EPA-600/3-76-111
December 1976
Ecological Research Series
                          DESIGN  CONSIDERATIONS FOR
          PULP AND  PAPER-MILL  SLUDGE LANDFILLS
                                   Municipal Environmental Research Laboratory
                                        Office of Research and Development
                                       U.S. Environmental Protection Agency
                                                      flhio 45268

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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 five  series. These five  broad
 categories  were established to facilitate further development and application of
 environmental technology. Elimination  of traditional  grouping was consciously
 planned to  foster technology transfer and  a maximum interface in related fields.
 The five series are:

     1.    Environmental Health Effects Research
     2.    Environmental Protection Technology
     3.    Ecological Research
     4.    Environmental Monitoring
     5.    Socioeconomic Environmental Studies

 This report has been assigned to the ECOLOGICAL RESEARCH series. This series
 describes  research on the effects  of pollution on humans, plant  and animal
 species, and materials.  Problems are  assessed for their long- and short-term
 influences.  Investigations include formation, transport, and pathway studies to
 determine the fate of pollutants and their effects. This work provides the technical
 basis for setting standards to  minimize undesirable changes in living organisms
 in the aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                        EPA-600/3-76-111
                                        December 19?6
      DESIGN CONSIDERATIONS FOR PULP AND

          PAPER-MILL SLUDGE LANDFILLS
                      by

             Richard H. Ledbetter
U.S. Army Engineer Waterways Experiment Station
         Vicksburg, Mississippi  39l8d
   Interagency Agreement No. EPA-IAG-D5-F657
                Project Officer

              Robert E. Landreth
  Solid and Hazardous Waste Research Division
  Municipal Environmental Research Laboratory
            Cincinnati, Ohio  U5268
  MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
      OFFICE OF RESEARCH AND DEVELOPMENT
     U.S. ENVIRONMENTAL PROTECTION AGENCY
            CINCINNATI, OHIO

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                                  DISCLAIMER
    This report has been reviewed by the Municipal Environmental Research Lab-
oratory, U. S. Environmental Protection Agency, and. approved, for publication.
Approval does not signify that the contents necessarily reflect the views and
policies of the U. S. Environments1 Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or recommendation
for use.
                                      11

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                                   FOREWORD
     The Environmental  Protection Agency (EPA) was created because of
increasing public and government concern about the dangers of pollution to
the health and welfare of the American people.  Noxious air, foul water, and
spoiled land are tragic testimony to the deterioration of our natural environ-
ment.  The complexity of that environment and the interplay between its com-
ponents require a concentrated and integrated attack on the problem.

     Research and development is that necessary first step in problem solution
and it involves defining the problem, measuring its impact, and searching for
solutions.  The Municipal Environmental Research Laboratory develops new and
improved technology and systems for the prevention, treatment, and management
of wastewater and solid and hazardous waste pollution discharges from munici-
pal and community sources, for the preservation and treatment of public drink-
ing water supplies and to minimize the adverse economic, social, health, and
aesthetic effects of pollution.  This publication is one of the products of
that research, a most vital communication's link between the researcher and
the user community.

     This report is a result of research supported by the EPA to obtain
engineering information essential to the design of environmentally acceptable
paper-mill sludge landfills.
                                           Francis T. Mayo, Director
                                           Municipal Environmental Research
                                           Laboratory
                                      in

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                                   ABSTRACT
     This  report presents useful considerations for the engineering design and
 control of pulp and paper-mill sludge disposal landfills.  Engineering design
 will allow more efficient use, thereby contributing to economic and environ-
 mental benefits.  To form the basis for engineering design of sludge material,
 the methodologies and theories of soil mechanics were applied.  The methodo-
 logies should be applicable to most compositions of sludge materials.  Some
 sludge materials may have peculiarities associated with testing, field work-
 ability, and behavior.  However, from accumxilated experiences of applying the
 procedures of this manual, the manual can be adjusted and expanded.

     This report is specifically written for pulp and paper-mill personnel of
 technical background, but with little or no exposure to the soil mechanics
 discipline.  The procedures are such that these individuals can rationally
 approach a landfill operation to attain efficiency and optimization.  This
 report does not present a rigorous treatment or analysis of sludge material,
 but it does give the above-mentioned individuals the procedures for determin-
 ing good approximations of sludge behavior.  Individuals interested in more
 rigorous and theoretical analysis of sludge behavior should consult the list
 of references.

     This report is submitted in fulfillment of Interagency Agreement No.
 EPA-IAG-D5-F657 between the U. S. Environmental Protection Agency, Municipal
 Environmental Research Laboratory, Solid and Hazardous Waste Research Division
 (EPA, MERL, SHWRD), and the U. S. Army Engineer Waterways Experiment Station
 (WES).  Work for this report was conducted during the period January 1975 to
 January 1976.

     This project was conducted by personnel of the Soils and Pavements Labora-
 tory (S&PL), WES, under the general supervision of Mr. James P. Sale, Chief of
 S&PL.  Mr. Richard H. Ledbetter prepared this report.

     Directors of WES during the preparation and publication of this report
were BG E. D. Peixotto, CE, and COL G, Ho Hilt, CE.  Technical Director was
Mr. F. R. Brown.
                                       IV

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                                   CONTENTS
                                                                          Paee
Foreword                                                                   iii
Abstract                                                                    iv
List of Figures and Plates                                                  vi
List of Tables                                                            viii
List of Abbreviations and Symbols                                           ix
Acknowledgements                                                           xiv
I    The Nature and Disposal of Paper Industry Primary Sludges               1
II   Retaining Structures                                                   13
III  Consolidation, Settlement, and Slope Stability                         19
IV   Field Experimental Example                                             27
V    References                                                             38
Figures 1-2^
Tables 1-8
Plate 1
A  Metric Conversion Table                                                  71
B  Testing Procedures for Sludge Properties                                 72
Figures B-l through B-l8
Tables B-l and B-2
Plates B-l through B-13
                                       v

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                          LIST OF FIGURES AND PLATES
Number                                                                      Page
   1   Variability of sludge properties ................        Hi
   2   Relationship of sludge dewater ability to ash content  ......        k2
   3   Solids content versus ash content  ...............        ^3
   h   Mass of leachate constituents  .................        kh
   5   Dike and sludge cross section  .................        ^5
   6   Plan for landfill  .......................        h6
   7   Sludge landfill construction steps  ...............        ^7
   8   Weight and volume relationships  .  .  ..............        U8
   9   Compressed sample  .......................        1±9
  10   Load-depth diagram .......................        50
  11   Load increment added to a sludge layer .............        51
  12   Time factors for consolidation analysis   ............        52
  13   Nomograph for consolidation with vertical drainage  .......        53
  lU   Time factors for consolidation analysis  with gradual
         load application .......................        5^
  15   Slope analysis  .........................        55
  l6   Correction factor for converting vane  shear  strengths  to
         field shear  strengths   ....................        56
  17   Experimental landfill, plan view ................        57
  18   Typical cross  section of experimental  landfill  .........        58
  19   Consolidation  characteristics  of sample  sludge  .........        59
  20   Comparison of  predicted  and measured time-settlement curves,
         lower sludge  layer  ......................        60
  21   Comparison of  actual  and predicted time-settlement  curves,
         upper sludge  layer  ......................        6l
  22   Experimental landfill vane  shear strength  immediately  before
         slope excavation .......................        62
  23   Cut  slope  in experimental sludge landfill   ...........        63
  2U   Cross section  of top  sludge layer for  stability analysis  ....        6k
  B-l   Determining the weight of a sludge specimen  submerged
         in water ...........................      109

                                      vi

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Number                                                                    Page
  B-2  Evacuating air from samples in determination of specific
         gravity	     109
  B-3  Typical calibration curve of volumetric flask  	     110
  B-U  Stages of consistency	„	     110
  B-5  Liquid limit device  	     Ill
  B-6  Details of liquid limit device  ..... 	  .....     112
  B-T  Grooving liquid limit specimen  ......  	  .  .     113
  B-8  Closed liquid limit groove 	 .  	  ......     113
  B-9  Plastic limit determination  	     113
 B-10  Crumbling of threads at plastic limit	  .     113
 B-ll  Apparatus for determining the volume of dry sludge pat  of
         shrinkage limit test	     11^
 B-12  Typical consolidometer (fixed-ring type) vith falling-head
         device for permeability test	     115
 B-13  Typical retainer ring  	 ......  	     Il6
 B-lH  Time-consolidation curve 	     117
 B-15  Square root of time-consolidation curve  	     118
 B-l6  Determination of height of capillary rise	     119
 B-17  Void ratio-pressure curve	     120.
 B-l8  Vane shear test equipment  .	     121
    1  Settlement-Time Plot	      70
  B-l  Water Content - General	     12U
  B-2  Unit Weights (Volumetric Method) 	     125
  B-3  Unit Weights (Displacement Method)  	     126
  B-l*  Specific Gravity Tests	     127
  B-5  Liquid and Plastic Limit Tests  	     128
  B-6  Shrinkage Limit Test	     129
  B-7  Consolidation Test (Specimen Data)  	     130
  B-8  Falling-Head Permeability Test with Consolidometer 	     131
  B-9  Consolidation Test (Time-Consolidation Data) 	     132
 B-10  Consolidation Test - Time Curves	     133
 B-ll  Dial Reading Versus Time-Data for Each Load Increment	     13!*
 B-12  Consolidation Test (Computation of Void Ratios)  	     135
 B-13  Consolidation Test Report	     136
                                      VII

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                                LIST OF TABLES
Number                                                                    Page
   1   Primary Sludge Production Associated with
         Paper Manufacturing	     65
   2   "Normal" Sludge Composition 	     65
   3   Physical Characteristics of Sludges Originating in High Ash
         Sludge Landfills  	     66
   k   Fibre Classification for Selected High Ash Sludges  	     66
   5   Analysis of Leachate Quality  	     67
   6   Trace Elements Contained in Paper-Mill Primary Sludge 	     68
   7   Leachate Attenuation Properties  of Soils   	     68
   8   Physical Properties of Paper-Mill Sludge   	     69
 B-l   Relative Density of Water and Correction  Factor  K  for
         Various Temperatures  	    122
 B-2   Correction Factor  RT  for Viscosity of Water at Various
         Temperatures  	    123
                                     VI11

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                       LIST OF ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS
BOD
°C
cm
  3
cm
COD
deg
EPA
ft
in.
   2
kg/cm'
In. /min
     2
lb/ft
rb/ft3
Ib/ton
LL
mg
mg/£
mm
MTU
pcf
PI
PL
psf
sec /g
    2
SL
T/ft
T/m2
ymho/cm
biochemical oxygen demand
degrees Centigrade
centimetres
cubic centimetres
chemical oxygen demand
degrees
Environmental Protection Agency
feet
inches
square inches per minute
kilograms per square centimetre
pounds per square foot
pounds per cubic foot
pounds per ton
liquid limit
milligrams
milligrams per litre
millimetres
turbidity
pounds per cubic foot
plasticity index
plastic limit
pounds per square foot
seconds squared, per gram
shrinkage limit
tons per square foot
tons per square metre
micromhos per centimetre
                                      IX

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SYMBOLS
A            — cross-sectional area
A            — ash content
 c
a            — area
C            — volumetric change from a given water content  w  (usually the
                liquid limit)
CaCo^        — calcium carhonate
Cd           — cadmium.
Cr           — chromium
Cu           — copper
C            — coefficient of secondary compression
C            — compression index
C            — coefficient of consolidation
 v
D            — diameter
D            — initial dial reading
e            — void ratio
e_           — void ratio after test
e            — initial void ratio existing at  P'
 o                                               o
F            — safety factor
Fe           — iron
G            — specific gravity of solids
 S
H            — height
H            — length of longest vertical path for drainage of water
Hg           — mercury
H            — height of specimen at end of test = H - AH ,  in., where  AH
                is the net change in height of specimen
H.            — average height of the specimen for the load increment
H            — height of solids
 s
H            — total thickness of sludge layer
H            — height of voids
H            — final height of water
 wi
H            — original height of water
 wo
h            — height
h            — height of capillary rise
h,            — height of tailwater
                                       x

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 20
Wi
0
 c
P
Pb
P'
P'
 lower
P'
 upper
P'
 o
R
R
S
S
 U
s
T
T
t
t,
 max
 pri
 sec
initial height of water in standpipe
final height of water in standpipe
hydraulic gradient
correction factor based on density of water at 20°C
coefficient of permeability
coefficient of permeability at 20°C
height
linear shrinkage
magnesium
individual layers of different sludge within a single layer of
sludge
nickel
organic content
load pressure or stress
lead
effective pressure or stress
effective pressure or stress, lower layer
effective pressure or stress, upper layer
average initial effective stress within sludge layer
total initial stress
load pressure
rate of fluid discharge
shrinkage ratio
correction factor for viscosity of water at 20°C
degree of saturation
initial degree of saturation
undrained shear strength
solids content
dimensionless time factor
maximum torque
time
final time
end of construction time
time for primary consolidation
time for secondary consolidation
                                       XI

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"total
U
u
V
Vf
V
 c
W
W
 c
W
 w
W.
 TDW
w
 •fc
w.
 "bws
w
Zn
z
a
 m
Yw
AD
AH
AH
AH
  I
AH
AH
AH
pri
sec
total
  pri
     lower
AH
  pri
     upper
AH
  sec
     lower
AH
  sec
     upper
AH
  total
time for total settlement
percent of primary consolidation
pore hydrostatic pressure
volume
volume of landfill
volume of solids
total weight
weight of dry solids
weight of water
weight of flask plus water
weight of water in specimen after test
original height of water
weight of flask plus water plus solids
water content
zinc
depth
angle
slope angle
dry unit weight
wet unit weight
unit weight of water
change in height of specimen
change in height
decrease in specimen height over log cycle
primary settlement
secondary settlement
total settlement
primary settlement, lower layer
primary settlement * upper layer
secondary settlement, lower layer
secondary settlement, upper layer
total settlement, lower layer
       lower
                                      XII

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  total
Ah
AP
AP
  lower
AP
  upper
AX, Ax
AV
upper
— total settlement, upper layer
--T corrected tailwater - h,  + h
                          t    c
— total load above sludge layer
— total load acting on the lower sludge layer
— total load acting on the upper sludge layer
— slice width
— change in volume
— angle of internal friction
                                      Xlll

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                               ACKNOWLEDGEMENTS
    Mr- Duane W.  Marshall of the National Council of the  Paper  Industry for
Air and Stream Improvements, Inc.,  wrote  Section I of this  report.   Field and
laboratory investigations of sludge material  were conducted by  Dr.  0.  B.
Andersland during the period 1970-197^-
                                     xiv

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                                   SECTION I

                       THE NATURE AND DISPOSAL OF PAPER
                           INDUSTRY PRIMARY SLUDGES
INTRODUCTION

    Associated with the application of conventional and advanced wastewater
treatment technologies, but often obscured by the benefits to receiving-stream
quality, is the accumulation of vaste constitutents into either a highly con-
centrated solution or aqueous suspension of residual solids commonly described
as sludge.  Where those concentrated residuals have no potential for reuse or
by-product development, they must be further processed for ultimate disposal
to the environment.  In doing so, the land as a practical matter represents
the ultimate repository in all but those instances where (a) the incineration
of organic components and subsequent discharge of combustion products to the
atmosphere constitutes a viable alternative or (b) the limited opportunity of
ocean disposal exists.

    For many years, the disposal of wastewater treatment sludges has been re-
garded as a problem as great or greater than that of treating the waste it-
self (l).  Furthermore, the generation of large quantities of hydrous residues
associated with the increasing degrees of waste treatment mandated by existing
regulation has perpetuated, if not amplified, the problem.  Though the dewa-
tering and disposal of these residual solids are widely recognized to repre-
sent a significant fraction of the costs for wastewater treatment, Dick (2)
justifiably concludes that "the attention which has been given to sludge
treatment and disposal in the past, as compared to processes for initial re-
moval of pollutants, has been more nearly proportional to the relative volume
of sludge than to the relative cost of sludge disposal."  Moreover, if over-
all control strategies are to result in minimal net environmental impact,
issues relevant to the accumulation and subsequent management of those resid-
ual solids must be thoroughly weighed in the development of comprehensive en-
vironmental regulation sensitive to intermedia effects.  Included among those
issues are the protection and/or optimum utilization of land resources.

    Among the solids that are accumulated in the treatment of wastewaters of
pulp and paper origin are those lost from the papermaking process and subse-
quently separated during primary clarification.  These solids are composed of
fibre, filler, and coating clays, and in the case of those manufacturing
categories in which wastepaper constitutes a significant portion of the prod-
uct furnish, considerable quantities of impurities.  Information compiled by
Miner (3) and shown in Table 1 indicates that solids losses from most cate-
gories of paper manufacture represent from 2 to U percent of production.  Ex-
ceptions include waste-paperboard where the nature of the paper grade produced

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 at nearly half of the installations surveyed permitted return of primary
 sludge to the production process.  The relatively large losses from deinking
 operations are associated with removal of inks and other nonfibrous materials
 from a wastepaper furnish.  Recently reported results (U) of a survey of pulp
 and paper mills indicated that 78 percent of the sludge generated at those
 mills responding to the survey was disposed of either in or on the land.
 Thus, land disposal remains the largest single method of sludge management
 practiced in the pulp and paper industry.

    Emerging land-use patterns and the decreasing availability of land con-
 sidered acceptable for landfill pose a potential constraint to continued land
 disposal practice in many areas.  In those cases where the fibre or organic
 content of the primary sludge is at least 50 percent, incineration presents a
 feasible alternative.  In fact, 15 percent of the sludge generated at mills
 responding in the above-cited survey was disposed of by incineration.  How-
 ever, costs associated with separate incineration of sludges in quantities
 commonly found at mills have largely limited the practice to those integrated
 operations with wood fuel boilers.

    In addition, the composition of sludges generated at many installations
 further restricts the practice of incineration.  Data reported by Gillespie
 et al. (5) and shown in Table 2 indicate that sludges with ash contents ex-
 ceeding 50 percent are commonly associated principally with the manufacture of
 (a) board, (b) deinked pulp and paper, and (c) integrated and nonintegrated
 fine papers.  Furthermore, the economic impetus for greater fibre recovery and
 utilization will likely result in sludges of progressively greater inorganic
 content.  Incineration is not a realistic alternative for those sludges
 because of (a) their relatively low organic content, (b) the attendant low
 moisture requirements necessary for self-supporting combustion, and (c) the
 inevitable necessity for further land disposal of the predominant inorganic
 fraction.  Barring by-product recovery opportunities, land disposal remains
 the only feasible alternative in that situation.

    Of the mills which must deal with the disposal of high ash sludges, more
 than 100 are located in or adjacent to metropolitan areas where land available
 for solid waste disposal is limited.  As a consequence, it will be incumbent
 upon those mills, and probably others as well, to optimize landfill disposal
by the application of sound engineering principles to all stages of site
 selection, design, operation, and ultimate land use.  Factors warranting con-
 sideration in such an approach would include the significance of sludge compo-
 sition to its engineering behavior, as well as the environmental implication
involved.

    The variability of sludge composition from site to site and the complex
interaction of those sludge constituents known to influence landfill behavior
require the assessment of a sludge's engineering characteristics by means of
functional tests known to be of significance to the rational design of a land-
fill to attain some given objective, inclusive of a given rate or degree of
consolidation, associated rate of leachate discharge, or ultimate land use.
It was in this context that the National Council of the Paper Industry for Air
and Stream Improvement sponsored initial efforts by Andersland (6,7) aimed at
documenting the applicability of traditional soil mechanics techniques for

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relating basic engineering properties of dewatered sludges, specifically shear
strength, permeability, and consolidation.  The utility of those tests for
prediction of actual landfill behavior has been verified for one composition
of sludge in subsequent work conducted by Andersland and sponsored by the
Environmental Protection Agency  (EPA) Division of Solid Waste Research (8,9).
In illustrating the principles and knowledge previously gained, the remaining
sections of this manual are advanced in the following context:

     a.  This report identifies useful consideration in the engineering design
         and control of pulp and paper-mill sludge disposal landfills.  Engi-
         neering design will allow more efficient use, thereby contributing
         to economic and environmental benefits.  The pulp and paper industry
         will benefit economically by being able to dispose of larger quantities
         of sludge in a given landfill than past practices permitted.  Also,
         after completion of landfills, they could be used for recreational
         purposes benefitting the public, or as real estate investments bene-
         fiting the pulp and paper industry.

     b.  Andersland's investigations were carried to completion by field ex-
         periment for only one composition of sludge material.  However,  the
         methodology should be applicable to most other sludge compositions.
         Sludge material other than that used by Andersland may have peculiari-
         ties associated with testing, field workability, and behavior.  How-
         ever, from accumulated experience of applying the tests and procedures
         of this report, the  report can be adjusted and expanded.  In addition
         to landfill design considerations, the test procedures can be used as
         a measure of the effectiveness of dewatering processes.  The example
         material and procedures of this report are based on Andersland's
         investigations.

     c.  This report is written specifically for pulp and paper-mill personnel
         of technical background, but with little or no exposure to the soil
         mechanics discipline.  The procedures are such that the above mentioned
         individuals can rationally approach a landfill operation to attain
         efficiency and optimization.  This report does not present a rigorous
         treatment or analysis of sludge material, but it does give the above-
         mentioned individuals the procedures for determining good approxima-
         tions of sludge behavior.  Individuals interested in more rigorous
         and theoretical analysis of sludge behavior should consult the list
         of references.

SLUDGE COMPOSITION, ITS IMPACT ON ENGINEERING BEHAVIOR

     Paper industry primary sludges are commonly characterized by the relative
proportion of either the combustible or fixed solids (10) comprising the sludge
mass.  However, a characteristic of equal prominence from the perspective of
solids handling and disposal is the water content, which may represent 90 to
98 percent of the sludge mass, as illustrated in Table 2.

Water Relationships

     Gehm (11) has classified the water associated with paper-mill sludges as

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 either  free,  interstitial, or water of imbibition.  The free water is con-
 sidered readily  separable and constitutes but a small fraction of a thickened
 sludge.  Water of  imbibition characterizes water chemically bound or physi-
 cally trapped within the lattice structure of colloidal sols.  It cannot be
 removed by mechanical means and, as such, would pose a limiting condition to
 the  capabilities of such dewatering technology,,  However, the water of imbibi-
 tion represented less than 2 percent of the water associated with cellulesic
 residues evaluated by Zettlemoyer (12) in his study of the surface properties
 of hydrogels  resulting from treatment of pulp and paper-mill effluents.  As a
 consequence,  such  a small proportion of water of imbibition does not charac-
 terize  the dewatering properties of paper-mill sludges.  Rather, Zettlemoyer
 concludes that interstitial water held in the pores of the system by surface
 energy  phenomena amounts to greater than 90 percent of the water associated
 with a  thickened sludge.

     The rate  and extent of interstitial water separation are best defined in
 terms of the  composition and nature of the sludge solids.

 Solids  Composition

 Noncombustible Fraction—
     The noncombustible fraction consists primarily of such filler materials as
 kaolin  clays  and titanium dioxide, with possible quantities of silicates and
 carbonates.   Their composition and physical properties, as well as other pig-
 ments finding specialized application in paper manufacturing, are detailed
 elsewhere (13).  The most striking characteristic of those solids from the
 perspective of sludge dewatering lies in their fine particle size, predomi-
 nantly  smaller than 2y.

     In  addition to variation among various production categories, sludge ash
 content is observed to have considerable daily variation at individual instal-
 lations, dependent upon the grade manufactured and performance of fibre re-
 covery  systems.  The variation over a UO-day period at a mill manufacturing
 fine papers is shown in Figure 1, along with the corresponding variation in
 sludge  filterability.

     Comparison of those variables indicates that the impact of the inert com-
 ponent  alone  is insufficient to explain the variation in sludge filterability.

 Organic Constituents--
    The organic fraction may consist of fibre and such colloidal components as
 highly hydrated wood dust, fibre debris, ray cells, starches, dextrines,
 resins, and protein.  Though but a small proportion of the sludge mass, the
 colloidal components exert a disproportionate effect upon the filtration
properties of paper-mill sludges.

    The fibrillar structure of cellulosic components and the associated size
of interstices impart a capacity for the retention of water by capillary
forces.   Fibre length, or otherwise particle size, of cellulosic constituents
poses a further determinant of the dewatering characteristics.   The separation
of water is restricted by the size of passages available for flow which in
turn is a function of particle size and particle size distribution.   The

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relative importance of various size fractions has been established in studies
of the relationship between the constitution and the dewatering properties of
hydrous sludges (lU).  Fractions smaller than 200 mesh were observed to be
capable of much greater compaction with the resulting smaller pore sizes
yielding greater resistance to flow and greater retention of water by capil-
lary action.  In contrast, the fraction greater than 60 mesh was relatively
easily dewatered.  Chemical composition is of additional influence due to the
potential presence of swellable polysaccharides among the finer size fractions.
They represent the principal constituent capable of binding water at the
molecular level (water of imbibition).  More importantly, however, the deform-
ability and conformability of such particles dictate the degree to which com-
paction can result in a corresponding sealing of the sludge interstices.

Observed Behavior

    The physical characteristics shown in Table 3 were compiled in the course
of studying core samples extracted from existing high ash sludge land-
fills (15)-  The deposits, ranging in age from 3 months to 20 years, showed
considerable vertical stratification reflective of changes in paper grades
produced and fibre recovery practices.  The presence of long fibre (greater
than 100 mesh) in quantities constituting approximately 20 percent of the
sludge mass may be considered representative.  In most cases, the fraction
passing the 200-mesh sieve exceeds the ash content and is indicative of the
extent to which troublesome cellulosic fines are present.  A more detailed
classification of fibrous components greater than 100 mesh for several mills
generating high ash sludges is shown in Table U (3).  The data would suggest
that size distribution is specific to individual mills, though the fibre pres-
ent for the mills shown is predominantly smaller than 38 mesh.

    The interacting effects of particle size, composition, and solids consis-
tency on sludge drainage can be best assessed in terms of their influence on
sludge porosity.  The fine particles common to both the organic and noncom-
bustible fractions exert a dominant physical effect upon sludge dewaterability.

    The resistance of sludges to filtration is particularly sensitive to par-
ticle size and is substantially increased by the presence of fines.   The sig-
nificant reduction in the proportion of voids inherent with particles of such
small size, as well as their lodging within the interstices of larger parti-
cles, constitutes an obstacle to the migration of water within the sludge mass.
In illustrating their impact, Gale (l6) projects that a ten-fold decrease in
effective particle size would result in a 100-fold decrease in filterability.

    The predominance of fines in high ash sludges has been observed to impart
virtual impermeability to dewatered cakes.  Studies with pulp suspensions (lU)
have demonstrated decreasing filterability as a consequence of successive ad-
dition of clay-  In the course of successfully demonstrating the applicability
of geotechnical engineering tests and principles to high ash sludge landfill
behavior, Andersland (6) observed that sludge permeability progressively de-
teriorated as organic content was decreased from ^3 to 28 percent by removal
of long fibre.  However, over that range of organic contents, sludge perme-
ability was also dramatically decreased by increases in cake consistency.

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 This  parallels  observations with mechanical sludge de-watering that the bene-
 ficial  presence of fibre longer than 100 mesh was diminished as slurry con-
 sistency  was  increased for those sludges high in colloidal content.  Thus,
 sludges become  increasingly impermeable with progressive dewatering or consol-
 idation.  Andersland  (7) also observed that higher sludge solids content re-
 sults in  a  reduced rate of consolidation, thus requiring greater time to reach
 ultimate  settlement.

    Recognizing the importance of sludge cake consistency, the distinction
 needs to  be made between the rate and extent that water can be expressed from
 sludges.  Notwithstanding their lower permeability, high ash sludges also
 exhibit a reduced capacity for retention of water which is attributable to the
 denser, nonporous structure of individual clay particles in contrast to
 properties  of organic components likely to be present.  Laboratory study (IT)
 documents the likelihood of greater filter cake consistencies being associated
 with  higher ash content sludges.  Confirmation is seen in Figure 2 which
 illustrates an  increasing trend of cake consistency with greater ash content
 observed  for  numerous installations employing either vacuum filtration or cen-
 trifugation for the mechanical dewatering of primary sludges (3).  A similar
 observation was made by Mazzola (15) for sludge samples taken from various in-
 depth landfills at nine installations, as shown in Figure 3.  An associated
 observation was that sludge moisture contents had changed very little with
 time.

    Another factor of importance to sludge permeability, but not inher-
 ent with  its  composition, is the presence of minute gas bubbles incorporated
 during  dewatering or entrapped during placement of sludge in the landfill.
 Andersland  (6)  concluded that undissolved gas in the sludge pore fluid was
 responsible for reduced permeability, and, as a result, a certain hydraulic
 gradient  was  necessary to induce flow at low back pressures.  Though the
 effect  of gas bubbles on permeability persisted up to back pressures ranging
 from  60 to  120  ft (see Appendix A, Metric Conversion Table) of water, the mag-
 nitude  of the threshold gradient decreased with an increase in back pressure.
 As an example,  it was reported that for a secondary fibre mill sludge and zero
 back pressure,  this gradient was as high as 1177.  This is of practical sig-
 nificance to the drainage and subsequent consolidation of sludge since hydrau-
 lic gradients in field embankments can be less than one.

 Summary

    The separation of water from paper industry primary sludges is predomi-
nantly a function 'of those factors which determine the size of interstices
available for fluid flow.   As a further analogy, Andersland (6) has cited that
the permeability of pulp and paper-mill sludges is dependent upon the same
variables as those for soils.  These reduce to (a) particle size, (b) particle
size distribution, and (c) the deformability or conformability of sludge fines
as a consequence of chemical composition.

    The  capacity, then,  for sludge solids to dewater or consolidate in land-
fills will decrease as the relative proportions of ash and organic fines
are increased.  Permeabilities are further deteriorated with progressive

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increase in cake consistencies and the presence of entrapped gases within the
sludge interstices.
ENVIRONMENTAL CONSIDERATIONS

     Implicit with the optimization of landfill disposal sites by the applica-
tion of sound engineering principles is consideration of the overall impact
upon the environment.  As a consequence, the potential for intrusion into the
groundwater of constituents associated with the sludge and its subsequent de-
composition warrants attention.  If leachates on a case-by-case basis show a
potential, according to the proposed standards of the Federal Water Pollution
Act Amendments of 1972, for pollution of receiving waters whether ground or
surface, necessary actions should be taken in order to prevent contaminants
from reaching the receiving waters.  The likehood of groundwater contamination
can be compacting the landfill bottom material to a permeability of less than
1.75 x 10"-^ cm per sec or by using a layer of impervious clay or synthetic
material.  In addition, leachates will have to be collected.

Leachate Composition

     Leachates originating within landfills may be characterized as being high
in dissolved solids and chemical oxygen demand (COD) and biochemical oxygen
demand (BOD).  Data contained in Table 5 illustrate leachate composition ob-
served in studies of an experimental high ash sludge landfill in West Carroll-
ton, Ohio (8).

     Leachate constituents present in the greatest quantities are dissolved
organic matter, mineral salts, and those contributing to specific conductance,
and alkalinity.  Alkalinity was consistently greater than total hardness,
indicating that hardness was entirely of carbonate origin.  Consistent with the
buffering capacity associated with leachate alkalinity, pH varied over the nar-
row range of 7.5 to 7.8.  Such a pH is uncharacteristic of domestic landfill
leachates whose acidic nature and lower pH values tend to reduce exchange capa-
cities of renovating soils (18).  Specific conductance values observed in
this study do exceed the single value of 3000 ymho/cm cited by Emrich (19) in
illustrating that parameter as an example of persistence for as long as
20 years of pollution potential of leachate emanating from landfills of
municipal refuse.  Concentrations of BOD, hardness, and dissolved solids,
reported for leachates originating from landfills of domestic refuse, span a
wide range and encompass the values observed in this study (18, 20, 21, 22).
A ratio for BOD to COD of 0.68 was also observed over the duration of the
2-year study.   With the exception cited above, suspended solids did not exceed
160 mg/£, nor was turbidity in excess of 56 MTU.   Considering the origin of
the fill material utilized for this evaluation, it is not surprising that
leachates would be nearly void of organic nitrogen and phosphorus.  In a num-
ber of instances, concentrations of iron and chloride in Samples I through V
nominally exceeded the 0.7- and 181-mg/£ concentrations for those respective
constituents in the in situ sample, suggesting the possibility of some leach-
ing from the drainage beds or, perhaps, a decrease in those residuals by the
conclusion of the study.  Concentrations of nitrogen and phosphorus, as well

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 as  chloride  and  sulfate, are significantly less than reportedly present in
 domestic  landfill leachates.

     Whatever  similarities might be suggested between leachate concentrations
 typical of this  study and domestic landfills, the significant differences in
 the mass  of  constituents discharged is made apparent in Figure U.  The high-
 ash-sludge landfill constituent mass vas estimated assuming a hypothetical
 leachate  strength as great as that represented by the dry weather concentra-
 tions  for the  entire volume displaced.  Representative domestic refuse land-
 fill masses  were estimated based upon data reported by Merz (21}.  Based upon
 those  estimates, the mass of BOD per unit weight of dry solids associated with
 the high  ash  sludge was but 7 percent of that reported for domestic refuse;
 alkalinity approximated UO percent.

     These distinctions between landfills containing paper-mill sludge and
 municipal refuse are advanced only to illustrate that the arbitrary applica-
 tion of regulations developed for municipal sanitary landfills is not war-
 ranted.   Rather, implementation of regulation should reflect what is known of
 sludge composition and associated leachate characteristics.

     The presence of heavy metals and other elements considered hazardous to
 public health  is not characteristic of paper-mill sludges.  With the possible
 exception of  zinc, those compounds are not inherent in the paper manufacturing
 process and  originate as trace components in raw materials.  As a result, they
 appear in only trace amounts in mill sludges, as shown for several mills in
 Table  6.  The  use of zinc compounds as brightening agents for groundwood pulps
 and clays accounts for its occasional presence in more significant concentra-
 tions.  However, the increasing substitution of other brightening compounds
 will progressively diminish the occurrences of zinc in paper-mill sludges.

     The alteration of the composition and properties of a fill's organic com-
 ponents by microbial attack could result in the loss to the leachate of inter-
 mediate metabolic products.  In the case of paper-mill sludge landfills, the
 anaerobic environment, as well as the absence of such supplemental nutrients
 as  nitrogen and phosphorus, significantly retards the degradation of the
 fibrous sludge constituents.  From a survey of literature data on nitrogen and
 phosphorous requirements for cellulose degradation, Springer (23) estimated
 that from 2 to 60 mg of nitrogen and from 1 to 10 mg of phosphorus per gram of
 cellulose were required for cellulose decomposition.  Imshenetsky (2U) has re-
 ported that decomposition of cellulose becomes essentially inactive when
 available nitrogen becomes less than 1.2 percent.

    Paper products have been found virtually unchanged in landfills that had
been completed for 15 to 25 years.   Mazzola's observations of high-ash-sludge
landfills further substantiate the slow rate of decomposition.   On the basis
of photomicrographs of core samples,  fibre contained in samples estimated to
be 10 to  12 years old was nearly indistinguishable from that contained in a
fresh sample.

    The practical consequence of such retarded degradation is  that further
leachate  contamination resulting from fill decomposition would be moderated

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over a protracted length of time.  In addition, the formation and migration of
gases associated with decomposition would be minimized.

Attenuation by Soil Percolation

    The capacity of soil percolation to rapidly decrease the concentration of
potential pollutants has been documented in the literature,  as well as by ly-
simeter work conducted in conjunction with the West Carrollton landfill
study (9)-  Results summarized in Table 7 show the proportion of the applied
constituent mass retained within the 3-ft soil columns over  an approximate
5-month application period at rates approximating field conditions.  Soil
varieties evaluated included sand, clay, and organic loam.   The last was in-
vestigated under aerobic and anaerobic conditions.

    All soil columns exhibited excellent organic removal, though sand appeared
slightly less efficient.  In all cases, an acclimation period was necessary
before highest removal efficiencies were obtained.  None of  the 3-ft soil col-
umns gave any indication that organic removal capacity was becoming exhausted
over the 160-day observation period.  Anaerobic conditions were observed to be
less efficient than aerobic conditions for organic removal.   All soil columns
showed some capacity to attenuate inorganic constituents. However, with the
exception of clay, all columns demonstrated a decreasing capacity to do so
over the duration of the study.

    In all, it was the conclusion of that study that passage of leachate
through a minimal depth of natural soil would render the percolate innocuous.
In addition, the relative impermeability of the high ash sludge and the de-
creasing rate of leachate flow associated with fill consolidation exert a
moderating effect upon the quantity of leachate percolating  to the groundwater.
Impermeability would further minimize rainfall infiltration  of the landfill as
a potential leachate source.  However, in such a case, caution would have to
be exercised to prevent runoff and subsequent drainage into  surface waters.

Summary

    Substances most likely to prove objectionable should high-ash-sludge
leachates become a part of the groundwater would include dissolved organic
matter, mineral salts, and hardness.  Concentrations were within the broad
range of those reported for leachates originating in landfills of municipal
refuse.  However, on a mass basis, leachate constituents associated with the
high-ash sludge were significantly less. (Moreover, sludge composition is such
as not to constitute a hazard to public health.)

    In consideration of alternate approaches to protection of groundwater
sources from the intrusion of leachate constitutents, the demonstrated capac-
ity of soil percolation to effect a degree of renovation equivalent or supe-
rior to conventional treatment technology merits attention.   As such, a paral-
lel exists with the land application of wastewaters, an approach which has re-
ceived national focus as an effluent management strategy.  The suitability of
percolation is advanced contingent upon the existence or provision of a suit-
able soil of sufficient depth and distribution prior to groundwater utiliza-
tion to provide the necessary renovations at anticipated hydrologic conditions,

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      The nature  of  high-ash  sludges  is  such  that  inherent  impermeability
 minimizes leachate  formation.  The opportunity also exists for minimizing  the
 quantity of  leachate  to be renovated by further sludge dewatering  consistent
 with technological  capability.  The  options  available are  sufficient  to justify
 any selection  on a  case-by-case basis as opposed  to a single universal approach
 to  groundwater protection from landfill leachate  intrusion.
 CURRENT  LANDFILL PRACTICE

      Landfill practice can be expected to receive increasing attention of
 regulatory  agencies.  In addition, overall solid waste management will likely
 constitute  a significant aspect of activities carried out under the regional
 planning provisions of the Federal Water Pollution Act Amendments of 1972.
 Commonly encountered requirements for the regulation of industrial process
 landfills have been previously outlined by McKeown (A).  McKeown further stated
 that  restrictions on the siting of landfills are largely oriented toward mini-
 mizing the  potential for leachate contamination of ground and surface waters,
 as well  as  avoiding public nuisance.  Such provisions, for example, manifest
 themselves  as requirements that:

      a.   The disposal site be a minimum of 2 to 5 ft. above groundwater.

      b.   The site be 50 ft. above a floodplain.

      c.   The site be a minimum of 1 mile from a public well.

      d.   The site be at least 300 ft. from watercourse.

      e.   All subsurface conduits be removed (i.e., culverts, gas and water
          lines, etc .) .

      f.   The minimum distance to a highway be 1000 ft.

      g.   The nearest  property line be 20 ft.  from the site.

     A notable distinction between the operating requirements imposed upon
municipal sanitary landfills  and those of paper-mill  origin is the necessity
for daily application  of  cover material.   In the former case, compaction and
daily cover is necessary  for:

     a.   Controlling  the  breeding of vermin.

     b.   Discouraging  the entrance of rodents.

     c.   Preventing scavengers from feeding upon the  wastes.

     d.   Control  of gas movement.

     e.   Retarding rainfall infiltration  of the fill.

     f.   Prevention of fire.
                                      10

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     It is evident from the composition of and known behavior of paper-mill
sludges that such latter precautions are unnecessary.  Moreover, their proper-
ties are such that they have an inherent ability to fulfill many of the func-
tions required of the cover material.  Not only are paper-mill sludge landfills
normally exempted from daily cover requirements, the precedent exists for
their being utilized as a daily cover for sanitary landfills.

     Prior to the issuance of a permit for operation of an industrial solid
waste disposal system, a number of states require that the entire waste
management plan be reviewed for conformity to sound engineering practice.
Examples of provisions for design and operation that have been advanced for
inclusion in plans requiring regulatory agency approval are as follows:

     a.  General:  Map or aerial photograph of the area showing land use and
         zoning adjacent to the proposed disposal operation.  The map or aerial
         photograph should show all homes, industrial buildings, wells, water-
         courses, dry runs, rock outcroppings, and roads.  General topography
         should also be identified.

     b.  Geological Considerations:  Geological examination of the proposed
         area is a useful adjunct to siting.  Soil borings of sufficient num-
         ber and depth should be taken to provide a subsurface investigation
         representative of the entire site.  Such tests are made to determine
         the porosity and permeability of the soil in the landfill area.  Sites
         with low permeability are usually preferred.  General path and rate
         of flow of groundwater flow should be estimated.

     c.  Groundwater Testing:  Both the level and quality of groundwater are
         determined using test wells or pits.  Sampling to include seasonal
         variation is suggested.  (Test wells can later be used to check
         groundwater quality after site is operative.)  Wells are usually to
         be placed upstream and downstream of the projected groundwater flow
         pattern at varying levels.

     d.  Rivulet Diversion:  The impact of the fill upon area drainage patterns
         should be considered.  Natural drainage paths may be rerouted, or in
         some cases covered and protected from landfill runoff.  Natural
         springs may also require rerouting.  Surface drainage from the com-
         pleted fill should also be considered.

     e.  Development of a proposed plot plan of the site showing dimensions,
         location and ground surface elevation of soil borings, original and
         proposed final land contours, proposed trenching plan or original
         fill face, existing and proposed drainage patterns, access roads and
         any fencing.

         (1)  Fencing should be considered if site is near public roads or
              population and open to easy access.  Lighting should be considered,
              especially if nighttime delivery is planned.

         (2)  Roads should be planned based upon the expected life of the site
              and types and loadings of trucks and frequency of delivery.  If

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            traffic routes include public roads through populated areas, some
            thought is usually given to scheduling vehicles to provide minimum
            neighborhood disturbance, especially when steep grades are in-
            volved.  The potential for erosion and dust problems within the
            landfill site warrant attention.

        (3) Final Grade:  Consideration should be given to planning for future
            use of the land after the site has consolidated naturally.

    f.  Equipment and Operational Reqairements:   Heavy duty dump trucks and
        spreading equipment are necessary.   The amount of sludge and size of
        storage pads will dictate the type.3 and sizes of trucks to be used.  A
        number of mills store sludge for delivery during daylight hours.
        Storage is usually upon a concrete apron protected from receiving ex-
        cessive rainfall.  Front-end loaders  are used to clear the apron into
        trucks during daylight.  Storage volume should be designed to accumu-
        late sludge during particularly inclement weather.   Snow removal and
        road clearance equipment are obvious  requirements in cold climate.

    g.  Thought should also be given to development  of such information as
        sludge composition, moisture content,  anticipated quantities, degrad-
        ability, and potential leachate properties.

    Implicit in fulfilling a number of the  previously cited considerations  is
a knowledge of the rate and extent of landfill consolidation and behavior.
                                     12

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                                  SECTION II

                             RETAINING STRUCTURES
    The basic objective of engineering sludge disposal landfills is to com-
press (consolidate) and confine the material and stabilize its behavior.   By
consolidating the material, its strength is increased many times and it be-
comes a stable solid that will stand as an embankment.  The available landfill
volume will be increased by the difference between the volume of freshly
placed sludge and the amount of consolidation, and by the ability to construct
high mounds of consolidated material.
NEED FOR SLUDGE CONFINEMENT MfD SURCHARGE

    In order to best achieve the objective, the sludge material must  be  con-
tained and physically consolidated.  Temporary dikes are required to  laterally
contain the material, and surcharge loads are required to induce consolidation
by forcing water from the material.  Surcharge loads are necessary for two  im-
portant reasons:

    a.  Sludge has a tendency to hold or retain water because of its  composi-
        tion and may be only slightly free-draining (6, 9,  15).  Therefore,
        surcharge loads are required to sufficiently increase the water  pres-
        sure internal to the sludge material such that the  water will flow  out
        from the material.  This dispersion of water will therefore allow the
        material to consolidate to a lesser volume.  The decrease of  volume is
        approximately equal to the volume of water dispelled.

    b.  Surcharge loads accelerate consolidation, thereby significantly  de-
        creasing the time required for a given total consolidation to occur.
        Pulp and paper-mill sludge is similar to an organic soil called  peat.
        For some peats, the time for consolidation has been shown to  be  accel-
        erated by surcharge, by a factor of thousands (25).  For example, a
        10-ft-thick layer of peat that would take 30 years  to consolidate
        could theoretically be consolidated in 10 days by the proper  use of a
        surcharge load.

    Because of the initial high water content and low strength of fresh  sludge,
the initial surcharge thickness probably should not exceed  about 3 ft.   (This
recommendation is based on field experiences with peat discussed in Refer-
ence 25.)  Greater initial thickness may cause failure of the sludge  from a
shear strength and bearing capacity (ability to support load) consideration.
If, when placing the 3 ft of surcharge, lack of the sludge  material to support
it is evident, the surcharge thickness should be reduced to a supportable
                                      13

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amount.  However, some type of membrane or mat may be used to supply support
without reducing thickness of the surcharge.   (Membranes are discussed under
Suggested Construction, page 22.)  If greater surcharge thickness is desired
in order to induce a larger amount of consolidation and/or further decrease
the time element, the following recommendations are made:

    a.  Bearing capacity of the sludge material should be checked (25, 26,
        or 27, or 28).

    b.  Application of the surcharge could be made in stages (layers) if the
        sludge-bearing capacity is not sufficient.  Between each stage, time
        (weeks) should be allowed to elapse such that an amount of consolida-
        tion would occur-  Consolidation causes the material to increase in
        strength, thereby allowing it to support greater loads.  Therefore,
        each increment of consolidation between surcharge stages increases
        the strength for the next load.  (Calculation of consolidatio and
        time rates will be covered under Consolidation, Settlement,  and Slope
        Stability, page 2U.)

    c.  A membrane or mat could be used to increase the sludge supporting
        ability, thereby allowing greater surcharge loads.   Obviously, a
        membrane or mat could be used in conjunction with stage construction.

The economics involved with the use of greater surcharge loads should be
balanced against the benefits gained from increased usable landfill  volume
and accelerated consolidation time.  The most economical material to use
for the dikes and surcharge loads would be earth material existing at or
near the landfill site.
DRAINAGE

    Drainage is a highly important  factor that  must be considered for the  fol-
lowing reasons:

    a.  A large volume of water will be forced  out  of the sludge material.
        The sludge and water will be contained  within the dike-enclosed area;
        therefore, adequate drainage of the water from the enclosed area must
        be accomplished.

    b.  The time rate of consolidation is theoretically related to the square
        of the shortest drainage path through a material.  Therefore, by ade-
        quately controlling the distance or thickness through which a mate-
        rial must drain,  the consolidation time can be accelerated by a fac-
        tor of hundreds.   For example, a material of constant properties that
        is drained through a 10-ft  thickness could  theoretically have its  con-
        solidation time accelerated by a factor of  UOO if it  was  drained
        through two 5-ft  thicknesses.   In other words, if the 10-ft  drainage
        path resulted in 30 years for an amount of  consolidation  to  occur, the
        5-ft drainage paths would allow the same consolidation to  occur  in
        27 days.
                                      Ill

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    In order to accomplish drainage from the enclosed area and to accelerate
consolidation, drainage "blankets should be utilized.   If contamination of the
groundwater could "be a problem, appropriate action should be taken (discussed
previously on page 9).  The drainage blankets should consist of clean sands
and/or gravels and should be about 1 ft of uniform thickness extending over
the entire enclosed dike area.  Outlets through the dike for the drainage
blankets must be provided.  A water collection pocket about 3 to h ft long
consisting of gravel, intersecting each drainage blanket, and tapped with a
pipe no smaller than 6 to 8 in. should provide adequate drainage.  Drainpipes
should extend out from the dike a sufficient amount so that discharge will not
erode the dike.  The drainage blankets should be placed in the bottom of the
enclosed fill area (if the elevations are such that it will drain the enclosed
area), not less than every 8 to 10 ft of fresh sludge material, and at the top
of the fill prior to placement of the surcharge load.  If no drainage blanket
can be used at the bottom of the fill, the first blanket should be about 5 ft
above the bottom of fill.  The above-mentioned drainage blanket spacings allow
vertical drainage paths of about U to 5 ft in each sludge layer.

    Shown in Figure 5 is a cross section of a dike and a portion of sludge
fill illustrating the use of a dike, drainage blankets, water collection
pockets, drainpipes, and surcharge load.  If the landfill site has a solid
foundation (such as an old rock quarry) so that deformation or consolidation
beneath the sludge fill will be negligible, the middle drainpipe of Fig-
ure 5 could be eliminated.  However, the middle drainage blanket would have
to be connected to the lower blanket.  This connection could be made by a
5- to 10-ft-wide by 1-ft-thick layer of sand or gravel on the dike slope.
The full surcharge load should not extend to the dike, because the less
thick sludge on the dike slope will consolidate more than that away from the
slope.  Water from the fill area can be channeled or collected from the
drainpipes and disposed of as necessary.


POSSIBLE PLAN FOR LANDFILL AREAS

    Assume that a large landfill site is available and that several confine-
ment areas are required to cover it.  One possible system of progressively
constructing and filling enclosed areas is presented in Figure 6 with the
following recommendations:

    a.  In order to adequately maintain drainage of each new enclosed area,
        the areas should start in the center of the landfill site and
        progress outward.

    b.  New enclosed areas adjacent to old ones should have their drainage
        blankets connected to the older area ones.  This connection can be
        either a direct intersection in the case of the older dikes being
        removed or through the existing drainage pipes in the case of the
        older dikes not being removed.  Drainage of the older fill areas
        should be allowed to continue, because of slow continuing consoli-
        dation or new consolidation induced by sludge being placed on top
        of the old.
                                      15

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     c.   After the sludge consolidation  of  an  enclosed area, the  earth dikes
         may or may not "be removed.  The choice of removal should be based
         on an economic consideration  involving the following factors:

         (l) Availability and  cost of  earth materials for new dikes.

         (2) Cost  of removing  old dikes  and constructing new ones from the old
             materials  versus  using new  materials.

         (3) The sludge fill volume gained  by  removing the dikes.

     d.   The choice of  removing  and reusing surcharge material after sludge
         consolidation  should  be based on economic factors similar to the
         preceding ones.   However, if  fresh sludge is to be placed on top of
         consolidated sludge,  part or  all of the existing surcharge materials
         may be desired as a supporting  surface for construction  equipment
         and trucks.  The need for a supporting material would depend on the
         strength  (ability) of the consolidated sludge to support the
         equipment.   If the surcharge  material is removed and supporting
         material  is  needed for  equipment,  an  earth material road could be
         placed on the  consolidated sludge.

     e.   If surcharge materials  are removed, the top drainage blanket mate-
         rials may also be reused for  another  area.  The cost of  sand or gravel
         drainage  materials may  justify  removal of the surcharge  loads.

     f.   If sludge disposal is to continue  upward, the surcharge material may
         be used for  constructing the  new enclosing dikes after consolidation
         of the lower sludge.  The top drainage blanket then becomes the bot-
         tom drainage blanket  for the  fresh sludge.  An upper disposal area
         should not begin until  at least  adjacent lower areas have been filled
         and partially  consolidated.

As  can be  seen in Figure 6, planning  the arrangement and construction sequence
of  enclosing areas results in only one  dike side needed for some areas.  Plan-
ning  also  results in efficient  use and  reuse  of materials.


 CONSTRUCTION CONSIDERATIONS

    Enclosed area dimensions, dike construction, and sludge placement methods
will be  directly  controlled by  the consistency of the sludge material.  For
convenience,  sludges will be  divided  into  two very general behavior catego-
ries:  fluid behavior  and plastic behavior.  A fluid-type sludge will tend to
flow in  a viscous  slurry when unconfined.  A plastic-type sludge will not flow
but will form a self-supporting mound when unconfined and will have a dry
appearance.

    Fluid and semiplastic type  sludges will limit one of the enclosed area di-
mensions because  they  will have to be spread and leveled with a crane dragline
or similar  equipment working  from the dike.  Drainage blankets and probably
the surcharge material will also have to be spread with the dragline due to


                                      16

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the sludge not being able to support equipment.  One dimension of the enclosed
area must be limited to twice the working length of a dragline.  (The average
dragline working length is about U5 to 50 ft.)  This limit will allow a drag-
line to reach the center of the area from either of two dike sides.   The limit
dimension of 90 to 100 ft is measured from the inside edges at the top of the
proposed dikes.  An inside dike slope of ^5 deg (l:l) is a good inclination
angle for design and construction.

    An enclosed area does not have to be a square; it could be rectangular
or any other shape.  However, the above-mentioned limitation specifies that
the shortest dimension be about 50 ft from the center to a dike side.   A
rectangular area would be limited to about 100 ft in width but could be any
length.  Due to the deficiency of knowledge and experience concerning the
plastic-type sludges and knowing they are initially low in strength, the
above-mentioned limitation  seems  reasonable  for  all  sludges.   If equipment for
placing plastic sludge cannot operate directly on the fresh material,  a drag-
line from a dike side would have to be used.

    Assume here that sufficient earth materials for the dikes and surcharge
loads are available at the landfill site.  If the area to be enclosed does
not have an approximately level surface, some material for the dikes can be
obtained by leveling the area with a bulldozer.  The area can also be exca-
vated to obtain dike and surcharge materials.  However, excavation should not
be so deep that water would not drain from the bottom or first drainage
blanket.  Further assume that the site has now been prepared consistent with
the discussion on page 16 and the bottom drainage blanket (if there is to be
one) and drainpipes have been placed.

    With the assumptions above and for a fluid-type sludge, the following sug-
gestions for possible construction are made:

    a.  Begin the earth dike construction by bulldozing a U- to 5-ft height
        around the sides of the fill area, maintaining the design enclosed di-
        mensions and slope.  Some compaction of the dike material is achieved
        from the tractor.  The outside dike slope could be as-constructed but
        with a section of low inclination angle in order to allow a ramp for
        equipment and trucks to get to the top of the dike.  If sludge is to
        be brought in by trucks, an opening in the dike could be left on one
        side for the trucks.  The trucks could also dump from the dike, or the
        sludge could be piped into the fill area.  Care should be taken not to
        disrupt the bottom drainage blanket.   A dragline, working from the
        dike sides, would be needed to spread the sludge.

    b.  With the first ^ to 5 ft of sludge in place, a drainage blanket and
        drainpipes would be needed if they were not placed at the bottom.
        (However, assume they are at the bottom.)  The dike construction could
        now continue for another h to 5 ft in height, and it could be widened
        as necessary to provide a convenient width for equipment.  Sludge
        would now be placed again by truck or pipes and spread by the dragline,
        The operations would continue until a sludge design thickness was
        reached, at which point another drainage blanket would be required.
                                      17

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    c.  The  sludge surface should be approximately level, and this could be
        done by the dragline pulling a raft across the surface.  A raft could
        be made by lacing together several logs, poles, pipes, etc.  The
        gravel drain pockets, drainpipes, and drainage blanket should now be
        placed.  Depending on the strength of the sludge, the following pro-
        cedures could be used for placing the drainage blanket:

        (l)  If the sludge would support the drainage blanket material plus a
             small lightweight tractor with extra track width, the blanket
             could be placed by the tractor spreading material ahead of itself.

        (2)  If the sludge would support the drainage blanket only, then the
            material could be placed, spread, and leveled by the dragline.

        (3)  If the sludge would not support the drainage blanket, some kind
            of porous membrane or mat for support would have to be used on
            top of the sludge.  Drainage blanket material could then be placed
            by the above-mentioned methods.  Porous membranes are materials
            such as burlap, wire mesh sheets, special plastic sheets (such as
            in Reference 29), possible porous paper sheets,  etc.

    d.  Construction of the fill area should continue for the upper sludge
        layers as in the previous steps.   At the top of the  fill, a drainage
        blanket and surcharge must be placed.  Methods for placing these
        would be the same as in c, above.   Figure 7 illustrates,  in general,
        the above-suggested fill area construction steps.

    For a plastic-type sludge, construction of an enclosed fill area may be
simpler.  The above-mentioned steps should be followed in general.   However,
if a lightweight tractor can operate on top of the sludge, placement could be
made with the tractor and in thicker layers.   Also, if a tractor  could be
used,  no problems would occur in placing  drainage blankets and surcharge
loads.  If the sludge will not support a  tractor, then the construction steps
for a  fluid-type sludge would have to be  followed.
                                     18

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                                  SECTION III

                CONSOLIDATION, SETTLEMENT, AND SLOPE STABILITY
CONSOLIDATION THEORY

    Pulp and paper-mill sludge consists of solid constituents between which
are spaces (voids) filled with air or water.   The void space of the sludge in
the fill (or, in another sense, the sludge density), the amount of water con-
tained in the void spaces (water content), and the sludge permeability are of
concern, because these affect the strength and settlement (vertical displace-
ment) of the sludge.  Figure 8 is a summary of weight and volume relations
for a sludge sample.  Appendix B presents the laboratory test procedures for
determining- the physical properties necessary in understanding and predicting
the behavior of sludge.

    Most sludges will be 100 percent saturated (all void space filled with
water).  If a saturated sample is subjected to a one-dimensional load (Fig-
ure 9), the decrease in volume is accomplished by water being squeezed from
the voids at a rate controlled by the sludge permeability.   This process is
termed consolidation.  The change in height,   AH , per unit of original height,
H , equals the change in volume,  AV ,  per unit of original volume,  V .
                                   AH

                                   Hl
AV
V,
AV  can be expressed in terms of void ratio,  e ,  and  AH  becomes
                       AH = H.
                                  Ae
                             1 \1 + e.
= H,
       P  — P
      •  1    2'
This relation is for primary compression, which is due entirely to the de-
crease of water volume.  Secondary compression occurs after primary compres-
sion and may be related to a plastic creep deformation and compression of the
constituent particles.  The rate of consolidation can also be calculated.  The
prediction of the rate of consolidation usually has the largest error because
of changing consolidation parameters, secondary compression, and construction
rate (increasing load rate).  Detailed discussion of consolidation theories
can be found in References 7-9-  Stress-strain characteristics of sludge can
be determined in the laboratory (Appendix B) and applied together with the
consolidation theory to predict sludge settlement and rate for landfills.
                                      19

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 SETTLEMENT  PREDICTION

 Vertical  Stresses

     The vertical stress acting on a horizontal plane at depth,  s  , is equal
 to  the weight  of all matter that rests above the plane,.  If the unit weight of
 the matter  is  constant with depth, the stress at depth,  z, , is equal to the
 depth multiplied by the wet unit weight,  Ym  (Appendix B, Unit Weights).  A
 load-depth  diagram is usually constructed by plotting stress versus depth as
 in  Figure 10.  The total initial stress,  Po , at any depth may be obtained
 from the  diagram.  Sludge materials have extremely high water contents and
 large volumes  of water.  When placed in a contained landfill, a pond of wa.ter
 is  essentially created and the sludge constituents are held in suspension.
 The water exerts a hydrostatic pressure,  u  (Figure 10), as a. function of
 depth, on the  sludge constituents.  As a result of the hydrostatic pressure,
 the effective  contact stress,  P'Q , between sludge particles is reduced by the
 magnitude of   u  (Figure 10).  In other words, the sludge particles support a
 load of   P0 -  u  only.  The average vertical stress within a layer acts very
 close to  the middepth of the layer; therefore,, it may "be taken at the middepth
 point with  negligible error (about 10 percent).   In Figure 10, the average ef-
 fective stress in the sludge layer is  PQ = 138 Ib/ft^.  In Figure 11, if a
 load AP  is added to the sludge layer of Figure 10, the resulting effective
 stress is  P^  + AP , and the average stress is P' = (138 + A.P) lb/ft2.

 Settlement
     Once data from laboratory tests (Appendix B) and from stress analysis
 are  available, the settlements for a landfill design can be easily obtained.
 In order to make settlement computations, a landfill design height and the
 number of layers should be selected,,  From the laboratory tests, sludge wet
 unit weight,  Ym , has been determined and the a.verage initia.1 effective
 stress,  PQ , for each design sludge layer can be calculated.  The total
 load,  AP , above each sludge layer can now be calculated (for sand,
 Ym ^ 100 lb/ft-3; for surcharge,  ym ^ 120 lb/ft3).  Total load,  AP , equals
 the wet weight of all sludge, sand, and surcharge layers above the one being
 considered.  The primary settlement,  AH  •  , for a sludge layer is computed
 by the equation
where  AH  .  = primary settlement
         pri
          C  = compression index determined from laboratory tests (Appendix B,
               Consolidation Test), Plate B-13.  (if the laboratory pressure-
               void ratio plot is curved and  P'  corresponds to a laboratory
               pressure in the curved region,  Cc  should be taken as the
               tangent at the point  P ^ P' .)

          H  = total initial thickness of the sludge layer.   In Figure 11,
               Ht = 2H


                                      20

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          eQ = initial void ratio existing at  P^ , obtained from laboratory
               tests (Appendix B, Consolidation Test), Plate B-13.

          P^ = average initial effective stress within the sludge layer, as
               previously described

          AP = total load above the sludge layer, as previously described

To compute settlement from secondary compression following primary consolida-
tion, use the following equation:

                                              t
                                 = C H.  loe_.
                             sec
                           AH    = C H. logn . T
                                    a t   to!0 t
                                               pri
where  AH    = settlement from secondary compression

          C  = coefficient of secondary compression obtained from the labora-
               tory tests (Appendix B, Consolidation Test) (Plate B-12) for
               the total laboratory load increment corresponding to  P'  in
               the field

        t    = time for which settlement is significant
         sec                                  °

        t   . = time to completion of 100 percent primary consolidation
For one cycle of log time
                           AH    = C H.  log,..
                             sec    a t    10

                           AH    = C H,
                             sec    a t

Total settlement is equal to

                           AH  _,_ , = AH  .  + AH
                             total     pri     sec

    If sludge materials having largely different compression indexes are
placed within a layer, the settlement of the total sludge layer can be cal-
culated by the following equation:

                                                          n
            AH^ ,  .  = AH,      + AH0     . . . + AH       = Y AH
              total     1,  ,  .      2             n,  ,  ,    i    n
                         total      total         total   1


where  n = individual layers of different sludge within a single layer of
           sludge

    Time rate of settlement is computed by the following equation for
primary consolidation:
                                      21

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                                         TH2
                                   pri ~ C
                                          v

 where  t    = time for primary consolidation in the field
        pri
          T = dimensionless time factor related to the percentage,  U , of
              primary consolidation.  Figure 12 is a curve for  T  versus  U
              from which values of  T  can be obtained

          H = length of longest vertical path for drainage of water.  For
              drainage to pervious layers at top and bottom of the sludge
              layer,  H = Ht/2 .  For drainage to only one pervious layer,
              H = Ht

          C  = coefficient of consolidation determined from the laboratory
          V   tests (Appendix B, Consolidation Test) (Plate B-12) for the
              total laboratory load increment corresponding to  P'  in the
              field.

    Primary settlement time rate,  tpri , can also be determined from the
 nomograph in Figure 13.  Figures 12 and 13 correspond to instantaneous load
 applications .

    If load  AP  application is gradual and construction time is appreciable
 compared  with time required for primary consolidation, the time factor curves
 of Figure lU should be used to obtain the  T  values for the field time,
     5 equation.  (Figure l.k is strongly recommended to be used at all times.)
 In Figure 1^ ,  T   is determined from
                o
                                       C t
                                  T  =
                                        H2

where  to = end of construction time .   to  can be estimated from the volume,
Vf  , of the landfill and the pulp and paper-mill sludge production rate,
Vs/day                               y
                                to = ~  in days
                                      s

T  and  U  during construction (prior to  to )  are given by the upper envelop-
ing dashed curve to the point of calculated  To .  After the end of construc-
tion time  to ,   T  and  U  are given by the dashed curve corresponding to
TO •

    The time for secondary consolidation is  tsec , as defined previously.
If one cycle of  log time is used for computing  AHsec ,  tsec  = 10 x

    The time for total settlement to occur is

                       t      = t                + t
                        total    100 percent pri    sec
                                      22

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where            t  ,  ,  = time for total settlement to occur
                  total

       t              .  = time for 100 percent primary settlement to occur
        100 percent pri

                        = chosen time over which to compute the amount of
                          secondary settlement

For a layer of sludge with materials having largely different coefficients of
consolidations, use an average  Cv  for the time computations.   Settlement
time plots (Plate 1 is a suggested form) should be made for the sludge layers
of a landfill.  The curves will show the importance of time and will indicate
when retaining dikes could possibly be removed.  Dikes can be removed after
about 90 percent total settlement has occurred.

Possible Errors
    Sources of error for both consolidation and time rate predictions are
listed below.

    a.  Nonrepresentative laboratory specimens.

    b.  Inaccurate laboratory data.

    c.  Nonhomogeneous sludge material within the layers.

    d.  Decreasing coefficient of permeability with consolidation.

    e.  Construction rate cannot be accurately considered.

    f.  Inaccurate load estimate,  AP .   The actual thickness of the layers
        will vary from design, because the lower layers will consolidate  as
        the upper layers are constructed.  Therefore, greater thickness of
        upper layers will result.

    g.  Change in sludge material properties as a result of construction  and
        consolidation.


SLOPE FAILURE CONDITIONS

    After consolidaton of the sludge layers in a dike-enclosed area, the  dikes
may be left in place or removed.  If the dike material and the dike-occupied
space are not needed for continuation of sludge disposal,  they may remain per-
manently and eventually be covered with sludge.  However,  if the space occu-
pied by the dike and the dike material are required for landfill continuation,
the stability of the consolidation sludge upon removal of the dike will have
to be considered.  Three approaches may be taken:  (a) the sludge may be  al-
lowed to form a natural slope, (b) a slope having an angle of U5 to 50 deg may
be cut, or (c) a slope may be designed to prevent movement and breaking off  of
material.

    When landfill interior dikes are removed, sludge will be placed against
                                      23

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 the natural  or  cut  slope;  therefore, the sludge material that may have  fallen
 will not  be  a problem.   If dikes along a landfill periphery are removed,  safe
 slopes  should be  designed.  When sludge disposal is to continue upward, the
 upper dikes  should  not be  so close to a lower layer sludge slope as to  cause
 failure.   Slope stability  should be checked in order to design a safe distance
 between an upper  dike and  a slope.

      Failure of a slope  or embankment is the rapid or gradual displacement of
 a portion of the  embankment relative to the remainder of the mass.  The por-
 tion that moves may do so  as a slide, a rotation, or a displacement of  a wedge
 shape.  Failures  follow  changes in shear stress or shear strength that  lead to
 unbalanced driving  forces.  Imbalance of forces is caused by changes in slope
 profile,  increase in water pressure, added weight to the top of the slope, or
 time-conditioned  decrease  in shear strength due to weathering, leaching, miner-
 alogical  changes, opening  and softening of fissures (cracks), or continuing
 gradual shear strain.  The possibility of movement occurring is evaluated by
 comparing forces  resisting failure with those causing failure.  This ratio is
 the safety factor.

 Slope Design Considerations and Stability Analysis

      Because of the sand drainage blankets between sludge layers, failure is
 most  likely  to  be in the form of a wedge of sludge material displacing with
 translational motion along or through a sand layer.  The slip or failure sur-
 face  will be a  composite slip surface through the sludge and along the sand
 layer.  Analysis  of a failure of the above-mentioned type can be made using a
 procedure of slices and  a composite slip surface (8).  The analysis method
 presented below is  based on total stress and not on effective stress, because
 pore  pressures  within sludge will not be known.

      In order to  design a safe slope, a slope angle is assumed and the minimum
 factor  of  safety  is calculated.  The procedure is repeated for other assumed
 slope angles until  a satisfactory or design factor of safety is acquired.
 Once  the  design factor of safety is obtained, the corresponding slope angle is
 the angle  at which  the sludge slope should be cut.  Because the analysis pro-
 cedure  is  based on  total streases, a minimum design factor of safety of about
 1.5 for landfill interior sludge slopes against which sludge will eventually
be placed  seems reasonable.  A minimum design factor of safety is the value
at and below which a failure might possibly occur.  For landfill periphery
sludge slopes which should have a long duration and because of total stress
analysis,   the design factor of safety of about 2.0 seems reasonable.


     Design and analysis procedures for consolidated sludge slopes are as
follows:

     a.   Choose a trial slope angle, 3, as shown in Figure 15.   A $ between
         45 and 50 deg would be a good starting point.

     b.   Choose a trial slip (failure)  surface such as  trial  1  in Figure 15.
         Because total stress analysis is being used and the  sludge material  is
         initially undrained when a slope is cut, the sludge  angle  of  internal
         fraction, cj>,  is equal to 0.  Therefore, the slip  surface through  the

                                      2k

-------
    sludge layers can always be taken at an angle  a  = ^5 deg.  The slip
    surface angle through the sand layers and through the surcharge mate-
    rial is  ct]_ = ^5 deg + /2 .   A good approximate friction angle,  $ ,
    for the sand and surcharge is  <|> = 30 deg; therefore,  a  = 60 deg.

    For the trial 1 slip surface, there is no angle  013 .  However, for
    the other trial slip surfaces shown,  a-?  and  ct^  are determined (as
    shown in Figure 15) "by the location of the trial slip surfaces through
    the sludges.

c.   Divide the sliding mass into slices.  For convenience, the slices can
    "be taken at points separating zones of different material properties
    or at points where a break occurs in the upper or lower boundary of
    the sliding mass as shown in Figure 15.

d.   Set up a table as shown below and fill it in (8).

                            Tabular Computation

                Values from the Cross Section     Computed Values
         Slice           Ax    P    Sy     *     B    A'    N    A
          No.   tan a    ft   psf   psf   deg     o    o     a    o

           1
           2
           3
           k
         Note that   a = angle at base of slice

                    Ax = slice width, ft

                     P = average vertical total stress on base of
                         slice (ym x depth to center point of
                         slice base).  Ym  (Appendix B, Unit
                         Weights) average for each sludge layer
                         can be obtained from the average water
                         content,  wavg  (Appendix B, Solids and
                         Water Contents) for each layer as
                 ,      - \ j_ .  w   /  i        ,
                  m            avg  I        1
                   avg              \w    + —
                     &              » avg   G
                                             Sy

                    G  = specific gravity of solids (Appendix B,
                         Specific Gravity).  The average water con-
                         tents can be determined from the material
                         adhering to the vane shear test device
                         (Appendix B, Vane Shear Test).  The
                                  25

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                             equation above assumes 100 percent satu-
                             ration of the sludge.

                        S  = S       (Appendix B, Vane Shear Test)
                               vane
                             x y = average undrained sludge shear
                             strength at base of slice.  M = correc-
                             tion factor from Figure l6.

                          = angle of internal friction for the sand
                             and surcharge

                        B  = P x tan a x AX
                         o
                        A1 = Sy x AX  for sludge base.  A^ = P x tan <|>
                         0   x AX  for sand and surcharge base

                        N  =1.0 for sludge base
                         a
                                2   /n    tan a tan d> \
                        N  = cos  a 11 +	-I  for sand and sur-
                         a          \         F     /
                             charge base

                             A'

                        Ao = ~
                              a

                        Calculate the summations of the  Bo  and  Ao
                        columns,  VB   and  VA
                                  f-> O       L* O

    e.  Calculate the factor of safety,  F , by successive approximations
        or by solving for  F  in the equation

                                         A
        Successive approximations or solution for  F  are required, because
        F  appears on both sides of the equation above.

    f.  Repeat steps b through e taking different trial slip surfaces until
        the minimum factor of safety is found for trial slope angle  3 .

    g.  Choose other trial slope angles,  3 , and find their minimum factors
        of safety by steps a through f.

    h.  For interior landfill sludge slopes, the  g  with a corresponding  F
        greater than 1.5 vould be a good design slope.  For periphery landfill
        sludge slopes, the  3  with a corresponding  F  about 2.0 would be a
        good design slope.

The field experimental example presented in the next section should help
clarify some of the procedures described above.


                                      26

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                                  SECTION IV

                          FIELD EXPERIMENTAL EXAMPLE
RETAINING STRUCTURES AND SLUDGE PLACEMENT

    An experimental paper-mill sludge landfill was constructed and monitored
during the period 1971-1972 (6-9, 30, 31) to obtain engineering information
essential to developing procedures for the design and operation of pulp and
paper-mill vaste landfills.  The work was sponsored by the EPA and NCASI.
Kimberly-Clark Corporation-Morraine Mill, West Carrolltori, Ohio,  provided  the
landfill site and dewatered sludge.  The landfill site was an old gravel pit
near West Carrollton,  The experimental fill consisted of two sludge layers,
initially 10 ft thick, with 1-ft-thick sand drainage blankets at  the top,
middle, and bottom.  An earth dike provided lateral confinement of the  sludge,
and a surcharge load consisting of 3 ft of natural soil was used.   A lysimeter
study provided information on changes in quality of the leachate  when passed
through selected natural soils.  Figures 17 and 18 show the landfill in a
plan view and typical cross section, respectively.

    For the dike construction, a 35-ton Link Belt power shovel was used for
the excavation work and a D-6 Caterpillar tractor was used to move the  exca-
vated earth material and shape the dikes.  The dike sides were constructed
with one corner left low for placing sand in the fill bottom.  After spreading
sand for the lower drainage blanket, the dike was closed and sludge was dumped
from trucks over the west and south dike walls.  Even though the  sludge exhib-
ited a plastic behavior, it would not support the D-6 tractor-   Therefore, the
power shovel was converted into a dragline unit and proved ideal  for spreading
the sludge.  A lightweight tractor with extra-wide tracks was obtained, but it
arrived too late for use in spreading the lower sludge layer and  because the
dike had been fully constructed, it was not used for the upper sludge layer -

    When the lower layer of sludge was sufficiently thick, it was leveled  with
the dragline by dragging two telephone poles cabled together across the sur-
face.  Sand for the middle drainage blanket was then dumped along one dike
wall, distributed by the dragline, and leveled with the dragline/telephone
pole arrangement.   The lightweight tractor was not used with the  middle sand
blanket because the dikes had been completed, and manuevering the tractor  in
and out of the field would have been difficult.

    When the upper sludge layer reached the desired thickness, it too was
leveled by dragging the telephone poles.  Sand was dumped along one dike wall
and was spread by the lightweight tractor pushing the sand ahead of its path.
Because the sand acted as a supporting mat, the small tractor had no diffi-
culty in working on the landfill surface.  Sand placement with the small
                                      27

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 tractor was faster than with the dragline.   Both the  D-6 and small tractor
 vere used for spreading the earth surcharge material.   The surcharge material
 was dumped onto the landfill surface by the dragline.
 SLUDGE MATERIAL

     The dewatered sludge used in the  landfill  had  the  physical  properties
 shown in Table 8.   These properties were  determined  from  samples  taken  at
 various elevations as the sludge was  placed; determinations were  made in ac-
 cordance with the tests  described in  Appendix  B.   Therefore,  the  properties
 represent the initial, as-placed sludge conditions.
 CONSOLIDATION AND SETTLEMENT

     Figures 10 and 11 give  the  initial  average  effective  stress,  P'
 = 138 lb/ft2 (discussed in  Section  III)  for  each 10-ft-thick  layer.   The  total
 load acting on the lower sludge layer,   AP]_Ower 5  is  calculated as  follows:

     a.   Weight of sludge (design thickness)  above  lower layer
         = 10 ft x 70  lb/ft3 = 700 lb/ft2

     b.   Top sand layer weight = 1 ft  x  100 Ib/ft3  = 100 lb/ft2

     c.   Surcharge weight =  3 ft x 130 lb/ft3 =  390 lb/ft2

     d.   APlower = (700 + 100 +  390) lb/ft2 = 1190  lb/ft2

     e.   Average effective stress  P'     = P' + AP_,     =  (138 + 3190) lb/ft2
                                    lower    o      lower
         = 1328 lb/ft2 = 0.66^ ton/ft2 ~ 0.66k kg/cm2

 The  total load acting on the upper  layer,  APIlpper ,  is the weight  of the sand
 blanket  and surcharge.   The sand  blanket weight is included in  P^  „  There-
 fore,  APupper =  3  ft x 130 lb/ft3  =  390 lb/ft2 =  surcharge weight  .  The av-
 erage effective stress  is   P'     - P1  + AP      - (138 +  390) lb/ft2
                             upper    o   " upper           y  '   '
 =  528 lb/ft2 = 0.261*  ton/ft2 «  0.26U  kg/cm2.

     Figure  19  shows the consolidation characteristics  (discussed in Sec-
 tion III)  for  the  sludge  used in  the  experimental  landfill.   Using  the settle-
ment equation

                                  C  H.    /      P1 + AP\
                                  C t  I        O      \
                          pri   1 + e  V-^lO   P1    /
                                     o \         o   /

defined previously in Section III, the primary settlement for each layer can
be calculated as follows:

    a.  Lower layer properties.


                                      28

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                              Cc = 1.65



                              H  = 10 ft
                               TJ


                              e  = U.85  at  P'
                               oo


                              P' =138 rb/ft2
                               o


                         APn     = 1190 lb/ft2
                           lower



                    - (1.65)(10 ft)  /.     1328 lb/ft 2
                             .             138




                    = 2.82 ft x 0.9833



                    = 2.77 ft = 33.28 In.



    c.  Upper layer properties.



                              C  = 1.65
                               c


                              H  = 10 ft
                               "C


                              e  = U.85  at  P'
                               o              o


                              P' =138 lb/ft2
                               o


                         AP      = 390 lb/ft2
                           upper



    ,   AW         _ (1.65)(10 ft) /      528 Ib/ft2\
    a.  AH         - — - - i — Q-: - lloe_ _ - — I
          pri          1 + U.85    \   10 n_p -.,,,,.21
          *  upper                  \      138 lb/ft /



                   = 2.82 ft x 0.582



                   = 1.6U ft = 19-T2 in.



    Secondary settlement, defined previously in Section III as
                                        /       q pf*

                          AH    = C H,
                            sec    at  r^b!0 t   . /
                                        \      pri/



can be calculated as follows:



    a.  Lower layer  Ca = 0.018 from Figure 19 laboratory tests corresponding

        to  P'     = 0.66U ton/ft2.
             lower


    b.  Ht = 10 ft.



    c.  For one cycle of log time
                                      29

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                       AH         = C H.
                         sec.,        a t
                            lower



                                  = 0.018 x 10 ft = 0.18 ft



                                  = 2.16 in.



    d.  Upper layer  Ca = 0.0l6 from Figure 19 laboratory tests corresponding

        to  Pepper = 0.26*4 ton/ft2.



    e.  Ht = 10 ft.



    f.  For one cycle of log time




                       AH         = C H,
                         sec         a t
                            upper



                                  = 0.016 x 10 ft = 0.16 ft



                                  = 1.92 in.




    Total settlement (Section III) for the landfill is calculated as follows:



    a.  Lower layer  AH, _, n       = AH  .  + AH    = 33.28 in. + 2.l6 in.
                       total-.         pri     sec
                            lower

                                  = 35.^ in.



    b.  Upper layer  AH           = 19.72 in. + 1.92 in. = 21.6U in.
                       "C O~C £L_L
                            upper



    c.  Total for the landfill



                   AH      = AH.. _       + AH,
                     total     total,         total
                                    lower          upper



                           = 35. W in. + 21.6*1 in. = 57.08 in. = ^.76 ft



The rate of settlement is calculated as previously defined in Section III.



    For the field experimental landfill, settlement rates are calculated as

follows:



    a.  Lower layer  GV = 0.013 in.2/min =0.13 ft2/day  from Figure 19 labo-

        ratory tests corresponding to average load between  0  and  piower  »

        which was 0.332 ton/ft .



    b.  For use of Figure Ik (Section III).  Construction period from begin-

        ning to end was 62 days; therefore, take  to = 62 days.   This time

        includes the construction of the lower layer in addition to construc-

        tion of the load  APn     .  Use of  t  =62 days  and starting the
                            lower             o
                                      30

-------
    settlement-time plot (presented later on page 60) at  time  0  fit  the
    final portion of the field measured behavior data curve fairly good.
    The procedure above assumes that consolidation of the lower sludge
    layer actually begins during its construction, and fit of the pre-
    dicted and field data tends to make the assumption good for times
    after about Uo percent of total consolidation.

c.  H = 5 ft.
d
 '
T  =
 °
          vt° = (0.13 ft2/day)(62 days) = Q

          H2            25 ft2
e.  From Figure
                          U ,
                        percent

                            0
                           10
                           20


                           60
                           80
                           90
                          100
                                           T
                                         0
                                         O.OlU
                                         0.060
                                         0.260
                                         O.i+00
                                         0.660
                                         0.950
                                         2.000
f.  Time for primary consolidation in the field is calculated as  follows:

    (l)  H - 5 ft
        Cv - 0.13 ft2/day
                    TH
                      2
         pri
            n
            lower
                     v
2
rp
— 1
0.

T
0
O.Olll
0.060
0.260
oAoo
0.660
0.950
2.000
'5 ft2
lower .__ ., 0
13 ft /day
t (days)
pri.
lower
0
2.69
11.5^
50.00
76.92
126.92
182.69
38U.62
                                                  . 3 days
g.  Percent consolidation in the field is calculated as follows:
               Percent AH
                                .
                             pri
                             ^
                                      = U x AH
                            lower
                                                 lower
                                  31

-------
            U ,           AH percent AH  .        ,  in.
                ,           \          pri      /
          percent          \	   lower/	

              0                       0
             10                       3.328
             20                       6.656
             UO                      13-312
             60                     19.'
             80                     26.628
             90                     29.952
            100                     33.280
h.  Plot time,  t^^.       ,  versus settlement,  [AH percent AH^^.      J  as
                 -p-L^-l                                          T".-n -1

    in Figure 20.
                  pri                            V              Prin
                    lower                      \                lower/
 i.   Upper layer  Cv =  0.016  in.2/min =  O.l6  ft2/day  from Figure 19 labo-
     ratory tests  corresponding  to  average  load  between  0  and  P'      ,
     which was  0.132 ton/ft2.                                      upper

 j.   t0 = 30 days   for  upper  layer  construction  and surcharge.   H =  5 ft .

 k.   For Figure lU.


                     T   _  Cvto = (0.16 ft2/day)(30  days)

                     ° "  ft2  "         25 ft2

                        =  0.192  ** 0.2

 1.   From Figure ]_h .
u ,
percent
0
10
20
ho
60
80
90
100

T
0
O.OlU
0.060
0.220
0.3^0
0.620
0.900
2.000
m.  Time for primary consolidation in the field is calculated as follows:

    (1)  H - 5 ft
        Cv = 0.16 ft2/day

                      2             2
    (2) t         = ^- = T 	^-^|	 = T x 156.25 days
            upper    v      O.l6 ft /day

                                  32

-------
                  T
                0
                o.oiU
                0.060
                0.220
                0.3^0
                0.620
                0.900
                2.000
                            pri
                                     > days,
 upper
   0
   2.19
   9.38
  3^.38

  53.13
  96.88
 1^0.63
 312.50
    n.  Percent consolidation in the field is calculated as follows
                       Percent AH
                                 pri
= U
                                    upper
                  AH
                    pri
                       upper
                  U ,
                percent
                    0
                   10
                   20
                   UO

                   60
                   80
                   90
                  100
AH percent AH          ,  in.
  \          pri     /
  \ __   upper/
            0
            1.972
            7.
           11.832
           15.776
           17-7^8
           19.720
    o.  Plot time,  t  .       , versus settlement,  AH percent AH        I   as
                     pri      '                       \*         pri     /
                        upper                         \             upper/
        in Figure 21.  Time  t  .        starts at the upper layer construction
                                 upper
        start time, 32-day point in Figure 21.

    p.  The secondary consolidation amounts and times (10 x tprj_) for the
        lower and upper layers can be added to Figures 20 and 21.
    The theory of consolidation assumes settlement starts as the load  AP  is
added to each sludge layer.  Therefore, the settlement prediction curves
should have started at 32 days in Figure 20 and at 62 days in Figure 21.  How-
ever, assuming, as in the previous steps, that settlement started with each
layer's construction gave a better fit of the predicted and measured time
rates.  Had the  AH+ + -.   for each layer been used instead of  AHprj_ , the
settlement-time curves would have been closer to the measured data.
SLOPE STABILITY

    A slope was cut in the consolidated sludge material in order to investi-
gate the applicability of stability analysis.   Failure occurred in the slope,
                                      33

-------
and the composite slip surface analysis  was  found to  be  the  most  applicable.
Prior to cutting the slope,  vane shear tests (Appendix B,  Vane  Shear  Test)
were conducted, and results  are shown in Figure  22 for both  undisturbed and
remolded conditions.

    Figure 23 shows a cross  section for  the  cut  slope and  the approximate  zone
of failure.  Material moved  out of  the slope about 5  to  6  ft back from the  top
of the original cut.  However,  surface tension cracks occurred  as far back  as
16 ft from the top of the original  cut.   The tension  cracks  indicate  material
movement and slumping.   The  sludge  wet unit  weights  (Appendix B,  Unit Weights)
shown in Figure 23 are averages determined from  undisturbed  material  samples.
The process of consolidation increased the unit  weights.

    Figure 2h is a cross section of the  top  sludge layer.  Shown  in the figure
is a trial failure surface,  1,  and  five  slices for computing the  stability  as
previously described in Section III.  Stability  is analyzed  as  follows:

    a.  Fill in a table of necessary values  (discussed in  Section III).
Values from the Cross Section
Slice
Wo. tan a
1 1

2 1
3 1
U 1
5 1
.73

.00
.00
.00
.00
AX
ft
2

3
2
1
1
.1+

.8
.5
.0
.0
P
psf
260

635.2
658.0
5^0.1
279-5
su
psf


768.1
983.2
1339-6
1339-6
deg
30

0
0
0
0
Computed Values
B
o
1079-5

21+13.8
161+5.0
51+0.1
279-5
A'
o
360.3 o

2918.8
21+58.0
1339-6
1339.6
N A
a o
^r- . 0.25 360.
' ''^ V
0.25 +
i.o 2918.
i.o 21+58.
1.0 1339.
1.0 1339.

3
0 25
~F
8
0
6
6
        (l)  The average  vertical total  stress  P  acting on the base of each
            slice  is:

            Pslice 1  = 13°  pcf  x 2  ft = 26° psf

            Pslice 2  = (13° X 3) +  (1°° X 1} + (T2'6  X 2) = 635'2 psf

            Pslice 3  = (13° X 1>5)  +  (1°° X 1} +  (T2'6 X 5) =  658'° psf
            P  -, .    i  = (100 x 0.5)  +  (72.6 x 6.75) =  5ll0.1 psf
            slice 1+                                       ^
            p         =72 6x77x05= 27Q 5 nsf
            slice 5                            ^

        (2)  Average undrained sludge  shear strength at the base of each slice
            is:
                    S  = S       (Appendix B, Vane Shear Test) x y
                           vane

-------
        From Figure l6,  y = 0.6 .   From Figure 22,  obtain average  S
                                                                      vane
        for each slice with a sludge base.   Vane shear tests conducted
        after the slope was cut gave undisturbed values closer  to the re-
        molded ones shown in Figure 22.   Therefore,   S
                                                   vane
                                                         values should
    probably be the remolded ones.   Unloading from cutting the slope
    apparently reduced the shear strengths.   (Sy  remolded values  were
    used in the table above.)

(3) Calculate for each slice
                          B  = P x tan ct x AX
                           o
    Calculate for each slice
                          For sludge  A'  = S  x AX
                  For sand and surcharge  A'  = P x tan
                                                       AX
 ,5) N  =1.0  for the sludge bases.   For the surcharge  base
                                     2
                    ,T       2     cos  a tan a tan
                    N  = cos  a +	
                     a                    F
                       - 0.25
(6) Calculate  A  = A'/N
                o    o  a
b.  Calculate the factor of safety,   F
    approximations or direct solution.
                                               ,  by either  successive
                       = 8056.0
                       = 595T-9
                          8056.0 +

                                       360.3
                                   5957.9
By direct solution:
                  = 8056.0           360.3
                    5957-9
                              35

-------
                          F = 1.352  +
                                        1U89.5
                          (F - l.352)(lU89.5F +  1^89.5) =  360.3F

                          1H89.5F2 +  1^89.5F - 2013.8 = 0

                          F2 - 0.5939F  - 1.352 = 0

                          F2 - 0.5939F  + 0.0882  = 1.1A02

                          (F - 0.29TO)(F - 0.2970) = 1..UU02

                          (F - 0.29TO)2 = 1.UU02

                          F - 0.2970  =  1.20

                          F = 1.^9

    Another trial failure surface,  2, is shown in Figure 2U.   Stability analy-
sis for  surface 2 is as  follows:

    a.   Fill in ta"ble  as previously described.
             Values from the Cross Section  	Computed Values
       Slice        AX    P      U    <(>     B      A'        1^           A
       Ho.   tan ct  ft   psf   psf   deg     °       ° _ ^ __ °


        1    1.73   2.3  260.0   —   30   103U. 5   3^5.3  0.25 + ~~  --- 3^'
        2    1.00   5.8  TOO. 5  676.0   0   ^062.9  3920.9      1-0         3920.9
        3    1.00   2.5  795-9  921.9   0   1989.8  2301+.8      1.0         230^.8
             0.33   1.0  665.3    -   30    219.6   38U.1   0.9 +
        5    0.33   1.0  3U7.7    —   30    lilt. 7   200.7   0.
        6    0.33   1.0   ItO.O    —   30     13.2    23.1   0.9 +
    b.
                           0.25 + ^~^     0.9

        V^B  =  7U3U.68
        £- o


                                         36

-------
    c.  Factor of safety,  F
        F =
          = 0 8374 +        3l*5-3        +       60T.9
                      1858.67 + i^Ml     6691.21 +
                                   r                    r

          = 1.006

Obviously, a less-abrupt slope angle is required for stability.  Another slope
angle was cut at 53 deg in the field test sludge landfill, and no failure
occurred.
                                      37

-------
                                   SECTION V

                                  REFERENCES
 1.  Subcommittee on Sludge Disposal, Committee on Sewerage and Treatment,
     "Advances in Sludge Disposal in the Period October 1, 195^ to Febru-
     ary 1, I960," Journal, Sanitary Engineering Division, American Society of
     Civil Engineers, Vol 88, No.  SA2, Mar 1962.
 2.  Dick, R. I., "Attitudes in Sludge Treatment  and Disposal," Journal,
     Environmental Engineering Division, American Society of Civil Engineers,
     Vol 100, No. EE5, Oct 197^.
 3.  Miner, R. , Unpublished data,  Oct 1971*, National Council of the Paper
     Industry for Air and Stream Improvement, New York, N. Y.
 IK  McKeown, J. J. and Caron, A.  L., "Sludge Dewatering and Handling Prac-
     tices in the U. S. Paper Industry," Special report presented at Tech-
     nology Transfer Seminar on Water Pollution Abatement Technology in the
     Pulp and Paper Industry, May 1975, National Council of the Paper Industry
     for Air and Stream Improvement, New York, N. Y.

 5.  Gillespie, W. J., "Current Practices in Land Disposal of Sludge," Special
     Report (unpublished), Feb 1970, National Council of the Paper Industry
     for Air and Stream Improvement, New York, N. Y.

 6.  "Shear Strength and Permeability of High Ash Pulp and Papermill Sludges,"
     Technical Bulletin No. 252, Dec 1971, National Council of the Paper  In-
     dustry for Air and Stream Improvement, New York, N. Y.

 7.  "Consolidation Behavior of High Ash Pulp and Papermill Sludges," Tech-
     nical Bulletin No. 257, Jun 1972, National Council of the Paper Industry
     for Air and Stream Improvement, New York, N. Y.

 8.  Andersland, 0. B.  et al., "An Experimental High Ash Papermill Sludge
     Landfill:  Second Annual Report," Report No. EPA-670/2-7U-076b, Dec  197^,
     U. S.  Environmental Protection Agency, Cincinnati, Ohio.

 9.  Andersland, 0. B., Vallee, R. P-, and Armstrong, T. A., "An Experimental
     High Ash Papermill Sludge Landfill:  First Annual Report," Report
     No. EPA-670/2-7^-076a, Dec 197^, U. S. Environmental Protection Agency,
     Cincinnati, Ohio.

10.  Standard Methods for the Examination of Water and Wastewater, 13th ed.,
     American Public Health Association, American Water Works Association,
     Water Pollution Control Federation, Washington, D. C., 1971-
11.  Gehm,  H.  W., "Current Developments in the Dewatering of Papermill
     Sludges," Technical Bulletin No. 113, Mar 1959, National Council of  the
     Paper Industry for Air and Stream Improvement, New York,  N.  Y.


                                      38

-------
12.  Zettlemoyer, A. C., Micale, F. J., and Dole, L.  R.,  "Surface Properties
     of Hydrogels Resulting from Treatment of Pulp and Papermill Effluents,
     Part II," Technical Bulletin No. 225, Dec 1968,  National Council of the
     Paper Industry for Air and Stream Improvement, New York, N.  Y.

13.  MacDonald, R. G., ed., Pulp and Paper Manufacture,  Vol.  Ill:   Papermaking
     and Paperboard Making, 2d ed., McGraw-Hill, New York,  1970.

lU.  "The Relationship Between the Constitution and Dewatering Properties of
     Hydrous Sludges," Technical Bulletin No. 260, Oct 1972,  National Council
     of the Paper Industry for Air and Stream Improvement,  New York,  N.  Y.

15.  Mazzola, C. A., Unpublished data, Oct 1969, National Council of  the Paper
     Industry for Air and Stream Improvement, New York,  N.  Y.

16.  Gale, R. S., "Filtration Theory with Special Reference to Sewage
     Sludges," Journal, Institute of Water Pollution Control, No.  6,  1967.

17.  "Mechanical Pressing of Primary Dewatered Papermill Sludges," Technical
     Bulletin No. Ijk, 197^, National Council of the Paper  Industry for  Air
     and Stream Improvement, New York, N. Y.

18.  Fungaroli, A. A., "Pollution of Subsurface Water by Sanitary Landfills,"
     Vol 1 (Drexel Institute of Technology Solid Waste Management Research
     Grant 000162), 1971, U. S. Environmental Protection Agency,  Cincin-
     nati, Ohio.

19-  Emrich, G. H. , "Guidelines for Sanitary Landfills -  Groundwater  and
     Percolation," Proceedings, Environmental Foundation Conference on the
     Application of Environmental Research and Development  on Landfill Dis-
     posal of Solid Wastes, 2^-28 Aug 1970, Deerfield, Mass.

20.  Salvato, J. A., Wilkie, W. G., and Mead, B. E.,  "Sanitary Landfill  -
     Leaching Prevention and Control," Journal, Water Pollution Control
     Federation, Vol U3, No. 10, 208^, 1971.
21.  "Report on the Investigation of Leaching of a Sanitary Landfill," Pub-
     lication No. 10, 195^, California State Water Pollution Control  Board,
     Sacramento, Calif.
22.  "In-Situ Investigation of Movements of Gases Produced  from Decomposing
     Refuse," Publication No. 3k, 1967, California State Water Quality Control
     Board, Sacramento, Calif.
23.  Springer, A. M. , Investigation of Environmental Factors Which Affect the
     Anaerobic Decomposition of Fibrous Sludge Beds on Stream Bottoms, Ph. D.
     Dissertation, Jun 1972, Institute of Paper Chemistry,  Appleton,  Wis.

2k.  Imshenetsky, A. A., The Ecology of Soil Bacteria, University of  Toronto
     Press, Canada, 1968.
25.  MacFarlane, I. C., ed., Muskeg Engineering Handbook, University  of
     Toronto Press, Canada, 1969-
26.  Lambe, T. W., Soil Mechanics, Wiley, New York, 1969.

27.  Terzaghi, K. and Peck, R. B., Soil Mechanics in Engineering Practice,
     2d ed., Wiley, New York, 1967.

28.  Wu, T. H., Soil Mechanics, Allyn and Bacon, Boston,  1966.


                                      39

-------
29.  Calhoun, C. C., "Development of Design Criteria and Acceptance Specifica-
     tions for Plastic Filter Cloths," Technical Report S-72-7, Jun 1972,
     U. S. Army Engineer Waterways Experiment Station, CE, Vicksburg, Miss.

30.  Andersland, 0. B. and Vallee, R. P., "Planning Report on Field Behavior
     of an Experimental Pulp and Papermill Sludge Landfill," Sep 1970, Na-
     tional Council of the Paper Industry for Air and Stream Improvement, New
     York, N. Y.
31.  Andersland, 0. B. and Charlie, W. A., "A Cut Slope in Consolidated Paper-
     mill Sludge," paper prepared for American Society of Civil Engineers 1975
     Geotechnical Engineering Specialty Conference, Raleigh, N. C.

32.  Bjerrum, L., "Embankments on Soft Ground," Proceedings, Specialty Confer-
     ence on Performance of Earth and Earth-Supported Structures, American
     Society of Civil Engineers, 11-1^ Jun 1972, II, 1-5U.

33-  Gillespie, W. J., Gellman, I., and Janes, R.  L. , "Utilization of High Ash
     Papermill Wastes Solids," Proceedings,  Second Mineral Waste Utilization
     Symposium, Illinois Institute of Technology Research Institute, Chicago,
     111., Mar 1970.

3U.  Lambe, R. W., Soil Testing for Engineers, Wiley, New York, 1951.

35.  Achinger, W.  C. and Glar, J. J., "Testing Manual for Solid Waste Incin-
     erators," Open Fill Report SW-3TS, 1973, U. S. Environmental Protection
     Agency, Washington, D.  C.

36.  Office, Chief of Engineers, Department  of the Army,  "Laboratory Soils
     Testing," Engineer Manual EM 1110-2-1906, Nov 1970,  Washington, D.  C.

37.  Mitchell, J.  E., "Evaluation of Soil Mechanics Laboratory Equipment;
     Evaluation of Available Liquid Limit Devices," Miscellaneous Paper
     No. 3-H78, Report 3, Apr 1961, U. S. Army Engineer Waterways Experiment
     Station, CE,  Vicksburg, Miss.

38.  Casagrande, A., "Notes  on the Design of the Liquid Limit Device,"
     Geotechnique, Vol 8, No. 2, Jun 1958, pp 8^-91.

39-  Casagrande, A., Hirschfield, R.  C.,  and Poulos, S. J.,  "Third Progress
     Report on Investigation of Stress-Deformation and Strength Characteris-
     tics of Compacted Clays," Soil Mechanics Series No.  70, Nov 1963, Harvard
     University, Cambridge,  Mass.

Uo.  "Mercury," Data Sheet 203, National  Safety Council,  Chicago, 111.

kl.  "Design Manual - Soil Mechanics, Foundations, and Earth Structures,"
     NAVFAC DM-7,  Mar 1971,  Naval Facilities Engineering  Command, Department
     of the Navy,  San Bruno, Calif.

-------
ZIO
                                                                                          60  -
                                             DAY
                      Figure 1.  Variability of  sludge properties.

-------
LU
o
cr
z
o
o
O


Q
UJ
cc
UJ
Q  10
                                         0  VACUUM FILTER

                                         D  CENTRIFUGE
                       20        30       40        50

                       SLUDGE ASH CONTENT ,  PERCENT
    Figure 2.  Relationship  of sludge dewaterability to  ash content.

-------
  100
   90
   80
   70





Z  60
IxJ
I-
Z
O

0  50


Q

_l
O  40





   30





   20
             0     20     30    40     50     60    70     80

                           ASH CONTENT  ,  PERCENT


              Figure 3-  Solids content versus ash content.
90    100

-------
   60
   50
CO
Q
O  40
a:
a

z
O  30
CD
   20
    10
                BOD
  LEGEND


MUNICIPAL REFUSE

HIGH ASH  SLUDGE
                                ALKALINITY
                                          I
                                                     CHLORIDE
              Figure  U.   Mass  of leachate constituents.

-------
                 MIN OF 8 FT OR AS NEEDED FOR
                 CONSTRUCT/ON EQUIPMENT.
                                                                  -LIMIT SURCHARGE TO
                                                                   APPROXIMATELY HERE
EXTEND TO
DISCHARGE
FACE
                             PEA GRAVEL POCKET
                                                                                           EARTH SURCHARGE
  \-UPPER DRAINAGE BLANKET

UPPER SLUDGE LAYER

       ^-MIDDLE DRAINAGE BLANKET
                                                                                   LOWER SLUDGE LAYER
                      •DRAIN PIPE

                      	AS CONSTRUCTED-
        -BOTTOM DRAINAGE BLANKET
                                  Figure  5-   Dike  and sludge cross  section.

-------
6
(3)
5
(2)


3
(3)
^

5
(2)
6
(3)
7
(1)
3
(3)
"N

1
(4)

J
3
(3)
7
(1)
6
(3)
4
(1)
A

2
(2)
r
j
4
(1)
6
(3)
7
(1)
3
(3)
A

i
(4)

V
3
(3)
7
(1)
6
(3)
4
(0
"N
^
2
(2)
r

4
(1)
6
(3)
7
(1)
3
(3)
^

1
(4)


3
0)
7
(1)
6
(3)
5
(2)

J
3
(3)


5
(2;
6
(3)
3.
              LEGEND

NUMBERS 1,2,3, ETC. REPRESENT
CONSTRUCTION SEQUENCE.
NUMBERS IN PARENTHESES (1), (2), (3),
(4),  REPRESENT THE NUMBER OF EARTH
DIKE SIDES REQUIRED.
"*\- POSSIBLE USE OF MATERIAL IF
DIKES REMOVED.
  Figure 6.   Plan  for  landfill.

-------
                      • SAND BLANKET
EXTEND DIKE AS NEEDED
FOR CONSTRUCTION
       THIRD LIFT
       SECOND LIFT
                                 AS CONSTRUCTED
                                                       THIRD LIFT
                                                       SECOND LIFT
                                                       FIRST LIFT OF DIKE
            - FIRST LIFT OF SLUDGE DUMPED BY TRUCK OR CRANE
                                         LOWER LAYER
NOTE: FIRST, SECOND, AND THIRD LIFTS
      OF SLUDGE PLACED BY TRUCK
      AND CRANE, DUMPING FROM DIKE
                                                         EXTEND DIKE AS NEEDED-
     SECOND LIFT


     FIRST LIFT OF SLUDGE (UPPER LAYER)
                                                                                  DRAIN PIPES
                                      b. UPPER LAYER


               Figure 1.   Sludge landfill construction  steps.
                                          1*7

-------
                                    Wet  density
                                                              W
    WEIGHT
                    VOLUME
                                     (wet unit  weight)    y  =  ~





i
c
i


>:




i
i


5
1 1
[
D



5



\n

\

AIR
^
— — -


WATER

//////
//////
/SOLIDS/
//^//
\ '
crt
1 1

1 '
^>

i
>•
\ ,




1
Dry density Wg
(dry unit weight) y^' = ~ or
Y
. m
Yd ~ 1 + w

^

1

Ul
] '
Unit weight W _
W x" \ / J
of water Y - ^ - 62.U Ib/ft
w v
w


Submerged or buoyed unit weight
(effective weight of sludge
mass below water table) Y' = ~ - Y or y - 62. \


v w m
W
w
Water content w = rr-



W
s
W
Specific gravity G = TT-^ —
s V y


s w
W
Volume of solids


,r _ S

s G y
s w
Volume of voids V = V - V
Void ratio
                                    e  =
     V
      t
     V
Porosity
n  =
V
 v
V
Degree of saturation
                                                  w G
                                        V
                    .    _
                    '  S -
                                                                 w
                                                                   1
                                                                   G
                 Figure 8.  Weight and volume relationships,
                                     1*8

-------
WEIGHT
VOLUME
          WATER
        y SOLID'
                                              AH
WEIGHT
                                                     
-------
o
                1 FT SAND, 100 PCF
                                                    TOTAL VERTICAL
                                                        STRESS
HYDROSTATIC
 PRESSURE
EFFECTIVE STRESS
   IN SLUDGE
                                                                                                     ;oo
                                                                                                     PSF
                           P0 = Po
                                             Figure 10.  Load-depth diagram.

-------
LOAD INCREMENT, AP
    inn  ni
1 FT SAND, 100 PCF u
O ~
\J


1-
^
N
X
t-
0.
U
Q
1 ^
1 U '
1
y y s y y j '

10 FT SLUDGE ,
y 70 PCF / ^ f
y y y y
- / y y '
y , ,
i j
/ ^
y1 x^ '^
i

-/





* s
y
y ^^ /
i

i
1 FT SAND, 100 PCF

700

AP
PSF


138
PSF





776





AP






A






p
P5F

Figure 11.  Load increment added to a sludge layer.
                 51

-------
ro
            I-
            Z
            LJ
         £ °
         O £T
            LU
         LJ Q_
         LU
         LU
           z
           o
           o
20
               40
               60
80
               00
                0.00!
                                            CONSOLIDATION WITH VERTICAL DRAINAGE
                                                   INSTANTANEOUS LOADING
                             NOTATIONS
                             IMPERVIOUS
              ONE-WAY  TWO-WAY
              DRAINAGE  DRAINAGE
                     0.01                0.1

                                  TIME FACTOR  T

             Figure 12.  Time factors  for consolidation analysis,
10

-------
 AVERAGE EXCESS PORE WATER
 PRESSURE RATIO,-U-, PERCENT
                            AVERAGE DEGREE OF CONSOLIDATION
                                       U, PERCENT
                                                                         ELAPSED TIME SUBSEQUENT TO
                                                                         LOADING YEARS, MONTHS, DAYS
                           90  T 10
1.00
0.90
0.80

0.70

0.60

0.50  -


0.40  -


0.30  -
0.20 -
0.10
0.09
0.08

0.07

0.06

0.05


0.04 -


0.03 :
0.02 -
 0.01 -I
                            80  - . 20
            COEFFICIENT OF
            CONSOLIDATION  70
       Cw       FT2/DAY
                        - - 30
0
                                                                SUPPORT LINE
                                 THICKNESS OF COMPRESSIBLE STRATUM,
                                      FEET, ONE-WAY DRAINAGE
                      50 - - 50
                      40 - - 60



                      30 - - 70



                      20 - j- 80



                      1 0 - L 90


                       5 I 95
                                                   100
                                             10
                                                   5

                                                   4

                                                   3


                                                -1- 2
                               10
                                9
                                8

                                7 •

                                6-

                                5
                                                                                                          100 - i
                                                                                                     50-
                                                                                                      (T
                                                                                                      <
                                                                                                      U
                                                                                                               - 1000
                                                                         I.
                                                                   2.
TO DETERMINE THE AVERAGE DEGREE OF
CONSOLIDATION AT A GIVEN TIME AFTER
INSTANTANEOUS LOADING-
   PASS A STRAIGHT LINE BETWEEN THE
   COEFFICIENT OF CONSOLIDATION Cv
   (POINT 1) AND THE THICKNESS OF
   COMPRESSI BLE STRATUM HAVING ON E-
   WAY DRAINAGE (POINT 2) TO ESTAB-
   LISH POINT3ON THE SUP PORT LINE.
   FROM THE GIVEN ELAPSED TIME
   AFTER LOADING (POINT 41 PASS A
   STRAIGHT LINE THROUGH POINT  3 TO
   OBTAIN POINT 5. THE DESIRED VALUE
   OF THE AVERAGE DEGREE OF CON-
   SOLIDATION (OR AVERAGE EXCESS
   PORE WATER PRESSURE RATIO) IN
   PERCENT.
   PROCEED IN A SIMILAR MANNER USING
   KNOWN DATA TO ESTABLISH UNKNOWN
   VALUES, REVISING SEQUENCE OF
   OPERATIONS AS REQUIRED.

   NOTES:

   NOMOGRAPH APPLIES TO ONE-WAY
   DRAINAGE OF A STRATUM.
   IF COMPRESSIBLE STRATUM HAS TWO.
   WAY DRAINAGE USE ONE-HALF OF
   STRATUM THICKNESS.
   NOMOGRAPH APPLIES TO CASES OF
   DOUBLE DRAINAGE WHERE INITIAL
   DISTRIBUTION OF EXCESS PORE
   WATER PRESSURE IS LINEAR WITH
   DEPTH, OR FOR CASES OF SINGLE
   DRAINAGE WHERE EXCESS PORE
   WATER PRESSURE IS CONSTANT WITH
   DEPTH.
                                                                                                      5 - -
if!
X
\-
z
o
                                                                                                          3500

                                                                                                          3000

                                                                                                          2500

                                                                                                          2000
                                                                                                         ©
                                                                                                          500


                                                                                                        - 4OO
                                                                                                       - - 300
                                                                                                         '- 200
                                                                                                               <
                                                                                                               D
                                                                                                         - 100
                                                                                                                50


                                                                                                                40


                                                                                                               L 30




                                                                                                               - 20
                     Figure 13.   Nomograph for  consolidation with vertical drainage.

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                                                                I  I  I  I II
                                                   CONSOLIDATION  WITH VERTICAL DRAINAGE
                                                       GRADUAL CONSTRUCTION  LOADING
                                                              NOTATIONS:
  CONSOLIDATION
  DURING CONSTRUCTION
  AS PCT COMPLETE
  UNDER PORTION OF
  LOAD IN PLACE AT
  ANY TIME 	*
    END OF
CONSTRUCTION
                                                                    BEFORE
                                                                    TIME
                                              0.!

                                       TIME  FACTOR T

Figure lU.  Time factors for consolidation  analysis with gradual load  application.

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                                TRIAL ?
5   3
                                           I   /   1     /    s^TRIAL 4
                                           7	7	7	T	7
                                                                     SURCHARGE
                                                  "/  .Aa
                     5AND


                                                                      UPPER
                                                                     SLUDGE
                                                                      LAYER
                                                                       >M
                                                                     SAND >'.,
                                                                      LOWER
                                                                      SLUDGE
                                                                      LAYER
7 FT i!
                                                                     SAND LAYER
                             Figure 15-  Slope analysis.

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   1.2
   1.0
   0.8
   0.6
  0.4
              20     40    60     80     100    120

                           PI °70
                                  VANE

Figure l6.   Correction factor for converting vane shear
       strengths to field shear strengths  (22).

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                                 +   INSTRUMENT GROUPS




                               	EARTH SURCHARGE LIMIT




                               	BOTTOM SAND BLANKET LIMIT



                                 •   ELEVATIONS
Figure  17.   Experimental landfill, plan view.
                      57

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v/i
CD
                                                                            INSTRUMENT GROUP

                                                                       EARTH SURCHARGE-
                              INSTRUMENT GROUP 5~
                              14' OR 20'
                           EARTH DIKE
                                                               UPPER SLUDGE LAYER
                                                                (INITIALLY 10' THICK)
                                     70' WIDE GRAVEL DRAIN
                                     (NORTH SIDE ONLY)
                                                                       LOWER SLUDGE LAYER
                                                                       (INITIALLY 9.5' THICK)
                                                                                                  i
                                                                                                                • PIPE
                                                     4-

                                                     +
                                    -4' WELLPOINT
                        -8"0 DRAIN PIPE (NORTH SIDE ONLY)
    LEGEND

SETTLEMENT PLATES

PIEZOMETERS
                                                                 £:Q--&;X£ SAND DRAINAGE BLANKETS
                                                                       ' •> GRAVEL
                                 Figure 18.   Typical cross section  of experimental landfill.

-------
o
I-
cc
Q
O
>
      5.0
      4.5
      4.0
      3.5
      3.0
      2.5
      2.0
                                PO =138 PSF =0.069 T/FT2
                                en = 4.85
                                Cc = 1.65
        0.05
                  O.I
                           0.2
                                    0.4   0.6
    0.015
                           0.2       0.4   0.6      I
                                          ,    ^
                           PRESSURE P, T/FT2

Figure 19.  Consolidation  characteristics of sample
                                                          2    3
                                                         sludge.

-------
O
                                                                     LEGEND

                                                                    SOIL SURCHARGE

                                                                    SAND BLANKET

                                                                    SLUDGE

                                                                    SETTLEMENT PLATE
                                                                              180
                                          FIELD SETTLEMENT OF LOWER SLUDGE LAYER
                                                                                        210
                                                                                                 240
                   40
                     Figure 20.
Comparison of predicted and measured time-settlement  curves,
               lower  sludge layer.

-------
   30
LU
1/1
<
m

LL|

o  20
m
UJ
IS
O
D
_J
co

u.  10
2
O
I-


UJ
_l
UJ
   10
I-
z
Id
2
UJ
_J


[H
CO
   20
   30 '—
                                                               SOIL SURCHARGE

                                                               SAND BLANKET

                                                               SLUDGE

                                                               SETTLEMENT PLATE
                                                      TIME, DAYS
                                                          THEORY, r =0.0?6 IN. /MIN
                        FIELD SETTLEMENT OF UPPER SLUDGE LAYER
      Figure 21.  Comparison  of actual  and predicted time-settlement  curves, upper sludge  layer.

-------
     1.90 T/M
  SAND
SLUDGE
  SAND
SLUDGE
  SAND
    SEPT  7, 1972
                        94
                        90
                      u
                      LJ
                        82
                        78
                             REMOLDED
                                             UNDISTURBED
0     4      8     12     16     20

  VANE SHEAR STRENGTH,  T/M2
NOTE: 204.857 x T/M2 = p/FT2

   Figure  22.  Experimental  landfill vane shear strength
            immediately  before slope excavation.
                             62

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                                          11 FT
          1.2
                                                              100 PCF
                           APPROXIMATE
                           FAILURE ZONE
                                                2 FT
                                               I FT '
                                               7.2 FT
  SLUDGE
  Y, - 72.6 PCF
SAND X,   100 PCF
      M
 SLUDGE
  >,, - 76.5 PCF
                                                 FT
                                                          SAND
Figure  23-   Cut  slope in experimental  sludge landfill.
                            63

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                                                          6.2 FT
                                                                              2 FT
CTN
f
                                                     /   	TRIAL FAILURE

                                                            SLIP SURFACE 2
                                                                    LOWER SLUDGE LAYER
                       Figure 2U.  Cross section of top sludge layer  for stability analysis.

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   TABLE 1.  PRIMARY SLUDGE PRODUCTION ASSOCIATED
              WITH PAPER MANUFACTURING

      ,.    „         _, ,                  Percentage
      Manufacturing Category            „ ^  n   .
	    	of Production
Unbleached kraft/linerboard                 2
Groundwood/newsprint                        3-U
Bleached kraft/market pulp paper,
  and paperboard                            3-k-
Bleached and unbleached paperboard          3-^
Nonintegrated fine paper                    2-3
Nonintegrated tissue                        2-3
Sulfite pulp and paper                      3-^
Integrated groundwood and printing
  paper or specialty paper                  3-h
Wastepaper board                            0-U
Deinking                                   10-25
        TABLE 2.  "NORMAL" SLUDGE COMPOSITION

    m                Consistency         Ash Content
    Type
	Solids, percent	percent
Board mills              2-10               50-70
Chemical pulp            1-10               20-50
Deink pulp               3-10               25-60
Groundwood               2-5                 1-20
Paper mills              1-5                50-70
                         65

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TABLE 3.   PHYSICAL CHARACTERISTICS OF SLUDGES ORIGINATING
              IN HIGH ASH SLUDGE LANDFILLS
Mill
A
B
C
D
E
F
>100 Mesh
percent
Range
7-31
k-32
9-3k
11-U8
1-57
3-^6
Average
21.7
11.7
17. U
23.1
30.5
16.1
<100 Mesh
percent
Range
67-99
6k-9k
62-90
52-87
^3-70
51-97
Average
19.k
85.5
80.8
75.6
61.2
81.9
Ash Content
percent
Range
Ul-72
k2-5h
5)4-8)4
35-80
66-91
5U-95
Average
55
U8
6k
62
73
75
            TABLE k.   FIBRE CLASSIFICATION FOR
                 SELECTED HIGH ASH SLUDGES
        Mill

         1
         2
         3
         k
    Fraction Retained on
the Indicated Mesh, percent
lU     28
2.k    1.0
3.0    1.7
0.2    0.9
O.k    2.8
            k8
           13.7
            7.1
            3.8
            9-7
100
<100
15.2    67.7
11.2    76.9
 2.3    92.8
 8.9    78.2
                            66

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                    TABLE 5-   ANALYSIS OF LEACHATE QUALITY

Sample
Date sampled
COD (mg/£)
BOD (mg/£)
PH
Specific conductance
(pmho/cm)
Turbidity (MTU)
Color (color units)
Total solids (mg/Jl)
Dissolved solids (mg/£.)
Suspended solids (mg/&)
Total iron (mg/&)
Total hardness (mg/£ as
CaCO )
Chloride (mg/£)
I*
10/19/72
9,580
6,6lH
7.6
6,200
56
352
11,786
11,710
76
2.5
6,810
201
II*
11/21/72
H,ooo
2,660
7-7
3,360
13
130
H,960
MHO
120
1.6
3,230
75
III*
12/12/72
H,l60
2,860
7-7
3,100
9
165
5,130
5,100
30
1.5
3,230
70
IV*
12/29/72
H,700
3,250
7.8
6,010
17
H39
9,730
9,570
160
H.3
6,565
206
Vt
2/10/73
7,585
5,158
7.5
H,015
15
187
8,885
7,651
1,23H
3.6
H,310
111
Alkalinity (mg/K, as
  CaCO )                     8,670     U,130      U,130      8,770       5,810
Sulfate (mg/£)                 <1        <1         <1         <1          <1
Total Kjeldahl nitrogen
  (mg/£)
Total phosphorus (mg/£)
  *Sample extracted from the midsand drainage blanket.
  tSample taken from the bottom slope indicator pipe,  which is accountable for
   the irregular suspended solids concentration.
                                     67

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      TABLE 6.   TRACE ELEMENTS CONTAINED IN PAPER-MILL PRIMARY SLUDGE
Mill
A
B
C
D
E
F
G
H
Elements, Ib/ton
Cu Zn
14.60
* 	
—
0.19 0.70
1.60
0.12
0.10
0.20
Pb Hg
0.0)4
*
—
* 	
0.08 0.09
0.10 0.05
0.20 0.09
0.16 O.lH
Fe Cd
0.80
2.80
H.20
25-50 *
15.20
2.60
13.80 0.02
35.00
Cr
_ —
*
__
0.03
0.08
0.04
o.oU
0.08
Ni
—
—
—
0,03
0.08
0.10
0.02
0.06
Mg
—
*
5.00
0.65
—
—
—
—

*Analysis showed presence of only trace amounts.
            TABLE 7.   LEACHATE ATTENUATION  PROPERTIES  OF  SOILS
Soil
Type

Sand
Organic
loam
Organic
loam
Clay
Organic
loam
Conditions
Hydraulic
Loadins
,, -, / Aerobic Anaerobic
M gal/
acre/day
6.8 x

6.8 x

6.8 — x
6.8 x

27.0 x
Removals, percent
Dis-
COD solved
Solids
93 58

96 77

85 65
9^ 76

85 U6

Turbidity

91

96

68
68

51

Conductivity

57

80

75
79

IfU

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            TABLE
PHYSICAL PROPERTIES OF PAPER-MILL SLUDGE
Sludge Sample
No.
L-0
L-l*
L-2*
U-lt
U-2t
U-3t
U-Ut
U-5t
Elevation
in Layer
ft
5
2.5
7-5
2.5
h
5
7.5
10
Consistency
Limits
325.1+-llil.6
257. 3-102.7
2U7.7-105.6
18U.5- 86.0
218.5-101.6
297-5-133.0
287.^-122.1
302.8-138.6
Ash
Content
percent
35-7
U2.2
U3.3
59-^
U6.5
36.5
3^.2
32.2
Solids
Content
percent
by weight
28.5
27.2
28.2
3^.U
31.9
26.9
29.0
28. h
Specific
Gravity
2.01
2.05
2.07
2.2U
2.07
1.91
1.87
1.92
^Average of three samples.
tAverage of three tests per sample location.

 Sludge unit weight as placed,  y  ^70 pcf.
                                 m
 Soil surcharge unit weight,  y  * 130.U pcf.
                               m
 Laboratory test sample locations.
                     Laboratory test sample locations.
                                • Sand-;-
                    \\   Upper sludge layer
                            : •'.-.•.' Sand •'•.  ;. '• •'.•^J/J-

                            Natural  soil
                                    69

-------
                                                                                                              20
                                                                                                                 Z
                                                                                                                 UJ

                                                                                                                 2.
                                                                                                                 Ul
                                                                                                              40
o
Z
UJ
2
UJ
_J
t-

Ul
                                                                                                              60
                                                                                                                 in

                                                                                                                 >
                                                                                                                 (C
                                                                                                                 ct
                                                                                                                 0.
                                                                                                                 Z
                                                                                                                 UJ
                                                                                                                 o
                                                                                                                 cr
                                                                                                              60
                                                                                                              IOO
                                                                                                          I5

                                                                                                          II
                                                      TIME ,  DAYS
                                             Plate  1.   Settlement-time plot.

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                                APPENDIX A
                          METRIC CONVERSION TABLE
     Multiply
inches
feet
miles (U. S. statute)
square feet
acres
gallons  (U. S. liquid)
pounds (mass)
tons (short)
pounds (force) per
  square foot
tons (force) per
  square foot
pounds (mass) per
  cubic foot
degrees  (angle)
Fahrenheit degrees
By
                                                            To Obtain
                               0.025U
                               0.30U8
                               1.6093^
                               0.0929030>4
                               0.003785^12
                               0.145359214
                             907.18U7
                              147.88026

                              95.76052

                              16.018^6
                               0.017^5329
                               5/9
                metres
                metres
                kilometres
                square metres
                square metres
                cubic metres
                kilograms
                kilograms

                pascals

                kilopascals

                kilograms per cubic metre
                radians
                Celsius degrees or Kelvins'*
*To obtain Celsius (C) temperature readings from Fahrenheit  (F) readings,
 use the following formula:  C = (5/9)(F - 32).  To obtain Kelvin  (K) read-
 ings, use:  K = (5/9)(F - 32) + 273.15-
                                    71

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                                  APPENDIX B

                   TESTING PROCEDURES FOR SLUDGE PROPERTIES


    Pulp and paper-mill sludges have the physical appearance of clay interr-
woven with cellulose fibers.   Depending on the manufacturing processes in-
volved, sludge color varies from gray to brown and consistency varies from
fluid to plastic.  A soft plastic material results from dewatering the sludge,
Depending on the method used for dewatering, the solid content ranges from
approximately 1 to 65 percent.   The manufacturing and conservation processes
control the solids composition, which generally includes coating and filler
pigments, fibers, and fines.   Clay with small amounts of aluminum hydrate,
titanium oxide, lime, and iron compose the fixed solids.  The remainder of the
sludge is cellulose, starch,  resins, glue, ink, and organic compounds.   High
ash sludges have been defined as those which have a fixed solids content of
60 percent or greater (33).  As a result of these variations in composition,
sludges can show a wide variation in physical properties and behavior.

    As for other materials subjected to engineering purposes and analyses,
knowledge of some of the physical properties of sludges is desired to charac-
terize their behavior.   Knowledge of the physical properties of, experience in,
and behavior of the various sludges will lead to better understanding and pre-
diction of their behavior.  Based on experience with soil material properties,
the following sludge properties are believed to be important:

    a.  Solids and water contents.

    b.  Unit weights.

    c.  Specific gravity of solids.

    d.  Consistency limits.

    e.  Permeability.

    f.  Ash content and organic content.

    g.  Physical description of the fibers.

If good and accurate records  of the above-mentioned properties are kept,
eventual accumulation of the  information should become very valuable in modi-
fying the test procedures in  this manual.

    At least three of each of the following tests should be conducted per
sludge sample to insure consistency and accuracy of results.  Great care


                                      72

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should be exercised in obtaining representative sludge samples and in conduct-
ing the test.s_.  Sludge samples should be taken and tested every time the manu-
facturing processes change and probably weekly or biweekly.   When samples are
taken, they should be stored in airtight containers in a cool place.  Airtight
containers prevent loss of moisture and may be glass or plastic jars that seal,
plastic bags, etc.  Metal containers are not recommended because of corrosion.
A cool storage atmosphere prevents moisture changes or variation within the
sample due to condensation.  A refrigerator will provide cod stoiage.

    Test methods for determining sludge properties are given below.   Refer-
ences 3^4-36 describe these methods.  All methods except those for ash and or-
ganic contents are from Reference 36.  The following tests were conducted on
essentially one sludge material (9) and were found to be applicable.  However,
because of the wide variation in sludge properties, test methods may have to
be modified on a case-by-case basis.  Accumulated records of the various
sludge properties and method modifications will form a basis for changing the
test, methods given below.
SOLIDS AND WATER CONTENTS

Definitions

    Solids content,  s  , is defined as the ratio, expressed as a percentage,
of the weight of solids to the weight of the wet sample.

    Water content,  w  , is defined as the ratio, expressed as a percentage,  of
the weight of water in a sample to the weight of the solids.

Apparatus

    The test apparatus should consist of the following:

    a.  Oven, preferably of the forced-draft type, automatically controlled to
        maintain a uniform temperature of 85 ± 5°C throughout the oven.  (85°C
        is suggested for organic soils in Reference 25.)

    b.  Balances, sensitive to 0.1 g for samples weighing 50 to 500 g and to
        1.0 g for samples weighing over 500 g.

    c.  Specimen containers.  Seamless containers with lids are recommended.
        The containers  should be of a metal resistant to corrosion (aluminum
        is satisfactory) or of glass.  They should be as small and light in
        weight as practicable in relation to the amount of material to be used
        in the determination.  For routine tests, a minimum sample size should
        contain at least 10 g of solids (25).

Procedure

    The test procedure  is as follows:

    a.  Record all identifying information for the specimen,  such as project

-------
        name, sample number, date, manufacturing process, or other pertinent
        data, on a data sheet (Plate B-l is a suggested form).

    "b.  Record the number and tare weight of the specimen container.

    c.  Place the specimen in the container, set the lid securely in position,
        and immediately determine the weight of the container and wet sludge
        by weighing on an appropriate balance.

    d.  Before the specimen is placed in the oven,  remove the lid; depending
        on the type of container, the lid is usually placed under the con-
        tainer in the oven.  Then place the specimen and container in the oven
        heated to 85 +_ 5°C.  Leave the specimen in  the oven until it  has dried
        to a constant weight.  The time required for drying will vary depend-
        ing on the type of sludge, size of specimen, oven type  and capacity,
        and other factors.  The influence of these  factors generally  can be
        established by good judgment and by experience with the sludges being
        tested and the equipment available in the laboratory.   When in doubt,
        reweigh the ovendried specimens at periodic intervals to establish the
        minimum drying time required to attain a constant weight.   Depending
        on specimen size, two or three days may be  required for drying.  Dry
        specimens may absorb moisture from wet  ones; therefore, any dried
        specimens must be removed before wet specimens are placed in  the oven.

    e.  After the specimen has dried to constant weight, remove the container
        from the oven and replace the lid.   Allow the specimen  to cool until
        the container can be handled comfortably with bare hands.   If the
        specimen cannot be weighed immediately after cooling it should be
        placed in a desiccator;  if a sample is  left in the open air for a con-
        siderable length of time it will absorb moisture.

    f.  After the specimen has cooled, determine its dry weight and record it
        on the data sheet.

Computations

    The following quantities are obtained by direct weighing:

    a.  Weight of tare plus wet  sludge,  g

    b.  Weight of tare plus dry  sludge,  g

The water content in percent of  ovendry weight  of the sludge is equal to:


  (weight of tare plus wet sludge) - (weight of tare plus dry sludge)
               (weight of tare plus dry sludge) - (tare)
or
                          w
                     w = — x 100  or  w = 100 x
                         W                        s
                          s

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where   w = water content, percent

       W  = weight of water,  g

       W  = weight of dry solids,  g

        s = percent of dry solids, percent

The solids content in percent of wet weight of the sludge is equal to:

               (weight of tare plus dry sludge) - (tare)
               (weight of tare plus wet sludge) - (tare)

or

                            ¥s   n nn             100
                        s = 7— x 100  or  s =
                                                w
                                               loo + -

where  W = total wet specimen weight,  g

Possible Errors

    Following are possible errors that would cause inaccurate determinations
of solids and water contents:

    a..  Specimen not representative.  The specimen must be representative of
        the sample as required for determination purposes.  For example,  tc
        determine average water content of a sludge, the specimen must be
        large enough to contain representative amounts of all constituents.

    b.  Specimen too small.  As a rule, the larger the specimen, the more ac-
        curate the determination because of the larger weights involved.

    c.  Loss of moisture before weighing wet specimen.  Even in a covered con-
        tainer a specimen can lose a significant amount of water unless
        weighed within a short period.

    d.  Incorrect temperature of oven.  The ovendry weight of many sludges is
        dependent on the temperature of the oven, so variations in temperature
        throughout the interior of an oven can cause large variations in the
        computed solids and water content (3M-

    e.  Specimen removed from oven before obtaining a constant ovendry weight.

    f.  Gain of moisture before weighing ovendry specimen.

    g.  Weighing ovendry specimen while still hot.  The accuracy of a sensi-
        tive balance may be affected by a hot specimen container -

    h.  Incorrect tare weight.  The weights of specimen containers should be
        checked periodically and should be scratched on the containers to
        avoid possible errors in reading such weights from lists.


                                      75

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UNIT WEIGHTS

    Two methods for determining unit weights are presented in the following
paragraphs—displacement and volumetric.   The displacement method should be
used for the plastic-type sludges that can support themselves in uncontained
mounds.  The volumetric method should be  used for the fluid-type sludges.

Definitions

    Wet unit weight,  ym ,  or wet density, is the weight (solids plus water)
per unit of total volume of sludge.   The  wet unit weight is usually expressed
in pounds per cubic foot.

    Dry unit weight,  Yd »  or ^y density, is the weight of ovendried sludge
solids per unit of total volume of sludge, and is usually expressed in pounds
per cubic foot.

Volumetric Method

    The volumetric method is described below.

Apparatus--
    The apparatus should consist of the following:

    a.  A volumetric container of known volume and as large as possible in re-
        lation to the constituents of the sludge being tested.  The container
        should be of materials not susceptible to corrosion such as seamless
        aluminum or glass with lids.

    b.  The same type of oven and balance as those for solids and water con-
        tent determinations.

Procedure—
    The procedure is as follows.

    a.  Record on a data sheet (Plate B-2 is a suggested form) all identifying
        information for the sludge sample.

    b.  Determine and record the volumetric container weight in grams.

    c.  Fill the volumetric container' with the fluid-type sludge and strike
        off the top evenly.  Weigh the container plus wet sludge and record
        the weight.

    d.  Place the sludge and container in the oven and dry it as described for
        the solids and water content determinations.   Obtain and record the
        weight of the container plus dry  sludge.

C omput at i o n s —
    The following quantities are obtained in the test.

    a.  Weight of tare (volumetric container) plus wet sludge.  The tare


                                      76

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        weight is subtracted from this value to obtain the weight  of wet
        sludge,  W .

    b.   Weight of tare plus dry sludge.   The tare weight  is subtracted from
        this value to obtain the weight of dry sludge, ¥s ,  or  an alternate
        procedure is  dry weight of specimen computed by the following equation :

                 TT        wet weight of specimen            W
                 w  — - - ^— - = — --
                  s        water content of specimen   1  + 0 . Olw
                                      100

    c.   The inside volume of the volumetric container. Volume   V   of the wet
        sludge specimen is equal to this volume.

    d.   Wet unit weight,  ym , and dry unit weight,   j^ •>  expressed in terms
        of pounds per cubic foot, are computed by the following  equations:
  = weight in g of wet specimen
m   volume in cc of wet specimen
                                                 x 62 ^ =  W
                                                     '
                                                          V
                                                            x
                                                          W
                  = weight in g of dry specimen  x ^^ =  _§. x  g2.U
                d   volume in cc of wet specimen     '     V


Displacement Method

Apparatus—
    The apparatus should consist of the following:

    a.  Wire basket of sufficient size to contain the sludge specimen.

    b.  Can, or container, of sufficient size to submerge  the wire basket  and
        specimen.

    c.  Specimen container.  The container should be of materials not  suscep-
        tible to corrosion such as seamless aluminum or glass with lids.

    d.  Paintbrush.

    e.  Microcrystalline wax or paraffin.*

    f.  Container for melting wax, preferably with a self-contained  thermostat.


  *Among the many microcrystalline waxes found satisfactory are Product 2300
   of the Mobile Oil Company, Microwax T5 of the Gulf Oil  Corporation,  and
   Wax 1290 of the Sun Oil Company.  Paraffin alone is not as suitable for
   sealing sludge specimens because its brittleness and shrinkage upon cooling
   will cause cracking, especially in thin sections and at corners;  a mixture
   of 50 percent paraffin and 50 percent petrolatum has properties  that ap-
   proach those of a microcrystalline wax (36).


                                      TT

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    g.   Thermometer,  range  0  to  50°C,  graduated  in  0.1  deg.

    h.   The same type of oven and balance  as  those  for  solids  and  water_con-
        tent determinations.

    i.   A hobby tool  with a high-speed rotating  circular  saw (preferably about
        3/^-in.-diameter saw  blade).

Procedure—
    The procedure is  as follows:

    a.   Record on a data sheet (Plate  B-3  is  a suggested  form)  all identifying
        information for the sludge sample.

    b.   Determine, if not previously established, the specific  gravity  of the
        wax to be used.  (About  0.9 g  per  cm2, but  it should be determined for
        each batch of wax.)

    c.   Cut a specimen from the  sample to  be  tested.  (The size of the  speci-
        men is not very important provided the capacity of the  balance  is not
        exceeded.  In general, more accurate  results will be obtained with
        larger specimens.)  Carefully  trim the specimen to a fairly regular
        shape.  The circular  saw hobby tool is recommended for  trimming be-
        cause of the  sludge fibers.  Re-entrant  angles  should be avoided, and
        any cavities  formed by large particles being pulled  out should  be
        patched carefully with material from  the trimmings.

    d.   Determine and record  the wet weight of the  sludge specimen.

    e.   Cover the specimen  with  a thin coat of melted wax, either  with  a
        paintbrush or by dipping the specimen in a  container of melted  wax.
        Apply a second coat of wax after the  first  coat has  hardened.   The wax
        should be sufficiently warm to flow when brushed  on  the sludge  speci-
        men, yet it should  not be so hot that it penetrates  the pores of the
        sludge.  If hot wax comes in contact  with the specimen  it  may cause
        the moisture  to vaporize and form  air bubbles under  the wax.

    f.   Determine and record  the weight of the wax-coated specimen in air.

    g.   Determine and record  the submerged weight of the  wax-coated specimen.
        This is done  by placing  the specimen  in  a wire  basket hooked onto a
        balance and immersing the basket and  specimen in  a can  of  water as
        shown in Figure B-l.   In order to  directly  measure the  submerged
        weight of the wet sludge and wax,  the balance must have been previ-
        ously balanced with the  wire basket completely  submerged in the can of
        water.  Insure that the  specimen is fully submerged, and that the
        basket is not touching the sides or bottom  of the container.  Measure
        the temperature of  the water.

    h.   Remove the wax from the  specimen.  It can be peeled  off after a break
        is made in the wax  surface.  Use the  entire sample,  or  as  much  as is
        free of wax inclusions,  for a  water content determination.


                                      78

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Computations —
    The following quantities are obtained directly in the test:

    a.  Weight of uncoated specimen,  ¥ ,

    b.  Weight of sludge plus wax.  The weight of uncoated specimen,   V ,  is
        subtracted from this value to obtain the weight of wax.

    c,  Weight of sludge plus wax in water.

    The following computations will be made:

    a.  Divide the weight of the wax by its specific gravity.   This gives  the
        volume of the wax.

    b.  Subtract the weight of the wax-coated specimen in water from its
        weight in air-  The difference divided by the density of water at  the
        test temperature (see Table B-l) is numerically equal to the  volume  of
        the coated specimen in cubic centimeters,

    c.  Subtract the volume of wax from the volume of the coated specimen  to
        obtain the total volume of the sludge specimen,  V .

    d.  Compute the water content of the specimen.  If the entire specimen is
        used for the water content determination, obtain the  dry weight of
        specimen,  Ws , directly.  If only a portion of the initial specimen
        is used for the water content determination, compute  the dry weight  of
        specimen according to the following equation:

                w  _   wet weight of uncoated sludge   _     W
                 s    _,  ,  water content of wet sludge     .,     w

                                      100                     100

        Based on the information above, compute the unit weights as  specified
        hereinbefore.

Possible Errors

    Following are possible errors that would cause inaccurate determinations
of the total volume:

Volumetric Method—
    a.  Imprecise measurement of volumetric cylinder.   Three height  measure-
        ments and nine diameter measurements should be made to determine  the
        average height and diameter of the cylinder.   Precise calipers  should
        be used for these measurements rather than flat scales.

    b.  Imprecise weight measurements.

Displacement Method—
    Voids on surface of specimen not filled by wax or  air bubbles  formed  be-
neath wax.
                                      79

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SPECIFIC GRAVITY

Definition

    The specific gravity of solids,   Gs  ,  of a sludge  is  the ratio  of the
weight in air of a given volume of solids  at a stated  temperature to  the
weight in air of an equal volume of  distilled water  at a  stated temperature.

Apparatus

    The apparatus should consist of  the  following:

    a.  Volumetric flask, 500-cm^ capacity or larger.

    b.  Vacuum pump, with piping and tubing for connections  to  each flask (as
        shown in Figure B-2).   The connection to each  flask  should  be provided
        with a trap to catch any water drawn from the  flask.

    c.  Thermometer, range 0 to 50°C, graduated in 0.1 deg.

    d.  Evaporating dish.

    e.  Water bath.

    f.  The same type of oven and balance  as those for solids and water con-
        tent determinations.

Calibration of Volumetric Flask

    The volumetric flask will be calibrated for the  weight of the flask and
water at various temperatures.   The  flask  and water  are calibrated  by direct
weighing at the range of temperatures likely to be encountered  in the labora-
tory.  The calibration procedure is  as follows:

    a.  Fill the flask with deaired-distilled (or deaired-demineralized)  water
        to slightly below the calibration  mark and place  in  a water bath  which
        is at a temperature between  30 and 35°C.  Allow the  flask to  remain in
        the bath until the water in  the  flask reaches  the temperature of  the
        water bath.  This may take several hours.  Remove the flask from  the
        water bath, and adjust the water level in the  flask  so  that the bottom
        of the meniscus is even with the calibration mark on the neck of  the
        flask.  Thoroughly dry the outside of the flask and  remove  any water
        adhering to the inside of the neck above the graduation; then weigh
        the flask and water to the nearest 0.01 g.   Immediately after weighing,
        shake the flask gently and determine the temperature of the water to
        the nearest 0.1°C by immersing a thermometer to the  middepth  of the
        flask.

    b.  Repeat the procedure outlined in step a at approximately the  same
        temperature.  Then make two  more determinations,  one at room  tempera-
        ture and the other at approximately 5 deg less than  room temperature.

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    c.  Draw a calibration curve showing the relation between temperature and
        corresponding weights of the flask plus water.  Prepare a calibration
        curve for each flask used for specific gravity determinations and
        maintain the curves as a permanent record.   A typical calibration
        curve (omitting the fine grid necessary for accurate determinations)
        is shown in Figure B-3.

Preparation of Sample

    Particular care should be taken to obtain representative samples for deter-
mination of specific gravity of solids.  The sample of sludge should be at its
natural water content, because sludges with high organic content would be dif-
ficult to rewet after having been oven-dried.

Procedure

    The procedure for determining the specific gravity of sludges at natural
water content is as follows.

    a.  Record all identifying information for the  sample,  such as project
        name, sample number, and other pertinent data, on a data sheet (see
        Plate B-^4 for suggested form).

    b.  Place a representative sample of sludge equivalent  to approximately
        50 to 80 g (or greater depending on the size of sludge constituents)
        ovendry weight in a dish and, by means of a spatula, mix with suffi-
        cient distilled or demineralized water to form a slurry, if it is not
        already a slurry.  Place the slurry in a volumetric flask and fill the
        flask approximately half full with distilled water.

    c.  Connect the flask to the vacuum line as shown in Figure B-2 and apply
        a vacuum of approximately 29-0 in. of mercury.  Agitate the flask
        gently at intervals during the evacuation process;  commercially
        available mechanical agitators may be used  for this purpose.   The
        length of time that vacuum should be applied will depend on the type
        of sludge being tested.  The process probably will  require 6 to 8 hr;
        some sludges may require less time for removal of air but this should
        be verified by experimentation.  To insure  continuous boiling, the
        temperature of the flask and contents may be elevated somewhat above
        room temperature by immersing in a water bath at approximately 35°C.
        Additionally, entrapped air* should be removed by boiling** the
        suspension gently for at least 30 min while occasionally rolling the
        flask to assist in the removal of air.  The boiling process should be
        observed closely as loss of material may occur.  Allow flask and con-
        tents to cool, preferably overnight, before filling and checking.

   *Air removal from organic sludges usually cannot be accomplished by the ap-
    plication of vacuum.  Therefore, it will be necessary to boil the suspen-
    sion contained in the flask for about 30 min, adding distilled or deminer-
    alized water carefully from time to time to prevent boiling the sample dry.
    The flask should at all times be approximately  half full.
  **Use of indirect heat such as a sand bath is recommended.
                                      81

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    d.  Fill the flask with deaired distilled water to about 3 A in. below the
        graduation and apply a vacuum slightly less than that which will cause
        vigorous boiling (as vigorous boiling may result in a loss of solids).
        To determine if the suspension is deaired, slowly release the vacuum
        and observe the lowering of the water surface in the neck of the flask.
        If the water surface is lowered less than 1/8 in., the suspension can
        be considered sufficiently deaired.

    e.  Fill the flask until the bottom of the meniscus is coincident with the
        calibration line on the neck of the flask.  Thoroughly dry the outside
        of the flask and remove the moisture on the inside of the neck by wip-
        ing with a paper towel.  Weigh the flask and contents to the nearest
        0.01 g.  Immediately after weighing, stir the suspension to assure uni-
        form temperature, and determine the temperature of the suspension to
        the nearest 0.1°C by immersing a thermometer to the middepth of the
        flask.

    f.  Carefully transfer the contents of the flask to an evaporating dish.
        Rinse the flask with distilled water to insure removal of all of the
        sample from the flask.  Oven-dry the sample to a constant weight at a
        temperature of 85 +_ 5°C.  Allow the sludge to cool to room temperature
        in a desiccator and determine the weight of the sludge to the nearest
        0.01 g.

    g.  Record all weights on the data sheet.

Computations

    The following quantities are obtained by direct weighing:

    a.  Weight of flask + water + solids at  test temperature = W-j-^g  in grams.
    b.  Weight of tare plus dry sludge in grams.   The tare weight  is  sub-
        tracted from this value to obtain the weight  of dry sludge,   Ws  .   The
        specific gravity of solids is computed to two decimal places  by  the
        equation:
                                          W K
                               G  =
                                s   ¥  + W,   - W
                                     s    bw    bws

        where    K = correction factor based on the density of water  at  20°C
                     (see Table B-l).   Unless otherwise required,  specific
                     gravity values reported shall be based on water  at  20°C.

               W   = weight of flask plus water at test temperature in grams
                     (obtained from calibration curve as shown in  Figure B-3

Possible Errors

    Following are possible errors that would cause inaccurate determinations
of specific gravity:
                                      82

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    a.   Imprecise weighing of flask and contents.   Since the  computation of
        the specific  gravity of solids  is  based on  a  difference  in weights
        which is  small in comparison with  the  weights themselves, the  same bal-
        ance should be used for calibrating the volumetric  flask and for de-
        termining the specific gravity  whenever the calibration  curve  is used.

    b.   Temperature of flask and contents  not  uniform.  Both  in  calibrating
        the flask and determining the specific gravity, utmost care should be
        taken to  insure that measured temperatures  are representative  of the
        flask and contents during the times when the  weighings are made.

    c.   Flask not clean.  The calibration  curve will  not remain  valid  if dirt
        accumulation  changes the weight of the flask.  Also,  if  the inside of
        the neck  is not clean, an irregular meniscus  may form.

    d.   Moisture  on outside of flask or inside of neck.  When calibrating the
        flask for a temperature lower than room temperature,  there is  a
        tendency  for  condensation to form  on the flask despite careful drying
        and rapid weighing.  Whenever possible, weighing should  be done at
        approximately the same temperature as  that  of the flask.

    e.   Meniscus  not  coincident with mark  on neck of  flask.   One drop  of water
        too much  makes an error of approximately 0.05 g-  This error can be
        minimized by  taking the average of several  readings at the same tem-
        perature.  When the suspension  is  opaque, a strong  light behind the
        neck is helpful in seeing the bottom of the meniscus.

    f.   Use of water  containing dissolved  solids.   It is essential that dis-
        tilled or demineralized water be used  exclusively to  insure the con-
        tinued validity of the flask calibration curve.

    g.   Incomplete removal of entrapped air from sludge suspension.  This is
        the most  serious source of error in the specific gravity determination
        and will  tend to lower the computed specific  gravity.  The suspension
        must be thoroughly evacuated or boiled and  the absence of entrapped
        air verified  as described in Procedure.  (it  should be noted that air
        dissolved in  the water will not affect the  results, so it is not
        necessary to  apply vacuum to the flask when calibrating  or after fill-
        ing the flask to the calibration mark.)
CONSISTENCY LIMITS

    The consistency limits are water contents that define the  limits  of the
various stages for a given sludge.   The principal stages  from  an engineering
standpoint are shown in Figure B-^.   The liquid limit (LL) and the  plastic
limit (PL) define the upper and lower limits, respectively, of the  plastic
range of a sludge; the numerical difference between these two  limits  expresses
the plasticity of a sludge and is termed the plasticity index  (Pi).   The
shrinkage limit (SL) defines the lower limit of the semisolid  range of a
sludge.  Detailed procedures for determining the liquid and plastic limits  are
given below, and a detailed procedure for determining the shrinkage limit is


                                      83

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also given.   Sludges containing a large  percentage  of fibres  will  not  easily
lend themselves to the consistency tests.   When the fibres  interfere with the
test procedures, this fact should be noted.

Liquid Limit Test

Definition—
    The liquid limit of a sludge is the  water  content,  expressed as a  percent-
age of the weight of ovendried sludge, at  which two halves  of a sludge pat
separated by a groove of standard dimensions will close at  the bottom  of  the
groove along a distance of 1/2 in.  under the impact of  25 blows in a standard
liquid limit device.

Apparatus—
    The apparatus should consist of the  following:

    a.  Liquid limit device,  as shown in Figures B-5 and B-6,  having a crank
        and cam to lift and then drop a  brass  cup onto  a block of  resilient
        material.  A motorized liquid limit device  may  be used,  provided  that
        it meets the specifications of the conventional device and that vibra-
        tion is imperceptible during operation.   However, comparative  tests
        should be performed to insure that the motorized device gives  the same
        results as those obtained using  the conventional device.   Several de-
        tails in the construction of the liquid limit device  are of particular
        importance.  First, the material of the base will be  Micarta Wo.  221A
        or a hard rubber of equal dynamic  resiliency.   A 5/l6-in.-diameter
        steel ball bearing dropped from  a  height of 10  in.  above the top  of
        the base will rebound at least 7-3 in.  but  not  more than 9 in.  for a
        base to be satisfactory.  The top  of the base will  be well polished,
        and rubber feet are necessary to eliminate  the  influence of the sup-
        porting table.  The cam will be  shaped so that  the  height  of the  cup
        is maintained constant for a short section  at the end of the turn
        rather than rising continuously  to the point of release (37)-   The
        weight of the cup with the cam follower will be 175 ±15 g.*   Fig-
        ures B-5 and B-6 show the cup supported by  a pin made integral with
        the cam follower; however,  a separate  pin may be used to support  the
        cup provided there is assurance  that the cup will always be removed
        from the support for shaping and grooving the soil  pat (38).

    b.  Grooving tool, conforming in general to the dimensions shown in Fig-
        ure B-5.  The critical dimensions  of the grooving tool are those  which
        govern the shape and depth of the  sludge groove. The gage for check-
        ing height of drop of the cup will be  10 +_  0.2  mm  (0.39^ +_ 0.008  in.).
        The shape of the gage may vary,  depending on the manufacturer,  but it
        should have a square edge,  not round.

    c.  Spatula, having a blade about U  in. long and about  3A in. wide.

    d.  Mixing dish or bowl.
  ^Material is not to be added to the cup to meet this requirement,


                                      Qh

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    e.   Specimen containers.   Seamless metal or glass  containers with lids are
        recommended.   The containers should be resistant  to  corrosion.

    f.   The same types of balance and oven as those for  solids  and water con-
        tent determinations.

Check and Adjustment  of Liquid Limit Device—
    Periodically, the following points will be checked.

    a.   The cam will  be shaped so that the last 1/8 in.  of movement along the
        cam before the cup drops will cause no change  in  elevation of the cup.

    b.   The pin on which the  cam follower rests should not be worn suffi-
        ciently to permit sideplay.

    c.   The screws connecting the cup to the cam follower will  be tight.

    d.   A groove should not have been worn in the cup  to  the extent that it
        can be felt distinctly by hand.  If so, the cup will be replaced.

    e.   When, at the  point of contact between the cup  and the base, either a
        dent in the base or a flat on the cup can be felt distinctly by hand,
        the worn item will be replaced or repaired.  A worn  cup can be
        remedied by moving the cam follower to obtain  a new  point of impact.
        A dent in the base can be eliminated by removing  a thin layer and
        repolishing.

    f.   The grooving  tool will be inspected to insure  that the  dimensions
        controlling the groove in the sludge are as shown in Figure B-5.  The
        grooving tool will be replaced when the width  of  the tip exceeds
        2.1 mm (0.083 in.) or is less than 1.9 mm (0.075  in.).

    g.   The height of drop of the cup will be adjusted as follows:  By means
        of the gage on the handle of the grooving tool and the  thumbscrew at
        the rear of the device, adjust the height to which the  cup is lifted
        so that the point on  the cup that comes in contact with the base (not
        the lowest point of the cup) is 10 +_ 0.2 mm (0.391* ± 0.008 in.) above
        the base, as  shown in Figure B-5.  Secure the  adjustment by tightening
        the thumbscrew on top of the device and then recheck the adjustment.
        A flashlight  is helpful in making this critical  adjustment.

Preparation of Material—
    Material will be  selected and prepared as follows.

    a.   It is essential that  the same carefully prepared sludge mixture be
        used for determining  both the liquid and plastic  limits.  Sludges of
        different plasticity  will not be mixed.  Furthermore,  if the natural
        water content is to be determined, the specimen  will be taken from an
        identical mixture to  permit valid correlations.   If  other test results
        are to be correlated  with the liquid and plastic  limits, the material
        used for the  determinations will be the same as  that tested.
                                      85

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    b.   Whenever possible,  sludges  will  be  at  the  natural water  content  when
        preparation for testing is  begun.   If  drying has occurred before test-
        ing,  the limit  values  may change.   The plasticity of  sludges  contain-
        ing significant organic content  may be highly  sensitive  to  drying.
        The effects of  drying  can be  determined by comparing  the liquid  limit
        values of specimens in "undried," "airdried,"  and "ovendried"  states.

    c.   Samples will be of  sufficient size  to  produce  150 to  200 g  of  material.
        This  amount will also  provide enough material  for performing the plas-
        tic limit test.  The sample material will  be mixed thoroughly  with
        distilled or demineralized  water until it  has  a water content  some-
        what  above the  liquid  limit (a consistency requiring  between 15  and
        20 blows to cause closure of  the groove);  with experience it becomes
        possible to judge very closely when this condition is reached.   The
        mixture will be covered with  an  airtight lid and left at least over-
        night, and preferably  for 2U  hr, and then  remixed thoroughly.

Procedure—
    The liquid limit test procedure is as follows:

    a.   Record all identifying information  for the specimen,  such as project
        name  and other  pertinent data, on a data sheet (Plate B-5 is a sug--
        gested form).

    b.   Place 50 to 80  g of the thoroughly  mixed specimen in  the brass cup and
        level it off to a depth of  approximately 1 cm.  Divide the  sludge in
        the cup with the grooving tool so that a clean, sharp groove is  formed,
        as shown in Figure  B-T-   When making the groove, hold the cup  in the
        hand  with the cam follower  upward and  draw the grooving  tool, beveled
        edge  forward, through  the specimen, downward away from the  cam fol-
        lower.  The grooving tool should always be held perpendicular to the
        cup at the point of contact,  as  shown  in Figure B-7-   With  sludges
        containing a large  amount of  organic matter it may not be possible to
        draw  the grooving tool through the  specimen without tearing the  sides
        of the groove.   In  such cases the groove may possibly be made with a
        sharp spatula,  using the grooving tool only for final checking of the
        groove.

    c.   Connect the cup to  the device and turn the crank at a rate  of two
        revolutions per second.   Count the  blows until the two halves  of the
        sludge pat come in  contact  at the bottom of the groove along a dis-
        tance of 1/2 in.  as shown in  Figure B-8.   Record on the  data sheet
        the number of blows required  to  close  the  groove.

    d.   Remove 5 to 10  g of sludge  from  the portion of the sludge pat which
        flowed together,  and place  it in a  specimen container.   Determine the
        water content of the specimen in accordance with the  procedures  for
        solids and water content determinations.   All  weighing will be accu-
        rate  to 0.01 g, and water contents  in  percent  will be computed to
        one decimal place.

    e.   Transfer the sludge remaining in the cup to the mixing dish.  Wash and

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        dry the cup and grooving tool and repeat  steps  b,  c,  and  d  for  three
        additional portions of the specimen for which the  water content has
        "been adjusted by drying.  Drying may be accomplished  by continued mix-
        ing with a spatula, aided, if desired,  by a small  electric  fan.  The
        water content adjustment for each portion will  be  sufficient to pro-
        duce a noticeable variation in the number of blows required to  close
        the groove.  The object of this adjustment is to vary the number of
        blows required to close the groove from below 25 to above 25, though
        preferably from not less than 15 to not more than  35.  It is recom-
        mended that the water content of two portions be adjusted to require
        between 15 and 25 blows and of two others to require  between 25 and
        35 blows.   Material remaining in the mixing dish will be  preserved for
        the plastic limit test.

Computations—
    Computations will be made as follows.

    a.  After all necessary data have been recorded on  the data sheet,  compute
        the water content of each specimen as follows:


            ,, .       ,            ,         weight  of water         , __
            water content, percent = 	;———5	—:—	—;	 x 100
                                     weight of ovendried sludge

    b.  Determine the liquid limit from a plot of water content versus  number
        of blows on a semilogarithmic graph.  Plot water content  on an  arith-
        metic scale (ordinate) and plot the corresponding  number  of blows on a
        logarithmic scale (abscissa) as shown in  Plate  B-5-   The  best straight
        line (called the "flow line") is drawn through  the four plotted points.
        The liquid limit is the water content corresponding to the  intersec-
        tion of this straight line and the 25-blow line on the graph.   Record
        the liquid limit to the nearest 0.1 percent water  content but omit the
        percent designation.  However, the final  results may  be reported to
        the nearest whole number.

Plastic Limit Test

Definition—
    The plastic limit of a sludge is the water content, expressed as a  per-
centage of the weight of ovendried sludge, at which the sludge begins to
crumble when rolled into a thread 1/8 in.  in diameter.

Apparatus—
    The apparatus will consist of the following:

    a.  Surface for rolling the thread, such as a fine-ground glass plate or a
        smooth tabletop of linoleum or dense, fine-grained wood.  Clean, white
        paper may be placed on the surface for rolling  provided the type of
        paper will not result in accumulations of lint  in  the specimen.

    b.  Spatula, having a blade about U in. long  and about 3A in.  wide.
                                      87

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    c.  Specimen containers,  of the type used for the liquid limit test
        procedure.

    d.  Balance and oven of the types used for liquid limit test, sensitive to
        0.01 g.

Preparation of Material—
    The material to be used for the plastic limit test will be taken from the
same carefully prepared mixture used for the liquid limit test, as described
previously.  Approximately 20 g of material is required for the plastic limit
test.

Procedure—
    The procedure will consist of the following steps:

    a.  Record all identifying information for the specimen on the data sheet
        (Plate B-5).

    b.  Take 2 to 5 g of the material remaining from the liquid limit test.
        The material will be taken at any stage of the drying process at which
        the mass becomes plastic enough to be shaped into a ball easily with-
        out sticking to the fingers when squeezed.

    c.  Shape the specimen into an ellipsoidal mass and roll it either under
        the root of the fingers, under the palm of the hand, or under the heel
        of the thumb and against the surface for rolling.  Use just enough
        pressure to roll the sludge mass into a thread 1/8 in. in diameter as
        shown in Figure B-9.*  When the diameter of the thread becomes 1/8 in.
        without crumbling, fold and knead the thread into a ball again and re-
        peat the rolling process.  Continue kneading and rolling the specimen
        until the sludge has dried to the point at which the rolled thread
        will break into numerous pieces with a diameter of 1/8 in.  and lengths
        of about 1/8 to 3/8 in. (39), as shown in Figure B-10.

    d.  Place the pieces of the crumbled thread into a specimen container and
        determine the water content.  Repeat steps b and c with another por-
        tion of the prepared material in order to check the plastic limit.
        The plastic limit will be reported as the average of the two tests if
        the two test values vary not more than 5 percent from the average;
        otherwise,  the test will be repeated.

    e.  Record all weights and computations on the data sheet.  All weighing
        should be accurate to 0.01 g, and water contents in percent computed
        to one decimal place.

Computations—
    Computations will be made as follows.

    a.  After all necessary data have been recorded on the data sheet, compute
        the plastic limit of each specimen as follows:

  *The pressure required for rolling the thread will vary greatly depending on
   the toughness of the sludge.

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                  „,   . .   , .  . .        weight of vater
                  Plastic limit = 	.  , ,  &f	,  .  ,	— x 100
                                  weight of ovendried soil

    b.   Compute the plasticity index as follows.

                  Plasticity index = liquid limit  -  plastic limit

                                   PI = LL - PL

Possible Errors—
    Possible errors that would cause inaccurate determinations  of  the  liquid
and plastic limits are listed below.

General—
    a.   Specimen not representative.  As described previously,  the liquid and
        plastic limits must be determined using the  same mixture of sludge as
        that used for determinations of natural water content or for other
        tests.

    b.   Specimen improperly prepared.   The specimens must be thoroughly  mixed
        and be permitted to cure for a sufficient  period before testing.   Er-
        roneous results may be caused by testing airdried or ovendried sludges

    c.   Inaccurate determination of water contents.   The possible  errors de-
        scribed under solids and water content determinations would greatly
        affect the computed liquid and plastic limits because of the small
        quantities of material available for the water content  determinations.

    d.   Computational mistakes.

Liquid Limit Test—
    a.   Improperly constructed or adjusted liquid limit device.

    b.   Worn parts of liquid limit device, especially at point  of  contact be-
        tween the cup and the base, or worn tip of grooving tool.

    c.   Sludge at point of contact between the cup and the base.  Removal of
        the cup for shaping and grooving the sludge  pat will also  insure that
        the bottom of the cup and the top of the base are clean.  Any  sludge
        that has dropped onto the base can be removed with one stroke  of the
        back of the hand just before replacing the cup.

    d.   Loss of moisture during test.

    e.   Large percentage of fibres.

Plastic Limit Test—
    a.   Rolling thread under fingers.  The fingers will break the  thread
        prematurely.

    b.   Incorrect final thread diameter.  A length of 1/8-in.-diameter metal
        rod close at hand will help in estimating this diameter accurately.

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    c.  Stopping the rolling process too soon.  If there is any doubt as to
        whether the thread has crumbled sufficiently, it is better to roll the
        thread once more than to stop the process too soon.

Shrinkage Limit Test

Definition—
    The shrinkage limit of a sludge is the water content, expressed as a per-
centage of the weight of the ovendried sludge, at which further loss in mois-
ture will not cause a decrease in its volume.  As part of the shrinkage limit
test, the shrinkage ratio  R  and linear shrinkage  Ls  are also usually de-
termined.  The shrinkage ratio is defined as the ratio between a given volume
change and the corresponding change in water content above the shrinkage limit.
The linear shrinkage is defined as the decrease in one dimension of a sludge
mass, expressed as a percentage of the original dimension, when the water con-
tent is reduced from a given value to the shrinkage limit.

Apparatus—
    The apparatus should consist of the following:

    a.  Evaporating dish; a porcelain evaporating dish approximately U-l/2 in.
        in diameter is recommended.

    b.  Shrinkage dish; a circular porcelain or monel metal dish 1-3A in.  in
        diameter and 1/2 in. in height may be sufficient.

    c.  Glass cup, about 2 in.  in diameter and about 1 in. in height with the
        top rim ground smooth and flat.

    d.  Glass plate, 3 by 3 by l/l6 in. fitted with three metal prongs for
        immersing the sludge pat in mercury as shown in Figure B-ll.

    e.  Mercury, sufficient to fill the glass cup to overflowing.

    f.  Spatula, having a blade about h in.  long and about 3 A in.  wide.

    g.  Steel straightedge.

    h.  Balances and oven same as those for liquid limit tests.

Preparation of Materials—
    Approximately 30 g of sludge will be obtained from the thoroughly mixed
portion of the material.  The material to be used in the test should be pre-
pared in the same manner as that described for the liquid limit test.

Procedure—
    The procedure is as follows.
    a.   Record all identifying information for the specimen on a data sheet;
        see Plate B-6 for suggested form.

    b.   Place the specimen in the evaporating dish and mix it thoroughly with
        distilled water.  The amount of water added will be sufficient to make
                                      90

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      the sludge wet enough to be readily vorked  into  the  shrinkage dish
      without inclusion of air bubbles.   The  amount  of water  required to
      give sludge the desired consistency is  equal to  or slightly greater
      than the liquid limit.

  c.   Coat the inside surface of the shrinkage  dish  with a thin layer of
      petroleum jelly or similar compound to  prevent the sludge from adher-
      ing to the dish.   Place an amount  of the  wetted  sludge  equal to about
      one-third the volume of the dish in the center of the dish and tap the
      dish on a firm surface, causing the sludge  to  flow to the outer edges.
      Continue tapping the dish until all air bubbles  are  eliminated from
      the sludge.  Repeat this step for  two more  layers.   The final layer
      will fill the dish completely, with some  excess  sludge  allowed to
      stand above the rim of the dish.   Strike  off the excess sludge with a
      straightedge and remove all sludge adhering to the outside of the dish.

  d.   Weigh the full dish of sludge immediately and  record the weight on the
      data sheet as the weight of dish and wet  sludge.  Allow the sludge pat
      to air-dry until a definite color  change  takes place and then oven-dry
      to a constant weight.  Record the  ovendried weight as the weight of
      the dish and dry sludge.  Determine and record the weight of the empty
      dish.

  e.   Determine the volume of the shrinkage dish  by  filling the dish to
      overflowing with mercury,* removing the excess by pressing a glass
      plate firmly over the top of the dish,  and  weighing  the amount of mer-
      cury required to completely fill the dish.  The  weight  of the mercury
      divided by its density (13-53 g per cm3)  equals  the  volume of the in-
      side of the shrinkage dish.  Record the volume of the shrinkage dish,
      which is equal to the volume of the wet sludge pat.

  f.   Place the glass cup in the evaporating  dish and  fill it with mercury
      to overflowing.  Remove the excess mercury  by  placing the glass plate
      with the three metal prongs firmly over the cup; take care not to trap
      air under the plate.  Empty the excess  mercury from  the evaporating
      dish and remove all mercury adhering to both the glass  cup and the
      evaporating dish with a brush.

  g.   Determine the volume of the sludge pat  by immersing  the pat in the
      mercury contained in the cup, using the glass  plate  with the three
      metal prongs as shown in Figure B-ll.  Take care not to trap air under
      the sludge pat or glass plate.  Determine the  weight of the displaced
      mercury and compute its volume, as indicated in  step e  above, and re-
      cord it as the volume of the dry sludge pat.

  h.   Record all information pertaining to the  sludge  specimen such as
      weights, volumes, etc., on the data sheet,  Plate B-6.
*Caution should be exercised in handling mercury.   Mercury may have toxic
 effects, particularly if spilled on the floor in areas without good venti-
 lation.  See Handling of Mercury below.
                                    91

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Computations —
    Water Content — The water content  w  of the sludge at the time it was
placed in the shrinkage dish is determined as follows:

                                     W
                                 w = r^ x 100
                                     W
                                      s

where  W  = weight of water in  g ,  obtained by subtracting the weight of the
        W   shrinkage dish plus dry sludge from the weight of the dish plus
            wet sludge

       W  = weight of ovendried sludge in  g ,  obtained by subtracting the
        3   weight of the shrinkage dish from the weight of the dish plus dry
            sludge

    Shrinkage Limit — The shrinkage limit, SL, is calculated as follows:

                                    /V - V       \
                           SL = w -  — - - * 100
where  SL = shrinkage limit

        w = water content of wet sludge pat when placed in shrinkage dish,  ex-
            pressed as a percentage of the weight of ovendried sludge

        V = volume of wet sludge pat,  cirP

            weight of displacement mercury in evaporating dish
        s     specific gravity of mercury (13.53 g per cm3)
          = volume of ovendried sludge pat, cm^

       W  = weight of ovendried sludge pat, g
        S
    Shrinkage Ratio — The shrinkage ratio  E  will be determined by the fol-
lowing equation:

                                        W
where  Ws  and  Vs  are the same as given above.
    Linear Shrinkage — The linear shrinkage  Ls  will be determined by the fol-
lowing equation:
                           L  = 100
                            s
L     3/_J£0_\
I1  ~   \c  +  100 y
where  C = volumetric change from a given water content  w  (usually LL)

       C = (w - SL)R
                                      92

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Possible Errors —
    Besides errors in the preparation of sludge mixtures given under Liquid
and Plastic Limits, following are possible errors that would cause inaccurate
determinations of shrinkage limit:

    a.  Inside of shrinkage dish not lubricated.  If the sludge adheres to the
        shrinkage dish, the sludge pat may crack during drying.

    b.  Air bubbles included in sludge pat.

    c.  Sludge pat dried too rapidly.  To prevent the sludge pat from cracking,
        it should be dried slowly, first in the humid room and then in the air
        of the laboratory, until a definite change in color is noted.  Only
        then should it be placed in the oven.

    d.  Air bubbles trapped beneath sludge pat or glass plate when immersing
        pat in mercury.

Handling of Mercury
    Properties — Mercury is an odorless silver-white liquid at normal tempera-
ture and pressure.  Mercury has the property of forming amalgams with most
metals, with the exception of platinum and iron.  It is highly volatile,
vaporizing at room temperature to form vapors that are highly toxic.  Mercury
has a specific gravity of 13.6, a boiling point of 356. 9°C, and a freezing
point of -38.9°C.

    Health Hazards — The air concentration of mercury vapor corresponding to
the equilibrium vapor pressure at room temperature (20°C) is approximately
20 mg per m3, or 200 times the safe concentration of 0.1 mg per m3 for con-
tinuous exposure (8 hr per day, 5 days per week); safe concentrations for
shorter periods have not been proposed.  Inhalation of mercury vapor of con-
centrations greater than 0.1 mg per m3 over a long period of time can cause
chronic poisoning.  The initial symptoms of poisoning may include gingivitis,
digestive disturbance, fine tremor of the extremities, irritability, excessive
emotional response, and exaggerated salivation.  These symptons may increase
in severity and may result in permanent disability.  Exposure to concentra-
tions far greater than the maximum allowable concentration for short periods
of time can cause acute illness.  The exact nature, concentration, and dura-
tion of exposure determine the type and severity of symptoms.  Although inha-
lation of mercury vapor is by far the greatest  avenue of entry to the body,
ingestion and absorption through the skin are also possible.

    Use — Whenever possible, use of mercury for  test purposes should be avoided.
Personnel working in an area where mercury is used should be made aware of its
hazards .

    Detection — Direct reading units for determining the  concentration of mer-
cury vapor  are available from the following  sources:

    Mine  Safety Appliances Company
     211 N.  Braddock Ave.
     Pittsburgh, Pennsylvania  15208
                                       93

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    Union Industrial Equipment Corporation (UNTCO)
    150 Cove St.
    Fall River, Massachusetts  02720

    Acton Associates
    1180 Raymond Blvd.
    Newark, New Jersey  07102

    Beckman Instruments, Inc.
    2500 Harbor Blvd.
    Fullerton, California  9263^

    Handling—The precautions listed below should be observed when handling
mercury:

    a.  Mercury should not be heated without elaborate control because of the
        rapid increase of vapor pressure with increase in temperature.

    b.  Eating and smoking should not be permitted in areas where mercury is
        handled.  Hands should be thoroughly washed after handling mercury.

    c.  A change of clothes should be available if clothing is contaminated.

    d.  Respiratory protection should be available where there is a possi-
        bility of contamination.

    e.  All laboratories handling mercury should have a precise plan to be
        followed in decontamination after a mercury spill.   Some general pro-
        posals are:

        (l) Maximum general exhaust ventilation and local exhaust should be
            effected.  Windows should be opened.

        (2) A vacuum flask or a vacuum cleaner designed for removal of mercury
            should be put into service immediately to recover the mercury.

        (3) The area should be decontaminated by treating with flowers of
            sulfur or other decontaminant.

        (k) Effectiveness of decontamination should be verified with a mercury
            vapor detector-

    Facilities—In facilities where mercury is handled the measures listed
below should be taken.

    a.  Floors of areas should be free of cracks and the intersection of the
        wall and floor should be fitted with a cove.

    b.  Recirculation of air in room should be discouraged because of the
        possibility of buildup of mercury vapor.

    c.  Mercury manometers should be provided with traps to insure that there
        will be no spillage of mercury into a process line or into room.

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    d.  Precision equipment should be removed from areas where contamination
        with mercury is possible.

    Transportation and Storage—When transporting and storing mercury the  fol-
lowing precautions should be taken.

    a.  Mercury containers should be placed in a tray when transported within
        the laboratory; metal or continuous type (nonwelded)  plastic  con-
        tainers are preferable to glass ones.

    b.  Mercury containers should be stored in pans that will contain any
        spillage.
PERMEABILITY

    Permeability is a measure of the rate of flow of water or fluid through  a
material.  The physical structure and the arrangement of constituent particles
greatly affect the size and continuity of the spaces (voids or pores) between
particles.  These voids control the rate of flow.   Such material properties
and behavior as drainage, consolidation, seepage,  and stability are highly
dependent on the material permeability.  Due to the large variation in physi-
cal structure and composition of pulp and paper-mill sludges, the permeability
of sludges will show a wide variation.

    The flow of water through a sludge medium is assumed to follow Darcy's law:


                                   q = kiA

where  q = rate of discharge through a sludge of cross-sectional area,  A

       k = coefficient of permeability

       i = hydraulic gradient, the loss of hydraulic head per unit distance  of
           flow

The coefficient of permeability,  k  (often termed "permeability"), is defined
as the rate of discharge of water at a temperature of 20°C under conditions  of
laminar flow through a unit cross-sectional area of a sludge medium under a
unit hydraulic gradient.  The coefficient of permeability has the dimensions
of a velocity and is usually expressed in centimetres per second.

    Permeability computed on the basis of Darcy's law is limited to the condi-
tions of laminar flow and complete saturation (amount of water) of the voids.
In turbulent flow, the flow is no longer proportional to the first power of
the hydraulic gradient.  Under conditions of incomplete saturation, the flow
is in a transient state and is time-dependent.  Permeability decreases as the
degree of consolidation increases, because of a reduction of the volume of
voids.

    There are several standard procedures for investigating permeability and


                                      95

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these can be found in Reference 36.  Permeability determination procedures
recommended for the purposes of this manual will be presented in the section
on Consolidation Tests belov.  An investigation of various factors affecting
the permeability of sludges can be found in Reference 2.
ASH AND ORGANIC CONTENTS

    Pulp and paper-mill sludge has organic material that is generally com-
bustible and mineral materials that are incombustible and ash-forming.

    A procedure (35) for determining ash content is to fire an ovendried
sludge sample in a muffle furnace at a temperature of 600°C.   The specimen
should be fired until it has obviously been reduced to an ash (probably at
least 3 hr).  An alternate procedure (25) is to fire the specimen in a
crucible over a bunsen burner, in which case extreme care must be taken that
the ash is not carried away by the hot air currents.  For either method, the
ash content  AC  is determined from the equation


                   /      . N   weight of ash or residue   n,._,
                A   percent  = —j°	^TT	~—^~^	 x 10°
                 c               dry weight of sludge


    Percent organic content  Oc  can be considered (25) equal to


                                 0  = 100 - A
                                  c          c


This is an approximate method and can be in error from 5 to 15 percent, be-
cause more than organic matter can be burned off the specimen.  The ash and
organic contents for a sludge can be added to the previously suggested data
sheets for the same sludge.
PHYSICAL DESCRIPTION OF FIBRES

    For future use, analysis, and understanding of the behavior of pulp and
paper-mill sludges, some type of physical description of the fibrous content
should be made.  The description can be added or attached to the previously
suggested data sheets.  The following is a list of suggested descriptors that
may be modified or added to:

    a.  Type of fibres.

    b.  Percent different average fibre lengths and diameters.   Fibres could
        be separated by a set of different size strainers or sieves.

    c.  Average fibre length-to-diameter ratios (aspect ratios).

    d.  Average tensile strengths of fibres.
                                      96

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CONSOLIDATION TEST

    The procedures presented in the following paragraphs are from Reference 36;
however, Reference 3^ is also applicable.  Consolidation is the process  of
gradual transfer of an applied load from the pore water to the sludge struc-
ture as pore water is squeezed out of the voids.   The amount of water that
escapes depends on the size of the load and compressibility of the sludge.
The rate at which it escapes depends on the coefficient of permeability,
thickness, and compressibility of the sludge.  The rate and amount of con-
solidation with load are usually determined in the laboratory by the one-
dimensional consolidation test.  In this test, a laterally confined sludge is
subjected to successively increased vertical pressure, allowing free drainage
from the top and bottom surfaces.

Apparatus

    The apparatus should consist of the following:

    a.  A consolidometer with a rigid base, a consolidation ring, porous
        stones, a rigid loading plate, and a support for a dial indicator
        (Figure B-12).  The various metal parts of the consolidometer will be
        of the same noncorrosive material.  All-plastic or combination plastic
        and metal consolidometers may also be used to reduce electrochemical
        effects.  The consolidometer will be of the fixed-ring type and  will
        have a rigid base with a recess for supporting the bottom porous  stone
        and for seating and attaching the consolidation ring.  The upper  sur-
        face of the recess will be grooved to permit drainage.  The base  will
        also have (l) an inundation ring to permit submergence of the specimen
        in water to prevent evaporation of water from the specimen during the
        test, and (2) suitable connections and a standpipe for making perme-
        ability tests.

    b.  Consolidation ring will completely and rigidly confine and support the
        specimen laterally.  The inside diameter of the ring should not  be
        less than 2-3A in. and preferably not less than k in.; use of larger
        rings for specimens of larger diameter, particularly with the fixed-
        ring consolidometer, will reduce the percentage of applied load
        carried by side friction and consequently will provide more accurate
        results.  Normally, the ratio of the height of ring to inside diameter
        of ring should be between lA and 1/6.  The consolidation ring may be
        lined with a material such as Teflon to reduce the friction between
        the ring and the specimen.  A stainless steel ring is preferable for
        specimens containing abrasive particles.

    c.  Porous stones more pervious than the specimen of sludge should be used
        to permit effective drainage.  For routine testing, stones of high
        porosity should be used.  The diameter of the porous  stones will be
        such as to prevent the squeezing out of sludge through the clearance
        spaces between the ring and stone and to permit free  compression of
        the specimen without binding; to minimize the possibility of binding,
        the sides of the upper porous stone of the fixed-ring consolidometer
        should be slightly tapered away from the  specimen.  A clearance  of
                                      97

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        about 0.010 to 0.015 in.  around the stone generally may be adequate;
        however, if very soft sludges are tested, a smaller clearance may be
        desirable or retainer rings may be used as shown in Figure B-12.   De-
        tails of a typical retainer ring are shown in Figure B-13.  The porous
        stones should be cleaned after every test, preferably in an ultrasonic
        cleaner or by boiling and flushing.

    d.  Loading devices of various types may be used to apply load to the
        specimen.  The most commonly used is the beam-and-weight mechanism.
        The loading device should be capable of transmitting axial load to the
        specimen quickly and gently.  Also, the equipment should be capable of
        maintaining the load constant for at least 2U hr.  The equipment
        should be calibrated to insure that the loads indicated are those ac-
        tually applied to the sludge specimen.

    e.  Dial indicator.  A dial indicator reading counterclockwise, with  a
        range of 0.50 in. and graduated to 0.0001 in., is recommended.

    f.  Other items needed are:

        (l) Glass or plastic tubing for standpipe.

        (2) Timing device, a watch or clock with second hand.
        (3) Centigrade thermometer, range 0 to  50°C, accurate to 0.1°C.

        (M Deaired distilled water-

        (5) Filter papers, glass plates, and a  circular metal plate,  approxi-
            mately 0.05 in. thick and slightly  less in diameter than the  in-
            side of the consolidation ring.

        (6) Apparatus necessary to determine water and solid contents and
            specific gravity.

        (?) Manometer board or suitable scales  for measuring levels in
            standpipe.

Preparation of Specimens

    Specimens will be prepared in a humid room  to prevent evaporation of
sludge moisture.  With the consolidation ring set on a glass plate, a test
specimen can be prepared by hand-placing sludge material into the ring.   The
sludge should be placed in uniform layers about lA in.  thick.   Care should be
taken to insure that no space in the ring is left unfilled and that the speci-
men is made as uniform as possible.  Carefully  true the surface flush with the
specimen ring.  Force the metal plate into the  top of the specimen until  it  is
flush with the top of the ring, thereby providing a recess for the top porous
stone.  Remove the metal plate.

Procedure

    The procedure shall consist of the following steps:

    a.  Record all identifying information for  the specimen, such as project

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    number and other pertinent data, on the data sheets  (Plates  B-7  and
    P-8 are suggested forms); note any difficulties encountered  in prepa-
    ration of the specimen.  Measure and record height and cross-sectional
    area of the specimen.  Record weight of specimen ring and glass  plate.
    After specimen is prepared, record the veight of the specimen plus
    tare (ring and glass plate).  It is recommended that water content and
    specific gravity tests be made on representative material for every
    consolidation test specimen.  Record the wet weight  of the material
    used for the water content determination on the data sheet.

b.  Fill the grooves in the base of the consolidometer with water.   Fit
    the porous stone (previously saturated with water) into the  base of
    the consolidometer.  Add sufficient water so that the water  level is
    at the top of the porous stone.  Place a moist filter paper  (Whatman
    No. 1 or equal) over the porous stone.  (Be very careful to  avoid
    entrapping any air during the assembly operations.)   Place the ring
    with the specimen therein on top of the porous stone.  Secure the ring
    to the base by means of clamps and screws.

c.  Place a moist filter paper on top of the specimen, and then  place the
    previously saturated top porous stone and the loading plate  in
    positiqn.

d.  Place the consolidometer containing the specimen in  the loading  device.

e.  Attach the dial indicator support to the consolidometer, and adjust it
    so that the stem of the dial indicator is centered with respect  to the
    specimen.  Adjust the dial indicator to permit the approximate maximum
    travel of the gage but still allow measurement of any swelling.

f.  Adjust the loading device until it just makes contact with the speci-
    men.  The seating load should not exceed about 0.01  ton/ft2  (l ton/ft
    « 1 kg/cm2).

g.  Read the dial indicator, and record the reading on a data sheet
    (Plate B-9 is a suggested form).  This is the initial reading of the
    dial indicator.

h.  With the specimen assembled in the loading device, apply a load  of
    0.25 ton/ft2 to the specimen and immediately inundate the specimen by
    filling the volume within the inundation ring or the chamber surround-
    ing the specimen with water.  Place a thermometer in the water,  and
    record the temperature at 2-hr intervals.  To obtain reliable time-
    consolidation curves the temperature  should not vary more than  +2°C
    during the test.  A load of 0.25 ton/ft2 should be enough to prevent
    swelling, but if swelling occurs apply additional load increments
    until swelling ceases.  Were the specimen permitted to swell, the re-
    sulting void ratio-pressure curve would have a more  gradual curvature.
 i.
Continue consolidation of the  specimen by applying  the  next  load  in-
crement.  The following loading schedule is  considered  satisfactory
for routine tests:   0.25, 0.5,  1.0,  2.0, U.O,  8.0,  and  l6.0  tons/ft2,
                                  99

-------
    the total load being doubled by each load  increment.

j.  Observe and record on the data sheet (Plate  B-9)  the  deformation as
    determined from dial indicator readings  after  various elapsed times.
    Readings at 0, 1/4, 1/2,  1,  2-1/4,  4,  6-1/4, 9, 12-1/4,  l6,  20-1/4,  25,
    36, and 49 min, and 1, 2, 4,  8,  and 24 hr  for  each load  increment are
    usually satisfactory.   A  timing device should  be  located near the con-
    solidometer to insure accurately timed measurements.   Allow  each load
    increment to remain on the specimen for  a  minimum of  24  hr.   It  is de-
    sirable that the duration of all load increments  be the  same.  During
    the course of the test, plot the dial reading  versus  time data for
    each load increment on a  semilogarithmic plot  as  shown in Plate  B-10.
    Plot the dial reading on  an  arithmetic scale (ordinate)  and  the  corre-
    sponding elapsed time on  a logarithmic scale (abscissa)  as shown in
    Figure B-l4.  The curve shown in Figure  B-l4 can  be converted into a
    time-consolidation curve  using the  theory  of consolidation.   The
    100 percent consolidation or the completion  of the primary consolida-
    tion is arbitrarily defined  as the  intersection of the tangent to the
    curve at the point of inflection, with the tangent to the straight-
    line portion representing the secondary  time effect.   The construction
    necessary for determination  of the  coordinates representing  100  per-
    cent consolidation and other degrees of  consolidation is shown in Fig-
    ure B-l4.  In addition to the curve above, plot the dial reading
    versus time-data for each load increment on  a  square  root of time plot
    as shown in Plate B-ll.  Plot the dial reading on the arithmetic scale
    and the corresponding elapsed time  on the  square-root scale  as shown
    in Figure B-15.  The 90 percent primary  consolidation is defined as
    the point on the data curve  cut by  a line  coinciding  at  zero time with
    a straight line through the  early portion  of the  data plot and having
    an inverse slope 1.15 times  the straight line  slope.   After  first
    drawing a straight line through the data,  a  second line  is drawn
    having all abscissas 1.15 times as  large as  corresponding values on
    the first line.  The construction necessary  for determining  90 percent
    primary consolidation is  shown in Figure B-15.  Calculate the 100 per-
    cent primary compression  value and  time  (lOO percent  compression
    = 1.1111 x 90 percent compression).   Use the 100  percent compression
    value and time to establish  the 100 percent  point in  Figure  B-l4.

k.  Record on a data sheet (Plate B-12  is a  suggested form)  the  dial read-
    ing for each load increment  corresponding  to a selected  time (usually
    24 hr) at which primary consolidation has  been completed for all
    increments.

1.  After the specimen has consolidated under  the  maximum load,  remove the
    load in decrements, taking three-quarters  of the  load off successively
    for each of the first two decrements and as  considered desirable
    thereafter.  Take readings of the dial indicator  as each decrement is
    removed to determine the  rebound of the  specimen.   Observe,  record,
    and plot the dial readings versus time;  loads  should  not be  removed
    until the dial readings are  relatively constant with  time or until the
    dial reading versus logarithm of time curve  indicates completion of
    rebound.  The final load  at  the end of the rebound cycle should  be
                                  100

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    0.1 ton per sq ft or less, and this load should be maintained for
    24 hr in order to reduce to a tolerable amount the error in the final
    water content determination caused by swelling.

m.  When the dial readings indicate no further significant rebound, remove
    the dial indicator and disassemble the apparatus.   Carefully blot any
    excess water from the ring and surface of the specimen, eject the
    specimen into a dish of known weight, and weigh the dish and wet
    specimen; then oven-dry the wet specimen to constant weight for water
    content determination.  Record information on Plate B-J.

n.  At the end of the consolidation phase under each load increment, a
    falling-head permeability test should be conducted.  Identifying in-
    formation for the specimen is entered on the data sheet (Plate B-8 is
    a suggested form).  A permeability test apparatus setup is also shown
    in Figure B-12.  The net head on the specimen may be increased by use
    of air pressure; however, the pressure on the specimen void water
    should not exceed 25 to 30 percent of the vertical pressure under
    which the specimen has consolidated.

o.  Determine (as shown in Figure B-l6) and record the height of capillary
    rise,  hc , for the standpipe.

p.  Determine and record the area of the standpipe.

q.  Measure and record the initial height  L , the cross-sectional area of
    the specimen  A , and the diameter of the specimen  D  .

r.  Determine and record the height of tailwater  h^  (shown in Fig-
    ure B-12).

s.  Record the initial dial reading  D0  (same as in step g).

t.  For each load increment conduct two permeability tests.  If the two
    tests give very different permeability values, conduct tests until the
    permeability value is consistent.

u.  For each load increment record the load and the dial reading  D]_  at
    the end of compression.

v.  Raise the head of deaired distilled water in the standpipe above the
    overflow level of the consolidometer.  The difference in head should
    not result in an excessively high hydraulic gradient during the test.

w.  Begin the test by opening valve A.  Start the timer.  As the water
    flows through the specimen, measure and record the initial height of
    water in the standpipe  h-j_ , in centimeters, at initial time  to , and
    the final height of water  h2 , in centimeters, at final time  tf .

x.  Observe and record the temperature of the water in the consolidometer.
                                  101

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Computations

Consolidation Tests—
    a.  From the recorded data compute and record on the data sheet,  Plate B-7,
        the initial and final water contents.   Compute also the height of
        solids,  void ratio before and after test, initial and final degree of
        saturation, and dry density "before test using the following equations.
        Equations in brackets are based on units of measurements shown in
        Plate B-7.
          Height of solids  H  =
                             S    JT.
                                                     H  -  H
                                                         c
                       Void ratio  before  tests   e   =  ———-
                                                o      H
                                                   Hf  -  Hs
                       Void ratio  after  test   e   =  —	
                                              I     n
w
s
Av r*1 v -\/
x (j x Y
S W
W
s
.A. ^ LJ x |
s

x 2.5^ in-
                                                          H
             Initial degree of saturation,  percent   S   =
                                                          wo
                                                     o    H  -  H
                                                          100
      Final degree of saturation, percent  S  =
                                                          'wf
                                                                x  100
                               W
                                g
Dry density before test  Y, = ^	r
                          d   n x A
                                               W   x 62.
                                                s
                                              H  x A  x
                                                           Ib per  cu  ft
        where  W  =  weight  of  dry  sludge,  g
                S
                                       2
                A  =  area  of specimen,  cm

               G  =  specific gravity of solids
                                                  3
               Y  =  unit  weight  of water,  g per cm

                H  =  height  of  specimen, in.

               H  =  height  of  specimen at  end of test = H - AH  , in., where
                    AH  is  the net change  in height of specimen
                                         W
H   = original height of water =
 wo                              A x
                                          wo
                                             w
                                               W
                                                       wo
                                           A x i x 2.54

where  W   = weight of water in specimen before test, g
                                                               in.

                                     102

-------
                               w            w
H   = final height of water =	 =	;	_ ,_<  in.
 wf            &              A x y     A x l x 2.54
                                   v

where  W   = weight of water in specimen after test, g
        wi

The purpose of computing the degree of saturation at the "beginning and
end of the test is to o~btain a check on the accuracy of the data
observed and recorded.  An appreciable variation from 100 percent in
the computed degree of saturation at the beginning of the test for
specimens that are known to be completely saturated may indicate the
presence of gas or air in the specimen, or an error in the data or
computations.

From data sheet (Plate B-9) or from dial reading-time plots
(Plates B-10 and B-ll), obtain the final dial reading for each load
increment that corresponds to the selected time interval (usually
2k hr), and record these values on the data sheet (Plate B-12).  The
height of voids  Hv  corresponding to any given load is equal to the
initial height of voids (H - Hs) minus the change in height (AH).  The
change in height of the specimen is equal to the accumulative change
of the dial readings.  Compute the void ratios of the specimen corre-
sponding to different load increments.  The void ratio is numerically
equal to the height of the voids divided by the height of solids.  Com-
pute and record in Plate B-12, for each increment of pressure, the co-
efficient of consolidation  C   as follows:
                             v
                                0.8U8 ^
                          C  =
                                   ^90                     /

                                 AH  + AH
                        TJ  — TJ   -. - -  	£_
                        HI - H -     2


where   H  = average height of the specimen for the load increment

       t   = time in seconds for 90 percent primary consolidation from
             the square root of the time plot for the load increment

       AH  = change in height for the previous load increment

       AH  = change in height for the load increment being considered

Compute and record in Plate B-12, for each load increment of pressure,
the coefficient of secondary consolidation  Ca  (see Figure B-lU), as
follows:

                         AH             AH

                         IT            IT    AHs
             C  =         H              H       s
              a    log of one cycle      1      H


                              103

-------
        where  AH  = decrease in specimen height over the above log cycle

                 H = initial height of specimen at beginning of test for each
                     load increment

Permeability Tests—
    Compute and record in Plate B-8, for each load increment of pressure, the
coefficient of permeability  ^-20 >  as ^ °H°'W'S:

                                  /      h  - Ah'

                         k20 = t~ (10S10 h2 - Ah j RT


where   C = constant = (2.303 x a)/A
                                 2
        a = area of standpipe, cm
                                2
        A = area of specimen, cm

        L = height of specimen at end of load increment,  cm

        t = elapsed time of permeability test,  sec

       h  = initial height of water in standpipe,  cm

       hp = final height of water in standpipe, cm

       Ah = corrected tailwater = h,  + h  , cm
                                   t    c
       h  = height of tailwater, cm
        "0
       h  = capillary rise, cm

       R  = correction factor for viscosity of water at 20°C obtained from
            Table B-2

Presentation of Results

    The results of the consolidation tests will be shown on the report forms,
Plates B-10, B-ll, and B-13.  The data will be shown graphically in terms of
time-consolidation curves in the form shown as Plates B-10 and B-ll and in
terms of void ratio-pressure and void ratio-permeability curves in the form
shown as Plate B-13.  To obtain the void ratio-pressure curve, the void ratio
e  is plotted on the arithmetic scale (ordinate) and the corresponding pres-
sure  p , in tons per square foot,  on the logarithmic scale (abscissa) as
shown in Figure B-1T.  The compression index  GC  will be determined and shown
on the report form (Plate B-13).

    The slope of the straight-line  portion of the  pressure-void ratio curve on
a semilogarithmic diagram is known  as the compression index  C  .   The com-
pression index is defined by the equation

-------
                                      e  - e
                           C  -	
                            c   log1Q p2 -

where  p-j_  and  p2  are selected pressures from the straight-line portion of
the curve, and  e-^  and  e2  are the corresponding void ratios.   The compres-
sion index is a measure of the compressibility of a sludge.   An example of the
computation of  Cc  is shown in Figure B-17.   For simplification,  p2  is
often chosen to be 10 times  p  , in which case the denominator becomes unity.

    If permeability tests are performed in conjunction with the consolidation
test, the coefficient of permeability for each load increment will also be
plotted in the form shown as Plate B-13.

Possible Errors

    Consolidation Tests—Following are possible errors that would cause inac-
curate determinations of consolidation and permeability characteristics:

    a.  Specimen not completely filling ring.  The volume of the specimen must
        be exactly that of the consolidation ring, otherwise there will not be
        complete lateral confinement.

    b.  Galvanic action in consolidometer.  To prevent changes in the consoli-
        dation characteristics of the specimen due to galvanic currents,  all
        metal parts of the consolidometer should be of the same noncorrosive
        material; it is preferable that all such parts be made of plastic.

    c.  Permeability of porous stones too low.  The measured rate of consoli-
        dation can be markedly affected by the permeability of the porous
        stones.  The stones should be cleaned after every test to remove em-
        bedded sludge particles.

    d.  Friction between specimen and consolidation ring.  Soil tests have
        shown that over 20 percent of the load applied to a specimen can be
        lost by side friction in a fixed-ring consolidometer.  The effect of
        side friction can be reduced by (l) using a larger diameter specimen,
        (2) using a thinner specimen, and (3) lining the consolidation ring
        with Teflon.

    e.  Inappropriate load increment factor.   Depending on the purpose of the
        test, a load increment factor of 2.0  (that is, of doubling the total
        load by each load increment) may not be satisfactory.

    f.  Unsatisfactory height (or thickness) of specimen.  The height of the
        specimen will determine how clearly can be detected the break in the
        time-consolidation curve that represents completion of primary con-
        solidation.  Depending on the character of the sludge, if the specimen
        is too thin, the time to 100 percent consolidation may be too rapid,
        while  if too thick, the break in the curve may be obscured by second-
        ary compression.  Also, when a load increment factor smaller than 2.0
        is used, the thickness of the specimen may have to be increased to
                                      105

-------
        cause enough deformation during primary consolidation to define the
        "break in the curve.

    Permeability Tests—Following are possible errors that would cause inac-
 curate determinations of the coefficient of permeability:

    a.  Stratification or nonuniform compaction of the sludge.  If the speci-
        men is compacted in layers, any accumulation of fines at the surface
        of the layers will reduce the measured coefficient of permeability.

    b.  Incomplete initial saturation of specimen.

    c.  Excessive hydraulic gradient.  Darcy's law is applicable only to con-
        ditions of laminar flow.

    d.  Air dissolved in water.  No other source of error is as troublesome as
        the accumulation of air in the specimen from the flowing water.  As
        water enters the specimen, small quantities of air dissolved in the
        water will tend to collect as fine bubbles at the sludge-water inter-
        face and reduce the permeability at this interface with increasing
        time.  The method for detecting and avoiding this problem is consis-
        tency of the permeability values.

    e.  Leakage along side of specimen in consolidometer-
VANE SHEAR TEST

    In order to obtain a measure of the undrained sludge shear strength
existing in the field for slope analysis and design,  in situ vane shear tests
should be conducted.  The vane shear test should be run at every 2 ft of depth
from the top of the sludge to the bottom.  Three locations (one-third points)
along each eventual slope should be investigated.  The locations should be
about at a distance equal to the landfill height plus 5 ft back from the bot-
tom point at the interface between the sludge and dike.  The following equip-
ment and procedures are from Reference hi.   Equipment setup for the vane
shear test is shown in Figure B-l8.

Torque Assembly

    Requirements for the torque assembly include a gear reduction device ca-
pable of producing constant angular rotation of 1 to  6 deg/min, a calibrated
proving ring with a dial gage* for force measurement,  a means of measuring an-
gular rotation in degrees, and thrust bearings to support vane at ground sur-
face.  Bearings will be of the type arranged to minimize friction while pre-
venting lateral movement of the vane.  The  gear reduction and proving ring
device will be calibrated to measure applied torque with an error of less than
5 percent.

Procedure

    The following steps describe the procedure for the vane shear test.


                                      106

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Advancing Borehole—
    Using rotary or wash boring methods, advance "borehole with or without cas-
ing to a point no closer than 18 in. above intended test elevation,  maintain-
ing as close to vertical alignment as practical.  Use the following cleanout
procedure and maintain hole full of drilling fluid prior to and during test.

    With or Without Casing—Cleaning of borehole with or without casing should
not be done through open-end drill rod or sampling spoon.

    Jetting—Downward or sideward jetting is not permitted when cleaning below
casing.  Use any jet auger that deflects the flow of water or drilling fluid
upward.

    Jet Bits—Cleanout with jet bits that direct the flow downward or sideward
is permitted within the casing, but should not be done within 18 in.  of in-
tended top of test elevation.

    Sand Pump or Bailer—Do not use sand pump or bailer within 18 in. of in-
tended test elevation.

    Viscous Drilling Fluid—Viscous drilling fluid should be used to prevent
excess swell and disturbance in the vicinity of the intended test.

Advancing Vane—
    Slowly lower vane to bottom of hole and push or jack the additional 18 in.,
recording force necessary to advance vane.

Recording; Maximum Torque  T   —
	max
    Immediately after vane is in position with torque assembly in place, ro-
tate vane at constant speed of 1 deg/min and record maximum torque required.

Obtaining Remolded Strength—
    To obtain remolded strength, rotate vane at rate of one revolution in
10 seconds for minimum of 12 revolutions without taking readings.  Allow time
delay of 5 minutes and perform the previous again.

Obtaining Friction Resistance—
    Obtain friction resistance by proceeding as in steps Advancing Vane and
Recording Maximum Torque, using dummy rod without vane attached.  Make one de-
termination at each elevation for vane shear tests.

Identification Samples—
    After withdrawing vane from hole, remove and preserve a sample of the
sludge adhering to the vane for test of water content.

Interpretation of Test Data—
    Determine undrained shear strength by

                          6(T    - friction resistance)(lUU)
                 o      .     max
                  U                    2,
                   vane              irD  (3H + D,
                                      107

-------
where   T    = maximum torque in inch-pound as obtained in step Recording Max-
         max   .     m
               imum Torque



           H = vane height,  in.



           D = vane diameter, in.



      S      = undrained shear strength,  psf

        vane



Friction resistance is obtained in step Obtaining Friction Resistance above.



    Presentation of Data—Plot  S        versus depth.

                                  vane
                                      108

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K.  J     -•»•

 ,^^^L___— .1.   Mtfl
Figure B-l.   Determining the weight
of a sludge  specimen  submerged in
               water.
                        Figure B-2.  Evacuating air from samples
                        in determination of specific gravity.   A,
                         flask;  B,  splash trap; C, vacuum line.

-------
o

z
III
s-
Q,
U.
o

s-
I
   652
       S5
                              J:   I
20'
25
30
                        TEMPERATURE,  DEGREES CENTIGRADE



           Figure B-3'.-  T!ypic.al eali brat Ion  cmarre of wolTunmetric flask.
                                                 CONTEIMT-
\>, SO'LBD
1 SESMI6SOUO
j PLASTBC
SBMBLIQUBD ^
                     SHKINSKAGE

                        LMWPT
                                        OMPT
                        Figore  B— k.  Sltages  of cornsistenqy.
                                         110

-------
                                                                  NOTE ON DIMENSIONS:
                   GROOVING  TOOL
IMPORTANT NOTE FOR
CALIBRATION OF HEIGHT OF FALL:

haight of ctnt«r  of thmy contact tpol
(not of lowitt point) above ba*« is
IOmm • gog* height.
Grooving
Tool Gag*
                               CALIBRATION OF HEIGHT OF FALL
                     Figure  B-5-    Liquid  limit  device.
                                           Ill

-------
 -«> _

 rO  '•

    JL.__
                        2-^0.08—
             51
                         b!?
                            *
                               ^
                                     Drill  8~5Xe"

                                     Drill  and Tap
                                        1/4-20

                                     '/4-20 Allen
                                     Set  Screw
                              p
                              IB-T
                                                     DETAIL E
                                                       (SteeO
                                         8.3"'0.33"
              Rod=6~'A

              DETAIL  D
               (Brass)
                                                         Drill and Tap
                                                            10-24
           25^1"
Steel Pin-)-,
3~l/e"Dia
Drill  ond
Tap 4-40-


     3-/e"
           I3«i/fe|
                  KV
                  2
                  in
»
7
01
                               75°
                               V-
                             ''>*cr
                                           DETAIL F
                                             (Steel)
                                                                              2
                                                                              00
                                          Knurled-
                                            6v'/4"
                                            6-32
                                            Screw
                                     i/ ii  O
                                  l3v'/2  *
                                         ^
                                                                    DETAIL  G
                                                                     (Brat*)
                                                    Mil
                                                             Knurled
                                                                   "\
                                                          IO
                                                            CSI
                                           ^i
                                           ^
             DETAIL  H
               (Braes)
                                                DETAIL
                                                  (Bran)
                                                  DETAIL K
                                                    (B r a i s)
              0
              I
               INCHES
   NOTE  ON  DIMENSIONS:
   First  dimension given Is in  millimeters.
   ~meons  some tolerance is  permitted.
   • means  dimension  must be precise.
              Figure B-6.   Details  of  liquid  limit device.
                                        112

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Figure B-T-  Grooving liquid limit
            specimen.
    Figure B-8.   Closed liquid  limit
                 groove.
    Figure B-9.  Plastic limit
          d e termi nat ion.
Figure B-10.  Crumbling of threads at
           plastic limit.
                                     113

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                    1/8" DIAM
                               1/16" x 3" x 3" GLASS
                              15/16"           15/16"
                                 RADIUS = 0.54"
                                     15/16'
                              BRASS PINS SECURED
                                  WITH 3ALSAM
                     1/32" DIAM
                                           n
                                                1/32'
                                   1/8" [j     U    T
                                                           7/16"
                  WET SLUDGE'
                      PAT    :
                                    SHRINKAGE
                                      DISH
'DRY SLUDGE
     PAT    ;
              GLASS PLATE
                                                    EVAPORATING DISH.
TOP OF GLASS DISH
GROUND SURFACE
          MERCURY DISPLACED
          BY SLUDGE PAT
                                         DRY SLUDGE PAT
 Figure  B-ll.  Apparatus  for determining the volume of dry  sludge  pat of
                             shrinkage limit  test.
                                        llU

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                  	STANDPIPE AREA =(
                        NOTE: VALVE BETWEEN DEAIRED DISTILLED WATER
                             JUG AND CONSOLIDATION A P P A R A T U S SH OU L D
                             BE CLOSED DURING THE PERMEABILITY TEST.
               h   HEIGHT OF CAPILLARY RISE
                a
               a   INSIDE AREA OF STANDPIPE

               A   CROSS-SECTIONAL AREA OF SPECIMEN

               L   LEN GTH O F SPECIMEN

               h - H EIGHT OF WATER IN STANDPIPE
                °  AT TIME , tQ

               h,   HEIGHT OF WATER IN STANDPIPE
                   AT TIME, tf

               h( = HEIGHT OF TAILWATER


Figure B-12.   Typical consolidometer (fixed-ring  type) with
         falling-head device  for permeability test.
                               115

-------
J_"_
8

                                               -H   h-
JL"
16
       INSIDE  DIAMETER OF CONSOLIDATION RING - 0.005
                      SECTION  A-A
              Figure B-13.  Typical retainer ring
                            116

-------
H
-
-------
•t
I
o
13

Z

Q

<
Ld
tr
SLOPE 2 = J./5x SLOPE 7
              SLOPE 7

    d9Q = 90% COMPRESSION
                                     = TIME FOR 90% COMPRESSION
                              /TIME



    Figure B-15-  Square root of time-consolidation curve.
                              118

-------
   = HEIGHT OF
     CAPILLARY RISE
                          STANDPIPE AREA = CL
                                                  FL EX/ BL E
                                                   TUBE
                                           DE AIRED
                                       DISTILLED WATER
Figure B-l6.  Determination of height  of  capillary rise.
                            119

-------
0.6
  O.I
         0.5      1.0                  5.0
             PRESSURE p, TONS/SQ FT

Figure B-1T-   Void ratio-pressure curve.
10
                                                                    20
                                120

-------
                                SEE
                                TORQUE ASSEMBLY
D = 2 MIN.
                                    CASING FOR SUPPORT
                                    OF TORQUE ASSEMBLY.
                                    USE MINIMUM
                                    EMBEDMENT OF
                                    3- 1/2'.
                                 ROD TO CASING GUIDE
                                 BEARINGS. USE ONE
                                 IN UPPER 3- 1/2' AND
                                 ONE EVERY 30' IN
                                 CASED HOLES
                               VANE ROD
1 A
It






1



A '
t °
J ™
I
i
       Figure B-l8.   Vane shear  test equipment.
                            121

-------
        TABLE B-l.  RELATIVE DENSITY OF WATER AND CORRECTION FACTOR  K  FOR VARIOUS TEMPERATURES
Temperature
°C
18.0
18.1
18.2
18.3
18.U
18.5
18.6
18.7
18.8
18.9
19.0
19.1
19.2
19.3
19. U
19-5
19.6
19.7
19.8
19.9
20.0
20.1
20.2
20.3
20.U
20.5
20.6
20.7
20.8
20.9
21.0
21.1
21.2
21.3
21.1*
21.5
21.6
21.7
21.8
21.9
22.0
22.1
22.2
22.3
22.1*
22.5
22.6
22.7
22.8
22.9
Relative
Density*
0.99862
0.99860
0.99858
0.99856
0.99851*
0.99852
0.99850
0.9981*9
0.9981*7
0.9981*5
0.9981*3
0.9981*1
0.99839
0.99837
0.99835
0.99833
0.99831
0.99829
0.99827
0.99825
0.99823
0.99821
0.99819
0-99817
0.99815
0.99813
0.99810
0.99808
0.99806
0.99801*
0.99802
0.99800
0.99798
0.99796
0.99793
0.99791
0.99789
0.99787
0.99785
0.99783
0.99780
0.99778
0.99775
0.99773
0.99770
0.99768
0.99765
0.99763
0.99761
0.99758
Correction
Factor, Kt
l.OOOU
i.oooi*
l.OOOU
1.0003
1.0003
1.0003
1.0003
1.0003
1.0002
1.0002
1.0002
1.0002
1.0002
1.0001
1.0001
1.0001
1.0001
1.0001
1.0000
1.0000
1.0000
1.0000
1.0000
0.9999
0.9999
0.9999
0.9999
0.9998
0.9998
0.9998
0.9998
0.9998
0.9998
0.9997
0.9997
0.9997
0.9997
0.9996
0.9996
0.9996
0.9996
0.9996
0.9995
0.9995
0.9995
0.9995
0.9991*
0.9991*
0.9991*
0.9991*
Temperature
°C
23.0
23.1
23.2
23.3
23.1*
23.5
23.6
23.7
23.8
23.9
2l*.0
21*. 1
2l*.2
21*. 3
2l*.l*
2l*.5
21*. 6
21*. 7
2H. 8
21*. 9
25.0
25.1
25.2
25.3
25.1*
25.5
25.6
25.7
25.8
25.9
26.0
26.1
26.2
26.3
26.1*
26.5
26.6
26.7
26.8
26.9
27.0
27.1
27.2
27.3
27.1*
27.5
27.6
27-7
27.8
27.9
Relative
Density
0.99756
0.99751*
0.99751
0.997149
0.9971*6
0.9971*1*
0.9971*2
0.99739
0.99737
0.99731*
0.99732
0.99729
0.99727
0.9972!*
0.99722
0.99720
0.99717
0-99711*
0.99712
0.99709
0.99707
0.9970!*
0.99702
0.99699
0.99697
0.99691*
0.99691
0.99689
0.99687
0.9968!*
0.99681
0.99678
0.99676
0.99673
0.99670
0.99668
0.99665
0.99663
0.99660
0.99657
0.996^)!*
0.99651
0.9961*8
0.996^6
0.9961*3
0.9961*0
0.99637
0.9963!*
0.99632
0.99629
Correction
Factor, K
0.9993
0.9993
0.9993
0.9993
0.9992
0.9992
0.9992
0.9992
0.9991
0.9991
0.9991
0.9991
0.9990
0.9990
0.9990
0.9990
0.9989
0.9989
0.9989
0.9989
0.9988
0.9988
0.9988
0.9988
0.9987
0.9987
0.9987
0.9987
0.9986
0.9986
0.9986
0.9986
0.9985
0.9985
0.9985
0.998!*
0.998!*
0.998!*
0.998!*
0.9983
0.9983
0.9983
0.9982
0.9982
0.9982
0.9982
0.9981
0.9981
0.9981
0.9981
Temperature
°C
28.0
28.1
28.2
28.3
28.1*
28.5
28.6
28.7
28.8
28.9
29.0
29.1
29.2
29.3
29.!*
29-5
29.6
29.7
29.8
29-9
30.0
30.1
30.2
30.3
30.1*
30.5
30.6
30.7
30.8
30.9
31.0
31.1
31.2
31.3
31.1*
31.5
31.6
31.7
31.8
31.9
32.0
32.1
32.2
32.3
32.1*
32.5
32.6
32.7
32.8
32.9
Relative
Density
0.99626
0.99623
0.99620
0.99617
0.996l!*
0.99611
0.99608
0.99606
0.99603
0.99600
0.99597
0.99591*
0.99591
0.99588
0.99585
0.99582
0.99579
0.99576
0.99573
0.99570
0.99567
0.99561*
0.99561
0.99558
0.99555
0.99552
0.995!*9
0.995!*6
0.9951*3
0.9951*0
0.99537
0.99533
0.99530
0.99527
0.99521*
0.99521
0.99518
0.99515
0.99512
0.99509
0.99505
0.99502
0.99!*99
0.991*96
0.991*93
0.991*90
0.99!*86
0.99!*83
0.99!*8o
0.991*77
Correction
Factor, K
0.9980
0.9980
0.9980
0.9980
0.9979
0.9979
0.9979
0.9978
0.9978
0.9978
0.9977
0.9977
0.9977
0.9976
0.9976
0.9976
0.9976
0.9975
0.9975
0.9975
0.9971*
0.997!*
0.9971*
0.9973
0.9973
0.9973
0.9973
0.9972
0.9972
0.9972
0.9971
0.9971
0.9971
0.9970
0.9970
0.9970
0.9969
0.9969
0.9969
0.9969
0.9968
0.9968
0.9968
0.9967
0.9967
0.9967
0.9966
0.9966
0.9966
0.9965
*Relative density of water based on density of water  at  1*°C  equal  to  unity.   Data  obtained  from Smith-
 sonian Tables, compiled by various authors.
tCorrection factor  K  is found by dividing the relative density of water  at  the test  temperature by  the
 relative density of water at 20°C.
                                                 122

-------
   TABLE B-2.  CORRECTION FACTOR
RT
FOR VISCOSITY OF WATER AT VARIOUS TEMPERATURES
Temperature
°C
0.0
1.0
2.0
3.0
>+.0
5.0
6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
I**. 0
15.0
16.0
17.0
18.0
19.0
20.0
21.0
22.0
23.0
2k. 0.
25.0
26.0
27.0
28.0
29.0
30.0
31.0
32.0
33.0
3l+. 0
35.0
36.0
37.0
38.0
39.0
1+0.0
1+1.0
1+2.0
1+3.0
I+l+.O
1+5.0
1+6.0
1+7.0
1+8.0
1+9.0

0
1.783
1.723
l.66k
l.6ll
1.560
1.511
1.1*65
1.1+21
1.379
• 1.339
1.301
1.265
1.230
1.197
1.165
1.135
1.106
1.077
1.051
1.025
1.000
0.976
0.953
0.931
0.910
0.889
0.869
0.850
0.832
0.8ll+
0.797
0.780
0.76U
0.7^9
0.733
0.719
0.705
0.691
0.678
0.665
0.653
0.61+1
0.629
0.618
0.607
0.596
0.585
0.575
0.565
0.556

1
1.777
1.717
1.659
1.606
1.555
1.507
1.1+61
1.1+17
1.375
1.336
1.298
1.262
1.227
1.191+
1.162
1.132
1.103
1.075
l.Ql+8
1.022
0.998
0.97*+
0.951
0.929
0.908
0.887
0.867
0.81+8
0.830
0.812
0.795
0.778
0.763
0.71+7
0.732
0.718
0.70U
0.690
0.677
0.661;
0.652
0.639
0.628
0.6l6
0.606
0.595
0.581+
0.57!+
0.561+
0.555

2
1.771
1.711
1.651;
1.601
1.550
1.502
1.1+57
1.1+13
1.371
1-332
1.29U
1.258
1.223
1.190
1.159
1.129
1.100
1.072
l.Ql+5
1.020
0.995
0.972
0.9U9
0.927
0.906
0.885
0.866
0.81+7
0.828
0.810
0.793
0.777
0.761
0.71+6
0.731
0.716
0.702
0.689
0.675
0.663
0.650
0.638
0.627
0.615
o.6oi+
0.59>+
0.583
0.573
0.561+
0.551+

3
1.765
1.705
1.6U8
1.596
1.51+5
1.1+98
1.1+52
1.1+09
1.367
1.328
1.290
1.255
1.220
1.187
1.156
1.126
1.097
1.069
1.0^+3
1.017
0.993
0.969
0.91+7
0.925
0.901+
0.883
0.86U
0.81+5
0.826
0.809
0.792
0.775
0.759
O.lhk
0.729
0.715
0.701
0.687
0.671+
0.661
0.61+9
0.637
0.626
0.6lU
0.603
0.593
0.582
0.572
0.563
0.553
Tenths
1+
1.759
1.699
1.61+3
1.590
1.51+0
1.1+93
1.1+1+8
1.1+01+
1.363
1.321+
1.287
1.251
1.217
1.181+
1.153
1.123
1.091+
1.067
l.Ol+O
1.015
0.990
0.967
0.91+1+
0.923
0.901
0.881
0.862
0.81+3
0.825
0.807
0.790
0.77^
0.758
0.71+3
0.728
0.713
0.699
0.686
0.673
0.660
0.61+8
0.636
0.621+
0.613
0.602
0.592
0.581
0.571
0.562
0.552
of °C
5
1.753
1.69!+
1.638
1.585
1.535
1.1+88
1.1+1+3
1.1*00
1.359
1.320
1.283
1.21+8
1.213
1.181
1.150
1.120
1.091
1.061+
1.038
1.012
0.988
0.965
0.91+2
0.920
0.899
0.879
0.860
0.81+1
0.823
0.805
0.788
0.772
0.756
0.7!+!
0.726
0.712
0.698
0.685
0.672
0.659
0.61+7
0.635
0.623
0.612
0.601
0.591
0.580
0.570
0.561
0.551

6
1.7^7
1.688
1.632
1.580
1.531
1.1+81+
1.1+39
1.396
1.355
1.317
1.279
1.21+1+
1.210
1.178
1.1 Vf
1.117
1.089
I.o6l
1.035
1.010
0.986
0.962
0.9^0
0.918
0.897
0.877
0.858
0.839
0.821
0.801+
0.787
0.770
0.755
0.739
0.725
0.711
0.697
0.683
0.670
0.658
0.61+6
0.63!+
0.622
0.611
0.600
0.590
0.579
0.569
0.560
0.550

7
1.71+1
1.682
1.627
1.575
1.526
1.1+79
1.1+35
1.392
1.351
1.313
1.276
1.21+1
1.207
1.175
l.ll+U
1.111+
1.086
1.059
1.033
1.007
0.983
0.960
0.938
0.916
0.895
0.875
0.856
0.837
0.819
0.802
0.785
0.769
0.753
0.738
0.723
0.709
0.695
0.682
0.669
0.656
0.61+1+
0.632
0.621
0.610
0.599
0.588
0.578
0.568
0.559
0.5>+9

8
1.735
1.676
1.622
1.570
1.521
1.1+75
1.1+30
1.388
1.31+7
1.309
1.272
1.237
1.203
1.171
l.ll+l
1.111
1.083
1.056
1.030
1.005
0.981
0.958
0.936
0.911+
0.893
0.873
0.85!+
0.836
0.8l8
0.800
0.783
0.767
0.752
0.736
0.722
0.708
0.691+
o.68l
0.668
0.655
0.61+3
0.631
0.620
0.609
0.598
0.587
0.577
0.567
0.588
0.5>+8

9
1.729
1.670
1.616
1.565
1.516
1.1+70
1.1+26
1.383
1.31+3
1.305
1.269
1.23!*
1.200
1.168
1.138
1.108
1.080
1.053
1.027
1.002
0.979
0.955
0.933
0.912
0.891
0.871
0.852
0.83U
0.816
0.798
0.782
0.766
0.750
0.735
0.720
0.706
0.693
0.679
0.666
0.65U
0.61+2
0.630
0.619
0.6o8
0.597
0.586
0.576
0.566
0.557
o.s^a
Note:  Computed from Table 170, Smithsonian Physical Tables, 8th edition.
       Correction factor  RT  is found by dividing the viscosity of water  at the test
         temperature by the viscosity of vater at 20°C.
                                          123

-------
WATER CONTENT — GENERAL
DATE
PRO IF[~T


SAMPLE OR SPECIMEN NO.
TARE NO.
WEIGHT IN GRAMS
TARE PLUS WET SLUDGE
TARE PLUS DRY SLUDGE
WATER
ww
TARE
DRY SOLIDS
WATER CONTENT
SOLIDS CONTENT
*S
w
S
SAMPLE OR SPECIMEN NO.
TARE NO.
WEIGHT IN GRAMS
TARE PLUS WET SLUDGE
TARE PLUS DRY SLUDGE
WATER
Ww
TARE
DRY SOLIDS
WATER CONTENT
SOLIDS CONTENT
«s
w
S
SAMPLE OR SPECIMEN NO.
TARE NO.
WEIGHT IN GRAMS
TARE PLUS WET SLUDGE
TARE PLUS DRY SLUDGE
WATER
TARE
DRY SOLIDS
WATER CONTENT
SOLIDS CONTENT
W7.
S%
RE*.
ww

*s
w
S







7o
7,







%
7.







%
%







%
%







1.
%







7,
%







7.
7.







1
%







%
7.
(TARE PLUS WET SLUDGEl - (TARE PLUS DRY SLUDGE) Ww
(TARE PLUS DRY SLUDGE) — (TARE) Ws
Ws 100
(TARE PLUS WET SLUDGE) — (TARE) ' w
Too '
«ARKS







°>,
%







7o
7.







%
1,
- X 100. OR









7U
7o







%
%







7,
7,








"•
%







7.
%







70
7,
f\00 \
\ s /

COMPUTED BY CHECKED BY


PLATE B-l

-------
UNIT WEIGHTS
(VOLUMETRIC METHOD)
PROJECT

DATF


WATER CONTENT
SAMPLE OR SPECIMEN NO.
TARE
in
WEIGHT IN GRAN
NO.
TARE PLUS WET SLUDGE
TARE PLUS DRY SLUDGE
WATER
Ww
TARE
DRY SLUDGE
WATER CONTENT
SOLI DS CONTENT
ws
w
S







7o








<",
-"7
















-

WEIGHT-VOLUME RELATIONS
SAMPLE OR SPECIMEN NO.
VOLUMETRIC CONTAINER NO.
CENTI-
METERS
N GRAMS
WEIGHT 1
VOLUME
IN CC
:t
5s
VOLU
t 1 F N
MAY
SPE
REMA
COMP
HEIGHT OF CONTAINER
INSIDE DIAMETER OF CONTAINER
H
D
WET SLUDGE AND TARE
TARE
WET SLUDGE
DRY SLUDGEt
WET SLUDGE (VOLUME OF CYLINDER)

WET UNIT WT - (W/V) 62.4
DRY UNIT WT = (Ws / V) 62. 4
7TD2H
VIE O F CYLIN DER V 	 VOLUME
4
OT MEASURED ON ENTIRE SPECIMEN. DR
W
W
Ws
V

ym
yA












: OF WATER. vw
r WEIGHT
i
5 1 + 0.01 w
CIFIC GRAVITY OF WATER IN METRIC SYSTEM
RKS




































Ww
SPECIFIC GRAVITY OF WATERt
= 1 (APPROX)
UTED BY ruFCKFD BY
                         PLATE B-2
125

-------
UNIT WEIGHTS
(DISPLACEMENT METHOD)
PROJECT

DATE


WATER CONTENT
SAMPLE OR SPECIMEN NO.
TARE NO.
WEIGHT IN GRAMS
TARE PLUS WET SLUDGE
TARE PLUS DRY SLUDGE
WATER
TARE
DRY SLUDGE
WATER CONTENT
SOLIDS CONTENT
Ww

«s
w
S







%
%







°7
%







%
%








%
%
WEIGHT-VOLUME RELATIONS
SAMPLE OR SPECIMEN NO.
TEST TEMPERATURE OF WATER. T, C
WEIGHT IN GRAMS
VOLUME IN CC
st
52
VOLU
t I F N
\ VOL
REMA
COMP
SLUDGE AND WAX IN AIR
WET SLUDGE
W
WAX
WET SLUDGE AND WAX IN WATER
DRY SLUDGEt
ws
WET SLUDGE AND WAXt
WAX
WET SLUDGE
DRY SLUDGE = WS/GS
WET UNIT WT - (W/V) 62.4
DRY UNIT WT = (WS/V) 62.4
V
vs
ym
?i
WEIGHT OF WAX
SPECIFIC GRAVITY OF WAX




























DT MEASURED DIRECTLY. MAY BE COMPUTED AS FOLLO
/WEIGHT OF WET SLUDG
UME OP WET -LUDCC AND «AX -> AN° WAX 'N A'R














W














ws. ws - , +0 01 w
E\_f WEIGHT OF WET SLUDGE\
/ \ AND WAX IN WATER )
DENSITY OF WATER AT TEST TEMPERATURE
RKS
JTED BY CHFCKED BY
PLATE B-3
                                 126

-------
SPECIFIC GRAVITY TESTS
DATE
PROJECT



SPECIFIC GRAVITY OF SOLIDS. Gs
SAMPLE OR SPECIMEN NO.
F LASK NO.
TEMPERATURE OF WATER AND SLUDGE, T. °C
DISH NO.
WEIGHT IN GRAMS
DISH t DRY SLUDGE
DISH
DRY SLUDGE
FLASK » WATER AT T, "C
ws
«bw
ws • wbw
FLASK WATER * IMMERSED SLUDGE
DISPLACED WATER, Ws + Wbw Wbws
CORRECTION FACTOR
(WSKI •=- (Ws + Wbw - Wbws)
w bws

K
GS




















































REMA RKS


COMPUTED RY CHECKED BY


                             PLATE B-U
127

-------
LIQUID AND PLASTIC LIMIT TESTS
DATE
PROJ


SAMPIf M"
LIQUID LIMIT
RUN NO
TARE NO.
WEIGHT 1
IN GRAMS


TARE PLUS WET SLUDGE
TARE PLUS DRY SLUDGE
WATER W
TARE
DRY SLUDGE W S
WATER CONTENT W
NUMBER OF BLOWS

1








2








3


















	



5

^




t^

f






















	







































































































































































































4












































S 10 20 30 40
NUMBER OF BLOWS
5








6








LL
PL
PI

PLASTIC LIMIT
RUN NO

WEIGHT
IN GRAMS
TARE NO
TARE PLUS WET SLUDGE
TARE PLUS DRY SLUDGE
WATER W w
TARE
DRY SLUDGE S
WATER CONTENT *
PLASTIC LIMIT
1








2








3








4








5








NATURAL
WATER
CONTENT








BFMARKS






CHECKED 8V


PLATE B-5
                                   128

-------
SHRINKAGE LIMIT TEST
PROJECT


DATE


SAMPLE OR SPECIMEN NO.
SHRINKAGE DISH NO.
N GRAMS
H
I
0
UJ
t
VOLUME IN CC
DISH PLUS WET SLUDGE
DISH PLUS DRY SLUDGE
WATER
SHRINKAGE DISH
DRY SLUDGE
DISPLACED MERCURY + EVAPORATING DISH

w
** w

*s

EVAPORATING DISH
DISPLACED MERCURY
SHRINKAGE DISH (WET SLUDGE PAT)
VOLUME OF DRY SLUDGE
V _ Vs
V - Vs
*s
Ww
WATER CONTENT = -^ X 100
ws
SHRINKAGE LIMIT
SHRINKAGE RATIO
Vs =
SL =
\
WEIGHT OF DISPLACED MERCURY

V
vs


w
SL
R














X
















%



SPECIFIC GRAVITY OF MERCURY (13.53 g/cc
WATER CONTENT OF WET SLUDGE PAT
^VOLUME OF WET SLUDGE PAT- VOLUME OF OVEN-DRY SLUDGE PAT\
\ WEIGHT OF OVEN-DRY SLUDGE PAT )
WEIGHT OF OVEN-DRY SLUDGE PAT Ws














1«
















1.


/V - V5 \
(— X 10°)
VOLUME OF OVEN-DRY SLUDGE PAT Vs
REMARKS




COMPUTED BY


r.MECKED BY



                         PLATE B-6
129

-------
                                       CONSOLIDATION TEST


                                        (Specimen Deta)
                                                                      Date .
   Project.
                                                  Sample No.
   Classification
                                           Before Test
                                                                               After Test
                                 Specimen
                                                    Extra material
                                                                                Specimen
  Tare  No.
                              Ring and plates
      Tare  plus wet  sludge
      Tare  plus  dry  sludge
        Water
                      W
                                                                          wf
      Tare
        Dry soil
                                                                          8f
        Water content  w
  Consolldometer No.
                                                  Area of specimen,  A,  sq cm
  Weight  of  ring, g
Height of specimen,  H,  in.
  Weight  of plates, g
Sp gr of solids,  G8
  Height  of  solids, Hs = A x 0.  x y
                                                           x 1 x 2.
                               in.
  Original height of water, H   = .
                            WO   A X 7
  X 1 X 2. 54
                        in.
  Final height of water,
                                                 x 1 x 2.5U
                     in.
 Net  change in height of specimen at end of test, AH


 Height of specimen at end of test, H. = H - AH

                              H - H  r
                            in.
                       in.
 Void ratio before test, e  =
 Void ratio after test, ef
                             Hf -Hs
                                         H

 Degree of saturation before test, S    =	=-
                                    O   n •• u
                                             6

                                         H

 Degree of saturation after test, S. = =	=-

                                   f   Hf ' He
 Dry density before test, 7
                                                              62.4
                           d   H X A
                            Ib/cu ft
 Remarks
                                  Computed by
               _Checked by
PLATE B-1
                                               130

-------

FALLING-HEAD PERMEABILITY TEST
PROJECT

WITH CONSOLIDOMETER

j
DATE



SAMPLE OR SPECIMEN NO.
WT IN GRAMS
TARE PLUS DRY SLUDGE
TARE
DRY SOLIDS W$
SPECIFIC GRAVITY Gj
VOL OF SOLIDS. CC = W + G V
AREA
OF STANDPIPE, SO CM •
CAPILLARY RISE. CM h(
HEIGHT OF TAILWATER. CM h.
TEST NO.
LOAD
DIAL
INCREMENT. T/SO FT
READING AT START, IN.
CHANGE IN HT OF SPEC. IN. » D - D.
0 1
HT OF SPEC, CM = L - 2.M AD
VOID
RATIO « (AL - v§) + vt
P
D,
Ao
L
.


INITU

kL TIME
FINAL TIME
ELAPSED TIME. SIC ='(-'„
INITIAL HEIGHT. CM
FINAL HEIGHT, CM
WATER TEMPERATURE. "C
VISCOSITY CORRECTION FACTOR

121
CM/SEC

(1t CORRECTION FACTOR FOR VISCOSITY 0
111 i 0 L ^i ~ Ak r
REMARKS



t.
'l
1
k,
h,
T
R T
k»
AVG
F WAT
LOG
DIAMETER OF SPECIMEN, CM
AREA OF SPECIMEN. SO CM
INITIAL HEIGHT OF SPECIMEN. CM
INITIAL VOL OF SPEC, CC * AL
INITIAL VOID RATIO = (V - Vf) * V,

INITIAL DIAL READING, IN.
CORRECTED TAILWATEH. CM, h, + hc
1





10









-------
CONSOLIDATION TEST
(TIME-CONSOLIDATION DATA!
PROJECT
SAMPLE NC
DATE AND
PRESSURE




































3.

TIME




































ELAPSED
TIME. MIN




































DIAL RDG.
10-4 IN.





































TEMP
•c




































DATE

CONSOL. NO.

DATE AND
PRESSURE





































TIME





































ELAPSED
TIME, MIN





































DIAL RDG.
10-" IN.





































TEMP
•c




































CONDUCTED BY


PLATE B-C
                                  132

-------
DEFORMATION IN 10"1 INCHES
0 o
1 0.2 0.5








































































































































































TIME IN MINUTES
12 5 10 20 50 100 200 500 1000 2000










































NOTE: NUMBERS ftESIDE CURVES











































ARE PRESSURES IN T/SQ FT.

















































































































"" 1 "



r






















i































.._

















































































































" !






1

















+~ ~^













I










i





























—






































































































































j_
i j '



[




!







|
i
1









J_









\









i
































102 0.5 1 2 5 10 20 50 100 200 500 1000 2000
TIME IN MINUTES
PKOJECT
AREA
SAMPLE NO.
DATE
CONSOLIDATION TEST-TIME CURVES
                        PLATE B-10
133

-------
       £
       1-3
       td
U)
f

2
DC
o
li.
UJ
Q
             NOTE: NUMBERS BESIDE CURVES

                  ARE PRESSURES IN  T/SQ FT
                  10
                                 100
                                                             500
                                                                                 1000
                                                                                                               2000
                                  Dial reading versus time-data  for each load increment

-------
OJ
           td
           I
CONSOLIDATION TEST
(COMPUTATION OF VOID RATIOS)
DATE
PROJECT

SAMPLE NO. CONSOLIDOMETER NO.

PRESSURE, f
T/SQ FT

















DATE
INCREMENT
APPLIED

















HEIGHT OF VOIDS. MV = |H - HS) -
H v
VOID RATIO. C = 	
H ,
CONDUCTED BY
TIME IN MIN
INCREMENT
EFFECTIVE

















DIAL READING
10-* IN.

















H =
COMPUTED BY
CHANGE IN
HEIGHT, AH
10-4 IN.

















HEIGHT OF
VOIDS. Hv
10-* IN.

















VOID RATIO, e

















COEFFICIENT OF
CONSOLIDATION
Cv, 10~* IN.2/SEC

















COEFFICIENT OF
SECONDARY
COMPRESSION
Co, 10-3/MIN

















CHECKED BY


-------
0
0)
0
-H
-p
a)
K
T)
T-t
§
0
Coefficient of Permeability, kg0, 10" cm/sec
1 0.2 0.3 OAO-5 1 23^5 10 20 25


























































































































































































































































































































































































































































































































































































































































































1 0.2 0.3 O.UO-5 1 23^5 10 20 25
Pressure, p, T/aq ft
Type of Specimen
Diam in.
Ht in.
Compression Index, Cc
Classification
LL
PL
G

Remarks





Before Test
Water Content, w
Void Ratio, e
Saturation, S
Dry Density, 7^
*

%
lb/ft3
After Test
Wf
ef
Sf

*

*

k2Q at CQ x 10" cm/sec
Project

Area
Sample No.
Date
CONSOLIDATION TEST REPORT
PLATE B-13
                                 136

-------
                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
  REPORT NO.
   EPA-600/3-76-111
                              2.
                                                           3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTm P
   DESIGN CONSIDERATIONS FOR PULP AND PAPER-MILL
   SLUDGE LANDFILLS
                                                           5. REPORT DATE
                                                             December 1976  (Issuing  Date)
                                                           6. PERFORMING ORGANIZATION CODE
 7. AUTHOR(S)
   Richard H.
             Ledbetter
                                                           8. PERFORMING ORGANIZATION REPORT NO
 9. PERFORMING ORG "VNIZATION NAME AND ADDRESS
   Soils and Pavements  Laboratory
   U.S.  Army Engineer Waterways Experiment Station
   P.O.  Box 631, Vicksburg,  Mississippi  39180
                                                           10. PROGRAM ELEMENT NO.
                                                            1DB064  (SOS#3 Task  05)
                                                           11. CONTRACT/GRANT NO.
                                                             EPA-IAG-D5-F657
 12. SPONSORING AGENCY NAME AND ADDRESS
   Municipal Environmental  Research Laboratory - Cin.,  OH
   Office of Research  and  Development
   U.S.  Environmental  Protection Agency
   Cincinnati, Ohio  45268
                                                           13. TYPE OF REPORT AND PERIOD COVERED
                                                            Final  Jan. '75-Jan.  '76
                                                           14. SPONSORING AGENCY CODE
                                                            EPA/600/14
 15. SUPPLEMENTARY NOTES
   Robert E. Landreth
   513/684-7871
                      - Project Officer
 16. ABSTRACT
        This  report presents procedures  for  the engineering design and control  of
    pulp and  paper-mill  sludge disposal  landfills.   Engineering design will allow
    more efficient use,  thereby contributing  to economic and environmental benefits.
    To form the  basis for engineering design  of sludge  material, the methodologies
    and theories of soil  mechanics were  applied.  The methodologies should be ap-
    plicable  to  most compositions of sludge materials.   Some sludge materials may
    have peculiarities associated with testing,  field workability, and behavior.
    However,  from accumulated experiences of  applying the procedures of this
    manual, the  manual can be adjusted and expanded.
        This  report is specifically written for pulp and paper-mill personnel of
    technical background  but with little or no  exposure to the soil mechanics dis-
    cipline.  The procedures are such that these individuals can rationally approach
    a landfill operation  to attain efficiency and optimization.  This  report does
    not present  a rigorous treatment or  analysis of  sludge material, but it does
    give the  above-mentioned individuals the  procedures for determining good approx-
    imations  of  sludge behavior.  Individuals interested in more rigorous and theo-
    retical analysis of sludge behavior  should  consult  the list of references.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                             b.IDENTIFIERS/OPEN ENDED TERMS  C. COSATI Field/Group
    waste disposal
    sludge disposal
    soils
    paper mi 1 Is
    soil  mechanics
                                              solid waste  management
                                              sludge  landfill
                                              landfill
   13B
 S. DISTRIBUTION STATEMENT

 RELEASE TO PUBLIC
                                             19. SECURITY CLASS (This Report)
                                              UNCLASSIFIED
21. NO. OF PAGES
   151
                                              20. SECURITY CLASS (This page)
                                                 :LASSIFTFH
                                                                        22. PRICE
EPA Form 2220-1 (9-73)
                                            137
                                                                    •4U.S. GOVERNMENT PRINTING OFFICE. 1977- 757-056/5467

-------