Comments Regarding the Environmental Protection Agency’s 

Guidance for Determining Best Available Control Technology for Reducing Carbon 

Dioxide Emissions from Bioenergy Production (March 2011) 

To the extent that biogenic CO2 emissions have unique lifecycle characteristics that 

warrant different treatment under the Clean Air Act (“CAA”) from other pollutants, these 

characteristics cannot form the basis of a broad exemption from PSD and Title V 

permitting. Rather, biomass feedstocks and the resulting CO2 emissions must be 

analyzed in the context of facility-specific, case-by-case best available control technology 

(“BACT”) determinations. These comments address the appropriate treatment of CO2

emissions from the combustion of biomass in BACT determinations. Appropriate 

treatment of biomass in the BACT process is critical to achieving the real greenhouse gas 

(“GHG”) emissions reductions necessary to combating climate change. 

EPA released BACT guidance for bioenergy emissions (“Bioenergy BACT 

Guidance”) concurrently with its proposal to defer regulation of biogenic CO2 emissions 

under the Clean Air Act’s prevention of significant deterioration (“PSD”) and Title V 

permitting programs.1 As explained below, the Bioenergy BACT Guidance fails to 

provide necessary technical support for case-by-case BACT determinations. Instead, in a 

dramatic departure from past EPA practice, the Bioenergy BACT Guidance explicitly 

encourages permitting authorities to substitute broad policy judgments for the case-bycase analysis required by statute and regulations. Indeed, the real purpose of the 

Bioenergy BACT Guidance appears to be to provide an effective exemption from BACT 

analysis for all bioenergy facilities that might not be covered by the deferral rule’s 

absolute exemption from PSD permitting. EPA’s approach in the Bioenergy BACT 

                                                           

1

 Deferral for CO2 Emissions From Bioenergy and Other Biogenic Sources Under the 

Prevention of Significant Deterioration (PSD) and Title V Programs: Proposed Rule, 76 

Fed. Reg. 15,249 (March 21, 2011); U.S. EPA, Guidance for Determining Best Available 

Control Technology for Reducing Carbon Dioxide Emissions from Bioenergy Production

(Mar. 2011) (hereafter “Bioenergy BACT Guidance”). We reemphasize EPA’s 

Disclaimer in the Bioenergy BACT Guidance that “[t]his document is not a rule or 

regulation” and “does not change or substitute for any law, regulation, or any other 

legally binding requirement and is not legally enforceable.” Bioenergy BACT Guidance 

(“Disclaimer”). Therefore, despite the comments below demonstrating the patent 

unlawfulness of much of this guidance, we do not concede, and EPA correctly 

recognizes, that this guidance has no binding effect on permitting authorities and cannot 

override the express requirements of the Clean Air Act and validly promulgated and 

lawful EPA regulations. 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 2 

Guidance—like the deferral rule overall—is arbitrary, unsupportable, and all but certain 

to encourage legally and factually deficient BACT determinations. 

1. EPA Has Not Demonstrated that Biomass Combustion Per se Constitutes BACT 

Once EPA has determined that a facility is a “major emitting facility,” the next 

relevant inquiry is whether the source has complied with mandatory PSD requirements, 

including the BACT requirement. While the applicability determination is 

straightforward, the question of when biomass may – if ever – qualify as BACT is less so. 

a. EPA Has Not Shown that Biomass Is a “Clean Fuel” 

EPA has not directly proposed that biomass be considered a “clean fuel” based on an 

accounting of the CO2 emissions associated with the full lifecycle, production and use of 

the feedstock. We have previously noted that the legal basis for incorporating this type of 

lifecycle analysis into the BACT determination is unclear.2

 However, should EPA 

determine that it has such authority, any determination that biomass constitutes a “clean 

fuel” must be made in accordance with the Clean Air Act and EPA regulatory precedent. 

That is, it must be made in accordance with the top-down, five step process in the 1990 

New Source Review Workshop Manual3 and must be made on a case-by-case basis. 

The statute defines BACT as “an emission limitation based on the maximum 

degree of reduction of each pollutant subject to regulation under this chapter emitted 

from or which from any major emitting facility, which the permitting authority on a caseby-case basis, . . . determines is achievable for such facility though the application of 

production processes and available methods, systems, and techniques, including fuel 

cleaning, [and] clean fuels.”4

 Although there has been little guidance as to what 

constitutes a clean fuel, historically the focus on whether a given fuel type constitutes a 

“clean fuel” has focused on a facility’s at the stack emissions – that is, whether the fuel is 

                                                           

2 See Comments of Clean Air Task Force, et al., and Comments of Center for Biological 

Diversity, in response to EPA’s Call for Information (EPA Docket ID Nos. EPA-HQOAR-2010-0560-0432 and EPA-HQ-OAR-2010-0560-0157); see also Center for 

Biological Diversity, Re: PSD and Title V Permitting Guidance For Greenhouse Gases, 

75 Fed. Reg. 70,254 (Nov. 17, 2010) (EPA Docket ID No. EPA-HQ-OAR-2010-0841-

0058). 

3

 New Source Review Workshop Manual; Prevention of Significant Deterioration and 

Nonattainment Area Permitting (Oct. 1990) (“1990 NSR Manual”). 

4

 42 U.S.C. § 7545(3). 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 3 

“inherently cleaner” in terms of at the stack emission than an alternative.5 If a fuel could 

only be considered “clean” in these terms, however, biomass could never qualify as 

BACT because, per unit of energy, biomass combustion emits more CO2 than coal and 

significantly more than natural gas. Therefore, any determination that biomass is 

“cleaner” than fossil fuels must necessarily be based on an accounting of the CO2

emissions associated with the full lifecycle of the feedstock. 

As EPA recognizes, with fossil fuel combustion, there is effectively no way to 

restore the carbon stocks lost by combusting those fuels in any near term timeframe.6

 

EPA claims that biomass is different because the potential growth of additional biomass 

arguably results in resequestration of carbon dioxide; however, biomass combustion also 

incurs a “carbon debt” that can persist for decades or even centuries depending on the 

time needed for resequestration. EPA itself has properly acknowledged that different 

types of biomass have different types of lifecycle emissions. For example, current 

studies have shown that burning whole green trees causes more near term climate change 

damage than burning coal or natural gas.7 For these reasons, if EPA were to propose that 

any particular biomass feedstock be treated as a clean fuel, it would have to do so based 

on appropriate lifecycle analyses.8

 

Any such determination, however, must be made in accordance with the CAA. 

Namely, the analysis must be made on a case-by-case basis and in accordance with the 

top-down, five-step BACT analysis, which is consistent with the Clean Air Act’s 

requirements for BACT. 

                                                           

5

 Comments of Clean Air Task Force on PSD and Title V Greenhouse Gas Tailoring Rule 

at 17-18 (EPA Docket ID No. EPA-HQ-OAR-2009-0517-6200.1). 

6

 76 Fed. Reg. at 15,254. 

7 See Manomet Study at 7. 

8

 We do not concede that, in general, a lifecycle analysis is appropriate for determining 

that combustion of a particular fuel by itself constitutes BACT. For instance, we do not 

concede, as was suggested in EPA’s BACT GHG guidance white paper, that methane 

emissions from coal or natural gas extraction should be considered in the BACT process. 

U.S. EPA, Available and Emerging Technologies for Reducing Greenhouse Gas 

Emissions from Coal-fired Electric Generating Units, 20 (Oct. 2010). Moreover, BACT 

has generally been read as requiring that the “emission limitation” established through the 

analysis be immediately applicable upon receipt of the permit and commencement of 

operation. Any consideration of potential future resequestration in determining a BACT 

emissions limitation therefore contradicts long-term EPA precedent. 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 4 

First and foremost, the CAA requires that each BACT determination must be 

made “on a case-by-case basis” wherein the permitting authority may take into account 

“energy, environmental, and economic impacts and other costs[.]”9

 We are aware of no 

authority that allows a permitting authority to deviate from this requirement. While EPA 

objects that such a case-by-case analysis would be “complex” and “time consuming” with 

respect to biomass, EPA has not offered any facts or evidence demonstrating that this will 

be the case in every instance. Nor has the agency adequately explained why this 

“complexity” justifies a de facto exemption from the case-by-case BACT analysis 

requirement.10 This contravenes the plain language of the statute. There are more legally 

defensible ways for EPA to assist permitting authorities in this process, such as by 

identifying carbon lifecycle accounting methods from the scientific literature that may be 

appropriate for assessing the impacts of using a particular feedstock. In any event, the 

permitting authority must still engage in a case-by-case accounting at the facility level of 

emissions associated with the full chain of fuel production and use.11

Second, as EPA recognizes, permitting authorities should continue to apply the 

five-step, top down analysis when permitting new or modified sources of GHGs.12 Even 

though EPA’s assertion is correct on its face, its application of the top-down BACT 

analysis in the Bioenergy BACT Guidance is misguided. EPA there asserts that “[s]tep 4 

of the BACT analysis seems well-suited to enable permitting authorities to consider the 

potential sequestration of carbon in biogenic resources outside the boundaries of the 

facility when evaluating BACT for greenhouse gases.”13 However, as is explained here 

and in comments by Clean Air Task Force on the November 2010 BACT GHG 

Guidance,14 this presupposes without explanation that biomass should be listed as a 

control technology at Step 1 in the first instance. 

                                                           

9

 42 U.S.C. § 7479(3). 

10 See Bioenergy BACT Guidance at 23. 

11 76 Fed. Reg. at 15,529. For instance, as noted above, a permitting authority would 

have to take into account whether use of these feedstocks would result in increased, 

indirect emissions. This could occur, for instance, if feedstocks that were originally 

being used for consumer goods, such as furniture, are proposed to be diverted for 

bioenergy purposes. 

12 Bioenergy BACT Guidance at 11. 

13 Id. at 21. 

14 Comments of Clean Air Task Force et al. on PSD and Title V Permitting Guidance for 

Greenhouse Gases at 3 (EPA Docket ID No. EPA-HQ-OAR-2010-0841-0085). This 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 5 

EPA’s own guidance, which has been in effect and applied by permitting 

authorities for decades, demonstrates that the available BACT options, including clean 

fuels, must be determined at step 1 to even proceed to the subsequent steps of the BACT 

analysis: “The first step in a ‘top-down’ analysis is to indentify, for the emission unit in 

question . . ., all ‘available’ control options.”15 Only once something has been identified 

as a valid “control technology” may it be discounted at further steps in the analysis 

(including based on environmental considerations at step 4). Therefore, EPA’s 

November 2011 BACT GHG Guidance and the Bioenergy BACT Guidance simply put 

the cart before the horse by presupposing, without any explanation, that biomass should 

be listed as even a threshold matter. This is particularly true with respect to biomass 

combustions because it will inevitably result in more CO2 emissions per unit of energy 

than other types of fuel. Therefore, if permitting authorities are to conclude that biomass 

constitutes an available control technology based on a lifecycle analysis, this must occur 

at step 1 and not at step 4.16

                                                                                                                                                                                

guidance was updated in March 2011 by EPA. This guidance was originally issued in 

November 2010 and was updated by EPA in March 2011, see U.S. EPA, PSD and Title V 

Permitting Guidance for Greenhouse Gases (Mar. 2011). References to the original 

guidance issued in November are referred to as the “November 2010 BACT GHG 

Guidance.” References to the updated BACT GHG Guidance are “BACT GHG 

Guidance (updated March 2011).” 

15 1990 NSR Manual at B.5. 

16 Clean Air Task Force and other environmental organizations commented on the 

relationship between Step 3 and Step 4 of the BACT analysis as discussed in the 

November 2010 BACT GHG Guidance. In that guidance, EPA suggested that a less 

effective control technology could be chosen on the basis of environmental 

considerations despite the availability of more stringent control technologies. (EPA has 

since updated this guidance in March of this year). Clean Air Task Force and others 

noted that historically, as EPA continues to recognize, “[t]he top-ranked options should 

be established as BACT unless the permit applicant demonstrates to the satisfaction of 

the permitting authority that technical considerations, or energy, environmental, or 

economic impacts justify a conclusion that the top-ranked technology is not ‘achievable’ 

in that case. If the most effective control strategy is eliminated in this fashion, then the 

next most effective alternative should be evaluated, and so on, until an option is selected 

as BACT.” BACT GHG Guidance (updated March 2011) at 19; see also 1990 NSR 

Manual at B.26-29. Despite this well established precedent, EPA seems to suggest that a 

permitting authority may choose a lesser effective control technology based solely on 

step 4 environmental, energy, or economic considerations even though other more 

stringent technologies have not been eliminated. BACT GHG Guidance (updated March 

2011) at 41. These two approaches cannot be reconciled and as was stated in comments 

on the November 2010 BACT GHG Guidance, EPA has not provided any authority to 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 6 

In sum, if EPA determines that it has authority to determine that biomass constitutes a 

clean fuel based on a full lifecycle emissions analysis, then such an analysis must be 

conducted in accordance with the requirements of the CAA. First and foremost, the 

analysis must be done on a case-by-case basis. While EPA may prefer to determine that 

certain types of biomass probably constitute BACT, it must nonetheless conduct an 

analysis at the facility level to demonstrate that this is indeed the case. 

Finally, we continue to object to EPA’s conclusion that a lifecycle analysis may be 

conducted at step 4 of the top-down analysis. This is contrary to decades-long EPA 

precedent, which requires that a fuel must be listed as a control technology – because of 

its effectiveness in reducing emissions – at step 1 of the analysis 

2. EPA’s Proposed Expansion of the Step 4 Analysis Is Unprecedented and 

Unlawful 

The BACT Bioenergy Guidance does not actually propose that careful, case-by-case 

lifecycle analysis be conducted at step 4 of the BACT process. Rather, EPA proposes 

that the step 4 inquiry be used to avoid the necessity for analysis in the first place. In 

essence, EPA counsels permitting authorities to conduct a rigged analysis that substitutes 

preconceived policy judgments for pollution control technologies and ignores the 

environmental, economic, and energy drawbacks of widespread biomass energy 

generation. The real purpose of EPA’s proposal—to create a de facto exemption from 

real BACT analysis for bioenergy facilities that cannot avail themselves of the broader 

exemption in the proposed deferral rule—is as unlawful as it is obvious. 

The flaws in EPA’s approach pervade each area of Step 4 analysis: environmental, 

economic, and energy impacts. 

a. Environmental Impacts 

EPA’s guidance for assessment of environmental impacts is deeply problematic. 

First, EPA deviates from past practice by proposing that the analysis consider the effects 

of CO2 emissions, namely the fact that “the production of biomass entails carbon 

                                                                                                                                                                                

demonstrate that step 4 considerations may be the sole basis for determining the BACT 

emissions limitation. Comments of Clean Air Task Force et al. on “PSD and Title V 

Permitting Guidance for Greenhouse Gases” at 6 (EPA Docket ID No. EPA-HQ-OAR2010-0841-0085). The Bioenergy BACT Guidance would appear to apply this faulty 

reasoning, and to the extent it does, the guidance continues to be without legal support 

and contrary to the statutory and regulatory requirements of the BACT analysis. See 

Bioenergy BACT Guidance at 16-18. In other words, if there is a control technology 

with demonstrably lower emissions than biomass that has not been eliminated due to a 

step 4 consideration, it is that technology that must be chosen as BACT. 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 7 

sequestration.”17 This is true as far as it goes, but it proves only that biomass contains 

carbon. EPA, however, apparently takes this statement to mean that the combustion of 

biomass entails carbon sequestration, which is an entirely different proposition, and not 

necessarily a true one. Burning biomass does not by itself guarantee future land-based 

sequestration. 

EPA also proposes that permitting authorities measure bioenergy emissions against a 

land-based “business as usual” sequestration baseline. EPA’s baseline concept, however, 

is underdeveloped.18 Even if a future land-based “baseline” were developed for use in 

case-by-case BACT determinations, it would need to be far more robust and inclusive 

than the approach contemplated in either the proposal or the Bioenergy BACT Guidance. 

Such an approach must consider the effects of policy actions and incentives (including 

deregulatory actions like the proposal) on forest and land management. It also must 

accurately account for the short-term climate impacts associated with immediate 

combustion of materials that would otherwise decompose over time; even “waste” 

biomass materials like forest residues can take decades to decompose, and combustion of 

these materials will transform stored carbon into climate-forcing CO2 far more rapidly 

and efficiently.19 Such an approach also must account for the lost capacity for additional 

sequestration associated with biomass removal and combustion. Over time, a growing 

forest may sequester far more carbon if left alone than if harvested and burned for energy, 

even if the carbon lost to combustion is eventually replaced with new growth.20 EPA’s 

skeletal “baseline” proposal does not seem to consider lost sequestration capacity at all. 

 EPA further repeats the proposal’s unsupported conclusions that certain biomass 

feedstocks (such as mill waste and dead trees) have “negligible” climate impacts. As 

previously discussed, these assertions lack adequate explanation or scientific support and, 

as such, cannot be used to justify a determination that burning these feedstocks 

constitutes BACT. 

                                                           

17 Bioenergy BACT Guidance at 20. 

18 See Bioenergy BACT Guidance at 22. 

19 See Anna Repo, Indirect Carbon Dioxide Emissions from Producing Bioenergy from 

Forest Residues, GLOBAL CHANGE BIOLOGY BIOENERGY (2010) (doi: 10.1111/j.1757-

1707.2010.01065.x ). 

20 See Eric Johnson, Goodbye to Carbon Neutral: Getting Biomass Footprints Right, 29 

ENVTL. IMPACT ASSESSMENT R. 165 (2008). 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 8 

Finally, EPA’s guidance completely ignores the wider environmental impacts of 

widespread bioenergy generation. As discussed elsewhere in this letter, implementation 

of policies favoring bioenergy—including favorable regulatory policies such as 

contemplated in the proposal and the Bioenergy BACT Guidance—will result in 

increased demand for woody biomass fuel. EPA even admits as much in extolling the 

economic benefits of bioenergy generation. But this increased demand will necessarily 

affect forest and land management, degrade forest habitat, result in more aggressive 

logging operations that degrade water quality, and cause impacts to human health 

resulting from conventional pollutant emissions from a new fleet of biomass facilities. In 

effect, EPA advises permitting authorities to consider only the purported benefits of 

biomass energy generation—benefits that EPA has not shown to exist—and none of the 

drawbacks. A BACT analysis should include an honest assessment of the environmental 

consequences of any particular control technology. The Bioenergy BACT Guidance, in 

contrast, rigs the game, sending permitting authorities on an outcome-oriented path 

toward a preordained conclusion. 

b. Economic Impacts 

Once again, EPA deviates from past practice in recommending that permitting 

authorities consider the “indirect” economic impacts—or, more accurately, the “potential 

economic benefits”—of bioenergy generation.21 EPA does not even attempt to explain 

why such analysis is appropriate in the context of bioenergy facilities, when it has not 

been appropriate for any other type of facility. 

Going one step further, EPA openly recommends that permitting authorities substitute 

policy preferences for actual analysis of economic impacts. EPA asserts that the 

“underlying objectives” of policies promoting bioenergy “may be considered as a 

relevant indirect economic impact or benefit” under step 4—regardless of whether such 

an impact or benefit actually occurs. EPA likewise states that where selection of a 

“particular option” (i.e., biomass combustion) as BACT would “further the goals” of such 

a policy, this may form “part of the basis” of selecting that option as BACT. These 

objectives, goals, and policy judgments, however, have nothing to do with whether the 

choice of any particular facility to burn biomass will have any particular economic 

impact. This aspect of step 4 analysis should be concerned with establishing the costeffectiveness of pollution control measures, not with advancing unrelated “goals” and 

“objectives.” These policy judgments have no place in BACT analysis. 

                                                           

21 Bioenergy BACT Guidance at 25. 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 9 

c. Energy Impacts 

EPA again advises permitting authorities to “broaden the scope” of energy impacts 

analysis beyond what has traditionally occurred at step 4. Once again, the rationale for 

this broadening is that “a variety of state and federal policies” favor bioenergy.22 EPA 

thus again recommends that permitting agencies substitute policy judgments for analysis 

under step 4. 

Even if such an expansion of scope were permissible, EPA’s policy-driven guidance 

would skew the resulting analysis. For example, EPA recommends consideration of 

policies that require replacement of fossil fuels with “renewable” fuels. Yet EPA fails to 

acknowledge that many of these policies establish a renewable “portfolio” target that 

could be satisfied by any number of renewable generation technologies, including far less 

carbon-intensive technologies like solar and wind. Under these policies, biomass 

generation does not necessarily replace fossil fuel generation, but rather competes with 

other forms of renewable generation. In effect, making a policy judgment in favor of a 

carbon-intensive, low-efficiency, and highly polluting biomass facility could have the 

effect of foreclosing a far cleaner and less carbon-intensive alternative. By focusing 

solely on the purported benefits of biomass energy generation, and by resolutely ingoring 

any possible drawbacks, EPA precludes any real analysis of indirect energy impacts. 

3. The “Bioenergy BACT Guidance” Effectively Constitutes Presumptive BACT 

The Bioenergy BACT Guidance, in effect, advises permitting authorities to presume 

that biomass combustion is BACT for itself. EPA accomplishes this by stating that 

where a bioenergy facility is projected to provide energy and economic benefits in 

accordance with state and federal policies promoting bioenergy generation, these 

considerations may justify selecting a biomass fuel as BACT for CO2 emissions from the 

facility.23 Put more succinctly, if a bioenergy facility advances policies promoting 

bioenergy, the BACT analysis for CO2 is presumed to be satisfied. 

Of course, what EPA proposes is nothing more than a tautology. Bioenergy facilities 

will almost always advance policies favoring bioenergy facilities. Yet this conclusion 

tells permitting authorities absolutely nothing about the environmental, economic, or 

energy impacts of a particular biomass fuel or facility. This conclusion, in other words, is 

a mere presumptive judgment that cannot substitute for BACT analysis. Any such 

presumption, moreover, is patently unlawful. First, the requirement that BACT be 

                                                           

22 Bioenergy BACT Guidance at 27. 

23 Bioenergy BACT Guidance at 29. 
Comments Re: U.S. EPA Biogenic CO2 BACT Guidance Page 10 

conducted on a “case-by-case” basis is a statutory requirement.24 EPA has not met the 

especially high burden associated with justifying a deviation from this requirement. It 

states merely that “such a case-by-case analysis of the net atmospheric impact of biomass 

fuels would likely be prohibitively time-consuming and expensive” and “would require 

extensive analysis” and “extensive workload requirements.” 25 EPA, however, provides 

no support for this conclusion.26 Therefore, EPA has failed to meet the “especially high 

burden” of deviating from the plain language of the Clean Air Act by justifying its action 

unsubstantiated future predictions of regulatory difficulty.27

                                                           

24 42 U.S.C. § 7479(3); see also 1990 NSR Workshop Manual at B.1 & B.5. 

25 Bioenergy BACT Guidance at 23. 

26 Compare 75 Fed. Reg. at 31,556-57 (noting that failure to tailor the PSD thresholds 

would “increase the size of the PSD program at least an order of magnitude beyond what 

Congress seems to have expected” and noting the total additional workload and cost to 

permitting authorities absent tailoring). 

27 Alabama Power Co. v. Costle, 636 F.2d 323, 359-60 (D.C. Cir. 1980).