[Federal Register Volume 78, Number 44 (Wednesday, March 6, 2013)]
[Rules and Regulations]
[Pages 14457-14461]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-05248]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 136
[EPA-HQ-OW-2010-0192; FRL-9787-7]
Guidelines Establishing Test Procedures for the Analysis of
Pollutants Under the Clean Water Act; Analysis and Sampling Procedures;
Notice
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of final decision.
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SUMMARY: EPA discussed, but did not propose, a new method, ASTM D7575,
for oil and grease in the 2010 proposed Methods Update Rule (MUR). Oil
and grease is a method-defined parameter. That is, the nature and
amount of material determined by the method is defined in terms of the
method. EPA subsequently published a Notice of Data Availability (NODA)
on this method that provided new data and requested comment on whether
and how EPA should approve the method in Part 136 as an alternative oil
and grease method. This document provides EPA's final decision on its
reconsideration of this method.
DATES: March 6, 2013.
FOR FURTHER INFORMATION CONTACT: Jan Matuszko, Office of Science and
Technology, Office of Water (4303-T), Environmental Protection Agency,
1200 Pennsylvania Avenue NW.; Washington, DC 20460; telephone number:
202-566-1035; fax number: 202-566-1053; email address:
[email protected].
SUPPLEMENTARY INFORMATION:
I. Background
A. CWA Analytical Methods and Limited Use Alternate Test Procedures
(ATP) Program
EPA establishes test procedures (also referred to as analytical
methods) codified in 40 CFR Part 136 under its authority in section
304(h) of the CWA to promulgate guidelines establishing test procedures
for the analysis of pollutants. EPA's regulations provide that, when
EPA has promulgated a test procedure for analysis of a specific
pollutant in 40 CFR Part 136, an NPDES permittee must use an approved
test procedure for the specific pollutant when measuring the pollutant
for an application submitted to EPA or to a State with an approved
NPDES program and for reports required to be submitted by dischargers
under the NPDES program. See 40 CFR Sec. 136.1(a). This approach
simplifies the permitting process for hundreds of thousands of NPDES
and indirect discharging permittees and permitting authorities. In the
absence of an approved test procedure for a specific pollutant (or when
an approved test procedure does not work in a specific matrix, e.g.,
because of a matrix interference), generally, a permit applicant may
use any suitable method but must provide the permitting authority a
description of the method for evaluation of its suitability. See 40 CFR
122.21(g)(7). However, 40 CFR Part 136 also recognizes that new
technologies and approaches are constantly being developed, including
methods for pollutants for which EPA already has an approved test
procedure. As such, Part 136.5 allows for use of an alternate method
for a specific pollutant or parameter in a regulated CWA matrix that is
different from the approved test procedure (i.e., limited use
approval). Requests for such uses, along with supporting data, are made
to the applicable Regional Alternate Test Procedure (ATP) Coordinator
for consideration and approval.
B. Oil and Grease
Unlike many parameters, oil and grease is not a unique chemical
entity, but is a mixture of chemical species that varies from source to
source. Common substances that may contribute to oil and grease include
petroleum based compounds such as fuels, motor oil, lubricating oil,
soaps, waxes, and hydraulic oil and vegetable based compounds such as
cooking oil and other fats. Oil and grease is defined by the method
used to measure it (i.e., it is a method-defined analyte). The CWA
defines oil and grease as a conventional parameter and hundreds of
thousands of NPDES permits and indirect discharging permits contain oil
and grease numerical limits. Currently, Part 136 lists two analytical
methodologies for the measurement of oil and grease in such discharge
permits. Permittees have been using EPA Method 1664A to measure
compliance with such discharge limits. Method 1664A is a liquid/liquid
extraction (LLE), gravimetric procedure that employs normal hexane (n-
hexane) as the extraction solvent that is applicable for measuring oil
and grease in concentrations from 5 mg/L to 1,000 mg/L. This method
also allows the use of solid-phase extraction (SPE) provided that the
results obtained by SPE are equivalent to the results obtained by LLE.
C. Method-Defined Analytes
The measurement results obtained for a method-defined analyte are
both
[[Page 14458]]
specific to that method and solely dependent on the method used. As a
consequence, the results obtained for a parameter defined by one
particular method are not necessarily directly comparable to results
obtained by another method (i.e., the data derived from method-defined
protocols cannot be reliably verified outside the method itself). EPA
has defined a method-defined analyte in 40 CFR 136.6(a)(5) as ``* * *
an analyte defined solely by the method used to determine the analyte.
Such an analyte may be a physical parameter, a parameter that is not a
specific chemical, or a parameter that may be comprised of a number of
substances. Examples of such analytes include temperature, oil and
grease, total suspended solids, total phenolics, turbidity, chemical
oxygen demand, and biochemical oxygen demand.''
D. EPA's Past Consideration of Alternative Oil and Grease Methods for
Adoption in 40 CFR Part 136
Because oil and grease is a method-defined parameter, EPA has not
considered promulgating multiple methods to measure oil and grease that
are based on different extractants. Moreover, EPA has not considered
multiple oil and grease methods that are based on different
determinative techniques. The only exception to this was EPA's
promulgation of EPA Method 1664A in 1999 to replace EPA Method 413.1
(64 FR 26315), a similar procedure that used Freon[supreg] (1,1,2-
trichloro-1,2,2-trifluoroethane (CFC-113; Freon-113)) as the extraction
solvent. EPA made this exception because Freon[supreg] was banned by an
international treaty (the Montreal Protocol on Substances That Deplete
the Ozone Layer), and until the ban went into effect, EPA allowed
either of these oil and grease methods for CWA compliance. In both
methods, the determinative technique is gravimetry and the only change
was the extraction solvent (n-hexane instead of Freon[supreg]).
When EPA promulgated EPA Method 1664A to replace EPA Method 413.1,
EPA evaluated a variety of possible replacement extracting solvents in
addition to n-hexane. EPA selected n-hexane and promulgated Method
1664A after conducting multi-year, extensive side-by-side studies on a
variety of samples representing a wide range of matrices/discharges
(see ``Preliminary Report of EPA Efforts to Replace Freon for the
Determination of Oil and Grease,'' EPA-821-R-93-011, September 1993,
and ``Report of EPA Efforts to Replace Freon for the Determination of
Oil and Grease and Total Petroleum Hydrocarbons: Phase II,'' EPA-820-R-
95-003, April 1995). In considering which solvent produced results most
comparable to results obtained with Freon[supreg], EPA conducted a Root
Mean Squared Deviation (RMSD) evaluation of the data collected in the
side-by-side studies. None of the alternative solvents produced results
statistically comparable to results produced by Freon[supreg]. However,
EPA concluded at the time that n-hexane was appropriate as an
alternative solvent, based on overall extraction results (96% versus
100% for Freon) and analytical practical considerations (e.g., boiling
point).
To accommodate concerns about possible differences in results, EPA
allowed permitting authorities to establish a conversion factor by
having the discharger perform a side-by-side comparison of Method 1664A
and the Freon[supreg] extraction method and then adjusting the
discharge limits, if necessary, to account for differences in the
permit. EPA further recommended a specific process to follow for the
side-by-side comparison in the guidance document for Method 1664A (see
``Analytical Method Guidance for EPA Method 1664A Implementation and
Use (40 CFR part 136),'' EPA/821-R-00-003, February 2000).
E. Proposed 2010 Methods Update Rule (MUR)
On September 23, 2010, EPA proposed to add new and revised EPA
methods to its Part 136 test procedures (75 FR 58024). Among other
methods, in the September 2010 proposal, EPA described three oil and
grease methods published by ASTM International or the Standard Methods
Committee that require a different extractant and/or a different
measurement (i.e., determinative) technique than the existing Part 136
oil and grease methods. These methods were ASTM D7575, ASTM D7066 and
Standard Methods 5520. Section 12(d) of the National Technology
Transfer and Advancement Act (NTTAA) of 1995 (Pub. L. 104-113; 15
U.S.C. 272 note) directs EPA to use voluntary consensus standards in
its regulatory activities unless to do so would be inconsistent with
applicable law or is otherwise impractical. As such, when requested by
ASTM and Standard Methods to include their methods in 40 CFR Part 136,
EPA may propose to approve a method or explain why it should or should
not do so. The proposal explained the issues surrounding method-defined
parameters, and explained that, consistent with past practices, EPA was
not proposing to include any of the three oil and grease methods in
Part 136, including ASTM D7575.
F. December 2011 Notice of Data Availability (NODA)
In response to the September 2010 proposal, EPA received comments
recommending that it reconsider alternative methods for oil and grease.
Some of the comments focused exclusively on the oil and grease method
ASTM D7575. Unlike EPA Method 1664A which uses n-hexane as the
extractant and gravimetry for the measurement of the extracted
materials, ASTM D7575 uses an extracting membrane followed by infrared
measurement of the sample materials that can be retained on the
membrane. In particular, commenters cited that ASTM D7575 is solvent
free and provides reliable and comparable results to EPA Method 1664A.
These commenters submitted additional information on the health hazards
associated with hexane as well as additional single laboratory
comparability data between Method 1664A and ASTM D7575 and on
additional matrices tested after the initial comparability study and
associated statistical analysis.
Because EPA is interested in promoting the use of solvent-free
methods and this new information, EPA re-evaluated the ASTM D7575
method for the measurement of oil and grease and published a Notice of
Data Availability on December 14, 2011 (76 FR 77742). The notice
provided the additional data and EPA's analysis of that data. Further,
it explained that, after evaluating the new information, EPA was re-
considering its decision not to include ASTM D7575 in 40 CFR Part 136
as an alternative to EPA Method 1664A for measuring oil and grease. The
notice explained that EPA had three primary reasons for this re-
consideration. First, EPA's analysis demonstrates ASTM D7575 is an
acceptable stand alone method for the measurement of oil and grease in
wastewater for its applicable reporting range (5-200 mg/L). Second, it
produces results that, while not statistically comparable across all
matrices tested,\1\ are generally very close to those obtained using
EPA Method 1664A for the matrices tested. Third, EPA supports pollution
prevention, and is particularly persuaded by the substantial advantages
associated with the green aspects of this membrane technology (e.g., it
uses a solventless extraction, there is no
[[Page 14459]]
solvent waste, and no exposure of the analyst to solvent).
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\1\ Similar to the approach it used when it replaced Freon with
hexane, EPA performed a RMSD evaluation of the ASTM D-7575 results
and EPA Method 1664A results for the available matrices evaluated.
See 76 FR 77745.
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However, the notice also discussed implementation considerations
associated with promulgating an alternative method based on a different
determinative step for a method-defined parameter. EPA recognized the
potential impact that this new method could have on the hundreds of
thousands of oil and grease determinations in regulatory Clean Water
Act programs, and, as such, was keenly interested in obtaining
additional input from stakeholders. Therefore, the notice explained
that, while EPA determined that the results of the EPA 1664A and ASTM
D7575 are comparable over the applicable range where the two methods
overlap (5-200 mg/L) for the set of the 13 wastewater matrices
evaluated, it continued to have compliance concerns with promulgating
the ASTM method for nationwide use as an alternative to EPA Method
1664A. More specifically, because oil and grease measures a wide
variety and type of individual compounds and because oil and grease is
extensively incorporated in permits covering a wide variety of
wastewater matrices, the result of promulgating the ASTM D7575 method
as an alternative to EPA Method 1664A is that a permittee could be in
or out of compliance simply due to a change in the test method used to
evaluate samples.
Finally, through the notice, EPA requested comment on its
conclusion that ASTM D7575 is an acceptable choice for the
determination of oil and grease, and whether it should reconsider its
policy towards method-defined parameters for this particular method. In
particular, the notice requested comment on whether or not EPA should
reconsider promulgating this specific additional method for oil and
grease based on different extractants and determinative techniques than
EPA Method 1664A. Further, in the event that EPA were to promulgate
this specific alternative method, the notice requested comment on some
approaches that could ensure comparability for individual permittees
(e.g., EPA requested comment on the need for a permit adjustment based
on side-by-side comparison of Methods 1664A and ASTM D7575).
G. Summary of NODA Comments
EPA received comments from 106 stakeholders. Approximately, a third
expressed support for nationwide approval of the ASTM D7575 method as
an alternative oil and grease method. In general, these comments were
similar to those received on EPA's proposal: ASTM D7575 is ``green''
(e.g., less hazardous waste, no exposure to toxic chemicals), it is
easier, faster, less expensive and potentially portable in comparison
to EPA 1664A, and it produces results substantially in agreement with
Method 1664A. About two-thirds of the comments recommended EPA not
approve it for use as an alternative oil and grease method. Some
comments were specific to the sampling requirements and sample
preparation procedures of the method, raising technical concerns such
as the representativeness of the 10 mL aliquot and concerns over the
drying procedures. Some comments were more overarching such as comments
that ASTM D7575 had not been tested in a sufficient number of matrices.
Others were specific to the consideration of the ASTM D7575 method as
an alternative to EPA method 1664A, such as the applicable range of the
ASTM D7575 method (5 to 200 mg/L) was limited in comparison to EPA
Method 1664A. Some noted that the ASTM method did not produce
statistically comparable results to EPA Method 1664A and EPA should
retain its policy not to approve alternative methods for method-defined
parameters that are not based on the same determinative step. Finally,
many shared the concerns raised in the notice about implementing ASTM
D7575 on a nationwide basis as an alternative oil and grease method and
the possibility that a discharger could be in or out of compliance
simply by changing the method.
III. Final Determination on ASTM D7575 as an Alternative to Existing
Part 136 Oil and Grease Methods
As explained in the NODA, EPA's consideration of ASTM D7575
represents a unique situation. Because oil and grease is a method-
defined parameter, EPA has not considered promulgating multiple methods
to measure oil and grease that are based on different extractants.
Moreover, EPA has not considered multiple oil and grease methods that
are based on different determinative techniques. The only exception to
this was EPA's promulgation of EPA Method 1664A to replace Method
413.1, a similar procedure that used (the internationally banned
extraction solvent) Freon[supreg]. Thus, EPA's consideration of ASTM
D7575 as an alternative oil and grease method represents a new path for
EPA. As is always the case, EPA proceeded carefully, with a particular
focus on the underlying data. This consideration is specific to ASTM
D7575 and should not be interpreted broadly to other oil and grease
methods that use different extractants and/or determinative techniques,
or more generally to other method-defined analytes. If EPA receives
similar requests for other methods, it will evaluate each one
individually.
A. ASTM D7575 Is a Good Stand Alone Method for the Measurement of Oil
and Grease in Aqueous Matrices
After careful consideration of all the comments received on the
NODA, EPA continues to conclude that ASTM D7575 is a good stand alone
method for the measurement of oil and grease as defined by the method.
The method was single- and multi-lab tested following ASTM Standard
Practice D2777 (Standard Practice for the Determination of Precision
and Bias of Applicable Test methods of Committee D19 on Water) and
produced recoveries and precision as good as or better than EPA Method
1664A for those matrices tested and in the range of ASTM D7575
applicability (5-200 mg/L). Further, EPA is not persuaded by the
technical comments it received on the method itself. For example, the
representativeness of a well homogenized sample used was adequately
demonstrated by the replicate studies in the validation tests. See
docket number EPA-HQ-OW-2010-0192 for responses to these and all other
NODA comments.
B. ASTM D7575 as an Alternative Oil and Grease Method in 40 CFR Part
136
After careful consideration of all the comments received on the
NODA, EPA concludes that the case has not yet been made that ASTM D7575
should be approved for nationwide use as an alternative oil and grease
method. EPA has multiple reasons supporting this conclusion. First,
ASTM D7575 is not applicable to the same range and matrices as the
existing Part 136 oil and grease methods. ASTM D7575 is applicable for
measuring oil and grease from 5 mg/L to 200 mg/L while EPA Method 1664A
is applicable for measuring oil and grease from 5 mg/L to 1,000 mg/L.
Additionally, as explained in Note 2 in the method, ASTM D7575 is not
appropriate for certain samples where the solid matter is not
sufficiently IR transmitting, such as those that contain high levels of
metal particulates. Further, EPA Method 1664A also quantifies non-polar
oil and grease (SGT-HEM) while ASTM D-7575 does not.
Second and more importantly, EPA continues to share the concerns
raised by many commenters. Given that the two methods measure a method-
defined parameter, by definition, they cannot measure the same thing.
Consequently, because of the wide variety and type of
[[Page 14460]]
individual compounds that may be measured as oil and grease and because
oil and grease is extensively incorporated in permits covering a wide
variety of wastewater matrices, a permittee could be in or out of
compliance simply due to a change in the test method used to evaluate
samples. EPA continues to conclude such concerns are well founded for
the following reasons. First, oil and grease is a method-defined
parameter. That is, the results are dependent on the particular method
used. As ASTM D7575 uses a different determinative step than the
existing approved methods, one would not expect the results to be the
same for all applications. Second, the results of ASTM D7575 have been
evaluated on a relatively limited number of matrices (13) in comparison
to the extensive number and types of possible applications. In
contrast, when EPA promulgated Method 1664A to replace the previous
Freon-based method, it evaluated the two methods on a much more
extensive and wide variety of matrices (approximately 35). Third, the
data evaluated to date demonstrate that while ASTM D7575 produces
results that are generally very close to the approved method for the
set of matrices evaluated, they are not statistically comparable
results. As such, the concerns that the two methods may produce
different results are well founded.
However, EPA also recognizes that a blanket conclusion that one can
never promulgate new methods for method-defined parameters based on a
different determinative technique leaves little room for technology
improvements. Furthermore, EPA is keenly interested in supporting the
development and use of ``green'' methods such as ASTM D7575 that do not
require solvents. As such, EPA considered various approaches for
allowing its use as an alternative to approved methods while minimizing
the well founded concern that the two methods may affect compliance. In
other words, in those applications where the two methods produce
results that are comparable enough not to affect compliance, EPA wants
to encourage the use of non-solvent based methods such as ASTM D7575.
On the other hand, EPA wants to prevent the use of ASTM D7575 in those
applications where the two methods differ in their results and have the
potential to affect a facility's compliance status. Here, there simply
is not enough data to make a nationwide determination. Until such time
that EPA has enough data to make such a determination, EPA has
concluded such determinations should be made on a case by case basis
rather than a nationwide basis. As a result, EPA has decided not to
approve ASTM D7575 as an alternative oil and grease method in Part 136.
EPA also considered a novel approach in which it would approve ASTM
D7575 as an alternative oil and grease method in Part 136 with a
requirement to demonstrate comparability (side-by-side data) to the
permitting authority. To determine comparability for a specific
application, a permittee could use the specific side by side comparison
procedures recommended in the guidance document that was developed when
Method 1664A was promulgated (see''Analytical Method Guidance for EPA
Method 1664A Implementation and Use (40 CFR part 136),'' EPA/821-R-00-
003, February 2000). Under this approach, a permittee would only be
able to use ASTM D7575 if the recommended procedures demonstrated
comparability. This approach would provide for a non-solvent based
alternative to measuring oil and grease and eliminate the compliance
concerns noted above. This approach would be novel because EPA has
never approved a method for nationwide use with such a requirement. As
explained in Section II.A, the purpose of promulgating Part 136 methods
for nationwide use is to simplify the permitting process and reduce
burden to the permittees and the permitting authority (often the
state). As a result, EPA consulted with various permitting authorities
on this consideration. Feedback from permitting authorities indicated
that reviewing side by side comparison data would be a huge burden on
the states and that many POTWs lack both the expertise and staff to
conduct a side by side comparison. As a result, EPA rejected this
approach.
C. ASTM D7575 as an Alternative Oil and Grease Method in Permit
Specific Applications
In EPA's effort to promote the use of newer and more efficient
methods, EPA looked at a third option--the use of EPA's Alternate Test
Procedures process spelled out in the regulations at 40 CFR 136.5. EPA
considered this approach for encouraging and allowing the use of ASTM
D7575 while eliminating the associated compliance concerns using
existing regulatory authority. As explained in Section F, EPA
recognizes that new technologies and approaches are constantly being
developed and, as such, Part 136 currently allows for permittees to
gain approval of the use of an alternate method for a specific
application at a facility or type of discharge that is different from
the approved test procedure. Therefore, the authority already exists
under Sec. 136.5 for a permittee to request the use of ASTM D7575 as
an alternative oil and grease method for a specific use (i.e. limited
use ATP). The burden to review such requests rests on the EPA Regional
ATP Coordinators rather than the permitting authority which is often a
state or a local control authority. As such, EPA encourages permittees
to carefully consider whether or not ASTM D7575 is an acceptable
alternative to the existing methods for their specific matrix and, if
supported by data, to make such requests to their Regional ATP
Coordinator. To the extent that such requests are widespread, EPA
headquarters will provide technical support to the Regional ATP
Coordinators.
Part 136 already stipulates that an applicant must provide
comparability data for the performance of the proposed method compared
to the reference method to eliminate compliance concerns. EPA
anticipates that requests for the use of ASTM D7575 as an alternative
oil and grease method could be widespread, thus EPA wants to ensure
that such requests are handled consistently. To that end, EPA
recommends that applicants demonstrate comparability by conducting a
side-by-side comparison using the specific procedures (e.g. sampling
frequency, number of samples, QA/QC, and statistical analyses)
recommended in the guidance document that was developed when Method
1664A was promulgated [Analytical Method Guidance for EPA Method 1664A
Implementation and Use (40 CFR part 136), EPA/821-R-00-003, February
2000]. Comparability could be shown if this side by side comparison
demonstrates there is not a significant difference between the
promulgated method and ASTM D7575. Finally, EPA notes that such
requests may provide sufficient additional data that may allow EPA at a
later date to later make a nationwide determination on the approval of
ASTM D7575 as an alternative oil and grease method.
IV. New Docket Materials
1. Response to Comment document
2. Response from ASTM re: technical questions
3. Memo describing outreach to states and control authorities on burden
4. May 14, 1999 Federal Register (64 FR 26315)
5. ``Analytical Method Guidance for EPA Method 1664A Implementation and
Use (40 CFR
[[Page 14461]]
part 136),'' EPA/821-R-00-003, February 2000
Dated: February 27, 2013.
Nancy K. Stoner,
Acting Assistant Administrator.
[FR Doc. 2013-05248 Filed 3-5-13; 8:45 am]
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