Response to Public Comments 

The Amalgamated Sugar Company LLC (TASCO) 

Nampa Factory 

Nampa, Idaho 

Facility ID No. 027-00010 

Tier II Operating Permit No. T2-2009.0105 Project 60867 

December 23, 2011 

Morrie Lewis 

Permit Writer 
 T2-2009.0105 Project 60867 Page 2 

BACKGROUND 

As deemed appropriate by the Director, the Idaho Department of Environmental Quality (DEQ) 

provided for public comment on the proposed permit from October 31, 2011 through 

November 30, 2011 in accordance with IDAPA 58.01.01.404.01.c. During this period, comments 

were submitted in response to DEQ’s proposed action. Each comment and DEQ’s response is 

provided in the following section. Comments with a common theme have been grouped together 

and responded to as one comment. All comments submitted in response to DEQ’s proposed 

action are included in the appendix to this document. 

Additional information concerning this permitting action, the BART and BART Alternative 

determinations, and the Regional Haze program and its requirements can be found in the 

following documents: 

• Tier II Operating Permit No. T2-2009.0105 Project 60867 and Statement of Basis (proposed 

for issuance) 

• Tier II Operating Permit No. T2-2009.0105 and Statement of Basis, issued September 7, 2010 

• State of Idaho Regional Haze State Implementation Plan (Regional Haze SIP) and Interstate 

Transport Plan, Final and Proposed Rules 

• www.deq.idaho.gov/air/prog_issues/pollutants/haze_overview.can 

• www.epa.gov/visibility/program.html 

PUBLIC COMMENTS AND RESPONSES 

Public comments regarding the technical and regulatory analyses and the air quality aspects of the 

proposed permit are summarized below. Questions, comments, and/or suggestions received 

during the comment period that did not relate to the air quality aspects of the permit application, 

the Department’s technical analyses, or the proposed permit have not been addressed. For 

reference purposes, a copy of the Rules for the Control of Air Pollution in Idaho can be found at: 

http://adm.idaho.gov/adminrules/rules/idapa58/0101.pdf. 

Comment 1: Will the project or the proposed controls address odors? (Freeman) 

Is this project mainly about plant efficiency, to reduce NOx emissions, or to reduce ozone 

formation? (Johnson) 

Response: The primary focus of this project is to reduce visibility impacts and to reduce regional haze to 

meet Regional Haze program requirements. 

Odors were not the primary focus of this project, and impacts were not assessed. Although the 

project reduces combustion emissions from the boilers at the Nampa Factory, the process 

equipment and the emissions from these processes are not expected to change. So with regard to 

odors, a change may or may not be noticeable. 

Although the implementation of BART controls will result in the reduction of NOx emissions and 

thereby reduce ozone formation, this additional environmental benefit was incidental to meeting 

the requirements of the Regional Haze program, and was not a BART requirement. Nevertheless, 

as part of an ongoing effort to be proactive in addressing Treasure Valley summer ozone 

conditions, DEQ assessed the ozone impacts of this project. The NOx emission reductions 

achieved by the BART Alternative represent the greatest NOx reduction of any control measures 

that DEQ has evaluated to date, and may help to avoid non-attainment designation over the next 

few years (see the “Additional Environmental Benefits in Reducing Ozone” section in 

Appendix B to the Statement of Basis for additional discussion). 
 T2-2009.0105 Project 60867 Page 3 

Similarly, any change in plant efficiency resulting from this project would also be incidental. It 

may be noted that an application for permit modification will be required if this project results in 

a significant increase in emissions in accordance with IDAPA 58.01.01.200-228. 

Comment 2: Why will it take until 2016 to implement this project? (Quignon) 

Response: The Regional Haze program allows five years to install and operate Best Available Retrofit 

Technologies (BART). In accordance with 40 CFR 51.308(e)(1)(iv) and IDAPA 58.01.01.668.04: 

Each source subject to BART shall be required to install and operate BART as 

expeditiously as practicable, but in no event later than 5 years after approval of 

the implementation plan revision. 

This schedule includes time for federal BART approval and incorporation into the Regional Haze 

State Implementation Plan (RH SIP), and time necessary to install BART controls. 

Comment 3: Can you absolutely prove that the pollutants from TASCO are impacting Hells Canyon? 

(Johnson) 

Response: DEQ has determined that the Amalgamated Sugar Company’s (TASCO) Riley Boiler has caused 

significant contribution to haze at Eagle Cap, Strawberry Mountain, and Hells Canyon areas. 

These determinations were based on modeling analyses which predicted elevated haze impacts on 

days when elevated impacts were also measured in these areas, and when upper level transport 

winds were flowing from the Nampa area toward these areas. Such conditions occurred during 

wintertime stagnant air periods. In addition, the patterns of fine particle chemical composition 

measured at these wilderness areas closely parallel the patterns expected from the chemical 

composition of emissions from the Riley Boiler at the Nampa Factory when combined with the 

other emission sources in the Nampa-Boise area. 

In the modeling analyses, DEQ utilized modeling approaches which have been used nationwide 

and developed by several federal agencies, including the EPA, National Park Service, and U.S. 

Forest Service. The analyses used appropriate inputs developed jointly by modeling experts at the 

Idaho DEQ, EPA Region 10, Washington Department of Ecology, and Oregon DEQ. The 

modeling system used has undergone extensive testing by its developer and the EPA, and is 

identified in Appendix W to 40 CFR Part 51, the Guideline on Air Quality Modeling, as the 

recommended model for long-range transport based on validation studies in which it was 

compared to measured values. 

In summary, the measurements and modeling methods which demonstrate that emissions from 

the TASCO Nampa Factory are impacting Hells Canyon are accepted as the best science 

available by scientists, agencies, and the regulated community within our region and nationwide. 

As a result, these methods were selected by EPA and utilized by DEQ to implement Regional 

Haze program requirements. 

Comment 4: Does the BART Alternative result in a greater reduction in haze at the affected Class I areas 

as compared with the EPA-approved BART determination for the Riley Boiler? 

(Forsgren, USFS) 

Response: During and subsequent to issuance of the initial BART Tier II operating permit and EPA partial 

approval of the Regional Haze SIP, substantive comments and information were provided by 

TASCO which supported the position that certain control technologies would not be feasible to 

implement at the Nampa Factory, and that reconsideration of the NOx BART determination was 

warranted. Specifically, selective catalytic reduction (SCR) and over-fired air (OFA) technologies 

were determined to be technically infeasible in the revised BART determinations (Step 2 in the 

top-down BART determination; see Tables 4 and 5 of the Statement of Basis). 

DEQ believes it is therefore inappropriate to compare the visibility impacts of the revised BART 

determination to the initial BART NOx determination (which included infeasible control 

technologies), and that such comparison is not required by the Regional Haze program. 
 T2-2009.0105 Project 60867 Page 4 

Comment 5: What are the regulatory hurdles and policy implications that need to be addressed when 

including the non-BART units (i.e., the B&W boilers and pulp driers) in an alternative to 

BART determination? (Forsgren, USFS) 

Response: DEQ believes that inclusion of non-BART emission units in the evaluation of the BART 

Alternative does not require new regulatory interpretations nor introduce new policy implications. 

DEQ agrees with the commenter that once a source-by-source BART determination has been 

made for a BART-subject unit, emission reductions from other sources may then be considered as 

part of a BART Alternative. 

Non-BART units were included only with respect to the BART Alternative analysis and 

determination, and included only those units participating in the proposed alternative. 

Specifically, the “BART Alternative” scenario included the three pulp dryers (for which 

shutdown was proposed), the B&W Boilers (for which installation of Low NOx Burners was 

proposed), and the Riley Boiler (the BART-subject unit). 

In accordance with 40 CFR 51.308(e)(2) and IDAPA 58.01.01.668.06, DEQ may approve: 

...an alternative measure rather than to require sources subject to BART to 

install, operate, and maintain BART. Such...alternative measure must achieve 

greater reasonable progress than would be achieved through the installation and 

operation of BART. 

For the unique circumstances of this project, DEQ chose not to adopt the SO2 emission control 

limits indicated by the BART analyses for SO2 emissions, but instead adopted BART Alternative 

NOx emission limits for the B&W Boilers and shutdown requirements for the pulp dryers. These 

combined measures were predicted to result in greater projected emission reductions and in 

greater visibility improvement. 

In accordance with 40 CFR 51.308(e)(3) and as provided in the BART Guidelines (Appendix Y 

to 40 CFR 51), the BART Alternative meets the “better-than-BART test”: 

If the distribution of emissions is significantly different, the State must conduct 

dispersion modeling to determine differences in visibility between BART and the 

trading program for each impacted Class I area, for the worst and best 20 

percent of days. The modeling would demonstrate “greater reasonable progress” 

if both of the following two criteria are met: 

(i) Visibility does not decline in any Class I area, and 

(ii) There is an overall improvement in visibility, determined by comparing 

the average differences between BART and the alternative over all affected 

Class I areas. 

Because the distribution of emissions could be construed to be “significantly” different in the 

“BART Alternative” scenario than in the “BART” scenario (in terms of trading SO2 emission 

reductions for NOx emission reductions), dispersion modeling was conducted to demonstrate that 

the BART Alternative will not result in a decline in visibility in any Class I area and will result in 

an overall improvement in visibility. 

The “BART Alternative” scenario did not result in a decline in visibility at any Class I area, and 

on the balance resulted in greater improvement than the “BART” scenario across the seven 

Class I areas evaluated (see Table 9 in the Statement of Basis). The site-specific technical 

demonstration relied on both speciation and dispersion modeling to demonstrate that the net air 

quality benefits of the BART alternative will result in greater reasonable progress. 
 T2-2009.0105 Project 60867 Page 5 

Table 1 GREATER REASONABLE PROGRESS DETERMINATION (a)

Reasonable Progress Criteria Benchmark BART 

BART 

Alternative 

“Better-than-Baseline” 

Improvement 

“Better-than-BART”

Improvement 

Visibility-Impairing Emissions (PM10 + NOx + SO2 ) – Rate in lb/hr Reductions in lb/hr 

BART Alternative Emission Units 1,929.2 1,277.6 1,276.6 + 1.0 (b)

Class I Area Visibility – Number of Days Above 0.5 Δdv Number of Days Improved to Less Than 0.5 Δdv 

Eagle Cap 195 149 126 + 69 (c)

+ 41 (d)

Craters of the Moon 10 4 3 + 7 (c)

Hells Canyon 129 87 80 + 49 (c)

Jarbidge 8 5 5 + 3 (c)

Sawtooth 18 6 6 + 12 (c)

Selway-Bitterroot 15 3 4 + 11 (c)

Strawberry Mountain 80 62 51 + 29 (c)

Result No degradation in any 

Class I area (c)

Overall improvement 

in visibility and 

Greater Reasonable 

Progress (b,d)

(a) This table contains a summary of results from the Statement of Basis (see Tables 6, 7, and 9). 

(b) BART Alternative results in greater emission reductions as described under 40 CFR 51.308(e)(3). 

(c) For the BART Alternative, visibility does not decline in any Class I area, meeting the criteria in 40 CFR 51.308(e)(3)(i). 

(d) For the BART Alternative, there is an overall improvement in visibility, determined by comparing the average differences 

between BART and the alternative over all affected Class I areas, meeting the criteria in 40 CFR 51.308(e)(3)(ii). 

As summarized in Table 1, the BART Alternative satisfies the “Better-than-BART” test criteria in 

40 CFR 51.308(e)(3); the BART Alternative results in greater emission reductions, does not 

result in a decline in visibility in any Class I area, and results in an overall improvement in 

visibility when the average differences between BART and the BART alternative over all 

affected Class I areas are compared. 

These demonstrations fulfill 40 CFR 51.308(e)(2) and (e)(3), and IDAPA 58.01.01.668.06, and 

the overarching statutory requirement in 42 U.S.C. § 7491(b)(2) that States make reasonable 

progress toward the national visibility goal. 

Comment 6: Citing an EPA letter to the Colorado Air Pollution Control Division,1

 the use of an 

Alternative-to-BART approach within a source's fence line may not be appropriate. 

Although 40 CFR 51.308(e)(2) is silent on the applicability of an Alternative-to-BART 

occurring within a fenceline, it could be reasonably construed that Section V of the BART 

guidelines would govern such a situation. (Silva, FWS) 

Response: In the letter and guidelines cited, concern is raised that although “averaging across BART 

emission units within a source’s fenceline” was contemplated in making BART determinations, 

that this was not explicitly characterized as a BART alternative. Citing Section V: 

You should consider allowing sources to "average" emissions across any set of 

BART-eligible emission units within a fenceline, so long as the emission 

reductions from each pollutant being controlled for BART would be equal to 

those reductions that would be obtained by simply controlling each of the 

BART-eligible units that constitute BART-eligible source. 

 

1 Letter from EPA Region 8 to Paul Tourangeau, Colorado Department of Public Health and Environment, “EPA Region 8 Comments on Draft BART 

Analyses,” Cynthia Cody, EPA, February 16, 2007. 
 T2-2009.0105 Project 60867 Page 6 

DEQ believes it is important to distinguish that this guidance is directed toward the BART 

determination process, and is not controlling of BART alternative measures. While EPA does not 

characterize an inside-the-fenceline approach as a BART alternative, such an approach was also 

not expressly excluded from consideration. 

As described in the response to Comment 5 and in accordance with the requirements of 

40 CFR 51.308(e)(2) and (e)(3) and IDAPA 58.01.01.668.06, DEQ has the discretion to adopt 

implementation plan provisions other than those provided by BART analyses in situations where 

it has reasonably concluded that more “reasonable progress” will thereby be attained. Beyond 

meeting these requirements, it may also be argued that the trading of emission reductions 

inside-the-fenceline in accordance with 40 CFR 51.308(e)(3) is more narrow in focus than the 

implementation of a cap-and-trade program allowable under 40 CFR 51.308(e)(4), which 

implicitly allows trading of emissions beyond the fenceline and across different source categories. 

Furthermore, there are other notable differences between the TASCO BART Alternative and 

Public Service Company’s (PSCo) BART alternatives for the Hayden 1 and 2 and Comanche 1 

and 2 facilities: 

• The TASCO BART Alternative meets the recommended criteria under 40 CFR 51.308(e)(3) 

for demonstrating that the alternative achieves greater reasonable progress (see response to 

Comment 5), as compared to the use of a “weight-of-evidence” approach under 40 CFR 

51.308(e)(2)(i)(E) in PSCo BART alternative demonstrations. 

• The TASCO BART uses a conventional top-down and case-by-case approach to determining 

BART, as compared to the use of presumptive emission limits for 750 MW coal-fired power 

plants in PSCo BART determinations. 

• The TASCO BART Alternative emission limits were specified on a basis consistent with the 

maximum hourly emission rates used in the BART analyses, as compared to limits specified 

with a longer (less stringent) averaging period in PSCo BART Alternative demonstrations. 

• The TASCO BART and BART Alternative were compared using both emission reductions 

and modeling analyses to demonstrate greater visibility improvement, as compared to the use 

of emission reductions alone in PSCo BART Alternative determinations. 

The purpose of the BART analyses was to identify existing, older stationary emission sources that 

contribute to haze at Class I areas and could be retrofit to reduce emissions. The B&W Boilers 

participating in the BART Alternative share similar characteristics with the Riley Boiler – these 

units predate the 1977 Clean Air Act Amendments, derive from the same emission source 

category, and share in purpose and function at the Nampa Factory. Boiler steam load is presently 

distributed across all three of the boilers at the Nampa Factory according to process needs, and 

requiring BART controls on a single boiler could preferentially shift load distribution and shift 

emissions toward the uncontrolled (B&W) non-BART boilers under certain boiler operating 

scenarios. Beyond meeting Regional Haze program requirements, these characteristics further 

support inclusion of non-BART units and use of an inside-the-fenceline approach in the BART 

Alternative in order to achieve greater reasonable progress. 

Comment 7: Can credit for emission reductions achieved by the shutdown of the pulp driers be applied 

under the Regional Haze Rule if these units were shutdown as a result of another regulatory 

action under the Clean Air Act (i.e., compliance with the NAAQS for PM10)? Discussion in 

Attachment #2 to the application states that shutdown was required to support the PM10

NAAQS Maintenance Plan for Ada County. (Forsgren, USFS)(Silva, FWS) 

Response: In approving the proposed BART Alternative, DEQ credited TASCO with emissions reductions 

resulting from shutdown of all three pulp dryers - the North Pulp Dryer, the Center Pulp Dryer, 

and the South Pulp Dryer. DEQ believes it was reasonable to credit TASCO with these emission 

reductions. 
 T2-2009.0105 Project 60867 Page 7 

The Center Pulp Dryer (S-D2) and the North Pulp Dryer (S-D3) were required to be shut down by 

September 30, 2007 as part of a compliance schedule,2

 which included conditions established to 

ensure that emissions (and modeled impacts) will not cause or significantly contribute to a 

violation of PM10 National Air Quality Standards (NAAQS) in areas surrounding the Nampa 

Factory and as part of the Northern Ada County PM10 SIP Maintenance Plan and Redesignation 

Request. An enforceable requirement to shut down the remaining coal-fired pulp dryer, the South 

Pulp Dryer (S-D1), was included as BART Alternative requirement in the proposed permit 

(Permit Condition 4.1). 

In accordance with 40 CFR 51.308(e)(2)(iv), a BART alternative measure must achieve greater 

reasonable progress than would be achieved through the installation and operation of BART, and 

DEQ must submit an implementation plan including: 

A demonstration that the emission reductions resulting from the emissions 

trading program or other alternative measure will be surplus to those reductions 

resulting from measures adopted to meet requirements of the CAA as of the 

baseline date of the SIP. 

The five-year average of emissions (statewide baseline emission inventory) over years 2000 

through 2004 established the baseline against which reasonable progress will be measured (see 

the Regional Haze SIP, cited in the “Background” section above, for additional information). 

Similarly, emissions over years 2003 through 2005 (Nampa Factory BART inventories) were 

used to determine the baseline visibility modeling scenario against which TASCO BART 

visibility improvement was measured (“Alternative Benchmark” scenario; see Table 8 of the 

Statement of Basis). Thus the emission reductions associated with shutdown of the pulp dryers 

were not included nor accounted for within these baseline scenarios (i.e., the baseline modeling 

analyses included full operation of the pulp dryers). 

Because the pulp dryer emission reductions were implemented following the baseline period, 

DEQ believes that including the emission reductions from shutdown of the pulp dryers as part of 

the BART Alternative is acceptable under the rule. 

Comment 8: The proposed BART Alternative does not address each pollutant because there will be no 

control of SO2 at the BART-eligible Riley Boiler. Although under the proposed Alternative 

scenario SO2 will not be controlled, limits should still be established to ensure compliance 

with the 0.75% sulfur content used in the emissions used in the modeling, rather than 

relying upon the 1.0% limit under IDAPA. (Silva, FWS) 

Response: As described in the response to Comment 5 and in accordance with the requirements of 

40 CFR 51.308(e)(2) and (e)(3) and IDAPA 58.01.01.668.06, DEQ has the discretion to adopt 

implementation plan provisions other than those provided by BART analyses in situations where 

it has reasonably concluded that more “reasonable progress” will thereby be attained. 

EPA guidance further supports that “inter-pollutant trading” was contemplated and is supported 

when greater reasonable progress will be attained: 3

...a State could demonstrate that a trading program that addresses one or two 

visibility-impairing pollutants under an alternative program would provide 

greater reasonable progress than would case-by-case BART applied to all 

visibility-impairing pollutants. 

The actual average coal sulfur content level over the baseline years (2003-2005) was used in the 

BART analyses and modeling in accordance with BART protocol, which was achieved by 

TASCO compliance with the 1.0% coal sulfur content limit required by IDAPA 58.01.01.725. 

 

2 Required in Permit Condition 13.8 of Tier II Operating Permit No. T2-050021, final, revised March 8, 2006. 3 Regional Haze Regulations; Revisions to Provisions Governing Alternative to Source-Specific Best Available Retrofit Technology (BART) 

Determinations, 71 FR 60612-60634, Final, October 13, 2006. See also response to Regional Progress Question #5, “Additional Regional Haze 

Questions,” EPA Q&A document, revised September 27, 2006. 
 T2-2009.0105 Project 60867 Page 8 

Because actual emissions have been effectively regulated by compliance with this sulfur content 

limit, and after a review of TASCO’s compliance history, DEQ does not believe a more stringent 

limit is supported at this time. 

Existing sulfur content limits corresponding to the baseline case (1% sulfur content by weight) 

and supporting monitoring requirements were relied upon from TASCO’s Tier I operating permit4

to address concerns regarding the inclusion of an enforceable emission limit. 

Comment 9: Should 90% control efficiency be applied to Spray Dry FGD in lieu of 80%? Would the 

conclusion of greater reasonable progress be reached in this instance? Development of the 

Spray Dry FGD costs using the EPA Control Cost Manual should be available for public 

review. (Silva, FWS) 

Response: The initial BART determination for SO2 approved by EPA has not been revised as a result of this 

permitting action, and therefore DEQ believes revisiting the elements and results of the initial 

BART SO2 determination is not supported. 

As provided in the Statement of Basis for Tier II Operating Permit No. T2-2009.0105, issued 

September 7, 2010, due to concerns related to protecting the integrity and performance of the 

baghouse (BART) control device, a conservative adiabatic approach temperature of 40◦

F above 

the adiabatic saturation temperature was assumed for the Spray Dry Flue Gas Desulfurization 

(Spray Dry FGD) control device. This corresponded to estimated performance of 80% removal 

efficiency, which fell within the range of 80-90% control efficiencies typically cited for Spray 

Dry FGD.5

 Cost estimates were also reviewed in the initial BART determination. 

Comment 10: Cost justification in terms of cost per deciview of visibility improvement/cumulative 

visibility impact should be considered. (Silva, FWS) 

Response: Consistent with the response to Comment 9, DEQ’s regulatory approach to making the BART 

determinations is not being reconsidered at this time, and the ranking methodology used in 

comparing control technologies has not been altered since approval of the Regional Haze SIP. 

Introducing a cost-per-deciview metric (in lieu of or in addition to ranking by dollars-per-ton) at 

this time would be inconsistent with the methodology used in the initial BART determinations. 

Use of dollars-per-ton of emission reduction in ranking control technologies is an accepted 

convention and recommended by EPA in Appendix Y to 40 CFR 51, and it has been used 

extensively in the Regional Haze and Prevention of Significant Deterioration programs under the 

Clean Air Act (CAA). Use of dollars-per-deciview is a relatively new approach without 

established guidance, and it has been used only in a limited number of determinations. 

Comment 11: Additional clarification is recommended to assist the public in further understanding the 

complexities of regional haze predictions. (DeLorey, TASCO) 

Response: DEQ does not interpret the comments provided by TASCO as requesting or supporting any 

change to the BART analyses or to the BART determinations as proposed. Information 

concerning visibility monitoring and measurement, the modeling protocol, and the approach 

toward evaluating BART emissions and impacts is addressed within the Statement of Basis and 

within the references cited in the “Background” section (see above). 

Without endorsement, the comments and information provided by TASCO (and all other 

commenters) have been included in Appendix A for the record and for public review. 

 

4 Permit Conditions 2.14 and 2.15 of Tier I Operating Permit No. T1-050020, final, revised May 23, 2006. See additional discussion provided concerning 

Permit Conditions 3.11 and 3.13 in the “Permit Conditions Review” section of the Statement of Basis. 5 Air Pollution Control Technology Fact Sheet, EPA-452/F-03-034. 
 T2-2009.0105 Project 60867 Page 9 

APPENDIX A 

PUBLIC COMMENTS RECEIVED 
 T2-2009.0105 Project 60867 Page 10 

Name: Dennis Freeman 

Email Address: dlfreeman50@gmail.com 

Sent: Tuesday, November 01, 2011 5:48 AM 

To: Martin Bauer 

Subject: Amalgamated Sugar Plant – Nampa 

In today’s issue of Idaho Press Tribune, $8 million in upgrades were announced for air quality improvements. 

Will any of the improvements address the obnoxious odor that residents for miles around have to endure from 

October thru March during the processing period? 

Please let me know what is being done to address this issue. 

Name: Bonnie Quignon 

Email Address: bfquignon@hotmail.com 

Affiliation: None

Sent: Tuesday, November 01, 2011 2:05 PM 

To: Tessa Stevens 

Subject: Public Comment 

I think this is a very positive step, but why will it take till 2016 to accomplish it? It could be done in their off 

season and be finished in one year. Those around them who suffer with their pollution would thank you. 








Comments of the US Fish & Wildlife Service (FWS) Regarding an 

“Alternative-to-BART” Proposal to Meet Best Available Retrofit 

Technology (BART) for The Amalgamated Sugar Company LLC 

(TASCO) Nampa Factory as Proposed by the Idaho Department of 

Environmental Quality (IDEQ)

 

The IDEQ determined that the Riley Boiler at the TASCO Nampa Factory is subject to 

BART under the EPA Guidelines for Best Available Retrofit Technology 

Determinations1

 and IDEQ provided an original BART determination on July 17, 2009. 

TASCO objected to the original BART determination and pursued an “Alternative-toBART” in negotiations with the IDEQ. Subsequently, IDEQ provided to the FWS, 

“Proposed Revision to ‘Section 10.5 TASCO BART Determination’ of the RH SIP” 

(Proposed Revision), along with an Air Quality Permit Statement of Basis for the Tier II 

Operating Permit No. T2-2009.0105 Project 60867 and “BART Alternative Visibility 

Modeling for the Riley Boiler at TASCO – Nampa Factory” which propose an 

Alternative-to-BART under 40 CFR Part 51.308(e)(2). The FWS has several questions 

and comments relating to IDEQ’s proposed Alternative to BART determination for the 

TASCO Nampa Factory. 

The FWS does not believe that IDEQ’s approach should or can be evaluated as an 

Alternative-to-BART; however, such a determination will ultimately be made by EPA, 

Region X. In a letter dated February 16, 2007, EPA, Region VIII communicated to the 

Colorado Air Pollution Control Division that regarding Public Service Company’s 

Hayden 1 and 2 and Comanche 1 and 2 facilities, use of an Alternative-to-BART 

approach within a source’s fence line may not be appropriate. The letter discusses that 

while EPA’s BART guidelines2 contemplate that BART determinations may include 

averaging across BART emissions units within a source’s fence line, EPA does not 

characterize this as a BART alternative. Also, Section V of the BART guidelines 

discusses averaging emissions across any set of BART-eligible emission units within a 

fence line for each pollutant. The proposed Alternative-to-BART does not address each 

pollutant because there will be no control of SO2 at the BART-eligible Riley boiler. 

Further, Section V seems to contemplate averaging across only BART-eligible emission 

units without including non-BART-eligible emission units. Since, 40 CFR Part 

51.308(e)(2) is silent on the applicability of an Alternative-to-BART occurring within a 

fence line, it could be reasonably construed that Section V of the BART guidelines would 

govern such a situation. 

This paragraph relates to the inclusion of emissions reduction credits from the permanent 

shutdown of three coal-fired pulp dryers as part of the Alternative-to-BART 

demonstration. For purposes of Best Available Control Technology (BACT) under the 

Prevention of Significant Deterioration (PSD) Program emission credits from the 

shutdown of emission units cannot be used as credit to meet BACT. We are not aware of 

any definitive language under the BART program that allows or disallows such shutdown 

 

1

 See “Guidelines for BART Determinations Under the Regional Haze Rule.” 40 CFR Part 51, Appendix Y. 

2

 Ibid., Section V – first paragraph. 
2 

credits for purposes of meeting BART, so it remains an open question for EPA, Region X 

to address in the case of the TASCO Alternative-to-BART proposal. In 40 CFR Part 

51.308(e)(2)(iv) it is stated that, “. . . emission reductions resulting from the emissions 

trading program or other alternative measure will be surplus to those reductions resulting 

from measures adopted to meet requirements of the CAA as of the baseline date of the 

SIP.” Page 33 in Attachment #2 of the Proposed Revision states that, “. . . shut down of 

the coal-fired pulp dryers was required to support the PM10 NAAQS Maintenance Plan 

for Ada County . . .” This issue bears further scrutiny before the Alternative-to-BART 

proposal is approved. 

The underlying requirement for use of an Alternative-to-BART rather than BART for the 

Riley boiler is that the Alternative achieves greater reasonable progress toward meeting 

the long term strategy for visibility protection. Table 10-13 in Attachment #1 of the 

Proposed Revision develops the greater reasonable progress justification for the Eagle 

Cap Wilderness area using Spray Dryer Flue Gas Desulfurization (FGD) for SO2 control 

as the SO2 BART control (line 2 on the table). In Table 6 of the Statement of Basis for 

the Tier II Operating Permit, IDEQ presents an 80% emission reduction capability of 

Spray Dryer FGD for SO2 control (522.3 lb/hr benchmark emissions vs. 104.0 lb/hr 

controlled emissions). Spray Dryer FGD can routinely be assumed to attain 90% control 

efficiency. Some examples for plants using Lime Spray Dryer FGD technology on low 

sulfur coal are as follows: Newmont Nevada - 93.1%, LS Power – White Pine - 89.8%, 

LS Power – High Plains - 93.4%, Two Elk Expansion - 89.9%, Basin Electric – Dry Fork 

- 92.9%, and AES-Colorado - 90.7%. If a modeling input of 90% SO2 control was used 

for the BART case instead of 80%, the outcome for greater reasonable progress for the 

Alternative method would be more muted and possibly not show greater reasonable 

progress. Since it seems that the 80% control assumption was used for the greater 

reasonable progress demonstration, then the BART control level was understated, leaving 

a lower hurdle to demonstrate greater reasonable progress. The modeling should be 

performed using a 90% control efficiency assumption for the BART case. 

It should be noted that the FWS still considers the Spray Dryer FGD SO2 control 

alternative to be viable for BART. The IDEQ agreed with a $2,663 per ton of SO2

control cost for this alternative, including the costs of non-air quality environmental 

impacts. This value could be decreased to $2,367 if the control efficiency were presented 

as 90%, rather than 80% in the cost development. A control efficiency of 90% for Spray 

Dryer FGD is certainly attainable as shown above. Either of the above costs should be 

considered as being reasonable for BART. It was indicated that the EPA Control Cost 

Manual was used to develop the Spray Dryer FGD costs. This analysis should be 

available in the record for third-party reviewers. 

The following paragraph is moot if IDEQ proceeds with the Alternative-toBART. However, should the discussion ever revert back to using Spray Dryer 

FGD as BART for SO2 control, cost justification in terms of cost per deciview of 

visibility improvement should use the concept presented below. The concept of 

cumulative visibility impact reductions at all seven affected Class I areas should 

be considered. Such considerations have been employed in BART determinations 
3 

by Alaska, Oregon and Wyoming. Earlier the IDEQ made judgments on cost per 

deciview based on only the most impacted Class I area, Eagle Cap Wilderness 

Area. We continue to believe that it is appropriate to consider both the degree of 

visibility improvement in a given Class I area as well as the cumulative effects of 

improving visibility across all of the Class I areas affected. It simply does not 

make sense to use the same metric to evaluate the effects of reducing emissions 

from a BART source that impacts only one Class I area as for a BART source that 

impacts multiple Class I areas. And, it does not make sense to evaluate impacts at 

one Class I area, while ignoring others that are similarly significantly impaired. If 

emissions from TASCO are reduced, the benefits will be spread well beyond only 

the Eagle Cap Wilderness Area to the other six affected Class I areas. 

In Section 5 of Proposed Revision - Attachment #3, “Redlined Version of the 

Revised BART Tier II Operating Permit”, no SO2 emission limits are provided for 

the Riley Boiler or the two Babcock and Wilcox Boilers. Even though under the 

proposed Alternative scenario they will not be controlled, there should be SO2

emission limits for these units (e.g., 522 lb/hour for the Riley Boiler and 435 lb/hr 

for the two B&W boilers). Such emission limits could prevent a future TASCO 

transition to a coal that has higher sulfur content than the current average being 

used (0.75% sulfur) up to the current state limit of 1.0% sulfur. In such a case 

actual visibility improvement would not likely meet the performance provided in 

the Alternative-to-BART. A similar situation could exist if the two B&W boilers 

undergo a BACT analysis for expansion in the future without considering the 

BART premises being instituted at this time.