PROTOCOL FOR APPROVAL OF ALTERNATE TEST PROCEDURES
FOR INORGANIC AND ORGANIC ANALYTES IN NATIONAL POLLUTANT
DISCHARGE ELIMINATION SYSTEM MONITORING
Revision 1.3
January, 1996
U.S. Environmental Protection Agency
Office of Research and Development
National Exposure Research Laboratory
Cincinnati, Ohio 45268
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PROTOCOL FOR APPROVAL OF ALTERNATE TEST PROCEDURES FOR
INORGANIC AND ORGANIC ANALYTES IN NATIONAL POLLUTANT
DISCHARGE ELIMINATION"' SYSTEM MONITORING
INTRODUCTION
An alternate test procedure (ATP) is one that differs from a
method previously approved by the.U. S. Environmental Protection
Agency (USEPA) for determining the constituent of interest in
National Pollutant Discharge Elimination System (NPDES) monitoring.
Any person may apply for approval of the use of an alternate test
procedure for a specific constituent in NPDES monitoring.
Before submitting an ATP application, however, the applicant
is responsible for performing an in-depth comparison of the
description of the proposed method with the description of the
appropriate approved NPDES method(s), listed in Tables IB, 1C, or
ID of section 136 of Title 40 of the Code of Federal Regulations
(CFR) . In this comparison each of the topics, outlined in the
Method Description Requirements (pp. 2-4), must be considered in
detail. If this comparison reveals that there are absolutely no
differences in the technical details of the proposed and approved
methods, the methods are considered identical and an ATP
application is not required. If the proposed method differs
slightly in any of the technical details, the applicant may choose
to: (1) modify the method so that it is identical to one of the
previously approved methods, (2) submit a simple 2-column
comparison (see the text on p. 4 in the Method Description
Requirements) for NERL-Cincinnati determination of the
comparability of the proposed method or the need for an ATP
application, or (3) submit an application for approval of an ATP.
Every ATP application shall be made by letter in triplicate.
An application for nationwide (NW) approval of a proposed ATP
should be forwarded to the Acting Director, Ecological Exposure
Research Division - Cincinnati (NERL-Cincinnati), U.S.
Environmental Protection Agency, Cincinnati, Ohio 45268. An
application for approval of the limited-use (LU) of an ATP by a
regional EPA laboratory should be forwarded directly to the
appropriate Regional Administrator. An application for approval of
the limited-use of an ATP by a State or commercial laboratory or an
individual discharger or permittee shall be forwarded directly to
the Director of the State Agency issuing NPDES permits in that
State if that State has primacy (i.e., the state permit program is
USEPA-approved) . If the State does not have primacy, then the
application by a State or commercial laboratory or individual
discharger or permittee
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should be forwarded directly to the appropriate USEPA Regional
Administrator. The State Agency Director and USEPA Regional
Administrator will forward applications as required.
APPLICATION REQUIREMENTS
The general requirements for an ATP application include the
name and address of the applicant and/or authorized representative;
if applicable/ the applicant's NPDES permit number; the pollutant
or constituent for which the ATP is proposed; the type of approval
desired (NW or LU); justification for the proposed ATP; the full
title of the method, company identification number and date of
preparation of the proposed method; a complete description of the
proposed method and of the approved method if used in a comparison;
and the comparability data. All information provided to the
Government is subject to the requirements of the Freedom of
Information Act. Any proprietary information' in the proposed
method should be marked as "Confidential". USEPA staff will handle
all proprietary information according to the regulations in
subparts A and B of Part 2 of Title 40 CFR.
Initially an applicant should forward the above information,
except the comparability data, to NERL-Cincinnati. Upon receipt of
the application, the NERL-Cincinnati ATP staff will assign the
application an identification number, which should be used in all
future communications. The NERL-Cincinnati ATP staff will perform
an initial evaluation of the submitted information and advise the
applicant of the specific comparability data requirements, if
applicable.
Method Description Requirements
Each method description must include the following topics,
listed in the recently formulated Environmental Monitoring
Management Council (EMMC) method format:
1.0 Scope and Application
Include analyte identification; CAS number; sample type;
method sensitivity, expressed as mass; and, concentration
range.
The concentration range of the proposed method should be equal
to or greater than that of the approved method. If the range
is smaller than that of the approved method (particularly, if
the detection limit is higher), EMSL may advise that the
method is inapplicable or the method may require a declaration
of method limitations.
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2.0 Summary of the Method
Describe the scientific basis, e.g., chemical principles,
reactions, kinetics.
3.0 Definitions
4.0 Interferences
As a separate document, include data observed by appliccr.t
(during method development) using typical wastewater samples
containing a specific quantity of an interfering substance.
5.0 Safety
Refer to good laboratory practice, appropriate material safety
data sheets, and use of hood, goggles, and/or protective
clothing. Emphasize any special procedure.
6.0 Equipment and Supplies
As a separate document, include any applicable manuals.
7.0 Reagents and Standards
Describe reagent formulations and shelf life of packaged
materials.
8.0 Sample Collection, Preservation, Shipment, and Storage
The guidance in Table II of Part 136.3 of Title 40 of CFR
takes precedence over the information published in the
approved methods'.
9.0 Quality Control
Indicate need for a formal laboratory quality control program;
initial and periodic demonstration of performance by analyzing
reagent blanks, check standards, and/or fortified samples; and
maintenance of records, QC charts, etc. The periodic checking
of performance should preferably occur at a minimum frequency
of 10% of the total samples.
10.0 Calibration and Standardization
This section should include the calibration steps that are not
performed daily. Include the daily calibration step(s) in
the procedural section.
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11.0 Procedure
Include in the method write 'up the.procedural steps and the
daily calibration steps. As a separate document include a
typical calibration graph or curve.
12.0 Data Analysis and Calculations
13.0 Method Performance
Indicate the percent recovery, precision, and bias of the
method for typical wastewater samples, fortified with known
amount(s) of the analyte. Include the method detection limits
(MDL), derived as outlined in Appendix B of section 136 of
Title 40 of CFR, and expressed in weight/ volume. The
calculated MDL should be confirmed by analyzing a sample at
the calculated MDL concentration. Note that the MDL should be
equal to or smaller than that of the approved method. If the
MDL is higher, EMSL may advise that the method is inapplicable
or the method may require a declaration of the method's
limited range of performance.
14.0 Pollution Prevention
Cite good laboratory practices for pollution prevention.
15.0 Waste Management
Cite how waste and samples are to be disposed.
16.0 References
Include reference to documents and publications.
17.0 Tables, Diagrams, Flowcharts, and Validation-Data
Any proprietary information in the proposed method should be
marked "Confidential". USEPA staff will handle all proprietary
information according to the regulations in subparts A and B of
Part 2 of Title 40 of CFR.
If the proposed method is very similar to an approved and
promulgated method, the applicant should simply prepare a two-
column comparison of the approved and proposed methods. (The
combined width of the two columns shall not exceed 17 inches.)
This document should include the title and identification number of
each method, the date of the proposed method and all the topics
listed in the previous outline. The applicant should highlight any
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differences in the proposed method. If the method is an automation
of a previously approved manual method, any differences in kinetics
and interferences should be presented and a comparison of the final
ratios of the concentrations of the reactants in the proposed and
approved methods should be included. This information should then
be forwarded to NERL-Cincinnatii for review and recommendation
regarding the comparability of the proposed method or need for an
ATP application.
Comparability Data Requirements
A method comparability study will be required for each new or
significantly revised method submitted for nationwide approval.
Guidance for the comparability study is provided in the following
text. Applicants are encouraged to have a brief consultation with
the EMSL ATP staff regarding specific comparability study plans
which may include the number of analyses, concentration levels,
quality control activities, performance evaluation samples, etc.
If a major area differs, such as the concentration range of the
proposed method differs from that of the approved method, the
applicant must consult with the NERL-Cincinnati ATP staff to
determine the appropriate modification of the comparability study
design.
The comparability data shall include observations of effluent
samples, quality control samples in reagent water and performance
evaluation samples in reagent water. Initially, each collected
effluent will be analyzed once by the approved method to determine
the concentration of the constituent of interest and the need for
sample dilution and/or fortifying to achieve a baseline
concentration equal to 5 times the method detection limit as
detailed in the Subsample Preparation Requirements (pp. 7-8).
After appropriate preparation, the subsamples of each effluent are
to be analyzed by both the approved and proposed methods.
The . quality control samples (QC) and the performance
evaluation samples (PE) are to be prepared in reagent water and
used to determine if the laboratory is in control. PE samples
containing known analytes, but of concentrations unknown to the
analyst, will be provided by EMSL along with instructions for use.
The analyst is responsible for preparing the final QC and PE sample
solutions for analyses. The QC and PE solutions must be spaced
every tenth sample among the effluent samples which are to be
analyzed by both methods.
As general guidance, the minimum number of analyses required
are summarized in the following table. However, depending on the
particulars of the method under review, the number of analyses may
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change. We strongly suggest consultation with the EMSL ATP staff
prior to analyses.
Type of Initial Lowest
Approval Applicant Screening Cone.* Fortified QC/PE Total
^ »^ ^^ ^^ ^^ ^ ^^^^^^^^^^^^^^^^ ^ ^ ^OM^^^^^^^^^^^^^^^B^^^^ ^
Nationwide Any 10 60 120-!-180 18-24 208-274
Limited Use USEPA 5 30 60-90 9-12 104-137
Regional,
State or
commercial
Limited Use Individual 5 20 40 6 71
* It is highly desirable to use effluents which have a low level (5
x MDL) of the analyte(s) of interest. When this is not possible,
the effluent must be diluted to a low level so that the fortified
concentration is detectable and quantifible.
Effluent Sampling Requirements
For each constituent of interest, the applicant must collect
a specified number of samples from a specified number of companies
from a specified number of industry types, the latter identified by
their individual 1987 standard Industrial Classification (SIC)
codes. The general requirements are summarized in the table below
Consultation with the EMSL ATP .staff may result in changes to the
general requirements based upon specific conditions of the method
under review.
No. effluent
Approval No. SIC No. companies samples per Total no.
type Applicant codes per SIC code company of samples
NW Any 52 1 10
LU USEPA 51 15
regional,
state, or
commercial
lab
LU Individual 1 1 55
discharger
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The NERL-Cincinnati ATP staff will provide the appropriate
constituent or analyte code(s) 'and 1987 SIC Codes and code
descriptions to an applicant for either of the first two types of
approval (listed above). If the applicant has difficulty locating
appropriate sample sources (for these two types of applications),
he may obtain (for a fee) a list of major companies, their
addresses/ contact persons, telephone numbers, and recent
constituent measurements by directing a Freedom of Information
(FOI) request to Jeralene B. Green, FOI Officer, MS-A101, 401 M
Street, S.W., Washington, DC 20460, telephone: 202-260-4048. The
requestor must designate the Permit Compliance System as the source
of the information and specify the constituent or analyte code and
name, the SIC codes, . and geographical locations of interest
(nationwide, regional, and/or state). Note that the individual
discharger LU applicant must collect five samples of his own
effluent, representing only one SIC code. Occasionally, an
individual discharger may have two or more different effluents. In
this case he should consult with the NERL-Cincinnati ATP staff
concerning the sampling requirements.
An applicant is required to diligently select a source and/or
time of collection that will afford a constituent concentration as
close as possible to 5 x MDL. (if the MDL is unpublished,
determine as directed in Section 13, Method Performance on p. 4.)
This selection will enable the preparation of the required
subsamples by either dilution or fortifying with a minimum of
alteration of sample matrix.
All samples should be collected using the containers,
preservation techniques, and holding times outlined in Table II of
section 136 of the aforementioned CFR.
Subsample Preparation Requirements
The bias, precision and percent recovery of the proposed
method will be compared to the bias, precision and percent recovery
of the approved method. Several levels of concentrations covering
the performance range of the proposed method will be used in the
study. Ideally, the range of concentration for the proposed method
will be the same as the approved method. This issue must be
addressed with the EMSL ATP staff prior to analyses.
The study design initially requires a single analysis of each
of the collected samples by the approved method to determine the
concentration of the constituents of interest. If the initial
concentration of the constituents in any collected sample differ
from the 5 x MDL level, the sample must then be either carefully
diluted or fortified to achieve the 5 x MDL level. Dilutions must
be done using reagent water, as defined in the approved method.
Sample fortifying must be accor.;.lished using a substance whose
character reflects the nature of the analyte in the effluents
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and/or the calibration standards. For example, in an ATP for
mercury the fortifying substance must consist of a mixture of
inorganic and organic mercury compounds. Sample adjustment to the
baseline or 5 x MDL concentration must be performed before
splitting the sample into subsamples otherwise, the analytical
error of each analysis may also include the error of any individual
adjustment of the subsamples to the 5 x MDL level. Record and
report all sample dilutions and/or fortifying required to adjust
each sample concentration to the 5 x MDL level.
The fortifying of each subsample must also be achieved before
aliquoting for analysis. Otherwise, the analytical error will
include individual fortifying errors and the analytical data may be
inappropriate. Record and report the amount of the substance added
to each fortified subsample and the theoretical total concentration
in each subsample. The latter is calculated for each subsample by
adding the mean of the replicate analyses of the subsample by the
approved method to the amount of substance added to that subsample.
The evaluation of the comparability of the proposed method is
dependent upon subsamples with very similiar concentrations.
Laboratory Requirements
It is highly desirable to have one laboratory analyze all the
samples required in the study design. This is to eliminate the
effects of multiple laboratories on the comparision of data between
methods. Analyses by an additional laboratory should be included as
a check but these data are in addition to the required ATP
comparative analyses by the primary laboratory. This option should'
be discussed with the ATP staff prior to generating data. In
nationwide applications, the laboratory should be independent, that
is, without a vested interest in the company. NERL-Cincinnati will
judge on the appropriateness of the suggested laboratory.
Approved Method Selection Requirements
Since the approval of an ATP depends upon the comparability of
the proposed method to that of an approved method, the applicant's
analyses by the approved method must also be examined to determine
their acceptability as a basis in the comparison. This
acceptability will be determined by comparing the applicant's
analyses of QC and PE Samples by both the approved method and the
proposed method.
The criteria used in the evaluation will be derived from
available regulations, text of the approved method, and/or various
interlaboratory validation and/or performance evaluation studies.
USEPA may, consequently, limit the applicant's choice of an
approved method to insure that' the approved method used in a
comparability study is one which has been evaluated with sufficient
frequency in the interlaboratory studies to afford an appropriate
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data base with which to determine the acceptability of the
applicant's analyses by the approved method.
Effluent Subsample Analysis Requirements
Applicants for nationwide approval and individual USEPA
Regional, State/ or. commercial laboratory applicants for limited-
use approval of an ATP must perform six analyses of each subsample,
three by the approved method and three by the proposed method.
Individual dischargers applying for limited-use approval must
perform four analyses of each subsample/ two by the approved method
and two by the proposed method. The effluent sample, effluent
subsample/ and analysis requirements (without screening analyses)
are summarized in the following table:
No. of
replicate
No. of analyses
sub- Total per sub-
samples No. sub- sample Total
No. of per samples per each No.
collected collected for of two of
Appvl. Applicant samples sample analysis methods analyses
NW
LU
Any
USEPA
10
5
3-4
3-4
30-40
15-20
3
3
180-240
90-120
regional,
State, or
commercial
lab
LU Individual 53 15 2 60
discharger
The aforementioned quality control analyses must be performed
at a 10% frequency among the analyses of the effluent samples and
subsamples (See Comparability Data Requirements, pp.5-6).
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Data Reporting Requirements
Initial single observations of the collected samples by the
approved method, dilutions and/or fortifying of each collected
sample/ the quantity of substance added to each subsample, and the
total theoretical concentration of each subsample, the replicate
observations of all subsamples by both methods, and quality control
observations must be forwarded to USEPA.
A suggested format for reporting the observations of each set
of subsamples is attached. The quality assurance observations
associated with each set of subsample observations should also be
tabulated and identified. An evaluation of the ATP application can
be accomplished more quickly by the NERL-Cincinnati ATP staff if
the information is also forwarded on one or more floppy discs
compatible with an IBM-PC computer. The text on the disc should be
presented in the latest version of WordPerfect (currently, 6.0) and
the data may be presented in WordPerfect or in ASCII.
DATA REVIEW AND METHOD RECOMMENDATION
Upon receipt of an the applicant's data sets, NERL-Cincinnati
staff will initiate its technical and statistical reviews.
Appropriate criteria, derived either from published regulations or
from interlaboratory studies, will be- used to' determine the
acceptability of the approved method data as a basis in the
evaluation of the analyses by the proposed method. If this
evaluation is favorable, the evaluation of the comparability of the
proposed method will follow.
Since the sampling and analytical requirements for each ATP
application are based on a factorial experimental design with three
factors, namely, method, sample matrix, and constituent
concentration, each comparability review will be conducted over the
range of. these three factors. Descriptive statistics, such as the
mean, standard deviation, coefficient of variation (relative
standard deviation), and percent recovery of each set of replicates
will be calculated. The precision of the proposed method will be
compared with that of the approved method by means of a
nonparametric statistical procedure attributable to Scheffe. An
analysis of variance (ANOVA) will be used to compare the accuracy
of the proposed method with that of the approved method.
Upon completion of the technical and statistical reviews,
NERL-Cincinnati will prepare its recommendation for
approval/disapproval, notify the applicant of its recommendation,
and forward the recommendation to the appropriate approval
authority. An ATP recommended for nationwide approval will be
forwarded to the 304(h) Committee, which has been delegated the
responsibility of proposing the s-.TP in the Federal Register.
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After a three-month public comment period, this committee will
review any submitted comments and prepare the final nationwide
approval/disapproval decision and notice in the Federal Register.
A recommendation for approval/disapproval of a limited-use ATP will
be forwarded initially to the appropriate EPA Regional
Administrator and, subsequently, to the appropriate State Agency
Director, who are responsible for the final decision and notice to
the applicant.
If you have any questions regarding the requirements,
especially the comparability study design and the subsample
fortifying, please contact the ENERL-CincinnatiCincinnati ATP staff
at 513-569-7307.
REFERENCES
1. Villa, 0. and L. Reed, Co-Chairs, EMMC Methods Integration
Panel. Final Version of Approved EMMC Format (Memorandum to
Members of EMMC Steering Committee, Methods Integration Panel,
and Work Group, Tri-Chairs). U. S. Environmental Protection
Agency, February 14, 1992, pp. 1-2.
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Application No:
(USEPA Assigned)'
NPDES COMPARABILITY STUDY DATA
Source or Discharger Identity:
SIC Code:
Constituent Identity:
Concentration Units (weight/volume):
Initial Sample Constituent Cone. (Before Adjustment)
Initial Sample Adjustment
by Dilution
(specify )
or by Fortifying
(specify weight/volume)
Sub-
samp
1
2
3
4
Theoretica Cone. Approved Method Observations Proposed Method Observation*
Amount
Added*
0
Total^
Cone
Replicate
1
Replicate
2
Replicate
3
Replicate
1
Replicate
2
Replicate
3
* Identify the applicant or source of data ONLY by the USEPA-assigned application number.
+ See pp. 7-8 of the protocol for a discussion of how these concentrations are derived.
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