluded that compaction at the bottom
        of a 12 meter deep pile of FGC waste will decrease permeability
        by one order of magnitude.
     •  Aerospace studies [50,61]  note that at Shawnee,after allowing for
        weather, leachate concentration of the major solubles dropped to
        one-half to one-third of input liquor.
     Aerospace Corporation, at TVA's Shawnee facility,  is investigating
an underdrained pond system in which leachate is collected for treatment
or reuse.  One potential advantage of this system for water-related impacts
is the reduction in head which accompanies drainage, thus reducing per-
colation into the region below the site.  In areas with appreciable rain-
fall, underdraining requires [39]  dividing the disposal area into several
sections (over the life of the plant) using one section at a time from
the surrounding water bodies.   Reduction in the amount of leachate
generated may be accomplished for ponding scenarios by diverting the entry
of surface runoff from adjacent areas.  The high water content and fluidity
of impounded FGC wastes make site management to promote runoff and eliminate
standing water difficult or impossible to achieve.
     Waterways Experiment Station of the U.S. Army Corps of Engineers has
been conducting field studies on the effects of FGC waste disposal on
adjacent soils and grounwaters.  While final results are likely in 1979
it is noted that earlier WES reports on three FGC waste disposal sites
[66] have been reported.   These sites had been utilized for FGC waste
disposal for five to nine years.  Well samples were analyzed for major
soluble components of sludge and several trace metals.   Soils were ex-
tracted and analyzed to determine if adsorption on soils was occurring
that might attenuate leachate migration.  Distinct leachate plumes were
not resolved and migration patterns were reported to be complex.  However
careful statistical tests reportedly revealed that groundwater at all
three sites exhibited increased contaminant  concentrations as a result of
the disposal operation and that there was little or no evidence of attenua-
tion of some pollutants by the soil [66].
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     Aerospace [61]  has performed an analysis of the potential for ground-
water pollution in terms of the flux of IDS to subsoil over a 150 year
period.  They considered five disposal scenarios including impoundment of
stabilized and unstabilized FGC wastes, both with and without diversion of
runoff, and managed landfill of stabilized waste.  The analysis incorpor-
ates certain site-specific aspects by specifying that the natural ground-
water recharge rate is 10 in/year and the depth of waste is 30 feet.
Their analysis is not generally applicable to all disposal environments.
According to that analysis, diversion of runoff from an impoundment such
that it is not covered by water, is more effective than chemical stabiliza-
tion in reducing the potential for prevention of groundwater contamination.
A well managed landfill of stabilized sludge, including grading to promote
runoff, presents the lowest potential for groundwater contamination
according to their report.  However, the promotion of runoff is not always
consistent with the protection of surface water quality on a site-specific
basis.
    Site management over indefinite periods of time may  thus be a major
requirement  for pond disposal due to the potential  for  impact without
strict management.  However, Aerospace [61]  also  concluded  that  the under-
drain  system with collection, and treatment  or  reuse of leachate would  re-
sult in improved physical  stability such that long  term site  management is
a much less  serious problem.  Furthermore, liners would  not be  required  to
protect groundwater.   The  ideas  expressed  in that report  [61]  are  being
 field  tested at  the pilot  scale at  TVA's  Shawnee plant  at this  time.
 Other  Potential  Impact Considerations
      In addition to the land use and water quality  issues discussed above
 for wet impoundments  of FGC waste,  two other types  of potential impact
 issues were  identified in Section 2.   These are air quality related and
 biological issues.   The former are considered of little or no environmental
 significance for FGC  waste disposal in wet impoundments, and have not been
 the subject  of empirical environmental assessment studies.  Biological issues
 such as revegetation  requirements,  could be of  significance,  but also have
 not been  studied empirically for wet FGC waste impoundments.  This point is
 discussed in the summary of data gaps and research needs (Section 4).
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4.2.4  Dry Disposal
     Four types of FGC waste may be disposed of in dry form:
     •  First, bottom and fly ash which have been collected pneumatically
        often these two material flows are combined for disposal but this
        is not always the case.
     •  The second group includes gypsum sludges from conventional FGD
        systems on low sulfur coal or forced oxidation FGD systems.
     •  The third group is the stabilized sludges.  Both sulfite and sul-
        fate sludges are stabilized by chemical treatment and although
        dewatering is often a preliminary step to stabilization, it is not
        a stabilization process by itself.  Stabilized sludges are often
        placed in the disposal site while still containing as much as 30%
        moisture.  This water is, however, chemically bound and plays an
        important role in the curing process which renders stabilized
        wastes into much harder aggregates.
     •  The last dry wastes are those generated by dry aorbent desulfuri-
        zation techniques.  These techniques are currently receiving a
        high level of attention and commercial systems should be operative
        in the early 1980's.  Unfortunately there exists a large data gap
        about the materials produced by these processes and this is a
        very important area to be focused upon as a result.
Physical Stability Issues
     The generalized discussion in Section 4.2 also applies here.  In
addition, because so many of the inherent problems of FGC waste have
been ameliorated by stabilization or disposal without water, the physical
stability impacts associated with this option are virtually negligible
when good disposal design and practice are followed.  Normal field con-
ditions do have the potential to interfere with the proper resolution
of stabilization processes and to inundate  the dry wastes.  Thus, the
engineering focus shifts from construction (as it was for ponding) to
operations, to ensure the attainment of the increased stability of dry
and treated wastes.  Due to the high strength of many of these wastes,
the final use potential of the site is relatively broad, and it can
become an economic incentive that field conditions do not interfere with
material strength.

                                 4-20

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     From this perspective,  abnormal  events  are  cast  differently  as well.
They are any event which,  within the  scope of available  planning  and
engineering technique,  the disposal site manager cannot  accommodate.   For
instance, during a tremendous storm,  the disposal site is flooded and the
available pumps cannot  drain it fast  enough  to prevent seepage into and possibly
saturation of the top layer(s) of the landfill.   Other such occurrences
include shortages of crucial supplies and other  unusual weather problems.
     Poor engineering would be defined in this case then by a lack of
attention paid to field operating conditions and procedures.  Such events
as uncontrolled rainwater runoff entering the freshly placed wastes,
wastes placed before curing or left in a position where curing is inhibited,
development of thick lifts and improper compaction may all contribute to
a reduction of the physical stability of the completed disposal  area.
     The Waterways Experiment Station  [67] reported  on testing of five
sludges  of varying sulfur content, origin and scrubber type.  Fixation
generally resulted in a consolidated material of  increased  density,  de-
creased  porosity  and decreased permeability with  some degree  of  structural
strength.  These  results held true for  processes  producing  a  concrete-like
material.  Soil-like sludges produced from  stabilization processes,  were
more porous than concrete-like sludges and raw sludges exhibiting increased
permeability  and  decreased  strength.  Material  properties are highly
dependent on  the  stabilization process  and  were consistent  for each  process.
Fixation was  observed  to  have a  greater effect  on stabilizing double alkali
sludges  than  limestone sludges.
     The work at WES was  reported on more recently by Bartos  and Palermo
 [68].   The  research indicated that fixation (stabilization) generally re-
duces  sludge  plasticity although the plasticity level of sludges is  already
 quite  low.   The compressive strength is highly  dependent on the process
 and sludge  type; the strengths are typically approximate to those of
 soil-cement mixtures or low-strength concrete.   Several of the processes
 produced materials comparable to low-strength concrete; one material, a
 stabilized western coal/limestone sludge had a compressive strength in
                    2
 excess of 280 kg/cm .   The bearing capacity of soil-like stabilized sludges
 is comparable to low strength concrete and soil-cement  type  sludges should
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be adequate for most landfill applications.  WES also found that durability
is related to the stabilization process.  Aerospace assessed ponding and
landfill concepts for FGD wastes [60] and concluded that some control for
runoff, seepage and direct discharge of water may be required.
     Investigations by Thacker [56] involved the addition of fly ash to
sulfite sludges.  It was found that compression under load was reduced
but not enough to allow the sludge to meet engineering criteria for lead
bearing foundations.  No time-dependent bonds were developed in fly ash-
sulfite sludge.  The addition of fly ash to the sulfite sludge did not
produce an increase in the shear strength but did lower the strain causing
shear failure.  The compression of this sludge-flv ash mixture was within
the range encountered in natural soils.
     At the Columbus and Southern Ohio Electric Conesville Station, a
thiosorbic lime FGD system produces a 30% solid mixed sludge.  This sludge
is stabilized by an IUCS process.   This sludge was compacted to ig/cc
          o
(65 Ibs/ft ) dry density in 60-cm (24-inch) layers.  Tests found that the
                                  2           2
material can bear more than 5kg/cm  (5 tons/ft ).  The structural capabil-
ity of this material may be better than for most fills.  Investigators at
Aerospace [60] have found that chemically stabilized sludges may attain
a high load bearing strength.

     The physical stability of chemically  treated  FGD  sludges can be
evaluated by knowledge of the material's compressibility, shear strength,
density, bearing capacity, consolidation characteristics and  durability.
While each stabilized sludge will behave uniquely, the general charac-
teristics of soil-like and concrete-like sludges outlined above present a
comprehensive data base.  Further research is needed to verify these re-
sults and increase the amount of available information.  An important
issue which has not been investigated is the compressibility, consolida-
tion and bearing capacity of FGC sludges in combination with  other wastes
in a sanitary landfill.  The chemical reactions which might occur by the
placement of such diverse wastes in contact could possibly have an effect
on morphological and thus physical characteristics of  the fill as a whole.
     While some field investigations on FGD sludge durability have been
performed, no attempt has been made to correlate and explain  the varia-
tion between in-field physical test results for stability and laboratory
analysis.                           4-22

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     Physical blinding has  been observed  between  FGC waste  and  soil  layers
in contact [22]  which has implications  for  leaching at  such disposal sites.
Small particles  of sludge fill the interstices  between  larger particles  of
natural soil, thus,  lowering the permeability of  the natural soil.   These
sludges reportedly have insignificant effective  cohesion,  which  places an
upper bound on the load they can withstand.  Field values have  been  observed
to be lower for  several physical characteristics  including  permeability,
maximum dry density and compressive strength.
Land Reclamation Issues
     The major issues surrounding land reclamation of  dry impoundments
include:
     •  Revegetation potential,
     •  Toxicity potential of sludge substrate, and
     •  Suitability of disposal area for post-closure uses based
        on physical stability in varying climate regions.
     When the land disposal options are selected, consideration of
restoration must address the terrestial plant cover.  In the arid and semi-
arid portions of this country, plants are  very sensitive and require care
in  selection and replanting; for  instance  sage brush pods must be processed
through the  digestive system of an animal  or synthetically  stressed to
insure proper seed germination.   Also, often the overburden topsoil is very
thin  (3-6 inches) and must  be carefully  segregated for future  use in
restoring the disposal site.
      Revegetation of  ponded areas can be used  to prevent erosion of dried
                •
fine  material and as  a step toward reclamation of the  area  to  other uses.
TVA has  initiated  field  testing  of dewatered sludge pond revegetation.
Legumes,  grasses  and  forest tree species are being examined.   Survival
and growth  rates  are not presently available but preliminary results
have  indicated  that:   (1)  the sulfite  and  boron  content  of certain
 limestone sludges are potentially toxic  to some  plant  species  (boron
 uptake has  been observed);  and (2)  soil  amendment with plant nutrients
 such as nitrogen and phosphorus may be required  to  sustain growth.
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     The physical stability of the disposal site would dictate the range
of post-closure uses.  As indicated by laboratory test results, treatment
of sludge material significantly alters the bearing strength of disposed
FGC waste material.  Untreated FGC wastes, especially those high in
sulfites, can tend to liquefy.  This characteristic has caused some to
report that the use of even lightweight machinery could be difficult.
However, experience with test ponds by TVA has indicated that once ponds
are sufficiently dewatered, lightweight equipment can be utilized [69].
     Based on laboratory work, Klym and Dodd [70] report that for
impoundments of untreated FGC waste, two to three feet of fill would
be needed over the waste to provide a working surface, and at least an
additional five feet of fill for surcharging the sludge to obtain a
stable landfill [70].
                                   4-24

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     However, reasonable post-closure land use decisions  are difficult
without better definition of the behavior of large amounts  of FGC waste
material through field verification.
     Restrictions on post-closure land use based on physical stability
need to be examined.  While it appears that re-use of impounded stabilized
FGC materials may be restricted to parks or other uses where low loadings
or tolerance of settlement can be accomplished [71,72], greater under-
standing of loading capacity of large volumes  (depths) of stabilized FGC
materials would be useful.  In other words, correlations between FGC
materials and other substrates (e.g., natural soils) would provide a better
understanding of land reuse possibilities.
     The effects of climatic conditions on dry disposal  sites  also requires
field  verification.  Long term measurements of chemical  or  morphological
changes as a result of  freeze/thaw action have not been  made [72],   Simi-
larly,  field testing of  the effects  of  inundation and drying on large
volumes of FGC wastes  (as in an  impoundment)  need to be  made.   While fill
or  cover of  an  impoundment with  relatively  impervious material has been
recommended  to  minimize contaminant  leaching,  the potential effects  of this
approach on  physical  stability may need to  be identified.   In summary,
correlations between  lab tests  and field  behavior of soils have been  de-
developed, but  such correlations do  not presently exist  for FGC wastes
 [71, 72].
      Revegetation potential and especially the potential for contamina-
 tion of food-chain vegetation has yet to be investigated  for the broad
 range of  FGC wastes.   The amount of  soil amendment and/or depth of fill
 required  to  establish vegetation, the potential for upward migration of
 major species and trace contaminants such as heavy metals and the incor-
 poration of these contaminants by a wide variety of species also have yet
 to be investigated.  Soil-waste interactions in terms of water and nutrient
 holding capacity could be far better understood, as well as the effects of
 deep root systems on cracking and permeability of  large-volume FGC waste
 impoundments.
      Limitations on post-closure uses  of landfilled  FGC wastes  of varying
 characterizations have  not been thoroughly investigated.   In  addition to
 physical stability issues described above, safe  fill heights  have yet to
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be established.  While design charts have been published for maximum safe
fill heights for certain soil types, such information has not been estab-
lished for various FGC wastes[71].   Triaxial compression tests on consoli-
dated samples, with measurement of pore water pressures would help to
establish maximum safe fill height in relation to slope angle and waste
shearing behavior[71].   While disposal site engineering and/or post-
closure practices can likely be tailored to the bearing capacity of the
wastes, the basis for these practices has yet to be fully established.
Water Quality Issues
     Permeation and runoff of leachate from dry disposal is a significant
issue.  Discussions on permeability, leachate quality and intrinsic pollu-
tant flux found above are also relevant to dry disposal.  The dry disposal
methods may have a lesser level of water quality impacts for several
reasons:
     •  Several site management practices are feasible for dry disposal
        operations which are infeasible or more difficult for wet impound-
        ments.  These include grading to promote runoff, and isolation of
        the wastes with respect to the surrounding waters[36,61,65].
     •  The relative absence of free moisture initially would be expected
        to alter and probably reduce any first flush effect associated
        with the leaching of occluded waste liquor.
     •  Untreated sulfite-rich FGC wastes which pose a potential water
        related impact associated with the high COD of leachate generated
        under anaerobic conditions, cannot easily be dewatered to the
        point where dry handling is feasible.  This makes the disposal
        option less likely for a waste type of high impact potential.
     Of these considerations, the first is probably the most significant
and has been discussed by Leo and Rossoff [61].  They concluded that grading
to promote runoff and eliminate standing water, coupled with diversion of
runoff from adjacent areas, would reduce contaminant loading from FGC
waste to groundwater by an order of magnitude—compared to the reported
benefits of chemical treatment.
     Some field-scale evaluations of water quality impacts are in progress
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as presented (Table 2.14).   To  date,  no  substantive results
pertaining to water-related impacts  associated with dry disposal methods
are available from these disposal studies.   As was noted above,  for pond
disposal, it is unusual for field evaluation of groundwater impacts to
provide substantive results within periods  of less than five years be-
cause contaminant migration through wastes  and soils tends to occur very
slowly.
Other Considerations
     With very few exceptions,  the potential air quality related and
biological impact issues associated with dry FGC waste disposal have re-
ceived very little attention in the form of empirical research.
     FGC waste landfills or dry impoundments, if designed to remain un-
covered by other overburden upon closure, could be sources of some fugi-
tive particulate emissions after disposal operations ceased.   (During and
shortly after disposal, even the driest FGC wastes have more  than the
5  to 10% moisture content required to resist wind  erosion.)   This issue
does not appear to be addressed by previous, ongoing or planned research,
but its potential overall significance does not appear  to be  large relative
to other issues.
     Mechanisms of potential biological impact are discussed  in Section
2  above.  Of these that apply  to dry disposal, none appear  to have
been studied in the past and one is  currently  under study.   The present
study  concerns the revegetation potential  of  dewatered  FGC  waste ponds.
It is  being performed  by TVA,  the Aerospace  Corporation,  and others  as
part of  the EPA-sponsored  Shawnee Field Evaluation program.   Only early
results  of  this work are available.  These are discussed  in Section
4.2.2.2   above.

4.2.5  Mine Disposal
     FGC waste disposal at mine sites  can  potentially  take three forms:
 subterranean placement, burial in enclosed lifts  and  bulldozing into
 embankments.   Each method  is  unique and engineering criteria vary
 accordingly.
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Physical Stability Issues
     Underground disposal requires a pumpable material for methods
designed to date.  Fly ash, bottom ash and raw FGC wastes may all be
disposed in this fashion.  Because the disposal scenario involves waste
containment by bulkheads, the strength and anchorage of the bulkheads
is an important engineering issue.  Analysis of geologic strata as they
affect secure bulkhead placement and leakage to aquifers plays a part
in good engineering.  Under normal conditions, the security of the waste
is not threatened.  If it is entirely contained, with drainage and treat-
ment of drawn-off wastewaters performed, impacts of stability and also
groundwater may be of little importance.  Final land use is practically
an unrelated matter and may conflict only with the pump station above
ground.  Abnormal events are those which would interrupt the geological
integrity of the site.  This presents more problems for groundwater con-
tamination than in causing stability problems.  While an earthquake shock
may fracture an FGC waste containment structure and the now liquefied
waste would flow through the mine, unless the mine were active, no loss
of life and property would ensue.  A possible result of such a failure
is surface subsidence caused by the sudden release of strains built up
over time around the sludge-filled cavities.  This possibility is
regarded as highly unlikely by some researchers [117].
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     General considerations discussed in Section 4.2.2.1 also apply here.
In addition, the stability issues  of surface mine pit  disposal are the same
as those for the dry disposal.   Additional information will be required to
correlate results of field studies with the results  of lab  and model tests.
An unresolved issue regards the effect on stability  of acid mine drainage
in contact with FGC wastes.  To date, this has been  investigated only
with respect to leachate formation.  Also along this line is the stability
of various combinations of fill materials in the spoil pit:  FGC sludge,
mine  tailings, overburden, etc.,which has not been studied in the lab or
in the field.  Because so much of the behavior of FGC waste can be attri-
buted to the nature of the disposal site and operations, site-specific
field studies are a necessity.
     From an engineering standpoint, only materials which can be bull-
dozed and will remain on slopes without cracking or slumping are suitable
for embankment disposal options.  Thus far the only FGC wastes which may
be so applied are those which have been stabilized or  rich  in  sulfates.
Abnormal events will be those which disturb  the  integrity of either the
compacted waste or  the underlying soil layers.   In this case,  events  such
as earthquakes, flooding and slumping due  to saturation of  subsurface
layers from land rainfall  are  included.
     At  the  Duquesne Light Company  in Pennsylvania, disposal  of  a  5-10%
solids fly ash slurry in an abandoned coal mine  is taking place  [411.  The
slurry is pumped through  a 50  cm  borehole  to the mine itself;  the  system
includes  three  pump holes  to  dewater  the  filled areas.  Concrete block
dams were constructed  to  contain  the  material  in the  mine.   No reports of
the physical stability of the sludge  of  the sludge  or of  the system were
made.
      Surface mine  disposal methods require at least dewatering and
preferably  the stabilization  of FGC waste to avoid  leachate formation and
 to permit reclamation to proceed upon a stable surface.  Disposal will
 occur in layers and involve  compaction techniques.    The materials must
 be plastic enough for contouring by bulldozers.  Curing must occur only
 after placement, therefore the timing of reclamation/stabilization activi-
 ties must be carefully managed.  Methods which result in level surfaces
 include disposal such as is being performed at Minnkota Power's Milton R.
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Young Station in North Dakota, and mine pit disposal in horizontal
layers.
     The normal impacts of surface mine disposal options are strongly
influenced by the requirements of the Surface Mine Control and Reclamation
Act.  Because these requirements will set lower limits on the bearing
capacity of the land, determine water tables and surface runoff, the causes
of instability are greatly reduced.  Therefore, under normal circumstances
in which these requirements are observed, stability would be assured.
Abnormal events, however, are similar to those that would also
affect dry disposal sites—a disruption of proper operations.
     Erosion is a potentially serious question for graded disposal sites.
Cured soil-like stabilized wastes would be as prone to erosion as a
natural soil.  A well planned disposal operation must therefore include
anti-erosion techniques such as runoff control and vegetation.   Subsur-
face information will play a role in determining good field operations.
Knowledge of the material itself is critical for this disposal option.
Abnormal  events could disturb the integrity of the compacted waste and
 the underlying soil layers,  or  both.

     Based on unconfined compressive tests  [68], the performance of soil-
like fixed sludges appears likely to be satisfactory in bearing capacity for
embankment construction.  While existing research has identified several types
of treated materials suitable for use in embankments, a thorough survey
of this application for sludges has not been made.  The use of fly ash
embankments has been studied extensively and put into actual use by the
FHA.  This is not true for FGD waste studies and more specific research
on shear strength and consolidation characteristics of stabilized sludges
in actual embankments should be performed.

     Surface mine disposal methods require at least dewatering and some-
times the stabilization of FGC waste to avoid leachate formation and to
permit reclamation to proceed upon a stable surface.  Disposal can be
expected to occur in layers and involve compaction techniques.   The waste
materials must be plastic enough for contouring by bulldozers.   Curing
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must occur only after placement,  therefore the timing of reclamation/
stabilization activities must be  carefully managed.
     No studies of FGC waste disposal on surface mines have been completed.
Two surface mines with on-site generating stations were disposing of FGC
wastes in mine pits in late 1978.  At Minnkota Power's Milton R. Young Station
in North Dakota, filling of a "v-notch" with FGC waste is being conducted
under an EPA-sponsored program.  Physical stability and groundwater
quality impacts are being studied by the University of North Dakota and
Arthur D. Little, Inc.  At Martin's Lake, Texas, FGC wastes are being
placed in a lignite mine.  Data from this program were unavailable as of
December 1978.  Additional information will be required to correlate re-
sults of field studies with the results of lab and model tests.  An un-
resolved issue regards the effect of acid mine drainage, in contact with
FGD wastes upon stability.  To date this has been investigated  only with
respect to leachate formation.  Also along this  line  is the stability of
various combinations  of  fill materials  in the spoil pit:   FGC waste,
mine  tailings, overburden, etc., which has not been reported thoroughly
in  the lab or in  the  field.
Reclamation and Land  Use
      Disposal of  FGC  wastes  in operating surface or  underground mines  or
at  abandoned  mine sites  would  not  require "new"  land.   The use  of  aban-
doned mines as FGC disposal  sites  would appear  to be  a potentially ideal
disposal  practice, especially  where used to  limit acid mine drainage.
However,  disposal in abandoned surface mines, while  feasible,  is space
limited,  especially due to the reclamation requirements of the  Surface
Mining Control and Reclamation Act.  Disposal in underground mines may  be
 less feasible (except perhaps  in a few isolated cases) due to  abandoned
mine conditions.
      A recent review of the feasibility of operating mines as  disposal
 sites concluded that more than sufficient capacity existed in operating
 mines for the disposal of large quantities of FGC sludges.  From a tech-
 nical feasibility perspective, surface coal mines and underground room-
 and-pillar coal, limestone and lead/zinc mines were reported to offer the
 most promise.  Coal mines were considered the most likely candidates due
 to capacity and frequent association with power plants.
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     A major difference between landfilling of FGC wastes and surface
mine disposal is the ratio of sludge to overburden replacement.   The
issues of groundwater contamination and stability of FGC waste disposal
in a surface mine are presently being examined by the University of North
Dakota and Arthur D. Little, Inc. under EPA contract.  Results of this
program are not yet available.  Essentially, however, the major public
policy land use issues are the same as those discussed for dry disposal
above.  Slurried fly ash is being disposed of in an underground
mine in Pennsylvania.  Mine dewatering effluent has been reported within
regulated limits for iron, pH and suspended particulates and has reportedly
served to neutralize mine water to some extent.
     Given SMCRA requirements, it is reasonable to assume that; the degree
to which the physical or chemical characteristics of FGC waste materials
could affect post-mining reclamation efforts needs to be addressed.  The
potential for migration of FGC waste contaminants into surface soils and
vegetation would be of particular concern for surface mines located in
areas of prime farmland since restoration to agricultural production is
a distinct possibility.
     The existence of an underground mine would appear to be a more sig-
nificant post-closure land use limiting issue than the disposal of FGC
wastes in the mine.  Three areas of investigation relevant to this dis-
posal option are:
     •  The degree to which FGC wastes can ameliorate acid mine drainage,
     •  The long term potential for S0_ emissions, and
     •  The significance, if any, of waste corrosive activity on under-
        ground supports, especially where surface stability could be
        affected.
None of these issues  has yet been studied empirically as of this
writing.
Water Quality Issues
     The general discussions on water related impacts for dry disposal
options also apply here.  In addition, certain specific issues are
important.
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Deep Mines
     Water related impacts associated with deep  coal mine disposal of
FGC wastes are extremely difficult to assess because the hydrogeology
of mines is not well understood.   Mine disposal  is unique compared to
other disposal options in that it has the potential for alleviating an
unrelated environmental problem.   The alkaline nature of the FGC wastes
could tend to neutralize acid mine drainage while the sealing of mine
voids might reduce the generation of acid mine drainage.
     Lunt et al [29,38] assessed the potential impacts of disposal in
deep mines.  FGC wastes disposed of in deep mines would often be beneath
the water table and may interact directly with groundwater.  However,
because of the nature of the mine environment, mine drainage migrates
much more rapidly than other groundwater and often  follows  intricate
paths through voids, fissures, etc.  Furthermore, the mine  environment
may be aerated resulting in chemical alteration of  coal mine drainage,
which typically contains sulfuric acid.  Total oxidizable sulfur  (TOS)
associated with sulfite-rich wastes is a contaminant of potential  con-
cern in leachate.  The solubility of TOS in sulfite-rich  FGC wastes  has
been investigated on a laboratory scale by  Arthur D. Little, Inc.  in
                           I [        [ [
relation  to varying the Ca   and Mg   hardness and  sulfuric acid  concen-
tration of ambient water  [29,38].  Special  precautions  were taken  to pre-
vent the  aeration of samples  (to preserve dissolved sulfite).   Sulfite
solubility was  generally  reported  to be  about 30-70 ppm.   It was  found
that the  largest  influence  on  sulfite solubility  was the ionic  strength
of the background leaching  solution.  Sulfite solubility increased with
the ionic strength  in  these tests.
     Dissolved sulfite would pass  through the geologic profile  without
attenuation  along with the  other major  soluble  anions  in FGC waste
leachate  [38].
     Duvel,  Rapp  and  Atwood[63]  have also performed laboratory leaching
 tests  of  FGC waste  with a synthetic mine drainage solution.  They observed
 generation of a black precipitate of iron sulfide and slightly higher
 trace  metal concentrations with the acid leaching solution than with a
 distilled water leach.  They discussed various  mine disposal scenarios in
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some detail, concluding that complete sealing is necessary in order to
reduce or eliminate the production of acid mine drainage.  In view of the
engineering difficulties associated with placing the waste in all mine
voids, the feasibility of complete void sealing has not been demonstrated.
     The potential effects of runoff leachate from waters voluntarily
removed from deep mines containing FGC wastes (i.e., pumping to above-
ground storage ponds) have yet to be studied.
Surface Mines
     Dry disposal of FGC wastes in the spoil bank of surface mines presents
similar water related impact potential as other dry disposal methods.
Isolation of the wastes from the water table is technically feasible,
and groundwater impacts from typical, well-designed, well-run operations
would be expected to be relatively minor.
     A field-scale study of mine disposal alternatives is underway at
Square Butte, North Dakota.  One emphasis is on monitoring groundwater
quality.  Meaningful results would not be available for some years.  Dis-
posal operations at Martin's Lake may also yield useful monitoring data.
Surface impact potential is yet to be studied but is probably analogous
to that for dry disposal.
     Disposal on the mine pit floor, which is usually below the water
table, is therefore expected to have a higher potential for groundwater
impacts as described by Lunt, et al. [29,38] for several
surface mine disposal scenarios.  FGC wastes are being placed
in "v-notches" in the Square Butte study, providing planned opportunity
for monitoring of potential groundwater impacts in the future.
Other Environmental Assessment Considerations
     As for other land disposal options discussed above, potential issues
relating to air quality and biological impacts of FGC waste disposal in
mines have been identified, but subject to no empirical research to date.
     A potential for gaseous emissions (e.g., of SO ) from initial reac-
                                                   X
tions of alkaline FGC wastes with acid drainage in deep mines has been
Identified by Johnson and Lunt  [38].     No lab or field-scale research
on this subject appears to have been initiated.  Biological issues for
deep mine FGC waste disposal appear to be largely confined to potential
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impacts derived from water  quality changes.   No  direct  investigations
appear to have been initiated,  but the relative  impact  potential in
already disturbed mine environments appears  to be minor compared to that
of surface disposal options.
     Air quality and biological impact issues for surface mine disposal
are similar to those discussed above for other dry disposal methods.  These
issues do not appear to have received research attention to date.
Mine Disposal Demonstration at Baukol-Noonan
     The EPA is funding a mine disposal demonstration for FGC wastes at
the Baukol-Noonan mine in Center, North Dakota.   The project is being
funded as a part of the EPA's ongoing evaluation of the feasibility of
using the ocean and mines for disposal of FGC wastes.
     The wastes placed in the mine are being generated by a 450-MW alkaline
ash scrubbing system at Square Butte Electric Cooperatives  (Minnkota Power)
Milton R. Young Station.  The Milton R. Young Station  is a mine mouth
power plant firing  low sulfur lignite.  The  scrubber system using  the
alkalinity present  in the fly ash  for  SO- removal.  The  fly ash is  removed
ahead  of  the  scrubber system in  a  high efficiency  electrostatic precipitator.
It is  then conveyed to a storage silo  from which it  is fed  to the  scrubber
on demand.  The wastes produced  which  consist of 70-85%  fly ash and 15-30%
calcium sulfate  are dewatered by thickening  and filtration  to a solids
content  of 70-75% solids.   The  filter cake is loaded  into  dedicated 30-ton
trucks for haulage to the mine.
      The mine is  a surface  area strip  mine operating with  two draglines.
As  is  convenient, wastes are  placed either in the pit  bottom  after extrac-
tion of coal  and before  replacement of overburden; or  in the  v-notches
between spoil banks prior  to  reclamation.  Because of the  residual pozzo-
 lanic activity of the ash,  the wastes harden within a few days alleviating
 any stability problems in  overburden replacment or reclamation activities.
      The demonstration project involves monitoring of various sections of
 the mine to assess the impacts of waste disposal.  The monitoring of work
 is being performed under the direction of the University of North Dakota
 with assistance and guidance by Arthur D. Little, Inc.
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 4.3   Ocean Disposal
 4.3.1  Overview
      At present,  regulatory posture  does not  favor ocean disposal initia-
 tives nor  is ocean disposal of FGC wastes practiced.  However, if it
 could be practiced, ocean disposal may be an  attractive alternative in
 the  future in  the "Northeast.  In order to place  this disposal option in
 perspective, EPA  initiated assessment studies on ocean disposal at
 Arthur  D.  Little  and  the New England Aquarium, and is participating in
 conjunction with  EPRI and DOE in a program at the State University of New York
 To date both efforts  have focused on lab-scale and very limited field-
 scale studies;  further limited field-scale investigations are planned.
 Full-scale ocean  disposal of FGC wastes has not  taken place, limiting
 the  basis  for  empirical assessments  to the aforementioned studies, and
 making  definitions of "typical" operating practices somewhat speculative.
 4.3.2   Impact  Assessment
      The EPA-sponsored program being conducted by Arthur D. Little, Inc.
 has  focused on aspects of the physical stability, water quality, and
 biological impact potentials of unstabilized  FGC wastes.  Results have
 been reported  by  Lunt et al. [29] and Cooper  et  al. [31].
      Two types  of lab-scale tests of physical behavior of FGC wastes
 in seawater have  been completed in the Arthur D. Little program.  The
 first was  a series of "drop" tests to observe FGC waste behavior during
 descent  in a seawater column.  FGC wastes from direct lime processes
 exhibited  significant cohesion effects in this series of tests, while
 gypsum and  sulfite-rich dual alkali  filter cakes exhibited far less
 cohesion.   Mathematical modeling to  field-scale  based on these tests
 indicated  a wide  range of potential water column suspended solids con-
 centrations in  the immediate vicinity of descending FGC waste masses,
 ranging  from near zero to in excess  of 10,000 ppm [31].
     Based  on  these water column studies and modeling efforts the
Arthur D. Little  investigators designed laboratory bioassays using
 free-swimming marine  zooplankton and finfish reported to be relatively
 sensitive  to suspended sediments.   The results of these tests, performed
at the New England Aquarium,  were reported by Cooper et al. [33]:
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     •   A sulfate-rich FGC waste exhibited acute  toxicity only
        at suspended  sediment levels  in excess of 1,000 ppm.
        These levels  correspond closely to values reported  for
        a number of very  different, naturally-occurring and
        man-made sediments  for the same organisms.
     0   Sulfite-rich  FGC  wastes exhibited high toxicity under
        agitated (tank-scale) mixing  conditions.  Oxygen  depletion
        appeared to be  the  operative  mechanism of toxicity. The
        applicability of  these results at  field  scale is  con-
        sidered uncertain.
     The potential for  sulfite-related oxygen depletion was confirmed
by a series of laboratory dissolution/oxidation  studies,  also  reported
by Cooper at al.[31]  .   Figure  4.1  shows  the results of these tests
for several direct-lime system wastes.
     Cooper et al. [31]  also reported the results of lab and limited
field-scale observations of the  redistribution potential of unstabilized
FGC waste deposits on the ocean floor.  As shown in Figure 4.2,  modest
currents  in a shallow marine embayment were sufficient to  redistribute
mounds of FGC waste in less than one hour.  Based on these observations
and those in simulated flume tests,  the Arthur D. Little investigators
reported  that unstabilized FGC wastes appeared to have greater  redis-
tribution potential on the ocean floor than certain clay-like soils
and dredged material, and that benthic sedimentation was an impact
mechanism of potential concern for unstabilized  material.
     Recent  efforts  under this program have focused on lab-scale  tests
to determine long-term effects of major and minor unstabilized  FGC
wastes  on marine  water quality and biota.  A series of seawater leaching
studies (under  agitated  and quiescent leaching conditions) and  long-
term exposure  studies have been completed in 1978.  Preliminary results,
reported in the July through November Progress Reports for the  program,
indicate the following:
     •   Under  quiescent  conditions,  amounts  of  sulfite-rich FGC
         waste  that would be  toxic (by oxygen depletion)  if agitated
         in a closed  system,  can be compatible with prolonged  organism
         survival in such a system.
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                                                Initial Seawatcr Slurry Concentration
                                                       O   25 ppm
                                                       A  110 ppm
                                                       D  200 ppm
                                                          4700 ppm
                                   468
                                        Time (minutes)
               Oxygen Depletion vs. Slurry Concentration for Direct Lime Scrubber Waste
                                                Initial Seawater Slurry Concentration
                                                       Waste A (110 ppm)
                                                   4  Waste B (110 ppm)
            0          2          46          8          10         12
            %                            Time (minutes)
            Comparative Oxygen Depletion Rates for Different Direct Lime Scrubber Wastes
Source:   [31]
            Figure 4.1   Oxygen Depletion Rates  in Well-Agitated
                          Slurries of FGC  Wastes
                                       4-38

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   15
   10



'x

2   5
a
a
                             Mound 1

                              (Right)

                       Height  	•——


                       Width  —O—
          Mound 2

           (Left)




           —O—
                                                                     --a
              10
20        30        40


       Time of Test (minutes)
50
60
70
  Source:   [31]
           Figure 4.2  Observations  of Mounds of  FGC Wastes  Created

                       in Shallow Water Environment
                                       4-39

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     •  Leaching studies of Cd, Hg, Ni, Se, and Zn for several
        FGC wastes showed release of all but Hg under both
        agitated and quiescent conditions to detectable levels
        above those present in influent (Boston Harbor) water.
        For most of these metals, a correlation with the ash
        content of the FGC wastes appeared potentially sig-
        nificant. ;
     •  Exposure studies using FGC waste substrates and water
        column levels of metal derived from leaching tests appear
        to have produced potentially significant bioaccumulation
        of Cd, Ni and Se in invertebrate test organisms exposed
        for 45 days to ash-rich wastes.  Control organisms and
        those exposed to ash-free FGD sludge do not appear to
        have experienced similar bioaccumulation.
     Continuing work in this program is planned to focus on the
following areas:
     •  Interpretation of the results of the leaching/exposure
        studies with unstabilized FGC wastes,
     •  Comparable studies with several stabilized wastes (to
        be performed by the New England Aquarium under a separate
        EPA Research Grant), and
     •  Limited field-scale studies of potential water quality
        and biological effects of unstabilized and stabilized
        wastes in a saltwater pond.
     The results of the program to date appear to have reinforced initial
concerns about the environmental acceptability of conventional shallow-
ocean disposal (i.e., disposal on the continental shelf) of unstabilized,
sulfite-rich FGC wastes; and both shallow and deep ocean conventional
disposal of unstabilized FGC wastes high in ash and/or trace contaminants.
On the other hand, the program appears to have reinforced the possibility
for development of acceptable dispersed disposal techniques for unsta-
bilized, sulfate-rich FGC wastes low in trace contaminants,  either in
shallow or deep ocean situations.  Principal information gaps emerging
from the results to date include:
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     (1)   The implications  of  stabilization  on potential sulfite
          and trace contaminant  water  quality and  biological
          impacts,  and
     (2)   The applicability of lab-scale results  to  field-
          scale disposal situations.
     Studies of the potential  for cement-like  stabilized FGC  wastes to
be disposed of (or utilized) as artificial reefs  in  the shallow ocean
are being conducted by the Marine Sciences Research  Center of the State
University of New York at Stony Brook and the IUCS Corporation.  This
research is being supported by several agencies and has been reported
by Duedall et al. [73] and Seleginar [66].
     To date, the reported results of these studies have focused on
comparisons of the physical and chemical properties of the stabilized
wastes with those of concrete under seawater exposure conditions.  The
investigators have reported favorable comparisons (for the FGC materials)
from the standpoints of physical stability, trace metal leaching,  initial
organism colonization in an estuary, and metal uptake by  colonizing
organisms.  However,  the trace  contaminant  results  cannot be considered
definitive  in  the absence  of  comparisons with leaching accumulation
reference points for  non-anthropogenic  substrates.  Physical testing
results may also be further amplified by  planned  testing  of  FGC wastes
with more typical ash to sludge ratios, as  the mixtures tested initially
were reported  to be very high in ash  content.
     Future work under  this program is  planned to focus on in-situ
reef-building  simulations  in  the shallow  ocean.   Water quality and
biological  parameters are  scheduled for investigation.
 4.4 Assessment of Present Control Technology
 4.4.1   Introduction
     It  is  expected that much of the  difference  between potential and
 actual impacts of  the FGC  waste disposal  options discussed  above will be
 determined  by the degree to which  presently available control technology
 becomes incorporated as "good design" and "good  practice" in typical
 disposal operations.   Good design and practice could also minimize the
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potential for adverse impacts from abnormal events.  Scope and practice
of disposal systems were discussed in Section 2.2.5.  A number of control
technologies have been mentioned throughout the above portions of Section 4.
Some of the more important of them are summarized here.
4.4.2  Site Selection
     Site selection has been discussed earlier in Section 2.5.1.1.  Site
selection may or may not be considered control technology.  However,
there is no question that proper site selection could by itself ameli-
orate or eliminate most of the potential disposal impacts discussed
above.  Site selection can be used as control technology if the mitiga-
tive combinations and impact issue categories mentioned below are
considered applicable.
Potential Impact Issue        Mitigative Site Characteristics
     Land Use                 Proper topography, geology and
                              hydrology; absence of nearby
                              conflicting land uses.
     Water Quality            As above for land use, plus
                              absence of nearby sensitive re-
                              ceiving waters (surface or aquifers).
                              For example, a small stream or
                              aquifer may impose greater con-
                              straints than a large stream or
                              impure aquifer.
     Air Quality              Absence of "non-attainment area"
                              and Class I Prevention of Signi-
                              ficant Deterioration designations
                              for total suspended particulates.
     Biological               Absence of sensitive biological
                              resources.
     It is reasonable to assume that sites offering the greatest number
of mitigative characteristics would be the best available for FGC waste
disposal from an environmental standpoint, and could, in some cases,
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make the application of certain control techniques unnecessary that
might be required at more sensitive sites.   Exceptions to this generality
would be sites with many advantages combined with one or more major
disadvantages.
A.4.3  Waste Processing Options
     In addition to judicious selection of the optimum site, the designer
of an FGC waste disposal system has three waste processing options to
mitigate adverse environmental impacts.
     •  Dewatering,
     •  Forced Oxidation, and
     •  Stabilization.
These have been discussed in Volume 3.  Brief comments on their role as
control technology is offered below.
4.4.3.1  Dewatering
     As discussed above, dewatering of FGC waste  prior  to land disposal
can result in major improvements in physical  stability  and  water  quality
impacts due to reduced leachate migration and reduced volume of poten-
tially contaminated overlying water (in wet impoundments).  As discussed
immediately above, dewatering may  be  particularly important in the dis-
posal of sulfate-rich  FGC wastes.  Dewatering,  like  the disposal  of
relatively impermeable,  stabilized wastes may require greater consider-
ation of disposal  area runoff management, in  order to avoid adverse
water quality effects  by that route.
4.4.3.2  Forced  Oxidation
     The intentional  production of sulfate-rich,  rather than sulfite-
rich FGC wastes,  is presently  a subject  of  considerable interest.  In
ocean disposal,  the sulfate-rich products of  forced  oxidation would have
the obvious advantage of mitigating the  potential for sulfite-related
depletion  of  dissolved oxygen.  This  advantage  would be shared in land
disposal operations  (especially wet impoundments), but  its  relative
importance is less clear.   A dominant question  concerning the mitigative
potential  of  forced oxidation for  land disposal is whether or not the
process results in increased or decreased physical stability.  Based on
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experience with soils, gypsum FGC wastes comprised of relatively uniform,
sand-sized particles may exhibit considerable failure potential in the
absence of:  1) effective compaction and dewatering, and/or 2) co-disposal
with materials of varying particle size.  However, if FGD gypsum is
analogous to phos-gypsum, recrystallization mechanisms occurring in the
disposal pile may improve stability.
4.A.3.3  Stabilization
      The advantages of chemical stabilization of  FGC wastes as a means
of  mitigating  a variety  of potential impacts have been discussed through-
out Section  4.  Stabilization processes are discussed in Volume 3.
Stabilization  appears to be highly  relevant to the mitigation of land
use issues,  including the potential for abnormal  events  (i.e., disposal
area  liquefaction or other catastrophic failure modes), and the suita-
bility of disposal sites for a broader range of post closure uses
requiring Increased bearing strength.  Stabilization techniques resulting
in  decreased waste permeability can be considered mitigative of poten-
tial  water quality impacts due to leachate migration.  This factor can
be  weighed in  balance on a site-specific basis with the opportunities
for disposal area runoff control, since that mechanism could be of
greater importance than  leachate for contaminant  transfer from stabilized
FGC wastes.  It is also  unclear whether or not stabilization would reduce
the overall, long-term chemical mass balance of contaminant migration
from  a given waste disposal area.   In particular, it is not clear that
reductions in  long-term  trace contaminant availability would take place
when  fly ash is used as  a stabilization additive  to an otherwise rela-
tively contaminant-free  FGD sludge.
      Cementitious stabilization processes may also be considered
mitigative of  the potential for post-disposal fugitive particulate
emissions from dry FGC waste disposal operations.
      In ocean  disposal,   cementitious stabilization may remove liabilities
of FGC wastes as benthic substrates and as sources of sulfite-related
depletion of dissolved oxygen.  However, questions of sulfite and trace
contaminant availability, among others, preclude  definitive judgment
on this issue at this time.
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4.4.4  Use of Liners
      A basic option to control flow of  leachates  in ponding  operations
and generically applicable to dry disposal if site specific conditions
warrant it is the use of liners.   Liners are now under study  at  WES and
by EPRI [15]; these studies were discussed in Section 2.2.1.
4.4.5  Co-disposjil of Wastes and Creation of Waste/Soil Mixtures
     Although the term co-disposal is often used in reference to the
creation of disposal mixtures of two waste streams (e.g.,  FGD sludges
and coal ash), it is used here to imply  a broader  range of opportunities.
Specifically, for land disposal of FGC wastes, "co-disposal"  might also
include the application of technologies  for the creation of  soil/waste
mixtures.   If soils with the proper characteristics are available, the
creation of soil/waste mixtures may be an alternative to the addition
of fly ash where only limited increases in physical stability are desired
in a disposal operation, or where trace contaminant availability needs
to be reduced to facilitate revegetation or decrease water quality impacts.
Traditional co-disposal involving fly ash plus  FGD  sludge appears  to have
substantial advantages over independent disposal  in terms of improved
physical stability and  (potentially) decreased  permeability.  This might
be especially relevant  to sulfate-rich FGC wastes of uniform particle
size.   (See Section  4.4.4 above.)  However,  in  some situations the extent to
which the ash serves as a reservoir  of certain  trace contaminants  could
prove a liability  from  the standpoint of potential  water quality
degradation.
 4.5   Summary of Data Gaps and Future Research Needs
      A number of programs have been undertaken (and are in progress) by
 EPA, DOE, EPRI, and others.   These efforts have provided much of the
 baseline  information for environmental  assessment.  Provided these
 programs  continue, additional data and  insight permitting better
 environmental assessment will be possible.
      A number of data gaps concerning FGC waste generation,  character-
 istics, and utilization have been identified in Volumes 3 and 4.
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In this subsection data gaps and research needs pertinent to environ-
mental assessment of FGC disposal are enunciated.  Data gaps apparent
as of early 1979 are listed in a generally descending order of priority
below.
     a.  Acquisition of field data on the actual impacts of full-scale
         disposal operations under varying environmental conditions.
         Field-scale monitoring of large disposal operations over a
         period of several years is warranted.  EPRI's proposed program
         at Conesville Plant of Columbus and Southern Ohio Electric is one
         such example.  EPA is also planning an extensive 2-year study
         on characterization and environmental monitoring of sixteen'(16) full-
         scale utility disposal sites in support of the further development
         of RCRA regulations.
     b.  A corrollary of (a) above would be the development of correla-
         tions and tools of extrapolation to relate existing lab/pilot
         scale data on physical stability and water quality impacts  to
         full-scale field data.
     c.  Integrated study and evaluation of the environmental trade-offs
         in co-disposal of various FGD wastes and various coal combus-
         tion ashes.  (It appears that this type of initiative could
         emphasize laboratory work with limited pilot and full-scale
         field verification.)
     d.  Development of basic data (laboratory and field-scale) on the
         biological impact potential of principal land-based FGC waste
         disposal options, especially data relating to water-related
         impacts of major soluble species and trace contaminants.
         Typical questions are:
         •  What are the biological and health effects of mixtures
            of trace metals (in the form found in liquors), such as
            zinc, copper, lead, mercury, cadmium or nickel in combina-
            tion with selenium in particular, but also in other
            combinations?
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        •  What is the uptake of potentially toxic materials by
           vegetation and wildlife associated with disposal
           areas?
        •  What are the levels of ambient concentration of
           waste-related potentially toxic materials in
           vegetation and surface water that may produce
           chronic health problems for wildlife?
        The answers to these questions would help implement the
        "Environmentally Sensitive Areas" provisions of pending
        RCRA regulations.  EPA is presently supporting biological
        testing work on FGC wastes at Oak Ridge National Laboratory.

     e.  Development  of basic  (laboratory and field)  data on the poten-
        tial  for fugitive  particulate  emissions from areas previously
        used  for the dry disposal of FGC wastes.
     f.  Socio-economic  impacts  of FGC waste disposal on land need to
        be better defined.
     In the future, FGD  waste generation will not be limited to those by
utility systems.   Coal utilization in industrial boilers (25 MW or larger)
is also likely to grow substantially.  FGD wastes from such industrial
boilers (while analogous in composition to those from utility boilers)
present additional waste management issues due to differences in distri-
bution of generation facilities, in quantity of FGD wastes generated at
each facility and other factors.  These issues also require further
evaluations and study.
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5.0  REVIEW OF MONITORING CONSIDERATIONS
5.1  Regulatory Requirements for Disposal
5.1.1  Land Disposal Monitoring
     Proposed regulations under the Surface Mining Control and
Reclamation Act of 1977 (SMRCA) and the Resource Conservation and
Recovery Act of 1976 (RCRA) contain provisions for implementing one
or more kinds of environmental monitoring activities which may effect
the disposal of FGC wastes in mines or impoundments.
     The recently published proposed rules for a permanent regulatory
program for surface coal mining and reclamation operations (30 CFR) [77]
require both plans and mechanisms for implementing monitoring programs
in the following areas.
     •  Groundwater monitoring  is required  of  the  operator for
        both  surface and underground operations in order to
        ascertain whether  the water quality and recharge capacity
        have  been unduly effected by mining operations [78].
        However, details of  such monitoring programs,  including well
        placement,  frequency,  etc. are  site-specific,  and will be
        decided by  the regulating  authority on a  case-by-case
        basis,  and  incorporated into  the reclamation plan [79].
        Monitoring  is  continued until  reclamation is complete.
      •  Surface water  discharges must  also be monitored by the
         operator;  this is accomplished with approval from the
         regulating  authority in conjunction with  the NPDES
         permit requirements during mining operations [78].
         However,  the SMCRA surface monitoring must be continued
         after active mining has ceased until reclamation for
         post-mining uses is complete.
      •  Water parameters which are to be monitored  and  for which
         limits are set include pH, total iron, total manganese  and
         total  suspended solids [79].  Hydrologic parameters
         (i.e., flow) are also  required.   In addition,  other
         parameters characteristic of the discharge  may  be
         requested by  the  regulator.

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     •  Fugitive dust emissions must be monitored where required in
        order to show compliance with applicable air quality standards [79]
     Proposed guidelines and regulations for hazardous wastes under RCRA
were published in December 1978 [80].  These guidelines and regulations
are now under review and may undergo significant modifications prior to
scheduled promulgation in late 1979.  Under these regulations (discussed
more fully in Section 3) wastes will be tested to determine if they
are hazardous.  On the basis of such future tests, FGC wastes may be
classified as non-hazardous or as a special case of hazardous wastes.
However, if the initial characterization of these materials causes some
of them to be classed as hazardous waste [82], then these wastes
together with processing and handling operations will be subject to the
following monitoring requirements:

     •  The waste itself is subject to an initial detailed analysis
        and then must be monitored on a frequent (truckload or batch)
        basis for at least physical appearance, specific gravity, and
        pH, unless the operator can demonstrate that the state of system
        control does not necessitate such frequency [83].
     •  A groundwater monitoring system, consisting of at least one
        well upgradient and three wells downgradient from the disposal
        site, must be utilized to check water quality.  Sampling fre-
        quency will vary from annual to quarterly depending on water
        flow [84].
     •  Minimum analyses of groundwater samples will include conductivity,
        pH, chloride, total dissolved solids, organic carbon and the
        principal hazardous constituents or indicators found in the
        waste.  A more comprehensive analysis including the above
        constituents plus beryllium, nickel, cyanide, phenols and
        chromatographable organics may be required [84].
     •  The groundwater monitoring program must be set up to continue
        for up to 20 years following closure of the site unless it can
        be shown that monitoring for that length of time is unnecessary [84],
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5.1.2   Ocean Disposal Monitoring
     Regulations establishing the criteria for evaluating permit applica-
tions for ocean dumping and for management of ocean disposal sites have
been promulgated [85].  Part 227 deals with the criteria for the evaluation
of permit applications for ocean dumping of materials, while Part 228
deals with criteria for management of the ocean disposal sites.   Ocean
disposal is regulated by the EPA.  EPA's current policy is to discourage
ocean disposal especially if alternate means of disposal are available.
However, If ongoing EPA studies indicate ocean disposal is stable, the
situation may change in the future.  This discussion  on ocean disposal
monitoring is against this perspective.  The following points may impact
on the potential for disposal of FGC wastes.

      •  Where possible,  bioassays employing appropriate sensitive marine
         organisms,  rather than measurement of specific constituents,
         are used to assess the impacts of suspended particulate
         wastes [86,87].
      •  Each disposal site must have an impact monitoring program.
         Such programs may include a series of baseline and trend
         assessment surveys to document and assess changes at the
         site.  Federal agencies (EPA, NOAA) will have major responsi-
         bility for these surveys.  Permittees will be required to
         participate in the development and implementation of monitor-
         ing plans [88].
      •  Under Part 228.13 [88], guidelines for monitoring programs
         are established with respect to:
              Timing of surveys, particularly for seasonal variations;
              Duration of surveys;
              Numbers and locations of sampling stations in dump
              and control areas;
              Water quality test parameters, including nutrients,
              heavy metals, pesticides and  other organic materials.
              In addition, "analysis  for  other constituents character-
              istic of wastes  discharged  ... will be  included in
              accordance with  the  approved  plan of  study."  [88];
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             Locations of sampling points in the water column
             for both chemical and biological sampling, and the
             number of samples;
             Numbers of samples and general locations for bottom
             sampling for both biotic and chemical tests; and
             Measurements of current and water mass measurement.
     The intent and focus of the regulations is to make maximal use
of biotic measurements for monitoring purposes as well as for permit
approval.

5.2  Screening Tests for Solid Wastes
     In keeping with an increased awareness of the need to control the
disposal of wastes which may have adverse impacts on the receiving area,
there is a generally recognized need for some type of screening test
which can be performed on the wastes prior to disposal in order to
show whether a waste meets criteria of acceptability established for a
particular disposal situation.  The need to conduct such tests on a peri-
odic basis in order to monitor the quality of waste during continuing dis-
posal operations has been addressed in part in the recent RCRA proposed
regulations for hazardous wastes [83].  These regulations contain an Advanced
Notice of Proposed Rulemaking, provisions of which are summarized below.
     Under the RCRA proposal such screening tests for solid wastes would
be comprised of three steps or operations:
     •  Sample pretreatment such as size reduction, physical
        stressing or phase separation (for wet solids)  carried
        out prior to extraction.
     •  Extraction or exposure to leaching agents.   Both the
        extraction procedure and the chemical properties of the
        extractant will affect the results.
     •  Testing of the extract (and, in some cases, the eolid phase)
        using chemical and/or biological method.
     At this time, application of such tests to FGC wastes and definition
of appropriate conditions for each step are still very much in a state of
flux.  An ASTM/DOE collaborative program has proposed methods for leaching
of waste materials [89,116].   EPA sponsored a project at Oak Ridge National
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Laboratory (ORNL)  to test toxicity of  leaches  from several wastes  includ-
ing FGC wastes.   Preliminary results are reported  [115]  on a limited
number of samples.   Investigations are continuing  and  have not  reached
a definite stage to broadly assess whether FGC wastes  are non-hazardous
and under Section 4004 or special wastes under Section 3004. Lowenbach
has published a comprehensive compilation of the variety of  leaching
test methods which have been used and  proposed prior to 1978 [90].
5.2.1  Sample Pretreatment
     Sample pretreatment should reflect both the form of the waste
(granular, monolithic block, etc.) and anticipated stresses  to  which
the waste may be subjected both during and after disposal (compaction,
freeze-thaw, etc.).  At present, significant differences which exist
between test procedures are due in part to expectations  of pre- and
post-disposal conditions.  The recent RCRA-proposed rules indicate
that solids either may be ground  (if necessary) to pass  through a
9.5-mm standard sieve or may be subjected to specified physical
stresses  (multiple blows) in a "structural  integrity  tester" of special
design  [82].  An ASTM proposed leach test (from 1978) did not  call for
any size  changes since "... The wastes used in this test shall be
tested in the form in which they will be discarded" [89].   The test
procedures used by IU Conversion  Systems, Inc. utilize materials  from
real or simulated field  conditions; for monolithic stabilized  wastes
circular  slices from a standard Proctor Compactor are used  [90].  It is
anticipated that the public comments received by  EPA  on  the proposed
regulation  for hazardous wastes will foster further discussion, and
possibly  aid in resolution  of differences.
5.2.2  Extraction Procedure
     Tests  employed  for  FGC wastes  have  included  both elutriation (shake
 tests)  and  column  leaching  procedures.  Both  procedures  have particular
 advantages  when properly carried out.   For  example, shake tests  can more
 closely  simulate  surface effects  as from runoff,  while  column  leaching
 can more closely  simulate actual percolation  leaching.   As  yet,  there  is
 no clearly  defined rationale  for selecting one method over  the other,  and
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 adoption  of more  than  one  method  may be necessary  in  order  to accommodate
 the need  for various disposal mode alternative  elutriation  tests  [90],
      Likewise,  the  composition of the  leach  solution  (extractant) is also
 under active discussion  and  investigation.   While  there appears to be
 a feeling that  som*1 sort of  acidic solution  may be appropriate, there
 is  much controversy over  the amount of acid, control of pH and the effect
 of  the extractant on subsequent tests.  The  method in the proposed RCRA
 regulations for hazardous  wastes  calls for maintaining a pH of 5.0 - 0.2
 by  adding a maximum of 4 milliliters of 0.5  molar  acetic acid per gram
 (dry)  of  waste  solids  [82].   This is now  under  EPA review and may be
 modified.

     ASTM/DOE program on testing coal combustion wastes is evaluating
 EPA and ASTM methods for extraction.
     The ocean dumping regulations under  MPRSA are explicit,  and call
for extraction of the wastes with seawater [85].
5.2.3  Testing of Extracts
     In previous work,  nearly all tests carried  out on extracts have been
chemical rather than biological, due in part to  the relative difficulty
of performing controlled biological tests and to the lack of standard
test methods data on appropriate standards for interpretation and com-
parison.   As discussed later in this section, this situation is changing
rapidly as more biotic tests are being developed.  The recently proposed
RCRA tests address only a very small number of the potentially important
aspects of waste biological effects, and may foster further discussion.

     In general, the chemical composition of extracts is measured by the
methods described below.  The resulting data are most usually compared
with standards  for water quality, such as for drinking water.
     The ocean  dumping regulations under MPRSA calls  for both chemical
and biotic  tests of the waste-seawater leachate and solid phases [85],
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     The Industrial Environmental Research Laboratory (Research Triangle
Park) of EPA has recently initiated studies at Oak Ridge National Labor-
atory [46] of the applicability of the proposed RCRA extraction procedure
and biological tests to FGC waste materials.  The results of these
studies are expected to be available in 1979.   Further biological testing
is also anticipated as part of the comprehensive, pending EPA-sponsored
field study in support of definitive RCRA-related regulation of disposal
of utility solid wastes.

5.3  Water Monitoring Methods
5.3.1  Methods for Freshwater
     Included under freshwater are groundwaters and surface waters asso-
ciated with landfills and mines.
5.3.1.1  Sampling Methods
     An extensive compilation and comparison  of methods  for sampling and
analysis of groundwater and surface waters  at  solid waste disposal sites
has been published recently  [91].  This manual provides  an  extremely
useful summary of methods for siting, developing and  using well  arrays
for groundwater monitoring.  In addition,  collection  and pretreatraent of
surface waters is covered in the EPA  [92]  and  APHA  [93]  manuals.
     Of particular importance for FGC wastes  which  contain  sulfites,
groundwater samples intended for measurement  of  sulfite  or  dissolved
oxygen must be taken  and protected  from atmospheric  oxygen  by  use of a
mechanical pump  or a  small  "grab" sampler.
5.3.1.2   Analytical Methods
     There are a number of  manuals  describing standard analytical methods
and  procedures which  are applicable to freshwater  [91,92,93].   Analytical
methods are  undergoing continual  improvement  in  sensitivity as for  example
in the  use  of high-temperature  furnaces and plasmas  for spectroscopic
measurement  of  metals and  ion-chromatography  for measurement  of many  trace
ionic  species.
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 5.3.1.3  On-Site Continuous Analyzers
      The two:jnajor alternative approaches to the sampling and  measurement
 of groundwater constituents involve either real-time,  in-situ  measurement
 of components of the sample stream or removal of discrete grab (or
 integrated) portions of the sample stream for subsequent measurement.
      The in-situ measurement approach eliminates the need for  sample
 handling (with the attendant possibility of contamination);  however, the
 number of different monitoring devices (or "probes") is extremely limited
 at this time (conductivity, pH, Cl, Na and dissolved oxygen) and,  in
 general, the long-term accuracy (drift)  of those is  so poor  as to require
 frequent calibration checks.   Only conductivity represents a real possi-
 bility for such monitoring and has been  used frequently in groundwater
 monitoring programs.  For disposal of FGC wastes,  the  predicted leaching
 behavior for all species suggests  that concentration changes should be
 sufficiently slow so that continuous monitoring would  not be required.
 5.3.2   Methods  for  Ocean Monitoring
     Ocean  disposal is not  practiced  today.  Current EPA policy  is  to
 discourage  new  ocean disposal  initiatives.  However, if ocean disposal
 is practiced  in the future, monitoring of  FGC ocean disposal sites  can
 require comprehensive baseline  and trend surveys covering  all aspects  of
 the ocean environment, and may  include some shorter-term studies relating
 to dispersion ("initial mixing") of the waste immediately  after dumping  [80].
 Because of  factors  such  as  accessibility and cost for multiple sampling
 points  in oceanographic  studies, the development of on-site continuous
 monitors for parameters  of  interest such as salinity, pH,  temperature
 and turbidity has proceeded much farther than for equivalent groundwater
 tests.   Still, measurements of most chemical and many biological parameters
 of interest, and especially those related  to hazardous characteristics
must involve discrete laboratory tests.

 5.3.2.1 Sampling Methods
     Equipment  to obtain samples of water  from  various  depths  (for  example
 Nansen  bottle and Van Dorn  samplers)  and samples of bottom sediments
 (grab and bucket samplers as well  as  corers such as the Phleger)  are
 well known  and widely used  in  the  United States  [29,95].
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5.3.2.2  Analytical Methods
     Methods for the chemical and physical analysis  of water and solids
from ocean sampling have been described extensively.   A survey of some
state-of-the-art methods for trace level measurement of metals and
organics has shown that many of the methods used in  freshwater measure-
ments can be applied, with some modifications, equally well to seawater
[95].
5.3.2.3  On-Site Continuous Monitors
     As noted previously, a variety of on-site monitoring devices have
been developed for ocean water-column monitoring.  Parameters include
salinity, temperature, current velocity, pressure and turbidity  [29].
Gathering such baseline data without need  for active  sampling and
analysis may be useful for disposal and dispersal measurement for FGC
wastes.
5.4  Fugitive Emissions Monitoring
     Measurement and  abatement of  fugitive emissions  as  stipulated  under
the  Clean Air Act  are required under both  the SMCRA (Part 816.95) and
RCRA (Part  250.42-3)  proposed  regulations  [9,77].   The ambient  air  measure-
ment methods are given  in 30 CFR 780.14  and include use of "Hi-Vol"
samplers.

5.5  Biological Monitoring
5.5.1   Introduction
     Considerations of biological monitoring for FGC waste disposal
operations can be grouped into three categories:
     •  Baseline  (pre-disposal)  monitoring requirements,
     •  Pre-disposal bioassay testing, and
     •  Compliance monitoring during and after disposal operations.
In general, the use of biological monitoring as a regulatory tool is a
relatively new development.  Accordingly,  there is little practical
experience with the application of criteria and techniques  discussed
below.  For ease of interpretation, the discussion is  organized  to
correspond to the particular regulations that are the  source of  mon-
itoring requirements  in each of  the three  broad categories  just  identified.
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 5.5.2  Predisposal Baseline Surveys
     Two bodies of federal regulations require monitoring of baseline
ecology at prospective disposal sites prior to their use for disposal.
These regulations are:  those derived from the Surface Mining Reclamation
and Control Act, and those derived  from the Marine Protection Research
and Sanctuaries Act.  By definition, these regulations would be applicable
to only two of the disposal options considered throughout this report,
i.e., disposal in surface mines and disposal in the ocean.
     Regulations to implement the Surface Mining Reclamation and Control
Act are still emerging as of this writing.  The proposed rules for the
permanent regulatory program published September 18, 1978 [77] indicated
that the following types of  baseline biological data could be required
of applicants prior to the commencement of mining operations:
     •  Identification and vegetative mapping of proposed vegetation
        reference areas, and
     •  Specific species inventory,  habitat discussion, and protection
        plans for fish and wildlife resources.
     Neither of these requirements  would be directly related to the use
of the surface mine for FGC waste disposal.  Rather, they would be
required of the applicant for a proposed mining operation.  However,
the effects of FGC waste disposal on the resources identified in this
base line survey, should such disposal be practiced as part of an
eventual reclamation plan, would be of relevance.   Requirements for
this type of post-operations survey are discussed in Section 5.5.4 below.
     The final revisions of regulations and criteria for ocean dumping,
published by the EPA on January 11, 1977 [85]  include potential require-
ments for the accomplishment of extensive base line monitoring of
biological parameters as part of the disposal  site designation process
(Section 228.4 of the regulations).  Criteria to be investigated in
these types of surveys are not specified in great detail by the regu-
lations but include location in relation to breeding,  nursery,  feeding,
or passage areas of living resources in adult  or juvenile phases and
potentiality for the development or recruitment of nuisance species in
the disposal site.   If FGC wastes were to be disposed of in an existing
                                  5-10

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site, this type of monitoring requirement would not be applicable.  If,
however, a new site was proposed for FGC waste disposal, then such pre-
disposal monitoring could be required.  These surveys are identified as
responsibilities of the federal government (EPA has primary responsibility
with support from the National Oceanic and Atmospheric Administration).

5.5.3  Predisposal Bioassay Testing
     Bioassay testing to measure the apparent toxicity of wastes  has
become an increasingly important tool in the  evaluation of solid  waste
disposal options.   In several cases, bioassay results are becoming
formal considerations to complement or replace traditional measurements
of potential toxicity based on physical or chemical evaluations.   Four
bodies of federal regulation have potential implications of this  type
for FGC waste disposal:
     •  Resource Conservation and Recovery Act,
     •  Toxic Substances Control Act,
     •  Federal Water Pollution Control Act, and
     •  Marine Protection Research and Sanctuaries Act.
     Unlike the criteria for baseline surveys described  above, requirements
of bioassay testing under  these regulations would be  specifically applicable
to FGC wastes, either on a generic or case-by-case basis.

      Throughout this report the importance of the potential designation
 of wastes as "hazardous"  under RCRA has been emphasized.  The Act requires
 EPA to consider the toxicity and bioaccumulation potential of wastes in
 reaching a determination of whether or not that waste is hazardous.  EPA
 has been developing test protocols that emphasize certain aspects of the
 acute and chronic toxicity of wastes, measured for specific types of
 organisms.  More complex considerations, such as bioaccumulation and
 carcinogenicity, have been given less testing (and more theoretical)
 emphasis because of the relatively great difficulty  in achieving test
 results that have a high  degree of certainty [95].   The proposed RCRA
 hazardous waste guidelines published on December 18,  1978  [80, Part
 250.15] list tests  for mutagenicity and a theoretical estimation method
 for bioaccumulation which are  to be applied  to  specific wastes  (FGC  not
                                  5-11

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 included)  if an applicant wishes to demonstrate  that  such waste  does not
 have adverse biological effects.   The bioaccumulation estimation is one
 that relies on measurement of waste partition coefficients,  and  is
 more relevant to lipid-soluble organic substances than to FGC wastes.
 EPA has also published an advanced notice  of proposed rule making
 [80] in which public comment is requested  regarding the
 application of specific biological tests for toxicity including  muta-
 genicity,  DNA repair and bioaccumulation.   It is not  clear whether
 "special wastes" such as FGC wastes would  be subject  to these tests.
 This Notice proposes a few relatively standard bioassays involving  the
 use of one type of zooplankter, and terrestrial  vegetation  [80].  The
 resolution of this type of testing requirement could  have important
 implications for the degree of biological  monitoring  required of FGC
 wastes.
      The Industrial Environmental Research Laboratory of EPA
 has current contract programs, both at Oak Ridge National Laboratory
 and at Bionetics Division of Litton Industries,  to investigate the
 effect of  FGC wastes, among other materials, on  various proposed bio-
 logical test systems.

     ASTN Subcommittee D19.12  (Pollution Potential of Leachates from
 Solid Waste) is also  active  in  the area of biological testing of solid
waste extracts, and currently has two Task Groups working on muta-
 genicity and biological activity protocols  [96].
     Testing requirements under the Toxic Substances Control Act  (TOSCA)
 could be applicable to FGC wastes in conjunction with their prospective
utilization.  While this is not strictly a disposal consideration, the
 test protocols and implications can be considered similar to those
described immediately above for RCRA regulations.
     Bioassay testing is assuming greater importance in the imple-
mentation of the Federal Water Pollution Control  Act as emphasis moves
to the regulation of  "toxic" or "priority" pollutants.  If effluents
from FGC waste disposal operations are regulated  as point-source dis-
charges under NPDES permitting procedures,  permit review agencies have
the opportunity to apply bioassay tests to the effluent in addition to
                                  5-12

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(and in some cases,  in place of)  traditional  chemical  analyses.   To
date, there has been some use of  this option  in federal implementation.
Specifically, the regulations governing ocean outfall  discharges have
described acute toxicity testing  requirements,  coupled with possible
chronic toxicity and accumulation tests.  The bioassay approach is
appearing in various state and local level programs as well.  For example,
a Colorado guideline undergoing public hearing in November 1978 allowed
the use of bioassay results obtained by testing ecologically or econ-
omically important and sensitive species as an alternative to other
existing effluent limitations for many toxicants.  Ohio regulations
indicated that all pollutants or combinations in a discharge cannot
exceed one-tenth the 96-hour LC^Q for representative aquatic species.
It also includes a more stringent application factor  (1/100) for per-
sistent toxicants.  As more states assume implementation responsibilities
and NPDES permitting authority, the  likelihood of FGC wastes undergoing
aquatic bioassay evaluations is expected to  increase.

     The EPA ocean dumping regulations  [85]  require bioassay testing
of "appropriate  sensitive marine organisms"  with  candidate wastes for
ocean  disposal.  This would  include  testing  with  representatives  of
phytaplankton  or zooplankton, crustacean or  mollusk,  and  fish  species
at the EPA's discretion.  If FGC wastes are  considered  to  have  a  "solid
phase," similar  testing with benthic organisms  (filter feeders, deposit
feeders,  and burrowers) would also  be required.   The  test  requirements
for  ocean  disposal  are  determined on a case-by-case basis, but  their
scope  includes consideration of  acute and  chronic toxicity as  well  as
bioaccumulation potential.
5.5.4  Biological Monitoring for Disposal  Operation Compliance
      Present regulations under  three statutes define  biological moni-
 toring that would  be applicable  to  ongoing disposal  operations.  The
 statutes are:   Surface Mining Reclamation and Control Act, Federal
 Water Pollution Control Act, and Marine Protection Research and Sanc-
 tuaries  Act.
                                   5-13

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     If FGC wastes were disposed in surface mines, the effects of this
disposal would be evaluated in the context of the overall mine rec-
lamation effort.  Accordingly, the types of regulations under con-
sideration by the Department of the Interior could require continuing
monitoring of the success of revegetation efforts.  The proposed final
rules on Surface Mining Reclamation and Enforcement Provisions [77] in-
cluded a requirement to evaluate vegetative species diversity, distribution,
seasonal variety and vigor.  For the production of agricultural crops,
the crop production on a mined area compared to that of a reference
area would be evaluated.  For determining compliance, production would
be considered "equal" on the mined area if it equaled 90% or more of
that on the reference area for a minimum of two growing seasons.  Base
line survey requirements for the determination of reference areas are
discussed above in Section 5.5.3.
     State initiatives in the enforcement of the Federal Water Pollution
Control Act sometimes include biological monitoring requirements.  For
example, Florida measures effects on the "biological integrity" of the
area receiving an effluent discharge as an alternate index on environmental
impact [97].  The Florida criteria indicate that the Shannon Weaver
diversity index for benthic macroinvertebrates cannot be reduced to
less than 75% of background levels, determined by triplicate sampling.
This type of criteria is not yet common.  However, some local enforce-
ment agencies, such as the Erie County Department of Health in
Pennsylvania, use combined biological and chemical monitoring as a
means of "red flagging" potential leachate problems from solid waste
disposal sites.  Because, in some cases, this approach may be less ex-
pensive than monitoring an increasingly long list of chemical constituents,
it is reasonable to expect more enforcement agencies to consider its use.
     Site monitoring during disposal operations is also a continuing
responsibility of the federal government under the Marine Protection
Research and Sanctuaries Act.  Ocean disposal of FGC wastes would be
subject to such monitoring.  Biological considerations would include
the following:
                                  5-14

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      •  Absence  from  the  disposal  site of  po]lution-sensitive
         biota  characteristic  of  the  general  area,  and
      •  Progressive,  non-seasonal  changes  in composition  or
         numbers  of  pelagic, demersal or  benthic  biota at  or
         near the site.
Continued use of  a disposal site  could be contingent  on the results  of
these monitoring  programs  [85].
      Biological  testing is assuming  increasing importance in  assessing
the real environmental impacts on disposal  sites, and for  providing
guidance on long-term  genetic  and toxic effects.   At  this  time,  research
support is needed in the development  of  improved biological tests which
can be applied to samples  obtained  from laboratory or field monitoring
studies.  Also of high priority is  the need to establish appropriate and
acceptable protocols for the predictive testing of solid wastes.  Lesser
priorities concern the need to support R&D field studies for testing and
improving monitoring tests.
5.6  Monitoring of Physical Properties
       To date virtually all of the planning  and  implementation  of
monitoring programs for FGC waste disposal has centered around  the
concentrations of and transport of substances which  are potentially toxic
or hazardous to  the health of various life forms.  However, the potential
impacts which  the physical stability of  emplaced FGC wastes may have on
both site  operations  and  post-operational  use  of the site warrants  some
consideration  of possible efforts  to monitor appropriate  physical properties.
At present,  there are no  federal regulatory  requirements  for monitoring
physical stability  of materials  involved in  FGC  waste disposal.  Should
such monitoring  become  desirable,  the Army Corps of  Engineers has estab-
 lished procedures for in-situ physical tests,  as part of  the  guidelines
 for  dam inspection, which may be appropriate for FGC materials.
       In-situ measurements which may be  useful in assessing  stability
 of emplaced wastes include changes in strength and degree of saturation
 as a  function of depth.  The techniques  for making these measurements
 are used in civil engineering programs,  such as dam  inspection, and may
                                    5-15

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need to be brought to bear on FGC wastes in order to ascertain the extent
to which these waste behave in a manner analogous to similar soils.
5.7  Post-Operational Monitoring
      The type and extent of post-operational monitoring needed for FGC
disposal sites will vary markedly as a function both of disposal operation
and of intended end use of the land.  For example, regulations governing
both disposal of hazardous wastes and coal mining operations may impose
quite different monitoring requirements.
      Leaching of potentially harmful substances from the wastes into
groundwater is expected to be a major long-term impact for any site which
is not covered or otherwise rendered impervious to generation and perco-
lation of leachate.  Because of the relatively long time scale during which
such leaching occurs, post-closure monitoring of groundwater in close
proximity to the site for an extended period will be necessary in order
to detect such effects.  The proposed regulations governing disposal of
hazardous wastes [80] recognize this problem, in part, by requiring that
a post-closure monitoring program be maintained for a period of up to 20
years at the same level (frequency and analytical requirements) as was
employed during active operations.  The proposed surface mining regulations
[77], which do not address FGC wastes specifically, indicate that a
monitoring program, acceptable to the regulatory authority, must be main-
tained until the groundwater recharge capacity and quality has returned
to levels stated in the permit.  No limit is placed on this effort.
      If disposal operations have resulted in potential disturbance to
living species in the area, and these were included in predisposal base-
line assessments, both for disposal in the ocean and in mines, then some
form of biological monitoring would be required after operations had
ceased in order to determine that the area was returned to any level of
"life-support" required by the regulations.
      If post-disposal land use differs from the original use, as for
example, diversion to alternative agricultural purposes, then a redefini-
tion of monitoring requirements to include biological samples, for example,
would likely be required.   Such changes would have to be dealt with on
a case-by-case basis.

                                  5-16

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      The technical details  of such post-operational  monitoring  activities
would likely resemble those  utilized during operations.   It would be
expected that accumulation and evaluation of the operational  monitoring
data might allow selection of key indicator parameters  or species for
post-operational monitoring.
5.8  Data Gaps and Future Research Needs
      FGC waste disposal practices will be subject to monitoring to the
extent required by environmental regulations.  As such, the principal
impetus for monitoring is regulatory, and thus the needs are best described
against the perspective of regulatory requirements.
      Broadly speaking, biological testing and monitoring is assuming
increasing  importance in assessing the real environmental impacts on
disposal sites, and  for providing  guidance on long-term  genetic  and toxic
effects.  At  this  time, research support  is needed for the development of
a  broader base  of  improved biological tests which can be applied to samples
obtained from laboratory  or field  monitoring studies.  Also  of high pri-
ority  is the  need  to establish  appropriate and  acceptable protocols  for
the  predictive  testing  of solid wastes.   Lesser priorities  concern the
need to  support R&D  field studies  for  testing and improving  monitoring
tests.

      To  date, most monitoring data gathered  has been derived from
  chemical  rather  than biological  tests.   As  pointed  out  in Section 5,
  biological and bioassay  tests are becoming increasingly important for
  assessing the  real  impact  (as opposed to inferential impact based on
  chemical  tests alone)  on the ecology  at the disposal site itself, as
  well as for providing  some guidance as to long-term genetic and toxic
  effects of wastes proposed for disposal.  Both of these areas  are
  extremely important to the acceptability and eventual disposition of FGC
  wastes.  In each of the technical areas discussed below, the needs
  related to biological testing are of  high priority.  The technical
  areas are:
                                     5-17

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•  Indicators and Measurement Parameters - Selection of appropriate
   parameters and species for monitoring is the key element in any
   monitoring program.  An understanding of the potentially
   hazardous characteristics of FGC wastes allow selection of
   candidate organisms for controlled testing.  This activity is
   closely coupled to improvements in methodology.
•  Measurement Methodology - Methods for carrying out biological
   tests for acute and chronic toxic and accumulation effects and
   for detecting genetic effects are now under active development
   in connection with many EPA programs in water pollution.  These
   efforts should be supported in order to bring the state of the art
   in biological testing up to the level of chemical testing, in
   terms of applicability, sensitivity, specificity and repeatability.
•  Sampling Methodology - The ability to obtain representative
   control and experimental samples, whether of groundwater or of
   species within the localized ecosystem, is essential to carrying
   out valid baseline and trend assessments.  The major problem of
   predicting local groundwater flow patterns in order to plan and
   implement an effective groundwater sampling program, plagues FGC
   waste disposal in the same way as other solid waste disposal
   programs.  Additional effort on improved methods for predicting
   and tracing groundwater flow is warranted now because of the
   rapidly expanding programs related to RCRA.
•  Field R & D Programs - Additional support to ongoing and upcoming
   field monitoring test programs should be considered.  It is
   especially important to include tests of appropriate biological
   monitoring systems in order to provide opportunities for
   correlation of chemical and biological data under controlled
   field conditions.   In addition, in-situ tests of physical
   properties of the emplaced FGC wastes should be considered at
   a controlled field site.  Tests of the variation of strength,
  density and saturation as they vary with  depth  of overburden  and
  with  time would be  extremely valuable, not  only for  the
  correlation with laboratory tests, but also as  indications  of
  the utility of such measurement for monitoring  stability.
                              5-18

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Relationship With Other Monitoring Programs - Recent publications
have pointed up the complex interrelationships of the multitude
of environmental monitoring programs presently conducted by
various Federal agencies [98,99],  There is increasing need for
and emphasis on obtaining valid correlations among independent
systems through increased implementation of quality assurance
programs, and on avoiding excessive duplication of efforts.  The
EPA FGC waste disposal activities and programs are at the
interfaces between a number of Federal agencies and program
areas, and, hence, may afford the opportunity to provide some
of the needed correlative activity.
Development of suitable and acceptable protocols for pretreatment
and extraction steps for predictive tests  of solid wastes  is of
high priority as discussed in Section 5 of this volume.  Such
procedures are essential for testing and qualifying FGC wastes
in all forms (stabilized and unstabilized)  under proposed  RCRA
regulations.
                              5-19

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6.0  REVIEW OF DISPOSAL ECONOMICS
6.1  Introduction
     The economics of FGC waste disposal are quickly becoming one  of  the
most important factors in the implementation of particulate  control and
FGD systems.  Studies of FGC process technology and evaluations  of
specific FGC process applications  now routinely incorporate  analyses  of
associated waste processing and disposal costs.  With the increasing
importance of waste disposal and the growing emphasis on environmentally
sound waste disposal practices, a number of conceptual design and cost
studies have also been undertaken sponsored by governmental agencies  and
private organizations, notably the EPA and EPRI.  These studies have  been
basically of two types:
     •  First, generalized costing to develop comparative economics for
        various waste disposal options, including current practices and
        potential alternatives.  Such studies have been performed by
        TVA  [23,27,102,103,104], Aerospace  [37,105-109], Michael Baker
        Associates  [9] and ADL  [29].  These have focused on  FGD wastes,
        including stabilized wastes.  Fly ash waste disposal has been
        studied by NUS  [HO] for the Utilities Water Act Group  (WAG).
     •  Second, economic  impact analyses  to estimate the effects  of
        various FGD waste disposal  regulatory  scenarios  on the  utility
        industry.  Two impact studies have  recently been performed by
        Radian  [111]  and  SCS Engineers  [112].   Reports on both  of  these
        studies are  now  in draft form.  Additional  studies have been under-
        taken by DOE regarding  the  possible impact  of RCRA on waste disposal
        costs.
 In addition,  site-specific and  system-specific studies have  been  performed
 by a number of  utilities,  engineering  firms and other consulting  organiza-
 tions.  However,  this assessment  of the economics  of waste  disposal  is
 based  only on the generic studies mentioned above.
 6.2  Generalized Waste Disposal Cost Studies
 6.2.1   Description of Studies
 6.2.1.1  Overview
      Table 6.1 summarizes the general scope and cost bases for the
 generalized cost studies performed by TVA, Aerospace, Michael Baker
                                    6-1

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                                                                    Table 6.1

                            Summary  of General  Conceptualized Cost  Studies  for the FGC Waste Disposal
Contractor
T»A

Aeroepece

Michael laker
ADL
True of
Com.
Sponeor Hlsh S
DA Uaeetone

EPA Liaeetone

XPKI Llae
EPA LJ»e
Scrubber Mode of Operation 1
Forced SO, Dry Wet
Oxidation SO, Only + AaS Landfill Pond
Llaeatone / / / /

Liawtone / (/) / /

-
/
tteooeel Optlone Coneldered
Surface Underground Ocean
Mine Mine
/



-
/ / J

Ho. Caeaa
150*

-30°

4
16
&aae Tear
1979/80

1976.77

1976
1977
Kafarence*
23, 27, 102, 103,
104
37, 105, 106. 107
108. 109
9
29
            ms
                         OKAC
                                                      Fly Alb
                                                      Only
I
10
  Four caaaa lacluda llae •crabbin|.

b Included only for forced oxidation.

c MriMX of cuei atudied varies ulth report.
                                                                                                                            1974
            Source: Arthor*D. Little. Inc.

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Associates, and Arthur D.  Little.   Table 6.2  gives  the  basic  design  and
operating assumptions for  each of  these studies.  Where the  studies  are
still ongoing, the base years for  the most recently published cost esti-
mates are shown.
     Unfortunately, the design and operating assumptions in  these economics
studies as well as the battery limits for the disposal systems differ.   Also,
costs are generally presented in lump sum fcrm covering the  entire waste
processing and disposal facilities.  Hence, direct comparisons of cost
estimates are difficult at best.  In this regard, efforts are now under
way to develop a standard cost basis for future cost analyses of FGC
systems and disposal operations prepared by EPA contractors.
     In developing any generalized costs for waste disposal,  it  is also
important  to  recognize the fact that  it  is frequently  difficult  to  totally
divorce  the waste  disposal system from the scrubber.   This  is particularly
true when  comparing  systems  with  different types of  ash collection  or
scrubber technology  (e.g., forced oxidation),  and  it may be equally
important  when developing the design basis for the waste processing
facilities.   In most cases,  waste processing will  be coupled directly  to
FGC scrubbers or thickeners, and  the waste processing plant must be
capable  of handling  the short-term sustained peak  loads expected for the
 FGC system itself, especially with regard to variations in  coal sulfur
 and ash content.  Such overdesign needs to be factored into either  the
 capacity of the equipment itself  and/or provision for a buffer between the
 FGC system and parts of the waste processing plant (such as interim storage
 of filter cake and ash).   It is best, therefore, to evaluate waste  dis-
 posal in the context of total FGC system costs rather than independently.
       In addition  to the  generic  and  generalized cost  studies, cost  data
  is now  beginning  to be published on  full-scale  commercial  disposal opera-
  tions as  new systems come on-line and more  accurate accounting  of  waste
  disposal  costs  is employed.   These cost data will be  reviewed as they
  apply to  each  of  the  disposal methods  discussed.  The EPA  is also  fund-
  ing two disposal  demonstration projects which will  provide  additional
  cost  information—a landfill impoundment  at LG&E's  Cane Run Station and
  a mine  impoundment  at the Baukol Noonan Mine in North Dakota.
                                    6-3

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                                                                                           6.2
                                  Summary  of  Basic Assumptions  for  General  Cost  Studies  -  FGD/FGC  Wastes
                                                                      TVA
              POKER FLAMT
                   Boiler Site (Ho. zvi)
                   Heat Kate  (Btu/kHh)
                   location
                   Service Life (Tr«)
                   Load Factor (X) - First 10 Tre
                                  - Llfatlac A»g.
                                                   Base Case
                                        300
                                                                              Variation*
                                                                                                          Aerospace*
                                                               200 & 1500
                                                    • 9,000 •
                                                  • Mldveetern
30
SO
48
                                                               IS, 20. 25
     1,000
 9,000 • 9,300

       30

       50
                                                                                                                                         Michael taker
2 x 500
10,000
Eastern
  30
  75
                                                                                                                                                                     ADt
     500
(0.85 Ib Coal/kHh)
    Eastern
      30
      80
 I
•tr-
COAL FIOFEKTIES
     Sulfur Content  (X)
     Aah Content (X)
     Beating Value (Btu/lb)

SOBBBBX ST8TEM DESIGB
     Alkali
                   Node of Operation

                   Alkali StolchloMtry
                                                      3.5
                                                       16
                       2.0 a 5.0
                        12 t 20
                                                                   10.500 •
                                     	Conventional a Forced Oxidation •
                                     SOj + ash                   SOj Only
                                         (Conventional Uavatone - 1.5
                                         JLinestone Forced Oxidation - 1.1
                                         (Line - 1.1
                                                             • To 1.2 lb/M( Btu •
      3.0
    12 & 14
12,000 e 10,560
                                                   Llnutone
                                       [Conventional for SOj + Ash   1
                                       [Forced Oxidation for SOj Only]
                                       (Conventional Llmsetone - 1.5 t 1.25
                                      lUaMtone Forced Odd. » 1.0 t 1.5

                                                   85X 4 901
  3.5
  15
12.000
                                   S02 Only

                                     1.10
     3.0
      10
                     Conventional
                       802 Only

                         1.10

                         90X
               KOKXSC FACTOU
                    Coat Tear
                    Capital Charge Factor
                    System Battary Limit*
                                                     1979/M
                                      0.164                 0.174, 0.179. 0.194
                                     	 Heat* Procesalnj + Dlapoaal 	
                                                  1976 4 1977
                                                     0.18
                                              Haste Disposal Only
                                      T
                                     0.18
                          Haate Processing + Dlapoaal
                         1977
                         0.17
                  Haaee Disposal Only
               *The bases for costs varied over the course of the 5-year stadias.
        Source:   Arthur  D.  Little,  Inc.

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6.2.1.2  TVA (EGG Wastes)
     The continuing FGC waste disposal cost study being performed by TVA
under contract to EPA has the widest coverage with respect to the number
of different wastes and disposal options considered.   A generalized
computer costing model has been developed similar to that for scrubber
system costing.  To date, over 150 cases have been analyzed.
     Thus far, two reports [23,27]  and at least two papers [102,  103]  have
been published summarizing results  of this work.  The first report [23]
covered the disposal of both stabilized and unstabilized wastes from con-
ventional direct lime and limestone scrubbing systems.  In this initial
analysis a total of 121 variations on system design and operation were in-
cluded.  Four base cases were established for new 500-MW plants burning  high
sulfur coal (3.5% sulfur, 16% ash, and 10,500 Btu/lb heating value) fitted
with direct limestone scrubbing for simultaneous S02 and particulate control.
Each base case involved a different type of disposal:  one for disposal via
wet ponding of unstabilized scrubber discharge,  one  for wet ponding of thick-
ened waste stabilized by Dravo's Synearth  process,  and two for dry
 impoundment of filtered wastes dewatered via the Chemfix and IUCS process.
 Variations on these base cases were costed to evaluate the effects of
 power plant size and age,  coal properties, disposal site distance, scrubber
 process conditions, stabilization  additive rates, mode of waste  transport,
 and types  of pond liners for wet  ponding of unstabilized wastes.   Costs
 were also prepared for dry impoundment of unstabilized waste.
       Capital cost  estimates were  prepared in  1979 and  first-year  operating
  cost  etimates on 1980  dollars.  The  economics are presented  on  an inte-
  grated system basis  (including both  waste processing and disposal)
  starting  at the scrubber battery  limits.   Annual revenue requirements
  for the four base cases range from 0.94 mills/kWh to 2.00 mills/kWh
  compared with scrubber costs of 3.38 mills/kWh.
       In a continuation of this study, TVA has recently completed analyses
  of 32 additional cases involving dry impoundment of ash blended unstabilized
  wastes (scrubber preceded by a high efficiency electrostatic precipitator)
  and combined fly ash and gypsum  from forced  oxidation systems with  simul-
  taneous particulate control.  The draft  of this report  [27]  is now  in

                                    6-5

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review; however, a summary of the results of both this and the initial
study has been published [102].
     This work performed by TVA has involved engineering cost estimates
for generalized conceptual designs, focusing on gross effects of major
parameters on waste processing and disposal economics.  As such, simpli-
fying assumptions were made with regard to the engineering properties of
various different types of wastes and equipment design parameters.  The
properties and equipment design bases are now being reviewed and modified
to more closely reflect variations in different types of wastes, and efforts
are being made to provide cost estimates on a modularized basis to allow addi-
tion and deletion of processing units as appropriate.  And the study is being
extended to include disposal of dewatered wastes in area surface mines.
     The costing model has also been used [104] to evaluate the potential
cost effectiveness of employing the thickener/clarifier combination being
investigated by Auburn University in place of a conventional thickener
or thickener/filter combination for waste dewatering.  The results indicate
that potential cost savings of up to $0.75/dry ton of waste (ash + FGD)
may be realized if target performance is achieved.
6.2.1.3  Aerospace (FGC Wastes)
     In 1974 Aerospace [105] first began developing cost estimates for wet
ponding of unstabilized wastes in lined ponds and dry impoundment of stabil-
ized wastes as a part of its ongoing contract with EPA.  Since then, these
estimates have been revised and additional cost data published {37,106-109]
The latest figures were published in 1978 [113] and reflect second-quarter
1977 dollars.  Costs are based upon a 1000-MW power plant burning moder-
ately high sulfur coal (3.5%) using a lime scrubber for combined S02 and
particulate control.  For ponding, wastes are assumed to be piped directly
from the scrubber to the pond.  A variety of different types of ponds have
been considered, including ponds with natural liners, synthetically-lined
ponds, and a novel approach involving ponding with underdrainage wherein
the percolate is collected and returned to the scrubber.  The purpose of
this latter approach is to improve the density of the settled solids and,
at the same time, control leachate escape.
                                  6-6

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     In 1977 [109]  and 1978 [113],  Aerospace also published cost estimates for
producing wall-board grade gypsum from limestone forced oxidation systems
to compare costs with conventional  limestone scrubber waste disposal.
In this case, a high efficiency electrostatic precipitator was included
ahead of the scrubber for particulate removal.
      Aerospace has  recently begun  investigating,  under  contract  to EPA,
 surface disposal of gypsum.   Costs of  disposal  are being  estimated as  a
 part of this effort.
 6.2.1.4  Michael Baker  Associates  (FGC Wastes)
      Michael Baker  Associates recently completed a study  of the  state
 of  the art  of FGC waste treatment  technology [9]  for EPRI.   As  a part  of
 this study,  cost estimates were prepared  for four cases to compare the cost
 of  disposal of untreated wastes with corresponding stabilized materials.
 One pair of cases compares wet ponding of thickened  wastes (unstabilized vs.
 stabilized via a Dravo-type process) , and  the other  compares dry impoundment
 of  filtered wastes  (unstabilized ash blended vs. stabilized via admixture
 of  ash and lime).   The  basis  for the economics  is two 500-MW boilers  firing
 high sulfur eastern coal (3.5% S)  equipped with high efficiency electro-
 static precipitators for particulate control and conventional direct  lime
 systems for S02 control.  Costs were prepared battery limits at the
 thickener underflow with processing costs based upon vendor quotations
 of  package systems.  While not stated, it is assumed that cost estimates
 are in mid-1977 dollars.  The incremental revenue requirements as first year
 costs for waste stabilization were estimated to be  $1.40/dry ton of waste
 (ash + FGD) for dry impoundments and $4.00/dry ton for wet ponding.
 6.2.1.5  Arthur D.  Little (FGC Wastes)

      As a part of an ongoing study to evaluate the feasibility of ocean
 and mine disposal of FGC wastes, ADL prepared general disposal cost
 estimates for conceptualized systems  [29].  A total of 16  cases were
 evaluated,  six for mine disposal  and  ten  for ocean disposal.  The six  mine
 disposal cases included four  involving dry  impoundment in  surface area  coal
 mines  and two  for  hydraulic  backfilling of  underground coal  mines.  The
 ten  ocean disposal alternatives included  four  on-shelf disposal cases and
                                    6-7

-------
six deep ocean disposal cases.  Both stabilized and unstabilized wastes are
included.  Costs were prepared battery limits at the discharge of the
dewatering or waste processing equipment and are presented in first
quarter 1977 dollars.  Revised cost estimates for the most promising
options are expected to be published in early 1979.
     Also, as a part of this program, a mine disposal demonstration
project for FGC wastes from an alkaline ash scrubbing system is being
conducted.  The scrubber system is at Square Butte Electric Cooperative's
(Minnkota Power) Milton R. Young Station, North Dakota; and the wastes
are being returned to the Baukol Noonan mine.  The cost of the full-scale
disposal operation is being tracked to assess overall mine disposal
economics.
6.2.1.6  NUS Study (Fly Ash)
     A study was performed in 1975 by NUS for the Utility Water Act Group
(UWAG) to make a comparative economic evaluation of the costs associated
with a dry fly ash disposal system versus a wet system for new power
plants [110].  While actual costs are highly site- and system-specific,
a number of baseline assumptions were made to facilitate generic com-
parisons.  The design basis was a 35-year plant life with a lifetime
total fly ash production of 8.35 x 10^ metric tons.  The wet pond would
require a total area of 1.35 square kilometers (340 acres) and would
consist of an excavated, unlined area surrounded by 9.1-meter (30-foot)
containment dikes with a 5/1 slope.  The dry impoundment area was esti-
mated to require a cleared area of 0.95 square kilometers (240 acres)
where ash would be deposited to a depth of 9.1 meters (30 feet) and
contained by dikes with a 5/1 slope.  The cover for the wet pond would
be approximately 1.5 meters (5 feet) of water; the dry impoundment would
be covered by 1 meter of compacted earth.  In this regard, the design/cost
basis was a geographic location where annual precipitation roughly equalled
evaporation, a rare occurrence for most disposal sites.  Thus, only the
dry impoundment area includes a rainfall treatment facility.
     Based upon these assumptions and using the available data, the capital
cost for the wet pond was estimated to be $22.2 million compared with
                                  6-8

-------
$7.8 million for the dry impoundment (1979 dollars - escalated from 1974
costs @ 8%/yr); both included land cost at $3000/acre ($750,000/square
kilometer).   The annual operating cost for the dry system was also esti-
mated to be significantly less expensive than the wet system—cost of
$18.00 for wet ponding per ton versus $9.50 for dry disposal (1979
dollars).  A key element in the cost of disposal is that associated
with run-off treatment.  However, many site-specific factors could
change this and other aspects of ash disposal costs.
6.2.2  Disposal Cost Estimates for FGD/FGC Wastes
6.2.2.1  Land Disposal
     Three of the four studies discussed  above have  dealt exclusively
with land disposal of FGC wastes; the  fourth, performed by  Arthur  D.
Little, has covered both land  (mine)  and  ocean disposal.  All  of  these
studies  address applications  of  FGC  systems  to relatively high sulfur
coals  in eastern or midwestern locations.  However,  there are  signifi-
cant differences in the bases  and assumptions for the estimates which
make direct comparison  of  costs  from different studies difficult.   The
most important  of these are  as follows:
     •  Battery limits  vary  from waste disposal  facilities  only to
         complete systems  including  all waste processing starting at
         the scrubber  discharge.
      •  In  most cases,  capital and  operating costs are presented on
         a lump sum basis  for the entire system rather than  broken down
         into  modular  units.
      •  Wide  variations in plant load factors (from 48.5% to 80%)
         skew costs to the high side for the low load cases.
      •  Design assumptions relative to waste physical properties and
         the depth of wastes in ponds and landfills vary significantly.
         This can affect land requirements and disposal costs by 30%
         or more.
      •  The assumptions regarding incorporation of  fly  ash in the dis-
         posal of FGD where  fly  ash  is separately collected vary  in
         different studies.

                                    6-9

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     •  Different approaches have been used for incorporating land costs
        in the disposal estimates.  In some cases, the cost of land is
        included in depreciable capital.
     •  The handling of site monitoring and land reclamation usually
        differ markedly in generalized cost studies; however, for the
        most part those considered here do not include these costs.

     The effect of these differences in system design and operating
assumptions can create a wide range of disposal costs for any given mode
of disposal.  Direct comparisons of costs from different studies, there-
fore, requires a complete understanding of the bases upon which the costs
were prepared.
     The problem of handling land costs for dry impoundment and wet ponding
systems can be difficult.  Consideration must be given to the type of
disposal operation and the potential land use following retirement of the
disposal area as well as the purchased price of the land.  In some cases,
it may be appropriate to include land costs as a part of depreciable
capital, particularly for wet ponding of unstabilized wastes.  On the other
hand, land values may actually appreciate for some dry impoundment areas,
depending upon locale, type of wastes impounded, and the manner of final
reclamation.
Wet Ponding
     The two most comprehensive studies of the cost of wet ponding of
FGC wastes have been performed by TVA and Aerospace.  In the TVA study
a total of 68 different cases for stabilized and unstabilized  wastes
were evaluated covering variations in plant size and age, coal composi-
tion, waste processing, scrubber operation, distance to disposal sites,
and pond lining requirements.  Table 6.3 summarizes the capital and
operating cost estimates for the 25 cases representing waste disposal
systems on new boilers equipped with conventional direct limestone
scrubbing for combined particulate and SC>2 removal.  The base case for
these costs involves direct discharge of scrubber slurry to an onsite
clay-lined pond (1 mile from the plant).  For onsite disposal of unstabilized
wastes TVA's estimates of capital costs range from $24.3/kW to $49.0/kW
with corresponding annual operating costs oj. :5.55/dry ton to $12.12/dry
                                  6-10

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                                                Table  6.3
                      Summary  of  TVA  Cost  Estimates for  Wet  Ponding
Basis:  1979/1980 Costs
       500-MW New Boiler
       3.51 Sulfur,  16* Ash
       Conventional  Limestone Scrubbing
       Simultaneous  SO, and Fartlculate Removal
       Scrubber Discharge Directly to Fond
       FGD Scrubber  Costs - Capital - $72.74/kWh
                         - Operating • 3.38 milla/kWh
                                                                                       Operating Costs
                                   Capital  Costs ($/kW)   Operating Costs (mills/kWh)c      ($/dry ton)c
                                                                                    UnstabllUed Stabilized
Variation Comparisons
Plant Size (Mew)
ZOO MW
| 500 MJT[
1500 MW
Sulfur Content
2.01
| 3.5Z |
5.0X
Pumping Distance
| 1 mile"]
5 mile
10 mile
Thickening (35X Solida)
1 mile
5 mile
10 mile
Land Availability
Optimal Cv20-ft depth)
75Z of Optimal
301 of Optimal
Settled Density
40Z Solids
SOZ Solids |
60Z Solids
Lining Requirement
Unllned
| Clay Lined |
unstabillaed

49.0
34.4
24.3

26.8
34.4
41.3

34.4
53.7
74.8

37.0
49.8
62.9

34.4
36.0
45.4

40.1
34.4
30.4

28.8
34.4
Synthetic Lined ($2.50/yd*) 46.1
Synthetic Lined ($4.SO/yd2) 33.4
Stabilized Uastabilized

69.7 1.44
48.2 0.94
32.2 0.64

38.5 0.75
48.2 0.94
57.0 1.10

48.2 0.94
62.0 1.58
75.5 2.14

1.06
1.48
	 1.84

48.2 0.94
62.1 0.96
75.4 1.18

	 1.07
0.94
	 0.84

	 0.79
0.94
	 1.21
	 1.40
Stabilized

2.60
1.91
1.36

1.52
1.91
2.29

1.91
2.32
2.67

	
	
	

1.91
2.25
2.60

	
	
-—

	
	
	
	
8 1 1 represents base conditions.
                                                                                      12.12
                                                                                       8.08
                                                                                       5.55
                                                                                       9.37
                                                                                       8.08
                                                                                       7.35
                                                                                       8.08
                                                                                      13.61
                                                                                      18.48
                                                                                        9.10
                                                                                       12.79
                                                                                       15.89
                                                                                        8.08
                                                                                        8.29
                                                                                       10.15
                                                                                       11.54
                                                                                        8.08
                                                                                        6.05
                                                                                        6.81
                                                                                        8.08
                                                                                       10.47
                                                                                       12.07
20.41
15.32
10.87
17.45
15.32
14.08
 15.32
 18.57
 21.39
 15.32
 18.06
 20.82
 b Stabilized via Draw's Synearth   ptoceat using 7Z Calcilox*
 °Baaed upon 7,000 hra/yr operation at full load.
                                                      6-11

-------
ton.  As would be expected, the most important factors for onsite disposal
are those affecting the pond size and construction requirements—e.g.,
quantity of wastes (sulfur content and plant size), type of lining, and
solids settling properties.  For example, ponding costs appear to vary
to about the 0.65 capacity factor for plants in the size range of 500 to
1500 MW.  For offsite disposal the cost of slurry pumping becomes signi-
ficant; for distances greater than about two miles, thickening of the
wastes prior to disposal is generally cost-effective.
     The cost of wet ponding of stabilized wastes estimated by TVA is
significantly more than that of unstabilized wastes unless lining require-
ments become excessive.  The basis for these stabilization costs is Dravo's
        ®                      ®                                           /i
Synearth  process using Calcilox  as the additive.  The cost of the Calcilox
is a significant factor in the overall costs.  At the 7% addition rate
assumed here (on total dry weight basis) the cost of the Calcilox
accounts for 15-30% of the total annual operating costs.
     Analogous costs for wet ponding of unstabilized wastes have been
prepared by Aerospace.  The basis and assumptions for these costs are
generally similar to those of a number of cases considered by TVA.  In
1978 Aerospace [113] published estimates of disposal costs for wet pond-
ing ash and FGD wastes from model direct limestone scrubbing systems on
1000-MW and 500-MW boilers firing high sulfur coal.  The annual average
cost for codisposal of thickened wastes in a clay-lined pond, at a dis-
tance of one mile, were estimated to be $4.89/dry ton and $6.07/dry ton
for 1000-MW and 500-KW systems, respectively.  For disposal in a PVC-lined
pond (20-mil thickness) annual costs were estimated to be $7.25/dry ton
and $9.01/dry ton for the 1000-MW and 5.00-MW cases, respectively.  At
first inspection, these costs appear reasonably close to those estimated
by TVA (see Table 6.3); however, there are important differences which
must be reconciled before a direct comparison can be made.  Table 6.4
compares the basis for the Aerospace and TVA estimates for the 500-MW
cases.  The most important differences affecting the cost estimates are
as follows:
     •  Base Year - Aerospace's costs are based in mid-1977 dollars,
        while TVA's costs were prepared in mid-1980 dollars.
                                   6-12

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                                                Table 6.4

                 Comparison of Generalized Costs for Wet  Ponding Unstabilized FGC Wastes
                          Basis:  Plant Size
                                  FGC System
              - 500 MW
              - Conventional Limestone Scrubbing for
                S02 and Particulate On-Site, Clay-Lined
                Ponds
Battery Limits - Thickener Underflow
 Design  and  Operating Assumptions
   Coal  Properties = %  S
                   % Ash
   S02 Removal Efficiency  (%)
   Limestone Utilization (%)
   Annual Operating Hours—30-yr. Avg.
   Annual Waste Production—30-yr. Avg.
    (dry tons)
   Waste Transport: Distance (miles)
                   Pipeline Location
   Pond Construction: Site Preparation
                     Lining Depth (inches)
                     Waste Depth (feet)
  Pond Land Requirement (acres)
Capital Cost Factors
  Base Year
  Indirect  Costs Included  Fixed Investment
    Engineering  and Fees
    Field Expense
    Contingency
  Other  Indirect Costs  in  Total Capital
    Interest During  Construction
    Startup  Allowance
    Land
                                               Aerospace
                  3.5
                 14
                 90
                 80
               4380
             Surface
             Minimal
                18
                30
               ~310

             mid 1977


             Not Included
             $5000/acre
                                             TVA
            3.1
           16
           78.7
           67
         4250

      246,500
            1
       Underground
       Minimal
           12
       21 and ~28
      407 and 305


      mid 1980

 Varies  with  Alternative ~20%
 of Direct  Costs
"20% of  (Direct + Eng. + Fees + Expenses)

 12% of  Fixed  Plant
 10% of  (Fixed Plant Less Pond  Const.)
 $3500/acre

-------
     •  Handling of Land Costs - Aerospace's cost estimates include
        land at $5,000/acre as a part of total depreciable capital,
        while land costs are not depreciated in TVA's estimates.
     •  Pond Design - Aerospace's costs are based upon a 30-foot deep
        pond with and 18-inch clay liner, while TVA's costs are for
        20-foot deep ponds (except for the variations on optimal space
        which include a 30-foot deep alternative) with a 12-inch clay
        liner.
     •  Waste Quantity - While the annual average waste quanitites of
        total ash and FGD wastes over the life of the plant are
        roughly 356,000 tons in both studies, the waste quantities used
        in the dollars/ton estimates differ—Aerospace's costs are based
        upon the 30-year average while TVA's costs are based upon the
        annual average for the first ten years of operation (for the
        costs shown in Table 6.3).
     •  Processing Equipment - TVA's estimates include the waste dewater-
        ing equipment (thickener, surge tank, and associated pumps and
        piping) as well as the pipeline and pond, while Aerospace's costs
        include only the pipeline and pond.
     •  Pipeline - Aerospace's costs are based upon pipeline built above
        ground while TVA has assumed an underground line.
     •  Indirect Capital Costs - TVA's estimates include all engineering,
        owner's expenses and contingency while Aerospace's estimate
        include no engineering or owner's expenses.
     In order to provide a better comparison of the Aerospace and TVA
costs,  an attempt has been made to adjust the estimates for the 500-MW,
clay-lined pond case by putting them on a reasonably consistent basis.
Specifically, five adjustments have been made:
     •   Conversion of costs to 1978 dollars using an escalation factor
        of 8% over the period 1977 through 1980;
     •   Reduction in the load factor for TVA's annual costs shown in
        Table 6.2  from 80% to the annual 30-year average of 48%, there-
        by reducing the quantity of solids handled and some direct
        operating costs (principally power);
                                  6-14

-------
     •   Extraction  of  land  costs  from  the  Aerospace depreciable capital;
     •   Extraction  of  the dewatering equipment  and all associated
        indirect  costs from TVA's  depreciable capital; and
     •   Inclusion of engineering,  interest during construction,
        and starting in Aerospace's depreciable capital  by  increasing
        the existing capital (excluding land) by 25%.
     These adjusted capital investment anu operating  costs  resulting
from these modifications are as follows:
                                          TVA      Aerospace
     Total Capital  Investment ($/kW)        28          20
     Annual Average Operating Cost
     ($/dry ton)                           11.00       6.50
     On this adjusted  basis, the capital and operating costs differ
significantly.  The biggest part of the difference in operating costs
is due to the variation in capital costs.
     It is interesting to compare these cost estimates with the estimate
prepared by NUS for disposing of fly ash  alone  in an unlined pond.  For
an annual production  rate of 262,800 tons of ash per year  (compared with
TVA's 246,500 tons per year annual average), NUS estimated about  $16.50
per  ton in 1978 dollars (converted from 1979 @  8% per year).
Dry  Disposal
     In TVA's economic study of  FGC waste disposal,  four different  types
of wastes  from direct lime  and limestone  scrubbing systems have been
evaluated  for dry  impoundment: unstabilized wastes from simultaneous S0?
and  particulate  removal; wastes  from  S02  removal blended with  fly ash; sta-
bilized wastes;  and gypsum wastes from forced  oxidation.  Of these, only
 the  last  three  can be considered to be realistic options for  dry  impound-
ment.   Unstabilized wastes  from conventional direct  lime or limestone
 scrubbing systems  are not  easily dewatered  to  the  point where  they can
 be handled, placed,  and compacted as  a stable  fill material.
      Table 6.5   shows cost estimates prepared  by  TVA for the processing
 and disposal of ash blended wastes,  stabilized wastes,  and gypsum produced
 by  forced oxidation.   Since each of these involves a different type of
                                   6-15

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                                                           Table  6.5

                      Summary  of  TVA Estimates  for Dry  Impoundment Disposal Systems
Basis:  Limestone Scrubbing
       500-t* K«v Botl.r
       3.5! S Coal, 16Z Ash
variation
Comparisons*
FCC SYSTEM (300MO
DISPOSAL SYSTEMS
Sulfur Content6
2.01
5. OX
Disposal Distance
|l mile!
5 mile
10 mile
Additive Feed
3 wtZ
| 4 wtt"]
5 wtZ
Ash Blendlngb
92.0

14.7
17.2
19.1

17.2
17.9
18.7

—
—
—
Stabilisation
72.7

18.7
21.4
23.9

21.4
22.8
23.8

20.6
21.4
21.5
Gypsum*1
77.3

9.6
10.8
11.8

10.8
11.5
12.0

—
—
—
Ash Blending
3.94

0.91
1.07
1.20

1.07
1.25
1.39

—
—
—
Stabilization
3.38

1.33
1.51
1.77

1.51
1.85
2.14

1.43
1.51
1.57
Gypsum
3.67

0.77
0.89
0.93

0.89
1.06
1.22

—
—
—
Ash Blending
—

11.26
9.20
7.88

9.20
10.81
11.96

—
—
—
Stabilisation

15.57
12.55
11.29

12.55
15.40
17.73

11.96
12.55
12.95
Cypsm

9.74
7.86
6.43

7.86
9.37
10.80

—
—
—
 * I       I  Indicates base CAM condition.

  FCC system for ash binding includes high efficiency electrostatic preclpitator.

  treatment Involves lime addition to nixed ash and FGD vastes.

  Limestone forced oxidation system for simultaneous SOj and partlculate control-

  Slight adjustments In FGD costs are required to account for changes in inlet S<>2  and S<>2.
  removal efficiency.

-------
scrubber operation, the costs for waste processing and disposal cannot
be evaluated out of the context of the entire FGC system.   Hence, TVA
cost estimates for the particulate control and SCL scrubbing systems are
also shown in Table 6.5.  For the ash blending option, the cost shown for
the FGC system, $92/kW, includes an electrostatic precipitator for dry ash
collection.  For the stabilization option, the FGC system involves simul-
taneous S02 and particulate control; consequently, the cost for gas scrubbing
is considerably lower, $72.7/kW.  The FGC system for producing gypsum also
involves simultaneous SC>2 and particulate control; however, the additional
cost of forced oxidation of the scrubbing liquor increases the capital
investment to $77.3/kW.  According  to these estimates, the base case
annual costs  for these three options  (@  3.5%  sulfur)  rank as  follows:
     Forced oxidation  (gypsum)        -  4.56 mills/kWh
     Stabilization via  lime  addition -  4.89 mills/kWh
     Ash blending                     -  5.01 mills/kWh
The  relative  rankings are a  result  of the assumptions regarding particulate
control requirements  and the superior dewatering properties of gypsum.
Inclusion  of  electrostatic precipitators for  all cases would, of course,
change  these  rankings.  It is also  possible that dry  ash  collection and
blending would  be  required  for wastes   from  conventional direct scrubbing
systems in high sulfur coal  applications.
     In a  study of stabilization technology for EPRI, Michael Baker Associates
compared costs for conceptualized dry impoundment  disposal  systems  for ash
blending versus stabilization.  The basis  for these estimates was a 1000-MW
power plant  (two 500-MW boilers)  firing  3.5%  sulfur,  15%  ash  coal,  and
equipped with a high  efficiency electrostatic precipitator  followed by  a
conventional  lime  scrubbing  system.    Based upon vendor quotations  for
turnkey waste processing facilities,  estimated capital costs  were  $8.8/kW
 for  ash blending  and  $9.0/kW for  stabilization.   Corresponding first-year
annual  revenue  requirements  were  $6.90/dry ton of total wastes for ash
blending  and $7.70/dry ton  for stabilization; the difference being almost
 entirely  due to the cost of lime.   Stabilization costs were based upon  lime
 addition  at  a rate equivalent  to 2% of the dry weight of FGD wastes and
                                    6-17

-------
fly ash.  Increasing lime addition by 1% would increase annual revenue
requirements for stabilization by about $0.50/dry ton of total wastes.
At a 3% addition rate, then, the cost of treatment would run about 20%
higher than ash blending alone.
    This differential is slightly lower than other estimates reported in
the literature.  Research Cottrell, Inc., for example, estimates the
cost of treatment of wastes from a 500-MW plant firing 3% sulfur coal
to be 30-35% higher than ash blending [114].
Mine Disposal
    Estimates of mine disposal costs have been prepared for conceptualized
systems by Arthur D. Little, Inc., as a part of its feasibility study for
EPA [29].  Both surface mine and underground mine options were considered.
Table 6.6 summarizes the cost estimates for the most promising of the
options evaluated.
     The costs were prepared for wastes from a 500-MW boiler firing 3%
sulfur, 10% ash coal equipped with a high efficiency electrostatic pre-
cipitator followed by a conventional lime scrubbing system.  The wastes
were assumed to be filtered and treated or simply blended with ash to
produce a material that could be easily handled and transported.  The
cost of the disposal systems shown in Table 6.7, though, does not include
any waste processing.  The battery limits begin at the tail end of the
processing facility and include:  waste transfer, storage, and loading
at the plant; transport to the mine; and unloading, storage/transport,
and placement at the mine.  Two cases are shown for surface mine disposal;
one for onsite disposal (mine-mouth power plant), and one for offsite
disposal (200-mile rail haul).  In both cases, wastes are dumped in the
mined-out pit prior to overburden replacement.  Dedicated trucks were
assumed for hauling and placement; for rail haul, a charge of lc/ton-mile
for use of the coal train returning to the mine.  For underground mine
disposal, only onsite disposal is shown.  Thickened sludge (treated or
untreated) would be piped to the mine area and pumped down through bore-
holes into open rooms partitioned from the active mining areas with
bulkheads.
     The costs for onsite (mine-mouth disposal) are estimated to be
$3.00-3.50/dry ton, and $6.50/dry ton for offsite disposal in a surface

                                  6-18

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                                               Table 6.6

                                 Summary of Mine Disposal of FGC Wastes
                                      Basis:  500-MW Plant
                                              3% Sulfur, 10% Ash Coal
                                              Annual Load Factor - 80%
                                              90% S02 Control
                                              1977 Dollars
                                                             Capital Cost
Mine Type
Surface (Truck Dump)

Location
Onsite
Offsite
Transport
Truck
Rail
($/kW)
3.7
3.9
                                                  Operating Costs
                                                                              (mills/kWh)
                                                                                 0.35
                                                                                 0.70£
                                                            ($/dry ton)

                                                                3.30

                                                                6.50
Underground  (Hydraulic  Fill)
Onsite
Pipeline
2.1
0.35
3.20
1Rail haul costs assumed to be $2.00/short  (wet) ton = lc/ton-mile.
Source:  [29]

-------
                                             Table  6.7

                Summary of Preliminary Cost Estimates for Ocean Disposal of FGC Wastes
                                   (Concentrated Bottom-Dump Disposal)
                                                                       Operating Costs



1
ro
G>

Ocean Locale
Contentintal Shelf
(25 nmi)

Deep Ocean
(100 nmi)

Waste Type3
Soil-likeb

Block-like
Soil-like0
Block-like
i.ai>-L(.a.L (..OBI.
($/kW)
3.2-3.7

6.9-7.4
5.3-7.25

(mills /kWh)
0.4-0.5

0.6-0.7
0.65-0.85
0.85-1.05
($/dry ton)
4.15-4.90

6.35-7.10
6.85-8.90
9.05-11.10
 Soil-like:  Mixed fly ash and FGD waste or stabilized FGD wastes.
 Block-like:  Stabilized waste (assumed to be reclaimed from curing ponds)


 Not considered promising at this time.

 May only be promising for sulfate-rich wastes.
Source:  [29]

-------
mine.  The difference is principally due  to the cost  of  rail  haul  and
the additional storage/transfer requirements for an offsite mine.
     As in the case of wet ponding, an attempt was made  to compare these
cost estimates with those prepared by TVA for dry impoundment by adjust-
ing  the assumptions to a consistent basis.  This principally involved
converting the costs to a constant  1978 dollar basis and deleting
waste processing facilities and costs from the TVA estimates.  The
adjusted mine disposal costs of roughly $3.50/dry ton compared quite closely
with the adjusted TVA estimates of $3.50-4.00/dry ton for impoundment of
ash  blended and stabilized waste.  It would be expected that mine disposal
would be less expensive than impoundment  since in most cases compaction
would not be required nor would additional  land  costs or  land reclama-
 tion be required.
     TVA, as a part  of  its ongoing evaluation of FGC wastes  disposal
 costs  for the EPA, is now preparing generalized  cost estimates  for  sur-
 face mine disposal for  comparison with other dry impoundment options.
 6.2.2.2   Ocean Disposal Costs
      Ocean  disposal  is  still in the research stage.   Costs for such
 operations  will  be highly dependent on the type of wastes which can be
 discharged, if any,  and the  measures required to mitigate or avoid
 potential environmental impacts.
      Based upon a preliminary feasibility study performed by Arthur D.
 Little,  Inc. [29], costs were prepared for conceptualized systems
 representing likely disposal options.  Table  6.7 summarizes the cost
 estimates for both deep ocean (100 nautical miles offshore)  and shallow
 ocean (25 nautical miles offshore on the continental shelf)  disposal on
 the East Coast.   The ranges of costs shown cover the use of tug/barge
 combinations and self-propelled  ships.   For near-shore disposal, self-
 propelled ships are slightly less expensive  than tug/barge  systems
  (assuming a 25-nmi one-way distance), but self-propelled  ships are  con-
  siderably  cheaper than tug/barge combinations  for deep ocean disposal.
  As  in the  case of the mine disposal  systems,  the  costs shown in  Table 6.7
  do  not include any waste processing  costs;  however, the  costs  of recovering
  stabilized wastes from 30-day curing ponds  (to  obtain  a  brick-like material)
  are included.
                                    6-21

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     It is apparent  from these preliminary cost estimates that if stabil-
ization is required  for any type of ocean disposal, then the costs of
deep ocean disposal  may be prohibitive because of the transport distances
involved.  The disposal of wastes on the continental shelf, on the other
hand, may be cheaper than returning wastes to an offsite mine.
     Cost estimates  for ocean disposal are now being updated by Arthur D.
Little, Inc. for the most promising options.  The State University of
New York at Stoney Brook is also now conducting a study of reef construc-
tion using stabilized blocks of FGC wastes under joint industry/government
funding.  Additional cost data on ocean disposal are expected to result
from this work.
6.3  Economic (Cost) Impact Studies
     Two general economic (cost)  impact analyses of FGD waste disposal
regulations on the utility industry have been undertaken to date.   One has
been performed by Radian for EPA's Industrial Environmental Research Labora-
tory [111] and the other has been performed by SCS Engineers for EPA's Municipal
Environmental Research Laboratory [112].  Although final reports are not
available for either study, preliminary results have been issued in
draft form.  Because of differences in the purpose, scope,  and bases
for these two studies,  the results are not expected to be directly
comparable; however, they should give a first approximation of the effects
of pending or potential future waste disposal regulations on the incre-
mental cost of FGC waste disposal to the utility industry.
6.3.1  Radian Study
     The Radian study focuses on the economic impact of RCRA under the
conditions that FGC wastes (both ash and FGD wastes) are considered non-
hazardous [111].   The economic evaluation is based on hypothetical enforce-
ment scenarios using a model plant approach involving "typical" 1000-MW
coal-fired plants.  Eight different disposal methods for fly ash,  FGD wastes,
and combined FGC wastes were selected as representative of existing and
future disposal practices through 1985.  These are:
     •  Fly ash - ponding and dry landfill,
                                  6-22

-------
     •  Ash-free FGD waste  -  ponding  of  thickened  or  unthickened
        slurries and landfill of  dewatered  waste.,  and
     •  Combined FGC waste  -  ponding  of  thickened  or  unthickened
        slurries and landfill of  dewatered  waste.
Ponding or dry fill of stabilized material  was not considered.
     Cost estimates were then prepared for  each of these options for the
model plant and cost factors  developed to  pply these costs to the entire
generating capacity assumed to be affected.
     The potential impact of RCRA on existing plants was assumed to be
limited to those beginning operation after 1970.  It was assumed that
one-half of the existing capacity starting up after  1976 would have to
move their disposal sites from a current average of  about 5 kilometers
from the plant to about 16 kilometers (the basis for this assumption is
not provided), and that all would use lined ponds or unlined dry  fills.
For new plants, it again was assumed  that  all disposal  areas would be
either lined  ponds or unlined dry fills, and that all plants would have
to increase the average distance to disposal  sites from the usual 5 kilo-
meters to  about 8 kilometers in  order to protect  groundwaters  (a  shorter
distance  than for existing plants because  increased  concern  in siting
disposal  areas would lead  to better  selections  for newer plants).   The
major effects of RCRA then would be  increased distances to disposal sites
and  the  use of lined ponds and dry  fills.   (No linings  are assumed  to  be
required for  dry  fills  because it  is  assumed that all new fills would  be
located in impermeable  areas or  areas where groundwater quality would  not
be in danger.)
      Based upon these assumptions,  it is estimated that the  increase in
 capital investment for waste disposal due  to compliance with RCRA will
 amount to approximately one billion dollars, or about  36%, through 1985
 (in 1979 dollars).   However, required annual revenue requirements (in
 1979 dollars) would increase only about 5-6% or about 70 million dollars
 per year.  Table 6.8 summarizes these cost estimates.   It should be noted
 that these estimates do not include:  sunk costs associated with moving
 existing disposal sites; costs for recovering wastes or reclaiming exist-
 ing sites due to unacceptable groundwater contamination  (or danger of it);
 or costs  for levees to protect against pond flooding.

                                    6-23

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                                                         Table 6.8

                                           Summary of Estimated Cost of Compliance
                                                     (Mid-1979 Dollars)
ON
I
Existing
  Plants*
  (1970-1978
   Construction)


Planned and
  Future
  Facilities
  (1978-1985)


  Total Costs

  Net Costs
                               	Capital Investment Costs ($)	
                               Estimated Cost      Estimated Current
                               of Compliance       with Predicted
                               with RCRA           Cost - No RCRA
                                  49,075,000
     0
                               3,631,750,000
2,699,650,000
                               3,680,825,000   -     2,699,650,000

                                           981,175,000
                                                                   	Revenue Requirements  ($/yr)	
                                                                   Estimated Cost      Estimated  Current
                                                                   of  Compliance       or Predicted  Cost
                                                                   with  RCRA           No RCRA
   68,725,000
55,350,000
1,202,700,000   -     1,148,140,000
                       1,271,425,000   -     1,203,490,000

                                    67,935,000
          Assuming 50% out of compliance
         Source:   [111]

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6.3.2  SCS Study
     SCS Engineers has evaluated the impact  of  different  degrees  of  severity
of FGD waste disposal regulations on the utility industry [112].  In contrast
to the Radian study,  the SCS analysis does hot  specifically address  RCRA
nor does it include fly ash except where it  is  co-disposed with FGD  wastes.
     Five regulatory scenarios were considered  in the SCS analysis,  as
follows:
     1.  Federal Advisory - State Legislation and Enforcement—
         Simple permitting, stabilization not required and not
         commonly used (no change from current trend in disposal
         practices).
     2.  Federal Advisory - State Legislation and Enforcement—
         Site-specific evaluation with stabilization sometimes
         required  (no urban ponding).
     3.  General Federal Legislation - State Enforcement—Physi-
         cal stabilization  required, no ponding.
     4.  Comprehensive Federal  Legislation  - State Enforcement
         upon Approval—Chemical  stabilization  required  in  urban
         areas.
     5.  Comprehensive Federal  Legislation  and  Enforcement  - No
          State  Involvement—Chemical stabilization universally
          required,  specifications given for the stabilization
          techniques.
      These five regulatory  scenarios were then applied to a set  of  10
 model plants covering three geographical regions,  three  coal types,  and
 urban and rural locations.   Six disposal methods were considered:   unstab-
 ilized wastes  in unlined ponds; unstabilized wastes  in clay-lined  ponds;
 stabilized wastes (Dravo) in unlined ponds; dry landfill of dewatered,
 unstabilized wastes; dry landfill of dewatered, unstabillzed wastes mixed
 with ash; and dry landfill of stabilized wastes (IUCS).  Capital and
 operating costs and annual revenue requirements were then perpared for each
 model plant and disposal option based upon the generalized disposal cost

                                     6-25

-------
estimates prepared by TVA (see Section 6.2), and these were applied to
1980 and 1985 projections of FGD capacity categorized according to the
ten model plants.
     Table  6.9 summarizes the expected average future cost (in 1980 dol-
lars) for FGD waste disposal under each of the regulatory requirements
(scenario No. 1), FGD waste disposal is expected to cost an average of
1.02 mills/kWh for capacity on line in 1980 and 0.76 mills/kWh for the
total capacity on line in 1985; these correspond to projected annual reve-
nue requirements for the on-line capacity of about $2.6 billion and $3.1
billion respectively.  Increasingly more stringent regulations are expected
to add from 0.007 mills/kWh (scenario No. 1) to 0.37 mills/kWh (scenario
No. 5) in 1980; and from 0.008 mills/kWh (scenario No. 1) to 0.56 mills/
kWh (scenario No. 5).  These costs do not include the sunk cost of capi-
tal investments already made under scenario No. 1 but which are no longer
useable under the more stringent regulations.
6.4  Economic Uncertainties
     There are a number of uncertainties concerning FGC waste disposal
that importantly affect overall disposal economics and viability of
certain disposal modes.  Important among these are uncertainties relat-
ing to land use/availability/cost, long-term maintenance of retired dis-
posal sites, and the financial liability/responsibility of disposal sites.
These are not data gaps in the sense that they can be readily resolved
through current studies or R&D efforts; rather, they are social/technical/
economic issues which will require continuing consideration and evaluation.
     The issue of land use, availability, and cost can be relatively complex
and will become more important with the growing implementation of nonrecovery
FGC systems.  One aspect of this issue is directly related to regulations—
i.e., the availability of land that meets all the environmental constraints
of federal and state laws, and, in particular, RCRA.  This can affect not
only plant siting and/or disposal distances but also the type of FGC system
employed and the mode of waste disposal.   There are also many facets to
this issue which fall outside the realm of regulations but which can
directly affect FGC waste disposal economics.  These generally fall under
the category of land-use planning and resource allocation, which impact
                                  6-26

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                                                          Table 6.9


                                    Summary of Regulatory Impacts to  Consumers in Mills/kWh*
I
ro
Location/
Coal Type
Setting
Regulatory
Scenario No.
1
2
3
4
5
Regulatory
Scenario No.
1
2
3
4
5
Western
Urban
Rural
Midwestern No. 1
Urban
Rural
Midwestern No.' 2
Urban
Rural
Eastern No. 1
Urban
Rural
Eastern No. 2
Urban
Rural
Industry
Average
Percent
Increase
Over
Scenario
No. 1
For the Year 1980:
.53
.80
.80
1.00
1.00
.61
.61
.72
.72
1.00
.88
1.08
1.08
1.44
1.44
.93
.93
1.10
1.10
1.44
1.28
1.28
1.28
1.83
1.83
1.30
1.30
1.49
1.49
1.81
1.20
1.20
1.20
1.20
1.20
.57
.57
.88
.88
1.19
1.59
1.59
1.59
1.59
1.59
1.59
1.59
1.59
1.59
1.59
1.017
1.024
1.136
1.190
1.400
	
0.7
11.7
17.1
37.7
For the Year 1985:
.53
.80
.80
1.00
1.00
.55
.55
.64
.64
1.00
.91
1.08
1.08
1.44
1.44
.67
.67
1.08
1.08
1.44
1.28
1.28
1.28
1.83
1.83
1.07
J.07
1.42
1.42
1.81
.78
.96
.96
1.20
1.20
.57
.57
.88
.88
1.19
1.59
1.59
1.59
1.59
1.59
1.59
1.59
1.59
1.59
1.59
.759
.767
.981
1. 026
1. 321
	
1.)
29.7
35.2
74.2
              •All amounts are in present value as of mid-1980.
               Source:   [112]

-------
land valuation and may ultimately constrain the types of wastes disposed
of and the manner of disposal.  While land-use planning frequently may
be a local issue or even site-specific, long-term regional implications
of large-scale FGC waste disposal can also be important.  In this regard,
the most cost-effective disposal system based upon the economics of the
type of FGC system and the construction of the associated waste process-
ing and disposal facilities may not be the most desirable approach in
terms of long-term land use and availability.
     Long-term maintenance of retired disposal sites is related to land
use and availability.  The need and costs for long-term maintenance or*
ultimate reclamation of a site cannot be determined based upon current
knowledge.  It therefore remains an economic uncertainty, but one which
must be given increasing consideration as more disposal systems are
initiated and more information becomes available on existing sites.
     An issue associated in many respects with long-term maintenance of
disposal sites is that of financial liability/responsibility for both
the disposal site itself and any environmental impacts resulting from
the disposal operation.  This is both a legal and economic question,
and includes such aspects as:
     •  Whether a contractor for waste processing and/or disposal
        can assume the overall responsibility and liability of the
        utility;
     •  What the extent of liability is for not complying with
        regulations or for causing impacts (sociological as well
        as environmental) that are not within the regulatory
        coverage; and
     •  The availability, extent of coverage and cost of
        insurance to cover the financial liability of the
        utility or contractor.
Some of these questions are now being addressed, but a clear-cut
resolution will be many years away, if at all.
                                   6-28

-------
6.5  Data Gaps
     Current data gaps related to the economics  of  the disposal  of  FGC
wastes include both cost information per se,  as  well  as waste properties
and disposal requirements that directly impact disposal costs.   In  this
regard, data gaps refer to areas which could be currently addressed by
government and/or industry initiatives.  The most important of these are
listed below.
     •  There is a general lack of reliable cost information from
        commercial operations of most types of FGC disposal.  On-
        going and planned EPA demonstration projects should at
        least partially fill this gap.
     •  There have been no definitive studies on the  disposal of
        wastes  from dry sorbent  systems and the associated  costs.
     •  Existing physical and engineering properties  data  on some
        types of wastes are not  adequate as a  basis for developing
        design  requirements needed for  reliable  estimates of cost-
        effective  disposal systems.  Examples include:   the dis-
        posal of gypsum  untreated in dry impoundments;  the amount
        of ash  and lime  required for adequate stabilization of
        some sulfite-rich wastes; and  the potential  for use of
        well-stabilized  materials as liners  for dry  impoundments
        of ash  blended wastes.
                                   6-29

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                              REFERENCES


1.  National Electric Reliability Council - Seventh Annual Review of
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2.  1977-1978 Electrical World Directory of Electrical Utilities.  McGraw
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3.  Annual Environmental Analysis Report prepared by Mitre Corporation,
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4.  "EPA Industrial Boiler FGD Survey-Third Quarter 1978," PEDCo Environ-
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5.  "EPA Utility FGD Survey, April-May 1978," PEDCo Environmental,  Inc.,
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6.  "Steam Electric Plant Air and  Water  Quality  Control  Data,"  summary
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7.  "Study of Non-hazardous Pastes from Coal-fired Electric  Utilities" by
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8.  Hazardous Wastes  -  Proposed Guidelines & Regulations and Proposal on
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 9.  "State of  the Art of FGD Sludge Fixation,"  W.  A.  Duvel,  W.  R.  Gallagher,
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10.   "Survey of  FGD Systems:  La Cygre  Station Kansas City Power & Light
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11.  "Survey of Flue Gas Desulfurization Systems:  St. Clair Station Detroit
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12.  "Eighteen Months of Operation Wash Disposal System, Bruce Mansfield
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     November 8-11, 1977.
                                    R-l

-------
13.  "Designing Large Central Stations to Meet Environmental Standards,"
     Power, 1976 Generation Planner, p. 25-34.

14.  Personal Communication from Carl Gilbert of Dravo to Chakra Santhanam,
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15.  Personal Communications from Dean Golden of EPRI to Chakra Santhanam
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16.  "A Primer on Ash Handling" by Allen-Sherman Hoff Co., 1976.

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18.  Development Document for Proposed Effluent Limitations Guidelines and
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19.  Williams R. E., Kealy, C. D., and Mink, L. L. 1973.  Effects and
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20.  "Sulfur Oxide Throuwaway Sludge Evaluation Panel (SOTSFP) Vol. II -
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21.  Commerce Business Daily.  Friday, February 16, 1979, page 1.

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24.  "Environmentally Acceptable Landfill from Air Quality Control System,"
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25.  "Sulfur Oxides Removal by Wet Scrubbing-Apploration to Utility
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26.  "Options for Treating & Disposing of Scrubber Sludge," R. W. Goodwin,
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                                   R-2

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27.   Barrier,  J.  W.,  H.  L.  Faucett,  and L.  J.  Henson,  "Economics  of  Disposal
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28.   "Data Base for Standards/Regulations Development  for Land Disposal
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29.   "An Evaluation of the Disposal of FGD Wastes in Mines & the Ocean -
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30.   Cassidy, S. M., Elements of Practical Coal Mining,  Society of Mining
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31.   Ocean Disposal of Flue-Gas-Cleaning Wastes by C. B.  Cooper,  R. R. Lunt,
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32.  Duedall,  I. L.,  et al,  "Environmental Assessment of Coal Waste Disposal
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33.  Hazardous Waste  Guidelines  and  Regulations—Criteria,  Identification,
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 36.  Flue Gas Desulfurization Waste Disposal Field Study at the Shawnee
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 37.   Disposal of By-Products From Nonregenerable Flue Gas Desulfurization
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                                     R-3

-------
38.  "Mine Disposal of FGD Waste," Sandra L. Johnson and Richard R. Lunt,
     Arthur D. Little.  Presented at FGD Symposium, Hollywood, Florida,
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39.  Landfill and Ponding Concepts for FGD Sludge Disposal, by J. Rossoff,
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40.  The Environmental Effects of Trace Elements in the Pond Disposal of
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42.  Theis, T. P. L., The Potential Trace Material Contamination of Water
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44.  Haas,  J.  C., and K.  L.  Ladd,  "Environmentally Acceptable Landfill
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     Biology Division.  Contact No. 78-DX—37x.  Environmental Protection
     Agency, IERL, Research Triangle Pane. NC, 2771.

47.  Personal Communication.  Julian W. Jones,  EPA-IERC to Chakra Santhanam,
     Arthur D. Little, January 1979.

48.  "The Impact of RCRA (PL 94-580) on Utility Solid Wastes" Hart F. C. &
     DeLaney, B.  T., Fred Hart Associates EPRI FP-878, TPS 78-779, Final
     Report Electric Power Research Institute.  Palo Alto, California,
     94303, August 1978.

49.  Development Document for Effluent Limitation Guidelines & New Source
     Performance Standards for the Steam Electric Power Generating-Point
     Source category EPA 440/l-74-029a Group I Environmental Protection
     Agency, Washington, DC, 20460, October 1976.


                                    R-4

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50.   Landfill and Ponding Concepts for  FGD Sludge  Disposal  by  the  Aero-
     space Corporation.   Presented at the U.S.  EPA IERL Industry Briefing
     Conference on Technology for Lime/Simestone Wet Scrubbing, August  29,
     1978.

51.   Federal Register,  Vol.  43,  No. 92, Thursday,  May 18,  1978.

52.   White House Press  Release,  Washington, DC, December 2, 1977.

53.   Federal Register,  Vol.  39,  39 FR 42510, i  member 5, 1974.

54.   Disposition of Wastes from Stack Gas Sulfur Dioxide Removal  Processes,
     by D. J. Hagerty,  et al, University of Louisville, Report to
     Institute for Mining and Minerals Research, January 1, 1976.

55.   Lime/Limestone Scrubbing Sludge Characterization—Shawnee Test
     Facility by TVA.  EPA-600/7-77-123, Environmental Protection Agency
     Office of Resource and Development, Washington, DC, 20460, October
     1977.

56.   Geotechnical Properties of Flue Gas Desulfurization Sludges by
     Barry K. Thacker,  University of Louisville, A Thesis submitted to
     the Faculty of the University of Louisville Speed Scientific School,
     May 1977.

57.   Disposal and Uses of Power Plant Ash  in Urban Area, P. G. Sikes and
     H. J. Kolbeck, Journal of the Power Division,  9,741, ASCE, May 1973,
     pp 217-234.

58.  "Physical and Chemical Characteristics of Fly  Ash and  Scrubber Sludge
     from Some Low-Rank Western  Coals", by H.  Ness,  A.  Volesky, and
     S. Johnson, U.  S. Department of Energy, presented at  the Ash Management
     Conference, Texas A&M,  September  25-27, 1978.

59.  "FGD Waste  Disposal Effective Despite Surprises," K.  H.  Workmen and
     E. H. Rothguss, Power  Engineering,  November  1978, pp  60-63.

60.  Disposal of FLue  Gass  Cleaning Wastes: EPA  Shawnee  Field Evaluation—
     Second Annual Report,  March 1977, by R. B. Fling, W.  M.  Graven,
     R.  C. Rossi,  and  J.  Rossoff, Aerospace Corporation,  Los  Angeles,
     California, EPA Contract No. 68-02-1010.

 61.  The Solid Waste Impact of Controlling SO^ Emissions  from Coal-Fired
      Steam Generators  Volume II:  Technical Discussion, by P. P.  Leo
      and J. Rossoff, Aerospace Corporation, EPA Contract  No.  68-01-3528
     Work Assignment'No. 6.

 62.   Chemical Properties and Leachate Characteristics of FGD Sludges,
      by J. L. Mahloch, Environmental Effects Lab., U.S. Army Engineer
      Waterways Experiment Station, Miss.  Presented at AIChE Symposium,
      August 29-September 1, 1976, Atlantic City, NJ.
                                     R-5

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63.  Leachate from Disposal of FGD Sludge in Deep Mines, by W. A. Duvel, Jr.,
     J. R. Rapp and R. A. Atwood, Michael Baker, Jr., Inc.  Presented at
     the 71st Annual Meeting of the Air Pollution Control Association,
     Houston, Texas, June 25-30, 1978.

64.  Full-Scale FGD WAste Disposal at the Columbus and Southern Ohio
     Electric's Conesville Station, prepared by Danny L. Boston and
     James E. Martin, Columbus and Southern Ohio Electric Company, 1977.

65.  Personal Communication, Carl Labowitz fo Dravo to Chakra Santhanam
     of Arthur D. Little, November 1978.

66.  Seleginar, James David, "Chemical & Physical Behavior of Stabilized
     Scrubber Wastes and Fly Ash in Seawater," Masters Thesis, Marine
     Sciences Program, State University of New York at Story Brook,
     January 1978.

67.  Chemical Fixation of FGD Sludges - Physical and Chemical Properties,
     by Jerome Mahloch, Environmental Effects Lab., U.S. Arm Engg.  Water-
     ways Experiment Station, Vicksburg, Miss., 1977.

68.  PHysical and Engineering Properties of Hazardous Industrial Wastes
     and Sludges, by M. J. Bartos, Jr. and Mr. R. Palermo, U.S. Army
     Engineer Waterways Experiment Station, under EPA Contract No. IAG-
     D4-0569, August 1977.

69.  Solid Wastes from Coal-Fired Power Plants:  Use or Disposal on Agri-
     cultural Lands, G. L. Terman, Tennessee Valley Authority, National
     Fertilizer Center, June 1978 and Personal Communication, Paul Giordano,
     TVA.

70.  Klym, T. W. and D. J. Dodd, "Landfill Disposal of Scrubber Sludge."
     Paper presented at the National ASCE Environmental Engineering
     Meeting, Kansas City, Mo., October 1974.

71.  Peck, R.B., W. H. Hanson and T. H. Thorburn, Foundation Engineering,
     John Wiley & Sons, New York, 1973.

72.  Van Ness,  et al, "Field Studies in Disposal of Air Quality Control
     System Wastes."  (no reference)

73.  Duedall, Iver W., Harold B. O'Connors, Jr., Jeffrey H. Parker, Frank
     E. Roethel, and James D. Seleginar, "A Preliminary Investigation of
     the Composition, Physical and Chemical Behaviors and Biological
     Effects of Stabilized Coal-Fired Power Plant Wastes (SCPW) in the
     Marine Environment - A Final Report."  Prepared for New York Energy
     Research & Development Administration, by Marine Sciences Research
     Center, State University of New York, Story Brook, New York,
     November 21, 1977.
                                   R-6

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74.   Hydraulic Disposal to Mines,  prepared by Nelson R. Tonet, Duquesne
     Light.   Presented at ASME-IEEE  Joint Power  Generation Conference,
     Pittsburgh,  September 27  - October  1, 1970.

75.   "Study of the Use of Lime/Limestone Flue Gas  Desulfurization  Sludge
     in Underground Mines Subsidence Prevention",  Work by Radian Corporation
     for the U. S. Bureau of Mines,  Department of  Interior,  Washington,
     D. C.,  1975.

76.   "Feasibility Study Underground Coal Mine Drainage Abatement and
     Subsistence Control Using FGD Wastes",  W. A.  Duvel,  D.  W.  Hupe,
     D. A. Palomer, and R.  J.  McLaren,  Michael Baker,  Inc.   Report to
     EPA-IERL, Cincinnati,  Ohio  45268,  Draft Report,  May 1978.

77.   "Surface Coal Mining and Reclamation Operations,  Proposed Rules for
     Permanent Regulatory Programs," Federal Register, Vol.  43, No. 181,
     September 18, 1978, p.  41661-41940.

77.  "Surface  Coal Mining and  Reclamation Operations, Proposed Rules for
     Permanent REgulatory Programs," Federal Register, Vol. 43, No.  181,
     September 18, 1978, p. 41661-41940.

78.  Ibid.,  p. 41887  (Part  816.52)  and  p. 41907  (Part 816,52).

79.  Ibid.,  p. 41751,  p. 41843 (Part 780.21), p.  41894  (Part 816.95).

80.  Hazardous Waste  Guidelines and Regulations," Federal Register,
     Vol  43, No.  243,  December 18,  1978, p.  58945-59022.

81.  Ibid.  p.  59015  (Part 250.46-2), pp. 58991-2.

82.  Ibid,  p.  58956  (Part 250.13  [d]).

83.  Ibid,  p.  59000  (Part 250.43  [f,h]).

84.  Ibid,  p.  59004-6 (Part 250.43.7,  .43-8).

 85.  Ocean Dumping,  Parts  227 and 228,  Federal  Register, Vol.  42, No.  7, 1977.

 86.   Ibid, p. 2477-8 (Part  227.5).

 87.   Ibid, p. 2466.

 88.   Ibid, pp. 2487-9 (Part 228.13).

 89.   "Proposed Methods for Leaching of Waste Materials", American
      Society for Testing and Materials, Philadelphia, PA, Committee D-19,
      May 1978.

 90.  Lowenbach, William, "Compilation  and Evaluation of Leaching Test
      Methods," U.S. Environmental  Protection Agency  Report EPA-600/2-780-095,
      May 1978.
                                    R-7

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 91.  Fenn, D., E. Cocozza, J. Isbister, 0. Braids, B. Yare, P. Roux and
      B. Vincent, "Procedures Manual for Ground Water Monitoring at Solid
      Waste Disposal Facilities," U.S. Environmental Protection Agency
      Report,  EPA-530/SW-611, August 1978.

 92.  "Manual  of Methods for Chemical Analysis of Water and Wastes," U.S.
      Environmental Protection Agency Report EPA-625-16-74-003, 1974.

 93.  "Standard Methods for the Examination of Water and Wastewater,"
      American Public Health Service, Washington, DC, 13th Edition, 1971.

 94.  Gibb, T. R. P., (ed), "Analytical Methods in Oceanography," American
      Chemical Society, Advances in Chemistry Series 147,  (1975).

 95.  Chemical Week, December 6, 1978.

 96.  ASTM D19.12, Draft Proposed Standard Protocol for Acute Fish Toxicity
      Bioassay and Draft Proposed Salmonella/Mammalian-Minosome Mutagenesis
      Assay for Complex Environmental Mixtures, presented at meeting of
      D19.12, American Society for Testing & Materials, Philadelphia, PA,
      October  24, 1978.

 97.  Personal Communication,  Florida Department of Environmental Regulation
      to Sarah Bysshe, Arthur D.  Little, Inc. 1978.

 98.  Morgan, G.  B., "Energy Resource Development:  The Monitoring
      Components," Environmental Sci.  Tech. 12, 34-43 (1978).

 99.  Miller, S., "Federal Environmental Monitoring:   Will the Bubble
      Burst?" Environmental Sci.  Tech.  12^,1264-1269 (1978).

100.  Frascino, P. J. and Vail,  D. L.  "Utility Ash Disposal - State of the
      Art" Proceedings of the IV Ash Utilization Symposium, St. Louis,
      Mo., March 24-25, 1976.

101.  "A Procedure for Evaluation of Environmental Impact," Leopold, L. B.,
      et al.  Circular 645, U.S.  Geological Survey, Washington, D.C., 1971.

102.  Barrier, J. W., "Comparative Economics of FGD Waste Disposal," EPA
      Industry Briefing Conference, August 1978.

103.  Barrier, J. W., H. L. Faucett, and L. J. Benson, "Economics of FGD
      Waste Disposal," U.S. Environmental Protection Agency Report, EPA-
      600/7-78-058a, March 1978.

104.  Barrier, J. W., "Economics for Auburn Study of Sludge Dewatering
      Equipment,"  A Report to H. L. Faucett, TVA, September 1978.

105.  Rossoff, J. and R. C. Rossi, "Disposal of By-Products fron Non-
      Regenerable Flue Gas Desulfurization Systems:  Initial Report,"
      U. S. Environmental Protection Agency Report, EPA-650/2-74/037a,
      May, 1974.


                                     R-8

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106.  Rossoff, J.  and R.  C.  Rossi,  "Flue Gas Cltaring Waste Disposal  EPA
      Shawnee Field Evaluation," presented at the EPA Flue Gas  Desulfur-
      ization Symposium,  New Orleans, L.A. , March 1976.

107.  Rossoff, J., et al.,  "Disposal of By-Products from Non-Regenerable
      Flue Gas Desulfurization Systems:  A Status Report," Presented  at the
      EPA Flue Gas Desulfurization Symposium, Atlanta, GA, November 1974.

108.  Rossoff, J., et al, "Disposal of By-Prod-icts from Non-Regenerable
      Flue Gas Desulfurization Systems:  Seccnu Progress Report," U.S.
      Environmental Protection Agency Report, EPA-600/7-77-052, May 1977.

109.  Rossoff, J., et al, "Disposal of By-Products from Non-Regenerable
      Flue Gas Desulfurization Systems:  Final Report," U.S. Environmental
      Protection Agency Report  (Draft), March 1978.

110.  Atwood, K. E. and Greenway, W. R.   "Fly Ash Handling  Systems
      Study Relating  to  Steam  Electric Power Generating Point  Source
      Category - Effluent Guidelines and Standards" prepared by C.  W. Rice
      Division of  NUS Corporation to the Utility Water Act Group (UWAG)
      July 1975.

111.  Jones,  B.  F., et al,  Radian Corporation, "Study of Non-Hazardous Wastes
      from Coal-Fired Electric Utilities", DCN 200-187-41-08 Report to
      EPA-IERL,  Research  Triangle Park, NC 27711, Draft Final Report,
      December 15, 1979.

112.  SCS Engineers "Economic Impact of Alternative Flue Gas Desulfurization
      (FGD) Sludge Disposal Regulations in the Utility Industry" Report
      to EPA Municipal Environmental Research Laboratories, Cincinnati,
      Ohio.  Draft Final Report, January 1979.

113.  Leo, P. L. and J. Rossoff, Aerospace Corporation, "Controlling S09
      Emissions from Coal-Fired Steam-Electric Generators: Solid Waste  impact,"
      Two Volumes, EPA Report No. EPA-600/7-78-044a and b.  Environmental
      Protection Agency, Washington, D. C.,  20460, 1978.

 114.  Goodwin, R.  W. and R. J. Gleason, "Options for  Treating and Disposing
      of  Scrubber  Sludge," Combustion. October 1978.

 115  Epton,  J.  L. and Larimer,  F.  W.,   Interim Report on "Toxicity of
      Leachates",  ORNL, Oak Ridge,  Tnn. Draft Report, January 21, 1979.

116.  Personal Communication,  John  Munick,  ASTM to  C.J.  Santhanam,
      Arthur  D.  Little, Inc.,  February  1979.

 117. Personal Communication, D. J.  Hagerty, University of Louisville, to
      C. J. Santhanam, Arthur D. Little, Inc., 1979.
                                      R-9

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                            INDEX - VOLUME V
Acid-forming waste, regulatory control 3-65
Air-related impacts  2-95 to 2-97, 3-86 to 3-89, 4-27, 4-42
Aquifers, protection under RCRA  3-16

Backfilling under Surface Mining Control and Reclamation Act  3-77
Basins, waste disposal, control under RCRA  3-70
Bioaccumulation  5-12
Bioassay testing  5-11 to 5-13

Biological monitoring  5-9 to 5-14, 5-16, 5-18
Boiler derating under National Energy Act  3-90
Bottom Ash  2-4
      physical properties, disposal practices  2-11 to 2-15, 4-20, 6-23

Cadmium concentration in waste,  ocean dumping limitations  3-59
Calcium sulfate solubility  2-7 to 2-0, 4-14
The Clean Air Act  3-1, 3-86
Climate, effect on waste properties  2-53 to 2-54
Coal ash, effect on waste properties  2-1 to 2-4
Codisposal of ash and FGD waste  2-47, 4-45
Compaction, effect on waste properties  2-52, 2-109, 4-21 to 4-22
Consolidation, effect on eventual land use  2-82, 4-6 to 4-7, 4-22

Dam Inspection Act  3-67 to 3-68
Dewatered impoundments  2-88, 4-4, 4-43
Disposal facility, for FGD wastes  3-19, 6-8
Disposal of non-coal wastes  3-80
Disposal site size  4-8 to 4-10
Dravo stabilization process  2-31

EPA, effect on disposal practices  3-3 to 3-5,  3-72
Environmental impact  2-78 to 2-81, 4-1

Fly Ash
     blending of  2-44 to 2-47, 2-92
     disposal practices  2-9 to 2-11, 4-20, 6-22, 6-8
     dry, disposal costs  6-8
     physical properties  2-3
     water contamination  2-94
     wet disposal costs  6-8

FGC wastes
     disposal economics  6-1, 6-10, 6-25
     disposal field studies  2-20 to 2-21
     disposal in surface mines  2-63 to 2-66, 2-89, 3-74 to  3-76
                                 R-10

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FGC wastes (continued)
     disposal in underground mines  2-68,  2-89
     dust emissions from 3-86,  5-2
     dry disposal of  2-42 to 2-43,  2-88,  4-20  to 4-27
     erosion of  2-53,  2-96, 4-30
     extract composition from  5-6 to 5-7
     extraction procedure for  3-13, 3-18, 5-5  to 5-6
     forced oxidation of  2-8, 4-43
     grain properties of  4-3, 4-5
     interim ponding of  2-43
     leachates  4-14 to 4-17, 4-33 to 4-34, 4-40
     leaching of  2-40, 4-12 to 4-13, 5-16
     liquefaction of  2-83, 4-6
     mechanical landfilling of  2-44
     ocean disposal of  2-113, 2-72 to 2-77, 3-56 to  3-58
     physical properties of  4-3
     permanent  impoundments  for   3-77
     permeability  of   4-16.  4-18
     pit-bottom disposal of  2-65
     sludges  3-75 to  3-76,  4-3,  4-20
     stability  of  2-50, 4-11, 4-10 to 4-22, 5-15
     treatment  costs for  6-7
     V-notch disposal of  2-65, 4-34
     waste types   2-1
FGD
     liquid wastes  2-8
     nonrecovery systems  2-5
     solid wastes  2-5 to 2-8
     stability  of  3-62,  3-78, 4-2, 4-13,  4-20,  4-28, 4-44
     U.S. capacity of  1-1
     waste disposal of  2-16 to  2-20, 6-23

Generating capacity, Coal-Fired  Utilities  1-1
Ground  water monitoring   3-17, 3-20,  3-36, 5-1,  5-7
Gypsum, production of   2-8
Gypsum  stacking  2-35  to  2-37

Hazardous wastes
      characteristics   3-18
      management, under RCRA  3-11 to 3-12
      standards, under  RCRA  3-13 to 3-15, 5-2
      under  RCRA  3-11  to 3-13,  3-17 to  3-19
 Hydraulic backfilling of mine tailings   2-69

 Landfilling, design of  2-56 to 2-58, 3-24, 3-70
 Land-related impact  2-82 to 2-85, 2-90,  4-42
 Land costs for waste disposal  6-10
 Land reclamation  3-22, 3-80, 4-23 to 4-25, 4-31 to  4-32
 Land use for disposal  3-24, 3-69, 3-81,   6-9, 6-26
 Land use planning in waste disposal  6-26 to  6-28
 Leachate/soil  interactions  4-16 to 4-17
                                     R-ll

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Marine Protection Research and Sanctuaries Act of 1972  3-56
Mercury concentration, in wastes  3-59
Microbial oxidation  2-95
Mine drainage  3-32
Monitoring samples, from disposal sites  5-8, 5-18

National Energy Act  3-1, 3-90, 3-91
National Pollutant Discharge Elimination System (NPDES)  3-25, 3-37

Occupational Safety & Health Administration  (OSHA)  3-4 to 3-6, 3-67
Ocean disposal of FGC wastes
     costs of  6-8
     impacts of  3-61
     monitoring of  3-60 to 3-61, 5-3
     penalties for  3-57
     permits for  3-58
     pipeline transport of  2-73
     surface craft transport of  2-74 to 2-75, 6-22
Office of Solid Waste (OSW)  3-16
Office of Water Supply (OWS)  3-20
Open dump, use in disposal practices  3-15
Overburden  2-66

Particulate emission limit under NSPS  2-2
Phos-acid industry, use of gypsum stacking  2-36
Pneumatic backfilling of mine fillings  2-69
Ponds for disposal
     design of  2-33, 6-14
     liners for 2-32, 2-38, 4-12, 4-45
          leakage detection from  2-38
          permeability of  2-39
     pipeline systems for  2-33 to 2-35
Post-closure care of waste disposal sites  3-20, 3-70, 3-84, 6-28
Post-closure land use of waste disposal sites  2-54  to 2-56, 2-87,  4-11
        4-25, 4-31, 5-16
Post-mining land use  3-77
Power Plant and Industrial Fuel Act  3-1
Pozzolanic activity,  effect on waste properties  4-6 to 4-7
Predisposal monitoring of disposal sites  5-10 to 5-12, 5-19

Regulatory considerations for disposal  3-1 to 3-8
Resource Conservation & Recovery Act (RCRA)  2-112  to  2-113,  3-8 to  3-15
          3-35, 3-62  to 3-63,  3-69,  5-1,  5-4, 6-23

Revegetation of disposal sites  3-78 to 3-79, 4-23, 5-14
Runoff from disposal sites  2-55, 3-35, 4-12, 4-21, 4-28
                                   R-12

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Safe Drinking Water Act  3-6
Sanitary Landfill  3-15
Scrubber system costs  6-6, 6-10 to 6-12, 6-21
Sedimentation ponds  3-22
Shannon Weaver Diversity Index  5-14
Site design  2-106 to 2-107
Site location of disposal sites  2-86, 4-8 to 4-10
Site selection 2-103 to 2-105, 3-70, 4-42
Sludge compressibility  4-6 to 4-7
Solid waste disposal control under RCRA  3-1], 3-17
Spoil bank method of disposal  2-65
State regulatory control and programs   3-37  to 3-38,  3-73 to 3-74,
       3-81 to 3-83
State requirements for disposal of solid wastes
     California  3-50
     Florida  3-53
     Illinois  3-44 to 3-46, 3-55
     Kansas  3-48 to 3-49
     Maine  3-39
     New Jersey  3-41
     North Dakota  3-54
     Oregon  3-51, 3-83
     Pennsylvania  3-42, 3-53
     Tennessee  3-43, 3-52
     Texas  3-47,  3-83
Stabilization additives  2-47  to  2-49,  2-92,  4-19, 4-44
Storage silos for  dry disposal of ash  2-42
Stowing of wastes  in active mines  2-70,  4-21
Strip  mining  of coal mines 2-60
Subsidence,  effect on  eventual land use  2-82
Sulfate-rich wastes  2-11  to  2-112, 4-3,  4-37, 4-43
Sulfite-rich wastes  2-108 to 2-111,  2-93, 4-3,  4-14,  4-33,  4-37,  5-7
Surface impoundment,  for waste disposal  3-70
Surface Mine  Control and Reclamation Act  3-7, 3-21 to 3-23, 3-31 to 3-34
             3-64, 3-74 to  3-79, 4-30, 5-1
Surface mines,  disposal usage  2-60 to 2-62, 4-32, 4-34,  6-18
Surface water quality  control under RCRA  3-35 to 3-38

Total oxidizable sulfur (TOS)  4-33
Toxic Substances Control Act  (TSCA)  5-12
Transportation costs,  for  waste disposal  6-18

Underground injection of waste  3-20 to 3-21
Underground mines, use for disposal of wastes  2-67 to 2-71, 4-32, 6-18
 Unstabilized sludges  2-93, 4-37 to 4-40

Waste materials as fill  3-78
Water monitoring, methods of  5-7 to 5-9
 Water related impact  2-90 to 2-95, 4-26 to 4-27, 4-32 to 4-33, 4-42
 Wet ponding costs  6-6, 6-10  to  6-12,  6-21
 Wet stabilization process  4-12
 Wind erosion of disposal  sites   2-95

                                   R-13

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                               TECHNICAL REPORT DATA
                         (Please read Instructions on the reverse before completing}
1. REPORT NO.
EPA-600/7-80-012e
                          2.
                                                     3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE Waste and Water Management for
Conventional Coal Combustion Assessment Report-
1979; Volume V. Disposal of FGC Wastes
                                 6. REPORT DATE
                                 March 1980
                                 6. PERFORMING ORGANIZATION CODE
7 AUTHOR(S)C.J.Santhanam,R.R.Lunt,C.B.Cooper,
D.E.Klimschmidt,I.Bodek, and W.A.Tucker (ADL);
and C.R.Ullrich OJniv of Louisville)	
                                                     B. PERFORMING ORGANIZATION REPORT NO.
9 PERFORMING ORGANIZATION NAME AND ADDRESS
Arthur D. Little, Inc.
20 Acorn Park
Cambridge, Massachusetts 02140
                                 1O. PROGRAM ELEMENT NO.
                                 EHE624A
                                 nTCONTRACT/GRANT NO.

                                 68-02-2654
12. SPONSORING AGENCY NAME AND ADDRESS
 EPA, Office of Research and Development
 Industrial Environmental Research Laboratory
 Research Triangle Park, NC 27711
                                                 PERIOD COVERED
                                 14. SPONSORING AGENCY CODE-
                                  EPA/600/13
is. SUPPLEMENTARY NOTES iERL.RTp project officer is Julian W. Jones, Mail Drop 61, 919/
541-2489.
IB. ABSTRACT
              rep0rtj  the fifth of five volumes ,  focuses on disposal of coal ash and
 FGD wastes which (together) comprise FGC wastes.  Disposal of these wastes  repre-
 sents significant sources of environmental pollution unless proper disposal technol-
 ogies are employed. Continued R and D efforts  have provided substantial baseline
 information on environmentally sound disposal methods.  The report assesses  the
 various options for the disposal of  FGC wastes  with emphasis on disposal on land.
 A number of technical, economic,  and regulatory factors appear to encourage inc-
 reasing use of dry disposal methods. Regulatory considerations  impacting FGC
 waste disposal are assessed. Regulations under the Resource Conservation  and
 Recovery Act, the major Federal legislation  impt.cting FGC waste disposal, are
 still emerging. An assessment of the monitoring requirements from the viewpoints
 of regulation and environmental control is reported.  Ongoing studies on the  econo-
 mics of FGC waste disposal are  reported and assessed. Cost estimates for  sound
 disposal practice are £9 to #15 per dry metric ton of waste.  Environmental impact
 issues concerning disposal options include physical stability, public policy and land
 use, and leachate mobility. A summary of data gaps  and  research needs  in this area
 are  outlined.
17.
                            KEY WORDS AND DOCUMENT ANALYSIS
                DESCRIPTORS
                                         b.IDENTIFIERS/OPEN ENDED TERMS
                                             c. COSATI Field/Group
 Pollution
 Coal
 Combustion
 Assessments
 Management
 Waste Disposal
Water
Flue Gases
Cleaning
Ashes
Pollution Control
Stationary Sources
Flue Gas Cleaning
13E
2 ID
21B
14B
05A
07B

13H
18. DISTRIBUTION STATEMENT

 Release to Public
                     19. SECURITY CLASS (This Report I
                     Unclassified
                        21. NO. OF PAGES
                          330
                     20. SECURITY CLASS (Thispage)
                     Unclassified
                                             22. PRICE
EPA Form 2220-1 (t-73)
                                       R-14

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