Karin Ritter 

Manager 

Regulatory and Scientific Affairs 

1220 L Street, NW 

Washington, DC 20005-4070 

USA 

Telephone 202-682-8472 

Fax 202-682-8270 

Email ritterk@api.org 

www.api.org 

May 3, 2011 

William M. Irving 

Climate Change Division 

U.S. Environmental Protection Agency 

Office of Atmospheric Programs (MC 6207J) 

Ariel Rios Building 

1200 Pennsylvania Avenue, N. W. 

Washington, DC 20460 

Re: Mandatory Reporting of Greenhouse Gases: Subpart W: Best Available 

Monitoring Methods

Dear Mr. Irving: 

I am writing regarding an issue of urgent concern - the availability, and imminent 

deadlines to apply for the use, of “Best Available Monitoring Methods” (BAMM) under Subpart 

W. At the outset, API appreciates EPA’s issuance of an administrative stay extending the initial 

deadlines for BAMM, as well as a guidance document regarding BAMM. The stay and the 

guidance are helpful, but they do not provide the full relief needed, as I explain below.

I. Background and Request for Extension 

As you know, under the rule as amended by the administrative stay, reporters may use 

BAMM until September 30 for well-related data and certain other specified activities without 

making a request to EPA. 40 C.F.R. §§ 98.234(f)(2)-(3), (5)(i)-(ii); 79 Fed. Reg. 22825 (April 

25, 2011). Requests to use BAMM for these activities from September 30 to December 31, 2011 

and for leak detection and quantification activities from January 1, 2011 to December 31, 2011 

must be submitted by July 30, 2011. Id.. §§ 98.234(f)(4)-(7). Finally, if reporters want to extend 

the use of BAMM beyond December 31, 2011 “in extreme circumstances,” they must submit a 

request by September 30, 2011. Id. § 98.234(f)(8). The current rules do not establish a deadline 

for EPA to respond to BAMM requests. 

Given the extraordinary scope of Subpart W—both the hundreds of thousands of discrete 

sites and sources whose emissions must be quantified and reported and their broad geographic 

dispersion—compliance with the monitoring and reporting deadlines and the deadlines to apply 

for approval to extend the use of BAMM are not only unrealistic but infeasible. These problems 

are compounded by the lack of clarity in certain aspects of the rule which has made it difficult 

for reporters to even determine whether BAMM is required for some sources. Given our strong 

collaborative and successful relationship with EPA on many aspects of the GHG Reporting 

Program (GHGRP), we do not use such words lightly. However, for the reasons described 
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below, compliance in many if not most instances will not be possible under the deadlines 

specified, particularly given the relatively short time from finalization of Subpart W and the 

looming deadlines and the vast scope of Subpart W requirements. 

Subpart W thus imposes substantial burdens upon reporters and does not provide them 

adequate time to ensure compliance. As a result, as EPA recognized in the final rule, reporters 

need to have the option to use BAMM in the early stages of the program as they gear up toward 

implementing all their measurement and quantification obligations. Unfortunately, the final rule 

limited “automatic BAMM” to six (now nine) months, imposed tight deadlines for reporters to 

request the use of BAMM and unduly restricted its use beyond 2011. API believes that further 

modifications to Subpart W are needed to make BAMM more widely available through 2012, by 

which time reporters should be in position to employ the required monitoring methods, subject to 

the safety and feasibility exceptions recognized by the rule. 

Under the rule, reporters must identify the sources at which they seek to use BAMM and 

gather a substantial amount of information and data to support BAMM extension requests. See

id. §§ 98.234(f)(5)-(8). As we describe below, although API’s members have been working 

diligently to implement systems to ensure compliance with their data collection and reporting 

obligations under Subpart W, there is insufficient time before the July 30 and September 30 

deadlines to (1) identify those locations which might require BAMM in 2011 or beyond, (2) 

provide the necessary level of detail to support BAMM requests, and (3) ensure compliance with 

the required monitoring methods at all locations once the BAMM allowance sunsets. Reporters 

are required to spend more time navigating the complexities of acquiring BAMM approval for 

facilities that have not been clearly defined by EPA than implementing systems for collecting 

actual data. Obviously having all equipment and systems in place for full compliance with the 

rule by June 30 is not feasible. Importantly, API is not requesting relief from ultimately 

employing the monitoring methods specified in Subpart W or from submitting requests to use 

BAMM with the appropriate supporting data. Rather, API respectfully requests that EPA extend 

the automatic use of BAMM in 2011 and make BAMM more widely available through 2012 for 

all Subpart W source types. 

EPA has recognized in other GHGRP contexts that various extension requests were 

warranted. EPA similarly should extend the BAMM deadlines here to ensure that member 

companies are in a position ultimately to comply with Subpart W and provide the underlying 

information requested by the Agency.

II. The Scope and Breadth of Subpart W Make it Infeasible for Reporters to Meet the 

Application Deadlines for Submitting Requests to Use BAMM. 

The scope and scale of Subpart W and the resulting effort and resources necessary to 

develop and implement systems to comply with the rule are unprecedented, even for the 

GHGRR. It encompasses almost the entire natural gas supply chain from the well-head to local 

distribution to end users, along with oil production both onshore and offshore. The number of 

individual sites and emission sources covered, the geographical dispersion of these sites, and the 

amount of data and information required to be monitored and gathered from these sites and 

sources is substantial. These facts, when combined with the uncertainties associated with the 

rule, make it infeasible for reporters to collect and prepare the information needed to apply for 
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the use of BAMM by the July 30, 2011 and September 30, 2011 application deadlines or to have 

all of the equipment and systems in place by September 30. 

The Onshore Petroleum and Natural Gas Production segment of the Petroleum and 

Natural Gas Systems source category (Onshore Production) alone covers hundreds of thousands

of well sites along with tens of thousands of sites “associated with a well pad” (which is not 

defined or discussed in the rule). These sites are widely dispersed across hundreds of thousands 

of square miles in all of the oil and gas producing basins across the United States. The seven 

additional industry segments subject to Subpart W extend this coverage to tens of thousands of 

additional offshore platforms, onshore sites and facilities, and natural gas distribution sites. 

Within each of these industry segments, Subpart W mandates that reporters monitor and 

determine emissions from multiple source types; for example, the Onshore Production portion of 

the rule covers 22 distinct source types. Each of these source types requires the collection of a 

broad variety of information, data points, analyses, models, and/or measurements to determine 

emissions and submit emission reports. 

Subpart W thus requires that each reporter undertake a substantial effort to: 

(1) understand the rule and how the rule applies to its operations and sites; (2) assess its current 

information and monitoring systems against the rule’s requirements; (3) determine what gaps 

exist; (4) engineer, plan, budget and schedule actions needed to close these gaps; and (5) put 

these actions into place. This entire chain of actions inevitably will take significant time and 

skilled resources to accomplish. Simply put, these actions cannot be completed in the time 

frames set forth in the final Subpart W rule. Moreover, rushing to put equipment and systems in 

place without the proper engineering, planning, and evaluation is not a viable option, given that 

the materials handled by the industry – oil and natural gas – necessitate that any modifications to 

equipment be made with caution to ensure safety. Reporters should not be placed into a position 

where safety is potentially compromised simply to meet unrealistic and unnecessary 

requirements of the rule. 

The problems created by the large number of facilities that are subject to the rule are 

exacerbated by their wide geographic distribution. Unlike a chemical plant or a refinery, oil and 

natural gas operations are spread out over huge geographic areas and are typically not staffed at 

all times. Often there is no electricity, difficult access, and little existing infrastructure or 

communications ability at these disparate locations. Given this geographic dispersion of oil and 

natural gas facilities, installation of any additional equipment, monitors, and/or data acquisition 

and transmitting systems will be very challenging. Even traveling to each of these sites requires 

significant time and effort. When this is combined with the specific monitoring methods 

demanded by the rule, reporters cannot realistically meet the rule’s BAMM extension application 

deadlines or have the full suite of required monitoring and recordkeeping systems in place by 

September 30. 

These problems are compounded by the fact that API’s members continue to have 

unanswered questions about the applicability of the rule to some of their operations. These 

include: (1) whether standalone equipment (such as dehydrators, liquid separators, and amine 

treaters) constitutes a gas processing facility; (2) what constitutes a booster station; and (3) what 

constitutes a gathering line. While we understand that EPA is evaluating possible clarifications to 

these source category definitions, companies will not know for certain how Subpart W applies to 
 4 

their operations and whether BAMM extension requests are needed. Companies face the 

prospect of losing the opportunity for case-by-case extensions unless “protective” applications 

are prepared and filed. The effort required to make such filings will be significant (and will 

impose upon EPA a significant burden) and likely will become wasted effort once applicability is 

clarified. 

These unique complexities and burdens posed by Subpart W make it unrealistic and 

infeasible for reporters to (1) determine if the rule applies and to what source category a facility 

belongs to, (2) determine the gaps between the rule requirements and their current information 

systems, (3) identify which sources will need to employ BAMM for the remainder of 2011 by 

July 30, and (4) ensure that all those sources have installed the necessary monitoring equipment 

or ports by the end of 2011 and thus identify which sources will need to employ BAMM beyond 

2011 by September 30, 2011. The final Subpart W rule was published in the Federal Register on 

November 30, 2010. Such a compressed schedule even in ideal conditions would be difficult, if 

not impossible, to meet; winter conditions – limiting site access – during much of this period 

exacerbate the problem. Moreover, the limited time between promulgation and the September 

30, 2011 BAMM application deadline for use of BAMM, combined with the fact that the rule 

significantly restricts the availability for BAMM beyond 2011, is extremely problematic. 

Reporters will not have sufficient time to ensure that monitoring equipment or access ports are in 

place and ready to use by 2012 at all their sources. The challenges of complying with the 

deadlines in Subpart W are complicated by the lack of clarity in some of the rule’s requirements 

and the subsequent inability to implement data collection procedures until clarifications and 

amendments are made. EPA needs to amend the rule to allow not only itself more time to clarify 

confusions inherent in the rule, but also allow reporters more time to apply for permission to use 

BAMM and to allow reporters to install and train staff to operate and collect data when using the 

required monitoring equipment. 

III. The Difficulty of Complying with Subpart W Supports Making BAMM More 

Broadly Available. 

As the previous section explains, EPA has not provided sufficient time for reporters to 

bring their emission sources into compliance with the monitoring requirements of Subpart W, 

thus necessitating an extension of both the application deadlines for the use of BAMM and an 

extension of the time under which BAMM will be more broadly available as an option to 

reporters. In large part, this is because the measurements required for many of the sources 

subject to the rule have not been extensively performed in the past, and these sources do not 

employ equipment or ports to make the required measurements. 

As a result, determining an approach to implement the monitoring or measurement 

requirements for many of the sources covered by the rule and then determining what can be 

accomplished in what time frames is, in itself, a significant undertaking. Before a reporter can 

prepare an application to use BAMM in 2011 or beyond, it must (1) determine the gaps between 

the rule requirements and their current systems to collect data, (2) determine what changes or 

improvements will be necessary, (3) determine the time and schedule requirements to make these 

changes or improvements, (4) determine what changes cannot be accomplished by September 

30th (or December 31), (5) collect the necessary information to complete a BAMM extension 
 5 

request, and (6) file the extension requests for the large number of sites covered. As explained 

previously, this work cannot feasibly be completed under existing deadlines. 

Moreover, it is already evident that many sources do not currently have and will need to 

install monitoring equipment or ports to ensure that they can be monitored in accordance with 

the rule’s requirements. The vast number of facilities subject to the rule, the compressed 

schedule for making these upgrades, and the safety and logistical challenges posed by these 

monitoring requirements means that reporters are unlikely to be able to ensure that this work is 

completed by the December 2011. Accordingly, EPA needs to allow reporters more time to make 

these upgrades. 

Several examples highlight the need for this relief. 

A. Hot-Tapping. 

During our discussion, EPA observed that the ports needed for measurements equipment 

under Subpart W under the rule could be installed by use of “hot-tapping.” API respectfully 

disagrees that hot-tapping is a viable and safe compliance option. Indeed, EPA already agreed to 

provide more flexibility in GHGRP settlement discussions due to hot-tapping concerns. 

API and its members do not undertake hot-tapping of live lines lightly in light of the 

nature of the procedure and the attendant risks. Hot-tapping – installing devices which penetrate 

the pipe or vessel wall while in service – involves welding a “fitting/nipple” on the pipe or vessel 

exterior, installing a full-bore opening valve on this “fitting/nipple,” using specialty tools to drill 

a hole through the pipe or vessel wall, and then installing the device through the penetration 

created. Because it involves welding and drilling on a pipe or vessel which is under pressure and 

contains flammable/explosive gasses the risks are: 

• Uncontrolled release of gas and/or ignition and fire or flash fire; and 

• Burn-through and ignition while welding the “fitting/nipple” on the pipe/vessel. 

These risks can lead to loss of life, injury, equipment damage, facility shut-down, and large 

economic impacts. As a result, companies only use hot-tap procedures in extremely critical 

situations and have strict restrictions on when they can be used and how they are performed. 

Marginal improvement to the accuracy of emissions estimates is not a valid reason for hottapping. Hot-tapping is both risky and is not an option for reporters to meet their measurement 

and reporting obligations under Subpart W. Indeed, EPA has acknowledged these risks by 

allowing for BAMM extensions under GHGRP Subparts P, X and Y due in part to concerns 

about hot-tapping. See 75 Fed. Reg. at 79096 – 79097 (Dec. 17, 2010). 

The risks associated with hot-tapping mean that reporters will need to shut down units in 

order to install ports or other intakes for monitoring equipment. Moreover, EPA should not 

require sources, such as compressor stations, to shut down and depressurize simply to enable 

installation of ports and/or monitoring equipment. As with Subparts P, X and Y, EPA should 

allow reporters to wait until the “next scheduled turnaround” to make such installations. This 

will extend the time it will take to complete this work at the thousands of sites and units subject 

to Subpart W because it cannot realistically be completed in just over one year. 
 6 

B. Gas well venting during well completions and workovers from hydraulic 

fracturing.

There are two calculation methods for determining volume this category of sources. See

40 C.F.R. § 98.233(g). Neither of these methods have been widely implemented or practiced in 

the industry – particularly in a compliance setting where it must be accomplished and 

documented strictly in accordance with the rule’s requirements. More time is needed to allow 

the necessary equipment to be designed, built and available and these sources to be modified to 

perform the required measurements to calculate emissions as required by Subpart W. 

Calculation Method 1 for these sources requires measurement of flow-back volume from 

clean-up of a well after hydraulic fracture stimulation. This is extremely difficult to do, 

especially in light of the rule’s provisions that any such measurement be done in accordance with 

the provisions of 40 C.F.R. § 98.234(b), which in turn requires the metering be done in 

conformance with the requirements of 40 C.F.R. § 98.3(i). Flow-back fluids vary widely during 

flow-back for clean-up of a well post-fracture stimulation. They start as mostly fracture carrier 

fluids (typically water) with proppant (typically sand), progress to a mixture of fracture carrier 

fluids and formation fluids, and, only towards the end of a clean-up, do they become mostly 

formation fluids. These facts preclude metering without first separating the sand and liquids 

from the gas. Due to the erosive nature of the high pressure and high rate flow-back with sand, 

which can quickly cut through piping and surface equipment, such separation would typically 

have to be accomplished using specially “purpose designed” equipment engineered to avoid or 

withstand the erosive nature of the flow-back. Despite the voluntary practice of “green 

completions” by many companies in the Onshore Production industry, this type of “purpose 

designed” equipment is not abundant or readily available in the quantities needed to satisfy the 

requirements of the rule. Besides being very expensive, engineering and constructing enough 

equipment to accomplish the number of measurements required under the rule will take years, 

not weeks or months. This is especially true in that each covered operator in each of the relevant 

44,000 + EIA named fields must do an initial measurement during 2011 and then subsequent 

measurements every two years in each “field” if using Calculation Method 1. The necessary 

equipment to safely separate the liquids and sand from flow-back fluids simply will not be 

available quickly enough to meet the rule’s requirements. 

Calculation Method 2 poses similar challenges. This method requires calculation of both 

subsonic and sonic flow through a “choke” during flow-back for well clean-up. As noted above, 

the fluid composition varies significantly throughout flow-back for well-cleanup post fracture 

stimulation. As the nature and composition of the overall fluid changes, the flow behavior 

through a restricted path (choke) will change radically and quickly. Coupled with the non-steady 

and widely varying flow volume as a well cleans-up and unloads liquids in slugs identifying 

periods of sonic and sub-sonic flow cannot technically be accomplished and accounting for each 

of the flow conditions cannot be accomplished under the rule.1

 Although theoretically possible, 

this method is unlikely to be technically possible in actual practice. 

 

1 In its comments, API offered an alternative calculation method of assuming fluid properties 

equivalent to the produced fluids (predominantly gas) in a sub-basin area, assuming choke flow 

(sonic) throughout a well clean-up, monitoring and recording pressure upstream and downstream 
 7 

In short, it will take reporters a considerable amount of time to obtain the necessary 

equipment for Method 1 or be able to install sufficient instrumentation to enable Method 2 

(which may not be technically achievable, as explained in section iii.7 of API’s Petition for 

Reconsideration). BAMM needs to be more widely available for these sources while these 

actions are underway. 

C. Compressor venting. 

Although compressor venting will be discussed in more detail in a subsequent 

submission, measurement of compressor venting required by 40 C.F.R. §§ 98.233(o) and (p) has 

not been widely practiced in the past, and no proven methodologies have been applied outside of 

study or research settings. Such measurements also face a large number of safety challenges. 

With the new “vents” added in the final rule, the burden to collect the required data is significant. 

This challenge is amply demonstrated by the study being led by the University of Texas that EPA 

is funding, which is struggling to achieve the measurements required by the rule for a truly small 

number of facilities and compressors. 

The novelty of these measurements is compounded by the fact that the final rule 

substantially expanded the reporting requirements for centrifugal and reciprocating compressors 

at onshore natural gas processing facilities, by adding dry seal centrifugal compressors, blow 

down valve leakage, and isolation valve leakage. These additions more than doubled the number 

of required measurements as compared to the proposed rule. Reporters thus need more time to 

evaluate these additional sources, including coordinating assessments with operations and 

qualified personnel across the country, identifying the necessary changes in configuration, and 

properly planning the implementation of these measures. The large number of compressor vents 

and their dispersion over wide areas creates significant logistical problems. Extending BAMM 

will make it feasible to complete these steps in a safe and comprehensive manner. 

* * * 

As the above sections demonstrate, the scope, burdens and novelty of the requirements of 

Subpart W make it necessary to expand the time during which BAMM may be liberally 

 

of a choke, and recording flow-back time in order to arrive at a volume/unit-of-time to apply to 

other completions in the same sub-basin area. Although this approach should yield “higher than 

actual” gas volumes and emissions, it likely could be accomplished in a more reasonable 

timeframe than EPA’s required methods. It is possible, over time and on a small number of 

cases, to conduct both the suggested method and EPA’s required measurements “side-by-side” to 

establish the degree of emissions bias associated with the suggested approach. EPA would still 

receive emission estimations, number of completions done, and the flow-back time from each 

sub-basin area. Nevertheless, even if API’s suggested methodology were authorized, reporters 

would need a significant amount of time and effort to craft and test procedures, to obtain and 

install the necessary monitoring equipment, to design and implement data acquisition systems, 

and to design data handling and archive systems. 
 8 

employed and extend the deadlines for BAMM applications. API appreciates this opportunity to 

share its concerns with EPA. 

Sincerely, 

Karin R. Ritter 

cc: Roger Fernandez 

Paul Gunning 

Norman Rave 

Ragan Tate