POTW SLUDGE SAMPLING AND ANALYSIS
GUIDANCE DOCUMENT
June 1988
Submitted to:
U.S. Environmental Protection Agency
401 M Street, S.V.
Washington, D.C.
In response to:
EPA Contract No. 68-01-7043, WA fP2-5
SAIC Project No. 2-835-07-540-01
Submitted by:
Science Applications International Corporation
8400 Westpark Drive
McLean, Virginia 22102
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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 nunicipal
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.
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TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS
1. INTRODUCTION 1-1
2. SLUDGE SAMPLING 2-1
2.1 BACKGROUND INFORMATION 2-1
2.1.1 Solids Content and Viscosity 2-1
2.1.2 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 Devatered 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
Flux Data 2-6
2.2.2 Sludge Sample Points 2-7
2.3 SAMPLE COLLECTION 2-7
2.3.1 General Considerations 2-7
2.3.2 Proper Sampling Practices ;.. 2-10
2.4 SAMPLE TYPE, SAMPLE NUMBER, AND SAMPLING FREQUENCY 2-10
2.4.1 Opportunities for Cost Savings 2-14
2 . 5 SAMPLE PREPARATION AND PRESERVATION 2-15
2.5.1 Sample Container Material 2-15
2.5.2 Sample Container Preparation 2-15
2.5.3 Sample Preservation 2-16
2.5.4 Holding Time Prior to Analysis 2-17
iii
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TABLE OF CONTENTS (Continued)
Page
2.6 PACKAGING AND SHIPPING 2-17
2.6.1 Packaging 2-17
2.6.2 Transportation Regulations 2-17
2.7 DOCUMENTATION 2-20
2.7.1 Sample Labeling 2-20
2.7.2 Chain-of-Custody 2-20
2.7.3 Sampling Log Book 2-21
2.8 SAFETY CONSIDERATIONS 2-21
3. ANALYTICAL PROCEDURES. 3-1
3.1 CONVENTIONAL POLLUTANT PARAMETERS 3-1
3.2 METALS 3-4
3.2.1 Analyte Isolation/Preparation Overview 3-4
3.2.2 Analytical Techniques for Metals 3-5
3.2.2.1 Sample Preparation/Digestion 3-5
3.2.2.2 Analytical Detection Methods 3-7
3.3 ORGANICS 3-11
3.3.1 Overview of Analyte Extraction and Isolation 3-13
3.3.2 Recommended Analytical Techniques for
Organics 3-15
3.3.2.1 Methods 1634 and 1635 3-16
3.3.2.2 Methods 624-S and 625-S 3-17
3.4 PATHOGENIC MICROORGANISMS 3-19
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 5-3
5.4 SAMPLING EQUIPMENT COSTS 5-5
6. REFERENCES 6-1
A. APPENDIX A A-l
iv
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LIST OF TABLES
Table Page
2.1 Total Solids Concentrations of Various Low and High
Viscosi ty Sludges 2-2
2.2 Sludge Flow Measurement Devices 2-6
2.3 Sludge Sampling Points 2-8
2.4 Containers, Preservation, Holding Times, and Minimum Sample
Volume 2-11
2.5 Potential Interferences Associated with Sampling Shipping
and Storage 2-18
2.6 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 2-19
3.1 Analytical Techniques for Conventional Pollutants 3-2
3.2 Recommended Preparation Technique for Elemental Analysis
of Sludge Samples 3-6
3.3 Comparison Summary of ICAP and AAS 3-9
3.4 Recommended Inductively Coupled Plasma Wavelengths and Estima-
ted Instrumental Detection Limits 3-10
3.5 Atomic Absorption Concentration Ranges 3-12
3.6 Analytical Techniques for Determination of Pathogenic
Microorganisms in Sewage Sludge 3-21
5.1 Typical Contract Analytical Costs for Commonly Analyzed
Parameters 5-4
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ACKNOWLEDGEMENTS
This guidance document was completed under the direction of Tom Vail and
Cristina Morrison of the U.S. EPA's Office of Water Enforcement and Permits.
This document was prepared by Science Applications International Corporation
(SAIC) under EPA Contract No. 68-01-7043.
The SAIC Work Assignment Manager was Werner B. Zieger. Significant con-
tributions vere made by Jorge McPherson, John Sunda, and Mark Klingenstein.
vi
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1. INTRODUCTION
The 1987 Water Quality Act requires EPA to immediately issue permits to
POTVs for sludge use and disposal, or to take other appropriate Measures to
protect public health and the environment (PL100-4), February 1987. To
fulfill this directive, EPA intends to require sludge monitoring in reissued
POTV NPOES permits and, in some cases, EPA may vrite sludge quality limits
into NPDES permits. (EPA's Strategy for Interim Implementation of Sludge
Requirements in Permits Issued to POTVs, available from EPA's Office of Vater
Enforcement and Permits (EN-336, U.S. EPA, 401 M Street SV, Washington, D.C.
20460), provides additional information on EPA's interim sludge permitting
program.) Thus, in addition to the reasons POTVs now have for sampling and
analyzing their sludge (for example, to determine compliance vith existing
State or Federal requirements on sludge use and disposal, setting maximum
headvorks loadings for pollutants in the influent to the POTV, etc.), many
POTVs vill soon be asked to submit data on sludge quality to EPA or State
NPDES permit writers and compliance monitoring staff.
POTVs currently use a variety of methods to sample sludges and to analyze
them. The purpose of this manual is to provide guidance to POTV operators
and EPA and State permit vriters on vhich methods should be used vhen samples
are dravn and analyzed in order to comply vith NPDES permit program and
pretreatment program requirements. The recommended methods are those used by
EPA's Office of Vater or Office of Solid Vaste and Emergency Response, or
methods specified in Federal Regulations.
Chapter Two provides guidance on sampling procedures for POTV sludges.
Chapter Three provides guidance on vhich analytical methods should be used.
Chapter Four presents information on sampling and analysis quality assurance.
Chapter Five examines sampling and analysis costs.
EPA intends to revise this document as nev information on POTV sludge
sampling and analysis becomes available. Readers are invited to submit their
comments to the Office of Vater Enforcement and Permits (address provided
above).
1-1
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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 POTV. In order to sample a sludge
stream effectively, it is necessary for sampling personnel to be avare 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 high
solids content as compared to most vastevaters. Solids content and solids
settling characteristics determine whether a given sludge will fractionate.
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. Those automatic samplers which rely on pumps
may be useful only for liquid sludges with a solids content of less than 20
percent while manual grab sampling is necessary for sludge cakes. However,
other problems created by sludge solids generally preclude the use of auto-
matic samplers. Table 2.1 summarizes the total solids concentrations of low
and high viscosity sludges and dewatered sludges.
Solids content is also significant from an analytical standpoint.
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
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TABLE 2.1. TOTAL SOLIDS CONCENTRATIONS OF VARIOUS
LOW AND HIGH VISCOSITY SLUDGES
Sludge Source Total Solids (X)
LOW VISCOSITY SLUDGES:
Digested Sludges (Unthickened) <4
HIGH VISCOSITY SLUDGES:
Digested Sludges (Thickened) 4-10
SLUDGE CAKES:
Raw Primary Plus Secondary 15-25
Secondary 8-25
Anaerobic Digested Primary Plus Secondary 15-30
Primary Plus Secondary Plus Alum 15-25
Primary Plus Secondary Plus Ferric Chloride 15-25
Primary Plus Secondary Plus Lime 20-35
and increase analytical accuracy, or carry away pollutants and decrease pollu-
tant concentration and analytical accuracy. However analytical precision and
accuracy may decrease as the concentration of Interfering compounds and matrix
effects increase.
2.1.2 Processed Sludge Characteristics
The quantity and quality of sludge generated depends on raw vastevater
characteristics and the sludge treatment practices. The sludge to be sampled
may be in the form of a liquid, devatered cake, compost product, or dried
powder. Some of the physical characteristics of each sludge type are
described belov.
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 an
inoffensive odor. The addition of chemicals coagulates a digested sludge
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prior to mechanical devatering. The dry residue of digested sludge contains
30 to 60 percent volatiles. Depending on the mode of digester operation, the
percent of solids of digested sludges ranges from 4 to 8 percent.
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
Devatering converts sludge from a floving mixture of liquids and solids
to a cake-like substance more readily handled as a solid. The characteristics
of devatered sludge depends on the type of sludge, chemical conditioning, and
treatment processes employed. Density (% solids) of devatered cake ranges
from 15 to >40 percent. Thinner cake is similar to a vet manure, vhile higher
solids cake 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. Approximately 20 to 30 percent of the
volatile solids are converted to carbon dioxide and vater.
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 continued biological action. The moisture
content of dried sludge is less than 10 percent.
2-3
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2.2 SAMPLE POINT SELECTION
2.2.1 General Considerations
NPDES and pretreatment program officials need sludge quality data in
order to determine vhether sludge use or disposal Bay 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 Banner that the sample
represents, as veil as possible, the quality of the sludge as it vill be
disposed of or used.
Vhen selecting a specific sample point, the following two factors should
be carefully considered:
Sample point representation of the entire sludge stream passing that
point
Supporting flow or mass flux data.
The following paragraphs examine both concerns and present recommenda-
tions on means to address each concern.
2.2.1.1 Sample Point Representation of the Entire Sludge Stream
A particular concern in any sampling program is obtaining samples which
represent the entire flow past the sample point, throughout the sample period.
Each discrete sample should represent the entire flow cross-section at the
sampling point. Each composite sample of multiple contributory streams should
represent the entire flow cross-section of the combined stream. Ideally, a
perfectly representative sample has the same pollutant concentration as the
average of the flow at the time the sample was taken. In reality, it is not
possible to obtain a wholly representative sample of any vastestream. Effort
must be made, however, to ensure that a sample is obtained that is as repre-
sentative as possible. Therefore, the sample should be from a point where the
sludge is well-mixed. While some pollutant parameters are solids related
(particularly precipitated metals), others are liquid-fraction related (many
dissolved organics) and failure to acquire a sample with representative so-
lid/liquid fractions can significantly affect the analytical results of a
2-4
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given sample. This is particularly true of sludge streams with high percent
solids and large floe particles. In order to ensure that representative
samples are collected, these recommendations should be followed:
In sludge processing trains, the most representative sample comes from
taps on the discharge side of sludge pumps. Flow at this point in the
system is turbulent and veil mixed, with no solids separation within
the flow stream.
If a sample is drawn from a tap on a pipe containing sludge flow
(distant from the sludge pumps), determine average flow velocity
through the pipe. 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, 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.
A second consideration in many sludge sampling situations is the need to
sample multiple contributory streams. An example is the sampling of sludge
flows from several parallel sources which later combine downstream. Several
options exist to accommodate multiple streams. The most appropriate choice
depends on the sludge flow information available, the parameters being sampled
and the purpose of the generated data. Several options are as follows:
The simplest option is to withdraw equal volumes of sample from each
pump or sludge well to create a grab-composite sample. This approach
is justified in the case of identical units receiving equal flow and
generating equal sludge amounts.
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 fil-
ter 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 proportional to
the influent flow to the unit. Note that 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.
The third option is to weight grabs from individual streams based on
sludge flow data or solids flux data. Vhether 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
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limits, solids flux data would be used as the criteria for propor-
tioning grabs from parallel devatering systems, since most land
application limits are based on dry veight applications rates.
2.2.1.2 Availability of Flow Data and/or Solids Flux Data
The availability of accurate flow data (or solids flux data) is an
important consideration in planning a sludge sampling program. Host informa-
tion requirements relating to sludge characteristics involve, at least in
part, the need for data on the mass flux (i.e., Ibs/day) of pollutant
parameters found in sludge discharged from a POTV.
Portable flow monitoring devices are not veil suited to high-solids flov
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 flov measurement. When ultimate use or disposal practices
dictate monitoring sludge with a high solids content, liquid flow meters are
replaced by gross weight scales. Table 2.2 summarizes the types of flow
measurement equipment employed to monitor various sludge flows.
TABLE 2.2. SLUDGE FLOV MEASUREMENT DEVICES
Application Measurement Means
Stabilized Sludge Venturi
Flow Tube
Magnetic Meter
Positive Displacement Pump
Thickener Magnetic Meter
Positive Displacement Pump
Dewatering Belt press scales
Drying
Composting Bulk container or truck scales
Thermal Reduction
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2.2.2 Sludge Sample Points
For permits and regulation enforcement, sludge samples must come from the
treatment unit process immediately preceding disposal or use. For example, if
a POTV discharges dewatered filter cakes to a sanitary landfill, then sampling
activity focuses on the output sludge stream from the devatering device (i.e.,
vacuum filter, belt filter, etc.). Treatment processes from which sludge is
disposed or land applied are stabilization, devatering, drying, composting,
and thermal reduction. Table 2.3 summarizes sampling points used for
different sludge streams.
To examine the origin or fate of pollutants within a POTV, additional
sludge samples from influent and output of other processes may be needed. The
rationale for these additional samples is entirely site-specific.
2.3 SAMPLE COLLECTION
Having selected appropriate sampling points for a sludge sampling pro-
gram, 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:
Each grab sample, or aliquot of a composite sample, must be as
representative as possible of the total stream flow passing the
sampling point
Effort must be made to minimize the possibility of sample
contamination
The selected sampling method should be convenient and efficient.
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 important considerations
for selecting appropriate sludge sampling methods.
2.3.1 General Considerations
In general, automatic sampling devices do not work well for sludge
streams because of the solids content and viscosity of sludges. Typical
devices for automatically sampling wastewaters consist of a positive
2-7
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TABLE 2.3. SLUDGE SAMPLING POINTS
Sludge Type
Sampling Point
Anaerobically Digested
Sludge -
Aerobically Digested
Sludge -
Thickened Sludges -
Heat Treatment Sludge -
(e.g., Zimpro, Proteus)
Devatered, Dried, -
Composted, or Thermal
Reduction 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. Tvo cautions are in order concern-
ing this practice:
(1) If aerated during sampling, air entrains in
the sample. Volatile organic compounds nay
purge vith escaping air.
(2) When aeration is shut off, solids separate
rapidly in veil digested sludge.
Sample from taps on the discharge side of posi-
tive displacement pumps.
Sample from taps on the discharge side of posi-
tive displacement pumps after decanting. Be
careful when sampling heat treatment sludge
because of:
(1) High tendency for solids separation, and
(2) High temperature of sample (frequently >60°C
as sampled) can cause problems vith certain
sample containers due to cooling and sub-
sequent contraction of entrained gases.
Sample from material collection conveyors and
bulk containers. Sample from several locations
within the sludge mass and at various depths.
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displacement pump, a control module, and sample receptacle(s), and are widely
used to sample vastevater streams. Models are either permanently installed or
portable. 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 tubing and/or pump structure fouled 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.
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. devatered cake, compost, etc.), stratification can be avoided by
not only sampling at various depths, but at numerous locations over the entire
sludge pile.
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, 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 in the sample.)
Graduated glass pitchers or cylinders are used to draw grabs for manually
composited 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 addi-
tion, only stainless steel clamps should be used to attach the sample
container to the conduit.
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2.3.2 Proper Sampling Practices
Listed below are practices followed when sampling liquid sludges:
Clean all sampling equipment between each sample period to prevent
cross-contamination. Cleaning consists of thorough washing with a
laboratory soap, thorough rinsing with tap water and at least three
distilled water rinses.
To drav a fresh representative sludge sample from a tap:
a) Allow sufficient time following pump startup to clear line of
stagnant sludge, and
b) Allow sludge to flow for several seconds from tap prior to sam-
pling 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.
In manually drawing sludge samples, to maintain uniform concentration
throughout care must be taken to prevent solids separation in the
sample if the entire sample is not to be added to the composite. Use
Glass or Teflon-coated stirring rods to mix a grab sample being split
between several composite containers.
Sample aliquots should be composited directly into sample containers.
Sample containers, preservation of sample and allowable holding time
prior to analysis are discussed in Section 2.5.
When collecting samples for oil & 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.
For either devatered cakes, dried powder or compost product, combine
equal amounts collected at various locations/depths for each grab
sample to obtain a more representative sample.
Sampling activities should be adequately documented, as discussed in
Section 2.7.
2.4 SAMPLE TYPE, SAMPLE NUMBER, AND SAMPLING FREQUENCY
A proper sample is small enough to transport conveniently and handle
carefully in the laboratory, but large enough to still accurately represent
the characteristics of the whole material. Minimum sample sizes required for
accurate analysis are specified in each analytical method. Table 2.4 lists
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TABLE 2.4. CONTAINERS, PRESERVATION, HOLDING TIMES, AND MINIMUM SAMPLE VOLUMES
Parameter
Metals
Chromium VI
Mercury
Metals except above
Organic Compounds
Container
P,G
P,G
P,G
Preservative
Cool, 4°C
HN03 to pH<2
HN03 to pH<2
Maximum
Holding Time
48 hours
28 days
6 months
Minimum
Sample Volume'*1
300 mL
500 mL
1000 mL
Extractables (including
phthalates, nitrosamines
organochlorine pesticides,
PCBs, nitroaromatics,
isophorone, polynuclear
aromatic hydrocarbons,
haloethers, chlorinated
hydrocarbons and TCDD)
Extractable (phenols)
Purgeables (Halocarbons
and Aromatics)
Purgeables (Acrolein and
Acrylonitrile)
Pesticides
G, teflon-lined
cap
Cool, 4°C
0.008% Na2S203
7 days (until extraction) 1000 mL
30 days (after extraction)
G, teflon-lined
cap
G, teflon-lined
septum
G, teflon-lined
septum
G, teflon-lined
septum
Cool, 4°C
H SO. to pH<2
0.008Z Na,S,0,
7 days (until extraction) 1000 mL
30 days (after extraction)
Varies vith analytical method. Consult 40
P Plastic
G Glass
Cool 48C
0.008Z N;
Cool 4°C
0.008Z N
Cool 4°C
0.008* N
CFR Part 136.
0.008Z Na2S203
0.008Z Na2S203
0.008* Na2S203
14 days
14 days
50 mL
50 mL
7 days (until extraction) 1000 mL
30 days (after extraction)
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minimum sample sizes for some common analytical methods. For methods not
listed here consult an analytical methods book or the laboratory for further
guidance.
A grab sample collected at a particular time and point can represent the
composition of the source only at that time and point. If through historical
data a source is known to be constant in composition over a period of time, or
over distances in all directions, then the sample can be considered to
represent a longer period of time or a larger volume than the specific point
of sampling. In the case of most sludges, single grab samples vill adequately
represent only the instantaneous composition of the material being sampled.
The quality of a grab sample vill be improved if it is comprised of several
smaller samples taken over a period of a fev 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. However, a 24-hour
composite sample, consisting of a number of time- or flow-weighted grab
samples will give a picture of only one day's sludge quality. As sludge
quality is directly related to wastewater influent quality (which can vary
from day to day and hour to hour), a POTV should sample and analyze its sludge
frequently.
To the extent practicable, the POTV should have a sludge sampling prograa
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.
Important factors to consider in determining sludge monitoring frequency
include:
Anticipated cyclical variation in pollutant loadings - Anticipated
cycles include daily industrial production cycles, 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.
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Treataent plant characteristics - As either detention time or nixing
increases vithin a treatment plant, sampling frequency can be reduced
since treatment processes vill effectively composite sludge to a
greater degree. For example, high rate digestion and storage/blending
facilities vill provide mechanical mixing of sludge. Other plant
technologies, such as anaerobic digestion, aerobic digestion and
storage, provide longer sludge detention times, enabling greater
mixing through physical processes such as diffusion, convection, etc.
For combined sever systems, a sampling strategy nay be designed to
monitor the effects of storm events on sludge quality.
Risk of environmental exposures - As the risk of environmental expo-
sure from sludge use/disposal increases, a POTV 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.
Another factor to consider in determining monitoring frequency is the
percentage of flow contributed to the POTW by commercial or industrial users.
While sludge quality variability is directly related to the individual charac-
teristics of each POTW, POTWs vith little or no commercial/industrial contrib-
utors in the system can expect relatively small variation in sludge quality.
POTWs vith significant industrial contributions can expect to have monthly,
veekly and even daily variation in sludge quality.
Another consideration is the type(s) of information a POTW vishes 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 vishes to measure variation
vithin a single day, the POTW may collect and analyze several grab samples
taken at different times during the day.
POTW operators should be avare that EPA's Draft Strategy for Interim
Implementation of Sludge Requirements in Permits Issued to POTWs (June 1988)
vould require POTW operators vith knovn or suspected sludge use or disposal
problems to do a full priority pollutant scan on their sludge at least once
per year. These operators vould also have information on their sludge quality
and use or disposal practices reviewed by NDPES permit writers vhen their
2-13
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permits are renewed. Compliance with any limits on sludge quality placed into
a POTV permit vould have to be determined at least:
Once a year for POTVs vith less than 1 million gallons of flov per day
(mgd)
Quarterly for POTVs vith flows between 1 mgd and 10 mgd
Monthly for POTVs with flows greater than 10 mgd.
All other POTV operators would also be required to perform a full priority
pollutant scan annually unless current sludge data, data on industrial users*
or treatment/disposal information show no cause for concern considering the
POTVs current use/disposal practices.
2.4.1 Opportunities for Cost Savings
To provide a representation of sludge quality over a fixed duration,
sevage 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
pollutants, especially organics in sewage sludge, compositing samples provides
an opportunity to substantially lower analytical costs. Because sample
compositing provides a representation of average sludge quality, it is not an
appropriate technique to use when the entire range of sludge quality variation
is of interest.
Vhen interested in daily variation in sludge constituents, a POTV 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 POTVs,
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 2-4 shows the
recommended preservatives and maximum sample holding times for organic and
metal pollutants.
2-14
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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.
2.5 SAMPLE PREPARATION AND PRESERVATION
Errors of varying severity, which affect analytical determinations nay be
introduced during sample collection and storage. To avoid potential errors
and maintain sample integrity, POTV operators should carefully consider the
following:
Sample Container Material
Sample Container Preparation
Sample Preservation
Holding Time Prior to Analysis.
Table 2.4 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."
2.5.1 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 phenolic caps. These containers
should be fitted with Teflon liners for most parameters.
2.5.2 Sample Container Preparation
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 soap, thoroughly
2-15
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rinsed vith tap water, and then rinsed at least 3 times with distilled water
prior to air drying. Additional container preparations are described below:
Extractable Organics - Glass containers vith Teflon-lined caps only.
Containers are washed as above and solvent rinsed (typically methylene
chloride) and air dried.
Volatile Organics - Container preparation consists of vash and rinse
as described above followed by baking at 105°C for both vials and
septums. Cool in organic-free atmosphere.
Metals - Vash and rinse as described above. Then rinse with dilute
acid (1 part deionized and distilled water and 1 part HNO,) followed
by a final rinse with deionized and distilled water; followed by
redistilled water rinse.
2.5.3 Sample Preservation
Table 2.4 presents U.S. EPA 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:
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.
Vhenever possible, sample containers should be pre-preserved. Thus,
grab samples are preserved upon sampling and composite samples are
preserved during compositing.
In general, all samples should be chilled (4°C) during compositing and
holding,
For solid sludge (cake), adding chemical preservative is generally not
useful due to failure of the preservative to penetrate the sludge
matrix. Preservation consists of chilling to 4eC and sampling as
described in Section 2.3.
From the standpoint of maximizing sample characterization, as large a
sample as possible is desired. For manually composited samples, each
grab should be of a substantial volume (i.e. 1-2 liters). Upon
finishing the composite, the sample may be poured to a more con-
veniently sized, preserved container, following mixing.
2-16
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2.5.A Holding Time Prior to Analysis
Table 2.4 lists the maximum holding times for various pollutant samples.
Table 2.5 lists potential interferences that may affect samples during
shipping and storage. There are many more interferences associated with
analytical methods.
2.6 PACKAGING AND SHIPPING
Vhen analysis will be performed avay from the sampling locale, samples
must be packaged and transported.
2.6.1 Packaging
Sample containers must be packaged so as 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 4eC for
the duration of transportation.
2.6.2 Transportation Regulations
The following guidelines control the shipment of vastevater and sludge
samples:
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.
Vhen environmental samples are preserved as recommended, 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).
2-17
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TABLE 2.5. POTENTIAL INTERFERENCES ASSOCIATED WITH
SAMPLE SHIPPING AND STORAGE
Parameter
Interferences1
Preservative
Acidity
Ammonia
Cyanide
Chromium VI
Phenols
Silica
Sulfide
Sulfite
Organic Chemicals
C02 loss
Volatilization
Sulfides
Reducing agents
B2S, S02
Oxidizing agents
Aeration, agitation
Aeration, agitation
Photodegradation
Pill container completely
Na S20S
Pill container completely
Cd(NO,)24B20
Minimize holding time
Aerate
PeS04
Avoid freezing
Fill container completely
Fill container completely
Brovn glass container
10ther than those addressed by protocols shovn in Table 2.4
2-18
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TABLE 2.6. 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
Recommendation
Quantity of
Preservative Added
Per Liter
WT. % of
Preservative
Nl
i
Organic Carbon
Nitrogen Species
Metals, Hardness*
Nitrogen Species
HC1
HgCl2
HN03
H2S04
<2 - >1
N.A.
<2 - >1
<2 - >1
2 ml of 1:1
40 rag
5 ml of Cone. (70Z)
2 ml of 36N
0.04Z
0.004*
0.35Z
0.35Z
COD, Oil & Grease
P (hydrolyzable)
Organic Carbon
Cyanides
Phenolics
Biological -
Fish & Shellfish
Tissue**
NaOH
H3P04
Freezing
0°C
(Dry Ice)
<4 - >2
N.A.
2 ml of ION
Sufficient to
yield desired pR
N.A.
0.080X
N.A.
*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 vith cone.
HNO to pH<2. At time of analysis, sample container should be thoroughly rinsed vith
1:1 HN03; 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 vith dry ice, but each package must be plainly and durably marked on
at least one side or edge vith the designation ORM-A. Advance arrangements vhich must
be met to ship dry ice are found in DOT regulation 49 CFR 173.616.
-------
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 inventory for each sample lot and a
log book of sampling activities.
2.7.1 Sample Labeling
It is important that each sample label include the following information
(items in bold text are minimum elements):
Sampling Organization Name
Facility Mane (being sampled)
Bottle Number (specific to container)
Sample Number (specific to all containers comprising one sample)
Type of sample, i.e., grab, 24 hour composite, etc.
Date, Tine (24 hour tine is preferable, i.e., 1600 vs. 4:00 p.«.)
Sample Location
Preservatives
Analytical Parameter(s)
Collector
Special Conditions or Remarks.
Labels and ink should be waterproof. Fix labels to containers 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 lot 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 to the information
listed on each sample bottle, this document shall record each sample's
collection and handling history from time of collection until analysis. 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.
2-20
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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 considera-
tions 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 toxic substances present, but also because of the abundance of pathogens
(bacteria, viruses and worms). As a precautionary measure, innoculations are
recommended for all personnel vho have direct contact with sludge (as well as
any wastevater) samples. As a minimum, innoculation 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. Vash any cuts or
scrapes thoroughly and treat immediately.
Vhen sampling sludge in confined areas, particularly around anaerobic
digesters, a possibility exists for the presence of dangerous gases. 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 meters and backup
breathing apparatus.
2-21
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There are several universal safety precautions that are applicable to
sludge sampling as veil. 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 vhen 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.
2-22
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3. ANALYTICAL PROCEDURES
Sevage sludge analysis is difficult because of the inherent complexity of
sludge matrices. Sevage sludge is compositionally diverse, rich in organic
matter, and highly variable in physical and chemical properties. 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 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.
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, priority pollutant metals, priority
pollutant organics, and pathogenic organisms are discussed.
3.1 CONVENTIONAL POLLUTANT PARAMETERS
Conventional pollutant parameters have historically been the focal point
of sewage sludge analyses. The parameters normally associated with this group
include solids, pH, oil and grease, 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. Total cyanide, oil
and grease, pH, and solids analyses adapt readily to sludge matrices.
Existing Federal regulations (40 CFR Part 257) require POTVs that apply
sludge to food-chain croplands to measure the pH of the sludge-soil mixture
and soil cation exchange capacity (CEC). Soil pH should be measured using a
1:1 solution of soil and deionized water (see Table 3.1). For distinctly acid
soils, CEC should be measured using the summation method (see Table 3.1). For
3-1
-------
TABLE 3.1 ANALYTICAL TECHNIQUES FOR CONVENTIONAL POLLUTANTS
V
N>
Parameter
Phosphorous
(Ortho Phos)
(Total Phos)
Nitrogen
(Tot. Kjeldahl N)
Ammonia
Nitrate
Nitrite
Cyanide
Phenolics
Total Organic
Carbon
Chaidcal Oxygen
Demand
Preparation
Techniques
Acidic Digestion
Turbid samples
mist be filtered
after digestion
H2904 digestion
Colorimetric
reaction
Reaction to
brueline sulfate
Hydrazine or Cd
reaction
CN converted to
HCN by reflux-
distillation
Distillation and
extraction
Inorganic carbon
removal
Oxidation to
potassium dichro-
mate and HCl
Analytical
Technique
Colorimetric
Colorimetric
Colorimetric,
ion specific
electrode
Colorimetric
Colorimetric
Colorimetric
Colorimetric
Catalytic com-
bustion & non-
dispersive IR
Titration
Recommended
QA/QC
Blanks
Standards
Spike
Blanks
Standards
Spike
Blanks
Standards
Spike
Blanks
Standards
Spike
Blanks
Standard
Spike
Blate
Standard
Spike
Aqueous
Detection
Limit (mg/1)
0.001
0.05
0.05
0.1
0.05
0.02
0.002
1.0
5.0
Comments
- High iron concentration
can cause precipitation
and loss of phosphorous
- Turbidity interference
- 24 hr. holding time
- 24 Hr. holding time
- Fe + Cr catalyte; Cu
inhibits reaction
- Hg can cause complex to NB4
- Dissolved organic Matter
- Strong oxidizing
or reducing agents
- Suspended matter in
reduction coluan
- Samples vhich contain high
cone, of netals or organics
- Fatty acids and sulfides
interfere
- 24 hr. holding tlae
f\.1_i__ ,,,_,..., In mil
- Sulpnur compounds ana
oxidizing agents interfere
- Carbonate + bicarbonate
carbon interfere
- Possible loss of volatiles
- Chloride oxidation could
^M t.«tM».r>i«m»»
an intei lerence
Reference.
EPA6CO/4-79-020
365.1
EPA 600/4-79-020
351.1
350.1, 350.2, 350.3
352.1
353.1, 353.2
EPA 600/4-79-020
335.2
EPA 600/4-79-020
420.1
EPA 600/4-79-020
415.1
EPA 600/4-79-020
410.1 and 410.2
-------
TABLE 3.1 ANALYTICAL TBOTOQUES TOR ODNVENTKNAL POLLUTANTS (Continued)
V
u»
Parameter
Biochemical
Oxygen Demand
Oil and Grease
PH
CBC
CEC
Solids
Solids 7. (total)
Preparation
Techniques
Incubation
Solvent
extraction
Solution in
suspension with
DT water
Bad/treatment
andne extraction
/__« j i \
(acid exchange)
Ammonium acetate
ester action,
ignition
(base exchange)
Sodlun acetate-
sludge solution,
isopropylalcohol
wash, ammonium
acetate exchange
Filtration
Evaporation
Analytical I
Technique
Measurement of
reduction in
dissolved oxygen
Gravimetric IR
Analysis
Ion selective
electrode
Titration,
Golorimetric
Emission,
or absorption
spectrosoopy,
or equivalent
Gravimetric
Gravimetric
Aqueous
n4r. T>i.ljL>.r-.i.iu.»._.-i> r>ua> iu^1 tjlji
omuards uitetierciice iron solids
and oily residues
None cited None cited Acid soils
in Ref . in Ref .
One blank No data Neutral, saline, or
per sample available calcareous soils
batch
BLvks 4.0-10.0
BLrics K/A
Reference
EPA 600/4-79-020
405.1
EPA 600/4-79^020
413.1, 413.2
EPA 600/4-79-020
150.1
Black 1965
Black, 1965
p. 900, 57-4
Black, 1965 pp. 891-900
SV-846 Method 9031
EPA 60074-79-020
160.1-160.5
160.3
-------
neutral, saline, or calcareous soils, the sodium acetate method should be used
(see Table 3.1).
3.2 METALS
There are several analytical techniques used for determination of metals
in sewage sludge, vith 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 first involves determination of the total metal
content or other materials of interest, without regard for chemical form.
This approach has been used most frequently, and the analytical techniques for
such determinations are designed to solubilize all of the metal species (bound
to organic particulates and mineralogically bound). In the second approach
often referred to as "leachate approach," the proportion of the total contam-
inant loading which will become available or mobilized under environmental
conditions is determined. Thus, leachate techniques are designed to mimic a
given environmental scenario. Vith either approach, the complexity and
variability of sludge matrices has made the development of sample preparation
techniques a great analytical challenge.
The two primary aspects of metal determination in sewage sludge are
1) affecting the desired level of dissolution of the sample portbn 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 charac-
teristics.
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
3-4
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elevated temperature digestion procedures in combination vith chemical or
physical oxidants. The modifications which have been used include variations
in acids, oxidation reagents, physical oxidation techniques, reaction condi-
tions, and/or the sequence in which components are employed. Acids used most
frequently include nitric acid (HN03), hydrofluoric acid (HP), hydrochloric
acid (HCL), and perchloric acid (HCL04); vhile hydrogen peroxide and
perchloric acid are common oxidizing reagents. High temperature (550°C)
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 approaches have been used to estimate the amount of
inorganic and organic contaminants which may be released after disposal of
contaminated material. Both involve the leachate approach. The contaminated
material is maintained in an aqueous slurry under a given set of conditions,
after vhich contaminant levels are measured on the filtered aqueous media.
The first approach, called the elutriate test, was developed by the Army Corps
of Engineers to evaluate the impact of dredge disposal activities on the
aquatic environment. The second is part of the Extraction Procedure (EP)
toxicity procedure developed by EPA (in response to RCRA legislation) to
evaluate the impact of landfill waste disposal practices on subsurface and
surface waters (Federal Register 45: 5/19/80).
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 (SU-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 (ICP). Samples prepared by this
3-5
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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 vatch glass.
Beat the sample to 95° C and reflux for 10 to 15 min without boiling. Allow
»
the sample to cool, add 5 ml of concentrated HNO,, replace the watch glass,
and reflux for 30 min. Repeat this last step to ensure complete oxidation.
Using a ribbed vatch 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% H20}. 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.
A) 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 30X H20}.
(1) USEPA "TEST METHODS FOR EVALUATING SOLID WASTE: VOLUME 1A"
SV-846 3rd EDITION, NOVEMBER 1986. CHAPTER 3, PP. 3050-1,5.
3-6
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method may be analyzed by ICP for all the listed metals, or by FLAA or GFAA as
indicated belov:
FLAA GFAA
Aluminum Magnesium - Arsenic
Barium Manganese Beryllium
Beryllium Molybdenum Cadmium
Cadmium Nickel Chromium
Calcium Potassium Cobalt
Chromium Sodium Iron
Thallium Molybdenum Selenium
Copper Vanadium Thallium
Iron Zinc Vanadium
Lead
Method 3050 prepares samples for analysis total metals (except mercury)
determination through vigorous digestion in nitric acid and hydrogen peroxide
followed by dilution with either nitric or hydrochloric acid.
For the digestion and analysis procedures for mercury, 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 (ICP). The following discussion
generally describes both methods.
Inductively Coupled Argon Plasma is a form of optical emission spectros-
copy 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 and not strongly inhib-
ited by matrix variation, costs are moderate since many elements may be
determined at once, aand 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 ICP
instruments (more than $100,000).
3-7
-------
The basic principle behind atomic absorption spectroscopy is the opposite
of the emission method, ICP. In AAS the element (metal) being analyzed is
dissociated from its chemical bonds by heating the sample. It is then capable
of absorbing radiation until it reaches the excited state at a characteristic
wavelength. This affects the sensitivity in analyzing for elements via atonic
absorption because under optimum conditions, for every atom available in an
excited state there are many more available in a dissociated condition. For
this reason, AAS is more responsive than ICF to lover concentrations of metals
in sludge. However, this very precise nature of AAS is also the cause of its
major flawonly one elemental determination per sample is possible at a time.
Thus, the total analysis time of AAS is significantly greater than that of ICP
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 signifi-
cant technical advantage over the other. However, ICP'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 final
decision to individual POTVs.
Table 3.3 summarizes the relative advantages and disadvantages of ICP and
AAS.
ICP Method 6010
EPA recommends Method 6010 for the determination of metals in solution by
Inductively Coupled Plasma atomic emission spectroscopy (ICP). This method
can be found in the USEPA manual "Test Methods for Evaluating Solid Waste,"
(SV-846, Nov. 1986, 3rd Ed., Vol 1A, pp. 6010-1,17). The method is applicable
1For 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.
3-8
-------
TABLE 3.3 COMPARISON SUMMARY OF ICAP AND AAS
ICAP AAS
Cost for Instrument - +
Cost per sample + +
Detection Limits + +
Precision + +
Linear Vorking Range +
Sensitivity + +
Number of Elements/Sample +
Analysis Time +
- disadvantage
+ advantage
++extra advantage
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 vastes, require digestion prior to analysis. EPA recommends
digestion Method 3050 (SV-846, 3rd Ed. - see Section 3.2.2.1).
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 this method is restricted to spectroscopists who are
knowledgeable in the correction of spectral, chemical, and physical
interferences.
Atomic Absorption Methods
The USEPA recommends use of the methods listed in the manual "Test
Methods for Evaluating Solid Waste," (SV-846, Nov. 1986, 3rd Ed., Vol 1A) for
the determination of metals in solution by atomic absorption spectroscopy. A
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TABLE 3.4. RECOMMENDED INDUCTIVELY COUPLED WAVELENGTHS AND
ESTIMATED INSTRUMENTAL DETECTION LIMITS
Element
Wavelength* (nm)
Estimated Detection
Limit" (ug/L)
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Molybdenum
Nickel
Potassium
Selenium
Silicon
Silver
Sodium
Thallium
Vanadium
Zinc
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
196.026
288.158
328.068
588.995
190.864
292.402
213.856
45
32
53
2
0.3
5
4
10
7
7
6
7
42
30
2
8
15
See note c
75
58
7
29
40
8
2
*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.
bThe estimated instrumental detection limits 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.
cHighly dependent on operating conditions and plasma position.
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complete set of procedures for each metal-specific method may be found on
pages 7020-1 to 7950-3. These methods are simple, rapid, and applicable to a
large number of metals in drinking, surface, and saline vaters as veil as
domestic and industrial wastes. While drinking water free of particulate
matter may be analyzed directly, ground water, other aqueous samples, 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 inter-
ferences, the detection limits for typical sludge samples will be somewhat
higher.
Mercury Analysis
The physical-chemical characteristics of mercury are not amenable to
digestion by the generally recommended technique, Hethod 3050. For the
determination of total mercury (organic and inorganic) in soils, sediments,
bottom deposits, and sludge material, EPA recommends using Method 7471, 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.
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 characteristic of sewage
sludges often mean that analyte extraction/isolation procedures play a
significant role in the reliability of the resultant analytical data.
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TABLE 3.5. ATOMIC ABSORPTION CONCENTRATION RANGES
Direct Aspiration
Detection Limit
Metal (mg/L)
Aluminum
Antimony
Arsenic
Barium(p)
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum(p)
Nickel(p)
Potassium
Selenium
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
0.8
0.2
0.005
Sensitivity
(mg/L)
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
4
0.8
0.02
Furnace Procedure* ' c
Detection Limit
(ug/L)
3
1
0.2
0.1
1
1
1
1
__
2
1
4
NOTE: The symbol (p) indicates the use of pyrolytic graphite with the furnace
procedure.
* For furnace sensitivity values, consult instrument operating manual.
b Gaseous hydride method.
c The listed furnace values are those expected vhen using a 20-uL
injection and normal gas flow, except in the cases of arsenic and
selenium, vhere gas interrupt is used.
d Cold vapor technique.
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3.3.1 Overview of Analyte Extraction and Isolation
For a number of reasons, EPA has focused regulatory attention on two
categories of contaminants: volatile organics and extractable 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
POTV sludge sampling and analysis, EPA recommends tvo analytical methods
(1634, 624-S) which both extract via purge and trap (see Section 3.3.2.).
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.
Extractable 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
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polar solvent. Extraction techniques which are applicable to sludge and solid
matrices include:
Sonication extraction
Continuous liquid-liquid extractors
Soxhlet extraction
Mechanical agitation (shaker table, homogenization, or vrist-action
shaker).
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 extract-
able organics determinations including homogenization, 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.
Vrist-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.
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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 in broad spectrum applications include:
Silica gel adsorbent resins - fractionation and general purpose
cleanup
Florisil adsorbent resins - fractionation and general purpose cleanup
Alumina adsorbent resins - fractionation and general purpose cleanup
Activated carbon - fractionation and general purpose cleanup
Gel permeation resins - higher molecular weight biogenic organics
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."
3.3.2 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 vastevater treatment sludges:
Volatile Organic* - 624-S (EPA 1984b) or 1634 (EPA 1988a).
Seai^volatile Organics - 625-S (EPA 1984b) or 1635 (EPA 1988a).
Each of these two methods employ gas chromatography/mass spectrometry (GC/HS)
GC/HS is a combination of two microanalytical techniques: gas
chromatography (a separation technique) and mass spectrometry (an identifi-
cation technique). A sample aliquot is prepared for extraction, extracted^
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then introduced to the GC/MS system. The sample is vaporized quickly at an
elevated temperature and carried by an inert gas (mobile phase). The vapor-
ized sample is forced through a lined column (stationary phase). Separation
of the sample components is affected by their differential partitioning
between stationary and mobile phases. The separated components exit the
column and enter the mass spectrometer (MS) vhere 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 several
(3-5) analyte standard solutions of various concentrations (e.g.,20-160
ng/ml). The solutions are carefully 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:
Provides qualitative and quantitative information about a wide range
of organic compounds.
Confirms specific information from a small sample size.
Produces a spectrum with a fragmentation pattern, or fingerprint,
which can be used to identify an unknown.
3.3.2.1 Methods 1634 and 1635
Methods 1634 and 1635 are draft methods for analyzing volatile organics
(Method 1634) and base/neutral organics (Method 1635) in sludge. These
methods were developed by the USEPA Offie of Water Industrial Technology
Division, and are derived from previous methods 1624 and 1625 (see 40 CPR Part
136) for analyzing wastewaters.
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The 1634/1635 (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 to even
minute amounts. Methods 1634/1635 and 1624/1625 are similar in this respect
but differ in sample preparation.
Method 1634 sample preparation for sludge samples consists of the follow-
ing three routes, depending on the percent (X) 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 vater 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 1635 sample preparation for sludge samples consists of the
following three routes, depending on the percent (X) 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.
3.3.2.2 Methods 624-S and 625-S
Methods 624-S and 625-S are interim methods for the measurement of
organic priority pollutants in sludges. Method 624-S is used to analyze for
volatile organic compounds. Method 625-S is used for semi-volatile or
3-17
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nonvolatile organics. These test procedures vere derived from previously
developed methods 624 and 625 for analyzing vastevaters (see 40 CFR Part 136).
The 624-S/625-S techniques are conventional GC/MS and operate as described in
Section 3.3.2.
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 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 GC/MS
(HRGC/MS) is preferred since HRGC/MS allows easier data interpretation.
Vhile Methods 1634/1635 provide lower detection limits than Methods
624-S/625-S, these methods are also more costly. Presently, Methods 1634/1635
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. At this time, EPA recommends using
either set of methods.
Neither Methods 624-S/625-S or Methods 1634/1635 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
3-18
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megabore column pesticide analysis nationally. However, in particular
situations, megabore column analysis may be appropriate.
3.4 PATHOGENIC MICROORGANISMS
A pathogen or pathogenic agent'is any biological species that can cause
disease in the host organism (primarily man). These organisms fall into four
broad categories: viri, bacteria, parasites, and fungi. From these cate-
gories, species commonly found in sevage sludge include fecal coliforms, fecal
streptococci, salmonella, and ascaris. Vastevater 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 on September 13, 1979 (44 PR
53438-53468) under joint authority of Subtitle D of the Resource Conservation
and Recovery Act (RCRA) and Section 405(d) of the Clean Vater Act establish
acceptable practices for the disposal of solid waste which include sevage
sludge. The regulations (40 CPR 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 technology-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). Appendix II allows
methods or operating conditions other than those listed under PSRP or PFRP if
3-19
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pathogens and vector attraction are reduced commensurate with the reductions
attainable from listed methods. Appendix II does not prescribe the operation
mode (i.e., batch or continuous) for digesters.
Analytical techniques which have been used in sevage sludge applications
are summarized in Table 3.6. It should be noted that bacteria are tested for
(usually) via modified standard vastevater methods because there are no
definitive sludge methods. In addition, there are no standardized methods of
any kind for parasitic determinations.
The effectiveness of many PSRPs and PFRPs for reducing pathogens can be
estimated by 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. They make good control
tests.
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TABLE 3.6 tfWJTTICAL TBOWIQUES FDR CEnHHDWIGN OP P/OHOGENIC MKHXHM03C IN SEUMZ SLUXE
Pathogen
Preparation Technique
Culture Media
Conents
Reference
(it
Fecal Colifonn and Fecal
Streptococcus Indicator
ost practical
ethod
A,B
Klchsiella
Staphylococcus
Sanonella
MycobacteriiM
Clcstridiui
9iigella
Gam negative
enteric bacteria
Polio/Echo/
Coxsadcie viruses
E. coll
Leptrospires
Vibrio Chlorae
Sludge is vortex Mixed, soni-
cated, or hongenized serial
dilution in appropriate nedia
appropriate Media
eosine - oethylene blue agar
amitol salt agar
selenite-brilliant green agar
Niddlebrooks 7R11 agar
acetaride agar
differential reinforced
clostridia Media
xylose lysine deoxycholate agar
xylose lipine deoxycholate agar
Sludge is Mixed at pB 3.5 (BC1) tissue culture
with Aid,, centrifuged; viruses
eluted with UK beef extract
(pH 7.0). Eluted viruses
filtered flocculated in 3Z beef
extract of p3 3.5 to concentrate.
centrifugation and filtration
filtration
filtration
H-PC broth Uiuiie filters
Fletchers seal-solid edia
serial dilution in alkaline
peptone water (pH 9.0)
incubation at
for six weeks
incubation at 35"C
for 6-18 hours
C
C
C
C
C
C
tests with activated D,E
sludge yield
recoveries of 68-8QK
B (912E)
B(912F)
B (9L2C)
References: A) Bordher and Winter (eds.) (1978) "Microbiolcgic Methods for Monitoring the Environment-Water and Waste,"
ERMOO/8-78-017
B) APHA-AWA-VPCF (1980) Standard Methods for the Examination of Water and Uasteuater. 15th edition.
C) Dudley, D.J. et. al. (1980) "Enuneratlon of Potentially Pathogenic Bacteria Era Sewage Sludges" Applied and
Envinmental Microbiology 39: (1) p. 118-126.
D) Burst, C.J. et al. (1978) "Development of Quantitative Methods for the Detection of Bnterovtruses in Sewage
Sludge During Activation and Following Land Disposal" Applied and Environnental Microbiology 36: (1) p. 81-89.
E) "U.S. EPA Manual of Methods for Virology," EPA-600/4-84-013, February 1984, EM5L, Cincinnati, 51.
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4. QUALITY ASSURANCE
An essential part of a good sampling and analysis program is a veil
designed quality assurance (QA) program. The extent of the QA program should
mirror the intent and purpose of the sampling effort.
If the purpose of the sampling and analysis program is to determine
compliance with permit conditions, or to provide critical data for Baking a
major cost decision, then the QA program should be extensive and be able to
demonstrate the precision, accuracy, representativeness, comparability and
completeness of the data. The determination of these QA parameters and their
definitions are:
Accuracy of all sample testing and analyses should be evaluated at a
minimum frequency of 5 percent (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 quality control limits for accuracy of the analyses will be those
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 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 quality control limits for the precision of the analyses will be
those 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 should be determined and evaluated on the basis of data
sets for each measurement process. Completeness is calculated as a
percentage, based on the number of valid values obtained for each
measurement process relative to the number of valid values originally
anticipated. 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 for
analysis. All sampling will be conducted to ensure that the
analytical results are representative of ^he media and the conditions
being measured.
4-1
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Comparability is a more qualitative QA measurement. All analytical
data must be calculated and reported in units consistent vith 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 vill 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 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 O&M decisions, a simplified QA program which 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
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
4-2
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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. These are situations
(particularly for enforcement actions) in vhich more stringent protocols vill
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 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 vhich 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 external contam-
inants that may have been introduced into samples during collection.
One field replicate for every 20 samples or less should be collected at a
preselected POTV 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 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
4-3
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procedures should be used for the determination of precision, accuracy and
completeness. The QAPP 1983 document provides a description of the statis-
tical procedures and their applications. All reports of analytical data
should contain a separate section which assesses the quality of the reported
data.
The section of the quality assurance plan on internal quality control
checks specifically discuss hov the following activities vill be addressed:
Organic Priority Pollutants
Instrument tuning and calibration
Method blank analysis
Surrogate spike analysis
Hatrix spike/matrix spike duplicate analysis
Internal standards analysis
Inorganic Priority Pollutants
Initial calibration verification
Continuing calibration verification
Instrument response and linearity verification
Calibration and preparation blank analyses
Interference check sample analyses
Spike sample analyses
Duplicate sample analyses
Laboratory control sample analyses
Serial dilution analyses (if applicable)
Instrument detection limit determination
Method of standard additions application.
The sample procedures and frequency section of the quality assurance
plans should address, among other elements, sample holding times, sample
preservation procedures, and sample chain-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.
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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 1988.
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:
Type and Number of Samples
Number of Streams to be Sampled
Number of Facilities/Locations
Availability of Suitable Sample Points
Parameters to be Analyzed
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 twenty-four hour composite sampling, a minimum of two
shifts (more likely three) are required when automatic sampling devices cannot
be used. In addition to the manpower required to actually collect the sample,
additional time is required for sample preparation and handling.
5-1
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Estimates of some of these needs are presented belov:
Activity Manpower
Automatic Sampler Setup .5-4 manhours
Sample Container Preparation2 2-15 man-minutes
sample
Sample Documentation 2-15 man-minutes
sample
Sample Handling4 2-60 man-minutes
sample
Depending on sample point characteristics
Depending on parameter
Depending on parameter, ultimate data use and number of points sampled
simultaneously.
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 vill vary according to what extent the analytical load imposed by
the sludge sampling is marginal to the laboratory's operational capacity. Two
extremes serve as examples:
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, 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 ana-
lytical 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 labora-
tory manpower (any additional manpower needs can be accommodated by limited
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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 vide 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 Bust be analyzed in
light of applicable salary scales, sampling program complexity and in-house
analytical capabilities.
5.3 CONTRACT ANALYTICAL COSTS
Many sludge sampling programs, particularly those conducted by small
municipalities or authorities, will utilize contract laboratories for analyt-
ical work. In contrast to sampling costs, which vary greatly due to a vide
variety of factors, contract analytical costs fall vithin a relatively narrov
range. Table 5.1 presents typical analytical costs for parameters commonly
run on sludge samples. These cost estimates vere obtained in a March 1988
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 labora-
tories charge an additional fee for this preparation, vhich can be as much as
$100, depending on parameters to be run.
The second factor impacting analytical costs is the practice by most
laboratories of offering discounts on per sample prices for multiple sample
analysis. These discounts vary from laboratory to laboratory, and can be
substantial (20% or more) depending on the number of samples involved. Of
particular importance is the number of samples being received simultaneously
by the laboratory (i.e., a greater discount vill typically be offered for 10
samples if all are to be analyzed at one time rather than if one is to be
delivered to the lab each veek for 10 veeks).
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TABLE 5.1 TYPICAL CONTRACT ANALYTICAL COSTS FOR
COMMONLY ANALYZED PARAMETERS
Priority Pollutant Organics Sample Cost Range ($/Sample)
1634/1635 2200 - 24001
624-S/625-S 1800 - 22001
Priority Pollutant Metals
ICAP or AAS 25 - 2002
Conventional Pollutants
Oil & Grease 15 - 25
Nitrates, Nitrites 10. - 20
Ammonia, as Nitrogen 10 - 20
Total Kjeldahl Nitrogen 10 - 20
Total Suspended Solids, Total % Solids 10 - 20
Total Phosphorus 10 - 20
Digested Phosphate 10 - 50
Pathogenic Pollutants
Total Coliforms 20-45
Fecal Coliforms 20 - 45
Fecal Streptococci 20 - 45
Salmonella 20 - 45
Other
Cyanide 20 - 30
Phenols 20 - 30
Potassium 20 - 30
Total Organic Halides 50 - 100
Total PCBs 60 - 150
*re for complete priority pollutant analysis for organic pollutant
Cost is per metal and will vary depending on number of metals analyzed per
sample.
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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 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 parameters(s) to be analyzed. The following are typical
per-container prices for some commonly used containers:
Container Size
Teflon 1 liter
Graduated Glass
(v/Teflon-lined cap) 1 liter
Polypropylene 1 liter
Polypropylene 0.5 liter
Polypropylene 10 liter
Glass
(v/Teflon lined cap) 0.5 liter
Approx. Price Per
$ 35 - $40
$3.00 - $4.00
$2.00
$1.50
$15.00
<$1.00 - $2.00
As with analytical costs, suppliers of containers often offer sub-
stantial discounts for volume purchases.
Automatic Samplers - In most sludge sampling programs automatic sam-
pling equipment will be found to be unsatisfactory 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. Pneumatic-
ally 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
flov, 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 avail-
able for less than $10.
Preservatives - Reagent grade chemicals should be used as preserva-
tives. Since each sample will typically require very small amounts of
preservatives, cost on a per sample basis is negligible.
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6. REFERENCES
APHA-AWA-VPCF. 1976. Standard Methods for the Examination of Water and
Vastevater. Washington, D.C.: APHA-AWVA-WPCF.
Black, C.A. (ed.). 1965. "Methods of Soil Analysis, Agronooy 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, D.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, D.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 Wastevater 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 Coll forms, Total Coll forms, 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. 1979. 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 Bnvironaental Research Laboratory.
EPA. 1983b. Interim Guidelines and Specifications for Preparing Quality
Assurance Project Plans. PB83-170514, QAMS-005/80. Office of Research
and Development.
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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.
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
Sludge. Washington, D.C.: U.S. Environmental Protection Agency, Office
of Water Enforcement and Permits.
"Guidelines for Establishing Test Procedures for the Analysis of Pollutants,"
40 CFR Part 136 . Washington, D.C.: National Archives and Records
Administration, Office or 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, Disposal,
Reuse. New York: McGraw-Hill Book Company.
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APPENDIX A
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W.OLMOL
flmt
typ.
ft "*
So
o
a
Sourcei 1987 EPA Document
'Preparation Aid for HWKRL's Category II
Quality Assurance Project Plans"
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