hington, DC 20460
                              EPA 821-B-93-OO1
                             . June 1993
illance Mbhiforini

                          Printed on papsrtjiatcontains
                               ded fiber



        This report has been reviewed by the Analytical Methods Staff
   within the Engineering and Analysis Division of the EPA Office of Water.
Mention of trade names or commercial products does not constitute endorsement
                      or recommendation for use.



        This guidance document was prepared in response to questions directed to the Environmental
 Protection Agency (EPA) Headquarters by EPA Regions and various state agencies about monitoring
 compliance with the Organic Chemicals, Plastics, and Synthetic Fibers (OCPSF) Effluent Guideline
 Limitations promulgated by EPA in 1987.  The Engineering and Analysis Division (BAD) in EPA's
 Office of Science and Technology within the Office of Water is responsible for promulgation of
 regulations controlling the discharge of pollutants into surface waters.  BAD has developed analytical
 methods and collected and validated analytical data as part of the rulemaking process. To support
 compliance monitoring,  BAD provides assistance to the EPA Regions and the States in evaluating
 claims of matrix interference problems associated with OCPSF and other proposed and promulgated
        Recognizing that the guidance necessary to deal with these issues goes beyond the OCPSF
 Rule and beyond those Regions and States that have requested assistance, BAD has compiled this
 guidance under one cover for use by permit writers, permittees, laboratories, and other interested
 parties.  This document  is organized into six chapters:

              Data required to document matrix-related problems
              Guidance to analysts attempting to identify pollutants in OCPSF wastewaters
              Cost estimates for resolving matrix-related problems
              Guidance for review of data from EPA 600- and 1600-series methods for organic
              Case histories of claims of matrix interferences
              Contracting for analytical services

 This document addresses only those issues related to the analysis of organic compounds regulated
under the OCPSF rule, but much of the approach can be applied to the analysis of other organics as
well as to metals.
       This document presumes knowledge of, or access to, the relevant analytical methods under
discussion.  The authors have found it necessary to sacrifice some level of detail in order to address
as broad a range of situations as possible. Some analytical problems and some samples are not
addressed in these pages. However, the approaches used to demonstrate the magnitude of problems
with sample matrices can be applied to issues not specifically addressed here.
       EPA's Engineering and Analysis  Division is solely responsible for the content of this docu-
ment. The document was prepared, in part, by DynCorp Viar Inc., under U.S.  EPA Contract 68-DO-
0083. Comments,  suggestions, and requests for additional copies should be directed to:
                                   William A. Telliard, Chief
                                   Analytical Methods  Staff
                               Engineering and Analysis Division
                               Office  of Science and Technology
                             U.S. Environmental Protection Agency
                                   Washington, DC  20460


                         Table of Contents
Chapter 1
      Checklist of Laboratory Data Required to Support a Claim
      that the Permittee was Unable to Measure Pollutants
      Due to Matrix Problems 	
Chapter 2
      Guidance for Analysts Attempting to Identify and Quantify Pollutants
      in Wastewaters Discharged from Plants Manufacturing
      Organic Chemicals, Plastics, and Synthetic Fibers 	
Chapter 3
      Cost Estimates for Resolving Matrix Interferences

Chapter 4
      Guidance for Reviewing Data
      from the Analysis of Organic Compounds
      Using EPA 600- and 1600-Series Methods
Chapter 5
      Case Histories of Claims of Matrix Interferences
      Submitted Under the OCPSF Rule 	
Chapter 6
      Guidance on Contracting for Analytical Services


                                                                            Chapter 1

                                            Checklist of Laboratory Data Required
                            to Support a Claim that  the Permittee  was  Unable
                                 to Measure Pollutants Due to Matrix Problems

        The Federal Water Pollution Control Act (FWPCA) Amendments of 1972, later amended as
 the Clean Water Act (CWA), require that all facilities that discharge wastewaters to the surface waters
 of the United States maintain a permit for such discharges under the National Pollutant Discharge
 Elimination System (NPDES).  In addition, all such permitted dischargers (permittees) must monitor
 their effluent for compliance with any and all relevant federal and state discharge limitations.
        CWA Section 304(h) requires EPA to promulgate test procedures appropriate for the measure-
 ment of regulated pollutants, commonly known as "the 304(h) methods."  These methods are then
 published at 40 CFR Part 136.  Test procedures may also be promulgated by EPA under the authority
 of other CWA sections, and these procedures are typically incorporated in revisions of 40 CFR Part
 136.  For some inorganic analytes and some organic pesticides, the test procedures promulgated under
 Section 304(h) include methods sponsored by organizations other than EPA, such as the American
 Society for Testing and Materials (ASTM) and the U.S. Geological Survey (USGS).
        The permittee must use the 304(h) methods or methods promulgated in other regulations to
 demonstrate compliance with NPDES permit limitations. The 304(h) methods for non-pesticide
 organic compounds promulgated in 40 CFR Part 136 (49 FR 43234; October 26, 1984, and later
 corrections) are commonly referred to as the "600-series" and "1600-series" methods.  This chapter
"addresses issues related to the analysis of organic compounds, but much of the general approach can
 be applied to the analysis of metals and other inorganics as well.
        Table 1, at the end of this chapter, lists all of the 600- and 1600-series methods, indicating
 each method number, the general class of analytes to which each is applicable, the instrumentation
 required, and the regulatory status of each method (promulgated, proposed, or draft).  These methods
 were designed to be applicable to a wide range of industrial effluents and were used to generate the
 data necessary for the development of each of the effluent guidelines promulgated by EPA. Despite
 this wide applicability, EPA recognizes that some sample matrices may fail to yield useful results
 when these analytical methods are employed.  Therefore, EPA is prepared to consider claims that the
 effluent is compliant in those instances in which the effects of the  sample matrix make measurements
 difficult or impossible. All such claims must be supported by specific analytical data;  stating that "the
 sample could not be analyzed" is not acceptable documentation.
        This chapter outlines the analytical data and other information required by EPA to evaluate a
 permittee's claim of compliance when complex matrices preclude measurement of the pollutants listed
 in the permit.  The data required  are identical to those gathered by EPA in developing the regulation.
        Since different instrumentation provide different data (e.g., GC/MS procedures produce plots
 of mass intensities while GC  procedures do not), the specific form of the data will differ according to
 the method. The following numbered items describe the data required to support a claim of compli-
 ance at  a minimum.

Chapter 1: Checklist of Laboratory Data
Compliance Monitoring Guidance
1.     The method number of the base method used for the measurement.
              The methods required for NPDES compliance monitoring are specified in 40 CFR
       Part 136 (and elsewhere, as explained above).  Although there are many similarities between
       the technical details of methods from other EPA programs and from other sources, it is not
       acceptable to use such other methods for NPDES monitoring in place of a 304(h) method.
       For instance, methods from the Office of Solid Waste SW-846 manual are not acceptable in
       instances where a 304(h) method exists, unless approved by the permitting authority in ad-
              The 600- and 1600-series methods do provide flexibility to improve separations and
       reduce the costs of measurements, but method performance must not be sacrificed.  The
       purpose of this flexibility is to allow for improvements in analytical technology, in part to
       address matrix effects.  In order to invoke this flexibility, the analyst must start with one of
       the base 600- or 1600-series methods  and improve upon it. Example improvements include
       the use of additional cleanup techniques, alternative gas chromatography or liquid chromatog-
       raphy columns, and more specific detectors.
              Changing to an  alternative method for the sake of convenience is contrary to the spirit
       of this flexibility. The change must be within the scope of the method used and must be for
       the sake of improvement, and this improvement must be supported by data demonstrating
       equivalent performance  to that of the  base method.

2.     A detailed narrative discussing the problems with the analysis, corrective
       actions taken, and  the changes made to the base method identified.
              The permittee must also describe the reasons for the change to the base method, the
       supporting logic behind the technical  approach to the change, and the result of the change.
              Many compliance monitoring analyses are performed by contract laboratories on
       behalf of the permittee.  However, the responsibility for providing the information to EPA
       rests with the permittee. The permittee must therefore impress upon its contract laboratories
       the need for detailed technical communication of problems encountered and solutions at-
       tempted.  The narrative should be authored by an analytical chemist and written in terms that
       another analytical chemist can understand.

 3.    A summary level report or data  reporting forms giving the pollutants  for
       which analyses were conducted and the concentrations detected. For the
       pollutants that were not detected, the detection  limits or estimated detection
       limits must be provided.
               Such results must be provided for each field sample analyzed, including any dilutions
       and reanalyses.
   *           If not specified in the base method, the means for estimating detection limits must be
       provided in the narrative.  If the laboratory uses "flags" in its data reporting, the definition of
        each flag must be provided with the data.

Compliance Monitoring Guidance
Chapter 1: Checklist of Laboratory Data
4.     A summary of all quality control results required by the base method.

               These results include, but are not limited to, the following:

              Instrument tuning
              Calibration verification
              Initial precision and recovery
              Ongoing precision and recovery
              Matrix spike matrix spike duplicate results
              Surrogate recoveries
              Labeled compound recoveries (isotope dilution methods only)
              Blank results
              Quality control charts and limits

5.     Raw data that will allow an independent reviewer to validate each deter-
       mination and  calculation performed by the laboratory.

               This validation should consist of tracing the instrument output (peak height, area, or
       other signal intensity) to the final result reported.  The raw data are method specific and may
       include any of the following:

              Sample numbers or other identifiers used by the both the permittee and the laboratory
              Extraction dates
              Analysis dates and times
              Sequence of analyses  or run logs
              Sample volume
              Extract volume prior to each cleanup step
              Extract volume after each cleanup step
              Final extract volume prior to injection
              Digestion volume
              Titration volume
              Percent solids or percent moisture
              Dilution data, differentiating between dilution of a sample and dilution of an extract or
              Instrument(s) and operating conditions
              GC and/or GC/MS operating conditions,  including detailed information on
                     columns used for determination and confirmation (column length and dia-
                     meter, stationary phase, solid support, film thickness,  etc.)
                     analysis conditions (temperature programs, flow rates, etc.)
                     detectors  (type, operating conditions, etc.)
              Chromatograms, ion current profiles, bar graph spectra, library search results
              Quantitation reports, data system  outputs, and other data to link the raw data to the
               results reported.  (Where these data are edited manually, explanations of why manual
               intervention was necessary must be included)
              Direct instrument readouts; i.e., strip charts, printer tapes, etc., and  other data to
               support the final results
              Laboratory bench sheets and copies of all pertinent logbook pages for all sample
               preparation and cleanup steps, and for all other parts  of the determination

Chapter 1:  Checklist of Laboratory Data
Compliance Monitoring Guidance
             The raw data required shall be provided not only for the analysis of samples, but also
       for all calibrations, verifications, blanks, matrix spikes and duplicates, and other QC analyses
       required by the base method.  Data must be organized so that an analytical chemist can
       clearly understand how the analyses were performed.

       Example  calculations  that will allow the data reviewer to determine how the
       laboratory used the raw data to arrive at the final results.
              Useful examples include both detected compounds and undetected compounds.  If the
       laboratory or the method employs a standardized reporting level for undetected compounds,'.
       this should be made clear in the example, as should adjustments for sample volume, dry
       weight (solids only), etc.

       For GC/MS and other instruments involving data systems, the permittee
       should be prepared to submit raw data on magnetic tape or disk, upon
       request by EPA.
8.     The names, titles, addresses, and telephone numbers of the analysts who
       performed the analyses and of the quality control officer who will verify the
              If data are collected by a contract laboratory, it is the permittee's responsibility to see
       that all of the requirements in the methods are met by the contract laboratory and that all data
       listed above are provided.  (See Chapter 6 for guidance on writing contracts for laboratory

               Table 1.  600- and 1660-Series Methods for Organics1
Class of Analytes
Purgeable Halocarbons
Purgeable Aromatics
Acrolein and Acrylonitrile
Hexachlorophene and Dichlorophen
Phthalate Esters
     1 Please note that other methods for the analysis of organic compounds are incorporated by
 reference in 40 CFR 136.

Compliance Monitoring Guidance
Chapter 1: Checklist of Laboratory Data
           Table 1. 600- and 1660-Series Methods for Organics (cont.)
Class of Analytes
Organochlorine Pesticides/PCBs
Nitroaromatics and Isophorone
Polynuclear Aromatic Hydrocarbons
Chlorinated Hydrocarbons
Organophosphorus Pesticides
Organophosphorus Pesticides
Chlorinated Herbicides
C, H, and O Pesticides
Organohalide Pesticides/PCBs
Chloropicrin and Ethylene
Triazine Pesticides
Carbamate and Urea Pesticides
Organophosphorus Pesticides
Purgeable Organics
Base/Neutral and Acid Extractable
Acrolein and Acrylonitrile
Dinitroaniline Pesticides
Dithiocarbamate Pesticides
Dithiocarbamate Pesticides
Benomyl and Carbendazim
Carbamate and Urea Pesticides
Napropamide, Propanil, and Vacor
Organonitrogen Pesticides
HPLC/UV, Fluorescence
Low Resolution GC/MS
UV/Vis, by CS2 liberation
GC/Hall, by CS2 liberation

Chapter 1: Checklist of Laboratory Data
Compliance Monitoring Guidance
           Table 1.  600- and 1660-Series Methods for Organics (cont.)
Class of Analytes
Neutral Nitrogen-Containing
Thiocarbamate pesticides
Biphenyl and Orthophenyl Phenol
Amine Pesticides
Dinitro Aromatic Pesticides
Organochlorine Pesticides/PCBs
Polychlorinated Dibenzo-p-dioxins
and Dibenzofurans
Organochlorine Pesticides/PCBs,
Organophosphorus Pesticides, and
Phenoxy-Acid Herbicides
Volatile Organics
Semivolatile Organics
Organic Halides (OX) in Solids
Organic Halides (OX) in Solids
Adsorbable Organic Halides (AOX)
in Wastewaters
Total Oil and Diesel Oil in Drilling
High Resolution GC/MS
Isotope Dilution
GC/MS Isotope Dilution
GC/MS Isotope Dilution
Neutron Activation
Combustion, Coulometric
Carbon Adsorption, Com-
bustion, and Coulometric
Retort, Gravimetric
Draft, 1/91
Draft, 1/91
Draft, 1/91
    2 Draft Method 1618 has been supplanted by Methods 1656, 1657, and 1658.

Compliance Monitoring Guidance
            Chapter 1: Checklist of Laboratory Data
             Table 1.  600- and 1660-Series Methods for Organics (cont.)
Class of Analytes
Oil and Grease by Solid-Phase
Chlorinated Phenolics in Wastewater
Diesel Oil in Drilling Muds
Organohalide Pesticides
Organophosphorus Pesticides
Phenoxy-Acid Herbicides
Pyrethrins and Pyrethroids
Solid-Phase Extraction,
GC/MS Isotope Dilution
Draft 12/91
Draft, 12/91
Draft, 12/91
   2 Draft Method 1618 has been supplanted by Methods 1656, 1657, and 1658.

To obtain copies of the 600-series methods, write    To obtain copies of the 1600-series methods,
or call:                                         write or call:
       Chemical Research Division
       USEPA Environmental Monitoring
       Systems Laboratory
       26 Martin Luther King Blvd.
       Cincinnati, OH  45268
       USEPA Sample Control Center
       (operated by Viar & Co.)
       P. O. Box 1407
       Alexandria, VA 22313

Note:  Some 1600-series methods listed as
"draft" may not be available through the Sample
Control Center.
   Additional information on analytes, methods, and regulatory limits may be found in EMMI, the
   EPA Environmental Monitoring Methods Index, a computerized database linking 50 EPA
   regulatory lists, 2600 substances, and 926 analytical methods. For information on obtaining
   the EMMI system software, contact:

          National Technical Information Service
          5825 Port Royal Road
          Springfield, VA  22161

          Specify item number PB92-503093


                                                              	Chapter 2

                                  Guidance for Analysts Attempting  to Identify
                                        and Quantify Pollutants in Wastewaters
                                          Discharged from  Plants Manufacturing
                            Organic Chemicals, Plastics, and Synthetic Fibers

       This chapter provides guidance to analytical chemists having difficulty in analyzing complex
wastewaters from facilities that manufacture organic chemicals, plastics, and synthetic fibers.  This
guidance illustrates how the method equivalency and flexibility permitted by the wastewater methods
can be used to apply other analytical techniques to matrix problems. This guidance specifically
addresses the determination of the organic pollutants in these wastewaters.  Conventional pollutants
and metals are not addressed because few problems have been encountered in measuring these
analytes in these wastewaters.
       Table 2, at the end of this chapter, lists the organic priority pollutants regulated in waste-
waters from organic chemicals, plastics, and synthetic fibers (OCPSF) industries and the EPA
analytical methods relevant to monitoring such wastewaters.

Approved Methods for  Determination of Organic Pollutants
       Section 304(h) and other  sections of the CWA authorize the EPA Administrator to promulgate
test procedures for monitoring pollutants in wastewater discharges.  Analytical methods  (test proce-
dures) to monitor organic priority pollutants in wastewater were proposed  on December 3,  1979 (44
FR 69494) and promulgated in 40 CFR Part 136 on October 26, 1984 (49  FR 43234). These methods
are variously known as the 304(h) methods, the 600-series methods, the 1600-series methods, and the
Cincinnati methods.  Additional methods have been proposed and/or promulgated under Section
304(h) since 1984.  The 304(h) methods for organics are listed in Chapter 1, Table 1.  Information on
obtaining copies of these methods may be found at the end of that table.
       The approved methods are based on recovery of organic pollutants from a wastewater sample
by a purge-and-trap technique or  by extraction with an organic solvent such as methylene chloride.
In the purge-and-trap technique, the pollutants are purged from water with an inert gas and trapped on
a sorbent column.  The sorbent column is then heated and back-flushed to desorb the pollutants into a
gas chromatograph (GC). The pollutants are separated by the GC and detected by a conventional
detector (CD) or by a mass spectrometer (MS). Conventional detectors  include the flame ionization
detector (FID), electron capture detector (BCD), electrolytic conductivity detector (ELCD), and
nitrogen-phosphorous detector (NPD).
       Pollutants extracted from wastewater with an organic solvent are concentrated by evaporation
of the solvent, and a portion of the concentrated extract is injected into a GC or high performance
liquid chromatograph (HPLC), where the pollutants are  separated and detected by a CD or MS. For
application  of GC  and HPLC methods, EPA classified the organic pollutants into twelve groups of
similar chemical and physical properties allowing each group to be measured under a given set of
chromatographic conditions. Through the use of different detectors, several methods may be ap-
plicable to each  of the twelve groups of pollutants.  Table 3 lists the 304(h) methods applicable to

Chapter 2:  Guidance for Analysts
.  Compliance Monitoring Guidance
monitoring those pollutants specifically regulated under the OCPSF Rule, provides the general class
of analytes to which the method is applicable, and specifies the applicable instrumentation.

Flexibility in  Analytical  Methods
       In promulgating analytical methods for measurement of pollutants, EPA has provided flexibil-
ity for dealing with interferences.  The major flexibility options are discussed in the preamble to the
40 CFR Part 136 methods (49 FR 43234).  These options include a mechanism for obtaining approval
of an alternative test procedure on a nationwide basis and/or on a site-specific basis (40 CFR Parts
136.4 and 136.5).  These procedures are intended to encourage development of new analytical
methods and to give analysts a number of options for resolving analytical problems that may be
unique to specific wastewaters.  If the discharger or an interested third party wishes to pursue the
option of an alternative test procedure, that party should apply to the Director of the Environmental
Monitoring and Support Laboratory in Cincinnati, Ohio, for approval of an nationwide alternative
procedure, or should apply to the State or Regional EPA permitting office for approval of a limited
       In addition to the flexibility provided by the options above, flexibility is permitted in each
analytical method. The analyst is permitted to "improve separations or lower the costs of analyses"
provided that the results obtained are not less precise and accurate than the results obtained using the
unmodified method.  For example, the analyst is allowed to use professional judgment in selecting
packed or open tubular columns, operating temperature programs, carrier gas or solvent flow rates,
and detectors. Analysts may  also use their discretion in selecting cleanup procedures  and extract
concentration procedures.  The flexibility permitted is outlined in each method and in the preamble to
the regulation.
       EPA believes that method flexibility, which is discussed further below, should permit pol-
lutant identities .and concentrations to be determined in nearly all wastewaters, but recognizes that
there may be a few intractable sample matrices that do not yield readily to extensive analytical efforts.
EPA is anxious to learn of the steps taken by the analyst, the solutions found, and the instances in
which a given matrix does not yield to known analytical techniques. Stating that  "the sample couldn't
be analyzed" is not sufficient  and will not be accepted as justification for a claim  of matrix  inter-

Demonstrating Equivalency with a Given  Method
       The objective in modifying a method is to make it more specific for a given pollutant, more
sensitive, more precise, more accurate, or in some other way to  improve the method. However,
some laboratories have interpreted the provision to modify a method as a means of increasing the
speed of analysis, thus reducing the analysis time, or to take other "shortcuts" to  reduce cost, result-
ing in a compromise of method performance.  In regulating the wastewater methods, EPA needed a
means to preclude this compromise in performance, yet permit the flexibility that would improve
method performance.
       EPA resolved this issue by providing limited flexibility within the methods, so that improve-
ments could be made, and requiring the analyst to demonstrate that the results produced by any


Compliance Monitoring Guidance
Chapter 2: Guidance for Analysts
modification would be equal to or better than results obtained with the unmodified method.  The
yardsticks by which this performance is to be measured are precision and accuracy, but can be
extended to include detection limit, gas chromatographic resolution, mass spectral resolution, and
other measures of method performance.  The spirit of the regulation concerning methods is  that
method performance must be improved by any modification, and must not be degraded by such a
       The laboratory must perform a start-up test prior to practicing a method, and the results of the
start-up test must be  on record at the laboratory for inspection by EPA if desired. The start-up test
provides  an initial validation of the performance of the method by a specific laboratory.  It is de-
scribed in detail in Section 8 of the 600-series and 1600-series wastewater methods and is also used in
the Office of Drinking Water 500-series methods and the Solid Waste SW-846 methods.  The test
consists of an analysis of four replicate volumes of reagent water spiked with the pollutants  of interest
at the concentration specified in the method or at 5-10 times the detection limit  of the method.
       For each analyte, the precision of the analysis of the four replicates, as determined by the
standard  deviation of the four measurements, must be less than the standard deviation specified in the
method.  Similarly, for each analyte, the accuracy of the analysis of the four replicates, as determined
by the average percent recovery of the four measurements, must fall within the  range of percent
recovery specified in the method.  If either the precision or accuracy test is failed, the test must be
repeated  until the laboratory is able to meet the precision and accuracy requirements.
       If the laboratory modifies  a method, the start-up test must be repeated with the modification
as an integral part of the method.  The laboratory must demonstrate that the precision and accuracy
specifications in the method can be met with the modification; otherwise, the modification is not
permitted.  The laboratory must maintain records that document that the start-up test was performed
on the modified method and that the precision and accuracy requirements were met.

Examples of Solutions to Matrix  Problems
       The inability to measure the concentration of a pollutant in a specific wastewater is  often
attributed to  "matrix problems."  Some example solutions to matrix problems are described below.
The list is not exhaustive but should help the analyst to examine the specific matrix problems at hand
and then to develop solutions to such problems.

Volatile Organic  Pollutants
1.     Use  of selective GC detectors
               The  304(h) methods for volatiles include Methods 601, 602, 603, 624, and  1624.
       The effluent limits in the OCPSF regulation are all greater than 10 jtg/L.  The selective GC
       detectors in Methods 601  and 602 cover all OCPSF volatile pollutants regulated, and allow
       detection at levels well below the effluent limits in the OCPSF regulation.  The specificity
       provided by  the electrolytic conductivity detector and by the photoionization detector allow
       detection of the halogenated and aromatic analytes, respectively, in complex matrices.

Chapter 2:  Guidance for Analysts
Compliance Monitoring Guidance
2.     Micro-extraction and gas chromatography with selective detectors
               The selective GC detectors in Methods 601 and 602 provide sensitivity that is 10-100
       times greater than that required to detect the analytes of interest.  Some of this sensitivity can
       be used to substitute micro-extraction in place of purge-and-trap.  The advantage of micro-
       extraction is that the pH of the water can be adjusted to attempt to keep the interferences in
       the water while the analytes of interest are extracted.1

3.     Sample dilution
               Methods 601 and 602 can achieve method detection limits of less than 1 jtg/L for all
       volatile analytes in the OCPSF regulation, and of less than 0.1 /tg/L for many of these
       analytes.  The added sensitivity of the selective GC detectors can be used to overcome matrix
       problems by diluting the sample by a factor of 10-100. Even with this dilution, the pollutants
       can be detected at the levels required, and the effects of the interferences will be reduced or

4.     Isotope dilution
               Method 1624 employs stable, isotopically labeled analogs of the pollutants as internal
       standards in the analysis. The use of these labeled compounds frequently permits the pol-
       lutant to be determined in the presence of interferences because the unique spectrum of the
       labeled compound can be located in the presence of these interferences, and the pollutant can
       then be located  by reference to the labeled compound.

Semivolatile Organic Pollutants
1.     Use of selective GC detectors
               Methods 604 through 612 employ gas chromatography with selective detectors and
       high-performance liquid chromatography with an ultraviolet (UV) or electrochemical detector
       to detect pollutants in the presence of interferences.  In addition, Method 604 employs deriva-
       tization and a halogen-specific detector for the determination of phenols.  As with volatiles,
       the added sensitivity of the selective detectors permits the sample to be diluted by a factor of
       10-100 while allowing detection of the analytes  at the effluent limits specified in the  OCPSF

2.     pH change
               A very  powerful means of separating the pollutants of interest from interferences is to
       adjust the pH of the sample to keep the interferences in solution while allowing the pollutants
       to be extracted  in an organic solvent. For example, neutral pollutants can be extracted at
       either low or high pH. Therefore, if the main interferences are acidic, the pH can be adjusted
    1 Rhodes, J.W., and Nulton, C.P., /. Env. Sci. and Health, vol. A15, no. 5, (1980).

Compliance Monitoring Guidance
                                                           Chapter 2:  Guidance for Analysts
       to > 13 and the acidic interferences will remain in the water as their salts while the neutral
       pollutants are extracted using an organic solvent.
               Phenol and 2,4-dimethylphenol can be extracted at high pH (11-13) using continuous
       liquid/liquid extractors, as described in Method 1625.  This permits phenol and 2,4-dimethyl-
       phenol to be extracted in the presence of other, stronger acids.2
               In a manner analogous to the pH change described above, the extract from the pri-
       mary extraction can be back-extracted with water of the opposite pH to remove other inter-
       ferences.  To keep the organic pollutants in the extract, the water used for back-extraction can
       be saturated with salt (sodium sulfate and/or sodium chloride).  Aqueous solutions containing
       2% of each of these salts have been shown to be effective in keeping the pollutants of interest
       in the extract.
Gel-permeation (size-exclusion) chromatography
       This technique is described in Revision C of Method 1625.  The same technique is
used in the Superfund Contract Laboratory Program (CLP) methods and SW-846 methods,
and has been shown to be effective for removing lipids and high-molecular-weight interferen-
ces that can degrade GC and mass spectrometer performance.

Solid-phase extraction (SPE) cartridge
       Although not fully evaluated at this time, SPE cleanup appears promising for not only
neutral species but also for acidic and basic species.  It has been shown to be effective in
removing interferences from extracts containing pesticides and in the extraction of pollutants
from drinking waters by Method 525. 3

Florisil, alumina, and silica  gel
       These adsorbents are effective in separating neutral species from polar interferences.
For polar analytes of interest,  the adsorbent must be evaluated to determine if the analyte will
be recovered.  The level of activation of the adsorbent plays a major role in this recovery

Isotope dilution
       Method  1625 permits determination of pollutants in the presence of interferences in
semivolatile samples in the same way described for volatiles above.  In addition, the wide
range of recovery of the labeled analogs permitted hi the method allows good quantitation of
the pollutant when interferences reduce the efficiency of the extraction.
   2 Jackson, C.B. et. al., /. Env. Sci. and Health, vol. A15, no. 5, (1980).

   3 Tessari, J.D., 12th Annual EPA Conference on Analysis of Pollutants in the Environment,  Norfolk,
Virginia, May 1989 (copies of the proceedings may be available through the EPA Sample Control Center, P. O.
Box 1407, Alexandria, VA 22313, 703-557-5040).


Chapter 2: Guidance for Analysts
Compliance Monitoring Guidance
Determination  of Phenol as a Specific  Example

       Phenol is a commonly occurring pollutant in OCPSF wastewaters.  The protocols below are
suggested as approaches to the determination of phenol in a complex sample matrix. After a protocol
has been found to be effective, the laboratory must demonstrate that the modification has equivalent
performance to the original method.  This demonstration involves the start-up tests described above.
The specifications in the original method must be met before proceeding with analysis of a sample for
compliance monitoring.

1.     Base/neutral extraction, acid back extraction, and isotope dilution GC/MS (based on Method

       1.1    Measure 1.0 L of well-mixed sample into a graduated cylinder and spike with labeled
              phenol per Section 10 of Method 1625. Stir and equilibrate per this method.  Quan-
              titatively transfer the sample to a continuous liquid/liquid extractor.  Adjust the pH of
              the sample to 11-13 and extract with methylene chloride as described in the method.

       1.2    Remove the extract from the extractor and place in a 1-2 L separatory funnel.  Back-
              extract the extract sequentially three tunes with 500-mL portions of salt-saturated
              reagent water (pH  <2), discarding the reagent water after each back-extraction.

       1.3    Concentrate the extract to 10 mL and clean up using gel-permeation chromatography
               (GPC) per Section 10 of Method 1625.

       1.4    After GPC, concentrate the extract to 0.5 mL and analyze by isotope dilution GC/MS,
               as described in Method 1625.

       1.5     Calculate the recovery of labeled phenol and compare to the performance specifica-
               tions in Method 1625.

2.     Dilution, acid extraction, back-extraction with base, derivatization, silica gel cleanup, and gas
       chromatography with an electrolytic conductivity detector (based on Method 604)

       2.1     Measure two 100-mL aliquots of well-mixed sample into 1000-mL graduated cylin-
               ders. Spike one of the aliquots with phenol at the level specified in Section 8 of
               Method 604. This aliquot serves as the matrix spike sample specified in the method.
               Dilute both aliquots to 1.0 L with reagent water. Adjust the pH of each aliquot to
               less than 2 with HC1.

       2.2    Pour each aliquot into a separate 1-2 L separatory funnel  and sequentially extract
               three tunes with methylene chloride per Method 604.  Discard the aqueous phase and
               return the extract to the separatory funnel.

        2.3    Back-extract the extract sequentially three tunes  with salt-saturated reagent water, dis-
               carding the reagent water after each back extraction.

        2.4    Concentrate, derivatize, and clean up the extract per Method 604.

Compliance Monitoring Guidance
Chapter 2:  Guidance for Analysts
       2.5    Analyze using the electrolytic conductivity detector.  This detector is less susceptible
               to interferences than the electron capture detector used in Method 604, Newer models
               have sensitivity nearly equivalent to the electron capture detector.

       2.6    Calculate the recovery of phenol in the matrix spike aliquot and compare  this recovery
               to the specifications in Method 604.

Chapter 2:  Guidance for Analysts
Compliance Monitoring Guidance
            Table 2.  Priority Pollutants Regulated under the OCPSF Rule
Priority Pollutant
Carbon tetrachloride
1 ,2,4-Trichlorobenzene
1 ,2-Dichloroethane
1 ,1 ,1 -Trichloroethane
1 ,1 ,2-Trichloroethane
1 ,2-Dichlorobenzene
1 ,3-Dichlorobenzene
1 ,4-Dichlorobenzene
1 ,1-Dichloroethylene
1 ,2-trans-Dichloroethylene
1 ,2-Dichloropropane
1 ,3-Dichloropropylene
Applicable 304(h)
610, 625, 1625
603, 624, 1 624
602, 624, 1624
601, 624, 1624
602, 625, 1625
612, 625, 1625
612, 625, 1625
601, 624, 1624
601, 624, 1624
612. 625, 1625
601, 624, 1624
601, 624, 1624
601, 624, 1624
601, 624, 1624
604, 625, 1625
601, 602, 612,
624, 625, 1625
601, 602, 612,
624, 625, 1625
601, 602, 612,
624, 625, 1625
601, 624, 1624
601, 624, 1624
604, 625, 1625
601, 624, 1624
601, 624, 1624
604, 625, 1625
609, 625, 1625
609, 625, 1625
602, 624, 1624
610, 625, 1625
Priority Pollutant
Methylene chloride
Di-/7-butyl phthalate
Diethyl phthalate
Dimethyl phthalate
Vinyl chloride
304(h) Methods
601, 624, 1624
601, 624, 1624
612, 625, 1625
610, 625, 1625
609, 625, 1625
604, 625, 1625
604, 625, 1625
604, 625, 1625
604, 625, 1625
604, 625, 1625
606, 625, 1625
606, 625, 1625
606, 625, 1625
606, 625, 1625
610, 625, 1625
610, 625, 1625
610, 625, 1625
610, 625, 1625
610, 625, 1625
610, 625, 1625
610, 625, 1625
610, 625, 1625
610, 625, 1625
610, 625, 1625
601, 624, 1624
602, 624, 1624
601, 624, 1624
601, 624, 1624

Compliance Monitoring Guidance
Chapter 2: Guidance for Analysts
                   Table 3.  304(h) Methods for OCPSF Organics
Class of Analytes
Purgeable Halocarbons
Purgeable Aromatics
Acrolein and Acrylonitrile
Phthalate Esters
Nitroaromatics and Isophorone
Polynuclear Aromatic Hydrocarbons
Chlorinated Hydrocarbons
Purgeable Organics
Base/Neutral and Acid Extractable
Volatile Organics
Semivolatile Organics
GC/MS Isotope Dilution
GC/MS Isotope Dilution


                                                                            Chapter 3

                                                                         Cost Estimates
                                                 for Resolving Matrix Interferences

       Most of the options for resolving matrix interferences are outlined in Chapter 2. The costs
associated with such options vary from laboratory to laboratory, as do the costs of the basic analysis.
However, EPA has provided some guidance in Table 4 on the likely added costs of the work required
to overcome such matrix interferences.  These estimates are based on EPA's experience in contracting
for analytical services.
       The costs are estimated for repetitive routine monitoring of a given waste stream. The esti-
mates do not include the development costs involved hi modifying a given method to overcome a
complex matrix problem. The cost estimates also do not include the costs of validating the use of
additional cleanup techniques through the "start-up" tests described in Chapter 2.  The costs of
method modifications cannot be estimated because each complex matrix problem must be evaluated
individually.  EPA believes that these development costs could range between several hundred and
several thousand dollars, depending on the complexity of the wastewater and the experience of the
laboratory in resolving matrix interferences.
       Given these difficulties, EPA believes that the prudent course is to begin by applying the
cleanups and other techniques described hi Chapter 2 to the existing 304(h) methods before embarking
on a major modification of a method.  The cost estimates in Table 4 are based on EPA's experience
through 1992 and are given in round numbers.

Chapter 3: Cost Estimates
Compliance Monitoring Guidance
       Table 4.  Estimated Incremental Costs Associated with Cleanup Techniques
                 and Other Approaches to Resolving Matrix Interferences1




Interference-reducing technique
Use of GC with selective detector in place
of GC/MS
Micro-extraction after pH adjustment
Sample dilution
Isotope dilution GC/MS (Method 1 624)
Use of GC with selective detector in place
of GC/MS
pH change
Gel permeation cleanup
Solid phase extraction cleanup
Florisil column cleanup
Alumina column cleanup
Silica gel column cleanup
Sample dilution
Isotope dilution GC/MS (Method 1 625)
Estimated incremental cost
No increased cost:
should be less expensive than GC/MS
No charge if known prior to analysis of neat
sample, otherwise may be billable as anoth-
er analysis
$200 to $500
No increased cost:
should be less expensive than GC/MS
No charge
No charge if known prior to analysis of neat
sample, otherwise may be billable as anoth-
er analysis
$200 to $500
     The techniques listed in this table are discussed hi Chapter 2.

                                                              	Chapter 4
                                                     Guidance  for Reviewing Data
                                      from the Analysis of Organic Compounds
                                    Using EPA 600- and 1600-Series Methods
       This chapter provides guidance for reviewing data submitted for compliance monitoring
purposes under the National Pollutant Discharge Elimination System (NPDES) and data submitted to
EPA and State authorities under the Clean Water Act. This guidance is intended to aid in review of
data for organic compounds regulated under the OCPSF Rule and collected using the 600-series and
1600-series wastewater methods under 40 CFR Part 136 (49 FR 43234).  The principles of data
review described herein are also applicable to data from the 500-series methods and the SW-846
       The guidance is technically detailed and is intended for data reviewers familiar with the 600-
and 1600-series methods and similar analytical methods. Reviewers unfamiliar with these methods
should review the methods and the supporting background materials provided in the preamble to the
regulation (49 FR 43234).

Standardized Quality Assurance/Quality Control
       In developing methods for the determination of organic pollutants in wastewater, EPA sought
scientific and technical  advice from many sources,  including EPA's Science Advisory Board,  scien-
tists at EPA's environmental research laboratories, scientists in industry and academia, and scientists,
managers,  and legal staff at EPA Headquarters.  The result of discussions held among these groups
was the standardized quality assurance and quality control (QA/QC) approach that is an integral part
of the 600- and 1600-series methods. This QA/QC takes the form of performance  specifications for
each, method and contains the following elements:
        1.      Purity and traceability of reference standards
       2.      Number of calibration points
       3.      Linearity of calibration
       4.      Calibration verification
       5.      Method detection limit (MDL) or rninimum level
       6.      Initial precision and recovery
       7.      Analysis of blanks
       8.      Recovery of analyte spikes into the sample matrix or
              Recovery of labeled compound spikes into samples (Methods 1624  and 1625).
       9.      Statements of data quality for recovery of spikes of analytes  or labeled compounds
              into samples
        10.    Ongoing precision and recovery (Methods 1624 and 1625)
        11.    Statements of data quality for the laboratory

Chapter 4: Data Review
Compliance Monitoring Guidance
       In reviewing data submitted for compliance, the permit writer or other individual or organi-
zation has the authority and responsibility to assure that the test data submitted contain the elements
listed above;  otherwise, the data can be considered noncompliant.

Provision  of QA/QC Data
       Permittees and other organizations submitting test data under the CWA or other acts may use
their own laboratories or contract the testing to laboratories that meet the requirements specified in the
methods.  The permit writer can require that the supporting QA/QC data described above be submit-
ted with results or that it be on record at the permittee's facility or at the testing laboratory.
       EPA  strongly suggests that the supporting QA/QC data be submitted along with the analytical
results, so that the quality of the data can be evaluated directly,  and so that these supporting data are
not lost between the time of submission of the analytical results  and the time that the QA/QC data are
       In many of its early analytical programs,  EPA relied upon laboratories to maintain records of
the QA/QC data. This practice was cumbersome for the laboratories, because many of the QA/QC
data were common to the analytical results for a variety of clients.  Retrieving these data from the
laboratory to  resolve questions of permit compliance was time-consuming for the permittee and the
permit writer. More importantly, this practice occasionally resulted in unscrupulous laboratories
failing to perform the necessary QA/QC testing, or performing the QA/QC testing "after the fact" to
satisfy an audit or data submission request.  In particular, many laboratories did not perform the
initial precision and recovery test (the "start-up" test) prior to practice of the method and did not
perform a spike of the analytes into the sample matrix to prove that the method would work on a
particular sample. Therefore, while the data provided by those  laboratories may have been valid,
there  was no  way to prove their validity.
       When collecting data for the development of a regulation, EPA requires that the supporting
QA/QC data  be provided along with the results for the sample analyses. If an individual or organi-
zation submits analytical results for inclusion into EPA's regulations, EPA similarly requires the
submission of the QA/QC data.  The sample results are evaluated relative to the QA/QC specifica-
tions  in the method, and those results that pass the QA/QC requirements are included for consi-
deration. EPA believes that provision of the QA/QC data at the tune of submission of the analytical
results is essential to the timely  and effective evaluation of permit compliance issues.

Details of Data Review
       The details of the data review process depend to a great extent upon the specific analytical
methods being employed for compliance monitoring. Even for data from the same methods, there are
probably as many specific approaches as there are reviewers. However, given the standardized
QA/QC requirements of the 600- and 1600-series EPA methods, a number of basic concepts apply.
The following sections provide the basic details for reviewing data submitted and provide some of
EPA's rationale for the QA/QC tests.

Compliance Monitoring Guidance
Chapter 4: Data Review
       Purity and Traceability of Reference Standards
               The accuracy of any non-absolute empirical measurement is dependent on the refer-
       ence for that measurement.  In determining pollutants in water or other sample matrices, the
       analytical instrument and analytical process must be calibrated with a known reference mate-
       rial.  The 600- and 1600-series analytical methods, as well as other EPA methods, require
       that the standards used for calibration and other purposes be of known purity and traceable to
       a reliable reference source.
               The ultimate source for reference materials is typically EPA  or the National Institute
       for Standards and Technology (NIST, formerly NBS).  Permittees and their supporting
       laboratories submitting analytical data must be able to prove traceability of the reference
       standards used in the analysis to EPA or NIST.  The proof of this traceability is a written
       certification from the supplier of the standard.
               Documentation of the purity and traceability of the standards need not be provided
       with every sample analysis.   Rather, it should be maintained on file at  the laboratory and
       provided on request. When analyses are conducted in a contract laboratory, such documen-
       tation ought to be provided to the permittee the first time that a laboratory is employed for
       specific analyses and then updated as needed.

       Number of Calibration Points
               The 600-series methods specify a minimum of three calibration points.  The lowest of
       these points is required to be near the MDL.  The highest is required to be near the upper
       linear range of the analytical system, and the third point is approximately midway between the
       two.  Methods 1624 and 1625 require calibration at five specific concentrations for nearly all
       analytes, and three or four specific concentrations for the remaining analytes for which the
       methods are not as sensitive.
               The lowest calibration point should never be greater than five times the MDL and
       should ideally be within three times the MDL.  The results for the lowest calibration standard
       are the principal means by which to assure that measurements at levels near the MDL are
               The flexibility in selecting the levels of the calibration points in the 600-series meth-
       ods has led to a wide variety of calibration ranges as each laboratory may determine its own
       calibration range. Some laboratories establish a relatively narrow calibration range, for
       instance a five-fold increase in concentration, because it makes it simpler to meet the linearity
       specifications of the  600-series methods. Other laboratories choose wider calibration ranges
       in order to minimize the number of samples that have to be diluted and reanalyzed because
       the concentration of  one or more analytes exceeds the calibration range.
               The data reviewer must make certain that all measurements are within the calibration
       range of the instrument.  Samples with analytes outside of the calibration range should have
       been diluted and reanalyzed.  The diluted sample results need only apply to those analytes that
       were out of the calibration range in the  initial analysis. In other words, it is acceptable to use
       data for different analytes from different levels of dilution within the same sample. Some

Chapter 4: Data Review
                                                                    Compliance Monitoring Guidance
       flexibility may be exercised in acceptance of data that are only slightly above (< 10%) the
       calibration range. Such data are generally acceptable as calculated.
               If data from an analysis of the diluted sample are not provided, limited use can be
       made of the data that are above the calibration range (> 10%). The response of the analytical
       instrument to concentrations of analytes will eventually level off at concentrations  above the
       calibration range. While it is not possible to specify at what concentration this will occur
       from the calibration data provided, it is generally safe to assume that the reported  concen-
       tration above the calibrated range  is a lower limit of the actual concentration.  Therefore, if
       concentration above the calibration range is also above  a regulatory limit, it is highly likely
       that the actual concentration would also be above that limit.

3.     Linearity of Calibration
               The relationship between the response of an analytical instrument to the concentration
       or amount of an analyte introduced into the instrument  is referred to as the "calibration
       curve."  An analytical instrument can be said to be calibrated in any instance in which an
       instrumental response can be related to a single concentration of an analyte. The response
       factor (GC/MS methods) or calibration factor (GC, HPLC methods) is the ratio of the re-
       sponse of the instrument to the concentration (or amount) of analyte introduced  into the
               While the shape of calibration curves can be modeled by quadratic equations or higher
       order mathematical functions, most analytical methods  focus on a calibration range where the
       response is essentially a linear function of the concentration of the analyte. The advantage of
       the linear calibration is that the response factor or calibration factor represents the slope of the
       calibration curve and is relatively constant, simplifying the calculations and the  interpretation
        of the data. Therefore, all the  600- and 1600-series methods specify some criterion for
        deterrnining the linearity of the calibration curve. When this criterion is met, the calibration
        curve is sufficiently linear to permit the laboratory to use an average response factor or
        calibration factor, and  it is assumed that the calibration curve is a straight line that passes
        through the zero/zero calibration point.  Linearity is determined by calculating the relative
        standard deviation (RSD) of the response factor or calibration factor for each analyte and
        comparing this RSD to the limit specified in the method.  If the RSD does not exceed the
        specification, linearity is assumed.
                In the 600- and 1600-series methods, the linearity specification varies from method to
        method, depending on the quantitation technique.  The typical limits on the RSD  are as
              15% for the gas chromatography (GC) and high-performance liquid chromatography
                (HPLC) methods

              35% for analytes determined by the internal standard technique in the gas chromatog-
                raphy/mass spectrometry (GC/MS) methods (624,  625, 1624, and 1625)

              20% for analytes determined by isotope dilution in Methods 1624 and 1625

Compliance Monitoring Guidance
Chapter 4:  Data Review
               If the calibration is not linear, as determined by the RSD of the response factor or
        calibration factor, a calibration curve must be used;;  This means that a regression line or
        other mathematical function must be employed to relate the instrument response to the con-
        centration.  Properly maintained and operated lab instrumentation should have no difficulty in
        meeting linearity specifications for 600- and 1600-series methods.
               For determination of nearly all of the organic analytes using the 600- and 1600-series
        methods, the calibration curves are linear over a concentration range of 20-100 times the
        nominal concentration, depending on the detector being employed.  Whatever calibration
        range is used, the laboratory must provide the RSD results by which one can judge linearity,
        even in instances where the laboratory is using a calibration curve.  In instances where the
        laboratory employs a curve rather than an average response factor or calibration, the data
        reviewer should review each calibration point to assure that the response increases as the
        concentration increases.  If it does not, the instrument is not operating properly, or the
        calibration curve is out of the range of that instrument, and data are not considered valid.

4.      Calibration Verification
               Calibration verification involves the analysis of a single standard, typically in the
        middle of the calibration range, at the beginning of each analytical shift. The concentration of
        each analyte in this standard is determined using the initial calibration data and compared to
        specifications in the method. If the results are within the  specifications, the laboratory is
        allowed to proceed with analysis without recalibrating and use the initial calibration data to
        quantify sample results.
               Calibration verification, used in the 600- and 1600-series methods, differs in concept
        and practice from "continuing calibration," which is  used  in the CLP and SW-846 methods.
        In continuing calibration, a standard is analyzed and new response factors or calibration
        factors are calculated on the basis of that analysis. If the  new factors are close to the average
        from the initial calibration, all subsequent sample analyses are conducted using the new
        response or calibration factors. The degree of "closeness" is generally measured as the
        percent difference between the old and new factors.  The  problem with continuing calibration
        is that it amounts to a daily single-point calibration.  Information about the behavior of the
        instrument at concentrations above and below this single standard can only be inferred from
        the initial multiple-point calibration.
               Specifications for calibration verification are generally given as either a range of
        concentrations or as a percentage difference from the test  concentration.  For the 600-series
        semivolatile GC and HPLC methods, the difference must  be within 15%. For Method 625,
        the difference must be within  20%. For the GC and GC/MS methods for volatiles and for
        Method 1625, a range of concentrations is given for each analyte.  These ranges are based on
        interlaboratory method validation studies.
               If calibration is cannot be verified, the laboratory may either recalibrate the instru-
        ment or prepare a fresh calibration standard and make a second attempt to  verify calibration.
        If calibration cannot be verified with a fresh calibration standard, the instrument must be

Chapter 4: Data Review
Compliance Monitoring Guidance
       recalibrated. If calibration is not verified, subsequent data are considered to be invalid until
       the instrument is recalibrated.

       Method Detection Limit or  Minimum Level
               The 600- and 1600-series methods do not require that laboratories determine the
       method detection limit (MDL) for each analyte (40 CFR Part  136, Appendix B).  However,
       laboratories that wish to practice any method on a routine basis must prove that they can
       measure pollutants at the MDL or the detection limit specified in the method.  Performance of
       an MDL study in accordance with this procedure  is one means of demonstrating such profi-
               The ability to identify and quantify compounds at the  "minimum levels" specified in
       Methods 1624 and 1625 must  be demonstrated prior to the practice of these methods. The
       minimum level for any compound is the concentration in a sample that is equivalent to the
       concentration of the lowest calibration standard in the initial calibration,  assuming that all
       method-specified sample weights, volumes, and procedures are employed.  Therefore, data
       from the initial calibration must be submitted in order to demonstrate that the required sen-
       sitivity has been achieved.
               If the minunum level in Methods 1624 and  1625 have not been achieved (as exempli-
       fied by calibration data), data  are considered to be invalid.

       Initial Precision and Recovery
               This test is required prior to the use of the method by the laboratory.  It is  sometimes
       termed the "start-up test." The laboratory must demonstrate that it can meet the specifications
       hi the method for the recovery of analytes spiked into a reference matrix (reagent water).
       EPA's experience has been that laboratories that have difficulty passing the start-up test have
       such marginal performance that they will have difficulty in the routine practice of the method.
       Performing the start-up test "after the fact" is not acceptable and may not be used to validate
       data that have been considered invalid because the start-up test was not performed.
               The test consists of spiking the analytes of interest into a set of four aliquots of
       reagent water and analyzing these four aliquots.  The mean concentration and the standard
       deviation of the concentration are calculated for each analyte  and compared to the
       specifications hi each method. If the  mean and standard deviation are within the limits, the
       laboratory can use the method to analyze field samples. For  some methods, a repeat test is
       allowed because of the large number of analytes being tested  simultaneously.
               If there are no start-up test data, or if these data fail to meet the specifications in the
       method, all data produced by  that laboratory using that method are not considered valid.  As
       with the documentation of the purity of the standards, the start-up test data need not be
       submitted with each set of sample results, but  should be submitted the first time a laboratory
       is employed for analyses, and updated as changes to the method necessitate (see below).
               It is important to remember that if a change is made to a method, the  start-up test
       must be repeated with the change as an integral part of the method.  Such changes  may

Compliance Monitoring Guidance
Chapter 4: Data Revfew
       involve alternative extraction, concentration, or cleanup processes, alternative GC columns,
       GC conditions, or detectors,  or other;steps designed to address a particular matrix problem.
       If the start-up test is not repeated when these steps are modified or added, any data produced
       by the modified method are considered not valid.

       Analysis of Blanks
               Blanks are required to be analyzed on a routine basis, when any part of the analytical
       process has been changed, and when contamination of the laboratory is suspected.  The 600-
       and 1600-series  methods require that a blank be prepared and analyzed with each set of
       samples.  The size of a "set"  is usually limited to a maximum of 20 field samples.  In practice
       this means that on each day that a laboratory prepares samples, they must also prepare a
       blank, even if fewer than 20  samples are prepared.  The purpose of analyzing a blank with
       each set of samples is to determine the extent of possible contamination of the samples while
       in the laboratory.  If the blank is handled by the same analysts in the same way as the samples
       and the blank shows no contamination, it is likely that the samples will not have been con-
       taminated. Requiring a blank be analyzed after the analytical process has been changed is
       consistent with requiring a repeat of the start-up test, because the change introduces a new
       possibility for contamination of samples through the use of the new procedures.
               Contamination hi the  laboratory is a common problem, though there are many opin-
       ions on what constitutes contamination.  In the 600- and 1600-series methods, any con-
       centration of a compound above the detection limit or minimum level of the method in
       question is a potential cause for concern. In reality, it is not unusual to find low levels of
       common laboratory solvents,  phthalates, and other ubiquitous compounds in laboratory
               Controlling laboratory contamination is an important aspect of each laboratory's
       quality assurance plan.  The laboratory should maintain records, typically in the form of
       control charts, of blank contaminants.  These records should prompt corrective action by the
       laboratory, including reanalysis of any affected samples.  Such control charts may be re-
       quested by the reviewer in evaluating sample results; however, they are not routinely sub-
       mitted with sample data.
               Unfortunately, by the time that data on contaminants are submitted, it is usually too
       late for corrective action.  Therefore, the reviewer has several options in making use of the
       sample data.  First, if a contaminant is  present in a blank, but not present in a sample, then
       there is little need for concern about the sample result, though it may be useful to occasionally
       review the raw data for samples without the contaminant to  ensure that the laboratory did not
       edit the results for this compound.
              The second approach  deals with instances where the blank contaminant is also report-
       ed in a sample.  Some general guidance will help you determine the degree to which the
       contaminant is affecting sample results:

             If the sample contains the contaminant at levels of at least 10 tunes that in the blank,
              then the  likely contribution to the sample from the contaminant in the laboratory

Chapter 4: Data Review
                                                           Compliance Monitoring Guidance
       environment is at most 10%.  Since most of the methods in question are no more
       accurate than that level, the possible contamination is negligible.

      If the sample contains the contaminant at levels of at least. 5 times but less than 10
       tunes the blank result, the compound is probably present in the sample, but the nu-
       merical result should be considered an upper limit of the true concentration.

      If the sample contains the contaminant at levels below 5 times the level in the blank,
       there is no adequate means by which to judge whether or not the sample result is
       attributable to laboratory contamination.  The results for that compound in that sample
       then become unacceptable for compliance monitoring.
       There are two difficulties in evaluating sample results relative to blank contamination.
First, the reviewer must be able to associate the samples with the correct blanks.  For analysis
of volatiles by purge-and-trap techniques, where no sample extraction is required, the blanks
and samples are associated by analysis date and time, and specific to the instrument as well.
For methods involving the extraction of organic compounds from the samples, the blanks and
samples are primarily associated by the date on which they were extracted, and by the batch
of samples and associated lab equipment (glassware, reagents, cleanup media).
       The second difficulty involves samples that have been diluted.  The dilution of the
sample with reagent water or the dilution of the extract with solvent represents an additional
potential source of contamination that will not be reflected in the results for the blank unless
the blank was similarly diluted.  Therefore, in applying the 10-times rule, the concentration of
the sample is compared to the blank result multiplied by the dilution factor of the sample or
sample extract. For instance, if 12 ppb of a contaminant are found in the blank, and the
associated sample extract  was diluted by a factor of 6 relative to the extract from the blank
prior to analysis, then the sample result would have to be greater than 12x6x 10, or 720 ppb,
to be acceptable.  Between 360 ppb and 720 ppb, the sample result would best be considered
an upper limit of the  actual  concentration.  Below 360 ppb, the sample result is not acceptable
for compliance monitoring.
        Many laboratories would have the reviewer believe that subtracting the concentration
of the analyte in the blank from the concentration of the analyte in the sample is a reliable
method of determining the true concentration of the analyte in the sample.  Unfortunately,
experience indicates that this practice is not reliable.   The obvious problem occurs when the
blank concentration is higher than that in the sample,  and subtraction would yield a negative
concentration value.  Using the  10-times rule above provides a more appropriate means of
evaluating the results and does not require that the reviewer alter the results reported by the

 Recovery of Analyte Spikes  into the Sample Matrix or Recovery of Labeled Com-
 pound Spikes into  Samples (Methods  1624 and 1625)
        The non-isotope dilution methods require a spike of the analytes of interest into a
 second aliquot of the sample for analysis with the sample. The purpose of spiking the sample
 (often termed a "matrix spike") is to determine if the method is applicable to the sample in

Compliance Monitoring Guidance
                                                                           Chapter 4: Data Review
       question.  The majority of the 600- and 1600-series methods were developed for the analysis
       of effluent samples and may not be apprbpriate for in-process samples.  While many of the
       methods were tested using effluents from a wide variety of industries, samples from some
       sources may not yield acceptable results.  It is therefore important to evaluate method perfor-
       mance in the sample matrix of interest.
               If the recovery of the matrix spike is within the limits specified in the method, then
       the method is judged to be applicable to that sample matrix. If, however, the recovery of the
       spike is not within the recovery range specified, either the method does not work on the
       sample, or the sample preparation process is out of control.
               If the method is not appropriate for the sample matrix, then changes to the method are
       required.  Matrix spike results are necessary in evaluating the modified method.  If the
       analytical process is out of control, the laboratory must take immediate corrective action
       before any more samples are analyzed.
               To separate indications of method performance from those of laboratory performance,
       the laboratory should prepare and analyze a  quality control check standard consisting of a
       spike of the analytes in reagent water.  If the results for the quality control standard are not
       within the range specified, then the analytical system must be repaired and the sample and
       spiked sample analyses repeated.  If the recovery of this spike is within the range specified,
       then the analytical process is judged to be in control.  However, the results of the sample
       analysis cannot be accepted for regulatory compliance purposes because the matrix spike
       results indicate that the method is not applicable to the sample.
               In evaluating matrix spike results, the data reviewer must verify the following:

The unspiked sample has been analyzed.
The spiked sample has been analyzed.
The recovery of the spike is within the range specified.
If the spike recovery is not within the range specified, a QC check standard
has been analyzed.
If a QC check standard has been analyzed, the results are within the range
              For isotope dilution analyses, the evaluation of the data is simpler because isotopically
       labeled analogs of the pollutants are spiked into each sample, and because a QC check stan-
       dard (termed the "ongoing precision and recovery standard," or OPR) is analyzed with each
       sample set.
              If the recovery of the labeled compound spiked into the sample is not within the range
       specified in the method, and the results of analysis of the ongoing precision and recovery
       standard are within the respective limits, the sample results are considered invalid.  When
       labeled-compound recoveries are outside of the method specifications, the problem may be
      .related to the  sample matrix.  The isotope dilution methods specify that, in these instances,
       the sample must be diluted with reagent water and reanalyzed.  If the labeled compound
       recoveries meet the method specifications after dilution of the sample, then the results are
       acceptable, although the sensitivity of the analysis will be decreased by the dilution.

Chapter 4: Data Review
                                                                   Compliance Monitoring Guidance
               Unfortunately, for some sample matrices, even dilution will not resolve the problem,
       and for other matrices, the loss of sensitivity will preclude the use of the results for deter-
       mining compliance.  In these instances, additional steps need to be taken to achieve acceptable
       results.  Guidance as to what steps may be taken when the results of matrix-spike or labeled-
       compound recoveries are not within the limits specified in the methods is provided in Chap-
       ter 2.  This guidance consists of suggestions for more extensive extraction and cleanup proce-
       dures, for sample dilution, and for other measures that can be taken to overcome matrix
               Using either non-isotope dilution or  isotope dilution techniques, in instances where
       matrix spike or labeled compound recoveries are  not within the specifications, it may still be
       possible to use the sample results for compliance monitoring purposes.  In particular, if (1)
       the recovery of the spiked compound is above the method specifications and (2) the compound
       is not detected in the sample analysis,  it is unlikely  that the compound is present in the
       sample.  This is because the factors that caused the  analysis to over-estimate the concentration
       in the spiked sample would not likely have resulted in an under-estimate in the unspiked
       sample.  For samples in which the compound is detected but the matrix spike or labeled
       compound recovery is above the method specifications, the concentration reported in the
       unspiked sample is likely an upper limit of the true concentration.

 9.     Statements of Data Quality  for Recovery  of Spiked Analytes or Labeled Compounds
        in Samples
                The 600- and 1600-series methods specify that after the analyses of five spiked
        samples, a statement of data quality is constructed for each analyte. The statement of data
        quality for each analyte is computed as the mean percent recovery plus and minus two times
        the standard deviation of percent recovery for each analyte.   The statements of data quality
        should then be updated by the laboratory after each five to ten subsequent spiked sample
                For non-isotope dilution results, the statement of data quality can be used to estimate
        the true value of a reported result and to construct  confidence bounds around the result.  For
        example, if the result reported  for analysis of phenol is 25 /*g/L, and the statement of data
        quality for phenol is 70% 30% (i.e., the mean recovery is 70% and  the standard deviation
        of the recovery is 15%), the true value for  phenol  will be in the range of 28-43 /*g/L,  with
        95%  confidence. This range is derived as follows:

                Lower limit =  [(25 * 0.7) - (25  X  0.3)]  =   [35.7  - 7.5] =28 pg/L
                Upper limit =  [(25 - 0.7) + (25  x  0.3)]  =   [35.7  + 7.5] =43 pg/L

                Many laboratories do not provide the data  quality statements with the sample results,
         in which case the data reviewer must determine if the data quality statements are being
         maintained for each analyte and may  need to obtain the data. If necessary, the reviewer can
         construct the data quality statement from the individual data points.

Compliance Monitoring Guidance
Chapter 4-: Data
               Statements of data quality for isotope dilution methods are based on the recoveries of
       the labeled compounds. Using an isotope dilution method, the sample result has already been
       corrected for the recovery of the labeled analog of the compound.  Therefore, for a reported
       result for phenol of 25 /ig/L where the standard deviation of the labeled phenol recovery is
       15%, the true value for phenol will be in the range of 17-32 /ig/L, with 95% confidence,
       derived as follows:

               Lower limit  = [25 - (25 x  0.3)]    =  17 /ig/L
               Upper limit  = [25 + (25 x  0.3)]    = 32 /tg/L

               The lack of a statement of data quality does not invalidate results but makes some
       compliance decisions more difficult. If statements of data quality are not being maintained by
       the laboratory, there may be increased concern about both specific sample results and the
       laboratory's overall quality assurance program.

10.    Ongoing Precision and Recovery (Methods 1624 and 1625)
               Methods 1624 and  1625 require that an "ongoing precision and recovery"  (OPR)
       standard be analyzed with each sample set, and that the results of this standard meet the
       acceptance criteria in the method prior to the analysis of blanks and samples.
               The data reviewer must determine if the ongoing precision and recovery standard has
       been run with each sample set and if all criteria have been met. If the standard was not run
       with a given set  of samples, or if the criteria are not met, the results for that set of samples
       are considered not valid.
               For volatiles analyses by Method 1624, the OPR analysis is associated with the
       samples on the basis of the analysis date and time and the specific GC/MS system. For
       semivolatile analyses by Method  1625, OPR results are associated with samples extracted at
       the same time as the OPR.
               Because  of the large number of compounds being tested simultaneously in the 600-
       and 1600-series  methods, there is a small probability that the OPR analysis will occasionally
       fail to  meet the specifications.  While the laboratory is supposed to correct any problems and
       analyze another  OPR aliquot, it may still be possible to utilize the data associated with an
       OPR aliquot that does not meet all of the method specifications.
               For  instance, if the concentration of a compound in the OPR is above the method
       specifications but that compound is not detected in an associated sample, then it is unlikely
       that the sample result is affected by the failure hi the OPR. If the concentration in the OPR is
       below  the method specifications but that compound is detected in an associated sample, then
       the sample result is likely a lower limit of the true concentration for that compound.

11.    Statements of  Data Quality for the Laboratory (Methods 1624 and 1625)
               In addition to statements  of data quality for results of analyses of the labeled com-
       pounds spiked into the samples, Methods 1624 and 1625 require that statements of data

Chapter 4: Data Review
Compliance Monitoring Guidance
       quality be constructed from the initial and ongoing precision and recovery data.  The purpose
       of these statements is to assess laboratory performance in the practice of the method, as
       compared to the assessment of method performance made from the labeled compound results
       for the samples.  Ideally,  the two statements of data quality would be the same.  Any dif-
       ference is attributable to either random error or sample matrix effects.
               If the laboratory is practicing isotope dilution methods, the data reviewer should
       review the statements of data quality for the laboratory.  If the laboratory does riot make these
       statements available for the reviewer, they may be requested.  If the laboratory still does not
       make them available, it does not necessarily invalidate any data, but indicates that the labora-
       tory may not be following the method as written.

                                                                	Chapter 5
                                                                           Case Histories
                                                  of Claims of Matrix Interferences
                                                  Submitted Under the OCPSF Rule
       Chapter 1 described the data that would be required to demonstrate that a matrix problem
precluded the measurement of a pollutant regulated under a NPDES permit limitation.  This chapter
provides case histories of selected claims of matrix interference problems submitted by dischargers
regulated under the OCPSF rule.
       Since 1991, the Engineering and Analysis Division (BAD) of EPA has reviewed data provided
by at least 15 dischargers regulated under the categorical pretreatment standards for the OCPSF
industry.  In each instance, the discharger claimed that the facility's wastewater could not be moni-
tored for compliance with the pretreatment standards because of interferences.  BAD was asked to
review such claims of matrix interferences by either the Region or State with permitting authority for
the facilities in question.  The various guidance documents collected here under one cover are an
offshoot of the efforts to review such claims.
       EAD's review focused on each facility's alleged inability to determine the organic analytes in
its wastewater because of interferences.  This chapter presents 11  case histories of EAD's review  of
data submitted by dischargers claiming interference problems and provides further detail as to how
these dischargers might resolve matrix interference problems.  None  of the dischargers nor any of the
laboratories involved are identified in this document.
       Prior  to reviewing the data, each of the permitting authorities was provided with copies of the
following draft guidance documents:

            Draft Checklist of Laboratory Data Required to Support a Claim that the Permittee
              was Unable to Measure Pollutants Due to Matrix Problems .(the "Checklist," updated
              as Chapter 1 of this report)

            Draft Guidance for Analysts Attempting to Identify and Quantify Pollutants in Was-
              tewaters Discharged from Plants Manufacturing Organic Chemicals, Plastics, and
              Synthetic Fibers (the "Guidance for Analysts," updated as Chapter 2 of this report)

            Draft Guidance for Permit Writers and Others Reviewing Data from the Analysis  of
              Organic Compounds Determined using the 600- and 1600-series Methods (the "Guid-
              ance for Permit Writers," updated as Chapter 4 of this report)
       It was EAD's intention that these draft documents be provided to the dischargers and in turn
to their laboratories, as needed.  However, the review revealed that the documents had either not been
provided by the States and Regions  or were not followed.
       In general, EAD's review of the claims submitted by 11 dischargers revealed the following:
             In nearly all instances where data were submitted, the dischargers and/or their con-
              tract laboratories were using incorrect  analytical methods or did not follow the proce-
              dures required in  40 CFR Part 136.

Chapter 5: Case Histories
Compliance Monitoring Guidance
              In other instances, the dischargers and/or their contract laboratories did not submit
              data necessary to document that the methods were being followed.

              Finally, the dischargers and/or their contract laboratories did not submit documen-
              tation regarding the nature of interferences and the attempts (if any) to resolve these
Case  Histories
Case #1:      This discharger used a contract laboratory for its analytical work.  Informa-
               tion submitted by the laboratory revealed inconsistencies with the stated
               analytical methods.
        The discharger allowed the laboratory to either
               (1) Use alternative methods to the 40 CFR Part 136 methods, or
               (2) Modify Methods 624 and 625.
        Alternative methods  are allowed under 40 CFR Part 136.4 and 136.5 provided that the facility
submits the alternative methods to EPA's Environmental Monitoring and Support Laboratory in
Cincinnati, Ohio, (EMSL-Ci) for approval. Otherwise, alternative methods are not allowed.  BAD
found no reference to alternate methods approved by EMSL-Ci.
        If Methods 624 and  625 were  modified under the spirit of the 40 CFR Part 136 rule, these
modifications were not documented and equivalence was not demonstrated.  Modifications that the
laboratory made to Methods 624 and 625 included:
              Combining acid and base/neutral fractions,
              Using a fused-silica capillary column for the analysis of acid and base/neutral frac-
              Using alternative internal standards,
              Using alternative surrogates,
              Using higher detection limits,
              Using fewer matrix spike compounds, and
              Using matrix spike amounts inconsistent with regulatory compliance, background, or
               method-specified levels.
        The preamble to the 40 CFR Part 136 methods  (49 FR 43234, October 26 1984) states that a
 method is considered to be equivalent if its performance has been demonstrated to meet or exceed the
 specifications hi the original method.  None of the submitted data provided any evidence supporting
 method equivalence.
        EPA recognizes that the use of multiple internal standards and a fused-silica capillary column
 for the base/neutral/acid fraction represent improvements; however, EPA does not accept that com-
 bining fractions, higher detection limits, alternative matrix spike compounds, and matrix spike
 amounts inconsistent with background or regulatory compliance levels represents improvement.  On
 the contrary, these changes  degrade method performance  and are therefore in violation of both the
 spirit and letter of the flexibility permitted in the 600- and 1600-series 40 CFR Part 136 organic

Compliance Monitoring Guidance
Chapter 5: Case Histories
       Method 625 requires the analysis of separate acid and base/neutral fractions (40 CFR Part
136, Appendix A:  Method 625, Sections  10 arid 12 and Tables 4 and 5).  Because combining these
fractions can compound matrix interference problems, the acid  and base/neutral fractions should not
have been combined for these analyses.
       The matrix spike compounds and spiking levels used by the laboratory appeared to have been
from Office of Solid Waste (OSW) SW-846 methods or from Superfund Contract Laboratory Program
(CLP) methods.  The 600- and 1600-series wastewater methods require the matrix spike compounds
to be the compounds regulated in the discharge (e.g., 40 CFR Part 136, Appendix A:  Method 624,
Section 8.3) and require that the spike  levels be at
       (1)    The regulatory compliance level,
       (2)    1-5 times the background level of the analyte in the sample, or
       (3)    The level specified in the method (e.g., Method 624, Section 8.3.1).

The compounds spiked were not those  regulated and the spikes  were not at the levels required.
       The matrix spike was performed on a diluted sample. Had the matrix spike been performed
as specified in Method 624 or 625 (e.g., Method 624, Section 8.4.3), the spike would likely have
failed the specifications in the method and the associated sample result could not have been reported
for regulatory  compliance purposes.  This should have triggered cleanup procedures, the use of
alternative methods, or modification of Method 624 or 625 to improve method performance, as
detailed in the draft "Guidance for Analysts."
       The QC specifications for matrix spike recovery used by the laboratory were not the specifica-
tions given in Methods 624 and 625. The specifications in the  wastewater methods (40 CFR Part
136, Appendix A:  Method 624, Table 5;  and Method 625,  Table 6) must be used for compliance
monitoring.  While tighter specifications from a documented source may be acceptable if met, use of
wider limits without documentation would never be acceptable.
       The detection limits reported for semivolatiles were, for the most part, twice the minimum
levels given in Method 1625 and were  approximately 10-20 times the method detection limits (MDLs)
given in Method 625.   No explanation  for the increased detection limits was given, nor could the
limits be derived from the data provided.
       The laboratory made no attempt to clean up the samples using pH change, gel permeation
chromatography, or the other techniques in the 600- and 1600-series methods or the draft  "Guidance
for Analysts."

Case #2:     Information provided with data submitted  by this discharger was insufficient
              for a detailed review, (as outlined in the "Checklist of Laboratory Data").
       Despite the general lack of data, it appeared the discharger submitted samples to a contract
laboratory for  analyses by a GC/MS method which failed to produce useful results.  The discharger
and/or the laboratory attributed the problems to large concentrations of acetone in the discharge,
though this problem could not be confirmed from the information provided.  The analytical contractor
proposed to the discharger that Methods 601 and 602 be used for the volatiles analysis in  an attempt
to overcome the  interference problems. Because these methods are both more  sensitive and more
selective than a GC/MS method, the analytes regulated should be measurable in the presence of a

Chapter 5: Case Histories
Compliance Monitoring Guidance
large concentration of acetone. The discharger ignored the laboratory's proposal and submitted a
claim of matrix interferences. EPA believes that the approach proposed by the laboratory is workable
and appropriate, and should have been attempted.  If Methods 601 and 602 were used (as with any
other methods used), the analytical laboratory must adhere to all method specifications.

Case #3:      This discharger used several contract laboratories for analyses.  The "re-
               ports" from these laboratories consisted of summary reporting forms show-
               ing detection limits  that were 10-50 times greater than the MDLs in Meth-
               ods 624 and 625.
       There were no QC results, no details of how the analyses were performed, and no documen-
tation of interference problems or steps taken to overcome interference problems, and therefore no
proof that an interference existed. The laboratory may have chosen to dilute samples for conven-
ience.  The discharger and its laboratory must  provide the data listed in the "Checklist of Laboratory
Data" and attempt to solve purported  interference problems using the techniques discussed in the
"Guidance for Analysts."

Case #4:      This discharger submitted a report from  one contract laboratory that con-
               tained insufficient information  for evaluation; and two letters  from a second
               contract laboratory  describing  a problem with 4,6-dinitro-o-cresol.
       The report provided by the first laboratory indicated no results for spikes of the OCPSF-
regulated analytes into samples, no details of how the analyses were performed, what interference
problems were encountered, or what steps were taken to overcome interference problems. In ad-
dition, it appeared that the contract laboratory  combined acid and base/neutral extracts, thus exacer-
bating interference effects.
       The letters from the second laboratory describing the problem with 4,6-dinitro-o-cresol asked
for suggestions  on how to determine this compound in the presence of interferences.  The "Guidance
for Analysts" provides general suggestions for overcoming matrix interference problems and specific
suggestions for  determination of phenol.  The specific  suggestions for determination of phenol can be
applied to 4,6-dinitro-o-cresol.
       Other reports by the contract  laboratory showed high detection limits for the substituted
phenols because of a huge quantity of phenol hi the  sample. One solution to this analytical problem is
for the facility to reduce the level of phenol hi the wastewater.  The analytical laboratory should have
used the procedures for determination of phenol detailed in the "Guidance for Analysts."

Case #5:      This discharger submitted letters and reports from  several contract  labora-
               tories.  One report contained only  some of the data required by the  "Chec-
               klist of Laboratory Data."
       Data items that were present and are required for a thorough review were instrument tunes,
run chronologies, chromatograms, calibration data, calibration verification data, results for blanks,
quantitation reports for samples, and matrix spike data run against the QC limits for Methods 624 and
625. The initial precision and recovery (IPR)  data that demonstrate method equivalence were mis-

Compliance Monitoring Guidance
Chapter 5:
       The semivolatile matrix spike data were inconsistent.  The results of the unspiked samples
indicated that some of the acids and base/neutrals were not detected, yet the results for the spiked
samples showed large concentrations of some of these analytes that were not spiked into the samples.
       The volatiles matrix spike had been diluted by a factor of 200 and spiked after dilution.
Diluting and spiking will not show matrix interferences, and thus these data are of no value in
evaluating the undiluted sample results.

Cases #6-#11:      These facilities  submitted summary reports from their laboratories.
       None of the materials contained the information required by the "Checklist of Laboratory
Data," and none contained explanations of the nature of the interferences found or descriptions of
attempts to overcome these interferences.  These facilities should follow the guidance provided by
EPA and should report all data required by the "Checklist of Laboratory Data" and the "Guidance for
Permit Writers."


                                                                             Chapter 6
                                                             Guidance on  Contracting
                                                                For Analytical Services
       Most businesses and government organizations have procedures and policies governing the
purchase of services and supplies. They range from simply assigning responsibility to one individual
("Joe handles all that...") to the myriad of complex procedures set forth in the Federal Acquisition
Regulations (FAR). Once established, these various procedures and policies may be applied relatively
easily to purchases of office supplies, computers, and janitorial services. However, most organi-
zations experience problems when they attempt to apply these procedures to the purchase of analytical
       At the heart of these problems is the difficulty in defining the services that are required.  The
purpose of this chapter is to provide a basic framework with which to define the technical and con-
tractual requirements associated with purchasing analytical services related to compliance monitoring
under the National Pollutant Discharge Elimination System (NPDES).  The procedures outlined here
are presented as guidance and may need to be modified to  meet the specific policies of an organi-
zation. The level of detail presented is not sufficient to meet all of the requirements of the FAR, but
is a subset of the procedures used by several EPA offices and their contractors.  The procedures may
represent some degree of "overkill" for private organizations; however, it is simpler to delete the
unneeded detail in those instances than to add it when  it is  required. The procedures are designed for
procuring analytical services from commercial laboratories, but may also be applied to requests for
services from in-house laboratories.

Requirements Analysis
       Defining what services are required is often the most difficult step. The commercial environ-
mental laboratory business has grown to be a multi-million-dollar-per-year enterprise serving the
diverse needs of clients regulated under a variety of federal and state environmental statutes.  Many
laboratories have recognized the importance of customer service and employ staff who are trained to
assist clients in defining the requirements.  Other laboratories, large and small, rely solely on the
client to define the specific requirements. Still another group of laboratories, albeit a small group,
perform analyses with little regard to the client's actual needs. One of the problems that arises when
the client's requirements are poorly defined is the use  of inappropriate methods.  As noted in Chap-
ter 1, NPDES compliance monitoring requires that the 304(h) methods be used.  It is not the labora-
tory's place to decide that a method from another source, even another EPA source, is "close
       The "five W's" of journalism ("who, what, when,  where, and why," with "how" thrown in
for good measure) are a first step in defining the requirements.  "Who" is the name of the client,
including a set of specific contact points.  The laboratory needs  to know the name of the person who
will be taking and shipping the sample, in the event that there are shipping delays, broken samples,

Chapter 6:  Contracting
Compliance'Monitoring Guidance
etc.  The laboratory needs the name of a technical contact, if any, in the event that there are analy-
tical questions that need to be resolved.  The laboratory also needs to know the name of the admini-
strative contact who will handle issues of billing, payment, etc.
       "What" is a description of the samples to be analyzed, including:

              Number of samples,
              Matrices (e.g., wastewater, sludge, solids, soils, etc.), and
              Analyses required (volatile organics, pesticides, etc.).               

"What" may also include information on the required methodology, the reporting format, and the
quality assurance/quality control (QA/QC) requirements.  It may also include a specific description of
the "product" to be delivered to the client. EPA recommends (Chapter 4) that the client receive a
copy of all data, raw and summary, associated with the analyses.
       "When" specifies the approximate date that the samples will be shipped to the laboratory,
including the means of shipment (hand-delivered, picked up by the laboratory, overnight air freight,
etc.), and the date when the  results are required by the client. It should also specify the date by
which the results are required. The "turnaround time" is the length of time, usually in calendar days,
from the receipt of the sample at the laboratory until the results are to be received by the purchaser.
The turnaround tune is often a function of a reporting deadline under a permit. One can often save
cost by giving the laboratory as much tune as possible to provide the data.  Sampling early in the
month may mean that one has more tune before the data must be reported to the permitting agency.
       Obviously, "where"  includes the name of the laboratory, but it is important to include the
street address of the laboratory to which the samples will  be shipped and the name of the person
assigned to receive the samples.  It is also  important to include the name and address of the labora-
tory's administrative personnel handling billing and payment issues, as these may be different from
the address where samples are shipped.
       "Why" is often overlooked by people who assume that everyone understands the purpose of
the analysis.  Simply stating that "the analysis of X wastewater samples for NPDES compliance
monitoring is required" can give a laboratory a wealth of information. Among other things, it should
inform the laboratory that a 304(h) method is to be used; however, just to be certain, the method
required is also specified elsewhere (see "how" below). In contrast, a statement about "ground-water
monitoring" ought to lead the laboratory to inquire as to the purpose of the analysis, and hence what
methods might  be required, as 304(h) methods may not be appropriate.  The type of analyses required
can also be included, further clarifying the requirements.
       The last requirement to be explicitly stated  is "how."  Although information about the
analysis is included in "what" and "why," it helps to be specific, stating the method that is required
or requested. It is also important to specify the quality assurance and quality control operations that
will be performed in association with the sample analyses. While the EPA 600- and  1600-series
methods specify the level of QA/QC to be performed, there are some methods from other sources
(SW-846, ASTM, AOAC, etc.) that have been approved under Section 304(h) for some analytes, and
these methods may not be as explicit regarding the  QA/QC requirements. The laboratory also needs
to know how the data are to be reported and how many copies of the report are required.

Compliance Monitoring Guidance
Chapter 6: Contracting
Identifying Laboratories and Soliciting Bids
       Identifying qualified laboratories can be a time-consuming process. While many laboratories
advertise in the Yellow Pages and in various directories of professional services, those advertisements
may not tell you much about the laboratory's abilities to fulfill your specific analytical requirements.
However, any list of laboratories is better than none. In addition, state and EPA Regional personnel
may be able to give you a list of laboratories in your area or nationwide, depending on the type of
analyses required. Such lists are not an endorsement of these laboratories, but are provided as a
starting point.
       If your procedures require that you obtain competitive bids for laboratory services, you will
Usually have to identify a minimum of three laboratories from which to solicit bids. If you are not
required to obtain competitive bids, it may still be useful to occasionally compare prices from compe-
ting laboratories.
       Determining that a laboratory is qualified to perform the analyses is also a somewhat daunting
task. You can always take the laboratory director's word for their capabilities.  However, you then
have to evaluate the consequences of making a error in judgment.  While EPA is currently exploring
the idea of a national laboratory  accreditation program, it is unlikely that such a program will be in
place for several years. In the meantime, you can begin to identify qualified laboratories by sending
them a list of your requirements, identified above.  Ask them to provide information regarding their
qualifications to perform such work (SOQ).  Obviously, this needs to be done well in advance of your
need for actual analytical services. The laboratory should be willing to discuss your specific needs
with you, and demonstrate how they  will meet those needs. While not normally required for NPDES
compliance monitoring, it is not  unheard of to perform an on-site inspection of a laboratory prior to
using their services.  It may also be worthwhile in some instances to send performance evaluation
samples (samples of known composition) to a laboratory prior to utilizing them for routine analytical
work. Performance evaluation samples for various organic and inorganic analytes are commercially
available from several vendors.  These vendors may also prepare custom samples that focus on the
regulated pollutants at a specific  facility.
       Once you have identified a group of laboratories, you may solicit bids by simply sending
them a request for a bid, including the detailed requirements identified above.  One possible format
for such solicitations is included  with this report as an attachment. This is a generic version of a
format that several EPA contractors have used for some time.
       The NPDES compliance  monitoring requirements for a given facility may only require the
analysis of a small number of samples monthly or quarterly.  While those analyses are very important
to you (the discharger), they may not represent a significant source of revenue for a given laboratory.
At some level, you are paying for all the quality control analyses associated with your small number
of samples. As a result, you may pay higher prices per sample.  One way to address the cost issue is
to pursue a longer-term contracting arrangement.  Determine how many analyses of what types you ,,
will need for the next year, and ask laboratories to .bid on the entire package. To do this, you must
be able to approximate the schedule on which these analyses are needed, but that is often driven  by
permit requirements.  The advantages to you are (1) a lower price and (2) less time spent arranging

Chapter 6:  Contracting
Compliance Monitoring Guidance
for bids. The advantages to the laboratory are (1) knowing that the work is coming and (2) spending
less time getting business.

Writing  a Contract
        Before writing a contract for any kind of services, consult with the appropriate legal staff at
your facility or firm.  They will obviously know the ins and outs of contract law in your state. A
well-written contract will include the "five W's" outlined above.  It will also address your right to
review the data as needed,  the timeliness of payment to the laboratory, and your ultimate  right to
determine that the work does not meet the requirements established in the contract.
         The required data turnaround and analytical holding time must be stated clearly  in the
contract.  If analytical holding times are applicable, they are generally stated in the analytical method.
However, delays in sampling and sample shipment may necessitate specification of a "contract"
holding time that is based on the analytical holding time minus any time required for sample ship-
ment.  Unless you can guarantee that the sample will be delivered as soon as the laboratory opens in
the morning, it is typical to specify that the day that the sample is received at the laboratory is "day
zero," and the counting of "days" begins with the following day as "day 1."
        In addition to stating the time that the laboratory has to generate and deliver the data,  it may
be useful to assign some specific consequences to the possibility of late delivery. One approach is to
assess a penalty of some percentage of the analytical price per day of lateness.  In the  past, EPA has
used values of 1-2% per day after the due date that the data were delivered.
        Obviously, such penalties for lateness cannot be due to changes in the requirements made
after the samples were sent, or the fact that the methods requested were not applicable to the samples.
Many of the remedies to matrix problems discussed in Chapter 2 cannot be expected to be carried out
in the original turnaround time assigned to the sample.  However,  once you have established that your
samples can routinely be analyzed by the requested methods, lateness becomes an issue of laboratory
management practices, not sample matrix.
        From time to time, almost every laboratory will produce data that are of little  use for the
intended purpose (compliance monitoring hi this instance).  While well-run laboratories will contact
you as soon as they identify the problem and work with you to make the best of a bad situation, you
may still find yourself with no useful data and a deadline approaching.
        A contract should stipulate  that the laboratory will reanalyze samples at no cost to the client if
the problems are due to laboratory  error.  It should also state that the client has the right to inspect
the results, and if they do not meet the requirements in the contract, the client has the right to reject
the data, returning them to the laboratory without payment.  Rejection of data should be based on
sound technical review of the results.  It also obligates the client to make no use of those results
without making some payment to the laboratory.
        The contract should discuss in what instances dilutions of samples and reanalyses are  con-
sidered billable by the purchaser.  Again, a laboratory should be prepared to do the job right the first
time and not bill for reanalyses required due to their errors.  In contrast, some samples may need to
be diluted and reanalyzed in order to bring the results  within the demonstrated calibration range of the
instrumentation. When this occurs, the laboratory ought to be paid for this effort. Such reanalyses

Compliance Monitoring Guidance
Chapter 6:  Contracting
can be figured into the original price, inflating the per-sample price for all samples to account for the
need to reanalyze some samples, or it can be broken out as a separate cost. Similarly, for analyses
involving an extraction or digestion as well as an analysis, it may be useful to specify the price for
the extraction step and the analysis separately,  as a reanalysis may  not require an additional extrac-
        The contract is not a one-sided agreement, and as such, it must give specific rights and
recourse to the laboratory as well.  You may be asked to negotiate specific contract issues with the
laboratory beforehand.  The time involved in this process will obviously vary, and one of the benefits
of contracting over longer time periods than the immediate need for one analysis is that these negotia-
tions need only take place once for a large number of samples.
        Combined with a careful analysis of the requirements, a well-written contract can minimize or
eliminate many common problems in procuring analytical services. It should enable the client to
obtain technically sound, legally defensible, and timely analytical data to meet a variety of compliance
monitoring needs.