# Enhanced Monitoring Program

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URL: https://www.frixlaw.com/law-library/documents/fr%3A94-31742

## Record

- **Collection:** Federal Register
- **Document type:** Uncategorized Document
- **Published:** December 28, 1994

## Text

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 51, 52, 60, 61 and 64

[FRL-5128-3]

Enhanced Monitoring Program

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule; reopening of public comment period.

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SUMMARY: EPA is soliciting comment on a limited set of revisions to its
proposed Enhanced Monitoring Program. EPA received numerous comments on
a wide range of issues pertaining to the October 22, 1993 proposed
rulemaking for a new 40 CFR part 64. EPA is issuing this notice to take
additional comment on a limited number of specific issues concerning
the proposed regulations. First, the Agency is considering phasing in
the implementation of the program over a five year period. This
implementation approach would allow for the Agency to develop guidance
on acceptable enhanced monitoring protocols for many types of affected
emissions units in order to streamline the selection and approval of
enhanced monitoring. Second, EPA seeks comment on the consideration of
cost in selecting and approving enhanced monitoring protocols. Third,
the Agency seeks comment on a second phase of applicability for
nonattainment areas and on specifically adopting periodic monitoring
under 40 CFR part 70 as sufficient enhanced monitoring for applicable
emissions units that do not meet the emission level applicability
thresholds for part 64 enhanced monitoring. The range of issues on
which EPA is soliciting comment is strictly limited to those issues
identified in this notice.

DATES: Comments on the issues discussed in this notice must be received
by January 27, 1995.

ADDRESSES: Comments: Comments must be mailed (in duplicate, if
possible) to: EPA Air Docket (LE-131), Attention: Docket No. A-91-52,
Room M-1500, Waterside Mall, 401 M Street SW., Washington, DC 20460.
Comments should refer to page numbers and columns whenever possible.
Only comments addressing the specific issues identified below will be
considered.
Docket: Supporting information used in developing the regulations
is contained in Docket No. A-91-52. This docket is available for public
inspection and copying between 8 a.m. and 5:30 p.m. Monday through
Friday, excluding government holidays, and is located at: EPA Air
Docket (LE-131), Room M-1500, Waterside Mall, 401 M Street SW.,
Washington, DC 20460. A reasonable fee may be charged for copying.

FOR FURTHER INFORMATION CONTACT: Scott Throwe, U.S. Environmental
Protection Agency, Office of Enforcement and Compliance Assurance,
Manufacturing, Energy and Transportation Division, at (202) 564-7013.

SUPPLEMENTARY INFORMATION:

I. Purpose of Today's Notice

EPA received numerous comments on many issues in response to the
October 22, 1993 proposal to adopt an Enhanced Monitoring Program. The
EPA has reviewed those comments, and has engaged in a series of
discussions with a wide range of members of the public, including State
and local governments, affected industries, and environmental groups.
(Summaries of those discussions are contained in Docket No. A-91-52.)
Based on EPA's review of the written comments received, and in light of
the views presented by the parties noted above, EPA has determined that
it would be appropriate to reopen the comment period to solicit
additional comments on a limited number of issues. The EPA is
soliciting comment on the following issues: phasing in the
implementation of the Enhanced Monitoring Program over a five year
period, including a process for developing guidance on example
protocols and an implementation deadline that together would establish
the timing for phasing in the program; the consideration of cost in
proposing and approving enhanced monitoring protocols; a second phase
of applicability in nonattainment areas; and the adoption of periodic
monitoring under 40 CFR part 70 as sufficiently enhanced monitoring for
applicable emissions units that do not meet the emissions level
applicability thresholds for part 64 enhanced monitoring. The Agency
believes it is useful to reopen the comment period in this limited
manner in order to be certain that EPA has the benefit of a full range
of views on these topics.
This rulemaking is subject to a court-ordered deadline established
by a consent decree in Sierra Club v. Browner, No. 93-0124 (NHJ)
(D.D.C.). The original September 30, 1994 deadline for completion of
this rulemaking was extended by the court at the request of the parties
to December 20, 1994. The parties have agreed to request that the court
extend the deadline again, to April 30, 1995 in order to accommodate
this limited revision to the original rulemaking proposal and reopening
of the comment period. The EPA believes that most of the issues
addressed in the October 22, 1993 proposal have been fully addressed in
the numerous detailed comments already received. For this reason, and
in order to meet the court-ordered deadline and ensure that the
Enhanced Monitoring Program is promulgated without undue delay, the
scope of issues addressed in this notice is limited. The Agency will
not consider comments submitted on issues that are not related
specifically to those addressed in this notice. The issues on which EPA
is soliciting comment are set forth below.

II. Implementation

The proposed regulations would require that the owner or operator
of a major stationary source propose an enhanced monitoring protocol as
part of an application for a permit under the operating permits program
pursuant to title V of the Act. In the public comments received on the
proposed regulations, many commenters expressed concern about the
burden of the enhanced monitoring protocol selection process on the
operating permits program process. Many commenters suggested modifying
the implementation approach to address their concerns regarding burdens
associated with the permit process. Some commenters suggested that EPA
engage in rulemaking to determine nationally applicable enhanced
monitoring protocols for each source category as opposed to a permit-
based implementation approach. Others suggested separating the protocol
approval process from the permit approval process. Finally, still other
commenters suggested phasing in the implementation so that permitting
authorities would not be required to implement the entire enhanced
monitoring program in the first round of permits without the benefit of
national guidance on example enhanced monitoring protocols.
Because of the concerns about burdens to the permit process, EPA is
considering phasing in implementation of the enhanced monitoring rule
over a five year period. The implementation approach would have several
elements. First, EPA would develop guidance on presumptively acceptable
protocols that may be used for particular process/pollutant
combinations. In referring to ``process/pollutant combinations,'' the
Agency is referring to emissions units classified on both a pollutant-
specific basis and on a process-specific basis, including the
applicable pollutant control measures, and, where appropriate, the
nature of the emission limitation or standard. For example, one
process/pollutant combination could be SO2 emissions from a coal-fired
boiler using a scrubber to achieve compliance with an SO2 standard
expressed in lbs/mmBtu, while another could be a similar boiler using
low sulfur coal to achieve compliance with a sulfur-in-fuel limit.
After EPA issues guidance for a particular process/pollutant
combination, the owner or operator of an affected source that includes
such a combination for an emissions unit subject to part 64 would be
required to propose an enhanced monitoring protocol as part of the
operating permit application for the applicable emissions unit. Except,
as discussed below, sources generally would not be required under part
64 to propose a protocol in the absence of EPA guidance. The protocol
may be based on a presumptively acceptable example protocol developed
by EPA or a different monitoring approach that can satisfy the part 64
criteria. If the permitting authority has published a notice requesting
public comment on a draft title V permit before EPA issues applicable
guidance for a particular process/pollutant combination, then an
enhanced monitoring protocol would not have to be proposed for that
emissions unit until either a reopening of the permit that involves
public notice and comment, or the next renewal of the permit.
Finally, to ensure timely implementation of the program, EPA would
incorporate a ``hammer'' provision that would be triggered on January
1, 2000. Under this provision, any title V operating permit issued
after the effective date of the ``hammer'' provision would have to
include enhanced monitoring for emissions units subject to part 64. In
addition, any existing permit that does not include an enhanced
monitoring protocol where one would have been required by part 64 in
the absence of phased implementation would have to be reopened
expeditiously to incorporate enhanced monitoring. This ``hammer''
provision would apply regardless of whether EPA has issued guidance for
a particular process/pollutant combination.
Nothing in this phased approach would prevent a State from
requiring that enhanced monitoring comporting with the part 64 criteria
be included in a title V operating permit at any time before EPA's
guidance for the relevant pollutant/process combination is available.
The following outline describes in more detail each of these
particular elements of EPA's suggested implementation approach. The
Agency believes that its suggested approach alleviates many of the
burdens associated with trying to implement enhanced monitoring in the
first round of operating permits. The Agency's guidance development
process would serve as a means of assisting sources and permitting
authorities alike in implementing the program. At the same time, this
approach would assure that enhanced monitoring is adopted in a timely
manner at all affected emissions units. The EPA requests specific
comment on this suggested approach to phasing in the program. The
Agency solicits suggestions on any variations on this approach that
commenters believe would reduce burdens on the permitting process while
assuring timely adoption of enhanced monitoring protocols at affected
emissions units.

A. Guidance Development Process

As discussed in the preamble to the proposed rule (see 58 FR
54658), EPA is preparing an Enhanced Monitoring Reference Document that
will serve as guidance on the implementation of the Enhanced Monitoring
Program and that will include example protocols that can be used by
various types of emissions units with respect to specific process/
pollutant combinations. The Agency noted in the preamble to the
proposed rule that EPA intended this document to be a compendium of
available monitoring that would be updated on a regular basis.
Under the implementation approach described in this notice, the
purpose of the Enhanced Monitoring Reference Document would change in
some important respects. First, EPA would issue guidance for a given
process/pollutant combination only after a notice of availability of
the example protocol in draft form is published in the Federal
Register, with an opportunity for the public to respond in writing. The
Agency would commit to publishing example protocols for a wide variety
of process/pollutant combinations over the next four years, with many
examples scheduled to be completed by the end of 1995. In addition, the
examples published in the Enhanced Monitoring Reference Document would
serve as presumptively acceptable protocols for the type of process/
pollutant combinations covered by the individual protocols.
This approach would allow owners or operators and permitting
authorities to rely on the examples in the Enhanced Monitoring
Reference Document to a greater extent than contemplated in the
preamble to the proposed rule. However, the Agency notes that the
guidance is intended to remain as guidance, and would not be a binding
regulation. Thus, owners or operators would not be required to use
these example protocols where an alternative protocol would satisfy the
part 64 criteria. The Agency emphasizes that the flexibility in the
proposed rule to propose other monitoring satisfying the criteria in
the rule would be retained.
The Agency intends to develop presumptively acceptable protocols in
a manner that assures the broadest coverage of process/pollutant
combinations as expeditiously as possible while providing interested
parties the opportunity for input. One issue on which the Agency is
soliciting comment is the prioritization for developing example
protocols, including how to group example protocols to allow cost-
effective collection of supporting data and other technical background
information while at the same time ensuring that the most
environmentally significant protocols are completed expeditiously.
The Agency also solicits comment on whether and how to use
particular types of tools for evaluating the degree of confidence that
a particular monitoring methodology can provide in demonstrating
compliance. In particular, the Agency is considering a ``Data Quality
Objectives'' (DQO) process for protocol evaluation where EPA guidance
is not available or in circumstances in which a source proposes an
alternative to EPA's example protocol, although a DQO process may also
be helpful to EPA in developing its example protocols. (Item No. IV-A-3
in the docket for this rulemaking provides a detailed description of
this process.) Recognizing that all measurements have imprecisions, EPA
staff have developed the DQO process for application to environmental
data collection programs. The DQO process is a systematic method for
designing and evaluating any data collection activity, including the
development and evaluation of many types of enhanced monitoring
protocols. The process can account for the effects of process or
emissions variability, margin of compliance, measurement precision, and
frequency of data collection or measurements in designing an enhanced
monitoring protocol. The DQO procedure is very similar to other
statistical procedures used in the manufacturing and chemical process
industries to optimize equipment design and production operations.
The application of the DQO process to protocol development and
review would reduce uncertainty about whether a proposed protocol will
be accepted and will promote consistent decisions on review of
protocols. Application of the DQO process requires the establishment of
an acceptable level of probability of compliance assurance that
enhanced monitoring data must meet when the affected emissions unit is
emitting near or over the applicable emission limit. The appropriate
level for the probability limit is an issue for which the Agency
requests comment. The probability level selected will necessarily
affect protocol design. For example, a low probability of error (e.g.,
less than 5 percent) may dictate more frequent, and thus, costly,
sampling than a higher probability (e.g., 10 percent or higher). In
another example, the probability level selection may be linked to the
risk associated with a particular emission, that is, a lower
probability may be applied for higher risk emissions monitoring systems
data. The data needed to calculate these probabilities can be obtained
through field tests, historical data, quality assurance/quality control
documentation (e.g., measurement method precision), data from tests at
similar sources, or engineering and scientific literature.
In return, the DQO process would provide the owner or operator and
the permitting authority a method for evaluating enhanced monitoring
protocol design effectiveness. It also would allow for significant
flexibility in protocol design regarding which parameters should be
monitored, frequency of data collection, and margin of compliance. The
result should be cost-effective protocols that meet the data quality
criteria in part 64.
The DQO process would provide an iterative planning method for the
design of the enhanced monitoring protocol. The process leads to a
mathematical determination of the probability of decision errors
associated with reported protocol values. The DQO process might also
optimize the protocol design process by identifying the most effective
data collection and analysis design for the protocol that will satisfy
the DQOs. This element of the process may include additional data
collection on alternative protocol designs, formulating additional
mathematical expressions, or redefining the sample size or measurement
frequency.
With respect to this DQO process, the Agency requests specific
comment on three issues: (1) the usefulness or limitations of the DQO
approach to protocol design; (2) the acceptable probability level of
data quality or compliance assurance, and appropriate mathematical
approaches for determining the probability; and (3) examples of cost-
effective protocols demonstrating a known high level of assurance of
continuous compliance using DQO analysis principles.
The Agency also requests comment on the possibility of using
independent third parties to evaluate protocols proposed by sources
particularly where a source proposes an alternative to a presumptively
acceptable example protocol provided by EPA. The use of third parties
could increase confidence in the protocol development and review
process and reduce the resource burdens associated with enhanced
monitoring protocol review and approval. The Agency is considering the
idea of using third-party reviewers through a public/private
partnership between the Agency and interested industrial organizations.
The Agency has in the past relied on outside parties to streamline
implementation of programs, such as certifying laboratories in
connection with the certification of woodstoves with NSPS requirements
under 40 CFR part 60, subpart AAA. The function of the third party
organization would be to review industry-submitted protocols for a fee
paid by the source owner submitting the protocol for review. The third
party would provide to the source owner or operators and the permitting
authorities an evaluation of the feasibility and acceptability of the
protocol for specific applications. The Agency is soliciting comment on
whether establishing a third party review process to augment permitting
authority review and evaluation of protocols is appropriate; what would
be a suitable structure for a third party review organization and
process; the suitability of the industry paid fee for the third party
review services or any alternative funding mechanism; and what
procedures (e.g., data quality objectives analysis) would be
appropriate to guide a third party review.
The Agency intends to provide for input from all interested parties
throughout the example protocol guidance development process. To assure
that all interested parties have an opportunity to comment, EPA intends
to publish in the Federal Register a notice of availability of example
protocols in draft form prior to incorporating those protocols into the
Reference Document A notice of availability of final example protocols
would also be published in the Federal Register. In addition, the
Agency will use its Technology Transfer Network (TTN) electronic
bulletin board to facilitate public involvement in the development and
review of guidance on example protocols. The Agency will make available
through the TTN initial information on the development of example
protocol guidance, as well as draft and final example protocols and
other pertinent information. Regular updates to the Enhanced Monitoring
Reference Document will be available on the TTN as well. The Agency
anticipates updating the Enhanced Monitoring Reference Document after
the five year phase-in period, as well as throughout the initial
implementation period, so that it continues to reflect advances in
monitoring techniques. The phone number for accessing the TTN is (919)
541-5742. Persons unfamiliar with the TTN but interested in using the
system should contact the TTN help desk at (919) 541-5384 for further
information.

B. Timing of Implementation

Under the proposed rule, owners or operators would be required to
submit proposed enhanced monitoring protocols with an application for a
title V operating permit. The approach that EPA is now considering
would delay implementation until EPA has published a notice of
availability of an example protocol (or protocols) for the type of
process/pollutant combination for which a protocol is required, subject
to the ``hammer'' provision described below. In the interim, the
monitoring requirements in 40 CFR 70.6(a)(3) and 70.6(c) would apply.
Following publication of the notice of availability of example
protocol(s) for a process/pollutant combination, the time at which the
owner or operator would be required to submit a proposed enhanced
monitoring protocol would depend on the status of the title V operating
permit for the applicable facility. If the initial operating permit
application has not yet been filed for the facility, then the owner or
operator generally would be required to include a proposed protocol in
the initial application for an emissions unit subject to part 64 that
includes the relevant process/pollutant combination. In some
circumstances, notice that EPA's example protocols are available may be
published shortly before an affected source is obligated to submit its
permit application to the permitting authority. In such circumstances,
the source may submit its application as scheduled and then update the
application to include enhanced monitoring no later than 90 days after
publication of the notice of availability.
If the operating permit application is filed before EPA publishes
notice of availability of example protocol(s) for a process/pollutant
combination applicable to emissions units subject to part 64 at the
affected source, but the permitting authority has not yet published a
notice to request public comment on a draft permit, then the owner or
operator would be required to update the permit application within 90
days of publication of the example protocols(s) to address enhanced
monitoring for the emissions units covered by the example protocol(s).
If an application is filed and a draft permit is noticed for public
comment before EPA publishes a notice of availability of applicable
example protocols, then the owner or operator would not be required to
submit a proposed protocol until the earlier of: (1) the next
application for permit renewal; or (2) a reopening of the permit that
involves public notice and comment that is consistent with the type of
public notice and comment required by 40 CFR part 70 for approval of an
enhanced monitoring protocol.
The ``hammer'' provision would limit the duration of the phased-in
implementation process. Where enhanced monitoring is not required for
an affected emissions unit and applicable requirement under the
implementation schedule outlined above, the ``hammer'' provision would
mandate implementation of enhanced monitoring as of January 1, 2000.
There are three different scenarios in which the ``hammer'' provision
would apply. First, an enhanced monitoring protocol must be included
where applicable under part 64 in any title V permit issued after the
``hammer'' deadline, even if EPA has not issued guidance on a
particular process/pollutant combination. Second, an existing title V
permit that has not included an enhanced monitoring protocol required
under part 64 because EPA has not yet issued guidance for the
applicable process/pollutant combination would have to be reopened
expeditiously after the January 1, 2000 deadline to incorporate
enhanced monitoring. Finally, where an existing title V permit has not
included an enhanced monitoring protocol because EPA has issued
guidance only after the date of notice for public comment on the draft
permit, the permit would have to be reopened expeditiously after the
January 1, 2000 deadline assuming that the required enhanced monitoring
protocol had not been approved previously during a permit renewal or
reopening. The Agency requests comment on appropriate timeframes for
processing permit actions where the ``hammer'' provision requires an
expeditious reopening of an existing permit.
The Agency believes that including this type of ``hammer''
provision is essential to assure that the program is implemented in a
timely manner. This ``hammer'' provision would provide an incentive for
all parties to facilitate the development of example protocol guidance.
The Agency also believes that the experience gained over the next five
years and the publication of guidance for many types of process/
pollutant combinations will facilitate effective implementation for the
limited number of process/pollutant combinations for which the Agency
may not develop guidance before the January 1, 2000 deadline. The
Agency believes that guidance will be available for most affected
emissions units before the end of this time period. The Agency requests
comment on this ``hammer'' provision.

III. Consideration of Cost

Many industry representatives and some other groups commented that
the proposed rule would not allow adequate consideration of the costs
of various monitoring approaches in selecting enhanced monitoring for a
particular emissions unit. The Agency requests comment generally on how
the final rule should address the issue of considering cost in the
context of protocol selection and approval and specifically on whether
the final rule should be clarified to allow owners or operators to
select the least-cost monitoring protocol that can achieve the
requirements in the rule.
Some comments from industry representatives indicate that cost also
should be a consideration where the only monitoring approaches that can
meet the other part 64 criteria are not cost-effective for the
particular emissions unit. The EPA finds this an important issue and is
considering incorporating a more explicit role for the consideration of
cost in the selection and approval of enhanced monitoring. In the
notice of proposed rulemaking (NPRM), EPA discussed in numerous places
the importance of designing an enhanced monitoring program that would
both achieve cost-effective emissions reductions and also allow sources
to adopt monitoring methods that would satisfy the enhanced monitoring
standards in the most cost-effective manner. EPA thus sees the
consideration of costs in establishing enhanced monitoring as
consistent with the NPRM and the Clean Air Act. The Agency requests
specific comment as to whether and how the final rule should allow the
Agency to consider cost and effectiveness in developing guidance for
monitoring protocols.
The Agency also requests comment on whether the final rule should
allow, on a case-by-case basis and upon a demonstration by the owner or
operator that no monitoring approach that satisfies all of the part 64
criteria is cost-effective, the owner or operator to propose a cost-
effective monitoring approach that comes as close as possible to
achieving all the other part 64 criteria. The Agency also requests
specific comment as to what procedures and criteria should be used by
permitting authorities to evaluate such proposals by owners or
operators.
If EPA adopts this approach, EPA would define enhanced monitoring
as representing the monitoring for determining compliance, taking cost
and effectiveness into account. The basic purpose of Section 114(a)(3)
and associated sections of the Clean Air Act is to require all major
sources to conduct monitoring which will allow them to certify
continuous or intermittent compliance. However, nothing in Section
114(a)(3) dictates that all sources must certify to being in either
continuous compliance or else be considered in noncompliance; sources
may also certify to being in compliance as demonstrated on an
intermittent basis. For example, by virtue of consideration of cost (or
because the emissions unit is below the applicability threshold for
part 64) a source may not have monitoring data that is sufficient to
support a certification of continuous compliance but does provide the
basis for certification on an intermittent basis. EPA emphasizes that a
certification of intermittent compliance does not mean that a source
has operated in violation of applicable requirements. Rather, it merely
reflects the fact that under some enhanced monitoring protocols, a
source will only be able to gather enough data to certify compliance on
an intermittent basis. In order to ensure effective implementation of
enhanced monitoring and to minimize the burden on the operating permits
program, any approach related to protocol cost would, in EPA's view,
need to allow the permitting authority to make an expeditious
determination based on simple, direct criteria.

IV. Special Applicability for Nonattainment Areas and Incorporation of
Periodic Monitoring

Many industry representatives and several State and local agencies
commented that the proposed applicability of the rule covered too many
sources and emissions units, especially too many small emissions units.
Environmental groups commented that the proposed applicability was too
narrow and criticized any reduction in applicability. In response to
these comments, the Agency solicits comment on whether it would be
appropriate to have a second phase of applicability only for
nonattainment pollutants in nonattainment areas.
The Agency is considering applying part 64 primarily to emissions
units which emit, or have the potential to emit, a pollutant at or
above the applicable major source threshold, as defined under title V
of the Act. This approach would have the effect of significantly
reducing the number of sources and emissions units subject to part 64.
To address concerns that environmentally significant emissions units
would not be covered, the EPA is also considering the appropriateness
of a second phase of applicability, only for nonattainment pollutants
in nonattainment areas, in which all major sources which are major for
a nonattainment pollutant would be required to cover a prescribed
minimum percentage of their emissions units, perhaps with a de minimis
cutoff for very small units.
In such a second phase, part 64 could require each major source
which is located in a nonattainment area and major for a nonattainment
pollutant to conduct enhanced monitoring on at least 25% of its
emissions units that are subject to applicable requirements for the
nonattainment pollutant, except that it would not have to conduct
enhanced monitoring for that pollutant on any emissions unit which
emits, and has the potential to emit, less than 50% of the applicable
major source threshold. Emissions units would be selected for coverage
as part of the 25% requirement based on the potential to emit of the
units, with the largest selected first. Any emissions units already
required to conduct enhanced monitoring under the regular, first phase
of implementation would ``count'' toward the 25%.
The EPA believes that this second phase of applicability is
appropriate as a means of ensuring that emissions units that have the
potential to contribute significantly to nonattainment problems are
subject to enhanced monitoring while at the same time excluding the
smallest emissions units.
The EPA solicits comment on the appropriateness of requiring such a
second phase only in nonattainment areas (i.e., not in attainment
areas); the appropriate percentage threshold to use; whether and at
what level a de minimis level should be used to exclude small emissions
units; when and how such a second phase should be implemented in
connection with the title V permitting process; and on all other
aspects of such a second phase in nonattainment areas. After reviewing
any comments received, EPA may proceed to finally promulgate a second
phase without further opportunity to comment.
The EPA realizes that the applicability approach described above
may still leave some major sources with no emissions units subject to
enhanced monitoring requirements in part 64. To satisfy the statutory
obligation that all major stationary sources conduct enhanced
monitoring, the preamble to the proposed rule stated EPA's intent to
rely on periodic monitoring under 40 CFR part 70 as sufficiently
enhanced for small units under the size threshold proposed by EPA. The
Agency also requested comment on the possibility of relying upon a de
minimis exemption theory as allowed under Alabama Power v. Costle, 636
F.2d 323 (D.C. Cir. 1979).
Accordingly, EPA solicits comment on the appropriateness of relying
in part on periodic monitoring under 40 CFR part 70 to satisfy the
Agency's obligation to require enhanced monitoring for all major
sources.
The Agency also solicits comment on whether to codify this link
between enhanced and periodic monitoring by specifically including the
rule language from 40 CFR 70.6(a)(3)(i) into a separate subpart of part
64. A separate subpart of part 64 could provide that at a major source,
for all emissions units and applicable requirements that do not meet
the applicability thresholds for the enhanced monitoring requirements
discussed in the proposed rule and in this notice, the source must
conduct monitoring, to the extent necessary to comply with 40 CFR
70.6(a)(3)(i) and 70.6(c)(1) and (5), that is periodic monitoring
sufficient to yield reliable data from the relevant time period that
are representative of the source's compliance with the permit. Such
monitoring requirements would be required to assure use of terms, test
methods, units, averaging periods, and other statistical conventions
consistent with the applicable requirement.
Such a codification of existing part 70 language into part 64 would
not be intended to alter, or add to, the existing part 70 monitoring
requirements. Rather, this codification would merely make clear that
EPA considers existing periodic monitoring requirements as partial
fulfillment of its obligation to require enhanced monitoring for all
major sources.
Finally, in a separate section above, the Agency discusses the
potential role of cost in selecting enhanced monitoring. In this
context, EPA may also consider periodic monitoring approaches under
certain circumstances as one of the ways of achieving more cost-
effective monitoring approaches.

Dated: December 20, 1994.
Carol M. Browner,
Administrator, U.S. Environmental Protection Agency.
[FR Doc. 94-31742 Filed 12-27-94; 8:45 am]
BILLING CODE 6560-50-P

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-31742. Public record. Not legal advice.