# Attachment H6 BART Analyses Solutia, Inc International Paper- Courtland Mill

### Best Available Retrofit Technology Analysis Solutia, Inc.

712-0010 On December 19, 2006, Solutia, Inc. locate d in Decatur, Alabama submitted a Best Available Retrofit Technology (BART) analysis . Revised analyses containing additional information were received on Januar y 25, 2007, March 22, 2007, and May 7, 2007. Solutia identified its BART-eligible emission un its to include three coal-fired boilers (No. 5, No. 6, and No. 7) and two coking units (Coke r Boilers No. 1 and No. 2). The results of the BART modeling analysis for these units in dicated the predicted visibility impacts at the Sipsey Wilderness Area, a Class I Area, were above 0.5 deciviews (dV). Therefore, Solutia submitted an analysis of alternative c ontrol options for its BART-eligible units for the following pollutants: particulat e matter (PM), sulfur dioxide (SO 2 ), and nitrogen oxides (NOx).

The case-by-case engineering analysis takes into account the following six factors in making the determination of any BART controls and limitations:

1) Available retrofit control options 2) Any pollution control equipmen t in use at the source 3) The costs of compliance with control options 4) The remaining useful life of the facility 5) The energy and non-air quality environm ental impacts of control options 6) The visibility impacts analysisExisting Equipment Currently, each BART-eligible unit (i.e. three boilers and two coking units) has electrostatic precipitators (ESPs) for PM control. For Boiler No. 7, Solutia has installed the ROFA (rotating opposed fired air) system to reduce NOx formation. Although the basis for the installation of the ROFA system for Boiler No.7 was the Boiler MACT, the system has been installed and was considered as existing equipment in regards to this case-by-case BART analysis.

Particulate Matter Emissions Solutia indicated that the primary available control options for PM would include ESPs, baghouses, wet scrubbers, cyclones, and side st ream separators. As previously stated, Solutia’s BART-eligible boilers and coking units are each equipped with an ESP. For Boilers 5&6, stack tests have shown an overall PM control efficiency for the ESPs to be 98.8%. For Boiler 7, the PM control efficiency has been estimated from stack tests as 99%. Although the coking boilers have not been the tested, the PM control efficiency from the ESPs has been estimated at 96%.

Typically, the collection efficiency of a baghouse can be as high as 99.9%. The other control technologies (w et scrubbers, cyclones, etc.) have lower collection efficiencies than baghouses and ESPs. Solutia evaluated the option of adding a baghouse to each of the boilers and coking units following the existing ESPs. BART Unit Control Option Tons Removed Cost/Ton Removed 98 th Percentile 24-Hr Visibility Improvement Boiler 5 Baghouse 21.5 $79,995 0.21 1 Boiler 6 Baghouse 44.96 $38,316 0.21Boiler 7 Baghouse 409.57 $5462 0.52 Coker 1 Baghouse 120 $13,709 0.19 Coker 2 Baghouse 120 $13,709 0.19 1-Boiler 5 is the same type of boiler as Boiler 6 but with a lower rated capacity. Modeling was not conducted for Boiler 5 but was assumed to have the same results as Boiler 6.

Nitrogen Oxides (NOx) Solutia indicated that the primary available control options for NOx would be categorized as combustion controls and post-combustion controls. The available combustion control options would include low excess air, burners out of service, biased burner firing, overfired air, low NOx burners, and reburn. Available post-combus tion control options would include selective non-catal ytic reduction (SNCR) and se lective cataly tic reduction (SCR). As previously stated, Solutia has in stalled a ROFA system on its No. 7 Boiler. The manufacture has guaranteed a NOx reduction of 48% with the system.

For each unit, Solutia has indicated that the available and technically feasible control options would include 1) the ROFA system with a SNCR for each un it and 2) SCR. The SNCR (called Rotamix) would provide an a dditional 30% reduction of NOx as compared to the ROFA system alone. The typical NOx control efficiency from the SCR is 95%. The evaluation of NOx controls for each BART -eligible unit is shown in the table below:

BART Unit Control Option Tons Removed Cost/Ton Removed 98 th Percentile 24-Hr Visibility Improvement Boiler 5 ROFA with SNCR(Rotamix) 52.84 $15,529 0 1
Boiler 5 SCR 86.54 $8,675 0 1 Boiler 6 ROFA with SNCR(Rotamix) 57.28 $18,091 0 Boiler 6 SCR 93.81 $5,461 0 Boiler 7 SNCR(Rotamix) 2 217.35 $4,118 0Boiler 7 SCR 2 654.84 $1,986 0 Coker 1 ROFA with SNCR(Rotamix) 265 $4,510 0 Coker 1 SCR 435 $2,607 0 Coker 2 ROFA with SNCR(Rotamix) 265 $4,510 0 Coker 2 SCR 435 $2,607 0 1-Boiler 5 is the same type of boiler as Boiler 6 but with a lower rated capacity. Modeling was not conducted for Boiler 5 but was assumed to have the same results as Boiler 6. 2-The cost, emissions, and improvements are based on the addition of the SNCR/SCR to the ROFA system, which is considered as existing control for Boiler 7 for this analysis.

Sulfur Dioxides (SO 2 ) Solutia indicated that the primar y available control options for SO 2 would include the utilization of lower sulfur coals, physical coal cleani ng, and post-combustion flue gas desulfurization (which would include sorbent injection or wet scrubbers). Since physical coal cleaning is not effective in removing organic sulfur and creates a loss in the heating content of the coal, this option was not considered.

Currently, Boiler No. 7 is already required to utilize low sulfur coal. Therefore, the utilization of lower sulfur coal would only provide a reduction of 7%. The use of low sulfur coal (1.4 lbs SO 2 /MMBTU) in Boiler 5 and 6 w ould provide a reduction of approximately 43% and a reduction of approxima tely 16% for the cokers. In combination with the ROFA system, Solutia has a manufac turer guarantee that th e use of a furnace sorbent injection (FSI) system would reduce SO 2 by as much as 60% in Boiler No. 7. The FSI system would inject a calc ium-based sorbent such as lim estone into the upper furnace region. The evaluation of SO 2 controls for each BART-eligib le unit is shown in the table below:BART Unit Control Option Tons Removed Cost/Ton Removed 98 th Percentile 24-Hr Visibility Improvement Boiler 5 Low Sulfur Coal 1438.88 $1065.54 0.32 1 Boiler 5 ROFA/FSI 1876.79 $663.45 0.34 1 Boiler 5 Wet Scrubber 2815.19 $1075.46 0.40 1 Boiler 6 Low Sulfur Coal 1587.72 $1065.54 0.32 Boiler 6 ROFA/FSI 2070.95 $615.80 0.34 Boiler 6 Wet Scrubber 3106.42 $977.86 0.40 Boiler 7 Low Sulfur Coal 168.09 $16,034.55 0.03 Boiler 7 ROFA/FSI 1440.8 $931.95 0.24 Boiler 7 Wet Scrubber 2161.21 $1854.90 0.36 Coker 1 Low Sulfur Coal 302.09 $8739 0.05 Coker 1 ROFA/FSI 1599.10 $1090.20 0.36 Coker 2 Low Sulfur Coal 302.09 $8739 0.05 Coker 2 ROFA/FSI 1599.10 $1090.20 0.36 Cokers Wet Scrubber 4797.30 $600.20 0.41 1-Boiler 5 is the same type of boiler as Boiler 6 but with a lower rated capacity. Modeling was not conducted for Boiler 5 but was assumed to have the same results as Boiler 6.

Cost of Compliance In reviewing the cost of controls based on emissions removed, Solutia indicated that the additional controls for partic ulate and NOx emissions would not be cost effective. The current particulate controls (ESPs) achieve removal efficiencies between 96%-99% and an adequately control of the particulate em issions. The additional NOx controls indicated relatively small to no reduction in visi bility impacts for the reported costs (see NOx
section ).

The costs for additional SO 2 controls appear to be more cost effective and provide some visibility improvement. Solutia has indicated th at the cost of installation and operation of the FSI system or wet scrubbers would severely impact the facility’s sustainability and viability.For both of the coking units, Solutia has indica ted that the addition of any controls would negate the viability of the coking units. The requirement of the additional controls would result in a net loss and thus require the units to be shutdown.

Non-Air Quality Environmental Impacts
Solutia has indicated that the additional SO 2 controls would generate additional waste. Solutia estimated that the FSI system would generated an additional 14,000 tons of fly ash per boiler and the addition of the wet scrubber would generate 20 tons/day of sludge.

Proposed BART Limitations
NO x

• Solutia has proposed no add on controls fo r Boiler 5, Boiler 6, and the Cokers for the control of NOx emissions.

• Boiler 7 would be required to meet an emission limit of 0.36 lb NOx/MMBTU with the installation of a ROFA system or a comparable technology.

SO 2

• Solutia has proposed to limit Boilers 5 and 6 to burning coal with a sulfur content resulting in SO 2 emissions less than 1.40 lbs/MMBTU.

• Boiler 7 would be required to meet a limitation of 0.47 lb SO 2 /MMBTU with the installation of the FSI system or a comparable technology.

• Solutia has proposed no add on controls for the Cokers.PM 10

• The existing electrostatic precipitators will be utilized to control PM emissions for each BART unit (Boiler 5-7, Cokers 1-2).

The Table below presents the summarized BART emission limits for Solutia.
Solutia BART Emission Limitations
Emission Limitations Emission Unit NO x SO 2 PM 10

Boiler 5 101.22 lb/hr 1 1.40 lb/MMbtu & 406 lb/hr 0.12 lb/MMbtu & 34.8 lb/hr

Boiler 6 109.72 lb/hr 1 1.40 lb/MMbtu & 448 lb/hr 0.12 lb/MMbtu & 38.4 lb/hr

Boiler 7 0.36 lb/MMbtu & 193 lb/hr 0.47 lb/MMbtu & 252 lb/hr 0.10 lb/MMbtu & 64.33 lb/hr

Coker 1 104.43 lb/hr 1 3.57 lb/MMbtu & 1,370.1 lb/hr 0.12 lb/MMbtu

Coker 2 104.43 lb/hr 1 3.57 lb/MMbtu & 1,370.1 lb/hr 0.12 lb/MMbtu

1-NOx emission limit from base line emissions

The Department concurs with the proposed BART limitations. For Boiler 7, Solutia would be required to install a continuous emission monitor system (CEMS) for determining compliance with the SO 2 and NOx emission limitations. The limitations established under BART may be changed thro ugh the NSR (New Source Review) permitprocess which should include a visibility analysis prior to the modification.

Visibility Impact As previously stated, modeling was conducted to show the pred icted visibility impact on the closest Class I Area (Sipsey Wilderness Area). From the chosen options, an improvement of 0.32 dV is expected from each of Boiler 5 and 6, and an improvement of 0.24 dV for Boiler 7 from SO 2 controls.

Recommendation The proposed limitations appear to meet th e requirements for BART. Therefore, I recommend that the attached Air Permits be issued.

_________________________ Adrienne Newton Chemical Branch Air Division September 13, 2007 DateBest Available Retrofit Technology Analysis IP Courtland

707-0001 IP Courtland submitted a Best Available Retrofit Technology Analysis (BART) on October 10, 2006. A revised analysis containi ng additional information was received on June 1, 2007. IP submitted th is analysis since the BART exemption modeling showed that the mill contributed to visibility impairment to Clas s I areas within 300 Km of the mill. Since sources at the mill contributed to a 24hr visibility change of greater that 0.5 deciview (dV) visibility cha nge over natural conditions in the Sipsey Wilderness Area the mill had to conduct a Case-by-Case Bart Anal ysis. IP identified the BART eligible sources at the mill as the No. 1 Combinati on Boiler, No. 2 Combination Boiler, Package Boiler, No 2 Recovery Furnace, No 2 Smelt Dissolving tank, No. 1 Lime Kiln, and No. 2 Lime Kiln.

IP analyzed each BART eligible source, determ ined which controls would be feasible for these sources and ranked them according to the potential visibility improvements. IP’s Analysis determined that the No. 2 Combin ation Boiler and the No. 2 Recovery Furnace were the sources with the largest contribu tion to the mill’s visibility impacts on the Sipsey Wilderness Area. Therefore IP atte mpted to develop a control scenario around these 2 units, since control ling these 2 units would give the greatest improvement. During the development of this analysis IP determined that controlling the No. 2 Recovery would not be cost effective; ther efore, alternative me ans of reduction were evaluated. IP then evaluated the other contro l options for the other BART sources at themill and developed a control strategy for visibil ity improvement at the Courtland Mill. IP has proposed to install low NOx Burners on the No. 2 Combination Boiler and either install low NOx Burners or only operate the No. 1 Combination Boiler when one of the following emissions units are either not operati ng or in periods of start-up or shutdown: the No. 2 Combination Boiler the No. 2 Recovery Furnace, the No. 3 Combination Boiler, or the No. 3 Recovery Furnace.

IP’s Application followed EPA’s guidance by conducting the BART analysis using a top down approach which consisted of the following 5 steps.

• Identify all available re trofit control technologies

• Eliminate technically infeasible options

• Evaluate control effectivene ss of control technologies

• Evaluate impacts

o Cost of Compliance

o Energy and non-air quality environmental impacts

o Remaining useful life

• Evaluate visibility impacts

The Department has chosen to evaluate the IP submittal based on the following criteria:

• Existing air pollution cont rol technology in use

• Available retrofit co ntrol technologies

• Remaining useful life of the source

• Cost of Compliance• Energy and non-air quality environmental impacts

• The degree of visibility improvement whic h may reasonably be anticipated from the use of BART.

Background/Existing Equipment The No. 1 Combination Boiler, also known as the No.1 Power Boiler, is designed to burn bark, natural gas, and fuel oil and is operated as a swing boiler. Ba rk from the woodyard is fed to a bark bin which supplies both the No.1 and No.2 Combination Boilers. In addition, the No. 1 Combination Boiler has the capability to co mbust the dilute noncondensable gas (HVLC) stream from the pul p mill and chemical recovery areas. The No. 1 Combination Boiler is vented to a ve nturi scrubber where the gases are scrubbed with water to remove particulate matter. The Visibility Impairing Pollutants (VIP) which the No. 1 Combination Boiler emits and will require a BART analysis are SO 2 , NO x , and
PM 10 .

The No. 2 Combination Boiler, also known as the No. 2 Power Boiler, fires coal, bark, and natural gas. The primary fuel for this boiler is bark, which is supplied to the boiler by the bark handling system. The other primar y fuel for this boiler is coal. There are three coal mills associated with the N o. 2 Combination Boiler which consist of a pulverizer and a primary air fan th at is used to dry the coal a nd blow the coal in the boiler as well as provide excess air for the combustion of the coal. Each of the pulverizers provides coal to two burners, and each of the burners is equipped with a gas igniter. The No. 2 Combination Boiler also has the capability to combust the dilute non-condensablegas (HVLC) stream from the pulp mill and chemical recovery areas. The No. 2 Combination Boiler is vented to two electros tatic precipitators to remove particulate matter. The flue gas is then vented to a high pressure venturi scrubber for the removal of
SO 2 . The VIP’s which the No. 2 Combinatio n Boiler emits and will require a BART analysis are SO 2 , NO x , and PM 10 .

The Package Boiler is utilized as a back- up boiler and is fired by natural gas. The Package Boiler has no external emission control devices and the VIP’s which the Package Boiler emits and will require a BART analysis are SO 2 , NO x , and PM 10 .

The No. 2 Recovery Furnace is designed to fire black liquor, with natural gas and fuel oil as supplemental fuels. In the furnace the liquor is dried and burned. The organic portion of the liquor burns which provides heat for steam generation. The inorganic portion of the liquor is recovere d to produce cooking liquor for the digesters. The combustion gases from the furnace are vented to an electrostatic precipitator for particulate matter control. The VIP’s which the No. 2 Recovery Furnace em its and will require a BART analysis are
SO 2 , NO X , and PM 10 .

The No.2 Smelt Dissolving Tank is a recovery op eration for the No. 2 Recovery Furnace. The inorganics in the Recovery Furnace accu mulate on the furnace floor and drain into the No. 2 Smelt Dissolving Tank as molten smelt. The smelt is mixed with weak wash to form green liquor which is sent to the cau sticizing area. The No. 2 Smelt Dissolving Tank is vented through a separa te scrubber system for partic ulate matter control. TheVIP’s which the No. 2 Smelt Dissolving Tank em its and will require a BART analysis are
SO 2 and PM 10 .

Lime mud from the Causticizing Area is converted to lime in one of the three lime kilns at the facility. Lime Kilns No. 1 and No. 2 are subject to BART. Both the No. 1 and No. 2 Lime Kilns are fired with natural gas and/or fuel oil and have low-NO x burners. Concentrated non-condensable gases (LVHC) a nd the foul condensate stripper gases are incinerated in the lime kilns. Both the No.1 and No. 2 Lime Kilns are vented to a scrubber to control particulate emissions. The VIP’s which both the No. 1 and No. 2 Lime Kilns emit and will require a BART analysis are SO 2 , NO x , and PM 10 .

Case by Case Analysis The first step in the BART control technology analysis is to develop a comprehensive list of the potential contro l technologies and improvements to existing control equipment that could potentially reduce Visibility Impairing Pollutant s (VIP). Then review these to determine if they are technically feasible fo r the source. Once a c ontrol technology has been deemed technically feasible by both IP and the Department, an evaluation on the effectiveness and cost of compliance will be reviewed. These steps were followed for each unit and for each pollutant requiring a BART analysis. The case by case BART analysis of each unit can be found below, grouped by pollutant.NO x BART Analysis IP Courtland identified the following cont rol technologies for the control of NO x emissions at the Courtland Mill.

• Selective Catalytic Reduction (SCR)

• Selective Non-Catalytic Reduction (SNCR)

• Low NO x Burners

• Combustion Control Techniques

• Flue Gas Recirculation

IP has identified all but the SCR as techni cally feasible control technologies at the Courtland Mill. Table 1 below shows the results of IP’s control effectiveness review for all BART-eligible units for NO x.

Table 1. NO x Control Effectiveness Review Summary

Emissions Reduction Cost Visibility Improvement Unit Control Option % Reduction Tons
Removed ($/Ton) 98 th Percentile 24-
hr (dV)
SNCR 35 142.8 $6,097 0.020 No. 1 Combo
Low NO x Burners 30 122.3 $1,188 0.013SNCR 35 518.2 $2,081 0.097 No. 2 Combo
Low NO x Burners 30 444.2 $585 0.083

SCR 90 108 $12,375 0.037
SNCR 50 60 $16,024 0.017 Package Boiler
Low NO x w/
FGR 50 60 $2,767 0.017

Due to the inherit nature of a Recovery Furn ace, no other controls where deemed feasible besides Combustion Controls. 40 CFR Part 51, Appendix Y, does not require a cost effectiveness review and visibi lity study as long as federa lly enforceable limits are in place. Therefore a cost eff ectiveness review and visibi lity study was not conducted on the No. 2 Recovery for NO x, since Combustion Control Te chniques are common practice for this unit and are presently in-place, and th ere are no other technically feasible control technologies available.

Since both the No.1 and No.2 Lime Kilns currently employ Low-NO x Burners in the form of combustion flame tuning to reduce NO x emissions, and no other controls where deemed feasible a cost effectiveness revi ew and visibility st udy was not conducted as allowed by 40 CFR Part 51, Appendix Y.SO 2 BART Analysis IP Courtland identified the following cont rol technologies for the control of SO 2 emissions at the Courtland Mill.

• Lower Sulfur Fuels

• Dry Scrubbing

• Semi-dry Scrubbing

• Low pressure drop scrubber

• Low pressure drop Wet Scrubbing with a Wet ESP (WESP)

• High pressure drop scrubber

• Addition of Caustic to existing Scrubber

IP has identified all of the a bove listed control tec hnologies as technically feasible at the Courtland Mill. Table 2 below shows the results of IP’s control effectiveness review for all BART-eligible units for SO 2 .

Table 2. SO 2 Control Effectiveness Review Summary

Emissions Reduction Cost Visibility Improvement Unit Control Option % Reduction Tons
Removed ($/Ton) 98 th Percentile 24-
hr (dV)
No. 1 Combo Addition of Caustic to 93 180.7 $7,260 0.013existing Scrubber Dry Scrubbing 93 180.7 $14,574 0.013 Semi-dry Scrubbing 93 180.7 $11,420 0.013

High ∆ P Wet Scrubbing 93 1149 $3,633 0.063 No. 2 Recovery High ∆ P Wet Scrubbing /
WESP 93 1149 $4,336 0.063

Since the No. 2 Combo Boiler is currently controlled by a wet scrubber, which is considered the most stringent control technol ogy for this unit, a control effectiveness review study was not performed.

Although the package boiler is a BART eligible source for SO 2 , a control effectiveness review study was not performed since this source only emits approximately 1 tpy of SO 2 . Since this unit only fires natural gas the emissions from this unit are minimal and there would be virtually no impact on visibility, therefore no BART controls were reviewed.

Due to the inherit nature of a Smelt Dissolving Tank, the SO x emissions are variable and depend on the recovery furnace. IP estimated the SO 2 emissions from this unit to beapproximately 1 tpy; therefore a technical feas ibility study nor a cost effectiveness review and visibility study was performe d since there would b4 virtually no impact on visibility .

The No. 1 and No. 2 Lime Kilns ar e BART eligible sources for SO 2 ; however 40 CFR Part 51, Appendix Y exempts units from perf orming a technical feasibility study and a cost effectiveness review and visibility study if they are complying with MACT Standards. Since both these Lime Kilns ar e subject to and are complying with 40 CFR Part 63 Subpart MM through the use of wet scr ubbers, and since the inherit nature of lime kilns minimize SO 2 emissions IP considers the current approach to MACT II compliance should serve as BART for SO 2 for these Lime Kilns.

PM 10 BART Analysis IP Courtland identified the following cont rol technologies for the control of PM 10 emissions at the Courtland Mill.

• Wet Scrubber

• Multi Tube Dust Collector with ESP

• ESP

Since the No. 1 Combo Boiler is currently controlled by a wet scrubber, which is considered the most stringent control tec hnology for this unit and will comply with ADEM Admin. Code R. 335-3- 11-.06(107) [Boiler MACT], a control effectiveness review study was not performed.Since the No. 2 Combo Boiler is currently c ontrolled by a multi tube dust collector with ESP, which is considered the most stringent control technology for this unit and will comply with ADEM Admin. Code R. 335-3- 11-.06(107) [Boiler MACT], a control effectiveness review study was not performed.

The Package Boiler is a natural gas fired bo iler and the PM10 emissions are less than 10 tpy. Natural gas fired boiler typically to not require add on controls for PM10 and since this unit is also typically utilized only dur ing the winter months a control effectiveness review study was not performed.

The No.2 Recovery, No. 2 Smelt Tank, No. 1 a nd No. 2 Lime Kilns are BART eligible sources for PM10; however 40 CFR Part 51, Appendix Y exempts these units from performing a technical feasibility study and a cost effectiveness re view and visibility study since these units are subj ect to and complying with a particulate MACT Standard, (40 CFR Part 63, Subpart MM).

Cost of Compliance In reviewing the cost of c ontrols based on the amount of emissions removed, IP has indicated that additio nal controls for SO 2 would not be cost eff ective at the Courtland Mill. IP has also indicated that the Control of NO x is only cost effective for the No. 2 Combination Boiler and that no other add-on cont rols would be cost effective for all other sources. The current add-on controls which control particles at the Courtland mill have efficiencies of greater than 90% therefore no additional controls would be cost effectiveoptions.

Energy and Non-Air Quality Environmental Impacts IP has indicated that there would be a reduced energy efficiency and an increase in fuel usage as a result of the installation of Low NO x burners on the No. 1 Combo and No. 2 Combo boilers. The Department has reviewed these concerns and had determined that the small reduction in energy efficiency and increase in fuel usage for the No. 2 Combo boiler does not offset the visibility improveme nts or the cost effectiveness of $585/ton of
NO x removed. IP has also i ndicated that additional NO x controls for ot her units would cause significant impacts to the energy effici encies and potentially allow other pollutants to be emitted to the atmosphere.

IP has suggested that any additional control of SO 2 at any of the BART eligible sources at IP would cause an significant increase in ener gy usages and/or gene rate a waste stream that would have to be disposed of; ther eby incurring disposal costs and possible permitting issues with other medias.

Proposed BART
NO x

• Install low NO x Burners or only operate the No. 1 Combination Boiler when one of the following emissions units is either no t operating or in periods of start-up of shutdown: the No. 2 Combination Boiler the No. 2 Recovery Furnace, the No. 3 Combination Boiler, or the No. 3 Recovery Furnace.• Install low NO x Burners, which will give a 30 % baseline reduction in emissions, on the No. 2 Combination Boiler.

• IP has proposed using existing combusti on control techniques for the control of
NO x on the Package Boiler.

• The No. 2 Recovery Furnace will utili ze existing combustion control techniques for the control of NO x .

• IP proposed the existing Low NO x burners for the No. 1 a nd No. 2 Lime Kilns for control of NO x emissions for these units.

SO 2

• IP has proposed no add on controls for the No. 1 Combination Boiler, No. 2 Recovery Furnace, No. 2 Smelt Tank, No. 1 Lime Kiln, and No. 2 Lime Kiln for the control of SO 2 emissions.

• The existing Wet Scrubber will be utilized to control SO 2 emissions from the No. 2 Combination Boiler.

• Since the Package Boiler only fires natural gas, no add- on controls are warranted. The firing of only natural gas will be a federally enforceable limit

PM 10

• IP has proposed utilizing the existing Venturi Scrubbe r for the control of PM emissions from the No. 1 Combination Boiler.

• The No. 2 Combination Boiler will utili ze the existing multi tube dust collectors with electrostatic precipitator for the control of PM emissions.• IP had proposed no controls for the P ackage Boiler due to the low particulate emissions associated with the firing of natural gas.

• The existing electrostatic precipitator will be utilized to control PM emissions for the No. 2 Recovery Furnace.

• IP has proposed to utili ze the existing wet scrubber wh ich is required by 40, CFR Part 63, Subpart MM, as the BART cont rol device for the control of PM emissions from the No. 2 Smelt Tank

• The existing Venturi Scrubbers will be utilized to cont rol PM emissions from both Lime Kilns No. 1 and No. 2.

Table 3 below presents the summarized BART emission limits for the IP Courtland Mill.
Table 3. BART Emission Limits Emission Limitations Emission Unit NO x SO 2 PM 10 No. 1 Combo 93.15 lb/hr or operational limitations 147.3 lb/hr 0.17 gr/sdcf @ 50% Excess Air
No. 2 Combo 338.13 lb/hr 1.20 lb/MMbtu & 65.5 lb/hr 0.10 lb/MMbtu Package Boiler 0.20 MMbtu & <1,200 million ft 3 of natural gas / 12 month period 1.80 lb/MMbtu 0.10 lb/MMbtu

No. 2 Recovery 152 lb/hr 432 lb/hr 0.044 grains/SDCF at 8 % O 2 and 67 lb/hr No. 2 Smelt Tank NA 0.20 lb/hr 0.20 lb/ ton of black liquor solids No. 1 Lime Kiln 3.5 lb/hr 0.10 lb/hr 1.0 lb/air dried ton of pulp No. 2 Lime Kiln 19.40 lb/hr 0.23 lb/hr 0.067 gr/sdcf at 10% O 2
The Department concurs with the proposed BA RT limitations. These limitations will bewritten into air permits and will be e ffective by January 1, 2013. The limitations established under BART (Best Available Retr ofit Technology) may be changed through the NSR (New Source Review) permit process wh ich should include a visibility analysis prior to the modification.

Evaluate Visibility Impacts The modeled visibility improvement as a re sult of installing the proposed add on BART controls, federally enforceable limits, and operational limitations would range between 0.2 and 0.4 deciviews improvement in the Sips ey Wilderness Area. Although this is a small visibility improvement it has a large re duction in the number of days above 0.5 deciviews in the Sipsey Wilderness Area. Relative to the base case of 98 days above 0.5 deciviews, the three modeled scenarios indicate only 40, 59, and 56 days above 0.5 deciviews, which equates to an average improvement of 45 days.

Recommendation The proposed limitations appear to meet the requirements for BART. Therefore, I recommend that the attached Air Permit be issued.

_________________________ C. Scott SandersIndustrial Chemicals Section Chemical Branch Air Division

October 22, 2007

Date