Chapter 10
Monitoring, Recordkeeping, and Reporting and Other Issues
Contents
10.1	Monitoring and Compliance	2
10.2	Recordkeeping	13
10.3	Reporting	15
10.4	Regulatory Text	17
10.4.1 Subpart TTTT or Subpart Da and KKKK	23
10.4.2 Definitions	26
10.5	Request for Extension	33
10.6	Incorporation by Reference	35
10.7	Net or Gross MW Output	39



Monitoring and Compliance
Multiple commenters (0161, 0171, 0212, 0213, 0257) provided comments on the proposed monitoring requirements. Commenter 0213 noted that EPA currently requires covered units that burn solid fuel to install CEMS, but permits sources that burn exclusively gaseous or liquid fuel to estimate their emissions based on fuel consumption data. The commenter suggested the Agency should instead require all sources to install CEMS, which the commenter said are inexpensive, readily available, and considerably more accurate than input-based emission estimates. Moreover, regardless of its emissions monitoring system or method, each source must be required to include emissions during ramping and low-load periods in its data collection. These periods normally include higher emissions, and there is no legal or policy rationale from excluding them from a compliance determination. 
Commenter 0171 stated that EPA should not require the use of stack flow monitors and CO2 analyzers, and should allow for additional monitoring options, including fuel flow meters. For example, NSPS proposed section 60.5525(c)(1) cross references 40 CFR 75.10(a)(3)(i), which would require the use of a stack flow monitor and would exclude other options, including fuel flow meters, that are provided within other provisions of 40 CFR 75.10(a)(3). The commenter said EPA should update this and any other references to make clear that all of the monitoring options provided within 40 CFR 75.10(a)(3) are available. There is no rational basis for EPA to limit monitoring options to stack flow monitors to the exclusion of fuel flow meters. Fuel flow metering under 40 CFR 75 is widely utilized and provides high quality CO2 emissions data. There is no rational basis not to allow the use of proven technology to calculate CO2 mass emissions as provided in 40 CFR 75, including fuel flow meters.
Commenter 0212 supported fuel consumption monitoring as the preferred method of measurement for gas turbines, with CEMs being a widely-available alternative. Commenter 0257 requested that EPA allow the option to use an O2 analyzer and Equation G-4 of Appendix G to calculate CO2 emissions for NGCC units.
Commenter 0161 noted that EPA is proposing that measurements of electricity output be measured using 0.2 class electricity metering instrumentation and calibration procedures. The commenter suggested that EPA modify the proposal such that measurements of electricity output can be measured using whatever metering instrumentation is used for billing purposes
Commenter 0215 does not understand why EPA has specifically required use of a CO2 CEMS (and not allowed use of an O2 CEMS to obtain CO2) at an EGU that does not use carbon separation. The commenter stated that both existing NSPS applicable to modified and reconstructed EGUs - Subparts Da and KKKK - allow use of either a CO2 concentration monitor or an O2 concentration monitor as the diluent monitor to calculate emissions in lbs per MMBtu, and Part 75 explicitly allows use of an O2 concentration monitor to measure CO2 concentration to obtain CO2 mass emissions. The commenter stated that there is no valid reason not to allow both types of monitoring systems under this rule for EGUs without carbon capture. 
  The final rule (Subpart TTTT) allows the use of data from a certified O2 monitor to calculate hourly CO2 concentrations, provided that the affected EGU does not use carbon separation. The final rule requires the use of CEMS for coal-fired EGUs and IGCC units and allows all other affected units to use CEMS. However, units that combust only liquid and/or gaseous fuel may opt to use Equation G-4 in Appendix G of Part 75 to quantify the CO2 mass emission rate.  Additionally, the EPA disagrees with the commenters that only a billing meter should be used for monitoring electricity output.  The EPA is requiring the ANSI C12.20 class metering in the final rule to make sure all output measurements are consistent and comparable.
Commenters 0215 and 0257 submitted a comment on the proposed requirement for "EGU owners or operators to prepare and submit a monitoring plan that includes both electronic and hard copy components, in accordance with 40 CFR 75.53(g) and (h)."1 The commenter requested that EPA make clear that that the submission of a plan by a Designated Representative (DR) meeting part 75 also constitutes compliance with the NSPS requirements. Since monitoring plans under part 75 must be certified by a DR meeting the definition and requirements in Part 72, and information reported under an NSPS must be submitted by the facility owner or operator, which may be someone other than the DR, EPA must make allowances for the different certifications in these reporting systems. 
Commenter 0215 did not oppose a requirement in this rule for preparation of a monitoring plan for systems to measure and record CO2 mass emissions, or submission of that plan to ECMPS and the EPA regional office. The commenter stated, however, that the proposed rule language is overly broad in that the monitoring plan requirements in section 75.53(g) and (h) are not limited to monitoring systems for CO2 mass emissions. 
The EPA has clarified in the final rule that the submittals by the DR are required for compliance, additionally, the EPA has finalized clarifying language with respect to the monitoring plan submittals do not need to be in duplicate if the EGU has already submitted one.
Commenter 0215 stated that EPA says that it is proposing to require that all "monitoring systems" used to determine CO2 mass emissions be certified within the timeframe in 40 C.F.R. section 75.4(b). The commenter stated that modified and reconstructed EGUs presumably already would have been generating electricity for sale and already would have had certified CO2 monitoring systems under Part 75. The commenter stated that if EPA intends that the deadline apply based on commencement of commercial operation following the modification or reconstruction, EPA should say that. The commenter stated that EPA also should make clear that new certification or diagnostic tests are not required for previously certified CO2 mass emissions monitoring systems except as provided in section 75.20(b).
If a unit has a certified monitor in place, monitoring has to begin immediately.  These requirements are consistent with the reference to part 75 in the final rulemaking.
Multiple commenters (0171, 0192, 0213, 0257) provided comments on the proposed CEMS certification and QA procedures. The proposed rule would require "all monitoring systems used to determine the CO2 mass emission rates...to be certified according to section 75.20 and section 6 of part 75, Appendix A within the 180-day window of time allotted under section 75.4(b), and...meet the applicable on-going quality assurance procedures in Appendices B and D to part 75." Commenter 0192 argued that EPA must include provisions to address facilities that cannot meet CEMS certification requirements. The commenter was concerned that EPA's proposed requirements for monitoring and compliance determination procedures did not account for challenges that certain industry members have faced regarding CEMS for GHG emissions. While the majority of facilities that have installed CEMS systems have been able to certify them successfully, several have been unable to comply with the 20% variability range for flow RATA that EPA currently requires for CEMS certification. The commenter urged EPA to include an additional provision in the Monitoring and Compliance Determination Procedures section that would apply in lieu of the certification requirements in the event that, due to unforeseen circumstances, a source is unable to obtain CEMS certification. For example, EPA could permit such sources to comply with 40 CFR part 75 Appendix G, which includes a procedure for estimating CO2 emissions from combustion. 
Commenter 0213 stated that EPA should grant a 90-day rather than 180-day window in which to certify the performance of its CEMS. The shorter time period would ensure compliance sooner, would be consistent with EPA's initial timetable for certification of CO2 CEMS,3 and would reflect the time reasonably necessary to conduct the required procedures.
Commenter 0257 requested that EPA provide an explicit exemption from section 60.13(a) and Appendices B and F QA/QC requirements for sources using CEMS when following the QA standards of part 75 Appendices A and B.
Commenter 0171 requested that EPA not alter the daily calibration and relative accuracy specifications currently provided in 40 CFR part 75. The justification for incorporating the monitoring methodologies of 40 CFR part 75, but altering daily calibration and relative accuracy specifications is unclear. Moreover, such a change would result in unnecessary duplication; rendering what should be valid data for both the purposes of 40 CFR part 75 and the GHG NSPS, valid for one and not the other. Certain monitoring methods also have physical limitations that would make achieving these unnecessary standards likely impossible.
Commenter 0171 understood EPA's desire to solicit comment to ensure that monitoring standards are kept current over time, but argued that EPA offered no rationale or evidence to support the need to increase the stringency of existing CEMS regulations now in use under either 40 CFR part 60 or 40 CFR part 75. EPA must take into account the fact that potential changes to these standards will place significant additional burdens on regulated entities without providing a commensurate additional benefits required by the President's recent executive order on Improving Regulation and Regulatory Review. As mandated by the executive order, EPA must ensure that it tailors its regulations to utilize "the least burdensome tools for achieving regulatory ends" and "improve the actual result of the regulatory requirements," and regulations must be "based on the best available science."
Commenter 0215 supported the proposed reliance on Part 75 QA/QC. The commenter stated that to ensure that EGUs are not subject to duplicative and inconsistent QA/QC requirements, EPA must exempt EGUs using CEMS from the requirement in section 60.13(a) to comply with performance specifications in Part 60, Appendix B and ongoing QA/QC under Part 60, Appendix F. The commenter stated that Part 60 Appendices B and F contain performance specifications and testing requirements that are duplicate and are inconsistent with the Part 75 QA/QC. The commenter stated that if EPA wants CO2 mass emissions under this NSPS to be quality-assured according to Part 75, EPA must identify the QA/QC requirements in section 60.13(a) as not applicable in Table 1 to Subpart TTTT, and should explicitly state in the applicable rules that those requirements do not apply. The commenter stated that if there are specific elements of Part 60, Appendices B and F that EPA believes should apply in lieu of Part 75, EPA should identify them and solicit comment on that alternative approach. The commenter stated that it did not understand EPA's proposed reference to compliance with Part 75, Appendix D for units using CEMS. The commenter stated that EPA should replace the reference to Appendices B and D with "Appendices A and B." 
These comments have been responded to elsewhere in this final rule.
Commenter 0215 does not oppose requiring solid fuel-fired EGUs that employ carbon separation technology to use a CO2 CEMS and a stack flow monitoring system, or allowing other EGUs to use such systems. The commenter stated that an O2 CEMS cannot be used to obtain accurate CO2 measurement at the stack of an EGU that employs carbon separation because that calculation to convert O2 measured at the stack to CO2 relies on the use of F-factors and any equation that uses an F-factor will not provide accurate measurements downstream of any device that removes CO2 from the gas stream.
The EPA thanks the commenters for their comment.
Commenter 0215 stated that the proposed language requiring EGUs that measure CO2 concentration on a dry basis to "install, certify, operate, maintain, and calibrate a continuous moisture monitoring system" under section 75.11(b), could be interpreted as eliminating the option in section 75.11(b)(1) to use appropriate default moisture values rather than installing and calibrating a monitoring device. The commenter stated that the Part 75 default moisture values for coal and wood were derived from EPA's evaluation of data in a 1999 rulemaking in which the Agency determined that they were sufficiently conservative to ensure no under-reporting. The commenter stated that if EPA has a reason for eliminating the O2 monitoring and moisture default value options for either modified or reconstructed coal-fired EGUs or modified and reconstructed liquid and gas-fired EGUs, it must issue a rulemaking proposal identifying that reason. The commenter stated that because modified and reconstructed EGUs still will need to comply with the ARP, eliminating these options in the NSPS effectively eliminates them for NSPS units in Part 75.
 The final rule allows the fuel-specific moisture defaults in §75.11(b) to be used in lieu of continuously monitoring the stack gas moisture content.
Commenter 0213 noted that the proposal requires sources to supply valid data for at least 95 percent of their operating hours. The commenter said the Agency must specify that a failure to meet the 95 percent valid data requirement constitutes a violation of the rule's monitoring requirements and should assess sufficiently stringent penalties against sources that fall short of this threshold. For suggestions on different penalty structures, the commenter referred to their Comments on the New Source Standard.
Commenter 0215 requested clarification of what constitutes "valid data", and requested that should be consistent with Part 75.  Commenter 0215 stated that with respect to the proposed 95 percent data availability requirement, although UARG believes that most CO2 monitoring systems would be able to meet that criterion that may not be the case if the Part 75 data validation provisions are used. The commenter stated that it does not believe it would be appropriate to invalidate data in a rule with a 95 percent data availability requirement without some alternative validation procedure. The commenter stated that EPA should either (1) make clear that data are not invalidated under this rule unless a performance test is failed (i.e., unless the monitoring system is "out-of-control"), and take into account in the ICR the developing and maintaining separate databases for the two rules, or (2) include a procedure to validate data that does not otherwise meet Part 75.
 The EPA is finalizing the requirement of the use of valid data in all calculations for compliance with an applicable emission standard and is retaining the requirement of 95% data availability.  Additionally the EPA is not allowing in this final rule for the use of any substitute data as the EPA does not believe it is appropriate to use for complying with the rate-based emission standards put in place by the final rule. The EPA has added language in the final rule to make these requirements clear.
Commenter 0215 stated that EPA proposes that only operating hours in which "valid data" are collected by the monitoring systems for all required parameters (including data recorded during startup, shutdown, and malfunction) be used for compliance purposes. The commenter stated that in the preamble, EPA appears to equate valid data with data from a monitoring system that is not "out of control." The commenter stated that EPA proposes to require EGUs to obtain valid hourly values for a minimum of 95 percent of the operating hours in the applicable compliance period and also proposes to prohibit use of missing data substitution procedures. The commenter agrees that EGUs should not use Part 75 missing data procedures in calculating compliance, and states that missing data procedures can significantly overstate emissions and interfere with compliance demonstrations.  The commenter agrees that backup monitoring systems under section 75.10(e) and section 75.20(d) should be allowed, but not required. The commenter stated that EPA already has adopted a definition of "out-of-control" under Subpart Da, and proposed a definition of "out-of-control" under Subpart KKKK, that are not consistent with the Part 75 definition. The commenter stated that in 2012, EPA without notice or opportunity for comment promulgated a definition of "out-of-control" in Subpart Da under which the "out-of-control" period begins and ends with the corresponding quadrant" of an hour instead of the corresponding clock hour. The commenter stated that because EPA did not propose the definition, UARG petitioned for reconsideration of it. The commenter stated that to the extent EPA intends to require validation of hourly data based on 15 minute periods, the purpose and practical implications of that requirement are not clear. With respect to daily tests, the commenter believes that it is very unlikely that the definition would result in any greater level of data availability than the Part 75 definition. The commenter stated that facilities subject to both Subpart Da and Part 75 would need to have systems in place to track the different data validation rules and determine how the data under each rule are affected. The commenter stated that if EPA finalizes the proposed definition in Subpart KKKK, the same would be true for that rule. The commenter stated that in the event that EPA implements this NSPS through revisions to Subparts Da and KKKK (rather than promulgate a new Subpart TTTT), EPA should take this opportunity to revise the definition of "out-of-control" in Subpart Da to be consistent with Part 75, and adopt a consistent definition in Subpart KKKK. The commenter stated that if EPA promulgates a new Subpart TTTT, EPA should simply defer to the Part 75 definition, rather than promulgate a new one. The commenter stated that even if EPA resolves the conflicting definitions of "out-of-control," the rule will require clarification with respect to its relationship to Part 75. The commenter stated that Part 75 includes additional provisions under which data that are not otherwise "out-of-control" may be invalid if certain types of changes are made to the monitoring system, or if a quality-assurance test is not conducted on-time. The commenter stated that EPA must be clear whether such data would be considered valid under this NSPS and, if they would, must take into account the fact that facilities would need to keep a database that is separate from Part 75 reported data in order to implement this proposed rule.
 The final rule includes a definition of "valid data", which defers to the data validation criteria in Part 75. Section §60.5540(a)(1) also defines a "valid  operating hour" as one in which: (1) "valid data" are obtained for all parameters that are used to calculate the CO2 mass emission rate (tons/hr); and (2) the corresponding gross output value is available. Part 75 substitute data values are not considered to be valid data. Also, for the purposes of Subpart TTTT, an operating hour in which there is a full-scale exceedance for a parameter that is used to calculate the CO2 mass emission rate (tons/hr) is not considered to be a valid operating hour.
The final rule retains the 95 percent data availability requirement and ties it to the definition of "valid operating hours". For units that operate frequently, at least 95 percent of the operating hours in each compliance period must be "valid operating hours".
The rule includes a provision allowing the use of backup monitors, in accordance with §§75.10(e) and 75.20(d).  
Commenter 0215 stated that if valid data are collected during a process or emission control equipment malfunction, EPA proposes that the data be included in compliance calculations, regardless of whether such data were considered when setting the standard and the commenter objects to this requirement. The commenter stated that EPA must demonstrate that a proposed NSPS is achievable with adequately demonstrated control technology. The commenter stated that in some cases the collection of data necessary to establish a standard of performance that accounts for malfunctions may not be technologically or economically practicable and that would be the case with respect to the Proposed Standards for modified and reconstructed fossil-fuel-fired utility boilers. The commenter stated that to the extent EPA reviewed any data that included some periods of malfunction, it apparently was not possible for EPA to determine the impact of those malfunctions on any individual unit's compliance. The commenter stated that EPA has not established that any of its Proposed Standards are achievable even under normal operating conditions, let alone achievable in the event of a malfunction. The commenter stated that while EPA suggests that its proposal is consistent with the recent decision by the U.S. Court of Appeals for the D.C. Circuit in Natural Res. Def. Council v. EPA that decision did not address EPA's obligation to consider malfunctions under section 111, but only established that the rule EPA had adopted was not lawful under section 112.
EPA disagrees with this comment and has concluded that there are important differences in using malfunction data for setting a standard as opposed to compliance calculations. For setting standards, the EPA interprets CAA section 111 as not requiring emissions that occur during periods of malfunction to be factored into development of CAA section 111 standards.  Nothing in CAA section 111 or in case law requires that the EPA consider malfunctions when determining what  standards of performance reflect the degree of emission limitation achievable through ``the application of the best system of emission reduction'' that the EPA determines is adequately demonstrated.  While the EPA accounts for variability in setting emissions standards, nothing in section 111 requires the Agency to consider malfunctions as part of that analysis. A malfunction should not be treated in the same manner as the type of variation in performance that occurs during routine operations of a source.  A malfunction is a failure of the source to perform in a "normal or usual manner" and no statutory language compels EPA to consider such events in setting section 111 standards of performance. By contrast, EPA has concluded that emissions during malfunctions should be included in compliance calculations.  EPA acknowledges that 40 CFR section 60.8 provides that emissions during malfunctions shall not be considered a violation of the applicable emission limit, unless otherwise specified in the applicable standard.  As explained in the proposed action, however, EPA interprets the reasoning of the court in the D.C. Circuit's decision in Sierra Club v. EPA to apply to NSPS under section 111.  Thus, EPA has concluded that excluding malfunction emissions from compliance calculations and treating such emissions as exempt is impermissible in light of the requirements of the CAA and the reasoning of the court in Sierra Club v. EPA concerning the statutory requirement for continuously applicable emission limitations.  
Commenter 0213 noted that the modified/reconstructed proposal currently provides for monthly compliance determinations. The commenter urged the Agency to conduct daily compliance determinations instead, which would better effectuate the CAA's goal of deterring and remedying all emission exceedances and would ensure that sources come into compliance more swiftly with their emission limits. 
 The EPA disagrees with the commenter 9514 and compliance is to be assessed solely on the basis of whether the average CO2 emission rate over the specified 12-operating month averaging period meets the standard. For more discussion on the 12-operating month compliance period please see section IV.C. of the preamble.
Commenter 0213 stated that EPA must adopt measures to guarantee near-term compliance with the rule. Consistent with past practice, the Agency should require each affected unit to perform an initial compliance demonstration using prescribed reference test methods within six months of modifying.
The final rule retains the exemption from performing initial performance stack tests. Because compliance with the emission standards is based on a 12-operating month average, it is not reasonable to hold the sources to these standards based on the results of a stack test. Over a long period of time, the CO2 mission rate will fluctuate and may exceed the numerical value of the standard at times. If a 3-hour emission test is performed during one of these incidents, it may appear that the EGU is out of compliance. But this is not necessarily so. Compliance is to be assessed solely on the basis of whether the average CO2 emission rate over the specified 12-operating month averaging period meets the standard. For more discussion on the 12-operating month compliance period please see section IV.C. of the preamble.
Commenter 0257 noted that EPA is proposing the same monitoring requirements for modified and reconstructed units as it proposed for new units in January, 2014. The commenter submitted extensive comments on the proposed monitoring provisions of the new source proposal and incorporated those comments into this rulemaking docket by reference. 
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0215 supported reliance on the Acid Rain Program (Part 75) monitoring procedures but objected to overly broad or duplicative requirements. The commenter stated that EPA has provided no justification for requiring EGUs to perform monitoring that is different from, let alone more stringent than, Part 75 and has explicitly asserted in its proposed Information Collection Request ("ICR") that it has not proposed to do so. The commenter lists the monitoring and compliance options provided in Part 75 in detail along with the fraction of reporters that use each option.
The commenter stated that the proposed rule generally recognizes the adequacy of Part 75 data by proposing to allow use of two of the four options allowed under Part 75, and by requiring compliance with Part 75 quality assurance and quality control ("QA/QC") and reporting requirements. The commenter stated that the ICR assumes only a "minimal information collection burden" beyond what already is required under Part 75 and the Greenhouse Gas Reporting Rule.  The commenter stated that EPA also in some instances proposes, or solicits comment on imposing new requirements that increase burden and stringency. The commenter supports reliance on Part 75 monitoring procedures, without bias adjustment or missing data substitution, but objects to the proposed elimination of one of the options and imposition of additional requirements for modified and reconstructed units. The commenter stated that EPA has provided no justification for requiring EGUs to perform monitoring that is different from and more stringent than, Part 75 and has explicitly asserted in its proposed ICR that it has not proposed to do so. 
  The EPA has added detail at the request of the commenters that emissions monitoring under Subpart TTTT is to be done according to Part 75 where applicable. Additionally the EPA is not allowing in this final rule for the use of any substitute data as the EPA does not believe it is appropriate to use for complying with the rate-based emission standards put in place by the final rule.
Commenter 0215 requested inclusion of a procedure to obtain an exemption from demonstrating compliance for equipment that is not monitored by Pat 75 or an NSPS, or that alternate monitoring procedures be approved.  The commenter stated that it was not a good use of resources to monitor equipment that operates infrequently and has low emissions. 
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0215 supported the provisions for monitoring "electric output," with two exceptions and with a few clarifications. The commenter stated that the value reported under Part 75 represents an hourly rate and not the total load for the hour. The commenter stated that for hours of partial operation, the value already reported under Part 75 will not represent the actual output for that hour. The commenter stated that, in addition, reported steam load for an hour is reported at the measured temperature and pressure (i.e., is not corrected to ISO conditions). The commenter stated that if EPA intends sources to include partial unit operating hours in compliance calculations, the values already being reported under Part 75 will need some adjustment for use in EPA's proposed compliance calculations. The commenter stated that if EPA wants those adjusted output values to be reported to ECMPS in addition to the values already reported under Part 75, EPA must include that requirement in the rule. The commenter stated that EPA also should clarify in the rule whether it intends that partial unit operating hours be included, and to the extent EPA does intend to include partial unit operating hours, it also must ensure that any data analysis it used to support its emission standard also included such hours. 
   The final rule retains the requirement to use gross energy output in the compliance calculations in addition to allowing stationary combustion turbines with permit requirements to monitor net energy output. For partial operating hours, the gross MW values reported under Part 75 must be adjusted using the unit or stack operating time, to convert them to MWh. 
Commenter 0215 supported the proposal to allow liquid and gaseous fuel-fired EGUs to use the Appendix G in lieu of CEMS, and the proposal to allow, but not require, the use of site-specific F-factors under equation G-4. The commenter stated that the variability in commonly used fuels is not sufficient to warrant determination of a site-specific F-factor for all fuels.  The commenter stated that requiring development of a site-specific F-factor for commonly used fuels would be a waste of time and resources, however, the option to develop such factors is necessary to account for the fact that EPA may not have developed a default factor for some fuels.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets
Commenter 0215 stated that EPA has not provided justification for the proposed requirement to comply with the American National Standards Institute ("ANSI") 2010 C12.20 standard for electricity meters in this rulemaking, which they consider to be burdensome. The commenter stated that EPA has not provided any information to suggest that all EGUs are not already using meters of acceptable accuracy or that requiring compliance with the ANSI standard would not impose additional burdens or require the upgrading of equipment. The commenter stated that EPA has never before found it necessary to impose such requirements because EGUs already have sufficient incentives to ensure that the electricity they generate and use is accurately measured. The commenter stated that some EGUs may have meters that comply with all or parts of the ANSI standard, some do not and the cost of replacing such meters is not insignificant. The commenter stated that the ANSI standard itself is extraordinarily detailed and not at all suited to a regulatory program under which penalties could be sought for a failure to comply. The commenter stated that if EPA establishes limits based on net electric output, EPA must allow EGUs to use existing equipment and methods for metering station service to make the required measurements, and to apply simple apportionment schemes based on unit generation where common station service must be allocated to individual units. The commenter stated that if EPA were to require replacement of existing equipment or to impose more stringent standards on existing equipment, EPA would need to revise its proposed ICR to estimate and solicit input on the additional costs and burdens.
The EPA believes it is necessary to have standardized monitoring for sources to measure the electric output from their facilities especially when sources are complying with output based standards.  The fee to access the ANSI standard is nominal and should not be a barrier for this industry to evaluate the standard and additionally the commenter notes that many EGUs may have monitors that already meet this standard. Additionally, the EPA believes that any source undergoing modification or reconstruction will not have significant challenges in the instillation of monitors that meet the ANSI C12.20 standard.  Therefore, in the final rule, EPA is requiring use of ANSI 0.2 class meters to measure and report electric generation.
Commenter 0215 questions EPA's focus on the accuracy of useful thermal output measurements given the Agency's uncertainty regarding the amount of credit that should be provided for whatever is measured. The commenter stated that although EPA has proposed to allow credit for 75 percent of measured useful thermal output, it also has solicited comment on providing credit for as little as two-thirds and as much as 100 percent. The commenter stated that any accuracy gains that might be achieved from imposing additional requirements would be lost in the noise of the calculations and assumptions used to justify the arrived upon percent credit. The commenter stated that each EGU should be allowed to select the technologies that best suit its needs under the circumstances. The commenter stated that different types of meters, instruments, and calculation methods also provide varying levels of accuracy depending on the steam conditions, which can vary from source to source. The commenter stated that some equipment simply would not benefit from any periodic QA. The commenter stated that thermocouples and resistance temperature detectors (RTDs) either work or fail completely. The commenter stated that manufacturers' recommendations also are not universally appropriate for ongoing maintenance or QA, and are not appropriate for use in rules because they vary from vendor to vendor and can change over time. The commenter stated that performance test codes are not appropriate for ongoing QA because they were designed for performance testing, not long term performance, and although most flow meters probably would meet the ASME MFC standards EPA has not justified imposition of such standards in this context.
Specific monitoring requirements for useful thermal output are not included in this final rule.
Commenter 0215 stated that EPA proposed a new requirement to measure the dimensions of each stack or duct at the flow monitor and reference method sampling location using a laser device.  The commenter stated that the rulemaking record, however, contains no evidence that existing methods are not sufficiently accurate, and no evidence that laser devices would provide significantly more accurate results, and it appears that the requirement imposes additional cost and burden with no corresponding benefit. The commenter stated that if EPA has evidence to support this proposed requirement, EPA should provide it.
  The EPA thanks the commenters for the comments and is finalizing the rule with the requirement to measure stack gas flow according to Appendix A or part 75 and §75.10(a)(3)(i). Additionally the EPA is finalizing measurements of diameter to be required at only 2 locations for circular stacks and 2 locations for each length and width of rectangular ducts.
Commenter 0215 supported  EPA's decision not to solicit comment or propose to apply to modified or reconstructed units a number of additional measurement requirements which EPA solicited comment in its January 2014 proposal for new EGUs to "increase the precision of GHG measurements."
The EPA thanks the commenter for their comments
Commenter 0215 stated that the rule should allow EGUs to report (and include in compliance calculations) a value of 1 or 2 MW for any hour during which monitored gross load is zero.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking docket.
Commenter 0215 stated that if EPA establishes limits based on net electric output, EPA must allow EGUs to use existing equipment and methods for metering station service to make the required measurements and to apply simple apportionment schemes based on unit generation where common station service must be allocated to individual units.
 The final rule allows for both compliance with a gross standard and net standard (if required in an applicable permit for affected stationary combustion turbines) and the combined gross electrical load to be apportioned to the individual EGUs based on the fraction of the total steam load contributed by each unit. If the units are identical, the combined hourly gross electrical load may be apportioned to the individual EGUs according to the fraction of the total heat input contributed by each unit.
Commenter 0215 stated that combined heat and power ("CHP") facilities should not be required to employ any specific technology or quality assurance ("QA") procedures for equipment used to measure useful thermal output because any gains in accuracy from employing a specific technology or procedure would likely would be insignificant relative to other uncertainties in the calculation of creditable output.
The EPA is requiring all monitoring to be consistent with part 75 provisions.
Commenter 0215 requested clarification of the intent of the proposed monitoring system certification requirements for modified and reconstructed units.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets
Commenter 0215 stated that when EPA proposed to include "integrated combustion turbines and fuel cells" in the definition of a post-May 3, 2011 steam generating unit in Subpart Da, EPA recognized that emissions from that equipment likely would not be exhausted through the primary boiler stack and, because the emissions would be relatively small, suggested that they be estimated rather than monitored. The commenter believes that there are few real world application ns for such equipment, at least at fossil-fuel-fired utility boilers but if such equipment were used, continuous monitoring likely would not be warranted. The commenter suggested that EPA include a provision allowing submission and approval of a petition for exemption of emissions that are deminimis from the compliance calculation, or for an alternative means of accounting for any resulting emissions (e.g., a mass balance calculation or engineering estimate) from any integrated equipment that is not otherwise required to be monitored under an NSPS or otherwise accounted for in the primary equipment's monitoring (e.g., by venting the emissions into a stack with CEMS).
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets
Recordkeeping
Commenter 0215 stated that EPA proposes a number of recordkeeping provisions, some of which are overly broad, unnecessary, and in conflict with other provisions. As a result, the commenter objects to them. The commenter also opposes any recordkeeping requirement that duplicates Part 75. The commenter stated that EPA proposes to require compliance with all applicable Part 75 recordkeeping requirements. Proposed Applicability Text, Subpart TTTT section 60.5560(b)-(d), Subpart Da section 60.46Da(i)(1), Subpart KKKK section 60.4391(b). UARG agrees that EGUs relying on Part 75 methods for monitoring CO2 mass emissions should comply with Part 75 recordkeeping for those methods. However, as noted above, the commenter opposes any recordkeeping requirement that duplicates Part 75.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets
Commenter 0213 stated that EPA must require that sources maintain on-site, and make readily available at all times, their records of emission data. The current proposal would permit sources to move records off-site after two years, but this provision would not advance any policy-based goals and would add unnecessary burdens to EPA or state-based enforcement investigations.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter requested EPA include a provision in the rule allowing EGUs to include in compliance calculations a value of 1 MW for any hour during which monitored gross load is zero or for hours with gross generation less than auxiliary loads.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
EPA is proposing the same recordkeeping requirements for modified and reconstructed units as it proposed for new units in January, 2014. Commenter 0257 submitted extensive comments on the proposed recordkeeping provisions of the new source proposal and incorporated those comments into this rulemaking docket by reference.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0215 opposed the proposed five-year record retention period for all of the supporting information for the 12-operating-month rolling average standard, unless EPA can show a special need as required under the Paperwork Reduction Act regulations. The commenter also opposed the proposed on-site requirement if it means that retention of electronic records that can be accessed "onsite" (even if they are physically located offsite) would not be sufficient. 
The commenter also stated that EPA proposes to require retention of records for 5 years from occurrence, except that for EGUs complying with the 84-operating month average option EPA proposes to require retention for 10 years. Proposed Applicability Text, Subpart TTTT section 60.5565(b), Subpart Da section 60.46Da(i)(7), Subpart KKKK section 60.4391(h)(2). For the first 2 years, EPA proposes that the records must be retained onsite. Id., Subpart TTTT section 60.5565(c), Subpart Da section 60.46Da(i)(8), Subpart KKKK section 60.4391(h)(3) 
The commenter opposes the proposed 5 year record retention period for all of the supporting information for the 12-operating-month rolling average standard, unless EPA can show a special need as required under the Paperwork Reduction Act regulations. 5 C.F.R. section 1320.5(d)(2)(iv). To the extent EPA intends to audit the accuracy of a certified report by reference to supporting information, EPA should do so within a reasonable period of time (e.g., 3 years). Absent an audit, the data have little or no usefulness. Part 75 has a 3-year record retention requirement and EPA has not provided any information to suggest that has been inadequate. 40 C.F.R. section 75.57(a). UARG also opposes the proposed on-site requirement if it means that retention of electronic records that can be accessed "onsite" (even if they are physically located offsite) would not be sufficient. Many of the records EPA requires be retained are recorded only in electronic form and, depending upon the facility's management practices, may be retained at a central location in order to facilitate backups and other services. As long as the facility can access the information onsite, there is no reason for it to be physically located there.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets
Commenter 0215 stated that EPA proposes a number or recordkeeping provisions. First, EPA proposes to require maintenance of records specified in section 60.7(b) and (f). Proposed Applicability Text, Subpart TTTT section 60.5560(a), Subpart KKKK section 60.4391(a). These provisions require (1) recording of the occurrence and duration of startup, shutdown, and malfunction periods and periods when monitoring systems are inoperative, and (2) with respect to monitoring systems, recording and retention for two years of all measurements, quality assurance test results, adjustments, and maintenance. The commenter stated that these provisions are overly broad, unnecessary, and in conflict with other provisions. With respect to startups and shutdowns, given that there are no provisions in the proposed NSPS that apply only to startup or shutdown, there is no basis to require records of those periods in this rule. And, the other information addressed in these provisions already is required to be recorded under Part 75, compliance with which also is required under this rule. Presumably, it is for these reasons that Subpart TTTT, Table 3 limits applicability of section 60.7 to the notification requirements in (a)(1) and (a)(3). In light of these duplications and inconsistencies, EPA should remove this subsection.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0215 stated that EPA proposes to require recording of calculations performed to determine (1) total CO2 mass emissions "each operating month," and "each compliance period," (2) gross output for "each operating month," (3) percent valid CO2 rates each compliance period, (4) compliance with each applicable CO2 standard, and (5) any site-specific carbon-based F-factors used. Proposed Applicability Text, Subpart TTTT section 60.5560(c)-(g), Subpart Da section 60.46Da(i)(2)-(5), Subpart KKKK section 60.4391(c)-(g). The commenter does not oppose keeping records of calculations of CO2 mass emissions and gross output for each "compliance period," calculations of percent valid CO2 mass emissions, or calculations to assess compliance. However, because there is no requirement to calculate CO2 mass emissions or gross output for "each operating month," there is no basis to require recording of such calculations. CO2 mass and gross output emissions may be calculated at the end of each operating month, but the value calculated is the total mass emissions and total gross output over the entire compliance period, and not for the operating month. EPA should remove the provisions that refer to operating months.
The EPA has clarified the recordkeeping requirements in the final rule.
Reporting
Commenter 0257 requested EPA include a provision in the rule allowing EGUs to report a value of 1 MW for any hour during which monitored gross load is zero or for hours with gross generation less than auxiliary loads.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
EPA is proposing the same reporting requirements for modified and reconstructed units as it proposed for new units in January, 2014. Commenter 0257 submitted extensive comments on the proposed reporting provisions of the new source proposal and incorporated those comments into this rulemaking docket by reference. 
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0215 stated that they support the language in the Proposed Standards under which quarterly reporting would not be required until there is a compliance value ready to report. Because the data necessary to calculate compliance already are reported under Part 75, there is no reason to require reporting under this rule until the end of the first compliance period. For the first compliance period, EPA must ensure that a full operating month is included.
The commenter stated that EPA's proposal to require compliance with "all applicable" reporting requirements in Part 75 is reasonable, but the wording is overly broad and could be misconstrued. Proposed Applicability Text, Subpart TTTT section 60.5555(c), Subpart Da section 60.46Da(h)(4), Subpart KKKK section 60.4376(d). If read literally, any deficiency in reporting under Part 75 would be a violation of this proposed rule even if it was completely unrelated to this NSPS. EPA should reword this provision to explain that "applicable reporting requirements" means reporting of information needed to calculate lb CO2/MWh - i.e., hourly load and any information used to calculate CO2 mass emissions.
 The he EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0215 stated that they support the proposal to rely on monitoring already performed and hourly data already reported under Part 75 to demonstrate compliance as long as the data used do not include missing data substitution or bias correction factors. However, the commenter would object to any attempt by EPA to use ECMPS to require reporting of any information, codes, calculations, or other information that is not identified both in the rule and in an ICR approved by OMB. If EPA believes that any additional information must be reported to ECMPS to demonstrate compliance with this proposed NSPS, EPA must issue a rulemaking proposal identifying the information and the need for it, and soliciting comment on that proposal. UARG also would object to any attempt by EPA to use electronic auditing software within ECMPS to impose on reporting facilities any requirements or quality assurance criteria that are not identified in the rule. The commenter stated that  EPA also must ensure that the new information required to be submitted by the rule is separately identified in the ECMPS quarterly report and that a mechanism is provided for the facility's owner or operator (or his/her agent) to review and, where the rule requires, certify the accuracy of the new information. As EPA is aware, under 40 C.F.R. section 72.21(b)(2), each submission under Part 75 related to the ARP must be certified as "true, accurate, and complete" by the facility's DR. Under 40 C.F.R. section 75.64(c), the DR also must make certain certifications in support of each "quarterly emissions monitoring report." Under 40 C.F.R. section 72.2, the DR is defined as a person authorized by the owners and operators of an affected source (and all affected units at the source) as evidenced by a "certificate of representation" to represent and legally bind each owner and operator. As a result, those data elements in ECMPS that are required to be reported under Part 75 must be certified by a person meeting that definition of DR. 55
  The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0215 stated that they do not oppose the notification requirements of submission of notices under 60.7(a)(1) (construction date) and (3) (initial startup date), section 60.19 (general provisions regarding time periods, postmarks, etc.), and in section 75.61 (submittal of test notifications, notification of commercial operation, notification of certification deadline, etc., to the appropriate EPA Regional Office and state). However, the commenter stated that EPA should exempt the notices in section 75.61 from the duplicate reporting requirements in section 60.4(a) and (b), which require that "[a]ll requests, reports, applications, submittals, and other communications to the Administrator pursuant to this part" be submitted "in duplicate" to the appropriate EPA Regional Office and to any delegated state. Because section 75.61 already requires submission to those officials, there is no basis for requiring additional reporting "in duplicate" under Part 60.
The commenter supported EPA's proposal to exempt facilities from compliance with section 60.7(c) with respect to Subpart TTTT. Part 75 already requires reporting of the status of the relevant monitoring systems, and EPA has proposed new requirements for reporting of percent valid data and excess emissions periods. If EPA proceeds with implementation of this NSPS through revisions to Subparts Da and KKKK, EPA will need to include in those revisions an explicit exemption from section 60.7(c) in order to avoid those duplicative reporting requirements.
Regardless of how it is implemented (i.e., through Subpart TTTT or Subparts Da and KKKK), the commenter stated that EPA must exempt all of the electronic reporting requirements in the NSPS from section 60.4. If read literally, section 60.4 would require facilities to extract from the current Part 75 electronic quarterly reports all of the information required to be reported under this NSPS and then create and submit in duplicate a totally new report to EPA Regional Offices and states. Such a requirement clearly is not contemplated by this proposal and would not be reasonable. EPA should foreclose any such unreasonable reading of this requirement by including an explicit exemption from section 60.4 for any information reported to ECMPS. If EPA Regional Offices or states want the information, they can obtain it from the CAMD. If EPA believes that facilities should report this information directly to EPA Regional Offices and to states, EPA will need to propose a new rule that does not rely on or require reporting to ECMPS.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Regulatory Text
Multiple commenters (0176, 0192, 0247, 0260) noted that EPA did not include proposed regulatory text in the Federal Register notice for the NSPS for modified/reconstructed sources. Commenter 0260 argued that this is a violation of EPA's duty to provide adequate notice of the proposed rulemaking under section 307 of the CAA. See 42 U.S.C. 7607(d)(3).   
Commenters 0192 and 0247 noted that EPA directed commenters to a technical support document in the docket to find the language that EPA was proposing to adopt. However, EPA issued two documents that contain significantly different regulatory language--a "proposed applicability" version and "broad applicability" version. The documents show revisions to the regulatory text in the January 2014 proposal of the NSPS for new sources. Commenter 0260 argued that including the proposed regulatory text in the docket does not correct the error of not providing adequate notice of the proposed rulemaking. According to commenter 0247, there is no explanation in the docket of which of these two documents commenters should be reviewing and why. Commenter 0247 also noted that the phrase "broad applicability" used in one of the documents is not used in the preamble to the proposed rule, which would have provided some context to help commenters understand how those memoranda were used in the proposal.
Commenter 0192 stated that, because neither document is specifically referenced in the proposed rule, it is unclear what sources EPA is proposing to regulate in this proposal. Even more troubling, the "broad applicability" version would remove virtually all of the applicability thresholds included in the January 2014 proposal and instead use them to create what appears to be a new subcategory of sources to which no numeric emission standard is applied. However, such sources would still be considered "affected EGUs" and would, therefore, be subject to certain monitoring, recordkeeping, and reporting obligations, even if no numeric standard of performance applied. Further, by removing applicability criteria related to a source's intended purpose at the time of construction, the broad applicability version would create a risk that facilities could become subject to numeric standards of performance long after construction, modification, or reconstruction as a result of unforeseen changed circumstances. To avoid the risk and confusion associated with EPA's approach, commenter 0192 urged EPA to withdraw the rules and publish a single proposal in the Federal Register that includes--subject to their other comments--all of the applicability criteria from the January 2014 proposal for newly constructed sources.
EPA disagrees that commenters did not have adequate information to allow them to comment on the various options for regulatory text.
Commenter 0176 noted that EPA asked for additional approaches to address potential unintended environmental impacts from regulating NGSC units as proposed. If EPA does not exclude NGSC in the final NSPS, then commenter 0176 suggested that EPA revise the applicability section in a manner set forth below. The suggested revisions would address the unintended environmental consequences of the proposed rule arising from its potential to limit quick start NGSC usage needed for grid reliability. The commenter proposed adding new subsections (6) and (7) as follows to the applicability section in the proposed new unit NSPS in section 60.4305(c) and asked for the same corresponding change to the modified unit NSPS: 
(c) For purposes of regulation of greenhouse gases, the applicable provisions of this subpart affect your stationary combustion turbine if it meets the applicability conditions in paragraphs (c)(1) through (c)(7) of this section. . . .
(6) Does not meet both of the following requirements: (1) is capable of injecting 75% of total generation unit nameplate capacity into the grid from a shutdown state, within 15 minutes of a dispatch directive from the dispatching Independent System Operator (ISO) or balancing authority, and (2) is capable of completing a minimum of two Startup/Shutdown cycles within a 24 hour period; and
(7) Does not participate as a Market Dispatched Generation Resource (MDGR), or the stationary combustion turbine is not within a Balancing Authority where combustion turbines support reliability of the grid and where dispatch is controlled by a local Balancing Authority that is not under the control of the stationary combustor owner or operator.
Commenter 0176 acknowledged that EPA is considering and taking comment on changing the "one third potential electric output" sales criteria to "the design net efficiency times the potential electric output" for simple cycle combustion turbines. See 79 FR 34980. EPA believes this would have the effect of allowing NGSC to sell 38% of their electric output before the emission standard would apply. The commenter did not support this change and provided language in their comments that would address the problematic impacts that are associated with requiring the installation of HRSG units that would limit the quick start capabilities of NGSC units as set forth herein. NGSC units play and will continue to play a critical role to support renewables energy and this option being considered by EPA would still result in the adverse impacts described above.
Commenter 0176 stated that these new applicability sections would allow NGSC units to operate in ways that support renewables and grid reliability and avoid the unintended consequence of increasing overall emissions and reducing wind generation.
The commenter argued that adding section 60.4305(c)(6) would ensure that only those NGSC units with quick start capabilities would be excluded. As stated in the testimony of Mr. Hess of their company in Attachment 2 of their comment, recent advancements in NGSC technology have reduced start-up time to as little as 70% of maximum output in approximately 10 minutes and full power in approximately eleven minutes on some NGSC units. As further stated in the Affidavit of Mr. Nickell of the SPP (in Attachment 1 of their comment), this fast start capability makes NGSC uniquely suited to back up intermittent wind generation. Section 111(b) of the Clean Air Act promotes this new technological improvement in NGSC. As discussed in the proposed rule, expanded use and development of technology is one of the factors EPA must consider when determining BSER. Based on legislative history, the EPA identifies three different ways that Congress designed CAA section 111 to authorize standards of performance that promote technological improvement: (i) the development of technology that may be treated as the "best system of emission reduction . . . adequately demonstrated"; under section 111(a)(1); (ii) the expanded use of the best demonstrated technology; and (iii) the development of emerging technology. Because NGSC units, in conjunction with renewable energy can provide "virtual base load generation" that will benefit grid reliability for this growing renewable energy resource, the commenter believes that these changes to the applicability section are also consistent with the "technology forcing" nature of section 111(b).
The commenter argued that adding section 60.4305(c)(7) and the definition for MDGR and Balancing Authority would also ensure that economics will control the dispatch of NGSC units. Those units that are excluded will only be those that are dispatched by the market or Balancing Authority, and not those dispatched by the NGSC unit owner or operator. The commenter was aware that EPA is concerned that NGSC owners not be in a position to "game the system." Limiting the exemption to situations where a central ISO or Balancing Authority controls the dispatch of generation assures that NGSC owners cannot dispatch units where those units are not either economical or needed for system reliability, including where units may be needed to maximize utilization of renewable generation with the potential to reduce overall CO2 emissions. As Mr. Nickell of SPP stated in his affidavit, due to increased operating costs, NGSC units are and will continue to be the last to be dispatched unless there is a good reason to dispatch them out-of-merit for support of grid reliability (i.e., to support variable wind due to their fast start capability upon notification, as discussed above.). In addition, since the implementation of the SPP Integrated Marketplace, SPP's dispatch mix has experienced an increase in the dispatch of NGSC units and an increase in an output of wind generation from 2013 to 2014. Commenter attached an affidavit of Mr. Lanny D. Nickell, SPP, and a testimony of Mr. Tom Burke, Golden Spread.
The EPA has added detail in the applicability sections of the rule and clarified what applicable monitoring and recordkeeping EGUs have to do depending on what standard is applicable to them.  The final rule has an operational element for an EGU to determine what emission standard is applicable and for more discussion on this topic see sections VIII.C. and IX.A.3 of the preamble.
Commenter 0192 suggested that EPA consider revising the applicability criteria for affected sources to exclude CHP units from the industrial and manufacturing sectors and proposed that EPA accomplish this exclusion by adopting the following text for sections 60.46(a), 60.4305(c) and 60.5509(a)(3): 
Section 60.46Da Standards for carbon dioxide (CO2).
(a) Your affected facility is subject to this section if it meets the conditions specified in paragraphs (a)(1) or (a)(2) of this section, except as specified in paragraph (b) of this section.
(1) Construction commenced after January 8, 2014 and meets the conditions specified in paragraphs (a)(1)(i), (a)(1)(ii), and (a)(1)(iii) of this section.
(i) The affected facility was constructed for the purpose of supplying more than 60% of its gross energy output as net-electric sales to a utility distribution system on a 3-year rolling average basis;
(ii) The affected facility combusts fossil fuel for more than 10% of the heat input during any 3 consecutive calendar years; and
(iii) The affected facility supplies more than 60% of its gross energy output as net-electric sales to a utility distribution system on a 3-year rolling average basis.
(2) Modification or reconstruction commenced after June 18, 2014 and meets the conditions specified in paragraphs (a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of this section.
(i) The affected facility was constructed for the purpose of supplying more than 60% of its gross energy output as net-electric sales to a utility distribution system on a 3-year rolling average basis;
(ii) The affected facility combusts fossil fuel for more than 10% of the heat input during any 3 consecutive calendar years; and
(iii) The affected facility supplies more than 60% of its gross energy output as net-electric sales to a utility distribution system on a 3-year rolling average basis. 
Section 60.4305 Does this subpart apply to my stationary combustion turbine?
(c) For purposes of regulation of greenhouse gases, the applicable provisions of this subpart affect your stationary combustion turbine if it meets the applicability conditions in paragraphs (c)(1) through (c)(5) of this section.
(1) Commenced construction after January 8, 2014 or it commenced reconstruction or modification after June 18, 2014;
(2) Has a design heat input to the turbine engine greater than 73 MW (250 MMBtu/h);
(3) Combusts fossil fuel for more than 10% of the heat input during any 3 consecutive calendar years.
(4) Combusts over 90% natural gas on a heat input basis on a 3-year rolling average basis; and
(5) Was constructed for the purpose of supplying, and supplies, more than 60% of its gross energy output as net-electric sales to a utility distribution system on a 3-year rolling average basis. 
Section 60.5509 Am I subject to this subpart?
(a) Except as provided for in paragraph (b) of this section, the subpart applies to any steam generating unit, IGCC, or stationary combustion turbine that commenced construction after January 8, 2014 or commenced modification or reconstruction after June 18, 2014 that meets the relevant applicability conditions in paragraphs (a)(1), and (a)(2), or (a)(3) of this section.
(1) A steam generating unit or IGCC that commenced construction after January 8, 2014 and has a base load rating greater than 73 MW (250 MMBtu/h) heat input of fossil fuel (either alone or in combination with any other fuel), was constructed for the purpose of supplying, and supplies more than 60% of its gross energy output as net-electric sales to a utility distribution system on a 3-year rolling average basis, and combusts fossil fuel for more than 10.0 percent of the heat input during a 3 year rolling average basis.
(2) A steam generating unit or IGCC that commenced modification or reconstruction after June 18, 2014 and has a base load rating greater than 73 MW (250MMBtu/h) heat input of fossil fuel (either alone or in combination with any other fuel); was constructed for the purpose of supplying, and supplies more than 60% of its gross energy output as net-electric sales to a utility distribution system on a 3-year rolling average basis; and combusts fossil fuel for more than 10% of the heat input during a 3 year rolling average basis.
(3) A stationary combustion turbine that has a base load rating greater than 73 MW (250 MMBtu/h); was constructed for the purpose of supplying, and supplies more than 60% of its gross energy output as net-electric sales to a utility distribution system on a 3-year rolling average basis; combusts fossil fuel for more than 10% of the average annual heat input during a 3-year rolling average basis; and combusts over 90% natural gas on a heat input basis on a 3-year rolling average basis.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0215 noted that in Subpart Da, EPA describes the proposed standard for large reconstructed and modified units of 1,900 lb CO2/MWh as equivalent to 820 kg CO2/MWh of net energy output. Proposed Applicability Text, Subpart Da Section 60.46Da(c)(2)(ii) and (3)(i)(C). However, in Subpart TTTT, EPA describes the same standard as equivalent to 860 kg CO2/MWh of net energy output. Proposed Applicability Text, Subpart TTTT, Table 2. In Subpart KKKK, EPA describes the 1,000 lb/MWh standard for large NGCC units as equivalent to 450 kg CO2/MWh of gross output and the 1,100 lb/MWh standard for small NGCC units as equivalent to 500 kg CO2/MWh of gross output. Proposed Applicability Text, Subpart KKKK, Tbl. 2. However, in Subpart TTTT, EPA describes those same standards as equivalent to 460 kg CO2/MWh of gross output and 510 kg CO2/MWh of gross output, respectively. Proposed Applicability Text, Subpart TTTT, Tables 1 and 2. The commenter believes that the Subpart TTTT standards for boilers and IGCC units and the Subpart KKKK standards for turbines are the more accurate conversions and that the other values are in error.
The EPA thanks the commenter for their response and the EPA is only finalizing subpart TTTT of part 60 in this rulemaking and not finalizing changes to subparts Da and KKKK of part 60.
Commenter 0215 stated that they have identified several inconsistencies in the proposed regulatory language. The commenter felt that EPA should carefully review its proposed rule language to ensure consistency.
The EPA thanks the commenter for their comment and the EPA has clarified subpart TTTT of part 60 in this rulemaking.
10.4.1 Subpart TTTT or Subpart Da and KKKK
On the critical questions of which facilities and activities would be subject to the proposed rule, commenter 0247 said EPA had not provided commenters with clear, consistent proposed regulatory language and stated that it is not even certain what language EPA is proposing to adopt. Nor has EPA, in most cases, explained the reasons for departing from current regulatory language or for using inconsistent language in different subparts. These deficiencies require correction and an opportunity for the public to comment before a final rule can be adopted. 
To illustrate, the commenter noted that the "proposed" new regulatory text found in the docket for the proposed rule is shown as two alternatives: amendments to the existing EGU NSPS at 40 CFR part 60, subparts Da and KKKK, or a wholly new subpart TTTT, which the commenter indicated do not contain the same applicability language. The commenter argued that EPA has not explained the reason for the differences. The commenter also noted that the Regulatory Impact Statement included in the docket for the proposal (Docket ID EPA-HQ-OAR-2013-0603-0025), which might otherwise help commenters understand what EPA was actually proposing to require, devotes only a handful of pages to NSPS for modified and reconstructed EGUs and says very little about applicability to the proposed standards. Because it addresses costs and benefits only by looking at a hypothetical plant, it gives no indication of which existing facilities EPA believes would be subject to the proposed rule.
Despite the extensive history behind the applicability criteria in existing subpart Da, the commenter stated that the proposal indicates EPA is considering numerous changes to the language but in many cases does not provide a reasoned explanation, or any explanation at all, for the change.
For example, in the "Proposed Regulatory Text" document, if subpart Da was amended, the commenter noted it would apply to modified or reconstructed EGUs "constructed for the purpose of supplying more than one-third of its potential electric output." The current subpart Da reads similarly. But if EPA instead were to promulgate a new subpart TTTT, EPA is proposing that it apply to a modified or reconstructed EGU "constructed for the purpose of supplying one-third or more of its potential electric output." The proposal does not explain why subpart TTTT replaces the "more than" criterion with "or more."
Likewise, in the "Proposed Regulatory Text" document, the commenter noted that the determination of whether a CHP unit is eligible to calculate its "net electric sales" by subtracting power purchased to operate the thermal host is applied over a three-year rolling average in proposed amendments to subpart Da. However, the corresponding proposed language if EPA promulgates a new subpart TTTT would not determine CHP eligibility on a three-year rolling average basis. (There is no indication what time period would apply in subpart TTTT, so presumably the criterion would have to be met each year- compare "Proposed Regulatory Text" document p. 22 of 49 with p. 40 of 49). These and many other unexplained differences in regulatory text among the existing NSPS and the several versions of proposed language EPA has offered with the proposal need to be rationalized, and if applicability language different from the current regulations is needed, EPA must explain why.
EPA disagrees that commenters did not have adequate information to allow them to comment on the various options for regulatory text.
Commenter 0187 noted that EPA co-proposed two options for codifying the proposed standards of performance for affected modified and reconstructed units--codifying the standards in existing 40 CFR part 60, subparts Da and KKKK, or creating a new subpart TTTT, which would include all standards of performance for CO2 (79 FR 34965). The commenter supported creating a new subpart TTTT and including all of the CO2 standards within one subpart.
The EPA agrees with the commenter and is only finalizing TTTT of part 60 in the final rulemaking.
Multiple commenters (0197, 0214, 0242, 0260) supported EPA's proposal to codify the provisions in their respective subparts (subpart Da for IGCC and boilers and subpart KKKK for turbines), rather than creating a new subpart TTTT. Commenter 0260 stated that this approach would ensure consistency with EPA's longstanding approach of compiling all performance standards for a single source category into a separate subpart of the CFR, rather than creating a new subpart that combines source categories and only addresses certain standards, which the commenter said would be confusing and inefficiently organized. 
Commenter 0197 stated that codifying the proposed regulations in their respective subparts would make referencing the appropriate NSPS easier for state and local air pollution control agencies and the owners and operators of the affected facilities. All of the applicable regulations would be in one subpart, thereby minimizing confusion. In addition, there would be no need to reproduce definitions that are already contained in the respective subparts (i.e., definition of fossil fuel). Also, if future data supports changing an emissions limitation for one type of fuel or technology, it can be addressed without opening the entire regulation to comment. Therefore, while codifying the proposed regulations in a new subpart may not cause undue burden to the owner/operator or the permitting agencies, the commenter recommended codifying the provisions in their respective subparts.
Commenter 0213 stated that, with several exceptions that they describe elsewhere in their comment, EPA must retain the applicability provisions for affected sources that exist in the current regulations for subparts KKKK and Da, as well as those for subparts Db and Dc, which regulate smaller steam EGUs and gasification plants that do not utilize combined cycle technology. However, the commenter did not indicate whether this meant codifying the provisions in those existing subparts or simply ensuring that the applicability provisions in a new subpart TTTT are the same as those in the existing subparts.
Commenter 0214 argued that EPA had not taken the necessary steps required by CAA section 111(b) to set standards under subparts Da and KKKK, much less a new subpart TTTT. Without taking these steps for either approach, the commenter said EPA's actions would be illegal if finalized as proposed. Putting aside these issues, however, to the extent that EPA fails to rescind the proposal, the commenter supported codification of a final rule reflecting the proper application of section 111(b) into existing subparts Da and KKKK, instead of combining these separate source categories into a new subpart TTTT.
Commenter 0214 noted that the source category that constitutes subpart TTTT is not itself identified in the CAA section 111(b)(1)(A) list of categories of stationary sources. See 36 FR 5,931 (Mar. 31, 1971); 43 FR 38,872, 38,874 (Aug. 31, 1978); 40 CFR 60.16 (Aug. 21, 1979). In order to add a source category, the CAA requires EPA to prepare a listing decision. This listing is a prerequisite to promulgating NSPS standards, and it is only after inclusion on the CAA section 111(b)(1)(A) list that EPA may promulgate federal standards of performance for new sources. See CAA section 111(b)(1)(B) ("Within one year after the inclusion of a category of stationary sources in a list under subparagraph (A), the Administrator shall publish proposed regulations, establishing Federal standards of performance for new sources within such category."). In EPA's January 2014 re-proposed NSPS and again in EPA's MRPS, EPA did not revise the list of categories of stationary sources to include the subpart TTTT source category.
Commenter 0214 further stated that EPA cannot list categories of sources and then establish NSPS unless it has determined that the pollutant(s) from the source category "causes, or contributes significantly to, air pollution which may reasonably be anticipated to endanger public health or welfare." See CAA section 111(b)(1)(A). The commenter argued that EPA has failed to make the required endangerment and significant contribution finding for CO2 regardless of where these standards will be codified. This failure is particularly important with regard to evaluating TTTT because CO2 is the only pollutant for which subpart TTTT would have a standard, and it is the only pollutant for which this category would be constructed from the CAA section 111(b)(1)(A) list. For these reasons, but only after all the prerequisites of section 111 are satisfied, the commenter stated that EPA should promulgate CO2 standards for modified and reconstructed sources under subparts Da and KKKK.
Commenter 0242 argued that reclassification using a new subpart TTTT that would include GHG standards for all covered sources would represent a significant departure from precedent in establishing NSPS-- which has in the past been based on what has been achieved in practice--in that several different types of equipment are combined under a single standard based on their common industry. The commenter argued that this is EPA clearly picking a "winning fuel," natural gas, over a "losing fuel," coal. This type of approach goes beyond EPA historical precedent and regulatory authority. Section 111(b)(5) forbids EPA from restricting owners and operators to a particular technology to meet a standard of performance.
This final rule includes all the requirements in subpart TTTT. See the preamble of this rule for the PEA's rationale. 
Commenter 0215 stated that EPA proposes to exempt Subpart TTTT from sections 60.8 (addressing performance tests, notice of performance tests, performance test reports, and audit sample requirements), 60.11 (including compliance requirements and opacity requirements), 60.14 (addressing modification), 60.15 (addressing reconstruction), 60.16 (priority list), and 60.18 (addressing general control device requirements). Proposed Applicability Text, Subpart TTTT section 60.5570 & Tbl. 3. UARG does not understand why the tests for modification and reconstruction in sections 60.14 and 60.15 would not apply to this proposal and, if they would not, what tests EPA proposes would apply. If the exclusion of those sections was intentional, EPA must issue a proposal defining modification and reconstruction for this subcategory.
 Commenter 0215 also stated that in the proposed Subpart Da, applicability is limited to affected facilities that were constructed for the purpose of supplying and, for new units that actually supply "more than one-third" of their potential electric output and more than 219,000 MWh net electric output to a utility power distribution system. Proposed Applicability Text, Subpart Da section 60.46Da(a)(1); see also 79 Fed. Reg. at 34,972 (describing Subpart Da). That provision is consistent with the current Subpart Da definition of "electric utility steam-generating unit" in section 60.41Da, which EPA does not propose to change, and EPA?s description of its proposal for CO2 standards for new boilers in January 2014.56 79 Fed. Reg. at 1445. However, in Subpart TTTT, EPA proposes to extend applicability to affected Subpart Da facilities that were constructed to supply and, for new units, that actually supply "one-third or more" of their potential electric output as net electric sales. Proposed Applicability Text, Subpart TTTT section 60.5509(a)(1), (2) and (3). The extension is not explained and is not appropriate.
The EPA agrees with the commenter that 60.14 and 60.15 should be made applicable to the final rule for modification and reconstruction and is making that clarification as the EPA will not be setting new definitions of what modification and reconstruction are in this rulemaking.  Additionally the applicability of the regulation to affected EGUs has been updated and the use of the new subpart TTTT makes this clearer.
10.4.2 Definitions
EPA's existing regulations define "reconstruction" as the "replacement of components of an existing facility to such an extent that (1) the fixed capital cost of the new components exceeds 50% of the of the fixed capital cost that would be required to construct a comparable new facility, and (2) it is technologically and economically feasible to meet the applicable standards." While acknowledging that few existing EGUs will undertake projects that will qualify a unit as reconstructed, EPA requested comment on whether to adjust the upper capital cost threshold within the range of 75-100% of the cost of an entirely new and comparable facility, such that facilities that exceed the limit become subject to new plant standards. EPA also requested comment on whether to retain the second part of the definition. 
EPA is not making any change to the regulatory definition of "reconstruction" in 40 CFR 60.15.
Multiple commenters (0131, 0165, 0183, 0195, 0197, 0242, 0247) objected to EPA's proposal to establish an upper threshold of 75-100% of the cost of an entirely new facility to classify a reconstructed source as a new source. 
EPA is not making any change to the regulatory definition of "reconstruction" in 40 CFR 60.15, and is not finalizing any upper threshold of costs to be used to distinguish reconstructed sources from newly constructed sources.
Commenter 0244 stated that EPA must specify in its final rule that, for the purposes of defining a reconstructed source, a "comparable entirely new unit" refers to a new source with the same technology and specifications as the existing source that is being overhauled. Facility owners have an incentive to define "comparable entirely new unit" in a manner as expensive as possible in order to avoid reaching the 50 percent threshold for fixed capital costs, at which point the source is defined as a reconstructed unit and must comply with the performance standards for such units. However, EPA has consistently interpreted 40 CFR 60.15 such that a "comparable entirely new unit" is simply a new version of the existing facility in question, and not a new plant with different and updated technology (such as a coal plant equipped with CCS technology). For instance, the agency makes this clear in a 1997 applicability determination letter from Region 9 regarding a gasoline bulk terminal replacement: 
The commenter said the cost comparison should be for replacement as the facility existed prior to the replacement project (i.e., like for like replacement). For example, if a facility had 100 feet of three inch piping from the premium gas pump to the rack, and it was replaced with 150 feet of 4 inch piping, the facility should state the cost of the 4 inch piping as part of the actual project, but the cost for the comparable equipment should be for 100 feet of new 3 inch pipe. See Letter from Ron Krzywosinski, EPA, Region 9, to David Howecamp, Re: Gasoline Bulk Terminal Reconstruction and Comparable Facility, ADI Control No. 0000081 (Apr. 4, 1997).
The commenter noted that a Region 1 applicability determination letter from 1999 reflects the same position: The term "comparable entirely new facility" would consist of a new boiler with identical components to the repaired boiler. Although a new boiler would be subject to the NSPS and may have air pollution control equipment or newer pollutant reduction design features such as low NOx burners, reconstruction calculations do not include air pollution control equipment and must compare like components. See Letter from Michael P. Kenyon, EPA, Region 1, to Christine A. Flass, Re: Reconstruction of Oil-Fired Boiler, ADI Control No. 0200048 (Sep. 3, 1999).
According to the commenter, other EPA offices have reached similar conclusions. See, e.g., letter from Michael Alushin, EPA, CAMPD, to Ellen Radow Sadat, Re: Reconstruction of a Stationary Combustion Turbine, ADI Control No. 0800031 (Feb. 28, 2008), attached as Ex. 13; Letter from James T. Wilburn, EPA, Region 4, to Richard E. Grusnick, Re: Parallel Brown Stock Washer Systems, ADI Control No. 0200030 (June 16, 1988 The Agency has also made clear that "when determining the cost of the comparable entirely new facility, one must include all of the components identified in the definition of the affected facility [in the applicable regulations], but cannot include components outside of the defined affected facility." See Letter from Kenneth Gigliello, EPA, CAMPD, to Laurie Guthrie, Re: Gas Turbine Refurbishment and Commence Construction, ADI Control No. 0900067 (July 3, 2008). Under the language of the proposed new source and reconstructed source rules, a "steam generating unit" is defined as "any furnace, boiler, or other device used for combusting fuel for the purpose of producing steam (nuclear steam generators are not included) plus any integrated equipment that provides electricity or useful thermal output to either the boiler or auxiliary equipment." 79 FR 1516 (proposed 40 CFR 60.5580). This definition only covers the boiler itself and any integrated generating equipment--it does not encompass pollution control technology such as CCS systems.
The commenter also noted that, at the time EPA first defined reconstructed sources, it made clear that "[c]osts associated with the purchase and installation of air pollution control equipment (e.g., baghouses, electrostatic precipitators, scrubbers, etc.) are not considered in estimating the fixed capital cost of a comparable entirely new facility unless that control equipment is required as part of the process (e.g., product recovery)." 40 FR 58,416. The law on this point could hardly be clearer. Nevertheless, to deter source operators from raising meritless arguments to the contrary, the commenter urged EPA to state explicitly in the final rule that the term "comparable entirely new facilities" does not include CCS systems at coal-fired EGUs, but refers only to new equipment of the kind that both appears at the existing plant and meets the definition of "steam generating unit" that appears in the regulations.
This final rule does not change the reconstruction provisions included in the general provisions.
Multiple commenters (0192, 0193, 0258, 0260) objected to EPA's proposal to expand the definition of "affected facility" to include co-located non-emitting energy generation equipment that is included in the facility operating permit but not integrated into the operation of the affected facility. 79 FR 34,979. Commenter 0193 noted that EPA's objective in proposing this change was to avoid potential circumvention of the emission standards by sources that may rely on co-located non-emitting energy generation equipment at the facility. EPA also stated that the provision would provide additional flexibility to the regulated community through additional compliance options. While this may be true, commenter 0193 remained concerned over the effect this provision may have on discouraging the deployment of non-emitting generation. The commenter suggested that further discussion and understanding is needed on the full range of implications that could follow from making such a significant change to the definition of source. 
In addition to expanding the definition of "affected facility," commenter 0260 noted that EPA also proposed to include within the definition of a "utility boiler," "IGCC unit," and "stationary combustion turbine" that is subject to the proposed requirements, any integrated device that provides electricity or useful thermal output to the boiler, the stationary combustion turbine or to power auxiliary equipment. The commenter 0260 that the proposed expansion of the definition of facilities would be a significant departure from past EPA policy, as contained in Agency guidance documents and NSPS applicability determinations, which has long taken a narrow approach when determining the boundaries of an affected facility. For example, EPA guidance makes clear that equipment outside of the boiler is not part of the affected facility for NSPS purposes under 40 CFR part 60, subpart Da. An EPA guidance memorandum on the topic clarifies that a modified pulverized coal-fired steam generator is defined as including the pulverizer system, the combustion air system, the steam generation system, the draft system, and the fuel combustion system. It does not include equipment like the turbine. Applicability determinations also make clear that an affected facility under subpart Da includes only the steam generating unit. A diagram attached to an applicability determination for the Florida Electric Power Coordinating Group shows that equipment like the turbine, generator, and condenser are not part of the affected facility. Similarly, in an applicability determination issued to NRG Energy, EPA noted that "a turbine is not part of the existing facility (i.e., the electric utility steam generating unit)." EPA should not reverse its long-standing, consistent policy of narrowly interpreting the boundaries of affected facilities. Doing so would upset decades of EPA policy and confuse issues already addressed in past applicability determinations.
Commenter 0192 argued that the proposed NSPS rules are intended to regulate CO2 emissions from fossil fuel-fired EGUs, 79 FR 34,960, and there is no basis for including other energy generating equipment that does not emit CO2 at all. Further, the fact that non-emitting energy generation equipment is included in an operating permit provides no basis for including them within the scope of the section 111 program. As EPA recognizes, a site may be much broader than an affected EGU, see, e.g., 79 FR 1489, and, as a result, an operating permit may cover a number of units beyond an EGU that may undergo a modification or reconstruction. There is no reason to include non-emitting energy equipment simply because it happens to be co-located at the same site.
Commenter 0258 noted that the EPA appears to be proposing a definition of the "affected facility" for new and modified sources that differs from the "affected facility" as defined in the proposed NSPS, 79 FR 1430, 1511 (Jan. 8, 2014), and in the proposed performance standards for existing sources ("ESPS"), 79 FR 34830, 34954 (June 18, 2014). Commenter 0258 argued that the EPA must apply consistent definitions across these three rulemakings.
According to commenter 0258, the EPA noted in the Legal Memorandum for the ESPS that these three rulemakings are interrelated and all address the same "affected EGUs." EPA, Legal Memorandum for Proposed Carbon Pollution Emission Guidelines for Existing Electric Utility Generating Units, at 11 ("EPA Legal Memorandum"). Indeed, section 111(d) of the CAA provides that a source can be regulated under an existing source standard only if "a standard of performance under this section would apply if such existing source were a new source ..." 42 U.S.C. 7411(d). The EPA argued that its authority to issue an ESPS is predicated not only on the issuance of the NSPS, but also on issuance of the new and modified source rule. See EPA Legal Memorandum at 12-13. Therefore, EPA regulations must treat the "new source" and "existing source" referenced in the statute as within the same defined category of "sources."
Commenter 0258 also argued that the provisions governing the definition of the "affected facility" are critical to understanding the applicability of the rules to a source's operations. Without a consistent definition of an "affected facility," sources could be subject to potentially conflicting requirements. For example, a source could fall within the definition of "affected facility" under the rule applicable to modified and reconstructed sources, yet fall outside the definition of an "affected facility" subject to the ESPS. The EPA should avoid confusion inherent in finalizing inconsistent applicability language and adhere to a single definition of the term "affected facility." The specificity with which the EPA has defined the "affected facility" in the redline revisions to subpart Da set forth in the June 2014 Memorandum, including the proposed definitions of "net electric sales" and "net-electric output" found in proposed revisions to 40 CFR 60.46a(k) is helpful; however, the EPA must clarify that the "affected facility" and associated definitions will be consistent across the three rulemakings governing CO2 emissions from "affected" EGUs.
Commenters 0142 and 0242 objected to EPA's proposal to amend the definition for "steam generating unit" to replace the existing language "plus any integrated combustion turbines and fuel cells" with the new language "plus any integrated equipment that provides electricity or useful thermal output to either the affected facility or auxiliary equipment" to read as follows: "any furnace, boiler, or other device combusting fuel for the purpose of producing steam (nuclear steam generators are not included) plus any integrated equipment that provides electricity or useful thermal output to either the affected facility or auxiliary equipment." EPA stated they made this definition change in order to avoid circumvention of the intent of the emission standards (e.g., by having auxiliary equipment provide steam to the EGU to increase the output of the EGU and not including the CO2 emissions in determining the emission rate). While commenter 0142 understood the EPA's reasoning for the proposed definition change, the commenter argued that the EPA should not expand the source category to include other emissions units regulated in other existing source categories. The expansion of the source category does not account for the numerous configurations of plants, nor has EPA evaluated the effect of expanding the applicability on BSER. Instead of expanding the definition of steam generating unit, EPA should address what parameters are included and what parameters are not included in the demonstration of compliance with the standard. Commenter 0242 feared that EPA may be implying emergency generators could also become subject to the rules.
 This final rule does not include co-located non-emitting generating sources. Integrated equipment is included to assure the units do not circumvent the requirements of this final rule and to add additional compliance options for the regulated community. 
Commenter 0260 agreed with EPA that projects involving the installation of add-on control equipment required to meet CAA requirements for criteria and hazardous air pollutants should be exempted from the definition of "modification" under the current NSPS regulations. 79 FR 34,970. For this reason, the proposed standards would not apply to units undertaking such projects. Instead, these units would remain subject to regulation under section 111(d). The exemption for pollution controls in 40 CFR 60.14(a)(5) avoids penalizing companies' efforts to comply with other environmental regulations and should be maintained. 
Other commenters (0152, 0169, 0258) requested that EPA clarify the definition of "modification," for varying reasons. Commenter 0169 noted that, with certain exceptions, EPA defines a "modification" to mean "a physical or operational change that increases the source's maximum achievable hourly rate of emissions." 79 FR 34992; 42 U.S.C. 11l(a)(4); 40 CFR 60.2, 60.14(a). One important exception is the so-called PCP exception. 79 FR 34970 (citing 40 CFR 60.14(e)(5)). EPA recognizes that some facility improvements may involve equipment changes to improve efficiency that actually increase a source's maximum achievable hourly emission rate, even while decreasing the actual output based emissions rate. Under the PCP exception, modifications undertaken for the primary purpose of installing pollution control technology do not subject the source to EPA's modified source rule. Commenter 0169 requested that EPA provide examples of pollution control projects that have fallen under this exemption in the past and evaluate before finalizing a rule.
Commenter 0152 agreed with EPA that few projects are expected to meet the NSPS definition of "modification" and trigger this proposed standard. The majority of efficiency improvement projects do not typically increase the emission rate of a pollutant, and many other projects will fit within the exclusion for pollution control projects. For clarity and certainty, commenter 0152 requested that EPA provide that all efficiency improvement projects are excluded from the NSPS definition of a modification, and that EPA consider ways to minimize the impact of PSD NSR as well.
Commenter 0258 stated that there is a discrepancy in 40 CFR part 60 regarding the definition of "modification." Under section 60.2, modification is defined as "any physical change in, or change in the method of operation of, an existing facility which increases the amount of any air pollutant (to which a standard applies) emitted into the atmosphere by that facility or which results in the emission of any air pollutant (to which a standard applies) into the atmosphere not previously emitted. Under that definition, any increase in emissions constitutes a modification. Under section 60.14(1), however, the definition of modification is "any physical or operational change to an existing facility which results in an increase in the emission rate to the atmosphere of any pollutant to which a standard applies shall be considered a modification within the meaning of section 111 of the Act." Under this definition, only an increase in the rate of emissions would be a modification. Commenter requested that EPA modify those two definitions so that they do not conflict with one another.
The commenters are directed to 40 CFR 60.14 which provides provisions for what constitutes a modification and provides some specific exemptions.
Commenter 0176 proposed adding the following definitions to section 60.4421 of the NSPS for new units and to the corresponding modified unit NSPS:
Market Dispatched Generation Resource (MDGR): An electric generation unit which participates within a Federal Energy Regulatory Commission (FERC) certified Independent System Operator (ISO) market or the Electric Reliability Council of Texas ISO market whereby the ISO makes unit commitment and dispatch decisions for the most efficient and reliable operation of all of the generation resources located and participating within the ISO.
Balancing Authority: The responsible entity that integrates resource plans ahead of time, maintains load-interchange-generation balance within a Balancing Authority Area, and supports Interconnection frequency in real time.
The EPA disagrees with the commenters and does not believe that these definitions should be added to the final rule as they do not provide any additional clarity in the provisions of the rule.
Commenter 0213 opposed EPA's proposed change to the definition of "potential electric output" to include the phrase "or the design net electric output efficiency" as an alternative to the default one-third efficiency value." 79 FR 34,972, 34,979-80. The commenter proposed eliminating applicability determinations based on capacity factors or efficiency values, instead imposing tiered emission limits based on a unit's annual hours of operation. This approach would obviate EPA's suggestion to include "net electric output efficiency" as an applicability determinant. In any event, the commenter stated that the Agency should not adopt this amendment, which would serve no purpose other than to exempt larger CTs from regulation that would otherwise have been covered under the rule. The commenter advocated the opposite approach: the rule's applicability provisions should be expanded to include all CTs that provide electricity to the grid.
This final rule adopts a modified version of the broad applicability approach we solicited comment on. The definition of potential electric output has been finalized to include the design efficiency of the unit. The primary impact of this is to impact the percentage electric sales threshold for non-base load and base load combustion turbines and not the general applicability. 
Commenter 0213 opposed EPA's proposed change to the definition of "net electric output" to include the phrase "of the thermal host facility or facilities," such that the proposed definition would read "... the gross electric sales to the utility power distribution system minus purchased power of the thermal host facility or facilities on a calendar year basis." 79 FR 34,972, 34,979-80 The purpose of this provision would be to allow third-party cogenerating units that provide useful heat output to adjacent plants under different ownership to reduce their gross electric sales figures by the amount of power purchased by the adjacent facility, and hence potentially avoid coverage under the rule. The commenter opposed this amendment for both the new source rule and modified/reconstructed rule. Id. at 34,979; see also 79 FR 1460. There is no legal or policy basis for allowing a cogenerating unit to reduce its annual electricity sales figure simply because it provides useful thermal output to adjacent unit under different ownership, and the commenter believes that a unit that provides or is designed to provide any amount of electricity for sale to the grid should be covered under the rule.
The intent of this final rule is to cover EGUs whose primary purpose is to sell electricity to the grid, not industrial units. Therefore, we are finalizing the applicability provision that net sales account for electricity used by thermal host facilities.
Commenter 0247 disagreed with EPA's proposed changes to the definition of "net-electric sales." EPA proposed to recognize the simultaneous purchase and sale issue, through the definition of "net-electric sales," but the proposal would add an additional proviso onto the definition of "net-electric output" in existing 40 CFR 60.41Da. Purchase of electricity needed to run the facility would only be subtracted out for those CHP facilities where "at least 20.0 percent of the total gross or net energy output consists of electric or direct mechanical output and at least 20.0 percent of the total gross or net energy output consists of useful thermal output."1 The commenter indicated that those criteria might be an appropriate way to identify facilities where cogeneration is a minimal aspect of the operation, or the unit is involved in "sham" cogeneration, but the appropriateness of ignoring the accounting fiction of simultaneous purchase and sales, which EPA has recognized repeatedly in the past, does not depend on, and should have nothing to do with, the relative percentages of electrical and thermal output realized by the CHP unit. The commenter recommended that the definition of "net-electric sales" should simply be stated as applying on a net basis to all CHP units, and EPA concerns about sham cogeneration should be addressed in the definition of "combined heat and power" or elsewhere in the rule.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs.
Commenter 0215 stated that EPA proposes numerous definitions in Subpart TTTT, some of which are similar (but not identical) to definitions in the corresponding provisions in proposed revisions to Subparts Da and KKKK, and to definitions in other subparts affecting EGUs. Proposed Applicability Text, Subpart TTTT section 60.5580, Subpart Da section 60.46Da(k), Subpart KKKK section 60.4421. The commenter felt that EPA should review its proposed definitions for consistency both between the proposed subparts and in other NSPS affecting EGUs.
The EPA thanks the commenter for their comment and has clarified that only subpart TTTT of part 60 will be finalized.
Request for Extension
Multiple commenters (0119, 0136, 0251) requested a 45-day extension of the comment deadline for the proposed rule for modified and reconstructed sources, identical to that granted for the existing source proposed rule. The commenters noted that the issues and comments on these two rules are interrelated, and thus it made sense for the proposed rules to have identical comment deadlines. Commenters noted that the two proposed rules were jointly released to the public and signed by the Administrator on June 2, 2014, and were both published in the Federal Register on June 18, 2014. In both proposed rules, EPA announced October 16, 2014 as the deadline for submitting comments. EPA extended the deadline for submitting comments on the existing source proposed rule until December 1, 2014, but did not extend the deadline for submitting comments on the modified and reconstructed source proposed rule. Commenters requested that EPA extend the deadline for submitting comments on the modified and reconstructed proposed rule to December 1, 2014.
The EPA offered for the modified and reconstructed 111(b) for EGUs a 120 day comment period through October 16, 2014 and held public hearings at 4 locations across the US the week of July 28, 2014. The EPA believes that was adequate time and outreach to generate comments on the proposal.
Multiple commenters (0089, 0092, 0114, 0115) requested a 90-day extension of the public comment period from October 16, 2014, to January 14, 2015 for both the existing source rule and modified/reconstructed source rule, both of which were published in the Federal Register on June 18, 2014. Commenters noted that EPA has uploaded to the docket a tremendous volume of information on its proposals, including the Federal Register preambles, Regulatory Impact Statements, Technical Support Documents, and over 600 additional documents. Commenters 0089 and 0092 stated that additional time was needed to understand and analyze this information than EPA had provided, including identifying and correcting errors in EPA's approach to establishing specific state goals. The commenters stated that EPA, the regulated community, and the public would benefit from a more thorough analysis, which would take many months rather than weeks. The commenters also noted that there is additional supporting information that EPA has yet to make available, and thus has not been analyzed, including detailed parsed files related to the IPM modeling. Commenter 0014 also mentioned EPA's requests for comments not only on the proposal but also on alternative "approaches," "scenarios," and "options," which the commenter said places an extraordinary burden on state agencies. 
Commenters 0089, 0092, and 0115 stated that EPA has proposed to regulate existing and modified/reconstructed EGUs in an unprecedentedly broad manner that would impact nearly every aspect of how electricity is generated, dispatched, transmitted, and used, and would create new EPA oversight over state authorities involved in these complex issues. Stakeholders need additional time to fully assess the enormous range of issues associated with such a program. Commenter 0115 argued that EPA had an obligation to ensure that the various stakeholders have an opportunity to adequately review the proposed rule.
The EPA offered for the modified and reconstructed 111(b) for EGUs a 120 day comment period through October 16, 2014 and held public hearings at 4 locations across the US the week of July 28, 2014. The EPA believes that was adequate time and outreach to generate comments on the proposal.
Commenter 0075 requested a 180-day extension of time to comments on the modified source proposal, stating that the current deadline of October 16, 2014 did not provide adequate time to review the proposed rule and supporting documentation and to develop meaningful comments and recommendations. The commenter noted that the modified source proposal was lengthy, consuming over 35 pages of the Federal Register. There are also dozens of supporting documents, a significant number of which contain technical information and data that must be reviewed and analyzed, not to mention the fact that many of the support documents were not issued until days after the modified source proposal was published in the Federal Register, allowing for even less time for review. Moreover, comments to EPA's even lengthier existing source proposal, which is supported by over 600 documents that must be reviewed and assessed, are also due on October 16, 2014. Preparing comprehensive and meaningful comments to both the modified source proposal and the existing source proposal by the current comment deadline is a virtual impossibility. Furthermore, the historical nature of the proposal (i.e., the fact that this is the first time that EPA has proposed to regulate CO2 emissions from modified and reconstructed power plants), in and of itself justifies an extension of time to comment on the modified source proposal.
This commenter appears to the referencing the proposed Clean Power Plan Emission Guidelines for Existing Electric Generating Units.  The docket for this rulemaking contains all relevant supporting information. Additionally, the EPA offered for the modified and reconstructed 111(b) for EGUs a 120 day comment period through October 16, 2014 and held public hearings at 4 locations across the US the week of July 28, 2014. The EPA believes that was adequate time and outreach to generate comments on the proposal.
Commenter 0263, 0254 requested that EPA provide opportunity for further public evaluation and comment on this proposal as well as the proposed section 111(d) guidelines and NSPS. The commenter stated that, due to the quantity of requests for comment and the level of detail on which EPA is seeking comment, this proposal more resembles an advanced notice of proposed rulemaking. In addition to the proposal's premature condition, there is heightened public interest on all three proposals. The commenter anticipated that EPA would receive extensive comments and data which could influence and change the promulgated final rule. Moreover, the interdependence described above for all three rule proposals does not allow them to be severable. Fundamental pieces of these rules are dependent on each other. A decision made for one rule likely will have consequences in another.
The EPA offered for the modified and reconstructed 111(b) for EGUs a 120 day comment period through October 16, 2014 and held public hearings at 4 locations across the US the week of July 28, 2014. The EPA believes that was adequate time and outreach to generate comments on the proposal.
Commenter 0116 argued that, in light of clear violations of section 307, EPA should withdraw the modified sources rule immediately. The commenter noted that the comment deadline on the rule was October 16, 2014 and was thus fast approaching. If EPA wished to press forward with the modified sources rule, the commenter requested that EPA should withdraw that rule and re-propose it with all the supporting documents and data required by section 307. The commenter requested that EPA should then provide 120 days from the re-proposal date to provide sufficient time for states and the public to review and comment. Alternatively, the commenter said EPA should--at a minimum--publish the missing data immediately and then extend the comment period 120 days from the date of such publication.
This commenter appears to the referencing the proposed Clean Power Plan Emission Guidelines for Existing Electric Generating Units.  The docket for this rulemaking contains all relevant supporting information. Additionally, the EPA offered for the modified and reconstructed 111(b) for EGUs a 120 day comment period through October 16, 2014 and held public hearings at 4 locations across the US the week of July 28, 2014. The EPA believes that was adequate time and outreach to generate comments on the proposal.
Commenter 0192 urged EPA to reopen the comment period on this rulemaking so that it can be realigned with the comment deadline for EPA's concurrent rulemaking for existing fossil fuel-fired EGUs under Section 111(d). The commenter stated that under EPA's approach, its proposed rulemakings for modified and reconstructed sources is inextricably tied to its proposed rulemaking for existing sources. Both were proposed and published on the same date and, in many respects, rely on the same underlying data.
The EPA offered for the modified and reconstructed 111(b) for EGUs a 120 day comment period through October 16, 2014 and held public hearings at 4 locations across the US the week of July 28, 2014. The EPA believes that was adequate time and outreach to generate comments on the proposal.
Incorporation by Reference
Multiple commenters (0145, 0172, 0189, 0193, 0211, 0237, 0244, 0260, 0270, 0282) incorporated by reference their public comments on the January 2014 proposed rule for new units. Commenters noted that the proposed rule for modified and reconstructed units included many elements of the January 2014 proposal for new units, and as such they have already submitted many of their technical comments on this proposed rule in the comments they filed on the January 2014 proposal for new units. They indicated they would refer to relevant portions of their comments on the January 2014 proposal when making similar points on this proposed rule. Commenter 0172 also noted that both rules have the same cornerstones, including EPA's 2009 Endangerment Finding, and EPA's annual GHG emissions inventories, which inventories are prepared by EPA in accordance with IPCC's internationally accepted guidelines (2006). 
Several commenters mentioned specific comments on the January 2014 proposal that are also relevant to this proposal. Commenter 0145 incorporated by reference their comment on why simple cycle turbines should be exempt from the rule. Commenter 0282 pointed to their comment that EPA's proposed exemptions to the section 111(b) standard were capricious, irrational and unjustified. Commenter 0270 objected to EPA's failure to account for the effect of SSM events on the achievability of the proposed standards. Commenter 0193 emphasized the many significant changes affecting the utility industry, including most notably the increasing demand for highly efficient simple cycle turbines to support the growth in renewable power generation. Commenter 0193 also noted the concern by many commenters over the long-term in-use feasibility of the proposed emission standards and the appropriateness of the proposed cut-point between large and small stationary combustion turbines. Commenter 0193 supported EPA's decision to revisit these important issues in this rulemaking. Commenter 0244 requested that EPA, in keeping with the proposed new source standard, designate efficient generation technology with partial CCS as BSER for reconstructed steam EGUs and impose a performance standard at least as stringent as 1,200 lbs CO2/MWh on a net output basis. Commenter 0260 specifically noted their comments on (1) EPA's proposed monitoring requirements; (2) EPA's proposed continuous compliance requirements, including the proposal that compliance with the mass emissions rate limits be determined on a 12-operating-month rolling average basis; and (3) EPA's proposed notification, recordkeeping and reporting requirements.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0222 preemptively incorporated by reference their impending comments on the June 2014 existing source guidelines, stating that this proposal is inextricably linked with EPA's other proposal to regulate CO2 emissions from existing EGUs. While the commenter appreciated the additional time to comment on EPA's existing source rule proposal, bifurcating comment on the rulemaking did not make sense.
The EPA thanks the commenter for their comment and EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Multiple commenters (0142, 0183, 0214) incorporated by reference their comments on both the January 2014 new source rule and June 2014 existing source guidelines, noting the interrelated nature of the two rules. Commenter 0214 argued that because EPA has illegally attempted to regulate modified and reconstructed units as both "new sources" and "existing sources" simultaneously, this proposal is inextricably linked with EPA's other two proposals regarding fossil fuel-fired EGUs under section 111. The commenter noted that EPA has, in fact, specifically requested certain comments that directly relate to the other two proposals. The commenter noted that they already commented on the significant legal and technical flaws associated with EPA's January 2014 proposed new source rule and planned to submit similarly critical comments on EPA's proposed guidelines when due (December 1, 2014), and thus would not repeat those comments here. The commenter noted, however, that some of the same comments are directly relevant in this rulemaking because the correction of the flaws in EPA's other section 111 proposal would also address many of their concerns with the Agency's modified/reconstructed proposal. In particular, the commenter stated that EPA has proposed section 111(d) existing source emission guidelines that would require a complete restructuring of the electric power system as a whole, instead of imposing requirements that only apply to the affected facilities subject to section 111(d). The commenter said the unprecedented breadth of the section 111(d) proposed guidelines thus raises significant concerns regarding EPA's treatment of modified and reconstructed sources.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
The public comments submitted by Utility Air Regulatory Group (UARG) regarding the proposed rule for modified/reconstructed units were incorporated by reference by multiple commenters. Some commenters (0146, 0150, 0157, 0173) cited UARG alone, while others (0152, 0156, 0158, 0177, 0183, 0201, 0203, 0227, 0229, 0236, 0239, 0241, 0248, 0254, 0275) cited UARG along with one or more of the following organizations: the Edison Electric Institute (EEI), National Rural Electric Cooperative Association (NRECA), Class of '85, Coal Utilization Research Council (CURC), Gulf Coast Lignite Coalition (GCLC), Arizona Utilities Group (AUG), National Association of Manufacturers (NAM), National Mining Association (NMA), American Public Power Association (APPA), Electric Power Research Institute (EPRI), Florida Electric Power Coordinating Group (FCG), Florida Municipal Electric Association (FMEA), and other industry organizations. 
Commenter 0183 agreed with those who urged EPA to withdraw all three proposals (new, modified/reconstructed, and existing source rules) and, to the extent EPA further pursues GHG regulations, to work at the outset with the affected utilities to develop rules that are within the authority of the CAA, technically feasible, and capable of implementation without threatening the reliability and cost effectiveness of energy in Texas and across the United States.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
The public comments submitted by the National Rural Electric Cooperative Association (NRECA) regarding the proposed rule for modified/reconstructed units were incorporated by reference by multiple commenters. Some commenters (0145, 0153, 0161, 0176, 0243, 0278) cited NRECA alone, while others (0152, 0179, 0191, 0203, 0254, 0275) cited NRECA along with one or more of the following organizations: Utility Air Regulatory Group (UARG), Edison Electric Institute (EEI), Class of '85, Gulf Coast Lignite Coalition (GCLC), Arizona Utilities Group (AUG), Florida Electric Power Coordinating Group (FCG), and Florida Municipal Electric Association (FMEA).
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
The public comments submitted by the Edison Electric Institute (EEI) regarding the proposed rule for modified/reconstructed units were incorporated by reference by multiple commenters. Some commenters (0162, 0250) cited EEI alone, while others (0152, 0156, 0158, 0171, 0177, 0189, 0227, 0229, 0239, 0248) cited NRECA along with one or more of the following organizations: Utility Air Regulatory Group (UARG), National Rural Electric Cooperative Association (NRECA), Class of '85, Coal Utilization Research Council (CURC), North Dakota Lignite Energy Council (LEC), Arizona Utilities Group (AUG), and other industry organizations.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
A variety of commenters incorporated by reference the public comments submitted by other organizations on the proposed rule for modified/reconstructed units. Commenters 0155 and 0228/0273 supported the public comments submitted by the Tri-State Generation and Transmission Association, Inc. and incorporated by reference Tri-State's comments addressing legal, technical, economic, and practical concerns raised by EPA's proposal. 
Commenter 0212 supported the Gas Turbine Association's (GTA's) recommendation to exempt combined heat and power units to promote the deployment of this highly efficient technology, while commenter 0193 supported the GTA's recommended value of 1,500 MMBtu/h (HHV) as the appropriate cut-point between large and small turbines for both the new and modified and reconstruction proposed rulemakings.
Commenters 0144 and 0209 supported and incorporated by reference the comments submitted by the American Public Power Association (APPA). Commenter 0209 noted that the APPA had prepared a valuable analysis of the proposed rule and provided legal insight that was not duplicated by the commenter in their public comments on the proposed rule. 
Commenter 0274 incorporated by reference the comments submitted by the National Mining Association (NMA), while commenter 0196 incorporated by reference the comments submitted by a broad industry coalition (the "Coalition"). Commenter 0180 supported and joined in the detailed comments submitted by a coalition of industry associations ("the Associations"), as well as the SSM Coalition. Commenter 0280 joined in the comments submitted by Sierra Club, Environmental Defense Fund (EDF), Natural Resources Defense Council (NRDC), and Earthjustice ("Joint Environmental Comments").
Commenter 0247 joined with numerous other trade associations and business organizations filing joint comments on the modified/reconstructed sources proposal, and incorporated those comments by reference. Commenter 0232 incorporated by reference all prior written and oral testimony and submissions to the Agency in this matter, including all citations and attachments, as well as all of the documents cited in and attached to their comments, as part of the administrative record in this action, Docket ID No. EPA-HQ-OAR-2013-0603.
Commenter 0290 submitted a late comment in which they supported the National Rural Electric Cooperative Association (NRECA) and the Class of '85 Regulatory Response Group.  
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Net or Gross MW Output
In the proposal for modified/reconstructed sources, EPA proposed net output-based emission limits for utility boilers and IGCC units, and requested comment on whether to use either gross or adjusted gross output-based standards in the final rule. EPA also proposed gross output-based emission limits for NGCC turbines, and requested comment on whether to use a net output-based approach in the final rule. Multiple commenters (0144, 0145, 0152, 0157, 0171, 0178, 0183, 0193, 0197, 0203, 0214, 0226, 0245, 0260) supported gross output-based standards, rather than net output-based standards, for all unit types. 
Gross energy output includes the gross electric or mechanical output from the affected facility minus any electricity used to power the feedwater pumps plus 75 percent of the useful thermal output. Net energy output includes the net electric or mechanical output from the affected facility plus 75 percent of the useful thermal output, where net electric output is the amount of gross generation minus the electricity used to operate the plant (i.e., auxiliary loads); such uses include fuel handling equipment, pumps, fans, pollution control equipment, other electricity needs, and transformer losses. See Memorandum from U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards to EGU NSPS Docket (EPA-HQ-OAR-2013-0603), Amended Regulatory Text (Proposed Applicability). June 2014.
Multiple commenters (0171, 0178, 0260) argued that EPA had offered no justification for treating modified and reconstructed fossil fuel boilers and IGCC units differently than newly constructed units. The commenters noted that EPA had proposed standards for modified and reconstructed boilers and IGCC units as net output emission rates, while proposing standards for newly constructed units as gross output emission rates.
Commenter 0157 argued that EPA had not justified the dichotomy in standards in the modified/reconstructed rule--proposing a net output standard for coal-fired units and a gross output standard for natural gas-fired combustion turbines. The commenter stated that it appeared to be explicitly designed to favor natural gas at the expense of coal. The commenter argued that EPA should remain focused on technology rather than fuel choices.
In supporting the use of gross output standards, commenter 0193 stated that gross output standards are fairer and more reliable than net output standards to measure emissions and compliance. Moreover, the proposed use of periodic fuel sampling as an acceptable monitoring method provides appropriate compliance assurance. Determining the net output of an EGU is complicated and prone to errors.
Commenter 0214 stated that the use of gross output allows the plant operator to account for electrical, mechanical, and thermal energy use by the plant, giving operators the needed flexibility to design systems in the most efficient and economic manner. Gross MWh output is also straightforward, simple, consistent, and directly measured. Furthermore, market drivers will continue to ensure that power producers operate efficiently because utilities have a strong incentive to ensure the gap between gross and net output is as small as possible, maximizing the return on investment. Commenter 0226 stated that it is sensible to consider all of a unit's inside-the-fence options for efficiency improvement. 
Commenter 183 stated that due to the various emission controls that could be installed on a unit, the commenter believes the best measure of heat rate uses gross heat rate; otherwise, units heavily controlled by emission systems are penalized by their degraded heat rate (when measured on a net basis) due to comparatively greater auxiliary loads. 
Commenter 0197 stated that a gross output-based standard is more appropriate than the net output-based standard because well-controlled fossil fuel-fired EGUs consume more energy to operate air pollution control devices (i.e., scrubbers, selective catalytic reduction devices, and particulate controls) than uncontrolled units. The gross output-based standards are appropriate for both new and existing fossil fuel-fired EGUs. The commenter stated that the definition of gross output should allow for 100 percent of the useful thermal energy being produced and used to be included, as opposed to 75 percent of useful thermal energy being produced as proposed. The commenter recommended that, regardless of whether the final rule uses a gross output or net output-based standard, 100 percent of the useful thermal energy should be credited.
Multiple commenters (0157, 0171, 0178, 0214, 0260) noted that a gross output-based standard is also consistent with the monitoring and reporting requirements under 40 CFR part 75 and with other programs (e.g., Acid Rain program), which already rely on gross megawatt data. Commenter 0245 indicated that using a gross output-based standard would avoid sending conflicting reports to the same agency. The commenter indicated it would also avoid factoring in the added parasitic loads from emissions control retrofits, avoiding potential future NSPS modification issues.
Multiple commenters (0144, 0145, 0171, 0178, 0203, 0214, 0260) argued that net-based standards are not appropriate for modified and reconstructed EGUs. Some commenters (0171, 0178, 0203, 0260) noted that pollution control technology often imposes significant parasitic load requirements on an EGU. If EPA were to adopt a standard that was calculated on a net basis, that level would need to be even higher to account for parasitic load. However, given the potential range of control options and corresponding parasitic load requirements, arriving at such a standard would be impractical and would not further the objective of the proposal.
Commenter 0203 argued that EPA should base its prescribed standards on an analysis that examines those standards in the context of source category achievability, with performance adequately demonstrated considering costs, energy and non-air health impacts, i.e., by conducting an appropriate inquiry into the correct standard(s) of performance. Stated another way, EPA should base net output standards on net output analyses, and gross output standards on gross output analyses, avoiding a mixing of the two very different measures of emissions. Such an approach decreases the likelihood of an arbitrary rulemaking. Therefore, as the Agency proceeds forward with this rulemaking, gross output-based standards should be used for both categories of EGUs (boilers and turbines).
Commenter 0203 noted that heat rate improvement projects--which EPA seeks to require in its NSPS proposals, may trigger NSR review, as the pollution control exclusion no longer applies to NSR review (the exclusion is still available for purposes of NSPS review). If so, remaining coal-fired units could have emissions for purposes of NSR evaluated on a net utilization basis, which would not (unfairly so) include parasitic loads caused by increased pollution controls. The commenter stated that EPA did not address this concern in the proposal and argued that EPA should not exacerbate it by using net output standards for utility boilers and IGCC units.
Commenter 0214 noted that net MWh output is facility-specific and difficult to accurately calculate. For example, many facilities have transformers that support multiple units at the facility, making unit-level reporting difficult. More importantly, station electric services may come from other outside sources to supply lighting, well pumps, and other ancillary loads. Additionally, some station services are dedicated per unit, while other station services may be measured at a facility level. Examples of facility-wide equipment that often serve more than one unit include coal handling equipment such as unloaders and conveyors, electric fire pumps, cooling tower makeup pumps, and pollution control equipment (e.g., FGD and baghouses). Accurately measuring and reporting all of these sources would require complex calculations and would naturally lead to variations among affected sources as well as inconsistencies in both reporting CO2 emission rates and complying with the proposed CO2 standard. The commenter said a net output-based standard would also discourage the deployment of technologies that could successfully reduce CO2 emissions at a lower cost, such as CHP and co-generation.
Commenter 0145 noted that, as currently proposed, utility boilers and IGCC units must demonstrate compliance with the applicable CO2 emissions/MWh standard based on the gross CO2 emissions from the affected facility divided by the facility's net energy output. Under this methodology, electricity that is generated by the affected facility but used to operate plant equipment such as pumps, fans and pollution control equipment is not used in determining compliance with the standards, notwithstanding the fact that the CO2 emissions associated with the generation of this electricity is included in the compliance calculation. The commenter said this would result in a calculated emission rate that is artificially high. This would be particularly problematic for affected facilities that have installed advanced pollution control systems that have large power demands. These facilities, which typically have installed controls under other CAA programs such as Regional Haze or the New Source Review Program, would have a more difficult time meeting the standards than similar uncontrolled facilities. To address this and have a compliance demonstration that accurately measures an affected facilities actual CO2 emission rate, the commenter said the final rule should base compliance for utility boilers and IGCC units on a gross emissions-gross energy output basis.
Commenter 0144 noted that, while EPA stated it was proposing net output CO2 emission rates, throughout the rule gross output was discussed. For example, EPA explained that the rule would require monitoring of "gross output," expressed in MWh. EPA also stated that part 75 monitoring systems used together with the "gross output" over a period of 12 months (a rolling average updated after each new operating month) would be used to calculate the average CO2 mass emissions rate. Further, initial compliance would be calculated by dividing the sum of the hourly CO2 mass emissions values by the total "gross output." In addition, recordkeeping requirements would require owners or operators to keep records of the calculations performed to determine the total CO2 mass emissions and gross output for each operating month. Commenter 0144 argued that this net output-based reporting compliance alternative should be rejected. As EPA had already noted in the section 111(b) rulemaking, the only data available on CO2 emissions from EGUs currently is in the form of gross output from CEMS, and thus requiring reporting on a net output basis would be inconsistent with the current requirements, would add unwarranted costs and burden to utility reporting, and also "would have little impact...in terms of environmental performance." Thus, the commenter questioned why EPA was even requesting comment in this regard.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenters 0169 and 0242 recommended that EPA develop a consistent standard (gross or net output-based) across all unit types, amongst all three proposed rules to minimize the collection of data in accordance with Paperwork Reduction Act (44 U.S.C. 3501 et seq.). Commenter 0169 noted that EPA proposed a gross-output approach in the NSPS rulemaking, proposed a net-output approach in the ESPS rulemaking, and proposed a net-output based approach for fossil fuel-fired boilers and IGCC units in the modified/reconstructed source rule but requested comment on using a gross-output approach. In addition, commenter 0242 noted that EPA proposed gross output-based standards for modified/reconstructed natural gas-fired stationary combustion turbines to be consistent with standards for newly constructed units as proposed in January 2014, but requested comment on whether the form of the standard should be set on a net-output basis. The EPA stated that both rules, the modified/reconstructed source rule and new source rule, would take the same approach once finalized. 
Commenter 0169 argued that EPA's intermixing of gross and net throughout this rule and the rest of the CPP makes it very difficult for sources to uniformly demonstrate heat rate amongst the rules. Furthermore, EPA's intermixing of gross and net throughout this proposed rule brings into question whether the BSER determinations reviewed are based on gross or net data and whether the emission rates reviewed are actually gross emission rates for the best plants since the rates proposed are only achievable if these were based on gross emission rates. In addition, the requirements in the modified source rule that require collection of both gross and net-based data are unnecessarily burdensome.
Commenter 0242 believes that if net output is the basis of the standard, then EPA should include a mechanism to account for and credit the parasitic load that is inherent to the operation of environmental control devices, which provide environmentally desirable benefits, if EPA chooses to continue to pursue the section 111(b) and 111(d) rulemakings.
The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
Commenter 0241 supported net output-based standards. The commenter noted that the proposed CO2 emissions limits for the utility boiler and IGCC category are expressed in units of mass of CO2 per unit of net energy output, specifically in lb CO2/MWh-net. The proposed CO2 emissions limits for natural gas-fired stationary combustion turbines are expressed in units of mass of CO2 per unit of gross energy output, specifically in lb CO2/MWh-gross. The EPA solicited comment on whether a net-output based approach should be used for the natural gas-fired units. Commenter 0241 suggested that the EPA be consistent in its approach and use net output for all units, since this is more characteristic of the unit's actual operation.
 The EPA points the commenter to the Response-to-Comment (RTC) document for 111(b) newly constructed EGUs and to the preamble for more detailed discussion on this comment. Both documents are available in the rulemaking dockets.
