November 13, 2014 1



### Discussion Paper on Potential Implementation of Alt ernative Monitoring under the GHGRP

I. Overview
In October 2009, the Environmental Protection Agenc y (EPA) created the Greenhouse Gas Reporting Program (GHGRP) by issuing the Greenhouse Gas Reporting Rule (40 CFR Part 98). The GHGRP requires facility-level annual reporting of greenhouse gases for large direct emitters and suppliers in over 40 industrial sectors in the United States. The program includes specific monitoring methods for processes and process equipm ent in order for facilities to calculate greenhouse gas (GHG) emissions in a consistent mann er. In certain cases, the program allows the use of alternative methods. During implementation of the GHGRP, the EPA has rec eived requests to allow additional flexibility to accommodate the optional use of nove l monitoring methods. For example, several environmental groups petitioned the EPA for advance d, innovative monitoring methods to be allowed under subpart W, which covers Petroleum and Natural Gas Systems. 1 These requests stem from advances in technology that could improve the quality of the data submitted and potentially reduce the burden on regulated faciliti es who are using these advanced methods. With regard to subpart W, as oil and gas operations seek to capitalize on advances in measurement and monitoring technology in optimizing process operations and reducing fugitive emissions from process equipment leaks, opportuniti es could arise for facilities to use innovative technologies to gather emissions data. The EPA is assessing the potential opportunities fo r the optional use of innovative measurement or monitoring technologies to calculate emissions f rom affected sources under subpart W and other areas of the GHGRP. The EPA’s goal for this a ssessment is to determine if the optional use of such technologies could be applied to the GHGRP to improve the overall accuracy and transparency of reported data in a cost-effective w ay while still meeting the overall objectives of Part 98. The EPA is requesting comment on the feasi bility, possible regulatory approaches and provisions necessary to allow the optional use of a dvanced measurement or monitoring methods in the GHGRP, and methods to ensure compliance with those provisions in an efficient manner. In particular, as described in Section IV of this d ocument, the EPA is soliciting data and case studies that could provide information regarding th e benefits, costs, and other potential considerations. This paper discusses approved uses of alternative m ethods under the GHGRP and considerations for expanding voluntary use of advanced monitoring methods (described in this document as “alternative monitoring”) to subpart W and other su bparts of the program. The EPA is soliciting input on the ideas in this di scussion paper. Following review of the comments received, the EPA may propose amendments r elated to the use of alternative innovative technologies in GHGRP monitoring in a fu ture rulemaking.

1 Petition for Rulemaking and Interpretive Guidance Ensuring Comprehensive Coverage of Methane Sources under Subpart W of the Greenhouse Gas Reporting Rule – Pe troleum and Natural Gas Systems. March 19, 2013. ( http://www2.epa.gov/sites/production/files/document s/ghgrp_petition_0.pdf )2



### II. Background
In the GHGRP, each subpart specifies the monitoring requirements for the specific types of processes and units used in that industry. These mo nitoring requirements can include direct emissions measurement, facility-specific engineerin g calculations, and emission factors derived from direct measurement. Monitoring in the GHGRP ge nerally includes requirements regarding which parameters to monitor, the type of monitoring device(s) that can be used, the precision and accuracy requirements for the monitoring device, th e calibration requirements to be conducted periodically, the frequency of monitoring, and the reference test method to be used. For a few subparts, the EPA has already incorporate d the option to use alternative monitoring. In particular, in 2009, the Greenhouse Gas Reporting R ule was written to mainly allow alternative monitoring for subpart E (Adipic Acid Production) a nd subpart V (Nitric Acid Production) to allow for use of continuous emissions monitoring sy stems (CEMS) for N 2 O emissions. At that time the EPA was aware of a few facilities that wer e using CEMS to monitor N 2 O emissions; however, unlike CEMS for CO 2 , there was no standard test method for certifying a CEMS for N 2 O emissions that the rule could reference. In order to allow these facilities to comply with the rule while using a non-standard monitoring system, the GHGRP has provided a way to apply and receive approval for its use. For subparts E and V

, facilities must apply for approval to use alternat ive monitoring by January 30 th of the applicable reporting year (RY) using a stan dardized application form. The application requires the facility to include details on the fac ility, the unit name and type, the alternative method to be used, a justification for using the al ternative method, as well as some additional supplemental information. Once the applications ar e received, they go through a standardized technical review. Under subpart E, one facility has requested an alte rnative monitoring method for each year of the GHGRP (RY2010 through RY2014). Under subpart V, the re have been varying numbers of applications per reporting year. Four reporters app lied for RY2014. All applications submitted for subpart E and subpart V thus far have been appr oved. The provisions of subpart I (Electronics Manufactur ing) allow reporters to request approval to use an alternative stack test method or to use an a lternative method to determine abatement system destruction or removal efficiency (DRE). For subpart I, an alternative method is described as “any method of sampling and analyzing for a fluorinated GHG or N 2 O, for the determination of parameters other than concentratio n, for example, flow measurements, that is not a method specified in this subpart and that has been demonstrated to the Administrator’s satisfaction, using Method 301 in appendix A of par t 63, to produce results adequate for the Administrator’s determination that it may be used i n place of a method specified elsewhere in this subpart”. In order to use an alternative metho d for subpart I, reporters must notify the EPA Administrator (or authorized representative) of the intent to use an alternative method. The notification must include information on a test pla n, the validation of the method using EPA Method 301, and the rationale for not using the met hod specified in the GHGRP. If the EPA approves the alternative method test pla n for subpart I and the reporter completes the test plan, the reporter must then report the result s of the alternative method test plan to the Administrator for review and approval. The Adminis trator may then either dispute the results of the test plan or approve the alternative method for use in Subpart I. Once an alternative method has been approved in subpart I, that same method ma y be used at any other facility for the same3

fluorinated GHGs and types of stack or abatement sy stems, as applicable, provided that approved conditions in the test plan also apply to the facil ity in question. These provisions went into effect January 1, 2014. As of July 2014, no alternative method applications had been submitted or approved for sub part I. There are other EPA programs that also allow for th e use of alternative monitoring and/or alternative test methods including other Clean Air Act and Clean Water Act programs. See Appendix A for additional details on alternative mo nitoring provisions in some other EPA
programs. In general, the alternative monitoring allowed unde r these other programs requires one or more of the following elements:

• Detailed applications;

• Demonstration that the results of the alternative m onitoring approach are comparable in quality to the methods in the specific rule subpart s; and

• Specific approval from the EPA for a facility to us e the method.



### III. Examples of Alternative Monitoring that Could Potentially Be Allowed under Subpart W
The issue of alternative monitoring was revisited i n March 2013 when, as mentioned in Section I, a group of environmental organizations submitted a petition for rulemaking related to methane emissions from subpart W (Petroleum and Natural Gas Systems). This petition asserts that new and innovative technologies exist today that are be ing employed by select companies or facilities in the oil and natural gas sector and that the data from these technologies may provide enhanced or more accurate data than current GHGRP methods. A ccording to the petitioners, real-time continuous emissions monitoring technologies are ev olving and, by including advanced innovative monitoring methods, the GHGRP could acce lerate the development and use of these technologies, especially with respect to methane em issions. Several advanced technologies could potentially be applied to petroleum and natural gas systems. A few examples are briefly described below

. Greenhouse gases like CO 2 and methane each absorb a unique and characteristi c near-infrared wavelength. Tunable diode lasers and laser absorpti on spectroscopy exploit this property by using laser light tuned to a specific mid-infrared wavelength to measure the concentration of a specific gas like methane in ambient air. Cavity r ing-down spectroscopy (CRDS) is a tunable diode laser absorption spectroscopy technique that simultaneously detects gas emissions and measures the concentration. A single frequency lase r is aimed into a cavity created by two or more high reflectivity mirrors. Laser light bounce s between the mirrors thousands of times, the laser is turned off and the light intensity inside the cavity steadily decays to zero (the “ring down”). If a gas is present in the cavity that abs orbs the frequency of the laser light, the ring down time accelerates due to absorption by the gas. CRDS achieves sensitivity by creating a very4

long path length for the laser light, significantly enhancing the signal and reducing noise. 2, 3 Cavity ring-down spectroscopy could be used in oil and gas applications and is applicable to both fixed continuous emissions monitoring and to m obile monitoring applications. Recent advances in optical remote sensing (ORS) tec hnology offer the capability to provide measurements of methane and other gases in ambient air. 4 An example of one such advanced ORS system is differential absorption lidar (DIAL), an open path ORS technology that uses an active laser source tuned for a target gas such as methane or CO 2 , and detects the differential signal returned when the laser light is absorbed by the target gas in the atmosphere. DIAL systems can quickly scan a vertical plane downwind of an emission source and rapidly generate a profile of gas concentration as a function of heigh t and distance. Instantaneous meteorological data can be incorporated with the emissions for rea l time computation of mass emissions flux. Detection limits for methane are sensitive to atmos pheric conditions and path length but are in the range of parts per billion. 5, 6
For certain subpart W sources, emissions are calcul ated using emission factors or engineering calculations. For example, subpart W emissions fro m natural gas pneumatic devices are calculated using emission factors. The number of p neumatic devices in each facility are counted according to type - low continuous bleed, high cont inuous bleed, and intermittent bleed - and the device count is multiplied by a published subpart W emission factor identified for pneumatic devices for each particular natural gas industry se gment. Innovative monitoring approaches could be applied to provide direct measurement or t o develop facility-specific emission factors in cases where industry segment emission factors are p rovided by the rule. In the pneumatic device example, an operator might directly measure emissio ns from pneumatic devices. It is important to note that alternative monitoring , as discussed in this paper, is not the same as provisions for “best available monitoring methods,” or BAMM, which were included in the GHGRP in 2009 but have since been removed from the GHGRP except for select, short-term monitoring provisions. While Part 98 allowed the us e of BAMM in the early stages of implementation of the GHGRP for all reporters and f or several years for certain subparts, the use of BAMM has been phased out for all industry-specif ic subparts, and the EPA does not intend to reintroduce this concept as part of this alternativ e monitoring discussion. BAMM was meant as a temporary allowance for those f acilities that could not immediately implement the subpart-specific monitoring required, either due to equipment availability or technical installation issues that required additio nal time to resolve. While BAMM was intended to include monitoring that may have been less strin gent than the GHGRP requirements, the purpose of alternative monitoring is to allow for a dvanced monitoring, flexibility, and innovation while improving data quality.

2 Wheeler, M. D., S. M. Newman, et al., 1998, Cavity ring-down spectroscopy. J. Chem. Soc., Faraday Trans. 94(3): 337-351.
3 Cavity Ring Down Spectroscopy (CRDS) ; www.picarro.com/technology/cavity_ring_down_spect roscopy 4 Allen, D.T. et al. Measurements of methane emissio ns at natural gas production sites in the United St ates, Proceedings of the National Academy of Sciences of the United States o f America, 110(44): 17768–17773, 2013.
5 Whetstone, J., Maxwell , S.E., and others, Differential Absorption LIDAR for Greenhouse Gas Me asurements , presentation at Council for Optical Radiation Measurements Annual Technical Conference, May 30 – June 1, 2012, Ottawa , Canada.
6 Jones, D., The Application of Differential Absorption Lidar ( DIAL) for Methane Monitoring, National Physics Labo ratory, U.K., presentation, September 4, 2014, www.npl.co.uk5



### IV. Request for Input
The EPA is seeking input on the ideas and content o f this discussion paper, including whether the EPA should allow the use of alternative monitor ing in the GHGRP. If so, the Agency seeks input on whether the current approaches used in the GHGRP are appropriate and could be applied more broadly or if there are other programs that might serve as an appropriate model. The EPA also seeks input on what criteria should be considered as part of the Agency’s evaluation. In evaluating whether and how to incor porate voluntary use of alternative methods, there could be several considerations including:

• Impact on emissions reporting and quality of data;

• Impact on the EPA’s ability to effectively verify a nd evaluate data received;

• Impact on the public’s ability to analyze data acro ss facilities;

• Impact on facility and/or EPA burden;

• Ease of implementation;

• Extent to which opportunities are created and innov ation encouraged;

• Consistency, equity of treatment among reporters in a subpart or across subparts; and

• Comparability of data between reporting years;

In addition to the criteria the EPA should consider , the EPA seeks input on several implementation questions that are likely to be rais ed if the EPA proposes to allow alternative monitoring. There are several approaches the EPA co uld consider that raise multi-faceted implementation questions including, but not limited to, the following:

• How should a facility let EPA know they want to use alternative monitoring? What information should be provided? Should this notifi cation be required annually? How should EPA provide notification of approval or disa pproval?

• Who could use alternative monitoring? Should only c ertain subparts be allowed to use it? Should there be an emissions threshold?

• For which parameters could alternative monitoring b e used? Should every monitoring change be allowed or only significant changes? Shou ld changes to emission calculations be allowed?

• Should a facility be required to prove that its alt ernative monitoring approach results in higher data quality? If yes, how should this be ac complished?

• Should EPA maintain a list of approved alternative monitoring methods? Should an alternative monitoring method approved for use at o ne facility be eligible for application at another facility in the subpart or across other subparts? Feedback on these questions will help the EPA consi der possible options for designing alternative monitoring approaches. Appendix B outlines three illustrative examples of how the use of alternative monitoring could be applied to the GHGRP. The first example approac h is a detailed annual request for use of alternative monitoring which could be possible for any parameter in any subpart. The second6

example approach entails a one-time detailed reques t which could be limited to only certain subparts. In the third example approach, the EPA c ould publish a list of monitoring technologies that are considered alternative and innovative. A facility could submit a one-time indication to use this technology for an applicable subpart. Thes e examples are for illustrative purposes only, the EPA welcomes comments on whether these or other approaches would be appropriate. Following review of the comments received on this d iscussion paper, the EPA may propose amendments related to the use of alternative innova tive technologies in reporting to the GHGRP in a future rulemaking.7



### Appendix A
Alternative Monitoring in Other EPA Programs

A. Clean Air Act New Source Performance Standards and National Emission Standards for Hazardous Air Pollutants The EPA’s Office of Air Quality Planning and Standa rds (OAQPS) allows the use of alternative monitoring and/or alternative performance testing u nder the New Source Performance Standards (Title 40, Part 60) and the National Emissions Stan dards for Hazardous Air Pollutants (Title 40, Part 61 and Part 63) of the Clean Air Act. Review a nd approval of requests are run through the EPA’s Emission Measurement Center (EMC). Approval of alternative monitoring must allow the A dministrator to make adequate determination of compliance. In addition, new appr ovals should be consistent with prior approvals. Examples of approvable alternative monit oring are included in §§60.13(l), 61.14(g), and 63.8(f). For alternative test methods, approval requires tha t the test method produce results adequate for the Administrator’s determination of compliance and that it has been demonstrated to the Administrator’s satisfaction using Method 301 of Ap pendix A, Title 40 Part 63. More detailed information about the EMC including l inks to methods and monitoring for NSPS and NESHAP may be found at www.epa.gov/ttn/emc/index.html

.

B. Clean Water Act Alternative Test Procedure Prog ram The Clean Water Act (CWA) offers flexibility to mod ify methods under 40 CFR Part 136. The Clean Water Act Alternate Test Procedure (ATP) allo ws a method developer to ask for review (not approval) of the following:

• Method using a determinative technique (e.g., a pol lutant detector) different from that in an existing Part 136 method, or

• Modification to a Part 136 method that falls outsid e the scope of the modification flexibility described in the Part 136 method, or at 40 CFR 136.6. The language at 40 CFR 136.6 offers flexibility to modify approved methods without EPA review. The applicants must establish equivalent pe rformance as defined in 136.6(b)(2)(i) and must document the modified method in a write-up or addendum as described in 136.6(b)(2)(ii). A method developer may apply for review of a method modification or a new method through the ATP program. More detailed information on the ATP may be found a t water.epa.gov/scitech/methods/cwa/atp.8



### Appendix B
Example Approaches for the Alternative Monitoring M echanism
In this Appendix we describe three example approach es that could be used to define the boundaries and requirements of an alternative monit oring mechanism. These are for illustrative purposes only and are intended to help generate com ments and ideas on approaches the EPA could consider.

Example Approach A: Detailed Annual Request In this example approach, in order to use alternati ve monitoring, a facility could submit an annual detailed request describing the monitoring a pproach that it wishes to use. An alternative method could be eligible for use for any monitoring parameter in any subpart, if it is approved. In this approach, each type of monitoring change co uld be grouped into a major or minor category and those monitoring changes considered to be minor would not need a detailed request to use alternative monitoring. Under the GHGRP, a major change could include adoption of newer monitoring technologies or application of exi sting technologies to new types of source categories or process units. Smaller changes, such as more frequent monitoring, could be considered minor changes and need less or no notifi cation. More attention and review could be given to alternative monitoring that is considered to be a major change. For example, a facility could engage in a trial period of several months to a full reporting year during which they could provide data for both the monitoring methods prescr ibed in the rule and the alternative monitoring approach so that a direct comparison may be performed to ensure data quality. An internal list of implemented or approved alterna tive monitoring approaches by subpart could be maintained under this example approach. An alte rnative monitoring approach accepted for one facility within a subpart would be acceptable f or another facility within the subpart as long as data quality is improved for that subpart.

Considerations:

- What could be the limits or criteria for ensuring d ata quality?

- What could be the length of the trial period for ma jor changes?

- How could major and minor changes be defined?

- What justification could a reporter provide to prov e applicability and accuracy of the alternative method (e.g., EPA Method 301)?

Example Approach B: One-Time Detailed Request In this example approach, a facility could submit a one-time detailed description of the alternative monitoring approach that it wishes to u se for approval. Approval for the use of this alternative monitoring approach could then be in ef fect for the duration of the use of that approach. A facility would only need to submit add itional information for further approval if any changes are to be made to that approach in futu re reporting years.9

For this example approach, the applicability of alt ernative monitoring could be limited to only certain subparts. For example, the alternative mon itoring approach could be applicable to only direct emitter subparts, only supplier subparts, or only those subparts where facilities have requested alternative monitoring in the past. Any monitoring parameter within the determined subparts could be eligible for an alternative metho d to be used, if approved, however that parameter would need to fit into the rule-specified calculation equations. No alternative calculation equations could be approved.

All facilities that wish to use alternative monitor ing could submit the same initial detailed request regardless of whether the change is minor or major. A public list of approved alternative monitoring ap proaches by subpart could be maintained. An alternative monitoring approach accepted for one fa cility within a subpart could be acceptable for another facility within the subpart as long as data quality is improved.

Considerations:

- For which subparts could a facility request to use alternative monitoring?

- What could be limits or criteria for ensuring data quality?

- What justification could a reporter provide to prov e applicability and accuracy of the alternative method (e.g., EPA Method 301)?

Example Approach C: Public List of Possible Altern ative Monitoring Technologies In this example approach, a list of monitoring tech nologies that are considered advanced and innovative could be made available. A facility cou ld submit a one-time indication to use this technology. The list could include the parameters t o be monitored, the specific GHG to be measured, the frequency of measurement, the calcula tion methods for emissions, and other details. No official or formal approval would be n eeded. For this example approach, use of alternative monit oring could be limited to certain subparts to which the specific technologies apply. The types o f monitoring approved could be maintained by subpart. Alternative monitoring approaches coul d not automatically be applied to other similar facilities or process units unless listed.

Considerations:

- What could be the specific criteria for an alternat ive monitoring technology?

- How could information on advanced and innovative te chnologies be solicited so they could be included on the prescribed list? Could a technolog y be added to the list at a later time, and if so, how?

- How could a technology be assessed to determine tha t it is appropriate for a particular subpart?