United States
               Environmental Protection
               Agency
Permits Division .
Washington, DC 204SO
August 1989
               Water
3EFK
               POTW Sludge Sampling and
               Analysis Guidance Document
                                               Printed on Recycled Paper

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                            DISCLAIMER

     This document has been reviewed by the Environmental
Protection Agency and approved for distribution in order to
provide guidance on the sampling and analysis of municipal sewage
sludge.  EPA assumes no responsibility for use of this
information in a particular situation.   Mention of trade names or
commercial products does not constitute endorsement or
recommendation for use.
                                11

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                        TABLE OF CONTENTS

                                                            Page

ACKNOWLEDGEMENTS	u• *•	 vi

1.   INTRODUCTION	 1-1

2 .   SLUDGE SAMPLING	 2-1

     2 .1  BACKGROUND INFORMATION	 2-1

          2.1.1  Solids Content and Viscosity	 2-1
          2il.2  Processed Sludge Characteristics	 2-2
                                         •
                 2.1.2.1  Anaerobically Digested Sludge	 2-2
                 2.1.2.2  Aerobically Digested Sludge..	 2-3
                 2.1.2.3  Dewatered Sludges	 2-3
                 2.1.2.4  Compost Product	 2-3
                 2.1.2.5  Dried Powder	 2-3

     2.2  SAMPLE POINT SELECTION	 2-4

          2.2.1  General Considerations...-	 2-4

                 2.2.1.1  Sample Point Representation of
                          the Entire Sludge Stream	 2-4
                 2.2.1.2  Availability of Flow Data and/or
                          Solids Data	 2-7

          2.2.2  Sludge Sample Points	 2-8

     2.3  SAMPLE COLLECTION	 2-8

          2.3.1  Sampling Equipment	 2-11
          2.3.2  Proper Sampling Practices	 2-12

     2.4  SAMPLE SIZE, SAMPLE TYPE, AND SAMPLING FREQUENCY.. 2-14

     2 .5  SAMPLE PREPARATION AND PRESERVATION	 2-19

          2.5.1  Sample Container Material	 2-20
          2.5.2  Sample Container Preparation	 2-20
          2.5.3  Sample Preservation	 2-21
          2.5.4  Holding Time Prior to Analysis	 2-22

2 . 6  PACKAGING AND SHIPPING	 2-22

          2.6.1  Packaging	 2-22
          2.6.2  Transportation Regulations	 2-22
                               111

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                  TABLE  OF CONTENTS   (Continued)

                                                             Page

     2.7  DOCUMENTATION	 2-24

          2.7.1  Sample Labeling	 2-24
          2.7.2  Chain-of-Custody	 2-26
          2.7.3  Sampling Log Book	 2-27

     2 . 8  SAFETY CONSIDERATIONS	 2-27

3 .    ANALYTICAL PROCEDURES	 3-1

     3.1  CONVENTIONAL AND INORGANIC POLLUTANT PARAMETERS... 3-2
     3.2  METALS	•	 3-6

          3.2.1  Analyte Isolation/Preparation Overview	 3-6
          3.2.2  Analytical Techniques for Metals	 3-8

                 3.2.2.1  Sample Preparation/Digestion	 3-8
                 3.2.2.2  Analytical Detection Methods	 3-9

     3.3  ORGANICS	 3-18

          3.3.1  Overview of Analyte Extraction and
                 Isolation.	 . 3-18
          3.3.2  Recommended Analytical Techniques for
                 Organics	 3-22

                 3.3.2.1  Methods 1624C and 1625C	 3-23
                 3.3.2.2  Methods 624-S and 625-S	 3-25

     3 . 4  PATHOGENIC MICROORGANISMS	 3-26

4 .    QUALITY ASSURANCE	 4-1

5.    SAMPLING AND ANALYTICAL COSTS	*	 5-1

     5.1  MANPOWER REQUIREMENTS	 5-1
     5. 2  IN-HOUSE ANALYTICAL COSTS	 5-2
     5. 3  CONTRACT ANALYTICAL COSTS.	 5-4
     5. 4  SAMPLING EQUIPMENT COSTS		 5-4
     5.5  Opportunities for Cost Savings	 5-7

6.    REFERENCES	 6-1

A.    APPENDIX A: Chain of Custody Form	 A-l

B.    APPENDIX B: Determination of Volatile Solids Reduction. B-l
                                IV

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                          LIST  OF  TABLES


Table                               .                        Page

2 .1  Sludge Flow Measurement Devices	 2-9

2.2  Sludge Sampling Points	 2-9

2.3  Containers, Preservation,  Holding Times, and Minimum
     Sample Volume	 2-15

2.4  Potential Interferences Associated with Sampling
    . Shipping and Storage	 2-23

2.5  Standard Preservatives Listed in the Hazardous
     Materials Table (49 CFR 172.101)  Used by EPA for
     Preservation of Water, Effluent,  Biological, Sediment
     and Sludge Samples	 2-25

3.1  Analytical Techniques for Conventional and Inorganic
     Pollutants in Sludge	 3-3

3.2  Recommended Preparation Technique for Elemental
     Analysis of Sludge Samples	•.. 3-10

3.3  Comparison Summary of ICAP and AAS.	 3-12

3 .-4  Recommended Inductively Coupled Wavelengths and
     Estimated Instrumental Detection Limits	 3-14

3.5  Atomic Absorption Flame and Furnace Instrumental
     Detection Limits for Wastewater Samples	 3-16

3.6  Analytical Techniques for Determination of Pathogenic
     Microorganisms in Sewage Sludge	 3-29

5.1  Sampling Manpower Needs.	 5-2

5.2  Typical Contract Analytical Costs for Commonly
     Analyzed Sludge Parameters	 5-5

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                         ACKNOWLEDGMENTS

     This guidance  document was authored  by  Cristina (Morrison)
Gaines, of the U.S. EPA's Office of Water Enforcement and Permits
(OWEP), with  assistance from  Tom Wall, also  of OWEP.   Science
Applications  International  Corporation   (SAIC)   prepared  this
document  under  EPA Contract  No.  68-01-7043.   The SAIC  Work
Assignment Manager was Werner H. Zieger.  Significant contributions
were made by Jorge McPherson, John .Sunda,  and Mark Klingenstein.

     The document was revised to address peer review comments under
EPA  Contract  No.  68-C8-0066.    EPA  wishes  to acknowledge  the
valuable  peer  review  and  comments  provided  by  the  following
entities:

     o    EPA Region 3
     o    EPA Region 5
     o    EPA Region 9
     o    EPA Region 10
     o    EPA Environmental Monitoring Support Laboratory
     o    AMSA
     o    California State Water Resources Control Board
     o    Connecticut Department of Environmental Protection
     o    Eli Lilly and Company
     o    Eugene Oregon Public  Works Department
     o    LA County Sanitation  District
     o    Missouri Department of Natural Resources
     o    Nampa, Idaho Wastewater Division
     o    Ohio EPA
     o    Unified Sewerage Agency of Washington County
     o    John  F.  Morrison,  P.E.,  Past   President  of  American
               Society of Quality Control  Engineers
                               VI

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                         1.   INTRODUCTION

     The passage of the 1987 amendments to the Clean Water Act
brought about significant changes in the regulation of the use
and disposal of municipal sewage sludge.  Although the Clean
Water Act had required since 1977 that EPA develop technical
standards for sludge use and disposal, the 1987 amendments
required that these standards, when promulgated, be implemented
through permits.  The amendments also state that prior to
promulgation of the technical standards, EPA must include sludge
conditions in NPDES permits issued to publicly-owned treatment
works or take other appropriate measures to protect public health
and the environment from pollutants in sewage sludge.  This
requirement has initiated a program for "case-by-case11 permitting
to ensure protection of the environment prior to the issuance of
final sludge standards which are scheduled for promulgation in
October 1991.

     This focus on sludge permitting places increased emphasis on
the heed to assess sewage sludge quality.   In policy and guidance
documents that EPA has developed for implementing the sludge
requirements of the Clean Water Act, the Agency has recommended
that POTWs sample and analyze their sludge at least annually to
determine if the sludge quality is such that the sludge may be
safely reused and recycled or disposed.  Accurate character-
ization of sludge composition spots operational problems at the
treatment works and may also signal adverse environmental
impacts.  In addition, sludge sample and analysis is needed to
assess compliance with current requirements (e.g., 40 CFR Part
257 requirements for cadmium and PCBs).
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     In view of the variability of municipal sludge quality,
appropriate procedures must be followed to collect and analyze
samples .that accurately represent each POTW's sludge quality.
This manual was developed to provide that guidance to POTW
operators, engineers, managers, chemists and permit writers.  It
was intended to provide guidance in developing and implementing a
sampling and analysis program, to gather information on sludge
quality and determine compliance with permit conditions.  This
manual is based on current, state-of-the-art field and laboratory
practices and therefore is .recommended for all sludge sampling
and analysis programs.
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                       2.  SLUDGE SAMPLING

2.1  BACKGROUND INFORMATION
     Depending on the use or disposal practice, it may be
necessary to sample various sludge types throughout a given POTW.
In order to sample a sludge stream effectively, it is necessary
for sampling personnel to be aware of the physical
characteristics of the sludge stream(s) at intended sampling
locations.

2.1.1  Solids Content and Viscosity
     Two important physical characteristics of sludge with
respect to sampling and analysis are viscosity and solids
content.  Solids content is the percent, by weight, of solid
material in a given volume of sludge.  Sludges have a much higher
solids content than most wastewaters.  Solids content and solids
settling characteristics determine whether a given sludge will
separate into different fractions which increases the potential
of obtaining a nonrepresentative sample.

     Viscosity is the degree to which a fluid resists flow under
an applied force.  The viscosity of a sludge is only somewhat
proportional to solids content.  This property affects the
ability to automatically sample a liquid, since friction through
pipes is proportional to liquid viscosity.  In general, sludges
of up to 20 percent solids may be conveyed by means of a pump.
Sludge with a greater solids content, often referred to as sludge
cake, must be conveyed by mechanical means.  Automatic samplers
that rely on pumps may be useful only for liquid sludges with a
solids content of less than 20 percent.  However, sludge cakes
require manual grab sampling.  Other problems created by sludge
                          2-1

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solids (see Section 2.3.1) generally preclude the use of auto-
matic samplers.

     Solids content is also significant from an analytical stand-
point.  Increased solids content may require sample dilution and
cause a corresponding increase in experimental error and
detection limits.  Also, water removal through dewatering can
either concentrate parameters of interest in the sludge and
increase analytical accuracy, or carry away pollutants and
decrease pollutant concentration and analytical accuracy.
Analytical precision (repeatability) and accuracy (closeness to
true value) may also decrease as the concentration of interfering
compounds and matrix effects increase, due to higher solids
content after dewatering.

2.1.2  Processed Sludge Characteristics
     The quantity and quality of sludge generated depends on raw
wastewater characteristics and the sludge treatment practices.
The sludge to be sampled may be in the form of a liquid,
dewatered cake, compost product, or dried powder.  Some of the
physical characteristics of each sludge type are described below.

2.1.2.1  Anaerobically Digested Sludge
     Anaerobically digested sludge is a thick slurry of
dark-colored particles and entrained gases.  When well digested,
it dewaters easily and has a non-offensive odor.  The addition of
chemicals coagulates a digested sludge prior to mechanical
dewatering.  The dry residue of digested sludge contains 30 to 60
percent volatile solids.  Depending on the mode of digester
operation, the percent solids of digested sludges ranges from 4
to 8 percent.
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2.1.2.2  Aerobically Digested Sludge
     Aerobically digested sludge is a dark-brown, flocculent,
relatively inert waste produced by long-term aeration of sludge.
The suspension is bulky and generally difficult to thicken.   The
odor of aerobically digested sludge is not offensive.  The
percent solids of aerobically digested sludge is less than that
of the influent sludge (if not decanted), because approximately
50 percent of the volatile solids are converted to gaseous end
products during aerobic digestion.

2.1.2.3  Dewatered Sludges
     Dewatering converts sludge from a flowing mixture of liquids
and solids to a cake-like substance more readily handled as a
solid.  The characteristics of dewatered sludge depend on the
type of sludge, -chemical conditioning, and treatment processes
employed.  The percent solids content of dewatered cake ranges
from 15 to >40 percent.  Cake with a lower percent solids is
similar to a wet manure, while cake with a higher percent solids
is a chunky solid.

2.1.2.4  Compost Product
     Composting is a process in which organic material undergoes
biological degradation to a stable end product.  Properly
composted sludge is a sanitary, nuisance-free, humus-like
material containing 75 to 80 percent solids.  Approximately 20 to
30 percent of the volatile solids are converted to carbon dioxide
and water.

2.1.2.5  Dried Powder
     Dried powder is the residue from heat drying processes.
Sludge drying reduces water content by vaporization of water to
permit sludge grinding, weight reduction, and to prevent
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continued biological action.  The moisture content of dried
sludge is less than 10 percent.

     Incinerator ash is a product of the incineration of sewage
sludge.  Ash is therefore not covered under the sampling or
analysis of sewage sludge.  It is covered under RCRA Subtitle C
if it is a hazardous waste and if not it falls under Subtitle D.

2.2  SAMPLE POINT SELECTION

2.2.1  General Considerations
     NPDES, pretreatment and sludge program officials need sludge
quality data in order to determine whether sludge use or disposal
may pose a threat to public health or the environment.  Thus, as
a general rule, sludge samples should be drawn from an
appropriate sampling point and in such a manner that the sample
represents, as well as possible, the quality of the sludge as it
will be disposed of or used.  When selecting a specific sample
point, the following two factors should be carefully considered:

     o    Does the sample point represent the entire sludge
          stream?
     o    Are the sludge stream flow or mass flux data available?

The following paragraphs examine both factors and present
recommendations on means to address each factor.

2.2.1.1  Sample Point Representation of the Entire Sludge Stream
     Often It is not possible to.obtain a wholly representative
sample of a given wastestream at any one time.  Effort must be
made, however, to ensure that a sample is obtained that is as
representative as possible.  Three concerns that need to be
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addressed to ensure that the sample points selected will provide
representative samples of the entire sludge stream are:
obtaining samples that are representative of the cross-section of
the entire flow; obtaining well mixed samples; and obtaining
samples of multiple sludge streams.

     A particular concern in any sampling program is to obtain
samples which represent the entire flow past the sample point
throughout the sample period.  Each discrete sample should
represent the cross-section of the entire flow at the sampling
point.  Each composite sample of multiple contributory streams
should represent the cross-section of the entire flow'of the
combined stream.

     Samples should be obtained from points where the sludge is
well-mixed.  While some pollutant parameters are predominantly
associated with the solids fraction (particularly precipitated
metals), others are more associated with the liquid-fraction
(many dissolved organics).  Failure to acquire a sample with
representative solid/liquid fractions can significantly affect
the analytical results of a given sample.  This is particularly
true of sludge streams with high percent solids and large floe
particles.  Since turbulence ensures mixed samples, these
recommendations should be followed:
          In sludge processing trains, samples from taps on the
          discharge side of sludge pumps are well mixed since
          flow at this point in the system is turbulent with no
          solids separation within'the flow stream.
          If a sample is drawn from a tap on a pipe containing
          sludge which is distant from the sludge pumps, the
          average flow velocity through the pipe should be
          greater than 2 feet per second (fps).  Average
          velocities of less than 2 fps result in solids
          separation and settling, and affect sample solids
          content, depending on the location of the tap (top,
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          side or bottom of the pipe).   Given a choice,  a tap on
          the side of the pipe is preferable.  In addition,  the
          tap should be a large size to encourage draw from the
          entire cross-section of flow when fully open.

     At times it may be necessary to sample a poorly mixed open
channel flow.  If this cannot be avoided, then each sample must
be a composite consisting of grabs taken at several levels (1/4,
1/2 and 3/4 depth, for example) in order to minimize sample bias
caused by solids stratification.  For sampling solid sludges
(i.e. dewatered cake, compost, etc.), stratification can be
avoided by not only sampling at various depths, but at numerous
locations over the entire sludge pile.

     Although it is preferable to sample sludge just prior to its
exit from the treatment plant in a combined stream, sometimes
that is not possible.  Therefore, a consideration in many sludge
sampling situations is the need to produce a composite sample
from confluent streams.  An example is the sampling of sludge
flows from several parallel sources which later combine
downstream in an unsafe or inaccessible location. . Several
options exist to accommodate multiple streams.  The most
appropriate choice depends on the sludge flow and solids flux
information available, the parameters being sampled and the
purpose of the generated data.  Several options are as follows:

     o    The simplest option is to withdraw equal volumes of
          sample from each of the multiple sludge streams to
          create a composite sample.  This approach is justified
          in the case of identical units receiving equal flow and
          generating equal sludge amounts.
     o    A second option is to weight the grab samples in each
          composite according to the wastewater flow to each unit
          (or in the case of filter cake, the thickened sludge
          flow to each unit).  This approach recognizes that for
          different sized units with different design flows, the
          volume of sludge produced will theoretically be
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          proportional to the influent flow to the unit.
          However,  factors such as unequal loading rates,
          differences in sludge collection mechanisms, etc.  can
          affect solids removal rates and sludge generation rates
          by unequal, parallel treatment units.  This option
          particularly applies to situations where no sludge flow
          or solids data exists for unequal parallel flow
          streams.
     o    The third option is to weight grabs from individual
          streams based on sludge flow data or solids flux data.
          Whether to use sludge flow or solids flux will  depend
          on the sample streams, the parameters of interest, and
          the planned use of' the resulting data.  For example, if
          filter cake is being monitored for compliance with land
          application limits, solids flux data would be used as
          the criteria for proportioning grabs from parallel
          dewatering systems, since most land application limits
          are based on dry weight application rates.

 2.2.1.2  Availability of Flow Data and/or Solids Flux Data
     The availability of accurate solids flux data (weight/time)
or accurate flow data (volume/time) is an important consideration
in planning a sludge sampling program.  Most information
requirements relating to sludge characteristics involve,  at least
in part, the need for data on the solids flux of pollutant
parameters found in sludge discharged from a POTW.  The percent
solids should be determined on sludge samples.

     Portable flow monitoring devices are not well suited to
high-solids flow streams, and most sludge processing streams are
not designed in a manner which is physically conducive to the use
of these devices.  Thus, in most cases, it is necessary to rely
on existing integrated flow monitoring equipment.  Due to
difficulties in monitoring sludge flows, flow meters are high
maintenance items.   Frequent calibration of sludge flowmeters is
necessary in order to ensure accurate flow measurement.  This
data should be cross-checked against mass balance data.  When
ultimate use or disposal practices dictate monitoring sludge with
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a high solids content, liquid flow meters are replaced by gross
weight scales.  Table 2.1 summarizes the types of flow
measurement equipment employed to monitpr various sludge flows.

2.2.2  Sludge Sample Points
     The determination of the appropriate sludge sampling point
is dependent on the rationale behind the sampling.   For permits
and regulation enforcement, sludge samples must come from the
treatment unit process immediately preceding disposal or use.
For example, if. a POTW disposes of its.dewatered filter cakes in
a sanitary landfill, then sampling activity focuses on the output
sludge stream from the dewatering device (i.e., vacuum filter,
belt filter, etc.).  The sludge treatment processes commonly
employed are stabilization, dewatering, drying, composting, and
thermal reduction.  Table 2.2 summarizes sampling points for
these processes.  Other sludges sampling points may be necessary
to examine the origin or fate of pollutants within a POTW, (i.e.,
additional sludge samples from influent and output of other
processes may be needed).

2.3  SAMPLE COLLECTION
     Having selected appropriate sampling points for a sludge
sampling program, it is then necessary to determine the method
and equipment by which sampling will be carried out.  In doing
so, the following objectives should be considered:

     o    Each grab sample, or aliquot of a composite sample,
          must be as representative as possible of the total
          stream flow passing the sampling point
     o    Effort must be made to minimize the possibility of
          sample contamination
     o    The selected sampling method should be safe, convenient
          and efficient.
                          2-8

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           TABLE 2.1.  SLUDGE FLOW MEASUREMENT DEVICES
Application
           Measurement Means
Stabilized Sludge
Thickener
Dewatering

Drying
Composting
Thermal Reduction
       Venturi
       Flow Tube
       Magnetic Meter
       Positive Displacement Pump

       Magnetic Meter
       Positive Displacement Pump

       Belt press scales

       Bulk container or truck scales
                TABLE 2.2.   SLUDGE SAMPLING POINTS
Sludge Type
            Sampling Point
Anaerobically
Digested -

Aerobically
Digested -
Thickened
Sludges -
Sample from taps on the discharge side of
positive displacement pumps.

Sample from taps on discharge lines from pumps.
If batch digestion is used, sample directly
from the digester.  Two cautions are in order
concerning this practice:

(1) If aerated during sampling, air entrains in
the sample.  Volatile organic compounds may
purge with escaping air.

(2) When aeration is shut off, solids separate
rapidly in well digested sludge.

Sample from taps on the discharge side of
positive displacement pumps.
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                TABLE  2.2.
       SLUDGE SAMPLING POINTS
      (continued)
Sludae Tvne
        Sampling Point
Heat Treatment
Dewatered, Dried,
Composted, or
Thermally Reduced
various depths.-

   Dewatered:
Sample from taps on the discharge side of
positive displacement pumps after decanting.
Be careful when sampling heat treatment
sludge because of:

    (1) High tendency for solids'separation

    (2) High temperature of sample
        (frequently >60°C  as  sampled)  can
        cause problems with certain sample
        containers due to cooling and
        subsequent contraction of entrained
        gases.

Sample from material collection conveyors
and bulk containers.  Sample from many
locations within the sludge mass and at
      Belt Filter Press,
      Centrifuge/ Vacuum
      Filter Press

      Sludge Press
      (plate and frame)
      Drying Beds
   Compost piles
        Sample from sludge discharge chute.
        Sample from the storage bin; select
        four points within the storage bin,
        collect equal amount of sample from
        each point and combine.

        Divide bed into quarters, grab equal
        amounts of sample from the center of
        each quarter and combine to form a
        grab sample of the total bed.  Each
        grab sample should include the
        entire depth of the sludge (down to
        the sand).

        Sample directly from front-end
        loader as the sludge is being loaded
        into trucks to be hauled away.
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   Except for limitations on the use of automatic sampling
devices, the actual sampling techniques for sludges are similar
to those found in wastewater sampling.  The following sections
describe two important considerations for selecting appropriate
sludge sampling methods:  sampling equipment and proper sampling
practices.

2.3.1  Sampling Equipment
   In general, automatic sampling devices, which are widely used
for wastewater streams, do not work well for sludge streams
because of the solid.s content and viscosity of sludges.
Automatic samplers which use pumps to draw samples up a suction
tube cause solids separation if flow velocity in the suction and
discharge tube is too low.  This increases pump head requirements
and limits the range of tubing diameter.  A second problem which
occurs in the use of automatic samplers is fouling of tubing
and/or pump structure by sludge solids.  This results in
contamination of subsequent aliquots during composite sampling.
Sludge particles may also plug the sample tube or pumping
mechanism and interrupt sample collection.  Therefore, it is
preferable to sample liquid sludge streams manually, particularly
if sample taps can be provided on pump discharge lines.

   Sampling equipment must be made of materials which will not
contaminate or react with the sludge.  The best material choices
are Teflon, glass, and stainless steel because they are
relatively inert.  When the cost of Teflon and stainless steel
equipment prohibits or restricts their use, plastic, steel and/or
aluminum may be substituted for most sampling activities.  (If
steel equipment is used, ensure that galvanized or zinc coated
items are not used because these materials will readily release
zinc into the sample.)
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   Graduated glass or plastic pitchers or cylinders are used to
draw grabs for manually composted samples.  Stainless steel
pitchers are also commercially available, and are used to grab

samples from taps and also can be affixed to lengths of conduit

to sample from open channel flows.  Only aluminum conduits should

be used since most commercially available steel conduit is

galvanized.  In addition, only stainless steel clamps should be

used to attach the sample container to the conduit.


2.3.2  Proper Sampling Practices

   Listed below are practices that should be followed when

sampling sludges:


     o    Clean all sampling equipment between each sample period
          to prevent cross-contamination.  Cleaning consists of
          thorough washing with a laboratory detergent, thorough
          rinsing with tap water and then with at least three
          distilled water rinses.

     o    Sample aliquots should be composted directly into
          sample containers.  Sample containers, preservation of
          sample and allowable holding time prior to analysis are
          discussed in Section 2.5.

     o    When collecting samples for oil and grease analysis,
          sample directly into the sample container since oil and
          grease tend to adhere to surfaces.  Sample composites
          should be sent to the laboratory as a series of grab
          samples.

     o    Sample collection procedures should be adequately
          documented,- as discussed in Section 2.7.

     o    When collecting samples for organic volatiles or semi-
          volatiles, carefully pour liquid sludge into container
          so as to avoid entrapping air within sample.  Fill
          container to overflowing and screw on lid.  Check air
          bubbles by turning container upside down and tapping
          lid.  If air bubbles rise, open container and fill with
          additional sample.  For sludge cake, care-fully pack
          sludge into container so as to avoid air spaces.  Fill
          the container to overflowing and screw  on lid.
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          When collecting samples for dioxin/furan, fill the
          container to 4/5 full to enable expansion of samples
          when they are frozen.

          When collecting samples for pesticides/PCBs/herbicides,
          metals and nonconventionals, fill container to within
          1/2 inch of the top.to provide room for expansion
          should there be any gas production during sample
          shipment.
When sampling liquid sludges:
          To draw a fresh representative sludge sample from a
          tap:

          a)   Allow sufficient time following pump start up to
               clear line of stagnant sludge, and

          b)   Allow sludge to flow for several seconds from tap
               prior to sampling in order to flush out stagnant
               sludge and solids accumulated in the tap.

          Before drawing a sludge sample, rinse each piece of
          sampling equipment 3 times with sample to reduce the
          chance of contamination from the previous grab.

          To prevent solids separation in the sample, use glass,
          Teflon-coated stirring rods, or stainless steel spoons
          to mix the sample before splitting or transferring any
          portion of it to another container(s).
When sampling solid sludges:
          For either dewatered cakes, dried powder or compost
          product, combine equal amounts collected at various
          locations/depths for each grab sample to obtain a more
          representative sample.

          a)   To produce a sample from multiple sample locations
               (e.g., two or more dewatering units), combine the
               grab samples from each location (equal amounts or
               weighted based on flow or solids flux data) in a
               plastic or stainless steel pail and thoroughly mix
               the sample (with a scoop or spoon), then transfer
               it to sample containers.  This is not appropriate
               for volatile or microbial samples.
                          2-13

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          b)   When sampling drying beds, divide each bed into
               quarters.  From the center of each quarter,
               collect a single core sample through the entire
               depth of the sludge using a coring device.
               Usually a small amount of sand will be collected;
               avoid large amounts of sand.  Combine and
               thoroughly mix in plastic or stainless steel pail
               and transfer to sample containers.

2.4  SAMPLE SIZE, SAMPLE TYPE, AND SAMPLING FREQUENCY

Sample Size
     A proper sample is small enough to transport conveniently
                                             »
and handle carefully in the laboratory, but large enough to
accurately represent the  characteristics of the whole material.
Minimum sample sizes required for accurate analysis are specified
in each analytical method.  Table 2.3 lists minimum sample sizes
for some common analytical methods.  For methods not listed here,
consult an analytical methods reference or the laboratory for
further guidance.

Sample Type
     A grab sample collected at a particular time and location
can represent the composition of the source only at that time and
location.  In the case of most sludges, single grab samples will
adequately represent only the instantaneous composition of the
material being sampled.  The quality of a grab sample will be
improved if it is comprised of several smaller samples taken over
a period of a few minutes.

     A composite sample gives a better reflection of the time-
and location-weighted average concentrations that are found in
the sludge flow stream.  In most cases, the term "composite
sample" refers to a mixture of grab samples collected at the same
sampling point at different times.  Although a 24-hour composite
                          2-14

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                                         TABLE 2.3
           CONTAINERS, PRESERVATION, HOLDING TIMES, AND MINIMUM SAMPLE VOLUMES
                                                                              (1)
Wide-mouthed
Parameter Container
Inorganic Compounds
Asbestos
Metals
Chromium VI
Mercury
Metals except above
Organic Compounds
Extractables (including
phthalates , nitrosamines ,
nitroaromatics, isophorone,
polynuclear aromatic HC,
haloethers , chlorinated
HC and TCDD)
Extractable (phenols)
P,
P,G
P,G
P,G
G , tef lon-
lined cap
P, for
dioxin and
furan only
G, teflon-
lined cap
(2)
Preservative v '
None
Cool, 4°C
HN03 to pH<2
HNO3 to pH<2
Cool, 4°C
0.008% Na2S203
COOl, 4°C
H2SO4 to pH<2
Maximum . Minimum
Holding Time* ' Sample Volume*
None
24 hours
28 days
6 months
7 days M
40 days (a}
7 days M
40 days {ai
2000 mL
300' mL
500 mL
1000 mL
1000 mL
1000 mL
Purgeables (Halocarbons
and Aromatics)
Purgeables
(Acrolein and
Acrylonitrile)
G, teflon-
lined septa
G, teflon-
lined septa
OJ008% Na2S2O3

Cool 4°C
0.008%
1:1HC1 to pH 2

Cool 4°C
0.008% Na2S20
pH to 4 or 3
7 days
14 days in
darkness

14 days
>20 mL
>20 mL

-------
                                         TABLE  2.3  (Continued)
            CONTAINERS,  PRESERVATION,  HOLDING  TIMES,  AND MINIMUM SAMPLE VOLUMES(1)
Wide-mouthed                                         . .        Maximum   . .      Minimum
Parameter                    Container   Preservative* '     Holding Time* '  Sample Volume1 '

Pesticides & PCBs            G, teflon-    Cool 4°C            7 days ^        1000 mL
                             lined septa   0.008% NaSO       40 days (a*
(1)    40 CFR Part 136
(2)    Preservatives should be added to sampling containers prior to actual sampling
       episodes.  Holding times commence upon addition of sample to sampling container.
       Shipping of pre-preserved containers to the sample sites may be regulated under DOT
       hazardous materials regulations.  Shipping of preserved samples to the  laboratory
       is generally not regulated as a hazardous material.
(3)    Varies with analytical method.  Consult 40 CFR Part 136.
P =    Plastic  (Polyethylene)
G =    Glass (Non-etched Pyrex)
(a)    After extraction
(u)    Before extraction
(w/o)  Without preservatives

-------
sample (consisting of a number of time- or flow-weighted grab
samples)  is more representative than a grab sample, it can give a
picture of only one day's sludge quality.  Historical data is
necessary to truly represent the sludge quality.  A composite for
volatile components analysis is produced in the lab from grab
samples collected in the field.

Sampling Frequency
     As sludge quality is directly related to wastewater influent
quality (which can vary from day to day and hour to hour), a POTW
should sample and analyze its sludge frequently to obtain
representative data.  Collection of representative sludge data is
crucial because the permitting authority will use the resultant
analytical data to establish permit monitoring parameters and
frequencies, and thereafter, to assess compliance with the permit
and to ascertain if there is a potential for adverse environ-
mental impacts.  POTW operators should be aware that EPA's
"Strategy for Interim Implementation in Permits Issued to POTWs"
(draft June 1988) to be finalized during the fourth quarter of
1989) sets forth minimum recommended monitoring frequencies to be
included in the NPDES permit when it is reissued.  The Interim
Strategy is scheduled to be finalized in the summer of 1989.  The
NPDES permit writer may decide based on his/her best professional
judgment (BPJ) that more frequent monitoring is needed.  The
sampling frequency will be set out in the POTW's permit.

     To the extent practicable, the POTW should have a sludge
sampling program which adequately addresses random and cyclic
variation within the system and the potential for human exposure
to sludge once it is disposed of or used.

     o    Anticipated cyclical variation in pollutant loadings -
          although they are difficult to accurately predict,
        • anticipated cycles include daily industrial production
                          2-17

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          cycl.es, weekly industrial production cycles,  and other
          known or suspected production cycles, particularly
          those associated with intermittent batch discharges by
          significant industries.   Longer-term production cycles,
          including seasonal and annual/multi-year production
          cycles (e.g.,  business cycles),  do not need to be
          considered in determining monitoring frequency unless
          they are known to affect short-term variation in sludge
          quality.

     o    Risk of environmental exposures  - As the risk of
          environmental exposure from sludge use/disposal
          increases, a POTW should increase its sampling
          frequency to provide better information about potential
          variation in sludge quality.   For example,  a sludge
          that is applied to food-chain croplands should be
          sampled more frequently than sludge that is disposed of
          in a landfill that has an impermeable liner and a
          groundwater monitoring system.

     Other factors that should be considered in determining

sampling frequency include:


     o    Size - As influent flow increases, day-to-day sludge
          variability increases, as does outflow volume.  Thus,
        .  where high volumes exist, the risk of adverse exposure
          is higher.  Since variability and potential impact are
          major considerations, many sampling programs are based
          on size alone (e.g. 40 CFR Part  503 proposed rule).
          Size is also an easy factor to measure.

     o    Percentage of industrial flow -  While sludge quality
          variability is directly related to the individual
          characteristics of each POTW, POTWs with little or no
          commercial/industrial contributors in the system can
          expect relatively small variation in sludge quality.
          POTWs with significant industrial contributions can
          expect to have monthly, weekly and even daily variation
          in sludge quality.

     o    Treatment plant characteristics - As either detention
          time or mixing increases within a treatment plant,
          sampling frequency can be reduced since treatment
          processes will effectively composite sludge to a
          greater degree.  For example, high rate digestion and
          storage/blending facilities will provide mechanical
          mixing of sludge.  Other plant technologies, such as
          anaerobic digestion, aerobic digestion and storage,
                          2-18

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          provide longer sludge detention times, enabling greater
          mixing through physical processes such as diffusion,
          convection, etc.  For combined sewer systems, a
          sampling strategy may be designed to monitor the
          effects of storm events on sludge quality.

     Another consideration is the type(s) of information a POTW
wishes to collect.  If, for example, a POTW desires to measure
daily variation over a typical week, the POTW may collect and
analyze seven or more 24-hour composite samples for the
pollutant.  Similarly, if a POTW wishes to measure variation
within a single day, the P.OTW may .collect and analyze several •
grab samples taken at different times during the day.

2.5  SAMPLE PREPARATION AND PRESERVATION
     There is the potential for errors of varying severity to be
introduced during sample collection and storage which affect
analytical determinations.  To avoid potential errors and
maintain sample integrity, POTW operators should carefully
consider the following:

     o  Sample Container Material
     o  Sample Container Preparation
     o  Sample Preservation
     o  Holding Time Prior to Analysis.

     Table 2.3 lists recommended container materials,
preservatives, holding times, and minimum sample volumes for the
analysis of sludges.  For method-specific details concerning .all
facets of sample preparation and preservation, consult the
references cited in 40 CFR Part 136, "Guidelines for Establishing
Test Procedures for the Analysis of Pollutants."
                          2-19

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2.5.1  Sample Container Material
     The requirements for sample containers are method-specific,
but containers are usually made of Teflon, glass or polyethylene.
Sample containers should be wide-mouthed for sludge sampling,
particularly for solids (cake) sampling.  Teflon containers are
typically supplied with Teflon caps.  Glass containers frequently
are supplied with caps which can cause sample contamination
(phenol, phthalate compounds).  For organic parameters, these
glass container caps should be fitted with Teflon liners;
aluminum liners could be used but they must be fitted precisely
                                               «
within the circumference of the cap to prevent tearing and
possible sample leakage.

2.5.2  Sample Container Preoaratipn
     Proper sample container preparation is necessary to prevent
contamination of the sample by material left from the container
manufacturing process or that has otherwise been introduced into
the unused sample containers.  All containers should be washed
with a good quality laboratory detergent, thoroughly rinsed with
tap water, and then rinsed at least 3 times with distilled water
prior to air drying.  Additional container preparations for
analysis of particular parameters are described below:

     o    Extractable Organics - Use glass containers with
          Teflon-lined caps only.  Wash containers as above and
          rinse with solvent  (typically methylene chloride); air-
          dry.
     o    Volatile Organics - Prepare containers by washing and
          rinsing as described above, and then bake both vials
          and septums at 105°C until dry.   Cool in an
          organic-free atmosphere.
     o    Metals - Wash and rinse as described above.  Then rinse
          with dilute acid (1 part deionized, distilled water to
          1 part nitric acid  (HN03)),  followed by two rinses with
          deionized, distilled water.
                          2-20

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2.5.3  Sample Preservation

     Table 2.3 presents U.S. EPA's recommended preservation

protocols.  These protocols are primarily intended for effluent

monitoring; however, they are generally applicable to liquid
sludge sampling.


     The following are specific recommendations regarding sample
preservation:


     o    In instances where it is desirable to split,one
          composite sample into several fractions, each having
          incompatible preservation requirements, it is
          acceptable to chill the entire sample to 4°C during
          compositing.  Following the sample period, the
          composite is. then cautiously mixed and split into
          various fractions, each of which is appropriately
          preserved.  This does not apply to samples for analysis
          of volatile, semivolatile or microbial contaminants.

     o    If processing of microbial samples cannot occur within
          one hour of collection, iced coolers should be used for
          storage during transport to the lab.  Samples should be
          held below 10°C during the maximum transport time of 6
          hours.  Note:  these samples must be immediately
          refrigerated and processed at the lab within 2 hours of
          receipt.

     o    Whenever possible, sample containers should be
          pre-preserved.  Thus, grab samples are preserved upon
          sampling and composite samples are preserved during
          compositing.  This is not appropriate, however, when
          sampling for metals or pathogens.

     o    In general, all samples should be chilled (4°C)  during
          compositing and holding.

     o    For solid sludge samples  (cake), adding chemical pre-
          servative is generally not useful since the
          preservative usually does not penetrate the sludge
          matrix.  Preservation consists of chilling to 4°C.

     o    When sampling and holding sludges, particularly
          biologically active sludges, gas production in the
          sealed container may cause an explosion unless the
          pressure is periodically released.  This should not be
                          2-21

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          done however if volatile or semivolatile pollutants are
          to be analyzed.
                                                      t

2.5.4  Holding Time Prior to Analysis
     Table 2.3 lists the maximum holding times for various
pollutant samples.  Table 2.4 lists some potential interferences
that may affect samples during shipping and storage.   There are
many more interferences associated with particular analytical
methods, which are discussed further in chapter 3 as well as in
the particular methodology.

2.6  PACKAGING AND SHIPPING
     When analysis will be performed away from the sampling
locale, samples must be packaged and transported.

2.6.1  Packaging
     Sample containers must be packaged in order to protect them
and to reduce the risk of leakage.  Containers should be held
upright and cushioned from shock.  In addition, sufficient
insulation and/or artificial refrigerant ("blue ice") should be
provided to maintain a sample temperature of 4°C  for  the duration
of transportation.

2.6.2  Transportation Regulations
     The following guidelines control the shipment of wastewater
and sludge samples:

     o    Unpreserved normal (i.e., not heavily contaminated)
          environmental samples are not regulated under DOT
          Hazardous Material Regulations.  These samples may be
          shipped following the packaging guidelines in Section
          2.6.1, and using a commercial carrier, etc.  To assure
          proper sample temperature, transit time should be held
          to less than 24 hours.
                          2-22

-------
                           TABLE 2.4

             POTENTIAL INTERFERENCES ASSOCIATED WITH
                   SAMPLE SHIPPING AND STORAGE
Parameter
  Interferences
        Prevention
Acidity

Ammonia


Cyanide

Chromium VI

Phenols



Silica

Sulfide

Sulfite

Organic
Chemicals
Carbon dioxide loss   Fill container completely
Chlorine
Volatilization

Sulfides

Reducing agents

Hydrogen sulfide,
Sulfur dioxide
Oxidizing agents
Aeration, agitation

Aeration, agitation

Photodegradation
 Sodium thiosulfate
. Fill container completely

 Cadmium nitrate, tetrahydrate

 Minimize holding time

 Aerate

 Ferrous sulfate

 Avoid freezing

 Fill container completely

 Fill container completely

 Use brown glass container
    Other than those addressed by protocols, shown in Table 2.3

-------
     o    When environmental samples are preserved as recommended
          (see Table  2.5), they may be shipped as non-hazardous
          samples.
     The guidelines above assume no material is present in the
samples at concentrations which would result in a "hazardous" DOT
rating.  Should hazardous material  (as defined by DOT) be
present, DOT regulations concerning packaging, transportation and
labeling must be  followed (see 49 CFR Parts 172, 173 and 178).  A
material is considered hazardous by DOT if it fails one of the
four characteristic tests of:  corrosivity, ignitability,
reactivity and EP Toxicity [see "Test Methods for Evaluating
Solid Waste, SW 846,  1986 for exact methods].  Municipal sewage
sludges labeled as hazardous are usually from failed EP Toxicity
tests and occasionally from reactivity tests.

'2.7  DOCUMENTATION
     Adequate documentation of sludge sampling activities  (1) is
important for general program quality assurance/quality control,
and  (2) is required by most monitoring regulations.  Proper
sampling activity documentation includes proper sample labeling,
chain-of-custody  procedures and a log book of sampling
activities.  The  number of people in the chain of custody  should
be kept to a minimum  to limit the possibility of contamination
and  to increase accountability.

2.7.1  Sample Labeling

     It is important  that each sample label include the following
information  (items  in bold text are minimum elements):

     o  Sampling  Organization Name
     o  Facility  Name (being sampled)
     o  Bottle Number (specific to  container
                          2-24

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                                        TABLE  2.5
     STANDARD PRESERVATIVES LISTED IN THE HAZARDOUS MATERIALS TABLE (49 CFR 172.101)
USED BY  EPA  FOR  PRESERVATION  OF WATER,  EFFLUENT, BIOLOGICAL,.SEDIMENT, AND  SLUDGE  SAMPLES
Sample Type/
Parameter
                 Preservative
     PH
Recommendation
     Quantity of
Preservative Added
     Per Liter*
                                                                               % of
  WT.
Preservative
Organic Carbon
Nitrogen Species
Metals, Hardness**
Nitrogen Species
Hydrochloric acid
Mercuric chloride
Nitric acid
Sulfuric acid
<2 ->1
N.A.
<2 - >1
<2 - >1
2 ml of 1:1
40 mg
5 ml of Cone. (70%)
2 ml of 36N
0.04%
0.004%
0.35%
0.35%
COD, Oil & Grease,
P (hydrolyzable)
Organic Carbon

Cyanides

Phenolics

Biological - Fish &
Shellfish Tissue***
                 Sodium hydroxide

               Ortho-phosphoric acid

                 Freezing 0°C
                  (Dry Ice)
    <4 - >2

     N.A.
2 ml of ION            0.080%

to yield desired pH

N.A;                   N.A.
     Sample dilution must be avoided.   The volume of washings must be minimized and any
     dilution that does occur must be documented and the data corrected for the dilution.
**
The sample may be initially preserved by cooling and immediately shipping it to the
laboratory.  Upon receipt in the laboratory, the sample must be acidified with cone
     to pH<2.  At time of analysis, sample container should be thoroughly rinsed
     witn 1:1HN03; washings should be added to sample.

***  Dry ice is classified as an ORM-A hazard by DOT.   There is no labeling requirement
     for samples preserved with dry ice, but each package must be plainly and durably
     marked on at least one side or edge with the designation ORM-A.   Advance arrangements
     which must be met to ship dry ice are found in DOT regulation 49 CFR 173.616.

-------
     o  Sample Number (specific to sampling event i.e.  location)
     o  Type of sample, i.e., grab, 24 hour composite,  etc.
     o  Date, Time (24 hour time is preferable, i.e., 1600 vs.
          4:00 p.m.)
     o  Sample Location
     o  Preservatives
     o  Analytical Parameter(s)
     o  Collector
     o  Special Conditions or Remarks.
     Labels and ink should be waterproof.   Fix labels to con-
tainers with clear waterproof tape.  Tape  completely around
container and over label to prevent accidental label loss or ink
smear during shipping and handling.

2.7.2  Chain-of-Custody  .
     Each sample shipment requires a chain-of-custody record.  A
chain-of-custody document provides a record of sample transfer
from person to person.  This document helps protect the integrity
of the sample by ensuring that only authorized persons have
custody of the sample.  In addition, the chain-of-custody
procedure ensures an enforceable record of sample transfer which
is necessary if the sample results are to  be used in a judicial
proceeding alleging violations of sludge standards.  This
document shall record each sample's collection and handling
history from time of collection until analysis as well as the
information listed on each sample bottle.   All personnel handling
the sample shall sign, date and note the time of day on the
chain-of-custody document.  A sample chain-of-custody document is
provided in Appendix A.
                          2-26

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2.7.3  Sampling Log Book
     All sampling activities should also be documented in a bound
log book.  This book duplicates all information recommended for
the chain-of-custody document above, and notes all relevant
observations regarding sample stream conditions.

2.8  SAFETY CONSIDERATIONS
     Safety is important in sludge sampling, especially since
many sampling points preclude direct collection of grab samples.
Several safety considerations are noteworthy given the potential
health-related effects of sewage and sludge, and the hazards
associated with treatment plant equipment (water, electricity,
moving components, etc.).

     Personal hygiene is important for all personnel involved in
sludge sampling efforts.  Sludge presents a unique health hazard,
not only because of the potential presence of toxic substances,
but also because of the abundance of pathogens  (bacteria, viruses
and worms).  As a precautionary measure, inoculations are
recommended for all personnel who have direct contact with sludge
(as well as any wastewater) samples.  As a minimum, inoculation
should include diseases such as typhoid and tetanus.  Avoidance
of direct sludge contact is preferred and is possible if proper
precautions are taken..  Wear rubber or latex gloves at all times,
especially while collecting or handling samples, and use
waterproof garments when the risk of splashing exists.  Wash any
cuts or scrapes thoroughly and treat immediately.

     Gas production from biologically active sludge samples may
cause pressure build up, especially if the samples are not stored
at 4°C as recommended in Table 2.3.   Treating samples  with the
appropriate preservatives  (e.g., acids for metals samples) as
                          2-27

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well as refrigeration will significantly suppress biological
activity and therefore gas evolution.  However, except for
volatile and semi-volatile analysis samples, pressure may need to
be periodically released to prevent explosions of the sealed
sampling containers.  The field control sample should also be
vented to expose it to the same potential contaminants.

     There are several universal safety precautions that are
applicable to sludge sampling as well.  When sampling sludge in
confined areas, particularly around anaerobic digesters,
                        *
dangerous gases may be'present.  These gases may include either
explosive vapors (methane), poisonous mixtures (including
hydrogen sulfide), or oxygen-deprived atmospheres (carbon
dioxide).  Explosive vapors require care to avoid sparks and
possible ignition.  These situations necessitate adequately
ventilated equipment, gas detection meters and backup breathing
apparatus.  Exercise care around open pits or uncovered holes.
Proper lighting increases the visibility of such hazards.  Loose
or dangling garments (ties, scarves, etc.) should not be worn
around equipment with moving parts, especially pumps.  Exercise
extra awareness around pumps controlled by intermittent timers.
Finally, be very careful when sampling high pressure sludge lines
or lines containing high temperature, thermally-conditioned
sludges (i.e., Zimpro or Porteus) in order to avoid injury by
either high pressure streams or burns.
                          2-28

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                    3.  ANALYTICAL PROCEDURES

     Sewage sludge is compositionaliy diverse, rich in organic
matter, and highly variable in physical and chemical properties.
Sewage sludge analysis is difficult because of the inherent
complexity of sludge matrices.  Matrix complexity often results
in significant analytical interference which can lead to poor
analytical accuracy and precision with a resultant loss of data
reliability.  For example, matrix interference, which is
exacerbated in sludges, can both mask the identity of analytes by
suppressing instrumental response, or falsely contribute to a
positive response.

     Variations in the physical and chemical properties of sewage
sludge often make it difficult to obtain samples which represent
the material as a whole.  The diversity of sludge
characteristics, coupled with the heterogeneous nature of
sludges, presents a considerable challenge to precise and
accurate determinations of trace levels of pollutants in sludges.
Often sludge samples must be diluted to attain analytical
results.  A tenfold sample dilution means a tenfold increase in
the detection limit (e.g., 1 ppm to 10 ppm).  This increases the
complexity of attaining accurate, precise data.

     The following sections provide a summary of the analytical
techniques available for characterization of the sewage sludge
and soil constituents considered important in the selection of
use or disposal options.  Analytical techniques for conventional
pollutants, inorganics, priority pollutant metals, priority
pollutant organics, and pathogenic organisms are discussed.
                               3-1

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3.1  CONVENTIONAL AND INORGANIC POLLUTANT PARAMETERS
     Conventional pollutant parameters have historically been the
focal point of sewage sludge analyses.  The parameters normally
associated with this group include total suspended solids, pH,
oil and grease, BOD and fecal coliform.  Inorganics, which have
also been of concern, include phosphorus species, nitrogen
species, phenolics, and total cyanide.  As Table 3.1 indicates,
the analytical protocols commonly employed for these analyses are
adaptations of gravimetric or colorimetric techniques developed
for aqueous samples.

     Existing federal regulations (40 CFR Part 257) require POTWs
that apply sludge to food-chain croplands to measure the pH of
the sludge-soil mixture and background soil cation exchange
capacity (CEC).  Soil pH should be measured using a 1:1 solution
of sludge-soil mixture and deionized water (see Table 3.1).  For
distinctly acid soils, CEC should be measured using the summation
method (see Table 3.1).  For neutral, saline, or calcareous
soils, the sodium acetate method should be used (see Table 3.1). '

     Another inorganic of more recent concern is asbestos.
Asbestos is a generic term which refers to naturally occurring,
commercially useful fibrous silicate mineral.  There are two
types.  Chrysotile, which comprises 93 percent of the current
asbestos production, is a hydrated magnesium silicate which
exhibits a much higher cancer risk for textile workers.
Amphibole, which occurs in five forms, crocidolite, amosite,
actinolite, tremolite and anthrophyllite, is a hydrated silica
associated with various lung carcinogenic trace metals (nickel,
chromium, aluminum and iron).  Crocidolite poses the greatest
health risk of all asbestos types and is the riskiest to miners
and millers.
                               3-2

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                                         TABLE 3.1

        ANALYTICAL  TECHNIQUES  FOR CONVENTIONAL AND INORGANIC  POLLUTANTS  IN SLUDGE
Parameter
             Analytical        Aqueous
Preparation  Technique  QA/QC Detection
Techniques      (a)      (b)  Limit (mg/1)
Comments
                        Method
Phos-
phorous
(Ortho &
Total)
Total
Kjeldahl
Nitrogen
Ammonia
Nitrate
Nitrate-
Nitrite
Acidic Digestion C
Turbid samples
must be filtered
after digestion
H2S04 digestion C
Colorimetric C
reaction ISE
Reaction to C
brucine sulfate or
Nitrate-nitrite N
minus Nitrite N
Hydrazine or C
Cd reduction
B 0.001 - High iron concentration
St can cause precipitation
Sp and loss of phosphorous
- Turbidity interference
- 24 hr-holdinq time
- Digestion solution 2
B 0.05 times for sludge
St - 24 hr-holding time
- Fe + Cr catalyze; Cu
inhibits reaction
Sp 0.05 - Hg can complex with NH,
- Filter sample
- Distillation required
prior to analysis
0.1 - Dissolved organic
matter
0.05 - Filter sample for Cd
- Strong oxidizing
(1)
(1)
351
(1)
350
(2)
B , D
(1)
(3)
(1)
or
365.3
.2, 3
350.1
.2, 3
417A,
. E. G
352.1
9200
353.1,
353.2
Nitrite   Diazotization
                                0.5
or reducing agents
Suspended matter in
reduction column
Samples which contain high
cone, of metals or organics
                        (1)
                        (2)
                     354.1
                     419

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                                  TABLE 3.1  (Continued)

        ANALYTICAL TECHNIQUES  FOR  CONVENTIONAL  AND  INORGANIC POLLUTANTS IN SLUDGE
Parameter
             Analytical        Aqueous
Preparation  Technique  QA/QC Detection
Techniques      (a)      (b)  Limit (mg/1)
Comments
Method
Cyanide
Phenolics
Total
Organic
Carbon
Chemical
Oxygen
Demand
CN converted to
HCN by reflux-
distillation
C
Distillation and C
extraction
Inorganic Catalytic
carbon combustion &
removal dispersive 1$
Oxidation to Titration
potassium dichro-
mate and HC1
Bio- Incubation
chemical
Oxycjen Demand
Oil and
Grease
PH
CEC
Solvent
extraction
Solution in
suspension with
fluid
BaClVtreatment
(acid exchange)
(base exchanae)
Measurement
of reduction
in DO
G
ISE
T
C
B 0.02
St
So
B 0.002
St
Sp
B 1.0
St
So
B 5.0
St
Sp
B 2.0
St
sp
B 5.0
Sp
St 	
None cited in
references
- Fatty acids and
sulfides interfere
- 24 hr-holding time
- Sulphur compounds and
oxidizing agents
interfere
- Carbonate + bicarbonate
interfere
- Possible loss of
volatiles
- Chloride oxidation
could be an
interference
- 5-day incubator

- Interference from solids
and oily residues
- Acid soils
(1) 335.2
(3) 9010,
or 9012
(1) 420.1
(2) 510A
or C
(3) 9065,
9066. 9067
(1) 415.1
(2) 505A
(3) 9060
(1) 410.1,
(Block
digestion)
(2) 1508 A
or B
(1) 405.1
(2) 507
(1) 413.1,2
(2) 503A, D
(3) 9070,
or 9071
(1) 150.1
(3) 9040
(4) p. 900,
57-4
(3) 9080
(4) Ibid.

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                                  TABLE 3.1  (Continued)

        ANALYTICAL TECHNIQUES FOR CONVENTIONAL AND INORGANIC POLLUTANTS IN SLUDGE

Analytical Aqueous
Preparation Technique QA/QC Detection
Parameter Techniques (a) (b) Limit (mg/1) Comments
CEC




Solids

% Solids

Na acetate Emission One B No data - Neutral, saline, or
sludge sol?n, or per available calcareous soils
isopropanol absorption batch
wash , NH4 AAS
acetate exchanae
Filtration Gravimetric B 4.0-10.0

Evaporation Gravimetric B N/A

(1) Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020 , March
(2) Standard Methods for the Examination of Water and Wastewater , 16th Edition

Method
(3) 9081
(4) p. 891



(1) 160.1
or , 5
(1) 160.3
(2) 209A
1983.
, Mary Ann
     Franson, managing  ed., American  Public  Health Association, Washington, DC, 1985.

(3)   Test  Methods  for Evaluating  Solid Waste.  Third Edition,  (SW-846), EPA, September
     1986.

(4)   "Methods of Soil Analysis",  Agronomy Monograph Number  9, C.A. Black, ed., American
     Society of Agronomy, Madison, Wisconsin,  1965.

(a)   C  - Colorimetric;  DO - Dissolved Oxygen;  G  - Gravimetric; IR - Infrared; ISE - Ion
     Selective Electrode; S -  Spectrophotometric; T - Titration

(b)   B  -  Blank(s);  St  - Standards; Sp - Spike(s)

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     In certain cases, such as when large scale asbestos removal
is/will occur during the permit term or in municipalities where
asbestos industries are located, the permit writer or the
permittee may feel that sampling the sewage sludge for asbestos
is warranted.  Consult Table 2.4 for the appropriate sample
sizes, containers, preservatives and holding times.  Unless
sample preparation will be within 48 hours, the sample should be
refrigerated or stored in the dark to prevent bacterial growth.

     Although there' are tests which differentiate between the
various asbestos types, current research does not associate
health risk with specific types.  The risk from asbestos is
directly proportional to the concentration of airborne respirable
particles.  Thus current recommended analytical detection methods
count fibers per area.  Respirable particles are those with a
diameter (length in this case) of less than 2 microns, which can
only be detected using transmission electron microscopy (TEM).
The polarized light microscopy  (PLM) method does not detect
respirable particles.

3.2  METALS
     There are several analytical techniques used for the
determination of metals in sewage sludge, with variations in both
the sample preparation and analysis steps.  A discussion of these
techniques follows.

3.2.1  Analyte Isolation/Preparation Overview
     Two approaches are currently used to evaluate the
concentrations of metal contaminants in sludges.  The most
frequently used approach involves determination of the total
metal content or other materials of interest, without regard to
chemical form.  The analytical techniques for such determinations
                               3-6

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are designed to solubilize all of the metal species (bound to
organic particulates and mineralogically bound).   In the other
approach, often referred to as the "leachate approach," the
proportion of the total contaminant loading which will become
available or mobilized under environmental conditions is
determined.  Thus, leachate techniques are designed to mimic a
given environmental scenario.  With either approach, the
complexity and variability of sludge matrices has made the
development of sample preparation techniques a great analytical
challenge.

     The two primary steps for sample preparation of metals in
sewage sludge are (1) dissolution of the sample portion
containing the metal components of interest, and (2) elimination
of inorganic and organic interferences.  The preparation
procedure must be capable of effectively liberating the analytes
from the solid constituents, solubilizing the elemental species,
homogenizing the sample phase(s) of interest, as well as
completely oxidizing the associated organics.  Sludge matrices
are challenging in this regard because of the high organic levels
and solids loadings characteristics.

     All state-of-the-art sample preparation procedures for total
metal determinations depend on acid-mediated digestions and
chemical or physical oxidation techniques.  The approach involves
the use of strong acid and elevated temperature digestion
procedures in combination with chemical or physical oxidants.
The modifications which have been used include variations in
acids, oxidation reagents, physical oxidation techniques,
reaction conditions, and/or the sequence in which components are
employed.  Acids used most frequently include nitric acid (HN03),
hydrofluoric acid (HF), hydrochloric acid (HCL), and perchloric
acid (HCL04) ;  while  hydrogen peroxide and perchloric acid are
                               3-7

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common oxidizing reagents.  High temperature (550°OC)  combustion
and low temperature plasma ashing (LTPA) have been used success-
fully as physical oxidants.  Closed system digestion procedures
are also used successfully.

     Two closely related techniques to estimate the amount of
inorganic and organic contaminants which may be leached from the
sludge after disposal in landfills or surface impoundments are
the Extraction Procedure protocol and the Toxicity Characteristic
Leachate Procedure.  In both procedures the sludge is maintained
in an aqueous slurry under a given set of conditions, after which
contaminant levels are measured on the filtered aqueous media.
The Extraction Procedure (EP) test developed by EPA (in response
to RCRA legislation) to evaluate the impact of landfill waste
disposal practices on subsurface and surface waters (40 CFR Part
261 Appendix II) evaluates criteria for 8 metals and 6
pesticides.  The proposed Toxicity Characteristic Leaching
Procedure  (TCLP) 51 Federal Register 21648 is expected to be
promulgated in August/September of 1989.  The TCLP test which
evaluates the same 8 metals and 6 pesticides and an additional 38
compounds will replace the EP test after promulgation.

3.2.2  Analytical Techniques for Metals

3.2.2.1  Sample Preparation/Digestion
     Table 3.2 shows the sample preparation/digestion technique
recommended by the USEPA.  Method 3050  (SW-846, 3rd ed.) is an
acid digestion procedure used to prepare sediments, sludges, and
soil samples for analysis by flame or furnace atomic absorption
spectroscopy (FLAA and GFAA, respectively) or by inductively
coupled argon plasma spectroscopy (ICAP).  Samples prepared by
this method may be analyzed by ICAP for all the metals listed
below, or by FLAA or GFAA as indicated:
                               3-8

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            FLAA
                               GFAA
Aluminum
Antimony
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Nickel
Potassium
Silver
Sodium
Thallium
Tin
Vanadium
Zinc
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Copper
Iron
Lead
Manganese
Nickel
Selenium
Silver
Zinc
Thallium
Vanadium
     Method 3050 prepares samples for analysis of total metals
(except mercury, silver and antimony) determination through
vigorous digestion in nitric acid and hydrogen peroxide followed
by dilution with either nitric or hydrochloric acid.  This method
is not appropriate for mercury, silver,, and antimony because of
potential for volatilization. For the digestion and analysis
procedures for mercury, silver and antimony, see section 3.2.2.2.


3.2.2.2  Analytical Detection Methods

     Metals should be analyzed using either Atomic Absorption
Spectrometry (AAS) or Inductively Coupled Argon Plasma (ICAP).
The following discussion generally describes both methods.


     Inductively Coupled Argon Plasma is a form of optical
emission spectroscopy which uses an argon plasma to excite ions
and atoms.  This process causes the ions and atoms to emit light
which is measured as a signal. The signal response is
proportional to concentration level, and each element emits a
uniquely characteristic light.  This technique poses several
advantages.  A linear relationship between concentration and
signal response can be expected over 4-6 orders of magnitude.
Detection limits are low (although not as low as AAS, and not .
strongly inhibited by matrix variation); costs are moderate since
                               3-9

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                           TABLE 3.2.
                RECOMMENDED PREPARATION TECHNIQUE
             FOR ELEMENTAL ANALYSIS  OF SLUDGE SAMPLES
                          METHOD 3050(1)
1)   Mix the sample thoroughly to achieve homogeneity.  For each
     digestion procedure, weigh to the nearest 0.01 g and
     transfer to a conical beaker a 1.00- to 2.00-g portion of
     sample.

2)   Add 10 ml of 1:1 HN03,  mix the  slurry,  and cover  with a
     watch glass.  Heat the sample to 95°C and reflux  for 10 to
     15 min without boiling.  Allow the sample to cool, add 5 ml
     of concentrated HNO3, replace the watch glass,  and reflux
     for 30 min.  Repeat this last step to 'ensure complete
     oxidation.  Using a ribbed watch glass, allow the solution
     to evaporate to 5 ml without boiling, while maintaining a
     layer of solution over the bottom of the beaker.

3)   After step 2 has been completed and the sample has cooled,
     add 2 ml of Type II water and 3 ml of 30% H2O2.   Cover  the
     beaker with a watch glass and return the covered beaker to
     the hot plate for warming and to start the peroxide
     reaction.  Care must be taken to ensure that losses do not
     occur due to excessively vigorous effervescence.   Heat until
     effervescence subsides and cool the beaker.

4)   Continue to add 30% H202 in  1-ml  aliquots while warming
     until the effervescence is minimal or until the general
     sample appearance is unchanged.
     NOTE:  Do not add more than a total of 10 ml 30% H2O2.
(1)  USEPA "TEST METHODS FOR EVALUATING SOLID WASTE:  VOLUME 1A"
     SW-846-3rd EDITION, NOVEMBER 1986.  CHAPTER 3, PP. 3050-1,5,
                               3-10

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many elements may be determined at once; and analysis time is
fairly rapid.  The primary drawbacks are: matrix interferences
(as with all analyses); the fact that solid samples cannot be
analyzed directly as in AAS; and the high cost of purchasing ICAP
instruments  (more than $100,000).

     The basic principle behind atomic absorption spectroscopy is
the opposite of the emission method, ICAP.  In AAS, the analyte
(metal) is dissociated into atoms in a flame or furnace, and
passed through a light beam from the reference source.  This
reference source emits a beam of the*characteristic atomic
spectrum of the analyte.  The analyte in the sample will absorb
this energy thus decreasing the original signal to the detector
from the reference beam.  Since absorption is directly
proportional to concentration, the analyte concentration can be
determined.  Selection of a specific wavelength which corresponds
to one of the more intense characteristic line of the analyters
spectra allows for high element specificity.  For this reason,
AAS is more responsive than ICAP to lower concentrations of
metals in sludge.  However, this very precise nature of AAS is
also the cause of its major drawback: only one elemental
determination per sample is possible at a time.  Thus, the total
analysis time of AAS is significantly greater than that of ICAP
when many metals are present in the sample.

     In sewage sludge applications, it is important to realize
that both of these analytical techniques are reliable tools and
neither offers a significant technical advantage over the other.
However, ICAP's capability to simultaneously analyze multiple
elements is a tremendous advantage in terms of sample throughput
and labor savings, which may outweigh the noted limitations.1 For
sludge applications, EPA recommends either method and leaves the
                               3-11

-------
\
    final decision to individual POTWs.  Table 3.3 summarizes the
    relative advantages and disadvantages of ICAP and AAS.


                                TABLE 3.3

                    COMPARISON  SUMMARY OF  ICAP AND AAS


                                   ICAPAAS
    Cost for Instrument             -                  +
    Cost per Sample                 +                  +
    Detection Limits                +                  +
    Precision                       +                  +
    Linear Working Range            +
    Sensitivity                     +                  ++
    Number of Elements/Sample       +
    Analysis Time                   +
    Spectral Interference           -                  +
    Matrix Interference             +
        disadvantage
     +  advantage
    ++  extra advantage
    ICAP Method 6010

         EPA recommends Method 6010 for the determination of metals

    in solution by Inductively Coupled Argon Plasma atomic emission

    spectroscopy (ICAP).  This method can be found in the USEPA

    manual "Test Methods for Evaluating Solid Waste," (SW-846, Nov.

    1986, 3rd Ed., Vol 1A, pp. 6010-1,17).  The method is applicable
    to a large number of metals and wastes.  All matrices, including

    ground water, aqueous samples, EP extracts, industrial wastes,

    soils, sludges, sediments, and other solid wastes, require

    digestion prior to analysis.  EPA recommends digestion Method

    3050 (SW-846, 3rd Ed. - see Section 3.2.2.1).
                                   3-12

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     Elements for which Method 6010 is applicable are listed in
Table 3.4.  Detection limits, sensitivity, and optimum ranges of
the metals will vary with the matrices and model of spectrometer.
The data shown in Table 3.4 provide concentration ranges for
clean (interference-free) aqueous samples.  Due to matrix
interferences, the detection limits in typical sludge samples
will be somewhat higher.  Use of thi.s method is restricted to
spectroscopists who are knowledgeable in the correction of
spectral, chemical, and physical interferences.

Atomic Absorption Methods
     EPA recommends use of the methods listed in the manual "Test
Methods for Evaluating Solid Waste" (SW-846, Nov. 1986, 3rd Ed.,
Vol 1A) for the determination of metals in solution by atomic
absorption spectroscopy.  A complete set of procedures for each
metal-specific method may be found on pages 7000-1 to 7950-3.
These methods'are simple, rapid, and applicable to a large number
of metals in drinking, surface, and saline waters as well as
domestic and "industrial wastes.  Ground water, aqueous samples
other than drinking water, EP extracts, industrial wastes, soils,
sludges, sediments, and other wastes require digestion prior to
analysis.  EPA recommends digestion Method 3050  (SW^846, 3rd Ed.
- see section 3.2.2.1).

     Detection limits, sensitivity, and optimum ranges of the
metals will vary with the matrices and models of atomic
absorption spectrometers.  The data shown in Table 3.5 provide
some indication of the detection limits obtainable by direct
aspiration and by furnace techniques.  Due to the matrix
  For drinking water and other non-sludge applications,  priority
pollutant scans may require very low contaminant detection
levels.  Therefore, there may be no choice except to rely on the
lower detection limit capability of graphite furnace AAS.  This,
in turn, will determine-the digestion method used.
                               3-13

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                 TABLE 3.4

RECOMMENDED INDUCTIVELY COUPLED WAVELENGTHS
AND ESTIMATED INSTRUMENTAL DETECTION LIMITS
Element
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Molybdenum
Nickel
Potassium
Wavelength3
(nm)
308.215
206.833
193.696
455.403
313.042
249.773
226.502
317.933
267.716
228.616
324.754
259.940
220.353
279.079
257.610
202.030
231.604
766.491
Wastewater EMSL's Best EMSL's
Estimated SLUDGE Estimate of
Detection Detection Routine
Limitb Limit0 SLUDGE Limit
(ug/L) (ug/L) (ug/L)
45
32
53
2 —
0.3
5
41 5
10
•j 	 	
7
6 5 10
7 —
42 . 20 50
30
2
8 10 30
15
See note d —

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                          TABLE  3.4   (cont.)

             RECOMMENDED INDUCTIVELY COUPLED WAVELENGTHS
             AND ESTIMATED INSTRUMENTAL DETECTION LIMITS
Element
Selenium
Silicon
Silver
Sodium
Thallium
Vanadium
Zinc
Wavelength3
(nm)
196.026
288.158
328.068
588.995
190.864
292.402
213. 856
Wastewater
Estimated
Detection
Limitb
(ug/L)
75
58
7
29
40
8
2
EMSL's Best
SLUDGE
Detection
Limit0
(ug/L)
75
—
—
--
100
—
5
EMSL'S
Estimate of
Routine
SLUDGE Limit
(ug/L) .
100
—
—
—
150
—
15
Reference:  Test Methods for Evaluating Solid Waste:  SW-846.

a    The  wavelengths  listed  are  recommended because  of their
     sensitivity and  overall acceptance.  Other wavelengths may  be
     substituted if they can provide  the needed sensitivity and  are
     treated with the same corrective techniques  for spectral
     interference.  In time, other  elements may be added as more
     information becomes available  and as required.

b    The  estimated instrumental  detection limits  are shown.   They are
     given as  a  guide for an instrumental limit.  The actual  method
     detection limits are sample dependent and may vary  as the sample
     matrix varies.

c    EPA's Environmental Monitoring Support Laboratory detection
     limit ranges.

d    Highly dependent on operating  conditions and plasma position.

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                            TABLE 3.5

    ATOMIC  ABSORPTION FLAME AND FURNACE INSTRUMENTAL  DETECTION
          AND SENSITIVITY LIMITS FOR WASTEWATER SAMPLES
                     Direct Aspiration
Metal
Detection Limit
   (mg/L)
Sensitivity
  (mg/L)
Furnace Procedure3'0
 Detection Limit
     (ug/L)
Aluminum
Antimony
Arsenic .
Barium(p)
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercurya
Molybdenum(p)
Nickel(p)
Potassium
Selenium6
Silver
Sodium
Thallium
Tin
Vanadium (p)
Zinc
0.1
0.2
'0.002
0.1
0.005
0.005
0.01
0.05
0.05
0.02
0.03
0.1
0.001
0.01
0.0002
0.1
0.04
0.01
0.002
0.01
0.002
0.1

0.2

1
0.5
0.4
0.025
0.025 "
0.08
0.25
0.2
0.1
0.12
0.5
'0.007
0.05
—
0.4
0.15
0.04
—
0.06
0.015
0.5
0.8
0.8
0.005
__
3
1
'
0.2
0.1
—
1
1
—
—
1
—
—
—
1
—
—
2
—
—
1
4 —
4
0.02—
Reference:  Test Methods for Evaluating Solid Waste:  SW-846.

NOTE:  The symbol  (p)  indicates the use of pyrolytic graphite
   with the furnace procedure.

a   For furnace sensitivity values, consult instrument operating
    manual.

b   Gaseous hydride method.

c   The listed furnace values are those expected when using a
    20-uL injection and normal gas flow, except in the cases of
    arsenic and selenium, where gas interrupt is used.
    Cold vapor technique.

-------
interferences, the detection limits for typical sludge samples
will be somewhat higher.

Mercury Analysis
     The physical-chemical characteristics of mercury are not
amenaible to digestion by the generally recommended technique,
Method 3050.  For the determination of total mercury (organic and
inorganic) in soils, sediments, bottom deposits, and sludge
material, EPA recommends using Method 74/1, a cold-vapor atomic
absorption spectrometry.  This method appears in the EPA manual
"Test Methods for Evaluating Solid Waste."  (SW-846, Nov. 1986,
3rd Ed., pp. 7471-1,10).  Prior to analysis, the solid or
semi-solid samples must be prepared according to the procedures
discussed in this method.  The typical detection limit for this
method is 0.0002 mg/L.

Antimony and Silver Analysis
     The procedures for preparation of antimony and silver
samples are given in Method 3005.  Method 3005, a soft digestion,
is presently the only digestion procedure recommended for
antimony.  It yields better recoveries than either Method 3010 or
3050.  There is no hard digestion for antimony at this time
(SW-846, Nov. 1986, 3rd Ed., p. 7041-2).  Samples prepared by
Method 3005 are amenable to determination by either ICAP Method
6010 or the atomic absorption furnace technique, Method 7041
(SW-846, 3rd Ed. - see pp 7041-1 through 7041-4).  Detection
limits for Method 7041 are 3 ug/L for antimony and 10 mg/1 for
silver.
                               3-17

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3.3  ORGANICS

     The evolution of analytical techniques for organic
contaminants has involved a number of modifications to a basic
method in order to widen potential applications.  Because the
instrumentation is complex and the number of possible analytes is
large, quality control is difficult to monitor and several
analytical techniques are required.  As with analyses for metals
and other elements, the organic-rich complex matrices character-
istic of sewage sludges often mean that analyte
extraction/isolation procedures play a significant role in the
reliability of the resultant analytical data.

3.3.1  Overview of Analyte Extraction arid Isolation
     For a number of reasons, EPA has focused regulatory
attention on two categories of contaminants:  volatile organics
and semi-volatile organics.  While the classification of these
groups is founded upon inherent physical/chemical properties,
extraction and isolation techniques are the functional basis for
the distinction.

Volatile Organics
     Two methods are available for extraction and isolation of
volatile organics in aqueous and solid matrices:  headspace
techniques and purge and trap techniques.  Several versions of
these procedures have been sanctioned by regulatory agencies
and/or developed for use in specific applications.  For POTW
sludge sampling and analysis,fEPA recommends two analytical
methods (1624C, 624-S) which both extract via purge and trap (see
Section 3.3.2).
                               3-18

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     Purge and trap requires moderate sample preparation.  The
method relies upon a stripping process in which an inert gas is
bubbled through the sample to remove the volatile organics.  The
volatilized organics are transferred from the'aqueous/solid phase
to the gaseous phase and subsequently trapped on a solid
adsorbent column.  The adsorbent column is then heated and the
trapped organics are thermally desorbed and swept into the
analytical instrument.

Semi-volatile Organics
     The first step in all procedures for determination of semi-
volatile organics is solvent extraction.  (Note:  For extraction
procedures recommended by EPA for sludge analysis see Section
3.3.2!).  The sample material is mixed and agitated with a
solvent, causing the organic analytes to be preferentially
partitioned into the solvent phase.  Extractions are typically
performed at both acidic and basic pH ranges to facilitate
extraction of ionizable organics.  Modifications to the
extraction method are usually based upon the manner in which the
sample-solvent mixture is agitated and post-extraction cleanup
procedures.

     The organic solvent used most frequently for extraction of
semi-volatile analytes is methylene chloride, either singly or in
combination with a more polar solvent.  Extraction techniques
which are applicable to sludge and solid matrices include:

     o   Sonication extraction
     o   Continuous liquid-liquid extractors
     o   Soxhlet extraction
     o   Mechanical agitation (shaker table, homogenization, or
         wrist-action shaker).
                               3-19

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Sonication relies on the mechanical energy developed from
ultra-sonic devices to affect agitation and solvent-solid
contact.  The best approach involves the use of a sonication horn
which is immersed into the solvent-sample mixture, rather than a
sonication bath.  This technique has also been proven effective
in sludge and sediment applications.

     Continuous liquid-liquid extractors and Soxhlet extractors
employ the same basic principle of operation.  The extraction
solvent is distilled from a reservoir, condensed above the sample
material, and subsequently rains down through the sample.  The
distillation-condensation process continues until a volume of
solvent has collected sufficient force to establish a siphon, at
which point the extraction solvent is siphoned back into the
reservoir.  The cycle is repeated with freshly distilled solvent
and is generally allowed to occur for 12-24 hours.  The
continuous liquid-liquid extraction procedure can only be used on
low solids «5%) sludges, while the Soxhlet technique is most
useful for materials with low water content.

     A variety of mechanical agitation techniques have been used
for extractable organics determinations, including homogen-
ization, wrist-action shakers and platform shakers (shaker
tables).  The objective of each technique is to maximize the
contact between the extraction solvent and the solid particles.
Wrist-action and platform shakers have both proven adequate, with
wrist-action shakers generally preferable for smaller sample
containers and platform shakers preferable for larger extraction
vessels.  Homogenization relies on agitation of the solvent-solid
mixture, rather than agitation of the entire extraction vessel.
This technique has been used quite successfully in sludge
applications as a result of its superior agitation.  However,
                               3-20

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sand, a fairly common constituent of sewage sludge, literally
chews up high speed homogenizers.

     As a result of the complexity of sludge matrices,
fractionation and/or cleanup procedures are often required after
sample extraction to minimize interference.  The basic concept
used in virtually all cleanup techniques is selective adsorption
of the interfering components.  Although a variety of cleanup
procedures have been developed for specific analytes, the
techniques commonly employed for the listed applications include:

     o   Gel permeation resins - broad spectrum cleanup and
         higher molecular weight biogenic organics
     o   Activated carbon - fractionation and general purpose
         cleanup
     o   Alumina adsorbent - inorganic adsorbent
     o   Florisil adsorbent - inorganic adsorbent
     o   Silica gel adsorbent - inorganic adsorbent
     o   Copper and mercury - removal of sulfur-containing
         compounds.

Cleanup procedures can be used individually or in combination
with other procedures, depending upon the need of the particular
application and the complexity of the sample.

     For more detail regarding extraction and isolation
techniques, consult the references cited in 40 CFR Part 136,
"Guidelines for Establishing Test Procedures for the Analysis of
Pollutants."
                               3-21

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3.3.2  Recommended Analytical Techniques for Organics

     For determining concentrations of organic pollutants in
sludge, EPA recommends two methods designed for qualitative and
quantitative analysis of municipal and industrial wastewater
treatment sludges:

     o  Volatile Organics - 624-s (EPA 1984b) or 1624C (EPA
         1988a)
     o  Semi-Volatile Organics - 625-S (EPA 1984b) or 1625C (EPA
         1988a)

Each of these two methods employ gas chromatography/mass
spectrometry (GC/MS).

     GC/MS is a combination of two microanalytical techniques:
gas chromatography (a separation technique) and mass spectrometry
(an identification technique).  A sample aliquot is prepared for
extraction, extracted, then introduced to the GC/MS system.  The
extract is vaporized quickly at an elevated temperature and
carried by an inert gas (mobile phase) through a coated column
(stationary phase).  Separation of the extract components is
effected by their differential partitioning between stationary
and mobile phases.  The separated components exit the column and
enter the mass spectrometer (MS) where they are decomposed to
specific unimolecular species.  The manner in which a component
fragments is characteristic of that component and is the basis
for identification.  The MS detector quantifies a compound by
responding with a signal proportional to the detected amount of
the compound.

     The GC/MS system is calibrated by measuring signal response
to three to five analyte standard solutions of various
concentrations (e.g., 20-160 ng/ml).  The solutions are carefully
                               3-22

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prepared mixtures of pollutants suspected to be present in the
sample, as well as a few labeled pollutant analogs known as
internal standards.  The accumulated measurements form an
instrument response curve.   Samples are spiked with the same
internal standards at a fixed concentration immediately prior to
analysis.  If the MS detects any sample-originated pollutants,
the generated signal for each pollutant is measured against both
the internal standard and the response curve.

     GC/MS analysis affords several advantages over other
techniques:

     o   Provides qualitative and quantitative information about
         a wide range of organic compounds.
     o   Confirms specific information from a small sample size.
     o   Produces a spectrum with a fragmentation pattern, or
         fingerprint, which can be used to identify an unknown.

3.3.2.1  Methods 1624C and 1625C
     Methods 1624C and 1625C are draft methods for analyzing
volatile organics  (Method 1624C) and base/neutral, non and semi-
volatile organics  (Method 1625C) in sludge.  These methods were
developed by the USEPA Office of Water Industrial Technology
Division, and are derived from previous methods 1624 and 1625
(see 40 CFR Part 136) for analyzing wastewaters.

     The 1624C/1625C (and 1624/1625) test procedures are isotope
dilution techniques.  In conventional GC/MS, up to six internal
standards are used to quantify the response of perhaps several
dozen analytes.  Isotope dilution GC/MS employs stable,
isotopically labeled analogs of the compounds of interest, which
is analogous to providing a separate internal standard for each
analyte.  The result is that isotope dilution GC/MS is sensitive
                               3-23

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to even minute contaminant concentrations.   Methods 1624C/1625C
and 1624/1625 are similar in this respect but differ in sample
preparation.

     Method 1624C sample preparation for sludge samples consists
of the following three routes, depending on the percent (%)
solids content of the sludge.  If the solids content is less than
one percent, stable isotopically labeled analogs of the compounds
of interest are added to a 5 gram sample and the sample is purged
in a chamber designed for soil or water samples.  If the solids
content is 30 percent or less, the sample is diluted to one
percent solids with reagent water, and labeled compounds are
added to a 5 gram aliquot of the sludge/water mixture.   The
mixture is then purged.  If the solids content is greater than 30
percent, five ml of reagent water and the labeled compounds are
added to a 5 gram aliquot of sample.  The mixture is then purged.
     Method 1625c sample preparation for sludge samples consists
of the following three routes, depending on the percent (%)
solids content of the sludge.  If the solids content is less than
one percent, a one liter sample is extracted with methylene
chloride using continuous extraction techniques.  If the solids
content is 30 percent or less, the sample is diluted to one
percent solids with reagent water, homogenized ultrasonically,
and extracted.  If the solids content is greater than 30 percent,
the sample is extracted using ultrasonic techniques.  Each
extract is subjected to a gel permeation chromatography (GPC)
cleanup.

     These methods are currently undergoing revision at EPA's
Environmental Monitoring and Support Laboratory for problems
relating to the sample preparation portions.  They are the
                               3-24

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methods used in the National Sewage Sludge Survey (which EPA is
conducting to provide a current data base to be used to set
pollutant limits, evaluate risks of use and disposal practices,
and evaluate the impacts of the proposed rule) and also are
discussed in the 40 CFR Part 503 regulation proposed on February
6, 1989 and now out for comment.  Depending on the results of the
comment period, the isotope dilution methods may be exclusively
required for priority pollutant organics analysis when 40 CFR
Part 503 is finalized.

3.3.2.2  Methods 624-S and 625-S
     Methods 624-S and 625-S are existing methods for the
measurement of organic priority pollutants in sludges.  These
test procedures were derived from previously developed methods
624 and 625 for analyzing wastewaters (see 40 CFR Part 136).  The
624-S/625-S techniques are conventional GC/MS and operate as
described in Section 3.3.2.  Method 624-S is used to analyze for
volatile organic compounds.  Method 625-S is used for
semi-volatile or nonvolatile organics.

     In Method 624-S, an inert gas is bubbled through a 10-ml
sludge aliquot contained in a purging chamber at ambient
temperature.  The purgeable compounds are transferred.from the
aqueous phase to the vapor phase.  The vapor is carried through a
sorbent column where the purgeables are trapped.  After purging
is completed, the sorbent column is heated and backflushed with
the inert gas to desorb the purgeables into a gas chromatographic
column.  The gas chromatograph is temperature programmed to
separate the purgeables which are then detected with a mass
spectrometer.

     Method 625-S uses repetitive solvent extraction  (see section
3.3.1) aided by a high-speed homogenizer.  The extract is
                               3-25

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separated by centrifugation and removed with a pipette or
syringe.  Extracts containing base/neutral compounds are cleaned
by silica gel or florisil chromatography or by gel permeation
chromatography (GPC).  Extracts containing the acidic compounds
are cleaned by GPC.  The organic priority pollutants are
determined in the cleaned extracts by capillary column or packed
column GC/MS.  Option A, i.e., extract cleanup by silica gel or
florisil chromatography and analysis by capillary column GC/MS
(HRGC/MS) is preferred since HRGC/MS allows easier data
interpretation.

     While Methods 1624C/1625C provide lower detection limits, in
some cases, than Methods 624-S/625-S, these methods are also more
costly.  Presently, Methods 1624C/1.625C cost about $2,200-$2,400
per sample, which is approximately $200-$400 more than a similar
analysis by Methods 624-S/625-S.  The extra cost reflects the
Method 1634/1635 isotope spikes and approximately two weeks of
work necessary to prepare additional spectral libraries.

     Neither Methods 624-S/625-S or Methods 1624C/1625C detect
pesticides at very low concentrations.  Without megabore column
analysis, which may cost an additional $1,000, none of these
methods will do better than the detection limits, 20-50 ppb.  For
some highly mixed pesticides such as chlordane, these methods can
only detect 200-300 ppb.  At this time, EPA is not recommending
megabore column pesticide analysis nationally.  However, in
situations where lower detection limits are crucial such as in
PCS or pesticide analysis, megabore column analysis is necessary.

3.4  PATHOGENIC MICROORGANISMS
     A pathogen or pathogenic agent is any biological species
that can cause disease in the host organism (primarily humans).
These organisms fall into four broad categories:  viruses,
                               3-26

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bacteria, parasites, and fungi.  From these categories, species
commonly found in sewage sludge include fecal colifoons, fecal
streptococci, salmonella, and ascaris (helminth).   Wastewater
sludge disinfection, the destruction or inactivation of
pathogenic organisms in the sludge, is carried out to minimize
public health concerns regarding these and other microbial
agents.

     The 40 CFR Part 257 regulations issued under joint authority
of Subtitle D of the Resource Conservation and Recovery Act
(RCRA) and Section 405(d) of the Clean Water Act establish
requirements for the disposal of solid waste which include
pathogens in sewage sludge.  The regulations (40 CFR Part
257.3-6) require that sewage sludges applied to the land surface
or incorporated into the soil be treated by a Process to
Significantly Reduce Pathogens (PSRP).  Public access must be
controlled for at least twelve months after sludge applications
and grazing by animals whose products are consumed by humans must
be prevented for at least one month after application.  Treatment
by a Process to Further Reduce Pathogens (PFRP) is required for
sewage sludge applied to the land surface or incorporated into
the soil if crops for direct human consumption are grown within
eighteen months after application, if the edible portion of the
crop will touch the sludge.

     Rather than requiring a specific reduction or concentration
for given pathogens, the process-based regulation (see Appendix
II of 40 CFR Part 257)  describes and sets numerical requirements
for unit processes and operating conditions that qualify as PSRP
and PFRP (e.g., criteria,for process time and temperature and for
volatile solids reduction).  Thus permit compliance is based on
meeting process requirements, not pathogen reduction per se.
Appendix II of 40 CFR Part 257 allows methods or operating
                               3-27

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conditions other than those listed under PSRP or PFRP if
pathogens and vector attraction are reduced commensurate with the
reductions attainable from listed methods.  Appendix II (of 40
CFR Part 257) does not prescribe the operation mode (i.e., batch
or continuous) for digesters.   The regulation also does not
specify a method for calculating volatile solids reduction.  For
a comprehensive discussion of the ways that volatile solids
reduction may be calculated and their limitations, refer to
Appendix B of this guidance document.

     Although the 40 CFR Part 257 regulations are based on
specific processes rather than on meeting specific pathogen
reduction levels, the regulations do provide that other processes
"may be acceptable if pathogens are reduced to an extent
equivalent to the listed processes."  In order to provide
guidance on the equivalence of these other methods EPA has a
panel of experts, the Pathogen Equivalency Committee (PEC), which
evaluates the acceptability/of the process based on the level of
pathogen reduction, as determined by standardized analytical
tests.  For more comprehensive information on pathogen and
guidance on whether alternative processes provide equivalent
levels of pathogen reduction consult the draft "Guidance for
Controlling Pathogens in Municipal Wastewater -Sludge" PEC/EPA May
1989  (to be finalized July/August 1989).

     Sampling techniques for determining pathogens in sewage
sludge are no different than for other tests except that no
preservatives are used.  In the absence of definitive sludge
methods for determining bacteria concentrations, modified
standard wastewater methods are often utilized.  The analytical
methods for analysis of pathogens and indicator organisms are
provided in Table 3.6.  Unfortunately no standardized methods
exist for parasitic determinations.
                               3-28

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                                         TABLE  3.6

ANALYTICAL TECHNIQUES FOR DETERMINATION OF PATHOGENIC MICROORGANISMS IN SEWAGE SLUDGE
                                             |

Pathogen         Preparation Technique                 Culture Media       Reference

Fecal Coliform            ^^'                   ^^             A(908 or 909)

Fecal streptococcus/
  enterococci             -—                              	             A(910A) or B

E. coli          Centrifugation and filtration  M-PC broth membrane        A(912E)
                                                       filters

Salmonella sp.   Filtration                     Brilliant green-xylose     A(912C.l) or C
                                               .lysine desoxycholate agars

Animal Viruses   Centrifugation, elutriation,   Tissue culture             D
                 filtration, and flocculation

Helminth Ova     Filtration                                	             A(917) or E

Protozoa	Filtration			  A(917) or E

A)   APHA-AWWA-WPCF Standard Methods for the Examination of Water and Wastewater. 16th Ed.

B)   Slantely, L.W. and Bartley, "Numbers of enterococci in water, sewage, and feces
     determined by the membrane filter technique with an improved medium", J.  Bacteriology
     14: 591-595 (1957).

C)   Kenner, B.A., and Clark, "Detection and enumeration of Salmonella and Pseudomonas
     aeruginosa", J. Water Pollution Control Federation 4£(9): 2163-2171 (1974).

D)   "The Manual of Methods for Virology", EPA/600/4-84/013 (February 1984) as revised.

E)   Fox, J.C., Fitzgerald, and Lue-Hing, "Sewage Organisms:   A Color Atlas",  Lewis
     Publishers, Chelsea, Michigan (1981).

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     The effectiveness of many PSRPs and PFRPs .for reducing
pathogens can be estimated by measuring the effects on fecal
indicator organism densities (e.g., fecal coliform and/or fecal
streptococcus).  These tests are less expensive and easier to run
than tests for specific pathogens and also provide good control
data.
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               4.  QUALITY ASSURANCE/QUALITY CONTROL


     An essential part of a sampling and analysis program

 includes a well designed quality assurance/quality control

 (QA/QC) program.  The extent of the QA/QC program should mirror

 the  intent and purpose of the sampling effort.  It should be

 noted that the facility is ultimately responsible for the quality

 of the data even if a contractor is used.  Therefore, it behooves

 the  POTW to have a good QA/QC program.


     If the purpose of the sampling and analysis program is to
 determine compliance with permit conditions, or to provide

 critical data  for making a major cost decision, then the QA/QC

 program should be extensive and be able to demonstrate the

 precision, accuracy, representativeness, comparability and

 completeness of the data.  The determination of these QA/QC

.parameters and their definitions are as follows:


     o    QA is an overall program which guarantees the quality
          of the product.  It includes a QC auditing process to
          prevent future defects.  QA is synonymous with process
          control, continuous improvement and prevention of poor
          quality.  QC is the examination of the product to
          determine if it meets the specifications of the QA
          program.  QC is part of the overall QA program.  QC is
          synonymous with appraisal after the fact.  An example
          of QC is that lab duplicate results must be within a
          certain percentage of each other or else the whole
          batch must be redone.

     o    Laboratory QA includes prevention of data contamination
          during laboratory procedures.  Contamination may be due
          to various other tests that are run in the lab at any
          given time.  In order to assure that any sample
          contamination that does occur does not contaminate lab
          data, a lab QA sample, usually a deionized water
          "blank" (or other "clean" appropriate material), is run
          along with the actual field samples.  Lab QA also
          includes doing duplicates and spikes of the actual
          samples.  Field QA serves the same purpose, to prevent
          data from being erroneous.  However, it is virtually
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impossible to prevent contamination of the samples
since the sampling environment is not controllable.
Therefore, the field blanks are subject to the same
conditions as the samples, i.e., the containers are
exposed to the environment as long as the sample
containers are open, the sample and field "blank" are
transported together.

Accuracy, which is closeness to actual values, of all
sample testing and analyses should be evaluated at a
minimum frequency of 5 percent of the samples tested
(i.e., at least one in every 20 samples), using spiked
samples.  Accuracy is calculated from the known and
analytically derived values of spiked parameters, and
expressed as percent recovery.  The accuracy required
in the quality assurance program for tne analyses is
specified in each of the EPA methods (e.g.,  EPA 600 or
1600" Series or EPA Methods for Chemical Analysis of
Water and Wastes).

Precision, which is repeatability of results, of sample
analyses should be evaluated at a minimum frequency of
5 percent (i.e., at least one in every 20 samples),
using spiked samples in duplicate.  Precision is
calculated from the analytical results of the spiked
analytes in each set of duplicate samples, and
expressed as percent relative standard deviation.  The
precision required in the quality assurance program for
the analyses is specified in each of the EPA Methods
(e.g., EPA 600 or 1600 series or EPA Methods for
Chemical Analysis of Water and Wastes).

Completeness is calculated as the ratio of valid
measurements obtained to the number of valid
measurements needed to reach a predefined statistical
level of confidence in the resulting data.
Completeness is determined and evaluated on the basis
of data sets for each specific measurement process.
Data are considered to be valid if both the accuracy
and precision of the measurements meet the data quality
objective (i.e., accuracy, precision, and compliance
with analysis method protocol).

All sampling should be performed using methods,
procedures, and controls that ensure the collection of
representative samples which thus ensures that the
analytical results are representative of the media and
the conditions being measured.
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          Comparability is a more qualitative QA measurement.
          All analytical data must be calculated and reported in
          units consistent with those specified in the applicable
          permit.  Previously developed data generated for each
          facility about to be inspected is reviewed to ensure
          that no difficulties of data comparability will be
          encountered by following the specifications of the
          permit.  If no previous data exist and the permit
          requirements are incomplete or ambiguous, data should
          be reported in the standard units prescribed in the
          appropriate EPA Methods (e.g., EPA 600 or 1600 series
          or EPA Methods for Chemical Analysis of Water and
          Wastes).
These QA/QC procedures are necessary for ensuring data quality.

On the other hand, if the purpose of the sampling effort is to
monitor plant performance for routine operation and maintenance

(O&M) decisions, a simplified QA program that includes sample
replicates and a field blank might suffice.


     Sludge sampling and analysis programs for determining

compliance with permit conditions should include a written QA

Plan.  EPA guidance for the development of a QA Program (EPA

Quality Assurance Project Plans (QAPP), 1983) identifies 16

elements which should be addressed in a QA plan:


     Title Page

     Table of contents

     Project Description

     Project Organization and Responsibility

     QA Objectives for Measurement Data in Terms of Precision,
          Accuracy, Completeness, Representativeness, and
          Comparability

     Sampling Procedures and Frequency

     Sample Custody

     Calibration Procedures and Frequency
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     Analytical Procedures
     Data Reduction, Validation and Reporting
     Internal Quality Control Checks
     Performance and System Audits
     Preventive Maintenance
     Specific Routine Procedures Used to Assess Data Precision,
          Accuracy and Completeness
     Corrective Action
     Quality Assurance Reports to Management

     In preparing a QAPP, the QA parameters and specifications of
the analytical program should be dictated by the analytical
parameters.  The QA parameters are specified in each analytical
protocol.  There are situations (particularly for enforcement
actions) in which more stringent protocols will be desired.

     In preparing the QA plans, the collection of field blanks
(blanks to reflect sample handling effects) and' sample replicates
should be addressed.  At a minimum, field blanks should be
collected every day that sampling is performed.  Field blanks
should be prepared at the beginning of each sampling event, at
each discrete sampling site, by pouring American Society for
Testing and Materials (ASTM) Type II reagent water into prepared
sample bottles.  These sample bottles are randomly selected from
the supply of prepared sample bottles; a sample container should
be selected that is appropriate for each type of analysis for
which environmental samples are being collected (see Table 2.4).
The field blanks should be handled and analyzed in the same
manner as environmental samples.  Because field blanks and
environmental samples are collected under the same conditions,
field blanks analyses should be used to indicate the presence of
                               4-4

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external contaminants that may have been introduced into samples
during collection.

     One field replicate for every 20 samples or less should be
collected at a preselected POTW monitoring point.  Field
replicates should be collected at the same time and in the same
manner as the other environmental samples.  Results of the field
replicate analyses should be used primarily to assess the
precision of the field sampling methods.

     In preparing and evaluating the analytical report, attention
                               o
should be given to the data quality, and the impact of both the
sampling and analysis data quality to the overall interpretation
of the analytical results.  Both the data from the field QA
samples and the laboratory QA samples should be evaluated for the
presence of contaminants.  Additionally, statistical procedures
should be used for the determination of precision, accuracy and
completeness.  The QAPP 1983 document provides a description of
the statistical procedures and their applications.  All reports
of analytical data should contain a separate section which
assesses the quality of the reported data.

     The sample procedures and frequency section of the quality
assurance plans should address, among other elements, sample
holding times, sample preservation procedures, and sample
chairi-of-custody.  Maximum sample holding times are presented in
Table 2.4.  Section 2.5.3 addresses sample preparation.  Section
2.7.2 addresses sample chain-of-custody.

     The section of the quality assurance plan on internal
quality control checks specifically discuss how the following
activities will be addressed:
                               4-5

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Organic Priority Pollutants
     o    Instrument tuning and calibration
     o    Method blank analysis
     o    Surrogate spike analysis
     o    Matrix spike/matrix spike duplicate analysis
     o    Internal standards analysis

Inorganic Priority Pollutants
     o    Initial calibration verification
     o    Continuing calibration verification
     o    Instrument response and linearity verification
     o    Calibration and preparation blank analyses
     o    Interference check sample analyses
     o    Spike sample analyses
     o    Duplicate sample analyses
     o    Quality control sample analyses
     o    Serial dilution analyses (if applicable)
     o    Instrument detection limit determination
     o    Method of standard additions application.
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                5.  SAMPLING AND ANALYTICAL COSTS

     The cost.of carrying out a sludge sampling program can vary
depending on the number and type of samples, parameters analyzed,
and whether analytical services are contracted out.  The
following discussion examines sampling and analytical costs as of
April 1989.

5.1  MANPOWER REQUIREMENTS
     Manpower requirements fall into two categories:  (1)
supervisory and program development, and (2) sampling/analytical.
All sampling programs should be designed and supervised by
qualified personnel.  Developmental and supervisory needs will
vary according to the following factors:

     o    Type and number of samples
     o    Number of streams to be sampled
     o    Number of facilities/locations
     o    Availability of suitable sample points
     o    Parameters to be analyzed
     o    Experience and qualifications of field and laboratory
          personnel.

The number of factors influencing supervisory needs makes
estimating average costs for these needs impractical.  Costs will
vary according to the hours needed for each program and according
to the salary range of qualified personnel within a given
organization.

     Sampling manpower needs will also vary widely depending on
the conditions listed above.  For 24-hour composite sampling, a
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minimum of two shifts (more likely three) are required.  The

actual, time spent sampling during the shifts will depend on how

frequently grab samples are collected (one per hour or once every

4 hours) during the 24-hour sampling period.  In addition to the

manpower required to actually collect the sample, additional time

is required for sample preparation and handling.  On-the-job

training is generally acceptable for sampling procedures.


     Estimates of some of these needs are presented below:


                            TABLE 5.1
                                                         *
	Activity	Manpower	
     o
Automatic Sampler Setup1       0.5-4  manhours
     o    Sample Container              2-15  man-minutes
              Preparation2                      sample

     o    Sample Documentation3         2-15  man-minutes
                                                sample

     o    Sample Handling4              2-60  man-minutes
                                                sample


1  Depending on sample point characteristics.
2  Depending on parameter.
3  Depending on parameter, ultimate data use and number of points
   sampled simultaneously.
4  Depending on parameters sampled and whether samples are
   analyzed on site, are delivered or shipped.


5.2  IN-HOUSE ANALYTICAL COSTS

     If any analytical work is done in-house, manpower,

equipment/facility and operating (i.e., electrical, chemical

supplies, etc.) costs will be  incurred.  Real costs will vary
according to what extent the analytical load imposed by the
sludge sampling is marginal to the laboratory's operational
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capacity. . Two extremes serve as examples of this cost
variability.

     A plant electing to do in-house analysis which has no
laboratory would need to make a sizable expenditure for an
adequate facility and the necessary analytical equipment and
supplies.  In addition, qualified (B.S. Chemistry or equivalent)
laboratory personnel must be put on the payroll.  Given these
circumstances, it would generally not be practical to do in-house
analysis.  Instead, it is likely that this plant would contract
out for analytical services.

     A second plant, conducting a similar sludge sampling
program, also elects to do all related analytical work in-house.
This plant, however, has an analytical laboratory in place which
is capable of performing all analyses required.  In addition, the
laboratory is presently operating below capacity.  The additional
load imposed by the sludge sampling program will not require any
capital expenditure, and will require little, if any, additional
laboratory manpower (any additional manpower needs can be
accommodated by limited overtime rather than new employee hires).
In the case of this plant, in-house analysis for a sludge
sampling program can be accomplished at a very low real cost.

     Because of the wide range of real costs possible for
sampling and in-house analytical work, no attempt is made herein
to quantify these costs on a dollars per sample basis.  Rather,
each sampling program must be analyzed in light of applicable
salary scales, sampling program complexity and in-house
analytical capabilities.
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5.3  CONTRACT ANALYTICAL COSTS
     Many sludge sampling programs, particularly those conducted
by small municipalities or authorities, will utilize contract
laboratories for analytical work.  In contrast to sampling costs,
which vary greatly due to a wide variety of factors, contract
analytical costs fall within a relatively narrow range.  Table
5.2 presents typical analytical costs for parameters commonly run
on sludge samples.  These cost estimates were obtained in a March
1988 and 1989 telephone survey of analytical laboratories.

     Two factors must be considered in estimating contract
analytical costs for sludge sampling programs.  The first is the
need, depending on parameters, for additional preparation of
sludge samples prior to analysis.  Many laboratories charge an
additional fee for this preparation, which can be as much as
$100, depending on the parameters to be run.

     The second factor impacting analytical costs is the practice
by most laboratories of offering discounts on per sample prices
for multiple sample analysis.  These discounts vary from .
laboratory to laboratory, and can be substantial depending on the
number of samples involved.  Of particular importance is the
number of samples being received simultaneously by the laboratory
(i.e., a greater discount will typically be offered for 10 sam-
ples if all are to be analyzed at one time rather than if one is
to be delivered to the lab each week for 10 weeks).

5.4  SAMPLING EQUIPMENT COSTS
     The cost of sampling equipment and containers is typically a
relatively small fraction of the overall cost of a sludge
sampling program.  In general, the manual collection methods used
for sludge sampling require only simple, relatively inexpensive
                                    5-4

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                           TABLE 5.2

              TYPICAL CONTRACT ANALYTICAL COSTS FOR
               COMMONLY ANALYZED SLUDGE PARAMETERS
                 ANALYSIS COST RANGE ($/SAMPLE)
               Washington   District of
                  State      Columbia   California  Massachusetts
Priority Pollutants
Organics Methods:
1624C/1625C
Office of Solid
Waste #8240
624-S/625-S
Acid Fraction Only
Base Neutral Only
Metals;
ICAP or AAS
Others ;
Cyanide
Phenols
Total PCBs
Pesticides

Total for Priority

Other Non Priority
Oil & Grease
" total grav.
" HC "
11 HC & tot "
" IR method
Ammonia, as N
Tot Kjeldahl N
Tot Suspend Sol
Tot % Solids
Tot Phosphorus
Phosphate
Potassium
Tot Org Hal ides
EP Toxic ity
extraction
8 metals
2 pest.
4 herb.
TOTAL EP

2200-2400


1800-2200
N/A
N/A

25-200/metal

20-30
20-30
60-150


250

425
N/A
N/A

240/U3)

75
75
200
included
in
Scan without Dioxin
2225-5210
Pollutants
15-25




10-20
10-20
10-20
10-20
10-20
10-50
20-30
50-100

N/A



$ 420
above

1265















100
140
100
150
$490




550
225
325

290/U3)

60
50
175
150


1275


60
80
130
100
35
35
15
15
35
35
15
80

75
185
150
175
$585

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equipment..  The following paragraphs highlight the primary

equipment cost items in a typical sludge sampling program.
          Sample Containers -  Sample container costs are related
          to:  (1) the number of containers needed, and (2)  the
          type of container needed, depending on parameter(s)  to
          be analyzed.  The following are typical per-container
          prices for some commonly used containers:

          Container                size           Approx. Price

          Teflon                   1 liter        $ 35 - 40
          Graduated Glass          1 liter        $  3-4
             (w/Tefion-lined cap)
          Polypropylene            1 liter        $  2
          Polypropylene            0.5 liter      $  1.50
          Polypropylene            10 liter       $ 15
          Glass                    0.5 liter      $ <1 - 2
             (w/TefIon lined cap)

          As with analytical costs, suppliers of containers  often
          offer substantial discounts for volume purchases.

          Automatic Samplers - In most sludge sampling programs
          the use of automatic sampling equipment will be
          precluded due to sample characteristics.  If automatic
          sampling is utilized in a given sampling program,
          automatic sampler costs will typically constitute  the
          majority of sampling equipment costs.  Portable,
          battery-powered peristaltic-type samplers typically
          cost from $1000 to $3000, depending on features such as
          computerized controls, etc.  Pneumatically operated
          plunger-type samplers will vary in price according to
          application and capacity.

          Manual Sampling Equipment -  In general, equipment
          costs for manual sludge sampling are minimal.
          Stainless steel pitchers (2 liter), which are useful
          for sampling from either a tap or an open channel  flow,
          are available for approximately $20.  Polypropylene
          pitchers typically cost about 1/2 of the price of
          stainless steel.  Stainless steel scoops used for
          sludge cake sampling cost approximately $40  (depending
          on size), while aluminum scoops of similar size are
          available for less than $10.

          Preservatives -  Reagent grade chemicals should be used
          as preservatives.  Since each sample will typically
                                    5-6

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          require very small amounts of preservatives, cost on a
          per sample basis is negligible.

5.5  OPPORTUNITIES FOR COST SAVINGS
     To provide a representation of sludge quality over a fixed
duration, sewage sludge can be composited (i.e.  mixed), reducing
the number of samples to be analyzed.  In light  of the high costs
associated with analysis of priority pollutant organics in sewage
sludge, compositing samples provides an opportunity to
substantially lower analytical costs.  Field compositing is not
an appropriate technique to use when the sample  will be analyzed
for volatile components.  Lab personnel can composite grab
samples in the lab.

     When interested in daily variation in sludge constituents, a
POTW can collect and analyze 24-hour composite samples, each
consisting of six or more grab.samples.  This represents a
significant cost savings when compared to separately analyzing
many individual, non-composited samples.  Smaller POTWs, with
less variation in sludge quality, may elect to composite samples
over several days as opposed to 24-hour composites.  The
suitability of a multi-day compositing procedure will depend upon
whether the specific sludge constituent can be adequately
preserved in the sludge sample.   Table 2.3 shows the recommended
preservatives and maximum sample holding times for organic and
metal pollutants.

     Another way to reduce costs would be to sample more
frequently for parameters that are relatively inexpensive to
analyze such as metals, nitrogen, phosphorus, and potassium, and
to test for organic pollutants (expensive) less frequently, so
long as some data are available indicating that the levels of
organic contaminants in the sludge are acceptable.
                                    5-7

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                        6.   REFERENCES
APHA-AWWA-WPCF.   1976.  "Standard Methods for the Examination of
Water and Wastewater".  Washington, B.C.:  APHA-AWWA-WPCF.

Black, C.A. (ed.).  1965.   "Methods of Soil Analysis, Agronomy
Monograph No.  9."  Madison, Wisconsin:  American Society of
Agronomy.

Colby, Bruce N. , and Ryan, Philip W.  1986.  "Initial Evaluation
of Methods 1634 and 1635 for the Analysis of Municipal Wastewater
Treatment Sludges by Isotope Dilution GC/MS".  Washington,  B.C.:
U.S. Environmental Protection Agency, Office of Water Regulations
and Standards.

"Criteria for Classification of Solid Waste Disposal Facilities
and Practices," 40 CFR Part 257.  Washington, B.C.:  National
Archives and Records Administration, Office of the Federal
Register.

EPA.  1974.  "Process Design Manual for Sludge Treatment and
Disposal", EPA625/1-74-006.  Washington, D.C.:  U.S.
Environmental Protection Agency, Office of Technology Transfer.

EPA.  1976.  "Analytical Methods for Trace Metals",
EPA-430/1-76-002.  Cincinnati, OH:  U.S.. Environmental Protection
Agency, National Training and Operational Technology Center.

EPA.  1977.  "The Sources and Behavior of Heavy Metals in
Wastewater and Sludges", EPA-600/2-77-070.  Cincinnati, OH:  U.S.
Environmental Protection Agency, Municipal Environmental Research
Laboratory.

EPA.  1978a.  "Microbiological Methods for Monitoring the
Environment, Water and Wastes", EPA-600/8-78-017.  Cincinnati,
OH:  U.S. Environmental Protection Agency, Environmental
Monitoring and Support Laboratory.

EPA.  1978b.  "Validity of Fecal Coliforms, Total Coliforms, and
Fecal Streptococci as Indicators of Viruses in Chlorinated
Primary Sewage Sludge Effluents", EPA-600/J-78-175.  Cincinnati,
OH:  U.S. Environmental Protection Agency, Environmental
Monitoring and Support Laboratory.

EPA. 1979a.  "Methods for Chemical Analysis of Water and Wastes",
EPA-600/4-79-020.  Cincinnati, OH:  U.S. Environmental Protection
Agency, Environmental Monitoring and Support Laboratory.
                             6-1

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EPA.  I979t>.  "Process Design Manual - Sludge Treatment and
Disposal", EPA 625/1-79-011.  Cincinnati, OH:  U.S. Environmental
Protection Agency, Municipal Environmental Research Laboratory.

EPA.  1981.  "Parasites in Southern Sludges and Disinfection by
Standard Sludge Treatment", EPA-600/2-81-166.  Cincinnati, OH:
U.S. Environmental Protection Agency, Municipal Environmental
Research Laboratory.

EPA.  1983a.  "Process Design Manual - Land Application of
Municipal Sludge", EPA-625/1-83-016.  Cincinnati, OH:  U.S.
Environmental Protection Agency, Municipal Environmental Research
Laboratory.

EPA.  1983b.  "Interim Guidelines and Specifications for
Preparing Quality Assurance Project Plans".  PB83-170514,
QAMS-005/80.  Office of Research and Development.

EPA.  1984a.  "Multielemental Analytical Techniques for Hazardous
Waste Analysis:  The State-of-the-Art", EPA-600/4-84-028.  Las
Vegas, NV:  U.S Environmental Protection Agency, Environmental
Monitoring Systems Laboratory.

EPA.  -1984b.  "Interim Methods for the Measurement of Organic
Priority Pollutants in Sludges".  Cincinnati, OH:  U.S. ,
Environmental Protection Agency, Environmental Monitoring and
Support Laboratory.

EPA.  1984c.  "Development of Analytical Test Procedures for the
Measurement of Organic Priority Pollutants in Sludge",
EPA-600/4-84-001.  Cincinnati, OH: Environmental Monitoring and
Support Laboratory.

EPA.  1984d.  "USEPA Manual of Methods of Virology",
EPA-600/4-84-013.  Cincinnati, OH:  U.S. Environmental Protection
Agency, Environmental Monitoring and Support Laboratory.

EPA. 1986a.  "Proceedings:  Workshop on Effects of Sewage Sludge
Quality and Soil Properties on Plant Uptake of Sludge - Applied
Trace Constituents".  Las Vegas, NV:  U.S. Environmental
Protection Agency, Office of Research and Development.

EPA.  1986b.  "Test Methods for Evaluating Solid Waste, SW-846".
Washington, D.C.:  U.S. Environmental Protection Agency, Office
of Solid Waste and Emergency Response.

EPA.  1987.  "Preparation Aid for HWERL's Category II Quality
Assurance Project Plans".  Cincinnati, OH:  U.S. Environmental
Protection Agency, Office of Research and Development.
                             6-2

-------
EPA.  1988a.  "Analytical Methods for the National Sewage Sludge
Survey".  Washington, D.C.:  U.S. Environmental Protection
Agency, Office of Water Regulations and Standards.

EPA.  1988b.  "Draft Guidance for Writing Case-by-Case Permit .
Requirements for Municipal Sewage Sludge".  Washington, B.C.:
U.S. Environmental Protection Agency, Office of .Water Enforcement
and Permits.

EPA.  1988c.  "Strategy for Interim Implementation of Sludge
Requirements in Permits".  Washington, B.C.:  U.S. Environmental
Protection Agency, Office of Water Enforcement and Permits (final
due August 1989) .

EPA.  1989.  "Control of Pathogens in Municipal Wastewater Sludge
for Land Application". (Braft May 1989, final due August 1989).

"Guidelines for Establishing Test Procedures for the Analysis of
Pollutants," 40 CFR Part 136.  Washington, B.C.;  National
Archives and Records Administration, Office of the Federal
Register.

"Memorandum:  Pathogen Equivalency Committee," U.S. Environmental
Protection Agency, Office of Water, November 2, 1987.

Metcalf and'Eddy, Inc.  1979.  Wastewater Engineering.
Treatment, Bisposal, Reuse.  New York:  McGraw-Hill Book Company.
                             6-3

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      APPENDIX  A
CHAIN OF CUSTODY RECORD

-------
                                               Chain of  Custody Record
 W.O. No.
Project Name
 Samplers: (Signature)
  Sta. No.      Date       Time
                   Station Description
                                                                Sample
                                                                 Type
                              Number
                              and
                              Type of
                              Containers
                                                                                               Remarks
     Relinquished By: (Signature)
              Date
Time
Received By: (Signature)
(Print)
Comments
Source: 1987 [PA Document 'Preparation Aid for HW[RL"i Category II Quality Asuirance Project flam'

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           APPENDIX B
DETERMINATION OF VOLATILE SOLIDS

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                        DETERMINATION OF VOLATILE SOLIDS
                            REDUCTION IN DIGESTION1
                                By J.B. Farrell
 INTRODUCTION
      When sewage sludge is utilized on  land,  Federal  regulations  require  that
 it  be treated by a "process to significantly  reduce pathogens"  (PSRP)  or  a
 "process  to  further reduce pathogens" (PFRP).  A  requirement of both of  these
 steps is  a reduction in "vector attraction" of the sludge.  If  the  PSRP or
 PFRP  is anaerobic or aerobic digestion,  the requirement  for vector  attraction
 reduction is achieved if volatile  solids  are  reduced  by  38 percent.  As
 Fischer1  has noted,  the Federal regulation2 does  not  specify a  method  for
 calculating  volatile solids reduction.  Fischer observed  that the United
 Kingdom has  a similar requirement  for volatile solids reduction for digestion
 (40 percent),  but also failed to prescribe a  method for  calculating volatile
 solids reduction.    Fischer has provided  a comprehensive  discussion of the
 ways  that volatile solids reduction may be calculated and their limitations.
 He  presents  the  following equations for determining volatile solids reduction:

      1.   Full mass balance equation
      2.   Approximate mass balance  equation
      3.   "Constant ash"  equation
      4.   Van Kleeck equation

      The  full  mass balance equation is the least  restricted but requires  more
 information  than  is  currently  collected at a wastewater treatment plant.   The
approximate  mass  balance  equation  assumes steady  state conditions.  The
"constant  ash" equation  requires the assumption of steady state conditions as
veil  as the  assumption  that  ash  input rate equals ash output rate.  The Van
Kleeck equation,  which  is  the  equation generally  suggested in publications
originating  in the United  States3  is equivalent to the "constant ash"
equation.   Fischer calculates  volatile solids reduction using a number of
1 Source:  "Control of Pathogens in Municipal Wastewater Sludge,"  EPA, to be
          published August, 1989.
                                     B-l

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 examples of considerable complexity and illustrates  that  the different  methods
 frequently yield different results.   He closes  with  the recommendation,
 obviously directed to rulemakers,  that  "if it  is  necessary to specify a
 particular value for FVSR (fractional volatile  solids  reduction)  then the
 specification should indicate the  method of calculation of FVSR."

      Fischer's paper is extremely  thorough and  is highly  recommended  for
 someone trying to develop a deep understanding  of potential complexities in
 calculating volatile solids reduction.   However,  it  was not written as  a
 guidance document for field staff  faced with the  need  to  calculate volatile
 solids  reduction in their own plant.  The nomenclature is precise but so
 detailed that it makes  comprehension  difficult.   In  addition,  two important
 troublesome situations  that complicate  the calculation of volatile solids
 reduction—grit  deposition in digesters and decantate  removal—are not
 explicitly discussed.   Consequently,  this presentation has  been prepared to
 present guidance that describes the major pitfalls likely to be encountered in
 calculating volatile solids reduction and assists  the  practitioner of
 digestion to the best route to take for his situation.

     The recommendation of this presentation is not  the same as Fischer's.   He
 suggests that  the authorities  should  have provided a calculation method  when
 they required  specific  volatile solids  reductions.  From  a  review of  Fischer's
 results  and  this presentation, it will  be clear that sometimes very simple
 calculations will give  correct results  and  in other cases  the simple  methods
will yield  results  seriously  in error.   Selecting one  method  and requiring
 that it  be  followed  is  excessively restrictive.  The best solution is to
 require  that  the calculation be done  correctly and then provide adequate
guidance.  This  presentation attempts,  belatedly, to provide  that adequate
guidance.

     It  is important to note  that the calculations of  volatile solids
reduction will only  be as  accurate as the measurement  of volatile solids
content  in the sludge streams.  The principal cause of error  is poor  sampling.
Samples should be representative,  covering  the entire  charging and withdrawal
periods.  Averages should  cover extended  periods of time during which changes
in process conditions are minimal.   For some plants it is  expected that
                                     B-2

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 periodic  checks  of  volatile  solids  reduction  will  produce'results  so  erratic
 that  no confidence  can  be  placed  in them.   In this case, adequacy  of
 stabilization  can be  verified  by  the method suggested  in the  text—
 periodically batch  digest  the  product for  40  days.   If VS reduction is  less
 than  15%,  the  product is sufficiently stable.

 The Equations  for FVSR
      The  equations  for  fractional volatile solids  reduction (FVSR) that will
 be discussed below  are  the same as  developed  by Fischer , except for  omission
 of his "constant ash" equation.  This equation gives identical results  to  the
 Van Kleek equation  so it is  not shown.  Fischer's  nomenclature has been
                           »
 avoided or replaced with simpler  terms.  The  material  balance approaches are
 called "methods" rather than "equations."   The material balances are  drawn to
 fit the circumstances.  There  is no need to formalize  the method with a rigid
 set of equations.

      In the derivations and  calculations that follow,  both VS (total  volatile
 solids content of the sludge or decantate  on  dry solids basis) and FVSR are
 expressed  throughout  as fractions to  avoid  the frequent confusion that occurs
 when  these terms are  expressed as percentages.  "Decantate" is used in place
 of the more commonly  used  "supernatant" to  avoid the use of "s" in subscripts.
 Similarly,  "bottoms"  is used in place  of "sludge"  to avoid use of "s" in
 subscripts.

The "full  mass balance" method
     The  "full mass balance" method must be used when  steady conditions do not
 prevail over the time period chosen  for the calculation.   The chosen  time
period must be substantial,  at least  twice  the nominal residence time in the
digester  (nominal residence  time = average volume of sludge in the digester  +
average volumetric  flow rate.  Note:  when  there is supernatant withdrawal,
volume of  sludge withdrawn should be used  to calculate average volumetric flow
rate).  The reason  for the long time period is to reduce the influence of
short-term fluctuations in feed or product flow rates or compositions.  If
input compositions have been relatively constant for a long period of time,
 then the  time period  can be  shortened.
                                     B-3

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      An example where the full mass balance method would be needed is an
 aerobic digester operated as follows:

      1.  Started with the digester 1/4 full (Time zero).
      2.  Raw sludge is fed to the digester daily until digester is full.
      3.  Supernatant is periodically decanted  and raw sludge is charged into
          the digester until not enough settling occurs to accommodate daily
          feeding.   (Hopefully this will not occur until enough  days have
          passed for adequate digestion.)
      4.  Draw down  the digester to about 1/4 full (final time),  discharging
          the sludge to sand beds.
      The full mass  balance is written  as follows:

          Sum of total volatile solids  inputs in feed  streams
          during the entire digestion period -  sum of  volatile
          solids outputs in withdrawals of  decantate and bottoms  +
          loss of volatile solids  + accumulation of volatile
          solids in  the digester.                                            (1)

Loss  of volatile solids is calculated  from Equation 1.   FVSR is  calculated  by
Equation 2:

          FVSR - loss  in volatile  solids
                sum of volatile solids inputs                               (2)
     The accumulation of volatile solids in the digester is the final volume
in the digester after the drawdowns times final volatile solids concentration
less the initial volume at time zero times the initial volatile solids
concentration.

     To properly determine FVSR by the full mass balance method requires
determination of all feed and withdrawal volumes, initial and final volumes in
the digester and determination of volatile solids concentrations on all
streams.  In some cases, which will be discussed later, simplifications are
possible.
                                     B-4

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The  "approximate mass balance"  method
      If  volumetric inputs and outputs  are  relatively  constant  on  a  daily
basis, and  there is no substantial  accumulation  of  volatile  solids  in  the
digester over the time period of  the  test,  an  approximate mass balance (AMB)
may  be used.   The basic relationship  is  stated simply:

      volatile solids input rate = volatile  solids output
          rate +  loss of volatile  solids.                                    (3)
      The FVSR is given by Equation  2.
      No  decantate,  no grit accumulation  - Calculation of FVSR  is  illustrated
for  Problem 1 in Table 1 which  represents a simple  situation with no decantate
removal  and no grit accumulation.   An  approximate mass balance is applied to
the  digester  operated under constant flow conditions.  Since no decantate is
removed  volumetric  flow rate of sludge leaving the  digester equals  flow  rate
of sludge entering.   Applying Equations  3 and  2,

          FY,  » BYh  + loss                                                  (A)
            I      D
          Loss -  100 (50-30)  - 2000                                          (5)
         FVSR - Loss                                                        (6)
                FY,
         FVSR -   2000     - 0.40                                           (7)
                (100)(50)
     Nomenclature is given in Table 1.  Note that the calculation did not
require use of the fixed solids concentrations.

     The calculation is so simple that one wonders why it is so seldom used.
One possible reason is that the input and output volatile solids concen-
trations (Yf and Yb) may show greater coefficients of variation (standard
deviation + arithmetic average) than the fraction volatile solids (VS,
fraction of the sludge solids that is volatile—note the difference between VS
and Y).
                                     B-5

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      Grit  deposition - Grit  deposition can be a serious problem in both
 aerobic  and anaerobic digestion.   The biological processes that occur in
 digestion  dissolve or destroy the substances  suspending the grit and it tends
 to  settle.   If  agitation is  inadequate to keep the  grit particles in
 suspension they will accumulate  in the digester.  The  approximate mass balance
 can be used to  estimate accumulation  of fixed solids.

      For Problem 1,  the balance yields the following:

         FX_  =  B.XK  + loss  '                                                 (8)
            CD
                (100)(17)  - (100)(17)  + Fixed  Solids  Loss                    (9)
                                                           •
                Fixed Solids  Loss  - 0                                       (10)
      The material  balance compares fixed  solids  in output  with  input.   If  some
 fixed solids  are missing this loss term will  be  a positive number.   Since  we
 know  that  digestion  does not  consume  fixed solids, we  assume  that  the  fixed
 solids are  accumulating in the digester.   As  Equation  10 shows,  the  fixed
 solids loss equals zero.  Note that for this  case where input and  output
 sludge flow rates are  equal,  the  fixed solids  concentrations are equal when
 there is no grit accumulation.

      The calculation of  fixed  solids  is repeated for Problem 2.  Conditions in
Problem  2 have  been  selected  to show  grit  accumulation.  Parameters  are the
same  as  in Problem 1 except for the fixed  solids concentration  (Xb)  and
parameters related to  it.  Fixed  solids concentration  in the digested  sludge
is lower than in Problem 1.  Consequently, VS  is higher and mass flow  rate of
solids (input rate » output rate  + rate of loss of fixed solids) is  presented
in Equation 11-13.

               FXf = BXb + Fixed  Solids Loss                               (11)
               Fixed Solids Loss  = FXf - BXb                               (12)
               Fixed Solids Loss  = (100)(17) - (100)(15) = 200 kg/d        (13)
                                     B-6

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      The material balance,  which only looks at inputs and outputs,  informs us
 that  200 kg/d of fixed solids have not appeared in the outputs as expected.
 We  know that fixed solids are not destroyed and conclude that they are-
 accumulating in the bottom of 'the digester.  The calculation of FVSR for
 Problem 2 is exactly the same as for Problem 1 (see Equations 4-7)  and yields
 the same result.   The accumulation of solids does not change the result.

      Decantate withdrawal,  no grit accumulation - In Problem 3,  supernatant is
 withdrawn daily.   Volatile and fixed solids concentrations are known for all
 streams but  the volumetric flow rates are not known for decantate and bottoms.
 It  is impossible to calculate FVSR without knowing the relative volume balance
 and a fixed  solids balance,  provided it  can be assumed that loss of fixed
 solids (i.e.,  accumulation in the digester) is zero.

      Selecting a basis for  F of 100 m3/d,
          Volume balance:   100 -B+D                                     (11)
          Fixed solids balance:   100 X{ - BXb  + OXd                         (12)
      Since the three Xs  are  known,  B and D can be found.
     Substituting  100-D  for  B  and  the values  for  the Xs  from Problem  3  and
solving  for D and  B.

          (100)(17) 3  (100  -D)(23.50) +  (D)(7.24)                          (13)
          D . 40.0  m3/d,  B  »  60.0 m3/d                                     (14)
          The FVSR  can now  be calculated by drawing a volatile solids  balance:
          FYf = BYb + DYd + loss                                           (15)
                loss = FYf - BY.  - DY
          FVSR = 	   	                                    (16)
                FYf          FYf
          FVSR = (100)(50)  -  (60)(41.42) - (40)(12.76) = 0.40              (17)
                             (100)(50)

     Unless information  is available on actual volumes of decantate and
sludge,  there is no way  to determine whether grit is accumulating in  the
digester.  If it is accumulating, the calculated FVSR will be in error.
                                      B-7

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      When we make the calculation shown in Equation 15-17,  we assume that the
 volatile solids that  are missing from the output  streams  are  consumed by
 biological reactions  that convert them to carbon  dioxide  and  methane.  Ve
 assume accumulation is negligible.   Volatile  solids are less  likely  to
 accumulate than fixed solids  but it  can happen.   In poorly  mixed  digesters,
 the  scum layer that collects  at  the  surface is an accumulation of volatile
 solids.   FVSR calculated by Equations 15-17 will  be overestimated if volatile
 solids accumulation rate is substantial.

      Decantate withdrawal and grit accumulation - In Problem  4, there is
 suspected grit accumulation.   The quantity of B and D can no  longer  be
 calculated by Equations  11 and 12 because Equation 12 is  no longer correct.
 The  values of B and D must be measured.   All  parameters in  Problem 4 are the
 same as  Problem 3  except measured values  for  B and 0 are  introduced  into
 Problem  4.   Values of B  and D calculated  assuming no grit accumulation
 (Problem 3—see previous section), and  measured quantities  are compared  below:

                                        Calculated     Measured
                         B                  60          49.57
                         D                  40          50.43

     The differences  in  the values of B and 0 are not  large but they make  a
 substantial  change in  the numerical value  of FVSR.   The FVSR  for  Problem 4 is
 calculated below:

          FVSR  -  (100)(50)  - (49.57)(41.42)  - (50.43)(12.76) =  0.461        (18)
                                 (100)(50)

If it had  been assumed that there was no grit accumulation, FVSR would equal
0.40 (see  Problem  3).   It  is  possible to determine  the amount  of grit
accumulation  that  has caused  this change.  A material balance  on  fixed solids
is drawn:

               FX, = BX.   + DX. + Fixed Solids Loss                         (19)
                 c     D      a
                                     B-8

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      The fractional fixed solids loss due to grit accumulation is found by
 rearranging this equation:

                Fixed Solids Loss   FX.  - BX-  - DX.                        (20)
                                      f      o      a
                       '    •-_-	   = -- -_.-—! Ill— I IL	 _.
                        FXf               FXe

      Substituting in the parameter values for Problem 4.

          Fixed  Solids Loss  = (100)(17)  - (49.57)(23.50)  -  (50.43)(7.24)   (21)
                FXf                       (100)(17)
                                = 0.100

      If  this  fixed  solids loss  of 10  percent  had  not  been  accounted  for,  the
 calculated  FVSR would have  been 13 percent  lover  than the  correct value of
 0.461.   Note  that if grit accumulation  occurs and it  is  ignored,  calculated
 FVSR  will be  lower  than the actual value.

 The Van  Kleeck  Equation
      Van Kleeck first presented  his equation  without  derivation in a  footnote
 for a review  paper  on sludge treatment  processing in  19454.  The  equation  is
 easily derived  from total solids and  volatile solids  mass  balances around  the
 digestion system.   Consider a digester  operated under steady state conditions
 with  decantate  and  bottom sludge removal.  A  total solids  mass balance  and a
 volatile solids mass balance are:

          Mt = Mb  *  Md  *                              <22>
          M  -VS.  = M -VS.  +  M.-VS,  + (Loss of  volatile solids)              (23)
          £   £     DO     a    a

The masses must  be  mass of  solids  rather  than total mass of liquid and  solid
because  VS is an unusual  type of concentration unit—it is "mass  of volatile
solids per unit mass  of total solids."

      It  is now  assumed  that  fixed  solids are  not  destroyed and there  is no
grit  deposition in  the  digester.   The losses  in Equations 22 and  23 then
comprise  only volatile  solids so the losses are equal.  It is also assumed
that  the  VS of  the  decantate and of the bottoms are the same.  This means  that
the bottoms may have a  much higher  solids content  than the decantate  but the
                                      B-9

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proportion of volatile solids to fixed solids is the same for both streams.
Assuming then that VSb equals VSd and making this substitution in the defining

equation for FVSR (Equation 2),


                Loss of vol. solids = 1 - (M.  + M.) VS.
         FVSR --       -^ - 1 - b-                    (24)
                       Mf-VSf                 Mf-VSf


         From Equation 22, recalling that we have assumed that loss of  total

         solids equals loss of volatile solids,


               MK + M. = M. - loss of vol. solids                          (25)
                D    a.    I


         Substituting for Mb * Md into Equation 24,


                          (M  - Loss of vol. solids)
               FRVS = 1 -- -VS                   (26)
                                   Mf-VSf


         Simplifying further,


               FRVS - 1 - (1 - FRVS) -VS.                                    (27)
         Solving for FRVS,
                        VS.  - VS.
               FRVS = - - - - —                                       (28)
                      VSf  -  VSf-VSb


         This is the form  of the Van Kleeck Equation found in WPCF's Manual of
         Practice No. 163 .   Van Kleeck4  presented the equation in the

         following equivalent form:
                          VSb-(l - VSf)
               FRVS = 1 - -                                   (29)
                          VSf-(l - VSb)
                                    B-10

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      The  Van Kleeck Equation is applied  below to  Problems  1-4  in  Table 1 and
 compared  to  the approximate mass balance equation results:

                                         1.2       3      4
      Approximate Mass Balance (AMB)     0.40    0.40    0.40    0.461
      Van  Kleeck (VK)                    0.40    0.318   0.40    0.40

      Problem  1:   No decantate and  no  grit  accumulation.  Both methods  give
                  correct  answers.
      Problem  2:   No decantate but  grit  accumulation.  VK is  invalid  and
                  incorrect.
      Problem  3:   Decantate but  no  grit  accumulation.  AMB method is  valid VK
                  method is valid only if VS.   - VS..
                                    •      D     a
      Problem  4:   Decantate and  grit acumulation.  AMB method valid only  if  B
                  and  D are measured.  VK method  is invalid.

      The  Van  Kleeck equation  is seen  to have  serious  shortcomings when applied
to certain practical  problems.  The AMB method can be completely reliable
whereas the Van  Kleeck method is useless under some circumstances.

      Review and  Discussion of Calculation  Methods and Results
      Complete Mass Balance Method  - The complete mass balance method allows
calculation of volatile solids  reduction of all approaches to digestion, even
processes where  final  volumes in the  digester  does not equal initial volume
and where daily  flows  are not steady.   A serious drawback is the need  for
volatile solids  concentration and  volumes  of all streams added to or withdrawn
from  the digester as well as  initial  and final volumes and concentrations in
the digester.  This can be a  daunting task particularly for the small plants
which are most likely  to run  their digesters in other than steady flow modes.
For plants of this kind, an "equivalent" method that  shows that the sludge has
undergone the proper volatile solids  reduction is likely to be a better choice
than  trying to demonstrate 38 percent volatile solids reduction.  An aerobic
sludge has received treatment equivalent to a  38 percent volatile solids
reduction if  specific  oxygen  uptake rate is below a specified maximum.
                                     B-ll

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 Anaerobically digested sludge has received treatment equivalent to a 38
 percent volatile solids reduction if volatile solids reduction after batch
 digestion of the product sludge for AO days is less  than a specified maximum .

      Approximate Mass Balance (AHB) Method - The  approximate  mass  balance
 method assumes that daily flows are steady and reasonably uniform  in com-
 position,  and that  digester volume and composition does  not vary substantially
 from day to day.  Results of calculations  and an  appreciation of underlying
 assumptions show that the method is accurate for  all cases, including with-.
 draval of  decantate and deposition of grit,  provided that in  addition to
 composition of all  streams the quantity of decantate and bottom^ (the digested
 sludge) are known.   If the quantities of decantate and bottoms are not known,
 the  accumulation of grit cannot be determined.  If accumulation of grit is
 substantial and FVSR is calculated assuming it  to be negligible, FVSR will be
 lower than the true value.   The result is  conservative and  could be used  to
 show that  minimum volatile solids reductons  are being achieved.

      The Van Kleeck Equation - The Van Kleeck Equation has  underlying
 assumptions that  should be made clear wherever  the equation is presented.   It
 is never valid when there is grit accumulation  because it assumes  the fixed
 solids  input  equals fixed solids  output.   Fortunately, it produces  a  con-
 servative  result  in this case.   Unlike the AMB  method it  does  not  provide  a
 convenient  way to check for accumulation of  grit.  It can be  used  when
 decantate  is  withdrawn provided VSb  equals VSd.   Just how big  the  difference
 between these VS  values  can be before an appreciable  error  in  FVRS  occurs  is
 unknown, although it  could  be determined by  making up a  series  of  problems
 with  increasing differences between  the  VS values, calculating FRVS using  the
 AMB method  and a  Van  Kleeck equation,  and  comparing  results.

     The shortcomings  of  the Van  Kleeck  equation  are  substantial and  may
 eventually  lead  to  a  recommendation  not  to use  it.  However,  it has one strong
 point.  The VS of the  various  sludge  and decantate streams are  likely  to show
much lower  coefficients  of  variation  (standard deviation  + arithmetic  average)
 than volatile  solids and  fixed  solids  concentration.   Review of data  are
needed  to determine how  seriously  the  variation in concentrations affect the
confidence  interval of FVSR calculated by  both methods.   A hybrid approach may
                                     B-12

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turn out  to  be advantageous.  The  AMB  method  could  be used  first  to  determine
if grit accumulation  is  occurring.   If grit is not  accumulating,  the Van
Kleeck equation  could be used.   If decantate  is withdrawn,  the Van Kleeck
equation  still cannot be used unless VSb  is nearly  equal  to VSd.

     Average Values - The concentrations  and  VS values used in the equations
will all  be  averages.  For the material balance methods,  the averages should
be weighted  averages  according to  the  mass of solids in the stream in
question.  The example below shows how to average the volatile solids con-
centration for four consecutive  sludge additions.

                                   Volatile Solids
     Addition      Volume          Concentration
        1          10 m3               50  kg/m3
        2           7m3               45  kg/m3
        3          15 m3               40  kg/m3
        4          12 m3               52  kg/m3
        Y av . 10 X 50 +  7 X 45  +  15 X 40 + 12 X 52 = 46.3  kg/m3          (30)
                              10 + 7 + 15 + 12

     For  the Van Kleeck equation,  the  averages of VS are required.   Properly
they should be weighted averages based on the weight of the solids in each
component of the average  although an average  weighted by the volume  of the
component or an arithmetic average may be sufficiently accurate if variation
in VS is small.  The  following example demonstrates the calculation  of all
three averages.

                                     Total Solids
         Addition       Volume
            1             12 m3
            2             8m3
            3             13 m3
            4             10 m3
Concentration
72 kg/m3
50 kg/m3
60 kg/m3
55 kg/ra3
VS
0.75
0.82
0.80
0.77
                                     B-13

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Weighted by Mass

VS av =       12 X 72 X 0.75 + 8 X 50 X 0.82
                    '	^ 13 X 60 X 0.80 +'10 X 55 X 0.77             (31)
                   12 X 72 + 8 X 50 + 13 X 60 + 10 X 55:= 0.795

Weighted by Volume

VS av «       12 X 0.75 + 8 X 0.82 + 13 X 0.80 -t- 10 X 0.77                 (32)
                        12+8+13+10- 0.783

Arithmetic Average

VS av .       0.75 + 0.82 + 0.80 + 0.77                                    (33)
                   :5= 0.785

In this example the arithmetic average was nearly as close as the volume-

weighted average to the mass-weighted average, which is the correct value.
                                    B-1A

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                           LITERATURE CITED
Fischer, W.J., "Calculation of volatile solids during sludge digestion,"
p 499-529, in Bruce A. (ed.) "Sewage Sludge Stabilization and
Disinfection," pub. for Water Research Centre by E. Horvood Ltd.,
Chichester, England (1984).

U.S. EPA, Code of Federal Regulations, Title 40, part 257 (40 CFR 257),
"Part 257—Criteria for Classification of Solid Waste Disposal Facilities
and Practices."

Water Pollution Control Federation, Manual of Practice No. 16, "Anaerobic
Sludge Digestion," pub. Water Pollution Control Federation,  Washington, DC
(1968).

Van Kleeck, L.W., Sewage Works J., 17 (6), 1240-1255 (1945),  "Operation of
sludge drying and gas utilization units," Refer to footnote on p 1241.

U.S. EPA, "Technical Support Document:  Pathogens," pub. by EPA's Office
of Water Regulation and Standards, Washington, DC  (1989).
                                 B-15

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                                                           TABLE 1
                                     QUANTITATIVE INFORMATION FOR EXAMPLE PROBLEMS
                                                                                   1.2,3
w
i-»
o\
        Parameter
Nominal residence time
Time period for averages

Feed Sludge
  Volumetric flow rate
  Volatile solids concentration
  Fixed solids concentration
  Fraction volatile solids
  Mass flow rate of solids

Digested Sludge (Bottoms)
  Volumetric flow rate
  Volatile solids concentration
  Fixed solids concentration
  Fraction volatile solids
  Mass flov rate of solids

Pecantate
  Volumetric flov.rate
  Volatile solids concentration
  Fixed solids concentration
  Fraction volatile solids
  Mass flov rate of solids
Symbol


6
                                                         M
                                                         B
                                                         D

                                                         S.
                                                         M '
                                                                Units
                                                                        d
                                                                        d
               mVd
               kg/m3
               kg/m3
               kg/kg
               kg/d
                   3
               kg/m3
               kg/m
               kg/kg
               kg/d
                   3
               kg/m3
               kg/m3
               kg/kg
               kg/d
Problem Statement Number
1
20
60
100
50
17
0.746
6700
100
30
17
0.638
4700
0
_
_
_
2
20
60
100
50
17
0.746
6700
100
30
15
0.667
4500
0
_
_
—
3
20
60
100
50
17
0.746
6700

41.42
23.50
0.638


12.76
7.24
0.638
4
20
60
100
50
17
0.746
6700
49.57
41.42
23.50
0.638

50.43
12.76
7.24
0.638
        1.  Conditions are steady state; all daily flovs are constant.  Volatile solids are not accumulating in the
            digester, although grit may be settling out in the digester.

        2.  Numerical values are given at 3 or 4 significant figures.  This is unrealistic considering the expected
            accuracy in measuring solids concentrations and sludge volumes.  The purpose of extra significant figures
            is to allow more understandable comparisions to be made of the different calculation methods.
        3.  All volatile solids concentrations are based on  the total solids, not merely on the suspended solids.

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