BEFORE THE

US ENVIRONMENTAL PROTECTION AGENCY

PROPOSED RECONSIDERATION OF NATIONAL EMISSION

STANDARDS FOR INDUSTRIAL, COMMERCIAL AND INSTITUTIONAL

BOILERS AND PROCESS HEATERS (40 CFR 63 SUBPART DDDDD )

Docket ID No. EPA

- HQ

- OAR

- 200 2

- 0058

COMMENTS OF AMEREN CORPORATION

Michael Hutcheson

Ameren Services

1901 Chouteau Avenue PO Box 66149, MC 602 St. Louis, MO 63166

- 6149Comments and Data Provided by Ameren

on the US EPA Reconsideration of the Major Source Industrial Boiler MACT

Ameren Corporation is pleased to provide the following comments on the proposed

Reconsideration of the final National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial and Institutional Boilers and Process Heaters (Boiler MACT).

A meren Corporation is a producer and supplier of electricity and natural gas in three states in the Midwest. As a member of UARG, Ameren Corporation would like to herein endorse and adopt the comments submitted by UARG.

In addition to the UARG comment s, Ameren has prepared the following comments

, information and data for US EPA’s consideration during the Boiler MACT

reconsideration process.

1. Ameren agree s with US EPA’s inclusion of a limited use boiler and process heater subcategory in the final rule. However, Ameren believes improvements to the definition of limited use boilers or process heaters can easily be made without compromising air quality. Amere n requests that US EPA reconsider the use of a straight hourly threshold for defining the limited use subcategory. As an alternative, US EPA should consider changing the definition of limited use to : “Limited

- use boiler or process heater that burns any am ount of solid, liquid, or gaseous fuels, has a rated capacity of greater than 10 MMBtu per hour , and has an annual capacity factor of no more than 10 %.” The definition of annual capacity

factor should then be added to the definitions in 40 CFR 63.7575 a nd it should be the same as the definition of annual capacity factor in both 40 CFR 60.41b and 40

CFR 60.41c.

Ameren has several auxiliary boilers located at Ameren facilities for use when all facility electric generating units are offline at the same tim e. These units typically do not operate more than 876 hours per year and could meet the definition of

limited use boilers. H owever, on rare occasions these boilers are required to operate more than 876 hours per year to return the electric generating fac ility to

service . Ameren has recently encountered this issue during installation of flue gas

desulfurization systems at one of our facilities. Because the outages for the tying

in of t wo FGD systems at two units at one facility occurred over the course o f

several months, the auxiliary boiler at that facility was required to operate more

than 876 hours over a 12 month period. Conversely, this auxiliary boiler never approache d a capacity factor of 10 % despite operating for up to 1,950 hours during a 12 mo nth period

.

Because emissions of HAPs are directly proportional to capacity factor as opposed to time on line, capacity factor is a much better substitute for defining the limited use subcategory. Emissions from the auxiliary boiler above never

approa ched those of a boiler operating at design heat input for 876 hours as allowed under the current limited use exemption. Just because the boiler was needed for more than 876 hours to meet facility needs should not elevate the

boiler out of the limited use subcategory if the capacity factor remains less than

10 %.Comments and Data Provided by Ameren

on the US EPA Reconsideration of the Major Source Industrial Boiler MACT

Additionally, this MACT standard and other recently proposed MACT standards (EGU MACT) will require significant changes to air pollution controls at various sources in short time spans and long ou tages will result. In order to achieve compliance with these new standards the auxiliary boilers at Ameren facilities will have significantly i ncreased demands on their time . Without a change to the definition of limited use boilers, Ameren’s auxiliary b oilers may have to forgo

limited use status in order to accommodate steam needs at their facilities while

other units at the ir facility upgrade pollution control devices to meet the new EGU MACT or other newly promulgated federal standards (Transport Rule) . This will result in significant costs with little air quality benefit.

For limited use boilers, the economics of installation of ESPs or fabric filters and activated carbon injection for Hg control, wet scrubbers for control of acid gases and potenti ally catalytic oxidizers for the control of organic HAPs is not cost effective. Assuming a no.2 fuel oil fired 250 MMBtu/hr auxiliary boiler with a 10 % capacity factor and using AP

- 42 particulate emission factors, average PM2.5 and Hg factors from the US EPA emission test database for the Boiler MACT rulemaking, the particulate emissions from that boiler is on the order of 1.5 tpy, PM2.5 on the order of .3 tpy and Hg on the order of 0.33 #/yr. Taking for granted the US EPA summary of Capital and Annual C osts for control in Table 11 of the Preamble of the proposed rule, the average annualized cost of control for existing liquid fuel fired boilers after considering fuel savings is $507,000 per boiler. In terms of cost effectiveness, assuming 100 % reductio n of all three pollutants, the annualized cost of reduction is $ 3 38 ,000 per ton of PM reduction, $1, 536 ,000 per ton of PM2.5 reduced and $1, 69 0 ,000 per pound of Hg reduced. We include PM and PM2.5 for this analysis because US EPA’s benefits analysis for t his proposed rule is based on PM2.5 reductions. At these costs, it does not make sense to require controls on limited use boilers even as large as 250 MMBtu/hr.

In addition, in the case of limited use boilers/process heaters, it is not practicable

econ omically to require sources which operate infrequently to undergo the expensive measurement methodologies at non

- detectable levels. Ameren’s limited use/auxiliary boilers typically operate only during outages at the electrical generating units. Conductin g stack testing during these infrequent outages which may last only very short periods at some plants is nearly impossible. Stack testing during significant EGU outages is not feasible due to the large numbers of contractors and maintenance personnel enga ged in activities associated with returning electrical generating units back into service.

Ameren requests that US EPA reconsider the use of only a single subcategory for liquid fuel units. As Ameren and several other commenters noted during the

comment period for the proposed rule, there are several physical differences between boilers designed to burn lighter fuel oils (#1 and #2) and those designed to burn heavier oils (#4 and #6). US EPA acknowledges those differences in its response to comments made by Randolph Price of Consolidated Edison (Pgs. 260 to 262 of volume 2 of US EPA’s Response to Comments). Although elsewhereComments and Data Provided by Ameren

on the US EPA Reconsideration of the Major Source Industrial Boiler MACT

US EPA denies there is significant data or technical justification for a separate subcategory for heavy and light liquid fuel fire d boilers or other non

- petroleum based liquid fuels, in its response to comments from David Peightal of Dakota Gasification (Page 271 of Volume 2 of US EPA’s Response to Comments), it

seems to come to a different conclusion when there are less differences separating gas fired units in the gas 1 and process gas subcategories. US EPA needs to explain why it appropriate to subdivide boilers designed to burn gaseous fuels but is inappropriate to do the same for liquid fuel fired boilers even though there are

s ignificant differences between boilers designed to burn heavy fuel oils and those designed to burn light fuel oils

.

2. Ameren requests US EPA reconsider whether a threshold higher than 10 million Btu per hour meets the technical and economic limitation s as specified in CAA section 112(h). Ameren raised this issue during comments on the proposed Boiler MACT but could not find that US EPA responded to this issue in the preamble or in the response to comments documents. Ameren believes that US EPA should consider setting only work practice standards for all liquid fuel fired boilers and process heaters below 100 MMBtu/hr as it does for units of all sizes in the gas 1 subcategory

. Assuming a no.2 fuel oil fired 100 MMBtu/hr auxiliary boiler and using AP

- 4 2 particulate emission factors, average PM2.5 and Hg factors from the US EPA emission test database for the Boiler MACT rulemaking, the particulate emissions from that boiler is on the order of 6 tpy, PM2.5 on the order of 1.8 tpy and Hg on the order of 1. 2 #/yr. Taking for granted the US EPA summary of Capital and Annual Costs for control in Table 11 of the Preamble of the proposed rule, the average annualized cost of control for existing liquid fuel fired boilers after considering fuel savings is $507,00 0 per boiler. In terms of cost effectiveness, assuming 100 % reduction of all three pollutants, the annualized cost of reduction is $ 8 4,5 00 per ton of PM reduction, $ 28 2 ,000 per ton of PM2.5 reduced and $ 422

, 5 00 per pound of Hg reduced. We include PM and PM2.5 for this analysis because US EPA’s benefits analysis for this proposed rule is based on PM2.5 reductions. At these costs, it does not make sense to require controls on small liquid fuel fired boilers as small as 100 MMBtu/hr.

3. Ameren requests that US EPA reconsider their position on whether CAA 112(d)(3) requires that the MACT floors be based on test data from a minimum of 5 sources. In the preamble to the final rule, US EPA when responding to comments that it is inappropriate to set limits fo r a category with more than 30 sources using the testing from less than 5 sources only says that “the literal language of the provision appears to compel this result.” This is true only when EPA reads Section 112(d)(3) subparagraph ( A ) applying the parenthetical clarification to the term sources and presuming the clarification does not apply to all uses of that term in the paragraph. If the term sources is limited in the first part of the paragraph to only those sources which the admini strator has emission information, then the term sources in the last part of the paragraph must have the

same limitation. When the Act says “ in the category or subcategory for categories and subcategories with 30 or more sources ”, the term sources must not be read toComments and Data Provided by Ameren

on the US EPA Reconsideration of the Major Source Industrial Boiler MACT

be different than it is defined above in the same paragraph. Consequently, the number of sources in the category or subcategory is defined by the number of

sources for which the administrator has emissions information. EPA errs when it

reads the same term differently in the same paragraph.

Ameren commented on this issue in comments on the draft rule, however, it did not appear that US EPA considered these comments as it did not respond to the

assertion that it must read the same term in a paragraph the same way when it appears more than once . These comments are repeated here. Specifically, Ameren believes, Section 112(d)(2) of the Act states that the “Emission standards promulgated under this Subsection ... shall require the maximum degree of reduction of emissions of the hazardous air pollutants subject to this section...that the Administrator, taking into consideration the cost of achieving such emission reduction ... determines is achievable”. Section 112(d)(3) defines the maximum degree of reduction in emissions that is deemed achievable as (1) the emission

control that is achieved in practice by the best controlled similar source for new sources and (2) no less than the average emission limitation achieved by the best performing 12 percent of existing sources or the best performing 5 sources in source categories (or subcategories) with fewer than 30 sources. A direct reading

of this subsection of the Act indicates that if there is test data from fewer than 30 sources, MACT standards can be no less than the average emission limitation achieved by the best performing 5 sources. The language in this section of the Act clarifies through parenthetical insertion that the number of sources in a subcategory is determined by the number of sources “ for which the Administrator has emissions information”. It is incredulous to think that Congress wanted the US EPA to develop MACT standards for source categories with thousands of different sources from fewer than five (5) data points when it requires th e use of at least 5 data points for categories with fewer than 30 sources. This is directly contrary to basic scientific and probabilistic principles and therefore contrary to the Administrators statements on the use of good science in making policy

decis ions. US EPA cannot believe that two dioxin/furan stack tests for coal

- fired boilers can adequately represent the emission limitation achievable by top performing 12 % of boilers when there are 578 coal fired boilers affected by the

rule.

4. Ameren reques ts that US EPA reconsider their position on how to rank test results

from individual sources. Ameren believes US EPA errs when it ranks the best

controlled sources according to the single best test value when multiple test data are available. By using th e single best test value, US EPA biases the ra nkings of the best performers and is not ranking the units according to the ability of a unit to

achieve an emission limitation or a real qualitative assessment of the ability of a unit to control the pollutant in question

. T he Act requires that US EPA base the MACT floor on the best performing sources. According to US EPA in the preamble to the final rule, the test to determine a best performer for use in setting the MACT floor is how a unit performs during i ts single best emission test

. Ameren believes a single test result is not an indication of a unit’s ability toComments and Data Provided by Ameren

on the US EPA Reconsideration of the Major Source Industrial Boiler MACT

achieve an emission limitation or an indication of a unit’s ability to control the pollutant when other test results for that source are higher than the test average used as the qualifier and indicate that the source does not control the pollutant as

well as it is ranked

. I f a single test is to be use d

, the highest test value with a suitable variability factor applied (which takes into account t he long term source variability) is a better indicator of a unit’s ability to consistently achieve an emission limitation not a single low test value

. It is not reasonable, as US EPA asserts, to determine that one low test is indicative of the ability of a source to control a pollutant when other tests indicate otherwise. It is arbitrary to pick the

lowest test results for sources with more than one tes t and to ignore the other tests when ranking that source. US EPA suggests that by taking into account the other tests during the UPL calculations, the US EPA has accounted for the data. However, this can’t substitute for incorrectly ranking sources by ig noring data indicating they are not as well controlled as the single best test might indicate.

5. Ameren requests that US EPA reconsider how it determined MACT floors. As commented on during the comment period for the proposed Industrial Boiler MACT, Ame ren thinks the MACT floor should be based on the 88 th percentile of emission data not the average emission rate for the lowest emitting 12 % of sources. Ameren believes that the US EPA errs when it takes the average of the top 12 % of all data when determ ining the MACT floor. We believe the US EPA should actually be utilizing the 88 th percentile of data instead of the average of the top 12 %. Ameren interprets Section 112(d)(3) of the Act to require that the MACT floor be based on an average emission rat e that is achievable by all 12 % of the top performing sources. By using the average or mean of the top 12 % of sources, US EPA sets a MACT floor that is not achievable by those sources

between the 88 th and 94 th percentiles. The use of the words “average emission limitation” would reflect that Congress intended that compliance with the limitation would be based on averaged data over a period of time such as a three run stack test. It does not reflect that Congress intended for the MACT floor to be

based on an average of the top 12 % of test data. If the latter were true, as US EPA seems to believe, then Congress must have known that half the sources in the top 12 % could not have “achieved” the “average emission limitation achieved” making the word “achi eved” superfluous. This is contrary to the basic rules for statutory construction.

6. Ameren requests US EPA review Dioxin/Furan r eporting used to establish the

MACT Floor because it is inconsistent resulting in inaccurate characterization of the best pe rforming sources

. Dioxin/furan MACT Floor for the liquid fuel subcategory is based on 2 test results out of 1 3 after the emissions test database was purged of 4 tests after the proposed rule . The test results for dioxin/furan are reported as individual c ongeners and as a total which is the sum of the individual

congeners. As previously commented on during the comment period on the proposed rule, t he lowest TEQ results reported and used to establish the MACT floor for the liquid fuel subcategory only repo rted 17 congeners. All other Facilities reported either 21 or up to 25 congeners except the Virginia NewportComments and Data Provided by Ameren

on the US EPA Reconsideration of the Major Source Industrial Boiler MACT

News Shipbuilding facility boiler 78

- E1 which was originally ranked 13th out of

17 and now ranks 11th. The Newport News boiler test reported all congeners

non

- detect, however, because the detection limits reported for that test were much higher than most other tests, the reported TEQ level was higher than 10 others in the subcategory. Conversely, the MACT Floor was based on the only two other

sour ces who reported only 17 congeners. By reporting fewer congeners, the sources used to establish the MACT floor have a biased low TEQ value which is the sum of the 17 congeners TEQ values. Because only one of the 17 Facilities reported detectable levels o f dioxin/furans, the only basis to establish the t wo sources as the MACT floor is due to their limited reporting of congeners , if the other sources had reported only 17 congeners, the rankings may have been

different . Because this MACT floor and the resul ting standard are based on only seventeen congeners and the rest of the facilities reported additional congeners,

the MACT floor is biased. US EPA should require that all reporting be consistent. The dioxin/furan floor must be based on test rankings whic h all report the same congeners and the same number of congeners.

7. Ameren requests that US EPA re consider t he Boiler MACT’s requirement to conduct an energy assessment to identify cost

- effective energy conservation

measures. Ameren believes that US EPA errs when it describes an energy

assessment as a standard because it is “a requirement that can be enforced” (76 FR 15633, March 21, 2011)

. US EPA knows that Section 112(d)(2) of the Act requires that MACT standards be “measures, processes, methods, syste ms or techniques including but not limited to measures which ... reduce the volume of, or eliminate emission of such pollutants through process changes, substitution of materials or other modifications.” As Ameren asserted previously in comments on the prop osed rule, an energy audit is not a measure, process, method, system or technique that reduces the volume of, or eliminates emissions of any pollutants. An energy audit is a measure of the efficiency to which a system utilizes energy. An energy audit is not a requirement to change steam process to be more efficient. US EPA is correct that the audit itself can be enforced, but the audit cannot reduce the volume of, or eliminate emissions of any pollutants and therefore does not

meet the definition in Sect ion 112(d)(2) of the standards which must be promulgated

. To assert otherwise is to claim that measuring a line can make the

line shorter.

Additionally, US EPA mischaracterizes the benefit s from energy audits when it says that “the energy assessment will generate emission reductions through the reduction in fuel use beyond those reductions required by the floor.”(76 FR 15632, March 21, 2011) A review of the efficiency measure upgrades in the

stud y completed by the US DOE upon which US EPA relies indicates that the

some of the more cost effective efficiency upgrades will result in increased

emissions and not reduced emissions. T he US DOE study includes in its top recommendations fuel switching fro m Natural G as to fuel oil to reduce fuel

co nsumption

. According to the DOE study, the energy efficiency upgrade thatComments and Data Provided by Ameren

on the US EPA Reconsideration of the Major Source Industrial Boiler MACT

results in the most cost and energy savings is from switching from Natural Gas to

the use of more efficient fuel s such as fuel oil

. Thi s results in a more efficient fuel combustion process and reduced fuel use but also results in increased HAP

emissions from fuel oil combustion. Implementing this recommendation would therefore result in an increase in HAP emissions. This “energy efficie ncy” project was actually proposed during the course of the US DOE study numerous times over the three study years and underlies the reduced fuel use assertions made by US EPA. Unfortunately, reduced fuel use in this case does not lead to reduced

emission s. Consequently, US EPA cannot use this US DOE study as a basis for claiming energy assessments result in reductions in emissions

.

8. Ameren requests that US EPA review emission data used to develop the MACT

Floor. Ameren believes that the emission tes t data for the BP facility in Decatur, Alabama is incorrectly listed as a liquid fuel fired boiler. Discussions with environmental representatives with the facility indicate that the boiler has not combusted the by

- product fuel used for the compliance tes t used to establish the

MACT floor for PM. Boiler AB

- 8301 normally combusts natural gas and the fuel used for the compliance test was burned only to reserve the capability to combust that fuel under the facility permit. Additionally, Ameren believes that it is improper to utilize data from the Milliken plant in South Carolina to establish liquid fuel fired boiler MACT floors. The boiler test data is based off of testing conducted at 4.3 MMBtu/hr which is significantly below the size limitations of

the su bcategory and is less than 50 % load for the unit (10.5 MMBtu/hr design rate) . Testing for compliance with all NESHAP and NSPS standard s is required

to be conducted under representative load conditions (40 CFR 63.7(e)(1) and 40 CFR 60.8(c)

. If representative conditions for this unit are at 4.3 MMBtu/hr, then the unit should not be included in a subcategory for units greater than 10 MMBtu/hr. Additionally, testing at less than 50 % load will not produce the highest emission rates for a unit and creates a bias in the data. If this unit has been judged as a best performer simply because it operates significantly below it s design rating during testing, then the unit should not be included as a best

controlled source.