Summary of Public Comments and Responses for:
National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial, and Institutional Boilers:
Reconsideration of final rule

                                                                  December 2012

Response to Public Comments on the Proposed Rule and Reconsideration of the final rule for National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial, and Institutional Boilers

                     U. S. Environmental Protection Agency
                 Office of Air Quality Planning and Standards
                                   FOREWORD
This document provides the EPA's responses to public comments on the EPA's National Emission Standards for Hazardous Air Pollutants for Area Source Industrial/Commercial/Institutional Boilers. The EPA published a Notice of Proposed Reconsideration of final rule in the Federal Register on December 23, 2011 at 76 FR 80532. The EPA received comments on this proposed reconsideration via mail, e-mail, and facsimile.  Copies of all comments submitted are available at the EPA Docket Center Public Reading Room.  Comments letters are also available electronically through http://www.regulations.gov by searching Docket ID EPA-HQ-OAR-2006-0790.
This document contains the comments provided by each commenter extracted from the original letter.  For each comment, the name and affiliation of the commenter, the document control number (DCN) assigned to the comment letter, and the number of the comment excerpt is provided. In some instances the comment excerpts may not be verbatim in that we have endeavored to be consistent within this document with regard to terminology (e.g., rule names, technical terms and their acronyms). The text of the comment excerpt should not be seen as indicating the EPA's agreement with the factual accuracy of the comment, policy opinions expressed by the commenter, or the legal conclusions or analysis of the comment except where the agency explicitly notes it is adopting some or all of the comment as part of its rationale.  A response thanking a commenter for support for EPA's position does not indicate we are adopting its rationale as a basis for the rule. The EPA requested comment on specific reconsideration issues and accepted public comment only on those issues. All comments on topics other than those being considered are shown as out-of-scope.
Many of the EPA's responses to comments are provided immediately following each comment excerpt. However, in instances where multiple commenters raised similar or related issues, the EPA provided a single response addressing the topic. The response to all other comment excerpts on the topic references the response that addresses the topic. Out-of-scope comments were given a response reminding commenters that only the reconsideration issues are being addressed in this document.
Parallel with this rulemaking effort are three separate, but related rulemakings that may be of interest to the stakeholders. These three rules are: National Emission Standards for Hazardous Air Pollutants for Major Source Industrial/Commercial/Institutional Boilers and Process Heaters (Docket ID: EPA-HQ-OAR-2002-0058); Identification of Non-Hazardous Secondary Materials That Are Solid Waste (Docket ID: EPA-HQ-RCRA-2008-0329); and Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Commercial and Industrial Solid Waste Incineration Units (Docket ID: EPA-HQ-OAR-2003-0119). Given the related nature of these rules, many commenters submitted comments to this rulemaking docket that were specific to one of these related rulemakings. Some commenters submitted a single DCN with comments on all four rules while others submitted a separate DCN specific to each rule. Many commenters submitted identical comments to all of these dockets. In order to reduce duplicative comments, this document flags comments associated with any of the above three related rulemakings and out-of-scope comments for this response to comment document and grouped them into specific out-of-scope headings at the beginning. To the extent that the commenter submitted these comments to the appropriate rulemaking document, responses have been developed in the response to comment documents for each of these related rulemakings. For this reason, the EPA encourages the public to read the other response to comment documents prepared for these three other rulemakings as they may contain topics relevant to these other rulemakings.

The contact regarding questions or comments on this document is:

		Mary Johnson
         U.S. Environmental Protection Agency
         	Sector Policies and Programs Division
         	Office of Air Quality Planning and Standards
         	Research Triangle Park, North Carolina, 27711
<PHONE_NUMBER>
<EMAIL_ADDRESS>.

                               TABLE OF CONTENTS
Section	Page
Out of Scope: NHSM Rule	1
Out of Scope: CISWI Rule	13
Out of Scope: Major Source Boiler Rule	17
Legal/Applicability Issues: Exemption for temporary boilers	58
Legal/Applicability Rationale: Standards for biomass-fired boilers	68
Legal/Applicability Rationale: Standards for oil-fired boilers	77
    Legal/Applicability Issues: Miscellaneous	79
Legal/Applicability Issues: Out of Scope	80
MACT Floor Analysis Rationale: Use of UPL for setting CO emission limits	104
MACT Floor Analysis: Out of Scope	112
Beyond-the-Floor Energy Assessment: Scope	128
Beyond-the-Floor Energy Assessment: Compliance date	144
Beyond-the-Floor Energy Assessment: Maximum duration requirements	145
Beyond-the-Floor Energy Assessment: Out of Scope	151
Rationale for Subcategories: Subcategory for Seasonally Operated Boilers	162
Rationale for Subcategories: Out of Scope	174
Work Practices/Management Practices: Initial tune-ups at new sources	179
Work Practices/Management Practices: Tune-up schedule for seasonal boilers	181
Work Practices/Management Practices: General	184
Work Practices/Management Practices: Out of Scope	188
Other Comments on Data: Out of Scope	197
Rule Language Corrections: Definition of Natural gas curtailment	198
Rule Language Corrections: Definition of Process heater	210
Rule Language Corrections: Definition of Residential boiler	214
Rule Language Corrections: Other Definitions	218
Rule Language Corrections: Tables 1 through 7	250
Rule Language Corrections: Rule language	256
Rule Language Corrections: Out of Scope	268
Testing/Monitoring: Rationale for 30-day rolling average for parameter monitoring	271
Testing/Monitoring: CO CEMS-Appropriate compliance alternative	281
Testing/Monitoring: CO CEMS-Specifications/operations	283
Testing/Monitoring: Oxygen Monitors-Appropriateness and location	285
Testing/Monitoring: Oxygen Monitors-Specifications/Operations	290
Testing/Monitoring: Out of Scope	292
SSM: Affirmative defense provisions for malfunctions	299
SSM: Out of Scope	332
Recordkeeping and Reporting Requirements: Energy Assessment Report	334
Recordkeeping and Reporting Requirements: Out of Scope	338
Compliance: Initial compliance schedule for existing boilers subject to tune-ups	340
Compliance: Tune-up schedule for small oil-fired units	364
Compliance: Out of Scope	371
Impacts Analysis: Proposed Amendments	372
Impacts Analysis: Out of Scope	378
Title V Rationale: Exemption for all area sources	383
GACT Analysis/Rationale: Results of PM standards for new oil-fired boilers	391
Petition Issues Not Granted Reconsideration: Legal/Applicability: De minimis threshold	403

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Out of Scope: NHSM Rule
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Commenter Name: David P. Tenny
Commenter Affiliation: National Alliance of Forest Owners (NAFO)
Document Control Number: EPA-HQ-OAR-2006-0790-2440-A1
Comment Excerpt Number: 1
Comment: Proposed Amendments to the Non-Hazardous Secondary Materials (NHSM) Rule
The NHSM Rule is of critical importance to NAFO's members because it determines whether the co-products associated with biomass production processes are considered fuels subject to the Major Source Boiler Rule or solid waste subject to the more stringent Commercial and Industrial Solid Waste Incinerator (CISWI) Rule when combusted for energy. The combustion of biomass residuals for energy is an important component of the production processes for many of NAFO members' customers. Other customers rely on these materials as valuable co-products which can be sold for energy production by third parties. Yet experience has shown that classifying these materials as "solid waste" ensures that they will not combusted for energy due to the high costs of compliance with CISWI standards. Rather than attempting to meet the more stringent limits, facilities will simply switch to other fuels that are subject to the less stringent Major Source Boiler Rule standards.
The NHSM Rule promulgated by the Environmental Protection Agency (EPA) in March 2011 suffers from a number of flaws that will harm NAFO members and prevent the use of many clean, renewable secondary materials for biomass energy production. First, the definition of clean cellulosic biomass lacked sufficient clarity, creating uncertainty whether certain types of biomass were considered clean cellulosic biomass and could be combusted for energy without triggering CISWI requirements. Second, the rule improperly classified many traditional biomass fuels as solid waste despite their long history of use as valuable fuel products. Third, the limited access to complicated petitioning processes failed to provide adequate redress for regulated entities (and their suppliers) when the default rules classified their biomass fuel supplies as solid waste.
The proposed rule includes a number of revisions that will have a positive impact on NAFO's members and appropriately encourage the use of biomass secondary materials as valid traditional fuels. As described below, NAFO generally supports the EPA's proposed changes, but believes that additional changes are needed to accurately reflect the historic role of biomass secondary materials as traditional fuels.
A. EPA Must Not Exceed Its RCRA Authority by Seeking to Regulate Biomass
Energy Feedstocks That Have Not Been Discarded
The EPA's authority over secondary materials is limited to material that has been discarded. Under the Resource Conservation and Recovery Act (RCRA), only material that has been "discarded" meets the definition of "solid waste." (See Ass'n of Battery Recyclers v. EPA, 208 F.3d 1047, 1051 (D.C. Cir. 2000) ("Congress unambiguously expressed its intent that `solid waste' (and therefore the EPA's regulatory authority) be limited to materials that are `discarded' by virtue of being disposed of, abandoned, or thrown away.").) The D.C. Circuit has also established the transfer of a co-product from a generator to a third part does not create a presumption that the material has been discarded because firms may prefer to transfer biomass co-products to third parties who can use them more efficiently. (See Safe Food and Fertilizer v. EPA, 350 F.3d 1263, 1268 (D.C. Cir. 2003) ("As firms have ample reasons to avoid complete vertical integration, . . . firm to firm transfers are hardly a good indicia of a `discard' as the term is ordinarily understood." (citation omitted)). As such, if a material is a valuable product or industrial input, and handled as such, the EPA cannot regulate it under RCRA.)
As described above, biomass provides a clean, renewable alternative to fossil fuels and represents an important part of the Administration's clean energy policy. In order to support and further that policy, the EPA must adopt regulations that support existing biomass energy facilities and encourage the development of new biomass energy facilities, whether they rely on traditional biomass fuels or, through ingenuity, develop new energy opportunities for biomass co-products. Any presumption that biomass co-products are discarded waste products is inconsistent with this objective and, as described below, we urge the EPA to avoid such presumptions in its regulations. While a policy of encouraging biomass energy would be most consistent with the Administrations goals, the EPA must not take positions that are in conflict with that goal. At a minimum, the EPA must adopt a neutral policy that does not presume biomass materials are discarded solid waste.
Accordingly, we urge the EPA to interpret its RCRA authority narrowly to ensure that the materials it seeks to regulate have actually been discarded. Any material that is treated by generators or their customers as a valuable fuel feedstock and is actually combusted for energy production has not been discarded and thus is outside of the EPA's authority under the NHSM Rule. It is irrelevant whether the material is a traditional or newly developed fuel or whether the fuel is combusted by the generator or by a third party. In any case, biomass materials with value as energy feedstocks are not discarded and should not be subject to the EPA's authority under RCRA or the more stringent CISWI Rule emissions limitations.
B. Definition of "Clean Cellulosic Biomass," 40 CFR §241.2
NAFO believes that all trees and all other materials taken from the forest are "clean" cellulosic biomass and supports the EPA's conclusion that clean cellulosic biomass materials are traditional fuels and thus are not solid waste when burned for energy. NAFO supports the EPA's decision to clarify the definition of clean cellulosic biomass by including more comprehensive examples of secondary materials that qualify as clean cellulosic biomass. However, we believe that additional steps can be taken to provide greater clarity to the rule and greater assurance to regulated entities that additional forest products qualify as clean cellulosic biomass and will not be considered solid waste.
NAFO agrees with the EPA's conclusion that the list of materials included in the clean cellulosic biomass definition should not be considered exhaustive and supports the EPA's addition of the phrase "including, but not limited to" in the definition. (76 FR 80470.) This change will provide regulated entities with the assurance that unlisted materials will not be categorically considered to be solid waste and provide them with the flexibility to alter fuel mixes and incorporate traditional fuels that are not explicitly listed in the definition of clean cellulosic biomass without fear of becoming subject to the more stringent CISWI Rule emissions standards.
In NAFO's comments on the June 4, 2010 Proposed NHSM Rule, we suggested adding clarity to the forest derived biomass portion of cellulosic biomass definition. We appreciate the EPA's explanation on page 173 in its "Responses to Comments Document for the Identification of Non-Hazardous Secondary Materials That Are Solid Waste Rulemaking (February 2011)," posted at EPA-HQ-RCRA-2008-0329 on March 21, 2011: "Under the final rule, forest-derived biomass, including green wood, forest thinnings, clean and unadulterated bark and tree harvestings residuals, is considered an alternative traditional fuel. The categories would encompass dead trees and wood residues." NAFO also supports the EPA's decision to include "hogged fuel, wood pellets, untreated wood pallets[, and] urban wood (e.g. tree trimmings, stumps, and related forest-derived biomass from urban settings)" and "byproducts of ethanol natural fermentation processes" within the definition clean cellulosic biomass. This expanded definition, along with the EPA's response to NAFO's comments, will provide assurance to the entities that produce and combust these traditional biomass energy fuels and appropriately encourages their use clean, renewable fuels. However, we urge the EPA to provide greater clarity by removing from the final rule the caveat that "Clean biomass is biomass that does not contain contaminants at concentrations not normally associated with virgin biomass materials." (76 FR 80529.) Despite the EPA's efforts to provide an expansive definition of clean cellulosic biomass that accurately reflects the wide range of biomass feedstocks that have traditionally been used as fuels  -  and thus have not been discarded  -  this final requirement suggests that these traditional fuels must still satisfy the legitimacy criteria discussed in section II.E in order to avoid being classified as solid waste. It also perpetuates the EPA's erroneous interpretation of its authority under RCRA, which is expressly limited to discarded material and does not encompass traditional fuels. This definition of clean cellulosic biomass will be of little value to regulated entities if they are required to complete the NHSM regulatory process and demonstrate compliance with the legitimacy criteria even if the biomass fuels they combust are explicitly included in the definition of clean cellulosic biomass. Thus in addition to removing this confusing sentence, we urge the EPA in the preamble to the final rule to clarify that the feedstocks explicitly listed in the definition of clean cellulosic biomass are traditional fuels that are not subject to the EPA's RCRA authority over discarded materials, whether combusted by generators or by third parties.
C.  Administrative Petition Process for Non-waste Determinations for Non-Generators, 40 CFR §241.3(c)
Despite the additional clarity provided by the revised definition of clean cellulosic biomass, many biomass materials used as fuels are not listed and must instead be considered on a case-by-case basis. For borderline cases, the administrative petition process  -  which currently presumes that all biomass co-products combusted by entities other than generators are solid waste  -  offers a means to obtain assurance that the EPA will consider the material to be a fuel and not solid waste. NAFO supports the EPA's efforts to streamline and add flexibility to the petition process, but believes that additional steps can be made to make the process consistent with the law and more workable in practice.
The proposed rule clarifies a number of features that streamline and add flexibility to the administrative petition process. NAFO agrees with the EPA that any interested person  -  including forest owners  -  should be able to initiate the petition process. It also agrees that petitions should be allowed for entire classes of combustors rather than requiring a case-by-case analysis. These clarifications will encourage all members in the biomass supply chain to promote their products and co-products as clean, renewable fuels and promote the development of new markets for biomass materials. However, NAFO believes that these benefits could be achieved more efficiently by allowing for nation-wide petitions for classes of combustion units rather than requiring separate petitions for each EPA region. NAFO also believes that the administrative petition process could be further streamlined by not seeking public comment on every individual petition. By filing an administrative petition, a petitioner is not seeking to change the EPA's regulatory program or create new legal rights or obligations. Instead, the administrative petition process provides an opportunity for a petitioner to obtain in advance agency concurrence, based on sound science, with respect to the classification of a particular feedstock under existing regulations. In this respect, the administrative petition process differs from the categorical non-waste determination discussed below, where the EPA makes changes the regulatory status of certain secondary materials that are reflected in the Code of Federal Regulations (CFR). Because the public  -  through this rulemaking process  -  has an opportunity to provide input on the EPA's regulations, there is no need to provide a second opportunity for public comment when those regulations are applied by the EPA in specific contexts through the administrative petition process. While the EPA's proposed changes are beneficial, NAFO believes that additional changes could further streamline and provide greater flexibility to the administrative petition process. First, the EPA should adopt a more flexible approach to evaluating petitions, recognizing  -  as it does in the categorical non-waste determination process  -  that fuels should not be considered solid waste, even if they do not meet each of the legitimacy criteria. Second, the EPA should not distinguish between secondary materials combusted by generators and third parties. The current default rule presuming that secondary materials combusted by third parties are solid waste ignores the fact that third parties have traditionally combusted biomass material for energy and discourages the development of new markets for clean, renewable biomass co-products and is not consistent with Congressional intent in RCRA that the EPA only has authority over material that has been discarded. Instead, the EPA should permit non-generators to make the same self-determination as generators that their secondary material fuels are not solid waste. Under this approach, the administrative process would still play a valuable role in providing assurance to all regulated entities in borderline cases.
D. Categorical Non-Waste Determinations for Specific NHSM, Proposed 40 CFR §241.4
NAFO supports the EPA's adoption of its recommendation to categorically classify resinated wood as non-waste.
As described more fully in our previous comments, resinated wood residuals have been used as a traditional fuel source since the 1950s and we applaud the EPA's recognition of this traditional fuel source. NAFO also urges the EPA to make full use of the proposed categorical non-waste determination process and aggressively consider categorical determinations for other traditional fuels. As explained in our previous comments, there are a number of traditional biomass fuels that may not qualify as clean cellulosic biomass under the strict criteria included in the current NHSM Rule. Nevertheless, these secondary materials have a long history of use as energy feedstocks and should not be classified as solid waste. Among these traditional fuels are construction and demolition (C&D) debris; pulp and paper wastewater residues, which consist largely of biomass (wood fiber); paper recycling residuals; and certain treated woods, such as creosote-treated railroad ties. We concur with the analyses submitted by the American Forest & Paper Association in support of a categorical non-waste determination for pulp and paper wastewater residues (pulp and paper sludge) and for construction debris. NAFO supports the EPA's proposed Categorical Non-Waste Determination Process as a means to exclude these traditional fuel products from the definition of solid waste and to provide regulated entities with the necessary assurances that their combustion will not trigger more stringent CISWI Rule emissions limits. To determine whether a non-hazardous secondary material should be granted a categorical non-waste determination, the EPA must focus primarily on whether the secondary material has been discarded or whether it is treated as a co-product with value as an energy feedstock because, as described above, the EPA's regulatory authority over secondary material is limited to material that is discarded. (See Ass'n of Battery Recyclers, 208 F.3d at 1051.) While consideration of other factors such as the legitimacy criteria may aid the EPA in making that determination, the EPA should make clear in the final rule that secondary material will qualify as non-waste if the petitioner can demonstrate that it has not been discarded, but is used instead as a fuel source by the generator or third parties. To this end, NAFO supports the EPA's proposal to add flexibility to the petition and review process for making categorical determinations. First, NAFO supports the EPA's proposal to apply the categorical determinations to all combustors and not merely to generators of secondary materials. This approach appropriately recognizes the many circumstances in which generators have treated their secondary materials as valuable co-products and developed markets for their combustion for energy by third parties. Second, NAFO supports the EPA's proposal to allow any person to file a categorical determination petition with the EPA. In doing so, the EPA appropriately recognizes that other entities besides the generator and combustor have an interest in properly categorizing traditional fuels as non-waste and in developing new opportunities to utilize biomass secondary materials as raw materials in other industrial processes. Third, NAFO supports the EPA's decision to balance the legitimacy criteria with other factors. Many traditional fuels have a long history of use for energy combustion, but may not meet each of the legitimacy criteria. By balancing the legitimacy criteria with other factors, the EPA can take a more flexible approach that can emphasize historic uses of biomass secondary material and respond to new markets as they develop.
E. Legitimacy Criteria, 40 CFR §241.3(d)
NAFO also supports the EPA's proposals to incorporate additional flexibility to the legitimacy criteria applied to NHSM. As explained in our earlier comments, the legitimacy criteria are unnecessarily stringent and will inappropriately exclude some NHSM that are validly reused as energy feedstocks.
First, NAFO agrees with the EPA's proposal to provide regulated entities with the flexibility to apply the legitimacy criteria to individual contaminants or entire classes of contaminants as appropriate. This change will provide greater flexibility to accurately compare the environmental and health impacts of NHSM and traditional fuels. Second, NAFO supports the EPA's proposal to permit comparisons to any traditional fuel that could be combusted in the unit. Again, this added flexibility offers a better opportunity to compare the environmental and public health impacts of NHSM and the traditional fuel alternatives that could be combusted in their place.
While the proposed rule makes a several improvements, the legitimacy criteria remain unnecessarily stringent. However, NAFO continues to disagree with the EPA's decision to place more stringent requirements on legitimacy criteria for NHSM than it does for hazardous materials. First, the EPA should recognize that some traditional fuels do not meet each of the legitimacy criteria and permit balancing of the legitimacy criteria  -  as it proposes to do under the Categorical Non-Waste Determination Process  -  instead of requiring strict compliance with each criterion. Second, rather than limiting NHSM to those with "contaminants at levels comparable to or lower than those in traditional fuels" (40 CFR §241.3(d)(1)(iii)), the EPA should adopt the standard traditionally applied to hazardous materials where contaminants cannot be present "at levels that are significantly elevated from those found in analogous products." (40 CFR §260.43(c)(2)(ii).) There is simply no justification for applying more stringent standards for secondary materials that are non-hazardous than for those that are hazardous.
Response: This comment pertains to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking docket (EPA - HQ - RCRA 2008 - 0329), the response to this comment will be provided there.
Commenter Name: Samuel Denisco
Commenter Affiliation: Pennsylvania Chamber of Business and Industry
Document Control Number: EPA-HQ-OAR-2006-0790-2478-A2
Comment Excerpt Number: 2
Comment: The Pennsylvania Chamber supports a holistic approach to the fuel versus waste determination that considers historical purposes and uses of the combustion material, rather than narrow application of one or a few legitimacy criteria.
In the proposed revised definition of solid waste materials, the EPA has proposed listing certain (biomass) materials that will be simply designated as non-waste in the definition, regardless of their status under the legitimacy criteria. In addition, the EPA proposed more flexibility in the application of the legitimacy criteria, insofar as the EPA applies the criteria, after the rules are finalized, when making a categorical determination for a particular fuel that would apply to all sources burning that fuel. The Pennsylvania Chamber supports this proposed approach to the fuel vs. waste determination, which will reduce the instances where the rule that applies to an individual boiler hinges on a specific consideration under the legitimacy criteria, (e.g., whether the material is generated on or off site). The Pennsylvania Chamber urges the EPA to clarify in the final rules that this holistic approach will also be applied when making unit-specific fuel versus waste determinations. Such an approach will more accurately distinguish between those materials which have been discarded and are truly being burned as waste from materials which have the characteristics of a legitimate fuel, but may not satisfy all of the legitimacy criteria, which of necessity are designed to cover a broad range of circumstances.
Response: This comment pertains to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking docket (EPA - HQ - RCRA 2008 - 0329), the response to this comment will be provided there.
Commenter Name: James Pew
Commenter Affiliation: Earthjustice, Clean Air Council, Partnership for Policy Integrity
Document Control Number: EPA-HQ-OAR-2006-0790-2480; 2480-A2
Comment Excerpt Number: 12
Comment: Comments on use of NHSM as Fuel
EPA bases its rules on incorrect assumptions about contamination levels in waste wood
The EPA paints a rosy picture of how it is possible to render a "clean" fuel stream from C&D. The EPA's March 2011 document "Identification of non-hazardous secondary materials that are solid waste" states that when C&D is sorted, painted wood is removed. This is not the case. Painted and contaminated wood is routinely burned.
For instance, the picture below is from the Palmer Renewable Energy (MA) facility's application to the Massachusetts Department of Environmental Protection (MassDEP).[1] The facility actively lobbied against any requirement to sort material to remove painted wood, stating "a specific sorting step for painted wood would result in losses of wood with no lead, losing the opportunity for safe beneficial use of this material".[2] When we interviewed the plant manager at New England Recycling, the main facility where Palmer would get its wood, he informed us that the "positive pick" process did not remove painted wood from the line. The majority of the wood they sort there is sent to Maine for burning. The picture below clearly shows painted wood in the debris pile from a Maine facility.
The wood in the picture above is described as "clean." The description of the picture is as follows: "The second facility is Commercial Paving & Recycling Company (CPRC), which operates "wood recycling" operations at the City of Portland Riverside Facility and at CPRC's Scarborough Facility. At these sites, C&D wood is primarily received in a pre-sorted condition. CPRC only accepts pre-sorted, "clean" C&D wood and prohibits plastics, treated woods, noncombustibles, fines (dirt, wallboard, sawdust, roofing materials), asbestos, and metals from the wood storage piles (see Figure 2-7)."
[1] Palmer Renewable Energy Project: Major comprehensive air plan approval application, revised June 29, 2009. Submitted to MassDEP, Springfield, MA.
[2] Palmer Renewable Energy Project. Beneficial use determination application. Revised June, 2009. Submitted to MassDEP, Springfield, MA.
Response: This comment pertains to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking docket (EPA - HQ - RCRA 2008 - 0329), the response to this comment will be provided there.
Commenter Name: James Pew
Commenter Affiliation: Earthjustice, Clean Air Council, Partnership for Policy Integrity
Document Control Number: EPA-HQ-OAR-2006-0790-2480; 2480-A2
Comment Excerpt Number: 13
Comment: The "Evergreen Community Power" facility in Reading, PA is a synthetic minor source for Best Available Control Technology (BACT) (we could not ascertain its status with regard to hazardous air pollutant (HAP) emissions). A Department of Energy (U.S. DOE) report on the facility[3] states that its fuel consists of "forest industry waste, shredded construction wood waste, and demolition debris. The `mulch' is mostly wood product, but there are significant amounts of paper, plastic and foreign debris." The typical fuel composition is shown below.[3] (Department of Energy, Mid-Atlantic Clean Energy Application Center, Evergreen Community Power Plant Case Study, November 16, 2011.)
Comparison with traditional fuels for C&D should be restricted to virgin biomass. The EPA states that in determining whether a NHSM meets the legitimacy criteria, its contamination level must be compared to that of a traditional fuel. The EPA explicitly states that a facility can compare the contamination level of C&D debris and other wood waste to contamination levels in coal, even if the facility is not permitted to burn coal.
Page 80471:
      2. Contaminant Legitimacy Criterion for NHSM Used as Fuels. The 2011 NHSM final rule codified three self-implementing legitimacy criteria that NHSM must meet in order to be considered a non-waste fuel when burned in a combustion unit (40 CFR 241.3(d)(1)(i) - (iii)). One of these criteria focused on comparing levels of contaminants contained in the NHSM to levels of those constituents found in traditional fuels. Specifically, the contaminant legitimacy criterion for fuels was finalized as follows: ``The non-hazardous secondary material must contain contaminants at levels comparable in concentration to or lower than those in traditional fuels which the combustion unit is designed to burn. Such comparison is to be based on a direct comparison of the contaminant levels in the non-hazardous secondary material to the traditional fuel itself.'' 40 CFR 241.3(d)(1)(iii). The existing language provides flexibility for persons to make comparisons on a contaminant- by-contaminant basis or on a group of contaminants-by-group of contaminants basis in determining what constituents to Fuel composition at the Evergreen Community Power facility compare. The phrase ``traditional fuels which the combustion unit is designed to burn'' also provides the flexibility to choose among multiple fuel options.
This old language did not catch our attention in the previous version of the rule because it never occurred to us, when talking about C&D, that the "traditional fuel" used for comparison could be anything other than biomass.
     Industry groups have expressed concern that the regulatory language does not clearly reflect the EPA's intent.[9] The EPA agrees that the regulatory language can be revised to better reflect the EPA's intent in implementing the contaminant legitimacy criterion. Therefore, the Agency is proposing to revise this criterion to read, ``The non-hazardous secondary material must contain contaminants or groups of contaminants at levels comparable in concentration to or lower than those in traditional fuel(s) which the combustion unit is designed to burn. In determining which traditional fuel(s) a unit is designed to burn, persons can choose a traditional fuel that can be or is burned in the particular type of boiler, whether or not the combustion unit is permitted to burn that traditional fuel. In comparing contaminants between traditional fuel(s) and a nonhazardous secondary material, persons can use ranges of traditional fuel contaminant levels compiled from national surveys, as well as contaminant level data from the specific traditional fuel being replaced. Such comparisons are to be based on a direct comparison of the contaminant levels in both the non-hazardous secondary material and traditional fuel(s) prior to combustion.'' We are taking comment on how this revised contaminant legitimacy criterion would apply to specific fuels.
This is a disaster for new biomass electric plants that are area sources and also overwhelmingly synthetic minor sources for BACT. Under this rule, they would be permitted to use wood with contamination levels far above clean biomass, particularly since the EPA specifies it is acceptable to use "ranges of traditional fuel contaminant levels" for purposes of comparison (not averages or medians). This opens the door to comparing biomass/C&D contaminant levels with the highest contaminant levels found in coal. In the face of such a collapse of protection at the federal level, states wishing to protect themselves against C&D burning will be forced to enact new regulations, such as Massachusetts is already doing, in response to the Palmer Renewable Energy proposal to burn C&D which was shown to be so fatally flawed.
This should not be permitted. Clean untreated wood is the obvious "traditional" fuel to which C&D should be compared. C&D wood should not contain contaminants at levels higher than found on average in virgin biomass. This is particularly important for pellet manufacture, since pellets are burned not only in commercial and institutional boilers, such as those found in schools, but also in domestic pellet burners.
Response: This comment pertains to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking docket (EPA - HQ - RCRA 2008 - 0329), the response to this comment will be provided there.
Commenter Name: James Pew
Commenter Affiliation: Earthjustice, Clean Air Council, Partnership for Policy Integrity
Document Control Number: EPA-HQ-OAR-2006-0790-2480; 2480-A2
Comment Excerpt Number: 14
Comment: The EPA must require testing of contaminant levels in fuels.
On page 80477, the EPA states the following:
      Two other issues have arisen during implementation of the 2011 NHSM final rule that, while not leading to specific regulatory changes in today's proposal, still merit discussion. The first issue is that contaminant legitimacy criterion determinations do not require testing contaminant levels, in either the NHSM or an appropriate traditional fuel. Persons can use expert or process knowledge to justify decisions to rule out certain constituents.
The EPA must require testing for contamination. C&D as a waste fuel is extremely variable. "Slugs" of contaminated wood move through sorting facilities at various times. Particularly given the large amount of material that is going to be generated as abandoned and foreclosed housing is torn down, the potential for liberating vast amounts of lead and other urban toxics, to say nothing of arsenic and chromium from pressure-treated wood, has never been higher. Facilities burning this contaminated material tend to be located in urban areas that already have high levels of air toxics. The Evergreen facility in Reading PA is a good example  -  it was built (with $39 million in Stimulus funds) in a county (Berks) that is not only out of attainment with the ozone National Ambient Air Quality Standards (NAAQS), but also with the lead NAAQS (hard to do, considering it is an order of magnitude lower than it used to be). The region where the plant was built is also an environmental justice area. The facility is burning whatever comes through its door, with waste imported from all over the region, including New Jersey.
The potential for C&D fuel to emit toxics used to be taken seriously by the EPA; for instance, in 2010 an ethanol company in Minnesota was fined $120,000 for burning wood contaminated with lead-based paint and arsenic preservatives in its biomass gasification unit.[4] With the proposed rule, the EPA is removing any hope of regulating contaminants from the biomass power industry. Fuel won't be tested, and emissions won't be regulated, especially given the number of large biomass facilities that claim to be "area" sources.

Response: This comment pertains to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking docket (EPA - HQ - RCRA 2008 - 0329), the response to this comment will be provided there.
Commenter Name: James Pew
Commenter Affiliation: Earthjustice, Clean Air Council, Partnership for Policy Integrity
Document Control Number: EPA-HQ-OAR-2006-0790-2480; 2480-A2
Comment Excerpt Number: 15
Comment: Definition of "clean" cellulosic biomass has become too expansive.
The EPA is proposing to modify the definition of "clean" cellulosic biomass. Page 80470:
      Clean Cellulosic Biomass - The EPA is proposing to revise the definition of ``clean cellulosic biomass'' to list additional examples of biomass materials that are appropriately included within this definition.... ....
Thus, the EPA is proposing to revise the definition of ``clean cellulosic biomass'' as follows:
      ``Clean cellulosic biomass means those residuals that are akin to traditional cellulosic biomass, including, but not limited to: agricultural and forest-derived biomass (e.g., green wood, forest thinnings, clean and unadulterated bark, sawdust, trim, tree harvesting residuals from logging and sawmill materials, hogged fuel, wood pellets, untreated wood pallets); urban wood (e.g., tree trimmings, stumps, and related forest-derived biomass from urban settings); corn stover and other biomass crops used specifically for the production of cellulosic biofuels (e.g., energy cane, other fast growing grasses, byproducts of ethanol natural fermentation processes); bagasse and other crop residues (e.g., peanut shells, vines, orchard trees, hulls, seeds, spent grains, cotton byproducts, corn and peanut production residues, rice milling and grain elevator operation residues); wood collected from forest fire clearance activities, trees and clean wood found in disaster debris, clean biomass from land clearing operations, and clean construction and demolition wood. These fuels are not secondary materials or solid wastes unless discarded. Clean biomass is biomass that does not contain contaminants at concentrations not normally associated with virgin biomass materials.''
Comments on bolded terms:
1. Hogged fuel. "Hogging" refers to the process of shredding material. Just because material has been shredded, does not make it clean. This description of a process does not belong in this list, which otherwise consists of material fuel sources.
2. Wood pellets. Like hogging, pelletizing can be done to almost any material. Wood pellets can be made from any kind of wood. The definition should specify "wood pellets made from virgin biomass materials."
3. Byproducts of ethanol natural fermentation processes. This is a discarded waste product and does not deserve the appellation "clean." What is the standard of "virgin biomass" to which is being compared?
4. Clean wood found in disaster debris. This again refers indirectly to a process (the process by which standing wood is knocked down in a disaster such as a tornado). This adds nothing to the list that is not already there (i.e, all the "clean" kinds of materials that could be found in disaster debris are already listed).
5. Clean construction and demolition wood. This should not be in here, because operationally, this material is discarded by definition. Further, the majority of this material can in no way be considered "clean."
Response: This comment pertains to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking docket (EPA - HQ - RCRA 2008 - 0329), the response to this comment will be provided there.
Commenter Name: James Pew
Commenter Affiliation: Earthjustice, Clean Air Council, Partnership for Policy Integrity
Document Control Number: EPA-HQ-OAR-2006-0790-2480; 2480-A2
Comment Excerpt Number: 16
Comment: Asbestos should be included as a regulated contaminant.
The EPA states on page 80475:
      Also, we are proposing to exclude from the definition of contaminants those pollutants in the CAA sections 112(b) and 129(a)(4) lists that we do not expect to find in any NHSM.... Fine mineral fibers are excluded because they are releases from the manufacturing and processing (not combustion) of non-combustible rock, glass, or slag into mineral fibers.
Asbestos is commonly found in C&D debris. Asbestos particles in smoke are deadly. Sorting procedures at C&D sorting facilities commonly attempt to remove material that looks like it contains asbestos, but by nature this material can end up in the "fines". The description[5] of the sorting procedure at a C&D sorting facility in Massachusetts demonstrates why asbestos contamination (and contamination by lead, mercury (Hg), and other toxics) is common:
New England Recycling (NER) accepts mixed C&D waste and separates out ferrous and non-ferrous metals, aggregate (asphalt, brick, concrete (ABC)), old corrugated cardboard (OCC), plastics (Nos. l and 2), gypsum, wood and fines. The mixed C&D is dumped onto the tipping floor where it is inspected for presence of unacceptable materials (hazardous materials, municipal solid waste, and suspect asbestos containing materials). A grapple sorts out large bulky items (large aggregate, bulky insulation or plastics, and large gypsum/wallboard), roughly crushes remaining items and feeds a conveyor to a trommel screen where approximately 1/2 inch fines are removed. The remaining materials move via conveyor onto the sorting line, where some 20 pickers manually remove ABC, OCC, metals, and wood. The wood is thus picked off the line by a positive sort.
Excluding mineral fibers from regulation explicitly ignores the possibility of such contamination in C&D. Asbestos should be a regulated contaminant.

Response: This comment pertains to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the Non-Hazardous Secondary Materials That Are Solid Waste rulemaking docket (EPA - HQ - RCRA 2008 - 0329), the response to this comment will be provided there.
Out of Scope: CISWI Rule
Commenter Name: Carl R. Rutz
Commenter Affiliation: Alyeska Pipeline Service Company
Document Control Number: EPA-HQ-OAR-2006-0790-2447-A2
Comment Excerpt Number: 3
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Comment: 1. Definition of Contained Gaseous Material
At pg 80463 the reconsideration proposal states that the EPA is "not changing its historical interpretation of what gases could be considered to be solid waste (i.e., a 'contained gas')." In that same discussion the EPA states that it has added back into CISWI the definition of "contained gaseous material." When we looked we could not find the definition in the regulatory text. Unless we missed it, it appears that the EPA missed adding the definition back into regulatory text of the reconsideration proposal.
 2. Contained Gas Policy for Regulated Gas Streams Combusted in a Boiler
With respect to the EPA's historical interpretation of contained gas, Alyeska reviewed the RCRA documents that it is aware of that embody that interpretation and the CISWI response to comments. We are still concerned that a narrow reading of the contained gas interpretations and the response to comments may limit its application to fume incinerators (i.e., air pollution control devices). We also are still concerned that the EPA has not assured industry that gas that arises from an air pollution control device, or that is captured through a control device such as a vapor recovery system, that is then routed to and combusted in a boiler will not be considered a non- hazardous secondary material, unless it passes the burden some legitimacy criteria. In the proposed Major Source Boiler Rule on page 80652 there is a definition of "gaseous fuel" that includes process gases, which under that rule a facility should be able to rely upon to describe their combusted gas a fuel. However, in the CISWI Rule there is no such definition or similar discussion. We refer you to the following response to comments for the earlier final CISWI Rule, specifically the bolded text:
Comment [3b-13-4):
Contained Gas--A limited number of commenters indicated that the final rule should contain a definition of "contained gaseous material." The statutory definition of solid waste includes "solid, liquid, semisolid or contained gaseous material." 42 U.S.C. §6903(27) (emphasis added). EPA has interpreted the term "contained gaseous material" to include gases in containers, but not gases flowing through pipes to combustion units. Under  the  June  4,  2010 Response to Comments Document  -NHSM  Rule  Proposed  Revisions  to  the  CISWI  Rule,  the  existing definition of solid waste will be removed, and the rule will rely upon the proposed definition of solid waste here (proposed 40 CFR Part 241).
The commenters state that the preamble language in the proposed rule could be read to suggest that gaseous fuels are to be included in the Part 241 definition of solid waste. In discussing which traditional fuels are to be used for comparison purposes in applying the legitimacy criterion concerning contaminants, the proposed rule says:
      "For example, if the boiler burns fuel oil, the level of contaminants to be compared would be the level of contaminants in fuel oil or other liquid traditional fuels that is or can be burned in such unit, while for gas-fired boilers, the level of contaminants in the non-hazardous secondary material fuels would be compared to natural gas."
The commenter assumes that the EPA does not intend to regulate gaseous fuels through this rule or otherwise under the Clean Air Act (CAA) §129.  Consistent with the statutory definition of solid waste and with the EPA's approach in the 2000 CISWI Rule, the EPA should make clear that "contained gaseous material" is only meant to cover gas in a container when that container and its contents are combusted.
EPA's Response:
As a preliminary matter, EPA wishes to correct certain misconceptions in these comments. First, we wish to make it clear that the statement regarding secondary material fuels replacing natural gas in gas-fired boilers only refers to fuels that are secondary materials. It does not refer to a situation in which a gas-fired boiler can use, for example, refined fuel oil. EPA is aware that fuel oil and gas may be used interchangeably in some boilers. The preamble statement, however, only applies to a secondary material, not a product fuel. Since on specification used oil is considered  an  alternative  "traditional  fuel,"  it  would  not  be  considered  a secondary material.
Next, the EPA also acknowledges that this rule does not apply to vented gas that is in no way contained and simply goes into the atmosphere.
We are not dealing with whether such vented gases are subject to the definition of solid waste. Vented gas simply will not be used as a secondary material in any gas-fired boiler and thus, is not part of this rulemaking; nor is EPA reopening any rules regarding such vented gases. Further, EPA is not considering viewpoints regarding how it regulates gases under the hazardous waste regulations-specifically, whether gases in pipelines are contained.  The Agency needs to   evaluate whether the non-hazardous secondary gaseous material that will be used as substitutes in gas-fired boilers are solid wastes, or not, under the statutory definition. EPA's determination in this rule is based on the plain language of the statute. This leads EPA to the situation covered in this rule. In the first place, we are unable to find any Agency reasoning supporting previous EPA interpretations that only gases in containers may be considered "contained." Based on the facts of this case, EPA cannot see how gaseous secondary material that is generated in any particular system and is somehow sent to a gas-fired boiler, even through a pipeline, can be considered an "uncontained gas."This even assumes that "uncontained gas" is not covered under the definition of solid waste, which EPA does not concede in this rulemaking. This would mean that a clean gas-fired boiler could still burn under  CAA 112 secondary  material that  is handled  through a seriously leaking  pipeline, has little to no  real  fuel  value, and is full  of dirty  contamination, simply because the material is not a "contained gas" under  the definition  of solid waste. EPA rejects any such formulation.
The EPA appears to provide greater assurances later in the preamble when it refers to the letter to American Forest & Paper Association, 80473. Here the EPA states that the burning of gaseous material in a combustion unit, not limited to air pollution control devices is not an a form of treatment or other management of solid waste. This certainly is helpful. Nonetheless this is a very important issue and one we would like as much certainty as possible about. The boilers at the Valdez Marine Terminal (VMT) burn vapors (gases) generated from storage tanks and the loading of tankers. These vapors consist predominately of hydrocarbon vapors and a limited amount of stack gas from the tankers and the boilers that is used as an inert gas for these vapor collection systems. We wish to utilize the control device exemption in the Boiler standards, but are concerned that the EPA may in time classify the vapors as solid waste or at least require that we must demonstrate the vapors are non-traditional fuels through the legitimacy criteria.
Logically, it makes sense that a boiler that acts as a control device under some other part, in our case, Marine Loading and Organic Liquid Distribution MACTs, should be exempt from CISWI. Indeed as we discussed above Boiler MACT provides an exemption for boilers used as control devices provided the gases contribute more than 50% of the boiler's heat input. To eliminate this confusion and future compliance and Title V permitting risks it would be ideal if the EPA simply created an exemption from CISWI for air pollution control devices and boilers and process heaters that are used as control devices under Parts 63, 61 and 60. Alternatively, the EPA could as a matter of interpretation make such a statement in the preamble or response to comments.
 3. Exclusion of Cyclonic Burn Barrels, Soil Treatment Units, Laboratory Analysis Units and Space Heaters from CISWI
Alyeska strongly supports the retention of the exemptions for cyclonic burn barrels, soil treatment units, laboratory analysis units, and space heaters. Since the function and operation of these types of units is fundamentally different than incinerators contemplated under the CAA, Alyeska supports the EPA's decision to exclude them from CISWI.
Response: This comment pertains to the CISWI rulemaking, and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the CISWI rulemaking docket (EPA-HQ-OAR-2003-0119), the response to this comment will be provided there.
Commenter Name: Randal G. Oswald
Commenter Affiliation: Integrys Energy Group
Document Control Number: EPA-HQ-OAR-2006-0790-2472-A2
Comment Excerpt Number: 6
Comment: Integrys supports the EPA's proposed clarification of the definition of biomass in the proposed reconsideration of the new source performance standards (NSPS) and emission guidelines for commercial and industrial solid waste incineration units[1], which would establish how bio-based fuels are treated under the Area Source Boiler Rule. The clarification will remove a barrier to expanding the use of several promising biomass fuel sources.
Response: This comment pertains to the CISWI rulemaking, and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the CISWI rulemaking docket (EPA-HQ-OAR-2003-0119), the response to this comment will be provided there.
Commenter Name: Stuart A. Clark
Commenter Affiliation: State of Washington Department of Ecology
Document Control Number: EPA-HQ-OAR-2006-0790-2481-A2
Comment Excerpt Number: 2
Comment: We are pleased that the preamble to the proposed CISWI Rule indicates the rule is being modified to clarify which biomass fuels (i.e. waste wood from forest harvesting) are not solid waste. However, the rule amendment could make this more explicit by specifically listing these materials as fuels.
A key consideration when assessing whether a material meets the legitimacy criteria is determining whether the material has been "discarded". The regulated community would benefit by either adding a definition of "discarded" that is not ambiguous or by issuing a Clarification Letter explaining how this determination will be made by the Agency. This is especially important when considering the status of materials collected through programs designed to divert useful materials from landfill disposal that can otherwise be processed into legitimate fuels or feedstock.
While acknowledging efforts to ensure expeditious review of petitions to the regional director for a non-waste determination, we believe the value of the opportunity for public comment outweighs the burden of a 30-day delay in completing the petition process.
We are pleased that the EPA proposed to segregate coal fired energy recovery units from other non-hazardous waste, biomass based energy recovery units under the CISWI Rule. This segregation will provide much more appropriate alignment of HAP emission limits with the type of fuel.
Response: This comment pertains to the CISWI rulemaking, and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the CISWI rulemaking docket (EPA-HQ-OAR-2003-0119), the response to this comment will be provided there.
Commenter Name: Stuart A. Clark
Commenter Affiliation: State of Washington Department of Ecology
Document Control Number: EPA-HQ-OAR-2006-0790-2481-A2
Comment Excerpt Number: 3
Comment: We are pleased that the preamble to the proposed CISWI Rule indicates the rule is being modified to clarify which biomass fuels (i.e. waste wood from forest harvesting) are not solid waste. However, the rule amendment could make this more explicit by specifically listing these materials as fuels.
A key consideration when assessing whether a material meets the legitimacy criteria is determining whether the material has been "discarded". The regulated community would benefit by either adding a definition of "discarded" that is not ambiguous or by issuing a clarification letter explaining how this determination will be made by the Agency. This is especially important when considering the status of materials collected through programs designed to divert useful materials from landfill disposal that can otherwise be processed into legitimate fuels or feedstock.
While acknowledging efforts to ensure expeditious review of petitions to the regional director for a non-waste determination, we believe the value of the opportunity for public comment outweighs the burden of a 30-day delay in completing the petition process.
We are pleased that the EPA proposed to segregate coal-fired energy recovery units from other non-hazardous waste, biomass based energy recovery units under the CISWI Rule. This segregation will provide much more appropriate alignment of HAP emission limits with the type of fuel.
Response: This comment pertains to the CISWI rulemaking, and it is out of scope for the Area Source Boiler rulemaking. Provided the commenter has submitted this comment to the CISWI rulemaking docket (EPA-HQ-OAR-2003-0119), the response to this comment will be provided there.
Commenter Name: Alicia Meads
Commenter Affiliation: National Association of Manufacturers (NAM)
Document Control Number: EPA-HQ-OAR-2006-0790-2446-A1
Comment Excerpt Number: 5
Comment: The NAM agrees with the EPA's decision not to apply the proposed incinerator MACT standards to small "burn-off ovens." (76 FR 80460.) In addition to the reasons identified by the EPA, it is not appropriate to categorize burn-off ovens as incinerators, as most burn-off ovens are not actually combusting material. Instead they use lower temperature processes such as melting or pyrolysis and are specifically designed to avoid flaming conditions, which would damage the parts being cleaned.
Response: The EPA thanks the commenter for their support and additional justification.
Out of Scope: Major Source Boiler Rule
Commenter Name: Barry Christensen
Commenter Affiliation: Occidental Chemical Corporation (OCC)
Document Control Number: EPA-HQ-OAR-2006-0790-2435-A1
Comment Excerpt Number: 8
Comment: Work practice standards, including operating the boiler according to the manufacturer's recommendations to ensure good combustion, along with periodic tune-ups, is the most effective way to regulate boilers operating in standby mode. One solution would be for the EPA to expand the definition of "limited-use boiler" to include standby units that consistently operate at low capacity.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Timothy Serie
Commenter Affiliation: American Coatings Association (ACA)
Document Control Number: EPA-HQ-OAR-2006-0790-2437-A1
Comment Excerpt Number: 9
Comment: ACA generally supports the following proposed changes in the Boiler MACT Rule:
1. Revision that sources have the option of either meeting a total selected metals (TSM) limit for each category or alternative particulate matter (PM) limits;
2. Revision that dioxin/furan emissions will now be regulated using a work practice standard in lieu of numeric emission limits;
3. Change to the boiler efficiency analysis allowing for the use of output-based limits as a compliance option to achieve emissions reductions in addition to the input-based limits;
4. Proposed separate subcategories for heavy liquid-fired and light liquid-fired units for PM and carbon monoxide (CO), dependent on combustor design;
5. Proposed fuel specification based only on the mercury (Hg) level in the gaseous fuel, and not hydrogen sulfide;
6. Establishment of a subcategory and separate standards for limited-use units that operate for shorter periods of time;
7. Change to the use of a 30-day rolling average for parameter monitoring and demonstration of continuous compliance with operating limits;
8. EPA's proposed alternative compliance option for facilities that wish to use CO continuous emissions monitoring system (CEMS) instead of CO stack testing and oxygen (O2) monitoring, so long as EPA clarifies that a source is not subject to the stack test-based CO standard if it chooses to comply with alternative CEMS-based limits;
9. Proposal that tune-ups for units (equal to or less than 5 million British thermal units per hour (MMBtu/hr)) will now only be required by the compliance date and every 5 years thereafter;
10. Exemption for any boiler or process heater that is used as a control device to comply with standards issued under Part 60, Part 61, or Part 63 of the CAA (provided that at least 50% of the heat input to the boiler is provided by a gas stream that is subject to the standards under those parts);
11. Exclusion of waste heat boilers and process heaters;
12. Exemption of residential boilers from the rule;
13. Extending the compliance date for existing sources to 3 years after the date of publication of the final reconsideration of the rule; although ACA urges the EPA to be flexible and allow affected sources more than three years to comply with the rules, if needed;
14. Revised definition of natural gas curtailment to clarify that a curtailment does not include normal market fluctuations in the price of gas that are not associated with periods of supplier delivery restrictions; however, the term "halted" may be interpreted to interfere with existing contractual obligations and therefore is too restrictive. ACA recommends that the EPA incorporate the language changes suggested by the American Chemistry Council;
15. Incorporation of an emissions averaging provision into the emissions standard.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Timothy Serie
Commenter Affiliation: American Coatings Association (ACA)
Document Control Number: EPA-HQ-OAR-2006-0790-2437-A1
Comment Excerpt Number: 10
Comment: ACA generally supports the following proposed changes to the MACT and Area Source Boiler Rules:
MACT  -  The EPA clarification that the scope of the energy assessments is to be limited to those facilities and equipment associated with the energy output from the regulated boilers and process heaters. ACA suggests that the EPA should eliminate the definitions of "boiler system" and "energy use system" and further limit the scope of energy assessments to "boiler(s)" and "process heater(s)" as currently defined;
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: David P. Tenny
Commenter Affiliation: National Alliance of Forest Owners (NAFO)
Document Control Number: EPA-HQ-OAR-2006-0790-2440-A1
Comment Excerpt Number: 2
Comment:  III.  Proposed Emissions Limits for Major Sources
Even if the EPA properly finalizes the regulations in a way that classifies biomass energy feedstocks as non-waste, this clean, renewable, and climate-beneficial energy supply will not be developed without significant changes to the current emissions limits imposed on biomass boilers under the Major Source Boiler Rule. Despite the fact that biomass energy is a clean, renewable alternative to fossil fuel combustion, the current regulations impose stringent emissions limits on biomass boilers that will require installation of expensive control technology while providing minimal (and sometimes undetectable) environmental and health benefits. Unless changes are made to the existing emissions limits, the high costs of compliance for biomass boilers will inevitably cause energy producers to turn to fossil fuel alternatives with lower compliance costs.
The proposed changes to the Major Source Boiler Rule offer a number of improvements that will reduce compliance costs without sacrificing environmental and health benefits, particularly with respect to dioxin/furan emissions limits and the standards for new biomass boilers. However, these changes will not be sufficient to properly encourage and incentivize biomass energy development. NAFO urges the EPA to consider additional changes with respect to emissions limits for other HAPs  -  including PM standards for existing boilers. Without additional changes, future growth in the biomass energy sector will be discouraged and the potential climate benefits of biomass energy will not be fully realized.
A. Work Practice Standards for Dioxin/Furan and Mercury, 40 CFR Part 63, Subpart DDDDD, Table 3
In its Major Source Boiler Rule comments, NAFO urged the EPA to adopt work practice standards for dioxin/furan. For the same reasons, the EPA should adopt work practice standards in lieu of emissions limits for Hg emissions from biomass boilers. As explained in our Major Source Boiler Rule comments, the EPA's proposed Hg emissions limits were also below detection limits and would require expensive control technology while providing little if any health benefit.
As the EPA recognizes, baseline dioxin/furan emissions from biomass are already extremely low and, in many cases, are below detection limits. As a result, stringent emissions limits, such as those currently in effect, will require the installation of extremely expensive control technology while providing little if any health benefit. Further given the current detection limits, it will be impossible to distinguish between compliant and non-compliant facilities. For these reasons, we support the EPA's proposal invoking its authority under §112(h)(2)(B) of the CAA to issue work practice standards in lieu of emissions limits for dioxin/furan emission. Thus, the EPA should also adopt work practice standards in lieu of emissions limits for Hg emissions from biomass boilers.
B. Emissions Limits for Particulate Matter, 40 CFR Part 63, Subpart DDDDD, Tables 1-2
While the EPA's proposed revisions to the PM emissions limits demonstrate an attempt at increasing flexibility and reducing regulatory burdens, it fails to produce this effect for many existing biomass boilers. The EPA's decision to create PM subcategories for coal- and biomass-fired boilers resulted in uneven results and in several cases we are concerned that the emissions limits included in the proposed rule remain too stringent. As explained in our prior comments, the current PM emissions limits will require biomass facilities to install costly new control technology and incur higher operating costs, creating a risk that facilities will avoid biomass fuels and turn instead to fossil fuel alternatives. But, rather than relieving this burden, the proposed PM emissions limits for existing "stokers/sloped grate/others designed to burn wet biomass fuel"  -  the most common type of biomass boiler currently in use  -  are actually more stringent than those under the current rule. Further reductions in PM emissions limits for the majority of existing biomass boilers will have a significant and detrimental effect on the viability of these boilers as alternatives to fossil fuel boilers. The wood products industry, which employs the majority of the wet stoker boilers, was significantly impacted by the recession and is still struggling to recover. The EPA must reassess the emissions limits for existing wet biomass stoker boilers and adopt more reasonable standards that can be achieved in practice and will satisfy legal requirements, without prohibitive costs that will further threaten the health and viability of this important industry.
C. Emissions Limits for other HAP, 40 CFR Part 63, Subpart DDDDD, Tables 1-2
Finally, with respect to the remaining emissions limits included in the proposed Major Source Boiler (and CISWI) Rules, NAFO urges the EPA to consider both the necessity of imposing stringent emissions limits on biomass boilers from a public health perspective as well as the impact that expensive control technology will have in discouraging the use of this clean, renewable, and climate-beneficial energy source. While the EPA's proposed emissions limits represent, in some cases, an improvement over current standards, they do not go far enough in correcting the flaws in the current rule.
NAFO supports the EPA's proposal to impose less stringent emissions standards on new biomass boilers. This proposal remains consistent with the EPA's legal obligations under §112 of the CAA, while removing compliance-based barriers to bioenergy development. With the exception of Hg, which is discussed above, the proposed emissions limits for new boilers represent a marked improvement over current standards and, at a minimum, we urge the EPA to adopt these standards.  Nevertheless, in order to properly reflect the health and climate benefits of biomass and provide proper incentives for the continued development of this important source of energy, the EPA must make additional modifications beyond its current proposals. Therefore, we reiterate and incorporate herein our previous comments urging alternative and less stringent emissions limitations for biomass boilers and incinerator units.
:: First, we urge the EPA to adopt health-based compliance alternatives for hydrogen chloride (HCl) and manganese under §112(d)(4) of the CAA in order to provide environmental health benefits while avoiding extreme costs to the industry. Biomass contains very small amounts of HCl and the proposed numerical standards will require expensive technological adjustments that provide very little benefit to public health or the environment. In addition, the EPA has long recognized that manganese is emitted from many facilities in amounts that do not expose anyone in surrounding population to concentrations above the established health thresholds and therefore the emissions do not pose a significant risk to the surrounding population.
:: Second, we urge the EPA to adopt more reasonable emissions limits for CO and PM that are less stringent and less costly, but still achieve statutory requirements. Again, the costs required to meet the proposed emissions limits are unreasonably high in comparison to the public health and environmental benefits that will accrue. The EPA can encourage, rather than discourage, the use of clean, renewable biomass fuels by imposing less stringent standards that will still comply with the EPA's statutory mandates under the CAA. Providing an alternative health-based approach will ensure that high compliance costs are not imposed on the industry unless commensurate health benefits are provided.
:: Third, we urge the EPA to focus on emissions standards that can actually be achieved in practice by considering all relevant pollutant emissions together rather than adopting a pollutant-by-pollutant approach that ignores trade-offs between emission control technologies and produces standards that cannot currently by met by any biomass boilers. The EPA establishes the maximum achievable control technology (MACT) floor for each source category by calculating the numerical average of the emissions from the best performing (lowest emitting) 12% of sources. By adopting a pollutant-by-pollutant approach, the EPA selects different sources as the best performing 12% for each pollutant and ignores the trade-offs that inevitably occur when some emissions are minimized at the expense of others. When all of the MACT standards are evaluated together, they do not reflect the actual emissions of the best performing sources.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Robert D. Bessette
Commenter Affiliation: Council of Industrial Boiler Owners (CIBO)
Document Control Number: EPA-HQ-OAR-2006-0790-2443-A2
Comment Excerpt Number: 20
Comment: EPA Should Not Include a 10% Discount Factor in the Final Major Source Boiler Rule
The EPA includes a restriction on emissions averaging that requires facilities using that option to meet a standard that is 10% stricter than the otherwise applicable limits. (76 FR 15670.) The EPA should not include this 10% penalty for using emissions averaging because it is arbitrary, unnecessary for environmental protection and reduces the flexibility that averaging provides.  Given the accuracy of heat input weighted emission calculations, there is no uncertainty that the average emission rates will be any less stringent than when not using averaging. Because the EPA has already determined that the standards in the rule achieve the maximum emission reduction achievable for health and environmental protection, to require an additional 10% reduction of emissions has no basis in the environmental underpinnings of the rule. Because emissions averaging is a compliance alternative, the 10% discount factor would constitute a beyond-the floor requirement. Although the 10% discount may be perceived as a fair trade-off for the flexibility of emissions averaging, it still lacks a legal basis and creates a disincentive for sources to use this compliance method. Where, as here, proposed emission limits are very tight, sources will not be able to ensure an additional 10% reduction in emissions below the limits and imposing this penalty effectively would deprive many sources of the availability of the emissions averaging compliance alternative.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Robert D. Bessette
Commenter Affiliation: Council of Industrial Boiler Owners (CIBO)
Document Control Number: EPA-HQ-OAR-2006-0790-2443-A1
Comment Excerpt Number: 54
Comment: CIBO opposes the EPA's decision to retain the 10% discount imposed on sources that decide to average their emissions data to comply with standards. (76 FR 80,633.)
The restriction is arbitrary and capricious. Given the accuracy of heat input weighted emission calculations, there is no uncertainty that the average emission rates will be any less stringent than when not using averaging. Because the EPA has already determined that the standards in the rule achieve the maximum emission reduction achievable for health and environmental protection, to require an additional 10% reduction of emissions has no basis in the environmental underpinnings of the rule. Because emissions averaging is a compliance alternative, the 10% discount factor would constitute a beyond-the floor requirement.
Although the 10% discount may be perceived as a trade-off for the flexibility of emissions averaging, it still lacks a legal basis and creates a disincentive for sources to use this compliance method. Where, as here, proposed emission limits are very tight, some sources will not be able to ensure an additional 10% reduction in emissions below the limits and imposing this penalty effectively would deprive them of the availability of the emissions averaging compliance alternative.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Robert D. Bessette
Commenter Affiliation: Council of Industrial Boiler Owners (CIBO)
Document Control Number: EPA-HQ-OAR-2006-0790-2443-A2
Comment Excerpt Number: 32
Comment: A. EPA Should Clarify Subpart DDDDD, Table 7 - Demonstrating Continuous Compliance
Subpart DDDDD, Table 7, Item 1.c. includes the word "block" in stating the following requirement: "Maintaining opacity to less than or equal to 10% (daily block average)." (76 FR 15605.) It appears that other similar requirements do not include the word "block" in the compliance requirement statement. Considering this, the EPA should revise the following items in Table 7 as noted below for clarity and to reduce potential confusion: 3.c. "Maintaining the 12-hour block average pressure drop..." 4.c. "Maintaining the 12-hour block average sorbent or carbon injection rate..." 5.c. "Maintaining the 12-hour block average secondary amperage and voltage, or total power input..." 7.b. "Maintaining the 12-hour block average oxygen content..."
B. EPA Should Clarify the Requirements of Section 63. 11220
It appears that there are conflicting requirements in §63.11220. (76 FR 15594.) Specifically, paragraph (a) requires triennial performance tests; however, paragraphs (b) and (c) incorporate the wording from Subpart DDDDD relative to 3 consecutive years' results <=75% of emission the limit in order to go to triennial testing. Considering this, the EPA should delete §§63.11220(b) and 63.11220(c) to eliminate incorrect and conflicting statements.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Alicia Meads
Commenter Affiliation: National Association of Manufacturers (NAM)
Document Control Number: EPA-HQ-OAR-2006-0790-2446-A1
Comment Excerpt Number: 2
Comment: Some standards in the proposed rules are more stringent than prior iterations of the rules, the total costs of compliance has increased several hundred of million dollars for manufacturers, and some limits may not be achievable, especially within the current 3-year compliance timeframe. For example, the particulate standards are more stringent for the predominant boilers in the forest products industry (wet biomass stoker boilers). In addition, the EPA has made the standards for coal and coal-biomass boilers significantly more costly. As a result, these proposed rules jeopardize more than 200,000 critically needed jobs.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Alicia Meads
Commenter Affiliation: National Association of Manufacturers (NAM)
Document Control Number: EPA-HQ-OAR-2006-0790-2446-A1
Comment Excerpt Number: 4
Comment: I. The NAM supports the EPA's decision to establish work practice standards in lieu of emission limits for certain gas-fired boilers, for dioxin/furan and for periods of startup and shutdown
The EPA has properly exercised its authority by proposing to rely on work practice standards in lieu of emission limits for certain gas-fired boilers (units that combust only natural gas, refinery gas, or equivalent fuel (other gas that qualifies as Gas 1 fuel)). (76 FR 80601.) The EPA is also proposing a work practice standard for dioxin/furan emissions from all subcategories. Id. at 80602. In addition, the EPA is proposing revised work practice standards for periods of startup and shutdown. Id. at 80602. By taking these steps, the EPA will help to make sure that these rules do not unduly harm segments of the nation's critical manufacturing base.
The EPA has ample legal authority to set the standard in terms of a work practice. First, CAA §112(d)(1) authorizes  -  if not requires  -  the EPA to set "emission standards" for each category or subcategory, and CAA §302(k) defines "emission standard" to include work practice standards. Thus, if the EPA determines that the best performing sources achieved their emissions performance through work practices rather than control equipment, those work practices should be identified as the "floor." Second, CAA §112(h)(2)(b) independently authorizes the EPA to use a work practice standard where, as here, the application of a system for measuring the effect of the control measure for enforcement purposes is not practicable.
The EPA has independent authority to promulgate work practices as emission standards under CAA §302(k) as long as the work practices provide a continuous limit on emissions or are part of a set of regulations that provide a continuous limit on emissions. As required by CAA §112(d), the EPA must promulgate "emission standards" for the control of HAP at major sources. Originally, these "emission standards" were found to be limited to only numeric emission limits. (See, e.g., Adamo Wrecking Co. v. U.S., 434 U.S. 275 (1978).) However, in the 1990 Amendments, Congress expanded the definition of "emission standards" in §302(k) to expressly include work practices. As a result, the plain language of the CAA now authorizes the promulgation of work practices: (1) as direct emission standards under §302(k), and (2) in lieu of emission standards under CAA §112(h).
That statutory authority greatly simplifies the development of work practice standards for boiler units. Instead of turning to the alternate stop-gap provisions in CAA §112(h) that apply when continuous emissions standards are not feasible, the EPA can focus on the direct establishment of work practices that existing sources use to ensure continuous compliance under CAA §§112(d) and 302(k). For example, if the top 12% of existing natural gas-fired boilers are using tune-ups to achieve their "best performing" status, then the EPA has the authority to establish that protocol as a work practice-based emission standard. Tune-ups are an appropriate emission standard for these units because, if conducted with adequate frequency, they provide continuous reduction of the quantity and rate of HAP emissions from boilers by ensuring that they operate properly.
The NAM agrees with the EPA's conclusions regarding the basis for relying on work practices for units that combust only natural gas, refinery gas, or equivalent fuels. As the EPA recognizes, the capital cost of emissions controls for the numerous existing gas-fired boilers would be extraordinarily high. (See 75 FR 32025, 32029.) Further, the EPA correctly concluded that imposing emission limitations on gas-fired boilers would create a disincentive for switching to gas from oil, coal or biomass as a control technique. Id. In fact, it could create an incentive for facilities to switch away from gas to other fuels. Both outcomes should be avoided. Finally, the EPA recognized that "[t]he inability to accurately measure emission from Gas 1 units and the related economic impracticability associated with measuring levels that are so low that even carefully conducted tests do not accurately measure emissions warrant setting a work practice standard under CAA section 112(h)." (76 FR 15638.)
In addition, the EPA is correct that work practices are appropriate for dioxin/furan, as the large majority of the dioxin/furan measurements are below the level that can be accurately measured. (76 FR 80606.) This is consistent with the approach that the EPA correctly took in the recently finalized Mercury and Air Toxics Standard (MATS).
Finally, the NAM agrees with the EPA's rationale for justifying work practice standards for periods of startup and shutdown, as described in the preamble to the final rule. (76 FR 15642.) The EPA's rationale, along with the concerns raised in prior comments by the NAM and others, justify reliance on work practices.
II. The NAM supports the EPA's creation of additional subcategories
The CAA unequivocally authorizes the EPA to establish appropriate subcategories of sources. CAA §112(c)(1) instructs the EPA to establish "categories and subcategories" of sources for regulation under §112. CAA §112(d)(1) then further provides that the EPA "may distinguish among classes, types and sizes of sources within a category or subcategory" when establishing MACT standards. These provisions vest the EPA with the clear authority to group like units for purposes of establishing emissions limitations. Further, the EPA's ability to subcategorize is a key tool in ensuring that MACT floors are achievable. See Sierra Club v. EPA, 479 F.3d 875, 884-85 (D.C. Cir. 2007) (Judge Williams' concurrence noting the need to use subcategorization to avoid imposing unreasonable or unachievable MACT floors).
Thus, the NAM supports the EPA's conclusion that certain additional subcategories are warranted. For example, the EPA's division of the liquid subcategory into light and heavy liquid subcategories for PM and CO is warranted because of the differences in equipment design, operations and emissions between the subcategories. In addition, the EPA's establishment of a limited-use subcategory subject to work practices is warranted for a variety of reasons previously highlighted by the NAM, including the fact that these units spend a far greater percentage of their time starting up and shutting down than other units, leading to different emission profiles and control options.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Alicia Meads
Commenter Affiliation: National Association of Manufacturers (NAM)
Document Control Number: EPA-HQ-OAR-2006-0790-2446-A1
Comment Excerpt Number: 18
Comment: The NAM supports the EPA's proposal to allow a co-fired unit to opt out of the CISWI Rule and into the Boiler MACT Rule, or visa versa. This will provide a beneficial measure of flexibility to operators. However, the EPA should eliminate the arbitrary restriction in the proposal that would limit a facility from moving from being regulated under CISWI to being regulated under Boiler MACT for a six-month period after it had stopped burning solid waste. As a policy matter, forcing operators to remain regulated under the one standard when there are reasons to switch would needlessly penalize them with little to no benefit gained.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: Carl R. Rutz
Commenter Affiliation: Alyeska Pipeline Service Company
Document Control Number: EPA-HQ-OAR-2006-0790-2447-A2
Comment Excerpt Number: 1
Comment: II. COMMENTS ON MAJOR SOURCE BOILER MACT
 1. Time Allowed to Comply with Boiler MACT Should be 5 Years not 3 Years
Alyeska strongly supports the American Petroleum Institute (API) comments on this topic. Our organization has been evaluating the time frame necessary to comply with Boiler MACT, assuming the final rule is similar to the present vacated final rule and this proposed rule. The 3-year timeline will be extraordinarily difficult to meet because the modifications required of the boiler facility to provide for controls are very challenging. After those changes, the addition of emission controls will be equally dlifficult and time consuming. We are not optimistic we can meet a 3-year timeframe to perform this project. We are without other options for power for the VMT so any project is particularly challenging because it directly impacts the ability of the facility to perform its primary function of storing oil and loading it on to marine tankers.
2. Control Device Exemption, 40 CFR 63.7491(i)
Along with API and its members Alyeska thanks the EPA for modifying the exemption to cover regulated gas streams under Parts 60 and 61. We also support API's additional requests for changes to help clarify the exemption.
Like all facilities that have regulated gas streams that are combusted as fuel in boilers subject to this standard it is very important that we clearly understand the application of this exemption. API's comments and requests for clarifying changes will do that. In addition, Alyeska asks the EPA to provide some discussion in the preamble to the final rule or in the response to comments to provide further certainty about this exemption. Our concern is that the current record on this exemption is sparse as to how it might actually apply at specific facilities. Currently the only example, and it is a complex one, is the Norboard Industries comment and the EPA's response:
 Norbord stated:
       "Many facilities exhaust process gases from other sources through the combustion chamber of a boiler or process heater.  Does the standard apply to all or a portion of the exhaust?  At one Norbord facility a portion of the process gases passing through the combustion unit is PCWP MACT regulated, and another portion of the gases passing through is from a kiln. Additionally, greater than 50% of the heat input to the boiler/process heater is from the kiln and dryers. At the very least wouldn't the boiler/process heater be considered a waste heat boiler?"
 The EPA responded as follows:
      "EPA  has modified the exemption to remove the phrase 'specifically listed'  and replaced with 'part of the affected source' in order to address the concerns of the commenter. Further we added another exemption to allow for situations where the boiler serves as the control device for another MACT-regulated process where at least 50% of the heat input comes from the regulated process."
We realize there are statements by the EPA in the preamble to the proposed rule reinforcing the benefit of the exemption. (76 FR 80615, 80616.)  However, what is less certain is how the exemption will effectively apply. For example, at the VMT vapors are collected and controlled as described above under 40 CFR 63 Subparts Y and EEEE. Our understanding is that these collected vapors are a regulated gas stream for purposes of the exemption. Further, the collected vapors are used as fuel in the boilers, and meet the definition of a "gaseous fuel" under §63.7575. The exemption also requires that the boiler perform as a control device to comply with another subpart. Subpart Y's emissions standard requires that a vapor collection system connect to an air pollution control device. Air pollution control device for purposes of Subpart Y expressly includes boilers. Boilers are used at the VMT as control devices. Under Subpart Y, large boilers above a certain size are not required to satisfy emissions testing, monitoring and performance criteria that the thermal oxidizers must meet. The EPA made that decision in the Subpart Y rulemaking because of the inherent combustion efficiency of boilers and the pollution prevention benefits of burning vapors for fuel in lieu of diesel or other fuels in the boilers. That is well documented in the rulemaking history. As you know, the EPA established this practice with the Hazardous Organic National Emission Standards for Hazardous Air Pollutants (NESHAP) (HON) and it has properly been added to many MACT standards. It is our understanding that the VMT boilers when used in this manner are used as a control device to comply with another subpart and therefore satisfy this requirement of the control device exemption.
We believe the same is true for Organic Liquids Distribution MACT (Subpart EEEE) at the VMT. Subpart EEEE, requires regulated vapors to be collected and routed to either to I) a dedicated air pollution control device, or 2) a fuel gas system followed by a combustion device. At the VMT, the dedicated control devices are thermal oxidizers; the combustion devices receiving regulated vapors via the fuel gas system are boilers (serving as control devices).
We would appreciate some discussion by the EPA to confirm our understanding of the scope of this exemption to circumstances like ours where boilers receiving regulated gases via a vapor collection system and/or fuel gas system serve as control devices.
3. Transitioning from the Control Device Exemption  to Complying with Boiler MACT
We are uncertain about how the exemption may practicably terminate for a boiler that is utilizing this exemption. If a boiler has been operating under the exemption at§63.7491(i) by burning over 50% gaseous fuel on a heat input basis from regulated gas streams and the regulated gas stream drops below 50% on an annual average (see comment below) how soon would the boiler have to meet the emission standards of the rule? Depending upon circumstances, a drop in the regulated gas stream heat input usage may not be foreseeable or avoidable. Gas streams that arise from processes may appear to be forecastable, but unforeseeable economic conditions or other events may change the supply of the underlying commodity that generates the gas stream. This in turn may result in a rapid unforeseeable diminishment in the gas stream volume and corresponding heat input to the boiler. If a facility has to retrofit boilers with emission controls sufficient time must be allowed to reasonably allow for the changes to be made. Therefore, Alyeska proposes that the EPA clarify this obligation and provide a reasonable time for installation of controls to the boilers. Based upon our review of the timeframe to make such a change at least three years will be needed after a boiler no longer qualifies for the exemption criteria to put in place the controls, monitoring and other requirements necessary to meet the rule's compliance obligations.
4. Alyeska Supports API's Request to Base "Heat Input" on an Annual Average
Alyeska supports determining the heat input on an annual average basis that is a further described as a rolling 12-consecutive month period. First, this approach is consistent with how annual averages are used in most EPA and state programs. For example, the Terminal's existing permit requirements to meet state SIP permit limits are based on this approach. Second, this approach seems logical because it provides for seasonal variability or other short term circumstances when regulated gas streams may be limited or the heat content of the gas changes. However, on an annual average the gas streams do contribute more than 50% of the heat input to the boilers. Since Alyeska believes it is the EPA's intent to promote the usage of on-site gas over other off-site fuels, such as liquid or solid fuels, which result in additional emissions, an annual basis would be beneficial and would not penalize a facility during the short periods the 50% criteria couldn't be met.
5. Startup and Shutdown Operating Regimes
Alyeska supports the EPA's recognition that the startup and shutdown of boilers are different from normal operation. Alyeska agrees with the API/National Petrochemical and Refiners Association (NPRA) comments that a work standard is the proper standard. For example, the VMT boilers must be run at their intermediate and upper ranges during part of startup to ensure proper tuning over the full operating range before being returned to normal service. For this reason startup will include periods when the boilers are operated at that or above 25%. Only a reasonable work practice approach ensures that boilers are started up safely and efficiently to ensure effective routine operations after startup.
Finally, there is no alternative fuel for these boilers. They can only operate on gaseous fuel as described above and on liquid distillate fuel, also described above. Prescribing a startup alternative fuel is not remotely feasible.
6. Malfunction Affirmative Defense
Alyeska strongly agrees with the API/INPRA comments regarding the heavy handed treatment of malfunctions in the proposed rule. The proposed text implies a presumption of guilt and imposes an unreasonable burden on the facility for each incident that may occur. The simple fact is that malfunctions will occur and no amount of planning or expense can completely eliminate them. Alyeska agrees that if a malfunction occurs and an emission limit is exceeded that the agency (either the EPA or the Title V delegated agency) should be provided notification of the event including a description of the event and the corrective actions taken at the time. However, Alyeska believes that the level of information necessary to "assert the affirmative defense" should only be necessary 1) if a facility has a history of having repetitive "similar type" exceedences, and 2) the information is specifically requested by the agency. The EPA and delegated state agencies should take an enforcement discretion approach instead of treating every incident as an enforcement case.
7. Clarification of Emission Monitoring and Emission Limit Compliance During Startup and Shutdown
We are concerned that there are interpretations of §§63.7535 through 63.7541 that could require that compliance requirements be met during periods of startup or shutdown. Specifically: §63.7500(e) states that the standards, except the work practice standards in Table 3, do not apply during periods of startup and shutdown, however, under the continuous compliance requirements §§63.7535 through 63.7541, there is no mention that data taken during episodes of startup or shutdown should not be considered or used in evaluating on-going emission or monitoring requirements. Several of the provisions, such as §63.7535(c) acknowledge that monitoring data taken during monitoring system malfunctions, out-of-control periods, or during repairs on the monitoring systems should not be used, but it is silent for periods when the boiler is in startup or shutdown. Another example includes §63.7540(a)(8) for CO CEMS which states under §63.7540(8)(ii) to "maintain a CO emission limit below or at your applicable alternative CO CEMS based standard in Tables 1 and Table 2 of this subpart at all times" (emphasis added).  Perhaps the means to address this concern would be to add to §§63.7535(d) and 63.7540(a)(ii): "except during periods of startup and shutdown as described by §63.7500(e)".
Another clarification which would be beneficial in the rule is to acknowledge the acceptability of using a single CO CEMS system to monitor multiple affected boilers simultaneously as long as the measurement criteria of at least one reading every 15 minutes per affected unit is met.
At the VMT, the three power boilers route to a common stack and since the rule does not provide a single CO limit for combined stack configurations, like it does for PM/HCl and Hg, it is implied that individual boiler CO exhaust measurements are required. In order to simplify the monitoring, reduce redundancy, and optimize limited space, Alyeska believes there would be benefit in this rule if the EPA acknowledged this option.
We supported 5 years for the initial compliance period for Boiler MACT, but recognize that later in the life of a boiler that a 3-year timeframe may be achievable if transitioning from the control device exemption to full Boiler MACT compliance, including the addition of controls. There will be considerable national experience developed by contractors to install controls and companies that utilize the exemption will have some anticipation and understanding of what Boiler MACT compliance looks like at these later dates.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: James Johnson
Commenter Affiliation: United States Beet Sugar Association (USBSA)
Document Control Number: EPA-HQ-OAR-2006-0790-2450-A1
Comment Excerpt Number: 5
Comment: The USBSA also requests that boilers located at major agricultural sources, which run only during the sugarbeet processing season, should receive treatment similar to that suggested above for area sources. These major sources are virtually identical (i.e. the same agricultural locations and production schedules) to the area sources except that process HAP emissions are only slightly over the major source threshold.
     . . . be included in the seasonal subcategory or in the alternative may be found to constitute a separate subcategory, and be permitted to comply with the final Boiler Rules using a management practices standard during normal operations as well as during startup, shutdown, and periods of malfunction. . .
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: James Johnson
Commenter Affiliation: United States Beet Sugar Association (USBSA)
Document Control Number: EPA-HQ-OAR-2006-0790-2450-A1
Comment Excerpt Number: 12
Comment: In the reconsideration of the Major Source Boiler Rule, the EPA has reconsidered several of the MACT floor limits.[14] However, the EPA retained the HAP-by-HAP approach of regulating each HAP separately, without regard to the interplay between pollutants and pollution-control equipment that can lower efficiencies and make it more difficult to meet the prescribed standards. A HAP-by-HAP approach --  using a pollutant-by-pollutant analysis that looks at the best performing sources for each HAP and sets the floor based on those sources --  creates challenges for regulated entities looking at the overall pollutant levels of their facilities.
Because a HAP-by-HAP approach looks at the pollutants piecemeal, it does not represent what an actual source can achieve over time. Setting the standard this way makes it exceedingly difficult for regulated entities working in good faith to improve efficiencies enough to meet the standards and doing so comes only at enormous cost. In addition, such an approach does not conform to §112 of the CAA because this section of the CAA speaks to regulating pollutants reflecting the performance of "sources," not individual pollutants seen in the abstract. As the D.C. Circuit has found, "EPA may not deviate from section 7412(d)(3)'s requirement that floors reflect what the best performers actually achieve."[15] Therefore, when setting the MACT floor, the EPA should use a rubric of the best controlled sources, not a HAP-by-HAP approach.
The use of a HAP-by-HAP approach and the resulting stringent standards will cause significant hardship for sugarbeet processing facilities that are major sources because it is extremely difficult to meet all the prescribed standards at the same boiler. The USBSA urges the EPA to reconsider such an approach given its adverse economic impact on seasonal, agricultural industries such as sugarbeet processors.
[14] 76 FR 80614.
[15] Cement Kiln Recycling Coal. v. EPA, 255 F.3d 855, 861 (D.C. Cir. 2001).
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: James Johnson
Commenter Affiliation: United States Beet Sugar Association (USBSA)
Document Control Number: EPA-HQ-OAR-2006-0790-2450-A1
Comment Excerpt Number: 13
Comment: The USBSA commends the EPA for altering the proposed Boiler MACT Rules in the reconsideration to allow for work practices standards during startup and shutdown,[16] as well as for the control of dioxins and furans. Work practices standards, as allowed under §112(h) of the CAA, maintain strong environmental protection while also including needed flexibility. Work practices can be utilized by the Agency "if it is not feasible in the judgment of the Administrator to prescribe or enforce an emission standard for control of a hazardous air pollutant or pollutants."[17]
In the case of dioxins and furans, work practices are appropriate because of difficulties in assessing compliance with a numerical limit. In the reconsideration of the Major Source Boiler Rule, the EPA acknowledged that a "large majority of all emissions measurements for all the subcategories are below the level that can be accurately measured using EPA method 23."[18] Therefore, work practices are appropriate in place of numeric limits for dioxins and furans, and USBSA is supportive of the EPA's adoption of work practices for these pollutants.
[16] Work practices for startup and shutdown for the Major Source Boiler Rule, 76 FR 80615.
[17] Clean Air Act, § 112(h); 42 U.S.C. § 7412(h).
[18] 76 FR 80606.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: James Johnson
Commenter Affiliation: United States Beet Sugar Association (USBSA)
Document Control Number: EPA-HQ-OAR-2006-0790-2450-A1
Comment Excerpt Number: 14
Comment: In the reconsideration of the Major Source Boiler Rule, the EPA proposed to reset the compliance date for existing sources such that it would reflect a timeline three years after the date of publication of the eventual final rule.[19] USBSA supports the EPA's approach for adjusting this compliance deadline. CAA §112(i)(3) allows for 3 years for compliance from the effective date of a final rule, and thus a revision to the compliance deadline in the rule is appropriate. There is currently a large amount of uncertainty in the regulated community surrounding the eventual shape of the Boiler Rules, and the EPA's approach seeks to provide affected sources with at least the full 3 years intended by §112(i)(3). Even with the adjustment to reflect the intent of §112(i)(3), however, USBSA members will have difficulty meeting the rule's very tight timeframe for compliance.
[19] 76 FR at 80605.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 6
Comment: In the final rule the EPA declined to correct the errors identified by NACAA and provided no explanation for its decision to persist in those errors. The EPA did, however, revise its calculation procedure, in response to comments from industry, and "pooled" the statistical variation shown by individual units. The public was not provided an opportunity to comment on this change, even though it led to a significant upward revision of a number of proposed limits. On reconsideration of the final rule, the EPA now proposes to retain the procedure used in the final rule and create additional subcategories for PM emissions, which would cause very large increases in PM limits for a number of subcategories of sources.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 7
Comment: The magnitude of these errors is demonstrated by two key facts. First, the EPA's methodology results in a situation where, in a majority of the EPA's proposed subcategories, the calculated new source MACT floor (based on the best performing unit) is higher (less stringent) than that for existing sources (based on the average of the top 12% of units in the subcategory). Common sense and basic arithmetic provide that the rate of emissions of the "best" unit (i.e., the lowest emitter in the group) must be less than the average of that unit and the emission rates of a group whose emissions are higher. At a minimum, the procedure adopted by the EPA must achieve this result.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 8
Comment: The EPA's methodology leads to emission limitations that are currently being met by almost all units subject to the regulation. This is inconsistent with the statutory requirement that the existing source MACT floor be set at the performance that reflects the 94[th] percentile (average of the top 12%) of the best performing units. A determination of the variability of each of the sources in the top 12% is a worthwhile goal. However, the cost of conducting sufficient testing to do so reliably for each of the sources in the top 12% of each of the large number of subcategories that the EPA proposes is too high for the benefit that would be achieved and would further delay issuance of final rules for several years.
The EPA did not design its test program with the subcategories it now proposes in mind and therefore did not require testing of a sufficient number of sources within each of the subcategories it is proposing. Thus, not only does the EPA not have sufficient data to determine the variability in the performance of each of the individual units in the group, in many instances it does not have sufficient data to reasonably apply statistics to the subgroup as a whole. In the most extreme instance the EPA acknowledges that it does not have any data for mercury for one of its proposed subcategories. The EPA also acknowledges that it does not have meaningful data for two of the regulated metals that should be included in its alternate TSM limit in any of its proposed subcategories.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 9
Comment: The EPA has proposed to retain its "work practice" standards for CO emissions for certain subcategories and for emissions of dioxins and furans for all subcategories on the basis that measuring emissions of these pollutants is impracticable. However, the EPA has not identified the specific work practices that the regulated community must employ. Given the complex nature of dioxins and furans formation, the development, implementation and enforcement of a meaningful dioxins and furans work practice requirement is itself impracticable. The fact that many sources have shown a "below the detection limit" (BDL) test result does not make such testing impracticable nor will such results be a violation. The EPA should address the issue of an unnecessary testing burden for "clean units" head on and not suggest that an unspecified work practice obligation will achieve the emission reductions. Where the EPA believes that emissions from some sources are truly insignificant, it should say so and use the authorities available to it for de minimis emissions.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 12
Comment: Replicate compliance method testing of the best performing units over a period of years and varying operating conditions would likely be the best method for determining which units are among the best performing units and for assessing the variability of the performance of such units. However, the EPA does not have such information and development of this information is infeasible at this time. Moreover, the EPA does not have sufficient data of any sort to make an accurate assessment of the variability of either individual units or subcategories with relatively limited data. As discussed earlier, the problem is readily apparent for new sources, where the EPA's attempts to determine the variability in the performance of the "best" unit based on a single reference test clearly produce an incorrect result. This problem also exists in a large number of existing source subcategories where the EPA has insufficient test data to apply its method. The EPA has acknowledged this problem and attempted to partially respond to it by using its "beyond the floor" MACT authority to raise the new source MACT limit to the level of the existing source MACT floor in 24 subcategories. While directionally correct, we believe it is unlikely that this will be found to be sufficient, since common sense and basic arithmetic demonstrate that the result is still wrong  -  the performance of the "best" individual unit cannot be the same as the average of the larger group. Moreover, the EPA does not make a similar adjustment to existing source MACT floors that are also based on limited data.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 13
Comment: In most, but not all instances, the EPA selects the test that leads to the least stringent MACT floor determination. Moreover, the basis for several key decisions respecting data management (discussed below) is not well supported. The lack of a consistent, reasoned basis for the EPA's choices creates a risk that the rule will be overturned and in some instances, the resulting floor calculation will be substantially different if other, equally reasonable, factors are used in developing the final determination. We discuss a number of these issues in detail below, but the impact of the EPA's new statistical approach in categories with relatively small numbers of tests is clearly illustrated by the Hg limit The EPA calculated for liquid-fired boilers. While these factors affect all of the EPA's MACT floor calculations, they are most apparent in the calculations for new sources, which, under the EPA's methodology, always involve single units with limited testing.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 18
Comment: Pooled variance is a method for estimating variance given several different samples taken in different circumstances where the mean may vary between samples but the true variance (or precision) is assumed to remain the same. Under the EPA's revised upper prediction limit (UPL) procedure, fuel analyses results are disaggregated from emission test results and further disaggregated by the number of unique sources. As a result, the method is highly sensitive to the number of tests and the number of units that are tested. However, in some subcategories the majority of the test and fuel analysis results were BDL and the detection limits for the emission test results are several times lower than those for the fuel analyses. The EPA's pooled variance process generates high levels of variability, based largely on differences in the degree of precision of the measuring process and the EPA's treatment of BDL data (where the results are known to be less than the BDL). This leads to unreasonable results where the sample size is relatively small. In addition to generating unrealistic results for a broad array of new source subcategories, the EPA's proposed new statistical approach also appears to lead to results for PM and CO that are not consistent with the in-use performance of units in a number of other subcategories with limited data.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 19
Comment: NACAA supports the development of subcategories in MACT rule development, where such subcategories are based on meaningful differences in anticipated fuels and unit designs. The EPA has received a significant number of comments from sources making general assertions and theoretical arguments in support of additional subcategories; accordingly, the Agency has proposed to greatly expand the number of subcategories for several pollutants. NACAA agrees that the EPA's proposal to establish four broad categories based on fuel type  -  coal, biomass, liquid and gas  -  is reasonable.
The EPA proposes, however, to subdivide these broad categories into 38 subcategories for existing and new units. In support of the explosion in the number of subcategories, the EPA explains the differences in design between, for example, a coal-fired stoker boiler and a coal-fired pulverized coal ("PC") boiler. However, large boilers do not come off an assembly line[12] and can last for up to 50 years. Almost every large boiler will have differences in design from every other large boiler. Even smaller boilers will have differences in design from small boilers produced by other manufacturers. As a result, it is insufficient to simply identify design differences. Where the EPA seeks to establish additional subcategories it must explain why those differences matter and point to information in the record that supports its conclusion.
For example, within the Boiler MACT "coal-fired" category, the EPA proposes separate subcategories for stoker, fluidized bed and pulverized coal designs. However, we know of no reason why well-controlled units of these designs should differ significantly in levels of HAP emissions. Similarly, the EPA proposes to establish seven subcategories of wood-fired boilers[13]  -  wet stoker, dry stoker, fluidized bed, suspension, dutch oven, fuel cell and hybrid suspension  -  based on differences in the design of the combustion chamber of these units. However, most boilers and. in particular, the best-performing units, are equipped with PM control devices ranging in effectiveness from cyclones and multi-cyclones to electrostatic precipitators (ESPs) and fabric filters. The performance of the installed PM control device governs the level of PM and TSM emissions to a far greater extent than differences in design of the combustion unit itself. Indeed, in the stoker/sloped/other dry biomass subcategory we note that each of the units in the subcategory is only served by cyclone or multiclone PM control devices, while in other subcategories most of the units are equipped with more effective fabric filer or ESP control devices. We do not believe that the EPA is authorized to create a class of "poorly controlled units" and recommend that no separate subcategories be authorized for PM or TSM.
Under the EPA's current and proposed procedures, creating larger numbers of subcategories usually leads to higher MACT floors in two ways. First, if a small number of the best performers (e.g., fuel cells) can be culled from a larger group into its own subcategory, the MACT floor for the larger group (the wood-fired boilers) will rise. Second, because the small group will have a small number of tests, the statistical variability of the small group will also increase, leading to MACT floor increases for both the larger group and the smaller group. The EPA's decision to create separate subcategories for PM emissions based on the design of the combustion chamber creates a situation where a unit with highly variable emissions is classified as a top performer, based on the EPA's inappropriate definition of best performing unit. Since that unit has many more test results than others in the group, the EPA's pooled UPL process causes that unit to dominate and results in a limit that is technically invalid. The resulting proposed limits are often substantially higher than the highest emitting unit. See Chart 1.
[12] Even mass-produced automobiles will exhibit design differences within and between models and manufacturers.
[13] NACAA has raised a concern that differences in the combustion properties of "wet" wood and "dry" wood might warrant development of a separate subcategory.
Response: This comment pertains to the Major Source Boiler rulemaking. Provided the commenter has submitted this comment to the Major Source Boiler rulemaking docket (EPA-HQ-OAR-2002-0058), the response to this comment will be provided there.
Commenter Name: S. William Becker
Commenter Affiliation: National Association of Clean Air Agencies (NACAA)
Document Control Number: EPA-HQ-OAR-2006-0790-2455-A1
Comment Excerpt Number: 25
Comment: The   EPA takes the result of its 99[th] percentile UPL calculation and applies a second variability factor, what it styles as a "fuel variability factor," to determine the overall variability to apply to a "best performing unit." This constitutes double counting and should not be permitted. This double counting occurs because fuel variability is part of, and in many instances the major part of, the test-to-test variability that forms the basis of the 99[th] percentile UPL calculation. In the case of the liquid-fired Hg limit, the EPA applied a "Fuel Variability Factor" to the 99[th] percentile UPL to further increase its proposed MACT floor to 2.6 x 10-5 pounds per MMBtu (lb/MMBtu). The EPA applies this factor, not because the data respecting the Hg fuel variability of the best units showed that the variability was too large, but because it was, in the EPA's view, too small. The EPA acknowledged that, for solid-fuel units, the variability in the amount of a pollutant in the fuel would be reflected in the emissions performance of the units but decided that "[f]or existing and new liquid fuel units, the fuels making up the best performing units demonstrated less variability in their composition and type, and there were a smaller pool of available test runs. The EPA determined that an additional fuel variability factor was necessary in these cases." The EPA's added emission factor makes only a slight (5%) difference in that case, but, if applied to solid fuel-fired units, would increase the standard by an order of magnitude.[22]
[22] Memorandum, Eastern Research Group to Shrager, B, USEPA, Revised MACT Floor Analysis (November 2011) for the Industrial, Commercial, and Institutional Boilers and Process Heaters National Emission Standards for Hazardous Air Pollutants  -  Major Source, November, 2011 ("MACT Floor Memo") Appendix C-4-(a)(i). p. 7.