Alternative Work Practice To Detect Leaks From Equipment, 78199-78219 [E8-30196]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 73, Number 246 (Monday, December 22, 2008)]
[Rules and Regulations]
[Pages 78199-78219]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-30196]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 60, 63, and 65

[EPA-HQ-OAR-2003-0199; FRL-8754-5]
RIN 2060-AL98


Alternative Work Practice To Detect Leaks From Equipment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: Numerous EPA air emissions standards require specific work 
practices for equipment leak detection and repair. On April 6, 2006, we 
proposed a voluntary alternative work practice for leak detection and 
repair using a newly developed technology, optical gas imaging. The 
alternative work practice is an alternative to the current leak 
detection and repair work practice, which is not being revised. The 
proposed alternative has been amended in this final rule to add a 
requirement to perform monitoring once per year using the current 
Method 21 leak detection instrument. This action revises the General 
Provisions to incorporate the final alternative work practice.

DATES: This final action is effective on December 22, 2008.

ADDRESSES: Docket: EPA has established a docket for this action under 
Docket ID No. EPA-HQ-OAR-2003-0199. All documents in the docket are 
listed on the https://www.regulations.gov Web site. Although listed in 
the index, some information is not publicly available, e.g., 
Confidential Business Information or other information whose disclosure 
is restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available either electronically through https://www.regulations.gov or 
in hard copy at the Air and Radiation Docket Center (EPA/DC), EPA West 
Building, Room 3334, 1301 Constitution Ave., NW., Washington, DC. The 
Public Reading Room is located in the EPA Headquarters Library, Room 
Number 3334, and is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the Public 
Reading Room is (202) 566-1744, and the telephone number for the EPA 
Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Mr. David Markwordt, Office of Air 
Quality Planning and Standards, Sector Policies and Programs Division, 
Coatings and Chemicals Group (E143-01), U.S. EPA, Research Triangle 
Park, North Carolina 27711, telephone (919) 541-0837, facsimile (919) 
541-0246, e-mail markwordt.david@epa.gov.

SUPPLEMENTARY INFORMATION:
    Regulated Entities. The regulated categories and entities affected 
by this final rule amendment include, but are not limited to the 
following North American Industry Classification System (NAICS) code 
categories:

[[Page 78200]]



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                  Category                       NAICS Code        Examples of potentially regulated entities
----------------------------------------------------------------------------------------------------------------
Industry....................................               325  Chemical manufacturers.
                                                           324  Petroleum refineries and manufacturers of coal
                                                                 products.
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    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be affected by the 
national emission standards. To determine whether your facility is 
affected by the national emission standards, you should examine the 
applicability criteria in 40 CFR parts 60, 61, 63, and 65, including, 
but not limited to: Part 60, subparts A, Kb, VV, XX, DDD, GGG, KKK, 
QQQ, and WWW; part 61, subparts A, F, L, V, BB, and FF; part 63, 
subparts A, G, H, I, R, S, U, Y, CC, DD, EE, GG, HH, OO, PP, QQ, SS, 
TT, UU, VV, YY, GGG, HHH, III, JJJ, MMM, OOO, VVV, FFFF, and GGGGG; and 
part 65, subparts A, F, and G.
    Worldwide Web (WWW). In addition to being available in the docket, 
an electronic copy of this final rule amendment is available on the WWW 
through the Technology Transfer Network (TTN). Following signature, a 
copy of this final rule amendment will be posted on the TTN's policy 
and guidance page for newly proposed or promulgated rules at the 
following address: https://www.epa.gov/ttn/oarpg/. The TTN provides 
information and technology exchange in various areas of air pollution 
control.
    Outline. The information in this preamble is organized as follows:

I. Background Information
    A. What is the statutory basis for this action?
    B. What did we propose?
II. Summary of Changes to the Proposed Rule
    A. Removal of the Minimum Detection Sensitivity Level Defaults
    B. Annual EPA Method 21 Monitoring while Complying with the AWP
    C. Re-screening Repaired Equipment
    D. Recordkeeping for AWP Compliance
III. Response to Significant Comments
    A. Basis of Standard
    B. Applicability
    C. Rule Location
    D. Alternative Work Practice Procedures and Equipment 
Specifications
    E. Recordkeeping and Reporting
    F. Other Comments
IV. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children from 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations that 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions to Address 
Environmental Justice in Minority Populations and Low Income 
Populations
    K. Congressional Review Act

I. Background Information

A. What Is the Statutory Basis for This Action?

    Current leak detection and repair (LDAR) requirements are primarily 
applicable to sources through EPA work practice standards promulgated 
under Clean Air Act (CAA) section 111 (New Source Performance Standards 
(NSPS)) and section 112 (National Emission Standards for Hazardous Air 
Pollutants (NESHAP)). These sections authorize EPA to promulgate work 
practice standards in lieu of numerical emission standards when ``it is 
not feasible in the judgment of the Administrator to prescribe or 
enforce an emission standard'' because the regulated pollutants 
``cannot be emitted through a conveyance designed and constructed to 
emit or capture such pollutant * * * or [because] the application of 
measurement methodology to a particular class of sources is not 
practicable due to technological and economic limitations.'' 42 U.S.C. 
7412(h)(1), (2); see also 42 U.S.C. 7411(h)(1), (2).
    In promulgating such standards, we are not required to mandate a 
single work practice applicable to all sources in a source category but 
may instead provide several alternative work practice (AWP) options. 
Indeed, the United States Court of Appeals for the District of Columbia 
Circuit has indicated that EPA may provide sources with multiple work 
practice compliance options if EPA demonstrates that at least one of 
these options is cost effective and ``expressly provides for the 
alternative in the standard.'' Arteva Specialties S.R.R.L., d/b/a KoSa 
v. EPA, 323 F.3d 1088, 1092 (DC Cir. 2003).
    Once promulgated, EPA retains the authority to provide additional 
work practice alternatives. Such authority exists under EPA's general 
authority to review and amend its regulations as appropriate, e.g., 42 
U.S.C. 7411(b)(1)(B), 42 U.S.C. 7412(d)(6).

B. What Did We Propose?

    The proposed AWP allows owners or operators to identify leaking 
equipment using an optical gas imaging instrument instead of a leak 
monitor prescribed in 40 CFR part 60, Appendix A-7 i.e., a Method 21 
instrument. The new work practice requirements are identical to the 
existing work practice requirements except for those requirements which 
are directly or indirectly associated with the instrument used to 
detect the leaks; for example, owners or operators are still subject to 
the existing ``difficult to monitor,'' ``unsafe to monitor,'' repair, 
recordkeeping, and reporting requirements. If a leak is identified 
using the optical gas imaging instrument, then the leak must be re-
screened after repair using the imaging instrument.
    Owners or operators are required to use an optical gas imaging 
instrument capable of imaging compounds in the streams that are 
regulated by the applicable rule. The imaging instrument must provide 
the operator with an image of the leak and the leak source.
    Prior to using the optical gas imaging instrument, owners and 
operators are required to determine the mass flow rate that the imaging 
instrument will be required to image. The optical gas imaging 
instrument is required to either meet a minimum detection sensitivity 
mass flow rate (provided in the proposed AWP) or owners or operators 
can calculate the mass flow rate for their process by prorating a 
standard detection sensitivity emission rate (provided in the proposed 
AWP) using equations provided in the amendatory language. If the owner 
or operator chooses to prorate the standard detection sensitivity, they 
are required to conduct an engineering analysis to identify the stream 
containing the lowest mass fraction of chemicals that have to be 
identified as detectable.
    Owners or operators are required to conduct a daily instrument 
check to confirm that the optical gas imaging instrument is able to 
detect leaks at the emission rate specified in the amendatory language 
(or calculated by the owner or operator). The instrument check consists 
of using the optical gas imaging instrument to view the mass flow rate 
required to be met exiting a gas cylinder.

[[Page 78201]]

    Owners or operators using the AWP are required to keep records of 
the detection sensitivity level used for the optical gas imaging 
instrument; the analysis to determine the stream containing the lowest 
mass fraction of detectable chemicals; the basis of the mass fraction 
emission rate calculation; documentation of the daily instrument check 
(either with the video recording device, electronically, or written in 
a log book); and the video record of the leak survey.

II. Summary of Changes to the Proposed Rule

A. Removal of the Minimum Detection Sensitivity Level Defaults

    The proposed rule contained equations that could be used by 
facilities to adjust the detection sensitivity level (i.e., 60 g/hr) 
based on the composition of the compounds in the process lines. EPA 
also provided facilities the option of meeting a minimum detection 
sensitivity level in lieu of adjusting the detection sensitivity level.
    In the final rule, we removed the minimum detection sensitivity 
level. This change was made after reviewing concerns expressed by 
commenters that the minimum detection sensitivity level would allow an 
emissions loophole for high purity systems. (See Section III.A for 
rationale.)

B. Annual EPA Method 21 Monitoring While Complying With the AWP

    In the final rule, we are requiring owners or operators choosing to 
use the AWP to screen equipment using EPA Method 21 (i.e., Method 21) 
instead of the optical gas imaging instrument in one screening period a 
year. Owners or operators conducting the Method 21 screening must meet 
the requirements in the applicable subpart and keep records of all 
screened equipment. (See Section III.A of this preamble for rationale.) 
Records of the annual Method 21 screening are to be submitted to the 
Administrator via e-mail to CCG-AWP@EPA.GOV.

C. Re-Screening Repaired Equipment

    In the final rule, we are allowing owners or operators to re-screen 
equipment after being repaired using either the current work practice 
or the AWP if the leaks were detected using the AWP. Leaks detected by 
the current work practice must be re-screened using the current work 
practice. (See Section III.B of this preamble for rationale.)

D. Recordkeeping for AWP Compliance

    In the final rule, we are requiring that owners or operators keep 
records of the equipment, process units, or facilities that are to be 
included in the AWP to document that a facility has chosen to comply 
with the AWP. This documentation must be kept for as long as the AWP is 
used and the Administrator may request to review it. We are also 
requiring that owners or operators keep video records of the daily 
instrument check and the leak survey results. The video records must be 
kept for at least 5 years. (See Section III.E of this preamble for 
rationale.)

III. Response to Significant Comments

    The proposal provided a 60-day comment period ending, June 5, 2006. 
We received comments from 23 commenters. Commenters included State 
agencies, industry, industry trade groups, environmental groups and 
individuals. We have summarized the significant comments below. A 
complete summary of comments is provided in the response to comments 
document which can be found in Docket EPA-HQ-OAR-2003-0199.

A. Basis of Standard

    Comment: One commenter suggested that the basis of EPA's assessment 
of optical gas imaging is from data for sources never regulated for 
leaking equipment and is significantly outdated compared to current 
LDAR implementation.
    Response: As discussed in the proposal preamble (71 FR 17403), the 
most reasonable approach to determine if the AWP is equivalent to the 
original work practice (based on Method 21) is to model the emission 
reductions that would occur if you were to apply both programs on an 
uncontrolled facility. This allows for a direct comparison between the 
effectiveness of the two approaches. As explained in the proposal, the 
original uncontrolled baseline Method 21 data used to develop the 
existing work practice would have been appropriate to make the 
comparison. Unfortunately, this 25-year-old database is no longer 
available. The only uncontrolled data available is from natural gas 
processing plants, which are used in the modeled comparison. These 
plants were screened with Method 21 instruments in the early 1990s as 
part of an EPA/industry effort to develop emission factors for the 
refinery and gas processing industry.
    Comment: Several commenters opposed immediate and complete phase-
out of Method 21 because equivalency has not been proven and the 
optical gas imaging instruments have questionable ability to image 
materials emitted at the detection sensitivity level (i.e., threshold 
leak rates). Several commenters explained that the studies referenced 
by EPA do not take into account the fact that a single leak's emission 
rate will vary over time and depend on process conditions (such as 
chemical activity, temperature, and pressure), and the type and size of 
the equipment. One commenter suggested that EPA has presented no 
evidence to support the presumption that leaking equipment below the 
sensitivity of the optical gas imaging instrument will proceed to leak 
at a higher rate over time and be discovered due to increased frequency 
of monitoring. One commenter stated that if smaller leaks will not be 
detected with the gas imaging instrument, then a site may end up with 
many undetected small fugitive equipment leaks and could result in 
higher emissions rates.
    Another commenter asserts that optical gas imaging is not currently 
technically equivalent to Method 21 because the camera cannot detect 
small leaks of less than 60 grams/hour (g/hr). The commenter also 
stated that the side-by-side comparison of Method 21 and the optical 
gas imaging technology shows there are significant differences in the 
detection rate. The commenter questioned whether the increased 
frequency of monitoring to detect larger leaks will actually compensate 
for the camera's inability to detect small leaks. The commenter added 
that high risk leaks of carcinogens will continue to leak until they 
become large enough to be detected by the camera.
    Response: When using any imaging instrument, leak detection 
requires two primary factors for its use: (1) The leak definition and 
(2) the monitoring frequency. Together, these factors form the 
foundation of an LDAR program for identifying fugitive emissions from 
leaking equipment. The current work practice uses various leak 
definitions based on parts per million (ppm) and corresponding 
monitoring frequencies (monthly, quarterly, or annually) for 
identifying leaking equipment. Emissions reductions occur when leaking 
equipment is identified and repaired. In developing the AWP, EPA sought 
to design a program for using the optical gas imaging instrument that 
would provide for emissions reductions of leaking equipment at least as 
equivalent as the current work practice. To do so, we used the Monte 
Carlo model for determining what leak rate definition and what 
monitoring frequency were necessary for the AWP. The following provides 
a brief explanation of how we used that model to obtain the 60 g/hr 
leak rate threshold and a bi-monthly monitoring frequency. For a more 
detailed explanation of the

[[Page 78202]]

methodology used to develop the AWP, refer to the preamble for the 
proposed AWP (71 FR 17401).
    Based on a 1993 petroleum industry study, EPA developed a 
statistical relationship between measured (bagged) mass emissions and 
the associated measured Method 21 screening values. This statistical 
relationship established the probability of registering a Method 21 
screening value for a given range of mass emissions. The statistical 
relationship was then used to simulate detection of leaks by the Method 
21 work practice in the computer model. The modeling program compares 
the screening value of Method 21 to various leak definitions to 
determine if a leak would be detected. Similarly, the model assigns a 
mass rate detection limit to the AWP. For each piece of equipment with 
a leak at or above the assigned mass detection limit, the program 
specifies detection by the AWP. Modeling results showed a work practice 
repeated bimonthly with a detection limit of 60 g/hr range was 
equivalent to the existing work practice. The model generated different 
detection limits for the 500 and 10,000 ppm thresholds in existing 
rules. The final rule reflects the mass detection limit for 500 ppm, 
i.e., the most stringent limit in the Federal LDAR rules, thus, 
providing equivalency for both leak definitions.
    The final AWP is not phasing out the existing Method 21-based LDAR 
work practice standards. Rather, the final rule allows owners/operators 
to choose to use the AWP in place of the current work practice wherever 
applicable. When used, the AWP provides equivalent control and appears 
to be less burdensome to implement. Additionally, industry has 
purchased many optical gas imagers and has had the opportunity to 
become proficient with their use. For these reasons, we expect the AWP 
to quickly come into widespread use. We see no reason why this is not a 
good outcome, especially given, as discussed below, that the final AWP 
includes an annual Method 21 monitoring requirement.
    We disagree with the commenter's assertion that optical gas imaging 
cannot detect leaks at or less than 60 g/hr. The tests conducted using 
various optical imaging devices have shown that many gas imaging 
instruments detect emissions significantly below the 60 g/hr limit 
(Docket ID No. EPA-HQ-OAR-2003-0199-0027). Moreover, equivalence has 
been shown at a 60 g/hr leak rate, so it is not necessary that the 
optical gas imager detect leaks smaller than this level.
    We also disagree that the side-by-side comparison of Method 21 and 
the AWP shows significant differences in mass of emissions detected. 
Available test data that we have reviewed shows that most of the mass 
emissions were detected by both Method 21 and the AWP (Docket ID No. 
EPA-HQ-OAR-2003-0199-0027, and the response to comments document which 
can be found in Docket EPA-HQ-OAR-2003-0199). The commenter did not 
provide data to support their assertion otherwise.
    However, we recognize that modeling cannot address all of the 
uncertainties associated with equipment leaks because we lack 
sufficient information necessary to address all of the potential issues 
such as leak rates varying with time or with different operating 
scenarios. While commenters suggest these factors could affect the 
modeled equivalency determination, we are not aware of any specific 
data that shows this affect is real or that would allow us to include 
it in the equivalence modeling. As an example, one question not 
addressed by the modeling effort is the possibility that leak rates of 
the emitters below the imaging threshold of 60 g/hr will increase with 
time but stay below 60 g/hr and, therefore, not be imaged by the AWP. 
If the leak rate for the equipment currently leaking below the 
detectable threshold of the AWP gradually increases but stays below the 
detectable threshold, some situations may arise where cumulative 
emissions could exceed those emitted under the current program. We do 
not have evidence to support this scenario; however, we believe it 
prudent to protect against this scenario. Therefore, the final AWP 
requirements provide a transition to the new imaging technology. We 
have added an annual Method 21 screening to the AWP to address the 
concern of small leaks growing but not large enough to be detected with 
optical imaging. This requirement would take the place of one of the 
optical imaging screening surveys. The Method 21 screening must be 
conducted using the leak detection and repair requirements in the 
applicable subpart to which the equipment is subject and must be 
conducted for all equipment that are included in the AWP. Records of 
the annual Method 21 screening results must be kept. Records must 
identify the equipment screened, the screening value measured by Method 
21, the time and date of the screening, and calibration information 
required in the existing applicable subparts. We recognize that 
including an annual Method 21 screening survey in the AWP will decrease 
the cost savings that may have occurred under the proposed requirement; 
however, we fully expect that the costs of the final AWP will be 
substantially less than those of the current work practice, so we hope 
that the added costs will not deter facilities from adopting the final 
AWP.
    As industry adopts the AWP and reports to us their records of the 
results of the annual Method 21 monitoring, we will review this data to 
assess the extent to which small leaks go undetected and become larger 
while remaining undetected. We will consider these results, along with 
other relevant information, in any future revisions to the AWP.
     Comment: One commenter requested EPA explain the relationship 
between the 60 g/hr threshold and the 500, 1,000, 2,000, and 10,000 ppm 
concentration cutoffs in the existing LDAR regulations. The commenter 
suggested that EPA set up different leak definitions to recognize that 
some equipment inherently leak less material than others and thus only 
need to be repaired after reaching the specified leak level. The 
commenter also indicated that the increased leak definition for auto-
polymerizing compounds were included in most LDAR regulations to 
recognize that these materials are less likely to leak into the 
atmosphere. The commenter concluded that the 60 g/hr leak threshold 
does not recognize any of the specific situations that have caused EPA 
to promulgate these provisions.
    Two commenters suggested that the equivalency analysis does not 
show that the gas imaging leak threshold of 60 g/hr is equivalent to a 
Method 21 measurement of 500 ppm, especially when connectors and other 
equipment are considered. Another commenter added that another study 
showed that an equivalent leak threshold for flanges is 24 g/hr instead 
of 60 g/hr. The commenter requested that EPA justify applying the same 
leak threshold to virtually all types of equipment. The commenter also 
stated that another study showed the equivalent leak threshold for 
valves was 36 g/hr, and suggested using this stricter standard.
     Response: The explanation of the relationship between the 60 g/hr 
leak threshold and various leak definitions is provided in EPA's 
discussion of the Monte Carlo analysis (Docket ID No. EPA-HQ-OAR-2003-
0199-0005). Additionally, as explained in the response above, the 
equivalency determination was based on comparing the current work 
practice leak definition and monitoring frequency requirements with 
various leak rates and monitoring frequencies generated by the Monte 
Carlo model. We modeled the most stringent leak definition (500 ppm) to

[[Page 78203]]

determine the leak threshold for the AWP under the assumption that if a 
source could meet the most stringent leak threshold, it could meet less 
stringent leak definitions in any of the Federal equipment leak 
standards.
    The 60 g/hr leak threshold, when monitored bi-monthly, is the 
modeled equivalent for the vast majority of LDAR programs. Other 
equipment subject to LDAR rules is monitored at a higher leak 
definition (i.e., 1,000 ppm, 2,000 ppm, 10,000 ppm) and monitored less 
frequently (i.e., quarterly or annually). Thus, facilities using the 
AWP to monitor these other pieces of equipment should see results at 
least as stringent as using the current work practice. We lacked 
sufficient bagging data on other equipment to develop correlations 
using the model. However, the bagging data for those other pieces of 
equipment could be, and was, used to validate the results from the 
Monte Carlo analysis.
    One commenter referred to an industry study showing that if a 
different dataset consisting of information from southern California 
refineries were used in the Monte Carlo analysis, the equivalent leak 
threshold for valves would be 36 g/hr and flanges would be 24 g/hr. 
There are several reasons why the California data is not appropriate 
for the analysis. First we would note that the dataset from the 
California refineries was from refineries where equipment leak 
standards were already in place and leak thresholds would be lower. 
Such a dataset from controlled facilities would not be appropriate for 
the equivalency analysis. As discussed in the proposal preamble and in 
previous responses, a technically defensible equivalency determination 
of any AWP requires modeling of an uncontrolled facility. Second, the 
equipment leak work practice requirements in the California rules, 
which the refineries would be subject to, are not identical to those in 
EPA regulations with Method 21. There were significant differences 
between Method 21 requirements and the requirements for equipment leaks 
in California such that screening results from the two are not 
equivalent. To make a comparison with EPA's Monte Carlo analysis, the 
California data was modified to approximate the requirements of Method 
21. However, this modification is only an approximation and does not 
exactly replicate Method 21 results. Third, we also note that the leak 
threshold of 24 g/hr for flanges was calculated assuming quarterly 
monitoring. However, the EPA requirements for flanges only require 
monitoring about every 2 years. To conduct a proper model for flanges, 
the analysis would need to be run on a 2-year basis. As stated in the 
report (Docket ID No. EPA-HQ-OAR-2003-0199-0032), ``the equivalent AWP 
(leak threshold) increases as the AWP monitoring frequency increases.'' 
This trend implies an equivalent leak threshold based on the existing 
2-year monitoring requirement would be much higher than the 24 g/hr 
number and likely above 60 g/hr.
    Regarding auto-polymerizing compounds, we lack sufficient 
information to equate mass leak rates to concentration levels for them. 
The commenter did not provide any additional information that would 
allow us to do so. Therefore, we are not providing leak thresholds 
specific to auto-polymerizing compounds. We acknowledge the AWP may 
result in more stringent control than the current work practice 
required in equipment leak standards for polymers and resins because 
the model analysis used to develop the AWP was conducted at a leak 
definition of 500 ppm, the most stringent leak definition in Federal 
rules, and using data from natural gas processing plants. If the owner 
or operator considers the AWP not to be appropriate for their facility 
they can continue to use the current work practice to identify leaking 
equipment.
    Comment: One commenter suggested that using the optical gas imaging 
instrument may miss intermittent leaks, which may add significantly to 
fugitive emissions. The commenter added that the AWP needs to account 
for how at certain times potentially large leaks can be disguised as 
small leaks.
    Response: Previous EPA studies have shown that most emissions are 
from equipment with the larger leaks. (Docket ID No. EPA-HQ-OAR-2003-
0199-0044) Prior to leak detection and repair programs, 95 percent of 
the mass emissions were emitted from 5 percent of the equipment, i.e., 
equipment leaking at greater than 10,000 ppm. Additionally, tests 
conducted to ascertain the performance of optical gas imaging cameras 
show that the cameras identified all leaks greater than 60 g/hr (Docket 
ID No. EPA-HQ-OAR-2003-0199-0027, and the response to comments document 
which can be found in Docket EPA-HQ-OAR-2003-0199). These results show 
that the AWP will achieve EPA's goals of detecting leaking equipment 
from which the majority of emissions arise. As a point of comparison, 
we would also note that the current work practice can erroneously 
register low ppm readings below the leak threshold for large emitters, 
i.e., the current work practice can show a broad range of readings for 
the same mass emission. Therefore, the current work practice also would 
not identify all leaking equipment. Also, neither the current work 
practice nor the AWP will identify intermittent leaks because these 
leaks occur when equipment is not monitored.
    The final rule also requires that any leak, no matter how small, 
viewed by the optical gas imaging instrument is considered a leak and 
must be repaired. The performance tests show that the camera can in 
practice ``see'' leaks as low as 10 g/hr, which is below the 60 g/hr 
leak threshold determined to be equivalent to the current work 
practice. As a result, the cameras will identify equipment leaking 
below the 60 g/hr leak threshold and those leaks are required to be 
repaired. Thus, a large leak that could be ``disguised'' as a smaller 
leak under the current work practice would not be misidentified and 
avoid repair.
    Comment: One commenter suggested that a loophole in the AWP allows 
inspectors to bypass proper adjustments for high purity systems 
containing undetectable chemicals. The commenter explained that the 
optical gas imaging instrument can only detect volatile organic 
compounds (VOC) that absorb or emit infrared light. In the synthetic 
organic chemicals manufacturing industry, high purity systems are 
common, and leaks can go undetected if the dominant chemical does not 
register with optical gas imaging technology. The commenter added that 
the proposal contains a loophole that gives the inspector the option of 
using a minimum mass flow rate threshold of either 10 g/hr for pumps or 
6 g/hr for all other equipment instead of adjusting the threshold to 
accommodate the instrument's detection limits. The commenter questioned 
EPA's assumption that all leaks encountered during an inspection 
contain at least 10 percent detectable chemicals. The commenter 
recommended that EPA remove this loophole by eliminating section 
60.18(i)(2)(i)(B) from the rules. The commenter also recommended that 
Method 21 be used for high purity situations where chemicals have not 
been verified as adequately detectable using the optical gas imaging 
technology. The commenter concluded that if EPA chooses to keep the 
loophole, it should address whether the technology fails to detect a 
high number of leaks that are smaller than 6 g/hr.
    Response: After further review of the commenter's concerns, we have 
determined that the commenter is correct regarding the minimum 
detection sensitivity level provided in the tables. The potential 
exists for high

[[Page 78204]]

purity systems to have leaks not identified if the minimum detection 
sensitivity level is used instead of being calculated. Consequently, 
the final rule requires that the detection sensitivity level be 
calculated using the equation in section 60.18(i)(2)(i). The minimum 
detection sensitivity level concept has been removed from the final 
rule. We also note that the optical gas imaging instrument is allowed 
to be used only where it will respond to the equipment leaking. 
Therefore, if the instrument does not respond to high purity streams, 
it cannot be used to detect leaks. The current work practice using 
Method 21 must be used instead.

B. Applicability

    Comment: One commenter requested that EPA clarify that a facility 
is not required to monitor equipment using Method 21 and the AWP.
    Response: The standard is an alternative to the existing work 
practice and may be used in place of the existing work practice where 
feasible and whenever the owner or operator chooses to do so. We are 
not requiring that both be used at the same time. We are requiring that 
each facility choosing to use the AWP monitor the same regulated 
equipment with a 40 CFR part 60, Appendix A-7, Method 21 monitor once 
per year.
    Comment: Several commenters suggested that leaks identified using 
the gas imaging instrument should be verified using traditional Method 
21. Another commenter opposed allowing Method 21 to be used to check 
for leaks found with optical imaging. The commenter suggested that the 
methods could give contradictory results and would serve no purpose. 
The commenter added that because EPA states in the proposal that the 
AWP provides equivalent or better emissions control than Method 21, 
there is no justification for requiring both methods to be applied to 
the same equipment.
    Two commenters also requested that EPA consider allowing facilities 
the option to use Method 21 or the Gas imaging AWP for post repair 
monitoring requirements. The commenters opposed the required approach 
of being limited to the same method for repair monitoring.
    Response: We do not believe that leaks identified in the initial 
screening using the AWP need to be screened using the current work 
practice to verify the leak. By definition in the AWP, a leak is any 
emissions imaged by the optical gas imaging instrument. Requiring the 
facility to use a Method 21 monitor to verify what the optical gas 
imaging instrument has already detected would be an unnecessary 
duplication of effort and resources.
    On the other hand, we have decided that it would be appropriate to 
allow either the current work practice or the AWP to be used for repair 
purposes when the AWP is used for the initial screening. Test 
information has demonstrated that a Method 21 instrument will detect 
leaks that the gas imaging instrument will detect (Docket ID No. EPA-
HQ-OAR-2003-0199-0027, and the response to comments document which can 
be found in Docket EPA-HQ-OAR-2003-0199). Therefore, it is appropriate 
to allow its use when optical gas imaging instruments are used to find 
leaks. If a Method 21 instrument is used for repair monitoring, the 
leak definition in the applicable subpart to which the equipment is 
subject must be used to determine if the repair is successful. However, 
the AWP instrument will not be allowed to verify the repair has been 
made after the Method 21 instrument is used for the once-a-year 
monitoring.
    Comment: Several commenters suggested that an owner or operator 
should be able to selectively apply the proposed AWP to a part of the 
facility, part of a process unit, or even individual equipment. The 
commenters added that selective application of the AWP is appropriate 
because optical gas imaging technology is new and few facilities have 
experience with it, differences within a facility suggest the use of 
Method 21, or the AWP to various parts of the plant, and it would 
encourage the development of the technology.
    Response: We agree with the commenters' suggestion. The AWP may be 
used for the entire facility, a process unit, or a group of equipment. 
The decision is up to the owner or operator how broadly the AWP will be 
used. The owner or operator is required to keep records of where the 
AWP will be used as part of the documentation of the detection 
sensitivity level value.
    Comment: Two commenters suggested that EPA should allow flexible 
use of the AWP by allowing facilities to move from traditional 
monitoring to optical imaging and vice versa without being subject to a 
permitting approval process. The commenters added that a facility 
cannot switch from one technology to another without assuring that 
monitoring frequencies and protocols are fully addressed upon 
switching.
    Response: The flexibility that the commenters are requesting is 
beyond the scope of this action. The issues need to be raised in the 
context of the title V program and the specifics of individual facility 
permits.
    Comment: Several commenters supported using the AWP for monitoring 
closed vent systems. Another commenter suggested that most pressure 
relief vents (PRV) are installed in closed vents routed to control 
devices. Therefore, optical sensing methods cannot evaluate emissions 
inside a closed vent conveyance. The commenter concluded that the AWP 
must allow mixed monitoring methods for closed vents. One commenter 
asserted that the AWP has to be applicable for a 500 ppm leak and any 
change to the standard for monitoring closed vent systems would be 
outside the scope of the AWP. One commenter recommended that the owner 
or operator be given the option of using either Method 21 or an optical 
imaging camera to monitor PRV after the pressure releases.
    One commenter supported the lower leak rates for closed vent 
systems (e.g., 3 g/hr) but noted that the leak rate would be for mass 
flow for a bi-monthly inspection schedule. The commenter added that 
closed vent systems are typically inspected on an annual basis and the 
equivalent leak rate, using the Monte Carlo analysis, for annual 
inspection would be 0.013 g/hr, which is below the range that the 
technology can reliably find leaks. The commenter added that to allow 
use of the optical gas imaging technology to monitor closed vent 
systems, EPA must create a revised inspection schedule which balances 
frequency with limitations of the optical technology. The commenter 
also added that if the optical imaging technology cannot reliably 
measure emissions at low leak rates, Method 21 should be used. The 
commenter stated that supplementing the optical gas imaging technology 
with Method 21 would catch more small leaks characteristic of closed 
vent systems.
    Response: In the preamble to the proposed rule, we took comment on 
whether the AWP was appropriate for closed vent systems but did not 
include language to permit such use. We have evaluated the commenters' 
concerns and have decided that the AWP is not appropriate for 
monitoring closed vent systems, leakless equipment, or equipment 
designated as non-leaking. While the AWP will identify leaks with 
larger mass emission rates, tests conducted with both the AWP and the 
current work practice indicate the AWP, at this time, does not identify 
very small leaks and may not be able to identify if non-leaking/
leakless equipment are truly nonleaking because the detection 
sensitivity of the optical gas imaging instrument is not sufficient. 
Therefore, in the final rule, as in the proposed rule,

[[Page 78205]]

we have decided not to allow the AWP to be used for closed vent 
systems, leakless equipment, or equipment designated as non-leaking.
    Comment: Several commenters supported using the optical imaging 
technology to find, review, and fix non-regulated and previously non-
detectable leaks without additional regulatory burden and fear of 
reprisal from enforcement actions. One commenter suggested that the 
camera be used as a form of enhanced visual inspection to quickly 
identify whether a group of equipment has passed or failed and that 
result be stored in a database. Then, the camera and recorded video 
could be used to target only the leaking equipment. Another commenter 
supported using the optical imaging device as a screening tool for 
leaks so that annual Method 21 leak checks could be targeted to 
equipment suspected of leaking.
    Other commenters asserted that the AWP should require that all 
leaks detected with optical gas imaging be corrected according to the 
existing leak correction time requirements, regardless of whether or 
not the equipment would have been required to be monitored using Method 
21. One commenter added that if the operator monitors leaks outside of 
the EPA requirement, the AWP should require the company maintain 
records. The commenter stated this would prevent operators from 
repairing leaks just prior to an official inspection and reporting 
artificially low levels. One commenter requested that the AWP also 
apply to inaccessible and unsafe to monitor equipment. The commenter 
also suggested that expanding the inventory would reduce the number of 
large leakers, and reduce the cost to the plant by enabling the plant 
to repair large leakers rather than an inventory of equipment which 
they are mandated to monitor and repair.
    Response: The AWP requirements are intended to provide an 
alternative to the current work practices using Method 21. Requirements 
in the existing subpart that are specific to Method 21 do not apply to 
the AWP. All other requirements in the applicable subpart that are not 
specifically addressed in the AWP apply, such as schedule for repairs, 
designation of difficult to monitor equipment and unsafe to monitor 
equipment. Therefore, the schedule for repairing leaks is the same for 
both work practices. The final rule changes were not intended to expand 
the applicability of the existing rules. The Agency has promulgated the 
AWP to facilitate the use of emerging technology as quickly as 
appropriate. Once the regulated community and EPA have more experience 
with the AWP, we may consider expanding the applicability of the 
existing rules.
    Comment: Several commenters provided input on definitions for 
``difficult to access'' or ``unsafe to access'' or ``unsafe to repair'' 
or ``difficult to repair.'' Several commenters requested EPA include 
the concept of ``difficult to access'' in the AWP because access is 
still required to make repairs and in some cases this may not be 
possible. One commenter suggested replacing the term ``difficult to 
access'' with ``unsafe to access.'' One commenter also suggested adding 
a definition for ``unsafe to access'' equipment because the AWP would 
allow more frequent monitoring of these equipment due to the nature of 
the technology, but does not address the repair requirements for such 
equipment. One commenter suggested for equipment designated as 
``difficult to access'' repair be required as soon as practical but no 
later than 90 days. Equipment identified as ``unsafe to access'' should 
be required to be repaired when it is safe to do so. One commenter 
requested EPA to describe how facilities switching to the AWP would 
manage their ``difficult to monitor'' lists.
    Response: The interpretations of the terms ``difficult to 
monitor,'' ``difficult to repair,'' or ``unsafe to monitor'' are driven 
by work practice in use and therefore are not addressed in this 
section. We expect the population of equipment so designated under the 
existing work practice will change to accommodate the differing 
capabilities of the AWP instrument. Therefore, we are not addressing 
``difficult to monitor,'' ``difficult to repair'' or ``unsafe to 
monitor.''

C. Rule Location

    Comment: Several commenters supported locating the AWP in the 
General Provisions. However, many of the commenters requested that the 
AWP be located in the General Provisions to each applicable Part rather 
than only in Part 60. Other commenters preferred that Method 21 be 
revised to include the AWP rather than include language in the General 
Provisions.
    Several commenters supported including the amendatory language in 
each applicable subpart and opposed having it in only one Part. The 
commenters suggested that the proposed method would result in numerous 
inconsistencies with the subparts and would be confusing.
    Two commenters suggested that the proposed language in the 40 CFR 
part 60 General Provisions was legally insufficient. One of the 
commenters asserted that EPA must incorporate the AWP into all subparts 
where it will be readily apparent to the affected industry groups, 
regulators, and the public.
    Response: We believe there is no simple way to incorporate the AWP 
into the numerous subparts. The General Provisions appear to be the 
most efficient way to accommodate the desired amendments, so in 
response to the comments received, we have decided to incorporate the 
AWP into the General Provisions of parts 60, 63, and 65. The AWP is 
also applicable to those subparts in part 61 that reference the General 
Provisions in part 60. Additionally, where specific subparts require 
modification (such as tables in Part 63 subparts that reference General 
Provisions sections), we have made the appropriate revisions. The 
suggestion to incorporate the AWP into Method 21 is both inappropriate 
and awkward because Method 21 contains a test method only and should 
not contain recordkeeping, reporting, and monitoring requirements.

D. Alternative Work Practice Procedures and Equipment Specifications

    Comment: One commenter requested that use of the optical imaging 
technology be complemented with Method 21 as necessary to compensate 
for shortcomings in the camera design. The commenter noted the 
differences between active and passive cameras and their 
vulnerabilities, as well as interferences from carbon dioxide and 
steam/water, use outdoors, and the color of the background. The 
commenter recommended that the AWP should fully address the limitations 
of each technology and require that inspectors identify and make 
records of equipment types that are poor candidates for either kind of 
optical gas imaging technology.
    Response: The AWP can only be used to detect leaks when the gas 
imaging instrument is shown to work (i.e., streams that contain 
compounds that can be detected by the gas imaging instrument). 
Therefore, if a specific type of gas imaging device does not work on a 
stream, operators will continue to use the Method 21-based work 
practice for these equipment. Although this commenter did not provide 
any data supporting the need to augment the AWP with the Method 21 
instrument, as explained earlier, we are requiring annual monitoring 
with the Method 21 instrument. (See section III.A of this preamble for 
a discussion of this requirement.)
    Comment: One commenter requested EPA to explain how a facility 
would identify which analytical methods

[[Page 78206]]

should be used for which compounds, especially when potentially 
incompatible compounds may be included in a mixture within a group of 
emission equipment. The commenter added that it would be unfair to 
penalize a facility by prohibiting the use of the AWP because the AWP 
cannot detect all VOC in a specific process unit.
    Another commenter requested clarification that the requirement in 
40 CFR 60.18(i)(1) that imaging the compounds in the streams does not 
mean or imply that every compound in the stream must be detected.
    Response: The AWP does not require that every compound in the 
stream be detected. Only one compound needs to be able to be viewed. 
However, the 60 g/hr leak rate threshold must be adjusted, i.e., scaled 
down, to account for compounds that are not seen. The language in the 
final rule was modified to clarify this point.
    Comment: One commenter requested that petroleum refineries be 
exempt from the stream speciation and variability of process stream 
requirements because petroleum refineries were used in the development 
of the standard and because the mixed hydrocarbons contained in the 
streams have been demonstrated to meet all the monitoring criteria. The 
commenter specifically opposed requiring an engineering analysis. The 
commenter suggested adding language that allows the determination to be 
based on the process knowledge that an image from the camera is not a 
leak if that image is determined to be steam or other unregulated 
material.
    Response: In the proposed rule, we provided a definition for 
``engineering analysis'' that described the requirements for 
determining the piece of equipment in contact with the lowest mass 
fraction of chemicals that are detectable. In the final rule, we have 
decided to put the requirements for the analysis directly in the rule 
rather than have a separate definition.
    In the final rule, we are requiring owners or operators to 
determine the piece of equipment in contact with the lowest mass 
fraction of chemicals that are detectable. It is up to the owner or 
operator to provide sufficient information to meet this requirement. 
This information may include process knowledge, previous studies, or 
analyses conducted for the AWP. The documentation of the analysis is 
required to be kept as a record for as long as the AWP is used and must 
be updated to incorporate any changes that may affect the analysis. The 
Administrator may request to review the documentation. Because this 
requirement is now in the rule, it is not necessary to include it in 
the term ``engineering analysis.'' Therefore, in the final rule, the 
term ``engineering analysis'' has been removed.
    We also disagree that petroleum refineries should be exempted from 
the stream speciation and variability of process stream requirements. 
The commenter's reasoning is not a sufficient justification for such an 
exemption because, although some refinery streams were used to develop 
the method, there are a wide variety of refineries with varying streams 
and without site specific analysis we have no assurance that the 
required leak rate can be imaged.

E. Recordkeeping and Reporting

    Comment: One commenter requested the owner or operator of an 
affected source be required to submit notice to the Administrator that 
they have elected to use the AWP and state the duration the AWP will be 
used.
    Response: For the final rule, we have required a memorandum to the 
owner's or operator's file identifying the equipment, process units, or 
facilities that are to be included in the AWP to document that a 
facility has chosen to comply with the AWP. This documentation must be 
kept for as long as the AWP is used and the Administrator may request 
to review it. It is not necessary to submit notification to the 
Administrator that the AWP will be used. Owners or operators are still 
required to meet the requirements in the subpart except where they are 
superseded by the AWP. Therefore, the same reports and records kept for 
the current work practice will be required for the AWP.
    Comment: Several commenters requested that EPA allow owners/
operators the option of keeping video records to provide flexibility; 
others opposed requiring keeping video records. Several commenters 
added that recordkeeping for the AWP should not be more burdensome than 
the applicable subparts. The commenters noted that the AWP will add 
significant burden to facilities and regulators. One commenter stated 
that facilities will incur burden from additional storage of electronic 
files. The commenter provided estimates of the amount of electronic 
storage space that would be necessary, indicating as much as 50 
gigabytes would need to be stored per inspection. The commenter added 
that EPA should consider the time needed to transfer large files 
between field data collection devices and the plant's computer in the 
time necessary to use the AWP. One commenter expressed concern about 
maintaining videos of every leak survey, especially if the AWP requires 
that each piece of equipment be imaged separately. The commenter noted 
that the battery life of the camera and recorder are limited, storage 
of the videos will be burdensome, and data retrieval will require 
searching the videos and will be cumbersome.
    Other commenters suggested that video records of the daily 
instrument check should be required. One commenter recommended EPA 
maintain the documentation requirements for monitoring of all 
equipment. The commenter asserted that video documentation is an 
important enforcement tool and is a safeguard against fraud. The 
commenter disputed industry assertions of the cost of keeping video 
records and suggested that computer storage represents only a fraction 
of the costs of the LDAR program.
    Response: The final rule requires that if the owner or operator 
chooses to use the AWP, video records of all viewed regulated equipment 
and video records of the daily instrument check must be kept for 5 
years. We recognize that data files for video records may be large. 
However, to ensure that the AWP is being complied with, we believe it 
is necessary to require video records of each piece of equipment that 
is viewed. We would also like to reiterate that the standard is an AWP. 
If owners or operators believe that the video recordkeeping 
requirements are too burdensome, they may continue to comply with the 
existing requirements as written. We also note that the AWP is not 
superceding the recordkeeping and reporting requirements that are in 
the existing equipment leak standards. The owner or operator must still 
keep those records. However, in the final rule a video record can be 
used to meet the recordkeeping requirements of the applicable subparts 
if each piece of regulated equipment selected for this work practice 
can be identified in the video record.

F. Other Comments

    Comment: One commenter asked EPA to clarify whether a requirement 
that the instrument be intrinsically safe will be incorporated into the 
AWP. One commenter suggested that a significant burden will be incurred 
by requiring instruments that are intrinsically safe. The commenter 
added that EPA is requiring that personnel take into hazardous areas 
data storage devices that are not intended for that purpose.
    Response: We are not requiring that gas imaging instruments be 
intrinsically safe. It is incumbent upon the

[[Page 78207]]

manufacturer to develop instruments that are designed to meet the 
requirements of the chemical facility or refinery. Facilities may or 
may not require equipment be intrinsically safe. The owner or operator 
is not being required to use the AWP. If such instruments are not 
available, and the operator requires intrinsically safe instruments, 
then the owner or operator does not have to choose to use the AWP.
    Comment: Several commenters requested that EPA provide guidance on 
how a facility would calculate emission rates for emission inventories 
if the AWP is in use. One commenter specifically asked how a facility 
would manage default zero equipment for emission estimation purposes. 
Several commenters added that if guidance is not provided, EPA should 
revise the AWP to include quantification procedures consistent with 
EPA's preferred methodology. One commenter asserted that optical gas 
imaging is limited by its inability to quantify leak concentration, 
which are converted to emission rates using the correlation equations. 
The commenter added that facilities must be required to use Method 21 
or an equivalent emissions estimation technique to quantify leaks 
detected with optical gas imaging. Another commenter suggested that gas 
imaging technology has the ability to quantify emissions; therefore, 
quantification should be required in the AWP.
    Response: The Agency recognizes the need for new approaches to 
estimate emissions from facilities that implement the AWP. We will work 
with stakeholders to develop the necessary tools for quantification. In 
the final rule, we are also requiring each facility complying with the 
AWP also monitor the same regulated equipment with a Method 21 monitor 
once per year. The data gathered from this requirement will help us 
address the issue of emissions quantification.
    Comment: One commenter considered that public notification of the 
rulemaking was incomplete and inadequate because the title and summary 
of the proposed rule only addressed 40 CFR part 60 but the proposal 
would amend 40 CFR parts 61, 63, and 65 as well. The commenter added 
that before EPA promulgates the AWP, it needs to propose the AWP for 
parts 61, 63, and 65.
    Response: We believe that sufficient notification was provided that 
the AWP would apply to subparts other than in 40 CFR part 60. The 
proposed rule specifies in 40 CFR 60.18(a)(2) that the AWP is available 
to all subparts in 40 CFR parts 60, 61, 63, and 65 that require 
monitoring of equipment with a 40 CFR part 60, Appendix A-7, Method 21 
monitor. The rule clearly states that the AWP applies to 40 CFR parts 
60, 61, 63, and 65. Similarly, the preamble to the proposed rule states 
that it applies to 40 CFR parts 60, 61, 63, and 65.

IV. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    This action is not a ``significant regulatory action'' under the 
terms of Executive Order 12866 (58 FR 51735, October 4, 1993) and is, 
therefore, not subject to review under the Executive Order.

B. Paperwork Reduction Act

    The information collection requirements in this rule have been 
submitted for approval to the Office of Management and Budget (OMB) 
under the Paperwork Reduction Act, 44 U.S.C. 3501, et seq. The 
information collection requirements are not enforceable until OMB 
approves them.
    This final rule provides plant operators with an alternative method 
for identifying equipment leaks, but does not change the basic 
recordkeeping and reporting requirements in the various subparts of 40 
CFR parts 60, 61, 63, and 65. However, EPA anticipates that this final 
rule will change the burden estimates developed and approved for the 
existing national emission standards by reducing the labor hours 
necessary to identify equipment leaks.
    An ICR document (EPA ICR No. 2210.02) was prepared for this final 
rule to estimate the costs associated with reading and understanding 
the alternatives, purchasing an optical imaging instrument, and initial 
training of plant personnel. The ICR has been approved by OMB under the 
Paperwork Reduction Act, 44 U.S.C. 3501, et seq. The annual public 
burden for this collection of information (averaged over the first 3 
years after the effective date of the final rule) is estimated to total 
3,027 labor hours per year and a total annual cost of $2,260,189. EPA 
has established a public docket for this action (Docket EPA-HQ-OAR-
2003-0199) which can be found at https://www.regulations.gov. The ICR 
for this final rule is included in the public docket. Burden is defined 
at 5 CFR 1320.3(b).
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9. In addition, EPA is 
amending 40 CFR part 9 in the Federal Register to display the OMB 
control number for the approved information collection requirements 
contained in this final rule.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of the final rule on small 
entities, small entity is defined as follows: (1) A small business 
whose parent company has fewer than 100 to 1,500 employees, or a 
maximum of $5 million to $18.5 million in revenues, depending on the 
size definition for the affected North American Industry Classification 
System (NAICS) code; (2) a small governmental jurisdiction that is a 
government of a city, county, town, school district or special district 
with a population of less than 50,000; and (3) a small organization 
that is any not-for-profit enterprise which is independently owned and 
operated and is not dominant in its field. It should be noted that the 
small business definition applied to each industry by NAICS code is 
that listed in the Small Business Administration size standards (13 CFR 
part 121).
    After considering the economic impact of this final rule on small 
entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. In 
determining whether a rule has a significant economic impact on a 
substantial number of small entities, the impact of concern is any 
significant adverse economic impact on small entities, since the 
primary purpose of the regulatory flexibility analysis is to identify 
and address regulatory alternatives ``which minimize any significant 
economic impact of the rule on small entities.'' 5 U.S.C. 603 and 604. 
Thus, an agency may certify that a rule will not have a significant 
economic impact on a substantial number of small entities if the rule 
relieves regulatory burden, or otherwise has a positive economic effect 
on all of the small entities subject to the rule.
    We have concluded that this final rule imposes no additional burden 
on

[[Page 78208]]

facilities impacted by existing EPA regulations. This final rule allows 
plant operators to voluntarily use an AWP. In fact, EPA expects the AWP 
will relieve regulatory burden for all affected entities by reducing 
the labor hours necessary to identify equipment leaks.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act (UMRA) of 1995, Public 
Law 104-4, establishes requirements for Federal Agencies to assess the 
effects of their regulatory actions on State, local, and Tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures by State, local, and tribal governments, in 
the aggregate, or by the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective, or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective, or least burdensome alternative if EPA 
publishes with the final rule an explanation why that alternative was 
not adopted.
    Before EPA establishes any regulatory requirements that may 
significantly or uniquely affect small governments, including Tribal 
governments, EPA must have developed, under section 203 of the UMRA, a 
small government agency plan. The plan must provide for notifying 
potentially affected small governments, enabling officials of affected 
small governments to have meaningful and timely input in the 
development of EPA's regulatory proposals with significant Federal 
intergovernmental mandates, and in