1 1227842_1 Waste Management’s Petition for Reconsideration of 2013 Revisions to Greenhouse Gas Reporting Rule and Final Confidentiality Determinations for New or Substantiall y Revised Data Elements Docket I.D. EPA-HQ-OAR-2012-0934

I. Introduction Pursuant to Section 307(d)(7)(B) of the Clean Air Act, 42 U .S.C. § 7607(d)(7)(B) (“CAA” or “Act”), Waste Management, Inc. and its operat ing subsidiaries (hereinafter, collectively referred to as “WM”) request that the Envir onmental Protection Agency (“EPA” or “Agency”) reconsider its final rule, 2013 Revisions to Greenh ouse Gas Reporting Rule and Final Confidentiality Determinations for New or Substantially Revised Data Elements, published at 78 Fed. Reg. 71904-71981 (Nov. 29, 2013) (the “Final Rule”). As set fort h herein, WM seeks reconsideration of a single aspect of Subpart HH of the Final Rule that was impracticable to comment upon previously, arose after the period for public co mment (but within the time specified for judicial review), and is of central releva nce to the outcome of the rule. As an initial matter, WM commends EPA for many of it s technical corrections to Subpart HH of the Final Rule, governing municipal solid waste (“MS W”) landfills. In particular, WM supports EPA’s conclusion in the proposal for the Final Rule that a single default value of 10% is not an appropriate basis on which to quantify the effect o f methane oxidation on emissions. See 2013 Revisions to Greenhouse Gas Reporting Rule and Final Confid entiality Determinations for New or Substantially Revised Data Elements; Proposed Rul e, 78 Fed. Reg. 19802-19877, 19825 (April 2, 2013). Further, WM supports EPA’s conclusion that the oxidation fraction is primarily dependent on methane flux, and the adoption of a “binned appro ach” to methane oxidation that

will allow landfills to use oxidation fractions that ar e based on site-specific methane flux rates.

Id. As WM emphasized in its comments on the proposed Fina l Rule, WM is pleased that EPA2 1227842_1

reviewed and relied on sound, peer-reviewed scientific studies showing that a majority of MSW landfills oxidize methane at fractions much greater th an the default oxidation value of 10%. The result of the Agency’s thorough review of existing data, t he binned approach to methane oxidation fractions, will ensure that greenhouse gas (“GH G”) emissions from MSW landfills are reported more accurately because the Final Rule takes into account site-specific factors that

influence a MSW landfill’s methane oxidation rate. Though WM supports the binned approach for determining methane oxida tion, WM

submits this Petition for Reconsideration because the Fi nal Rule arbitrarily limits the availability of the binned approach to those landfills that have at leas t 24 inches of soil cover over a majority of the landfill area containing waste. See 78 Fed. Reg. at 71925. EPA did not identify or solicit comment on the 24-inch soil cover requirement in the pr oposal for the Final Rule; had it done so, WM would have established, as it does in this Reconsidera tion Request, that the 24-inch soil cover requirement is not supported by the scientific lit erature and will result in inaccurate reporting of MSW landfill GHG emissions. Specifically, the Final Rule’s limitation of the binned approach to landfills meeting the 24-inch soil cover r equirement will erroneously limit many MSW landfills to using the 10% default oxidation facto r, instead of the binned approach, even though actual methane oxidation fractions will be gr eater than 10%. Accordingly, WM requests that EPA convene a reconsideration proceeding t o fully evaluate and correct this error. II. Background to WM WM is the leading provider of comprehensive waste and enviro nmental services in North America, and the largest recycler in North America. In addition, WM is a leading producer of renewable, waste-based energy, producing enough energy to po wer roughly 1.2 million homes each year. WM expects to nearly double its energy output by 2020, producing enough energy to3 1227842_1

power more than 2 million homes by that date. Headquarter ed in Houston, TX, WM operates in 48 U.S. states and in most Canadian provinces. WM’s net work of operations includes 390 collection operations, 310 waste transfer stations, 128 rec ycling facilities for differing commodities, 36 organic composting and processing facilities, 241 reporting MSW landfills, 137 landfill gas-to-energy projects, 17 waste-to-energy (“W TE”) plants, and five independent power production plants. 1 WM subsidiaries operate a number of landfills that c ontain less than 24 inches of cover over the majority of their area containing waste and, on that basis, will not be able to use the 25% or 35% oxidation values in the binned approach. Instead, under the Final Rule, these entities will be required to use the default oxidation value of 10%, which EPA has recognized is biased low. Thus, these entities are directly affecte d and harmed by the 24-inch soil cover requirement. WM’s interest in the Final Rule derives from WM’s opera tion and maintenance of active and closed MSW landfills and WTE plants, which subject WM to the Final Rule’s mandatory GHG emission reporting requirements. Given the size, number, and diversity of WM’s facilities, reporting WM’s GHG emissions is more time-consuming and co mplicated than for many other entities subject to the Final Rule. WM has gained conside rable experience calculating and reporting GHG emissions, and has been eager to work cooperat ively with EPA in sharing information and refining GHG emission estimation methodo logies where appropriate. WM has worked closely with EPA on the revisions to the GHG Re porting Rule, and believes that the binned approach for determining methane oxidation is correct. However, under the Final Rule,

1 These numbers are based on 2013 figures. WM’s statements throughout this Petition for Reconsideration concerning WM’s GHG reporting landfills refer to the 240 landfills that WM owned prior to the third quarter of 2013, at which time WM acqu ired a 241st MSW landfill required to report GHG emissions.4 1227842_1

WM could be precluded from using the binned approach to methane o xidation at two-thirds of

the landfills within its network. This is because most active landfills with predominantly

intermediate cover will not meet the 24-inch soil cov er requirement across the majority of landfill areas containing waste, even though they are fu lly compliant with federal and state requirements. 2 As explained in greater detail below, imposition of the 24-inch soil cover requirement as an independent factor for determining methane oxidation is no t supported by the peer-reviewed scientific literature that provided the basis for the binne d approach. Neither WM nor any other affected entity had an opportunity to provide comments on th e Final Rule’s soil cover requirement for MSW landfills seeking to use the binned appro ach to methane oxidation fractions, as this requirement is entirely new in the Final Rule. Thus, WM now seeks reconsideration of the Final Rule so that EPA may re evaluate and correct this issue. WM submitted comments to EPA on the proposed Final Rule. A copy of WM’s comments dated May 16, 2013, Docket I.D. No. EPA-HQ-OAR-2012-0934-0041, is attached hereto at Appendix “A” and shall be referred to herein as the WM Proposal Comments.

III. Grounds for Reconsideration Pursuant to Section 307(d)(7)(B) of the CAA, EPA “ shall convene a proceeding for reconsideration of [a] rule and provide the same procedural rights as would have been afforded

had this information been available at the time the rul e was proposed” so long as the party seeking reconsideration can demonstrate: (1) “that it wa s impracticable to raise such objection” during the public comment period or that “the grounds for such objection arose after the period

2 WM’s two-thirds estimate is based on federal and state c over depth requirements at both active and closed WM MSW landfill sites. Although not required, some of these sites may, as a practical matter, meet the 24-inch soil cover requireme nt.5 1227842_1

for public comment (but within the time specified for judi cial review)”; and (2) “such objection

is of central relevance to the outcome of the rule.” 42 U.S.C. § 7607(d)(7)(B). Against this standard, and for the reasons set forth herein, EPA mus t convene a reconsideration proceeding that allows for public comment regarding whether it is appro priate for EPA to limit the use of the binned approach for methane oxidation to MSW landfills having 24 inches or more of soil cover over a majority of the landfill area containing waste. Depth of soil cover as a prerequisite for using the binned approach to methane oxidation fractions was no t identified by EPA during the public comment period for the Final Rule, and was not subjec ted to public comment during the rulemaking process. Further, WM’s objection to this prere quisite is of central relevance to the

Final Rule. A. WM Could Not Have Commented On the Soil Cover Requirement During the GHG Reporting Rule Development Process EPA did not identify a 24-inch soil cover requirement, o r in fact any cover depth requirement, as a prerequisite to the binned approach to methan e oxidation during the public comment period for the Final Rule. By contrast, the pr ocedural history of the Final Rule and EPA’s statements throughout that process correctly focu sed on methane flux as the key factor in determining site-specific methane oxidation rates. There fore, WM had no reason or basis, prior to the issuance of the Final Rule, to submit comments to EPA evaluating the impact of depth of soil cover, as a stand-alone factor, on methane oxidat ion. The 24-inch soil cover requirement was not a logical outgrowth of the proposed rule, and th erefore WM was denied any meaningful opportunity for comment on this issue.

1. Methane Oxidation Under the Proposed GHG Reporting Rule On April 2, 2013, EPA proposed the “2013 Revisions to the Greenhous e Gas Reporting Rule and Confidentiality Determinations for New or Subs tantially Revised Data Elements,”6 1227842_1

published at 78 Fed. Reg. 19802-19877 (the “Proposed Rule”). In Sectio n II.Q of the preamble to the Proposed Rule, EPA discussed its proposal to allo w MSW landfills to use methane

oxidation values above the 10% default fraction at MSW la ndfills with moderate or low methane flux rates. Therein, EPA stated “we are proposing to amend the oxidation default value used in Equation HH-5, HH-6, HH-7, and HH-8 of subpart HH. We rec eived comments from landfill owners and operators that the oxidation fraction default value of 10 percent that is required to be used in these equations is too low and that many landfills exhibit much higher methane oxidation fractions.” 78 Fed. Reg. at 19825. In explaining the basis fo r the amendment, EPA stated that

“numerous U.S. landfills have been tested to estimate the oxidation fraction” since the passage of the original GHG Reporting Rule. Id. EPA reviewed those methane oxidation studies and “[b]ased on [that] review, [EPA] agree[s] that the 10 per cent soil oxidation fraction likely

underestimates the amount of methane oxidized in the soi l layer when the landfill gas flow through the soil surface is reduced.” Id. Therefore, EPA correctly developed a binned approach that allows MSW landfills to apply one of three differ ent oxidation fractions, depending on the

rate of methane flux at a landfill. EPA noted that its own analysis of the existing scient ific literature on methane oxidation

at MSW landfills revealed that “methane flux rate entering the soil layer ” is the “ key variable ” for determining methane oxidation. 3 Id. Reflective of methane flux being the key determinant of methane oxidation rates, EPA proposed “thre e different default oxidation fractions depending on [a landfill’s] methane flux ‘bin,’ found in new Proposed Table HH-4.”

Id. As proposed, Table HH-4 set forth three different “bins” within which a MSW landfill could

3 For an overview of the methane oxidation data that EPA consulted while developing Subpart HH to the Final Rule, see the Solid Waste Industry for Climate Solutions’ (“SWICS ”) addendum entitled, “SWICS 2.2 Methane Oxidation Addendum 2012 Addendum,” at Docket I. D. No. EPAHQ-OAR-0934-0088.7 1227842_1

fit. 78 Fed. Reg. at 19867-68. At MSW landfills “where the methane flux rate is projected to be high (greater than 70 grams/m 2 /day), the default oxidation fraction remains as 10 percent . For cases where the methane flux is projected to be low (l ess than 10 grams/m 2 /day), the default proposed oxidation fraction is 35 percent. For cases with moderate methane flux rates (10 to 70 grams/m 2 /day), the proposed default oxidation fraction is 25 percent .” 78 Fed. Reg. at 19825. EPA appropriately concluded that “this binned approach provides a more realistic estimate of the

role of methane oxidation in the surface soil on the me thane emissions than the single default

oxidation fraction.” Id. As a way of further explaining the binned approach to methan e oxidation in the Proposed Rule, EPA stated in the preamble that parties wishing to see a more detailed analysis of the binned approach could consult EPA’s December 2012 Memorandum ent itled, “Review of Methane Flux and Soil Oxidation Data,” which appears in the Final Rule docket at Docket I.D. No. EPA-HQ-OAR-2012-0934-0015 (the “Methane Oxidation Memo”). In the Methane Oxidation Memo, EPA explained that the fraction of meth ane oxidized at a MSW landfill is dependent on a number of factors, including: (1) methane f lux through soil surface; (2) porosity of a landfill’s soil layer; (3) the number and type of microorganisms in a landfill’s surface soil layer; and (4) the soil’s surface temperature and moisture .” Methane Oxidation Memo at 1-2. Though EPA listed certain soil characteristics as potential influencers of methane oxidation rates, at no point in the Proposed Rule or the Methane Oxidation Memo did EPA hint or suggest

that depth of soil cover has any impact on methane oxidation rates or that it would be used by EPA as a defining factor in calculating oxidation rates. I n fact, the Methane Oxidation Memo ultimately concluded that the best approach for accountin g for methane oxidation is to “use a binned approach where the average oxidation fraction is determ ined for landfills based on the8 1227842_1

methane flux rate of the landfill.” Methane Oxidati on Memo at 3. The Methane Oxidation

Memo also concluded that the default fraction of 0.10 is “ biased low” and that when compared with soil type, “the methane flux rate appears to be a much more important factor influencing the oxidation fraction.” Methane Oxidation Memo at 3. Just as in the Propose d Rule, EPA never suggested in the Methane Oxidation Memo th at EPA was considering a 24-inch soil cover requirement as a possible gatekeeper to using t he proposed methane oxidation bins.

2. WM’s Comments on the Binned Approach Having had no indication, either directly or by implicat ion, that EPA was considering depth of soil cover as a possible prerequisite for use of the proposed methane oxidation bins, WM commented favorably on the binned approach in the WM Prop osal Comments. In those comments, WM commended EPA for the Agency’s “careful a nalysis of peer-reviewed literature and numerous peer-reviewed field measurement studies” that “resulted in proposed changes to estimating methane oxidation in landfill cover” that “ will make greater use of site-specific conditions rather than national default assumptions, whi ch will improve the reliability of emission estimates.” WM Proposal Comments at 1-2. WM further noted that WM supported “EPA’s proposed approach to replacing the single, default me thane oxidation value with a more realistic and representative methodology for deriving met hane oxidation based on site-specific data.” WM Proposal Comments at 2. Because depth of soi l cover as a gatekeeper for making use of the methane oxidation fractions was never highligh ted by the Agency as an issue open for public comment, nor implicated by any other commenter prio r to the close of the public comment period, WM accordingly did not provide any comment s concerning the appropriateness of such a requirement.9 1227842_1

3. Methane Oxidation in the Final Rule Despite providing no notice during the public comment period tha t a 24-inch soil cover requirement was being considered as a prerequisite for ma king use of the binned approach to methane oxidation in Subpart HH of the Final Rule, EPA limited the use of the binned approach

to MSW landfills with at least 24 inches of soil cover over a majority of the landfill. For the very first time in the rulemaking process, EPA stated i n the preamble to the Final Rule that “owners and operators of landfills that do not have a s oil cover of at least twenty-four inches in depth for a majority of the landfill area containing was te must use an oxidation fraction of 0.10.” 78 Fed. Reg. at 71925. As a result, EPA amended Table HH-4 in Subpart HH to list 0.10 as the default oxidation fraction “[f]or landfills . . . that do not have a soil cover of at least 24 inches for a majority of the landfill area containing waste,” rega rdless of what the methane flux rates at those landfills may be. 78 Fed. Reg. 71971. As shown above, the gatekeeping function of depth of soi l cover was never addressed by the Agency prior to the issuance of the Final Rule, nor was such issue opened for public comment. Nevertheless, EPA noted that, because of publ ic comments received, the Agency reviewed the methane oxidation data used to develop the binned a pproach. 78 Fed. Reg. at 71925. Such review led EPA to announce in the Final Rule that “the data upon which the new methane flux-dependent oxidation fractions were based wer e for landfills with soil covers over 30 inches in depth, so it is reasonable to limit the use o f new methane flux-dependent oxidation fractions to landfills with similar soil cover syste ms.” 78 Fed. Reg. at 71925. WM believes this conclusion is factually incorrect, and that limiting use of the binned approach to landfills with certain depth of cover is not supported by the scientific l iterature upon which EPA based its10 1227842_1

review. Further, we were unable to find any materials or a nalyses in the docket that would support EPA’s conclusion that the 24-inch soil cover require ment is necessary for methane oxidation, or even explain the basis upon which it was rea ched. In further explaining the new depth of cover requirement, EPA stated in the preamble that “two commenters noted that oxidation only occurs in lan dfill covers that are comprised of soil with the necessary depth, porosity, temperature and microbi al population” and that it “agree[s] with the commenters who noted that oxidation must be pre dicated on the presence of sufficient soil.” 78 Fed. Reg. at 71925. The comments that the Agency has highlighted as providing support for the 24-inch soil cover requirement appear to ha ve been submitted by Covanta, Inc. at Docket No. EPA-HQ-OAR-2012-0934-0082 and the Center for a Competiti ve Waste Industry (“CCWI”) at Docket No. EPA-HQ-OAR-2012-0934-0050. However, neit her Covanta’s nor CCWI’s comments address depth of soil cover as a prerequis ite or direct parameter for determining methane oxidation. Rather, both Covanta’s an d CCWI’s comments focus primarily

on the rule’s default values for collection efficiency , arguing that the values are too high. At no point, however, do Covanta or CCWI offer any data concerning the imp act of soil depth on methane oxidation rates. 4 For example, Covanta relied on a single study conducted by EPA in 2012 – contradicted by the body of scientific research on c ollection efficiency and oxidation rates at MSW landfills – to argue that the assumed coll ection efficiency in the Final Rule should

have been lower. Covanta Comments at 4. CCWI’s co mments also focus on collection efficiency, their primary argument being that “in order to have an effective oxidizing cover, [a]

4 WM submitted a response to comments raised by Covanta and CCWI. Although WM’s comments were docketed at No. EPA-HQ-OAR-2012-0934-0119, it is uncle ar whether EPA accepted or considered WM’s comments in its formulation of the Final Rule. Nevertheless, because neither Covanta nor CCWI proposed a cover depth r equirement for use of the binned approach, WM’s response could not have, and thus did not, a ddress this issue.11 1227842_1

landfill must sacrifice significant collection capacit y in the active gas system.” CCWI Comments at 10. Thus, CCWI does not disagree with the co ncept of methane oxidation, but merely argues that the better way to “reduce fugitive em issions [from MSW landfills] has nothing to do with oxidation, but with the installation of a composite cover, including a geomembrane, which defeats oxidation.” CCWI Comments at 12. Though CCWI mistakenly discounts the role of methane oxidation in reducing GHG em issions at MSW landfills, CCWI’s comments cannot be read as supporting a soil cover requireme nt of any depth. In short, though EPA appears to have relied on the Covanta and CCWI comme nts as supporting the 24-inch soil cover requirement, they do not.

4. The 24-Inch Soil Cover Requirement Is Not a Logical Outgrowth of the Proposed Rule The United States Court of Appeals for the District of C olumbia (“DC Circuit”) has consistently held that an agency does not satisfy the not ice and comment requirement when the final rule is not the “logical outgrowth” of the propo sed rule. See e.g. Environmental Integrity Project v. EPA , 425 F.3d 992, 996 (D.C. Cir. 2005); Northwest Maryland Waste Disposal Authority v. EPA , 358 F.3d 936, 951-52 (D.C. Cir. 2004). The 24-inch soil cover requir ement is not the logical outgrowth of the Proposed Rule because n o interested party could have anticipated such a limitation being included in the Final Ru le. A requirement in a final rule is the logical outgrowth of a proposed rule only if “interested parties should have anticipated that the change was possible, and thus reasonably should have filed their comments on the subject during the notice-and-comment period.” Northwest Maryland Waste Disposal Authority , 358 F.3d at 952. Indeed, the “logical outgrowth doctrine does not exten d to a final rule that finds no roots in the agency’s proposal because something is not a logical o utgrowth of nothing.” Envtl. Integrity Project , 425 F.3d at 996. Similarly, the logical outgrowth doctrin e does not apply “in a scenario12 1227842_1

where interested parties would have had to divine the agency ’s unspoken thoughts because the final rule was surprisingly distant from the Agency’s prop osal.” Id. (internal quotation marks omitted) (internal citations omitted). The 24-inch soil cover requirement at issue here is simil ar to circumstances examined in International Union, United Mine Workers of America v. Mine Safety and Health Administration, in which the D.C. Circuit found that an aspect of a fi nal rule was not subjected to

sufficient notice and comment. The final rule in International Union included a velocity cap of 500 feet per minute for belt entry air ventilation systems

. International Union , 407 F.3d 1250, 1252 (D.C. Cir. 2005). The proposed rule, however, did not incl ude a velocity cap, but instead included a 300 feet per minute velocity minimum. In the prea mble to the proposed rule, the Mine Safety and Health Administration (“MHSA”) stated that empirical evidence showed a cap

was not needed. Id. Further, nothing in the rulemaking docket alerted interes ted parties to “the possibility of a maximum cap much less one set at 500,” inc luding two reports previously published by the MHSA. Id. at 1260. During a public hearing on the rule, MHSA received som e comments that a maximum velocity should have been propose d. After receiving such comments, however, MHSA gave “no indication” that it was inten ding to adopt such a standard. Id. at 1261. The DC Circuit found that the velocity cap required by th e final rule was not a logical outgrowth of the proposed rule because no comments specifically s uggested a 500 foot per minute cap, and even if they had, “MHSA did not afford a comparable public notice of its intent to adopt, much less an opportunity to comment on such a cap.” Id. Much like the velocity cap, the 24-inch soil cover requirement is so distant from the Proposed Rule that WM could not have anticipated its

inclusion in the Final Rule. EPA’s Methane Oxidation R eport does not discuss depth of soil cover as a prerequisite for the recommended binned approach, a nd no comments submitted to13 1227842_1

EPA suggested a minimum depth of cover requirement for the binned approach. Although EPA’s preamble statements in the Final Rule attempt to identify a basis for the soil cover requirement, EPA’s statements are not accurate and are not supported by the scientific literature on which they are purportedly based. Accordingly, it was i mpracticable for WM or any other affected entity to comment on the soil cover requireme nt prior to publication of the Final Rule. B. The Soil Cover Requirement Is of Central Relevance to t he Outcome of the GHG Reporting Rule The DC Circuit, quoting EPA, has stated that an objection “is of central relevance to the outcome of [a] rule” when that objection “provides substa ntial support for the argument that the regulation should be revised.” Coalition for Responsible Regulation, Inc. v. EPA , 684 F.3d 102, 125 (D.C. Cir. 2012). Clearly, in this case, WM’s objection s are of central relevance to the outcome of the Final Rule because they support a conclu sion that the 24-inch soil cover requirement is not an appropriate prerequisite for use o f the binned approach, as set forth below at Section IV. Further, as a result of the 24-inch soi l cover requirement, MSW landfills will be precluded from using the binned approach to methane oxidation fracti ons approved by EPA as set forth in Subpart HH of the Final Rule if they do n ot have 24 inches of soil cover over a majority of the landfill area containing waste. These MSW landfills would suffer the burden of having to continue to over-report their GHG emissions s imply because they do not have a depth

of soil cover that meets the 24-inch limitation introduc ed by the Agency for the first time in the preamble to the Final Rule. As discussed in greater detail in Section IV, below, mos t active landfills do not have 24 inches of soil cover over a majority of the landfill area containing waste, because most active landfills comprise areas primarily under intermediate cover. Though federal law prescribes minimum depths for landfill areas under daily and final c over, minimum cover depths for areas14 1227842_1

under intermediate cover are prescribed by the states. The majority of states specify that intermediate cover must be at least 12 inches, or speci fy a depth of 18 total inches, which include 6 inches of daily cover. Therefore, a requirement to meet 24-inches of soil cover will prevent many active landfills, including a number of landfills o wned and operated by WM, from using the binned approach to methane oxidation fractions, notwithstand ing that those fractions are not directly impacted by cover depth. In addition to failing to provide any notice of the 24-inch soil cover requirement, EPA did not suggest in the Proposed Rule t hat it would apply the binned approach differently to active landfills under interme diate cover as compared to closed landfills

under final cover. 5 Under the Final Rule, a majority of WM’s reporting MSW l andfills (and, presumably, a majority of all reporting active MSW landfills) will be required to use the 10% default fraction that the binned approach was meant to replace and that EPA has recognized is underrepresentative of the actual methane oxidation fractions realized at many MSW landfills. Such a result is inconsistent with EPA’s stated purpose in pro mulgating the binned approach and is contradicted by the best available scientific evidence. IV. The 24-Inch Soil Cover Requirement Is Unnecessary and Inconsistent with the Scientific Data As set forth at length above, EPA undertook a robust an d technically accurate analysis of the 10% default factor for methane oxidation, and correct ly concluded that the default factor was

5 In EPA’s Summary of Public Comments and Responses for Greenhouse Gas Reporting Rule: 2013 Revisions to the Greenhouse Gas Reporting Rule and Confid entiality Determinations for New or Substantially Revised Data Elements (the “Respons e to Comment Document”), EPA, for the first time, stated that “the use of binned oxidation f ractions should be limited to landfills with final soil covers over most of the landfill area tha t contains waste.” Response to Comment Document at 191. It is not clear from this response whet her EPA intended this statement as providing a basis for the 24-inch soil cover requirement, but this is the first and only time such concept appears in the administrative record.15 1227842_1

not the most appropriate indicator for methane oxidation i n MSW landfills. EPA’s proposed binned approach acknowledges, based on a multitude of scientifi c data, that methane oxidation fractions are generally greater than 10% at MSW landfill s, and that methane flux is the key variable for determining methane oxidation. Imposition of a cover depth requirement as a prerequisite for use of the binned approach to methane oxidatio n, however, is not necessary, because neither the study data nor information gathered duri ng the rule development process support the use of a 24-inch soil cover requirement. Such a requirement is tantamount to replacing methane flux with cover depth as the key varia ble for determining methane oxidation, a conclusion that contradicts EPA’s statements during the rulemaking process and is not supported by the available science.

A. The Scientific Literature Related to Methane Oxidation Does Not Support EPA’s Conclusion that 24 Inches of Soil Cover is a Necessary or Appropriate Prerequisite for Using the Binned Approach EPA appears to have based its decision to require 24 inches of soil cover as a prerequisite to use of the binned approach on a concern that landfills w ith low methane flux and little soil

cover could use an oxidation factor of more than 10%. How ever, the record does not support the 24-inch soil cover requirement, or its purported correlati on to methane oxidation. Although the average reported soil-cover depth data in the scientific literature cited in the 2012 SWICS

Addendum – to the extent that such information was included in the studies – is 24 inches, twothirds of the study authors in the SWICS Addendum appear to ha ve viewed depth of cover as so immaterial to methane oxidation fractions that they fai led to even specify cover depth in their studies. That is, merely 32 of the 95 measurements refere nced in Table 2 of the 2012 SWICS16 1227842_1

Addendum even bothered to indicate cover depth, and even the n those authors listed a range of other factors influencing methane oxidation. 6 More importantly, though the average reported soil cover depth at landfills in the 2012 SWICS Addendum is 24 inches, this simple average does not suppor t the conclusion that 24 inches of soil cover is necessary for proper methane oxida tion. To establish such a regulatory prerequisite, EPA should have, but did not, demonstrate a c orrelation between the fraction of methane oxidized and cover depth. There must be an arti culated reason, with basis in the administrative record, to condition use of the binned appro ach upon 24 inches of soil cover depth. See e.g. Sierra Club v. Costle , 657 F.2d 298, 323 (D.C. Cir. 1981) (stating that during an agency rulemaking the “agency must consider all of the rele vant factors and demonstrate a

reasonable connection between the facts on the record and the resulting policy choice”). In fact, nothing in the record supports such a correlation. Rather , a review of the scientific literature confirms that the 24-inch soil cover requirement is not scientifically valid because there is no

demonstrated correlation between methane oxidation and so il depth. As indicated in the graph attached to this Petition as Fi gure 1, there is no statistically significant correlation between cover depth and the amoun t of methane oxidation. Figure 1, Chanton, 2014 (unpublished), was developed to provide a graphical represe ntation of the relationship between depth of soil cover and methane oxida tion fractions for the 32 measurements from the SWICS studies that reported cover de pth. The graph clearly shows that there is no significant correlation between the cove r depths and oxidation rates reported in those studies, as indicated by the scatter of oxidation data at almost every cover depth. A perfect

6 Table 2 of the 2012 SWICS Addendum does not itself reference cover depth as a relevant data point for determining methane flux, and these data points are not otherwise readily available in the docket.17 1227842_1

correlation of r 2 = 1.0 would show the data points aligning along a trend line and would demonstrate that methane oxidation increases with depth of c over. Instead, the studies show that

the value of r 2 is very low, at only 0.07. Further the p-statistic, whic h describes how well the data “fit” a linear relationship between oxidation and co ver depth – as shown by the diagonal line in Figure 1 – is 0.137. Such p value demonstrates a lack of cor relation between soil depth and oxidation rate. By conventional criteria, a p value this high is considered statistically insignificant, whereas a value for p=0.05 or 1/20 chance is t he standard boundary between statistical significance and statistical insignificance. Stated plainly, there is no evidence that the 24-inch soil cover requirement is a reasonable and scien tifically-sound prerequisite for use of the binned approach. Additionally, more detailed review of the studies referen ced in the 2012 SWICS Addendum does not support the conclusion that soil depth is a significant factor influencing

methane oxidation. 7 In fact, many of the studies conclude that methane oxida tion primarily

7 See Barlaz et al ., “Evaluation of a biologically active cover for mit igation of landfill gas emissions,” Environmental Science and Technology, 38: 4891 – 4899, 4891( 2004) (“Several factors have been shown to influence the extent of CH 4 oxidation in landfill cover soils, including CH 4 and O 2 concentrations, temperature, moisture content, soil composition, moisture holding capacity, pH, and nutrient content.”); Bogner et al ., “Kinetics of Methane Oxidation in a Landfill Cover Soil: Temporal Variations, a Whole-La ndfill Oxidation Experiment, and Modeling of Net CH 4 Emissions,” Environmental Science and Technology, 31: 2504-2514, 2504 (1997) (“Limitations on physical transport become major co ntrols in the field, where relative rates of CH 4 and O2 transport to a given depth are restricted by rates o f methanogenesis below and by O 2 transport from atmospheric sources above. Other fac tors that directly control methanotrophic microbial activity in the field include tem perature, moisture, organic carbon content, available nutrients, and predation by or competiti on with other soil microorganisms.”); Chanton and Liptay , “Seasonal variation in methane oxidation in landfill cover soils as determined by an in situ stable isotope technique,” Global Bi ogeochemical Cycles, 14: 51-60, 57 & 59 (2000) (noting that “[i]n the landfill we studied, tempera ture was the main factor in controlling methane oxidation at specific sites (Figures 8a and 8b)” and that “[m]ethane oxidation occurs in the outer rind of the landfill and is subject to environmental temperature fluctuations which cause rates to be greater in summer a nd lesser in winter.”); Christopherson et al ., “Lateral Gas Transport in Soil adjacent to an Old Landfill: Factors Governing Emissions18 1227842_1

occurs in the upper part of the cover, close to the surfa ce, and several of the studies do not even calculate methane oxidation below a depth of 30 to 45 cm (15 t o 18 inches). 8 Such findings are

and Methane Oxidation,” Waste Management and Research, 19: 595-612, 595-96 (2001) (“Methane oxidation is controlled by various environmental f actors: temperature, soil water content, nutrients, sub-strate, and oxygen concentration s, etc.”); Hilger et al. , “Methane oxidation and microbial exopolymer production in landfill co ver soil,” Soil Biology and Biochemistry, 32:457-467, 457-58, (2000) (“Some of the factors that i nfluence microbial CH 4 oxidation in landfills include climate variables such as m oisture and temperature, as well as CH 4 concentrations, soil type, and pH.” (internal citations omitted)); Kightley et al ., “Capacity for methane oxidation in landfill cover soils measured in l aboratory-scale microcosms,” Applied and Environmental Microbiology, 61:592-610, 600 (1995) (“In conclusion, o ur data show that soil microbial community adapts rapidly to the presence of el evated CH 4 concentrations and can effectively reduce emissions of CH4 from the surface of landfill soil. The capacity for CH 4 oxidation in soil is related to the depth of O2 penetration and to the nutrient status of the soil, which may regulate the extent to which the methanotrophic community can develop.”); Liptay et al., “Use of stable isotopes to determine methane oxidation in l andfill cover soils,” Journal of Geophysical Research, 103:8243-8250, 8243 (1998) (“Soil oxidation potential can change with factors such as temperature, pH, and moisture content.”); Stern et al ., “Use of a biologically active cover to reduce landfill methane emissions and e nhance methane oxidation,” Waste Management, 27: 1248-1258, 1249 (2007) (“Methane oxidation is controlle d by several factors including soil temperature, moisture, and texture, as well a s pH and nutrient content. Previous studies have shown seasonal variation in CH4 oxidation, which is greater during warmer months. In addition, there appears to be an optimum soil moist ure for CH4 oxidation, 10-20% (w/w) at temperatures from 25C to 30 C. . . . Soil composition is also an important parameter, as soil texture and grain size affect oxygen diffusion into landf ill cover soils. Coarser grained soils and porous mulch have been found to be superior to finer grained soils and clays.”). 8 Bogner et al ., supra note 7, at 2510 (concluding that there is one group of microo rganisms “that is continuously active in shallow landfill soils , which thus have the capacity for continuous CH 4 oxidation that rapidly responds to a wide range of dyna mic CH 4 concentrations. The only exception would be during times of periodic surface saturati on.”); id. (“As shown by previous literature, rates of CH 4 oxidation are also dependent on temperature, moisture, and other variables. Nevertheless, in a well-aerated landfill soil over short time frames where a wide dynamic range of CH 4 oxidation rates is possible, the primary controlling var iable appears to be CH 4 concentration and, secondarily, aeration status (O 2 availability).”); id. (“Previous stable carbon isotopic measurements for deep landfill CH4 below the cover materials, suggest that CH4 oxidation is also important, at least periodically, in de eper landfill settings.”) (p. 2510); Chanton and Liptay , supra note 7, at 59(“Methane oxidation occurs in the outer rin d of the landfill and is subject to environmental temperature fluctuations which cause rates to be greater in summer and lesser in winter.”); Chanton et al. , Environmental Science and Technology, 42:665-670, 668 (2008) (“Improved field methods to quantify methane oxidation in landfill cover materials using stable carbon isotopes.”); id. at Figure 1 (demonstrating that C-13 gets more positive betw een a depth of 20 and 60 cm, which is indicative of methane oxidation ); Czepiel et al ., “Quantifying the effect of oxidation on landfill methane emissions ,” Journal of Geophysical Research,19 1227842_1

consistent with the fact that the oxygen necessary fo r methane oxidation is supplied by the atmosphere above the cover of the landfill, and as thic kness of cover increases, it can become more difficult for oxygen to penetrate deep cover depths. Moreover, the scientific data cautions against using any on e factor as a prerequisite for the binned approach. Indeed, the relevant literature shows t hat methane oxidation is influenced by a number of factors other than cover thickness, includ ing climate, moisture levels, and soil

characteristics. See 2012 SWICS Addendum at 16. Thus, no single factor influencing m ethane oxidation is appropriate as a prerequisite for the binned approa ch. Instead, the literature makes clear that the factors influencing methane oxidation are co mplex and interact in different ways at

different landfills. This conclusion is reflected i n the 2012 SWICS Addendum, which

101(D11):16721-16729, 16723 (1996) (“The soils at each location were samp led at 5-cm intervals from the surface to a depth of 25 cm. . . . Th e distribution of oxidation in the soil column was similar in each profile with maximum occurr ing in the 5 to 10-cm depth interval in seven of the nine profiles (Figure 1).”); DeVisscher et al ., “Methane Oxidation in Simulated Landfill Cover Soil Environments,” Environmental Science and Technology, 33:1854-1859, 1854 (1999) (“By combining this kinetic data with the soil gas compo sition data, the actively methane oxidizing zone in the soil column could be determ ined and an in situ assessment of oxygen limitation could be performed. Methane oxidation t akes place manly in the top 30 cm of covering soil.”); Hilger et al. , supra note 7, at 464 (“The CH 4 oxidation potential of soil from the laboratory soil columns is presented by horizon in T able 4. . . . The average CH 4 oxidation potential measured from the top three horizon of all co lumns [0 to 15 cm] significantly exceeded that of the bottom three horizons [15 to 30 cm] (p <0.001), where O 2 was more limited (Table 1).”); Kightley et al., supra note 7, at 597-600 (concluding that “our data show that soil microbial community adapts rapidly to the presence of el evated CH 4 concentrations and can effectively reduce emissions of CH 4 from the surface of landfill soil. The capacity for CH 4 oxidation in soil is related to the depth of O 2 penetration and to the nutrient status of the soil, which may regulate the extent to which the methanotrophic community can develop”); Scheutz and Kjeldson , “Capacity for biodegradation of CFCs and HCFCs in a met hane oxidative counter-gradient laboratory system simulating landfill soil covers,” Environmental Science and Technology, 37: 5143-5149, 5146 (2003) (“Vertical soil gas profiles sh owed that both methane and oxygen were often present between 20 - and 40-cm depth. From 60-cm depth, the soil gas consisted of almost pure LFG – with only very low or no o xygen present.”); Wilhusen et al ., “Long-term behavior of passively aerated compost methanotr ophic biofilter columns,” Waste Management, 24: 643-653, Figure 3, 647 (2004) (showing the change in CH 4 concentration at various depths and demonstrating that gas concentration typ ically begins to decline (indicating methane oxidation is taking place) at a depth of 40 cm).20 1227842_1

concluded that the “methane emission rate in landfill covers is controlled by the interrelation among the soil physical properties such as gas filled poro sity, organic content and moisture; microbiological factors such as temperature, and substrat e availability; and the presence or absence of a gas extraction system. Because the emiss ion rate is controlled by these variables, it necessarily reflects the interplay of these processes .” 2012 SWICS Addendum at 16. Therefore,

careful review of the literature bears the conclusion that the rate of methane flux into cover is the

most accurate determinant of methane oxidation. Furtherm ore, such conclusion is informed by the well-established fact that the methanotrophic bacteria that are responsible for the methane oxidation process are more effective at lower flux rat es. C. The Imposition of an Arbitrary 24-Inch Cover Requirement Will Result in Inaccurate Reporting of GHG Emissions Not only is the 24-inch soil cover requirement unsupported by t he scientific literature, but such requirement will lead to significant over-estimati on of GHG emissions at many landfills that do not have 24 inches of cover over a majority of their sites, and thus a general misrepresentation of the relative significance of this class of greenhouse gas emitters. As EPA has properly recognized throughout the development of the F inal Rule, the 10% oxidation fraction is biased low. In fact, the limitation of t he 10% default fraction was even recognized by the author of the 1996 study that EPA relied on to establish t he original GHG Reporting Rule’s oxidation default value. Indeed, that study concluded that, “[w]e have presented a quantitative study of the primary factors influencing microbial oxidation of CH4 in the surface soils of

landfills. The model estimate of annual whole landfil l oxidation of 10% is consistent with the current low range of oxidation estimates. However, the dominance of temperature as a primary influencing factor and the mid-latitude climate of the st udied landfill implies that annual whole landfill oxidation rates in warmer climates, under simi lar conditions, would be significantly21 1227842_1

higher than estimates for this site.” Czepiel et al. at 16,728. A review of the more comprehensive literature on which the binned approach was base d confirms that oxidation factors of less than 10% are rare. For example, of t he 90 methane oxidation fractions in the SWICS Addendum, only six were below 10%. See 2012 SWICS Addendum, Table 2 at 3-8. Further, oxidation fractions greater than 10% were observ ed at all cover depths, including those less than 24 inches, demonstrating that 24 inches of cover i s not a prerequisite for methane

oxidation fractions that are consistent with the binne d approach. Instead, as concluded in the 2012 SWICS Addendum, methane flux is the key variable for det ermining oxidation fractions.

Id. Thus, based upon the data in the record, the Agency has no t demonstrated and the scientific studies do not support the notion that landfil ls with soil depths of less than 24 inches will be unlikely or unable to achieve oxidation rates of o ver 10%. D. Effect of Soil Cover Requirement On WM Landfills

EPA’s erroneous inclusion in the Final Rule of the 24-i nch soil cover requirement as a prerequisite to use of the binned approach to methane oxidation will affect many WM landfills’ reporting procedures and results. As noted above, WM curren tly reports emissions for 240 MSW landfills. Many WM active landfills that operat e primarily under intermediate cover will not be able to demonstrate compliance with a 24-inch depth of soil cover. However, based on calculated methane flux rates, and without the imposit ion of a 24-inch soil cover requirement, almost all of WM’s reporting landfills would have been able to use 25% or 35% methane oxidation rates under the binned approach, as proposed in the P roposed Rule. Specifically, under the Proposed Rule, only 9 of WM’s re porting MSW landfills would default to the 10% oxidation fraction, whereas 173 sites wo uld be in the 25% bin, and 58 sites22 1227842_1

would be in the 35% bin. In other words, a full 96% of WM’s reporting landfills would be able

to utilize oxidation fractions in excess of 10%. However , with the Final Rule’s 24-inch soil cover requirement, only 74 sites will benefit from the bi nned approach and 157 sites that would

otherwise fall within the 25% or the 35% bins will be forc ed to use the 10% oxidation fraction – despite the fact the literature plainly establishes that such sites are likely to have oxidation fractions well in excess of 10%. By way of example, us ing only the formula, Butterfield Landfill in arid Arizona with an active gas collection system wo uld be able to utilize a 35% oxidation fraction were it not for the 24-inch soil cover requir ement. Similarly, Hickory Hill Landfill 9 in South Carolina, a wet site also with active gas colle ction system, would be able to use a 35%

oxidation rate in the absence of the 24-inch soil cover requirement. In yet another example,

Dafter RDF 10 in Michigan, a temperate site with no gas collection s ystem, would be able to use a

35% oxidation rate in absence of the 24-inch soil cover re quirement. 11 Permitting these landfills, that do not meet the 24-inc h soil cover requirement, to utilize the binned approach, is scientifically appropriate. First, as a general matter, the high levels of collection efficiency realized at many WM landfills r esult in generally low methane flux rates, which are consistent with higher oxidation fractions. S econd, while intermediate cover requirements generally do not require the placement of 24 i nches of soil, the purposes served by intermediate cover are equally suited to ensure the avai lability of methane oxidation. Oxidation fractions significantly higher than 10% have been measure d at landfills with less than 24 inches of cover, including in areas with daily cover (six inch es). Further, as noted above, many

scientific studies have concluded that maximum oxidation o ccurs close to the surface of the

9 Hickory Run Landfill is owned and operated by Waste Mana gement of South Carolina, Inc. 10 Dafter RDF is owned and operated by Waste Management of Michigan, Inc. 11 The examples and figures included in this paragraph are base d on WM’s 2011 GHG Reporting Rule data.23 1227842_1

landfill at depths of less than 18 inches. See footnote 8. In short, at WM landfills, there is no basis to believe that a 10% default oxidation factor, whi ch WM would be forced to use under the Final Rule, will represent an accurate accounting of emis sions. By contrast, as amply supported in EPA’s record and the study data included therein, such fa ctor likely would not be representative of available data for varying cover depths. That the 24-inch soil cover requirement will result in inaccurate reporting is best demonstrated by analysis of the Lancaster Landfill 12 located in California, one of the sites that was a subject of the scientific literature referenced i n the 2012 SWICS Addendum. The

Lancaster Landfill is located at an arid site in Sout hern California and has an active gas collection system. Under the oxidation binned approach it would utilize a 35% oxidation factor.

This is consistent with Lancaster’s actual oxidation val ue, which was conservatively determined to be an average of greater than 34%, 13 with a low methane flux rate ranging from 0.90 g

CH 4 /m

2 /d to 3.96 g CH 4 /m 2 /d. 14 . However, as an active landfill, it is primarily un der intermediate cover of less than 24 inches and thus, under the Final Rule, would have to use the

default oxidation fraction of 10%. V. Proposal For Reconsideration A. A Soil Cover Prerequisite Is Neither Necessary Nor Ap propriate for Use of the Binned Approach Pursuant to federal law, all MSW landfills will necess arily have at least six inches of cover over a majority of the landfill, consistent w ith minimum requirements for daily cover.

12 Lancaster Landfill is owned and operated by Waste Managem ent of California, Inc. 13 Chanton et al. , “Landfill Methane Oxidation Across Climate Types in the U.S.,” Environmental Science & Technology, 45: 313-319, Table 2, 316 (2011). 14 Goldsmith et al. , “Methane emissions from 20 landfills across the Unite d States using vertical radial plume mapping,” Journal of the Air & Waste Managem ent Association 62: 183-197, Table 2 (Location C5), 192 (2012).24 1227842_1

40 CFR § 258.21(a). Hence, even without inserting any minimum c over depth requirement,

there will never be a situation in which either the de fault or the binned approach will be used at a landfill with “no” cover. Therefore, WM recommends that during reconsideration of the Final Rule, EPA remove the 24-inch soil cover requirement and allow all MSW landfills to make use of the binned approach without limitation based on cover dep th. This approach is consistent with the methane oxidation data, is consistent with the Pro posed Rule, and will allow for MSW landfills to more accurately report their GHG emissio ns based on site-specific factors influencing

methane flux.

B. If EPA Nonetheless Determines That a Soil Cover Prere quisite is Necessary For Use of the Binned Approach, EPA Should Use Intermed iate Cover As The Requirement While federal regulations set minimum technical criteri a for daily cover, 40 CFR § 258.21(a), and final cover, 40 CFR § 258.60(a), pursuant to Subtitle D of the Resource Conservation and Recovery Act, EPA has left to the st ates the determination of an appropriate intermediate cover for those portions of landfills whi ch do not receive waste on a daily basis but are not yet closed. That the States should set minimu m requirements for intermediate cover is appropriate inasmuch as the primary purpose of cover in ope rating landfills is to control disease, fires, odors, blowing litter, and scavenging, and the risks of each of these hazardous is dependent upon factors such as soil composition, humidity, and tem perature which vary across the country. If EPA believes, despite the lack of any demonstrated cor relation between cover depth and oxidation, that the binned approach must be restricted to l andfills meeting a minimum cover depth above six inches, then intermediate cover is a mo re appropriate and achievable restriction. A survey of 27 states in which roughly 77% of the reporting MSW landfills are located demonstrates that total intermediate cover depth will m eet or exceed 12 inches, which, as set25 1227842_1

forth above, is sufficient for oxidation fractions pre mised on methane flux under the binned approach. Further, this approach would provide a more accurate assessment of GHG emissions

than utilization of the default oxidation rate of 10%. As shown in Appendix “B,” if MSW landfills with interm ediate cover over a majority of area containing waste are permitted to use the binned approach, a great majority of these landfills will have a minimum of 18 inches of cover. For example, 21 states require intermediate cover (which is generally placed on top of the federally-requir ed six inches of daily cover) of 12 inches or more. Only six of the states require a minimum of 12 t otal inches of intermediate cover. Thus, if intermediate cover is used as the defining criteria i n lieu of 24 inches, reporting MSW landfills using the binned approach will generally have in excess of 12 i nches of cover. Further, identifying intermediate cover as the “gatekeeper” serves the purpose of ensuring that landfills that do not meet the requirement will n ot improvidently use the binned approach. That is, because intermediate cover requirements are al ready in place and monitored in order to comply with state laws and permits, landfills will nec essarily be able to assure themselves and establish for EPA, if necessary, that the requisite c over thickness is achieved. Conversely, although active landfills may, for various reasons, ma y utilize more than 24 inches at portions of their landfills, it is logistically difficult for s uch landfills to verifiably demonstrate whether the majority of waste-containing area meets the proposed 24-inc h cover depth. For these reasons, WM proposes that, if EPA declines to remove the cover requirement entirely, then it should replace the 24-inch soil cover requirement with a requirement for intermediate cover as a prerequisite to use of the binne d approach.26 1227842_1

VI. Conclusion For the reasons set forth herein, WM requests that the Agency commence a proceeding to reconsider the Final Rule pursuant to Section 307(d )(7)(B) of the CAA, 42 U.S.C. § 7607(d)(7)(B). WM appreciates EPA’s consideration of this Petition and would be glad to provide additional information in support of the Pe tition as may be necessary.

Carter Lee “Kerry” Kelly, Director Federal Public & Regulatory Affairs27 1227842_1 

## Figure 1 Plot Showing Relationship between Methane Fraction O xidized and Cover Thickness

n=32, number of measurements out of a total of 95 in list of SWICS references that reported cover thickness (some data points overlap and appear to be a single point) R 2 =0.072, correlation coefficient or percentage of results where oxidation can be explained by cover thickness. A value of 0.07 is very low, essentially showing no correlation between the two variables. r=.269 DF=30, the two-tailed p value describing fit to the linea r model equals 0.137, which also demonstrates lack of correlation between the two variabl es. By conventional criteria, a p value this high is considered to be statistically insignificant. A value for p=0.05 or 1/20 chance is the standard boundary between statistical significance and st atistical insignificance. y = 0.0023x + 0.2614 R 2 = 0.0724

0.00 0.20 0.40 0.60 0.80 1.00 1.20

0 20 40 60 80 100 120 cover thickness, cmfraction oxidized n = 32 p = .137 no significant relationship.1 

## Appendix A

May 16, 2013 Via Electronic Transmission: MRR_Corrections@epa.go v Docket ID No. EPA-HQ-OAR-2012-0934 Ms. Carole Cook Office of Atmospheric Programs, Climate Change Divi sion U.S. Environmental Protection Agency (6207-J) 1200 Pennsylvania Ave., NW Washington, DC 20460 Re: Comments Regarding Docket ID No. EPA-HQ-OAR-201 2-0934

Dear Ms. Cook:

Waste Management (“WM”) is pleased to offer the fol lowing comments on the United States Environmental Protection Agency’s (“EPA’s” or “Agen cy’s”) Proposed 2013 Revisions to the Greenhouse Gas Reporting Rule and Proposed Confidentiality Det erminations for New or Substantially Revised Data Elements (hereinafter referred to as the “Technical Corrections”) 78 Fed. Reg. 19,802 (April 2, 2013). WM is the leading provider of comprehensive waste a nd environmental services in North America. We are also a leading producer of renewable, waste-bas ed energy – enough to power nearly 1.2 million homes each year. Headquartered in Houston, WM oper ates in 48 states in the U.S. and most Canadian provinces. Our network of operations includes 390 collection operations, 352 waste transfer stations, 125 recycling facilities for differing commodities, 36 organic composting and processing facilities, 2 66 active landfill disposal sites, 131 landfill gas-to -energy projects, 17 waste-to-energy (WTE) plants, and five independent power production plants (operation s as of January 2012). The size, number and diversity of our operating fac ilities, as well as the nature of our business acti vities, makes reporting our GHG emissions a time-consuming and far more complex task than for many entities. WM has gained considerable experience wi th implementing the Mandatory GHG Reporting Rule (GHG MRR) over the last three years for over 2 00 active and closed Municipal Solid Waste (MSW) landfills we own or operate, 17 WTE facilities and 4 independent power plants owned or operated by Wheelabrator Technologies Inc., a wholly owned subs idiary of WM.

Overall, we commend the EPA for proposing technical corrections to the methods for estimating MSW landfill methane emissions, and monitoring methane concentrations based on peer-reviewed science and abundant site-specific technical data provided to the Agency. The corrections will enhance accura cy of landfill emissions reporting while reducing the monitoring burden for reporters. EPA’s careful2

analysis of peer-reviewed literature and numerous p eer-reviewed field measurement studies resulted in proposed changes to estimating methane oxidation in landfill cover. These changes will make greater use of site-specific conditions rather than nationa l default assumptions, which will improve the reliability of emission estimates. We support EPA’s proposed approach to replacing the single, default methane oxidation value with a more realistic and r epresentative methodology for deriving methane oxidation based on site-specific data. WM also supports the Agency’s proposal to reduce th e requirement to measure methane concentration at each landfill gas control device f rom weekly to monthly. Data from the first two years of GHG reporting from both private and public landfills demonstrate that reducing the frequency of methane concentration monitoring from weekly to monthly does not affect the accuracy of reported emissions. In fact, the data shows that the signif icantly higher costs associated with conducting wee kly monitoring and recordkeeping do not provide concomi tant benefits of improved data accuracy or reliability. The proposed change to monthly monito ring frequency will also align the GHG MRR with monitoring requirements in the existing New Source Performance Standards for MSW Landfills (see 40 C.F.R. 60 Subpart WWW).

While WM believes that EPA has made some significan t enhancements to the GHG MRR, we do have specific concerns, detailed below, regarding the ma nner by which EPA will implement the proposed increase in the global warming potential (GWP) for methane from 21 to 25, including the Agency’s proposal to apply the new GWP to prior years’ facil ity emissions reports. The proposed GWP increase for methane will disproportionately affect the MSW Landfill sector, which comprises both private companies and numerous local governments. The cost /benefit analysis performed (see docket ID No. EPA-HQ-OAR-2012-0934-0022, herein referred to as th e “Impact Analysis”) to assess the effects of the revised GWP on the landfill sector significantly un derestimates the number of newly subject MSW Landfills, incorrectly assumes that closed landfill s would not become newly subject to reporting requirements, and significantly underestimates the new costs of compliance. Below, we provide detailed comments on key aspects of the Subpart A g eneral rule provisions, Subparts C and HH.

Subpart A

EPA Should Apply Revised GWPs on a Prospective Basi s WM does not oppose the Agency’s proposal to revise the GWPs in Table A-1 to conform to the UN Intergovernmental Panel on Climate Change (IPCC) Fo urth Assessment Report (AR4). The U.S. has committed to submitting its National GHG Inventory for 2015 and future years using the GWPs published in the AR4. However, consistent with that commitment, WM suppor ts the Agency’s use of the revised GWPs to calculate facility emissions so lely on a prospective basis, once it finalizes and publishes these Technical Corrections. As described below, WM believes that the retroact ive application of the GWP values to the GHG reporting rule and/or other potentially affected programs3

such as the Prevention of Significant Deterioration (“PSD”) or Title V permitting programs would be inappropriate from both a policy and legal perspect ive. WM supports the Agency’s proposed use of a 100-year timeframe for GWPs consistent with the IPCC’s AR4 and the UNFCCC reporting guidelines for annual inventories. Furthermore, we support EPA’s statement that it is not the Agency’s intent to rev ise GWPs each time new data are published. (78 FR 19808) We agree with the EPA that it is vitally im portant that reporters have consistent and predicta ble requirements to avoid additional compliance burden and costs. Further, it is important for stakeholde rs who use GHG MRR information to have access to accur ate emissions estimates based on comprehensible and consistent information from year to year. The Agency’s plan to change prior facili ty emissions reports will undermine both goals.

Retroactive Application of the Revised GWP Values i s Unwarranted and Will Impose Unnecessary Burden on GHG Reporters:

WM objects to the retroactive revisions to GHG repo rts based on the proposed GWP values, because such revisions would be unnecessary and unduly burd ensome for GHG reporters. We understand that under the UNFCCC guidelines for national inventorie s, EPA is required to recalculate national emission s when emission factors or other methodological appro aches change. However, the GHG Reporting Program is independent of the national inventory, a nd should not be bound to that practice. Furthermore, the Agency’s rationale that retroactiv e changes to facility emission reports will assist the Agency with its national inventory is weak in light of the very different methods used to estimate national and facility emissions. As EPA has acknow ledged, it calculates the national GHG inventory us ing top-down national energy data and other national st atistics. But, the national data is not “broken-do wn at the geographic or facility level.” 74 Fed Reg. 16455. To the extent facility-level emissions repo rted under the GHG MRR are used to validate or improve t he national inventory, EPA can make appropriate updates in the context of the national inventory. It is not necessary to revise retroactively all fac ilitylevel emissions that were reported properly under t he existing rule.

EPA’s Intent to Apply Revised GWPs on a Retroactive Basis is Inconsistent with the Goals and Scope of the Overall Proposal : While the Agency is proposing to make retroactive c hanges to facility emissions using revised GWPs, which for MSW landfills will increase facility emis sions by about 20 percent, EPA is **not** proposing to recalculate facility emissions to reflect other cha nges to reporting methodologies. WM is concerned that this inconsistency in approach will fail to pr ovide accurate or meaningful data in the overall co ntext of the Technical Corrections. For example, the Age ncy’s Technical Corrections include changes to refi ne methane oxidation rates at landfills from 10 percen t to 25 or 35 percent, which could significantly reduce estimates of landfill methane emissions. Ye t the Agency has not proposed to make retroactive changes in facility emissions to reflect these refi ned methodological changes. Accordingly, the Agenc y’s intent to make retroactive changes to facility emis sions based on GWP is internally inconsistent with the overall scope of the proposed rule changes, and ref lects an arbitrary selection of particular revision s to4

apply on a retroactive basis. The revised GHG emis sions data will have little value if revisions addr ess one change (e.g., GWP value) but not others (e.g., methane oxidation rates).

Retroactive revision of GHG emission data will also burden GHG reporters because they will be forced t o either recalculate emissions (under Option 1) or va lidate the Agency’s calculations (under Option 2). In addition to the burden of recalculating prior years emissions, the retroactive revisions will create a great deal of confusion for stakeholders that rely on the GHG reports and raise questions about the validity of prior reporting efforts even outside of the mandato ry reporting requirement. For example, over the la st several years, companies such as WM have been at th e forefront of voluntarily reporting GHG emissions (using similar methods as required under the GHG re porting rule) and other sustainability metrics to a wide variety of interested stakeholders such as inv estors, suppliers, and/or customers. Revising the GWP values on a retroactive basis may also require revisions to numerous reports, plans, or even certifications that were prepared based on the best available information at the time. Such reports m ay now be considered inaccurate based on EPA’s retroac tive data changes. Companies would have a significant burden in trying to correct prior submi ssions or even verified certifications, and then communicating to stakeholders as to why those submi ssions have changed.

Because the retroactive application of the revised GWP values to prior year GHG emission reports is unnecessary, unduly burdensome, and confusing, WM urges the Agency to apply the revised GWP values on a prospective basis only. Specifically, WM supports EPA’s proposal to requi re existing GHG reporters to incorporate data changes into the 2013 calendar year report due as of March 31, 2014. Likewise, WM agrees that new reporters that will be subject to the requirements of Part 98 as a resul t of the proposed GWP revisions should not be requir ed to collect or report data until calendar year 2014, with the GHG report due as of March 31, 2015. 78 Fed. Reg. at 19833.

EPA Must Provide Clear Guidance in the Technical Co rrections that the Revisions to the GWP Values have No Retroactive Effect on PSD or Title V Permit ting: WM is deeply concerned over the lack of clarity pro vided by EPA with respect to the practical and/or legal effect of the revisions to the GWP values on regulatory programs such as PSD or Title V permitti ng. As the Agency knows, the GWP values are used by EPA and authorized states to determine the applicability of the PSD and Title V permitting pro grams. The Agency has made it clear that it is considering applying the revised GWP values to prio r reporting years under the GHG Reporting Rule. However, the Agency has provided almost no guidance as to whether the change to the GWP values and previously reported data would also affect prior PS D and Title V determinations. The preamble to the Technical Corrections ambiguously provides that EPA will “work with permitting authorities and other stakeholders as necessary to provide guidance” on q uestions regarding PSD and Title V applicability. 78 Fed. Reg. 19802, 19809. This statement provides no direction to either the states or the regulated public with respect to the legal effect of EPA’s ru le changes, or EPA’s intentions for the manner in w hich the proposal may affect important regulatory progra ms.5

EPA’s vague statements with respect to PSD and Titl e V permitting create a tremendous amount of uncertainty for the regulated community. By failin g to clarify the legal effect of the revisions to t he GWP values on the PSD or Title V programs, EPA has crea ted the potential for significant confusion with respect to the status of certain GHG reporters rela ting to PSD and/or Title V. This concern is substa ntial for facilities within the municipal waste landfill sector, which will be subject to an approximate 20% increase in GHG emissions as a result of the propos ed GWP revision, and is expected to have the most new GHG reporters as a result of the rule. Moreov er, EPA’s failure to clarify the effect of the prop osal on existing facilities may leave open the possibili ty for agency enforcement action, a citizen suit, a nd/or the reopening of a previously approved permit. WM is not aware of any precedent under the Clean Ai r Act that would require existing facilities to app ly new standards or emission factors retroactively, or that would subject existing facilities to regulato ry requirements based on such retroactive application. In this context, for example, EPA must clarify th at prior permit determinations should not be reopened or collaterally attacked based on revised (increased) GHG emission estimates. If emissions f rom a non-Title V facility would increase above maj or source thresholds as a result of the GWP revision, the transition to Title V status may not be deemed to have occurred at any point prior to EPA’s promulgat ion of the proposed rule. Likewise, to the extent that a non-PSD source would exceed PSD major source thresholds as a result of the GWP revision, such status may only be applied prospectively. Most imp ortantly, modification projects undertaken prior to the GWP revision may not be reopened on the basis o f changed emission estimates or PSD status, and the Tailoring Rule PSD requirements may only apply to modification projects that occur after the rule revisions. Under no circumstances should any calcu lated increase in GHG emissions resulting from the proposed GWP revisions be interpreted for regulator y applicability purposes to constitute or relate to a facility modification.

Given the legal precedent regarding retroactive rul emaking, EPA could not have intended that the PSD/Title V implications of the proposed rule would be retroactive. Specifically, the U.S. Supreme Co urt has consistently made clear that retroactivity is n ot favored in the law. **Bowen v. Georgetown Univ. Hosp**  ., 488 U.S. 204, 208-209 (1988). Absent an express statutory grant, courts generally will not find that an agency rule has retroactive effect. The ge neral disfavor of retroactivity is based on considerations of fair notice, reasonable reliance, and settled expectations, all of which are applica ble considerations in the current context. **Landgraf v. USI Film Products** , 511 U.S. 244, 270 (1994).

In determining whether a regulation has retroactive effect, courts consider “whether it would impose new duties with respect to transactions already com pleted.” **Id** . at 280. Courts have distinguished between regulations that impose new sanctions on pa st conduct, which are invalid unless specifically authorized, and regulations that merely "upset expe ctations," which are invalid only if arbitrary and capricious. **Nat'l Petrochemical & Refiners Ass'n v. EPA** , 630 F.3d 145, 159 (D.C. Cir. 2010). These two categories are generally referred to as "primary" a nd "secondary" retroactivity, respectively.

Applying these principles to the Technical Correcti ons, the retroactive application of PSD or Title V would be considered as having “primary” retroactive effect because it would impose new sanctions on6

past conduct (e.g., construction/modification witho ut a PSD permit). As such, the rule would likely b e challenged and struck down because the Clean Air Ac t does not authorize EPA to implement rules with primary retroactive effect. **Sierra Club v. Whitman** , 285 F.3d 63, 68 (D.C. Cir. 2002). Because of the lack of clarity, and to avoid legal challenges that will delay and encumber the rulemak ing, WM requests that the Agency explicitly provide in t he Technical Corrections that the revisions to the GWP values would not retroactively apply to PSD, Ti tle V, or any other regulatory program that relies on the GWP values. By contrast, the GWP revisions may only apply prospectively, in a manner that provides clear notice to affected facilities with r espect to the manner in which the revisions will be implemented and the legal effect of the revisions o n related regulatory programs.

One approach that EPA could take to address these c oncerns would be to establish two different tables in the regulations that would be used to determine PSD/Title V applicability depending on the date. F or example, the existing Table A-1 to subpart of part 98 would be used to determine GHG emissions under sections 51.166, 52.21, 70.2, and 71.2 until the ef fective date of the rule, and a new Table A-1(a) containing the revised GWP values would then be use d to determine GHG emissions after that date. This approach would be similar to the biogenic defe rral rule where EPA amended sections 51.166, 52.21, 70.2, and 71.2 to provide that prior to a date cert ain (July 21, 2014), the mass of GHG emissions shal l not include biogenic emissions. For pending permit app lications, if the application has been determined t o be administratively complete by the effective date of the rule, then the applicant would not be requir ed to revise emissions using the revised GWPs. This a pproach has been used by the Agency in its 2012 PM2.5 NAAQS PSD implementation determination that g randfathered existing permits. 15

. Likewise, EPA could require facilities renewing or modifying existing permits after the effective date of the Technical Corrections to update GHG emissions using the revised GWP values. EPA must clarify, however, that such application submittals would not be considered modifications that would themselves trigger PSD Tailoring Rule requirements.

15 In early 2013, EPA issued the Final Rule, National Ambient Air Quality Standards for Particulate Matt er, 78 Fed. Reg. 3086 (Jan. 15, 2013). This rule strengthened the annual PM2.5 standard to 12 μg/m3 and retained the 24- hour PM standard at a level of 35 μg/m3. The exist ing annual standard, 15.0 μg/m3, was set in 1997. Grandfathering of existing permit applications also is addressed in the new rule. Traditionally, 40 C .F.R. §§ 52.21(k)(1) and 51.166(k)(1) require that PSD permi t applications include a demonstration that new major stationary sources and major modifications will not cause or contribute to a violation of any NAAQS that is in effect as of the date the PSD permit is issued. However, in this rule, EPA grandfathered existing permit applications from demonstrating compliance with the new NAAQS for PM2.5 if the (a) the application is determined to be complete by December 14, 2012, or (b) the public notice on the draft permit or prelim inary determination is published before March 18, 2013 (t he day the revised PM2.5 standards become effective ). http://www.gpo.gov/fdsys/pkg/FR-2013-01-15/pdf/20 12-30946.pdf7 EPA did not Accurately Assess the Impact on MSW Lan dfills of Changing the GWPs

EPA’s technical corrections recognize that two of t he 42 subparts (Subparts W and HH), would bear the greatest adverse impact by the change in GWP. A de tailed analysis of the cost and economic impacts is included in EPA’s Impacts Analysis (docket ID No. E PA-HQ-OAR-2012-0934-0022). As described below, WM’s review of the Impacts Analysis indicates that EPA significantly underestimated both the number of newly subject Subpart HH MSW Landfills and the adde d costs of compliance imposed by these changes on both new and existing reporters.

First, the Impacts Analysis concludes that no close d landfills would be newly impacted by the change i n GWP and therefore, no closed landfills are included in the cost impact analysis. It is unclear how EP A reached this conclusion. Based on a review of our MSW landfills, WM identified several closed landfil ls with methane generations between 21,000 and 24,999 metric tons/year CO 2 e that could exceed the threshold due to the proposed revision of the GWP f or methane. Although emissions from these landfills are very low and will steadily decline, t hey would be pulled into the GHG MRR and required t o report for at least three to five years. In additi on, because they are closed, they do not generate revenue to offset new compliance costs, and would t hus face a significant impact. This situation is a lso likely to arise for small municipalities that own c losed facilities.

Second, we find that EPA has underestimated the cos t of complying with the reporting requirements under Subpart HH. Table 11 of the Technical Correct ions and Tables 4-1 and 6-16 of the Impacts Analysi s state the incremental annual cost impact for new Su bpart HH reporters is $309,700 or $5,434 per facili ty for the initial year of reporting and $137,500 or $ 2,413 per site in subsequent years of reporting, in 2011 US Dollars. Based on WM’s three years of reporting experience, the actual annual costs to comply with the monitoring recordkeeping and reporting requirem ents are four to five times higher than EPA estimates. WM submitted data on ongoing reporting costs to EPA on October 1, 2012. These data showed that the annual cost per landfill for subseq uent years of reporting was $11,412. This cost estimate does not include the cost of responding to EPA questions raised on facility reports that by r ule require a facility to respond within 45 days, and i f applicable, make corrections and re-submit report s. This cost can be significant depending on the natur e of the EPA inquiry. EPA also did not account for this as part of its Impact Analysis. In our previous su bmission to EPA, we also noted that WM’s costs per site is likely to be lower than for smaller companies or even municipalities because as a large company, we are able to take advantage of economies of scale in purchasing services and equipment.

Third, EPA failed to recognize that revised GWPs wi ll delay the date by which low-emitting MSW landfil ls can exit the reporting program. Subpart A of the G HG MRR includes provisions for facilities to exit t he reporting program once actual emissions fall below the 25,000 CO 2 e threshold for five consecutive years (see 40 C.F.R. 98.2(i)). The Impacts Analysis esti mates methane generation at a closed landfill decre ases 18% in 5 years, or 3.6% annually. However, an incr ease in GWP from 21 to 25 will increase modeled emissions by 20% and will therefore delay exit from the reporting program obligations by more than 5 years. Most closed landfills that report under the GHG MRR, yet are near the exit threshold, are required to estimate actual emissions based on meth ane generation (Equation HH-5). This is the case8

because the landfills cannot operate active gas col lection and control systems without augmenting the system with fossil fuel (e.g., propane) because the y produce such a low quantity of methane. These older, closed landfills, which are actually experie ncing decreasing emissions, will be adversely affec ted by the GWP value change and will be trapped in the program for a significantly longer time.

Fourth, the purpose of the change in GWP is to alig n with global inventory practices, not to broaden applicability of the GHG MRR. In the Preamble to t he technical corrections EPA clearly states, “The changes are being proposed for two reasons.....to ens ure consistency with the Inventory as the Inventory begins to use GWPs from the IPCC Fourth A ssessment Report. Second, we propose to add GWPs for F-GHGs that are not currently included in Table A-1...” (78 FR 19807).

Adding new reporters or delaying exit for existing reporters is not the intent of changing the GWP; ye t the collateral damage is significant for MSW Landfi lls. The methane emissions at MSW landfills have n ot changed. No physical or operational changes have o ccurred at the MSW Landfills. The change in GWP is simply a change in calculation; a change, noneth eless, that significantly impacts GHG MRR applicabi lity for Subpart HH reporters.

Both the technical corrections package and the Impa cts Analysis conclude that the change in GWP will not affect the cost of monitoring and recordkeeping and would not materially affect the cost for calculating emissions. This is incorrect. Such delay does have a direct financial impact for these facilities. Closed landfills do not generate revenue, yet the se facilities will incur additional annual compliance monitoring, recordkeeping and reporting costs solely due to the change in GWP.

WM’s Recommendations:

For the reasons previously described, WM does not s upport EPA’s proposal to apply the revised GWPs retroactively to previously submitted reports under the GHG MRR. If the Agency determines that some level of time series consistency is necessary; howe ver, WM urges the Agency to recalculate emissions for whole sectors (e.g., MSW landfills reporting un der Subpart HH) rather than recalculating individua l facility emissions . The newly recalculated emissions for aggregated sectors would more closely align with the national emissions inventory and would mit igate potential adverse regulatory complications.

WM also does not support the expansion of applicabi lity that will occur in the MSW Landfill sector due to the revision of the GWP for methane, and we note that there are other sectors (e.g., Subpart FF: Underground Coal Mines, Subpart NN: Natural Gas) th at are not facing this issue because their applicability threshold is not based on CO 2 e emissions. Requiring reporting from more very sm all landfills and requiring other very small closed lan dfills to continue reporting is costly and has limi ted policy relevance. We further note that the applica bility determination for MSW Landfills is already based on the methane generation level, which was co nverted to tons CO 2 e. Emissions of CO 2 from combustion have never been considered in determinin g applicability under the rule.9

Given the increased cost and limited utility of the se “side effects” of revising the GWPs, we recommen d that that EPA establish both a methane-based report ing threshold for Subpart HH to replace the CO 2 e based reporting threshold, and a methane-based requ irement for exiting the program. As noted below, these changes are easily implemented by simply esta blishing a methane reporting threshold of 1190 metric tons/year or more and by adding new language to clarify off-ramp provisions for both the fiveyear exit threshold (1190 metric tons CH 4 ) and the three-year exit threshold ( 714 tons metr ic tons CH 4 ). EPA could modify language in both “TABLE A-3 to Sub part A of Part 98 – Source Category List for § 98.2 ( a )(1) – Source Categories a Applicable in 2010 and Future Years” and Subpart H H, § 98.341 as follows:

TABLE A-3 

### to Subpart A of Part 98 Source Category List for § 98.2 ( a )(1) Source Category List for §98.2(a)(1) Source Categories a Applicable in 2010 and Future Years **“Municipal solid waste landfills that generate CH 4**  **in amounts equivalent to 25,000** 1190 **metric tons CO**  **2 e or more per year, as determined according to subp**  **art HH of this part.** As for exiting the program requirements, amend Sect ion 98.341 as follows:



### §98.341 Reporting Threshold (a) You must report GHG emissions under this subpart if your facility contains a MSW landfill and the facility meets the requirements of §98.2(a)(1) , except as provided for in (1) or (2) below. (1) If reported emissions are less than 1190 metric tons CH 4 per year for five consecutive years, then the owner or operator may discontinue complying with this part provided that the owner or operator submits a notification to the Administrator that announces the cess ation of reporting and explains the reasons for the reduction in emissions. The notification s hall be submitted no later than March 31 of the year immediately following the fifth cons ecutive year of emissions less than 1190 metric tons methane per year. The owner or operator must maintain t he corresponding records required under §98.3(g) for each of the five consecutive years and retain such records for three years following the year that reporting was dis continued. Unless the facility is no longer accepting waste, the owner or operator must res ume reporting if annual emissions in any future calendar year increase to 1190 metric tons methane per year or more. (2) If reported emissions are less than 714 metric tons CH 4 per year for three consecutive years then the owner or operator may discontinue complying with this part provided that the owner or operator submits a notification to the Administrator that announces the cess ation of reporting and explains the reasons for the reduction in emissions. The notification s hall be submitted no later than March 31 of the year immediately following the third consec utive year of emissions less than 714 metric tons methane per year for Subpart HH. The owner or ope rator must maintain the corresponding records required under §98.3(g) for each of the three consecutive years and retain such records for three years following the year that reporting was discontinued.10

Unless the facility is no longer accepting waste, the owner or operat or must resume reporting if annual emissions in any future calendar year increase to 1190 metric tons met hane per year or more. Subpart HH facilities would still calculate and rep ort methane as well as CO 2 e emissions for EPA inventory purposes but rule applicability and progr am exit provisions would be based upon methane emissions – not CO 2 e. The proposed exit provisions do not consider an cillary Subpart C anthropogenic emissions because MSW Landfills that meet the exit provisions are very small and primarily closed landfills, and they do not operate Subpart C device s. Subpart C emissions are either non-existent or at such negligible amount that by including these emis sions would not prevent a Subpart HH facility from exiting the program. Therefore, we believe reporte rs will not exit the program prematurely due to exclusion of Subpart C anthropogenic emissions.

The methane based reporting threshold allows the Ag ency to avoid increasing the reporting program burden for the MSW landfill sector and EPA staff. It would also prevent subjecting additional small a nd primarily closed landfills with negligible emission s to reporting requirements and new compliance cost s. Existing reporters will not be delayed five additio nal years or more from exiting the reporting progra m. It also allows EPA to meet national and global inve ntory program commitments without needlessly affecting GHG MRR applicability.

Subpart C - Stationary Fuel Combustion WM Supports Revised High Heat Value (HHV) and Emiss ion Factor revisions for Landfill Gas and Other Biomass Gases WM supports proposed changes to HHV for landfill ga s and establishment of HHV and emission factor for “other biomass gases.” The proposed changes mo re accurately reflect methane concentration of the two fuel types.

EPA Should Base Any Revisions to the Default Factor for Biogenic CO 2 Emissions from MSW Combustion on Actual Biogenic Fractions Reported by Industry

EPA should not revise the default biogenic CO 2 emissions factor for MSW combustion based on the questionable CO 2 emission factor estimate derived in the “ **Review and Evaluation of 40 C.F.R. 98 CO 2**  **Emission Factors for EPW07072 TO 45** ”(in Docket ID EPA_HQ-OAR-2012-0934). The analysis premises a change to a lower biogenic fraction based on the su pposition that the composition of MSW has changed significantly since the mid-1990s when the current biogenic emission factor of 0.60 or 60 percent was developed. However, the Agency analysis offers no data to support that supposition. Furthermore, EPA is now in possession of far more robust data upon w hich to base an analysis of the suitability of the existing biogenic emission factor used for the GHG MRR. The Agency should use the actual biogenic CO 2 fractions reported by all municipal waste combustor s (MWCs) for the first three years of the GHG11

reporting program (2010-2012). We understand that the Agency did not have this information available to it until this year as reporting of the biogenic CO 2 emission fractions was deferred. However, this information is now available to EPA and provides a far more scientifically defensible basis for making a proposed change, or for validating the existing fac tor. WM recommends these data be used to evaluate, and if appropriate, revise the default biogenic CO 2 emission factor in 40 C.F.R. 98.33.

WM’s 17 WTE facilities have collected and analyzed over 238 quarterly CO 2 samples to determine the biogenic CO 2 fraction using ASTM Test Methods D7459-8 and D6866 -08. With national data for the entire fleet of MWC facilities, EPA should have a t housand or more biogenic CO 2 fraction results reported for the last three years. These data will provide ample basis for the Agency to evaluate the need to revise the biogenic fraction for MSW.

WM Wheelabrator facilities’ annual average biogenic CO 2 fractions are provided in the table below. These data verify that average biogenic CO 2 fractions for MSW combustion are well above the 0.5 5 (55%) default value proposed by EPA. Analysis of W M’s reported data and that of the other MWCs may support an increased default emission factor above the current default value of 0.60 (60%).

We also strongly recommend that EPA incorporate use of the latest version of the ASTM test method for GHG reporting. The rule references ASTM Test Metho d D6866-08 in 40 C.F.R. 98.34 (d) for determining biogenic CO 2 fraction. This version is outdated by two years. The ASTM D6866 method was revised in 2010 (the first GHG reporting year) to incorporate a new correction factor used to account for excess radioisotope C 14 in the atmosphere from thermo-nuclear testing. In 2008, this correction factor was 0.93. In 2010, the correction factor was revised t o 0.95 in ASTM D6866-10. Using the most up-to-date method, the actual biogenic CO 2 fractions for WM’s MWCs (and the national fleet) w ould be higher for all three reporting years by 1% absolute as shown i n the table below. To ensure accurate biogenic CO 2 fractions are reported in future GHG reporting year s, 40 C.F.R. 98.34 (d) should be revised to referen ce ASTM D6866-10 or “latest version.” This would allo w the latest improvements in radio-dating of CO 2 to determine biogenic CO 2 to be automatically incorporated without a requisi te rule revision.12 

### WM Biogenic CO 2 

### Fraction Summary Plant State 2010 2011 2012 Concord NH 60% 55% 57% Claremont NH 59% 58% 56% Millbury MA 62% 60% 58% No Andover MA 61% 61% 60% Saugus MA 62% 60% 59% Bridgeport CT 64% 63% 62% Lisbon CT 61% 60% 58% Hudson Falls NY 64% 59% 59% Westchester NY 63% 63% 60% Falls PA 63% 61% 60% Gloucester NJ 62% 62% 59% Baltimore MD 62% 63% 61% Portsmouth VA 66% 62% 63% So Broward FLA 65% 63% 61% No Broward FLA 63% 63% 58% McKay Bay FLA 64% 63% 63% 64% 63% 61% Spokane WA 61% 61% 60% Mean All 62% 61% 60% ASTM D6866-10 64% 62% 61%

Subpart HH – MSW Landfills

WM Supports the Proposal to Replace the Default Met hane Oxidation Value with a Determination Based on Site-Specific Data

WM commends the Agency for proposing technical corr ections to Subpart HH that reflect the sitespecific influences affecting emissions of methane at MSW landfills. EPA’s proposal to replace the default, methane oxidation fraction of 10 percent w ith a more refined determination using site-specifi c data, will improve the accuracy of landfill emissio ns estimates. The Agency’s proposal to establish categorical values for methane oxidation based on e ach site’s methane flux rate is well supported by t he extensive peer-reviewed data provided by public and private organizations in the landfill sector. We appreciate EPA’s careful review of the technical li terature and field studies to develop and propose values for methane oxidation in landfill cover that more correctly reflect actual field measurements. This will allow for greater accuracy in estimating landfill emissions than will continued use of a nat ional default.13

The EPA’s Proposal to Revise the Methane Oxidation Factor is Well Supported by Peer-Reviewed Science :

Numerous studies have been conducted worldwide and referenced in the scientific literature that address and document methane oxidation in cover soi ls, as well as gas collection efficiency. In 2009, The Journal of Environmental Quality published a co mprehensive literature review 16 . The paper references over 60 technical documents dating from 1960 to the present, with the majority of the papers being published in the 1990s and 2000s. Ove rall, based on review of 42 determinations of the fraction of methane oxidized in a variety of soil t ypes and landfill covers, the mean fraction of meth ane oxidized across all studies was 36 percent with a s tandard error of 6 percent. For a subset of 15 stu dies conducted over an annual cycle, the fraction of met hane oxidized ranged from 11 percent to 89 percent with a mean value of 35 percent + 6 percent, nearly identical to the overall mean.

In July 2007, the Solid Waste Industry for Climate Solutions (SWICS) released its first white paper ti tled **Current MSW Industry Position and State-of-the-Prac tice on LFG Collection Efficiency, Methane**  **Oxidation, and Carbon Sequestration in Landfills** (White Paper). The public and private members of SWICS shared the White Paper with EPA as it develop ed the GHG MRR requirements for evaluating and reporting MSW landfill emissions. In January 2009, SWICS updated the White Paper to incorporate additional studies noted above.

Since the release of the 2009 White Paper, a number of studies have been published in peer-reviewed literature, most notably an entire special issue of the journal Waste Management (2011) on Landfill Ga s Emission and Mitigation sponsored by Consortium for Landfill Emissions Abatement Research (CLEAR). CLEAR is an International Waste Working Group (IWWG ) Task Group, which focuses on landfill gas emission to the atmosphere. The group has members from 12 countries, across four continents. A number of papers in the special issue focus on the use of compost biocovers, bio-windows or permeable gas dispersion layers to treat and oxidize landfill gas in situ (Huber-Humer et al., 2011; Pedersen et al., 2011; Scheutz et al., 2011; Pawlowska et al., 2011; Dever et al., 2011; and Jung et al., 2011). Additionally, several papers in the special issue, Ranchor et al., (2011); Abichou et al., (2011) and Chanton et al., (2011b), examined the response of t he methane oxidizing microbial community to methane loading to the cover soil. Two key papers, Bogner et al., (2011), and Spokas et al., (2011), describe recent work in California where field meas urements of emission and oxidation were coupled with extensive modeling efforts. Chanton et al., ( 2011a) published the results of 37 seasonal samplin g events at 20 landfills with intermediate covers ove r a four-year period. Abichou et al. (2011b) exami ned the best approach towards describing central tenden cies in oxidation data and reported that the result s were generally distributed normally so that mean va lues could be used.

16 Chanton, J.P, D.K. Powelson, and R. Green. 2009. M ethane Oxidation in Landfill Cover Soils, is a 10% Default Value Reasonable?. Journal of Environmental Quality , 38:654-663.14

In November 2012 SWICS, with the participation of D r. Jeffrey Chanton of Florida State University and Dr. Morton Barlaz of North Carolina State Universit y, finalized an addendum (2012 Addendum) to the Methane Oxidation section of the 2009 White Paper. The 2012 Addendum includes methane oxidation results from evaluations of 90 landfills as compare d to the 47 published evaluations available in 2009

. This 2012 Addendum also addresses the comments and questions EPA raised in its Response to Comments to the GHG MRR Final Rule issued October 2 0, 2009 (74 FR 56260):

First, EPA questioned the decision to calculate oxi dation values using the arithmetic means as opposed to the median values from the array of studies, bec ause it appeared that the means might be biased high. A more thorough discussion of this issue and inclusion of more recent literature are included i n the 2012 Addendum, and both median and mean values are provided. Second, EPA expressed some concern regarding the po ssible over-reliance on laboratory studies, which tend to yield higher oxidation fractions. Since re lease of the 2009 White Paper, governmental, academ ic and private researchers have made a significant num ber of additional field measurements, and these results are included in the addendum. Third, EPA noted that only five field measurements for clay soils were available during development of the 2009 White Paper. Since then, significant effo rt has been made to measure methane oxidation at landfills with clay soils; the 2012 Addendum incorp orates the results of 31 field studies. Fourth, the 2012 Addendum addresses the variation i n methane oxidation with the methane emission rate. In reviewing and incorporating the results of these peer-reviewed studies of landfill methane oxidatio n, the 2012 Addendum updated the 2009 White Paper resu lts as follows:

1. Clay cover: The number of studies in clay cover inc reased from five in 2009 to 31 in 2012. The mean fraction of methane oxidized increased from 18 percent to 30 percent, while the median fraction oxidized increased from 14 to 29 percent.

2. Sandy soils cover: The number of studies in sandy s oils doubled from eight to 16, with the mean oxidation value changing very little (55 to 54 perc ent) while the median value increased from 43 to 50 percent methane oxidized.

3. “Other” covers: The number of studies in “other” co ver soils increased by nine and both the mean and the median fraction oxidized values increa sed slightly.

4. The overall mean oxidation value across all of the studies increased from 35 to 38 percent while the overall median oxidation fraction increased fro m 31 to 33 percent.

The SWICS 2012 Addendum Definitively Supports a Sig nificant Increase to the Current Default Value of Ten Percent :15

The 2012 Addendum concluded that the EPA default ox idation value of 10 percent underestimates typical methane oxidation and is not representative of expected methane oxidation at sites utilizing organic, clay, sand or other cover types. EPA deri ved the default value from one field study performe d at one poorly maintained landfill with no gas colle ction system, Czepiel et al 17 . Analysis of the 90 studies highlighted in the 2012 Addendum indicates that if a single value is considered for methane oxidation it should be between 33 and 38 percent.

The 2012 Addendum also examined methane oxidation a s a function of methane loading to the cover layer of the landfill. Recent studies show that th e percent oxidation is an inverse function of the r ate of emission (Stern et al.,2007; Rachor et al., 2011; C hanton et al., 2011a,b). At lower emission rates, the methanotrophs in the soil cover can consume a large r portion of the methane delivered to them, potentially oxidizing 95 to 100 percent (Humer and Lechner, 1999, 2001a, Huber-Humer 2008; Powelson et al., 2006, 2007; Kjeldsen et al., 1997). As flu x rates increase, the percent oxidation decreases a nd the methanotrophs can become overwhelmed with methane. Thus, as methane emission increases, percent oxidation decreases (Powelson et al., 2006, 2007).

A mathematical model of cover oxidation developed b y Dr. Tarek Abichou of Florida State University (Abichou et al., 2010), demonstrates tha t at lower methane fluxes, oxidation rates are equal to the methane loading to the soil cover. Oxidation keeps pace with flux, and the soil cover is able to oxidize all of the methane coming from below. At lower loading rates, methane oxidation is equal to 100 percent. As flux increas es, the cover is not able to oxidize all of the incoming methane, and the percent oxidation falls o ff. Therefore, percent oxidation starts to decrease as the methane loading to the cover increa ses. This relationship is shown clearly in the laboratory column studies of Rachor et al., (20 11). Field studies have also confirmed this relationship between methane flux and percent oxida tion (Chanton et al., 2011a,b). At low rates of methane emission, the percent oxidation is near 100 percent. As emission rates increase, the percent oxidation decreases. This analysis serves to support the approach that EPA is proposing for determining a more accurate me thane oxidation fraction by calculating the methane flux rate for the landfill. In addition to the 2012 Addendum, the landfill sect or provided data for 262 private and public landfills reporting under Subpart HH. The dataset allowed the Agency to evaluate several possible options for determining more accurate meth ane oxidation fractions. The data conclusively showed that the average oxidation frac tions for different soil cover types are all well above the default 10 percent value required by Subpart HH, and underpin the need for a revised default value or more refined method for de termining an oxidation fraction at a site. WM strongly supports EPA’s proposal to allow report ers to determine methane oxidation by calculating the methane flux rate on a site-specifi c basis

..

17 Czepiel, P.M., B. Mosher, P.M Crill, and R.C Harri ss. 1996. Quantifying the effect of oxidation on la ndfill methane emissions. J. Geophys. Res. 101:16711-16719.16 WM Strongly Supports the Proposal to Require Monthl y Monitoring of Methane

EPA’s proposal to change the frequency of monitorin g from weekly to monthly will reduce burden for reporters without any loss of data relia bility or accuracy, and properly aligns the GHG reporting requirements with the federal and sta te operating performance standards for MSW landfills (Subpart WWW, 40 C.F.R. 60.756(a)). WM strongly supports the Agency’s proposal to requi re methane monitoring on a monthly rather than a weekly basis. The landfill sector provided EPA wit h 2011 reporting year methane monitoring data for 395 landfills (296 active and 99 closed). EPA eval uated the data and concluded that shifting from wee kly to monthly measurement frequency would increase unc ertainty of reported methane recovery values for a single landfill by only 2.5 percent with no s ignificant bias. The uncertainty for the nationwid e total of reported methane recovery for the sector would i ncrease only 0.1 percent. Thus , the Agency’s analysis of the extensive database definitively sup ports its proposal to reduce the frequency of methane monitoring. The proposal will greatly reduce the cost and bur den associated with reporting, while maintaining sufficiently reliable and accurat e data.

The Agency Should Eliminate the Requirement that Mo nthly Methane Measurements be Made Fourteen Days Apart

As noted above, WM strongly supports the Agency’s p roposal to require methane monitoring on a monthly rather than weekly basis. The propose d monitoring frequency will significantly reduce the cost and burden for reporters while main taining the same level of reporting accuracy and reliability. However, we recommend th at the wording of §98.343(b)(2)(ii) and (iii) be modified to eliminate the stipulation that month ly measurements (of methane, temperature and pressure) be at least fourteen days apart. Thi s creates unnecessary complexity to what should be a simple requirement to monitor LFG each calendar month. First, EPA’s analysis of three years of data provid ed for 395 landfills showed that there is very little variability in methane concentration across either weekly or monthly measurements. A requirement for a fourteen-day period between measu rements is pointless. Second, qualified personnel properly trained in ins trument calibration, sample measurement, and documentation procedures must be used to collec t the readings for QA purposes. The fourteen-day limitation significantly and unnecessa rily complicates scheduling of required personnel, particularly for control devices that op erate intermittently (a common occurrence). Third, for destruction devices that operate only in termittently (a common occurrence), it may not be possible to take a monthly reading at least fourteen days apart due to the operating schedule of the device. For example, if a device o nly operates for several days at the end of one month and the beginning of the next month, it w ould be impossible to acquire a reading for each month at least 14 days apart.17

We therefore recommend removing the following phras e from §98.343(b)(2)(ii) and (iii): **If only one measurement is made each calendar month , there must be at least fourteen days**  **between measurements.**

The Agency should Remove References to “Back-up Fla re or Similar Device” from the Definition of f Dest,

n The proposed revised definition of f Dest,n for Equations HH-6 and HH-8 includes a special prov ision when gas is destroyed in a “back-up flare (or similar de vice).” This distinction is an artifact of the ori ginal rule and is no longer necessary because the proposed rev isions to HH-6 and HH-8 properly account for multiple control devices regardless of the amount o f time any given control device operates during the year, or whether it is considered a primary or back up device. WM recommends simply deleting **“is destroyed in a back-up flare (or similar device) or**  **if the gas is”**

from the definition of F Dest, n .

The Agency Should Clarify the Rule with a Technical Correction to the Bulk MSW DOC Value in Table HH-1 Earlier this year, EPA released a helpful Frequentl y Asked Question (FAQ) and response that clarified reporter’s ability to use a more precise approach f or choosing appropriate DOC value for various types of waste streams disposed at the facility in additi on to bulk MSW (FAQ 744). The Agency clarified tha t sites that receive separate inert waste shipments, may use the appropriate DOC value for those waste streams listed in Table HH-1 under the “Waste compo sition option.” At the same time, reporters may select the appropriate DOC value for bulk waste (0. 2) found under the “Bulk waste option” section of Table HH-1 for shipments of bulk MSW. We agree with the interpretation presented by this FAQ and request that the EPA formalize this FAQ response by adding the bulk waste DOC value of 0.2 to the list of various wastes under the “Waste composition option” section of the Table HH-1.

WM Recommends the Agency Not Revise Equation HH-1 t o Incorporate a DOC that Varies by Year in which Waste is Placed In the preamble to the draft technical corrections, the EPA notes that the DOC variable is intended to be a function of the year waste is placed in the landf ill. As currently written, the DOC term is a funct ion of the waste type, and is not a function of the dispos al year. The Agency requests comment on the need t o revise Equation HH-1 and the definition of DOC to a llow DOC to be a different value for different year s that a waste is placed in the landfill. While it may be possible to revise Equation HH-1 to use a DOC which varies by year, we believe the practice would be far too cumbersome to be practica l. In theory, such a model would work in a manner18

similar to the current Waste Composition method, wh ich has multiple DOC factors. The eight model results are then summed to determine total methane generation. In theory, the same approach would work for multiple DOC factors, but the practice wou ld become arduous. Each model for each DOC would have to be retained for all subsequent report ing years. If only one DOC is used each year, a facility is still required to maintain 10 models af ter 10 years of reporting. If a facility determine s DOC for multiple streams of waste, the burden will only inc rease. In the case of landfills projecting closure decades in the future, the burden of maintaining po tentially hundreds of models would be vast. Waste Management appreciates the opportunity to pro vide you with our comments and recommendations, and we look forward to continuing to work with you as you finalize revisions to the GHG MRR. Should you have any questions about these comments, please feel free to call me at 202- 639-1218 or e-mail me at kkelly5@wm.com. Sincerely,

Kerry Kelly, Director Federal Public & Regulatory Affairs

cc: Rachel Schmel

## Appendix B

Summary of Select State-Level Regulatory Requirements

for Thickness of Intermediate Cover

State Minimum

Intermediate Cover Thickness (inches) Number of

Landfills Pertinent Regulatory Citation(s)

Arkansas* 12 18 A RK

. C ODE R.§ 22.413(c)

California 12 113 C AL

. C ODE R EGS

. tit. 27, § 20700(a)

Colorado 12 21 6 C OLO

. C ODE R EGS

. § 1007-2. 1.2, 2.1.10

Florida 12 51 F LA

. A DMIN

. C ODE A NN

. r. 62- 701.200(55), 62-701.500(7)(g) Georgia 12 52 G A

. C OMP

. R. & R EGS

. 381-3-4.07(3)(g)

Illinois 12 63 I LL

. A DMIN

. C ODE tit. 35, § 807.305(b)

Indiana 12 34 329 I ND

. A DMIN

. C ODE 10-20-14(f)

Kansas 12 15 K AN

. A DMIN

. R EGS

. § 28-29-108(c)(1)

Kentucky* 12 25 401 K Y

. A DMIN

. R EGS § 48:090(2)

Maine 18 4 06-096-401 M E

. C ODE R. § 4(C)(8)(b) Michigan* 12 52 M ICH

. A DMIN

. C ODE r. 299.4429(6)

Minnesota 12 16 M INN

. R. § 7035.2815(B) Mississippi 12 16 A PPLICATION FOR P ERMIT OF A N EW OR E XPANDED M UNICIPAL S OLID WASTE L ANDFILL ; M ISSISSIPPI D EPARTMENT OF E NVIRONMENTAL Q UALITY AT §8(11)

Missouri* 12 24 M O

. C ODE R EGS

. A NN

. tit.10 § 80-State Minimum Intermediate Cover Thickness (inches) Number of

Landfills Pertinent Regulatory Citation(s)

3.010(17)(C)(2)

Montana 12 9 M ONT

. C ODE A NN

. § 17.50.1104(2)(c) New Jersey 12 20 N.J. A DMIN

. C ODE § 7:26-1.4, 2A.8( B )(10)

New Mexico 12 8 N.M. C ODE R. § 20.9.5.9( O )

New York 12 37 N.Y. C OMP

. C ODES R. & R EGS

. tit. 6, § 360-1.2(91), 360-2.17(d)

North Carolina 12 42 13B NC. A DMIN

. C ODE § 0500.0505(3)(b), 1600.1626(2)(c)

Ohio 12 51 O HIO A DMIN

. C ODE 3745:27-19(G)(2)

Oklahoma* 18 26 O KLA

. A DMIN

. C ODE § 252:515-19-52(a) Pennsylvania 12 48 25 P A

. C ODE § 273.233 (c)(1)

South Carolina 12 22 S.C. CODE ANN. REGS. 61- 107.19(E)(7)

Tennessee 12 29 T ENN

. C OMP

. R. & R EGS

. 0400-11-01-.04 (6)(a)(4)

Texas 12 96 30 T EX

. A DMIN

. C ODE § 330.165(c) Virginia* 12 41 9 V A

. A DMIN

. C ODE § 20-81-140(B)(1)(d) Wyoming* 18 2 W YO

. C ODE R. § C H

. 2, S EC

. 5(r) *Includes daily cover Total Number of Landfills: 935 Percentage of GHG Reporting Landfills: 76.82% (935 out of 1217)