Pre-Construction Review
and
Preliminary Determination
of Approval for
Hood Industries Inc.
Facility No. 1500-00020

Technical Review
by
LaTrina Williams

Air Quality Analysis
By
Jacqueline Evens

June 11, 2019
I.	General Information
Hood Industries Inc., 66 Miles Lumber Company Road, Silver Creek, Mississippi 39663, (601) 886-7844 , has submitted a complete air permit application for a Prevention of Significant Deterioration Construction Permit.  The proposed project consists of the removal of two direct-fired batch lumber kilns, and the construction of two new direct-fired batch lumber kilns and a fuel silo.
Hood Industries produces pine lumber and timbers, with wood shaving and wood chips produced as a secondary product.  The facility has a current Title V Operating Permit (1500-00020) for which a re-issuance Air application has been submitted to MDEQ.
The MDEQ received the PSD Construction Permit Application on March 15, 2019, which included a process description, emissions calculations, a Best Available Control Technology (BACT) Analysis, and a Source Impact Analysis. Supplemental information was received on March 28, 2019.  The project will result in emissions of VOCs that exceed the significant emissions rates for Ozone in Mississippi’s PSD regulations, 11 Miss. Admin Code Pt. 2, Ch. 5 which adopt by reference EPA’s PSD regulations found in 40 CFR 52.21.
II.	Project Description
Hood Industries is currently permitted to operate four (4) direct-fired batch lumber kilns.  The facility is proposing to removed two (2) 21 MMBtu/hr direct-fired kilns (Emission Point AA-001 and AA-002) and construct two (2) new 30 MMBtu/hr direct-fired kilns.  The new kilns would provide greater operational flexibility and capacity, if needed.  The kilns will be fired by wood residue each new kiln will have an annual potential capacity of 56,064 MBF/yr.
Table 1. PSD Applicability 
Pollutant	Project-Related Increases
(TPY)	Significant Emission Rate
(TPY)	Netting Analysis Required?
(Yes/No)	Contemporaneous Emissions 3
(TPY) 	Total Net Emissions
(TPY)	PSD Review Required?
(Yes/No)	
PM	12.47	25	No	1.34	13.81	No	
PM10	6.85	151	No	0.80	7.65	No	
PM2.5	5.31	10	No	0.67	5.98	No	
NOX1,2	8.90	40	No	1.23	10.13	No	
SO21	6.30	40	No	0.25	6.55	No	
VOC2	115.38	40	Yes	16.49	131.87	Yes	
CO	16.62	100	No	2.34	18.96	No	
1 As of April 28, 2011, both NOx and SO2 are precursors for PM2.5.  Therefore, if NOx or SO2 exceed 40 TPY, the project is considered major for PM2.5.
2 Both NOx and VOC are considered precursors for ozone with a significant emission rate of 40 TPY each.
3Applicant evaluated netting and VOC was still above the threshold.
III.	Best Available Control Technology (BACT) Analysis
The applicant is required to perform a BACT analysis for all pollutants that have a significant net emissions increase. Utilizing the “top-down” approach detailed in EPA’s New Source Review Workshop Manual (Draft 1990), the PSD applicant goes through a five step process to determine BACT: (1) Identify all control technologies; (2) Eliminate technically infeasible control options; (3) Rank the remaining control technologies by control effectiveness; (4) Evaluate the most effective controls taking into consideration economic, energy, and environmental impacts; and (5) Select BACT.  BACT is an emission limitation based on the maximum degree of pollutant reduction determined on a case-by-case basis, taking into account energy, environmental, and economic impacts, that is determined to be achievable for a source.  A BACT analysis must be performed for each new and modified emission unit that emits any of the pollutants exceeding the significant emissions rate.  This proposed permit modification results in an increase in VOC emissions above the significant emission rate for major modifications, and therefore is subject to a BACT review for VOC.  BACT for the proposed two direct-fired kilns (AA-001 and AA-002) is described below.  
A.	VOC Analysis
•	Step 1 – IDENTIFY ALL Control Technologies
Based on general process knowledge, technical literature, equipment vendor information, and the RACT/BACT/LAER Clearinghouse (RBLC) maintained by the U.S. EPA, six control options were identified. These options are:
• Incineration
• Adsorption
• Absorption
• Condensation
• Biological Treatment
• Proper Maintenance and Operation
	Incineration
This technology may be employed with several different approaches including direct incineration, regenerative thermal oxidation, or catalytic oxidation. These devices use the VOC laden air stream as a source in addition to natural gas. High VOC content streams can see significant destruction efficiencies, as high as 99% depending on the exact characteristics of the incoming air stream and the oxidation technology used.
Adsorption
Adsorption is another technology that could be used for the control of VOC air emissions. In the adsorption process, organics are collected on the surface of a porous solid such as activated carbon or synthetic resins. As a VOC laden air stream passes through the material, it is adsorbed into the activated carbon or synthetic resin. Over time, the adsorbents must be replaced or regenerated when they become saturated with VOC. These systems may produce control efficiencies in the 90% range.
Absorption
Absorption can be employed to capture VOC into a liquid substrate, most commonly water.  This can be accomplished in what is typically referred to as a wet scrubber, and these devices can typically be found controlling emissions from boiler stacks, usually for PM. 
Condensation
Condensation is a simple vapor-liquid equilibrium process whereby the VOC vapors are cooled and converted into a liquid.  This technology is difficult to employ on its own and may need a secondary control technology as well.
Biological Treatment
Typically known as biofiltration, this technology uses microorganisms to absorb and breakdown the incoming waste stream. This technology is more common in wastewater treatment.
Proper Maintenance and Operation
This technology employs best operating practices, proper maintenance, and proper drying techniques based on the type of lumber and wood moisture content to effectively reduce VOC emissions.  This method has been demonstrated successfully in many other PSD projects in the U.S. for dry kilns.

•	STEP 2 – Eliminate technically infeasible control options
Evaluation of the feasibility of the identified technologies narrows the scope of potential BACT applications considerably.
Beyond the technical aspects of the suitability of the different BACT applications, it must first be determined how to capture the fugitive VOC stream such that it may be routed to a control device. Due to the nature of the kilns, which are open on both ends, creating only dispersed fugitive emissions; there is no known successful attempt to capture these fugitive releases. Irrespective of this issue, an individual analysis of each technology’s suitability is below.
Incineration
Incineration as a VOC control technology is generally done with a regenerative thermal oxidizer, RTO, or in a regenerative catalytic oxidizer, RCO. To achieve a destruction and removal efficiency of greater than 90% in an RTO, a temperature of approximately 1,500ºF with a residence time of at least one second is required. With the kiln exit temperature being only 140ºF and containing significant moisture, routing this air to a 1500ºF RTO would create significant issues inside the device. Additionally, due to the resinous nature of the VOCs released from lumber drying, it would foul the ductwork and media in the device over time. Thus, due to the resinous characteristics, the high moisture content, and very low exit temperature of the kiln exhaust, an RTO is infeasible.
In an RCO, the required temperature is typically reduced to 500ºF - 800ºF. While an RCO may be more suitable for this application since it operates at a much lower temperature, it is still four times higher than a typical kiln exhaust temperature. As in an RTO, the resinous nature of the VOCs released from lumber drying could foul the ductwork and media in the device. The catalysts are very susceptible to fowling due to particulates or other air stream contaminants causing frequent catalyst change outs or an additional control device upstream of the RCO. Due to the resinous nature of the VOCs, the high moisture content and low exit temperature, an RCO is infeasible.
Adsorption
Using a media such as activated carbon to adsorb the VOC into the activated carbon substrate may be accomplished at a temperature suitable with the kiln exhaust; however, the high moisture content and resinous nature of the VOCs reduces the capacity and efficiency of the carbon.  This causes “blinding” of the carbon and in turn reduced efficiencies and frequent changeouts of the material.
Absorption
Technology such as a wet scrubber is compatible with the kiln exhaust temperature; however, this technology requires an exhaust stream that is soluble in water but the VOC in the kiln exhaust is relatively insoluble in water.  A different scrubbing absorbent could be considered, but these are typically classified as VOC, which conflicts with the control purpose.
Condensation
This technology cannot achieve a typical EPA-required removal efficiency of 90% for pinenes, the dominant VOC in the exhaust stream, using standard condensers. A technical analysis shows that a condensing temperature of -35ºF would be required, which makes this control technology infeasible, if not impossible due to the freezing of the water vapor in the system. In addition, the drying of 200 MMBF/yr of lumber removes approximately 135,000 gallons of water in vapor form from the wood per day. All of this water would be condensed in any type of condensing control device and would become process wastewater. The sawmill industry is not allowed a discharge of process wastewater into navigable water by the National Pollutant Discharge Elimination System (NPDES) regulations found at 40 CFR Part 429, Subpart K, Sawmills and Planing Mills Subcategory. The Best Available Control Technology Economically Achievable (BACT) and the New Source Performance Standards (NSPS) both read: “There shall be no discharge of process wastewater pollutants into navigable waters.” If a discharge was allowed, the cost of the treatment system to treat the 135,000 gallons of wastewater could be equal to or greater than the cost of the kilns themselves. That would make this alternative, if it was regulatory feasible, economically infeasible. Condensation technology is technically infeasible due to the inability to adequately control the VOC present using this   technology, the regulatory prohibition on the direct discharge of process wastewater, and the estimated prohibitive cost in designing and building a water treatment system, and the ongoing extensive monitoring and energy costs of maintaining the system.
Biological Treatment
These systems typically operate at 105ºF or less causing incompatibility with the higher temperature VOC stream, which would harm the microorganisms. Additionally, the resinous VOC stream would have a tendency to foul the biofilter. The cooling of the VOC stream would also create more process wastewater problems similar to the condensation approach.
•	STEP 3 – SELECTION OF BACT 
Hood has identified six potential control technologies for the control of VOC emissions from lumber kilns. Hood believes that five of those technologies are technically infeasible, and proposes that the remaining technology, “proper operation and maintenance”, be utilized as BACT for this project.
Hood will implement this BACT for VOC by following an operation and maintenance (O&M) plan. This BACT is consistent with MDEQ permitting actions for batch drying kilns of similar or greater capacity at other sites in Mississippi and is the only accepted BACT for kilns listed in the RBLC. 
In the interim, Hood will use the O&M Plan included in Appendix D of their application. At a minimum, the plan includes the following actions:  
•	Kiln operation control equipment will be calibrated and operated as per manufacturer’s specifications.
•	The lumber kiln drying operation target final moisture content will be set at 12% or greater.
•	Routines for preventative maintenance will be as detailed in a monitoring based on manufacturer’s recommendations.  The plan will, at a minimum, identify the frequency of maintenance for the following activities:
-	Conducting walk-around inspections;

-	Confirming proper wet-bulb operation;

-	Conducting entrance / exit baffle inspections;

-	Greasing the kiln cart wheels and fan shaft bearings; 

-	Checking hydraulic oil levels;

-	Calibrating moisture content equipment;

-	Calibrating temperature probe equipment.  

Hood will update and adjust the procedures listed in the initial O&M Plan as necessary once the kilns are operational and practical experience has been obtained. Additionally, Hood is closely monitoring the PCWP MACT, which will regulate dry kilns and will implement the practices that the MACT requires when this regulation is finalized.
Numerically, BACT is set to the following:

Pollutant
	BACT Determination	BACT Emission
Limit per Kiln	Equivalent Emissions per Kiln	
VOC	Proper Kiln Operation and Maintenance Practices	4.636 lb/MBF 
(29.7 lb/hr maximum)	130 TPY
(at max. capacity of 56,064 MBF/yr)	
IV.	Source Impact Analysis
The owner or operator of a proposed source or modification is required to demonstrate that allowable emission increases from the proposed source or modification, in conjunction with all other applicable emissions increases or reductions (including secondary emissions), will not cause or contribute to air pollution in violation of: 1) any national ambient air quality standard in any air quality control region; or 2) any applicable maximum allowable increase over the baseline concentration in any area.
The modeled concentrations used to determine compliance with any NAAQS and PSD increment depend on 1) the type of standard, i.e., deterministic or statistical, 2) the available length of record of meteorological data, and 3) the averaging time of the standard being analyzed.  When the analysis is based on 5 years of National Weather Service meteorological data, the following estimates are used:
•	For deterministically based standards (e.g., SO2), the highest, second-highest short term estimate and the highest annual estimate; and
•	For statistically based standards (e.g., PM10), the highest, sixth-highest estimate and highest 5-year average estimate.
A.	Existing Air Quality
Any application for a permit under the Prevention of Significant Deterioration program is required to contain an analysis of ambient air quality in the area that the major stationary source or major modification would affect for each of the following pollutants: a) for the source, each pollutant that it would have the potential to emit in a significant amount; b) for the modification, each pollutant for which it would result in a significant net emissions increase.
The existing air quality is defined by the natural and human-generated sources of air pollution. The area surrounding the Lawrence County facility is considered rural and in attainment for all regulated pollutants.  The pollutant under consideration in the analysis is volatile organic compounds (VOC).
B.	Modeling Procedure
All estimates of ambient concentrations are to be based upon applicable air quality models, databases and other requirements specified in appendix W of 40 CFR Part 51 (Guideline on Air Quality Models).
The EPA Memorandum, “Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier I Demonstration Tool for Ozone and PM2.5 under the PSD Permitting Program,” dated December 2, 2016, reflects EPA’s recommendation for how agencies conduct air quality modeling and related technical analyses to satisfy compliance demonstration requirements for ozone and PM2.5 under the PSD Permitting Program. In accordance with the MERPs Guidance and the Revisions to the Guideline on Air Quality Models (40 CFR Part 51, Appendix) EPA recommends that an applicant use a “two-tiered” demonstration approach to address single-source impacts on ozone and secondary PM2.5. The first tier involves the use of existing technical information to evaluate the relationships between precursor emissions and a source’s impacts. The second tier involves the application of more sophisticated case-specific chemical transport models (CTMs) (e.g., photochemical grid models).
Should the Tier I Demonstration find the critical air quality threshold would not be exceeded when considering the combines impacts of the Ozone precursor emissions of NOx and VOC on the 8-hr daily maximum ozone; the proposed project will not cause ozone concentrations exceeding the ozone SIL. No further analysis needed. No additional modeling required.
C.	Air Quality Monitoring Requirements
The ambient air quality analysis is required to contain continuous air quality monitoring data gathered for purposes of determining whether emissions of that pollutant would cause or contribute to a violation of the standard or any maximum allowable increase.  The source may be exempt from the preconstruction monitoring requirements if the air quality impacts are less than the monitoring de minimis concentrations. The monitoring de minimis levels are listed in Table 1. 
Table 1 - Preconstruction de minimus levels.
Pollutant	Averaging Period	Monitoring de minimis Concentration (μg/m3)	Modeled Concentration (μg/m3)	
PM10	24-hour	10	-	
PM2.5	24-hour	4	-	
SO2	24-hour	13	-	
NO2	Annual	14	-	
Ozone		VOC or NOx  emission increase < 100 TPY	131.87-tpy  VOC 10.13-tpy NOx	
CO	8-hour	575	-	
Lead	3-month avg	0.1	-	
Fluorides	24-hour	0.25	-	
Total Reduced Sulfur	1-hour	10	-	
Hydrogen Sulfide	1-hour	0.2	-	
Reduced Sulfur Compounds	1-hour	10	-	

If either the predicted modeled impact from an emission increase or the existing ambient concentration is less than the monitoring de minimis concentration, MDEQ has the discretionary authority to exempt an applicant from pre-construction ambient monitoring. No de minimis air quality level is provided for Ozone. However, any net emissions increase of 100-tpy or more of volatile organic compounds or nitrogen oxides subject to PSD would be required to perform an ambient impact analysis, including the gathering of ambient air quality data. Pre-construction monitoring of ozone can be waived if representative data for the area is available. MDEQ monitors this pollutant at several monitors across the state. Existing ambient air monitoring for this pollutant will be used in lieu of conducting preconstruction monitoring. 
Ozone – Hinds County (N-CORE) (Monitor ID: 28-049-0020) & Hinds County (CC) (Monitor ID: 28-049-0021)
Monitor ID 28-049-0020 (Site Address, 232 E Woodrow Wilson Avenue, Jackson, MS) and Monitor ID 28-049-0021 (Site Address, 3925 Sunset Drive, Jackson, MS) monitors ozone and are located approximately 70 miles north of the Hood Industries, Inc., Silver Creek Plant. Data has indicated that the monitored area is in attainment with the 8-hour CO standard. The 8-hour average is met if the 8-hour average of 9-ppm is not exceeded more than once per year. 
	Table 2. Hinds County 8-hour Ozone (ppb)
Year	Hinds County (CC) 
4th Daily Max (ppb)	Hinds County (N-CORE) 
4th Daily Max (ppb)	
2016	63	60	
2017	59	59	
2018	68	63	
3-yr Period	63	60	

The land use surrounding the Hinds County (N-CORE) and the Hinds County (CC) monitors is predominately urban, therefore, monitored values will likely provide a more conservative ambient concentration due to the industrialized location of the monitors. Because the Hinds County monitor would likely provide more conservative ambient concentrations due to the more commercial location of the monitor, the Hinds County monitors were selected as a conservative representative of the area surrounding the Silver Creek Plant.
Ozone Ambient Impact Analysis
No de minimis air quality level is provided for Ozone. However, any net emissions increase of 100-tpy or more of volatile organic compounds or nitrogen oxides subject to PSD would be required to perform an ambient impact analysis, including the gathering of ambient air quality data.
Ozone is a gas composed of three atoms of oxygen. Ozone occurs both in the Earth’s upper atmosphere and at ground level. Ground level Ozone occurs naturally in lower amounts and additional ozone is formed when nitrogen oxides (NOx) and VOC react chemically in the presence of sunlight. Emissions from cars, industrial facilities, electric utilities, refineries, and chemical plants are some of the major sources of NOx and VOC emissions. Because, this reaction takes time to occur, ozone is usually formed downwind of emission sources.
MDEQ collect and evaluate ozone data from various monitoring sites located in Mississippi. This data is compared to the current 8-hour National Ambient Air Quality Standard (NAAQS) for Ozone to determine how the state is doing in meeting this standard. In July 2012, part of DeSoto County was designated as part of the Memphis, Tennessee- Mississippi-Arkansas (Memphis, TN-MS-AR) Nonattainment Area by EPA. As presented in the “Mississippi Department of Environmental Quality 2015 Air Quality Data Summary” report, monitoring data collected from Monitor ID 28-033-0002 located in DeSoto County indicates Desoto County continues to meet the ozone standard. Mississippi was meeting the 8-hour Ozone NAAQS. On December 11, 2015, the State, through the MDEQ, submitted a request for EPA to redesignate the portion of Mississippi that is within the Memphis, TN-MS-AR from nonattainment to attainment for the 2008 8-hr ozone NAAQS. EPA approved Mississippi’s redesignation request effective May 9, 2016. As presented in the “Mississippi Department of Environmental Quality 2018 Air Quality Data Summary” report, Mississippi remains in attainment for all NAAQS.
Ozone Standard
There is one primary and secondary ozone standard – the 8-hour average. MDEQ monitors ozone continuously from March 1 through October 31 each year at the monitoring sites listed below. Ozone is monitored year around at the N-CORE site located in the Jackson MSA.
Primary and Secondary 8-Hour Ozone Standard
The 8-hour standard is met when the 3-year average of the annual fourth highest daily maximum 8-hour average concentration (also known as the design value) is less than or equal to 0.070 parts per million (ppm) or 70 parts per billion (ppb).
8-Hour Ozone Design Values
Standard – 70 ppb

			* Incomplete Data

Ozone Air Quality, 2000 – 2017
(Annual 4th Maximum of Daily Max 8-Hour Average South Trend based on 104 Sites)

Table 3. South Regional Trends in Ozone Levels

Air Quality trends can vary regionally. The contiguous United States comprise nine (9) climatically consistent regions. Mississippi is contained in the South Region. From 2000 to 2017, South Regional Trends have shown a 24% decrease in the Regional Average.

Table 4. 2014 National Emissions (NEI) Data Summary for Lawrence County, Mississippi
Major Source Type	Pollutants (total tons)	
	Nitrogen Oxides	Volatile Organic Compounds	
Biogenic Sources	91.25	17,276.80	
Fire Sources	49.26	500.20	
Mobile Sources	324.88	222.27	
Stationary Sources	1,991.09	3,603.01	
Total Emissions	2,456.48	21,602.28	

Table 4 depict air emissions data taken from the 2014 National Emissions Inventory Report. VOC emissions from Hood Industries, Inc – Silver Creek facility comprise approximately 0.61% of the total 2014 reported value for Lawrence County. The VOC emissions associated with the proposed project will not significantly affect/influence ambient ozone levels in Lawrence County and the surrounding areas. The project area will remain in compliance with the ozone NAAQS. 
D.	PSD Preliminary Analysis Modeling Impacts
In the preliminary analysis, only the significant increase in potential emissions of a pollutant from a proposed new source, or the significant net emission increase of a pollutant from a proposed modification is modeled.  A full impact analysis for a particular pollutant is not required when emissions of that pollutant from a proposed source or modification would not increase ambient concentrations by more than prescribed significant ambient impact levels. 
Tier 1 Demonstration for Ozone
In accordance with the Revisions to the Guideline on Air Quality Models (40 CFR Part 51, Appendix W) EPA recommends that an applicant use a “two-tiered” demonstration approach to address single-source impacts on ozone and secondary PM2.5. The first tier involves the use of existing technical information to evaluate the relationships between precursor emissions and a source’s impacts. The second tier involves the application of more sophisticated case-specific chemical transport models (CTMs) (e.g., photochemical grid models). The December 2016 Memorandum, “Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier 1 Demonstration Tool for Ozone and PM2.5 under the PSD Permitting Program”, reflected EPA’s recommendations on how to conduct an air quality modeling and related technical analyses to satisfy compliance demonstration requirements for Ozone and Secondary PM2.5 for permit related assessment under the PSD Program. Hood Industries, Inc. – Silver Creek facility, utilized the MERPs guidance to assess the proposed project impacts on ozone.
Calculation of MERPs for Ozone
8-Hour Ozone
The MERPs guidance provides modeling results representing the maximum downwind ozone concentrations due to NOX and VOC emissions of hypothetical sources. EPA conducted photochemical modeling of hypothetical sources using emission rates of 500-tpy, 1,000-tpy, and 3,000-tpy of both NOX and VOC for various locations throughout the US. The MERPs Guidance considers Mississippi to be located in the central US (CUS). Figure A-2 of the MERPs guidance presents the locations of the sources modeled in the central US. To derive a MERP value, the model predicted relationship between precursor emissions from hypothetical sources and their downwind maximum impacts can be combined with a critical air quality threshold using the following equation: 

MERP = Critical Air Quality Threshold *	Modeled Emission Rate from Hypothetical Source	
	Modeled Air Quality Impact from Hypothetical Source	
For Ozone, the modeled air quality impact of an increase in precursor emissions from the hypothetical source is expressed in units of ppb or ppm. Consistent with the modeled emissions rates that are input to the air quality model to predict a change in pollutant concentration, MERPs are expressed as an annual emissions rate in tons per year (tpy). 
The recommended ozone SIL of 1-ppb was chosen to represent the critical air quality threshold. The SIL represents a de-minimis impact level, that is, if the maximum concentration of ozone due to a single source is less than the SIL, then it can be concluded that the source has an insignificant contribution to ozone formation. Appendix A - Relationship Between Hypothetical Sources and Maximum Downwind Impacts was used to derive the most conservative MERPs for Ozone for comparison in this analysis. Table 4 presents the highest daily maximum 8-hr Ozone impacts from NOx and VOC from hypothetical source model simulations for hypothetical source 9. 
The most conservative hypothetical source’s modeled central US region emission rate and impacts along with the ozone SIL were used to calculate the MERPs values below: 

Table 5. Tier I Demonstration for Ozone
	Highest Daily Maximum 8-hr Ozone Impacts (ppb)	MERPs (tpy)	
Geographic Region	Hypothetical Source	Emission Rate (tpy)	NOx	VOC	NOx	VOC	
Central US (CUS)	9	500	2.60	0.02	192	25,000.00	
		1000	4.43	0.07	225.73	14,285.71	
		3000	10.42	0.56	287.91	4,918.03	

NOX MERP = 192-tpy 
VOC MERP = 4,918-tpy
To assess the additive secondary impacts on the 8-hr daily maximum ozone, the following equation was used: 
Project Impact as % of SIL =	NOx Emission Rate (tpy) from Project	+	VOC Emission Rate (tpy) from Project	* 100	
	NOx MERP (tpy) from Hypothetical Source		VOC MERP (tpy) from Hypothetical Source		

Project Impact as % of SIL = (10.31 tpy/192 tpy) + (131.87 tpy/4,918 tpy) = 0.08051 * 100 = 8.051%. 
A value less than 100% indicates that the critical air quality threshold will not be exceeded when considering the combined impacts of these precursors on 8-hour daily maximum ozone. The proposed project will not cause ozone concentrations exceeding the recommended significant impact level for ozone. No further analysis is required.
E.	PSD Full Impact Analysis Modeling Impacts
A full impact analysis is required for any pollutant for which the proposed source’s estimated ambient pollutant concentrations exceed prescribed significant ambient impact levels.  This analysis expands the preliminary analysis in that it considers emissions from: the proposed source; existing sources; residential, commercial, and industrial growth that accompanies the new activity ant the new source or modification.  For SO2, PM10, and NO2, the full impact analysis actually consists of separate analyses for the NAAQS and PSD increments.
The preliminary analysis results presented in Section D above, demonstrates the combined impacts of the ozone precursors, VOC and NOx, will not have a significant impact on the 8-hr daily maximum ozone. The proposed project will not cause ozone concentration exceeding the recommended significant impact level for ozone. No further analysis is required.
F.	Vegetation and Soils Impact
The owner or operator is required to provide an analysis of the impairment to visibility, soils and vegetation that would occur as a result of the source or modification.  The owner or operator need not provide an analysis of the impact on vegetation having no significant commercial or recreational value.
There will be no significant vegetation and soil-related air pollution impacts associated with the proposed project; therefore, no adverse impact on vegetation and soil is anticipated.
G.	Associated Growth Impact
The owner or operator is required to provide an analysis of the air quality impact projected for the area as a result of general commercial, residential, industrial and other growth associated with the source or modification. 
The proposed project is not expected to have a measurable effect on the residential, industrial and other growth associated with the source or modification. There will be no significant growth-related air pollution impacts associated with the proposed project; therefore, no adverse impact due to associated growth is anticipated.
H.	Class II Visibility
The Class II Visibility Analysis evaluates the impact the proposed project will have on local visibility conditions. This analysis is based upon impacts within the significant impact area of the proposed project and is separate from the Class I visibility analysis. Components contributing to visibility impairment include sulfates, NOx, PM, organic carbon, soot (elemental carbon), and crustal material.
No protected vistas or other sensitive areas were identified near the Hood Industries, Inc. – Silver Creek facility. No significant visibility impairment is expected. No further analysis needed.
I.	Class I Impact and Visibility
The proposed facility is located approximately 382.12-km from the Sipsey Wilderness Area and 203.32-km from the Breton Wilderness Area.  Due the distance and the proposed emission rates, no adverse impacts at the Class 1 areas are anticipated.
V.	Recommendation

The impact of the emission of air contaminants from the project has been evaluated and the staff believes that, with proper constraints and limitations, this project will operate within all State and Federal air pollution control laws and standards and will protect public health and welfare.  Therefore, the staff of the Board has preliminarily decided, based on available information, to recommend to the Board that a permit be issued for the construction of this proposed project.  However, before proceeding further with the staff evaluation, public comments are being solicited. The staff recommendation to the Board, as well as the Board decision, will be made only after a thorough consideration of all public comments.