Commenter 0256 said EPA's proposed distinction between the SO 2 " default requirement" and the " rebuttable presumption" based on total power plant capacity is unsupportable. Because BART applies on a unit basis, the fact that the total capacity of the plant is higher or lower than 750 MW has no obvious bearing on whether an individual unit can meet the default/ presumption. Indeed, if anything, units at a larger plant would perhaps have more problems meeting the presumption than would units at a smaller plant, because a larger plant would tend to have more units and thus more potential for space constraints in retrofitting add on controls. If EPA retains the SO 2 presumption, it should be a rebuttable presumption for all units greater than 250 MW, regardless of total power plant capacity.

In contrast, commenters ( 0227, 0271) said EPA should require presumptive controls for all units at 750 MW plants, including those between 250 and 750 MW. Commenter 0271 said this conforms to the specific wording of the Act ( Sec. 169A( b)( 2)( A)) for controls on these smaller than 750 MW units. Commenter 0267 supported applying the proposed presumptive level to all EGUs greater than 250 MW.

Comment: Commenter 0268 noted that Arizona has chosen to address visibility impairment through Section 309 of the 1999 RHR. In order to pursue the 309 pathway, Arizona has made a demonstration to EPA that the state will realize overall SO 2 reductions greater than the reductions that would be achieved solely through imposition of BART controls at the state's BART eligible sources. EPA should clearly and definitively recognize that presumptive BART limits for SO 2 do not apply to BART eligible sources located in states that have already committed to " better than BART" SO 2 reductions through Section 309 SIP submittals.

Comment: Twelve commenters suggested alternatives to presumptive control levels ( 0213, 0215, 0256, 0302, 28 255, 28 256, 28 264, 28 266, 28 278, 28 312, 28 355, 28 404). Commenter 0213 supports an emissions trading program to implement BART controls as proposed in the June 10, 2004 Clean Air Interstate Rule ( CAIR). However if an individual unit program is prescribed, the commenter supports a percent removal limit as opposed to an emission limit.

Commenter 0215 said EPA should retain the option of complying with the SO 2 default/ presumption for EGUs, either by adhering to the straight percentage reduction or a set 177 emission rate. Due to the variability in coal and equipment types ( including vintages), EPA must retain flexibility for those EGUs that must comply with these BART requirements.

Commenter 0256 agrees with EPA that, for units burning lower sulfur coal, achieving 95% reduction could be problematic and that an emission limitation should be used. Other commenters ( 28 256, 28 264, 28 266, 28 278, 28 312, 28 355, 28 404) agreed if a presumptive approach is used, then the presumptive norms should be explicitly stated in the rulemaking and should be no higher than 3.0 lb/ MWh for SO 2 ( 28 256), based on a weight rate limit or other fuel neutral basis to account for facilities burning higher sulfur coal ( 28 264, 28 335), on an emissions standard to allow sources to take credit for improvements they have already made ( 28 266, 28 278, 28 312, 28 404).

Commenter 0302 prefers the flexibility of a percentage control level comparable to a performance level of 0.1 to 0.15 lbs/ MMBTU SO 2. A percentage control level would offer the non EGU BART subject sources the best controls that are achievable, for all types of sources, under reasonable cost effectiveness. Without the proper guidance for BART subject sources that are EGUs, the commenter needs flexibility in determining the actual emission rates at which these sources will be required to demonstrate compliance.

Two commenters ( 28 255, 28 264) said the presumptive levels should not be established as absolute values. Commenter 28 255 said the values should be presented as a range. Commenter 28 264 said the presumption should not interfere with the states' discretion and statutory process. If EPA intends to apply this " presumptive level" as a mandate, then EPA should establish it as a national rule rather than continuing the pretense that states are making a case by case determination.

Comment: Three commenters discussed the role that the averaging period plays in determining performance ( 0213, 0256, 0314). Commenter 0213 noted the difference in performance over longer averaging times between state of the art technology and existing FGC installations. EPA should review existing installations to determine an appropriate level of performance for determining an SO 2 removal efficiency limit. Commenter 0256 said the choice of 0.15 lb/ MMBtu is predicated on the use of at least an averaging time of 30 day rolling or longer. The 0.15 lb/ MMBtu limit could not be achieved with the use of a shorter averaging time. Commenter 0314 asked that an averaging period, i. e., a 30 day rolling average, for the control levels be established in the rule. A longer averaging period will allow for lower annual emissions.

Comment: Four commenters said that EPA has underestimated the cost per ton of emissions removed ( 0187, 0206, 0236, 0303). Commenters ( 0187, 0236) provided an example of the costeffectiveness range for reducing SO 2 emissions to 0.1 to 0.15 lbs/ MMBTU estimated to be between $ 1800 and $ 3400 per ton of SO 2 removed when burning Powder River Basin coals. This is much higher than the $ 200$ 1000 per ton cost effectiveness range cited by EPA in support of 178 the proposed presumptive BART SO 2 limit. Commenter 0187 gave an example of an oil fired unit exceeding $ 3,000 per ton of SO 2 removed, which supports a separate presumptive SO 2 emission limit for oil based units based on the maximum fuel sulfur content in oil. Commenters ( 0206, 0303) were concerned about additional costs faced by smaller plants ( upgrading fans, piping, etc.) that can drive the cost into the $ 3,000 range. The commenters said EPA should treat smaller plants like other major sources and allow states greater flexibility in determining BART for such facilities.

In contrast, commenters ( 0221, 0267) said achieving the control levels are cost effective.

Comment: Six commenters provided other comments regarding SO 2 limits for utility boilers ( 0215, 0224, 0241, 0250, 0255, 0319). Commenter 0215 said if EPA retains the SO 2 default/ presumption, it should make it clear that if any source is willing to achieve 95% control or somewhere along the scale of 0.10 to 0.15 lb/ MMBtu, it should automatically be exempt from the requirement to perform a BART analysis for SO 2. Commenter 0224 said EPA might specify flue gas desulfurization as a presumptive technology. Commenter 0255 described several options that are available to further reduce SO 2 emissions and improve the reliability of existing FGD systems to above 95 % removal efficiencies.

Commenters ( 0241, 0250) opposed establishing any SO 2 control level for EGUs as presumptive BART because this usurps state authority and completely ignores the BART evaluation process required by the Act. Commenter 0250 said this is especially inappropriate for units already equipped with scrubbers.

Commenter 0319 was concerned that setting an emission rate goal incorporating cap and trade mechanisms rather than a percent control goal would encourage fuel switching to SPRB coal. Even plants that meet the BART standards would be encouraged to switch to SPRB coal to avoid capital investment or to profit from the sale of surplus allowances. Tribal coal and lignite production could be put at risk. The commenter provided a proposal to address the impacts on tribal coal as Attachment A.

<IP_ADDRESS> NO x Limits for Utility Boilers Comment: Eighteen commenters on the 2001 notice supported presumptive limits for NO x set at 90 to 95% ( 28 245, 28 247, 28 248, 28 255, 28 260, 28 262, 28 302, 28 325, 28 334, 28 338, 28 350, 28 352, 28 358, 28 362, 28 390, 28 399, 28 433, 28 7016). Commenter 28 302 said the combination of low NOx burner ( LNB) technology and SCR controls can routinely reduce NO x emissions by over 90% and other commenters cited research documenting the performance of controls ( 28 325, 28 390) and EPA's own experience and data ( 28 28 352, 28 362, 28 7016). 179 Commenter 28 256 said if a presumptive norm approach is used, then the presumptive norms should be explicitly stated in the rulemaking and should be no higher than 1.5 lb/ MWh for NO x..

Comment: Nine commenters addressed whether the NO x levels proposed in 2004 are too stringent ( 0167, 0171, 0207, 0227, 0231, 0232, 0255, 0271, 0302).

Two commenters supported the proposed NO x limit of 0.2 as a reasonable level of control ( 0231, 0302). Commenter 0232 supported the setting the presumptive control levels of NO x at 90%.

Three commenters said the proposed levels are too stringent ( 0171, 0207, 0227). Commenter 0171 described recent plant retrofits using low NO x burners and low NO x concentric firing systems that could not practically achieve the 0.2 lb/ MMBTU limit. Commenter 0207 said the presumptive limit is counter to available evidence and unreasonable, especially for T fired units equipped with low NO x burners. EPA's experience in the Acid Rain program is consistent with a higher emission rate and should be reflected in setting the BART levels. The commenter concluded that the experience of some of its members with low NO x burners, the background information for development of Group 1, Phase II NO x limits, and, most likely, the voluminous NO x x emission data reported to EPA from all Phase I and Phase II units, all demonstrate that a presumptive 0.2 lb/ MMBTU NO x emission limit for utility boilers is a very unreasonable, representation of BART for such units. Commenter 0227 was concerned that the NO x presumptive control level EPA proposed is higher than the level current technology can provide. EPA should review currently proposed NO x retrofits and consider lowering it presumptive level of 0.2 lbs/ MMBTU.

Three commenters said the proposed NO x levels are too lenient ( 0167, 0255, 0271). Commenter 0167 urged EPA to require electric generating units in the West to meet rigorous NO x pollution control standards. Commenter 0255 said the current suite of best available NO x technologies, post combustion as well as combustion controls, can achieve significantly lower emission rates than the proposed 0.2 lb/ MMBtu. In 2002 ozone season, the air pollution control industry had 100 units achieving a NO x emission rate of less than 0.2 lb/ MMBtu. Additionally, cost effective emission reductions from the industrial sector are feasible but have not been adequately considered in the BART rule considering the quantity of visibility impairing emissions. For industrial sources, setting an appropriate level of reduction with some flexibility such as providing the option of meeting an emission rate limit or percent reduction is one way to assure significant emission reductions. Commenter 0271 recommended the presumptive control level of 0.15 lbs. of NO x per MMBTU. This level of control has been demonstrated in the NO x budget program in the eastern United States.

Comment: 180 Six commenters said that the presumption is overly broad ( 0189, 0206, 0217, 0246, 0303, 0323). Commenters ( 0189) said that EPA should make clear ( a) that add on NO x controls should not be part of BART for non EGUs because of the costs of the these controls and ( b) that its presumptive control level of .2 lbs/ MMBTU does not apply to non EGUs because they are unable to meet these levels without the use of add on controls.

Other commenters ( 0206, 0303) said EPA should not establish a prescribed method of level of control because variations between small and large facilities, e. g., between coal, oil, and gasfired units, and the age of the units make application of such a presumption overbroad. Commenters ( 0217, 0246) also said disagreed with the presumptive NO x limit at 0.27 lb/ MMBTU because of the many differences in coal fired boilers. BART determinations should be made by individual states on a case by case basis, consistent with state discretion. Commenter 0323 said EPA should consider a range of emission rates that reflect recent advances in technology, particularly with respect to tangentially fired boilers at EGUs.

Three commenters said EPA's characterization of the capabilities of control technology is inaccurate. Commenters ( 0217, 0268) provided results of a survey showing the effect of adding advance combustion controls to existing units that currently do not have the most advanced controls. Expected NO x emissions rates ranged from 0.17 to 0.49 lbs/ MMBTU. The average emissions rate achievable, weighted by heat input, was 0.27 lbs/ MMBtu, well in excess of the presumed limit of 0.2 lbs/ MMBTU. In contrast, commenter 0255 described the effectiveness of SNCR as a candidate to meet or better the proposed emission rates.

Comment: Thirteen commenters said it is important to consider the type of coal or other fuel in setting a presumptive control level ( 0186, 0188, 0213, 0214, 0217, 0224, 0238, 0254, 0255, 0275, 0306, 0319, 0321).

Commenters ( 0186, 0275) said the 0.2 lb/ MMBTU presumptive level of NO x control should not apply to gas fired power plant boilers because combustion controls on gas fired units can achieve a much better ( i. e., lower) level of performance.

Other commenters ( 0188, 0214, 0238, 0319, 0321) said that the 0.2lb/ MMBTU level of control has not been demonstrated using SCR technology on lignite fired EGUs and cited current research supporting this claim ( 0188, 0321). Commenter 0238 added that over fired air will not reduce NO x emissions from cyclones to that level. Commenter 0321 said the proposed emission limit is not appropriate for lignite fired cyclone units either. Commenters ( 0214, 0238) added that EPA should give the states maximum flexibility to use the five statutory factors in their BART NO x determinations. Commenter 0306 said EPA should reexamine the presumptive BART for cyclone boilers firing North Dakota lignite. Commenters ( 0319, 0321) supported a recommendation for a NO x limit of approximately 0.4 lb/ MMBTU, or evaluated on a case by case basis. Commenter 0321 added that NO x emissions from lignite unite appear to have less impact on visibility in that region of the country. 181 Commenter 0217 said coal rank also accounts for differences in NO x levels. For example, subbituminous coal from the Powder River Basin has been shown to yield lower NO x in some units than other coals. However, this is not always true. In addition, unit operators must balance oxygen levels to attain proper NO x levels while still maintaining appropriate carbon monoxide ( CO) levels. A unit with a stringent CO emission limit may not allow a plant operator to achieve the lowest NO x level possible with existing controls.

Commenter 0213 said that cyclone boilers that burn bituminous coal may require a higher presumptive emission rate even after OFA retrofits. Commenter 0254 said pre NSPS boilers firing bituminous coal cannot meet the presumptive limit with the prescribed control systems ( combustion controls or low NO x burners). Commenter 0224 described different levels of performance between Western plants ( which could meet the limit) and Eastern plants ( which could not meet the limit). The commenter said any presumptive performance limits must reflect different types of coal and boiler configurations.

Commenter 0255 said the emission rate achieved from a particular unit depends on several factors, including coal type and boiler configuration. The commenter described several examples of high performing units.

Comment: One commenter ( 0270) cited studies showing the nitrates contribute only a few percent to total light extinction except in Class I areas downwind of Southern California. Accordingly, NO x emissions from stationary sources are unlikely to lead to any perceptible changes in visibility. Therefore, it is unlikely that NO x emission sources in the West will be good candidates of application of BART. The proposed presumptive NO x emission level is not consistent with the Bush Administration's publicly announced policy of " no SCR in the West" under the CSA. EPA should conclude that application of combustion based controls would constitute BART for NO x emissions in the West, irrespective of the resulting emission level.

Comment: Seven commenters said that the boiler configuration should be considered ( 0195, 0210, 0217, 0224, 0241, 0256, 0270). Commenters ( 0210) said, if retained, the NO x presumption should be modified to address the appropriate control levels for all boiler types. EPA's identified presumptive level, 0.2 lbs/ MMBTU, is not reasonable for most boiler types because it cannot be achieved without using combustion controls ( 0241, 0256, 0270). EPA could establish more reasonable levels by reviewing the emissions data readily available from the Acid Rain program ( 0210). Commenter 0241 said states should undertake a full BART analysis, as required by the Act, to determine the appropriate NO x control level that should be established as BART for EGUs. If a presumption is retained, EPA should change the presumption from a lb/ MMBtu emission limitation to a statement indicating that combustion controls installed after enactment of Title IV of the Act should be presumed to satisfy the BART requirement for NO x. States could then evaluate on a boiler specific basis the emission limitation that could be met using combustion controls. Any other approach is simply not justified by the data and would be arbitrary and capricious. 182 Commenter 0195 said NO x control on cyclone type boilers represent unique circumstances that make it virtually improbable to control on a long term basis below 0.4 lb/ MMBTU.

Commenter 0224 described different levels of performance between Western plants ( which could meet the limit) and Eastern plants ( which could not meet the limit). The commenter said any presumptive performance limits must reflect different types of coal and boiler configurations.

Commenter 0270 said it is well known that wall fired boilers can't achieve the same level of NO x controls as tangentially fired boilers with these types of control technologies. The commenter does not believe that a limit of 0.2 lbs/ MMBTU can be achieved on wall fired units via retrofit installation of advance combustion controls.

Comment: Three commenters ( 0195, 0252, 0271) provided other comments regarding applicability. Commenter 0195 supported the definitions for Combustion controls as defined in 40 CFR 76.2 Acid Rain Nitrogen Oxides Emission Reduction Program in order to provide consistency across EPA programs. Commenter 0252 analyzed data for eastern units and western units with different configurations and for units burning different types of coal. The commenter concluded that EPA should not set a presumptive level of control, since it should be determined on a case by case basis. Commenter 0271 said the presumptive level of control must be applied to all units at a " powerplant having a total generating capacity in excess of 750 megawatts" even those units less than 750 megawatts. This conforms to the specific wording of the Clean Air Act ( Sec. 169A( b)( 2)( A)) for controls on these smaller than 750 megawatt units.

Comment: Nineteen commenters discussed the use of post combustion controls ( 0171, 0179, 0199, 0206, 0217, 0221, 0224, 0232, 0234, 0244, 0246, 0252, 0253, 0255, 0256, 0267, 0271, 0280, 0303). Commenters supported the presumption that BART can be achieved without the use of post combustion controls ( 0199). However some types of units or units burning some types of fuel cannot meet the presumptive limits without installing controls ( 0199, 0217, 0244, 0252, 0253). Commenters described several examples.

Some commenters were concerned that the proposed rule would require some plants to install SCR to meet the NO x control level proposed ( 0171, 0206, 0217). Commenter 0171 said the implementation of the regional haze rule, including any potential retrofit of SCR technology, must consider the site specific data of the Class I area, the use of current emission controls on potential sources, and the degree of visibility improvements. Commenters ( 0217, 0246) added that individual EGU differences need to be accounted for by states in making their BART determination. Also, the guidelines indicate that if a state finds that a source's visibility contribution warrants the installation of SCR, it may be allowed. However, the guidelines need to also provide for instances where the visibility condition warrant a lesser control level than what would be achieved by advanced combustion control. There is reference to this concept in the 183 preamble that is not reflected in the guidelines. Commenters ( 0206, 0303) said the costs associated with SCR operations at coal fired power plants are not insignificant. Annual operation, rather than only during ozone season, would significantly reduce catalyst life, requiring more frequent replacement.

Commenters agreed that low NO x burners should be the presumptive technology because they are cost effective and the incremental cost of adding SCR or SNCR would be substantially less cost effective ( 0224).

Commenter 0255 said post combustion controls ( e. g. SCR and SNCR) as well as advanced ( or second generation) low NO x burners are significantly more efficient and are currently the best available control technologies for NO x. The majority of the low NOx burners currently on coalfired units were installed to meet the compliance deadline for the start of Phase I and II of the Acid Rain Program in 1995 and 2000, respectively. Units that installed their low NO x burners for Phase I of the Acid Rain Program will have had their air pollution control equipment in place for almost 20 years by the time the BART rule is implemented in 2013. Even the units that installed low NO x burners by 2000 will have had their equipment in place for over 10 years by 2013. Exemptions for existing low NO x burner equipment that is not meeting the 0.2 lb/ MMBtu emission rate should not be given as technology performance has significantly improved since 1995 and will continue to improve out to 2013. For these reasons, EPA should remove the provision that permits sources with first generation low NO x burners presumptive NO x emission rate and mandate that BARTeligible sources meet the 0.2 lb/ MMBTU or lower emission rate. Commenter 0255 also provided information showing that good performance of SCR on lignite burning units.

Some commenters approved of including year round SCR operation for removal of NO x ( 0179, 0221, 0232, 0234, 0271). Commenters ( 0232, 0234) would limit this application to sources already operating SCR. Commenter 0221 described how the technology has advanced, is cost effective, and will meet levels of 0.15 lb/ MMBTU ( NO x SIP call) to 0.125 ( IAQR/ CAIR) at costs estimated by EPA to be less than $ 2,000/ ton. The commenter said that SCR represents the best available technology for removal of NO x. Commenter 0232 said a greater control efficiency is possible for these sources.

Commenter 0267 said the NO x level should be lowered to require application of postcombustion controls. At a minimum, application of post combustion controls for NO x should not be ruled out as BART. Commenter 0280 agreed and said the presumptive NO x level of 0.2 lbs/ MMBTU should be considered as the maximum, not minimum, allowable emission. States should require the lowest emission rate that can be achieved using all available and applicable control technologies as in BACT. The economic feasibility should be the limiting criteria.

Comment: Six commenters provided other comments on controls ( 0221, 0241, 0244, 0252, 0255, 0256). 184 Commenter 0241 said if EPA intends to retain a presumption regarding NOx controls in the final Guidelines, EPA should specify only that EGUs should be equipped with combustion controls to limit NO x emissions without identifying a presumed NO x emission rate. Commenters ( 0244, 0252) agreed that EPA should not set a presumptive level of control, since it should be determined on a case by case basis. However, if a limit must be set as guidance for the states it should be higher than 0.20 lb/ MMBTU, in order to avoid forcing the use of post combustion controls ( e. g. SCR and SNCR.).

Commenter 0256 said if EPA does retain the presumptions, at a minimum, the presumptions should not apply to units that already are controlled with, for SO 2, scrubbers, and, for NO x, combustion controls that were added after enactment of Title IV of the Act. Units with combustion controls that were added after enactment of Title IV should be deemed to already have the best combustion controls available, and thus should not be subject to the presumption. Again, the state should be allowed to analyze BART for those units applying the statutory factors in light of the relatively recent NO x controls that were retrofit at the unit Commenter 0221 said that because power plants account for about one quarter of the nitrogen oxide emissions nationally, and because the Agency also has and will have considerable " experience in evaluating NO x control options for utility boilers," a presumptive control level for NO x should be presumed as " best available" at the outset of the required top down BART analysis for both controlled and uncontrolled power plants. In order to provide support for such a presumption, EPA should undertake a similar analysis of NO x removal technologies as was done by ORD for sulfur dioxide.

Commenter 0255 provided data on 100 coal fired units and the majority are very high performing. The incentive to control emissions under the NO x SIP Call will become stronger over time, assuming electric demand continues to grow, as sources utilize their banked emissions. As the bank of emission credits is reduced, additional NO x reductions will be required. Some sources will be required to install control technologies while those with controls will have an incentive to operate their control technologies at their highest efficiency so they can sell the emission credits that they offset.

Comment: Four commenters discussed the averaging period for the emission limits ( 0207, 0214, 0238, 0314). Commenters said the averaging period is unclear and should be annual vs. a short term limit ( 0207, 0214, 0238). Commenter 0314 suggested a 30 day rolling average.

Comment: Eight commenters made general comments on the proposed NO x levels ( 0181, 0186, 0215, 0225, 0241, 0268, 0275, 0314). Commenter 0181 said EPA should remove the presumptive NO x control levels from the final BART guidelines and instead replace it with a site specific cost analysis. Once again, the presumptive NO x emission control approach inappropriately ignores the need for a visibility impact evaluation which is required in Step 5 of the proposed case by case 185 BART engineering analysis. Commenter 0268 such a presumptive limit infringes on a state's authority to establish BART on a case by case basis considering not only visibility improvement, but other factors as well.

Commenter 0186 said EPA's proposal for no post combustion NO x controls on power plants should apply equally across all source categories; otherwise, there should be no presumptive control technology prohibition for any source category.

Commenter 0215 said if an EGU is achieving the default/ presumption for NO x, it should not be required to do a BART determination for that pollutant. Such presumptions would streamline the BART process for those sources willing to reach these control levels.

Commenter 0225 said for sources located within 50 km of a Class I area, the source could be required to perform an evaluation of control technologies that compare their cost effectiveness. A number of the large power companies have completed these types of evaluations and have a good understanding of the cost of the various control scenarios for their units. States may want to request cost effectiveness evaluations from sources to determine if a source can cost effectively reduce their emissions. Because a larger number of sources outside of the NO x SIP Call region have not been required to install many advanced NO x controls, cost effective reductions can be achieved.

Commenter 0241 said, for the same reasons identified above with respect to the presumptive SO 2 control level for EGUs, the commenter objects to EPA' s proposal to establish a presumptive NO x control level for EGUs.

Commenter 0275 supported EPA's proposed finding that add on NO x controls would be too costly to be considered BART for EGUs, in most cases. Even more so, this would hold true for non EGU boilers, " smaller boilers are generally less cost effective to control." However, this finding cannot be made unless a demonstration is made that visibility impairments do not remain. That is, NO x add on controls for EGUs and non EGUs may be appropriate if modeling indicates that 2018 visibility goals will otherwise not be met.

Commenter 0314 expects continuing technological improvement in the future and that a specific presumptive BART level set by rule, will make it difficult for a state to establish a lower level. As proposed for SO 2, the commenter suggested a range for NO x that will account for the variability in the boilers as well as technology improvements in the future. A range of 0.13 to 0.17 lb/ MMBTU was suggested.

<IP_ADDRESS> General Comments Regarding Presumptive Limits Comment: Seven commenters supported the use of presumptive emission limits in the BART program ( 0179, 0221, 0255, 0285, 0299, 0323, 28 266). Commenters said the limits are achievable ( 0179, 186 0255) and are one of the most essential components of the BART guidelines because they establish a starting point representing the " best available technology" in the required engineering analysis ( 0221). Some commenters requested that EPA establish more stringent limits and harmonize the presumptive BART emission limits for EGUs under the regional haze program with the BART guidelines ( 0221). Commenter 0323 approved including a specific BART determination for large, bituminous coalfired electric generating stations. These facilities constitute the largest emitters of sulfur dioxide and nitrogen oxides among all 26 source categories subject to BART.

Commenters ( 0285, 28 266) urged EPA to develop national guidelines and presumptive BART requirements for source types common to several states to make the process more efficient and workable for the states. Commenters ( 0299, 28 266) added that the guidelines should encourage consistency between states and said EPA should establish a consistent set of protocols upon which a BART analysis for each source category should be based. Commenter 0299 added that such protocols should not eliminate the flexibility each state may need to address unusual circumstances at individual sources, but these protocols could potentially eliminate the need for case by case review for many sources. In the absence of a presumptive standard, the proposed BART guidelines must contain explicit criteria for determining BART. In addition, the BART Guidelines should include defined criteria for " engineering", " useful life", and " cost".

Comment: XX commenters said EPA should establish presumptive limits for other pollutants and/ or source categories ( 28 248, 28 255, 28 358). Commenter 28 255 would also seek to establish limits for source categories in addition to utility boilers to make the process more uniform and consistent across the country and easier for the states. Commenter 28 358 said the SO 2 limits should be expanded for all BART eligible industrial boilers in all 26 categories and set at 95% to reflect control technology performance. Commenter 28 248 proposed setting a limit for particulate matter at 90%.

Comment: Forty nine commenters opposed establishing presumptive emission limits ( 0171, 0181, 0184, 0195, 0197, 0198, 0208, 0210, 0211, 0214, 0215, 0217, 0224, 0226, 0228, 0238, 0244, 0246, 0247, 0252, 0253, 0254, 0256, 0268, 0270, 0275, 0276, 0308, 0314, 0321, 28 243, 28 264, 28 267, 28 305, 28 333, 28 340, 28 342, 28 347, 28 354, 28 356, 28 357, 28 360, 28 385, 28 390, 28 401, 28 402, 28 748, 28 7003, 28 7009).

Commenters said this approach restricts the flexibility of the states and/ or sources to make the control technology evaluations on a case by case basis ( 0171, 1081, 0195, 0197, 0211, 0217, 0247, 0253, 0256, 0268, 0275, 0276, 0321, 28 243, 28 305, 28 333, 28 340, 28 342, 28 349, 28 354, 28 357, 28 360, 28 385, 28 390, 28 748) without resulting in a notable degree of improvement to visibility ( 0171, 0197). 187 The Act requires states to use the statutory factors in making case by case BART determinations ( 0195, 0197, 0210, 0211, 0217, 0228, 0238, 0244, 0246, 0247, 0252, 0253, 0256, 0268. 0308, 0314, 0321, 28 264, 28 267, 28 347, 28 355, 28 357, 28 359, 28 360, 28 385, 28 390, 28 401, 28 402, 28 747, 28 748, 28 7001, 28 7003, 28 7009). Commenters ( 0211, 0217, 0246) added that, rather than assist states by providing them with resources, tools and guidance under BART guidelines, EPA's use of rebuttable presumptions will tend to require significant levels of state resources for states to exercise discretion in their BART determination processes. Most states have limited administrative resources to address these issues and therefore, EPA's use of presumptive requirements will discourage state level discretion  opposite the intent conveyed by the Coin Growers decision.

Commenters ( 0198, 0226, 0254) said the presumptive levels are not achievable across the range of boiler types, vintage of existing controls and coal composition. Commenter 0198 preferred the use of trading under CAIR to meet BART requirements in the most efficient and cost effective manner. Commenter 0226 said if a presumptive level of control/ emission rate is retained in the final rule, the guidelines should, at a minimum, make it clear that states have the authority to select an alternative level of control/ emission rate, without an undue evidentiary burden, given appropriate consideration of all the statutory BART factors. Commenter 0253 asked that EPA either delete the provisions for mandatory default control levels or provide a source with the option of using the default control levels, rather than making them mandatory. Commenter 0276 said if EPA establishes presumptive control levels for EGUs, average annual values are more appropriate than those in the proposed regulations. In addition, BART should not be structured in a way that results in rigid technology based limits that interfere with established NO x and SO 2 emission trading programs. Commenter 0314 said if EPA needs to define a target, it should use a range to prevent diminishing states' flexibility in case by case BART reviews.

Commenters ( 0214, 0215, 0238, 0254) said EPA fails to make clear how the proposed default values for SO 2 and NO x relate to visibility impairment. Visibility is both Class I area and source specific, which is the reason Congress gave the states the lead role and discretion in the BART program to determine which sources need to install or upgrade controls. Through the use of presumptions and default values, however, EPA's prescriptive process, as proposed, would make the installation of maximum controls more likely without regard to visibility benefits. Instead, as required by statute and rules, EPA should give the states maximum flexibility to use the five statutory factors in their BART determinations. Commenters ( 0228, 0247) said sources must be allowed to assess the visibility improvements of a variety of control options. Commenter 0308 said states should be allowed to exempt BART eligible sources from BART requirements if these sources do not impact or have very little impact on visibility in a Class I area.

Commenter 28 342 said even if a presumption were appropriate under the visibility protection program ( and it is not), EPA cannot adopt one now because the Agency has not satisfied the conditions for creating a presumption. Federal presumptions can be promulgated only when the Agency has established ( based on generic application of law to fact) that the presumption 188 is valid.

Commenters ( 0208, 0270) said EPA's default and presumptive control levels for SO 2 and NO x are inconsistent with the BART control efficiencies proposed by the WRAP and should be removed from the proposed guidelines. In no event, however, should BART force plants in the West to reduce emissions to levels greater achievable using dry scrubbing technology for SO 2 and advanced low NO x combustion technology for NO x. As EPA has pointed out in its discussion of Clear Skies and CAIR, wet scrubbers and SCR are inappropriate for the arid West. In fact, the statute itself makes the NSPS a ceiling for BART. Commenter 0270 said the proposed presumptive BART emission limitations are inconsistent with the Regional Haze Rule for the GCVTC states ( WRAP Annex and SIPs under 40 CFR 51.309), the Administration's proposed legislation for the power generation sector, the CSA, and the proposed IAQR.

Commenters ( 0184) said limits should not be set for those pollutants for which a facility has no known control.

Commenter 0246 said EPA should clarify that greater reasonable progress need not be demonstrated by achieving emission reductions greater than those that would occur by applying the presumptive control levels proposed by EPA to all BART eligible sources. Such an approach would undermine the fundamental role of the states in determining BART or what constitutes greater reasonable progress than BART. The WRAP, states, tribes and stakeholders conducted a thorough analysis and balancing of the BART factors to arrive at the WRAP milestones   all of this was conducted without imposing presumptive control levels during the analysis and discussion.

If EPA does utilize the presumptive emission limits, commenter 0197 said , if a source agrees to 95% control or the range of 0.1 0.15 lb/ MMBTU for SO 2, they should be automatically exempt from the BART process. The same goes for the 0.2 lb/ MMBtu for NO x.

Comment: Commenter 0268 questioned the legal authority of EPA to impose presumptive limits for sources between 250 MW and 750 MW in size because the visibility provisions of the Act only specify evaluation by the states of units with a capacity in excess of 750 MW. Commenter 0184 said the statute requires state to take a case by case approach for non EGU sources. Discussion of such emission limits should be explicitly limited to those large EGU facilities for which EPA has the statutory authority to define BART and to set such limits. Commenter 0237 said the presumptive BART level for utility boilers would impose hardship on industrial sources because there are many practical differences in the way industrial boilers and electrical generating units are operated, including short term swings in demand, that make such BART controls unreasonable. Therefore, EPA must underscore in its final guideline that these control levels are not presumptive BART for industrial boilers.

Five commenters said EPA should consider the type of emission unit ( e. g., coal type, boiler type, and/ or emission controls) when making BART determinations ( 0195, 0198, 0214, 0238). 189 Commenters ( 0214, 0238) added that states and sources should be focusing on the incremental costs and benefits from the installation of additional controls or the upgrading of existing controls in the BART determination.

Comment: Two commenters supported the use of optional presumptive limits as a choice for source owners/ operators to avoid a BART analysis ( 0210, 0256). This approach would limit the resources expended for many determinations, but would allow states to consider all of the statutory factors where appropriate.

Comment: Six commenters said EPA needed to address the averaging period associated with the presumptive limits ( 0195, 0227, 0228, 0268, 0306, 0323). Some commenters suggested annual average limits ( 0195, 0268) while others said they should be no less than a 30 day or monthly average ( 0228). Other commenters asked EPA to specify an averaging time similar to the averaging time of visibility impact assessments, e. g., 24 hour average ( 0227, 0306).

Commenter 28 385 said EPA indicates that BART determinations should specify an averaging time " consistent with established reference methods." EPA is again skewing BART determinations to a " top down" BACT assessment, which is not consistent with the statute. Short averaging times would significantly impact cost by requiring controls with redundant systems, but would provide only minimal additional annual tons reduction and negligible visibility benefits.

Comment: One commenter said EPA should establish emission limits for PM because of the magnitude of emissions and the availability of proven controls ( 0255).

Comment: Seven commenters made other general comments regarding presumptive emission limits ( 0195, 0214, 0232, 0238, 0255, 0299, 0306).

Commenters ( 0195, 0214, 0238) said exceptions should be made for startups, shutdowns and malfunctions of control equipment.

Commenters ( 0214, 0238) said EPA should make it clear that if any source is willing to achieve 95% control or somewhere along the scale of 0.1 to 0.15 lb/ MMBTU, it should automatically be exempt from the requirement to perform a BART analysis for SO 2. The same should also be true regarding a BART NO x analysis for sources willing to achieve the 0.2 lb/ MMBTU NO x x presumption for EGUs. Such presumptions would streamline the BART process for those sources willing to reach these control levels. Commenter 0255 said EPA should set a high threshold for sources to justify being exempted because the current suite of best available technologies can readily meet and go beyond the mandated limits. EPA should encourage the states to consider these factors as well. 190 Commenter 0232 said there should be a provision to revisit appropriate BART control levels at a date certain. While it is appropriate to provide clarity and certainty to industry for the installation of retrofit controls, it is also important to provide for application of new controls with increased control efficiency due to technology improvements in order to meet the express requirements of the Act to prevent any future and remedy any current impairment of visibility in Class I areas.

Commenter 0255 noted that EPA did not address emission of SO 3 from power plants. This has become an increase area of concern for power companies as states have set emission standards for SO 3 in the operating permits for power plants. A number of control technologies have been developed to address this pollutant and are able to achieve a high level of removal.

Commenter 0299 said the BART presumptive level of control proposed for EGUs boilers for SO 2 emissions and for NO x emissions should be made consistent with other clean air programs. Specifically, the presumptive level of controls for EGU boilers should be consistent with the requirements adopted in the CAIR, and consistent with the requirements contained in the federal NO x SIP Call.

Commenter 0306 said BART should be no more stringent than a current BACT assessment for an existing facility. EPA should define presumptive BART in a manner consistent with recent NSR enforcement actions. Presumptive BART should not be more stringent than requirements in recent agreements ( or proposed agreements) that settled NSR violations.

4.3 General Comments Regarding BART Determination 4.3.1 Comments Regarding Streamlining the BART Determination Process Comment: Four commenters made suggestions to streamline the BART determination process ( 0189, 0285, 0302, 0304). Commenter 0189 said EPA should allow an individual state   or a group of states in a region   to adopt a generic approach to at least some BART issues in the interest of consistency and efficiency, while reserving some others for case by case " balancing". It would also be efficient for EPA itself to first accept, and then facilitate, such use of streamlined state procedures for making BART decisions. To the extent EPA believes states making BART decisions should consider certain factors, EPA could encourage States to consider these factors, and make that consideration more efficient, by issuing " guidance" stating its view of those issues for the states to consider. EPA's failure to even consider these clearly superior alternative approaches is emblematic of its lack of attention both to the freedom of action that the Act clearly grants to states making BART decisions, and to the paperwork burdens that its preferred approach would impose on states. Other commenters requested guidance, such as control technology guidelines, to provide a starting point for the BART analysis ( 0285, 0304). 191 Commenter 0302 stated a preference for the " alternative approach to control engineering analysis under the BART" because of limits on state resources to perform site specific engineering analyses. Commenter 0304 said the BART approach should mirror BACT where possible. The BACT approach has served the PSD program well. It is well understood by both agency staff and industry.

Response:

We believe we have provided as streamlined a process as possible, given the directives in the CAA. As explained in the preamble, we intend to propose revised alternative provisions to allow for emissions trading programs in response to recent litigation. In regard to the BACT process, we have structured the BART review similarly to BACT reviews in many ways, in order to be consistent with process with which States are familiar.

4.3.2 Comments Regarding Reasonable Progress Comment: Five commenters addressed reasonable progress issues. Commenter 0246 interprets " greater reasonable progress" as encouraging consideration of all the BART factors including visibility, as well as the comparative levels of emissions reductions. Whether done on a sourcespecific or category wide basis, states have the responsibility to consider all of the factors and the latitude to do so in a manner they deem appropriate. This is similar to the approach contained in the WRAP Annex.

Commenters ( 0249, 0251) noted that the rules lack criteria for measuring reasonable progress, nor do they provide an objective basis for determining whether a state's plan assures reasonable progress.

Commenter 0251 provided extensive comments on this issue. The commenter concluded that the absence of criteria for determining whether progress is " reasonable" also renders the haze rules inadequate to meet the statutory mandate to " assure" reasonable progress. Also, EPA's failure to define " reasonable" progress also violates the basic prohibition under administrative law against arbitrary and capricious administrative action.

Response:

We note that this rulemaking is not intended to address criteria for reasonable progress, but only to implement the BART provisions of CAA section 169A.

4.3.3 Other General Comments Regarding the BART Determination Comment: 192 Two commenters stressed the need for states to consider the statutory factors including visibility benefits, energy impacts, or the remaining life of control equipment ( 0189, 0275). Commenter 0275 added that the proposal also fails to specify how states would address the visibility analysis results. One commenter ( 0232) said the guidelines fail to clearly define what cost would be considered unreasonable, what energy impact would be considered unacceptable or what threshold environmental impact would result in the elimination of a particular technology option. For the sake of a nationally consistent program, additional specificity is warranted in the guidelines as to what levels would prevent the most stringent controls from being considered. Two commenters said nowhere in the Act is there any presumption that some technology is BACT simply because it has been determined to be BACT for a given type of emission source in another location ( 28 364, 28 395). Congress recognized that the balancing test is mandatory simply because site specific considerations will warrant emphasis on different considerations.

Response:

The BART guidelines is intended to aid States in assessing the BART factors. States have considerable latitude in weighing the BART factors and taking specific circumstances into account.

Comment: One commenter ( 0207) asked EPA to clarify in the final rule that projects undertaken to comply with the regional haze rule are the types of projects excluded from NSR regulatory schemes by the Pollution Control Project provisions. Commenter 28 255 said if NSR regulations are amended to change the definition of baseline period, it should be done as soon as possible so it won't disrupt the BART process. Commenter 0184 said the final rule should exempt BART compliance from triggering NSR/ PSD There are several examples in the proposal that indicate that a physical modification or change in the method of operation could be necessary to meet the BART requirements. The commenter added that EPA should make an effort to find regional haze solutions that are aimed at addressing the most significant contributing sources, rather than targeting only major stationary sources. A more sensible approach would be to examine all sources and the associated cost effectiveness of controls and then make more holistic determinations as to which sources should be addressed. While this issue is beyond the scope of the BART rule   or even the underlying regional haze rule   EPA should use the issue of regional haze to develop policies that seek reductions from the most significant sources of a given emission in the most cost effective manner. This might require creative technologies and decision making, as well as politically tough approaches, but it is necessary to truly address most of the remaining air quality issues. Commenter 28 273 said the final rule should explicitly exempt BART compliance from triggering NSR/ PSD.

Response:

These comments are outside the scope of the BART rulemaking. 16 Consolidated Appropriations Act for Fiscal Year 2004. Pub. L. 108 199, January 23, 2004.

193 5.0 Enforceable Limits/ Compliance Date 5.1 Proposed Elimination of " Committal" SIP Deadlines Comment: Two commenters agreed with the proposal to eliminate the requirement for the commttal SIP ( 0231, 0259). One commenter ( 0245) was concerned about the level of resources required by the BART guidelines combined with the CAIR, PM2.5 and 8 hour ozone rules impairing the states' ability to complete the regional haze SIP by 2008.

One commenter ( 0251) noted that the Transportation Equity Act ( TEA 21) set explicit deadlines for submittal of haze SIPs by the states. The commenter discounted EPA's " speculation" about Congressional intent, and said that the fact that Congress allowed an exception for the Grand Canyon regional planning process is a strong indication that it did not intend to do so for other regional efforts. The nature of visibility impairment in a given region and the measures needed to address it do not change depending on whether an area is designated " attainment" or " nonattainment" in the Code of Federal Regulations. There is no reason that states cannot begin working together well before the haze SIP submittal deadline to address these issues and develop coordinated strategies. EPA's illegal extension of the deadline simply encourages states to needlessly delay that process. Two commenters ( 28 266, 28 278) said EPA should restate the SIP timelines in the guidance. Commenter 28 278 added that it would facilitate multi pollutant strategy development, by addressing the coordination of the SIP timelines for regional haze, fine particles and 8 hour ozone.

Response:

As explained in the 2004 reproposal, Congress has now reset the deadlines for regional haze SIP submittals. 16 SIPs will be due 3 years from promulgation of PM2.5 designations. Therefore SIPs will be due December 17, 2007.

5.2 Proposed Harmonization of Deadlines for Section 308 and 309 SIPs Comment: Commenters discussed the proposed harmonization of deadlines for section 308 and 309 SIPs. Some commenters supported the revised changes to the due dates for submitting SIPs and SIP revisions under section 308 and 309 ( 0231, 0259, 0293). 194 Commenters ( 0231, 0259, 0306, 28 389) urged EPA to finalize the BART guidelines as soon as possible to allow states with an extended regulatory time frame to complete the technical analysis and SIP development process in time to meet the SIP submittal deadline. Additional delay will only further complicate state work efforts as assumptions will have to be made in order to move forward toward SIP completion absent final decisions on the BART guidelines. Commenter 28 389 said that some of the operational details of the backstop trading program established in the Annex of the GCVTC are tied to existing BART guidelines and the Regional Haze rule. We believe that the approach taken in the Annex is consistent with the proposed BART rule and the Guidelines.

Commenter 0169 said in implementing the SIP requirements for BART, consideration should be given to facilities which have recently implemented regulations such as MACT or NSPS which also reduce SO x, NO x, VOC, and PM2.5. If a facility has just made significant capital investments in new technologies or state of the art emission controls which also reduce regional haze, they should be given credit for such actions and any new SIP requirements should be harmonized with respect to additional controls and compliance dates.

Commenter 0217 noted that several WEST Associates members operate in the five states ( Arizona, New Mexico, Oregon, Utah and Wyoming) that have selected a Section 309 course of action under the regional haze program. Those states have submitted SIP proposals on or before December 31, 2003. EPA should acknowledge that nothing in the re proposed regional haze rule provisions or the BART guidelines would necessitate changes to the essential program elements upon which those SIP submittals relied ( e. g., the quantitative emission milestones for SO 2). Commenter 0259 urged EPA to ensure that the revised rule and guidelines will have no impact on the five state implementation plans already submitted under section 309 of the Regional Haze Rule.

Response:

See the discussion of CEED v. EPA in the preamble to this rulemaking.

Comment: Commenter 28 255 said the year 2002 should be established as the base year for 308 states' emission inventories for consistency between RPOs and states.

Response:

The comment is outside the scope of the BART rulemaking.

5.3 Compliance Deadlines Comment: Three commenters said the proposed compliance date set at 5 years after EPA approves the SIP is highly uncertain given the unknown amount of time for EPA rulemaking ( 28 266, 28 278, 17 70 FR 9705, February 28, 2005.

195 28 312). The commenters asked EPA to provide guidance to states on the estimated times for review of the SIP submittals.

One commenter ( 28 303) said the compliance deadline of 2018 allows ample time for both program development and compliance.

Response:

The 5 year compliance deadline was set by Congress in CAA section 169A.

5.4 Monitoring Comment: Commenter 0207 said, with respect to emission monitoring, EPA appears to recognize that BART itself should not necessarily include a particular monitoring requirement. For example, EPA states in the re proposed guidelines that a requirement that BART emission limits be met on a continuous basis " does not necessarily require the use of continuous emissions monitoring ( CEMs)." While most if not all BART eligible EGUs already employ " Part 75" CEMs, non EGU sources may not. The commenter is aware that various periodic monitoring methods are sufficient to ensure compliance on a continuous basis. Expending resources on installation and operation of new continuous emission monitoring equipment does not have an impact on visibility, as long as other appropriate methods are available to demonstrate compliance. Moreover, certain pollutants, such as VOCs, do not readily lend themselves to a continuous monitoring scheme.

Response:

States will need to set specific monitoring requirements for BART sources. Section 302( k) of the CAA requires emissions limits such as BART to be met on a continuous basis, and the guidelines discusses specific issues related to this requirement. In order to provide consistency across programs, as part of the presumptive limits for large EGUs we have added a clarifying provision recommending an averaging time of a 30 day rolling average. We have also included a recommended definition of " boiler operating day" that is consistent with the definition in the proposed revisions to the NSPS for utility boilers in 40 CFR Part 60, subpart Da. 17 This would allow 30 day rolling average emission rates to be calculated consistently across sources.

5.5 Enforceable Limits Comment: 196 Three commenters noted that the proposed guideline also suggests that an enforceable limit should be established for each pollutant subject to control ( 28 266, 28 278, 28 312). Does this mean that states must establish ammonia limits for boilers, as well as SO 2, NO x, VOC and PM?

Response:

As noted above and in the preamble, States have considerable discretion in regard to ammonia.

6.0 Statutory and Executive Order Reviews 6.1.1 Administrative Process Comment: One commenter ( 0276) said EPA is pursuing an inappropriate administrative process in this regulatory development that will result in litigation. Affected parties are not being provided an opportunity to comment on the specific regulatory language that might drive significant financial investments in capital equipment. For example, individual source exemptions might be subject to " Look up Tables" or " Source Rankings" or the " Q/ D Method." However, these tables, rankings, etc. have not been provided and cannot be evaluated. Further, there may or may not be a trading program. This proposal should be designated an advance notice of proposed rule making and provide another chance to comment on something more than a menu of possible approaches.

Commenter 28 391 said the proposed guidance is contrary to the EPA's earlier efforts to reduce the complexity and costs of part 70 applications and permits, and conflicts with provisions for treatment of insignificant emission units and activities in the major source operating permit regulations. Issuance of the BART guidelines, as proposed, will negate the previous progress made to remove regulatory barriers, minimize administrative costs, and would ultimately require BART eligible sources and permitting authorities to expend the very resources previously determined to be unnecessary because of the trivial environmental benefits to be realized.

Commenter 28 294 said EPA should extend the public hearing schedule to include evening hours to encourage public participation.

Response:

We believe that at this point, ample opportunity for public comment has been provided on all the provisions of the final BART Guidelines, including public hearings in different locations. In addition, the BART Guidelines implement specific provisions of the CAA, and the final Guidelines incorporates a number of new provisions aimed at streamlining BART determinations, particularly with regard to flexibility in conducting determinations for VOC and ammonia sources.

6.1.2 Executive Order 12866  Regulatory Impact Analysis 197 Comment: Thirty one commenters said the regulatory impact analysis is flawed and should be redone ( 28 243, 28 278, 28 304, 28 305, 28 312, 28 333, 28 336, 28 337, 28 340, 28 341, 28 342, 28 344, 28 345, 28 347, 28 348, 28 349, 28 355, 28 356, 28 357, 28 358, 28 361, 28 364, 28 387, 28 395, 28 398, 28 405, 28 406, 28 747, 28 748, 28 778, 28 7013) for several reasons:

° BART controls will produce undue economic hardship to the largest industrial customers and the communities they support ( 28 243) ° Analysis should address estimated emission reduction amounts, changes in visibility levels, and costs associated with BART controls ( 28 278, 28 312, 28 342) ° The costs of the program, including control costs and compliance costs, are vastly understated ( 28 304, 28 333, 28 336, 28 348, 28 355, 28 356, 28 357, 28 358, 28 364, 28 387, 28 398, 28 405, 28 406, 28 747,28 748) and several commenters provided examples ° The accuracy of EPA's renewed economic cost projection is questionable, given that EPA's proposed BART rule appears to greatly limit the " flexibility" the states were provided by Congress in 1977 for performing BART cost benefit analysis ( 28 337) ° Analysis ignores impacts of delays in implementation of NAAQS implementation ( particularly PM2.5 standards) on compliance cost assumptions ( 28 341, 28 342, 28 344, 28 345, 28 347, 28 348, 28 358, 28 387, 28 398, 28 405, 28 778). In addition, most of the utility plants in the western states are not located in areas expected to be designated non attainment for PM2.5 or ozone ( 28 357) ° A new RIA is needed to address the goal of " natural conditions" ( 28 342) ° Neither the proposed guidelines nor the RIA specifically addresses the amount of compliance costs that will be imposed on sources in the 25 source categories other than electric utilities in the " fossil fuel boilers" category. It is arbitrary to ignore the substantial costs that would be imposed on other types of industrial sources under the EPA's proposed emissions unit by emissions unit approach ( 28 345, 28 349, 28 364, 28 748) ° Because BART is a technology driven regulation, EPA should presume for its economic impact assessment that all BART eligible sources would be required to install flue gas desulfurization ( for coal and oil combustion sources) to control SO 2, Selective Catalytic Reduction to control NOx, ultra efficient ESPs or baghouses to control PM, along with appropriate controls for VOCs and ammonia ( for sources using ammonia for NO x control) ( 28 348) ° Neither the RIA nor the guidelines attempts to determine how many sources will be found subject to BART because of the expansive BART eligibility scheme set forth for the first time in the guidelines ( 28 349) ° The RIA reduces the total costs by 67% to take account of the trading program ( similar to the Title IV program). However, the BART trading program is complex, and it is unlikely states will use it ( 28 349, 28 748) ° There is no basis for concluding that only 35 utility units will be required to install additional controls to meet BART. That conclusion is completely at odds with conclusions set forth in a report on BART by NESCAUM ( A Basis for Control of BART Eligible 198 Sources), which states at least 365 units will be required to set BART in 29 eastern and midwestern states ( 28 349) ° By seeking to apply stringent presumptive controls on these de minimis sources of visibility impairing pollutants ( i. e. emergency generators), the proposed guidelines would impose significant control costs without discernible environmental benefits ( 28 355) ° EPA determined that because the guidelines clarify, and do not change, existing requirements of the regional haze rule, they have no effect on the RIA prepared for the regional haze rule. However, to the extent that the " clarification" set forth in the guidelines establishes the scope of the costly and perhaps lengthy engineering analysis and public participation process to determine BART for numerous facilities, the regulatory impact on implementing states can be significant. Now that the proposed guidelines spell out more clearly EPA's position on the details of a BART analysis, a new RIA is warranted ( 28 361) ° EPA continues to rely upon its out of date RIA  a document prepared under very different economic and energy related circumstances. For example, the RIA has a more than fivefold error with respect to natural gas costs. Without better substantiation and more accurate and up to date information, EPA's outdated economic impact projections cause significant concern as to whether the EPA conclusion of " no adverse effect" complies with the analysis required by the President's Executive Order ( 28 264, 28 395) ° EPA should use current year dollars for estimating impacts rather than 1990 dollars ( 28 387) ° The BART guidance purports to require the most stringent control technology not just for SO 2, but for all five visibility impairing pollutants as well, each of which requires distinct and separate controls. While $ 72 million may be a reasonable total compliance cost for a properly designed BART program, it is orders of magnitude less than what EPA's proposal would cost ( 28 747) ° The RIA should consider the costs of other regulatory requirements only if the sources which have implemented controls for those requirements are provided credit for the associated emission reductions relative to a BART analysis for regional haze. Consistent with a " bottom up" analysis, only incremental reductions and costs should be considered. This could lead to the determination that the current controls actually satisfy BART ( 28 7013.

Response:

As part of the regulatory package for the final BART rule, EPA has prepared a revised Regulatory Impacts Analysis ( RIA). This analysis has broadened the scope of the assessment, taking into account similar issues as raised by the commenters. However, as explained in the proposal materials, since BART is guidance to the States, this EPA assessment is illustrative of the costs and benefits expected to the nation as a result of this final rulemaking. The details of the assessment are found in the RIA. In addition, we do not agree that the BART rule limits the flexibility States were given in the CAA for performing cost benefit analysis. The CAA clearly lays out the criteria for BART 199 determinations, including costs and visibility improvement, and the BART guidelines provide much flexibility. See the preamble for detailed discussion.

6.1.3 Regulatory Flexibility ( SBREFA)

Comment: Five commenters said EPA had not fulled its obligations regarding small entities ( 28 251, 28 342, 28 345, 28 349, 28 364). Commenters said there will be substantial impacts on small businesses, in the aggregates industry for example ( 28 251). Commenter 28 342 said EPA must make a showing that the " large industrial plants" that are subject to BART are in fact not owned by small entities. Commenters ( 28 345, 28 349, 28 364) agreed that many small businesses might easily be major sources subject to the rule, especially due to the expansive BART eligibility scheme.

Commenters ( 28 345, 28 364) noted that EPA concludes that its proposal would impose requirements on states, not sources, and therefore presents no special small business issues to assess and include in its RIA. The commenter disagreed with this reading of the SBREFA because it exempts EPA from SBREFA for many of its most costly and significant rules, since so many of the agency's regulatory programs operate by imposing requirements on the states that inevitably lead to controls on small businesses. Clearly, a substantial number of small entities will be paying higher electricity bills as a result of the impacts of BART pursuant to these guidelines. Commenter 28 242 said the guidelines do not defer to state discretion as EPA claims ( 28 342).

Response:

The BART rule and guidelines would not establish requirements applicable to small entities. The rule would apply to States, not to small entities. The BART requirements in the regional haze rule require BART determinations for a select list of major stationary sources defined by section 169A( g)( 7) of the CAA. However, as noted in the proposed and final regional haze rules, the State's determination of BART for regional haze involves some State discretion in considering a number of factors set forth in section 169A( g)( 2), including the costs of compliance. Further, the final regional haze rule allows States to adopt alternative measures in lieu of requiring the installation and operation of BART at these major stationary sources. As a result, the potential consequences of the BART provisions of the regional haze rule ( as clarified in today's rule) at specific sources are speculative. Any requirements for BART will be established by State rulemakings. The States would accordingly exercise substantial intervening discretion in implementing the BART requirements of the regional haze rule and today's guidelines. Nonetheless, the EPA has undertaken an illustrative analysis to assess the potential small business impacts of BART based upon EPA's assessment of the actions States may take to comply with the BART rule and guidelines. This assessment is in the final Regulatory Impact Analysis ( RIA) that accompanies the final rule.

6.1.4 Paperwork Reduction Act 200 Comment: Two commenters said a new and complete analysis of the paperwork burden is needed ( 28 244, 28 342). Commenter 28 342 said EPA seems to dismiss its need to comply with this Act because the information collection requirements clarify, but do not modify, the information collection requirements for BART. In fact, the proposed BART guidelines do add to the requirements of the regional haze rule so EPA should comply with the Paperwork Reduction Act. Commenter 28 244 said nothing in the original visibility rule could be read to require a " top down" approach under which a state would have to analyze all more stringent technologies in exhaustive detail in order to justify its choice of a technology of moderate expense, to evaluate all control alternatives using six separate charts, to require states to survey fourteen different databases listed by EPA to determine which technologies were " available," etc.

Response:

EPA has reviewed its conclusion as requested by the commenters. Based on that review, EPA is retaining it's conclusions that BART clarifies, but does not modify the information collection requirements for BART. Therefore, this action does not impose any new information collection burden. However, the OMB has previously approved the information collection requirements contained in the existing regulations [ 40 CFR Part 51] under the provisions of the Paperwork Reduction Act, 44 U. S. C. 3501 et seq. and has assigned OMB control number 2060 0421, EPA ICR number 1813.04.

6.1.5 Unfunded Mandates Reform Act Comment: Two commenters said the provisions of the UMRA do apply to the proposal ( 28 244, 28 342) because of the extraordinary analytical burdens of the proposal, and its bias toward tight controls ( 28 244). Commenter 28 342 said EPA should comply with the UMRA because the regional haze rule and the proposed BART guidelines place what is tantamount to a direct regulatory burden on States to conduct massive regulatory analyses and on governmental owners of fossil fueled electric generating units to install 90 to 95% scrubbers to reduce their SO 2 emissions. EPA's arguments that it has complied with the UMRA are unpersuasive.

Response:

The EPA is not reaching a final conclusion as to the applicability of UMRA to today's rulemaking action. The reasons for this are discussed in the 1999 regional haze rule ( 64 FR 35762) and in the 2001 BART guidelines proposal ( 66 FR 38111 38112). Notwithstanding this, the discussion in chapter 9 of the RIA constitutes the UMRA statement that would be required by UMRA if its statutory provisions applied. Consequently, we continue to believe that it is not necessary to reach a conclusion as to the applicability of the UMRA requirements. 201 6.1.6 Federalism Comment: Three commenters said EPA has not complied with the Federalism requirements ( 28 342, 28 354, 28 364) because EPA has failed to obtain meaningful and timely input from state and local officials. Commenter 28 342 said that in order to be " meaningful," EPA's consultation with the State and local associations must occur in connection with a proposal that is consistent with the broad authority vested in the States to implement the visibility protection program. Commenter 28 354 said EPA's proposed BART guidelines impermissibly limit State authority and unlawfully exceed the Agency's authority. In addition, commenters ( 28 354, 28 364) said, the guidelines violate the " division of governmental responsibilities between the national government and the States" as set forth in the visibility provisions of the Act and clearly have " substantial direct effects on the States, on the relationship between the national government and the States, [ and] on the distribution of power and responsibilities among the various levels of government." Commenter 28 342 agreed that, contrary to EPA's assertions, the guidelines do impose a significant analytical burden on the states and compliance burdens on government owned sources.

Response:

EPA has concluded that today's action, promulgating the BART guidelines, will not have federalism implications, as specified in section 6 of the Executive Order 13132 ( 64 FR 43255, August 10, 1999), because it will not have substantial direct effects on the States, nor substantially alter the relationship or the distribution of power and responsibilities between the States and the Federal government. Nonetheless, we consulted with a wide scope of State and local officials, including the National Governors Association, National League of Cities, National Conference of State Legislatures, U. S. Conference of Mayors, National Association of Counties, Council of State Governments, International City/ County Management Association, and National Association of Towns and Townships, during the course of developing this rule.

6.1.7 Executive Order 13211  Actions Concerning Regulations that Significantly Affect Energy Supply, Distribution or Use Comment: XX commenters said EPA's analysis was inadequate for several reasons ( 28 337, 28 343, 28 345, 28 346, 28 348, 28 354, 28 356, 28 357, 28 361, 28 364, 28 387, 28 395, 28 406, 28 7001):

° It was erroneously based on the impacts of SO 2 controls alone ( 28 337, 28 354, 28 361, 28 364, 28 395, 28 7001) ° The analysis relies on a flawed RIA including assumptions that costs will have already been undertaken for the PM2.5 standard and the energy costs are substantially understated ( 28 346, 28 354, 28 364, 28 387) 202 ° It is unclear whether the analysis took into account the price spikes for energy experienced in late 2000 ( 28 361) ° EPA did not complete the analysis correctly and negative energy impacts may result from implementing BART as required ( 28 7001) ° It ignored the effect on the supply of energy, could result in shut downs and further decreases in supply and should evaluate effects on the reserve margin and the ability of electricity providers to supply enough energy to meet demand ( 28 342, 28 346, 28 354) ° EPA should conduct a more meaningful and thorough analysis of the proposed rule's impact on energy prices, supply, distribution and use before issuing the final rule ( 28 345, 28 364, 28 406). Commenters were concerned that EPA rushed its analysis and that the significant energy impacts to companies are yet to be understood. ° In meeting the requirement of EO 13211, EPA concludes that the " rulemaking is not a significant energy action" and that "[ the BART rules] clarify, and do not change, the existing requirements of the Regional Haze Rule". However, in other parts of the proposed rulemaking, EPA alternatively concludes that the BART rulemaking is a " significant regulatory action", which clearly is the case. ( 28 356) ° The economic rationale that EPA uses to justify the guidelines should be re done so that it more accurately reflects the actual costs that will be borne by western ratepayers as well as better illuminating the potential impacts to the western electricity grid consistent with Executive Order 13211 ( 28 357) ° The environmental impact and the disposal cost of that solid waste should also be addressed in cost calculations as should CO 2 impacts ( 28 406).

Response:

As part of the regulatory package for the final CAVR rule, EPA has prepared a revised Regulatory Impacts Analysis ( RIA). This analysis has broadened the scope of the assessment, taking into account similar issues as raised by the commenters. However, as explained in the proposal materials, since CAVR is guidance to the States, this EPA assessment is illustrative of the costs and benefits expected to the nation as a result of this final rulemaking. The details of the assessment are found in the RIA.

7.0 Miscellaneous Comments 7.1 Process Related Comment: Five comments discussed process related issues ( 0189,. 0208, 0259, 0285, 0302).

Commenter 0189 said the implementing mechanism for BART is the SIP process. Congress' choice of the SIP vehicle, therefore, demonstrates a legislative intent that EPA should get at most one chance to review state judgments of BART applicability, namely when it reviews 203 the SIP for approval or disapproval. Such a reading is also the only one consistent with sound policy. Installation of BART is a one time event that must take place within 5 years of SIP approval under the statutory framework. Congress intended BART as a down payment on the " reasonable progress" target. The proper approach, from the standpoint of both law and policy, would be to address any need for additional controls after the first round of BART as part of the " reasonable progress" obligation.

Response:

The BART process will follow the established process for SIP review. We are not establishing a new process in this rulemaking.

Comment: Commenter 0208 said EPA should encourage voluntary emission reduction projects by specifically exempting such plants from additional BART analysis, specially in instances where controls were voluntarily installed at significantly more stringent levels than that represented by a BART limit. The commenter provided examples where state legislatures have made findings that voluntary measures met BART.

Response:

We have included a provision providing additional flexibility along these lines for sources who adopt the most stringent controls available.

Comment: Commenter 0259 noted that the WRAP is developing an alternative and more efficient approach to the one described in the proposed BART guidelines to address sources in California. Specifically, the WRAP is identifying which types of BART sources ( by category) are located in which air pollution control districts, and then examining the rules and/ or permit levels applicable to those categories to determine if BART is being satisfied . In most if not all cases, this approach should obviate the need to explicitly identify BART eligible sources and to conduct further BART analyses. If, however, a BART category is present in a district whose rules may not satisfy BART for one or more pollutants, then the standard approach in the guidelines would be followed. This approach could also be used in other states when addressing BART eligible source emissions which are well controlled. The commenter urged EPA to ensure that the final guidelines allow states and tribes to use an approach such as the one described above to demonstrate compliance with the BART provisions of the Regional Haze Rule.

Response:

We note that any such approach would still need to meet the requirements of CAA section 169A. 204 Comment: Commenter 0285 asked EPA to prioritize sources for control and consider the " resource vs. environmental benefit" ratio when prioritizing. In particular, EPA should examine how resources should be devoted to sources with fugitive dust, for example, plant roads, storage piles and material handling activities. These sources emit only PM, the emissions levels are generally low, and the fraction of fine PM is small. Priority should be given to the high level emitters of SO 2 and NO X., using air quality modeling or an alternative analysis, which may determine within what distance of a Class I area these smaller sources may significantly affect the visibility and may require that the fugitive dust sources within that distance should be considered for control. EPA also should prioritize for control the emissions units in the general source categories such as the lime plants, portland cement plants, iron and steel mill plants and chemical process plants. These plants have a large number of emission units, many of which are considered insignificant. For example, cement plants contain numerous operations, but it is the kilns that are typically the sole source of PM, SO 2, NO X and VOC emissions and account for a large percentage of the total PM emissions. Therefore, at cement plants, unless they are close to Class I area, the priority for control should be focused on kilns only. Emission units at these plants, identified by source classification codes contained in EPA's Factor Information Retrieval ( FIRE) Data System, should be prioritized for BART control so that the largest ones are the focus.

Response:

This comment is best directed to States implementing the BART provisions.

Comment: Commenter 0302 noted that in the proposed BART guidelines, EPA presents alternative methods for determining which sources would be BART subject sources, which sources should be controlled, and how to assess the impact from individual sources. More in depth criteria and information for options is needed to make a judgment on the best approach.

Response:

As explained earlier, States have flexibility to make these judgements in a variety of ways, so long as they consider the BART factors.

7.2 Definition of Terms Comment: Commenter 0267 said anytime emission limits are discussed in the rule, the averaging period should be specified so that comparisons with other limits are made simpler, and compliance demonstration methods are transparent.

Commenters ( 28 267, 28 272, 28 278, 28 332, 28 349, 28 255, 28 266, 28 273, 28 306) said EPA should define or clarify the following terms 205 ° " substantial fraction" ° " significant contribution" ° " sufficient visibility improvement" ° " region" ° " geographic region" ( what methods should RPOs use to determine the spatial extent of the region, how much flexibility do RPOs have, how boundaries of the geographic regions that " generally extend for hundreds or thousands of miles" would be reasonably limited.) ° " can be emitted and transported" ( is it necessary to show that at least one back trajectory on the 20% worst visibility days from a Class I pass through the county or state in which a given source is located) ° " trivial contribution" ( what is the smallest acceptable geographic area to be " zeroed out," or the amount of difference between the base run and " zero out" run that is considered to be " trivial", is it the same as " significant contribution" or different? Commenter 28 255 supports 0.1 deciview as an appropriate value and only one term should be used to denote " significant" impact) ° " non trivial contribution" ° " contiguous and adjacent properties" in section II( A) ° " emissions unit" ( the range of possible items that EPA has treated as emissions units at a plant site has varied from a single emissions point to a large, integrated collection of equipment consisting of numerous emissions points, moving from the known definition of " major stationary source" to the undefined, yet proposed, " emissions unit" basis will prove confusing for states in the implementation process.) ° " installation" when it refers to " building, structure, facility, or installation"

Response:

Many of these require State specific judgement; others are defined in other EPA programs or explained earlier in this document.

Comment: Commenter 28 306 said the proposed rule encourages states to use the NSR definitions of " potential to emit" and " physical or operational change". These NSR concepts have led to extensive compliance problems, and resulted in serious controversy and deliberations in NSR revisions. As a result of this debate, definitions are likely to be changed in NSR revisions, and would be out of date in BART guidelines perhaps in the near future.

Response:

We have explained above that these are the current operative definitions, which are the only definitions it is reasonable for us to use.

7.3 Role of Federal Land Managers 206 Comment: Sixteen commenters discussed the role of FLMs ( 0147, 0148, 0150, 0159, 0162, 0163, 0164, 0214, 0221, 0227, 0238, 0267, 0284, 0292, 0304, 0318).

Some commenters said that the FLMs should be active participants in the BART process ( 0147, 0148, 0150, 0159, 0164, 0221, 0227, 0267, 0284, 0292, 0304, 0318). Commenters ( 0221, 0227) added that this is consistent with Congress' intent, but was concerned that EPA's proposed rule deprives the FLMs of any meaningful participation in the BART process. Given the almost unlimited exemption authority granted to states under the proposed rule, the consultation with FLMs during the SIP process will occur after the critically important decisions about the scope and rigor of the state's visibility protection program have already been made. This is a reversal in EPA's long standing interpretation of the FLMs' role is without reasoned basis and contrary to law. Commenter 0267 noted that FLMs should retain the ability to review the decisions for all BART eligible source exemptions under any of the approaches. Commenter 0304 said FLMs and states should retain the authority to certify impairment at specific Class I areas which may be " reasonably attributable" to sources subject to the IAQR. This is necessary because some sources will likely have large local impacts, and regional controls may prove to be less effective for some Class I areas.

Two commenters ( 0214, 0238) were concerned that the BART Guidelines will be used by FLMs to implement the more aggressive FLAG guidance instead of the more flexible BART guidelines. The guidelines must stress that the states retain their flexibility to implement the BART program in their discretion and that the FLMs have only an input role in the process.

Response:

FLMs retain the above mentioned authorities and we believe they play an important role in protecting Class I areas.

7.4 Comments about Specific Class I Areas Comment: Nine commenters provided information on specific Class I areas, illustrating the need to improve visibility, protect plant life, protect aquatic life, result in a healthy park experience, protect the tourism economy, etc. ( 0157, 0158, 0162, 0164, 0166, 0227, 0305, 0313, 0318).

Commenters ( 0225, 28 242) questioned whether Volcanoes National Park should even be considered part of the Regional Haze program given that the Kilauea Volcano is such an enormous known source of naturally occurring SO 2. Commenter 28 242 said natural emissions are responsible for the visibility impacts and the regional haze rules should not apply in this situation.

Commenter 28 399 said applicable public lands should include those designated as national parks and wilderness areas after 1977, including PA's Class II Valley Forge National Park. 207 Response:

We appreciate the additional information on specific Class I areas. We note that changing the list of Class I areas is outside the scope of the BART rulemaking.

7.5 Other Miscellaneous Comments Comment: Three commenters made other comments on the proposal ( 0169, 0173, 0256). Commenter 0169 said states should consider unintended consequences on regional haze during the evaluation of BART requirements and provided an example of development of a detached NO x plume resulting from changes in a power plant's chemistry due to the installation of scrubbers. The plume created haze over the Grand Canyon. Commenter 0173 said biodiesel blends would be a beneficial and applicable retrofit control option that could be included in the final regulations and guidelines and described their uses and benefits. Commenter 0256 asked EPA to neither consider nor respond to comments submitted in 2001 by the commenter because many of these are no longer relevant.

Response:

We appreciate this additional information.

Comment:

Commenter 28 242 said EPA should assist Hawaii's utilities in maintaining air quality while providing reliable power at a reasonable cost to its customers.

Response:

This comment is outside the scope of the BART rulemaking.

Comment: Commenter 28 322 said emissions reductions may not be realized in a timely manner if the legal foundation of BART is open to challenge. EPA should minimize the possibility of legal challenges late in the process.

Response:

We believe the BART guidelines meet the legal requirements of the CAA.

8.0 Editorial Comments Comment: 208 Commenter 0285 suggested changes to conform with the table of contents.

Response: We have tried to ensure consistency in drafting this final rulemaking.

9.0 Comments Unrelated to BART Comment: Two commenters provided comments unrelated to BART in that they discussed EPA's New Source Review policy ( 0149) and the need to finalize mercury pollution rules for power plants ( 0318). Commenter 28 564 was concerned about EPA enforcement of power plants who upgrade old facilities without installing pollution control measures as well.

Response:

This comment is outside the scope of the BART rulemaking.

4.2.3 Presumptive Emission Limits <IP_ADDRESS> SO 2 Limits for Utility Boilers Comment: Thirty four commenters said the proposed SO 2 levels are reasonable ( 0167, 0171, 0227, 0231, 0232, 0234, 0255, 0256, 0267, 0271, 0314, 0323, 28 239, 28 345, 28 247, 28 248, 28 249, 28 250, 28 258, 28 260, 28 262, 28 286, 28 289, 28 302, 28 334, 28 338, 28 350, 28 352, 28 362, 28 399, 28 433, 28 7002, 28 7016, 28 7048) citing examples and references in support of these levels ( 0171, 0255, 0256, 28 302). Commenter 0323 also agreed with EPA's approach of either a specific emission rate limit or level of control for sulfur dioxide that helps to provide equity among sources which use higher sulfur coal and those using coal with inherently lower sulfur content.

Response: The EPA appreciates these comments.

Comment: Commenters ( 28 248, 28 399, 28 7016) said EPA should expand this presumption by applying it to electric generating facilities that are under controlled for purposes of SO x. Commenter 28 258 said the presumptive BART level of SO 2 controls should be required at all utility boilers, not just those with no SO 2 controls.

Response: The final BART presumption for coal fired EGUs with a pre existing SO2 controls are to be determined by States based on an analysis of cost effective FGD upgrades designed to improve 209 the average SO2 removal efficiency of the existing system. The EPA is strongly encouraging States to the implement the BART presumptive limits on coal fired EGUs greater than 200 MW and on all oil fired EGUs regardless of capacity. See TSD " Setting BART Presumptive SO2 Limits for Electric Generating Units" for a more detailed discussion on how EPA determined its final recommendations.

Comment: Nine commenters said the proposed levels are too stringent ( 0176, 0181, 0217, 0246, 0253, 28 264, 28 341, 28 357, 28 7007). Commenter 28 264 said the level is too high for western utilities that are burning low sulfur coal where a level of 85 90% would be more appropriate. One commenter ( 0176) cited his experience with eastern bituminous waste and did not believe the proposed emissions reductions were possible. Commenter 0253 said any default SO 2 control level mandating greater than 90% control are inappropriate for units utilizing wet scrubbers and high sulfur coals. Commenter 28 7007 suggested a range of 70 to 90% would be appropriate.

Response: The EPA is finalizing the SO2 BART presumptive limits based on current FGD capabilities given the various combinations of coal types and sulfur contents inherent in the BART eligible population of units. The EPA is maintaining both an emission limit and percent removal in the final BART presumptive limits to provide equity among various unit specific characteristics and the removal capabilities of different FGD retrofit systems. We also believe that units burning higher sulfur coals can utilize wet scrubbers systems to achieve removal efficiencies of at least 95 percent and units burning lower sulfur coals can utilize semi dry FGD systems to achieve an emission rate limit of 0.15 lb SO2/ mmBtu or less.

Comment: Commenters ( 0217, 0246, 28 357) said if presumptive levels are included, consideration should be given to the levels reflected in the WRAP agreement ( 85% control efficiency at 85% capacity factor.) EPA's presumption of 90 to 95% control efficiency contradicts the consensus based level of SO 2 reduction determined by the WRAP found to be necessary for visibility improvement in western states. Moreover, given that the WRAP stakeholder agreement was determined to be better than BART, the proposed guidelines should not be interpreted to require changes in Section 309 SIPs already submitted under the regional haze rules.

Response: The WRAP agreement covers a much broader universe of emission sources than these presumptive limits, including many smaller sources. We believe the presumptive limits we have provided are strongly supportable as BART limits for the large EGUs covered. See the preamble for further justification.

Comment: Commenter 0181 asked EPA to remove the presumptive SO 2 control level from the final BART guidelines. Instead, there should be a BART determination process that promotes cost 210 effective emission reductions based on specific boiler design features and site specific constraints. The proposed presumptive BART approach, as proposed, does not provide affected states and sources with the flexibility needed to design and install SO 2 emission control systems in a costeffective manner to meet the BART requirements. Furthermore, the presumptive SO 2 emissions control approach inappropriately ignores the need for a visibility impact evaluation which is required in step 5 of the proposed case by case BART engineering analysis.

Response: The EPA believes the final BART presumptive limits promote highly cost effective SO2 emission reductions. The EPA is maintaining both an emission limit and percent removal in the final SO2 BART presumptive limits to provide equity among unit specific characteristics ( i. e. boiler design, coal types, sulfur content, unit size, etc.) and potential FGD retrofit systems. We believe our SO2 presumptive limits provide States enough flexibility to take into account unit specific circumstances. States have the ability to establish alternate BART presumptive limits based on a five step BART analysis given the presence of persuasive evidence. See Section 7 part a, Visibility Analysis for SO2 and NOx emissions from EGUs, in BART Preamble.

Comment: Commenter 28 341 said through switching to Powder River Basin ( PRB) coal, many of Ameren's facilities have met and exceeded the SO 2 reduction requirements of the Acid Rain program. Should BART guidelines be adopted, however, they will be forced to install scrubbers. at each one of their facilities that employs the use of low sulfur coal to meet the proposed 90 95% control levels.

Response: The EPA anticipates States to adopt the BART presumptions on all coal fired BARTeligible EGUs greater than 200 MW. Analysis conducted by EPA suggest that units burning lower sulfur coals and PRB coal can cost effectively retrofit with FGD systems to meet the presumptive limits.

Comment: Four commenters said the proposed presumptive control range is not achievable for existing boilers, and is even more stringent than NSPS limits for new sources ( 28 403, 28 404, 28 405, 28 7013). Commenter 28 403 said EPA's data do not support such a limit nor does EPA explain why the presumption is needed and why the states' discretion should be preempted. Commenter 28 404 said this presumption will result in excessive costs for older equipment. Commenter 28 405 said if presumptive control levels were to be established, they should start at the minimum level of emission controls, with additional controls justified on the basis of the source specific balancing process Congress set forth in 169A. Commenter 28 7013 added that the presumptive limits are more consistent with BACT, which is contrary is contrary to the Act's clear distinction between BART and BACT.

Response: 211 The EPA has recently proposed to revise the NSPS to represent the SO2 control capabilities which are available today. In the proposed NSPS amendments EPA proposed a single limit without a compliance alternative, such as a percent removal as allowed in BART. In setting the NSPS EPA set a higher emission limit than proposed in BART to account for account for the need of future fuel diversity, in particular higher sulfur coals. Conversely, the BART presumptions were established based on the defined population of eligible units and were determined to be achievable by all eligible units. See the preamble for further justification.

Comment: Eleven commenters said that the proposed presumptive limits clearly exceed the statutory authority ( 28 270, 28 342, 28 353, 28 354, 28 356, 28 360, 28 386, 28 390, 28 392, 28 778, 28 7004). Commenters ( 28 270, 28 386, 28 392, 28 778) said that the evaluation must be conducted according to the statutory process and BART must be determined on a case by case basis. Commenters ( 28 342, 28 354, 28 356, 28 360, 28 390) objected to EPA's proposed presumptive limits for SO 2 controls as a flagrant example of EPA usurping State authority and/ or as being arbitrary and economically counterproductive. Commenter 28 7004 added that the Act consciously addresses the need for SO 2 scrubbing in Title IV. The Act does not envision or authorize a much more onerous and expensive nationwide SO 2 scrubbing program as part of Section 169A. The " guidance" which presumes 90 to 95% SO 2 removal as BART for uncontrolled utility boilers is not supported by the law.

Response: See the preamble.

Comment: Three commenters said the proposed levels are too lenient ( 0221, 28 263, 28 7008). Commenters ( 0221, 28 263) said because of the extended SIP timeline, BART retrofits will not be applied until 2013 and therefore, it is expected that the " best" available sulfur removal technologies will routinely be able to achieve in excess of 95% removal efficiencies and emission rates of lower than 0.10 lb/ MMBTU by that time. Therefore, the presumptive level of 95% reduction or 0.10 0.15 lb/ MMBTU SO2 emission rate that is stipulated in the proposal should be strengthened to an SO 2 removal efficiency of 95% or better or an emission rate of 0.10 lb/ MMBTU or better. Commenter 28 7008 was concerned with the effect that setting presumptive minimums would have in a true top down control technology evaluation. Using an artificially low presumptive minimum could eliminate consideration of more effective control options that are still achievable by a given source.

Response: The EPA believes the final BART SO2 presumptive limits represent the removal efficiencies of current FGD systems given the identified universe of BART eligible sources. The final BART presumptive limits require a removal efficiency of at least 95 percent or control to an emission rate of 0.15 lb SO2/ mmBtu or less. States have discretion to set more stringent presumptive limits based on the findings of the five step BART analysis process. 212 Comment: Thirteen commenters specified that proposed control level must account for fuel type and/ or coal sulfur content ( 0171, 0187, 0206, 0213, 0224, 0236, 0241, 0255, 0303, 0314, 28 335, 28 347, 28 770). Commenter 0213 presented historical data showing that the proposed emissions limit could not be attained in certain cases depending upon the sulfur content of the fuel being burned. A statistical approach should be utilized analyzing the performance of existing FGD installations to ensure that the worst case performers can reasonably be expected to comply with the limit. Commenters ( 28 335, 28 347, 28 770) said the presumption should not apply to oil or gas fired utility boilers.

Response: The EPA agrees with the commenters and reiterates that in establishing the BART presumptive limits EPA accounted for variations in fuel type, fuel sulfur content, existing SO2 control systems, anticipated unit cost effectiveness values and the removal capabilities of current FGD systems. The EPA is finalizing BART presumptive limits which include an emission rate limit and a percent removal requirement which it feels to be reasonably achievable by all coal fired BART eligible units absent extreme circumstance. The EPA is finalizing SO2 BART presumptive limits for oil fired EGUs but not gas fired EGUs.

Comment: Commenters ( 0187, 0226, 0224, 0236, 0241, 0303) said the rationale used to justify the default and presumptive BART SO 2 emission limitations for coal fired units can be applied to oilfired EGUs. In contrast to coal fired electric generating units, flue gas de sulfurization has not historically been used at oil fired facilities to comply with SO 2 emission limitations. To the commenter's knowledge, there are no existing oil fired steam electric generating units in the U. S. equipped with flue gas de sulfurization for control of SO 2 emissions. The primary reason for this is that the vast majority, if not all, of the states limit the sulfur content of the oil that may be burned at EGUs as part of their SIP strategy for complying with the SO 2 NAAQS.

Response: Analyses conducted by the EPA in determining the presumptive BART limitations for coaland oil fired EGUs were based on emissions data, anticipated unit cost effectiveness values and current capabilities of SO2 control technologies or methods and their industry applicability. The EPA agrees with the commenters suggestion pertaining oil fired units and notes the final BART presumptions for oil fired units is a limitation on fuel oil sulfur content.

Comment: Commenter 0314 suggested setting the presumptive BART as a range ( 0.1 to 0.15 lb/ MMBTU) allowing the State to establish a specific level for each plant.

Response: The final BART presumptive limits are to be established on a unit by unit basis by the States. States have the ability to establish a SO2 removal efficiency of at least 95 percent or an emission rate limit of 0.15 lb SO2/ mmBtu or less. 213 Comment: Three commenters said that presumptive controls may need to differ depending on the location of the source ( 0244, 0252, 0306). Two commenters ( 0244, 0252) said the presumptive control level of 90% for western units is or may be unrealistic. In contrast to the presumptive level proposed by EPA of 90% SO 2 reduction, WRAP has conducted analysis that the presumptive level of control for a scrubber in the west should be set at 85%. Commenter 0306 said EPA needs to consider the cold climate of certain northern states when determining presumptive BART for SO 2. Cold weather can cause icing of very wet stacks which can lead to safety hazards and functional problems. Reheat of the stack may be necessary, to reduce or eliminate icing problems. Reheating the flue gas by bypassing some of the gas around the scrubber will reduce overall SO 2 removal. The proposed presumptive BART may not be achievable in cold climates without overly burdensome costs.

Response: The WRAP agreement covers a much broader universe of emission sources than these presumptive limits, including many smaller sources. We believe the presumptive limits we have provided are strongly supportable as BART limits for the large EGUs covered. In addition, a State's analysis of the BART factors can take specific circumstances into account. See the preamble for further explanation.

Comment: Nine commenters said that the proposed control levels must account for the type of scrubber in place ( 0171, 0210, 0228, 0229, 0241, 0250, 0253, 0254, 0256). Commenter described the need for site specific analyses to address scrubbers in place ( 0210, 250). Commenters ( 0241, 0254) added that EGUs that currently have SO 2 controls should not be forced to meet the presumptive level unless a full BART analysis is undertaken which shows that incremental visibility and cost effectiveness justify forcing controlled EGUs to meet the more stringent limit. Others ( 0229) said that the recent addition of controls, even if reductions fall below the presumptive levels, should be cause for allowing states to screen such a BART eligible source out early in the evaluation process. Commenter 0254 said the ability to upgrade existing scrubber units will be limited and for many, particularly dry scrubbers, the presumptive 95% reduction level will not be achievable. In addition, many of these units have been installed recently, e. g., since the 1990 Clean Air Act Amendments, and requiring these facilities to re visit large investments in controls, after such a short interval, imparts an excessive burden on those businesses.

Response: The BART presumptions for EGUs with pre existing SO2 controls are to be determined by the States, as either an emission rate limit or a percent removal, based on a unit specific analysis of potential system upgrades designed to increase the average SO2 removal capability of the preexisting system. See the preamble for further explanation. The EPA recognizes that semi dry FGD systems are not typically designed to achieve removal efficiencies of at least 95 percent. For this reason, the EPA anticipates smaller units burning low sulfur coals could utilize the semi dry FGD technologies to achieve an emission rate of 214 0.15 lb SO2/ mmBtu. The EPA also suggests there are cost effective upgrade options for EGUs with pre existing semi dry scrubber systems.

Comment: Commenter 0253 said that in largely focusing on the capabilities of state of the art scrubbers installed on new generating units and ignoring the feasibility or, in many cases, infeasibility of retrofitting such technology on existing units, EPA's analysis is substantially flawed. EPA overlooks the fact that, in many instances, it is technically infeasible to upgrade early generation scrubbers to meet the 95% control level that may be achievable with current state ofthe art scrubbers.

Response: The EPA established the BART presumptive limits for coal fired EGUs without existing SO2 controls based on the control levels achievable with current state of the are new and retrofit scrubber installations. The BART presumption for EGUs with pre existing SO2 controls are to be established by the States ( not necessarily 95 percent control) based on an evaluation of technically feasible upgrade options available for early generation scrubbers in order to improve the average SO2 removal of existing controls.

Comment: Commenters ( 0228, 0256) said the SO 2 presumption should not apply to sources that have already installed and are operating scrubbers, or to sources that have committed to specific levels of scrubbing through consent orders or agreements with EPA or a state regulatory agency. If a source can demonstrate a reduction in visibility impairment below the specified threshold ( whether that threshold is EPA's currently proposed 0.5 deciview or an alternative level) with less stringent controls, EPA and the states should not impose by default more stringent reduction requirements.

Response: EPA's analysis suggest cost effective FGD system upgrades designed to improve average SO2 removal efficiencies are available for some BART eligible units with currently operational scrubber systems. See the preamble.

Comment: In contrast, one commenter ( 0221) said that under controlled sources ( i. e., those previously retrofitted to meet the 1979 NSP of 70 percent) can meet removal efficiencies of 95% or more. The performance of boilers already using the wet limestone process can be improved through the application of " once through wet FGD technology," such as increasing sorbent, reactivity and other upgrades.

Response: EPA analyses suggest cost effective FGD system upgrades designed to improve average SO2 removal efficiencies are available for BART eligible units with currently operational scrubber systems. See TSD " Setting BART Presumptive SO2 Limits for Electric Generating Units" for a more detailed discussion on EPA's list of recommended upgrade options for wet FGD systems. 215 Comment: Eight commenters discussed the role that plant size and/ or capacity should play in applying a default SO 2 control level ( 0206, 0227, 0241, 0253, 0256, 0267, 0271, 0303). Some commenters said that the presumptive limits should not apply to units between 250 and 750 MW ( 0206, 0241, 0303). Commenter 0253 said EPA should clarify that only BART eligible sources would be counted toward the 750 MW cut off. Commenters ( 0206, 0303) added that Congress did not specify similar requirements for smaller plants ( i. e. facilities below 750 MWs). The installation of controls necessary to reduce SO 2 emissions by 90 to 95 percent is more likely to be uneconomical at smaller facilities ( 0206, 0253, 0303). The BART process must be followed for such a determination to be made ( 0241).

Response: The BART presumptions are binding for units greater than 750 MW. EPA strongly encourages States to apply the BART presumptive limits to units greater than 200 MW regardless of plant size. The EPA's unit specific economic analysis for BART eligible coal fired units suggests on average it is less economical for units less than 200 MW to retrofit with FGD systems than those units greater than 200 MW. However, the analysis did demonstrate that some BART eligible units less than 200 MW were modeled to have cost effectiveness values comparable to those unit greater than 200 MW and that States are encouraged to apply the BART presumptions to such sources.

Comment: Commenter 0256 said EPA's proposed distinction between the SO 2 " default requirement" and the " rebuttable presumption" based on total power plant capacity is unsupportable. Because BART applies on a unit basis, the fact that the total capacity of the plant is higher or lower than 750 MW has no obvious bearing on whether an individual unit can meet the default/ presumption. Indeed, if anything, units at a larger plant would perhaps have more problems meeting the presumption than would units at a smaller plant, because a larger plant would tend to have more units and thus more potential for space constraints in retrofitting add on controls. If EPA retains the SO 2 presumption, it should be a rebuttable presumption for all units greater than 250 MW, regardless of total power plant capacity.

In contrast, commenters ( 0227, 0271) said EPA should require presumptive controls for all units at 750 MW plants, including those between 250 and 750 MW. Commenter 0271 said this conforms to the specific wording of the Act ( Sec. 169A( b)( 2)( A)) for controls on these smaller than 750 MW units. Commenter 0267 supported applying the proposed presumptive level to all EGUs greater than 250 MW.

Response: See the preamble.

Comment: Commenter 0268 noted that Arizona has chosen to address visibility impairment through Section 309 of the 1999 RHR. In order to pursue the 309 pathway, Arizona has made a 216 demonstration to EPA that the state will realize overall SO 2 reductions greater than the reductions that would be achieved solely through imposition of BART controls at the state's BART eligible sources. EPA should clearly and definitively recognize that presumptive BART limits for SO 2 do not apply to BART eligible sources located in states that have already committed to " better than BART" SO 2 reductions through Section 309 SIP submittals.

Response: We agree.

Comment: Twelve commenters suggested alternatives to presumptive control levels ( 0213, 0215, 0256, 0302, 28 255, 28 256, 28 264, 28 266, 28 278, 28 312, 28 355, 28 404). Commenter 0213 supports an emissions trading program to implement BART controls as proposed in the June 10, 2004 Clean Air Interstate Rule ( CAIR). However if an individual unit program is prescribed, the commenter supports a percent removal limit as opposed to an emission limit.

Response: EPA appreciates these comments and supports BART eligible units option to opt into the CAIR in applicable states.

Comment: Commenter 0215 said EPA should retain the option of complying with the SO 2 default/ presumption for EGUs, either by adhering to the straight percentage reduction or a set emission rate. Due to the variability in coal and equipment types ( including vintages), EPA must retain flexibility for those EGUs that must comply with these BART requirements.

Response: The EPA appreciates this comment.

Comment: Commenter 0256 agrees with EPA that, for units burning lower sulfur coal, achieving 95% reduction could be problematic and that an emission limitation should be used. Other commenters ( 28 256, 28 264, 28 266, 28 278, 28 312, 28 355, 28 404) agreed if a presumptive approach is used, then the presumptive norms should be explicitly stated in the rulemaking and should be no higher than 3.0 lb/ MWh for SO 2 ( 28 256), based on a weight rate limit or other fuel neutral basis to account for facilities burning higher sulfur coal ( 28 264, 28 335), on an emissions standard to allow sources to take credit for improvements they have already made ( 28 266, 28 278, 28 312, 28 404).

Response: The EPA conducted a unit specific analysis in determining the BART presumptive limits and is finalizing presumptions which it feels to be achievable by the BART eligible population, absent extreme circumstances. The final BART presumptive limits for coal fired EGUs without existing SO2 controls includes both an emission rate limit and percent reduction requirement to 217 provide equity among the units and their various characteristics. See the preamble for further explanation.

Comment: Commenter 0302 prefers the flexibility of a percentage control level comparable to a performance level of 0.1 to 0.15 lbs/ MMBTU SO 2. A percentage control level would offer the non EGU BART subject sources the best controls that are achievable, for all types of sources, under reasonable cost effectiveness. Without the proper guidance for BART subject sources that are EGUs, the commenter needs flexibility in determining the actual emission rates at which these sources will be required to demonstrate compliance.

Response: See the preamble.

Comment: Two commenters ( 28 255, 28 264) said the presumptive levels should not be established as absolute values. Commenter 28 255 said the values should be presented as a range. Commenter 28 264 said the presumption should not interfere with the states' discretion and statutory process. If EPA intends to apply this " presumptive level" as a mandate, then EPA should establish it as a national rule rather than continuing the pretense that states are making a case by case determination.

Response: See the preamble for explanation of the circumstances under which the presumptive limits apply.

Comment: Three commenters discussed the role that the averaging period plays in determining performance ( 0213, 0256, 0314). Commenter 0213 noted the difference in performance over longer averaging times between state of the art technology and existing FGD installations. EPA should review existing installations to determine an appropriate level of performance for determining an SO 2 removal efficiency limit. Commenter 0256 said the choice of 0.15 lb/ MMBtu is predicated on the use of at least an averaging time of 30 day rolling or longer. The 0.15 lb/ MMBtu limit could not be achieved with the use of a shorter averaging time. Commenter 0314 asked that an averaging period, i. e., a 30 day rolling average, for the control levels be established in the rule. A longer averaging period will allow for lower annual emissions.

Response: The EPA recognizes the correlation between sustainable FGD performance and length of averaging times. For this reason it is establishing as part of the BART rulemaking a 30 day rolling averaging period for the SO2 presumptive limits.

Comment: 218 Four commenters said that EPA has underestimated the cost per ton of emissions removed ( 0187, 0206, 0236, 0303). Commenters ( 0187, 0236) provided an example of the costeffectiveness range for reducing SO 2 emissions to 0.1 to 0.15 lbs/ MMBTU estimated to be between $ 1800 and $ 3400 per ton of SO 2 removed when burning Powder River Basin coals. This is much higher than the $ 200$ 1000 per ton cost effectiveness range cited by EPA in support of the proposed presumptive BART SO 2 limit. Commenter 0187 gave an example of an oil fired unit exceeding $ 3,000 per ton of SO 2 removed, which supports a separate presumptive SO 2 emission limit for oil based units based on the maximum fuel sulfur content in oil. Commenters ( 0206, 0303) were concerned about additional costs faced by smaller plants ( upgrading fans, piping, etc.) that can drive the cost into the $ 3,000 range. The commenters said EPA should treat smaller plants like other major sources and allow states greater flexibility in determining BART for such facilities.

Response: EPA's unit specific economic analysis suggests an average cost effectiveness, for all BART units greater than 200 MW, of $ 919 per ton SO2 removed, with a majority of the units anticipated to have cost effectiveness values ranging from $ 400 to $ 2000 per ton SO2 removed, see TSD " Setting BART Presumptive SO2 Limits for Electric Generating Units" for a more detailed discussion on how EPA determined its final recommendations. EPA's economic analysis also suggested that some unit greater than 200 MW could experience expensive cost effectiveness values, however States have the flexibility to determine alternate BART presumptive limits based on the results of the 5 part BART analysis. The EPA strongly encourages States to apply the BART presumption at units greater than 200 MW because our economic analysis suggested higher average cost effectiveness values for units less than 200 MW. However, EPA also recognizes that some units less than 200 MW were modeled to have reasonable cost effectiveness values. The EPA determined the final BART presumption for oil fired units to be a limitation of fuel oil sulfur content.

Comment: In contrast, commenters ( 0221, 0267) said achieving the control levels are cost effective.

Response: The EPA appreciates these comments.

Comment: Six commenters provided other comments regarding SO 2 limits for utility boilers ( 0215, 0224, 0241, 0250, 0255, 0319). Commenter 0215 said if EPA retains the SO 2 default/ presumption, it should make it clear that if any source is willing to achieve 95% control or somewhere along the scale of 0.10 to 0.15 lb/ MMBtu, it should automatically be exempt from the requirement to perform a BART analysis for SO 2. Commenter 0224 said EPA might specify flue gas desulfurization as a presumptive technology. Commenter 0255 described several options that are available to further reduce SO 2 emissions and improve the reliability of existing FGD systems to above 95 % removal efficiencies. 219 Response: See the preamble and the technical support document: " Setting BART Presumptive SO2 Limits for Electric Generating Units".

Comment: Commenters ( 0241, 0250) opposed establishing any SO 2 control level for EGUs as presumptive BART because this usurps state authority and completely ignores the BART evaluation process required by the Act. Commenter 0250 said this is especially inappropriate for units already equipped with scrubbers.

Response: See the preamble.

Comment: Commenter 0319 was concerned that setting an emission rate goal incorporating cap and trade mechanisms rather than a percent control goal would encourage fuel switching to SPRB coal. Even plants that meet the BART standards would be encouraged to switch to SPRB coal to avoid capital investment or to profit from the sale of surplus allowances. Tribal coal and lignite production could be put at risk. The commenter provided a proposal to address the impacts on tribal coal as Attachment A.

Response: The final BART presumptions do not include a cap and trade program for EGUs. EPA believes the BART presumptive limits for EGUs are stringent enough that fuel switching alone will not bring a unit into compliance with the 0.15 lb SO2/ mmBtu emission rate limit. The final BART presumptions for coal fired EGUs without pre existing SO2 controls were finalized based on what EPA believes are the current capabilities of wet and semi dry FGD systems.

<IP_ADDRESS> General Comments Regarding Presumptive Limits Comment: Seven commenters supported the use of presumptive emission limits in the BART program ( 0179, 0221, 0255, 0285, 0299, 0323, 28 266). Commenters said the limits are achievable ( 0179, 0255) and are one of the most essential components of the BART guidelines because they establish a starting point representing the " best available technology" in the required engineering analysis ( 0221). Some commenters requested that EPA establish more stringent limits and harmonize the presumptive BART emission limits for EGUs under the regional haze program with the BART guidelines ( 0221). Commenter 0323 approved including a specific BART determination for large, bituminous coalfired electric generating stations. These facilities constitute the largest emitters of sulfur dioxide and nitrogen oxides among all 26 source categories subject to BART. 220 Commenters ( 0285, 28 266) urged EPA to develop national guidelines and presumptive BART requirements for source types common to several states to make the process more efficient and workable for the states. Commenters ( 0299, 28 266) added that the guidelines should encourage consistency between states and said EPA should establish a consistent set of protocols upon which a BART analysis for each source category should be based. Commenter 0299 added that such protocols should not eliminate the flexibility each state may need to address unusual circumstances at individual sources, but these protocols could potentially eliminate the need for case by case review for many sources. In the absence of a presumptive standard, the proposed BART guidelines must contain explicit criteria for determining BART. In addition, the BART Guidelines should include defined criteria for " engineering", " useful life", and " cost".

Response: We agree with these comments; see the preamble for justification of the specific presumptive limits.

Comment: Several commenters said EPA should establish presumptive limits for other pollutants and/ or source categories ( 28 248, 28 255, 28 358). Commenter 28 255 would also seek to establish limits for source categories in addition to utility boilers to make the process more uniform and consistent across the country and easier for the states. Commenter 28 358 said the SO 2 limits should be expanded for all BART eligible industrial boilers in all 26 categories and set at 95% to reflect control technology performance. Commenter 28 248 proposed setting a limit for particulate matter at 90%.

Response: We believe BART determinations are to be conducted by States under the CAA; we further believe presumptive limits for NOx and SO2 for specific large EGUs are justified based upon our analysis discussed in the preamble and technical support documents ( TSDs).

Comment: Forty nine commenters opposed establishing presumptive emission limits ( 0171, 0181, 0184, 0195, 0197, 0198, 0208, 0210, 0211, 0214, 0215, 0217, 0224, 0226, 0228, 0238, 0244, 0246, 0247, 0252, 0253, 0254, 0256, 0268, 0270, 0275, 0276, 0308, 0314, 0321, 28 243, 28 264, 28 267, 28 305, 28 333, 28 340, 28 342, 28 347, 28 354, 28 356, 28 357, 28 360, 28 385, 28 390, 28 401, 28 402, 28 748, 28 7003, 28 7009).

Commenters said this approach restricts the flexibility of the states and/ or sources to make the control technology evaluations on a case by case basis ( 0171, 1081, 0195, 0197, 0211, 0217, 0247, 0253, 0256, 0268, 0275, 0276, 0321, 28 243, 28 305, 28 333, 28 340, 28 342, 28 349, 28 354, 28 357, 28 360, 28 385, 28 390, 28 748) without resulting in a notable degree of improvement to visibility ( 0171, 0197).

The Act requires states to use the statutory factors in making case by case BART determinations ( 0195, 0197, 0210, 0211, 0217, 0228, 0238, 0244, 0246, 0247, 0252, 0253, 0256, 221 0268. 0308, 0314, 0321, 28 264, 28 267, 28 347, 28 355, 28 357, 28 359, 28 360, 28 385, 28 390, 28 401, 28 402, 28 747, 28 748, 28 7001, 28 7003, 28 7009). Commenters ( 0211, 0217, 0246) added that, rather than assist states by providing them with resources, tools and guidance under BART guidelines, EPA's use of rebuttable presumptions will tend to require significant levels of state resources for states to exercise discretion in their BART determination processes. Most states have limited administrative resources to address these issues and therefore, EPA's use of presumptive requirements will discourage state level discretion  opposite the intent conveyed by the Coin Growers decision.

Commenters ( 0198, 0226, 0254) said the presumptive levels are not achievable across the range of boiler types, vintage of existing controls and coal composition. Commenter 0198 preferred the use of trading under CAIR to meet BART requirements in the most efficient and cost effective manner. Commenter 0226 said if a presumptive level of control/ emission rate is retained in the final rule, the guidelines should, at a minimum, make it clear that states have the authority to select an alternative level of control/ emission rate, without an undue evidentiary burden, given appropriate consideration of all the statutory BART factors. Commenter 0253 asked that EPA either delete the provisions for mandatory default control levels or provide a source with the option of using the default control levels, rather than making them mandatory. Commenter 0276 said if EPA establishes presumptive control levels for EGUs, average annual values are more appropriate than those in the proposed regulations. In addition, BART should not be structured in a way that results in rigid technology based limits that interfere with established NO x and SO 2 emission trading programs. Commenter 0314 said if EPA needs to define a target, it should use a range to prevent diminishing states' flexibility in case by case BART reviews.